miR-21对视网膜母细胞瘤细胞增殖的影响及作用机制

目的探讨MicroRNA-21(miR-21)对视网膜母细胞瘤(RB)细胞增殖的影响及作用机制。方法采用Real-time PCR技术检测miR-21在正常视网膜组织和确诊RB组织中的表达情况;然后在转染的基础上运用MTT检查RB细胞存活率、流式细胞仪检测细胞凋亡率。Western blot法检测与细胞凋亡相关蛋白PDCD4、Bax、Bcl-2的表达。结果与正常视网膜组织miR-21表达(0.703±0.071)相比,RB组织miR-21为高表达(2.214±0.162),差异有统计学意义(P<0.01)。在Weri-Rb-1细胞中,与NC组(2.245±0.213)相比,miR-21抑制剂转染后明显降低了miR-21的表达水平,miR-21 inhibitor组为0.683±0.075,差异有统计学意义(P<0.01)。两组细胞转染后24 h、48 h、72 h、96 h,MTT测定法检测细胞活力结果显示:两组24 h的A值比较,差异无统计学意义(P>0.05),miR-21 inhibitor组在48 h、72 h、 96 h的A值均低于NC组,差异均有统计学意义...

Effects of MiR-21 on the proliferation of retinoblastoma and its mechanism

Objective　To investigate the effect of MicroRNA-21 (miRNA-21) on retinoblastoma (RB) cell proliferation and its possible mechanisms. Methods　Expression of miR-21 in RB tissue and human normal tissue was measured Real-time PCR. RB cells were transfected with miR-21 control or miR-21 inhibitor via LipofectaminTM 2000. Cell viability was analyzed by MTT assay. Flow cytometry with Annexin V-FITC/PI reagent was used to detect cell apoptosis. The protein levels of Bax, Bcl-2and PDCD4 were examined by Western blot. Results　miR-21 was overexpressed in RB tissues (2.214±0.162) when compared with normal retinal tissues (0.703±0.071) with significant difference (P<0.01). When compared with normal control (NC) group (2.245±0.213), in Weri-Rb-1 cells, miR-21 inhibitor transfection suppressed the expression of miR-21 in miR-21 inhibitor group (0.683±0.073) (P<0.01). In addition, 24 hours, 48 hours, 72 hours, 96 hours after transfection of the two groups of cells, the results of the viability of the cells via MTT assay showed that there was no statistically significant difference in the A value between the two groups at 24 hours (P>0.05), A values of miR-21 inhibitor group at 48 h, 72 h, 96 h were lower than those of the NC group, and the differences are statistically significant (all P<0. 01). The results of flow cytometry showed that the percentage of apoptotic cells in the NC group was (3.045 ± 0.301)% and (4.832 ± 0.493)%, and (2.593 ± 0.257)% and (40.167 ± 4.014)% in the miR-21 inhibitor group. The apoptosis rate of the Weir-Rb-1 cells in the miR-21 inhibitor group was significantly higher than that in the miR-21 NC group (P<0.01). The Western blot results showed that the expression of PDCD4 in the NC group (0.192 ± 0.045) was significantly reduced compared to the miR-21 inhibitor group (0.683 ± 0.091), and the expression level of the Bax protein in the NC group was 0.143 ± 0.036, which was significantly reduced compared to the miR-21 inhibitor group (1.192±0.054), and the difference was also statistically significant (P<0.01). The expression of Bcl-2 protein in the NC group (0.864±0.038) was significantly enhanced when compared with the miR-21 inhibitor group (0.257 ± 0.026), and the difference was statistically significant (P<0.05). Conclusion　miR-21 promotes carcinogenesis in the development and progression of RB. miR-21 inhibitor can inhibit the proliferation of Weri-RB-1 cells and increase the apoptosis of Weri-RB-1 cells by decreasing miR-21 expression. This process is related to apoptosis-related proteins such as PDCD4, Bax, and Bcl-2.