Catalase Expression Is an Independent Prognostic Marker in Lung Adenocarcinoma

Abstract

Background/aim: Lung adenocarcinoma (LUAD) is the deadliest cancer, and approximately 20% of stage I LUAD cases recur after surgical resection due to its high intratumor heterogeneity. Reactive oxygen species (ROS) have been detected in LUAD and are involved in carcinogenesis and tumor progression. Here, a comprehensive analysis was performed to evaluate the effects of antioxidants on the prognosis of LUAD.

Materials and methods: The Cancer Genome Atlas (TCGA) database was used to study the relationship of gene expression of different ROS-scavenging enzymes with the progression and prognosis of LUAD.

Results: Using TCGA LUAD datasets, we found that catalase (CAT) expression was significantly down-regulated in LUAD tissues compared to normal tissues, CAT down-regulation differed significantly between different grades of LUAD, low CAT expression was independently correlated with a worse prognosis in LUAD, and the expression of the CAT gene was associated with an inhibition of the "cell cycle". A panel of LUAD cells (CL1-0, CL1-1, CL1-3, and CL1-5), which harbored mutated p53 (R248W), with gradually increasing invasiveness showed a gradual decrease in CAT expression. Silencing of CAT upregulated cell growth in A549 cells, which harbor wild-type p53 and show high CAT expression and was associated with an increase in the expression of BUB1B, PLK1, and PKMYT1. Finally, over 38% (186/490) of LUAD cases with a p53 mutation exhibited significantly lower CAT expression than those with wild-type p53.

Conclusion: CAT expression is a potent favorable prognostic marker for LUAD and may represent a drug target.

Keywords: CAT; ROS; TCGA; cell cycle; lung adenocarcinoma.