Abstract
Hyaluronic acid (HA), a glycosaminoglycan, regulates cell adhesion and migration. Hyaluronidase (HAase), an endoglycosidase, degrades HA into small angiogenic fragments. Using an enzyme-linked immunosorbent assay-like assay, we found increased HA levels (3-8-fold) in prostate cancer (CaP) tissues when compared with normal (NAP) and benign (BPH) tissues. The majority ( approximately 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 than respective NAP and BPH cultures. Only CaP epithelial cells and established 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 CaP HAase was identical to the HYAL1-type HAase present in human serum and urine. Full-length HYAL1 transcript and splice variants were detected in CaP cells by reverse transcriptase-polymerase chain reaction, cloning, and sequencing. Immunoblotting confirmed secretion of a approximately 60-kDa HYAL1-related 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 staining was observed in tumor-associated stroma, HYAL1 staining in tumor cells increased with tumor grade and metastasis. The gel-filtration column profiles of HA species in NAP, BPH, and CaP tissues were different. While the higher 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 HA and HYAL1 levels, contained angiogenic HA fragments. The stromal-epithelial HA and HYAL1 expression may promote angiogenesis in CaP and may serve as prognostic markers for CaP.
Highlights
Hyaluronic acid (HA), a glycosaminoglycan, regulates cell adhesion and migration
The differences observed in HA levels among Hepes extracts prepared from low-grade and high-grade CaP and seminal vesicles invaded with CaP tissues are not statistically significant (p Ͼ 0.05)
These results demonstrate that the levels of free HA are elevated in CaP tissues and the increase is not associated with Gleason sum and metastasis
Summary
CaP, prostate cancer; HA, hyaluronic acid; HAase, hyaluronidase; DAB, 3,3Ј-diaminobenzidine; CM, conditioned medium; SF-CM, serum-free conditioned medium; S-CM, serum tients have clinically organ-confined disease. We have previously isolated such angiogenic HA fragments from the urine of high-grade bladder cancer patients and shown that these fragments induce endothelial cell proliferation [14]. In establishing the association of HAase to tumor biology, we initially showed that HAase levels are elevated in CaP and these levels correlate with CaP progression (i.e. metastatic Ͼ high-grade ϾϾ low-grade Ͼ benign prostatic hyperplasia (BPH)/normal) [33]. We observed the expression of HYAL1 at the transcript and protein levels, in invasive bladder cancer cell lines, which secrete high levels of a HAase in their conditioned media. This HAase activity has a pH optimum in the range 4.1– 4.3 [43]. We attempted to understand the function of the tumor-associated HA-HYAL1 system
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
