Expression of NOX Family Genes and Their Clinical Significance in Colorectal Cancer.

BACKGROUND: The NADPH oxidase (NOX) family is overexpressed in many cancers and is associated with cancer cell proliferation and metastasis; however, little is known about the role of the NOX family in colorectal cancer (CRC).

AIMS: To identify the expression of the NOX family in CRC and to investigate the relationship between the expression of NOXs with the prognosis of the patients.

METHODS: In the TCGA data portal, mRNA expression data were obtained from 41 normal samples and 458 CRC samples to analyze mRNA expression and gene alteration. We compared the survival differences according to the degree of expression of NOX family in CRC patients and performed Gene Set Enrichment Analysis (GSEA).

RESULTS: The mRNA expression of NOX1, 3, 4, and DUOX1, 2 was significantly increased in the colorectal adenocarcinoma. Especially, the higher T and N stage, the more NOX4 expression was significantly increased. Survival analyses showed that NOX4 and NOX5 were associated with poor prognosis; however, NOX1 and DUOX2 were significantly associated with better prognosis. In the results of GSEA of CRC patients, the NOX4 gene was significantly associated with Angiogenesis, EMT and notch signaling.

CONCLUSIONS: The NOX family is overexpressed in CRC and is associated with the prognosis of the patient. Therefore, NOX family can predict CRC patient survival and the role of the NOX family as a molecular target in the treatment of CRC.