Hormone suppression of DNA synthesis in cultured chondrocyte and osteosarcoma cell line

Recent evidence suggests that endocrine factors play an important role in the natural history of osteosarcoma. The occurrence of this tumor in the metaphysis of rapidly growing adolescents, coupled with increased female survival led to the investigation of the effects of various hormones on cultured osteosarcoma cells. The in vitro effects of physiologic concentrations of human growth hormone, 17beta estradiol, and progesterone on cultured osteosarcoma cells and chondrocytes are presented. Growth hormone significantly enhances 3H-thymidine incorporation in osteosarcoma cells and chondrocytes, in the presence of human serum. The use of other sera, culture media, or heat inactivation of the human serum abolishes this effect. Estradiol and progesterone, alone, or in combination produce significant suppression of DNA synthesis in cultured tumor cells. Several sera contain a heat-labile factor which has the capacity to block the suppressive effect of estradiol. This factor could be overcome by increasing the concentration of hormone, or by heat-inactivation of the serum. The use of hormone therapy in the treatment of osteosarcoma has never been reported, despite its demonstrated value in certain other malignancies. In light of these observations and considering the poor prognosis in this disease it seems reasonable to initiate a study of adjunctive hormone therapy in osteosarcama.