NNMT and the methylation sink: integrating metabolism, epigenetics and immunity in cancer.
Level 5 - mechanism / opinion, no new human data
Narrative review of biological mechanisms and preclinical literature without original human data or systematic review methodology.
PubMed 42286598 · doi:10.1186/s12916-026-04986-7
What was done
This narrative review synthesized published literature on the role of nicotinamide N-methyltransferase (NNMT) in tumorigenesis. The authors described how NNMT-mediated conversion of S-adenosyl-L-methionine (SAM) and nicotinamide (NAM) to 1-methylnicotinamide (MNAM) and S-adenosyl-homocysteine (SAH) creates a methylation sink linking metabolism to epigenetic changes across DNA, RNA, and proteins, and reviewed potential therapeutic targeting approaches.
What was found
The abstract reports no quantitative metrics or numerical data. It describes that NNMT is upregulated across multiple malignancies and stromal cell types (such as cancer-associated fibroblasts and pericytes), correlates with cancer hallmarks including tumor growth, metastasis, immune evasion, angiogenesis, stemness, and therapy resistance, and highlights emerging therapeutic strategies including competitive inhibitors and combination regimens.
Why it matters
It provides a conceptual framework linking NNMT metabolic activity to tumor epigenetics and outlines the rationale for developing NNMT-targeted biomarkers and cancer therapies.
Limits
The paper is a narrative review presenting no new empirical data, effect estimates, or systematic synthesis methods. Findings reflect mechanistic and preclinical models, and clinical efficacy or safety of NNMT inhibitors in humans is not established in the abstract.
Cited by
- supports 1-Methylnicotinamide (1-MNA) is the breakdown clearance byproduct of NAD metabolism.