原癌基因c-jun、c-fos与人膀胱癌耐药细胞株谷胱甘肽及其多药耐药基因表达的关系

Relationship between the Expression of Oncogene c-jun,c-fos and the Expression of Glutathion, GSH-related Drug Resistance Genes in Durg-resistant Human Bladder Cancer Line

目的 研究原癌基因c jun和c fos的表达对谷胱甘肽介导的膀胱癌多药耐药的影响。方法 应用定量逆转录聚合酶链反应 (RT PCR)技术和蛋白免疫印迹法 (WesternBlotting) ,检测c jun、c fos基因在人膀胱癌细胞株BIU87及其阿霉素诱导的多药耐药亚株BIU87/A的表达 ,并分析其与两株细胞的GSH生物合成的限速酶———γ 谷氨酰半胱氨酸合成酶 (γ GCS)表达和细胞内谷胱甘肽 (GSH)水平的关系。同时还应用以上方法检测谷胱甘肽S 转移酶 π (GST π)和多药耐药相关蛋白 1(MRP1)在BIU87和BIU87/A的表达。结果 BIU87/A相对于BIU87具有多药耐药特性 ,其γ GCSmRNA的相对表达水平明显高于BIU87(1 341vs 0 95 3,P <0 0 5 ) ,与此相应 ,BIU87/A细胞内GSH水平也高于BIU87(P <0 0 1) ;c jun基因mRNA及其蛋白在BIU87/A的表达均高于BIU87,而c fos基因在BIU87和BIU87/A的表达未见明显差异 (P >0 0 5 ) ;GST π和MRP1在BIU87/A表现高表达。结论 原癌基因c jun过表达可上调BIU87/A细胞的GSH水平及其耐药相关基因的表达 ;c fos可能对BIU87/A的耐药形成并不起主要作用。

Objective To investigate the roles of expression of oncogene c jun and c fos in glutathion (GSH)-mediated multidrug resistance in human bladder cancer cell. Methods The expression of c jun and c-fos in human bladder cell line BIU87 and adriamycin (ADM) induced resistant subline BIU87/A was detected by quantitative reverse transcription polymerase (RT PCR) and Western blotting. The relationship between the expression of oncogenes (c jun and c fos) and g-glutamylcysteine synthetase catalytic subunit (γ GCSh) gene and intracellular GSH levels were analyzed. Meanwhile, two GSH related drug resistance genes GSH S transferase π (GST π) and multidrug resistance-associated protein 1 (MRP 1) in both cell lines were examined by the same assay as above. Results In comparison with parental cell line, BIU87/A showed various degrees of the phenotype of multidrug resistance to chemotherapy agents; The relative expression of γ GCS mRNA and the intracellular GSH level in BIU87/A were significantly higher than those in BIU87 ( P <0.05; P <0.01); There was a higher expression of c jun mRNA and protein in BIU87/A than that in BIU87, but no difference in c fos was found in both cell lines. The expression of GST π and MRP 1 at the levels of mRNA and protein in BIU87/A cells was higher than that in BIU87 cells. Conclusion Oncogene c jun can upregulates the intracellular GSH content and the expression of some GSH related resistance genes in resistant bladder cancer cells by the inhibition of GSH biosynthesis, which can contribute to the acquisition of drug resistance of bladder cancers; c jun has probably a minor role in the resistance of BIU87/A.