miR-21在非小细胞肺癌组织细胞中的表达变化及其在细胞增殖、凋亡中的作用

Expression of miR-21 in non-small-cell lung cancer and its role in cell proliferation and apoptosis

目的 观察microRNA-21(miR-21)在非小细胞肺癌(NSCLC)组织和细胞中的表达变化,并通过抑制miR-21表达分析其在NSCLC细胞增殖、凋亡中的作用。方法 收集56例NSCLC患者手术切除癌组织及癌旁组织标本,培养人NSCLC细胞A549、人正常肺上皮细胞BEAS-2B,采用荧光定量PCR法检测组织和细胞中的miR-21。将A549细胞分为3组,抑制组、无义组分别用Lipofectamine^TM 2000转染miR-21的反义序列(miR-21 inhibitors)、无义序列(miR-21-NC),对照组不转染。转染后24h,采用MTT法测算细胞增殖率,采用流式细胞仪测算细胞凋亡率。结果 miR-21在NSCLC组织中表达高于癌旁组织(P<0.05),在A549细胞表达高于BEAS-2B细胞(P<0.05)。不同性别、年龄、病理类型及分化程度NSCLC组织中miR-21表达差异均无统计学意义(P均﹥0.05),TNMⅢ~Ⅳ期、有淋巴结转移的NSCLC组织中miR-21表达高于TNMⅠ~Ⅱ期、无淋巴结转移者(P均<0.05)。与无义组和对照组比较,抑制组细胞增殖率降低、细胞凋亡率升高(P均<0.05),无义组和对照组间细胞增殖率、细胞凋亡率差异无统计学意义(P均﹥0.05)。结论 miR-21在NSCLC组织和细胞中高表达,在NSCLC的发展中具有重要作用;降低miR-21表达可抑制肺癌细胞增殖、促进细胞凋亡,miR-21可作为NSCLC治疗的新靶点。

Objective To observe the expression of microRNA-21 (miR-21) in non-small-cell lung cancer (NSCLC) tissues and cells, and to analyze its role in the proliferation and apoptosis of NSCLC cells by inhibiting its expression. Methods The cancer tissue and adjacent tissue specimens from 56 patients with NSCLC were collected. Human NSCLC cell line A549 and human normal pulmonary epithelial cells BEAS-2B were cultured. The miR-21 in the tissues and cells was detected by fluorescence quantitative PCR. A549 cells were divided into three groups: inhibition group, nonsense group, and control group. Lipofectamine^TM 2000 was used to transfect the antisense sequence (miR-21 inhibitors) and the nonsense sequence (miR-21-NC) of miR-21 into the cells of the inhibition group and nonsense group, respectively, while cells in the control group were not transfected. At 24 h after transfection, MTT was used to measure the cell proliferation rate, and flow cytometry was used to measure the cell apoptosis rate. Results The expression of miR-21 in the NSCLC tissues was higher than that in the adjacent tissues ( P <0.05), and that in the A549 cells was higher than that in the BEAS-2B cells ( P <0.05). There was no significant difference in the expression of miR-21 in NSCLC tissues between patients with different gender, age, pathological type and differentiation degree ( P >0.05). The expression of miR-21 in tissues of TNM stage Ⅲ-Ⅳ with lymph node metastasis was higher than that of TNM stage Ⅰ-Ⅱ without lymph node metastasis ( P <0.05). Compared with the nonsense group and control group, the cell proliferation rate in the inhibition group decreased and the apoptosis rate increased (all P <0.05). No significant differences were found in cell proliferation rate and apoptosis rate between the nonsense group and control group (both P >0.05). Conclusion The miR-21 is highly expressed in NSCLC tissues and cells, and plays an important role in the development of NSCLC;reducing the miR-21 expression can inhibit the proliferation of lung cancer cells and promote apoptosis, and miR-21 can be a new target for the treatment of NSCLC.