Research papers: Breast CancerInduction of apoptosis in MCF-7 and MDA-MB-231 breast cancer cells by Oligonol is mediated by Bcl-2 family regulation and MEK/ERK signalingJo, Eun-Hyea *; Lee, Soo-Jina *; Ahn, Nam-Shika b; Park, Joon-Suka b; Hwang, Jae-Woonga; Kim, Sung-Hoonc; Aruoma, Okezie I.d; Lee, Yong-Soona b; Kang, Kyung-SunaAuthor Information aLaboratory of Stem Cell and Tumor Biology, Department of Veterinary Public Health, College of Veterinary Medicine bSchool of Agricultural Biotechnology, Seoul National University, Seoul cGraduate School of East-West Medical Science, Kyunghee University, Suwon, Korea dFaculty of Health and Social Care, London South Bank University, London, UK Correspondence to Professor Kyung-Sun Kang, Laboratory of Stem Cell and Tumor Biology, Department of Veterinary Public Health, College of Veterinary Medicine, Seoul National University, San 56-1, Sillim 9-dong, Gwanak-gu, Seoul 151-742, Korea Tel: +82 2 880 1246; fax: +82 2 876 7610; e-mail: email@example.com *Co-first author. Received 17 October 2005 Accepted 5 March 2006 European Journal of Cancer Prevention: August 2007 - Volume 16 - Issue 4 - p 342-347 doi: 10.1097/01.cej.0000236247.86360.db Buy Metrics Abstract Oligonol is a novel catechin-rich biotechnology product. The role of oligonol in modulating intracellular signaling mechanisms was investigated with the view of demonstrating its potential chemopreventive effect and the ability to inhibit cell proliferation using the estrogen-responsive MCF-7 and the estrogen-unresponsive MDA-MB-231 human breast cancer cell lines. Cell survival assay indicated that Oligonol was cytotoxic to both cells. Oligonol triggered apoptosis as revealed by the morphological features typical of nucleus staining and the accumulation of sub-G1 peak. Treatment with 25 μg/ml Oligonol resulted in an activation of caspase-7 and up-regulation of Bad on MCF-7 cells, while the Oligonol (20 μg/ml) induced up-regulation of Bcl-2 protein in a time–response manner on MDA-MB-231 cells. ERK1/2 in both cells were inactivated after Oligonol treatment in a time-dependent manner, and also inactivated upstream MEK1/2. Oligonol triggers apoptosis in MCF-7 and MDA-MB-231 cells through the modulation of pro-apoptotic Bcl-2 family proteins and MEK/ERK signaling pathway. © 2007 Lippincott Williams & Wilkins, Inc.