# Transcriptomic Analysis Reveals an NRF2-Mediated Redox and Metabolic Reprogramming in Sorafenib-Resistant Hepatocellular Carcinoma Cells

## TL;DR

This study finds that resistance to sorafenib in liver cancer is linked to a change in cell metabolism and redox balance, driven by a protein called NRF2.

## Contribution

The study identifies a novel NRF2-driven metabolic and redox reprogramming mechanism in sorafenib-resistant hepatocellular carcinoma.

## Key findings

- NRF2-regulated genes like Gpx4, Txn1, and Hmox1 are upregulated in resistant cells, enhancing antioxidant defense.
- Pharmacological inhibition of NRF2 restores sorafenib sensitivity in resistant cells.
- Resistant cells show metabolic and redox reprogramming that suppresses ferroptosis and promotes survival.

## Abstract

Despite the advent of immune checkpoint inhibitor-based regimens, sorafenib remains an important therapeutic option for patients with advanced hepatocellular carcinoma (HCC) who are ineligible for immunotherapy. However, its clinical efficacy is limited by the emergence of drug resistance, whose underlying molecular mechanisms remain incompletely understood. To investigate these mechanisms, we established a murine model of acquired sorafenib resistance and performed comparative RNA sequencing of sorafenib-sensitive versus -resistant Hep55.1C hepatoma cells. Transcriptomic profiling revealed a distinct resistance-associated signature comprising 1264 significantly deregulated genes (adjusted p < 0.03, fold change > 3.0). Pathway analysis and Gene Set Enrichment Analyses (GSEA) indicated a coordinated downregulation of metabolic and intercellular signaling pathways, accompanied by marked upregulation of redox-regulatory, mitochondrial and cellular stress-response programs. Genes transcriptionally regulated by nuclear factor erythroid 2-related factor 2 (NRF2) including Gpx4, Txn1, Txnrd1, Hmox1, Fth1, Taldo1, Phgdh, and MafG, involved in antioxidant defense, ferroptosis suppression and metabolic rewiring, were all upregulated in resistant cells. Pharmacological inhibition of NRF2 activity using brusatol restored sensitivity to sorafenib, functionally implicating NRF2-dependent pathways in the maintenance of the resistant phenotype. These findings demonstrate that acquired sorafenib resistance in HCC is associated with a stable NRF2-driven transcriptional and metabolic reprogramming that enhances antioxidant capacity, suppresses ferroptosis and promotes tumor cell survival. Targeting NRF2-regulated redox metabolism may therefore represent a promising strategy to overcome therapeutic resistance in HCC.