The prognostic and immunological role of NADPH oxidase in early and locally advanced lung adenocarcinoma

Lung adenocarcinoma (LUAD) is the pathological type with the highest proportion and heterogeneity in lung cancer. NADPH oxidase is an important enzyme in the biological respiratory chain that plays a decisive role in cell growth, regulation, and apoptosis, which translating seven gene families, namely NOX1-5 and DUOX1-2. The current study aimed to investigate the expression, and prognostic and immune-related roles of this gene family in early and advanced LUAD. Gene expression was examined using the Oncomine™ database, prognostic value was analyzed by Kaplan-Meier analysis, expression of NOX2 and NOX4 in early and locally advanced LUAD was validated using RT-qPCR, and the correlation of infiltrating immune cells was validated by tumor immune estimation resources (TIMER). Over-expressed NOX4 was associated with lower prognosis; NOX2 was found to be under-expressed in LUAD. Both NOX2 and NOX4 expression was positively related to tumor purity and had positive correlation with infiltrating levels of immune cells in TIMER. The data reflected the potential association of NADPH oxidase in early and locally advanced lung adenocarcinoma. Our data suggested that the combination of NOX4 suppression, NOX2 depression, and immunotherapy would improve clinical outcome in these tumors.