目的：探讨circFBXL5 通过靶向miR-515-5p 影响膀胱癌T24 细胞的增殖、迁移、侵袭及其分子机制。方法：收集 2020 年4 月至2020 年6 月间在苏州市中西医结合医院手术切除的41 例膀胱癌组织及其癌旁组织，采用qPCR 法检测circFBXL5、 miR-515-5p 的表达；双荧光素酶报告实验验证circFBXL5 与miR-515-5p 之间的靶向关系，体外培养人膀胱癌T24 细胞，实验分为 si-NC 组、si-circFBXL5 组、anti-miR-NC+si-circFBXL5 组和si-circFBXL5+anti-miR-515-5p 组；MTT 法、细胞克隆形成实验、FCM、 Transwell 实验和WB 法分别检测转染后T24 细胞的增殖、细胞克隆形成、迁移、侵袭和凋亡及BAX、Bcl-2 蛋白水平。结果：膀胱 癌组织中 circFBXL5 呈高表达，miR-515-5p 呈低表达（均 P<0.05）；circFBXL5 靶向且负向调控 miR-515-5p 的表达；敲减 circFBXL5 后T24 细胞的增殖抑制率、凋亡率和BAX 蛋白水平均显著增高（均P<0.05），细胞克隆形成数和迁移、侵袭细胞数均显 著减少（均P<0.05），Bcl-2 蛋白水平显著降低（P<0.05）；同时敲减circFBXL5 和miR-515-5p 可部分逆转敲减circFBXL5 对T24 细胞增殖的抑制作用。结论：circFBXL5 通过调控 miR-515-5p 表达影响膀胱癌 T24 细胞的增殖、迁移、侵袭，circFBXL5 和 miR-515-5p 可能膀胱癌治疗的潜在分子靶标。

Objective: To investigate the effects of circFBXL5 on the proliferation, migration, and invasion of bladder cancer T24 cells by targeting miR-515-5p and its possible molecular mechanisms. Methods: 41 bladder cancer tissues and their adjacent tissues were collected at Suzhou Hospital of Integrated Traditional Chinese and Western Medicine from April 2020 to June 2020. The expressions of circFBXL5 and miR-515-5p were detected by qPCR. Dual-luciferase reporter assay was used to verify the targeting relationship between circFBXL5 and miR-515-5p. Human bladder cancer cells T24 were cultured in vitro and divided into si-NC group, si-circFBXL5 group, anti-miR-NC+si-circFBXL5 group, and si-circFBXL5+anti-miR-515-5p group. MTT assay, plate colony formation assay, flow cytometry, Transwell assay and Western blotting were used to detect cell proliferation, clone formation, migration, invasion, apoptosis and BAX and Bcl-2 protein levels of T24 cells after transfection, respectively. Results: circFBXL5 was highly expressed and miR-515-5p was lowly expressed in bladder cancer tissues (all P<0.05). circFBXL5 could negatively regulate the expression of miR-515-5p. After the knockdown of circFBXL5, the cell proliferation inhibition rate, apoptosis rate, and protein level of BAX were significantly increased (all P<0.05); the number of cell clone formation, migration, and invasion cells were decreased (all P<0.05); the protein level of Bcl-2 was significantly decreased (P <0.05). Knockdown of circFBXL5 and miR-515-5p simultaneously could partially reverse the inhibiting effect of circFBXL5 knockdown on T24 cells. Conclusion: circFBXL5 promoted the proliferation, migration, and invasion of bladder cancer T24 cells by inhibiting miR-515-5p expression. circFBXL5 and miR-515-5p may serve as potential molecular targets for bladder cancer treatment.

苏州市2017 年度产业技术创新专项资助项目（No. SYSD2017050）