PFHxS is predicted to bind KEAP1 and is associated with NRF2-NQO1 activation in hepatocellular carcinoma

Perfluorohexanesulfonic acid (PFHxS), a prevalent short-chain per- and polyfluoroalkyl substance, has been implicated in hepatocellular carcinoma (HCC), but mechanisms remain unclear. We integrated transcriptomic analyses of The Cancer Genome Atlas (TCGA) liver cancer cohort and an HCC single-cell dataset with molecular docking and molecular dynamics simulations and in vitro assays to examine a PFHxS-relevant hypothesis involving KEAP1-NRF2 signaling. Across clinical datasets, higher NQO1, an NRF2-associated gene, was linked to adverse clinicopathologic features; NQO1-high tumor cells showed elevated NRF2-activity signatures and computationally inferred increased MIF signaling toward macrophages. Because exposure information is unavailable, these observations indicate association and define a PFHxS-relevant vulnerability axis rather than PFHxS-driven tumor states. Docking/dynamics suggested PFHxS can bind the KEAP1 Kelch domain near the NRF2-binding site. In HepG2 cells, PFHxS modestly increased viability/DNA-synthesis readouts and enhanced NRF2 nuclear localization, NQO1 protein abundance, and MIF secretion; pharmacologic NRF2 inhibition partially attenuated NRF2/NQO1 readouts and reduced MIF secretion. Together, the data support the hypothesis that PFHxS may engage a KEAP1-NRF2-related vulnerability axis, accompanied by NRF2/NQO1 pathway readouts and increased MIF secretion, motivating exposure-characterized and genetic studies to establish causality.