FIG. 3.

Mechanism of EGCG-induced apoptosis in cancer cells through epigenetic regulation of telomerase. According to Berletch et al. (11) and Meeran et al. (52), EGCG inhibits both deoxyribonucleic acid (DNA) methyltransferase (DNMT) and histone acetyltransferase (HAT), leading to the DNA demethylation and histones H3 and H4 deacetylation of the human telomerase– reverse transcriptase (hTERT) promoter, respectively. These events result in the epigenome regulation and chromatin restructuring involving hTERT messenger ribonucleic acid (mRNA) downregulation and inhibition of telomerase and ultimately cancer cell death (apoptosis). However, these studies have not provided any links between the antioxidant actions of EGCG and its epigenetic regulation of apoptosis of the cancer cells.