氢醌染毒对红白血病细胞株K562细胞周期的影响及其机制

Effect of hydroquinone on cell cycle of erythroleukemia cell line K562

目的探讨氢醌(HQ)对红白血病细胞株K562细胞周期的影响及其作用机制。方法取生长至对数期时K562细胞,设空白对照组及HQ染毒低剂量组、中剂量组、高剂量组,分别以HQ终浓度为0、15、30、60μmol/L处理,各实验组间隔处理72 h后,流式细胞术检测细胞周期分布,免疫印迹法检测CDC25A、CDK2、Cyclin E、Cycli-n A、p53、p21、PCNA等细胞周期相关蛋白表达。结果空白对照组及HQ染毒低剂量组、中剂量组、高剂量组G0/G1期细胞所占比例分别为55. 90%±2. 71%、40. 16%±3. 34%、29. 97%±1. 23%、32. 84%±0. 93%,S期细胞比例分别为43. 42%±2. 61%、57. 01%±3. 50%、66. 87%±1. 77%、66. 66%±0. 31%,G2/M期细胞比例分别为0. 73%±0. 78%、3. 27%±2. 05%、4. 40%±5. 07%、0. 18%±1. 54%,与空白对照组比较,各染毒剂量组G0/G1细胞比例下降,S期细胞比例增加(P <0. 05),G2/M期细胞差异无统计学意义(P> 0. 05)。与空白对照组比较,CDC25A蛋白表达在HQ染毒各剂量组降低(P <0. 05),HQ染毒各剂量组间高剂量组<中剂量组<低剂量组(P <0. 05)。与空白对照组比较,Cyclin E、PCNA蛋白表达在HQ染毒低剂量组差异无统计学意义,在中、高剂量组表达量降低(P <0. 05),HQ染毒各剂量组间高剂量组<中剂量组<低剂量组(P <0. 05)。与空白对照组比较,p53蛋白在HQ染毒低、中剂量组表达量增高(P <0. 05),在高剂量组表达差异无统计学意义,HQ染毒各剂量组间高剂量组<中剂量组<低剂量组(P <0. 05)。CDK2、Cyclin A和p21蛋白在空白对照组与HQ染毒各剂量组间的表达差异无统计学意义(P> 0. 05)。结论 HQ致K562细胞周期发生S期阻滞,可能与其下调CDC25A、Cyclin E、PCNA蛋白表达有关。

Objective To investigate the effect of hydroquinone(HQ)on the cell cycle of erythroleukemia cell line K562 and its mechanism.Methods K562 cells in the logarithmic phase were selected and then divided into the blank control group and HQ-treated low-dose group,medium-dose group and high-dose group which were treated with 0,15,30,and 60μmol/L HQ for 72 h at intervals and repeatedly.After 72 h,the cell cycle distribution was detected by flow cytometry,and cell cycle-related protein expression such as CDC25A,CDK2,CyclinE,CyclinA,p53,p21 and PCNA was detected Western blotting.Results The results of flow cytometry showed that the ratio of cells in the G 0/G 1 phase of the blank control group and low-dose,medium-dose and high-dose HQ groups was 55.90%±2.71%,40.16%±3.34%,29.97%±1.23%,and 32.84%±0.93%,and the ratio of cells in the S phase was 43.42%±2.61%,57.01%±3.50%,66.87%±1.77%,and 66.66%±0.31%,and the ratio of cells in the G 2/M phase was 0.73%±0.78%,3.27%±2.05%,4.40%±5.07%,and 0.18%±1.54%,respectively.Therefore,HQ could decrease the proportion of cells in the G 0/G 1 phase in the K562 cell cycle(P<0.05),increase the proportion of cells of the S phase(P<0.05),and induce S phase arrest.Western blotting showed that compared with the blank control group,the expression of CDC25A protein decreased in each HQ dose group(P<0.05),and the expression of the high-dose to medium-dose and low-dose HQ-groups decreased(P<0.05).Compared with the blank control group,the expression of CyclinE and PCNA protein in the low-dose group was not statistically different,but the expression in the medium-dose and high-dose HQ groups decreased(P<0.05).The expression of CyclinE and PCNA protein from the high-dose group to medium-does group and low-dose groups decreased in turn after exposure of HQ(P<0.05).Compared with the blank control group,the expression of p53 protein in the low-does and medium-dose groups increased(P<0.05),and the difference in the high-dose group was not statistically significant.There was no significant difference in the expression of CDK2,CyclinA or P21 protein between the blank control group and HQ dose groups(all P >0.05).Conclusion HQ can induce S phase arrest in K562 cells which might be related to the down-regulated expression of CDC25A,CyclinE,and PCNA.