Integrative transcriptomics analysis reveals convergent toxicological effects of perfluorooctanoic acid and perfluorooctane sulfonate on human liver: Evidence from multiple models

Perfluorooctanoic acid and perfluorooctane sulfonate are well-known eight-carbon per- and polyfluoroalkyl substances (8C-PFAS) potentially toxic for the human liver. However, direct experimental evidence demonstrating their toxicity on the human liver remains limited. Consequently, this study aimed to extrapolate the 8C-PFAS liver toxicity mechanisms by leveraging omics data to integrate mouse and human findings. Through integration analyses of nine datasets (one human, six murine, and two rat), we identified 199 genes with known biological functions that are commonly affected by 8C-PFAS across species. We delineated a comprehensive regulatory network of 8C-PFAS toxicity, demonstrating that 8C-PFAS may trigger fatty liver disease by up-regulating CD36 and PPARα pathway; dysregulate xenobiotic metabolism by disrupting CAR and CYP family genes; and induce cancer by dysregulating WNT, TGFβ, FGF21, and P53 pathways. We also identified ATF3, EGR1, ESR1, NFATC4, SNAI2, TP53, and EZH2 as transcriptionally regulated by 8C-PFAS, along with PPARα, RXRα, FGFR1, TCF3, and SMAD3 as potentially functionally impacted. Collectively, these factors account for over 90 % of 8C-PFAS-affected key genes. This study not only developed a novel method for extrapolating human toxicity risks by integrating scattered toxicity evidence based on transcriptomics data, but also proposes new mechanisms by which 8C-PFAS contributes to fatty liver disease and cancer.