Vascular permeability factor (VPF, VEGF) in tumor biology

MiR-221-induced PUMA silencing mediates immune evasion of bladder cancer cells

Immune evasion of cancer cells is mainly due to the impaired transduction of apoptotic signals from immune cells to cancer cells, as well as inhibition of subsequent apoptosis signal cascades within the cancer cells. Over the past few decades, the research has focused more on the impaired transduction of the apoptotic signal from immune cells to cancer cells, rather than inhibition of the intracellular signaling pathways. In this study, miR‑221 inhibitor was transfected into bladder cancer cell lines 5637, J82 and T24 to repress the expression of miR‑221. As a result, the repression of miR‑221 on p53 upregulated modulator of apoptosis (PUMA) was abolished, resulting in increased expression of the pro-apoptotic Bax and reduced expression of the anti-apoptotic Bcl-2, which promotes apoptosis of bladder cancer cells. The expression of MMP-2, MMP-9 and VEGF-C were reduced, resulting in reduced invasiveness and infiltration capability of bladder cancer cells, thereby inhibiting the immune evasion of bladder cancer cells.

Endothelial cell-initiated extravasation of cancer cells visualized in zebrafish

The extravasation of cancer cells, a key step for distant metastasis, is thought to be initiated by disruption of the endothelial barrier by malignant cancer cells. An endothelial covering-type extravasation of cancer cells in addition to conventional cancer cell invasion-type extravasation was dynamically visualized in a zebrafish hematogenous metastasis model. The inhibition of VEGF-signaling impaired the invasion-type extravasation via inhibition of cancer cell polarization and motility. Paradoxically, the anti-angiogenic treatment showed the promotion, rather than the inhibition, of the endothelial covering-type extravasation of cancer cells, with structural changes in the endothelial walls. These findings may be a set of clues to the full understanding of the metastatic process as well as the metastatic acceleration by anti-angiogenic reagents observed in preclinical studies.

Expression of the vascular endothelial growth factor receptor system in porcine oviducts after induction of ovulation and superovulation

This study was performed to determine the influence of insemination as well as treatment with human chorionic gonadotropin (hCG) and equine chorionic gonadotropin (eCG) on expression of the vascular endothelial growth factor (VEGF) system in porcine oviducts. In the first experiment, 10 gilts were assigned to 2 groups: cyclic (treated with phosphate-buffered saline; n = 5) and inseminated (n = 5). In experiment II, 15 gilts were assigned to 3 groups: inseminated (control; n = 5), induced ovulation and inseminated (750 IU eCG, 500 IU hCG; n = 5), and superovulated and inseminated (1500 IU eCG, 1000 IU hCG; n = 5). Oviducts (isthmus and ampulla) were collected 3 days after phosphate-buffered saline treatment (experiment I) or insemination. Blood samples were collected during slaughter for E2 (estradiol) and P4 (progesterone) analysis. Levels of messenger RNA (mRNA) of the VEGF system were analyzed by real-time polymerase chain reaction and protein by Western blot and E2 and P4 using radioimmunoassays. Insemination by itself decreased VEGF120 mRNA expression and VEGF-A protein level in the oviductal isthmus (P < 0.05) but did not alter VEGF164 mRNA. Expression of Flt-1 (c-fms-like tyrosine kinase VEGFR-1) mRNA increased in the isthmus of inseminated relative to cyclic gilts (P < 0.05), whereas KDR (fetal liver kinase-1 VEGFR-2) mRNA levels decreased in both the oviductal isthmus (P < 0.05) and ampulla (P < 0.001). Superovulation decreased VEGF120 and VEGF164 mRNA expression in the isthmus compared with the inseminated group (P < 0.05), and lowered protein levels of VEGF-A in the isthmus of both stimulated groups (P < 0.001). Expression of Flt-1 mRNA was affected by hCG and eCG treatment in both gonadotropin-stimulated groups in the isthmus as well as in the ampulla (P < 0.001) and protein levels in the ampulla of superovulated gilts (P < 0.05). Protein levels of KDR were reduced in the oviductal ampulla of gilts in both the induced ovulation and superovulated groups (P < 0.05). The concentrations of both E2 and P4 increased significantly in superovulated group of gilts (P < 0.01 and P < 0.05 for E2 and P4, respectively). Our study showed that insemination alone as well as ovarian stimulation affected the mRNA and protein profiles of the VEGF system in the porcine oviduct. Disrupted VEGF system expression may be crucial to many events occurring during the periovulatory period and consequently could lead to deprivation of VEGF-dependent factors that are necessary for proper fertilization, gamete transport, and embryo development.

Poxue Huayu and Tianjing Busui Decoction for cerebral hemorrhage (Upregulation of neurotrophic factor expression): Upregulation of neurotrophic factor expression

This study established a rat model of cerebral hemorrhage by injecting autologous anticoagulated blood. Rat models were intragastrically administered 5, 10, 20 g/kg Poxue Huayu and Tianjing Busui Decoction, supplemented with Hirudo, raw rhubarb, raw Pollen Typhae, gadfly, Fructrs Trichosanthis, Radix Notoginseng, Rhizoma Acori Talarinowii, and glue of tortoise plastron, once a day, for 14 consecutive days. Results demonstrated that brain water content significantly reduced in rats with cerebral hemorrhage, and intracerebral hematoma volume markedly reduced after treatment. Immunohistochemical staining revealed that brain-derived neurotrophic factor, tyrosine kinase B and vascular endothelial growth factor expression noticeably increased around the surrounding hematoma. Reverse transcription-PCR revealed that brain-derived neurotrophic factor and tyrosine kinase B mRNA expression significantly increased around the surrounding hematoma. Neurologic impairment obviously reduced. These results indicated that Poxue Huayu and Tianjing Busui Decoction exert therapeutic effects on cerebral hemorrhage by upregulating the expression of brain-derived neurotrophic factor.

Recombinant Goat VEGF164 Increases Hair Growth by Painting Process on the Skin of Shaved Mouse

To detect goat vascular endothelial growth factor (VEGF)-mediated regrowth of hair, full-length VEGF164 cDNA was cloned from Inner Mongolia cashmere goat (Capra hircus) into the pET-his prokaryotic expression vector, and the recombinant plasmid was transferred into E. coli BL21 cells. The expression of recombinant 6×his-gVEGF164 protein was induced by 0.5 mM isopropyl thio-β-D-galactoside at 32°C. Recombinant goat VEGF164 (rgVEGF164) was purified and identi ed by western blot using monoclonal anti-his and anti-VEGF antibodies. The rgVEGF164 was smeared onto the dorsal area of a shaved mouse, and we noted that hair regrowth in this area was faster than in the control group. Thus, rgVEGF164 increases hair growth in mice.

The myriad essential roles of microRNAs in cardiovascular homeostasis and disease

According to the World Health Organization, cardiovascular disease accounts for approximately 30% of all deaths in the United States, and is the worldwide leading cause of morbidity and mortality. Over the last several years, microRNAs have emerged as critical regulators of physiological homeostasis in multiple organ systems, including the cardiovascular system. The focus of this review is to provide an overview of the current state of knowledge of the molecular mechanisms contributing to the multiple causes of cardiovascular disease with respect to regulation by microRNAs. A major challenge in understanding the roles of microRNAs in the pathophysiology of cardiovascular disease is that cardiovascular disease may arise from perturbations in intracellular signaling in multiple cell types including vascular smooth muscle and endothelial cells, cardiac myocytes and fibroblasts, as well as hepatocytes, pancreatic β-cells, and others. Additionally, perturbations in intracellular signaling cascades may also have profound effects on heterocellular communication via secreted cytokines and growth factors. There has been much progress in recent years to identify the microRNAs that are both dysregulated under pathological conditions, as well as the signaling pathway(s) regulated by an individual microRNA. The goal of this review is to summarize what is currently known about the mechanisms whereby microRNAs maintain cardiovascular homeostasis and to attempt to identify some key unresolved questions that require further study.

Matrix density alters zyxin phosphorylation, which limits peripheral process formation and extension in endothelial cells invading 3D collagen matrices

This study was designed to determine the optimal conditions required for known pro-angiogenic stimuli to elicit successful endothelial sprouting responses. We used an established, quantifiable model of endothelial cell (EC) sprout initiation where ECs were tested for invasion in low (1 mg/mL) and high density (5 mg/mL) 3D collagen matrices. Sphingosine 1-phosphate (S1P) alone, or S1P combined with stromal derived factor-1α (SDF) and phorbol ester (TPA), elicited robust sprouting responses. The ability of these factors to stimulate sprouting was more effective in higher density collagen matrices. S1P stimulation resulted in a significant increase in invasion distance, and with the exception of treatment groups containing phorbol ester, invasion distance was longer in 1mg/mL compared to 5mg/mL collagen matrices. Closer examination of cell morphology revealed that increasing matrix density and supplementing with SDF and TPA enhanced the formation of multicellular structures more closely resembling capillaries. TPA enhanced the frequency and size of lumen formation and correlated with a robust increase in phosphorylation of p42/p44 Erk kinase, while S1P and SDF did not. Also, a higher number of significantly longer extended processes formed in 5mg/mL compared to 1mg/mL collagen matrices. Because collagen matrices at higher density have been reported to be stiffer, we tested for changes in the mechanosensitive protein, zyxin. Interestingly, zyxin phosphorylation levels inversely correlated with matrix density, while levels of total zyxin did not change significantly. Immunofluorescence and localization studies revealed that total zyxin was distributed evenly throughout invading structures, while phosphorylated zyxin was slightly more intense in extended peripheral processes. Silencing zyxin expression increased extended process length and number of processes, while increasing zyxin levels decreased extended process length. Altogether these data indicate that ECs integrate signals from multiple exogenous factors, including changes in matrix density, to accomplish successful sprouting responses. We show here for the first time that zyxin limited the formation and extension of fine peripheral processes used by ECs for matrix interrogation, providing a molecular explanation for altered EC responses to high and low density collagen matrices.

Effects of the combination of TRC105 and bevacizumab on endothelial cell biology

Endoglin, or CD105, is a cell membrane glycoprotein that is overexpressed on proliferating endothelial cells (EC), including those found in malignancies and choroidal neovascularization. Endoglin mediates the transition from quiescent endothelium, characterized by the relatively dominant state of Smad 2/3 phosphorylation, to active angiogenesis by preferentially phosphorylating Smad 1/5/8. The monoclonal antibody TRC105 binds endoglin with high avidity and is currently being tested in phase 1b and phase 2 clinical trials. In this report, we evaluated the effects of TRC105 on primary human umbilical vascular endothelial cells (HUVEC) as a single agent and in combination with bevacizumab. As single agents, both TRC105 and bevacizumab efficiently blocked HUVEC tube formation, and the combination of both agents achieved even greater levels of inhibition. We further assessed the effects of each drug on various aspects of HUVEC function. While bevacizumab was observed to inhibit HUVEC viability in nutrient-limited medium, TRC105 had little effect on HUVEC viability, either alone or in combination with bevacizumab. Additionally, both drugs inhibited HUVEC migration and induced apoptosis. At the molecular level, TRC105 treatment of HUVEC lead to decreased Smad 1/5/8 phosphorylation in response to BMP-9, a primary ligand for endoglin. Together, these results indicate that TRC105 acts as an effective anti-angiogenic agent alone and in combination with bevacizumab.

Melatonin modulation of crosstalk among malignant epithelial, endothelial and adipose cells in breast cancer (Review)

Melatonin, the main secretory product of the pineal gland, is an oncostatic agent that reduces the growth and development of various types of tumors, particularly mammary tumors whose growth is dependent on estrogens. Previous in vivo and in vitro studies point to the hypothesis that melatonin interplays with estrogen signaling pathways at three different levels: i) an indirect mechanism, by interfering with the hypothalamic-pituitary-reproductive axis in such way that the level of plasma estrogens synthesized by the gonadal glands are downregulated; ii) a direct mechanism of the pineal gland at the cell cancer level, disrupting the activation of estradiol receptors, therefore behaving as a selective estrogen receptor modulator; and iii) by regulating the enzymes involved in the biosynthesis of estrogens in other tissues, thus behaving as a selective estrogen enzyme modulator. The intratumoral metabolism and synthesis of estrogens, as a result of the interactions of various enzymes, is more important than blood uptake to maintain mammary gland estrogen levels in menopausal females. Additionally, estrogens are considered to play an important role in the pathogenesis and development of hormone-dependent breast carcinoma. Paracrine interactions among malignant epithelial cells and proximal adipose and endothelial cells, through cytokines and growth factors produced by breast tumor cells, modulate estrogen production at the mammary tumor level and, as a consequence, the genesis and development of mammary tumors. The aim of the present review is to summarize the recent findings describing the mechanisms by which melatonin is able to modulate the crosstalk among malignant epithelial, endothelial and adipose cells in breast cancer.

Vascular endothelial growth factor promotes fibrosis resolution and repair in mice

BACKGROUND & AIMS

Vascular endothelial growth factor (VEGF)-induced angiogenesis is implicated in fibrogenesis and portal hypertension. However, the function of VEGF in fibrosis resolution has not been explored.

METHODS

We developed a cholecystojejunostomy procedure to reconstruct biliary flow after bile duct ligation in C57BL/6 mice to generate a model of fibrosis resolution. These mice were then given injections of VEGF-neutralizing (mcr84) or control antibodies, and other mice received an adenovirus that expressed mouse VEGF or a control vector. The procedure was also performed on macrophage fas-induced apoptosis mice, in which macrophages can be selectively depleted. Liver and blood samples were collected and analyzed in immunohistochemical, morphometric, vascular permeability, real-time polymerase chain reaction, and flow cytometry assays.

RESULTS

VEGF-neutralizing antibodies prevented development of fibrosis but also disrupted hepatic tissue repair and fibrosis resolution. During fibrosis resolution, VEGF inhibition impaired liver sinusoidal permeability, which was associated with reduced monocyte migration, adhesion, and infiltration of fibrotic liver. Scar-associated macrophages contributed to this process by producing the chemokine (C-X-C motif) ligand 9 (CXCL9) and matrix metalloproteinase 13. Resolution of fibrosis was impaired in macrophage fas-induced apoptosis mice but increased after overexpression of CXCL9.

CONCLUSIONS

In a mouse model of liver fibrosis resolution, VEGF promoted fibrogenesis, but was also required for hepatic tissue repair and fibrosis resolution. We observed that VEGF regulates vascular permeability, monocyte infiltration, and scar-associated macrophages function.

DNA aptamer raised against advanced glycation end products inhibits melanoma growth in nude mice

Epidemiological studies have suggested that diabetes is associated with an increased risk of cancer. However, the underlying molecular mechanism remains unclear. We investigated here whether DNA aptamer directed against advanced glycation end products (AGE-aptamer) inhibited melanoma growth in nude mice. G361 melanoma cells were injected intradermally into the upper flank of athymic nude mice. Mice received continuous intraperitoneal infusion (0.136 μg/day) of either AGE-aptamer (n=9) or Control-aptamer (n=8) by an osmotic mini pump. Tumor volume was measured at 4-day interval, and G361 melanoma was excised at day 43 after the aptamer treatment. We further examined the effects of AGE-aptamer on proliferation of AGE-exposed endothelial cells and G361 cells. AGE-aptamer significantly inhibited the in vivo-tumor growth of G361 melanoma. Immunohistochemical and western blotting analyses of G361 melanoma revealed that AGE-aptamer decreased expression levels of proliferating nuclear antigen, CD31 and Mac-3, markers of endothelial cells and macrophages, respectively. AGE-aptamer significantly decreased the number of tumor-associated vessels. AGE, receptor for AGE (RAGE) and vascular endothelial growth factor levels were also reduced in AGE-aptamer-treated G361 melanoma. AGE-aptamer inhibited the AGE-induced proliferation and tube formation of endothelial cells as well as the growth of G361 cells in vitro. The present findings suggest that AGE-aptamer could inhibit the AGE-RAGE axis in G361 melanoma and resultantly suppress the tumor growth in nude mice by blocking the angiogenesis. AGE-aptamer might be a novel therapeutic strategy for preventing the progression of malignant melanoma in diabetes.

Permeability of the blood-tumor barrier is enhanced by combining vascular endothelial growth factor with papaverine

This study aims to determine the effects of vascular endothelial growth factor (VEGF), papaverine (PA), and the combination of VEGF and PA on the permeability of the blood-tumor barrier (BTB) and to determine possible molecular mechanisms contributing to the effects. In the rat C6 glioma model, the extravasation of Evans blue (EB) through the BTB was increased significantly by VEGF and PA. VEGF-induced and PA-induced increase of EB extravasation was further increased after combining VEGF with PA infusion. Transmission electron microscopy (TEM) showed that the combination of VEGF and PA not only opened tight junctions (TJ) dramatically but increased the presence of pinocytotic vesicles of brain microvascular endothelial cells (BMECs) significantly. Meanwhile, the downregulation of the TJ-associated proteins occludin and claudin-5 and the upregulation of the caveolae structure proteins caveolin-1 and caveolin-2 caused by the combination of VEGF and PA were observed by Western blot and immunohistochemistry, which were more remarkable than those by the two strategies separately. In addition, after VEGF and PA infusion, the results of radioimmunoassay, Western blot, and enzyme-linked immunosorbent assay (ELISA) revealed a significant increase in expression levels of cGMP and protein kinase G-1 (PKG-1) and the activation of nuclear factor-κB (NF-κB) p65. This study demonstrates that combination of VEGF and PA can increase the permeability of the BTB by a paracellular pathway (downregulation of occludin and claudin-5) and a transcellular pathway (upregulation of caveolin-1 and caveolin-2) and that the cGMP/PKG/NF-κB signal pathway might be involved in the modulation process.

Effect of contrast leakage on the detection of abnormal brain tumor vasculature in high-grade glioma

Abnormal brain tumor vasculature has recently been highlighted by a dynamic susceptibility contrast (DSC) MRI processing technique. The technique uses independent component analysis (ICA) to separate arterial and venous perfusion. The overlap of the two, i.e. arterio-venous overlap or AVOL, preferentially occurs in brain tumors and predicts response to anti-angiogenic therapy. The effects of contrast agent leakage on the AVOL biomarker have yet to be established. DSC was acquired during two separate contrast boluses in ten patients undergoing clinical imaging for brain tumor diagnosis. Three components were modeled with ICA, which included the arterial and venous components. The percentage of each component as well as a third component were determined within contrast enhancing tumor and compared. AVOL within enhancing tumor was also compared between doses. The percentage of enhancing tumor classified as not arterial or venous and instead into a third component with contrast agent leakage apparent in the time-series was significantly greater for the first contrast dose compared to the second. The amount of AVOL detected within enhancing tumor was also significantly greater with the second dose compared to the first. Contrast leakage results in large signal variance classified as a separate component by the ICA algorithm. The use of a second dose mitigates the effect and allows measurement of AVOL within enhancement.

Magnetic resonance imaging identifies early effects of sunitinib treatment in human melanoma xenografts

BACKGROUND

Antiangiogenic treatment may change the tumor microenvironment and hence influence the effect of conventional therapies. The potential of diffusion weighted magnetic resonance imaging (DW-MRI) and dynamic contrast enhanced MRI (DCE-MRI) in assessing microenvironmental effects of sunitinib treatment was investigated in this preclinical study.

METHODS

Sunitinib-treated and untreated A-07 tumors were subjected to DW-MRI and DCE-MRI, and parametric images of ADC and Ktrans were produced. Microvascular density, hypoxic fraction, and necrotic fraction were assessed from immunohistochemical preparations, and tumor interstitial fluid pressure (IFP) was assessed with probe measurement.

RESULTS

Sunitinib-treated tumors showed reduced microvascular density, increased hypoxic fraction, increased necrotic fraction, increased ADC, and reduced Ktrans, but did not differ from untreated tumors in growth rate and IFP.

CONCLUSIONS

Sunitinib treatment affected the tumor microenvironment without affecting tumor size. DW-MRI and DCE-MRI were sensitive to the sunitinib-induced changes in the tumor microenvironment.

Vascular endothelial growth factor-dependent spatiotemporal dual roles of placental growth factor in modulation of angiogenesis and tumor growth

Placental growth factor (PlGF) remodels tumor vasculatures toward a normalized phenotype, which affects tumor growth, invasion and drug responses. However, the coordinative and spatiotemporal relation between PlGF and VEGF in modulation of tumor angiogenesis and vascular remodeling is less understood. Here we report that PlGF positively and negatively modulate tumor growth, angiogenesis, and vascular remodeling through a VEGF-dependent mechanism. In two independent tumor models, we show that PlGF inhibited tumor growth and angiogenesis and displayed a marked vascular remodeling effect, leading to normalized microvessels with infrequent vascular branches and increased perivascular cell coverage. Surprisingly, elimination of VEGF gene (i.e., VEGF-null) in PlGF-expressing tumors resulted in (i) accelerated tumor growth rates and angiogenesis and (ii) complete attenuation of PlGF-induced vascular normalization. Thus, PlGF positively and negatively modulates tumor growth, angiogenesis, and vascular remodeling through VEGF-dependent spatiotemporal mechanisms. Our data uncover molecular mechanisms underlying the complex interplay between PlGF and VEGF in modulation of tumor growth and angiogenesis, and have conceptual implication for antiangiogenic cancer therapy.

Endogenous oxidative stress, but not ER stress, induces hypoxia-independent VEGF120 release through PI3K-dependent pathways in 3T3-L1 adipocytes

OBJECTIVE

Expressions of vascular endothelial growth factor (VEGF) are increased in obese adipocytes and is secreted from obese adipose tissue through hypoxia-independent pathways. Therefore, we investigated the hypoxia-independent mechanism underlying increased expression and release of VEGF in obese adipocytes.

DESIGN AND METHODS

We compared signal transduction pathways regulating VEGF with those regulating monocyte chemoattractant protein-1 (MCP-1), which is increased in obese adipocytes, in an in vitro model of artificially hypertrophied 3T3-L1 adipocytes preloaded with palmitate, without the influence of hypoxia.

RESULTS

Palmitate-preloaded cells exhibited significantly enhanced oxidative stress (P < 0.01) and showed increased VEGF120 and MCP-1 release (P < 0.01, respectively), while endoplasmic reticulum (ER) stress was not induced. Increased VEGF120 release was significantly decreased with PI3K inhibitor LY294002 (P < 0.01). In addition, antioxidant N-acetyl-cysteine (NAC) markedly diminished not only VEGF120 secretion (P < 0.01) but also augmented Akt phosphorylation on Ser473 (P < 0.01). In contrast, increased MCP-1 release was suppressed with JNK inhibitor SP600125 and p38 MAPK inhibitor SB203580 (P < 0.01).

CONCLUSIONS

VEGF120 release from hypertrophied adipocytes can be enhanced through PI3K pathways activated by oxidative stress but not by ER stress, suggesting that VEGF120 secretion is regulated through oxidative stress-dependent pathways distinct from those involved in MCP-1 release through either JNK or p38 MAPK activation.

Advanced MR imaging of gliomas: an update

Recent advances in the treatment of cerebral gliomas have increased the demands on noninvasive neuroimaging for the diagnosis, therapeutic planning, tumor monitoring, and patient outcome prediction. In the meantime, improved magnetic resonance (MR) imaging techniques have shown much potentials in evaluating the key pathological features of the gliomas, including cellularity, invasiveness, mitotic activity, angiogenesis, and necrosis, hence, further shedding light on glioma grading before treatment. In this paper, an update of advanced MR imaging techniques is reviewed, and their potential roles as biomarkers of tumor grading are discussed.

Regulation of vascular endothelial growth factor by melatonin in human breast cancer cells

Melatonin exerts oncostatic effects on breast cancer by interfering with the estrogen-signaling pathways. Melatonin reduces estrogen biosynthesis in human breast cancer cells, surrounding fibroblasts and peritumoral endothelial cells by regulating cytokines that influence tumor microenvironment. This hormone also exerts antiangiogenic activity in tumoral tissue. In this work, our objective was to study the role of melatonin on the regulation of the vascular endothelial growth factor (VEGF) in breast cancer cells. To accomplish this, we cocultured human breast cancer cells (MCF-7) with human umbilical vein endothelial cells (HUVECs). VEGF added to the cultures stimulated the proliferation of HUVECs and melatonin (1 mM) counteracted this effect. Melatonin reduced VEGF production and VEGF mRNA expression in MCF-7 cells. MCF-7 cells cocultured with HUVECs stimulated the endothelial cells proliferation and increased VEGF levels in the culture media. Melatonin counteracted both stimulatory effects on HUVECs proliferation and on VEGF protein levels in the coculture media. Conditioned media from MCF-7 cells increased HUVECs proliferation, and this effect was significantly counteracted by anti-VEGF and 1 mM melatonin. All these findings suggest that melatonin may play a role in the paracrine interactions between malignant epithelial cells and proximal endothelial cells through a downregulatory action on VEGF expression in human breast cancer cells, which decrease the levels of VEGF around endothelial cells. Lower levels of VEGF could be important in reducing the number of estrogen-producing cells proximal to malignant cells as well as decreasing tumoral angiogenesis.

Tumor angiogenesis after heated lipiodol infusion via the hepatic artery in a rabbit model of VX2 liver cancer

Objectives

This study aimed to observe the changes in tumor angiogenesis after heated lipiodol (60°C) infusion via the hepatic artery in a rabbit model of VX2 liver cancer.

Materials and Methods

Twenty rabbits with VX2 hepatic tumors were randomly divided into 2 groups (10 rabbits in each group). Under anesthesia, a trans-catheter hepatic arterial infusion was performed, and lipiodol (37°C; control group) or heated lipiodol (60°C; treated group) was injected into the hepatic arteries of the animals. Then, changes in tumor angiogenesis were assessed using the following markers and methods. 1. Vascular endothelial growth factor receptor (VEGFR) and vascular endothelial growth factor (VEGF) expression levels in the tumor were assessed using western blotting and real-time quantitative polymerase chain reaction (PCR). 2. Proliferating cell nuclear antigen (PCNA) expression in the tumor was assessed through immunohistochemical staining. 3. The morphological changes in tumor vascular endothelial cells were observed using transmission electron microscopy (TEM).

Results

VEGFR and VEGF mRNA and protein expression levels were reduced in the treated group compared to the control group. PCNA protein showed reduced expression levels in the treated group compared to the control group. TEM indicated that the endothelial cell endoplasmic reticulum expanded, the chondriosome was swollen, and the endothelial cell microvilli were decreased after heated lipiodol infusion.

Conclusions

The tumor angiogenesis of rabbits with VX2 cancer was inhibited after arterial heated lipiodol infusion compared to lipiodol infusion.

Bevacizumab vs ranibizumab for neovascular age-related macular degeneration in Chinese patients

AIM

To compare the clinical efficacy of intravitreal injections of bevacizumab and ranibizumab for treating Chinese patients with neovascular age-related macular degeneration (AMD).

METHODS

Among 60 Chinese patients with exudative AMD (60 eyes), 28 received intravitreal bevacizumab injections (1.25mg) and 32 received intravitreal ranibizumab injections (0.5mg), once a month for 3 months and were followed for a total of 6 months. Monthly optical coherence tomography (OCT) was used to determine whether the patients received additional treatments during the follow-up. We compared the baseline and 6-month follow-up values of mean best-corrected visual acuity (BCVA) and central retinal thickness (CRT) in both groups of patients. We also compared the occurrence of adverse events.

RESULTS

At the 6-month follow-up, the mean BCVA (logMAR) of the bevacizumab and ranibizumab treatment groups improved from the baseline measurements of 0.72±0.23 and 0.73±0.22 to 0.47±0.14 and 0.45±0.20, respectively (P<0.05 for both groups). However, the change was not significantly different between the two groups. As evaluated by OCT, CRT decreased from 366.71±34.72µm and 352±36.9µm at baseline to 250.86±41.51µm and 243.22±41.38µm in the bevacizumab and ranibizumab groups, respectively (P<0.05 for both groups). However, the change was not significantly different between the two groups. There were no severe local adverse reactions or systemic adverse events.

CONCLUSION

Intravitreal bevacizumab and ranibizumab have equivalent effects on BCVA and CRT and appeare safe over the short-term.

Immunopathogenesis of allergic asthma: more than the th2 hypothesis

Asthma is a chronic obstructive airway disease that involves inflammation of the respiratory tract. Biological contaminants in indoor air can induce innate and adaptive immune responses and inflammation, resulting in asthma pathology. Epidemiologic surveys indicate that the prevalence of asthma is higher in developed countries than in developing countries. The prevalence of asthma in Korea has increased during the last several decades. This increase may be related to changes in housing styles, which result in increased levels of indoor biological contaminants, such as house dust mite-derived allergens and bacterial products such as endotoxin. Different types of inflammation are observed in those suffering from mild-to-moderate asthma compared to those experiencing severe asthma, involving markedly different patterns of inflammatory cells and mediators. As described in this review, these inflammatory profiles are largely determined by the involvement of different T helper cell subsets, which orchestrate the recruitment and activation of inflammatory cells. It is becoming clear that T helper cells other than Th2 cells are involved in the pathogenesis of asthma; specifically, both Th1 and Th17 cells are crucial for the development of neutrophilic inflammation in the airways, which is related to corticosteroid resistance. Development of therapeutics that suppress these immune and inflammatory cells may provide useful asthma treatments in the future.

Antiangiogenic effects of melatonin in endothelial cell cultures

Endothelial cells represent one of the critical cellular elements in tumor microenvironment playing a crucial role in the growth and progression of cancer through controlling angiogenesis. Vascular endothelial growth factor (VEGF) produced from tumor cells is essential for the expansion of breast cancer and may function in both paracrine and autocrine manners to promote proliferation, growth, survival and migration of endothelial cells. Since melatonin regulates tumor microenvironment by decreasing the secretion of VEGF by malignant epithelial cells and also regulates VEGF expression in human breast cancer cells, the aim of the present study was to investigate the anti-angiogenic activity of melatonin against the pro-angiogenic effects of breast cancer cells. In this work, we demonstrate that melatonin strongly inhibited the proliferation as well as invasion/migration of human umbilical vein endothelial cells (HUVECs). Melatonin disrupted tube formation and counteracted the VEGF-stimulated tubular network formation by HUVEC. In addition, conditioned media collected from human breast cancer cells were angiogenically active and stimulated tubule length formation and this effect was significantly counteracted by the addition of anti-VEGF or melatonin. Melatonin also disintegrated preformed capillary network. All these findings demonstrate that melatonin may play a role in the paracrine interactions that take place between malignant epithelial cells and proximal endothelial cells. Melatonin could be important in reducing endothelial cell proliferation, invasion, migration and tube formation, through a downregulatory action on VEGF. Taken together, our findings suggest that melatonin could potentially be beneficial as an antiangiogenic agent in breast cancer with possible future clinical applications.

The hexane fraction of Ardisia crispa Thunb. A. DC. roots inhibits inflammation-induced angiogenesis

BACKGROUND

Ardisia crispa (Myrsinaceae) is used in traditional Malay medicine to treat various ailments associated with inflammation, including rheumatism. The plant's hexane fraction was previously shown to inhibit several diseases associated with inflammation. As there is a strong correlation between inflammation and angiogenesis, we conducted the present study to investigate the anti-angiogenic effects of the plant's roots in animal models of inflammation-induced angiogenesis.

METHODS

We first performed phytochemical screening and high-performance liquid chromatography (HPLC) fingerprinting of the hexane fraction of Ardisia crispa roots ethanolic extract (ACRH) and its quinone-rich fraction (QRF). The anti-inflammatory properties of ACRH and QRF were tested using the Miles vascular permeability assay and the murine air pouch granuloma model following oral administration at various doses.

RESULTS

Preliminary phytochemical screening of ACRH revealed the presence of flavonoids, triterpenes, and tannins. The QRF was separated from ACRH (38.38% w/w) by column chromatography, and was isolated to yield a benzoquinonoid compound. The ACRH and QRF were quantified by HPLC. The LD(50) value of ACRH was 617.02 mg/kg. In the Miles vascular permeability assay, the lowest dose of ACRH (10 mg/kg) and all doses of QRF significantly reduced vascular endothelial growth factor (VEGF)-induced hyperpermeability, when compared with the vehicle control. In the murine air pouch granuloma model, ACRH and QRF both displayed significant and dose-dependent anti-inflammatory effects, without granuloma weight. ACRH and QRF significantly reduced the vascular index, but not granuloma tissue weight.

CONCLUSIONS

In conclusion, both ACRH and QRF showed potential anti-inflammatory properties in a model of inflammation-induced angiogenesis model, demonstrating their potential anti-angiogenic properties.

sVEGF R1 and Tie-2 levels during chemotherapy of lung cancer patients

Angiogenesis plays important role in tumor growth and development. Protein ligands and their receptor tyrosine kinases are crucial in tumor related angiogenesis. Ligand/receptor systems such as vascular endothelial growth factor (VEGF), and tyrosine kinase with immunoglobulin-like and epidermal growth factor homology domains (Tie) family play important role in this phenomenon. The aim of this study was to evaluate the concentration of soluble receptor of VEGF (sVEGF R1) and Tie-2 domain in plasma of lung cancer patients before and after chemotherapy. Forty four lung cancer patients, 11 with small lung cancer (SCLC), 5 females and 6 males (mean age 60.2, range 39-72 years), and 33 patients with non-small cell lung cancer (N-SCLC), 6 females and 27 males (mean age 61.9, range 42-78 years) received four courses of chemotherapy. Control group consisted of 44 patients with COPD, 4 females and 40 males (mean age 37.1, 18-60 years). In all cases clinical partial response was achieved. Both sVEGF R1 and Tie-2 concentrations were elevated in cancer group before treatment compared with control: sVEGF (pg/ml): 60.7 and 66.2 vs. 48.8 and Tie-2 (ng/ml): 37.3 and 37.5 vs. 30.7 in SCLC and N-SCLC vs. C, respectively. Treatment decreased sVEGF R1 (pg/ml): 66.7 vs. 11.6 (p < 0.05) and 66.2 vs. 14.39 (p < 0.001), and Tie-2 (ng/ml): 37.3 vs. 26.3 (p < 0.05) and 37.5 vs. 25.7 (p < 0.001) in SCLC and N-SCLC, respectively. We conclude that VEGF R1and Tie-2 receptors may play important role in lung cancer development and their receptor concentrations may reflect the patients' response to treatment.

Reproducibility and biological basis of in vivo T(2)* magnetic resonance imaging of liver metastasis of colorectal cancer

In this study, the reproducibility of T2* MR imaging in colorectal liver metastases was assessed and T2* values were correlated with the expression of the hypoxia-related markers GLUT-1 and CA-IX as well as the relative vascular area, and the vessel density in resected tumors. The reproducibility of T2* was analyzed in 18 patients with in total 22 colorectal liver metastases using the Bland and Altman method for the 16th, 50th, and 84th percentile values. Immunohistochemical staining was performed on 17 resected tumors obtained from 16 patients. The median T2* of all liver metastases was 25.0 ± 5.6 ms vs. 23.0 ± 4.1 ms (median ± st.dev.) in normal liver. The coefficient of repeatability was 11.2 ms and the limits of agreement were -13.2 ms and 9.1 ms for median T2* values. On average, T2* showed fair reproducibility. No correlations between T2* values, hypoxia- and vascularity-related markers were observed.

Imaging biomarkers of angiogenesis and the microvascular environment in cerebral tumours

Conventional contrast-enhanced CT and MRI are now in routine clinical use for the diagnosis, treatment and monitoring of diseases in the brain. The presence of contrast enhancement is a proxy for the pathological changes that occur in the normally highly regulated brain vasculature and blood-brain barrier. With recognition of the limitations of these techniques, and a greater appreciation for the nuanced mechanisms of microvascular change in a variety of pathological processes, novel techniques are under investigation for their utility in further interrogating the microvasculature of the brain. This is particularly important in tumours, where the reliance on angiogenesis (new vessel formation) is crucial for tumour growth, and the resulting microvascular configuration and derangement has profound implications for diagnosis, treatment and monitoring. In addition, novel therapeutic approaches that seek to directly modify the microvasculature require more sensitive and specific biological markers of baseline tumour behaviour and response. The currently used imaging biomarkers of angiogenesis and brain tumour microvascular environment are reviewed.

Three-dimensional culture models of mammary gland

The mammary gland is a complex tissue comprised of a branching network of ducts embedded within an adipocyte-rich stroma. The ductal epithelium is a bi-layer of luminal and myoepithelial cells, the latter being in contact with a basement membrane. During pregnancy, tertiary branching occurs and lobuloalveolar structures, which produce milk during lactation, form in response to hormonal and cytokine signals. Postlactational regression is characterized by extensive cell death and tissue remodeling. These complex developmental events have been difficult to mimic in cell culture although many useful culture models exist. Recently, considerable advances in three-dimensional modelling of the mammary gland have been made with the use of collagen and other biomaterials for the study of branching morphogenesis and tumorigenesis, techniques which may enable rapid advances in our understanding of both basic biology and the study of cancer therapeutics.

An imaging-based stochastic model for simulation of tumour vasculature

A mathematical model which reconstructs the structure of existing vasculature using patient-specific anatomical, functional and molecular imaging as input was developed. The vessel structure is modelled according to empirical vascular parameters, such as the mean vessel branching angle. The model is calibrated such that the resultant oxygen map modelled from the simulated microvasculature stochastically matches the input oxygen map to a high degree of accuracy (R(2) ≈ 1). The calibrated model was successfully applied to preclinical imaging data. Starting from the anatomical vasculature image (obtained from contrast-enhanced computed tomography), a representative map of the complete vasculature was stochastically simulated as determined by the oxygen map (obtained from hypoxia [(64)Cu]Cu-ATSM positron emission tomography). The simulated microscopic vasculature and the calculated oxygenation map successfully represent the imaged hypoxia distribution (R(2) = 0.94). The model elicits the parameters required to simulate vasculature consistent with imaging and provides a key mathematical relationship relating the vessel volume to the tissue oxygen tension. Apart from providing an excellent framework for visualizing the imaging gap between the microscopic and macroscopic imagings, the model has the potential to be extended as a tool to study the dynamics between the tumour and the vasculature in a patient-specific manner and has an application in the simulation of anti-angiogenic therapies.

Emerging treatment options for management of malignant ascites in patients with ovarian cancer

Malignant ascites affects approximately 10% of patients with recurrent epithelial ovarian cancer and is associated with troublesome symptoms, including abdominal pressure and distension, dyspnea, bloating, pelvic pain, and bowel/bladder dysfunction. To date, no effective therapy has been identified for the treatment of malignant ascites in patients with recurrent, advanced ovarian cancer. In this article, we discuss currently existing options for the treatment of ascites associated with ovarian cancer, and review the literature as it pertains to novel, targeted therapies. Specifically, preclinical and clinical trials exploring the use of the antiangiogenic agents, bevacizumab and vascular endothelial growth factor-trap, as well as the nonangiogenic agent, catumaxomab, will be reviewed. Despite current limitations in treatment, knowledge regarding management options in the palliation of ascites is critical to practicing physicians. Ultimately, as with all novel therapies, symptom relief and treatment goals must be weighed against patient discomfort and potentially significant adverse events.

Angiogenic alterations associated with circulating neoplastic DNA in ovarian carcinoma

OBJECTIVES

Forty percent of women with ovarian carcinoma have circulating free neoplastic DNA identified in plasma. Angiogenesis is critical in neoplastic growth and metastasis. We sought to determine whether circulating neoplastic DNA results from alterations in the balance of angiogenesis activators and inhibitors.

METHODS

Sixty patients with invasive ovarian carcinomas with somatic TP53 mutations that had been characterized for circulating neoplastic DNA had carcinoma analyzed for microvessel density using immunohistochemistry with CD31 and for the expression of VEGF, ANGPT1, ANGPT2, PTGS2, PLAU, THBS1, CSF1, PIK3CA, HIF1A, IL8, MMP2, and MMP9 message by real-time quantitative polymerase chain reaction. The expression of each gene was calculated relative to GAPDH expression for each neoplasm. Patient plasma had been tested for circulating neoplastic DNA using a ligase detection reaction.

RESULTS

MMP2 expression was significantly correlated with free plasma neoplastic DNA (P = .007). Microvessel density was not correlated with plasma neoplastic DNA or BRCA1/2 mutation status. The expression pattern of other angiogenic factors did not correlate with plasma neoplastic DNA but correlated with each other. BRCA1/2 mutated carcinomas had significantly different expression profiles of angiogenesis activators and inhibitors in comparison to sporadic carcinomas.

CONCLUSIONS

MMP2 expression is associated with the presence of circulating neoplastic DNA in women with ovarian carcinoma. These data are consistent with the proinvasive properties of MMP2 and suggest that the presence of circulating neoplastic DNA indicates a more aggressive malignant phenotype. Carcinomas with germ line BRCA1/2 mutations had a lower angiogenic profile than those without mutations.

Effect of the combination of a cyclooxygenase-1 selective inhibitor and taxol on proliferation, apoptosis and angiogenesis of ovarian cancer in vivo

This study was designed to investigate the effects of a cyclooxygenase (COX)-1 inhibitor, SC-560, administered in combination with taxol, on the molecular mechanisms of antitumor efficacy in a SKOV-3 human ovarian carcinoma cell xenograft-bearing mouse model. The mice were treated with 6 mg/kg/day SC-560 by gavage twice every other day and 20 mg/kg taxol by intraperitoneal injection once a week for three weeks. Microvessel density (MVD) and vascular endothelial growth factor (VEGF) mRNA levels of ovarian cancer were detected in the tumor tissues using immunohistochemistry and reverse transcription-polymerase chain reaction (RT-PCR), respectively. The index of proliferating and apoptotic cells in the tumor tissues was determined by staining for Ki-67 and using the terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) method, respectively. On day 7 after the end of administration, the tumor volume of mice in the combination group was reduced by 55.35% compared with that of the control mice, and the difference was statistically significant (P<0.05). In the combination group, the expression of VEGF, MVD and the cell proliferation index were inhibited significantly, while the apoptotic index was notably increased (all P<0.01, compared with the control group). Our results indicate that the molecular mechanisms of the antitumor efficacy of SC-560 combined with taxol therapy may act in part by inhibiting tumor angiogenesis, reducing cell proliferation and inducing cell apoptosis.

Prognostic significance of vascular endothelial growth factor serum determination in women with ovarian cancer

Introduction. We performed a review of the literature to elucidate the potential prognostic significance of serum vascular endothelial growth factor (sVEGF) levels in ovarian cancer. Methods. Eligible studies in English and Italian were identified in MEDLINE/PubMed from VEGF discovery to October 2011. All studies evaluating: (i) sVEGF levels before any surgical and chemotherapeutic treatment; (ii) the association between sVEGF levels and the established prognostic variables; (iii) the value of sVEGF levels in predicting patients' outcomes, were selected for this review. Results. The search resulted in 758 titles. Nine studies met the inclusion criteria. A statistically significant association between the level of sVEGF and FIGO stage, tumour grade, residual tumour size, lymph node involvement, and presence of ascites was found in at least one study. sVEGF, in comparison with the established prognostic factors, appears to be the best prognostic marker for overall survival, since it stands out as an independent prognostic factor in most of the studies considered. Moreover, sVEGF levels were shown to be independent prognostic factors by 2 out of the 3 studies that considered DFS as an end point. Conclusion. High levels of sVEGF identify a subgroup of patients with higher risk of death and/or recurrence. These patients should be eligible for individually tailored therapeutic interventions.

Revealing the role of phospholipase Cβ3 in the regulation of VEGF-induced vascular permeability

VEGF induces vascular permeability (VP) in ischemic diseases and cancer, leading to many pathophysiological consequences. The molecular mechanisms by which VEGF acts to induce hyperpermeability are poorly understood and in vivo models that easily facilitate real-time, genetic studies of VP do not exist. In the present study, we report a heat-inducible VEGF transgenic zebrafish (Danio rerio) model through which VP can be monitored in real time. Using this approach with morpholino-mediated gene knock-down and knockout mice, we describe a novel role of phospholipase Cβ3 as a negative regulator of VEGF-mediated VP by regulating intracellular Ca2+ release. Our results suggest an important effect of PLCβ3 on VP and provide a new model with which to identify genetic regulators of VP crucial to several disease processes.

Intratumoral expression profiling of genes involved in angiogenesis in colorectal cancer patients treated with chemotherapy plus the VEGFR inhibitor PTK787/ZK 222584 (vatalanib)

The phase III CONFIRM clinical trials demonstrated that metastatic colorectal cancer patients with elevated serum lactate dehydrogenase (LDH) had improved outcome when the vascular endothelial growth factor receptor (VEGFR) inhibitor PTK/ZK (Vatalanib) was added to FOLFOX4 chemotherapy. We investigated the hypothesis that high intratumoral expression of genes regulated by hypoxia-inducible factor-1 alpha (HIF1α), namely LDHA, glucose transporter-1 (GLUT-1), VEGFA, VEGFR1, and VEGFR2, were predictive of outcome in CONFIRM-1. Tumor tissue was isolated by laser-capture microdissection from 85 CONFIRM-1 tumor specimens; FOLFOX4/placebo n=42, FOLFOX4/PTK/ZK n=43. Gene expression was analyzed using quantitative RT-PCR. In univariate analyses, elevated mRNA expression of LDHA, GLUT-1, and VEGFR1 were associated with response to FOLFOX4/PTK/ZK. In univariate and multivariate analyses, elevated LDHA and VEGFR1 mRNA levels were associated with improved progression-free survival in FOLFOX4/PTK/ZK patients. Furthermore, increased HIF1α and VEGFR2 mRNA levels were associated with decreased survival in FOLFOX/placebo patients but not in patients who received FOLFOX4/PTK/ZK. These are the first data suggesting intratumoral mRNA expression of genes involved in angiogenesis/HIF pathway may predict outcome to VEGFR-inhibitors. Biomarkers that assist in directing VEGFR-inhibitors toward patients with an increased likelihood of benefit will improve the cost-effectiveness of these promising agents.

The effect of anodized implants coated with combined rhBMP-2 and recombinant human vascular endothelial growth factors on vertical bone regeneration in the marginal portion of the peri-implant

OBJECTIVES

The aim of this study was to evaluate the effect of anodized implants coated with combined rhBMP-2 and recombinant human vascular endothelial growth factors (rhVEGFs) on vertical bone regeneration in the marginal portion of the peri-implant.

STUDY DESIGN

Supra-alveolar defects were created in 3 male beagle dogs. Each animal received 8 implants that were either coated with a single growth factor (rhBMP-2) or combined growth factors (rhBMP-2 + rhVEGF), or an anodized implant (the control group). The amount of the vertical bone regeneration, the bone-implant contact, and the intrathread bone density were investigated using histomorphometric analysis at 8 weeks.

RESULTS

The bone morphogenetic protein (BMP) group and the BMP-VEGF group showed vertical alveolar bone regeneration and enhanced bone-implant contact in the microthread compared with the control group (P < .05).

CONCLUSIONS

Anodized implants coated with rhBMP-2 and rhBMP - 2 + rhVEGF can induce vertical alveolar bone regeneration, but the combined effect of rhBMP-2 and rhVEGF was not verified.

Anti-cancer activities of tea epigallocatechin-3-gallate in breast cancer patients under radiotherapy

The purpose of this study was to test the hypothesis that administration of epigallocatechin-3-gallate (EGCG), a polyphenol present in abundance in widely consumed tea, inhibits cell proliferation, invasion, and angiogenesis in breast cancer patients. EGCG in 400 mg capsules was orally administered three times daily to breast cancer patients undergoing treatment with radiotherapy. Parameters related to cell proliferation, invasion, and angiogenesis were analyzed while blood samples were collected at different time points to determine efficacy of the EGCG treatment. Compared to patients who received radiotherapy alone, those given radiotherapy plus EGCG for an extended time period (two to eight weeks) showed significantly lower serum levels of vascular endothelial growth factor (VEGF), hepatocyte growth factor (HGF), and reduced activation of metalloproteinase-9 and metalloproteinase-2 (MMP9/MMP2). Addition of sera obtained from patients treated with combination of radiotherapy and EGCG feeding for 2-8 weeks to in vitro cultures of highly-metastatic human MDA-MB-231 breast cancer cells resulted in the following significant changes: (1) suppression of cell proliferation and invasion; (2) arrest of cell cycles at the G0/G1 phase; (3) reduction of activation of MMP9/MMP2, expressions of Bcl-2/Bax, c-Met receptor, NF-κB, and the phosphorylation of Akt. MDA-MB-231 cells exposed to 5-10 µM EGCG also showed significant augmentation of the apoptosis inducing effects of γ-radiation, concomitant with reduced NF-κB protein level and AKT phosphorylation. These results provide hitherto unreported evidence that EGCG potentiated efficacy of radiotherapy in breast cancer patients, and raise the possibility that this tea polyphenol has potential to be a therapeutic adjuvant against human metastatic breast cancer.

Diagnostic accuracy of vascular endothelial growth factor for malignant pleural effusion: A meta-analysis

Since the diagnostic accuracy of conventional examinations for malignant pleural effusion (MPE) is limited, a number of studies have investigated the utility of pleural vascular endothelial growth factor (VEGF) in the diagnosis of MPE. The present meta-analysis aimed to determine the overall accuracy of a VEGF test in the diagnosis of MPE. A systematic review of studies published in English was conducted and the data concerning the accuracy of pleural VEGF assays in the diagnosis of MPE were pooled with random effects models. The overall test performance was summarized using receiver operating characteristic curves. Ten studies, based on 1,025 patients, met the inclusion criteria for the meta-analysis and the summary estimates for VEGF in the diagnosis of MPE were: sensitivity 0.75 [95% confidence interval (CI), 0.72-0.79], specificity 0.72 (95% CI, 0.68-0.76), positive likelihood ratio 2.94 (95% CI, 1.97-4.41), negative likelihood ratio 0.38 (95% CI, 0.27-0.51) and diagnostic odds ratio 9.05 (95% CI, 4.60-17.80). The summary receiver operating characteristic curve indicated that the maximum joint sensitivity and specificity was 0.75; the area under the curve was 0.82. Our findings suggest that the determination of pleural VEGF may improve the accuracy of MPE diagnosis, while the results of VEGF assays should be interpreted in parallel with conventional test results and other clinical findings.

Ellagic acid, a phenolic compound, exerts anti-angiogenesis effects via VEGFR-2 signaling pathway in breast cancer

Anti-angiogenesis targeting VEGFR-2 has been considered as an important strategy for cancer therapy. Ellagic acid is a naturally existing polyphenol widely found in fruits and vegetables. It was reported that ellagic acid interfered with some angiogenesis-dependent pathologies. Yet the mechanisms involved were not fully understood. Thus, we analyzed its anti-angiogenesis effects and mechanisms on human breast cancer utilizing in-vitro and in-vivo methodologies. The in-silico analysis was also carried out to further analyze the structure-based interaction between ellagic acid and VEGFR-2. We found that ellagic acid significantly inhibited a series of VEGF-induced angiogenesis processes including proliferation, migration, and tube formation of endothelial cells. Besides, it directly inhibited VEGFR-2 tyrosine kinase activity and its downstream signaling pathways including MAPK and PI3K/Akt in endothelial cells. Ellagic acid also obviously inhibited neo-vessel formation in chick chorioallantoic membrane and sprouts formation of chicken aorta. Breast cancer xenografts study also revealed that ellagic acid significantly inhibited MDA-MB-231 cancer growth and P-VEGFR2 expression. Molecular docking simulation indicated that ellagic acid could form hydrogen bonds and aromatic interactions within the ATP-binding region of the VEGFR-2 kinase unit. Taken together, ellagic acid could exert anti-angiogenesis effects via VEGFR-2 signaling pathway in breast cancer.

Vascular endothelial growth factor in malignant and benign pericardial effusion

BACKGROUND

The pathogenetic role of vascular endothelial growth factor (VEGF) in malignant pericardial effusion and diagnostic value of pericardial VEGF levels to discriminate malignant from benign pericardial effusions are uncertain.

HYPOTHESIS

We hypothesized that pericardial VEGF levels would be higher in malignant than benign pericardial effusion and that VEGF would be a useful marker for the diagnosis of malignant pericardial effusion.

METHODS

Using an enzyme-linked immunosorbent assay, we assessed pericardial and serum VEGF levels in patients with malignant pericardial effusion (n = 19), in patients with nonmalignant pericardial effusion (n = 30), and for control, in patients without pericardial disease (n = 26).

RESULTS

Vascular endothelial growth factor pericardial levels in malignant pericardial effusion (13 593.8 ± 22 410.24 pg/mL) were significantly higher compared with VEGF in nonmalignant effusion (610.63 ± 1289.08 pg/mL; P = 0.001) and pericardial fluid (5.5 ± 15.97 pg/mL; P < 0.001). In serum, VEGF was significantly higher in patients with nonmalignant pericardial effusion (188.3 ± 240.35 pg/mL) compared with patients with malignant pericardial effusion (67.52 ± 125.77 pg/mL; P = 0.024) and coronary artery disease patients (29.13 ± 76.26 pg/mL; P < 0.001). Pericardial VEGF levels were significantly higher than matched serum levels only in patients with malignant pericardial effusion (P = 0.023). Pericardial VEGF levels ≥2385 pg/mL had 75% sensitivity and 90% specificity for the recognition of malignant pericardial effusion in patients with breast or lung cancer.

CONCLUSIONS

Vascular endothelial growth factor levels in pericardial effusion are markedly elevated in patients with malignant pericardial effusion, indicating abundant local release within the pericardial cavity. It is thus possible that VEGF participates in the pathogenesis of malignant pericardial effusion. Measurement of VEGF in pericardial effusion offers potential as a diagnostic tool to discriminate malignant from benign effusions in patients with breast or lung cancer.

Synthesis and structure-activity relationships of (aryloxy)quinazoline ureas as novel, potent, and selective vascular endothelial growth factor receptor-2 inhibitors

In our continuing search for medicinal agents to treat proliferative diseases, quinazoline derivatives were synthesized and evaluated pharmacologically as epithelial growth factor receptor and vascular endothelial growth factor receptor 2 (VEGFR-2) tyrosine kinase inhibitors. A quantitative structure-activity relationship analysis was conducted to rationalize the structure-activity relationship and to predict how similar the inhibitor-binding profiles of two protein kinases are likely to be on the basis of the docking of lead coumpounds into the ATP-binding site. This model was used to direct the synthesis of new compounds. A series of N-(aromatic)-N'-{4-[(6,7-dimethoxyquinazolin-4-yl)oxy]phenyl}urea were identified as potent and selective inhibitors of the tyrosine kinase activity of VEGFR-2 (fetal liver kinase 1, kinase insert domain-containing receptor). An efficient route was developed that enabled the synthesis of a wide variety of analogues with substitution on several positions of the template. Substitution of diarylurea, competitive with ATP, afforded several analogues with low nanomolar inhibition of enzymatic activity of VEGFR-2. In this paper, we describe the synthesis, structure-activity relationships, and pharmacological characterization of the series.