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

1.为了研究调控顺铂耐药获得的分子，我们利用两对亲本和顺铂耐药的膀胱癌细胞系进行了基因芯片的研究。我们发现，在顺铂耐药细胞中，内质网膜蛋白--肌醇1，4，5-三磷酸受体类型(IP3R1)的表达显著降低。在亲本细胞中使用小干扰RNA抑制IP3R1的表达可阻止细胞凋亡，并导致对顺铂的敏感性降低。反之，IP3R1在耐药细胞中过表达可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获得顺铂耐药性密切相关。2.P-糖蛋白/多药耐药相关蛋白(MDR1)和多药耐药相关蛋白(MRP)基因的过度表达与包括阿霉素在内的一些化疗药物的耐药性有关。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，并探讨了这些基因的表达与多柔比星疗效的相关性。多柔比星治疗后mdr1、mrp1、mrp2、mrp3基因表达水平均高于治疗前。我们还发现mdr1、mrp1和mrp3基因水平与阿霉素耐药性显著相关。这些数据表明，mdr1、MRP1和MRP3mRNA水平与阿霉素的疗效相关。

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.