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目的 探讨二氢杨梅素对卡铂耐药恶性黑素瘤细胞的增敏作用并研究其机制.方法 MTT法检测卡铂耐药A375细胞(A375-R)在卡铂和二氢杨梅素处理下的细胞活力.Western blot法检测卡铂和二氢杨梅素对A375-R细胞SIRT1表达水平,caspase-9、caspase-3活化水平及JNK蛋白磷酸化水平的影响.流式细胞术检测A375-R细胞在卡铂和二氢杨梅素联合处理下的细胞凋亡率.结果 MTT实验结果显示,卡铂对A375-R细胞的半数抑制浓度(IC50)显著高于A375细胞,二氢杨梅素辅助治疗能明显降低卡铂对A375-R的IC50.Western blot实验结果显示A375-R中SIRT1的表达水平显著高于A375细胞,二氢杨梅素处理能显著抑制A375-R细胞SIRT1的表达.二氢杨梅素能明显促进卡铂对A375-R细胞JNK的磷酸化,转染SIRT1质粒或用JNK特异性抑制剂(SP600125)处理后,二氢杨梅素联合卡铂对A375-R细胞的杀伤活性、凋亡诱导活性和JNK、caspase-9及caspase-3的活化均受到明显抑制.结论 二氢杨梅素通过SIRT1/JNK途径提高耐药恶性黑素瘤细胞对卡铂的敏感性.“,”OBJECTIVE To investigate the effect and mechanisms of dihydromyricetin treatment on sensitizing carboplatin-resistant melanoma to carboplatin treatment.METHODS MTT assay was performed to evaluate the effect of dihydromyricetin and carboplatin on inhibiting the viability of carboplatin-resistant A375 (A375-R) cells.Western blot analysis was performed to detect the expression of SIRT1,activation of caspase-9 and caspase-3,and phosphorylation of JNK in the A375-R cells treated with dihydromyricetin and carboplatin.Flow cytometry analysis was performed to measure the cell apoptosis of A375-R cells treated with dihydromyricetin and carboplatin.RESULTS Results of MTT assays showed that IC50 of carboplatin to A375-R was significantly higher than the A375 cells.Dihydromyricetin treatment was able to decrease the IC50 of carboplatin to A375-R.Results of Western blot analysis showed that expression level of SIRT1 in A375-R cells was significantly higher than that in the A375 cells.Dihydromyricetin decreased the expression of SIRT1 in A375-R.Dihydromyricetin promoted phosphorylation of JNK in A375-R cells treated with carboplatin.After transfection with SIRT1 plasmid or pretreatment with JNK specific inhibitor SP600125,dihydromyricetin plus carboplatin-induced cytotoxicity,apoptosis,activation of JNK,caspase-9 and caspase-3 was significantly suppressed.CONCLUSION Dihydromyricetin sensitizes drug-resistant melanoma cells to carboplain through the SIRT1/JNK pathway.