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Hormone and cytotoxic drug responsiveness of cultured human breast cancer cells resistant to specific hormones
Author(s) -
Coldham N. G.,
Patel K.,
Braunsberg H.
Publication year - 1990
Publication title -
international journal of cancer
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.475
H-Index - 234
eISSN - 1097-0215
pISSN - 0020-7136
DOI - 10.1002/ijc.2910450424
Subject(s) - cytotoxic t cell , medroxyprogesterone acetate , tamoxifen , hormone , medicine , endocrinology , medroxyprogesterone , endocrine system , cell culture , pharmacology , breast cancer , in vitro , biology , chemistry , cancer , biochemistry , genetics
Abstract Attempts have been made to develop sublines of MCF‐7 cells resistant to the growth‐inhibitory actions of medroxyprogesterone acetate (MPA), dexamethazone (DEX), antioestrogens or high‐dose oestradiol (E 2 ) by prolonged exposure to high hormone concentrations. While high degrees of resistance to MPA, DEX and E 2 were achieved, cells remained anti‐oestrogen‐sensitive after prolonged treatment with 4 μM tamoxifen (TAM) or the anti‐oestrogen LY 117018 (LY), Cells resistant to DEX were also resistant to MPA, while cells resistant to high‐dose E 2 remained sensitive to TAM. Cells resistant to MPA and E 2 appeared to be less responsive to cytotoxic drugs than wild‐type cells, while resistance to DEX was associated with increased sensitivity. The responses of tumours to cytotoxic drugs may be affected by prior endocrine therapy.