title: Reduction of microRNA-184 by E6 oncoprotein confers cisplatin resistance in lung cancer via increasing Bcl-2.
abstract: MicroRNA-184 suppresses cell growth and survival via targeting c-Myc and Bcl- 2. We recently reported that miR-184 promotes tumor progression in non-small cell lung cancer via targeting CDC25A and c-Myc. We here hypothesized that miR-184 could be down-regulated by E6 oncoprotein to confer cisplatin resistance in NSCLC. Human papillomavirus (HPV) 16-positive lung cancer TL-1 and cervical cancer SiHa cells compared with HPV16-negative TL-10 and C33A cells were enrolled for E6 manipulation. MiR-184 expression levels were increased by E6-knockdown in TL-1 and SiHa cells, but decreased by E6-overexpression in TL-10 and C33A cells. The MTT assay showed that the inhibition concentration of cisplatin yielding for 50% cell viability was dependent on miR-184 levels. Bcl-2 de-targeted by E6-mediated miR- 184 reduction was responsible for cisplatin resistance. Luciferase reporter assay and real- time PCR analysis indicated that the miR-184 promoter activity and its expression were modulated by E6 and/or p53 manipulation. Chromatin immunoprecipitation (ChIP) assay confirmed that p53 was bound onto the miR-184 promoter and its binding activity was modulated by E6 and/or p53 manipulation. Among patients, high miR184 and high Bcl-2 mRNA expression was more commonly occurred in E6- positive tumors than in E6-negative tumors. Fifty-nine out of 136 patients receiving cisplatin-based chemotherapy were available for the retrospective study. Patients with low-mR-184, E6-positive, high-Bcl-2 tumors, and both combinations were more prevalently occurred unfavorable response to cisplatin-based chemotherapy than their counterparts. In conclusion, a decrease in miR-184 level by E6 oncoprotein may predict unfavorable response to cisplatin-based chemotherapy in HPV-infected NSCLC patients via increasing Bcl-2 expression.
authors.affiliation: Graduate Institute of Clinical Medicine, Taipei Medical University, Taipei, Taiwan.|Department of Surgery, Tung's Taichung Metro-Harbor Hospital, Taichung, Taiwan.
authors.forename: Min-Che
authors.initials: MC
authors.lastname: Tung
authors.affiliation: Institute of Medicine, Chung Shan Medical University, Taichung, Taiwan.
authors.forename: Po-Lin
authors.initials: PL
authors.lastname: Lin
authors.affiliation: Graduate Institute of Cancer Biology and Drug Discovery, Taipei Medical University, Taipei, Taiwan.
authors.forename: Ya-Wen
authors.initials: YW
authors.lastname: Cheng
authors.affiliation: Graduate Institute of Cancer Biology and Drug Discovery, Taipei Medical University, Taipei, Taiwan.
authors.forename: De-Wei
authors.initials: DW
authors.lastname: Wu
authors.affiliation: Graduate Institute of Clinical Medicine, Taipei Medical University, Taipei, Taiwan.
authors.forename: Sauh-Der
authors.initials: SD
authors.lastname: Yeh
authors.affiliation: Department of Surgery, Chung Shan Medical University, Taichung, Taiwan.
authors.forename: Chi-Yi
authors.initials: CY
authors.lastname: Chen
authors.affiliation: Graduate Institute of Cancer Biology and Drug Discovery, Taipei Medical University, Taipei, Taiwan.
authors.forename: Huei
authors.initials: H
authors.lastname: Lee
mesh_terms: D000970:Antineoplastic Agents / Q000627:therapeutic use*; D001665:Binding Sites; D002289:Carcinoma, Non-Small-Cell Lung / Q000188:drug therapy* / Q000235:genetics / Q000378:metabolism / Q000821:virology; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D002945:Cisplatin / Q000627:therapeutic use*; D004305:Dose-Response Relationship, Drug; D019008:Drug Resistance, Neoplasm; D015972:Gene Expression Regulation, Neoplastic; D052162:Human papillomavirus 16 / Q000235:genetics / Q000378:metabolism* / Q000472:pathogenicity; D006801:Humans; D008175:Lung Neoplasms / Q000188:drug therapy* / Q000235:genetics / Q000378:metabolism / Q000821:virology; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism*; D009856:Oncogene Proteins, Viral / Q000235:genetics / Q000378:metabolism*; D030361:Papillomavirus Infections / Q000378:metabolism* / Q000821:virology; D011401:Promoter Regions, Genetic; D059748:Proteolysis; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics / Q000378:metabolism*; D034622:RNA Interference; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism*; D012189:Retrospective Studies; D012307:Risk Factors; D015398:Signal Transduction / Q000187:drug effects; D014162:Transfection; D016896:Treatment Outcome; D016159:Tumor Suppressor Protein p53 / Q000235:genetics / Q000378:metabolism
chemical_list: D000970:Antineoplastic Agents; C000595707:BCL2 protein, human; C068651:E6 protein, Human papillomavirus type 16; C534424:MIRN184 microRNA, human; D035683:MicroRNAs; D009856:Oncogene Proteins, Viral; D019253:Proto-Oncogene Proteins c-bcl-2; D012097:Repressor Proteins; C495901:TP53 protein, human; D016159:Tumor Suppressor Protein p53; D002945:Cisplatin
keywords: HPV; cisplatin resistance; miR-184