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Huang W, Zhong X, Zampronio CG, Bottrill AR, Jones KGE, Tinoco AB, Guo L, Egertová M, Mirabeau O, Elphick MR. Discovery and functional characterization of a bombesin-type neuropeptide signaling system in an invertebrate. Proc Natl Acad Sci U S A 2025; 122:e2420966122. [PMID: 40153458 PMCID: PMC12002301 DOI: 10.1073/pnas.2420966122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2024] [Accepted: 02/19/2025] [Indexed: 03/30/2025] Open
Abstract
Neuropeptide signaling systems are key regulators of physiological and behavioral processes in animals. However, the evolutionary history of some neuropeptides originally discovered in vertebrates is unknown. The peptide bombesin (BN) was first isolated from the skin of the toad Bombina bombina and subsequently BN-related neuropeptides have been identified in other chordates, including gastrin-releasing peptide (GRP) and neuromedin B (NMB) in mammals, and a GRP-like peptide in the cephalochordate Branchiostoma japonicum. However, BN-type neuropeptides have hitherto not been identified in any nonchordate animals. Here, we report the discovery and functional characterization of a BN-type neuropeptide signaling system in an echinoderm-the starfish Asterias rubens. BN-type precursor proteins were identified in several echinoderm species based on their amino acid sequences and gene structures, and the mature structure of the A. rubens BN-type neuropeptide ArBN was determined using mass spectrometry. A protein related to vertebrate GRP/NMB-type G protein-coupled receptors was identified experimentally as the receptor for ArBN in A. rubens. Analysis of the distribution of the ArBN precursor in A. rubens using mRNA in situ hybridization and immunohistochemistry revealed a widespread pattern of expression in the central nervous system, digestive system, and locomotory organs. Moreover, effects of ArBN in A. rubens included contraction and retraction of the evertible stomach and inhibition of feeding behavior. Our findings show that the evolutionary history of BN-type neuropeptide signaling can be traced back to the deuterostome common ancestor of echinoderms and chordates. Furthermore, an ancient role of BN-type neuropeptides as regulators of feeding behavior has been revealed.
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Affiliation(s)
- Weiling Huang
- Centre for Evolutionary and Functional Genomics, School of Biological and Behavioural Sciences, Queen Mary University of London, LondonE1 4NS, United Kingdom
| | - Xingxing Zhong
- Centre for Evolutionary and Functional Genomics, School of Biological and Behavioural Sciences, Queen Mary University of London, LondonE1 4NS, United Kingdom
| | - Cleidiane G. Zampronio
- Proteomics Facility Research Technology Platform, School of Life Sciences, University of Warwick, CoventryCV4 7AL, United Kingdom
| | - Andrew R. Bottrill
- Proteomics Facility Research Technology Platform, School of Life Sciences, University of Warwick, CoventryCV4 7AL, United Kingdom
| | - Kite G. E. Jones
- Centre for Evolutionary and Functional Genomics, School of Biological and Behavioural Sciences, Queen Mary University of London, LondonE1 4NS, United Kingdom
| | - Ana B. Tinoco
- Centre for Evolutionary and Functional Genomics, School of Biological and Behavioural Sciences, Queen Mary University of London, LondonE1 4NS, United Kingdom
| | - Lijin Guo
- College of Animal Science, South China Agricultural University, Guangzhou510642, China
| | - Michaela Egertová
- Centre for Evolutionary and Functional Genomics, School of Biological and Behavioural Sciences, Queen Mary University of London, LondonE1 4NS, United Kingdom
| | - Olivier Mirabeau
- Brain-Immune Communication Lab, Institut Pasteur, Université Paris Cité, Bioinformatics and Biostatistics Hub, Inserm U1224, Paris75015, France
| | - Maurice R. Elphick
- Centre for Evolutionary and Functional Genomics, School of Biological and Behavioural Sciences, Queen Mary University of London, LondonE1 4NS, United Kingdom
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Moody TW, Ramos-Alvarez I, Jensen RT. Bombesin, endothelin, neurotensin and pituitary adenylate cyclase activating polypeptide cause tyrosine phosphorylation of receptor tyrosine kinases. Peptides 2021; 137:170480. [PMID: 33385499 DOI: 10.1016/j.peptides.2020.170480] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Revised: 12/17/2020] [Accepted: 12/17/2020] [Indexed: 12/12/2022]
Abstract
Numerous peptides including bombesin (BB), endothelin (ET), neurotensin (NTS) and pituitary adenylate cyclase-activating polypeptide (PACAP) are growth factors for lung cancer cells. The peptides bind to G protein-coupled receptors (GPCRs) resulting in elevated cAMP and/or phosphatidylinositol (PI) turnover. In contrast, growth factors such as epidermal growth factor (EGF) or neuregulin (NRG)-1 bind to receptor tyrosine kinases (RTKs) such as the EGFR or HER3, increasing tyrosine kinase activity, resulting in the phosphorylation of protein substrates such as PI3K or phospholipase (PL)C. Peptide GPCRs can transactivate numerous RTKs, especially members of the EGFR/HER family resulting in increased phosphorylation of ERK, leading to cellular proliferation or increased phosphorylation of AKT, leading to cellular survival. GRCR antagonists and tyrosine kinase inhibitors are useful agents to prevent RTK transactivation and inhibit proliferation of cancer cells.
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Affiliation(s)
- Terry W Moody
- Department of Health and Human Services, National Institutes of Health, National Cancer Institute, Center for Cancer Training, Bethesda, MD, 20892, USA.
| | - Irene Ramos-Alvarez
- National Institute of Diabetes, Digestive and Kidney Disease, Digestive Diseases Branch, 9000 Rockville Pike, Bethesda, MD, 20892 USA
| | - Robert T Jensen
- National Institute of Diabetes, Digestive and Kidney Disease, Digestive Diseases Branch, 9000 Rockville Pike, Bethesda, MD, 20892 USA
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Moody TW, Ramos-Alvarez I, Jensen RT. Neuropeptide G Protein-Coupled Receptors as Oncotargets. Front Endocrinol (Lausanne) 2018; 9:345. [PMID: 30008698 PMCID: PMC6033971 DOI: 10.3389/fendo.2018.00345] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Accepted: 06/11/2018] [Indexed: 12/15/2022] Open
Abstract
Neuropeptide G protein-coupled receptors (GPCRs) are overexpressed on numerous cancer cells. In a number of tumors, such as small cell lung cancer (SCLC), bombesin (BB) like peptides and neurotensin (NTS) function as autocrine growth factors whereby they are secreted from tumor cells, bind to cell surface receptors and stimulate growth. BB-drug conjugates and BB receptor antagonists inhibit the growth of a number of cancers. Vasoactive intestinal peptide (VIP) increases the secretion rate of BB-like peptide and NTS from SCLC leading to increased proliferation. In contrast, somatostatin (SST) inhibits the secretion of autocrine growth factors from neuroendocrine tumors (NETs) and decreases proliferation. SST analogs such as radiolabeled octreotide can be used to localize tumors, is therapeutic for certain cancer patients and has been approved for four different indications in the diagnosis/treatment of NETs. The review will focus on how BB, NTS, VIP, and SST receptors can facilitate the early detection and treatment of cancer.
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Affiliation(s)
- Terry W. Moody
- Department of Health and Human Services, National Cancer Institute, Center for Cancer Research, National Institute of Diabetes, Digestive, and Kidney Disease (NIDDK), Bethesda, MD, United States
| | - Irene Ramos-Alvarez
- Digestive Diseases Branch, National Institute of Diabetes, Digestive, and Kidney Disease (NIDDK), Bethesda, MD, United States
| | - Robert T. Jensen
- Digestive Diseases Branch, National Institute of Diabetes, Digestive, and Kidney Disease (NIDDK), Bethesda, MD, United States
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Ma Z, Zhang Y, Su J, Li X, Yang S, Qiao W, Suo C, Lei Z. Distribution of the pig gastrin-releasing peptide receptor and the effect of GRP on porcine Leydig cells. Peptides 2018; 99:142-152. [PMID: 28966141 DOI: 10.1016/j.peptides.2017.09.015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/20/2017] [Revised: 09/23/2017] [Accepted: 09/25/2017] [Indexed: 01/22/2023]
Abstract
Gastrin-releasing peptide (GRP) is a mammalian bombesin (BN)-like peptide which plays a role in a number of important physiological functions via its receptor (gastrin-releasing peptide receptor, GRPR) in most animals. However, little is known about the gene encoding GRPR and its functions (especially reproduction) in pigs. In this study, we first cloned and analyzed the pig GRPR cDNA. Then we systematically investigated the expression levels of GRPR mRNA by relative real-time PCR (RT-PCR), and analyzed the distribution of the GRPR protein in pig tissues via immunohistochemistry (IHC). Finally, we studied the effect of GRP on testosterone secretion and GRPR (mRNA and protein) expression in Leydig cells. Results showed that the pig GRPR cDNA cloned at 1487bp, including one open reading frame (ORF) of 1155bp and encodes 384 amino acids. Significantly, compared with other species, the cDNA sequence and amino acid sequence of the pig GRPR were highly homologous and conservative. The RT-PCR results showed that: in the central nervous system (CNS) and the pituitary, GRPR mRNA was found in the cerebellum, hypophysis, spinal cord and hypothalamus; in the peripheral tissues, GRPR mRNA was mainly expressed in the pancreas, esophagus, ovary, testis, spleen, thymus, jejunum lymph node, muscle and fat. Moreover, the IHC results showed that GRPR immunoreactivity was widely distributed in the pig tissues and organs, such as the pancreas, esophagus, testis, ovary, spleen, pituitary gland and adrenal gland. In addition, we found that GRP promotes testosterone secretion, and increases GRPR mRNA and protein expression in cultured Leydig cells in vitro. These molecular and morphological data not only describe the anatomical locations of GRPR in pigs, but also provide the theoretical foundation for further research into its possible physiological functions in pigs. These results suggest that the GRP/GRPR system may play an important role in regulating the reproductive system of the boar.
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Affiliation(s)
- Zhiyu Ma
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, PR China
| | - Ying Zhang
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, PR China
| | - Juan Su
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, PR China
| | - Xiang Li
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, PR China
| | - Sheng Yang
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, PR China
| | - Wenna Qiao
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, PR China
| | - Chuan Suo
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, PR China
| | - Zhihai Lei
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, PR China.
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Mo C, Huang L, Cui L, Lv C, Lin D, Song L, Zhu G, Li J, Wang Y. Characterization of NMB, GRP and their receptors (BRS3, NMBR and GRPR) in chickens. J Mol Endocrinol 2017; 59:61-79. [PMID: 28500250 DOI: 10.1530/jme-17-0020] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/15/2017] [Accepted: 05/03/2017] [Indexed: 12/30/2022]
Abstract
The two structurally and functionally related peptides, gastrin-releasing peptide (GRP) and neuromedin B (NMB) play critical roles in many physiological/pathological processes in mammals. However, the information regarding the expression and functionality of avian NMB, GRP and their receptors is limited. Here, we characterized cNMB, cGRP and their receptors (cNMBR, cGRPR and cBRS3) in chickens. Our results showed that: (1) cNMBR and cGRPR expressed in CHO cells could be potently activated by cNMB and cGRP, respectively, as monitored by cell-based luciferase reporter assays, indicating that cNMBR and cGRPR are cNMB- and cGRP-specific receptors; strikingly, BRS3 of chickens (/spotted gars), which is orthologous to mouse bombesin receptor subtype-3 (BRS3), could be potently activated by GRP and NMB, demonstrating that both peptides are the endogenous ligands for chicken (/spotted gar) BRS3; (2) quantitative real-time PCR (qPCR) revealed that cGRPR is widely expressed in chicken tissues with abundant expression in the ovary, pancreas, proventriculus, spinal cord and brain, whereas cNMB, cNMBR and cBRS3 are mainly expressed in the brain and testes; (3) interestingly, qPCR, Western blot and immunostaining revealed that cGRP is predominantly expressed in the anterior pituitary and mainly localized to LH-cells, suggesting that cGRP is likely a novel pituitary hormone in chickens. In summary, our data help to uncover the roles of GRP, NMB and their receptors in birds, and provide the first persuasive evidence from an evolutionary prospective that in vertebrates, GRP and NMB are the endogenous ligands for BRS3, an orphan receptor that has puzzled endocrinologists for more than two decades.
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Affiliation(s)
- Chunheng Mo
- Key Laboratory of Bio-resources and Eco-environment of Ministry of EducationCollege of Life Sciences, Sichuan University, Chengdu, People's Republic of China
| | - Long Huang
- Key Laboratory of Bio-resources and Eco-environment of Ministry of EducationCollege of Life Sciences, Sichuan University, Chengdu, People's Republic of China
| | - Lin Cui
- Key Laboratory of Bio-resources and Eco-environment of Ministry of EducationCollege of Life Sciences, Sichuan University, Chengdu, People's Republic of China
| | - Can Lv
- Key Laboratory of Bio-resources and Eco-environment of Ministry of EducationCollege of Life Sciences, Sichuan University, Chengdu, People's Republic of China
| | - Dongliang Lin
- Key Laboratory of Bio-resources and Eco-environment of Ministry of EducationCollege of Life Sciences, Sichuan University, Chengdu, People's Republic of China
| | - Liang Song
- Key Laboratory of Bio-resources and Eco-environment of Ministry of EducationCollege of Life Sciences, Sichuan University, Chengdu, People's Republic of China
| | - Guoqiang Zhu
- Key Laboratory of Bio-resources and Eco-environment of Ministry of EducationCollege of Life Sciences, Sichuan University, Chengdu, People's Republic of China
| | - Juan Li
- Key Laboratory of Bio-resources and Eco-environment of Ministry of EducationCollege of Life Sciences, Sichuan University, Chengdu, People's Republic of China
| | - Yajun Wang
- Key Laboratory of Bio-resources and Eco-environment of Ministry of EducationCollege of Life Sciences, Sichuan University, Chengdu, People's Republic of China
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Herling AW. Pharmacological Effects on Gastric Function. DRUG DISCOVERY AND EVALUATION: PHARMACOLOGICAL ASSAYS 2016:2341-2413. [DOI: 10.1007/978-3-319-05392-9_56] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2025]
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Moody TW, Moreno P, Jensen RT. Neuropeptides as lung cancer growth factors. Peptides 2015; 72:106-111. [PMID: 25836991 DOI: 10.1016/j.peptides.2015.03.018] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/12/2015] [Revised: 03/20/2015] [Accepted: 03/20/2015] [Indexed: 12/28/2022]
Abstract
This manuscript is written in honor of the Festschrift for Abba Kastin. I met Abba at a Society for Neuroscience meeting and learned that he was Editor-in-Chief of the Journal Peptides. I submitted manuscripts to the journal on "Neuropeptides as Growth Factors in Cancer" and subsequently was named to the Editorial Advisory Board. Over the past 30 years I have published dozens of manuscripts in Peptides and reviewed hundreds of submitted manuscripts. It was always rewarding to interact with Abba, a consummate professional. When I attended meetings in New Orleans I would sometimes go out to dinner with him at the restaurant "Commanders Palace". When I chaired the Summer Neuropeptide Conference we were honored to have him receive the Fleur Strand Award one year in Israel. I think that his biggest editorial contribution has been the "Handbook of Biologically Active Peptides." I served as a Section Editor on "Cancer/Anticancer Peptides" and again found that it was a pleasure working with him. This review focuses on the mechanisms by which bombesin-like peptides, neurotensin and vasoactive intestinal peptide regulate the growth of lung cancer.
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Affiliation(s)
- Terry W Moody
- Department of Health and Human Services, National Cancer Institute, Center for Cancer Research, Office of the Director, Bethesda, MD 20892, USA.
| | - Paola Moreno
- National Institute of Diabetes, Digestive, and Kidney Disease, Digestive Diseases Branch, Bethesda, MD 20892, USA
| | - Robert T Jensen
- National Institute of Diabetes, Digestive, and Kidney Disease, Digestive Diseases Branch, Bethesda, MD 20892, USA
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Ramos-Álvarez I, Moreno P, Mantey SA, Nakamura T, Nuche-Berenguer B, Moody TW, Coy DH, Jensen RT. Insights into bombesin receptors and ligands: Highlighting recent advances. Peptides 2015; 72:128-144. [PMID: 25976083 PMCID: PMC4641779 DOI: 10.1016/j.peptides.2015.04.026] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/02/2015] [Revised: 04/29/2015] [Accepted: 04/30/2015] [Indexed: 12/22/2022]
Abstract
This following article is written for Prof. Abba Kastin's Festschrift, to add to the tribute to his important role in the advancement of the role of peptides in physiological, as well as pathophysiological processes. There have been many advances during the 35 years of his prominent role in the Peptide field, not only as editor of the journal Peptides, but also as a scientific investigator and editor of two volumes of the Handbook of Biological Active Peptides [146,147]. Similar to the advances with many different peptides, during this 35 year period, there have been much progress made in the understanding of the pharmacology, cell biology and the role of (bombesin) Bn receptors and their ligands in various disease states, since the original isolation of bombesin from skin of the European frog Bombina bombina in 1970 [76]. This paper will briefly review some of these advances over the time period of Prof. Kastin 35 years in the peptide field concentrating on the advances since 2007 when many of the results from earlier studies were summarized [128,129]. It is appropriate to do this because there have been 280 articles published in Peptides during this time on bombesin-related peptides and it accounts for almost 5% of all publications. Furthermore, 22 Bn publications we have been involved in have been published in either Peptides [14,39,55,58,81,92,93,119,152,216,225,226,231,280,302,309,355,361,362] or in Prof. Kastin's Handbook of Biological Active Peptides [137,138,331].
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Affiliation(s)
- Irene Ramos-Álvarez
- Digestive Diseases Branch, NIDDK, National Institutes of Health, Bethesda, MD 20892-1804, United States
| | - Paola Moreno
- Digestive Diseases Branch, NIDDK, National Institutes of Health, Bethesda, MD 20892-1804, United States
| | - Samuel A Mantey
- Digestive Diseases Branch, NIDDK, National Institutes of Health, Bethesda, MD 20892-1804, United States
| | - Taichi Nakamura
- Digestive Diseases Branch, NIDDK, National Institutes of Health, Bethesda, MD 20892-1804, United States
| | - Bernardo Nuche-Berenguer
- Digestive Diseases Branch, NIDDK, National Institutes of Health, Bethesda, MD 20892-1804, United States
| | - Terry W Moody
- Center for Cancer Research, Office of the Director, NCI, National Institutes of Health, Bethesda, MD 20892-1804, United States
| | - David H Coy
- Peptide Research Laboratory, Department of Medicine, Tulane University Health Sciences Center, New Orleans, LA 70112-2699, United States
| | - Robert T Jensen
- Digestive Diseases Branch, NIDDK, National Institutes of Health, Bethesda, MD 20892-1804, United States.
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Moody TW, Mantey SA, Moreno P, Nakamura T, Lacivita E, Leopoldo M, Jensen RT. ML-18 is a non-peptide bombesin receptor subtype-3 antagonist which inhibits lung cancer growth. Peptides 2015; 64:55-61. [PMID: 25554218 PMCID: PMC4397132 DOI: 10.1016/j.peptides.2014.12.005] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/04/2014] [Revised: 12/17/2014] [Accepted: 12/17/2014] [Indexed: 12/28/2022]
Abstract
Bombesin receptor subtype (BRS)-3 is a G protein coupled receptor (GPCR) for the bombesin (BB)-family of peptides. BRS-3 is an orphan GPCR and little is known of its physiological role due to the lack of specific agonists and antagonists. PD168368 is a nonpeptide antagonist for the neuromedin B (NMB) receptor (R) whereas PD176252 is a nonpeptide antagonist for the gastrin releasing peptide (GRP) R and NMBR but not BRS-3. Here nonpeptide analogs of PD176252 e.g. the S-enantiomer ML-18, and the R-enantiomer, EMY-98, were investigated as BRS-3 antagonists using lung cancer cells. ML-18 and EMY-98 inhibited specific (125)I-BA1 (DTyr-Gln-Trp-Ala-Val-βAla-His-Phe-Nle-NH2)BB(6-14) binding to NCI-H1299 lung cancer cells stably transfected with BRS-3 with IC50 values of 4.8 and >100μM, respectively. In contrast, ML-18 bound with lower affinity to the GRPR and NMBR with IC50 values of 16 and >100μM, respectively. ML-18 (16μM), but not its enantiomer EMY-98, inhibited the ability of 10nM BA1 to elevate cytosolic Ca(2+) in a reversible manner using lung cancer cells loaded with FURA2-AM. ML-18 (16μM), but not EMY-98, inhibited the ability of 100nM BA1 to cause tyrosine phosphorylation of the EGFR and ERK in lung cancer cells. ML-18 but not EMY-98 inhibited the proliferation of lung cancer cells. The results indicate that ML-18 is a nonpeptide BRS-3 antagonist that should serve as a template to improve potency and selectivity.
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Affiliation(s)
- Terry W Moody
- Department of Health and Human Services, National Cancer Institute, Center for Cancer Research, Office of the Director, Bethesda, MD 20892, USA.
| | - Samuel A Mantey
- National Institute of Diabetes, Digestive and Kidney Disease, Digestive Diseases Branch, Bethesda, MD 20892, USA
| | - Paola Moreno
- National Institute of Diabetes, Digestive and Kidney Disease, Digestive Diseases Branch, Bethesda, MD 20892, USA
| | - Taichi Nakamura
- National Institute of Diabetes, Digestive and Kidney Disease, Digestive Diseases Branch, Bethesda, MD 20892, USA
| | - Enza Lacivita
- Dipartimento di Farmacia, Scienze del Farmaco, Universita degli Studi di Bari "A. Moro", Bari, Italy
| | - Marcello Leopoldo
- Dipartimento di Farmacia, Scienze del Farmaco, Universita degli Studi di Bari "A. Moro", Bari, Italy
| | - Robert T Jensen
- National Institute of Diabetes, Digestive and Kidney Disease, Digestive Diseases Branch, Bethesda, MD 20892, USA
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Boughton C, Patel S, Thompson E, Patterson M, Curtis A, Amin A, Chen K, Ghatei M, Bloom S, Murphy K. Neuromedin B stimulates the hypothalamic–pituitary–gonadal axis in male rats. ACTA ACUST UNITED AC 2013; 187:6-11. [DOI: 10.1016/j.regpep.2013.10.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2013] [Revised: 09/30/2013] [Accepted: 10/01/2013] [Indexed: 01/13/2023]
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Gastrin-releasing peptide receptor signaling in the integration of stress and memory. Neurobiol Learn Mem 2013; 112:44-52. [PMID: 24001571 DOI: 10.1016/j.nlm.2013.08.013] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2013] [Revised: 08/22/2013] [Accepted: 08/23/2013] [Indexed: 12/13/2022]
Abstract
Neuropeptides act as signaling molecules that regulate a range of aspects of brain function. Gastrin-releasing peptide (GRP) is a 27-amino acid mammalian neuropeptide, homolog of the amphibian peptide bombesin. GRP acts by binding to the GRP receptor (GRPR, also called BB2), a member of the G-protein coupled receptor (GPCR) superfamily. GRP produced by neurons in the central nervous system (CNS) plays a role in synaptic transmission by activating GRPRs located on postsynaptic membranes, influencing several aspects of brain function. Here we review the role of GRP/GRPR as a system mediating both stress responses and the formation and expression of memories for fearful events. GRPR signaling might integrate the processing of stress and fear with synaptic plasticity and memory, serving as an important component of the set of neurobiological systems underlying the enhancement of memory storage by aversive information.
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Sayegh AI. The Role of Bombesin and Bombesin-Related Peptides in the Short-term Control of Food Intake. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2013; 114:343-70. [DOI: 10.1016/b978-0-12-386933-3.00010-8] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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Accardo A, Mansi R, Salzano G, Morisco A, Aurilio M, Parisi A, Maione F, Cicala C, Ziaco B, Tesauro D, Aloj L, De Rosa G, Morelli G. Bombesin peptide antagonist for target-selective delivery of liposomal doxorubicin on cancer cells. J Drug Target 2012; 21:240-249. [PMID: 23167653 DOI: 10.3109/1061186x.2012.741138] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
PURPOSE This study addresses novel peptide modified liposomal doxorubicin to specifically target tissues overexpressing bombesin (BN) receptors. METHODS DOTA-(AEEA)2-peptides containing the [7-14]bombesin and the new BN-AA1 sequence have been synthesized to compare their binding properties and in serum stabilities. The amphiphilic peptide derivative (MonY-BN-AA1) containing BN-AA1, a hydrophobic moiety, polyethylenglycole (PEG), and diethylenetriaminepentaacetate (DTPA), has been synthesized. Liposomes have been obtained by mixing of MonY-BN-AA1 with 1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC). RESULTS Both 111In labeled peptide derivatives present nanomolar Kd to PC-3 cells. 177Lu labeled peptide DOTA-(AEEA)2-BN-AA1 is very stable (half-life 414.1 h), while DOTA-(AEEA)2-BN, shows a half-life of 15.5 h. In vivo studies on the therapeutic efficacy of DSPC/MonY-BN-AA1/Dox in comparison to DSPC/MonY-BN/Dox, were performed in PC-3 xenograft bearing mice. Both formulations showed similar tumor growth inhibition (TGI) compared to control animals treated with non-targeted DSPC/Dox liposomes or saline solution. For DSPC/MonY-BN-AA1/Dox the maximum effect was observed 19 days after treatment. CONCLUSIONS DSPC/MonY-BN-AA1/Dox nanovectors confirm the ability to selectively target and provide therapeutic efficacy in mice. The lack of receptor activation and possible acute biological side effects provided by using the AA1 antagonist bombesin sequence should provide safe working conditions for further development of this class of drug delivery vehicles.
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Affiliation(s)
- Antonella Accardo
- a CIRPeB, Department of Biological Sciences & IBB CNR, University of Naples "Federico II" , Napoli, Italy.,b Invectors srl , Napoli, Italy
| | - Rosalba Mansi
- c Division of Radiological Chemistry, University Hospital Basel , Basel, Switzerland
| | - Giuseppina Salzano
- d Department of Pharmaceutical and Toxicological Chemistry, University of Naples "Federico II" , Napoli, Italy
| | - Anna Morisco
- e Department of Nuclear Medicine, Istituto Nazionale per lo Studio e la Cura dei Tumori , Fondazione "G. Pascale", Napoli, Italy
| | - Michela Aurilio
- e Department of Nuclear Medicine, Istituto Nazionale per lo Studio e la Cura dei Tumori , Fondazione "G. Pascale", Napoli, Italy
| | - Antonio Parisi
- f Department of Experimental Pharmacology, University of Naples "Federico II" , Napoli, Italy
| | - Francesco Maione
- f Department of Experimental Pharmacology, University of Naples "Federico II" , Napoli, Italy
| | - Carla Cicala
- f Department of Experimental Pharmacology, University of Naples "Federico II" , Napoli, Italy
| | | | - Diego Tesauro
- a CIRPeB, Department of Biological Sciences & IBB CNR, University of Naples "Federico II" , Napoli, Italy.,b Invectors srl , Napoli, Italy
| | - Luigi Aloj
- e Department of Nuclear Medicine, Istituto Nazionale per lo Studio e la Cura dei Tumori , Fondazione "G. Pascale", Napoli, Italy
| | - Giuseppe De Rosa
- d Department of Pharmaceutical and Toxicological Chemistry, University of Naples "Federico II" , Napoli, Italy
| | - Giancarlo Morelli
- a CIRPeB, Department of Biological Sciences & IBB CNR, University of Naples "Federico II" , Napoli, Italy.,b Invectors srl , Napoli, Italy
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14
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Roesler R, Schwartsmann G. Gastrin-releasing peptide receptors in the central nervous system: role in brain function and as a drug target. Front Endocrinol (Lausanne) 2012; 3:159. [PMID: 23251133 PMCID: PMC3523293 DOI: 10.3389/fendo.2012.00159] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2012] [Accepted: 11/23/2012] [Indexed: 11/13/2022] Open
Abstract
Neuropeptides acting on specific cell membrane receptors of the G protein-coupled receptor (GPCR) superfamily regulate a range of important aspects of nervous and neuroendocrine function. Gastrin-releasing peptide (GRP) is a mammalian neuropeptide that binds to the GRP receptor (GRPR, BB2). Increasing evidence indicates that GRPR-mediated signaling in the central nervous system (CNS) plays an important role in regulating brain function, including aspects related to emotional responses, social interaction, memory, and feeding behavior. In addition, some alterations in GRP or GRPR expression or function have been described in patients with neurodegenerative, neurodevelopmental, and psychiatric disorders, as well as in brain tumors. Findings from preclinical models are consistent with the view that the GRPR might play a role in brain disorders, and raise the possibility that GRPR agonists might ameliorate cognitive and social deficits associated with neurological diseases, while antagonists may reduce anxiety and inhibit the growth of some types of brain cancer. Further preclinical and translational studies evaluating the potential therapeutic effects of GRPR ligands are warranted.
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Affiliation(s)
- Rafael Roesler
- Laboratory of Neuropharmacology and Neural Tumor Biology, Department of Pharmacology, Institute for Basic Health Sciences, Federal University of Rio Grande do SulPorto Alegre, Brazil
- Cancer Research Laboratory, University Hospital Research Center (CPE-HCPA), Federal University of Rio Grande do SulPorto Alegre, Brazil
- National Institute for Translational MedicinePorto Alegre, Brazil
- *Correspondence: Rafael Roesler, Laboratory of Neuropharmacology and Neural Tumor Biology, Department of Pharmacology, Institute for Basic Health Sciences, Federal University of Rio Grande do Sul, 90050-170 Porto Alegre, Rio Grande do Sul, Brazil. e-mail:
| | - Gilberto Schwartsmann
- Cancer Research Laboratory, University Hospital Research Center (CPE-HCPA), Federal University of Rio Grande do SulPorto Alegre, Brazil
- National Institute for Translational MedicinePorto Alegre, Brazil
- Department of Internal Medicine, School of Medicine, Federal University of Rio Grande do SulPorto Alegre, Brazil
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15
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Moody TW, Sancho V, di Florio A, Nuche-Berenguer B, Mantey S, Jensen RT. Bombesin receptor subtype-3 agonists stimulate the growth of lung cancer cells and increase EGF receptor tyrosine phosphorylation. Peptides 2011; 32:1677-1684. [PMID: 21712056 PMCID: PMC3152616 DOI: 10.1016/j.peptides.2011.06.011] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2011] [Revised: 06/13/2011] [Accepted: 06/13/2011] [Indexed: 10/18/2022]
Abstract
The effects of bombesin receptor subtype-3 (BRS-3) agonists were investigated on lung cancer cells. The BRS-3 agonist (DTyr(6), (Ala(11), Phe(13), Nle(14)) bombesin(6-14) (BA1), but not gastrin releasing peptide (GRP) or neuromedin B (NMB) increased significantly the clonal growth of NCI-H1299 cells stably transfected with BRS-3 (NCI-H1299-BRS-3). Also, BA1 addition to NCI-H727 or NCI-H1299-BRS-3 cells caused Tyr(1068) phosphorylation of the epidermal growth factor receptor (EGFR). Similarly, (DTyr(6), R-Apa(11), Phe(13), Nle(14)) bombesin(6-14) (BA2) and (DTyr(6), R-Apa(11), 4-Cl,Phe(13), Nle(14)) bombesin(6-14) (BA3) but not gastrin releasing peptide (GRP) or neuromedin B (NMB) caused EGFR transactivation in NCI-H1299-BRS-3 cells. BA1-induced EGFR or ERK tyrosine phosphorylation was not inhibited by addition of BW2258U89 (BB(2)R antagonist) or PD168368 (BB(1)R antagonist) but was blocked by (DNal-Cys-Tyr-DTrp-Lys-Val-Cys-Nal)NH(2) (BRS-3 ant.). The BRS-3 ant. reduced clonal growth of NCI-H1299-BRS-3 cells. BA1, BA2, BA3 and BRS-3 ant. inhibit specific (125)I-BA1 binding to NCI-H1299-BRS-3 cells with an IC(50) values of 1.1, 21, 15 and 750nM, respectively. The ability of BRS-3 to regulate EGFR transactivation in NCI-H1299-BRS-3 cells was reduced by AG1478 or gefitinib (EGFR tyrosine kinase inhibitors), GM6001 (matrix metalloprotease inhibitor), PP2 (Src inhibitor), N-acetylcysteine (anti-oxidant), Tiron (superoxide scavenger) and DPI (NADPH oxidase inhibitor). These results demonstrate that BRS-3 agonists may stimulate lung cancer growth as a result of EGFR transactivation and that the transactivation is regulated by BRS-3 in a Src-, reactive oxygen and matrix metalloprotease-dependent manner.
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Affiliation(s)
- Terry W Moody
- Department of Health and Human Services, National Cancer Institute, Center for Cancer Research, Office of Director, Bethesda, MD 20892, USA.
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16
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Naposomes: a new class of peptide-derivatized, target-selective multimodal nanoparticles for imaging and therapeutic applications. Ther Deliv 2011; 2:235-57. [DOI: 10.4155/tde.10.86] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Modified supramolecular aggregates for selective delivery of contrast agents and/or drugs are examined with a focus on a new class of peptide-derivatized nanoparticles: naposomes. These nanoparticles are based on the co-aggregation of two different amphiphilic monomers that give aggregates of different shapes and sizes (micelles, vesicles and liposomes) with diameters ranging between 10 and 300 nm. Structural properties and in vitro and in vivo behaviors are discussed. For the high relaxitivity values (12–19 mM-1s-1) and to detect for the presence of a surface-exposed peptide, the new peptide-derived supramolecular aggregates are very promising candidates as target-selective MRI contrast agents. The efficiency of surface-exposed peptides in homing these nanovectors to a specific target introduces promising new opportunities for the development of diagnostic and therapeutic agents with high specificity toward the biological target and reduced toxic side effects on nontarget organs.
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17
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The gastrin-releasing peptide system in the spinal cord mediates masculine sexual function. Anat Sci Int 2010; 86:19-29. [DOI: 10.1007/s12565-010-0097-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2010] [Accepted: 09/29/2010] [Indexed: 10/18/2022]
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18
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Accardo A, Mansi R, Morisco A, Mangiapia G, Paduano L, Tesauro D, Radulescu A, Aurilio M, Aloj L, Arra C, Morelli G. Peptide modified nanocarriers for selective targeting of bombesin receptors. MOLECULAR BIOSYSTEMS 2010; 6:878-87. [DOI: 10.1039/b923147a] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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González N, Nakagawa T, Mantey SA, Sancho V, Uehara H, Katsuno T, Jensen RT. Molecular basis for the selectivity of the mammalian bombesin peptide, neuromedin B, for its receptor. J Pharmacol Exp Ther 2009; 331:265-276. [PMID: 19628633 PMCID: PMC2766219 DOI: 10.1124/jpet.109.154245] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2009] [Accepted: 07/22/2009] [Indexed: 11/22/2022] Open
Abstract
The mammalian bombesin (Bn) peptides, neuromedin B (NMB) and gastrin-releasing peptide (GRP), have widespread actions in many tissues, and their effects are mediated by two closely related G-protein-coupled receptors, the NMBR and GRPR. Little is known about the structural determinants of NMBR selectivity for NMB, in contrast to GRP selectivity for the GRPR, which has been extensively studied. To provide insight, chimeric NMBR-GRPR loss-of-affinity and gain-of-affinity mutants were made, as well as NH(2)-terminally truncated NMBR and point mutants using site-directed mutagenesis. Receptors were expressed in Balb-3T3-cells or CHOP cells, and affinities were determined. NMB had 115-fold greater affinity for NMBR than GRPR. Receptor-chimeric studies showed that NMBR selectivity for NMB was primarily determined by differences in the third extracellular (EC3) regions of GRPR-NMBR and adjacent upper-transmembrane-5 (TM5) region. In this region, 24 NMB gain-of-affinity GRPR mutants or NMBR loss-of-affinity point/combination mutants were made. Three gain-of-affinity mutant GRPRs [[A198I] (EC3), [H202Q] (EC3), [S215I] (upper TM5)] had increased NMB affinity (2.4-21-fold), and these results were confirmed with NMBR loss-of-affinity mutants [I199A,Q203H,I215S-NMBR]. The combination mutant [A198I,S215]GRPR had the greatest effect causing a complete NMB gain-of-affinity. The importance of differences at position 199NMBR or 203NMBR was studied by substituting amino acids with various properties. Our results show that NMBR selectivity for NMB is due to differences in the EC3 of NMBR-GRPR and the adjacent upper-TM5 region. Within these regions, isoleucines in NMBR [position 199 (EC3)] (instead of A198GRPR) and in 215NMBR (TM5) (instead of S214GRPR), as well as Q203NMBR (instead of H202GRPR) are responsible for high NMB-affinity/selectivity of NMBR. The effect at position 199 is primarily due to differences in hydrophobicity of the substitution, whereas steric factors and charge of the substitution at position 203 were important determinants of NMB selectivity.
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Affiliation(s)
- Nieves González
- Digestive Diseases Branch, NIDDK, NIH, Bethesda, MD 20892-1804, USA
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20
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Expression of GRP and its receptor is associated with improved survival in patients with colon cancer. Clin Exp Metastasis 2009; 26:663-71. [PMID: 19430935 DOI: 10.1007/s10585-009-9265-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2009] [Accepted: 04/22/2009] [Indexed: 12/23/2022]
Abstract
Epithelial cells lining the adult human colon do not normally express gastrin releasing peptide (GRP) or its receptor (GRPR), but both can be up regulated post malignant transformation. However, controversy exists as to the contribution these proteins make to tumor cell behavior once present. Since GRPR activation promotes proliferation, it has been assumed that their aberrant expression promotes colon cancer (CC) growth and progression. Yet we have contended that when expressed, GRP/GRPR benefits the host since in vitro studies demonstrate they enhance tumor cell attachment to the extracellular matrix and promote CC cytolysis by natural killer lymphocytes. Thus the aim of this study was to ascertain the effect of aberrant GRP/GRPR expression on patient survival. To do this we identified all CC diagnosed at a single institution from 1998 to 2002 that were classified as AJCC stage II or III (n = 88); of these 50 (57%) had sufficient tissues remaining for study. GRP/GRPR expression and natural killer cell density were determined immunohistochemically at the leading edge of each CC, and survival assessed by Kaplan Meier analysis. Expression of high levels of GRPR alone, or both GRP and GRPR, was associated with delayed CC recurrence (14.1-17.0 months, respectfully; P = 0.005) and increased survival (10.1-13.1 months, respectfully; P = 0.0124). CC expressing GRP/GRPR were associated with significantly fewer lymph node metastases than tumors not expressing these proteins, and contained significantly more CD16 + natural killer cells, than tumors not expressing these proteins. These findings demonstrate that patients whose CC express GRPR are associated with a survival advantage as compared to those whose CC do not express these proteins.
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Abstract
The lumbar spinal cord contains local neural circuits that are important in regulating male sexual behaviours, but the molecular mechanisms underlying these systems remain elusive. Gastrin-releasing peptide (GRP) is a member of the bombesin-like peptide family first isolated from the porcine stomach. Despite extensive pharmacological studies on the activity of bombesin-like peptides administered to mammals, little is known about the physiological functions of GRP in the spinal cord. We review recent findings on a system of neurones in the upper lumbar spinal cord, within the recently reported ejaculation generator, projecting axons containing GRP to the lower lumbar spinal cord and innervating regions known to control erection and ejaculation.
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Affiliation(s)
- H Sakamoto
- Department of Anatomy and Neurobiology, Kyoto Prefectural University of Medicine, Kyoto, Japan.
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22
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Degan S, Lopez GY, Kevill K, Sunday ME. Gastrin-releasing peptide, immune responses, and lung disease. Ann N Y Acad Sci 2009; 1144:136-47. [PMID: 19076373 DOI: 10.1196/annals.1418.022] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Gastrin-releasing peptide (GRP) is produced by pulmonary neuroendocrine cells (PNECs), with highest numbers of GRP-positive cells present in fetal lung. Normally GRP-positive PNECs are relatively infrequent after birth, but PNEC hyperplasia is frequently associated with chronic lung diseases. To address the hypothesis that GRP mediates chronic lung injury, we present the cumulative evidence implicating GRP in bronchopulmonary dysplasia (BPD), the chronic lung disease of premature infants who survive acute respiratory distress syndrome. The availability of well-characterized animal models of BPD was a critical tool for demonstrating that GRP plays a direct role in the early pathogenesis of this disease. Potential mechanisms by which GRP contributes to injury are analyzed, with the main focus on innate immunity. Autoreactive T cells may contribute to lung injury late in the course of disease. A working model is proposed with GRP triggering multiple cell types in both the innate and adaptive immune systems, promoting cascades culminating in chronic lung disease. These observations represent a paradigm shift in the understanding of the early pathogenesis of BPD, and suggest that GRP blockade could be a novel treatment to prevent this lung disease in premature infants.
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Affiliation(s)
- Simone Degan
- Department of Pathology, Duke University Medical Center, Durham, NC 27710, USA
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Abstract
PURPOSE OF REVIEW This review will highlight recent advances in the understanding of molecular mechanisms by which mammalian bombesin receptors are regulated and which intracellular signaling pathways have been characterized to mediate agonist-dependent receptor biological effects. RECENT FINDINGS Mammalian bombesin receptors have been demonstrated to be involved in a larger array of physiological and pathophysiological conditions than previously reported. Pharmacological experiments in vitro and in vivo as well as utilization of animals genetically deficient of the gastrin-releasing peptide receptor demonstrated roles in memory and fear behavior, lung development and injury, small intestinal cell repair, autocrine tumor growth, and mediating signals for pruritus and penile reflexes. Intracellular signaling studies predominantly of the gastrin-releasing peptide receptor owing to its frequent overexpression in some human malignancies showed that PI3 kinase activation is an important mechanism of cell proliferation. Tumor cell treatment including gastrin-releasing peptide receptor antagonists combined with inhibition of epidermal growth factor receptor resulted in an additive effect on blocking cell proliferation. Novel molecular mechanisms of the orphan bombesin receptor subtype-3 and gastrin-releasing peptide receptor gene regulation have been elucidated. SUMMARY Inhibition of gastrin-releasing peptide receptor signaling in human malignancies represents an attractive target for pharmacological treatment. Novel functions of bombesin related peptides have been identified including processes in the central nervous system, lung and intestinal tract.
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Affiliation(s)
- H Christian Weber
- Boston University School of Medicine, Section of Gastroenterology, Boston, MA 02118, USA.
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24
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Thomas R, Chen J, Roudier MM, Vessella RL, Lantry LE, Nunn AD. In vitro binding evaluation of 177Lu-AMBA, a novel 177Lu-labeled GRP-R agonist for systemic radiotherapy in human tissues. Clin Exp Metastasis 2008; 26:105-19. [PMID: 18975117 DOI: 10.1007/s10585-008-9220-0] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2008] [Accepted: 10/08/2008] [Indexed: 12/31/2022]
Abstract
Members of the gastrin-releasing peptide (GRP) family and its analogs bombesin (BBN) have been implicated in the biology of several human cancers including prostate, breast, colon and lung. To date, three mammalian GRP/BBN receptor subtypes have been cloned and characterized: the neuromedin B receptor (NMBR), the GRP receptor (GRPR) and the BBN-receptor subtype 3 (BB(3)). The fourth BBN receptor subtype, BB(4), has only been identified in amphibian and at present no mammalian equivalent of this receptor has been described. GRPR analogs have been used as carriers to deliver drugs, radionuclides and cytotoxins to target various cancer types that are GRPR positive. We investigated the in vitro binding properties of (177)Lu-AMBA, a novel radiolabelled BBN analog currently undergoing clinical trial as systemic radiotherapy for hormone refractory prostate cancer (HRPC) patients. Pharmacological analyses of the (177)Lu-AMBA was determined using in vitro binding studies using membrane target system containing specific receptor subtypes. We investigated the distribution of binding sites for (177)Lu-AMBA by receptor autoradiography on human neoplastic and non-neoplastic tissues. Pharmacological characterizations of (177)Lu-AMBA shows, high affinity towards NMB and GRP receptors, while little or no affinity towards BB(3) receptor. Among the 40 different types of non-neoplastic tissues tested seven of them showed limited but specific binding of (177)Lu-AMBA. Fourteen of 17 primary prostate cancers, six of 13 primary breast cancers expressed binding sites for (177)Lu-AMBA. Furthermore, no apparent differences in (177)Lu-AMBA-binding sites expression were observed between matched pairs (primary vs. secondary) of prostate and breast cancer tissues. These data represent the molecular basis for clinical applications of (177)Lu-AMBA for diagnosis and treatment of GRP-R and NMB-R positive tumors.
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Affiliation(s)
- Regi Thomas
- Discovery Biology, Ernst Felder Laboratories, Bracco Research USA, Princeton, NJ 08540, USA.
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25
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Chinnappan D, Qu X, Xiao D, Ratnasari A, Weber HC. Human gastrin-releasing peptide receptor gene regulation requires transcription factor binding at two distinct CRE sites. Am J Physiol Gastrointest Liver Physiol 2008; 295:G153-G162. [PMID: 18483184 PMCID: PMC2494719 DOI: 10.1152/ajpgi.00036.2008] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Ectopic expression of the gastrin-releasing peptide (GRP) receptor (GRP-R) occurs frequently in human malignancies of the gastrointestinal tract. Owing to paracrine and autocrine interaction with its specific high-affinity ligand GRP, tumor cell proliferation, migration, and invasion might ensue. Here we provide the first insights regarding molecular mechanisms of GRP-R regulation in gastrointestinal cancer cells. We identified by EMSA and chromatin immunoprecipitation assays two cAMP response element (CRE) binding sites that recruited transcription factor CRE binding protein (CREB) to the human GRP-R promoter. Transfection studies with a wild-type human GRP-R promoter reporter and corresponding CRE mutants showed that both CRE sites are critical for basal transcriptional activation in gastrointestinal cancer cells. Forced expression of cAMP-dependent effectors CREB and PKA resulted in robust upregulation of human GRP-R transcriptional activity, and this overexpression strictly required intact wild-type CRE sites. Direct cAMP stimulation with forskolin resulted in enhanced human GRP-R promoter activity only in HuTu-80 cells, but not in Caco-2 cells, coinciding with forskolin-induced CREB phosphorylation occurring only in HuTu-80 but not Caco-2 cells. In summary, CREB is a critical regulator of human GRP-R expression in gastrointestinal cancer and might be activated through different upstream intracellular pathways.
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Affiliation(s)
- Dharmaraj Chinnappan
- Boston University School of Medicine, Section of Gastroenterology, Boston, Massachusetts
| | - Xiangping Qu
- Boston University School of Medicine, Section of Gastroenterology, Boston, Massachusetts
| | - Dongmei Xiao
- Boston University School of Medicine, Section of Gastroenterology, Boston, Massachusetts
| | - Anita Ratnasari
- Boston University School of Medicine, Section of Gastroenterology, Boston, Massachusetts
| | - H. Christian Weber
- Boston University School of Medicine, Section of Gastroenterology, Boston, Massachusetts
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26
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Moody TW, Pradhan T, Mantey SA, Jensen RT, Dyba M, Moody D, Tarasova NI, Michejda CJ. Bombesin marine toxin conjugates inhibit the growth of lung cancer cells. Life Sci 2008; 82:855-861. [PMID: 18336841 PMCID: PMC2695325 DOI: 10.1016/j.lfs.2008.01.019] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2007] [Revised: 01/14/2008] [Accepted: 01/29/2008] [Indexed: 11/30/2022]
Abstract
Hemiasterlin (Hem) and dolastatin (Dol) are marine natural products which are cytotoxic for cancer cells. Hem, a tripeptide, and Dol, a hexapeptide, were conjugated with linkers (L) to the universal BB agonist DPhe-Gln-Trp-Ala-Val-betaAla-His-Phe-Nle-NH2(BA1) and the effects of the Hem-BB and Dol-BB conjugates investigated on NCI-H1299 lung cancer cells. Hem-LA-BA1 and Hem-LB-BA1 inhibited specific (125I-Tyr4)BB binding to NCI-H1299 cells, which have BB2 receptors (R), with IC50 values of 15 and 25 nM, respectively. Addition of Hem-LA-BA1 and Hem-LB-BA1 to Fura-2 AM loaded cells containing BB2R, caused elevated cytosolic Ca2+. In a growth assay, Hem-LA-BA1 and Hem-LB-BA1 inhibited the proliferation of NCI-H1299 cells. Dol-succinamide (Dols)-LD-BA1 and Dols-LE-BA1 bound with high affinity to NCI-H1299 cells and elevated cytosolic Ca2+, but did not inhibit the proliferation of NCI-H1299 cells. Also, Hem-LA-BA1 inhibited 125I-DTyr-Gln-Trp-Ala-Val-betaAla-His-Phe-Nle-NH2 (BA2) binding to Balb/3T3 cells transfected with BB1R or BB2R as well as with BRS-3 with IC50 values of 130, 8, and 540 nM, respectively. These results show that Hem-BB conjugates are cytotoxic for cancer cells containing BB2R.
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Affiliation(s)
- Terry W Moody
- Department of Health and Human Services, NCI Office of the Director, CCR, Bethesda, MD 20892 USA.
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27
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Jensen RT, Battey JF, Spindel ER, Benya RV. International Union of Pharmacology. LXVIII. Mammalian bombesin receptors: nomenclature, distribution, pharmacology, signaling, and functions in normal and disease states. Pharmacol Rev 2008; 60:1-42. [PMID: 18055507 PMCID: PMC2517428 DOI: 10.1124/pr.107.07108] [Citation(s) in RCA: 395] [Impact Index Per Article: 23.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
The mammalian bombesin receptor family comprises three G protein-coupled heptahelical receptors: the neuromedin B (NMB) receptor (BB(1)), the gastrin-releasing peptide (GRP) receptor (BB(2)), and the orphan receptor bombesin receptor subtype 3 (BRS-3) (BB(3)). Each receptor is widely distributed, especially in the gastrointestinal (GI) tract and central nervous system (CNS), and the receptors have a large range of effects in both normal physiology and pathophysiological conditions. The mammalian bombesin peptides, GRP and NMB, demonstrate a broad spectrum of pharmacological/biological responses. GRP stimulates smooth muscle contraction and GI motility, release of numerous GI hormones/neurotransmitters, and secretion and/or hormone release from the pancreas, stomach, colon, and numerous endocrine organs and has potent effects on immune cells, potent growth effects on both normal tissues and tumors, potent CNS effects, including regulation of circadian rhythm, thermoregulation; anxiety/fear responses, food intake, and numerous CNS effects on the GI tract as well as the spinal transmission of chronic pruritus. NMB causes contraction of smooth muscle, has growth effects in various tissues, has CNS effects, including effects on feeding and thermoregulation, regulates thyroid-stimulating hormone release, stimulates various CNS neurons, has behavioral effects, and has effects on spinal sensory transmission. GRP, and to a lesser extent NMB, affects growth and/or differentiation of various human tumors, including colon, prostate, lung, and some gynecologic cancers. Knockout studies show that BB(3) has important effects in energy balance, glucose homeostasis, control of body weight, lung development and response to injury, tumor growth, and perhaps GI motility. This review summarizes advances in our understanding of the biology/pharmacology of these receptors, including their classification, structure, pharmacology, physiology, and role in pathophysiological conditions.
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Affiliation(s)
- R T Jensen
- Digestive Diseases Branch, National Institute of Diabetes Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, USA.
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28
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Ladenheim EE, Hamilton NL, Behles RR, Bi S, Hampton LL, Battey JF, Moran TH. Factors contributing to obesity in bombesin receptor subtype-3-deficient mice. Endocrinology 2008; 149:971-8. [PMID: 18039774 PMCID: PMC2275361 DOI: 10.1210/en.2007-1319] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Mice with a targeted disruption of bombesin receptor subtype-3 (BRS-3 KO) develop hyperphagia, obesity, hypertension, and impaired glucose metabolism. However, the factors contributing to their phenotype have not been clearly established. To determine whether their obesity is a result of increased food intake or a defect in energy regulation, we matched the caloric intake of BRS-3 KO mice to wild-type (WT) ad libitum (ad lib)-fed controls over 21 wk. Although BRS-3 KO ad lib-fed mice were 29% heavier, the body weights of BRS-3 KO pair-fed mice did not differ from WT ad lib-fed mice. Pair-feeding BRS-3 KO mice normalized plasma insulin but failed to completely reverse increased adiposity and leptin levels. Hyperphagia in ad lib-fed KO mice was due to an increase in meal size without a compensatory decrease in meal frequency resulting in an increase in total daily food intake. An examination of neuropeptide Y, proopiomelanocortin, and agouti-related peptide gene expression in the arcuate nucleus revealed that BRS-3 KO mice have some deficits in their response to energy regulatory signals. An evaluation of the satiety effects of cholecystokinin, bombesin, and gastrin-releasing peptide found no differences in feeding suppression by these peptides. We conclude that hyperphagia is a major factor leading to increased body weight and hyperinsulinemia in BRS-3 KO mice. However, our finding that pair-feeding did not completely normalize fat distribution and plasma leptin levels suggests there is also a metabolic dysregulation that may contribute to, or sustain, their obese phenotype.
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Affiliation(s)
- Ellen E Ladenheim
- Johns Hopkins University School of Medicine, Department of Psychiatry and Behavioral Sciences, Baltimore, Maryland 21205, USA.
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Baldwin GS, Patel O, Shulkes A. Phylogenetic analysis of the sequences of gastrin-releasing peptide and its receptors: Biological implications. ACTA ACUST UNITED AC 2007; 143:1-14. [PMID: 17395282 DOI: 10.1016/j.regpep.2007.02.007] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2006] [Revised: 02/04/2007] [Accepted: 02/06/2007] [Indexed: 11/17/2022]
Abstract
The many biological activities of the hormone gastrin-releasing peptide (GRP), including stimulation of acid secretion and of tumour growth, are mediated by the gastrin-releasing peptide receptor (GRP-R). Here sequence comparisons are utilised to investigate the likely bioactive regions of the 125 amino acid GRP precursor and of GRP-R. Comparison of the sequences of the GRP precursor from 21 species revealed homology not only in the GRP region between amino acids 1 and 30, but also in C-terminal regions from amino acids 43 to 97. This observation is consistent with recent reports that peptides derived from the C-terminal region are biologically active. Comparison of the GRP-R sequence with the related receptors NMB-R and BRS-3 revealed that the family could be distinguished from other G-protein coupled receptors by the presence of the motif GVSVFTLTALS at the cytoplasmic end of transmembrane helix 3. Comparison of the sequences of the GRP-R from 21 species revealed that the most highly conserved regions occurred in transmembrane helices 2, 3, 5, 6 and 7, and in the third intracellular loop. These results will be important in guiding future structure-function studies of the GRP precursor and of GRP receptors.
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Affiliation(s)
- Graham S Baldwin
- University of Melbourne, Department of Surgery, Austin Health, Studley Rd., Heidelberg, Victoria 3084, Australia.
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Cornelio DB, Roesler R, Schwartsmann G. Gastrin-releasing peptide receptor as a molecular target in experimental anticancer therapy. Ann Oncol 2007; 18:1457-66. [PMID: 17351255 DOI: 10.1093/annonc/mdm058] [Citation(s) in RCA: 169] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Over the last two decades, several lines of experimental evidence have suggested that the gastrin-releasing peptide (GRP) may act as a growth factor in many types of cancer. For that reason, gastrin-releasing peptide receptor (GRPR) antagonists have been developed as anticancer candidate compounds, exhibiting impressive antitumoral activity both in vitro and in vivo in various murine and human tumors. In this article, the GRPR cell surface expression profile in human malignancies is reviewed aiming at the identification of potential tumor types for future clinical trials with GRP analogues and antagonists. In this review, we summarize the current literature regarding the GRPR status in human malignancies. Source data were obtained by searching all published material available through Medline, PubMed and relevant articles from 1971 to 2006. The data available demonstrated a high expression of GRPRs in a large spectrum of human cancers, demonstrating the potential relevance of this intracellular signaling pathway in various human tumor models. The GRPR may be an interesting target for therapeutic intervention in human malignancies, as carriers for cytotoxins, immunotoxins or radioactive compounds, being also a potential tool for tumor detection.
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Affiliation(s)
- D B Cornelio
- Cancer Research Laboratory, Academic Hospital Research Center, Porto Alegre, Brazil
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31
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Yasufuku-Takano J, Nakajima S, Nakajima Y. Morphological and physiological properties of serotonergic neurons in dissociated cultures from the postnatal rat dorsal raphe nucleus. J Neurosci Methods 2007; 167:258-67. [PMID: 17920133 DOI: 10.1016/j.jneumeth.2007.08.018] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2007] [Revised: 08/23/2007] [Accepted: 08/23/2007] [Indexed: 11/30/2022]
Abstract
We have developed dissociated primary cultures of the dorsal raphe nucleus from postnatal 9-12-day-old rats. The nucleus was dissected out from brain slices, dissociated, and cultured over a glial feeder layer. Serotonin immunocytochemistry revealed that 62% of cultured neurons were serotonergic. There was no significant difference in diameters between serotonergic and non-serotonergic neurons. With the whole-cell patch-clamp method, cultured neurons were tested for responses to 8-hydroxydipropylaminotetraline (8-OH-DPAT, a selective agonist for 5-HT(1A)), and then treated with serotonin immunocytochemistry. Ninety-two percent of neurons responding to 8-OH-DPAT were serotonergic. These results were used to identify serotonergic neurons. In most cases, serotonergic neurons did not show spontaneous firings of action potentials. Constant current depolarizations elicited trains of action potentials that usually did not show marked adaptation. Application of 8-OH-DPAT inhibited action potential firing. The current-voltage relation of the 8-OH-DPAT-induced current indicated an inward rectification with its reversal potential near E(K). Serotonergic neurons were depolarized by phenylephrine, bombesin, and gastrin-releasing peptide. This culture system will serve as a useful tool for elucidating the cellular, physiological, and molecular properties of brain serotonergic neurons.
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Affiliation(s)
- Junko Yasufuku-Takano
- Department of Anatomy and Cell Biology, University of Illinois at Chicago, College of Medicine (M/C 512), 808 South Wood Street, Chicago, IL 60612, USA
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32
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Roesler R, Luft T, Schwartsmann G. Targeting the gastrin-releasing peptide receptor pathway to treat cognitive dysfunctionassociated with Alzheimer's Disease. Dement Neuropsychol 2007; 1:118-123. [PMID: 29213377 PMCID: PMC5619558 DOI: 10.1590/s1980-57642008dn10200002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Increasing evidence indicates that bombesin (BB)-like peptides (BLPs), such as
the gastrin-releasing peptide (GRP) and its receptor (GRPR), might play a role
in neurological and psychiatric disorders. The present study reviews findings
from animal and human studies suggesting that the GRPR should be considered a
target for the treatment of cognitive dysfunction in patients with Alzheimer’s
disease (AD). Abnormalities in GRPR-triggered signaling have been described in
both fibroblasts from patients with AD, and in transgenic mouse models of AD.
Pharmacological and genetic preclinical studies have indicated that BLPs and the
GRPR are importantly involved in regulating cognitive function. Moreover, drugs
acting at the GRPR have been shown to enhance memory and ameliorate cognitive
dysfunction in experimental models of amnesia associated with AD. Taken
together, these findings support the view that the GRPR is a novel therapeutic
target for the treatment of memory deficits associated with AD.
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Affiliation(s)
- Rafael Roesler
- Cellular and Molecular Neuropharmacology Research Group, Department of Pharmacology, Institute for Basic Health Sciences, Federal University of Rio Grande do Sul, 90046-900 Porto Alegre, RS, Brazil.,Cancer Research Laboratory, Academic Hospital Research Center, Federal University of Rio Grande do Sul, 90035-003 Porto Alegre, RS, Brazil
| | - Tatiana Luft
- Cellular and Molecular Neuropharmacology Research Group, Department of Pharmacology, Institute for Basic Health Sciences, Federal University of Rio Grande do Sul, 90046-900 Porto Alegre, RS, Brazil.,Department of Biochemistry, Institute for Basic Health Sciences, Federal University of Rio Grande do Sul, 90035-003 Porto Alegre, RS, Brazil
| | - Gilberto Schwartsmann
- Cancer Research Laboratory, Academic Hospital Research Center, Federal University of Rio Grande do Sul, 90035-003 Porto Alegre, RS, Brazil.,Department of Internal Medicine, Faculty of Medicine, Federal University of Rio Grande do Sul, 90035-003 Porto Alegre, RS, Brazil
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Ma L, Yu P, Veerendra B, Rold TL, Retzloff L, Prasanphanich A, Sieckman G, Hoffman TJ, Volkert WA, Smith CJ. In Vitro and In Vivo Evaluation of Alexa Fluor 680-Bombesin[7–14]NH2Peptide Conjugate, a High-Affinity Fluorescent Probe with High Selectivity for the Gastrin-Releasing Peptide Receptor. Mol Imaging 2007. [DOI: 10.2310/7290.2007.00013] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
- Lixin Ma
- From the Departments of Radiology, Internal Medicine, and Medical Pharmacology and Physiology; The Radiopharmaceutical Sciences Institute; and International Institute of Nano and Molecular Medicine, University of Missouri-Columbia School of Medicine; Department of Physics and Astronomy, University of Missouri-Columbia; University of Missouri Research Reactor Center, University of Missouri-Columbia; and Research Division, Harry S. Truman Memorial Veterans' Hospital, Columbia, MO
| | - Ping Yu
- From the Departments of Radiology, Internal Medicine, and Medical Pharmacology and Physiology; The Radiopharmaceutical Sciences Institute; and International Institute of Nano and Molecular Medicine, University of Missouri-Columbia School of Medicine; Department of Physics and Astronomy, University of Missouri-Columbia; University of Missouri Research Reactor Center, University of Missouri-Columbia; and Research Division, Harry S. Truman Memorial Veterans' Hospital, Columbia, MO
| | - Bhadrasetty Veerendra
- From the Departments of Radiology, Internal Medicine, and Medical Pharmacology and Physiology; The Radiopharmaceutical Sciences Institute; and International Institute of Nano and Molecular Medicine, University of Missouri-Columbia School of Medicine; Department of Physics and Astronomy, University of Missouri-Columbia; University of Missouri Research Reactor Center, University of Missouri-Columbia; and Research Division, Harry S. Truman Memorial Veterans' Hospital, Columbia, MO
| | - Tammy L. Rold
- From the Departments of Radiology, Internal Medicine, and Medical Pharmacology and Physiology; The Radiopharmaceutical Sciences Institute; and International Institute of Nano and Molecular Medicine, University of Missouri-Columbia School of Medicine; Department of Physics and Astronomy, University of Missouri-Columbia; University of Missouri Research Reactor Center, University of Missouri-Columbia; and Research Division, Harry S. Truman Memorial Veterans' Hospital, Columbia, MO
| | - Lauren Retzloff
- From the Departments of Radiology, Internal Medicine, and Medical Pharmacology and Physiology; The Radiopharmaceutical Sciences Institute; and International Institute of Nano and Molecular Medicine, University of Missouri-Columbia School of Medicine; Department of Physics and Astronomy, University of Missouri-Columbia; University of Missouri Research Reactor Center, University of Missouri-Columbia; and Research Division, Harry S. Truman Memorial Veterans' Hospital, Columbia, MO
| | - Adam Prasanphanich
- From the Departments of Radiology, Internal Medicine, and Medical Pharmacology and Physiology; The Radiopharmaceutical Sciences Institute; and International Institute of Nano and Molecular Medicine, University of Missouri-Columbia School of Medicine; Department of Physics and Astronomy, University of Missouri-Columbia; University of Missouri Research Reactor Center, University of Missouri-Columbia; and Research Division, Harry S. Truman Memorial Veterans' Hospital, Columbia, MO
| | - Gary Sieckman
- From the Departments of Radiology, Internal Medicine, and Medical Pharmacology and Physiology; The Radiopharmaceutical Sciences Institute; and International Institute of Nano and Molecular Medicine, University of Missouri-Columbia School of Medicine; Department of Physics and Astronomy, University of Missouri-Columbia; University of Missouri Research Reactor Center, University of Missouri-Columbia; and Research Division, Harry S. Truman Memorial Veterans' Hospital, Columbia, MO
| | - Timothy J. Hoffman
- From the Departments of Radiology, Internal Medicine, and Medical Pharmacology and Physiology; The Radiopharmaceutical Sciences Institute; and International Institute of Nano and Molecular Medicine, University of Missouri-Columbia School of Medicine; Department of Physics and Astronomy, University of Missouri-Columbia; University of Missouri Research Reactor Center, University of Missouri-Columbia; and Research Division, Harry S. Truman Memorial Veterans' Hospital, Columbia, MO
| | - Wynn A. Volkert
- From the Departments of Radiology, Internal Medicine, and Medical Pharmacology and Physiology; The Radiopharmaceutical Sciences Institute; and International Institute of Nano and Molecular Medicine, University of Missouri-Columbia School of Medicine; Department of Physics and Astronomy, University of Missouri-Columbia; University of Missouri Research Reactor Center, University of Missouri-Columbia; and Research Division, Harry S. Truman Memorial Veterans' Hospital, Columbia, MO
| | - Charles J. Smith
- From the Departments of Radiology, Internal Medicine, and Medical Pharmacology and Physiology; The Radiopharmaceutical Sciences Institute; and International Institute of Nano and Molecular Medicine, University of Missouri-Columbia School of Medicine; Department of Physics and Astronomy, University of Missouri-Columbia; University of Missouri Research Reactor Center, University of Missouri-Columbia; and Research Division, Harry S. Truman Memorial Veterans' Hospital, Columbia, MO
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Liu X, Carlisle DL, Swick MC, Gaither-Davis A, Grandis JR, Siegfried JM. Gastrin-releasing peptide activates Akt through the epidermal growth factor receptor pathway and abrogates the effect of gefitinib. Exp Cell Res 2007; 313:1361-72. [PMID: 17349623 DOI: 10.1016/j.yexcr.2007.01.016] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2006] [Revised: 12/22/2006] [Accepted: 01/26/2007] [Indexed: 11/28/2022]
Abstract
Gastrin-releasing peptide (GRP) is a mitogen for lung epithelial cells and initiates signaling through a G-protein-coupled receptor, gastrin-releasing peptide receptor (GRPR). Because GRPR transactivates the epidermal growth factor receptor (EGFR), we investigated induction by GRP of Akt, an EGFR-activated signaling pathway, and examined effects of GRP on viability of non-small cell lung carcinoma (NSCLC) cells exposed to the EGFR tyrosine kinase inhibitor gefitinib. GRP induced Akt activation primarily through c-Src-mediated transactivation of EGFR. Transfection of dominant-negative c-Src abolished GRP-induced EGFR and Akt activation. GRP induced release of amphiregulin, and pre-incubation with human amphiregulin neutralizing antibody eliminated GRP-induced Akt phosphorylation. Pretreatment with phosphatidylinositol 3-kinase (PI3K) inhibitor LY294002 completely blocked GRP-initiated Akt phosphorylation. These results suggest that GRP stimulates Akt activation primarily via c-Src activation, followed by extracellular release of the EGFR ligand amphiregulin, leading to the activation of EGFR and PI3K. Pretreatment of NSCLC cells with GRP resulted in an increase in the IC(50) of gefitinib of up to 9-fold; this protective effect was mimicked by the pretreatment of cells with amphiregulin and reversed by Akt or PI3K inhibition. GRP appears to rescue NSCLC cells exposed to gefitinib through release of amphiregulin and activation of the Akt pathway, suggesting GRPR and/or EGFR autocrine pathways in NSCLC cells may modulate therapeutic response to EGFR inhibitors.
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Affiliation(s)
- Xuwan Liu
- Department of Pharmacology, University of Pittsburgh Cancer Institute, University of Pittsburgh, Lab 2.7, 5117 Centre Ave., Pittsburgh, PA 15213, USA.
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Fujimura Y, Haruma K, Owen RL. Bombesin prevents the atrophy of Peyer's patches and the dysfunction of M cells in rabbits receiving long-term parenteral nutrition. JPEN J Parenter Enteral Nutr 2007; 31:75-85. [PMID: 17308247 DOI: 10.1177/014860710703100275] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
BACKGROUND Long-term parenteral nutrition (PN) induces atrophy of the gut-associated lymphoid tissue (GALT). We examined whether bombesin could ameliorate this atrophy of Peyer's patches and the down-regulation of particle transport by M cells, which was also observed in rabbits undergoing PN. METHODS Adult female rabbits were randomized into 6 groups to receive chow ad libitum, chow + bombesin, PN, or PN + bombesin (20 microg/kg, subcutaneously every 8 hours) for 2 or 4 weeks. At the end of each nutrition period, a laparotomy was performed under anesthesia and a suspension of 1 x 10(10)/mL of 0.5-microm fluorescent microspheres was injected into the lumen of intestinal segments containing Peyer's patches and incubated for 2 hours. After the incubation, segments were harvested and prepared for light microscopy, immunohistochemistry, fluorescent microscopy, and electron microscopy. RESULTS Long-term PN reduced the size of ileal Peyer's patches, the number of microspheres that was taken up into the follicle-associated epithelium of lymphoid nodules, and the area of Peyer's patch surface occupied by M cells. The number of intraepithelial lymphocytes within the follicle-associated epithelium near the perifollicular crypts of Peyer's patches was also reduced by long-term PN. These consequences were dramatically ameliorated by treatment with bombesin. No ultrastructural alteration of the M cells of Peyer's patches was found in the chow, the PN, or the PN + bombesin groups. CONCLUSIONS Bombesin prevents PN-induced atrophy of GALT, reduction of M cell numbers, and decrease in particulate transport by M cells during long-term PN. Bombesin may modulate the genesis of and particulate transport by M cells through stimulation of lymphoid cells in Peyer's patch epithelium near perifollicular crypts, where M cells and other constituents of lymphoid follicle epithelium are generated, thereby preserving mucosal immunity.
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Affiliation(s)
- Yoshinori Fujimura
- Department of Internal Medicine, Center for Gastroenterology and Endoscopy, Kawasaki Hospital, Kawasaki Medical School, Okayama, Japan.
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36
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Taglia L, Matusiak D, Matkowskyj KA, Benya RV. Gastrin-releasing peptide mediates its morphogenic properties in human colon cancer by upregulating intracellular adhesion protein-1 (ICAM-1) via focal adhesion kinase. Am J Physiol Gastrointest Liver Physiol 2007; 292:G182-90. [PMID: 16920698 DOI: 10.1152/ajpgi.00201.2006] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Gastrin-releasing peptide (GRP) and its receptor (GRPR) act as morphogens when expressed in colorectal cancer (CRC), promoting the assumption of a better differentiated phenotype by regulating cell motility in the context of remodeling and retarding tumor cell metastasis by enhancing cell-matrix attachment. Although we have shown that these processes are mediated by focal adhesion kinase (FAK), the downstream target(s) of GRP-induced FAK activation are not known. Since osteoblast differentiation is mediated by FAK-initiated upregulation of ICAM-1 (Nakayamada S, Okada Y, Saito K, Tamura M, Tanaka Y. J Biol Chem 278: 45368-45374, 2003), we determined whether GRP-induced activation of FAK alters ICAM-1 expression in CRC and, if so, determined the contribution of ICAM-1 to mediating GRP's morphogenic properties. Caco-2 and HT-29 cells variably express GRP/GRPR. These cells only express ICAM-1 when GRPR are present. In human CRC, GRPR and ICAM-1 are only expressed by better differentiated tumor cells, with ICAM-1 located at the basolateral membrane. ICAM-1 expression was only observed subsequent to GRPR signaling via FAK. To study the effect of ICAM-1 expression on tumor cell motility, CRC cells expressing GRP, GRPR, and ICAM-1 were cultured in the presence and absence of GRPR antagonist or monoclonal antibody to ICAM-1. CRC cells engaged in directed motility in the context of remodeling and were highly adherent to the extracellular matrix, only in the absence of antagonist or ICAM-1 antibody. These data indicate that GRP upregulation of ICAM-1 via FAK promotes tumor cell motility and attachment to the extracellular matrix.
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Affiliation(s)
- Lauren Taglia
- Department of Medicine, University of Illinois at Chicago, 840 South Wood St., Chicago, IL 60612, USA
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37
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Arora S. Role of neuropeptides in appetite regulation and obesity--a review. Neuropeptides 2006; 40:375-401. [PMID: 16935329 DOI: 10.1016/j.npep.2006.07.001] [Citation(s) in RCA: 296] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2006] [Revised: 06/17/2006] [Accepted: 07/07/2006] [Indexed: 01/27/2023]
Abstract
Obesity represents the most prevalent nutritional problem worldwide which in the long run predisposes to development of diabetes mellitus, hypertension, endometrial carcinoma, osteoarthritis, gall stones and cardiovascular diseases. Despite significant reductions in dietary fat consumption, the prevalence of obesity is on a rise and is taking on pandemic proportions. Obesity develops when energy intake exceeds energy expenditure over time. Recently, a close evolutionary relationship between the peripheral and hypothalamic neuropeptides has become apparent. The hypothalamus being the central feeding organ mediates regulation of short-term and long-term dietary intake via synthesis of various orexigenic and anorectic neuropeptides. The structure and function of many hypothalamic peptides (neuropeptide Y (NPY), melanocortins, agouti-related peptide (AGRP), cocaine and amphetamine regulated transcript (CART), melanin concentrating hormone (MCH), orexins have been characterized in rodent models The peripheral neuropeptides such as cholecystokinin (CCK), ghrelin, peptide YY (PYY3-36), amylin, bombesin regulate important gastrointestinal functions such as motility, secretion, absorption, provide feedback to the central nervous system on availability of nutrients and may play a part in regulating food intake. The pharmacological potential of several endogenous peripheral peptides released prior to, during and/or after feeding are being explored. Long-term regulation is provided by the main circulating hormones leptin and insulin. These systems implicated in hypothalamic appetite regulation provide potential targets for treatment of obesity which could potentially pass into clinical development in the next 5 years. This review summarizes various effects and interrelationship of these central and peripheral neuropeptides in metabolism, obesity and their potential role as targets for treatment of obesity.
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Affiliation(s)
- Sarika Arora
- Department of Biochemistry, Lady Hardinge Medical College, Shaheed Bhagat Singh Marg, Connaught Place, New Delhi, Delhi 110 001, India.
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38
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Ruginis T, Taglia L, Matusiak D, Lee BS, Benya RV. Consequence of gastrin-releasing peptide receptor activation in a human colon cancer cell line: a proteomic approach. J Proteome Res 2006; 5:1460-8. [PMID: 16739997 DOI: 10.1021/pr060005g] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Gastrin-releasing peptide (GRP) and its receptor (GRPR) are aberrantly up-regulated in colon cancer. When expressed, they act as morphogens, retaining tumor cells in a better differentiated state and retarding metastasis. To identify targets activated in response to GRPR signaling we studied Caco-2 and HT-29 cells, colon cancer cell lines that expresses GRPR as a function of confluence. Total cell protein was extracted from pre-confluent cells (expressing GRP/GRPR) cultured in serum-free media in the presence or absence of GRPR-specific antagonist; as well as from confluent cells that do not express GRPR. Overall, we identified 5 proteins that are specifically down-regulated after GRP/GRPR expression: Bach2, creatine kinase B, p47, and two that could not be identified; and 6 proteins that are up-regulated: gephyrin, HSP70, HP1, ICAM-1, ACAT, and one that could not be identified. These findings suggest that the mechanism(s) by which GRP/GRPR mediate its morphogenic effects in colon cancer involve the actions of a number of hitherto unappreciated proteins.
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Affiliation(s)
- Tom Ruginis
- Department of Medicine, University of Illinois at Chicago and Chicago Veterans Administration Medical Center (West Side Division), Chicago, Illinois 60612, USA
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39
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Park SU, Shin CY, Ryu JS, La HO, Park SY, Song HJ, Min YS, Kim DS, Sohn UD. Signal transduction of bombesin-induced circular smooth muscle cell contraction in cat esophagus. World J Gastroenterol 2006; 12:2259-63. [PMID: 16610033 PMCID: PMC4087658 DOI: 10.3748/wjg.v12.i14.2259] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To investigate the mechanism of bombesin-induced circular smooth muscle cell contraction in cat esophagus.
METHODS: Specific G protein or phospholipase C involved in cat esophagus contraction was identified, muscle cells were permeabilized with saponin. After permeabilization of muscle cells, the Gi3 antibody inhibited bombesin-induced smooth muscle cell contraction.
RESULTS: Incubation of permeabilized circular muscle cells with PLC-β3 antibody could inhibit bombesin-induced contraction. H-7, chelerythrine (PKC inhibitor) and genistein (protein tyrosine kinase inhibitor) inhibited bombesin-induced contraction, but DAG kinase inhibitor, R59949, could not inhibit it. To examine which mitogen-activated protein kinase (MAPK) was involved in bombesin-induced contraction, the specific MAPK inhibitors (MEK inhibitor, PD98059 and p38 MAPK inhibitor, SB202190) were used. Preincubation of PD98059 blocked the contraction induced by bombesin in a concentration-dependent manner. However, SB202190 had no effects on contraction.
CONCLUSION: Bombesin-induced circular muscle cell contraction in cat esophagus is madiated via a PKC or a PTK-dependent pathway or p44/p42 MAPK pathway.
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Affiliation(s)
- Sung-Uk Park
- Department of Pharmacology, College of Pharmacy, Chung Ang University, Seoul 156-756, Republic of Korea
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40
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Patel O, Shulkes A, Baldwin GS. Gastrin-releasing peptide and cancer. Biochim Biophys Acta Rev Cancer 2006; 1766:23-41. [PMID: 16490321 DOI: 10.1016/j.bbcan.2006.01.003] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2005] [Revised: 01/09/2006] [Accepted: 01/10/2006] [Indexed: 02/07/2023]
Abstract
Over the past 20 years, abundant evidence has been collected to suggest that gastrin-releasing peptide (GRP) and its receptors play an important role in the development of a variety of cancers. In fact, the detection of GRP and the GRP receptor in small cell lung carcinoma (SCLC), and the demonstration that anti-GRP antibodies inhibited proliferation in SCLC cell lines, established GRP as the prototypical autocrine growth factor. All forms of GRP are generated by processing of a 125-amino acid prohormone; recent studies indicate that C-terminal amidation of GRP18-27 is not essential for bioactivity, and that peptides derived from residues 31 to 125 of the prohormone are present in normal tissue and in tumors. GRP receptors can be divided into four classes, all of which belong to the 7 transmembrane domain family and bind GRP and/or GRP analogues with affinities in the nM range. Over-expression of GRP and its receptors has been demonstrated at both the mRNA and protein level in many types of tumors including lung, prostate, breast, stomach, pancreas and colon. GRP has also been shown to act as a potent mitogen for cancer cells of diverse origin both in vitro and in animal models of carcinogenesis. Other actions of GRP relevant to carcinogenesis include effects on morphogenesis, angiogenesis, cell migration and cell adhesion. Future prospects for the use of radiolabelled and cytotoxic GRP analogues and antagonists for cancer diagnosis and therapy appear promising.
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Affiliation(s)
- Oneel Patel
- University of Melbourne, Department of Surgery, Austin Health, Studley Rd., Heidelberg, Victoria 3084, Australia
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Smith CJ, Volkert WA, Hoffman TJ. Radiolabeled peptide conjugates for targeting of the bombesin receptor superfamily subtypes. Nucl Med Biol 2005; 32:733-40. [PMID: 16243649 DOI: 10.1016/j.nucmedbio.2005.05.005] [Citation(s) in RCA: 144] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2005] [Accepted: 05/17/2005] [Indexed: 10/25/2022]
Abstract
Research laboratories around the world are currently focusing their efforts toward the development of radiometallated, site-directed, diagnostic/therapeutic agents based upon small peptides such as octreotide, neurotensin, alpha-melanocyte stimulating hormone, vasointestinal peptide and others. Bombesin (BBN) or derivatives of bombesin are also of significant interest. Bombesin is a 14-amino-acid peptide with very high affinity for the BB2 or gastrin-releasing peptide receptor (GRPr). Over-expression of the GRPr on a variety of human cancers (i.e., breast, prostate, pancreatic, small cell lung, etc.) provides potential efficacy toward development of radiometallated BBN derivatives for targeting and, hence, diagnosis/treatment of these specific diseases. New derivatives are being developed that are also capable of targeting the BB1 and BB3 receptor subtypes that are over-expressed on cancer cells. This review highlights some of the more recent developments toward design of BBN receptor-specific radiopharmaceuticals that have taken place over the past 2 years.
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Affiliation(s)
- Charles J Smith
- Research Services, H.S. Truman Memorial VA Hospital, Columbia, MO 65201, USA
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42
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Nakagawa T, Hocart SJ, Schumann M, Tapia JA, Mantey SA, Coy DH, Tokita K, Katsuno T, Jensen RT. Identification of key amino acids in the gastrin-releasing peptide receptor (GRPR) responsible for high affinity binding of gastrin-releasing peptide (GRP). Biochem Pharmacol 2005; 69:579-593. [PMID: 15670577 DOI: 10.1016/j.bcp.2004.11.003] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2004] [Accepted: 11/08/2004] [Indexed: 11/20/2022]
Abstract
The bombesin (Bn) receptor family includes the gastrin-releasing peptide (GRPR) and neuromedin B (NMBR) receptors, Bn receptor subtype 3 (BRS-3) and Bn receptor subtype 4 (BB(4)). They share 50% homology, yet their affinities for gastrin-releasing peptide (GRP) differ. The determinants of GRP high affinity for GRPR and BB(4), and low affinity for BRS-3 are largely unknown. To address this question we made an analysis of structural homologies in Bn receptor members correlated with their affinities for GRP to develop criteria to identify amino acids important for GRP selectivity. Fourteen differences were identified and each was mutated singly in GRPR to that found in hBRS-3. Eleven mutants had a loss of GRP affinity. Furthermore, three of four amino acids in the GRPR selected used a similar approach and previously reported to be important for high affinity Bn binding, were important for GRP affinity. Some GRPR mutants containing combinations of these mutations had greater decreases in GRP affinity than any single mutation. Particularly important for GRP selectivity were K101, Q121, A198, P199, S293, R288, T297 in GRPR. These results were confirmed by making the reverse mutations in BRS-3 to make GRP gain of affinity mutants. Modeling studies demonstrated a number of the important amino acids had side-chains oriented inward and within 6A of the binding pocket. These results demonstrated this approach could identify amino acids needed for GRP affinity and complemented results from chimera/mutagenesis studies by identifying which differences in the extracellular domains of Bn receptors were important for GRP affinity.
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Affiliation(s)
- Tomoo Nakagawa
- Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), National Institutes of Health, Bethesda, MD 20892-1804, USA
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Kamichi S, Wada E, Aoki S, Sekiguchi M, Kimura I, Wada K. Immunohistochemical localization of gastrin-releasing peptide receptor in the mouse brain. Brain Res 2005; 1032:162-70. [PMID: 15680955 DOI: 10.1016/j.brainres.2004.10.068] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/12/2004] [Indexed: 11/23/2022]
Abstract
Gastrin-releasing peptide (GRP) is a mammalian bombesin (BN)-like peptide that binds with high affinity to the GRP receptor (GRP-R). Previous behavioral studies using mice and rats showed that the GRP/GRP-R system mediates learning and memory by modulating neurotransmitter release in the local GABAergic network of the amygdala and the nucleus tractus solitarius (NTS). To date, the precise distribution of GRP-R in the brain has not been elucidated. We used a synthetic peptide derived from mouse GRP-R to generate affinity-purified antibodies to GRP-R and used immunohistochemistry to determine the distribution of GRP-R in the mouse brain. The specificity of anti-GRP-R antibody was confirmed in vitro using COS-7 cells transiently expressing GRP-R and in vivo using GRP-R-deficient and wild-type mouse brain sections. GRP-R immunoreactivity was widely distributed in the isocortex, hippocampal formation, piriform cortex, amygdala, hypothalamus, and brain stem. In particular, GRP-R immunoreactivity was observed in the lateral (LA), central, and basolateral amygdaloid (BLA) nuclei and NTS, which are important regions for memory performance. Double-labeling immunohistochemistry demonstrated that subpopulations of GRP-R are present in GABAergic neurons in the amygdala. Consequently, GRP-R immunoreactivity was observed in the GABAergic neurons of the limbic region. These anatomical results provide support for the idea that the GRP/GRP-R system mediates memory performance by modulating neurotransmitter release in the local GABAergic network.
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Affiliation(s)
- Sari Kamichi
- Department of Cell Biology, School of Human Sciences, Waseda University, 2-579-15, Mikajima, Tokorozawa, Saitama 359-1192, Japan
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Grider JR. Gastrin-releasing peptide is a modulatory neurotransmitter of the descending phase of the peristaltic reflex. Am J Physiol Gastrointest Liver Physiol 2004; 287:G1109-15. [PMID: 15297260 DOI: 10.1152/ajpgi.00080.2004] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The physiological role of gastrin-releasing peptide (GRP) and of its cognate receptors in regulating the intestinal peristaltic reflex was examined in a three-compartment flat-sheet preparation of rat colon. Mucosal stimulation applied to the central compartment at high, but not low levels of intensity, induced GRP release in the caudad compartment where descending relaxation was measured, but not into the ascending compartment where ascending contraction was measured or into the central compartment where the stimuli were applied. The selective GRP (BB(2)) receptor antagonist, [D-Phe(6),des-Met(14)]bombesin(6-14), inhibited descending relaxation and VIP release in the caudad compartment induced by high but not by low levels of stimulation applied to the mucosa in the central compartment. The selective neuromedin B (BB(1)) receptor antagonist, BIM-23127, had no effect on descending relaxation or VIP release. Neither the BB(1) nor the BB(2) antagonist had any effect on ascending contraction or substance P release in the orad compartment. Consistent with the effects of the antagonists on the peristaltic reflex, the BB(2) antagonist but not the BB(1) antagonist decreased the velocity of propulsion of artificial fecal pellets through isolated segments of guinea pig distal colon. The results indicate that GRP is selectively released from myenteric neurons in descending pathways during the peristaltic reflex and that it acts via BB(2) receptors to augment the descending phase of the peristaltic reflex and propulsion.
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Affiliation(s)
- John R Grider
- Department of Physiology, Medical College of Virginia, Virginia Commonwealth University, Richmond, VA 23298, USA.
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ter Beek WP, Muller ESM, Van Hogezand RA, Biemond I, Lamers CBHW. Gastrin releasing peptide receptor expression is decreased in patients with Crohn's disease but not in ulcerative colitis. J Clin Pathol 2004; 57:1047-51. [PMID: 15452158 PMCID: PMC1770439 DOI: 10.1136/jcp.2003.014993] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
BACKGROUND Gastrin releasing peptide (GRP) and neuromedin B are bombesin (BN)-like peptides involved in regulating motility and inflammation in the gastrointestinal tract, which may be useful in treating inflammatory bowel disease (IBD). Three bombesin-like peptide receptors have been reported, but no studies have investigated their localisation in normal and inflamed human intestine. AIM To localise and characterise BN receptors in normal intestine and to see whether this is modified in IBD. METHODS Full thickness intestinal tissue samples were collected from 13 patients with Crohn's disease (CD), 11 with ulcerative colitis (UC), and 19 controls. BN receptor expression was characterised and quantified with storage phosphor autoradiography using BN, GRP, neuromedin B, and the synthetic analogue BN(6-14) as ligands. RESULTS Only BN receptor type 2 (high affinity for GRP) was present in intestinal tissue. Minimal BN binding was detected in the mucosa. In normal colonic smooth muscle, mean BN binding was 336 fmol/g tissue in longitudinal muscle, including the myenteric plexus, and 71 fmol/g in circular muscle. In CD, colonic smooth muscle BN binding was significantly decreased (longitudinal muscle, 106; circular muscle, 19 fmol/g), in contrast to UC (377 and 62 fmol/g, respectively). In CD, a small (not significant) decrease was seen in ileal muscle compared with controls (111 v 169 and 18 v 32 fmol/g tissue for longitudinal and circular muscle, respectively). CONCLUSIONS Only the GRP receptor is expressed in human intestine; expression is highest in longitudinal muscle and myenteric plexus of the colon. Expression is decreased in inflamed and non-inflamed colon of CD, but not in UC.
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Affiliation(s)
- W P ter Beek
- Department of Gastroenterology-Hepatology, Leiden University Medical Centre, 2300 RC Leiden, The Netherlands
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Smith CJ, Volkert WA, Hoffman TJ. Gastrin releasing peptide (GRP) receptor targeted radiopharmaceuticals: a concise update. Nucl Med Biol 2004; 30:861-8. [PMID: 14698790 DOI: 10.1016/s0969-8051(03)00116-1] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
The gastrin releasing peptide (GRP) receptor is becoming an increasingly attractive target for development of new radiolabeled peptides with diagnostic and therapeutic potential. The attractiveness of the GRP receptor as a target is based upon the functional expression of GRP receptors in several tumors of neuroendocrine origin including prostate, breast, and small cell lung cancer. This concise review outlines some of the efforts currently underway to develop new GRP receptor specific radiopharmaceuticals by employing a variety of radiometal chelation systems.
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Affiliation(s)
- C J Smith
- Radiopharmaceutical Sciences Institute, University of Missouri, Columbia, MO 65211, USA
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Nakamichi Y, Wada E, Aoki K, Ohara-Imaizumi M, Kikuta T, Nishiwaki C, Matsushima S, Watanabe T, Wada K, Nagamatsu S. Functions of pancreatic β cells and adipocytes in bombesin receptor subtype-3-deficient mice. Biochem Biophys Res Commun 2004; 318:698-703. [PMID: 15144894 DOI: 10.1016/j.bbrc.2004.04.081] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2004] [Indexed: 11/20/2022]
Abstract
We previously reported that mice lacking bombesin receptor subtype-3 (BRS-3) exhibit mild late-onset obesity and glucose intolerance [Nature 390 (1997) 160]. To examine the mechanism by which glucose intolerance is developed in these mice, we studied insulin release and proinsulin biosynthesis in isolated pancreatic islets and glucose uptake and facilitative glucose transporter (GLUT)-4 translocation in adipose tissues. Although islet insulin contents and the size and number of islets of Langerhans in BRS-3-deficient mice decreased, there was no difference in glucose-stimulated insulin release and proinsulin biosynthesis between BRS-3-deficient and wild-type control mice. In contrast, adipose tissues exhibited a marked difference: the uptake of [(14)C]2-deoxy-D-glucose by adipocytes isolated from BRS-3-deficient mice was not stimulated by 10(-7)M insulin addition, and membrane fractionation analysis showed that GLUT4 was barely detected in the fraction of plasma membrane in BRS-3-deficient mice in the presence of 10(-7)M insulin. Quantitative reverse transcription-PCR (RT-PCR) showed that mRNA levels of GLUT4, insulin receptor, insulin receptor substrate (IRS)-1 and IRS-2, syntaxin 4, SNAP23, and VAMP-2 in adipose tissues of BRS-3-deficient mice were unchanged compared with those in wild-type control mice. We concluded that impaired glucose metabolism observed in BRS-3-deficient mice was mainly caused by impaired GLUT4 translocation in adipocytes.
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Affiliation(s)
- Yoko Nakamichi
- Department of Biochemistry (II), Kyorin University School of Medicine, Shinkawa 6-20-2, Mitaka, Tokyo 181-8611, Japan
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Makarenkova VP, Shurin GV, Tourkova IL, Balkir L, Pirtskhalaishvili G, Perez L, Gerein V, Siegfried JM, Shurin MR. Lung cancer-derived bombesin-like peptides down-regulate the generation and function of human dendritic cells. J Neuroimmunol 2004; 145:55-67. [PMID: 14644031 DOI: 10.1016/j.jneuroim.2003.09.009] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Development of tumors is regulated by tumor-derived neuroendocrine factors, including bombesin-like peptides (BLP). We have evaluated neuroendocrine regulation of dendritic cell (DC) maturation and function by both tumor-derived and purified bombesin (BOM), neuromedin B (NMB), gastrin-releasing peptide (GRP), and a BOM antagonist D-Phe-bombesin (DPB). BOM, NMB and GRP dose-dependently inhibited maturation of DC assessed as down-regulation of CD40, CD80 and CD86 expression on DC. BOM and GRP also inhibited interleukin-12 (IL-12) production by DC and their ability to activate T cells. DPB partly abrogated immunosuppressive effect of tumor cells on DC. These data are a first evidence for the role of BLP in the regulation of DC maturation and function, demonstrating that BLP inhibit DC maturation and longevity in the lung cancer microenvironment. This suggests a new mechanism of tumor escape and provides new targets for the immunopharmacological correction of immune effectors in cancer.
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Affiliation(s)
- Valeria P Makarenkova
- Department of Pathology, University of Pittsburgh Medical Center and University of Pittsburgh Cancer Institute, Pittsburgh, PA 15213, USA
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Moody TW, Merali Z. Bombesin-like peptides and associated receptors within the brain: distribution and behavioral implications. Peptides 2004; 25:511-20. [PMID: 15134870 DOI: 10.1016/j.peptides.2004.02.012] [Citation(s) in RCA: 85] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
As we commemorate the 25th anniversary of the journal Peptides, it is timely to review the functional significance of the bombesin (BB)-like peptides and receptors in the CNS. Over two decades ago we published an article in the journal Peptides demonstrating that BB-like peptides are present in high densities in certain rat brain regions (such as the paraventricular nucleus of the hypothalamus). Subsequently, one of the mammalian forms of BB, gastrin-releasing peptide (GRP) containing cell bodies were found in the suprachiasmatic nucleus of the hypothalamus and nucleus of the solitary tract of the hindbrain. Another related peptide, namely neuromedin (NM)B, was detected in the olfactory bulb and dentate gyrus. BB and GRP bind with high affinity to BB(2) receptors, whereas NMB binds with high affinity to BB(1) receptors. The actions of BB or GRP are blocked by BB(2) receptor antagonists such as (Psi(13,14)-Leu(14))BB whereas PD168368 is a BB(1) receptor antagonist. Exogenous administration of BB into the rat brain causes hypothermia, hyperglycemia, grooming and satiety. BB-like peptides activate the sympathetic nervous system and appear to modulate stress, fear and anxiety responses. GRP and NMB modulate distinct biological processes through discrete brain regions or circuits, and globally these peptidergic systems may serve in an integrative or homeostatic function.
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Affiliation(s)
- Terry W Moody
- CCR, National Cancer Institute Office of the Director, National Institutes of Health, Department of Health and Human Services, Room 3A34, Building 31, 31 Center Drive, Bethesda, MD 20892, USA.
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Maekawa F, Quah HMA, Tanaka K, Ohki-Hamazaki H. Leptin resistance and enhancement of feeding facilitation by melanin-concentrating hormone in mice lacking bombesin receptor subtype-3. Diabetes 2004; 53:570-6. [PMID: 14988239 DOI: 10.2337/diabetes.53.3.570] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Mice lacking either bombesin receptor subtype (BRS)-3 or gastrin-releasing peptide receptor (GRP-R) exhibit feeding abnormalities. However, it is unclear how these receptors are associated with feeding regulation. In BRS-3-deficient mice, we found hyperphagia, subsequent hyperleptinemia, and brain leptin resistance that occurred after the onset of obesity. To explore the cause of this phenomenon, we examined changes in feeding responses to appetite-related neuropeptides in BRS-3-deficient, GRP-R-deficient, and wild-type littermate mice. Among orexigenic neuropeptides, the hyperphagic response to melanin-concentrating hormone (MCH) was significantly enhanced in BRS-3-deficient mice but not in GRP-R-deficient mice. In addition, the levels of MCH-R and prepro-MCH mRNAs in the hypothalamus of BRS-3-deficient mice were significantly more elevated than those of wild-type littermates. There was no significant difference in feeding between BRS-3-deficient and wild-type littermate mice after treatment with bombesin (BN), although the hypophagic response to low-dose BN was significantly suppressed in the GRP-R-deficient mice. These results suggest that upregulation of MCH-R and MCH triggers hyperphagia in BRS-3-deficient mice. From these results, we assume that the BRS-3 gene deletion upsets the mechanism by which leptin decreases the expression of MCH-R and that this effect may be mediated through neural networks independent of BN-related peptides such as GRP-R.
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Affiliation(s)
- Fumihiko Maekawa
- Laboratory of Molecular Neuroscience, School of Biomedical Science and Medical Research Institute, Tokyo Medical and Dental University, Bunkyo-ku, Tokyo, Japan
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