miR-31在结直肠癌患者血清中的表达及对结肠癌HCT116细胞增殖及凋亡的影响

Expression of serum miR-31 in colorectal cancer patients and its effect on cell proliferation and apoptosis

背景与目的:micro RNA与肿瘤关系密切,血清mi RNAs可以作为筛选和监测结直肠癌的有效指标。该研究旨在检测结直肠癌患者血清中mi R-31的表达水平,并分析mi R-31对结肠癌细胞增殖、凋亡及细胞周期的影响。方法:收集40例结直肠癌患者和35例健康人群作为对照,采用实时荧光定量聚合酶链反应(realtime fluorescent quantitative polymerase chain reaction,RTFQ-PCR),检测其血清mi R-31的表达水平,并分析结直肠癌患者血清mi R-31的表达水平与临床病理特征之间的关系。采用脂质体转染将mi R-31模拟物(mi R-31 mimics)和抑制剂(mi R-31 inhibitor)转染到HCT116细胞,采用CCK-8法检测细胞增殖,流式细胞术检测细胞凋亡及周期改变。结果:结直肠癌患者血清中mi R-31的表达显著高于健康对照组,mi R-31表达与结直肠癌分化程度有关。转染mi R-31mimics组HCT116细胞生长增快,而转染mi R-31抑制剂后细胞增殖能力明显降低(P<0.01);同时mi R-31mimics组细胞凋亡所占比例较mi R-31抑制剂组和阴性对照组(mi R-control,NC)明显减少,尤其是晚期凋亡细胞减少为著;转染mi R-31抑制剂组,G_1期细胞较mi R-31 mimics组和NC组明显增多。结论:mi R-31在结直肠癌患者血清中表达显著上调,mi R-31可能通过促进结肠癌细胞增殖、抑制细胞凋亡而参与了结直肠癌的发展进程,有望成为结直肠癌诊断的标志物。

Background and purpose： miRNA plays important roles in tumorigenesis. It has been reported that many kinds of serum miRNA serve as markers for tumor diagnosis and screening. This study aimed to detect the expression of serum miRNA-31 （miR-31） in coloreetal cancer patients and to explore the effect of miR-31 on cell proliferation, apoptosis and cell cycle distribution. Methods： The expressions of miR-31 in 40 cases of colorectal cancer serum and 35 cases of the healthy control were examined by real-time fluorescent quantitative polymerase chain reaction （RTFQ-PCR）. The correlation between miR-31 expression and clinicopathological features of colorectal cancer （including age, gender, depth of infiltration, lymph node metastasis, clinical stage） were further analyzed. The miR-31 mimics, inhibitor and miR-control （negative control） were transfected into HCT116 cells. The effect of miR-31 on cell proliferation was evaluated by CCK-8 method. Flow cytometry was used to examine the change of cell apoptosis and cell cycle. Results： Relative expression of serum miR-31 was significantly increased in cancer patients compared with healthy controls （P〈0.01）. Expression of serum miR-31 was higher in poorly differentiated carcinoma than that in well or moderately differentiated carcinoma （P〈0.05）. No correlation was found between serum miR-31 expression and other clinicopathological variables. CCK-8 assay showed that after transfection with miR-31 mimics, the cell proliferation was increased, compared with miR-31 inhibitor and negative control group. Meantime, the apoptotic cell number was significantly decreased, particularly in late apoptosis. The cell number of G1 stage was remarkably increased in miR-31 inhibitor group, compared with miR-31mimics and negative control group. Conclusion： The expression of serum miR- 31 is higher in colorectal cancer, miR-31 can promote cell proliferation and irthibit the apoptosis of HCT 116 cells. It might be a potential biomarker for colorectal cancer.