title: Estrogen mitogenic action. I. Demonstration of estrogen-dependent MTW9/PL2 carcinogen-induced rat mammary tumor cell growth in serum-supplemented culture and technical implications.
abstract: The MTW9/PL cell line was established by our laboratory in culture from the carcinogen-induced hormone-responsive MT-W9A rat mammary tumor of a Wistar-Furth (W/Fu) rat. This tumor formed estrogen, androgen, and progesterone responsive tumors in W/Fu rats (Sirbasku, D. A., Cancer Res. 38:1154-1165; 1978). It was later used to derive the MTW9/PL2 cell population which was also estrogen-responsive in vivo (Danielpour, D., et al., In Vitro Cell. Dev. Biol. 24:42-52; 1988). In the study presented here, we describe serum-supplemented culture conditions in which the MTW9/PL2 cells demonstrate > or = 80-fold steroid hormone growth responses. All sera used were steroid hormone-depleted by charcoal-dextran treatment at 34 degrees C. The studies were done with horse serum as well as serum from other mammalian species. The growth of the MTW9/PL2 cells was biphasic in response to hormone-depleted serum. Concentrations of < or = 5% (v/v) promoted optimum growth. Above this concentration, serum was inhibitory. Concentrations > or = 40% (v/v) inhibited growth altogether. Addition of 1.0 x 10(-13)-1.0 x 10(-8) M 17beta,-estradiol (E2) reversed the inhibition completely. At 1.0 x 10(-8) M, estrone, estriol and diethylstilbestrol promoted growth as well as E2. Testosterone and dihydrotestosterone promoted growth only at > or = 10(-7) M. Progesterone was effective only at > or = 10(-6) M. Cortisol was ineffective. Labeled-hormone-binding analysis and Western immunoblotting documented that MTW9/PL2 cells had estrogen and progesterone receptors but not androgen or cortisol receptors. Estrogen treatment of MTW9/PL2 cells induced a concentration and time dependent increase in progesterone receptors. We conclude (1) the MTW9/PL2 population is the first highly steroid hormone-responsive rat mammary tumor cell line to be established in culture from a carcinogen-induced tumor, and (2) sera from a number of species including horse, rat and human contain an inhibitor which mediates estrogen sensitive MTW9/PL2 cell growth in culture.
authors.affiliation: The University of Texas-Houston Health Science Center, 77225-0036, USA.
authors.forename: J E
authors.initials: JE
authors.lastname: Moreno-Cuevas
authors.forename: D A
authors.initials: DA
authors.lastname: Sirbasku
mesh_terms: D000818:Animals; D001769:Blood; D002417:Cattle; D002455:Cell Division / Q000187:drug effects*; D003470:Culture Media; D004054:Diethylstilbestrol / Q000494:pharmacology; D004958:Estradiol / Q000378:metabolism / Q000494:pharmacology; D004964:Estriol / Q000494:pharmacology; D004965:Estrogen Antagonists / Q000494:pharmacology; D004967:Estrogens / Q000494:pharmacology*; D004970:Estrone / Q000494:pharmacology; D006736:Horses; D006801:Humans; D008325:Mammary Neoplasms, Experimental / Q000139:chemically induced / Q000473:pathology*; D011374:Progesterone / Q000494:pharmacology; D051381:Rats; D011920:Rats, Inbred WF; D011944:Receptors, Androgen / Q000032:analysis; D011960:Receptors, Estrogen / Q000032:analysis; D011980:Receptors, Progesterone / Q000032:analysis; D011987:Receptors, Steroid / Q000032:analysis; D013739:Testosterone / Q000494:pharmacology; D014316:Tritium; D014407:Tumor Cells, Cultured
chemical_list: D003470:Culture Media; D004965:Estrogen Antagonists; D004967:Estrogens; D011944:Receptors, Androgen; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone; D011987:Receptors, Steroid; D014316:Tritium; D004970:Estrone; D013739:Testosterone; D011374:Progesterone; D004958:Estradiol; D004054:Diethylstilbestrol; D004964:Estriol