Hyaluronidase gene profiling and role of hyal-1 overexpression in an orthotopic model of prostate cancer.

The mRNA levels of hyal-1, hyal-2, LUCA3 and PH20, the 4 hyaluronidases with demonstrated endoglucosaminidase activity, were extensively profiled in normal and tumor tissues and cell lines, using dot blot analysis and quantitative PCR. In normal tissues, hyal-1, hyal-2 and LUCA3 all showed unique patterns of mRNA expression, but were generally of widespread distribution, whereas PH20 mRNA was restricted to testes. In a small set of breast tumor samples, no elevations in hyal-1, hyal-2 or LUCA3 mRNA were seen. Hyaluronidase activity measured by a novel assay or zymography was also not elevated in sera from a number of breast cancer patients, compared to sera from normal volunteers. In ex vivo xenograft tumor cell lines, however, hyal-1 or hyal-2 mRNA levels were frequently elevated, whereas LUCA3 was only infrequently elevated and PH20 not at all. Two cell lines were engineered to overexpress hyal-1: a breast cancer line (CAL51) and a prostate cancer line (PC3M). Although the in vitro properties of the hyal-1 overexpressing cell lines were indistinguishable from the parental cells, the orthotopic growth of hyal-1 expressing PC3M cells in nu/nu mice resulted in significantly increased numbers of metastases, supportive of a role for hyal-1 in extravasation and metastatic tumor formation in this model of prostate cancer.