Elevated G-Protein Receptor 125 (GPR125) Expression Predicts Good Outcomes in Colorectal Cancer and Inhibits Wnt/β-Catenin Signaling Pathway

Background: G-protein receptor 125 (GPR125), as a transmembrane signal transducer, is involved in regulating cancer development. Although GPR125 is related with several cancers, its role in colorectal cancer (CRC) and the underlying mechanism are still unknown. Here, we investigated the clinical significance of GPR125 in CRC. Material/Methods: We assessed the expression level of GPR125 in CRC tissues by analyzing 3 datasets in the Gene Expression Omnibus (GEO) database and in human samples. The correlation between GPR125 expression and clinicopathological features was further analyzed. Survival analysis was performed to assess the association between GPR125 expression and recurrence-free survival (RFS). Cox logistic regression analysis was used to analyze the role of GPR125 expression in overall survival (OS). Moreover, we activated the Wnt pathway in HCT116 cells to investigate their potential mechanism. Results: Analysis of the GEO database showed that the expression of GPR125 was down-regulated in CRC tissues, consistent with our human samples experiments, and patients with higher GPR125 expression had a longer RFS. Also, we found that high GPR125 expression was associated with better tumor outcomes in clinical stage, metastasis, and KRAS status. Cox logistic regression analysis demonstrated that GPR125 was an independent prognostic factor for favorable outcome. Mechanistically, GPR125 overexpression inhibited the beta-catenin transcriptional activity, and down-regulated the expression levels of the Wnt downstream proteins-Axin2, c-Myc, cylinD1, and lef-1. Conclusions: GPR125 may be a potential prognosis-related anti-oncogene and its effects on inactivating Wnt/beta-catenin signaling pathway might be a key link to inhibiting CRC formation.