Antioxidant defense gene expression associated with lung cancer pathology: implications for diagnostic and therapeutic targets

Lung cancer is the leading cause of cancer-related mortality, and oxidative stress plays a central role in its pathogenesis. Antioxidant enzymes such as catalase (CAT) are crucial for maintaining redox homeostasis, yet their clinical application value in lung cancer treatment remains unclear. This study aimed to systematically investigate the expression, regulatory mechanism, and prognostic value of antioxidant genes, with a focus on CAT. Public databases (TCGA, HPA, UALCAN, GEPIA2, STRING, and TISIDB) were used to analyze antioxidant gene expression in various types of cancers, assess correlations with clinical pathological features, smoking status, age, and overall survival, and explore transcription factor regulation, promoter methylation, and potential therapeutic drugs. CAT expression was significantly downregulated in lung cancer patients, particularly in smokers, and positively associated with patient’s age. High CAT expression predicted better overall survival. CAT was positively regulated by EGR3, ETV1, and NFE2L2, and negatively regulated by PPAR and SP1. DrugBank analysis identified DB01213 (fomepizole) as a candidate drug targeting CAT. CAT plays a key role in lung cancer progression and may serve as a diagnostic and prognostic biomarker as well as a potential therapeutic target, providing a foundation for future antioxidant‑based strategies in lung cancer management.