上调miR-449a表达对肝癌细胞生长和侵袭能力的影响

目的:探讨miR-449a在肝癌(HCC)细胞中的表达及其对HCC细胞生物学行为的影响。方法:用qRT-PCR检测miR-449a在正常肝细胞L02和4种HCC细胞株(HepG2、Hep3B、SMMC-7721和Bel-7402)的表达。用脂质体法将miR-449a模拟物或阴性对照序列转染HCC细胞后,分别用CCK-8法、流式细胞术、Transwell小室实验检测细胞增殖、细胞周期、侵袭能力的变化,并观察以上两种不同转染的HCC细胞在裸鼠体内的成瘤情况。结果:miR-449a在4种HCC细胞株的表达水平均明显低于L02细胞(均P0.05),其中在Bel-7402细胞表达的水平最低。与转染阴性对照序列的Bel-7402细胞比较,转染miR-449a模拟物的Bel-7402细胞增殖活性明显降低、G_1/S期阻滞明显增加、穿室细胞数明显减少(均P0.05);与转染阴性对照序列的Bel-7402细胞比较,转染miR-449a模拟物的Bel-7402细胞在裸鼠体内成瘤后的移植瘤质量与体积均明显减小(0.748 g vs.1.234 g;33.667 mm~3 vs.1 400.500 mm~3,均P0.05)。结论:HCC细胞中miR-449a表达降低,上调miR-449a表达可以抑制HCC细胞在体内外的生长。

Expression and action of miR-449a in hepatocellular carcinoma cells

Objective: To investigate the miR-449a expression in hepatocellular carcinoma (HCC) cells and its effect on biological behaviors of HCC cells. Methods: The miR-449a expressions in normal hepatic L02 cells and 4 types of HCC lines (HepG2, Hep3B, SMMC-7721 and Bel-7402) were determined by qRT-PCR method. HCC cells were transfected with miR-449a mimics or scrambled sequences via lipofection, and then, the changes in cell proliferation, cell cycle and invasion ability were detected by CCK-8 assay, flow cytometry and Transwell assay respectively; moreover, the tumor formations of the HCC cells with above transfections in nude mice were observed. Results: The miR-449a expression levels in the 4 HCC cells were all significantly lower than those in L02 cells (all P<0.05), and showed the lowest level in Bel-7402 cells. Compared with Bel-7402 cells transfected with scrambled sequences, the proliferative activity was significantly inhibited, G1/S phase arrest was significantly increased, and the number of migrating cells was significantly decreased in Bel-7402 cells transfected with miR-449a mimics (all P<0.05). The weight and volume of xenografts derived from Bel-7402 cells transfected with miR-449a mimics in nude mice were all decreased compared with those derived from Bel-7402 cells transfected with scrambled sequences (0.748 g vs. 1.234 g; 33.667 mm3vs. 1 400.500 mm3, both P<0.05). Conclusion: The miR-449a expression is decreased in HCC cells, and up-regulating miR-449a expression can suppress the growth of HCC cells in vivo and in vitro.