{"entity":{"id":"xdh","kind":"target","name":"Xanthine oxidase (XDH)","aka":[],"tldr":"Xanthine oxidase makes uric acid from the breakdown of DNA; allopurinol blocks it to prevent the kidney damage of tumour lysis syndrome when chemotherapy kills many cancer cells at once.","summary":"Xanthine dehydrogenase/oxidase converts hypoxanthine and xanthine, released when nucleic acids from dying cells are broken down, into uric acid. When treatment destroys a large tumour burden quickly, as in acute leukaemia and high-grade lymphoma, the surge of uric acid can crystallise in the kidneys; allopurinol inhibits xanthine oxidase to stop new uric acid forming, and rasburicase breaks down uric acid that already exists. Allopurinol is standard prophylaxis for patients at intermediate risk of tumour lysis syndrome, with rasburicase reserved for high-risk or established cases.","asOf":"2026-09-04","wikipedia":"https://en.wikipedia.org/wiki/Xanthine_oxidase","links":[{"label":"UniProt P47989: XDH","url":"https://www.uniprot.org/uniprotkb/P47989/entry"},{"label":"HGNC:12805 XDH","url":"https://www.genenames.org/data/gene-symbol-report/#!/hgnc_id/HGNC:12805"},{"label":"ChEMBL target CHEMBL1929","url":"https://www.ebi.ac.uk/chembl/explore/target/CHEMBL1929"}],"tags":["chembl-gap"],"related":[],"cancers":["all-leukemia","aml","burkitt-lymphoma","dlbcl"],"sections":[],"technologies":[],"targets":[],"drugs":["rasburicase"],"companies":[],"institutions":[],"pathways":[],"terms":["tumor-lysis-syndrome"],"trials":[],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"dependsOn":[],"notes":[],"symbol":"XDH","role":[],"sources":[],"specificity":"tumour-associated","distribution":"few-types","specificityNote":"Tumour-associated overexpression: HPA finds the RNA group enriched in normal breast, intestine, liver, so the tumour and the normal tissue it comes from share the target and the medicine relies on the difference in level. HPA XDH: RNA group enriched (breast 39 nTPM, intestine 47 nTPM, liver 64 nTPM); no normal tissue stained high. Distribution: 2 cancer families in the corpus carry a prevalence row, label threshold or catalogue link for it (Leukaemia, Lymphoma); Open Targets associates it with 2 specific cancer types at or above 0.5 (leukemia, lymphoma). (Rule 7 of scripts/fetch-target-specificity.ts.)","specificitySources":[{"label":"Human Protein Atlas XDH tissue","url":"https://www.proteinatlas.org/ENSG00000158125-XDH/tissue","note":"RNA tissue and blood lineage specificity, normal tissue antibody staining (version 25.1, CC BY-SA 3.0)"},{"label":"Human Protein Atlas XDH pathology","url":"https://www.proteinatlas.org/ENSG00000158125-XDH/pathology","note":"patients per staining level per cancer type (version 25.1, CC BY-SA 3.0)"},{"label":"Open Targets ENSG00000158125 associations","url":"https://platform.opentargets.org/target/ENSG00000158125/associations","note":"cancer associations at or above 0.5 (CC0)"}],"hgnc":"HGNC:12805","ensembl":"ENSG00000158125","uniprot":"P47989","entrez":"7498","firstDescribed":1993,"firstDescribedBasis":"sequence","firstDescribedNote":"Earliest sequence paper UniProt cites for the protein: Ichida et al, Gene, 1993, \"Cloning of the cDNA encoding human xanthine dehydrogenase (oxidase): structural analysis of the protein and chromosomal location of the gene\".","firstDescribedSource":"https://pubmed.ncbi.nlm.nih.gov/8224915/","biology":"A molybdenum-containing enzyme of purine catabolism in liver and gut; its oxidase form also generates reactive oxygen species.","whereFound":["Liver and intestinal epithelium","Relevant during induction chemotherapy for leukaemia and lymphoma"],"targetClass":"enzyme","prevalence":[{"cancerId":"metastatic-cancer","pct":"host","measure":"Host target: xanthine oxidase in uric acid formation. Not a tumour alteration, so no prevalence applies; the drug acts on normal tissue or on symptoms."}]},"route":"/targets/xdh/","neighbours":{"cancer":[{"id":"all-leukemia","kind":"cancer","name":"Acute lymphoblastic leukaemia","route":"/cancers/all-leukemia/"},{"id":"aml","kind":"cancer","name":"Acute myeloid leukaemia","route":"/cancers/aml/"},{"id":"burkitt-lymphoma","kind":"cancer","name":"Burkitt lymphoma","route":"/cancers/burkitt-lymphoma/"},{"id":"dlbcl","kind":"cancer","name":"Diffuse large B-cell lymphoma","route":"/cancers/dlbcl/"}],"drug":[{"id":"rasburicase","kind":"drug","name":"Rasburicase","route":"/drugs/rasburicase/"}],"term":[{"id":"tumor-lysis-syndrome","kind":"term","name":"Tumour lysis syndrome (TLS)","route":"/terms/tumor-lysis-syndrome/"}]}}