Vascular Endothelial Growth Factor Angiogenesis Research Articles

Сlinical and neuroimmunological correlations in post-stroke epilepsy illustrated by analyzing serum neuron-specific enolase and vascular endothelial growth factor

Background. Due to progress in the treatment of patients who have suffered a stroke, the prevalence of post-stroke epilepsy (PSE) has been increasing. The search for biomarkers that determine the prognosis of ischemic stroke (IS) complications and PSE development along with creating a diagnostic protocol subsequently is useful for advancing tactics of PSE therapy.Objective: to investigate the blood serum levels of neuron-specific enolase (NSE) and vascular endothelial growth factor (VEGF) in PSE patients paralleled by assessing clinical and neuroimmunological correlations.Material and methods. A total of 140 patients aged 28 to 84 years with the first IS was examined. Of these, 70 patients newly developed late epileptic seizures (main group), 70 patients had IS without epileptic seizures (comparison group). The control group consisted of 30 patients without IS or epilepsy. IS severity was assessed according to the National Institutes of Health Stroke Scale (NIHSS), the degree of disability – according to the modified Rankin Scale (mRS), the level of patient’s basic functional activity – according to the Barthel Index (BI). Prediction of post-IS onset of late seizures was performed according to the SeLECT scale (SEverity of stroke, Large artery atherosclerosis, Early seizure, Cortical involvement, Territory of the middle cerebral artery). To assess severity of epilepsy, the K. Lühdorf et al. classification was used. The levels of NSE neurotrophic factor and VEGF angiogenesis factor were measured in blood serum samples from all patients by using enzyme-linked immunosorbent assay (ELISA).Results. A significantly increased NSE and VEGF levels were noted in main group (by 4.72- and 1.59-fold, respectively) and in comparison group (by 4.45- and 1.54-fold, respectively) compared to control group. In addition, NSE and VEGF levels in main group significantly exceeded those in comparison group (by 1.06- and 1.03-fold, respectively). Both biomarkers also tended to increase in patients with moderate and severe PSE. The level of NSE/VEGF correlation characterizing damage to the nervous tissue and angiogenesis as well as degree of severity, disability, rehabilitation potential, patients’ everyday life activity, NSE and VEGF prognostic significance in development and severity level of epilepsy in IS patients with epileptic seizures was determined.Conclusion. NSE and VEGF hyperexpression is important in predicting development or progression (worsening) of epilepsy after IS.

The potential role of Ral-interacting protein 76 and vascular endothelial growth factor on angiogenesis in the tumor and ovarian corpus luteum microenvironment.

Tumors and the ovarian corpus luteum have complex mechanisms in the growth microenvironment. Angiogenesis is especially important for demonstrating the molecular mechanism of dynamic cellular function in tumors and corpus luteum. Angiogenesis in tumors and corpus luteum seems to have a similar function, and Ral-interacting protein 76 (RLIP76) and vascular endothelial growth factor (VEGF) are expressed in the tissues of tumors and ovarian corpus luteum. RLIP76 is a potential factor with VEGF in the tumor and corpus luteum angiogenesis. RLIP76 regulates a small GTPase (R-Ras) in cell survival, spreading, and migration. VEGF activates angiogenic functions in tumor and endothelial cells. Hypoxia-inducible factor-1 (HIF-1) is important in tumor growth, tumor angiogenesis, and corpus luteum. VEGF and HIF-1 regulate the angiogenic function of RLIP76, and RLIP76 controls vascular growth in endothelial and tumor cells. RLIP76, R-Ras, VEGF, and HIF-1 may be useful in the research of corpus luteum and cancer therapy and the study of mechanisms of tumor and corpus luteum angiogenesis. This review will help to elucidate the roles of RLIP76 and VEGF in tumor and corpus luteum angiogenesis, tumorigenesis, and the specific regulation of RLIP76 and VEGF. Thus, we reviewed the potential role of RLIP76 and VEGF in the angiogenesis of the tumor and corpus luteum in the tumor and ovarian microenvironment.

Vascular Endothelial Growth Factor (VEGF) and Its Role in the Progression and Development of Breast Tumor

Breast cancer is the most common type of cancer in women and is widely known. Angiogenesis is the process through which new blood vessels develop from the body's current vascular system. It is essential for tumor growth, invasiveness, and metastasis, and so plays a pivotal role in the development of carcinoma. Proteolytic and proangiogenic catalyst activators and inhibitors regulate angiogenesis in a hierarchical fashion. The angiogenic process is largely under the direction of VEGF. In a select number of malignant tumors, the VEGF gene is overexpressed. The function of VEGF in angiogenesis has been the subject of intensive study in recent years. In breast cancer patients, VEGF plasma levels are highly predictive of tumor growth and survival. Several VEGF gene polymorphisms, have been identified to affect gene expression level in prior investigations. Epidemiological studies have linked polymorphisms in the VEGF gene to altered cancer risk, tumor growth, and metastasis. Previous research on VEGF polymorphism to evaluate the association between genes and breast cancer susceptibility was scant. The current review discusses the role of VEGF in the progression of breast cancer in addition to its promising usage as a predictive marker for breast cancer.

Dominant negative biologics normalise the tumour necrosis factor (TNF-α) induced angiogenesis which exploits the Mycobacterium tuberculosis dissemination

BackgroundTumor necrosis factor (TNF) is known to promote T cell migration and increase the expression of vascular endothelial growth factor (VEGF) and chemokines. The administration of Xpro-1595, a dominant-negative TNF (DN-TNF) engineered to selectively inactivate soluble TNF (solTNF), has been extensively studied and proven effective in reducing TNF production without suppressing innate immunity during infection. The literature also supports the involvement of glutamic acid-leucine-arginine (ELR+) chemokines and VEGF in angiogenesis and the spread of infections.Materials and methodsIn this study, we administered Xpro-1595 to guinea pigs to selectively inhibit solTNF, aiming to assess its impact on Mycobacterium tuberculosis (M.tb) dissemination, bacterial growth attenuation, and immunological responses. We conducted immunohistochemical analyses, immunological assays, and colony enumeration to comprehensively study the effects of Xpro-1595 by comparing with anti-TB drugs treated M.tb infected guinea pigs. Throughout the infection and treatment period, we measured the levels of Interleukin-12 subunit alpha (IL-12), Interferon-gamma (IFN-γ), TNF, Tumor growth factor (TGF), and T lymphocytes using ELISA.ResultsOur findings revealed a reduction in M.tb dissemination and inflammation without compromising the immune response during Xpro-1595 treatment. Notably, Xpro-1595 therapy effectively regulated the expression of VEGFA and ELR + chemokines, which emerged as key factors contributing to infection dissemination. Furthermore, this treatment influenced the migration of CD4 T cells in the early stages of infection, subsequently leading to a reduced T cell response and controlled proinflammatory signalling, thus mitigating inflammation.ConclusionOur study underscores the pivotal role of solTNF in the dissemination of M.tb to other organs. This preliminary investigation sheds light on the involvement of solTNF in the mechanisms underlying M.tb dissemination, although further in-depth research is warranted to fully elucidate its role in this process.

The role of molecular mechanism of Ten-Eleven Translocation2 (TET2) family proteins in pathogenesis of cardiovascular diseases (CVDs).

Cardiovascular disease (CVD) is one of the most common diseases worldwide. The underlying pathogenesis of the disease has not yet been determined, but many factors have been identified. Tet methylcytosine dioxygenase 2 (TET2) is one of the epigenetic factors involved in regulating many genes. Therefore, based on the studies shown, this factor plays an important role in preventing the occurrence of CVD. TET2 has been shown to increase angiogenesis by expressing Robo4. It also increases the activity of Matrix metalloproteinases (MMPs) and stimulates the secretion of Vascular endothelial growth factor angiogenesis. On the other hand, it has been shown that TET2 regulates the expression of several genes and the development of the heart during the embryonic period due to its oxygenating role. TET2 has been shown to regulates the expression of the genes such as Ying Yang1 (YY1), Sox9b, Inhbaa and many other genes that ultimately lead to the differentiation of cardiomyocytes. On the other hand, it has been shown that some Long non coding RNA and MicroRNAs reduce TET2 expression and CVD. Finally, it is concluded that inducing TET2 expression can be a good therapeutic strategy to prevent or improve CVD.

The critical role of the interplays of EphrinB2/EphB4 and VEGF in the induction of angiogenesis.

The significant role of VEGF (vascular endothelial growth factor) as an angiogenesis inducer is well recognized. Besides VEGF, EphrinB2/EphB4 also plays essential roles in vascular development and postnatal angiogenesis. Compared with classical proangiogenic factors, not only does EphrinB2/EphB4 promote sprouting of new vessels, it is also involved in the vessel maturation. Given their involvement in many physiologic and pathological conditions, EphB4 and EphrinB2 are increasingly recognized as attractive therapeutic targets for angiogenesis-related diseases through modulating their expression and function. Previous works mainly focused on the individual role of VEGF and EphrinB2/EphB4 in angiogenesis, respectively, but the correlation between EphrinB2/EphB4 and VEGF in angiogenesis has not been fully disclosed. Here, we summarize the structure and bidirectional signaling of EphrinB2/EphB4, provide an overview on the relationship between EphrinB2/EphB4 signaling and VEGF pathway in angiogenesis and highlight the associated potential usefulness in anti-angiogenetic therapy.

The Antiangiogenesis Role of Histone Deacetylase Inhibitors: Their Potential Application to Tumor Therapy and Tissue Repair.

Angiogenesis, a process of new blood vessel formation from existing blood vessels, plays an important role in tumor growth and the tissue repair process. It is generally acknowledged that angiogenesis might contribute two both processes. In tumor growth, angiogenesis often increases oncogenic signaling, and in tissue repair, it decreases the stiffness of wound tissue and potentially exacerbates scar formation, resulting in pain and poor function. These poor outcomes are due to an increase in the expression of important genes involved in angiogenesis, such as hypoxia-inducible factor-1 alpha (HIF-1α) and its transcriptional target vascular endothelial growth factor (VEGF). Therefore, this adverse effect of angiogenesis should be taken into consideration. Limiting vessel growth instead of boosting growth may be beneficial for favorable long-term healing outcomes. Posttranslational modifications, including acetylation, which is mediated by histone acetyltransferases, and deacetylation, which is mediated by histone deacetylases (HDACs), are critical to HIF-1α function. Most studies have indicated that HDAC inhibitors (HDACIs) show great promise as antiangiogenic agents in the early phase of clinical trials. In this review, we discuss the role of the HDACs HIF-1α and VEGF in angiogenesis. Furthermore, we also discuss the molecular and cellular underpinnings of the effects of HDACIs on antiangiogenesis, which creates new avenues for anticancer therapeutics and the repair of wounded tissue.

Simultaneous interference of SP1 and HIF1α retarding the proliferation, migration, and invasion of human microvascular endothelial cells (HMEC-1) under hypoxia.

To investigate the regulation of special protein 1 (SP1) and hypoxia-inducible factor-1α (HIF1α) on human microvascular endothelial cells (HMEC-1) under hypoxic conditions. The expression of SP1 and HIF1α under normoxia and hypoxic conditions were assessed by Western blot. SP1 and HIF1α were knocked down by small interfering RNA (siRNA) under hypoxic conditions. The proliferation, migration, and invasion of HMEC-1 were measured by cell counting kit 8, 5-ethynyl-2'-deoxyuridine and Transwell coculture system. Western blot analysis and Immunofluorescence were carried out to study the mechanisms of simultaneously inhibiting the adenosine triphosphatase (CD39), 5'-nucleotidase (CD73), adenosine, and vascular endothelial growth factor (VEGF). We compared the inhibitory effects between groups concurrently interfering SP1, HIF-1α, and ranibizumab under hypoxic conditions. Under hypoxic conditions, the protein expression of SP1 and HIF1α was increased in HMEC-1, contrarily, SP1 siRNA and HIF1α siRNA downregulated the expression. Simultaneous inhibition of SP1 and HIF1α demonstrated a much greater restraint of proliferation, migration, and invasion characteristics on HMEC-1 than respectively knocking down SP1 or HIF1α and anti-VEGF drugs (0.5 mg/mL ranibizumab) (siRNA and the VEGF inhibitor were applied separately in different groups). Meanwhile, simultaneous inhibition of SP1 and HIF1α effectively reduced the expression of CD39, CD73, adenosine, and VEGF on HMEC-1 under hypoxic conditions. Our study demonstrated that both SP1 and HIF1α played important roles in HMEC-1 under hypoxia condition. Simultaneous inhibition of SP1 and HIF1α effectively decreased the activity of HMEC-1 under hypoxic conditions through the CD39-CD73-adenosine and VEGF angiogenesis pathways. Our study may provide a new approach to the treatment of retinal neovascular diseases.

Obesity impairs ADAM17‐mediated vascularization of pericardial adipose tissue in patients with coronary artery disease

Expansion of pericardial adipose tissue (pAT) correlates with the severity of coronary artery disease in obese patients. Dysfunctional pAT is a significant source of pro‐inflammatory cytokine and adipokine production, but mechanisms that underlie pAT dysfunction remain poorly understood. During angiogenesis vascular endothelial growth factor (VEGF) activates A disintegrin and metalloproteinase ADAM17 that induce Notch ectodomain shedding to promote new vessel growth. We hypothesized that ADAM17‐mediated vascularization of expanded pAT is disproportional in obese patients. We obtained pAT from patients undergoing coronary artery bypass surgery (N=38, BMI, 17–43) and found that BMI was positively correlated with adipocyte size and increased collagen deposition in pAT. A higher BMI was associated with lower ADAM17 activity in pAT microvessels, which was associated with significantly reduced microvessel density and reduced capillary to adipocyte ratio in obese patients. In a three‐dimensional angiogenesis assay we determined VEGF‐stimulated growing of endothelial sprouts from pAT artery rings. We found that the number of endothelial sprouts is significantly reduced in obese patients when compared to that of pAT arteries from non‐obese subjects. We also found that genetic silencing of ADAM17 significantly reduced VEGF‐induced endothelial sprouting. Thus, we concluded that reduced ADAM17 activation results in impaired vascularization and hence dysfunctional pAT in obese patients with coronary artery disease.Support or Funding InformationAmerican Heart Association 17GRNT33680171, NIH F31 HL142183‐01 and NIH R01AG054651This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Biochemical Investigation of Tissue Oxidative Stress and Angiogenesis with Associated Trace Elements in Breast Disease Patients in Uttarakhand, India.

Breast cancer is a heterogeneous cancer with diverse clinical symptoms and an ambiguous molecular spectrum. Oxidative damage, antioxidant activity, and angiogenesis combine to form significant complex factors that stimulate breast cancer development and progression. This study is designed to determine level changes in total antioxidant status and markers of lipid peroxidation melondialdehyde (MDA) and angiogenesis vascular endothelial growth factor (VEGF) along with related micronutrients of copper, zinc, magnesium, and iron in malignant and benign breast disease tissue extracts. We assess specificity and sensitivity of those markers using the area under the curve of receiver operator characteristic (ROC) curve analysis. Association studies are done with correlation analysis. The tissue extract level of MDA markers is found to be significantly higher (14.118 ± 1.47 nmol/g tissue; p < 0.05), with significantly depleted levels of antioxidants (5.983 ± 1.661 nmol/g tissue; p < 0.05). The tissue VEGF level also significantly increases in a diseased condition (512.466 ± 5.661 pg/mg tissue) versus the nondiseased condition (422.433 ± 13.615 pg/mg tissue). Related trace-element levels show a significant mixed pattern among studied groups. VEGF emerges as the best discriminatory biomarker of breast cancer presence, in accordance with ROC analysis. Oxidative stress and angiogenesis are found to be important factors in breast cancer development. This study forms the basis for future studies that focus on the relationship between roles of indices studied and cancer induction.

Binding of Resveratrol to Vascular Endothelial Growth Factor Suppresses Angiogenesis by Inhibiting the Receptor Signaling

Resveratrol is a polyphenol commonly found in plants and food health products, such as grape and red wine, and was identified for its binding to vascular endothelial growth factor (VEGF) by using HerboChips screening. The binding, therefore, resulted in alterations of VEGF binding to its receptor and revealed the roles of VEGF in angiogenesis. Several lines of evidence gave support to the inhibitory activities of resveratrol in VEGF-triggered angiogenesis. In human umbilical vein endothelial cells (HUVECs), compared with a VEGF-induced group, resveratrol, at a high concentration, suppressed VEGF-mediated endothelial cell proliferation, cell migration, cell invasion, and tube formation by 80 ± 9.01%, 140 ± 3.78%, 110 ± 7.51%, and 120 ± 10.26%, respectively. Moreover, resveratrol inhibited the subintestinal vessel formation in zebrafish embryo. In signaling cascades, application of resveratrol in HUVECs reduced the VEGF-triggered VEGF receptor 2 phosphorylation and c-Jun N-terminal kinase phosphorylation. Moreover, the VEGF-mediated phosphorylations of endothelial nitric oxide synthase, protein kinase B, and extracellular signal-regulated kinase were obviously decreased by (3 ± 0.37)-, (2 ± 0.27)- and (6 ± 0.23)-fold, respectively, in the presence of resveratrol at high concentration. Parallelly, the VEGF-induced reactive oxygen species formation was significantly decreased by 50 ± 7.88% to 120 ± 14.82% under resveratrol treatment. Thus, our results provided support to the antiangiogenic roles of resveratrol, as well as its related signaling mechanisms, in attenuating the VEGF-mediated responses. The present results supported possible development of resveratrol, which should be considered as a therapeutic agent in terms of prevention and clinical treatment of diseases related to angiogenesis.

Bu-Shen-Tong-Luo decoction prevents bone loss via inhibition of bone resorption and enhancement of angiogenesis in ovariectomy-induced osteoporosis of rats

Ethnopharmacological relevanceGathering three ancient formulas, traditional Chinese medicine Bu-Shen-Tong-Luo decoction (BSTLD) has been used to treat postmenopausal osteoporosis (PMO) at the Jiangsu Province Hospital of Chinese Medicine for decades. However, the effect of BSTLD on angiogenesis and bone resorption as well as its possible mechanism are still unknown. Aim of the studyThis study was aimed to evaluate the preventive effect of BSTLD on ovariectomy-induced bone loss and vasculature disorder, and to investigate the possible bone protection mechanism of BSTLD in inhibiting bone resorption by enhancing angiogenesis signaling in ovariectomy-induced osteoporosis of rats. Materials and methodsThe animal experiment was divided into five groups. Rats underwent either sham surgery with intact ovaries (SHAM, n = 10) or bilateral ovariectomy (OVX, n = 40). OVX rats were randomly divided into four groups and gavaged by water (vehicle, 12 mL/kg, n = 10), BSTLD (6 g/kg, n = 10), BSTLD (12 g/kg, n = 10) and 17β-estradiol (E2, 100 μg/kg, n = 10) daily for 12 weeks, respectively. The bone loss and microstructure of the distal femur were observed using micro-computed tomography (μCT). The biomechanical parameters of the femur were detected using three-point bending tests. The distribution of osteoclasts and endothelial cells were analyzed by immunohistochemistry. The mRNA and protein levels of angiogenesis-related hypoxia-inducible factor-1α (HIF-1α) and vascular endothelial growth factor (VEGF), as well as osteoclast activation-related signaling calcitonin receptor (CALCR), cathepsin K (CTSK), receptor activator of NF-κB ligand (RANKL), osteoprotegerin (OPG), and β-catenin were assayed by RT-PCR or Western blot. ResultsBSTLD protected trabecular bone mass density and trabecular bone microstructure from ovariectomy-induced osteoporosis in rats. BSTLD significantly reduced mRNA and protein levels of calcitonin receptor and CTSK in femoral metaphysis and inhibited bone resorption in ovariectomized rats. Furthermore, BSTLD stabilized HIF-1α activity and subsequently increased VEGF expression to enhance angiogenesis and modulated RANKL/OPG signaling in this animal model. ConclusionsThese results demonstrated that BSTLD reduced osteoclasts activation and bone resorption in ovariectomy-induced osteoporosis. Bone protection by BSTLD may be associated with its stimulation of HIF-1α/VEGF angiogenesis signaling and suppression of RANKL/OPG ratio. This study may provide evidence that BSTLD treats postmenopausal osteoporosis, especially with micro-circulation complication.

SiRNA-knockdown of ADAMTS-13 modulates endothelial cell angiogenesis

ADAMTS-13, a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13, is a zinc-containing metalloprotease that cleaves von Willebrand factor (vWf). Previous publications by our laboratory have shown that ADAMTS-13 may also be involved in angiogenesis. For this study, we report the successful transient knockdown of endogenous ADAMTS-13 in human umbilical vein endothelial cells (HUVEC) via siRNA and the effects of reduced endogenous ADAMTS-13 on HUVEC angiogenesis functions. 15nM of ADAMTS-13 siRNA reduced HUVEC ADAMTS-13 protein levels by 90% after 24h incubation, whereas control siRNA did not affect endogenous ADAMTS-13 levels. Furthermore, this transfection did not affect the HUVEC endogenous protein level of ADAMTS-1, a related family member of ADAMTS-13 indicating the specificity of the siRNA. Transfection of HUVEC with 15nM of ADAMTS-13 siRNA resulted in a 21% decrease in proliferation after 24h incubation. The effects of ADAMTS-13 knockdown on migration of HUVEC across a scratch wound were also evaluated. 24h after transfection with control siRNA, there was increased cell migration across the scratch wound. This dramatic migration did not occur with ADAMTS-13 knockdown cells. Decreased protein levels of endogenous ADAMTS-13 also affected angiogenesis as measured by endothelial cell tube formation using a Matrigel matrix method. The tube lengths, sizes and junction numbers of the ADAMTS-13 knockdown cells were all significantly lower compared to control cells by about 40%. The protein level of vascular endothelial growth factor (VEGF), a well-known regulator of angiogenesis, was significantly decreased by 45% upon knockdown of ADAMTS-13. Moreover, activity of the AKT pathway, one of the VEGF angiogenesis downstream signaling pathways was down-regulated by ADAMTS-13 siRNA. These data indicate that in cultured endothelial cells, one role of endogenous ADAMTS-13 is regulation of angiogenesis, mediated through VEGF and AKT signaling pathway. Overall, our data suggest an additional model of endogenous ADAMTS-13 functionality, beyond that of cleaving von Willebrand factor.

Inhibition of AKT signaling by supercritical CO2 extract of mango ginger (Curcuma amada Roxb.) in human glioblastoma cells.

Mango ginger (Curcuma amada Roxb.) is a less-investigated herb for anticancer properties than other related Curcuma species. AKT (a serine/threonine protein kinase B, originally identified as an oncogene in the transforming retrovirus AKT8) plays a central role in the development and promotion of cancer. In this investigation, we have analyzed the effect of supercritical CO2 extract of mango ginger (CA) on the genetic pathways associated with AKT signaling in human glioblastoma cells. The inhibitory effect of supercritical CO2 extract of mango ginger (Curcuma amada) on AKT signaling was investigated in U-87MG glioblastoma cells. CA was highly cytotoxic to glioblastoma cell line (IC50=4.92±0.81 µg/mL) compared to mHypoE-N1 normal mouse hypothalamus cell line (IC50=40.57±0.06 µg/mL). CA inhibits AKT (protein Kinase B) and adenosine monophophate -activated protein kinase α (AMPKα) phosphorylation significantly in a dose-dependent manner. The cell migration which is necessary for invasion and metastasis was also inhibited by CA treatment, with about 43% reduction at 20 µg/mL concentration. Analysis of mRNA and protein expression of genes associated with apoptosis, cell proliferation and angiogenesis showed that CA modulates expression of genes associated with apoptosis (Bax, Bcl-2, Bcl-X, BNIP3, caspase-3, mutant p53 and p21), cell proliferation (Ki67) and angiogenesis vascular endothelial growth factor (VEGF). Additionally, heat shock protein 90 (HSP90) and AMPKα genes interacting with the AKT signaling pathway were also downregulated by CA treatment. These results indicate the molecular targets and mechanisms underlying the anticancer effect of CA in human glioblastoma cells.

Abstract 1388: Inhibition of VEGF and angiopoietin-2 to reduce brain metastases of breast cancer burden

Abstract Introduction: In cancer, vascular destabilization and angiogenesis enhance tumor growth, metastatic potential, and correlate with poor patient outcome. A primary driver of angiogenesis is vascular endothelial growth factor (VEGF), secreted by tumor cells in response to decreased vessel density and hypoxia; and is highly expressed in breast cancer. A secondary driver, angiopoietin-2 (Ang-2), is activated by hypoxia, and induces vessel destabilization upon Tie2 receptor binding. VEGF and Ang-2 have shown to independently and synergistically induce angiogenesis. Preclinical brain metastases models of breast cancer have shown administering bevacizumab results in reduced vascular permeability, and reduces overall metastatic burden in brain. Based upon these observations, we hypothesize that inhibition of both VEGF and angiopoetin-2 will further reduce metastatic burden in brain. Methods: To determine if inhibition of VEGF and Ang-2 results in decreased metastatic burden, a human breast cancer (MDA-MB-231Br) cell line transfected to stably express eGFP was injected into the peripheral circulation via the left cardiac ventricle and CNS metastases grew for 4-6 weeks. As metastases seeded the brain, treatments were administered beginning on day 10. Bevacizumab (10 mg/kg, twice weekly) and L1-10 (Ang-2 inhibitor, 4 mg/kg twice weekly) were administered until day 32, when animals were euthanized and metastatic burden in brain was determined. Results: To confirm that VEGF and Ang-2 synergistically induced angiogenesis in vitro with bevacizumab and L1-10, we used aortic ring and wound healing assays. We observed significant increase (p&amp;lt; 0.01) in branching compared to control at 48 and 72 hours (211 ± 18.2 and 303 ± 47.9 branches) in wells treated with the combination of Ang-2 (100 ng/mL) and VEGF (10 ng/mL). Upon addition of bevacizumab (20 μg/mL), a significant decrease (p&amp;lt; 0.05) in branching was seen at 24 hours (54 ± 10 branches) and 48 hours (161 ± 9.8) but not 72 hours. Similarly, L1-10 (6.5 μg/mL) administration reduced endothelial branching significantly (p&amp;lt; 0.05) at all time points. We observed that nearly all lesions had evidence of hypoxia, VEGF, and Ang-2. We observed the number of metastatic lesions which developed using bevacizumab and L1-10 (10 ± 4) was significantly less (p&amp;lt; 0.001) than bevacizumab treatment (31.6 ± 6) or untreated controls (72 ± 10). The percentage of large lesions (7.7 ± 5) in the combinatorial group was significantly less than bevacizumab treatment (14.6 ± 4; p&amp;lt;0.05) and significantly less (p&amp;lt; 0.05) than un-treated controls (34.6 ± 8). Conclusion: In summary, we demonstrate an integral role of Ang-2 and VEGF in angiogenesis and brain metastases progression. Simultaneous inhibition of these two angiogenic factors may potentially reduce the formation of experimental brain metastases. Further work is required to determine if simultaneous inhibition of VEGF and Ang-2 may be effective to reduce brain metastasis formation. Citation Format: Kaci A. Bohn, Emily R. Sechrest, Chris E. Adkins, Rajendar K. Mittapalli, Mohamed I. Nounou, Tori B. Terrell-Hall, Afroz S. Mohammad, Paul R. Lockman. Inhibition of VEGF and angiopoietin-2 to reduce brain metastases of breast cancer burden. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1388. doi:10.1158/1538-7445.AM2015-1388

Chronic inflammation and colorectal cancer: the role of vascular endothelial growth factor.

Colorectal cancer (CRC) is the third most frequently diagnosed cancer in males and the second in females worldwide. Accumulating evidence has demonstrated that patients with chronic inflammation in bowels have an increased risk to develop CRC. Various inflammatory cells and mediators produced during chronic inflammation are orchestrated through different molecular signaling pathways and lead to the formation of a microenvironment in favor of tumorigenesis. Vascular endothelial growth factor (VEGF), which can be induced by chronic inflammation, plays a pivotal role in tumor angiogenesis as well as tumor growth and metastasis. Antiangiogenic therapy targeting VEGF and its signaling pathways represents a promising strategy to inhibit colorectal tumorigenesis. Indeed, anti-angiogenic agents modulating VEGF ligands and their receptors have already exhibited great potential in treating patients with CRC, especially when combined with conventional chemotherapeutic agents. This review discusses the promoting role of chronic inflammation in colorectal tumorigenesis at different stages including tumor initiation, promotion, progression and metastasis, highlighting the contributory role of VEGF in angiogenesis during the development from chronic inflammation to CRC. It also describes the clinical significance of anti- VEGF therapy in the treatment of such disease.

VEGF-targeted magnetic nanoparticles for MRI visualization of brain tumor

This work is focused on synthesis and characterization of targeted magnetic nanoparticles as magnetic resonance imaging (МRI) agents for in vivo visualization of gliomas. Ferric oxide (Fe3O4) cores were synthesized by thermal decomposition and coated with bovine serum albumin (BSA) to form nanoparticles with Deff of 53±9nm. The BSA was further cross-linked to improve colloidal stability. Monoclonal antibodies against vascular endothelial growth factor (mAbVEGF) were covalently conjugated to BSA through a polyethyleneglycol linker. Here we demonstrate that 1) BSA coated nanoparticles are stable and non-toxic to different cells at concentration up to 2.5mg/mL; 2) conjugation of monoclonal antibodies to nanoparticles promotes their binding to VEGF-positive glioma С6 cells in vitro; 3) targeted nanoparticles are effective in MRI visualization of the intracranial glioma. Thus, mAbVEGF-targeted BSA-coated magnetic nanoparticles are promising MRI contrast agents for glioma visualization. From the Clinical EditorThis work focuses on synthesis and characterization of targeted magnetic nanoparticles as magnetic resonance imaging (МRI) agents for in vivo visualization of gliomas. The authors utilize the fact that high-grade gliomas have extensive areas of necrosis and hypoxia, which results in increased secretion of angiogenesis vascular endothelial growth factor (VEGF). Monoclonal antibodies against vascular endothelial growth factor (mAbVEGF) were covalently conjugated to crosslinked BSA coated ferric oxide (Fe3O4) nanoparticles. The results show that these targeted nanoparticles are effective in MRI visualization of the intracranial glioma and may provide a new and promising contrast agent.

The dual mTORC1 and mTORC2 inhibitor PP242 shows strong antitumor activity in a pheochromocytoma PC12 cell tumor model.

To assess the activity of mTOR and downstream effector proteins in the mTOR pathway after treatment with a dual mTOR complex 1 and 2 (mTORC1/2) inhibitor (PP242) compared with that of mTOR complex 1 (mTORC1) inhibitor (rapamycin) using a xenograft tumor model. Pheochromocytoma PC12 cell were xenografted into nude mice. Animals were treated with PP242 and rapamycin. Mean tumor volume was compared across groups. Terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling staining was used to detect apoptosis. Immunoblot analysis was performed to assess mTORC1/2 activity using p-Akt, p-S6, and p-4E-BP1. The expression of the antiapoptotic protein Bcl-2, pro-apoptotic protein Bax, and the mediator of angiogenesis vascular endothelial growth factor were also investigated. The mean tumor volume of PP242 was significantly lower than in other groups. The terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling results showed that PP242 markedly increased cell apoptosis compared with other groups. Immunoblot analysis of tumor lysates treated with PP242 demonstrated inhibition of activated p-Akt. We also observed that only PP242, but not rapamycin, significantly reduced Bcl-2 expression and markedly increased Bax expression. Rapamycin decreased vascular endothelial growth factor expression, but not nearly as striking as seen in the PP242 group. Our study showed that PP242 showed strong antitumor activity in a pheochromocytoma PC12 cell tumor model. Based on our study, dual mTORC1/2 kinase inhibitors warrant further investigation as a potential treatment for malignant pheochromocytomas or paragangliomas.

The multifaceted activity of VEGF in angiogenesis – Implications for therapy responses

Vascular endothelial growth factor (VEGF) is a key growth factor driving angiogenesis (i.e. the formation of new blood vessels) in health and disease. Pharmacological blockade of VEGF signaling to inhibit tumor angiogenesis is clinically approved but the survival benefit is limited as patients invariably acquire resistance. This is partially mediated by the intrinsic flexibility of tumor cells to adapt to VEGF-blockade. However, it has become clear that tumor stromal cells also contribute to the resistance. Originally, VEGF was thought to specifically target endothelial cells (ECs) but it is now clear that many stromal cells also respond to VEGF signaling, making anti-VEGF therapy more complex than initially anticipated. A more comprehensive understanding of the complex responses of stromal cells to VEGF-blockade might inform the design of improved anti-angiogenic agents.

Emerging targeted therapies in triple-negative breast cancer

Standard chemotherapy regimens can prove effective for patients with early triple-negative breast cancer (TNBC); however, patients with advanced disease typically respond poorly and rapidly progress, and the outcome is poor. New targeted therapies are therefore an urgent unmet medical need for this patient population. Translational and clinical studies into new TNBC treatments have been facilitated by the increased understanding of the aberrant signal transduction pathways regulating growth and survival and the development of chemoresistance in TNBC. Some of the established targeted agents that have been approved in other indications may prove beneficial to patients with TNBC; however, in the absence of approved targeted agents for the treatment of TNBC, most new agents remain experimental. Increased understanding of molecular profiles of TNBC subtypes is likely to improve therapeutic strategies with targeted agents. Novel strategies have reached clinical evaluation in patients with TNBC, including targeting angiogenesis vascular endothelial growth factor and proliferation signalling (receptor tyrosine kinases and mammalian target of rapamycin). Aggressive TNBCs have been found to associate closely with BRCA1 mutation or dysregulation. The recent development of new investigational agents targeting DNA repair, either directly with poly(adenosine disphosphate-ribose) polymerase inhibitors or indirectly through DNA-binding or DNA-damage potentiation, is a major focus of current clinical studies. These and other targeted therapies represent a new approach to TNBC therapy.