在癌细胞中下调皮质肌动蛋白使细胞内吞作用减弱  

Attenuated endocytosis by down-regulation of cortactin protein in cancer cells

作　　者：陈莉[1] 朱建伟[2] Zhan Xi 

机构地区：[1]南通大学医学院病理教研室,江苏南通226001 [2]南通大学 附属医院普外科,江苏南通226001 [3]UMBGreenebaum肿瘤中心,马里兰州21450,美国

出　　处：《基础医学与临床》2008年第6期579-582,共4页Basic and Clinical Medicine

基　　金：江苏省教育厅高新技术发展项目(JH02-118)

摘　　要：目的探讨皮质肌动蛋白（Cort）对高表达Cort的乳腺癌细胞系（MDA—MB-231细胞）细胞内吞作用的影响。方法在MDA—MB-231细胞中使用CortsiRNA干预技术和“生物搬运法”系统将抗Cort免疫抗体（Cort多克隆抗体001或单克隆Cort抗体4F11）引入MDA-MB-231细胞，进行体内干预Cort功能。根据捕获ELISA法分析转铁蛋白摄入，免疫印迹分析细胞中Cort敲除的程度和免疫荧光直接检测评价Cort在转铁蛋白吸收中的作用。结果免疫印迹分析在CortsiRNA处理过的细胞质中未测出Cort蛋白；用荧光标记评价转铁蛋白密度水平，在CortsiRNA处理的细胞中要低于含相对高水平Cort的对照组细胞；在接受CortsiRNA处理后仅50％的MDA-MB-231细胞中有转铁蛋白摄入；在MDA—MB-231细胞中引入001或4F11抗体，其细胞的内吞作用减弱，导致明显的转铁蛋白吸收减少30％～60％。结论干扰Cort的功能或直接使用抗Cort抗体进行干预都能抑制细胞内吞作用。Cort是细胞内吞作用中必不可少的成分，具有重要作用。Objective siRNA interference to To study cortactin function in cancer cell endocytosis. Methods We applied cortactin MDA-Mb-231, a human breast adenocarcinoma cell line in which cortactin was over-expressed, and introduced anti-cortactin immunoreagents into the cells with BioPorter system to interfere with cortactin function in vivo. Capture -ELISA assay was used to measure transferrin uptake. We used immunoblot assay to assess the effect of cortactin knock-down and immunoflurescence microscopy to examine the effect of cortactin downregulation on transferrin uptake. Results Interference of cortactin function in cells resulted in impairment of transferrin endocytosis. Transferrin fluorescent intensity in cytoplasm in cortactin siRNA treated-cells was significantly reduced in comparison to that of mock-treated cells. Less than 50% of cells subjected to cortactin siRNA treatment had normal transferrin uptake. Endocytosis in MDA-Mb-231 cells introduced with cortactin antibodies was impaired as well, showing a 30% - 60% reduction in transferrin uptake. Conclusion Crtactin, an actin-binding protein, plays an essential role in cell endocytosis.

关 键 词：皮质肌动蛋白(Cort) 细胞内吞作用 SIRNA 转铁蛋白 

分 类 号：R73-3[医药卫生—肿瘤]