Discriminating classes of developmental toxicants using gene expression profiling in the embryonic stem cell test

Area of Science:

• Developmental toxicology
• In vitro testing
• Transcriptomics

Background:

• The embryonic stem cell test (EST) is a promising in vitro method for predicting developmental toxicity.
• Gene expression analysis can enhance the EST's ability to identify developmental toxicants.

Purpose of the Study:

• To investigate if gene expression profiling can discriminate between chemical classes with distinct modes of action (MoA) within the EST protocol.
• To identify class-specific gene signatures for improved compound prioritization.

Main Methods:

• Analysis of gene expression data from embryonic stem cell (ESC) differentiation cultures exposed to phthalates and triazoles.
• Utilized principal component analysis (PCA) for individual gene level analysis.
• Employed hierarchical clustering for functional level analysis of gene ontology (GO) biological processes.
• Applied previously identified gene sets for developmental toxicity prediction.

Main Results:

• Identified class-specific gene signatures that successfully discriminated between phthalates and triazoles using PCA.
• Enriched GO biological processes demonstrated usefulness for class discrimination via hierarchical clustering.
• Two established gene sets effectively separated phthalate from triazole compounds.

Conclusions:

• Established the feasibility of discriminating between chemical compound classes in the EST system using three transcriptomics-based approaches.
• Differential gene expression information can optimize the prioritization of compounds within specific classes for further toxicological assessment.