THE SYNTHESIS OF DNA AND RNA IN HUMAN CARCINOMATOUS ENDOMETRIUM IN SHORT-TERM INCUBATION IN VITRO AND ITS RESPONSE TO OESTRADIOL AND PROGESTERONE

Abstract

SUMMARY Twenty-five endometrial carcinomas and three non-endometrial carcinomas were studied for the influence of various steroid hormones on the synthesis of DNA and RNA in short-term incubations in vitro. Endometrial carcinomas showed a dose-dependent sensitivity to progesterone in vitro, the response in both nucleic acids sometimes exceeding that of normal endometria. The mean reduction in DNA synthesis was to 46% and in RNA synthesis to 39% of the control values. Poorly differentiated carcinomas showed higher values of DNA synthesis than highly differentiated ones, as did carcinomas from younger women compared with those from older women. The response in vitro to progesterone was not correlated with these factors. Pregnenolone and a synthetic progestogen were less effective in vitro than progesterone. Oestradiol at a high concentration (20 μg/ml) in some cases significantly reduced the synthesis of both nucleic acids, possibly because of a specific 'toxic' action on the cells. No hormonal effects were observed in non-endometrial carcinomas.