目的：探讨环指蛋白8（RNF8）对子宫内膜癌（EC）细胞顺铂（CDDP）敏感性的影响及可能机制。方法：基于在线数据库分析RNF8在EC组织中的表达及拷贝数变异；采用慢病毒介导shRNA稳定敲低Ishikawa细胞中RNF8表达并进行CDDP处理，按sh-NC+溶剂对照、sh-RNF8+溶剂对照、sh-NC + CDDP、sh-RNF8 + CDDP分组处理，并设置sh-RNF8 + CDDP + KU60019抑制实验。采用CCK-8、克隆形成、Annexin V-FITC/PI流式细胞术、Hoechst 33258/PI染色、WB及γ-H2AX免疫荧光检测细胞活力、克隆形成、凋亡、DNA损伤累积及ATM/CHK2通路相关蛋白表达。结果：RNF8在EC组织和细胞中表达升高。RNF8敲低降低细胞存活率和IC50，抑制克隆形成，并进一步增强CDDP诱导的凋亡；同时BAX、Cleaved-Caspase-3和γ-H2AX表达升高，BCL-2、p-ATM、p-CHK2和RAD21表达降低。KU60019处理进一步促进DNA损伤累积和细胞凋亡，并降低细胞活力。结论：RNF8可能通过ATM/CHK2轴促进DNA损伤应答并降低EC细胞对CDDP的敏感性；敲低RNF8可增加DNA损伤累积并增强CDDP敏感性。

Objective: To investigate the role of RING finger protein 8 (RNF8) in cisplatin (CDDP) sensitivity in endometrial cancer (EC) and its possible mechanism. Methods: The expression level of RNF8 in endometrial cancer tissues and its copy number variation profile were analyzed using an online database. Lentivirus-mediated shRNA was used to stably knock down RNF8 expression in Ishikawa cells, followed by CDDP treatment. The cells were grouped: sh-NC + solvent control, sh-RNF8 + solvent control, sh-NC + CDDP, and sh-RNF8 + CDDP. An inhibition experiment was conducted using the sh-RNF8 + CDDP + KU60019 combination. CCK-8 assays, colony formation assays, Annexin V-FITC/PI flow cytometry, Hoechst 33258/PI staining, WB, and γ-H2AX immunofluorescence were used to assess cell viability, colony formation, apoptosis, DNA damage, and the expression of proteins related to the ATM/CHK2 pathway. Results: RNF8 was significantly overexpressed in endometrial cancer tissues and cells. RNF8 knockdown reduced cell viability and IC50, inhibited colony formation, and further enhanced CDDP-induced apoptosis. Meanwhile, the expression of BAX, Cleaved-Caspase-3, and γ-H2AX increased, while the expression of BCL-2, p-ATM, p-CHK2, and RAD21 decreased. Treatment with KU60019 further promoted DNA damage and apoptosis, and reduced cell viability. Conclusion: RNF8 may promote DNA damage response and reduce the sensitivity of endometrial cancer cells to CDDP via the ATM/CHK2 axis. Knocking down RNF8 increases DNA damage and enhances sensitivity to CDDP.

江苏省妇幼健康科研项目（F202167）