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Zhao H, Cheng Y, Kalra A, Ma K, Zheng Y, Ziman B, Tressler C, Glunde K, Shin EJ, Ngamruengphong S, Khashab M, Singh V, Anders RA, Jit S, Wyhs N, Chen W, Li X, Lin DC, Meltzer SJ. Generation and multiomic profiling of a TP53/CDKN2A double-knockout gastroesophageal junction organoid model. Sci Transl Med 2022; 14:eabq6146. [PMID: 36449602 PMCID: PMC10026384 DOI: 10.1126/scitranslmed.abq6146] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
Inactivation of the tumor suppressor genes tumor protein p53 (TP53) and cyclin-dependent kinase inhibitor 2A (CDKN2A) occurs early during gastroesophageal junction (GEJ) tumorigenesis. However, because of a paucity of GEJ-specific disease models, cancer-promoting consequences of TP53 and CDKN2A inactivation at the GEJ have not been characterized. Here, we report the development of a wild-type primary human GEJ organoid model and a CRISPR-edited transformed GEJ organoid model. CRISPR-Cas9-mediated TP53 and CDKN2A knockout (TP53/CDKN2AKO) in GEJ organoids induced morphologic dysplasia and proneoplastic features in vitro and tumor formation in vivo. Lipidomic profiling identified several platelet-activating factors (PTAFs) among the most up-regulated lipids in CRISPR-edited organoids. PTAF/PTAF receptor (PTAFR) abrogation by siRNA knockdown or a pharmacologic inhibitor (WEB2086) reduced proliferation and other proneoplastic features of TP53/CDKN2AKO GEJ organoids in vitro and tumor formation in vivo. In addition, murine xenografts of Eso26, an established human esophageal adenocarcinoma cell line, were suppressed by WEB2086. Mechanistically, TP53/CDKN2A dual inactivation disrupted both the transcriptome and the DNA methylome, likely mediated by key transcription factors, particularly forkhead box M1 (FOXM1). FOXM1 activated PTAFR transcription by binding to the PTAFR promoter, further amplifying the PTAF-PTAFR pathway. Together, these studies established a robust model system for investigating early GEJ neoplastic events, identified crucial metabolic and epigenomic changes occurring during GEJ model tumorigenesis, and revealed a potential cancer therapeutic strategy. This work provides insights into proneoplastic mechanisms associated with TP53/CDKN2A inactivation in early GEJ neoplasia, which may facilitate early diagnosis and prevention of GEJ neoplasms.
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Affiliation(s)
- Hua Zhao
- Center for Craniofacial Molecular Biology, Herman Ostrow School of Dentistry, and Norris Comprehensive Cancer Center, University of Southern California, Los Angeles, CA 90033, USA
- Division of Gastroenterology and Hepatology, Department of Medicine and Oncology, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
- Clinical Laboratory, The First Affiliated Hospital of Xi’an Jiaotong University, No. 277 Yanta West Road, Xi’an 710061, Shaanxi, China
| | - Yulan Cheng
- Division of Gastroenterology and Hepatology, Department of Medicine and Oncology, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | - Andrew Kalra
- Division of Gastroenterology and Hepatology, Department of Medicine and Oncology, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | - Ke Ma
- Division of Gastroenterology and Hepatology, Department of Medicine and Oncology, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
- Einstein Healthcare Network, Philadelphia, PA 19136, USA
| | - Yueyuan Zheng
- Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA
| | - Benjamin Ziman
- Center for Craniofacial Molecular Biology, Herman Ostrow School of Dentistry, and Norris Comprehensive Cancer Center, University of Southern California, Los Angeles, CA 90033, USA
| | - Caitlin Tressler
- Russell H. Morgan Department of Radiology and Radiological Science, Division of Cancer Imaging Research, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | - Kristine Glunde
- Russell H. Morgan Department of Radiology and Radiological Science, Division of Cancer Imaging Research, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
- The Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | - Eun Ji Shin
- Division of Gastroenterology and Hepatology, Department of Medicine and Oncology, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | - Saowanee Ngamruengphong
- Division of Gastroenterology and Hepatology, Department of Medicine and Oncology, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | - Mouen Khashab
- Division of Gastroenterology and Hepatology, Department of Medicine and Oncology, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | - Vikesh Singh
- Division of Gastroenterology and Hepatology, Department of Medicine and Oncology, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | - Robert A. Anders
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | - Simran Jit
- Division of Gastroenterology and Hepatology, Department of Medicine and Oncology, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | - Nicolas Wyhs
- The Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | - Wei Chen
- Clinical Laboratory, The First Affiliated Hospital of Xi’an Jiaotong University, No. 277 Yanta West Road, Xi’an 710061, Shaanxi, China
| | - Xu Li
- Center for Translational Medicine, The First Affiliated Hospital of Xi’an Jiaotong University, Xi’an 710061, Shaanxi, China
| | - De-Chen Lin
- Center for Craniofacial Molecular Biology, Herman Ostrow School of Dentistry, and Norris Comprehensive Cancer Center, University of Southern California, Los Angeles, CA 90033, USA
| | - Stephen J. Meltzer
- Division of Gastroenterology and Hepatology, Department of Medicine and Oncology, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
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Liu J, Tang H, Xu C, Zhou S, Zhu X, Li Y, Prézeau L, Xu T, Pin JP, Rondard P, Ji W, Liu J. Biased signaling due to oligomerization of the G protein-coupled platelet-activating factor receptor. Nat Commun 2022; 13:6365. [PMID: 36289206 PMCID: PMC9606269 DOI: 10.1038/s41467-022-34056-4] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Accepted: 10/11/2022] [Indexed: 12/25/2022] Open
Abstract
G protein-coupled receptors (GPCRs) are important drug targets that mediate various signaling pathways by activating G proteins and engaging β-arrestin proteins. Despite its importance for the development of therapeutics with fewer side effects, the underlying mechanism that controls the balance between these signaling modes of GPCRs remains largely unclear. Here, we show that assembly into dimers and oligomers can largely influence the signaling mode of the platelet-activating factor receptor (PAFR). Single-particle analysis results show that PAFR can form oligomers at low densities through two possible dimer interfaces. Stabilization of PAFR oligomers through cross-linking increases G protein activity, and decreases β-arrestin recruitment and agonist-induced internalization significantly. Reciprocally, β-arrestin prevents PAFR oligomerization. Our results highlight a mechanism involved in the control of receptor signaling, and thereby provide important insights into the relationship between GPCR oligomerization and downstream signaling.
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Affiliation(s)
- Junke Liu
- grid.33199.310000 0004 0368 7223Cellular Signaling laboratory, International Research Center for Sensory Biology and Technology of MOST, Key Laboratory of Molecular Biophysics of MOE, College of Life Science and Technology, Huazhong University of Science and Technology, 430074 Wuhan, Hubei China ,grid.121334.60000 0001 2097 0141Institut de Génomique Fonctionnelle, Université de Montpellier, CNRS, INSERM, 34094 Montpellier, Cedex France
| | - Hengmin Tang
- grid.33199.310000 0004 0368 7223Cellular Signaling laboratory, International Research Center for Sensory Biology and Technology of MOST, Key Laboratory of Molecular Biophysics of MOE, College of Life Science and Technology, Huazhong University of Science and Technology, 430074 Wuhan, Hubei China
| | - Chanjuan Xu
- grid.33199.310000 0004 0368 7223Cellular Signaling laboratory, International Research Center for Sensory Biology and Technology of MOST, Key Laboratory of Molecular Biophysics of MOE, College of Life Science and Technology, Huazhong University of Science and Technology, 430074 Wuhan, Hubei China
| | - Shengnan Zhou
- grid.33199.310000 0004 0368 7223Cellular Signaling laboratory, International Research Center for Sensory Biology and Technology of MOST, Key Laboratory of Molecular Biophysics of MOE, College of Life Science and Technology, Huazhong University of Science and Technology, 430074 Wuhan, Hubei China
| | - Xunying Zhu
- grid.33199.310000 0004 0368 7223Cellular Signaling laboratory, International Research Center for Sensory Biology and Technology of MOST, Key Laboratory of Molecular Biophysics of MOE, College of Life Science and Technology, Huazhong University of Science and Technology, 430074 Wuhan, Hubei China
| | - Yuanyuan Li
- grid.9227.e0000000119573309National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Laurent Prézeau
- grid.121334.60000 0001 2097 0141Institut de Génomique Fonctionnelle, Université de Montpellier, CNRS, INSERM, 34094 Montpellier, Cedex France
| | - Tao Xu
- grid.9227.e0000000119573309National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China ,grid.9227.e0000000119573309Guangzhou Regenerative Medicine and Health Guangdong Laboratory, Chinese Academy of Sciences, 510005 Guangzhou, China
| | - Jean-Philippe Pin
- grid.121334.60000 0001 2097 0141Institut de Génomique Fonctionnelle, Université de Montpellier, CNRS, INSERM, 34094 Montpellier, Cedex France
| | - Philippe Rondard
- grid.121334.60000 0001 2097 0141Institut de Génomique Fonctionnelle, Université de Montpellier, CNRS, INSERM, 34094 Montpellier, Cedex France
| | - Wei Ji
- grid.9227.e0000000119573309National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China ,grid.9227.e0000000119573309Guangzhou Regenerative Medicine and Health Guangdong Laboratory, Chinese Academy of Sciences, 510005 Guangzhou, China
| | - Jianfeng Liu
- grid.33199.310000 0004 0368 7223Cellular Signaling laboratory, International Research Center for Sensory Biology and Technology of MOST, Key Laboratory of Molecular Biophysics of MOE, College of Life Science and Technology, Huazhong University of Science and Technology, 430074 Wuhan, Hubei China ,grid.9227.e0000000119573309Guangzhou Regenerative Medicine and Health Guangdong Laboratory, Chinese Academy of Sciences, 510005 Guangzhou, China
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Xu J, Zang Y, Cao S, Lei D, Pan X. Aberrant expression of PAFAH1B3 associates with poor prognosis and affects proliferation and aggressiveness in hypopharyngeal squamous cell carcinoma. Onco Targets Ther 2019; 12:2799-2808. [PMID: 31043794 PMCID: PMC6469483 DOI: 10.2147/ott.s196324] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Background Hypopharyngeal squamous cell carcinoma (HSCC) is among the most lethal tumors encountered in the head and neck, and currently lacks satisfactory therapeutic targets. Platelet activating factor acetylhydrolase 1B3 (PAFAH1B3), a cancer-relevant metabolic driver, is reported to play a critical role in controlling tumorigenesis and aggressiveness in several types of cancers. However, the role of PAFAH1B3 in HSCC progression has not yet been identified. Methods The expression pattern of PAFAH1B3 was examined using immunohistochemistry in 83 HSCC tumor tissues and 44 paired adjacent non-tumor samples. Univariate and multivariate analyses were conducted to explore its association with prognosis of HSCC. In vitro loss-of-function assays were performed to explore the impact of PAFAH1B3 knockdown on the biological phenotype of the human HSCC cell line, ie, FaDu cells. Results PAFAH1B3 was overly expressed in the HSCC tumor tissues compared with the adjacent non-tumor samples. Moreover, high expression of PAFAH1B3 was positively correlated with cervical lymph node metastasis. PAFAH1B3 overexpression was associated with poor outcome in HSCC, but it was not an independent prognostic indicator. Furthermore, in vitro loss-of function experiments demonstrated that PAFAH1B3 knockdown suppressed cell proliferation by inducing apoptosis and disrupting cell cycle process, and the migratory and invasive capacities were also attenuated in the absence of PAFAH1B3. Conclusion This study for the first time demonstrated the clinical value and the role of PAFAH1B3 in the biological function of HSCC. This work suggested that PAFAH1B3 might serve as a potential therapeutic target for HSCC patients.
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Affiliation(s)
- Jianing Xu
- Department of Otorhinolaryngology, Qilu Hospital, Shandong University, Jinan, Shandong 250012, People's Republic of China, .,NHC Key Laboratory of Otorhinolaryngology, Shandong University, Jinan, Shandong 250012, People's Republic of China,
| | - Yuanwei Zang
- Department of Urology, Qilu Hospital, Shandong University, Jinan, Shandong 250012, China
| | - Shengda Cao
- Department of Otorhinolaryngology, Qilu Hospital, Shandong University, Jinan, Shandong 250012, People's Republic of China, .,NHC Key Laboratory of Otorhinolaryngology, Shandong University, Jinan, Shandong 250012, People's Republic of China,
| | - Dapeng Lei
- Department of Otorhinolaryngology, Qilu Hospital, Shandong University, Jinan, Shandong 250012, People's Republic of China, .,NHC Key Laboratory of Otorhinolaryngology, Shandong University, Jinan, Shandong 250012, People's Republic of China,
| | - Xinliang Pan
- Department of Otorhinolaryngology, Qilu Hospital, Shandong University, Jinan, Shandong 250012, People's Republic of China, .,NHC Key Laboratory of Otorhinolaryngology, Shandong University, Jinan, Shandong 250012, People's Republic of China,
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Lordan R, Tsoupras A, Zabetakis I. The Potential Role of Dietary Platelet-Activating Factor Inhibitors in Cancer Prevention and Treatment. Adv Nutr 2019; 10:148-164. [PMID: 30721934 PMCID: PMC6370273 DOI: 10.1093/advances/nmy090] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Revised: 09/11/2018] [Accepted: 10/10/2018] [Indexed: 12/11/2022] Open
Abstract
Cancer is the second leading cause of mortality worldwide. The role of unresolved inflammation in cancer progression and metastasis is well established. Platelet-activating factor (PAF) is a key proinflammatory mediator in the initiation and progression of cancer. Evidence suggests that PAF is integral to suppression of the immune system and promotion of metastasis and tumor growth by altering local angiogenic and cytokine networks. Interactions between PAF and its receptor may have a role in various digestive, skin, and hormone-dependent cancers. Diet plays a critical role in the prevention of cancer and its treatment. Research indicates that the Mediterranean diet may reduce the incidence of several cancers in which dietary PAF inhibitors have a role. Dietary PAF inhibitors such as polar lipids have demonstrated inhibitory effects against the physiological actions of PAF in cancer and other chronic inflammatory conditions in vitro and in vivo. In addition, experimental models of radiotherapy and chemotherapy demonstrate that inhibition of PAF as adjuvant therapy may lead to more favorable outcomes. Although promising, there is limited evidence on the potential benefits of dietary PAF inhibitors on cancer prevention or treatment. Therefore, further extensive research is required to assess the effects of various dietary factors and PAF inhibitors and to elucidate the mechanisms in prevention of cancer progression and metastasis at a molecular level.
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Affiliation(s)
- Ronan Lordan
- Department of Biological Sciences, University of Limerick, Limerick, Ireland
| | - Alexandros Tsoupras
- Department of Biological Sciences, University of Limerick, Limerick, Ireland
| | - Ioannis Zabetakis
- Department of Biological Sciences, University of Limerick, Limerick, Ireland
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5
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Duan RD. Alkaline sphingomyelinase (NPP7) in hepatobiliary diseases: A field that needs to be closely studied. World J Hepatol 2018; 10:246-253. [PMID: 29527260 PMCID: PMC5838443 DOI: 10.4254/wjh.v10.i2.246] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2017] [Revised: 01/13/2018] [Accepted: 01/24/2018] [Indexed: 02/06/2023] Open
Abstract
Alkaline sphingomyelinase cleaves phosphocholine from sphingomyelin, platelet-activating factor, lysophosphatidylcholine, and less effectively phosphatidylcholine. The enzyme shares no structure similarities with acid or neutral sphingomyelinase but belongs to ecto-nucleotide pyrophosphatase/phosphodiesterase (NPP) family and therefore is also called NPP7 nowadays. The enzyme is expressed in the intestinal mucosa in many species and additionally in human liver. The enzyme in the intestinal tract has been extensively studied but not that in human liver. Studies on intestinal alkaline sphingomyelinase show that it inhibits colonic tumorigenesis and inflammation, hydrolyses dietary sphingomyelin, and stimulates cholesterol absorption. The review aims to summarize the current knowledge on liver alkaline sphingomyelinase in human and strengthen the necessity for close study on this unique human enzyme in hepatobiliary diseases.
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Affiliation(s)
- Rui-Dong Duan
- Gastroenterology and Nutrition Lab, Department of Clinical Sciences, Lund University, Lund S-22184, Sweden
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6
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Yao B, Liu B, Shi L, Li X, Ren C, Cai M, Wang W, Li J, Sun Y, Wu Y, Wen J. PAFR selectively mediates radioresistance and irradiation-induced autophagy suppression in prostate cancer cells. Oncotarget 2017; 8:13846-13854. [PMID: 28099922 PMCID: PMC5355143 DOI: 10.18632/oncotarget.14647] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Accepted: 01/03/2017] [Indexed: 01/12/2023] Open
Abstract
Platelet-activating factor receptor (PAFR) promotes tumorigenesis, angiogenesis and metastasis. Here, we defined the PAFR as a yielding new inhibiting target to selectively enhance the sensitivity of prostate cancer (PCa) cells to radiation. The selective responding to PAFR inhibiter may be caused by the differential expression pattern of PAFR in PCa cells. In this study, we also determined PAFR as a molecular basis by which the radiation induces autophagy suppression independent of activating mTOR pathway. PAFR can bind to the autophagy-indispensable protein Beclin 1, leading to the disability in its serine phosphorylation. The PAFR antagonist Ginkgolide B (GB) can sensitize radiotherapy by disrupting the formation of PAFR/Beclin 1 complex in PC3 and LNCaP cells, which have elevated PAFR expression after radiation exposure. Most importantly, GB efficiently radiosensitized PC3 and LNCaP tumor xenografts in vivo, and significantly reduced tumor burden. Overall, our results elucidated a significant role of GB in selectively improving the outcomes of PCa receiving radiation therapy.
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Affiliation(s)
- Bing Yao
- Department of Urology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Bingqian Liu
- Department of Urology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Lei Shi
- Department of Urology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Xiang Li
- Department of Plastic Surgery, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Chuanchuan Ren
- Department of Urology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Mingbo Cai
- Department of Gynaecology and Obstetrics, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Wen Wang
- Department of Gynaecology and Obstetrics, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Jianhua Li
- Department of Urology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Yongde Sun
- Department of Urology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Yudong Wu
- Department of Urology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Jianguo Wen
- Department of Urology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
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Chen J, Lan T, Zhang W, Dong L, Kang N, Zhang S, Fu M, Liu B, Liu K, Zhan Q. Feed-Forward Reciprocal Activation of PAFR and STAT3 Regulates Epithelial-Mesenchymal Transition in Non-Small Cell Lung Cancer. Cancer Res 2015; 75:4198-210. [PMID: 26359459 DOI: 10.1158/0008-5472.can-15-1062] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2015] [Accepted: 07/29/2015] [Indexed: 11/16/2022]
Abstract
Platelet-activating factor receptor (PAFR), a G-protein-coupled receptor, has been implicated in tumorigenesis, but its contributions to metastatic progression have not been investigated. Here, we show that PAFR is overexpressed in non-small cell lung cancer (NSCLC) as well as in breast, colorectal, and gastric carcinomas. Expression of PAFR correlates closely with clinical stages, survival time, and distant metastasis. In human NSCLC cells, activation of the PAF/PAFR signaling axis accentuated malignant character, including by stimulating epithelial-mesenchymal transition (EMT). In contrast, silencing PAFR in aggressive NSCLC cells inhibited these effects. Mechanistic investigations showed that PAFR stimulated EMT by activating STAT3 via upregulation of G-protein-dependent SRC or JAK2 kinase activity. Notably, STAT3 transcriptionally elevated PAFR expression. Thus, activation of PAFR in NSCLC cells initiated a forward feedback loop responsible for mediating the aggressive malignant character of NSCLC cells in vitro and in vivo. Reinforcing this reciprocal activation loop, PAF/PAFR signaling also upregulated IL6 expression and thereby STAT3 activation. Overall, our results elucidated an important role for PAFR dysregulation in the pathogenicity of NSCLC and unraveled a forward feedback loop between PAFR and STAT3 that acts to drive the malignant progression of NSCLC.
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Affiliation(s)
- Jie Chen
- State Key Laboratory of Molecular Oncology, Cancer Institute and Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Tian Lan
- State Key Laboratory of Molecular Oncology, Cancer Institute and Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China. Department of Neurosurgery, Beijing Sanbo Brain Hospital; Capital Medical University, Beijing, China
| | - Weimin Zhang
- State Key Laboratory of Molecular Oncology, Cancer Institute and Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Lijia Dong
- State Key Laboratory of Molecular Oncology, Cancer Institute and Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Nan Kang
- State Key Laboratory of Molecular Oncology, Cancer Institute and Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Shumin Zhang
- State Key Laboratory of Molecular Oncology, Cancer Institute and Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Ming Fu
- State Key Laboratory of Molecular Oncology, Cancer Institute and Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Bing Liu
- Department of Pharmacology, School of Pharmacy, Guangdong Pharmaceutical University, Guangzhou, China
| | - Kangtai Liu
- National Key Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Peking Union Medical College, Tsinghua University and Chinese Academy of Medical Sciences, Beijing, China
| | - Qimin Zhan
- State Key Laboratory of Molecular Oncology, Cancer Institute and Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.
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Damiani E, Puebla-Osorio N, Gorbea E, Ullrich SE. Platelet-Activating Factor Induces Epigenetic Modifications in Human Mast Cells. J Invest Dermatol 2015; 135:3034-3040. [PMID: 26316070 PMCID: PMC4648694 DOI: 10.1038/jid.2015.336] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2015] [Revised: 07/27/2015] [Accepted: 08/11/2015] [Indexed: 12/29/2022]
Abstract
Ultraviolet (UV) radiation-induced systemic immune suppression is a major risk factor for skin cancer induction. The migration of dermal mast cells from the skin to the draining lymph nodes plays a prominent role in activating systemic immune suppression. UV-induced keratinocyte-derived platelet-activating factor (PAF) activates mast cell migration, in part by up regulating the expression of CXCR4 on the surface of mast cells. Others have indicated that epigenetic mechanisms regulate CXCR4 expression, so we asked whether PAF activates epigenetic mechanisms in mast cells. Human mast cells were treated with PAF and the effect on DNA methylation and/or acetylation was measured. PAF suppressed the expression of DNA methyltransferase (DNMT) 1 and 3b. On the other hand, PAF increased p300 histone acetyltransferase expression, and the acetylation of histone H3, which coincided with a decreased expression of the histone deacetylase HDAC2. Chromatin immunoprecipitation assays indicated that PAF-treatment activated the acetylation of the CXCR4 promoter. Finally, inhibiting histone acetylation blocked p300 up-regulation and suppressed PAF-induced surface expression of CXCR4. Our findings suggest a novel molecular mechanism for PAF, activation of epigenetic modifications. We suggest that PAF may serve as an endogenous molecular mediator that links the environment (UV radiation) with the epigenome.
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Affiliation(s)
- Elisabetta Damiani
- Dipartimento di Scienze delle Vita e dell'Ambiente, Università Politecnica delle Marche, Ancona, Italy.,Department of Immunology and The Center for Cancer Immunology Research, The University of Texas, MD Anderson Cancer Center, Houston, Texas, 77030, USA
| | - Nahum Puebla-Osorio
- Department of Immunology and The Center for Cancer Immunology Research, The University of Texas, MD Anderson Cancer Center, Houston, Texas, 77030, USA
| | - Enrique Gorbea
- Department of Immunology and The Center for Cancer Immunology Research, The University of Texas, MD Anderson Cancer Center, Houston, Texas, 77030, USA
| | - Stephen E Ullrich
- Department of Immunology and The Center for Cancer Immunology Research, The University of Texas, MD Anderson Cancer Center, Houston, Texas, 77030, USA.,The Graduate School for Biomedical Sciences, Houston, Texas, 77030, USA
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9
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Identification of Differential Protein Expression in Hepatocellular Carcinoma Induced Wistar Albino Rats by 2D Electrophoresis and MALDI-TOF-MS Analysis. Indian J Clin Biochem 2015; 31:194-202. [PMID: 27069327 DOI: 10.1007/s12291-015-0510-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2015] [Accepted: 05/13/2015] [Indexed: 12/12/2022]
Abstract
Hepato cellular carcinoma (HCC) is a type of malignant tumor. To investigate the proteins in cancer molecular mechanism and its role in HCC, we have used proteomic tools such as 2DE and MALDI-TOF-MS. Our investigation ravels that, plasma α-fetoprotein and carcinoembryonic antigen levels were elevated in DEN induced rats and gradually decreased after the treatment with 1,3BPMU. 2DE and MALDI-TOF-MS tool offers to identify the up and down regulation of proteins in HCC. Proteomic study reveals that, five differentially expressed proteins were identified in DEN induced rats and 1,3BPMU treated rats i.e. three up regulated protein such as T kininogen, NDPKB, PRMT1 (DEN induced rats), RGS19 and PAF (1,3BPMU treated rats) in 3BPMU treated rats, activation of transcription of a single gene from multiple promoters provides flexibility in the controlled gene expression. The regulations of hepatocyte stimulating factor were slow down the proliferation of hepatic cell and uncontrolled hepatic cell growth and also molecular signals strongly argue for a patho-physiological role in liver metastasis to control the cell aggression. This indicates that, anti cancer property of 1,3BPMU can be used as potent anti cancer agent. The present study also shows the proteomic approach helps to elucidate the tumor maker as well as regulatory marker proteins in HCC.
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Platelet-activating factor induces cell cycle arrest and disrupts the DNA damage response in mast cells. Cell Death Dis 2015; 6:e1745. [PMID: 25950475 PMCID: PMC4669695 DOI: 10.1038/cddis.2015.115] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Revised: 03/16/2015] [Accepted: 03/17/2015] [Indexed: 12/17/2022]
Abstract
Platelet-activating factor (PAF) is a potent phospholipid modulator of inflammation that has diverse physiological and pathological functions. Previously, we demonstrated that PAF has an essential role in ultraviolet (UV)-induced immunosuppression and reduces the repair of damaged DNA, suggesting that UV-induced PAF is contributing to skin cancer initiation by inducing immune suppression and also affecting a proper DNA damage response. The exact role of PAF in modulating cell proliferation, differentiation or transformation is unclear. Here, we investigated the mechanism(s) by which PAF affects the cell cycle and impairs early DNA damage response. PAF arrests proliferation in transformed and nontransformed human mast cells by reducing the expression of cyclin-B1 and promoting the expression of p21. PAF-treated cells show a dose-dependent cell cycle arrest mainly at G2–M, and a decrease in the DNA damage response elements MCPH1/BRIT-1 and ataxia telangiectasia and rad related (ATR). In addition, PAF disrupts the localization of p-ataxia telangiectasia mutated (p-ATM), and phosphorylated-ataxia telangiectasia and rad related (p-ATR) at the site of DNA damage. Whereas the potent effect on cell cycle arrest may imply a tumor suppressor activity for PAF, the impairment of proper DNA damage response might implicate PAF as a tumor promoter. The outcome of these diverse effects may be dependent on specific cues in the microenvironment.
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Kispert S, Marentette J, McHowat J. Cigarette smoke induces cell motility via platelet-activating factor accumulation in breast cancer cells: a potential mechanism for metastatic disease. Physiol Rep 2015; 3:3/3/e12318. [PMID: 25802360 PMCID: PMC4393154 DOI: 10.14814/phy2.12318] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Most cancer deaths are a result of metastasis rather than the primary tumor. Although cigarette smoking has been determined as a risk factor for several cancers, its role in metastasis has not been studied in detail. We propose that cigarette smoking contributes to metastatic disease via inhibition of breast cancer cell platelet-activating factor acetylhydrolase (PAF-AH), resulting in PAF accumulation and a subsequent increase in cell motility. We studied several breast cell lines, including immortalized mammary epithelial cells (MCF-10A), luminal A hormone positive MCF-7, basal-like triple negative MDA-MB-468, and claudin-low triple-negative highly metastatic MDA-MB-231 breast tumor cells. We exposed cells to cigarette smoke extract (CSE) for up to 48 h. CSE inhibited PAF-AH activity, increased PAF accumulation, and increased cell motility in MDA-MB-231 metastatic triple negative breast cancer cells. The calcium-independent phospholipase A2 (iPLA2) inhibitor, (S) bromoenol lactone ((S)-BEL) was used to prevent the accumulation of PAF and further prevented the increase in cell motility seen previously when cells were exposed to CSE. Thus, iPLA2 or PAF may represent a therapeutic target to manage metastatic disease, particularly in triple-negative breast cancer patients who smoke.
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Affiliation(s)
- Shannon Kispert
- Department of Pathology, Saint Louis University School of Medicine, St. Louis, Missouri
| | - John Marentette
- Department of Pathology, Saint Louis University School of Medicine, St. Louis, Missouri
| | - Jane McHowat
- Department of Pathology, Saint Louis University School of Medicine, St. Louis, Missouri
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Valli A, Rodriguez M, Moutsianas L, Fischer R, Fedele V, Huang HL, Van Stiphout R, Jones D, Mccarthy M, Vinaxia M, Igarashi K, Sato M, Soga T, Buffa F, Mccullagh J, Yanes O, Harris A, Kessler B. Hypoxia induces a lipogenic cancer cell phenotype via HIF1α-dependent and -independent pathways. Oncotarget 2015; 6:1920-41. [PMID: 25605240 PMCID: PMC4385826 DOI: 10.18632/oncotarget.3058] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2014] [Accepted: 12/10/2014] [Indexed: 01/11/2023] Open
Abstract
The biochemistry of cancer cells diverges significantly from normal cells as a result of a comprehensive reprogramming of metabolic pathways. A major factor influencing cancer metabolism is hypoxia, which is mediated by HIF1α and HIF2α. HIF1α represents one of the principal regulators of metabolism and energetic balance in cancer cells through its regulation of glycolysis, glycogen synthesis, Krebs cycle and the pentose phosphate shunt. However, less is known about the role of HIF1α in modulating lipid metabolism. Lipids serve cancer cells to provide molecules acting as oncogenic signals, energetic reserve, precursors for new membrane synthesis and to balance redox biological reactions. To study the role of HIF1α in these processes, we used HCT116 colorectal cancer cells expressing endogenous HIF1α and cells in which the hif1α gene was deleted to characterize HIF1α-dependent and independent effects on hypoxia regulated lipid metabolites. Untargeted metabolomics integrated with proteomics revealed that hypoxia induced many changes in lipids metabolites. Enzymatic steps in fatty acid synthesis and the Kennedy pathway were modified in a HIF1α-dependent fashion. Palmitate, stearate, PLD3 and PAFC16 were regulated in a HIF-independent manner. Our results demonstrate the impact of hypoxia on lipid metabolites, of which a distinct subset is regulated by HIF1α.
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Affiliation(s)
- Alessandro Valli
- Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
- Target Discovery Institute, Nuffield Department of Medicine, University of Oxford, Oxford, UK
- Mass Spectrometry Research Facility CRL, Department of Chemistry, University of Oxford, Oxford, UK
| | - Miguel Rodriguez
- Centre for Omic Sciences, Rovira i Virgili University, Reus, Spain
- Biomedical Research Centre in Diabetes and Associated Metabolic Disorders, Madrid, Spain
| | - Loukas Moutsianas
- The Wellcome Trust Centre for Human Genetics, Nuffield Department of Medicine, Oxford, UK
| | - Roman Fischer
- Target Discovery Institute, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Vita Fedele
- Target Discovery Institute, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Hong-Lei Huang
- Target Discovery Institute, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Ruud Van Stiphout
- Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
| | - Dylan Jones
- Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
| | - Michael Mccarthy
- Target Discovery Institute, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Maria Vinaxia
- Centre for Omic Sciences, Rovira i Virgili University, Reus, Spain
- Biomedical Research Centre in Diabetes and Associated Metabolic Disorders, Madrid, Spain
| | - Kaori Igarashi
- Institute for Advanced Biosciences, Keio University, Tsuruoka, Yamagata, Japan
| | - Maya Sato
- Institute for Advanced Biosciences, Keio University, Tsuruoka, Yamagata, Japan
| | - Tomoyoshi Soga
- Institute for Advanced Biosciences, Keio University, Tsuruoka, Yamagata, Japan
| | - Francesca Buffa
- Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
| | - James Mccullagh
- Mass Spectrometry Research Facility CRL, Department of Chemistry, University of Oxford, Oxford, UK
| | - Oscar Yanes
- Centre for Omic Sciences, Rovira i Virgili University, Reus, Spain
- Biomedical Research Centre in Diabetes and Associated Metabolic Disorders, Madrid, Spain
| | - Adrian Harris
- Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
| | - Benedikt Kessler
- Target Discovery Institute, Nuffield Department of Medicine, University of Oxford, Oxford, UK
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Xu C, Reichert EC, Nakano T, Lohse M, Gardner AA, Revelo MP, Topham MK, Stafforini DM. Deficiency of phospholipase A2 group 7 decreases intestinal polyposis and colon tumorigenesis in Apc(Min/+) mice. Cancer Res 2013; 73:2806-16. [PMID: 23361301 DOI: 10.1158/0008-5472.can-12-2374] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Platelet-activating factor (PAF) is a naturally occurring phospholipid that mediates diverse effects such as physiological and pathological inflammation, immunosuppression, and cancer. Several lines of evidence support both positive and negative roles for PAF in carcinogenesis. PAF stimulates cell growth, oncogenic transformation, and metastasis, but can also limit proliferation and induce apoptosis. The biological context and microenvironment seem to define whether PAF has pro- or anticarcinogenic effects. To investigate the role of exacerbated PAF signaling in colon cancer, we conducted cell-based and in vivo studies using genetically engineered mice lacking expression of phospholipase A2 group 7 (PLA2G7), an enzyme that specifically metabolizes PAF and structurally related glycerophospholipids. Absence of Pla2g7 robustly decreased intestinal polyposis and colon tumor formation in Apc(Min)(/+) mice, suggesting an antitumorigenic role for PAF in settings characterized by aberrant function of the tumor suppressor Adenomatous polyposis coli (Apc). In colonic epithelial cells, exposure to a PAF analog led to dephosphorylation of Akt at serine-473 and induction of apoptosis. The mechanism of this response involved formation of a complex between β-arrestin 1 and the Akt phosphatase PHLPP2, and activation of the intrinsic pathway of apoptosis. Our results suggest that strategies based on inhibiting PLA2G7 activity or increasing PAF-mediated signaling hold promise for the treatment of intestinal malignancies that harbor mutations in APC.
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Affiliation(s)
- Changxin Xu
- Huntsman Cancer Institute, University of Utah, Salt Lake City, Utah, USA
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14
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Emerging roles for phospholipase A2 enzymes in cancer. Biochimie 2010; 92:601-10. [DOI: 10.1016/j.biochi.2010.03.019] [Citation(s) in RCA: 116] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2009] [Accepted: 03/24/2010] [Indexed: 12/24/2022]
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15
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Fletcher JI, Haber M, Henderson MJ, Norris MD. ABC transporters in cancer: more than just drug efflux pumps. Nat Rev Cancer 2010; 10:147-56. [PMID: 20075923 DOI: 10.1038/nrc2789] [Citation(s) in RCA: 790] [Impact Index Per Article: 52.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Multidrug transporter proteins are best known for their contributions to chemoresistance through the efflux of anticancer drugs from cancer cells. However, a considerable body of evidence also points to their importance in cancer extending beyond drug transport to fundamental roles in tumour biology. Currently, much of the evidence for these additional roles is correlative and definitive studies are needed to confirm causality. We propose that delineating the precise roles of these transporters in tumorigenesis and treatment response will be important for the development of more effective targeted therapies.
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Affiliation(s)
- Jamie I Fletcher
- Children's Cancer Institute Australia for Medical Research, Lowry Cancer Research Centre, University of New South Wales, P.O. BOX 151, Randwick NSW 2031, Australia
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16
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Aponte M, Jiang W, Lakkis M, Li MJ, Edwards D, Albitar L, Vitonis A, Mok SC, Cramer DW, Ye B. Activation of platelet-activating factor receptor and pleiotropic effects on tyrosine phospho-EGFR/Src/FAK/paxillin in ovarian cancer. Cancer Res 2008; 68:5839-48. [PMID: 18632638 DOI: 10.1158/0008-5472.can-07-5771] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Among the proinflammatory mediators, platelet-activating factor (PAF, 1-O-alkyl-2-acetyl-sn-glycero-3-phosphorylcholine) is a major primary and secondary messenger involved in intracellular and extracellular communication. Evidence suggests that PAF plays a significant role in oncogenic transformation, tumor growth, angiogenesis, and metastasis. However, PAF, with its receptor (PAFR) and their downstream signaling targets, has not been thoroughly studied in cancer. Here, we characterized the PAFR expression pattern in 4 normal human ovarian surface epithelial (HOSE) cell lines, 13 ovarian cancer cell lines, paraffin blocks (n = 84), and tissue microarrays (n = 230) from patients with ovarian cancer. Overexpression of PAFR was found in most nonmucinous types of ovarian cancer but not in HOSE and mucinous cancer cells. Correspondingly, PAF significantly induced cell proliferation and invasion only in PAFR-positive cells (i.e., OVCA429 and OVCA432), but not in PAFR-negative ovarian cells (HOSE and mucinous RMUG-L). The dependency of cell proliferation and invasion on PAFR was further confirmed using PAFR-specific small interfering RNA gene silencing probes, antibodies against PAFR and PAFR antagonist, ginkgolide B. Using quantitative multiplex phospho-antibody array technology, we found that tyrosine phosphorylation of EGFR/Src/FAK/paxillin was coordinately activated by PAF treatment, which was correlated with the activation of phosphatidylinositol 3-kinase and cyclin D1 as markers for cell proliferation, as well as matrix metalloproteinase 2 and 9 for invasion. Specific tyrosine Src inhibitor (PP2) reversibly blocked PAF-activated cancer cell proliferation and invasion. We suggest that PAFR is an essential upstream target of Src and other signal pathways to control the PAF-mediated cancer progression.
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Affiliation(s)
- Margarita Aponte
- Laboratory of Gynecologic Oncology and Epidemiology, Department of Obstetrics and Gynecology and Reproductive Biology, Brigham and Women's Hospital, Dana-Farber Cancer Center, Harvard Medical School, Boston, Massachusetts 02115, USA
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Melnikova V, Bar-Eli M. Inflammation and melanoma growth and metastasis: the role of platelet-activating factor (PAF) and its receptor. Cancer Metastasis Rev 2008; 26:359-71. [PMID: 17721743 DOI: 10.1007/s10555-007-9092-9] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
An inflammatory tumor microenvironment fosters tumor growth, angiogenesis and metastatic progression. Platelet-activating factor (PAF) is an inflammatory biolipid produced from membrane glycerophospholipids. Through the activity of its G-protein coupled receptor, PAF triggers a variety of pathological reactions including tumor neo-angiogenesis. Several groups have demonstrated that inhibiting PAF-PAF receptor pathway at the level of a ligand or receptor results in an effective inhibition of experimental tumor growth and metastasis. In particular, our group has recently demonstrated that PAF receptor antagonists can effectively inhibit the metastatic potential of human melanoma cells in nude mice. Furthermore, we showed that PAF stimulated the phosphorylation of CREB and ATF-1 in metastatic melanoma cells, which resulted in overexpression of MMP-2 and MT1-MMP. Our data indicate that PAF acts as a promoter of melanoma metastasis in vivo. Since only metastatic melanoma cells overexpress CREB/ATF-1, we propose that these cells are better equipped to respond to PAF within the tumor microenvironment when compared to their non-metastatic counterparts.
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Affiliation(s)
- Vladislava Melnikova
- Department of Cancer Biology, The University of Texas M. D. Anderson Cancer Center, P.O. Box 173, Houston, TX 77030, USA
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Cheng Y, Wu J, Hertervig E, Lindgren S, Duan D, Nilsson A, Duan RD. Identification of aberrant forms of alkaline sphingomyelinase (NPP7) associated with human liver tumorigenesis. Br J Cancer 2007; 97:1441-8. [PMID: 17923876 PMCID: PMC2360232 DOI: 10.1038/sj.bjc.6604013] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Alkaline sphingomyelinase (alk-SMase) is expressed in the intestine and human liver. It may inhibit colonic tumorigenesis, and loss of function mutations have been identified in human colon cancer. The present study investigates its expression in human liver cancer. In HepG2 liver cancer cells, RT–PCR identified three transcripts with 1.4, 1.2 and 0.4 kb, respectively. The 1.4 kb form is the wild-type cDNA with five translated exons, the 1.2 kb product lacks exon 4 and the 0.4 kb form is a combination of exons 1 and 5. Genomic sequence showed that these aberrant transcripts were products of alternative splicing. Transient expression of the 1.2 kb form showed no alk-SMase activity. In HepG2 cells, the alk-SMase activity is low in monolayer condition and increased with cell polarisation. Coexistence of 1.4 and 1.2 kb forms was also identified in one hepatoma biopsy. GenBank search identified a cDNA clone from human liver tumour, which codes a protein containing full length of alk-SMase plus a 73-amino-acid tag at the N terminus. The aberrant form was translated by an alternative starting codon upstream of the wild-type mRNA. Expression study showed that linking the tag markedly reduced the enzyme activity. We also analysed human liver biopsy samples and found relatively low alk-SMase activity in diseases with increased risk of liver tumorigenesis. In conclusion, expression of alk-SMase is changed in hepatic tumorigenesis, resulting in loss or marked reduction of the enzyme function.
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Affiliation(s)
- Y Cheng
- Gastroenterology Lab, Biomedical Centre, B11, Institute of Clinical Sciences, Lund University, Lund S-221 84, Sweden
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19
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Ko HM, Kang JH, Jung B, Kim HA, Park SJ, Kim KJ, Kang YR, Lee HK, Im SY. Critical role for matrix metalloproteinase-9 in platelet-activating factor-induced experimental tumor metastasis. Int J Cancer 2007; 120:1277-83. [PMID: 17187368 DOI: 10.1002/ijc.22450] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
In this study, the roles of matrix metalloproteinase (MMP)-2 and MMP-9 in platelet-activating factor (PAF)-induced experimental pulmonary metastasis of the murine melanoma cell, B16F10, were investigated. An injection of PAF resulted in increases in mRNA expression, protein levels and the activities of both MMP-2 and MMP-9 in the lungs. The overall expression of MMP-9 was stronger than that of MMP-2. The increased MMP-9 expression was inhibited by both NF-kappaB and AP-1 inhibitors, whereas the increased MMP-2 expression was inhibited by only AP-1 inhibitors. Immunohistochemical analysis revealed that MMP-9 was expressed in bronchial epithelial cells as well as in the walls of blood vessels, whereas MMP-2 expression was observed only in bronchial epithelial cells. PAF significantly enhanced the pulmonary metastasis of B16F10, which was inhibited by both NF-kappaB and c-jun inhibitors. MMP-9 inhibitor, but not that of MMP-2, completely inhibited PAF-induced B16F10 metastasis. These data indicate that MMP-9, the expression of which was regulated by NF-kappaB and AP-1, plays a critical role in PAF-induced enhancement of pulmonary melanoma metastasis.
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Affiliation(s)
- Hyun-Mi Ko
- Department of Biological Sciences, College of Natural Sciences, Chonnam National University, Kwangju 500-757, Republic of Korea
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Denizot Y, De Armas R, Caire F, Pommepuy I, Truffinet V, Labrousse F. Platelet-activating factor and human meningiomas. Neuropathol Appl Neurobiol 2006; 32:674-8. [PMID: 17083481 DOI: 10.1111/j.1365-2990.2006.00775.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Meningiomas are common primary intracranial tumours. Platelet-activating factor (PAF) is an inflammatory and angiogenic lipid mediator involved in several types of cancer. The presence of PAF receptor (PAF-R) transcripts, the levels of PAF, the phospholipase A2 activity (PLA2, the enzymatic activity implicated in PAF formation) and the PAF acetylhydrolase activity (AHA, the PAF degrading enzyme) were investigated in 49 human meningiomas. PAF-R transcripts, PAF, PLA2 and AHA were detected in meningiomas. However, their levels did not correlate with biological parameters such as the tumour grade, the presence of associated oedema, necrosis, mitotic index as well as intensity of the neovascularization and chronic inflammatory response. In conclusion, PAF is present in meningiomas where it might act on tumour growth by altering the local angiogenic and/or cytokine networks as previously suggested for human breast and colorectal cancer.
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Mathonnet M, Descottes B, Valleix D, Truffinet V, Labrousse F, Denizot Y. Platelet-activating factor in cirrhotic liver and hepatocellular carcinoma. World J Gastroenterol 2006; 12:2773-8. [PMID: 16718768 PMCID: PMC4130990 DOI: 10.3748/wjg.v12.i17.2773] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [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: Platelet-activating factor (PAF) is a pro-inflammatory and angiogenic lipid mediator. Here we aimed to investigate levels of PAF, lyso-PAF (the PAF precursor), phospholipase A2 (PLA2, the enzymatic activity generating lyso-PAF), acetylhydrolase activity (AHA, the PAF degrading enzyme) and PAF receptor (PAF-R) transcripts in cirrhotic liver and hepatocellular carcinoma (HCC).
METHODS: Twenty-nine patients with HCC were enrolled in this study. Cirrhosis was present in fourteen patients and seven had no liver disease. Tissue PAF levels were investigated by a platelet-aggregation assay. Lyso-PAF was assessed after its chemical acetylation into PAF. AHA was determined by degradation of [3H]-PAF. PLA2 levels were assessed by EIA. PAF-R transcripts were investigated using RT-PCR.
RESULTS: Elevated amounts of PAF and PAF-R transcripts 1 (leukocyte-type) were found in cirrhotic tissues as compared with non-cirrhotic ones. Higher amounts of PAF and PAF-R transcripts 1 and 2 (tissue-type) were found in HCC tissues as compared with non-tumor tissues. PLA2, lyso-PAF and AHA levels were not changed in cirrhotic tissues and HCC.
CONCLUSION: While the role of PAF is currently unknown in liver physiology, this study suggests its potential involvement in the inflammatory network found in the cirrhotic liver and in the angiogenic response during HCC.
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Affiliation(s)
- Muriel Mathonnet
- Service de Chirurgie Digestive, Endcrinienne et Générale, CHU Dupuytren, 2 avenue Luther King, 87042 Limoges, France
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Wu J, Nilsson Å, Jönsson B, Stenstad H, Agace W, Cheng Y, Duan RD. Intestinal alkaline sphingomyelinase hydrolyses and inactivates platelet-activating factor by a phospholipase C activity. Biochem J 2006; 394:299-308. [PMID: 16255717 PMCID: PMC1386028 DOI: 10.1042/bj20051121] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Alkaline sphingomyelinase (alk-SMase) is a new member of the NPP (nucleotide pyrophosphatase/phosphodiesterase) family that hydrolyses SM (sphingomyelin) to generate ceramide in the intestinal tract. The enzyme may protect the intestinal mucosa from inflammation and tumorigenesis. PAF (platelet-activating factor) is a pro-inflammatory phospholipid involved in pathogenesis of inflammatory bowel diseases. We examined whether alk-SMase can hydrolyse and inactivate PAF. [3H]Octadecyl-labelled PAF was incubated with purified rat intestinal alk-SMase or recombinant human alk-SMase expressed in COS-7 cells. The hydrolytic products were assayed with TLC and MS. We found that alkSMase cleaved the phosphocholine head group from PAF and generated 1-O-alkyl-2-acetyl-sn-glycerol. Differing from the activity against SM, the activity against PAF was optimal at pH 7.5, inhibited by EDTA and stimulated by 0.1-0.25 mM Zn2+. The activity was abolished by site mutation of the predicted metal-binding sites that are conserved in all NPP members. Similar to the activity against SM, the activity against PAF was dependent on bile salt, particularly taurocholate and taurochenodeoxycholate. The V(max) for PAF hydrolysis was 374 mumol x h(-1) x (mg of protein)(-1). The hydrolysis of PAF and SM could be inhibited by the presence of SM and PAF respectively, the inhibition of PAF hydrolysis by SM being stronger. The PAF-induced MAPK (mitogen-activated protein kinase) activation and IL-8 (interleukin 8) release in HT-29 cells, and chemotaxis in leucocytes were abolished by alk-SMase treatment. In conclusion, alk-SMase hydrolyses and inactivates PAF by a phospholipase C activity. The finding reveals a novel function, by which alk-SMase may counteract the development of intestinal inflammation and colon cancer.
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Affiliation(s)
- Jun Wu
- *Gastroenterology Laboratory, Biomedical Centre, B11, Lund University, S-221 84 Lund, Sweden
| | - Åke Nilsson
- *Gastroenterology Laboratory, Biomedical Centre, B11, Lund University, S-221 84 Lund, Sweden
| | - Bo A. G. Jönsson
- †Department of Occupational and Environment Medicine, Institute of Laboratory Medicine, University Hospital, S-221 85 Lund, Sweden
| | - Hanna Stenstad
- ‡Immunology Unit, Lund University, S-221 84 Lund, Sweden
| | - William Agace
- ‡Immunology Unit, Lund University, S-221 84 Lund, Sweden
| | - Yajun Cheng
- *Gastroenterology Laboratory, Biomedical Centre, B11, Lund University, S-221 84 Lund, Sweden
| | - Rui-Dong Duan
- *Gastroenterology Laboratory, Biomedical Centre, B11, Lund University, S-221 84 Lund, Sweden
- To whom correspondence should be addressed (email )
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Mathonnet M, Descottes B, Valleix D, Labrousse F, Denizot Y. VEGF in hepatocellular carcinoma and surrounding cirrhotic liver tissues. World J Gastroenterol 2006; 12:830-1. [PMID: 16521208 PMCID: PMC4066145 DOI: 10.3748/wjg.v12.i5.830] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
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Denizot Y, Chianéa T, Labrousse F, Truffinet V, Delage M, Mathonnet M. Platelet-activating factor and human thyroid cancer. Eur J Endocrinol 2005; 153:31-40. [PMID: 15994743 DOI: 10.1530/eje.1.01947] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
OBJECTIVE Platelet-activating factor (PAF) is a pro-inflammatory and angiogenic lipid mediator involved in several types of cancer in humans. The levels of PAF, lyso-PAF (the PAF precursor), phospholipase A2 activity (PLA2, the enzymatic activity implicated in lyso-PAF formation) and acetylhydrolase activity (AHA, the PAF-degrading enzyme) were investigated in various diseased thyroid tissues. SUBJECTS Control and diseased tissue of patients with a hyperplastic goitre (n = 14), a benign adenoma (n = 12) and a papillary thyroid carcinoma (n = 15) were investigated. RESULTS PAF receptor transcripts were found in the human thyroid tissue. PAF, lyso-PAF, PLA2 and AHA were present in control thyroid tissues, their levels being significantly correlated with each other, suggesting tiny regulations of the PAF metabolic pathways inside the thyroid gland. PAF, lyso-PAF, PLA2 and AHA levels remained unchanged in diseased tissues of patients with a hyperplastic goitre, a benign adenoma and a papillary thyroid carcinoma. No difference was found between PAF, lyso-PAF, PLA2 and AHA levels with respect to the TNM tumour status and the histological sub-type of papillary thyroid carcinoma. No correlation was found between tissue PAF levels and those of vascular endothelial growth factor and basic fibroblast growth factor, two angiogenic growth factors involved in thyroid cancer and that mediate their effect through PAF release in breast and colorectal cancer. CONCLUSION PAF, PAF receptor transcripts and the enzymatic activities implicated in PAF production and degradation are present in the thyroid gland. While the physiological role of PAF is presently unknown in thyroid physiology, this study highlights no evidence for a potentially important role of PAF during human thyroid cancer, a result that markedly differs from breast and colorectal ones.
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Affiliation(s)
- Yves Denizot
- UMR CNRS 6101, Faculté de Médecine, Limoges, France.
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