COMPARISON OF DHEA METABOLISM BY MCF-7 CELLS IN CULTURE AND THEIR EXTRACTS

Dehydroepiandrosterone (DHEA) was incubated with MCF-7 in long-term culture and with subcellular fractions from these cells. Its metabolism was qualitatively and quantitatively different in the two cases. We failed to demonstrate estradiol formation from MCF-7 when incubations were carried out with cells in culture. Extracts of the human breast cancer cell line MCF-7 were able to aromatize DHEA into estradiol. 5-androstenediol and DHEA-sulfate were obtained under both incubation conditions. A high level of androstenedione was only obtained with cell extracts. These results show that the enzymes involved in the two types of incubations are different and suggest that metabolic regulation occurs in MCF-7 in culture allowing them to modify their hormonal environment.