中文摘要：

葡糖-6-磷酸脱氢酶（G6PD）在许多肿瘤细胞中高表达,但其发生的作用机理目前仍然不明确.以正常人表皮黑色素细胞（HEM）、野生型人黑色素瘤A375细胞（A375-WT）和G6PD缺陷的A375细胞（A375-G6PDΔ）为对象,经real-time PCR、Western印迹和紫外分光光度法分析显示,A375-WT细胞的mRNA、G6PD蛋白和G6PD活性分别是HEM细胞的1.89倍（P〈0.05）、6.86倍（P〈0.01）和2.30倍（P〈0.05）.Annexin V/PI流式细胞仪和Western印迹测定表明,A375-G6PDΔ的凋亡率是A375-WT的5.10倍（P〈0.01）,活化半胱氨酸蛋白酶3（caspase-3）增高1.84倍（P〈0.01）以及89 kD多聚二磷酸腺苷核糖聚合酶-1（PARP-1）生成增加2.87倍（P〈0.01）.分光光度法分析显示,A375-G6PDΔ的NADPH和GSH分别降低了72.30%（P〈0.01）和27.39%（P〈0.05）,并伴有75.43%的H2O2增高（P〈0.01）.结果提示,G6PD在黑色素瘤细胞中高表达和高活性,而敲减G6PD表达通过caspase-3和PARP-1信号诱发人黑色素瘤细胞凋亡,这为深入揭示黑色素瘤的发生机理提供了新思路。

英文摘要：

The mechanism of overexpression of glucose-6-phosphate dehydrogenase（G6PD） in many tumor cells,is no still largely understood.To elucidate the relationship between G6PD and human melanoma,human epidermal melanocyte（HEM）,human melanoma A375（A375-WT） and G6PD deficient A375（A375-G6PDΔ） were used to study the development of cell apoptosis and its mechanism.Real-time PCR and Western blotting showed that mRNA and protein of G6PD in A375-WT cells increased by 1.89 times（P〈0.05） and 6.86 times（P〈0.01）,respectively,with 2.30 times（P〈0.05）increase of G6PD activity,as those of HEM cells.Further study showed that a apoptotic rate increased by 5.10-fold（P〈0.01） in A375-G6PDΔ cells with annexin V /PI flow cytometry analysis,and cleaved caspase-3 and 89 kD PARP-1 raised by 1.84-fold,2.87-fold,respectively.In addition,A375-G6PDΔ cells showed that levels of NADPH and GSH decreased by 72.30%（P〈0.01）,27.39%（P〈0.05）,respectively,with 75.43% increase of H2O2（P〈0.01）,as those of A375-WT cells.These results suggest that the apoptosis induced by G6PD deficiency may be mediated by caspase-3 and PARP-1 in human melanoma cells,which may be a new clue in the study of melanoma tumorigenesis.