Co-localization of heat shock protein 72 and CD44v6 in human colonic adenocarcinoma

Background: CD44v6 is a splice variant of CD44 (CD44v) could probably promote cancer cells to adhere to vascular endothelium and base membranes and enhancing the invasion and metastasis of colonic carcinomas. Heat shock protein 72 (HSP72) as a molecular chaperone has been confirmed to overexpress in epithelial carcinoma cells. There may be a possible correlation between the expression of HSP72 and CD44v6 during the growth and differentiation of colonic carcinoma cells. The purpose of the study was to investigate the interaction between heat shock protein 72 and CD44v6 in human colonic carcinomas. Material/Methods: The localization of HSP72 and CD44v6 in human colonic carcinomas was determined by immunohistochemistry and confocal laser microscopy. The interaction between HSP72 and CD44v6 in colonic carcinoma cells was analyzed by immunoprecipitation and Western immunoblots. Results: Colonic carcinoma synchronously co-expressed higher level of HSP72 and CD44v6 than in adjacent normal colonic tissues. HSP72 were stained in cell cytoplasm, while CD44v6 mainly stained in cell plasma and membrane respectively. Based on Western blotting methods, CD44v6 was detected in the immunoprecipitate of anti-HSP72 monoclonal antibody (mAb), while HSP72 existed in the immunoprecipitate of anti-CD44v6 mAb. Conclusions: HSP72 and CD44v6 expression are higher in colonic carcinoma tissues. HSP72 was associated with CD44v6 in human colonic carcinoma cells. The interaction between HSP72 and CD44v6 in human colonic carcinoma cells can be a new route for studying the pathogenesis and immunotherapy of colonic carcinoma.