Diethylstilbestrol and progesterone regulation of cultured rabbit endometrial cell growth.

Abstract

Summary A new tissue culture system has been developed for the study of the effects of sexual hormones in endometrium. Rabbit uterine horns were everted, and the ends were ligated and then incubated at 37° in a buffered solution of several enzymes. With sequential incubations and extractions it was possible to obtain only the endometrial cells, which were then plated in a chemically defined medium. Two cell populations can be easily observed after attachment, epithelial cells and fibroblasts. Growth was determined by total protein measurements and autoradiography using thymidine- 3 H. The chemically defined medium sustained growth for 4 to 5 days. Then cell division stopped and, after 7 to 8 days, an accelerated decrease in the number of viable cells occurred. The addition of 10 -7 m diethylstilbestrol increased the initial growth rate and prevented the later decrease in growth rate of the epithelial cells that occurred in the absence of this hormone. The addition of 10 -7 m progesterone inhibited the growth of the epithelial-like and fibroblastic cells but induced the appearance of big, clear, multinucleated cells, derived apparently from the normal epithelial cells. Diethylstilbestrol and progesterone have antagonistic effects upon the cells, which are concentration dependent. Maintenance of the cultures in chemically defined medium plus diethylstilbestrol and progesterone for 2 weeks, with subsequent change to medium plus serum, effected a selection of pure cultures of epithelial cells. The possible therapeutical implications of these hormonal effects for endometrial carcinoma are discussed.