Disruption of cellular gene expression on TGF-β signaling by perfluorooctanoic acid (PFOA) and its novel substitute Perfluoro(2-methyl-3- oxahexanoic) acid (GenX) in vitro

Abstract

Introduction: This study explores the cytotoxic effects of Per- and polyfluoroalkyl substances (PFAS), specifically focusing on Perfluorooctanoic acid (PFOA) and its industrial substitute, Gen-X, on a set of human cancer cell lines. PFAS are synthetic chemicals with widespread use and environmental persistence, raising concerns over their potential bio accumulative properties and toxicity. Research aims to elucidate the mechanistic impact of PFOA and Gen-X exposure on cell viability, gene expression, and protein signaling pathways including TGF-β/SMAD, p53 signaling across melanoma (A375), renal (SN12C), liver (HepG2), and colon (SW620) cancer cells.Method: Employing a comprehensive experimental approach, the study assessed cytotoxicity using the CCK-8 assay, protein expression via Western blot analyses, and gene expression changes through RT-PCR. Four human cancer cell lines were exposed to varying concentrations of PFOA and Gen-X to determine their semi-inhibitory concentrations (IC50) and to analyze the subsequent biological effects.Result: The results highlighted distinct cytotoxic profiles for PFOA and Gen-X across the examined cell lines, revealing variations in cellular susceptibility and resistance. Melanoma cancer cells (A375) displayed high sensitivity to PFOA but greater tolerance to Gen-X, while renal cancer cells (SN12C) showed significant resistance to both compounds. Molecular analyses indicated that exposure to PFOA and Gen-X modulates the TGF-β/SMAD signaling pathway and activates DNA damage response markers. Furthermore, alterations in the expression of genes related to the cell cycle, apoptosis, and metabolic processes were observed, suggesting potential genotoxic and carcinogenic effects.Conclusion: The study provides insights into the differential cytotoxic effects of PFOA and Gen-X on human cancer cell lines, underscoring the complex interaction between these PFAS and cellular mechanisms. The findings indicate that PFAS exposure can significantly impact cell viability, gene expression, and protein signaling pathways, contributing to our understanding of their toxicological profile. Given the environmental persistence and widespread use of PFAS, these results underscore the need for further research into their biological impacts and the development of targeted intervention strategies to mitigate their health risks.