Executive Summary : | A large body of literature bears evidences in favor of significant health benefits of green tea consumption which include cancer prevention. Epigallocatechin gallate (EGCG), a dietary polyphenol, is a major component of green tea. EGCG has been shown to affect growth of cancer cells in culture and inhibit tumor formation and progression in animal models. Given the importance of breast cancer research in India it was of our interest to understand the molecular basis of EGCG of actions in breast cancer cells with a hope that the results of such investigations would help in developing EGCG as a chemopreventive
or chemotherapeutic option. Review of literature revealed that the effect of EGCG on Estrogen mediated modulation of gene expression has not been addressed in detail. This would be of relevance since estrogen in known to play a major role on the development of breast tumors. This project seeks to understand the effect of EGCG on ER regulated gene expression in estrogen receptor (ER) positive breast cancer cells using the microarray approach. 3411 genes were regulated by estrogen, which comprised of 1689 upregulated and 1722 downregulated genes. EGCG was found to regulate a total of 3317 genes which comprised of 1844 upregulated and 1473 downregulated genes. 9183 genes were regulated by combined estrogen and EGCG treatments. A significant overlap of genes regulated by estrogen and EGCG treatment was observed. The genes regulated by estrogen and EGCG could be categorized into several functional categories. The study offers proof of concept that EGCG can affect expression of genes regulated by estrogen at the genomewide scale. The results of the work provide a much needed platform to understand the potential of EGCG as a chemotherapeutic / chemopreventive agent against breast cancer. |