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Evidence-Based Complementary and Alternative Medicine
Volume 2012 (2012), Article ID 702857, 15 pages
http://dx.doi.org/10.1155/2012/702857
Research Article

Inhibition of Cell Growth and Induction of Apoptosis by Antrodia camphorata in HER-2/neu-Overexpressing Breast Cancer Cells through the Induction of ROS, Depletion of HER-2/neu, and Disruption of the PI3K/Akt Signaling Pathway

1Department of Health and Nutrition Biotechnology, Asia University, Taichung 41354, Taiwan
2Institute of Nutrition, China Medical University, Taichung 40402, Taiwan
3Department of Life Sciences, China Medical University, Taichung 40402, Taiwan
4Department of Cosmeceutics, College of Pharmacy, China Medical University, Taichung 40402, Taiwan
5Department of Medical Research, Chi-Mei Medical Center, Tainan 71079, Taiwan
6Institute of Biochemistry and Biotechnology, Chung Shan Medical University, Taichung 40402, Taiwan
7Department of Life Sciences, National Central University, Chung Li 32001, Taiwan

Received 16 February 2012; Accepted 2 April 2012

Academic Editor: Raffaele Capasso

Copyright © 2012 Chuan-Chen Lee et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Previously, we demonstrated that a submerged fermentation culture of Antrodia camphorata (AC) promotes cell-cycle arrest and apoptosis in human estrogen receptor-positive/negative breast cancer cells. However, whether AC is effective against HER-2/neu-overexpressing breast cancers has not been thoroughly elucidated. In the present study, we showed that AC exhibited a significant cytotoxic effect against HER-2/neu-overexpressing MDA-MB-453 and BT-474 cells. Immunoblot analysis demonstrated that HER-2/neu and their tyrosine phosphorylation were inhibited by AC in a dose-dependent manner. An increase in intracellular reactive oxygen species (ROS) was observed in AC-treated cells, whereas antioxidant N-acetylcysteine (NAC) significantly prevented AC induced HER-2/neu depletion and cell death, which directly indicates that AC-induced HER-2/neu depletion and cell death was mediated by ROS generation. Also, AC significantly downregulated the expression of cyclin D1, cyclin E, and CDK4 followed by the suppression of PI3K/Akt, and their downstream effectors GSK-3β and β-catenin. Notably, AC-treatment induced apoptotic cell death, which was associated with sub-G1 accumulation, DNA fragmentation, mitochondrial dysfunction, cytochrome c release, caspase-3/-9 activation, PARP degradation, and Bcl-2/Bax dysregulation. Assays for colony formation also confirmed the growth-inhibitory effects of AC. This is the first report confirming the anticancer activity of this potentially beneficial mushroom against human HER-2/neu-overexpressing breast cancers.