摘要
目的 研究核因子 κB(NF κB)在胃癌耐药形成中的作用。方法 应用凝胶电泳迁移率分析研究长春新碱 (VCR)对胃癌细胞SGC790 1及耐药细胞SGC790 1/VCR内NF κBDNA结合活性的影响 ,细胞 ELISA法检测细胞内NF κB抑制因子IκB α蛋白的表达 ,免疫细胞化学法观测细胞内 p6 5核转位 ,MTT法检测细胞对药物的敏感性。结果 SGC790 1/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、2 0、5 0 μg/L)均可引起耐药细胞NF κBDNA结合活性增强 ,同时伴有IκB α蛋白表达下降和 p6 5核转位 ,亲本敏感细胞产生的上述效应均不及耐药细胞明显。与敏感细胞相比 ,10 μg/LVCR作用不同时间时 ,SGC790 1/VCR细胞中NF κB活性上升速度慢但维持时间长。NF κB抑制剂MG 132可抑制VCR诱导的NF κB活化 ,IκB α降解和 p6 5核转位 ,并提高耐药细胞对VCR的敏感性。结论 NF κB活性增强参与胃癌细胞对VCR耐药。
Objective To investigate the effect of activation of nuclear factor- κB (NF-κB)in vincristine VCR-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) were measured by cellular-ELISA. Immunocytochemistry was used to detect the translocation of p65, and cell survival rates were determined by the MTT assay. Results Compared with the parent SGC7901 cells, the basal and VCR-induced NF-κB-DNA binding activity at various concentration were all higher in the SGC7901/VCR cells. The duration of high NF-κB-DNA binding activity in SGC7901/VCR cells was longer than that of SGC7901, although it showed less rapid response to VCR treatment. Concurrent with the NF-κB activation, VCR-induced IκB-α degradation and nuclear translocation of p65 were also found to be highly enhanced in the SGC7901/VCR cells than those of the sensitive SGC7901 cells. Furthermore, the inhibition of NF-κB by MG-132, a proteasome inhibitor, could reduce NF-κB activation, IκB-α degradation and p65 translocation. It also could enhance the chemosensitivity of SGC7901/VCR to VCR. Conclusion The data indicate that enhancement of NF-κB activation correlates with the VCR resistance in gastric cancer cells.
出处
《中华消化杂志》
CAS
CSCD
北大核心
2004年第8期472-475,共4页
Chinese Journal of Digestion
