Hyaluronan synthase expression in ovarian cancer

To determine if the immunohistochemical expression of hyaluronan synthase (HAS) correlates with the clinicopathological manifestations or clinical outcomes of ovarian carcinoma, sections of tumor tissue from 33 ovarian cancer patients were immunostained by the avidin-biotin-peroxidase complex method using anti-HAS1, anti-HAS2, anti-HAS3 and anti-CD44 antibody. A section was defined as having positive expression when >50% of the tumor cells were intensely stained. The microvessel density, which was defined as the mean number of new vessels, was determined under light microscopy. In the 33 ovarian cancer cases, 12 cases had positive expression of HAS1, 21 cases had positive expression of HAS2 and 11 cases had positive expression of HAS3. The expression of HAS1, HAS2 and HAS3 was unrelated to the stage of disease. CD44 expression occurred more frequently in the HAS1-positive group than in the HAS1-negative group, but the expression of HAS2 and HAS3 was unrelated to CD44 expression. The microvessel density was higher in the HAS1-positive group than in the HAS1-negative group. But the microvessel density did not differ in relation to the expression of HAS2 and HAS3. In the 23 patients that received chemotherapy, the expression of HAS1, HAS2 and HAS3 was unrelated to the chemotherapy response. The overall survival time was longer in the HAS1-negative group than in the HAS1-positive group. However, the expression of HAS2 and HAS3 was unrelated to the overall survival time. These results suggest that HAS1 expression in ovarian cancer may be associated with disease progression through angiogenesis and is an independent predictor of patient survival.