Effect of ellagic acid on the expression of human telomerase reverse transcriptase (hTERT) α+β+ transcript in estrogen receptor-positive MCF-7 breast cancer cells

ObjectivesTo evaluate the potential of ellagic acid to inhibit the expression of human telomerase reverse transcriptase (hTERT) α+β+ splice variant in MCF-7 breast cancer cells.Design and methodsMCF-7 cells were incubated with ellagic acid (10− 9 M–10− 5 M) in the absence and in the presence of 17β-estradiol (10− 8 M), a known inducer of hTERT transcription, and hTERT α+β+ mRNA expression was quantified by real-time RT-PCR. 17β-estradiol and ICI182780, a known estrogen antagonist, served as positive and negative controls respectively.ResultsEllagic acid, when alone, increased hTERT α+β+ mRNA while its coexistence with 17β-estradiol reduced significantly the 17β-estradiol-induced increase in hTERT α+β+ mRNA, implicating thus both its estrogenic and anti-estrogenic effects in breast cancer cells.ConclusionsThe potential of ellagic acid to down-regulate the 17β-estradiol-induced hTERT α+β+ mRNA expression may be a mechanism via which ellagic acid exerts, at least in part, its chemopreventive effects in breast cancer.