"Mind the GAP": RGS1 hinders antitumor lymphocytes

An inflammatory response-related gene signature can predict the prognosis and impact the immune infiltration of multiple myeloma

Multiple myeloma (MM) is a highly heterogeneous and incurable disease. Inflammation plays a vital role in cancer genesis and progression. However, the relationship between inflammatory response-related genes (IRRGs) and the prognosis of MM patients remains unknown. We constructed a IRRGs prognosis model by least absolute shrinkage and selection operator regression analysis. Moreover, clinical multivariate regression was performed to identify clinical implications. Gene set enrichment analysis was implemented to conduct its biological properties. CIBERSORT deconvolution algorithm was utilized to calculate the immune cell infiltration in different risk groups. The flow cytometry was utilized to perform protein expression of prognostic gene. A Six-IRRGs (VCAM1, RGS1, KIT, CD81, BLNK, and BIRC3) prognostic risk model was successfully constructed and validated. The risk model was an independent predictor for overall survival. Enrichment analysis revealed autophagy and PI3K-Akt signaling pathways were enriched in the high-risk group. Furthermore, we found CD81 widely impacted on the infiltration of immune cells, especially on monocytes and macrophages2. At last, the role of CD81 in MM was confirmed to be an adverse prognostic factor in clinical. Our study explores the potential application value of IRRGs in MM. These findings may provide new insights into the treatment for MM patients.

Function and regulation of RGS family members in solid tumours: a comprehensive review

G protein-coupled receptors (GPCRs) play a key role in regulating the homeostasis of the internal environment and are closely associated with tumour progression as major mediators of cellular signalling. As a diverse and multifunctional group of proteins, the G protein signalling regulator (RGS) family was proven to be involved in the cellular transduction of GPCRs. Growing evidence has revealed dysregulation of RGS proteins as a common phenomenon and highlighted the key roles of these proteins in human cancers. Furthermore, their differential expression may be a potential biomarker for tumour diagnosis, treatment and prognosis. Most importantly, there are few systematic reviews on the functional/mechanistic characteristics and clinical application of RGS family members at present. In this review, we focus on the G-protein signalling regulator (RGS) family, which includes more than 20 family members. We analysed the classification, basic structure, and major functions of the RGS family members. Moreover, we summarize the expression changes of each RGS family member in various human cancers and their important roles in regulating cancer cell proliferation, stem cell maintenance, tumorigenesis and cancer metastasis. On this basis, we outline the molecular signalling pathways in which some RGS family members are involved in tumour progression. Finally, their potential application in the precise diagnosis, prognosis and treatment of different types of cancers and the main possible problems for clinical application at present are discussed. Our review provides a comprehensive understanding of the role and potential mechanisms of RGS in regulating tumour progression. Video Abstract.

ScRNA-seq revealed targeting regulator of G protein signaling 1 to mediate regulatory T cells in Hepatocellular carcinoma

BACKGROUND

Regulatory T cells (Tregs) are central to determine immune response outcomes, thus targeting Tregs for immunotherapy is a promising strategy against tumor development and metastasis.

OBJECTIVES

The objective of this study was to identify genes for targeting Tregs to improve the outcome of HCC.

METHODS

We integrated expression data from different samples to remove batch effects and further applied embedding function in Scanpy to conduct sub-clustering of CD4+ T cells in HCC for each of two independent scRNA-seq data. The activity of transcription factors (TFs) was inferred by DoRothEA. Gene expression network analysis was performed in WGCNA R package. We finally used R packages (survminer and survival) to conduct survival analysis. Multiplex immunofluorescence analysis was performed to validate the result from bioinformatic analyses.

RESULTS

We found that regulator of G protein signaling 1 (RGS1) expression was significantly elevated in Tregs compared to other CD4+ T cells in two independent public scRNA-seq datasets, and increased RGS1 predicted inferior clinical outcome of HCC patients. Multiplex immunofluorescence analysis supported that the higher expression of RGS1 in HCC Tregs in tumor tissue compared to it in adjacent tissue. Moreover, RGS1 expression in Tregs was positively correlated with the expression of marker genes of Tregs, C-X-C chemokine receptor 4 (CXCR4), and three CXCR4-dependent genes in both scRNA-seq and bulk RNA-seq data. We further identified that these three genes were selectively expressed in Tregs as compared to other CD4+ T cells. The activities of two transcription factors, recombination signal binding protein for immunoglobulin kappa J region (RBPJ) and yin yang 1 (YY1), were significantly different in HCC Tregs with RGS1 high and RGS1 low.

CONCLUSIONS

Our findings suggested that RGS1 may regulate Treg function possibly through CXCR4 signaling and RGS1 could be a potential target to improve responses for immunotherapy in HCC.

Inhibiting RGS1 attenuates secondary inflammation response and tissue degradation via the TLR/TRIF/NF-κB pathway in macrophage post spinal cord injury

Macrophage-dominated inflammation by the activation of Toll-like receptor (TLR) pathway leads to neurological disruption after spinal cord injury (SCI). Regulator of G-protein signaling 1 (RGS1) is reported to be a regulator in inflammation. The present study thus purposes to identify the unknown role of RGS1 mediating TLR on inflammation post SCI. A mouse model of traumatic SCI was established by a mechanical trauma at T10. The mice underwent SCI and a macrophage line activated by lipopolysaccharide (LPS) were treated with shRNA-RGS1 to elucidate the role of RGS1 in inflammatory progression. The inflammatory factors were measured, and the degree of histology and function protection were determined. The expression levels of RGS1, myeloid differentiation primary response protein 88 (Myd88), (TIR-domain-containing adaptor inducing interferon-β (TRIF), p38, metalloproteinase (MMP)-2, and MMP-9 were determined. RGS1 was robustly increased both in LPS-activated macrophage and SCI mice. The TLR signaling pathway-induced inflammation was suppressed by RGS1 knockdown. shRNA-mediated silence of RGS1 was exhibited a prominent decrease in TNF-α, IL-1β and IL-6 via TLR/TRIF/ nuclear factor kappa-B (NF-κB) axis. Depletion of RGS1 also inhibited MMP-induced tissue degradation via MAPK-p38 pathway in SCI mice. Moreover, suppression of RGS1 improved spinal cord histology and function recovery. These findings suggest that RGS1 regulates inflammation and tissue disruption via TLR/TRIF/NF-κB signaling pathway in mice with SCI, thereby explaining a novel target that regulates macrophage inflammation post SCI.

Enhancing tumor infiltration

Targeting a chemokine receptor inhibitor enhances the trafficking of antitumor T cells into tumors.