Identify the Prognostic and Immune Profile of VSIR in the Tumor Microenvironment: A Pan-Cancer Analysis

Alkaline Adjuvant Regulates Proteolytic Activity of Macrophages for Antigen Cross-Presentation and Potentiates Radioimmunotherapy

Failures of radiotherapy (RT) in adaptive antitumor immunomodulation often associate with recruited tissue-repairing macrophages. Although training these macrophages to phagocytose post-RT cancer cells reverses their protumoral performance, engulfed tumor antigens are severely underrated. In fact, regulating the processing and presentation of tumor antigens, a key determinant of tumor immunogenicity, can fundamentally affect adaptive immune responses. Here it is reported that a simple Alum-like adjuvant (MgAl-based hydrotalcite, bLDH) improves radioimmunotherapy via inducing antigen cross-presentation by macrophages, independent of phenotypes. It is identified that cytidine monophosphate guanosine oligodeoxynucleotide engenders macrophages to phagocytose irradiated cancer cells. However, as semiprofessional antigen-presenting cells, macrophages possess powerful proteolytic function that is detrimental to antigen presentation. The administration of alkaline bLDH intriguingly relieves the activity of phagolysosomal proteases with acidic pH optima by preventing phagosomal acidification resulting from the vacuolar-type ATPase proton pump. The adjuvant-modulated phagolysosomes thus limit antigen degradation and enhance tumor antigen cross-presentation over tenfold. To examine from an in vivo breast tumor model, trained macrophages successfully cross-prime antigen-specific CD8+ T cells and curb RT-associated metastasis. The findings propose to pay close attention to the effect of adjuvants on precision immunotherapy and highlight the positive contribution of cross-presenting macrophages in radioimmunotherapy.

METTL3-VISTA axis-based combination immunotherapy for APC truncation colorectal cancer

OBJECTIVE

Although immune checkpoint blockade (ICB) therapy represents a bright spot in antitumor immunotherapy, its clinical benefits in colorectal cancer (CRC) are limited. Therefore, a new target for mediating CRC immunosuppression is urgently needed. Adenomatous polyposis coli (APC) mutations have been reported as early-stage characteristic events in CRC, but the role of truncated APC in the CRC immune microenvironment remains unclear and its clinical significance has yet to be explored.

DESIGN

Adenocarcinoma formation in the colon of the APCMin/+ mouse model, which displays features associated with the translation of truncated APC proteins, was induced by azoxymethane/dextran sodium sulfate. Multiplexed immunohistochemical consecutive staining on single slides and flow cytometry were used to explore the activation of immune cells and the expression of the immune checkpoint V-domain immunoglobulin suppressor of T-cell activation (VISTA) in the CRC tissues of APCWT and APCMin/+ mice. The construction of truncated APC vectors and an initial subserosal graft tumor mouse model was employed to mimic the tumor microenvironment (TME) during APC mutation. Methylated RNA immunoprecipitation-quantitative PCR assays were performed to investigate the N6-methyladenosine (m6A)-dependent transcriptional regulation of hypoxia-inducible factor-1 alpha (HIF1α) by methyltransferase-like protein 3 (METTL3). Mettl3fl/fl vil1-cre+/- mice were used to demonstrate that targeting METTL3 is a mediator that mitigates the deleterious effects of the APC978∆-HIF1α axis on antitumor immunity. A chimeric VISTA humanized mouse model was used to evaluate the drug efficacy of the VISTA-targeted compound onvatilimab.

RESULTS

We showed that APC978∆, a truncated APC protein, mediated overexpression of METTL3, resulting in m6A methylation of HIF1α messenger RNA and high expression of HIF1α. Furthermore, HIF1α promotes the migration of myeloid-derived suppressor cells to the TME by binding to the promoters of MCP-1 and MIF. In addition, HIF1α enhances the expression of the immune checkpoint VISTA on CRC cells, weakening tumor immune monitoring.

CONCLUSIONS

We elucidate that an underappreciated function of truncated APC in CRC is its ability to drive an immunosuppressive program that boosts tumor progression. Our work could provide a new perspective for the clinical application of immunotherapy in patients with CRC resistant to ICB therapy.

Catching the Big Fish in Big Data: A Meta-Analysis of Zebrafish Kidney scRNA-Seq Datasets Highlights Conserved Molecular Profiles of Macrophages and Neutrophils in Vertebrates

The innate immune system (IIS) is an ancient and essential defense mechanism that protects animals against a wide range of pathogens and diseases. Although extensively studied in mammals, our understanding of the IIS in other taxa remains limited. The zebrafish (Danio rerio) serves as a promising model organism for investigating IIS-related processes, yet the immunogenetics of fish are not fully elucidated. To address this gap, we conducted a meta-analysis of single-cell RNA sequencing (scRNA-seq) datasets from zebrafish kidney marrow, encompassing approximately 250,000 immune cells. Our analysis confirms the presence of key genetic pathways in zebrafish innate immune cells that are similar to those identified in mammals. Zebrafish macrophages specifically express genes encoding cathepsins, major histocompatibility complex class II proteins, integral membrane proteins, and the V-ATPase complex and demonstrate the enrichment of oxidative phosphorylation ferroptosis processes. Neutrophils are characterized by the significant expression of genes encoding actins, cytoskeleton organizing proteins, the Arp2/3 complex, and glycolysis enzymes and have demonstrated their involvement in GnRH and CLR signaling pathways, adherents, and tight junctions. Both macrophages and neutrophils highly express genes of NOD-like receptors, phagosomes, and lysosome pathways and genes involved in apoptosis. Our findings reinforce the idea about the existence of a wide spectrum of immune cell phenotypes in fish since we found only a small number of cells with clear pro- or anti-inflammatory signatures.

Aberrant expression of B7-H4 and B7-H5 contributes to the development of cutaneous squamous cell carcinoma

Cutaneous squamous cell carcinoma (CSCC) is the second most common malignant tumor of the skin. B7 homolog 4 (B7-H4) and B7-H5 (B7 homolog 5) are associated with a variety of tumors. Investigate the potential role of B7-H4 and B7-H5 in regulating the tumorigenesis and progression of CSCC. B7-H4 and B7-H5 transcriptome data were collected from GEO and TCGA databases and subjected to bioinformatical analysis by protein-protein interaction (PPI) network, functional enrichment analysis, immune analysis, and drug-gene interaction prediction analysis. We characterized the expression of B7-H4 and B7-H5 in carcinoma tissues of CSCC patients by immunohistochemistry. Meanwhile, the clinical correlation of B7-H4 and B7-H5 in CSCC was explored by statistical analysis. B7-H4 and B7-H5 genes were under-expressed in CSCC and correlated with tumor staging. According to GO and KEGG Pathway enrichment analysis, B7-H4, and B7-H5 can regulate the proliferation and activation of T cells, lymphocytes, and monocytes, and the expression of cytokines, such as IL-6 and IL-10, in CSCC. B7-H4 and B7-H5 are also jointly involved in the occurrence and development of CSCC via the JAK-STAT and Notch signaling pathways. We found that B7-H4 and B7-H5 proteins were abnormally highly expressed in CSCC tissue and correlated with tumor size and stage. Our findings offer new insights into the pathogenesis of CSCC and suggest that B7-H4 and B7-H5 are novel tissue biomarkers and promising therapeutic targets for CSCC.

The role of ARL4C in predicting prognosis and immunotherapy drug susceptibility in pan-cancer analysis

Background: ARLs, which are a class of small GTP-binding proteins, play a crucial role in facilitating tumor tumorigenesis and development. ARL4C, a vital member of the ARLs family, has been implicated in the progression of tumors, metastatic dissemination, and development of resistance to therapeutic drugs. Nevertheless, the precise functional mechanisms of ARL4C concerning tumor prognosis and immunotherapy drug susceptibility remain elusive. Methods: By combining the GTEx and TCGA databases, the presence of ARL4C was examined in 33 various types of cancer. Immunohistochemistry and immunofluorescence staining techniques were utilized to confirm the expression of ARL4C in particular tumor tissues. Furthermore, the ESTIMATE algorithm and TIMER2.0 database were utilized to analyze the tumor microenvironment and immune infiltration associated with ARL4C. The TISCH platform facilitated the utilization of single-cell RNA-seq datasets for further analysis. ARL4C-related immune escape was investigated using the TISMO tool. Lastly, drug sensitivity analysis was conducted to assess the sensitivity of different types of tumors to compounds based on the varying levels of ARL4C expression. Results: The study found that ARL4C was highly expressed in 23 different types of cancer. Moreover, the presence of high ARL4C expression was found to be associated with a poor prognosis in BLCA, COAD, KIRP, LGG, and UCEC. Notably, ARL4C was also expressed in immune cells, and its high expression was found to be correlated with cancer immune activation. Most importantly, the drug sensitivity analysis revealed a positive correlation between ARL4C expression and the heightened sensitivity of tumors to Staurosporine, Midostaurin, and Nelarabine. Conclusion: The findings from our study indicate that the expression level of ARL4C may exert an influence on cancer development, prognosis, and susceptibility to immunotherapy drugs. In addition, the involvement of ARL4C in the tumor immune microenvironment has expanded the concept of ARL4C-targeted immunotherapy.

Immune checkpoints represent a promising breakthrough in targeted therapy and prognosis of myelodysplastic syndrome

Myelodysplastic syndrome (MDS) is a hematological malignancy of undetermined etiology, possibly linked to chromosomal structural alterations, genetic mutations, presentation and carcinogenicity of variant antigens on cell surface, and the generation of pro-inflammatory microenvironment in the bone marrow. Current drugs are unable to cure this disease, and therefore, decreasing the survival and proliferation of malignant cells to delay disease progression and extend the survival time of patients becomes the primary approach to management. In recent years, the immune system has received increasing attention for its potential role in the occurrence and development of MDS, leading to the emergence of immunoregulation as a viable treatment option. The current review provides a brief overview of pathogenesis of MDS and current treatment principles. In the meantime, the significance of immune proteins in treatment and prognosis of MDS is also discussed.

An Immune-Related Gene Signature for Predicting Survival and Immunotherapy Efficacy in Esophageal Adenocarcinoma

BACKGROUND Immune checkpoint inhibitor (ICI) therapy has attracted wide attention in the treatment of malignant tumors. This study was designed to build a prognostic model based on immune-related genes for esophageal adenocarcinoma (EAC). MATERIAL AND METHODS The expression of immune-related differentially-expressed genes (IRDEGs) between EAC and normal samples from The Cancer Genome Atlas database was analyzed. Univariate and multivariate Cox regressions were used to identify the prognostic IRDEGs and construct an immune-related gene signature (IRGS) to predict the overall survival (OS) of EAC patients. Then, the molecular mechanisms and immune characteristics were comprehensively analyzed. RESULTS A total of 111 IRDEGs were obtained from the weighted gene co-expression network analysis. Univariate Cox regression analysis showed that 12 IRDEGs (P<0.05 for all) were linked with OS in the EAC patients. Four genes were used to construct the IRGS based on the multivariate Cox regression analysis. Patients in the high-risk group showed worse OS than those in the low-risk group (P<0.001). A high-risk score was related to DNA replication relevant pathways, an increase in mutation rate, and an increase in activated mast cell infiltration. Patients with high-risk scores had lower tumor immune dysfunction and exclusion scores (P<0.001). CONCLUSIONS IRDEGs may be involved in the progression of EAC. The high-risk group is more suitable for immunotherapy, which may provide a reference value for the treatment of clinical EAC patients. Therefore, it is possible to identify the patients who are better suited for ICI therapy.

Identification of CD73 as a Novel Biomarker Encompassing the Tumor Microenvironment, Prognosis, and Therapeutic Responses in Various Cancers

CD73 is essential in promoting tumor growth by prohibiting anti-tumor immunity in many cancer types. While the mechanism remains largely unknown, our paper comprehensively confirmed the onco-immunological characteristics of CD73 in the tumor microenvironment (TME) of pan-cancer. This paper explored the expression pattern, mutational profile, prognostic value, tumor immune infiltration, and response to immunotherapy of CD73 in a continuous cohort of cancers through various computational tools. The co-expression of CD73 on cancer cells, immune cells, and stromal cells in the TME was also detected. Especially, we examined the correlation between CD73 and CD8+ (a marker of T cell), CD68+ (a marker of macrophage), and CD163+ (a marker of M2 macrophage) cells using multiplex immunofluorescence staining of tissue microarrays. CD73 expression is significantly associated with a patient's prognosis and could be a promising predictor of these cancers. High CD73 levels are strongly linked to immune infiltrations, neoantigens, and immune checkpoint expression in the TME. In particular, enrichment signaling pathway analysis demonstrated that CD73 was obviously related to activation pathways of immune cells, including T cells, macrophages, and cancer-associated fibroblasts (CAFs). Meanwhile, single-cell sequencing algorithms found that CD73 is predominantly co-expressed on cancer cells, CAFs, M2 macrophages, and T cells in several cancers. In addition, we explored the cellular communication among 14 cell types in glioblastoma (GBM) based on CD73 expression. Based on the expression of CD73 as well as macrophage and T cell markers, we predicted the methylation and enrichment pathways of these markers in pan-cancer. Furthermore, a lot of therapeutic molecules sensitive to these markers were predicted. Finally, potential anticancer inhibitors, immunotherapies, and gene therapy responses targeting CD73 were identified from a series of immunotherapy cohorts. CD73 is closely linked to clinical prognosis and immune infiltration in many cancers. Targeting CD73-dependent signaling pathways may be a promising therapeutic strategy for future tumor immunotherapy.

Pan-Cancer Pyroptosis Analyses Identified Novel Immunology and Chemotherapy-Related Prognostic Signatures in Cancer Subtypes

Despite mounting evidence linking pyroptotic cell death to tumor growth, the clinical significance and disease mechanism of pyroptosis in cancer remain uncertain. In this study, we established a unique gene signature (π signature) that can be used as a predictive and prognostic tool in pyroptosis-related cancer subtypes. We found that the 13 core pyroptosis genes exerted opposite prognostic effects in different cancer types, which were subgrouped as pyroptosis positively related cancer and pyroptosis negatively related cancer. Subsequently, π signature was identified separately from the hub genes in pyroptosis positively related cancer and pyroptosis negatively related cancer subtypes. It was shown that π signature was well correlated with patient survival, pathological stages, tumor lymphocyte infiltration, and immunotherapy response. π signature was also applied as a predictive tool for chemotherapy drug responses and used as an independent factor for patient overall survival prediction. In short, this elaborated genetic signature could help us understand the oncogenic mechanism and pave the way for further therapeutic strategies based on pyroptosis.