Dll4-Notch signaling in regulation of tumor angiogenesis

Innovating Cancer Treatment Through Cell Cycle, Telomerase, Angiogenesis, and Metastasis

Cancer remains a formidable challenge in the field of medicine, necessitating innovative therapeutic strategies to combat its relentless progression. The cell cycle, a tightly regulated process governing cell growth and division, plays a pivotal role in cancer development. Dysregulation of the cell cycle allows cancer cells to proliferate uncontrollably. Therapeutic interventions designed to disrupt the cell cycle offer promise in restraining tumor growth and progression. Telomerase, an enzyme responsible for maintaining telomere length, is often overactive in cancer cells, conferring them with immortality. Targeting telomerase presents an opportunity to limit the replicative potential of cancer cells and hinder tumor growth. Angiogenesis, the formation of new blood vessels, is essential for tumor growth and metastasis. Strategies aimed at inhibiting angiogenesis seek to deprive tumors of their vital blood supply, thereby impeding their progression. Metastasis, the spread of cancer cells from the primary tumor to distant sites, is a major challenge in cancer therapy. Research efforts are focused on understanding the underlying mechanisms of metastasis and developing interventions to disrupt this deadly process. This review provides a glimpse into the multifaceted approach to cancer therapy, addressing critical aspects of cancer biology-cell cycle regulation, telomerase activity, angiogenesis, and metastasis. Through ongoing research and innovative strategies, the field of oncology continues to advance, offering new hope for improved treatment outcomes and enhanced quality of life for cancer patients.

Metabolic reprogramming and interventions in angiogenesis

BACKGROUND

Endothelial cell (EC) metabolism plays a crucial role in the process of angiogenesis. Intrinsic metabolic events such as glycolysis, fatty acid oxidation, and glutamine metabolism, support secure vascular migration and proliferation, energy and biomass production, as well as redox homeostasis maintenance during vessel formation. Nevertheless, perturbation of EC metabolism instigates vascular dysregulation-associated diseases, especially cancer.

AIM OF REVIEW

In this review, we aim to discuss the metabolic regulation of angiogenesis by EC metabolites and metabolic enzymes, as well as prospect the possible therapeutic opportunities and strategies targeting EC metabolism.

KEY SCIENTIFIC CONCEPTS OF REVIEW

In this work, we discuss various aspects of EC metabolism considering normal and diseased vasculature. Of relevance, we highlight that the implications of EC metabolism-targeted intervention (chiefly by metabolic enzymes or metabolites) could be harnessed in orchestrating a spectrum of pathological angiogenesis-associated diseases.

Novel insights into Notch signaling in tumor immunity: potential targets for cancer immunotherapy

Notch signaling pathway is a highly conserved system of cell-to-cell communication that participates in various biological processes, such as stem cell maintenance, cell fate decision, cell proliferation and death during homeostasis and development. Dysregulation of Notch signaling has been associated with many aspects of cancer biology, such as maintenance of cancer stem-like cells (CSCs), cancer cell metabolism, angiogenesis and tumor immunity. Particularly, Notch signaling can regulate antitumor or pro-tumor immune cells within the tumor microenvironment (TME). Currently, Notch signaling has drawn significant attention in the therapeutic development of cancer treatment. In this review, we focus on the role of Notch signaling pathway in remodeling tumor immune microenvironment. We describe the impact of Notch signaling on the efficacy of cancer immunotherapies. Furthermore, we summarize the results of relevant preclinical and clinical trials of Notch-targeted therapeutics and discuss the challenges in their clinical application in cancer therapy. An improved understanding of the involvement of Notch signaling in tumor immunity will open the door to new options in cancer immunotherapy treatment.

Metastasis and cancer associated fibroblasts: taking it up a NOTCH

Metastasis is the least understood aspect of cancer biology. 90% of cancer related deaths occur due extensive metastatic burden in patients. Apart from metastasizing cancer cells, the pro-tumorigenic and pro-metastatic role of the tumor stroma plays a crucial part in this complex process often leading to disease relapse and therapy resistance. Cellular signaling processes play a crucial role in the process of tumorigenesis and metastasis when aberrantly turned on, not just in the cancer cells, but also in the cells of the tumor microenvironment (TME). One of the most conserved pathways includes the Notch signaling pathway that plays a crucial role in the development and progression of many cancers. In addition to its well documented role in cancer cells, recent evidence suggests crucial involvement of Notch signaling in the stroma as well. This review aims to highlight the current findings focusing on the oncogenic role of notch signaling in cancer cells and the TME, with a specific focus on cancer associated fibroblasts (CAFs), which constitute a major part of the tumor stroma and are important for tumor progression. Recent efforts have focused on the development of anti-cancer and anti-metastatic therapies targeting TME. Understanding the importance of Notch signaling in the TME would help identify important drivers for stromal reprogramming, metastasis and importantly, drive future research in the effort to develop TME-targeted therapies utilizing Notch.

AGEs induce high expression of Dll4 via endoplasmic reticulum stress PERK signaling-mediated internal ribosomal entry site mechanism in macrophages

Background and aim

Advanced glycation end products (AGEs)- exposed macrophages was characterized by Delta-like ligand 4 (Dll4) high expressed and has been shown to participate in diabetes-related atherosclerosis. This study was aimed to investigate the translational regulatory mechanism of Dll4 high expression in macrophages exposed to AGEs.

Methods

Human Dll4 5' untranslated region (5'UTR) sequence was cloned and inserted into a bicistronic reporter plasmid. Human THP-1 macrophages transfected with the bicistronic reporter plasmids were exposed to AGEs. Dual-luciferase assay was used to detect internal ribosome entry site (IRES) activity contained in Dll4 5'UTR. Small interference RNA transfection was used to knock-down specific gene expression. Localization of protein was analyzed.

Results

AGEs exposure significantly induced IRES activity in Dll4 5' UTR in human macrophages. Internal potential promoter and ribosome read-through mechanisms were excluded. Inhibition of endoplasmic reticulum stress and specific silencing of protein kinase R-like endoplasmic reticulum kinase (PERK)/eukaryotic initiation factor 2α (eIF2α) signaling pathway activation reduced IRES activity in Dll4 5' UTR in human macrophages. Dll4 5' UTR IRES activity was also inhibited by targeted silencing of heterogeneous nuclear ribonucleoprotein A1 (hnRNPA1). Moreover, specific inhibition of PERK/eIF2α signaling pathway led to deactivation of hnRNPA1, resulting to reduction of AGEs- induced Dll4 5' UTR IRES activity in human macrophages.

Conclusions

AGEs induced Dll4 5' UTR IRES activity in human macrophages which was dependent on endoplasmic reticulum stress PERK/eIF2α signaling pathway. hnRNPA1 acted the role as an ITAF was also indispensable for AGEs-induced Dll4 5'UTR IRES activity in human macrophages.

ZLDI-8 suppresses angiogenesis and vasculogenic mimicry in drug-resistant NSCLC in vitro and in vivo

AIMS

The chemotherapy drugs for NSCLC often face the consequences of treatment failure due to acquired drug resistance. Tumor chemotherapy resistance is often accompanied by angiogenesis. Here, we aimed to investigate the effect and underlying mechanisms of ADAM-17 inhibitor ZLDI-8 we found before on angiogenesis and vasculogenic mimicry(VM) in drug-resistant NSCLC.

MAIN METHODS

The tube formation assay was used to evaluate angiogenesis and VM. Migration and invasion were assessed with transwell assays in the co-culture condition. To explore the underlying mechanisms of how ZLDI-8 inhibited tubes formation, ELISA assay and western blot assay were preformed. The effects of ZLDI-8 on angiogenesis in vivo were investigated in Matrigel plug, CAM and Rat aortic ring assays.

KEY FINDINGS

In the present study, ZLDI-8 significantly inhibited the tube formation of human umbilical vein endothelial cells (HUVECs) in either normal medium or in tumor supernatants. Furthermore, ZLDI-8 also inhibited VM tubes formation of A549/Taxol cells. In the co-culture assay, the interaction between lung cancer cells and HUVECs promotes increased cell migration and invasion, while ZLDI-8 eliminates this promotion. Moreover, the VEGF secretion were decreased by ZLDI-8 and the expression of Notch1, Dll4, HIF1α and VEGF were inhibited by ZLDI-8. In addition, ZLDI-8 can inhibit blood vessel formation in the Matrigel plug, CAM and Rat aortic ring assays.

SIGNIFICANCE

ZLDI-8 inhibits angiogenesis and VM in drug-resistant NSCLC through suppressing Notch1-HIF1α-VEGF signaling pathway. This study lays the foundation for the discovery of drugs that inhibit angiogenesis and VM in drug resistant NSCLC.

Anti-angiogenic effects of aqueous extract from Agrostemma githago L. seed in human umbilical vein endothelial cells via regulating Notch/VEGF, MMP2/9, ANG2, and VEGFR2

Abnormal angiogenesis contributes to the pathogenesis of various diseases. The medicinal usage of Agrostemma githago L. seed (A. githago herein) has been stated in traditional medicine. This study aims to investigate the anti-angiogenic potential of aqueous extract of A. githago. In order to test the effect of A. githago extract, its impact on HUVECs, T98G, and HGF2PI2 cells was assessed by looking at cellular viability, changes in the distribution of cells in different phases of the cell cycle, induction of oxidative stress, and apoptosis. In addition, the release of VEGF, ANG2, and MMP2/9 factors, along with the expressions of the critical Notch signaling pathway players and VEGF receptors (VEGFR), was measured. Furthermore, a γ-secretase inhibitor (LY411575) was applied to determine whether Notch inhibition restores A. githago effects. As a further characterization, total phenolic and flavonoid contents of A. githago were estimated, and five triterpene saponin compounds were identified using LC-ESI-MS. In response to A. githago extract, a reduction in total cell viability, along with the induction of ROS and apoptosis, was detected. Exposure to the A. githago extract could modulate the release of VEGF and ANG2 from T98G and HUVECs, respectively. In addition, A. githago reduced the release of MMP2/9. Furthermore, Notch1, DLL4, and HEY2 transcripts and protein expressions were up-regulated, while VEGFR2 was down-regulated in treated HUVEC cells. Treatment with the A. githago extract resulted in a dose-dependent inhibition of AKT phosphorylation. Inhibition of Notch signaling retrieved the viability loss, reduced intracellular ROS, and alleviated the impaired tube formation in A. githago-treated HUVECs. Overall, these data underscore the anti-angiogenic potential of A. githago via inducing apoptosis, modifying the expression levels of VEGF/VEGFR2, and impacting the release of MMP2/9 and ANG2, effects that are most probably modulated through the Notch/VEGF signaling axis.

A concise review of VEGF, PDGF, FGF, Notch, angiopoietin, and HGF signalling in tumor angiogenesis with a focus on alternative approaches and future directions

Angiogenesis forms new vessels from existing ones. Abnormal angiogenesis, which is what gives tumor microenvironments their distinctive features, is characterised by convoluted, permeable blood vessels with a variety of shapes and high perfusion efficiency. Tumor angiogenesis controls cancer growth by allowing invasion and metastasis and is highly controlled by signalling networks. Therapeutic techniques targeting VEGF, PDGF, FGF Notch, Angiopoietin, and HGF signalling restrict the tumor's vascular supply. Numerous pathways regulate angiogenesis, and when one of those processes is blocked, the other pathways may step in to help. VEGF signalling inhibition alone has limits as an antiangiogenic therapy, and additional angiogenic pathways such as FGF, PDGF, Notch, angiopoietin, and HGF are important. For the treatment of advanced solid tumors, there are also new, emerging medicines that target multiple angiogenic pathways. Recent therapies block numerous signalling channels concurrently. This study focuses on 'alternative' methods to standard antiangiogenic medicines, such as cyclooxygenase-2 blocking, oligonucleotide binding complementary sites to noncoding RNAs to regulate mRNA target, matrix metalloproteinase inhibition and CRISPR/Cas9 based gene edition and dissecting alternative angiogenesis mechanism in tumor microenvironment.

Notch signaling in female cancers: a multifaceted node to overcome drug resistance

Drug resistance is one of the main challenges in cancer therapy, including in the treatment of female-specific malignancies, which account for more than 60% of cancer cases among women. Therefore, elucidating the underlying molecular mechanisms is an urgent need in gynecological cancers to foster novel therapeutic approaches. Notably, Notch signaling, including either receptors or ligands, has emerged as a promising candidate given its multifaceted role in almost all of the hallmarks of cancer. Concerning the connection between Notch pathway and drug resistance in the afore-mentioned tumor contexts, several studies focused on the Notch-dependent regulation of the cancer stem cell (CSC) subpopulation or the induction of the epithelial-to-mesenchymal transition (EMT), both features implicated in either intrinsic or acquired resistance. Indeed, the present review provides an up-to-date overview of the published results on Notch signaling and EMT- or CSC-driven drug resistance. Moreover, other drug resistance-related mechanisms are examined such as the involvement of the Notch pathway in drug efflux and tumor microenvironment. Collectively, there is a long way to go before every facet will be fully understood; nevertheless, some small pieces are falling neatly into place. Overall, the main aim of this review is to provide strong evidence in support of Notch signaling inhibition as an effective strategy to evade or reverse resistance in female-specific cancers.

Splicing deregulation, microRNA and Notch aberrations: fighting the three-headed dog to overcome drug resistance in malignant mesothelioma

INTRODUCTION

Malignant mesothelioma (MMe) is an aggressive rare cancer of the mesothelium, associated with asbestos exposure. MMe is currently an incurable disease at all stages mainly due to resistance to treatments. It is therefore necessary to elucidate key mechanisms underlying chemoresistance, in an effort to exploit them as novel therapeutic targets.

AREAS COVERED

Chemoresistance is frequently elicited by microRNA (miRNA) alterations and splicing deregulations. Indeed, several miRNAs, such as miR-29c, have been shown to exert oncogenic or oncosuppressive activity. Alterations in the splicing machinery might also be involved in chemoresistance. Moreover, the Notch signaling pathway, often deregulated in MMe, plays a key role in cancer stem cells formation and self-renewal, leading to drug resistance and relapses.

EXPERT OPINION

The prognosis of MMe in patients varies among different tumors and patient characteristics, and novel biomarkers and therapies are warranted. This work aims at giving an overview of MMe, with a special focus on state-of-the-art treatments and new therapeutic strategies against vulnerabilities emerging from studies on epigenetics factors. Besides, this review is also the first to discuss the interplay between miRNAs and alternative splicing as well as the role of Notch as new promising frontiers to overcome drug resistance in MMe.

The Prognostic Role and Significance of Dll4 and Toll-like Receptors in Cancer Development

Simple Summary

The aim of this review is to summarize the latest details considering the role of Dll4 in cancer, since recent data report that Dll4 has a major key role in tumor angiogenesis. Moreover, the authors try to seek any correlation between Dll4 and cancer stem cells in tumor development. Considering that cancer stem cells have proven to be implicated in the progression of many cancer types, any impact from Dll4 could lead to the alteration of cancer development. Additionally, the authors make a report on current advantages on immunotherapy and tumor-draining lymph nodes in cancer. Finally, this study analyzes toll like receptors, pattern recognition receptors that are capable of recognizing different molecules and activating different genes. These immunogenetic molecules have remarkable roles including angiogenesis promotion, while their activation can lead to either cancer progression or inhibition, representing a very promising therapeutic alliance for cancer treatment.

Abstract

The Notch signaling pathway regulates the development of embryonic and tissue homeostasis of various types of cells. It also controls cell proliferation, variation, fate and cell death because it emits short-range messages to nearby cells. The pathway plays an important role in the pathophysiology of various malignancies, controlling cancer creation. It also limits cancer development by adjusting preserved angiogenesis and cellular programs. One of the Notch signaling ligands (in mammals) is Delta-like ligand 4 (Dll4), which plays a significant role in the overall malignancies’ advancement. Particularly, sequencing Notch gene mutations, including those of Dll4, have been detected in many types of cancers portraying information on the growth of particular gynecological types of tumors. The current research article examines the background theory that implies the ability of Dll4 in the development of endometrial and other cancer types, and the probable therapeutic results of Dll4 inhibition.

Development of a novel miR-3648-related gene signature as a prognostic biomarker in esophageal adenocarcinoma

Background

Esophageal adenocarcinoma (EA) is a typical immunogenic malignant tumor with a dismal 5-year survival rate lower than 20%. Although miRNA-3648 (miR-3648) is expressed abnormally in EA, its impact on the tumor immune microenvironment remains unknown. In this study, we sought to identify immune-related genes (IRGs) that are targeted by miR-3648 and develop an EA multigene signature.

Methods

The gene expression data of 87 EA tumor samples and 67 normal tissue samples from The Cancer Genome Atlas (TCGA) database and the Genotype-Tissue Expression (GTEx) database were downloaded, respectively. Weighted gene co-expression network analysis (WGCNA), the CIBERSORT algorithm, and Cox regression analysis were applied to identify IRGs and to construct a prognostic signature and nomogram.

Results

MiR-3648 was expectedly highly expressed in EA tumor tissues (P=2.6e-8), and related to the infiltration of activated natural killer cells (NK cells) and activated CD4 T lymphocytes (CD4 cells). A total of 70 miR-3648-targeted genes related to immune cell infiltration were identified. Among them, 4 genes (C10orf55, DLL4, PANX2, and NKAIN1) were closely related to overall survival (OS), and were thus selected to construct a 4-gene risk score (RS). The RS had a superior capability to predict OS [area under the curve (AUC) =0.740 for 1 year; AUC =0.717 for 3 years; AUC =0.622 for 5 years]. A higher score was indicative of a poorer prognosis than a lower score [hazard ratio (HR) =2.71; 95% confidence interval (CI): 1.45-5.09; P=0.002]. Furthermore, the nomogram formed by combining the RS and the TNM classification of malignant tumors (TNM stage) improved the accuracy of survival prediction [Harrell's concordance index (C-index) =0.698].

Conclusions

MiR-3648 may play a critical role in EA pathogenesis. The novel 4-gene signature may serve as a prognostic tool to manage patients with EA.

Preliminary Research of Main Components of Dll4/ Notch-VEGF Signaling Pathway Under High-Glucose Stimulation in vitro

PURPOSE

To establish a high-glucose (HG) stressed cell model and study the expression of main components of the Dll4/Notch-VEGF signaling pathway under high-glucose stimulation.

METHODS

A model of HG-conditioned cells (human umbilical vein endothelial cells, HUVECs) was first established, and then the expression of Dll4, Notch1, Notch4 and VEGF in HG-stressed cells with or without Notch pathway blockage was analyzed by RT-PCR and Western blot. To observe cell migration, we also evaluated the Transwell assay.

RESULTS

HUVECs stimulated with 30mmol/L HG was selected as a cell model. RT-PCR and Western blot results showed that HG stimulation induced the expression of Dll4, Notch1 and VEGF and downregulated Notch4. The expressions were reversed after Notch pathway blockage; meanwhile, the blockage of Notch pathway inhibited cell migration under HG condition.

CONCLUSION

The function of Notch4 in responses to HG stimulation deserves further researching. Combination therapy by blocking Dll4/Notch and VEGF pathways may provide us with a new way for anti-neovascularization.

Three-Dimensional Culture Decreases the Angiogenic Ability of Mouse Macrophages

Macrophages play important roles in angiogenesis; however, previous studies on macrophage angiogenesis have focused on traditional 2D cultures. In this study, we established a 3D culture system for macrophages using collagen microcarriers and assessed the effect of 3D culture on their angiogenic capabilities. Macrophages grown in 3D culture displayed a significantly different morphology and arrangement under electron microscopy compared to those grown in 2D culture. Tube formation assays and chick embryo chorioallantoic membrane assays further revealed that 3D-cultured macrophages were less angiogenic than those in 2D culture. Whole-transcriptome sequencing showed that nearly 40% of genes were significantly differently expressed, including nine important angiogenic factors of which seven had been downregulated. In addition, the expression of almost all genes related to two important angiogenic pathways was decreased in 3D-cultured macrophages, including the two key angiogenic factors, VEGFA and ANG2. Together, the findings of our study improve our understanding of angiogenesis and 3D macrophage culture in tissues, and provide new avenues and methods for future research on macrophages.

Histone demethylase KDM4D inhibition suppresses renal cancer progression and angiogenesis through JAG1 signaling

Kidney cancer, especially clear cell renal cell carcinoma (ccRCC), is one of the representative genitourinary tumors. Investigation of underlying mechanisms of ccRCC development is crucial for patient management. Histone demethylase KDM4D has been reported to be responsible for development of a variety of cancers. However, the role of KDM4D in ccRCC progression is poorly understood. In our study, we performed immunohistochemistry analysis of tissue microarrays first, and results showed that high expression level of KDM4D is connected with advanced Fuhrman grade (p = 0.0118) and lower overall survival (p = 0.0020). Then, we revealed that KDM4D can prompt ccRCC development by interacting with genes related to vessel morphogenesis. Finally, we disclosed that KDM4D directly interacts with JAG1 promoter and advances tumor angiogenesis by upregulating VEGFR-3 and antagonizing notch signaling. The results of our study indicate that KDM4D would be a potential prognostic marker and therapeutic target for ccRCC patients.

Phase I Open-Label Study Evaluating the Safety, Pharmacokinetics, and Preliminary Efficacy of Dilpacimab in Patients with Advanced Solid Tumors

Dilpacimab (formerly ABT-165), a novel dual-variable domain immunoglobulin, targets both delta-like ligand 4 (DLL4) and VEGF pathways. Here, we present safety, pharmacokinetic (PK), pharmacodynamic (PD), and preliminary efficacy data from a phase I study (trial registration ID: NCT01946074) of dilpacimab in patients with advanced solid tumors. Eligible patients (≥18 years) received dilpacimab intravenously on days 1 and 15 in 28-day cycles at escalating dose levels (range, 1.25-7.5 mg/kg) until progressive disease or unacceptable toxicity. As of August 2018, 55 patients with solid tumors were enrolled in the dilpacimab monotherapy dose-escalation and dose-expansion cohorts. The most common treatment-related adverse events (TRAE) included hypertension (60.0%), headache (30.9%), and fatigue (21.8%). A TRAE of special interest was gastrointestinal perforation, occurring in 2 patients (3.6%; 1 with ovarian and 1 with prostate cancer) and resulting in 1 death. The PK of dilpacimab showed a half-life ranging from 4.9 to 9.5 days, and biomarker analysis demonstrated that the drug bound to both VEGF and DLL4 targets. The recommended phase II dose for dilpacimab monotherapy was established as 3.75 mg/kg, primarily on the basis of tolerability through multiple cycles. A partial response was achieved in 10.9% of patients (including 4 of 16 patients with ovarian cancer). The remaining patients had either stable disease (52.7%), progressive disease (23.6%), or were deemed unevaluable (12.7%). These results demonstrate that dilpacimab monotherapy has an acceptable safety profile, with clinical activity observed in patients with advanced solid tumors.

Suppression of human colon tumor by EERAC through regulating Notch/DLL4/Hes pathway inhibiting angiogenesis in vivo

Background: Ethanol extracted from radix of Actinidia chinensis (EERAC) has been proved to be effective to inhibit colorectal cancer (CRC). Notch signaling pathway and angiogenesis in tumors are closely related with the progression of CRC. However, if EERAC could influence CRC through Notch signaling pathway and angiogenesis remains unclear.

Methods: Flow cytometry, transwell, wound healing methods were used to measure cell apoptosis, invasion, migration, and proliferation. Protein and mRNA expression were detected using qRT-PCR and western blotting. Immunofluorescence staining was applied to detect the expression of target protein in the tissues.

Results: The invasion, migration, and proliferation of CRC cells were remarkably suppressed by ERRAC. Significant promotion of cell apoptosis and cell ration in S stage were observed after EERAC treatment. The Notch1/DLL4/Hes1 signaling pathway and angiogenesis were suppressed by EERAC. Overexpression of LIM domain-binding 2 (LDB2) remarkably weakened the influence of ERRAC on the viability of CRC cells.

Conclusions: EERAC might suppress CRC through targeting Notch/DLL4/Hes1 pathway and inhibiting angiogenesis in tumors. This study might provide novel thought for the prevention and therapy of CRC through targeting Notch/DLL4/Hes1.

Delta-like ligand 4 level in colorectal cancer is associated with tumor aggressiveness, body mass index and clinical outcome

BACKGROUND

The Notch signaling regulates numerous cell growth, differentiation, and death. However, the expression pattern of its ligand Delta-like 4 (DLL4) in tumors is still uncertain.

OBJECTIVE

In the present study, we examined DLL4 expression in colorectal cancer as well as assessed its role as a prognostic indicator in the present study.

METHODS

DLL4 expression was examined by immunohistochemistry in 265 surgically resected specimens of colorectal cancer and adjacent normal tissues. The relationship between DLL4 expression and clinicopathological characteristics was analyzed. The association of DLL4 expression with the patients' overall survival rate was assessed by Kaplan-Meier and Cox proportional-hazards regression.

RESULTS

Increased DLL4 level was detected in colorectal cancer compared with that of normal tissues. Elevated DLL4 level in colorectal cancer was associated with increased body mass index of patients. Moreover, increased DLL4 level was also found to be correlated with tumor invasion, metastases and unfavorable clinical outcom of patients.

CONCLUSIONS

DLL4 level is increased in colorectal cancer, especially in patients with increased body mass index, indicating potential involvement of obesity-related tumorigenesis and development. It might also serve as a novel molecular marker to predicate outcome of patients.

C118P, a novel microtubule inhibitor with anti-angiogenic and vascular disrupting activities, exerts anti-tumor effects against hepatocellular carcinoma

Hepatocellular carcinoma (HCC), a hypervascular solid tumor, is the most leading cause of cancer mortality worldwide. Microtubule binding agents targeting tumor vasculature have been investigated and employed clinically. C118P is a newly synthesized analog of CA4 with improved water solubility and extended half-life. The current studies investigated the pharmacological effects of C118P and its active metabolite C118. Here, we first confirmed by in vitro assays that C118 exerts microtubule depolymerization activity and by molecular docking revealed that it fits to the colchicine binding site of tubulin. In addition, we found that C118P and C118 altered microtubule dynamics and cytoskeleton in human umbilical vein endothelial cells. Accordingly, we observed that C118P and C118 inhibited angiogenesis and disrupted established vascular networks using tube formation assays and chick chorioallantoic membrane angiogenesis assays. In addition, our data showed that C118P and C118 exhibited board anti-proliferative effect on various cancer cells, including HCC cell lines, in MTT assays or Sulforhodamine B assays. Moreover, we found that C118P induced G2/M phase cell cycle arrest and apoptosis in HCC cell lines BEL7402 and SMMC7721 using flow cytometry analysis and immunoblotting assays. Finally, we confirmed that C118P suppressed HCC growth via targeting tumor vasculature and inducing apoptosis in the SMMC7721 xenograft mouse model. In conclusion, our studies revealed that C118P, as a potent microtubule destabilizing agent, exerts its multiple pharmacological effects against HCC by inducing cell cycle arrest and apoptosis, as well as targeting tumor vasculature. Thus, C118P might be a promising drug candidate for liver cancer treatment.

Clinical Efficacy and Safety of Angiogenesis Inhibitors: Sex Differences and Current Challenges

Vasoactive molecules, such as vascular endothelial growth factor (VEGF) and endothelins, share cytokine-like activities and regulate endothelial cell (EC) growth, migration and inflammation. Some endothelial mediators and their receptors are targets for currently approved angiogenesis inhibitors, drugs that are either monoclonal antibodies raised towards VEGF, or inhibitors of vascular receptor protein kinases and signaling pathways. Pharmacological interference with the protective functions of ECs results in a similar spectrum of adverse effects. Clinically, the most common side effects of VEGF signaling pathway inhibition include an increase in arterial pressure, left ventricular (LV) dysfunction ultimately causing heart failure, and thromboembolic events, including pulmonary embolism, stroke, and myocardial infarction. Sex steroids such as androgens, progestins, and estrogen and their receptors (ERα, ERβ, GPER; PR-A, PR-B; AR) have been identified as important modifiers of angiogenesis, and sex differences have been reported for anti-angiogenic drugs. This review article discusses the current challenges clinicians are facing with regard to angiogenesis inhibitor treatments, including the need to consider sex differences affecting clinical efficacy and safety. We also propose areas for future research taking into account the role of sex hormone receptors and sex chromosomes. Development of new sex-specific drugs with improved target and cell-type selectivity likely will open the way personalized medicine in men and women requiring antiangiogenic therapy and result in reduced adverse effects and improved therapeutic efficacy.

Inhibition of laser induced rats choroidal neovascularization by intravitreous injection of sEphB4-HSA

Background

Choroidal neovascularization (CNV) is a leading cause of central vision loss complicated with age-related macular degeneration. Although intravitreal anti-VEGF therapy is widely used in wet age-related macular degeneration, optimal treatment regimens for the disease are still under investigation. EphrinB2 and EphB4 regulate angiogenesis, and interruption of EphB4/ephrinB2 has been demonstrated to inhibit angiogenesis. In the current study, we studied the effects of soluble EphB4 (sEphB4) on laser induced CNV in a rat model by intravitreous injection and the underlying mechanism.

Methods

Male rats (Brown-Norway) were used in the study. CNV was induced by laser and the sEphB4 was injected intravitreous after laser at days 3 and 7. The CNV lesions were evaluated by three methods: fluorescein angiography (FA) in vivo, CNV volume by confocal analysis of choroidal flat-mounts and H&E staining. The expression of fibronectin (FN), VEGFR-2, phospho-VEGFR-2 (pVEGFR-2), the double labeling of EphB4 with FN was analyzed by immunofluorescence. The interaction of FN with EphB4 and the effects of intraocular injection of sEphB4 on the inhibition of pVEGFR-2 were determined by western blot.

Results

The FA leakage and CNV volume were significantly inhibited by the injection of the sEphB4. Further, histology analysis showed that CNV lesion was significantly smaller in the rats with sEphB4 injection than rats with placebo application. The expressions of pVEGFR-2 and FN in the CNV lesions were reduced compared with controls.

Conclusions

Our study suggests that the inhibition of CNV by sEphB4 may be through suppression of VEGFR-2 phosphorylation and the expression of FN. sEphB4 may be a new potential therapeutic strategy of CNV.

NOTCH signalling in ovarian cancer angiogenesis

The Notch signalling pathway is involved in the new vessel formation process by regulating tip and stalk cells, which are key cells in the sprout formation. This process is essential in both normal ovary and cancer angiogenesis and is regulated by Notch-VEGF crosstalk. Furthermore, Notch has been linked in ovary with stem cell maintenance and epithelial mesenchymal transition processes. Dysregulation of the Notch pathway is frequent in ovarian cancer (OC) and it has been associated with impaired survival and advanced stages or lymph node involvement. Notch also plays a role in chemoresistance to platinum. In this context, this pathway has emerged as an attractive target for precision medicine in OC. Two main targets of this pathway concentrate the clinical development of compounds blocking Notch: gamma secretase and Delta-like ligand 4. Most of the clinical trials including OC patients have been developed in phase I or phase Ib. Despite being in an early phase, both of these compounds, navicixizumab or demcizumab, two monoclonal antibodies targeting Dll4, showed promising efficacy data in platinum-resistant OC patients in recent studies. This review will focus on the mechanisms of the Notch pathway with special interest in angiogenesis regulation and the implication of Notch as a potential therapeutic target in OC.

Old Player-New Tricks: Non Angiogenic Effects of the VEGF/VEGFR Pathway in Cancer

Angiogenesis has long been considered to facilitate and sustain cancer growth, making the introduction of anti-angiogenic agents that disrupt the vascular endothelial growth factor/receptor (VEGF/VEGFR) pathway an important milestone at the beginning of the 21st century. Originally research on VEGF signaling focused on its survival and mitogenic effects towards endothelial cells, with moderate so far success of anti-angiogenic therapy. However, VEGF can have multiple effects on additional cell types including immune and tumor cells, by directly influencing and promoting tumor cell survival, proliferation and invasion and contributing to an immunosuppressive microenvironment. In this review, we summarize the effects of the VEGF/VEGFR pathway on non-endothelial cells and the resulting implications of anti-angiogenic agents that include direct inhibition of tumor cell growth and immunostimulatory functions. Finally, we present how previously unappreciated studies on VEGF biology, that have demonstrated immunomodulatory properties and tumor regression by disrupting the VEGF/VEGFR pathway, now provide the scientific basis for new combinational treatments of immunotherapy with anti-angiogenic agents.

Inhibitory effect of 5-FU loaded ultrasound microbubbles on tumor growth and angiogenesis

The anti-neovascularization treatment is one of the effective strategies for tumor molecular target therapy. At present, the target and effect of the anti-neovascularization treatment is limited, and it is urgent to establish a new vascular targeting strategy to effectively treat tumors. In this work, we used high intensity focused ultrasound (HIFU) combined with targeted microbubbles to establish a molecular targeted ultrasound response microbubble for neovascular cells. Furthermore, the effects of drug loaded microbubbles on neovascularization and tumor cells were studied. The tumor vascular targeted and ultrasound-responsive microbubbles of 5-FU@DLL4-MBs were prepared by the thin-film dispersion method. The size and zeta potential of 5-FU@DLL4-MBs was about 1248 nm and -9.1 mV. 5-FU@DLL4-MBs released 5-FU showed an ultrasound-responsive manner, and had better vascular-targeting ability. Furthermore, the 5-FU@DLL4-MBs showed the strongest cytotoxic effect on HUVECs or HepG-2 cells and can be effectively internalized into the HUVECs cells. Thus, 5-FU@DLL4-MBs combined with HIFU can be considered as a potential method for antitumor angiogenesis in the future.

Tumor-educated B cells promote renal cancer metastasis via inducing the IL-1β/HIF-2α/Notch1 signals

While B cells in the tumor microenvironment (TME) might play important roles in cancer progression, their impacts on the renal cell carcinoma (RCC) metastasis remained unclear, which drew our attention to further explore. We found that RCC tissues could recruit more B cells than the surrounding normal renal tissues from human clinical RCC samples. Wound healing assay, transwell assay and 3D invasion assays demonstrated that recruited B cells, also known as tumor-educated B cells (TEB), could significantly increase the RCC cell migration and invasion. In addition, in vivo data from xenograft RCC mouse model also confirmed that TEB could enhance RCC cell invasive and metastatic capability. Mechanism dissection revealed that TEB activated IL-1β/HIF-2α signals in RCC cells that could induce the downstream Notch1 signaling pathway. The above results demonstrated the key roles of TEB within renal cancer associated tumor microenvironment were metastasis-promotor and might help us to develop the potential therapies via targeting these newly identified IL-1β/HIF-2α/Notch1 signals in RCC progression.

Notch Signaling Pathway Is Involved in bFGF-Induced Corneal Lymphangiogenesis and Hemangiogenesis

BACKGROUND

Notch/Dll4 involvement in cornea neovascularization (CRNV) and lymphangiogenesis is unclear. This study aimed to explore the role of notch signaling in basic fibroblast growth factor- (bFGF-) induced corneal lymphangiogenesis and hemangiogenesis.

METHODS

Corneal stroma of C57BL/6 mice was implanted with bFGF- or phosphate-buffered saline- (PBS-) soaked pellets. Corneal lymphangiogenesis and neovascularization were evaluated by immunofluorescence. Vascular endothelial growth factor-A (VEGF-A), Delta-like ligand 4 (Dll4), and Notch1 mRNA and protein expression were examined on days 1, 3, 7, and 14 by real-time polymerase chain reaction and western blot. Corneal cells were treated with ranibizumab, dexamethasone, and γ-secretase inhibitor (GSI). Microspheres were used to evaluate corneal hemangiogenesis in vivo.

RESULTS

Corneal hemangiogenesis reached its peak on day 7 after bFGF implantation, and corneal lymphangiogenesis was significantly higher on day 7 and 14, compared with PBS. mRNA and protein expression of VEGF-A, Dll4, and Notch1 were higher in bFGF-induced animal models compared with controls. Corneal hemangiogenesis and lymphangiogenesis decreased after 7 days of ranibizumab or dexamethasone treatment. After adding GSI for 24 h in bFGF-induced cells, the expression of Notch1 and Dll4 were downregulated compared with that in the control group whereas the expression level of VEGF-A was upregulated. Fluorescent particle number was higher in the GSI group. Ranibizumab and dexamethasone decreased the fluorescence signal.

CONCLUSION

The notch signaling pathway plays a role in regulating VEGF expression, affecting corneal lymphangiogenesis and hemangiogenesis in mice. The molecular imaging probe technique can visualize the changes in the VEGF-A expression level of corneal limbus hemangiogenesis.

Evaluation of Local Injection of Bevacizumab against Triple-Negative Breast Cancer Xenograft Tumors

Background and objective:

Bevacizumab (BVZ) is a recombinant humanized antibody that inhibits the vascular endothelial growth factor A (VEGFA) and is used for the treatment of various types of cancer. BVZ is primarily given by the intravenous drip (I.V.), which often leads to low efficacy and various side effects. Therefore, the present study was to evaluate the effect of local delivery of BVZ against triple-negative breast cancer (TNBC) xenograft tumors.

Methods:

Mice 4T1 TNBC cells were engrafted in female BALB/c mice. After the tumors reached about 5 mm (diameter), animals were treated with BVZ through the local injection from four directions around the tumors. The tumor growth, survival and potential mechanisms of action were evaluated.

Results:

The growth and microvessel density of engrafted tumors were dramatically reduced with the tumor inhibition rate of 32.8 ± 3%. No obvious side effects were observed. The expression of VEGFA, VEGF receptor (VEGFR), matrix metalloproteinase (MMP)-2, MMP-9, Delta-like ligand 4 (DLL4) and Integrin-5 was significantly reduced in TNBC tumor tissues. In contrast, tissue inhibitor of matrix metalloproteinase (TIMP)-2 was significantly upregulated in xenograft tumors. Additionally, local delivery of BVZ led to the reduction of VEGFA and tumor necrosis factor (TNF)-alpha in the serum. Protein-protein interaction (PPI) analysis revealed that the proteins altered by the local delivery of BVZ were associated with angiogenesis and regulation of cell migration.

Conclusion:

This study provided evidence associated with local delivery of BVZ against TNBC tumors supporting the use of BVZ local injections to overcome some of the disadvantages associated with I.V. therapy with BVZ.

Arsenic Trioxide Suppresses Tumor Growth through Antiangiogenesis via Notch Signaling Blockade in Small-Cell Lung Cancer

Small-cell lung cancer (SCLC) is a highly malignant type of lung cancer with no effective second-line chemotherapy drugs. Arsenic trioxide (As2O3) was reported to exert antiangiogenesis activities against lung cancer and induce poor development of vessel structures, similar to the effect observed following the blockade of Notch signaling. However, there are no direct evidences on the inhibitory effects of As2O3 on tumor growth and angiogenesis via blockade of Notch signaling in SCLC. Here, we found that As2O3 significantly inhibited the tumor growth and angiogenesis in SCLC and reduced the microvessel density. As2O3 disturbed the morphological development of tumor vessels and downregulated the protein levels of delta-like canonical Notch ligand 4 (Dll4), Notch1, and Hes1 in vivo. DAPT, a Notch signaling inhibitor, exerted similar effects in SCLC. We found that both As2O3 treatment and Notch1 expression knockdown resulted in the interruption of tube formation by human umbilical vein endothelial cells (HUVECs) on Matrigel. As2O3 had no effects on Dll4 level in HUVECs but significantly inhibited the expression of Notch1 and its downstream gene Hes1 regardless of Dll4 overexpression or Notch1 knockdown. These findings suggest that the antitumor activity of As2O3 in SCLC was mediated via its antiangiogenic effect through the blockade of Notch signaling, probably owing to Notch1 targeting.

Tumor-derived exosomes: Implication in angiogenesis and antiangiogenesis cancer therapy

Tumor cells utilize different strategies to communicate with neighboring tissues for facilitating tumor progression and invasion, one of these strategies has been shown to be the release of exosomes. Exosomes are small nanovesicles secreted by all kind of cells in the body, especially cancer cells, and mediate cell to cell communications. Exosomes play an important role in cancer invasiveness by harboring various cargoes that could accelerate angiogenesis. Here first, we will present an overview of exosomes, their biology, and their function in the body. Then, we will focus on exosomes derived from tumor cells as tumor angiogenesis mediators with a particular emphasis on the underlying mechanisms in various cancer origins. Also, exosomes derived from stem cells and tumor-associated macrophages will be discussed in this regard. Finally, we will discuss the novel therapeutic strategies of exosomes as drug delivery vehicles against angiogenesis.

Evaluation of the correlation of vasculogenic mimicry, Notch4, DLL4, and KAI1/CD82 in the prediction of metastasis and prognosis in non-small cell lung cancer

Vasculogenic mimicry (VM) is a new blood supply style in tumors and has long been treated as a useful factor in malignant tumor metastasis and prognosis. Notch4 (a marker of Notch signaling pathway receptors), DLL4 (a marker of Notch signaling pathway ligands) and KAI1/CD82 (a suppressor gene of tumor metastasis) are all effective predictive factors for tumor metastasis. In this study, we analyzed correlations among VM, Notch4, DLL4, and KAI1/CD82 in non-small cell lung cancer (NSCLC), and their respective associations with patients' clinicopathological parameters and survival rate in NSCLC.Positive rates of VM, Notch4, DLL4, and KAI1/CD82 in 189 whole NSCLC specimens were detected by histochemical and immunohistochemical staining. Moreover, patients' clinicopathological information was also collected.Positive rates of VM, Notch4, and DLL4 were significantly higher, and levels of KAI1/CD82 were significantly lower in NSCLC than in normal lung tissues. Positive rates of VM, Notch4, and DLL4 were positively associated with tumor size, lymph node metastasis (LNM), distant metastasis (DM) and tumor-node-metastasis (TNM) stage, and inversely with patients, overall survival (OS) time and positive rate of DLL4 were positively associated with tumor grade. Levels of KAI1/CD82 were negatively associated with tumor size, LNM, DM, and TNM stage. The KAI1/CD82+ subgroup had significantly longer OS time than did the KAI1/CD82- subgroup. In multivariate analysis, high VM, Notch4, DLL4 levels, tumor size, LNM, DM, TNM stage, and low KAI1/CD82 levels were potential to be independent prognostic factors for overall survival time (OST) in NSCLC patients.VM and the expression of Notch4, DLL4, and KAI1/CD82 represent promising markers for tumor metastasis and prognosis, and maybe potential therapeutic targets for NSCLC.

Cryptotanshinone inhibits the growth and invasion of colon cancer by suppressing inflammation and tumor angiogenesis through modulating MMP/TIMP system, PI3K/Akt/mTOR signaling and HIF-1α nuclear translocation

The aim of this study was to evaluate the pharmacological effects of CPT on CT26 colon cancer cells in vivo and in vitro, and to reveal the potential mechanism. CPT suppressed the proliferation and growth of CT26 colon cancer in vitro and in vivo. CPT inhibited the invasion of CT26 cells in vitro, and decreased the protein expressions of matrix metalloproteinase-2 (MMP-2) and MMP-9 but increased those of tissue inhibitor of metallopeptidase-1 (TIMP-1) and TIMP-2 in vitro and in vivo. It also inhibited tumor cell-induced angiogenesis of endothelial cells in vitro and rat aortic ring angiogenesis ex vivo, and possibly by suppressing angiogenesis-associated factors. CPT suppressed the expressions of inflammatory factors in vivo and in vitro. Mechanism studies showed that CPT inhibited the PI3K/AKT/mTOR signaling pathway, as evidenced by decreased expressions of phospho-PI3K (p-PI3K), p-Akt and p-mTOR. Moreover, CPT significantly suppressed the nuclear expression but increased the cytosolic expression of hypoxia inducible factor-1α (HIF-1α). Collectively, CPT inhibited the growth, invasion, inflammation and angiogenesis in CT26 colon cancer, and at least partly, by regulating the PI3K/Akt/mTOR signaling and the nuclear translocation of HIF-1α.

Crosstalk between Notch, HIF-1α and GPER in Breast Cancer EMT

The Notch signaling pathway acts in both physiological and pathological conditions, including embryonic development and tumorigenesis. In cancer progression, diverse mechanisms are involved in Notch-mediated biological responses, including angiogenesis and epithelial-mesenchymal-transition (EMT). During EMT, the activation of cellular programs facilitated by transcriptional repressors results in epithelial cells losing their differentiated features, like cell–cell adhesion and apical–basal polarity, whereas they gain motility. As it concerns cancer epithelial cells, EMT may be consequent to the evolution of genetic/epigenetic instability, or triggered by factors that can act within the tumor microenvironment. Following a description of the Notch signaling pathway and its major regulatory nodes, we focus on studies that have given insights into the functional interaction between Notch signaling and either hypoxia or estrogen in breast cancer cells, with a particular focus on EMT. Furthermore, we describe the role of hypoxia signaling in breast cancer cells and discuss recent evidence regarding a functional interaction between HIF-1α and GPER in both breast cancer cells and cancer-associated fibroblasts (CAFs). On the basis of these studies, we propose that a functional network between HIF-1α, GPER and Notch may integrate tumor microenvironmental cues to induce robust EMT in cancer cells. Further investigations are required in order to better understand how hypoxia and estrogen signaling may converge on Notch-mediated EMT within the context of the stroma and tumor cells interaction. However, the data discussed here may anticipate the potential benefits of further pharmacological strategies targeting breast cancer progression.

Tumor angiogenesis and anti-angiogenic gene therapy for cancer

When Folkman first suggested a theory about the association between angiogenesis and tumor growth in 1971, the hypothesis of targeting angiogenesis to treat cancer was formed. Since then, various studies conducted across the world have additionally confirmed the theory of Folkman, and numerous efforts have been made to explore the possibilities of curing cancer by targeting angiogenesis. Among them, anti-angiogenic gene therapy has received attention due to its apparent advantages. Although specific problems remain prior to cancer being fully curable using anti-angiogenic gene therapy, several methods have been explored, and progress has been made in pre-clinical and clinical settings over previous decades. The present review aimed to provide up-to-date information concerning tumor angiogenesis and gene delivery systems in anti-angiogenic gene therapy, with a focus on recent developments in the study and application of the most commonly studied and newly identified anti-angiogenic candidates for anti-angiogenesis gene therapy, including interleukin-12, angiostatin, endostatin, tumstatin, anti-angiogenic metargidin peptide and endoglin silencing.

ATAD2 silencing decreases VEGFA secretion through targeting has-miR-520a to inhibit angiogenesis in colorectal cancer

ATPase family AAA domain-containing protein 2 (ATAD2) is involved in various types of cancers, including colorectal cancer. This study aimed to determine the role of ATAD2 in angiogenesis in colorectal cancer. Here, we downregulated ATAD2 expression in HCT116 and SW480 cells, and collected the conditioned medium (CM) from control and ATAD2-silenced cells. The effect of CM on human umbilical vein endothelial cells (HUVEC) was evaluated by using CCK-8, wound healing, tube formation, Western blot, and dual-luciferase reporter assays. Our results showed that the proliferation, migration, and tube formation of HUVEC were reduced in presence of ATAD2-silenced CM, and the levels of phosphorylated vascular endothelial growth factor receptor 2 (P-VEGFR2), CD31, and CD34 were downregulated. Mechanism studies showed that ATAD2 silencing regulated the expression of vascular endothelial growth factor A (VEGFA) and miR-520a. Moreover, we found that miR-520a could bind to ATAD2, and its inhibitor partly reversed the alterations in HUVEC induced by CM from ATAD2-silenced cells. In addition, we demonstrated that miR-520a directly bound to 3'-UTR of VEGFA and inhibited its expression. Collectively, our results indicate that ATAD2 inhibition suppresses VEGFA secretion by increasing miR-520a levels. Our study suggests ATAD2 as a potential therapeutic target for angiogenesis in colorectal cancer.

NOTCH4 regulates colorectal cancer proliferation, invasiveness, and determines clinical outcome of patients

Notch signal has complex roles in human malignancies, which might be attributed to the diversity of Notch receptors. Here, we set out to identify the association of NOTCH4 with colorectal cancer (CRC). In the hospital-based study cohort, we investigated NOTCH4 mRNA levels in primary CRC, as well as its association with clinicopathologic characteristics. Besides, NOTCH4 cDNA and siRNA was transfected into colorectal cancer cell line to elucidate its impact on tumor cell proliferation and migration. Results revealed a statistically significant lower expression of NOTCH4 mRNA in tumor specimens compared with that in control. NOTCH4 level in CRC was found to be related to tumor differentiation, invasion, and node metastasis. Moreover, it was demonstrated that NOTCH4 mRNA level could be an independent prognostic factor for both disease-free and overall survival of CRC patients. Overexpression of NOTCH4 in CRC cell lines suppressed tumor cell proliferation, migration, and invasion, while induced apoptosis. In the opposite, the malignant behavior of CRC cells was enhanced by NOTCH4 knockdown. These results demonstrated for the first time that NOTCH4 expression was decreased in CRC, which could determine tumor proliferation, relapse, and prognosis.

MicroRNA-296: a promising target in the pathogenesis of atherosclerosis?

Atherosclerosis has been recognized as an inflammatory disease involving the vascular wall. MicroRNAs are a group of small noncoding RNAs to regulate gene expression at the transcriptional level through mRNA degradation or translation repression. Recent studies suggest that miR-296 may play crucial roles in the regulation of angiogenesis, inflammatory response, cholesterol metabolism, hypertension, cellular proliferation and apoptosis. In this review, we primarily discussed the molecular targets of miR-296 involved in the development of atherosclerosis, which may provide a basis for future investigation and a better understanding of the biological functions of miR-296 in atherosclerosis.

Angiogenesis and Anti-Angiogenic Therapy in Gastric Cancer

Gastric cancer is one of the most frequent malignancies worldwide. Despite improvements in diagnosis and therapy, the overall prognosis remains poor. In the last decade, several anti-angiogenic drugs for cancer treatment have been approved and lately also introduced to gastric cancer treatment. While the initial trials focused only on unresectable or metastatic cancer, anti-angiogenic treatment is now also investigated in the perioperative and neoadjuvant setting. In this review, an overview of the role of angiogenesis and angiogenic factors in gastric cancer as well as anti-angiogenic treatment of gastric cancer is provided. Findings from in vitro and animal studies are summarized and put in a context with translational data on angiogenesis in gastric cancer. The most important angiogenic factors and their effect in gastric cancer are highlighted and clinical trials including anti-angiogenic drugs are discussed. Finally, an outlook of biomarkers for predicting response to anti-angiogenic treatment is presented, the ongoing trials on this topic are discussed and current challenges of anti-angiogenic therapy are outlined.

Roles of PFKFB3 in cancer

The understanding of 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 3 (PFK-2/FBPase 3, PFKFB3) has advanced considerably since its initial identification in human macrophages in the mid-1990s. As a vital regulator of glycolysis, accumulating studies have suggested that PFKFB3 is associated with many aspects of cancer, including carcinogenesis, cancer cell proliferation, vessel aggressiveness, drug resistance and tumor microenvironment. In this review, we summarize current knowledge of PFKFB3 regulation by several signal pathways and its function in cancer development in different cell types in cancer tissues. Ubiquitous PFKFB3 has emerged as a potential target for anti-neoplastic therapy.

The mechanism and potential targets of class II HDACs in angiogenesis

Angiogenesis refers to the new blood vessels deriving from the existing blood vessels, and it is a complex regulatory process. Angiogenesis is associated with the normal development of the body and tumor growth and migration. The imbalance of histone deacetylase, as an epigenetic modification, could induce the production of diseases, such as cancer, metabolic diseases, etc., and it also plays an important role in angiogenesis. Many researches indicate that class II HDACs nuclear shuttle and its phosphorylation are necessary for the diseases and the protection of the collective itself. This paper will make a review for the relationship between II HDACs and angiogenesis under physiological and pathologic categories, looking forward to the disease treatment in the future.

Therapeutic strategies against cancer stem cells in human colorectal cancer

Colorectal cancer (CRC) is the third most frequent malignancy and represents the fourth most common cause of cancer-associated mortalities in the world. Despite many advances in the treatment of CRC, the 5-year survival rate of patients with CRC remains unsatisfactory due to tumor recurrence and metastases. Recently, cancer stem cells (CSCs), have been suggested to be responsible for the initiation and relapse of the disease, and have been identified in CRC. Due to their basic biological features, which include self-renewal and pluripotency, CSCs may be novel therapeutic targets for CRC and other cancer types. Conventional therapeutics only act on proliferating and mature cancer cells, while quiescent CSCs survive and often become resistant to chemotherapy. In this review, markers of CRC-CSCs are evaluated and the recently introduced experimental therapies that specifically target these cells by inducing CSC proliferation, differentiation and sensitization to apoptotic signals via molecules including Dickkopf-1, bone morphogenetic protein 4, Kindlin-1, tankyrases, and p21-activated kinase 1, are discussed. In addition, novel strategies aimed at inhibiting some crucial processes engaged in cancer progression regulated by the Wnt, transforming growth factor β and Notch signaling pathways (pyrvinium pamoate, silibinin, PRI-724, P17, and P144 peptides) are also evaluated. Although the metabolic alterations in cancer were first described decades ago, it is only recently that the concept of targeting key regulatory molecules of cell metabolism, such as sirtuin 1 (miR-34a) and AMPK (metformin), has emerged. In conclusion, the discovery of CSCs has resulted in the definition of novel therapeutic targets and the development of novel experimental therapies for CRC. However, further investigations are required in order to apply these novel drugs in human CRC.

[The cellular and molecular mechanisms of angiogenesis regulation in the brain]

This review presents the data on cellular and molecular mechanisms of angiogenesis regulation linked to the vascular epithelium. According to current conceptions, activated endothelial cells and their predecessors (progenitor cells) are involved in the regulation of angiogenesis. These cells synthesize angiogenic molecules differing by the chemical structure and mechanism of biological effect and allowing a direct or indirect control over each stage of angiogenesis. Both the excess and insufficient angiogenesis can lead to fast and irreversible changes in nervous tissue under certain conditions. For this reason, the balance in the system of molecular stimulators and inhibitors of angiogenesis is especially important for brain function. Without adequate reperfusion of an affected brain area the post-stroke neuroreparation, which can be provided with timely stimulation of angiogenesis, is unattainable and the intensification of this process in tumors, on the contrary, has adverse consequences. Growth of a tumor and its metastatic spread are substantially associated with an increase in the level of tumor tissue vascularization, and blocking angiogenesis is often the only productive way to limit the growth of a tumor. However our knowledge of mechanisms of angiogenesis regulation in the brain on the cellular and molecular level in physiological and pathological conditions is still insufficient, and, therefore, the influence of angiogenic factors on tissue targets do not always cause the expected effects.

Expression of Jagged1/Notch3 Signaling Pathway and their Relationship with the Tumor Angiogenesis in TNBC

BACKGROUND AND AIMS

Jagged1/Notch3 signaling pathway plays a key role in angiogenesis of breast cancer, but little is known in TNBC. This study was designed to investigate the expression of Jagged1/Notch3 mRNA and protein in TNBC, analyze their correlations with clinicopathological characteristics and prognosis. Moreover, the interrelationship among Jagged1/Notch3 and VEGF was initially evaluated.

METHODS

Jagged1/Notch3 mRNA and protein expression levels were determined by Q-RT-PCR and Western blotting. Additionally, Immunohistochemistry for Jagged1/Notch3 was detected by Ventana platform, VEGF and CD34 was performed using the EnVision/HRP technique.

RESULTS

mRNA transcriptionof Jagged1/Notch3 was in accord with protein expression. TNBC patients with positive Jagged1 expression had poorer DFS (p = 0.008) and OS (p = 0.004). Jagged1 expression was independent predictors of OS (p = 0.038). The expression of VEGF was positively correlative to MVD (p = 0.018), MVD was significantly associated with Jagged1 (p <0.0001) and Notch3 (p <0.0001). The expression of Jagged1/Notch3 has no correlation with VEGF, only in positive VEGF expression of TNBC patients Jagged1/Notch3 had influence on DFS and OS (p <0.05).

CONCLUSION

Jagged1/Notch3 was -expressed at both the mRNA and protein levels, Jagged1 served as an independent predictor of poor prognosis. We speculate that there is a cross-talk between Jagged1/Notch3 and VEGF in TNBC angiogenesis. Jagged1/Notch3 is expected to be an important signaling pathway for TNBC progression and a potential target for TNBC neovascularization therapy.

Notch signaling in regulating angiogenesis in a 3D biomimetic environment

Angiogenesis is a complex cellular process involving highly orchestrated invasion and organization of endothelial cells (ECs) in a three-dimensional (3D) environment. Recent evidence indicates that Notch signaling is critically involved in regulating specialized functions and distinct fates of ECs in newly formed vasculatures during angiogenesis. Here, we demonstrated, for the first time, the application of a microengineered biomimetic system to quantitatively investigate the role of Notch signaling in regulating early angiogenic sprouting and vasculature formation of ECs in a 3D extracellular matrix. Morphological features of angiogenesis including invasion distance, invasion area, and tip cell number were quantified and compared under pharmacological perturbations of Notch signaling. In addition, influences of Notch signaling on EC proliferation in angiogenic vasculatures and directional invasion of tip cells were also investigated. Moreover, leveraging a novel nanobiosensor system, mRNA expression of Dll4, a Notch ligand, was monitored in invading tip cells using live cell imaging during the dynamic angiogenic process. Our data showed that inhibition of Notch signaling resulted in hyper-sprouting endothelial structures, while activation of Notch signaling led to opposite effects. Our results also supported the role of Notch signaling in regulating EC proliferation and dynamic invasion of tip cells during angiogenesis.

Screening study on the anti-angiogenic effects of Traditional Chinese Medicine - Part I: Heat-clearing and detoxicating TCM

ETHNOPHARMACOLOGICAL RELEVANCE

Few studies have explored the anti-angiogenic effects of TCM - even more so, as it applies to cancer treatment research. Heat-clearing and detoxicating TCM is the most frequently used category in the treatment of cancerous tumors, but lacks sufficient validation studies.

AIM OF THE STUDY

The present research (in our series of studies) aims to explore the anti-angiogenic effects of TCM; so we begin with heat-clearing and detoxicating TCM.

MATERIALS AND METHODS

Six typical heat-clearing and detoxicating TCM (Philippine Violet Herb, Wild Chrysanthemum, Heartleaf Houttuynia Herb, Chinese Lobelia Herb, Spreading Hedyotis Herb and Uniflower Swisscentaury Root) were decocted, concentrated, sieved and desiccated to attain the water extract. This study utilized the vascular organism research model for Fli1a-EGFP zebrafish, which were raised and maintained under standard conditions. 22h post-fertilization (hpf) embryos were distributed into 12-well plates for a treatment period of 26h. The TCM water extracts which were diluted in 0.1% dimethyl sulfoxide (DMSO), were added to each well at a concentration of 200μg/ml. The positive control was 5μg/ml PTK787 (vatalanib) and the vehicle control was 0.1% DMSO. At 48hpf larvae were tricaine anesthetized and imaged. To demonstrate if TCM shows angiogenesis defects, ten larvae were randomly chosen to conduct a quantitative assay. Quantitative real-time PCR was conducted to dissect the mechanisms involved by analyzing the contributions of signaling pathways and molecules concerning angiogenesis, with a total of ten genes examined.

RESULTS

All 30 larvae treated with Wild Chrysanthemum, Uniflower Swisscentaury Root and PTK787 showed angiogenesis defects. Embryos treated with Wild Chrysanthemum and Uniflower Swisscentaury Root showed a lower number of complete intersegmental vessels (ISVs) and there was statistically significant differences between TCM and the vehicle control. Wild Chrysanthemum and Uniflower Swisscentaury Root have a higher inhibition rate and the statistical difference between TCM and the vehicle control was significant. Compared with vehicle controls, Wild Chrysanthemum could significantly modulate the relative mRNA expression of all ten genes. Whereas, Uniflower Swisscentaury Root could significantly regulate the relative mRNA expression of seven genes, it did not show a significant impact on the remaining three genes.

CONCLUSIONS

The present research demonstrates that Wild Chrysanthemum and Uniflower Swisscentaury Root have anti-angiogenic effects in zebrafish and that they could regulate both proangiogenic mechanisms and negative angiogenesis regulators. Their anti-angiogenic effects result from effects on negative regulators overriding their effects on proangiogenic mechanisms. The results provide new insights into their clinical application and therapeutic potential for the management of angiogenesis-dependent diseases such as cancer.

DLL4 overexpression increases gastric cancer stem/progenitor cell self-renewal ability and correlates with poor clinical outcome via Notch-1 signaling pathway activation

Gastric cancer is one of the most common malignant diseases, and poses a serious threat to the quality of human life. Gastric cancer stem/progenitor cells (GCSPCs) have critical effects on tumor formation, affecting specific features of self‐renewal and differentiation and playing a critical role in metastasis. The Notch‐1 pathway is crucially important to GCSPCs and is regulated by DLL4. In this study, DLL4 and Nestin levels were measured in 383 gastric cancer tissue samples by immunohistochemistry, and the clinico‐pathological features of patients assessed. After DLL4 silencing in selected gastric cancer cell lines, the expression of GCSPC markers and colony formation ability were analyzed and the self‐renewal and differentiation capacities of the cells were evaluated. The relationship between DLL4 levels and Notch‐1 signaling pathway effector amounts was assessed via Western blotting and immunofluorescence. Finally, the tumor formation ability of the gastric cancer cells was evaluated with different levels of DLL4 and multiple cell densities in vivo. Our results indicate that DLL4 expression is associated with TNM stage and cancer metastasis, with high amounts of DLL4 leading to poor outcome. DLL4 silencing inhibited the self‐renewal ability of GCSPCs and increased their multidifferentiation capacity, resulting in reduced GCSPC ratios. DLL4 knockdown also blocked the Notch‐1 pathway, weakening invasion ability and resistance to 5‐FU chemotherapy. In vivo, DLL4 silencing inhibited the tumor formation ability of GCSPCs. In conclusion, DLL4 affects GCSPC stemness, altering their pathological behavior. DLL4 silencing inhibits GCSPC metastatic potential both in vitro and in vivo by impeding Notch‐1 signaling pathway activation, indicating that DLL4 may be a new potential therapeutic target.

Notch: A multi-functional integrating system of microenvironmental signals

The Notch signaling cascade is an evolutionarily ancient system that allows cells to interact with their microenvironmental neighbors through direct cell-cell interactions, thereby directing a variety of developmental processes. Recent research is discovering that Notch signaling is also responsive to a broad variety of stimuli beyond cell-cell interactions, including: ECM composition, crosstalk with other signaling systems, shear stress, hypoxia, and hyperglycemia. Given this emerging understanding of Notch responsiveness to microenvironmental conditions, it appears that the classical view of Notch as a mechanism enabling cell-cell interactions, is only a part of a broader function to integrate microenvironmental cues. In this review, we summarize and discuss published data supporting the idea that the full function of Notch signaling is to serve as an integrator of microenvironmental signals thus allowing cells to sense and respond to a multitude of conditions around them.

Analysis of Body-wide Unfractionated Tissue Data to Identify a Core Human Endothelial Transcriptome

Endothelial cells line blood vessels and regulate hemostasis, inflammation, and blood pressure. Proteins critical for these specialized functions tend to be predominantly expressed in endothelial cells across vascular beds. Here, we present a systems approach to identify a panel of human endothelial-enriched genes using global, body-wide transcriptomics data from 124 tissue samples from 32 organs. We identified known and unknown endothelial-enriched gene transcripts and used antibody-based profiling to confirm expression across vascular beds. The majority of identified transcripts could be detected in cultured endothelial cells from various vascular beds, and we observed maintenance of relative expression in early passage cells. In summary, we describe a widely applicable method to determine cell-type-specific transcriptome profiles in a whole-organism context, based on differential abundance across tissues. We identify potential vascular drug targets or endothelial biomarkers and highlight candidates for functional studies to increase understanding of the endothelium in health and disease.

Therapeutic application of anti-angiogenic nanomaterials in cancers

Angiogenesis, the formation of new blood vessels from pre-existing vasculature, plays a vital role in physiological and pathological processes (embryonic development, wound healing, tumor growth and metastasis). The overall balance of angiogenesis inside the human body is maintained by pro- and anti-angiogenic signals. The processes by which drugs inhibit angiogenesis as well as tumor growth are called the anti-angiogenesis technique, a most promising cancer treatment strategy. Over the last couple of decades, scientists have been developing angiogenesis inhibitors for the treatment of cancers. However, conventional anti-angiogenic therapy has several limitations including drug resistance that can create problems for a successful therapeutic strategy. Therefore, a new comprehensive treatment strategy using antiangiogenic agents for the treatment of cancer is urgently needed. Recently researchers have been developing and designing several nanoparticles that show anti-angiogenic properties. These nanomedicines could be useful as an alternative strategy for the treatment of various cancers using anti-angiogenic therapy. In this review article, we critically focus on the potential application of anti-angiogenic nanomaterial and nanoparticle based drug/siRNA/peptide delivery systems in cancer therapeutics. We also discuss the basic and clinical perspectives of anti-angiogenesis therapy, highlighting its importance in tumor angiogenesis, current status and future prospects and challenges.