Overexpression of vascular adhesion protein-1 is associated with poor prognosis of astrocytomas

Serum vascular adhesion protein-1 is associated with twelve-year risk of incident cancer, cancer mortality, and all-cause mortality: a community-based cohort study

Background

Vascular adhesion protein-1 (VAP-1), a dual-function glycoprotein, has been reported to play a crucial role in inflammation and tumor progression. We conducted a community-based cohort study to investigate whether serum VAP-1 could be a potential biomarker for predicting incident cancers and mortality.

Method

From 2006 to 2018, we enrolled 889 cancer-free subjects at baseline. Serum VAP-1 levels were measured using a time-resolved immunofluorometric assay. Cancer and vital status of the participants were obtained by linking records with the computerized cancer registry and death certificates in Taiwan.

Results

During a median follow-up of 11.94 years, 69 subjects developed incident cancers and 66 subjects died, including 29 subjects who died from malignancy. Subjects in the highest tertile of serum VAP-1 had a significantly higher risk of cancer incidence (p=0.0006), cancer mortality (p=0.0001), and all-cause mortality (p=0.0002) than subjects in the other tertiles. The adjusted hazard ratios per one standard deviation increase in serum VAP-1 concentrations were 1.28 for cancer incidence (95% CI=1.01-1.62), 1.60 for cancer mortality (95% CI=1.14-2.23), and 1.38 for all-cause mortality (95% CI=1.09-1.75). The predictive performance of serum VAP-1 was better than that of gender, smoking, body mass index, hypertension, diabetes, and estimated glomerular filtration rate but lower than that of age for cancer incidence, cancer mortality, and all-cause mortality, as evidenced by higher increments in concordance statistics and area under the receiver operating characteristic curve.

Conclusion

Serum VAP-1 levels are associated with a 12-year risk of incident cancer, cancer mortality, and all-cause mortality in a general population.

A Prognostic Model Based on Metabolism-Related Genes for Patients with Ovarian Cancer

Metabolism-associated genes (MAGs) are important regulators of tumor progression and can affect a variety of physiological processes. In this study, we focused on the relationship between MAGs and Ovarian cancer (OC) prognosis.

METHOD

Metabolism-related genes were extracted from the Cancer Genome Atlas (TCGA) database. Through univariate COX and lasso regression models, a dynamic risk model based on MAGs was established. Compared with other clinical factors, demonstrated the ability of the model to predict the prognosis of patients with OC. The clinical samples were used to verify the expression of these MAGs.

RESULTS

A metabolism-associated gene signature was constructed by LASSO Cox regression analysis in OC, which was composed of 3-MAGs (PTGIS, AOC3, and IDO1). The signature was used to classify the OC patients into high-risk and low-risk groups. The overall survival of the low-risk group was significantly better than that of the high-risk group. The analysis of the therapeutic effect of bevacizumab showed that bevacizumab was not conducive to improving the prognosis of the low-risk group.

CONCLUSIONS

We constructed a prognostic model of MAGs in OC, which can be used to predict the prognosis of OC patients and may have a good guiding significance in the individualized treatment of patients.

Vascular adhesion protein-1 (VAP-1) in vascular inflammatory diseases

Summary: Vascular adhesion protein-1 (VAP-1) also known as amino oxidase copper containing 3 (AOC3) is a pro-inflammatory and versatile molecule with adhesive and enzymatic properties. VAP-1 is a primary amine oxidase belonging to the semicarbazide-sensitive amine oxidase (SSAO) family, which catalyzes the oxidation of primary amines leading to the production of ammonium, formaldehyde, methylglyoxal, and hydrogen peroxide. VAP-1 is mainly expressed by endothelial cells, smooth muscle cells, adipocytes and pericytes. It is involved in a repertoire of biological functions, e.g., immune cell extravasation, angiogenesis, and vascularization. Research into VAP-1 has intensified within the last decade on its role as a novel clinical biomarker and as a potential therapeutic target of vascular inflammatory disorders such as atherosclerosis, stroke, diabetes, neurovascular disorders (e.g., Alzheimer’s Disease), hepatic disease (e.g., non-alcoholic steatohepatitis), and skin conditions (e.g., psoriasis). This is the most up-to-date and comprehensive review on VAP-1 focusing on the translational aspects of VAP-1. Compared to recent reviews, our review provides novel insights on VAP-1 and heart failure, stroke and frailty, diabetes, endometriosis, osteoarthritis, COVID-19, conjunctivitis associated systemic lupus erythematosus, hematopoietic stem cells, gliomas, treatment of colorectal cancer with a novel VAP-1 inhibitor (U-V269), promoting recovery of motor functions and habit learning with a novel VAP-1 inhibitor (PXS-4681A), and 68Ga-DOTA-Siglec-9, a labelled peptide of Siglec-9 (a VAP-1 ligand), which appears to be a safe PET tracer for inflammation in rheumatoid arthritis. Finally, we present the emerging role of VAP-1 in pregnancy as a gatekeeper of immune cells, which are critical for spiral arterial remodeling, the deficiency of which could lead to vascular disorders of pregnancy such as preeclampsia. Future research should prioritize clinical trials on VAP-1 small-molecule inhibitors and monoclonal antibodies, thus, maximizing the potential of VAP-1 targeted therapy as well as research into sVAP-1 as a clinical biomarker of diseases and its prognosis.

Amine oxidase, copper containing 3 exerts anti‑mesenchymal transformation and enhances CD4+ T‑cell recruitment to prolong survival in lung cancer

Lung cancer remains notorious for its poor prognosis. Despite the advent of tyrosine kinase inhibitors and immune checkpoint inhibitors, the probability of curing the disease in lung cancer patients remains low. Novel mechanisms and treatment strategies are needed to provide hope to patients. Advanced strategies of next generation sequencing (NGS) and bioinformatics were used to analyze normal and lung cancer tissues from lung cancer patients. Amine oxidases have been linked to leukocyte migration and tumorigenesis. However, the roles of amine oxidases in lung cancer are not well-understood. Our results indicated that amine oxidase, copper containing 3 (AOC3) was significantly decreased in the tumor tissue compared with the normal tissue, at both the mRNA and protein level, in the included lung cancer patients and public databases. Lower expression of AOC3 conferred a poorer survival probability across the different cohorts. Epigenetic silencing of AOC3 via miR-3691-5p caused tumor promotion and progression by increasing migration and epithelial-mesenchymal transition (EMT). Furthermore, knockdown of AOC3 caused less CD4⁺ T-cell attachment onto lung cancer cells and reduced transendothelial migration in vitro, as well as reducing CD4⁺ T-cell trafficking to the lung in vivo. In conclusion, the present study revealed that downregulation of AOC3 mediated lung cancer promotion and progression, as well as decrease of immune cell recruitment. This novel finding could expand our understanding of the dysregulation of the tumor immune microenvironment and could help to develop a novel strategy for the treatment of lung cancer.

SSAO/VAP-1 in Cerebrovascular Disorders: A Potential Therapeutic Target for Stroke and Alzheimer's Disease

The semicarbazide-sensitive amine oxidase (SSAO), also known as vascular adhesion protein-1 (VAP-1) or primary amine oxidase (PrAO), is a deaminating enzyme highly expressed in vessels that generates harmful products as a result of its enzymatic activity. As a multifunctional enzyme, it is also involved in inflammation through its ability to bind and promote the transmigration of circulating leukocytes into inflamed tissues. Inflammation is present in different systemic and cerebral diseases, including stroke and Alzheimer’s disease (AD). These pathologies show important affectations on cerebral vessels, together with increased SSAO levels. This review summarizes the main roles of SSAO/VAP-1 in human physiology and pathophysiology and discusses the mechanisms by which it can affect the onset and progression of both stroke and AD. As there is an evident interrelationship between stroke and AD, basically through the vascular system dysfunction, the possibility that SSAO/VAP-1 could be involved in the transition between these two pathologies is suggested. Hence, its inhibition is proposed to be an interesting therapeutical approach to the brain damage induced in these both cerebral pathologies.

Increased Vascular Adhesion Protein 1 (VAP-1) Levels are Associated with Alternative M2 Macrophage Activation and Poor Prognosis for Human Gliomas

Glioma is characterized by a high heterogeneity in the brain tumor. Abundant tumor-associated macrophages (TAMs) exist as neoplastic tissues, implicating tumor plasticity and thus leading to therapeutic challenges. Vascular adhesion protein (VAP-1) potentially serves as a mediator for TAM immunity in tumor milieu. We previously demonstrated that VAP-1 could contribute to tumor malignancy, but its characteristics in TAM immunity of glioma progression are still unclear. This study explored the association of VAP-1 expression with TAM distribution as well as the resulting clinical significance and prognostic value in human gliomas. An in-depth analysis of AOC3 (VAP-1) gene expression was performed using 695 glioma samples derived from the cancer genome atlas (TCGA)-lower grade glioma and glioblastoma (GBMLGG) cohort. Bioinformatic analysis confirmed that VAP-1 expression is associated with poor prognosis of glioma patients (p = 0.0283). VAP-1 and TAM biomarkers (CD68, iNOS, and CD163) were evaluated by immunohistochemistry in 108 gliomas from Kaohsiung Medical University Hospital. VAP-1+ was expressed in 56 (51.85%) cases and this phenotype revealed a significant association with overall survival in Kaplan–Meier analysis (p < 0.0001). Immunohistochemical double staining showed that VAP-1 immunoreactivity was present around CD163+ M2 infiltration location, including aggressive lesions and neighboring neovasculature. We demonstrated that high VAP-1 expression levels positively correlated with CD163+ M2 activation and coexpression of these two proteins was associated with worse survival in gliomas (p < 0.0001). Multivariate analysis indicated that VAP-1 alone and co-expressed with CD163 were the significantly independent indicators (both p < 0.0001). Furthermore, VAP-1/CD163 coexpression exhibited excellent diagnostic accuracy in gliomas (AUC = 0.8008). In conclusion, VAP-1 and TAM CD163 M2 coexpression was found in glioma tissues belonging to a highly malignant subgroup that was associated with poor prognosis. These results implied VAP-1 abundance is closely linked to alternative M2 activation during glioma progression. From the aforementioned data, a reasonable inference is that VAP-1 combined with targeting M2 immunity might be an effective therapeutic target for human gliomas.

Global serum proteomic changes in water buffaloes infected with Fasciola gigantica

BACKGROUND

The liver fluke Fasciola gigantica modulates several signaling pathways in infected buffaloes to facilitate its survival and establishment of persistent infection. In response to the parasite invasion, buffaloes activate innate and adaptive immune responses to counter the parasite infection. To detect new proteins that might be involved in the interaction between F. gigantica and the buffaloes, and that also might serve as biomarkers for fasciolosis, we used proteomic techniques to study the serum proteome of buffaloes during F. gigantica infection. Here, we used an isobaric tags for relative and absolute quantitation (iTRAQ)-based quantitative proteomic approach to identify serum proteins that are differentially expressed in infected buffaloes compared to uninfected control buffaloes. Additionally, we applied a parallel reaction monitoring (PRM) assay to validate specific proteins identified by the iTRAQ method.

RESULTS

A total of 313, 459 and 399 proteins were identified at 3, 42 and 70 days post-infection, respectively; of these 92, 93 and 138 were differentially abundant proteins. Some of the identified differentially abundant proteins, including complement factor H related 5, complement component C6, complement component C7, amine oxidase, plasma serine protease inhibitor and lysozyme, are known to be involved in complement system activation, blood coagulation, platelet activation, lymphocyte's adhesion and lysozyme hydrolysis. Analysis of data for all three time points after infection identified six significantly upregulated proteins in infected serum that separated infected and uninfected buffaloes into distinct clusters. Further PRM analysis confirmed the expression of five proteins, namely MHC class I antigen, Beta-2-microglobulin, NID2 protein, Fetuin-B and Fibrinogen gamma-B chain.

CONCLUSIONS

These findings provide novel insights into the serum proteomics signature of buffaloes during F. gigantica infection.

Vascular adhesion protein-1 as indicator of breast cancer tumor aggressiveness and invasiveness

Recent studies suggest that vascular adhesion protein-1 (VAP-1), a 180-KDa homodimeric glycoprotein, may be associated with cancer-related events including tumor cell migration, motility, invasion, or metastasis. Therefore, this study applies VAP-1 immunohistochemical staining to demonstrate the invasiveness component of the breast cancer. The VAP-1 staining results were compared in 148 breast cancer cases to identify possible correlations with clinical status, including age, tumor size, tumor grade, TNM stage, lymphatic invasion, metastasis, recurrence, and survival rate. Immunohistochemical staining results showed VAP-1 negative or weak staining in normal ducts and ductal carcinoma in situ (DCIS), but these phenotypes were positively associated with a stiffened VAP-1 that presented at the invasive front of the lesion. Our data demonstrated that VAP-1 expression was positively associated with lymphatic invasion, distant metastasis, and patient survival in breast carcinoma. Notably, VAP-1 expression was found to be significantly correlated with the overall survival (p < 0.0001). Multivariate Cox analysis indicated that VAP-1 expression was a significant independent prognostic indicator of overall survival in breast carcinoma (p < 0.0001). In conclusion, this study suggests that VAP-1 is linked to progression of tumor invasion and metastasis in breast carcinoma. VAP-1 is shown to be a biomarker that can be predict invasive potential and clinical outcome in breast cancer.

Site-specific expression of amine oxidases in breast cancer metastases

We aimed to evaluate the expression of amine oxidase-related proteins in metastatic breast cancer tissue and determine its clinical implication. A tissue microarray was constructed from a total of 126 metastatic breast tumors (31 bone metastases (24.6%), 36 brain metastases (28.6%), 11 liver metastases (8.7%), and 48 lung metastases (38.1%)). Immunohistochemical staining for amine oxidase-related proteins (lysyl oxidase, diamine oxidase, and monoamine oxidase A and B) was performed. In metastatic breast cancer tissue, lysyl oxidase ( p = 0.001), tumoral diamine oxidase ( p = 0.003), stromal diamine oxidase ( p = 0.047), and stromal monoamine oxidase B ( p = 0.002) were differentially expressed in different metastatic sites. Bone metastases showed low expression of lysyl oxidase, tumoral diamine oxidase, and stromal diamine oxidase. We observed high expression of lysyl oxidase in brain metastases, tumoral diamine oxidase in liver metastases, stromal diamine oxidase in lung metastases, and stromal monoamine oxidase B in bone metastases. Lysyl oxidase positivity was associated with progesterone receptor negativity ( p = 0.001), and monoamine oxidase A positivity was associated with human epidermal growth factor receptor-2 negativity ( p = 0.003) and the luminal A subtype ( p = 0.003). On univariate analysis shorter overall survival was associated with stromal diamine oxidase negativity ( p = 0.008), especially in lung metastases ( p = 0.025), and stromal monoamine oxidase B positivity ( p < 0.001). Stromal monoamine oxidase B positivity was an independent prognostic factor for shorter overall survival in multivariate Cox analysis (hazard ratio, 4.069; 95% confidence interval, 1.649–10.04; p = 0.002). Finally, in metastatic breast cancer, amine oxidase-related proteins were differentially expressed in a manner specific to metastatic site, and stromal monoamine oxidase B expression was correlated with prognosis.

Proteolytic cleavage of vascular adhesion protein-1 induced by vascular endothelial growth factor in retinal capillary endothelial cells

PURPOSE

To investigate the mechanism of soluble vascular adhesion protein-1 (sVAP-1) accumulation induced by vascular endothelial growth factor (VEGF) in the vitreous of patients with diabetic retinopathy (DR).

STUDY DESIGN

Experimental.

METHODS

Protein levels of sVAP-1 and N epsilon-(hexanoyl)lysine (HEL), an oxidative stress marker, in the vitreous samples from patients with proliferative diabetic retinopathy (PDR) with or without intravitreal bevacizumab (IVB) injection were determined by ELISA. The effect of VEGF on both mRNA expression of Vap-1 and secretion of sVAP-1 in rat retinal capillary endothelial cells (TR-iBRB2) was analyzed by real-time PCR and western blotting, respectively. In addition, the impact of VEGF on production and activation ratios of matrix metalloproteinase (MMP)-2 and MMP-9 was examined by gelatin zymography. Hydrogen peroxide production and reactive oxygen species (ROS) levels were assessed in the supernatants of TR-iBRB2 cells treated with VEGF.

RESULTS

IVB injection decreased vitreous levels of sVAP-1 and HEL in patients with PDR. VEGF stimulation released sVAP-1 protein from TR-iBRB2 cells as a consequence of membrane-anchored VAP-1 shedding by MMP-2 and MMP-9. In addition, VEGF increased hydrogen peroxide generation and ROS augmentation through spermine oxidation by sVAP-1 as semicarbazide-sensitive amine oxidase (SSAO) in the supernatant of cultured endothelial cells.

CONCLUSIONS

The current data demonstrate that proangiogenic factor VEGF induces sVAP-1 release from retinal capillary endothelial cells and facilitates hydrogen peroxide generation via enzymatic property of sVAP-1, followed by the increase of oxidative stress, one of the crucial factors in the pathogenesis of DR.

Evaluation of the Expression of Amine Oxidase Proteins in Breast Cancer

We aimed to evaluate the expression of amine oxidase proteins in breast cancer and their clinical implications. We performed immunohistochemical staining of amine oxidase proteins (LOX, lysyl oxidase, AOC3, amine oxidase, MAOA, monoamine oxidase A, MAOB, monoamine oxidase B). Based on their hormone receptors, such as estrogen receptor (ER) and progesterone receptor (PR), human epidermal growth factor receptor 2 (HER-2), and Ki-67 immunohistochemical staining, breast cancer was divided into four molecular subtypes: luminal A, luminal B, HER-2 type, and triple-negative breast cancer (TNBC). Luminal A was observed in 380 cases (49.4%), luminal B in 224 (29.1%), HER-2 type in 68 (8.8%), and TNBC in 98 (12.7%). Stromal AOC3, MAO-A, and MAO-B expression varied according to molecular subtypes. Stromal AOC3 expression was high in luminal B and HER-2 type and MAO-A expression was high in luminal A and luminal B (p < 0.001). MAO-B expression was higher in TNBC than in other subtypes (p = 0.020). LOX positivity was associated with high histological grade (p < 0.001) and high Ki-67 labeling index (LI) (p = 0.009), and stromal AOC3 positivity was associated with high histological grade (p = 0.001), high Ki-67 LI (p < 0.001), and HER-2 positivity (p = 0.002). MAO-A positivity was related to low histological grade (p < 0.001), ER positivity, PR positivity (p < 0.001), and low Ki-67 LI (p < 0.001). In univariate analysis, MAO-A positivity was related to short disease-free survival in HER-2 type (p = 0.013), AOC3 negativity was related to short disease-free survival and overall survival in ER-positive breast cancer, PR-positive breast cancer, HER-2-negative breast cancer, and lymph node metastasis. In conclusion, the expression of amine oxidase proteins varies depending on the molecular subtype of breast cancer. Stromal AOC3 expression was high in luminal B and HER-2 type, and MAO-A expression was high in luminal A and luminal B.

CCAAT/enhancer binding protein β negatively regulates progesterone receptor expression in human glioblastoma cells

Many progesterone (P4) actions are mediated by its intracellular receptor (PR), which has two isoforms (PR-A and PR-B) differentially transcribed from separate promoters of a single gene. In glioblastomas, the most frequent and aggressive brain tumors, PR-B is the predominant isoform. In an in silico analysis we showed putative CCAAT/Enhancer Binding Protein (C/EBP) binding sites at PR-B promoter. We evaluated the role of C/EBPβ in PR-B expression regulation in glioblastoma cell lines, which expressed different ratios of PR and C/EBPβ isoforms (LAP1, LAP2, and LIP). ChIP assays showed a significant basal binding of C/EBPβ, specific protein 1 (Sp1) and estrogen receptor alpha (ERα) to PR-B promoter. C/EBPβ knockdown increased PR-B expression and treatment with estradiol (E2) reduced C/EBPβ binding to the promoter and up-regulated PR-B expression. P4 induced genes were differently regulated when CEBP/β was silenced. These data show that C/EBPβ negatively regulates PR-B expression in glioblastoma cells.

Testin (TES) as a candidate tumour suppressor and prognostic marker in human astrocytoma

Astrocytomas are one of the most common brain tumours; however, the current methods used to characterize these tumours are inadequate. The establishment of molecular markers may identify variables required to improve tumour characterization and subtyping, and may aid to specify targets for improved treatment with essential prognostic value for patient survival. One such candidate is testin (TES), which was reported to have prognostic value for glioblastoma patients. However, the role of TES protein in gliomagenesis is currently unknown. In the present study, the methylation status of the TES promoter was investigated in post-operative astrocytoma tumours of different malignancy grade, and its association with the survival of astrocytoma patients was evaluated. In addition, the expression of TES protein was investigated in the same set of astrocytoma tumours tissue, and the association of protein expression with glioma patients survival was evaluated. The methylation status of TES was assessed by methylation-specific polymerase chain reaction in 138 different grade astrocytoma samples. Western blot analysis was used to characterize the expression pattern of TES in 86 different grade astrocytoma specimens: 13 of pathological grade I, 31 of pathological grade II, 17 of pathological grade III and 25 of pathological grade IV (glioblastoma). Statistical analyses were conducted to investigate the association between tumour molecular pattern, patient clinical variables and overall survival. The methylation analysis of the TES promoter exhibited a distinct profile between astrocytomas of different malignancy grade (P<0.001). Furthermore, gene promoter methylation was significantly associated with patients' age, survival and pathological grade (P<0.001). The protein expression level of TES was significantly lower in glioblastoma (grade IV astrocytoma) than in lower grade (II–III) astrocytoma tissue (P=0.028 and P=0.04, respectively). Additionally, short overall survival of patients was markedly associated with low TES protein expression (P=0.007). However, no association between TES methylation and TES protein expression was noticed. The present study demonstrated that decreased expression of TES may be important in tumour progression and prognosis in human astrocytomas. TES may be a useful marker for predicting the clinical outcome of astrocytoma patients.