低浓度乙醇诱导与紫外线照射对HepG2细胞周期及p53/p21蛋白表达的影响

目的观察低浓度乙醇诱导与紫外线照射导致HepG2肝癌细胞损伤的分子路径。方法选用HepG2肝癌细胞株，分别给予低浓度乙醇诱导与紫外线照射处理，观察两种损伤因素作用后细胞周期分布的差异，细胞中p53蛋白和p21蛋白表达的改变，分析蛋白表达与细胞周期改变的关系。结果紫外线照射后细胞中p53、p21蛋白表达均明显增强，出现G0～G1／G2～M期阻滞；低浓度乙醇诱导后主要出现G2～M期阻滞与p21蛋白表达的增强，p53蛋白表达改变不明显；两种损伤因素均能导致细胞凋亡率的增加。结论低浓度乙醇诱导与紫外线照射通过激活细胞内不同的分子事件，导致细胞周期与细胞凋亡的改变。

Effects of induction with low concentration of ethanol and ultraviolet irradiation on cell cycle and the expression of p53 and p21 in HepG2 cell line

Objective To study the possible molecular mechanism of the damage of HepG2 cell line induced by low concentration of ethanol and ultraviolet irradiation. Methods Hepatoma cell line (HepG2) was exposed to low concentration of ethanol and ultraviolet irradiation, then the changes in cell cycle, the expression of p53 and p21, the correlation between expression of p53 and p21 and cell cycle were analyzed. Results The expression of p53 and p21 was greatly increased, and the cell cycle was found to be blocked at G_0-G_1/G_2-M after ultraviolet irradiation. The cell cycle block of G_2-M and the increased expression of p21 were observed when exposed to low concentration of ethanol, while the expression of p53 showed no significant changes. Cell apoptosis was increased when the cells were exposed to the both injury factors. Conclusion Low concentration of ethanol and ultraviolet irradiation can affect cell cycle and the process of cell apoptosis through activation of different molecular mechanism.