Although a significant role has been established for estrogen in the growth of some animal and human mammary carcinoma, evidence for androgen dependency of human breast cancer has remained equivocal. Although the existence of a mouse mammary carcinoma which shows modest androgen responsiveness has supported the notion that some human breast cancer might also be dependent on androgens, no direct proof has been available. The authors have described the work characterizing the estrogen responsiveness of MCF 7, a human breast cancer cell line maintained in tissue culture for over 3 yr. This cell line was shown to contain estrogen receptor, to be killed by antiestrogens, and stimulated by physiological concentrations of estradiol. The authors described further investigations of this cell line which reveal than in addition to estrogen responsiveness, this cell line shows threefold enhancement of precursor incorporation into macromolecules by androgens using serum free conditions which preclude stimulatory effects of other trophic hormones. Furthermore, this stimulation by androgens seems to be mediated by interaction with a cytoplasmic androgen receptor protein which is clearly differentiable from the estrogen receptor also found in these cells. Aside from defining an interesting new system in which the action of androgen can be studied in a human cell line in tissue culture, the present study provides unequivocal evidence for the androgen responsiveness of some human breast cancer at least in vitro.
ASJC Scopus subject areas