Expression of CD44 in Epithelial Ovarian Tumors

ABSTRACT

CD44 is a hyaluronic acid receptor that exists as a standard 90-kd form (CD44H) as well as several CD44 variants isoforms are produced through alternative splicing. Alternatively spliced variants of the CD44 molecule have been found to be associated with invasive and metastatic potential of cancer cells and poor prognosis in several types of carcinoma. The purpose of the present study is to define the expression of CD44H and CD44v6 in ovarian tumors and to investigate whether the expression of these molecules is associated with adverse prognosis. We evaluated the expression of CD44 isoforms in 58 ovarian tumors by means of immunohistochemistry, and correlated between CD44 expression and the histologic types, tumor grade, peritoneal implants, pseudomyxoma peritonei and FIGO stage. While the CD44H was commonly expressed in ovarian tumors, the CD44v6 was expressed in a minor proportion of serous tumors in comparison with frequent expression of v6 isoform in mucinous tumors. The CD44H expression was significantly higher in stage I/II than in stage III. However, there was no correlation between the expression of CD44 and the presence of peritoneal implants or pseudomyxoma peritonei. These results suggest that CD44H could play an important role in the adhesive function in the lower stage of the ovarian tumor and reduced expression in the higher stage might be related to the metastasis and widespread invasion of ovarian carcinoma cells.