维生素K3诱导人肝癌细胞SMMC-7721损伤中Bcl-2和Bax表达的变化及意义

目的：探讨Bcl-2、Bax在维生素K3 (VK3)诱导人肝癌细胞SMMC-7721损伤过程中的变化，为研究VK3诱导肝癌细胞损伤的机制提供参考。方法：体外培养SMMC-7721细胞，取对数生长期细胞分为对照组和不同浓度VK3处理的实验组（20、40和60 μmol?L^-1），MTT法检测各组SMMC-7721细胞生存率；紫外分光光度法检测乳酸脱氢酶(LDH)释放率；RT-PCR检测Bcl-2及Bax mRNA表达水平；Western blotting检测Bcl-2及Bax蛋白表达水平。结果：与对照组比较，20 μmol?L^-1 VK3组细胞存活率、LDH释放率、Bcl-2和Bax mRNA表达量及其蛋白表达量未见明显变化；与对照组比较，40和60 μmol?L^-1 VK3组细胞存活率降低(P<0.05或P<0.01)；LDH释放率增加(P<0.05或P<0.01)；Bcl-2 mRNA表达率降低(P<0.05)；Bax mRNA表达量率升高(P<0.05)；Bcl-2蛋白表达水平下降(P<0.05)；Bax 蛋白表达水平升高(P<0.05)。结论：40 μmol?L^-1剂量的VK3能够诱导SMMC-7721细胞损伤，其机制可能与下调Bcl-2和上调Bax蛋白表达有关。

Changes of Bcl-2 and Bax on vitamin K3 induced injury in human hepatocarcinoma SMMC-7721 cells

Objective To investigate the changes of Bcl-2 and Bax expressions on human hepatocarcinoma SMMC-7721 cells injuried with vitamin K3(VK3) treatment and provide information for further research of its mechanism.Methods SMMC-7721 cells were cultivated in vitro,then were divided into control group and experimental groups treated with different concentrations of VK3(20,40 and 60 μmol·L-1).The viability of SMMC-7721 cells treated with VK3 was measured by MTT assay,LDH release rate was detected by ultraviolet spectrophotometry,the expressions of Bcl-2 and Bax mRNA were determined using RT-PCR,the expressions of Bcl-2 and Bax protein were assayed by using Western Blotting.Results Compared with control group,20 μmol·L-1 VK3 did not induce significant changes of cell viability,LDH release rate,the expressions of Bcl-2 and Bax mRNA,the expressions of Bcl-2 and Bax protein.In 40 and 60 μmol·L-1VK3 groups the cell viabilities decreased(P<0.05 or P<0.01),the LDH release rates increased (P<0.05 or P<0.01),the expressions of Bcl-2 mRNA decresed(P<0.05),the expressions of Bax mRNA increased(P<0.05),the expressions of Bcl-2 protein decresed,the expression of Bax protein increased compared with control group.Conclusion 40 μmol·L-1 VK3 can induce SMMC-7721 cell injury,its mechanism may be related to down-regulation of Bcl-2 protein expression and up-regulation of Bax protein expression.