Elevated tissue expression of hyaluronic acid and hyaluronidase validates the HA-HAase urine test for bladder cancer

Purpose: We examined the expression of 2 bladder tumor markers, hyaluronic acid (HA) and hyaluronidase (HAase), in bladder tissues and correlated tiss ue staining with the inferences of the HA-HAase urine test, which detects b ladder cancer. Materials and Methods: A biotinylated HA binding protein and an antiHYAL1 a ntibody were used to localize HA and HYAL1 type HAase, respectively, in 83 bladder tissues. Immunoblot analysis was performed using an antiHYAL1 antib ody to detect HYAL1. Results: A total of 12 normal bladder tissues showed no (66%) to 1+ (34%) H A staining and 0 (83%) to 1+ (17%) HYAL1 staining. The staining intensity o f HA and HYAL1 increased in 71 bladder tumor specimens on chi-square analys is (p <0.001). Grade 1 tumors demonstrated 1+ (50%) to 2+ (50%) staining fo r HA and 1+ to 3+ staining for HYAL1 (37%, 37% and 26%, respectively). Grad es 2 and 3 tumors showed 2+ to 3+ HA.(94%) and HYAL1 (79%) staining. HA was expressed in tumor associated stroma and in tumor cells, whereas only tumo r cells expressed HYAL1. In bladder tumor tissues HYAL1 expression was conf irmed by immunoblot analysis. In 33 of the 34 patients (97%) with bladder c ancer from whom urine and tumor tissue specimens were obtained at the same time 2+ to 3+ staining of HA and/or HYAL1 in 12 and 21, respectively, const ituted a positive HA-HAase urine test (<kappa> = 0.945). Conclusions: To our knowledge this is the first report of HA localization i n bladder tissues and of HYAL1 in any normal or tumor tissue. A close corre lation of elevated HA and HYAL1 levels in tumor tissues with a positive HA- HAase urine test indicates that in patients with bladder cancer tumor assoc iated HA and HYAL1 are secreted in urine, causing the HA-HAase test to be p ositive.