Bioinformatics analysis reveals SOD1 is a prognostic factor in lung adenocarcinoma.

Abstract

Lung cancer is a major cause of cancer-related deaths worldwide. Unfortunately, non-small cell lung cancer (NSCLC) often lacks clear clinical symptoms and molecular markers for early diagnosis, which can hinder the initiation of timely treatments. In this study, we conducted an extensive bioinformatics analysis of copper-zinc superoxide dismutase (SOD1), a molecule linked to lung adenocarcinoma (LUAD) to enhance early detection and treatment approaches for this condition. A bioinformatics analysis was conducted using a dataset from The Cancer Genome Atlas (TCGA) database. Several analytical methods, such as a differential expression analysis, a Kaplan-Meier survival analysis, a clinicopathological analysis, an enrichment analysis, protein-protein interaction (PPI) network construction using the Search Tool for the Retrieval of Interacting Genes/Proteins (STRING) database, and an immunoreactivity analysis of SOD1 expression in LUAD using TIMER were employed. We further validated the expression of SOD1 in LUAD through in vitro experiments using quantitative polymerase chain reaction (qPCR) and Western blot. Our findings indicate that LUAD tissues exhibited significantly higher expression levels of SOD1 than healthy tissues. The univariate Cox analysis showed that the elevated level was linked to unfavorable overall survival (OS) rates. Further, the Cox regression analysis of multiple variables suggested that elevated SOD1 expression levels acted as an autonomous prognosticator for unfavorable OS. We also conducted Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses, and a gene set enrichment analysis (GSEA) and observed differential pathway enrichment among patients with high SOD1 expression. In addition, a correlation between SOD1 and immune cell infiltration was found. The in vitro experiments confirmed that SOD1 expression was upregulated in LUAD. SOD1 could serve as a reliable prognostic indicator in individuals diagnosed with LUAD. Our findings may prove valuable in the development of therapeutic and prognostic markers for LUAD. The potential clinical utility of SOD1 in LUAD requires further investigation.