Expression and prognostic role of orphan receptor GPR110 in glioma

Glioma is the most common type of malignancy in the central nervous system, which has a poor prognosis due to its rapid progression and diffuse invasion. Identification of novel biomarkers for glioma would be invaluable for studying disease mechanism and improving prognosis. Orphan G protein-coupled receptor 110 (GPR110) belongs to the subfamily VI of adhesion GPCR. The knowledge of the ligand, signaling pathway or physiology function of GPR110 is poorly elucidated. The potential role of GPR110 as an oncogene in mouse has been recently reported by mutagenesis screen. However, its expression and role in human glioma hasn't been identified. Here in the current study, we initially explored the RNA and protein expression of GPR110 in patients with glioma. Statistical analysis proved that GPR110 was highly expressed in some patients, which was correlated with advanced disease stages. Furthermore, univariate and multivariate analyses revealed its role as an independent prognostic biomarker for the overall survival of glioma patients. Interestingly, cellular studies showed that overexpression or knockdown of GPR110 in U87 cells didn't affect cell proliferation and migration. However, the invasion of U87 cells was significantly enhanced by GPR110-overepxression, while inhibited by GPR110-knockdown. The detailed mechanisms remain further investigation although our results suggested the possible participation of STAT3 instead of ERK in the GPR110 signaling pathways.