Antioxidant and anticancer potential of ethyl acetate extract of bark and flower of Tecoma stans (Linn) and In Silico studies on phytoligands against Bcl 2 and VEGFR2 factors.

This study was designed to appraise the antioxidant and anticancer competence of solvent extracts of Tecoma stans (Linn) and analyze the phytoligands interaction against Bcl 2 VEGFR2 through in silico studies. The phytochemical analysis revealed that the ethyl acetate extract contains more number of pharmaceutically valuable phytochemicals than other solvent extracts. Among the various phytochemicals, flavonoid was found as a predominant component, and UV-Vis- spectrophotometer analysis initially confirmed it. Hence, the column chromatogram was performed to purify the flavonoid, and High-performance liquid chromatography (HPLC) was performed. It revealed that the flavonoid enriched fraction by compared with standard flavonoid molecules. About 84.69% and 80.43% of antioxidant activity were found from ethyl acetate extract of bark and flower at the dosage of 80 µg mL-1 with the IC50 value of 47.24 and 43.40 µg mL-1, respectively. In a dose-dependent mode, the ethyl acetate extract of bark and flower showed cytotoxicity against breast cancer cell line MCF 7 (Michigan Cancer Foundation-7) as up to 81.38% and 80.94% of cytotoxicity respectively. Furthermore, the IC50 was found as 208.507 µg mL-1 and 207.38 µg mL-1 for bark and flower extract correspondingly. About 10 medicinal valued flavonoid components were identified from bark (6) and flower (4) ethyl acetate extract through LC-MS analysis. Out of 10 components, the 3,5-O-dicaffeoylquinic acid (ΔG -8.8) and Isorhamnetin-3-O-rutinoside (ΔG -8.3) had the competence to interact with Bcl 2 (B-Cell Lymphoma 2) and VEGFR2 (Vascular Endothelial Growth Factor Receptor 2) respectively with more energy. Hence, these results confirm that the ethyl acetate extract of bark and flower of T. stans has significant medicinal potential and could be used as antioxidant and anticancer agent after some animal performance study.

[Research Progress of Targeted Ultrasound Contrast Agent BR55].

BR55 is an ultrasound contrast agent targeting vascular endothelial growth factor receptor 2,which can be used to detect tumor neovascularization and improve the diagnostic accuracy.Overseas researchers have used BR55 for human ultrasound molecular imaging,which showed good safety and tolerance.We reviewed the research progress on BR55 applied in the evaluation of tumor neovascularization from the composition,characteristics,animal experiments,and clinical studies of BR55.

Coenzyme Q10 in association with metabolism-related AMPK/PFKFB3 and angiogenic VEGF/VEGFR2 genes in breast cancer patients.

Low levels of coenzyme Q10 (CoQ10) have been reported in the circulation of patients with breast cancer, particularly in metastatic features. Our objective was to study the correlation between plasma levels of CoQ10 and the tumoral expression levels of AMPK, PFKFB3, VEGF, and VEGFR2. This study was a part of consecutive case series conducted on 100 women with newly diagnosed invasive ductal breast carcinoma, with an age range of 30-60 years. Plasma levels of CoQ10 were measured using HPLC coupled to an UV detector. The expression levels were quantified using quantitative real-time PCR. Structural equation modeling (SEM) was applied to generate pathways describing gene-to-gene inter-correlations. Using SEM identified AMPK expression to contribute positively to VEGF-A/VEGFR2 ratio (coefficient b = 0.64, P < 0.001). The VEGFR2 expression positively correlated with tumor size (coefficient b = 0.31, P < 0.001). A linear correlation between expression levels of AMPK and PFKFB3 was observed (rAdj = - 0.273, P = 0.02). Similarly, VEGF-A was correlated with VEGFR2 (rAdj = 0.698, P < 0.001). There were inverse significant correlations between CoQ10 and the fold changes of AMPK (rAdj = - 0.276, P = 0.030), VEGF-A (rAdj = - 0.319, P = 0.011) and VEGFR2 (rAdj = - 0.262, P = 0.045). The correlation between CoQ10 and the fold changes of PFKFB3 was significantly progesterone receptor (PR) dependent (rAdj = - 0.284, P = 0.041). Plasma CoQ10 was correlated with VEGF-A in hormone receptor-dependent mode (ER + : rAdj = - 0.286, P = 0.032 and PR + : rAdj = - 0.313, P = 0.025). Our findings could provide new insights suggesting CoQ10 can inversely correlate to the expression levels of VEGF-A/VEGFR2 as angiogenic factors and AMPK/PFKFB3 as biomarkers for tumoral glycolysis, especially in a hormone receptor-dependent manner to possibly prevent the progression of breast carcinogenesis.

Carvacrol alters soluble factors in HCT-116 and HT-29 cell lines

Background/aim: Natural products are popular insights for researchers to investigate promising anti-cancer agents since some of these substances have lesser adverse effects restricting the treatment than traditional chemotherapeutic agents. A well-known monoterpene Carvacrol, widely consumed in Mediterranean cuisine and lower risks of cancer, has efficient anticancer effects. However, the mechanism of action is yet to be discovered. Materials and methods: The investigation aims to illuminate a new perceptive in the role of this substance on colorectal cancer treatment, by the means of differences in a well-defined range of soluble factors. Carvacrol effect on both HT-29 and HCT-116 cell lines was evaluated on proliferation and the IC50 values were calculated by the RTCA xCELLigence device. Then MAGPIX assay was performed to obtain the changes in soluble factors of the cell lines. Results: The Multiplexing assay suggests some of these factors were altered in favor of surviving and proliferation in aggressive cell line HCT-116 whereas they were altered against these characters in HT-29, were correlated with the increased IC50 concentration of HCT- 116 in carvacrol treatment. Conclusion: The current study indicates that differences in the levels of these soluble factors could modulate the anticancer effect related to carvacrol.

MRI analysis of hydrogel-loaded apatinib for local therapy of hepatocellular carcinoma model in nude mice.

AIM: To investigate the effect of local treatment of gadolinium-polyethylene glycol (Gd-PEG) hydrogel containing apatinib injected into hepatocellular carcinoma model of HepG2 in nude mice, and to evaluate the MRI findings in vivo. METHODS: HepG2 cells were treated in vitro and OD 450 value were measured. The four groups (n = 6) were Apatinib-Gd-PEG hydrogel, Gd-PEG hydrogel, Apatinib, and Saline. T1WI and DWI scans were performed before and 1d, 3d, and 14d postoperatively. The samples were examined by histomorphology and immunohistochemistry for CD34 and VEGFR2. Microvessel density (MVD) was evaluated and the average optical density (AOD) of VEGFR2 was obtained by IPP6.0 image software. RESULTS: The OD450-time curves of Gd-PEG hydrogel and phosphate buffer saline (PBS) were similar and that of apatinib at all concentrations are located below; the higher the concentration, the lower the curve. On T1WI and DWI, the newly injected Gd-PEG hydrogel showed significant high signal and was immobilized in the tumor. Subsequently, the size and signal of Gd-PEG hydrogel gradually decreased with time. In Apatinib-Gd-PEG hydrogel group, compared with other three groups, MRI and histomorphology showed that the necrotic area of hepatocellular carcinoma model was larger, immunohistochemistry displayed minimal expression of CD34 and VEGFR2, the AOD of VEGFR2 and MVD differed markedly. CONCLUSION: Gd-PEG hydrogel can significantly enhance and prolong the inhibitory effect of apatinib. It can be visualized by MRI, which can be used to evaluate the local therapeutic effect.

Interferon-Gamma and Tumor Necrosis Factor-Related Weak Inducer of Apoptosis Expression in Neoangiogenesis in Colorectal Polypoid Lesions.

BACKGROUND: Interferon gamma (IFNγ) and tumor necrosis factor-related weak inducer of apoptosis (TWEAK) molecules seem to have a potential effect on angiogenic factors such as vascular endothelial growth factor (VEGF). The aim of this study was to assess a possible interplay between IFNγ and TWEAK cytokines and VEGF machinery in the different steps of colorectal carcinogenesis. METHODS: A total of 92 subjects with colonic adenoma or cancer who underwent screening colonoscopy or surgery were prospectively enrolled. Polypoid lesion tissue samples were collected and frozen. Real-time reverse transcription polymerase chain reaction for IFNγ, TWEAK, and VEGF-A mRNA expression was performed. Immunoassays for VEGF-A, VEGF-C, VEGFR-1, VEGFR-2, and VEGFR-3 were also performed. Nonparametric statistics, receiver operating characteristic curve analysis, and logistic multiple regression analysis were used. RESULTS: IFNγ and TWEAK mRNA expression was higher in patients with T2 or more advanced colorectal cancer than in those with adenomas or T1 cancer (p < 0.001 and p = 0.01, respectively). IFNγ and TWEAK mRNA expression levels directly correlated with VEGF-A mRNA expression levels (rho = 0.44, p < 0.001 and rho = 0.29, p = 0.004, respectively). On the contrary, IFNγ and TWEAK mRNA expression levels inversely correlated with VEGF-C protein levels (rho = -0.29, p = 0.04 and rho = -0.31, p = 0.03, respectively). Similarly, IFNγ and TWEAK mRNA expression levels inversely correlated with VEGFR2 protein levels (rho = -0.38, p = 0.033 and rho = -0.40, p = 0.025, respectively). CONCLUSION: This study showed that in colorectal polypoid lesions, IFNγ and TWEAK expressions are directly correlated to VEGF-A expression but inversely correlated with VEGFR2 levels, suggesting a possible feedback mechanism in the regulation of VEGF-A expression.

Click Conjugation of Cloaked Peptide Ligands to Microbubbles.

Interest in the use of targeted microbubbles for ultrasound molecular imaging (USMI) has been growing in recent years as a safe and efficacious means of diagnosing tumor angiogenesis and assessing response to therapy. Of particular interest are cloaked microbubbles, which improve specificity by concealing the ligand from blood components until they reach the target vasculature, where the ligand can be transiently revealed for firm receptor-binding by ultrasound acoustic radiation force pulses. Herein, a bio-orthogonal "click" conjugation chemistry is introduced to decorate the surface of cloaked 4-5-µm-diameter microbubbles as part of a sterile and reproducible production process. Azido-functionalized antagonists for the angiogenic biomarkers αVß3 integrin (cRGD) and VEGFR2 (A7R) proteins were conjugated to bimodal-brush microbubbles via strain-promoted [3 + 2] azide-alkyne cycloaddition (SPAAC) click chemistry. Ligand conjugation was validated by epifluorescent microscopy, flow cytometry, and Fourier-transform infrared spectroscopy. Sterility was validated by bacterial culture and endotoxin analysis. Additionally, clinically normal dogs receiving escalating microbubble doses were shown to experience no pathologic changes in physical examination, complete blood count, serum biochemistry profile, or coagulation panel. This bio-orthogonal microbubble conjugation process for cloaked peptide ligands may be leveraged for future USMI studies of tumor angiogenesis for translation to preclinical and clinical applications.

The effect of antioxidants on angiogenesis in uterine transplantation.

The aim of this study was to investigate the effect of antioxidants on angiogenesis in uterine transplantation. We used 24 female rats equally divided into four groups: Group 1 had the uterus stored in HTK (Histidine-Tryptophan-Ketoglutarate) solution at 4 °C cold storage for 4 h. Group 2 had the uterine tissue stored in HTK solution combined with acetyl L-carnitine (10-8 M) for 4 h at +4 °C. The same procedures with Group 1 and 2 were repeated for 24 h for Groups 3 and 4, respectively. Histological investigation and immunohistochemical analysis were performed. Histological findings showed that storing donor uterus in HTK solution at +4° C for 24 h results in histological alteration in uterus. We also found that immunoreactivity of VEGFR-2 in all layers of rat uterus in Group 2 was lower than that in Group 1, and the expression of the uterus in Group 4 was lower than that in Group 3. We concluded that antioxidant acetyl L-carnitine, which was added to the organ preservation solution HTK, had prevented the formation of free radicals, and thus protected the uterus that was stored in short and long cold storage periods. Impact statement What is already known on this subject? Ischemia-reperfusion is a complex pathophysiological process involve in hypoxia and/or reoxygenation, ionic imbalance-induced oedema and acidosis, oxidative stress, mitochondrial uncoupling, coagulation and endothelium activation. The composition of preservation solutions must be adapted to the severity of ischaemia-reperfusion injuries to reduce cellular damage and inflammation and preserve graft functionality and integrity, thus improving short-term and long-term graft outcome. Clinicians use three types of composition of solution for static cold preservation: intracellular, intermediate and extracellular. HTK will be used frequently, especially with the consideration of lower price and more easy handling aspects. L-carnitine acts as an antioxidant, protects against free radicals and prevents mitochondrial damage. VEGFR-2 plays an important role in angiogenesis, chemotaxis, proliferation and migration of endothelial cells. What this study adds? In this study, we investigate the effect of antioxidants on angiogenesis in uterus transplantation. Our results showed that antioxidant acetyl L-carnitine that added to the organ preservation solution HTK, has prevented the formation of free radicals, thus protect the uterus that was stored in short and long cold storage periods. What the implications are for future studies? Therefore, we will contribute to the literature with the results of this study.

Hedgehog signalling pathway orchestrates angiogenesis in triple-negative breast cancers.

BACKGROUND: Several evidences suggest a marked angiogenic dependency in triple-negative breast cancer (TNBC) tumorigenesis and a potential sensitivity to anti-angiogenic agents. Herein, the putative role of Hedgehog (Hh) pathway in regulating TNBC-dependent angiogenesis was investigated. METHODS: Expression and regulation of the Hh pathway transcription factor glioma-associated oncogene homolog1 protein (GLI1) were studied on the endothelial compartment and on TNBC-initiated angiogenesis. To evaluate the translational relevance of our findings, the combination of paclitaxel with the Smo inhibitor NVP-LDE225 was tested in TNBC xenografted mice. RESULTS: Tissue microarray analysis on 200 TNBC patients showed GLI1 overexpression paired with vascular endothelial growth factor receptor 2 (VEGFR2) expression. In vitro, Hh pathway promotes TNBC progression in an autocrine manner, regulating the VEGF/VEGFR2 loop on cancer cell surface, and in a paracrine manner, orchestrating tumour vascularisation. These effects were counteracted by Smo pharmacological inhibition. In TNBC xenografted mice, scheduling NVP-LDE225 rather than bevacizumab provided a better sustained inhibition of TNBC cells proliferation and endothelial cells organisation. CONCLUSIONS: This study identifies the Hh pathway as one of the main regulators of tumour angiogenesis in TNBC, thus suggesting Hh inhibition as a potential new anti-angiogenic therapeutic option to be clinically investigated in GLI1 overexpressing TNBC patients.

Biological relevance of tissue factor and IL-6 in arteriovenous malformations.

Arteriovenous malformations (AVMs) are congenital abnormal vessels that shunt blood directly from the arterial to the venous system without a capillary bed. The underlying pathology of AVMs is not fully understood. The objective of the study was to determine the association between the expression patterns of tissue factor (TF) and interleukin-6 (IL-6) in AVMs with clinical and pathological findings. Eighteen cases of sporadic AVM with operative specimens were included in this study. The expression of messenger RNA (mRNA) of TF and IL-6 was assayed, and association with clinical factors was investigated. The distribution of TF and IL-6 was examined with immunofluorescence. The mRNA expression of TF was significantly higher in AVM specimens than in control tissues (P = 0.002) and significantly higher in the symptomatic group than in the asymptomatic group (P = 0.037). The mRNA expression of IL-6 was likewise significantly higher in AVM specimens than in control tissues (P = 0.038). Examination of immunostained sections indicated that TF+ cells were also positive for IL-6 and were distributed around normal endothelial cells and pericytes. Moreover, TF+/IL-6+ cells also expressed CD31, vascular endothelial growth factor receptor 2 (VEGFR2), and platelet-derived growth factor receptor beta (PDGFR-beta). These results suggest that TF is elevated in AVMs and that it mediates symptomatic events. IL-6 is associated with the angiogenic activity of TF, and both are present in the same abnormal endothelial cells and pericytes. These factors may have interactive effects and may serve in a prognostic role for AVMs.

Biomarker analyses in REGARD gastric/GEJ carcinoma patients treated with VEGFR2-targeted antibody ramucirumab.

BACKGROUND: Angiogenesis inhibition is an important strategy for cancer treatment. Ramucirumab, a human IgG1 monoclonal antibody that targets VEGF receptor 2 (VEGFR2), inhibits VEGF-A, -C, -D binding and endothelial cell proliferation. To attempt to identify prognostic and predictive biomarkers, retrospective analyses were used to assess tumour (HER2, VEGFR2) and serum (VEGF-C and -D, and soluble (s) VEGFR1 and 3) biomarkers in phase 3 REGARD patients with metastatic gastric/gastroesophageal junction carcinoma. METHODS: A total of 152 out of 355 (43%) patients randomised to ramucirumab or placebo had ⩾1 evaluable biomarker result using VEGFR2 immunohistochemistry or HER2, immunohistochemistry or FISH, of blinded baseline tumour tissue samples. Serum samples (32 patients, 9%) were assayed for VEGF-C and -D, and sVEGFR1 and 3. RESULTS: None of the biomarkers tested were associated with ramucirumab efficacy at a level of statistical significance. High VEGFR2 endothelial expression was associated with a non-significant prognostic trend toward shorter progression-free survival (high vs low HR=1.65, 95% CI=0.84,3.23). Treatment with ramucirumab was associated with a trend toward improved survival in both high (HR=0.69, 95% CI=0.38, 1.22) and low (HR=0.73, 95% CI=0.42, 1.26) VEGFR2 subgroups. The benefit associated with ramucirumab did not appear to differ by tumoural HER2 expression. CONCLUSIONS: REGARD exploratory analyses did not identify a strong potentially predictive biomarker of ramucirumab efficacy; however, statistical power was limited.

VEGF receptor subtypes may serve as novel prognostic factors and putative indicators for anti VEGF receptor treatment response in renal cell carcinoma cases.

PURPOSE: Targeted therapies are novel treatment options for renal cell carcinoma (RCC). Of the target molecules investigated, vascular endothelial growth factor receptors (VEFGRs) were seldom evaluated. The current study investigated the prognostic significance of VEGFRs and IMP-3 as a potential prognostic markers. METHODS: Pathological material and clinical files of 100 patients with RCC were retrospectively evaluated. For each case, the clinical outcome and disease stage were assessed and resected materials were histologically reevaluated. VEGFR-2, VEGFR-3 and IMP-3 expression of tumor samples were analyzed with immunohistochemistry. These expressions were compared with prognosis and clinicopathological variables. RESULTS: Five-year overall survival (OS) was 80% in the whole cohort. Mean survival was 20.3±1.9 months in metastatic disease (95%CI:16.4-24.2). Two-year OS was 20% and 5-year OS was zero in the metastatic group. Survival was significantly longer in VEGFR-2 expressing group than in the nonexpressing group (78.7±2.6 vs 63.9±6; 95%CI:73.7-84 and 52.1-75.7, respectively; p=0.031). VEGFR-3 and IMP-3 expressions were not significantly correlated with survival. In the non-metastatic group mean OS was 82.6±2.1 months and 2- and 5-year OS were 96 and 88%, respectively. CONCLUSIONS: Since VEGFRs were expressed on all histological subtypes and significantly correlated with survival, assessment of VEGFR-2 and VEGFR-3 on tumor samples might serve as a putative prognostic factor in RCC cases. These expressions might identify a subset of patients that may benefit from antiangiogenic treatments targeting VEGFR receptors.

Emerging roles of post-translational modifications in signal transduction and angiogenesis.

The vascular endothelial growth factor receptor-2 (VEGFR-2) belongs to the family of receptor tyrosine kinases and is a key player in vasculogenesis and pathological angiogenesis. An emerging picture of PTMs of VEGFR-2 suggests that they play central roles in generating a highly dynamic and complex signaling system that regulates key angiogenic responses ranging from endothelial cell differentiation, proliferation, migration to permeability. Recent MS analysis of VEGFR-2 uncovered previously unrecognized PTMs on VEGFR-2 with a distinct function. The ligand binding extracellular domain of VEGFR-2 is composed of seven immunoglobulin-like domains highly decorated with N-glycosylation, while its cytoplasmic domain is subject to multiple PTMs including Tyr, Ser/Thr phosphorylation, Arg and Lys methylation, acetylation and ubiquitination. Here we review the PTMs on VEGFR-2, their importance in angiogenic signaling relays and possible novel therapeutic potentials.

Cilengitide downmodulates invasiveness and vasculogenic mimicry of neuropilin 1 expressing melanoma cells through the inhibition of αvß5 integrin.

During melanoma progression, tumour cells show increased adhesiveness to the vascular wall, invade the extracellular matrix (ECM) and frequently form functional channels similar to vascular vessels (vasculogenic mimicry). These properties are mainly mediated by the interaction of integrins with ECM components. Since we had previously identified neuropilin 1 (NRP-1), a coreceptor of vascular endothelial growth factor A (VEGF-A), as an important determinant of melanoma aggressiveness, aims of this study were to identify the specific integrins involved in the highly invasive phenotype of NRP-1 expressing cells and to investigate their role as targets to counteract melanoma progression. Melanoma aggressiveness was evaluated in vitro as cell ability to migrate through an ECM layer and to form tubule-like structures using transfected cells. Integrins relevant to these processes were identified using specific blocking antibodies. The αvß5 integrin was found to be responsible for about 80% of the capability of NRP-1 expressing cells to adhere on vitronectin. In these cells αvß5 expression level was twice higher than in low-invasive control cells and contributed to the ability of melanoma cells to form tubule-like structures on matrigel. Cilengitide, a potent inhibitor of αν integrins activation, reduced ECM invasion, vasculogenic mimicry and secretion of VEGF-A and metalloproteinase 9 by melanoma cells. In conclusion, we demonstrated that ανß5 integrin is involved in the highly aggressive phenotype of melanoma cells expressing NRP-1. Moreover, we identified a novel mechanism that contributes to the antimelanoma activity of the αv integrin inhibitor cilengitide based on the inhibition of vasculogenic mimicry.

Vascular endothelial growth factor receptor type 2-targeted contrast-enhanced US of pancreatic cancer neovasculature in a genetically engineered mouse model: potential for earlier detection.

PURPOSE: To test ultrasonographic (US) imaging with vascular endothelial growth factor receptor type 2 (VEGFR2)-targeted microbubble contrast material for the detection of pancreatic ductal adenocarcinoma (PDAC) in a transgenic mouse model of pancreatic cancer development. MATERIALS AND METHODS: Experiments involving animals were approved by the Institutional Administrative Panel on Laboratory Animal Care at Stanford University. Transgenic mice (n = 44; Pdx1-Cre, KRas(G12D), Ink4a(-/-)) that spontaneously develop PDAC starting at 4 weeks of age were imaged by using a dedicated small-animal US system after intravenous injection of 5 × 10(7) clinical-grade VEGFR2-targeted microbubble contrast material. The pancreata in wild-type (WT) mice (n = 64) were scanned as controls. Pancreatic tissue was analyzed ex vivo by means of histologic examination (with hematoxylin-eosin staining) and immunostaining of vascular endothelial cell marker CD31 and VEGFR2. The Wilcoxon rank sum test and linear mixed-effects model were used for statistical analysis. RESULTS: VEGFR2-targeted US of PDAC showed significantly higher signal intensities (26.8-fold higher; mean intensity ± standard deviation, 6.7 linear arbitrary units [lau] ± 8.5; P < .001) in transgenic mice compared with normal, control pancreata of WT mice (mean intensity, 0.25 lau ± 0.25). The highest VEGFR2-targeted US signal intensities were observed in smaller tumors, less than 3 mm in diameter (30.8-fold higher than control tissue with mean intensity of 7.7 lau ± 9.3 [P < .001]; and 1.7-fold higher than lesions larger than 3 mm in diameter with mean intensity of 4.6 lau ± 5.8 [P < .024]). Ex vivo quantitative VEGFR2 immunofluorescence demonstrated that VEGFR2 expression was significantly higher in pancreatic tumors (P < .001; mean fluorescent intensity, 499.4 arbitrary units [au] ± 179.1) compared with normal pancreas (mean fluorescent intensity, 232.9 au ± 83.7). CONCLUSION: US with clinical-grade VEGFR2-targeted microbubbles allows detection of small foci of PDAC in transgenic mice.

Vascular endothelial growth factor receptor 1 expression in nasal polyp tissue.

BACKGROUND: Edema represents a key feature of nasal polyp (NP) disease. Members of the vascular endothelial growth factor (VEGF) family may be involved, but the precise role of VEGF-A, VEGF-B, placental growth factor (PlGF), and their receptors VEGFR1 and VEGFR2 in NP edema formation remains elusive. OBJECTIVE: Exploring the expression of VEGF family members and their receptors and their correlation with clinical, radiological, and edema markers in NP. METHODS: The expression of VEGF-A, VEGF-B, PlGF, VEGFR1, and VEGFR2 was measured in NP (n = 23) and control tissue (n = 22) at mRNA and protein level. Edema was evaluated by measuring albumin levels and wet/dry ratios. Computed tomography (CT) scans were scored using the Lund-Mackay scoring system. IL-5 mRNA expression was determined by real-time RT-PCR. Cell suspensions from NP (n = 10) and control tissue (n = 12) were stimulated in vitro with IL-1ß or TNFα. RESULTS: mRNA expression of VEGFR1 and VEGF-B was significantly higher in NP compared with control tissue. Expression levels of VEGF-B and VEGFR1 significantly correlated with NP albumin content (VEGF-B: P = 0.0208; VEGFR1: P = 0.0293), CT scan scores (VEGF-B: P = 0.0075; VEGFR1: P = 0.0068), and IL-5 mRNA (VEGF-B: P = 0.0027; VEGFR1: P = 0.0001). In vitro stimulation of control and NP tissue cell suspensions with IL-1ß or TNFα significantly reduced the expression of VEGFR2 in control tissue, without altering VEGFR1 and VEGF-B expression. hVEGF-B induced nitric oxide production in NP macrophages (P < 0.05). CONCLUSION: Expression levels of VEGFR1 and VEGF-B correlate with edema and clinical markers of NP disease and therefore represent potential therapeutic targets.

Effects of the vascular endothelial growth factor receptor-2 (VEGFR-2) inhibitor SU5416 on in vitro cultures of Plasmodium falciparum.

BACKGROUND: Vascular endothelial growth factor (VEGF) is taken up by parasitized red blood cells during malaria and stimulates intra-erythrocytic growth of Plasmodium falciparum in vitro. The cause and consequence of this uptake is not understood. METHODS: Plasmodium falciparum was cultured in vitro. Parasite growth and intracellular VEGF levels were assessed using flow cytometry. Intracellular VEGF was visualized by fluorescence immunocytochemistry. Phosphorylated tyrosine was measured by western blotting. In vivo assessment of intra-erythrocytic VEGF was performed in Plasmodium berghei ANKA-infected C57BL/6 mice. RESULTS: VEGF accumulated intracellularly in infected red blood cells, particularly in schizonts. In vitro growth of P. falciparum was unchanged when co-cultured with the anti-VEGF antibody bevacizumab or with an anti-VEGF receptor-1 peptide. In contrast, the VEGF receptor-2 inhibitor, SU5416, dose-dependently inhibited growth. None of the treatments reduced intracellular VEGF levels. Thus, the anti-parasitic effect of SU5416 seemed independent of VEGF uptake. SU5416 reduced phosphorylated tyrosine in parasitized red blood cells. Similarly, the broad-spectrum tyrosine kinase inhibitor genistein dose-dependently inhibited P. falciparum growth and reduced tyrosine phosphorylation. Neither bevacizumab nor anti-VEGF receptor-1 peptide affected tyrosine kinase activity. Finally, in vivo uptake of VEGF in P. berghei ANKA was demonstrated, analogous to the in vitro uptake in P. falciparum, making it a possible model for the effects of VEGF signalling in vivo during malaria. CONCLUSIONS: Inhibition of VEGFR-2 signalling reduces intra-erythrocytic growth of P. falciparum, likely due to tyrosine kinase inhibition. Internalisation of VEGF in P. falciparum-infected red blood cells does not rely on VEGF receptors. The function of in vivo uptake of VEGF can be studied in rodent malaria models.

Vascular progenitor clusters from peripheral blood in cancer patients following oncologic surgery.

INTRODUCTION: Vascular progenitor cells (VPCs) are recruited into the peripheral blood (PB) following ischemia and inflammation and correlate with vascular health. The impact of recruiting VPCs on surgical recovery and cancer progression following tumor resection remain unknown. METHODS: We measured VPC clusters and enumerated circulating CD34+ VEGFR2+ angiogenic cells in 18 patients with oral cancer (OC) undergoing resection and free flap reconstruction (high vascular injury) and in 18 patients undergoing colorectal cancer resection (CRC) (low vascular injury) at baseline and multiple timepoints after surgery. RESULTS: VPC clusters increased following OC resection, peaking on Day +3 and returning to baseline by Day 28. In contrast, VPC clusters decreased sharply on Day +3 in patients with CRC before returning to baseline. CD34+ VEGFR2+ cells did not increase significantly after surgery. More rapid clinical recovery following OC resection was observed in patients with greater VPC cluster levels on Day +3. Tumor size and subsequent progression of cancer did not correlate with recruitment of VPC cluster-forming cells. CONCLUSION: VPC recruitment following cancer resection may depend on cancer subtype and may relate to the degree of surgical stress and vascular injury. Recovery after surgery for OC may be accelerated in patients with greater VPC recruitment.

Comparison of adenoid cystic carcinomas arising from the parotid gland vs. the submandibular gland: focus on systemic metastasis and tumor-associated blood vessels.

BACKGROUND: Although several studies reported that distant metastasis occurs more frequently in the tumors of submandibular gland (SMG) than parotid gland (PG), why SMG tumors preferentially metastasize to distant organs is not fully understood. We aimed to identify the differential tumor microenvironment for distant metastasis and possible underlying mechanisms. METHODS: We retrieved 27 cases of 1-4-cm-sized adenoid cystic carcinomas (ACCs) arising from the PG (n = 12) and SMG (n = 15). c-KIT, VEGF-R2, and CD31 staining were quantified by image-based analysis to define the positive expression or tumor-associated vessel areas in two representative sections per case. In addition, angiogenesis-related genomic expression profiling was carried out to explore the underlying mechanism, which was confirmed by RT-PCR and immunohistochemistry. RESULTS: Earlier systemic dissemination within 2 years was detected exclusively in SMG ACCs (5/15). The area of tumor-associated blood vessels was larger in SMG ACCs than PG ACCs, and ACCs showing distant metastasis had greater blood vessel area than those without metastasis. Interestingly, normal SMG had more blood vessels per area than PG. Among angiogenesis-related signals, the level of IL-6 was significantly lower in SMG ACCs than PG ACCs. Moreover, IL-6 expression decreased significantly in SMG ACCs compared with that in normal SMG, whereas it was up-regulated in PG ACCs. CONCLUSION: ACCs in the SMG microenvironment have more abundant tumor-associated blood vessels than PG ACCs, which may explain the higher risk of distant metastasis from SMG tumors.

Circulating hematopoietic progenitor cells are decreased in COPD.

RATIONALE: Bone marrow derived progenitor cells participate in the repair of injured vessels. The lungs of individuals with emphysema have reduced alveolar capillary density and increased endothelial apoptosis. We hypothesized that circulating levels of endothelial and hematopoietic progenitor cells would be reduced in this group of patients. OBJECTIVES: The goal of this study was to measure circulating levels of endothelial progenitor cells (EPCs) and hematopoietic progenitor cells (HPCs) in subjects with COPD and to determine if progenitor levels correlated with disease severity and the presence of emphysema. METHODS: Peripheral blood mononuclear cells were isolated from 61 patients with COPD and 32 control subjects. Levels of EPCs (CD45(dim) CD34+) and HPCs (CD45(+) CD34(+) VEGF-R2(+)) were quantified using multi-parameter flow cytometry. Progenitor cell function was assessed using cell culture assays. All subjects were evaluated with spirometry and CT scanning. MEASUREMENTS AND MAIN RESULTS: HPC levels were reduced in subjects with COPD compared to controls, whereas circulating EPC levels were similar between the two groups. HPC levels correlated with severity of obstruction and were lowest in subjects with severe emphysema. These associations remained after correction for factors known to affect progenitor cell levels including age, smoking status, the use of statin medications and the presence of coronary artery disease. The ability of mononuclear cells to form endothelial cell colony forming units (EC-CFU) was also reduced in subjects with COPD. CONCLUSIONS: HPC levels are reduced in subjects with COPD and correlate with emphysema phenotype and severity of obstruction. Reduction of HPCs may disrupt maintenance of the capillary endothelium, thereby contributing to the pathogenesis of COPD.