N-acetylcysteine-induced transcriptomic reprogramming regulates Nrf2-mediated signaling and redox homeostasis in experimental hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is the most common primary liver cancer, marked by dysregulated cellular processes and limited treatment options, highlighting the need for preventive therapeutic strategies. N-acetylcysteine (NAC), widely used to treat acetaminophen overdose and as a mucolytic agent, has not been mechanistically characterized in HCC. Here, we evaluated the effects of NAC in experimental HCC models, including its role in modulating the Nrf2/Keap1 signaling pathway. HCC was induced in male Fischer-344 rats using diethylnitrosamine (DEN) and 2-acetylaminofluorene (2-AAF), along with daily NAC administration for 16 weeks. In parallel, HepG2 cells were used to evaluate the cytoprotective effects of NAC in vitro. Biochemical, molecular, transcriptomic, histological, and immunostaining analyses were performed in serum, liver tissue, and cell samples. Our findings demonstrate that NAC exerted hepatoprotective effects that limit protumorigenic progression, fibrosis, and tumor cell proliferation. Notably, NAC regulates the Nrf2/Keap1 pathway enhancing antioxidant defenses and preserving biomolecular integrity. Transcriptomic analyses revealed that NAC partially restored disease-associated gene expression patterns by downregulating oncogenic pathways and genes involved in HCC development. In conclusion, these findings indicate that NAC modulates key cellular processes involved in HCC development and regulates disease-associated gene expression patterns, supporting its repositioning as a potential adjuvant therapeutic strategy.