目的:检测膀胱尿路上皮癌中微小RNA-15b-5p(miR-15b-5p)的表达，探讨其靶向犰狳重复X连锁蛋白2(ARMCX2)对细胞增殖的调控作用。方法:选择69例2014年6月至2015年5月在海南医学院第二附属医院确诊并行手术治疗膀胱尿路上皮癌的患者，留取肿瘤组织。实时荧光定量PCR(qPCR)检测miR-15b-5p、免疫组织化学法检测ARMCX2和细胞核增殖抗原(Ki-67)的表达。选择尿路上皮癌T24细胞系，应用双荧光素酶报告基因实验验证miR-15b-5p和ARMCX2的靶向关系。建立无关序列组(NC组)、miR-15b-5p mimic组、miR-15b-5p inhibitor组、miR-15b-5p inhibitor和小干扰RNA(siRNA)-ARMCX2共转染组，应用蛋白质印迹法(Western blot)检测ARMCX2和Ki-67的表达，应用细胞计数试剂盒(CCK-8)检测细胞活性。两组间比较行独立样本的n t检验，多组间比较行方差分析(SNK法行两两比较)。n 结果:膀胱尿路上皮癌中miR-15b-5p的表达量范围为1.2～4.5，miR-15b-5p的表达量和ARMCX2的阳性率在不同病变级别(1.51±0.26比2.04±0.43，n t＝4.560，n P0.05)的表达差异无统计学意义。n 结论:MiR-15b-5p在膀胱尿路上皮癌中低表达，与肿瘤细胞的增殖及生长相关。MiR-15b-5p靶向ARMCX2抑制尿路上皮癌细胞的增殖。“,”Objective:To detect the expression of microRNA (miRNA, miR)-15b-5p in urothelial carcinoma of bladder and analyze the regulatory effect of miR-15b-5p armadillo repeat-containing X-linked protein 2 (ARMCX2) on cell proliferation.Methods:A total of 69 cases of urothelial carcinoma of bladder were selected. The expression of miR-15b-5p was detected by quantitative polymerase chain reaction (qPCR), andARMCX2and Ki-67 were detected by immunohistochemistry (IHC) mehtod. T24 cell line of urothelial carcinoma was selected. The targeting relationship between miR-15b-5p and ARMCX2 was verified by double luciferase reporter gene assay. Unrelated sequence group (NC group), miR-15b-5p mimic group, miR-15b-5p inhibitor group, miR-15b-5pinhibitor and small interfering RNA (siRNA)-ARMCX2 co-transfection group were established. The expression of ARMCX2 and proliferation cell nuclear antigen (Ki-67) was detected by Western blotting. Cell activity was detected by cell counting kit-8 (CCK-8) assay.Results:Expression range of miR-15b-5p was 1.2-4.5 in urothelial carcinoma. The expressions of miR-15b-5p and ARMCX2 were statistically significant in pathological grades (1.51±0.26 vs. 2.04±0.43, n t=4.560, n P0.05) were not significantly changed in miR-15b-5p inhibitor and siRNA-ARMCX2 co transfected group.n Conclusion:MiR-15b-5p is lower expression in urothelial carcinoma, which is related to the proliferation and growth of tumor cells.MiR-15b-5p negatively regulates ARMCX2 to proliferation on urothelial carcinoma cells. MiR-15b-5p and ARMCX2 may be independent prognostic factors of urothelial carcinoma.