摘要
目的:研究核因子-Kappa B(NF-κB)在胃癌长春新碱耐药细胞中的活化情况,及其对细胞膜P-糖蛋白(P-gP)表达的调控作用. 方法:以胃癌细胞SGC7901及其长春新碱(VCR)耐药株SGC7901/VCR为研究对象.采用凝胶电泳迁移率分析检测NF-κB DNA结合活性,细胞-ELISA法检测细胞内1κB- α蛋白和细胞膜P-糖蛋白(P-gp)的表达,免疫细胞化学法观测细胞内P65核转位. 结果:SGC7901/VCR耐药细胞中NF-κB的基础活性比敏感细胞高1.4倍.不同浓度VCR(5,10,20,50 μg/L)均可引起耐药细胞NF-κB DNA结合活性增强、IKB-α蛋白表达下降和P-gp表达增强,而亲本敏感细胞产生的上述效应均不及耐药细胞明显;SGC7901/VCR耐药细胞中, NF-κB活性与P-gp的表达呈正相关(r=0.977,P<0.01), 且NF-κB活化的同时伴有P65核转位.NF-κB抑制剂MG- 132可抑制VCR诱导的NF-κB活化及IKB-α降解,同时还能抑制P-gp高表达. 结论:胃癌长春新碱耐药细胞中NP-κB活性增强,可能参与调控VCR诱导的细胞膜P-gp高表达.
AIM: To investigate the effect of vincristine on activation of nuclear factor-kappa B (NF-κB) and expression of p-glycoprotein (P-gp) in vincristine-resistant human gastric cancer SGC7901 cells (SGC7901/VCR) and the parent sensitive clone (SGC7901). METHODS: NF-κB-DNA binding activity was determined by electrophoretic mobility shift assay (EMSA). Levels of inhibitory κB (IκB-α) and P-gp were measured by cellular-ELISA. And immunocytochemistry was used to detect the translocation of P65. RESULTS: IN comparison with the parent SGC7901 cells, the basal and vincristine-induced NF-κB-DNA binding activity at various concentrations were all higher in the SGC7901/VCR cells. Concurrent with the NF-κB activation, vincristine-induced IκB-α degradation and P-gp upregulation were also found to be highly enhanced in the SGC7901/VCR cells than that in the sensitive SGC7901 cells. In the SGC7901/VCR cells, the activation of NF-κB induced by vincristine showed a positive relation with the level of P-gp expression (r =0.977, [<0.01). And nuclear translocation of P65 occurred concomitantly with NF-κB activation. Furthermore, the inhibition of NP-κB by MG-132, a proteasome inhibitor, could reduce NF-κB activation, IκB-α degradation and P-gp upregulation. CONCLUSION: The enhancement of NF-κB activation correlates with vincristine resistance and NF-κB may play an important role in the regulation of the P-gp expression.
出处
《世界华人消化杂志》
CAS
2004年第3期537-541,共5页
World Chinese Journal of Digestology
