热休克同源蛋白73与CXCR4在肾癌A498细胞核内相互作用

Interaction of Hsc73 with CXCR4 in nuclei of renal cell carcinoma A498 cells

目的研究热休克同源蛋白73(heat shock cognate protein73000,Hsc73)在基质细胞衍生因子1(SDF-1)/趋化因子CXC受体4(CXCR4)轴促进肾癌转移中的作用,确定Hsc73是否参与了CXCR4的核定位。方法通过蛋白电泳观察CXCR4高表达后Hsc73在A498细胞中的表达情况。通过免疫染色、核蛋白免疫共沉淀等方法观察A498细胞在经过SDF-1刺激后Hsc73在细胞内表达情况,以及Hsc73与CXCR4结合情况。结果 CXCR4高表达后,A498细胞中Hsc73表达明显增高。Hsc73主要表达在A498细胞胞质中,在SDF-1刺激后出现部分转移至细胞核。提取SDF-1刺激后的A498细胞核蛋白进行CXCR4免疫共沉淀,其中发现了Hsc73。结论 Hsc73作为细胞内常见的分子伴侣蛋白,参与了CXCR4在细胞中的转运。对于SDF-1/CXCR4信号通路激活的部分环节起到了关键作用,并可能参与了CXCR4核转位的过程。

Objective To investigate the role of protein Hsc73（heat shock cognate protein 73 000）in renal cell cancer metastasis promoted by SDF-1/CXCR4 axis,so as to determine whether Hsc73 participates in CXCR4 nuclear localization.Methods Western blotting analysis was used to observe the expression of Hsc73 in A498 cells over-expressing CXCR4.The location of Hsc73 and the interaction of CXCR4 with Hsc73 were investigated in SDF-1-stimulated A498 cells by immunohistochemical staining,Co-IP（Co-Immunoprecipitation）experiment,etc.Results Hsc73 was up-regulated in A498 cells over-expressing CXCR4.Hsc73 was mainly found in the cytoplasm of A498 cells;after stimulation with SDF-1,some Hsc73 appeared in the nuclei.Hsc73 protein was found in the nuclei of A498 cells after Co-IP with anti-CXCR4 antibody.Conclusion Hsc73 as a common molecular chaperone participates in the intra-cellular translocation of CXCR4;Hsc73 also plays a key role in the activation of SDF-1/CXCR4 signal pathway and may be involved in the nuclear translocalization of CXCR4.