Epigallocatechin gallate induces the steady state mRNA levels of pS2 and PR genes in MCF-7 breast cancer cells.

Investigations using in vitro and in vivo models of breast carcinogenesis have demonstrated anti-neoplastic activity of the green tea polyphenol, epigallocatechin gallate (EGCG). Although a number of molecular targets of EGCG have been identified, its impact on the expression of estrogen target genes is not completely understood. Here, we examined the mRNA expression levels of two estrogen target genes, namely Trefoil Factor 1 (pS2) and Progesterone Receptor (PR) in MCF-7 cells treated with EGCG. We observed that treatment with 40 microM EGCG, which caused only 20% decrease in cell viability, resulted in increased steady state expression levels of pS2 and PR mRNA. This suggests that EGCG may exert its biological activities, at least in part, by influencing the expression of estrogen target genes.