Estrogen sulfates: biological and ultrastructural responses and metabolism in MCF-7 human breast cancer cells.
The biological effects and ultrastructural alterations by different estrogen-3-sulfates (E1-3-S and E2-3-S) and estradiol-17-sulfate (E2-17-S) were studied in the MCF-7 mammary cancer cell line in culture. The estrogen-3-sulfates very significantly stimulated the progesterone receptor (PR). The values (in pmoles/mg DNA +/- SE) were: control, 0.46 +/- 0.09; E1-3-S, 2.24 +/- 0.30, and E2-3-S, 2.56 +/- 0.45. The value of PR after E2-17-S incubation (0.56 +/- 0.24) was similar to the non-treated cells. The PR values obtained by the incubation of unconjugated estrone and estradiol were: 2.63 +/- 0.45 and 2.27 +/- 0.36, respectively. Analysis of the unconjugated estrogens in the medium indicated significant hydrolysis of estrogen-3-sulfates but not of E2-17-S. Using [3H]-E1-3-S, an important transformation was observed inside the cells, a great part being converted to estradiol (greater than 60% in the nuclear fraction). Electron microscopic examination indicated alterations in the secretory system after incubation with estrogen-3-sulfates similar to those obtained with unconjugated estradiol. The effect provoked by E2-17-S was significantly less than for the other sulfates. As estrogen sulfates are quantitatively the most important form of estrogens in the mammary gland, it is suggested that estrogen-3-sulfates play an important role in the biological responses to estrogens in breast cancer.
D001943:Breast Neoplasms / Q000378:metabolism / Q000648:ultrastructure*; D002460:Cell Line; D004305:Dose-Response Relationship, Drug; D004958:Estradiol / Q000031:analogs & derivatives / Q000378:metabolism; D004966:Estrogens, Conjugated (USP) / Q000378:metabolism*; D004970:Estrone / Q000031:analogs & derivatives / Q000378:metabolism; D005260:Female; D006801:Humans; D008854:Microscopy, Electron; D011980:Receptors, Progesterone / Q000378:metabolism; D014018:Tissue Distribution
D004966:Estrogens, Conjugated (USP); D011980:Receptors, Progesterone; C031555:estradiol sulfate; D004970:Estrone; D004958:Estradiol; C017296:estrone sulfate