Journal article
Mechanisms of Cancer Prevention by Green and Black Tea Polyphenols
Anti-cancer agents in medicinal chemistry, Vol.6(5), pp.389-406
09/2006
DOI: 10.2174/187152006778226468
PMID: 17017850
Abstract
Drinking green tea is associated with decreased frequency of cancer development. This review outlines the wide range of mechanisms by which epigallocatechin gallate (ECGC) and other green and black tea polyphenols inhibit cancer cell survival. EGCG suppressed androgen receptor expression and signalling via several growth factor receptors. Cell cycle arrest or apoptosis involved caspase activation and altered Bcl-2 family member expression. EGCG inhibited telomerase activity and led to telomere fragmentation. While at high concentrations polyphenols had pro-oxidative activities, at much lower levels, anti-oxidative effects occurred. Nitric oxide production was reduced by EGCG and black tea theaflavins by suppressing inducible nitric oxide synthase via blocking nuclear translocation of the transcription factor nuclear factor-κB as a result of decreased IκB kinase activity. Polyphenols up- or down-regulated activity of a number of key enzymes, including mitogen-activated protein kinases and protein kinase C, and increased or decreased protein/ mRNA levels, including that of cyclins, oncogenes, and tumor suppressor genes. Metastasis was inhibited via effects on urokinase and matrix metalloproteinases. Polyphenols reduced angiogenesis, in part by decreasing vascular endothelial growth factor production and receptor phosphorylation. Recent work demonstrated that EGCG reduced dihydrofolate reductase activity, which would affect nucleic acid and protein synthesis. It also acted as an aryl hydrocarbon receptor antagonist by directly binding the receptors molecular chaperone, heat shock protein 90. In conclusion, green and black tea polyphenols act at numerous points regulating cancer cell growth, survival, and metastasis, including effects at the DNA, RNA, and protein levels.
Details
- Title: Subtitle
- Mechanisms of Cancer Prevention by Green and Black Tea Polyphenols
- Creators
- Lisa Ann BeltzDiana Kay BayerAmber Lynn MossIra Mitchell Simet - University of Northern Iowa
- Resource Type
- Journal article
- Publication Details
- Anti-cancer agents in medicinal chemistry, Vol.6(5), pp.389-406
- DOI
- 10.2174/187152006778226468
- PMID
- 17017850
- ISSN
- 1871-5206
- eISSN
- 1875-5992
- Language
- English
- Date published
- 09/2006
- Academic Unit
- Stead Family Department of Pediatrics; Rheumatology, Allergy, and Immunology; Internal Medicine
- Record Identifier
- 9984695834002771
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