In vivo and in vitro studies of experimental ovarian adenocarcinoma in rats.

When 7,12-dimethylbenz[a]anthracene-impregnated sutures were directly applied to the ovarian parenchyma of 8-week-old Sprague-Dawley rats (the clipping method), adenocarcinomas developed in 29 (39%) of the 75 rats during the 50-week observation period. When 20-methylcholanthrene was used, adenocarcinomas developed only in 1 (3%) of the 31 rats. Thus, the clipping method using 7,12-dimethylbenz[a]anthracene is satisfactory as an animal model of ovarian adenocarcinoma which comprises 85 to 90% of human malignant ovarian tumors. On the other hand, attempts were made to isolate cloned cell lines from these experimental ovarian adenocarcinomas in vitro, and two cloned cell lines were obtained. They were epithelioid and produced undifferentiated adenocarcinomas by back-transplantation into isologous newborn rats.