TISSUE CULTURE STUDIES ON THE HORMONE DEPENDENCE OF EXPERIMENTAL OVARIAN TUMOURS IN RATS
ABSTRACT Changes in experimental rat ovarian tumour response to steroids, tested in tissue culture, have been studied following subcutaneous isografting of such a tumour into animals in various endocrine conditions, and with the aid of repeated biopsies from such tumours left in situ intrasplenically in heterozygotic animals. The in vivo response of isografted tumours indicated a stimulation by oestrogens and progesterone. The primary tumour used for isografting experiments showed little response to steroids in vitro; the only effect obtained was a statistically non-significant arrest with oestrone (3-hydroxy-oestra-1,3,5(10)-trien-17-one). After 6 months' growth as subcutaneous grafts into hosts in various endocrine conditions, considerable changes could be demonstrated in cell response to steroids. Transplants grown in different milieus showed different responses to steroids in vitro. In some cases, stimulating effects and, in others, inhibitory ones were observed. There was also a difference in growth activity in control cultures prepared from the various transplants. Repeated biopsies made from tumours left in situ intrasplenically showed changes in response to androsterone (3α-hydroxy-5α-androstan-17-one) in vitro during the life-span of the tumour. In some cases, a loss of reactivity could be found; in other cases, a capacity to respond developed.