title: MicroRNA-3646 Contributes to Docetaxel Resistance in Human Breast Cancer Cells by GSK-3β/β-Catenin Signaling Pathway.
abstract: Acquisition of resistance to docetaxel (Doc) is one of the most important problems in treatment of breast cancer patients, but the underlying mechanisms are still not fully understood. In present study, Doc-resistant MDA-MB-231 and MCF-7 breast cancer cell lines (MDA-MB-231/Doc and MCF-7/Doc) were successfully established in vitro by gradually increasing Doc concentration on the basis of parental MDA-MB-231 and MCF-7 cell lines (MDA-MB-231/S and MCF-7/S). The potential miRNAs relevant to the Doc resistance were screened by miRNA microarray. We selected 5 upregulated miRNAs (has-miR-3646, has-miR-3658, has-miR-4438, has-miR-1246, and has-miR-574-3p) from the results of microarray for RT-qPCR validation. The results showed that expression level of miR-3646 in MDA-MB-231/Doc cells was significantly higher than in MDA-MB-231/S cells. Compared to MCF-7/S cells, miR-3646 expression was up-regulated in MCF-7/Doc cells. Further studies revealed that transfection of miR-3646 mimics into MDA-MB-231/S or MCF-7/S cells remarkably increased their drug resistance, in contrast, transfection of miR-3646 inhibitors into MDA-MB-231/Doc or MCF-7/Doc cells resulted in significant reduction of the drug resistance. By the pathway enrichment analyses for miR-3646, we found that GSK-3β/β-catenin signaling pathway was a significant pathway, in which GSK-3β was an essential member. RT-qPCR and Western blot results demonstrated that miR-3646 could regulate GSK-3β mRNA and protein expressions. Furthermore, a marked increase of both nuclear and cytoplasmic β-catenin expressions (with phosphorylated-β-catenin decrease) was observed in MDA-MB-231/Doc cells compared with MDA-MB-231/S cells, and their expression were positively related to miR-3646 and negatively correlated with GSK-3β. Taken together, our results suggest that miR-3646-mediated Doc resistance of breast cancer cells maybe, at least in part, through suppressing expression of GSK-3β and resultantly activating GSK-3β/β-catenin signaling pathway.
authors.affiliation: Center of Clinical Laboratory Science, Jiangsu Cancer Hospital Affiliated to Nanjing Medical University, Nanjing 210009, China.
authors.forename: Xiaohui
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Center of Clinical Laboratory Science, Jiangsu Cancer Hospital Affiliated to Nanjing Medical University, Nanjing 210009, China.
authors.forename: Shanliang
authors.initials: S
authors.lastname: Zhong
authors.affiliation: Department of Oncology, Nanjing First Hospital, Nanjing 210006, China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Xu
authors.affiliation: Department of General Surgery, Jiangsu Cancer Hospital, Nanjing 210009, China.
authors.forename: Dandan
authors.initials: D
authors.lastname: Yu
authors.affiliation: Department of Clinical Laboratory, Wuxi Second Hospital, Wuxi 214002, China.
authors.forename: Tengfei
authors.initials: T
authors.lastname: Ma
authors.affiliation: Department of General Surgery, Jiangsu Cancer Hospital, Nanjing 210009, China.
authors.forename: Lin
authors.initials: L
authors.lastname: Chen
authors.affiliation: Center of Clinical Laboratory Science, Jiangsu Cancer Hospital Affiliated to Nanjing Medical University, Nanjing 210009, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: Department of General Surgery, Jiangsu Cancer Hospital, Nanjing 210009, China.
authors.forename: Xiu
authors.initials: X
authors.lastname: Chen
authors.affiliation: Department of General Surgery, Jiangsu Cancer Hospital, Nanjing 210009, China.
authors.forename: Sujin
authors.initials: S
authors.lastname: Yang
authors.affiliation: Center of Clinical Laboratory Science, Jiangsu Cancer Hospital Affiliated to Nanjing Medical University, Nanjing 210009, China.
authors.forename: Yueqin
authors.initials: Y
authors.lastname: Wu
authors.affiliation: Department of General Surgery, Jiangsu Cancer Hospital, Nanjing 210009, China.
authors.forename: Jinhai
authors.initials: J
authors.lastname: Tang
authors.affiliation: Center of Clinical Laboratory Science, Jiangsu Cancer Hospital Affiliated to Nanjing Medical University, Nanjing 210009, China.
authors.forename: Jianhua
authors.initials: J
authors.lastname: Zhao
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects / Q000235:genetics; D001943:Breast Neoplasms / Q000473:pathology*; D045744:Cell Line, Tumor; D000077143:Docetaxel; D019008:Drug Resistance, Neoplasm / Q000235:genetics*; D005260:Female; D038362:Glycogen Synthase Kinase 3 / Q000378:metabolism*; D000071679:Glycogen Synthase Kinase 3 beta; D006801:Humans; D035683:MicroRNAs / Q000502:physiology*; D015398:Signal Transduction / Q000235:genetics*; D043823:Taxoids / Q000494:pharmacology*; D051176:beta Catenin / Q000378:metabolism*
chemical_list: D000970:Antineoplastic Agents; C000610116:MIRN3646 microRNA, human; D035683:MicroRNAs; D043823:Taxoids; D051176:beta Catenin; D000077143:Docetaxel; C000605506:GSK3B protein, human; D000071679:Glycogen Synthase Kinase 3 beta; D038362:Glycogen Synthase Kinase 3