title: Green tea catechin (-)-epicatechin gallate induces tumour suppressor protein ATF3 via EGR-1 activation.
abstract: Epicatechin gallate (ECG) is the third major catechin component in green tea, but it shows strong biological activity in some aspects, including apoptosis, cell growth inhibition, and membrane transport system in various cells. We previously reported that ECG induces activating transcription factor 3 (ATF3), which is involved in pro-apoptosis in HCT-116 cells. In this report, we present a molecular mechanism by which ECG induces ATF3 expression at the transcriptional level. We found that Sp3 contributed to the basal expression of the ATF3 gene, whereas EGR-1 played an important role in ECG-induced ATF3 expression in HCT-116 cells, as assessed by EMSA and co-transfection experiments. These results suggested that EGR-1, a tumour suppressor protein, could substantiate ECG's role of ATF3 expression in human colorectal cancer cells. We also found that pro-oxidant activity of ECG contributed to ECG-induced ATF3 expression.
authors.affiliation: Department of Pathobiology, College of Veterinary Medicine, University of Tennessee, 2407 River Drive, Knoxville, TN 37996, USA.
authors.forename: Kyou-Nam
authors.initials: KN
authors.lastname: Cho
authors.forename: Mugdha
authors.initials: M
authors.lastname: Sukhthankar
authors.forename: Seong-Ho
authors.initials: SH
authors.lastname: Lee
authors.forename: Joo-Heon
authors.initials: JH
authors.lastname: Yoon
authors.forename: Seung Joon
authors.initials: SJ
authors.lastname: Baek
mesh_terms: D051700:Activating Transcription Factor 3 / Q000378:metabolism*; D000975:Antioxidants / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D028241:Camellia sinensis; D002392:Catechin / Q000031:analogs & derivatives* / Q000494:pharmacology; D051766:Early Growth Response Protein 1 / Q000378:metabolism*; D005260:Female; D006801:Humans; D008297:Male; D013662:Tea; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism
chemical_list: D051700:Activating Transcription Factor 3; D000975:Antioxidants; D051766:Early Growth Response Protein 1; D013662:Tea; D016159:Tumor Suppressor Protein p53; D002392:Catechin; C062669:epicatechin gallate