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Dietary Polyphenols Show Promise in Epigenetic Regulation of Gene Expression in Breast Cancer Cells

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— 1 min read

Recent research published in Toxicology Letters suggests that dietary polyphenols may play a crucial role in the epigenetic regulation of gene expression in MCF7 breast cancer cells. The study, conducted by J. Paluszczak and colleagues at Poznan University of Medical Sciences, investigated the effect of various phytochemicals on the activity and expression of DNA methyltransferases (DNMTs) in human breast cancer cells. The findings of the study indicate that dietary phytochemicals, particularly catechol-containing polyphenols, can inhibit DNMT activity and reactivate epigenetically silenced genes.

Key Takeaways:

  • The CpG island methylator phenotype is characterized by DNA hypermethylation in the promoters of several suppressor genes associated with the inactivation of various pathways involved in tumorigenesis.
  • Dietary phytochemicals, particularly catechol-containing polyphenols, were shown to inhibit DNA methyltransferase activity with betanin being the weakest while rosmarinic and ellagic acids being the most potent modulators (up to 88% inhibition).
  • Decitabine led to a partial demethylation and reactivation of the genes, but none of the tested phytochemicals affected the methylation pattern or the expression of RASSF1A, GSTP1 or HIN1 in MCF7 cells.
  • The global methylation of histone H3 was not affected by any of the tested phytochemicals or decitabine.
  • The results suggest that non-nucleoside agents may not be effective epigenetic modulators in this experimental model.
  • However, long-term exposure to these chemicals in the diet might potentially lead to an effect sufficient for cancer chemoprevention.

Statistics:

  • Up to 88% inhibition of DNA methyltransferase activity by rosmarinic and ellagic acids.
  • DNA methylation is catalyzed by specific DNA methyltransferases (DNMTs).
  • None of the tested phytochemicals affected the methylation pattern or the expression of RASSF1A, GSTP1 or HIN1 in MCF7 cells.
  • Decitabine led to a partial demethylation and reactivation of the genes.

Sources:

  • Paluszczak, J., et al. "The effect of dietary polyphenols on the epigenetic regulation of gene expression in MCF7 breast cancer cells." Toxicology Letters, 2010; 192(2): 119-25.

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