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Screening Chemical Effects on Steroidogenesis in H295R Human Adrenocortical Carcinoma Cells (SOT)
Citation:
Karmaus, A., D. L. Filer, C. Toole, AND K. Lewis. Screening Chemical Effects on Steroidogenesis in H295R Human Adrenocortical Carcinoma Cells (SOT). Presented at SOT annual meeting, san Diego, CA, March 22 - 26, 2015. https://doi.org/10.23645/epacomptox.5179018
Impact/Purpose:
poster presented at SOT annual meeting in San Diego, CA on March 24, 2015.
Description:
Proper endocrine function requires steroid hormone biosynthesis and metabolism (steroidogenesis). Disruption of steroidogenesis by environmental chemicals can result in altered hormone levels causing adverse reproductive and developmental effects. This study is the first to establish a high-throughput model to evaluate a diverse library of chemicals for effects on 13 major hormones in the steriodogenic pathway. Using H295R human adrenocortical carcinoma cells in a 96-well format, steroidogenesis was induced by pre-stimulation with 10 M forskolin for 48 hr followed by chemical exposure for 48 hr. Media were removed and hormones were quantified by HPLC-MS/MS including progestagens (pregnenolone, progesterone, and their hydroxylated metabolites), glucocorticoids (corticosterone, cortisol, and their deoxy-precursors), androgens (dehydroepiandrosterone, androstenedione, and testosterone), and estrogens (estrone and estradiol). Initially, 2086 unique ToxCast chemicals were tested at a single non-cytotoxic concentration, of which 1215 chemicals (58%) altered levels of at least one measured hormone. Based on the single concentration analysis, 523 chemicals altering the levels of ≥4 hormones were selected for six-point concentration-response (0.003 – 100 M). The concentration-dependent evaluation of 13 hormones not only screened for chemical-elicited interference in the steroidogenesis pathway, but also identified a putative mechanism of action. For example, few chemicals altered only progestagen levels, while changes in testosterone and estrogen levels were more often observed. These results suggest CYP19A aromatization and CYP17A lyase and hydroxysteroid dehydrogenase activity are the likely targets for the disruption of steroidogenesis by a subset of ToxCast chemicals. This abstract does not necessarily reflect US EPA policy.
URLs/Downloads:
DOI: Screening Chemical Effects on Steroidogenesis in H295R Human Adrenocortical Carcinoma Cells (SOT)