Human ovarian adenocarcinoma cells synthesize vitronectin and use it to organize their adhesion

Extracellular matrix components and integrin receptors are frequently alter ed in cancer, including ovarian adenocarcinoma. Vitronectin (Vn) is a matri x protein mainly synthesized by liver cells; it is present in normal ovaria n surface epithelium and differentiated ovarian adenocarcinoma, but is freq uently undetectable in undifferentiated carcinoma (F. Carreiras et al., 199 6, Gynecol Oncol 62:260-267). Wondering about the cellular origin of Vn in ovarian carcinoma, we searched for evidence of Vn synthesis by these tumors . We demonstrated that three human ovarian adenocarcinoma cell lines were a ble to synthesize Vn, as revealed by the presence of Vn mRNA and the protei n. The Vn matrix promotes adhesion of ovarian tumor cells through Mi integr ins. Moreover, during in vitro growth, Vn is progressively organized into a particular pattern in combination with the recruitment of ay into focal co ntacts. Our results suggest that Vn synthesis may participate in ovarian ad enocarcinoma cell biology and raise the possibility that altered expression of Vn in some ovarian carcinomas could result from a defect in Vn synthesi s, (C) 1999 Academic Press.