Heparanase-2 Expression in Normal Ovarian Epithelium and in Benign and Malignant Ovarian Tumors

Abstract

Studies have highlighted the changes that take place in the environment between the cell and the extracellular matrix during the process of neoplastic expansion. Several papers have associated the expression of heparanase 1 with various malignant tumors. Heparanase 2 is probably related to loss of cell adhesion. The aim of this study was to evaluate the expression of heparanase 2 in epithelial neoplasia of the ovaries and in samples of normal ovarian tissue. Seventy-five ovary specimens were analyzed and divided into 3 groups: 23 malignant and 35 benign epithelial ovarian neoplasia and 17 without ovarian disease. We used 2 methodological techniques for evaluating the immunoexpression of heparanase 2. The first followed the qualitative criterion of positive or negative in relation to enzymatic expression, and the second involved computerized quantification of this expression, performed on the same slides. In the quantitative analysis, we found positivity indices for heparanase 2 expression of 72.2% and 87.3% in the samples of benign and malignant neoplasias, respectively. In these, the intensity of expression and the expression index were 147.2 and 121.2, respectively, for the benign neoplasia and 134.1 and 118.0 for the malignant neoplasia. Qualitatively, its expression was strong or moderate in 44.2% of the benign and 78.2% of the malignant tumors; its expression in all of the nonneoplastic samples was negative, with the exception of one that was weakly positive. Heparanase 2 is involved in neoplastic proliferation, but it was not exclusively associated with the malignant process. Furthermore, there was no difference in its expression between benign and malignant ovarian epithelial neoplasia.