Comprehensive search for genes involved in thalidomide and valproic acid teratogenicity using early differentiation models of human iPS cells

Developmental toxicity testing is essential to identify substances that may harm embryonic de-velopment. This study aimed to establish a protocol for evaluating developmental toxicity using human induced pluripotent stem cells (iPSCs) by analyzing cellular activity and gene expression changes. Two ICH S5(R3) positive substances, valproic acid (VPA) and thalidomide (Thalido), were examined during early trichoderm differentiation without fetal bovine serum. RNA-seq analysis identified seven candidate genes, including TP63, associated with altered expression following exposure to VPA or Thalido. These genes were implicated in pathways related to tissue devel-opment, cell growth, and molecular interactions. While the assay effectively detected VPA and Thalido, its limitations include testing only soluble substances and focusing on early differentia-tion stages. Nevertheless, the protocol demonstrates potential for classification and evaluation of emerging modality drugs based on physical properties such as solubility, polarity, and pH. In-tegration with AI analysis may enhance its capacity to uncover genetic variations and evaluate previously uncharacterized substances. This study provides a foundation for alternative devel-opmental toxicity testing methods, with further refinements expected to improve accuracy and applicability in regulatory toxicology.