CRISPR-Cas9 screening identifies ATOX1-driven cisplatin resistance mechanisms in liver cancer and evaluates targeted inhibitor efficacy.

Liver cancer treatment with cisplatin is often hindered by drug resistance. This study aimed to identify key genes associated with cisplatin resistance in liver cancer and develop targeted inhibitors. Using genome-wide CRISPR-Cas9 screening, ATOX1 was identified as a critical gene for cisplatin resistance. ATOX1 was highly expressed in liver cancer tissues and associated with poor prognosis. Knockdown of ATOX1 in liver cancer cells enhanced cisplatin sensitivity in vitro and in vivo. Molecular dynamics simulation and virtual screening identified compound 8 as a potent ATOX1 inhibitor with high affinity (Kd = 12.5 μM) and exhibited synergistic effects with cisplatin on liver cancer cell growth. Mechanistically, compound 8 inhibits the activity of ATOX1, leading to intracellular copper accumulation. The elevated copper levels subsequently promote increased DNA methylation at the NOTCH1 promoter, resulting in suppression of the NOTCH1/HES1 signaling pathway and enhancing the sensitivity of liver cancer cells to cisplatin. In conclusion, ATOX1 is crucial for cisplatin resistance in liver cancer and linked to poor prognosis. Targeting ATOX1 with compound 8 may be a novel therapeutic strategy for overcoming cisplatin resistance.