Identification of Drug Resistance Gene by Microarray and Elucidation of Mechanism of Drug Resistance in Urogenital Cancer

1.为了研究调节顺铂耐药获得的分子，我们使用两对亲本和顺铂耐药膀胱癌细胞系进行了cDNA微阵列研究。我们发现在顺铂耐药细胞中肌醇1,4,5-三磷酸受体类型（IP3R1），内质网膜蛋白的表达显著降低。使用小干扰RNA抑制亲代细胞中IP3R1的表达可防止细胞凋亡并降低对顺铂的敏感性。相反，耐药细胞中IP3R1的过表达诱导细胞凋亡并增加对顺铂的敏感性。这些结果表明，顺铂诱导的IP3R1表达下调与膀胱癌细胞顺铂耐药的获得密切相关。p -糖蛋白/多药耐药1（MDR1）和多药耐药相关蛋白（MRP）基因的过度表达与对包括阿霉素在内的一些化疗药物的耐药有关。我们检测了多柔比星治疗前后膀胱癌组织中MDR1、MRP1、MRP2和MRP3基因的表达，并探讨了这些基因表达与多柔比星药物反应的相关性。我们发现，多柔比星治疗后MDR1、MRP1、MRP2、MRP3基因的表达水平均高于治疗前。我们还发现MDR1、MRP1和MRP3 mRNA水平与阿霉素耐药性有显著相关性。这些数据表明，MDR1、MRP1和MRP3 mRNA水平与阿霉素应答相关。

1.To investigate the molecules that regulate the acquisition of cisplatin resistance, we performed cDNA microarrays using two pairs of parental and cisplatin-resistant bladder cancer cell lines. We found a markedly reduced expression of inositol 1,4,5-trisphosphate receptor typel (IP3R1), endoplasmic reticulum membrane protein, in cisplatin-resistant cells. The suppression of IP3R1 expression using small interfering RNA in parental cells prevented apoptosis and resulted in decreased sensitivity to cisplatin. Contrarily, overexpression of IP3R1 in resistant cells induced apoptosis and increased sensitivity to cisplatin. These results suggest that cisplatin-induced downregulation of IP3R1 expression was closely associated with the acquisition of cisplatin resistance in bladder cancer cells.2.Overexpression of the P-glycoprotein/multidrug resistance 1(MDR1) and multidrug resistance-associated protein(MRP) gene is associated with drug resistance to some chemotherapeutic agents including doxorubicin. We determined the expressions of MDR1,MRP1,MRP2,and MRP3 gene in bladder cancer before and after the treatment using doxorubicin and investigated the correlation between the expressions of these genes and drug responses to doxorubicin. We showed that the each level of MDR1,MRP1,MRP2,and MRP3 gene expression after the treatment using doxorubicin was higher than that of gene expression before the treatment. We also found the significant correlation of MDR1,MRP1,and MRP3 mRNA levels with resistance to doxorubicin. These data suggest that MDR1,MRP1,and MRP3 mRNA levels were correlated with the response to doxorubicin.