中文摘要：

[目的]探讨葡萄糖-6-磷酸脱氢酶（G6PD）缺陷对苯醌（BQ）染毒人慢性髓性白血病（K562）细胞毒性的影响。[方法]用不同浓度的BQ（0、10、20、40μmol/L）处理野生型K562细胞,应用MTT比色法检测BQ对受试细胞的增殖抑制作用,Western blot法检测G6PD蛋白表达的变化。构建G6PD-set RNA干扰慢病毒,并感染野生型K562细胞株;以转染空载体的野生型K562细胞作为阴性对照细胞,荧光实时定量-聚合酶链反应（real-time PCR）法检测G6PD基因的m RNA表达量。再用不同浓度的BQ处理G6PD缺陷的K562-WT细胞（K562-G6PD△）和阴性对照细胞,检测细胞增殖抑制作用,比色法检测细胞中还原型谷胱甘肽（GSH）和氧化型谷胱甘肽（GSSG）水平。[结果]MTT结果表明,与BQ浓度为0μmol/L组相比,10、20、40μmol/L的BQ作用24、48、72 h后,野生型K562细胞相对增殖率均明显降低（P〈0.05）。Western blot结果显示,低剂量下（BQ浓度〈40μmol/L时）随着BQ浓度的增加,G6PD蛋白含量亦增加（r=0.809,P=0.008）;当BQ浓度升至40μmol/L时,G6PD蛋白含量有所下降,但仍高于BQ浓度为0μmol/L组（P〈0.05）。real-time PCR法检测结果显示,K562-G6PD△细胞的G6PD m RNA表达量较阴性对照降低了86.65%,表明K562-G6PD△细胞构建成功。干预G6PD后,MTT结果表明,与阴性对照细胞相比,K562-G6PD△细胞暴露于不同浓度BQ后,其相对增殖率均明显降低（P〈0.05）。比色法结果表明,当BQ浓度为20、40μmol/L时,K562-G6PD△细胞中GSH浓度明显降低,而在阴性对照细胞中,当BQ浓度为40μmol/L时GSH浓度明显降低;当BQ浓度为10μmol/L时,较阴性对照细胞相比,K562-G6PD△细胞中GSSG浓度显著升高（P〈0.05）。[结论]野生型K562细胞暴露于BQ后细胞增殖受抑制,氧化产物增加的同时可能通过激活G6PD等抗氧化系统以抵抗机体所受的氧化损伤;而G6PD缺陷后,由于G6PD不能被激活,在暴露于较低剂量的BQ时即可使细胞内GSH

英文摘要：

[Objective] To evaluate the effects of glucose-6-phosphate dehydrogenase（G6PD） deficiency on the cytotoxicity of benzoquinone（BQ） on K562 cells.[Methods] After treatment with different concentrations of BQ（0,10,20,and 40 μmol/L）,MTT assay was used to detect the relative growth rate of K562-WT cells,and Western blot assay was used to measure the protein expression level of G6 PD.RNA interference lentivirus targeting G6 PD gene was constructed and transfected into K562-WT cells,while negative control group was transfected with empty vector.Quantitative real-time polymerase chain reaction（real-time PCR） was applied to measure the m RNA expression of G6 PD.MTT assay and colorimetric assay were used to detect the relative growth rate as well as reduced glutathione（GSH） and oxidized glutathione（GSSG） in G6 PD defective K562-WT cells（K562-G6PD△） and negative control cells after treatment with different concentrations of BQ.[Results] The results of MTT assay indicated that the relative growth rates of K562-WT cells remarkably decreased with higher BQ concentrations compared with 0 μmol/L BQ group（P 〈 0.05） at 24,48,and 72 h.The results of Western blot showed that the G6 PD protein level was increased first（r=0.809,P=0.008） and then decreased when the cells were exposed to 40 μmol/L BQ,but was still higher than that of 0 μmol/L BQ group（P 〈 0.05）.The results of real-time PCR showed the G6 PD m RNA expression of K562-G6PD△ cells was decreased by 86.65% compared with the negative control cells.That suggested K562-G6PD△ cells were successfully constructed.The results of MTT assay indicated that the relative growth rate of K562-G6PD△ cells was remarkably decreased compared with the negative control cells at each concentration of BQ（P 〈 0.05）.The results of colorimetric assay showed that the level of GSH in K562-G6PD△ cells was decreased when exposed to BQ concentrations of 20 and 40 μmol/L,while in the negative control cells the decrease occurred at 40 μmol/L.T