Analysis of gap junctional intercellular communication within normal human ovarian surface epithelium and ovarian adenocarcinoma

Numerous studies have correlated reductions in gap junctional intercellular communication (GJIC) and expression of gap junction proteins (connexins) with neoplastic transformation. No studies, however, have examined this correlation in human ovarian carcinomas. Here, I have studied GJIC and connexin43 expression of early passage normal human ovarian surface epithelial (HOSE) cells and human ovarian carcinoma cells. Proliferating, nontransformed HOSE cells exhibited high levels (100%) of dye-coupling whereas transformed ovarian cells demonstrated much lower (1-10%) coupling. Connexin43 expression was examined by Western and Northern blotting and by indirect immunohistochemistry using an anti-connexin43 mouse monoclonal antibody. The nontransformed HOSE cells exhibited higher levels of connexin43 mRNA, connexin43 protein, and immunoreactive gap junctions than did the neoplastic cells. These findings indicate that GJIC and connexin expression are reduced in human ovarian carcinoma cells. The correction of this defect may be a useful therapeutic approach for treating ovarian cancer.