B7H3 regulates differentiation and serves as a potential biomarker and theranostic target for human glioblastoma

Recent advances and impending challenges for the radiopharmaceutical sciences in oncology

This paper is the first of a Series on theranostics that summarises the current landscape of the radiopharmaceutical sciences as they pertain to oncology. In this Series paper, we describe exciting developments in radiochemistry and the production of radionuclides, the development and translation of theranostics, and the application of artificial intelligence to our field. These developments are catalysing growth in the use of radiopharmaceuticals to the benefit of patients worldwide. We also highlight some of the key issues to be addressed in the coming years to realise the full potential of radiopharmaceuticals to treat cancer.

Pan-Cancer Interrogation of B7-H3 (CD276) as an Actionable Therapeutic Target Across Human Malignancies

B7-H3 (CD276) is a transmembrane glycoprotein of the B7 immune checkpoint superfamily that has emerged as a promising therapeutic target. To better understand the applicability of B7-H3-directed therapies, we analyzed 156,791 samples comprising 50 cancer types to interrogate the clinical, genomic, transcriptomic, and immunologic correlates of B7-H3 mRNA expression. DNA (592-gene/whole-exome) and RNA (whole-transcriptome) sequencing was performed from samples submitted to Caris Life Sciences. B7-H3 high versus low expression was based on top and bottom quartiles for each cancer type. Patients' overall survival was determined from insurance claims data. Pathway analysis was performed using gene set enrichment analyses. Immune cell fractions were inferred using quanTIseq. B7-H3 is expressed across several human malignancies including prostate, pancreatic, ovarian, and lung cancers. High B7-H3 expression is associated with differences in overall survival, possibly indicating a prognostic role of B7-H3 for some cancers. When examining molecular features across all cancer types, we did not identify recurrent associations between B7-H3 expression and genetic alterations in TP53, RB1, and KRAS. However, we find consistent enrichment of epithelial-to-mesenchymal transition, Wnt, TGFβ, and Notch signaling pathways. In addition, tumors with high B7-H3 expression are associated with greater proportions of M1 macrophages, but lower fractions of CD8+ T cells. We have begun to define the genomic, transcriptomic, clinical, and immunologic features associated with B7-H3 expression in 50 cancer types. We report novel clinical and molecular features of B7-H3-high tumors which may inform how current B7-H3 therapeutics should be deployed and prioritized.

SIGNIFICANCE

B7-H3-targeting therapeutics have shown promising results in initial clinical trials. In this pan-cancer analysis of B7-H3 mRNA expression, we found that B7-H3 exhibits robust expression in many common cancer types. These results may inform further development of B7-H3-targeting therapeutics and may guide clinical decisions for patients with limited treatment options.

IDH mutation, glioma immunogenicity, and therapeutic challenge of primary mismatch repair deficient IDH-mutant astrocytoma PMMRDIA: a systematic review

In 2021, Suwala et al. described Primary Mismatch Repair Deficient IDH-mutant Astrocytoma (PMMRDIA) as a distinct group of gliomas. In unsupervised clustering, PMMRDIA forms distinct cluster, separate from other IDH-mutant gliomas, including IDH-mutant gliomas with secondary mismatch repair (MMR) deficiency. In the published cohort, three patients received treatment with an immune checkpoint blocker (ICB), yet none exhibited a response, which aligns with existing knowledge about the decreased immunogenicity of IDH-mutant gliomas in comparison to IDH-wildtype. In the case of PMMRDIA, the inherent resistance to the standard-of-care temozolomide caused by MMR deficiency is an additional challenge. It is known that a gain-of-function mutation of IDH1/2 genes produces the oncometabolite R-2-hydroxyglutarate (R-2-HG), which increases DNA and histone methylation contributing to the characteristic glioma-associated CpG island methylator phenotype (G-CIMP). While other factors could be involved in remodeling the tumor microenvironment (TME) of IDH-mutant gliomas, this systematic review emphasizes the role of R-2-HG and the subsequent G-CIMP in immune suppression. This highlights a potential actionable pathway to enhance the response of ICB, which might be relevant for addressing the unmet therapeutic challenge of PMMRDIA.

Spatial Distribution of Immune Cells in Primary and Recurrent Glioblastoma: A Small Case Study

Only a minority of patients with glioblastoma (GBM) respond to immunotherapy, and always only partially. There is a lack of knowledge on immune distribution in GBM and in its tumor microenvironment (TME). To address the question, we used paired primary and recurrent tumors from GBM patients to study the composition and the evolution of the immune landscape upon treatment. We studied the expression of a handful of immune markers (CD3, CD8, CD68, PD-L1 and PD-1) in GBM tissues in 15 paired primary and recurrent GBM. In five selected patients, we used Nanostring Digital Spatial Profiling (DSP) to obtain simultaneous assessments of multiple biomarkers both within the tumor and the microenvironment in paired primary and recurrent GBM. Our results suggest that the evolution of the immune landscape between paired primary and recurrent GBM tumors is highly heterogeneous. However, our study identifies B3-H7 and HLA-DR as potential targets in primary and recurrent GBM. Spatial profiling of immune markers from matched primary and recurrent GBM shows a nonlinear complex evolution during the progression of cancer. Nonetheless, our study demonstrated a global increase in macrophages, and revealed differential localization of some markers, such as B7-H3 and HLA-DR, between GBM and its TME.

A clinicopathological analysis of supratentorial ependymoma, ZFTA fusion-positive: utility of immunohistochemical detection of CDKN2A alterations and characteristics of the immune microenvironment

EPN-ZFTA is a rare brain tumor where prognostic factors remain unclear and no effective immunotherapy or chemotherapy is currently available. Therefore, this study investigated its clinicopathological features, evaluated the utility of MTAP and p16 IHC as surrogate markers of CDKN2A alterations, and characterized the immune microenvironment of EPN-ZFTA. Thirty surgically removed brain tumors, including 10 EPN-ZFTA, were subjected to IHC. MLPA was performed for CDKN2A HD in 20 ependymal tumors, including EPN-ZFTA. The 5-years OS and PFS of EPN-ZFTA were 90% and 60%, respectively. CDKN2A HD was detected in two cases of EPN-ZFTA; these cases were immunohistochemically negative for both MTAP and p16 and recurred earlier after surgery. As for the immune microenvironment of EPN-ZFTA, B7-H3, but not PD-L1, was positive in all cases of EPN-ZFTA; Iba-1-positive or CD204-positive macrophages were large, while infiltrating lymphocytes were small, in number in EPN-ZFTA. Collectively, these results indicate the potential of MTAP and p16 IHC as useful surrogate markers of CDKN2A HD in EPN-ZFTA, and tumor-associated macrophages, including the M2 type, may contribute to its immune microenvironment. Furthermore, the expression of B7-H3 in EPN-ZFTA may indicate the usefulness of B7-H3 as a target of immune checkpoint chemotherapy for EPN-ZFTA via B7-H3 pathway.

B7H3 Role in Reshaping Immunosuppressive Landscape in MSI and MSS Colorectal Cancer Tumours

The study aimed to assess the expression of B7H3 concerning clinicopathological and histological parameters, including MSI/MSS status, CD-8 cells, tumour-infiltrating lymphocytes (TILs), budding, TNM scale and grading. Moreover, we analyzed the B7H3-related pathways using available online datasets and the immunological context of B7H3 expression, through the 48-cytokine screening panel of cancer tissues homogenates, immunogenic features and immune composition. The study included 158 patients diagnosed with CRC. To assess B7H3 levels, we performed an immunohistochemistry method (IHC) and enzyme-linked immunosorbent assay (ELISA). To elucidate the immune composition of colorectal cancer, we performed the Bio-Plex Pro Human 48-cytokine panel. To study biological characteristics of B7H3, we used online databases. Expression of B7H3 was upregulated in CRC tumour tissues in comparison to adjacent noncancerous margin tissues. The concentrations of B7H3 in tumours were positively associated with T parameter of patients and negatively with tumour-infiltrating lymphocytes score. Additionally, Principal Component Analysis showed that B7H3 expression in tumours correlated positively with cytokines associated with M2-macrophages and protumour growth factors. The expression of B7H3 in tumours was independent of MSI/MSS status. These findings will improve our understanding of B7H3 role in colorectal cancer immunity. Our study suggests that B7-H3 is a promising potential target for cancer therapy. Further studies must clarify the mechanisms of B7H3 overexpression and its therapeutic importance in colorectal cancer.

B7-H3 chimeric antigen receptor-modified T cell shows potential for targeted treatment of acute myeloid leukaemia

BACKGROUND AND AIMS

Chimeric antigen receptor (CAR)-T cell therapy is a novel type of immunotherapy. However, the use of CAR-T cells to treat acute myeloid leukaemia (AML) has limitations. B7-H3 is expressed in several malignancies, including some types of AML cells. However, its expression in normal tissues is low. Therefore, B7-H3 is ideal for targeted AML therapy.

MATERIALS AND METHODS

First, we constructed B7-H3 CAR that can target B7-H3, and then constructed B7-H3-CAR-T cells in vitro, which were co-incubated with six AML cell lines expressing different levels of B7-H3, respectively. The toxicity and cytokines were detected by flow cytometry. In vivo, AML model was established in B-NSG mice to study the toxicity of B7-H3-CAR T on AML cells.

RESULTS

In vitro functional tests showed that B7-H3-CAR-T cells were cytotoxic to B7-H3-positive AML tumor cells and had good scavenging effect on B7-H3-expressing AML cell lines, and the cytokine results were consistent. In vivo, B7-H3-CAR-T cells significantly inhibited tumor cell growth in a mouse model of AML, prolonging mouse survival compared with controls.

CONCLUSION

B7-H3-CAR-T cells may serve as a novel therapeutic method for the targeted treatment of AML.

Identification, validation and biological characterisation of novel glioblastoma tumour microenvironment subtypes: implications for precision immunotherapy

BACKGROUND

New precision medicine therapies are urgently required for glioblastoma (GBM). However, to date, efforts to subtype patients based on molecular profiles have failed to direct treatment strategies. We hypothesised that interrogation of the GBM tumour microenvironment (TME) and identification of novel TME-specific subtypes could inform new precision immunotherapy treatment strategies.

MATERIALS AND METHODS

A refined and validated microenvironment cell population (MCP) counter method was applied to >800 GBM patient tumours (GBM-MCP-counter). Specifically, partition around medoids (PAM) clustering of GBM-MCP-counter scores in the GLIOTRAIN discovery cohort identified three novel patient clusters, uniquely characterised by TME composition, functional orientation markers and immune checkpoint proteins. Validation was carried out in three independent GBM-RNA-seq datasets. Neoantigen, mutational and gene ontology analysis identified mutations and uniquely altered pathways across subtypes. The longitudinal Glioma Longitudinal AnalySiS (GLASS) cohort and three immunotherapy clinical trial cohorts [treatment with neoadjuvant/adjuvant anti-programmed cell death protein 1 (PD-1) or PSVRIPO] were further interrogated to assess subtype alterations between primary and recurrent tumours and to assess the utility of TME classifiers as immunotherapy biomarkers.

RESULTS

TME^High tumours (30%) displayed elevated lymphocyte, myeloid cell immune checkpoint, programmed cell death protein 1 (PD-1) and cytotoxic T-lymphocyte-associated protein 4 transcripts. TME^High/mesenchymal+ patients featured tertiary lymphoid structures. TME^Med (46%) tumours were enriched for endothelial cell gene expression profiles and displayed heterogeneous immune populations. TME^Low (24%) tumours were manifest as an 'immune-desert' group. TME subtype transitions upon recurrence were identified in the longitudinal GLASS cohort. Assessment of GBM immunotherapy trial datasets revealed that TME^High patients receiving neoadjuvant anti-PD-1 had significantly increased overall survival (P = 0.04). Moreover, TME^High patients treated with adjuvant anti-PD-1 or oncolytic virus (PVSRIPO) showed a trend towards improved survival.

CONCLUSIONS

We have established a novel TME-based classification system for application in intracranial malignancies. TME subtypes represent canonical 'termini a quo' (starting points) to support an improved precision immunotherapy treatment approach.

Variable Intrinsic Expression of Immunoregulatory Biomarkers in Breast Cancer Cell Lines, Mammospheres, and Co-Cultures

Advances in immunotherapy have increased interest in knowing the role of the immune system in breast cancer (BC) pathogenesis. Therefore, immune checkpoints (IC) and other pathways related to immune regulation, such as JAK2 and FoXO1, have emerged as potential targets for BC treatment. However, their intrinsic gene expression in vitro has not been extensively studied in this neoplasia. Thus, we evaluated the mRNA expression of tumor-cell-intrinsic CTLA-4, PDCD1 (PD1), CD274 (PD-L1), PDCD1LG2 (PD-L2), CD276 (B7-H3), JAK2, and FoXO1 in different BC cell lines, derived mammospheres, and co-cultures with peripheral blood mononuclear cells (PBMCs) by real-time quantitative polymerase chain reaction (qRT-PCR). Our results showed that intrinsic CTLA-4, CD274 (PD-L1), and PDCD1LG2 (PD-L2) were highly expressed in triple-negative cell lines, while CD276 was predominantly overexpressed in luminal cell lines. In contrast, JAK2 and FoXO1 were under-expressed. Moreover, high levels of CTLA-4, PDCD1 (PD1), CD274 (PD-L1), PDCD1LG2 (PD-L2), and JAK2 were found after mammosphere formation. Finally, the interaction between BC cell lines and peripheral blood mononuclear cells (PBMCs) stimulates the intrinsic expression of CTLA-4, PCDC1 (PD1), CD274 (PD-L1), and PDCD1LG2 (PD-L2). In conclusion, the intrinsic expression of immunoregulatory genes seems very dynamic, depending on BC phenotype, culture conditions, and tumor-immune cell interactions.

Circular RNA circFARSA promotes the tumorigenesis of non-small cell lung cancer by elevating B7H3 via sponging miR-15a-5p

Non-small cell lung cancer (NSCLC) is currently one of the malignant tumors with the highest incidence and mortality rate in China. Circular RNA hsa_circ_0000896 (circFARSA) has been reported as being an oncogene and a potential biomarker for NSCL. However, the functional role and action mechanism of circFARSA in NSCLC progression have not been fully elucidated. The present study demonstrated that circFRASA was upregulated in NSCLC tissues and cell lines, and its expression was positively correlated with poor prognosis of patients with NSCLC. Further experiments revealed that circFARSA knockdown inhibited cell proliferation, migration, and invasion in vitro experiments, but overexpression of circFARSA exhibited opposite results. Mechanistically, circFARSA facilitated the malignant phenotype of NSCLC cells by enhancing B7H3 expression through sponging miR-15a-5p. In vivo experiments, knockdown of circFARSA restricted tumor growth and metastasis. In conclusion, circFARSA served as a sponge of miR-15a-5p to promote tumorigenesis and development of NSCLC by upregulation of B7H3 expression, which provided evidence of circFARSA maybe act as a novel therapeutic target for NSCLC.

Remarkable immune and clinical value of novel ferroptosis-related genes in glioma

Ferroptosis is a neoteric model of regulated cell death that shows great potential for the understanding of tumor immunology and as a target for therapy. The present study aimed to identify ferroptosis-related differentially expressed genes (DEGs) in glioma and to explore their value through systematic analysis. Ferroptosis-related DEGs were identified through the Gene Expression Omnibus database in combination with the FerrDb database and analyzed in the Genotype-Tissue Expression database and The Cancer Genome Atlas database. Possible signaling pathways involved were explored by construction of enrichment analysis and protein–protein interaction of these DEGs. Potential regulation of the immune microenvironment, immune checkpoint and chemokine was postulated by immune analysis. A prognosis model for glioma was developed using survival analysis, exhibited by the nomogram and evaluated by the calibration curve. The prognostic value of the model was validated by using an independent cohort. A total of 15 ferroptosis-related DEGs were identified, including 7 down-regulated and 8 up-regulated, with ATP6V1G2, GABARAPL1 and GOT1 as hub genes. The expression of all 3 hub genes was positively correlated with T follicular helper cells and natural killer CD56bright cells. These hub genes were negatively correlated with the macrophage cell type as well as B7H3, PDCD1, LAG3 and CXCL16, CXCR4, CCR5. Low expression of all 3 hub genes was associated with poor prognosis in glioma cases. ATP6V1G2 might be an independent prognostic factor and, as such, a high-precision prognostic model of glioma was constructed. We identified novel ferroptosis-related genes with clinical value in glioma and revealed their possible tumor immune relevance. Furthermore, in glioma, we pinpointed underlying critical elements of the chemokine, immune microenvironment and immune checkpoint, and were able to develop a predictive model of prognosis.

An Open-Source AI Framework for the Analysis of Single Cells in Whole-Slide Images with a Note on CD276 in Glioblastoma

Routine examination of entire histological slides at cellular resolution poses a significant if not insurmountable challenge to human observers. However, high-resolution data such as the cellular distribution of proteins in tissues, e.g., those obtained following immunochemical staining, are highly desirable. Our present study extends the applicability of the PathoFusion framework to the cellular level. We illustrate our approach using the detection of CD276 immunoreactive cells in glioblastoma as an example. Following automatic identification by means of PathoFusion's bifocal convolutional neural network (BCNN) model, individual cells are automatically profiled and counted. Only discriminable cells selected through data filtering and thresholding were segmented for cell-level analysis. Subsequently, we converted the detection signals into the corresponding heatmaps visualizing the distribution of the detected cells in entire whole-slide images of adjacent H&E-stained sections using the Discrete Wavelet Transform (DWT). Our results demonstrate that PathoFusion is capable of autonomously detecting and counting individual immunochemically labelled cells with a high prediction performance of 0.992 AUC and 97.7% accuracy. The data can be used for whole-slide cross-modality analyses, e.g., relationships between immunochemical signals and anaplastic histological features. PathoFusion has the potential to be applied to additional problems that seek to correlate heterogeneous data streams and to serve as a clinically applicable, weakly supervised system for histological image analyses in (neuro)pathology.

The immune checkpoint B7-H3 (CD276) regulates adipocyte progenitor metabolism and obesity development

The immune checkpoint B7-H3 (CD276) is a member of the B7 family that has been studied in the tumor microenvironment and immunotherapy, but its potential role in metabolism remains largely unknown. Here, we show that B7-H3 is highly expressed in mouse and human adipose tissue at steady state, with the highest levels in adipocyte progenitor cells. B7-H3 is rapidly down-regulated upon the initiation of adipocyte differentiation. Combined RNA sequencing and metabolic studies reveal that B7-H3 stimulates glycolytic and mitochondrial activity of adipocyte progenitors. Loss of B7-H3 in progenitors results in impaired oxidative metabolism program and increased lipid accumulation in derived adipocytes. Consistent with these observations, mice knocked out for B7-H3 develop spontaneous obesity, metabolic dysfunction, and adipose tissue inflammation. Our results reveal an unexpected metabolic role for B7-H3 in adipose tissue and open potential new avenues for the treatment of metabolic diseases by targeting the B7-H3 pathway.

Canine Melanoma Immunology and Immunotherapy: Relevance of Translational Research

In veterinary oncology, canine melanoma is still a fatal disease for which innovative and long-lasting curative treatments are urgently required. Considering the similarities between canine and human melanoma and the clinical revolution that immunotherapy has instigated in the treatment of human melanoma patients, special attention must be paid to advancements in tumor immunology research in the veterinary field. Herein, we aim to discuss the most relevant knowledge on the immune landscape of canine melanoma and the most promising immunotherapeutic approaches under investigation. Particular attention will be dedicated to anti-cancer vaccination, and, especially, to the encouraging clinical results that we have obtained with DNA vaccines directed against chondroitin sulfate proteoglycan 4 (CSPG4), which is an appealing tumor-associated antigen with a key oncogenic role in both canine and human melanoma. In parallel with advances in therapeutic options, progress in the identification of easily accessible biomarkers to improve the diagnosis and the prognosis of melanoma should be sought, with circulating small extracellular vesicles emerging as strategically relevant players. Translational advances in melanoma management, whether achieved in the human or veterinary fields, may drive improvements with mutual clinical benefits for both human and canine patients; this is where the strength of comparative oncology lies.

Glioma targeted therapy: insight into future of molecular approaches

Gliomas are the common type of brain tumors originating from glial cells. Epidemiologically, gliomas occur among all ages, more often seen in adults, which males are more susceptible than females. According to the fifth edition of the WHO Classification of Tumors of the Central Nervous System (WHO CNS5), standard of care and prognosis of gliomas can be dramatically different. Generally, circumscribed gliomas are usually benign and recommended to early complete resection, with chemotherapy if necessary. Diffuse gliomas and other high-grade gliomas according to their molecule subtype are slightly intractable, with necessity of chemotherapy. However, for glioblastoma, feasible resection followed by radiotherapy plus temozolomide chemotherapy define the current standard of care. Here, we discuss novel feasible or potential targets for treatment of gliomas, especially IDH-wild type glioblastoma. Classic targets such as the p53 and retinoblastoma (RB) pathway and epidermal growth factor receptor (EGFR) gene alteration have met failure due to complex regulatory network. There is ever-increasing interest in immunotherapy (immune checkpoint molecule, tumor associated macrophage, dendritic cell vaccine, CAR-T), tumor microenvironment, and combination of several efficacious methods. With many targeted therapy options emerging, biomarkers guiding the prescription of a particular targeted therapy are also attractive. More pre-clinical and clinical trials are urgently needed to explore and evaluate the feasibility of targeted therapy with the corresponding biomarkers for effective personalized treatment options.

The role of B7-H3 in tumors and its potential in clinical application

B7-H3 (CD276 molecule) is an immune checkpoint from the B7 family of molecules that acts more as a co-inhibitory molecule to promote tumor progression. It is abnormally expressed on tumor cells and can be induced to express on antigen-presenting cells (APCs) including dendritic cells (DCs) and macrophages. In the tumor microenvironment (TME), B7-H3 promotes tumor progression by impairing T cell response, promoting the polarization of tumor-associated macrophages (TAMs) to M2, inhibiting the function of DCs, and promoting the migration and invasion of cancer-associated fibroblasts (CAFs). In addition, through non-immunological functions, B7-H3 promotes tumor cell proliferation, invasion, metastasis, resistance, angiogenesis, and metabolism, or in the form of exosomes to promote tumor progression. In this process, microRNAs can regulate the expression of B7-H3. B7-H3 may serve as a potential biomarker for tumor diagnosis and a marker of poor prognosis. Immunotherapy targeting B7-H3 and the combination of B7-H3 and other immune checkpoints have shown certain efficacy. In this review, we summarized the basic characteristics of B7-H3 and its mechanism to promote tumor progression by inducing immunosuppression and non-immunological functions, as well as the potential clinical applications of B7-H3 and immunotherapy based on B7-H3.

Challenges and Prospects for Designer T and NK Cells in Glioblastoma Immunotherapy

Glioblastoma (GBM) is the most prevalent, aggressive primary brain tumour with a dismal prognosis. Treatment at diagnosis has limited efficacy and there is no standardised treatment at recurrence. New, personalised treatment options are under investigation, although challenges persist for heterogenous tumours such as GBM. Gene editing technologies are a game changer, enabling design of novel molecular-immunological treatments to be used in combination with chemoradiation, to achieve long lasting survival benefits for patients. Here, we review the literature on how cutting-edge molecular gene editing technologies can be applied to known and emerging tumour-associated antigens to enhance chimeric antigen receptor T and NK cell therapies for GBM. A tight balance of limiting neurotoxicity, avoiding tumour antigen loss and therapy resistance, while simultaneously promoting long-term persistence of the adoptively transferred cells must be maintained to significantly improve patient survival. We discuss the opportunities and challenges posed by the brain contexture to the administration of the treatments and achieving sustained clinical responses.

Gene clusters based on OLIG2 and CD276 could distinguish molecular profiling in glioblastoma

Background

The molecular profiling of glioblastoma (GBM) based on transcriptomic analysis could provide precise treatment and prognosis. However, current subtyping (classic, mesenchymal, neural, proneural) is time-consuming and cost-intensive hindering its clinical application. A simple and efficient method for classification was imperative.

Methods

In this study, to simplify GBM subtyping more efficiently, we applied a random forest algorithm to conduct 26 genes as a cluster featured with hub genes, OLIG2 and CD276. Functional enrichment analysis and Protein–protein interaction were performed using the genes in this gene cluster. The classification efficiency of the gene cluster was validated by WGCNA and LASSO algorithms, and tested in GSE84010 and Gravandeel’s GBM datasets.

Results

The gene cluster (n = 26) could distinguish mesenchymal and proneural excellently (AUC = 0.92), which could be validated by multiple algorithms (WGCNA, LASSO) and datasets (GSE84010 and Gravandeel’s GBM dataset). The gene cluster could be functionally enriched in DNA elements and T cell associated pathways. Additionally, five genes in the signature could predict the prognosis well (p = 0.0051 for training cohort, p = 0.065 for test cohort).

Conclusions

Our study proved the accuracy and efficiency of random forest classifier for GBM subtyping, which could provide a convenient and efficient method for subtyping Proneural and Mesenchymal GBM.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12967-021-03083-y.

P4HA2 promotes cell proliferation and migration in glioblastoma

Glioblastoma (GBM) is a primary malignant tumor characterized by high infiltration and angiogenesis in the brain parenchyma. Glioma stem cells (GSCs), a heterogeneous GBM cell type with the potential for self-renewal and differentiation to tumor cells, are responsible for the high malignancy of GBM. The purpose of the present study was to investigate the roles of significantly differentially expressed genes between GSCs and GBM cells in GBM progression. The gene profiles GSE74304 and GSE124145, containing 10 GSC samples and 12 GBM samples in total, were obtained from the Gene Expression Omnibus (GEO) database. The overlapping differentially expressed genes were identified with GEO2R tools and Venn software online. Subsequently, Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analysis was performed on the 41 upregulated and 142 downregulated differentially expressed genes in GSCs compared with in GBM cells via the DAVID website. Protein-protein interaction and module analyses in Cytoscape with the STRING database revealed 21 hub genes that were downregulated in GSCs compared with in GBM cells. Survival analysis conducted via the GEPIA2 website revealed that low expression levels of the hub genes prolyl 4-hydroxylase subunit α2 (P4HA2), TGF-β induced, integrin subunit α3 and thrombospondin 1 were associated with significantly prolonged survival time in patients with GBM. Further experiments were performed focusing on P4HA2. Reverse transcription-quantitative PCR was used to detect P4HA2 gene expression. In agreement with the bioinformatics analysis, P4HA2 expression was higher in U87 cells than in GSCs. Cell Counting Kit-8, EdU incorporation, cell cycle analysis, wound healing and Transwell assays demonstrated that the cell proliferation and migration increased after P4HA2 overexpression and decreased after P4HA2-knockdown. In conclusion, the present study demonstrated that low P4HA2 expression in GSCs promoted GBM cell proliferation and migration, suggesting that P4HA2 may act as a switch in the transition from GSCs to GBM cells.

The Inhibition of B7H3 by 2-HG Accumulation Is Associated With Downregulation of VEGFA in IDH Mutated Gliomas

B7H3 (also known as CD276) is a co-stimulator checkpoint protein of the cell surface B7 superfamily. Recently, the function beyond immune regulation of B7H3 has been widely studied. However, the expression preference and the regulation mechanism underlying B7H3 in different subtypes of gliomas is rarely understood. We show here that B7H3 expression is significantly decreased in IDH-mutated gliomas and in cultured IDH1-R132H glioma cells. Accumulation of 2-HG leads to a remarkable downregulation of B7H3 protein and the activity of IDH1-R132H mutant is responsible for B7H3 reduction in glioma cells. Inhibition of autophagy by inhibitors like leupeptin, chloroquine (CQ), and Bafilomycin A1 (Baf-A1) blocks the degradation of B7H3 in glioma cells. In the meantime, the autophagy flux is more active with higher LC3B-II and lower p62 in IDH1-R132H glioma cells than in IDH1-WT cells. Furthermore, sequence alignment analysis reveals potential LC3-interacting region (LIR) motifs “F-V-S/N-I/V” in B7H3. Moreover, B7H3 interacts with p62 and CQ treatment significantly enhances this interaction. Additionally, we find that B7H3 is positively correlated with VEGFA and MMP2 by bioinformatics analysis in gliomas. B7H3 and VEGFA are decreased in IDH-mutated gliomas and further reduced in 2-HG^high gliomas compared to 2-HG^low glioma sections by IHC staining. Our study demonstrates that B7H3 is preferentially overexpressed in IDH wild-type gliomas and could serve as a potential theranostic target for the precise treatment of glioma patients with wild-type IDH.

Bioinformatics analysis of the circRNA-miRNA-mRNA network for non-small cell lung cancer

OBJECTIVE

Non-small cell lung cancer (NSCLC) accounts for approximately 80% of all lung cancers, but its pathogenesis has not been fully elucidated. Therefore, it is valuable to explore the pathogenesis of NSCLC to improve diagnosis and identify novel treatment biomarkers.

METHODS

Circular (circ)RNA, micro (mi)RNA, and gene expression datasets of NSCLC were analyzed to identify those that were differentially expressed between tumor and healthy tissues. Common genes were found and pathway enrichment analyses were performed. Survival analysis was used to identify hub genes, and their level of methylation and association with immune cell infiltration were analyzed. Finally, an NSCLC circRNA-miRNA-mRNA network was constructed.

RESULTS

Eight miRNAs and 211 common genes were identified. Gene ontology and Kyoto Encyclopedia of Genes and Genomes analyses revealed that cell projection morphogenesis, blood vessel morphogenesis, muscle cell proliferation, and synapse organization were enriched. Ten hub genes were found, of which the expression of DTL and RRM2 was significantly related to NSCLC patient prognosis. Significant methylation changes and immune cell infiltration correlations with DTL and RRM2 were also detected.

CONCLUSIONS

hsa_circ_0001947/hsa-miR-637/RRM2 and hsa_circ_0072305/hsa-miR-127-5p/DTL networks were constructed, and identified molecules may be involved in the occurrence and development of NSCLC.

The expression of B7-H3 isoforms in newly diagnosed glioblastoma and recurrence and their functional role

Short survival of glioblastoma (GBM) patients is due to systematic tumor recurrence. Our laboratory identified a GBM cell subpopulation able to leave the tumor mass (TM) and invade the subventricular zone (SVZ-GBM cells). SVZ-GBM cells escape treatment and appear to contribute to GBM recurrence. This study aims to identify proteins specifically expressed by SVZ-GBM cells and to define their role(s) in GBM aggressiveness and recurrence. The proteome was compared between GBM cells located in the initial TM and SVZ-GBM cells using mass spectrometry. Among differentially expressed proteins, we confirmed B7-H3 by western blot (WB) and quantitative RT-PCR. B7-H3 expression was compared by immunohistochemistry and WB (including expression of its isoforms) between human GBM (N = 14) and non-cancerous brain tissue (N = 8), as well as newly diagnosed GBM and patient-matched recurrences (N = 11). Finally, the expression of B7-H3 was modulated with short hairpin RNA and/or over-expression vectors to determine its functional role in GBM using in vitro assays and a xenograft mouse model of GBM. B7-H3 was a marker for SVZ-GBM cells. It was also increased in human GBM pericytes, myeloid cells and neoplastic cells. B7-H3 inhibition in GBM cells reduced their tumorigenicity. Out of the two B7-H3 isoforms, only 2IgB7-H3 was detected in non-cancerous brain tissue, whereas 4IgB7-H3 was specific for GBM. 2IgB7-H3 expression was higher in GBM recurrences and increased resistance to temozolomide-mediated apoptosis. To conclude, 4IgB7-H3 is an interesting candidate for GBM targeted therapies, while 2IgB7-H3 could be involved in recurrence through resistance to chemotherapy.

A regulatory loop among CD276, miR-29c-3p, and Myc exists in cancer cells against natural killer cell cytotoxicity

AIMS

Immune checkpoints regulate immunity to prevent autoimmunity and protect the host from damage during pathogenic infection. They also participate in subverting immune surveillance and promote antitumor immunity in cancers. Although immunotherapy improves clinical outcomes, not all cancer patients experience expected responses after therapy. Hence, it would be meaningful to explore crucial immune checkpoints in cancers for future immunotherapies.

METHODS AND KEY FINDINGS

By analyzing pan-cancer data in The Cancer Genome Atlas (TCGA), cluster of differentiation 276 (CD276), also known as B7H3, was found to be a risk gene in several cancers. A positive correlation existed between CD276 and natural killer (NK) cell infiltration. Overexpression of CD276 attenuated NK cell-mediated cell killing. Furthermore, CD276 levels showed a significant negative association with microRNA (miR)-29c-3p. Overexpression of miR-29c-3p rescued CD276-reduced NK cell cytotoxicity. According to gene set enrichment analyses, CD276-associated genes were found to be enriched in genes that targeted Myc. A negative correlation existed between miR-29 expression and Myc activity. CD276 enhanced Myc phosphorylation levels while suppressing miR-29c-3p expression. In contrast, miR-29c-3p inhibited CD276 expression, leading to reduced Myc activity. Myc suppressed miR-29c-3p expression while promoting CD276 upregulation.

SIGNIFICANCE

These findings suggest that a negative regulatory loop among CD276, Myc, and miR-29c-3p influences cancer cells against NK cell cytotoxicity.

The Role of CD276 in Cancers

Objective

Aberrant expression of the immune checkpoint molecule, CD276, also known as B7-H3, is associated with tumorigenesis. In this review, we aim to comprehensively describe the role of CD276 in malignancies and its potential therapeutic effect.

Data Sources

Database including PubMed, EMbase, Cochrane Library, CNKI, and Clinical Trails.gov were searched for eligible studies and reviews. Study selection: Original studies and review articles on the topic of CD276 in tumors were retrieved.

Results

CD276 is an immune checkpoint molecule in the epithelial mesenchymal transition (EMT) pathway. In this review, we evaluated the available evidence on the expression and regulation of CD276. We also assessed the role of CD276 within the immune micro-environment, effect on tumor progression, and the potential therapeutic effect of CD276 targeted therapy for malignancies.

Conclusion

CD276 plays an essential role in cell proliferation, invasion, and migration in malignancies. Results from most recent studies indicate CD276 could be a promising therapeutic target for malignant tumors.

PDIA5 is Correlated With Immune Infiltration and Predicts Poor Prognosis in Gliomas

Gliomas are the most common and lethal primary malignant tumor of the brain. Routine treatment including surgical resection, chemotherapy, and radiotherapy produced limited therapeutic effect, while immunotherapy targeting the glioma microenvironment has offered a novel therapeutic option. PDIA5 protein is the member of PDI family, which is highly expressed in glioma and participates in glioma progression. Based on large-scale bioinformatics analysis, we discovered that PDIA5 expression level is upregulated in aggressive gliomas, with high PDIA5 expression predicting poor clinical outcomes. We also observed positive correlation between PDIA5 and immune infiltrating cells, immune related pathways, inflammatory activities, and other immune checkpoint members. Patients with high PDIA5 high-expression benefited from immunotherapies. Additionally, immunohistochemistry revealed that PDIA5 and macrophage biomarker CD68 were upregulated in high-grade gliomas, and patients with low PDIA5 level experienced favorable outcomes among 33 glioma patients. Single cell RNA sequencing exhibited that PDIA5 was in high level presenting in neoplastic cells and macrophages. Cell transfection and co-culture of glioma cells and macrophages revealed that PDIA5 in tumor cells mediated macrophages exhausting. Altogether, our findings indicate that PDIA5 overexpression is associated with immune infiltration in gliomas, and may be a promising therapeutic target for glioma immunotherapy.

PathoFusion: An Open-Source AI Framework for Recognition of Pathomorphological Features and Mapping of Immunohistochemical Data

We have developed a platform, termed PathoFusion, which is an integrated system for marking, training, and recognition of pathological features in whole-slide tissue sections. The platform uses a bifocal convolutional neural network (BCNN) which is designed to simultaneously capture both index and contextual feature information from shorter and longer image tiles, respectively. This is analogous to how a microscopist in pathology works, identifying a cancerous morphological feature in the tissue context using first a narrow and then a wider focus, hence bifocal. Adjacent tissue sections obtained from glioblastoma cases were processed for hematoxylin and eosin (H&E) and immunohistochemical (CD276) staining. Image tiles cropped from the digitized images based on markings made by a consultant neuropathologist were used to train the BCNN. PathoFusion demonstrated its ability to recognize malignant neuropathological features autonomously and map immunohistochemical data simultaneously. Our experiments show that PathoFusion achieved areas under the curve (AUCs) of 0.985 ± 0.011 and 0.988 ± 0.001 in patch-level recognition of six typical pathomorphological features and detection of associated immunoreactivity, respectively. On this basis, the system further correlated CD276 immunoreactivity to abnormal tumor vasculature. Corresponding feature distributions and overlaps were visualized by heatmaps, permitting high-resolution qualitative as well as quantitative morphological analyses for entire histological slides. Recognition of more user-defined pathomorphological features can be added to the system and included in future tissue analyses. Integration of PathoFusion with the day-to-day service workflow of a (neuro)pathology department is a goal. The software code for PathoFusion is made publicly available.

Computational analysis and verification of molecular genetic targets for glioblastoma

BACKGROUND

Glioblastoma (GBM) is the most common malignant brain tumor with a poor prognosis. The initial treatment for high-grade gliomas is surgical excision. However, even with concomitant use of radiation or chemotherapy, patients are still prone to recurrence. The specific pathogenesis of GBM is still controversial.

METHODS

Differentially expressed genes (DEGs) and differentially expressed miRNAs (DEMs) between GBM and normal brain tissues were screened. P-value was obtained by Bayes test based on the limma package. Statistical significance was set as P-value <0.05 and |Fold change (FC)| > 0.2 (GSE90886); P-value <0.05 and |FC| > 1 (GSE116520, GSE103228). Gene Ontology (GO) analysis, Kyoto Encyclopedia of Genes and Genomes (KEGG), protein-protein interaction (PPI) network were performed. Hub genes were selected from miRNA target genes and DEGs. GBM and normal brain tissues were extracted to verify the expression.

RESULTS

A total of 100 DEGs were overlapped in both datasets. Analysis of pathways and process enrichment tests indicated that ion transport, positive regulation of macromolecule metabolic process, cell cycle, axon guidance were enriched in the GBM. Sixteen hub genes were identified. Hub genes ADARB1 and neuropilin 1 (NRP1) were significantly associated with overall survival (OS) and disease-free survival (DFS) (P<0.05). Eukaryotic translation termination factor 1 (ETF1) was associated with DFS (P<0.05).

CONCLUSIONS

DEGs and DEMs were found between GBM tumor tissues and normal brain tissues. These biomarkers may be used as targets for early diagnosis and specific treatment.

Survival Association and Cell Cycle Effects of B7H3 in Neuroblastoma

Objective

The function of B7H3, a member of the B7 family of proteins, in neuroblastoma (NB) remains poorly characterized. Here we examine the expression pattern of B7H3 in clinical NB specimens and characterize the phenotype of B7H3 knock-down in NB cell line.

Methods

Immunohistochemical (IHC) staining was carried out to assess the expression of B7H3 in clinical NB specimens. Survival association was analyzed using five Gene Expression Omnibus (GEO) datasets (GSE85047, GSE45480, GSE62564, GSE16476, GSE49710). Clonogenic survival and flow cytometry were performed after B7H3 knockdown to assess the cellular proliferation and cell survival in vitro. Impact of B7H3 silencing on NB growth was examined in vivo using the SH-SY5Y xenograft model.

Results

On IHC staining, B7H3 was widely expressed in clinical NB specimens. Analysis of the transcriptional profiles of five GEO datasets clinically annotated NB specimens revealed that decreased B7H3 expression was associated with improved overall survival. B7H3 knockdown suppressed the proliferation of the SH-SY5Y NB model in vitro and in vivo. Cell cycle analysis revealed that B7H3 silencing induced G1/S arrest. This arrest was associated with the suppression of E2F1 expression and induction of Rb expression.

Conclusion

Our results demonstrate that B7H3 expression correlate with clinical survival in NB patients. Preliminary studies suggest that B7H3 may mediate the G1/S transition.

High-resolution structural genomics reveals new therapeutic vulnerabilities in glioblastoma

We investigated the role of 3D genome architecture in instructing functional properties of glioblastoma stem cells (GSCs) by generating sub-5-kb resolution 3D genome maps by in situ Hi-C. Contact maps at sub-5-kb resolution allow identification of individual DNA loops, domain organization, and large-scale genome compartmentalization. We observed differences in looping architectures among GSCs from different patients, suggesting that 3D genome architecture is a further layer of inter-patient heterogeneity for glioblastoma. Integration of DNA contact maps with chromatin and transcriptional profiles identified specific mechanisms of gene regulation, including the convergence of multiple super enhancers to individual stemness genes within individual cells. We show that the number of loops contacting a gene correlates with elevated transcription. These results indicate that stemness genes are hubs of interaction between multiple regulatory regions, likely to ensure their sustained expression. Regions of open chromatin common among the GSCs tested were poised for expression of immune-related genes, including CD276. We demonstrate that this gene is co-expressed with stemness genes in GSCs and that CD276 can be targeted with an antibody-drug conjugate to eliminate self-renewing cells. Our results demonstrate that integrated structural genomics data sets can be employed to rationally identify therapeutic vulnerabilities in self-renewing cells.