目的探讨microRNA-34a(miR-34a)通过靶向抑制Notch-1基因表达对人膀胱癌J82细胞增殖和迁移的影响。方法查询基因组数据库,应用基因预测软件进行生物信息学分析,预测miR-34a可能靶向调控Notchl基因;实时定量逆转录聚合酶链反应和蛋白印迹法分别检测16例浸润性膀胱癌组织及质粒转染的膀胱癌J82细胞的miR-34a和Notchl表达情况;萤光素酶实验检测miR-34a与Notchl基因的结合位点;将miR-34a表达质粒转染J82细胞,新型四唑氮盐化合物比色法和迁移实验评估miR-34a对细胞增殖和迁移的影响。结果浸润性膀胱癌组织miR-34a的表达中位数为0.016,四分位数间距0.018;Notchl基因表达中位数为2.765,四分位数间距2.156;癌旁组织miR.34a表达中位数为0.042,四分位数间距0.059;Notchl基因表达中位数为2.312,四分位数间距1.365,组间差异均有统计学意义(P〈0.01);浸润性膀胱癌组织的Notchl蛋白表达量为0.857±0.197,癌旁组织为0.648±0.171,组间差异有统计学意义(P〈0.01)。质粒转染J82细胞,miR-34a表达质粒组miR-34a的表达量为(2.408±0.789)×10-4,对照质粒组为(0.153±0.029)×10-4(P=0.0026);miR-34a表达质粒组Notchl基因表达量为3.001±0.106,对照组为4.998±1.053(P=0.0308);miR-34a表达质粒组Notchl蛋白表达量为0.747±0.050,对照组为0.988±0.102(P=0.0215);miR-34a表达质粒组细胞萤光素酶活性为0.422±0.028,对照组为2.392±0.148(P〈0.0001),组间差异均有统计学意义;miR-34a表达质粒组细胞增殖受到抑制,细胞迁移数量为179.3±21.02,对照组为269.7±23.71,组间差异有统计学意义(P=0.0078)。结论miR-34a可与Notchl基因的3’非翻译区(3’UTR)结合靶向抑制Notchl基因表达,进而抑制了膀胱癌J82细胞的增殖和迁移。
assessed by transwell migration assay. Results The expression level of miR-34 in invasive TCCB tissues was lower than in adjacent bladder tissues (0.016(0.018) vs 0. 042 (0. 059), N = 16; P =0.0006). On the contrary, the average levels of Notchl mRNA and protein were higher in tumors than in adjacent bladder tissues (2.765(2.156) vs 2.312(1.365), N =16; P=0.0025 and 0.857 ±0.197 vs 0.648 ±0.171; P 〈 0. 0001 ). After the transfection of miR-34a, the expressive level of miR-34a in J82 was highly induced ((2.408±0.789) ×10-4 vs(0.153 -+0.029) ×10-4; p=0.0026). However, the expressive levels of Notchl mRNA and protein were obviously decreased (3. 001± 0. 106 vs 4. 998 ~ 1. 053 ; P = 0. 0308 and 0. 747± 0. 050 vs 0. 988± 0. 102; P = 0. 0215 ). The results of luciferase assay showed that firefly activity was highly dimished (0. 422 ± 0. 028 vs 2. 392±0. 148 ; P 〈 0. 0001 ). Cellular proliferation was inhibited after the transfection of miR-34a in J82 (P 〈 0. 0001 ). Moreover, number of migration cells of J82 was significantly reduced after the ectopic expression of miR-34a ( 179.3 ± 21.02 vs 269.7 ± 23.71 ; P = 0. 0078 ). Conclusions miR-34a inhibits the cellular proliferation and migration of bladder cancer cell line J82 via binding to the 3'TR of Notchl mRNA.