{"entity":{"id":"grpr","kind":"target","name":"GRPR (gastrin-releasing peptide receptor)","aka":[],"tldr":"GRPR is a hormone receptor abundant in early and hormone-sensitive prostate cancer, imaged and treated with bombesin-like radioligands.","summary":"The gastrin-releasing peptide receptor (GRPR) is a G-protein-coupled receptor for bombesin and GRP whose expression is high in hormone-sensitive prostate cancer and falls with castration resistance. It is overexpressed in primary and hormone-naive prostate cancer, often in PSMA-negative tumours, as well as in ER-positive breast cancer and GIST, which makes it a complementary theranostic target to PSMA. Bombesin-like radioligands exploit it: 68Ga-RM2 PET for imaging and 177Lu-NeoB (Novartis) for therapy are in clinical trials. Because expression declines as disease becomes castration-resistant, GRPR agents may suit earlier disease or PSMA-negative patients rather than replacing PSMA therapy. A newcomer can think of GRPR as a second radioactive address on prostate cancer, useful where PSMA is dim.","asOf":"2026-09-06","wikipedia":"https://en.wikipedia.org/wiki/Gastrin-releasing_peptide_receptor","links":[{"label":"Wikipedia","url":"https://en.wikipedia.org/wiki/Gastrin-releasing_peptide_receptor"}],"tags":["theranostic"],"related":["ga-68","lu-177"],"indications":["prostate"],"sections":[],"technologies":["radioligand-therapy","pet"],"targets":[],"drugs":[],"companies":[],"institutions":[],"pathways":[],"terms":[],"trials":[],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"dependsOn":[],"notes":[],"symbol":"GRPR","hgnc":"HGNC:4609","ensembl":"ENSG00000126010","uniprot":"P30550","entrez":"2925","biology":"G-protein-coupled receptor for bombesin/GRP; expression falls with castration resistance.","whereFound":["Hormone-sensitive prostate cancer","ER+ breast cancer","GIST"],"targetClass":"surface-antigen","prevalence":[{"indicationId":"prostate","pct":100,"measure":"Receptor autoradiography, GRPR in 30 of 30 invasive prostate carcinomas","source":"https://pubmed.ncbi.nlm.nih.gov/10070977/","note":"Markwalder and Reubi 1999 (Cancer Res); receptor density was high in carcinoma and PIN and low or absent in normal and hyperplastic prostate"}]},"route":"/targets/grpr/","neighbours":{"isotope":[{"id":"ga-68","kind":"isotope","name":"Gallium-68","route":"/isotopes/ga-68/"},{"id":"lu-177","kind":"isotope","name":"Lutetium-177","route":"/isotopes/lu-177/"}],"indication":[{"id":"prostate","kind":"indication","name":"Prostate cancer","route":"/indications/prostate/"}],"technology":[{"id":"pet","kind":"technology","name":"PET (positron emission tomography)","route":"/technologies/pet/"},{"id":"radioligand-therapy","kind":"technology","name":"Radioligand therapy (beta emitters)","route":"/technologies/radioligand-therapy/"}],"opportunity":[{"id":"opp-grpr-psma-negative-prostate","kind":"opportunity","name":"GRPR imaging when the PSMA scan is negative","route":"/opportunities/opp-grpr-psma-negative-prostate/"}],"company":[{"id":"life-molecular-imaging","kind":"company","name":"Life Molecular Imaging","route":"/companies/life-molecular-imaging/"}],"idea":[{"id":"idea-bispecific-radioligands","kind":"idea","name":"Bispecific PSMA/GRPR radioligands for discordant prostate cancer lesions","route":"/ideas/idea-bispecific-radioligands/"}],"target":[{"id":"bradykinin-b1-receptor","kind":"target","name":"Bradykinin B1 receptor (B1R)","route":"/targets/bradykinin-b1-receptor/"}]}}