Epigallocatechin-3-gallate promotes apoptosis in human breast cancer T47D cells through down-regulation of PI3K/AKT and Telomerase

Background green tea has antioxidant,anti-tumor and anti-bacterial properties. epigallocatechin-3-gallate (egcg) in green tea is highly active as a cancer chemopreventive agent. in this study,we designed a series of experiments to examine the effects of egcg on proliferation and apoptosis of estrogen receptor α-positive breast cancer (t47d) cells. methods cells were treated with egcg (0–80 μm) and tamoxifen (0–20 μm),as the positive control,up to 72 h. cell viability was determined by mtt assay. apoptosis investigated by real time pcr of apoptosis and survival (bax,bcl-2,p21,p53,pten,pi3 k,akt,caspase3 and caspase9 and htert) genes and by western blot of bax/bcl-2 proteins expressions. results the results showed that egcg decreased cell viability as concentration- and time-dependently. ic50 values were 14.17 μm for t47d and 193.10 μm for hff cells,as compared with 3.39 μm and 32.75 μm for tamoxifen after 72 h treatment,respectively. also,egcg (80 μm) significantly increased the genes of pten,casp3,casp9 and decreased akt approximately equal to tamoxifen. in gene expression,egcg (80 μm) significantly increased bax/bcl-2 ratio to 8-fold vise 15-fold in tamoxifen (20 μm)–treated t47d cells during 72 h. in protein expression of bax/bcl-2,egcg significantly increased 6-fold while this ratio augmented 10-fold in tamoxifen group. egcg significantly decreased 0.8,0.4 and 0.3 gene expression of htert in 24,48 and 72 h,respectively. conclusions this study suggests that egcg may be a useful adjuvant therapeutic agent for the treatment of breast cancer. © 2017 institute of pharmacology,polish academy of sciences