miR-206抑制 SDF-1/CXCR4信号活化诱导的乳腺癌细胞迁移和增殖

目的：研究 miR-206在乳腺癌细胞中的作用及其机制。方法 MDA-MB-231细胞分别转染miRNA-NC和 miR-206 mimic 后，荧光显微镜观察转染效率。同时，细胞添加不同剂量（20 ng·mL -1和40 ng·mL -1）基质细胞衍生因子1（SDF-1）处理，利用 Transwell 法检测细胞迁移，噻唑蓝（MTT）法检测细胞增殖，qRT-PCR 法检测细胞中 CXC 趋化因子受体4（ CXCR4）mRNA 表达水平，Western blot 检测细胞中CXCR4蛋白表达水平。结果 miRNA-NC 组和 miR-206 mimic 组细胞转染效率分别为（83.4±6.3）％和（87.6±8.3）％。与对照组比较，SDF-1显著促进细胞迁移和增殖（P ﹤0.05）。miR-206 mimic 转染明显抑制细胞迁移和增殖（ P ﹤0.05）。SDF-1处理促进细胞中 CXCR4 mRNA 和蛋白的表达水平（ P ﹤0.05）。miR-206 mimic 转染则抑制 CXCR4蛋白表达水平（P ﹤0.05），但不影响 CXCR4 mRNA 表达（P ﹥0.05）。结论 miR-206通过抑制 CXCR4表达拮抗 SDF-1诱导乳腺癌细胞迁移和增殖作用。

MiR-206 Suppresses Breast Cancer Cell Migration and Proliferation Induced by SDF-1/CXCR4 Signaling

Objective To explore the role of miR-206 in the breast cancer cells as well as its mechanism. Meth-ods Following the transfection of miRNA-NC and miR-206 mimic into MDA-MB-231 cells,the transfection effi-ciency was observed with a fluorescent microscope. Meanwhile,these cells were conditioned with different doses(20 ng·mL - 1 and 40 ng·mL - 1 )of stromal-derived factor-1(SDF-1). Cell migration was evaluated by Transwell as-say. Cell proliferation was determined by MTT assay. The mRNA expression of CXC chemokine receptor 4(CXCR4) was analyzed by qRT-PCR method. Protein expression of CXCR4 was analyzed by Western blot. Results The trans-fection efficiency of the miRNA-NC group and the miR-206 mimic group was(83. 4 ± 6. 3)% and(87. 6 ± 8. 3)% . Compared with the control group,SDF-1 significantly promoted cancer cells migration and proliferation(P ﹤0. 05). Transfection of miR-206 mimic markedly inhibited cancer cells migration and proliferation(P ﹤ 0. 05). SDF-1 conditioning enhanced the mRNA and protein expression of CXCR4 in cancer cells(P ﹤ 0. 05). Transfection of miR-206 mimic constrained CXCR4 protein expression(P ﹤ 0. 05),but did not influence its mRNA expression(P ﹥0. 05). Conclusion miR-206 counteracted the role of SDF-1 in inducing breast cancer cell migration and prolifera-tion through regression of CXCR4 expression.