miR-144对甲状腺乳头状癌细胞增殖及细胞周期的影响

The influence of miR-144 on cell proliferation and cell cycle of papillary thyroid carcinoma cells

目的:研究甲状腺乳头状癌(PTC)细胞株中miR-144的表达水平,探讨miR-144不同表达水平对甲状腺癌细胞增殖能力及细胞周期的影响。方法:通过qPCR检测人PTC细胞K1、TPC-1和人甲状腺细胞Nthy-ori 3-1中miR-144的表达水平。K1细胞分别转染miR-144 mimics、miR-144 inhibitor及阴性对照(NC)。应用MTT增殖实验、克隆形成实验和流式细胞术分别检测miR-144不同表达水平对K1细胞生物学功能的影响。Western blot检测细胞周期蛋白Cyclin D1的表达情况。结果:PTC细胞中miR-144相对表达量与正常甲状腺细胞相比显著降低(P<0.05),其中K1细胞中miR-144的表达量最低。在K1细胞株中过表达miR-144后,细胞的增殖能力、单克隆形成能力显著下降,并且Cyclin D1表达水平降低,细胞被阻滞在G0/G1期(P<0.05)。而miR-144表达下调则得到相反的结果。结论:miR-144在PTC细胞中低表达。通过抑制PTC细胞增殖、阻滞细胞周期,miR-144可能在PTC的发生发展中扮演抑癌基因的角色。

Objective:To evaluate the expression levels of miR-144 in papillary thyroid carcinoma(PTC)cell lines.To explore the influence of up-regulation/down-regulation of miR-144 on cell proliferation and cell cycle in PTC cells.Methods:The expression levels of miR-144 in PTC cells K1,TPC-1 and human thyroid cells Nthy-ori 3-1 were detected by qPCR.K1 cells were transiently transfected with miR-144 mimics,inhibitor,or the negative control(NC)by Lipo2000.After transfection,MTT assay,colony formation assay and flow cytometry were conducted to explore the impact of miR-144 on cell proliferation ability and cell cycle of K1 cells.Western blot was provided to detect the protein expression of Cyclin D1.Results:Compared with thyroid cells,the relative expression levels of miR-144 in PTC cells were significantly decreased(P<0.05).The expression of miR-144 in K1 cells was lowest.The overexpression of miR-144 suppressed K1 cell proliferation and colony formation,caused K1 cells arrested in G0/G1 phase,which relate to downregulation of Cyclin D1.Whereas,low expression of miR-144 promoted cell proliferation,colony formation and accelerate the process of cell cycle.Conclusion:miR-144 was down-regulated in PTC cells.miR-144 may act as a tumor suppressor in PTC by inhibiting cell proliferation and blocking cell cycle,suggesting its use as a potential therapeutic target.