Journal
BIOCHEMICAL PHARMACOLOGY
Volume 91, Issue 3, Pages 390-399Publisher
PERGAMON-ELSEVIER SCIENCE LTD
DOI: 10.1016/j.bcp.2014.06.015
Keywords
Aryl hydrocarbon receptor (AHR); Gene expression; Breast cancer; Xenobiotics; Tumor necrosis factor
Categories
Funding
- NIH [P20RR016477, P20GM103434]
- PhRMA Foundation, Washington DC
Ask authors/readers for more resources
The aryl hydrocarbon receptor (AHR) is a ligand-activated transcription factor that upon activation by the toxicant 2,3,7,8 tetrachlorodibenzo-p-dioxin (TCDD) stimulates gene expression and toxicity. AHR is also important for normal mouse physiology and may play a role in cancer progression in the absence of environmental toxicants. The objective of this report was to identify AHR-dependent genes (ADGs) whose expression is regulated by AHR in the absence of toxicants. RNA-Seq analysis revealed that AHR regulated the expression of over 600 genes at an FDR < 10% in MCF-7 breast cancer cells upon knockdown with short interfering RNA. Pathway analysis revealed that a significant number of ADGs were components of TCDD and tumor necrosis factor (TNF) pathways. We also demonstrated that siRNA knockdown of AHR modulated TNF induction of MNSOD and cytotoxicity in MCF-7 cells. Collectively, the major new findings of this report are: (1) endogenous AHR promotes the expression of xenobiotic metabolizing enzymes even in the absence of toxicants and drugs, (2) AHR by modulating the basal expression of a large fraction of TNF target genes may prime them for TNF stimulation and (3) AHR is required for TNF induction of MNSOD and the cellular response to cytotoxicity in MCF-7 cells. This latter result provides a potentially new role for AHR in MCF-7 cancer progression as a mediator of TNF and antioxidant responses. (C) 2014 Elsevier Inc. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available