Melatonin inhibits DNA synthesis in MCF-7 human breast cancer cells in vitro

Published on Tuesday, 04 April 2017


The aim of the present work was to study whether physiological doses of melatonin (1nM) modified DNA synthesis in MCF-7 human breast cancer cells.

Exponentially growing MCF-7 cells were incubated for 24 h with thymidine (2mM) for blocking mitosis and synchronizing the cell division cycle.

Synchronization was assessed by a flow cytometry study which showed that after release from excess thymidine, 82.3% of the cells were in phase G1.

Lots of these synchronized cells were pulsed for 1h with [3H]deoxythymidine ([3H]dThy) or [3H]dThy + melatonin, at 0,3,6,9,12,15 or 24 h from the release of the mitotic arrest.

The exposition of these synchronized MCF-7 cells to melatonin for only 1h, significantly inhibited [3H]dThy incorporation when it was at 6 or 9 h. after release from mitotic block, at a time when DNA precursor incorporation was the highest and the number of cells in S phase was maximum.

We conclude that, at least in part, melatonin antiproliferative effects on MCF-7 cells could be mediated by a reduction of DNA synthesis.



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See also:

- About Melatonin;

- Evaluation of the safety and efficacy of the first-line treatment with somatostatin combined with melatonisn, retinoids, vitamin D3, and low doses of cyclophosphamide in 20 cases of breast cancer: a preliminary report;

- The Di Bella Method (DBM) improved survival, objective response and performance status in a retrospective observational clinical study on 122 cases of breast cancer;

- Complete objective response to biological therapy of plurifocal breast carcinoma.