Uncovering the Tumorigenic Blueprint of PFOS and PFOA Through Multi-Organ Transcriptomic Analysis of Biomarkers, Mechanisms, and Therapeutic Targets.

Per- and polyfluoroalkyl substances (PFASs), called forever chemicals, persist in the environment and bioaccumulate, posing significant health risks. While epidemiological studies have linked exposure to specific PFAS types, perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS), to an increased incidence of various cancers, specific tumorigenesis mechanisms are unknown. Here, we investigated the potential molecular markers and signatures of perfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) tumorigenesis. We performed a comprehensive transcriptomic analysis across multiple species and tissue types (N = 529) using PFOS and PFOA-exposed RNA-Seq samples. Conserved signatures demonstrate significant disruptions in seven key carcinogenic characteristics including metabolic reprogramming, epigenetic modifications, immune suppression, oxidative stress, and genomic instability. Tumorigenic markers such as SERPINE1, FN1, PLIN2, ALDOA, TRIB3, and TSC22D3 and their associated pathways may act independently or synergistically to promote a pro-tumorigenic environment. Additionally, PPARα, LARP1, ACOX1, MYC, and MYCN were identified as key upstream regulators supporting disruptions in lipid metabolism, oxidative stress, and uncontrolled cell proliferation. In liver samples, low concentrations of PFOS and PFOA were sufficient to exhibit tumorigenic signatures associated with tumorigenesis initiation and development. Inferred mechanisms of ccRCC initiation and development were linked to lipid metabolism dysregulation and immunosuppressive signaling. In prostate and testicular xenograft tumor models, carcinogenic mechanisms for tumor progression and promotion were hypothesized. Receptor-mediated signaling and protein synthesis was disrupted in prostate cancer and epigenetic alterations and ECM remodeling observed in testicular cancer. We also explored potential therapeutic rescue strategies, including chemopreventive agents for early intervention. All our findings provide hypotheses for PFOS/PFOA-induced tumorigenesis; however, experimental studies are required to establish translational relevance. All the R codes developed in this study are publicly available.