miR-203在结直肠癌中的表达及其功能分析

目的 探讨microRNA-203（miR 203）在结直肠癌中的表达情况及其临床意义，并在结直肠癌细胞中验证其功能。方法 采用实时荧光定量PCR（qRT-PCR）检测52例结直肠癌及对应癌旁组织中miR-203的水平，分析miR-203表达与临床病理参数及术前癌胚抗原的关系；检测miR 203在3种结直肠癌细胞株SW480、Lovo和HT 29及人正常结肠黏膜上皮细胞NCM460中的表达情况，选取miR-203水平最低的细胞分别转染miR-203模拟物（mimics）和miR-203 control，采用MTT法、流式细胞仪PI／Annexin V双染法和Transwell法检测转染miR 203对细胞增殖、凋亡和侵袭能力的影响。结果 结直肠癌组织中miR-203的相对表达量为0.372±0.019，低于癌旁组织的miR-203水平，且其表达与TNM分期、淋巴结转移、肿瘤大小及术前癌胚抗原水平均有关（P＜0.05）；与NCM460细胞相比（其miR-203表达水平设为1.00），结直肠癌细胞SW480、Lovo和HT-29的miR 203相对表达量依次为0.26±0.07、0.44±0.05和0.32±0.04，选取SW480细胞进行后续实验。MTT检测显示，转染miR-203 mimics 48、72和96 h的SW480细胞吸光值均低于转染miR-203 control组，差异均有统计学意义（P＜0.05）；且转染miR-203 mimics 48和96 h的SW480细胞凋亡率高于转染miR-203 control组，但穿膜细胞数低于转染miR-203 control组（P＜0.05）。结论 miR-203在结直肠癌组织和细胞中低表达，上调miR 203水平可抑制结直肠癌细胞的增殖、侵袭并诱导凋亡。

The expression and function of microRNA-203 in colorectal cancer

Objective To explore the expression and clinical significance of microRNA 203 （miR-203） in colorectal cancer， and to verify its function in colorectal carcinoma cells. Methods The real time quantitative PCR （qRT-PCR） was used to detect the levels of miR-203 in 52 cases of colorectal cancer and corresponding adjacent tissues. The relationship between the levels of miR 203 and clinical pathological parameters （gender， age， tumor size， tumor location， tumor differentiation， clinical stage and lymph node metastasis） and preoperative carcinoembryonic antigen was carried out. The levels of miR 203 in three common colorectal cancer cell lines （SW480， Lovo and HT-29） and human normal colonic mucosal epithelial cells NCM460 were also measured via qRT PCR. The cell with the lowest miR-203 level was chosen and then subjected to the transfection with miR-203 analogue （mimics） and miR-203 control, respectively. The influences of miR-203 mimics on the cell proliferation， invasion and apoptosis were evaluated by MTT method， flow cytometry with PI／Annexin V double staining and Transwell， respectively. Results The relative expression of miR-203 in colorectal cancer tissues was 0.372±0.019， lower than that in para carcinoma tissues. The levels of miR-203 were related with TNM staging， lymph node metastasis， tumor size and preoperative carcinoembryonic antigen levels. When the miR 203 level in NCM460 cell was taken as reference （1.00）， the relative expression of miR-203 in SW480， Lovo and HT-29 cells were 0.26±0.07， 0.44± 0.05 and 0.32±0.04， respectively. As shown in the MTT analysis， the absorption values of miR-203 mimics group were lower than the miR 203 control group at 48， 72 and 96 h （P＜0.05）. Moreover， there were higher apoptotic rates but lower transmembrane cell numbers in miR-203 mimics group versus miR 203 control group at 48 and 96 h. Conclusion There are low levels of miR-203 in both colorectal cancer tissues and cells. The elevation of miR-203 can inhibit the cell proliferation and invasion but induce the apoptosis in colorectal cancer.