Abstract
The effect of 4-hydroxytamoxifen (4OH-TAM), the potent anti-estrogenic metabolite of tamoxifen, on the radiosensitivity of MCF-7 cells irradiated in vitro was determined. Radiation dose response curves were generated for MCF-7 cells maintained and irradiated in phenol red-free medium containing 10-10 M estradiol (E2) with or without 10-7 M 4OH-TAM. Immediately after irradiation cells were transferred to medium containing 10-10 M E2 supplemented with bovine serum to stimulate colony formation. Estradiol-stimulated cell proliferation was inhibited by 10-7 M 4OH-TAM, but radiation sensitivity was not significantly altered (p > 0.3). Continued incubation in the absence of E2 for an additional 24 hours after irradiation likewise failed to alter the radiosensitivity of 4OH-TAM-treated MCF-7 cells. These studies indicate that growth-inhibitory concentrations of the anti-estrogen 4OH-TAM do not modify the in vitro radiation sensitivity of this line of human breast carcinoma cells.
Original language | English (US) |
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Pages (from-to) | 159-165 |
Number of pages | 7 |
Journal | Breast Cancer Research and Treatment |
Volume | 30 |
Issue number | 2 |
DOIs | |
State | Published - Jan 1994 |
Keywords
- 4-hydroxytamoxifen
- MCF-7 cells
- growth inhibition
- radiation sensitivity
- tamoxifen
ASJC Scopus subject areas
- Oncology
- Cancer Research