Discipline: Biological Sciences
Subcategory: Physiology and Health
Nirisha Commodore - University of the Virgin Islands
Co-Author(s): Alejandra Ramirez-Cardenas and David Sherr, Boston University School of Public Health, Boston University School of Medicine
There are 85,000 anthropogenic chemicals registered by the Environmental Protection Agency, of which relatively few have been evaluated for their effects on human health. The Aryl Hydrocarbon Receptor (AHR) is a ligand-activated transcription factor that is notorious for its role in mediating the effects of environmental pollutants in several physiological and pathophysiological processes, for example, cancer. Many pollutants have been identified as AHR agonists. However, few antagonists have been identified. Therefore, a library of compounds was screened in silico to identify new compounds that displayed similar binding to the AHR as the known AHR antagonist, 2-((2-(5-bromofuran-2-yl)-4-oxo-4H-chromen-3-yl) oxy) acetamide (CB7993113). Five compounds, denoted as NEU1-5, were recognized as potential antagonists based on their similarity to CB7993113 and their predicted ability to bind the AHR. To test the functional characteristics of these compounds, AHR-driven reporter assays using a murine hepatoma cell line (H1G1) and an immortalized human epithelial breast cell line (MCF10F) were employed to assess the NEU compounds’ ability to inhibit AHR activation. Titrations of a non-toxic AHR agonist, beta-naphthoflavone (BNF), were performed to determine a concentration at which the activation of the AHR would be optimal for detecting any inhibition caused by the NEU compounds. Toxicity of compounds was determined by quantification of cell metabolic activity at various time points following cell treatments (MTT assay). Of the five compounds tested for AHR inhibition, NEU4 showed the most promising results. At concentrations of 10 and 50 uM, NEU4 significantly inhibited the BNF-induced AHR reporter activity by forty percent – (p-values, 0.00231, 0.00435 respectively). Toxicity quantification confirmed that there was no significant change in percent viability of cells following treatments. These experiments suggest that NEU4 may be a potent antagonist of the AHR and may represent a novel targeted cancer therapeutic.
Funder Acknowledgement(s): This project was funded by the University of the Virgin Islands, National Institute of General Medical Sciences Research Initiative for Scientific Enhancement Program (5R25GM061325) and the Boston University Summer Training as a Research Scholars Program (STaRS).
Faculty Advisor: David Sherr, email@example.com
Role: I conducted the two high-throughput bioassays using mice and human cell lines to quantify the antagonistic activity of five newly postulated inhibitors of the Aryl Hydrocarbon Receptor. Following these screenings, I performed a colorimetric assay to quantify the toxicity of these new compounds in vitro based on cell metabolic activity following treatments.