摘要:
目的 探讨靶向沉默DEK对肝癌细胞株增殖及细胞周期的影响.方法 常规培养人肝癌细胞株HepG2,待细胞生长至90%融合度时分为空白对照组、小分子干扰RNA (siRNA)对照组和DEK siRNA组.空白对照组细胞正常培养,不做任何处理;siRNA对照组和DEK siRNA组细胞分别在LipofectamineTM 2000脂质体介导下进行siRNA表达载体和DEK siRNA表达载体转染.应用实时定量聚合酶链反应检测HepG2细胞中DEK mRNA的表达,免疫蛋白印迹法检测HepG2细胞中DEK、CyclinD1蛋白的表达,四甲基偶氮唑盐法检测HepG2细胞增殖情况,流式细胞术观察细胞周期变化.结果 空白对照组、siRNA对照组和DEK siRNA组HepG2细胞中DEK mRNA表达分别为0.826±0.052、0.776±0.051、0.420±0.050,DEK蛋白表达分别为0.691±0.073、0.726±0.061、0.311±0.038,Cy-clinD1蛋白表达分别为0.712±0.069、0.780±0.074、0.434±0.039;DEK siRNA组HepG2细胞中DEK mRNA及DEK、CyclinD1蛋白表达均低于空白对照组和siRNA对照组(P<0.05);空白对照组和siRNA对照组HepG2细胞中DEK mRNA及DEK、CyclinD1蛋白表达比较差异均无统计学意义(P<0.05).DEK siRNA组转染后24、48、72、96、120 h时细胞增殖能力均低于空白对照组和siRNA对照组(P<0.05);空白对照组和siRNA对照组各时间点细胞增殖能力比较差异均无统计学意义(P<0.05).DEK siRNA组Go+G1期细胞所占比例高于空白对照组和siRNA对照组(P<0.05);DEK siRNA组S期、G2 +M期细胞所占比例均低于空白对照组和siRNA对照组(P<0.05);空白对照组和siRNA对照组G0+G1期、S期、G2 +M期细胞所占比例比较差异无统计学意义(P<0.05).Pearson相关分析显示,CyclinD1蛋白表达与DEK mRNA和DEK蛋白表达均呈正相关(r=0.909、0.899,P<0.05).结论 DEK siRNA可下调HepG2细胞中DEK基因表达,抑制HepG2细胞增殖,改变细胞周期分布,这一过程可能与下调CyclinD1表达有关.%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.