Glycosylation in the Tumor Microenvironment: Implications for Tumor Angiogenesis and Metastasis

Exosomal AFAP1-AS1 Promotes the Growth, Metastasis, and Glycolysis of Pituitary Adenoma by Inhibiting HuR Degradation

Exosomal long noncoding RNAs (lncRNAs), which are highly expressed in tumor-derived exosomes, regulate various cellular behaviors such as cell proliferation, metastasis, and glycolysis by facilitating intercellular communication. Here, we explored the role and regulatory mechanism of tumor-derived exosomal lncRNAs in pituitary adenomas (PA). We isolated exosomes from PA cells, and performed in vitro and in vivo assays to examine their effect on the proliferation, metastasis, and glycolysis of PA cells. In addition, we conducted RNA pull-down, RNA immunoprecipitation, co-immunoprecipitation, and ubiquitination assays to investigate the downstream mechanism of exosomal AFAP1-AS1. Exosomes from PA cells augmented the proliferation, mobility, and glycolysis of PA cells. Moreover, AFAP1-AS1 was significantly enriched in these exosomes and stimulated the growth, migration, invasion, and glycolysis of PA cells in vitro, as well as tumor metastasis in vivo. It also enhanced the binding affinity between Hu antigen R (HuR) and SMAD-specific E3 ubiquitin protein ligase 1 (SMURF1), resulting in HuR ubiquitination and degradation accompanied by enhanced expression of hexokinase 2 (HK2) and pyruvate kinase M2 (PKM2). Moreover, HuR overexpression alleviated the exosomal AFAP1-AS1-mediated promotion of growth, metastasis, and glycolysis effects. These findings indicate that tumor-derived exosomal AFAP1-AS1 modulated SMURF1-mediated HuR ubiquitination and degradation to upregulate HK2 and PKM2 expression, thereby enhancing PA cell growth, metastasis, and glucose metabolism. This suggests targeting exosomal AFAP1-AS1 may be a potential strategy for the treatment of PA.

FUCA1: An Underexplored p53 Target Gene Linking Glycosylation and Cancer Progression

Cancer is a difficult-to-cure disease with high worldwide incidence and mortality, in large part due to drug resistance and disease relapse. Glycosylation, which is a common modification of cellular biomolecules, was discovered decades ago and has been of interest in cancer research due to its ability to influence cellular function and to promote carcinogenesis. A variety of glycosylation types and structures regulate the function of biomolecules and are potential targets for investigating and treating cancer. The link between glycosylation and carcinogenesis has been more recently revealed by the role of p53 in energy metabolism, including the p53 target gene alpha-L-fucosidase 1 (FUCA1), which plays an essential role in fucosylation. In this review, we summarize roles of glycan structures and glycosylation-related enzymes to cancer development. The interplay between glycosylation and tumor microenvironmental factors is also discussed, together with involvement of glycosylation in well-characterized cancer-promoting mechanisms, such as the epidermal growth factor receptor (EGFR), phosphatidylinositol-3-kinase/protein kinase B (PI3K/Akt) and p53-mediated pathways. Glycan structures also modulate cell-matrix interactions, cell-cell adhesion as well as cell migration and settlement, dysfunction of which can contribute to cancer. Thus, further investigation of the mechanistic relationships among glycosylation, related enzymes and cancer progression may provide insights into potential novel cancer treatments.

Lysine lactylation in the regulation of tumor biology

Lysine lactylation (Kla), a newly discovered post-translational modification (PTM) of lysine residues, is progressively revealing its crucial role in tumor biology. A growing body of evidence supports its capacity of transcriptional regulation through histone modification and modulation of non-histone protein function. It intricately participates in a myriad of events in the tumor microenvironment (TME) by orchestrating the transitions of immune states and augmenting tumor malignancy. Its preferential modification of metabolic proteins underscores its specific regulatory influence on metabolism. This review focuses on the effect and the probable mechanisms of Kla-mediated regulation of tumor metabolism, the upstream factors that determine Kla intensity, and its potential implications for the clinical diagnosis and treatment of tumors.

A Novel Signature Based on Angiogenesis-Related Genes Predicts the Prognosis and Immunotherapy Response in HER2-Positive Breast Cancer

Background: HER2-positive breast cancer is one of the most prevalent subtypes of breast cancer and represents a significant health concern for women worldwide due to its high morbidity and mortality rates. Recent studies have consistently underscored the pivotal role of angiogenesis in the development and progression of HER2-positive breast cancer. Here, we developed a prognostic signature based on angiogenesis-related genes (ARGs) to categorize HER2-positive breast cancer patients and provide insights into their survival outcomes. Methods: Kaplan-Meier survival curve, time-dependent receiver operating characteristic (ROC) and nomogram were performed to investigate the prognostic performance of the signature. In addition, we comprehensively analyzed the correlation of the prognostic signature with immune cell infiltration, immune checkpoint inhibitors (ICIs) therapy. Finally, Immunohistochemistry (IHC) and immunoblotting were used to investigate XBP1 expression in HER2-positive breast cancer tissues. Colony formation assay was performed to examine cell proliferation of HER2-positive breast cancer cells. Results: The Kaplan-Meier curves and the ROC curves demonstrated that the ARGs had good performance in predicting the prognosis of HER2-positive breast cancer patients. In addition, we observed that the low-risk group was remarkably associated with immune infiltration and better response to ICIs. Further experimental results show that XBP1 is upregulated in human HER2-positive breast cancer, and its knockdown significantly inhibited cell proliferation. Conclusions: Our study demonstrated that the ARGs could serve as a novel biomarker for predicting the prognosis of patients with HER2-positive breast cancer and providing new insights into immunotherapy strategies for these patients.

Cancer stem cells: advances in knowledge and implications for cancer therapy

Cancer stem cells (CSCs), a small subset of cells in tumors that are characterized by self-renewal and continuous proliferation, lead to tumorigenesis, metastasis, and maintain tumor heterogeneity. Cancer continues to be a significant global disease burden. In the past, surgery, radiotherapy, and chemotherapy were the main cancer treatments. The technology of cancer treatments continues to develop and advance, and the emergence of targeted therapy, and immunotherapy provides more options for patients to a certain extent. However, the limitations of efficacy and treatment resistance are still inevitable. Our review begins with a brief introduction of the historical discoveries, original hypotheses, and pathways that regulate CSCs, such as WNT/β-Catenin, hedgehog, Notch, NF-κB, JAK/STAT, TGF-β, PI3K/AKT, PPAR pathway, and their crosstalk. We focus on the role of CSCs in various therapeutic outcomes and resistance, including how the treatments affect the content of CSCs and the alteration of related molecules, CSCs-mediated therapeutic resistance, and the clinical value of targeting CSCs in patients with refractory, progressed or advanced tumors. In summary, CSCs affect therapeutic efficacy, and the treatment method of targeting CSCs is still difficult to determine. Clarifying regulatory mechanisms and targeting biomarkers of CSCs is currently the mainstream idea.

The role of endothelial junctions in the regulation of the extravasation of tumor cells. A historical reappraisal

Endothelial cells lining the vessel wall are connected by adherent, tight and gap junctions. Adherent junctions are common to all endothelial cells, whereas tight and gap junctions graduate within different vascular segments. Endothelial cell-cell junctions sustain vascular homeostasis and to control the transendothelial migration of inflammatory cells. Tumor cells need to weaken endothelial cell-cell junctions to penetrate the endothelial barrier and transendothelial migration and metastasis of tumor cells are tightly controlled by endothelial cell-cell junctions.

Tumor glucose metabolism and the T cell glycocalyx: implication for T cell function

The T cell is an immune cell subset highly effective in eliminating cancer cells. Cancer immunotherapy empowers T cells and occupies a solid position in cancer treatment. The response rate, however, remains relatively low (<30%). The efficacy of immunotherapy is highly dependent on T cell infiltration into the tumor microenvironment (TME) and the ability of these infiltrated T cells to sustain their function within the TME. A better understanding of the inhibitory impact of the TME on T cells is crucial to improve cancer immunotherapy. Tumor cells are well described for their switch into aerobic glycolysis (Warburg effect), resulting in high glucose consumption and a metabolically distinct TME. Conversely, glycosylation, a predominant posttranslational modification of proteins, also relies on glucose molecules. Proper glycosylation of T cell receptors influences the immunological synapse between T cells and tumor cells, thereby affecting T cell effector functions including their cytolytic and cytostatic activities. This review delves into the complex interplay between tumor glucose metabolism and the glycocalyx of T cells, shedding light on how the TME can induce alterations in the T cell glycocalyx, which can subsequently influence the T cell's ability to target and eliminate tumor cells.

Identification of prognostic models for glycosylation-related subtypes and tumor microenvironment infiltration characteristics in clear cell renal cell cancer

Background

One of the most fatal forms of cancer of the urinary system, renal cell carcinoma (RCC), significantly negatively impacts human health. Recent research reveals that abnormal glycosylation contributes to the growth and spread of tumors. However, there is no information on the function of genes related to glycosylation in RCC.

Methods

In this study, we created a technique that can be used to guide the choice of immunotherapy and chemotherapy regimens for RCC patients while predicting their survival prognosis. The Cancer Genome Atlas (TCGA) provided us with patient information, while the GeneCards database allowed us to collect genes involved in glycosylation. GSE29609 was used as external validation to assess the accuracy of prognostic models. The "ConsensusClusterPlus" program created molecular subtypes based on genes relevant to glycosylation discovered using differential expression analysis and univariate Cox analysis. We examined immune cell infiltration as measured by estimate, CIBERSORT, TIMER, and ssGSEA algorithms, Tumor Immune Dysfunction and Exclusion (TIDE) and exclusion of tumour stemness indices (TSIs) based on glycosylation-related molecular subtypes and risk profiles. Stratification, somatic mutation, nomogram creation, and chemotherapy response prediction were carried out based on risk factors.

Results

We built and verified 16 gene signatures associated with the prognosis of ccRCC patients, which are independent prognostic variables, and identified glycosylation-related genes by bioinformatics research. Cluster 2 is associated with lower human leukocyte antigen expression, worse overall survival, higher immunological checkpoints, and higher immune escape scores. In addition, cluster 2 had significantly better angiogenic activity, mesenchymal EMT, and stem ability scores. Higher immune checkpoint genes and human leukocyte antigens are associated with lower overall survival and a higher risk score. Higher estimated and immune scores, lesser tumor purity, lower mesenchymal EMT, and higher stem scores were all characteristics of the high-risk group. High amounts of tumor-infiltrating lymphocytes, a high mutation load, and a high copy number alteration frequency were present in the high-risk group.Discussion.According to our research, the 16-gene prognostic signature may be helpful in predicting prognosis and developing individualized treatments for patients with renal clear cell carcinoma, which may result in new personalized management options for these patients.

Aberrant tumor vasculature. Facts and pitfalls

Endothelial cells form a single cell layer lining the inner walls of blood vessels and play critical roles in organ homeostasis and disease progression. Specifically, tumor endothelial cells are heterogenous, and highly permeable, because of specific interactions with the tumor tissue environment and through soluble factors and cell-cell interactions. This review article aims to analyze different aspects of endothelial cell heterogeneity in tumor vasculature, with particular emphasis on vascular normalization, vascular permeability, metabolism, endothelial-to-mesenchymal transition, resistance to therapy, and the interplay between endothelial cells and the immune system.

Endothelial Slc35a1 Deficiency Causes Loss of LSEC Identity and Exacerbates Neonatal Lipid Deposition in the Liver in Mice

BACKGROUND & AIMS

The functional maturation of the liver largely occurs after birth. In the early stages of life, the liver of a newborn encounters enormous high-fat metabolic stress caused by the consumption of breast milk. It is unclear how the maturing liver adapts to high lipid metabolism. Liver sinusoidal endothelial cells (LSECs) play a fundamental role in establishing liver vasculature and are decorated with many glycoproteins on their surface. The Slc35a1 gene encodes a cytidine-5'-monophosphate (CMP)-sialic acid transporter responsible for transporting CMP-sialic acids between the cytoplasm and the Golgi apparatus for protein sialylation. This study aimed to determine whether endothelial sialylation plays a role in hepatic vasculogenesis and functional maturation.

METHODS

Endothelial-specific Slc35a1 knockout mice were generated. Liver tissues were collected for histologic analysis, lipidomic profiling, RNA sequencing, confocal immunofluorescence, and immunoblot analyses.

RESULTS

Endothelial Slc35a1-deficient mice exhibited excessive neonatal hepatic lipid deposition, severe liver damage, and high mortality. Endothelial deletion of Slc35a1 led to sinusoidal capillarization and disrupted hepatic zonation. Mechanistically, vascular endothelial growth factor receptor 2 (VEGFR2) in LSECs was desialylated and VEGFR2 signaling was enhanced in Slc35a1-deficient mice. Inhibition of VEGFR2 signaling by SU5416 alleviated lipid deposition and restored hepatic vasculature in Slc35a1-deficient mice.

CONCLUSIONS

Our findings suggest that sialylation of LSECs is critical for maintaining hepatic vascular development and lipid homeostasis. Targeting VEGFR2 signaling may be a new strategy to prevent liver disorders associated with abnormal vasculature and lipid deposition.

SETDB1-mediated CD147-K71 di-methylation promotes cell apoptosis in non-small cell lung cancer

Protein post-translational modifications (PTMs) are at the heart status of cellular signaling events and broadly involved in tumor progression. CD147 is a tumor biomarker with various PTMs, promoting tumor metastasis and metabolism reprogramming. Nevertheless, the relationship between the PTMs of CD147 and apoptosis has not been reported. In our study, we produced a specific anti-CD147-K71 di-methylation (CD147-K71me2) antibody by immunizing with a di-methylated peptide and observed that the level of CD147-K71me2 in non-small cell lung cancer (NSCLC) tissues were lower than that in NSCLC adjacent tissues. SETDB1 was identified as the methyltransferase catalyzing CD147 to generate CD147-K71me2. RNA-seq showed that FOSB was the most significant differentially expressed gene (DEG) between wild-type CD147 (CD147-WT) and K71-mutant CD147 (CD147-K71R) groups. Subsequently, we found that CD147-K71me2 promoted the expression of FOSB by enhancing the phosphorylation of p38, leading to tumor cell apoptosis. In vivo experiments showed that CD147-K71me2 significantly inhibited tumor progression by promoting cell apoptosis. Taken together, our findings indicate the inhibitory role of CD147-K71me2 in tumor progression from the perspective of post-translational modification, which is distinct from the pro-cancer function of CD147 itself, broadening our perspective on tumor-associated antigen CD147.

N-Glycosylation as a Modulator of Protein Conformation and Assembly in Disease

Glycosylation, a prevalent post-translational modification, plays a pivotal role in regulating intricate cellular processes by covalently attaching glycans to macromolecules. Dysregulated glycosylation is linked to a spectrum of diseases, encompassing cancer, neurodegenerative disorders, congenital disorders, infections, and inflammation. This review delves into the intricate interplay between glycosylation and protein conformation, with a specific focus on the profound impact of N-glycans on the selection of distinct protein conformations characterized by distinct interactomes-namely, protein assemblies-under normal and pathological conditions across various diseases. We begin by examining the spike protein of the SARS virus, illustrating how N-glycans regulate the infectivity of pathogenic agents. Subsequently, we utilize the prion protein and the chaperone glucose-regulated protein 94 as examples, exploring instances where N-glycosylation transforms physiological protein structures into disease-associated forms. Unraveling these connections provides valuable insights into potential therapeutic avenues and a deeper comprehension of the molecular intricacies that underlie disease conditions. This exploration of glycosylation's influence on protein conformation effectively bridges the gap between the glycome and disease, offering a comprehensive perspective on the therapeutic implications of targeting conformational mutants and their pathologic assemblies in various diseases. The goal is to unravel the nuances of these post-translational modifications, shedding light on how they contribute to the intricate interplay between protein conformation, assembly, and disease.

Endothelial cells in tumor microenvironment: insights and perspectives

The tumor microenvironment is a highly complex and dynamic mixture of cell types, including tumor, immune and endothelial cells (ECs), soluble factors (cytokines, chemokines, and growth factors), blood vessels and extracellular matrix. Within this complex network, ECs are not only relevant for controlling blood fluidity and permeability, and orchestrating tumor angiogenesis but also for regulating the antitumor immune response. Lining the luminal side of vessels, ECs check the passage of molecules into the tumor compartment, regulate cellular transmigration, and interact with both circulating pathogens and innate and adaptive immune cells. Thus, they represent a first-line defense system that participates in immune responses. Tumor-associated ECs are involved in T cell priming, activation, and proliferation by acting as semi-professional antigen presenting cells. Thus, targeting ECs may assist in improving antitumor immune cell functions. Moreover, tumor-associated ECs contribute to the development at the tumor site of tertiary lymphoid structures, which have recently been associated with enhanced response to immune checkpoint inhibitors (ICI). When compared to normal ECs, tumor-associated ECs are abnormal in terms of phenotype, genetic expression profile, and functions. They are characterized by high proliferative potential and the ability to activate immunosuppressive mechanisms that support tumor progression and metastatic dissemination. A complete phenotypic and functional characterization of tumor-associated ECs could be helpful to clarify their complex role within the tumor microenvironment and to identify EC specific drug targets to improve cancer therapy. The emerging therapeutic strategies based on the combination of anti-angiogenic treatments with immunotherapy strategies, including ICI, CAR T cells and bispecific antibodies aim to impact both ECs and immune cells to block angiogenesis and at the same time to increase recruitment and activation of effector cells within the tumor.

Downregulation of ST6GAL2 Correlates to Liver Inflammation and Predicts Adverse Prognosis in Hepatocellular Carcinoma

Purpose

ST6 Beta-Galactoside Alpha-2,6-Sialyltransferase 2 (ST6GAL2), a member of the sialic acid transferase family, is differentially expressed in diverse cancers. However, it remains poorly understood in tumorigenesis and impacts on immune cell infiltration (ICI) in hepatocellular carcinoma (HCC).

Patients and Methods

Herein, the expression, diagnosis, prognosis, functional enrichment, genetic alterations, immune characteristics, and targeted drugs of ST6GAL2 in HCC were researched by conducting bioinformatics analysis, in vivo, and in vitro experiments.

Results

ST6GAL2 was remarkably decreased in HCC compared to non-tumor tissues, portending a poor prognosis associated with high DNA methylation levels. Functional enrichment and GSVA analyses revealed that ST6GAL2 might function through the extracellular matrix, PI3K-Akt signaling pathways, and tumor inflammation signature. We found that ST6GAL2 expression was proportional to ICI, immunostimulator, and immune subtypes. ST6GAL2 expression first increased and then decreased during the progression of liver inflammation to HCC. The dysfunctional experiment indicated that ST6GAL2 might exert immunosuppressive effects during HCC progression through regulating ICI. Several broad-spectrum anticancer drugs were obtained by drug sensitivity prediction analysis of ST6GAL2.

Conclusion

In conclusion, ST6GAL2 was a reliable prognostic biomarker strongly associated with ICI, and could be a potential immunotherapeutic target for HCC.

Development and validation of glycosyltransferase related-gene for the diagnosis and prognosis of head and neck squamous cell carcinoma

BACKGROUND

Head and neck squamous cell carcinoma (HNSCC) is a highly heterogeneous cancer characterized by difficulties in early diagnosis and outcome prediction. Aberrant glycosylated structures produced by the aberrant expression of glycosyltransferases are prevalent in HNSCC. In this study, we aim to construct glycosyltransferase-related gene signatures with diagnostic and prognostic value to better stratify patients with HNSCC and improve their diagnosis and prognosis.

METHODS

Bioinformatic tools were used to process data of patients with HNSCC from The Cancer Genome Atlas (TCGA) database. The prognostic model was formatted using univariate and multivariate Cox regression methods, while the diagnostic signature was constructed using support vector machine (SVM) and LASSO analysis. The results were verified using the Gene Expression Omnibus (GEO) cohort. The tumor microenvironment and benefits of immune checkpoint inhibitor (ICI) therapy in subgroups defined by glycosyltransferase-related genes were analyzed. Molecular biology experiments, including western blotting, cell counting kit (CCK)-8, colony formation, wound healing, and Transwell assays, were conducted to confirm the oncogenic function of beta-1,4-galactosyltransferase 3 (B4GALT3) in HNSCC.

RESULTS

We established a five-gene prognostic signature and a 15-gene diagnostic model. Based on the median risk score, patients with low risk had longer overall survival than those in the high-risk group, which was consistent with the results of the GEO cohort. The concrete results suggested that high-risk samples were related to a high tumor protein (TP)53 mutation rate, high infiltration of resting memory cluster of differentiation (CD)4 T cells, resting natural killer (NK) cells, and M0 macrophages, and benefited from ICI therapy. In contrast, the low-risk subgroup was associated with a low TP53 mutation rate; and high infiltration of naive B cells, plasma cells, CD8 T cells, and resting mast cells; and benefited less from ICI therapy. In addition, the diagnostic model had an area under curve (AUC) value of 0.997 and 0.978 in the training dataset and validation cohort, respectively, indicating the high diagnostic potential of the model. Ultimately, the depletion of B4GALT3 significantly hindered the proliferation, migration, and invasion of HNSCC cells.

CONCLUSIONS

We established two new biomarkers that could provide clinicians with diagnostic, prognostic, and treatment guidance for patients with HNSCC.

Glycan Metabolic Fluorine Labeling for In Vivo Visualization of Tumor Cells and In Situ Assessment of Glycosylation Variations

The abnormality in the glycosylation of surface proteins is critical for the growth and metastasis of tumors and their capacity for immunosuppression and drug resistance. This anomaly offers an entry point for real-time analysis on glycosylation fluctuations. In this study, we report a strategy, glycan metabolic fluorine labeling (MEFLA), for selectively tagging glycans of tumor cells. As a proof of concept, we synthesized two fluorinated unnatural monosaccharides with distinctive 19 F chemical shifts (Ac4 ManNTfe and Ac4 GalNTfa). These two probes could undergo selective uptake by tumor cells and subsequent incorporation into surface glycans. This approach enables efficient and specific 19 F labeling of tumor cells, which permits in vivo tracking of tumor cells and in situ assessment of glycosylation changes by 19 F MRI. The efficiency and specificity of our probes for labeling tumor cells were verified in vitro with A549 cells. The feasibility of our method was further validated with in vivo experiments on A549 tumor-bearing mice. Moreover, the capacity of our approach for assessing glycosylation changes of tumor cells was illustrated both in vitro and in vivo. Our studies provide a promising means for visualizing tumor cells in vivo and assessing their glycosylation variations in situ through targeted multiplexed 19 F MRI.

A glycosylation-related signature predicts survival in pancreatic cancer

BACKGROUND

Tumor initiation and progression are closely associated with glycosylation. However, glycosylated molecules have not been the subject of extensive studies as prognostic markers for pancreatic cancer. The objectives of this study were to identify glycosylation-related genes in pancreatic cancer and use them to construct reliable prognostic models.

MATERIALS AND METHODS

The Cancer Genome Atlas and Gene Expression Omnibus databases were used to assess the differential expression of glycosylation-related genes; four clusters were identified based on consistent clustering analysis. Kaplan-Meier analyses identified three glycosylation-related genes associated with overall survival. LASSO analysis was then performed on The Cancer Genome Atlas and International Cancer Genome Consortium databases to identify glycosylation-related signatures. We identified 12 GRGs differently expressed in pancreatic cancer and selected three genes (SEL1L, TUBA1C, and SDC1) to build a prognostic model. Thereafter, patients were divided into high and low-risk groups. Eventually, we performed Quantitative real-time PCR (qRT-PCR) to validate the signature.

RESULTS

Clinical outcomes were significantly poorer in the high-risk group than in the low-risk group. There were also significant correlations between the high-risk group and several risk factors, including no-smoking history, drinking history, radiotherapy history, and lower tumor grade. Furthermore, the high-risk group had a higher proportion of immune cells. Eventually, three glycosylation-related genes were validated in human PC cell lines.

CONCLUSION

This study identified the glycosylation-related signature for pancreatic cancer. It is an effective predictor of survival and can guide treatment decisions.

Identification of a Novel Prognostic Signature Based on N-Linked Glycosylation and Its Correlation with Immunotherapy Response in Hepatocellular Carcinoma

Background

The complex tumor microenvironment of hepatocellular carcinoma (HCC) has led to a low response to immune checkpoints inhibitors (ICIs) and a poor prognosis. PD-L1, as one of the indications for ICIs, is rich in glycosylation modifications, which result in untimely ICIs. Our study constructed a prognostic model based on N-linked glycosylation related genes for predicting the prognosis and the response to ICIs.

Methods

The list of N-linked glycosylation related genes is from the AmiGO2 database. The patients in The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) cohorts were enrolled. The Cox regression was performed to develop a prognostic model and patients were divided into a low- and high-risk subgroups. The role of signature in HCC was well investigated by prognostic analysis, gene set enrichment analysis, and immune infiltration analysis. 21 recurrent HCC patients who received postoperative adjuvant ICIs were recruited to evaluate the relationship between immunotherapy response and the signature. In vitro studies were conducted to investigate the oncogenic effects of DDOST, STT3A and TMEM165 in HCC.

Results

59 N-linked glycosylation related differentially expressed genes were screened from HCC and normal tissues in the TCGA cohort. The prognostic model was developed with DDOST, STT3A and TMEM165. The risk score could be an independent prognostic factor. Patients in the high-risk subgroup showed a worse prognosis than patients in the low-risk one. ssGSEA showed that patients in the low-risk subgroup tended to be in the immune-activated state, with higher levels of B cell and macrophage cell infiltrations and lower levels of regulatory T cell (Treg) infiltrations in both TCGC and GEO cohorts. Immunohistochemistry studies showed that DDOST, STT3A and TMEM165 are highly expressed in tumor tissues and patients with a high-risk score correlated with poor progression free survival and worse immunotherapeutic response. Furthermore, the proliferation of HCC cells was reduced after the knockdown of DDOST, as well as upon the knockdown of STT3A and TMEM165.

Conclusion

In this study, we establish that the risk model based on N-linked glycosylation related genes could efficiently predict the prognosis and tumor microenvironment immune state of HCC patients, and the risk score could serve as a novel indicator of immunotherapy.

FUT8-Mediated Core Fucosylation Promotes the Pulmonary Vascular Remodeling in Pulmonary Arterial Hypertension

Pulmonary arterial hypertension (PAH) is a progressive cardiopulmonary disease with unclear underlying molecular mechanisms and limited therapeutic options. This study aimed to explore the role of core fucosylation and the only glycosyltransferase FUT8 in PAH. We observed increased core fucosylation in a monocrotaline (MCT)-induced PAH rat model and isolated rat pulmonary artery smooth muscle cells (PASMCs) treated with platelet-derived growth factor-BB (PDGF-BB). We found that 2-fluorofucose (2FF), a drug used to inhibit core fucosylation, improved hemodynamics and pulmonary vascular remodeling in MCT-induced PAH rats. In vitro, 2FF effectively restrains the proliferation, migration, and phenotypic switching of PASMCs and promotes apoptosis. Compared with controls, serum FUT8 concentration in PAH patients and MCT-induced rats was significantly elevated. FUT8 expression appeared increased in the lung tissues of PAH rats, and the co-localization of FUT8 with α-SMA was also observed. SiRNA was used to knockdown FUT8 in PASMCs (siFUT8). After effectively silencing FUT8 expression, phenotypic changes induced in PASMCs by PDGF-BB stimulation were alleviated. FUT8 activated the AKT pathway, while the admission of AKT activator SC79 could partially counteract the negative effect of siFUT8 on the proliferation, apoptotic resistance, and phenotypic switching of PASMCs, which may be involved in the core fucosylation of vascular endothelial growth factor receptor (VEGFR). Our research confirmed the critical role of FUT8 and its mediated core fucosylation in pulmonary vascular remodeling in PAH, providing a potential novel therapeutic target for PAH.

Design, synthesis and analysis of charged RGD derivatives

In the present study, negatively charged N-Biotin-RGD and positively charged C-Biotin-RGD were designed, synthesized, and characterized with docking analysis. The fixation of MDA-MB-231 cells with formalin made their cell surface neutrally charged thus removing the electrostatic interactions between charged biotinylated RGD derivatives and MDA-MB-231 cells. The results of the binding affinity of biotinylated RGD derivatives against MDA-MB-231 cells showed that N-Biotin-RGD had higher binding affinity than C-Biotin-RGD. The cytotoxic effect was analyzed by incubating charged biotinylated RGD derivatives with live MDA-MB-231 cells. MDA-MB-231 cell surface is negatively charged due to high hypersialyliation of polyglycans and Warburg effect. The results of their cytotoxic activities against live MDA-MB-231 cells were found to be electrostatic in nature. C-Biotin-RGD had an attractive interaction with the MDA-MB-231 cell surface resulting in a higher cytotoxic effect. In comparison, N-Biotin-RGD had a repulsive interaction with the MDA-MB-231 cell surface resulting in a lower cytotoxic effect. Hence, positively charged C-Biotin-RGD is a better cytotoxic agent than a negatively charged N-Biotin-RGD against MDA-MB-231 cells.

ROS impairs tumor vasculature normalization through an endocytosis effect of caveolae on extracellular SPARC

BACKGROUND

The accumulation of reactive oxygen species (ROS) in tumor microenvironment (TME) is an important player for tumorigenesis and progression. We aimed to explore the outcomes of ROS on tumor vessels and the potential regulated mechanisms.

METHODS

Exogenous H₂O₂ was adopted to simulate the ROS setting. Immunofluorescence staining and ultrasonography were used to assess the vascular endothelial coverage and perfusions in the tumors inoculated with Lewis lung cancer (LLC) and melanoma (B16F10) cells of C57BL/6 mice, respectively. ELISA and western-blot were used to detect the expression of secreted acidic and cysteine-rich protein (SPARC) and Caveale-1 in human umbilical vein endothelial cells (HUVEC) extra- and intracellularly. Intracellular translocation of SPARC was observed using electron microscopy and immunofluorescence approaches.

RESULT

Under the context of oxidative stress, the pericyte recruitment of neovascularization in mouse lung cancer and melanoma tissues would be aberrated, which subsequently led to the disruption of the tumor vascular architecture and perfusion dysfunction. In vitro, HUVEC extracellularly SPARC was down-regulated, whereas intracellularly it was up-regulated. By electron microscopy and immunofluorescence staining, we observed that SPARC might undergo transmembrane transport via caveale-1-mediated endocytosis. Finally, the binding of SPARC to phosphorylated-caveale-1 was also detected in B16F10 tissues.

CONCLUSION

In the oxidative stress environment, neovascularization within the tumor occurs structural deterioration and decreased perfusion capacity. One of the main regulatory mechanisms is the migration of extracellular SPARC from the endothelium to intracellular compartments via Caveolin-1 carriers.

Role of EGFL7 in human cancers: A review

EGFL7 is a proangiogenic factor. It has been widely described with having a vital role in tubulogenesis and regulation of angiogenesis, mainly during embryogenesis and organogenesis. It has been mainly associated with NOTCH pathway, but there are reports showing association with MAPK and integrin pathways. Given its association with angiogenesis and these other pathways, there are several studies associating EGFL7 with carcinogenesis. In fact, most of the studies have pointed to EGFL7 as an oncogene, and some of them suggest EGFL7 expression as a possible biomarker of prognosis or use for a patient's follow-up. Here, we review the molecular pathways which EGFL7 is associated and highlight several studies describing the role of EGFL7 in tumorigenesis, separated by tumor type. Besides its role on angiogenesis, EGFL7 may act in other pathways as oncogene, which makes it a possible biomarker and a candidate to targeted therapy.

Roles of glycosylation at the cancer cell surface: opportunities for large scale glycoproteomics

Cell surface glycosylation has a variety of functions, and its dysregulation in cancer contributes to impaired signaling, metastasis and the evasion of the immune responses. Recently, a number of glycosyltransferases that lead to altered glycosylation have been linked to reduced anti-tumor immune responses: B3GNT3, which is implicated in PD-L1 glycosylation in triple negative breast cancer, FUT8, through fucosylation of B7H3, and B3GNT2, which confers cancer resistance to T cell cytotoxicity. Given the increased appreciation of the relevance of protein glycosylation, there is a critical need for the development of methods that allow for an unbiased interrogation of cell surface glycosylation status. Here we provide an overview of the broad changes in glycosylation at the surface of cancer cell and describe selected examples of receptors with aberrant glycosylation leading to functional changes, with emphasis on immune checkpoint inhibitors, growth-promoting and growth-arresting receptors. Finally, we posit that the field of glycoproteomics has matured to an extent where large-scale profiling of intact glycopeptides from the cell surface is feasible and is poised for discovery of new actionable targets against cancer.

Enhancement of immune surveillance in breast cancer by targeting hypoxic tumor endothelium: Can it be an immunological switch point?

Breast cancer ranks second among the causes of cancer-related deaths in women. In spite of the recent advances achieved in the diagnosis and treatment of breast cancer, further study is required to overcome the risk of cancer resistance to treatment and thereby improve the prognosis of individuals with advanced-stage breast cancer. The existence of a hypoxic microenvironment is a well-known event in the development of mutagenesis and rapid proliferation of cancer cells. Tumor cells, purposefully cause local hypoxia in order to induce angiogenesis and growth factors that promote tumor growth and metastatic characteristics, while healthy tissue surrounding the tumor suffers damage or mutate. It has been found that these settings with low oxygen levels cause immunosuppression and a lack of immune surveillance by reducing the activation and recruitment of tumor infiltrating leukocytes (TILs). The immune system is further suppressed by hypoxic tumor endothelium through a variety of ways, which creates an immunosuppressive milieu in the tumor microenvironment. Non responsiveness of tumor endothelium to inflammatory signals or endothelial anergy exclude effector T cells from the tumor milieu. Expression of endothelial specific antigens and immunoinhibitory molecules like Programmed death ligand 1,2 (PDL-1, 2) and T cell immunoglobulin and mucin-domain containing-3 (TIM-3) by tumor endothelium adds fuel to the fire by inhibiting T lymphocytes while promoting regulatory T cells. The hypoxic microenvironment in turn recruits Myeloid Derived Suppressor Cells (MDSCs), Tumor Associated Macrophages (TAMs) and T regulatory cells (Treg). The structure and function of newly generated blood vessels within tumors, on the other hand, are aberrant, lacking the specific organization of normal tissue vasculature. Vascular normalisation may work for a variety of tumour types and show to be an advantageous complement to immunotherapy for improving tumour access. By enhancing immune response in the hypoxic tumor microenvironment, via immune-herbal therapeutic and immune-nutraceuticals based approaches that leverage immunological evasion of tumor, will be briefly reviewed in this article. Whether these tactics may be the game changer for emerging immunological switch point to attenuate the breast cancer growth and prevent metastatic cell division, is the key concern of the current study.

FUT2 inhibits the EMT and metastasis of colorectal cancer by increasing LRP1 fucosylation

BACKGROUND

Fucosyltransferase 2(FUT2) and its induced α-1,2 fucosylation is associated with cancer metastasis. However, the role of FUT2 in colorectal cancer (CRC) metastasis remains unclear.

METHODS

The expression levels and clinical analyses of FUT2 were assessed in CRC samples. Migration and invasion assays, EMT detection, nude mice peritoneal dissemination models and intestinal specific FUT2 knockout mice (FUT2^△IEC mice) were used to investigate the effect of FUT2 on metastasis in colorectal cancer. Quantitative proteomics study of glycosylated protein, UEA enrichment, Co-immunoprecipitation identified the mediator of the invasive-inhibiting effects of FUT2.

RESULTS

FUT2 is downregulated in CRC tissues and is positively correlated with the survival of CRC patients. FUT2 is an inhibitor of colorectal cancer metastasis which, when overexpressed, suppresses invasion and tumor dissemination in vitro and in vivo. FUT2 knock-out mice (FUT2^△IEC mice) develop AMO and DSS-induced tumors and promote EMT in colorectal cancers. FUT2-induced α-1,2 fucosylation impacts the ability of low-density lipoprotein receptor-related protein 1(LRP1) to suppress colorectal cancer invasion.

CONCLUSIONS

Our study demonstrated that FUT2 induces α-1,2 fucosylation and inhibits EMT and metastasis of colorectal cancer through LRP1 fucosylation, suggesting that FUT2 may serve as a therapeutic target for colorectal cancer. Video Abstract.

Enrichment and fragmentation approaches for enhanced detection and characterization of endogenous glycosylated neuropeptides

Glycosylated neuropeptides were recently discovered in crustaceans, a model organism with a well-characterized neuroendocrine system. Several workflows exist to characterize enzymatically digested peptides; however, the unique properties of endogenous neuropeptides require methods to be re-evaluated. We investigate the use of hydrophilic interaction liquid chromatography (HILIC) enrichment and different fragmentation methods to further probe the expression of glycosylated neuropeptides in Callinectes sapidus. During the evaluation of HILIC, we observed the necessity of a less aqueous solvent for endogenous peptide samples. This modification enabled the number of detected neuropeptide glycoforms to increase almost two-fold, from 18 to 36. Product ion-triggered electron-transfer/higher-energy collision dissociation enabled the site-specific detection of 55 intact N- and O-linked glycoforms, while the faster stepped collision energy higher-energy collisional dissociation resulted in detection of 25. Additionally, applying this workflow to five neuronal tissues enabled the characterization of 36 more glycoforms of known neuropeptides and 11 more glycoforms of nine putative novel neuropeptides. Overall, the database of glycosylated neuropeptides in crustaceans was largely expanded from 18 to 136 glycoforms of 40 neuropeptides from 10 neuropeptide families. Both macro- and micro-heterogeneity were observed, demonstrating the chemical diversity of this simple invertebrate, establishing a framework to use crustacean to probe modulatory effects of glycosylation on neuropeptides.

Emerging Roles of the Unique Molecular Chaperone Cosmc in the Regulation of Health and Disease

The core-1 β1-3galactosyltransferase-specific chaperone 1 (Cosmc) is a unique molecular chaperone of core-1 β1-3galactosyltransferase(C1GALT1), which typically functions inside the endoplasmic reticulum (ER). Cosmc helps C1GALT1 to fold correctly and maintain activity. It also participates in the synthesis of the T antigen, O-glycan, together with C1GALT1. Cosmc is a multifaceted molecule with a wide range of roles and functions. It involves platelet production and the regulation of immune cell function. Besides that, the loss of function of Cosmc also facilitates the development of several diseases, such as inflammation diseases, immune-mediated diseases, and cancer. It suggests that Cosmc is a critical control point in diseases and that it should be regarded as a potential target for oncotherapy. It is essential to fully comprehend Cosmc's roles, as they may provide critical information about its involvement in disease development and pathogenesis. In this review, we summarize the recent progress in understanding the role of Cosmc in normal development and diseases.

Research progress on anti-ovarian cancer mechanism of miRNA regulating tumor microenvironment

Ovarian cancer is the most deadly malignancy among women, but its complex pathogenesis is unknown. Most patients with ovarian cancer have a poor prognosis due to high recurrence rates and chemotherapy resistance as well as the lack of effective early diagnostic methods. The tumor microenvironment mainly includes extracellular matrix, CAFs, tumor angiogenesis and immune-associated cells. The interaction between tumor cells and TME plays a key role in tumorigenesis, progression, metastasis and treatment, affecting tumor progression. Therefore, it is significant to find new tumor biomarkers and therapeutic targets. MicroRNAs are non-coding RNAs that post-transcriptionally regulate the expression of target genes and affect a variety of biological processes. Studies have shown that miRNAs regulate tumor development by affecting TME. In this review, we summarize the mechanisms by which miRNAs affect ovarian cancer by regulating TME and highlight the key role of miRNAs in TME, which provides new targets and theoretical basis for ovarian cancer treatment.

Targeting glycans for CAR therapy: The advent of sweet CARs

Chimeric antigen receptor (CAR) T cell therapy has created a paradigm shift in the treatment of hematologic malignancies but has not been as effective toward solid tumors. For such tumors, the primary obstacles facing CAR T cells are scarcity of tumor-specific antigens and the hostile and complex tumor microenvironment. Glycosylation, the process by which sugars are post-translationally added to proteins or lipids, is profoundly dysregulated in cancer. Abnormally glycosylated glycoproteins expressed on cancer cells offer unique targets for CAR T therapy as they are specific to tumor cells. Tumor stromal cells also express abnormal glycoproteins and thus also have the potential to be targeted by glycan-binding CAR T cells. This review will discuss the state of CAR T cells in the therapy of solid tumors, the cancer glycoproteome and its potential for use as a therapeutic target, and the landscape and future of glycan-binding CAR T cell therapy.

Mass spectrometry and the cellular surfaceome

The collection of exposed plasma membrane proteins, collectively termed the surfaceome, is involved in multiple vital cellular processes, such as the communication of cells with their surroundings and the regulation of transport across the lipid bilayer. The surfaceome also plays key roles in the immune system by recognizing and presenting antigens, with its possible malfunctioning linked to disease. Surface proteins have long been explored as potential cell markers, disease biomarkers, and therapeutic drug targets. Despite its importance, a detailed study of the surfaceome continues to pose major challenges for mass spectrometry-driven proteomics due to the inherent biophysical characteristics of surface proteins. Their inefficient extraction from hydrophobic membranes to an aqueous medium and their lower abundance compared to intracellular proteins hamper the analysis of surface proteins, which are therefore usually underrepresented in proteomic datasets. To tackle such problems, several innovative analytical methodologies have been developed. This review aims at providing an extensive overview of the different methods for surfaceome analysis, with respective considerations for downstream mass spectrometry-based proteomics.

Role of endoplasmic reticulum stress in impaired neonatal lung growth and bronchopulmonary dysplasia

Myeloperoxidase (MPO), oxidative stress (OS), and endoplasmic reticulum (ER) stress are increased in the lungs of rat pups raised in hyperoxia, an established model of bronchopulmonary dysplasia (BPD). However, the relationship between OS, MPO, and ER stress has not been examined in hyperoxia rat pups. We treated Sprague-Dawley rat pups with tunicamycin or hyperoxia to determine this relationship. ER stress was detected using immunofluorescence, transcriptomic, proteomic, and electron microscopic analyses. Immunofluorescence observed increased ER stress in the lungs of hyperoxic rat BPD and human BPD. Proteomic and morphometric studies showed that tunicamycin directly increased ER stress of rat lungs and decreased lung complexity with a BPD phenotype. Previously, we showed that hyperoxia initiates a cycle of destruction that we hypothesized starts from increasing OS through MPO accumulation and then increases ER stress to cause BPD. To inhibit ER stress, we used tauroursodeoxycholic acid (TUDCA), a molecular chaperone. To break the cycle of destruction and reduce OS and MPO, we used N-acetyl-lysyltyrosylcysteine amide (KYC). The fact that TUDCA improved lung complexity in tunicamycin- and hyperoxia-treated rat pups supports the idea that ER stress plays a causal role in BPD. Additional support comes from data showing TUDCA decreased lung myeloid cells and MPO levels in the lungs of tunicamycin- and hyperoxia-treated rat pups. These data link OS and MPO to ER stress in the mechanisms mediating BPD. KYC's inhibition of ER stress in the tunicamycin-treated rat pup's lung provides additional support for the idea that MPO-induced ER stress plays a causal role in the BPD phenotype. ER stress appears to expand our proposed cycle of destruction. Our results suggest ER stress evolves from OS and MPO to increase neonatal lung injury and impair growth and development. The encouraging effect of TUDCA indicates that this compound has the potential for treating BPD.

Glycosylation modification patterns reveal distinct tumor metabolism and immune microenvironment landscape in lower-grade gliomas

Glycosylation alterations, a key driver throughout tumorigenesis and tumor progression, could regulate the microenvironment and immune response as well as lead to harmful metabolism and cell signaling. In this study, we first comprehensively evaluated the glycosylation modification patterns of LGGs based on glycosyltransferase family genes and systematically integrated these modification patterns with tumor metabolism and immune microenvironment characteristics. Glycosylation score was also developed to quantify glycosylation modification patterns of individuals. As a result, two glycosylation modification patterns were identified, with distinct prognosis, metabolism, and immune microenvironment features. The glycosylation subtype A and cluster A were characterized by higher carbohydrates and amino acid metabolism activity, higher levels of infiltrating cells, and poor prognosis, whereas an opposite modification pattern was observed in glycosylation subtype B and cluster B. In addition, a high glycosylation score is closer to a microenvironment characterized by chronic inflammation, immunosuppression, and tumor promotion. Following analysis and validation, the glycosylation score was a reliable and independent prognostic index. More importantly, the glycosylation score influenced the response to immunotherapy, chemotherapy, or targeted therapy, which provided a novel insight into promoting personalized therapy in the future and may contribute to developing novel therapeutic drugs or exploring promising drug combination therapy strategies.

Glycoprotein α-Subunit of Glucosidase II (GIIα) is a novel prognostic biomarker correlated with unfavorable outcome of urothelial carcinoma

Background

Urothelial carcinoma (UC) is among the most prevalent malignancies. The muscle-invasive bladder cancer (MIBC) shows an invasive feature and has poor prognosis, while the non-muscle invasive bladder cancer (NMIBC) shows a better prognosis as compared with the MIBC. However, a significant proportion (10%–30%) of NMIBC cases progress to MIBC. Identification of efficient biomarkers for the prediction of the course of UC remains challenging nowadays. Recently, there is an emerging study showed that post-translational modifications (PTMs) by glycosylation is an important process correlated with tumor angiogenesis, invasion and metastasis. Herein, we reported a data-driven discovery and experimental validation of GANAB, a key regulator of glycosylation, as a novel prognostic marker in UC.

Methods

In the present study, we conducted immunohistochemistry (IHC) assay to evaluate the correlation between the expression levels of GANAB protein and the prognosis of UC in our cohort of 107 samples using whole slide image (WSI) analysis. In vitro experiments using RNAi were also conducted to investigate the biological functions of GANAB in UC cell lines.

Results

We observed that positive GANAB protein expression was significantly correlated with poor prognosis of UC in our cohort, with p-value of 0.0017 in Log-rank test. Notably, tumor cells at the invasive front of the tumor margin showed stronger GANAB expression than the tumor cells inside the tumor body in UCs. We further validated that the elevated expression levels of GANAB were significantly correlated with high grade tumors (p-values of 1.72 × 10^–10), advanced stages (6.47 × 10^–6), and elevated in luminal molecular subtypes. Moreover, knocking-down GANAB using RNAi in UM-UC-3 and T24 cells inhibited cell proliferation and migration in vitro. Knockdown of GANAB resulted in cell cycle arrest at G1 phase. We demonstrated that GANAB mediated HIF1A and ATF6 transcriptional activation in the ER stress signaling, and regulated the gene expression of cell cycle-related transcriptional factors E2F7 and FOXM1.

Conclusions

The elevated expression of GANAB is a novel indicator of poorer prognosis of UC. Our data suggests that GANAB is not only a new and promising prognostic biomarker for UC, but also may provide important cues for the development of PTM-based therapeutics for UC treatment.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09884-8.

Complementary proteome and glycoproteome access revealed through comparative analysis of reversed phase and porous graphitic carbon chromatography

Continual developments in instrumental and analytical techniques have aided in establishing rigorous connections between protein glycosylation and human illness. These illnesses, such as various forms of cancer, are often associated with poor prognoses, prompting the need for more comprehensive characterization of the glycoproteome. While innovative instrumental and computational strategies have largely benefited glycoproteomic analyses, less attention is given to benefits gained through alternative, optimized chromatographic techniques. Porous graphitic carbon (PGC) chromatography has gained considerable interest in glycomics research due to its mobile phase flexibility, increased retention of polar analytes, and improved structural elucidation at higher temperatures. PGC has yet to be systematically compared against or in tandem with standard reversed phase liquid chromatography (RPLC) in high-throughput bottom-up glycoproteomic experiments, leaving the potential benefits unexplored. Performing comparative analysis of single and biphasic separation regimes at a range of column temperatures illustrates complementary advantages for each method. PGC separation is shown to selectively retain shorter, more hydrophilic glycopeptide species, imparting higher average charge, and exhibiting greater microheterogeneity coverage for identified glycosites. Additionally, we demonstrate that liquid-phase separation of glycopeptide isomers may be achieved through both single and biphasic PGC separations, providing a means towards facile, multidimensional glycopeptide characterization. Beyond this, we demonstrate how utilization of multiple separation regimes and column temperatures can aid in profiling the glycoproteome in tumorigenic and aggressive prostate cancer cells. RAW MS proteomic and glycoproteomic datasets have been deposited to the ProteomeXchange Consortium via the PRIDE partner repository with the dataset identifier PXD024196 (10.6019/PXD024196) and PXD024195, respectively.

The RAGE/multiligand axis: a new actor in tumor biology

The receptor for advanced glycation end-products (RAGE) is a multiligand binding and single-pass transmembrane protein which actively participates in several chronic inflammation-related diseases. RAGE, in addition to AGEs, has a wide repertoire of ligands, including several damage-associated molecular pattern molecules or alarmins such as HMGB1 and members of the S100 family proteins.

Over the last years, a large and compelling body of evidence has revealed the active participation of the RAGE axis in tumor biology based on its active involvement in several crucial mechanisms involved in tumor growth, immune evasion, dissemination, as well as by sculpturing of the tumor microenvironment as a tumor-supportive niche. In the present review, we will detail the consequences of the RAGE axis activation to fuel essential mechanisms to guarantee tumor growth and spreading.

Silencing GOLGA8B inhibits cell invasion and metastasis by suppressing STAT3 signaling pathway in lung squamous cell carcinoma

Changes to some Golgi subfamily member proteins are reported to be involved in tumor metastasis. However, the functional role and potential mechanism of the Golgi A8 family member B (GOLGA8B) in lung squamous cell carcinoma (LUSC) remains unknown. In the present study, GOLGA8B expression was detected using qRT-PCR, Western blot, and immunohistochemistry (IHC). In vivo animal experiments and in vitro functional assays were performed to explore the function of GOLGA8B in LUSC. Luciferase assays were performed to investigate the underlying targets of GOLGA8B in LUSC. GOLGA8B was shown to be highly expressed in LUSC metastasis tissue, and significantly associated with the distant metastasis-free survival of LUSC patients. Loss-of-function assays indicated that silencing GOLGA8B suppressed LUSC cell tumorigenesis in vivo and weakened in vitro invasion and migration. GOLGA8B silencing-induced inhibition of invasion and migration was associated with the inactivation of STAT3 signaling. Importantly, these results showed that the number of circulating tumor cells (CTCs) was markedly higher in the GOLGA8B silencing group than in the control vector group. GOLGA8B expression was positively associated with p-STAT3 expression in LUSC tissue. Study findings revealed a novel mechanism by which GOLGA8B promotes tumor metastasis in LUSC cells and suggests that this protein could be a promising target for antitumor metastasis therapy in LUSC patients.

Expression of ALG3 in Hepatocellular Carcinoma and Its Clinical Implication

Background: Recent studies have shown that alpha-1,3-mannosyltransferase (ALG3) promoted tumorigenesis and progression in multiple cancer types. Our study planned to explore the clinical implication and potential function of ALG3 in hepatocellular carcinoma.

Materials and Methods: Data from public databases were used to analyze the ALG3 expression and its impact on the clinical significance of patients with HCC. The ALG3 expression was confirmed by qRT-PCR and Western blot. Immunohistochemistry was used to confirm the ALG3 expression and explore its clinical implication in HCC. KEGG, GO, and GSEA enrichment analyses were utilized to explore the biological pathways related to ALG3 in HCC. TIMER2.0 was applied to assess the association between ALG3 and immune infiltration. CCK8, MTT, and transwell assays were used to investigate the role of ALG3 downregulation in HCC cell lines.

Results: qRT-PCR, WB, and IHC proved ALG3 was highly overexpressed in HCC tissues. The Kaplan–Meier analysis verified the overexpression of ALG3 was related to poor overall survival (p < 0.001). Multivariate cox regression analysis showed that the high ALG3 expression was an independent risk prognostic factor. GSEA and TIMER2.0 predicted that ALG3 participates in cell differentiation and cycle and correlates with immune cell infiltration. Transwell assay results showed that ALG3 silencing also impaired the invasion ability of HCC cells.

Conclusion: ALG3 was overexpressed and considered a potential indicator of survival in HCC, and our findings provided a novel therapeutic target for HCC.

Identification of Angiogenesis-Related Prognostic Biomarkers Associated With Immune Cell Infiltration in Breast Cancer

Background: This study aimed to explore the prognostic value of angiogenesis-related genes (ARGs) and their association with immune cell infiltration (ICI) in breast cancer (BC).

Methods: Transcriptome data of BC were obtained from the TCGA and GEO databases. Differentially expressed ARGs were identified by the limma package. The identification of key genes and construction of the risk score model were performed by univariate and multivariate Cox regression algorithms. The prognostic value of the risk score was assessed by ROC curves and nomogram. GO, KEGG pathway, and GSEA were used to investigate the biological functions of differentially expressed genes (DEGs), and CIBERSORT, ssGSEA, and xCell algorithms were performed to estimate the ICI in high-risk and low-risk groups. The correlations between prognostic biomarkers and differentially distributed immune cells were assessed. Moreover, a ceRNA regulatory network based on prognostic biomarkers was constructed and visualized by Cytoscape software.

Results: A total of 18 differentially expressed ARGs were identified between tumor and adjacent normal tissue samples. TNFSF12, SCG2, COL4A3, and TNNI3 were identified as key prognostic genes by univariate and multivariate Cox regression analyses. The risk score model was further constructed based on the four-gene signature and validated in GSE7390 and GSE88770 datasets. ROC curves and nomogram indicated that the risk score had good accuracy for determining BC patient survival. Biological function analysis showed that DEGs in high- and low-risk groups had a high enrichment in immune-related biological processes and signaling pathways. Moreover, significantly different ICIs were found between high- and low-risk groups, such as memory B cells, CD8⁺ T cells, resting memory CD4⁺ T cells, follicular helper T cells, regulatory T cells, monocytes, M2 macrophages, and neutrophils, and each prognostic biomarker was significantly correlated with one or more immune cell types.

Conclusion: The current study identified novel prognostic ARGs and developed a prognostic model for predicting survival in patients with BC. Furthermore, this study indicated that ICI may act as a bond between angiogenesis and BC. These findings enhance our understanding of angiogenesis in BC and provide novel guidance on developing therapeutic targets for BC patients.

Tumor-Derived Exosome FGD5-AS1 Promotes Angiogenesis, Vascular Permeability, and Metastasis in Thyroid Cancer by Targeting the miR-6838-5p/VAV2 Axis

Exosomes are small vesicles with a diameter of 30~150 nm secreted by cells, which are rich in mRNA, microRNA, and long noncoding RNA (lncRNA). The biological functions of most exosomal lncRNAs are not well understood. Studies have shown that tumor exosome FGD5-AS1 plays an important role in the proliferation, migration, and invasion of tumor cells. In this study, SW1736 and KAT18 TC cells with high expression of FGD5-AS1 were screened. Exosomes with high expression of FGD5-AS1 were collected. The collected exosomes were then added to HUVEC cells. After incubation for 24 h, the effects on the proliferation and migration of HUVEC cells and vascular permeability were detected. The results showed that TC cells SW1736 and KAT18 could secrete a large number of exosomes, which could be taken up by HUVEC cells. Overexpression of FGD5-AS1 enhanced proliferation, migration, angiogenesis, and permeability of HUVEC. This effect is achieved through activation of the miR-6838-5p/VAV2 axis. These results suggest that FGD5-AS1 in tumor-derived exoskeleton promotes angiogenesis, vascular permeability, and metastasis by regulating the endothelial miR-6838-5p/VAV2 axis and ultimately promotes the occurrence and development of TC.

Roles and new Insights of Macrophages in the Tumor Microenvironment of Thyroid Cancer

Although most thyroid cancers have a good and predictable prognosis, the anaplastic, medullary, and refractory thyroid cancers still prone to recurrence and metastasis, resulting in poor prognosis. Although a number of newly developed targeted therapies have begun to be indicated for the above types of thyroid cancer in recent years, their ability to improve overall survival remain hindered by low efficacy. As the largest component of immune cells in tumor microenvironment, tumor-associated macrophages play a key role in the invasion and metastasis of thyroid cancer. There is much evidence that the immune system, tumor microenvironment and cancer stem cell interactions may revolutionize traditional therapeutic directions. Tumor-associated macrophages have been extensively studied in a variety of tumors, however, research on the relationship between thyroid cancer and macrophages is still insufficient. In this review, we summarize the functions of tumor-associated macrophages in different types of thyroid cancer, their cytokines or chemokines effect on thyroid cancer and the mechanisms that promote tumor proliferation and migration. In addition, we discuss the mechanisms by which tumor-associated macrophages maintain the stemness of thyroid cancer and potential strategies for targeting tumor-associated macrophages to treat thyroid cancer.

The critical role of B4GALT4 in promoting microtubule spindle assembly in HCC through the regulation of PLK1 and RHAMM expression

Beta 1,4-galactosyltransferase (B4GALT)-family glycosyltransferases are involved in multiple biological processes promoting cancer progression, regulating the dynamic network of cancer cell proliferation and apoptosis, and are associated with metastasis. However, their roles in the dysregulation of expressions and functions in hepatocellular carcinoma (HCC) remain unclear. Herein, bioinformatic approaches have been applied to investigate their expression profiles, and to obtain correlations between gene expressions and clinicopathological parameters as well as downstream target genes in HCC. Multiple databases were used to screen the expressions of B4GALT family members in tumor tissues, and to evaluate their prognostic value among HCC patients in different aspects. Results indicated an overall upregulation of B4GALTs' transcription levels in tumor tissues and a strong correlation with poor prognosis. Through Gene Ontology analysis, gene set enrichment analysis, and verification of single-cell RNA sequencing data, we established a connection between the B4GALT family and microtubule spindle assembly, which particularly highlighted the role of B4GALT4 in this phenomenon. B4GALT4 knockdown downregulated the production of lumican, and repressed the expressions of polo-like kinase 1 and RHAMM by regulating the transforming growth factor-beta pathway, thus suggesting that B4GALT4 is a critical promotor for HCC. We believe that these studies will provide valuable insight into the role of B4GALT family members in HCC and lead to the development of new strategies to improve the outcomes for patients with HCC.

System-Wide Quantitative N-Glycoproteomic Analysis from K562 Cells and Mouse Liver Tissues

As a key regulator of many biological processes, glycosylation is an essential post-translational modification (PTM) in the living system. Over 50% of human proteins are known to be glycosylated. Alterations in glycoproteins are directly linked to many diseases, making it crucial to understand system-wide glycosylation changes. The majority of known glycoproteins are from plasma membrane; however, glycosylation is a dynamic process that occurs throughout multiple subcellular organelles and involves sets of enzymes, chaperones, transporters, and sugar donor molecules. Many glycoproteins are expressed not only in plasma membranes but also in subcellular organelles. Here, we developed a mass-spectrometry-based quantitative workflow for the system-wide N-glycoproteomic analysis of membrane and cytosolic proteins extracted using a MEM-PER kit. The kit facilitates the extraction and solubilization of both membrane and cytosolic proteins in a simple, efficient, and reproducible manner. We analyzed the K562 cell line and mouse liver tissue to evaluate this approach. A total of 934 glycosites, 5154 glycopeptides, and 536 glycoproteins from the K562 cell line and a total of 1449 glycosites, 7549 glycopeptides, and 660 glycoproteins from mouse liver tissue were identified. This simple and reproducible approach provides a unique way to understand system-wide glycosylation in biological processes and enables the identification and quantitation of glycan profiles at glycosylation sites in proteins.

A glycosyltransferase gene signature to detect pancreatic ductal adenocarcinoma patients with poor prognosis

Background

Pancreatic ductal adenocarcinoma (PDAC) is characterized by an important heterogeneity, reflected by different clinical outcomes and chemoresistance. During carcinogenesis, tumor cells display aberrant glycosylated structures, synthetized by deregulated glycosyltransferases, supporting the tumor progression. In this study, we aimed to determine whether PDAC could be stratified through their glycosyltransferase expression profiles better than the current binary classification (basal-like and classical) in order to improve detection of patients with poor prognosis.

Methods

Bioinformatic analysis of 169 glycosyltransferase RNA sequencing data were performed for 74 patient-derived xenografts (PDX) of resected and unresectable tumors. The Australian cohort of International Cancer Genome Consortium and the microarray dataset from Puleo patient's cohort were used as independent validation datasets.

Findings

New PDAC stratification based on glycosyltransferase expression profile allowed to distinguish different groups of patients with distinct clinical outcome (p-value = 0.007). A combination of 19 glycosyltransferases differentially expressed in PDX defined a glyco-signature, whose prognostic value was validated on datasets including resected whole tumor tissues. The glyco-signature was able to discriminate three clusters of PDAC patients on the validation cohorts, two clusters displaying a short overall survival compared to one cluster having a better prognosis. Both poor prognostic clusters having different glyco-profiles in Puleo patient's cohort were correlated with stroma activated or desmoplastic subtypes corresponding to distinct microenvironment features (p-value < 0.0001). Besides, differential expression and enrichment analyses revealed deregulated functional pathways specific to different clusters.

Interpretation

This study identifies a glyco-signature relevant for a prognostic use, potentially applicable to resected and unresectable PDAC. Furthermore, it provides new potential therapeutic targets.

Funding

This work was supported by INCa (Grants number 2018-078 and 2018-079), Fondation ARC (Grant number ARCPJA32020070002326), Cancéropôle PACA, DGOS (labelization SIRIC, Grant number 6038), Amidex Foundation and Ligue Nationale Contre le Cancer and by institutional fundings from INSERM and the Aix-Marseille Université.

Potential Regulatory Roles of GRK2 in Endothelial Cell Activity and Pathological Angiogenesis

G protein-coupled receptor (GPCR) kinase 2 (GRK2) is an integrative node in many signaling network cascades. Emerging evidence indicates that GRK2 can interact with a large number of GPCRs and non-GPCR substrates in both kinase-dependent and -independent modes. Some of these pathways are associated with endothelial cell (EC) activity. The active state of ECs is a pivotal factor in angiogenesis. The occurrence and development of some inflammation-related diseases are accompanied by pathological angiogenesis, but there remains a lack of effective targeted treatments. Alterations in the expression and/or localization of GRK2 have been identified in several types of diseases and have been demonstrated to regulate the angiogenesis process in these diseases. GRK2 as a target may be a promising candidate for anti-angiogenesis therapy.

Proteomic screening of potential N-glycoprotein biomarkers for colorectal cancer by TMT labeling combined with LC-MS/MS

BACKGROUND AND AIMS

Colorectal cancer (CRC) is part of the most widespread malignant tumors. At present, colonoscopy is a routine procedure in the diagnosis of CRC, but it is traumatic. Carcinoembryonic antigen, CA199, and CA242 are common serum markers for the diagnosis of CRC; however, they do not demonstrate satisfactory specificity and sensitivity for the diagnosis of CRC. Hence, Now it is necessary to screen many valuable serum biomarkers for CRC, proteomics methods have been used to investigate PTMs such as glycosylation of proteins with prominent roles in the occurrence and development of tumors.

METHODS

This study screens altering glycosylated proteins of CRC tissues using LC-MS/MS quantitative glycoproteomics, and then these candidate biomarkers for CRC are further validated by serum glycoproteomics.

RESULTS

The results of glycoproteomics in CRC tissues show that the abundance of 160 and 79 glycerogelatin proteins was obviously upregulated and downregulated compared with their adjacent tissues(P < 0.05). Bioinformatics analysis suggests that these molecules are mainly involved in many biological processes, including skeletal system development, collagen fibril organization, and receptor-mediated endocytosis. Results of serum glycoproteomics show that the changing trends of 2 protein glycosylation were consistent with MS results of CRC tissues, including ICAM1and APMAP. Areas under the ROC curve (AUC) results confirm that ICAM1and APMAP as early immune diagnosis markers of CRC has excellent sensitivity and specificity.

CONCLUSION

The ICAM1 and APMAP may serve as a potential tumor marker for CRC.

UAP1L1 plays an oncogene-like role in glioma through promoting proliferation and inhibiting apoptosis

BACKGROUND

Uridine diphosphate-N-acetylglucosamine pyrophosphorylase-1-like-1 (UAP1L1) is involved in protein glycosylation and promotes proliferation in some tumors. By analyzing the publicly available Gene Expression Omnibus (GEO) database, we found that UAP1L1 displayed a significant change between paired glioma and normal brain tissues. The purpose of this study was to investigate the expression and functional role of UAP1L1 in glioma.

METHODS

To determine the expression level of UAP1L1 in glioma, immunohistochemistry (IHC) staining was performed in tissue microarrays of 160 gliomas and 24 normal brain tissues. The correlation between UAP1L1 expression and the outcomes of glioma patients was analyzed. Human glioblastoma cell lines, U251 and U87, were employed in this study. Endogenous UAP1L1 expression in U251 and U87 cells was detected by quantitative real-time polymerase chain reaction (qRT-PCR). A lentiviral short hairpin RNA (shRNA) vector (shUAP1L1) was constructed and used to infect U251 and U87 cells to knock down the expression of UAP1L1. We performed 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, colony formation assay, flow cytometry, human apoptosis antibody array, and in vivo subcutaneous xenograft model to investigate the biological functions of UAP1L1.

RESULTS

We revealed that UAP1L1 expression was obviously upregulated in the glioma tissues. The increased UAP1L1 expression level was clinically associated with higher tumor grades and poorer patient prognoses. Moreover, we demonstrated that UAP1L1 knockdown suppressed proliferation and increased apoptosis of glioma cells in vitro. In the xenograft mouse model, we further verified that UAP1L1 knockdown could attenuate the growth of glioma cells in vivo.

CONCLUSIONS

These results indicated that UAP1L1 may play an oncogene-like role in glioma, especially in high grade glioma, and thus may be of clinical importance as a future therapeutic target.

FUT7 Promotes the Epithelial-Mesenchymal Transition and Immune Infiltration in Bladder Urothelial Carcinoma

Background

Bladder urothelial carcinoma (BLCA) is one of the most frequently appearing, lethal and aggressive malignancies of the genitourinary system with growing morbidity and mortality, which affects human health seriously. Protein glycosylation, catalyzed by specific glycosyltransferase, has been found to be abnormal in several diseases, especially cancer. Fucosyltransferase VII (FUT7), one of the fucosyltransferases, was observed abnormally expressed in various cancers, however, the role of FUT7 in BLCA, and the association between its expression and clinical outcomes or immune infiltration remains unclear.

Methodology

FUT7 expression in BLCA was analyzed in Oncomine database, which was further confirmed with immunohistochemistry and ELISA. The prognostic value of FUT7 for BLCA was evaluated with PrognoScan database, and its genetic alteration was examined in cBioPortal database. The proliferation, migration, invasion and epithelial–mesenchymal transition (EMT) changes of bladder cancer cells after FUT7 siRNA or cDNA transfection were determined by CCK8, colony formation, transwell and Western blot, respectively. The correlation between FUT7 expression and immune infiltration levels was analyzed in TIMER and TISIDB databases, and the methylation level of FUT7 was detected in UALCAN database.

Results

The results showed that the expression of FUT7 was increased in BLCA, and patients with high FUT7 level were predicted to have lower overall survival and disease-specific survival rates, which were not influenced by FUT7 genetic alterations. Downregulation FUT7 inhibited the proliferation, migration, invasion and EMT of bladder cancer cells, whereas upregulation of FUT7 showed the opposite effects. We found that FUT7 was positively correlated with immune cell infiltration levels (CD8+ T cells, CD4+T cells, macrophage, neutrophil and dendritic cells), and also the expression of gene markers of immune cells. The negative correlation between FUT7 expression and FUT7 methylation level was observed, among which FUT7 expression was positively correlated with the abundance of 28 kinds of tumor-infiltrating lymphocytes (TILs), while FUT7 methylation level was negatively correlated with TILs.

Conclusion

Altogether, these findings suggested that FUT7 possessed the potential to serve as a detection biomarker or immunotherapeutic target for BLCA.

Immunopositivity for Siglec-15 in gastric cancer and its association with clinical and pathological parameters

The sialic acid-binding immunoglobulin-type lectin Siglec-15 is a promising target for cancer immunotherapy in several tumor types. The present study aimed to investigate Siglec-15 expression in gastric cancer (GC) patient tissues and to evaluate its clinical value. Siglec-15 expression was evaluated by immunohistochemistry in 71 patients. Siglec-15 staining was observed in tumor cells of 53 (74.64%) patients, with significant association with histologic classification and angiolymphatic invasion (p<0.05). Immunohistochemistry analysis also detected Siglec-15 in tumor-associated stroma cells (macrophages/myeloid cells). There was no significant association with outcome parameters. Siglec-15 expression in well differentiated histological GC tissues and in the tumor microenvironment are potential targets to be further investigated as a novel prognostic factor for GC.

CHPF promotes malignancy of breast cancer cells by modifying syndecan-4 and the tumor microenvironment

Breast cancer is the leading cause of cancer-related deaths in women worldwide. Several studies have indicated that abnormal chondroitin sulfate (CS) chains accumulate in breast cancer tissues; however, the functions and dysregulation of CS synthases are largely unknown. Here, we demonstrate that chondroitin polymerising factor (CHPF) is frequently upregulated in breast cancer tissues and that its high expression is positively associated with tumor metastasis, high stages, and short survival time. CHPF modulates CS formation in breast cancer cells. Additionally, we found that CHPF promotes tumor growth and metastasis accompanied by an increase in G-CSF levels and the number of myeloid-derived suppressor cells in tumor tissue. We revealed that tumor cell-derived G-CSF is co-localised with CS on the cell surface. Interestingly, our study is the first to identify that syndecan-4 (SDC4) is modified by CHPF and that it is involved in CHPF-mediated phenotypes. Moreover, breast cancer patients with high expression of both SDC4 and CHPF had worse overall survival compared to other subsets, which implied the synergistic effects of these two genes. In summary, our results indicated that the upregulation of CHPF in breast cancer contributes to the malignant behaviour of cancer cells, thereby providing novel insights on the significance of CHPF-modified SDC4 in breast cancer pathogenesis.