Purpose. Cisplatin is one of the most effective drugs for treating ovarian carcinoma (OC), which is among the most lethal types of carcinoma. However, the chemoresistance to cisplatin that develops over time leads to a poor clinical outcome for many OC patients. Therefore, it is necessary to clearly understand the molecular mechanisms of chemoresistance. In this study, we examined how Hsa-miR-105-1 functions in cisplatin-resistant OC cells. Methods. The levels of Hsa-miR-105-1 expression in cisplatin-sensitive and resistant OC cell lines were detected by qRT-PCR. The target gene of Hsa-miR-105-1 was predicted by using the TargetScan and Starbase databases and verified by the double luciferase reporter gene assay. The target gene of Hsa-miR-105-1 was identified as ANXA9, and ANXA9 expression was evaluated by qRT-PCR, western blotting, and immunofluorescence. To validate the function of Hsa-miR-105-1 in OC cells, we silenced or overexpressed Hsa-miR-105-1 in cisplatin-sensitive or resistant OC cell lines, respectively. Furthermore, the expression levels of several apoptosis-related proteins, including P53, P21, E2F1, Bcl-2, Bax, and caspase-3, were examined by western blot analysis. Results. The levels of Hsa-miR-105-1 expression were abnormally downregulated in cisplatin-resistant OC cells, while ANXA9 expression was significantly upregulated in those cells. Treatment with an Hsa-miR-105-1 inhibitor promoted the expression of ANXA9 mRNA and protein, enhanced the resistance to cisplatin, and attenuated the cell apoptosis induced by cisplatin in cisplatin-sensitive OC cells. Moreover, treatment with Hsa-miR-105-1 mimics inhibited ANXA9 expression, which further increased the levels of P53, P21, and Bax expression and decreased the levels of E2F1 and Bcl-2 expression, finally resulting in an increased sensitivity to cisplatin in cisplatin-resistant OC cells. Conclusion. We found that a downregulation of Hsa-miR-105-1 expression enhanced cisplatin-resistance, while an upregulation of Hsa-miR-105-1 restored the sensitivity of OC cells to cisplatin. The Hsa-miR-105-1/ANXA9 axis plays an important role in the cisplatin-resistance of OC cells.

中文翻译：

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Hsa-miR-105-1 通过靶向 ANXA9 调节卵巢癌细胞对顺铂的耐药性

目的。顺铂是治疗卵巢癌（OC）最有效的药物之一，卵巢癌是最致命的癌症之一。然而，随着时间的推移对顺铂产生的化学抗性导致许多 OC 患者的临床结果不佳。因此，有必要清楚地了解化学抗性的分子机制。在这项研究中，我们检查了 Hsa-miR-105-1 如何在顺铂耐药的 OC 细胞中发挥作用。方法。通过qRT-PCR检测顺铂敏感和耐药OC细胞系中Hsa-miR-105-1的表达水平。Hsa-miR-105-1的靶基因通过TargetScan和Starbase数据库进行预测，并通过双荧光素酶报告基因检测进行验证。Hsa-miR-105-1的靶基因被鉴定为ANXA9, 并通过 qRT-PCR、蛋白质印迹和免疫荧光评估ANXA9的表达。为了验证 Hsa-miR-105-1 在 OC 细胞中的功能，我们分别在顺铂敏感或耐药的 OC 细胞系中沉默或过表达 Hsa-miR-105-1。此外，通过蛋白质印迹分析检测了几种凋亡相关蛋白的表达水平，包括 P53、P21、E2F1、Bcl-2、Bax 和 caspase-3。结果。Hsa-miR-105-1 表达水平在顺铂耐药 OC 细胞中异常下调，而ANXA9在这些细胞中表达显着上调。用 Hsa-miR-105-1 抑制剂处理促进了 ANXA9 mRNA 和蛋白的表达，增强了对顺铂的耐药性，并减弱了顺铂在顺铂敏感的 OC 细胞中诱导的细胞凋亡。此外，用 Hsa-miR-105-1 模拟物处理抑制ANXA9的表达，这进一步增加了 P53、P21 和 Bax 的表达水平并降低了 E2F1 和 Bcl-2 的表达水平，最终导致对顺铂的敏感性增加。顺铂耐药的 OC 细胞。结论。我们发现 Hsa-miR-105-1 表达的下调增强了顺铂耐药性，而 Hsa-miR-105-1 的上调恢复了 OC 细胞对顺铂的敏感性。Hsa-miR-105-1/ ANXA9轴在 OC 细胞的顺铂耐药中起重要作用。