Bao Jie, Xu Yun, Wang Qunying, Zhang Jinping, Li Zhenjie, Li Dongying, Li Jiansheng
Department of Gastroenterology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450000, China.
Department of Gastroenterology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450000, China.
Biomed Pharmacother. 2017 Aug;92:1030-1037. doi: 10.1016/j.biopha.2017.06.011. Epub 2017 Jun 10.
Chemoresistance remains a main clinical obstacle in the treatment of gastric cancer (GC). microRNAs have been revealed to participate in the regulation of drug resistance in a variety of cancers. However, little is known about the function and detailed molecular mechanism of miR-101 in GC chemoresistance.
The expressions of miR-101 and Annexin A2 (ANXA2) in GC tissues and cells were detected by qRT-PCR and western blot. The effects of miR-101 overexpression on P-glycoprotein (P-gp) at mRNA and protein levels, cell viability, and apoptosis in drug-resistant GC cells were examined by qRT-PCR, western blot, MTT and flow cytometry analysis, respectively. Luciferase reporter assay, RNA immunoprecipitation (RIP) and qRT-PCR were applied to confirm whether miR-101 could target ANXA2 and regulate its expression. Rescue experiment was performed to verify the mechanism by which miR-101 involved in chemoresistance.
miR-101 was downregulated in GC tissues and drug-resistant GC cells. A negative correlation between miR-101 and ANXA2 expression was observed in GC tissues. Forced expression of miR-101 significantly reduced P-gp expression at mRNA and protein levels in drug-resistant GC cells. Overexpression of miR-101 enhanced sensitivity to cisplatin (DDP) or vincristine (VCR) via viability inhibition and apoptosis promotion. ANXA2 was identified as a direct target of miR-101 and miR-101 negatively regulated ANXA2 expression. Moreover, ectopic expression of ANXA2 reversed the effect of miR-101 on P-gp expression, cell viability and apoptosis.
miR-101 alleviated chemoresistance of gastric cancer cells by targeting ANXA2. Therefore, targeting miR-101 may be a potential therapeutic approach for drug-resistant GC.
化疗耐药仍然是胃癌（GC）治疗中的主要临床障碍。微小RNA已被揭示参与多种癌症的耐药性调控。然而，关于miR-101在GC化疗耐药中的功能及详细分子机制知之甚少。
采用qRT-PCR和蛋白质免疫印迹法检测GC组织和细胞中miR-101和膜联蛋白A2（ANXA2）的表达。分别通过qRT-PCR、蛋白质免疫印迹法、MTT法和流式细胞术分析检测miR-101过表达对耐药GC细胞中P-糖蛋白（P-gp）mRNA和蛋白水平、细胞活力及凋亡的影响。采用荧光素酶报告基因检测、RNA免疫沉淀（RIP）和qRT-PCR来确认miR-101是否能靶向ANXA2并调节其表达。进行拯救实验以验证miR-101参与化疗耐药的机制。
miR-101在GC组织和耐药GC细胞中表达下调。在GC组织中观察到miR-101与ANXA2表达呈负相关。miR-101的强制表达显著降低了耐药GC细胞中P-gp在mRNA和蛋白水平的表达。miR-101的过表达通过抑制细胞活力和促进凋亡增强了对顺铂（DDP）或长春新碱（VCR）的敏感性。ANXA2被确定为miR-101的直接靶点，且miR-101负向调节ANXA2的表达。此外，ANXA2的异位表达逆转了miR-101对P-gp表达、细胞活力和凋亡的影响。
miR-101通过靶向ANXA2减轻胃癌细胞的化疗耐药性。因此，靶向miR-101可能是耐药GC的一种潜在治疗方法。
