Nicotinamide N-methyltransferase as a potential marker for cancer

Cancer remains the main global cause of death despite noteworthy advances in cancer research over the past decades. Early detection is extremely important in improving successful therapy and further work is therefore urgently required to find novel tumor markers for treatment. Herein, we studied Nicotinamide N-methyltransferase (NNMT) which is a cytosolic enzyme that catalyzes the N-methylation of nicotinamide to form 1-methylnicotinamide (1-MNA). This plays an important role in controlling the intracellular concentration of nicotinamide, the precursor to NAD+ and an important cofactor which associates cellular redox states with energy metabolism. Growing evidence shows that NNMT protein levels are elevated in a variety of human cancers, and increased NNMT expression has been linked to tumor aggressiveness. This paper presents a review of the role of NNMT expression in a series of human cancers and the regulating mechanisms involved. We offer the potential value of NNMT in cancer detection and treatment.