VEGF Receptor Research Articles

Platelet-rich plasma promotes wound repair in diabetic foot ulcer mice via the VEGFA/VEGFR2/ERK pathway

Diabetic foot ulcers (DFUs) are a severe microvascular complication. Platelet-rich plasma (PRP) pitches in DFU treatment. This study explored the mechanism of PRP facilitating wound repair in DFU mice via vascular endothelial growth factor A (VEGFA)/VEGF receptor 2 (VEGFR2)/extracellular signal-regulated kinase (ERK) pathway. The DFU mouse model was established, with wound skin injected with PRP, followed by the detections of wound area, histopathological changes, and CD31-positive cells. IL-6/TNF-α/VEGFA/VEGFR2/p-VEGFR2/(ERK1/2)/(p-ERK1/2) levels in wound tissue homogenates were assessed. VEGFA-VEGFR2 interaction was evaluated. PRP-treated DFU mice were simultaneously treated with fruquintinib/PD98059. PRP reduced wound area, IL-6 and TNF-α levels, elevated epidermal dermal thickness, CD31-positive cell number, and aligned tissue structure, which were mitigated by fruquintinib/PD98059. PRP promoted VEGFR2 phosphorylation. PRP and fruquintinib/PD98059 abated p-VEGFR2/VEGFR2 or p-ERK1/2/ERK1/2 levels in DFU mice. PRP activated the ERK pathway through VEGFA/VEGFR2. Collectively, PRP promoted VEGFR2 phosphorylation and activated the ERK pathway, thereby facilitating wound repair in DFU mice.

Auxiliary effect of trolox on coenzyme Q10 restricts angiogenesis and proliferation of retinoblastoma cells via the ERK/Akt pathway

Reactive oxygen species (ROS) are essential for cancer signalling pathways and tumour maintenance, making ROS targeting a promising anti-cancer strategy. Coenzyme Q10 (CoQ10) has been shown to be effective against various cancers, but its impact on retinoblastoma, alone or with trolox, remains unreported. Cytotoxicity of CoQ10 alone and with trolox was evaluated in normal human retinal pigment epithelium cells (ARPE-19) and Y79 retinoblastoma cells using CCK-8. Flow cytometry was used to assess apoptosis, cell cycle, ROS, and mitochondrial membrane potential (MMP). Anti-angiogenic potential was tested using human umbilical vein endothelial cells (HUVECs) and chick chorioallantoic membrane (CAM) assays. Mechanistic studies were conducted via RT-PCR and western blotting. CoQ10, alone and with trolox, reduced Y79 cell viability, induced apoptosis through excess ROS generation, and decreased MMP significantly. Both treatments caused G2/M phase cell arrest. The CAM assay showed a significant reduction in endothelial cell proliferation, evidenced by fewer number of co-cultured HUVECs when exposed to CoQ10 or CoQ10 with trolox. The combination of CoQ10 and trolox significantly reduced VEGF-A, ERK, and Akt receptor levels, while CoQ10 alone significantly inhibited ERK and Akt phosphorylation. Together, CoQ10 and trolox reduced protein expression of VEGFA. CoQ10 alone and with trolox, induces apoptosis in Y79 retinoblastoma cells by inhibiting the ERK/Akt pathway and downregulating VEGFA. This study is the first to report the in vitro and in-ovo anti-cancer potential of CoQ10 alone or when combined with trolox, on human retinoblastoma Y79 cells.

Mineralocorticoid Receptor in Endothelial Cells Contributes to VEGF Receptor Inhibitor-Induced Vascular and Kidney Damage.

Vascular endothelial growth factor receptor inhibitors (VEGFRis) improve cancer patient survival by inhibiting tumor angiogenesis. However, VEGFRis induce treatment-limiting hypertension which has been associated with impaired vascular endothelial cell (EC) function and kidney damage. The mineralocorticoid receptor (MR) regulates blood pressure via effects on the vasculature and the kidney. Thus, we interrogated the role of the MR in EC dysfunction, renal impairment, and hypertension in a mouse model of VEGFRi-induced hypertension using sorafenib. EC dysfunction in mesenteric arterioles was assessed by immunoblotting for phosphorylation of endothelial nitric oxide synthase (eNOS) at serine 1177. Renal damage was measured by assessing glomerular endotheliosis histologically. Blood pressure (BP) was measured using implanted radiotelemetry. Six days of sorafenib treatment significantly impaired mesenteric resistance vessel EC function, induced renal damage, and increased BP. Pharmacologic MR blockade with spironolactone prevented the sorafenib-induced decline in eNOS phosphorylation and the renal glomerular endotheliosis, without affecting systolic or diastolic BP. Mice with the MR knocked out specifically in ECs (EC-MR-KO) were protected from sorafenib-induced EC dysfunction and glomerular endotheliosis, whereas smooth muscle cell-specific MR (SMC-MR) knockout mice were not. Neither EC-MR knockout nor SMC-MR knockout affected the degree to which sorafenib increased systolic or diastolic BP. These results reveal that the MR, specifically in EC but not in SMCs, is necessary for VEGFRi-induced renal and vascular injury. While ineffective at lowering SBP, these data suggest potential therapeutic benefits of MR antagonists, like spironolactone, to protect the vasculature and the kidneys from VEGFRi-induced injury.

Comprehensive analysis of VEGF/VEGFR inhibitor-induced immune-mediated hypertension: integrating pharmacovigilance, clinical data, and preclinical models.

This study aimed to elucidate the differential immunological mechanisms and characteristics of hypertension induced by VEGF inhibitors (VEGFi) and VEGF receptor inhibitors (VEGFRi), with the goal of optimizing monitoring strategies and treatment protocols. We investigated the risk of immune-related adverse events associated with VEGFi/VEGFRi-induced hypertension by analyzing the FDA Adverse Event Reporting System (FAERS) database. Findings were corroborated with blood pressure characteristics observed in clinical patients and preclinical models exposed to various VEGF/VEGFRi. Clinical and preclinical studies were conducted to compare immunological responses and hypertension profiles between inhibitor classes. An integrative analysis across cancer types and species was performed, focusing on key signaling pathways. Analysis of FAERS data, in conjunction with clinical observations, revealed that both VEGFi and VEGFRi significantly elevated the risk of immune-mediated, blood pressure-related adverse events (ROR=7.75, 95% CI: 7.76-7.95). Subsequent clinical and preclinical studies demonstrated differential immunological responses and hypertension profiles between inhibitor classes. VEGFRi exhibited a more rapid onset, greater blood pressure elevation, and higher incidence of immune-mediated adverse events compared to VEGFi (Systolic BP: ROR=0 for VEGFi vs. ROR=12.25, 95% CI: 6.54-22.96 for VEGFRi; Diastolic BP: ROR=5.09, 95% CI: 0.60-43.61 for VEGFi vs. ROR=12.90, 95% CI: 3.73-44.55 for VEGFRi). Integrative analysis across cancer types and species, focusing on key signaling pathways, revealed that VEGF/VEGFRi-induced blood pressure elevation was associated with immunomodulation of the mitogen activated protein kinase (MAPK) pathway (R=-0.379, P=0.0435), alterations in triglyceride metabolism (R=-0.664, P=0.0001), modulation of myo-inositol 1,4,5-trisphosphate-sensitive calcium release channel activity (R=0.389, P=0.0378), and dysregulation of nitric oxide eNOS activation and metabolism (R=-0.439, P=0.0179). The temporal dynamics of these effects demonstrated greater significance than dose-dependent responses. Both VEGFi and VEGFRi significantly augmented the risk of immune-mediated, blood pressure-related adverse events, with VEGFRi inducing a more rapid and pronounced onset of blood pressure elevation and a higher incidence of immune-related, blood pressure-associated adverse events compared to VEGFi.

New insights in the mechanisms of opioid analgesia and tolerance: Ultramicronized palmitoylethanolamide down-modulates vascular endothelial growth factor-A in the nervous system

Growing evidence suggests that opioid analgesics modulate angiogenesis during pathophysiological processes. Vascular endothelial growth factor-A (VEGF-A) was recently proposed to be involved in pain development. To date, no anti-angiogenic drug is used for pain management. When administered in a bioavailable formulation, (i.e., ultramicronized) N-palmitoylethanolamine (PEA) delays the onset of morphine tolerance, improves morphine analgesic activity and reduces angiogenesis in in vivo models. This study aimed at investigating whether VEGF-A is involved in PEA-induced delay of morphine tolerance. The anti-VEGF-A monoclonal antibody bevacizumab was used as a reference drug. Preemptive and concomitant treatment with ultramicronized PEA delayed morphine tolerance and potentiated the analgesic effect of morphine, while counteracting morphine-induced increase of VEGF-A in the nervous system. Similar results were obtained when bevacizumab was administered together with morphine. Of note, bevacizumab showed an analgesic effect per se. In equianalgesic treatment regimens (obtained through increasing morphine doses and associating PEA), PEA resulted in lower expression of VEGF-A in dorsal root ganglia (DRG) and spinal cord compared to morphine alone. Similar results were observed for plasma levels of the soluble VEGF receptor 1 (sFLT-1). Moreover, in morphine-treated animals, two pain-related genes (i.e., Serpina3n and Eaat2) showed a more than 3-fold increase in their expression at spinal cord and DRG level, with the increase being significantly counteracted by PEA treatment. This study supports the hypothesis that the effects of PEA on morphine analgesia and tolerance may be mediated by the down-modulation of VEGF-A and sFLT-1 in the nervous system and plasma, respectively.

Synthetic Antiangiogenic Vascular Endothelial Growth Factor-A Splice Variant Revascularizes Ischemic Muscle in Peripheral Artery Disease.

Alternative splicing in the eighth exon C-terminus of VEGF-A (vascular endothelial growth factor-A) results in the formation of proangiogenic VEGF165a and antiangiogenic VEGF165b isoforms. The only known difference between these 2 isoform families is a 6-amino acid switch from CDKPRR (in VEGF165a) to SLTRKD (in VEGF165b). We have recently shown that VEGF165b can induce VEGFR2-activation but fails to induce VEGFR1 (VEGF receptor 1)-activation. The molecular mechanisms that regulate VEGF165b's ability toward differential VEGFR2 versus VEGFR1 activation/inhibition are not yet clear. Hypoxia serum starvation was used as an invitro peripheral artery disease model. Unilateral single ligation of the femoral artery was used as a preclinical peripheral artery disease model. VEGFR1 activating ligands have 2 arginine (RR) residues in their eighth exon C-terminus, that were replaced by lysine-aspartic acid (KD) in VEGF165b. A synthetic anti-angiogenic VEGF165b splice variant in which the KD residues were switched to RR (VEGF165bKD→RR) activated both VEGFR1- and VEGFR2-signaling pathways to induce ischemic-endothelial cell angiogenic capacity invitro and enhance perfusion recovery in a severe experimental-peripheral artery disease model significantly higher than VEGF165a. Phosphoproteome arrays showed that the therapeutic efficacy of VEGF165bKD→RR over VEGF165a is due to its ability to induce P38-activation in ischemic endothelial cells. Our data shows that the KD residues regulate VEGF165b's VEGFR1 inhibitory property but not VEGFR2. Switching these KD residues to RR resulted in the formation of a synthetic/recombinant VEGF165bKD→RR isoform that has the ability to activate both VEGFR1- and VEGFR2-signaling and induce ischemic-endothelial cell angiogenic and proliferative capacity that matched the angiogenic requirement necessary to achieve perfusion recovery in a severe experimental-peripheral artery disease model.

Repeated treatment with VEGF receptor inhibitors induces phenotypic changes in endothelial cells and pericytes in the rat retina

Abnormal ocular angiogenesis is a major cause of visual impairment and vision loss in neovascularization-related diseases. Currently, anti-vascular endothelial growth factor (VEGF) drugs are used to treat ocular neovascularization, but repeated injections are needed to maintain their therapeutic effects. However, repeated injection of anti-VEGF drugs may affect the retinal blood vessel phenotype and diminish therapeutic effects. In this study, we aimed to investigate the phenotypic changes in endothelial cells and pericytes caused by the repeated interruption of the VEGF receptor signaling pathway in neonatal rats. KRN633 (10 mg/kg), a VEGF receptor tyrosine kinase inhibitor, was subcutaneously administered on postnatal day (P)-7 and P8 (first round), P14 and P15 (second round), and P21 and P22 (third round). The rat eyes were collected on P7, P9, P14, P16, P21, P23, P28, and P35. Using retinal flat-mount specimens stained with specific markers for vascular endothelial cells, basement membranes, and pericytes, the arteriolar tortuosity, capillary area density, and distribution of pericytes were evaluated. Significant loss of capillaries was observed the day after the first round of KRN633 treatment, after which aggressive angiogenesis occurred, leading to the formation of tortuous arterioles. Rats that completed second and third rounds of KRN633 treatment showed more severe abnormalities in the retinal vasculature than those that only completed first round treatment. Repeated treatment with KRN633 decreased the anti-angiogenic effects but increased the immunoreactivity of α-smooth muscle actin in the pericytes on veins and capillaries. α-Smooth muscle actin expression was inversely correlated to anti-angiogenic effects. Overall, these results revealed that repeated interruption of VEGF receptor signaling pathway altered the phenotypes of endothelial cells and pericytes and induced anti-VEGF drug resistance. Therefore, careful follow-up is necessary when using anti-VEGF drugs to treat abnormal angiogenesis-associated ocular diseases.

VEGF-dependent testicular vascularisation involves MEK1/2 signalling and the essential angiogenesis factors, SOX7 and SOX17

BackgroundAbnormalities of in utero testis development are strongly associated with reproductive health conditions, including male infertility and testis cancer. In mouse testes, SOX9 and FGF9 support Sertoli cell development, while VEGF signalling is essential for the establishment of vasculature. The mitogen-activated protein kinase (MAPK) pathway is a major signalling cascade, essential for cell proliferation, differentiation and activation of Sry during primary sex-determination, but little is known about its function during fetal testis morphogenesis. We explored potential functions of MAPK signalling immediately after the establishment of testis cords in embryonic day (E)12.5 Oct4-eGFP transgenic mouse testes cultured using a MEK1/2 inhibitor.ResultsRNA sequencing in isolated gonadal somatic cells identified 116 and 114 differentially expressed genes after 24 and 72 h of MEK1/2 inhibition, respectively. Ingenuity Pathway Analysis revealed an association of MEK1/2 signalling with biological functions such as angiogenesis, vasculogenesis and cell migration. This included a failure to upregulate the master transcriptional regulators of vascular development, Sox7 and Sox17, VEGF receptor genes, the cell adhesion factor gene Cd31 and a range of other endothelial cell markers such as Cdh5 (encoding VE-cadherin) and gap junction genes Gja4 and Gja5. In contrast, only a small number of Sertoli cell enriched genes were affected. Immunofluorescent analyses of control testes revealed that the MEK1/2 downstream target, ERK1/2 was phosphorylated in endothelial cells and Sertoli cells. Inhibition of MEK1/2 eliminated pERK1/2 in fetal testes, and CD31, VE-cadherin, SOX7 and SOX17 and endothelial cells were lost. Consistent with a role for VEGF in driving endothelial cell development in the testis, inhibition of VEGFR also abrogated pERK1/2 and SOX7 and SOX17 expressing endothelial cells. Moreover, while Sertoli cell proliferation and localisation to the testis cord basement membrane was disrupted by inhibition of MEK1/2, it was unaffected by VEGFR inhibition. Instead, inhibition of FGF signalling compromised Sertoli cell proliferation and localisation to the testis cord basement membrane.ConclusionsTogether, our data highlight an essential role for VEGF-dependent MEK1/2 signalling in promoting vasculature and indicate that FGF signalling through MEK1/2 regulates Sertoli cell organisation in the developing mouse testis.

Unveiling the antitumor synergy between pazopanib and metformin on lung cancer through suppressing p-Akt/ NF-κB/ STAT3/ PD-L1 signal pathway

Pazopanib, an inhibitor of the VEGF receptor tyrosine kinase, has demonstrated significant antitumor effects in lung cancer. However, its application as a standard treatment for this type of cancer is limited by its drug resistance and toxicity. Metformin has the potential to combat lung cancer by modifying the tumor’s immune microenvironment.In this study, we investigated the potential antitumor effects and the associated underlying molecular mechanisms of the combination of pazopanib and metformin in lung cancer. In vitro studies were conducted using the A549 and H460 lung cancer cell lines, whereas urethane-induced lung cancer-bearing mice were used for in vivo assessments. The urethane-induced mice received oral administration of pazopanib (50 mg/kg) and/or metformin (250 mg/kg) for a duration of 21 days.The results indicated that the MTT assay demonstrated a combined cytotoxic effect of the pazopanib/metformin combination in H460 and A549 cells, as evidenced by CI and DRI analyses. The observed increase in annexin V levels and the corresponding increase in Caspase-3 activity strongly suggest that this combination induced apoptosis.Furthermore, the pazopanib/metformin combination significantly inhibited the p-Akt/NF-κB/IL-6/STAT3, HIF1α/VEGF, and TLR2/TGF-β/PD-L1 pathways while also increasing CD8 expression in vivo. Immunohistochemical analysis revealed that these antitumor mechanisms were manifested by the suppression of the proliferation marker Ki67. In conclusion, these findings revealed that metformin augments the antitumor efficacy of pazopanib in lung cancer by simultaneously targeting proliferative, angiogenic, and immunogenic signaling pathways, metformin enhances the antitumor effectiveness of pazopanib in lung cancer, making it a promising therapeutic option for lung cancer.

Fucoxanthin Attenuates Angiogenesis by Blocking the VEGFR2-Mediated Signaling Pathway through Binding the Vascular Endothelial Growth Factor.

Fucoxanthin, a dietary carotenoid, is predominantly found in edible brown algae and is commonly consumed worldwide. Fucoxanthin has been shown to possess beneficial health activities such as antidiabetic, anti-inflammatory, antimutagenic, and antiobesity; however, the effects of fucoxanthin on VEGF-mediated angiogenesis and its possible binding with VEGF are unknown. Here, different lines of evidence supported the suppressive roles of fucoxanthin in VEGF-mediated angiogenesis. In human umbilical vein endothelial cells, fucoxanthin remarkedly suppressed VEGF-mediated cell proliferative, migration, and invasive abilities, as well as tube formation, without cytotoxicity. In addition, fucoxanthin inhibited the subintestinal vessel formation of zebrafish in vivo. In signaling cascades, fucoxanthin was proposed to interact with VEGF, thus attenuating VEGF's functions in activating the VEGF receptor and its related downstream signaling, i.e., phosphorylations of MEK and Erk. Fucoxanthin also significantly blocked VEGF-triggered ROS formation. Furthermore, the outcomes of applying fucoxanthin in cancer cells were identified, which included (i) inhibiting VEGF-mediated cell proliferation and migration and (ii) inhibiting NF-κB translocation via limiting MMP2 expression. These lines of investigations supported the antiangiogenic roles of fucoxanthin, as well as reviewing its signaling mechanisms, in blocking the VEGF-triggered responses. The results would benefit the potential development of fucoxanthin for the prevention and treatment of angiogenesis-related diseases.

Mapping the cellular expression patterns of vascular endothelial growth factor aa and bb genes and their receptors in the adult zebrafish brain during constitutive and regenerative neurogenesis

The complex interplay between vascular signaling and neurogenesis in the adult brain remains a subject of intense research. By exploiting the unique advantages of the zebrafish model, in particular the persistent activity of neural stem cells (NSCs) and the remarkable ability to repair brain lesions, we investigated the links between NSCs and cerebral blood vessels. In this study, we first examined the gene expression profiles of vascular endothelial growth factors aa and bb (vegfaa and vegfbb), under physiological and regenerative conditions. Employing fluorescence in situ hybridization combined with immunostaining and histology techniques, we demonstrated the widespread expression of vegfaa and vegfbb across the brain, and showed their presence in neurons, microglia/immune cells, endothelial cells and NSCs. At 1 day post-lesion (dpl), both vegfaa and vegfbb were up-regulated in neurons and microglia/peripheral immune cells (macrophages). Analysis of vegf receptors (vegfr) revealed high expression throughout the brain under homeostatic conditions, with vegfr predominantly expressed in neurons and NSCs and to a lower extent in microglia/immune cells and endothelial cells. These findings were further validated by Vegfr3 and Vegfr4 immunostainings, which showed significant expression in neurogenic radial glial cells.Following brain lesion (1 dpl), while vegfr gene expression remained stable, vegfr transcripts were detected in proliferative cells within the injured parenchyma. Collectively, our results provide a first overview of Vegf/Vegfr signaling in the brain and suggest important roles for Vegf in neurogenesis and regenerative processes.

R-954, a bradykinin B1 receptor antagonist, as a potential therapy in a preclinical endometriosis model

Endometriosis is a gynecological condition characterized by the growth of endometrium-like tissues outside of the uterine cavity. Currently available drugs are efficacious in treating endometriosis-related pain, however it’s not a targeted treatment. The aim of this work is to evaluate the effects of R-954, a bradykinin B1 receptor antagonist, in a murine model of endometriosis. The model was induced in animals through autologous transplantation of part of the uterine horn. After 51 days, it was observed that implants developed into endometriotic lesions. The administration of R-954 or progesterone, for 15 consecutive days, prevented the progression of cyst development, reduced the size and weight of the cysts. Both treatments also reduced cellular infiltrate and production of inflammatory mediators (interleukin-1β, interleukin-6, tumor necrosis factor). However, only R-954 decreased angiogenic factors (VEGF and VEGF receptor). In addition, treatment with the antagonist did not interfere in the females’ estrous cycle, as well as prevented gestational losses (reduction in the number of intermediate resorptions in pregnant females with endometriosis). Data suggested that R-954 has anti-inflammatory and anti-angiogenic effects; does not influence the estrous cycle; and prevents the number of gestational losses suggesting it as a good candidate for endometriosis treatment.

Buyang Huanwu decoction promotes angiogenesis and improves hemorheological parameters after cervical spinal cord injury

ObjectiveTo explore the effects of Buyang Huanwu decoction (BYHWD) on vascular neogenesis and hemorheological parameters following cervical spinal cord injury (SCI). MethodsAn acute cervical SCI model was established using 84 female Sprague–Dawley rats. Functional recovery of the rats was evaluated using the forelimb locomotor scale score, forelimb grip strength test, and Basso-Beattie-Bresnahan score. The animals were subsequently euthanized at days 7 and 28 postoperatively. The gross morphology, neuronal survival, and myelin sheath in the injured area were evaluated using hematoxylin and eosin (HE), Nissl, and luxol fast blue (LFB) staining, respectively. Immunofluorescence staining was used to observe CD31 expression 7 days post-injury. Furthermore, the expression of CD31, neuronal nuclear protein (NeuN), and myelin basic protein (MBP) were evaluated 28 days post-injury. Additionally, vascular endothelial growth factor A (VEGFA) and VEGF receptor-2 (VEGFR-2) expression was evaluated using western blotting. Whole-blood viscosity, plasma viscosity, and red blood cell aggregation were measured using a hemorheometer. ResultsFrom postoperative days 3–28, motor function in the BYHWD group began to recover considerably compared to the SCI group. BYHWD effectively restored spinal cord histopathology. In addition, the number of NeuN-positive cells, and fluorescence intensity of CD31at 7 and 28 days and MBP significantly increased in the BYHWD group compared with the SCI group (all P < 0.05). Moreover, this decoction significantly upregulated the expression of VEGFA and VEGFR-2 (all P < 0.05). BYHWD improved the hemorheology results (i.e., except erythrocyte aggregation index in the low-dose group), revealing statistically significant differences compared with the SCI group (all P < 0.05). ConclusionBYHWD effectively promoted angiogenesis, improved hemorheological parameters, and protected neurons and myelin sheaths, ultimately promoting the recovery of neurological function after cervical SCI in rats. These findings suggest that BYHWD promotes vascular neogenesis through the VEGFA/VEGFR-2 pathway.

VEGF-A165a and angiopoietin-2 differently affect the barrier formed by retinal endothelial cells

Exposure to VEGF-A165a over several days leads to a persistent dysfunction of the very tight barrier formed by immortalized endothelial cells of the bovine retina (iBREC). Elevated permeability of the barrier is indicated by low cell index values determined by electric cell-substrate impedance measurements, by lower amounts of claudin-1, and by disruption of the homogenous and continuous staining of vascular endothelial cadherin at the plasma membrane. Because of findings that suggest modulation of VEGF-A's detrimental effects on the inner blood-retina barrier by the angiogenic growth factor angiopoietin-2, we investigated in more detail in vitro whether this growth factor indeed changes the stability of the barrier formed by retinal endothelial cells or modulates effects of VEGF-A. In view of the clinical relevance of anti-VEGF therapy, we also studied whether blocking VEGF-A-driven signaling is sufficient to prevent barrier dysfunction induced by a combination of both growth factors. Although angiopoietin-2 stimulated proliferation of iBREC, the formed barrier was not weakened at a concentration of 3 nM: Cell index values remained high and expression or subcellular localization of claudin-1 and vascular endothelial cadherin, respectively, were not affected. Angiopoietin-2 enhanced the changes induced by VEGF-A165a and this was more pronounced at lower concentrations of VEGF-A165a. Specific inhibition of the VEGF receptors with tivozanib as well as interfering with binding of VEGF-A to its receptors with bevacizumab prevented the detrimental effects of the growth factors; dual binding of angiopoietin-2 and VEGF-A by faricimab was marginally more efficient. Uptake of extracellular angiopoietin-2 by iBREC can be efficiently prevented by addition of faricimab which is also internalized by the cells. Exposure of the cells to faricimab over several days stabilized their barrier, confirming that inhibition of VEGF-A signaling is not harmful to this cell type. Taken together, our results confirm the dominant role of VEGF-A165a in processes resulting in increased permeability of retinal endothelial cells in which angiopoietin-2 might play a minor modulating role.

Efficacy of chemotherapy containing bevacizumab in patients with metastatic colorectal cancer according to programmed cell death ligand 1.

Bevacizumab, an anti-vascular endothelial growth factor (VEGF) monoclonal antibody, inhibits angiogenesis and reduces tumor growth. Serum VEGF-C, lactate dehydrogenase, and inflammatory markers have been reported as predictive markers related to bevacizumab treatment. Programmed cell death ligand 1 (PD-L1) could act upon VEGF receptor 2 to induce cancer cell angiogenesis and metastasis. To investigate the efficacy of bevacizumab-containing chemotherapy in patients with metastatic colorectal cancer (CRC) according to the expression of PD-L1. This analysis included CRC patients who received bevacizumab plus FOLFOX or FOLFIRI as first-line therapy between June 24, 2014 and February 28, 2022, at Samsung Medical Center (Seoul, South Korea). Analysis of patient data included evaluation of PD-L1 expression by the combined positive score (CPS). We analyzed the efficacy of bevacizumab according to PD-L1 expression status in patients with CRC. A total of 124 patients was included in this analysis. Almost all patients were treated with bevacizumab plus FOLFIRI or FOLFOX as the first-line chemotherapy. While 77% of patients received FOLFOX, 23% received FOLFIRI as backbone first-line chemotherapy. The numbers of patients with a PD-L1 CPS of 1 or more, 5 or more, or 10 or more were 105 (85%), 64 (52%), and 32 (26%), respectively. The results showed no significant difference in progression-free survival (PFS) and overall survival (OS) with bevacizumab treatment between patients with PD-L1 CPS less than 1 and those with PD-L1 CPS of 1 or more (PD-L1 < 1% vs PD-L1 ≥ 1%; PFS: P = 0.93, OS: P = 0.33), between patients with PD-L1 CPS less than 5 and of 5 or more (PD-L1 < 5% vs PD-L1 ≥ 5%; PFS: P = 0.409, OS: P = 0.746), and between patients with PD-L1 CPS less than 10 and of 10 or more (PD-L1 < 10% vs PD-L1 ≥ 10%; PFS: P = 0.529, OS: P = 0.568). Chemotherapy containing bevacizumab can be considered as first-line therapy in metastatic CRC irrespective of PD-L1 expression.

Advanced Renal Cell Cancer Combination Immunotherapy Clinical Trial (ARCITECT; HCRN GU 22-587)

Abstract Background First-line treatment for patients with metastatic clear cell renal cell carcinoma (mccRCC) often includes an anti-PD1 inhibitor in combination with either an anti-CTLA inhibitor (IO/IO) or a VEGF receptor tyrosine kinase inhibitor (TKI) (IO/TKI). Although some patients treated with nivolumab/ipilimumab (Nivo/Ipi) (IO/IO) experience durable responses leading to treatment free intervals, over two-thirds experience disease progression. Resistance to Nivo (anti-PD1) monotherapy has been associated with increased presence of a subpopulation of Tregs in the tumor microenvironment. Botensilimab (Bot) is an IO agent that leverages novel FcyR-associated mechanisms of action to enhance T cell priming, deplete intratumoral Tregs and enhance myeloid activation. Combination botensilimab/balstilimab (Bot/Bal) (anti-CTLA/anti-PD1) has shown impressive anti-tumor activity in diseases where Nivo/Ipi has shown little to no efficacy. Methods ARCITECT is a phase II, multicenter study evaluating the efficacy and safety of Bot/Bal relative to Nivo/Ipi. Patients with mccRCC (favorable, intermediate, or poor risk), no prior systemic therapy (including adjuvant or neoadjuvant), and at least one measurable lesion as defined by RECIST 1.1 are eligible for enrollment. 120 patients will be randomized in a 2:1 fashion to Arm A (Bot/Bal induction followed by Bal maintenance) or Arm B (Nivo/Ipi induction followed by Nivo maintenance) each for a maximum of 2 years. Stratification factors include IMDC risk groups and sarcomatoid histology. The primary endpoint is overall response rate (ORR) per RECIST 1.1. We hypothesize that Bot/Bal will lead to a superior ORR (55%) relative to Nivo/Ipi (40%). This trial has &amp;gt; 90% power to detect the alternative hypothesis while maintaining a one-sided significance level of not more than 0.10 using the exact binomial. The study will be monitored for early stopping in favor of the null hypothesis based on a Simon’s two stage design. In the first stage, 69 patients will be enrolled (Arm A:46 and Arm B:23). If at the end of the first stage, Arm A has either at least 18/42 (42.8%) of eligible patients responding or an ORR at least numerically equivalent to that for eligible patients in Arm B, then the trial will progress to the second stage. The primary endpoint will be met if there are 38/80 responders (ORR &amp;gt; 47.5%) in Arm A. Key secondary endpoints include landmark progression-free survival, treatment-free survival and rates of immune-related adverse events. Correlative studies will explore immune and molecular predictors of response and resistance to IO/IO in tumor and blood. Clinical trial information: NCT05928806. Results

In-silico screening of bioactive compounds of Moringa oleifera as potential inhibitors targeting HIF-1α/VEGF/GLUT-1 pathway against Breast Cancer.

Breast cancer is among the most heterogeneous and aggressive diseases and a foremost cause of death in women globally. Hypoxic activation of HIF-1α in breast cancers triggers the transcription of a battery of genes encoding proteins that facilitate tumor growth and metastasis and is correlated with a poor prognosis. Based on the reported cytotoxic and anti-cancer properties of Moringa oleifera (Mo), this study explores the inhibitory effect of bioactive compounds from M.oleifera and breast cancer target proteins HIF-1α, VEGF, and GLUT-1 in silico. The X-ray crystallographic structures of HIF-1α, VEGF, and GLUT1 were sourced from the Protein Data Bank(PDB) and docked with 70 3D PubChem structures of bioactive compounds of M.oleifera using AutoDock Vina, and binding modes were analyzed using Discovery Studio. Five compounds with the highest binding energies were selected and further drug-likeness, oral bioavailability, ADME, and toxicity profiles were analyzed using SwissADME, ADMETSaR, and ADMETlab 3.0 web server. Out of the screened 70 bioactive compounds, the top five compounds with the best binding energies were identified namely Apigenin, Ellagic Acid, Isorhamnetin, Luteolin, and Myricetin with each receptor. Molecular docking results indicated that the ligands interact strongly with the target HIF-1α, VEGF, and GLUT-1 receptors through hydrogen bonds and hydrophobic interactions. These compounds showed favorable drug-like and pharmacokinetic properties, possessed no substantial toxicity, and were fairly bioavailable. Results suggested that the compounds possess strong potential in developing putative lead compounds targeting HIF-1α that are safe natural plant-based drugs against breast cancer.

Phase I/II Study of a Vascular Endothelial Growth Factor Receptor Vaccine in Patients With NF2-Related Schwannomatosis.

The humanized antivascular endothelial growth factor (VEGF) antibody bevacizumab (Bev) is efficacious for the treatment of NF2-related schwannomatosis (NF2), previously known as neurofibromatosis type 2. This study evaluated the safety and efficacy of a VEGF receptor (VEGFR) vaccine containing VEGFR1 and VEGFR2 peptides in patients with NF2 with progressive schwannomas (jRCTs031180184). VEGFR1 and VEGFR2 peptides were injected subcutaneously into infra-axillary and inguinal regions, once a week for 4 weeks and then once a month for 4 months. The primary end point was safety. Secondary end points included tolerability, hearing response, imaging response, and immunologic response. Sixteen patients with NF2 with progressive schwannomas completed treatment and were assessed. No severe vaccine-related adverse events occurred. Among the 13 patients with assessable hearing, word recognition score improved in five patients at 6 months and two at 12 months. Progression of average hearing level of pure tone was 0.168 dB/mo during the year of treatment period, whereas long-term progression was 0.364 dB/mo. Among all 16 patients, a partial response was observed in more than one schwannoma in four (including one in which Bev had not been effective), minor response in 5, and stable disease in 4. Both VEGFR1-specific and VEGFR2-specific cytotoxic T lymphocytes (CTLs) were induced in 11 patients. Two years after vaccination, a radiologic response was achieved in nine of 20 assessable schwannomas. This study demonstrated the safety and preliminary efficacy of VEGFR peptide vaccination in patients with NF2. Memory-induced CTLs after VEGFR vaccination may persistently suppress tumor progression.

Analyzing VEGFA/VEGFR1 Interaction: Application of the Resonant Recognition Model-Stockwell Transform Method to Explore Potential Therapeutics for Angiogenesis-Related Diseases.

The interaction between vascular endothelial growth factor A (VEGFA) and VEGF receptor 1(VEGFR1) is a central focus for drug development in pathological angiogenesis, where aberrant angiogenesis underlies various anomalies necessitating therapeutic intervention. Identifying hotspots of these proteins is crucial for developing new therapeutics. Although machine learning techniques have succeeded significantly in prediction tasks, they struggle to pinpoint hotspots linked to angiogenic activity accurately. This study involves the collection of diverse VEGFA and VEGFR1 protein sequences from various species via the UniProt database. Electron-ion interaction Potential (EIIP) values were assigned to individual amino acids and transformed into frequency-domain representations using discrete Fast Fourier Transform (FFT). A consensus spectrum emerged by consolidating FFT data from multiple sequences, unveiling specific characteristic frequencies. Subsequently, the Stockwell Transform (ST) was employed to yield the hotspots. The Resonant Recognition Model (RRM) identified a characteristic frequency of 0.128007 with an associated wavelength of 1570nm and RRM-ST identified hotspots for VEGFA (Human 36, 46, 48, 67, 71, 74, 82, 86, 89, 93) and VEGFR1 (Human 224, 259, 263, 290, 807, 841, 877, 881, 885, 892, 894, 909, 913, 1018, 1022, 1026, 1043). These findings were cross-validated by Hotspots Wizard 3.0 webserver and Protein Data Bank (PDB). The study proposes using a 1570nm wavelength for photo bio modulation to boost VEGFA/VEGFR1 interaction in the condition that is needed. It also aims to reduce VEGFA/VEGFR2 interaction, limiting harmful angiogenesis in conditions like diabetic retinopathy. Also, the identified hotspots assist in designing agonistic or antagonistic peptides tailored to specific medical requirements with abnormal angiogenesis.

Clinical course and vascular endothelial growth factor signaling system expression in maxillary angiosarcoma: A case report.

Maxillary angiosarcoma, an aggressive tumor derived from vascular endothelial cells, is very rare. Recently, antivascular endothelial growth factor (VEGF) therapies have attracted considerable attention. We describe the clinical course of a patient with maxillary angiosarcoma and discuss the expression of VEGF signaling molecules assessed via immunohistological analysis. An 81-year-old man presented with an aggressive tumor in the left maxillary sinus. Biopsy revealed atypical nuclear cell proliferation, and the tumor was suspected to be a sarcoma. The maxillary malignancy was treated using a multidisciplinary approach with a combination of surgery, radiotherapy, and regional chemotherapy. Examination of the specimen obtained in the first surgery revealed maxillary angiosarcoma, found to be positive for CD31, while negative for CD34, D2-40, and factor Ⅷ. Although no pathological residual tumor was observed after the planned wide surgery, cervical lymph node and distant metastases occurred. The patient died 24 months after the first surgery. Staining revealed VEGF receptor (VEGFR) 1, VEGFR2, phosphorylated Ak strain transforming, mitogen-activated protein kinase, and signal transducer and activator of transcription 3 positivity. Although our findings do not indicate that anti-VEGF therapy is beneficial for treating maxillary angiosarcomas, we found that VEGFR signaling pathways were activated in maxillary angiosarcomas similar to angiosarcomas originating at other sites. Herein, we report a case of maxillary angiosarcoma, focused on VEGFR and signaling pathway activation. To our knowledge, this is the first report to describe VEGFR system immunostaining findings in maxillary angiosarcoma.