RESPONSE OF 4 HUMAN OVARIAN-CARCINOMA CELL-LINES TO ALL-TRANS-RETINOIC ACID - RELATIONSHIP WITH INDUCTION OF DIFFERENTIATION AND RETINOIC ACID RECEPTOR EXPRESSION

The response of 4 human ovarian carcinoma cell lines to retinoic acid was found to be related to the histological type and degree of differe ntiation of these tumor cells. The 2 serous cell lines NIHOVCAR(3) and OVCCR(1) were the most sensitive to the antiproliferative effect of R A. This inhibition was associated with morphological and biological ch anges that were indicative of differentiation. The undifferentiated IG ROV(1) cell line was not affected by RA. Since the effects of RA are t hought to be mediated by nuclear retinoic acid receptors (RARs), the e xpression of RARs in human ovarian cancer cells was studied. RAR alpha was detected as mRNA species of 3.1 and 2.6 kb in all 4 cell lines. R AR beta was not detected in any of the cell lines, while RAR gamma (3 kb) was expressed in all of the ovarian cancer cells but at a very low level in the RA-resistant IGROV(1) cells. (C) 1994 Wiley-Liss, Inc.