ADH2 Is Downregulated by Methylation and Acts as a Novel Biomarker for Breast Carcinoma Prognosis

Breast carcinoma (BC) ranks the second leading cause of cancer death in females. Alcohol is consistent risk factor for BC. The alcohol dehydrogenases (ADHs) family is associated with alcohol metabolism in vivo. However, whether ADHs can act as biomarkers for BC and the underlying mechanism of them affecting BC are unclear. In the present study, the expression levels, prognostic values, epigenetic and genetic alterations, and regulatory networks of ADHs were explored in BC using public online database. Among ADHs family, the expression level of ADH2 is remarkably decreased in the BC and high expression level of ADH2 is significantly associated with better overall survival in BC. Decreasing mRNA expression level of ADH2 is due to DNA hypermethylation in the promoter rather than genetic alterations. ADH2 strongly correlates with pathways in glycolysis/gluconeogenesis, fatty acid metabolism, and cytochrome P450 pathways in BC. Our finding provided novel insights into ADH2 in BC and implied that ADH2 could act as a novel biomarker for BC prognosis.