Abstract:

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-delta CT 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.

Key words: microRNA;Melanoma;Cell transfection;Inhibitor