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Journal of Toxicology
Volume 2016, Article ID 8253726, 8 pages
Research Article

Evaluating the Effects of Tetrachloro-1,4-benzoquinone, an Active Metabolite of Pentachlorophenol, on the Growth of Human Breast Cancer Cells

Drug Discovery and Development Research Group, College of Pharmacy and Nutrition, University of Saskatchewan, 107 Wiggins Road, Saskatoon, SK, Canada S7N 5E5

Received 16 September 2015; Revised 15 January 2016; Accepted 19 January 2016

Academic Editor: Brad Upham

Copyright © 2016 Binbing Ling 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.


Tetrachloro-1,4-benzoquinone (TCBQ), an active metabolite of pentachlorophenol (PCP), is genotoxic and potentially carcinogenic. As an electrophilic and oxidative molecule, TCBQ can conjugate with deoxyguanosine in DNA molecules and/or impose oxidative stress in cells. In the current study, we investigated the effects of TCBQ on intracellular ROS production, apoptosis, and cytotoxicity against three different subtypes of human breast cancer cells. Luminal A subtype MCF7 (ER+, PR+, HER2) cells maintained the highest intracellular ROS level and were subjected to TCBQ-induced ROS reduction, apoptosis, and cytotoxicity. HER2 subtype Sk-Br-3 (ER, PR, HER2+) cells possessed the lowest intracellular ROS level. TCBQ promoted ROS production, inhibited apoptosis, and elevated cytotoxicity (due to necrosis) against Sk-Br-3 cells. Triple-negative/basal-like subtype MDA-MB-231 cells were less sensitive towards TCBQ treatment. Therefore, the effect of prolonged exposure to PCP and its active metabolites on cancer growth is highly cancer-cell-type specific.