FOXO3 mutation predicting gefitinib-induced hepatotoxicity in NSCLC patients through regulation of autophagy

Hepatotoxicity is a common side effect for patients treated with gefitinib,but the related pathogenesis is unclear and lacks effective predictor and management strategies.A multi-omics approach integrating pharmacometabolomics,pharmacokinetics and pharmacogenomics was employed in non-small cell lung cancer patients to identify the effective predictor for gefitinib-induced hepatotoxicity and explore optional therapy substitution.Here,we found that patients with rs4946935 AA,located in Forkhead Box O3(FOXO3)which is a well-known autophagic regulator,had a higher risk of hepatotoxicity than those with the GA or GG variant(OR=18.020,95%CI=2.473 to 459.1784,P=0.018)in a gefitinib-concentration dependent pattern.Furthermore,functional experiments identified that rs4946935_A impaired the expression of FOXO3 by inhibiting the promotor activity,increasing the threshold of autophagy initiation and inhibiting the autophagic activity which contributed to gefitinib-induced liver injury.In contrast,erlotinib-induced liver injury was independent on the variant and expression levels of FOXO3.This study reveals that FOXO3 mutation,leading to autophagic imbalance,plays important role in gefitinib-induced hepatotoxicity,especially for patients with high concentration of gefitinib.In conclusion,FOXO3 mutation is an effective predictor and erlotinib might be an appropriately and well-tolerated treatment option for patients carrying rs4946935 AA.