G-protein-coupled receptor 137 accelerates proliferation of urinary bladder cancer cells in vitro

Classification of molecular subtypes for colorectal cancer and development of a prognostic model based on necroptosis-related genes

Background

Necroptosis could regulate immunity in cancers, and stratification of colorectal cancer (CRC) subtypes based on key genes related to necroptosis might be a novel strategy for CRC treatment.

Method

The RNA-sequencing data of CRC and other 31 types of cancers were obtained from The Cancer Genome Atlas (TCGA) database. Consensus clustering was performed based on protein-coding genes (PCGs) related to necroptosis score calculated by single sample gene set enrichment analysis (ssGSEA). Module genes showing a significant positive correlation with the necroptosis score were identified by weighted correlation network analysis (WGCNA) and further used to develop a risk stratification model applying least absolute shrinkage and selection operator (LASSO) and Cox regression analysis. The risks score for each sample in CRC cohorts, immunotherapy cohorts and pan-cancer study cohorts was calculated.

Result

Two subgroups (C1 cluster and C2 cluster) of CRC were identified based on the necroptosis score. Compared with C1 cluster, the survival possibility of C2 cluster was greatly reduced, the levels of necroptosis score, immune cell infiltration, immune score and expression of immune checkpoint molecules were significantly increased and immunotherapy response was less active. Low-risk patients defined by the risk model had a significant survival advantage than high-risk counterparts in both CRC and the other 31 cancer types. Furthermore, the risk model was also more efficient than the Tumor Immune Dysfunction and Exclusion (TIDE) tool in predicting OS and immunotherapy response for the samples in the immunotherapy cohort.

Conclusion

CRC patients were classified by necroptosis score-related PCGs, and a risk model was designed to evaluate the immunotherapy and prognosis of patients with CRC. The current molecular subtype and prognostic model could help stratify patients with different risks and predict their prognosis and immunotherapy sensitivity.

Expression profiles of GPR21, GPR39, GPR135, and GPR153 orphan receptors in different cancers

Orphan receptors have unknown endogenous ligands, are expressed in different tissues, and participate in various diseases such as diabetes, hypertension and cancer. We studied the expression profiles of GPR21, GPR39, GPR135 and GPR153 orphan receptors in several tumour tissues. Cervical, breast, skin, prostate, and astrocytoma tissues were analysed for orphan receptor gene expression using Real time PCR analysis. GPR39 is over-expressed in cervical and prostate cancer tissues, and GPR21 and GPR135 receptors are significantly decreased in cervical, breast, skin, prostate, and astrocytoma tissues, when compared with healthy human fibroblasts. In conclusion, GPR21 and GPR135 receptor gene expression is reduced in cancerous tissues. GPR39 may have a role in the development and evolution of cervical and prostate cancer. These data suggest these receptors may be alternative molecules for new diagnostic approaches, and the design of novel therapeutics against oncological pathologies.

Differential CircRNA Expression Signatures May Serve as Potential Novel Biomarkers in Prostate Cancer

Circular RNAs (circRNAs), a recently discovered non-coding RNA, have a number of functions including the regulation of miRNA expression. They have been detected in a number of malignancies including prostate cancer (PCa). The differential expression pattern of circRNAs associated with PCa and androgen receptor (AR) status was investigated in this study. circRNA profiling was performed using a high throughout microarray assay on a panel of prostate cell lines, which consisted of normal, benign, and malignant cells (n = 9). circRNAs were more commonly significantly up-regulated (p < 0.05) than downregulated in malignant cell lines (n = 3,409) vs. benign cell lines (n = 2,949). In a grouped analysis based on AR status, there were 2,127 down-regulated circRNAs in androgen independent cell lines compared to 2,236 in androgen dependent cell lines, thus identifying a potential circRNA signature reflective of androgen dependency. Through a bioinformatics approach, the parental genes associated with the top 10 differentially expressed circRNAs were identified such as hsa_circ_0064644, whose predicted parental gene target is RBMS3, and hsa_circ_0060539, whose predicted gene target is SDC4. Furthermore, we identified three circRNAs associated with the parental gene Caprin1 (hsa_circ_0021652, hsa_circ_0000288, and hsa_circ_0021647). Other studies have shown the importance of Caprin1 in PCa cell survival and drug resistance. Given the modified circRNA expression signatures identified here, these hypothesis generating results suggest that circRNAs may serve as potential putative diagnostic and predictive markers in PCa. However, further validation studies are required to assess the true potential of these markers in the clinical setting.

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.

Small interfering RNA-mediated silencing of G-protein-coupled receptor 137 inhibits growth of osteosarcoma cells

Purpose

Osteosarcoma is the most widespread primary carcinoma in bones. Osteosarcoma cells are highly metastatic and frequently develop resistance to chemotherapy making this disease harder to treat. This identifies an urgent need of novel therapeutic strategies for osteosarcoma. G-Protein-coupled receptor 137 (GPR137) is involved in several human cancers and may be a novel therapeutic target.

Methods

The expression of GPR137 was assessed in one osteoblast and three human osteosarcoma cell lines via the quantitative real-time polymerase chain reaction and western blot assays. Stable GPR137 knockdown cell lines were established using an RNA interference lentivirus system. Viability, colony formation, and flow cytometry assays were performed to measure the effects of GPR137 depletion on cell growth. The underlying molecular mechanism was determined using signaling array analysis and western blot assays.

Results

GPR137 expression was higher in the three human osteosarcoma cell lines, Saos-2, U2OS, and SW1353, than in osteoblast hFOB 1.19 cells. Lentivirus-mediated small interfering RNA targeting GPR137 successfully knocked down GPR137 mRNA and protein expression in both Saos-2 and U2OS cells. In the absence of GPR137, cell viability and colony formation ability were seriously impaired. The extent of apoptosis was also increased in both cell lines. Moreover, AMP-activated protein kinase α, proline-rich AKT substrate of 40 kDa, AKT, and extracellular signal-regulated kinase phosphorylation levels were down-regulated in GPR137 knockdown cells.

Conclusions

The results of this study highlight the crucial role of GPR137 in promoting osteosarcoma cell growth in vitro. GPR137 could serve as a potential therapeutic target against osteosarcoma.