miRNA-21在人黑素瘤细胞系A375和M14中的表达及功能初探

目的 探讨miRNA-21在人黑素瘤细胞系A375、M14中的表达及对其细胞活性的影响。 方法 采用荧光定量PCR法，以U6基因为内参，分别检测A375、M14细胞中miRNA-21的相对含量。利用LipofectamineTM2000脂质体将三种浓度的miRNA-21抑制剂分别转染这两种细胞系，用CCK-8检测转染前后实验组、对照组的细胞活性。用SPSS13.0统计软件分析细胞活性的变化情况。结果 荧光定量PCR法检测提示，miRNA-21在A375细胞系中的表达（2－ΔCT值为1.2928 ± 0.1509）明显高于M14细胞系（2－ΔCT值为0.1894 ± 0.1803）。miRNA-21抑制剂浓度为90 nmol/L时，A375、M14细胞活性受到极显著抑制，细胞活性（R值）分别为0.7362 ± 0.1662、0.7295 ± 0.1478；当浓度为180 nmol/L、270 nmol/L时，A375细胞活性显著下降，R值分别为0.7248 ± 0.3204、0.6767 ± 0.2998，而M14细胞活性无显著变化。结论 miRNA-21在A375、M14两种人黑素瘤细胞系中均有不同程度的表达。miRNA-21在A375、M14细胞系中可以促进细胞增殖，可能下调了某些肿瘤抑制因子而起到癌基因样作用。

A preliminary study on the expression and function of microRNA-21 in two human malignant melanoma cell lines,A375 and M14

Objective To investigate the expression of microRNA-21(miRNA-21)in two human malignant melanoma cell lines,A375 and M14,and its effect on the viability of these cells.Methods The expression of human miRNA-21 was assessed by quantitative fluorescent PCR in A375 and M14 cells.Then,three concentrations(90,180,270 nmol/L)of miRNA-21 inhibitor and were transfected both cells and a negative control were transfected a mixture of LipofectamineTM 2000 reagent,respectively.After another 3-day culture,the proliferation of cells was detected by cell counting kit-8,and R value was calculated to denote the relative activity of cells.Statistical analysis was carried out by SPSS13.0.Results The expression of miRNA-21 was higher on A375 cells than that on M14 cells with the average value of 2-deltaCT being 1.2928±0.1509 vs 0.1894±0.1803.With miRNA-21 inhibitor at the concentration of 90,180,270 nmol/L,the activity of A375 cells was significantly lowered in comparison with that in the control group,with the R value being 0.7362±0.1662.0.7248±0.3204 and 0.6767±0.2998 respectively(all P＜0.01).However,in the case of M14 cells,cell activity was only suppressed by miRNA-21 inhibitor at 90 nmol/L with the R value being 0.7295±0.1478.and no significant inhibition was observed with the inhibitor at 180 or 270 nmol/L (both P＞0.05).Conclusions miRNA-21 is expressed on human melanoma cell lines,A375 and M14,at different levels,with a promoting effect on the proliferation of both cells.Moreover,miRNA-21 may act as an oncogene-like gene via down-regulating the expression of some tumor-inhibiting factors.