Profiling the ToxCast Library With a Pluripotent Human (H9) Stem Cell Line-Based Biomarker Assay for Developmental Toxicity

Abstract

The Stemina devTOX quickPredict platform is a human pluripotent stem cell-based assay that predicts the developmental toxicity potential based on changes in cellular metabolism following chemical exposure [Palmer, J. A., Smith, A. M., Egnash, L. A., Conard, K. R., West, P. R., Burrier, R. E., Donley, E. L. R., and Kirchner, F. R. (2013). Establishment and assessment of a new human embryonic stem cell-based biomarker assay for developmental toxicity screening. Birth Defects Res. B Dev. Reprod. Toxicol. 98, 343–363]. Using this assay, we screened 1065 ToxCast phase I and II chemicals in single-concentration or concentration-response for the targeted biomarker (ratio of ornithine to cystine secreted or consumed from the media). The dataset from the Stemina (STM) assay is annotated in the ToxCast portfolio as STM. Major findings from the analysis of ToxCast_STM dataset include (1) 19% of 1065 chemicals yielded a prediction of developmental toxicity, (2) assay performance reached 79%–82% accuracy with high specificity (> 84%) but modest sensitivity (< 67%) when compared with in vivo animal models of human prenatal developmental toxicity, (3) sensitivity improved as more stringent weights of evidence requirements were applied to the animal studies, and (4) statistical analysis of the most potent chemical hits on specific biochemical targets in ToxCast revealed positive and negative associations with the STM response, providing insights into the mechanistic underpinnings of the targeted endpoint and its biological domain. The results of this study will be useful to improving our ability to predict in vivo developmental toxicants based on in vitro data and in silico models.

Beyond AOPs: A Mechanistic Evaluation of NAMs in DART Testing

“…Thus, the devTOX quick Predict™ assay covered key metabolic signatures of teratogenicity and based on this o/c ratio predicts the potential of a chemical to result in developmental toxicity ( Palmer et al, 2013 ). Additionally, biochemical profiles reflecting MIEs or signalling pathways have been correlated with both its positive and negative predictions ( Zurlinden et al, 2020 ). Zurlinden et al used a logistic regression strategy considering ToxCast assay specific AC 50 s together with a binary classification outcome model of the o/c ratio to identify sensitive and insensitive pathways associated with the assay predictions ( Zurlinden et al, 2020 ).…”

“…Additionally, biochemical profiles reflecting MIEs or signalling pathways have been correlated with both its positive and negative predictions ( Zurlinden et al, 2020 ). Zurlinden et al used a logistic regression strategy considering ToxCast assay specific AC 50 s together with a binary classification outcome model of the o/c ratio to identify sensitive and insensitive pathways associated with the assay predictions ( Zurlinden et al, 2020 ). The annotated records for these MIEs flow largely into either RTK or GPCR signalling.…”

“…Results for caffeine exposure in the devTOXquickPredict™ assays were extracted from Zurlinden et al In short, H9 cells were treated with up to 500 μM caffeine for 72 h, with media replacement every 24 h. The cell-conditioned media from the final 24 h treatment period was collected for analysis of the targeted biomarker, ornithine and cysteine ratio, and cell viability ( Zurlinden et al, 2020 ). For the ReproTracker ® , hiPSCs were differentiated into hepatocytes, cardiomyocytes and neural rosettes, respectively, in the presence of six doses of caffeine (up to 100 μM), for 21, 14 and 13 days, respectively, and any change in levels of AFP, MYH6 and Pax6 expression as well as other morphological features were monitored.…”

Industry Updates from the Field of Stem Cell Research and Regenerative Medicine in February 2020

“…Stemina has also published results from an evaluation of 1,065 chemical and drug substances using the devTOX quickPredict (devTOXqP) screening platform [7]. The data demonstrated the platform's ability to predict developmental toxicity in humans with high accuracy using a cell-based test.…”

Using Live Imaging and FUCCI Embryonic Stem Cells to Rank DevTox Risks: Adverse Growth Effects of PFOA Compared With DEP Are 26 Times Faster, 1,000 Times More Sensitive, and 13 Times Greater in Magnitude

“…With the proliferation of new drugs and commercial compounds in development and the existing drugs and compounds with insufficient DevTox data for regulatory risk assessment, NIEHS, EPA, and the National Academy of Sciences (NAS) have formulated strategies for high-throughput screens (HTS) to mediate massive in vitro testing ( Krewski et al, 2010 ; Parish et al, 2020 ) to inform or refine in vivo DevTox testing. Previous ESC tests for cytotoxicity, cardiotoxicity ( Genschow et al, 2000 ; Genschow et al, 2002 ), and metabolomic outcomes ( Zurlinden et al, 2020 ) have been validated. Many tests of pluripotent stem cells pre-differentiate these cells to other cell types, but the studies mentioned above immediately assess toxicant dose-dependent effects on stem cells cultured as stem cells.…”