Stromal and epithelial expression of tumor markers hyaluronic acid and HYAL1 hyaluronidase in prostate cancer

Hyaluronic acid (KA), a glycosaminoglycan, regulates cell adhesion and migr ation, Hyaluronidase (HAase), an endoglycosidase, degrades HA into small an giogenic fragments. Using an enzyme-linked immunosorbent assay-like assay, we found increased HA levels (3-8-fold) in prostate cancer (CaP) tissues wh en compared with normal (NAP) and benign (BPH) tissues. The majority (simil ar to 75-80%) of HA in prostate tissues was found to exist in the free form . Primary CaP fibroblast and epithelial cells secreted 3-8-fold more HA tha n respective NAP and BPH cultures, Only CaP epithelial cells and establishe d CaP lines secreted HAase and the secretion increased with tumor grade and metastasis. The pH activity profile and optimum (4.2; range 4.0-4.3) of Ca P HAase was identical to the HYAL1-type HAase present in human serum and ur ine. Full-length HYAL1 transcript and splice variants were detected in CaP cells by reverse transcriptase-polymerase chain reaction, cloning, and sequ encing. Immunoblotting confirmed secretion of a similar to 60-kDa HYAL1-rel ated protein by CaP cells. Immunohistochemistry showed minimal HA and HYAL1 staining in NAP and BPH tissues. However, a stromal and epithelial pattern of HA and HYAL1 expression was observed in CaP tissues. While high HA. sta ining was observed in tumor-associated stroma, HYAL1 staining in tumor cell s increased with tumor grade and metastasis. The gel-filtration column prof iles of HA species in NAP, BPH, and CaP tissues were different. While the h igher molecular mass and intermediate size HA was found in all tissues, the HA fragments were found only in CaP tissues. In particular, the high-grade CaP tissues, which showed both elevated RA and HYAL1 levels, contained ang iogenic KA fragments. The stromal-epithelial HA. and HYAL1 expression may p romote angiogenesis in CaP and may serve as prognostic markers for CaP.