Effect of DEK targeting silence on proliferation and cell cycle of human hepatoma HepG2 cells / 新乡医学院学报

ABSTRACT

Objective To study the influence of targeted silencing of DEK on the proliferation and cell cycle of human hepatoma cell lines.Methods The human hepatoma cells line HepG2 were routinely cuhured and the cells were divided into blank control group,siRNA control group and DEK siRNA group when the cells grew to 90％ tusion.The cells in blank control group were cultured normally without any treatment;the cells in siRNA control group and DEK siRNA group were transfected with siRNA expression vector and DEK siRNA expression vector mediated by LipofectamineTM2000 liposomes,respectively.The expression of DEK mRNA in HepG2 cells was detected by real-time polymerase chain reaction;the expression of DEK and CyclinD1 protein in HepG2 cells was detected by Western blot;the proliferation of HepG2 cells was detected by methyl thiazolyl tetrazolium method,and the cell cycle was observed by flow cytometry.Results The expression of DEK mRNA in the blank control group,siRNA control group and DEK siRNA group was 0.826 ±0.052,0.776 ±0.051 and 0.420 ±0.050 respectively;the expression of DEK protein in the blank control group,siRNA control group and DEK siRNA group was 0.691 ± 0.073,0.726±0.061 and 0.311 ±0.038 respectively;the expression of CyclinDl protein in the blank control group,siRNA cuntrol group and DEK siRNA group was 0.712 ± 0.069,0.780 ± 0.074 and 0.434 ± 0.039 respectively.The expressions of DEK mRNA,DEK protein and CyclinD1 protein in DEK siRNA group were significantly lower than those in the blank control group and siRNA control group (P ＜ 0.05);there was no statistic difference in the expression of DEK mRNA,DEK protein and CyclinD1 protein between the blank control group and siRNA control group(P ＜0.05).The proliferation ability of HepG2 cells in DEK siRNA group after transfection of 24,48,72,96,120 h was significantly lower than that in the blank control group and siRNA control group(P ＜0.05);there was no statistic difference in the proliferation ability of HepG2 cells between the blank control group and siRNA control group at each time point(P ＜ 0.05).The proportion of G0 + G1 phase cells in DEK siRNA group was significantly higher than that in the blank control group and siRNA control group(P ＜ 0.05);the proportions of S phase and G2 + M phase cells in DEK siRNA group were significantly lower than those in the blank control group and siRNA control group(P ＜ 0.05);there was no statistic difference in the proportion of G0 + G1 phase,S phase and G2 + M phase cells between the blank control group and siRNA control group (P ＜ 0.05).The result of Pearson correlation analysis showed that the expression of CyclinD1 protein was positively correlated with the expression of DEK mRNA and protein(r =0.909,0.899;P ＜ 0.05).Conclusion DEK siRNA can inhibit the proliferation of HepG2 cells,and change the cell cycle distribution through down regulating the expression of DEK gene in HepG2 cells.This process may be related to the down regulation of the expression of CyclinD1.