PT  - JOURNAL ARTICLE
AU  - Jan K. Hennigs
AU  - Sarah Minner
AU  - Julia Müller
AU  - Hans Jörg Baumann
AU  - Carsten Bokemeyer
AU  - Guido Sauter
AU  - Hans Klose
TI  - Loss of orphan G protein coupled receptor GPRC5A is associated with metastatic disease and poor survival in patients with adenocarcinomas of the lung
DP  - 2011 Sep 01
TA  - European Respiratory Journal
PG  - p1950
VI  - 38
IP  - Suppl 55
4099  - http://erj.ersjournals.com/content/38/Suppl_55/p1950.short
4100  - http://erj.ersjournals.com/content/38/Suppl_55/p1950.full
SO  - Eur Respir J2011 Sep 01; 38
AB  - Introduction: Orphan G protein coupled receptor (GPCR) 5A from the group C of GPCRs (GPRC5A) has recently been suggested to be a tumor suppressor of lung cancers. First results from knockout mice and human RNA analyses implied an association with adenocarcinomas and poor survival. The aim of the present study was to identify prevalence and clinical significance of GPRC5A protein expression in non-small cell lung cancers (NSCLC).Materials and methods: GPRC5A protein expression was analyzed by immunohistochemistry using a tissue microarray containing samples from more than 2,000 lung cancer patients with clinical follow-up data (Mean: 35.2±34.2 months).Results: GPRC5A expression was absent in 298 (17.4%) of approximately 1,700 analyzable NSCLC (n=792 squamous cell carcinomas, n=471 adenocarcinomas, n=309 large cell carcinomas and n=96 other NSCLC). 41% of all analyzed NSCLC showed moderate to strong cytoplasmic and membranous GPRC5A staining. Staining intensities were inversely correlated with high tumor cell proliferation (p<0.0001) and grading (p<0.05). In adenocarcinomas, absence of GPRC5A was seen in just 20 cases (4.2%) but was strongly associated with metastatic disease and staging (both p<0.0001). Cumulative survival was significantly lower in patients with adenocarcinomas lacking GPRC5A (p<0.01).Conclusions: Loss of GPRC5A is linked to high tumor cell proliferation in NSCLC. In adenocarcinomas of the lung, it is not very frequent but is strongly associated with metastatic disease and poor prognosis. Therefore, GPRC5A expression seems to be an important prognostic factor.