Human Embryoid Body-Based Assays for Preclinical Screening of Potential Teratogenic Drugs: Antiviral Drugs for Hepatitis B Virus as Examples

Ensuring the safety of drugs during pregnancy is a critical concern in clinical practice. Animal tests are not always reliable for accurately identifying human teratogens, as evidenced by the infamous thalidomide case. Therefore, there is an urgent need for rapid, dependable, and cost-effective human in vitro assays for potential teratogenic drugs. Here, we utilized human embryoid body (hEB)-based assays, both serum-free and supplemented with pregnant woman serum, along with RNA-sequencing analyses, to demonstrate the effectiveness of hEB transcriptomics as a powerful tool for identifying potential teratogenic drugs, in comparison with other cell systems. Additionally, we subjected our hEB systems to C_max doses of four nucleoside/nucleotide analogs (adefovir dipivoxil [ADV], entecavir [ETV], lamivudine [LAM], and tenofovir disoproxil fumarate [TDF]), which are used for anti-hepatitis B virus treatment and belong to different pregnancy-related risk categories. Transcriptomics after drug treatments were determined and analyzed for important changes in genes, gene categories, signaling pathways, and cell lineages. TDF and ADV appear to be safer options during the very early stages of embryonic development compared with LAM and ETV. Our findings indicate that EB transcriptomics-based analyses can accurately identify potent teratogens and aid in assessing the potential risk of commonly prescribed drugs during pregnancy.