Specific expression of HSP47 in human tumor cell lines in vitro.

HSP47 is a stress-inducible glycoprotein of 47 kd molecular weight, and is assumed to be a collagen specific molecular chaperone. The expression of HSP47 is closely related to that of collagen, which is the main component of the extracellular matrix. We investigated the expression level of HSP47 in human tumor cell lines to elucidate collagen biosynthesis in tumor cells. Western blot analysis showed higher levels of HSP47 in solid tumor cell lines than in leukemia cell lines. Tumor cell lines which were derived from metastatic carcinomas and were still metastatic in animals, synthesized higher levels of HSP47. These results suggested that HSP47 may play an important role in tumor metastasis and can be a prognostic marker for the metastatic activity of human tumor cells.