Yang Song, Wang Peng, Wang Songhua, Cong Aihua, Zhang Qi, Shen Wenhao, Li Xiangyi, Zhang Wei, Han Gaohua
Department of Oncology, Taizhou People's Hospital, Taizhou, Jiangsu 225300, People's Republic of China.
Department of Endocrinology, Taizhou People's Hospital, Taizhou, Jiangsu 225300, People's Republic of China.
Cancer Manag Res. 2020 Jun 25;12:4981-4990. doi: 10.2147/CMAR.S251264. eCollection 2020.
Cisplatin (CDDP) is extensively used for esophageal adenocarcinoma (EAC) chemotherapy, while cisplatin resistance is getting worse. microRNA-181a-5p (miR-181a-5p) has been reported to play an important role in various human cancers. However, the effect and underlying mechanism of miR-181a-5p in cisplatin resistance of EAC remain unclear.
Cisplatin-resistant EAC cells OE19/CDDP and parental sensitive OE19 cells were applied for experiments in vitro. The expressions of miR-181a-5p and CBLB were measured by quantitative real-time polymerase chain reaction (qRT-PCR) or Western blot. The cisplatin resistance of cells was expressed by cell viability, IC50 and apoptosis rate by using CCK-8 assay or flow cytometry. The interaction between miR-181a-5p and CBLB was evaluated by luciferase reporter assay and RIP assay. In vivo experiments were conducted via the murine xenograft model.
miR-181a-5p was highly expressed while CBLB was lowly expressed in OE19 cell lines compared with OE19/CDDP cells. In cisplatin-resistant OE19/CDDP cells, miR-181a-5p up-regulation or CBLB knockdown inhibited cell viability and inducted apoptosis. In cisplatin-sensitive OE19 cells, miR-181a-5p inhibition or CBLB overexpression promoted cell viability and suppressed apoptosis. CBLB was confirmed to be a target of miR-181a-5p, and rescue assay showed CBLB overexpression reversed the suppression of OE19/CDDP cell viability induced by miR-181a-5p up-regulation, and its down-regulation attenuated miR-181a-5p-inhibition-mediated enhancement of OE19 cell viability. In addition, miR-181a-5p up-regulation enhanced the cytotoxicity of cisplatin in EAC in vivo.
miR-181a-5p enhanced the sensitivity of cells to cisplatin in EAC by targeting CBLB, indicating a promising sensitizer of cisplatin therapy in clinical esophageal cancer.
顺铂（CDDP）广泛用于食管腺癌（EAC）化疗，而顺铂耐药性日益严重。据报道，微小RNA-181a-5p（miR-181a-5p）在多种人类癌症中发挥重要作用。然而，miR-181a-5p在EAC顺铂耐药中的作用及潜在机制仍不清楚。
将顺铂耐药的EAC细胞OE19/CDDP和亲本敏感的OE19细胞用于体外实验。通过定量实时聚合酶链反应（qRT-PCR）或蛋白质免疫印迹法检测miR-181a-5p和CBLB的表达。采用CCK-8法或流式细胞术通过细胞活力、半数抑制浓度（IC50）和凋亡率来表示细胞的顺铂耐药性。通过荧光素酶报告基因检测和RNA免疫沉淀（RIP）检测评估miR-181a-5p与CBLB之间的相互作用。通过小鼠异种移植模型进行体内实验。
与OE19/CDDP细胞相比OE19细胞系中miR-181a-5p高表达而CBLB低表达。在顺铂耐药的OE19/CDDP细胞中，miR-181a-5p上调或CBLB敲低抑制细胞活力并诱导凋亡。在顺铂敏感的OE19细胞中，miR-181a-5p抑制或CBLB过表达促进细胞活力并抑制凋亡。证实CBLB是miR-181a-5p的靶标，挽救实验表明CBLB过表达逆转了miR-181a-5p上调诱导的OE19/CDDP细胞活力抑制，其下调减弱了miR-181a-5p抑制介导的OE19细胞活力增强。此外，miR-181a-5p上调增强了顺铂在体内对EAC的细胞毒性。
miR-181a-5p通过靶向CBLB增强了EAC细胞对顺铂的敏感性，表明其在临床食管癌中是一种有前景的顺铂治疗增敏剂。
