特异性miR-221抑制剂对结直肠癌细胞增殖及凋亡的影响

Effect of miR-221-specific inhibitor on the proliferation and apoptosis of human colorectal carcinoma cells

目的探讨miR-221在结直肠癌细胞中的表达状况及特异性miR-221抑制剂对癌细胞增殖和凋亡的影响。方法应用实时荧光定量PCR(real-time Q-PCR)检测四种人结肠癌细胞系HT-29、Lovo、SW-480、Caco2中miRNA-221表达状况,并以人脐静脉内皮细胞HUVEC作为正常对照;设计并合成miR-221、anti-miR-221(微小RNA抑制剂)寡核苷酸,以脂质体转染Caco2细胞系,以Real-time Q-PCR再次检测转染后细胞中miR-221表达状况,并通过噻唑蓝(MTT)比色法及流式细胞仪观察细胞的增殖和凋亡状态。结果与正常细胞相比,4种人结肠癌细胞系中miR-221表达均显著增高,差异具有统计学意义(P<0.01);癌细胞转染anti-miR-221后,G0/G1期细胞比例明显增加,而S期细胞比例显著下降,并可见细胞凋亡的发生(P<0.01)。结论 miR-221特异性抑制剂可通过抑制细胞增殖同时诱导凋亡而抑制结直肠癌细胞生长,提示miR-221作为结直肠癌生物治疗有效靶点有进一步研究价值。

Objective To investigate miRNA-221 expression in human colorectal carcinoma（CRC） cells and the effects of miR-221-specific inhibitor on the proliferation and apoptosis of CRC cells.Methods Four human CRC cell lines（HT-29,Lovo,SW-480,and CaCO2） were examined for miRNA-221 expression using real-time Q-PCR.The specific 2,-methoxy-modified RNA oligonucleotides of miR-221（anti-miR-221） were synthesized and transfected into Caco2 cells via liposome,and the changes in the expression of miR-221 in the cells were detected by real-time Q-PCR.The proliferation and apoptosis of the transfected CRC cells were detected using MTT assay and flow cytometry.Results The 4 human CRC cells showed significantly upregulated expression of miR-221 compare with HUVECs（P0.01）.The miR-221-specific inhibitor,anti-miR-221,significantly inhibited the expression of miR-221 in Caco2 cells and suppressed the cell proliferation,causing also obvious cell apoptosis（P0.01）.Conclusion The miR-221-specific inhibitor shows potent inhibitory effect on the growth of CRC cells,suggesting its value as a potential anti-tumor candidate for treatment of CRC.