VEGF/VEGFR signalling as a target for inhibiting angiogenesis

Variations of VEGFR2 Chemical Space: Stimulator and Inhibitory Peptides

The kinase pathway plays a crucial role in blood vessel function. Particular attention is paid to VEGFR type 2 angiogenesis and vascular morphogenesis as the tyrosine kinase pathway is preferentially activated. In silico studies were performed on several peptides that affect VEGFR2 in both stimulating and inhibitory ways. This investigation aims to examine the molecular properties of VEGFR2, a molecule primarily involved in the processes of vasculogenesis and angiogenesis. These relationships were defined by the interactions between Vascular Endothelial Growth Factor receptor 2 (VEGFR2) and the structural features of the systems. The chemical space of the inhibitory peptides and stimulators was described using topological and energetic properties. Furthermore, chimeric models of stimulating and inhibitory proteins (for VEGFR2) were computed using the protein system structures. The interaction between the chimeric proteins and VEGFR was computed. The chemical space was further characterized using complex manifolds and high-dimensional data visualization. The results show that a slightly similar chemical area is shared by VEGFR2 and stimulating and inhibitory proteins. On the other hand, the stimulator peptides and the inhibitors have distinct chemical spaces.

Design, synthesis, and biological evaluation of naphthalene imidazo[1,2-b]pyridazine hybrid derivatives as VEGFR selective inhibitors

The vascular endothelial growth factor receptor (VEGFR) is a receptor tyrosine kinase that is regarded as an emerging target for abnormal angiogenesis diseases. In this study, novel naphthalene imidazo[1,2-b]pyridazine hybrids as VEGFR selective inhibitors were designed and synthesized using a scaffold hopping strategy based on ponatinib, a multitarget kinase inhibitor. Among the evaluated compounds, derivative 9k (WS-011) demonstrated the most potent inhibitory potency against VEGFR-2 (IC50 = 8.4 nM) and displayed superior VEGFR selectivity over a panel of 70 kinases compared with ponatinib. Furthermore, 9k possessed good cytotoxic effects on various cancer cell lines, especially the colon cancer HT-29 cells, with an acceptable oral bioavailability. Moreover, 9k significantly inhibited the migration and invasion of human umbilical vein endothelial cells (HUVEC) cells and induced apoptosis through the upregulation of apoptotic proteins in HT-29 cells. 9k also effectively suppressed the activation of VEGFR-2 signaling pathways, which in turn inhibited the growth of HT-29 cells and the tube formation of HUVECs in vitro. All of the findings revealed that 9k could be considered a promising antiangiogenesis lead that merits further investigation.

Exploitation of enhanced prime editing for blocking aberrant angiogenesis

INTRODUCTION

Aberrant angiogenesis plays an important part in the development of a variety of human diseases including proliferative diabetic retinopathy, with which there are still numerous patients remaining a therapeutically challenging condition. Prime editing (PE) is a versatile gene editing approach, which offers a novel opportunity to genetically correct challenging disorders.

OBJECTIVES

The goal of this study was to create a dominant-negative (DN) vascular endothelial growth factor receptor (VEGFR) 2 by editing genomic DNA with an advanced PE system to block aberrant retinal angiogenesis in a mouse model of oxygen-induced retinopathy.

METHODS

An advanced PE system (referred to as PE6x) was established within two lentiviral vectors, with one carrying an enhanced PE guide RNA and a canonical Cas9 nickase fused with an optimized reversal transcriptase, and the other conveying a nicking guide RNA and a DN-MLH1 to improve PE efficiency. Dual non-integrating lentiviruses (NILVs) produced with the two lentiviral PE6x vectors were then employed to create a mutation of VEGFR2 T17967A by editing the Mus musculus VEGFR2 locus in vitro and in vivo, leading to generation of a premature stop codon (TAG, K796stop) to produce DN-VEGFR2, to interfere with the wild type VEGFR2 which is essential for angiogenesis.

RESULTS

NILVs targeting VEGFR2 delivered into cultured murine vascular endothelial cells led to 51.06 % VEGFR2 T17967A in the genome analyzed by next generation sequencing and the production of DN-VEGFR2, which was found to hamper VEGF-induced VEGFR2 phosphorylation, as demonstrated by Western blot analysis. Intravitreally injection of the dual NILVs into postnatal day 12 mice in a model of oxygen-induced retinopathy, led to production of retinal DN-VEGFR2 in postnatal day 17 mice which blocked retinal VEGFR2 expression and activation as well as abnormal retinal angiogenesis without interfering with retinal structure and function, as assessed by electroretinography, optical coherence tomography, fundus fluorescein angiography and histology.

CONCLUSION

DN-VEGFR2 resulted from editing genomic VEGFR2 using the PE6x system can be harnessed to treat intraocular pathological angiogenesis.

Pyrrolo[2,3-D]Pyrimidines as EGFR and VEGFR Kinase Inhibitors: A Comprehensive SAR Review

Tyrosine kinases are implicated in a wide array of cellular physiological processes, including cell signaling. The discovery of the BCR-ABL tyrosine kinase inhibitor imatinib and its FDA approval in 2001 paved the way for the development of small molecule chemical entities of diverse structural backgrounds as tyrosine kinase inhibitors for the treatment of various ailments. Two of the most prominent tyrosine kinases as drug targets are the epidermal growth factor receptor (EGFR) and the vascular endothelial growth factor receptor (VEGFR), as evidenced by the clinical success of their many inhibitors in the drug market. Among several other physiological roles, EGFR regulates epithelial tissue development and homeostasis, while VEGFR regulates tumor-induced angiogenesis. The pyrrolo[2,3-d]pyrimidine nucleus represents a deaza-isostere of adenine, the nitrogenous base of ATP. The recent introduction of many pyrrolo[2,3-d]pyrimidines to the drug market as tyrosine kinase inhibitors makes them a hot topic in the medicinal chemistry research area at the present time. This review article comprehensively sheds light on the structure-activity relationship (SAR) of pyrrolo[2,3-d]pyrimidines as EGFR and VEGFR tyrosine kinase inhibitors, aiming to provide help medicinal chemists in the design of future pyrrolopyrimidine kinase inhibitors.

Decoding the molecular mechanism of stypoldione against breast cancer through network pharmacology and experimental validation

Breast cancer is the primary factor contributing to female mortality worldwide. The incidence has overtaken lung cancer. It is the most difficult illness due to its heterogeneity and is made up of several subtypes, including Luminal A and B, basal-like, Her-2 overexpressed and TNBC. Amongst different breast carcinoma subtypes, TNBC is the most deadly breast cancer subtype. The hostile nature of TNBC is mainly attributed to its lack of three hormonal receptors and hence lack of targeted therapy. Furthermore, the current diagnostic options like radiotherapy, surgery and chemotherapy render unsuccessful due to recurrence, treatment side effects and drug resistance. The majority of anticancer drugs come from natural sources or is developed from them, making nature a significant source of many medicines. Marine-based constituents such as nucleotides, proteins, peptides, and amides are receiving a lot of interest in the field of cancer treatment due to their bioactive properties. The role of stypoldione in this study as a prospective treatment for breast carcinoma was examined, and we sought to comprehend the molecular means/pathways this chemical employs in breast carcinoma. The most promising possibility for an anti-cancer treatment is stypoldione, a marine chemical produced from the brown alga Stypopodium zonale. We investigated stypoldione's mode of action in breast cancer using the network pharmacology method, and we confirmed our research by using a number of computational tools, including UALCAN, cBioportal, TIMER, docking, and simulation. The findings revealed 92 common targets between the chemical and breast cancer target network. Additionally, we found that stypoldione targets a number of unregulated genes in breast cancer, including: ESR1, HSP90AA1, CXCL8, PTGS2, APP, MDM2, JAK2, KDR, LCK, GRM5, MAPK14, KIT, and several signaling pathways such as FOXO signaling pathway, VEGF pathway, calcium signaling pathway, MAPK/ERK pathway and Neuroactive ligand-receptor interaction. The examined medication demonstrated a strong affinity for the major targets, according to a docking analysis. The best hit compound produced a stable protein-ligand pair, as predicted by molecular dynamics simulations. Our results are supported by the fact that when in-vitro assays were done on melanoma using stypoldione compound it was found that its mechanisms of action involved the PI3K/mTOR/Akt and NF-kB pathways. This study was set out to inspect the possible value of stypoldione as a breast cancer cure and to get a deeper understanding of the molecular mechanisms by which this drug acts on breast cancer.

Effects of 1-year tofacitinib therapy on angiogenic biomarkers in rheumatoid arthritis

OBJECTIVES

Cardiovascular (CV) morbidity and mortality, and perpetuated synovial angiogenesis have been associated with RA. In our study we evaluated angiogenic factors in relation to vascular inflammation and function, and clinical markers in RA patients undergoing 1-year tofacitinib therapy.

METHODS

Thirty RA patients treated with either 5 mg or 10 mg twice daily tofacitinib were included in a 12-month follow-up study. Eventually, 26 patients completed the study and were included in data analysis. Levels of various angiogenic cytokines (TNF-α, IL-6), growth factors [VEGF, basic fibroblast (bFGF), epidermal (EGF), placental (PlGF)], cathepsin K (CathK), CXC chemokine ligand 8 (CXCL8), galectin-3 (Gal-3) and N-terminal prohormone brain natriuretic peptide (NT-proBNP) were determined at baseline, and at 6 and 12 months after initiating tofacitinib treatment. In order to assess flow-mediated vasodilation, common carotid intima-media thickness (ccIMT) and carotid-femoral pulse-wave velocity, ultrasonography was performed. Synovial and aortic inflammation was also assessed by 18F-fluorodeoxyglucose-PET/CT.

RESULTS

One-year tofacitinib therapy significantly decreased IL-6, VEGF, bFGF, EGF, PlGF and CathK, while it increased Gal-3 production (P < 0.05). bFGF, PlGF and NT-proBNP levels were higher, while platelet-endothelial cell adhesion molecule 1 (PECAM-1) levels were lower in RF-seropositive patients (P < 0.05). TNF-α, bFGF and PlGF correlated with post-treatment synovial inflammation, while aortic inflammation was rather dependent on IL-6 and PECAM-1 as determined by PET/CT (P < 0.05). In the correlation analyses, NT-proBNP, CXCL8 and Cath variables correlated with ccIMT (P < 0.05).

CONCLUSIONS

Decreasing production of bFGF, PlGF or IL-6 by 1-year tofacitinib therapy potentially inhibits synovial and aortic inflammation. Although NT-proBNP, CXCL8 and CathK were associated with ccIMT, their role in RA-associated atherosclerosis needs to be further evaluated.

A machine learning-based KNIME workflow to predict VEGFR-2 inhibitors

Vascular endothelial growth factors (VEGFs) are specific cytokines involved in angiogenesis and do so via binding to vascular endothelial growth factor receptors (VEGFRs), a type of receptor tyrosine kinase. VEGFs are reported to facilitate angiogenesis in physiological (embryogenesis) and pathological (tumor) conditions. The overexpression of VEGFs and consequently VEGFRs is reported in tumorigenic conditions. Several VEGFR inhibitors currently used as anticancer drugs to prevent angiogenesis are sunitinib, sorafenib, etc. To identify new potential candidates as VEGFR inhibitors, a classification study using a large and diverse dataset of VEGFR inhibitors from the BindingDB database has been conducted. The KNIME platform was used to calculate molecular and fingerprint-based descriptors and several classification algorithms viz. linear regression (LR), k-nearest neighbor (kNN), decision tree (DT), random forest (RF), and gradient boosted tree (GBT) were employed to build the classification model. The model performance was evaluated by accuracy, precision, recall, and F1 score of the test set. The best LR, kNN, DT, RF, and GBT classifiers had the F1 score of 0.81, 0.87, 0.82, 0.87, and 0.87, respectively. The assorted 5120 VEGFR inhibitors were clustered into 10 subsets, and the structural features of each subset were assessed along with the identification of significant fragments in active and inactive compounds. The automated classifier model developed using the KNIME platform could serve as an important platform for screening and designing molecules as VEGFR inhibitors.

Scandium-44 Radiolabeled Peptide and Peptidomimetic Conjugates Targeting Neuropilin-1 Co-Receptor as Potential Tools for Cancer Diagnosis and Anti-Angiogenic Therapy

Pathological angiogenesis, resulting from an imbalance between anti- and pro-angiogenic factors, plays a pivotal role in tumor growth, development and metastasis. The inhibition of the angiogenesis process by the VEGF/VEGFR-2/NRP-1 pathway raises interest in the search for such interaction inhibitors for the purpose of the early diagnosis and treatment of angiogenesis-dependent diseases. In this work we designed and tested peptide-based radiocompounds that selectively bind to the neuropilin-1 co-receptor and prevent the formation of the pro-angiogenic VEGF-A₁₆₅/NRP-1 complex. Three biomolecules, A7R and retro-inverso ^DR7A peptides, and the branched peptidomimetic Lys(hArg)-Dab-Pro-Arg (K4R), conjugated with macrocyclic chelator through two linkers' types, were labeled with theranostic scandium-44 radionuclide, and studied in vitro as potential targeted radiopharmaceuticals. ELISA (enzyme-linked immunosorbent assay) studies showed no negative effect of the introduced biomolecules' changes and high NRP-1 affinity in the case of A7R- and K4R-radiocompounds and a lack affinity for ^DR7A-radiocompounds. All radiopeptides showed a hydrophilic nature as well as high stability against ligand exchange reactions in cysteine/histidine solutions. Unfortunately, all radiocompounds showed unsatisfactory nano-scale stability in human serum, especially for use as therapeutic radioagents. Further work is ongoing and focused on the search for angiogenesis inhibitors that are more human serum stable.

Using a zebrafish xenograft tumor model to compare the efficacy and safety of VEGFR-TKIs

PURPOSE

We constructed a zebrafish xenograft tumor model to compare and quantify the antiangiogenic efficacy and safety of nine vascular endothelial growth factor receptor-tyrosine kinase inhibitors (VEGFR-TKIs), axitinib, lenvatinib, pazopanib, apatinib, cabozantinib, sunitinib, semaxanib, sorafenib, and regorafenib, in parallel.

METHODS

CT26 and GL261 tumor cells were implanted into the perivitelline space of Tg (flk1: eGFP) zebrafish to construct a xenograft tumor model. VEGFR-TKIs' antiangiogenic efficacy was quantified using AngioTool software, and the median effective dose (ED50) was calculated. The toxicity was evaluated by calculating the median lethal dose (LD50) and gross morphological changes. Cardiac toxicity was further assessed by heart rate, heart rhythm, the distance between the sinus venosus (SV) and bulbus arteriosus (BA), and pericardial edema.

RESULTS

Using the zebrafish xenograft tumor model, we found that all nine VEGFR-TKIs exhibited antiangiogenic abilities, but the effectiveness of semaxanib was worse than that of other VEGFR-TKIs. Meanwhile, the zebrafish toxicity assay showed that all tested VEGFR-TKIs were associated with cardiac-related toxicity, especially apatinib and axitinib, which caused serious pericardial edema in zebrafish at relatively low concentrations. A narrow therapeutic window was found for most VEGFR-TKIs, and the simultaneous occurrence of toxic effects of semaxanib was recognized.

CONCLUSION

Our findings showed the potential of using a zebrafish xenograft tumor model to accelerate VEGFR-TKI screening and further the development of more efficient and less toxic VEGFR-TKIs.

Nanoplastics exposure induces vascular malformation by interfering with the VEGFA/VEGFR pathway in zebrafish (Danio rerio)

The widespread accumulation and adverse effects of nanoplastics (NPs) are a growing concern for environmental and human health. However, the potential toxicological effects of nanoplastics, especially on vascular development, have not been well studied. In this study, the zebrafish model was utilized to systematically study the developmental toxicity of nanoplastics exposure at different concentrations with morphological, histological, and molecular levels. The results revealed developmental defects in zebrafish embryos after exposure to different concentrations of nanoplastics. Specifically, the morphological deformities, including pericardial oedema and spine curvature, as well as the abnormal body length and the rates of survival and hatching were induced after nanoplastics exposure in zebrafish embryos. In addition, we found that nanoplastics exposure could induce vascular malformation, including the ectopic sprouting of intersegmental vessels (ISVs), malformation of superficial ocular vessels (SOVs), and overgrowth of the common cardinal vein (CCV), as well as the disorganized vasculature of the subintestinal venous plexus (SIVP). Moreover, further study indicated that SU5416, a specific vascular endothelial growth factor receptor (VEGFR) inhibitor, partially rescued the nanoplastics exposure-impaired vasculature, suggesting that the VEGFA/VEGFR pathway might be associated with nanoplastics-induced vascular malformation in zebrafish embryos. Further quantitative polymerase chain reaction assays revealed that the mRNA levels of VEGFA/VEGFR pathway-related genes, including vegfa, nrp1, klf6a, flt1, fih-1, flk1, cldn5a, and rspo3, were altered in different groups, indicating that nanoplastics exposure interferes with the VEGFA/VEGFR pathway, thereby inducing vascular malformation during the early developmental stage in zebrafish embryos. Therefore, our findings illustrated that nanoplastics might induce vascular malformation by regulating VEGFA/VEGFR pathway-related genes at the early developmental stage in zebrafish.

Synthesis of Palladium-Catalysed C-C Bond Forming 5-Chloro Quinolines via Suzuki-Miyaura Coupling; Anti-Pancreatic Cancer Screening on PANC-1 Cell Lines

Pancreatic cancer is the most severe among other cancers due to its late detection and less chance of survivability. Heterocycles are proven ring systems in the treatment of various cancers and this is due to the presence of two biodynamic molecules combined, which have a greater synergistic efficacy in many anticancer drugs. Quinoline and pyridine ring systems are brought together to obtain greater potency and this is achieved by coupling both using Pd-catalyst, and in the present investigation, Suzuki-Miyaura coupling (SMC) reactions are adopted to generate potent molecular entities. Pancreatic cancer is difficult to treat due to overexpression of the VEGFR2 protein. VEGFR2 is targeted to design the molecules of quinoline-coupled pyridine moieties and is docked to evaluate the protein-ligand interaction at the binding site. The binding affinity of conjugates revealed the potency and capability of ligands to inhibit the VEGFR2 pathway. The in-silico ADMET properties determined their inherent pharmacokinetic feasibility. The synthesized conjugates have been evaluated by MTT assay against the human pancreatic cancer cell lines (PANC-1). Among the series, compounds 5d, 5e, and 5h exhibited a greater inhibitory activity against the cell lines with an IC₅₀ value of 82.32±1.38, 54.74±1.18 and 80.35±1.68 μM. In the present exploration, 5e exhibited greater inhibitory activity and it could be a promising lead for the development of new chemotherapeutics against pancreatic cancer.

Prognostic Impact of the Angiogenic Gene POSTN and Its Related Genes on Lung Adenocarcinoma

Background

The function of angiogenesis-related genes (ARGs) in lung adenocarcinoma (LUAD) remains poorly documented. This study was designed to reveal ARGs in LUAD and related networks.

Methods

We worked with sequencing data and clinical information pertaining to LUAD from public databases. ARGs were retrieved from the HALLMARK_ANGIOGENESIS gene set. Differential analysis and Kaplan–Meier (K–M) analysis were performed to authenticate the ARGs associated with LUAD. Weighted gene correlation network analysis was performed on the mining hub genes linked to the abovementioned genes, and functional enrichment analysis was done. Subsequently, Cox regression analyses were used to construct the prognostic gene. POSTN and microvessel density were detected using immunohistochemistry.

Results

POSTN, an ARG that was highly expressed in patients with LUAD and was closely associated with their weak overall survival was identified. Differentially expressed genes associated with POSTN were mainly enriched in entries related to the tubulointerstitial system, immune response, and epithelial cells. A positive correlation was demonstrated between POSTN expression and tumor microvessel density in LUAD. Subsequently, a prognostic gene signature was constructed and revealed that 4 genes may predict the survival of LUAD patients. Furthermore, the ESTIMATE and CIBERSORT analyses suggested that our risk scoring system may be implicated in altering the immune microenvironment of patients with LUAD. Finally, a ceRNA network was constructed based on the prognostic genes, and the regulatory networks were examined.

Conclusion

POSTN, a novel prognostic gene signature associated with ARGs, was constructed for the prognosis of patients with LUAD. This signature may alter the immune microenvironment by modulating the activation of the tubulointerstitial system, epithelial cells, and immune cells, ultimately affecting patient survival.

New Advances in Targeted Therapy of HER2-Negative Breast Cancer

Breast cancer has an extremely high incidence in women, and its morbidity and mortality rank first among female tumors. With the increasing development of molecular biology and genomics, molecular targeted therapy has become one of the most active areas in breast cancer treatment research and has also achieved remarkable achievements. However, molecular targeted therapy is mainly aimed at HER2-positive breast cancer and has not yet achieved satisfactory curative effect on HER2-negative breast cancer. This article describes the potential targets that may be used for breast cancer treatment from the aspects of PI3K/AKT signaling pathway, DDR, angiogenesis, the cell cycle, breast cancer stem cells, etc., and explores possible inhibitors for the treatment of HER2-negative breast cancer, such as PI3K inhibitors, AKT inhibitors and m-TOR inhibitors that inhibit the PI3K/AKT signaling pathway, small molecule tyrosine kinase inhibitors that restrain angiogenesis, CDK inhibitors, aurora kinase inhibitors and HDAC inhibitors that block cell cycle, as well as the drugs targeting breast cancer stem cells which have been a hit, aiming to provide a new idea and strategy for the treatment of HER2-negative breast cancer.

How the structural properties of the indole derivatives are important in kinase targeted drug design?: A case study on tyrosine kinase inhibitors

Kinases are considered as important signalling enzymes that illustrate 20% of the druggable genome. Human kinase family comprises >500 protein kinases and about 20 lipid kinases. Protein kinases are responsible for the mechanism of protein phosphorylation. These are necessary for regulation of various cellular activities including proliferation, cell cycle, apoptosis, motility, growth, differentiation, etc. Their deregulation leads to disruption of many cellular processes leading to different diseases most importantly cancer. Thus, kinases are considered as valuable targets in different types of cancer as well as other diseases. Researchers around the world are actively engaged in developing inhibitors based on distinct chemical scaffolds. Indole represents as a versatile scaffold in the naturally occurring and bioactive molecules. It is also used as a privileged scaffold for the target-based drug design against different diseases. This present article aim to review the applications of indole scaffold in the design of inhibitors against different tyrosine kinases such as epidermal growth factor receptors (EGFRs), vascular endothelial growth factor receptors (VEGFRs), platelet-derived growth factor receptors (PDGFRs), etc. Important structure activity relationships (SARs) of indole derivatives were discussed. The present work is an attempt to summarize all the crucial structural information which is essential for the development of indole based tyrosine kinase inhibitors with improved potency.

Synthesis, Physicochemical and Biological Study of Gallium-68- and Lutetium-177-Labeled VEGF-A165/NRP-1 Complex Inhibitors Based on Peptide A7R and Branched Peptidomimetic

Neuropilin-1 (NRP-1) is a surface receptor found on many types of cancer cells. The overexpression of NRP-1 and its interaction with vascular endothelial growth factor-165 (VEGF₁₆₅) are associated with tumor growth and metastasis. Therefore, compounds that block the VEGF₁₆₅/NRP-1 interaction represent a promising strategy to image and treat NRP-1-related pathologies. The aim of the presented work was to design and synthesize radioconjugates of two known peptide-type inhibitors of the VEGF₁₆₅/NRP-1 complex: A7R peptide and its shorter analog, the branched peptidomimetic Lys(hArg)-Dab-Pro-Arg. Both peptide-type inhibitors were coupled to a radionuclide chelator (DOTA) via a linker (Ahx) and so radiolabeled with Ga-68 and Lu-177 radionuclides, for diagnostic and therapeutic uses, respectively. The synthesized radioconjugates were tested for their possible use as theranostic-like radiopharmaceuticals for the imaging and therapy of cancers that overexpress NRP-1. The obtained results indicate good efficiency of the radiolabeling reaction and satisfactory stability, at least 3t_1/2 for the ⁶⁸Ga- and 1t_1/2 for the ¹⁷⁷Lu-radiocompounds, in solutions mimicking human body fluids. However, enzymatic degradation of both the studied inhibitors caused insufficient stability of the radiocompounds in human serum, indicating that further modifications are needed to sufficiently stabilize the peptidomimetics with inhibitory properties against VEGF₁₆₅/NRP-1 complex formation.

LncRNA FGD5-AS1 accelerates intracerebral hemorrhage injury in mice by adsorbing miR-6838-5p to target VEGFA

Intracerebral hemorrhage (ICH) can usually cause severe neuroinflammation and blood-brain barrier (BBB) damage. Previous studies supported the important role of long non-coding RNAs (lncRNAs) in ICH treatment. This study aimed to explore the effect of lncRNA FGD5 antisense RNA 1 (FGD5-AS1) on ICH and its potential molecular mechanisms. C57BL/6 mice were injected with collagenase VII to establish an ICH mice model. In addition, brain cerebral microvascular endothelial cells (BMVECs) were treated by oxygen-glucose deprivation (OGD)/hemin to simulate ICH. RT-qPCR revealed that FGD5-AS1 was upregulated in serum of ICH patients and mice and in OGD/hemin-treated BMVECs. Luciferase reporter gene and pull-down assays predicted and verified that FGD5-AS1 bound to miR-6838-5p, and VEGFA was a target of miR-6838-5p. FGD5-AS1 knockdown decreased the inflammatory factor contents in brain tissues and BMVECs. FGD5-AS1 overexpression inhibited cell proliferation, invasion and tight junction protein levels, and promoted apoptosis, increased the permeability of BBB and secretion of pro-inflammatory factors. In addition, miR-6838-5p knockdown reversed the inhibitory effect of FGD5-AS1 knockdown on the PI3K/Akt signaling pathway. In conclusion, FGD5-AS1 may act as an important regulator to promote apoptosis, cell permeability and inflammatory response of BMVECs via the miR-6838-5p/VEGFA axis in ICH mice.

Targeting VEGFR-2 by new quinoxaline derivatives: Design, synthesis, antiproliferative assay, apoptosis induction, and in silico studies

Twelve new triazolo[4,3-a]quinoxaline-based compounds are reported as anticancer agents with potential effects against vascular endothelial growth factor receptor-2 (VEGFR-2), using sorafenib as a reference molecule. With sorafenib as the positive control, the antiproliferative effects of the synthesized compounds against MCF-7 and HepG2 cells, as well as their VEGFR-2-inhibitory activities, were assessed. The most powerful VEGFR-2 inhibitor was compound 14a, which had an IC₅₀ value of 3.2 nM, which is very close to that of sorafenib (IC₅₀  = 3.12 nM). Furthermore, compounds 14c and 15d showed potential inhibitory activity against VEGFR-2, with IC₅₀ values of 4.8 and 5.4 nM, respectively. Compound 14a caused apoptosis in HepG2 cells and stopped the cell cycle at the G2/M phase. In HepG2 cells, it also increased the levels of the proteases caspase-3 and caspase-9, as well as the Bax/Bcl-2 ratio. In silico ADMET (absorption, distribution, metabolism, excretion, and toxicity) and toxicity experiments revealed that the synthesized agents had acceptable drug-likeness.

Recent advances in, and challenges of, anti-angiogenesis agents for tumor chemotherapy based on vascular normalization

A major problem associated with cancer treatment is resistance-prone chemotherapeutic drugs. An increasing number of studies have documented that the occurrence of resistance tends to be associated with abnormal blood vessels. In 2001, Jain proposed the vascular normalization theory, which was recently applied to the drug-resistant treatment of tumors in the clinic. Through the intervention of angiogenesis inhibitors, remodeling the structure and function of abnormal vessels can maximize the efficacy of chemotherapeutic drugs. In this review, we systematically describe the occurrence and progress of tumor angiogenesis, as well as the pathological characteristics of tumor blood vessels. Moreover, druggable targets for vascular normalization and the development of related inhibitors are also outlined.

Pharmacological Activities and Mechanisms of Hirudin and Its Derivatives - A Review

Hirudin, an acidic polypeptide secreted by the salivary glands of Hirudo medicinalis (also known as "Shuizhi" in traditional Chinese medicine), is the strongest natural specific inhibitor of thrombin found so far. Hirudin has been demonstrated to possess potent anti-thrombotic effect in previous studies. Recently, increasing researches have focused on the anti-thrombotic activity of the derivatives of hirudin, mainly because these derivatives have stronger antithrombotic activity and lower bleeding risk. Additionally, various bioactivities of hirudin have been reported as well, including wound repair effect, anti-fibrosis effect, effect on diabetic complications, anti-tumor effect, anti-hyperuricemia effect, effect on cerebral hemorrhage, and others. Therefore, by collecting and summarizing publications from the recent two decades, the pharmacological activities, pharmacokinetics, novel preparations and derivatives, as well as toxicity of hirudin were systematically reviewed in this paper. In addition, the clinical application, the underlying mechanisms of pharmacological effects, the dose-effect relationship, and the development potential in new drug research of hirudin were discussed on the purpose of providing new ideas for application of hirudin in treating related diseases.

Recent Progress in the Development of Quinoline Derivatives for the Exploitation of Anti-Cancer Agents

BACKGROUND

Along with the progress in medicine and therapies, the exploitation of anti-cancer agents focused more on the vital signaling pathways and key biological macromolecules. With rational design and advanced synthesis, quinoline derivatives have been utilized frequently in medicinal chemistry, especially in developing anti-cancer drugs or candidates.

METHODS

Using DOI searching, articles published before 2020 all over the world have been reviewed as comprehensively as possible.

RESULTS

In this review, we selected the representative quinoline derivate drugs in market or clinical trials, classified them into five major categories with detailed targets according to their main mechanisms, discussed the relationship within the same mechanism, and generated a summative discussion with prospective expectations. For each mechanism, the introduction of the target was presented, with the typical examples of quinoline derivate drugs.

CONCLUSION

This review has highlighted the quinoline drugs or candidates, suited them into corresponding targets in their pathways, summarized and discussed. We hope that this review may help the researchers who are interested in discovering quinoline derivate anti-cancer agents obtain considerable understanding of this specific topic. Through the flourishing period and the vigorous strategies in clinical trials, quinoline drugs would be potential but facing new challenges in the future.

Liposomal Nanosystems in Rheumatoid Arthritis

Rheumatoid arthritis (RA) is an autoimmune disease that affects the joints and results in reduced patient quality of life due to its chronic nature and several comorbidities. RA is also associated with a high socioeconomic burden. Currently, several available therapies minimize symptoms and prevent disease progression. However, more effective treatments are needed due to current therapies' severe side-effects, especially under long-term use. Drug delivery systems have demonstrated their clinical importance-with several nanocarriers present in the market-due to their capacity to improve therapeutic drug index, for instance, by enabling passive or active targeting. The first to achieve market authorization were liposomes that still represent a considerable part of approved delivery systems. In this manuscript, we review the role of liposomes in RA treatment, address preclinical studies and clinical trials, and discuss factors that could hamper a successful clinical translation. We also suggest some alterations that could potentially improve their progression to the market.

Increased angiogenesis and migration of dermal microvascular endothelial cells from patients with psoriasis

Psoriasis displays both increased angiogenesis and microvascular dilation in the skin, while human dermal microvascular endothelial cells (HDMECs) are involved in angiogenesis and microvascular dilation. Whether the functions of HDMECs are altered in psoriatic skin versus healthy skin remain unknown. Here, we isolated HDMECs from the skin of 10 patients with psoriasis and 10 healthy subjects and compared angiogenesis, proliferation, migration and cell metabolism between psoriatic HDMECs and normal HDMECs. We found that the morphology of primary HDMECs was comparable between psoriatic HDMECs and normal HDMECs. After passage, psoriatic HDMECs displayed larger cell size and wider intercellular space. In addition to DiI-Ac-LDL (DiI-labelled acetylated low-density lipoprotein) uptake, expression levels of CD31, vWF (von Willebrand factor) and LYVE-1 were comparable in psoriatic HDMECs versus normal HDMECs. However, psoriatic HDMECs exhibited increased tube formation (numbers of nodes and meshes, p < 0.05) and migration (numbers of migrated cells, p < 0.001) and reductions in proliferation (growth rates, p < 0.05) and energy metabolism (oxygen consumption rate and extracellular acidification rate, p < 0.05) compared with normal HDMECs. Therefore, psoriatic HDMECs display an increased angiogenesis and migration and decreased proliferation and metabolic activity, suggesting a pathogenic role of HDMECs in psoriasis.

The Role of VEGF Receptors as Molecular Target in Nuclear Medicine for Cancer Diagnosis and Combination Therapy

Simple Summary

The rapid development of diagnostic and therapeutic methods of the cancer treatment causes that these diseases are becoming better known and the fight against them is more and more effective. Substantial contribution in this development has nuclear medicine that enables very early cancer diagnosis and early start of the so-called targeted therapy. This therapeutic concept compared to the currently used chemotherapy, causes much fewer undesirable side effects, due to targeting a specific lesion in the body. This review article discusses the possible applications of radionuclide-labelled tracers (peptides, antibodies or synthetic organic molecules) that can visualise cancer cells through pathological blood vessel system in close tumour microenvironment. Hence, at a very early step of oncological disease, targeted therapy can involve in tumour formation and growth.

Abstract

One approach to anticancer treatment is targeted anti-angiogenic therapy (AAT) based on prevention of blood vessel formation around the developing cancer cells. It is known that vascular endothelial growth factor (VEGF) and vascular endothelial growth factor receptors (VEGFRs) play a pivotal role in angiogenesis process; hence, application of angiogenesis inhibitors can be an effective approach in anticancer combination therapeutic strategies. Currently, several types of molecules have been utilised in targeted VEGF/VEGFR anticancer therapy, including human VEGF ligands themselves and their derivatives, anti-VEGF or anti-VEGFR monoclonal antibodies, VEGF binding peptides and small molecular inhibitors of VEGFR tyrosine kinases. These molecules labelled with diagnostic or therapeutic radionuclides can become, respectively, diagnostic or therapeutic receptor radiopharmaceuticals. In targeted anti-angiogenic therapy, diagnostic radioagents play a unique role, allowing the determination of the emerging tumour, to monitor the course of treatment, to predict the treatment outcomes and, first of all, to refer patients for AAT. This review provides an overview of design, synthesis and study of radiolabelled VEGF/VEGFR targeting and imaging agents to date. Additionally, we will briefly discuss their physicochemical properties and possible application in combination targeted radionuclide tumour therapy.

Overview of current targeted therapy in gallbladder cancer

Gallbladder cancer (GBC) is rare, but is the most malignant type of biliary tract tumor. Unfortunately, only a small population of cancer patients is acceptable for the surgical resection, the current effective regimen; thus, the high mortality rate has been static for decades. To substantially circumvent the stagnant scenario, a number of therapeutic approaches owing to the creation of advanced technologic measures (e.g., next-generation sequencing, transcriptomics, proteomics) have been intensively innovated, which include targeted therapy, immunotherapy, and nanoparticle-based delivery systems. In the current review, we primarily focus on the targeted therapy capable of specifically inhibiting individual key molecules that govern aberrant signaling cascades in GBC. Global clinical trials of targeted therapy in GBC are updated and may offer great value for novel pathologic and therapeutic insights of this deadly disease, ultimately improving the efficacy of treatment.

Prognosis and targeting of pre-metastatic niche

As the main cause of tumoral fatality, metastasis remains to be one of the most urgent difficulties researcher struggled to overcome. During the development and progression of metastasis, the establishment of pre-metastatic niche is crucial in preparing fertile microenvironment for disseminated tumor cells settlement and colonization in distant metastatic target sites. The key participators, including the primary tumor-derived factors, bone marrow-derived cells, stromal cells of both the host and the potential metastatic sites, regulate the temporal progress of potential metastasis. Firstly, pioneers are sent from primary tumor, recruiting immunosuppressive cells; then circulating tumor cells settled and colonized; and finally, micrometastases develop. Here, we summarize the therapeutic strategies presented in recent years targeting different stages of the pre-metastatic niche formation and discuss their chances and challenges in clinical translation, providing promising approaches for metastasis prevention and therapeutic interventions.

Hirudin reduces nephropathy microangiopathy in STZ-induced diabetes rats by inhibiting endothelial cell migration and angiogenesis

OBJECTIVE

Kidney is the most common location of microangiopathy in diabetic patients, and we designed this study to investigate the effects of hirudin on renal microangiopathy in STZ-induced diabetes rats and in vitro.

METHODS

We established a diabetes model by intraperitoneal injection of STZ and administered hirudin daily by subcutaneous injection. HE staining was used to assess kidney pathological changes. Western blot and immunochemistry was used to detect the protein expression. Glomerular endothelial cells (GEC) in normal rats were assessed by cell scratch test for migration ability and tubule formation experiment for angiogenesis ability.

RESULTS

Compared with DN rats without any treatment, the serum creatinine, serum Cys C, 24-hour urine protein of DN rats with hirudin treatment were significantly decrease, the kidney/body weight and glomerular area of DN rats with hirudin treatment were all significantly decrease, and also significant improvement in renal pathology revealed by HE staining in DN rats after treating with hirudin. Moreover, we also found that hirudin coun not only significantly increase the prothrombin time and aivated partial thromboplastin time in DN rats, but also significantly decrease the expression of VEGF and TM-1 protein in kidney tissues of DN rats. In vitro, we found that high glucose could promote the migration and angiogensis of GEC, and significantly increased the expression of VEGF and Ang protein, but significantly decreased the expression of THBS1 and Arg1 protein. More importantly was that hirudin could inhibit the migration and angiogensis of GEC, and reversed HG-induced the expression of VEGF, Ang, THBS1 and Arg1 protein in GEC. In addition, we also found that hirudin could not only decrease HG-enhanced the activity of RhoA in GEC, but also decrease HG-enhanced the expression of p-MYPT1/MYPT1, p-p38/p38 protein in GEC.

CONCLUSION

Hirudin reduces nephropathy microangiopathy in STZ-induced diabetes, and might be related to hirudin inhibiting glomerular endothelial cell migration and angiogenesis through Rho-kinase and subsequent p38MAPK/NF-kB signaling pathway.

Anti-placental growth factor antibody ameliorates hyperoxia-mediated impairment of lung development in neonatal rats

This study investigates the effect of the overexpression of the placental growth factor (PGF) and hyperoxia on lung development and determines whether anti-PGF antibody ameliorates hyperoxia-mediated impairment of lung development in newborn rats. After exposure to normoxic conditions for seven days, newborn rats subjected to normoxia were intraperitoneally or intratracheally injected with physiological saline, adenovirus-negative control (Ad-NC), or adenovirus-PGF (Ad-PGF) to create the Normoxia, Normoxia+Ad-NC, and Normoxia+Ad-PGF groups, respectively. Newborn rats subjected to hyperoxia were intraperitoneally injected with physiological saline or anti-PGF antibodies to create the Hyperoxia and Hyperoxia+anti-PGF groups, respectively. Our results revealed significant augmentation in the levels of PGF and its receptor Flt-1 in the lung tissues of newborn rats belonging to the Normoxia+Ad-PGF or Hyperoxia groups. PGF overexpression in these groups caused lung injury in newborn rats, while anti-PGF antibody treatment significantly cured the hyperoxia-induced lung injury. Moreover, PGF overexpression significantly increased TNF-α and Il-6 levels in the bronchoalveolar lavage (BAL) fluid of the Normoxia+Ad-PGF and Hyperoxia groups. However, their levels were significantly reduced in the BAL fluid of the Hyperoxia+anti-PGF group. Immunohistochemical analysis revealed that PGF overexpression and hyperoxia treatment significantly increased the expression of the angiogenesis marker, CD34. However, its expression was significantly decreased upon administration of anti-PGF antibodies (compared to the control group under hyperoxia). In conclusion, PGF overexpression impairs lung development in newborn rats while its inhibition using an anti-PGF antibody ameliorates the same. These results provided new insights for the clinical management of bronchopulmonary dysplasia in premature infants.

Dual Action of Sulfated Hyaluronan on Angiogenic Processes in Relation to Vascular Endothelial Growth Factor-A

Pathological healing characterized by abnormal angiogenesis presents a serious burden to patients’ quality of life requiring innovative treatment strategies. Glycosaminoglycans (GAG) are important regulators of angiogenic processes. This experimental and computational study revealed how sulfated GAG derivatives (sGAG) influence the interplay of vascular endothelial growth factor (VEGF)₁₆₅ and its heparin-binding domain (HBD) with the signaling receptor VEGFR-2 up to atomic detail. There was profound evidence for a HBD-GAG-HBD stacking configuration. Here, the sGAG act as a “molecular glue” leading to recognition modes in which sGAG interact with two VEGF₁₆₅-HBDs. A 3D angiogenesis model demonstrated the dual regulatory role of high-sulfated derivatives on the biological activity of endothelial cells. While GAG alone promote sprouting, they downregulate VEGF₁₆₅-mediated signaling and, thereby, elicit VEGF₁₆₅-independent and -dependent effects. These findings provide novel insights into the modulatory potential of sGAG derivatives on angiogenic processes and point towards their prospective application in treating abnormal angiogenesis.

Association between vascular endothelial growth factor receptor 2 rs11941492 C/T polymorphism and Chinese Han patients in rheumatoid arthritis

The aim of the present study was to examine the association between vascular endothelial growth factor receptor 2 (VEGFR2) rs11941492 C/T polymorphism and rheumatoid arthritis (RA) risk in an eastern Chinese Han population. We examined VEGFR2 rs11941492 C/T polymorphism in 615 RA patients and 839 controls in an East Chinese Han population. The power analysis was used for evaluating the reliability of the results. Genotyping was performed using a custom-by-design 48-Plex single nucleotide polymorphism scan Kit. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using logistic regression.Our results indicated that VEGFR2 rs11941492 C/T polymorphism (TT vs CC, P = .012, OR = 0.61, 95% CI = 0.41-0.89; TT vs CT + CC, P = .017, OR = 0.63, 95% CI = 0.43-0.92) was associated with a significantly decreased risk of RA. The power analysis showed that this study had a power of 98.5% to detect the effect of rs11941492 C/T polymorphism on RA susceptibility, assuming an OR of 0.61. After stratification analysis, a decreased risk of RA was associated with VEGFR2 rs11941492 TT genotype (TT vs CC) among female patients (TT vs CC, P = .007, OR = 0.53, 95% CI = 0.33-0.84), older patients (Yr ≥55) (TT vs CC, P = .039, OR = 0.58, 95% CI = 0.35-0.97), C-reactive protein-positive patients, anti-cyclic citrullinated peptide antibody-negative patients, rheumatoid factor-positive patients (TT vs CT + CC, P = .015, OR = 0.60, 95% CI = 0.39-0.90), functional class III + IV patients, patients with a DAS28 of ≥3.20, and those with an erythrocyte sedimentation rate of <25. However, our results were obtained from only a moderate-sized sample. Studies with larger sample sizes in other ethnic populations are needed to confirm these results. The VEGFR2 rs11941492 genotype is associated with decreased susceptibility to RA.

VEGF/Flk1 Mechanism is Involved in Roxarsone Promotion of Rat Endothelial Cell Growth and B16F10 Xenograft Tumor Angiogenesis

The potential angiogenic effect of roxarsone, a feed additive widely used to promote animal growth worldwide, was demonstrated recently. We explored the mechanism of vascular endothelial growth factor (VEGF) and its receptor (VEGFR) in roxarsone promotion of rat vascular endothelial cells (ECs) and B16F10 mouse xenografts. ECs were treated with 0.1–50 μM roxarsone or with roxarsone plus 10 ng/mL VEGF, VEGFR1 (Flt1), or VEGFR2 (Flk1) antibodies for 12–48 h to examine their role in cell growth promotion. Small interfering RNA (siRNA) targeting Vegf, Flt1, and Flk1 were transfected in the ECs, and we measured the expression level, cell proliferation, migration, and tube formation ability. The siRNA targeting Vegf or Flk1 were injected intratumorally in the B16F10 xenografts of mice that received 25 mg/kg roxarsone orally. Cell viability and VEGF expression following roxarsone treatment were significantly higher than that of the control (P < 0.05), peaking following treatment with 1.0 μM roxarsone. Compared to roxarsone alone, the VEGF antibody decreased cell promotion by roxarsone (P < 0.05), and the Flk1 antibody greatly reduced cell viability compared to the Flt1 antibody (P < 0.01). Roxarsone and Flk1 antibody co-treatment increased supernatant VEGF significantly, while cellular VEGF was obviously decreased (P < 0.01), whereas there was no significant difference following Flt1 antibody blockade. The siRNA against Vegf or Flk1 significantly attenuated the roxarsone promotion effects on EC proliferation, migration, and tube-like formation (P < 0.01), whereas the siRNA against Flt1 effected no obvious differences. Furthermore, the RNA interference significantly weakened the roxarsone-induced increase in xenograft weight and volume, and VEGF and Flk1 expression. Roxarsone promotion of rat EC growth, migration, and tube-like formation in vitro and of B16F10 mouse xenograft model tumor growth and angiogenesis involves a VEGF/Flk1 mechanism.

Association between VEGFA gene polymorphisms and bleeding complications in patients maintaining therapeutic international normalized ratio

Aim: This study was designed to identify the possible effects of VEGFA polymorphisms on the occurrence of bleeding complications in patients with mechanical heart valves who have achieved therapeutic international normalized ratio (INR). Materials & methods: 13 SNPs of VEGFA were analyzed. Uni- and multi-variate analyses were conducted to identify associations between polymorphisms and bleeding complications. Results & conclusion: Patients with the CC genotype of rs35410204 had an approximately tenfold higher bleeding complication than those with the T allele. For rs866236, patients who had wild-type homozygotes showed an approximately 2.9-fold higher bleeding complication than C allele carriers. This study demonstrated that bleeding complications during warfarin therapy are associated with VEGFA polymorphisms in patients with mechanical heart valves.

Combination Strategies Using EGFR-TKi in NSCLC Therapy: Learning from the Gap between Pre-Clinical Results and Clinical Outcomes

Although epidermal growth factor receptor (EGFR) inhibitors have been used to treat non-small cell lung cancer (NSCLC) for decades with great success in patients with EGFR mutations, acquired resistance inevitably occurs after long-term exposure. More recently, combination therapy has emerged as a promising strategy to overcome this issue. Several experiments have been carried out to evaluate the synergism of combination therapy both in vitro and in vivo. Additionally, many clinical studies have been carried out to investigate the feasibility of treatment with EGFR-tyrosine kinase inhibitors (TKi) combined with other NSCLC treatments, including radiotherapy, cytotoxic chemotherapies, targeted therapies, and emerging immunotherapies. However, a significant gap still exists when applying pre-clinical results to clinical scenarios, which hinders the development and use of these strategies. This article is a literature review analysing the rationalities and controversies in the transition from pre-clinical investigation to clinical practice associated with various combination strategies. It also highlights clues and challenges regarding future combination therapeutic options in NSCLC treatment.

Sulfated Hyaluronan Alters Endothelial Cell Activation in Vitro by Controlling the Biological Activity of the Angiogenic Factors Vascular Endothelial Growth Factor-A and Tissue Inhibitor of Metalloproteinase-3

Several pathologic conditions such as rheumatoid arthritis, ocular neovascularization, cancer, or atherosclerosis are often associated with abnormal angiogenesis, which requires innovative biomaterial-based treatment options to control the activity of angiogenic factors. Here, we studied how sulfated hyaluronan (sHA) and oversulfated chondroitin sulfate derivatives as potential components of functional biomaterials modulate vascular endothelial growth factor-A (VEGF-A) signaling and endothelial cell activity in vitro. Tissue inhibitor of metalloproteinase-3 (TIMP-3), an effective angiogenesis inhibitor, exerts its activity by competing with VEGF-A for binding to VEGF receptor-2 (VEGFR-2). However, even though TIMP-3 and VEGF-A are known to interact with glycosaminoglycans (GAGs), the potential role and mechanism by which GAGs alter the VEGF-A/TIMP-3 regulated VEGFR-2 signaling remains unclear. Combining surface plasmon resonance, immunobiochemical analysis, and molecular modeling, we demonstrate the simultaneous binding of VEGF-A and TIMP-3 to sHA-coated surfaces and identified a novel mechanism by which sulfated GAG derivatives control angiogenesis: GAG derivatives block the binding of VEGF-A and TIMP-3 to VEGFR-2 thereby reducing their biological activity in a defined, sulfation-dependent manner. This effect was stronger for sulfated GAG derivatives than for native GAGs. The simultaneous formation of TIMP-3/sHA complexes partially rescues the sHA inhibited VEGF-A/VEGFR-2 signaling and endothelial cell activation. These results provide novel insights into the regulation of angiogenic factors by GAG derivatives and highlight the potential of sHA derivatives for the treatment of diseases associated with increased VEGF-A and VEGFR-2 levels.

Anti-VEGFR2-interferon-α2 regulates the tumor microenvironment and exhibits potent antitumor efficacy against colorectal cancer

Interferon-α (IFNα) has multiple antitumor effects including direct antitumor toxicity and the ability to potently stimulate both innate and adaptive immunity. However, its clinical applications in the treatment of malignancies have been limited because of short half-life and serious adverse reactions when attempting to deliver therapeutically effective doses. To address these issues, we fused IFNα2a to the anti-vascular endothelial growth factor and receptor 2 (VEGFR2) antibody JZA00 with the goal of targeting it to the tumor microenvironment where it can stimulate the antitumor immune response. The fusion protein, JZA01, is effective against colorectal cancer by inhibiting angiogenesis, exhibiting direct cytotoxicity, and activating the antitumor immune response. Although JZA01 exhibited reduced IFNα2 activity in vitro compared with native IFNα2, VEGFR2 targeting permitted efficient antiproliferative, proapoptotic, antiangiogenesis, and immune-stimulating effects against the colorectal tumors HCT-116 and SW620. JZA01 showed in vivo efficacy in NOD-SCID mice-bearing established HCT-116 tumors. In conclusion, this study describes an antitumor immunotherapy that is highly promising for the treatment of colorectal cancer.

Tubeimoside-1 suppresses tumor angiogenesis by stimulation of proteasomal VEGFR2 and Tie2 degradation in a non-small cell lung cancer xenograft model

Tubeimoside-1 (TBMS1) is a potent anti-tumor phytochemical. Its functional and molecular mode of action, however, remains elusive so far. Since angiogenesis is essential for tumor progression and metastasis, we herein investigated the anti-angiogenic effects of the compound. In a non-small cell lung cancer (NSCLC) xenograft model we found that treatment of CD1 nu/nu mice with TBMS1 (5 mg/kg) significantly suppressed the growth and vascularization of NCI-H460 flank tumors. Moreover, TBMS1 dose-dependently reduced vascular sprouting in a rat aortic ring assay. In vitro, TBMS1 induced endothelial cell apoptosis without decreasing the viability of NSCLC tumor cells and inhibited the migration of endothelial cells by disturbing their actin filament organization. TBMS1 further stimulated the proteasomal degradation of vascular endothelial growth factor receptor-2 (VEGFR2) and Tie2 in endothelial cells, which down-regulated AKT/mTOR signaling. These findings indicate that TBMS1 represents a novel phytochemical for anti-angiogenic treatment of cancer and other angiogenesis-related diseases.

sMEK1 inhibits endothelial cell proliferation by attenuating VEGFR-2-dependent-Akt/eNOS/HIF-1α signaling pathways

The suppressor of MEK null (sMEK1) protein possesses pro-apoptotic activities. In the current study, we reveal that sMEK1 functions as a novel anti-angiogenic factor by suppressing vascular endothelial growth factor (VEGF)-induced cell proliferation, migration, and capillary-like tubular structure in vitro. In addition, sMEK1 inhibited the phosphorylation of the signaling components up- and downstream of Akt, including phospholipase Cγ1 (PLC-γ1), 3-phosphoinositide-dependent protein kinase 1 (PDK1), endothelial nitric oxide synthetase (eNOS), and hypoxia-inducible factor 1 (HIF-1α) during ovarian tumor progression via binding with vascular endothelial growth factor receptor 2 (VEGFR-2). Furthermore, sMEK1 decreased tumor vascularity and inhibited tumor growth in a xenograft human ovarian tumor model. These results supply convincing evidence that sMEK1 controls endothelial cell function and subsequent angiogenesis by suppressing VEGFR-2-mediated PI3K/Akt/eNOS signaling pathway. Taken together, our results clearly suggest that sMEK1 might be a novel anti-angiogenic and anti-tumor agent for use in ovarian tumor.

A novel polysaccharide from Sargassum integerrimum induces apoptosis in A549 cells and prevents angiogensis in vitro and in vivo

Many polysaccharides isolated from plants have exhibited promising antitumor activities. The aim of this study is to investigate the antitumor activity of the novel polysaccharide named SPS from Sargassum integerrimum, elucidate the underlying anticancer mechanism in a human lung cancer cell line A549, and evaluate its anti-angiogenic activity both in vitro and in vivo. The results show that SPS significantly reduces A549 cells viability in a dose- and time-dependent manner via MTT method. Flow cytometry analysis indicates that SPS could induce cell apoptosis, the loss of mitochondrial membrane potential (MMP), generation of reactive oxygen species (ROS) and G2/M phase cell cycle arrest of A549 cells. Up-regulation of the expressions of P53 and Bax, down-regulation of the expression of Bcl-2, and activation of cleaved caspase-3, caspase-9 and PARP are also detected by western blotting after the treatment of SPS. In addition, SPS inhibits the proliferation, migration and cord formation of human umbilical vein endothelial cells (HUVECs) in vitro, and prevents the vascular development of zebrafish embryos in vivo. Altogether, our data prove the anticancer and anti-angiogenesis properties of SPS, and provide further insights into the potential pharmacological application of SPS as antitumor and anti-angiogenic agent against lung cancer.

Activity of nintedanib in germ cell tumors

Germ cell tumors (GCTs) are the most frequent malignancy in male patients between 15 and 45 years of age. Cisplatin-based chemotherapy shows excellent cure rates, but patients with cisplatin-resistant GCTs have a poor prognosis. Nintedanib (BIBF 1120, Vargatef) inhibits the receptor classes vascular endothelial growth factor receptor, platelet derived growth factor receptor, and fibroblast growth factor receptor, and has shown activity against many tumors, as well as in idiopathic lung fibrosis and bleomycin-induced lung injury. Here, we investigated the antineoplastic and antiangiogenic properties of nintedanib in cisplatin-resistant and cisplatin-sensitive GCT cells, both alone and in combination with classical cytotoxic agents such as cisplatin, etoposide, and bleomycin. The half-maximal inhibitory concentration (IC50) of nintedanib was 4.5 ± 0.43 μmol/l, 3.1 ± 0.45 μmol/l, and 3.6 ± 0.33 μmol/l in cisplatin-sensitive NTERA2, 2102Ep, and NCCIT cells, whereas the IC50 doses of the cisplatin-resistant counterparts were 6.6 ± 0.37 μmol/l (NTERA2-R), 4.5 ± 0.83 μmol/l (2102Ep-R), and 6.1 ± 0.41 μmol/l (NCCIT-R), respectively. Single treatment with nintedanib induced apoptosis and resulted in a sustained reduction in the capacity of colony formation in both cisplatin-sensitive and cisplatin-resistant GCT cells. Cell cycle analysis showed that nintedanib induced a strong G0/G1-phase arrest in all investigated cell lines. Combination treatment with cisplatin did not result in additive, synergistic, or antagonistic effects. The in-vivo activity was studied using the chorioallantoic membrane assay and indicated the antiangiogenic potency of nintedanib with markedly reduced microvessel density. Topical treatment of inoculated tumor plaques resulted in a significant reduction of the tumor size. This indicates that nintedanib might be a promising substance in the treatment of GCT.

Synthesis and biological evaluation of novel oxazolo[5,4-d]pyrimidines as potent VEGFR-2 inhibitors

Tumor angiogenesis is mediated by vascular endothelial growth factor receptor (VEGFR) and other protein kinases. Inhibition of these kinases presents an attractive approach for developing anticancer therapeutics. In this work, a series of 2,5,7-trisubstituted oxazolo[5,4-d]pyrimidines were synthesized, and their inhibitory activities were investigated against VEGFR-2 and human umbilical vein endothelial cells (HUVEC) in vitro. Compound 9n exhibited the most potent inhibitory activity with IC50 values of 0.33 and 0.29 μM for VEGFR-2 kinase and HUVEC, respectively. A further kinase selectivity assay revealed that these compounds exhibit good VEGFR and moderate EGFR inhibitory activities. Docking analysis suggested a common mode of interaction at the ATP-binding site of VEGFR-2.

Novel investigational vascular endothelial growth factor (VEGF) receptor antagonists for psoriasis

INTRODUCTION

Affecting 1 million people in the UK, psoriasis is a commonly diagnosed inflammatory disease arising from autoimmune processes that are triggered by environmental factors in genetically susceptible individuals. The pathophysiology of psoriasis has been widely studied and there is evidence that angiogenesis is a key component.

AREAS COVERED

In this review the role of vascular endothelial growth factor-A (VEGF), as a key angiogenic mediator in psoriasis pathogenesis is discussed. VEGF is found in higher levels in plaques, normal skin and plasma of patients with psoriasis. The level of VEGF also fluctuates in accordance with disease activity and in response to conventional treatments. There are several VEGF inhibitors currently licenced for use; primarily in the fields of oncology and there are case reports of patients being treated with these therapies for metastatic cancer who have demonstrated significant improvement in their psoriasis. VEGF inhibitory agents have suggested promising utility for the treatment of psoriasis following animal studies.

EXPERT OPINION

VEGF may represent a novel treatment target in psoriasis. However, VEGF inhibitors can cause significant side effects such as hypertension and left ventricular dysfunction. The risks of treatment must be carefully evaluated before VEGF inhibitors are trialled or advocated for psoriasis.

PKN3 is the major regulator of angiogenesis and tumor metastasis in mice

PKN, a conserved family member related to PKC, was the first protein kinase identified as a target of the small GTPase Rho. PKN is involved in various functions including cytoskeletal arrangement and cell adhesion. Furthermore, the enrichment of PKN3 mRNA in some cancer cell lines as well as its requirement in malignant prostate cell growth suggested its involvement in oncogenesis. Despite intensive research efforts, physiological as well as pathological roles of PKN3 in vivo remain elusive. Here, we generated mice with a targeted deletion of PKN3. The PKN3 knockout (KO) mice are viable and develop normally. However, the absence of PKN3 had an impact on angiogenesis as evidenced by marked suppressions of micro-vessel sprouting in ex vivo aortic ring assay and in vivo corneal pocket assay. Furthermore, the PKN3 KO mice exhibited an impaired lung metastasis of melanoma cells when administered from the tail vein. Importantly, PKN3 knock-down by small interfering RNA (siRNA) induced a glycosylation defect of cell-surface glycoproteins, including ICAM-1, integrin β1 and integrin α5 in HUVECs. Our data provide the first in vivo genetic demonstration that PKN3 plays critical roles in angiogenesis and tumor metastasis, and that defective maturation of cell surface glycoproteins might underlie these phenotypes.

Investigation of new 2-aryl substituted Benzothiopyrano[4,3-d]pyrimidines as kinase inhibitors targeting vascular endothelial growth factor receptor 2

Vascular Endothelial Growth Factor (VEGF) pathway has emerged as one of the most important positive modulators of Angiogenesis, a central process implicated in tumour growth and metastatic dissemination. This led to the design and development of anti-VEGF monoclonal antibodies and small-molecule ATP-competitive VEGFR-inhibitors. In this study, we describe the synthesis and the biological evaluation of novel 2-aryl substituted benzothiopyrano-fused pyrimidines 1a-i, 2a-i and 3a-i. The ability of the compounds to target the VEGF pathway was determined in vitro exploiting the compounds' antiproliferative efficacy against HUVEC cells. The VEGFR-2 inhibition was confirmed by enzymatic assays on recombinant human kinase insert domain receptor (KDR), by cell-based phospho-VEGFR-2 inhibition assays, and by ex vivo rat aortic ring tests. The selectivity profile of the best performing derivatives belonging to series 2 was further explored combining modeling studies and additional assays in a panel of human cell lines and other kinases.

The Histone Methyltransferase Inhibitor BIX01294 Inhibits HIF-1α Stability and Angiogenesis

Hypoxia-inducible factor (HIF) is a key regulator of tumor growth and angiogenesis. Recent studies have shown that, BIX01294, a G9a histone methyltransferase (HMT)-specific inhibitor, induces apoptosis and inhibits the proliferation, migration, and invasion of cancer cells. However, not many studies have investigated whether inhibition of G9a HMT can modulate HIF-1α stability and angiogenesis. Here, we show that BIX01294 dose-dependently decreases levels of HIF-1α in HepG2 human hepatocellular carcinoma cells. The half-life of HIF-1α, expression of proline hydroxylase 2 (PHD2), hydroxylated HIF-1α and von Hippel-Lindau protein (pVHL) under hypoxic conditions were decreased by BIX01294. The mRNA expression and secretion of vascular endothelial growth factor (VEGF) were also significantly reduced by BIX01294 under hypoxic conditions in HepG2 cells. BIX01294 remarkably decreased angiogenic activity induced by VEGF in vitro, ex vivo, and in vivo, as demonstrated by assays using human umbilical vein endothelial cells (HUVECs), mouse aortic rings, and chick chorioallantoic membranes (CAMs), respectively. Furthermore, BIX01294 suppressed VEGF-induced matrix metalloproteinase 2 (MMP2) activity and inhibited VEGF-induced phosphorylation of VEGF receptor 2 (VEGFR-2), focal adhesion kinase (FAK), and paxillin in HUVECs. In addition, BIX01294 inhibited VEGF-induced formation of actin cytoskeletal stress fibers. In conclusion, we demonstrated that BIX01294 inhibits HIF-1α stability and VEGF-induced angiogenesis through the VEGFR-2 signaling pathway and actin cytoskeletal remodeling, indicating a promising approach for developing novel therapeutics to stop tumor progression.