The mRNA MOXD1: Link to oxidative stress and prognostic significance in gastric cancer.

PURPOSE: Oxidative stress (OS) plays a key role in gastric cancer (GC). The purpose of this study was to investigate the role of the mRNA monooxygenase DBH-like 1 (MOXD1) in OS and evaluate its prognostic significance in GC. METHODS: An OS risk score was constructed by unsupervised clustering analysis, the log-rank test, and least absolute shrinkage and selection operator-Cox analysis of OS-related genes. The Pearson correlation between MOXD1 expression and the OS risk score was evaluated. Correlations between MOXD1 expression and clinicopathological features in the training cohort were compared. CIBERSORT, ssGSEA, and ESTIMATE were used to analyze the effects of MOXD1 on the immune microenvironment. Gene Ontology, Kyoto Encyclopedia of Genes and Genomes, and gene set enrichment analysis were used to elucidate the biological functions of the mRNAs. Immunohistochemistry for MOXD1 was performed on patient tissue microarray (TMA) samples. Cox regression, log-rank tests, and chi-square analyses were used to investigate the clinicopathological features of the TMAs and associated MOXD1 expression levels. A stable knockdown cell line was constructed in HGC-27 GC cells and investigated using cell counting kit-8 and Transwell assays. RESULTS: The OS risk score was an independent prognostic factor for GC in the training cohort and was successfully combined with age and pTNM stage to construct a nomogram. MOXD1 expression was positively correlated with the OS risk score and was highly expressed in patients with GC. MOXD1 expression and the metastatic lymph node ratio in TMAs were found to be independent prognostic risk factors for GC. MOXD1 knockdown inhibited the proliferation and invasion of HGC-27 cells. CONCLUSION: The mRNA MOXD1 is a biomarker for both OS and GC. MOXD1 expression can be used to evaluate GC prognosis and guide treatment.