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Mol Nutr Food Res. 2015 Feb;59(2):203-11. doi: 10.1002/mnfr.201400485. Epub 2014 Nov 17.

Differential prooxidative effects of the green tea polyphenol, (-)-epigallocatechin-3-gallate, in normal and oral cancer cells are related to differences in sirtuin 3 signaling.

Author information

1
Department of Food Science, The Pennsylvania State University, University Park, PA, USA.

Abstract

SCOPE:

We have previously reported that the green tea catechin, (-)-epigallocatechin-3-gallate (EGCG), can induce oxidative stress in oral cancer cells but exerts antioxidant effects in normal cells. Here, we report that these differential prooxidative effects are associated with sirtuin 3 (SIRT3), an important mitochondrial redox modulator.

METHODS AND RESULTS:

EGCG rapidly induced mitochondria-localized reactive oxygen species in human oral squamous carcinoma cells (SCC-25, SCC-9) and premalignant leukoplakia cells (MSK-Leuk1), but not in normal human gingival fibroblast cells (HGF-1). EGCG suppressed SIRT3 mRNA and protein expression, as well as, SIRT3 activity in SCC-25 cells, whereas it increased SIRT3 activity in HGF-1 cells. EGCG selectively decreased the nuclear localization of the estrogen-related receptor α (ERRα), the transcription factor regulating SIRT3 expression, in SCC-25 cells. This indicates that EGCG may regulate SIRT3 transcription in oral cancer cells via ERRα. EGCG also differentially modulated the mRNA expressions of SIRT3-associated downstream targets including glutathione peroxidase 1 and superoxide dismutase 2 in normal and oral cancer cells.

CONCLUSION:

SIRT3 represents a novel potential target through which EGCG exerts differential prooxidant effects in cancer and normal cells. Our results provide new biomarkers to be further explored in animal studies.

KEYWORDS:

(-)-Epigallocatechin-3-gallate; Oral cancer; Prooxidant effects; Sirtuin 3; Tea

PMID:
25329972
DOI:
10.1002/mnfr.201400485
[Indexed for MEDLINE]

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