Changes in mRNA and protein levels of human HtrA1, HtrA2 and HtrA3 in ovarian cancer.

Expression of human HtrA1, HtrA2, HtrA3 and TGF-beta1 genes was examined in ovarian tissue specimens including 19 normal ovaries, 20 benign tumors, 7 borderline tumors, 44 cancers and 8 Krukenberg tumors. mRNA and protein levels were evaluated by semi-quantitative RT-PCR and Western-blotting methods, respectively. A statistically significant decrease of HtrA1 and HtrA3 expression in ovarian tumors comparing to normal tissues was observed. A dramatic decrease of HtrA3 mRNA and protein levels in all tumor tissue groups, and a loss of HtrA3 protein in 30% malignant tumors were found. A significant decrease of HtrA1 mRNA, and of HtrA3 mRNA and protein in malignant tumors compared to benign tumors was revealed. HtrA2 expression in tumor tissues was slightly decreased. Expression of TGF-beta1 in tumor tissues was not significantly different compared to control tissues. Our results show downregulation of HtrA1 and HtrA3 genes' expression in different types of ovarian tumors and give additional evidence that these genes may function as tumor suppressors.