{"entity":{"id":"maoa","kind":"target","name":"MAO-A (MAOA)","aka":["MAO-A","monoamine oxidase A"],"tldr":"MAO-A is an enzyme best known for breaking down serotonin and other signalling chemicals in the brain; medicines called MAO inhibitors, used for some neurological disorders, block it. Aggressive prostate cancers carry more of it, and a MAO-A inhibitor designed to stay out of the brain is in an early prostate cancer trial.","summary":"MAOA (chromosome Xp11.3) is a mitochondrial enzyme that breaks down amine neurotransmitters such as serotonin, producing hydrogen peroxide (UniProt P21397). A 2014 Journal of Clinical Investigation study reported that high-grade, aggressive prostate tumours express more MAOA, that MAOA drove epithelial-to-mesenchymal transition and stabilised HIF1-alpha through reactive oxygen species, and that knocking it down reduced or eliminated prostate tumour growth and metastasis in mouse models (Wu et al., doi:10.1172/JCI70982). In OnCo, ITR-251 is a reversible MAO-A inhibitor with limited ability to cross the blood-brain barrier, in a phase 1 trial in metastatic castration-resistant prostate cancer.","asOf":"2026-11-03","links":[{"label":"HGNC HGNC:6833","url":"https://www.genenames.org/data/gene-symbol-report/#!/hgnc_id/HGNC:6833"},{"label":"UniProt P21397","url":"https://www.uniprot.org/uniprotkb/P21397/entry"},{"label":"NCBI Gene 4128","url":"https://www.ncbi.nlm.nih.gov/gene/4128"},{"label":"Monoamine oxidase A mediates prostate tumorigenesis and cancer metastasis (J Clin Invest 2014)","url":"https://doi.org/10.1172/JCI70982"}],"tags":["pipeline-gap-target"],"related":[],"cancers":["prostate","prostate-mcrpc"],"sections":[],"technologies":[],"targets":[],"drugs":["itr-251"],"companies":[],"institutions":[],"pathways":[],"terms":[],"trials":[],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"dependsOn":[],"notes":["Prevalence not recorded: HGNC, UniProt and the paper cited give no positivity rate."],"provenance":{"editedBy":"OnCo gap audit, class 5 targets (HGNC REST, UniProt REST, Europe PMC, corpus drug records)","editedOn":"2026-11-03"},"symbol":"MAOA","role":["drug-target"],"sources":[],"specificitySources":[],"hgnc":"HGNC:6833","ensembl":"ENSG00000189221","uniprot":"P21397","entrez":"4128","biology":"Amine oxidase that breaks down neuroactive and vasoactive amines and prefers serotonin as substrate (UniProt P21397).","whereFound":["High-grade prostate cancer (raised expression, doi:10.1172/JCI70982)","Metastatic castration-resistant prostate cancer (ITR-251 trial)"],"targetClass":"enzyme","prevalence":[]},"route":"/targets/maoa/","neighbours":{"cancer":[{"id":"prostate-mcrpc","kind":"cancer","name":"Metastatic castration-resistant prostate cancer","route":"/cancers/prostate-mcrpc/"},{"id":"prostate","kind":"cancer","name":"Prostate cancer","route":"/cancers/prostate/"}],"drug":[{"id":"itr-251","kind":"drug","name":"ITR-251","route":"/drugs/itr-251/"}]}}