A team of researchers from the University of Wisconsin, Madison, Wis., and Case Western Reserve University, Cleveland, Ohio, documented the role of green tea polyphenols (GTP) in modulating the insulin-like growth factor-1 (IGF-1)-driven molecular pathway in prostate tumor cells in a mouse model for human prostate cancer.
"Consumption of GTP led to reduced levels of IGF-1," said Hasan Mukhtar, Ph.D., Department of Dermatology at the University of Wisconsin, the senior author of the paper.
"GTP also led to increased levels of one of the binding proteins for IGF-1, the insulin growth factor binding protein-3. These observations bear significance in light of studies that indicate increased levels of IGF-1 are associated with increased risk of several cancers, such as prostate, breast, lung and colon."
GTP modulation of cell growth via the IGF-1 axis coincides with limited production or phosphorylation of key cell survival proteins, including PI3K, Akt and Erk1/2, the research indicated. The PI3K molecular pathway in cells, which includes Akt and Erk1/2, works to promote cell survival, rather than programmed cell death, also known as apoptosis.
GTP also caused reduced expression of proteins known to be associated with the metastatic spread of cancer cells. GTP inhibited the levels of urokinase plasminogen activator as well as matrix metalloproteinases 2 and 9, cellular molecules linked to the metastasis.
The green tea polyphenols contributed to minimizing tumor development by governing the amount of vascular endothelial growth factor (VEGF) in the serum of the prostate cancer
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Contact: Russell Vanderboom
vanderboom@aacr.org
215-440-9300
American Association for Cancer Research
1-Dec-2004