Subtyping of microsatellite stability colorectal cancer reveals guanylate binding protein 2 (GBP2) as a potential immunotherapeutic target

Treatment strategies targeting the phosphoinositide 3-kinase/protein kinase B/mechanistic target of rapamycin pathway against triple-negative breast cancer

Triple negative breast cancer (TNBC) is an exceptionally aggressive subtype of breast cancer with a poor prognosis. TNBC patients have limited treatment options beyond conventional chemotherapy, and they face significant challenges associated with disease recurrence and resistance to chemotherapy. The phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT)/mechanistic target of rapamycin (mTOR) signaling pathway plays a pivotal role in cell proliferation, growth, metabolism, and survival. Its aberrant activation is closely linked to the development and progression of TNBC, as well as treatment response and drug resistance. Currently, numerous targeted drugs specifically inhibiting this signaling pathway are being developed and undergoing clinical trials. These include inhibitors targeting PI3K, AKT, or mTOR individually, as well as dual-target or multi-target inhibitors simultaneously targeting different components of this pathway. Encouragingly, some inhibitors have demonstrated promising potential in clinical trials. This review delves into the therapeutic potential of the PI3K/AKT/mTOR signaling pathway for TNBC and explores prospects for drug discovery.

S-adenosylmethionine metabolism shapes CD8+ T cell functions in colorectal cancer

Metabolite nutrients within the tumor microenvironment shape both tumor progression and immune cell functionality. It remains elusive how the metabolic interaction between T cells and tumor cells results in different anti-cancer immunotherapeutic responses. Here, we use untargeted metabolomics to investigate the metabolic heterogeneity in patients with colorectal cancer (CRC). Our analysis reveals enhanced S-adenosylmethionine (SAM) and S-adenosylhomocysteine (SAH) metabolism in microsatellite stable (MSS) CRC, a subtype known for its resistance to immunotherapy. Functional studies reveal that SAM and SAH enhance the initial activation and effector functions of CD8+ T cells. Instead, cancer cells outcompete CD8+ T cells for SAM and SAH availability to impair T cell survival. In vivo, SAM supplementation promotes T cell proliferation and reduces exhaustion of the tumor-infiltrating CD8+ T cells, thus suppressing tumor growth in tumor-bearing mice. This study uncovers the metabolic crosstalk between T cells and tumor cells, which drives the development of tumors resistant to immunotherapy.

Differential Cytotoxicity of Surface-Functionalized Silver Nanoparticles in Colorectal Cancer and Ex-Vivo Healthy Colonocyte Models

Background/Objectives: Engineered nanomaterials, particularly silver nanoparticles (AgNPs), have emerged as promising tools in oncology due to their ability to enhance tumor targeting and minimize off-target effects. This study investigates the cytotoxic effects of two different types of AgNPs-citrate-coated (AgNPs-cit) and EG6OH-coated (AgNPs-EG6OH)-on colorectal cancer (CRC) cell lines and healthy colonocytes, aiming to assess their potential as selective therapeutic agents. Methods: AgNPs-cit and AgNPs-EG6OH were synthesized and characterized for size and surface properties. LoVo (microsatellite instability-high) and HT-29 (microsatellite stable) CRC cell lines, along with primary colonocyte cultures from healthy mucosal tissues, were exposed to these nanoparticles. Cytotoxicity was assessed through MTT assays, while morphological changes were observed using fluorescence microscopy. Internalization of the nanoparticles was evaluated by confocal microscopy. Results: AgNPs-cit exhibited significant cytotoxicity in LoVo cells, reducing viability and inducing morphological changes indicative of programmed cell death, especially after 48 h of exposure. In contrast, AgNPs-EG6OH showed minimal effects on LoVo cells and no significant toxicity on HT-29 cells or primary colonocytes. Confocal microscopy confirmed nanoparticle internalization, with surface functionalization influencing the distribution patterns within cells. Conclusions: This study demonstrates that surface functionalization significantly influences the cytotoxicity of AgNPs, with citrate-coated nanoparticles showing selective effects on microsatellite instability-high CRC cells. These findings underscore the potential of surface-modified nanoparticles for targeted cancer therapy and highlight the importance of tailoring nanoparticle design to optimize therapeutic efficacy while minimizing off-target effects.

Transcriptomics of Various Diseases Reveals the Core Role of Immune System Pathways in Retinal Damage Repair and Nerve Regeneration

Retinal ganglion cells (RGCs) are the only neuronal bridges connecting retinal inputs to the brain's visual processing centers, enabling visual perception. The axon of RGCs forms the optic nerve, which transmits visual information to the visual cortex. Damage to RGCs and their axons results in irreversible visual impairment. Acute retinal damage is commonly induced by conditions such as optic nerve compression, glaucoma, and optic neuritis, for which effective clinical treatments are currently unavailable. Therefore, understanding the response of RGCs and their axons to injury is crucial for the development of potential treatments. This study utilizes multiple models including optic nerve crush (ONC), acute intraocular pressure (IOP) elevation, and local lipopolysaccharide (LPS) injection into the optic nerve to mimic eye diseases. Three days post-surgery, mice underwent retinal isolation followed by bulk-RNA sequencing to analyze differential gene expression among models. Using thresholds of |Log2 fold change (FC)|> 2 and p-value < 0.05, the significant gene expression changes observed in each model were as follows: ONC (upregulated, 456; downregulated, 84), IOP (upregulated, 1946; downregulated, 655), and LPS (upregulated, 219; downregulated, 94). Gene ontology (GO) analysis of the upregulated genes unexpectedly revealed that immune system pathways were the primary shared targets across all three models. In contrast, the downregulated genes exhibited model-specific enrichment: synaptic components and functions in IOP, neurogenesis and neuronal development in ONC, and inflammation and antioxidant in LPS. These findings were further confirmed by Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis. This suggests that managing immune activation is essential for treating acute retinal injury, and therapeutic strategies should address model-specific targets as well. Notably, 39 genes intersected across the models, and the protein-protein interaction (PPI) network identified Ccl5 as a key hub gene, underscoring its critical role in the pathophysiology of all three diseases.

Microsatellite-Stable Gastric Cancer Can be Classified into 2 Molecular Subtypes with Different Immunotherapy Response and Prognosis Based on Gene Sequencing and Computational Pathology

Most patients with gastric cancer (GC) exhibit microsatellite stability, yet comprehensive subtyping for prognostic prediction and clinical treatment decisions for microsatellite-stable GC is lacking. In this work, RNA-sequencing gene expression data and clinical information of patients with microsatellite-stable GC were obtained from The Cancer Genome Atlas (TCGA) and the Gene Expression Omnibus (GEO) databases. We employed several machine learning methods to develop and validate a signature based on immune-related genes (IRGs) for subtyping patients with microsatellite-stable GC. Moreover, 2 deep learning models based on the Vision Transformer (ViT) architecture were developed to predict GC tumor tiles and identify microsatellite-stable GC subtypes from digital pathology slides. Microsatellite status was evaluated by immunohistochemistry, and prognostic data as well as hematoxylin and eosin whole-slide images were collected from 105 patients with microsatellite-stable GC to serve as an independent validation cohort. A signature comprising 5 IRGs was established and validated, stratifying patients with microsatellite-stable GC into high-risk (microsatellite-stable-HR) and low-risk (microsatellite-stable-LR) groups. This signature demonstrated consistent performance, with areas under the receiver operating characteristic curve (AUC) of 0.65, 0.70, and 0.70 at 1, 3, and 5 years in the TCGA cohort, and 0.70, 0.60, and 0.62 in the GEO cohort, respectively. The microsatellite-stable-HR subtype exhibited higher levels of tumor immune dysfunction and exclusion, suggesting a greater potential for immune escape compared with the microsatellite-stable-LR subtype. Moreover, the microsatellite-stable-HR/LR subtypes showed differential sensitivities to various therapeutic drugs. Leveraging morphologic differences, the tumor recognition segmentation model achieved an impressive AUC of 0.97, whereas the microsatellite-stable-HR/LR identification model effectively classified microsatellite-stable-HR/LR subtypes with an AUC of 0.94. Both models demonstrated promising results in classifying patients with microsatellite-stable GC in the external validation cohort, highlighting the strong ability to accurately differentiate between microsatellite-stable GC subtypes. The IRG-related microsatellite-stable-HR/LR subtypes had the potential to enhance outcome prediction accuracy and guide treatment strategies. This research may optimize precision treatment and improve the prognosis for patients with microsatellite-stable GC.

CpG-Based Nanovaccines Enhance Ovarian Cancer Immune Response by Gbp2-Mediated Remodeling of Tumor-Associated Macrophages

CpG oligodeoxynucleotides (CpG), as an immunoadjuvant, can facilitate the transformation of tumor-associated macrophages (TAMs)into tumoricidal M1 macrophages. However, the accumulation of free CpG in tumor tissues remains a substantial challenge. To address this, a nanovaccine (PLGA-CpG@ID8-M) is engineered by encapsulating CpG within PLGA using ID8 ovarian cancer cell membranes (ID8-M). This nanovaccine demonstrates remarkable efficacy in reprogramming TAMs in ovarian cancer and significantly extends survival in ID8-bearing mice. Notably, these findings indicate that the nanovaccine can also mitigate chemotherapy-induced immunosuppression by increasing the proportion of M1-like TAMs and reducing the expression of CD47 on tumor cells, thereby achieving a synergistic effect in tumor immunotherapy. Mechanistically, through transcriptome sequencing (RNA-seq), single-cell RNA sequencing (scRNA-seq), and mass spectrometry-based proteomics, it is elucidated that the nanovaccine enhances the expression of Gbp2 and promotes the recruitment of Pin1, which activates the NFκB signaling pathway, leading to the M1 polarization of TAMs. Furthermore, macrophages with elevated Gbp2 expression significantly inhibit tumor growth in both ID8 ovarian cancer and 4T1 breast cancer models. Conversely, targeting Gbp2 diminishes the antitumor efficacy of the nanovaccine in vivo. This study offers an innovative approach to immunotherapy and elucidates a novel mechanism (Gbp2-Pin1-NFκB pathway) for remodeling TAMs.

Unveiling the power of Treg.Sig: a novel machine-learning derived signature for predicting ICI response in melanoma

Background

Although immune checkpoint inhibitor (ICI) represents a significant breakthrough in cancer immunotherapy, only a few patients benefit from it. Given the critical role of Treg cells in ICI treatment resistance, we explored a Treg-associated signature in melanoma, which had never been elucidated yet.

Methods

A new Treg signature, Treg.Sig, was created using a computational framework guided by machine learning, utilizing transcriptome data from both single-cell RNA-sequencing (scRNA-seq) and bulk RNA-sequencing (bulk-seq). Among the 10 Treg.Sig genes, hub gene STAT1's function was further validated in ICI resistance in melanoma mice receiving anti-PD-1 treatment.

Results

Treg.Sig, based on machine learning, was able to forecast survival outcomes for melanoma across training dataset and external test dataset, and more importantly, showed superior predictive power than 51 previously established signatures. Analysis of the immune profile revealed that groups with high Treg.Sig levels exhibited immune-suppressive conditions, with inverse correlations observed between Treg.Sig and anti-cancer immune responses. Notably, among the 10 Treg.Sig genes, hub gene STAT1 mutation harbored lower response rate in ICIs-treated cohort. Mechanistically, STAT1 impinged on ICI resistances by modulating the phenotypic switch in N2 neutrophil polarization in melanoma mice receiving anti-PD-1 therapy, which affects overall survival.

Conclusion

The study developed a promising Treg.Sig signature that predicts ICI response of melanomas and could be used for selecting patients for immunotherapy. Meanwhile, our study potentially paves the way for overcoming immune resistance by targeting Treg-associated genes.

Indole-3-carbinol prevented tumor progression and potentiated PD1ab therapy by upregulating PTEN in colorectal cancer

PURPOSE

Colorectal cancer (CRC) is among the most common malignant tumors worldwide, posing a significant threat to human health. Most patients with CRC are refractory to existing treatment regimens, such as immune checkpoint blockades (ICBs), yielding unsatisfactory outcomes. This study aimed to explore the effect and mechanism of a natural product, indole-3-carbinol (I3C), in CRC pathogenesis and immunotherapy.

METHODS

A series of in vitro experiments, such as the cell counting kit-8 and wound healing assays, were used to assess the proliferative, colony-formating and migratory capacity of human CRC cells after I3C treatment. In vivo experiment, xenograft growth assay was conducted to verify the effect of I3C on CRC. Hematoxylin-eosin (HE) staining was utilized to evaluated the toxic effect of I3C. Immunohistochemical staining was used to detect CD8+ T cell infiltration. Subcutaneous CRC models constructed in immunocompetent mice were used to test the effects of I3C treatment in combination with PD1ab therapy. The Human Protein Atlas (HPA) database, cell transfection, and quantitative real-time polymerase chain reaction (RT-qPCR) experiments were used to explore the mechanism of I3C in CRC.

RESULTS

I3C significantly inhibited CRC cell proliferation, colony formation, and migration capacity in vitro and in vivo. The result of HE staining indicated that I3C exert no significant toxic effect on heart, liver and kidney. HPA data analysis and RT-qPCR results demonstrated that PTEN expression was lower in CRC tissues than in normal tissues or cells. Besides, I3C exerted antitumor activity and promoted CD8+ T cell infiltration by upregulating PTEN expression. Consequently, I3C, in conjunction with PD1ab therapy, synergistically enhanced the antitumor effect on CRC in immunocompetent mice.

CONCLUSIONS

These findings suggested that by upregulating PTEN expression, the natural product I3C strongly prevented tumor progression and exerted no systematic toxicity in the major organs such as heart, kidney and liver. Furthermore, I3C significantly enhanced PD1ab therapeutic effect in CRC, highlighting its role as a candidate preventive or therapeutic compound for CRC therapy, especially in combination with PD1ab therapy. Further clinical trial should be conducted in the future.

SET facilitates immune escape of microsatellite stability colorectal cancer by inhibiting c-Myc degradation

Microsatellite stability (MSS) colorectal cancer (CRC) exhibits a low mutation load and poor immunogenicity, contributing to immune escape of tumor cells and less benefit from immune checkpoint blockade (ICB) treatment. The mechanisms underlying immunotherapeutic resistance in MSS CRC remain to be elucidated. Here, we identified that nuclear proto-oncogene SET is significantly higher expressed in MSS CRC compared to microsatellite instability (MSI) CRC and facilitates immune escape of MSS CRC. Mechanistically, SET represses the expression of C-C motif chemokine ligand 5 (CCL5) and upregulates mismatch repair (MMR) proteins expression in a c-Myc-dependent manner, which inhibits infiltration and migration of CD8+ T cells to tumor tissues and results in low immunogenicity in MSS CRC. In addition, we found that SET impairs ubiquitination and proteasomal degradation of c-Myc by disrupting the interaction between E3 ligase FBXW7 and c-Myc. Moreover, SET inhibition enhances the response to immunotherapy in MSS CRC in vivo. Overall, this study reveals the critical roles and posttranslational regulatory mechanism of SET in immune escape and highlights the SET/c-Myc axis as a potential target for immunotherapy of MSS CRC that have implications for targeting a unique aspect of this disease.

Crosstalk between GBP2 and M2 macrophage promotes the ccRCC progression

Clear cell renal cell carcinoma (ccRCC) represents a highly heterogeneous kidney malignancy associated with the poorest prognosis. The metastatic potential of advanced ccRCC tumors is notably high, posing significant clinical challenges. There is an urgent imperative to develop novel therapeutic approaches to address ccRCC metastasis. Recent investigations indicated a potential association between GBP2 and tumor immunity. However, the precise functional role of GBP2 in the progression of ccRCC remains poorly understood. The present study revealed a strong correlation between GBP2 and M2 macrophages. Specifically, our findings demonstrated that the inhibition of GBP2 significantly impedes the migratory and invasive capabilities of ccRCC cells. We observed that the presence of M2 macrophages can reverse the effects of GBP2 knockdown on tumor cell migration and invasion. Mechanistically, we demonstrated that M2 macrophages promote the expression of the GBP2/p-STAT3 and p-ERK axis in tumor cells through the secretion of interleukin-10 (IL-10) and transforming growth factor-β (TGF-β), thereby substantially enhancing the migratory and invasive capacities of the tumor cells. Simultaneously, we have identified that GBP2 promotes the polarization of macrophages to the M2 phenotype by stimulating the secretion of interleukin-18 (IL-18). In summary, our investigation anticipates that the GBP2/IL-18/M2 macrophages/IL-10 and the TGF-β/GBP2, p-STAT3, p-ERK loop plays a crucial role in ccRCC metastasis. The collective findings from our research underscore the significant role of GBP2 in tumor immunity and emphasize the potential for modulating GBP2 as a promising therapeutic strategy for targeting ccRCC metastasis.

Integrative analysis of the immunological significances of guanylate binding protein family genes in microsatellite stability colorectal cancer

Background

Microsatellite stability (MSS) colorectal cancer (CRC) has poor sensitivity to immunotherapy and its underlying mechanisms are still unclear. Guanylate binding proteins (GBPs) are a family of GTPase involving innate immune responses by providing defense against invading microbes and pathogens. However, the immunological significances of GBPs in MSS CRC remain unknown.

Methods

We utilized bioinformatic tools to comprehensively analysis the expression pattern, clinical relevance, prognostic value, biological function, and immunoregulation effect of distinct GBP members in MSS CRC.

Results

The expression of all seven GBPs in MSS samples are remarkably decreased compared to microsatellite instability-high (MSI-H) samples. Among them, GBP1/2/4/5 are obviously correlated with distant metastasis status. High expression of GBP1/4/5/6 was remarkably related to favorable overall survival (OS) and progression-free survival (PFS) in CRC patients with MSS tumor. Subsequent enrichment analysis revealed that Interferon-gamma (IFN-γ) and NOD-like receptor signaling are the most relevant functions. Besides, the expression patterns of GBPs are remarkably associated with several tumor infiltrated immune cells (e.g. regulatory T cells, CD4+ T cells, and macrophages) and diverse immunoregulatory molecules (e.g. immune checkpoint biomarkers (ICBs) and major histocompatibility complex (MHC) molecules). Moreover, high GBP1/2/4/5 expression predicted better immunotherapy responsiveness in immunotherapy cohorts.

Conclusion

These findings might provide novel insights for the identification of therapeutic targets and potential prognostic biomarkers of GBP family in CRC with MSS samples.

DNA hypo-methylation and expression of GBP4 induces T cell exhaustion in pancreatic cancer

Immunotherapy for pancreatic ductal carcinoma (PDAC) remains disappointing due to the repressive tumor microenvironment and T cell exhaustion, in which the roles of interferon-stimulated genes were largely unknown. Here, we focused on a typical interferon-stimulated gene, GBP4, and investigated its potential diagnostic and therapeutic value in pancreatic cancer. Expression analysis on both local samples and public databases indicated that GBP4 was one of the most dominant GBP family members present in the PDAC microenvironment, and the expression level of GBP4 was negatively associated with patient survival. We then identified DNA hypo-methylation in regulatory regions of GBP4 in PDAC, and validated its regulatory role on GBP4 expression via performing targeted methylation using dCas9-SunTag-DNMAT3A-sgRNA-targeted methylation system on selected DNA locus. After that, we investigated the downstream functions of GBP4, and chemotaxis assays indicated that GBP4 overexpression significantly improved the infiltration of CD8+T cells, but also induced upregulation of immune checkpoint genes and T cell exhaustion. Lastly, in vitro T cell killing assays using primary organoids suggested that the PDAC samples with high level of GBP4 expression displayed significantly higher sensitivity to anti-PD-1 treatment. Taken together, our studies revealed the expression patterns and epigenetic regulatory mechanisms of GBP4 in pancreatic cancer and clarified the effects of GBP4 on T cell exhaustion and antitumor immunology.

CENPA facilitates glioma stem cell stemness and suppress ferroptosis to accelerate glioblastoma multiforme progression by promoting GBP2 transcription

The function of glioma stem cells (GSCs) is closely related to the progression of glioblastoma multiforme (GBM). Centromere protein A (CENPA) has been confirmed to be related to the poor prognosis of GBM patients. However, whether CENPA regulates GSCs function to mediate GBM progression is still unclear. GSCs were isolated from GBM cells. The expression of CENPA and guanylate-binding protein 2 (GBP2) was examined by quantitative real-time PCR and western blot. GSCs proliferation and stemness were assessed using EdU assay and sphere formation assay. Cell ferroptosis was evaluated by detecting related factors. The interaction between CENPA and GBP2 was analyzed by ChIP assay and dual-luciferase reporter assay. Animal experiments were conducted to measure the effect of CENPA knockdown on the tumorigenicity of GSCs in vivo. CENPA was upregulated in GBM tissues and GSCs. CENPA knockdown inhibited GSCs proliferation, stemnness, and promoted ferroptosis. GBP2 was overexpressed in GBM tissues and GSCs, and CENPA enhanced GBP2 transcription by binding to its promoter region. CENPA overexpression accelerated GSCs proliferation and stemnness and suppressed ferroptosis, while GBP2 knockdown reversed these effects. Downregulation of CENPA reduced the tumorigenicity of GSCs by decreasing GBP2 expression in vivo. In conclusion, CENPA enhanced GBP2 transcription to increase its expression, thus accelerating GSCs proliferation and stemnness and repressing ferroptosis. Our findings promote a new idea for GBM treatment.

Prognostic value of dynamic changes of pre- and post-operative tumor markers in colorectal cancer

BACKGROUND

Colorectal cancer (CRC) prognosis assessment is vital for personalized treatment plans. This study investigates the prognostic value of dynamic changes of tumor markers CEA, CA19-9, CA125, and AFP before and after surgery and constructs prediction models based on these indicators.

METHODS

A retrospective clinical study of 2599 CRC patients who underwent radical surgery was conducted. Patients were randomly divided into training (70%) and validation (30%) datasets. Univariate and multivariate Cox regression analyses identified independent prognostic factors, and nomograms were constructed.

RESULTS

A total of 2599 CRC patients were included in the study. Patients were divided into training (70%, n = 1819) and validation (30%, n = 780) sets. Univariate and multivariate Cox regression analyses identified age, total number of resected lymph nodes, T stage, N stage, the preoperative and postoperative changes in the levels of CEA, CA19-9, and CA125 as independent prognostic factors. When their postoperative levels are normal, patients with elevated preoperative levels have significantly worse overall survival. However, when the postoperative levels of CEA/CA19-9/CA125 are elevated, whether their preoperative levels are elevated or not has no significance for prognosis. Two nomogram models were developed, and Model I, which included CEA, CA19-9, and CA125 groups, demonstrated the best performance in both training and validation sets.

CONCLUSION

This study highlights the significant predictive value of dynamic changes in tumor markers CEA, CA19-9, and CA125 before and after CRC surgery. Incorporating these markers into a nomogram prediction model improves prognostic accuracy, enabling clinicians to better assess patients' conditions and develop personalized treatment plans.

Transcriptomics-based exploration of shared M1-type macrophage-related biomarker in acute kidney injury after kidney transplantation and acute rejection after kidney transplantation

BACKGROUND

Macrophage type 1 (M1) cells are associated with both acute kidney injury (AKI) during kidney transplantation and acute rejection (AR) after kidney transplantation. Our study explored M1-related biomarkers involved in both AKI and AR and their potential biological functions.

METHODS

Based on the Gene Expression Omnibus (GEO) database, the immune cell infiltration levels and differentially expressed genes were examined in AKI and AR in the kidney transplantation; M1-related genes shared in AKI and AR were identified using weighted gene co-expression analysis (WGCNA) system. Subsequently, protein-protein interaction (PPI) networks and machine learning methods to identify Hub genes and construct diagnostic models. Both AKI model and AR rat models were built to validate the expressions of Hub genes and test the injury phenotype, oxidative stress markers, and inflammatory factors. Finally, the transcription factor (TF)-Hub gene and micro-RNA (miRNA)-Hub gene regulatory networks were constructed based on identified Hub genes.

RESULTS

Out of 2167 differential expression genes (DEGs) in AKI and 2100 DEGs in AR, four M1-related Hub genes were obtained by PPI networks and machine learning methods, namely GBP2, TYROBP, CCR5, and TLR8. The calibration curves in the nomogram diagnostic model for these four Hub genes suggested the same predictive probability as an ideal model for AKI and AR after kidney transplantation (AUC values of the area under the ROC curve were all >0.7). The same observations were confirmed in ischemia reperfusion injury (IRI) and AR rat models by identifying common four Hub genes (GBP2, TYROBP, TLR8, and CCR5). Western blots showed that these four Hub genes were significantly different in rat models of IRI and AR (all p<0.05). Compared with the control group, IRI and AR groups showed aggravated histopathological damage and increased secretion of oxidative stress markers and inflammatory factors in rat kidneys (all p<0.05). Finally, TF-Hub and miRNA-Hub gene regulatory networks were constructed to provide a theoretical basis for the regulation of Hub genes.

CONCLUSION

We identified four macrophage M1-related Hub genes shared among AKI and AR after kidney transplantation. These genes may be considered for diagnosis of AKI and AR after kidney transplantation.

The role of CD8+ T-cells in colorectal cancer immunotherapy

Immunotherapy has been an advanced and effective approach to treating various types of solid tumors in recent years, and the most successful strategy is immune checkpoint inhibitors (ICIs), which have shown beneficial effects in patients with colorectal cancer (CRC). Drug resistance to ICIs is usually associated with CD8+ T-cells targeting tumor antigens; thus, CD8+ T-cells play an important role in immunotherapy. Unfortunately, Under continuous antigen stimulation, tumor microenvironment(TME), hypoxia and other problems it leads to insufficient infiltration of CD8+ T-cells, low efficacy and mechanism exhaustion, which have become obstacles to immunotherapy. Thus, this article describes the relationship between CRC and the immune system, focuses on the process of CD8+ T-cells production, activation, transport, killing, and exhaustion, and expounds on related mechanisms leading to CD8+ T-cells exhaustion. Finally, this article summarizes the latest strategies and methods in recent years, focusing on improving the infiltration, efficacy, and exhaustion of CD8+ T-cells, which may help to overcome the barriers to immunotherapy.

Comprehensive analysis of the relationship between ubiquitin-specific protease 21 (USP21) and prognosis, tumor microenvironment infiltration, and therapy response in colorectal cancer

BACKGROUND

Ubiquitin-specific proteases family is crucial to host immunity against pathogens. However, the correlations between USP21 and immunosurveillance and immunotherapy for colorectal cancer (CRC) have not been reported.

METHODS

The differential expression of USP21 between CRC tissues and normal tissues was analyzed using multiple public databases. Validation was carried out in clinical samples through qRT-PCR and IHC. The correlation between USP21 and the prognosis, as well as clinical pathological characteristics of CRC patients, was investigated. Moreover, cell models were established to assess the influence of USP21 on CRC growth and progression, employing CCK-8 assays, colony formation assays, and wound-healing assays. Subsequently, gene set variation analysis (GSVA) was used to explore the potential biological functions of USP21 in CRC. The study also examined the impact of USP21 on cytokine levels and immune cell infiltration in the tumor microenvironment (TME). Finally, the effect of USP21 on the response to immunotherapy and chemotherapy in CRC was analyzed.

RESULTS

The expression of USP21 was significantly upregulated in CRC. High USP21 is correlated with poor prognosis in CRC patients and facilitates the proliferation and migration capacities of CRC cells. GSVA indicated an association between low USP21 and immune activation. Moreover, low USP21 was linked to an immune-activated TME, characterized by high immune cell infiltration. Importantly, CRC with low USP21 exhibited higher tumor mutational burden, high PD-L1 expression, and better responsiveness to immunotherapy and chemotherapeutic drugs.

CONCLUSION

This study revealed the role of USP21 in TME, response to therapy, and clinical prognosis in CRC, which provided novel insights for the therapeutic application in CRC.

Immunotherapy of microsatellite stable colorectal cancer: resistance mechanisms and treatment strategies

In recent years, immunotherapy strategies based on immune checkpoint inhibitors have yielded good efficacy in colorectal cancer (CRC)especially in colorectal cancer with microsatellite instability-high. However, microsatellite-stable (MSS) CRCs account for about 85% of CRCs and are resistant to immunotherapy. Previous studies have shown that compared with MSS CRC, high microsatellite instability CRC possesses a higher frequency of mutations and can generate more neoantigens. Therefore, improving the sensitivity of immunotherapy to MSS CRC is a hot topic which is crucial for the treatment of MSS CRC. This review aims to discuss the factors contributing to MSS CRC insensitivity to immunotherapy and explored potential solutions to overcome immunotherapy resistance.

Pseudomonas aeruginosa outer membrane vesicle-packed sRNAs can enter host cells and regulate innate immune responses

Bacterial outer membrane vesicles (OMVs) can package and deliver virulence factors into host cells, which is an important mechanism mediating host-pathogen interactions. It has been reported that small RNAs (sRNAs) can be packed into OMVs with varying relative abundance, which might affect the function and/or stability of host mRNAs. In this study, we used OptiPrep density gradient ultra-high-speed centrifugation to purify OMVs from Pseudomonas aeruginosa. Next, the sequences and abundance of sRNAs were detected by using Small RNA-Seq. In particular, sRNA4518698, sRNA2316613 and sRNA809738 were the three most abundant sRNAs in OMVs, which are all fragments of P. aeruginosa non-coding RNAs. sRNAs were shielded within the interior of OMVs and remained resistant to external RNase cleavage. The miRanda and RNAhybrid analysis demonstrated that those sRNAs could target a large number of host mRNAs, which were enriched in host immune responses by the functions of GO and KEGG enrichment. Experimentally, we demonstrated that the transfection of synthetic sRNA4518698, sRNA2316613, or sRNA809738 could reduce the expression of innate immune response genes in RAW264.7 cells. Together, we demonstrated that P. aeruginosa OMVs sRNAs can regulate innate immune responses. This study uncovered a mechanism in which the OMVs regulate host responses by transferring bacterial sRNAs.

Enteric glial cell network function is required for epithelial barrier restitution following intestinal ischemic injury in the early postnatal period

Ischemic damage to the intestinal epithelial barrier, such as in necrotizing enterocolitis or small intestinal volvulus, is associated with higher mortality rates in younger patients. We have recently reported a powerful pig model to investigate these age-dependent outcomes in which mucosal barrier restitution is strikingly absent in neonates but can be rescued by direct application of homogenized mucosa from older, juvenile pigs by a yet-undefined mechanism. Within the mucosa, a postnatally developing network of enteric glial cells (EGCs) is gaining recognition as a key regulator of the mucosal barrier. Therefore, we hypothesized that the developing EGC network may play an important role in coordinating intestinal barrier repair in neonates. Neonatal and juvenile jejunal mucosa recovering from surgically induced intestinal ischemia was visualized by scanning electron microscopy and the transcriptomic phenotypes were assessed by bulk RNA sequencing. EGC network density and glial activity were examined by Gene Set Enrichment Analysis, three-dimensional (3-D) volume imaging, and Western blot and its function in regulating epithelial restitution was assessed ex vivo in Ussing chamber using the glia-specific inhibitor fluoroacetate (FA), and in vitro by coculture assay. Here we refine and elaborate our translational model, confirming a neonatal phenotype characterized by a complete lack of coordinated reparative signaling in the mucosal microenvironment. Furthermore, we report important evidence that the subepithelial EGC network changes significantly over the early postnatal period and demonstrate that the proximity of a specific functional population of EGC to wounded intestinal epithelium contributes to intestinal barrier restitution following ischemic injury.NEW & NOTEWORTHY This study refines a powerful translational pig model, defining an age-dependent relationship between enteric glia and the intestinal epithelium during intestinal ischemic injury and confirming an important role for enteric glial cell (EGC) activity in driving mucosal barrier restitution. This study suggests that targeting the enteric glial network could lead to novel interventions to improve recovery from intestinal injury in neonatal patients.

Exploring the immune microenvironment of osteosarcoma through T cell exhaustion-associated gene expression: a study on prognosis prediction

Background

Osteosarcoma is a highly aggressive type of bone cancer with a poor prognosis. In the tumor immune microenvironment, T-cell exhaustion can occur due to various factors, leading to reduced tumor-killing ability. The purpose of this study was to construct a prognostic model based on T-cell exhaustion-associated genes in osteosarcoma.

Methods

Patient data for osteosarcoma were retrieved from the TARGET and GEO databases. Consensus clustering was employed to identify two novel molecular subgroups. The dissimilarities in the tumor immune microenvironment between these subgroups were evaluated using the "xCell" algorithm. GO and KEGG analyses were conducted to elucidate the underlying mechanisms of gene expression. Predictive risk models were constructed using the least absolute shrinkage and selection operator algorithm and Cox regression analysis. To validate the prognostic significance of the risk gene expression model at the protein level, immunohistochemistry assays were performed on osteosarcoma patient samples. Subsequently, functional analysis of the key risk gene was carried out through in vitro experimentation.

Results

Four gene expression signatures (PLEKHO2, GBP2, MPP1, and VSIG4) linked to osteosarcoma prognosis were identified within the TARGET-osteosarcoma cohort, categorizing patients into two subgroups. The resulting prognostic model showed strong predictive capability, with area under the receiver operating characteristic curve (AUC) values of 0.728/0.740, 0.781/0.658, and 0.788/0.642 for 1, 3, and 5-year survival in both training and validation datasets. Notably, patients in the low-risk group had significantly higher stromal, immune, and ESTIMATE scores compared to high-risk counterparts. Additionally, a nomogram was developed, exhibiting high accuracy in predicting the survival outcome of osteosarcoma patients. Immunohistochemistry, Kaplan-Meier, and time-dependent AUC analyses consistently supported the prognostic value of the risk model within our osteosarcoma patient cohort. In vitro experiments provided additional validation by demonstrating that the downregulation of GBP2 promoted the proliferation, migration, and invasion of osteosarcoma cells while inhibiting apoptosis.

Conclusion

The current study established a prognostic signature associated with TEX-related genes and elucidated the impact of the pivotal gene GBP2 on osteosarcoma cells via in vitro experiments. Consequently, it introduces a fresh outlook for clinical prognosis prediction and sets the groundwork for targeted therapy investigations in osteosarcoma.

Perioperative immune checkpoint inhibition for colorectal cancer: recent advances and future directions

For colorectal cancer (CRC), surgical resection remains essential for achieving good prognoses. Unfortunately, numerous patients with locally advanced CRC and metastatic CRC failed to meet surgical indications or achieve pathological complete response after surgery. Perioperative therapy has been proven to effectively lower tumor staging and reduce recurrence and metastasis. Immune checkpoint inhibitors (ICIs) have shown unprecedented prolongation of survival time and satisfactory safety in patients with high microsatellite instability/deficient mismatch repair (MSI-H/dMMR), while the therapeutic effect obtained by patients with mismatch repair-proficient or microsatellite stable (pMMR/MSS) was considered minimal. However, recent studies found that certain CRC patients with dMMR/MSI-H presented intrinsic or acquired immune resistance, and pMMR/MSS CRC patients can also achieve better efficacy. Therefore, more predictors are required for screening patients with potential clinical benefits. Since the discovery of synergistic effects between immunotherapy, chemotherapy, and radiotherapy, different immunotherapy-based therapies have been applied to the perioperative therapy of CRC in an increasing number of research. This review comprehensively summarized the past and current progress of different combinations of immunotherapy in perioperative clinical trials for CRC, focusing on the efficacy and safety, and points out the direction for future development.

Case Report: A management strategy and clinical analysis of primary squamous cell carcinoma of the colon

Primary colorectal squamous cell carcinoma (CSCC) is a rare pathological subtype. Currently, clinical data with regards to its prognosis and treatment is limited, and there is no optimal treatment method. The case presented involves a proficient mismatch repair (pMMR) and microsatellite-stable (MSS) Colorectal cancer (CRC) patient with squamous cell carcinoma (SCC) located transversely in the colon. Based on the imaging assessment, the tumor infiltration depth is classified as T4. After receiving 4 cycles of neoadjuvant treatment with oxaliplatin and capecitabine (XELOX), the patients were evaluated for partial response (PR) in 2 cycles and stable disease (SD) in 4 cycles. The patient underwent a right hemicolectomy and received postoperative paclitaxel/cisplatin (TC) adjuvant chemotherapy. After 23 months, a systemic examination revealed abdominal metastasis. A needle biopsy was conducted on the detected abdominal metastases, with the resulting pathology indicating the presence of metastatic SCC. The individual exhibited expression of programmed cell death ligand 1 (PD-L1) and a mutation in the TP53 gene. Considering the patient's disease recurrence based on medical history, a treatment plan was formulated. This involved Sintilimab plus Cetuximab and the combination of leucovorin, fluorouracil, and irinotecan (FOLFIRI) regimen. The patient received four cycles of treatment with an efficacy evaluation of SD- and seven cycles of treatment with an efficacy evaluation of SD+, which resulted in a progression-free survival (PFS) duration of 7 months. This case study presents the conventional XELOX chemotherapy protocol, which has shown limited effectiveness, and highlights the favorable results achieved by implementing the TC adjuvant chemotherapy regimen in individuals diagnosed with primary colonic SCC. Furthermore, combining immune checkpoint blockade (ICB) with other therapies for patients with advanced disease is anticipated to provide an extended duration of survival.

GBP2 is a prognostic biomarker and associated with immunotherapeutic responses in gastric cancer

BACKGROUND

The interferon-induced protein known as guanylate-binding protein 2 (GBP2) has been linked to multiple different cancer types as an oncogenic gene. Although the role of GBP2 in cancer has been preliminarily explored, it is unclear how this protein interacts with tumor immunity in gastric cancer.

METHODS

The expression, prognostic value, immune-correlations of GBP2 in gastric cancer was explored in multiple public and in-house cohorts. In addition, the pan-cancer analysis was performed to investigate the immunological role of GBP2 based on The Cancer Genome Atlas (TCGA) dataset, and the predictive value of GBP2 for immunotherapy was also examined in multiple public cohorts.

RESULTS

GBP2 was highly expressed in tumor tissues and associated with poor prognosis in gastric cancer. In addition, GBP2 was associated with the immune-hot phenotype. To be more specific, GBP2 was positively related to immuno-modulators, tumor-infiltrating immune cells (TIICs), immunotherapy biomarkers, and even well immunotherapeutic response. In addition to gastric cancer, GBP2 was expected to be an indicator of high immunogenicity in most cancer types. Importantly, GBP2 could predict the immunotherapeutic responses in at least four different cancer types, including melanoma, urothelial carcinoma, non-small cell lung cancer, and breast cancer.

CONCLUSIONS

To sum up, GBP2 expression is a promising pan-cancer biomarker for estimating the immunological characteristics of tumors and may be utilized to detect immuno-hot tumors in gastric cancer.

A prognostic signature based on seven T-cell-related cell clustering genes in bladder urothelial carcinoma

Bladder urothelial carcinoma (BLCA) is one of the most common cancer-related deaths in the world, along with high mortality. Due to the difficult detection of early symptoms, the treatment for this disease is still dissatisfactory. Thus, the current research hotspot is beginning to focus on the immune microenvironment in this disease, aiming to provide guidance for diagnosis and treatment. In this study, the single-cell RNA sequencing data downloaded from the gene expression omnibus database was used to classify the immune cells of BLCA. And the final seven T-cell-related cell clustering genes associated with BLCA prognosis (HSPA2, A2M, JUN, PDGFRB, GBP2, LGALS1, and GAS6) were screened out, and then used for constructing the prognostic model against BLCA based on the Cox and LASSO regression analysis. Satisfactorily, the model could efficiently evaluate the overall survival of BLCA and had the potential to be applied for the clinic treatment. Moreover, we also revealed that the difference in immune infiltration levels and gene mutation might account for the diverse prognosis in BLCA patients. In a word, our findings provided a novel insight for designing efficient immunotherapies for BLCA.

GBP2 promotes M1 macrophage polarization by activating the notch1 signaling pathway in diabetic nephropathy

Background

Diabetic nephropathy (DN) is one of the most common diabetic complications, which has become the primary cause of end-stage renal disease (ESRD) globally. Macrophage infiltration has been proven vital in the occurrence and development of DN. This study was designed to investigate the hub genes involved in macrophage-mediated inflammation of DN via bioinformatics analysis and experimental validation.

Methods

Gene microarray datasets were obtained from the Gene Expression Omnibus (GEO) public website. Integrating the CIBERSORT, weighted gene co-expression network analysis (WGCNA) and DEGs, we screened macrophage M1-associated key genes with the highest intramodular connectivity. Subsequently, the Least Absolute Shrinkage and Selection Operator (LASSO) regression was utilized to further mine hub genes. GSE104954 acted as an external validation to predict the expression levels and diagnostic performance of these hub genes. The Nephroseq online platform was employed to evaluate the clinical implications of these hub genes. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) were performed to elucidate the dominant biological functions and signal pathways. Finally, we conducted experiments to verify the role of GBP2 in M1 macrophage-mediated inflammatory response and the underlying mechanism of this role.

Results

Sixteen DEGs with the highest connectivity in M1 macrophages-associated module (paleturquoise module) were determined. Subsequently, we identified four hub genes through LASSO regression analysis, including CASP1, MS4A4A, CD53, and GBP2. Consistent with the training set, expression levels of these four hub genes manifested memorably elevated and the ROC curves indicated a good diagnostic accuracy with an area under the curve of greater than 0.8. Clinically, enhanced expression of these four hub genes predicted worse outcomes of DN patients. Given the known correlation between the first three hub genes and macrophage-mediated inflammation, experiments were performed to demonstrate the effect of GBP2, which proved that GBP2 contributed to M1 polarization of macrophages by activating the notch1 signaling pathway.

Conclusion

Our findings detected four hub genes, namely CASP1, MS4A4A, CD53, and GBP2, may involve in the progression of DN via pro-inflammatory M1 macrophage phenotype. GBP2 could be a promising prognostic biomarker and intervention target for DN by regulating M1 polarization.

Guanylate-binding proteins signature predicts favorable prognosis, immune-hot microenvironment, and immunotherapy response in hepatocellular carcinoma

BACKGROUND

The role of guanylate-binding proteins (GBPs) in various cancers has been elucidated recently. However, our knowledge of the clinical relevance and biological characteristics of GBPs in hepatocellular carcinoma (HCC) remains limited.

METHODS

A total of 955 HCC patients were enrolled from five independent public HCC cohorts. The role of GBP molecules in HCC was preliminarily investigated, and a GBP family signature, termed GBPs-score, was constructed by principal component analysis to combine the GBP molecule values. We revealed the effects of GBP genes and GBPs-score in HCC via well-established bioinformatics methods and validated GBP1-5 experimentally in a tissue microarray (TMA) cohort.

RESULTS

GBPs molecules were closely associated with the prognosis of patients with HCC, and a high GBPs-score highly inferred a favorable survival outcome. We also revealed high GBPs-score was related to anti-tumor immunity, the immune-hot tumor microenvironment (TME), and immunotherapy response. Among the GBPs members, GBP1-5 rather than GBP6/7 may be dominant in these fields. The TMA analysis based on immunohistochemistry showed positive correlations between GBP1-5 and the immune-hot TME with abundant infiltration of CD8+ T cells in HCC.

CONCLUSIONS

Our integrative study revealed the genetic and immunologic characterizations of GBPs in HCC and highlighted their potential values as promising biomarkers for prognosis and immunotherapy.

Deep immunophenotyping reveals clinically distinct cellular states and ecosystems in large-scale colorectal cancer

Determining the diverse cell types in the tumor microenvironment (TME) and their organization into cellular communities, is critical for understanding the biological heterogeneity and therapy of cancer. Here, we deeply immunophenotype the colorectal cancer (CRC) by integrative analysis of large-scale bulk and single cell transcriptome of 2350 patients and 53,137 cells. A rich landscape of 42 cellular states and 7 ecosystems in TMEs is uncovered and extend the previous immune classifications of CRC. Functional pathways and potential transcriptional regulators analysis of cellular states and ecosystems reveal cancer hallmark-related pathways and several critical transcription factors in CRC. High-resolution characterization of the TMEs, we discover the potential utility of cellular states (i.e., Monocytes/Macrophages and CD8 T cell) and ecosystems for prognosis and clinical therapy selection of CRC. Together, our results expand our understanding of cellular organization in TMEs of CRC, with potential implications for the development of biomarkers and precision therapies.

A five-protein prognostic signature with GBP2 functioning in immune cell infiltration of clear cell renal cell carcinoma

Clear cell renal cell carcinoma (ccRCC) is of poor clinical outcomes, and currently lacks reliable prognostic biomarkers. By analyzing the datasets of the Cancer Genome Atlas (TCGA) and the Clinical Proteomic Tumor Analysis Consortium (CPTAC), we established a five-protein prognostic signature containing GBP2, HLA-DRA, ISG15, ISG20 and ITGAX. Our data indicate that this signature was closely correlated with advanced stage, higher pathological grade, and unfavorable survivals in patients with ccRCC. We further functionally characterized GBP2. Overexpression of GBP2 enhanced the phosphorylation of STAT2 and STAT3 to trigger JAK-STAT signaling and promote cell migration and invasion in ccRCC. Treatment of Ruxolitinib, a specific inhibitor of JAK/STAT, attenuated the GBP2-mediated phenotypes. Patients with high GBP2 expression were accompanied with more infiltration of immune cells positively stained with CD3, CD8, CD68, and immune checkpoint markers PD-1 and CTLA4, which was validated by Opal multiplex immunohistochemistry in ccRCC tissues. More CD8 + T cells and CD68 + macrophages were observed in patients expressing high GBP2. Taken together, a five-protein prognostic signature was constructed in our study. GBP2 has an oncogenic role via modulating JAK-STAT signaling and tumor immune infiltration, and thus may serve as a potential therapeutic target in ccRCC.

Identification of Pyroptosis-Relevant Signature in Tumor Immune Microenvironment and Prognosis in Skin Cutaneous Melanoma Using Network Analysis

Background

Pyroptosis is closely related to the programmed death of cancer cells as well as the tumor immune microenvironment (TIME) via the host-tumor crosstalk. However, the role of pyroptosis-related genes as prognosis and TIME-related biomarkers in skin cutaneous melanoma (SKCM) patients remains unknown.

Methods

We evaluated the expression profiles, copy number variations, and somatic mutations (CNVs) of 27 genes obtained from MSigDB database regulating pyroptosis among TCGA-SKCM patients. Thereafter, we conducted single-sample gene set enrichment analysis (ssGSEA) for evaluating pyroptosis-associated expression patterns among cases and for exploring the associations with clinicopathological factors and prognostic outcome. In addition, a prognostic pyroptosis-related signature (PPRS) model was constructed by performing Cox regression, weighted gene coexpression network analysis (WGCNA), and least absolute shrinkage and selection operator (LASSO) analysis to score SKCM patients. On the other hand, we plotted the ROC and survival curves for model evaluation and verified the robustness of the model through external test sets (GSE22153, GSE54467, and GSE65904). Meanwhile, we examined the relations of clinical characteristics, oncogene mutations, biological processes (BPs), tumor stemness, immune infiltration degrees, immune checkpoints (ICs), and treatment response with PPRS via multiple methods, including immunophenoscore (IPS) analysis, gene set variation analysis (GSVA), ESTIMATE, and CIBERSORT. Finally, we constructed a nomogram incorporating PPRS and clinical characteristics to improve risk evaluation of SKCM.

Results

Many pyroptosis-regulated genes showed abnormal expression within SKCM. TP53, TP63, IL1B, IL18, IRF2, CASP5, CHMP4C, CHMP7, CASP1, and GSDME were detected with somatic mutations, among which, a majority displayed CNVs at high frequencies. Pyroptosis-associated profiles established based on pyroptosis-regulated genes showed markedly negative relation to low stage and superior prognostic outcome. Blue module was found to be highly positively correlated with pyroptosis. Later, this study established PPRS based on the expression of 8 PAGs (namely, GBP2, HPDL, FCGR2A, IFITM1, HAPLN3, CCL8, TRIM34, and GRIPAP1), which was highly associated with OS, oncogene mutations, tumor stemness, immune infiltration degrees, IC levels, treatment responses, and multiple biological processes (including cell cycle and immunoinflammatory response) in training and test set samples.

Conclusions

Based on our observations, analyzing modification patterns associated with pyroptosis among diverse cancer samples via PPRS is important, which can provide more insights into TIME infiltration features and facilitate immunotherapeutic development as well as prognosis prediction.

Identification of the molecular characteristics associated with microsatellite status of colorectal cancer patients for the clinical application of immunotherapy

Background: Mismatch repair-proficient (pMMR) microsatellite stability (MSS) in colorectal cancer (CRC) indicates an unfavorable therapeutic response to immunotherapy with immune checkpoint inhibitors (ICIs). However, the molecular characteristics of CRC patients with pMMR MSS remain largely unknown. Methods: Heterogeneities between mismatch repair-deficient (dMMR) microsatellite instability (MSI) and pMMR MSS CRC patients were investigated at the single-cell level. Next, an MSS-related risk score was constructed by single-sample gene set enrichment analysis (ssGSEA). The differences in immune and functional characteristics between the high- and low-score groups were systematically analyzed. Results: Based on the single-cell RNA (scRNA) atlas, an MSS-specific cancer cell subpopulation was identified. By taking the intersection of the significant differentially expressed genes (DEGs) between different cancer cell subtypes of the single-cell training and validation cohorts, 29 MSS-specific cancer cell marker genes were screened out for the construction of the MSS-related risk score. This risk score signature could efficiently separate pMMR MSS CRC patients into two subtypes with significantly different immune characteristics. The interactions among the different cell types were stronger in the MSS group than in the MSI group, especially for the outgoing signals of the cancer cells. In addition, functional differences between the high- and low-score groups were preliminarily investigated. Conclusion: In this study, we constructed an effective risk model to classify pMMR MSS CRC patients into two completely different groups based on the specific genes identified by single-cell analysis to identify potential CRC patients sensitive to immunotherapy and screen effective synergistic targets.

GBP2 promotes clear cell renal cell carcinoma progression through immune infiltration and regulation of PD‑L1 expression via STAT1 signaling

Guanylate‑binding protein 2 (GBP2) has been widely studied in cancer, however, its potential role in clear cell renal cell carcinoma (ccRCC) is not fully elucidated. The present study aimed to explore the effect of GBP2 on tumor progression and its possible underlying molecular mechanisms in ccRCC. The Cancer Genome Atlas, Gene Expression Omnibus, Cancer Cell Line Encyclopedia databases, and several bioinformatics analysis tools, such as Gene Expression Profiling Interactive Analysis 2, Kaplan‑Meier plotter, UALCAN, LinkedOmics, Metascape, GeneMANIA and Tumor Immune Estimation Resource, were used to characterize the functional relationship between GBP2 and ccRCC. Focusing on the association between GBP2 and programmed death ligand 1 (PD‑L1) in vitro, the regulatory mechanism was investigated by knockdown and overexpression of GBP2 in Caki‑1 and 786‑O cells using reverse transcription‑quantitative PCR, western blotting and co‑immunoprecipitation techniques. The results indicated that GBP2 was commonly upregulated in ccRCC, correlating with worse prognosis. In addition, GBP2 expression levels were positively associated with different patterns of immune cell infiltration, suggesting that the GBP2 gene regulates PD‑L1 expression via the signal transducer and activator of transcription 1 (STAT1) pathway. The present study suggested that GBP2 regulates tumor immune infiltration and promotes tumor immune escape through PD‑L1 expression, revealing a potential immunotherapeutic target for ccRCC.

Guanine nucleotide-binding protein 2, GNBP2, accelerates the progression of clear cell renal cell carcinoma via regulation of STAT3 signaling transduction pathway

BACKGROUND

Guanine nucleotide-binding protein 2 (GNBP2) is a GTPase that has critical roles in host immunity and some types of cancer, but its function in clear cell renal cell carcinoma (ccRCC) is not fully understood.

OBJECTIVE

This work explored the role of GNBP2 in ccRCC progression and the underlying molecular mechanism.

METHODS

Two public human cancer databases TNMplot and TISIDB were employed to analyze the expression pattern of GNBP2 during ccRCC progression and the correlation between GNBP2 expression and clinical features of ccRCC patients. GNBP2 functions in ccRCC cells were determined by EdU staining, flow cytometry, scratch wound assay, transwell assay, and xenograft model. Gene expression was evaluated using qPCR, Western blot, immunofluorescence staining, and immunohistochemical staining.

RESULTS

GNBP2 expression was significantly elevated in ccRCC tissues and increased gradually with the increasing tumor grades. Patients with higher GNBP2 expression had shorter overall survival times. Knockdown of GNBP2 suppressed tumor cell proliferation and cell cycle progression and reduced the capability of migration and invasion, while GNBP2 overexpression exhibited protumor effects. GNBP2 silencing by RNA interference significantly inhibited the tumor growth of tumor-bearing nude mice and decreased the proliferation marker Ki67. Mechanistically, GNBP2 downregulation suppressed the STAT3 signaling transduction, as it reduced the phosphorylation of STAT3 and modulated the expression of the target genes, including c-Myc, MMP2, N-cadherin, and E-cadherin.

CONCLUSION

These findings reveal that GNBP2 promotes ccRCC progression by regulating STAT3 signaling transduction, indicating that GNBP2 might be a promising molecular target for ccRCC therapy.

EMR1/ADGRE1 Expression in Cancer Cells Upregulated by Tumor-Associated Macrophages Is Related to Poor Prognosis in Colorectal Cancer

EMR1, a member of the adhesion G protein-coupled receptor family (ADGRE1), is a macrophage marker that is abnormally expressed in cancer cells. However, its clinical significance in colorectal cancer (CRC) is not well-known. In this investigation, EMR1 expression in tumor cells (EMR1-TC) was found in 91 (22.8%) of the 399 CRC samples tested by immunohistochemical staining and showed a significant relationship with lymph node metastasis. Furthermore, EMR1-TC was significantly associated with CD68⁺ CD163⁺ tumor-associated macrophages (TAMs), and CRC with a high combined EMR1-TC⁺CD68⁺CD163⁺ score showed worse recurrence-free survival prognosis. In an in vitro co-culture assay of colon cancer cells with myeloid cells, we found that EMR1 expression significantly upregulated in cancer cells was induced by macrophages. In addition, there was increased expression of M2 markers (CD163 and interleukin-6 & 10) in myeloid portion, while that of M1 markers (CD86 and iNOS) remained unchanged. Accordingly, upon treatment with M2 macrophage polarization inhibitors (O-ATP, trametinib, bardoxolone methyl), EMR1 expression reduced significantly, along with M2 markers (CD163 and interleukin-6 & 10). In conclusion, EMR1-TC was a high-risk factor for lymph node metastasis and correlated with poor recurrence free survival, particularly in patients with TAM-rich CRC. Furthermore, EMR1 expression in colon cancer cells may be related to M2 macrophage polarization and vice versa.

Correlation between IFNAR1 expression in peripheral blood T lymphocytes and inflammatory cytokines, tumor-infiltrating lymphocytes, and chemosensitivity in patients with colorectal cancer

IFN-α receptor (IFNAR) is critical for maintaining the crosstalk between cancer cells and lymphocytes. We investigated IFNAR1 expression in peripheral blood CD4⁺ and CD8⁺ T cells and explored their relationships with plasma cytokines, chemosensitivity and infiltrated T cells in the tumor microenvironment (TME) of colorectal cancer (CRC). The levels of IFNAR1, IFN-γ, and PD1 in peripheral T cells were tested using flow cytometry. Immunohistochemical staining of IFNAR1 in CRC tissues was performed. A cytometric bead array was used to determine the plasma concentrations of cytokines. In CRC patients, IFNAR1 levels were significantly increased in peripheral blood T cells, and plasma IL-6 levels were also significantly increased. Pearson correlation analysis revealed that IFNAR1 expression in CD8⁺ T cells was negatively associated with plasma IL-2, IFN-γ, and TNFα. IFNAR1 expression in CD4⁺ T cells was positively associated with TME infiltrated levels of CD8⁺ T cells. The levels of CD8⁺ T cells with IFNAR1 and plasma IFN-γ were associated with chemosensitivity. Collectively, IFNAR1 levels in CD4⁺ and CD8⁺ T cells were significantly upregulated in CRC patients and positively associated with T-cell infiltration. IFNAR1 may be a chemotherapy biomarker for predicting response.