Human MCF-7
breast cancer cells are relatively resistant to anti-
cancer drugs. Recently, we reported that
roscovitine (ROSC), a selective
cyclin-dependent kinase (CDK) inhibitor, arrested human MCF-7
breast cancer cells in G2 phase of the cell cycle and concomitantly induced apoptosis. Moreover, we observed that the effect of the CDK inhibitor was dependent on the content of the culture medium. The cell cycle inhibiting action of ROSC was markedly diminished in human MCF-7 cells cultivated in medium supplemented with
phenol red. These observations indicated that the
therapeutic effects of ROSC can be affected by the components of the tissue medium. Recently, a number of epidemiological and experimental studies indicated that
polyphenols (e.g.
resveratrol, epicatechins etc.), abundant
micronutrients in food, are
anti-oxidant agents and could have strong anti-mitotic as well as pro-apoptotic activities. In the present contribution we raised the question whether the ROSC-mediated cell cycle arrest could be additionally modulated by compounds of natural origin, especially by
polyphenols. Considering the potential benefits of the dietary components during the post-
chemotherapy period, we focused our attention on the effects of
resveratrol administration
after treatment with ROSC. We analyzed whether the combined treatment with
resveratrol would exert any additional effect on the cell cycle status of ROSC-treated human
cancer cells.
Resveratrol exhibited low direct cytotoxicity. The combined treatment with ROSC enhanced the ROSC-mediated inhibition of cell proliferation and cell cycle arrest. These results indicate that targeted combination of anti-
cancer drugs with distinct naturally occurring compounds could increase the efficacy of the
therapy and concomitantly reduce the undesired side effects exerted by
cytostatic drugs.