Steroid receptor analyses of nine human breast cancer cell lines.

Nine human breast cancer cell lines in permanent tissue culture and currently available to researchers have been assayed for their content of cytoplasmic estrogen receptors, progesterone receptors, androgen receptors, and glucocorticoid receptors, as well as for the presence of unfilled or hormone-filled nuclear estrogen receptors. Receptor distribution varied considerably among the nine lines and differed from the expected distribution predicted from solid tumors. We find that estrogen receptor, when present, is usually localized in the nucleus as unfilled nuclear estrogen receptor. Progesterone receptor is correlated with presence of unfilled nuclear estrogen receptor. Glucocorticoid receptors are ubiquitous; they were found in all cell lines tested. The distribution of androgen receptor and progesterone receptor differed, suggesting that these proteins are dissimilar.