The effect of sex steroids on the in vitro synthesis of DNA by malignant ovarian tumours.

The deoxyribonucleic acid (DNA) synthesis of 12 ovarian tumours was studied by means of short term organ tissue culture, exposure to tritiated thymidine and subsequent autoradiography and visual grain counting. The DNA synthesis in each tumour was studied before and after exposure to 12 separate hormone combinations. It was found that any combination of 17 beta-oestradiol with either of the two progestogens used had greater inhibitory potential than when any of three hormones tested was used alone.