[摘 要] 目的：探讨膀胱癌细胞中细胞色素c氧化酶亚基7A2（COX7A2）基因的表达，及其与顺铂联用对膀胱癌J82细胞增 殖、凋亡及线粒体功能影响。方法：采用生物信息学方法分析COX7A2在膀胱癌患者中的表达，并在J82细胞中进行验证。功能 实验分为对照组（仅转染阴性对照siNC）、siRNA组（仅转染COX7A2的siRNA）、对照组 + 顺铂组（先转染阴性对照后用顺铂处 理）和siRNA + 顺铂组（先敲低COX7A2后用顺铂处理）。CCK-8、Transwell迁移能力测试和克隆增殖实验检测对照组和siRNA 组中J82细胞的增殖、迁移能力。采用相应试剂盒检测各组细胞的ATP水平、活性氧（ROS）水平及线粒体膜电位(ΔΨm)，以评估 线粒体功能。流式细胞术检测各组细胞凋亡，以反映细胞的线粒体状态与对顺铂治疗的响应性关系。进一步通过癌症治疗响应 基因标识数据库（CTR-DB），分析COX7A2与接受顺铂联合治疗的膀胱癌患者预后的关系。结果：生物信息学分析与生存曲线 显示，COX7A2在膀胱癌患者中高表达并且与患者预后不良有关联。COX7A2在J82细胞中呈高表达（P < 0.05）。在未经顺铂处 理时，与对照组相比，siRNA组J82细胞增殖、迁移和克隆形成能力均显著下降（均P < 0.001），而线粒体的ATP表达减少（P < 0.01）、 ROS表达量增多（P < 0.000 1）、MMP发生去极化（P < 0.000 1），凋亡水平增加（P < 0.05）；顺铂处理后，与对照组 + 顺铂相比，siRNA + 顺铂组ATP表达减少（P < 0.01）、ROS表达量增多（P < 0.000 1）、MMP发生去极化（P < 0.000 1），线粒体功能受损，凋亡水平增加 （P < 0.001）。CTR-DB数据库生信分析显示，5例接受顺铂 + 多柔比星 + 甲氨蝶呤 + 长春碱联合治疗的膀胱癌患者中，有应答者比 无应答者COX7A2中位RNA表达量低（中位表达量：4 501 vs 5 009），12例铂类药物联合治疗的膀胱癌患者中有应答者比无应答 者COX7A2中位RNA表达量低（中位表达量：2 947 vs 3 035），由于样本量有限，虽观察到趋势但无统计学意义。结论：敲低 COX7A2可通过损伤线粒体功能，抑制膀胱癌细胞增殖与迁移，并可能由此增强细胞对顺铂诱导凋亡的敏感性。

[Abstract] Objective: To investigate cytochrome c oxidase subunit 7A2, mitochondrial (COX7A2) expression in bladder cancer cells, and the effects of its combination with cisplatin on the proliferation, apoptosis, and mitochondrial function of bladder cancer J82 cells. Methods: Bioinformatics analysis was used to assess COX7A2 expression in bladder cancer patients, with validation in the J82 cell. Functional experiments included four groups: the Control group (siNC transfection only), the siRNA group (COX7A2 siRNA transfection only), the Control + Cisplatin group (siNC transfection followed by cisplatin), and the siRNA + Cisplatin group (COX7A2 knockdown followed by cisplatin). CCK-8, Transwell migration assay, and colony formation assay detected the proliferation and migration abilities in the Control and siRNA groups. The ATP level, the ROS level, and MMP of cells in each group were detected using corresponding kits to assess mitochondrial function. Flow cytometry detected cell apoptosis in each group to reveal the responsive relationship between mitochondrial status and cisplatin treatment. Furthermore, the Cancer Treatment Response gene signature Database (CTR-DB) was utilized to analyze the correlation between COX7A2 expression and the prognosis of bladder cancer patients receiving cisplatin-based combination therapy. Results: Bioinformatics analysis and survival curves showed that COX7A2 was highly expressed in bladder cancer patients and was associated with poor prognosis. COX7A2 was significantly overexpressed in J82 cells (P < 0.05). Without cisplatin treatment, compared with the Control group, the siRNA group exhibited significantly decreased abilities in the proliferation, migration, and colony formation of J82 cells (all P < 0.001). Mitochondrial ATP expression decreased (P < 0.01); ROS expression levels increased (P < 0.000 1); MMP depolarized (P < 0.000 1), and the apoptosis levels increased (P < 0.05). After cisplatin treatment, compared with the Control + Cisplatin group, the siRNA + Cisplatin group showed decreased ATP expression (P < 0.01), increased ROS expression levels (P < 0.000 1), MMP depolarization (P < 0.000 1), impaired mitochondrial function, and increased apoptosis levels (P < 0.001). Bioinformatic analysis of the CTR-DB dataset indicated that among five bladder cancer patients receiving combination therapy of cisplatin, doxorubicin, methotrexate, and vincristine, responders had lower median COX7A2 RNA expression than non-responders (median expression: 4 501 vs 5 009). Similarly, among 12 bladder cancer patients receiving platinum-based combination therapies, responders showed lower median COX7A2 RNA expression than non-responders (median expression: 2 947 vs 3 035). However, due to the limited sample size, although a trend was observed, it did not reach statistical significance. Conclusion: Knockdown of COX7A2 can inhibit the proliferation and migration of bladder cancer cells by impairing mitochondrial function, and may thereby enhance cellular sensitivity to cisplatin-induced apoptosis.

[基金项目] 国家自然科学基金（No. 82472358）；邯郸市科学技术研究与发展计划（No. 21422083072）