microRNA-224在结肠癌细胞中的表达及意义

目的：探讨microRNA-224（miR-224）对结肠癌细胞中的表达及意义。方法：用real-time PCR检测4种结肠癌细胞株（Caco-2、HCT116、HT-29、LoVo）和正常结肠黏膜组织中miR-224的表达水平；将HCT116细胞分别转染miR-224模拟物和阴性对照组序列，以未处理的HCT116细胞作为空白对照，用real-time PCR法检测各组细胞miR-224的表达水平，用MTT法和平板克隆实验法检测各组细胞的增殖情况，用流式细胞仪检测各组细胞周期情况。结果：4种结肠癌细胞株miR-224的表达均明显高于正常结肠黏膜组织（均P<0.05）；与空白对照组HCT116细胞比较，miR-224模拟物转染组HCT116细胞miR-224的表达水平明显升高，增殖活力明显增强，细胞克隆数量明显增高（均P<0.05）；细胞周期G1到S期转换的趋势增强（P=0.074）；阴性对照组序列转染组HCT116细胞的各项指标差异均无统计学意义（均P>0.05）。结论：miR-224在结肠癌细胞中表达上调，miR-224可能通过促进细胞增殖与细胞周期的演进，而在结肠癌发生发展的过程中发挥促癌基因的作用。

MicroRNA-224 expression in colon cancer cells and its significance

Objective: To investigate the expression and significance of microRNA-224 (miR-224) in colon cancer cells.Methods: The miR-224 expression in four colon cancer cell lines (Caco-2, HCT116, HT-29 and LoVo) and normal colonic mucosal tissue were detected by real-time RT-PCR; HCT116 cells were transfected with miR-224 mimics or scrambled negative control sequence respectively, using the untreated HCT116 cells as blank control, and then the miR-224 expression was determined by real-time PCR, proliferation status was measured by MTT assay and plate colony formation assay, and cell cycle phase distribution was analyzed by flow cytometry in each group of cells.Results: The miR-224 expression in each of the four colon cancer cell lines was higher than that in normal colonic mucosal tissue (all P<0.05). Compared with the HCT116 cells in blank control group, the miR-224 expression was significantly increased, proliferative ability was significantly enhanced, the number of colonies was significantly augmented (all P<0.05), and G1 to S phase transition showed an accelerating trend as well (P=0.074) in those in miR-224 mimics tranfection group; the differences in all the observed indexes showed no statistical significance in those in negative control sequence transfection group (all P>0.05). Conclusion: The miR-224 expression is up-regulated in colon cancer cells, which may promote cell proliferation and cell cycle progression, and thereby play a cancer-promoting gene role in the pathogenesis of colon cancer.