HSP47 as a possible marker for malignancy of tumors in vivo.

We have developed a rat monoclonal antibody against mouse HSP47 (designated as NK47) and investigated the expression of HSP47 in several mouse ascites and solid tumors. The expression of HSP47 was not detected in ascites tumors such as P388 and Ehrlich ascites tumors while HSP47 was markedly expressed in solid tumors such as Colon-26, B16 and B16-BL6 melanomas. HSP70, HSC70 and HSP90 were expressed in almost the same level among all the tumors examined. These results suggest that the expression of HSP47 decreases as the tumor becomes more malignant.