Evaluation of the Effect of Perfluorohexane Sulfonate on the Proliferation of Human Hepatocellular Carcinoma Cells

Perfluorohexane sulfonate (PFHxS) is a widely detected replacement for legacy long-chain perfluoroalkyl substances (PFAS) in the environment and human blood samples. Its potential toxicity led to its recent classification as a global regulated persistent organic pollutant. Although animal studies have shown a positive association between PFHxS levels and hepatic steatosis and hepatocellular hypertrophy, the link with liver toxicity, including end-stage liver cancer, remains inconclusive. In this study, we examined the effects of PFHxS on the proliferation of human hepatocellular carcinoma (HCC) cells, Hep3B and SK-Hep1. Cells were exposed to different PFHxS concentrations for 24–48 hr to assess viability and 12–14 days to measure colony formation. Viability of both cell lines increased at PFHxS concentrations 400 μM, and were highest at 50 μM. Colony formation increased at <300 μM and decreased at 500 μM PFHxS. Consistent with the effect on HCC proliferation, PFHxS increased expression of proliferating cell nuclear antigen (PCNA) and cell-cycle molecules (CDK2, CDK4, cyclin E, and cyclin D1). In summary, PFHxS exhibited a biphasic effect on HCC cell proliferation, promoting survival and proliferation at lower concentrations and being cytotoxic at higher concentrations. This suggests that PFHxS potentially exacerbates HCC progression.