Inhibition of GPR137 suppresses proliferation of medulloblastoma cells in vitro

The Relationship Between Smartphone Addiction and the Interpersonal Competence of Chinese Private College Students: A Moderated Mediation Model

Purpose

As an aspect of the lives of private college students in China, interpersonal competence (IC) is important to their socialization and employment competence. This study aimed to investigate the relationship between Chinese private college students' smartphone addiction (SPA) and IC, the mediating effect of negative emotions (NE), and the moderating effect of psychological resilience (PR).

Samples and Methods

Using simple random sampling, 5473 Chinese private college students (male 74.5%, urban household registration 51.6%, served as a student leader 31.5%) were recruited.

Results

The results showed that (1) SPA positively predicted IC; (2) NE partially mediated the relationship between SPA and IC; and (3) PR moderated the relationships between SPA and NE, NE and IC, SPA and IC.

Conclusion

These findings provide a new perspective to improve Chinese private college students' socialization and their employment competitiveness.

GPR137 inactivates Hippo signaling to promote gastric cancer cell malignancy

As the fifth most common cancer in the world, gastric cancer (GC) ranks as the third major cause of cancer-related death globally. Although surgical resection and chemotherapy still remains the mainstay of potentially curative treatment for GC, chemotherapy resistance and adverse side effects limit their clinical applications. Thus, further investigation of the mechanisms of carcinogenesis in GC and discovery of novel biomarkers is of great concern. We herein report that the elevated expression of GPR137 is correlated with GC. Overexpression of GPR137 potentiates human gastric cancer AGS cell malignancy, including proliferation, migration, invasion, colony formation and xenograft growth in nude mice in vivo, whereas knockout of GPR137 by CRISPR/Cas9 gene editing exerts the opposite effects. Mechanistically, GPR137 could bind to MST, the upstream kinases in Hippo pathway, which disrupts the association of MST with LATS, subsequently activating the transcriptional co-activators, YAP and TAZ, and thereby triggering the target transcription and the alterations in GC cell biological actions consequently. Therefore, our findings may provide with the evidence of developing a potentially novel treatment method with specific target for GC.

GPR137 Inhibits Cell Proliferation and Promotes Neuronal Differentiation in the Neuro2a Cells

The orphan receptor, G protein-coupled receptor 137 (GPR137), is an integral membrane protein involved in several types of cancer. GPR137 is expressed ubiquitously, including in the central nervous system (CNS). We established a GPR137 knockout (KO) neuro2A cell line to analyze GPR137 function in neuronal cells. KO cells were generated by genome editing using clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 and cultured as single cells by limited dilution. Rescue cells were then constructed to re-express GPR137 in GPR137 KO neuro2A cells using an expression vector with an EF1-alpha promoter. GPR137 KO cells increased cellular proliferation and decreased neurite outgrowth (i.e., a lower level of neuronal differentiation). Furthermore, GPR137 KO cells exhibited increased expression of a cell cycle regulator, cyclin D1, and decreased expression of a neuronal differentiation marker, NeuroD1. Additionally, GPR137 KO cells exhibited lower expression levels of the neurite outgrowth markers STAT3 and GAP43. These phenotypes were all abrogated in the rescue cells. In conclusion, GPR137 deletion increased cellular proliferation and decreased neuronal differentiation, suggesting that GPR137 promotes cell cycle exit and neuronal differentiation in neuro2A cells. Regulation of neuronal differentiation by GPR137 could be vital to constructing neuronal structure during brain development.

GPR137 is a promising novel bio-marker for the prognosis of bladder cancer patients

OBJECTIVES

G protein-coupled receptor 137 (GPR137) was reported to be associated with several cancers, but its role in bladder cancer has not been reported. The purpose of this study was to evaluate clinical significance of GPR137 in bladder cancer.

METHODS

The expressions of GPR137 in pathological tissues and corresponding normal tissues from bladder cancer patients were detected via quantitative real time polymerase chain reaction (qRT-PCR). Western blot was performed to detect GPR137 expression in bladder cancer tissues and adjacent normal tissues. Chi-Squared test analyzed the relationship between GPR137 expression and clinical features of bladder cancer patients. Additionally, Kaplan-Meier method was adopted in estimating overall survival of bladder cancer patients. Prognostic value of GPR137 was evaluated through Cox regression analysis.

RESULTS

The expression of GPR137 mRNA and protein in pathological tissues was significantly higher than that in adjacent normal tissues (P < .001). Moreover, similar result was found for bladder cancer patients and healthy controls (P < .001). And GPR137 expression was associated with tumor size (P = .006) and TNM stage (P = .012). The results of Kaplan-Meier analysis suggested that patients with high expression of GPR137 had shorter overall survival time than those with low expression (Log rank test, P = .001). Cox regression analysis indicated that GPR137 could act as an independent biomarker for bladder cancer prognosis (HR = 1.850, 95% CI = 1.272-2.689, P = .001).

CONCLUSION

Abnormal expression of GPR137 is associated with bladder cancer and GPR137 is a potential biomarker for the therapy and prognosis of bladder cancer.

The lysosomal GPCR-like protein GPR137B regulates Rag and mTORC1 localization and activity

Cell growth is controlled by a lysosomal signaling complex containing Rag small GTPases and mTORC1 kinase. Here we carried out a microscopy-based genome-wide human siRNA screen and discovered a lysosome-localized G-protein coupled receptor (GPCR)-like protein, GPR137B, that interacts with Rag GTPases, increases Rag localization and activity, and thereby regulates mTORC1 translocation and activity. High GPR137B expression can recruit and activate mTORC1 in the absence of amino acids. Furthermore, GPR137B also regulates the dissociation of activated Rag from lysosomes, suggesting that GPR137B controls a cycle of Rag activation and dissociation from lysosomes. GPR137B knockout cells exhibited defective autophagy and an expanded lysosome compartment, similar to Rag knockout cells. Like zebrafish RagA mutants, GPR137B mutant zebrafish had upregulated TFEB target gene expression and an expanded lysosome compartment in microglia. Thus, GPR137B is a GPCR-like lysosomal regulatory protein that controls dynamic Rag and mTORC1 localization and activity as well as lysosome morphology.