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Yang CF, Yang GD, Huang TJ, Li R, Chu QQ, Xu L, Wang MS, Cai MD, Zhong L, Wei HJ, Huang HB, Huang JL, Qian CN, Huang BJ. EB-virus latent membrane protein 1 potentiates the stemness of nasopharyngeal carcinoma via preferential activation of PI3K/AKT pathway by a positive feedback loop. Oncogene 2015; 35:3419-31. [PMID: 26568302 DOI: 10.1038/onc.2015.402] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Revised: 08/28/2015] [Accepted: 09/05/2015] [Indexed: 12/24/2022]
Abstract
Our previous study reported that Epstein-Barr virus(EBV)-encoded latent membrane protein 1 (LMP1) could induce development of CD44(+/High) stem-like cells in nasopharyngeal carcinoma (NPC). However, the molecular mechanisms that underlie modulation of cancer stem cells (CSCs) in NPC remain unclear. Here, we show that LMP1 induced CSC-like properties through promotion of the expression of epithelial-mesenchymal transition-like cellular markers and through alterations in differentiation markers. Furthermore, LMP1 activated and triggered phosphoinositide 3-kinase/protein kinase B (PI3K/AKT) pathway, which subsequently stimulated expression of CSC markers, development of side population and tumor sphere formation. This suggests that PI3K/AKT pathway has an important role in the induction and maintenance of CSC properties in NPC. Similarly, PI3K/AKT pathway was also activated by phosphorylase in LMP1-induced CD44(+/High) cells. In addition, LMP1 greatly increased expression of miR-21 and downregulated expression of the miR-21 target, PTEN. Overexpression of miR-21 by transfection of miR-21 mimics into LMP1-transformed cells led to phosphorylase-mediated activation of the PI3K/AKT pathway and induction of CSCs. On the contrary, phosphorylation of the PI3K/AKT pathway and the expression of CSC were reversed by an miR-21 inhibitor. The specific inhibitor (Ly294002) of PI3K/AKT pathway significantly decreased expression of miR-21 and CSC markers and upregulated the expression of PTEN, which indicates that miR-21 and PTEN are the downstream effectors of PI3K/AKT and that expression of these two effectors are related to the development of NPC CSCs. Taken together, our novel findings indicate that LMP1, PI3K/AKT, miR-21 and PTEN constitute a positive feedback loop and have a key role in LMP1-induced CSCs in NPC.
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Affiliation(s)
- C-F Yang
- Department of Experimental Research, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-Sen University Cancer Center, Guangzhou China.,Department of Cancer Chemotherapy, Gaozhou People's Hospital, Gaozhou, China
| | - G-D Yang
- Department of Cancer Chemotherapy, Zengcheng People's Hospital (BoJi-Affiliated Hospital of Sun Yat-Sen University), Zengcheng, China
| | - T-J Huang
- Department of Nuclear Medicine, The Second People's Hospital of Shenzhen, Shenzhen, China
| | - R Li
- Second College of Clinical Medicine, Southern Medical University, Guangzhou, China
| | - Q-Q Chu
- School of Pharmaceutical Sciences, Sun Yat-Sen University, Guangzhou, China
| | - L Xu
- Department of Experimental Research, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-Sen University Cancer Center, Guangzhou China
| | - M-S Wang
- Department of Cancer Chemotherapy, Gaozhou People's Hospital, Gaozhou, China
| | - M-D Cai
- Department of Cancer Chemotherapy, Gaozhou People's Hospital, Gaozhou, China
| | - L Zhong
- Department of Cancer Chemotherapy, Gaozhou People's Hospital, Gaozhou, China
| | - H-J Wei
- Department of Cancer Chemotherapy, Gaozhou People's Hospital, Gaozhou, China
| | - H-B Huang
- Department of Pharmacy, Sun Yat-Sen University Cancer Center, Guangzhou, China
| | - J-L Huang
- Department of Pathology, Saint Barnabas Medical Center, Livingston, NJ, USA
| | - C-N Qian
- Department of Experimental Research, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-Sen University Cancer Center, Guangzhou China.,Department of Nasopharyngeal Carcinoma, Sun Yat-Sen University Cancer Center, Guangzhou, China
| | - B-J Huang
- Department of Experimental Research, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-Sen University Cancer Center, Guangzhou China
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Ooft ML, Braunius WW, Heus P, Stegeman I, van Diest PJ, Grolman W, Zuur CI, Willems SM. Prognostic significance of the EGFR pathway in nasopharyngeal carcinoma: a systematic review and meta-analysis. Biomark Med 2015; 9:997-1010. [PMID: 26441207 DOI: 10.2217/bmm.15.68] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
OBJECTIVE To evaluate the prognostic impact of the EGF receptor (EGFR) pathway molecules and assess their clinical usefulness. METHODS We conducted a systematic review. Pubmed and EMBASE were searched January 2014. The prognostic relevance of EGFR, JAK, PI3K, PIK3CA, STAT3, STAT5, PTEN, AKT, mTOR, GRB2, SOS, RAF, RAS, MAPK, ERK, MEK and CCND1 in nasopharyngeal carcinoma was assessed. The outcomes considered were overall survival, disease-free survival and tumor-node-metastasis stage. Twenty-two studies were included. Risk of bias was evaluated. Meta-analysis for which pooled hazard ratios and 95% CIs were calculated. CONCLUSION EGFR overexpression predicts a worse overall survival and disease-free survival in nasopharyngeal carcinoma, but no specific causal pathway molecule could be identified.
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Affiliation(s)
- Marc L Ooft
- Department of Pathology, University Medical Center, Utrecht, The Netherlands
| | - Weibel W Braunius
- Department of Otolaryngology, University Medical Center, Utrecht, The Netherlands
| | - Paulien Heus
- Dutch Cochrane Center, Julius Center for Health Sciences & Primary Care, University Medical Center, Utrecht, The Netherlands
| | - Inge Stegeman
- Department of Otolaryngology, University Medical Center, Utrecht, The Netherlands
| | - Paul J van Diest
- Department of Pathology, University Medical Center, Utrecht, The Netherlands
| | - Wilko Grolman
- Department of Otolaryngology, University Medical Center, Utrecht, The Netherlands
| | - Charlotte I Zuur
- Department of Head & Neck Surgery & Oncology, Netherlands Cancer Institute, Amsterdam, The Netherlands
| | - Stefan M Willems
- Department of Pathology, University Medical Center, Utrecht, The Netherlands
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53
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Ying J, Xu Q, Liu B, Zhang G, Chen L, Pan H. The expression of the PI3K/AKT/mTOR pathway in gastric cancer and its role in gastric cancer prognosis. Onco Targets Ther 2015; 8:2427-33. [PMID: 26366097 PMCID: PMC4562727 DOI: 10.2147/ott.s88592] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Objective To analyze the correlation between sequential aspects of the phosphoinositide-3 kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) pathway by immunohistochemistry in the primary lesion of gastric cancer, clinicopathologic factors, and survival in Chinese patients to explore the role of sequential analysis of multiple targets in prognoses. Methods Immunohistochemistry was performed to examine the expression of PI3K, phosphorylated-AKT (p-AKT), and phosphorylated-mTOR (p-mTOR) in 59 primary lesion samples ranging from Stages I to IV after gastrectomy. The correlation between sequential expression of multiple targets, and clinicopathologic factors and survival was analyzed. Results The positive expression rates of PI3K, p-AKT, and p-mTOR were 49%, 58%, and 56%, respectively. There were eleven cases with three biomarkers positive (19%), 22 cases with two biomarkers positive (37%), and 19 cases with only one biomarker positive (32%). Seven cases (12%) were all negative. Multi-factorial Cox regression analysis showed that neural invasion, vascular invasion, size of the tumor, lymph nodes affected, metastasis, carbohydrate antigen 19-9 level, and PI3K/p-AKT/p-mTOR simultaneous expression were independent prognostic parameters. The risk of death for the cases with two biomarkers positive was 0.367 times that for the cases with three biomarkers positive (P=0.166). The risk of death for the cases with only one biomarker positive was 0.105 times that for the cases with three biomarkers positive (P=0.058). The risk of death for the cases with three biomarkers negative was 0.017 times that for the cases with three biomarkers positive (P=0.022). Conclusion Our study generated the hypothesis that patients with gastric cancer with simultaneous expression of PI3K/p-AKT/p-mTOR had worse outcome. But we need more rigorous validation in a larger data set.
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Affiliation(s)
- Jieer Ying
- Department of Chemotherapy,Sir Run Run Shaw Hospital, College of Medicine, Zhejiang University, Zhejiang, People's Republic of China ; Department of Chemotherapy, Zhejiang Cancer Hospital, Hangzhou, Zhejiang, People's Republic of China
| | - Qi Xu
- Department of Chemotherapy, Zhejiang Cancer Hospital, Hangzhou, Zhejiang, People's Republic of China
| | - Bixia Liu
- Department of Chemotherapy, Zhejiang Cancer Hospital, Hangzhou, Zhejiang, People's Republic of China
| | - Gu Zhang
- Department of Pathology, Zhejiang Cancer Hospital, Hangzhou, Zhejiang, People's Republic of China
| | - Lei Chen
- Department of Chemotherapy, Zhejiang Cancer Hospital, Hangzhou, Zhejiang, People's Republic of China
| | - Hongming Pan
- Department of Chemotherapy,Sir Run Run Shaw Hospital, College of Medicine, Zhejiang University, Zhejiang, People's Republic of China
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Abe H, Kaneda A, Fukayama M. Epstein-Barr Virus-Associated Gastric Carcinoma: Use of Host Cell Machineries and Somatic Gene Mutations. Pathobiology 2015; 82:212-23. [DOI: 10.1159/000434683] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2015] [Accepted: 05/27/2015] [Indexed: 11/19/2022] Open
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Cardioprotection by PI3K-mediated signaling is required for anti-arrhythmia and myocardial repair in response to ischemic preconditioning in infarcted pig hearts. J Transl Med 2015; 95:860-71. [PMID: 26006021 DOI: 10.1038/labinvest.2015.64] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2014] [Revised: 03/18/2015] [Accepted: 03/19/2015] [Indexed: 11/08/2022] Open
Abstract
Although the phosphatidyl-inositol-3-kinase (PI3K)/Akt pathway is essential for conferring cardioprotection in response to ischemic preconditioning (IP), the role of PI3K/Akt signaling in the infarcted heart for mediating the anti-arrhythmic effects in response to IP remains unclear. We explored the involvement of PI3K/Akt in the IP-like effect of connexin 43 and proangiogenic factors with particular regard to its role in protecting against ischemia-induced arrhythmia, heart failure, and myocardial remodeling. Groups of pigs were administered phosphate-buffered saline (PBS) or LY294002 solution. Before induction of myocardial infarction (MI), pigs were grouped according to whether or not they underwent IP. Next, all animals underwent MI induction by ligation of the left anterior descending (LAD) coronary artery. Myocardial tissues from the pig hearts at 7 days after MI were used to assess myocardium myeloperoxidase and reaction oxygen species, infarct size, collagen content, blood vascular density, expression of Akt, connexin 43, and proangiogenic growth factors, using spectrophotometer, histology, immunohistochemistry, real-time RT-PCR, and western blot. At 7 days after MI, IP significantly reduced animal mortality and malignant ventricular arrhythmia, myocardial inflammation, infarct size, and collagen content, and improved cardiac function and remodeling; use of the PI3K inhibitor LY294002 diminished these effects. In parallel with a decline in Akt expression and phosphorylation by MI, LY294002 injection resulted in significant suppression of connexin 43 and proangiogenic factor expression, and a reduction of angiogenesis and collateral circulation. These findings demonstrate that the cardioprotective effects of IP on antiventricular arrhythmia and myocardial repair occur through upregulation of PI3K/Akt-mediated connexin 43 and growth factor signaling.
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Bo QF, Sun XM, Liu J, Sui XM, Li GX. Antitumor action of the peroxisome proliferator-activated receptor-γ agonist rosiglitazone in hepatocellular carcinoma. Oncol Lett 2015; 10:1979-1984. [PMID: 26622783 PMCID: PMC4579902 DOI: 10.3892/ol.2015.3554] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2014] [Accepted: 03/02/2015] [Indexed: 12/15/2022] Open
Abstract
The inhibition of apoptosis in cancer cells is the major pathological feature of hepatic carcinoma. Rosiglitazone (RGZ), a ligand for peroxisome proliferator-activated receptor γ (PPAR-γ), has been shown to induce apoptosis in hepatic carcinoma cells. However, the mechanism underlying this effect remains to be elucidated. The present study aimed to investigate the effect of RGZ on cell viability and apoptosis, and its mechanisms in cultured HepG2 cells using MTT assay, flow cytometry and western blotting. The results revealed that treatment with RGZ may attenuate HepG2 cell viability and induce the apoptosis of the cells. The mechanism of RGZ-induced apoptosis involves an increase in the level of activated PPAR-γ (p-PPAR-γ) and a decrease in p85 and Akt expression. In addition, the PPAR-γ antagonist GW9662 suppressed the effect of RGZ in the HepG2 cells. Taken together, the results suggest that RGZ induces the apoptosis of HepG2 cells through the activation of PPAR-γ, suppressing the activation of the PI3K/Akt signaling pathway. Such mechanisms may contribute to the favorable effects of treatment using RGZ in HepG2 cells.
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Affiliation(s)
- Qi-Fu Bo
- Department of Oncology, Affiliated Hospital of Weifang Medical University, Weifang, Shandong 261000, P.R. China
| | - Xiu-Mei Sun
- Department of Oncology, Affiliated Hospital of Weifang Medical University, Weifang, Shandong 261000, P.R. China
| | - Jin Liu
- Department of Oncology, Affiliated Hospital of Weifang Medical University, Weifang, Shandong 261000, P.R. China
| | - Xiao-Mei Sui
- Department of Oncology, Affiliated Hospital of Weifang Medical University, Weifang, Shandong 261000, P.R. China
| | - Gui-Xin Li
- Department of Oncology, Affiliated Hospital of Weifang Medical University, Weifang, Shandong 261000, P.R. China
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Liu J, Huang W, Ren C, Wen Q, Liu W, Yang X, Wang L, Zhu B, Zeng L, Feng X, Zhang C, Chen H, Jia W, Zhang L, Xia X, Chen Y. Flotillin-2 promotes metastasis of nasopharyngeal carcinoma by activating NF-κB and PI3K/Akt3 signaling pathways. Sci Rep 2015. [PMID: 26206082 PMCID: PMC4648439 DOI: 10.1038/srep11614] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Lipid raft proteins have been confirmed to be important in cell signal transduction. Some reports have shown that the aberrant expression of lipid raft proteins is associated with malignant phenotypes in some cancers. However, the role of the lipid raft protein flotillin-2 (Flot-2) in nasopharyngeal carcinoma (NPC) remains to be comprehensively characterized. Here, overexpression of Flot-2 in NPC tissues and cell lines was detected by immunostaining, and Flot-2 expression was found to be positively associated with NPC metastasis. Furthermore, inhibiting Flot-2 expression impaired the malignancy of the highly metastatic NPC cell line 5-8F by constraining its growth and proliferation, mobility and migration, and decreasing the capacity of 5-8F cells to metastasize in nude mice. In contrast, forced overexpression of Flot-2 increased the malignancy of 6-10B, a non-metastatic NPC cell line that weakly expresses Flot-2. Moreover, in 5-8F-shFlot-2 cells, which have inhibited Flot-2 expression, the NF-κB and PI3K/Akt3 pathways were inactivated. Subsequently, MMPs expression were decreased, and Foxo1 activity was increased. In addition, enhanced NF-κB and PI3K/Akt3 activities were observed in Flot-2 overexpressing 6-10B cells. Thus, Flot-2 exerts a pro-neoplastic role in NPC and is involved in tumor progression and metastasis. Moreover, Flot-2 exerts its role through NF-κB and PI3K/Akt3 signaling.
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Affiliation(s)
- Jie Liu
- Cancer Research Institute, Collaborative Innovation Center for Cancer Medicine, Key Laboratory for Carcinogenesis of Chinese Ministry of Health, School of Basic Medical Science, Central South University, Xiangya Road 110, 410078, Changsha, Hunan, P. R. China
| | - Wei Huang
- Cancer Research Institute, Collaborative Innovation Center for Cancer Medicine, Key Laboratory for Carcinogenesis of Chinese Ministry of Health, School of Basic Medical Science, Central South University, Xiangya Road 110, 410078, Changsha, Hunan, P. R. China
| | - Caiping Ren
- Cancer Research Institute, Collaborative Innovation Center for Cancer Medicine, Key Laboratory for Carcinogenesis of Chinese Ministry of Health, School of Basic Medical Science, Central South University, Xiangya Road 110, 410078, Changsha, Hunan, P. R. China
| | - Qiuyuan Wen
- Cancer Research Institute, Collaborative Innovation Center for Cancer Medicine, Key Laboratory for Carcinogenesis of Chinese Ministry of Health, School of Basic Medical Science, Central South University, Xiangya Road 110, 410078, Changsha, Hunan, P. R. China
| | - Weidong Liu
- Cancer Research Institute, Collaborative Innovation Center for Cancer Medicine, Key Laboratory for Carcinogenesis of Chinese Ministry of Health, School of Basic Medical Science, Central South University, Xiangya Road 110, 410078, Changsha, Hunan, P. R. China
| | - Xuyu Yang
- Cancer Research Institute, Collaborative Innovation Center for Cancer Medicine, Key Laboratory for Carcinogenesis of Chinese Ministry of Health, School of Basic Medical Science, Central South University, Xiangya Road 110, 410078, Changsha, Hunan, P. R. China
| | - Lei Wang
- Cancer Research Institute, Collaborative Innovation Center for Cancer Medicine, Key Laboratory for Carcinogenesis of Chinese Ministry of Health, School of Basic Medical Science, Central South University, Xiangya Road 110, 410078, Changsha, Hunan, P. R. China
| | - Bin Zhu
- Cancer Research Institute, Collaborative Innovation Center for Cancer Medicine, Key Laboratory for Carcinogenesis of Chinese Ministry of Health, School of Basic Medical Science, Central South University, Xiangya Road 110, 410078, Changsha, Hunan, P. R. China
| | - Liang Zeng
- Department of Pathology, Hunan Cancer Hospital, Changsha, Hunan, P. R. China
| | - Xiangling Feng
- Cancer Research Institute, Collaborative Innovation Center for Cancer Medicine, Key Laboratory for Carcinogenesis of Chinese Ministry of Health, School of Basic Medical Science, Central South University, Xiangya Road 110, 410078, Changsha, Hunan, P. R. China
| | - Chang Zhang
- Cancer Research Institute, Collaborative Innovation Center for Cancer Medicine, Key Laboratory for Carcinogenesis of Chinese Ministry of Health, School of Basic Medical Science, Central South University, Xiangya Road 110, 410078, Changsha, Hunan, P. R. China
| | - Huan Chen
- Cancer Research Institute, Collaborative Innovation Center for Cancer Medicine, Key Laboratory for Carcinogenesis of Chinese Ministry of Health, School of Basic Medical Science, Central South University, Xiangya Road 110, 410078, Changsha, Hunan, P. R. China
| | - Wei Jia
- Cancer Research Institute, Collaborative Innovation Center for Cancer Medicine, Key Laboratory for Carcinogenesis of Chinese Ministry of Health, School of Basic Medical Science, Central South University, Xiangya Road 110, 410078, Changsha, Hunan, P. R. China
| | - Lihua Zhang
- Cancer Research Institute, Collaborative Innovation Center for Cancer Medicine, Key Laboratory for Carcinogenesis of Chinese Ministry of Health, School of Basic Medical Science, Central South University, Xiangya Road 110, 410078, Changsha, Hunan, P. R. China
| | - Xiaomeng Xia
- Department of Gynaecology and Obstetrics, The Second Xiangya Hospital, Central South University, Changsha, Hunan, P. R. China
| | - Yuxiang Chen
- Hepatobiliary &Enteric Surgery Research Center, Xiangya Hospital, Central South University, Changsha, Hunan, P. R. China
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Molecular classification of gastric adenocarcinoma: translating new insights from the cancer genome atlas research network. Curr Treat Options Oncol 2015; 16:17. [PMID: 25813036 DOI: 10.1007/s11864-015-0331-y] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Gastric cancer is a heterogenous cancer, which may be classified into several distinct subtypes based on pathology and epidemiology, each with different initiating pathological processes and each possibly having different tumor biology. A classification of gastric cancer should be important to select patients who can benefit from the targeted therapies or to precisely predict prognosis. The Cancer Genome Atlas (TCGA) study collaborated with previous reports regarding subtyping gastric cancer but also proposed a refined classification based on molecular characteristics. The addition of the new molecular classification strategy to a current classical subtyping may be a promising option, particularly stratification by Epstein-Barr virus (EBV) and microsatellite instability (MSI) statuses. According to TCGA study, EBV gastric cancer patients may benefit the programmed cell death protein 1 (PD-1)/programmed death-ligand 1 (PD-L1) antibodies or phosphoinositide 3-kinase (PI3K) inhibitors which are now being developed. The discoveries of predictive biomarkers should improve patient care and individualized medicine in the management since the targeted therapies may have the potential to change the landscape of gastric cancer treatment, moreover leading to both better understanding of the heterogeneity and better outcomes. Patient enrichment by predictive biomarkers for new treatment strategies will be critical to improve clinical outcomes. Additionally, liquid biopsies will be able to enable us to monitor in real-time molecular escape mechanism, resulting in better treatment strategies.
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Choi E, Byeon SJ, Kim SH, Lee HJ, Kwon HJ, Ahn H, Kim DH, Chang MS. Implication of Leptin-Signaling Proteins and Epstein-Barr Virus in Gastric Carcinomas. PLoS One 2015; 10:e0130839. [PMID: 26147886 PMCID: PMC4493019 DOI: 10.1371/journal.pone.0130839] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2015] [Accepted: 05/26/2015] [Indexed: 02/07/2023] Open
Abstract
We investigated the clinicopathological implications of leptin-signaling proteins and Epstein-Barr virus (EBV)-infection status in gastric carcinomas. Immunohistochemistry for leptin signalling-related proteins (leptin, leptin-receptor, pSTAT3, ERK, pAkt, mTOR and HIF-1 alpha), and in situ hybridization for EBV-encoded small RNAs was performed in 343 cases of gastric carcinomas. The siRNA against leptin-receptor was transfected into three stomach cancer cell lines, and western blot for caspase 3 was performed. The TNM stage was a prognostic factor in all 343 patients, and was negatively correlated with expression of leptin, pSTAT3, ERK, pAkt, mTOR and HIF-1 alpha (P < 0.05). Leptin-receptor expression was correlated with poor survival in 207 patients of the advanced gastric cancer (AGC) subgroup, 139 of the Lauren diffuse group, and in 160 patients with lymph node metastasis (P < 0.05, respectively). Additionally, in stomach cancer cells, cleaved caspase 3 level increased by leptin-receptor inhibition, that is, apoptosis increased. Interestingly, EBV-positive AGC (n = 29) tended to show better survival of patients than EBV-negative AGC (n = 178) (P = 0.06). pAkt expression was related with a good survival of 32 patients (9%) in the EBV-positive subgroup, but was not an independent prognostic factor. Among, leptin signaling-related proteins, expressions of leptin-receptor and mTOR were different between EBV-positive subgroup and EBV-negative subgroup (P < 0.05, respectively). In conclusion, leptin-signaling proteins and EBV status show different significance on patient survival, according to subsets of gastric carcinomas. The leptin-receptor may predict poor patient prognosis in the AGC, Lauren diffuse and lymph node metastasis subgroups, while EBV-positive status can show a good prognosis in the AGC. Each leptin signaling-related protein may be differently involved in carcinogenesis of EBV-negative and EBV-positive subsets.
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Affiliation(s)
- Euno Choi
- Department of Pathology, Seoul National University Boramae Hospital, Seoul National University College of Medicine, Seoul, Korea
| | - Sun-ju Byeon
- Department of Surgery, Seoul National University Boramae Hospital, Seoul, Korea
| | - Soo Hee Kim
- Department of Pathology, Seoul National University Boramae Hospital, Seoul National University College of Medicine, Seoul, Korea
| | - Hyun Ju Lee
- Department of Pathology, Seoul National University Boramae Hospital, Seoul National University College of Medicine, Seoul, Korea
| | - Hyeong Ju Kwon
- Department of Pathology, Seoul National University Boramae Hospital, Seoul National University College of Medicine, Seoul, Korea
| | - HyeSeong Ahn
- Department of Surgery, Seoul National University Boramae Hospital, Seoul, Korea
| | - Dong Ha Kim
- Department of Pathology, Seoul National University Boramae Hospital, Seoul National University College of Medicine, Seoul, Korea
| | - Mee Soo Chang
- Department of Pathology, Seoul National University Boramae Hospital, Seoul National University College of Medicine, Seoul, Korea
- * E-mail:
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Liu X, Cohen JI. The role of PI3K/Akt in human herpesvirus infection: From the bench to the bedside. Virology 2015; 479-480:568-77. [PMID: 25798530 PMCID: PMC4424147 DOI: 10.1016/j.virol.2015.02.040] [Citation(s) in RCA: 72] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Revised: 02/17/2015] [Accepted: 02/18/2015] [Indexed: 12/25/2022]
Abstract
The phosphatidylinositol-3-kinase (PI3K)-Akt signaling pathway regulates several key cellular functions including protein synthesis, cell growth, glucose metabolism, and inflammation. Many viruses have evolved mechanisms to manipulate this signaling pathway to ensure successful virus replication. The human herpesviruses undergo both latent and lytic infection, but differ in cell tropism, growth kinetics, and disease manifestations. Herpesviruses express multiple proteins that target the PI3K/Akt cell signaling pathway during the course of their life cycle to facilitate viral infection, replication, latency, and reactivation. Rare human genetic disorders with mutations in either the catalytic or regulatory subunit of PI3K that result in constitutive activation of the protein predispose to severe herpesvirus infections as well as to virus-associated malignancies. Inhibiting the PI3K/Akt pathway or its downstream proteins using drugs already approved for other diseases can block herpesvirus lytic infection and may reduce malignancies associated with latent herpesvirus infections.
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Affiliation(s)
- XueQiao Liu
- Medical Virology Section, Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Jeffrey I Cohen
- Medical Virology Section, Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, 20892, USA.
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61
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Restricted protein phosphatase 2A targeting by Merkel cell polyomavirus small T antigen. J Virol 2015; 89:4191-200. [PMID: 25631078 DOI: 10.1128/jvi.00157-15] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
UNLABELLED Merkel cell polyomavirus (MCV) is a newly discovered human cancer virus encoding a small T (sT) oncoprotein. We performed MCV sT FLAG-affinity purification followed by mass spectroscopy (MS) analysis, which identified several protein phosphatases (PP), including PP2A A and C subunits and PP4C, as potential cellular interacting proteins. PP2A targeting is critical for the transforming properties of nonhuman polyomaviruses, such as simian virus 40 (SV40), but is not required for MCV sT-induced rodent cell transformation. We compared similarities and differences in PP2A binding between MCV and SV40 sT. While SV40 sT coimmunopurified with subunits PP2A Aα and PP2A C, MCV sT coimmunopurified with PP2A Aα, PP2A Aβ, and PP2A C. Scanning alanine mutagenesis at 29 sites across the MCV sT protein revealed that PP2A-binding domains lie on the opposite molecular surface from a previously described large T stabilization domain (LSD) loop that binds E3 ligases, such as Fbw7. MCV sT-PP2A interactions can be functionally distinguished by mutagenesis from MCV sT LSD-dependent 4E-BP1 hyperphosphorylation and viral DNA replication enhancement. MCV sT has a restricted range for PP2A B subunit substitution, inhibiting only the assembly of B56α into the phosphatase holoenzyme. In contrast, SV40 sT inhibits the assembly of B55α, B56α and B56ε into PP2A. We conclude that MCV sT is required for Merkel cell carcinoma growth, but its in vitro transforming activity depends on LSD interactions rather than PP2A targeting. IMPORTANCE Merkel cell polyomavirus is a newly discovered human cancer virus that promotes cancer, in part, through expression of its small T (sT) oncoprotein. Animal polyomavirus sT oncoproteins have been found to cause experimental tumors by blocking the activities of a group of phosphatases called protein phosphatase 2A (PP2A). Our structural analysis reveals that MCV sT also displaces the B subunit of PP2A to inhibit PP2A activity. MCV sT, however, only displaces a restricted subset of PP2A B subunits, which is insufficient to cause tumor cell formation in vitro. MCV sT instead transforms tumor cells through another region called the large T stabilization domain. The PP2A targeting and transforming activities lie on opposite faces of the MCV sT molecule and can be genetically separated from each other.
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Cai Q, Chen K, Young KH. Epstein-Barr virus-positive T/NK-cell lymphoproliferative disorders. Exp Mol Med 2015; 47:e133. [PMID: 25613730 PMCID: PMC4314580 DOI: 10.1038/emm.2014.105] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2014] [Accepted: 10/21/2014] [Indexed: 12/18/2022] Open
Abstract
Epstein–Barr virus, a ubiquitous human herpesvirus, can induce both lytic and latent infections that result in a variety of human diseases, including lymphoproliferative disorders. The oncogenic potential of Epstein–Barr virus is related to its ability to infect and transform B lymphocytes into continuously proliferating lymphoblastoid cells. However, Epstein–Barr virus has also been implicated in the development of T/natural killer cell lymphoproliferative diseases. Epstein–Barr virus encodes a series of products that mimic several growth, transcription and anti-apoptotic factors, thus usurping control of pathways that regulate diverse homeostatic cellular functions and the microenvironment. However, the exact mechanism by which Epstein–Barr virus promotes oncogenesis and inflammatory lesion development remains unclear. Epstein–Barr virus-associated T/natural killer cell lymphoproliferative diseases often have overlapping clinical symptoms as well as histologic and immunophenotypic features because both lymphoid cell types derive from a common precursor. Accurate classification of Epstein–Barr virus-associated T/natural killer cell lymphoproliferative diseases is a prerequisite for appropriate clinical management. Currently, the treatment of most T/natural killer cell lymphoproliferative diseases is less than satisfactory. Novel and targeted therapies are strongly required to satisfy clinical demands. This review describes our current knowledge of the genetics, oncogenesis, biology, diagnosis and treatment of Epstein–Barr virus-associated T/natural killer cell lymphoproliferative diseases.
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Affiliation(s)
- Qingqing Cai
- 1] Department of Medical Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center of Cancer Medicine, Guangzhou, China [2] Department of Hematopathology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Kailin Chen
- Department of Medical Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center of Cancer Medicine, Guangzhou, China
| | - Ken H Young
- 1] Department of Hematopathology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA [2] The University of Texas School of Medicine, Graduate School of Biomedical Sciences, Houston, TX, USA
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Yao Y, Xue Y, Ma J, Shang C, Wang P, Liu L, Liu W, Li Z, Qu S, Li Z, Liu Y. MiR-330-mediated regulation of SH3GL2 expression enhances malignant behaviors of glioblastoma stem cells by activating ERK and PI3K/AKT signaling pathways. PLoS One 2014; 9:e95060. [PMID: 24736727 PMCID: PMC3988141 DOI: 10.1371/journal.pone.0095060] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2013] [Accepted: 03/23/2014] [Indexed: 12/13/2022] Open
Abstract
MicroRNAs are currently considered as an active and rapidly evolving area for the treatment of tumors. In this study, we elucidated the biological significance of miR-330 in glioblastoma stem cells (GSCs) as well as the possible molecular mechanisms. SH3GL2 is mainly distributed in the central nervous system and considered to be a tumor suppressor in many tumors. In the present study, we identified miR-330 as a potential regulator of SH3GL2 and we found that it was to be inversely correlated with SH3GL2 expression in GSCs which were isolated from U87 cell lines. The expression of miR-330 enhanced cellular proliferation, promoted cell migration and invasion, and dampened cell apoptosis. When the GSCs were co-transfected with the plasmid containing short hairpin RNA directed against human SH3GL2 gene and miR-330 mimic, we found that miR-330 promoted the malignant behavior of GSCs by down-regulating the expression of SH3GL2. Meanwhile, the ERK and PI3K/AKT signaling pathways were significantly activated, leading to the decreased expression of apoptotic protein and increased expression of anti-apoptotic protein. Furthermore, in orthotopic mouse xenografts, the mice given stable over-expressed SH3GL2 cells co-transfected with miR-330 knockdown plasmid had the smallest tumor sizes and longest survival. In conclusion, these results suggested that miR-330 negatively regulated the expression of SH3GL2 in GSCs, which promoted the oncogenic progression of GSCs through activating ERK and PI3K/AKT signaling pathways. The elucidation of these mechanisms will provide potential therapeutic approaches for human glioblastoma.
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Affiliation(s)
- Yilong Yao
- Department of Neurosurgery, Shengjing Hospital of China Medical University, Shenyang, Liaoning Province, People’s Republic of China
| | - Yixue Xue
- Department of Neurobiology, College of Basic Medicine, China Medical University, Shenyang, Liaoning Province, People’s Republic of China
- Institute of Pathology and Pathophysiology, China Medical University, Shenyang, Liaoning Province, People’s Republic of China
| | - Jun Ma
- Department of Neurobiology, College of Basic Medicine, China Medical University, Shenyang, Liaoning Province, People’s Republic of China
- Institute of Pathology and Pathophysiology, China Medical University, Shenyang, Liaoning Province, People’s Republic of China
| | - Chao Shang
- Department of Neurobiology, College of Basic Medicine, China Medical University, Shenyang, Liaoning Province, People’s Republic of China
- Institute of Pathology and Pathophysiology, China Medical University, Shenyang, Liaoning Province, People’s Republic of China
| | - Ping Wang
- Department of Neurobiology, College of Basic Medicine, China Medical University, Shenyang, Liaoning Province, People’s Republic of China
- Institute of Pathology and Pathophysiology, China Medical University, Shenyang, Liaoning Province, People’s Republic of China
| | - Libo Liu
- Department of Neurobiology, College of Basic Medicine, China Medical University, Shenyang, Liaoning Province, People’s Republic of China
- Institute of Pathology and Pathophysiology, China Medical University, Shenyang, Liaoning Province, People’s Republic of China
| | - Wenjing Liu
- Department of Neurology, The First Affiliated Hospital, China Medical University, Shenyang, Liaoning Province, People’s Republic of China
| | - Zhen Li
- Department of Neurosurgery, Shengjing Hospital of China Medical University, Shenyang, Liaoning Province, People’s Republic of China
| | - Shengtao Qu
- Department of Neurosurgery, Shengjing Hospital of China Medical University, Shenyang, Liaoning Province, People’s Republic of China
| | - Zhiqing Li
- Department of Neurobiology, College of Basic Medicine, China Medical University, Shenyang, Liaoning Province, People’s Republic of China
| | - Yunhui Liu
- Department of Neurosurgery, Shengjing Hospital of China Medical University, Shenyang, Liaoning Province, People’s Republic of China
- * E-mail:
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