caa a22 4500 386389497 CHVBK 20180307112109.0 cr unu---uuuuu 161130s1989 xx s 000 0 eng 10.1017/S0269727000010605 doi S0269727000010605 pii (NATIONALLICENCE)cambridge-10.1017/S0269727000010605 Effects of oestrogen on human breast cancer cells in culture [Elektronische Daten] Oestrogen regulates the growth of human breast cancer cell lines ZR-75-1, T-47-D and MCF-7 (KO and McGrath). Basal cell growth can be reduced (T-47-D) or eliminated (ZR-75-1) by prior growth in the absence of steroid and phenol red for three weeks, demonstrating that oestrogens can have long-lasting effects on cells in culture (termed "steroid memory”). Effects of oestradiol on different cell biological parameters are described and interaction with other steroids and serum growth factors is discussed. Antioestrogen action in these cell lines is affected by at least five parameters: (1) presence of phenol red, (2) time in culture, (3) cell density, (4) antioestrogen concentration, (5) steroid memory. An in vitro model for loss of oestrogen sensitivity in breast cancer is presented. Both dependent (ZR-75-1) and responsive (T-47-D) cells lose oestrogen sensitivity when deprived of steroid in the long term but show a gradual increase in growth. For ZR-75-1 cells, the effects appear to be clonal but occur at a high frequency (about 1 in 1,000 cells). Parallel alterations in sensitivity to other steroids, antioestrogens and serum growth factors are shown. Molecular markers of this action are described and the results compared with the well-established model for loss of androgen/glucocorticoid sensitivity in SI 15 cells. Copyright © Royal Society of Edinburgh 1989 Mechanisms and Markers of Oestrogen Action in the Breast nationallicence Darbre Philippa D. Cellular Endocrinology Laboratory, Imperial Cancer Research Fund, Lincoln's Inn Fields, London WC2A 3PX, U.K. Daly Roger J. Cellular Endocrinology Laboratory, Imperial Cancer Research Fund, Lincoln's Inn Fields, London WC2A 3PX, U.K. Proceedings of the Royal Society of Edinburgh. Section B. Biological Sciences Royal Society of Edinburgh Scotland Foundation 95(1989), 119-132 0269-7270 95<119 1989 95 PRB https://doi.org/10.1017/S0269727000010605 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1017/S0269727000010605 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Darbre Philippa D. Cellular Endocrinology Laboratory, Imperial Cancer Research Fund, Lincoln's Inn Fields, London WC2A 3PX, U.K NATIONALLICENCE 700 1- Daly Roger J. Cellular Endocrinology Laboratory, Imperial Cancer Research Fund, Lincoln's Inn Fields, London WC2A 3PX, U.K NATIONALLICENCE 773 0- Proceedings of the Royal Society of Edinburgh. Section B. Biological Sciences Royal Society of Edinburgh Scotland Foundation 95(1989), 119-132 0269-7270 95<119 1989 95 PRB CC0 http://creativecommons.org/publicdomain/zero/1.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-cambridge