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Lee MK, Woo SR, Noh JK, Bae M, Lee Y, Min S, Kong M, Lee YC, Ko SG, Eun YG. Prognostic value of FLOT1-related gene signature in head and neck squamous cell carcinoma: insights into radioresistance mechanisms and clinical outcomes. Cell Death Discov 2025; 11:224. [PMID: 40335491 PMCID: PMC12058980 DOI: 10.1038/s41420-025-02500-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2024] [Revised: 04/15/2025] [Accepted: 04/17/2025] [Indexed: 05/09/2025] Open
Abstract
We aimed to develop and validate the ability of a FLOT1-related gene signature to predict survival in head and neck squamous cell carcinoma (HNSCC) patients and to explore FLOT1's role in modulating the responses to radiation therapy (RT). Using TCGA dataset, we identified a gene expression signature reflective of FLOT1 and applied LASSO regression to build a prediction model. Patients were stratified into high- and low-risk subgroups based on this signature. The prognostic value was confirmed across three independent cohorts, showing that high-risk patients had significantly poorer overall survival. Cox proportional hazards models were used to establish this gene signature as an independent prognostic factor for overall survival in HNSCC patients. Additionally, this signature predicted survival outcomes in patients undergoing RT. In vitro and in vivo experiments revealed that inhibiting FLOT1 expression increased the radiation sensitivity of HNSCC cells by modulating the phospho-PTEN/IGF1R axis. Moreover, silencing FLOT1 decreased radioresistance in radioresistant cell lines and xenograft mouse models. In conclusion, the FLOT1-related gene signature is a strong prognostic marker for HNSCC and may help identify patients who may benefit from RT.
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Affiliation(s)
- Min Kyeong Lee
- Department of Biomedical Science and Technology, Graduate School, Kyung Hee University, Seoul, Republic of Korea
| | - Seon Rang Woo
- Department of Otolaryngology-Head and Neck Surgery, Kyung Hee University School of Medicine, Kyung Hee University Medical Center, Seoul, Republic of Korea
| | - Joo Kyung Noh
- Department of Otolaryngology-Head and Neck Surgery, Kyung Hee University School of Medicine, Kyung Hee University Medical Center, Seoul, Republic of Korea
| | - MinJi Bae
- Department of Biomedical Science and Technology, Graduate School, Kyung Hee University, Seoul, Republic of Korea
| | - YeonSeo Lee
- Department of Biomedical Science and Technology, Graduate School, Kyung Hee University, Seoul, Republic of Korea
| | - Soonki Min
- Department of Radiation Oncology, Kyung Hee University School of Medicine Kyung Hee University Medical Center, Seoul, Republic of Korea
| | - Moonkyoo Kong
- Department of Radiation Oncology, Kyung Hee University School of Medicine Kyung Hee University Medical Center, Seoul, Republic of Korea
| | - Young Chan Lee
- Department of Otolaryngology-Head and Neck Surgery, Kyung Hee University School of Medicine, Kyung Hee University Medical Center, Seoul, Republic of Korea
| | - Seong-Gyu Ko
- Department of Preventive Medicine, College of Korean Medicine, Kyung Hee University, Seoul, Republic of Korea
| | - Young-Gyu Eun
- Department of Biomedical Science and Technology, Graduate School, Kyung Hee University, Seoul, Republic of Korea.
- Department of Otolaryngology-Head and Neck Surgery, Kyung Hee University School of Medicine, Kyung Hee University Medical Center, Seoul, Republic of Korea.
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2
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Mo C, Sterpi M, Jeon H, Bteich F. Resistance to Anti-HER2 Therapies in Gastrointestinal Malignancies. Cancers (Basel) 2024; 16:2854. [PMID: 39199625 PMCID: PMC11352490 DOI: 10.3390/cancers16162854] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2024] [Revised: 08/13/2024] [Accepted: 08/14/2024] [Indexed: 09/01/2024] Open
Abstract
Human epidermal growth factor 2 (HER2) is a tyrosine kinase receptor that interacts with multiple signaling pathways related to cellular growth and proliferation. Overexpression or amplification of HER2 is linked to various malignancies, and there have been decades of research dedicated to targeting HER2. Despite the landmark ToGA trial, progress in HER2-positive gastrointestinal malignancies has been hampered by drug resistance. This review examines current HER2 expression patterns and therapies for gastroesophageal, colorectal, biliary tract, and small bowel cancers, while dissecting potential resistance mechanisms that limit treatment effectiveness.
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Affiliation(s)
- Christiana Mo
- Department of Medical Oncology, Albert Einstein College of Medicine, Bronx, NY 10461, USA; (C.M.); (M.S.); (H.J.)
- Department of Medical Oncology, Montefiore Medical Center, Bronx, NY 10467, USA
| | - Michelle Sterpi
- Department of Medical Oncology, Albert Einstein College of Medicine, Bronx, NY 10461, USA; (C.M.); (M.S.); (H.J.)
- Department of Medical Oncology, Montefiore Medical Center, Bronx, NY 10467, USA
| | - Hyein Jeon
- Department of Medical Oncology, Albert Einstein College of Medicine, Bronx, NY 10461, USA; (C.M.); (M.S.); (H.J.)
- Department of Medical Oncology, Montefiore Medical Center, Bronx, NY 10467, USA
| | - Fernand Bteich
- Department of Medical Oncology, Albert Einstein College of Medicine, Bronx, NY 10461, USA; (C.M.); (M.S.); (H.J.)
- Department of Medical Oncology, Montefiore Medical Center, Bronx, NY 10467, USA
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Liu J, Pan Y, Liu Y, Wei W, Hu X, Xin W, Chen N. The regulation of PTEN: Novel insights into functions as cancer biomarkers and therapeutic targets. J Cell Physiol 2023; 238:1693-1715. [PMID: 37334436 DOI: 10.1002/jcp.31053] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Revised: 05/10/2023] [Accepted: 05/17/2023] [Indexed: 06/20/2023]
Abstract
This review summarizes the implications of the primary tumor suppressor protein phosphatase and tensin homolog (PTEN) in aggressive cancer development. PTEN interacts with other cellular proteins or factors suggesting the existence of an intricate molecular network that regulates their oncogenic function. Accumulating evidence has shown that PTEN exists and plays a role in the cytoplasmic organelles and in the nucleus. PTEN blocks phosphoinositide 3-kinases (PI3K)-protein kinase B-mammalian target of rapamycin signaling pathway by dephosphorylating phosphatidylinositol (PI)-3,4,5-triphosphate to PI-4,5-bisphosphate thus counteracting PI3K function. Studies have shown that PTEN expression is tightly regulated at transcriptional, posttranscriptional, and posttranslational levels (including protein-protein interactions and posttranslational modifications). Despite recent advances in PTEN research, the regulation and function of the PTEN gene remain largely unknown. How mutation or loss of specific exons in the PTEN gene occurs and involves in cancer development is not clear. This review illustrates the regulatory mechanisms of PTEN expression and discusses how PTEN participates in tumor development and/or suppression. Future prospects for the clinical applications are also highlighted.
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Affiliation(s)
- Jie Liu
- Department of Dermatology, Skin Research, Peking University Shenzhen Hospital, Shenzhen, Guangdong, China
| | - Yongli Pan
- Department of Neurology, University Medical Center Göttingen, Göttingen, Germany
| | - Yuheng Liu
- Department of Neurology, University Medical Center Göttingen, Göttingen, Germany
| | - Wei Wei
- Department of Neurology, University Medical Center Göttingen, Göttingen, Germany
| | - Xiaoping Hu
- Department of Dermatology, Skin Research, Peking University Shenzhen Hospital, Shenzhen, Guangdong, China
| | - Wenqiang Xin
- Department of Neurology, University Medical Center Göttingen, Göttingen, Germany
| | - Nan Chen
- Department of Gastroenterology, Liaocheng People's Hospital, Liaocheng, China
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Aldehyde dehydrogenase 2 regulates autophagy via the Akt-mTOR pathway to mitigate renal ischemia-reperfusion injury in hypothermic machine perfusion. Life Sci 2020; 253:117705. [PMID: 32334008 DOI: 10.1016/j.lfs.2020.117705] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Revised: 04/14/2020] [Accepted: 04/19/2020] [Indexed: 01/15/2023]
Abstract
AIMS Ischemia-reperfusion injury (IRI) is harmful to patients following kidney transplantation. Hypothermic machine perfusion (HMP) can be adopted to preserve grafts and reduce consequential injury. We hypothesized that aldehyde dehydrogenase 2 (ALDH2) partly mitigates kidney IRI via regulating excessive autophagy in HMP. MATERIALS AND METHODS The rabbits were assigned to 5 groups: Normal, HMP, HMP + Alda-1, HMP + CYA and cold storage (CS). After the rabbit autologous kidney transplantation, renal pathology and function were evaluated by histological analysis, glomerular related proteins (desmin, nephrin), tubular injury factors (NGAL, Ki67), serum creatinine (Cr) and blood urea nitrogen (BUN). Oxidative stress molecular Malondialdehyde (MDA) and superoxide dismutase (SOD2) expression, as well as inflammatory cytokines (TNF-α, IL-6, IL-10) were assessed by immunohistochemistry. The expression of LC3, p62, ALDH2, p-Akt, mTOR, PTEN, p-PTEN, and 4-HNE were measured by immunohistochemistry, RT-PCR, Western blot analysis or ELISA. KEY FINDINGS HMP was more effective than CS for kidney preservation, with p- ALDH2 expressed in greater quantities in HMP. The results of kidney pathology and function in HMP + Alda-1 were the best. The MDA & SOD2 and the Vyacheslav score were improved in HMP + CYA. ALDH2 reduced 4-HNE-induced oxidative stress, inflammatory infiltration, the expression of LC3, p62 and inhibited autophagy accompanied by activation of p-Akt and mTOR via p-PTEN/PTEN. SIGNIFICANCE Akt-mTOR autophagy pathway is a novel target for ALDH2 to reduce renal IRI partly by inhibition of 4-HNE in HMP, then protecting the donated kidney received after cardiac death (DCD).
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Levy A, Leynes C, Baig M, Chew SA. The Application of Biomaterials in the Treatment of Platinum‐Resistant Ovarian Cancer. ChemMedChem 2019; 14:1810-1827. [DOI: 10.1002/cmdc.201900450] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Indexed: 12/26/2022]
Affiliation(s)
- Arkene Levy
- Department of Pharmacology, College of Medical Sciences Nova Southeastern University 3200 South University Drive Davie FL 33328 USA
| | - Carolina Leynes
- Department Health and Biomedical Sciences University of Texas Rio Grande Valley One West University Boulevard Brownsville TX 78520 USA
| | - Mirza Baig
- Dr. Kiran C. Patel College of Osteopathic Medicine Nova Southeastern University 3200 South University Drive Davie FL 33328 USA
| | - Sue Anne Chew
- Department Health and Biomedical Sciences University of Texas Rio Grande Valley One West University Boulevard Brownsville TX 78520 USA
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Yan R, Wang Y, Shi M, Xiao Y, Liu L, Liu L, Guo B. Regulation of PTEN/AKT/FAK pathways by PPARγ impacts on fibrosis in diabetic nephropathy. J Cell Biochem 2019; 120:6998-7014. [PMID: 30652342 DOI: 10.1002/jcb.27937] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Accepted: 10/02/2018] [Indexed: 02/06/2023]
Abstract
Renal tubular epithelial-to-mesenchymal transition (EMT) and tubulointerstitial fibrosis (TIF) are important pathological features of diabetic nephropathy (DN). However, the regulatory mechanism underlying EMT and TIF are still unclear. Previous studies showed that the decrease in the expression of phosphatase and tensin homolog deleted on chromosome 10 (PTEN) was closely related to the aggravation of DN, but no published study showed how PTEN participated in the regulation of EMT and TIF. In this study, the rat proximal tubular epithelial cells (NRK52E) and C57BL mice and human kidney tissues were used as the research objects to investigate the mechanism underlying the regulatory effect of peroxisome proliferator-activated receptors γ (PPARγ) on PTEN and its influence on EMT and TIF, the regulation of PTEN's dual activity of lipid phosphatase/protein phosphatase by the serine threonine protein kinase B(AKT)/focal adhesion kinase (FAK) signaling pathway, and the role of PTEN in EMT and TIF. The results showed that PPARγ regulated the expression of PTEN at a transcriptional level and further regulated EMT and TIF. This dual activity could regulate the phosphorylation level of AKT and FAK and also affect FAK transcription. However, the 129 mutant of PTEN (PTEN-G129E) lost the lipid phosphatase activity, and its protein phosphatase activity was involved only in EMT and renal fibrosis through regulating FAK phosphorylation. This study systematically elucidated the role of PPARγ/PTEN/AKT/FAK signaling pathway in EMT and TIF during the pathogenesis of DN.
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Affiliation(s)
- Rui Yan
- Department of Nephrology, Affiliated Hospital of Guizhou Medical University, Guiyang, China
| | - Yuanyuan Wang
- Department of Pathophysiology, Guizhou Medical University, Guiyang, China
| | - Mingjun Shi
- Department of Pathophysiology, Guizhou Medical University, Guiyang, China
| | - Ying Xiao
- Department of Pathophysiology, Guizhou Medical University, Guiyang, China
| | - Lirong Liu
- Department of Clinical Hematology, Affiliated Hospital of Guizhou Medical University, Guiyang, China
| | - Lingling Liu
- Department of Pathophysiology, Guizhou Medical University, Guiyang, China
| | - Bing Guo
- Department of Pathophysiology, Guizhou Medical University, Guiyang, China
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Schumann C, Chan S, Millar JA, Bortnyak Y, Carey K, Fedchyk A, Wong L, Korzun T, Moses AS, Lorenz A, Shea D, Taratula O, Khalimonchuk O, Taratula O. Intraperitoneal nanotherapy for metastatic ovarian cancer based on siRNA-mediated suppression of DJ-1 protein combined with a low dose of cisplatin. NANOMEDICINE-NANOTECHNOLOGY BIOLOGY AND MEDICINE 2018; 14:1395-1405. [PMID: 29635082 DOI: 10.1016/j.nano.2018.03.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Revised: 03/12/2018] [Accepted: 03/20/2018] [Indexed: 12/11/2022]
Abstract
Herein, we report an efficient combinatorial therapy for metastatic ovarian cancer based on siRNA-mediated suppression of DJ-1 protein combined with a low dose of cisplatin. DJ-1 protein modulates, either directly or indirectly, different oncogenic pathways that support and promote survival, growth, and invasion of ovarian cancer cells. To evaluate the potential of this novel therapy, we have engineered a cancer-targeted nanoplatform and validated that DJ-1 siRNA delivered by this nanoplatform after intraperitoneal injection efficiently downregulates the DJ-1 protein in metastatic ovarian cancer tumors and ascites. In vivo experiments revealed that DJ-1 siRNA monotherapy outperformed cisplatin alone by inhibiting tumor growth and increasing survival of mice with metastatic ovarian cancer. Finally, three cycles of siRNA-mediated DJ-1 therapy in combination with a low dose of cisplatin completely eradicated ovarian cancer tumors from the mice, and there was no cancer recurrence detected for the duration of the study, which lasted 35 weeks.
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Affiliation(s)
- Canan Schumann
- Department of Pharmaceutical Sciences, College of Pharmacy, Oregon State University, Portland, OR, USA
| | - Stephanie Chan
- Department of Pharmaceutical Sciences, College of Pharmacy, Oregon State University, Portland, OR, USA
| | - Jess A Millar
- Fairborz Maseeh Department of Mathematics and Statistics, Portland State University, OR, USA
| | - Yuliya Bortnyak
- Department of Pharmaceutical Sciences, College of Pharmacy, Oregon State University, Portland, OR, USA
| | - Katherine Carey
- Department of Pharmaceutical Sciences, College of Pharmacy, Oregon State University, Portland, OR, USA
| | - Alex Fedchyk
- Department of Pharmaceutical Sciences, College of Pharmacy, Oregon State University, Portland, OR, USA
| | - Leon Wong
- Department of Pharmaceutical Sciences, College of Pharmacy, Oregon State University, Portland, OR, USA
| | - Tetiana Korzun
- Department of Pharmaceutical Sciences, College of Pharmacy, Oregon State University, Portland, OR, USA
| | - Abraham S Moses
- Department of Pharmaceutical Sciences, College of Pharmacy, Oregon State University, Portland, OR, USA
| | - Anna Lorenz
- Department of Pharmaceutical Sciences, College of Pharmacy, Oregon State University, Portland, OR, USA
| | - Delany Shea
- Department of Pharmaceutical Sciences, College of Pharmacy, Oregon State University, Portland, OR, USA
| | - Olena Taratula
- Department of Pharmaceutical Sciences, College of Pharmacy, Oregon State University, Portland, OR, USA
| | - Oleh Khalimonchuk
- Department of Biochemistry and Redox Biology Center, University of Nebraska, Lincoln, NE, USA; Fred & Pamela Buffett Cancer Center, Omaha, NE, USA
| | - Oleh Taratula
- Department of Pharmaceutical Sciences, College of Pharmacy, Oregon State University, Portland, OR, USA.
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Yang S, Wang Y, Gao H, Wang B. MicroRNA-30a-3p overexpression improves sepsis-induced cell apoptosis in vitro and in vivo via the PTEN/PI3K/AKT signaling pathway. Exp Ther Med 2018; 15:2081-2087. [PMID: 29434809 PMCID: PMC5776646 DOI: 10.3892/etm.2017.5644] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2017] [Accepted: 08/10/2017] [Indexed: 11/06/2022] Open
Abstract
The aim of the present study was to explain the mechanism of miR-30a-3p overexpression in sepsis-induced cell apoptosis in vitro and in vivo. For the in vitro cell experiments, H9c2 cells were divided into three groups, including the untreated normal control (NC), lipopolysaccharide (LPS)-treated and miRNA (treated with LPS and transfection with miRNA-30a-3p) groups. The cell proliferation and apoptosis were evaluated by MTT assay and flow cytometry, respectively. The relative protein expression levels were measured by western blot assay. In the in vivo experiment, a sepsis rat model was established by intraperitoneal injection of LPS. Sprague Dawley rats were divided into three groups, including the NC, LPS-injected and miRNA (in which model rats were injected with miR-30a-3p vector at the caudal vein) groups. The myocardial morphology in different groups was observed by hematoxylin and eosin staining. In addition, tissue apoptosis and protein expression levels were evaluated by TUNEL and western blot assay, respectively. The results of cell experiments indicated that the cell proliferation rate was significantly increased and the cell apoptosis rate was significantly downregulated in the miR-30a-3p group compared with the LPS group (both P<0.05). The relative protein expression of phosphatase and tensin homolog (PTEN) was markedly decreased in the miRNA group compared with the LPS group, while the levels of phosphoinositide 3-kinase (PI3K) and protein kinase B (AKT) were significantly increased in the miRNA group (all P<0.05). In the in vivo experiments, the myocardial morphology of the miRNA group was improved compared with that of the LPS group. Compared with the LPS group, cell apoptosis in the miRNA group was significantly downregulated (P<0.05), while the relative protein levels (PTEN, PI3K and AKT) in the tissues were also significantly altered (P<0.05). In conclusion, miR-30a-3p overexpression may improve the sepsis-induced cell apoptosis in vitro and in vivo via the PTEN/PI3K/AKT signaling pathway.
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Affiliation(s)
- Shuying Yang
- Intensive Care Unit, Tianjin First Central Hospital, Tianjin 300192, P.R. China
| | - Yongqiang Wang
- Intensive Care Unit, Tianjin First Central Hospital, Tianjin 300192, P.R. China
| | - Hongmei Gao
- Intensive Care Unit, Tianjin First Central Hospital, Tianjin 300192, P.R. China
| | - Bing Wang
- Intensive Care Unit, Tianjin First Central Hospital, Tianjin 300192, P.R. China
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Chung YC, Chen CH, Tsai YT, Lin CC, Chou JC, Kao TY, Huang CC, Cheng CH, Hsu CP. Litchi seed extract inhibits epidermal growth factor receptor signaling and growth of Two Non-small cell lung carcinoma cells. BMC COMPLEMENTARY AND ALTERNATIVE MEDICINE 2017; 17:16. [PMID: 28056952 PMCID: PMC5217642 DOI: 10.1186/s12906-016-1541-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/23/2016] [Accepted: 12/12/2016] [Indexed: 01/20/2023]
Abstract
BACKGROUND Litchi seeds possess rich amounts of phenolics and have been shown to inhibit proliferation of several types of cancer cells. However, the suppression of EGFR signaling in non-small cell lung cancer (NSCLC) by litchi seed extract (LCSE) has not been fully understood. METHODS In this study, the effects of LCSE on EGFR signaling, cell proliferation, the cell cycle and apoptosis in A549 adenocarcinoma cells and NCI- H661 large-cell carcinoma cells were examined. RESULTS The results demonstrated that LCSE potently reduced the number of cancer cells and induced growth inhibition, cell-cycle arrest in the G1 or G2/M phase, and apoptotic death in the cellular experiment. Only low cytotoxicity effect was noted in normal lung MRC-5 cells. LCSE also suppressed cyclins and Bcl-2 and elevated Kip1/p27, Bax and caspase 8, 9 and 3 activities, which are closely associated with the downregulation of EGFR and its downstream Akt and Erk-1/-2 signaling. CONCLUSION The results implied that LCSE suppressed EGFR signaling and inhibited NSCLC cell growth. This study provided in vitro evidence that LCSE could serve as a potential agent for the adjuvant treatment of NSCLC.
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Affiliation(s)
- Yuan-Chiang Chung
- Department of Surgery, Cheng-Ching Hospital, Chung-Kang Branch, Taichung, Taiwan
- Department of Medicinal Botanicals and Health Applications, Da-Yeh University, Changhua, Taiwan
| | - Chin-Hui Chen
- Department of Health and Leisure Management, Yuanpei University of Medical Technology, Hsinchu, Taiwan
| | - Yu-Ting Tsai
- Department of Medical Laboratory Detection, Lotung Poh-Ai Hospital, Yilan, Taiwan
| | - Chih-Cheng Lin
- Department of Biotechnology and Pharmaceutical Technology, Yuanpei University of Medical Technology, Hsinchu, Taiwan
| | - Jyh-Ching Chou
- Department of Natural Resources and Environmental Studies, National Dong Hwa University, Hualien, Taiwan
| | - Ting-Yu Kao
- Department of Medical Laboratory Science and Biotechnology, Yuanpei University of Medical Technology, No. 306 Yuanpei Street, Hsinchu, 30015, Taiwan
| | - Chiu-Chen Huang
- Veterinary Medical Teaching Hospital of National Chung Hsing University, Taichung, Taiwan
| | - Chi-Hsuan Cheng
- Department of Laboratory Medicine, Taipei Medical University Hospital, Taipei, Taiwan
| | - Chih-Ping Hsu
- Department of Medical Laboratory Science and Biotechnology, Yuanpei University of Medical Technology, No. 306 Yuanpei Street, Hsinchu, 30015, Taiwan.
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Schumann C, Chan S, Khalimonchuk O, Khal S, Moskal V, Shah V, Alani AWG, Taratula O, Taratula O. Mechanistic Nanotherapeutic Approach Based on siRNA-Mediated DJ-1 Protein Suppression for Platinum-Resistant Ovarian Cancer. Mol Pharm 2016; 13:2070-83. [PMID: 27170529 DOI: 10.1021/acs.molpharmaceut.6b00205] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We report an efficient therapeutic modality for platinum resistant ovarian cancer based on siRNA-mediated suppression of a multifunctional DJ-1 protein that is responsible for the proliferation, growth, invasion, oxidative stress, and overall survival of various cancers. The developed therapeutic strategy can work alone or in concert with a low dose of the first line chemotherapeutic agent cisplatin, to elicit a maximal therapeutic response. To achieve an efficient DJ-1 knockdown, we constructed the polypropylenimine dendrimer-based nanoplatform targeted to LHRH receptors overexpressed on ovarian cancer cells. The quantitative PCR and Western immunoblotting analysis revealed that the delivered DJ-1 siRNA downregulated the expression of targeted mRNA and corresponding protein by more than 80% in various ovarian cancer cells. It was further demonstrated that siRNA-mediated DJ-1 suppression dramatically impaired proliferation, viability, and migration of the employed ovarian cancer cells. Finally, the combinatorial approach led to the most pronounced therapeutic response in all the studied cell lines, outperforming both siRNA-mediated DJ-1 knockdown and cisplatin treatment alone. It is noteworthy that the platinum-resistant cancer cells (A2780/CDDP) with the highest basal level of DJ-1 protein are most susceptible to the developed therapy and this susceptibility declines with decreasing basal levels of DJ-1. Finally, we interrogate the molecular underpinnings of the DJ-1 knockdown effects in the treatment of the ovarian cancer cells. By using various experimental techniques, it was revealed that DJ-1 depletion (1) decreases the activity of the Akt pathway, thereby reducing cellular proliferation and migration and increasing the antiproliferative effect of cisplatin on ovarian cancer cells; (2) enhances the activity of p53 tumor suppressor protein therefore restoring cell cycle arrest functionality and upregulating the Bax-caspase pathway, triggering cell death; and (3) weakens the cellular defense mechanisms against inherited oxidative stress thereby increasing toxic intracellular radicals and amplifying the reactive oxygen species created by the administration of cisplatin.
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Affiliation(s)
- Canan Schumann
- Department of Pharmaceutical Sciences, College of Pharmacy, Oregon State University , Portland, Oregon 97201, United States
| | - Stephanie Chan
- Department of Pharmaceutical Sciences, College of Pharmacy, Oregon State University , Portland, Oregon 97201, United States
| | - Oleh Khalimonchuk
- Fred & Pamela Buffett Cancer Center, University of Nebraska Medical Center , Omaha, Nebraska 68198, United States
| | - Shannon Khal
- Department of Pharmaceutical Sciences, College of Pharmacy, Oregon State University , Portland, Oregon 97201, United States
| | - Vitaliya Moskal
- Department of Pharmaceutical Sciences, College of Pharmacy, Oregon State University , Portland, Oregon 97201, United States
| | - Vidhi Shah
- Department of Pharmaceutical Sciences, College of Pharmacy, Oregon State University , Portland, Oregon 97201, United States
| | - Adam W G Alani
- Department of Pharmaceutical Sciences, College of Pharmacy, Oregon State University , Portland, Oregon 97201, United States
| | - Olena Taratula
- Department of Pharmaceutical Sciences, College of Pharmacy, Oregon State University , Portland, Oregon 97201, United States
| | - Oleh Taratula
- Department of Pharmaceutical Sciences, College of Pharmacy, Oregon State University , Portland, Oregon 97201, United States
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Ali A, Mehdi SJ, Hajela K, Saluja SS, Mishra PK, Sameer AS, Rizvi MMA. Allelic loss at PTEN locus leads to progression of colorectal carcinoma among North Indian patients. Biomarkers 2016; 21:716-720. [PMID: 27098297 DOI: 10.3109/1354750x.2016.1172115] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
We evaluated the loss of heterozygosity (LOH) at 10q23.3 locus of microsatellite markers; D10S198, D10S192, and D10S541 of PTEN gene in 223 North Indian colorectal cancer (CRC) specimens. DNA was isolated and microsatellite-specific markers polymerase chain reaction was performed. Out of total 223 cases 102 showed LOH for at least one of the locus. In addition, thereto a significant association was found with the clinicopathologic features like grade of differentiation, clinical stage, invasion, lymph node invasion, and the clinical outcome (p < 0.05). These data argue that the given markers to check the possible LOH of PTEN gene at locus 10q23.3 could be considered as one of the diagnostic markers in CRC.
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Affiliation(s)
- Asgar Ali
- a Department of Biochemistry , AIIMS , Patna , India
| | - Syed Jafar Mehdi
- b Department of Biosciences, Genome Biology Lab , Jamia Millia Islamia , New Delhi , India
| | - Krishnan Hajela
- c School of Life Sciences , Devi Ahilya Vishwavidyalaya , Indore , India
| | - Sundeep Singh Saluja
- d Department of Gastrointestinal Surgery , G. B. Pant Hospital , New Delhi , India
| | - Pramod Kumar Mishra
- d Department of Gastrointestinal Surgery , G. B. Pant Hospital , New Delhi , India
| | - Aga Syed Sameer
- e Basic Medical Sciences, College of Medicine-Jeddah, King Saud bin Abdulaziz University for Health Sciences , Riyadh , Saudi Arabia
| | - M Moshahid Alam Rizvi
- b Department of Biosciences, Genome Biology Lab , Jamia Millia Islamia , New Delhi , India
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12
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Huang W, Tian SS, Hang PZ, Sun C, Guo J, Du ZM. Combination of microRNA-21 and microRNA-146a Attenuates Cardiac Dysfunction and Apoptosis During Acute Myocardial Infarction in Mice. MOLECULAR THERAPY. NUCLEIC ACIDS 2016; 5:e296. [PMID: 26978580 PMCID: PMC5014454 DOI: 10.1038/mtna.2016.12] [Citation(s) in RCA: 104] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Accepted: 01/28/2016] [Indexed: 11/28/2022]
Abstract
Recent studies have revealed the cytoprotective roles of microRNAs (miRNAs) miR-21 and miR-146a against ischemic cardiac injuries. While these studies investigated each of these miRNAs as an independent individual factor, our previous study has suggested the possible interaction between these two miRNAs. The present study was designed to investigate this possibility by evaluating the effects of miR-21 and miR-146a combination on cardiac ischemic injuries and the underlying mechanisms. MiR-21 and miR-146a synergistically decreased apoptosis under ischemia/hypoxic conditions in cardiomyocytes compared with either miR-21 or miR-146a alone. Mice coinjected with agomiR-21 and agomiR-146a had decreased infarct size, increased ejection fraction (EF), and fractional shortening (FS). These effects were greater than those induced by either of the two agomiRs. Furthermore, greater decreases in p38 mitogen-associated protein kinase phosphorylation (p-p38 MAPK) were observed with miR-21: miR-146a combination as compared to application of either of the miRNAs. These data suggest that combination of miR-21 and miR-146a has a greater protective effect against cardiac ischemia/hypoxia-induced apoptosis as compared to these miRNAs applied individually. This synergistic action is mediated by enhanced potency of inhibition of cardiomyocyte apoptosis by the miR-21—PTEN/AKT—p-p38—caspase-3 and miR-146a—TRAF6—p-p38—caspase-3 signal pathways.
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Affiliation(s)
- Wei Huang
- Institute of Clinical Pharmacology of the Second Affiliated Hospital, Harbin Medical University, Harbin, China
| | - Shan-Shan Tian
- Institute of Clinical Pharmacology of the Second Affiliated Hospital, Harbin Medical University, Harbin, China
| | - Peng-Zhou Hang
- Institute of Clinical Pharmacology of the Second Affiliated Hospital, Harbin Medical University, Harbin, China
| | - Chuan Sun
- Institute of Clinical Pharmacology of the Second Affiliated Hospital, Harbin Medical University, Harbin, China
| | - Jing Guo
- Institute of Clinical Pharmacology of the Second Affiliated Hospital, Harbin Medical University, Harbin, China
| | - Zhi-Min Du
- Institute of Clinical Pharmacology of the Second Affiliated Hospital, Harbin Medical University, Harbin, China.,The University Key Laboratory of Drug Research, Heilongjiang Province, Harbin, China
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Gao R, Cai C, Gan J, Yang X, Shuang Z, Liu M, Li S, Tang H. miR-1236 down-regulates alpha-fetoprotein, thus causing PTEN accumulation, which inhibits the PI3K/Akt pathway and malignant phenotype in hepatoma cells. Oncotarget 2016; 6:6014-28. [PMID: 25714026 PMCID: PMC4467418 DOI: 10.18632/oncotarget.3338] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2014] [Accepted: 01/14/2015] [Indexed: 12/21/2022] Open
Abstract
Alpha fetoprotein (AFP) is a clinical biomarker of hepatocellular carcinoma (HCC). Here, we found that miR-1236 is down-regulated, whereas AFP is highly expressed in HCC tissues and cells. We demonstrated that miR-1236 directly targets the 3′UTR of AFP and down-regulates its expression. Also, miR-1236 inhibited and AFP stimulated proliferation, migration, invasion and vasculogenic mimicry (VM) of HCC. In agreement, AFP over-expression counteracted the inhibitory effect of miR-1236. We demonstrated that AFP promoted the ubiquitination of PTEN, thus decreasing PTEN levels, while miR-1236 inhibited the PI3K/Akt pathway.
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Affiliation(s)
- Rui Gao
- Tianjin Life Science Research Center and Basic Medical School, Tianjin Medical University, Tianjin, China
| | - Chunli Cai
- Tianjin Life Science Research Center and Basic Medical School, Tianjin Medical University, Tianjin, China
| | - Jiancheng Gan
- Department of Surgery, Secondary Hospital of Tianjin Medical University, Tianjin, China
| | - Xi Yang
- Tianjin Life Science Research Center and Basic Medical School, Tianjin Medical University, Tianjin, China
| | - Zeyu Shuang
- State Key Laboratory of Oncology in Southern China, Department of Hepatobiliary Oncology, Cancer Center, Sun Yat-sen University, Guangzhou, China
| | - Min Liu
- Tianjin Life Science Research Center and Basic Medical School, Tianjin Medical University, Tianjin, China
| | - Shengping Li
- State Key Laboratory of Oncology in Southern China, Department of Hepatobiliary Oncology, Cancer Center, Sun Yat-sen University, Guangzhou, China
| | - Hua Tang
- Tianjin Life Science Research Center and Basic Medical School, Tianjin Medical University, Tianjin, China
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14
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Zhou J, Du T, Li B, Rong Y, Verkhratsky A, Peng L. Crosstalk Between MAPK/ERK and PI3K/AKT Signal Pathways During Brain Ischemia/Reperfusion. ASN Neuro 2015; 7:7/5/1759091415602463. [PMID: 26442853 PMCID: PMC4601130 DOI: 10.1177/1759091415602463] [Citation(s) in RCA: 131] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
The epidermal growth factor receptor (EGFR) is linked to the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) and Raf/mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK1/2) signaling pathways. During brain ischemia/reperfusion, EGFR could be transactivated, which stimulates these intracellular signaling cascades that either protect cells or potentiate cell injury. In the present study, we investigated the activation of EGFR, PI3K/AKT, and Raf/MAPK/ERK1/2 during ischemia or reperfusion of the brain using the middle cerebral artery occlusion model. We found that EGFR was phosphorylated and transactivated during both ischemia and reperfusion periods. During ischemia, the activity of PI3K/AKT pathway was significantly increased, as judged from the strong phosphorylation of AKT; this activation was suppressed by the inhibitors of EGFR and Zn-dependent metalloproteinase. Ischemia, however, did not induce ERK1/2 phosphorylation, which was dependent on reperfusion. Coimmunoprecipitation of Son of sevenless 1 (SOS1) with EGFR showed increased association between the receptor and SOS1 in ischemia, indicating the inhibitory node downstream of SOS1. The inhibitory phosphorylation site of Raf-1 at Ser259, but not its stimulatory phosphorylation site at Ser338, was phosphorylated during ischemia. Furthermore, ischemia prompted the interaction between Raf-1 and AKT, while both the inhibitors of PI3K and AKT not only abolished AKT phosphorylation but also restored ERK1/2 phosphorylation. All these findings suggest that Raf/MAPK/ERK1/2 signal pathway is inhibited by AKT via direct phosphorylation and inhibition at Raf-1 node during ischemia. During reperfusion, we observed a significant increase of ERK1/2 phosphorylation but no change in AKT phosphorylation. Inhibitors of reactive oxygen species and phosphatase and tensin homolog restored AKT phosphorylation but abolished ERK1/2 phosphorylation, suggesting that the reactive oxygen species-dependent increase in phosphatase and tensin homolog activity in reperfusion period relieves ERK1/2 from inhibition of AKT.
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Affiliation(s)
- Jing Zhou
- Laboratory of Metabolic Brain Diseases, Institute of Metabolic Disease Research and Drug Development, China Medical University, Shenyang, P. R. China
| | - Ting Du
- Laboratory of Metabolic Brain Diseases, Institute of Metabolic Disease Research and Drug Development, China Medical University, Shenyang, P. R. China
| | - Baoman Li
- Laboratory of Metabolic Brain Diseases, Institute of Metabolic Disease Research and Drug Development, China Medical University, Shenyang, P. R. China
| | - Yan Rong
- Laboratory of Metabolic Brain Diseases, Institute of Metabolic Disease Research and Drug Development, China Medical University, Shenyang, P. R. China
| | - Alexei Verkhratsky
- Faculty of Life Science, The University of Manchester, UK Achucarro Center for Neuroscience, IKERBASQUE, Basque Foundation for Science, Bilbao, Spain University of Nizhny Novgorod, Russia
| | - Liang Peng
- Laboratory of Metabolic Brain Diseases, Institute of Metabolic Disease Research and Drug Development, China Medical University, Shenyang, P. R. China
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15
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Phosphorylation of PTEN at STT motif is associated with DNA damage response. Mutat Res 2014; 770:112-9. [PMID: 25771877 DOI: 10.1016/j.mrfmmm.2014.08.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2013] [Revised: 08/05/2014] [Accepted: 08/26/2014] [Indexed: 01/02/2023]
Abstract
Phosphatase and tensin homolog deleted on chromosome Ten (PTEN), a tumor suppressor protein participates in multiple cellular activities including DNA repair. In this work we found a relationship between phosphorylation of carboxy (C)-terminal STT motif of PTEN and DNA damage response. Ectopic expression of C-terminal phospho-mutants of PTEN, in PTEN deficient human glioblastoma cells, U87MG, resulted in reduced viability and DNA repair after etoposide induced DNA damage compared to cells expressing wild type PTEN. Also, after etoposide treatment phosphorylation of PTEN increased at C-terminal serine 380 and threonine 382/383 residues in PTEN positive HEK293T cells and wild type PTEN transfected U87MG cells. One-step further, DNA damage induced phosphorylation of PTEN was confirmed by immunoprecipitation of total PTEN from cellular extract followed by immunobloting with phospho-specific PTEN antibodies. Additionally, phospho-PTEN translocated to nucleus after etoposide treatment as revealed by indirect immunolabeling. Further, phosphorylation dependent nuclear foci formation of PTEN was observed after ionizing radiation or etoposide treatment which colocalized with γH2AX. Additionally, etoposide induced γH2AX, Mre11 and Ku70 foci persisted for a longer period of times in U87MG cells after ectopic expression of PTEN C-terminal phospho-mutant constructs compared to wild type PTEN expressing cells. Thus, our findings strongly suggest that DNA damage induced phosphorylation of C-terminal STT motif of PTEN is necessary for DNA repair.
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Tarnawski AS, Ahluwalia A, Jones MK. Increased susceptibility of aging gastric mucosa to injury: the mechanisms and clinical implications. World J Gastroenterol 2014; 20:4467-4482. [PMID: 24782600 PMCID: PMC4000484 DOI: 10.3748/wjg.v20.i16.4467] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/13/2014] [Revised: 01/30/2014] [Accepted: 04/01/2014] [Indexed: 02/06/2023] Open
Abstract
This review updates the current views on aging gastric mucosa and the mechanisms of its increased susceptibility to injury. Experimental and clinical studies indicate that gastric mucosa of aging individuals-"aging gastropathy"-has prominent structural and functional abnormalities vs young gastric mucosa. Some of these abnormalities include a partial atrophy of gastric glands, impaired mucosal defense (reduced bicarbonate and prostaglandin generation, decreased sensory innervation), increased susceptibility to injury by a variety of damaging agents such as ethanol, aspirin and other non-steroidal anti-inflammatory drugs (NSAIDs), impaired healing of injury and reduced therapeutic efficacy of ulcer-healing drugs. Detailed analysis of the above changes indicates that the following events occur in aging gastric mucosa: reduced mucosal blood flow and impaired oxygen delivery cause hypoxia, which leads to activation of the early growth response-1 (egr-1) transcription factor. Activation of egr-1, in turn, upregulates the dual specificity phosphatase, phosphatase and tensin homologue deleted on chromosome ten (PTEN) resulting in activation of pro-apoptotic caspase-3 and caspase-9 and reduced expression of the anti-apoptosis protein, survivin. The imbalance between pro- and anti-apoptosis mediators results in increased apoptosis and increased susceptibility to injury. This paradigm has human relevance since increased expression of PTEN and reduced expression of survivin were demonstrated in gastric mucosa of aging individuals. Other potential mechanisms operating in aging gastric mucosa include reduced telomerase activity, increase in replicative cellular senescence, and reduced expression of vascular endothelial growth factor and importin-α-a nuclear transport protein essential for transport of transcription factors to nucleus. Aging gastropathy is an important and clinically relevant issue because of: (1) an aging world population due to prolonged life span; (2) older patients have much greater risk of gastroduodenal ulcers and gastrointestinal complications (e.g., NSAIDs-induced gastric injury) than younger patients; and (3) increased susceptibility of aging gastric mucosa to injury can be potentially reduced or reversed pharmacologically.
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Abstract
Phosphoinositides are the phosphorylated derivatives of phosphatidylinositol, and play a very significant role in a diverse range of signaling processes in eukaryotic cells. A number of phosphoinositide-metabolizing enzymes, including phosphoinositide-kinases and phosphatases are involved in the synthesis and degradation of these phospholipids. Recently, the function of various phosphatases in the phosphatidylinositol signaling pathway has been of great interest. In the present review we summarize the structural insights and biochemistry of various phosphatases in regulating phosphoinositide metabolism.
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Affiliation(s)
- Young Jun Kim
- Department of Biotechnology, Konkuk University, Chungju, Korea
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18
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Li Z, Liu GX, Liu YL, Chen X, Huang XL, Gan HT. Effect of adenovirus-mediated PTEN gene on ulcerative colitis-associated colorectal cancer. Int J Colorectal Dis 2013; 28:1107-15. [PMID: 23516074 DOI: 10.1007/s00384-013-1678-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 03/05/2013] [Indexed: 02/04/2023]
Abstract
PURPOSE This study investigated the expression pattern of PTEN and its effect on carcinogenesis of ulcerative colitis-associated colorectal cancer, leading to insights into the underlying molecular mechanism. METHODS We established a mouse model of ulcerative colitis-associated colorectal cancer by treating the animals with azoxymethane (AOM) and dextran sulphate sodium (DSS), and investigated the inflammation-dysplasia-carcinoma sequence. Expression patterns of PTEN, p-Akt and Ki-67 were shown by immunohistochemistry; western blotting techniques were used to detect protein expression of PTEN, p-Akt and caspase 3; TUNEL assay was used to measure apoptosis in colon epithelial cells; and colorimetric analysis was able to determine MPO activity in colon tissues. RESULTS During the inflammation-dysplasia-carcinoma sequence, PTEN expression gradually decreased, while p-Akt expression increased; PTEN and p-Akt levels were negatively correlated. Compared to the AOM-DSS and Ad-0 groups, Ad-PTEN mice had longer colons, fewer tumours (P < 0.01) and smaller tumour sizes (P < 0.05). After injecting Ad-PTEN, expression of p-Akt, Ki-67 and MPO activity decreased dramatically, whereas PTEN increased. The TUNEL assay showed increased apoptotic cells and caspase 3 expression in the Ad-PTEN group. CONCLUSION PTEN plays an important role in the inflammation-dysplasia-carcinoma sequence and may be a new molecular target in preventing and treating ulcerative colitis-associated colorectal cancer.
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Affiliation(s)
- Zhi Li
- Department of Gastroenterology and Geriatrics Medicine, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, China
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19
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Luo L, Gong YQ, Qi X, Lai W, Lan H, Luo Y. Effect of tumor suppressor PTEN gene on apoptosis and cell cycle of human airway smooth muscle cells. Mol Cell Biochem 2012; 375:1-9. [PMID: 23275086 DOI: 10.1007/s11010-012-1484-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2012] [Accepted: 10/17/2012] [Indexed: 01/29/2023]
Abstract
It is well established that hyperplasia and decreased apoptosis of airway smooth muscle cells (ASMCs) play an important role in the asthmatic airway remodeling. Tumor suppressor PTEN gene with phosphatase activity plays an important regulatory role in embryonic development, cell proliferation, and apoptosis, cell cycle regulation, migration (invasion) of the cytoskeleton. We hypotheses that PTEN gene could affect the growth and viability of ASMCs through the regulation of PI3K/Akt, MAPK, and cell cycle-related gene expression. We constructed a recombinant adenovirus to transfect ASMCs. Cells were divided into the overexpression of PTEN gene group (Ad-PTEN-GFP), negative control group (Ad-GFP), and blank control group (DMEM). The cell apoptosis of ASMCs were evaluated by Hoechst-33342 staining and PE-7AAD double-labeled flow cytometry. The cell cycle distribution was observed by flow cytometry with PI staining. The expression of PTEN, p-Akt, total-Akt, p-ERK1/2, total-ERK1/2, cleaved-Caspases-3, Caspases-9, p21, and Cyclin D1 were tested by the Western blotting. Our study revealed that overexpression of PTEN gene did not induce apoptosis of human ASMCs cultured in vitro. However, overexpression of PTEN inhibited proliferation of human ASMCs cultured in vitro and was associated with downregulation of Akt phosphorylation levels, while did not affect ERK1/2 phosphorylation levels. Moreover, overexpression of PTEN could induce ASMCs arrested in the G0/G1 phase through the downregulation of Cyclin D1 and upregulation of p21 expressions.
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Affiliation(s)
- Liang Luo
- Department of Medical Intensive Care Unit, The First Affiliated Hospital of Sun Yat-sen University, No. 58, Zhong Shan Er Road, Guangzhou, People's Republic of China
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20
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Reddy SDN, Pakala SB, Molli PR, Sahni N, Karanam NK, Mudvari P, Kumar R. Metastasis-associated protein 1/histone deacetylase 4-nucleosome remodeling and deacetylase complex regulates phosphatase and tensin homolog gene expression and function. J Biol Chem 2012; 287:27843-50. [PMID: 22700976 PMCID: PMC3431680 DOI: 10.1074/jbc.m112.348474] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2012] [Revised: 06/13/2012] [Indexed: 12/11/2022] Open
Abstract
Metastasis-associated protein 1 (MTA1) is widely overexpressed in human cancers and is associated with malignant phenotypic changes contributing to morbidity in the associated diseases. Here we discovered for the first time that MTA1, a master chromatin modifier, transcriptionally represses the expression of phosphatase and tensin homolog (PTEN), a tumor suppressor gene, by recruiting class II histone deacetylase 4 (HDAC4) along with the transcription factor Yin-Yang 1 (YY1) onto the PTEN promoter. We also found evidence of an inverse correlation between the expression levels of MTA1 and PTEN in physiologically relevant breast cancer microarray datasets. We found that MTA1 up-regulation leads to a decreased expression of PTEN protein and stimulation of PI3K as well as phosphorylation of its signaling targets. Accordingly, selective down-regulation of MTA1 in breast cancer cells increases PTEN expression and inhibits stimulation of the PI3K/AKT signaling. Collectively, these findings provide a mechanistic role for MTA1 in transcriptional repression of PTEN, leading to modulation of the resulting signaling pathways.
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Affiliation(s)
- Sirigiri Divijendra Natha Reddy
- From the Department of Biochemistry and Molecular Biology, School of Medicine and Health Sciences, The George Washington University, Washington, D. C. 20037
| | - Suresh B. Pakala
- From the Department of Biochemistry and Molecular Biology, School of Medicine and Health Sciences, The George Washington University, Washington, D. C. 20037
| | - Poonam R. Molli
- From the Department of Biochemistry and Molecular Biology, School of Medicine and Health Sciences, The George Washington University, Washington, D. C. 20037
| | - Neil Sahni
- From the Department of Biochemistry and Molecular Biology, School of Medicine and Health Sciences, The George Washington University, Washington, D. C. 20037
| | - Narasimha Kumar Karanam
- From the Department of Biochemistry and Molecular Biology, School of Medicine and Health Sciences, The George Washington University, Washington, D. C. 20037
| | - Prakriti Mudvari
- From the Department of Biochemistry and Molecular Biology, School of Medicine and Health Sciences, The George Washington University, Washington, D. C. 20037
| | - Rakesh Kumar
- From the Department of Biochemistry and Molecular Biology, School of Medicine and Health Sciences, The George Washington University, Washington, D. C. 20037
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21
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Gupta A, Dey CS. PTEN, a widely known negative regulator of insulin/PI3K signaling, positively regulates neuronal insulin resistance. Mol Biol Cell 2012; 23:3882-98. [PMID: 22875989 PMCID: PMC3459864 DOI: 10.1091/mbc.e12-05-0337] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Lipid and protein tyrosine phosphatase, phosphatase and tension homologue (PTEN), is a widely known negative regulator of insulin/phosphoinositide 3-kinase signaling. Down-regulation of PTEN is thus widely documented to ameliorate insulin resistance in peripheral tissues such as skeletal muscle and adipose. However, not much is known about its exact role in neuronal insulin signaling and insulin resistance. Moreover, alterations of PTEN in neuronal systems have led to discovery of several unexpected outcomes, including in the neurodegenerative disorder Alzheimer's disease (AD), which is increasingly being recognized as a brain-specific form of diabetes. In addition, contrary to expectations, its neuron-specific deletion in mice resulted in development of diet-sensitive obesity. The present study shows that PTEN, paradoxically, positively regulates neuronal insulin signaling and glucose uptake. Its down-regulation exacerbates neuronal insulin resistance. The positive role of PTEN in neuronal insulin signaling is likely due to its protein phosphatase actions, which prevents the activation of focal adhesion kinase (FAK) and extracellular signal-regulated kinase (ERK), the kinases critically involved in neuronal energy impairment and neurodegeneration. Results suggest that PTEN acting through FAK, the direct protein substrate of PTEN, prevents ERK activation. Our findings provide an explanation for unexpected outcomes reported earlier with PTEN alterations in neuronal systems and also suggest a novel molecular pathway linking neuronal insulin resistance and AD, the two pathophysiological states demonstrated to be closely linked.
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Affiliation(s)
- Amit Gupta
- Department of Biotechnology, National Institute of Pharmaceutical Education and Research, Punjab, India
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22
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Nongenomic Mechanisms of PTEN Regulation. Int J Cell Biol 2012; 2012:379685. [PMID: 22536248 PMCID: PMC3320059 DOI: 10.1155/2012/379685] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2011] [Revised: 01/16/2012] [Accepted: 01/17/2012] [Indexed: 11/21/2022] Open
Abstract
A large amount of data supports the view that PTEN is a bona fide tumor suppressor gene. However, recent evidence suggests that derailment of cellular localization and expression levels of functional nonmutated PTEN is a determining force in inducing abnormal cellular and tissue outcomes. As the cellular mechanisms that regulate normal PTEN enzymatic activity resolve, it is evident that deregulation of these mechanisms can alter cellular processes and tissue architecture and ultimately lead to oncogenic transformation. Here we discuss PTEN ubiquitination, PTEN complex formation with components of the adherens junction, PTEN nuclear localization, and microRNA regulation of PTEN as essential regulatory mechanisms that determine PTEN function independent of gene mutations and epigenetic events.
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Taddei ML, Giannoni E, Fiaschi T, Chiarugi P. Anoikis: an emerging hallmark in health and diseases. J Pathol 2012; 226:380-93. [PMID: 21953325 DOI: 10.1002/path.3000] [Citation(s) in RCA: 448] [Impact Index Per Article: 34.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Anoikis is a programmed cell death occurring upon cell detachment from the correct extracellular matrix, thus disrupting integrin ligation. It is a critical mechanism in preventing dysplastic cell growth or attachment to an inappropriate matrix. Anoikis prevents detached epithelial cells from colonizing elsewhere and is thus essential for tissue homeostasis and development. As anchorage-independent growth and epithelial-mesenchymal transition, two features associated with anoikis resistance, are crucial steps during tumour progression and metastatic spreading of cancer cells, anoikis deregulation has now evoked particular attention from the scientific community. The aim of this review is to analyse the molecular mechanisms governing both anoikis and anoikis resistance, focusing on their regulation in physiological processes, as well as in several diseases, including metastatic cancers, cardiovascular diseases and diabetes.
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Affiliation(s)
- M L Taddei
- Department of Biochemical Sciences, University of Florence, and Tumour Institute and Centre for Research, Transfer and High Education DenoTHE, Florence, Italy
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Abstract
MicroRNAs (miRNAs) are involved in almost every aspect of a mammalian cell's functionality, from stem cell differentiation to aging and pathogenesis; however, their role in immediate cell signaling is less defined. This has been recently demonstrated by the rapid increase or decrease of miR-21's abundance within minutes of activation or inhibition of the v-akt murine thymoma viral oncogene homolog 1 (AKT) pathway, respectively, which mediates its regulation of Fas ligand and phosphatase and tensin homologue deleted on chromosome 10 expression, among other targets. Conversely, AKT induces rapid downregulation of miR-199a-5p to effect upregulation of hypoxia-inducible factor 1α and sirtuin 1. This suggests that posttranscriptional mechanisms regulate miRNAs' processing and/or stability to induce the rapid fluctuation in their levels. In support, a growing number of studies are showing specific posttranscriptional regulation of miRNAs. The data potentially explain how AKT, and plausibly other signaling pathways, can specifically and promptly modulate a gene's translation while circumventing the need for transcription during transient signaling events.
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Affiliation(s)
- Maha Abdellatif
- Cardiovascular Research Institute, Department of Cell Biology and Molecular Medicine, University of Medicine and Dentistry of New Jersey, Newark, NJ 07103, USA.
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25
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Abstract
MicroRNAs are involved in almost every aspect of a mammalian cell's functionality, from stem cell differentiation to aging and pathogenesis; however, their role in immediate cell signaling is less defined. This has been recently demonstrated by the rapid increase or decrease of miR-21's abundance within minutes of activation or inhibition of the AKT pathway, respectively, which mediates its regulation of Fas ligand (FasL) and phosphatase and tensin homologue deleted on chromosome 10 (PTEN) expression, among other targets. Conversely, AKT induces rapid downregulation of miR-199a-5p to effect upregulation of hypoxia-inducible factor 1α Hif-1α and sirtuin 1 (Sirt1). This suggests that posttranscriptional mechanisms regulate miRNAs' processing and/or stability to induce the rapid fluctuation in their levels. In support, a growing number of studies are showing specific posttranscriptional regulation of miRNAs. The data potentially explain how AKT, and plausibly other signaling pathways, can specifically and promptly modulate a gene's translation while circumventing the need for transcription during transient signaling events. In this article we present our views regarding cell signaling via miRNAs.
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Affiliation(s)
- Danish Sayed
- Department of Cell Biology and Molecular Medicine, Cardiovascular Research Institute, University of Medicine and Dentistry of New Jersey, Newark, NJ, USA
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Sayed D, He M, Hong C, Gao S, Rane S, Yang Z, Abdellatif M. MicroRNA-21 is a downstream effector of AKT that mediates its antiapoptotic effects via suppression of Fas ligand. J Biol Chem 2010; 285:20281-90. [PMID: 20404348 DOI: 10.1074/jbc.m110.109207] [Citation(s) in RCA: 266] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
MicroRNA-21 (miR-21) is highly up-regulated during hypertrophic and cancerous cell growth. In contrast, we found that it declines in cardiac myocytes upon exposure to hypoxia. Thus, the objective was to explore its role during hypoxia. We show that miR-21 not only regulates phosphatase and tensin homologue deleted on chromosome 10 (PTEN), but also targets Fas ligand (FasL). During prolonged hypoxia, down-regulation of miR-21 proved necessary and sufficient for enhancing expression of both proteins. We demonstrate here for the first time that miR-21 is positively regulated via an AKT-dependent pathway, which is depressed during prolonged hypoxia. Accordingly, hypoxia-induced down-regulation of miR-21 and up-regulation of FasL and PTEN were reversed by activated AKT and reproduced by a dominant negative mutant, wortmannin, or PTEN. Moreover, the antiapoptotic function of AKT partly required miR-21, which was sufficient for inhibition of caspase-8 activity and mitochondrial damage. In consensus, overexpression of miR-21 in a transgenic mouse heart resulted in suppression of ischemia-induced up-regulation of PTEN and FasL expression, an increase in phospho-AKT, a smaller infarct size, and ameliorated heart failure. Thus, we have identified a unique aspect of the function of AKT by which it inhibits apoptosis through miR-21-dependent suppression of FasL.
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Affiliation(s)
- Danish Sayed
- Cardiovascular Research Institute, Department of Cell Biology and Molecular Medicine, University of Medicine and Dentistry of New Jersey, Newark, New Jersey 07103, USA
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Sakamoto S, Kyprianou N. Targeting anoikis resistance in prostate cancer metastasis. Mol Aspects Med 2010; 31:205-14. [PMID: 20153362 DOI: 10.1016/j.mam.2010.02.001] [Citation(s) in RCA: 139] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2009] [Accepted: 02/06/2010] [Indexed: 01/20/2023]
Abstract
Anoikis is a mode of apoptotic cell death, consequential to insufficient cell-matrix interactions and a critical player in tumor angiogenesis and metastasis. The events involved in tumor cell progression toward metastasis potential are mediated by integrins, which upon engagement with components of the extracellular matrix (ECM), reorganize to form adhesion complexes. Targeting apoptotic players is of immense therapeutic significance since resistance to apoptosis is not only critical in conferring therapeutic failure to standard treatment strategies, but anoikis (apoptosis upon loss of anchorage and detachment from ECM) also plays an important role in angiogenesis and metastasis. The ability to survive in the absence of adhesion to the ECM, enables tumor cells to disseminate from the primary tumor site, invade a distant site and establish a metastatic lesion. Tumor cells can escape from detachment-induced apoptosis by controlling anoikis pathways, including the extrinsic death receptor pathway and the ECM-integrin mediated cell survival pathway. Considering the functional promiscuity of individual signaling effectors, it is critical to dissect the molecular networks mechanistically driving tumor cells to evade anoikis and embark on a metastatic spread. Resistance to die via anoikis dictates tumor cell survival and provides a molecular basis for therapeutic targeting of metastatic prostate cancer. Further dissection of critical anoikis signaling events will enable the therapeutic optimization of anoikis targeting to impair prostate cancer metastasis prior to its initiation. This review will discuss the molecular understanding of anoikis regulation in the tumor microenvironment and the in vivo pharmacological implementation of a novel class of antitumor-drugs to optimize apoptotic-based therapeutic targeting, bypassing anoikis-resistance to impair prostate cancer progression to metastasis. Potential combination strategies targeting tumor vascularity (via anoikis) and impairing tumor initiation (via "classic" apoptosis), provide strong therapeutic promise for metastatic prostate cancer by preventing the onset of metastasis.
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Affiliation(s)
- Shinichi Sakamoto
- Department of Surgery/Urology, University of Kentucky College of Medicine, Lexington, KY, USA
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Friedland DR, Eernisse R, Erbe C, Gupta N, Cioffi JA. Cholesteatoma growth and proliferation: posttranscriptional regulation by microRNA-21. Otol Neurotol 2009; 30:998-1005. [PMID: 19672202 PMCID: PMC2828528 DOI: 10.1097/mao.0b013e3181b4e91f] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
OBJECTIVES The goal of this study was to identify novel regulatory mechanisms controlling the growth and proliferation of cholesteatoma. Specifically, the potential role of microRNAs, regulators of protein translation, was studied in cholesteatoma. STUDY DESIGN This study represents a molecular biologic investigation characterizing and comparing microRNA and protein expression in cholesteatoma and normal postauricular skin. METHODS Cholesteatoma and normal skin were taken from patients at the time of surgery. Tissue was processed for RNA and protein extraction. Real-time reverse-transcriptase-polymerase chain reaction was used to assess levels of human microRNAs, reverse-transcriptase-polymerase chain reaction was used to confirm the presence of upstream regulators, and Western blot analyses were used to assess levels of downstream target proteins. RESULTS Among the microRNAs investigated, human microRNA-21 (hsa-miR-21) showed a 4.4-fold higher expression in cholesteatoma as compared with normal skin (p = 0.0011). The downstream targets of hsa-miR-21, PTEN and programmed cell death 4, were found to be greatly reduced in 3 of 4 cholesteatoma samples. Proposed upstream regulators of hsa-miR-21 expression (CD14, interleukin 6R, gp130, and signal transducer and activator of transcription 3) were present in all cholesteatoma tissues. CONCLUSION MicroRNAs represent powerful regulators of protein translation, and their dysregulation has been implicated in many neoplastic diseases. This study specifically identified up-regulation of hsa-miR-21 concurrent with down-regulation of potent tumor suppressor proteins PTEN and programmed cell death 4. These proteins control aspects of apoptosis, proliferation, invasion, and migration. The results of this study were used to develop a model for cholesteatoma proliferation through microRNA dysregulation. This model can serve as a template for further study into potential RNA-based therapies for the treatment of cholesteatoma.
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Affiliation(s)
- David R Friedland
- Department of Otolaryngology and Communication Sciences, Medical College of Wisconsin, Milwaukee, Wisconsin 53226, USA.
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Fournier MV, Fata JE, Martin KJ, Yaswen P, Bissell MJ. Interaction of E-cadherin and PTEN regulates morphogenesis and growth arrest in human mammary epithelial cells. Cancer Res 2009; 69:4545-52. [PMID: 19417140 DOI: 10.1158/0008-5472.can-08-1694] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Phosphatase and tensin homologue deleted on chromosome 10 (PTEN) is a dual-function phosphatase with tumor suppressor function compromised in a wide spectrum of cancers. Because tissue polarity and architecture are crucial modulators of normal and malignant behavior, we postulated that PTEN may play a role in maintenance of tissue integrity. We used two nonmalignant human mammary epithelial cell lines that form polarized, growth-arrested structures (acini) when cultured in three-dimensional laminin-rich extracellular matrix gels (lrECM). As acini begin to form, PTEN accumulates both in the cytoplasm and at cell-cell contacts where it colocalizes with the E-cadherin/beta-catenin complex. Reduction of PTEN levels by shRNA in lrECM prevents formation of organized breast acini and disrupts growth arrest. Importantly, disruption of acinar polarity and cell-cell contact by E-cadherin function-blocking antibodies reduces endogenous PTEN protein levels and inhibits its accumulation at cell-cell contacts. Conversely, in Skbr-3 breast cancer cells lacking endogenous E-cadherin expression, exogenous introduction of E-cadherin gene causes induction of PTEN expression and its accumulation at sites of cell interactions. These studies provide evidence that E-cadherin regulates both the PTEN protein levels and its recruitment to cell-cell junctions in three-dimensional lrECM, indicating a dynamic reciprocity between architectural integrity and the levels and localization of PTEN. This interaction thus seems to be a critical integrator of proliferative and morphogenetic signaling in breast epithelial cells.
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Affiliation(s)
- Marcia V Fournier
- Life Science Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
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Tarnawski A, Pai R, Deng X, Ahluwalia A, Khomenko T, Tanigawa T, Akahoshi T, Sandor Z, Szabo S. Aging gastropathy-novel mechanisms: hypoxia, up-regulation of multifunctional phosphatase PTEN, and proapoptotic factors. Gastroenterology 2007; 133:1938-1947. [PMID: 18054565 DOI: 10.1053/j.gastro.2007.08.037] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/15/2006] [Accepted: 07/19/2007] [Indexed: 02/06/2023]
Abstract
BACKGROUND & AIMS Aging gastric mucosa has impaired mucosal defense and increased susceptibility to injury. Our aims were to determine the mechanisms responsible for above abnormalities. METHODS We used Fisher F-344 rats, 3 and 24 months of age. We measured gastric mucosal blood flow; visualized mucosal hypoxia; examined expression of early growth response-1 transcription factor and phosphatase and tensin homologue deleted on chromosome 10 (PTEN); assessed apoptosis; and determined expression of caspase-3, caspase-9, and survivin. We also examined susceptibility of gastric mucosa of young and aging rats to ethanol injury and whether down-regulation of PTEN affects susceptibility of aging gastric mucosa to injury. To determine human relevance, we examined expression of PTEN and survivin in human gastric specimens of young and aging individuals. RESULTS Gastric mucosa of aging (vs young) rats has a 60% reduction in mucosal blood flow; prominent hypoxia; and increased early growth response-1 transcription factor and PTEN messenger RNAs, and proteins. It also has increased expression of proapoptotic proteins caspase-3 and capase-9, reduced survivin, and a 6-fold increased apoptosis vs mucosa of young rats. Ethanol-induced gastric mucosal injury in aging (vs young) rats was significantly increased. The down-regulation of PTEN in gastric mucosa of aging rats completely reversed its increased susceptibility to ethanol injury. In aging human gastric mucosa, PTEN expression was significantly increased, whereas survivin was significantly reduced. CONCLUSIONS (1) Gastric mucosa of aging rats has significantly reduced blood flow, tissue hypoxia, activation of Egr-1, PTEN; increased caspases; and reduced survivin. (2) These changes increase susceptibility of aging gastric mucosa to injury.
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Affiliation(s)
- Andrzej Tarnawski
- Department of Medicine, VA Long Beach Healthcare System and the University of California, Irvine, California, USA.
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Rice KM, Desai DH, Preston DL, Wehner PS, Blough ER. Uniaxial stretch-induced regulation of mitogen-activated protein kinase, Akt and p70 S6 kinase in the ageing Fischer 344 x Brown Norway rat aorta. Exp Physiol 2007; 92:963-70. [PMID: 17526558 DOI: 10.1113/expphysiol.2007.037275] [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] [Indexed: 11/08/2022]
Abstract
The effects of ageing on the cardiovascular system contribute to substantial alterations in cellular morphology and function. The variables regulating these changes are unknown; however, one set of signalling molecules that may be of particular importance in mediating numerous cellular responses, including control of cell growth, differentiation and adaptation, are the proteins associated with the mitogen-activated protein kinase (MAPK) signalling systems. The MAPKs, in conjunction with the p70 S6k signalling cascade, have emerged as critical components for regulating numerous mechanotransduction-related cellular responses. Here we investigate the ability of uniaxial stretch to activate the MAPK and p70 S6k pathways in adult (6-month-old), aged (30-month-old) and very aged (36-month-old) Fischer 344/NNiaHSd x Brown Norway/BiNia (FBN) rats. Western blotting of the MAPK family proteins extracellular signal-regulated kinase (Erk) 1/2, p38- and c-Jun NH(2)-terminal kinase (Jnk)-MAPKs showed differential expression and activation between these proteins with age. An acute 15 min interval of 20% uniaxial stretch using an ex vivo aortic preparation demonstrated similar regulation of Erk1/2, p38- and Jnk-MAPK. However, ageing altered uniaxial induced p70 S6k pathway signalling. These observations confirm previous data demonstrating that MAPK proteins are mechanically regulated and also suggest that p70 S6k signalling expression and activation are controlled differently with ageing. Taken together, these data may help to explain, in part, the age-related changes in vascular morphology, function and response to injury.
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Affiliation(s)
- Kevin M Rice
- Department of Biological Sciences, Marshall University, Huntington, WV 25755-1090, USA
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Affiliation(s)
- Mihaela M Mocanu
- The Hatter Cardiovascular Institute, University College London Hospital and Medical School, Chenies Mew, London, WC1E 6HX, UK
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Abstract
Myocardial ischaemia/reperfusion injury leading to myocardial infarction is one of the most frequent causes of debilitation and death in man. Considerable research has been undertaken to investigate the possibility of reducing myocardial infarction and increasing cell survival by activating certain endogenous prosurvival signaling pathways. Thus, it has been established that the activation of the PI3K (Phosphoinositide-3 kinase)/Akt (Protein kinase B, PKB) signaling pathway is essential for protection against ischaemia/reperfusion injury. This pathway has been shown to be activated by mechanical procedures (e.g. pre and post conditioning) as well as by a number of pharmacological agents. Although the activation of this prosurvival signaling pathway induces the phosphorylation of a large number of substrates implicated in increased cell survival, when activated over a prolonged period this pathway can have detrimental consequences by facilitating unwanted growth and malignancies. Importantly PTEN (phosphatase and tensin homolog deleted on chromosome ten), is the main phosphatase which negatively regulates the PI3K/Akt pathway. In this review we discuss: a) the significance and the limitations of inhibiting PTEN in myocardial ischaemia/reperfusion injury; b) PTEN and its relationship to ischaemic preconditioning, c) the role of PTEN in the development of tolerance to chronic administration of drugs known to limit infarction by activating PI3K/Akt pathway when given acutely, and d) the possible role of PTEN in the ischaemic/reperfused diabetic heart. The experimental evidence discussed in this review illustrates the importance of PTEN inhibition in the protection of the heart against ischaemia/reperfusion injury.
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Affiliation(s)
- M M Mocanu
- The Hatter Cardiovascular Institute, Department of Medicine, UCL Chenies Mews, London, UK
| | - D M Yellon
- The Hatter Cardiovascular Institute, Department of Medicine, UCL Chenies Mews, London, UK
- Author for correspondence:
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Oh JH, Kim A, Park JM, Kim SH, Chung AS. Ultraviolet B-induced matrix metalloproteinase-1 and -3 secretions are mediated via PTEN/Akt pathway in human dermal fibroblasts. J Cell Physiol 2007; 209:775-85. [PMID: 16972255 DOI: 10.1002/jcp.20754] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Matrix Metalloproteinases (MMPs) are crucial enzymes for ultraviolet irradiation-induced photoaging in human skin. Ultraviolet B (UVB) stimulates dermal fibroblasts to increase MMP-1 and -3 expression and extracellular matrix (ECM) degradation in photoaging. We investigated whether phosphatase and tensin homolog (PTEN)/Akt pathway is involved in secretions of MMP-1 and -3 in human dermal fibroblasts. The increase in MMP-1 and -3 expression and secretion occurred along with the increase in PTEN and Akt phosphorylation by UVB irradiation in a dose- and time-dependent manner. However, treatment with a casein kinase 2 inhibitor, 5,6-dichloro-1-beta-D-ribofuranosyl-benzimidazole, inhibited their phosphorylations and MMP-1 and -3 secretions. Transfection of wild-type PTEN (Wt-PTEN) decreased basal and UVB-induced MMP-1 and -3 secretions, as well as activator protein-1 (AP-1) activity, while transfection of small interference RNA of PTEN (siRNA-PTEN), phosphatase-inactive PTEN (C124S-PTEN), or lipid phosphatase-inactive PTEN (G129E-PTEN) increased basal or UVB-induced MMP-1 and -3 secretions and AP-1 activity. Transfection of constitutively active Akt (Myr-Akt) also increased basal or UVB-induced MMP-1 and -3 secretions, as well as AP-1 activity. However, transfection of kinase-inactive Akt (K179M-Akt) decreased their secretions, but showed no significant change of AP-1 activity without UVB irradiation, and a significant increase of AP-1 activity with UVB irradiation. Treatment with the phosphatidylinositol 3-kinase inhibitors, LY294002 or wortmannin, downregulated basal and UVB-induced MMP-1 and -3 secretions. In conclusion, UVB irradiation increases PTEN and Akt phosphorylation in human dermal fibroblasts, and these inhibition of PTEN and activation of Akt by phosphorylation are involved in UVB-induced MMP-1 and -3 secretions partly through upregulation of AP-1 activity.
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Affiliation(s)
- Jang-Hee Oh
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, 373-1 Guseong-dong, Yuseong-gu, Daejeon 305-701, South Korea
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Cannon JD, Cherian-Shaw M, Lovekamp-Swan T, Chaffin CL. Granulosa cell expression of G1/S phase cyclins and cyclin-dependent kinases in PMSG-induced follicle growth. Mol Cell Endocrinol 2007; 264:6-15. [PMID: 17084963 DOI: 10.1016/j.mce.2006.09.015] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2006] [Revised: 09/25/2006] [Accepted: 09/28/2006] [Indexed: 12/24/2022]
Abstract
Follicular development involves a complex orchestration of granulosa cell proliferation and differentiation. It is becoming increasingly apparent that the rate of granulosa cell proliferation declines as follicles reach the large antral status, prior to an ovulatory gonadotropin stimulus, although a precise time course and mechanism for this decline has not been described. The goal of the present study was to characterize granulosa cell proliferation following the onset of antral follicle growth in PMSG-primed immature rats, with emphasis on G1/S phase cyclins and cyclin-dependent kinases. Flow cytometric analysis demonstrated that the percentage of granulosa cells in S phase peaked 24-30 h post-PMSG and declined to control levels 48 h after PMSG administration. Expression of both Cyclin D2 and Cdk 4 was highest 12h post-PMSG and decreased to control levels by 48 h. In addition, Cdk 2 protein increased transiently 12-24h after PMSG. Cyclin E expression increased significantly by 12h but remained elevated through 48 h, and multiple isoforms of Cyclin E were observed with increased proliferation. Both Cdk 4 and Cdk 2 activity parallel protein expression, although, changes in Cdk 2 were more marked. Levels of mRNA for the cell cycle inhibitors p21CIP1 and p27KIP1 increased significantly by 48 h post-PMSG. These results demonstrate that PMSG-stimulated movement of granulosa cells across the G1/S boundary during follicle growth is transient. In addition, the control of granulosa cell proliferation may reside through the regulation of both Cdk 2 and Cdk 4.
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Affiliation(s)
- Jennifer D Cannon
- Department of Physiology, Medical College of Georgia, Augusta, GA 30912, USA
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Schick V, Majores M, Engels G, Spitoni S, Koch A, Elger CE, Simon M, Knobbe C, Blümcke I, Becker AJ. Activation of Akt independent of PTEN and CTMP tumor-suppressor gene mutations in epilepsy-associated Taylor-type focal cortical dysplasias. Acta Neuropathol 2006; 112:715-25. [PMID: 17013611 DOI: 10.1007/s00401-006-0128-y] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2006] [Revised: 07/28/2006] [Accepted: 07/28/2006] [Indexed: 01/18/2023]
Abstract
Focal cortical dysplasias (FCD) with Taylor-type balloon cells (FCD(IIb)) are frequently observed in biopsy specimens of patients with pharmacoresistant focal epilepsies. The molecular pathogenesis of FCD(IIb), which lack familial inheritance, is only poorly understood. Due to their highly differentiated, malformative nature and glioneuronal phenotype, FCD(IIb) share neuropathological characteristics with lesions observed in familial disorders such as cortical tubers present in patients with autosomal dominant tuberous sclerosis complex (TSC), related to mutations in the TSC1 or TSC2 genes, and dysplastic gangliocytomas of the cerebellum found in Cowden disease. Current data have indicated distinct allelic variants of TSC1 to accumulate in FCD(IIb). TSC1 represents a tumor suppressor operating in the phosphatidylinositol 3-kinase (PI3K)/insulin pathway. The tumor-suppressor gene PTEN is mutated in Cowden disease. Like PTEN, also carboxyl-terminal modulator protein (CTMP) modulates PI3K-pathway signaling, both via inhibition of Akt/PKB, a kinase inactivating the TSC1/TSC2 complex. Here, we have analyzed alterations of Akt, PTEN and CTMP relevant for insulin signaling upstream of TSC1/TSC2 in FCD(IIb). Immunohistochemistry with antibodies against phosphorylated Akt (phospho-Akt; Ser 473) in FCD(IIb) (n=23) showed strong phospho-Akt expression in dysplastic FCD(IIb) components. We have further studied sequence alterations of PTEN (n=34 FCD(IIb)) and CTMP (n=20 FCD(IIb)) by laser microdissection/single-strand conformation polymorphism analysis. We observed a somatic mutation in an FCD(IIb), i.e., amino-acid exchange at nucleotide position 834 (PTEN cDNA, GenBank AH007803.1) in exon 8 with replacement of phenylalanine by leucine (F278L). We also found several silent polymorphisms of PTEN in exon 2 and exon 8 as well as silent and coding polymorphisms but no mutations in CTMP. No loss of heterozygosity in FCD(IIb) (n=6) at 10q23 was observed. To our knowledge, we here report on the first somatic mutation of a tumor-suppressor gene, i.e., PTEN, in FCD(IIb). However, our study also demonstrates that mutational alterations of PTEN and CTMP do not play major pathogenetic roles for activation of Akt in FCD(IIb). Future studies need to determine the origin of insulin pathway activation upstream of TSC1/TSC2 in FCD(IIb).
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Affiliation(s)
- Volker Schick
- Department of Neuropathology, University of Bonn Medical Center, Sigmund-Freud-Str. 25, 53105, Bonn, Germany
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Zhang QG, Han D, Xu J, Lv Q, Wang R, Yin XH, Xu TL, Zhang GY. Ischemic preconditioning negatively regulates plenty of SH3s-mixed lineage kinase 3-Rac1 complex and c-Jun N-terminal kinase 3 signaling via activation of Akt. Neuroscience 2006; 143:431-44. [PMID: 16973299 DOI: 10.1016/j.neuroscience.2006.07.049] [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] [Received: 05/14/2006] [Revised: 07/24/2006] [Accepted: 07/26/2006] [Indexed: 01/22/2023]
Abstract
Activation of Akt/protein kinase B has been recently reported to play an important role in ischemic tolerance. We here demonstrate that the decreased protein expression and phosphorylation of phosphatase and tensin homolog deleted from chromosome 10 (PTEN) underlie the increased Akt-Ser-473 phosphorylation in the hippocampal CA1 subfield in ischemic preconditioning (IPC). Co-immunoprecipitation analysis reveals that Akt physically interacts with Rac1, a small Rho family GTPase required for mixed lineage kinase 3 (MLK3) autophosphorylation, and both this interaction and Rac1-Ser-71 phosphorylation induced by Akt are promoted in preconditioned rats. In addition, we show that Akt activation results in the disassembly of the plenty of SH3s (POSH)-MLK3-Rac1 signaling complex and down-regulation of the activation of MLK3/c-Jun N-terminal kinase (JNK) pathway. Akt activation results in decreased serine phosphorylation of 14-3-3, a cytoplasmic anchor of Bax, and prevents ischemia-induced mitochondrial translocation of Bax, release of cytochrome c, and activation of caspase-3. The expression of Fas ligand is also decreased in the CA1 region. Akt activation protects against apoptotic neuronal death as shown in TUNEL staining following IPC. Intracerebral infusion of LY294002 before IPC reverses the increase in Akt phosphorylation and the decrease in JNK signaling activation, as well as the neuroprotective action of IPC. Our results suggest that activation of pro-apoptotic MLK3/JNK3 cascade can be suppressed through activating anti-apoptotic phosphoinositide 3-kinase/Akt pathway induced by a sublethal ischemic insult, which provides a functional link between Akt and the JNK family of stress-activated kinases in ischemic tolerance.
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Affiliation(s)
- Q-G Zhang
- Research Center for Biochemistry and Molecular Biology, Xuzhou Medical College, 84 West Huai-hai Road, Xuzhou, Jiangsu 221002, China
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Rice KM, Desai DH, Kakarla SK, Katta A, Preston DL, Wehner P, Blough ER. Diabetes alters vascular mechanotransduction: pressure-induced regulation of mitogen activated protein kinases in the rat inferior vena cava. Cardiovasc Diabetol 2006; 5:18. [PMID: 16961925 PMCID: PMC1592078 DOI: 10.1186/1475-2840-5-18] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2006] [Accepted: 09/08/2006] [Indexed: 12/30/2022] Open
Abstract
Background Diabetes mellitus is an important risk factor for increased vein graft failure after bypass surgery. However, the cellular and molecular mechanism(s) underlying vessel attrition in this population remain largely unexplored. Recent reports have suggested that the pathological remodeling of vein grafts may be mediated by mechanically-induced activation of the mitogen activated protein kinase (MAPK) signaling pathways and the MAPK-related induction of caspase-3 activity. On the basis of these findings, we hypothesized that diabetes may be associated with alterations in how veins "sense" and "respond" to altered mechanical loading. Methods Inferior venae cavae (IVC) from the non-diabetic lean (LNZ) and the diabetic obese (OSXZ) Zucker rats were isolated and incubated ex vivo under basal or pressurized conditions (120 mmHg). Protein expression, basal activation and the ability of increased pressure to activate MAPK pathways and apoptosis-related signaling was evaluated by immunoblot analysis. Results Immunoblot analyses revealed differential expression and activation of extracellular signal-regulated kinase (ERK1/2), p38 and c-Jun NH2-terminal kinase (JNK) MAPKs in the IVCs of diabetic rats as compared to non-diabetic rats. In particular, the expression and basal phosphorylation of p38β- (52.3 ± 11.8%; 45.8 ± 18.2%), JNK 1- (21.5 ± 9.3%; 19.4 ± 11.6%) and JNK3-MAPK (16.8 ± 3.3%; 29.5 ± 17.6%) were significantly higher (P < 0.05) in the diabetic vena cava. An acute increase in IVC intraluminal pressure failed to increase the phosphorylation of ERK1-, JNK-2, or any of the p38-MAPKs in the diabetic obese Zucker rats. Also, IVC loading in the LNZ led to a 276.0 ± 36.0% and 85.8 ± 25.1% (P < 0.05) increase in the cleavage of caspase-3 and caspase-9, respectively, with no effect on these molecules in the OSXZ. No differences were found in the regulation of Bax and Bcl-2 between groups. However, basal expression levels of Akt, phospho-Akt, PTEN, phospho-PTEN and phospho-Bad were higher in the diabetic venae cavae (P < 0.05). Conclusion These data suggest that diabetes is associated with significant alteration in the ability of the vena cava to activate MAPK- and apoptosis-related signaling. Whether these changes are associated with the increased vein graft attrition seen in the diabetic population will require further investigation.
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Affiliation(s)
- Kevin M Rice
- Department of Pharmacology, Physiology and Toxicology, Joan C. Edwards School of Medicine, Marshall University, Huntington, WV, USA
- Department of Biological Sciences, Marshall University, Huntington, WV, USA
| | - Devashish H Desai
- Department of Pharmacology, Physiology and Toxicology, Joan C. Edwards School of Medicine, Marshall University, Huntington, WV, USA
| | - Sunil K Kakarla
- Department of Biological Sciences, Marshall University, Huntington, WV, USA
| | - Anjaiah Katta
- Department of Biological Sciences, Marshall University, Huntington, WV, USA
| | - Deborah L Preston
- Department of Biological Sciences, Marshall University, Huntington, WV, USA
| | - Paulette Wehner
- Department of Cardiology, Joan C. Edwards School of Medicine, Marshall University, Huntington, WV, USA
| | - Eric R Blough
- Department of Pharmacology, Physiology and Toxicology, Joan C. Edwards School of Medicine, Marshall University, Huntington, WV, USA
- Department of Biological Sciences, Marshall University, Huntington, WV, USA
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Zhang QG, Wang XT, Han D, Yin XH, Zhang GY, Xu TL. Akt inhibits MLK3/JNK3 signaling by inactivating Rac1: a protective mechanism against ischemic brain injury. J Neurochem 2006; 98:1886-98. [PMID: 16831194 DOI: 10.1111/j.1471-4159.2006.04020.x] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
The overall goal of this study was to determine the molecular basis by which mixed-lineage kinase 3 (MLK3) kinase and its signaling pathways are negatively regulated by the pro-survival Akt pathway in cerebral ischemia. We demonstrated that tyrosine phosphorylation of the phosphatase and tensin homolog deleted on chromosome 10 (PTEN) underlies the increased Akt-Ser473 phosphorylation by orthovanadate. Co-immunoprecipitation analysis revealed that endogenous Akt physically interacts with Rac1 in the hippocampal CA1 region, and this interaction is promoted on tyrosine phosphatase inhibition. The elevated Akt activation can deactivate MLK3 by phosphorylation at the Ser71 residue of Rac1, a small Rho family of guanidine triphosphatases required for MLK3 autophosphorylation. Subsequently, inhibition of c-Jun N-terminal kinase 3 (JNK3) results in decreased serine phosphorylation of 14-3-3, a cytoplasmic anchor of Bax, and prevents ischemia-induced mitochondrial translocation of Bax, release of cytochrome c and activation of caspase 3. At the same time, the expression of Fas-ligand decreases in the CA1 region after inhibition of c-Jun activation. The neuroprotective effect of Akt activation is significant in the CA1 region after global cerebral ischemia. Our results suggest that the activation of the pro-apoptotic MLK3/JNK3 cascade induced by ischemic stress can be suppressed through activation of the anti-apoptotic phosphatidylinositol 3-kinase/Akt pathway, which provides a direct link between Akt and the family of stress-activated kinases.
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Affiliation(s)
- Quan-Guang Zhang
- Department of Neurobiology and Biophysics, University of Science and Technology of China, Hefei, Anhui, China
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Lee SY, Kang EJ, Hur GY, Jung KH, Jung HC, Lee SY, Kim JH, Shin C, In KH, Kang KH, Yoo SH, Shim JJ. Peroxisome proliferator-activated receptor-γ inhibits cigarette smoke solution-induced mucin production in human airway epithelial (NCI-H292) cells. Am J Physiol Lung Cell Mol Physiol 2006; 291:L84-90. [PMID: 16443643 DOI: 10.1152/ajplung.00388.2005] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
The main etiologic factor for chronic bronchitis is cigarette smoke. Exposure to cigarette smoke is reported to induce goblet cell hyperplasia and mucus production. Mucin synthesis in airways has been reported to be regulated by the EGFR system. Peroxisome proliferator-activated receptor-γ (PPAR-γ) is a member of the ligand-activated nuclear receptor superfamily. PPAR-γ is implicated in anti-inflammatory responses, but mechanisms underlying these varied roles remain ill-defined. Recently, reports have shown that upregulation of phosphatase and tensin homolog deleted on chromosome 10 (PTEN) might be one of the mechanisms through which PPAR-γ agonists exert their anti-inflammatory actions. However, no data are available on the role of PPAR-γ in smoke-induced mucin production. In this study, we investigated the effect of PPAR-γ agonist (rosiglitazone) on smoke-induced mucin production in NCI-H292 cells. Exposure to cigarette smoke causes a significant decrease in PTEN expression and increases dose-dependent EGFR-specific tyrosine phosphorylation, resulting in MUC5AC mucin production in NCI-H292 cells. PPAR-γ agonists or specific inhibitors of phosphoinositide 3-kinase exert inhibition of cigarette smoke-induced mucin production, with the upregulation of PTEN signaling and downregulation of Akt expression. This study demonstrates that PPAR-γ agonist functions as a regulator of epithelial cell inflammation that may result in reduction of mucin-producing cells in airway epithelium.
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Affiliation(s)
- Sung Yong Lee
- Dept. of Internal Medicine, Korea Univ. Guro Hospital, #80, Guro-dong, Guro-gu, Seoul, Republic of Korea
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41
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Bastian P, Posch B, Lang K, Niggemann B, Zaenker KS, Hatt H, Entschladen F. Phosphatidylinositol 3-Kinase in the G Protein-Coupled Receptor–Induced Chemokinesis and Chemotaxis of MDA-MB-468 Breast Carcinoma Cells: A Comparison with Leukocytes. Mol Cancer Res 2006; 4:411-21. [PMID: 16778088 DOI: 10.1158/1541-7786.mcr-06-0030] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The polarization of tumor cells and leukocytes into a front end and a rear end is a crucial prerequisite for their autonomous, directed movement. Phosphatidylinositol 3-kinase (PI3K) is assumed to play an important role in this polarization process, whereas the results obtained with different cell types and different migration assays widely vary. Thus, we conducted a comparative study on the role of the PI3K in the locomotor activity and directionality of the migration of tumor cells on the example of MDA-MB-468 breast carcinoma cells in comparison with CTLs and neutrophil granulocytes. We used our well-established, collagen-based, three-dimensional migration assay for the investigation of the chemokinesis and chemotaxis of these cells. Our results show that the role of the PI3K in the regulation of migratory activity is distinct between the investigated cell types: the migration of CTLs and MDA-MB-468 cells was impaired by the inhibition of the PI3K with wortmannin, whereas neutrophil granulocytes were only slightly affected. However, neither cell type was impaired in the ability to respond chemotactically to gradients of ligands to G protein-coupled receptors. Thus, the PI3K contributes to the regulation of migratory activity but not to the directionality of migration of MDA-MB-468 breast carcinoma cells. As a further conclusion with regard to cancer treatment, the PI3K is not a suitable target for the inhibition of metastasis formation, because the migration of leukocytes is also affected, which leads to a dysfunction of the immune defense.
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Affiliation(s)
- Philipp Bastian
- Institute of Immunology, Witten/Herdecke University, Stockumer Str. 10, 58448 Witten, Germany
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Li YL, Tian Z, Wu DY, Fu BY, Xin Y. Loss of heterozygosity on 10q23.3 and mutation of tumor suppressor gene PTEN in gastric cancer and precancerous lesions. World J Gastroenterol 2005; 11:285-8. [PMID: 15633233 PMCID: PMC4205419 DOI: 10.3748/wjg.v11.i2.285] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.1] [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 loss of heterozygosity (LOH) and mutation of tumor suppressor gene PTEN in gastric cancer and precancerous lesions.
METHODS: Thirty cases of normal gastric mucosa, advanced and early stage gastric cancer, intestinal metaplasia, atrophic gastritis, and atypical hyperplasia were analyzed for PTEN LOH and mutations within the entire coding region of PTEN gene by PCR-SSCP denaturing PAGE gel electrophoresis, and PTEN mutation was detected by PCR-SSCP sequencing followed by silver staining.
RESULTS: LOH rate found in respectively atrophic gastritis was 10% (3/30), intestinal metaplasia 10% (3/30), atypical hyperplasia 13.3% (4/30), early stage gastric cancer 20% (6/30), and advanced stage gastric cancer 33.3% (9/30), None of the precancerous lesions and early stage gastric cancer showed PTEN mutations, but 10% (3/30) of the advanced stage gastric cancers, which were all positive for LOH, showed PTEN mutation.
CONCLUSION: LOH of PTEN gene appears in precancerous lesions, and PTEN mutations are restricted to advanced gastric cancer, LOH and mutation of PTEN gene are closely related to the infiltration and metastasis of gastric cancer.
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Affiliation(s)
- Yi-Ling Li
- Department of Gastroenterology, First Hospital of China Medical University, Shenyang 110001, Liaoning Province, China
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