Deciphering the complex role of thrombospondin-1 in glioblastoma development

Comparative proteomic profiling of glioblastoma and healthy brain cell-derived extracellular vesicles reveals enrichment of cancer-associated proteins

Extracellular vesicles (EVs)-mediated cellular communication plays a role in cancer development and progression. This study focuses on identifying glioblastoma-specific EV protein markers through a comparative mass spectrometry bottom-up proteomic analysis of the LN-229 cell line and human neurons, astrocytes, and endothelial brain cells (HEBCs) using timsTOF Pro 2 instrument. The statistically significant upregulated proteins with fold change greater than 2 in the glioblastoma-derived EVs were clustered based on physical and functional interactions using the STRING database and analyzed using Gene Ontology enrichment. LN229-derived EVs contained an average of 2635 proteins, while human astrocytes, neurons, and HEBC encapsulated 2647, 716, and 2285 proteins, respectively. NanoParticle Tracking Analysis indicated that glioblastoma-derived EVs exhibited greater size variability compared to EVs from healthy cells. Statistical analysis identified 25 statistically significant proteins with increased levels in LN229 EVs relative to at least two healthy cell lines suggesting their potential as glioblastoma markers. Functional clustering using the STRING database and GO analysis indicated involvement in epigenetic regulation, metastasis, angiogenesis, and protein folding. Post-translational modification analysis identified a subset of 17 proteins unique to the cancer-derived EVs involved in chromatin regulation, extracellular matrix remodeling, and basement membrane organization pathways, highlighting their role in tumor progression.

Glioma-neuronal circuit remodeling induces regional immunosuppression

Neuronal activity-driven mechanisms influence glioblastoma cell proliferation and invasion, while glioblastoma remodels neuronal circuits. Although a subpopulation of malignant cells enhances neuronal connectivity, their impact on the immune system remains unclear. Here, we show that glioblastoma regions with enhanced neuronal connectivity exhibit regional immunosuppression, characterized by distinct immune cell compositions and the enrichment of anti-inflammatory tumor-associated macrophages (TAMs). In preclinical models, knockout of Thrombospondin-1 (TSP1/Thbs1) in glioblastoma cells suppresses synaptogenesis and glutamatergic neuronal hyperexcitability. Furthermore, TSP1 knockout restores antigen presentation-related genes, promotes the infiltration of pro-inflammatory TAMs and CD8 + T-cells in the tumor, and alleviates TAM-mediated T-cell suppression. Pharmacological inhibition of glutamatergic signaling also shifts TAMs toward a less immunosuppressive state, prolongs survival in mice, and shows the potential to enhance the efficacy of immune cell-based therapy. These findings confirm that glioma-neuronal circuit remodeling is strongly linked with regional immunosuppression and suggest that targeting glioma-neuron-immune crosstalk could provide avenues for immunotherapy.

Predicting Treatment Outcomes in Glioblastoma: A Risk Score Model for TMZ Resistance and Immune Checkpoint Inhibition

Glioblastoma (GBM) presents significant therapeutic challenges due to its invasive nature and resistance to standard chemotherapy, i.e., temozolomide (TMZ). This study aimed to identify gene signatures that predict poor TMZ response and high PD-L1/PD-1 tumor expression, and explore potential sensitivity to alternative drugs. We analyzed The Cancer Genome Atlas (TCGA) biopsy data to identify differentially expressed genes (DEGs) linked to these characteristics. Among 33 upregulated DEGs, 5 were significantly correlated with overall survival. A risk score model was built using these 5 DEGs, classifying patients into low-, medium-, and high-risk groups. We assessed immune cell infiltration, immunosuppressive mediators, and epithelial-mesenchymal transition (EMT) markers in each group using correlation analysis, Gene Set Enrichment Analysis (GSEA), and machine learning. The model demonstrated strong predictive power, with high-risk patients exhibiting poorer survival and increased immune infiltration. GSEA revealed upregulation of immune and EMT-related pathways in high-risk patients. Our analyses suggest that high-risk patients may exhibit limited response to PD-1 inhibitors, but could show sensitivity to etoposide and paclitaxel. This risk score model provides a valuable tool for guiding therapeutic decisions and identifying alternative chemotherapy options to enable the development of personalized and cost-effective treatments for GBM patients.

[Genetic profiling of parathyroid tumours: lifting the veil of mystery]

Primary hyperparathyroidism (PHPT) is a common endocrine disorder characterized by autonomous secretion of parathyroid hormone by altered parathyroid glands. In most cases PHPT is a sporadic disease, 5-10% of observations are genetically determined syndromal and non-syndromal forms. Studies of families with hereditary forms of PHPT have led to the discovery of key oncosuppressor genes and proto-oncogenes whose somatic mutations underlie the development of many sporadic parathyroid tumors. Another interest in the pathogenesis of primary hyperparathyroidism is studying mechanisms of epigenetic regulation in tumor tissue. In the first part of this review, we will discuss the classification, morphology, and etiology of PHPT. In the second part, we will present a summary of the most important studies using genetic analysis, classified according to the method used.

The role of SPI1/VSIG4/THBS1 on glioblastoma progression through modulation of the PI3K/AKT pathway

INTRODUCTION

Glioblastoma multiforme (GBM) poses a significant challenge in terms of treatment due to its high malignancy, necessitating the identification of additional molecular targets. VSIG4, an oncogenic gene participates in tumor growth and migration in various cancer types. Nevertheless, the precise process through which VSIG4 facilitates the malignant progression of glioma remains to be elucidated.

OBJECTIVES

This research aims to explore the function and molecular mechanism involving VSIG4 in the malignant progression of glioma.

METHODS

The amount of VSIG4 was measured using qPCR, western blotting, and immunohistochemistry. Lentivirus infections were applied for upregulating or downregulating molecules within glioma cells. The incorporation of 5-ethynyl-20-deoxyuridine, Transwell, cell counting kit-8, and clone formation experiments, were applied to assess the biological functions of molecules on glioma cells. Dual luciferase reporter gene, RNA immunoprecipitation, and chromatin immunoprecipitation assays were used to explore the functional relationship among relevant molecules.

RESULTS

The upregulation of VSIG4 was observed in GBM tissues, indicating an adverse prognosis. Silencing VSIG4 in glioma cells resulted in a decrease in cell viability, invasion, proliferation, and tumorigenesis, an increase in cell apoptosis, and a stagnation in the cell cycle progression at the G0/G1 phase. Mechanistically, SPI1-mediated upregulation of VSIG4 expression led to binding between VSIG4 and THBS1 protein, ultimately facilitating the malignant progression of glioma cells through the activation of the PI3K/AKT pathway. The inhibited proliferative and invasive capabilities of glioma cells were reversed by overexpressing THBS1 following the knockdown of VSIG4.

CONCLUSION

Our findings provide evidence for the role of VSIG4 as an oncogene and reveal the previously unidentified contribution of the SPI1/VSIG4/THBS1 axis in the malignant progression of glioma. This signaling cascade enhances tumor growth and invasion by modulating the PI3K/AKT pathway. VSIG4 as a potential biomarker may be a viable strategy in the development of tailored molecular therapies for GBM.

Advancing glioblastoma therapy: Learning from the past and innovations for the future

Marred by a median survival of only around 12-15 months coupled with poor prognosis and effective therapeutic deprived drug armory, treatment/management of glioblastoma has proved to be a daunting task. Surgical resection, flanked by radiotherapy and chemotherapy with temozolomide, stands as the standard of care; however, this trimodal therapy often manifests limited efficacy due to the heterogeneous and highly infiltrative nature of GBM cells. In addition, the existence of the blood-brain barrier, tumor microenvironment, and the immunosuppressive nature of GBM, along with the encountered resistance of GBM cells towards conventional therapy, also hinders the therapeutic applications of chemotherapeutics in GBM. This review presents key insights into the molecular pathology of GBM, including genetic mutations, signaling pathways, and tumor microenvironment characteristics. Recent innovations such as immunotherapy, oncolytic viral therapies, vaccines, nanotechnology, electric field, and cancer neuroscience, as well as their clinical progress, have been covered. In addition, this compilation also encompasses a discussion on the role of personalized medicine in tailoring treatments based on individual tumor profiles, an approach that is gradually shifting the paradigm in GBM management. Endowed with the learnings imbibed from past failures coupled with the zeal to embrace novel/multidisciplinary approaches, researchers appear to be on the right track to pinpoint more effective and durable solutions in the context of GBM treatment.

Neurotransmitter power plays: the synaptic communication nexus shaping brain cancer

Gliomas and brain metastases are notorious for their dismal prognosis and low survival rates, a challenge exacerbated by our incomplete grasp of the complex dynamics that govern brain cancers. Recently, a groundbreaking paradigm shift has emerged, highlighting the crucial role of synaptic communication between neurons and brain tumor cells in reshaping neuronal signaling to favor tumor growth. This review delves into the pivotal interplay of synaptic mechanisms, focusing on excitatory glutamatergic and inhibitory GABAergic pathways. Glutamatergic synapses utilize glutamate to propagate excitatory signals, while GABAergic synapses employ gamma-aminobutyric acid (GABA) to inhibit neuronal firing. Glutamatergic signaling can be broadly classified into ionotropic (NMDAR, AMPAR and kainite receptors) and metabotropic subtypes. The harmonious orchestration of these synaptic types is essential for normal brain function, and their dysregulation is implicated in neurodegenerative disorders such as Alzheimer's disease and epilepsy. Emerging evidence reveals that glioma and brain metastatic cells exploit these synaptic pathways and neurotransmitters to enhance their proliferation and survival. In this review, we will first explore the intricate mechanisms underlying glutamatergic and GABAergic signaling. Next, we will summarize recent advancements in understanding how brain cancer cells hijack these pathways to their advantage. Finally, we will propose novel therapeutic strategies aimed at disrupting the aberrant neuron-tumor synaptic communication, offering potential treatment strategies for combating these otherwise incurable brain cancers.

Spatial synaptic connectivity underlies oligodendroglioma evolution and recurrence

Oligodendrogliomas are initially slow-growing brain tumors that are prone to malignant transformation despite surgery and cytotoxic therapy. Understanding of oligodendroglioma evolution and new treatments for patients have been encumbered by a paucity of patient-matched newly diagnosed and recurrent tumor samples for multiplatform analyses, and by a lack of preclinical models for interrogation of therapeutic vulnerabilities that drive oligodendroglioma growth. Here we integrate spatial and functional analyses of tumor samples and patient-derived organoid co-cultures to show that synaptic connectivity is a hallmark of oligodendroglioma evolution and recurrence. We find that patient-matched recurrent oligodendrogliomas are enriched in synaptic gene expression programs irrespective of previous therapy or histologic grade. Analyses of spatial, single-cell, and clinical data reveal epigenetic misactivation of synaptic genes that are concentrated in regions of cortical infiltration and can be used to predict eventual oligodendroglioma recurrence. To translate these findings to patients, we show that local field potentials from tumor-infiltrated cortex at the time of resection and neuronal hyperexcitability and synchrony in patient-derived organoid co-cultures are associated with oligodendroglioma proliferation and recurrence. In preclinical models, we find that neurophysiologic drugs block oligodendroglioma growth and pathologic electrophysiology. These results elucidate mechanisms underlying oligodendroglioma evolution from an indolent tumor to a fatal disease and shed light on new biomarkers and new treatments for patients.

Tumor microtubes: A new potential therapeutic target for high-grade gliomas

High-grade infiltrating gliomas are highly aggressive and fatal brain tumors that present significant challenges for research and treatment due to their complex microenvironment and tissue structure. Recent discovery of tumor microtubes (TMs) has provided new insights into how high-grade gliomas develop in the brain and resist treatment. TMs are unique, ultra-long, and highly functional membrane protrusions that form multicellular networks and play crucial roles in glioma invasiveness, drug resistance, recurrence, and heterogeneity. This review focuses on the different roles that TMs play in glioma cell communication, material transport, and tumor cell behavior. Specifically, non-connecting TMs primarily promote glioma invasiveness, likely related to their role in enhancing cell motility. On the other hand, interconnecting TMs form functional and communication networks by connecting with surrounding astrocytes and neurons, thereby promoting glioma malignancy. We summarize the factors that influence the formation of TMs in gliomas and current strategies targeting TMs. As the understanding of TMs advances, we are closer to uncovering whether they might be the long-sought Achilles' heel of treatment-resistant gliomas. By delving deeper into TMs research, we hope to develop more effective therapeutic strategies for patients with malignant gliomas.

Using DIMet for Differential Analysis of Labeled Metabolomics Data: A Step-by-step Guide Showcasing the Glioblastoma Metabolism

Stable-isotope resolved metabolomics (SIRM) is a powerful approach for characterizing metabolic states in cells and organisms. By incorporating isotopes, such as 13C, into substrates, researchers can trace reaction rates across specific metabolic pathways. Integrating metabolomics data with gene expression profiles further enriches the analysis, as we demonstrated in our prior study on glioblastoma metabolic symbiosis. However, the bioinformatics tools for analyzing tracer metabolomics data have been limited. In this protocol, we encourage the researchers to use SIRM and transcriptomics data and to perform the downstream analysis using our software tool DIMet. Indeed, DIMet is the first comprehensive tool designed for the differential analysis of tracer metabolomics data, alongside its integration with transcriptomics data. DIMet facilitates the analysis of stable-isotope labeling and metabolic abundances, offering a streamlined approach to infer metabolic changes without requiring complex flux analysis. Its pathway-based "metabologram" visualizations effectively integrate metabolomics and transcriptomics data, offering a versatile platform capable of analyzing corrected tracer datasets across diverse systems, organisms, and isotopes. We provide detailed steps for sample preparation and data analysis using DIMet through its intuitive, web-based Galaxy interface. To showcase DIMet's capabilities, we analyzed LDHA/B knockout glioblastoma cell lines compared to controls. Accessible to all researchers through Galaxy, DIMet is free, user-friendly, and open source, making it a valuable resource for advancing metabolic research. Key features • Glioblastoma tumor spheroids in vitro replicate tumors' three-dimensional structure and natural nutrient, metabolite, and gas gradients, providing a more realistic model of tumor biology. • Joint analysis of tracer metabolomics and transcriptomics datasets provides deeper insights into the metabolic states of cells. • DIMet is a web-based tool for differential analysis and seamless integration of metabolomics and transcriptomics data, making it accessible and user-friendly. • DIMet enables researchers to infer metabolic changes, offering intuitive and visually appealing "metabologram" outputs, surpassing conventional visual representations commonly used in the field.

Recent Developments in Glioblastoma-On-A-Chip for Advanced Drug Screening Applications

Glioblastoma (GBM) is an aggressive form of cancer, comprising ≈80% of malignant brain tumors. However, there are no effective treatments for GBM due to its heterogeneity and the presence of the blood-brain barrier (BBB), which restricts the delivery of therapeutics to the brain. Despite in vitro models contributing to the understanding of GBM, conventional 2D models oversimplify the complex tumor microenvironment. Organ-on-a-chip (OoC) models have emerged as promising platforms that recapitulate human tissue physiology, enabling disease modeling, drug screening, and personalized medicine. There is a sudden increase in GBM-on-a-chip models that can significantly advance the knowledge of GBM etiology and revolutionize drug development by reducing animal testing and enhancing translation to the clinic. In this review, an overview of GBM-on-a-chip models and their applications is reported for drug screening and discussed current challenges and potential future directions for GBM-on-a-chip models.

Endothelial Dysfunction in the Tubule Area Accelerates the Progression of Early Diabetic Kidney Disease

Diabetic kidney disease (DKD) is the leading cause of end-stage renal disease. Therefore, understanding the molecular regulatory mechanisms underlying the pathogenesis of DKD is imperative. In this study, we aimed to explore the molecular mechanisms of tubule region endothelial dysfunction in early DKD. Early-stage DKD model was established in 16-week-old female db/db mice for 16 weeks. Body weight, glucose level, and urine albumin-to-creatinine ratio (UACR) were measured. Hematoxylin and eosin (H&E) and periodic acid-Schiff (PAS) staining were performed to evaluate pathological lesions. RNA sequencing data of the kidneys and integrated publicly available single-cell and spatial transcriptome datasets were used to investigate the mechanism of endothelial dysfunction. There was a significant increase in body weight (p = 0.001), glucose levels (p=0.0008), and UACR (p=0.006) in db/db mice compared with db/m mice. H&E and PAS staining showed that vacuolar lesions and protein casts of tubules were the major histopathological changes observed in early-stage DKD mice. The apoptotic pathway in endothelial cells was notably activated in DKD, and Thbs1 was identified as the central gene involved in this apoptotic process. Deconvolution of the cell composition in the RNA sequencing data showed a decrease in the proportion of endothelial cells in the DKD mice. Further analysis of the activity and regulatory network of transcription factors showed that Creb1 was activated in both mouse and human early-stage DKD, suggesting that Creb1 activation may be involved in early kidney injury. The endothelial cell apoptotic pathway is activated in DKD, and the proportion of endothelial cells was reduced in the DKD mice, which is significantly associated with Thbs1. Keywords: Diabetic kidney disease, Endothelial dysfunction, RNA sequencing,Thbs1, Creb1.

Promoter hypermethylation-mediated downregulation of PAX6 promotes tumor growth and metastasis during the progression of liver cancer

BACKGROUND

The progression of liver cancer is a complicated process that involves genetic and epigenetic changes. Paired box 6 (PAX6) is a critical transcription factor for embryonic development. PAX6 is abnormally methylated in human cancer. The role of the PAX6 gene in the pathogenesis of hepatocellular carcinoma (HCC) is still unclear.

METHODS

Transcriptional silencing of PAX6 mediated by promoter methylation was confirmed using quantitative methylation-specific polymerase chain reaction (PCR) and reverse-transcription (RT)-PCR. Then we conducted gain-and-loss of function approaches to evaluate the function of PAX6 in HCC progression in vitro. Moreover, we designed xenograft mouse models to assess the effect of PAX6 on tumor growth and metastasis. Finally, we used RNA sequencing (RNA-seq) strategy and phenotypic rescue experiments to identify potential targets of PAX6 performing tumor-suppressive function.

RESULTS

Constitutive expression of PAX6 suppressed anchorage-independent growth and cell invasion in vitro as well as tumor growth and metastasis in xenograft mouse models. In contrast, the inhibition of PAX6 using knockout and knockdown strategies increased tumor growth both in vitro and in vivo. Downregulation of PAX6 by doxycycline depletion partially reversed the malignant phenotypes of HCC cells induced by PAX6. Moreover, we identified E-cadherin (CDH1) and thrombospondin-1 (THBS1) as targets of PAX6. Ultimately, we demonstrated that the knockdown of CDH1 and overexpression of THBS1 in PAX6-expressing HCC cells partly reversed the tumor-suppressive effect.

CONCLUSION

PAX6 functions as a tumor suppressor partly through upregulation of CDH1 and downregulation of THBS1. Promoter hypermethylation-mediated suppression of PAX6 reduces the tumor suppressor function in the progression of liver cancer.

The TβRI promotes migration and metastasis through thrombospondin 1 and ITGAV in prostate cancer cells

TGFβ potently modifies the extracellular matrix (ECM), which is thought to favor tumor cell invasion. However, the mechanism whereby the cancer cells employ the ECM proteins to facilitate their motility is largely unknown. In this study we used RNA-seq and proteomic analysis to examine the proteins secreted by castration-resistant prostate cancer (CRPC) cells upon TGFβ treatment and found that thrombospondin 1 (THBS1) was observed to be one of the predominant proteins. The CRISPR Cas9, or siRNA techniques was used to downregulate TGFβ type I receptor (TβRI) to interfere with TGFβ signaling in various cancer cells in vitro. The interaction of ECM proteins with the TβRI in the migratory prostate cancer cells in response to TGFβ1 was demonstrated by several different techniques to reveal that THBS1 mediates cell migration by interacting with integrin subunit alpha V (ITGAV) and TβRI. Deletion of TβRI or THBS1 in cancer cells prevented their migration and invasion. THBS1 belongs to a group of tumorigenic ECM proteins induced via TGFβ signaling in CRPC cells, and high expression of THBS1 in human prostate cancer tissues correlated with the degree of malignancy. TGFβ-induced production of THBS1 through TβRI facilitates the invasion and metastasis of CRPC cells as shown in vivo xenograft animal experiments.

Oncogenic KRAS-Dependent Stromal Interleukin-33 Directs the Pancreatic Microenvironment to Promote Tumor Growth

Pancreatic cancer is characterized by an extensive fibroinflammatory microenvironment. During carcinogenesis, normal stromal cells are converted to cytokine-high cancer-associated fibroblasts (CAF). The mechanisms underlying this conversion, including the regulation and function of fibroblast-derived cytokines, are poorly understood. Thus, efforts to therapeutically target CAFs have so far failed. Herein, we show that signals from epithelial cells expressing oncogenic KRAS-a hallmark pancreatic cancer mutation-activate fibroblast autocrine signaling, which drives the expression of the cytokine IL33. Stromal IL33 expression remains high and dependent on epithelial KRAS throughout carcinogenesis; in turn, environmental stress induces interleukin-33 (IL33) secretion. Using compartment-specific IL33 knockout mice, we observed that lack of stromal IL33 leads to profound reprogramming of multiple components of the pancreatic tumor microenvironment, including CAFs, myeloid cells, and lymphocytes. Notably, loss of stromal IL33 leads to an increase in CD8+ T-cell infiltration and activation and, ultimately, reduced tumor growth. Significance: This study provides new insights into the mechanisms underlying the programming of CAFs and shows that during this process, expression of the cytokine IL33 is induced. CAF-derived IL33 has pleiotropic effects on the tumor microenvironment, supporting its potential as a therapeutic target.

Predicting gene signature in breast cancer patients with multiple machine learning models

AIMS

The aim of this study was to predict gene signatures in breast cancer patients using multiple machine learning models.

METHODS

In this study, we first collated and merged the datasets GSE54002 and GSE22820, obtaining a gene expression matrix comprising 16,820 genes (including 593 breast cancer (BC) samples and 26 normal control (NC) samples). Subsequently, we performed enrichment analyses using Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and Disease Ontology (DO).

RESULTS

We identified 177 differentially expressed genes (DEGs), including 40 up-regulated and 137 down-regulated genes, through differential expression analysis. The GO enrichment results indicated that these genes are primarily involved in extracellular matrix organization, positive regulation of nervous system development, collagen-containing extracellular matrix, heparin binding, glycosaminoglycan binding, and Wnt protein binding, among others. KEGG enrichment analysis revealed that the DEGs were primarily associated with pathways such as focal adhesion, the PI3K-Akt signaling pathway, and human papillomavirus infection. DO enrichment analysis showed that the DEGs play a significant role in regulating diseases such as intestinal disorders, nephritis, and dermatitis. Further, through LASSO regression analysis and SVM-RFE algorithm analysis, we identified 9 key feature DEGs (CF-DEGs): ANGPTL7, TSHZ2, SDPR, CLCA4, PAMR1, MME, CXCL2, ADAMTS5, and KIT. Additionally, ROC curve analysis demonstrated that these CF-DEGs serve as a reliable diagnostic index. Finally, using the CIBERSORT algorithm, we analyzed the infiltration of immune cells and the associations between CF-DEGs and immune cell infiltration across all samples.

CONCLUSIONS

Our findings provide new insights into the molecular functions and metabolic pathways involved in breast cancer, potentially aiding in the discovery of new diagnostic and immunotherapeutic biomarkers.

Acquired Temozolomide Resistance Instructs Patterns of Glioblastoma Behavior in Gelatin Hydrogels

Acquired drug resistance in glioblastoma (GBM) presents a major clinical challenge and is a key factor contributing to abysmal prognosis, with less than 15 months median overall survival. Aggressive chemotherapy with the frontline therapeutic, temozolomide (TMZ), ultimately fails to kill residual highly invasive tumor cells after surgical resection and radiotherapy. Here, a 3D engineered model of acquired TMZ resistance is reported using two isogenically matched sets of GBM cell lines encapsulated in gelatin methacrylol hydrogels. Response of TMZ-resistant versus TMZ-sensitive GBM cell lines within the gelatin-based extracellular matrix platform is benchmarked and drug response at physiologically relevant TMZ concentrations is further validated. The changes in drug sensitivity, cell invasion, and matrix-remodeling cytokine production are shown as the result of acquired TMZ resistance. This platform lays the foundation for future investigations targeting key elements of the GBM tumor microenvironment to combat GBM's devastating impact by advancing the understanding of GBM progression and treatment response to guide the development of novel treatment strategies.

Gliomedin drives gastric cancer cell proliferation and migration, correlating with a poor prognosis

Gastric cancer (GC) is a prevalent global malignancy, often diagnosed at advanced stage due to a lack of early symptoms and reliable markers. Previous research has identified gliomedin (GLDN) as a potential predictive marker for poor prognosis in cancer patients. However, the specific relationship between GLDN expression and GC prognosis has been unclear. Using the Tumor-Immune System Interaction Database (TISIDB), we examined GLDN expression in GC tissues and found a positive correlation with advanced clinical stages. Kaplan-Meier Plotter analysis further demonstrated that elevated GLDN levels were closely associated with poor prognosis in GC patients. To explore the functional significance of GLDN in GC, we conducted experiments involving GLDN overexpression and knockdown in GC cell lines, as well as subcutaneous tumor formation in nude mice. Our findings provided compelling evidence that GLDN promotes GC cell proliferation, viability, and migration, significantly enhancing tumor growth in vivo. Mechanistically, RNA-sequencing (RNA-seq) combined with bioinformatics analysis revealed that GLDN influences genes enriched in the p53 signaling pathway. Our data suggest that GLDN likely regulates cell proliferation through the p53-p21-CyclinD/CDK4 signaling axis. In conclusion, our study underscores GLDN's critical role in regulating GC cell proliferation and migration, and proposes its potential as a prognostic marker for GC patients.

The Proteomic Landscape of Monocytes in Response to Colorectal Cancer Cells

Colorectal cancer (CRC) involves a complex interaction between tumor cells and immune cells, notably monocytes, leading to immunosuppression. This study explored these interactions using in vitro coculture systems of THP-1 cells and CRC cell lines, employing quantitative proteomics to analyze protein changes in monocytes. Multiple analytical methods were utilized to delineate the altered proteomic landscape, identify key proteins, and their associated functional pathways for comprehensive data analysis. Differentially expressed proteins (DEPs) were selected and validated by cross-referencing them with publicly available TCGA and GEO data sets to explore their potential clinical significance. Our analysis identified 161 up-regulated and 130 down-regulated DEPs. The enrichment results revealed impairments in adhesion and innate immune functions in monocytes, potentially facilitating cancer progression. The down-regulation of FN1, THSB1, and JUN may contribute to these impairments. Furthermore, the overexpression of ADAMTSL4, PRAM1, GPNMB, and NPC2 on monocytes was associated with unfavorable prognostic outcomes in CRC patients, suggesting potential biomarkers or therapeutic targets. This study illustrated the proteomic landscape of monocytes in response to CRC cells, providing clues for future investigations of the crosstalk between cancer cells and monocytes within the tumor microenvironment.

Deciphering the role of CD47 in cancer immunotherapy

BACKGROUND

Immunotherapy has emerged as a novel strategy for cancer treatment following surgery, radiotherapy, and chemotherapy. Immune checkpoint blockade and Chimeric antigen receptor (CAR)-T cell therapies have been successful in clinical trials. Cancer cells evade immune surveillance by hijacking inhibitory pathways via overexpression of checkpoint genes. The Cluster of Differentiation 47 (CD47) has emerged as a crucial checkpoint for cancer immunotherapy by working as a "don't eat me" signal and suppressing innate immune signaling. Furthermore, CD47 is highly expressed in many cancer types to protect cancer cells from phagocytosis via binding to SIRPα on phagocytes. Targeting CD47 by either interrupting the CD47-SIRPα axis or combing with other therapies has been demonstrated as an encouraging therapeutic strategy in cancer immunotherapy. Antibodies and small molecules that target CD47 have been explored in pre- and clinical trials. However, formidable challenges such as the anemia and palate aggregation cannot be avoided because of the wide presentation of CD47 on erythrocytes.

AIM OF VIEW

This review summarizes the current knowledge on the regulation and function of CD47, and provides a new perspective for immunotherapy targeting CD47. It also highlights the clinical progress of targeting CD47 and discusses challenges and potential strategies.

KEY SCIENTIFIC CONCEPTS OF REVIEW

This review provides a comprehensive understanding of targeting CD47 in cancer immunotherapy, it also augments the concept of combination immunotherapy strategies by employing both innate and adaptive immune responses.

Identification of ECM and EMT relevant genes involved in the progression of bladder cancer through bioinformatics analysis

BACKGROUND

Bladder cancer (BC) is very common among cancers of urinary system. It was usually categorized into two types: non-muscle invasive bladder cancer (NMIBC) and muscle invasive bladder cancer (MIBC). NMIBC and MIBC groupings are heterogeneous and have different characteristics.

OBJECTIVES

The study was aimed to find some hub genes and related signal pathways which might be engaged in the progression of BC and to investigate the relationship with clinical stages and its prognostic significance.

METHODS

GSE37317 datasets were acquired from Gene Expression Omnibus (GEO) database. GEO2R on-line tool was selected to screen the differentially expressed genes (DEGs) of the two different types of BC. Then, Gene Ontology (GO) enrichment and KOBAS-Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis of these DEGs were conducted. A protein-protein interaction (PPI) network was employed to help us screen hub genes and find significant modules. Finally, we made analysis of gene expression and survival curve by GEPIA and Kaplan-Meier plotter database.

RESULTS

224 DEGs were screened in total, with 110 showing increased expression and 114 demonstrating decreased expression. GO and KEGG pathway enrichment analysis showed that DEGs were mostly involved in collagen fibril organization, extracellular matrix (ECM) structural constituent, bHLH transcription factor binding, AGE-RAGE signaling pathway and TGF-beta signaling pathway. Only 3 hub genes (DCN, JUN, THBS1) displayed significantly higher expression compared to those in the healthy controls. These hub genes were also strongly related to clinical stages as well as overall survival (OS) of BC patients.

CONCLUSIONS

Taken together, most of hub genes involved in the progression of BC were related to ECM and EMT. In addition, 3 hub genes (DCN, JUN, THBS1) were strongly related with clinical stages and OS of BC patients. This study can enhance our comprehension of the progression of NMIBC and identify novel potential targets for MIBC.

The CD47/TSP-1 axis: a promising avenue for ovarian cancer treatment and biomarker research

BACKGROUND

Ovarian cancer (OC) remains one of the most challenging and deadly malignancies facing women today. While PARP inhibitors (PARPis) have transformed the treatment landscape for women with advanced OC, many patients will relapse and the PARPi-resistant setting is an area of unmet medical need. Traditional immunotherapies targeting PD-1/PD-L1 have failed to show any benefit in OC. The CD47/TSP-1 axis may be relevant in OC. We aimed to describe changes in CD47 expression with platinum therapy and their relationship with immune features and prognosis.

METHODS

Tumor and blood samples collected from OC patients in the CHIVA trial were assessed for CD47 and TSP-1 before and after neoadjuvant chemotherapy (NACT) and multiplex analysis was used to investigate immune markers. Considering the therapeutic relevance of targeting the CD47/TSP-1 axis, we used the CD47-derived TAX2 peptide to selectively antagonize it in a preclinical model of aggressive ovarian carcinoma.

RESULTS

Significant reductions in CD47 expression were observed post NACT. Tumor patients having the highest CD47 expression profile at baseline showed the greatest CD4+ and CD8+ T-cell influx post NACT and displayed a better prognosis. In addition, TSP-1 plasma levels decreased significantly under NACT, and high TSP-1 was associated with a worse prognosis. We demonstrated that TAX2 exhibited a selective and favorable biodistribution profile in mice, localizing at the tumor sites. Using a relevant peritoneal carcinomatosis model displaying PARPi resistance, we demonstrated that post-olaparib (post-PARPi) administration of TAX2 significantly reduced tumor burden and prolonged survival. Remarkably, TAX2 used sequentially was also able to increase animal survival even under treatment conditions allowing olaparib efficacy.

CONCLUSIONS

Our study thus (1) proposes a CD47-based stratification of patients who may be most likely to benefit from postoperative immunotherapy, and (2) suggests that TAX2 is a potential alternative therapy for patients relapsing on PARP inhibitors.

The impact of platelets on the metastatic potential of tumour cells

In cancer, activation of platelets by tumor cells is critical to disease progression. Development of precise antiplatelet targeting may improve outcomes from anticancer therapy. Alongside a distinct shift in functionality such as pro-metastatic and pro-coagulant properties, platelet production is often accelerated significantly early in carcinogenesis and the cancer-associated thrombocytosis increases the risk of metastasis formation and thromboembolic events. Tumor-activated platelets facilitate the proliferation of migrating tumor cells and shield them from immune surveillance and physical stress during circulation. Additionally, platelet-tumor cell interactions promote tumor cell intravasation, intravascular arrest, and extravasation through a repertoire of adhesion molecules, growth factors and angiogenic factors. Particularly, the presence of circulating tumor cell (CTC) clusters in association with platelets is a negative prognostic indicator. The contribution of platelets to the metastatic process is an area of intense investigation and this review provides an overview of the advances in understanding platelet-tumor cell interactions and their contribution to disease progression. Also, we review the potential of targeting platelets to interfere with the metastatic process.

Phagocytosis Checkpoints in Glioblastoma: CD47 and Beyond

Glioblastoma multiforme (GBM) is one of the deadliest human cancers with very limited treatment options available. The malignant behavior of GBM is manifested in a tumor which is highly invasive, resistant to standard cytotoxic chemotherapy, and strongly immunosuppressive. Immune checkpoint inhibitors have recently been introduced in the clinic and have yielded promising results in certain cancers. GBM, however, is largely refractory to these treatments. The immune checkpoint CD47 has recently gained attention as a potential target for intervention as it conveys a "don't eat me" signal to tumor-associated macrophages (TAMs) via the inhibitory SIRP alpha protein. In preclinical models, the administration of anti-CD47 monoclonal antibodies has shown impressive results with GBM and other tumor models. Several well-characterized oncogenic pathways have recently been shown to regulate CD47 expression in GBM cells and glioma stem cells (GSCs) including Epidermal Growth Factor Receptor (EGFR) beta catenin. Other macrophage pathways involved in regulating phagocytosis including TREM2 and glycan binding proteins are discussed as well. Finally, chimeric antigen receptor macrophages (CAR-Ms) could be leveraged for greatly enhancing the phagocytosis of GBM and repolarization of the microenvironment in general. Here, we comprehensively review the mechanisms that regulate the macrophage phagocytosis of GBM cells.

A Synopsis of Biomarkers in Glioblastoma: Past and Present

Accounting for 48% of malignant brain tumors in adults, glioblastoma has been of great interest in the last decades, especially in the biomolecular and neurosurgical fields, due to its incurable nature and notable neurological morbidity. The major advancements in neurosurgical technologies have positively influenced the extent of safe tumoral resection, while the latest progress in the biomolecular field of GBM has uncovered new potential therapeutical targets. Although GBM currently has no curative therapy, recent progress has been made in the management of this disease, both from surgical and molecular perspectives. The main current therapeutic approach is multimodal and consists of neurosurgical intervention, radiotherapy, and chemotherapy, mostly with temozolomide. Although most patients will develop treatment resistance and tumor recurrence after surgical removal, biomolecular advancements regarding GBM have contributed to a better understanding of this pathology and its therapeutic management. Over the past few decades, specific biomarkers have been discovered that have helped predict prognosis and treatment responses and contributed to improvements in survival rates.

Generation of glioblastoma in mice engrafted with human cytomegalovirus-infected astrocytes

Mounting evidence is identifying human cytomegalovirus (HCMV) as a potential oncogenic virus. HCMV has been detected in glioblastoma multiforme (GB). Herewith, we present the first experimental evidence for the generation of CMV-Elicited Glioblastoma Cells (CEGBCs) possessing glioblastoma-like traits that lead to the formation of glioblastoma in orthotopically xenografted mice. In addition to the already reported oncogenic HCMV-DB strain, we isolated three HCMV clinical strains from GB tissues that transformed HAs toward CEGBCs and generated spheroids from CEGBCs that resulted in the appearance of glioblastoma-like tumors in xenografted mice. These tumors were nestin-positive mostly in the invasive part surrounded by GFAP-positive reactive astrocytes. The glioblastoma immunohistochemistry phenotype was confirmed by EGFR and cMet gene amplification in the tumor parallel to the detection of HCMV IE and UL69 genes and proteins. Our results fit with an HCMV-induced glioblastoma model of oncogenesis in vivo which will open the door to new therapeutic approaches and assess the anti-HCMV treatment as well as immunotherapy in fighting GB which is characterized by poor prognosis.

IKIP downregulates THBS1/FAK signaling to suppress migration and invasion by glioblastoma cells

Background

Inhibitor of NF-κB kinase-interacting protein (IKIP) is known to promote proliferation of glioblastoma (GBM) cells, but how it affects migration and invasion by those cells is unclear.

Methods

We compared levels of IKIP between glioma tissues and normal brain tissue in clinical samples and public databases. We examined the effects of IKIP overexpression and knockdown on the migration and invasion of GBM using transwell and wound healing assays, and we compared the transcriptomes under these different conditions to identify the molecular mechanisms involved.

Results

Based on data from our clinical samples and from public databases, IKIP was overexpressed in GBM tumors, and its expression level correlated inversely with survival. IKIP overexpression in GBM cells inhibited migration and invasion in transwell and wound healing assays, whereas IKIP knockdown exerted the opposite effects. IKIP overexpression in GBM cells that were injected into mouse brain promoted tumor growth but inhibited tumor invasion of surrounding tissue. The effects of IKIP were associated with downregulation of THBS1 mRNA and concomitant inhibition of THBS1/FAK signaling.

Conclusions

IKIP inhibits THBS1/FAK signaling to suppress migration and invasion of GBM cells.

Involvement of Matricellular Proteins in Cellular Senescence: Potential Therapeutic Targets for Age-Related Diseases

Senescence is a physiological and pathological cellular program triggered by various types of cellular stress. Senescent cells exhibit multiple characteristic changes. Among them, the characteristic flattened and enlarged morphology exhibited in senescent cells is observed regardless of the stimuli causing the senescence. Several studies have provided important insights into pro-adhesive properties of cellular senescence, suggesting that cell adhesion to the extracellular matrix (ECM), which is involved in characteristic morphological changes, may play pivotal roles in cellular senescence. Matricellular proteins, a group of structurally unrelated ECM molecules that are secreted into the extracellular environment, have the unique ability to control cell adhesion to the ECM by binding to cell adhesion receptors, including integrins. Recent reports have certified that matricellular proteins are closely involved in cellular senescence. Through this biological function, matricellular proteins are thought to play important roles in the pathogenesis of age-related diseases, including fibrosis, osteoarthritis, intervertebral disc degeneration, atherosclerosis, and cancer. This review outlines recent studies on the role of matricellular proteins in inducing cellular senescence. We highlight the role of integrin-mediated signaling in inducing cellular senescence and provide new therapeutic options for age-related diseases targeting matricellular proteins and integrins.

Dissecting TGF-β-induced glioblastoma invasion with engineered hyaluronic acid hydrogels

Glioma stem cells (GSCs) contribute to rapid cellular invasion in glioblastoma (GBM). Transforming growth factor-β (TGF-β) has been strongly implicated in supporting key GSC functions, including stemness, immunosuppression, and resistance. Although TGF-β is well-known as a driver of cancer invasion, how TGF-β supports the invasion of GSCs is not well understood. Progress in understanding mechanisms of TGF-β-driven invasion in GSC-derived tumors has been limited by an absence of three-dimensional (3D) culture systems that support TGF-β-stimulated invasion. Here, we show that 3D hyaluronic acid (HA) matrices can address this need. We perform bioinformatic analysis of human glioma datasets, which reveals progressive enrichment of TGF-β-related gene expression with increasingly aggressive glioma grade and GBM subtype. We then experimentally screen the invasion of a panel of human GSC spheroids through a set of 3D matrix systems, including collagen I, Matrigel, and HA, and find that only HA recapitulates TGF-β-induced invasion. We then show that GSCs differ in their ability to invade HA in a way that can be predicted from TGF-β receptor 2 expression and SMAD2 phosphorylation. GSC spheroid invasion depends strongly on the presence of RGD peptides on the HA backbone but is surprisingly independent of matrix metalloprotease degradability. Finally, we demonstrate that TGF-β stimulates invasion through SMAD-dependent signaling, consistent with recent observations that TGF-β/SMAD signals drive tumor microtube formation and invasion. Our work supports further development of HA as a matrix platform for dissecting contributions of TGF-β and other cytokines to GBM invasion and screening of cytokine-dependent invasion in human tumors.

Positive and negative feedback regulation of the TGF-β1 explains two equilibrium states in skin aging

During aging, skin homeostasis is essential for maintaining appearance, as well as biological defense of the human body. In this study, we identified thrombospondin-1 (THBS1) and fibromodulin (FMOD) as positive and negative regulators, respectively, of the TGF-β1-SMAD4 axis in human skin aging, based on in vitro and in vivo omics analyses and mathematical modeling. Using transcriptomic and epigenetic analyses of senescent dermal fibroblasts, TGF-β1 was identified as the key upstream regulator. Bifurcation analysis revealed a binary high-/low-TGF-β1 switch, with THBS1 as the main controller. Computational simulation of the TGF-β1 signaling pathway indicated that THBS1 expression was sensitively regulated, whereas FMOD was regulated robustly. Results of sensitivity analysis and validation showed that inhibition of SMAD4 complex formation was a promising method to control THBS1 production and senescence. Therefore, this study demonstrated the potential of combining data-driven target discovery with mathematical approaches to determine the mechanisms underlying skin aging.

Vessel co-option: a unique vascular-immune niche in liver cancer

Tumor vasculature is pivotal in regulating tumor perfusion, immune cell infiltration, metastasis, and invasion. The vascular status of the tumor is intricately linked to its immune landscape and response to immunotherapy. Vessel co-option means that tumor tissue adeptly exploits pre-existing blood vessels in the para-carcinoma region to foster its growth rather than inducing angiogenesis. It emerges as a significant mechanism contributing to anti-angiogenic therapy resistance. Different from angiogenic tumors, vessel co-option presents a distinctive vascular-immune niche characterized by varying states and distribution of immune cells, including T-cells, tumor-associated macrophages, neutrophils, and hepatic stellate cells. This unique composition contributes to an immunosuppressive tumor microenvironment that is crucial in modulating the response to cancer immunotherapy. In this review, we systematically reviewed the evidence and molecular mechanisms of vessel co-option in liver cancer, while also exploring its implications for anti-angiogenic drug resistance and the immune microenvironment, to provide new ideas and clues for screening patients with liver cancer who are effective in immunotherapy.

SUMOylation controls Hu antigen R posttranscriptional activity in liver cancer

The posttranslational modification of proteins critically influences many biological processes and is a key mechanism that regulates the function of the RNA-binding protein Hu antigen R (HuR), a hub in liver cancer. Here, we show that HuR is SUMOylated in the tumor sections of patients with hepatocellular carcinoma in contrast to the surrounding tissue, as well as in human cell line and mouse models of the disease. SUMOylation of HuR promotes major cancer hallmarks, namely proliferation and invasion, whereas the absence of HuR SUMOylation results in a senescent phenotype with dysfunctional mitochondria and endoplasmic reticulum. Mechanistically, SUMOylation induces a structural rearrangement of the RNA recognition motifs that modulates HuR binding affinity to its target RNAs, further modifying the transcriptomic profile toward hepatic tumor progression. Overall, SUMOylation constitutes a mechanism of HuR regulation that could be potentially exploited as a therapeutic strategy for liver cancer.

Role of thrombospondin-1 in high-salt-induced mesenteric artery endothelial impairment in rats

The matrix glycoprotein thrombospondin-1 (THBS1) modulates nitric oxide (NO) signaling in endothelial cells. A high-salt diet induces deficiencies of NO production and bioavailability, thereby leading to endothelial dysfunction. In this study we investigated the changes of THBS1 expression and its pathological role in the dysfunction of mesenteric artery endothelial cells (MAECs) induced by a high-salt diet. Wild-type rats, and wild-type and Thbs1-/- mice were fed chow containing 8% w/w NaCl for 4 weeks. We showed that a high salt diet significantly increased THBS1 expression and secretion in plasma and MAECs, and damaged endothelium-dependent vasodilation of mesenteric resistance arteries in wild-type animals, but not in Thbs1-/- mice. In rat MAECs, we demonstrated that a high salt environment (10-40 mM) dose-dependently increased THBS1 expression accompanied by suppressed endothelial nitric oxide synthase (eNOS) and phospho-eNOS S1177 production as well as NO release. Blockade of transforming growth factor-β1 (TGF-β1) activity by a TGF-β1 inhibitor SB 431542 reversed THBS1 up-regulation, rescued the eNOS decrease, enhanced phospho-eNOS S1177 expression, and inhibited Smad4 translocation to the nucleus. By conducting dual-luciferase reporter experiments in HEK293T cells, we demonstrated that Smad4, a transcription promoter, upregulated Thbs1 transcription. We conclude that THBS1 contributes to endothelial dysfunction in a high-salt environment and may be a potential target for treatment of high-salt-induced endothelium dysfunction.

New insights into the role of thrombospondin-1 in glioblastoma development

Glioblastoma (GB), the most malignant subtype of diffuse glioma, is highly aggressive, invasive and vascularized. Its median survival is still short even with maximum standard care. There is a need to identify potential new molecules and mechanisms, that are involved in the interactions of GB cells with the tumor microenvironment (TME), for therapeutic intervention. Thrombospondin-1 (TSP1) is a multi-faceted matricellular protein which plays a significant role in development, physiology and pathology including cancer. Recent studies have pinpoint an important role of TSP1 in GB development which will be summarized and discussed herein. We will discuss studies, mainly from preclinical research, which should lead to a deeper understanding of TSP1's role in GB development. We will also discuss some issues with regard to the use of this knowledge for the clinic.

THBS1 promotes angiogenesis and accelerates ESCC malignant progression by the HIF-1/VEGF signaling pathway

Previously, we demonstrated that the expression of THBS1 is increased in esophageal squamous cell carcinoma (ESCC) tissues and is correlated with lymph node metastasis and poor prognosis, indicating that THBS1 might be a candidate oncogene in ESCC. In this study, we future studied the specific role of THBS1 in ESCC and its molecular mechanism. Silencing THBS1 expression resulted in inhibition of cell migration and cell invasion of ESCC cells, the decrease of colony formation and proliferation. Tube formation of human umbilical vein endothelial cells (HUVECs) in vitro was decreased when cultured with conditioned medium from THBS1-silenced cells. The expression of CD31, a marker for blood vessel endothelial cells, was decreased in tumor tissues derived from THBS1-silenced tumors in vivo. Silencing THBS1 leaded the decreased of hypoxia-inducible factor-1α (HIF-1α), HIF-1β, and VEGFA protein. The expression of p-ERK and p-AKT were declined in HUVECs following incubation with conditioned medium from THBS1-silenced ESCC cells compared conditioned medium from control cells. Furthermore, the treatment with bevacizumab boosted the decrease of the p-ERK and p-AKT levels in HUVECs incubated with the conditioned medium from THBS1-silenced ESCC cells. THBS1 silencing combined with bevacizumab blocked VEGF, inhibited to the tube formation, colony formation and migration of HUVECs, which were superior to that of bevacizumab alone. We presumed that THBS1 can enhance HIF-1/VEGF signaling and subsequently induce angiogenesis by activating the AKT and ERK pathways in HUVECs, resulting in bevacizumab resistance. THBS1 would be a potential target in tumor antiangiogenesis therapies.

Stromal thrombospondin 1 suppresses angiogenesis in oral submucous fibrosis

A decline in mucosal vascularity is a histological hallmark of oral submucous fibrosis (OSF), a premalignant disease that is largely induced by betel quid chewing. However, the lack of available models has challenged studies of angiogenesis in OSF. Here, we found that the expression of thrombospondin 1 (THBS1), an endogenous angiostatic protein, was elevated in the stroma of tissues with OSF. Using a fibroblast-attached organoid (FAO) model, the overexpression of THBS1 in OSF was stably recapitulated in vitro. In the FAO model, treatment with arecoline, a major pathogenic component in areca nuts, enhanced the secretion of transforming growth factor (TGF)-β1 by epithelial cells, which then promoted the expression of THBS1 in fibroblasts. Furthermore, human umbilical vein endothelial cells (HUVECs) were incorporated into the FAO to mimic the vascularized component. Overexpression of THBS1 in fibroblasts drastically suppressed the sprouting ability of endothelial cells in vascularized FAOs (vFAOs). Consistently, treatment with arecoline reduced the expression of CD31 in vFAOs, and this effect was attenuated when the endothelial cells were preincubated with neutralizing antibody of CD36, a receptor of THBS1. Finally, in an arecoline-induced rat OSF model, THBS1 inhibition alleviated collagen deposition and the decline in vascularity in vivo. Overall, we exploited an assembled organoid model to study OSF pathogenesis and provide a rationale for targeting THBS1.

Predictive potentials of glycosylation-related genes in glioma prognosis and their correlation with immune infiltration

Glycosylation is currently considered to be an important hallmark of cancer. However, the characterization of glycosylation-related gene sets has not been comprehensively analyzed in glioma, and the relationship between glycosylation-related genes and glioma prognosis has not been elucidated. Here, we firstly found that the glycosylation-related differentially expressed genes in glioma patients were engaged in biological functions related to glioma progression revealed by enrichment analysis. Then seven glycosylation genes (BGN, C1GALT1C1L, GALNT13, SDC1, SERPINA1, SPTBN5 and TUBA1C) associated with glioma prognosis were screened out by consensus clustering, principal component analysis, Lasso regression, and univariate and multivariate Cox regression analysis using the TCGA-GTEx database. A glycosylation-related prognostic signature was developed and validated using CGGA database data with significantly accurate prediction on glioma prognosis, which showed better capacity to predict the prognosis of glioma patients than clinicopathological factors do. GSEA enrichment analysis based on the risk score further revealed that patients in the high-risk group were involved in immune-related pathways such as cytokine signaling, inflammatory responses, and immune regulation, as well as glycan synthesis and metabolic function. Immuno-correlation analysis revealed that a variety of immune cell infiltrations, such as Macrophage, activated dendritic cell, Regulatory T cell (Treg), and Natural killer cell, were increased in the high-risk group. Moreover, functional experiments were performed to evaluate the roles of risk genes in the cell viability and cell number of glioma U87 and U251 cells, which demonstrated that silencing BGN, SDC1, SERPINA1, TUBA1C, C1GALT1C1L and SPTBN5 could inhibit the growth and viability of glioma cells. These findings strengthened the prognostic potentials of our predictive signature in glioma. In conclusion, this prognostic model composed of 7 glycosylation-related genes distinguishes well the high-risk glioma patients, which might potentially serve as caner biomarkers for disease diagnosis and treatment.

Biochemical and cellular insights into the Baz2B protein, a non-catalytic subunit of the chromatin remodeling complex

Baz2B is a regulatory subunit of the ATP-dependent chromatin remodeling complexes BRF1 and BRF5, which control access to DNA during DNA-templated processes. Baz2B has been implicated in several diseases and also in unhealthy ageing, however limited information is available on the domains and cellular roles of Baz2B. To gain more insight into the Baz2B function, we biochemically characterized the TAM (Tip5/ARBP/MBD) domain with the auxiliary AT-hook motifs and the bromodomain (BRD). We observed alterations in histone code recognition in bromodomains carrying cancer-associated point mutations, suggesting their potential involvement in disease. Furthermore, the depletion of Baz2B in the Hap1 cell line resulted in altered cell morphology, reduced colony formation and perturbed transcriptional profiles. Despite that, super-resolution microscopy images revealed no changes in the overall chromatin structure in the absence of Baz2B. These findings provide insights into the biological function of Baz2B.

LncRNA MIR217HG aggravates pressure-overload induced cardiac remodeling by activating miR-138/THBS1 pathway

AIM

Cardiac hypertrophy and fibrosis are associated with cardiac remodeling and heart failure. We have previously shown that miRNA-217, embedded within the third intron of MIR217HG, aggravates pressure overload-induced cardiac hypertrophy by targeting phosphatase and tensin homolog. However, whether the MIR217HG transcript itself plays a role in cardiac remodeling remains unknown.

METHODS

Real-time PCR assays and RNA in situ hybridization were performed to detect MIR217HG expression. Lentiviruses and adeno-associated viruses with a cardiac-specific promoter (cTnT) were used to control MIR217HG expression in vitro and in vivo. Transverse aortic constriction (TAC) surgery was performed to develop cardiac remodeling models. Cardiac structure and function were analyzed using echocardiography and invasive pressure-volume analysis.

KEY FINDINGS

MIR217HG expression was increased in patients with heart failure. MIR217HG overexpression aggravated pressure-overload-induced myocyte hypertrophy and fibrosis both in vivo and in vitro, whereas MIR217HG knockdown reversed these phenotypes. Mechanistically, MIR217HG increased THBS1 expression by sponging miR-138. MiR-138 recognized the 3'UTR of THBS1 and repressed THBS1 expression in the absence of MIR217HG. Silencing THBS1 expression reversed MIR217HG-induced cardiac hypertrophy and remodeling.

CONCLUSION

MIR217HG acts as a potent inducer of cardiac remodeling that may contribute to heart failure by activating the miR-138/THBS1 pathway.

Gα12 signaling regulates transcriptional and phenotypic responses that promote glioblastoma tumor invasion

In silico interrogation of glioblastoma (GBM) in The Cancer Genome Atlas (TCGA) revealed upregulation of GNA12 (Gα12), encoding the alpha subunit of the heterotrimeric G-protein G12, concomitant with overexpression of multiple G-protein coupled receptors (GPCRs) that signal through Gα12. Glioma stem cell lines from patient-derived xenografts also showed elevated levels of Gα12. Knockdown (KD) of Gα12 was carried out in two different human GBM stem cell (GSC) lines. Tumors generated in vivo by orthotopic injection of Gα12KD GSC cells showed reduced invasiveness, without apparent changes in tumor size or survival relative to control GSC tumor-bearing mice. Transcriptional profiling of GSC-23 cell tumors revealed significant differences between WT and Gα12KD tumors including reduced expression of genes associated with the extracellular matrix, as well as decreased expression of stem cell genes and increased expression of several proneural genes. Thrombospondin-1 (THBS1), one of the genes most repressed by Gα12 knockdown, was shown to be required for Gα12-mediated cell migration in vitro and for in vivo tumor invasion. Chemogenetic activation of GSC-23 cells harboring a Gα12-coupled DREADD also increased THBS1 expression and in vitro invasion. Collectively, our findings implicate Gα12 signaling in regulation of transcriptional reprogramming that promotes invasiveness, highlighting this as a potential signaling node for therapeutic intervention.

Deep learning untangles the resistance mechanism of p53 reactivator in lung cancer cells

Tumor suppressor p53 plays a pivotal role in suppressing cancer, so various drugs has been suggested to upregulate its function. However, drug resistance is still the biggest hurdle to be overcome. To address this, we developed a deep learning model called AnoDAN (anomalous gene detection using generative adversarial networks and graph neural networks for overcoming drug resistance) that unravels the hidden resistance mechanisms and identifies a combinatorial target to overcome the resistance. Our findings reveal that the TGF-β signaling pathway, alongside the p53 signaling pathway, mediates the resistance, with THBS1 serving as a core regulatory target in both pathways. Experimental validation in lung cancer cells confirms the effects of THBS1 on responsiveness to a p53 reactivator. We further discovered the positive feedback loop between THBS1 and the TGF-β pathway as the main source of resistance. This study enhances our understanding of p53 regulation and offers insights into overcoming drug resistance.

Inhibition of the membrane repair protein annexin-A2 prevents tumor invasion and metastasis

Cancer cells are exposed to major compressive and shearing forces during invasion and metastasis, leading to extensive plasma membrane damage. To survive this mechanical stress, they need to repair membrane injury efficiently. Targeting the membrane repair machinery is thus potentially a new way to prevent invasion and metastasis. We show here that annexin-A2 (ANXA2) is required for membrane repair in invasive breast and pancreatic cancer cells. Mechanistically, we show by fluorescence and electron microscopy that cells fail to reseal shear-stress damaged membrane when ANXA2 is silenced or the protein is inhibited with neutralizing antibody. Silencing of ANXA2 has no effect on proliferation in vitro, and may even accelerate migration in wound healing assays, but reduces tumor cell dissemination in both mice and zebrafish. We expect that inhibiting membrane repair will be particularly effective in aggressive, poor prognosis tumors because they rely on the membrane repair machinery to survive membrane damage during tumor invasion and metastasis. This could be achieved either with anti-ANXA2 antibodies, which have been shown to inhibit metastasis of breast and pancreatic cancer cells, or with small molecule drugs.

Integrin-αvβ3 is a Therapeutically Targetable Fundamental Factor in Medulloblastoma Tumorigenicity and Radioresistance

Medulloblastoma is one of the most prevalent solid tumors found in children, occurring in the brain's posterior fossa. The standard treatment protocol involves maximal resection surgery followed by craniospinal irradiation and chemotherapy. Despite a long-term survival rate of 70%, wide disparities among patients have been observed. The identification of pertinent targets for both initial and recurrent medulloblastoma cases is imperative. Both primary and recurrent medulloblastoma are marked by their aggressive infiltration into surrounding brain tissue, robust angiogenesis, and resistance to radiotherapy. While the significant role of integrin-αvβ3 in driving these characteristics has been extensively documented in glioblastoma, its impact in the context of medulloblastoma remains largely unexplored. Integrin-αvβ3 was found to be expressed in a subset of patients with medulloblastoma. We investigated the role of integrin-αvβ3 using medulloblastoma-derived cell lines with β3-subunit depletion or overexpression both in vitro and in vivo settings. By generating radioresistant medulloblastoma cell lines, we uncovered an increased integrin-αvβ3 expression, which correlated with increased susceptibility to pharmacologic integrin-αvβ3 inhibition with cilengitide, a competitive ligand mimetic. Finally, we conducted single-photon emission computed tomography (SPECT)/MRI studies on orthotopic models using a radiolabeled integrin-αvβ3 ligand (99mTc-RAFT-RGD). This innovative approach presents the potential for a novel predictive imaging technique in the realm of medulloblastoma. Altogether, our findings lay the foundation for employing SPECT/MRI to identify a specific subset of patients with medulloblastoma eligible for integrin-αvβ3-directed therapies. This breakthrough offers a pathway toward more targeted and effective interventions in the treatment of medulloblastoma.

SIGNIFICANCE

This study demonstrates integrin-αvβ3's fundamental role in medulloblastoma tumorigenicity and radioresistance and the effect of its expression on cilengitide functional activity.

Ligand-dependent CD36 functions in cancer progression, metastasis, immune response, and drug resistance

CD36, a multifunctional glycoprotein, has been shown to play critical roles in tumor initiation, progression, metastasis, immune response, and drug resistance. CD36 serves as a receptor for a wide range of ligands, including lipid-related ligands (e.g., long-chain fatty acid (LCFA), oxidized low-density lipoprotein (oxLDL), and oxidized phospholipids), as well as protein-related ligands (e.g., thrombospondins, amyloid proteins, collagens I and IV). CD36 is overexpressed in various cancers and may act as an independent prognostic marker. While it was initially identified as a mediator of anti-angiogenesis through its interaction with thrombospondin-1 (TSP1), recent research has highlighted its role in promoting tumor growth, metastasis, drug resistance, and immune suppression. The varied impact of CD36 on cancer is likely ligand-dependent. Therefore, we focus specifically on the ligand-dependent role of CD36 in cancer to provide a critical review of recent advances, perspectives, and challenges.

Single-Cell RNA Sequencing Reveals That Adaptation of Human Aortic Endothelial Cells to Antiproliferative Therapies Is Modulated by Flow-Induced Shear Stress

BACKGROUND

Endothelial cells (ECs) are capable of quickly responding in a coordinated manner to a wide array of stresses to maintain vascular homeostasis. Loss of EC cellular adaptation may be a potential marker for cardiovascular disease and a predictor of poor response to endovascular pharmacological interventions such as drug-eluting stents. Here, we report single-cell transcriptional profiling of ECs exposed to multiple stimulus classes to evaluate EC adaptation.

METHODS

Human aortic ECs were costimulated with both pathophysiological flows mimicking shear stress levels found in the human aorta (laminar and turbulent, ranging from 2.5 to 30 dynes/cm2) and clinically relevant antiproliferative drugs, namely paclitaxel and rapamycin. EC state in response to these stimuli was defined using single-cell RNA sequencing.

RESULTS

We identified differentially expressed genes and inferred the TF (transcription factor) landscape modulated by flow shear stress using single-cell RNA sequencing. These flow-sensitive markers differentiated previously identified spatially distinct subpopulations of ECs in the murine aorta. Moreover, distinct transcriptional modules defined flow- and drug-responsive EC adaptation singly and in combination. Flow shear stress was the dominant driver of EC state, altering their response to pharmacological therapies.

CONCLUSIONS

We showed that flow shear stress modulates the cellular capacity of ECs to respond to paclitaxel and rapamycin administration, suggesting that while responding to different flow patterns, ECs experience an impairment in their transcriptional adaptation to other stimuli.

Acquired temozolomide resistance instructs patterns of glioblastoma behavior in gelatin hydrogels

Acquired drug resistance in glioblastoma (GBM) presents a major clinical challenge and is a key factor contributing to abysmal prognosis, with less than 15 months median overall survival. Aggressive chemotherapy with the frontline therapeutic, temozolomide (TMZ), ultimately fails to kill residual highly invasive tumor cells after surgical resection and radiotherapy. Here, we report a three-dimensional (3D) engineered model of acquired TMZ resistance using two isogenically-matched sets of GBM cell lines encapsulated in gelatin methacrylol hydrogels. We benchmark response of TMZ-resistant vs. TMZ-sensitive GBM cell lines within the gelatin-based extracellular matrix platform and further validate drug response at physiologically relevant TMZ concentrations. We show changes in drug sensitivity, cell invasion, and matrix-remodeling cytokine production as the result of acquired TMZ resistance. This platform lays the foundation for future investigations targeting key elements of the GBM tumor microenvironment to combat GBM's devastating impact by advancing our understanding of GBM progression and treatment response to guide the development of novel treatment strategies.

Teaser

A hydrogel model to investigate the impact of acquired drug resistance on functional response in glioblastoma.

Multiomic screening of invasive GBM cells reveals targetable transsulfuration pathway alterations

While the poor prognosis of glioblastoma arises from the invasion of a subset of tumor cells, little is known of the metabolic alterations within these cells that fuel invasion. We integrated spatially addressable hydrogel biomaterial platforms, patient site-directed biopsies, and multiomics analyses to define metabolic drivers of invasive glioblastoma cells. Metabolomics and lipidomics revealed elevations in the redox buffers cystathionine, hexosylceramides, and glucosyl ceramides in the invasive front of both hydrogel-cultured tumors and patient site-directed biopsies, with immunofluorescence indicating elevated reactive oxygen species (ROS) markers in invasive cells. Transcriptomics confirmed upregulation of ROS-producing and response genes at the invasive front in both hydrogel models and patient tumors. Among oncologic ROS, H2O2 specifically promoted glioblastoma invasion in 3D hydrogel spheroid cultures. A CRISPR metabolic gene screen revealed cystathionine γ-lyase (CTH), which converts cystathionine to the nonessential amino acid cysteine in the transsulfuration pathway, to be essential for glioblastoma invasion. Correspondingly, supplementing CTH knockdown cells with exogenous cysteine rescued invasion. Pharmacologic CTH inhibition suppressed glioblastoma invasion, while CTH knockdown slowed glioblastoma invasion in vivo. Our studies highlight the importance of ROS metabolism in invasive glioblastoma cells and support further exploration of the transsulfuration pathway as a mechanistic and therapeutic target.

Gastric cancer derived exosomal THBS1 enhanced Vγ9Vδ2 T-cell function through activating RIG-I-like receptor signaling pathway in a N6-methyladenosine methylation dependent manner

Gamma delta (γδ) T-cell-based immunotherapy has shown favorable safety and clinical response in patients with multiple types of cancer. However, its efficiency in treating patients with solid tumors remains limited. In the current study, we investigated the function and molecular mechanism underlying gastric cancer (GC) cell-derived exosomal THBS1 in the regulation of Vγ9Vδ2 T cells. We found that GC cell-derived exosomal THBS1 markedly enhanced the cytotoxicity of Vγ9Vδ2 T cells against GC cells and the production of IFN-γ, TNF-α, perforin and granzyme B in vitro and elevated the killing effects of Vγ9Vδ2 T cells on GC cells in vivo. Mechanistically, exosomal THBS1 could regulate METTL3-or IGF2BP2-mediated m6A modification, further activating the RIG-I-like receptor signaling pathway in Vγ9Vδ2 T cells. Moreover, blocking the RIG-I-like receptor signaling pathway reversed the effects of exosomal THBS1 on the function of Vγ9Vδ2 T cells. In addition, THBS1 was expressed at low levels in GC tissues and was associated with an unfavorable prognosis in GC patients. In sum, our findings indicate that exosomal THBS1 derived from GC cells enhanced the function of Vγ9Vδ2 T cells by activating the RIG-I-like signaling pathway in a m6A methylation-dependent manner. Targeting the exosomal THBS1/m6A/RIG-I axis may have important implications for GC immunotherapy based on Vγ9Vδ2 T cells.

Shadow imaging for panoptical visualization of brain tissue in vivo

Progress in neuroscience research hinges on technical advances in visualizing living brain tissue with high fidelity and facility. Current neuroanatomical imaging approaches either require tissue fixation (electron microscopy), do not have cellular resolution (magnetic resonance imaging) or only give a fragmented view (fluorescence microscopy). Here, we show how regular light microscopy together with fluorescence labeling of the interstitial fluid in the extracellular space provide comprehensive optical access in real-time to the anatomical complexity and dynamics of living brain tissue at submicron scale. Using several common fluorescence microscopy modalities (confocal, light-sheet and 2-photon microscopy) in mouse organotypic and acute brain slices and the intact mouse brain in vivo, we demonstrate the value of this straightforward 'shadow imaging' approach by revealing neurons, microglia, tumor cells and blood capillaries together with their complete anatomical tissue contexts. In addition, we provide quantifications of perivascular spaces and the volume fraction of the extracellular space of brain tissue in vivo.

Invadopodia associated Thrombospondin-1 contributes to a post-therapy pro-invasive response in glioblastoma cells

A critical challenge in the treatment of glioblastoma (GBM) is its highly invasive nature which promotes cell migration throughout the brain and hinders surgical resection and effective drug delivery. GBM cells demonstrate augmented invasive capabilities following exposure to the current gold standard treatment of radiotherapy (RT) and concomitant and adjuvant temozolomide (TMZ), resulting in rapid disease recurrence. Elucidating the mechanisms employed by post-treatment invasive GBM cells is critical to the development of more effective therapies. In this study, we utilized a Nanostring® Cancer Progression gene expression panel to identify candidate genes that may be involved in enhanced GBM cell invasion after treatment with clinically relevant doses of RT/TMZ. Our findings identified thrombospondin-1 (THBS1) as a pro-invasive gene that is upregulated in these cells. Immunofluorescence staining revealed that THBS1 localised within functional matrix-degrading invadopodia that formed on the surface of GBM cells. Furthermore, overexpression of THBS1 resulted in enhanced GBM cell migration and secretion of MMP-2, which was reduced with silencing of THBS1. The preliminary data demonstrates that THBS1 is associated with invadopodia in GBM cells and is likely involved in the invadopodia-mediated invasive process in GBM cells exposed to RT/TMZ treatment. Therapeutic inhibition of THBS1-mediated invadopodia activity, which facilitates GBM cell invasion, should be further investigated as a treatment for GBM.