Effect of microRNA-21 and microRNA-494 on cell cycle of and apoptosis in a human melanoma cell line A375 / 中华皮肤科杂志

ABSTRACT

Objective To optimize the concentration of a microRNA-21 (miR-21) inhibitor and a miR-494 mimic for the transfection of A375 human melanoma cells,and to estimate the effect of the miR-21 inbihitor and miR-494 mimic on the proliferation of A375 cells.Methods A miR-21 inbihitor and a miR-494 mimic were designed and constructed.To optimize the concentration of the miR-21 inbihitor and miR-494 mimic for transfection,six concentrations (70-250 nmol/L) of the inbihitor and mimic were transfected into A375 cells separately by using LipofectamineTM2000.Then,quantitative fluorescence-based PCR was performed to determine the expression of miR-21 and miR-494 in A375 cells.Some A375 cells were classified into five groups:Mock blank control group remaining untransfected,miR-21 inhibitor group transfected with the miR-21 inhibitor,miR-21 control group transfected with the miR-21 inhibitor negative control,miR-494 mimic group transfected with the miR-494 mimic,and miR-494 control group transfected with the miR-494 mimic negative control.Mter another 48-hour culture,the cells were collected for the analysis of cell apoptosis and cycle by using flow cytometry.Meanwhile,Cy5-labelled miR-494 mimic negative control was transfected into A375 cells for the evaluation of the transfection efficiency by using an inverted fluorescence microscope.Results miRNAs were successfully extracted from A375 cells.As quantitative PCR revealed,the A375 cells transfected with the miR-21 inhibitor at 120 nmol/L showed the lowest expression level (2-△△Ct) of miR-21 (average:0.80; range:0.65-0.92),and those transfected with the miR494 mimic at 250 nmol/L displayed the highest expression level of miR-494 (average:126.82; range:111.52-144.22).The transfection efficiency in A375 cells was higher than 90％.Compared with the corresponding negative control groups,the miR-21 inhibitor group and miR-494 mimic group showed increased apoptosis rate ((27.74 ± 1.39)％ vs.(12.93 ± 0.65)％,(34.30 ± 2.35)％ vs.(15.54 ± 1.02)％,both P ＜ 0.01),percentage of G1-phase cells ((61.61 ± 3.25)％ vs.(50.34 ± 5.62)％,(61.05 ± 3.17)％ vs.(49.95 ± 2.58)％,both P＜ 0.05),but decreased proliferation index ((38.39 ± 3.25)％ vs.(49.66 ± 5.62) ％,(38.95 ± 3.17)％ vs.(50.05 ± 2.58)％,both P ＜ 0.05).Conclusions Both the miR-21 inhibitor and miR-494 mimic can promote the G1-phase arrest and apoptosis in A375 cells,and miR-21 may act as a protooncogene accelerating the proliferation of A375 cells,while miR-494 may founction as a tumor suppressor inhibiting the proliferation of A375 cells.