Abstract
We have studied the effects of tamoxifen on the cell cycle kinetics of the endocrine-responsive MCF-7 human breast cancer cells. Tamoxifen inhibits proliferation of MCF-7 cells. The tritiated thymidine labeling index is markedly reduced by tamoxifen, indicating a reduction in the fraction of cells in S phase. Flow cytometry of mithramycin-stained cells reveals that cells accumulate in G1 phase, with a concomitant depletion of S-and G2-M-phase cells with tamoxifen. Mapping of G1-phase cells by morphology of prematurely condensed chromosomes demonstrated that tamoxifen-treated cells accumulate in early G1. These studies indicate that tamoxifen inhibits proliferation of MCF-7 human breast cancer cells by invoking a transition delay early in the G1 phase of the cell cycle.
Original language | English (US) |
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Pages (from-to) | 3583-3585 |
Number of pages | 3 |
Journal | Cancer Research |
Volume | 43 |
Issue number | 8 |
State | Published - Aug 1 1983 |
ASJC Scopus subject areas
- Oncology
- Cancer Research