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Sample records for factor receptor-2 vegfr-2

  1. Morpholino-Mediated Isoform Modulation of Vascular Endothelial Growth Factor Receptor-2 (VEGFR2) Reduces Colon Cancer Xenograft Growth

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    Stagg, Brian C., E-mail: briancstagg@gmail.com; Uehara, Hironori; Lambert, Nathan; Rai, Ruju; Gupta, Isha; Radmall, Bryce; Bates, Taylor; Ambati, Balamurali K. [John A Moran Eye Center, University of Utah, Salt Lake City, UT, 65 Mario Capecchi Drive, Salt Lake City, UT 84132 (United States)

    2014-11-26

    Angiogenesis plays a key role in tumor growth. Vascular endothelial growth factor (VEGF) is a pro-angiogenic that is involved in tumor angiogenesis. When VEGF binds to membrane-bound vascular endothelial growth factor receptor 2 (mVEGFR2), it promotes angiogenesis. Through alternative polyadenylation, VEGFR2 is also expressed in a soluble form (sVEGFR2). sVEGFR2 sequesters VEGF and is therefore anti-angiogenic. The aim of this study was to show that treatment with a previously developed and reported antisense morpholino oligomer that shifts expression from mVEGFR2 to sVEGFR2 would lead to reduced tumor vascularization and growth in a murine colon cancer xenograft model. Xenografts were generated by implanting human HCT-116 colon cancer cells into the flanks of NMRI nu/nu mice. Treatment with the therapeutic morpholino reduced both tumor growth and tumor vascularization. Because the HCT-116 cells used for the experiments did not express VEGFR2 and because the treatment morpholino targeted mouse rather than human VEGFR2, it is likely that treatment morpholino was acting on the mouse endothelial cells rather than directly on the tumor cells.

  2. Screening of the transcriptional regulatory regions of vascular endothelial growth factor receptor 2 (VEGFR2 in amyotrophic lateral sclerosis

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    Hartley Judith

    2007-04-01

    Full Text Available Abstract Background Vascular endothelial growth factor (VEGF has neurotrophic activity which is mediated by its main agonist receptor, VEGFR2. Dysregulation of VEGF causes motor neurone degeneration in a mouse model of amyotrophic lateral sclerosis (ALS, and expression of VEGFR2 is reduced in motor neurones and spinal cord of patients with ALS. Methods We have screened the promoter region and 4 exonic regions of functional significance of the VEGFR2 gene in a UK population of patients with ALS, for mutations and polymorphisms that may affect expression or function of this VEGF receptor. Results No mutations were identified in the VEGFR2 gene. We found no association between polymorphisms in the regulatory regions of the VEGFR2 gene and ALS. Conclusion Mechanisms other than genetic variation may downregulate expression or function of the VEGFR2 receptor in patients with ALS.

  3. Fibroblast Growth Factor Receptor 1 (FGFR1), Partly Related to Vascular Endothelial Growth Factor Receptor 2 (VEGFR2) and Microvessel Density, is an Independent Prognostic Factor for Non-Small Cell Lung Cancer

    Science.gov (United States)

    Pu, Dan; Liu, Jiewei; Li, Zhixi; Zhu, Jiang; Hou, Mei

    2017-01-01

    Background This study aimed to explore the correlation between FGFR1 and clinical features, including survival analysis and the promotion of angiogenesis by fibroblast growth factor receptor 1 (FGFR1) and vascular endothelial growth factor receptor 2 (VEGFR2). FGFR1 gene amplification has been found in non-small cell lung cancer (NSCLC). However, the prognostic value of FGFR1 and the correlation between FGFR1 and clinical features are still controversial. Material/Methods A total of 92 patients with NSCLC who underwent R0 resection between July 2006 and July 2008 were enrolled in the study. The expression of FGFR1, VEGFR2, and CD34 was detected by immunohistochemistry. The correlations between the aforementioned markers and the patients’ clinical features were analyzed by the chi-square test. The impact factors of prognosis were evaluated by Cox regression analyses. Results The expression ratios of FGFR1 and VEGFR2 were 26.1% and 43.4%, respectively. The intensity of FGFR1 expression was related to VEGFR2 and histopathology. To some extent, the average microvessel density (MVD) had correlation to the expression of FGFR1 and VGEFR2. The pathological stages III–IV and high expression of FGFR1 were found to be independent prognostic factors. Conclusions The expression intensity of FGFR1 and VEGFR2 was associated with MVD, and the expression of FGFR1 is one of the independent prognostic indicators for NSCLC. PMID:28088809

  4. A phospholipid-PEG2000 conjugate of a vascular endothelial growth factor receptor 2 (VEGFR2)-targeting heterodimer peptide for contrast-enhanced ultrasound imaging of angiogenesis.

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    Pillai, R; Marinelli, E R; Fan, H; Nanjappan, P; Song, B; von Wronski, M A; Cherkaoui, S; Tardy, I; Pochon, S; Schneider, M; Nunn, A D; Swenson, R E

    2010-03-17

    The transition of a targeted ultrasound contrast agent from animal imaging to testing in clinical studies requires considerable chemical development. The nature of the construct changes from an agent that is chemically attached to microbubbles to one where the targeting group is coupled to a phospholipid, for direct incorporation to the bubble surface. We provide an efficient method to attach a heterodimeric peptide to a pegylated phospholipid and show that the resulting construct retains nanomolar affinity for its target, vascular endothelial growth factor receptor 2 (VEGFR2), for both the human (kinase insert domain-containing receptor - KDR) and the mouse (fetal liver kinase 1 - Flk-1) receptors. The purified phospholipid-PEG-peptide isolated from TFA-based eluents is not stable with respect to hydrolysis of the fatty ester moieties. This leads to the time-dependent formation of the lysophospholipid and the phosphoglycerylamide derived from the degradation of the product. Purification of the product using neutral eluent systems provides a stable product. Methods to prepare the lysophospholipid (hydrolysis product) are also included. Biacore binding data demonstrated the retention of binding of the lipopeptide to the KDR receptor. The phospholipid-PEG2000-peptide is smoothly incorporated into gas-filled microbubbles and provides imaging of angiogenesis in a rat tumor model.

  5. Soluble vascular endothelial growth factor receptors 2 (sVEGFR-2) and 3 (sVEGFR-3) and breast cancer risk in the Swedish Mammography Cohort.

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    Harris, Holly; Wolk, Alicja; Larsson, Anders; Vasson, Marie-Paule; Basu, Samar

    2016-01-01

    Vascular endothelial growth factor (VEGF) is a signalling protein that has been established as a contributor to tumor angiogenesis, and expression of VEGF and its soluble receptors (sVEGFR2 and sVEGFR3) have been demonstrated in breast cancer cells. However, no prospective studies have examined the association between prediagnostic sVEGFR levels and breast cancer risk. We conducted a prospective case-control study nested within the Swedish Mammography Cohort examining the association between sVEGFR2 and 3 levels and breast cancer risk. The analysis included 69 incident breast cancer cases diagnosed after blood collection and 719 controls. Logistic regression models were used to calculate odds ratios and 95% confidence intervals. After adjustment for breast cancer risk factors, sVEGFR2 levels were associated with breast cancer risk (OR=1.28; 95% CI=1.06-1.56 per 1000 ng/L increase in concentration) while sVEGFR3 levels were not related to such risk (OR=1.00; 95% CI=0.93-1.07). Our results suggest that sVEGFR2 levels may be positively associated with breast cancer risk, however future studies with larger case groups are necessary to confirm this association.

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

    DEFF Research Database (Denmark)

    Hempel, Casper; Hoyer, Nils; Staalsø, Trine

    2014-01-01

    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 vi...

  7. Relationship between Expression of beta-catenin and VEGFs(VEGFA,VEGF-C),VEGF Receptors-2(VEGFR-2)in Medulloblastoma

    Institute of Scientific and Technical Information of China (English)

    ZHANG Hong-mei; ZHANG Xiong; LI Yu; MI Can

    2008-01-01

    Objective:To investigate the expression of beta-catenin and VEGFs(VEGF-A,VEGF-C)and VEGF receptor-2(VEGFR-2)protein in medulloblastoma.Methods:Immunohistochemical staining with SP method Was conducted to determine the expression of beta-eatenin and VEGFs(VEGF-A,VEGF-C)and VEGFR-2 in 33 cases of medulloblastoma and 10 normal cerebellar tissues. Results:The expression rate of beta-catenin,and VEGFs (VEGF-A,VEGF-C)and VEGFR-2 in medulloblastoma were significantly higher than that in normal tissue.A significant positive correlation was found between beta-catenin and VEGFs(VEGF-A,VEGF-C)and VEGFR-2 protein in medulloblastoma. Conclusion:There was a correlation between beta-catenin and VEGFs(VEGF-A,VEGF-C)and VEGFR-2 in medulloblastoma,which may play a role in the pathogenesis and development of medulloblastoma.

  8. Soluble Expression and Purification of the Catalytic Domain of Human Vascular Endothelial Growth Factor Receptor 2 in Escherichia coli.

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    Wei, Jia; Cao, Xiaodan; Zhou, Shengmin; Chen, Chao; Yu, Haijun; Zhou, Yao; Wang, Ping

    2015-08-01

    Vascular endothelial growth factor (VEGF) plays a key role in angiogenesis through binding to its specific receptors, which mainly occurs to VEGF receptor 2 (VEGFR-2), a kinase insert domain-containing receptor. Therefore, the disruption of VEGFR-2 signaling provides a promising therapeutic approach for the treatment of cancer by inhibiting abnormal or tumorinduced angiogenesis. To explore this potential, we expressed the catalytic domain of VEGFR- 2 (VEGFR-2-CD) as a soluble active kinase in Escherichia coli. The recombinant protein was purified and the VEGFR-2-CD activity was investigated. The obtained VEGFR-2-CD showed autophosphorylation activity and phosphate transfer activity comparable to the commercial enzyme. Furthermore, the IC50 value of known VEGFR-2 inhibitor was determined using the purified VEGFR-2-CD. These results indicated a possibility for functional and economical VEGFR-2-CD expression in E. coli to use for inhibitor screening.

  9. Site-Specific N-Glycosylation of Endothelial Cell Receptor Tyrosine Kinase VEGFR-2.

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    Chandler, Kevin Brown; Leon, Deborah R; Meyer, Rosana D; Rahimi, Nader; Costello, Catherine E

    2017-02-03

    Vascular endothelial growth factor receptor-2 (VEGFR-2) is an important receptor tyrosine kinase (RTK) that plays critical roles in both physiologic and pathologic angiogenesis. The extracellular domain of VEGFR-2 is composed of seven immunoglobulin-like domains, each with multiple potential N-glycosylation sites (sequons). N-glycosylation plays a central role in RTK ligand binding, trafficking, and stability. However, despite its importance, the functional role of N-glycosylation of VEGFR-2 remains poorly understood. The objectives of the present study were to characterize N-glycosylation sites in VEGFR-2 via enzymatic release of the glycans and concomitant incorporation of (18)O into formerly N-glycosylated sites followed by tandem mass spectrometry (MS/MS) analysis to determine N-glycosylation site occupancy and the site-specific N-glycan heterogeneity of VEGFR-2 glycopeptides. The data demonstrated that all seven VEGFR-2 immunoglobulin-like domains have at least one occupied N-glycosylation site. MS/MS analyses of glycopeptides and deamidated, deglycosylated (PNGase F-treated) peptides from ectopically expressed VEGFR-2 in porcine aortic endothelial (PAE) cells identified N-glycans at the majority of the 17 potential N-glycosylation sites on VEGFR-2 in a site-specific manner. The data presented here provide direct evidence for site-specific, heterogeneous N-glycosylation and N-glycosylation site occupancy on VEGFR-2. The study has important implications for the therapeutic targeting of VEGFR-2, ligand binding, trafficking, and signaling.

  10. MET Suppresses Epithelial VEGFR2 via Intracrine VEGF-induced Endoplasmic Reticulum-associated Degradation

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    Tom T. Chen

    2015-05-01

    Full Text Available Hepatocyte growth factor (HGF and vascular endothelial growth factor (VEGF drive cancer through their respective receptors, MET and VEGF receptor 2 (VEGFR2. VEGFR2 inhibits MET by promoting MET dephosphorylation. However, whether MET conversely regulates VEGFR2 remains unknown. Here we show that MET suppresses VEGFR2 protein by inducing its endoplasmic-reticulum-associated degradation (ERAD, via intracrine VEGF action. HGF–MET signaling in epithelial cancer cells promoted VEGF biosynthesis through PI3-kinase. In turn, VEGF and VEGFR2 associated within the ER, activating inositol-requiring enzyme 1α, and thereby facilitating ERAD-mediated depletion of VEGFR2. MET disruption upregulated VEGFR2, inducing compensatory tumor growth via VEGFR2 and MEK. However, concurrent disruption of MET and either VEGF or MEK circumvented this, enabling more profound tumor inhibition. Our findings uncover unique cross-regulation between MET and VEGFR2—two RTKs that play significant roles in tumor malignancy. Furthermore, these results suggest rational combinatorial strategies for targeting RTK signaling pathways more effectively, which has potentially important implications for cancer therapy.

  11. Editing VEGFR2 Blocks VEGF-Induced Activation of Akt and Tube Formation

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    Huang, Xionggao; Zhou, Guohong; Wu, Wenyi; Ma, Gaoen; D'Amore, Patricia A.; Mukai, Shizuo; Lei, Hetian

    2017-01-01

    Purpose Vascular endothelial growth factor receptor 2 (VEGFR2) plays a key role in VEGF-induced angiogenesis. The goal of this project was to test the hypothesis that editing genomic VEGFR2 loci using the technology of clustered regularly interspaced palindromic repeats (CRISPR)-associated DNA endonuclease (Cas)9 in Streptococcus pyogenes (SpCas9) was able to block VEGF-induced activation of Akt and tube formation. Methods Four 20 nucleotides for synthesizing single-guide RNAs based on human genomic VEGFR2 exon 3 loci were selected and cloned into a lentiCRISPR v2 vector, respectively. The DNA fragments from the genomic VEGFR2 exon 3 of transduced primary human retinal microvascular endothelial cells (HRECs) were analyzed by Sanger DNA sequencing, surveyor nuclease assay, and next-generation sequencing (NGS). In the transduced cells, expression of VEGFR2 and VEGF-stimulated signaling events (e.g., Akt phosphorylation) were determined by Western blot analyses; VEGF-induced cellular responses (proliferation, migration, and tube formation) were examined. Results In the VEGFR2-sgRNA/SpCas9–transduced HRECs, Sanger DNA sequencing indicated that there were mutations, and NGS demonstrated that there were 83.57% insertion and deletions in the genomic VEGFR2 locus; expression of VEGFR2 was depleted in the VEGFR2-sgRNA/SpCas9–transduced HRECs. In addition, there were lower levels of Akt phosphorylation in HRECs with VEGFR2-sgRNA/SpCas9 than those with LacZ-sgRNA/SpCas9, and there was less VEGF-stimulated Akt activation, proliferation, migration, or tube formation in the VEGFR2-depleted HRECs than those treated with aflibercept or ranibizumab. Conclusions The CRISPR-SpCas9 technology is a potential novel approach to prevention of pathologic angiogenesis. PMID:28241310

  12. Anti-Angiogenic Therapy: Strategies to Develop Potent VEGFR-2 Tyrosine Kinase Inhibitors and Future Prospect.

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    Shi, Leilei; Zhou, Jianfeng; Wu, Jifeng; Shen, Yuemao; Li, Xun

    2016-01-01

    Tumor angiogenesis has always been a major gap for effective cancer therapy. Interruption of aberrant angiogenesis by specific inhibitors targeting receptor tyrosine kinases (RTKs) has been of great interests to medicinal chemists. Among the factors that are involved in tumor angiogenesis, vascular endothelial growth factor receptor-2 (VEGFR-2) is validated as the most closely related factor which can drive angiogenesis through binding with its natural ligand VEGF. The well-validated VEGF-driven VEGFR-2 signaling pathway can stimulate many endothelial responses, including increasing vessel permeability and enhancing endothelial cell proliferation, migration and differentiation. Consequently, circumventing angiogenesis by VEGFR-2 inhibitors represents a promising strategy for counteracting various VEGFR-2-mediated disorders as well as drug resistance. Over the past decades, a considerable number of novel small molecular VEGFR-2 inhibitors have been exploited with diverse chemical scaffolds. Especially, recent frequently launched inhibitors have declared their research values and therapeutic potentials in oncology. Still, the antiangiogenesis based treatment remains an ongoing challenge. In this review, a comprehensive retrospective of newly emerged VEGFR-2 inhibitors have been summarized, with the emphasis on the structure-activity relationship (SAR) investigation, and also binding patterns of representative inhibitors with biotargets. On the basis of all of this information, varied strategies for developing potent VEGFR-2 inhibitors and the future prospect of the clinical application of antiangiogenic inhibitors are discussed hereby.

  13. Angiogenesis impairment in diabetes: role of methylglyoxal-induced receptor for advanced glycation endproducts, autophagy and vascular endothelial growth factor receptor 2.

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    Hongtao Liu

    Full Text Available Diabetes impairs physiological angiogenesis by molecular mechanisms that are not fully understood. Methylglyoxal (MGO, a metabolite of glycolysis, is increased in patients with diabetes. This study defined the role of MGO in angiogenesis impairment and tested the mechanism in diabetic animals. Endothelial cells and mouse aortas were subjected to Western blot analysis of vascular endothelial growth factor receptor 2 (VEGFR2 protein levels and angiogenesis evaluation by endothelial cell tube formation/migration and aortic ring assays. Incubation with MGO reduced VEGFR2 protein, but not mRNA, levels in a time and dose dependent manner. Genetic knockdown of the receptor for advanced glycation endproducts (RAGE attenuated the reduction of VEGFR2. Overexpression of Glyoxalase 1, the enzyme that detoxifies MGO, reduced the MGO-protein adducts and prevented VEGFR2 reduction. The VEGFR2 reduction was associated with impaired angiogenesis. Suppression of autophagy either by inhibitors or siRNA, but not of the proteasome and caspase, normalized both the VEGFR2 protein levels and angiogenesis. Conversely, induction of autophagy either by rapamycin or overexpression of LC3 and Beclin-1 reduced VEGFR2 and angiogenesis. MGO increased endothelial LC3B and Beclin-1, markers of autophagy, which were accompanied by an increase of both autophagic flux (LC3 punctae and co-immunoprecipitation of VEGFR2 with LC3. Pharmacological or genetic suppression of peroxynitrite (ONOO(- generation not only blocked the autophagy but also reversed the reduction of VEGFR2 and angiogenesis. Like MGO-treated aortas from normglycemic C57BL/6J mice, aortas from diabetic db/db and Akita mice presented reductions of angiogenesis or VEGFR2. Administration of either autophagy inhibitor ex vivo or superoxide scavenger in vivo abolished the reductions. Taken together, MGO reduces endothelial angiogenesis through RAGE-mediated, ONOO(-dependent and autophagy-induced VEGFR2 degradation, which

  14. Cigarette smoke regulates VEGFR2-mediated survival signaling in rat lungs

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    Stevenson Christopher S

    2010-02-01

    Full Text Available Abstract Background Vascular endothelial growth factor (VEGF and VEGF receptor 2 (VEGFR2-mediated survival signaling is critical to endothelial cell survival, maintenance of the vasculature and alveolar structure and regeneration of lung tissue. Reduced VEGF and VEGFR2 expression in emphysematous lungs has been linked to increased endothelial cell death and vascular regression. Previously, we have shown that CS down-regulated the VEGFR2 and its downstream signaling in mouse lungs. However, the VEGFR2-mediated survival signaling in response to oxidants/cigarette smoke (CS is not known. We hypothesized that CS exposure leads to disruption of VEGFR2-mediated endothelial survival signaling in rat lungs. Methods Adult male Sprague-Dawley rats were exposed CS for 3 days, 8 weeks and 6 months to investigate the effect of CS on VEGFR2-mediated survival signaling by measuring the Akt/PI3-kinase/eNOS downstream signaling in rat lungs. Results and Discussion We show that CS disrupts VEGFR2/PI3-kinase association leading to decreased Akt and eNOS phosphorylation. This may further alter the phosphorylation of the pro-apoptotic protein Bad and increase the Bad/Bcl-xl association. However, this was not associated with a significant lung cell death as evidenced by active caspase-3 levels. These data suggest that although CS altered the VEGFR2-mediated survival signaling in the rat lungs, but it was not sufficient to cause lung cell death. Conclusion The rat lungs exposed to CS in acute, sub-chronic and chronic levels may be representative of smokers where survival signaling is altered but was not associated with lung cell death whereas emphysema is known to be associated with lung cell apoptosis.

  15. Vascular endothelial growth factor A and vascular endothelial growth factor receptor 2 expression in non-small cell lung cancer patients: relation to prognosis

    DEFF Research Database (Denmark)

    Bonnesen, Barbara; Pappot, Helle; Holmstav, Julie;

    2009-01-01

    elements in neoplastic cells and their microenvironment have recently been and are continuously developed including drugs inhibiting the angiogenic system. Angiogenic factor vascular endothelial growth factor (VEGF) and its receptor vascular endothelial growth factor receptor 2 (VEGFR2) seem to play key...

  16. The anti-tumour effect of a DNA vaccine carrying a fusion gene of human VEGFR2 and IL-12

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    Sha Wen

    2016-09-01

    Full Text Available Because of tumour dependence on angiogenesis, anti-angiogenic therapy has become the most attractive area of basic and clinical study in the field of cancer research. In order to create a synergistic effect on angiogenesis and immune regulation, we designed and constructed a new type of DNA vaccine that can express VEGFR2 (vascular endothelial growth factor receptor 2 and the prostate cancer antigen IL-12 (interleukin 12 in the same reading frame. The aim of this study was to investigate the anti-tumour activity of a eukaryotic expression plasmid carrying a fusion gene of human VEGFR2 and IL-12. According to the gene sequences in GenBank, we synthesized the human VEGFR2 and IL-12 genes. VEGFR2 and IL-12 were joined by a sequence encoding a Furin recognition site and a 2A cleavage site, and the resulting fusion gene was cloned into the eukaryotic expression vector pVAX1 to construct the expression plasmid pVAX1-VEGFR2-F2A-IL-12. The expression of VEGFR2 and IL-12 could be detected in 293T cells transfected with pVAX1-VEGFR2-F2A-IL-12 by enzyme-linked immunosorbent assay. Each of these proteins, and in particular co-expression of both proteins, can result in humoral and cellular immune responses in C57BL/6 mice. After injection into the tumour-bearing mouse model, the plasmid showed stronger inhibition of tumour growth than a plasmid expressing VEGFR2 alone. Our results demonstrate that a DNA vaccine carrying a fusion gene of human VEGFR2 and IL-12 could represent a promising approach for tumour immunotherapy.

  17. Stabiliztin of VEGFR2 Signaling by Cerebral Cavernous Malformation 3 is Critical for Vascular Development

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    Y He; H Zhang; L Yu; M Gunel; T Boggon; H Chen; W Min

    2011-12-31

    Cerebral cavernous malformations (CCMs) are human vascular malformations caused by mutations in three genes of unknown function: CCM1, CCM2, and CCM3. CCM3, also known as PDCD10 (programmed cell death 10), was initially identified as a messenger RNA whose abundance was induced by apoptotic stimuli in vitro. However, the in vivo function of CCM3 has not been determined. Here, we describe mice with a deletion of the CCM3 gene either ubiquitously or specifically in the vascular endothelium, smooth muscle cells, or neurons. Mice with global or endothelial cell-specific deletion of CCM3 exhibited defects in embryonic angiogenesis and died at an early embryonic stage. CCM3 deletion reduced vascular endothelial growth factor receptor 2 (VEGFR2) signaling in embryos and endothelial cells. In response to VEGF stimulation, CCM3 was recruited to and stabilized VEGFR2, and the carboxyl-terminal domain of CCM3 was required for the stabilization of VEGFR2. Indeed, the CCM3 mutants found in human patients lacking the carboxyl-terminal domain were labile and were unable to stabilize and activate VEGFR2. These results demonstrate that CCM3 promotes VEGFR2 signaling during vascular development.

  18. Endosome-to-Plasma Membrane Recycling of VEGFR2 Receptor Tyrosine Kinase Regulates Endothelial Function and Blood Vessel Formation.

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    Jopling, Helen M; Odell, Adam F; Pellet-Many, Caroline; Latham, Antony M; Frankel, Paul; Sivaprasadarao, Asipu; Walker, John H; Zachary, Ian C; Ponnambalam, Sreenivasan

    2014-04-29

    Rab GTPases are implicated in endosome-to-plasma membrane recycling, but how such membrane traffic regulators control vascular endothelial growth factor receptor 2 (VEGFR2/KDR) dynamics and function are not well understood. Here, we evaluated two different recycling Rab GTPases, Rab4a and Rab11a, in regulating endothelial VEGFR2 trafficking and signalling with implications for endothelial cell migration, proliferation and angiogenesis. In primary endothelial cells, VEGFR2 displays co-localisation with Rab4a, but not Rab11a GTPase, on early endosomes. Expression of a guanosine diphosphate (GDP)-bound Rab4a S22N mutant caused increased VEGFR2 accumulation in endosomes. TfR and VEGFR2 exhibited differences in endosome-to-plasma membrane recycling in the presence of chloroquine. Depletion of Rab4a, but not Rab11a, levels stimulated VEGF-A-dependent intracellular signalling. However, depletion of either Rab4a or Rab11a levels inhibited VEGF-A-stimulated endothelial cell migration. Interestingly, depletion of Rab4a levels stimulated VEGF-A-regulated endothelial cell proliferation. Rab4a and Rab11a were also both required for endothelial tubulogenesis. Evaluation of a transgenic zebrafish model showed that both Rab4 and Rab11a are functionally required for blood vessel formation and animal viability. Rab-dependent endosome-to-plasma membrane recycling of VEGFR2 is important for intracellular signalling, cell migration and proliferation during angiogenesis.

  19. The effect of multistage nanovector targeting of VEGFR2 positive tumor endothelia on cell adhesion and local payload accumulation.

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    Martinez, Jonathan O; Evangelopoulos, Michael; Karun, Vivek; Shegog, Evan; Wang, Joshua A; Boada, Christian; Liu, Xuewu; Ferrari, Mauro; Tasciotti, Ennio

    2014-12-01

    Nanovectors are a viable solution to the formulation of poorly soluble anticancer drugs. Their bioaccumulation in the tumor parenchyma is mainly achieved exploiting the enhanced permeability and retention (EPR) effect of the leaky neovasculature. In this paper we demonstrate that multistage nanovectors (MSV) exhibit rapid tumoritropic homing independent of EPR, relying on particle geometry and surface adhesion. By studying endothelial cells overexpressing vascular endothelial growth factor receptor-2 (VEGFR2), we developed MSV able to preferentially target VEGFR2 expressing tumor-associated vessels. Static and dynamic targeting revealed that MSV conjugated with anti-VEGFR2 antibodies displayed greater than a 4-fold increase in targeting efficiency towards VEGFR2 expressing cells while exhibiting minimal adherence to control cells. Additionally, VEGFR2 conjugation bestowed MSV with a significant increase in breast tumor targeting and in the delivery of a model payload while decreasing their accumulation in the liver. Surface functionalization with an anti-VEGFR2 antibody provided enhanced affinity towards the tumor vascular endothelium, which promoted enhanced adhesion and tumoritropic accumulation of a reporter molecule released by the MSV. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. In situ validation of VEGFR-2 and α v ß 3 integrin as targets for breast lesion characterization

    NARCIS (Netherlands)

    Ehling, J.; Misiewicz, M.; von Stillfried, S.; Möckel, D.; Bzyl, J.; Pochon, S.; Lederle, W.; Knuechel, R.; Lammers, Twan Gerardus Gertudis Maria; Palmowski, M.; Kiessling, F.

    2016-01-01

    Vascular endothelial growth factor receptor 2 (VEGFR-2) and αvß3 integrin are the most frequently addressed targets in molecular imaging of tumor angiogenesis. In preclinical studies, molecular imaging of angiogenesis has shown potential to detect and differentiate benign and malignant lesions of th

  1. In situ validation of VEGFR-2 and α v ß 3 integrin as targets for breast lesion characterization

    NARCIS (Netherlands)

    Ehling, J.; Misiewicz, M.; Stillfried, von S.; Möckel, D.; Bzyl, J.; Pochon, S.; Lederle, W.; Knuechel, R.; Lammers, T.G.G.M.; Palmowski, M.; Kiessling, F.

    2016-01-01

    Vascular endothelial growth factor receptor 2 (VEGFR-2) and αvß3 integrin are the most frequently addressed targets in molecular imaging of tumor angiogenesis. In preclinical studies, molecular imaging of angiogenesis has shown potential to detect and differentiate benign and malignant lesions of th

  2. Ramucirumab (IMC-1121B): Monoclonal antibody inhibition of vascular endothelial growth factor receptor-2.

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    Spratlin, Jennifer

    2011-04-01

    Angiogenesis, a well-recognized characteristic of malignancy, has been exploited more than any other pathway targeted by biologic anti-neoplastic therapies. Vascular endothelial growth factor receptor-2 (VEGFR-2) is the critical receptor involved in malignant angiogenesis with its activation inducing a number of other cellular modifications resulting in tumor growth and metastases. Ramucirumab (IMC-1121B; ImClone Systems Corporation, Branchburg, NJ) is a fully human monoclonal antibody developed to specifically inhibit VEGFR-2. Ramucirumab is currently being investigated in multiple clinical trials across a variety of tumor types. Herein, angiogenesis inhibition in cancer is reviewed and up-to-date information on the clinical development of ramucirumab is presented.

  3. Immunocytochemical localization of vascular endothelial growth factor and vascular endothelial growth factor receptor-2 of the human deciduous molar tooth germ development in the human fetus.

    Science.gov (United States)

    Miwa, Yoko; Fujita, Toshiya; Sunohara, Masataka; Sato, Iwao

    2008-01-01

    Vascular endothelial growth factor (VEGF) is a key regulator of blood vessel endothelial development. We used immunohistochemical methods to demonstrate the localization of VEGF and its receptors, showing the specific expression pattern of VEGF and VEGF receptor in the human deciduous tooth from the cap to late bell stages in the human fetus. Immunoreactivity to VEGF and its receptor VEGF receptor-2 (VEGFR-2) was intensely positive in the inner enamel epithelium at the cap stage and ranged from negative to moderately positive in the bell stage. At the late bell stage, VEGF immunoreactivity was mainly positive but weak for VEGFR-2. The intensity of VEGF and VEGFR-2 in odontoblasts increases from cap stage to late bell stage. We postulate that the dissimilar expression of VEGF in inner enamel epithelium, ameloblast and odontoblast during each stage of human tooth development may affect tooth germ formation.

  4. Discovery of Potent VEGFR-2 Inhibitors based on Furopyrimidine and Thienopyrimidne Scaffolds as Cancer Targeting Agents

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    Aziz, Marwa A.; Serya, Rabah A. T.; Lasheen, Deena S.; Abdel-Aziz, Amal Kamal; Esmat, Ahmed; Mansour, Ahmed M.; Singab, Abdel Nasser B.; Abouzid, Khaled A. M.

    2016-04-01

    Vascular endothelial growth factor receptor-2 (VEGFR-2) plays a crucial role in cancer angiogenesis. In this study, a series of novel furo[2,3-d]pyrimidine and thieno[2,3-d]pyrimidine based-derivatives were designed and synthesized as VEGFR-2 inhibitors, in accordance to the structure activity relationship (SAR) studies of known type II VEGFR-2 inhibitors. The synthesized compounds were evaluated for their ability to in vitro inhibit VEGFR-2 kinase enzyme. Seven compounds (15b, 16c, 16e, 21a, 21b, 21c and 21e) demonstrated highly potent dose-related VEGFR-2 inhibition with IC50 values in nanomolar range, of which the thieno[2,3-d]pyrimidine based-derivatives (21b, 21c and 21e) exhibited IC50 values of 33.4, 47.0 and 21 nM respectively. Moreover, furo[2,3-d]pyrimidine-based derivative (15b) showed the strongest inhibition of human umbilical vein endothelial cells (HUVEC) proliferation with 99.5% inhibition at 10 μM concentration. Consistent with our in vitro findings, compounds (21b and 21e) orally administered at 5 and 10 mg/kg/day for 8 consecutive days demonstrated potent anticancer activity in Erhlich ascites carcinoma (EAC) solid tumor murine model. Such compounds blunted angiogenesis in EAC as evidenced by reduced percent microvessel via decreasing VEGFR-2 phosphorylation with subsequent induction of apoptotic machinery. Furthermore, Miles vascular permeability assay confirmed their antiangiogenic effects in vivo. Intriguingly, such compounds showed no obvious toxicity.

  5. VEGFR-2 reduces while combined VEGFR-2 and -3 signaling increases inflammation in apical periodontitis

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    Virtej, Anca; Papadakou, Panagiota; Sasaki, Hajime; Bletsa, Athanasia; Berggreen, Ellen

    2016-01-01

    Background In apical periodontitis, oral pathogens provoke an inflammatory response in the apical area that induces bone resorptive lesions. In inflammation, angio- and lymphangiogenesis take place. Vascular endothelial growth factors (VEGFs) and their receptors (VEGFRs) are key players in these processes and are expressed in immune cells and endothelial cells in the lesions. Objective We aimed at testing the role of VEGFR-2 and -3 in periapical lesion development and investigated their role in lymphangiogenesis in the draining lymph nodes. Design We induced lesions by pulp exposure in the lower first molars of C57BL/6 mice. The mice received IgG injections or blocking antibodies against VEGFR-2 (anti-R2), VEGFR-3 (anti-R3), or combined VEGFR-2 and -3, starting on day 0 until day 10 or 21 post-exposure. Results Lesions developed faster in the anti-R2 and anti-R3 group than in the control and anti-R2/R3 groups. In the anti-R2 group, a strong inflammatory response was found expressed as increased number of neutrophils and osteoclasts. A decreased level of pro-inflammatory cytokines was found in the anti-R2/R3 group. Lymphangiogenesis in the draining lymph nodes was inhibited after blocking of VEGFR-2 and/or -3, while the largest lymph node size was seen after anti-R2 treatment. Conclusions We demonstrate an anti-inflammatory effect of VEGFR-2 signaling in periapical lesions which seems to involve neutrophil regulation and is independent of angiogenesis. Combined signaling of VEGFR-2 and -3 has a pro-inflammatory effect. Lymph node lymphangiogenesis is promoted through activation of VEGFR-2 and/or VEGFR-3. PMID:27650043

  6. Rhamnazin, a novel inhibitor of VEGFR2 signaling with potent antiangiogenic activity and antitumor efficacy

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Yao [Department of Ophthalmology, The First Affiliated Hospital of Nanchang University, Jiangxi Province Clinical Ophthalmology Institute, No.17 Yongwaizheng Street, Donghu District, Nanchang 330006, Jiangxi Province (China); Department of Endocrinology and Metabolism, The Third Hospital of Nanchang, Nanchang Key Laboratory of Diabetes, No.1 Qianjing Road, Xihu District, Nanchang 330009, Jiangxi Province (China); Cai, Wei [Department of Medical Genetics, College of Basic Medical Science of Nanchang University, No.461 Bayi Road, Donghu District, Nanchang 330006, Jiangxi Province (China); Pei, Chong-gang, E-mail: profchonggangpei@163.com [Department of Ophthalmology, The First Affiliated Hospital of Nanchang University, Jiangxi Province Clinical Ophthalmology Institute, No.17 Yongwaizheng Street, Donghu District, Nanchang 330006, Jiangxi Province (China); Shao, Yi, E-mail: profyishao@163.com [Department of Ophthalmology, The First Affiliated Hospital of Nanchang University, Jiangxi Province Clinical Ophthalmology Institute, No.17 Yongwaizheng Street, Donghu District, Nanchang 330006, Jiangxi Province (China)

    2015-03-20

    Anti-angiogenesis targeting vascular endothelial growth factor receptor 2 (VEGFR2) has emerged as an important tool for cancer therapy. The identification of new drugs from natural products has a long and successful history. In this study, we described a novel VEGFR2 inhibitor, rhamnazin, which inhibits tumor angiogenesis and growth. Rhamnazin significantly inhibited proliferation, migration and tube formation of human umbilical vascular endothelial cells (HUVECs) in vitro as well as inhibited sprouts formation of rat aorta ring. In addition, it inhibited vascular endothelial growth factor (VEGF)-induced phosphorylation of VEGFR2 and its downstream signaling regulator in HUVECs. Moreover, rhamnazin could directly inhibit proliferation of breast cancer cells MDA-MB-231 in vitro and in vivo. Oral administration of rhamnazin at a dose of 200 mg/kg/day could markedly inhibited human tumor xenograft growth and decreased microvessel densities (MVD) in tumor sections. Taken together, these preclinical evaluations suggest that rhamnazin inhibits angiogenesis and may be a promising anticancer drug candidate. - Highlights: • Rhamnazin inhibits the response of HUVECs to VEGF in vitro. • Rhamnazin inhibits VEGFR2 kinase activity and its downstream signaling. • Rhamnazin prevents the growth of MDA-MB-231 tumor and reduces micro-vessel density in vivo.

  7. TBX1 Represses Vegfr2 Gene Expression and Enhances the Cardiac Fate of VEGFR2+ Cells

    Science.gov (United States)

    Lania, Gabriella; Ferrentino, Rosa; Baldini, Antonio

    2015-01-01

    The T-box transcription factor TBX1 has critical roles in maintaining proliferation and inhibiting differentiation of cardiac progenitor cells of the second heart field (SHF). Haploinsufficiency of the gene that encodes it is a cause of congenital heart disease. Here, we developed an embryonic stem (ES) cell-based model in which Tbx1 expression can be modulated by tetracycline. Using this model, we found that TBX1 down regulates the expression of VEGFR2, and we confirmed this finding in vivo during embryonic development. In addition, we found a Vegfr2 domain of expression, not previously described, in the posterior SHF and this expression is extended by loss of Tbx1. VEGFR2 has been previously described as a marker of a subpopulation of cardiac progenitors. Clonal analysis of ES-derived VEGFR2+ cells indicated that 12.5% of clones expressed three markers of cardiac lineage (cardiomyocyte, smooth muscle and endothelium). However, a pulse of Tbx1 expression was sufficient to increase the percentage to 20.8%. In addition, the percentage of clones expressing markers of multiple cardiac lineages increased from 41.6% to 79.1% after Tbx1 pulse. These results suggest that TBX1 plays a role in maintaining a progenitor state in VEGFR2+ cells. PMID:26382615

  8. Neuropilin-1 mediates vascular permeability independently of vascular endothelial growth factor receptor-2 activation.

    Science.gov (United States)

    Roth, Lise; Prahst, Claudia; Ruckdeschel, Tina; Savant, Soniya; Weström, Simone; Fantin, Alessandro; Riedel, Maria; Héroult, Mélanie; Ruhrberg, Christiana; Augustin, Hellmut G

    2016-04-26

    Neuropilin-1 (NRP1) regulates developmental and pathological angiogenesis, arteriogenesis, and vascular permeability, acting as a coreceptor for semaphorin 3A (Sema3A) and the 165-amino acid isoform of vascular endothelial growth factor A (VEGF-A165). NRP1 is also the receptor for the CendR peptides, a class of cell- and tissue-penetrating peptides with a specific R-x-x-R carboxyl-terminal motif. Because the cytoplasmic domain of NRP1 lacks catalytic activity, NRP1 is mainly thought to act through the recruitment and binding to other receptors. We report here that the NRP1 intracellular domain mediates vascular permeability. Stimulation with VEGF-A165, a ligand-blocking antibody, and a CendR peptide led to NRP1 accumulation at cell-cell contacts in endothelial cell monolayers, increased cellular permeability in vitro and vascular leakage in vivo. Biochemical analyses, VEGF receptor-2 (VEGFR-2) silencing, and the use of a specific VEGFR blocker established that the effects induced by the CendR peptide and the antibody were independent of VEGFR-2. Moreover, leakage assays in mice expressing a mutant NRP1 lacking the cytoplasmic domain revealed that this domain was required for NRP1-induced vascular permeability in vivo. Hence, these data define a vascular permeability pathway mediated by NRP1 but independent of VEGFR-2 activation.

  9. BR55: a lipopeptide-based VEGFR2-targeted ultrasound contrast agent for molecular imaging of angiogenesis.

    Science.gov (United States)

    Pochon, Sibylle; Tardy, Isabelle; Bussat, Philippe; Bettinger, Thierry; Brochot, Jean; von Wronski, Mathew; Passantino, Lisa; Schneider, Michel

    2010-02-01

    BR55, an ultrasound contrast agent functionalized with a heterodimer peptide targeting the vascular endothelial growth factor receptor 2 (VEGFR2), was evaluated in vitro and in vivo, demonstrating its potential for specific tumor detection. The targeted contrast agent was prepared by incorporation of a biospecific lipopeptide into the microbubble membrane. Experiments were performed in vitro to demonstrate the binding capacities of BR55 microbubbles on immobilized receptor proteins and on various endothelial or transfected cells expressing VEGFR2. The performance of BR55 microbubbles was compared with that of streptavidin-conjugated microbubbles targeted to the same receptor by coupling them to a biotinylated antibody. The specificity of BR55 binding to human and mouse endothelial cells was determined in competition experiments with the free lipopeptide, vascular endothelial growth factor (VEGF), or a VEGFR2-specific antibody. Molecular ultrasound imaging of VEGFR2 was performed in an orthotopic breast tumor model in rats using a nondestructive, contrast-specific imaging mode. BR55 was shown to bind specifically to the immobilized recombinant VEGFR2 under flow (dynamic conditions). BR55 accumulation on the target over time was similar to that of microbubbles bearing a specific antibody. BR55 avidly bound to cells expressing VEGFR2, and the pattern of microbubble distribution was correlated with the pattern of receptor expression determined by immunocytochemistry. The binding of targeted microbubbles on cells was competed off by an excess of free lipopeptide, the natural ligand (VEGF) and by a VEGFR2-specific antibody (P < 0.001). Although selected for the human receptor, the VEGFR2-binding lipopeptide was also shown to recognize the rodent receptor. Tumor perfusion was assessed during the vascular phase of BR55, and then the malignant lesion was highlighted by specific accumulation of the targeted microbubbles on tumoral endothelium. The presence of VEGFR2 was

  10. Glycan-deficient PrP stimulates VEGFR2 signaling via glycosaminoglycan.

    Science.gov (United States)

    Gao, Zhenxing; Zhang, Huixia; Hu, Fei; Yang, Liheng; Yang, Xiaowen; Zhu, Ying; Sy, Man-Sun; Li, Chaoyang

    2016-06-01

    Whether the two N-linked glycans are important in prion, PrP, biology is unresolved. In Chinese hamster ovary (CHO) cells, the two glycans are clearly not important in the cell surface expression of transfected human PrP. Compared to fully-glycosylated PrP, glycan-deficient PrP preferentially partitions to lipid raft. In CHO cells glycan-deficient PrP also interacts with glycosaminoglycan (GAG) and vascular endothelial growth factor receptor 2 (VEGFR2), resulting in VEGFR2 activation and enhanced Akt phosphorylation. Accordingly, CHO cells expressing glycan-deficient PrP lacking the GAG binding motif or cells treated with heparinase to remove GAG show diminished Akt signaling. Being in lipid raft is critical, chimeric glycan-deficient PrP with CD4 transmembrane and cytoplasmic domains is absent in lipid raft and does not activate Akt signaling. CHO cells bearing glycan-deficient PrP also exhibit enhanced cellular adhesion and migration. Based on these findings, we propose a model in which glycan-deficient PrP, GAG, and VEGFR2 interact, activating VEGFR2 and resulting in changes in cellular behavior.

  11. Genetic variations in VEGF and VEGFR2 and glioblastoma outcome

    DEFF Research Database (Denmark)

    Sjöström, S; Wibom, C; Andersson, U

    2010-01-01

    Vascular endothelial growth factor (VEGF) and its receptors (VEGFR) are central components in the development and progression of glioblastoma. To investigate if genetic variation in VEGF and VEGFR2 is associated with glioblastoma prognosis, we examined blood samples from 154 glioblastoma cases...... collected in Sweden and Denmark between 2000 and 2004. Seventeen tagging single nucleotide polymorphisms (SNPs) in VEGF and 27 in VEGFR2 were genotyped and analysed, covering 90% of the genetic variability within the genes. In VEGF, we found no SNPs associated with survival. In VEGFR2, we found two SNPs...

  12. Genetic variations in VEGF and VEGFR2 and glioblastoma outcome

    DEFF Research Database (Denmark)

    Sjöström, S; Wibom, C; Andersson, U

    2011-01-01

    Vascular endothelial growth factor (VEGF) and its receptors (VEGFR) are central components in the development and progression of glioblastoma. To investigate if genetic variation in VEGF and VEGFR2 is associated with glioblastoma prognosis, we examined blood samples from 154 glioblastoma cases...... collected in Sweden and Denmark between 2000 and 2004. Seventeen tagging single nucleotide polymorphisms (SNPs) in VEGF and 27 in VEGFR2 were genotyped and analysed, covering 90% of the genetic variability within the genes. In VEGF, we found no SNPs associated with survival. In VEGFR2, we found two SNPs...

  13. The mechanisms that regulate the localization and overexpression of VEGF receptor-2 are promising therapeutic targets in cancer biology

    NARCIS (Netherlands)

    Kampen, Kim R.

    2012-01-01

    The vascular endothelial growth factor (VEGF) family has been proposed to be the most important signaling protein family in vessel formation and maturation. VEGF receptor-2 (VEGFR-2) plays an abundant role in the most common forms of cancer. The localization of VEGFR-2 expression is important in can

  14. In vitro and in vivo imaging of prostate cancer angiogenesis using anti-vascular endothelial growth factor receptor 2 antibody-conjugated quantum dot

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Haejin; Lee, Jiyeon; Song, Rita; Lee, Jung Han [Medicinal Chemistry Laboratory, Institute Pasteur Korea (IP-K), Seongnam (Korea, Republic of); Hwang, Sung Il; Lee, Hak Jong [Seoul National University Bundang Hospital, Institute of Radiation Medicine, Seoul National University Medical Research Center, Clinical Research Institute, Seongnam (Korea, Republic of); Kim, Young Hwa [Cancer Research Institute, Seoul National University College of Medicine, Seoul (Korea, Republic of)

    2013-01-15

    Authors aimed to determine the targeting ability of vascular endothelial growth factor receptor 2 (VEGFR2)-conjugated quantum dots (QDs) in vitro, and apply it for a xenograft prostate cancer mouse model. Conjugation reaction of QDs was performed by using the N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide (EDC) and sulfo-(N-hydroxysulfosuccinimide) (Sulfo-NHS). The human umbilical vein cord endothelial cells (HUVECs) were incubated with QDs, conjugated with antiVGFR2, to see a specific binding in vitro. Fluorescent cell images were taken by a confocal microscope. The human prostate cancer cells (PC3) were injected to five nude mice on hind limbs to make the xenograft tumor model. QD-antiVEGFR2 antibody complex was injected into the tumor model and fluorescence measurements were performed at 1, 4, 9, 12, 15, and 24 hours after the injection. The specific interaction between HUVECs and QD-antiVEGFR2 antibody was clearly shown in vitro. The in vivo fluorescence image disclosed that there was an increased signal of tumor, 12 hours after the injection of QDs. By showing endothelial cells binding with QDs-antiVEGFR2 antibodyand an experimental application of the antibody for VEGFR2 imaging in the prostate cancer xenograft mouse model, we suggests that the antibody-conjugated QDs can be a potential imaging tool for angiogenesis of the cancer.

  15. Deregulation of Flk-1/vascular endothelial growth factor receptor-2 in fibroblast growth factor receptor-1-deficient vascular stem cell development.

    Science.gov (United States)

    Magnusson, Peetra; Rolny, Charlotte; Jakobsson, Lars; Wikner, Charlotte; Wu, Yan; Hicklin, Daniel J; Claesson-Welsh, Lena

    2004-03-15

    We have employed embryoid bodies derived from murine embryonal stem cells to study effects on vascular development induced by fibroblast growth factor (FGF)-2 and FGF receptor-1, in comparison to the established angiogenic factor vascular endothelial growth factor (VEGF)-A and its receptor VEGF receptor-2. Exogenous FGF-2 promoted formation of morphologically distinct, long slender vessels in the embryoid bodies, whereas VEGF-A-treated bodies displayed a compact plexus of capillaries. FGF-2 stimulation of embryonal stem cells under conditions where VEGF-A/VEGFR-2 function was blocked, led to formation of endothelial cell clusters, which failed to develop into vessels. FGFR-1(-/-) embryoid bodies responded to VEGF-A by establishment of the characteristic vascular plexus, but FGF-2 had no effect on vascular development in the absence of FGFR-1. The FGFR-1(-/-) embryoid bodies displayed considerably increased basal level of vessel formation, detected by immunohistochemical staining for platelet-endothelial cell adhesion molecule (PECAM)/CD31. This basal vascularization was blocked by neutralizing antibodies against VEGFR-2 or VEGF-A and biochemical analyses indicated changes in regulation of VEGFR-2 in the absence of FGFR-1 expression. We conclude that VEGF-A/VEGFR-2-dependent vessel formation occurs in the absence of FGF-2/FGFR-1, which, however, serve to modulate vascular development.

  16. The relationship of the angiogenesis regulators VEGF-A, VEGF-R1 and VEGF-R2 to p53 status and prognostic factors in epithelial ovarian carcinoma in FIGO-stages I-II.

    Science.gov (United States)

    Skirnisdottir, Ingiridur; Seidal, Tomas; Åkerud, Helena

    2016-03-01

    The aim of this study was to evaluate prognostic effect of the angiogenesis regulators VEGF-R1, VEGF-R2 and VEGF-A for recurrent disease and disease-free survival (DFS), and their relation to the apoptosis regulator p53, in 131 patients with FIGO-stages I-II with epithelial ovarian cancer. For the detection of positivity of the markers the techniques of tissue microarrays and immunohistochemistry (IHC) were used. In tumors the frequency of positive staining for VEGF-R1 was 19%, for VEGF-R2 and VEGF-A, it was 77 and 70%, respectively. Positivity for p53 was detected in 25% of tumors. The total number of recurrences in the complete series was 34 out of 131 (26%) and 5-year disease-free survival (DFS) was 68%. Positive staining for VEGF-A (P=0.030), VEGF-R2 (P=0.011) and p53 (P=0.015) was found more frequently in type II tumors than in type I tumors. Patients with VEGF-R1 negative tumors had worse (P=0.021) DFS compared to patients with VEGF-R1 positive tumors. In two multivariate Cox analyzes with DFS as endpoint, FIGO-stage (HR=3.8), VEGF-R2 status (HR=0.4) and p53 status (HR=2.3), all were significant and independent prognostic factors. When the variables VEGF-R2 and p53 were replaced with the new variable VEGF-R2+p53-/other three combinations in one group, it was found that patients from that subgroup had 86% reduced risk of dying in disease (HR=0.24). Findings above, confirmed relationship between VEGF-R2 and VEGF-A and p53, respectively, with regard to recurrent disease and survival. Some findings from the present study are different from results from previous studies on the regulation of angiogenesis. Despite many trials with anti-angiogenic agents in the front line of ovarian cancer have shown to be positive for progression-free survival, no one has demonstrated an impact on overall survival. Therefore, one of the greatest challenges in ovarian cancer research, is to discover predictive and prognostic biomarkers.

  17. In situ validation of VEGFR-2 and α v ß 3 integrin as targets for breast lesion characterization.

    Science.gov (United States)

    Ehling, Josef; Misiewicz, Matthias; von Stillfried, Saskia; Möckel, Diana; Bzyl, Jessica; Pochon, Sibylle; Lederle, Wiltrud; Knuechel, Ruth; Lammers, Twan; Palmowski, Moritz; Kiessling, Fabian

    2016-04-01

    Vascular endothelial growth factor receptor 2 (VEGFR-2) and α v ß 3 integrin are the most frequently addressed targets in molecular imaging of tumor angiogenesis. In preclinical studies, molecular imaging of angiogenesis has shown potential to detect and differentiate benign and malignant lesions of the breast. Thus, in this retrospective clinical study employing patient tissues, the diagnostic value of VEGFR-2, α v ß 3 integrin and vascular area fraction for the diagnosis and differentiation of breast neoplasia was evaluated. To this end, tissue sections of breast cancer (n = 40), pre-invasive ductal carcinoma in situ (DCIS; n = 8), fibroadenoma (n = 40), radial scar (n = 6) and normal breast tissue (n = 40) were used to quantify (1) endothelial VEGFR-2, (2) endothelial α v ß 3 integrin and (3) total α v ß 3 integrin expression, as well as (4) the vascular area fraction. Sensitivity and specificity to differentiate benign from malignant lesions were calculated for each marker by receiver operating characteristics (ROC) analyses. Whereas vessel density, as commonly used, did not significantly differ between benign and malignant lesions (AUROC: 0.54), VEGFR-2 and α v ß 3 integrin levels were gradually up-regulated in carcinoma versus fibroadenoma versus healthy tissue. The highest diagnostic accuracy for differentiating carcinoma from fibroadenoma was found for total α v ß 3 integrin expression (AUROC: 0.76), followed by VEGFR-2 (AUROC: 0.71) and endothelial α v ß 3 integrin expression (AUROC: 0.68). In conclusion, total α v ß 3 integrin expression is the best discriminator between breast cancer, fibroadenoma and normal breast tissue. With respect to vascular targeting and molecular imaging of angiogenesis, endothelial VEGFR-2 appeared to be slightly superior to endothelial α v ß 3 for differentiating benign from cancerous lesions.

  18. VEGF internalization is not required for VEGFR-2 phosphorylation in bioengineered surfaces with covalently linked VEGF

    Science.gov (United States)

    Anderson, Sean M.; Shergill, Bhupinder; Barry, Zachary T.; Manousiouthakis, Eleana; Chen, Tom T.; Botvinick, Elliot; Platt, Manu O.; Iruela-Arispe, M. Luisa; Segura, Tatiana

    2011-01-01

    Vascular endothelial growth factor (VEGF) is known to activate proliferation, migration, and survival pathways in endothelial cells through phosphorylation of VEGF receptor-2 (VEGFR-2). VEGF has been incorporated into biomaterials through encapsulation, electrostatic sequestration, and covalent attachment, but the effect of these immobilization strategies on VEGF signaling has not been thoroughly investigated. Further, although growth factor internalization along with the receptor generally occurs in a physiological setting, whether this internalization is needed for receptor phosphorylation is not entirely clear. Here we show that VEGF covalently bound through a modified heparin molecule elicits an extended response of pVEGFR-2 in human umbilical vein endothelial cells (HUVECs) and that the covalent linkage reduces internalization of the growth factor during receptor endocytosis. Optical tweezer measurements show that the rupture force required to disrupt the heparin-VEGF-VEGFR-2 interaction increases from 3–8 pN to 6–12 pN when a covalent bond is introduced between VEGF and heparin. Importantly, by covalently binding VEGF to a heparin substrate, the stability (half-life) of VEGF is extended over three-fold. Here, mathematical models support the biological conclusions, further suggesting that VEGF internalization is significantly reduced when covalently bound, and indicating that VEGF is available for repeated phosphorylation events. PMID:21826315

  19. A Case Report of Ischemic Stroke in a Patient with Metastatic Gastric Cancer Secondary to Treatment with the Vascular Endothelial Growth Factor Receptor-2 Inhibitor Ramucirumab

    Directory of Open Access Journals (Sweden)

    Michael E. Christiansen

    2016-06-01

    Full Text Available Ramucirumab is an antiangiogenesis agent targeting the vascular endothelial growth factor receptor-2 (VEGFR-2, approved to treat advanced gastric and colon cancer. In clinical trials, it was shown to cause a small increase in arterial thromboembolism compared to placebo, including cerebral and myocardial ischemia, which was not statistically significant. Detailed case reports are lacking and we here present one of the first case reports of stroke secondary to ramucirumab-induced in situ thrombosis.

  20. Targeting Vascular Endothelial Growth Factor Receptor 2 and Protein Kinase D1 Related Pathways by a Multiple Kinase Inhibitor in Angiogenesis and Inflammation Related Processes In Vitro

    OpenAIRE

    Attila Varga; Pál Gyulavári; Zoltán Greff; Krisztina Futosi; Tamás Németh; Laura Simon-Szabó; Krisztina Kerekes; Csaba Szántai-Kis; Diána Brauswetter; Márton Kokas; Gábor Borbély; Anna Erdei; Attila Mócsai; György Kéri; Tibor Vántus

    2015-01-01

    Emerging evidence suggests that the vascular endothelial growth factor receptor 2 (VEGFR2) and protein kinase D1 (PKD1) signaling axis plays a critical role in normal and pathological angiogenesis and inflammation related processes. Despite all efforts, the currently available therapeutic interventions are limited. Prior studies have also proved that a multiple target inhibitor can be more efficient compared to a single target one. Therefore, development of novel inflammatory pathway-specific...

  1. A role for VEGFR2 activation in endothelial responses caused by barrier disruptive OxPAPC concentrations.

    Directory of Open Access Journals (Sweden)

    Anna A Birukova

    Full Text Available Oxidation products of 1-palmitoyl-2-arachidonoyl-sn-glycero-3-phosphatidylcholine (OxPAPC differentially modulate endothelial cell (EC barrier function in a dose-dependent fashion. Vascular endothelial growth factor receptor-2 (VEGFR2 is involved in the OxPAPC-induced EC inflammatory activation. This study examined a role of VEGFR2 in barrier dysfunction caused by high concentrations of OxPAPC and evaluated downstream signaling mechanisms resulting from the effect of OxPAPC in EC from pulmonary and systemic circulation.EC monolayer permeability in human pulmonary artery endothelial cells (HPAEC and human aortic endothelial cells (HAEC was monitored by changes in transendothelial electrical resistance (TER across EC monolayers. Actin cytoskeleton was examined by immunostaining with Texas Red labeled phalloidin. Phosphorylation of myosin light chains (MLC and VE-Cadherin was examined by Western blot and immunofluorescence techniques. The role of VEGFR2 in OxPAPC-induced permeability and cytoskeletal arrangement were determined using siRNA-induced VEGFR2 knockdown.Low OxPAPC concentrations (5-20 µg/ml induced a barrier protective response in both HPAEC and HAEC, while high OxPAPC concentrations (50-100 µg/ml caused a rapid increase in permeability; actin stress fiber formation and increased MLC phosphorylation were observed as early as 30 min after treatment. VEGFR2 knockdown dramatically decreased the amount of MLC phosphorylation and stress fiber formation caused by high OxPAPC concentrations with modest effects on the amount of VE-cadherin phosphorylation at Y(731. We present evidence that activation of Rho is involved in the OxPAPC/VEGFR2 mechanism of EC permeability induced by high OxPAPC concentrations. Knockdown of VEGFR2 did not rescue the early drop in TER but prevented further development of OxPAPC-induced barrier dysfunction.This study shows that VEGFR2 is involved in the delayed phase of EC barrier dysfunction caused by high Ox

  2. Selective flexibility of side-chain residues improves VEGFR-2 docking score using AutoDock Vina.

    Science.gov (United States)

    Abreu, Rui M V; Froufe, Hugo J C; Queiroz, Maria-João R P; Ferreira, Isabel C F R

    2012-04-01

    Selective side-chain residue flexibility is an option available on AutoDock Vina docking software. This approach is promising as it attempts to provide a more realistic ligand-protein interaction environment without an unmanageable increase in computer processing time. However, studies validating this approach are still scarce. VEGFR-2 (vascular endothelial growth factor receptor 2), a known protein target for anti-angiogenic agents, was used in this study. Four residues located in the VEGFR-2 kinase site were selected and made flexible: Lys868, Glu885, Cys919, and Asp1046. The docking scores for all possible combinations of flexible residues were compared to the docking scores using a rigid conformation. The best overall docking scores were obtained using the Glu885 flexible conformation, with Pearson and Spearman rank correlation values of 0.568 and 0.543, respectively, and a 51% increase in processing time. Using different VEGFR-2 crystal structures, a similar trend was observed with the Glu885 flexible conformation presenting best scores. This study demonstrates that careful use of selective side-chain residue flexibility can improve AutoDock Vina docking score accuracy, without a significant increase in processing time. This methodology can be a valuable tool in drug design projects using VEGFR-2 but will also probably be useful if applied to other protein targets. © 2011 John Wiley & Sons A/S.

  3. Glioma cell VEGFR-2 confers resistance to chemotherapeutic and antiangiogenic treatments in PTEN-deficient glioblastoma.

    Science.gov (United States)

    Kessler, Tobias; Sahm, Felix; Blaes, Jonas; Osswald, Matthias; Rübmann, Petra; Milford, David; Urban, Severino; Jestaedt, Leonie; Heiland, Sabine; Bendszus, Martin; Hertenstein, Anne; Pfenning, Philipp-Niclas; Ruiz de Almodóvar, Carmen; Wick, Antje; Winkler, Frank; von Deimling, Andreas; Platten, Michael; Wick, Wolfgang; Weiler, Markus

    2015-10-13

    Loss of the tumor suppressor phosphatase and tensin homolog deleted on chromosome 10 (PTEN) is a prerequisite for tumor cell-specific expression of vascular endothelial growth factor receptor (VEGFR)-2 in glioblastoma defining a subgroup prone to develop evasive resistance towards antiangiogenic treatments. Immunohistochemical analysis of human tumor tissues showed VEGFR-2 expression in glioma cells in 19% of specimens examined, mainly in the infiltration zone. Glioma cell VEGFR-2 positivity was restricted to PTEN-deficient tumor specimens. PTEN overexpression reduced VEGFR-2 expression in vitro, as well as knock-down of raptor or rictor. Genetic interference with VEGFR-2 revealed proproliferative, antiinvasive and chemoprotective functions for VEGFR-2 in glioma cells. VEGFR-2-dependent cellular effects were concomitant with activation of 'kappa-light-chain-enhancer' of activated B-cells, protein kinase B, and N-myc downstream regulated gene 1. Two-photon in vivo microscopy revealed that expression of VEGFR-2 in glioma cells hampers antiangiogenesis. Bevacizumab induces a proinvasive response in VEGFR-2-positive glioma cells. Patients with PTEN-negative glioblastomas had a shorter survival after initiation of bevacizumab therapy compared with PTEN-positive glioblastomas. Conclusively, expression of VEGFR-2 in glioma cells indicates an aggressive glioblastoma subgroup developing early resistance to temozolomide or bevacizumab. Loss of PTEN may serve as a biomarker identifying those tumors upfront by routine neuropathological methods.

  4. Microultrasound Molecular Imaging of Vascular Endothelial Growth Factor Receptor 2 in a Mouse Model of Tumor Angiogenesis

    Directory of Open Access Journals (Sweden)

    Joshua J. Rychak

    2007-09-01

    Full Text Available High-frequency microultrasound imaging of tumor progression in mice enables noninvasive anatomic and functional imaging at excellent spatial and temporal resolution, although microultrasonography alone does not offer molecular scale data. In the current study, we investigated the use of microbubble ultrasound contrast agents bearing targeting ligands specific for molecular markers of tumor angiogenesis using high-frequency microultrasound imaging. A xenograft tumor model in the mouse was used to image vascular endothelial growth factor receptor 2 (VEGFR-2 expression with microbubbles conjugated to an anti-VEGFR-2 monoclonal antibody or an isotype control. Microultrasound imaging was accomplished at a center frequency of 40 MHz, which provided lateral and axial resolutions of 40 and 90 μm, respectively. The B-mode (two-dimensional mode acoustic signal from microbubbles bound to the molecular target was determined by an ultrasound-based destruction-subtraction scheme. Quantification of the adherent microbubble fraction in nine tumor-bearing mice revealed significant retention of VEGFR-2-targeted microbubbles relative to control-targeted microbubbles. These data demonstrate that contrast-enhanced microultrasound imaging is a useful method for assessing molecular expression of tumor angiogenesis in mice at high resolution.

  5. MMP14 as a novel downstream target of VEGFR2 in migratory glioma-tropic neural stem cells

    Directory of Open Access Journals (Sweden)

    Nikita G. Alexiades

    2015-11-01

    Full Text Available Neural stem cell (NSC-based carriers have been presented as promising therapeutic tools for the treatment of infiltrative brain tumors due to their intrinsic tumor homing property. They have demonstrated the ability to migrate towards distant tumor microsatellites and effectively deliver the therapeutic payload, thus significantly improving survival in experimental animal models for brain tumor. Despite such optimistic results, the efficacy of NSC-based anti-cancer therapy has been limited due to the restricted tumor homing ability of NSCs. To examine this issue, we investigated the mechanisms of tumor-tropic migration of an FDA-approved NSC line, HB1.F3.CD, by performing a gene expression analysis. We identified vascular endothelial growth factor-A (VEGFA and membrane-bound matrix metalloproteinase (MMP14 as molecules whose expression are significantly elevated in migratory NSCs. We observed increased expression of VEGF receptor 2 (VEGFR2 in the focal adhesion complexes of migratory NSCs, with downstream activation of VEGFR2-dependent kinases such as p-PLCγ, p-FAK, and p-Akt, a signaling cascade reported to be required for cellular migration. In an in vivo orthotopic glioma xenograft model, analysis of the migratory trail showed that NSCs maintained expression of VEGFR2 and preferentially migrated within the perivascular space. Knockdown of VEGFR2 via shRNAs led to significant downregulation of MMP14 expression, which resulted in inhibited tumor-tropic migration. Overall, our results suggest, the involvement of VEGFR2-regulated MMP14 in the tumor-tropic migratory behavior of NSCs. Our data warrant investigation of MMP14 as a target for enhancing the migratory properties of NSC carriers and optimizing the delivery of therapeutic payloads to disseminated tumor burdens.

  6. Decorin is a novel VEGFR-2-binding antagonist for the human extravillous trophoblast.

    Science.gov (United States)

    Khan, Gausal A; Girish, Gannareddy V; Lala, Neena; Di Guglielmo, Gianni M; Lala, Peeyush K

    2011-08-01

    Extravillous trophoblasts (EVT) of the human placenta invade the uterine decidua and its arteries to ensure successful placentation. We previously identified two decidua-derived molecules, TGF-β and a TGF-β-binding proteoglycan decorin (DCN), as negative regulators of EVT proliferation, migration, and invasiveness and reported that DCN acts via multiple tyrosine kinase receptors [epidermal growth factor-receptor (EGF-R), IGF receptor-1 (IGFR1), and vascular endothelial growth factor 2 receptor (VEGFR-2)]. Because binding of DCN to VEGFR-2 has never been reported earlier, present study explored this binding, the approximate location of VEGFR-2-binding site in DCN, and its functional role in our human first trimester EVT cell line HTR-8/SVneo. Based on far-Western blotting and coimmunoprecipitation studies, we report that DCN binds both native (EVT expressed) and recombinant VEGFR-2 and that this binding is abrogated with a VEGFR-2 blocking antibody, indicating an overlap between the ligand-binding and the DCN-binding domains of VEGFR-2. We determined that (125)I-labeled VEGF-E (a VEGFR-2 specific ligand) binds EVT with a dissociation constant (K(d)) of 566 pM, and DCN displaced this binding with an inhibition constant (K(i)) of 3.93-5.78 nM, indicating a 7- to 10-fold lower affinity of DCN for VEGFR-2. DCN peptide fragments derived from the leucine rich repeat 5 domain that blocked DCN-VEGFR-2 interactions or VEGF-E binding in EVT cells also blocked VEGF-A- and VEGF-E-induced EVT cell proliferation and migration, indicative of functional VEGFR-2-binding sites of DCN. Finally, DCN inhibited VEGF-E-induced EVT migration by interfering with ERK1/2 activation. Our findings reveal a novel role of DCN as an antagonistic ligand for VEGFR-2, having implications for pathophysiology of preeclampsia, a trophoblast hypoinvasive disorder in pregnancy, and explain its antiangiogenic function.

  7. Localization of vascular endothelial growth factor (VEGF) and its receptors VEGFR-1 and VEGFR-2 in bovine placentomes from implantation until term

    DEFF Research Database (Denmark)

    Pfarrer, C.D.; Ruziwa, S.D.; Winther, H.

    2006-01-01

    epithelium. An antibody against bovine VEGF revealed a strong reactivity in the stroma of maternal caruncular septa in early and mid-gestation, which distinctly decreased near term. In interplacentomal areas, VEGF was found in luminal and glandular epithelia as well as in trophoblast, with distinctly higher...... term were evaluated by immunohistochemistry. VEGF immunoreactivity was detected in fetal and maternal blood vessel tissues during implantation and throughout gestation, and in preimplantatory trophoblast cells and uterine epithelium. After implantation the immunoreaction was confined to TGC and uterine...... reactivity in giant cells. VEGFR-1 was observed in trophoblast and uterine epithelium around implantation. Later, in definite placentomes, VEGFR-1 was localized in TGC near the chorionic plate and in maternal endothelial cells in the center of the placentome. VEGFR-1 and VEGFR-2 were co-localized in uterine...

  8. Determination of VEGFR-2 (KDR 604A>G Polymorphism in Pancreatic Disorders

    Directory of Open Access Journals (Sweden)

    Vlad Pădureanu

    2017-02-01

    Full Text Available Pancreatic disorders have a high prevalence worldwide. Despite the fact that screening methods became more effective and the knowledge we have nowadays about pancreatic diseases has enhanced, their incidence remains high. Our purpose was to determine whether single nucleotide polymorphism (SNP of VEGFR-2/KDR (vascular endothelial growth factor receptor 2/kinase insert domain receptor influences susceptibility to develop pancreatic pathology. Genomic DNA was extracted from blood samples collected from patients diagnosed with acute pancreatitis (n = 110, chronic pancreatitis (n = 25, pancreatic cancer (n = 82 and healthy controls (n = 232. VEGFR-2 (KDR 604A>G (rs2071559 polymorphism frequency was determined with TaqMan allelic discrimination assays. Statistical assessment was performed by associating genetic polymorphism with clinical and pathological data. In both pancreatic disorders and healthy control groups the polymorphism we studied was in Hardy-Weinberg equilibrium. Association between increased risk for pancreatic disorders and studied polymorphism was statistically significant. KDR 604AG and AG + GG genotypes were more prevalent in acute pancreatitis and pancreatic cancer patients than in controls. These genotypes influence disease development in a low rate. No association was found between chronic pancreatitis and KDR 604AG and AG + GG genotypes. In Romanian cohort, we found an association between the KDR 604A→G polymorphism and acute pancreatitis and pancreatic cancer. Carriers of the -604G variant allele were more frequent among acute pancreatitis and pancreatic cancer than among controls, suggesting that KDR 604G allele may confer an increased risk for these diseases. In the future, more extensive studies on larger groups are necessary, in order to clarify the role of VEGFR2 polymorphisms in pancreatic pathology.

  9. Determination of VEGFR-2 (KDR) 604A>G Polymorphism in Pancreatic Disorders

    Science.gov (United States)

    Pădureanu, Vlad; Boldeanu, Mihail Virgil; Streaţă, Ioana; Cucu, Mihai Gabriel; Siloşi, Isabela; Boldeanu, Lidia; Bogdan, Maria; Enescu, Anca Ştefania; Forţofoiu, Maria; Enescu, Aurelia; Dumitrescu, Elena Mădălina; Alexandru, Dragoş; Şurlin, Valeriu Marian; Forţofoiu, Mircea Cătălin; Petrescu, Ileana Octavia; Petrescu, Florin; Ioana, Mihai; Ciurea, Marius Eugen; Săftoiu, Adrian

    2017-01-01

    Pancreatic disorders have a high prevalence worldwide. Despite the fact that screening methods became more effective and the knowledge we have nowadays about pancreatic diseases has enhanced, their incidence remains high. Our purpose was to determine whether single nucleotide polymorphism (SNP) of VEGFR-2/KDR (vascular endothelial growth factor receptor 2/kinase insert domain receptor) influences susceptibility to develop pancreatic pathology. Genomic DNA was extracted from blood samples collected from patients diagnosed with acute pancreatitis (n = 110), chronic pancreatitis (n = 25), pancreatic cancer (n = 82) and healthy controls (n = 232). VEGFR-2 (KDR) 604A>G (rs2071559) polymorphism frequency was determined with TaqMan allelic discrimination assays. Statistical assessment was performed by associating genetic polymorphism with clinical and pathological data. In both pancreatic disorders and healthy control groups the polymorphism we studied was in Hardy-Weinberg equilibrium. Association between increased risk for pancreatic disorders and studied polymorphism was statistically significant. KDR 604AG and AG + GG genotypes were more prevalent in acute pancreatitis and pancreatic cancer patients than in controls. These genotypes influence disease development in a low rate. No association was found between chronic pancreatitis and KDR 604AG and AG + GG genotypes. In Romanian cohort, we found an association between the KDR 604A→G polymorphism and acute pancreatitis and pancreatic cancer. Carriers of the -604G variant allele were more frequent among acute pancreatitis and pancreatic cancer than among controls, suggesting that KDR 604G allele may confer an increased risk for these diseases. In the future, more extensive studies on larger groups are necessary, in order to clarify the role of VEGFR2 polymorphisms in pancreatic pathology. PMID:28218664

  10. Wild Roman chamomile extracts and phenolic compounds: enzymatic assays and molecular modelling studies with VEGFR-2 tyrosine kinase.

    Science.gov (United States)

    Guimarães, Rafaela; Calhelha, Ricardo C; Froufe, Hugo J C; Abreu, Rui M V; Carvalho, Ana Maria; Queiroz, Maria João R P; Ferreira, Isabel C F R

    2016-01-01

    Angiogenesis is a process by which new blood vessels are formed from the pre-existing vasculature, and it is a key process that leads to tumour development. Some studies have recognized phenolic compounds as chemopreventive agents; flavonoids, in particular, seem to suppress the growth of tumor cells modifying the cell cycle. Herein, the antiangiogenic activity of Roman chamomile (Chamaemelum nobile L.) extracts (methanolic extract and infusion) and the main phenolic compounds present (apigenin, apigenin-7-O-glucoside, caffeic acid, chlorogenic acid, luteolin, and luteolin-7-O-glucoside) was evaluated through enzymatic assays using the tyrosine kinase intracellular domain of the Vascular Endothelium Growth Factor Receptor-2 (VEGFR-2), which is a transmembrane receptor expressed fundamentally in endothelial cells involved in angiogenesis, and molecular modelling studies. The methanolic extract showed a lower IC50 value (concentration that provided 50% of VEGFR-2 inhibition) than the infusion, 269 and 301 μg mL(-1), respectively. Regarding phenolic compounds, luteolin and apigenin showed the highest capacity to inhibit the phosphorylation of VEGFR-2, leading us to believe that these compounds are involved in the activity revealed by the methanolic extract.

  11. The rs2071559 AA VEGFR-2 Genotype Frequency Is Significantly Lower in Neovascular Age-Related Macular Degeneration Patients

    Directory of Open Access Journals (Sweden)

    Stefano Lazzeri

    2012-01-01

    Full Text Available In this prospective, case-control genetic study, 120 consecutive neovascular age-related macular degeneration (AMD cases and 78 controls were enrolled. Two SNPs (rs2071559 and rs1870377 of VEGF-A receptor-2 (VEGFR-2 gene were analyzed with the technique of Real-Time PCR to investigate a genetic link between AMD and VEGFR-2 gene polymorphisms in Italian patients. The frequency of the VEGFR-2 genotype rs2071559 AA was significantly lower (18.33% in patients with AMD than in the control subjects (34.62%; P=0.0095, chi-square test; Pcorr=0.038; OR=0.42, 95% CI 0.22 to 0.82. In conclusion, although with the limitations of a small sample size and the few SNPs studied, this study demonstrates a lower frequency of VEGFR-2 rs2071559 AA genotype in an AMD patient population, suggesting future studies on the role VEGFR-2 SNPs.

  12. The rs2071559 AA VEGFR-2 genotype frequency is significantly lower in neovascular age-related macular degeneration patients.

    Science.gov (United States)

    Lazzeri, Stefano; Orlandi, Paola; Figus, Michele; Fioravanti, Anna; Cascio, Elisa; Di Desidero, Teresa; Agosta, Elisa; Canu, Bastianina; Sartini, Maria Sole; Danesi, Romano; Nardi, Marco; Bocci, Guido

    2012-01-01

    In this prospective, case-control genetic study, 120 consecutive neovascular age-related macular degeneration (AMD) cases and 78 controls were enrolled. Two SNPs (rs2071559 and rs1870377) of VEGF-A receptor-2 (VEGFR-2) gene were analyzed with the technique of Real-Time PCR to investigate a genetic link between AMD and VEGFR-2 gene polymorphisms in Italian patients. The frequency of the VEGFR-2 genotype rs2071559 AA was significantly lower (18.33%) in patients with AMD than in the control subjects (34.62%; P = 0.0095, chi-square test; P(corr) = 0.038; OR = 0.42, 95% CI 0.22 to 0.82). In conclusion, although with the limitations of a small sample size and the few SNPs studied, this study demonstrates a lower frequency of VEGFR-2 rs2071559 AA genotype in an AMD patient population, suggesting future studies on the role VEGFR-2 SNPs.

  13. Coral-Derived Compound WA-25 Inhibits Angiogenesis by Attenuating the VEGF/VEGFR2 Signaling Pathway

    Directory of Open Access Journals (Sweden)

    Shih-Wei Lin

    2015-02-01

    Full Text Available Background: WA-25 (dihydroaustrasulfone alcohol, a synthetic derivative of marine compound WE-2 suppresses atherosclerosis in rats by reducing neointima formation. Because angiogenesis plays a critical role in the pathogenesis of atherosclerosis, the present study investigated the angiogenic function and mechanism of WA-25. Methods: The angiogenic effect of WA-25 was evaluated using a rat aortic ring assay and transgenic zebrafish models were established using transgenic Tg(fli-1:EGFPy1 and Tg(kdrl:mCherryci5-fli1a:negfpy7 zebrafish embryos. In addition, the effect of WA-25 on distinct angiogenic processes, including matrix metalloproteinase (MMP expression, endothelial cell proliferation and migration, as well as tube formation, was studied using human umbilical vein endothelial cells (HUVECs. The effect of WA-25 on the endothelial vascular endothelial growth factor (VEGF signaling pathway was elucidated using qRT-PCR, immunoblot analysis, immunofluorescence and flow cytometric analyses. Results: The application of WA-25 perturbed the development of intersegmental vessels in transgenic zebrafish. Moreover, WA-25 potently suppressed microvessel sprouting in organotypic rat aortic rings. Among cultured endothelial cells, WA-25 significantly and dose-dependently inhibited MMP-2/MMP-9 expression, proliferation, migration and tube formation in HUVECs. Mechanistic studies revealed that WA-25 significantly reduced the VEGF release by reducing VEGF expression at the mRNA and protein levels. In addition, WA-25 reduced surface VEGF receptor 2 (VEGFR2/Flk-1 expression by repressing the VEGFR2 mRNA level. Finally, an exogenous VEGF supply partially rescued the WA-25-induced angiogenesis blockage in vitro and in vivo. Conclusions: WA-25 is a potent angiogenesis inhibitor that acts through the down-regulation of VEGF and VEGFR2 in endothelial cells. General Significance: WA-25 may constitute a novel anti-angiogenic drug that acts by targeting endothelial

  14. Synthesis and preclinical evaluation of [{sup 11}C]PAQ as a PET imaging tracer for VEGFR-2

    Energy Technology Data Exchange (ETDEWEB)

    Samen, Erik; Stone-Elander, Sharon [Karolinska University Hospital Solna, Karolinska Pharmacy, Stockholm (Sweden); Karolinska Institutet, Clinical Neurosciences, Stockholm (Sweden); Thorell, Jan-Olov [Karolinska University Hospital Solna, Karolinska Pharmacy, Stockholm (Sweden); Lu, Li [Karolinska Institutet, Clinical Neurosciences, Stockholm (Sweden); Tegnebratt, Tetyana; Holmgren, Lars [Karolinska Institutet, Cancer Center Karolinska, Oncology-Pathology, Stockholm (Sweden)

    2009-08-15

    (R,S)-N-(4-Bromo-2-fluorophenyl)-6-methoxy-7-((1-methyl-3-piperidinyl)methoxy)-4-quinazolinamine (PAQ) is a tyrosine kinase inhibitor with high affinity for the vascular endothelial growth factor receptor 2 (VEGFR-2), which plays an important role in tumour angiogenesis. The aim of this work was to develop and evaluate in mice the {sup 11}C-labelled analogue as an in vivo tracer for VEGFR-2 expression in solid tumours. [{sup 11}C]PAQ was synthesized by an N-methylation of desmethyl-PAQ using [{sup 11}C]methyl iodide. The tracer's pharmacokinetic properties and its distribution in both subcutaneous and intraperitoneal tumour models were evaluated with positron emission tomography (PET). [{sup 18}F]FDG was used as a reference tracer for tumour growth. PET results were corroborated by ex vivo and in vitro phosphor imaging and immunohistochemical analyses. In vitro assays and PET in healthy animals revealed low tracer metabolism, limited excretion over 60 min and a saturable and irreversible binding. Radiotracer uptake in subcutaneous tumour masses was low, while focal areas of high uptake (up to 8% ID/g) were observed in regions connecting the tumour to the host. Uptake was similarly high but more distributed in tumours growing within the peritoneum. The pattern of radiotracer uptake was generally different from that of the metabolic tracer [{sup 18}F]FDG and correlated well with variations in VEGFR-2 expression determined ex vivo by immunohistochemical analysis. These results suggest that [{sup 11}C]PAQ has potential as a noninvasive PET tracer for in vivo imaging of VEGFR-2 expression in angiogenic ''hot spots''. (orig.)

  15. 1-Aryl-3-[4-(thieno[3,2-d]pyrimidin-4-yloxyphenyl]ureas as VEGFR-2 Tyrosine Kinase Inhibitors: Synthesis, Biological Evaluation, and Molecular Modelling Studies

    Directory of Open Access Journals (Sweden)

    Pedro Soares

    2013-01-01

    Full Text Available The vascular endothelial growth factor receptor-2 (VEGFR-2 is a tyrosine kinase receptor involved in the growth and differentiation of endothelial cells that are implicated in tumor-associated angiogenesis. In this study, novel 1-aryl-3-[4-(thieno[3,2-d]pyrimidin-4-yloxyphenyl]ureas were synthesized and evaluated for the VEGFR-2 tyrosine kinase inhibition. Three of these compounds showed good VEGFR-2 inhibition presenting low IC50 values (150–199 nM in enzymatic assays, showing also a significant proliferation inhibition of VEGF-stimulated human umbilical vein endothelial cells (HUVECs at low concentrations (0.5–1 µM, using the Bromodeoxyuridine (BrdU assay, not affecting cell viability. The determination of the total and phosphorylated (active VEGFR-2 was performed by western blot, and it was possible to conclude that the compounds significantly inhibit the phosphorylation of the receptor at 1 µM pointing to their antiproliferative mechanism of action in HUVECs. The molecular rationale for inhibiting the tyrosine kinase domain of VEGFR-2 was also performed and discussed using molecular docking studies.

  16. 1-Aryl-3-[4-(thieno[3,2-d]pyrimidin-4-yloxy)phenyl]ureas as VEGFR-2 Tyrosine Kinase Inhibitors: Synthesis, Biological Evaluation, and Molecular Modelling Studies

    Science.gov (United States)

    Soares, Pedro; Costa, Raquel; Froufe, Hugo J. C.; Calhelha, Ricardo C.; Peixoto, Daniela; Ferreira, Isabel C. F. R.; Abreu, Rui M. V.; Soares, Raquel; Queiroz, Maria-João R. P.

    2013-01-01

    The vascular endothelial growth factor receptor-2 (VEGFR-2) is a tyrosine kinase receptor involved in the growth and differentiation of endothelial cells that are implicated in tumor-associated angiogenesis. In this study, novel 1-aryl-3-[4-(thieno[3,2-d]pyrimidin-4-yloxy)phenyl]ureas were synthesized and evaluated for the VEGFR-2 tyrosine kinase inhibition. Three of these compounds showed good VEGFR-2 inhibition presenting low IC50 values (150–199 nM) in enzymatic assays, showing also a significant proliferation inhibition of VEGF-stimulated human umbilical vein endothelial cells (HUVECs) at low concentrations (0.5–1 µM), using the Bromodeoxyuridine (BrdU) assay, not affecting cell viability. The determination of the total and phosphorylated (active) VEGFR-2 was performed by western blot, and it was possible to conclude that the compounds significantly inhibit the phosphorylation of the receptor at 1 µM pointing to their antiproliferative mechanism of action in HUVECs. The molecular rationale for inhibiting the tyrosine kinase domain of VEGFR-2 was also performed and discussed using molecular docking studies. PMID:23936775

  17. Ultrasound molecular imaging of VEGFR2 in a rat prostate tumor model using BR55.

    Science.gov (United States)

    Tardy, Isabelle; Pochon, Sibylle; Theraulaz, Martine; Emmel, Patricia; Passantino, Lisa; Tranquart, François; Schneider, Michel

    2010-10-01

    To evaluate BR55, a new VEGFR2-specific ultrasound contrast agent, for imaging prostate tumors in an orthotopic model in the rat. Rat prostate adenocarcinoma were established by injection of G Dunning R-3327 tumor cells in one lobe of the prostate of Copenhagen rats. Imaging experiments were performed with BR55, SonoVue, and streptavidin-functionalized microbubbles coupled with an anti-vascular endothelial growth factor receptor 2 (VEGFR2) antibody using a clinical ultrasound scanner. Contrast enhancement in the tumor and healthy prostate was followed over time by intermittent imaging at low acoustic power. Signal quantification and statistical analysis were performed in the tumor and healthy tissue to compare the behavior of the 3 contrast agents. Immunohistochemistry was performed on the prostate and tumor specimen to determine the expression of VEGFR2. Comparable contrast enhancement was observed in tumors at peak intensity for BR55 and SonoVue. Then, once unbound microbubbles had cleared from the circulation, a strong enhancement of the tumor was obtained with BR55, whereas no significant microbubble accumulation was detected in the healthy prostate tissue. SonoVue microbubbles were rapidly eliminated, and no significant binding was observed in the tumor. The tumor to prostate ratio calculated after signal quantification was about 20 for the 3 doses of BR55 tested. The enhancement obtained with BR55 in the tumor was not significantly different from the one observed with antibody-coupled streptavidin microbubbles. Intense staining for VEGFR2 was detected in the tumor vessels by immunohistochemistry. This study showed that BR55 binding to prostate tumors resulted in a strong enhancement of the lesions as early as a few minutes after contrast injection, whereas minimal nonspecific accumulation occurred in the healthy part of the gland. BR55, like SonoVue, provide information on tissue perfusion during the early vascular phase, but BR55 binding to the tumoral

  18. VEGF-A isoforms program differential VEGFR2 signal transduction, trafficking and proteolysis

    Science.gov (United States)

    Fearnley, Gareth W.; Smith, Gina A.; Abdul-Zani, Izma; Yuldasheva, Nadira; Mughal, Nadeem A.; Homer-Vanniasinkam, Shervanthi; Kearney, Mark T.; Zachary, Ian C.; Tomlinson, Darren C.; Harrison, Michael A.; Wheatcroft, Stephen B.; Ponnambalam, Sreenivasan

    2016-01-01

    ABSTRACT Vascular endothelial growth factor A (VEGF-A) binding to the receptor tyrosine kinase VEGFR2 triggers multiple signal transduction pathways, which regulate endothelial cell responses that control vascular development. Multiple isoforms of VEGF-A can elicit differential signal transduction and endothelial responses. However, it is unclear how such cellular responses are controlled by isoform-specific VEGF-A–VEGFR2 complexes. Increasingly, there is the realization that the membrane trafficking of receptor–ligand complexes influences signal transduction and protein turnover. By building on these concepts, our study shows for the first time that three different VEGF-A isoforms (VEGF-A165, VEGF-A121 and VEGF-A145) promote distinct patterns of VEGFR2 endocytosis for delivery into early endosomes. This differential VEGFR2 endocytosis and trafficking is linked to VEGF-A isoform-specific signal transduction events. Disruption of clathrin-dependent endocytosis blocked VEGF-A isoform-specific VEGFR2 activation, signal transduction and caused substantial depletion in membrane-bound VEGFR1 and VEGFR2 levels. Furthermore, such VEGF-A isoforms promoted differential patterns of VEGFR2 ubiquitylation, proteolysis and terminal degradation. Our study now provides novel insights into how different VEGF-A isoforms can bind the same receptor tyrosine kinase and elicit diverse cellular outcomes. PMID:27044325

  19. VEGF-A isoforms program differential VEGFR2 signal transduction, trafficking and proteolysis

    Directory of Open Access Journals (Sweden)

    Gareth W. Fearnley

    2016-05-01

    Full Text Available Vascular endothelial growth factor A (VEGF-A binding to the receptor tyrosine kinase VEGFR2 triggers multiple signal transduction pathways, which regulate endothelial cell responses that control vascular development. Multiple isoforms of VEGF-A can elicit differential signal transduction and endothelial responses. However, it is unclear how such cellular responses are controlled by isoform-specific VEGF-A–VEGFR2 complexes. Increasingly, there is the realization that the membrane trafficking of receptor–ligand complexes influences signal transduction and protein turnover. By building on these concepts, our study shows for the first time that three different VEGF-A isoforms (VEGF-A165, VEGF-A121 and VEGF-A145 promote distinct patterns of VEGFR2 endocytosis for delivery into early endosomes. This differential VEGFR2 endocytosis and trafficking is linked to VEGF-A isoform-specific signal transduction events. Disruption of clathrin-dependent endocytosis blocked VEGF-A isoform-specific VEGFR2 activation, signal transduction and caused substantial depletion in membrane-bound VEGFR1 and VEGFR2 levels. Furthermore, such VEGF-A isoforms promoted differential patterns of VEGFR2 ubiquitylation, proteolysis and terminal degradation. Our study now provides novel insights into how different VEGF-A isoforms can bind the same receptor tyrosine kinase and elicit diverse cellular outcomes.

  20. Anti-tumor effects of a human VEGFR-2-based DNA vaccine in mouse models

    OpenAIRE

    XIE, KE; Bai, Rui-Zhen; Wu, Yang; Liu, Quan; Liu,Kang; Wei, Yu-Quan

    2009-01-01

    Background Vascular endothelial growth factor (VEGF) and its receptor, VEGFR-2 (Flk-1/KDR), play a key role in tumor angiogenesis. Blocking the VEGF-VEGFR-2 pathway may inhibit tumor growth. Here, we used human VEGFR-2 as a model antigen to explore the feasibility of immunotherapy with a plasmid DNA vaccine based on a xenogeneic homologue of this receptor. Methods The protective effects and therapeutic anti-tumor immunity mediated by the DNA vaccine were investigated in mouse models. Anti-ang...

  1. VEGFR2 Functions As an H2S-Targeting Receptor Protein Kinase with Its Novel Cys1045–Cys1024 Disulfide Bond Serving As a Specific Molecular Switch for Hydrogen Sulfide Actions in Vascular Endothelial Cells

    Science.gov (United States)

    Tao, Bei-Bei; Liu, Shu-Yuan; Zhang, Cai-Cai; Fu, Wei; Cai, Wen-Jie; Wang, Yi; Shen, Qing; Wang, Ming-Jie; Chen, Ying; Zhang, Li-Jia; Zhu, Yi-Zhun

    2013-01-01

    Abstract Aims: The potential receptor for hydrogen sulfide (H2S) remains unknown. Results: H2S could directly activate vascular endothelial growth factor receptor 2 (VEGFR2) and that a small interfering RNA (siRNA)-mediated knockdown of VEGFR2 inhibited H2S-induced migration of human vascular endothelial cells. H2S promoted angiogenesis in Matrigel plug assay in mice and this effect was attenuated by a VEGF receptor inhibitor. Using tandem mass spectrometry (MS), we identified a new disulfide complex located between Cys1045 and Cys1024 within VEGFR2 that was labile to H2S-mediated modification. Kinase activity of the mutant VEGFR2 (C1045A) devoid of the Cys1045–Cys1024 disulfide bond was significantly higher than wild-type VEGFR2. Transfection with vectors expressing VEGFR2 (C1045A) caused a significant increase in cell migration, while the migration-promoting effect of H2S disappeared in the cells transfected with VEGFR2 (C1045A). Therefore, the Cys1045–Cys1024 disulfide bond serves as an intrinsic inhibitory motif and functions as a molecular switch for H2S. The formation of the Cys1045–Cys1024 disulfide bond disrupted the integrity of the active conformation of VEGFR2. Breaking the Cys1045–Cys1024 disulfide bond recovered the active conformation of VEGFR2. This motif was prone to a nucleophilic attack by H2S via an interaction of their frontier molecular orbitals. siRNA-mediated knockdown of cystathionine γ-lyase attenuated migration of vascular endothelial cells induced by VEGF or moderate hypoxia. Innovation and Conclusion: The study provides the first piece of evidence of a molecular switch in H2S-targeting receptor protein kinase in H2S-induced angiogenesis and that may be applicable to additional kinases containing functionally important disulfide bonds in mediating various H2S actions. Antioxid. Redox Signal. 19, 448–464. PMID:23199280

  2. Clopidogrel inhibits angiogenesis of gastric ulcer healing via downregulation of vascular endothelial growth factor receptor 2.

    Science.gov (United States)

    Luo, Jiing-Chyuan; Peng, Yen-Ling; Chen, Tseng-Shing; Huo, Teh-Ia; Hou, Ming-Chih; Huang, Hui-Chun; Lin, Han-Chieh; Lee, Fa-Yauh

    2016-09-01

    Although clopidogrel does not cause gastric mucosal injury, it does not prevent peptic ulcer recurrence in high-risk patients. We explored whether clopidogrel delays gastric ulcer healing via inhibiting angiogenesis and to elucidate the possible mechanisms. Gastric ulcers were induced in Sprague Dawley rats, and ulcer healing and angiogenesis of ulcer margin were compared between clopidogrel-treated rats and controls. The expressions of the proangiogenic growth factors and their receptors including basic fibroblast growth factor (bFGF), bFGF receptor (FGFR), vascular endothelial growth factor (VEGF), VEGFR1, VEGFR2, platelet-derived growth factor (PDGF)A, PDGFB, PDGFR A, PDGFR B, and phosphorylated form of mitogenic activated protein kinase pathways over the ulcer margin were compared via western blot and reverse transcription polymerase chain reaction. In vitro, human umbilical vein endothelial cells (HUVECs) were used to elucidate how clopidogrel inhibited growth factors-stimulated HUVEC proliferation. The ulcer sizes were significantly larger and the angiogenesis of ulcer margin was significantly diminished in the clopidogrel (2 and 10 mg/kg/d) treated groups. Ulcer induction markedly increased the expression of phosphorylated form of extracellular signal-regulated kinase (pERK), FGFR2, VEGF, VEGFR2, and PDGFRA when compared with those of normal mucosa. Clopidogrel treatment significantly decreased pERK, FGFR2, VEGF, VEGFR2, and PDGFRA expression at the ulcer margin when compared with those of the respective control group. In vitro, clopidogrel (10(-6)M) inhibited VEGF-stimulated (20 ng/mL) HUVEC proliferation, at least, via downregulation of VEGFR2 and pERK. Clopidogrel inhibits the angiogenesis of gastric ulcer healing at least partially by the inhibition of the VEGF-VEGFR2-ERK signal transduction pathway. Copyright © 2015. Published by Elsevier B.V.

  3. Coordinated Activation of VEGF/VEGFR-2 and PPARδ Pathways by a Multi-Component Chinese Medicine DHI Accelerated Recovery from Peripheral Arterial Disease in Type 2 Diabetic Mice

    Science.gov (United States)

    He, Shuang; Zhao, Tiechan; Guo, Hao; Meng, Yanzhi; Qin, Gangjian; Goukassian, David A.; Han, Jihong; Gao, Xuimei; Zhu, Yan

    2016-01-01

    Diabetic mellitus (DM) patients are at an increased risk of developing peripheral arterial disease (PAD). Danhong injection (DHI) is a Chinese patent medicine widely used for several cardiovascular indications but the mechanism of action is not well-understood. We investigated the therapeutic potential of DHI on experimental PAD in mice with chemically induced as well as genetic (KKAy) type 2 DM and the overlapping signaling pathways regulating both therapeutic angiogenesis and glucose homeostasis. Compared with normal genetic background wild type (WT) mice, both DM mice showed impaired perfusion recovery in hind-limb ischemia (HLI) model. DHI treatment significantly accelerated perfusion recovery, lowered blood glucose and improved glucose tolerance in both DM models. Bioluminescent imaging demonstrated a continuous ischemia-induced vascular endothelial growth factor receptor 2 (VEGFR-2) gene expressions with a peak time coincident with the maximal DHI stimulation. Flow cytometry analysis showed a DHI-mediated increase in endothelial progenitor cell (EPC) mobilization from bone marrow to circulating peripheral blood. DHI administration upregulated the expression of vascular endothelial growth factor A (VEGF-A) and VEGF receptor-2 (VEGFR-2) in ischemic muscle. A cross talk between ischemia-induced angiogenesis and glucose tolerance pathways was analyzed by Ingenuity Pathway Analysis (IPA) which suggested an interaction of VEGF-A/VEGFR-2 and peroxisome proliferator-activated receptor δ (PPARδ)/peroxisome proliferator-activated receptor γ (PPARγ) genes. We confirmed that upregulation of VEGF-A/VEGFR-2 by DHI promoted PPARδ gene expression in both type 2 diabetic mice. Our findings demonstrated that a multi-component Chinese medicine DHI effectively increased blood flow recovery after tissue ischemia in diabetic mice by promoting angiogenesis and improving glucose tolerance through a concomitant activation of VEGF-A/VEGFR-2 and PPARδ signaling pathways. PMID

  4. Decreased expression of CHIP leads to increased angiogenesis via VEGF-VEGFR2 pathway and poor prognosis in human renal cell carcinoma.

    Science.gov (United States)

    Sun, Chao; Li, Hai-long; Chen, Hai-rong; Shi, Mei-lin; Liu, Qing-hua; Pan, Zhen-qiang; Bai, Jin; Zheng, Jun-nian

    2015-05-29

    CHIP (c-terminal Hsp70-interacting protein) is an E3 ligase which may play different roles in different cancers. The elucidation of the VHL-HIF-1α (hypoxia inducible factor-1α)-VEGF (vascular endothelial growth factor) pathway has led to the development of targeted therapy in renal cell carcinoma (RCC). However, little is known about the role of CHIP and the relationship between CHIP and VEGF-VEGFR2 (VEGF receptor 2) pathway in RCC. In this study, we found that the expression of CHIP was downregulated and significantly correlated with pT status (P = 0.022) and TNM stage (P = 0.022) in 304 RCC and 35 normal renal tissues using tissue microarray. Moreover, low expression of CHIP is a strong and independent negative prognostic value for RCC. In vitro, CHIP negatively regulated RCC cell migration, invasion and angiogenesis. In addition, ELISA tests showed that restoration of CHIP inhibited, while knockdown promoted, the secreted level of VEGF. Furthermore, western blot indicated that the VEGFR2 protein level was reduced after CHIP overexpression. Our findings demonstrate for the first time that CHIP may be involved in RCC angiogenesis through regulating VEGF secretion and expression of VEGFR2. CHIP may serve as promising prognostic biomarker of angiogenesis and may constitute a potential therapeutic target in RCC.

  5. Olive oil compounds inhibit vascular endothelial growth factor receptor-2 phosphorylation

    Energy Technology Data Exchange (ETDEWEB)

    Lamy, Sylvie, E-mail: lamy.sylvie@uqam.ca; Ouanouki, Amira; Béliveau, Richard; Desrosiers, Richard R.

    2014-03-10

    Vascular endothelial growth factor (VEGF) triggers crucial signaling processes that regulate tumor angiogenesis and, therefore, represents an attractive target for the development of novel anticancer therapeutics. Several epidemiological studies have confirmed that abundant consumption of foods from plant origin is associated with reduced risk of developing cancers. In the Mediterranean basin, the consumption of extra virgin olive oil is an important constituent of the diet. Compared to other vegetable oils, the presence of several phenolic antioxidants in olive oil is believed to prevent the occurrence of a variety of pathological processes, such as cancer. While the strong antioxidant potential of these molecules is well characterized, their antiangiogenic activities remain unknown. The aim of this study is to investigate whether tyrosol (Tyr), hydroxytyrosol (HT), taxifolin (Tax), oleuropein (OL) and oleic acid (OA), five compounds contained in extra virgin olive oil, can affect in vitro angiogenesis. We found that HT, Tax and OA were the most potent angiogenesis inhibitors through their inhibitory effect on specific autophosphorylation sites of VEGFR-2 (Tyr951, Tyr1059, Tyr1175 and Tyr1214) leading to the inhibition of endothelial cell (EC) signaling. Inhibition of VEGFR-2 by these olive oil compounds significantly reduced VEGF-induced EC proliferation and migration as well as their morphogenic differentiation into capillary-like tubular structures in Matrigel. Our study demonstrates that HT, Tax and OA are novel and potent inhibitors of the VEGFR-2 signaling pathway. These findings emphasize the chemopreventive properties of olive oil and highlight the importance of nutrition in cancer prevention. - Highlights: • We investigated five compounds contained in extra virgin olive oil on angiogenesis. • Hydroxytyrosol, taxifolin and oleic acid are the best angiogenesis inhibitors. • Olive oil compounds affect endothelial cell functions essential for

  6. Etk/Bmx transactivates vascular endothelial growth factor 2 and recruits phosphatidylinositol 3-kinase to mediate the tumor necrosis factor-induced angiogenic pathway.

    Science.gov (United States)

    Zhang, Rong; Xu, Yingqian; Ekman, Niklas; Wu, Zhenhua; Wu, Jiong; Alitalo, Kari; Min, Wang

    2003-12-19

    Tumor necrosis factor (TNF), via its receptor 2 (TNFR2), induces Etk (or Bmx) activation and Etk-dependent endothelial cell (EC) migration and tube formation. Because TNF receptor 2 lacks an intrinsic kinase activity, we examined the kinase(s) mediating TNF-induced Etk activation. TNF induces a coordinated phosphorylation of vascular endothelial growth factor (VEGF) receptor 2 (VEGFR2) and Etk, which is blocked by VEGFR2-specific inhibitors. In response to TNF, Etk and VEGFR2 form a complex resulting in a reciprocal activation between the two kinases. Subsequently, the downstream phosphatidylinositol 3-kinase (PI3K)-Akt signaling (but not signaling through phospholipase C-gamma) was initiated and directly led to TNF-induced EC migration, which was significantly inhibited by VEGFR2-, PI3K-, or Akt-specific inhibitors. Phosphorylation of VEGFR2 at Tyr-801 and Tyr-1175, the critical sites for VEGF-induced PI3K-Akt signaling, was not involved in TNF-mediated Akt activation. However, TNF induces phosphorylation of Etk at Tyr-566, directly mediating the recruitment of the p85 subunit of PI3K. Furthermore, TNF- but not VEGF-induced activation of VEGFR2, Akt, and EC migration are blunted in EC genetically deficient with Etk. Taken together, our data demonstrated that TNF induces transactivation between Etk and VEGFR2, and Etk directly activates PI3K-Akt angiogenic signaling independent of VEGF-induced VEGFR2-PI3K-Akt signaling pathway.

  7. Clinical significance of VEGFR-2 and {sup 18}F-FDG PET/CT SUVmax pretreatment score in predicting the long-term outcome of patients with locally advanced rectal cancer treated with neoadjuvant therapy

    Energy Technology Data Exchange (ETDEWEB)

    Sole, Claudio V. [Hospital General Universitario Gregorio Maranon, Department of Oncology, Madrid (Spain); School of Medicine Complutense University, Madrid (Spain); Hospital General Universitario Gregorio Maranon, Institute for Sanitary Research, Madrid (Spain); Hospital General Universitario Gregorio Maranon, Madrid (Spain); Calvo, Felipe A. [Hospital General Universitario Gregorio Maranon, Department of Oncology, Madrid (Spain); School of Medicine Complutense University, Madrid (Spain); Hospital General Universitario Gregorio Maranon, Institute for Sanitary Research, Madrid (Spain); Alvarez, Emilio; Peligros, Isabel [School of Medicine Complutense University, Madrid (Spain); Hospital General Universitario Gregorio Maranon, Department of Pathology, Madrid (Spain); Hospital General Universitario Gregorio Maranon, Institute for Sanitary Research, Madrid (Spain); Garcia-Alfonso, Pilar [Hospital General Universitario Gregorio Maranon, Service of Medical Oncology, Madrid (Spain); Hospital General Universitario Gregorio Maranon, Institute for Sanitary Research, Madrid (Spain); Ferrer, Carlos; Ochoa, Enrique [Hospital Provincial de Castellon, Institute of Oncology, Castellon de la Plana (Spain); Herranz, Rafael [Hospital General Universitario Gregorio Maranon, Service of Radiation Oncology, Madrid (Spain); Hospital General Universitario Gregorio Maranon, Institute for Sanitary Research, Madrid (Spain); Carreras, Jose L. [School of Medicine Complutense University, Madrid (Spain); Hospital General Universitario Gregorio Maranon, Department of Radiology and Medical Physics, Madrid (Spain)

    2013-10-15

    Vascular endothelial growth factor receptor-2 (VEGFR-2), epidermal growth factor receptor-1 (EGFR), and cyclooxygenase-2 (COX-2) stimulate key processes involved in tumor progression and are important targets for cancer drugs. {sup 18}F-FDG maximum standardized uptake value (SUVmax) is a marker of tumor metabolic activity. The purpose of this study was to measure SUVmax combined with VEGFR-2, EGFR and COX-2 proteins in pretreatment tumor biopsies from patients with locally advanced rectal cancer receiving intensive neoadjuvant treatment and to correlate the findings with clinical outcome. VEGFR-2, EGFR and COX-2 were measured using the immunoreactive score (IRS). SUVmax (median 8.4) was quantified in tumors with molecular overexpression (IRS {>=}3 + SUVmax {>=} 8.4 indicating active tumors; SUVmax <8.4 indicating inactive tumors). The Cox proportional hazards model was used to explore associations between tumor markers, disease-free survival (DFS) and overall survival (OS). The study group comprised 38 patients with a median follow-up of 69.3 months (range 4.5 - 92 months). Multivariate analysis showed that active tumors (overexpressing VEGFR-2, high SUVmax) were associated with worse DFS (HR 4.73, 95 % CI 1.18 - 22.17; p = 0.04) and OS (HR 4.28, 95 % CI 1.04 - 20.12; p = 0.05). Active tumors overexpressing VEGFR-2 are associated with a worse overall outcome in patients with rectal cancer treated with induction chemotherapy followed by pelvic chemoradiation and surgery. The optimal diagnostic cut-off level for this novel biomarker association should be investigated. Evaluation in a clinical trial is required to determine whether selected patients could benefit from a VEGFR-targeting drug. (orig.)

  8. Neuropilin-1 forms complexes with vascular endothelial growth factor receptor-2 during megakaryocytic differentiation of UT-7/TPO cells

    Energy Technology Data Exchange (ETDEWEB)

    Ohsaka, Akimichi, E-mail: ohsaka@juntendo.ac.jp [Department of Transfusion Medicine and Stem Cell Regulation, Juntendo University School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421 (Japan); Hirota-Komatsu, Satoko; Shibata, Miki [Department of Transfusion Medicine and Stem Cell Regulation, Juntendo University School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421 (Japan); Komatsu, Norio [Department of Hematology, Juntendo University School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421 (Japan)

    2009-12-25

    We investigated whether the gene expression of vascular endothelial growth factor (VEGF) and its receptors (VEGFR and neuropilin-1 [NRP-1]) could be specifically regulated during the megakaryocytic differentiation of human thrombopoietin (TPO)-dependent UT-7/TPO cells. Undifferentiated UT-7/TPO cells expressed a functional VEGFR-2, leading to VEGF binding and VEGF{sub 165}-induced tyrosine phosphorylation, cell proliferation, and apoptosis inhibition. The megakaryocytic differentiation of UT-7/TPO cells on treatment with phorbol myristate acetate (PMA) was accompanied by a marked up-regulation of NRP-1 mRNA and protein expression and by an increase in VEGF-binding activity, which was mainly mediated by VEGFR-2. VEGF{sub 165} promoted the formation of complexes containing NRP-1 and VEGFR-2 in undifferentiated UT-7/TPO cells in a dose-dependent manner. Unlike human umbilical vein endothelial cells, PMA-differentiated UT-7/TPO cells exhibited complex formation between NRP-1 and VEGFR-2 even in the absence of VEGF{sub 165}. These findings suggest that NRP-1-VEGFR-2-complex formation may contribute to effective cellular functions mediated by VEGF{sub 165} in megakaryocytic cells.

  9. Neuropilin-1 forms complexes with vascular endothelial growth factor receptor-2 during megakaryocytic differentiation of UT-7/TPO cells.

    Science.gov (United States)

    Ohsaka, Akimichi; Hirota-Komatsu, Satoko; Shibata, Miki; Komatsu, Norio

    2009-12-25

    We investigated whether the gene expression of vascular endothelial growth factor (VEGF) and its receptors (VEGFR and neuropilin-1 [NRP-1]) could be specifically regulated during the megakaryocytic differentiation of human thrombopoietin (TPO)-dependent UT-7/TPO cells. Undifferentiated UT-7/TPO cells expressed a functional VEGFR-2, leading to VEGF binding and VEGF(165)-induced tyrosine phosphorylation, cell proliferation, and apoptosis inhibition. The megakaryocytic differentiation of UT-7/TPO cells on treatment with phorbol myristate acetate (PMA) was accompanied by a marked up-regulation of NRP-1 mRNA and protein expression and by an increase in VEGF-binding activity, which was mainly mediated by VEGFR-2. VEGF(165) promoted the formation of complexes containing NRP-1 and VEGFR-2 in undifferentiated UT-7/TPO cells in a dose-dependent manner. Unlike human umbilical vein endothelial cells, PMA-differentiated UT-7/TPO cells exhibited complex formation between NRP-1 and VEGFR-2 even in the absence of VEGF(165). These findings suggest that NRP-1-VEGFR-2-complex formation may contribute to effective cellular functions mediated by VEGF(165) in megakaryocytic cells.

  10. Novel angiogenesis inhibitory activity in cinnamon extract blocks VEGFR2 kinase and downstream signaling.

    Science.gov (United States)

    Lu, Jianming; Zhang, Keqiang; Nam, Sangkil; Anderson, Richard A; Jove, Richard; Wen, Wei

    2010-03-01

    As a critical factor in the induction of angiogenesis, vascular endothelial growth factor (VEGF) has become an attractive target for anti-angiogenesis treatment. However, the side effects associated with most anti-VEGF agents limit their chronic use. Identification of naturally occurring VEGF inhibitors derived from diet is a potential alternative approach, with the advantage of known safety. To isolate natural inhibitors of VEGF, we established an in vitro tyrosine kinase assay to screen for diet-based agents that suppress VEGFR2 kinase activity. We found that a water-based extract from cinnamon (cinnamon extract, CE), one of the oldest and most popular spices, was a potent inhibitor of VEGFR2 kinase activity, directly inhibiting kinase activity of purified VEGFR2 as well as mitogen-activated protein kinase- and Stat3-mediated signaling pathway in endothelial cells. As a result, CE inhibited VEGF-induced endothelial cell proliferation, migration and tube formation in vitro, sprout formation from aortic ring ex vivo and tumor-induced blood vessel formation in vivo. Depletion of polyphenol from CE with polyvinylpyrrolidone abolished its anti-angiogenesis activity. While cinnamaldehyde, a component responsible for CE aroma, had little effect on VEGFR2 kinase activity, high-performance liquid chromatography-purified components of CE, procyanidin type A trimer (molecular weight, 864) and a tetramer (molecular weight, 1152) were found to inhibit kinase activity of purified VEGFR2 and VEGFR2 signaling, implicating procyanidin oligomers as active components in CE that inhibit angiogenesis. Our data revealed a novel activity in cinnamon and identified a natural VEGF inhibitor that could potentially be useful in cancer prevention and/or treatment.

  11. VEGFR1 and VEGFR2 involvement in extracellular galectin-1- and galectin-3-induced angiogenesis.

    Directory of Open Access Journals (Sweden)

    Nicky D'Haene

    Full Text Available AIM: Accumulating evidence suggests that extracellular galectin-1 and galectin-3 promote angiogenesis. Increased expression of galectin-1 and/or galectin-3 has been reported to be associated with tumour progression. Thus, it is critical to identify their influence on angiogenesis. METHODS: We examined the individual and combined effects of galectin-1 and galectin-3 on endothelial cell (EC growth and tube formation using two EC lines, EA.hy926 and HUVEC. The activation of vascular endothelial growth factor receptors (VEGFR1 and VEGFR2 was determined by ELISA and Western blots. We evaluated the VEGFR1 and VEGFR2 levels in endosomes by proximity ligation assay. RESULTS: We observed different responses to exogenous galectins depending on the EC line. An enhanced effect on EA.hy926 cell growth and tube formation was observed when both galectins were added together. Focusing on this enhanced effect, we observed that together galectins induced the phosphorylation of both VEGFR1 and VEGFR2, whereas galectin-1 and -3 alone induced VEGFR2 phosphorylation only. In the same way, the addition of a blocking VEGFR1 antibody completely abolished the increase in tube formation induced by the combined addition of both galectins. In contrast, the addition of a blocking VEGFR2 antibody only partially inhibited this effect. Finally, the addition of both galectins induced a decrease in the VEGFR1 and VEGFR2 endocytic pools, with a significantly enhanced effect on the VEGFR1 endocytic pool. These results suggest that the combined action of galectin-1 and galectin-3 has an enhanced effect on angiogenesis via VEGFR1 activation, which could be related to a decrease in receptor endocytosis.

  12. Development and evaluation of a novel VEGFR2-targeted nanoscale ultrasound contrast agents

    Science.gov (United States)

    Yu, Houqiang; Li, Chunfang; He, Xiaoling; Zhou, Qibing; Ding, Mingyue

    2016-04-01

    Recent literatures have reported that the targeted nanoscale ultrasound contrast agents are becoming more and more important in medical application, like ultrasound imaging, detection of perfusion, drug delivery and molecular imaging and so on. In this study, we fabricated an uniform nanoscale bubbles (257 nm with the polydispersity index of 0.458) by incorporation of antibody targeted to vascular endothelial growth factor receptor 2 (VEGFR2) into the nanobubbles membrane by using avidin-biotin interaction. Some fundamental characterizations such as nanobubble suspension, surface morphology, particle size distribution and zeta potential were investigated. The concentration and time-intensity curves (TICs) were obtained with a self-made ultrasound experimental setup in vitro evaluation. In addition, in order to evaluate the contrast enhancement ability and the potential tumor-targeted ability in vivo, normal Wistar rats and nude female BALB/c mice were intravascular administration of the nanobubbles via tail vein injection, respectively. Significant contrast enhancement of ultrasound imaging within liver and tumor were visualized. These experiments demonstrated that the targeted nanobubbles is efficient in ultrasound molecular imaging by enhancement of the contrast effect and have potential capacity for targeted tumor diagnosis and therapy in the future.

  13. Pristimerin, a Triterpenoid, Inhibits Tumor Angiogenesis by Targeting VEGFR2 Activation

    Directory of Open Access Journals (Sweden)

    Luyong Zhang

    2012-06-01

    Full Text Available Pristimerin is a triterpenoid isolated from Celastrus and Maytenus spp. that has been shown to possess a variety of biological activities, including anti-cancer activity. However, little is known about pristimerin’s effects on tumor angiogenesis. In this study, we examined the function and the mechanism of this compound in tumor angiogenesis using multiple angiogenesis assays. We found that pristimerin significantly reduced both the volume and weight of solid tumors and decreased angiogenesis in a xenograft mouse tumor model in vivo. Pristimerin significantly inhibited the neovascularization of chicken chorioallantoic membrane (CAM in vivo and abrogated vascular endothelial growth factor (VEGF-induced microvessel sprouting in an ex vivo rat aortic ring assay. Furthermore, pristimerin inhibited the VEGF-induced proliferation, migration and capillary-like structure formation of human umbilical vascular endothelial cells (HUVECs in a concentration-dependent manner. Mechanistic studies revealed that pristimerin suppressed the VEGF-induced phosphorylation of VEGF receptor 2 kinase (KDR/Flk-1 and the activity of AKT, ERK1/2, mTOR, and ribosomal protein S6 kinase. Taken together, our results provide evidence for the first time that pristimerin potently suppresses angiogenesis by targeting VEGFR2 activation. These results provide a novel mechanism of action for pristimerin which may be important in the treatment of cancer.

  14. Hypertensive stretch regulates endothelial exocytosis of Weibel-Palade bodies through VEGF receptor 2 signaling pathways

    Institute of Scientific and Technical Information of China (English)

    Yan Xiong; Zhenqian Hu; Xiaofan Han; Beibei Jiang; Rongli Zhang; Xiaoyu Zhang; Yao Lu

    2013-01-01

    Regulated endothelial exocytosis of Weibel-Palade bodies (WPBs),the first stage in leukocyte trafficking,plays a pivotal role in inflammation and injury.Acute mechanical stretch has been closely associated with vascular inflammation,although the precise mechanism is unknown.Here,we show that hypertensive stretch regulates the exocytosis of WPBs of endothelial ceils (ECs) through VEGF receptor 2 (VEGFR2) signaling pathways.Stretch triggers a rapid release (within minutes) of von Willebrand factor and interleukin-8 from WPBs in cultured human ECs,promoting the interaction between leukocytes and ECs through the translocation of P-selectin to the cell membrane.We further show that hypertensive stretch significantly induces P-selectin translocation of intact ECs and enhances leukocyte adhesion both ex vivo and in vivo.Stretch-induced endothelial exocytosis is mediated via a VEGFR2/PLCy1/calcium pathway.Interestingly,stretch also induces a negative feedback via a VEGFR2/Akt/nitric oxide pathway.Such dual effects are confirmed using pharmacological and genetic approaches in carotid artery segments,as well as in acute hypertensive mouse models.These studies reveal mechanical stretch as a potent agonist for endothelial exocytosis,which is modulated by VEGFR2 signaling.Thus,VEGFR2 signaling pathways may represent novel therapeutic targets in limiting hypertensive stretch-related inflammation.

  15. Hypertensive stretch regulates endothelial exocytosis of Weibel-Palade bodies through VEGF receptor 2 signaling pathways.

    Science.gov (United States)

    Xiong, Yan; Hu, Zhenqian; Han, Xiaofan; Jiang, Beibei; Zhang, Rongli; Zhang, Xiaoyu; Lu, Yao; Geng, Chenyang; Li, Wei; He, Yulong; Huo, Yingqing; Shibuya, Masabumi; Luo, Jincai

    2013-06-01

    Regulated endothelial exocytosis of Weibel-Palade bodies (WPBs), the first stage in leukocyte trafficking, plays a pivotal role in inflammation and injury. Acute mechanical stretch has been closely associated with vascular inflammation, although the precise mechanism is unknown. Here, we show that hypertensive stretch regulates the exocytosis of WPBs of endothelial cells (ECs) through VEGF receptor 2 (VEGFR2) signaling pathways. Stretch triggers a rapid release (within minutes) of von Willebrand factor and interleukin-8 from WPBs in cultured human ECs, promoting the interaction between leukocytes and ECs through the translocation of P-selectin to the cell membrane. We further show that hypertensive stretch significantly induces P-selectin translocation of intact ECs and enhances leukocyte adhesion both ex vivo and in vivo. Stretch-induced endothelial exocytosis is mediated via a VEGFR2/PLCγ1/calcium pathway. Interestingly, stretch also induces a negative feedback via a VEGFR2/Akt/nitric oxide pathway. Such dual effects are confirmed using pharmacological and genetic approaches in carotid artery segments, as well as in acute hypertensive mouse models. These studies reveal mechanical stretch as a potent agonist for endothelial exocytosis, which is modulated by VEGFR2 signaling. Thus, VEGFR2 signaling pathways may represent novel therapeutic targets in limiting hypertensive stretch-related inflammation.

  16. The Effect of Bevacizumab on Human Malignant Melanoma Cells with Functional VEGF/VEGFR2 Autocrine and Intracrine Signaling Loops

    Directory of Open Access Journals (Sweden)

    Una Adamcic

    2012-07-01

    Full Text Available Receptors for the angiogenic factor VEGF are expressed by tumor cancer cells including melanoma, although their functionality remains unclear. Paired human melanoma cell lines WM115 and WM239 were used to investigate differences in expression and functionality of VEGF and VEGFR2 in vitro and in vivo with the anti-VEGF antibody bevacizumab. Both WM115 and WM239 cells expressed VEGF and VEGFR2, the levels of which were modulated by hypoxia. Detection of native and phosphorylated VEGFR2 in subcellular fractions under serum-free conditions showed the presence of a functional autocrine as well as intracrine VEGF/VEGFR2 signaling loops. Interestingly, treatment of WM115 and WM239 cells with increasing doses of bevacizumab (0–300 µg/ml in vitro did not show any significant inhibition of VEGFR2 phosphorylation. Small-molecule tyrosine kinase inhibitor, sunitinib, caused an inhibition of VEGFR2 phosphorylation in WM239 but not in WM115 cells. An increase in cell proliferation was observed in WM115 cells treated with bevacizumab, whereas sunitinib inhibited proliferation. When xenografted to immune-deficient mice, we found bevacizumab to be an effective antiangiogenic but not antitumorigenic agent for both cell lines. Because bevacizumab is unable to neutralize murine VEGF, this supports a paracrine angiogenic response. We propose that the failure of bevacizumab to generate an antitumorigenic effect may be related to its generation of enhanced autocrine/intracrine signaling in the cancer cells themselves. Collectively, these results suggest that, for cancers with intracrine VEGF/ VEGFR2 signaling loops, small-molecule inhibitors of VEGFR2 may be more effective than neutralizing antibodies at disease control.

  17. Photoactivatable Caged Prodrugs of VEGFR-2 Kinase Inhibitors

    Directory of Open Access Journals (Sweden)

    Boris Pinchuk

    2016-04-01

    Full Text Available In this study, we report on the design, synthesis, photokinetic properties and in vitro evaluation of photoactivatable caged prodrugs for the receptor tyrosine kinase VEGFR-2. Highly potent VEGFR-2 inhibitors 1 and 3 were caged by introduction of a photoremovable protecting group (PPG to yield the caged prodrugs 4 and 5. As expected, enzymatic and cellular proliferation assays showed dramatically diminished efficacy of caged prodrugs in vitro. Upon ultraviolet (UV irradiation of the prodrugs original inhibitory activity was completely restored and even distinctly reinforced, as was the case for the prodrug 4. The presented results are a further evidence for caging technique being an interesting approach in the protein kinase field. It could enable spatial and temporal control for the inhibition of VEGFR-2. The described photoactivatable prodrugs might be highly useful as biological probes for studying the VEGFR-2 signal transduction.

  18. Dietary compound isoliquiritigenin inhibits breast cancer neoangiogenesis via VEGF/VEGFR-2 signaling pathway.

    Science.gov (United States)

    Wang, Zhiyu; Wang, Neng; Han, Shouwei; Wang, Dongmei; Mo, Suilin; Yu, Linzhong; Huang, Hui; Tsui, Kamchuen; Shen, Jiangang; Chen, Jianping

    2013-01-01

    Angiogenesis is crucial for cancer initiation, development and metastasis. Identifying natural botanicals targeting angiogenesis has been paid much attention for drug discovery in recent years, with the advantage of increased safety. Isoliquiritigenin (ISL) is a dietary chalcone-type flavonoid with various anti-cancer activities. However, little is known about the anti-angiogenic activity of isoliquiritigenin and its underlying mechanisms. Herein, we found that ISL significantly inhibited the VEGF-induced proliferation of human umbilical vein endothelial cells (HUVECs) at non-toxic concentration. A series of angiogenesis processes including tube formation, invasion and migration abilities of HUVECs were also interrupted by ISL in vitro. Furthermore, ISL suppressed sprout formation from VEGF-treated aortic rings in an ex-vivo model. Molecular mechanisms study demonstrated that ISL could significantly inhibit VEGF expression in breast cancer cells via promoting HIF-1α (Hypoxia inducible factor-1α) proteasome degradation and directly interacted with VEGFR-2 to block its kinase activity. In vivo studies further showed that ISL administration could inhibit breast cancer growth and neoangiogenesis accompanying with suppressed VEGF/VEGFR-2 signaling, elevated apoptosis ratio and little toxicity effects. Molecular docking simulation indicated that ISL could stably form hydrogen bonds and aromatic interactions within the ATP-binding region of VEGFR-2. Taken together, our study shed light on the potential application of ISL as a novel natural inhibitor for cancer angiogenesis via the VEGF/VEGFR-2 pathway. Future studies of ISL for chemoprevention or chemosensitization against breast cancer are thus warranted.

  19. CD147 promotes liver fibrosis progression via VEGF-A/VEGFR2 signalling-mediated cross-talk between hepatocytes and sinusoidal endothelial cells.

    Science.gov (United States)

    Yan, Zhaoyong; Qu, Kai; Zhang, Jing; Huang, Qichao; Qu, Ping; Xu, Xinsen; Yuan, Peng; Huang, Xiaojun; Shao, Yongping; Liu, Chang; Zhang, Hongxin; Xing, Jinliang

    2015-10-01

    Although previous evidence indicates close involvement of CD147 in the pathogenesis of liver fibrosis, the underlying molecular mechanisms and its therapeutic value remain largely unknown. In the present study, we investigated the biological roles of CD147 in liver fibrosis and assessed its therapeutic value as a target molecule in the CCl4-induced liver fibrosis mouse model. We found that CD147 was highly expressed in both hepatocytes and SECs (sinusoidal endothelial cells) in fibrotic liver tissues. Additionally, it was significantly associated with the fibrosis stage. TGF-β1 (transforming growth factor β1) was found to be mainly responsible for the up-regulation of CD147. Bioinformatic and experimental data suggest a functional link between CD147 expression and VEGF-A (vascular endothelial growth factor A)/VEGR-2 (VEGF receptor 2) signalling-mediated angiogenesis in fibrotic liver tissues. Furthermore, we observed that the CD147-induced activation of the PI3K (phosphoinositide 3-kinase)/Akt signalling pathway promotes the production of VEGF-A in hepatocytes and expression of VEGFR-2 in SECs, which was found to enhance the angiogenic capability of SECs. Finally, our data indicate that blocking of CD147 using an mAb (monoclonal antibody) attenuated liver fibrosis progression via inhibition of VEGF-A/VEGFR-2 signalling and subsequent amelioration of microvascular abnormality in the CCl4-induced mouse model. Our findings suggest a novel functional mechanism that CD147 may promote liver fibrosis progression via inducing the VEGF-A/VEGFR-2 signalling pathway-mediated cross-talk between hepatocytes and SECs. New strategies based on the intervention of CD147 can be expected for prevention of liver fibrosis.

  20. Decreased expression of serum and microvascular vascular endothelial growth factor receptor-2 in meningococcal sepsis*.

    NARCIS (Netherlands)

    Flier, M. van der; Baerveldt, E.M.; Miedema, A.; Hartwig, N.G.; Hazelzet, J.A.; Emonts, M.; Groot, R. de; Prens, E.P.; Vught, A.J. van; Jansen, N.J.

    2013-01-01

    OBJECTIVES: To determine the skin microvessel expression of vascular endothelial growth factor receptor 2 and serum-soluble vascular endothelial growth factor receptor 2 levels in children with meningococcal sepsis. DESIGN: Observational study. SETTING: Two tertiary academic children hospital PICUs.

  1. Endothelial NADPH oxidase 4 mediates vascular endothelial growth factor receptor 2-induced intravitreal neovascularization in a rat model of retinopathy of prematurity.

    Science.gov (United States)

    Wang, Haibo; Yang, Zhihong; Jiang, Yanchao; Hartnett, M Elizabeth

    2014-01-01

    NADPH oxidase-generated reactive oxygen species (ROS) are implicated in angiogenesis. Isoforms of NADPH oxidase NOX1, NOX2, and NOX4 are reported to be expressed in endothelial cells (ECs). Of these, NOX1 and NOX2 have been reported to contribute to intravitreal neovascularization (IVNV) in oxygen-induced retinopathy (OIR) models. In this study, we tested the hypothesis that the isoform NOX4 in ECs contributed to vascular endothelial growth factor (VEGF)-induced angiogenesis and IVNV. Isoforms of NADPH oxidase MRNA were measured in several types of cultured vascular ecs: human retinal microvascular ECs (hRMVECs), choroidal ECs (CECs), and human umbilical vascular ECs (HUVECs) using real-time PCR. Newborn rat pups and dams were placed into an OIR model that cycled oxygen concentration between 50% and 10% every 24 h for 14 days, and then were placed in room air (RA) for an additional 4 days (rat OIR model). NOX4 expression in retinal lysates from the RA-raised pups at postnatal day 0 (P0), P14, and P18 was determined with western blots. STAT3 activation was determined as the ratio of phosphorylated STAT3 to total STAT3 with western blot analysis of retinal lysates from pups raised in RA or from the rat OIR model at P18. Semiquantitative assessment of the density of NOX4 colabeling with lectin-stained retinal ECs was determined by immunolabeling of retinal cryosections from P18 pups in OIR or in RA. In hRMVECs transfected with NOX4 siRNA and treated with VEGF or control, 1) ROS generation was measured using the 5-(and-6)-chloromethyl-2',7'-dichlorodihydrofluorescein diacetate, acetyl ester fluorescence assay and 2) phosphorylated VEGF receptor 2 and STAT3, and total VEGFR2 and STAT3 were measured in western blot analyses. VEGF-stimulated hRMVEC proliferation was measured following transfection with NOX4 siRNA or STAT3 siRNA, or respective controls. NOX4 was the most prevalent isoform of NADPH oxidase in vascular ECs. NOX4 expression in retinal lysates was

  2. Protease-Activated Receptor 2 Promotes Pro-Atherogenic Effects through Transactivation of the VEGF Receptor 2 in Human Vascular Smooth Muscle Cells

    Science.gov (United States)

    Indrakusuma, Ira; Romacho, Tania; Eckel, Jürgen

    2017-01-01

    Background: Obesity is associated with impaired vascular function. In the cardiovascular system, protease-activated receptor 2 (PAR2) exerts multiple functions such as the control of the vascular tone. In pathological conditions, PAR2 is related to vascular inflammation. However, little is known about the impact of obesity on PAR2 in the vasculature. Therefore, we explored the role of PAR2 as a potential link between obesity and cardiovascular diseases. Methods: C57BL/6 mice were fed with either a chow or a 60% high fat diet for 24 weeks prior to isolation of aortas. Furthermore, human coronary artery endothelial cells (HCAEC) and human coronary smooth muscle cells (HCSMC) were treated with conditioned medium obtained from in vitro differentiated primary human adipocytes. To investigate receptor interaction vascular endothelial growth factor receptor 2 (VEGFR2) was blocked by exposure to calcium dobesilate and a VEGFR2 neutralization antibody, before treatment with PAR2 activating peptide. Student's t-test or one-way were used to determine statistical significance. Results: Both, high fat diet and exposure to conditioned medium increased PAR2 expression in aortas and human vascular cells, respectively. In HCSMC, conditioned medium elicited proliferation as well as cyclooxygenase 2 induction, which was suppressed by the PAR2 antagonist GB83. Specific activation of PAR2 by the PAR2 activating peptide induced proliferation and cyclooxygenase 2 expression which were abolished by blocking the VEGFR2. Additionally, treatment of HCSMC with the PAR2 activating peptide triggered VEGFR2 phosphorylation. Conclusion: Under obesogenic conditions, where circulating levels of pro-inflammatory adipokines are elevated, PAR2 arises as an important player linking obesity-related adipose tissue inflammation to atherogenesis. We show for the first time that the underlying mechanisms of these pro-atherogenic effects involve a potential transactivation of the VEGFR2 by PAR2. PMID

  3. SKLB-287, a novel oral multikinase inhibitor of EGFR and VEGFR2, exhibits potent antitumor activity in LoVo colorectal tumor model.

    Science.gov (United States)

    Chen, X; Liu, Y; Yang, H-W; Zhou, S; Cheng, C; Zheng, M-W; Zhong, L; Fu, X-Y; Pan, Y-L; Ma, S; Tang, Y; Chen, Y-Z; Li, L-L; Yang, S-Y

    2014-01-01

    Colorectal cancer (CRC) is the third common cancer and most of the chemotherapies of CRC currently used often suffer limited efficacy and large side effects. Targeted small-molecule by anti-tumor drugs are thought a promising strategy for improving the efficacy and reducing the side effects. In this investigation, we report a novel multikinase inhibitor, termed SKLB-287, which was discovered by us recently. SKLB-287 could efficiently inhibit the activation of endothelial growth factor receptor (EGFR) and vascular endothelial growth factor receptor 2 (VEGFR2). It displayed very good anti-proliferative activity against LoVo CRC cells and considerable antiangiogenic potency in transgenic zebrafish embryos. Oral administration of SKLB-287 resulted in dose-dependent suppression of tumor growth in LoVo xenograft mouse model. Immunohistochemistry was adopted to examine the in vivo anti-tumor mechanism of action of SKLB-287.

  4. Anger Emotional Stress Influences VEGF/VEGFR2 and Its Induced PI3K/AKT/mTOR Signaling Pathway

    Directory of Open Access Journals (Sweden)

    Peng Sun

    2016-01-01

    Full Text Available Objective. We discuss the influence of anger emotional stress upon VEGF/VEGFR2 and its induced PI3K/AKT/mTOR signal pathway. Methods. We created a rat model of induced anger (anger-out and anger-in emotional response using social isolation and resident-intruder paradigms and assessed changes in hippocampus’ VEGF content, neuroplasticity, and the PI3K/AKT/mTOR signaling pathway. Results. The resident-intruder method successfully generated anger-out and anger-in models that differed significantly in composite aggression score, aggression incubation, open field behavior, sucrose preference, and weight gain. Anger emotional stress decreased synaptic connections and VEGFR2 expression. Anger emotional stress led to abnormal expression of VEGF/VEGFR2 mRNA and protein and disorderly expression of key factors in the PI3K/AKT/mTOR signal pathway. Fluoxetine administration ameliorated behavioral abnormalities and damage to hippocampal neurons caused by anger emotional stress, as well as abnormal expression of some proteins in VEGF/VEGFR2 and its induced PI3K/AKT/mTOR signal pathway. Conclusion. This research provides a detailed classification of anger emotion and verifies its influence upon VEGF and the VEGF-induced signaling pathway, thus providing circumstantial evidence of mechanisms by which anger emotion damages neurogenesis. As VEGFR2 can promote neurogenesis and vasculogenesis in the hippocampus and frontal lobe, these results suggest that anger emotional stress can result in decreased neurogenesis.

  5. Placental growth factor and vascular endothelial growth factor receptor-2 in human lung development.

    Science.gov (United States)

    Janér, Joakim; Andersson, Sture; Haglund, Caj; Karikoski, Riitta; Lassus, Patrik

    2008-08-01

    We examined the pulmonary expression of 2 proangiogenic factors, namely, placental growth factor and vascular endothelial growth factor receptor-2, during lung development and acute and chronic lung injury in newborn infants. Six groups were included in an immunohistochemical study of placental growth factor and vascular endothelial growth factor receptor-2, that is, 9 fetuses, 4 preterm and 8 term infants without lung injury who died soon after birth, 5 preterm infants with respiratory distress syndrome of 10 days, and 6 with bronchopulmonary dysplasia. Placental growth factor concentrations in tracheal aspirate fluid were measured in 70 samples from 20 preterm infants during the first postnatal week. In immunohistochemical analyses, placental growth factor staining was seen in bronchial epithelium and macrophages in all groups. Distal airway epithelium positivity was observed mostly in fetuses and in preterm infants who died soon after birth. Vascular endothelial growth factor receptor-2 staining was seen in vascular endothelium in all groups and also in lymphatic endothelium in fetuses. Vascular endothelial growth factor receptor-2 staining in arterial endothelium was associated with higher and staining in venous endothelium with lower gestational age. In capillaries, less vascular endothelial growth factor receptor-2 staining was seen in bronchopulmonary dysplasia. The mean placental growth factor protein concentration in tracheal aspirate fluid during the first postnatal week was 0.64 +/- 0.42 pg/mL per IgA-secretory component unit. Concentrations during the first postnatal week were stable. Lower placental growth factor concentrations correlated with chorioamnionitis and lactosyl ceramide positivity. The vascular endothelial growth factor receptor-2 staining pattern seems to reflect ongoing differentiation and activity of different endothelia. Lower vascular endothelial growth factor receptor-2 expression in capillary endothelium in bronchopulmonary dysplasia

  6. Targeting Extracellular Domains D4 and D7 of Vascular Endothelial Growth Factor Receptor 2 Reveals Allosteric Receptor Regulatory Sites

    OpenAIRE

    Hyde, Caroline A. C.; Giese, Alexandra; Stuttfeld, Edward; Abram Saliba, Johan; Villemagne, Denis; Schleier, Thomas; Binz, H. Kaspar; Ballmer-Hofer, Kurt

    2012-01-01

    Vascular endothelial growth factors (VEGFs) activate three receptor tyrosine kinases, VEGFR-1, -2, and -3, which regulate angiogenic and lymphangiogenic signaling. VEGFR-2 is the most prominent receptor in angiogenic signaling by VEGF ligands. The extracellular part of VEGF receptors consists of seven immunoglobulin homology domains (Ig domains). Earlier studies showed that domains 2 and 3 (D23) mediate ligand binding, while structural analysis of dimeric ligand/receptor complexes by electron...

  7. Tryptanthrin inhibits angiogenesis by targeting the VEGFR2-mediated ERK1/2 signalling pathway.

    Directory of Open Access Journals (Sweden)

    Xuemei Liao

    Full Text Available Angiogenesis is a key step for tumour growth and metastasis, and anti-angiogenesis has been proposed as an important strategy for cancer therapy. Tryptanthrin is a weakly basic alkaloid isolated from the dried roots of medicinal indigo plants and has been shown to possess anti-tumour activities on various cancer cell types. This study aims to investigate the in vitro and in vivo anti-angiogenic activities of tryptanthrin and to unravel its underlying molecular action mechanisms. Our results show that tryptanthrin inhibited the in vitro proliferation, migration, and tube formation of the human microvascular endothelial cells (HMEC-1 in a concentration-dependent manner and significantly suppressed angiogenesis in Matrigel plugs in mice. Mechanistic studies indicated that tryptanthrin reduced the expression of several pro-angiogenic factors (Ang-1, PDGFB and MMP2. Tryptanthrin was also found to suppress the VEGFR2-mediated ERK1/2 signalling pathway in HMEC-1 cells and molecular docking simulation indicated that tryptanthrin could bound to the ATP-binding site of VEGFR2. Collectively, the present study demonstrated that tryptanthrin exhibited both in vitro and in vivo anti-angiogenic activities by targeting the VEGFR2-mediated ERK1/2 signalling pathway and might have therapeutic potential for the treatment of angiogenesis-related diseases.

  8. Tryptanthrin inhibits angiogenesis by targeting the VEGFR2-mediated ERK1/2 signalling pathway.

    Science.gov (United States)

    Liao, Xuemei; Zhou, Xuelin; Mak, Nai-ki; Leung, Kwok-nam

    2013-01-01

    Angiogenesis is a key step for tumour growth and metastasis, and anti-angiogenesis has been proposed as an important strategy for cancer therapy. Tryptanthrin is a weakly basic alkaloid isolated from the dried roots of medicinal indigo plants and has been shown to possess anti-tumour activities on various cancer cell types. This study aims to investigate the in vitro and in vivo anti-angiogenic activities of tryptanthrin and to unravel its underlying molecular action mechanisms. Our results show that tryptanthrin inhibited the in vitro proliferation, migration, and tube formation of the human microvascular endothelial cells (HMEC-1) in a concentration-dependent manner and significantly suppressed angiogenesis in Matrigel plugs in mice. Mechanistic studies indicated that tryptanthrin reduced the expression of several pro-angiogenic factors (Ang-1, PDGFB and MMP2). Tryptanthrin was also found to suppress the VEGFR2-mediated ERK1/2 signalling pathway in HMEC-1 cells and molecular docking simulation indicated that tryptanthrin could bound to the ATP-binding site of VEGFR2. Collectively, the present study demonstrated that tryptanthrin exhibited both in vitro and in vivo anti-angiogenic activities by targeting the VEGFR2-mediated ERK1/2 signalling pathway and might have therapeutic potential for the treatment of angiogenesis-related diseases.

  9. VEGF, VEGFR-1 and VEGFR-2 immunoreactivity in the porcine arteries of vascular subovarian plexus (VSP during the estrous cycle.

    Directory of Open Access Journals (Sweden)

    A Andronowska

    2006-04-01

    Full Text Available Abstract: Vascular endothelial growth factor (VEGF is an important angiogenic factor in the female reproductive tract. It binds to cell surface through ligand-stimulatable tyrosine kinase receptors, the most important being VEGFR-1 (flt-1 and VEGFR-2 (flk-1. The broad ligament of the uterus is a dynamic organ consisting of specialized complexes of blood vessels connected functionally to the uterus, oviduct and ovary. Endothelial cells form an inner coating of the vessel walls and thus they stay under the influence of various modulators circulating in blood including ovarian steriods involved in developmental changes in the female reproductive system. The aim of the present study was to immunolocalize VEGF and its two receptors: VEGFR-1 and VEGFR-2 in the broad ligament of the uterus in the area of vascular subovarian plexus during different phases of the estrous cycle in pig and to determine the correlation between immunoreactivity of the investigated factors and phases of the estrous cycle. The study was performed on cryostat sections of vascular subovarian plexus stained immunohistochemically by ABC method. Specific polyclonal antibodies: anti-VEGF, anti-VEGFR-1 and anti-VEGFR-2 were used. Data were subjected to one-way analysis of variance. Our study revealed the presence of VEGF and its receptors in endothelial and smooth muscle cells of VSP arteries. All agents displayed phase-related differences in immunoreactivity suggesting the modulatory effect of VEGF, VEGFR-1 and VEGFR-2 on the arteries of the VSP in the porcine broad ligament of the uterus.

  10. Autocrine regulation of glioblastoma cell cycle progression, viability and radioresistance through the VEGF-VEGFR2 (KDR) interplay.

    Science.gov (United States)

    Knizetova, Petra; Ehrmann, Jiri; Hlobilkova, Alice; Vancova, Iveta; Kalita, Ondrej; Kolar, Zdenek; Bartek, Jiri

    2008-08-15

    Vascular endothelial growth factor (VEGF) plays a crucial role in angiogenesis and progression of malignant brain tumors. Given the significance of tumor microenvironment in general, and the established role of paracrine VEGF signaling in glioblastoma (GBM) biology in particular, we explored the potential autocrine control of human astrocytoma behavior by VEGF. Using a range of cell and molecular biology approaches to study a panel of astrocytoma (grade III and IV/GBM)-derived cell lines and a series of clinical specimens from low- and high-grade astrocytomas, we show that co-expression of VEGF and VEGF receptors (VEGFRs) occurs commonly in astrocytoma cells. We found VEGF secretion and VEGF-induced biological effects (modulation of cell cycle progression and enhanced viability of glioblastoma cells) to function in an autocrine manner. Morevover, we demonstrated that the autocrine VEGF signaling is mediated via VEGFR2 (KDR), and involves co-activation of the c-Raf/MAPK, PI3K/Akt and PLC/PKC pathways. Blockade of VEGFR2 by the selective inhibitor (SU1498) abrogated the VEGF-mediated enhancement of astrocytoma cell growth and viability under unperturbed culture conditions. In addition, such interference with VEGF-VEGFR2 signaling potentiated the ionizing radiation-induced tumor cell death. In clinical specimens, both VEGFRs and VEGF were co-expressed in astroglial tumor cells, and higher VEGF expression correlated with tumor progression, thereby supporting the relevance of functional VEGF-VEGFR signaling in vivo. Overall, our results are consistent with a potential autocrine role of the VEGF-VEGFR2 (KDR) interplay as a factor contributing to malignant astrocytoma growth and radioresistance, thereby supporting the candidacy of this signaling cascade as a therapeutic target, possibly in combination with radiotherapy.

  11. Expressions of Beta-Catenin, SUFU and VEGFR-2 Proteins in Medulloblastoma

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xiong; ZHANG Hong-mei; LI Yu; MI Can

    2007-01-01

    Objective: to investigate the expressions of beta-catenin, SUFU and VEGFR-2 proteins in medulloblastoma. Methods: Immunohistochemical staining with SP method was conducted to determine the expressions of beta-catenin, SUFU and VEGFR-2 in 33 cases of medulloblastoma and 10 normal cerebellar tissues. Results: the abnormal expression rates of beta-catenin and VEGFR-2 in medulloblastoma were significantly higher than that in normal tissue. While the positive expression of SUFU gene in medulloblastoma was significantly lower than that in 10 normal cerebellar tissues. A significant negative correlation was found between beta-catenin and SUFU proteins and a positive correlation between beta-catenin and VEGFR-2 was found in medulloblastoma. Conclusion: Beta-catenin, VEGFR-2 and SUFU have important effects on the pathogenesis and development of medulloblastoma.

  12. The miR-126-VEGFR2 axis controls the innate response to pathogen-associated nucleic acids.

    Science.gov (United States)

    Agudo, Judith; Ruzo, Albert; Tung, Navpreet; Salmon, Hélène; Leboeuf, Marylène; Hashimoto, Daigo; Becker, Christian; Garrett-Sinha, Lee-Ann; Baccarini, Alessia; Merad, Miriam; Brown, Brian D

    2014-01-01

    miR-126 is a microRNA expressed predominately by endothelial cells and controls angiogenesis. We found miR-126 was required for the innate response to pathogen-associated nucleic acids and that miR-126-deficient mice had greater susceptibility to infection with pseudotyped HIV. Profiling of miRNA indicated that miR-126 had high and specific expression by plasmacytoid dendritic cells (pDCs). Moreover, miR-126 controlled the survival and function of pDCs and regulated the expression of genes encoding molecules involved in the innate response, including Tlr7, Tlr9 and Nfkb1, as well as Kdr, which encodes the growth factor receptor VEGFR2. Deletion of Kdr in DCs resulted in reduced production of type I interferon, which supports the proposal of a role for VEGFR2 in miR-126 regulation of pDCs. Our studies identify the miR-126-VEGFR2 axis as an important regulator of the innate response that operates through multiscale control of pDCs.

  13. VEGF/VEGFR2 Axis in Periodontal Disease Progression and Angiogenesis: Basic Approach for a New Therapeutic Strategy.

    Science.gov (United States)

    Vladau, Mircea; Cimpean, Anca Maria; Balica, Raluca Amalia; Jitariu, Andreea Adriana; Popovici, Ramona Amina; Raica, Marius

    2016-01-01

    Periodontal lesions are associated with activation of pathological angiogenesis and a high number of newly-formed blood vessels. Most angiogenic growth factors have been studied in the crevicular fluid or serum, but tissue correlations with vascular density or endothelial proliferation, are very rare, even inexistent. We assessed the VEGF/VEGFR2 axis expression in a multimodal fashion, in both epithelial and stromal compartments, with emphasis to endothelial proliferation and severity of periodontal lesions. Compared to normal gingiva, negative for VEGF/VEGFR2, periodontal lesions had a progressive increase for these markers from low to severe periodontal lesions. The transition from low to moderate periodontal lesions represents the milestone in disease progression and implies an active angiogenesis based on the highest angiogenic parameter variability observed for these lesions. Epithelial vascularization was firstly observed in moderate periodontal lesions and persists during severe periodontal disease. All the parameters used to quantify angiogenesis in periodontal lesions, were significantly increased in severe periodontal lesions dependent on VEGF expression in both the epithelial and stromal compartment. Our results support the use of anti-VEGF/VEGFR2-targeted therapy as adjuvant treatment for severe periodontal lesions. Copyright © 2016 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

  14. Shear Stress Induces Differentiation of Endothelial Lineage Cells to Protect Neonatal Brain from Hypoxic-Ischemic Injury through NRP1 and VEGFR2 Signaling

    Directory of Open Access Journals (Sweden)

    Chia-Wei Huang

    2015-01-01

    Full Text Available Neonatal hypoxic-ischemic (HI brain injuries disrupt the integrity of neurovascular structure and lead to lifelong neurological deficit. The devastating damage can be ameliorated by preserving the endothelial network, but the source for therapeutic cells is limited. We aim to evaluate the beneficial effect of mechanical shear stress in the differentiation of endothelial lineage cells (ELCs from adipose-derived stem cells (ASCs and the possible intracellular signals to protect HI injury using cell-based therapy in the neonatal rats. The ASCs expressed early endothelial markers after biochemical stimulation of endothelial growth medium. The ELCs with full endothelial characteristics were accomplished after a subsequential shear stress application for 24 hours. When comparing the therapeutic potential of ASCs and ELCs, the ELCs treatment significantly reduced the infarction area and preserved neurovascular architecture in HI injured brain. The transplanted ELCs can migrate and engraft into the brain tissue, especially in vessels, where they promoted the angiogenesis. The activation of Akt by neuropilin 1 (NRP1 and vascular endothelial growth factor receptor 2 (VEGFR2 was important for ELC migration and following in vivo therapeutic outcomes. Therefore, the current study demonstrated importance of mechanical factor in stem cell differentiation and showed promising protection of brain from HI injury using ELCs treatment.

  15. Pancreatic endoplasmic reticulum kinase activation promotes medulloblastoma cell migration and invasion through induction of vascular endothelial growth factor A.

    Directory of Open Access Journals (Sweden)

    Stephanie Jamison

    Full Text Available Evidence is accumulating that activation of the pancreatic endoplasmic reticulum kinase (PERK in response to endoplasmic reticulum (ER stress adapts tumor cells to the tumor microenvironment and enhances tumor angiogenesis by inducing vascular endothelial growth factor A (VEGF-A. Recent studies suggest that VEGF-A can act directly on certain tumor cell types in an autocrine manner, via binding to VEGF receptor 2 (VEGFR2, to promote tumor cell migration and invasion. Although several reports show that PERK activation increases VEGF-A expression in medulloblastoma, the most common solid malignancy of childhood, the role that either PERK or VEGF-A plays in medulloblastoma remains elusive. In this study, we mimicked the moderate enhancement of PERK activity observed in tumor patients using a genetic approach and a pharmacologic approach, and found that moderate activation of PERK signaling facilitated medulloblastoma cell migration and invasion and increased the production of VEGF-A. Moreover, using the VEGFR2 inhibitor SU5416 and the VEGF-A neutralizing antibody to block VEGF-A/VEGFR2 signaling, our results suggested that tumor cell-derived VEGF-A promoted medulloblastoma cell migration and invasion through VEGFR2 signaling, and that both VEGF-A and VEGFR2 were required for the promoting effects of PERK activation on medulloblastoma cell migration and invasion. Thus, these findings suggest that moderate PERK activation promotes medulloblastoma cell migration and invasion through enhancement of VEGF-A/VEGFR2 signaling.

  16. Autocrine VEGF-VEGFR2-Neuropilin-1 signaling promotes glioma stem-like cell viability and tumor growth

    DEFF Research Database (Denmark)

    Hamerlik, Petra; Lathia, Justin D; Rasmussen, Rikke;

    2012-01-01

    glioma stem-like cells (GSCs), whose viability, self-renewal, and tumorigenicity rely, at least in part, on signaling through the VEGF-VEGFR2-Neuropilin-1 (NRP1) axis. We find that the limited impact of bevacizumab-mediated VEGF blockage may reflect ongoing autocrine signaling through VEGF-VEGFR2-NRP1......, which is associated with VEGFR2-NRP1 recycling and a pool of active VEGFR2 within a cytosolic compartment of a subset of human GBM cells. Whereas bevacizumab failed to inhibit prosurvival effects of VEGFR2-mediated signaling, GSC viability under unperturbed or radiation-evoked stress conditions...

  17. Design, synthesis and biological evaluation of type-II VEGFR-2 inhibitors based on quinoxaline scaffold.

    Science.gov (United States)

    Shahin, Mai I; Abou El Ella, Dalal A; Ismail, Nasser S M; Abouzid, Khaled A M

    2014-10-01

    In an effort to develop ATP-competitive VEGFR-2 selective inhibitors, a series of new quinoxaline-based derivatives was designed and synthesized. The target compounds were biologically evaluated for their inhibitory activity against VEGFR-2. The design of the target compounds was accomplished after a profound study of the structure activity relationship (SAR) of type-II VEGFR-2 inhibitors. Among the synthesized compounds, 1-(2-((4-methoxyphenyl)amino)-3-oxo-3,4 dihydroquinoxalin-6-yl)-3-phenylurea (VIIa) displayed the highest inhibitory activity against VEGFR-2. Molecular modeling study involving molecular docking and field alignment was implemented to interpret the variable inhibitory activity of the newly synthesized compounds.

  18. VEGF receptor-2 Y951 signaling and a role for the adapter molecule TSAd in tumor angiogenesis.

    Science.gov (United States)

    Matsumoto, Taro; Bohman, Svante; Dixelius, Johan; Berge, Tone; Dimberg, Anna; Magnusson, Peetra; Wang, Ling; Wikner, Charlotte; Qi, Jian Hua; Wernstedt, Christer; Wu, Jiong; Bruheim, Skjalg; Mugishima, Hideo; Mukhopadhyay, Debrabata; Spurkland, Anne; Claesson-Welsh, Lena

    2005-07-06

    Vascular endothelial growth factor receptor-2 (VEGFR-2) activation by VEGF-A is essential in vasculogenesis and angiogenesis. We have generated a pan-phosphorylation site map of VEGFR-2 and identified one major tyrosine phosphorylation site in the kinase insert (Y951), in addition to two major sites in the C-terminal tail (Y1175 and Y1214). In developing vessels, phosphorylation of Y1175 and Y1214 was detected in all VEGFR-2-expressing endothelial cells, whereas phosphorylation of Y951 was identified in a subset of vessels. Phosphorylated Y951 bound the T-cell-specific adapter (TSAd), which was expressed in tumor vessels. Mutation of Y951 to F and introduction of phosphorylated Y951 peptide or TSAd siRNA into endothelial cells blocked VEGF-A-induced actin stress fibers and migration, but not mitogenesis. Tumor vascularization and growth was reduced in TSAd-deficient mice, indicating a critical role of Y951-TSAd signaling in pathological angiogenesis.

  19. Computational investigation of sphingosine kinase 1 (SphK1) and calcium dependent ERK1/2 activation downstream of VEGFR2 in endothelial cells

    Science.gov (United States)

    Bazzazi, Hojjat; Popel, Aleksander S.

    2017-01-01

    Vascular endothelial growth factor (VEGF) is a powerful regulator of neovascularization. VEGF binding to its cognate receptor, VEGFR2, activates a number of signaling pathways including ERK1/2. Activation of ERK1/2 is experimentally shown to involve sphingosine kinase 1 (SphK1) activation and its calcium-dependent translocation downstream of ERK1/2. Here we construct a rule-based computational model of signaling downstream of VEGFR2, by including SphK1 and calcium positive feedback mechanisms, and investigate their consequences on ERK1/2 activation. The model predicts the existence of VEGF threshold in ERK1/2 activation that can be continuously tuned by cellular concentrations of SphK1 and sphingosine 1 phosphate (S1P). The computer model also predicts powerful effects of perturbations in plasma and ER calcium pump rates and the current through the CRAC channels on ERK1/2 activation dynamics, highlighting the critical role of intracellular calcium in shaping the pERK1/2 signal. The model is then utilized to simulate anti-angiogenic therapeutic interventions targeting VEGFR2-ERK1/2 axis. Simulations indicate that monotherapies that exclusively target VEGFR2 phosphorylation, VEGF, or VEGFR2 are ineffective in shutting down signaling to ERK1/2. By simulating therapeutic strategies that target multiple nodes of the pathway such as Raf and SphK1, we conclude that combination therapy should be much more effective in blocking VEGF signaling to EKR1/2. The model has important implications for interventions that target signaling pathways in angiogenesis relevant to cancer, vascular diseases, and wound healing. PMID:28178265

  20. Angiogenic and Vasculogenic Factors in the Vitreous from Patients with Proliferative Diabetic Retinopathy

    Directory of Open Access Journals (Sweden)

    Ahmed M. Abu El-Asrar

    2013-01-01

    Full Text Available This study was conducted to determine levels of angiogenic and endothelial progenitor cell mobilizing (vasculogenic factors in vitreous fluid from proliferative diabetic retinopathy (PDR patients and correlate their levels with clinical disease activity. Vascular endothelial growth factor (VEGF, soluble vascular endothelial growth factor receptor-2 (sVEGFR-2, stem cell factor (SCF, soluble c-kit (s-kit, endothelial nitric oxide synthase (eNOS, and prostaglandin E2 (PGE2 levels were measured by ELISA in vitreous samples from 34 PDR and 15 nondiabetic patients. eNOS was not detected. VEGF, sVEGFR-2, SCF, and s-kit levels were significantly higher in PDR with active neovascularization compared with quiescent PDR and nondiabetic patients (; 0.007; 0.001; , resp.. In contrast, PGE2 levels were significantly higher in nondiabetic patients compared with PDR patients (. There were significant correlations between levels of sVEGFR-2 versus SCF (, , sVEGFR-2 versus s-kit (, , and SCF versus s-kit (, . Our findings suggest that upregulation of VEGF, sVEGFR-2, SCF, and s-kit supports the contributions of angiogenesis and vasculogenesis in pathogenesis of PDR.

  1. Tuftsin binds neuropilin-1 through a sequence similar to that encoded by exon 8 of vascular endothelial growth factor.

    Science.gov (United States)

    von Wronski, Mathew A; Raju, Natarajan; Pillai, Radhakrishna; Bogdan, Nancy J; Marinelli, Edmund R; Nanjappan, Palaniappa; Ramalingam, Kondareddiar; Arunachalam, Thangavel; Eaton, Steve; Linder, Karen E; Yan, Feng; Pochon, Sibylle; Tweedle, Michael F; Nunn, Adrian D

    2006-03-03

    Tuftsin, Thr-Lys-Pro-Arg (TKPR), is an immunostimulatory peptide with reported nervous system effects as well. We unexpectedly found that tuftsin and a higher affinity antagonist, TKPPR, bind selectively to neuropilin-1 and block vascular endothelial growth factor (VEGF) binding to that receptor. Dimeric and tetrameric forms of TKPPR had greatly increased affinity for neuropilin-1 based on competition binding experiments. On endothelial cells tetrameric TKPPR inhibited the VEGF(165)-induced autophosphorylation of vascular endothelial growth factor receptor-2 (VEGFR-2) even though it did not directly inhibit VEGF binding to VEGFR-2. Homology between exon 8 of VEGF and TKPPR suggests that the sequence coded for by exon 8 may stabilize VEGF binding to neuropilin-1 to facilitate signaling through VEGFR-2. Given the overlap between processes involving neuropilin-1 and tuftsin, we propose that at least some of the previously reported effects of tuftsin are mediated through neuropilin-1.

  2. Markers of angiogenesis and epidermal growth factor receptor signalling in patients with pancreatic and gastroesophageal junction cancer

    DEFF Research Database (Denmark)

    Rohrberg, Kristoffer Staal; Skov, Birgit Guldhammer; Lassen, Ulrik;

    2010-01-01

    The epidermal growth factor receptor (EGFR) and angiogenesis are well established targets in anti-cancer therapy. Several targeted anti-cancer therapies are in clinical trials in pancreatic and gastroesophageal (GEJ) cancer. However, many patients do not respond to these targeted therapies...... in pancreatic and GEJ cancer patients, and could be investigated further as predictive biomarkers in such patients treated with EGFR or angiogenesis targeted therapies....... and there is therefore an increasing need for biomarkers for selection of patients to these therapies. We investigated the expression of EGFR, vascular endothelial growth factor A (VEGF-A), and VEGF receptor 2 (VEGFR-2) in tumour tissue by immunohistochemistry, and soluble EGFR (sEGFR), soluble VEGFR-2 (sVEGFR-2), basic...

  3. Phase I pharmacologic and biologic study of ramucirumab (IMC-1121B), a fully human immunoglobulin G1 monoclonal antibody targeting the vascular endothelial growth factor receptor-2.

    Science.gov (United States)

    Spratlin, Jennifer L; Cohen, Roger B; Eadens, Matthew; Gore, Lia; Camidge, D Ross; Diab, Sami; Leong, Stephen; O'Bryant, Cindy; Chow, Laura Q M; Serkova, Natalie J; Meropol, Neal J; Lewis, Nancy L; Chiorean, E Gabriela; Fox, Floyd; Youssoufian, Hagop; Rowinsky, Eric K; Eckhardt, S Gail

    2010-02-10

    PURPOSE To evaluate the safety, maximum-tolerated dose (MTD), pharmacokinetics (PKs), pharmacodynamics, and preliminary anticancer activity of ramucirumab (IMC-1121B), a fully human immunoglobulin G(1) monoclonal antibody targeting the vascular endothelial growth factor receptor (VEGFR)-2. PATIENTS AND METHODS Patients with advanced solid malignancies were treated once weekly with escalating doses of ramucirumab. Blood was sampled for PK studies throughout treatment. The effects of ramucirumab on circulating vascular endothelial growth factor-A (VEGF-A), soluble VEGFR-1 and VEGFR-2, tumor perfusion, and vascularity using dynamic contrast-enhanced magnetic resonance imaging were assessed. Results Thirty-seven patients were treated with 2 to 16 mg/kg of ramucirumab. After one patient each developed dose-limiting hypertension and deep venous thrombosis at 16 mg/kg, the next lower dose (13 mg/kg) was considered the MTD. Nausea, vomiting, headache, fatigue, and proteinuria were also noted. Four (15%) of 27 patients with measurable disease had a partial response (PR), and 11 (30%) of 37 patients had either a PR or stable disease lasting at least 6 months. PKs were characterized by dose-dependent elimination and nonlinear exposure consistent with saturable clearance. Mean trough concentrations exceeded biologically relevant target levels throughout treatment at all dose levels. Serum VEGF-A increased 1.5 to 3.5 times above pretreatment values and remained in this range throughout treatment at all dose levels. Tumor perfusion and vascularity decreased in 69% of evaluable patients. CONCLUSION Objective antitumor activity and antiangiogenic effects were observed over a wide range of dose levels, suggesting that ramucirumab may have a favorable therapeutic index in treating malignancies amenable to VEGFR-2 inhibition.

  4. The Structural Basis for the Function of Two Anti-VEGF Receptor 2 Antibodies

    Energy Technology Data Exchange (ETDEWEB)

    M Franklin; E Navarro; Y Wang; S Patel; P Singh; Y Zhang; K Persaud; A Bari; H Griffith; et al.

    2011-12-31

    The anti-VEGF receptor 2 antibody IMC-1121B is a promising antiangiogenic drug being tested for treatment of breast and gastric cancer. We have determined the structure of the 1121B Fab fragment in complex with domain 3 of VEGFR2, as well as the structure of a different neutralizing anti-VEGFR2 antibody, 6.64, also in complex with VEGFR2 domain 3. The two Fab fragments bind at opposite ends of VEGFR2 domain 3; 1121B directly blocks VEGF binding, whereas 6.64 may prevent receptor dimerization by perturbing the domain 3:domain 4 interface. Mutagenesis reveals that residues essential for VEGF, 1121B, and 6.64 binding are nonoverlapping among the three contact patches.

  5. The Structural Basis for the Function of Two Anti-VEGF Receptor 2 Antibodies

    Energy Technology Data Exchange (ETDEWEB)

    Franklin, Matthew C.; Navarro, Elizabeth C.; Wang, Yujie; Patel, Sheetal; Singh, Pinki; Zhang, Yi; Persaud, Kris; Bari, Amtul; Griffith, Heather; Shen, Leyi; Balderes, Paul; Kussie, Paul (ImClone)

    2011-10-28

    The anti-VEGF receptor 2 antibody IMC-1121B is a promising antiangiogenic drug being tested for treatment of breast and gastric cancer. We have determined the structure of the 1121B Fab fragment in complex with domain 3 of VEGFR2, as well as the structure of a different neutralizing anti-VEGFR2 antibody, 6.64, also in complex with VEGFR2 domain 3. The two Fab fragments bind at opposite ends of VEGFR2 domain 3; 1121B directly blocks VEGF binding, whereas 6.64 may prevent receptor dimerization by perturbing the domain 3:domain 4 interface. Mutagenesis reveals that residues essential for VEGF, 1121B, and 6.64 binding are nonoverlapping among the three contact patches.

  6. A phase-I study of lapatinib in combination with foretinib, a c-MET, AXL and vascular endothelial growth factor receptor inhibitor, in human epidermal growth factor receptor 2 (HER-2)-positive metastatic breast cancer.

    Science.gov (United States)

    Chia, Stephen K; Ellard, Susan L; Mates, Mihaela; Welch, Stephen; Mihalcioiu, Catalin; Miller, Wilson H; Gelmon, Karen; Lohrisch, Caroline; Kumar, Vikaash; Taylor, Sara; Hagerman, Linda; Goodwin, Rachel; Wang, Tao; Sakashita, Shingo; Tsao, Ming S; Eisenhauer, Elizabeth; Bradbury, Penelope

    2017-05-02

    The mechanisms of resistance to anti-human epidermal growth factor receptor 2 (HER 2) therapies are unclear but may include the tyrosine-protein kinase Met (c-Met), vascular endothelial growth factor (VEGF) and AXL pathways. Foretinib is an inhibitor of c-Met, VEGF receptor 2 (VEGFR-2), platelet-derived growth factor receptor beta (PDGFRB), AXL, Fms-like tyrosine kinase 3 (FLT3), angiopoiten receptor (TIE-2), RET and RON kinases. This phase Ib study sought to establish the associated toxicities, pharmacokinetics (PK) and recommended phase II doses (RP2D) of foretinib and lapatinib in a cohort of HER-2-positive patients with metastatic breast cancer (MBC). Women with HER-2 positive MBC, Performance status (PS 0-2), and no limit on number of prior chemotherapies or lines of anti-HER-2 therapies were enrolled. A 3 + 3 dose escalation design was utilized. Four dose levels were intended with starting doses of foretinib 30 mg and lapatinib 750 mg orally once a day (OD) on a 4-weekly cycle. Assessment of c-MET status from the primary archival tissue was performed. We enrolled 19 patients, all evaluable for toxicity assessment and for response evaluation. Median age was 60 years (34-86 years), 95% were PS 0-1, 53% were estrogen receptor-positive and 95% had at least one prior anti-HER-2-based regimen. The fourth dose level was reached (foretinib 45 mg/lapatinib 1250 mg) with dose-limiting toxicities of grade-3 diarrhea and fatigue. There was only one grade-4 non-hematological toxicity across all dose levels. There were no PK interactions between the agents. A median of two cycles was delivered across the dose levels (range 1-20) with associated progression-free survival of 3.2 months (95% CI 1.61-4.34 months). By immunohistochemical assessment with a specified cutoff, none of the 17 samples tested were classified as positive for c-Met. The RP2D of the combined foretinib and lapatinib is 45 mg and 1000 mg PO OD, respectively. Limited activity was seen with this

  7. First-in-Human Ultrasound Molecular Imaging With a VEGFR2-Specific Ultrasound Molecular Contrast Agent (BR55) in Prostate Cancer: A Safety and Feasibility Pilot Study.

    Science.gov (United States)

    Smeenge, Martijn; Tranquart, François; Mannaerts, Christophe K; de Reijke, Theo M; van de Vijver, Marc J; Laguna, M Pilar; Pochon, Sibylle; de la Rosette, Jean J M C H; Wijkstra, Hessel

    2017-07-01

    BR55, a vascular endothelial growth factor receptor 2 (VEGFR2)-specific ultrasound molecular contrast agent (MCA), has shown promising results in multiple preclinical models regarding cancer imaging. In this first-in-human, phase 0, exploratory study, we investigated the feasibility and safety of the MCA for the detection of prostate cancer (PCa) in men using clinical standard technology. Imaging with the MCA was performed in 24 patients with biopsy-proven PCa scheduled for radical prostatectomy using a clinical ultrasound scanner at low acoustic power. Safety monitoring was done by physical examination, blood pressure and heart rate measurements, electrocardiogram, and blood sampling. As first-in-human study, MCA dosing and imaging protocol were necessarily fine-tuned along the enrollment to improve visualization. Imaging data were correlated with radical prostatectomy histopathology to analyze the detection rate of ultrasound molecular imaging with the MCA. Imaging with MCA doses of 0.03 and 0.05 mL/kg was adequate to obtain contrast enhancement images up to 30 minutes after administration. No serious adverse events or clinically meaningful changes in safety monitoring data were identified during or after administration. BR55 dosing and imaging were fine-tuned in the first 12 patients leading to 12 subsequent patients with an improved MCA dosing and imaging protocol. Twenty-three patients underwent radical prostatectomy. A total of 52 lesions were determined to be malignant by histopathology with 26 (50%) of them seen during BR55 imaging. In the 11 patients that were scanned with the improved protocol and underwent radical prostatectomy, a total of 28 malignant lesions were determined: 19 (68%) were seen during BR55 ultrasound molecular imaging, whereas 9 (32%) were not identified. Ultrasound molecular imaging with BR55 is feasible with clinical standard technology and demonstrated a good safety profile. Detectable levels of the MCA can be reached in patients

  8. Cytotoxicity of VEGF121/rGel on vascular endothelial cells resulting in inhibition of angiogenesis is mediated via VEGFR-2

    Directory of Open Access Journals (Sweden)

    Hittelman Walter N

    2011-08-01

    Full Text Available Abstract Background The fusion protein VEGF121/rGel composed of the growth factor VEGF121 and the plant toxin gelonin targets the tumor neovasculature and exerts impressive anti-vascular effects. We have previously shown that VEGF121/rGel is cytotoxic to endothelial cells overexpressing VEGFR-2 but not to endothelial cells overexpressing VEGFR-1. In this study, we examined the basis for the specific toxicity of this construct and assessed its intracellular effects in vitro and in vivo. Methods We investigated the binding, cytotoxicity and internalization profile of VEGF121/rGel on endothelial cells expressing VEGFR-1 or VEGFR-2, identified its effects on angiogenesis models in vitro and ex vivo, and explored its intracellular effects on a number of molecular pathways using microarray analysis. Results Incubation of PAE/VEGFR-2 and PAE/VEGFR-1 cells with 125I-VEGF121/rGel demonstrated binding specificity that was competed with unlabeled VEGF121/rGel but not with unlabeled gelonin. Assessment of the effect of VEGF121/rGel on blocking tube formation in vitro revealed a 100-fold difference in IC50 levels between PAE/VEGFR-2 (1 nM and PAE/VEGFR-1 (100 nM cells. VEGF121/rGel entered PAE/VEGFR-2 cells within one hour of treatment but was not detected in PAE/VEGFR-1 cells up to 24 hours after treatment. In vascularization studies using chicken chorioallantoic membranes, 1 nM VEGF121/rGel completely inhibited bFGF-stimulated neovascular growth. The cytotoxic effects of VEGF121/rGel were not apoptotic since treated cells were TUNEL-negative with no evidence of PARP cleavage or alteration in the protein levels of select apoptotic markers. Microarray analysis of VEGF121/rGel-treated HUVECs revealed the upregulation of a unique "fingerprint" profile of 22 genes that control cell adhesion, apoptosis, transcription regulation, chemotaxis, and inflammatory response. Conclusions Taken together, these data confirm the selectivity of VEGF121/rGel for VEGFR-2

  9. Widdrol, a sesquiterpene isolated from Juniperus chinensis, inhibits angiogenesis by targeting vascular endothelial growth factor receptor 2 signaling.

    Science.gov (United States)

    Jin, Soojung; Yun, Hee Jung; Jeong, Hyun Young; Oh, You Na; Park, Hyun-Jin; Yun, Seung-Geun; Kim, Byung Woo; Kwon, Hyun Ju

    2015-09-01

    Widdrol is an odorous compound derived from Juniperus chinensis that is widely used in traditional medicine to treat fever, inflammation and cancer. It was previously reported that widdrol has antitumor activity by apoptosis induction in cancer cells in vitro. However, its anti-angiogenic activity remains elusive. In the present study, we investigated the anti‑angiogenic activity of widdrol and the molecular mechanisms involved. Widdrol inhibited cell proliferation via G1 phase arrest induction in human umbilical vein endothelial cells (HUVECs) in a dose-dependent manner. Additionally, it was associated with a decreased expression of cyclin-dependent kinase 2 (CDK2) and an increased expression of p21, a CDK inhibitor. Widdrol significantly inhibited the cell migration and tube formation of HUVECs using an in vitro angiogenesis assay. The results showed that widdrol suppressed phosphorylation of vascular endothelial growth factor receptor 2 (VEGFR2) and its downstream proteins, such as AKT, focal adhesion kinase (FAK) and endothelial nitric oxide synthase (eNOS). Moreover, widdrol effectively reduced tumor growth and blood vessel formation in colon tumor xenograft mice. Collectively, these results suggested that widdrol may act as a potential anti-angiogenic agent by inhibiting vessel sprouting and growth, which may have implications for angioprevention.

  10. Expression of CYR61, CTGF, VEGF-C, VEGFR-2 mRNA in Bone Marrow of Leukemia Patients and Its Clinical Significance%白血病患者骨髓CYR61、CTGF、VEGF-C、VEGFR-2mRNA的表达及其临床意义

    Institute of Scientific and Technical Information of China (English)

    徐宁; 李静; 李喆; 李志芹; 韩海燕; 贺其图; 卢燕; 韩轩茂; 马宏杰; 张冬霞; 刘学文; 袁晓俊; 贾国荣

    2011-01-01

    leukemia, promote the development, metastasis and infiltration of leukemia; and these factors in different types of leukemia and extramedullary infiltration are different, which may become tumor markers of leukemia; and blocking VEGF-C and VEGFR-2 may block tumor growth and metastasis.%本研究检测白血病患者骨髓中CYR61、CTGF、VEGF-C、VEGFR-2 mRNA的表达水平,探讨白血病发生、发展、浸润、转移中CYR61、CTGF、VEGF-C、VEGFR-2蛋白的相互作用及其临床意义,寻找新的肿瘤标记物,为白血病的诊治提供新的思路.白血病74例,男38例,女36例,年龄6 - 77岁,中位年龄45岁.对照组12例,男7例,女5例.年龄16 -78岁,中位年龄46岁.采用半定量逆转录聚合酶链反应(RT-PCR)方法测定CYR61、CTGF、VEGF-C、VEGFR-2 mRNA的水平.结果表明,各组初发急性和慢性白血病患者骨髓中CYR61、CTGF、VEGF-C、VEGFR-2 mRNA的表达与对照组相比均显著升高(p<0.05).急性白血病缓解后CYR61和CTGF mRNA的表达高于对照组(p =0.039,0.025).CTGF mRNA的表达在B-ALL组表达最高,高于AML、CML、CLL、T-ALL组(p=0.002,0.034,0.002,0.010).AML组CYR61与CTGF、CYR61与VEGF-C、CTGF与VEGFR-2 mRNA的表达均呈正相关(r =0.452,0.466,0.464;p =0.045,0.038,0.039),CML组CYR61与VEGF-C mRNA的表达呈正相关(r=0.882,p=0.000).急性白血病伴有髓外浸润者VEGF-C和VEGFR-2 mRNA的表达高于不伴有髓外浸润者(p=0.028,0.047).AML组VEGF-C mRNA的表达与原始细胞数呈正相关(r =0.418,p=0.034).结论:CYR61、CTGF及VEGF-C、VEGFR-2在白血病发病中相互作用,促进白血病发展、转移及浸润;且这些因子在不同类型白血病及髓外浸润中的作用存在差异.它们可能成为检测白血病的肿瘤标记物;阻断上述因子有可能阻断肿瘤的生长和转移.

  11. Fibroblast growth factor receptor 2 plays an essential role in telencephalic progenitors.

    Science.gov (United States)

    Ever, Leah; Zhao, Rui-Jing; Eswarakumar, Veraragavan P; Gaiano, Nicholas

    2008-01-01

    We used loss-of-function analysis to determine the role of fibroblast growth factor receptor 2 (FGFR2) in telencephalic progenitors, and also to examine interactions between FGFR and Notch signaling. While the telencephalon of FGFR2 mutants appears grossly normal, mutant telencephalic progenitors exhibit altered proliferative behavior in vivo and in vitro. Based upon our prior finding that Notch1 activation increased neurosphere frequency in FGF2, we tested whether this effect is mediated by FGFR1 or FGFR2. We found that Notch1 activation increased neurosphere frequency in cells mutant for either FGFR1 or FGFR2, but had no effect on the reduced size of neurospheres mutant for those receptors. Additional analyses revealed biochemical changes in the adult neocortex mutant for the IIIc isoform of FGFR2, and essential roles for FGFR2 in nasopharynx, eyelid, and cornea development.

  12. Ynamide Click chemistry in development of triazole VEGFR2 TK modulators.

    Science.gov (United States)

    Vojtičková, Margaréta; Dobiaš, Juraj; Hanquet, Gilles; Addová, Gabriela; Cetin-Atalay, Rengul; Yildirim, Deniz Cansen; Boháč, Andrej

    2015-10-20

    Structure novelty, chemical stability and synthetic feasibility attracted us to design 1,2,3-triazole compounds as potential inhibitors of VEGFR2 tyrosine kinase. Novel triazoles T1-T7 were proposed by oxazole (AAZ from PDB: 1Y6A)/1,2,3-triazole isosteric replacement, molecular modelling and docking. In order to enable synthesis of T1-T7 we developed a methodology for preparation of ynamide 22. Compound 22 was used for all Click chemistry reactions leading to triazoles T1-T3 and T6-T7. Among the obtained products, T1, T3 and T7 specifically bind VEGFR2 TK and modulate its activity by concentration dependent manner. Moreover predicted binding poses of T1-T7 in VEGFR2 TK were similar to the one known for the oxazole inhibitor AAZ (PDB: 1Y6A). Unfortunately the VEGFR2 inhibition by triazoles e.g. T3 and T7 is lower than that determined for their oxazole bioisosters T3-ox and AAZ, resp. Different electronic properties of 1,2,3-triazole/oxazole heterocyclic rings were proposed to be the main reason for the diminished affinity of T1-T3, T6 and T7 to an oxazole AAZ inhibitor binding site in VEGFR2 TK (PDB: 1Y6A or 1Y6B). Moreover T1-T3 and T6 were screened on cytotoxic activity against two human hepatocellular carcinoma cell lines. Selective cytotoxic activity of T2 against aggressive Mahlavu cells has been discovered indicating possible affinity of T2 to Mahlavu constitutionally active PI3K/Akt pathway.

  13. Luteolin inhibits human prostate tumor growth by suppressing vascular endothelial growth factor receptor 2-mediated angiogenesis.

    Directory of Open Access Journals (Sweden)

    Poyil Pratheeshkumar

    Full Text Available Angiogenesis, the formation of new blood vessels from pre-existing vascular beds, is essential for tumor growth, invasion, and metastasis. Luteolin is a common dietary flavonoid found in fruits and vegetables. We studied the antiangiogenic activity of luteolin using in vitro, ex vivo, and in vivo models. In vitro studies using rat aortic ring assay showed that luteolin at non-toxic concentrations significantly inhibited microvessel sprouting and proliferation, migration, invasion and tube formation of endothelial cells, which are key events in the process of angiogenesis. Luteolin also inhibited ex vivo angiogenesis as revealed by chicken egg chorioallantoic membrane assay (CAM and matrigel plug assay. Gelatin zymographic analysis demonstrated the inhibitory effect of luteolin on the activation of matrix metalloproteinases MMP-2 and MMP-9. Western blot analysis showed that luteolin suppressed VEGF induced phosphorylation of VEGF receptor 2 and their downstream protein kinases AKT, ERK, mTOR, P70S6K, MMP-2, and MMP-9 in HUVECs. Proinflammatory cytokines such as IL-1β, IL-6, IL-8, and TNF-α level were significantly reduced by the treatment of luteolin in PC-3 cells. Luteolin (10 mg/kg/d significantly reduced the volume and the weight of solid tumors in prostate xenograft mouse model, indicating that luteolin inhibited tumorigenesis by targeting angiogenesis. CD31 and CD34 immunohistochemical staining further revealed that the microvessel density could be remarkably suppressed by luteolin. Moreover, luteolin reduced cell viability and induced apoptosis in prostate cancer cells, which were correlated with the downregulation of AKT, ERK, mTOR, P70S6K, MMP-2, and MMP-9 expressions. Taken together, our findings demonstrate that luteolin inhibits human prostate tumor growth by suppressing vascular endothelial growth factor receptor 2-mediated angiogenesis.

  14. VEGFR2 heterogeneity and response to anti-angiogenic low dose metronomic cyclophosphamide treatment

    Directory of Open Access Journals (Sweden)

    Skowronski Karolina

    2010-12-01

    Full Text Available Abstract Background Targeting tumor vasculature is a strategy with great promise in the treatment of many cancers. However, anti-angiogenic reagents that target VEGF/VEGFR2 signaling have met with variable results clinically. Among the possible reasons for this may be heterogeneous expression of the target protein. Methods Double immunofluorescent staining was performed on formalin-fixed paraffin embedded sections of treated and control SW480 (colorectal and WM239 (melanoma xenografts, and tissue microarrays of human colorectal carcinoma and melanoma. Xenografts were developed using RAG1-/- mice by injection with WM239 or SW480 cells and mice were treated with 20 mg/kg/day of cyclophosphamide in their drinking water for up to 18 days. Treated and control tissues were characterized by double immunofluorescence using the mural cell marker α-SMA and CD31, while the ratio of desmin/CD31 was also determined by western blot. Hypoxia in treated and control tissues were quantified using both western blotting for HIF-1α and immunohistochemistry of CA-IX. Results VEGFR2 is heterogeneously expressed in tumor vasculature in both malignant melanoma and colorectal carcinoma. We observed a significant decrease in microvascular density (MVD in response to low dose metronomic cyclophosphamide chemotherapy in both malignant melanoma (with higher proportion VEGFR2 positive blood vessels; 93% and colorectal carcinoma (with lower proportion VEGFR2 positive blood vessels; 60% xenografts. This reduction in MVD occurred in the absence of a significant anti-tumor effect. We also observed less hypoxia in treated melanoma xenografts, despite successful anti-angiogenic blockade, but no change in hypoxia of colorectal xenografts, suggesting that decreases in tumor hypoxia reflect a complex relationship with vascular density. Based on α-SMA staining and the ratio of desmin to CD31 expression as markers of tumor blood vessel functionality, we found evidence for increased

  15. Minimally invasive colon resection is associated with a transient increase in plasma sVEGFR1 levels and a decrease in sVEGFR2 levels during the early postoperative period.

    Science.gov (United States)

    Shantha Kumara, H M C; Cabot, J C; Hoffman, A; Luchtefeld, M; Kalady, M F; Hyman, N; Feingold, D; Baxter, R; Whelan, R Larry

    2009-04-01

    Plasma vascular endothelial growth factor (VEGF) levels are elevated for 2-4 weeks after minimally invasive colorectal resection (MICR). VEGF induces wound and tumor angiogenesis by binding to endothelial cell (EC)-bound VEGF-receptor 1 (VEGFR1) and VEGFR2. Soluble receptors (sVEGFR1, sVEGFR2) sequester VEGF in the blood and decrease VEGF's proangiogenic effect. The importance of the MICR-related VEGF changes depends on the effect of surgical procedures on sVEGFR1 and sVEGFR2; this study assessed levels of these proteins after MICR for benign indications. Blood samples were taken (n=39) preoperatively (preop) and on postoperative days (POD) 1 and 3; in most cases a fourth sample was drawn between POD 7 and 30. sVEGFR1 and sVEGFR2 levels were measured via enzyme-linked immunosorbent assay (ELISA), which detects free and VEGF bound soluble receptor. Late samples were bundled into POD 7-13 and POD 14-30 time points. Results are reported as mean and standard deviation. The data was assessed with paired-samples t-test. Preop, mean plasma sVEGFR2 level (9,203.7+/-1,934.3 pg/ml) was significantly higher than the sVEGFR1 value (132.5+/-126.2 pg/ml). sVEGFR2 levels were significantly lower on POD 1 (6,957.8+/-1,947.7 pg/ml,) and POD 3 (7,085.6+/-2,000.2 pg/ml), whereas sVEGFR1 levels were significantly higher on POD 1 (220.0+/-132.8 pg/ml) and POD 3 (182.7+/-102.1 pg/ml) versus preop results. No differences were found on POD 7-13 or 14-30. sVEGFR2 values decreased and sVEGFR1 levels increased early after MICR; due to its much higher baseline, the sVEGFR2 changes dominate. The net result is less VEGF bound to soluble receptor and more free plasma VEGF.

  16. A Simple Bioassay for the Evaluation of Vascular Endothelial Growth Factors.

    Science.gov (United States)

    Stacker, Steven A; Halford, Michael M; Roufail, Sally; Caesar, Carol; Achen, Marc G

    2016-03-15

    The analysis of receptor tyrosine kinases and their interacting ligands involved in vascular biology is often challenging due to the constitutive expression of families of related receptors, a broad range of related ligands and the difficulty of dealing with primary cultures of specialized endothelial cells. Here we describe a bioassay for the detection of ligands to the vascular endothelial growth factor receptor-2 (VEGFR-2), a key transducer of signals that promote angiogenesis and lymphangiogenesis. A cDNA encoding a fusion of the extracellular (ligand-binding) region of VEGFR-2 with the transmembrane and cytoplasmic regions of the erythropoietin receptor (EpoR) is expressed in the factor-dependent cell line Ba/F3. This cell line grows in the presence of interleukin-3 (IL-3) and withdrawal of this factor results in death of the cells within 24 hr. Expression of the VEGFR-2/EpoR receptor fusion provides an alternative mechanism to promote survival and potentially proliferation of stably transfected Ba/F3 cells in the presence of a ligand capable of binding and cross-linking the extracellular portion of the fusion protein (i.e., one that can cross-link the VEGFR-2 extracellular region). The assay can be performed in two ways: a semi-quantitative approach in which small volumes of ligand and cells permit a rapid result in 24 hr, and a quantitative approach involving surrogate markers of a viable cell number. The assay is relatively easy to perform, is highly responsive to known VEGFR-2 ligands and can accommodate extracellular inhibitors of VEGFR-2 signaling such as monoclonal antibodies to the receptor or ligands, and soluble ligand traps.

  17. Expression of thymidine kinase mediated by a novel non-viral delivery system under the control of vascular endothelial growth factor receptor 2 promoter selectively kills human umbilical vein endothelial cells

    Institute of Scientific and Technical Information of China (English)

    Ying Wang; Hui-Xiong Xu; Ming-De Lu; Qing Tang

    2008-01-01

    AIM: To investigate the killing efficiency of a recombinant plasmid containing a thymidine kinase (TK) domain insert driven by the vascular endothelial growth factor receptor 2 (VEGFR2) promoter (KDR) on vascular endothelial cells.METHODS: The KDR-TK fragment was extracted from pBluescript 11 KDR-TK plasmid by enzymatic digestion with XhoI and Sa/I. The enhanced green fluorescence protein (EGFP) carrier was extracted from pEGFP by the same procedure. The KDR-TK was inserted into the pEGFP carrier to construct pEGFP-KDR-TK. Using ultrasound irradiation and microbubble,pEGFP-KDR-TK was transferred into human umbilical vein endothelial cells (HUVECs). The transient infection rate was estimated by green fluorescent protein (GFP)expression. Transfected HUVECs, non-transfected HUVECs, and HepG2 cells were cultured in the presence of different concentrations of ganciclovir (GCV), and the killing efficacy of HSV-TK/GCV was analyzed by 3-[4,5-dimethylthiazol-2-yl]-2, 5-diphenyl tetrazolium bromide (MTr) assay.RESULTS: The recombinant pEGFP-KDR-TK was successfully constructed by inserting the KDR-TK fragment into the pEGFP carrier. Transfected HUVECs showed cytoplasmic green fluorescence, and the transient transfection rate was about 20.3%. Pools of G418-resistant cells exhibited a higher sensitivity to the prodrug/GCV compared to non-transfected HUVECs or non-transfected HepG2 cells, respectively.CONCLUSION: KDR promoter and the suicide gene/prodrug system mediated by diagnostic ultrasound combined with microbubble can significantly kill HUVECs.Such therapy may present a novel and attractive approach to target gene therapy on tumor vessels.

  18. Effects of acoustic radiation force on the binding efficiency of BR55, a VEGFR2-specific ultrasound contrast agent.

    Science.gov (United States)

    Frinking, Peter J A; Tardy, Isabelle; Théraulaz, Martine; Arditi, Marcel; Powers, Jeffry; Pochon, Sibylle; Tranquart, François

    2012-08-01

    This work describes an in vivo study analyzing the effect of acoustic radiation force (ARF) on the binding of BR55 VEGFR2-specific contrast-agent microbubbles in a model of prostatic adenocarcinoma in rat. A commercial ultrasound system was modified by implementing high duty-cycle 3.5-MHz center frequency ARF bursts in a scanning configuration. This enabled comparing the effects of ARF on binding in tumor and healthy tissue effectively in the same field of view. Bubble binding was established by measuring late-phase enhancement in amplitude modulation (AM) contrast-specific imaging mode (4 MHz, 150 kPa) 10 min after agent injection when the unbound bubbles were cleared from the circulation. Optimal experimental conditions, such as agent concentration (0.4 × 10(8)-1.6 × 10(8) bubbles/kg), acoustic pressure amplitude (26-51 kPa) and duty-cycle (20%-95%) of the ARF bursts, were evaluated in their ability to enhance binding in tumor without significantly increasing binding in healthy tissue. Using the optimal conditions (38 kPa peak-negative pressure, 95% duty cycle), ARF-assisted binding of BR55 improved significantly in tumor (by a factor of 7) at a lower agent dose compared with binding without ARF, and it had an insignificant effect on binding in healthy tissue. Thus, the high binding specificity of BR55 microbubbles for targeting VEGFR2 present at sites of active angiogenesis was confirmed by this study. Therefore, it is believed that based on the results obtained in this work, ultrasound molecular imaging using target-specific contrast-agent microbubbles should preferably be performed in combination with ARF. Copyright © 2012 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

  19. Lapatinib plus trastuzumab in pretreated human epidermal growth factor receptor 2-positive metastatic breast cancer

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    Miguel J Sotelo

    2014-01-01

    Full Text Available Background: Dual human epidermal growth factor receptor 2 (HER2 blockade has been preclinically and clinically assessed in HER2-overexpressing metastatic breast cancer (mBC with encouraging results. Patients and Methods: This is a descriptive retrospective study of trastuzumab plus lapatinib activity in patients with HER2-overexpressing mBC from two centers. The primary endpoints were to assess objective response rate (ORR and toxicity. The secondary endpoints were to assess progression-free survival (PFS and overall survival. Results: A total of 23 HER2-positive mBC patients previously treated with trastuzumab received a trastuzumab plus lapatinib based therapy. Chemotherapy (CT was added to the dual HER2 blockade treatment in 13 patients (56%, whereas hormonotherapy (HT was added in 8 patients (35% and 2 patients (9% received lapatinib plus trastuzumab without any other agent. ORR was 22% (5/23 and 39% (9/23 of patients had stable disease. PFS in the overall population was 4 months. PFS in patients with CT was 5 months, whereas PFS in patients with HT was 2 months. Grade ≥ 3 adverse events were diarrhea (26% and hand-and-foot syndrome (9%. Conclusions: These findings suggest that dual HER2 blockade in combination with CT is feasible in pretreated HER2-positive mBC patients.

  20. Pertuzumab in human epidermal growth-factor receptor 2-positive breast cancer: clinical and economic considerations

    Directory of Open Access Journals (Sweden)

    Lamond NW

    2014-05-01

    Full Text Available Nathan WD Lamond, Tallal YounisDepartment of Medicine, Dalhousie University at the Queen Elizabeth II Health Sciences Centre, Halifax, NS, CanadaAbstract: In the absence of specific therapy, the 15%–20% of breast cancers demonstrating human epidermal growth-factor receptor 2 (HER2 protein overexpression and/or gene amplification are characterized by a more aggressive phenotype and poorer prognosis compared to their HER2-negative counterparts. Trastuzumab (Herceptin, the first anti-HER2-targeted therapy, has been associated with improved survival outcomes in HER2-positive breast cancer. However, many patients with early stage disease continue to relapse, and metastatic disease remains incurable. In order to further improve these outcomes, several novel HER2-targeted agents have recently been developed. Pertuzumab (Perjeta, a monoclonal antibody against the HER2 dimerization domain, has also been associated with improved patient outcomes in clinical trials, and has recently been approved in combination with chemotherapy and trastuzumab for neoadjuvant therapy of early stage, HER2-positive breast cancer and first-line treatment of metastatic disease. This review briefly summarizes pertuzumab's clinical development as well as the published evidence supporting its use, and highlights some of the currently unanswered questions that will influence pertuzumab’s incorporation into clinical practice.Keywords: HER2/neu, clinical trials, drug development, novel therapies, targeted anticancer therapy

  1. Human epidermal growth factor receptor 2 expression in mixed gastric carcinoma.

    Science.gov (United States)

    Wang, Yang-Kun; Chen, Zhong; Yun, Tian; Li, Cong-Yang; Jiang, Bo; Lv, Xue-Xia; Chu, Guang-Hui; Wang, Su-Nan; Yan, Hui; Shi, Lei-Feng

    2015-04-21

    To investigate human epidermal growth factor receptor 2 (HER2) amplification and protein expression in mixed gastric carcinoma. Fluorescence in situ hybridization and immunohistochemistry were used to detect HER2 amplification and protein expression in 277 cases of mixed gastric carcinoma. Protein staining intensity was rate as 1+, 2+, or 3+. Of the 277 cases, 114 (41.2%) expressed HER2 protein. HER2 3+ staining was observed in 28/277 (10.1%) cases, 2+ in 37/277 (13.4%) cases, and 1+ in 49/277 (17.7%) cases. A HER2 amplification rate of 17% was detected, of which 25/28 (89.3%) were observed in the HER2 3+ staining group, 17/37 (45.9%) in 2+, and 5/49 (10.2%) in 1+. Of the 47 patients with HER2 amplification who received chemotherapy plus trastuzumab, 22 demonstrated median progression-free and overall survivals of 9.1 mo and 16.7 mo, respectively, which were significantly better than those achieved with chemotherapy alone (5.6 mo and 12.1 mo, respectively) in 19 previously treated patients (Ps gastric carcinoma displays high heterogeneity. Relatively quantitative parameters are needed for assessing the level of HER2 amplification and protein expression.

  2. Differential gene expression profiling of human epidermal growth factor receptor 2-overexpressing mammary tumor

    Institute of Scientific and Technical Information of China (English)

    Yan Wang; Haining Peng; Yingli Zhong; Daiqiang Li; Mi Tang; Xiaofeng Ding; Jian Zhang

    2008-01-01

    Human epidermal growth factor receptor 2 (HER2) is highly expressed in approximately 30% of breast cancer patients,and substantial evidence supports the relationship between HER2 overexpression and poor overall survival. However,the biological function of HER2 signaltransduction pathways is not entirely clear. To investigate gene activation within the pathways, we screened differentially expressed genes in HER2-positive mouse mammary tumor using two-directional suppression subtractive hybridization combined with reverse dot-blotting analysis. Forty genes and expressed sequence tags related to transduction, cell proliferation/growth/apoptosis and secreted/extracellular matrix proteins were differentially expressed in HER2-positive mammary tumor tissue. Among these, 19 were already reported to be differentially expressed in mammary tumor, 11 were first identified to be differentially expressed in mammary tumor in this study but were already reported in other tumors, and 10 correlated with other cancers. These genes can facilitate the understanding of the role of HER2 signaling in breast cancer.

  3. Brain metastasis in human epidermal growth factor receptor 2-positive breast cancer: from biology to treatment

    Energy Technology Data Exchange (ETDEWEB)

    Koo, Tae Ryool [Dept. of Radiation Oncology, Hallym University Chuncheon Sacred Heart Hospital, Chuncheon (Korea, Republic of); Kim, In Ah [Dept. of Radiation Oncology, Seoul National University Bundang Hospital, Seongnam (Korea, Republic of)

    2016-03-15

    Overexpression of human epidermal growth factor receptor 2 (HER2) is found in about 20% of breast cancer patients. With treatment using trastuzumab, an anti-HER2 monoclonal antibody, systemic control is improved. Nonetheless, the incidence of brain metastasis does not be improved, rather seems to be increased in HER2-positive breast cancer. The mainstay treatment for brain metastases is radiotherapy. According to the number of metastatic lesions and performance status of patients, radiosurgery or whole brain radiotherapy can be performed. The concurrent use of a radiosensitizer further improves intracranial control. Due to its large molecular weight, trastuzumab has a limited ability to cross the blood-brain barrier. However, small tyrosine kinase inhibitors such as lapatinib, has been noted to be a promising agent that can be used as a radiosensitizer to affect HER2-positive breast cancer. This review will outline general management of brain metastases and will focus on preclinical findings regarding the radiosensitizing effect of small molecule HER2 targeting agents.

  4. The innate immune response in fetal lung mesenchymal cells targets VEGFR2 expression and activity.

    Science.gov (United States)

    Medal, Rachel M; Im, Amanda M; Yamamoto, Yasutoshi; Lakhdari, Omar; Blackwell, Timothy S; Hoffman, Hal M; Sahoo, Debashis; Prince, Lawrence S

    2017-06-01

    In preterm infants, soluble inflammatory mediators target lung mesenchymal cells, disrupting airway and alveolar morphogenesis. However, how mesenchymal cells respond directly to microbial stimuli remains poorly characterized. Our objective was to measure the genome-wide innate immune response in fetal lung mesenchymal cells exposed to the bacterial endotoxin lipopolysaccharide (LPS). With the use of Affymetrix MoGene 1.0st arrays, we showed that LPS induced expression of unique innate immune transcripts heavily weighted toward CC and CXC family chemokines. The transcriptional response was different between cells from E11, E15, and E18 mouse lungs. In all cells tested, LPS inhibited expression of a small core group of genes including the VEGF receptor Vegfr2 Although best characterized in vascular endothelial populations, we demonstrated here that fetal mouse lung mesenchymal cells express Vegfr2 and respond to VEGF-A stimulation. In mesenchymal cells, VEGF-A increased cell migration, activated the ERK/AKT pathway, and promoted FOXO3A nuclear exclusion. With the use of an experimental coculture model of epithelial-mesenchymal interactions, we also showed that VEGFR2 inhibition prevented formation of three-dimensional structures. Both LPS and tyrosine kinase inhibition reduced three-dimensional structure formation. Our data suggest a novel mechanism for inflammation-mediated defects in lung development involving reduced VEGF signaling in lung mesenchyme. Copyright © 2017 the American Physiological Society.

  5. Platycodin D inhibits tumor growth by antiangiogenic activity via blocking VEGFR2-mediated signaling pathway

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    Luan, Xin; Gao, Yun-Ge; Guan, Ying-Yun; Xu, Jian-Rong; Lu, Qin [Department of Pharmacology, Institute of Medical Sciences, Shanghai Jiao Tong University School of Medicine (SJTU-SM), Shanghai 200025 (China); Zhao, Mei [Department of Pharmacy, Shanghai Institute of Health Sciences and Health School Attached to SJTU-SM, 279 Zhouzhu Road, Shanghai 201318 (China); Liu, Ya-Rong; Liu, Hai-Jun [Department of Pharmacology, Institute of Medical Sciences, Shanghai Jiao Tong University School of Medicine (SJTU-SM), Shanghai 200025 (China); Fang, Chao, E-mail: fangchao100@hotmail.com [Department of Pharmacology, Institute of Medical Sciences, Shanghai Jiao Tong University School of Medicine (SJTU-SM), Shanghai 200025 (China); Chen, Hong-Zhuan, E-mail: hongzhuan_chen@hotmail.com [Department of Pharmacology, Institute of Medical Sciences, Shanghai Jiao Tong University School of Medicine (SJTU-SM), Shanghai 200025 (China)

    2014-11-15

    Platycodin D (PD) is an active component mainly isolated from the root of Platycodon grandiflorum. Recent studies proved that PD exhibited inhibitory effect on proliferation, migration, invasion and xenograft growth of diverse cancer cell lines. However, whether PD is suppressive for angiogenesis, an important hallmark in cancer development, remains unknown. Here, we found that PD could dose-dependently inhibit human umbilical vein endothelial cell (HUVEC) proliferation, motility, migration and tube formation. PD also significantly inhibited angiogenesis in the chick embryo chorioallantoic membrane (CAM). Moreover, the antiangiogenic activity of PD contributed to its in vivo anticancer potency shown in the decreased microvessel density and delayed growth of HCT-15 xenograft in mice with no overt toxicity. Western blot analysis indicated that PD inhibited the phosphorylation of VEGFR2 and its downstream protein kinase including PLCγ1, JAK2, FAK, Src, and Akt in endothelial cells. Molecular docking simulation showed that PD formed hydrogen bonds and hydrophobic interactions within the ATP binding pocket of VEGFR2 kinase domain. The present study firstly revealed the high antiangiogenic activity and the underlying molecular basis of PD, suggesting that PD may be a potential antiangiogenic agent for angiogenesis-related diseases. - Highlights: • Platycodin D inhibits HUVEC proliferation, motility, migration and tube formation. • Platycodin D inhibits the angiogenesis in chick embryo chorioallantoic membrane. • Platycodin D suppresses the angiogenesis and growth of HCT-15 xenograft in mice. • Platycodin D inhibits the phosphorylation of VEGFR2 and downstream kinases in HUVEC.

  6. 人参、三七组方对HUVEC VEGFR-2蛋白表达的影响

    Institute of Scientific and Technical Information of China (English)

    唐东昕; 田伟

    2011-01-01

    目的 探讨人参、三七组方对HUVEC VEGFR-2表达的影响.方法 采用免疫组织化学的方法,观察人参、三七组方干预后,HUVEC VEGFR-2的表达.结果 人参、三七组方大剂量组促进了HUVEC VEGFR-2的表达,其作用和bFGF 相当,和空白组相比有明显增加,且组间差异显著.结论 人参、三七组方可能通过促进VEGFR-2的表达而促进HUVEC的增殖.

  7. Human epidermal growth factor receptor 2/neu protein expression in meningiomas: An immunohistochemical study

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    Ramesh Babu Telugu

    2016-01-01

    Full Text Available Background: Meningiomas are common slow-growing primary central nervous system tumors that arise from the meningothelial cells of the arachnoid and spinal cord. Human epidermal growth factor receptor 2 (HER2 or HER2/neu (also known as c-erbB2 is a 185-kD transmembrane glycoprotein with tyrosine kinase activity expressed in meningiomas and various other tumors. It can be used in targeted therapy for HER2/neu positive meningiomas. Aim: To correlate the expression of HER2/neu protein in meningiomas with gender, location, histological subtypes, and grade. Materials and Methods: It was 3½ years prospective (March 2010–October 2011 and retrospective (May 2008–February 2010 study of histopathologically diagnosed intracranial and intraspinal meningiomas. Clinical details of all the cases were noted from the computerized hospital information system. Immunohistochemistry for HER2/neu protein was performed along with scoring. Statistical analysis was done using Chi-square test to look for any association of HER2/neu with gender, location, grade, and various histological subtypes of meningiomas at 5% level of significance. Results: A total of 100 cases of meningiomas were found during the study period. Of which, 80 were Grade I, 18 were Grade II, and 2 were Grade III meningiomas as per the World Health Organization 2007 criteria. The female-male ratio was 1.9:1 and the mean age was 47.8 years. HER2/neu protein was expressed in 75% of Grade I and 72.2% of Grade II and none of Grade III meningiomas. About 72.7% brain invasive meningiomas showed HER2/neu immunopositivity. Conclusion: HER2/neu protein was expressed in 73% of meningiomas. Statistically significant difference of HER2/neu expression was not seen between females and males of Grade I and Grade II/III meningiomas, intracranial and spinal tumors, Grade I and Grade II/III cases, and various histological subtypes of meningiomas.

  8. Expression of Human Epidermal Growth Factor Receptor-2 in Resected Rectal Cancer

    Science.gov (United States)

    Meng, Xiangjiao; Huang, Zhaoqin; Di, Jian; Mu, Dianbin; Wang, Yawei; Zhao, Xianguang; Zhao, Hanxi; Zhu, Wanqi; Li, Xiaolin; Kong, Lingling; Xing, Ligang

    2015-01-01

    Abstract The addition of trastuzumab to chemotherapy was demonstrated to be beneficial for advanced human epidermal growth factor receptor-2 (HER-2) positive gastric cancer. However, the HER-2 status of rectal cancer remains uncertain. This study aimed to determine the HER-2 expression in a large multicenter cohort of rectal cancer patients. The clinical and pathological features of 717 patients were retrospectively reviewed. All the patients were diagnosed with primary rectal adenocarcinoma without distant metastasis and took surgery directly without any preoperative anticancer treatment. HER-2 status was assessed on resected samples. A total of 99 cases with IHC3+ and 16 cases with IHC 2+ plus gene amplification were determined as HER-2 positive. 22.6% of HER-2 positive patients had local recurrence, whereas 16.9% of HER-2 negative patients did (P = 0.146). HER-2 positive tumors were more likely to have distant metastasis (P = 0.007). Univariate analysis revealed that pathological tumor stage, pathological node stage, positive margin, and lymphovascular invasion were significantly correlated with 5-year disease-free survival (DFS) and 5-year overall survival (OS). The patients with >10 dissected lymph nodes showed significantly longer OS (P = 0.045) but not DFS (P = 0.054). HER-2 negative patients had significantly better 5-year DFS (P < 0.001) and 5-year OS (P = 0.013) than those of the HER-2 positive patients. In the subgroup analysis for the early rectal cancer and locally advanced rectal cancer, HER-2 was also a poor predictor for survival. Multivariate analysis revealed that HER-2 was an independent prognostic factor for 5-year DFS (hazard ratio [HR] = 1.919, 95% confidence interval [CI] 1.415–2.605, P < 0.001) and for 5-year OS (HR = 1.549, 95% CI 1.097–2.186, P = 0.013). When the treatment was included in the analysis for locally advanced patients, HER-2 was a prognostic factor for 5-year DFS (P = 0.001) but not for

  9. 消痰散结方对胃癌微血管密度及VEGF-A/VEGFR-2的影响%Impacts of Xiaotan Sanjie Formula on Microvessel Density and VEGF -A/VEGFR-2 in Gastric Cancer

    Institute of Scientific and Technical Information of China (English)

    唐继贵; 魏品康; 张映城

    2015-01-01

    目的:研究消痰散结方对胃癌MVD及VEGF-A/VEGFR-2表达的影响。方法对20例自愿进行单纯中药抗肿瘤治疗的胃癌患者,留取消痰散结方进行干预前及干预6个月后的胃癌(癌组织、癌旁近端、远端)标本。采用免疫组化SP法检测CD34标记微血管密度MVD,Western Blot、RT-PCR检测VEGF-A/VEGFR-2的表达。结果消痰散结方对胃癌组、癌旁近端组、远端组微血管密度MVD和VEGF-A/VEGFR-2有不同程度的下调作用。胃癌组消痰散结方治疗后微血管密度和VEGF-A/VEGFR-2下降幅度最大( P0.05)。结论消痰散结方治疗胃癌的部分作用机制可能与其抑制VEGF-A/VEGFR-2信号通路降低微血管密度有关。%Objective To study the impacts of xiaotan sanjie formula on microvessel density( MVD) in VEGF-A/VEGFR-2 expression in gastric cancer. Methods The samples of gastric cancer( cancer tis-sue,proximal tissue,distal tissue)were collected before and 6 months after intervention with xiaotan sanjie formula in 20 volunteers treated with simple Chinese medicine for anti-tumor. IHC SP method was used to detect CD34 labeled MVD,western blot and RT-PCR methods were applied to detect VEGF-A/VEGFR-2 expression. Results Xiaotan sanjie formula down-regulates MVD and VEGF-A/VEGFR-2 in the gas-tric cancer group,proximal end group and distal end group to different degrees. In the gastric cancer group, after the treatment with xiaotan sanjie formula,MVD and VEGF-A/VEGFR-2 were reduced to the largest extent in the gastric cancer group(P0. 05),without statistical significance. Conclusion The mechanism on a part of effects of xiaotan sanjie formula on gastric cancer is possibly related with inhibiting VEGF-A/VEGFR-2 signal path and reducing MVD.

  10. Penduliflaworosin, a Diterpenoid from Croton crassifolius, Exerts Anti-Angiogenic Effect via VEGF Receptor-2 Signaling Pathway

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    Yeyin Liang

    2017-01-01

    Full Text Available Anti-angiogenesis targeting vascular endothelial growth factor receptor-2 (VEGFR-2 has been considered as an important strategy for cancer therapy. Penduliflaworosin is a diterpenoid isolated from the plant Croton crassifolius. Our previous study showed that this diterpenoid possesses strong anti-angiogenic activity by inhibiting vessel formation in zebrafish. This study was conducted to further investigate the anti-angiogenic activity and mechanism of penduliflaworosin. Results revealed that penduliflaworosin significantly inhibited VEGF-induced angiogenesis processes including proliferation, invasion, migration, and tube formation of human umbilical vein endothelial cells (HUVECs. Moreover, it notably inhibited VEGF-induced sprout formation of aortic rings and blocked VEGF-induced vessel formation in mice. Western blotting studies showed that penduliflaworosin inhibited phosphorylation of the VEGF receptor-2 and its downstream signaling mediators in HUVECs, suggesting that the anti-angiogenic activity was due to an interference with the VEGF/VEGF receptor-2 pathway. In addition, molecular docking simulation indicated that penduliflaworosin could form hydrogen bonds within the ATP-binding region of the VEGF receptor-2 kinase unit. Finally, cytotoxicity assay showed that penduliflaworosin possessed little toxicity toward both cancer and normal cells. Taken together, our findings demonstrate that penduliflaworosin exerts its anti-angiogenic effect via the VEGF receptor-2 signaling pathway. The anti-angiogenic property and low cytotoxicity of penduliflaworosin suggest that it may be useful in cancer treatments.

  11. Meta-analysis of individual patient safety data from six randomized, placebo-controlled trials with the antiangiogenic VEGFR2-binding monoclonal antibody ramucirumab.

    Science.gov (United States)

    Arnold, D; Fuchs, C; Tabernero, J; Ohtsu, A; Zhu, A X; Garon, E B; Mackey, J R; Paz-Ares, L; Baron, A D; Okusaka, T; Yoshino, T; Yoon, H H; Das, M; Ferry, D; Zhang, Y; Lin, Y; Binder, P; Sashegyi, A; Chau, I

    2017-09-07

    Ramucirumab, the human IgG1 monoclonal antibody receptor antagonist of vascular endothelial growth factor receptor 2 (VEGFR-2), has been approved for treating gastric/gastroesophageal junction, non-small cell lung, and metastatic colorectal cancers. With the completion of 6 global, randomized, double-blind, placebo-controlled, phase 3 trials across multiple tumor types, an opportunity now exists to further establish the safety parameters of ramucirumab across a large patient population. An individual patient meta-analysis across the 6 completed phase 3 trials was conducted and the relative risk (RR) and associated 95% confidence intervals (CI) were derived using fixed-effects or mixed-effects models for all-grade and high-grade adverse events (AEs) possibly related to VEGF pathway inhibition. The number needed to harm (NNH) was also calculable, due to the placebo-controlled nature of all 6 registration standard trials. A total of 4996 treated patients (N = 2748 in the ramucirumab arm, and N = 2248 in the control, placebo arm) were included in this meta-analysis. Arterial thromboembolic events (ATE, all-grade, RR: 0.8, 95% CI 0.5-1.3; high-grade [Grade ≥3], RR: 0.9, 95% CI 0.5-1.7), venous thromboembolic events (VTE, all-grade, RR: 0.7, 95% CI 0.5-1.1; high-grade, RR: 0.7, 95% CI 0.4-1.2), high-grade bleeding (RR: 1.1, 95% CI 0.8-1.5), and high-grade gastrointestinal (GI) bleeding (RR: 1.1, 95% CI 0.7-1.7) did not demonstrate a definite increased risk with ramucirumab. A higher percentage of hypertension, proteinuria, low-grade (Grade 1-2) bleeding, GI perforation, infusion-related reaction and wound-healing complications were observed in the ramucirumab arms compared to control. Ramucirumab may be distinct among antiangiogenic agents in terms of ATE, VTE, high-grade bleeding, or high-grade GI bleeding by showing no clear evidence for an increased risk of these AEs in this meta-analysis of a large and diverse patient population. Ramucirumab is consistent with

  12. Expression of T-Lymphocyte Markers in Human Epidermal Growth Factor Receptor 2-Positive Breast Cancer

    Science.gov (United States)

    Lee, Changro; Kim, Joo Heung; Lim, Sung Mook; Park, Hyung Seok; Kim, Seung Il; Park, Byeong-Woo

    2016-01-01

    Purpose The present study aimed to examine the clinical implications of CD4, CD8, and FOXP3 expression on the prognosis of human epidermal growth factor receptor 2 (HER2)-positive breast cancer using a web-based database, and to compare the immunohistochemical expression of T-lymphocyte markers using primary and metastatic HER2-positive tumor tissues before and after HER2-targeted therapy. Methods Using the cBioPortal for Cancer Genomics and Kaplan-Meier plotter, the mRNA expression, association between T-lymphocyte markers, and survival in HER2-positive cancers were investigated according to various cutoff levels. Immunohistochemistry analysis was performed using paired primary and metastatic tissues of 29 HER2-positive tumors treated with systemic chemotherapy and HER2-directed therapy. Results HER2 mRNA was mutually exclusive of T-lymphocyte markers, and a significant correlation between T-cell markers was observed in the cBioPortal for Cancer Genomics. According to analysis of the Kaplan-Meier plotter, the impact of T-lymphocyte marker expression on survival was statistically insignificant in clinical HER2-positive tumors, irrespective of the cutoff levels. However, in the intrinsic HER2-positive subtype, the individual analyses of T-cell markers except for FOXP3 and combined analysis showed significantly favorable survival irrespective of cutoff points. Although the small clinical sample size made it difficult to show the statistical relevance of immunohistochemistry findings, good responses to neoadjuvant treatments might be associated with positive expression of combined T-lymphocyte markers, and approximately half of the samples showed discordance of combined markers between baseline and resistant tumors. Conclusion T-lymphocyte markers could be favorable prognostic factors in HER2-positive breast cancers; however, a consensus on patient section criteria, detection methods, and cutoff value could not be reached. The resistance to HER2-directed therapy might

  13. Human epithelial growth factor receptor 2[Ile655Val] polymorphism and risk of breast fibroadenoma.

    Science.gov (United States)

    Zubor, Pavol; Kajo, Karol; Stanclova, Andrea; Szunyogh, Norbert; Galo, Silvester; Dussan, Carlos A; Minarik, Gabriel; Visnovsky, Jozef; Danko, Jan

    2008-02-01

    Studies on the association between the Ile to Val polymorphism at codon 655 of the human epithelial growth factor receptor 2 (HER-2) gene and susceptibility to breast cancer have been reported for almost all ethnic populations, with both positive or negative conclusions. No study, however, has yet been focused on the possible association between this gene and its predisposition to benign breast lesions, especially on risk for fibroadenoma. We aimed to study the association of the single nucleotide polymorphism V655 HER-2 gene polymorphism with histologically verified breast fibroadenoma risk. We conducted a molecular epidemiological case-control study of 70 breast fibroadenoma cases without cellular atypia and 172 healthy female controls. We found that the Val variant allele and genotype frequency of this polymorphism is higher in cases with fibroadenoma; however, this difference was not significant (allele Val 655: 27.86 and 22.67% in fibroadenoma and controls, respectively; genotype Ile/Val: 35.71 and 38.37% and Val/Val: 10.0 and 3.49% in fibroadenoma and controls, respectively). Applying logistic regression analysis, we found an increased risk of fibroadenoma formation in carriers of the Val allele (odds ratio = 1.17; 95% confidence interval = 0.67-2.05), in which the highest risk was associated with homozygous genotype (odds ratio = 3.07; 95% confidence interval = 0.97-9.72), but this risk was not significant. Stratification by age (cut-off 45 years) revealed the highest risk of fibroadenoma among young women homozygous for the Val allele (odds ratio = 3.30). The risk, however, was slightly increased (odds ratio = 1.24) among older carriers of the aberrant allele in their genotype as well, but it was not significant. In spite of insignificant differences, our results indicate that HER-2 Ile655Val polymorphism, especially in a homozygous form might play some role in the etiology of breast fibroadenoma formation. The significance of this susceptibility, however

  14. VEGFR-2嵌合Fab抗体对裸鼠肝癌原位移植瘤的治疗作用%Therapeutical effect of chimeric anti-VEGFR-2 Fab antibody on orthotopic xenograft of hepatocellular carcinoma in BALB/c nude mice

    Institute of Scientific and Technical Information of China (English)

    李倩君; 潘峰; 王丙剑; 朱进; 张建民; 吴亚夫; 周传文

    2013-01-01

    目的 检测抗血管内皮生长因子受体2 (VEGFR-2)嵌合Fab抗体对裸鼠肝癌原位移植瘤的治疗作用.方法 40只4周龄雄性BALB/c裸鼠建立肝癌H22细胞移植瘤模型后随机均分为Fab抗体(A)组和生理盐水对照(B)组.比较两组裸鼠生存时间、移植瘤病理变化及微血管密度(MVD).结果 成功建立裸鼠H22肝癌原位移植瘤模型,HE染色显示肝细胞肝癌.A组裸鼠中位数生存时间明显长于B组(20.0 d vs.14.0 d)(P<0.01);A组肝脏实体瘤内MVD较B组显著减少(8.65±1.79 vs.25.64±1.53)(P<0.05).结论 抗VEGFR-2嵌合Fab抗体对裸鼠肝癌原位移植瘤有治疗作用.%Objective To investigate the therapeutical effect of chimeric anti-vascular endothelial growth factor receptor(VEGFR)-2 Fab antibody on orthotopic xenograft in BALB/c nude mice. Methods The orthotopic xenograft model of hepatocellular carcinoma H22 cells was established in 40 nude mice, which were equally randomized into two groups of A (treated with chimeric anti-VEGFR-2 Fab antibody) and B(treated with normal saline). The survival time, pathological changes and microvessel density(MVD) in H22 xenografts were compared between two groups. Results An orthotopic xenograft model of hepatocellular carcinoma was successfully created in nude mice, which was confermed as hepatocellular carcinoma by hematoxylin-eosin staining. The mean survival time was longer in group A than that in group B(20. 0 d vs. 14. 0 d) (P<0. 05). MVD in the xenografts was less in group A than that in group B(8. 65±1. 79 vs. 25. 64±1. 53) (P<0. 05). Conclusion The chimeric anti-VEGFR-2 Fab antibody has some therapeutical effect on an orthotopic xenografts in nude mice.

  15. Phase II study evaluating 2 dosing schedules of oral foretinib (GSK1363089, cMET/VEGFR2 inhibitor, in patients with metastatic gastric cancer.

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    Manish A Shah

    Full Text Available PURPOSE: The receptors for hepatocyte and vascular endothelial cell growth factors (MET and VEGFR2, respectively are critical oncogenic mediators in gastric adenocarcinoma. The purpose is to examine the safety and efficacy of foretinib, an oral multikinase inhibitor targeting MET, RON, AXL, TIE-2, and VEGFR2 receptors, for the treatment of metastatic gastric adenocarcinoma. PATIENTS AND METHODS: Foretinib safety and tolerability, and objective response rate (ORR were evaluated in patients using intermittent (240 mg/day, for 5 days every 2 weeks or daily (80 mg/day dosing schedules. Thirty evaluable patients were required to achieve alpha = 0.10 and beta = 0.2 to test the alternative hypothesis that single-agent foretinib would result in an ORR of ≥ 25%. Up to 10 additional patients could be enrolled to ensure at least eight with MET amplification. Correlative studies included tumor MET amplification, MET signaling, pharmacokinetics and plasma biomarkers of foretinib activity. RESULTS: From March 2007 until October 2009, 74 patients were enrolled; 74% male; median age, 61 years (range, 25-88; 93% had received prior therapy. Best response was stable disease (SD in 10 (23% patients receiving intermittent dosing and five (20% receiving daily dosing; SD duration was 1.9-7.2 months (median 3.2 months. Of 67 patients with tumor samples, 3 had MET amplification, one of whom had SD. Treatment-related adverse events occurred in 91% of patients. Rates of hypertension (35% vs. 15% and elevated aspartate aminotransferase (23% vs. 8% were higher with intermittent dosing. In both patients with high baseline tumor phospho-MET (pMET, the pMET:total MET protein ratio decreased with foretinib treatment. CONCLUSION: These results indicate that few gastric carcinomas are driven solely by MET and VEGFR2, and underscore the diverse molecular oncogenesis of this disease. Despite evidence of MET inhibition by foretinib, single-agent foretinib lacked efficacy in

  16. Specific Targeting of Tumor Endothelial Cells by a Shiga-like Toxin-Vascular Endothelial Growth Factor Fusion Protein as a Novel Treatment Strategy for Pancreatic Cancer

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    Birgit Hotz

    2010-10-01

    Full Text Available PURPOSE: Tumor endothelial cells express vascular endothelial growth factor receptor 2 (VEGFR-2. VEGF can direct toxins to tumor vessels through VEGFR-2 for antiangiogenic therapy. This study aimed to selectively damage the VEGFR-2-overexpressing vasculature of pancreatic cancer by SLT-VEGF fusion protein comprising VEGF and the A subunit of Shiga-like toxin which inhibits protein synthesis of cells with high VEGFR-2 expression. EXPERIMENTAL DESIGN: Expression of VEGF and VEGF receptors was evaluated in human pancreatic cancer cells (AsPC-1, HPAF-2 and in normal human endothelial cells (HUVEC by reverse transcription-polymerase chain reaction. Cells were treated with SLT-VEGF (0.1–10 nM, and cell viability, proliferation, and endothelial tube formation were assessed. Orthotopic pancreatic cancer (AsPC-1, HPAF-2 was induced in nude mice. Animals were treated with SLT-VEGF fusion protein alone or in combination with gemcitabine. Treatment began 3 days or 6 weeks after tumor induction. Primary tumor volume and dissemination were determined after 14 weeks. Microvessel density and expression of VEGF and VEGF receptors were analyzed by immunohistochemistry. RESULTS: SLT-VEGF did not influence proliferation of pancreatic cancer cells; HUVECs (low-level VEGFR-2 reduced their proliferation rate and tube formation but not their viability. SLT-VEGF fusion protein reduced tumor growth and dissemination, increasing 14-week survival (AsPC-1, up to 75%; HPAF-2, up to 83%. Results of gemcitabine were comparable with SLT-VEGF monotherapy. Combination partly increased the therapeutic effects in comparison to the respective monotherapies. Microvessel density was reduced in all groups. Intratumoral VEGFR-2 expression was found in endothelial but not in tumor cells. CONCLUSIONS: SLT-VEGF is toxic for tumor vasculature rather than for normal endothelial or pancreatic cancer cells. SLT-VEGF treatment in combination with gemcitabine may provide a novel approach for

  17. Fragment virtual screening based on Bayesian categorization for discovering novel VEGFR-2 scaffolds.

    Science.gov (United States)

    Zhang, Yanmin; Jiao, Yu; Xiong, Xiao; Liu, Haichun; Ran, Ting; Xu, Jinxing; Lu, Shuai; Xu, Anyang; Pan, Jing; Qiao, Xin; Shi, Zhihao; Lu, Tao; Chen, Yadong

    2015-11-01

    The discovery of novel scaffolds against a specific target has long been one of the most significant but challengeable goals in discovering lead compounds. A scaffold that binds in important regions of the active pocket is more favorable as a starting point because scaffolds generally possess greater optimization possibilities. However, due to the lack of sufficient chemical space diversity of the databases and the ineffectiveness of the screening methods, it still remains a great challenge to discover novel active scaffolds. Since the strengths and weaknesses of both fragment-based drug design and traditional virtual screening (VS), we proposed a fragment VS concept based on Bayesian categorization for the discovery of novel scaffolds. This work investigated the proposal through an application on VEGFR-2 target. Firstly, scaffold and structural diversity of chemical space for 10 compound databases were explicitly evaluated. Simultaneously, a robust Bayesian classification model was constructed for screening not only compound databases but also their corresponding fragment databases. Although analysis of the scaffold diversity demonstrated a very unevenly distribution of scaffolds over molecules, results showed that our Bayesian model behaved better in screening fragments than molecules. Through a literature retrospective research, several generated fragments with relatively high Bayesian scores indeed exhibit VEGFR-2 biological activity, which strongly proved the effectiveness of fragment VS based on Bayesian categorization models. This investigation of Bayesian-based fragment VS can further emphasize the necessity for enrichment of compound databases employed in lead discovery by amplifying the diversity of databases with novel structures.

  18. The effect of platelet rich plasma on angiogenesis in ischemic flaps in VEGFR2-luc mice.

    Science.gov (United States)

    Sönmez, Tolga Taha; Vinogradov, Alexandra; Zor, Fatih; Kweider, Nisreen; Lippross, Sebastian; Liehn, Elisa Anamaria; Naziroglu, Mustafa; Hölzle, Frank; Wruck, Christoph; Pufe, Thomas; Tohidnezhad, Mersedeh

    2013-04-01

    To improve skin flap healing, one promising strategy in reconstructive surgery might be to optimize platelet rich plasma (PRP) bioactivity and the ischemia-altered expression of genes. We studied both the effect of PRP on ischemic flaps, and whether in vivo bioluminescence imaging (BLI) is a suitable method for the longitudinal monitoring of angiogenesis in surgical wounds. Axial murine skin flaps were created in four experimental groups. In vivo measurements of VEGFR2 expression levels were made every other day until the 14th day. The local VEGF level and microvessel density were quantified on the 14th day via ELISA and immunohistochemistry, and flap survival rates were measured. We demonstrated that PRP and induced ischemia have a beneficial influence on angiogenesis and flap healing. Combining the two resulted in a significantly robust increase in angiogenesis and flap survival rate that was corroborated by bioluminescence imaging of VEGFR2 activity. This study shows that angiogenic effects of PRP may be potentialized by the stimulus of induced ischemia during free flap harvesting, and thus the two procedures appear to have a synergistic effect on flap healing. This study further demonstrates that BLI of modulated genes in reconstructive surgery is a valuable model for longitudinal in vivo evaluation of angiogenesis.

  19. Human epidermal growth factor receptor-2 in oesophageal cancers: An observational study

    Institute of Scientific and Technical Information of China (English)

    Hazem Al-Momani; Rachel Barnes; Ahmed El-Hadi; Rachit Shah; Wyn G Lewis; Paul Edwards

    2012-01-01

    AIM:To determine the incidence of human epidermal growth factor receptor 2 (HER2) over expression in oesophageal cancers.METHODS:A retrospective study,of one hundred consecutive cases of endoscopic histological samples of oesophageal cancers from a single British cancer network were included.Cancer cases were diagnosed between April 2007 and June 2010.HER2 over expression was assessed using immunohistochemistry,those that scored "0" and "+1" were considered "negative"for HER2; those that scored "+3" were considered "Positive".Cases that were scored "+2" on immunohistochemistry further went on to have HER2 gene analysis using the Ventana HER brightfield dual-colour in situ hybridisations (HER B DISH) assay and either came back to be positive or negative for HER2 over expression.Overall survival was measured from date of histological diagnosis until date of death.93% of the cases were followed up till five years or death,and all were followed up till two years.Cases of gastro-oesophageal junctional tumours were excluded.RESULTS:The median age of our sample was 66years (range:38-91 years).Eighty one were male and 19 female.Ninety-one of the cases were adenocarcinoma of the oesophagus and the rest were cases of squamous cell carcinoma.The anatomical distribution of the tumours was; upper oesophagus 2,middle oesophagus 11,and 87 were in the lower oesophagus.Operative resection was completed in 15 cases; seven cases had attempted surgical resections,i.e.,open and close,33 patients received definitive chemo-radiation and 52 had palliative treatment.Twenty-five of the cancers showed evidence of HER2 over expression,all were adenocarcinomas.Of the 25 cases that showed evidence of HER2 over expression,21 (84%) were located in the lower third of the oesophagus.On staging,24 out of the 25 HER2 positive cases were at stage 3or more (13 at stage 3 and 11 at stage 4),For HER2 negative cases 37 were at stage 3 and 32 were staged as stage 4.Seventeen out of twenty five cases

  20. The high angiogenic activity in very early breast cancer enables reliable imaging with VEGFR2-targeted microbubbles (BR55).

    Science.gov (United States)

    Bzyl, Jessica; Palmowski, Moritz; Rix, Anne; Arns, Susanne; Hyvelin, Jean-Marc; Pochon, Sibylle; Ehling, Josef; Schrading, Simone; Kiessling, Fabian; Lederle, Wiltrud

    2013-02-01

    Tumour xenografts of well-discernible sizes can be examined well by molecular ultrasound. Here, we investigated whether very early breast carcinomas express sufficient levels of VEGFR2 for reliable molecular ultrasound imaging with targeted microbubbles. MCF-7 breast cancer xenografts were orthotopically implanted in nude mice (n = 26). Tumours measuring from 4 mm(3) (2 mm diameter) up to 65 mm(3) (5 mm diameter) were examined with automated 3D molecular ultrasound using clinically translatable VEGFR2-targeted microbubbles (BR55). Additionally, the relative tumour blood volume was assessed with non-targeted microbubbles (BR38). In vivo ultrasound data were validated by quantitative immunohistochemistry. Very small lesions 2 mm in diameter showed the highest binding of VEGFR2-specific microbubbles. In larger tumours significantly less BR55 accumulated (p = 0.023). Nonetheless, binding of VEGFR2-targeted microbubbles was still high enough for imaging. The relative blood volume was comparable at all tumour sizes. Both findings were confirmed by immunohistochemistry. Additionally, a significantly enhanced number of large and mature vessels were detected with increasing tumour size (p < 0.01), explaining the decrease in VEGFR2 expression during tumour growth. 3D molecular ultrasound using BR55 is very well suited to depicting the angiogenic activity in very small breast lesions, suggesting its potential for detecting and characterising these lesions.

  1. VEGFR2-mediated vascular dilation as a mechanism of VEGF-induced anemia and bone marrow cell mobilization.

    Science.gov (United States)

    Lim, Sharon; Zhang, Yin; Zhang, Danfang; Chen, Fang; Hosaka, Kayoko; Feng, Ninghan; Seki, Takahiro; Andersson, Patrik; Li, Jingrong; Zang, Jingwu; Sun, Baocun; Cao, Yihai

    2014-10-23

    Molecular mechanisms underlying tumor VEGF-induced host anemia and bone marrow cell (BMC) mobilization remain unknown. Here, we report that tumor VEGF markedly induced sinusoidal vasculature dilation in bone marrow (BM) and BMC mobilization to tumors and peripheral tissues in mouse and human tumor models. Unexpectedly, anti-VEGFR2, but not anti-VEGFR1, treatment completely blocked VEGF-induced anemia and BMC mobilization. Genetic deletion of Vegfr2 in endothelial cells markedly ablated VEGF-stimulated BMC mobilization. Conversely, deletion of the tyrosine kinase domain from Vegfr1 gene (Vegfr1(TK-/-)) did not affect VEGF-induced BMC mobilization. Analysis of VEGFR1(+)/VEGFR2(+) populations in peripheral blood and BM showed no significant ratio difference between VEGF- and control tumor-bearing animals. These findings demonstrate that vascular dilation through the VEGFR2 signaling is the mechanism underlying VEGF-induced BM mobilization and anemia. Thus, our data provide mechanistic insights on VEGF-induced BMC mobilization in tumors and have therapeutic implications by targeting VEGFR2 for cancer therapy.

  2. The P2Y2 Receptor Interacts with VE-Cadherin and VEGF Receptor-2 to Regulate Rac1 Activity in Endothelial Cells.

    Science.gov (United States)

    Liao, Zhongji; Cao, Chen; Wang, Jianjie; Huxley, Virginia H; Baker, Olga; Weisman, Gary A; Erb, Laurie

    2014-12-01

    Vascular endothelial cadherin (VE-cadherin) mediates homophylic adhesion between endothelial cells and is an important regulator of angiogenesis, blood vessel permeability and leukocyte trafficking. Rac1, a member of the Rho family of GTPases, controls VE-cadherin adhesion by acting downstream of several growth factors, including angiopoietin-1 and vascular endothelial growth factor (VEGF). Here we show that UTP-induced activation of the Gq protein-coupled P2Y2 nucleotide receptor (P2Y2R) in human coronary artery endothelial cells (HCAECs) activated Rac1 and caused a transient complex to form between P2Y2R, VE-cadherin and VEGF receptor-2 (VEGFR-2). Knockdown of VE-cadherin expression with siRNA did not affect UTP-induced activation of extracellular signal-regulated kinases 1/2 (ERK1/2) but led to a loss of UTP-induced Rac1 activation and tyrosine phosphorylation of p120 catenin, a cytoplasmic protein known to interact with VE-cadherin. Activation of the P2Y2R by UTP also caused a prolonged interaction between p120 catenin and vav2 (a guanine nucleotide exchange factor for Rac) that correlated with the kinetics of UTP-induced tyrosine phosphorylation of p120 catenin and VE-cadherin. Inhibitors of VEGFR-2 (SU1498) or Src (PP2) significantly diminished UTP-induced Rac1 activation, tyrosine phosphorylation of p120 catenin and VE-cadherin, and association of the P2Y2R with VE-cadherin and p120 catenin with vav2. These findings suggest that the P2Y2R uses Src and VEGFR-2 to mediate association of the P2Y2R with VE-cadherin complexes in endothelial adherens junctions to activate Rac1.

  3. K20E, an oxidative-coupling compound of methyl caffeate, exhibits anti-angiogenic activities through down-regulations of VEGF and VEGF receptor-2

    Energy Technology Data Exchange (ETDEWEB)

    Pan, Chun-Hsu [Department of Pharmacy, Taipei Medical University, Taipei 11031, Taiwan (China); Lin, Wen-Hsin; Chien, Yi-Chung; Liu, Fon-Chang; Sheu, Ming-Jyh [School of Pharmacy, China Medical University, Taichung 40402, Taiwan (China); Kuo, Yueh-Hsiung, E-mail: kuoyh@mail.cmu.edu.tw [Tsuzuki Institute for Traditional Medicine, China Medical University, Taichung 40402, Taiwan (China); Department of Chinese Pharmaceutical Sciences and Chinese Medicine Resources, China Medical University, Taichung 40402, Taiwan (China); Department of Biotechnology, Asia University, Taichung 41354, Taiwan (China); Wu, Chieh-Hsi, E-mail: chhswu@tmu.edu.tw [Department of Pharmacy, Taipei Medical University, Taipei 11031, Taiwan (China); School of Pharmacy, China Medical University, Taichung 40402, Taiwan (China); Department of Biological Science and Technology, China Medical University, Taichung 40402, Taiwan (China)

    2015-01-15

    Anti-angiogenesis is one of the most popular clinical interventions for cancer chemotherapy. A series of synthesized derivative of methyl caffeate were used to evaluate the anti-angiogenic activity and to investigate possible pharmacological mechanisms in the present study. The most potent anti-angiogenic compound was evaluated in the experiments of murine allograft tumor model and Matrigel plug assay as well as cell models in the human umbilical vascular endothelial cells (HUVECs) and the LLC1 lung cancer cells. Our results suggested that K20E suppressed the tumor growth in the allograft tumor model and exhibited anti-angiogenic activity in Matrigel plug assay. Besides, HUVEC viability was found to be significantly reduced by arresting cell cycle at G{sub 2}/M phase and apoptosis. Cell migration, invasion, and tube formation of the HUVECs were also markedly suppressed by K20E treatment. K20E largely down-regulated the intracellular and secreted vascular endothelial growth factor (VEGF) in the LLC1 cancer cells. Besides, VEGF receptor-2 (VEGFR-2) and its downstream signaling cascades (AKT-mTOR and MEK1/2-ERK1/2) as well as gelatinases were all evidently reduced in the HUVECs treated with K20E. Inversely, K20E can up-regulate the expression levels of p53 and p21 proteins in the HUVECs. Based on these results, our study suggested that K20E possessed inhibiting angiogenesis through regulation of VEGF/VEGFR-2 and its downstream signaling cascades in the vascular endothelial cells (VECs). - Highlights: • K20E is an oxidative-coupling compound of methyl caffeate. • K20E exhibits anti-tumor and anti-angiogenesis effects. • K20E suppresses the expressions of VEGF and VEGF receptor-2 (VEGFR-2) proteins. • K20E deactivates VEGFR-2-mediated downstream signaling pathways to inhibit angiogenesis. • K20E up-regulates p53-p21 pathway to induce apoptosis and cell arrest at G2/M phase.

  4. Fibroblast Growth Factor 10-Fibroblast Growth Factor Receptor 2b Mediated Signaling Is Not Required for Adult Glandular Stomach Homeostasis

    Science.gov (United States)

    Sala, Frederic G.; Ford, Henri R.; Bellusci, Saverio; Grikscheit, Tracy C.

    2012-01-01

    The signaling pathways that are essential for gastric organogenesis have been studied in some detail; however, those that regulate the maintenance of the gastric epithelium during adult homeostasis remain unclear. In this study, we investigated the role of Fibroblast growth factor 10 (FGF10) and its main receptor, Fibroblast growth factor receptor 2b (FGFR2b), in adult glandular stomach homeostasis. We first showed that mouse adult glandular stomach expressed Fgf10, its receptors, Fgfr1b and Fgfr2b, and most of the other FGFR2b ligands (Fgf1, Fgf7, Fgf22) except for Fgf3 and Fgf20. Fgf10 expression was mesenchymal whereas FGFR1 and FGFR2 expression were mostly epithelial. Studying double transgenic mice that allow inducible overexpression of Fgf10 in adult mice, we showed that Fgf10 overexpression in normal adult glandular stomach increased epithelial proliferation, drove mucous neck cell differentiation, and reduced parietal and chief cell differentiation. Although a similar phenotype can be associated with the development of metaplasia, we found that Fgf10 overexpression for a short duration does not cause metaplasia. Finally, investigating double transgenic mice that allow the expression of a soluble form of Fgfr2b, FGF10's main receptor, which acts as a dominant negative, we found no significant changes in gastric epithelial proliferation or differentiation in the mutants. Our work provides evidence, for the first time, that the FGF10-FGFR2b signaling pathway is not required for epithelial proliferation and differentiation during adult glandular stomach homeostasis. PMID:23133671

  5. Fibroblast growth factor 10-fibroblast growth factor receptor 2b mediated signaling is not required for adult glandular stomach homeostasis.

    Directory of Open Access Journals (Sweden)

    Allison L Speer

    Full Text Available The signaling pathways that are essential for gastric organogenesis have been studied in some detail; however, those that regulate the maintenance of the gastric epithelium during adult homeostasis remain unclear. In this study, we investigated the role of Fibroblast growth factor 10 (FGF10 and its main receptor, Fibroblast growth factor receptor 2b (FGFR2b, in adult glandular stomach homeostasis. We first showed that mouse adult glandular stomach expressed Fgf10, its receptors, Fgfr1b and Fgfr2b, and most of the other FGFR2b ligands (Fgf1, Fgf7, Fgf22 except for Fgf3 and Fgf20. Fgf10 expression was mesenchymal whereas FGFR1 and FGFR2 expression were mostly epithelial. Studying double transgenic mice that allow inducible overexpression of Fgf10 in adult mice, we showed that Fgf10 overexpression in normal adult glandular stomach increased epithelial proliferation, drove mucous neck cell differentiation, and reduced parietal and chief cell differentiation. Although a similar phenotype can be associated with the development of metaplasia, we found that Fgf10 overexpression for a short duration does not cause metaplasia. Finally, investigating double transgenic mice that allow the expression of a soluble form of Fgfr2b, FGF10's main receptor, which acts as a dominant negative, we found no significant changes in gastric epithelial proliferation or differentiation in the mutants. Our work provides evidence, for the first time, that the FGF10-FGFR2b signaling pathway is not required for epithelial proliferation and differentiation during adult glandular stomach homeostasis.

  6. Fibroblast growth factor 10-fibroblast growth factor receptor 2b mediated signaling is not required for adult glandular stomach homeostasis.

    Science.gov (United States)

    Speer, Allison L; Al Alam, Denise; Sala, Frederic G; Ford, Henri R; Bellusci, Saverio; Grikscheit, Tracy C

    2012-01-01

    The signaling pathways that are essential for gastric organogenesis have been studied in some detail; however, those that regulate the maintenance of the gastric epithelium during adult homeostasis remain unclear. In this study, we investigated the role of Fibroblast growth factor 10 (FGF10) and its main receptor, Fibroblast growth factor receptor 2b (FGFR2b), in adult glandular stomach homeostasis. We first showed that mouse adult glandular stomach expressed Fgf10, its receptors, Fgfr1b and Fgfr2b, and most of the other FGFR2b ligands (Fgf1, Fgf7, Fgf22) except for Fgf3 and Fgf20. Fgf10 expression was mesenchymal whereas FGFR1 and FGFR2 expression were mostly epithelial. Studying double transgenic mice that allow inducible overexpression of Fgf10 in adult mice, we showed that Fgf10 overexpression in normal adult glandular stomach increased epithelial proliferation, drove mucous neck cell differentiation, and reduced parietal and chief cell differentiation. Although a similar phenotype can be associated with the development of metaplasia, we found that Fgf10 overexpression for a short duration does not cause metaplasia. Finally, investigating double transgenic mice that allow the expression of a soluble form of Fgfr2b, FGF10's main receptor, which acts as a dominant negative, we found no significant changes in gastric epithelial proliferation or differentiation in the mutants. Our work provides evidence, for the first time, that the FGF10-FGFR2b signaling pathway is not required for epithelial proliferation and differentiation during adult glandular stomach homeostasis.

  7. 8-THP-DHI analogs as potent Type I dual TIE-2/VEGF-R2 receptor tyrosine kinase inhibitors.

    Science.gov (United States)

    Hudkins, Robert L; Zulli, Allison L; Underiner, Ted L; Angeles, Thelma S; Aimone, Lisa D; Meyer, Sheryl L; Pauletti, Daniel; Chang, Hong; Fedorov, Elena V; Almo, Steven C; Fedorov, Alexander A; Ruggeri, Bruce A

    2010-06-01

    A novel series of 8-(2-tetrahydropyranyl)-12,13-dihydroindazolo[5,4-a]pyrrolo[3,4-c]carbazoles (THP-DHI) was synthesized and evaluated as dual TIE-2 and VEGF-R2 receptor tyrosine kinase inhibitors. Development of the structure-activity relationships (SAR) with the support of X-ray crystallography led to identification of 7f and 7g as potent, selective dual TIE-2/VEGF-R2 inhibitors with excellent cellular potency and acceptable pharmacokinetic properties. Compounds 7f and 7g were orally active in tumor models with no observed toxicity.

  8. β肾上腺素受体和血管内皮生长因子受体在婴幼儿血管瘤组织中的表达%The expression and significance of β2-AR and VEGFR-2 in infantile hemangioma

    Institute of Scientific and Technical Information of China (English)

    徐广琪; 牛静静; 吕仁荣; 周生儒; 霍然

    2014-01-01

    目的 检测不同时期婴幼儿血管瘤组织中β肾上腺素受体-2和血管内皮生长因子受体-2的表达,并探讨两者在血管瘤的病理演变过程中的意义.方法 按照Mulliken分类法将血管瘤分为三期:增生期(<12个月)32例,消退期(13 ~ 60个月)17例和消退完成期(61个月至12岁)11例;另收集7例瘤旁正常皮肤作为对照.通过免疫组化法检测增生期、消退期、消退完成期婴幼儿血管瘤组织中β肾上腺素受体-2和血管内皮生长因子受体-2的表达情况,并利用计算机图像分析技术(Image Pro Plus 6.0软件)测量平均吸光度值.数据统计以均数±标准差表示,采用SPSS16.0软件对定量结果进行单因素方差分析.结果 β肾上腺素受体-2在增生期血管瘤呈强阳性表达、消退期呈阳性表达、消退完成期呈弱阳性表达,在各期平均吸光度值分别为0.064 751 2±0.012 747、0.031 601 7±0.006 848、0.011 869 8±0.039 349;血管内皮生长因子受体-2在血管瘤增生期呈强阳性表达、消退期呈阳性表达、消退完成期呈弱阳性表达,在各期平均吸光度值分别为0.068 940 9±0.029 274、0.028 445 5±0.006 396、0.011 184 1±0.004 198;各期之间差异有统计学意义(P <0.05);β肾上腺素受体-2与血管内皮细胞生长因子受体-2平均吸光度值的相关性分析具有统计学意义(P<0.05).结论 β肾上腺素受体-2和血管内皮生长因子受体-2可能参与了血管瘤发生、发展及消退的病理过程.%Objective To investigate the significance of β-adrenergic receptor 2 (β2-AR) and vascular endothelial growth factor-2 (VEGFR-2) in the occurrence and development of infantile hemangioma through detecting the expression of β2-AR and VEGFR-2 in the different stages of infantile hemangiomas.Methods According to the Mulliken's classification standard,we classified the specimens as proliferating group (32 cases),involuting group (17 cases) and involuted group (11 cases

  9. Comparative analysis of evolutionarily conserved motifs of epidermal growth factor receptor 2 (HER2) predicts novel potential therapeutic epitopes

    DEFF Research Database (Denmark)

    Deng, Xiaohong; Zheng, Xuxu; Yang, Huanming;

    2014-01-01

    Overexpression of human epidermal growth factor receptor 2 (HER2) is associated with tumor aggressiveness and poor prognosis in breast cancer. With the availability of therapeutic antibodies against HER2, great strides have been made in the clinical management of HER2 overexpressing breast cancer...... for potential therapeutic application. Thus, this novel computational process for predicting or searching for potential epitopes or key target sites may contribute to epitope-based vaccine and function-selected drug design, especially when x-ray crystal structure protein data is not available....

  10. Combinatory action of VEGFR2 and MAP kinase pathways maintains endothelial-cell integrity

    Institute of Scientific and Technical Information of China (English)

    Hanbing Zhong; Danyang Wang; Nan Wang; Yesenia Rios; Haigen Huang; Song Li; Xinrong Wu; Shuo Lin

    2011-01-01

    Blood vessels normally maintain stereotyped lumen diameters and their stable structures are crucial for vascular function. However, very little is known about the molecular mechanisms controlling the maintenance of vessel diameters and the integrity of endothelial cells. We investigated this issue in zebrafish embryos by a chemical genetics approach. Small molecule libraries were screened using live Tg(kdrl:GRCFP)zn1 transgenic embryos in which endothelial cells are specifically labeled with GFP. By analyzing the effects of compounds on the morphology and function of embryonic blood vessels after lumen formation, PP1, a putative Src kinase inhibitor, was identified as capable of specifically reducing vascular lumen size by interrupting endothelial-cell integrity. The inhibitory effect is not due to Src or general VEGF signaling inhibition because another Src inhibitor and Src morpholino as well as several VEGFR inhibitors failed to produce a similar phenotype. After profiling a panel of 22 representative mammalian kinases and surveying published data, we selected a few possible new candidates. Combinational analysis of these candidate kinase inhibitors established that PP1 induced endothelial collapse by inhibiting both the VEGFR2 and MAP kinase pathways. More importantly, combinatory use of two clinically approved drugs Dasatinib and Sunitinib produced the same phenotype. This is the first study to elucidate the pathways controlling maintenance of endothelial integrity using a chemical genetics approach, indicating that endothelial integrity is controlled by the combined action of the VEGFR2 and MAP kinase pathways. Our results also suggest the possible side effect of the combination of two anticancer drugs on the circulatory system.

  11. Hsp20 functions as a novel cardiokine in promoting angiogenesis via activation of VEGFR2.

    Directory of Open Access Journals (Sweden)

    Xiaowei Zhang

    Full Text Available Heat shock proteins (Hsps are well appreciated as intrinsic protectors of cardiomyocytes against numerous stresses. Recent studies have indicated that Hsp20 (HspB6, a small heat shock protein, was increased in blood from cardiomyopathic hamsters. However, the exact source of the increased circulating Hsp20 and its potential role remain obscure. In this study, we observed that the circulating Hsp20 was increased in a transgenic mouse model with cardiac-specific overexpression of Hsp20, compared with wild-type mice, suggesting its origin from cardiomyocytes. Consistently, culture media harvested from Hsp20-overexpressing cardiomyocytes by Ad.Hsp20 infection contained an increased amount of Hsp20, compared to control media. Furthermore, we identified that Hsp20 was secreted through exosomes, independent of the endoplasmic reticulum-Golgi pathway. To investigate whether extracellular Hsp20 promotes angiogenesis, we treated human umbilical vein endothelial cells (HUVECs with recombinant human Hsp20 protein, and observed that Hsp20 dose-dependently promoted HUVEC proliferation, migration and tube formation. Moreover, a protein binding assay and immunostaining revealed an interaction between Hsp20 and VEGFR2. Accordingly, stimulatory effects of Hsp20 on HUVECs were blocked by a VEGFR2 neutralizing antibody and CBO-P11 (a VEGFR inhibitor. These in vitro data are consistent with the in vivo findings that capillary density was significantly enhanced in Hsp20-overexpressing hearts, compared to non-transgenic hearts. Collectively, our findings demonstrate that Hsp20 serves as a novel cardiokine in regulating myocardial angiogenesis through activation of the VEGFR signaling cascade.

  12. Vascular endothelial growth factor-C induces osteogenic differentiation of human mesenchymal stem cells through the ERK and RUNX2 pathway.

    Science.gov (United States)

    Murakami, Juri; Ishii, Masakazu; Suehiro, Fumio; Ishihata, Kiyohide; Nakamura, Norifumi; Nishimura, Masahiro

    2017-03-11

    Vascular endothelial cell growth factor C (VEGF-C) is a member of the VEGF family and plays a role in a variety of biological activities including lymphangiogenesis, angiogenesis, and neurogenesis through VEGF receptor 2 (VEGFR2) and 3 (VEGFR3). However, it has not been elucidated whether VEGF-C promotes osteogenic differentiation. Herein, we investigated the effects of VEGF-C on osteogenic differentiation in human mesenchymal stem cells (MSCs) and evaluated the underlying molecular mechanisms. VEGF-C treatment significantly increased RUNX2 expression, and led to the promotion of osteogenic marker gene expression and mineralization of MSCs. VEGF-C treatment induced the phosphorylation of VEGFR2 and VEGFR3 in MSCs. Treatment with the VEGFR3-specific ligand VEGF-C156S also promoted MSC mineralization. Furthermore, co-treatment with VEGFR2 and VEGFR3 kinase inhibitors blocked VEGF-C-induced MSC mineralization. VEGF-C treatment activated ERK signaling in MSCs, and inhibition of ERK signaling effectively suppressed VEGF-C-induced RUNX2 expression and mineralization. These results indicate that VEGF-C-induced MSC osteogenesis is mediated through VEGFR2 and VEGFR3, and followed the activation of the ERK/RUNX2 signaling pathway.

  13. Discovery of quinazolin-4-amines bearing benzimidazole fragments as dual inhibitors of c-Met and VEGFR-2.

    Science.gov (United States)

    Shi, Lei; Wu, Ting-Ting; Wang, Zhi; Xue, Jia-Yu; Xu, Yun-Gen

    2014-09-01

    Both c-Met and VEGFR-2 are important targets for the treatment of cancers. In this study, a series of N-(2-phenyl-1H-benzo[d]imidazol-5-yl)quinazolin-4-amine derivatives were designed and identified as dual c-Met and VEGFR-2 inhibitors. Among these compounds bearing quinazoline and benzimidazole fragments, compound 7j exhibited the most potent inhibitory activity against c-Met and VEGFR-2 with IC50 of 0.05μM and 0.02μM, respectively. It also showed the highest anticancer activity against the tested cancer cell lines with IC50 of 1.5μM against MCF-7 and 8.7μM against Hep-G2. Docking simulation supported the initial pharmacophoric hypothesis and suggested a common mode of interaction at the ATP-binding site of c-Met and VEGFR-2, which demonstrates that compound 7j is a potential agent for cancer therapy deserving further researching.

  14. VEGFR2-Targeted Three-Dimensional Ultrasound Imaging Can Predict Responses to Antiangiogenic Therapy in Preclinical Models of Colon Cancer.

    Science.gov (United States)

    Zhou, Jianhua; Wang, Huaijun; Zhang, Huiping; Lutz, Amelie M; Tian, Lu; Hristov, Dimitre; Willmann, Jürgen K

    2016-07-15

    Three-dimensional (3D) imaging capabilities to assess responses to anticancer therapies are needed to minimize sampling errors common to two-dimensional approaches as a result of spatial heterogeneity in tumors. Recently, the feasibility and reproducibility of 3D ultrasound molecular imaging (3D USMI) using contrast agents, which target molecular markers, have greatly improved, due to the development of clinical 3D matrix array transducers. Here we report preclinical proof-of-concept studies showing that 3D USMI of VEGFR2/KDR expression accurately gauges longitudinal treatment responses to antiangiogenesis therapy in responding versus nonresponding mouse models of colon cancer. Tumors in these models exhibited differential patterns of VEGFR2-targeted 3D USMI signals during the course of antiangiogenic treatment with bevacizumab. In responding tumors, the VEGFR2 signal decreased as soon as 24 hours after therapy was started, whereas in nonresponding tumors there was no change in signal at any time point. The early decrease in VEGFR2 signal was highly predictive of treatment outcome at the end of therapy. Our results offer preclinical proof that 3D USMI can predict responses to antiangiogenic therapy, warranting further investigation of its clinical translatability to predicting treatment outcomes in patients. Cancer Res; 76(14); 4081-9. ©2016 AACR.

  15. Requirement for Tumor Necrosis Factor Receptor 2 Expression on Vascular Cells To Induce Experimental Cerebral Malaria

    OpenAIRE

    Stoelcker, Benjamin; Hehlgans, Thomas; Weigl, Karin; Bluethmann, Horst; Grau, Georges E.; Männel, Daniela N

    2002-01-01

    Using tumor necrosis factor receptor type 2 (TNFR2)-deficient mice and generating bone marrow chimeras which express TNFR2 on either hematopoietic or nonhematopoietic cells, we demonstrated the requirement for TNFR2 expression on tissue cells to induce lethal cerebral malaria. Thus, TNFR2 on the brain vasculature mediates tumor necrosis factor-induced neurovascular lesions in experimental cerebral malaria.

  16. Quercetin Inhibits Angiogenesis Mediated Human Prostate Tumor Growth by Targeting VEGFR- 2 Regulated AKT/mTOR/P70S6K Signaling Pathways

    Science.gov (United States)

    Pratheeshkumar, Poyil; Budhraja, Amit; Son, Young-Ok; Wang, Xin; Zhang, Zhuo; Ding, Songze; Wang, Lei; Hitron, Andrew; Lee, Jeong-Chae; Xu, Mei; Chen, Gang; Luo, Jia; Shi, Xianglin

    2012-01-01

    Angiogenesis is a crucial step in the growth and metastasis of cancers, since it enables the growing tumor to receive oxygen and nutrients. Cancer prevention using natural products has become an integral part of cancer control. We studied the antiangiogenic activity of quercetin using ex vivo, in vivo and in vitro models. Rat aortic ring assay showed that quercetin at non-toxic concentrations significantly inhibited microvessel sprouting and exhibited a significant inhibition in the proliferation, migration, invasion and tube formation of endothelial cells, which are key events in the process of angiogenesis. Most importantly, quercetin treatment inhibited ex vivo angiogenesis as revealed by chicken egg chorioallantoic membrane assay (CAM) and matrigel plug assay. Western blot analysis showed that quercetin suppressed VEGF induced phosphorylation of VEGF receptor 2 and their downstream protein kinases AKT, mTOR, and ribosomal protein S6 kinase in HUVECs. Quercetin (20 mg/kg/d) significantly reduced the volume and the weight of solid tumors in prostate xenograft mouse model, indicating that quercetin inhibited tumorigenesis by targeting angiogenesis. Furthermore, quercetin reduced the cell viability and induced apoptosis in prostate cancer cells, which were correlated with the downregulation of AKT, mTOR and P70S6K expressions. Collectively the findings in the present study suggest that quercetin inhibits tumor growth and angiogenesis by targeting VEGF-R2 regulated AKT/mTOR/P70S6K signaling pathway, and could be used as a potential drug candidate for cancer therapy. PMID:23094058

  17. Quercetin inhibits angiogenesis mediated human prostate tumor growth by targeting VEGFR- 2 regulated AKT/mTOR/P70S6K signaling pathways.

    Directory of Open Access Journals (Sweden)

    Poyil Pratheeshkumar

    Full Text Available Angiogenesis is a crucial step in the growth and metastasis of cancers, since it enables the growing tumor to receive oxygen and nutrients. Cancer prevention using natural products has become an integral part of cancer control. We studied the antiangiogenic activity of quercetin using ex vivo, in vivo and in vitro models. Rat aortic ring assay showed that quercetin at non-toxic concentrations significantly inhibited microvessel sprouting and exhibited a significant inhibition in the proliferation, migration, invasion and tube formation of endothelial cells, which are key events in the process of angiogenesis. Most importantly, quercetin treatment inhibited ex vivo angiogenesis as revealed by chicken egg chorioallantoic membrane assay (CAM and matrigel plug assay. Western blot analysis showed that quercetin suppressed VEGF induced phosphorylation of VEGF receptor 2 and their downstream protein kinases AKT, mTOR, and ribosomal protein S6 kinase in HUVECs. Quercetin (20 mg/kg/d significantly reduced the volume and the weight of solid tumors in prostate xenograft mouse model, indicating that quercetin inhibited tumorigenesis by targeting angiogenesis. Furthermore, quercetin reduced the cell viability and induced apoptosis in prostate cancer cells, which were correlated with the downregulation of AKT, mTOR and P70S6K expressions. Collectively the findings in the present study suggest that quercetin inhibits tumor growth and angiogenesis by targeting VEGF-R2 regulated AKT/mTOR/P70S6K signaling pathway, and could be used as a potential drug candidate for cancer therapy.

  18. Current status of anti-human epidermal growth factor receptor 2 therapies: predicting and overcoming herceptin resistance.

    Science.gov (United States)

    Chung, Alice; Cui, Xiaojiang; Audeh, William; Giuliano, Armando

    2013-08-01

    Human epidermal growth factor receptor 2-overexpressing (HER2+) breast cancer occurs in 20% to 25% of cases and is associated with poor prognosis. Trastuzumab (Herceptin; Genentech, South San Francisco, CA) is a monoclonal antibody targeting the HER2 extracellular domain that has been shown to significantly reduce relapse rates. However, some patients with HER2+ tumors do not respond to Herceptin, and 60% to 85% of patients with HER2+ metastatic breast cancer acquire resistance within a short time period. In this review, we discuss proposed mechanisms of action of trastuzumab and trastuzumab resistance and various drugs that have been developed to overcome drug resistance. We introduce the basal molecular subtype as a predictor of increased risk in HER2+ breast cancer and a possible alternative cause of drug resistance.

  19. Advances in Variations of Estrogen Receptor, Progesterone Receptor and Human Epidermal Growth Factor Receptor-2 Status in Metastatic Breast Cancer

    Institute of Scientific and Technical Information of China (English)

    Yuan Yuan; Zhang Lili

    2013-01-01

    Chemotherapy, endocrine therapy and molecular targeted therapy are vital means in the treatment of metastatic breast cancer (MBC), whose reasonable and standard applications are of great importance to prolong patients’ survival and improve the quality of life. The expressions of estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor-2 (HER-2) present signiifcant differences between primary and metastatic breast cancer. However, these differences may affect the selection of MBC patients for therapeutic strategies and judgment on the prognosis. Hence, the relevant researches on variations of hormone receptors and HER-2 in primary and metastatic breast cancer, discordant causes of ER, PR and HER-2 expression in primary and metastatic lesions and clinical value of biopsy to the metastases are reviewed in the study.

  20. Co-localization of neural cell adhesion molecule and fibroblast growth factor receptor 2 in early embryo development.

    Science.gov (United States)

    Vesterlund, Liselotte; Töhönen, Virpi; Hovatta, Outi; Kere, Juha

    2011-01-01

    During development there is a multitude of signaling events governing the assembly of the developing organism. Receptors for signaling molecules such as fibroblast growth factor receptor 2 (FGFR2) enable the embryo to communicate with the surrounding environment and activate downstream pathways. The neural cell adhesion molecule (NCAM) was first characterized as a cell adhesion molecule highly expressed in the nervous system, but recent studies have shown that it is also a signaling receptor. Using a novel single oocyte adaptation of the proximity ligation assay, we here show a close association between NCAM and FGFR2 in mouse oocytes and 2-cell embryos. Real-time PCR analyses revealed the presence of messenger RNA encoding key proteins in downstream signaling pathways in oocytes and early mouse embryos. In summary these findings show a co-localization of NCAM and FGFR2 in early vertebrate development with intracellular signaling pathways present to enable a cellular response.

  1. The neural cell adhesion molecule binds to fibroblast growth factor receptor 2

    DEFF Research Database (Denmark)

    Christensen, Claus; Lauridsen, Jes B; Berezin, Vladimir;

    2006-01-01

    The neural cell adhesion molecule (NCAM) can bind to and activate fibroblast growth factor receptor 1 (FGFR1). However, there are four major FGFR isoforms (FGFR1-FGFR4), and it is not known whether NCAM also interacts directly with the other three FGFR isoforms. In this study, we show by surface...

  2. Factor Xa stimulates proinflammatory and profibrotic responses in fibroblasts via protease-activated receptor-2 activation

    NARCIS (Netherlands)

    Borensztajn, Keren; Stiekema, Jurrieen; Nijmeijer, Sebastiaan; Reitsmalf, Pieter H.; Peppelenbosch, Maikel P.; Spek, C. Arnold

    Coagulation proteases have been suggested to play a role in the pathogenesis of tissue remodeling and fibrosis. We therefore assessed the proinflammatory and fibroproliferative effects of coagulation protease factor (F)Xa. We show that FXa elicits a signaling response in C2C12 and NIH3T3

  3. Fibroblast growth factor receptor 2 IIIc as a therapeutic target for colorectal cancer cells.

    Science.gov (United States)

    Matsuda, Yoko; Hagio, Masahito; Seya, Tomoko; Ishiwata, Toshiyuki

    2012-09-01

    A high percentage of colorectal carcinomas overexpress a lot of growth factors and their receptors, including fibroblast growth factor (FGF) and FGF receptor (FGFR). We previously reported that FGFR2 overexpression was associated with distant metastasis and that FGFR2 inhibition suppressed cell growth, migration, and invasion. The FGFR2 splicing isoform FGFR2IIIb is associated with well-differentiated histologic type, tumor angiogenesis, and adhesion to extracellular matrices. Another isoform, FGFR2IIIc, correlates with the aggressiveness of various types of cancer. In the present study, we examined the expression and roles of FGFR2IIIc in colorectal carcinoma to determine the effectiveness of FGFR2IIIc-targeting therapy. In normal colorectal tissues, FGFR2IIIc expression was weakly detected in superficial colorectal epithelial cells and was not detected in proliferative zone cells. FGFR2IIIc-positive cells were detected by immunohistochemistry in the following lesions, listed in the order of increasing percentage: hyperplastic polyps growth, soft agar colony formation, migration, and invasion, as well as decreased adhesion to extracellular matrices. Furthermore, FGFR2IIIc-transfected colorectal carcinoma cells formed larger tumors in subcutaneous tissues and the cecum of nude mice. Fully human anti-FGFR2IIIc monoclonal antibody inhibited the growth and migration of colorectal carcinoma cells through alterations in cell migration, cell death, and development-related genes. In conclusion, FGFR2IIIc plays an important role in colorectal carcinogenesis and tumor progression. Monoclonal antibody against FGFR2IIIc has promising potential in colorectal carcinoma therapy.

  4. Activated factor X signaling via protease-activated receptor 2 suppresses pro-inflammatory cytokine production from LPS-stimulated myeloid cells.

    LENUS (Irish Health Repository)

    Gleeson, Eimear M

    2013-07-19

    Vitamin K-dependent proteases generated in response to vascular injury and infection enable fibrin clot formation, but also trigger distinct immuno-regulatory signaling pathways on myeloid cells. Factor Xa, a protease crucial for blood coagulation, also induces protease-activated receptor-dependent cell signaling. Factor Xa can bind both monocytes and macrophages, but whether factor Xa-dependent signaling stimulates or suppresses myeloid cell cytokine production in response to Toll-like receptor activation is not known. In this study, exposure to factor Xa significantly impaired pro-inflammatory cytokine production from lipopolysaccharide-treated peripheral blood mononuclear cells, THP-1 monocytic cells and murine macrophages. Furthermore, factor Xa inhibited nuclear factor-kappa B activation in THP-1 reporter cells, requiring phosphatidylinositide 3-kinase activity for its anti-inflammatory effect. Active-site blockade, γ-carboxyglutamic acid domain truncation and a peptide mimic of the factor Xa inter-epidermal growth factor-like region prevented factor Xa inhibition of lipopolysaccharide-induced tumour necrosis factor-α release. In addition, factor Xa anti-inflammatory activity was markedly attenuated by the presence of an antagonist of protease-activated receptor 2, but not protease-activated receptor 1. The key role of protease-activated receptor 2 in eliciting factor Xa-dependent anti-inflammatory signaling on macrophages was further underscored by the inability of factor Xa to mediate inhibition of tumour necrosis factor-α and interleukin-6 release from murine bone marrow-derived protease-activated receptor 2-deficient macrophages. We also show for the first time that, in addition to protease-activated receptor 2, factor Xa requires a receptor-associated protein-sensitive low-density lipoprotein receptor to inhibit lipopolysaccharide-induced cytokine production. Collectively, this study supports a novel function for factor Xa as an endogenous, receptor

  5. Phosphorylation and lipid raft association of fibroblast growth factor receptor-2 in oligodendrocytes.

    Science.gov (United States)

    Bryant, M R; Marta, C B; Kim, F S; Bansal, R

    2009-07-01

    Fibroblast growth factors (FGFs) and their receptors (FGFRs) initiate diverse cellular responses that contribute to the regulation of oligodendrocyte (OL) function. To understand the mechanisms by which FGFRs elicit these cellular responses, we investigated the phosphorylation of signal transduction proteins and the role of cholesterol-glycosphingolipid-enriched "lipid raft" microdomains in differentiated OLs. Surprisingly, we found that the most abundant tyrosine-phosphorylated protein in OLs was the 120-kd isoform of FGFR2 and that it was phosphorylated even in the absence of FGF2, suggesting a potential ligand-independent function for this receptor. Furthermore, FGFR2, but not FGFR1, was associated with lipid raft microdomains in OLs and myelin (but not in astrocytes). This provides the first evidence for the association of FGFR with TX-100-insoluble lipid raft fractions. FGFR2 phosphorylated the key downstream target, FRS2 in OLs. Raft disruption resulted in loss of phosphorylated FRS2 from lipid rafts, coupled with the loss of Akt but not of Mek or Erk phosphorylation. This suggests that FGFR2-FRS2 signaling in lipid rafts operates via the PI3-Kinase/Akt pathway rather than the Ras/Mek/Erk pathway, emphasizing the importance of microenvironments within the cell membrane. Also present in lipid rafts in OLs and myelin, but not in astrocytes, was a novel 52-kd isoform of FGFR2 that lacked the extracellular ligand-binding region. These results demonstrate that FGFR2 in OLs and myelin possess unique characteristics that are specific both to receptor type and to OLs and provide a novel mechanism to elicit distinct cellular responses that mediate both FGF-dependent and -independent functions.

  6. 下肢慢性缺血患者的超重和肥胖对血浆中VEGF-A、VEGFR-1和VEGFR-2浓度的影响%Overweight and obesity versus concentrations of VEGF-A, sVEGFR-1, and sVEGFR-2 in plasma of patients with lower limb chronic ischemia

    Institute of Scientific and Technical Information of China (English)

    Radosaw WIECZR; Anna Maria WIECZR; Grayna GADOMSKA; Katarzyna STANKOWSKA; Jacek FABISIAK; Karol SUPPAN; Grzegorz PULKOWSKI; Jacek BUDZYSKI; Danuta RO

    2016-01-01

    Objective:Being overweight or obese comprises a significant risk factor for atherosclerosis. Fat tissue also generates factors stimulating angiogenesis, the process by which new blood vessels form. The purpose of this paper is to assess concentrations of the vascular endothelial growth factor A (VEGF-A) and its soluble type-1 and type-2 re-ceptors (sVEGFR-1 and sVEGFR-2) in plasma of patients with peripheral arterial disease (PAD) depending on the level of nutrition according to body mass index (BMI). Methods: The study group included patients suffering from symptomatic PAD (n=46) in Fontaine classes IIa–IV without any history of neoplastic disease and who have a normal BMI (n=15), are overweight (n=21) or are obese (n=10). The control group (n=30) consisted of healthy non-smoking volunteers who were neither overweight nor obese. Venous blood plasma samples were col ected from both groups at rest in the morning to determine plasma concentrations of VEGF-A, sVEGFR-1, and sVEGFR-2 using the enzyme-linked immunosorbent assay (ELISA) method. Results:The group of patients with PAD co-existent with being over-weight or obese tended to have higher mean concentration levels of VEGF-A and sVEGFR-2 when compared with patients suffering from PAD with normal BMI. A statistical y significant positive correlation was obtained between BMI and average plasma concentrations of sVEGFR-2 (R=0.37, P=0.0103). However, no significant correlation was no-ticed between BMI and VEGF-A or sVEGFR-1 concentrations. Conclusions: A positive correlation determined be-tween the level of antiangiogenic factor and BMI value may be indicative of the linearly growing prevalence of some antiangiogenic factors in patients with metabolic disorders, which may be one of numerous factors contributing to incomplete efficiency of collateral circulation development in patients with PAD.%目的:研究外周动脉疾病(PAD)患者血浆中血管内皮生长因子 A(VEGF-A)和它的可溶性1型和2

  7. Granulocyte-macrophage colony-stimulating factor primes interleukin-13 production by macrophages via protease-activated receptor-2.

    Science.gov (United States)

    Aoki, Manabu; Yamaguchi, Rui; Yamamoto, Takatoshi; Ishimaru, Yasuji; Ono, Tomomichi; Sakamoto, Arisa; Narahara, Shinji; Sugiuchi, Hiroyuki; Hirose, Eiji; Yamaguchi, Yasuo

    2015-04-01

    Chronic inflammation is often linked to the presence of type 2-polarized macrophages, which are induced by the T helper type 2 cytokines interleukin-4 and interleukin-13 (IL-13). IL-13 is a key mediator of tissue fibrosis caused by T helper type 2-based inflammation. Human neutrophil elastase (HNE) plays a pivotal role in the pathogenesis of pulmonary fibrosis. This study investigated the priming effect of granulocyte-macrophage colony-stimulating factor (GM-CSF) on IL-13 expression by macrophages stimulated with HNE. Adherent macrophages were obtained from primary cultures of human mononuclear cells. Expression of IL-13 mRNA and protein by GM-CSF-dependent macrophages was investigated after stimulation with HNE, using the polymerase chain reaction and enzyme-linked immunosorbent assay. GM-CSF had a priming effect on IL-13 mRNA and protein expression by macrophages stimulated with HNE, while this effect was not observed for various other cytokines. GM-CSF-dependent macrophages showed a significant increase in the expression of protease activated receptor-2 (PAR-2) mRNA and protein. The response of IL-13 mRNA to HNE was significantly decreased by pretreatment with alpha1-antitrypsin, a PAR-2 antibody (SAM11), or a PAR-2 antagonist (ENMD-1068). These findings suggest that stimulation with HNE can induce IL-13 production by macrophages, especially GM-CSF-dependent macrophages. Accordingly, neutrophil elastase may have a key role in fibrosis associated with chronic inflammation.

  8. Structural model for the interaction of a designed Ankyrin Repeat Protein with the human epidermal growth factor receptor 2.

    Directory of Open Access Journals (Sweden)

    V Chandana Epa

    Full Text Available Designed Ankyrin Repeat Proteins are a class of novel binding proteins that can be selected and evolved to bind to targets with high affinity and specificity. We are interested in the DARPin H10-2-G3, which has been evolved to bind with very high affinity to the human epidermal growth factor receptor 2 (HER2. HER2 is found to be over-expressed in 30% of breast cancers, and is the target for the FDA-approved therapeutic monoclonal antibodies trastuzumab and pertuzumab and small molecule tyrosine kinase inhibitors. Here, we use computational macromolecular docking, coupled with several interface metrics such as shape complementarity, interaction energy, and electrostatic complementarity, to model the structure of the complex between the DARPin H10-2-G3 and HER2. We analyzed the interface between the two proteins and then validated the structural model by showing that selected HER2 point mutations at the putative interface with H10-2-G3 reduce the affinity of binding up to 100-fold without affecting the binding of trastuzumab. Comparisons made with a subsequently solved X-ray crystal structure of the complex yielded a backbone atom root mean square deviation of 0.84-1.14 Ångstroms. The study presented here demonstrates the capability of the computational techniques of structural bioinformatics in generating useful structural models of protein-protein interactions.

  9. Association of human epidermal growth factor receptor 2 status with ipsilateral breast tumor recurrence and resistance to endocrine therapy

    Science.gov (United States)

    ISHITOBI, MAKOTO; SHIBA, MIZUHO; NAKAYAMA, TAKAHIRO; KOYAMA, HIROKI; TAMAKI, YASUHIRO

    2015-01-01

    The effect of prior endocrine therapy on tumor biology and clinical outcomes of locoregional recurrence remains unclear. A total of 76 patients, who underwent salvage breast surgery for estrogen receptor-positive ipsilateral breast tumor recurrence (IBTR) following breast-conserving surgery for primary breast cancer, were retrospectively reviewed to investigate the association of human epidermal growth factor receptor 2 (HER2) status with the characteristics of IBTR and clinical outcomes following resection of IBTR. There was a tendency for more patients with HER2-positive IBTR to show resistance to endocrine therapy (71.4%) compared with those with HER2-negative IBTR (37.3%) (P=0.085). Patients with HER2-positive IBTR exhibited a higher rate of recurrence (62.5%) compared with those with HER2-negative IBTR (25.0%) (P=0.027). These results suggested that HER2-positive IBTR may be associated with resistance to endocrine therapy and a poorer clinical outcome. PMID:26171193

  10. Mammographic features of calcifications in DCIS: correlation with oestrogen receptor and human epidermal growth factor receptor 2 status

    Energy Technology Data Exchange (ETDEWEB)

    Bae, Min Sun; Moon, Woo Kyung; Chang, Jung Min; Cho, Nariya [Seoul National University College of Medicine, Department of Radiology, Seoul (Korea, Republic of); Park, So Yeon; Won, Jae-Kyung; Jeon, Yoon-Kyung; Park, In Ae [Seoul National University College of Medicine, Department of Pathology, Seoul (Korea, Republic of); Moon, Hyeong-Gon; Han, Wonshik [Seoul National University College of Medicine, Department of Surgery, Seoul (Korea, Republic of)

    2013-08-15

    This study investigated the correlation of oestrogen receptor (ER) and human epidermal growth factor receptor 2 (HER2) status with the probability of malignancy (POM) of mammographic calcifications in ductal carcinoma in situ (DCIS). A total of 101 women (age range, 27-83 years) with pure DCIS that presented as mammographic calcifications were included. Three radiologists independently reviewed mammograms according to the BI-RADS lexicon and provided 100-point POM scores and a BI-RADS category. ER, HER2 and breast cancer subtypes were determined using immunohistochemistry (IHC) and fluorescence in situ hybridisation. Pairwise correlations between POM and IHC biomarker scores were calculated, and mammographic features were compared between breast cancer subtypes. HER2 level positively correlated with the POM score (P < 0.0001) and BI-RADS category (P < 0.0001), and ER level inversely correlated with the POM score (P < 0.013) and BI-RADS category (P < 0.010). Fine linear branching (P = 0.004) and segmental (P = 0.014) calcifications were significantly associated with HER2-positive cancers, and clustered calcifications were more frequently observed in ER-positive cancers (P = 0.014). HER2 status in DCIS correlated positively with the POM of mammographic calcifications, as determined by radiologists on the basis of the BI-RADS lexicon. (orig.)

  11. Association between cadmium and breast cancer risk according to estrogen receptor and human epidermal growth factor receptor 2: epidemiological evidence.

    Science.gov (United States)

    Strumylaite, Loreta; Kregzdyte, Rima; Bogusevicius, Algirdas; Poskiene, Lina; Baranauskiene, Dale; Pranys, Darius

    2014-05-01

    The study aimed to examine the association between cadmium (Cd) and the risk of breast cancer according to estrogen receptor (ER) and human epidermal growth factor receptor 2 (HER2). A hospital-based case-control study was carried out in 585 cases and 1,170 controls. Information on possible risk factors was collected via a structured questionnaire. Urinary Cd was determined by atomic absorption spectrometry. The ER and HER2 levels in tumor tissue were analyzed by immunohistochemistry. Logistic regression was used to calculate odds ratios (ORs) and 95 % confidence intervals (CIs) for breast cancer by creatinine-adjusted urinary Cd. Women with greater creatinine-adjusted urine Cd (3rd quartile: 0.241-0.399 μg/g and 4th quartile: ≥ 0.4 μg/g) experienced 1.6 times higher risk of breast cancer compared with those having Cd concentration lower than 0.147 μg/g (1st quartile) [OR = 1.6, (95 % CI 1.19, 2.17) and OR = 1.62 (95 % CI 1.19, 2.21), respectively, P trend = 0.001] after adjustment for age and other confounders. Both ER+ and HER2- cases from the highest quartile of urine Cd exhibited approximately twice the breast cancer risk of those in the lowest quartile [OR = 1.9, (95 % CI 1.31, 2.74) and OR = 1.87, (95 % CI 1.33, 2.62), respectively, P trend cadmium as a risk factor for breast cancer, especially for both ER+ and HER2- cancer patients.

  12. Epidemiologic Study of Human Epidermal Growth Factor Receptor 2 Expression in Advanced/Metastatic Gastric Cancer: an Assessment of Human Epidermal Growth Factor Receptor 2 Status in Tumor Tissue Samples of Gastric and Gastro-Esophageal Junction Cancer

    Science.gov (United States)

    Seo, Kyung Won; Jeon, Taeyong; Kim, Sewon; Kim, Sung Soo; Kim, Kwanghee; Suh, Byoung-Jo; Hwang, Sunhwi; Choi, SeongHee; Ryu, Seungwan; Min, Jae Seok; Lee, Young-Joon; Jee, Ye Seob; Chae, Hyeondong

    2017-01-01

    Purpose The Trastuzumab for gastric cancer (GC) trial identified human epidermal growth factor receptor 2 (HER2) as a predictor of successful treatment with trastuzumab (HER2 receptor targeting agent) among patients with advanced/metastatic GC. To date, the prevalence of HER2 overexpression in the Korean population is unknown. The present study aimed to assess the incidence of HER2 positivity among GC and gastroesophageal (GE) junction cancer samples and the relationship between HER2 overexpression and clinicopathological characteristics in Korean patients. Materials and Methods Tumor samples collected from 1,695 patients with histologically proven GC or GE junction enrolled at 14 different hospitals in Korea were examined. After gathering clinicopathological data of all patients, HER2 status was assessed by immunohistochemistry (IHC) at each hospital, and IHC 2+ cases were subjected to silver-enhanced in situ hybridization at 3 central laboratories. Results A total of 182 specimens tested positive for HER2, whereas 1,505 tested negative. Therefore, the overall HER2-positive rate in this study was 10.8% (95% confidence interval=9.3%–12.3%). The HER2-positive rate was higher among intestinal-type cases (17.6%) than among other types, and was higher among patients older than 70 years and 50 years of age, compared to other age groups. Conclusions Our evaluation of the HER2 positivity rate (10.8%) among Korean patients with GC and GE junction indicated the necessity of epidemiological data when conducting studies related to HER2 expression in GC and GE junction.

  13. Cannabinoid receptor-2 selective antagonist negatively regulates receptor activator of nuclear factor kappa B ligand mediated osteoclastogenesis

    Institute of Scientific and Technical Information of China (English)

    GENG De-chun; XU Yao-zeng; YANG Hui-lin; ZHU Guang-ming; WANG Xian-bin; ZHU Xue-song

    2011-01-01

    Background The cannabinoid receptor-2 (CB2) is important for bone remodeling. In this study, we investigated the effects of CB2 selective antagonist (AM630) on receptor activator of nuclear factor kappa B (RANK) ligand (RANKL)induced osteoclast differentiation and the underlying signaling pathway using a monocyte-macrophage cell line-RAW264.7.Methods RAW264.7 was cultured with RANKL for 6 days and then treated with AM630 for 24 hours. Mature osteoclasts were measured by tartrate-resistant acid phosphatase (TRAP) staining using a commercial kit. Total ribonucleic acid (RNA)was isolated and real-time reverse transcriptase-polymerase chain reaction (RT-PCR) was done to examine the expression of RANK, cathepsin K (CPK) and nuclear factor kappa B (NF-κB). The extracellular signal-regulated kinase (ERK),phosphorylation of ERK (P-ERK) and NF-κB production were tested by Western blotting. The effect of AM630 on RAW264.7 viability was determined using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide (MTT) assay.Results AM630 did not affect the viability of RAW264.7. However, this CB2 selective antagonist markedly inhibited osteoclast formation and the inhibition rate was dose-dependent. The dose of >100 nmol/L could reduce TRAP positive cells to the levels that were significantly lower than the control. AM630 suppressed the expression of genes associated with osteoclast differentiation and activation, such as RANK and CPK. An analysis of a signaling pathway showed that AM630 inhibited the RANKL-induced activation of ERK, but not NF-κB.Conclusion AM630 could inhibit the osteoclastogenesis from RAW264.7 induced with RANKL.

  14. Vitamin D modulates tissue factor and protease-activated receptor 2 expression in vascular smooth muscle cells.

    Science.gov (United States)

    Martinez-Moreno, Julio M; Herencia, Carmen; Montes de Oca, Addy; Muñoz-Castañeda, Juan R; Rodríguez-Ortiz, M Encarnación; Díaz-Tocados, Juan M; Peralbo-Santaella, Esther; Camargo, Antonio; Canalejo, Antonio; Rodriguez, Mariano; Velasco-Gimena, Francisco; Almaden, Yolanda

    2016-03-01

    Clinical and epidemiologic studies reveal an association between vitamin D deficiency and increased risk of cardiovascular disease. Because vascular smooth muscle cell (VSMC)-derived tissue factor (TF) is suggested to be critical for arterial thrombosis, we investigated whether the vitamin D molecules calcitriol and paricalcitol could reduce the expression of TF induced by the proinflammatory cytokine TNF-α in human aortic VSMCs. We found that, compared with controls, incubation with TNF-α increased TF expression and procoagulant activity in a NF-κB-dependent manner, as deduced from the increased nuclear translocation of nuclear factor κ-light-chain-enhancer of activated B cells protein 65 (p65-NF-κB) and direct interaction of NF-κB to the TF promoter. This was accompanied by the up-regulation of TF signaling mediator protease-activated receptor 2 (PAR-2) expression and by the down-regulation of vitamin D receptor expression in a miR-346-dependent way. However, addition of calcitriol or paricalcitol blunted the TNF-α-induced TF expression and activity (2.01 ± 0.24 and 1.32 ± 0.14 vs. 3.02 ± 0.39 pmol/mg protein, P < 0.05), which was associated with down-regulation of NF-κB signaling and PAR-2 expression, as well as with restored levels of vitamin D receptor and enhanced expression of TF pathway inhibitor. Our data suggest that inflammation promotes a prothrombotic state through the up-regulation of TF function in VSMCs and that the beneficial cardiovascular effects of vitamin D may be partially due to decreases in TF expression and its activity in VSMCs.

  15. Markers of angiogenesis and epidermal growth factor receptor signalling in patients with pancreatic and gastroesophageal junction cancer.

    Science.gov (United States)

    Rohrberg, Kristoffer Staal; Skov, Birgit Guldhammer; Lassen, Ulrik; Christensen, Ib Jarle; Høyer-Hansen, Gunilla; Buysschaert, Ian; Pappot, Helle

    2010-01-01

    The epidermal growth factor receptor (EGFR) and angiogenesis are well established targets in anti-cancer therapy. Several targeted anti-cancer therapies are in clinical trials in pancreatic and gastroesophageal (GEJ) cancer. However, many patients do not respond to these targeted therapies and there is therefore an increasing need for biomarkers for selection of patients to these therapies. We investigated the expression of EGFR, vascular endothelial growth factor A (VEGF-A), and VEGF receptor 2 (VEGFR-2) in tumour tissue by immunohistochemistry, and soluble EGFR (sEGFR), soluble VEGFR-2 (sVEGFR-2), basic fibroblast growth factor (bFGF), placental growth factor (PlGF), plasminogen activator inhibitor 1 (PAI-1), and different forms of the urokinase plasminogen activator receptor (uPAR): uPAR (I), uPAR (I-III), and uPAR (I-III)+(II-III) in plasma by quantitative immunoassays in 14 patients with pancreatic and GEJ cancer. We found expression in tumour tissue and the plasma levels to be similar to those found in patients with other tumour types. No correlation was found between the blood levels of soluble receptors and the corresponding tumour tissue levels. We conclude that these markers are present in pancreatic and GEJ cancer patients, and could be investigated further as predictive biomarkers in such patients treated with EGFR or angiogenesis targeted therapies.

  16. Polymorphism in the serotonin receptor 2a (HTR2A gene as possible predisposal factor for aggressive traits.

    Directory of Open Access Journals (Sweden)

    Zsofia Banlaki

    Full Text Available Aggressive manifestations and their consequences are a major issue of mankind, highlighting the need for understanding the contributory factors. Still, aggression-related genetic analyses have so far mainly been conducted on small population subsets such as individuals suffering from a certain psychiatric disorder or a narrow-range age cohort, but no data on the general population is yet available. In the present study, our aim was to identify polymorphisms in genes affecting neurobiological processes that might explain some of the inter-individual variation between aggression levels in the non-clinical Caucasian adult population. 55 single nucleotide polymorphisms (SNP were simultaneously determined in 887 subjects who also filled out the self-report Buss-Perry Aggression Questionnaire (BPAQ. Single marker association analyses between genotypes and aggression scores indicated a significant role of rs7322347 located in the HTR2A gene encoding serotonin receptor 2a following Bonferroni correction for multiple testing (p = 0.0007 both for males and females. Taking the four BPAQ subscales individually, scores for Hostility, Anger and Physical Aggression showed significant association with rs7322347 T allele in themselves, while no association was found with Verbal Aggression. Of the subscales, relationship with rs7322347 was strongest in the case of Hostility, where statistical significance virtually equaled that observed with the whole BPAQ. In conclusion, this is the first study to our knowledge analyzing SNPs in a wide variety of genes in terms of aggression in a large sample-size non-clinical adult population, also describing a novel candidate polymorphism as predisposal to aggressive traits.

  17. Association of the Met-196-Arg variation of human tumor necrosis factor receptor 2 (TNFR2) with paranoid schizophrenia.

    Science.gov (United States)

    Thabet, Sihem; Ben Nejma, Mouna; Zaafrane, Ferid; Gaha, Lotfi; Ben Salem, Kamel; Romdhane, Abdelaziz; Nour, Mohamed; Jrad, Besma Bel Hadj

    2011-03-01

    Research has provided strong evidence for oligodendrocyte and myelin-related genes dysfunction in schizophrenia. Several studies have suggested abnormalities in the expression of myelin-related genes including tumor necrosis factor receptor 2 (TNFR2) involved in the neurodegeneration and remyelination. In order to further assess the role of TNFR2 in schizophrenia, we examined a functional bi-allelic polymorphism associated with an impaired NF-KB signaling and cell survival. In the present case/control study, 220 patients with schizophrenia and 176 healthy controls were genotyped by RFLP-PCR for the T/G polymorphism at the position 676 in exon 6 of the TNFR2 gene. We found a trend towards over-representation of TNFR2 676G in the patients compared to the controls (p=0.19 and 0.09 respectively). Interestingly, when we evaluated the association between this genetic polymorphism and the clinical variables of schizophrenia, our findings indicated that the frequencies of the G/G genotype and the G allele were significantly higher in paranoid (p=0.014 and p=0.012 respectively) and adult-onset paranoid (p=0.004 and p=0.004 respectively) schizophrenia patient group compared to the controls. The potential association was confirmed by a logistic regression model only for development of the paranoid form of schizophrenia (p=0.022) indicating a substantially increased risk for paranoid schizophrenia with inheritance of the TNFR2(G) allele. In conclusion, this polymorphism in TNFR2 or a gene in proximity seems to be associated specifically with paranoid schizophrenia, at least in the Tunisian population. A replication of our findings in other and larger populations could be of particular importance to establish TNFR2 as one of the susceptibility genes of paranoid schizophrenia.

  18. Comparative analysis of evolutionarily conserved motifs of epidermal growth factor receptor 2 (HER2 predicts novel potential therapeutic epitopes.

    Directory of Open Access Journals (Sweden)

    Xiaohong Deng

    Full Text Available Overexpression of human epidermal growth factor receptor 2 (HER2 is associated with tumor aggressiveness and poor prognosis in breast cancer. With the availability of therapeutic antibodies against HER2, great strides have been made in the clinical management of HER2 overexpressing breast cancer. However, de novo and acquired resistance to these antibodies presents a serious limitation to successful HER2 targeting treatment. The identification of novel epitopes of HER2 that can be used for functional/region-specific blockade could represent a central step in the development of new clinically relevant anti-HER2 antibodies. In the present study, we present a novel computational approach as an auxiliary tool for identification of novel HER2 epitopes. We hypothesized that the structurally and linearly evolutionarily conserved motifs of the extracellular domain of HER2 (ECD HER2 contain potential druggable epitopes/targets. We employed the PROSITE Scan to detect structurally conserved motifs and PRINTS to search for linearly conserved motifs of ECD HER2. We found that the epitopes recognized by trastuzumab and pertuzumab are located in the predicted conserved motifs of ECD HER2, supporting our initial hypothesis. Considering that structurally and linearly conserved motifs can provide functional specific configurations, we propose that by comparing the two types of conserved motifs, additional druggable epitopes/targets in the ECD HER2 protein can be identified, which can be further modified for potential therapeutic application. Thus, this novel computational process for predicting or searching for potential epitopes or key target sites may contribute to epitope-based vaccine and function-selected drug design, especially when x-ray crystal structure protein data is not available.

  19. Pertuzumab for the treatment of patients with human epidermal growth factor receptor 2-positive breast cancer in Japan.

    Science.gov (United States)

    Osako, Tomofumi; Nishimura, Reiki; Nishiyama, Yasuyuki; Fujisue, Mamiko

    2015-11-01

    Pertuzumab, a novel anti-human epidermal growth factor receptor 2 (HER2) agent, is effective for metastatic HER2-positive breast cancer when used in combination with taxane and trastuzumab. The aim of the present study was to describe the use of pertuzumab in Japan. A phase I clinical trial of pertuzumab for HER2-positive metastatic breast cancer was first conducted in the United States in 2001 (study ID no. TOC2297g) and for HER2-positive solid cancers in Japan in 2004 (study ID no. JO17076). However, Japanese patients were not enrolled in a global phase II trial for metastatic breast cancer (study ID no. BO17929) and no phase II trial of pertuzumab for Japanese patients has yet been conducted. A phase III trial on pertuzumab for metastatic breast cancer (CLEOPATRA study), which included 53 Japanese patients, revealed that pertuzumab significantly prolonged progression-free and overall survival. However, the superiority of the pertuzumab group was not verified in the subgroup analysis of Japanese patients, which was not a preplanned analysis. Therefore, a postmarketing clinical trial for Japanese patients with HER2-positive metastatic breast cancer (COMACHI study) was initiated in November, 2013, to investigate the clinical effectiveness of pertuzumab in Japanese patients. As of December, 2014, global trials on pertuzumab in the metastatic and adjuvant settings are currently ongoing. These trials included Japanese patients with HER2-positive breast cancer. Pertuzumab was approved in Japan in August, 2013 due to the positive findings of the CLEOPATRA study. Unlike the United States and Europe, the Japanes Pharmaceutical and Medical Devices Agency approved the administration of pertuzumab as second- or later-line treatment for HER2-positive metastatic breast cancer, as well as first-line treatment. Furthermore, pertuzumab may be used in combination with other chemotherapeutic agents, with the exception of docetaxel. The approval of the expanded use of pertuzumab is

  20. Dioscin inhibits colon tumor growth and tumor angiogenesis through regulating VEGFR2 and AKT/MAPK signaling pathways

    Energy Technology Data Exchange (ETDEWEB)

    Tong, Qingyi [Regenerative Medicine Research Center, State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, Chengdu, Sichuan 610041 (China); Qing, Yong, E-mail: qingyongxy@yahoo.co.jp [Department of Pharmacology, West China School of Pharmacy, Sichuan University, Chengdu, Sichuan 610041 (China); Wu, Yang [State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, Chengdu, Sichuan 610041 (China); Hu, Xiaojuan; Jiang, Lei [Department of Pharmacology, West China School of Pharmacy, Sichuan University, Chengdu, Sichuan 610041 (China); Wu, Xiaohua, E-mail: wuxh@scu.edu.cn [Regenerative Medicine Research Center, State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, Chengdu, Sichuan 610041 (China)

    2014-12-01

    Dioscin has shown cytotoxicity against cancer cells, but its in vivo effects and the mechanisms have not elucidated yet. The purpose of the current study was to assess the antitumor effects and the molecular mechanisms of dioscin. We showed that dioscin could inhibit tumor growth in vivo and has no toxicity at the test condition. The growth suppression was accompanied by obvious blood vessel decrease within solid tumors. We also found dioscin treatment inhibited the proliferation of cancer and endothelial cell lines, and most sensitive to primary cultured human umbilical vein endothelial cells (HUVECs). What's more, analysis of HUVECs migration, invasion, and tube formation exhibited that dioscin has significantly inhibitive effects to these actions. Further analysis of blood vessel formation in the matrigel plugs indicated that dioscin could inhibit VEGF-induced blood vessel formation in vivo. We also identified that dioscin could suppress the downstream protein kinases of VEGFR2, including Src, FAK, AKT and Erk1/2, accompanied by the increase of phosphorylated P38MAPK. The results potently suggest that dioscin may be a potential anticancer drug, which efficiently inhibits angiogenesis induced by VEGFR2 signaling pathway as well as AKT/MAPK pathways. - Highlights: • Dioscin inhibits tumor growth in vivo and does not exhibit any toxicity. • Dioscin inhibits angiogenesis within solid tumors. • Dioscin inhibits the proliferation, migration, invasion, and tube formation of HUVECs. • Dioscin inhibits VEGF–induced blood vessel formation in vivo. • Dioscin inhibits VEGFR2 signaling pathway as well as AKT/MAPK pathway.

  1. 以VEGF及VEGFR2为靶位的抗肿瘤血管生成主动免疫治疗的研究进展%Research Progress of Active Immunotherapies against Tumor Angiogenisis Targeting on VEGF and VEGFR2

    Institute of Scientific and Technical Information of China (English)

    王伟; 殷小涛; 田仁礼; 阎瑾琦; 高江平; 于继云

    2013-01-01

    Tumor cells stimulate angiogenesis to meet increasing nutrient and oxygen demands. Therefore, the dependence of growing tumors on new blood vessel formation has made anti-angiogenesis become one of the most appealing strategy in cancer research and therapeutics of clinical oncology. Among all of the factors stimulating angiogenesis, vascular endothelial growth factor (VEGF) and its receptor VEGFR2 (also called fetal liver kinse-1 [Flk-1] in mice, kinase-containing domain receptor [KDR] in humans) are critically important to the angiogenesis associated with tumor growth, metastasis and relapse. In addition, active anti-tumor immunotherapy has provided a novel strategy through interrupting tumor-mediated immune escape and suppression. By combining the two strategies, active anti-angiogenic immunotherapy might offer the possibility to more robustly inhibit tumor angiogenesis. This combination application of immunotherapy and anti-angiogenic treatment might represent a promising avenue for future research. This review summarized latest researches of active immunotherapy targeting tumor angiogenesis through interrupting the signal passway of VEGF/VEGFR2. This paper discussed three different types of vaccines utilized as anti-cancer therapeutics-cell vaccines, protein/peptide vaccines and gene/DNA vaccines-with a specific focus on angiogenesis suppression. And future research directions for this field are also outlined.%肿瘤细胞通过刺激新生血管生成来满足对营养及供氧的不断增长的需求,因此,肿瘤组织生长对于新生血管形成的依赖性使得抗血肿瘤管生成已经成为肿瘤学基础研究与临床治疗领域中最吸引人的策略之一.在众多的促血管生成因子中,血管内皮生长因子(VEGF)及其受体VEGFR2(鼠和人中也分别称为Flk-1和KDR)对于与肿瘤生长、转移及复发相关的血管生成是至关重要的.此外,通过打破肿瘤组织自身介导的免疫耐受与逃避,主动免疫治疗已

  2. Naringin promotes fracture healing through stimulation of angiogenesis by regulating the VEGF/VEGFR-2 signaling pathway in osteoporotic rats.

    Science.gov (United States)

    Song, Nan; Zhao, Zhihu; Ma, Xinlong; Sun, Xiaolei; Ma, Jianxiong; Li, Fengbo; Sun, Lei; Lv, Jianwei

    2017-01-05

    Postmenopausal osteoporosis is characterized by a reduction in the number of sinusoidal and arterial capillaries in the bone marrow and reduced bone perfusion. Thus, osteogenesis and angiogenesis are coupled in the process of osteoporosis formation and fracture healing. Naringin is the main ingredient of the root Rhizoma Drynariae, a traditional Chinese medicine, and it has potential effects on promoting fracture healing. However, whether naringin stimulates angiogenesis in the process of bone healing is unclear. Here, we show that naringin promotes fracture healing through stimulating angiogenesis by regulating the VEGF/VEGFR-2 signaling pathway in osteoporotic rats.

  3. Bystander killing effect of DS-8201a, a novel anti-human epidermal growth factor receptor 2 antibody-drug conjugate, in tumors with human epidermal growth factor receptor 2 heterogeneity.

    Science.gov (United States)

    Ogitani, Yusuke; Hagihara, Katsunobu; Oitate, Masataka; Naito, Hiroyuki; Agatsuma, Toshinori

    2016-07-01

    Antibody-drug conjugates deliver anticancer agents selectively and efficiently to tumor tissue and have significant antitumor efficacy with a wide therapeutic window. DS-8201a is a human epidermal growth factor receptor 2 (HER2)-targeting antibody-drug conjugate prepared using a novel linker-payload system with a potent topoisomerase I inhibitor, exatecan derivative (DX-8951 derivative, DXd). It was effective against trastuzumab emtansine (T-DM1)-insensitive patient-derived xenograft models with both high and low HER2 expression. In this study, the bystander killing effect of DS-8201a was evaluated and compared with that of T-DM1. We confirmed that the payload of DS-8201a, DXd (1), was highly membrane-permeable whereas that of T-DM1, Lys-SMCC-DM1, had a low level of permeability. Under a coculture condition of HER2-positive KPL-4 cells and negative MDA-MB-468 cells in vitro, DS-8201a killed both cells, whereas T-DM1 and an antibody-drug conjugate with a low permeable payload, anti-HER2-DXd (2), did not. In vivo evaluation was carried out using mice inoculated with a mixture of HER2-positive NCI-N87 cells and HER2-negative MDA-MB-468-Luc cells by using an in vivo imaging system. In vivo, DS-8201a reduced the luciferase signal of the mice, indicating suppression of the MDA-MB-468-Luc population; however, T-DM1 and anti-HER2-DXd (2) did not. Furthermore, it was confirmed that DS-8201a was not effective against MDA-MB-468-Luc tumors inoculated at the opposite side of the NCI-N87 tumor, suggesting that the bystander killing effect of DS-8201a is observed only in cells neighboring HER2-positive cells, indicating low concern in terms of systemic toxicity. These results indicated that DS-8201a has a potent bystander effect due to a highly membrane-permeable payload and is beneficial in treating tumors with HER2 heterogeneity that are unresponsive to T-DM1. © 2016 The Authors. Cancer Science published by John Wiley & Sons Australia, Ltd on behalf of Japanese Cancer

  4. Fragment-Based Discovery of a Dual pan-RET/VEGFR2 Kinase Inhibitor Optimized for Single-Agent Polypharmacology.

    Science.gov (United States)

    Frett, Brendan; Carlomagno, Francesca; Moccia, Maria Luisa; Brescia, Annalisa; Federico, Giorgia; De Falco, Valentina; Admire, Brittany; Chen, Zhongzhu; Qi, Wenqing; Santoro, Massimo; Li, Hong-yu

    2015-07-20

    Oncogenic conversion of the RET (rearranged during transfection) tyrosine kinase is associated with several cancers. A fragment-based chemical screen led to the identification of a novel RET inhibitor, Pz-1. Modeling and kinetic analysis identified Pz-1 as a type II tyrosine kinase inhibitor that is able to bind the "DFG-out" conformation of the kinase. Importantly, from a single-agent polypharmacology standpoint, Pz-1 was shown to be active on VEGFR2, which can block the blood supply required for RET-stimulated growth. In cell-based assays, 1.0 nM of Pz-1 strongly inhibited phosphorylation of all tested RET oncoproteins. At 1.0 mg kg(-1)  day(-1) per os, Pz-1 abrogated the formation of tumors induced by RET-mutant fibroblasts and blocked the phosphorylation of both RET and VEGFR2 in tumor tissue. Pz-1 featured no detectable toxicity at concentrations of up to 100.0 mg kg(-1), which indicates a large therapeutic window. This study validates the effectiveness and usefulness of a medicinal chemistry/polypharmacology approach to obtain an inhibitor capable of targeting multiple oncogenic pathways.

  5. Pertuzumab for the treatment of patients with human epidermal growth factor receptor 2-positive breast cancer in Japan

    Science.gov (United States)

    OSAKO, TOMOFUMI; NISHIMURA, REIKI; NISHIYAMA, YASUYUKI; FUJISUE, MAMIKO

    2015-01-01

    Pertuzumab, a novel anti-human epidermal growth factor receptor 2 (HER2) agent, is effective for metastatic HER2-positive breast cancer when used in combination with taxane and trastuzumab. The aim of the present study was to describe the use of pertuzumab in Japan. A phase I clinical trial of pertuzumab for HER2-positive metastatic breast cancer was first conducted in the United States in 2001 (study ID no. TOC2297g) and for HER2-positive solid cancers in Japan in 2004 (study ID no. JO17076). However, Japanese patients were not enrolled in a global phase II trial for metastatic breast cancer (study ID no. BO17929) and no phase II trial of pertuzumab for Japanese patients has yet been conducted. A phase III trial on pertuzumab for metastatic breast cancer (CLEOPATRA study), which included 53 Japanese patients, revealed that pertuzumab significantly prolonged progression-free and overall survival. However, the superiority of the pertuzumab group was not verified in the subgroup analysis of Japanese patients, which was not a preplanned analysis. Therefore, a postmarketing clinical trial for Japanese patients with HER2-positive metastatic breast cancer (COMACHI study) was initiated in November, 2013, to investigate the clinical effectiveness of pertuzumab in Japanese patients. As of December, 2014, global trials on pertuzumab in the metastatic and adjuvant settings are currently ongoing. These trials included Japanese patients with HER2-positive breast cancer. Pertuzumab was approved in Japan in August, 2013 due to the positive findings of the CLEOPATRA study. Unlike the United States and Europe, the Japanes Pharmaceutical and Medical Devices Agency approved the administration of pertuzumab as second- or later-line treatment for HER2-positive metastatic breast cancer, as well as first-line treatment. Furthermore, pertuzumab may be used in combination with other chemotherapeutic agents, with the exception of docetaxel. The approval of the expanded use of pertuzumab is

  6. Human epidermal growth factor receptor 2-positive breast cancer: which cytotoxic agent best complements trastuzumab's efficacy in vitro?

    Directory of Open Access Journals (Sweden)

    Hurrell T

    2013-06-01

    Full Text Available Tracey Hurrell, Kim OuthoffDepartment of Pharmacology, University of Pretoria, Pretoria, South AfricaIntroduction: Despite trastuzumab having enhanced selectivity for human epidermal growth factor receptor 2 (HER-2 overexpressing breast cancer cells, treatment is hampered by interindividual variation and tumors with high mitogenic potential. The lack of significant clinical benefit in certain patient cohorts suggests that HER-2 expression is ineffective as a sole prognostic indicator of response to therapy. Therefore, optimizing the clinical role of trastuzumab in drug combinations remains critical for clinical success.Aim: To investigate the effects of trastuzumab in combination with either doxorubicin or geldanamycin on in vitro cell viability, cell cycling, apoptosis and relative HER-2 expression in HER-2-positive (SK-BR-3 and estrogen receptor-positive (MCF-7 breast adenocarcinoma models.Results: HER-2-rich SK-BR-3 cells demonstrated a greater sensitivity to the effects of doxorubicin than MCF-7 cells. Concurrent trastuzumab exposure resulted in a further reduction in cell viability. This decreased cell viability induced by doxorubicin was associated with activation of executioner caspases as well as with alterations in cell-cycle kinetics, primarily promoting S-phase accumulation. Doxorubicin had no effect on surface HER-2 density expression. Geldanamycin reduced cell viability significantly greater in SK-BR-3 than MCF-7 cells, and was associated with G2 cell-cycle accumulation. The addition of trastuzumab did not augment these effects. Geldanamycin promoted substantial reductions in relative surface HER-2 density in SK-BR-3 cells.Conclusion: The in vitro data supported the rationale for using doxorubicin in trastuzumab-based therapies. Therefore, despite the incidence of cardiotoxicity, doxorubicin could retain a fundamental role in treating HER-2-positive breast cancer. While geldanamycin is a potent cytotoxic agent, its concurrent use

  7. Vascular endothelial growth factor signaling is necessary for expansion of medullary microvessels during postnatal kidney development

    DEFF Research Database (Denmark)

    Robdrup Tinning, Anne; Jensen, Boye L; Johnsen, Iben

    2016-01-01

    . In human fetal kidney tissue, immature vascular bundles appeared early in the third trimester (GA27-28) and expanded in size until term. Rat pups treated with the VEGF receptor-2 (VEGFR2) inhibitor vandetanib (100 mg·kg(-1)·day(-1)) from P7 to P12 or P10 to P16 displayed growth retardation and proteinuria......Postnatal inhibition or deletion of angiotensin II (ANG II) AT1 receptors impairs renal medullary mircrovascular development through a mechanism that may include vascular endothelial growth factor (VEGF). The present study was designed to test if VEGF/VEGF receptor signaling is necessary...... mechanism....

  8. Inhibition of VEGFR2 Activation and Its Downstream Signaling to ERK1/2 and Calcium by Thrombospondin-1 (TSP1): In silico Investigation

    Science.gov (United States)

    Bazzazi, Hojjat; Isenberg, Jeffery S.; Popel, Aleksander S.

    2017-01-01

    VEGF signaling through VEGFR2 is a central regulator of the angiogenic response. Inhibition of VEGF signaling by the stress-induced matricellular protein TSP1 plays a role in modulating the angiogenic response to VEGF in both health and disease. TSP1 binding to CD47 inhibits VEGFR2 activation. The full implications of this inhibitory interaction are unknown. We developed a detailed rule-based computational model to inquire if TSP1-CD47 signaling through VEGF had downstream effects upon ERK1/2 and calcium. Our Simulations suggest that enhanced degradation of VEGFR2 initiated by the binding of TSP1 to CD47 is sufficient to explain the inhibition of VEGFR2 phosphorylation, calcium elevation, and ERK1/2 activation downstream of VEGF. A complementary mechanism involving the recruitment of phosphatases to the VEGFR2 complex with consequent increase in the rate of receptor dephosphorylation may augment the inhibition of the VEGF signal. The model was then utilized to simulate the effect of inhibiting external TSP1 or the depletion of CD47 as potential therapeutic strategies in restoring VEGF signaling. Results suggest that depleting CD47 is a more efficient strategy in inhibiting the effects of TSP1/CD47 on VEGF signaling. Our results highlight the utility of in silico investigations in elucidating and clarifying molecular mechanisms at the intersection of TSP1 and VEGF biology and in differentiating between competing pro-angiogenic therapeutic strategies relevant to peripheral arterial disease (PAD) and wound healing. PMID:28220078

  9. EGFR、PDGFRA和VEGFR2在结肠癌中的表达及变异分析%Molecular characterization of EGFR, PDGFRA and VEGFR2 in colon cancer

    Institute of Scientific and Technical Information of China (English)

    邓子龙; 刘蔚东

    2016-01-01

    Objective To investigate EGFR, PDGFRA and VEGFR2 RTKs overexpression and activating gene mu-tations in a cohort of 30 colon cancer patients sample. Methods EGFR, PDGFRA and VEGFR2 immunohistochem-istry was performed in all samples, followed by DNA isolation from the gross macroscopically dissection of the neo-plastic area. Screening for EGFR (exons18-21) and PDGFRA (exons12, 14 and 18) mutations was done by PCR-sin-gle-strand conformational polymorphism (PCR-SSCP). Results Despite the presence of EGFR immunohistochemical positive reactions in 43 % (13/30) of the samples, no EGFR activating mutations in the hotspot region (exons18-21) were identified. A silent base substitution (CAG > CAA) in EGFR exon 20 at codon 787 (Q787Q) was found in 17 cases (56 %). All PDGFRA immunohistochemical reactions were positive and consistently observed in the stromal component, staining fibroblasts and endothelial cells, as well as in the cytoplasm of malignant cells. No activating PDGFRA mutations were found, yet, several silent mutations were observed, such as a base substitution in exon 12 (CCA > CCG) at codon 567 (P567P) in 9 cases and in exon18 (GTC > GTT) at codon 824 (V824V) in 4 cases. We also observed the presence of base substitutions in intron 14 (IVS14 +3G >A and IVS14 +49G >A) in two differ-ent cases, and in intron 18 (IVS18-50 insA) in 4 cases. VEGFR2 positivity was observed in 22 of 30 cases (73.3%),and was significantly associated with lack of metastasis ( =0.038). Conclusions Despite the absence of EGFR and PDGFRA activating mutations, the presence of overexpression of these three important therapeutic targets in a subset of cases may be important in predicting the sensitivity of colon cancer to specific anti-RTKs drugs.%目的:探讨受体酪氨酸激酶表皮生长因子受体(EGFR),血小板源性生长因子受体α多肽(PDGFRA)和血管内皮细胞生长因子受体2(VEGFR2)在30例结肠癌中的过表达及基因突变情况。方法收集该

  10. Phase III randomized study comparing docetaxel plus trastuzumab with vinorelbine plus trastuzumab as first-line therapy of metastatic or locally advanced human epidermal growth factor receptor 2-positive breast cancer: the HERNATA study

    DEFF Research Database (Denmark)

    Andersson, Michael; Lidbrink, Elisabeth; Bjerre, Karsten;

    2011-01-01

    To evaluate docetaxel or vinorelbine, both with trastuzumab, as first-line therapy of human epidermal growth factor receptor 2-positive advanced breast cancer.......To evaluate docetaxel or vinorelbine, both with trastuzumab, as first-line therapy of human epidermal growth factor receptor 2-positive advanced breast cancer....

  11. Changes of expression of estrogen and progestrone receptors, human epithelial growth factor receptor 2 and Ki-67 after neoadjuvant chemotherapy in the treatment of breast cancer.

    Science.gov (United States)

    Li, M L; Dong, Y; Luan, S L; Zhao, Z H; Ning, F L

    2016-01-01

    Recent studies suggest that the development and prognosis of breast cancer is in close correlation to molecular subtype of breast cancer. Neoadjuvant chemotherapy has been extensively applied in the treatment of local breast cancer in advanced stage. In order to verify the correlation between expression changes of estrogen receptor, progestrone receptor, human epithelial growth factor receptor 2 and Ki-67 after neoadjuvant chemotherapy and neoadjuvant chemotherapy, we studied 120 patients with stage IIAIIIC breast cancer who underwent neoadjuvant chemotherapy in Binzhou Medical University Hospital, Shandong, China from February 2011 to February 2015. Clinical characteristics were retrospectively analyzed. The expression of estrogen receptor, progesterone receptor, human epithelial growth factor receptor 2 and Ki-67 of patients were detected using the immunohistochemical method before and after neoadjuvant chemotherapy. The results suggest that the overall remission rate of neoadjuvant chemotherapy was 76.7% (92/120) of which 16.7% (20/120) of cases had complete remission, 60% (72/120) had partial remission and 23.3% (28/120) were stable. There were no cases of progressive disease. The property of estrogen receptor and the expression of Ki-67 of primary tumor were correlated to the remission rate of neoadjuvant chemotherapy (P less than 0.05). The expression of Ki-67 had a significant decline after neoadjuvant chemotherapy, and the difference had statistical significance (P less than 0.05). The difference in expression of estrogen receptor, progesterone receptor and human epithelial growth factor receptor 2 before and after neoadjuvant chemotherapy had statistical significance (P > 0.05). Hence, it can be concluded that breast cancer patients with negative estrogen receptor expression and high Ki-67 expression before neoadjuvant chemotherapy can achieve better curative effects. Neoadjuvant chemotherapy cannot change the expression states of estrogen receptor

  12. Hypoxia-induced reduction of sVEGFR-2 levels in human colonic microvascular endothelial cells in vitro: Comparative study with HUVEC.

    Science.gov (United States)

    Jayasinghe, Caren; Simiantonaki, Nektaria; Michel-Schmidt, Romi; Kirkpatrick, Charles James

    2009-01-01

    The functionality of large-vessel endothelial cells, such as human umbilical vein endothelial cells (HUVEC), may differ significantly from that in the microvasculature. We established a method for the isolation of human colonic microvascular endothelial cells (HCMEC). Since colonic diseases are often accompanied by hypoxia we examined its effects on HCMEC of five individuals in comparison with HUVEC, with respect to the secretion of the soluble form of the two important vascular endothelial growth factor (VEGF) receptors, VEGFR-1 and 2. After dissociation by dispase/collagenase of mucosal and submucosal tissue obtained from normal adult colon, HCMEC were isolated using CD31-coated magnetic beads and cultivated as monolayers. Subsequent characterization studies demonstrated the endothelial phenotype, including VEGFR-1 and 2 mRNA and protein expression. sVEGFR expression analyses were performed using ELISA. Under hypoxic conditions significantly enhanced levels of sVEGFR-1 on HUVEC were observed (pHUVEC were variable, that is, either unchanged or up-regulated. The different secretion profiles of sVEGFR-1 and 2 between HUVEC and HCMEC under normoxia and hypoxia underline the importance of using a functionally adequate and relevant microvasculature for in vitro studies of colonic diseases. The homogeneously reduced sVEGFR-2 levels in hypoxic HCMEC provide evidence for a novel microvascular endothelium-specific biomarker in hypoxia-response processes.

  13. The Adnectin CT-322 is a novel VEGF receptor 2 inhibitor that decreases tumor burden in an orthotopic mouse model of pancreatic cancer

    Directory of Open Access Journals (Sweden)

    Miller Andrew F

    2008-11-01

    Full Text Available Abstract Background Pancreatic cancer continues to have a 5-year survival of less than 5%. Therefore, more effective therapies are necessary to improve prognosis in this disease. Angiogenesis is required for tumor growth, and subsequently, mediators of angiogenesis are attractive targets for therapy. Vascular endothelial growth factor (VEGF is a well-characterized mediator of tumor angiogenesis that functions primarily by binding and activating VEGF receptor 2 (VEGFR2. In this study, we evaluate the use of CT-322, a novel biologic (Adnectin. This small protein is based on a human fibronectin domain and has beneficial properties in that it is fully human, stable, and is produced in bacteria. CT-322 binds to and inhibits activation of VEGFR2. Methods The efficacy of CT-322 was evaluated in vivo using two orthotopic pancreatic tumor models. The first model was a human tumor xenograft where MiaPaCa-2 cells were injected into the tail of the pancreas of nude mice. The second model was a syngeneic tumor using Pan02 cells injected into pancreas of C57BL/6J mice. In both models, therapy was initiated once primary tumors were established. Mice bearing MiaPaCa-2 tumors were treated with vehicle or CT-322 alone. Gemcitabine alone or in combination with CT-322 was added to the treatment regimen of mice bearing Pan02 tumors. Therapy was given twice a week for six weeks, after which the animals were sacrificed and evaluated (grossly and histologically for primary and metastatic tumor burden. Primary tumors were also evaluated by immunohistochemistry for the level of apoptosis (TUNEL, microvessel density (MECA-32, and VEGF-activated blood vessels (Gv39M. Results Treatment with CT-322 was effective at preventing pancreatic tumor growth and metastasis in orthotopic xenograft and syngeneic models of pancreatic cancer. Additionally, CT-322 treatment increased apoptosis, reduced microvessel density and reduced the number of VEGF-activated blood vessels in tumors

  14. Evaluation of human epidermal growth factor receptor 2 (HER2) single nucleotide polymorphisms (SNPs) in normal and breast tumor tissues and their link with breast cancer prognostic factors.

    Science.gov (United States)

    Furrer, Daniela; Lemieux, Julie; Côté, Marc-André; Provencher, Louise; Laflamme, Christian; Barabé, Frédéric; Jacob, Simon; Michaud, Annick; Diorio, Caroline

    2016-12-01

    Amplification of the human epidermal growth factor receptor 2 (HER2) gene is associated with worse prognosis and decreased overall survival in breast cancer patients. The HER2 gene contains several polymorphisms; two of the best-characterized HER2 polymorphisms are Ile655Val and Ala1170Pro. The aim of this study was to evaluate the association between these two HER2 polymorphisms in normal breast and breast cancer tissues and known breast cancer prognostic factors in a retrospective cohort study of 73 women with non-metastatic HER2-positive breast cancer. HER2 polymorphisms were assessed in breast cancer tissue and normal breast tissue using TaqMan assay. Ala1170Pro polymorphism in normal breast tissue was associated with age at diagnosis (p = 0.007), tumor size (p = 0.004) and lymphovascular invasion (p = 0.06). Similar significant associations in cancer tissues were observed. No association between the Ile655Val polymorphism and prognostic factors were observed. However, we found significant differences in the distribution of Ile655Val (p = 0.03) and Ala1170Pro (p = 0.01) genotypes between normal breast and breast tumor tissues. This study demonstrates that only the Ala1170Pro polymorphism is associated with prognostic factors in HER2-positive breast cancer patients. Moreover, our results suggest that both HER2 polymorphisms could play a significant role in carcinogenesis in non-metastatic HER2-positive breast cancer women.

  15. Neuropilin-1 modulates vascular endothelial growth factor-induced poly(ADP-ribose)-polymerase leading to reduced cerebrovascular apoptosis.

    Science.gov (United States)

    Mey, Lilli; Hörmann, Mareike; Schleicher, Nadine; Reuter, Peter; Dönges, Simone; Kinscherf, Ralf; Gassmann, Max; Gerriets, Tibo; Al-Fakhri, Nadia

    2013-11-01

    Cerebral ischemia is encompassed by cerebrovascular apoptosis, yet the mechanisms behind apoptosis regulation are not fully understood. We previously demonstrated inhibition of endothelial apoptosis by vascular endothelial growth factor (VEGF) through upregulation of poly(ADP-ribose)-polymerase (PARP) expression. However, PARP overactivation through oxidative stress can lead to necrosis. This study tested the hypothesis that neuropilin-1 (NP-1), an alternative VEGF receptor, regulates the response to cerebral ischemia by modulating PARP expression and, in turn, apoptosis inhibition by VEGF. In endothelial cell culture, NP-1 colocalized with VEGF receptor-2 (VEGFR-2) and acted as its coreceptor. This significantly enhanced VEGF-induced PARP mRNA and protein expression demonstrated by receptor-specific inhibitors and VEGF-A isoforms. NP-1 augmented the inhibitory effect of VEGF/VEGFR-2 interaction on apoptosis induced by adhesion inhibition through the αV-integrin inhibitor cRGDfV. NP-1/VEGFR-2 signal transduction involved JNK and Akt. In rat models of permanent and temporary middle cerebral artery occlusion, the ischemic cerebral hemispheres displayed endothelial and neuronal apoptosis next to increased endothelial NP-1 and VEGFR-2 expression compared to non-ischemic cerebral hemispheres, sham-operated or untreated controls. Increased vascular superoxide dismutase-1 and catalase expression as well as decreased glycogen reserves indicated oxidative stress in the ischemic brain. Of note, protein levels of intact PARP remained stable despite pro-apoptotic conditions through increased PARP mRNA production during cerebral ischemia. In conclusion, NP-1 is upregulated in conditions of imminent cerebrovascular apoptosis to reinforce apoptosis inhibition and modulate VEGF-dependent PARP expression and activation. We propose that NP-1 is a key modulator of VEGF maintaining cerebrovascular integrity during ischemia. Modulating the function of NP-1 to target PARP could help to

  16. Elevated microRNA-126 is associated with high vascular endothelial growth factor receptor 2 expression levels and high microvessel density in colorectal cancer

    DEFF Research Database (Denmark)

    Hansen, Torben Frøstrup; Andersen, Claus Lindbjerg; Nielsen, Boye Schnack

    2011-01-01

    analysed by ELISA. Angiogenesis, visualised by the endothelial cell marker CD105 combined with caldesmon, was assessed by immunohistochemistry and the microvessel density (MVD) technique. In situ hybridisation was performed for miRNA-126. Tumours were classified as low or high miRNA‑126-expressing using...... the median as the cut-off. The median gene expression levels of VEGFR-2 were significantly lower in the tumours expressing low levels of miRNA-126, 0.30 (95% CI, 0.24‑0.36), compared to those expressing high levels of miRNA-126, 0.48 (95% CI, 0.28-0.60), p=0.02. A positive association was observed with VEGFR......-2 protein concentrations, p=0.06. The median MVD was significantly lower in the tumours expressing low levels of miRNA-126, 5.8 (95% CI, 5.33‑6.67), compared to those expressing high levels, 8.0 (95% CI, 6.33‑9.00), p

  17. Alterations in the human epidermal growth factor receptor 2-phosphatidylinositol 3-kinase-v-Akt pathway in gastric cancer

    Institute of Scientific and Technical Information of China (English)

    Yasutaka Sukawa; Hiroyuki Yamamoto; Katsuhiko Nosho; Hiroaki Kunimoto; Hiromu Suzuki; Yasushi Adachi; Mayumi Nakazawa

    2012-01-01

    AIM:To investigate human epidermal growth factor receptor 2 (HER2)-phosphatidylinositol 3-kinase (PI3K)-v-Akt murine thymoma viral oncogene homolog signaling pathway.METHODS:We analyzed 231 formalin-fixed,paraffinembedded gastric cancer tissue specimens from Japanese patients who had undergone surgical treatment.The patients' age,sex,tumor location,depth of invasion,pathological type,lymph node metastasis,and pathological stage were determined by a review of the medical records.Expression of HER2 was analyzed by immunohistochemistry (IHC) using the HercepTestTM kit.Standard criteria for HER2 positivity (0,1+,2+,and 3+) were used.Tumors that scored 3+ were considered HER2-positive.Expression of phospho Akt (pAkt)was also analyzed by IHC.Tumors were considered pAkt-positive when the percentage of positive tumor cells was 10% or more.PI3K,catalytic,alpha polypeptide (PIK3CA) mutations in exons 1,9 and 20 were analyzed by pyrosequencing.Epstein-Barr virus (EBV)infection was analyzed by in situ hybridization targeting EBV-encoded small RNA (EBER) with an EBER-RNA probe.Microsatellite instability (MSI) was analyzed by polymerase chain reaction using the mononucleotide markers BAT25 and BAT26.RESULTS:HER2 expression levels of 0,1+,2+ and 3+ were found in 167 (72%),32 (14%),12 (5%) and 20 (8.7%) samples,respectively.HER2 overexpression (IHC 3+) significantly correlated with intestinal histological type (15/20 vs 98/205,P =0.05).PIK3CA mutations were present in 20 cases (8.7%) and significantly correlated with MSI (10/20 vs 9/211,P < 0.01).The mutation frequency was high (21%) in T4 cancers and very low (6%) in T2 cancers.Mutations in exons 1,9 and 20 were detected in 5 (2%),9 (4%) and 7(3%) cases,respectively.Two new types of PIK3CA mutation,R88Q and R108H,were found in exon1.All PIK3CA mutations were heterozygous missense singlebase substitutions,the most common being H1047R (6/20,30%) in exon20.Eighteen cancers (8%) were EBV-positive and this

  18. Discovery of N-(2-phenyl-1H-benzo[d]imidazol-5-yl)quinolin-4-amine derivatives as novel VEGFR-2 kinase inhibitors.

    Science.gov (United States)

    Shi, Lei; Wu, Ting-Ting; Wang, Zhi; Xue, Jia-Yu; Xu, Yun-Gen

    2014-09-12

    Inhibition of the VEGF signaling pathway has become a valuable approach in the treatment of cancers. In this work, a series of N-(2-phenyl-1H-benzo[d]imidazol-5-yl)quinolin-4-amine derivatives were designed and identified as potent inhibitors of VEGFR-2 (KDR) kinase. These compounds with quinoline scaffold and benzimidazole moiety were synthesized and their biological activities against VEGFR-2 and two human cancer cell lines were evaluated. Among them, compound 7s exhibited the most potent inhibitory activity against VEGFR-2 with IC50 of 0.03 μM and it also showed the highest anticancer activity against the tested cancer cell lines with IC50 of 1.2 μM against MCF-7 and 13.3 μM against Hep-G2. Docking simulation supported the initial pharmacophoric hypothesis and suggested a common mode of interaction at the ATP-binding site of VEGFR-2, which demonstrates that compound 7s is a potential agent for cancer therapy deserving further researching. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  19. A development of chimeric VEGFR2 TK inhibitor based on two ligand conformers from PDB: 1Y6A complex--medicinal chemistry consequences of a TKs analysis.

    Science.gov (United States)

    Lintnerová, Lucia; García-Caballero, Melissa; Gregáň, Fridrich; Melicherčík, Milan; Quesada, Ana R; Dobiaš, Juraj; Lác, Ján; Sališová, Marta; Boháč, Andrej

    2014-01-24

    VEGFR2 is an important mediator of angiogenesis and influences fate of some cancer stem cells. Here we analysed all 34 structures of VEGFR2 TK available from PDB database. From them a complex PDB: 1Y6A has an exceptional AAZ ligand bound to TK in form of two conformers (U- and S-shaped). This observation inspired us to develop three chimeric bispyridyl VEGFR2 inhibitors by combining structural features of both AAZ conformers and/or their relative ligand AAX (PDB: 1Y6B). Our most interesting inhibitor 22SYM has an enzymatic VEGFR2 TK activity (IC50: 15.1 nM) comparable or better to the active compounds from clinical drugs Nexavar and Sutent. 22SYM inhibits growth, migration and tube formation of endothelial cells (EC) and selectively induces EC apoptosis. 22SYM also inhibits in vivo angiogenesis in Zebrafish embryo assay. Additionally to the above results, we proved here that tyrosine kinases in an inactive form possessing Type I inhibitors can adopt both a closed or an opened conformation of kinase A-loop independently on their DFG-out arrangement. We proposed here that an activity of certain Type I inhibitors (e.g. 22SYM-like) in complex with DFG-out TK can be negatively influenced by collisions with a dynamically moving TK A-loop.

  20. Genetic interaction of P2X7 receptor and VEGFR-2 polymorphisms identifies a favorable prognostic profile in prostate cancer patients.

    Science.gov (United States)

    Solini, Anna; Simeon, Vittorio; Derosa, Lisa; Orlandi, Paola; Rossi, Chiara; Fontana, Andrea; Galli, Luca; Di Desidero, Teresa; Fioravanti, Anna; Lucchesi, Sara; Coltelli, Luigi; Ginocchi, Laura; Allegrini, Giacomo; Danesi, Romano; Falcone, Alfredo; Bocci, Guido

    2015-10-01

    VEGFR-2 and P2X7 receptor (P2X7R) have been described to stimulate the angiogenesis and inflammatory processes of prostate cancer. The present study has been performed to investigate the genetic interactions among VEGFR-2 and P2X7R SNPs and their correlation with overall survival (OS) in a population of metastatic prostate cancer patients. Analyses were performed on germline DNA obtained from blood samples and SNPs were investigated by real-time PCR technique. The survival dimensionality reduction (SDR) methodology was applied to investigate the genetic interaction between SNPs. One hundred patients were enrolled. The SDR software provided two genetic interaction profiles consisting of the combination between specific VEGFR-2 (rs2071559, rs11133360) and P2X7R (rs3751143, rs208294) genotypes. The median OS was 126 months (95% CI, 115.94-152.96) and 65.65 months (95% CI, 52.95-76.53) for the favorable and the unfavorable genetic profile, respectively (p < 0.0001). The genetic statistical interaction between VEGFR-2 (rs2071559, rs11133360) and P2X7R (rs3751143, rs208294) genotypes may identify a population of prostate cancer patients with a better prognosis.

  1. Factors affecting disease-free survival in patients with human epidermal growth factor receptor 2-positive breast cancer who receive adjuvant trastuzumab

    Science.gov (United States)

    GÜNDÜZ, SEYDA; GÖKSU, SEMA SEZGIN; ARSLAN, DENIZ; TATLI, ALI MURAT; UYSAL, MÜKREMIN; GÜNDÜZ, UMUT RIZA; SEVINÇ, MERT MAHSUNI; COŞKUN, HASAN SENOL; BOZCUK, HAKAN; MUTLU, HASAN; SAVAS, BURHAN

    2015-01-01

    Breast cancer is the most frequently diagnosed cancer in women worldwide and the second cause of cancer-related mortality. A total of 20–30% of patients with early-stage breast cancer develop recurrence within the first 5 years following diagnosis. Trastuzumab significantly improves overall survival and disease-free survival (DFS) in women with human epidermal growth factor receptor 2 (HER2)-positive early and locally advanced breast cancer. This study aimed to determine the factors that affect DFS following adjuvant transtuzumab therapy. A total of 62 patients treated with trastuzumab for early and locally advanced breast cancer were included in our study. Data, including pathology, treatment and treatment outcome, rate of recurrence and laboratory tests, were retrospectively collected. There was no significant association between DFS and age, menopausal status, disease stage and hormone receptor status. The median follow-up was 48.4 months. The median DFS of patients treated with adjuvant trastuzumab was 64.1 months. In addition, the median DFS was 44.3 vs. 66.8 months in patients with platelet-lymphocyte ratio (PLR) ≤200 vs. >200, respectively (log-rank test; P=0.001), and 70 vs. 45 months in patients with eosinophil count ≤70 vs. >70×103/mm3 (log-rank test; P=0.001). Our data revealed the prognostic relevance of a decrease in the peripheral blood eosinophil count and PLR value following trastuzumab therapy in breast cancer. PLR and eosinophil count measurements are cost-effective, readily available worldwide, non-invasive and safe. Combined with other markers, such as patient age, tumor stage and tumor histology, may be effectively used for patients with breast cancer. PMID:26623060

  2. Genetic variants of fibroblast growth factor receptor 2 (FGFR2) are associated with breast cancer risk in Chinese women of the Han nationality.

    Science.gov (United States)

    Chen, Fan; Lu, Min; Lv, Min; Xue, Yun; Zhou, Jing; Hu, Feifei; Chen, Xin; Zhao, Zhanqin; Li, Yang; Wang, XingGuo

    2012-01-01

    Fibroblast growth factor receptor 2 (FGFR2), a recently described risk factor for breast cancer, plays important roles in cell growth, invasiveness, motility, and angiogenesis. In attempt to investigate whether FGFR2 polymorphisms are associated with a risk of breast cancer in Chinese women of the Han nationality, we genotyped single-nucleotide polymorphisms (SNPs) of seven FGFR2 sites (rs2981582, rs17102287, rs17542768, rs10510097, rs11200012, rs3750817, rs2981578) in 816 women including 388 breast cancer patients and 428 healthy controls via the polymerase chain reaction single-strand conformation polymorphism procedure as well as sequence detection. Our results suggest that the A allele and AA genotype of SNP rs2981578 appear to be protective factors associated with breast cancer, while the CT genotype of SNP rs3750817 is a putative risk factor.

  3. Expression of VEGF receptors VEFGR-1 and VEGFR-2, angiopoietin receptors Tie-1 and Tie-2 in chorionic villi tree during early pregnancy.

    Directory of Open Access Journals (Sweden)

    Ramazan Demir

    2010-02-01

    Full Text Available The aim of this study was to determine the expression of VEGF and its receptors in placentas from normal pregnancies between 22 days p.c. and 48 days p.c. of very early pregnancy. Placental tissues carried out from 19 pregnant women were examined. Immunohistochemical technique, electron microscopy were employed to evaluate the factors expression. In the new developing mesenchymal villi and immature intermediate villi VEGF and its receptors VEGFR-1 and VEGFR-2 immunoreactivity was detected in all the placental components, while in the stem villi and in the chorionic plate with large vessels only in some components. In the mesenchymal villi and immature intermediate villi VEGFR-1 and -2, and angiopoietin receptors Tie-1 and -2 immunoreactivity was dominantly observed in the heamangiogenic cells and cells cords, whereas the matured villi showed immunoreactivity only in other components. The ultrastructural findings were higher in respect to the all of the early pregnancy days. The placental samples from all of pregnancies, showed the VEGF and its receptors in optimal expression levels, whereas the angiopoietin receptors Tie-1 and -2 showed a higher expression levels in respect to other study factors. The receptors protein levels increased from the early days to the advanced days of gestation, but this alteration was not significant. The intensity of the immunolabeling for these proteins were not significant compared to to each other of gestatin days were examined. These findings demonstrated that a dysregulation of the placental expression of the VEGF and its receptors related to the different degrees of the gestational periods. Probably, this event may be related to complete vasculugenesis and angiogenesis in placental villi.

  4. Metabotropic glutamate receptor 2 and corticotrophin-releasing factor receptor-1 gene expression is differently regulated by BDNF in rat primary cortical neurons

    DEFF Research Database (Denmark)

    Jørgensen, Christinna V; Klein, Anders B; El-Sayed, Mona;

    2013-01-01

    Brain-derived neurotrophic factor (BDNF) is important for neuronal survival and plasticity. Incorporation of matured receptor proteins is an integral part of synapse formation. However, whether BDNF increases synthesis and integration of receptors in functional synapses directly is unclear. We...... are particularly interested in the regulation of the 5-hydroxytryptamine receptor 2A (5-HT2A R). This receptor form a functional complex with the metabotropic glutamate receptor 2 (mGluR2) and is recruited to the cell membrane by the corticotrophin-releasing factor receptor 1 (CRF-R1). The effect of BDNF on gene...... expression for all these receptors, as well as a number of immediate-early genes, was pharmacologically characterized in primary neurons from rat frontal cortex. BDNF increased CRF-R1 mRNA levels up to fivefold, whereas mGluR2 mRNA levels were proportionally downregulated. No effect on 5-HT2A R mRNA was seen...

  5. Procyanidin B2 3,3″-di-O-gallate inhibits endothelial cells growth and motility by targeting VEGFR2 and integrin signaling pathways.

    Science.gov (United States)

    Kumar, Rahul; Deep, Gagan; Wempe, Michael F; Agarwal, Rajesh; Agarwal, Chapla

    2015-01-01

    Targeting angiogenesis, one of the hallmarks of carcinogenesis, using non-toxic phytochemicals has emerged as a translational opportunity for angioprevention and to control advanced stages of malignancy. Herein, we investigated the inhibitory effects and associated mechanism/s of action of Procyanidin B2-3,3″-di- O-gallate (B2G2), a major component of grape seed extract, on human umbilical vein endothelial cells (HUVECs) and human prostate microvascular endothelial cells (HPMECs). Our results showed that B2G2 (10-40 μM) inhibits growth and induces death in both HUVECs and HPMECs. Additional studies revealed that B2G2 causes a G1 arrest in cell cycle progression of HUVECs by down-regulating cyclins (D1 and A), CDKs (Cdk2 and Cdc2) and Cdc25c phosphatase and up-regulating CDK inhibitors (p21 and p27) expression. B2G2 also induced strong apoptotic death in HUVECs through increasing p53, Bax and Smac/Diablo expression while decreasing Bcl-2 and survivin levels. Additionally, B2G2 inhibited the growth factors-induced capillary tube formation in HUVECs and HPMECs. Interestingly, conditioned media (CCM) from prostate cancer (PCA) cells (LNCaP and PC3) grown under normoxic (~21% O2) and hypoxic (1% O2) conditions significantly enhanced the tube formation in HUVECs, which was compromised in presence of conditioned media from B2G2-treated PCA cells. B2G2 also inhibited the motility and invasiveness of both HUVECs and HPMECs. Mechanistic studies showed that B2G2 targets VEGFR2/PI3K/Akt and integrin signaling molecules which are important for endothelial cells survival, proliferation, tube formation and motility. Overall, we report that B2G2 inhibits several attributes of angiogenesis in cell culture; therefore, it warrants further investigation for efficacy for angioprevention and cancer control.

  6. Novel angiogenesis inhibitory activity in cinnamon extract blocks VEGFR2 kinase and downstream signaling

    Science.gov (United States)

    VEGF is one of the most critical factors that induce angiogenesis, and has thus become an attractive target for anti-angiogenesis treatment. However, most of the current anti-VEGF agents that often cause side effects cannot be recommended for long term use. Identification of natural VEGF inhibitors...

  7. NGF promotes hemodynamic recovery in a rabbit hindlimb ischemic model through trkA- and VEGFR2-dependent pathways.

    Science.gov (United States)

    Karatzas, Andreas; Katsanos, Konstantinos; Lilis, Ioannis; Papadaki, Helen; Kitrou, Panagiotis; Lecht, Shimon; Marcinkiewicz, Cezary; Siablis, Dimitris; Lelkes, Peter I; Lazarovici, Philip; Tsopanoglou, Nikos E

    2013-09-01

    Nerve growth factor (NGF) has been reported to play an important role in physiological and pathological angiogenesis. Based on these observations, we hypothesized that NGF may induce the formation of functional blood vessels in a hindlimb ischemic rabbit model. Hindlimb ischemia was induced in 34 rabbits bilaterally by endovascular embolization of femoral arteries. On the 7th, 14th, and 20th postembolization days, NGF was injected intramuscularly, in 1 ischemic limb, and vehicle was injected in the contralateral control limb. On the 40th day, newly developed collateral vessels (diameter >500 μm) were quantified by transauricular intraarterial subtraction angiography. Perfusion analysis of an in vivo dynamic computed tomography study was performed to the limbs to investigate the hemodynamic recovery of the distal ischemic tissues. Functional estimation of limb perfusion showed a statistically significant increase of blood flow and blood volume for NGF. However, the increase of the collateral vessels was not detectable angiographically, providing evidence for the existence of a NGF-stimulated capillary angiogenic network but not increase of arteriogenesis. The combination of NGF with either tropomyosin-related kinase type A or vascular endothelial growth factor receptor 2 antagonists abolished the NGF-induced hemodynamic recovery. These findings provide new insights into understanding the involvement of NGF in vascular formation and its applications in therapeutic angiogenesis.

  8. New Coumarin Derivatives as Anti-Breast and Anti-Cervical Cancer Agents Targeting VEGFR-2 and p38α MAPK.

    Science.gov (United States)

    Batran, Rasha Z; Dawood, Dina H; El-Seginy, Samia A; Ali, Mamdouh M; Maher, Timothy J; Gugnani, Kuljeet S; Rondon-Ortiz, Alejandro N

    2017-09-01

    Breast and cervical cancers are the most common gender-specific cancers affecting women worldwide. In this investigation, we highlighted the synthesis, VEGFR-2 and p38α MAPK inhibitory activity of new series of fluorinated coumarin-based derivatives featuring a variety of bioactive chemical moieties attached or fused to the coumarin nucleus at the 3 and/or 4 position. The bioactive inhibitors were further assessed for their anti-proliferative effect against human MCF-7 breast cancer and HeLa cervical cancer cell lines, respectively. Most of the tested compounds showed potent preferential inhibition effects against human VEGFR-2 and remarkable anticancer activities in the human breast cancer cell line MCF-7. Compounds 29, 24, and 2 displayed the highest inhibitory activity against VEGFR-2 (94% inhibition) and they were the most potent anticancer agents toward MCF-7 cancer cells with IC50 values of 7.90, 8.28, and 8.30 μg/mL, respectively. Compound 13 inhibited p38α MAPK phosphorylation with a significant reduction in % cell viability against HeLa cancer cells at 10 and 30 µM. Docking experiments carried out on VEGFR-2 and p38 MAPK crystallographic structures revealed that the active compounds bind to the active sites through H-bonds, arene-cation, and hydrophobic π-π interactions. QSAR analysis demonstrated considerable correlation coefficient (R(2)  = 0.76969) and root mean square error (RMSE = 0.10446) values. Also, the residual values between the experimental pIC50 and predicted pIC50 are very close, indicating the reliability of the established QSAR model. © 2017 Deutsche Pharmazeutische Gesellschaft.

  9. Toll-like receptor 2/6-dependent stimulation of mesenchymal stem cells promotes angiogenesis by paracrine factors

    Directory of Open Access Journals (Sweden)

    H Kokemüller

    2013-09-01

    Full Text Available Reconstruction of critical size bone defects represents a major challenge in orthopaedic surgery. Insufficient angiogenesis is a limiting factor for engraftment of large-scale tissue transplants. Transplantation or stimulation of local mesenchymal stem cells (MSCs represents a potential solution to enhance angiogenesis. We recently identified angiogenic properties for the Toll-like receptor (TLR 2/6 agonist MALP-2 and now investigated if MALP-2 could be used to stimulate MSCs in order to promote angiogenesis in vitro and in vivo.Human MSCs from the bone marrow of healthy subjects were isolated, cultured and expanded in vitro and were shown to be positive for mesenchymal stem cells markers as well as for the MALP-2 receptors TLR2 and TLR6. MALP-2 directly enhanced migration but not proliferation of human MSCs. Conditioned medium from MALP-2 stimulated MSCs significantly increased proliferation, migration and tube formation of endothelial cells. Analysis of the conditioned medium from MSCs revealed that MALP-2 stimulation enhanced the secretion of several chemokines and growth factors including vascular endothelial growth factors (VEGF and granulocyte-macrophage colony-stimulating factor (GM-CSF. Finally, we studied MALP-2 effects on MSCs in a sheep model of tissue engineering in vivo. Therefore, MSCs were isolated from the iliac crest of black head sheep and co-cultivated with MALP-2 ex vivo. Implantation of autologous MSCs within a scaffold cylinder into the M. latissimus dorsi significantly enhanced vessel density of these constructs after 6 months.We here present the first evidence that TLR2/6-dependent stimulation of MSCs promotes angiogenesis in vitro and in vivo offering a novel strategy for therapeutic angiogenesis, e.g., for tissue engineering of bone.

  10. Specific anti-tumor effect induced by attenuated Salmonella typhimurium vaccine expressing extracellular region of vascular endothelial growth factor receptor 2

    Institute of Scientific and Technical Information of China (English)

    YANG Jun; DONG Jian; PU Ping; WANG ZhiQiang; HONG Min; CHEN MingQing

    2008-01-01

    The purposes of this research were to study the stable expression of exogenous gene encoding therapeutic protein in attenuated Salmonella typhimurium, observe the metabolism of oral gene vac-cine carried by attenuated Salmonella typhimurium in BALB/c mouse, and investigate the feasibility of prevention and treatment of tumors by the recombinant bacteria. Recombinant plasmid pcDNA3.1+ VEGFR2(n1-7) was transformed into competent attenuated Salmonella typhimurium SL3261 to develop oral DNA vaccine SL3261-pcDNA3.1+VEGFR2(n1-7). To observe whether the exogenous gene can be ex-pressed in the recombinant bacteria, PCR was performed to amplify the CMV promoter of the eu-karyotic expression vector as the proof of stable expression of exogenous protein; transmission elec-tron microscopy (TEM) was applied to observe the morphology of the recombinant bacteria to confirm that the exogenous gene has no impact on the growth of the bacteria, and then BALB/c mice were immunized with the gene vaccine. After inoculation of the gene vaccine, the recombinant bacteria SL3261 could be detected in the tissues such as small intestine, colon, liver and spleen. And then, mice in each group were challenged with tumor cells. The results of animal experiment showed that tumor growth of the mice in experimental group was inhibited and survival time of immunized mice was pro-longed compared with control groups. A higher lymphocyte infiltration in tumors from animals treated with DNA vaccine was observed. Immunohistochemical analysis of tumor samples revealed an en-hanced accumulation of CD8+ cytotoxic T lymphocytes, as well as an increase in CD4+ cells in the tu-mors of animals treated with the oral gene vaccine compared to tumors from control group mice. UI-trastructure of the tumor tissue showed that tumor cells in the samples of the immunized mice were well-differentiated. Our research confirmed that the exogenous gene can be stably expressed in the attenuated Salmonella typhimurium and has no

  11. Human epidermal growth factor receptor-2 overexpression and amplification in metastatic and recurrent high grade or type 2 endometrial carcinomas

    Directory of Open Access Journals (Sweden)

    Kato R

    2013-08-01

    Full Text Available Rina Kato,1 Kiyoshi Hasegawa,1 Risa Ishii,1 Akiko Owaki,1 Yutaka Torii,1 Shuko Oe,1 Hiroshi Hirasawa,2 Yoichi Kobayashi,3 Yasuhiro Udagawa1 1Department of Obstetrics and Gynecology, Fujita Health University School of Medicine, Toyoake, Japan; 2Department of Pathology, Fujita Health University School of Medicine, Toyoake, Japan; 3Department of Obstetrics and Gynecology, Kyorin University School of Medicine, Mitaka, Japan Introduction: Human epidermal growth factor receptor (HER-2 overexpression or gene amplification is more common in high-grade or type 2 endometrial carcinomas. We assessed the discordance of HER-2 expression between primary and metastatic or recurrent endometrial carcinomas. Materials and methods: Thirty-six primary, along with 14 metastatic and five recurrent tumors (matched to primaries, pathologically confirmed as high-grade or type 2 endometrial carcinomas, were submitted for immunohistochemistry (IHC for HER-2. Fluorescence in situ hybridization was performed when the tumors showed HER-2 overexpression (≥2+ IHC score. The results of the IHC and fluorescence in situ hybridization assays were compared between the primary and metastatic or recurrent tumors. The relationships between HER-2 expression and clinicopathological factors or prognosis were investigated. Results: HER-2 overexpression and HER-2 amplification (a ratio of HER-2 copies to chromosome 17 [CEP17] copies ≥2.2 were detected in 33.3% (twelve of 36 patients and 5.6% (two of 36 patients of primary tumors, respectively. HER-2 overexpression was not associated with clinicopathological factors or prognosis. In 19 tumor specimens obtained from metastatic or recurrent tumors, HER-2 overexpression and HER-2 amplification were detected in 57.9% (eleven patients and 15.8% (three patients, respectively. HER-2 overexpression tended to predict a worse prognosis. Conclusion: HER-2 expression in metastatic or recurrent tumors was more frequent than in matched primary high

  12. Fibroblast growth factor receptor 2 (FGFR2) is required for corneal epithelial cell proliferation and differentiation during embryonic development.

    Science.gov (United States)

    Zhang, Jinglin; Upadhya, Dinesh; Lu, Lin; Reneker, Lixing W

    2015-01-01

    Fibroblast growth factors (FGFs) play important roles in many aspects of embryonic development. During eye development, the lens and corneal epithelium are derived from the same surface ectodermal tissue. FGF receptor (FGFR)-signaling is essential for lens cell differentiation and survival, but its role in corneal development has not been fully investigated. In this study, we examined the corneal defects in Fgfr2 conditional knockout mice in which Cre expression is activated at lens induction stage by Pax6 P0 promoter. The cornea in LeCre, Fgfr2(loxP/loxP) mice (referred as Fgfr2(CKO)) was analyzed to assess changes in cell proliferation, differentiation and survival. We found that Fgfr2(CKO) cornea was much thinner in epithelial and stromal layer when compared to WT cornea. At embryonic day 12.5-13.5 (E12.5-13.5) shortly after the lens vesicle detaches from the overlying surface ectoderm, cell proliferation (judged by labeling indices of Ki-67, BrdU and phospho-histone H3) was significantly reduced in corneal epithelium in Fgfr2(CKO) mice. At later stage, cell differentiation markers for corneal epithelium and underlying stromal mesenchyme, keratin-12 and keratocan respectively, were not expressed in Fgfr2(CKO) cornea. Furthermore, Pax6, a transcription factor essential for eye development, was not present in the Fgfr2(CKO) mutant corneal epithelial at E16.5 but was expressed normally at E12.5, suggesting that FGFR2-signaling is required for maintaining Pax6 expression in this tissue. Interestingly, the role of FGFR2 in corneal epithelial development is independent of ERK1/2-signaling. In contrast to the lens, FGFR2 is not required for cell survival in cornea. This study demonstrates for the first time that FGFR2 plays an essential role in controlling cell proliferation and differentiation, and maintaining Pax6 levels in corneal epithelium via ERK-independent pathways during embryonic development.

  13. Increased depression-like behaviors in corticotropin-releasing factor receptor-2-deficient mice: sexually dichotomous responses.

    Science.gov (United States)

    Bale, Tracy L; Vale, Wylie W

    2003-06-15

    Depressive disorders affect nearly 19 million American adults, making depression and the susceptibility for developing depression a critical focus of mental health research today. Females are twice as likely to develop depression as males. Stress is a known risk factor for developing depression, and recent hypotheses suggest an involvement of an overactive stress axis. As mediators of the stress response, corticotropin-releasing factor (CRF) and its receptors (CRFR1 and CRFR2) have been implicated in the propensity for developing stress-related mood disorders. Mice deficient in CRFR2 display increased anxiety-like behaviors and a hypersensitive stress response. As a possible animal model of depression, these mice were tested for depression-like behaviors in the forced swim test. Comparisons were made between wild-type and mutant animals, as well as between sexes. Male and female CRFR2-mutant mice showed increased immobility as an indicator of depression compared with wild-type mice of the same sex. In addition, mutant and wild-type female mice demonstrated increased immobile time compared with males of the same genotype. Treatment of CRFR2-deficient mice with the CRFR1 antagonist antalarmin decreased immobile time and increased swim time in both sexes. We found a significant effect of sex for both time spent immobile and swimming after antalarmin treatment. Because differences in behaviors in the forced swim test are good indicators of serotonergic and catecholaminergic involvement, our results may reveal an interaction of CRF pathways with other known antidepressant systems and may also support an involvement of CRF receptors in the development of depression such that elevated CRFR1 activity, in the absence of CRFR2, increases depression-like behaviors.

  14. A variant of fibroblast growth factor receptor 2 (Fgfr2 regulates left-right asymmetry in zebrafish.

    Directory of Open Access Journals (Sweden)

    Da-Wei Liu

    Full Text Available Many organs in vertebrates are left-right asymmetrical located. For example, liver is at the right side and stomach is at the left side in human. Fibroblast growth factor (Fgf signaling is important for left-right asymmetry. To investigate the roles of Fgfr2 signaling in zebrafish left-right asymmetry, we used splicing blocking morpholinos to specifically block the splicing of fgfr2b and fgfr2c variants, respectively. We found that the relative position of the liver and the pancreas were disrupted in fgfr2c morphants. Furthermore, the left-right asymmetry of the heart became random. Expression pattern of the laterality controlling genes, spaw and pitx2c, also became random in the morphants. Furthermore, lefty1 was not expressed in the posterior notochord, indicating that the molecular midline barrier had been disrupted. It was also not expressed in the brain diencephalon. Kupffer's vesicle (KV size became smaller in fgfr2c morphants. Furthermore, KV cilia were shorter in fgfr2c morphants. We conclude that the fgfr2c isoform plays an important role in the left-right asymmetry during zebrafish development.

  15. Minimally invasive colon resection for malignant colonic conditions is associated with a transient early increase in plasma sVEGFR1 and a decrease in sVEGFR2 levels after surgery.

    Science.gov (United States)

    Shantha Kumara, H M C; Cabot, J C; Hoffman, A; Luchtefeld, M; Kalady, M F; Hyman, N; Feingold, D; Baxter, R; Whelan, R L

    2010-02-01

    Plasma VEGF levels increase after minimally invasive colorectal resection (MICR) and remain elevated for 2-4 weeks. VEGF induces physiologic and pathologic angiogenesis by binding to endothelial cell (EC) bound VEGF-Receptor-1 (VEGFR1) and VEGFR2. Soluble forms of these receptors sequester plasma VEGF, decreasing the amount available to bind to EC-bound receptors. Ramifications of surgery-related plasma VEGF changes partially depend on plasma levels of sVEGFR1 and sVEGFR2. This study assessed perioperative sVEGFR1 and sVEGFR2 levels after MICR in patients with colorectal cancer. Forty-five patients were studied; blood samples were taken from all patients preoperatively (preop) and on postoperative days (POD) 1 and 3; in most a fourth sample was drawn between POD 7-30. Late samples were bundled into two time points: POD 7-13 and POD 14-30. sVEGFR1 and sVEGFR2 levels were measured via ELISA. sVEGFR2 data are reported as mean +/- SD and were assessed with the paired samples t test. sVEGFR1 data were not normally distributed. They are reported as median and 95% confidence interval (CI) and were assessed with the Wilcoxon signed-Rank test (p MICR; sVEGFR2 changes dominate due to their much larger magnitude. The net result is less plasma VEGF bound by soluble receptors and more plasma VEGF available to bind to ECs early after surgery.

  16. 3D pharmacophore-based virtual screening, docking and density functional theory approach towards the discovery of novel human epidermal growth factor receptor-2 (HER2) inhibitors.

    Science.gov (United States)

    Gogoi, Dhrubajyoti; Baruah, Vishwa Jyoti; Chaliha, Amrita Kashyap; Kakoti, Bibhuti Bhushan; Sarma, Diganta; Buragohain, Alak Kumar

    2016-12-21

    Human epidermal growth factor receptor 2 (HER2) is one of the four members of the epidermal growth factor receptor (EGFR) family and is expressed to facilitate cellular proliferation across various tissue types. Therapies targeting HER2, which is a transmembrane glycoprotein with tyrosine kinase activity, offer promising prospects especially in breast and gastric/gastroesophageal cancer patients. Persistence of both primary and acquired resistance to various routine drugs/antibodies is a disappointing outcome in the treatment of many HER2 positive cancer patients and is a challenge that requires formulation of new and improved strategies to overcome the same. Identification of novel HER2 inhibitors with improved therapeutics index was performed with a highly correlating (r=0.975) ligand-based pharmacophore model (Hypo1) in this study. Hypo1 was generated from a training set of 22 compounds with HER2 inhibitory activity and this well-validated hypothesis was subsequently used as a 3D query to screen compounds in a total of four databases of which two were natural product databases. Further, these compounds were analyzed for compliance with Veber's drug-likeness rule and optimum ADMET parameters. The selected compounds were then subjected to molecular docking and Density Functional Theory (DFT) analysis to discern their molecular interactions at the active site of HER2. The findings thus presented would be an important starting point towards the development of novel HER2 inhibitors using well-validated computational techniques.

  17. Combined use of serum adiponectin and tumor necrosis factor-alpha receptor 2 levels was comparable to 2-hour post-load glucose in diabetes prediction.

    Directory of Open Access Journals (Sweden)

    Yu-Cho Woo

    Full Text Available BACKGROUND: Adipose tissue inflammation and dysregulated adipokine secretion are implicated in obesity-related insulin resistance and type 2 diabetes. We evaluated the use of serum adiponectin, an anti-inflammatory adipokine, and several proinflammatory adipokines, as biomarkers of diabetes risk and whether they add to traditional risk factors in diabetes prediction. METHODS: We studied 1300 non-diabetic subjects from the prospective Hong Kong Cardiovascular Risk Factor Prevalence Study (CRISPS. Serum adiponectin, tumor necrosis factor-alpha receptor 2 (TNF-α R2, interleukin-6 (IL-6, adipocyte-fatty acid binding protein (A-FABP and high-sensitivity C-reactive protein (hsCRP were measured in baseline samples. RESULTS: Seventy-six participants developed diabetes over 5.3 years (median. All five biomarkers significantly improved the log-likelihood of diabetes in a clinical diabetes prediction (CDP model including age, sex, family history of diabetes, smoking, physical activity, hypertension, waist circumference, fasting glucose and dyslipidaemia. In ROC curve analysis, "adiponectin + TNF-α R2" improved the area under ROC curve (AUC of the CDP model from 0.802 to 0.830 (P = 0.03, rendering its performance comparable to the "CDP + 2-hour post-OGTT glucose" model (AUC = 0.852, P = 0.30. A biomarker risk score, derived from the number of biomarkers predictive of diabetes (low adiponectin, high TNF-α R2, had similar performance when added to the CDP model (AUC = 0.829 [95% CI: 0.808-0.849]. CONCLUSIONS: The combined use of serum adiponectin and TNF-α R2 as biomarkers provided added value over traditional risk factors for diabetes prediction in Chinese and could be considered as an alternative to the OGTT.

  18. Association between fibroblast growth factor receptor-2 gene polymorphism and risk of breast cancer in Chinese populations: A HuGE review and meta-analysis.

    Science.gov (United States)

    Yang, Yong-Bin; Zhao, Zhan-Xue; Huang, Wei; Liu, Hui; Tan, Yan-Li; Wang, Wei-Ming

    2016-01-01

    To evaluate the effect of fibroblast growth factor receptor.2. (FGFR2) on genetic susceptibility for breast cancer. (BC) in Chinese populations. A computerized literature search was carried out in PubMed, Chinese Biomedical Database. (CBM), and Chinese National Knowledge Infrastructure. (CNKI) to collect relevant articles. Pooled odds ratio. (OR) and 95% confidence interval. (CI) were used to assess the strength of the associations. A total of 21 articles involving a total of 15 polymorphisms of the FGFR2 gene were included in the meta-analysis. Due to the limited studies for rs17102287, rs2981578, rs3135718, rs3803662, rs3750817, rsl0510097, rsl7542768, rs13387042, and rs1982073; we only pooled the six polymorphisms. (rs11200014, rs1219648, rs2420946, rs2912778, rs2981579, and rs2981582) into this meta. Overall, significantly increased BC risk was associated with five polymorphisms. (rs2981579, rs2981582, rs1219648, rs2420946, and rs2912778) when all studies were pooled into the meta. When stratified by ethnicity and source of controls, similar results were also detected. However, for rs2981579 no significant association was found among Chinese Han in all genetic models. Our meta-analysis suggests that FGFR2 is likely an important genetic marker contributing to susceptibility of BC. We recommend that these single nucleotide polymorphisms to be included in future association studies and functional assays.

  19. Treatment challenges for community oncologists treating postmenopausal women with endocrine-resistant, hormone receptor-positive, human epidermal growth factor receptor 2-negative advanced breast cancer

    Directory of Open Access Journals (Sweden)

    Gradishar WJ

    2016-07-01

    Full Text Available William J Gradishar Division of Hematology/Oncology, Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL, USA Abstract: Community-based oncologists are faced with challenges and opportunities when delivering quality patient care, including high patient volumes and diminished resources; however, there may be the potential to deliver increased patient education and subsequently improve outcomes. This review discusses the treatment of postmenopausal women with endocrine-resistant, hormone receptor-positive, human epidermal growth factor receptor 2-negative advanced breast cancer in order to illustrate considerations in the provision of pertinent quality education in the treatment of these patients and the management of therapy-related adverse events. An overview of endocrine-resistant breast cancer and subsequent treatment challenges is also provided. Approved treatment options for endocrine-resistant breast cancer include hormonal therapies and mammalian target of rapamycin inhibitors. Compounds under clinical investigation are also discussed. Keywords: community oncologists, hormone receptor-positive advanced breast cancer, endocrine resistance

  20. Obesity increases the incidence of distant metastases in oestrogen receptor-negative human epidermal growth factor receptor 2-positive breast cancer patients.

    Science.gov (United States)

    Mazzarella, Luca; Disalvatore, Davide; Bagnardi, Vincenzo; Rotmensz, Nicole; Galbiati, Donata; Caputo, Sara; Curigliano, Giuseppe; Pelicci, Pier Giuseppe

    2013-11-01

    Obesity is a major negative determinant of breast cancer outcome. However, there are contrasting data on the differential impact of obesity on specific breast cancer subtypes. In particular, very little is known on human epidermal growth factor receptor 2-positive (HER2+) tumours. We assessed the prognostic role of increased body mass index (BMI) on a consecutive series of non-metastatic HER2+ patients treated at our institution before the introduction of adjuvant Trastuzumab. We separately analysed oestrogen receptor-positive (ER+) and -negative (ER-) HER2+ cases. In ER-/HER2+ tumours we observed a significantly worse overall survival (Hazard ratio (HR) 1.79, p-value 0.041) and cumulative incidence of distant metastases (HR 2.03, p-value 0.019) in obese (BMI>30) versus normal/underweight (BMIobese patients, masking the overall effect on disease-free survival. Outcome in ER+ tumours, instead, was not significantly different between BMI groups. Obesity significantly correlates with worse overall survival and cumulative incidence of distant metastases in ER-/HER2 positive breast cancer. Differences in the biology of breast tumours may determine individual susceptibility to obesity. The biology of the underlying tumour should be taken into account in the design of dietary intervention trials in breast cancer. Copyright © 2013 Elsevier Ltd. All rights reserved.

  1. Antitumor activity of a combination of trastuzumab (Herceptin) and oral fluoropyrimidine S-1 on human epidermal growth factor receptor 2-overexpressing pancreatic cancer.

    Science.gov (United States)

    Saeki, Hiroyuki; Yanoma, Shunsuke; Takemiya, Shouji; Sugimasa, Yukio; Akaike, Makoto; Yukawa, Norio; Rino, Yasushi; Imada, Toshio

    2007-08-01

    The cytotoxic effect of trastuzumab in combination with oral fluoropyrimidine S-1 on human epidermal growth factor receptor 2 (HER2)-overexpressing human pancreatic cancer cell line TRG in vitro and in vivo was investigated. HER2 expression in TRG was analyzed by RT-PCR and flow cytometry. For in vitro experiments, 5-fluorouracil (5-FU) was used instead of S-1. In vivo studies were conducted with TRG xenografts in athymic mice. Trastuzumab (10 mg/kg) was administered intraperitoneally once a week for 4 weeks. S-1 (10 mg/kg) was administered orally 5 days a week for 4 weeks. The results showed that TRG cells were positive for HER2 mRNA and overexpressed HER2 protein. Either trastuzumab or 5-FU concentration-dependently inhibited the growth of TRG cells. The combination of trastuzumab and 5-FU resulted in a significant inhibition of growth of TRG cells compared to either agent alone (P<0.001). Incubation of TRG cells with peripheral blood mononuclear cells after treatment with trastuzumab enhanced the antiproliferative effect of trastuzumab, which could be the result of antibody-dependent cellular cytotoxicity. The combination of trastuzumab and S-1 resulted in a significant reduction in xenograft volume compared to each agent alone (P<0.0001). In conclusion, this study showed that combination therapy with trastuzumab and S-1 may be effective for HER2-overexpressing pancreatic cancer patients.

  2. Patterns of resource utilization and cost for postmenopausal women with hormone-receptor-positive, human epidermal growth factor receptor-2-negative advanced breast cancer in Europe.

    Science.gov (United States)

    Jerusalem, Guy; Neven, Patrick; Marinsek, Nina; Zhang, Jie; Degun, Ravi; Benelli, Giancarlo; Saletan, Stephen; Ricci, Jean-François; Andre, Fabrice

    2015-10-24

    Healthcare resource utilization in breast cancer varies by disease characteristics and treatment choices. However, lack of clarity in guidelines can result in varied interpretation and heterogeneous treatment management and costs. In Europe, the extent of this variability is unclear. Therefore, evaluation of chemotherapy use and costs versus hormone therapy across Europe is needed. This retrospective chart review (N = 355) examined primarily direct costs for chemotherapy versus hormone therapy in postmenopausal women with hormone-receptor-positive (HR+), human epidermal growth factor receptor-2-negative (HER2-) advanced breast cancer across 5 European countries (France, Germany, The Netherlands, Belgium, and Sweden). Total direct costs across the first 3 treatment lines were approximately €10,000 to €14,000 lower for an additional line of hormone therapy-based treatment versus switching to chemotherapy-based treatment. Direct cost difference between chemotherapy-based and hormone therapy-based regimens was approximately €1900 to €2500 per month. Chemotherapy-based regimens were associated with increased resource utilization (managing side effects; concomitant targeted therapy use; and increased frequencies of hospitalizations, provider visits, and monitoring tests). The proportion of patients taking sick leave doubled after switching from hormone therapy to chemotherapy. These results suggest chemotherapy is associated with increased direct costs and potentially with increased indirect costs (lower productivity of working patients) versus hormone therapy in HR+, HER2- advanced breast cancer.

  3. Fragment-based discovery of a dual pan-RET/VEGFR2 kinase inhibitor optimized for single-agent polypharmacology1

    OpenAIRE

    Frett, Brendan; Carlomagno, Francesca; Moccia, Maria Luisa; Brescia, Annalisa; Federico, Giorgia; De Falco, Valentina; Admire, Brittany; Chen, Zhongzhu; Qi, Wenqing; Santoro, Massimo; Li, Hong-yu

    2015-01-01

    Oncogenic conversion of the RET (rearranged during transfection) tyrosine kinase is associated with several cancers. A fragment-based chemical screen lead to the identification of a novel RET inhibitor, Pz-1. Modeling and kinetic analysis identified Pz-1 as a Type-II tyrosine kinase inhibitor, able to bind the DFG-out conformation of the kinase. Importantly, from a single-agent polypharmacology standpoint, Pz-1 was shown active on VEGFR2, which can block blood supply required for RET-stimulat...

  4. A role for fibroblast growth factor receptor-2 in the altered osteoblast phenotype induced by Twist haploinsufficiency in the Saethre-Chotzen syndrome.

    Science.gov (United States)

    Guenou, Hind; Kaabeche, Karim; Mée, Sandrine Le; Marie, Pierre J

    2005-06-01

    Genetic mutations of Twist, a bHLH transcription factor, induce premature fusion of cranial sutures (craniosynostosis) in the Saethre-Chotzen syndrome (SCS). The mechanisms by which Twist haploinsufficiency may alter osteoblast differentiation are poorly understood. In this study, we investigated the role of fibroblast growth factor receptor-2 (Fgfr2) in the abnormal osteoblast differentiation in SCS. Cranial osteoblasts from an SCS patient with a Y103X mutation inducing deletion of the Twist bHLH domain showed decreased Fgfr2 mRNA levels associated with decreased expression of Runx2, bone sialoprotein (BSP) and osteocalcin (OC), markers of differentiated osteoblasts, compared with wild-type osteoblasts. Transfection with Twist or Runx2 expression vectors, but not with Runx2 mutant which impairs DNA binding, restored Fgfr2, Runx2, BSP and OC expression in Twist mutant osteoblasts. EMSA analysis of mutant osteoblast nuclear extracts showed reduced Runx2 binding to a target OSE2 site in the Fgfr2 promoter. ChIP analyses showed that both Twist and Runx2 in mutant osteoblast nuclear extracts bind to a specific region in the Fgfr2 promoter. Significantly, forced expression of Fgfr2 restored Runx2 and osteoblast marker genes, whereas a dominant-negative Fgfr2 further decreased Runx2 and downstream genes in Twist mutant osteoblasts, indicating that alteration of Fgfr2 results in downregulation of osteoblast genes in Twist mutant osteoblasts. We conclude that Twist haploinsufficiency downregulates Fgfr2 mRNA expression, which in turn reduces Runx2 and downstream osteoblast-specific genes in human calvarial osteoblasts. This provides genetic and biochemical evidence for a role of Fgfr2 in the altered osteoblast phenotype induced by Twist haploinsufficiency in the SCS.

  5. Antitumor effect of afatinib, as a human epidermal growth factor receptor 2-targeted therapy, in lung cancers harboring HER2 oncogene alterations.

    Science.gov (United States)

    Suzawa, Ken; Toyooka, Shinichi; Sakaguchi, Masakiyo; Morita, Mizuki; Yamamoto, Hiromasa; Tomida, Shuta; Ohtsuka, Tomoaki; Watanabe, Mototsugu; Hashida, Shinsuke; Maki, Yuho; Soh, Junichi; Asano, Hiroaki; Tsukuda, Kazunori; Miyoshi, Shinichiro

    2016-01-01

    Human epidermal growth factor receptor 2 (HER2) is a member of the HER family of proteins containing four receptor tyrosine kinases. It plays an important role in the pathogenesis of certain human cancers. In non-small-cell lung cancer (NSCLC), HER2 amplification or mutations have been reported. However, little is known about the benefit of HER2-targeted therapy for NSCLCs harboring HER2 alterations. In this study, we investigated the antitumor effect of afatinib, an irreversible epidermal growth factor receptor (EGFR)-HER2 dual inhibitor, in lung cancers harboring HER2 oncogene alterations, including novel HER2 mutations in the transmembrane domain, which we recently identified. Normal bronchial epithelial cells, BEAS-2B, ectopically overexpressing wild-type HER2 or mutants (A775insYVMA, G776VC, G776LC, P780insGSP, V659E, and G660D) showed constitutive autophosphorylation of HER2 and activation of downstream signaling. They were sensitive to afatinib, but insensitive to gefitinib. Furthermore, we examined the antitumor activity of afatinib and gefitinib in several NSCLC cell lines, and investigated the association between their genetic alterations and sensitivity to afatinib treatment. In HER2-altered NSCLC cells (H2170, Calu-3, and H1781), afatinib downregulated the phosphorylation of HER2 and EGFR as well as their downstream signaling, and induced an antiproliferative effect through G1 arrest and apoptotic cell death. In contrast, HER2- or EGFR-non-dependent NSCLC cells were insensitive to afatinib. In addition, these effects were confirmed in vivo by using a xenograft mouse model of HER2-altered lung cancer cells. Our results suggest that afatinib is a therapeutic option as a HER2-targeted therapy for NSCLC harboring HER2 amplification or mutations.

  6. Relationship between serum tumor necrosis factor receptor-2 concentration and periodontal destruction in patients with type 2 diabetes: Cross-sectional study

    Directory of Open Access Journals (Sweden)

    Matić-Petrović Sanja

    2016-01-01

    Full Text Available Introduction. The role of tumor necrosis factor-α (TNFα is well documented in pathogenesis of chronic periodontitis (CP and type 2 diabetes (T2D. Considering short half-life of TNFα, tumor necrosis factor receptor-2 (TNFR2 is used as prosperous surrogate marker of TNFα activity. Objective. The aim was to detect TNFR2 serum concentration and correlate it with periodontal destruction in patients with diagnosed T2D and nondiabetics. Methods. The study included 85 patients divided into three groups: T2D + CP (group T2D, n = 34; nondiabetics + CP (Group PD, n = 27; and healthy controls (group HC, n = 24. T2D was diagnosed according to WHO criteria (2013 and periodontitis was diagnosed using International Workshop for a Classification of Periodontal Diseases and Conditions criteria (1999. TNFR2 level was measured by enzyme-linked immunosorbent assay (ELISA. Results. There was no difference in TNFR2 level among the groups (Kruskal-Wallis, p = 0.482. Significant correlation (Pearson’s correlation coefficient was observed between clinical attachment loss (CAL and TNFR2 concentration in PD group (rp = -0.460, p = 0.016. In T2D group, correlations were observed between TNFR2 concentration and CAL (rp = 0.363, p = 0.005 and periodontal inflamed surface area (PISA (rp = 0.345, p = 0.046 and periodontal epithelial surface area (PESA (rp = 0.578, p = 0.000. Conclusion. Higher concentration of TNFR2 was associated with higher CAL, PESA, and PISA scores in T2D group. Contrary to that, nondiabetics with higher values of CAL exhibited lower concentration of TNFR2, presenting potential protective effect on periodontal destruction. These results imply that diabetes may alter TNFR2 secretion originated from periodontium. [Projekat Ministarstva nauke Republike Srbije, br. 41008

  7. 血糖控制良好的2型糖尿病患者血清VEGF-A及其受体VEGFR1和VEGFR2含量检测%A preliminary evaluation of VEGF-A, VEGFR1 and VEGFR2 in patients with well-controlled type 2 diabetes mellitus

    Institute of Scientific and Technical Information of China (English)

    Barbara RUSZKOWSKA-CIASTEK; Alina SOKUP; Maciej W.SOCHA; Zofia RUPRECHT; Lidia HAAS; Barbara GRALCZYK; Krzysztof GRALCZYK; Grayna GADOMSKA; Danuta RO

    2014-01-01

      重要结论:研究结果表明,血糖控制良好的2型糖尿病患者血清中的 VEGF-A 及其受体 VEGFR1和VEGFR2的含量和健康志愿者基本一致,两者无统计学意义,这可能显示血糖水平的合理控制能延缓血管并发症的产生。同时,2型糖尿病患者的血清 VEGFR2含量和高密度脂蛋白胆固醇水平之间存在负相关,而血清VEGF-A、VEGFR2含量和甘油三脂水平之间存在正相关,这也表明糖尿病患者的血脂紊乱可能参与了血管生成的调节。

  8. Transforming growth factor beta receptor 2 (TGFBR2 changes sialylation in the microsatellite unstable (MSI Colorectal cancer cell line HCT116.

    Directory of Open Access Journals (Sweden)

    Jennifer Lee

    Full Text Available Aberrant glycosylation is a common feature of many malignancies including colorectal cancers (CRCs. About 15% of CRC show the microsatellite instability (MSI phenotype that is associated with a high frequency of biallelic frameshift mutations in the A10 coding mononucleotide microsatellite of the transforming growth factor beta receptor 2 (TGFBR2 gene. If and how impaired TGFBR2 signaling in MSI CRC cells affects cell surface glycan pattern is largely unexplored. Here, we used the TGFBR2-deficient MSI colon carcinoma cell line HCT116 as a model system. Stable clones conferring doxycycline (dox-inducible expression of a single copy wildtype TGFBR2 transgene were generated by recombinase-mediated cassette exchange (RMCE. In two independent clones, dox-inducible expression of wildtype TGFBR2 protein and reconstitution of its signaling function was shown. Metabolic labeling experiments using the tritiated sialic acid precursor N-acetyl-D-mannosamine (ManNAc revealed a significant decline (∼30% of its incorporation into newly synthesized sialoglycoproteins in a TGFBR2-dependent manner. In particular, we detected a significant decrease of sialylated ß1-integrin upon reconstituted TGFBR2 signaling which did not influence ß1-integrin protein turnover. Notably, TGFBR2 reconstitution did not affect the transcript levels of any of the known human sialyltransferases when examined by real-time RT- PCR analysis. These results suggest that reconstituted TGFBR2 signaling in an isogenic MSI cell line model system can modulate sialylation of cell surface proteins like ß1-integrin. Moreover, our model system will be suitable to uncover the underlying molecular mechanisms of altered MSI tumor glycobiology.

  9. Macrophage-elicited osteoclastogenesis in response to bacterial stimulation requires Toll-like receptor 2-dependent tumor necrosis factor-alpha production.

    Science.gov (United States)

    Ukai, Takashi; Yumoto, Hiromichi; Gibson, Frank C; Genco, Caroline Attardo

    2008-02-01

    The receptor activator of NF-kappaB ligand (RANKL) and the proinflammatory cytokines are believed to play important roles in osteoclastogenesis. We recently reported that the innate immune recognition receptor, Toll-like receptor 2 (TLR2), is crucial for inflammatory bone loss in response to infection by Porphyromonas gingivalis, the primary organism associated with chronic inflammatory periodontal disease. However, the contribution of macrophage-expressed TLRs to osteoclastogenesis has not been defined. In this study, we defined a requirement for TLR2 in tumor necrosis factor-alpha (TNF-alpha)-elicited osteoclastogenesis in response to exposure to P. gingivalis. Culture supernatant (CS) fluids from P. gingivalis-stimulated macrophages induced bone marrow macrophage-derived osteoclastogenesis. This activity was dependent on TNF-alpha and occurred independently of RANKL, interleukin-1beta (IL-1beta), and IL-6. CS fluids from P. gingivalis-stimulated TLR2(-/-) macrophages failed to express TNF-alpha, and these fluids induced significantly less osteoclast formation compared with that of the wild-type or the TLR4(-/-) macrophages. In addition, P. gingivalis exposure induced up-regulation of TLR2 expression on the cell surface of macrophages, which was demonstrated to functionally react to reexposure to P. gingivalis, as measured by a further increase in TNF-alpha production. These results demonstrate that macrophage-dependent TLR2 signaling is crucial for TNF-alpha-dependent/RANKL-independent osteoclastogenesis in response to P. gingivalis infection. Furthermore, the ability of P. gingivalis to induce the cell surface expression of TLR2 may contribute to the chronic inflammatory state induced by this pathogen.

  10. Pattern of hormone receptors and human epidermal growth factor receptor 2 status in sub-Saharan breast cancer cases: Private practice experience.

    Science.gov (United States)

    Nwafor, C C; Keshinro, S O

    2015-01-01

    Breast cancer is the most common cancer among women globally. With immunohistochemistry (IHC), breast cancer is classified into four groups based on IHC profile of estrogen receptor (ER)/progesterone receptor (PR) and human epidermal growth factor receptor 2 (HER2/neu) expression, positive (+) and/or negative (-). The IHC classification correlates well with intrinsic gene expression microarray categorization. ER-positive tumors may benefit from being treated with selective ER modulators and aromatase inhibitors, whereas patients with HER2/neu positive tumors have been shown to experience a significant survival advantage when treated with humanized monoclonal antibodies against HER2/neu. To determine ER/PR, HER2/neu expression and their association with histological prognostic markers in female breast carcinomas seen in a private diagnostic laboratory based in Lagos. Immunohistochemistry reports of breast cancer patients, which were diagnosed by histopathology section of a private diagnostic laboratory based in Lagos, Nigeria from August 2009 to August 2014. About 18.7% of breast cancers had IHC (ER, PR and HER2) done on them and were all females. The mean age of all subjects was 49.5 years (standard deviation, 13.2; range, 29-78 years). Most (95.8%) of the breast cancers were of invasive ductal carcinoma type, with 77.4% of them been >5 cm. IHC pattern was as follows: ER/PR+, HER2-=19 (39.6%), ER/PR-, HER2- (triple negative [TN])=14 (29.2%), ER/PR+, HER2+=9 (18.8%), ER/PR-, HER2+=6 (12.5%), corresponding to Lumina A, TN/basal-like, Lumina B and HER2 over expressed respectively. Triple negative breast cancers are common in our environment and affect young females most and could be contributory to the poorer prognosis of breast cancer in our environment.

  11. Soluble Human Epidermal Growth Factor Receptor 2 (sHER2 as a Potential Risk Assessment, Screening, and Diagnostic Biomarker of Lung Adenocarcinoma

    Directory of Open Access Journals (Sweden)

    Andre T. Baron

    2013-01-01

    Full Text Available Lung cancer is the leading cause of cancer-related death in the United States. Here, we evaluated the potential clinical utility of soluble human epidermal growth factor receptor 2 (sHER2 for the risk assessment, screening, and diagnosis of non-small cell lung cancer (NSCLC using an unmatched case-control study design. Serum sHER2 concentrations were measured by immunoassay in 244 primary NSCLC cases and 218 healthy controls. Wilcoxon rank-sum tests, logistic regression models, and receiver operating characteristic plots were used to assess whether sHER2 is associated with lung cancer. Median serum sHER2 concentrations are higher in patients with adenocarcinoma than squamous cell carcinoma regardless of gender, and sHER2 is a weak, independent biomarker of adenocarcinoma, but not of squamous cell carcinoma, adjusted for age and gender. The age-adjusted relative risk (odds of adenocarcinoma is 3.95 (95% CI: 1.22, 12.81 and 7.93 (95% CI: 2.26, 27.82 greater for women and men with high sHER2 concentrations (≥6.60 ng/mL vs. low sHER2 concentrations (≤1.85 ng/mL, respectively. When adjusted for each other, sHER2, age, and gender discern healthy controls from patients with primary adenocarcinomas of the lung with 85.9% accuracy. We conclude that even though serum sHER2 is not a strong, stand-alone discriminatory biomarker of adenocarcinoma, sHER2 may be a useful, independent covariate in multivariate risk assessment, screening, and diagnostic models of lung cancer.

  12. Clinicopathologic features and treatment outcomes of patients with human epidermal growth factor receptor 2-positive adenocarcinoma of the esophagus and gastroesophageal junction.

    Science.gov (United States)

    Phillips, B E; Tubbs, R R; Rice, T W; Rybicki, L A; Plesec, T; Rodriguez, C P; Videtic, G M; Saxton, J P; Ives, D I; Adelstein, D J

    2013-04-01

    Human epidermal growth factor receptor 2 (HER2) is overexpressed in 21% of gastric and 33% of gastroesophageal junction (GEJ) adenocarcinomas. Trastuzumab has been approved for metastatic HER2-positive gastric/GEJ cancer in combination with chemotherapy. This retrospective analysis was undertaken to better define the clinicopathologic features, treatment outcomes, and prognosis in patients with HER2-positive adenocarcinoma of the esophagus/GEJ. Pathologic specimens from 156 patients with adenocarcinoma of the esophagus/GEJ treated on clinical trials with chemoradiation and surgery were tested for HER2. Seventy-six patients also received 2 years of gefitinib. Baseline characteristics and treatment outcomes of the HER2-positive and negative patients were compared both in aggregate and separately for each of the two trials. Of 156 patients, 135 had sufficient pathologic material available for HER2 assessment. HER2 positivity was found in 23%; 28% with GEJ primaries and 15% with esophageal primaries (P= 0.10). There was no statistical difference in clinicopathologic features between HER2-positive and negative patients except HER2-negative tumors were more likely to be poorly differentiated (P < 0.001). Locoregional recurrence, distant metastatic recurrence, any recurrence, and overall survival were also statistically similar between the HER2-positive and the HER2-negative groups, in both the entire cohort and in the gefitinib-treated subset. Except for tumor differentiation, HER2-positive and negative patients with adenocarcinoma of the esophagus and GEJ do not differ in clinicopathologic characteristics and treatment outcomes. Given the demonstrated benefit of trastuzumab in HER2-positive gastric cancer and the similar incidence of HER2 overexpression in esophageal/GEJ adenocarcinoma, further evaluation of HER2-directed therapy in this disease seems indicated.

  13. Influence of gain-of-function mutation (Ser252Trp in fibroblast growth factor receptor 2 gene on long bone development

    Directory of Open Access Journals (Sweden)

    Peng CHEN

    2013-07-01

    Full Text Available Objective To observe the early postnatal long bone development in Fgfr2+/S252W mutant mice and littermate wild-type (WT mice, and explore the effect of continued function enhancement of fibroblast growth factor receptor 2 (FGFR2 gene on endochondral ossification. Methods A mouse model of Fgfr2+/S252W simulated human Apert syndrome was reproduced by knock-in technique, and then the gain-of-function mutation Fgfr2+/S252W mice and littermate WT mice were obtained after breeding and identification. Three Fgfr2+/S252W and same number of WT mice were sacrificed at 7, 10, 14 and 28 postnatal days respectively, and the morphology of long bone was examined with X-ray and Micro CT, the structure of bone and cartilage was observed by HE staining, and the expression of gene in growth plate was observed by immunohistochemical analysis. Results Fgfr2+/S252W mouse model exhibited typical craniosynostosis and brachycephalium of Apert syndrome, accompanied by short stature, growth retardation of long bone, delayed appearance of secondary ossification center, decrease of bone density and trabecula number. HE staining showed noticeable shortened zones of proliferation and hypertrophic chondrocytes, irregularity of cell arrangement, and small hypertrophic chondrocytes in the growth plates of the mutant mice. Immunohistochemical analysis revealed that the expression of genes related to chondrocytes proliferation and differentiation was decreased in mutant mice. Conclusions Gain-of-function mutation in FGFR2 may lead to abnormal development of long bone in mice. FGFR2 may have the function of regulating the development both of osteoblast and chondrocyte lineages, and play an important role in the process of skeletal development.

  14. Fragment-based discovery of a dual pan-RET/VEGFR2 kinase inhibitor optimized for single-agent polypharmacology1

    Science.gov (United States)

    Frett, Brendan; Carlomagno, Francesca; Moccia, Maria Luisa; Brescia, Annalisa; Federico, Giorgia; De Falco, Valentina; Admire, Brittany; Chen, Zhongzhu; Qi, Wenqing; Santoro, Massimo; Li, Hong-yu

    2015-01-01

    Oncogenic conversion of the RET (rearranged during transfection) tyrosine kinase is associated with several cancers. A fragment-based chemical screen lead to the identification of a novel RET inhibitor, Pz-1. Modeling and kinetic analysis identified Pz-1 as a Type-II tyrosine kinase inhibitor, able to bind the DFG-out conformation of the kinase. Importantly, from a single-agent polypharmacology standpoint, Pz-1 was shown active on VEGFR2, which can block blood supply required for RET-stimulated growth. In cell based assays, 1.0 nM of Pz-1 strongly inhibited phosphorylation of all tested RET oncoproteins. At 1.0 mg/kg/day per os, Pz-1 abrogated formation of tumors induced by RET-mutant fibroblasts and blocked phosphorylation of both RET and VEGFR2 in tumor tissue. Pz-1 featured no detectable toxicity up to 100.0 mg/kg, which indicated a large therapeutic window. This study validates the effectiveness and usefulness of a medicinal chemistry polypharmacology approach to obtain an inhibitor capable of targeting multiple oncogenic pathways PMID:26126987

  15. Inhibitory effect of humanized anti-VEGFR-2 ScFv-As2O3-stealth nanoparticles conjugate on growth of human hepatocellular carcinoma:in vitro andin vivo studies

    Institute of Scientific and Technical Information of China (English)

    Xiang-Bao Yin; Lin-Quan Wu; Hua-Qun Fu; Ming-Wen Huang; Kai Wang; Fan Zhou; Xin Yu; Kai-Yang Wang

    2014-01-01

    Objective:To investigate the inhibitory effect of humanized anti-VEGFR-2ScFv-As2O3-stealth nanoparticles conjugate on growth of human hepatocellular carcinoma bothin vitro andin vivo, which may be a potential agents with sensitivity and targeting ability for human hepatocellular cancer.Methods:Humanized anti-VEGFR-2ScFv-As2O3-stealth nanoparticles conjugate was previously constructed using ribosome display technology and antibody conjugate technology. In this combinedin vitro andin vivo study, the inhibitory effects of anti-VEGFR-2ScFv-As2O3-stealth nanoparticles conjugate on tumor growth, invasion, and metastasis was observed with human liver carcinoma cell lineBel7402 and normal cellL02 byMTT assay,Tanswell assay, Hochest33258 staining, andDNA ladder analysis.The anticancer activity and distribution of anti-VEGFR-2ScFv-As2O3-stealth nanoparticles was then verified in a mouse model ofBel7402 xenografts.Results:Anti-VEGFR-2ScFv-As2O3-stealth nanoparticles significantly inhibited the proliferation ofBel7402 in the3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay while had almost no effects onL02 cells.And the apoptosis inducing effects were proved byHochest33258 staining andDNA ladder analysis.Transwell assay found that the drug also inhibited the metastasis ability of tumor cells.Furthermore, anti-VEGFR-2ScFv-As2O3-stealth nanoparticles significantly delayed the growth ofBel7402 xenografts after administration(92.9%), followed byAs2O3-stealth nanoparticles, anti-VEGFR-2ScFv, andAs2O3(61.4%,58.8%,20.5%, P<0.05).The concentration ofAs2O3 in anti-VEGFR-2ScFv-As2O3-stealth nanoparticles group was more selectively.Conclusions:Anti-VEGFR-2ScFv-As2O3-stealth nanoparticles is a potent and selective anti-hepatocellular carcinoma agent which could inhibit the growth of liver cancer as a targeting agent bothin vitro andin vivo and also significantly inhibit angiogenesis.

  16. Tumor-infiltrating lymphocytes and response to neoadjuvant chemotherapy with or without carboplatin in human epidermal growth factor receptor 2-positive and triple-negative primary breast cancers.

    Science.gov (United States)

    Denkert, Carsten; von Minckwitz, Gunter; Brase, Jan C; Sinn, Bruno V; Gade, Stephan; Kronenwett, Ralf; Pfitzner, Berit M; Salat, Christoph; Loi, Sherene; Schmitt, Wolfgang D; Schem, Christian; Fisch, Karin; Darb-Esfahani, Silvia; Mehta, Keyur; Sotiriou, Christos; Wienert, Stephan; Klare, Peter; André, Fabrice; Klauschen, Frederick; Blohmer, Jens-Uwe; Krappmann, Kristin; Schmidt, Marcus; Tesch, Hans; Kümmel, Sherko; Sinn, Peter; Jackisch, Christian; Dietel, Manfred; Reimer, Toralf; Untch, Michael; Loibl, Sibylle

    2015-03-20

    Modulation of immunologic interactions in cancer tissue is a promising therapeutic strategy. To investigate the immunogenicity of human epidermal growth factor receptor 2 (HER2) -positive and triple-negative (TN) breast cancers (BCs), we evaluated tumor-infiltrating lymphocytes (TILs) and immunologically relevant genes in the neoadjuvant GeparSixto trial. GeparSixto investigated the effect of adding carboplatin (Cb) to an anthracycline-plus-taxane combination (PM) on pathologic complete response (pCR). A total of 580 tumors were evaluated before random assignment for stromal TILs and lymphocyte-predominant BC (LPBC). mRNA expression of immune-activating (CXCL9, CCL5, CD8A, CD80, CXCL13, IGKC, CD21) as well as immunosuppressive factors (IDO1, PD-1, PD-L1, CTLA4, FOXP3) was measured in 481 tumors. Increased levels of stromal TILs predicted pCR in univariable (P < .001) and multivariable analyses (P < .001). pCR rate was 59.9% in LPBC and 33.8% for non-LPBC (P < .001). pCR rates ≥ 75% were observed in patients with LPBC tumors treated with PMCb, with a significant test for interaction with therapy in the complete (P = .002) and HER2-positive (P = .006), but not the TNBC, cohorts. Hierarchic clustering of mRNA markers revealed three immune subtypes with different pCR rates (P < .001). All 12 immune mRNA markers were predictive for increased pCR. The highest odds ratios (ORs) were observed for PD-L1 (OR, 1.57; 95% CI, 1.34 to 1.86; P < .001) and CCL5 (OR, 1.41; 95% CI, 1.23 to 1.62; P < .001). Immunologic factors were highly significant predictors of therapy response in the GeparSixto trial, particularly in patients treated with Cb. After further standardization, they could be included in histopathologic assessment of BC. © 2014 by American Society of Clinical Oncology.

  17. 基于分子对接研究吲哚咔唑类小分子对Tie-2/VEGFR2的双效抑制作用模式%Studies on Interactions between Tie-2/VEGFR2 and Dihydroindazolocarbazole Dual Inhibitors via Molecular Docking

    Institute of Scientific and Technical Information of China (English)

    田元新; 张贤祚; 安林坤

    2012-01-01

    Dihydroindazolocarbazoles (DHI-carbazoles) are the potent dual inhibitors to VEGFR2 and Tie-2. In this work, the mechanism of interaction between VEGFR2/Tie-2 and DHI-carbazoles was performed with Surflex-dock. The results from molecular docking indicated that DHI-carbazoles competitively bound to the active site, which was the substrate ATP in VEGFR2/Tie-2 with high affinity. The differences of activity between VEGFR2 and Tie-2 resulted from the minor difference of active pockets. Hydro-phobic effect played a key role in the formation and stability. Hydrogen bond and electrostatic effect also contributed to the difference. This work elucidated the antitumor mechanism of the DHI-carbazoles as a dual potent inhibitor and provided theoretical basis for the design of tyrosine kinase inhibitors.%运用分子对接技术研究了吲哚咔唑类小分子对人血管内皮生长因子受体2 (VEGFR2)和人血管生成素受体Tie-2 (ANG-R-Tie-2)的双效抑制作用模式.研究结果表明,吲哚咔唑类小分子的双效抑制作用主要源于两种受体相似的活性口袋,小分子与两者的铰链区均可形成氢键,使其催化活性受到抑制,从而抑制肿瘤细胞的生长.抑制活性的差异主要源于活性口袋的细微差异所导致疏水、静电等相互作用的不同.其中,疏水作用的差异是影响配体选择性的主要原因,静电作用、氢键及空间位阻对结合稳定也有一定影响.该文的研究结果为多靶点酪氨酸激酶小分子抑制剂的设计及提高激酶抑制剂的选择性提供了重要的理论依据.

  18. Influence of blood-activating and blood-breaking medicines on the PCNA protein and VEGF mRNA, VEGFR-2 mRNA expression in the rat model with atherosclerosis%活血、破血药对动脉粥样硬化大鼠PCNA蛋白、VEGFmRNA、VEGFR-2mRNA表达的影响

    Institute of Scientific and Technical Information of China (English)

    谢海波; 罗尧岳; 莫新民; 吴亦之; 卢青; 徐豫湘; 李武

    2013-01-01

    Objective To discuss the influence of blood-activating(angelica sinensis and ligusticum wallichii) and blood-breaking medicines(rhizoma sparganii and curcuma zedoary) on the PCNA protein and VEGFmRNA,VEGFR-2 mRNA expressions in the aortic tunica intima of rats with atherosclerosis (AS).Methods 60 male Wistar rats were randomly divided into 5 groups (including blank group,model group,statins group,blood-activating medicine group and blood-breaking medicine group) and AS rat model was established by feeding high-fat forage.These medicines were given by intragastric administration for 4 weeks.After treatment,PCNA protein expression level was detected with immunohistochemical staining method and the VEGF mRNA,VEGFR-2 mRNA gene expression levels were tested with hybridization in situ of the aortic tunica intima.Results The positive cell amount of PCNA in the blood-breaking medicine group was lower than that in the blood-activating medicine group (P<0.05).The VEGF mRNA and VEGFR-2 mRNA average gray values in the model group were higher than those in the blank group,statins group,blood-activating medicine group and blood-breaking medicine group,while there were no significant differences between blood-activating medicine group and blood-breaking medicine group.Conclusion Angelica sinensis,Ligusticum wallichii,rhizoma sparganii and curcuma zedoary can inhibit the expression of PCNA protein,VEGF mRNA and VEGFR-2 mRNA,and then inhibit the cell proliferation.The inhibiting effects on the PCNA expression of blood-breaking medicines (rhizoma sparganii and curcuma zedoary) are better than those of bloodactivating medicines(Angelica sinensis and Ligusticum wallichii).%目的 探讨活血药(当归、川芎)、破血药(三棱、莪术)对动脉粥样硬化(AS)的大鼠主动脉增殖细胞核抗原(PCNA)蛋白及血管内皮生长因子(VEGFmRNA)、血管内皮生长因子受体(VEGFR-AS)表达的影响.方法 将60只雄性Wistar大鼠随机分为5组(空白组、模型组、

  19. Circulating-free DNA Mutation Associated with Response of Targeted Therapy in Human Epidermal Growth Factor Receptor 2-positive Metastatic Breast Cancer

    Science.gov (United States)

    Ye, Qing; Qi, Fan; Bian, Li; Zhang, Shao-Hua; Wang, Tao; Jiang, Ze-Fei

    2017-01-01

    Background: The addition of anti-human epidermal growth factor receptor 2 (HER2)-targeted drugs, such as trastuzumab, lapatinib, and trastuzumab emtansine (T-DM1), to chemotherapy significantly improved prognosis of HER2-positive breast cancer patients. However, it was confused that metastatic patients vary in the response of targeted drug. Therefore, methods of accurately predicting drug response were really needed. To overcome the spatial and temporal limitations of biopsies, we aimed to develop a more sensitive and less invasive method of detecting mutations associated with anti-HER2 therapeutic response through circulating-free DNA (cfDNA). Methods: From March 6, 2014 to December 10, 2014, 24 plasma samples from 20 patients with HER2-positive metastatic breast cancer who received systemic therapy were eligible. We used a panel for detection of hot-spot mutations from 50 oncogenes and tumor suppressor genes, and then used targeted next-generation sequencing (NGS) to identify somatic mutation of these samples in those 50 genes. Samples taken before their first trastuzumab administration and subsequently proven with clinical benefit were grouped into sensitive group. The others were collected after disease progression of the trastuzumab-based therapy and were grouped into the resistant group. Results: A total of 486 single-nucleotide variants from 46 genes were detected. Of these 46 genes, phosphatidylinositol 4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA), proto-oncogene c-Kit (KIT), and tumor protein p53 (TP53) were the most common mutated genes. Seven genes, including epidermal growth factor receptor (EGFR), G protein subunit alpha S (GNAS), HRas proto-oncogene (HRAS), mutL homolog 1 (MLH1), cadherin 1 (CDH1), neuroblastoma RAS viral oncogene homolog (NRAS), and NOTCH1, that only occurred mutations in the resistant group were associated with the resistance of targeted therapy. In addition, we detected a HER2 S855I mutation in two patients who had

  20. Relationship between body mass index and the expression of hormone receptors or human epidermal growth factor receptor 2 with respect to breast cancer survival.

    Science.gov (United States)

    Jeon, Ye Won; Kang, Su Hwan; Park, Min Ho; Lim, Woosung; Cho, Se Heun; Suh, Young Jin

    2015-11-06

    The association between body mass index (BMI) at the time of breast cancer diagnosis and the prognosis of breast cancer patients remains controversial. Furthermore, the association between BMI and prognosis with respect to different breast cancer subtypes is not clearly defined. We analyzed data from 41,021 invasive breast cancer patients between January 1988 and February 2008 from the Korean Breast Cancer Registry (KBCR) database. Overall survival (OS) and breast cancer-specific survival (BCSS) were analyzed using the Kaplan-Meier method and Cox's proportional hazard regression model among all patients and specific breast cancer subtypes with respect to BMI categories. A U-shaped association between BMI and mortality was observed in the total cohort. Underweight and obese individuals exhibited worse OS (hazard ratio, 1.23 [95 % confidence interval {CI}, 1.05 to 1.44] and 1.29 [1.13 to 1.48], respectively) and BCSS (1.26 [1.03 to 1.54] and 1.21 [1.02 to 1.43], respectively) than normal-weight individuals. In the estrogen receptor (ER) and/or progesterone receptor (PR)+/human epidermal growth factor receptor 2 (HER2) - subgroup, obese individuals exhibited worse OS (1.48 [1.18 to 1.85]) and BCSS (1.31 [1.13 to 1.52]) than normal-weight individuals. Conversely, in the ER and PR-/HER2+ subgroup, underweight individuals exhibited worse OS (1.68 [1.12 to 2.47]) and BCSS (1.79 [1.11 to 2.90]) than normal-weight individuals. We observed a U-shaped relationship between BMI at diagnosis and poor OS and BCSS among all breast cancer patients. However, obesity in the ER and/or PR+/HER2- subgroup and underweight in the ER and PR-/HER2+ subgroup were poor prognostic factors. Therefore, BMI at diagnosis and breast cancer subtype should be considered simultaneously in various treatment decision processes and surveillance schedules.

  1. Leptin-induced transphosphorylation of vascular endothelial growth factor receptor increases Notch and stimulates endothelial cell angiogenic transformation.

    Science.gov (United States)

    Lanier, Viola; Gillespie, Corey; Leffers, Merle; Daley-Brown, Danielle; Milner, Joy; Lipsey, Crystal; Webb, Nia; Anderson, Leonard M; Newman, Gale; Waltenberger, Johannes; Gonzalez-Perez, Ruben Rene

    2016-10-01

    Leptin increases vascular endothelial growth factor (VEGF), VEGF receptor-2 (VEGFR-2), and Notch expression in cancer cells, and transphosphorylates VEGFR-2 in endothelial cells. However, the mechanisms involved in leptin's actions in endothelial cells are not completely known. Here we investigated whether a leptin-VEGFR-Notch axis is involved in these leptin's actions. To this end, human umbilical vein and porcine aortic endothelial cells (wild type and genetically modified to overexpress VEGFR-1 or -2) were cultured in the absence of VEGF and treated with leptin and inhibitors of Notch (gamma-secretase inhibitors: DAPT and S2188, and silencing RNA), VEGFR (kinase inhibitor: SU5416, and silencing RNA) and leptin receptor, OB-R (pegylated leptin peptide receptor antagonist 2: PEG-LPrA2). Interestingly, in the absence of VEGF, leptin induced the expression of several components of Notch signaling pathway in endothelial cells. Inhibition of VEGFR and Notch signaling significantly decreased leptin-induced S-phase progression, proliferation, and tube formation in endothelial cells. Moreover, leptin/OB-R induced transphosphorylation of VEGFR-1 and VEGFR-2 was essential for leptin's effects. These results unveil for the first time a novel mechanism by which leptin could induce angiogenic features via upregulation/trans-activation of VEGFR and downstream expression/activation of Notch in endothelial cells. Thus, high levels of leptin found in overweight and obese patients might lead to increased angiogenesis by activating VEGFR-Notch signaling crosstalk in endothelial cells. These observations might be highly relevant for obese patients with cancer, where leptin/VEGFR/Notch crosstalk could play an important role in cancer growth, and could be a new target for the control of tumor angiogenesis.

  2. A study on genetic variants of Fibroblast growth factor receptor 2 (FGFR2 and the risk of breast cancer from North India.

    Directory of Open Access Journals (Sweden)

    Sarah Siddiqui

    Full Text Available Genome-Wide Association Studies (GWAS have identified Fibroblast growth factor receptor 2 (FGFR2 as a candidate gene for breast cancer with single nucleotide polymorphisms (SNPs located in intron 2 region as the susceptibility loci strongly associated with the risk. However, replicate studies have often failed to extrapolate the association to diverse ethnic regions. This hints towards the existing heterogeneity among different populations, arising due to differential linkage disequilibrium (LD structures and frequencies of SNPs within the associated regions of the genome. It is therefore important to revisit the previously linked candidates in varied population groups to unravel the extent of heterogeneity. In an attempt to investigate the role of FGFR2 polymorphisms in susceptibility to the risk of breast cancer among North Indian women, we genotyped rs2981582, rs1219648, rs2981578 and rs7895676 polymorphisms in 368 breast cancer patients and 484 healthy controls by Polymerase chain reaction-Restriction fragment length polymorphism (PCR-RFLP assay. We observed a statistically significant association with breast cancer risk for all the four genetic variants (P<0.05. In per-allele model for rs2981582, rs1219648, rs7895676 and in dominant model for rs2981578, association remained significant after bonferroni correction (P<0.0125. On performing stratified analysis, significant correlations with various clinicopathological as well as environmental and lifestyle characteristics were observed. It was evident that rs1219648 and rs2981578 interacted with exogenous hormone use and advanced clinical stage III (after Bonferroni correction, P<0.000694, respectively. Furthermore, combined analysis on these four loci revealed that compared to women with 0-1 risk loci, those with 2-4 risk loci had increased risk (OR = 1.645, 95%CI = 1.152-2.347, P = 0.006. In haplotype analysis, for rs2981578, rs2981582 and rs1219648, risk haplotype (GTG was

  3. Sustained complete remission of human epidermal growth factor receptor 2-positive metastatic breast cancer in the liver during long-term trastuzumab (Herceptin maintenance therapy in a woman: a case report

    Directory of Open Access Journals (Sweden)

    Tsavaris Nicolas

    2010-12-01

    Full Text Available Abstract Introduction This case report and short review discusses how long trastuzumab should be continued in metastatic breast cancer, the safety issues in case of pregnancy and the risk of relapse with trastuzumab cessation. Case presentation We present the case of a 34-year-old Caucasian woman with human epidermal growth factor receptor 2-positive metastatic breast cancer in the liver who achieved prolonged complete remission within six months of receiving trastuzumab (Herceptin in combination with vinorelbine and gemcitabine. The patient remains in complete remission seven years later and continues to receive trastuzumab as maintenance therapy. Conclusion Trastuzumab-based therapies have greatly improved the survival rates of patients with human epidermal growth factor receptor 2- positive metastatic breast cancer. Despite such improvements, the safety of trastuzumab administration during pregnancy is yet to be defined.

  4. Gemcitabine Plus Docetaxel Versus Docetaxel in Patients With Predominantly Human Epidermal Growth Factor Receptor 2-Negative Locally Advanced or Metastatic Breast Cancer: A Randomized, Phase III Study by the Danish Breast Cancer Cooperative Group

    DEFF Research Database (Denmark)

    Nielsen, Dorte L; Bjerre, Karsten D; Jakobsen, Erik H;

    2011-01-01

    PURPOSE The objective of this phase III study was to compare the efficacy of gemcitabine plus docetaxel (GD) versus docetaxel in patients with advanced breast cancer. PATIENTS AND METHODS Predominantly human epidermal growth factor receptor 2 (HER2) -negative patients were randomly assigned to ge...... GD compared with docetaxel demonstrated increased TTP in metastatic breast cancer. However, RR and OS were similar. Thus, the addition of gemcitabine failed to demonstrate any clinically meaningful benefit when combined with docetaxel....

  5. Proliferation of neointimal smooth muscle cells after arterial injury. Dependence on interactions between fibroblast growth factor receptor-2 and fibroblast growth factor-9.

    Science.gov (United States)

    Agrotis, Alex; Kanellakis, Peter; Kostolias, Gina; Di Vitto, Giovanna; Wei, Chen; Hannan, Ross; Jennings, Garry; Bobik, Alex

    2004-10-01

    The growth factor signaling mechanisms responsible for neointimal smooth muscle cell (SMC) proliferation and accumulation, a characteristic feature of many vascular pathologies that can lead to restenosis after angioplasty, remain to be identified. Here, we examined the contribution of fibroblast growth factor receptors (FGFRs) 2 and 3 as well as novel fibroblast growth factors (FGFs) to such proliferation. Balloon catheter injury to the rat carotid artery stimulated the expression of two distinctly spliced FGFR-2 isoforms, differing only by the presence or absence of the acidic box, and two distinctly spliced FGFR-3 isoforms containing the acidic box and differing only by the presence of either the IIIb or IIIc exon. Post-injury arterial administration of recombinant adenoviruses expressing dominant negative mutant forms of these FGFRs were used to assess the roles of the endogenous FGFR isoforms in neointimal SMC proliferation. Dominant negative FGFR-2 containing the acidic box inhibited such proliferation by 40%, whereas the dominant negative FGFR-3 forms had little effect. Expression of FGF-9, known to be capable of binding to all four neointimal FGFR-2/-3 isoforms, was abundant within the neointima. FGF-9 markedly stimulated both the proliferation of neointimal SMCs and the activation of extracellular signal-related kinases 1/2, effects which were abrogated by the administration of antisense FGF-9 oligonucleotides to injured arteries and the expression of the dominant negative FGFR-2 adenovirus in cultured neointimal SMCs. These studies demonstrate that, although multiple FGFRs are induced in neointimal SMCs following arterial injury, specific interactions between distinctly spliced FGFR-2 isoforms and FGF-9 contribute to the proliferation of these SMCs.

  6. High blood sugar levels significantly impact the prognosis of colorectal cancer patients through down-regulation of microRNA-16 by targeting Myb and VEGFR2.

    Science.gov (United States)

    Yang, I-Ping; Tsai, Hsiang-Lin; Huang, Ching-Wen; Lu, Chien-Yu; Miao, Zhi-Feng; Chang, Se-Fen; Juo, Suh-Hang Hank; Wang, Jaw-Yuan

    2016-04-05

    The high prevalence of type 2 diabetes mellitus in colorectal cancer patients is a crucial public health issue worldwide. The deregulation of microRNAs has been shown to be associated with the progression of CRC; however, the effects of high blood sugar levels on miR deregulation and, in turn, CRC remain unexplored. In this study, 520 CRC patients were classified into two groups according to their blood sugar levels (≧110 or <110 mg/dL). Clinicopathologic features, clinical outcomes, and serum miR-16 levels of the two groups were then analyzed, while cell cycles, cell proliferation, migration, and cellular miR-16 expression were investigated via D-(+)-glucose administration. Additionally, the target genes of miR-16 were identified. Through multivariate analysis, both the disease-free survival and overall survival of the CRC patients were found to be associated with the UICC stage, perineural invasion, and blood glucose levels (P < 0.05). Serum miR-16 levels were significantly lower in the high blood glucose patients than in the normal blood glucose patients (P = 0.0329). With D-(+)-glucose administration, the proliferation and migration of CRC cells in vitro increased remarkably (P < 0.05), while their accumulation in the G1 phase decreased significantly. Cellular miR-16 expression was suppressed by D-(+)-glucose administration. The expression levels of two target genes, Myb and VEGFR2, were affected significantly by miR-16, while glucose administration inhibited miR-16 expression and enhanced tumor cell proliferation and migration. Hyperglycemia can impact the clinical outcomes of CRC patients, likely by inhibiting miR-16 expression and the expression of its downstream genes Myb and VEGFR2.

  7. Erythropoietin attenuates renal and pulmonary injury in polymicrobial induced-sepsis through EPO-R, VEGF and VEGF-R2 modulation.

    Science.gov (United States)

    Heitrich, Mauro; García, Daiana Maria de Los Ángeles; Stoyanoff, Tania Romina; Rodríguez, Juan Pablo; Todaro, Juan Santiago; Aguirre, María Victoria

    2016-08-01

    Sepsis remains the most important cause of acute kidney injury (AKI) and acute lung injury (ALI) in critically ill patients. The cecal ligation and puncture (CLP) model in experimental mice reproduces most of the clinical features of sepsis. Erythropoietin (EPO) is a well-known cytoprotective multifunctional hormone, which exerts anti-inflammatory, anti-oxidant, anti-apoptotic and pro-angiogenic effects in several tissues. The aim of this study was to evaluate the underlying mechanisms of EPO protection through the expression of the EPO/EPO receptor (EPO-R) and VEGF/VEF-R2 systems in kidneys and lungs of mice undergoing CLP-induced sepsis. Male inbred Balb/c mice were divided in three experimental groups: Sham, CLP, and CLP+EPO (3000IU/kg sc). Assessment of renal functional parameters, survival, histological examination, immunohistochemistry and/or Western blottings of EPO-R, VEGF and VEGF-R2 were performed at 18h post-surgery. Mice demonstrated AKI by elevation of serum creatinine and renal histologic damage. EPO treatment attenuates renal dysfunction and ameliorates kidney histopathologic changes. Additionally, EPO administration attenuates deleterious septic damage in renal cortex through the overexpression of EPO-R in tubular interstitial cells and the overexpression of the pair VEGF/VEGF-R2. Similarly CLP- induced ALI, as evidenced by parenchymal lung histopathologic alterations, was ameliorated through pulmonary EPO-R, VEGF and VEGF-R2 over expression suggesting and improvement in endothelial survival and functionality. This study demonstrates that EPO exerts protective effects in kidneys and lungs in mice with CLP-induced sepsis through the expression of EPO-R and the regulation of the VEGF/VEGF-R2 pair.

  8. Three Cases of Organized Hematoma of the Maxillary Sinus: Clinical Features and Immunohistological Studies for Vascular Endothelial Growth Factor and Vascular Endothelial Growth Factor Receptor 2 Expressions

    Directory of Open Access Journals (Sweden)

    Shoichiro Imayoshi

    2015-01-01

    Full Text Available Objectives. Organized hematoma (OH is a rare, nonneoplastic, hemorrhagic lesion causing mucosal swelling and bone thinning, mainly in the maxillary sinus. We aimed to clarify the clinical presentation and treatment of OH. Methods. Three cases of maxillary sinus OH and a literature review are presented. Results. Three men aged 16–40 years complained of nasal obstruction, frequent epistaxis, and/or headache. Clinical and radiological examinations revealed a maxillary sinus OH. They were cured in a piecemeal fashion via endoscopic middle meatal antrostomy. Furthermore, vascular endothelial growth factor and its receptor were expressed in the lesion. Conclusions. The pathogenesis of OH is unclear and it presents various histological and imaging findings; however, it is not difficult to rule out malignant tumors. Minimally invasive surgery such as endoscopic sinus surgery can cure it completely. Thus, it is important to determine the diagnosis using CT and MRI and to quickly provide surgical treatment.

  9. Relationship between cyclooxygenase-2 and human epidermal growth factor receptor 2 in vascular endothelial growth factor C up-regulation and lymphangiogenesis in human breast cancer.

    Science.gov (United States)

    Bhattacharjee, Rabindra N; Timoshenko, Alexander V; Cai, Jing; Lala, Peeyush K

    2010-09-01

    Both cyclooxygenase (COX)-2 and human epidermal growth factor receptor (HER)-2 promote breast cancer progression; however, the relationship between the two molecules remains unclear. We utilized human breast cancer tissues and cell lines to examine whether COX-2 and HER-2 played independent or interdependent roles in vascular endothelial growth factor (VEGF)-C up-regulation and lymphangiogenesis. A paired correlation of immunodetectable levels of COX-2, VEGF-C, and HER-2 proteins and lymphovascular density (LVD; D2-40-immunolabeled) in 55 breast cancer specimens revealed a positive correlation between COX-2 and HER-2 irrespective of clinicopathological status. However COX-2 alone positively correlated with LVD. In 10 independent specimens, mRNA levels showed a positive correlation between HER-2 and COX-2 or VEGF-C but not LYVE-1 (lymphovascular endothelial marker). These findings implicate COX-2, but not HER-2, in breast cancer-associated lymphangiogenesis. Manipulation of the COX-2 or HER-2 genes in breast cancer cell lines varying widely in COX-2 and HER-2 expression revealed a direct role of COX-2 and an indirect COX-2 dependent role of HER-2 in VEGF-C up-regulation: (i) high VEGF-C expression in high COX-2/low HER-2 expressing MDA-MB-231 cells was reduced by siRNA-mediated down-regulation of COX-2, but not HER-2; (ii) integration of HER-2 in these cells simultaneously up-regulated COX-2 protein as well as VEGF-C secretion; and (iii) low VEGF-C secretion by high HER-2/low COX-2 expressing SK-BR-3 cells was stimulated by COX-2 overexpression. These findings of the primary role of COX-2 and the COX-2-dependent role of HER-2, if any, in VEGF-C up-regulation and lymphangiogenesis suggest that COX-2 inhibitors may abrogate lymphatic metastasis in breast cancer irrespective of HER-2 status. © 2010 Japanese Cancer Association.

  10. Docosapentaenoic acid (22:5, n-3) suppressed tube-forming activity in endothelial cells induced by vascular endothelial growth factor.

    Science.gov (United States)

    Tsuji, Masako; Murota, Se-itsu; Morita, Ikuo

    2003-05-01

    It is generally accepted that n-3 polyunsaturated fatty acids have beneficial effects on vascular homeostasis. Among the several functions of endothelial cells, angiogenesis contributes to tumor growth, inflammation, and microangiopathy. We have already demonstrated that eicosapentaenoic acid (EPA, 20:5, n-3) suppressed angiogenesis. In this paper, we examined the effect of docosapentaenoic acid (DPA, 22:5, n-3), an elongated metabolite of EPA, on tube-forming activity in bovine aortic endothelial cells (BAE cells) incubated between type I collagen gels. The pretreatment of BAE cells with DPA suppressed tube-forming activity induced by vascular endothelial growth factor (VEGF). The effect of DPA was stronger than those of EPA and docosahexaenoic acid (22:6, n-3). The migrating activity of endothelial cells stimulated with VEGF was also suppressed by DPA pretreatment. The treatment of BAE cells with DPA caused the suppression of VEGF receptor-2 (VEGFR-2, the kinase insert domain-containing receptor, KDR) expression in both plastic dish and collagen gel cultures. These data indicate that DPA has a potent inhibitory effect on angiogenesis through the suppression of VEGFR-2 expression.

  11. The antitumor effect of tanshinone IIA on anti-proliferation and decreasing VEGF/VEGFR2 expression on the human non-small cell lung cancer A549 cell line

    Directory of Open Access Journals (Sweden)

    Jun Xie

    2015-11-01

    Full Text Available The effects of tanshinone IIA on the proliferation of the human non-small cell lung cancer cell line A549 and its possible mechanism on the VEGF/VEGFR signal pathway were investigated. The exploration of the interaction between tanshinone IIA and its target proteins provides a feasible platform for studying the anticancer mechanism of active components of herbs. The CCK-8 assay was used to evaluate the proliferative activity of A549 cells treated with tanshinone IIA (2.5−80 μmol/L for 24, 48 and 72 h, respectively. Flow cytometry was used for the detection of cell apoptosis and cell cycle perturbation. VEGF and VEGFR2 expression were studied by Western blotting. The binding mode of tanshinone IIA within the crystal structure of the VEGFR2 protein was evaluated with molecular docking analysis by use of the CDOCKER algorithm in Discovery Studio 2.1. The CCK-8 results showed that tanshinone IIA can significantly inhibit A549 cell proliferation in a dose- and time-dependent manner. Flow cytometry results showed that the apoptosis rate of tested group was higher than the vehicle control, and tanshinone IIA-treated cells accumulated at the S phase, which was higher than the vehicle control. Furthermore, the expression of VEGF and VEGFR2 was decreased in Western blot. Finally, molecular docking analysis revealed that tanshinone IIA could be stably docked into the kinase domain of VEGFR2 protein with its unique modes to form H-bonds with Cys917 and π–π stacking interactions with Val848. In conclusion, tanshinone IIA may suppress A549 proliferation, induce apoptosis and cell cycle arrest at the S phase. This drug may suppress angiogenesis by targeting the protein kinase domains of VEGF/VEGFR2.

  12. Role of HIF1A, VEGFA and VEGFR2 SNPs in the Susceptibility and Progression of COPD in a Spanish Population

    Science.gov (United States)

    Baz-Dávila, Rebeca; Espinoza-Jiménez, Adriana; Rodríguez-Pérez, María del Cristo; Zulueta, Javier; Varo, Nerea; Montejo, Ángela; Almeida-González, Delia; Aguirre-Jaime, Armando; Córdoba-Lanús, Elizabeth; Casanova, Ciro

    2016-01-01

    Hypoxia is involved in the development of chronic inflammatory processes. Under hypoxic conditions HIF1A, VEGF and VEGFR2 are expressed and mediate the course of the resultant disease. The aim of the present study was to define the associations between tSNPs in these genes and COPD susceptibility and progression in a Spanish cohort. The T alleles in rs3025020 and rs833070 SNPs (VEGFA gene) were less frequent in the group of COPD cases and were associated with a lower risk of developing the disease (OR = 0.60; 95% CI = 0. 39–0.93; p = 0.023 and OR = 0.60; 95% CI = 0.38–0.96; p = 0.034, respectively) under a dominant model of inheritance. The haplotype in which both SNPs presented the T allele confirmed the association found (OR = 0.02; 95% CI = 0.00 to 0.66; p = 0.03). Moreover, patients with COPD carrying the T allele in homozygosis in rs3025020 SNP showed higher lung function values and this association remained constant during 3 years of follow-up. In conclusion, T allele in rs833070 and rs3025020 may confer a protective effect to COPD susceptibility in a Spanish population and the association of the SNP rs3025020 with lung function may be suggesting a role for VEGF in the progression of the disease. PMID:27163696

  13. Small GTP-Binding Protein Rac Is an Essential Mediator of Vascular Endothelial Growth Factor-Induced Endothelial Fenestrations and Vascular Permeability

    DEFF Research Database (Denmark)

    Eriksson, A.; Cao, R.; Tritsaris, K.

    2003-01-01

    ), endothelial nitric oxide synthase (eNOS), and extracellular regulated kinase (Erk1/2). We further found that phosphatidylinositol-3-OH kinase (PI3K) acted upstream of Rac and Akt-eNOS in VEGF/VEGFR-2 signaling. Conclusions- Our findings indicate that the small GTP-binding protein Rac is a key component...... and vascular permeability but only partially inhibited angiogenesis. Studies on endothelial cell cultures further revealed that VEGF stimulated phosphorylation of VEGF receptor-2 (VEGFR-2), leading to activation of Rac as well as increased phosphorylation of phospholipase C (PLC ), protein kinase B (Akt...

  14. Polymorphisms in vascular endothelial growth factor receptor 2 are associated with better response rates to ranibizumab treatment in age-related macular degeneration

    NARCIS (Netherlands)

    Hermann, M.M.; Asten, F. van; Muether, P.S.; Smailhodzic, D.; Lichtner, P.; Hoyng, C.B.; Kirchhof, B.; Grefkes, C.; Hollander, A.I. den; Fauser, S.

    2014-01-01

    PURPOSE: Intravitreal anti-vascular endothelial growth factor (VEGF) injections are currently the standard treatment for neovascular age-related macular degeneration (AMD), but a broad range of response rates has been observed. We evaluated the association of single nucleotide polymorphisms (SNPs) i

  15. Vitreous inflammatory factors and serous retinal detachment in central retinal vein occlusion: a case control series

    Directory of Open Access Journals (Sweden)

    Noma Hidetaka

    2011-12-01

    Full Text Available Abstract Background This study investigated whether the vitreous fluid levels of soluble vascular endothelial growth factor receptor-2 (sVEGFR-2, pigment epithelium-derived factor (PEDF, and soluble intercellular adhesion molecule 1 (sICAM-1 were associated with the occurrence of serous retinal detachment (SRD in patients with central retinal vein occlusion (CRVO. Methods We recruited 33 patients with CRVO and macular edema, as well as 18 controls with nonischemic ocular diseases. Eighteen of the 33 patients with CRVO showed SRD on optical coherence tomography of the macula (defined as subretinal accumulation of fluid with low reflectivity, while the other 15 patients only had cystoid macular edema (CME, defined as hyporeflective intraretinal cavities. Retinal ischemia was evaluated by measuring the area of capillary non-perfusion using fluorescein angiography and the public domain Scion Image program, while central macular thickness (CMT was examined by optical coherence tomography. Vitreous fluid samples were obtained during pars plana vitrectomy and levels of the target molecules were measured by enzyme-linked immunosorbent assay. Results Ischemia was significantly more common in the SRD group (17/18 patients than in the CME group (5/15 patients (P ptrendptrend = 0.019. On the other hand, the vitreous fluid level of PEDF showed a significant decrease across the three groups (56.4 ± 40.0 ng/ml, 24.3 ± 17.3 ng/ml, and 16.4 ± 12.6 ng/ml, respectively, ptrend Conclusions Higher levels of inflammatory factors (sICAM-1 and sVEGFR-2 and lower levels of anti-inflammatory PEDF were observed in macular edema patients with SRD, suggesting that inflammation plays a key role in determining the severity of CRVO.

  16. Construction of anti-VEGFR-2 IgG1 like human antibody and its expression in CHO-k cells%抗VEGFR-2全人源IgG1抗体的构建及其在CHO-k细胞中的表达

    Institute of Scientific and Technical Information of China (English)

    李致科; 何远; 张娟; 解伟; 曹婉璐; 王泽根; 王旻

    2013-01-01

    本文在实验室构建的单链抗体-Fc融合抗体[scFv(AK404R)-Fc]的基础上构建抗VEGFR-2全人源IgG1样全长抗体(Mab-04).利用重叠PCR,获得Mab-04的轻链和重链的核酸序列后分别克隆到真核表达载体pcDNA3.1,获得重组质粒.脂质体法将重组质粒转染至CHO-k细胞,经ProteinA柱纯化细胞培养上清液获得目的蛋白,利用Western blotting检测目的蛋白,ELISA检测Mab-04与抗原亲和力.测序表明重组质粒构建成功,Westem blotting检测显示目的蛋白成功表达(1μg.mL-1),ELISA检测阐明该抗体能与抗原结合并呈浓度依赖性(IC50为50 nmol.L-1),表明Mab-04成功表达并正确装配,为进一步大量制备该抗体及其活性研究打下基础.

  17. The symbiotic bacterial surface factor polysaccharide A on Bacteroides fragilis inhibits IL-1β-induced inflammation in human fetal enterocytes via toll receptors 2 and 4

    Science.gov (United States)

    Jiang, Fei; Meng, Di; Weng, Meiqian; Zhu, Weishu; Wu, Wenxue; Kasper, Dennis; Walker, W. Allan

    2017-01-01

    Colonizing bacteria interacting with the immature, unlike the mature, human intestine favors inflammation over immune homeostasis. As a result, ten percent of premature infants under 1500 grams weight develop an inflammatory necrosis of the intestine after birth, e.g., necrotizing enterocolitis (NEC). NEC is a major health problem in this population causing extensive morbidity and mortality and an enormous expenditure of health care dollars. NEC can be prevented by giving preterm infants their mother’s expressed breast milk or ingesting selective probiotic organisms. Vaginally delivered, breast fed newborns develop health promoting bacteria (“pioneer” bacteria) which preferentially stimulate intestinal host defense and anti-inflammation. One such “pioneer” organism is Bacteroides fragilis with a polysaccharide (PSA) on its capsule. B. fragilis has been shown developmentally in intestinal lymphocytes and dendritic cells to produce a balanced T-helper cell (TH1/TH2) response and to reduce intestinal inflammation by activity through the TLR2 receptor stimulating IL-10 which inhibits IL-17 causing inflammation. No studies have been done on the role of B. fragilis PSA on fetal enterocytes and its increased inflammation. Accordingly, using human and mouse fetal intestinal models, we have shown that B. fragilis with PSA and PSA alone inhibits IL-1β-induced IL-8 inflammation in fetal and NEC intestine. We have also begun to define the mechanism for this unique inflammation noted in fetal intestine. We have shown that B. fragilis PSA anti-inflammation requires both the TLR2 and TLR4 receptor and is in part mediated by the AP1 transcription factor (TLR2) which is developmentally regulated. These observations may help to devise future preventative treatments of premature infants against NEC. PMID:28278201

  18. [Effect of 21-gene recurrence score on chemotherapy decisions for patients with estrogen receptor-positive, epidermal growth factor receptor 2-negative and lymph node-negative early stage-breast cancer].

    Science.gov (United States)

    Mao, Y; Chen, X S; Liang, Y; Wu, J Y; Huang, O; Zong, Y; Fang, Q; He, J R; Zhu, L; Chen, W G; Li, Y F; Lin, L; Fei, X C; Shen, K W

    2017-07-23

    Objective: To investigate the effect of 21-gene recurrence score on adjuvant chemotherapy decisions for patients with estrogen receptor (ER)-positive, epidermal growth factor receptor 2 (HER-2)-negative and lymph node (LN)-negative early stage-breast cancer. Methods: One hundred and forty-eight patients with ER+ , HER-2- and LN- early stage breast cancer were recruited in the Ruijin hospital, Shanghai Jiao Tong University School of Medicine. The 21-gene recurrence score (RS)assay was performed and systemic therapeutic decisions were made before and after knowing the RS results under multidisciplinary discussion. The effects of RS assay and the other influential factors on adjuvant chemotherapy decision were further analyzed. Results: After knowing the RS results, treatment decisions were changed in 26 out of 148 patients(17.6%). Among them, 9 out of 26 patients were not recommended for chemotherapy; 16 of 26 had treatment recommendation changed to chemotherapy, and chemotherapy regimen was changed in the last one patient. Multivariate analysis showed that RS, age and histological grade were independent factors of decision-making for adjuvant chemotherapy. Conclusion: Our results suggest that 21-gene recurrence score significantly influences decision making for adjuvant chemotherapy in patients with ER+ , HER-2- and LN- early stage breast cancer.

  19. Kinase RIP3 is dispensable for normal NF-kappa Bs, signaling by the B-cell and T-cell receptors, tumor necrosis factor receptor 1, and Toll-like receptors 2 and 4.

    Science.gov (United States)

    Newton, Kim; Sun, Xiaoqing; Dixit, Vishva M

    2004-02-01

    RIP3 is a member of the RIP kinase family. It is expressed in the embryo and in multiple adult tissues, including most hemopoietic cell lineages. Several studies have implicated RIP3 in the regulation of apoptosis and NF-kappa B signaling, but whether RIP3 promotes or attenuates activation of the NF-kappa B family of transcription factors has been controversial. We have generated RIP3-deficient mice by gene targeting and find RIP3 to be dispensable for normal mouse development. RIP3-deficient cells showed normal sensitivity to a variety of apoptotic stimuli and were indistinguishable from wild-type cells in their ability to activate NF-kappa B signaling in response to the following: human tumor necrosis factor (TNF), which selectively engages mouse TNF receptor 1; cross-linking of the B- or T-cell antigen receptors; peptidoglycan, which activates Toll-like receptor 2; and lipopolysaccharide (LPS), which stimulates Toll-like receptor 4. Consistent with these observations, RIP3-deficient mice exhibited normal antibody production after immunization with a T-dependent antigen and normal interleukin-1 beta (IL-1 beta), IL-6, and TNF production after LPS treatment. Thus, we can exclude RIP3 as an essential modulator of NF-kappa B signaling downstream of several receptor systems.

  20. The IIIb isoform of fibroblast growth factor receptor 2 is required for proper growth and branching of pancreatic ductal epithelium but not for differentiation of exocrine or endocrine cells.

    Science.gov (United States)

    Pulkkinen, Mari-Anne; Spencer-Dene, Bradley; Dickson, Clive; Otonkoski, Timo

    2003-02-01

    Fibroblast growth factors (Fgfs) and their receptors have been implicated in embryonic pancreas development. Recently it was shown that Fgf10, a major ligand for the IIIb isoform of fibroblast growth factor receptor 2 (Fgfr2b), has an important regulatory role in early pancreas development. The aim of our study was to define the role of Fgfr2b in pancreas development by analyzing the phenotype of Fgfr2b (-/-) mice. Pancreases of Fgfr2b (-/-) embryos were noticeably smaller than the wild type littermates during embryogenesis, and pancreatic ductal branching as well as duct cell proliferation was significantly reduced. However, both exocrine and endocrine pancreatic differentiation occurred relatively normally. Exogenous addition of Fgfr2b ligands (Fgf7 and Fgf10) stimulated duct cell proliferation and inhibited endocrine cell differentiation in the ex vivo embryonic organ cultures of wild type pancreas. Our results thus suggest that Fgfr2b-mediated signaling plays a major role in pancreatic ductal proliferation and branching morphogenesis, but has little effect on endocrine and exocrine differentiation.

  1. The effect of caveolin-1 on the expression of vascular endothelial growth factor receptor-2 in vascular endothelial growth factor-incubated osteosarcoma cells%小窝蛋白-1对血管内皮生长因子孵育的骨肉瘤细胞血管内皮生长因子受体-2表达水平的影响

    Institute of Scientific and Technical Information of China (English)

    何道辉; 赵杰才

    2011-01-01

    目的:研究小窝蛋白-1(caveolin-1)对血管内皮生长因子(VEGF)孵育的骨肉瘤细胞株(SOSP-9607)血管内皮生长因子受体-2(VEGFR-2)表达的影响,探讨其在骨肉瘤发展中作用的可能机制.方法:实验分为三组,即对照组、VEGF组、VEGF+caveolin-1 小片段干扰核糖核酸(siRNA)组.反转录聚合酶链式反应(RT-PCR)检测VEGF孵育的SOSP-9607细胞中caveolin-1、VEGFR-2信使核糖核酸 (mRNA)的表达;蛋白质印迹(Western Blot)检测caveolin-1、VEGFR-2蛋白的表达.结果:与对照组相比,VEGF组细胞caveolin-1、VEGFR-2 mRNA和蛋白表达明显增加(均P<0.01),VEGF+caveolin-1 siRNA组细胞caveolin-1 mRNA和蛋白表达减少,而VEGFR-2 mRNA表达增加,蛋白水平却表达减少,差异具有统计学意义(P<0.05).结论:caveolin-1能明显减少VEGF刺激下的骨肉瘤细胞中的VEGFR-2蛋白水平的表达,提示caveolin-1在VEGF依赖性信号级联反应中起正调控作用,为临床选择合适的靶点治疗骨肉瘤的血管生成提供实验依据.%Objective: To observe the effect of caveolin-1 on the expression of VEGFR-2 in VEGF-incubated osteosarco-ma cells and to explore the possible mechanism of its role on osteosarcoma development. Methods: There were three groups, control group, VEGF group, VEGF+caveolin-1 siRNA group. The expression of caveolin-1, VEGFR-2 mRNA and protein were detected with RT-PCR and Western Blot. Results: Compared with the control group, the expression of caveolin-1, VEGFR-2 significantly increased in VEGF group (all P<0.01). Compared with the control group, the expressions of mRNA and protein of caveolin-1 decreased, while the expression of mRNA of VEGFR-2 increased, and protein was reduced in VEGF+caveolin-1 siRNA group, there was a significant difference (P<0.05). Conclusion: caveolin-1 can significantly reduce the expression of VEGFR-2 in protein level in VEGF-stimulated osteosarcoma cells, suggesting that cave -olin-1 plays a positive regulatory role in VEGF

  2. beta-Tryptase up-regulates vascular endothelial growth factor expression via proteinase-activated receptor-2 and mitogen-activated protein kinase pathways in bone marrow stromal cells in acute myeloid leukemia.

    Science.gov (United States)

    Yang, Xiu-Peng; Li, Yan; Wang, Yazhu; Wang, Yue; Wang, Pingping

    2010-08-01

    Tryptases are predominantly mast cell-specific serine proteases with pleiotropic biological activities. Recently, significant amounts of tryptases have been shown to be produced by myeloblasts in certain patients with acute myeloid leukemia (AML), but the function of secreted tryptases in pathological circumstances remains unknown. In this study, we investigated whether beta-tryptase affects the expression of vascular endothelial growth factor (VEGF) in bone marrow stromal cells (BMSCs) in AML. We detected the expression of proteinase-activated receptor-2 (PAR-2) on AML BMSCs and found that beta-tryptase significantly up-regulated VEGF mRNA and protein expression in a dose-dependent manner by real-time PCR, Western blot, and ELISA. Furthermore, beta-tryptase increased ERK1/2 and p38MAPK phosphorylation, and pretreatment with FLLSY-NH(2), PD98059, and SB230580 (PAR-2, ERK1/2, and p38MAPK inhibitors, respectively) inhibited the beta-tryptase-induced production of VEGF. These results suggest that beta-tryptase up-regulates VEGF production in AML BMSCs via the PAR-2, ERK1/2, and p38MAPK signaling pathways.

  3. 抗痤疮药物与成纤维细胞生长因子受体2信号通路%Anti-acne agents and fibroblast growth factor receptor-2 signaling pathway

    Institute of Scientific and Technical Information of China (English)

    张倩; 周炳荣; 骆丹

    2011-01-01

    Fibroblast growth factor receptor-2 (FGFR2) signaling pathway has been proposed to be involved in acne pathogenesis. Many anti-acne agents act by downregulating the androgen-dependent fibroblast growth-FGFR2 signaling pathway, such as antiandrogen drugs, benzoyl peroxide, azelaic acid, tetracyclines, retinoids and erythromycin. Therefore, to recognize the FGFR2 signaling pathway may benefit future researches into the FGFR effect on sebaceous follicles and development of anti-acne agents.%研究发现,成纤维细胞生长因子受体2信号通路与痤疮发病机制有关,多种具有明确抗痤疮作用的药物均可通过同一机制,即下调雄激素依赖性成纤维细胞生长-成纤维细胞生长因子受体2信号通路发挥约效,这些药物包括抗雄激素类药物、过氧苯甲酰、壬二酸、四环素、维A酸类药物以及红霉素。因此,将为未来研究成纤维细胞生长因子受体对毛囊皮脂腺的作用和研究抗痤疮药物提出发展方向。

  4. Coagulation factor VIIa-mediated protease-activated receptor 2 activation leads to β-catenin accumulation via the AKT/GSK3β pathway and contributes to breast cancer progression.

    Science.gov (United States)

    Roy, Abhishek; Ansari, Shabbir A; Das, Kaushik; Prasad, Ramesh; Bhattacharya, Anindita; Mallik, Suman; Mukherjee, Ashis; Sen, Prosenjit

    2017-08-18

    Cell migration and invasion are very characteristic features of cancer cells that promote metastasis, which is one of the most common causes of mortality among cancer patients. Emerging evidence has shown that coagulation factors can directly mediate cancer-associated complications either by enhancing thrombus formation or by initiating various signaling events leading to metastatic cancer progression. It is well established that, apart from its distinct role in blood coagulation, coagulation factor FVIIa enhances aggressive behaviors of breast cancer cells, but the underlying signaling mechanisms still remain elusive. To this end, we investigated FVIIa's role in the migration and invasiveness of the breast cancer cell line MDA-MB-231. Consistent with previous observations, we observed that FVIIa increased the migratory and invasive potential of these cells. We also provide molecular evidence that protease-activated receptor 2 activation followed by PI3K-AKT activation and GSK3β inactivation is involved in these processes and that β-catenin, a well known tumor-regulatory protein, contributes to this signaling pathway. The pivotal role of β-catenin was further indicated by the up-regulation of its downstream targets cyclin D1, c-Myc, COX-2, MMP-7, MMP-14, and Claudin-1. β-Catenin knockdown almost completely attenuated the FVIIa-induced enhancement of breast cancer migration and invasion. These findings provide a new perspective to counteract the invasive behavior of breast cancer, indicating that blocking PI3K-AKT pathway-dependent β-catenin accumulation may represent a potential therapeutic approach to control breast cancer. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  5. 靶向超声微泡对结肠癌新生血管分子成像的实验研究%Molecular imaging of tumor angiogenesis with VEGFR2 targeting microbubbles in colon cancer bearing nude mice

    Institute of Scientific and Technical Information of China (English)

    位红芹; 何洁; 杨莉; 纪丽景; 张霞; 王冬晓; 文戈; 谷英士; 李颖嘉

    2013-01-01

    Objective To evaluate the effect of tumor neovascularization imaging in a nude mouse model of colon cancer by contrast ultrasound molecular imaging (UMI) of VEGF receptor 2 (kinase insert domain receptor,KDR).Methods Targeted microbubbles (MBt) were built by conjugating K237,a small peptide with high affinity for KDR,to liposome microbubbles through a biotin-avidin bridge.Control microbubbles (MBc) with control peptide were prepared by the same method.Nude mice models of LS174T human colon cancer were established.MBt and MBc were injected intravenously in twelve mice in random order with an interval of 30 min.MBt were injected in another six mice after K237-peptide blocking.UMI was performed in all mice at 5 min postinjection to observe the imaging difference and measure the video intensity (Ⅵ) of tumor tissues in different groups.One-way analysis of variance and the least significant difference t test were performed to analyze the difference of tumor VI in the groups with MBt,MBc and K237 blocking.Immunohistochemistry was applied to detect the expression and distribution of KDR in tumor tissue and adjacent tumor tissues.Results K237 peptide was successfully conjugated to the surface of microbubbles through biotin-avidin mediation.Ultrasound imaging signal of the tumor was high in the MBt group,while there were no significant enhancement in the groups of K237 blocking and MBc.The VI in MBt,MBc and K237 blocking groups was significantly different (F =39.130,P < 0.01).There was a significant difference of VI in the MBt group compared to the MBc group (30.18 ± 9.56 vs 8.28 ± 4.74,t =6.91,P <0.01).In the K237 blocking group Ⅵ was significantly lower than that in the MBt group (9.23 ± 3.44 vs 30.18 ± 9.56,t =4.91,P < 0.01).Immunohistochemistry results showed that KDR was highy expressed in tumor tissue.Conclusions KDR-targeting liposome contrast microbubbles may specifically and efficiently link to tumor vascular endothelial cells in vivo.Thus it may be

  6. Quantification of human epidermal growth factor receptor 2 immunohistochemistry using the Ventana Image Analysis System: correlation with gene amplification by fluorescence in situ hybridization: the importance of instrument validation for achieving high (>95%) concordance rate.

    Science.gov (United States)

    Dennis, Jake; Parsa, Rezvaneh; Chau, Donnie; Koduru, Prasad; Peng, Yan; Fang, Yisheng; Sarode, Venetia Rumnong

    2015-05-01

    The use of computer-based image analysis for scoring human epidermal growth factor receptor 2 (HER2) immunohistochemistry (IHC) has gained a lot of interest recently. We investigated the performance of the Ventana Image Analysis System (VIAS) in HER2 quantification by IHC and its correlation with fluorescence in situ hybridization (FISH). We specifically compared the 3+ IHC results using the manufacturer's machine score cutoffs versus laboratory-defined cutoffs with the FISH assay. Using the manufacturer's 3+ cutoff (VIAS score; 2.51 to 3.5), 181/536 (33.7%) were scored 3+, and FISH was positive in 147/181 (81.2%), 2 (1.1%) were equivocal, and 32 (17.6%) were FISH (-). Using the laboratory-defined 3+ cutoff (VIAS score 3.5), 52 (28.7%) cases were downgraded to 2+, of which 29 (55.7%) were FISH (-), and 23 (44.2%) were FISH (+). With the revised cutoff, there were improvements in the concordance rate from 89.1% to 97.0% and in the positive predictive value from 82.1% to 97.6%. The false-positive rate for 3+ decreased from 9.0% to 0.8%. Six of 175 (3.4%) IHC (-) cases were FISH (+). Three cases with a VIAS score 3.5 showed polysomy of chromosome 17. In conclusion, the VIAS may be a valuable tool for assisting pathologists in HER2 scoring; however, the positive cutoff defined by the manufacturer is associated with a high false-positive rate. This study highlights the importance of instrument validation/calibration to reduce false-positive results.

  7. Hyperbaric oxygen activates discoidin domain receptor 2 via tumour necrosis factor-alpha and the p38 MAPK pathway to increase vascular smooth muscle cell migration through matrix metalloproteinase 2.

    Science.gov (United States)

    Shyu, Kou-Gi; Wang, Bao-Wei; Chang, Hang

    2009-04-01

    DDR2 (discoidin domain receptor 2) regulates collagen turnover mediated by SMCs (smooth muscle cells) in atherosclerosis. HBO (hyperbaric oxygen) has been used in medical practice; however, the molecular mechanism of the beneficial effects of HBO is poorly understood. Furthermore, the effect of HBO on DDR2 has not been reported previously. In the present study, we investigated the cellular and molecular mechanisms of DDR2 regulation by HBO in VSMCs (vascular SMCs). Cells were exposed to 2.5 ATA (atmosphere absolute) of oxygen in a hyperbaric chamber. DDR2 protein (3.63-fold) and mRNA (2.34-fold) expression were significantly increased after exposure to 2.5 ATA HBO for 1 h. Addition of SB203580 and p38 MAPK (mitogen-activated protein kinase) siRNA (small interfering RNA) 30 min before HBO inhibited the induction of DDR2 protein. HBO also significantly increased DNA-protein binding activity of Myc/Max. Addition of SB203580 and an anti-TNF-alpha (tumour necrosis factor-alpha) monoclonal antibody 30 min before HBO abolished the DNA-protein binding activity induced by HBO. HBO significantly increased the secretion of TNF-alpha from cultured VSMCs. Exogenous addition of TNF-alpha significantly increased DDR2 protein expression, whereas anti-TNF-alpha and anti-(TNF-alpha receptor) antibodies blocked the induction of DDR2 protein expression. HBO significantly increased VSMC migration and proliferation, whereas DDR2 siRNA inhibited the migration induced by HBO. HBO increased activated MMP2 (matrix metalloproteinase 2) protein expression, and DDR2 siRNA abolished the induction of activated MMP2 expression induced by HBO. In conclusion, HBO activates DDR2 expression in cultured rat VSMCs. HBO-induced DDR2 is mediated by TNF-alpha and at least in part through the p38 MAPK and Myc pathways.

  8. The Neutrophil Response Induced by an Agonist for Free Fatty Acid Receptor 2 (GPR43) Is Primed by Tumor Necrosis Factor Alpha and by Receptor Uncoupling from the Cytoskeleton but Attenuated by Tissue Recruitment

    DEFF Research Database (Denmark)

    Björkman, Lena; Mårtensson, Jonas; Winther, Malene;

    2016-01-01

    Ligands with improved potency and selectivity for free fatty acid receptor 2 (FFA2R) have become available, and we here characterize the neutrophil responses induced by one such agonist (Cmp1) and one antagonist (CATPB). Cmp1 triggered an increase in the cytosolic concentration of Ca(2+), and the...

  9. Targeted microbubbles for imaging tumor angiogenesis: assessment of whole-body biodistribution with dynamic micro-PET in mice

    DEFF Research Database (Denmark)

    Willmann, Jürgen K; Cheng, Zhen; Davis, Corrine;

    2008-01-01

    To evaluate in vivo whole-body biodistribution of microbubbles (MBs) targeted to tumor angiogenesis-related vascular endothelial growth factor (VEGF) receptor 2 (VEGFR2) by using dynamic micro-positron emission tomography (PET) in living mice....

  10. Human epidermal growth factor receptor 2-positive breast cancer: heat shock protein 90 overexpression, Ki67 proliferative index, and topoisomerase II-α co-amplification as predictors of pathologic complete response to neoadjuvant chemotherapy with trastuzumab and docetaxel.

    Science.gov (United States)

    Bria, Emilio; Furlanetto, Jenny; Carbognin, Luisa; Brunelli, Matteo; Caliolo, Chiara; Nortilli, Rolando; Massari, Francesco; Pedron, Serena; Manfrin, Erminia; Pellini, Francesca; Bonetti, Franco; Sperduti, Isabella; Pollini, Giovanni Paolo; Scarpa, Aldo; Tortora, Giampaolo

    2015-02-01

    The combination of trastuzumab and chemotherapy is currently considered the standard of care for patients with locally advanced/operable human epidermal growth factor receptor 2 (HER2)-positive breast cancer. The potential correlation between the pathologic complete response (pCR) and the overexpression of heat shock protein 90 (Hsp90), Ki67, and the amplification of topoisomerase II-α (TOPO2A) was investigated in a series of patients who received neoadjuvant treatment. HER2-amplified patients who received neoadjuvant trastuzumab-docetaxel were gathered. Baseline and postsurgical Hsp90 immunoscore, Ki67 proliferation index, and TOPO2A amplification were determined together with classic clinical-pathologic predictors and correlated with pCR and imaging data. A total of 24 patients were evaluated for response; pCR, clinical, and radiologic response were found in 4 patients (16.7%; 95% confidence interval [CI], 1.7-31.5), 9 patients (37.5%; 95% CI, 18.1-56.8), and 6 patients (25.0%; 95% CI, 7.6-42.3) patients, respectively. pCR was significantly higher in premenopausal (60.0% vs. 5.3%, P = .02) and negative hormonal receptor patients (50.0% vs. 5.6%, P = .03). A trend for patients with high Ki67 and TOPO2A/HER2 co-amplification was found (21.1% vs. none, P = .54; 50.0% vs. 12%, P = .16). pCR was significantly higher in patients with Hsp90 score 3+, in comparison with score 2+ and score 1+ (50.0% vs. 14.3% vs. none, P = .05). After treatment, a statistically significant lower Ki67 staining (30.0% vs. 17.5%, P = .005) and a trend for the decreased expression of high (score 3+) and moderate (score 2+) Hsp90 immunostaining (McNemar P = .25, Wilcoxon-Mann-Whitney P = .08) were found. Although underpowered, our data suggest that patients with HER2-positive breast cancer overexpressing Hsp90 should be investigated as a "newer" molecular subtype with a significantly higher chance of pCR when receiving anti-Her2 agents. Copyright © 2015 Elsevier Inc. All rights

  11. Trastuzumab Emtansine With or Without Pertuzumab Versus Trastuzumab Plus Taxane for Human Epidermal Growth Factor Receptor 2-Positive, Advanced Breast Cancer: Primary Results From the Phase III MARIANNE Study.

    Science.gov (United States)

    Perez, Edith A; Barrios, Carlos; Eiermann, Wolfgang; Toi, Masakazu; Im, Young-Hyuck; Conte, Pierfranco; Martin, Miguel; Pienkowski, Tadeusz; Pivot, Xavier; Burris, Howard; Petersen, Jennifer A; Stanzel, Sven; Strasak, Alexander; Patre, Monika; Ellis, Paul

    2017-01-10

    Purpose Trastuzumab and pertuzumab are human epidermal growth factor receptor 2 (HER2) -targeted monoclonal antibodies, and trastuzumab emtansine (T-DM1) is an antibody-drug conjugate that combines the properties of trastuzumab with the cytotoxic activity of DM1. T-DM1 demonstrated encouraging efficacy and safety in a phase II study of patients with previously untreated HER2-positive metastatic breast cancer. Combination T-DM1 and pertuzumab showed synergistic activity in cell culture models and had an acceptable safety profile in a phase Ib and II study. Methods In the MARIANNE study, 1,095 patients with centrally assessed, HER2-positive, advanced breast cancer and no prior therapy for advanced disease were randomly assigned 1:1:1 to control (trastuzumab plus taxane), T-DM1 plus placebo, hereafter T-DM1, or T-DM1 plus pertuzumab at standard doses. Primary end point was progression-free survival (PFS), as assessed by independent review. Results T-DM1 and T-DM1 plus pertuzumab showed noninferior PFS compared with trastuzumab plus taxane (median PFS: 13.7 months with trastuzumab plus taxane, 14.1 months with T-DM1, and 15.2 months with T-DM1 plus pertuzumab). Neither experimental arm showed PFS superiority to trastuzumab plus taxane. Response rate was 67.9% in patients who were treated with trastuzumab plus taxane, 59.7% with T-DM1, and 64.2% with T-DM1 plus pertuzumab; median response duration was 12.5 months, 20.7 months, and 21.2 months, respectively. The incidence of grade ≥ 3 adverse events was numerically higher in the control arm (54.1%) versus the T-DM1 arm (45.4%) and T-DM1 plus pertuzumab arm (46.2%). Numerically fewer patients discontinued treatment because of adverse events in the T-DM1 arms, and health-related quality of life was maintained for longer in the T-DM1 arms. Conclusion T-DM1 showed noninferior, but not superior, efficacy and better tolerability than did taxane plus trastuzumab for first-line treatment of HER2-positive, advanced breast

  12. Comparison of immunohistochemistry with fluorescence in situ hybridization in determining the human epidermal growth factor receptor 2 status of breast cancer specimens: a multicenter study of 3149 Chinese patients

    Institute of Scientific and Technical Information of China (English)

    Han Xiaohong; Shi Yuankai; Ma Li; Lyu Zheng; Yang Hongying; Yao Jiarui; Li Jian

    2014-01-01

    Background Accurate detection of human epidermal growth factor receptor 2 (HER2) expression and gene amplification is crucial for the application of HER2-specific therapy and for evaluating the response of patients with breast cancer.A uniform and standard procedure of immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) needs to be established for evaluating the HER2 status in breast cancer tissues for the treatment of patients with real HER2-positive tumors.The present multicenter study was aimed to examine the HER2 status in breast cancer specimens from Chinese patients using both IHC and FISH methods.Methods A multicenter study was performed on the HER2 status in 3 149 breast cancer specimens from different ethnic populations and areas in China by IHC and FISH assays.The potential association of HER2 status with demographic and clinical characteristics was analyzed.Results The positive rates for HER2 over-expression and HER2 amplification were 23.3% and 27.5% in this study,respectively.The concordance between IHC and FISH was 71.2% (K=0.494,P <0.001).Furthermore,72.9% of specimens with IHC 2+ were negative to FISH.The discordance rates among laboratories were from 5% to 28% for IHC and 1% to 16% for FISH.HER2 amplification was associated significantly with advanced tumor stage (Ⅲ or Ⅳ,P=0.002),large tumor size (>5 cm,P=0.002),moderate and poor histological grades (P <0.0001),post-menopause (P <0.0001),ER-PR-(P=0.002),and having >4 lymph nodes affected (P <0.0001) in this population.The positive rates of HER2 amplification in specimens from Man and Hui Chinese were significantly higher than that in other Chinese populations.There are slightly higher positive rates of HER2 expression and amplification in Chinese patients with breast cancer.Conclusion These findings may provide new insights into understanding the epidemiological features of HER2 expression and amplification,and may be valuable for clinical

  13. Stimulatory Effect of Vascular Endothelial Growth Factor on Proliferation and Migration of Porcine Trophectoderm Cells and Their Regulation by the Phosphatidylinositol-3-Kinase-AKT and Mitogen-Activated Protein Kinase Cell Signaling Pathways.

    Science.gov (United States)

    Jeong, Wooyoung; Kim, Jinyoung; Bazer, Fuller W; Song, Gwonhwa

    2014-03-01

    Vascular endothelial growth factor (VEGF), a potent stimulator for angiogenesis, is likely to regulate implantation by stimulating endometrial angiogenesis and vascular permeability. In addition to known angiogenetic effects, VEGF has been suggested to participate in development of the early embryo as a mediator of fetal-maternal dialogue. Current studies have determined VEGF in terms of its role in endometrial vascular events, but VEGF-induced effects on the peri-implantation conceptus (embryo and extraembryonic membranes) remains unknown. In the present study, endometrial VEGF, VEGF receptor-1 (VEGFR-1), and VEGF receptor-2 (VEGFR-2) mRNAs increased significantly during the peri-implantation period of pregnancy as compared to the estrous cycle. Expression of VEGF, VEGFR-1, and VEGFR-2 mRNAs was abundant in endometrial luminal and glandular epithelia, endothelial blood vessels, and scattered cells in the stroma and conceptus trophectoderm. In addition, porcine trophectoderm (pTr) cells treated with VEGF exhibited increased abundance of phosphorylated (p)-AKT1, p-ERK1/2, p-p70RSK, p-RPS6, and p-4EBP1 in a time-dependent manner. The addition of U0126, an inhibitor of ERK1/2, inhibited VEGF-induced ERK1/2 phosphorylation, but AKT1 phosphorylation was not affected. The addition of LY294002, a PI3K inhibitor, decreased VEGF-induced phosphorylation of ERK1/2 and AKT1. Furthermore, VEGF significantly stimulated proliferation and migration of pTr cells, but these effects were blocked by SB203580, U0126, rapamycin, and LY294002, which inhibit p38 MAPK, ERK1/2, mTOR, and PI3K, respectively. These results suggest that VEGF is critical to successful growth and development of pTr during early pregnancy and that VEGF-induced stimulatory effect is coordinately regulated by multiple cell signaling pathways, including PI3K-AKT1 and MAPK signaling pathways.

  14. Adenovirus-mediated gene transfer of placental growth factor to perivascular tissue induces angiogenesis via upregulation of the expression of endogenous vascular endothelial growth factor-A

    NARCIS (Netherlands)

    Roy, H; Bhardwaj, S; Babu, M; Jauhiainen, S; Herzig, KH; Bellu, AR; Haisma, HJ; Carmeliet, P; Alitalo, K; Yla-Herttuala, S

    2005-01-01

    Placental growth factor (PIGF) is a member of the vascular endothelial growth factor (VEGF) family that binds specifically to VEGF receptor (VEGFR)-1. However, the mechanism of PIGF- and VEGFR-1-mediated angiogenesis has remained unclear and some in vitro studies suggest that VEGF-A/VEGFR-2

  15. Fibroblast Growth Factor Receptor-2 Contributes to the Basic Fibroblast Growth Factor-Induced Neuronal Differentiation in Canine Bone Marrow Stromal Cells via Phosphoinositide 3-Kinase/Akt Signaling Pathway.

    Directory of Open Access Journals (Sweden)

    Rei Nakano

    Full Text Available Bone marrow stromal cells (BMSCs are considered as candidates for regenerative therapy and a useful model for studying neuronal differentiation. The role of basic fibroblast growth factor (bFGF in neuronal differentiation has been previously studied; however, the signaling pathway involved in this process remains poorly understood. In this study, we investigated the signaling pathway in the bFGF-induced neuronal differentiation of canine BMSCs. bFGF induced the mRNA expression of the neuron marker, microtubule associated protein-2 (MAP2 and the neuron-like morphological change in canine BMSCs. In the presence of inhibitors of fibroblast growth factor receptors (FGFR, phosphatidylinositol 3-kinase (PI3K and Akt, i.e., SU5402, LY294002, and MK2206, respectively, bFGF failed to induce the MAP2 mRNA expression and the neuron-like morphological change. bFGF induced Akt phosphorylation, but it was attenuated by the FGFR inhibitor SU5402 and the PI3K inhibitor LY294002. In canine BMSCs, expression of FGFR-1 and FGFR-2 was confirmed, but only FGFR-2 activation was detected by cross-linking and immunoprecipitation analysis. Small interfering RNA-mediated knockdown of FGFR-2 in canine BMSCs resulted in the attenuation of bFGF-induced Akt phosphorylation. These results suggest that the FGFR-2/PI3K/Akt signaling pathway is involved in the bFGF-induced neuronal differentiation of canine BMSCs.

  16. Immunolocalization of corticotropin-releasing factor (CRF) and corticotropin-releasing factor receptor 2 (CRF-R2) in the developing gut of the sea bass (Dicentrarchus labrax L.).

    Science.gov (United States)

    Mola, Lucrezia; Gambarelli, Andrea; Pederzoli, Aurora

    2011-05-01

    Our previous data indicated an important role for adrenocorticotropic (ACTH)-like molecules co-operating with macrophages to control the modifications in body homeostasis during the first period of the life of sea bass (up to 30 days post-hatching) before the lymphoid cells have reached complete maturation. The aim of the study was to determine the immunolocalization of corticotropin-releasing factor (CRF), which is a very important mediator of stress-related responses. Our data showed that immunostaining for CRF is localized already at 8 days after hatching in nerve fibers of the gastrointestinal tract wall from the pharynx to the anterior gut, when the larvae are still feeding on yolk. This pattern of immunolocalization appeared similar to that in 24-day-old larvae, but at this stage there were also large cells immunopositive to CRF located in the wall of the midgut and hindgut. Lipopolysaccharide (LPS) treatment, which is a known stimulator of stress hormone responses, did not modify the CRF immunostaining pattern, though it did affect the immunolocalization of the peripheral CRF receptor, i.e. CRF-R2. Immunolocalization of CRF-R2 appeared in nerve fibers of the gut wall in larvae fixed 1h after the end of lipopolysaccharide (LPS) treatment. The present results suggest that CRF plays important autocrine and/or paracrine roles in the early immune responses at the gut level in the larval stages of sea bass (Dicentrarchus labrax L.) as already proposed for ACTH. Moreover, our studies taken together with other research on fish, in comparison with mammals, suggest a phylogenetically old role of CRF in immune-endocrine interactions.

  17. VEGF receptor-2 (Flk-1 overexpression in mice counteracts focal epileptic seizures.

    Directory of Open Access Journals (Sweden)

    Litsa Nikitidou

    Full Text Available Vascular endothelial growth factor (VEGF was first described as an angiogenic agent, but has recently also been shown to exert various neurotrophic and neuroprotective effects in the nervous system. These effects of VEGF are mainly mediated by its receptor, VEGFR-2, which is also referred to as the fetal liver kinase receptor 1 (Flk-1. VEGF is up-regulated in neurons and glial cells after epileptic seizures and counteracts seizure-induced neurodegeneration. In vitro, VEGF administration suppresses ictal and interictal epileptiform activity caused by AP4 and 0 Mg(2+ via Flk-1 receptor. We therefore explored whether increased VEGF signaling through Flk-1 overexpression may regulate epileptogenesis and ictogenesis in vivo. To this extent, we used transgenic mice overexpressing Flk-1 postnatally in neurons. Intriguingly, Flk-1 overexpressing mice were characterized by an elevated threshold for seizure induction and a decreased duration of focal afterdischarges, indicating anti-ictal action. On the other hand, the kindling progression in these mice was similar to wild-type controls. No significant effects on blood vessels or glia cells, as assessed by Glut1 and GFAP immunohistochemistry, were detected. These results suggest that increased VEGF signaling via overexpression of Flk-1 receptors may directly affect seizure activity even without altering angiogenesis. Thus, Flk-1 could be considered as a novel target for developing future gene therapy strategies against ictal epileptic activity.

  18. 具有血管内皮细胞生长因子受体-2酪氨酸激酶抑制作用的链霉菌次生代谢产物2754R的研究%Study of the secondary metabolite 2754R produced by streptomyces as inhibitor of VEGFR2-CD

    Institute of Scientific and Technical Information of China (English)

    蒋忠科; 张洋; 郭连宏; 姜蓉; 孙承航

    2014-01-01

    Objective To discover antagonists of VEGFR2-CD from the fermentation broth produced by streptomyces strain I06A-02754. Methods Under guidance of ELISA assay against VEGFR2-CD, compound 2754R was isolated and purified by combination of different column chromatographies and HPLC. The structure of compound 2754R was identified by combination of analysis of UV, IR, HR-ESI-MS and 1D-NMR, 2D-NMR. The cytotoxicity of compound 2754R was tested by MTT assay. Results Compound 2754R was purified and structurally identified as Juglomycin group antibiotics, and was the same with Juglomycin D. Compound 2754R showed weak antagonistic activity against VEGFR2-CD by ELISA assay, but did not show obvious cytotoxicity on HepG2 (human hepatocellular carcinoma), BEL-7402 (human hepatocellular carcinoma) and MCF-7 (human breast cancer) cell lines at 10μmol/L. Conclusion It is firstly reported compound 2754R (Juglomycin D) has antagonistic activity against VEGFR2-CD.%目的分离鉴定链霉菌 I06A-02754发酵液中具血管内皮生长因子受体-2酪氨酸激酶(VEGFR2-CD)抑制活性的强极性次生代谢产物。  方法采用大孔吸附树脂、阴离子交换树脂、MPLC、HPLC等分离手段对次生代谢产物进行分离纯化;通过 UV、IR、HR-ESI 质谱、1D-NMR 和2D-NMR 对其结构进行鉴定,以 ELISA 法检测其次生代谢产物对 VEGFR2-CD 的抑制活性;以 MTT 法检测化合物对肿瘤细胞的抑制活性。  结果从发酵液的水溶性部分分离得到一个极性较大的胡桃霉素类次生代谢产物--2754R;其化学结构与胡桃霉素D 一致,对 VEGFR2-CD 表现出一定的抑制活性;MTT 实验显示化合物2754R 对 HepG2细胞、MCF-7细胞和BEL-7402细胞没有明显的抑制活性(IC50>10μmol/L)。  结论化合物2754R 是具有 VEGFR2-CD 活性的胡桃霉素类次生代谢产物。

  19. Vascular endothelial growth factor (VEGF-C - a potent risk factor in children diagnosed with stadium 4 neuroblastoma.

    Directory of Open Access Journals (Sweden)

    Bogdan Miskowiak

    2009-01-01

    Full Text Available To evaluate the immunohistochemical expression of VEGF-C, CD34 and VEGFR-2 in cancer tissue of children diagnosed with stadium 4 neuroblastoma (NB and correlate their presence with the survival rate of children diagnosed with that stage of the disease. Eighteen children assigned to stadium 4 composed the study group. Fourteen patients (allocated to stadium 3 formed a control group. VEGF-C, CD34 and VEGFR-2 expressions were evaluated by immunohistochemical assay. Consecutive slides incubated with anti-CD34 and anti-VEGFR-2 antibodies revealed that the two markers were colocalized within endothelial layer of the blood vessels. On the other hand, VEGF-C was expressed exclusively in tumour cells. As demonstrated by Fisher's exact test, the risk of NB treatment failure (progression or relapse as well as tumour related death, when all the patients were considered, was found to be significant in VEGF-C positive patients. VEGF-C expression in NB constitutes a potent risk factor and may direct future anti-angiogenic treatment strategy. The proximity of VEGF-C and CD34/VEGFR-2 of NB could be the equivalent of a potentially interesting VEGF-C fashion involving a tumour cell invasion into the blood vessels in an early phase of metastases promoting.

  20. Vascular endothelial growth factor is important for brown adipose tissue development and maintenance.

    Science.gov (United States)

    Bagchi, Mandrita; Kim, Leo A; Boucher, Jeremie; Walshe, Tony E; Kahn, C Ronald; D'Amore, Patricia A

    2013-08-01

    Vascular endothelial growth factor (VEGF) is critical for angiogenesis, but also has pleiotropic effects on several nonvascular cells. Our aim was to investigate the role of VEGF in brown adipose tissue (BAT). We show that VEGF expression increases 2.5-fold during differentiation of cultured murine brown adipocytes and that VEGF receptor-2 is phosphorylated, indicating VEGF signaling. VEGF increased proliferation in brown preadipocytes in vitro by 70%, and blockade of VEGF signaling using anti-VEGFR2 antibody DC101 increased brown adipocyte apoptosis, as determined by cell number and activation of caspase 3. Systemic VEGF neutralization in mice, accomplished by adenoviral expression of soluble Flt1, resulted in 7-fold increase in brown adipocyte apoptosis, mitochondrial degeneration, and increased mitophagy compared to control mice expressing a null adenovirus. Absence of the heparan sulfate-binding VEGF isoforms, VEGF164 and VEGF188, resulted in abnormal BAT development in mice at E15.5, with fewer brown adipocytes and lower mitochondrial protein compared to wild-type littermates. These results suggest a role for VEGF in brown adipocytes and preadipocytes to promote survival, proliferation, and normal mitochondria and development.

  1. Expression and significance of basic fibroblast growth factor and fibroblast growth factor receptor - 2 in gastric cancer%碱性成纤维细胞生长因子及其受体在胃癌及癌前病变中的表达及其意义

    Institute of Scientific and Technical Information of China (English)

    王菲; 张庆

    2010-01-01

    目的 探讨碱性成纤维细胞生长因子(basic fibroblast growth factor, bFGF)及成纤维细胞生长因子受体-2(fibroblast growth factor receptor-2, FGFR-2)在胃癌组织中的表达及其意义.方法 应用免疫组化SP法检测100例胃癌及癌旁组织,bFGF和FGFR-2的表达及两者之间的关系.结果 胃癌中bFGF和FGFR-2表达明显高于癌旁组织及正常组织(P<0.01),胃癌组织中bFGF、FGFR-2表达的水平与临床病理分期有关,中晚期胃癌bFGF及FGFR-2阳性率明显高于早期胃癌(P<0.05),胃癌组织中bFGF与FGFR-2表达呈正相关,随bFGF表达的增高FGFR-2表达亦增高(P<0.05) bFGF和FGFR-2在胃癌组织中表达明显增高可能与肿瘤的发生发展有关.

  2. Total saponins from Albizia julibrissin inhibit vascular endothelial growth factor-mediated angiogenesis in vitro and in vivo.

    Science.gov (United States)

    Cai, Weiwei; Li, Yue; Yi, Qingqing; Xie, Fengshan; Du, Bin; Feng, Lei; Qiu, Liying

    2015-05-01

    Dried stem bark from Albizia julibrissin (AJ) is a highly valued Traditional Chinese Medicine, which has been shown to suppress tumor growth and angiogenesis. Total saponins from AJ (TSAJ) are one of the most bioactive components of AJ extract. The present study evaluated the anti‑tumor and anti‑angiogenic effects of TSAJ in vitro and in vivo. The anti‑angiogenic activity of TSAJ was investigated by measuring the effects on vascular endothelial growth factor (VEGF)‑induced proliferation, migration and tube formation of Ea.hy926 endothelial cells in vitro. The expression levels of proteins associated with VEGF‑induced angiogenesis were determined by western blotting. Furthermore, in vivo Matrigel™ plug and H22 hepatoma tumor models were used to verify the anti‑angiogenic effects of TSAJ. The present study demonstrated that TSAJ significantly inhibited VEGF‑mediated endothelial cell proliferation, migration and tube formation of Ea.hy926 cells in vitro. The anti‑angiogenic effects of TSAJ were modulated by suppression of phosphorylated‑(p‑) focal adhesion kinase, p‑Akt, and p‑extracellular signal‑regulated kinase in the VEGF/VEGF receptor 2 (R2) signaling pathway. Furthermore, oral administration of TSAJ significantly inhibited tumor growth and tumor‑induced angiogenesis, as well as the formation of functional vessels, in the Matrigel™ plug model. These results suggest that TSAJ may be a potential anti‑angiogenic agent that targets the VEGF/VEGFR2 signaling pathway, and inhibits tumor‑induced angiogenesis.

  3. Antioxidant, DNA interaction, VEGFR2 kinase, topoisomerase I and in vitro cytotoxic activities of heteroleptic copper(II) complexes of tetrazolo[1,5-a]pyrimidines and diimines.

    Science.gov (United States)

    Haleel, A; Mahendiran, D; Veena, V; Sakthivel, N; Rahiman, A Kalilur

    2016-11-01

    A series of heteroleptic mononuclear copper(II) complexes of the type [Cu(L(1-3))(diimine)]ClO4 (1-6) containing three tetrazolo[1,5-a]pyrimidine core ligands, ethyl 5-methyl-7-(2-hydroxyphenyl)-4,7-dihydrotetrazolo[1,5-a]pyrimidine-6-carboxylate (HL(1)), ethyl 5-methyl-7-(4-diethylamino-2-hydroxyphenyl)-4,7-dihydrotetrazolo[1,5-a]pyrimidine-6-carboxylate (HL(2)) or ethyl 5-methyl-7-(2-hydroxy-4-nitrophenyl)-4,7-dihydrotetrazolo[1,5-a]pyrimidine-6-carboxylate (HL(3)), and two diimine coligands, 2,2'-bipyridyl (bpy) or 1,10-phenanthroline (phen) have been synthesized and characterized by spectral methods. The geometry of complexes have been determined with the help of electronic absorption and EPR splitting patterns, which suggest four coordinated square planar geometry around copper(II) ion. The lowering of HOMO-LUMO band gap value of complex 4 implies its higher biological activity compared to other complexes. Antioxidant studies revealed that the complexes possess considerable radical scavenging potency against DPPH. The binding studies of the complexes with calf thymus DNA (CT-DNA) revealed groove mode of binding, which was further supported by docking simulation. The complexes 3 and 4 strongly inhibit the topoisomerase I, and also strongly interact with VEGFR2 kinase receptor via π-π, σ-π and hydrogen bonding interaction. Gel electrophoresis experiments demonstrated the ability of the complexes to cleave plasmid DNA in the absence of activators. In vitro cytotoxic activities of the complexes were examined on three cancerous cell lines such as human lung (A549), cervical (HeLa) and colon (HCT-15), and two normal cells such as human embryonic kidney (HEK) and peripheral blood mononuclear cells (PBMCs). The live cell and fluorescent imaging of cancer cells were observed with acridine orange/ethidium bromide staining assay. All encouraging chemical and biological findings indicate that the complex 4 is a suitable candidate for drug target.

  4. Albendazole inhibits endothelial cell migration, tube formation, vasopermeability, VEGF receptor-2 expression and suppresses retinal neovascularization in ROP model of angiogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Pourgholami, Mohammad H., E-mail: mh.pourgholami@unsw.edu.au [University of New South Wales, Department of Surgery, St George Hospital (SESIAHS), Sydney (Australia); Khachigian, Levon M.; Fahmy, Roger G. [Centre for Vascular Research, The University of New South Wales, Department of Haematology, The Prince of Wales Hospital, Sydney (Australia); Badar, Samina; Wang, Lisa; Chu, Stephanie Wai Ling; Morris, David Lawson [University of New South Wales, Department of Surgery, St George Hospital (SESIAHS), Sydney (Australia)

    2010-07-09

    The angiogenic process begins with the cell proliferation and migration into the primary vascular network, and leads to vascularization of previously avascular tissues and organs as well to growth and remodeling of the initially homogeneous capillary plexus to form a new microcirculation. Additionally, an increase in microvascular permeability is a crucial step in angiogenesis. Vascular endothelial growth factor (VEGF) plays a central role in angiogenesis. We have previously reported that albendazole suppresses VEGF levels and inhibits malignant ascites formation, suggesting a possible effect on angiogenesis. This study was therefore designed to investigate the antiangiogenic effect of albendazole in non-cancerous models of angiogenesis. In vitro, treatment of human umbilical vein endothelial cells (HUVECs) with albendazole led to inhibition of tube formation, migration, permeability and down-regulation of the VEGF type 2 receptor (VEGFR-2). In vivo albendazole profoundly inhibited hyperoxia-induced retinal angiogenesis in mice. These results provide new insights into the antiangiogenic effects of albendazole.

  5. Relationship Between Quantitative Estrogen and Progesterone Receptor Expression and Human Epidermal Growth Factor Receptor 2 (HER-2) Status With Recurrence in the Arimidex, Tamoxifen, Alone or in Combination Trial

    National Research Council Canada - National Science Library

    Mitch Dowsett; Craig Allred; Jill Knox; Emma Quinn; Janine Salter; Chris Wale; Jack Cuzick; Joan Houghton; Norman Williams; Elizabeth Mallon; Hugh Bishop; Ian Ellis; Denis Larsimont; Hironobu Sasano; Pauline Carder; Antonio Llombart Cussac; Fiona Knox; Valerie Speirs; John Forbes; Aman Buzdar

    2008-01-01

    ...) expression and human epidermal growth factor 2 (HER-2) status with time to recurrence (TTR) in postmenopausal women with hormone receptor-positive primary breast cancer treated with anastrozole or tamoxifen as adjuvant therapy...

  6. Prognostic value of Ki67 and p53 in patients with estrogen receptor-positive and human epidermal growth factor receptor 2-negative breast cancer: Validation of the cut-off value of the Ki67 labeling index as a predictive factor

    Science.gov (United States)

    OHARA, MASAHIRO; MATSUURA, KAZUO; AKIMOTO, ETSUSHI; NOMA, MIDORI; DOI, MIHOKO; NISHIZAKA, TAKASHI; KAGAWA, NAOKI; ITAMOTO, TOSHIYUKI

    2016-01-01

    The aim of this study was to evaluate the significance of the Ki67 labeling index and p53 status as prognostic and predictive indicators of operable estrogen receptor (ER)-positive and human epidermal growth factor receptor 2 (HER2)-negative breast cancer. Among 697 consecutive patients with primary breast cancer who underwent curative surgery between 2002 and 2013, 308 patients with ER-positive and HER2-negative breast cancer were assessed. The results of the multivariate Cox analysis demonstrated that a high Ki67 labeling index was significantly associated with a short recurrence-free interval (RFI) (p=0.004) and was marginally associated with a worse overall survival (p=0.074). A positive p53 status was not associated with worse outcomes. To validate the cut-off values of the Ki67 labeling index for identifying patients who may benefit from additional chemotherapy, prognostic factors were investigated in breast cancer patients treated postoperatively with endocrine therapy alone. Analysis of receiver operating characteristic curves demonstrated that a Ki67 labeling index cut-off of 20.0% was optimal for predicting recurrence among patients who did not receive adjuvant chemotherapy. The 5-year RFIs for patients with Ki67 <20 and ≥20% were 97.2 and 86.6%, respectively (p=0.0244). A high Ki67 labeling index (≥20%) was significantly associated with large tumors (p<0.01), lymph node metastasis (p=0.0236) and positive p53 status (p<0.001). The univariate analysis demonstrated that Ki67 labeling index ≥20%, lymph node metastasis and progesterone receptor negativity were significant worse prognostic factors for RFI (p=0.0333, 0.0116 and 0.0573, respectively). The Ki67 labeling index was found to be a useful prognostic factor in patients with ER-positive and HER2-negative breast cancer and the cut-off values of the Ki67 labeling index for making a decision regarding adjuvant treatment were validated. PMID:27073684

  7. Chronic and non-healing wounds: The story of vascular endothelial growth factor.

    Science.gov (United States)

    Zhou, Kehua; Ma, Yan; Brogan, Michael S

    2015-10-01

    The pathophysiology of the chronicity and non-healing status of wounds remains unknown. This paper presents the following hypothesis: abnormal patterns of vascular endothelial growth factor receptors (VEGFRs) are the culprits of wound chronicity and non-healing. More specifically, for patients with poor circulation, the decreased VEGFR-2 level is the cause of poor wound healing; for patients with non-compromised circulation, for example, patients with concurrent chronic wounds and active autoimmune diseases, the increased VEGFR-1 level is related to the non-healing status of wounds. The hypothesis is supported by the following facts. VEGFR-1 is the main contributor for inflammation and VEGFR-2 facilitates angiogenesis; soluble VEGFR-1 (sVEGFR-1) inactivates both VEGFR-1 and VEGFR-2. Patients with auto-immune disease have abnormally increased VEGFR-1 and decreased sVEGFR. Wounds in patients with active autoimmune diseases have poor response to electric stimulation which facilitates chronic wound healing in patients without active autoimmune diseases via increasing vascular endothelial growth factor (VEGF) secretion. Patients with chronic wounds (including diabetic foot ulcers and venous leg ulcers) but no active autoimmune diseases have decreased VEGFR-2 levels. We thus believe that abnormal patterns of VEGFRs are the culprits of wound chronicity and non-healing. For wounds with compromised circulation, VEGFR-2 decrease contributes to its chronicity; whereas for wounds with non-compromised circulation, VEGFR-1 increase is the leading cause of the non-healing status of chronic wounds. Treatments and research in wound care should be tailored to target these changes based on circulation status of wounds. Complete elucidation of changes of VEGFRs in chronic and non-healing wounds will enhance our understandings in tissue healing and thus better our selection of appropriate treatments for chronic and non-healing wounds.

  8. TNFα modulates Fibroblast Growth Factor Receptor 2 gene expression through the pRB/E2F1 pathway: identification of a non-canonical E2F binding motif.

    Directory of Open Access Journals (Sweden)

    Sirio D'Amici

    Full Text Available Interactions between epithelium and mesenchyme during wound healing are not fully understood, but Fibroblast Growth Factors (FGFs and their receptors FGFRs are recognized as key elements. FGFR2 gene encodes for two splicing transcript variants, FGFR2-IIIb or Keratinocyte Growth Factor Receptor (KGFR and FGFR2-IIIc, which differ for tissue localization and ligand specificity. Proinflammatory cytokines play an essential role in the regulation of epithelial-mesenchymal interactions, and have been indicated to stimulate FGFs production. Here we demonstrated that upregulation of FGFR2 mRNA and protein expression is induced by the proinflammatory cytokines Tumor Necrosis Factor-α, Interleukin-1β and Interleukin 2. Furthermore, we found that TNFα determines FGFR2 transcriptional induction through activation of pRb, mediated by Raf and/or p38 pathways, and subsequent release of the transcription factor E2F1. Experiments based on FGFR2 promoter serial deletions and site-directed mutagenesis allowed us to identify a minimal responsive element that retains the capacity to be activated by E2F1. Computational analysis indicated that this element is a non-canonical E2F responsive motif. Thus far, the molecular mechanisms of FGFR2 upregulation during wound healing or in pathological events are not known. Our data suggest that FGFR2 expression can be modulated by local recruitment of inflammatory cytokines. Furthermore, since alterations in FGFR2 expression have been linked to the pathogenesis of certain human cancers, these findings could also provide elements for diagnosis and potential targets for novel therapeutic approaches.

  9. Identification of human somatostatin receptor 2 domains involved in internalization and signaling in QGP-1 pancreatic neuroendocrine tumor cell line.

    Science.gov (United States)

    Cambiaghi, Valeria; Vitali, Eleonora; Morone, Diego; Peverelli, Erika; Spada, Anna; Mantovani, Giovanna; Lania, Andrea Gerardo

    2016-07-12

    Somatostatin exerts inhibitory effects on hormone secretion and cell proliferation via five receptor subtypes (SST1-SST5), whose internalization is regulated by β-arrestins. The receptor domains involved in these effects have been only partially elucidated. The aim of the study is to characterize the molecular mechanism and determinants responsible for somatostatin receptor 2 internalization and signaling in pancreatic neuroendocrine QGP-1 cell line, focusing on the third intracellular loop and carboxyl terminal domains. We demonstrated that in cells transfected with somatostatin receptor 2 third intracellular loop mutant, no differences in β-arrestins recruitment and receptor internalization were observed after somatostatin receptor 2 activation in comparison with cells bearing wild-type somatostatin receptor 2. Conversely, the truncated somatostatin receptor 2 failed to recruit β-arrestins and to internalize after somatostatin receptor 2 agonist (BIM23120) incubation. Moreover, the inhibitory effect of BIM23120 on cell proliferation, cyclin D1 expression, P-ERK1/2 levels, apoptosis and vascular endothelial growth factor secretion was completely lost in cells transfected with either third intracellular loop or carboxyl terminal mutants. In conclusion, we demonstrated that somatostatin receptor 2 internalization requires intact carboxyl terminal while the effects of SS on cell proliferation, angiogenesis and apoptosis mediated by somatostatin receptor 2 need the integrity of both third intracellular loop and carboxyl terminal.

  10. Circulating levels of tumor necrosis factor-alpha receptor 2 are increased in heart failure with preserved ejection fraction relative to heart failure with reduced ejection fraction: evidence for a divergence in pathophysiology.

    Directory of Open Access Journals (Sweden)

    Brendan N Putko

    Full Text Available BACKGROUND: Various pathways have been implicated in the pathogenesis of heart failure (HF with preserved ejection fraction (HFPEF. Inflammation in response to comorbid conditions, such as hypertension and diabetes, may play a proportionally larger role in HFPEF as compared to HF with reduced ejection fraction (HFREF. METHODS AND RESULTS: This study investigated inflammation mediated by the tumor necrosis factor-alpha (TNFα axis in community-based cohorts of HFPEF patients (n = 100, HFREF patients (n = 100 and healthy controls (n = 50. Enzyme-linked immunosorbent assays were used to investigate levels of TNFα, its two receptors (TNFR1 and TNFR2, and a non-TNFα cytokine, interleukin-6 (IL-6, in plasma derived from peripheral blood samples. Plasma levels of TNFα and TNFR1 were significantly elevated in HFPEF relative to controls, while levels of TNFR2 were significantly higher in HFPEF than both controls and HFREF. TNFα, TNFR1 and TNFR2 were each significantly associated with at least two of the following: age, estimated glomerular filtration rate, hypertension, diabetes, smoking, peripheral vascular disease or history of atrial fibrillation. TNFR2 levels were also significantly associated with increasing grade of diastolic dysfunction and severity of symptoms in HFPEF. CONCLUSIONS: Inflammation mediated through TNFα and its receptors, TNFR1 and TNFR2, may represent an important component of a comorbidity-induced inflammatory response that partially drives the pathophysiology of HFPEF.

  11. Relationship between quantitative estrogen and progesterone receptor expression and human epidermal growth factor receptor 2 (HER-2) status with recurrence in the Arimidex, Tamoxifen, Alone or in Combination trial.

    Science.gov (United States)

    Dowsett, Mitch; Allred, Craig; Knox, Jill; Quinn, Emma; Salter, Janine; Wale, Chris; Cuzick, Jack; Houghton, Joan; Williams, Norman; Mallon, Elizabeth; Bishop, Hugh; Ellis, Ian; Larsimont, Denis; Sasano, Hironobu; Carder, Pauline; Cussac, Antonio Llombart; Knox, Fiona; Speirs, Valerie; Forbes, John; Buzdar, Aman

    2008-03-01

    To determine the relationship between quantitative estrogen-receptor (ER) and progesterone-receptor (PgR) expression and human epidermal growth factor 2 (HER-2) status with time to recurrence (TTR) in postmenopausal women with hormone receptor-positive primary breast cancer treated with anastrozole or tamoxifen as adjuvant therapy. Formalin-fixed, paraffin-embedded tumor blocks were retrospectively collected from patients in the monotherapy arms of the Arimidex, Tamoxifen Alone or in Combination (ATAC) trial and centrally tested for ER, PgR and HER-2. ER and PgR were scored using continuous scales and HER-2 was scored as 0 to 3+ with 2+ cases being analyzed by fluorescence in situ hybridization. Blocks were collected from 2,006 of 5,880 eligible patients. Tissue was assessable and ER and/or PgR positivity confirmed centrally in 1,782 cases. In these, TTR was longer for anastrozole than for tamoxifen by a similar extent to that in the overall trial. None of the three biomarkers identified a set of patients with differential benefit from anastrozole over tamoxifen. Patients with low ER, low PgR, and high HER-2 expression had a poorer prognosis with either drug. Only 2.6% of patients in the highest quartile of PgR experienced recurrence after 5 years, compared with 13.2% in the lowest quartile. Quantitative expression of ER and PgR and HER-2 status did not identify patients with differential relative benefit from anastrozole over tamoxifen: TTR was longer for anastrozole than for tamoxifen in all molecular subgroups. Low ER or PgR or high HER-2 expression are associated with a high risk of recurrence with either anastrozole or tamoxifen.

  12. Interleukin-1 Receptor 2 Keeps the Lid on Interleukin-1α

    OpenAIRE

    Di Paolo, Nelson C.; Shayakhmetov, Dmitry M.

    2013-01-01

    The molecular mechanisms that regulate functional activation of IL-1α remain elusive. In this issue of Immunity, Zheng et al. describe a molecular system implicating interleukin-1 receptor-2 (IL-1R2) as a principal cytosolic factor that controls functional IL-1α activation during necrosis.

  13. The Abnormal Methylation of Vascular Endothelial Cell Growth Factor Receptor-2(KDR) Gene in Infancy Hemangioma.%血管瘤血管内皮生长因子受体KDR基因异常甲基化的研究

    Institute of Scientific and Technical Information of China (English)

    杨恩; 刘铭; 彭强

    2012-01-01

    Objective To investigate the methylation status of vascular endothelial growth factor receptor ( VEGFR, KDR) gene in hemangioma, vascular malformation and normal skin tissues by establishing methylation sensitivity high resolution dissolve curve method ( MS-HRM). The role of genetic methylation in proliferating and regressing hemangiomas also will be discussed. Methods 48 different period hemangioma samples, 15 vascular abnormality samples, and 8 normal skin tissue samples were tested respectively. The DNA of samples were extracted, modificated with sulphite methylation. Then, the DNA of samples was purificated and recycled and prepared for test. The methylation levels of KDR in all samples were tested by the methylation sensitivity high resolution dissolve curve method ( MS-HRM) . Results KDR gene methylation were detected positively in 32 hemangioma specimens(66. 67% ) , including 21 proliferate hemangiomas samples (87. 50% ) and 11 involuting hemangiomas(45. 83%). There was significant difference between proliferate hemangiomas and involuting hemangiomas in KDR methylation(X 2= 9. 375 ,P < 0. 05 ) . The methylation positive rate of vascular malformation samples was 13. 33% ( ranged from 0% to 25% ). The methylation positive rate of normal wrapping skin tissues was 12.50 % ( ranged from 0% to 5% ). The methylation positive rate in hemangioma was significant higher than that in vascular malformation or normal wrapping skin tissue ( P < 0. 05 ) . Conclutions Abnormal methylation of KDR expressed in hemangioma which may be associated with hemangioma formation, hyperplasia and degradation.%目的 通过建立甲基化敏感性高分辨率溶解曲线法(MS-HRM),检测血管内皮生长因子VEGF受体KDR基因启动子区域在不同时期血管瘤、血管畸形及正常皮肤组织中的甲基化状态,初步探讨基因甲基化在血管瘤形成、增生、退化过程中的作用.方法选取不同时期血管瘤石蜡标本48例、血管畸形石蜡标本15例

  14. Phase II Study of Lapatinib in Combination With Trastuzumab in Patients With Human Epidermal Growth Factor Receptor 2–Positive Metastatic Breast Cancer: Clinical Outcomes and Predictive Value of Early [18F]Fluorodeoxyglucose Positron Emission Tomography Imaging (TBCRC 003)

    Science.gov (United States)

    Lin, Nancy U.; Guo, Hao; Yap, Jeffrey T.; Mayer, Ingrid A.; Falkson, Carla I.; Hobday, Timothy J.; Dees, E. Claire; Richardson, Andrea L.; Nanda, Rita; Rimawi, Mothaffar F.; Ryabin, Nicole; Najita, Julie S.; Barry, William T.; Arteaga, Carlos L.; Wolff, Antonio C.; Krop, Ian E.; Winer, Eric P.; Van den Abbeele, Annick D.

    2015-01-01

    Purpose Lapatinib plus trastuzumab improves outcomes relative to lapatinib alone in heavily pretreated, human epidermal growth factor receptor 2–positive metastatic breast cancer (MBC). We tested the combination in the earlier-line setting and explored the predictive value of [18F]fluorodeoxyglucose positron emission tomography ([18F]FDG-PET) for clinical outcomes. Patients and Methods Two cohorts were enrolled (cohort 1: no prior trastuzumab for MBC and ≥ 1 year from adjuvant trastuzumab, if given; cohort 2: one to two lines of chemotherapy including trastuzumab for MBC and/or recurrence < 1 year from adjuvant trastuzumab). The primary end point was objective response rate by RECIST v1.0; secondary end points included clinical benefit rate (complete response plus partial response plus stable disease ≥ 24 weeks) and progression-free survival. [18F]FDG-PET scans were acquired at baseline, week 1, and week 8. Associations between metabolic response and clinical outcomes were explored. Results Eighty-seven patients were registered (85 were evaluable for efficacy). The confirmed objective response rate was 50.0% (95% CI, 33.8% to 66.2%) in cohort 1 and 22.2% (95% CI, 11.3% to 37.3%) in cohort 2. Clinical benefit rate was 57.5% (95% CI, 40.9% to 73.0%) in cohort 1 and 40.0% (95% CI, 25.7% to 55.7%) in cohort 2. Median progression-free survival was 7.4 and 5.3 months, respectively. Lack of week-1 [18F]FDG-PET/computed tomography ([18F]FDG-PET/CT) response was associated with failure to achieve an objective response by RECIST (negative predictive value, 91% [95% CI, 74% to 100%] for cohort 1 and 91% [95% CI, 79% to 100%] for cohort 2). Conclusion Early use of lapatinib and trastuzumab is active in human epidermal growth factor receptor 2–positive MBC. Week-1 [18F]FDG-PET/CT may allow selection of patients who can be treated with targeted regimens and spared the toxicity of chemotherapy. PMID:26169615

  15. Fibroblast growth factor receptor 2 translocations in intrahepatic cholangiocarcinoma.

    Science.gov (United States)

    Graham, Rondell P; Barr Fritcher, Emily G; Pestova, Ekaterina; Schulz, John; Sitailo, Leonid A; Vasmatzis, George; Murphy, Stephen J; McWilliams, Robert R; Hart, Steven N; Halling, Kevin C; Roberts, Lewis R; Gores, Gregory J; Couch, Fergus J; Zhang, Lizhi; Borad, Mitesh J; Kipp, Benjamin R

    2014-08-01

    Patients with cholangiocarcinoma often present with locally advanced or metastatic disease. There is a need for effective therapeutic strategies for advanced stage cholangiocarcinoma. Recently, FGFR2 translocations have been identified as a potential target for tyrosine kinase inhibitor therapies. This study evaluated 152 cholangiocarcinomas and 4 intraductal papillary biliary neoplasms of the bile duct for presence of FGFR2 translocations by fluorescence in situ hybridization and characterized the clinicopathologic features of cases with FGFR2 translocations. Thirteen (10 women, 3 men; 8%) of 156 biliary tumors harbored FGFR2 translocations, including 12 intrahepatic cholangiocarcinomas (12/96; 13%) and 1 intraductal papillary neoplasm of the bile duct. Histologically, cholangiocarcinomas with FGFR2 translocations displayed prominent intraductal growth (62%) or anastomosing tubular glands with desmoplasia (38%). Immunohistochemically, the tumors with FGFR2 translocations frequently showed weak and patchy expression of CK19 (77%). Markers of the stem cell phenotype in cholangiocarcinoma, HepPar1 and CK20, were negative in all cases. The median cancer-specific survival for patients whose tumors harbored FGFR2 translocations was 123 months compared to 37 months for cases without FGFR2 translocations (P = .039). This study also assessed 100 cholangiocarcinomas for ERBB2 amplification and ROS1 translocations. Of the cases tested, 3% and 1% were positive for ERBB2 amplification and ROS1 translocation, respectively. These results confirm that FGFR2, ERRB2, and ROS1 alterations are potential therapeutic targets for intrahepatic cholangiocarcinoma.

  16. Human epidermal growth factor receptor 2 (HER2) immunoreactivity

    DEFF Research Database (Denmark)

    Rasmussen, Anne-Sofie Schrohl; Pedersen, Hans Christian; Jensen, Sussie Steen

    2011-01-01

    The availability of specific antibody-based test systems is essential to testing of HER2 protein expression. Here, we mapped epitopes recognized by three pharmacodiagnostic HER2 antibodies and investigated their specificity towards peptides and fusion proteins homologous to the intracellular doma...... domains of HER1, HER2, HER3 and HER4. The investigated antibodies were PATHWAY(®) HER2 (clone 4B5; Ventana Medical Systems Inc., Tucson, AZ, USA), HercepTest™ (Dako Denmark A/S, Glostrup, Denmark), and Oracle(®) HER2 (clone CB11; Leica Microsystems GmbH, Wetzlar, Germany)....

  17. Role of protein kinase C β and vascular endothelial growth factor receptor in malignant pleural mesothelioma: Therapeutic implications and the usefulness of Caenorhabditis elegans model organism

    Directory of Open Access Journals (Sweden)

    Sivakumar Loganathan

    2011-01-01

    Full Text Available Purpose: To examine the role of both protein kinase C (PKC-β and vascular endothelial growth factor receptor (VEGFR-2 in malignant pleural mesothelioma (MPM using respective inhibitors, enzastaurin and KRN633. Materials and Methods: MPM cell lines, control cells, and a variety of archived MPM tumor samples were used to determine the protein expression levels of PKC-β, VEGFR-2, VEGF, and p-AKT. Effects of enzastaurin and KRN633 on phosphorylation status of key signaling molecules and viability of the mesothelioma cells were determined. The common soil nematode, Caenorhabditis elegans, was treated with enzastaurin to determine its suitability to screen for highly potent kinase inhibitors. Results: PKC-β1, PKC-β2 and VEGFR-2/KDR were overexpressed in MPM cell lines and MPM tumor tissues. Enzastaurin treatment resulted in significant loss in viability of VEGF induced cell proliferation; however, the effect of KRN633 was much less. Enzastaurin also dramatically decreased the phosphorylation of PKC-β, its downstream target p-AKT, and surprisingly, the upstream VEGFR-2. The combination of the two drugs at best was additive and similar results were obtained with respect to cell viability. Treatment of C. elegans with enzastaurin resulted in clear phenotypic changes and the worms were hypermotile with abnormal pattern and shape of eggs, suggesting altered fecundity. Conclusions: PKC-β1 and VEGFR-2 are both excellent therapeutic targets in MPM. Enzastaurin was better at killing MPM cells than KRN633 and the combination lacked synergy. In addition, we show here that C. elegans can be used to screen for the next generation inhibitors as treatment with enzastaurin resulted in clear phenotypic changes that could be assayed.

  18. Expression of human epidermal growth factor receptor 2 in breast cancer and its correlation with tumor necrosis factor-α%乳腺癌中人类表皮生长因子受体-2的表达及其与肿瘤坏死因子-α的相关性研究

    Institute of Scientific and Technical Information of China (English)

    张蒂; 涂建成; 胡汉宁; 杨桂; 李晓改; 喻明霞

    2011-01-01

    目的 研究人类表皮生长因子受体-2(HER-2)在乳腺癌中的表达及其与肿瘤坏死因子-α(TNF-α)的相关性.方法 HER-2是武汉大学中南医院乳腺癌患者常规检测项目.我们采用免疫组化SABC法检测112例原发性乳腺癌组织中TNF-α的表达,分析HER-2在乳腺癌中的表达、HER-2与乳腺癌临床病理特征的关系以及HER-2和TNF-α的相关性.结果 (1)乳腺癌中HER-2的阳性表达率为35.71%(40/112),其中在97例浸润性导管癌中的阳性表达率为35.05%(34/97),在浸润性小叶癌中的阳性表达率为33.33%(2/6),在黏液腺癌中的阳性表达率为25.00%(1/4),在导管内癌中的阳性表达率为50.00%(2/4),1例小叶原位癌为HER-2阳性.HER-2在各类型乳腺癌中的差异无统计学意义(P>0.05).(2)HER-2在乳腺癌中的表达与TNM分期、年龄、初潮年龄、是否绝经、孕次、产次、肿瘤家族史均无相关性(P均>0.05).(3)HER-2阴性时TNF-α的阳性率为23.61%(17/72),HER-2阳性时TNF-α的阳性率为52.50%(21/40).HER-2和TNF-α在乳腺癌中的表达有显著正相关性(r=0.881,P<0.05).结论 HER-2与TNF-α在乳腺癌中的表达有显著正相关性,具体机制有待更多研究.%Objective To determine the expression of Human Epidermal Growth Factor Receptor 2 (HER-2) in breast cancer and its correlation with Tumor Necrosis Factor-α (TNF-α). Methods We used SABC method to detect the expression of HER-2 and TNF-α in 112 cases of primary breast cancer, and analyzed the association of HER-2 expression with clinicopathological features and TNF-α expression. Results The positive expression rate of HER-2 in breast cancer was 35.71% (40/112), of which, the expression rate was 35.05% (34/97) in 97 invasive tubic breast cancer, and 33.33% (2/6) in invasive lobular breast cancer,25.00% (1/4) in mucinous carcinoma, and 50. 00% (2/4) in intraductal carcinoma. There was no significant correlation between HER-2 and any clinicopathological features of

  19. Neuroprotective effect of exogenous vascular endothelial growth factor on rat spinal cord neurons in vitro hypoxia

    Institute of Scientific and Technical Information of China (English)

    DING Xin-min; MAO Bo-yong; JIANG Shu; LI Sheng-fu; DENG Yi-ling

    2005-01-01

    Background Vascular endothelial growth factor (VEGF) is well known as a hypoxia-induced protein. That it markedly increased expression of VEGF and improvement of rat motor function after spinal cord injury suggested that VEGF could play a neuroprotective role in ischaemic tolerance. This study investigated whether vascular endothelial growth factor has direct neuroprotective effects on rat spinal cord neurons. Methods We employed primary cultures of embryonic rat spinal cord neurons, then administrated different concentrations of VEGF164 in the culture medium before hypoxia when the number of neurons was counted and the cell viability was detected by MTT. The neuronal apoptosis and expression of VEGF and its receptor genes were evaluated by terminal deoxynucleotidyl transferase mediated dUTP nick-end labelling (TUNEL) and immunohistochemistry. The VEGFR2/FLK-1 inhibitor, SU1498, was used to confirm whether the neuroprotective effect of VEGF was mediated through VEGFR2/Flk-1 receptors. Result In hypoxic conditions,the number and viability of neurons decreased progressively, while the number of TUNEL-positive cells increased along with the prolongation of hypoxic exposure. When the concentration of VEGF in cell culture medium reached 25 ng/ml, the cell viability increased 11% and neuronal apoptosis reduced to half, this effect was dose dependent and led to an approximately 25% increase in cell viability and about threefold decrease in TUNEL-positive cells at a maximally effective concentration of 100 ng/ml. In normal conditions, VEGF/Flk-1 but not VEGF/Flt-1 gene expressed at a low level: after hypoxia, the expression of VEGF/Flk-1, but not VEGF/Flt-1 was significantly increased. The protective effect of VEGF was blocked by the VEGFR2/Flk-1 receptor tyrosine kinase inhibitor, SU1498. Conclusions VEGF has direct neuroprotective effects on rat spinal cord neurons, which may be mediated in vitro through VEGFR2/Flk-1 receptors.

  20. Discoidin Receptor 2 Controls Bone Formation and Marrow Adipogenesis.

    Science.gov (United States)

    Ge, Chunxi; Wang, Zhengyan; Zhao, Guisheng; Li, Binbin; Liao, Jinhui; Sun, Hanshi; Franceschi, Renny T

    2016-12-01

    Cell-extracellular matrix (ECM) interactions play major roles in controlling progenitor cell fate and differentiation. The receptor tyrosine kinase, discoidin domain receptor 2 (DDR2), is an important mediator of interactions between cells and fibrillar collagens. DDR2 signals through both ERK1/2 and p38 MAP kinase, which stimulate osteoblast differentiation and bone formation. Here we show that DDR2 is critical for skeletal development and differentiation of marrow progenitor cells to osteoblasts while suppressing marrow adipogenesis. Smallie mice (Ddr2(slie/slie) ), which contain a nonfunctional Ddr2 allele, have multiple skeletal defects. A progressive decrease in tibial trabecular bone volume/total volume (BV/TV) was observed when wild-type (WT), Ddr2(wt/slie) , and Ddr2(slie/slie) mice were compared. These changes were associated with reduced trabecular number (Tb.N) and trabecular thickness (Tb.Th) and increased trabecular spacing (Tb.Sp) in both males and females, but reduced cortical thickness only in Ddr2(slie/slie) females. Bone changes were attributed to decreased bone formation rather than increased osteoclast activity. Significantly, marrow fat and adipocyte-specific mRNA expression were significantly elevated in Ddr2(slie/slie) animals. Additional skeletal defects include widened calvarial sutures and reduced vertebral trabecular bone. To examine the role of DDR2 signaling in cell differentiation, bone marrow stromal cells (BMSCs) were grown under osteogenic and adipogenic conditions. Ddr2(slie/slie) cells exhibited defective osteoblast differentiation and accelerated adipogenesis. Changes in differentiation were related to activity of runt-related transcription factor 2 (RUNX2) and PPARγ, transcription factors that are both controlled by MAPK-dependent phosphorylation. Specifically, the defective osteoblast differentiation in calvarial cells from Ddr2(slie/slie) mice was associated with reduced ERK/MAP kinase and RUNX2-S319 phosphorylation and could

  1. Changes in growth factor expression in normal aging of the rat retina.

    Science.gov (United States)

    Smith, Christopher P; Steinle, Jena J

    2007-12-01

    Although much is known about the growth factor changes in ocular tissues during various diseases, little is known about normal aging of the retina. In order to further understand normal aging in the retina, we characterized age-related changes of growth factor expression in three different ages of rat retina. Real time PCR and protein analysis was conducted to investigate steady state mRNA expression and protein levels of VEGF, VEGFR2, PEDF, Ang-1, Tie-2, EphB4 and ephrinB2 in the retina of 8-, 22-, and 32-month-old Brown Norway X Fischer 344 F1 hybrid rats. An increase of VEGF protein levels was found at 32months compared to 8 and 22months of age. VEGFR2 protein was found to be increased at 22 and 32months compared to 8months. PEDF protein levels were reduced at 22 and 32months. Tie-2 levels were found to be significantly decreased by 32months compared to 8months of age, while ephrinB2 was found to be significantly lower at both 22 and 32months compared to 8months of age. The increases found in VEGF and its receptor VEGFR2, with the simultaneous decrease of PEDF protein levels, may stimulate an environment that is well suited for neovascularization in the normal aging retina. Overall, these results suggest that normal aging produces substantial changes in gene expression and protein levels.

  2. 中国人群FGFR2基因多态性与乳腺癌易感相关性研究的Meta分析%Fibroblast growth factor receptor 2 polymorphism and susceptibility to breast cancer in Chinese population:a Meta-analysis

    Institute of Scientific and Technical Information of China (English)

    邱秀娟; 成芳; 高俊

    2015-01-01

    OBJECTIVE To evaluate the association between the fibroblast growth factor receptor 2 (FGFR2) gene polymorphism (rs2981582,rs1219648,rs2420946) and the breast cancer risk in the Chinese populations.METHODS All studies published up to June 2014 on the association between three functional polymorphisms (rs2981582,rs1219648,rs2420946) in the promoter of FGFR2 gene and susceptibility to breast cancer in Chinese population were collected by searching PubMed,Embase,Cochrane library,CNKI,VIP,Wanfang and CBD database.The data were screened according to the inclusion and exclusion criteria,and extracted,and the quality of included studies was evaluated.The pooled odds ratios (OR) with 95 % confidence intervals (95 % CI) were calculated using Stata 12.0 software.Publication bias and sensitivity analysis were also assessed.RESULTS A total of 18 case-control studies involving 14568 cases and 12864 controls were included in the Meta-analysis.The FGFR2 rs2981582,rs1219648,rs2420946 polymorphisms were significantly associated with breast cancer risk susceptibility among Chinese populations.The subgroup analysis by region revealed that significant risks were found in southern and northern China populations for rs2981582 T allele(southern:OR=1.13,95 %CI:1.06-1.22,P =0.001 ; northern:OR =1.26,95% CI..1.06-1.49,P =0.008).Significant risks were found in southern China populations for rs2420946 T allele (OR=1.15,95 % CI:1.08-1.23,P<0.05),but not in northern China populations (OR=1.03,95 % CI:0.87-1.22,P =0.695).Significant risks were found in southern and northern China populations for rs1219648 G allele(southern:OR=1.19,95%CI:1.10-1.28,P<0.05; northern:OR=1.17,95%CI:1.00-1.37,P=0.05).CONCLUSION The FGFR2 rs2981582,rs1219648,rs2420946 polymorphisms are significantly associated with breast cancer risk susceptibility among Chinese populations.%目的 系统评估成纤维细胞生长因子受体2(fibroblast growth factor receptor 2,FGFR2)基因内含子的3

  3. A gene-protein assay for human epidermal growth factor receptor 2 (HER2: brightfield tricolor visualization of HER2 protein, the HER2 gene, and chromosome 17 centromere (CEN17 in formalin-fixed, paraffin-embedded breast cancer tissue sections

    Directory of Open Access Journals (Sweden)

    Nitta Hiroaki

    2012-05-01

    Full Text Available Abstract Background The eligibility of breast cancer patients for human epidermal growth factor receptor 2 (HER2-directed therapies is determined by the HER2 gene amplification and/or HER2 protein overexpression status of the breast tumor as determined by in situ hybridization (ISH or immunohistochemistry (IHC, respectively. Our objective was to combine the US Food and Drug Administration (FDA-approved HER2 & chromosome 17 centromere (CEN17 brightfield ISH (BISH and HER2 IHC assays into a single automated HER2 gene-protein assay allowing simultaneous detection of all three targets in a single tissue section. Methods The HER2 gene-protein assay was optimized using formalin-fixed, paraffin-embedded (FFPE samples of the xenograft tumors MCF7 [HER2 negative (non-amplified gene, protein negative] and Calu-3 [HER2 positive (amplified gene, protein positive]. HER2 IHC was performed using a rabbit monoclonal anti-HER2 antibody (clone 4B5 and a conventional 3,3'-diaminobenzidine IHC detection. The HER2 & CEN17 BISH signals were visualized using horseradish peroxidase-based silver and alkaline phosphatase-based red detection systems, respectively with a cocktail of 2,4-dinitrophenyl-labeled HER2 and digoxigenin-labeled CEN17 probes. The performance of the gene-protein assay on tissue microarray slides containing 189 randomly selected FFPE clinical breast cancer tissue cores was compared to that of the separate HER2 IHC and HER2 & CEN17 BISH assays. Results HER2 protein detection was optimal when the HER2 IHC protocol was used before (rather than after the BISH protocol. The sequential use of HER2 IHC and HER2 & CEN17 BISH detection steps on FFPE xenograft tumor sections appropriately co-localized the HER2 protein, HER2 gene, and CEN17 signals after mitigating the silver background staining by using a naphthol phosphate-containing hybridization buffer for the hybridization step. The HER2 protein and HER2 gene status obtained using the multiplex HER2 gene

  4. Anti-angiogenic activity of VXM01, an oral T-cell vaccine against VEGF receptor 2, in patients with advanced pancreatic cancer: A randomized, placebo-controlled, phase 1 trial.

    Science.gov (United States)

    Schmitz-Winnenthal, Friedrich H; Hohmann, Nicolas; Niethammer, Andreas G; Friedrich, Tobias; Lubenau, Heinz; Springer, Marco; Breiner, Klaus M; Mikus, Gerd; Weitz, Jürgen; Ulrich, Alexis; Buechler, Markus W; Pianka, Frank; Klaiber, Ulla; Diener, Markus; Leowardi, Christine; Schimmack, Simon; Sisic, Leila; Keller, Anne-Valerie; Koc, Ruhan; Springfeld, Christoph; Knebel, Philipp; Schmidt, Thomas; Ge, Yingzi; Bucur, Mariana; Stamova, Slava; Podola, Lilli; Haefeli, Walter E; Grenacher, Lars; Beckhove, Philipp

    2015-04-01

    VEGFR-2 is expressed on tumor vasculature and a target for anti-angiogenic intervention. VXM01 is a first in kind orally applied tumor vaccine based on live, attenuated Salmonella bacteria carrying an expression plasmid, encoding VEGFR-2. We here studied the safety, tolerability, T effector (Teff), T regulatory (Treg) and humoral responses to VEGFR2 and anti-angiogenic effects in advanced pancreatic cancer patients in a randomized, dose escalation phase I clinical trial. Results of the first 3 mo observation period are reported. Locally advanced or metastatic, pancreatic cancer patients were enrolled. In five escalating dose groups, 30 patients received VXM01 and 15 placebo on days 1, 3, 5, and 7. Treatment was well tolerated at all dose levels. No dose-limiting toxicities were observed. Salmonella excretion and salmonella-specific humoral immune responses occurred in the two highest dose groups. VEGFR2 specific Teff, but not Treg responses were overall increased in vaccinated patients. We furthermore observed a significant reduction of tumor perfusion after 38 d in vaccinated patients together with increased levels of serum biomarkers indicative of anti-angiogenic activity, VEGF-A, and collagen IV. Vaccine specific Teff responses significantly correlated with reductions of tumor perfusion and high levels of preexisting VEGFR2-specific Teff while those showing no antiangiogenic activity had low levels of preexisting VEGFR2 specific Teff, showed a transient early increase of VEGFR2-specific Treg and reduced levels of VEGFR2-specific Teff at later time points - pointing to the possibility that early anti-angiogenic activity might be based at least in part on specific reactivation of preexisting memory T cells.

  5. Activator of G-protein signaling 8 is involved in VEGF-mediated signal processing during angiogenesis.

    Science.gov (United States)

    Hayashi, Hisaki; Al Mamun, Abdullah; Sakima, Miho; Sato, Motohiko

    2016-03-15

    Activator of G-protein signaling 8 (AGS8, also known as FNDC1) is a receptor-independent accessory protein for the Gβγ subunit, which was isolated from rat heart subjected to repetitive transient ischemia with the substantial development of collaterals. Here, we report the role of AGS8 in vessel formation by endothelial cells. Knockdown of AGS8 by small interfering RNA (siRNA) inhibited vascular endothelial growth factor (VEGF)-induced tube formation, as well as VEGF-stimulated cell growth and migration. VEGF stimulated the phosphorylation of the VEGF receptor-2 (VEGFR-2, also known as KDR), ERK1/2 and p38 MAPK; however, knockdown of AGS8 inhibited these signaling events. Signal alterations by AGS8 siRNA were associated with a decrease of cell surface VEGFR-2 and an increase of VEGFR-2 in the cytosol. Endocytosis blockers did not influence the decrease of VEGFR-2 by AGS8 siRNA, suggesting the involvement of AGS8 in VEGFR-2 trafficking to the plasma membrane. VEGFR-2 formed a complex with AGS8 in cells, and a peptide designed to disrupt AGS8-Gβγ interaction inhibited VEGF-induced tube formation. These data suggest a potential role for AGS8-Gβγ in VEGF signal processing. AGS8 might play a key role in tissue adaptation by regulating angiogenic events.

  6. Dependence on phosphoinositide 3-kinase and RAS-RAF pathways drive the activity of RAF265, a novel RAF/VEGFR2 inhibitor, and RAD001 (Everolimus) in combination.

    Science.gov (United States)

    Mordant, Pierre; Loriot, Yohann; Leteur, Céline; Calderaro, Julien; Bourhis, Jean; Wislez, Marie; Soria, Jean-Charles; Deutsch, Eric

    2010-02-01

    Activation of phosphatidylinositol-3-kinase (PI3K)-AKT and Kirsten rat sarcoma viral oncogene homologue (KRAS) can induce cellular immortalization, proliferation, and resistance to anticancer therapeutics such as epidermal growth factor receptor inhibitors or chemotherapy. This study assessed the consequences of inhibiting these two pathways in tumor cells with activation of KRAS, PI3K-AKT, or both. We investigated whether the combination of a novel RAF/vascular endothelial growth factor receptor inhibitor, RAF265, with a mammalian target of rapamycin (mTOR) inhibitor, RAD001 (everolimus), could lead to enhanced antitumoral effects in vitro and in vivo. To address this question, we used cell lines with different status regarding KRAS, PIK3CA, and BRAF mutations, using immunoblotting to evaluate the inhibitors, and MTT and clonogenic assays for effects on cell viability and proliferation. Subcutaneous xenografts were used to assess the activity of the combination in vivo. RAD001 inhibited mTOR downstream signaling in all cell lines, whereas RAF265 inhibited RAF downstream signaling only in BRAF mutant cells. In vitro, addition of RAF265 to RAD001 led to decreased AKT, S6, and Eukaryotic translation initiation factor 4E binding protein 1 phosphorylation in HCT116 cells. In vitro and in vivo, RAD001 addition enhanced the antitumoral effect of RAF265 in HCT116 and H460 cells (both KRAS mut, PIK3CA mut); in contrast, the combination of RAF265 and RAD001 yielded no additional activity in A549 and MDAMB231 cells. The combination of RAF and mTOR inhibitors is effective for enhancing antitumoral effects in cells with deregulation of both RAS-RAF and PI3K, possibly through the cross-inhibition of 4E binding protein 1 and S6 protein.

  7. Biomarkers in tissue from patients with upper gastrointestinal cancers treated with erlotinib and bevacizumab

    DEFF Research Database (Denmark)

    Rohrberg, Kristoffer Staal; Pappot, Helle; Lassen, Ulrik

    2011-01-01

    not be recommended in an unselected population of patients with chemo-refractory UGI cancer. However, a subpopulation of patients did benefit from the therapy. In this prospectively planned biomarker study we investigated vascular endothelial growth factor A (VEGF-A), VEGF receptor 2 (VEGFR-2) and epidermal growth...

  8. 人表皮生长因子受体2靶向新型高分子超声造影剂的制备及体外寻靶实验研究%Reparation of human epithelial growth factor receptor 2-targeted polymer ultrasound contrast agents with liquid perfluorocarbons and in vitro experiment

    Institute of Scientific and Technical Information of China (English)

    柯青兰; 王志刚; 何子朋; 岳媛媛; 李攀; 宋卫香

    2014-01-01

    Objective To prepare a novel extravascular human epithelial growth factor receptor 2 (HER2)-targeted polylactic-co-glycolic acid (PLGA)-COOH ultrasound contrast agent with liquid perfluorocarbons(PFH-PLGA-tra),and to observe it's general properties and it's effects on ultrasound imaging in vitro.Methods Polymeric nanocapsules of liquid perfluorocarbons were prepared by the single emulsion technique and conjugated with trastuzumab monoclonal antibody by EDC/NHS.The general characteristics were observed.The conjugation was demonstrated by immunofluorescence and the targeting performance of the agent was checked in human MCF-7 cells line in vitro.The encapsulation of liquid fluorocarbons was detected by heating in vitro.The effects on ultrasound imaging were observed in vitro.Results The mean diameter of agents was (261 ± 28)nm.The targeted nanocapsules were positive in immunofluorescence.In the targeted study,it was shown that a number of targeted nanocapsules conjugated with MCF-7 cells in vitro.Droplet-to-bubble transition experiment in vitro showed that there were no nano/microbubbles formed by heating in control groups at 80℃,while there were a lot of nano/microbubbles appeared in nanocapsules formulations at 80 ℃.The agents presented a good ultrasound imaging in vitro.Conclusions The HER2-targeted polymeric nanocapsules of liquid perfluorocarbons are successfully prepared,which may become a novel extravascular targeted ultrasound contrast agents.%目的 制备一种新型血管外靶向超声造影剂——包裹液态氟碳的人表皮生长因子受体2(HER2)靶向高分子纳米球,并观察其体外寻靶、显影能力.方法 首先采用单乳化法制备包裹液态氟碳的高分子PLGA纳米球(PFH-PLGA),然后通过碳二亚胺法将靶向HER2的特异性抗体trastuzumab连接到纳米球表面,制成靶向纳米球(PFH-PLGA-tra);检测其一般表征;免疫荧光法检测trastuzumab与纳米球连接情况;体外寻靶实验观

  9. Potent, selective inhibitors of fibroblast growth factor receptor define fibroblast growth factor dependence in preclinical cancer models.

    Science.gov (United States)

    Squires, Matthew; Ward, George; Saxty, Gordan; Berdini, Valerio; Cleasby, Anne; King, Peter; Angibaud, Patrick; Perera, Tim; Fazal, Lynsey; Ross, Douglas; Jones, Charlotte Griffiths; Madin, Andrew; Benning, Rajdeep K; Vickerstaffe, Emma; O'Brien, Alistair; Frederickson, Martyn; Reader, Michael; Hamlett, Christopher; Batey, Michael A; Rich, Sharna; Carr, Maria; Miller, Darcey; Feltell, Ruth; Thiru, Abarna; Bethell, Susanne; Devine, Lindsay A; Graham, Brent L; Pike, Andrew; Cosme, Jose; Lewis, Edward J; Freyne, Eddy; Lyons, John; Irving, Julie; Murray, Christopher; Newell, David R; Thompson, Neil T

    2011-09-01

    We describe here the identification and characterization of 2 novel inhibitors of the fibroblast growth factor receptor (FGFR) family of receptor tyrosine kinases. The compounds exhibit selective inhibition of FGFR over the closely related VEGFR2 receptor in cell lines and in vivo. The pharmacologic profile of these inhibitors was defined using a panel of human tumor cell lines characterized for specific mutations, amplifications, or translocations known to activate one of the four FGFR receptor isoforms. This pharmacology defines a profile for inhibitors that are likely to be of use in clinical settings in disease types where FGFR is shown to play an important role.

  10. A Novel Role of Serotonin Receptor 2B Agonist as an Anti-Melanogenesis Agent

    Directory of Open Access Journals (Sweden)

    Eun Ju Oh

    2016-04-01

    Full Text Available BW723C86, a serotonin receptor 2B agonist, has been investigated as a potential therapeutic for various conditions such as anxiety, hyperphagia and hypertension. However, the functional role of BW723C86 against melanogenesis remains unclear. In this study, we investigate the effect of serotonin receptor 2B (5-HTR2B agonist on melanogenesis and elucidate the mechanism involved. BW723C86 reduced melanin synthesis and intracellular tyrosinase activity in melan-A cells and normal human melanocytes. The expression of melanogenesis-related proteins (tyrosinase, TRP-1 and TRP-2 and microphthalmia-associated transcription factor (MITF in melan-A cells decreased after BW723C86 treatment. The promoter activity of MITF was also reduced by BW723C86 treatment. The reduced level of MITF was associated with inhibition of protein kinase A (PKA and cAMP response element-binding protein (CREB activation by BW723C86 treatment. These results suggest that the serotonin agonist BW723C86 could be a potential therapeutic agent for skin hyperpigmentation disorders.

  11. Intracerebroventricular urocortin 3 counteracts central acyl ghrelin-induced hyperphagic and gastroprokinetic effects via CRF receptor 2 in rats

    Directory of Open Access Journals (Sweden)

    Yeh C

    2016-10-01

    Full Text Available Chun Yeh,1 Ching-Heng Ting,2 Ming-Luen Doong,3 Chin-Wen Chi,4,5 Shou-Dong Lee,1 Chih-Yen Chen6–8 1Division of Gastroenterology, Department of Internal Medicine, Cheng-Hsin General Hospital, 2Department of Pathology, Mackay Memorial Hospital, 3Institute of Physiology, 4Institute of Pharmacology, National Yang-Ming University School of Medicine, 5Department of Medical Research, Taipei Veterans General Hospital, 6Division of Gastroenterology and Hepatology, Department of Medicine, Taipei Veterans General Hospital, 7Faculty of Medicine, National Yang-Ming University School of Medicine, Taipei, 8Taiwan Association for the Study of Small Intestinal Diseases, Guishan, Taiwan Purpose: Urocortin 3 is a key neuromodulator in the regulation of stress, anxiety, food intake, gut motility, and energy homeostasis, while ghrelin elicits feeding behavior and enhances gastric emptying, adiposity, and positive energy balance. However, the interplays between urocortin 3 and ghrelin on food intake and gastric emptying remain uninvestigated.Methods: We examined the differential effects of central O-n-octanoylated ghrelin, des-Gln14-ghrelin, and urocortin 3 on food intake, as well as on charcoal nonnutrient semiliquid gastric emptying in conscious rats that were chronically implanted with intracerebroventricular (ICV catheters. The functional importance of corticotropin-releasing factor (CRF receptor 2 in urocortin 3-induced responses was examined by ICV injection of the selective CRF receptor 2 antagonist, astressin2-B.Results: ICV infusion of urocortin 3 opposed central acyl ghrelin-elicited hyperphagia via CRF receptor 2 in satiated rats. ICV injection of O-n-octanoylated ghrelin and des-Gln14-ghrelin were equally potent in accelerating gastric emptying in fasted rats, whereas ICV administration of urocortin 3 delayed gastric emptying. In addition, ICV infusion of urocortin 3 counteracted central acyl ghrelin-induced gastroprokinetic effects via CRF receptor 2

  12. Structural and functional characterization of alternative transmembrane domain conformations in VEGF receptor 2 activation.

    Science.gov (United States)

    Manni, Sandro; Mineev, Konstantin S; Usmanova, Dinara; Lyukmanova, Ekaterina N; Shulepko, Mikhail A; Kirpichnikov, Mikhail P; Winter, Jonas; Matkovic, Milos; Deupi, Xavier; Arseniev, Alexander S; Ballmer-Hofer, Kurt

    2014-08-05

    Transmembrane signaling by receptor tyrosine kinases (RTKs) entails ligand-mediated dimerization and structural rearrangement of the extracellular domains. RTK activation also depends on the specific orientation of the transmembrane domain (TMD) helices, as suggested by pathogenic, constitutively active RTK mutants. Such mutant TMDs carry polar amino acids promoting stable transmembrane helix dimerization, which is essential for kinase activation. We investigated the effect of polar amino acids introduced into the TMD of vascular endothelial growth factor receptor 2, regulating blood vessel homeostasis. Two mutants showed constitutive kinase activity, suggesting that precise TMD orientation is mandatory for kinase activation. Nuclear magnetic resonance spectroscopy revealed that TMD helices in activated constructs were rotated by 180° relative to the interface of the wild-type conformation, confirming that ligand-mediated receptor activation indeed results from transmembrane helix rearrangement. A molecular dynamics simulation confirmed the transmembrane helix arrangement of wild-type and mutant TMDs revealed by nuclear magnetic resonance spectroscopy.

  13. Peptides identify multiple hotspots within the ligand binding domain of the TNF receptor 2

    Directory of Open Access Journals (Sweden)

    Lennick Michael

    2003-01-01

    Full Text Available Abstract Background Hotspots are defined as the minimal functional domains involved in protein:protein interactions and sufficient to induce a biological response. Results Here we describe the use of complex and high diversity phage display libraries to isolate peptides (called Hotspot Ligands or HSPLs which sub-divide the ligand binding domain of the tumor necrosis factor receptor 2 (TNFR2; p75 into multiple hotspots. We have shown that these libraries could generate HSPLs which not only subdivide hotspots on protein and non-protein targets but act as agonists or antagonists. Using this approach, we generated peptides which were specific for human TNFR2, could be competed by the natural ligands, TNFα and TNFβ and induced an unexpected biological response in a TNFR2-specific manner. Conclusions To our knowledge, this is the first report describing the dissection of the TNFR2 into biologically active hotspots with the concomitant identification of a novel and unexpected biological activity.

  14. Anthrax toxin receptor 2a controls mitotic spindle positioning.

    Science.gov (United States)

    Castanon, I; Abrami, L; Holtzer, L; Heisenberg, C P; van der Goot, F G; González-Gaitán, M

    2013-01-01

    Oriented mitosis is essential during tissue morphogenesis. The Wnt/planar cell polarity (Wnt/PCP) pathway orients mitosis in a number of developmental systems, including dorsal epiblast cell divisions along the animal-vegetal (A-V) axis during zebrafish gastrulation. How Wnt signalling orients the mitotic plane is, however, unknown. Here we show that, in dorsal epiblast cells, anthrax toxin receptor 2a (Antxr2a) accumulates in a polarized cortical cap, which is aligned with the embryonic A-V axis and forecasts the division plane. Filamentous actin (F-actin) also forms an A-V polarized cap, which depends on Wnt/PCP and its effectors RhoA and Rock2. Antxr2a is recruited to the cap by interacting with actin. Antxr2a also interacts with RhoA and together they activate the diaphanous-related formin zDia2. Mechanistically, Antxr2a functions as a Wnt-dependent polarized determinant, which, through the action of RhoA and zDia2, exerts torque on the spindle to align it with the A-V axis.

  15. Epigenetic regulation of the formyl peptide receptor 2 gene.

    Science.gov (United States)

    Simiele, Felice; Recchiuti, Antonio; Patruno, Sara; Plebani, Roberto; Pierdomenico, Anna Maria; Codagnone, Marilina; Romano, Mario

    2016-10-01

    Lipoxin (LX) A4, a main stop signal of inflammation, exerts potent bioactions by activating a specific G protein-coupled receptor, termed formyl peptide receptor 2 and recently renamed ALX/FPR2. Knowledge of the regulatory mechanisms that drive ALX/FPR2 gene expression is key for the development of innovative anti-inflammatory pharmacology. Here, we examined chromatin patterns of the ALX/FPR2 gene. We report that in MDA-MB231 breast cancer cells, the ALX/FPR2 gene undergoes epigenetic silencing characterized by low acetylation at lysine 27 and trimethylation at lysine 4, associated with high methylation at lysine 27 of histone 3. This pattern, which is consistent with transcriptionally inaccessible chromatin leading to low ALX/FPR2 mRNA and protein expression, is reversed in polymorphonuclear leukocytes that express high ALX/FPR2 levels. Activation of p300 histone acetyltransferase and inhibition of DNA methyltransferase restored chromatin accessibility and significantly increased ALX/FPR2 mRNA transcription and protein levels in MDA-MB231 cells, as well as in pulmonary artery endothelial cells. In both cells types, changes in the histone acetylation/methylation status enhanced ALX/FPR2 signaling in response to LXA4. Collectively, these results uncover unappreciated epigenetic regulation of ALX/FPR2 expression that can be exploited for innovative approaches to inflammatory disorders. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Circulating endothelial progenitor cells and depression: a possible novel link between heart and soul.

    Science.gov (United States)

    Dome, P; Teleki, Z; Rihmer, Z; Peter, L; Dobos, J; Kenessey, I; Tovari, J; Timar, J; Paku, S; Kovacs, G; Dome, B

    2009-05-01

    Although depression is known to be an independent risk factor for cardiovascular disorders, the mechanisms behind this connection are not well understood. However, the reduction in the number of endothelial progenitor cells (EPCs) in patients with cardiovascular risk factors has led us to hypothesize that depression influences the number of EPCs. EPCs labeled with CD34, CD133 and vascular endothelial growth factor receptor-2 (VEGFR2) antibodies were counted by flow cytometry in the peripheral blood (PB) of 33 patients with a current episode of major depression and of 16 control subjects. Mature (CD34+/VEGFR2+) and immature (CD133+/VEGFR2+) EPC counts were decreased in patients (vs controls; Pdepressive symptoms (Pquantitative RT-PCR approach, we measured CD34, CD133 and VEGFR2 mRNA levels of PB samples and found a net trend toward a decrease in all the investigated EPC-specific mRNA levels in patients as compared with controls. However, statistical significance was reached only for VEGFR2 and CD133 levels (Pdepression.

  17. Serum amyloid A1 isoforms display different efficacy at Toll-like receptor 2 and formyl peptide receptor 2.

    Science.gov (United States)

    Chen, Mingjie; Zhou, Huibing; Cheng, Ni; Qian, Feng; Ye, Richard D

    2014-12-01

    Serum amyloid A (SAA) is a major acute-phase protein and a precursor of amyloid A, the deposit of which leads to amyloidosis. Different alleles exist in SAA1, a predominant form of the human SAA gene family. Emerging evidence has shown correlations between these alleles and diseases including familiar Mediterranean fever and amyloidosis. However, it remains unclear how the proteins encoded by these SAA1 alleles act differently. Here we report the characterization of proteins encoded by SAA1.1, SAA1.3, and SAA1.5, in comparison to that encoded by SAA2.2, for their preference of the SAA receptors including formyl peptide receptor 2 (FPR2) and Toll-like receptor 2 (TLR2). SAA1.1 was more efficacious than SAA1.3 and SAA1.5 but equally efficacious to SAA2.2 in calcium mobilization and chemotaxis assays, which measure the activation of the G protein-coupled FPR2. In agreement with this, SAA1.1 and SAA2.2 induced more robust phosphorylation of ERK than SAA1.3 and SAA1.5. Only small differences were observed between the SAA1 proteins tested and SAA2.2 in TLR2-dependent NF-κB luciferase reporter assay. In comparison, SAA1.3 was most effective in stimulating ERK and p38 MAPK phosphorylation. Using bone marrow-derived macrophages from C57BL/10ScN (Tlr4lps-del) mice, we examined the SAA isoforms for their induction of selected pro- and anti-inflammatory cytokines. SAA1.3 was most potent in the induction of TNFα and IL-1rn, whereas SAA1.5 induced robust IL-10 expression. These results show differences of the SAA1 isoforms in their selectivity for the SAA receptors, which may affect their roles in modulating inflammation and immunity. Copyright © 2014 Elsevier GmbH. All rights reserved.

  18. Biased signaling by peptide agonists of protease activated receptor 2.

    Science.gov (United States)

    Jiang, Yuhong; Yau, Mei-Kwan; Kok, W Mei; Lim, Junxian; Wu, Kai-Chen; Liu, Ligong; Hill, Timothy A; Suen, Jacky Y; Fairlie, David P

    2017-02-07

    Protease activated receptor 2 (PAR2) is associated with metabolism, obesity, inflammatory, respiratory and gastrointestinal disorders, pain, cancer and other diseases. The extracellular N-terminus of PAR2 is a common target for multiple proteases, which cleave it at different sites to generate different N-termini that activate different PAR2-mediated intracellular signaling pathways. There are no synthetic PAR2 ligands that reproduce the same signaling profiles and potencies as proteases. Structure-activity relationships here for 26 compounds spanned a signaling bias over 3 log units, culminating in three small ligands as biased agonist tools for interrogating PAR2 functions. DF253 (2f-LAAAAI-NH2) triggered PAR2-mediated calcium release (EC50 2 μM) but not ERK1/2 phosphorylation (EC50 > 100 μM) in CHO cells transfected with hPAR2. AY77 (Isox-Cha-Chg-NH2) was a more potent calcium-biased agonist (EC50 40 nM, Ca2+; EC50 2 μM, ERK1/2), while its analogue AY254 (Isox-Cha-Chg-A-R-NH2) was an ERK-biased agonist (EC50 2 nM, ERK1/2; EC50 80 nM, Ca2+). Signaling bias led to different functional responses in human colorectal carcinoma cells (HT29). AY254, but not AY77 or DF253, attenuated cytokine-induced caspase 3/8 activation, promoted scratch-wound healing and induced IL-8 secretion, all via PAR2-ERK1/2 signaling. Different ligand components were responsible for different PAR2 signaling and functions, clues that can potentially lead to drugs that modulate different pathway-selective cellular and physiological responses.

  19. Selective Orthosteric Free Fatty Acid Receptor 2 (FFA2) Agonists

    Science.gov (United States)

    Schmidt, Johannes; Smith, Nicola J.; Christiansen, Elisabeth; Tikhonova, Irina G.; Grundmann, Manuel; Hudson, Brian D.; Ward, Richard J.; Drewke, Christel; Milligan, Graeme; Kostenis, Evi; Ulven, Trond

    2011-01-01

    Free fatty acid receptor 2 (FFA2; GPR43) is a G protein-coupled seven-transmembrane receptor for short-chain fatty acids (SCFAs) that is implicated in inflammatory and metabolic disorders. The SCFA propionate has close to optimal ligand efficiency for FFA2 and can hence be considered as highly potent given its size. Propionate, however, does not discriminate between FFA2 and the closely related receptor FFA3 (GPR41). To identify FFA2-selective ligands and understand the molecular basis for FFA2 selectivity, a targeted library of small carboxylic acids was examined using holistic, label-free dynamic mass redistribution technology for primary screening and the receptor-proximal G protein [35S]guanosine 5′-(3-O-thio)triphosphate activation, inositol phosphate, and cAMP accumulation assays for hit confirmation. Structure-activity relationship analysis allowed formulation of a general rule to predict selectivity for small carboxylic acids at the orthosteric binding site where ligands with substituted sp3-hybridized α-carbons preferentially activate FFA3, whereas ligands with sp2- or sp-hybridized α-carbons prefer FFA2. The orthosteric binding mode was verified by site-directed mutagenesis: replacement of orthosteric site arginine residues by alanine in FFA2 prevented ligand binding, and molecular modeling predicted the detailed mode of binding. Based on this, selective mutation of three residues to their non-conserved counterparts in FFA3 was sufficient to transfer FFA3 selectivity to FFA2. Thus, selective activation of FFA2 via the orthosteric site is achievable with rather small ligands, a finding with significant implications for the rational design of therapeutic compounds selectively targeting the SCFA receptors. PMID:21220428

  20. Cannabinoid receptor 2 signaling does not modulate atherogenesis in mice.

    Directory of Open Access Journals (Sweden)

    Florian Willecke

    Full Text Available BACKGROUND: Strong evidence supports a protective role of the cannabinoid receptor 2 (CB(2 in inflammation and atherosclerosis. However, direct proof of its involvement in lesion formation is lacking. Therefore, the present study aimed to characterize the role of the CB(2 receptor in Murine atherogenesis. METHODS AND FINDINGS: Low density lipoprotein receptor-deficient (LDLR(-/- mice subjected to intraperitoneal injections of the selective CB(2 receptor agonist JWH-133 or vehicle three times per week consumed high cholesterol diet (HCD for 16 weeks. Surprisingly, intimal lesion size did not differ between both groups in sections of the aortic roots and arches, suggesting that CB(2 activation does not modulate atherogenesis in vivo. Plaque content of lipids, macrophages, smooth muscle cells, T cells, and collagen were also similar between both groups. Moreover, CB(2 (-/-/LDLR(-/- mice developed lesions of similar size containing more macrophages and lipids but similar amounts of smooth muscle cells and collagen fibers compared with CB(2 (+/+/LDLR(-/- controls. While JWH-133 treatment reduced intraperitoneal macrophage accumulation in thioglycollate-elicited peritonitis, neither genetic deficiency nor pharmacologic activation of the CB(2 receptor altered inflammatory cytokine expression in vivo or inflammatory cell adhesion in the flow chamber in vitro. CONCLUSION: Our study demonstrates that both activation and deletion of the CB(2 receptor do not relevantly modulate atherogenesis in mice. Our data do not challenge the multiple reports involving CB(2 in other inflammatory processes. However, in the context of atherosclerosis, CB(2 does not appear to be a suitable therapeutic target for reduction of the atherosclerotic plaque.

  1. Rapid glutamate receptor 2 trafficking during retinal degeneration

    Directory of Open Access Journals (Sweden)

    Lin Yanhua

    2012-02-01

    Full Text Available Abstract Background Retinal degenerations, such as age-related macular degeneration (AMD and retinitis pigmentosa (RP, are characterized by photoreceptor loss and anomalous remodeling of the surviving retina that corrupts visual processing and poses a barrier to late-stage therapeutic interventions in particular. However, the molecular events associated with retinal remodeling remain largely unknown. Given our prior evidence of ionotropic glutamate receptor (iGluR reprogramming in retinal degenerations, we hypothesized that the edited glutamate receptor 2 (GluR2 subunit and its trafficking may be modulated in retinal degenerations. Results Adult albino Balb/C mice were exposed to intense light for 24 h to induce light-induced retinal degeneration (LIRD. We found that prior to the onset of photoreceptor loss, protein levels of GluR2 and related trafficking proteins, including glutamate receptor-interacting protein 1 (GRIP1 and postsynaptic density protein 95 (PSD-95, were rapidly increased. LIRD triggered neuritogenesis in photoreceptor survival regions, where GluR2 and its trafficking proteins were expressed in the anomalous dendrites. Immunoprecipitation analysis showed interaction between KIF3A and GRIP1 as well as PSD-95, suggesting that KIF3A may mediate transport of GluR2 and its trafficking proteins to the novel dendrites. However, in areas of photoreceptor loss, GluR2 along with its trafficking proteins nearly vanished in retracted retinal neurites. Conclusions All together, LIRD rapidly triggers GluR2 plasticity, which is a potential mechanism behind functionally phenotypic revisions of retinal neurons and neuritogenesis during retinal degenerations.

  2. Stimulation of cannabinoid receptor 2 (CB2 suppresses microglial activation

    Directory of Open Access Journals (Sweden)

    Fernandez Francisco

    2005-12-01

    Full Text Available Abstract Background Activated microglial cells have been implicated in a number of neurodegenerative disorders, including Alzheimer's disease (AD, multiple sclerosis (MS, and HIV dementia. It is well known that inflammatory mediators such as nitric oxide (NO, cytokines, and chemokines play an important role in microglial cell-associated neuron cell damage. Our previous studies have shown that CD40 signaling is involved in pathological activation of microglial cells. Many data reveal that cannabinoids mediate suppression of inflammation in vitro and in vivo through stimulation of cannabinoid receptor 2 (CB2. Methods In this study, we investigated the effects of a cannabinoid agonist on CD40 expression and function by cultured microglial cells activated by IFN-γ using RT-PCR, Western immunoblotting, flow cytometry, and anti-CB2 small interfering RNA (siRNA analyses. Furthermore, we examined if the stimulation of CB2 could modulate the capacity of microglial cells to phagocytise Aβ1–42 peptide using a phagocytosis assay. Results We found that the selective stimulation of cannabinoid receptor CB2 by JWH-015 suppressed IFN-γ-induced CD40 expression. In addition, this CB2 agonist markedly inhibited IFN-γ-induced phosphorylation of JAK/STAT1. Further, this stimulation was also able to suppress microglial TNF-α and nitric oxide production induced either by IFN-γ or Aβ peptide challenge in the presence of CD40 ligation. Finally, we showed that CB2 activation by JWH-015 markedly attenuated CD40-mediated inhibition of microglial phagocytosis of Aβ1–42 peptide. Taken together, these results provide mechanistic insight into beneficial effects provided by cannabinoid receptor CB2 modulation in neurodegenerative diseases, particularly AD.

  3. Association of VEGFR2 Gene+4422(AC)n Polymorphism with the Sensitivity to HiHiLo Training in Men of Han Nationality%中国北方汉族男性血管内皮生长因子受体2基因+4422(AC)n多态性与HiHiLo训练敏感性的关联研究

    Institute of Scientific and Technical Information of China (English)

    聂晶; 胡扬; 王景玲; 衣龙燕; 乌云格日勒

    2011-01-01

    目的:探讨中国北方汉族男性血管内皮生长因子受体2(VEGFR2)基因+4422(AC)n多态性与高住高练低训(HiHiLo)训练敏感性的关联.方法:选取71名中国北方平原地区汉族男子进行30天HiHiLo,方案为每日在低氧房(O2浓度为14.8%~14.3%,模拟海拔2800~3000米)居住10小时,每周进行3次75%VO2max强度的低氧训练(O2浓度为15.4%~14.8%,模拟海拔2500~2800米),运动时间为30 min/次,其余时间在常氧环境下训练.在HiHiLo前、后测定VO2max和SpO2.其SpO2的测定采用低氧环境下(15.4%O2,模拟海拔约2500米)的定量负荷运动实验,运动强度为HiHiLo前个体75%VO2max,运动时间15min.基因分型采用PCR结合荧光标记复合STR-genescan方法检测+4422(AC)n多态重复次数.结果:HiHiLo后,VO2max以及定量负荷运动dgSpO2均显著性提高,且(AC)11/(AC)11基因型者rVO2max训练敏感性显著高于(AC)11/(AC)12基因型者.结论:VEGFR2基因+4422(AC)n多态性与HiHiLo后rVO2max训练敏感性有关联,而与定量负荷下SpO2训练敏感性无关联.提示+4422(AC)n多态性可以作为预测低氧训练效果的分子遗传学标记,但还需加大样本量进一步验证.%Objective The purpose of this study was to explore the association between VEGFR2 gene+4422 (AC) n polymorphism to the sensitivity of HiHiLo. Methods Seventy one men of Han nationality in northern China underwent HiHiLo for 30 days. The subjects stayed in the hypoxic environment (14.8%~14.3%O2) 10 hours per day, and performed 30-minute hypoxic exercise ( 15.4%~ 14.8%O2) three times per week at the intensity of individual baseline VO2 max. The remaining training courses were completed at sea level. VO2 max and SpO2 were monitored before and after HiHiLo, in which SpO2 was tested through fixed load exercise in hypoxic environment (15.4%O2) at the intensity of individual baseline VO2 max. The genotypes were analyzed by STR-genescan. Results The absolute (L·min-1) and relative (ml

  4. PHLDA1 Promotes Lung Contusion by Regulating the Toll-Like Receptor 2 Signaling Pathway

    Directory of Open Access Journals (Sweden)

    Shaohua Wang

    2016-12-01

    Full Text Available Background/Aims: Lung contusion is a potentially lethal injury. Pleckstrin homology-like domain family A, member-1 (PHLDA1 is known to play crucial roles in cell proliferation and apoptosis. In this study, we investigated the biological role of PHLDA1 in lung contusion. Methods: The expression levels of PHLDA1 and TLR2 were detected by real time PCR and western. The cytokines were determined by ELISA. The inflammatory factors were detected by flow cytometry. The lung injury was determined by HE staining. Results: PHLDA1 gene and protein expression levels were up-regulated in a mouse lung-contusion model, together with increased neutrophil and macrophage contents. Down-regulation of PHLDA1 by interfering RNA (siPHLDA1 mice decreased lung injury and neutrophil infiltration. Inflammatory factors, including interleukin (IL-1β, IL-6, mouse homolog of human growth-regulated oncogene-α (KC, tumor necrosis factor-α, CC chemokine ligand (CCL 2, and CCL12 were also decreased in siPHLDA1 mice. Expression levels of Toll-like receptor 2 (TLR2 were increased in the lung-contusion mouse model, but were decreased when PHLDA1 was down-regulated. Conclusion: These results demonstrate that PHLDA1 plays a critical role in the development of progressive lung contusion and subsequent inflammation. This information furthers our understanding of the pathogenesis of lung contusion, and suggests that PHLDA1 blockade may represent a potential therapeutic strategy for the treatment of this injury.

  5. De-Escalation Strategies in Human Epidermal Growth Factor Receptor 2 (HER2)-Positive Early Breast Cancer (BC): Final Analysis of the West German Study Group Adjuvant Dynamic Marker-Adjusted Personalized Therapy Trial Optimizing Risk Assessment and Therapy Response Prediction in Early BC HER2- and Hormone Receptor-Positive Phase II Randomized Trial-Efficacy, Safety, and Predictive Markers for 12 Weeks of Neoadjuvant Trastuzumab Emtansine With or Without Endocrine Therapy (ET) Versus Trastuzumab Plus ET.

    Science.gov (United States)

    Harbeck, Nadia; Gluz, Oleg; Christgen, Matthias; Kates, Ronald Ernest; Braun, Michael; Küemmel, Sherko; Schumacher, Claudia; Potenberg, Jochem; Kraemer, Stefan; Kleine-Tebbe, Anke; Augustin, Doris; Aktas, Bahriye; Forstbauer, Helmut; Tio, Joke; von Schumann, Raquel; Liedtke, Cornelia; Grischke, Eva-Maria; Schumacher, Johannes; Wuerstlein, Rachel; Kreipe, Hans Heinrich; Nitz, Ulrike Anneliese

    2017-09-10

    Purpose Human epidermal growth factor receptor 2 (HER2)-positive/hormone receptor (HR)-positive breast cancer is a distinct subgroup associated with lower chemotherapy sensitivity and slightly better outcome than HER2-positive/HR-negative disease. Little is known about the efficacy of the combination of endocrine therapy (ET) with trastuzumab or with the potent antibody-cytotoxic, anti-HER2 compound trastuzumab emtansine (T-DM1) with or without ET for this subgroup. The West German Study Group trial, ADAPT (Adjuvant Dynamic Marker-Adjusted Personalized Therapy Trial Optimizing Risk Assessment and Therapy Response Prediction in Early Breast Cancer) compares pathologic complete response (pCR) rates of T-DM1 versus trastuzumab with ET in early HER2-positive/HR-positive breast cancer. Patients and Methods In this prospective, neoadjuvant, phase II trial, 375 patients with early breast cancer with HER2-positive and HR-positive status (n = 463 screened) were randomly assigned to 12 weeks of T-DM1 with or without ET or to trastuzumab with ET. The primary end point was pCR (ypT0/is/ypN0). Early response was assessed in 3-week post-therapeutic core biopsies (proliferation decrease ≥ 30% Ki-67 or cellularity response). Secondary end points included safety and predictive impact of early response on pCR. Adjuvant therapy followed national standards. Results Baseline characteristics were well balanced among the arms. More than 90% of patients completed the therapy per protocol. pCR was observed in 41.0% of patients treated with T-DM1, 41.5% of patients treated with T-DM1 and ET, and 15.1% with trastuzumab and ET ( P < .001). Early responders (67% of patients with assessable response) achieved pCR in 35.7% compared with 19.8% in nonresponders (odds ratio, 2.2; 95% CI, 1.24 to 4.19). T-DM1 was associated with a significantly higher prevalence of grade 1 to 2 toxicities, especially thrombocytopenia, nausea, and elevation of liver enzymes. Overall toxicity was low; seventeen

  6. Vascular endothelial (VEGF) and epithelial growth factor (EGF) as well as platelet-activating factor (PAF) and receptors are expressed in the early pregnant canine uterus.

    Science.gov (United States)

    Schäfer-Somi, S; Sabitzer, S; Klein, D; Reinbacher, E; Kanca, H; Beceriklisoy, H B; Aksoy, O A; Kucukaslan, I; Macun, H C; Aslan, S

    2013-02-01

    The aim of this study was to investigate the course of expression of platelet-activating factor (PAF), PAF-receptor (PAF-R), epidermal growth factor (EGF), EGF-R, vascular endothelial growth factor (VEGF), VEGF-R1 and VEGF-R2 in uterine tissue during canine pregnancy. For this purpose, 20 bitches were ovariohysterectomized at days 10-12 (n = 10), 18-25 (n = 5) and 28-45 (n = 5) days after mating, respectively. The pre-implantation group was proven pregnant by embryo flushing of the uterus after the operation, the others by sonography. Five embryo negative, that is, non-pregnant, bitches in diestrus (day 10-12) served as controls. Tissue samples from the uterus (placentation sites and horn width, respectively) were excised and snap-frozen in liquid nitrogen after embedding in Tissue Tec(®). Extraction of mRNA for RT-PCR was performed with Tri-Reagent. In the embryos, mRNA from all factors except VEGF was detected. In the course of pregnancy, significantly higher expression of PAF and PAFR as well as VEGF and VEGFR2 during the pre-implantation stage than in all other stages and a strong upregulation of EGF during implantation were characteristic. The course of EGF was in diametrical opposition to the course of the receptor. These results point towards an increased demand for VEGF, EGF and PAF during the earliest stages of canine pregnancy.

  7. Toll-like receptor 2 agonists inhibit human fibrocyte differentiation

    Directory of Open Access Journals (Sweden)

    Maharjan Anu S

    2010-11-01

    Full Text Available Abstract Background In healing wounds, some monocytes enter the wound and differentiate into fibroblast-like cells called fibrocytes. Since Toll-like receptors (TLRs are present on monocytes, and pathogens that can infect a wound have and/or release TLR agonists, we examined whether TLR agonists affect fibrocyte differentiation. Results When human peripheral blood mononuclear cells (PBMCs were cultured with TLR3, TLR4, TLR5, TLR7, TLR8 or TLR9 agonists, there was no significant effect on fibrocyte differentiation, even though enhanced extracellular tumor necrosis factor (TNF-α accumulation and/or increased cell surface CD86 or major histocompatibility complex (MHC class II levels were observed. However, all TLR2 agonists tested inhibited fibrocyte differentiation without any significant effect on cell survival. Adding TLR2 agonists to purified monocytes had no effect on fibrocyte differentiation. However, some TLR2 agonists caused PBMCs to secrete a factor that inhibits the differentiation of purified monocytes into fibrocytes. This factor is not interferon (IFN-α, IFN-γ, interleukin (IL-12, aggregated immunoglobulin G (IgG or serum amyloid P (SAP, factors known to inhibit fibrocyte differentiation. TLR2 agonist-treated PBMCs secrete low levels of IL-6, TNF-α, IFN-γ, granulocyte colony-stimulating factor and tumor growth factor β1, but combinations of these factors had no effect on fibrocyte differentiation from purified monocytes. Conclusions Our results indicate that TLR2 agonists indirectly inhibit fibrocyte differentiation and that, for some TLR2 agonists, this inhibition involves other cell types in the PBMC population secreting an unknown factor that inhibits fibrocyte differentiation. Together, these data suggest that the presence of some bacterial signals can inhibit fibrocyte differentiation and may thus slow wound closure.

  8. RNA interference against discoidin domain receptor 2 ameliorates alcoholic liver disease in rats.

    Directory of Open Access Journals (Sweden)

    Zheng Luo

    Full Text Available Discoidin domain receptor 2 (DDR2 is involved in fibrotic disease. However, the exact pathogenic implications of the receptor in early alcoholic liver disease are still controversial. We constructed plasmid vectors encoding short-hairpin RNA against DDR2 to investigate its role in alcoholic liver disease in an immortalized rat hepatic stellate cell line, HSC-T6, and in rats by MTT, RT-PCR and western blot analyses; immunohistochemistry and electron microscopy. Alcohol-induced upregulation of DDR2 was associated with the expression of matrix metalloproteinase 2, the transforming growth factor β1 signaling pathway and tissue inhibitor of metalloproteinase 1; collagen deposition; and extracellular matrix remodeling. Inhibition of DDR2 decreased HSC-T6 cell proliferation and liver injury in rats with 10-week-induced alcoholic liver disease. DDR2 may have an important role in the pathogenesis of early-stage alcoholic liver disease. Silencing DDR2 may be effective in preventing early-stage alcoholic liver disease.

  9. Prognostic significance of discoidin domain receptor 2 (DDR2) expression in ovarian cancer.

    Science.gov (United States)

    Fan, Yi; Xu, Zhe; Fan, Jin; Huang, Liu; Ye, Ming; Shi, Kun; Huang, Zheng; Liu, Yaqiong; He, Langchi; Huang, Jiezhen; Wang, Yibin; Li, Qiufeng

    2016-01-01

    Increasing evidence has suggested that discoidin domain receptor 2 (DDR2) plays an important role in cancer development and metastasis. However, the correlation between DDR2 expression and clinical outcome in ovarian cancer has not been investigated. In this study, DDR2 expression was examined by Real-time PCR in surgically resected ovarian cancer and normal ovary tissues. Besides, DDR2 expression was analyzed immunohistochemically in 103 ovarian cancer patients, and the correlation between DDR2 expression with clinicopathologic factors was analyzed. The result showed that DDR2 mRNA expression was upregulated in ovarian cancer tissues compared with normal ovary tissues. Statistical analysis revealed that DDR2 expression correlated with tumor stage (P = 0.008) and peritoneal metastasis (P = 0.009). Patients with high DDR2 expression showed poorer 5-year overall survival (P = 0.005), and DDR2 remained an independent prognostic marker for OS (P = 0.013) in multivariate analysis. Our results suggest that DDR2 might be closely associated with ovarian cancer progression and metastasis. Its high expression may serve as a potential prognostic biomarker in human ovarian cancer.

  10. RNA interference against discoidin domain receptor 2 ameliorates alcoholic liver disease in rats.

    Science.gov (United States)

    Luo, Zheng; Liu, Huimin; Sun, Xiaomeng; Guo, Rong; Cui, Ruibing; Ma, Xiangxing; Yan, Ming

    2013-01-01

    Discoidin domain receptor 2 (DDR2) is involved in fibrotic disease. However, the exact pathogenic implications of the receptor in early alcoholic liver disease are still controversial. We constructed plasmid vectors encoding short-hairpin RNA against DDR2 to investigate its role in alcoholic liver disease in an immortalized rat hepatic stellate cell line, HSC-T6, and in rats by MTT, RT-PCR and western blot analyses; immunohistochemistry and electron microscopy. Alcohol-induced upregulation of DDR2 was associated with the expression of matrix metalloproteinase 2, the transforming growth factor β1 signaling pathway and tissue inhibitor of metalloproteinase 1; collagen deposition; and extracellular matrix remodeling. Inhibition of DDR2 decreased HSC-T6 cell proliferation and liver injury in rats with 10-week-induced alcoholic liver disease. DDR2 may have an important role in the pathogenesis of early-stage alcoholic liver disease. Silencing DDR2 may be effective in preventing early-stage alcoholic liver disease.

  11. Surgical incision-induced nociception causes cognitive impairment and reduction in synaptic NMDA receptor 2B in mice.

    Science.gov (United States)

    Zhang, Xiaoqin; Xin, Xin; Dong, Yuanlin; Zhang, Yiying; Yu, Buwei; Mao, Jianren; Xie, Zhongcong

    2013-11-06

    Postoperative cognitive dysfunction (POCD) is associated with impairments in daily functioning, and increased morbidity and mortality. However, the causes and neuropathogenesis of POCD remain largely unknown. Uncontrolled pain often occurs postoperatively. We therefore set out to determine the effects of surgical incision-induced nociception on the cognitive function and its underlying mechanisms in 3- and 9-month-old mice. The mice had surgical incision in the hindpaw and then were tested for nociceptive threshold, learning, and memory. Brain levels of NMDA receptor and cyclin-dependent kinase 5 (CDK5) were also assessed. We found that surgical incision-induced nociception in mice led to a decreased freezing time in the tone test (which assesses the hippocampus-independent learning and memory function), but not the context test, of Fear Conditioning System at 3 and 7 d, but not 30 d post incision in 9-month-old, but not 3-month-old mice. Consistently, the surgical incision selectively decreased synaptic NMDA receptor 2B levels in the medial prefrontal cortex, and increased levels of tumor necrosis factor-α and CDK5 in the cortex, but not hippocampus, of the mice. Finally, eutectic mixture of local anesthetics and CDK5 inhibitor, roscovitine, attenuated the surgical incision-induced reduction in the synaptic NMDA receptor 2B levels and learning impairment. These results suggested that surgical incision-induced nociception reduced the synaptic NMDA receptor 2B level in the medial prefrontal cortex of mice, which might lead to hippocampus-independent learning impairment, contributing to POCD. These findings call for further investigation to determine the role of surgical incision-induced nociception in POCD.

  12. Effect of cannabinoid receptor 2 on body weight, blood lipids and inflammatory factor in obese mice%大麻素受体2对肥胖小鼠体质量、血脂及炎症因子的影响

    Institute of Scientific and Technical Information of China (English)

    陈彦; 陈刚; 余惠珍; 吴冰; 许桂平

    2014-01-01

    目的 研究大麻素受体2(type 2 cannabinoid receptor,CB2受体)对肥胖小鼠体质量、血甘油三酯(triglyceride,TG)、肿瘤坏死因子-α(tumor necrosis factor-alpha,TNF-α)和单核细胞趋化蛋白-1(monocyte chemoattractant protein-1,MCP-1)的影响.方法 20只雄性小鼠随机分为正常组(N组,n=4)、肥胖组(n=16),分别给予普通饲料和高脂饲料喂养6周,成功制作肥胖小鼠模型.再将肥胖组小鼠随机分为4组:模型组(S组,n=4)、CB2激动剂JWH-133干预组(J组,n=4)、CB2拮抗剂AM-630干预组(A组,n=4)、JWH-133+ AM-630干预组(AJ组,n=4).N组、S组腹腔内注射生理盐水,10 mg/kg,1次/天,共28 d;J、A、AJ组分别腹腔内注射JWH-133、AM-630、JWH-133+AM-630,10 mg/kg,1次/天,共28 d.药物干预前后测定小鼠的体质量、血TG、TNF-α、MCP-1水平.结果 给药第4周J组小鼠体质量、血TG、TNF-α、MCP-1水平均显著高于S组,A组上述指标均显著低于S组(P<0.05),AJ组指标与S组对比差异无统计学意义.结论 CB2受体在肥胖发病机制中起重要作用.激活CB2受体会增加肥胖小鼠体质量、血TG、TNF-α、MCP-1水平,抑制CB2受体会减低肥胖小鼠体质量、血TG、TNF-α、MCP-1水平.

  13. Antiangiogenic mechanisms of PJ-8, a novel inhibitor of vascular endothelial growth factor receptor signaling.

    Science.gov (United States)

    Huang, Shiu-Wen; Lien, Jin-Cherng; Kuo, Sheng-Chu; Huang, Tur-Fu

    2012-05-01

    Angiogenesis occurs not only during tissue growth and development but also during wound healing and tumor progression. Angiogenesis is a balanced process controlled by proangiogenic and antiangiogenic molecules. As a critical factor in the induction of angiogenesis, vascular endothelial growth factor (VEGF) has become an attractive target for antiangiogenic and cancer therapeutic agents. In an effort to develop novel inhibitors to block VEGF signaling, we selected Pj-8, a benzimidazole derivative, and investigated its inhibitory mechanisms in human umbilical vascular endothelial cells (HUVECs). Pj-8 concentration-dependently inhibited VEGF-induced proliferation, migration and tube formation of HUVECs. Pj-8 also suppressed VEGF-induced microvessel sprouting from aortic rings ex vivo and suppressed neovascularization of implanted matrigel plugs in vivo. Pj-8 inhibited VEGF-induced phosphorylation of VEGF receptor (VEGFR) 2 and the downstream protein kinases, including Akt, focal adhesion kinase, extracellular signal-regulated kinases and Src. Results from in vitro kinase assay further demonstrated that Pj-8 suppressed the kinase activity of 3-phosphoinositide-dependent kinase 1 (PDK1). Using xenograft tumor angiogenesis model, Pj-8 markedly eliminated tumor-associated angiogenesis. Taken together, our findings suggest that Pj-8 inhibits VEGF and tumor cells MDA-MB-231-induced angiogenesis, and it may be a potential drug candidate in anticancer therapy. Downregulation of VEGFR2-mediated signaling may contribute to its antiangiogenic actions.

  14. Targeting of Discoidin Domain Receptor 2 (DDR2) Prevents Myofibroblast Activation and Neovessel Formation During Pulmonary Fibrosis.

    Science.gov (United States)

    Zhao, Hu; Bian, Huan; Bu, Xin; Zhang, Shuya; Zhang, Pan; Yu, Jiangtian; Lai, Xiaofeng; Li, Di; Zhu, Chuchao; Yao, Libo; Su, Jin

    2016-10-01

    Idiopathic pulmonary fibrosis (IPF) is a lethal human disease with short survival time and few treatment options. Herein, we demonstrated that discoidin domain receptor 2 (DDR2), a receptor tyrosine kinase that predominantly transduces signals from fibrillar collagens, plays a critical role in the induction of fibrosis and angiogenesis in the lung. In vitro cell studies showed that DDR2 can synergize the actions of both transforming growth factor (TGF)-β and fibrillar collagen to stimulate lung fibroblasts to undergo myofibroblastic changes and vascular endothelial growth factor (VEGF) expression. In addition, we confirmed that late treatment of the injured mice with specific siRNA against DDR2 or its kinase inhibitor exhibited therapeutic efficacy against lung fibrosis. Thus, this study not only elucidated novel mechanisms by which DDR2 controls the development of pulmonary fibrosis, but also provided candidate target for the intervention of this stubborn disease.

  15. Protease-Activated Receptor 2 Promotes Pro-Atherogenic Effects through Transactivation of the VEGF Receptor 2 in Human Vascular Smooth Muscle Cells

    OpenAIRE

    Indrakusuma, Ira; Romacho, Tania; Eckel, Jürgen

    2017-01-01

    Background: Obesity is associated with impaired vascular function. In the cardiovascular system, protease-activated receptor 2 (PAR2) exerts multiple functions such as the control of the vascular tone. In pathological conditions, PAR2 is related to vascular inflammation. However, little is known about the impact of obesity on PAR2 in the vasculature. Therefore, we explored the role of PAR2 as a potential link between obesity and cardiovascular diseases. Methods: C57BL/6 mice were fed with eit...

  16. Regulation of pigmentation by microRNAs: MITF-dependent microRNA-211 targets TGF-β receptor 2.

    Science.gov (United States)

    Dai, Xiaodan; Rao, Chunbao; Li, Huirong; Chen, Yu; Fan, Lilv; Geng, Huiqin; Li, Shuang; Qu, Jia; Hou, Ling

    2015-03-01

    There is growing evidence that microRNAs are important regulators of gene expression in a variety of cell types. Using immortalized cell lines and primary neural crest cell explants, we show that microRNA-211, previously implicated in the regulation of melanoma proliferation and invasiveness, promotes pigmentation in melanoblasts and melanocytes. Expression of this microRNA is regulated by the key melanocyte transcription factor MITF and regulates pigmentation by targeting the TGF-β receptor 2. Transfection with pre-miR-211 precursor molecules in melb-a and melan-a cells leads to a decrease in the expression of TGF-β receptor 2 and reduces the TGF-β signaling-mediated downregulation of two melanogenic enzymes, tyrosinase and tyrosinase-related protein 1. Conversely, downregulation of microRNA-211 using specific microRNA inhibitors has the opposite effects. It appears, therefore, that microRNA-211 serves as a negative regulator of TGF-β signaling which is known to play a important roles in vivo in melanocyte stem cell maintenance and pigmentation.

  17. A biphasic endothelial stress-survival mechanism regulates the cellular response to vascular endothelial growth factor A

    Energy Technology Data Exchange (ETDEWEB)

    Latham, Antony M.; Odell, Adam F. [Endothelial Cell Biology Unit, School of Molecular and Cellular Biology, University of Leeds, Leeds LS2 9JT (United Kingdom); Mughal, Nadeem A. [Leeds Vascular Institute, Leeds General Infirmary, Great George Street, Leeds LS1 3EX (United Kingdom); Issitt, Theo; Ulyatt, Clare; Walker, John H. [Endothelial Cell Biology Unit, School of Molecular and Cellular Biology, University of Leeds, Leeds LS2 9JT (United Kingdom); Homer-Vanniasinkam, Shervanthi [Leeds Vascular Institute, Leeds General Infirmary, Great George Street, Leeds LS1 3EX (United Kingdom); Ponnambalam, Sreenivasan, E-mail: s.ponnambalam@leeds.ac.uk [Endothelial Cell Biology Unit, School of Molecular and Cellular Biology, University of Leeds, Leeds LS2 9JT (United Kingdom)

    2012-11-01

    Vascular endothelial growth factor A (VEGF-A) is an essential cytokine that regulates endothelial function and angiogenesis. VEGF-A binding to endothelial receptor tyrosine kinases such as VEGFR1 and VEGFR2 triggers cellular responses including survival, proliferation and new blood vessel sprouting. Increased levels of a soluble VEGFR1 splice variant (sFlt-1) correlate with endothelial dysfunction in pathologies such as pre-eclampsia; however the cellular mechanism(s) underlying the regulation and function of sFlt-1 are unclear. Here, we demonstrate the existence of a biphasic stress response in endothelial cells, using serum deprivation as a model of endothelial dysfunction. The early phase is characterized by a high VEGFR2:sFlt-1 ratio, which is reversed in the late phase. A functional consequence is a short-term increase in VEGF-A-stimulated intracellular signaling. In the late phase, sFlt-1 is secreted and deposited at the extracellular matrix. We hypothesized that under stress, increased endothelial sFlt-1 levels reduce VEGF-A bioavailability: VEGF-A treatment induces sFlt-1 expression at the cell surface and VEGF-A silencing inhibits sFlt-1 anchorage to the extracellular matrix. Treatment with recombinant sFlt-1 inhibits VEGF-A-stimulated in vitro angiogenesis and sFlt-1 silencing enhances this process. In this response, increased VEGFR2 levels are regulated by the phosphatidylinositol-3-kinase and PKB/Akt signaling pathways and increased sFlt-1 levels by the ERK1/2 signaling pathway. We conclude that during serum withdrawal, cellular sensing of environmental stress modulates sFlt-1 and VEGFR2 levels, regulating VEGF-A bioavailability and ensuring cell survival takes precedence over cell proliferation and migration. These findings may underpin an important mechanism contributing to endothelial dysfunction in pathological states. -- Highlights: Black-Right-Pointing-Pointer Endothelial cells mount a stress response under conditions of low serum. Black

  18. Role of Toll-like receptor 2/4-nuclear factor-κB signaling pathway in invasion of Mycobacterium tuberculosis to mouse dendritic cells%Toll 样受体2/4-核因子κB 信号通路在人结核分枝杆菌侵入小鼠树突细胞2.4中的作用

    Institute of Scientific and Technical Information of China (English)

    徐倩; 金梦媚; 郑文文; 朱丽; 徐水凌

    2014-01-01

    Objective: To investigate the mechanism of Mycobacterium tuberculosis invasion to mouse dendritic cells ( DC ) .Methods: Mycobacterium tuberculosis strain H37Rv was co-cultured with mouse DC2.4 cells.The mRNA expression of Toll-like receptor 2/4(TLR2/4) in DC2.4 cells was detected by fluorescent quantitative real-time PCR and the protein expression of nuclear factor κB ( NF-κB ) was assessed by Western blotting .The extracellular concentration of tumor necrosis factor α( TNF-α) was measured by ELISA methods during Mycobacterium Tuberculosis invasion .Indirect immunofluorescent staining and flow cytometry assay were used to detect the expression of CD80 and CD86 on DC2 .4 cells before and after invasion .Results:The invasion of Mycobacterium tuberculosis in DC2.4 cells was observed after 2 h of co-incubation.The rates of invasion were (37.9 ±5.6)%,(51.2 ±7.6)%,(57.2 ±8.9)%and(63.9 ± 6.8)% at 6,8,10 and 12 h after co-incubation,respectively.The mRNA expression level of TLR2 /4 was significantly increased at 6 h but decreased at 10 h after co-incubation.The expressions of NF-κB p65 and TNF-αwere higher in DC2.4 cells after being invaded by 6 , 8 , and 10 h and then gradually decreased .CD80 and CD86 expression were increased on DC 2 .4 at 6 h after co-incubation .Conclusion:Invasion of Mycobacterium tuberculosis strain H37 Rv to DC might enhance its antigen-presenting function through activation of TLR 2/4-NF-kB signaling pathway .%目的:研究人结核分枝杆菌侵入抗原提呈细胞后诱导树突细胞( DC )成熟的机制。方法:选择小鼠DC2.4细胞株为抗原提呈细胞的效应细胞,建立人结核分枝杆菌H37 Rv株的细胞混合培养模型。在不同混合培养时段,采用实时荧光定量PCR检测DC2.4细胞Toll样受体2(TLR2)、TLR4 mRNA的表达量;蛋白质印迹法检测DC的核因子κB ( NF-κB ) p65蛋白的表达;免疫酶联吸附试验定量检测DC产生α肿瘤坏死因子( TNF-α)

  19. Receptors for advanced glycation end products (RAGE) is associated with microvessel density and is a prognostic biomarker for clear cell renal cell carcinoma.

    Science.gov (United States)

    Guo, Yong; Xia, Peng; Zheng, Jian-Jian; Sun, Xian-Bin; Pan, Xiao-Dong; Zhang, Xing; Wu, Cun-Zao

    2015-07-01

    The receptor for advanced glycation end products (RAGE) is involved in a variety of biological processes, including tumorigenisis. Previous studies have demonstrated that RAGE regulates the neo-angiogenesis related downstream molecule - vascular endothelial growth factor receptor 2 (VEGFR-2). Here, we investigated the potential relationship between RAGE, VEGFR-2 and angiogenesis in 80 renal cell carcinoma (RCC) patients. Real-time quantitative PCR and ELISA analysis were used to explore the RAGE and VEGFR-2 gene expression levels and the protein of VEGFR-2 expression. Meanwhile, angiogenesis was detected by the semi-quantification of endothelial cell marker CD34 combined with caldesmon, which was detected by microvessel density (MVD) technique and immunohistochemistry. Tumors were classified as low or high RAGE-expressing using the median as the cut-off. Immunofluorescence staining for RAGE protein was performed as well. Additionally, the median gene expression levels of VEGFR-2 in the tumors were significantly lower expressing low levels of RAGE expression, 0.34 (95% CI, 0.28-0.39) compared to the expressing high levels of RAGE expression, 0.45 (95% CI, 0.29-0.61), (P=0.03). The median MVD was significantly lower in the tumors expressing low levels of RAGE, 6.5 (95% CI, 6.21-7.43), compared to the expressing high levels, 7.9 (95% CI, 6.25-8.93), (PRAGE expression are associated with high VEGFR-2 mRNA/protein levels and a higher density of microvessels; conversely, Kaplan-Meier survival analysis suggests that a significant correlation of elevated RAGE expression with decreased overall survival and metastasis-free survival. Our results establish that RAGE was identified as a potential prognostic biomarker for disease prognosis of RCC. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  20. Immunological quality and performance of tumor vessel-targeting CAR-T cells prepared by mRNA-EP for clinical research

    Directory of Open Access Journals (Sweden)

    Kanako Inoo

    2016-01-01

    Full Text Available We previously reported that tumor vessel-redirected T cells, which were genetically engineered with chimeric antigen receptor (CAR specific for vascular endothelial growth factor receptor 2 (VEGFR2, demonstrated significant antitumor effects in various murine solid tumor models. In the present study, we prepared anti-VEGFR2 CAR-T cells by CAR-coding mRNA electroporation (mRNA-EP and analyzed their immunological characteristics and functions for use in clinical research. The expression of anti-VEGFR2 CAR on murine and human T cells was detected with approximately 100% efficiency for a few days, after peaking 6–12 hours after mRNA-EP. Triple transfer of murine anti-VEGFR2 CAR-T cells into B16BL6 tumor-bearing mice demonstrated an antitumor effect comparable to that for the single transfer of CAR-T cells engineered with retroviral vector. The mRNA-EP did not cause any damage or defects to human T-cell characteristics, as determined by viability, growth, and phenotypic parameters. Additionally, two kinds of human anti-VEGFR2 CAR-T cells, which expressed different CAR construction, differentiated to effector phase with cytokine secretion and cytotoxic activity in antigen-specific manner. These results indicate that our anti-VEGFR2 CAR-T cells prepared by mRNA-EP have the potential in terms of quality and performance to offer the prospect of safety and efficacy in clinical research as cellular medicine.

  1. Distinct Signaling Cascades Elicited by Different Formyl Peptide Receptor 2 (FPR2 Agonists

    Directory of Open Access Journals (Sweden)

    Fabio Cattaneo

    2013-04-01

    Full Text Available The formyl peptide receptor 2 (FPR2 is a remarkably versatile transmembrane protein belonging to the G-protein coupled receptor (GPCR family. FPR2 is activated by an array of ligands, which include structurally unrelated lipids and peptide/proteins agonists, resulting in different intracellular responses in a ligand-specific fashion. In addition to the anti-inflammatory lipid, lipoxin A4, several other endogenous agonists also bind FPR2, including serum amyloid A, glucocorticoid-induced annexin 1, urokinase and its receptor, suggesting that the activation of FPR2 may result in potent pro- or anti-inflammatory responses. Other endogenous ligands, also present in biological samples, include resolvins, amyloidogenic proteins, such as beta amyloid (Aβ-42 and prion protein (Prp106–126, the neuroprotective peptide, humanin, antibacterial peptides, annexin 1-derived peptides, chemokine variants, the neuropeptides, vasoactive intestinal peptide (VIP and pituitary adenylate cyclase activating polypeptide (PACAP-27, and mitochondrial peptides. Upon activation, intracellular domains of FPR2 mediate signaling to G-proteins, which trigger several agonist-dependent signal transduction pathways, including activation of phospholipase C (PLC, protein kinase C (PKC isoforms, the phosphoinositide 3-kinase (PI3K/protein kinase B (Akt pathway, the mitogen-activated protein kinase (MAPK pathway, p38MAPK, as well as the phosphorylation of cytosolic tyrosine kinases, tyrosine kinase receptor transactivation, phosphorylation and nuclear translocation of regulatory transcriptional factors, release of calcium and production of oxidants. FPR2 is an attractive therapeutic target, because of its involvement in a range of normal physiological processes and pathological diseases. Here, we review and discuss the most significant findings on the intracellular pathways and on the cross-communication between FPR2 and tyrosine kinase receptors triggered by different FPR2

  2. Distinct Signaling Cascades Elicited by Different Formyl Peptide Receptor 2 (FPR2) Agonists

    Science.gov (United States)

    Cattaneo, Fabio; Parisi, Melania; Ammendola, Rosario

    2013-01-01

    The formyl peptide receptor 2 (FPR2) is a remarkably versatile transmembrane protein belonging to the G-protein coupled receptor (GPCR) family. FPR2 is activated by an array of ligands, which include structurally unrelated lipids and peptide/proteins agonists, resulting in different intracellular responses in a ligand-specific fashion. In addition to the anti-inflammatory lipid, lipoxin A4, several other endogenous agonists also bind FPR2, including serum amyloid A, glucocorticoid-induced annexin 1, urokinase and its receptor, suggesting that the activation of FPR2 may result in potent pro- or anti-inflammatory responses. Other endogenous ligands, also present in biological samples, include resolvins, amyloidogenic proteins, such as beta amyloid (Aβ)-42 and prion protein (Prp)106–126, the neuroprotective peptide, humanin, antibacterial peptides, annexin 1-derived peptides, chemokine variants, the neuropeptides, vasoactive intestinal peptide (VIP) and pituitary adenylate cyclase activating polypeptide (PACAP)-27, and mitochondrial peptides. Upon activation, intracellular domains of FPR2 mediate signaling to G-proteins, which trigger several agonist-dependent signal transduction pathways, including activation of phospholipase C (PLC), protein kinase C (PKC) isoforms, the phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt) pathway, the mitogen-activated protein kinase (MAPK) pathway, p38MAPK, as well as the phosphorylation of cytosolic tyrosine kinases, tyrosine kinase receptor transactivation, phosphorylation and nuclear translocation of regulatory transcriptional factors, release of calcium and production of oxidants. FPR2 is an attractive therapeutic target, because of its involvement in a range of normal physiological processes and pathological diseases. Here, we review and discuss the most significant findings on the intracellular pathways and on the cross-communication between FPR2 and tyrosine kinase receptors triggered by different FPR2 agonists. PMID

  3. Cluster headache and the hypocretin receptor 2 reconsidered: a genetic association study and meta-analysis.

    Science.gov (United States)

    Weller, Claudia M; Wilbrink, Leopoldine A; Houwing-Duistermaat, Jeanine J; Koelewijn, Stephany C; Vijfhuizen, Lisanne S; Haan, Joost; Ferrari, Michel D; Terwindt, Gisela M; van den Maagdenberg, Arn M J M; de Vries, Boukje

    2015-08-01

    Cluster headache is a severe neurological disorder with a complex genetic background. A missense single nucleotide polymorphism (rs2653349; p.Ile308Val) in the HCRTR2 gene that encodes the hypocretin receptor 2 is the only genetic factor that is reported to be associated with cluster headache in different studies. However, as there are conflicting results between studies, we re-evaluated its role in cluster headache. We performed a genetic association analysis for rs2653349 in our large Leiden University Cluster headache Analysis (LUCA) program study population. Systematic selection of the literature yielded three additional studies comprising five study populations, which were included in our meta-analysis. Data were extracted according to predefined criteria. A total of 575 cluster headache patients from our LUCA study and 874 controls were genotyped for HCRTR2 SNP rs2653349 but no significant association with cluster headache was found (odds ratio 0.91 (95% confidence intervals 0.75-1.10), p = 0.319). In contrast, the meta-analysis that included in total 1167 cluster headache cases and 1618 controls from the six study populations, which were part of four different studies, showed association of the single nucleotide polymorphism with cluster headache (random effect odds ratio 0.69 (95% confidence intervals 0.53-0.90), p = 0.006). The association became weaker, as the odds ratio increased to 0.80, when the meta-analysis was repeated without the initial single South European study with the largest effect size. Although we did not find evidence for association of rs2653349 in our LUCA study, which is the largest investigated study population thus far, our meta-analysis provides genetic evidence for a role of HCRTR2 in cluster headache. Regardless, we feel that the association should be interpreted with caution as meta-analyses with individual populations that have limited power have diminished validity. © International Headache Society 2014.

  4. Toll like Receptor 2 engagement on CD4(+) T cells promotes TH9 differentiation and function.

    Science.gov (United States)

    Karim, Ahmad Faisal; Reba, Scott M; Li, Qing; Boom, W Henry; Rojas, Roxana E

    2017-09-01

    We have recently demonstrated that mycobacterial ligands engage Toll like receptor 2 (TLR2) on CD4(+) T cells and up-regulate T-cell receptor (TCR) triggered Th1 responses in vitro and in vivo. To better understand the role of T-cell expressed TLR2 on CD4(+) T-cell differentiation and function, we conducted a gene expression analysis of murine naïve CD4(+) T-cells stimulated in the presence or absence of TLR2 co-stimulation. Unexpectedly, naïve CD4(+) T-cells co-stimulated via TLR2 showed a significant up-regulation of Il9 mRNA compared to cells co-stimulated via CD28. Under TH9 differentiation, we observed up-regulation of TH9 differentiation, evidenced by increases in both percent of IL-9 secreting cells and IL-9 in culture supernatants in the presence of TLR2 agonist both in polyclonal and Ag85B cognate peptide specific stimulations. Under non-polarizing conditions, TLR2 engagement on CD4(+) T-cells had minimal effect on IL-9 secretion and TH9 differentiation, likely due to a prominent effect of TLR2 signaling on IFN-γ secretion and TH1 differentiation. We also report that, TLR2 signaling in CD4(+) T cells increased expression of transcription factors BATF and PU.1, known to positively regulate TH9 differentiation. These results reveal a novel role of T-cell expressed TLR2 in enhancing the differentiation and function of TH9 T cells. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. 抗肿瘤坏死因子相关凋亡诱导配体受体2嵌合抗体表达载体的构建、表达及其抗肿瘤活性分析%Construction and stable expression of anti-human tumor necrosis factor-related apoptosis-inducing ligand receptor 2 chimeric antibody in CHO cells

    Institute of Scientific and Technical Information of China (English)

    吕付佳; 史娟; 张亚玺; 刘士廉; 刘彦信; 郑德先

    2011-01-01

    目的:构建抗人肿瘤坏死因子相关凋亡诱导配体(TRAIL)受体2(死亡受体5,DR5)的人-鼠嵌合抗体表达载体,获得稳定表达该嵌合抗体的细胞株,并分析嵌合抗体的抗肿瘤活性.方法:采用DNA重组技术,扩增抗人DR5的鼠源单克隆抗体(mAb)AD5-10的重链(HC)、轻链(LC)可变区基因片段,并将其分别插入含有人IgG重链、轻链恒定区基因的真核表达载体RpCI-neo,以重、轻链表达质粒共转染中国仓鼠卵巢细胞(CHO),筛选稳定表达抗人DR5嵌合抗体(hmAD5-10)的重组细胞.采用Western blot和间接ELISA检测嵌合抗体的表达量及其与抗原DR5的结合活性.采用MTS比色法检测嵌合抗体的生物学活性.并对重组细胞株进行无血清培养驯化.结果:获得了2株稳定表达嵌合抗体的重组细胞株CHO-A5和CHO-B11,抗体的表达水平分别为(0.36±0.11)mg/L和(0.16±0.01)mg/L,嵌合抗体与DR5有较好的结合活性,对体外培养的人T淋巴细胞白血病细胞SVT35有显著的杀伤作用.结论:在真核细胞中表达了具有生物学活性的抗DR5的人-鼠嵌合抗体,为其应用于肿瘤治疗研究奠定了基础.%AIM: To establish an human-mouse chimeric antibody against tumor necrosis factor-related apoptosisinducing ligand (TRAIL) receptor 2 (death receptor 5, DR5) in an eukaryotic cell line and analyse ifs tumoricidal activity. METHODS: The cDNAs encoding for the variable regions of heavy chain (VH) and light chain (VL) of AD5-10 were amplified by PCR and inserted into the human lgG heavy and light chain containing expression vector RpClneo, respectively. The recombinant plasmids were co-transfected into HEK293 and/or CHO cells. The production of anti-DR5 human-mouse chimeric antibody (hmAD5-10) and the antibody affinity for DR5 were identified by ELISA and Western blot assay. The tumoricidal activity of hmAD5-10 was demonstrated by MTS assay. The stable expression cells were selected and cultured in serum-free medium

  6. Pharmacological targeting of protease-activated receptor 2 affords protection from bleomycin-induced pulmonary fibrosis

    NARCIS (Netherlands)

    C. Lin (Cong); J. von der Thusen (Jan); J. Daalhuisen (Joost); M. Ten Brink (Marieke); B. Crestani (Bruno); T. van der Poll (Tom); K. Borensztajn (Keren); C. Arnold Spek (C.)

    2015-01-01

    textabstractIdiopathic pulmonary fibrosis is the most devastating diffuse fibrosing lung disease that remains refractory to therapy. Despite increasing evidence that protease-activated receptor 2 (PAR-2) contributes to fibrosis, its importance in pulmonary fibrosis is under debate. We addressed whet

  7. The Role of Toll-Like Receptor 2 in Inflammation and Fibrosis during Progressive Renal Injury

    NARCIS (Netherlands)

    Leemans, J.C.; Butter, L.M.; Pulskens, W.P.C.; Teske, G.J.D.; Claessen, N.; van der Poll, T.; Florquin, S.

    2009-01-01

    Tissue fibrosis and chronic inflammation are common causes of progressive organ damage, including progressive renal disease, leading to loss of physiological functions. Recently, it was shown that Toll-like receptor 2 (TLR2) is expressed in the kidney and activated by endogenous danger signals. The

  8. The Role of Toll-Like Receptor 2 in Inflammation and Fibrosis during Progressive Renal Injury

    NARCIS (Netherlands)

    Leemans, J.C.; Butter, L.M.; Pulskens, W.P.C.; Teske, G.J.D.; Claessen, N.; van der Poll, T.; Florquin, S.

    2009-01-01

    Tissue fibrosis and chronic inflammation are common causes of progressive organ damage, including progressive renal disease, leading to loss of physiological functions. Recently, it was shown that Toll-like receptor 2 (TLR2) is expressed in the kidney and activated by endogenous danger signals. The

  9. PROGNOSTIC FACTORS OF BIOCHEMICAL RECURRENCE AFTER RADICAL PROSTATECTOMY FOR LOCALIZED AND LOCALLY-ADVANCED PROSTATE CANCER

    Directory of Open Access Journals (Sweden)

    V. A. Chernyaev

    2014-08-01

    Full Text Available Purpose. To reveal prognostic factors of PSA-failure following radical prostatectomy in patients with localized and locally-advanced prostate cancer.Materials and methods. Medical data of 386 consecutive patients with localized and locally-advanced prostate cancer who underwent radical prostatectomy from 1997 to 2011 were analyzed. Median age was 61.0 years. Median PSA before surgery – 10.3 ng/ml. Plasma levels of VEGF, VEGFR2, VEGFR3, TGF-β1, CD105, IL-6 were measured using Enzyme Linked-Immuno-Sorbent Assay (ELISA before radical prostatectomy in 77 patients. Postoperatively the tumours were categorized as pT2 in 288 (59.1 %, pT3 – in 144 (37.3 %, pT4 – in 14 (3.6; pN+ – in 34 (8.8 % cases. Gleason score < 7 was present in 254 (65.8 %,  7 – in 132 (34.2 % specimens. Perineural invasion was identified in 188 (48.7 %, angiolymphatic invasion – in 126 (32.6 cases.Results. Biochemical recurrence occurred in 64 (16.6 % out of 386 patients at a median follow-up of 30.5 (12−164 months. Independent predictors of biochemical recurrence were PSA (HR 0.161 (95% CI:0.058−0.449; р = 0.001, Gleason sum in surgical specimens (HR 0.496 (95 % CI:0.268−0.917; p = 0.025, pN (HR 0.415 (95 % CI:0.181−0.955; p = 0.039. The patients were divided into 3 prognostic groups: good (0 factor, intermediate (1 factor, poor (2 factors and very poor (3 factors (AUC – 0.720 (95% CI: 0.656−0.784. High preoperative levels VEGF ( 67 pg/ml (р = 0.005, VEGFR2 ( 3149 pg/ml (р = 0.036, VEGFR3 ( 2268 pg/ml (р = 0.001, TGF-β1 ( 14473 pg/ml (р = 0.052 were identified as unfavorable prognostic factors for survival without PSA-failure. Conclusion. Independent prognostic factors of biochemical recurrence after prostatectomy were PSA, Gleason sum and pN. Joint effect of the factors allows to predict PSA-relapse with accuracy 0.720. Preoperative serum levels VEGF, VEGFR2, VEGFR3, TGF-β1 potentially are perspective markers for PSA-failure after

  10. PROGNOSTIC FACTORS OF BIOCHEMICAL RECURRENCE AFTER RADICAL PROSTATECTOMY FOR LOCALIZED AND LOCALLY-ADVANCED PROSTATE CANCER

    Directory of Open Access Journals (Sweden)

    V. A. Chernyaev

    2012-01-01

    Full Text Available Purpose. To reveal prognostic factors of PSA-failure following radical prostatectomy in patients with localized and locally-advanced prostate cancer.Materials and methods. Medical data of 386 consecutive patients with localized and locally-advanced prostate cancer who underwent radical prostatectomy from 1997 to 2011 were analyzed. Median age was 61.0 years. Median PSA before surgery – 10.3 ng/ml. Plasma levels of VEGF, VEGFR2, VEGFR3, TGF-β1, CD105, IL-6 were measured using Enzyme Linked-Immuno-Sorbent Assay (ELISA before radical prostatectomy in 77 patients. Postoperatively the tumours were categorized as pT2 in 288 (59.1 %, pT3 – in 144 (37.3 %, pT4 – in 14 (3.6; pN+ – in 34 (8.8 % cases. Gleason score < 7 was present in 254 (65.8 %,  7 – in 132 (34.2 % specimens. Perineural invasion was identified in 188 (48.7 %, angiolymphatic invasion – in 126 (32.6 cases.Results. Biochemical recurrence occurred in 64 (16.6 % out of 386 patients at a median follow-up of 30.5 (12−164 months. Independent predictors of biochemical recurrence were PSA (HR 0.161 (95% CI:0.058−0.449; р = 0.001, Gleason sum in surgical specimens (HR 0.496 (95 % CI:0.268−0.917; p = 0.025, pN (HR 0.415 (95 % CI:0.181−0.955; p = 0.039. The patients were divided into 3 prognostic groups: good (0 factor, intermediate (1 factor, poor (2 factors and very poor (3 factors (AUC – 0.720 (95% CI: 0.656−0.784. High preoperative levels VEGF ( 67 pg/ml (р = 0.005, VEGFR2 ( 3149 pg/ml (р = 0.036, VEGFR3 ( 2268 pg/ml (р = 0.001, TGF-β1 ( 14473 pg/ml (р = 0.052 were identified as unfavorable prognostic factors for survival without PSA-failure. Conclusion. Independent prognostic factors of biochemical recurrence after prostatectomy were PSA, Gleason sum and pN. Joint effect of the factors allows to predict PSA-relapse with accuracy 0.720. Preoperative serum levels VEGF, VEGFR2, VEGFR3, TGF-β1 potentially are perspective markers for PSA-failure after

  11. VASCULAR ENDOTHELIAL GROWTH FACTOR IN HEALTH AND DISEASE: A REVIEW

    Directory of Open Access Journals (Sweden)

    Niranjan Gopal

    2016-10-01

    Full Text Available BACKGROUND Vascular Endothelial Growth Factor (VEGF has been implicated as a key molecule, which regulates physiological angiogenesis. VEGF exerts its molecular actions through Receptor Tyrosine Kinases (RTKs VEGFR-1 and VEGFR-2, differ in signaling properties. VEGF plays a vital role in embryogenesis, growth and reproduction. VEGF as a mediator of pathological angiogenesis is associated with proliferation and micrometastasis of various tumours, ocular disorders involving neovascularisation, pre-eclampsia, etc. The pathogenesis of micro and macrovascular complications of diabetes mellitus and the role of VEGF is being studied extensively. Currently, several pharmacological interventions based on VEGF inhibitors and receptor antagonists have been tried to combat the pathological angiogenesis in a wide gamut of disorders. This review attempts to put together important properties, mechanism of action and the role of VEGF in common diseased states. CONCLUSION Effects of VEGF are widespread and have been implicated in several disease states. Therapeutic modalities targeting VEGF have been tried with success in recent years.

  12. Spinal vascular endothelial growth factor (VEGF) and erythropoietin (EPO) induced phrenic motor facilitation after repetitive acute intermittent hypoxia.

    Science.gov (United States)

    Dale, Erica A; Mitchell, Gordon S

    2013-02-01

    Vascular endothelial growth factor (VEGF) and erythropoietin (EPO) exert neurotrophic and neuroprotective effects in the CNS. We recently demonstrated that VEGF, EPO and their receptors (VEGF-R2, EPO-R) are expressed in phrenic motor neurons, and that cervical spinal VEGF-R2 and EPO-R activation elicit long-lasting phrenic motor facilitation (pMF). Since VEGF, VEGF-R, EPO, and EPO-R are hypoxia-regulated genes, and repetitive exposure to acute intermittent hypoxia (rAIH) up-regulates these molecules in phrenic motor neurons, we tested the hypothesis that 4 weeks of rAIH (10 episodes per day, 3 days per week) enhances VEGF- or EPO-induced pMF. We confirm that cervical spinal VEGF and EPO injections elicit pMF. However, neither VEGF- nor EPO-induced pMF was affected by rAIH pre-conditioning (4 wks). Although our data confirm that spinal VEGF and EPO may play an important role in respiratory plasticity, we provide no evidence that rAIH amplifies their impact. Further experiments with more robust protocols are warranted.

  13. Impact of type 2 diabetes on the plasma levels of vascular endothelial growth factor and its soluble receptors type 1 and type 2 in patients with peripheral arterial disease%2型糖尿病对外周动脉疾病患者血浆内的血管内皮生长因子及其可溶性受体浓度的影响

    Institute of Scientific and Technical Information of China (English)

    Radosaw WIECZR; Grayna GADOMSKA; Barbara RUSZKOWSKA-CIASTEK; Katarzyna STANKOWSKA; Jacek BUDZYSKI; Jacek FABISIAK; Karol SUPPAN; Grzegorz PULKOWSKI; Danuta RO

    2015-01-01

    Objective: Type 2 diabetes coexistent with lower extremity artery disease (peripheral arterial disease (PAD)) can be observed in numerous patients. The mechanism compensating for ischemia and contributing to healing is angiogenesis—the process of forming new blood vessels. The purpose of this study was to assess the likely impact of type 2 diabetes on the plasma levels of proangiogenic factor (vascular endothelial growth factor A (VEGF-A)) and angiogenesis inhibitors (soluble VEGF receptors type 1 and type 2 (sVEGFR-1 and sVEGFR-2)) in patients with PAD. Methods: Among 46 patients with PAD under pharmacological therapy (non-invasive), we identified, based on medical history, a subgroup with coexistent type 2 diabetes (PAD-DM2+,n=15) and without diabetes (PAD-DM2−,n=31). The control group consisted of 30 healthy subjects. Plasma levels of VEGF-A, sVEGFR-1, and sVEGFR-2 were measured using the enzyme-linked immunosorbent assay (ELISA) method. Results: The subgroups of PAD-DM2+ and PAD-DM2− revealed significantly higher concentrations of VEGF-A (P=0.000007 andP=0.0000001, respectively) and signifi-cantly lower sVEGFR-2 levels (P=0.02 andP=0.00001, respectively), when compared with the control group. Patients with PAD and coexistent diabetes tended to have a lower level of VEGF-A and higher levels of sVEGFR-1 and sVEGFR-2 comparable with non-diabetic patients. Conclusions:The coexistence of type 2 diabetes and PAD is demonstrated by a tendency to a lower plasma level of proangiogenic factor (VEGF-A) and higher levels of angio-genesis inhibitors (sVEGFR-1 and sVEGFR-2) at the same time. Regardless of the coexistence of type 2 diabetes, hypoxia appears to be a crucial factor stimulating the processes of angiogenesis in PAD patients comparable with healthy individuals, whereas hyperglycemia may have a negative impact on angiogenesis in lower limbs.%目的:研究2型糖尿病对外周动脉疾病患者血浆内的血管内皮生长因子( VEGF-A )

  14. Up-regulation of Toll-like receptors 2, 3 and 4 in allergic rhinitis

    Directory of Open Access Journals (Sweden)

    Uddman Rolf

    2005-09-01

    Full Text Available Abstract Background Toll-like receptors enable the host to recognize a large number of pathogen-associated molecular patterns such as bacterial lipopolysaccharide, viral RNA, CpG-containing DNA and flagellin. Toll-like receptors have also been shown to play a pivotal role in both innate and adaptive immune responses. The role of Toll-like receptors as a primary part of our microbe defense system has been shown in several studies, but their possible function as mediators in allergy and asthma remains to be established. The present study was designed to examine the expression of Toll-like receptors 2, 3 and 4 in the nasal mucosa of patients with intermittent allergic rhinitis, focusing on changes induced by exposure to pollen. Methods 27 healthy controls and 42 patients with seasonal allergic rhinitis volunteered for the study. Nasal biopsies were obtained before and during pollen season as well as before and after allergen challenge. The seasonal material was used for mRNA quantification of Toll-like receptors 2, 3 and 4 with real-time polymerase chain reaction, whereas specimens achieved in conjunction with allergen challenge were used for immunohistochemical localization and quantification of corresponding proteins. Results mRNA and protein representing Toll-like receptors 2, 3 and 4 could be demonstrated in all specimens. An increase in protein expression for all three receptors could be seen following allergen challenge, whereas a significant increase of mRNA only could be obtained for Toll-like receptor 3 during pollen season. Conclusion The up-regulation of Toll-like receptors 2, 3 and 4 in the nasal mucosa of patients with symptomatic allergic rhinitis supports the idea of a role for Toll-like receptors in allergic airway inflammation.

  15. The protease-activated receptor-2 agonist induces gastric mucus secretion and mucosal cytoprotection

    OpenAIRE

    Kawabata, Atsufumi; Kinoshita, Mitsuhiro; Nishikawa, Hiroyuki; Kuroda, Ryotaro; Nishida, Minoru; Araki, Hiromasa; Arizono, Naoki; Oda, Yasuo; Kakehi, Kazuaki

    2001-01-01

    Protease-activated receptor-2 (PAR-2), a receptor activated by trypsin/tryptase, modulates smooth muscle tone and exocrine secretion in the salivary glands and pancreas. Given that PAR-2 is expressed throughout the gastrointestinal tract, we investigated effects of PAR-2 agonists on mucus secretion and gastric mucosal injury in the rat. PAR-2–activating peptides triggered secretion of mucus in the stomach, but not in the duodenum. This mucus secretion was abolished by pretreatment with capsai...

  16. Prognostic significance of discoidin domain receptor 2 (DDR2) expression in ovarian cancer

    OpenAIRE

    Fan, Yi; Xu, Zhe; Fan, Jin; Huang, Liu; Ye, Ming; Shi, Kun; Huang, Zheng; Liu, Yaqiong; He, Langchi; Huang, Jiezhen; Wang, Yibin; Li, Qiufeng

    2016-01-01

    Increasing evidence has suggested that discoidin domain receptor 2 (DDR2) plays an important role in cancer development and metastasis. However, the correlation between DDR2 expression and clinical outcome in ovarian cancer has not been investigated. In this study, DDR2 expression was examined by Real-time PCR in surgically resected ovarian cancer and normal ovary tissues. Besides, DDR2 expression was analyzed immunohistochemically in 103 ovarian cancer patients, and the correlation between D...

  17. Mutation analysis of the transferrin receptor-2 gene in patients with iron overload.

    Science.gov (United States)

    Lee, P L; Halloran, C; West, C; Beutler, E

    2001-01-01

    Three mutations in the transferrin receptor-2 gene have recently been identified in four Sicilian families with iron overload who had a normal hemochromatosis gene, HFE (C. Camaschella, personal communication). To determine the extent to which mutations in the transferrin receptor-2 gene occur in other populations with iron overload, we have completely sequenced this gene in 17 whites, 10 Asians, and 8 African Americans with iron overload and a C282C/C282C HFE genotype, as well as 4 subjects without iron overload and homozygous for the mutant HFE C282Y genotype, 5 patients with iron overload and homozygous for the mutant HFE C282Y genotype, and 5 normal individuals. None of the individuals exhibited the Sicilian mutations, Y250X in exon 6, M172K in exon 4, and E60X in exon 2. One iron-overloaded individual of Asian descent exhibited a I238M mutation which was subsequently found to be a polymorphism present in the Asian population at a frequency of 0.0192. The presence of the I238M mutation was not associated with an increase in ferritin or transferrin saturation levels. Three silent polymorphisms were also identified, nt 1770 (D590D) and nt 1851 (A617A) and a polymorphism at nt 2255 in the 3' UTR. Thus, mutations in the transferrin receptor-2 gene were not responsible for the iron overload seen in our subjects.

  18. Efecto del polimorfismo del receptor ? 2 adrenérgico sobre la respuesta antihipertensiva en pacientes con hipertensión esencial

    OpenAIRE

    Juan McEwen; Edwin García; Isaac Melguizo; Juan Carlos Méndez; Dagnovar Aristizabal

    2004-01-01

    La hipertensión arterial esencial (HTE) es uno de los principales factores de riesgo cardiovascular y generador indirecto de la enfermedad coronaria, la mayor causa de muertes en Colombia y el mundo [1].
    El Sistema Nervioso Simpático (SNS) modifica la resistencia
    arterial periférica a través del receptor ? 2 adrenérgico,  generando señales intracelulares que regulan la relajación del
    músculo liso vascular. Este receptor experimenta un proceso
    denomi...

  19. r84, a novel therapeutic antibody against mouse and human VEGF with potent anti-tumor activity and limited toxicity induction.

    Directory of Open Access Journals (Sweden)

    Laura A Sullivan

    Full Text Available Vascular endothelial growth factor (VEGF is critical for physiological and pathological angiogenesis. Within the tumor microenvironment, VEGF functions as an endothelial cell survival factor, permeability factor, mitogen, and chemotactic agent. The majority of these functions are mediated by VEGF-induced activation of VEGF receptor 2 (VEGFR2, a high affinity receptor tyrosine kinase expressed by endothelial cells and other cell types in the tumor microenvironment. VEGF can also ligate other cell surface receptors including VEGFR1 and neuropilin-1 and -2. However, the importance of VEGF-induced activation of these receptors in tumorigenesis is still unclear. We report the development and characterization of r84, a fully human monoclonal antibody that binds human and mouse VEGF and selectively blocks VEGF from interacting with VEGFR2 but does not interfere with VEGF:VEGFR1 interaction. Selective blockade of VEGF binding to VEGFR2 by r84 is shown through ELISA, receptor binding assays, receptor activation assays, and cell-based functional assays. Furthermore, we show that r84 has potent anti-tumor activity and does not alter tissue histology or blood and urine chemistry after chronic high dose therapy in mice. In addition, chronic r84 therapy does not induce elevated blood pressure levels in some models. The ability of r84 to specifically block VEGF:VEGFR2 binding provides a valuable tool for the characterization of VEGF receptor pathway activation during tumor progression and highlights the utility and safety of selective blockade of VEGF-induced VEGFR2 signaling in tumors.

  20. r84, a Novel Therapeutic Antibody against Mouse and Human VEGF with Potent Anti-Tumor Activity and Limited Toxicity Induction

    Science.gov (United States)

    Sullivan, Laura A.; Carbon, Juliet G.; Roland, Christina L.; Toombs, Jason E.; Nyquist-Andersen, Mari; Kavlie, Anita; Schlunegger, Kyle; Richardson, James A.; Brekken, Rolf A.

    2010-01-01

    Vascular endothelial growth factor (VEGF) is critical for physiological and pathological angiogenesis. Within the tumor microenvironment, VEGF functions as an endothelial cell survival factor, permeability factor, mitogen, and chemotactic agent. The majority of these functions are mediated by VEGF-induced activation of VEGF receptor 2 (VEGFR2), a high affinity receptor tyrosine kinase expressed by endothelial cells and other cell types in the tumor microenvironment. VEGF can also ligate other cell surface receptors including VEGFR1 and neuropilin-1 and -2. However, the importance of VEGF-induced activation of these receptors in tumorigenesis is still unclear. We report the development and characterization of r84, a fully human monoclonal antibody that binds human and mouse VEGF and selectively blocks VEGF from interacting with VEGFR2 but does not interfere with VEGF∶VEGFR1 interaction. Selective blockade of VEGF binding to VEGFR2 by r84 is shown through ELISA, receptor binding assays, receptor activation assays, and cell-based functional assays. Furthermore, we show that r84 has potent anti-tumor activity and does not alter tissue histology or blood and urine chemistry after chronic high dose therapy in mice. In addition, chronic r84 therapy does not induce elevated blood pressure levels in some models. The ability of r84 to specifically block VEGF∶VEGFR2 binding provides a valuable tool for the characterization of VEGF receptor pathway activation during tumor progression and highlights the utility and safety of selective blockade of VEGF-induced VEGFR2 signaling in tumors. PMID:20700512

  1. Polymorphisms in the dopamine receptor 2 gene region influence improvements during working memory training in children and adolescents.

    Science.gov (United States)

    Söderqvist, Stina; Matsson, Hans; Peyrard-Janvid, Myriam; Kere, Juha; Klingberg, Torkel

    2014-01-01

    Studying the effects of cognitive training can lead to finding better treatments, but it can also be a tool for investigating factors important for brain plasticity and acquisition of cognitive skills. In this study, we investigated how single-nucleotide polymorphisms (SNPs) and ratings of intrinsic motivation were associated to interindividual differences in improvement during working memory training. The study included 256 children aged 7-19 years who were genotyped for 13 SNPs within or near eight candidate genes previously implicated in learning: COMT, SLC6A3 (DAT1), DRD4, DRD2, PPP1R1B (DARPP32), MAOA, LMX1A, and BDNF. Ratings on the intrinsic motivation inventory were also available for 156 of these children. All participants performed at least 20 sessions of working memory training, and performance during the training was logged and used as the outcome variable. We found that two SNPs, rs1800497 and rs2283265, located near and within the dopamine receptor 2 (DRD2) gene, respectively, were significantly associated with improvements during training (p results suggest that genetic variation is accounting for some interindividual differences in how children acquire cognitive skills and that part of this effect is also seen on intrinsic motivation. Moreover, they suggest that dopamine D2 transmission in the BG is a key factor for cognitive plasticity.

  2. Protection of protease-activated receptor 2 mediated vasodilatation against angiotensin II-induced vascular dysfunction in mice

    OpenAIRE

    Chia, Elizabeth; Kagota, Satomi; Wijekoon, Enoka P; McGuire, John J

    2011-01-01

    Background Under conditions of cardiovascular dysfunction, protease-activated receptor 2 (PAR2) agonists maintain vasodilatation activity, which has been attributed to increased cyclooxygenase-2, nitric oxide synthase and calcium-activated potassium channel (SK3.1) activities. Protease-activated receptor 2 agonist mediated vasodilatation is unknown under conditions of dysfunction caused by angiotensin II. The main purpose of our study was to determine whether PAR2-induced vasodilatation of re...

  3. [Association between serotonin receptor 2C gene Cys23Ser polymorphism and social behavior in schizophrenia patients and healthy individuals].

    Science.gov (United States)

    Alfimova, M V; Golimbet, V E; Korovaitseva, G I; Abramova, L I; Kaleda, V G

    2015-02-01

    The purpose of this work was to search for associations between the serotonin receptor 2C gene (HTR2C) and the peculiarities of social behavior and social cognition in schizophrenia. To do this, patients with schizophrenia spectrum disorders and healthy control subjects were genotyped for the Cys23Ser HTR2C marker and underwent psychological examination, including assessment of Machiavellianism, recognition of emotions in facial expression, and theory of mind. In addition, we estimated the trait anxiety level as a potential factor affecting the relationship between the gene HTR2C and social behavior. We found a significant association between the Ser allele and a reduction of estimates on the Mach-LV Machiavellianism scale in the total sample of patients (n = 182) and control subjects (n = 189), which did not reach the confidence level in either of the groups. A tendency towards a HTR2C gene influence on the trait anxiety level was also revealed. The association between HTR2C and Machiavellianism was retained if the anxiety level was taken into account. The results suggest a pleiotropic effect of HTR2Con anxiety and Machiavellianism.

  4. Oxidized low-density lipoprotein-induced foam cell formation is mediated by formyl peptide receptor 2.

    Science.gov (United States)

    Lee, Ha Young; Oh, Eunseo; Kim, Sang Doo; Seo, Jeong Kon; Bae, Yoe-Sik

    2014-01-17

    The increased level of LDL and its modification into oxLDL has been regarded as an important risk factor for the development of cardiovascular diseases such as atherosclerosis. Although some scavenger receptors including CD36 and RAGE have been considered as target receptors for oxLDL, involvement of other receptors should be investigated for oxLDL-induced pathological responses. In this study, we found that oxLDL-induced foam cell formation was inhibited by formyl peptide receptor 2 (FPR2) antagonist WRW(4). oxLDL also stimulated calcium signaling and chemotactic migration in FPR2-expressing RBL-2H3 cells but not in vector-expressing RBL-2H3 cells. Moreover, oxLDL stimulated TNF-α production, which was also almost completely inhibited by FPR2 antagonist. Our findings therefore suggest that oxLDL stimulates macrophages, resulting in chemotactic migration, TNF-α production, and foam cell formation via FPR2 signaling, and thus likely contributes to atherogenesis. Copyright © 2013 Elsevier Inc. All rights reserved.

  5. Roles of Toll-like receptors 2 and 4 in mediating experimental autoimmune orchitis induction in mice.

    Science.gov (United States)

    Liu, Zhenghui; Zhao, Shutao; Chen, Qiaoyuan; Yan, Keqin; Liu, Peng; Li, Nan; Cheng, C Yan; Lee, Will M; Han, Daishu

    2015-03-01

    The mammalian testis is an immunoprivileged site where male germ cell antigens are immunologically tolerated under physiological conditions. However, some pathological conditions can disrupt the immunoprivileged status and induce autoimmune orchitis, an etiological factor of male infertility. Mechanisms underlying autoimmune orchitis induction are largely unknown. The present study investigated the roles of Toll-like receptor 2 (TLR2) and TLR4 in mediating the induction of experimental autoimmune orchitis (EAO) in mice after immunization with male germ cell antigens emulsified with complete Freund adjuvant. Wild-type mice developed severe EAO after three immunizations, which was characterized by leukocyte infiltration, autoantibody production, and impaired spermatogenesis. Tlr2 or Tlr4 deficient mice showed relatively low susceptibility to EAO induction compared with wild-type mice. Notably, Tlr2 and Tlr4 double knockout mice were almost completely protected from EAO induction. Moreover, we demonstrated that TLR2 was crucial in mediating autoantibody production in response to immunization. The results imply that TLR2 and TLR4 cooperatively mediate EAO induction.

  6. REGULAR EXPRESSION OF DISCOIDIN DOMAIN RECEPTOR 2 IN THE IMPROVED ADJUVANT-INDUCED ANIMAL MODEL FOR RHEUMATOID ARTHRITIS

    Institute of Scientific and Technical Information of China (English)

    Wei Li; Yuan-qiang Zhang; Xin-ping Liu; Li-bo Yao; Lan Sun

    2005-01-01

    Objective To investigate the expression of discoidin domain receptor 2 (DDR2) of fibroblast-like synovial cells in improved adjuvant-induced animal (AIA) model for rheumatoid arthritis (RA) and to provide evidence for DDR2′s antagonist use clinically.Methods AIA was modified by administrating 0.1 mL of complete Freund′s adjuvant (CFA, mixed with 5 mg Bacillus Calmette-Guerin vaccine/mL) into rats′ right hind paws and 0.125 mL tumor necrosis factor-α (2 U/mL) into right ankles and subpatellar fatty tissue. The expression of DDR2 in fibroblast-like synovial cells was assessed using immunohistochemistry,immunofluorescence histochemistry, and in situ hybridization methods. Levels of anti-collagen Ⅱ antibody were measured using enzyme-linked immunosorbent assay.Results Given the terms mentioned above, we found a more practical rat model, apparently decreasing immunization time (average 3-5 days). DDR2 can be detected upon the 15th day of immunization; expression gradually increased with time going on, and reaching a peak 35 days after immunization before gradually decreasing. Serum anti-collagen Ⅱ antibody showed similar expression patterns as DDR2, but reached peak later than DDR2, about 40 days after immunization.Conclusion Regular expression of DDR2 in animal models infers its important role in the pathological process of RA.

  7. 溶血磷脂酸受体2%Research progress on lysophosphatidic acid receptor 2

    Institute of Scientific and Technical Information of China (English)

    龚晓华; 饶勇; 马卫列; 张志珍

    2013-01-01

    Lysophosphatidic acid receptor 2 (LPA2), also known as endothelial differentiation gene receptor 4 (EDG4), is a G-protein coupled receptor (GPCR) activated by lysophosphatidic acid. It has high affinity to lysophosphatidic acid, and can mediate many kinds of cellular activities. Recent researches have shown that LPA2/EDG4 is overexpressed in ovarian cancer cells. In addition, it is closely connected with breast carcinoma, colon cancer, atherosclerosis, respiratory disease and hypertensivedisorder complicating pregnancy.%溶血磷脂酸受体2 (lysophosphatidic acid receptor 2,LPA2),也称内皮分化基因受体4(endothelial differentiation gene receptor4,EDG4),是溶血磷脂酸G蛋白偶联受体类的一种,对溶血磷脂酸有较高亲和力,可介导多种细胞活动.近年研究发现,LPA2/EDG4在卵巢癌细胞中过表达,同时与乳腺癌、结直肠癌、动脉粥样硬化、呼吸道疾病、妊娠性高血压等有着密切关系.

  8. Antiangiogenic Effects of VH02, a Novel Urea Derivative: In Vitro and in Vivo Studies

    Directory of Open Access Journals (Sweden)

    Suwadee Phowichit

    2016-09-01

    Full Text Available Vascular endothelial growth factor receptor 2 (VEGFR2 is a vital target for therapeutic intervention in cancer. We have recently described a computer-based drug design for a small molecule VEGFR2 inhibitor named VH02 (1-((1-(1H-indazol-6-yl-1H-1,2,3-triazol-4-ylmethyl-3-(3-chloromethylphenylurea. This study aimed to further explore the anti-angiogenic activity of VH02 both in vitro and in vivo. The in vitro assays include cell viability, capillary-like tube formation, MMP activity, and western blot analyses of signaling through VEGFR2 while the in vivo anti-angiogenic response were performed to evaluate the effect on vascularization in Matrigel plug applied in C57BL/6L mice. VH02 reduced angiogenesis behavior of EA.hy926 including cell viability, migration, adhesion, capillary-like tube formation, and MMP-2 activity induced by VEGF. Furthermore, VH02 regulated angiogenesis by directly inhibiting VEGFR2 on Tyr1175 signaling pathway leading to the inhibition of Akt-mediated cell survival and migration. Disruption of phosphorylation at VEGFR2-Tyr1175 by VH02 abolished FAK-Tyr397 signaling but not phosphorylation of p38 MAPK. This suggests that blockade of FAK by VH02 apparently associated with reduction of endothelial cell motility. Actin cytoskeleton rearrangement was diminished by VH02 in human endothelial cells. The anti-angiogenic effect of VH02 was confirmed in the in vivo model, revealing the reduction of vascular density in Matrigel plug after VH02 treatment. Additionally, the pericyte-like cells surrounding blood vessels in the plugs were significantly reduced as well as vascular density and p-Akt intensity. Our findings indicate that VH02 successfully inhibits VEGF-induced angiogenesis both in vitro and in vivo models. The compound could be further developed as an antiangiogenesis agent for cancer therapy.

  9. Autocrine VEGF isoforms differentially regulate endothelial cell behavior

    Directory of Open Access Journals (Sweden)

    Hideki Yamamoto

    2016-09-01

    Full Text Available Vascular endothelial growth factor A (VEGF is involved in all the essential biology of endothelial cells, from proliferation to vessel function, by mediating intercellular interactions and monolayer integrity. It is expressed as three major alternative spliced variants. In mice, these are VEGF120, VEGF164, and VEGF188, each with different affinities for extracellular matrices and cell surfaces, depending on the inclusion of heparin-binding sites, encoded by exons 6 and 7. To determine the role of each VEGF isoform in endothelial homeostasis, we compared phenotypes of primary endothelial cells isolated from lungs of mice expressing single VEGF isoforms in normoxic and hypoxic conditions. The differential expression and distribution of VEGF isoforms affect endothelial cell functions, such as proliferation, adhesion, migration and integrity, which are dependent on the stability of and affinity to VEGF receptor 2 (VEGFR2. We found a correlation between autocrine VEGF164 and VEGFR2 stability, which is also associated with increased expression of proteins involved in cell adhesion. Endothelial cells expressing only VEGF188, which localizes to extracellular matrices or cell surfaces, presented a mesenchymal morphology and weakened monolayer integrity. Cells expressing only VEGF120 lacked stable VEGFR2 and dysfunctional downstream processes, rendering the cells unviable. Endothelial cells expressing these different isoforms in isolation also had differing rates of apoptosis, proliferation, and signaling via nitric oxide (NO synthesis. These data indicate that autocrine signaling of each VEGF isoform has unique functions on endothelial homeostasis and response to hypoxia, due to both distinct VEGF distribution and VEGFR2 stability, which appears to be, at least partly, affected by differential NO production. This study demonstrates that each autocrine VEGF isoform has a distinct effect on downstream functions, namely VEGFR2-regulated endothelial cell

  10. Effective treatment of diverse medulloblastoma models with mebendazole and its impact on tumor angiogenesis

    Science.gov (United States)

    Bai, Ren-Yuan; Staedtke, Verena; Rudin, Charles M.; Bunz, Fred; Riggins, Gregory J.

    2015-01-01

    Background Medulloblastoma is the most common malignant brain tumor in children. Current standard treatments cure 40%–60% of patients, while the majority of survivors suffer long-term neurological sequelae. The identification of 4 molecular groups of medulloblastoma improved the clinical management with the development of targeted therapies; however, the tumor acquires resistance quickly. Mebendazole (MBZ) has a long safety record as antiparasitic in children and has been recently implicated in inhibition of various tyrosine kinases in vitro. Here, we investigated the efficacy of MBZ in various medulloblastoma subtypes and MBZ's impact on vascular endothelial growth factor receptor 2 (VEGFR2) and tumor angiogenesis. Methods The inhibition of MBZ on VEGFR2 kinase was investigated in an autophosphorylation assay and a cell-free kinase assay. Mice bearing orthotopic PTCH1-mutant medulloblastoma allografts, a group 3 medulloblastoma xenograft, and a PTCH1-mutant medulloblastoma with acquired resistance to the smoothened inhibitor vismodegib were treated with MBZ. The survival benefit and the impact on tumor angiogenesis and VEGFR2 kinase function were analyzed. Results We determined that MBZ interferes with VEGFR2 kinase by competing with ATP. MBZ selectively inhibited tumor angiogenesis but not the normal brain vasculatures in orthotopic medulloblastoma models and suppressed VEGFR2 kinase in vivo. MBZ significantly extended the survival of medulloblastoma models derived from different molecular backgrounds. Conclusion Our findings support testing of MBZ as a possible low-toxicity therapy for medulloblastomas of various molecular subtypes, including tumors with acquired vismodegib resistance. Its antitumor mechanism may be partially explained by inhibition of tumor angiogenesis. PMID:25253417

  11. The Accumulation of VEGFA in the Glomerular Basement Membrane and Its Relationship with Podocyte Injury and Proteinuria in Alport Syndrome.

    Science.gov (United States)

    Wang, Haiyan; Yue, Zhihui; Wu, Jinlang; Liu, Ting; Mo, Ying; Jiang, Xiaoyun; Sun, Liangzhong

    2015-01-01

    The pathogenesis of proteinuria in Alport syndrome (AS) remains unclear. Vascular endothelial growth factor A (VEGFA) is a key regulator of the glomerular filtration barrier (GFB). This study explored the expression of VEGFA in the glomeruli and its accumulation in the glomerular basement membrane (GBM) and their relationship with podocyte injury and proteinuria in Alport syndrome (AS). Clinical data and renal tissues of control patients (11 cases) and AS patients (25 cases) were included. AS patients were further divided into 2 groups according to the quantities of their urinary protein: mild to moderate proteinuria group (proteinuria proteinuria group (proteinuria ≥50 mg/kg/d, 10 cases). The expression and distribution of VEGFA and VEGF receptor 2 (VEGFR2) in the GFB, the phosphorylation of VEGFR2 (p-VEGFR2) and nephrin (p-nephrin), and the expression of synaptopodin and nephrin in the glomeruli were detected by immune electron microscopy and/or immunofluorescence, and their relationships to proteinuria in AS patients were analyzed. The accumulation of VEGFA in the GBM was increased in AS patients. The expression of VEGFA and the levels of p-VEGFR2 and p-nephrin in glomeruli were increased and were positively correlated with the degree of proteinuria in AS patients. The expression of synaptopodin and nephrin were decreased and were negatively correlated with the degree of proteinuria in AS patients. The over expressed VEGFA in the glomeruli and its accumulation in the GBM may activate the VEGFA-VEGFR2 and nephrin signaling pathways and lead to podocyte injury and occurrence of proteinuria in AS.

  12. Acute Pyelonephritis during Pregnancy Changes the Balance of Angiogenic and Anti-Angiogenic Factors in Maternal Plasma

    Science.gov (United States)

    Chaiworapongsa, Tinnakorn; Romero, Roberto; Gotsch, Francesca; Kusanovic, Juan Pedro; Mittal, Pooja; Kim, Sun Kwon; Erez, Offer; Vaisbuch, Edi; Mazaki-Tovi, Shali; Kim, Chong Jai; Dong, Zhong; Yeo, Lami; Hassan, Sonia S

    2012-01-01

    Objective Angiogenic factors have been implicated in the pathophysiology of sepsis. In experimental models of sepsis (endotoxemia and/or cecal ligation puncture), there is increased expression of vascular endothelial growth factors (VEGF) and the administration of exogenous soluble VEGF receptor (sVEGFR)-1, an antagonist to VEGF, reduces morbidity and mortality. Moreover, a dramatic elevation in sVEGFR-1 has been demonstrated in human sepsis. Although a balance between angiogenic and anti-angiogenic factors is essential for feto-placental development, the changes of angiogenic factors during pregnancy in the context of infection have never been explored. Angiogenic factors also play crucial roles in the pathophysiology of preeclampsia. This study was conducted to determine if maternal plasma concentrations of placental growth factor (PlGF), sVEGFR-2 and soluble endoglin (sEng) change in pregnancies complicated by acute pyelonephritis (AP) compared to normal pregnancy and preeclampsia (PE). Study Design A case-control study was conducted in patients with AP, normal pregnant women (NP) and patients with PE (n=36 for each group) matched for gestational age. AP was diagnosed in the presence of fever (temperature ≥ 38°C), clinical signs of infection, and a positive urine culture for micro-organisms. Plasma concentrations of PlGF, sVEGFR-2 and sEng were determined by ELISA. The results of plasma sVEGFR-1 concentrations has previously been reported before, but were included in this study to provide a complete picture of the angiogenic/anti-angiogenic profiles. Serum concentrations of interleukin (IL)-1β, IL-2, IL-4, IL-5, IL-6, IL-7, IL-8, IL-10, IL-12p70, IL-13, interferon (IFN)-γ, Granulocyte macrophage colony stimulating factor (GM-CSF), and tumor necrosis factor (TNF)-α were also determined using high sensitivity multiplexed immunoassays in patients with AP and NP. Results AP was associated with a lower median plasma concentration of PlGF and sVEGFR-2 than NP

  13. Inhibition of VEGF-dependent angiogenesis by the anti-CD82 monoclonal antibody 4F9 through regulation of lipid raft microdomains.

    Science.gov (United States)

    Nomura, Sayaka; Iwata, Satoshi; Hatano, Ryo; Komiya, Eriko; Dang, Nam H; Iwao, Noriaki; Ohnuma, Kei; Morimoto, Chikao

    2016-05-20

    CD82 (also known as KAI1) belongs to the tetraspanin superfamily of type III transmembrane proteins, and is involved in regulating cell adhesion, migration and proliferation. In contrast to these well-established roles of CD82 in tumor biology, its function in endothelial cell (EC) activity and tumor angiogenesis is yet to be determined. In this study, we show that suppression of CD82 negatively regulates vascular endothelial growth factor (VEGF)-induced angiogenesis. Moreover, we demonstrate that the anti-CD82 mAb 4F9 effectively inhibits phosphorylation of VEGF receptor 2 (VEGFR2), which is the principal mediator of the VEGF-induced angiogenic signaling process in tumor angiogenesis, by regulating the organization of the lipid raft microdomain signaling platform in human EC. Our present work therefore suggests that CD82 on EC is a potential target for anti-angiogenic therapy in VEGFR2-dependent tumor angiogenesis.

  14. Metformin inhibits development of diabetic retinopathy through inducing alternative splicing of VEGF-A

    Science.gov (United States)

    Yi, Quan-Yong; Deng, Gang; Chen, Nan; Bai, Zhi-Sha; Yuan, Jian-Shu; Wu, Guo-Hai; Wang, Yu-Wen; Wu, Shan-Jun

    2016-01-01

    Previous studies have shown that metformin, an AMP-activated protein kinase activator widely prescribed for type 2 diabetes, is especially beneficial in cases of diabetic retinopathy (DR) with undetermined mechanisms. Here, we used a streptozotocin-induced diabetes model in mice to study the effects of metformin on the development of DR. We found that 10 weeks after STZ treatment, DR was induced in STZ-treated mice, regardless treatment of metformin. However, metformin alleviated the DR, seemingly through attenuating the retina neovascularization. The total vascular endothelial cell growth factor A (VEGF-A) in eyes was not altered by metformin, but the phosphorylation of the VEGF receptor 2 (VEGFR2) was decreased, which inhibited VEGF signaling. Further analysis showed that metformin may induce VEGF-A mRNA splicing to VEGF120 isoform to reduce its activation of the VEGFR2. These findings are critical for generating novel medicine for DR treatment.

  15. Blockade of Toll-like receptor 2 prevents spontaneous cytokine release from rheumatoid arthritis ex vivo synovial explant cultures

    LENUS (Irish Health Repository)

    Nic An Ultaigh, Sinead

    2011-02-23

    Abstract Introduction The aim of this study was to examine the effect of blocking Toll-like receptor 2 (TLR2) in rheumatoid arthritis (RA) synovial cells. Methods RA synovial tissue biopsies, obtained under direct visualization at arthroscopy, were established as synovial explant cultures ex vivo or snap frozen for immunohistology. Mononuclear cell cultures were isolated from peripheral blood and synovial fluid of RA patients. Cultures were incubated with the TLR1\\/2 ligand, Pam3CSK4 (200 ng, 1 and 10 μg\\/ml), an anti-TLR2 antibody (OPN301, 1 μg\\/ml) or an immunoglobulin G (IgG) (1 μg\\/ml) matched control. The comparative effect of OPN301 and adalimumab (anti-tumour necrosis factor alpha) on spontaneous release of proinflammatory cytokines from RA synovial explants was determined using quantitative cytokine MSD multiplex assays or ELISA. OPN301 penetration into RA synovial tissue explants cultures was assessed by immunohistology. Results Pam3CSK4 significantly upregulated interleukin (IL)-6 and IL-8 in RA peripheral blood mononuclear cells (PBMCs), RA synovial fluid mononuclear cells (SFMCs) and RA synovial explant cultures (P < 0.05). OPN301 significantly decreased Pam3CSK4-induced cytokine production of tumour necrosis factor alpha (TNF-α), IL-1β, IL-6, interferon (IFN)-γ and IL-8 compared to IgG control in RA PBMCs and SFMCs cultures (all P < 0.05). OPN301 penetration of RA synovial tissue cultures was detected in the lining layer and perivascular regions. OPN301 significantly decreased spontaneous cytokine production of TNF-α, IL-1β, IFN-γ and IL-8 from RA synovial tissue explant cultures (all P < 0.05). Importantly, the inhibitory effect of OPN on spontaneous cytokine secretion was comparable to inhibition by anti-TNFα monoclonal antibody adalimumab. Conclusions These findings further support targeting TLR2 as a potential therapeutic agent for the treatment of RA.

  16. Hepatitis C virus core protein induces fibrogenic actions of hepatic stellate cells via toll-like receptor 2.

    Science.gov (United States)

    Coenen, Martin; Nischalke, Hans Dieter; Krämer, Benjamin; Langhans, Bettina; Glässner, Andreas; Schulte, Daniela; Körner, Christian; Sauerbruch, Tilman; Nattermann, Jacob; Spengler, Ulrich

    2011-09-01

    Hepatic stellate cells (HSCs) represent the main fibrogenic cell type accumulating extracellular matrix in the liver. Recent data suggest that hepatitis C virus (HCV) core protein may directly activate HSCs. Therefore, we examined the influence of recombinant HCV core protein on human HSCs. Primary human HSCs and the human HSC line LX-2 were stimulated with recombinant HCV proteins core and envelope 2 protein. Expression of procollagen type I α-1, α-smooth muscle actin, cysteine- and glycine-rich protein 2, glial fibrillary acidic protein, tissue growth factor β1, matrix metalloproteinases 2 (MMP2) and 13, tissue inhibitor of metalloproteinases 1 and 2 was investigated by real-time PCR. Intracellular signaling pathways of ERK1/2, p38 and, jun-amino-terminal kinase (JNK) were analyzed by western blot analysis. Recombinant HCV core protein induced upregulation of procollagen type I α-1, α-smooth muscle actin, MMP 2 and 13, tissue inhibitor of metalloproteinases 1 and 2, tissue growth factor β1, cysteine- and glycine-rich protein 2, and glial fibrillary acidic protein mRNA expression, whereas HCV envelope 2 protein did not exert any significant effect. Blocking of toll-like receptor 2 (TLR2) with a neutralizing antibody prevented mRNA upregulation by HCV core protein confirming that the TLR2 pathway was involved. Furthermore, western blot analysis revealed HCV-induced phosphorylation of the TLR2-dependent signaling molecules ERK1/2, p38 and JNK mitogen-activated kinases. Our in vitro results demonstrate a direct effect of HCV core protein on activation of HSCs toward a profibrogenic state, which is mediated via the TLR2 pathway. Manipulating the TLR2 pathway may thus provide a new approach for antifibrotic therapies in HCV infection.

  17. Inhibition of titanium particle-induced inflammatory osteolysis through inactivation of cannabinoid receptor 2 by AM630.

    Science.gov (United States)

    Geng, D C; Xu, Y Z; Yang, H L; Zhu, X S; Zhu, G M; Wang, X B

    2010-10-01

    Wear particle could induce inflammatory osteolysis and is the primary pathological factor for aseptic loosening. Although it is known that cannabinoid receptor 2 (CB2) inhibits osteoclast differentiation, the effect on inflammatory osteolysis induced by wear particles remains unclear. This study examined the effect of CB2 in the regulation of osteoclast differentiation in a murine macrophage cell line (RAW264.7), which has been shown to be stimulated by titanium (Ti) particles and receptor activator of the NF-kappaB ligand (RANKL). Results showed that CB2 expression in RAW cells cultured with Ti particles and RANKL. CB2 inactivation by AM630, a CB2 selective antagonist, effectively inhibited osteoclastogenesis in the differentiation medium system. AM630 treatment (> or =100 nM) significantly reduced the number of tartrate-resistant acid phosphatase-positive cells when compared with the control. Real-time reverse transcription polymerase chain reaction analysis revealed that AM630 (100 nM) inhibited mRNA expression of RANK and cathepsin K in RAW cells stimulated by Ti particles and RANKL. Moreover, enzyme-linked immunosorbent assay showed that AM630 (100 nM) reduced protein expression of interleukin-1beta and tumor necrosis factor-alpha in RAW cells cultured with Ti particles. In addition, 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazoliumbromide revealed that AM630 had no toxic effect on RAW cells. These results suggested that CB2 inactivation by AM630 could provide a promising therapeutic target for treating or preventing aseptic loosening.

  18. The anti-angiogenic role of discoidin domain receptor 2 (DDR2) in laser-induced choroidal neovascularization.

    Science.gov (United States)

    Zhu, Tong; Zhu, Jie; Bu, Xin; Zhao, Hu; Zhang, Shuya; Chang, Yuan; Li, Rong; Yao, Libo; Wang, Yusheng; Su, Jin

    2015-02-01

    Choroidal neovascularization (CNV), an aberrant growth of blood vessels in the choroid layer of the eye, is a major cause of vision loss. In view of our recent finding that discoidin domain receptor 2 (DDR2), a collagen-binding receptor tyrosine kinase, is involved in control of vascular endothelial activity and tumor angiogenesis, the present study aims to investigate whether and how DDR2 affects the pathogenesis of CNV. We initially found that a spontaneous DDR2 mutant mouse colony (slie) exhibited enhanced amplitude of laser-induced CNV. The inhibitory role of DDR2 in CNV development was further confirmed by experiments through intravitreous injection of DDR2 small interference RNA (siRNA) or DDR2-expressing adenovirus. Quantitative real-time polymerase chain reaction (qPCR) and immunoblot analysis showed that DDR2 regulates the expression of several major pro-angiogenic factors in the laser-injured choroid as well as in retinal pigment epithelium (RPE) cells. In addition, it was demonstrated that the CNV-induced increases in the phosphorylation levels of Akt and mTOR were affected by the upregulation or downregulation of DDR2. Thus, the data from this study for the first time revealed that DDR2 negatively regulates the development of experimental CNV in vivo, which may provide a novel target for preventing human pathological ocular neovascularization. Key messages: DDR2 does not affect retinal development. DDR2 inhibits laser-induced CNV. DDR2 regulates angiogenic factor expression in CNV lesion as well as in RPE cells. DDR2 is involved in modulation of CNV-induced activation of PI3K pathway.

  19. Sequence analysis of the Toll-like receptor 2 gene of old world camels

    Directory of Open Access Journals (Sweden)

    Shyam S. Dahiya

    2014-11-01

    Full Text Available The Toll-like receptor 2 (TLR2 gene of old world camels (Camelus dromedarius and Camelus bactrianus was cloned and sequenced. The TLR2 gene of the dromedary camel had the highest nucleotide and amino acid identity with pig, i.e., 66.8% and 59.6%, respectively. Similarly, the TLR2 gene of the Bactrian camel also had the highest nucleotide and amino acid identity with pig, i.e., 85.7% and 81.4%, respectively. Dromedary and Bactrian camels shared 77.9% nucleotide and 73.6% amino acid identity with each other. Interestingly, the amidation motif is present in camel (Dromedary and Bactrian TLR2 only, and the TIR domain is absent in Dromedary camel TLR2. This is the first report of the TLR2 gene sequence of Dromedary and Bactrian camels.

  20. Combining Elements from Two Antagonists of Formyl Peptide Receptor 2 Generates More Potent Peptidomimetic Antagonists.

    Science.gov (United States)

    Skovbakke, Sarah Line; Holdfeldt, André; Nielsen, Christina; Hansen, Anna Mette; Perez-Gassol, Iris; Dahlgren, Claes; Forsman, Huamei; Franzyk, Henrik

    2017-08-24

    Structural optimization of a peptidomimetic antagonist of formyl peptide receptor 2 (FPR2) was explored by an approach involving combination of elements from the two most potent FPR2 antagonists described: a Rhodamine B-conjugated 10-residue gelsonin-derived peptide (i.e., PBP10, RhB-QRLFQVKGRR-OH) and the palmitoylated α-peptide/β-peptoid hybrid Pam-(Lys-βNspe)6-NH2. This generated an array of hybrid compounds from which a new subclass of receptor-selective antagonists was identified. The most potent representatives displayed activity in the low nanomolar range. The resulting stable and potent FPR2-selective antagonists (i.e., RhB-(Lys-βNphe)n-NH2; n = 4-6) are expected to become valuable tools in further elucidation of the physiological role of FPR2 in health and disease.

  1. Peripheral Galanin Receptor 2 as a Target for the Modulation of Pain

    Directory of Open Access Journals (Sweden)

    Richard P. Hulse

    2012-01-01

    Full Text Available The neuropeptide galanin is widely expressed in the nervous system and has an important role in nociception. It has been shown that galanin can facilitate and inhibit nociception in a dose-dependent manner, principally through the central nervous system, with enhanced antinociceptive actions after nerve injury. However, following nerve injury, expression of galanin within the peripheral nervous system is dramatically increased up to 120-fold. Despite this striking increase in the peripheral nervous system, few studies have investigated the role that galanin plays in modulating nociception at the primary afferent nociceptor. Here, we summarise the recent work supporting the role of peripherally expressed galanin with particular reference to the dual actions of the galanin receptor 2 in neuropathic pain highlighting this as a potential target analgesic.

  2. Placental growth factor is a potent vasodilator of rat and human resistance arteries.

    Science.gov (United States)

    Osol, George; Celia, Gerard; Gokina, Natalia; Barron, Carolyn; Chien, Edward; Mandala, Maurizio; Luksha, Leonid; Kublickiene, Karolina

    2008-03-01

    The objectives of this study were to determine whether placental growth factor (PlGF) exerts a vasodilatory effect on rat uterine vessels (arcuate arteries and veins) and to examine regional differences in reactivity by comparing these responses to those of comparably sized mesenteric vessels. We also sought to examine and compare its effects on human uterine and subcutaneous vessels. All vessels were studied in vitro, under pressurized (rat) or isometric wire-mounted (human) conditions, and exposed to a range of PlGF concentrations. Inhibitors of nitric oxide and prostaglandin synthesis were included in an effort to understand the causal mechanism(s). In rat uterine arteries, the effects of receptor inhibition and activation using selective ligands for VEGFR-1 (PlGF) vs. VEGFR-2 (VEGF-E) were determined, and real-time RT-PCR was performed to evaluate the effect of pregnancy on relative abundance of VEGFR-1 and VEGFR-2 message in the vascular wall. PlGF was a potent vasodilator of all vessels studied, with greatest sensitivity observed in rat uterine arteries. Pregnancy significantly augmented dilator sensitivity to PlGF, and this effect was associated with selective upregulation of VEGFR-1 message in the pregnant state. The contribution of nitric oxide was appreciable in rat and human uterine arteries, with lesser effects in rat uterine veins and mesenteric arteries, and with no observable effect in human subcutaneous vessels. Based on these results, we conclude that PlGF is a potent vasodilator of several vessel types in both humans and rats. Its potency and mechanism vary with physiological state and vessel location and are mediated solely by the VEGFR-1 receptor subtype. Gestational changes in the uterine circulation suggest that this factor may play a role in modulating uterine vascular remodeling and blood flow during the pregnant state.

  3. Discoidin domain receptor 2 (DDR2) regulates proliferation of endochondral cells in mice

    Energy Technology Data Exchange (ETDEWEB)

    Kawai, Ikuma; Hisaki, Tomoka; Sugiura, Koji; Naito, Kunihiko [Laboratory of Applied Genetics, Graduate School of Agricultural and Life Science, University of Tokyo, Tokyo 113-8657 (Japan); Kano, Kiyoshi, E-mail: kanokiyo@yamaguchi-u.ac.jp [Laboratory of Developmental Biology, Joint Faculty of Veterinary Medicine, Yamaguchi University, Yamaguchi 753-8515, Japan. (Japan); Biomedical Science Center for Translational Research (BSCTR), The United Graduate School of Veterinary Science, Yamaguchi University, Yamaguchi 753-8515 (Japan)

    2012-10-26

    Highlights: Black-Right-Pointing-Pointer Discoidin domain receptor 2 (DDR2) is a receptor tyrosine kinase. Black-Right-Pointing-Pointer DDR2 regulates cell proliferation, cell adhesion, migration, and extracellular matrix remodeling. Black-Right-Pointing-Pointer We produced in vitro and in vivo model to better understand the role of DDR2. Black-Right-Pointing-Pointer DDR2 might play an inhibitory role in the proliferation of chondrocyte. -- Abstract: Discoidin domain receptor 2 (DDR2) is a receptor tyrosine kinase that is activated by fibrillar collagens. DDR2 regulates cell proliferation, cell adhesion, migration, and extracellular matrix remodeling. The decrement of endogenous DDR2 represses osteoblastic marker gene expression and osteogenic differentiation in murine preosteoblastic cells, but the functions of DDR2 in chondrogenic cellular proliferation remain unclear. To better understand the role of DDR2 signaling in cellular proliferation in endochondral ossification, we inhibited Ddr2 expression via the inhibitory effect of miRNA on Ddr2 mRNA (miDdr2) and analyzed the cellular proliferation and differentiation in the prechondrocyte ATDC5 cell lines. To investigate DDR2's molecular role in endochondral cellular proliferation in vivo, we also produced transgenic mice in which the expression of truncated, kinase dead (KD) DDR2 protein is induced, and evaluated the DDR2 function in cellular proliferation in chondrocytes. Although the miDdr2-transfected ATDC5 cell lines retained normal differentiation ability, DDR2 reduction finally promoted cellular proliferation in proportion to the decreasing ratio of Ddr2 expression, and it also promoted earlier differentiation to cartilage cells by insulin induction. The layer of hypertrophic chondrocytes in KD Ddr2 transgenic mice was not significantly thicker than that of normal littermates, but the layer of proliferative chondrocytes in KD-Ddr2 transgenic mice was significantly thicker than that of normal littermates

  4. Streptococcus gordonii induces nitric oxide production through its lipoproteins stimulating Toll-like receptor 2 in murine macrophages.

    Science.gov (United States)

    Kim, Hyun Young; Baik, Jung Eun; Ahn, Ki Bum; Seo, Ho Seong; Yun, Cheol-Heui; Han, Seung Hyun

    2017-02-01

    Streptococcus gordonii, a Gram-positive commensal in the oral cavity, is an opportunistic pathogen that can cause endodontic and systemic infections resulting in infective endocarditis. Lipoteichoic acid (LTA) and lipoprotein are major virulence factors of Gram-positive bacteria that are preferentially recognized by Toll-like receptor 2 (TLR2) on immune cells. In the present study, we investigated the effect of S. gordonii LTA and lipoprotein on the production of the representative inflammatory mediator nitric oxide (NO) by the mouse macrophages. Heat-killed S. gordonii wild-type and an LTA-deficient mutant (ΔltaS) but not a lipoprotein-deficient mutant (Δlgt) induced NO production in mouse primary macrophages and the cell line, RAW 264.7. S. gordonii wild-type and ΔltaS also induced the expression of inducible NO synthase (iNOS) at the mRNA and protein levels. In contrast, the Δlgt mutant showed little effect under the same condition. Furthermore, S. gordonii wild-type and ΔltaS induced NF-κB activation, STAT1 phosphorylation, and IFN-β expression, which are important for the induction of iNOS gene expression, with little activation by Δlgt. S. gordonii wild-type and ΔltaS showed an increased adherence and internalization to RAW 264.7 cells compared to Δlgt. In addition, S. gordonii wild-type and ΔltaS, but not Δlgt, substantially increased TLR2 activation while none of these induced NO production in TLR2-deficient macrophages. Triton X-114-extracted lipoproteins from S. gordonii were sufficient to induce NO production. Collectively, we suggest that lipoprotein is an essential cell wall component of S. gordonii to induce NO production in macrophages through TLR2 triggering NF-κB and STAT1 activation. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. PLACENTAL GROWTH FACTOR (PlGF) IS A POTENT VASODILATOR OF RAT AND HUMAN RESISTANCE ARTERIES

    Science.gov (United States)

    Osol, George; Celia, Gerard; Gokina, Natalia; Barron, Carolyn; Chien, Edward; Mandala, Maurizio; Luksha, Leonid; Kublickiene, Karolina

    2010-01-01

    The objectives of this study were to determine whether PlGF exerts a vasodilatory effect on rat uterine vessels (arcuate arteries and veins) and to examine regional differences in reactivity by comparing these responses to those of comparably-sized mesenteric vessels. We also sought to examine and compare its effects on human uterine and subcutaneous vessels. All vessels were studied in vitro, under pressurized (rat) or isometric wire-mounted (human) conditions, and exposed to a range of PlGF concentrations. Inhibitors of nitric oxide and prostaglandin synthesis were included in an effort to understand the causal mechanism(s). In rat uterine arteries, the effects of receptor inhibition and activation using selective ligands for VEGFR-1 (PlGF) vs. VEGFR-2 (VEGF-E) were determined, and real-time RT-PCR was performed to evaluate the effect of pregnancy on relative abundance of VEGFR-1 and VEGFR-2 message in the vascular wall. PlGF was a potent vasodilator of all vessels studied, with greatest sensitivity observed in rat uterine arteries. Pregnancy significantly augmented dilator sensitivity to PlGF, and this effect was associated with selective upregulation of VEGFR-1 message in the pregnant state. The contribution of nitric oxide was appreciable in rat and human uterine arteries, with lesser effects in rat uterine veins and mesenteric arteries, and with no observable effect in human subcutaneous vessels. Based on these results, we conclude that PlGF is a potent vasodilator of several vessel types in both humans and rats. Its potency and mechanism varies with physiological state and vessel location, and is mediated solely by the VEGFR-1 receptor subtype. Gestational changes in the uterine circulation suggest that this factor may play a role in modulating uterine vascular remodeling and blood flow during the pregnant state. PMID:18192215

  6. Coordinated vascular endothelial growth factor expression and signaling during skeletal myogenic differentiation.

    Science.gov (United States)

    Bryan, Brad A; Walshe, Tony E; Mitchell, Dianne C; Havumaki, Josh S; Saint-Geniez, Magali; Maharaj, Arindel S; Maldonado, Angel E; D'Amore, Patricia A

    2008-03-01

    Angiogenesis is largely controlled by hypoxia-driven transcriptional up-regulation and secretion of vascular endothelial growth factor (VEGF) and its binding to the endothelial cell tyrosine receptor kinases, VEGFR1 and VEGFR2. Recent expression analysis suggests that VEGF is expressed in a cell-specific manner in normoxic adult tissue; however, the transcriptional regulation and role of VEGF in these tissues remains fundamentally unknown. In this report we demonstrate that VEGF is coordinately up-regulated during terminal skeletal muscle differentiation. We reveal that this regulation is mediated in part by MyoD homo- and hetero-dimeric transcriptional mechanisms. Serial deletions of the VEGF promoter elucidated a region containing three tandem CANNTG consensus MyoD sites serving as essential sites of direct interaction for MyoD-mediated up-regulation of VEGF transcription. VEGF-null embryonic stem (ES) cells exhibited reduced myogenic differentiation compared with wild-type ES cells, suggesting that VEGF may serve a role in skeletal muscle differentiation. We demonstrate that VEGFR1 and VEGFR2 are expressed at low levels in myogenic precursor cells and are robustly activated upon VEGF stimulation and that their expression is coordinately regulated during skeletal muscle differentiation. VEGF stimulation of differentiating C2C12 cells promoted myotube hypertrophy and increased myogenic differentiation, whereas addition of sFlt1, a VEGF inhibitor, resulted in myotube hypotrophy and inhibited myogenic differentiation. We further provide evidence indicating VEGF-mediated myogenic marker expression, mitogenic activity, migration, and prosurvival functions may contribute to increased myogenesis. These data suggest a novel mechanism whereby VEGF is coordinately regulated as part of the myogenic differentiation program and serves an autocrine function regulating skeletal myogenesis.

  7. Pattern of hormone receptors and human epidermal growth factor ...

    African Journals Online (AJOL)

    2015-02-05

    Feb 5, 2015 ... Key words: Breast cancer, human epidermal growth factor receptor 2/neu, immunohistochemistry, ... therapy.[6‑8] Of all these prognostic and predictive factors, ... one of the biggest private medical laboratories in Nigeria.

  8. Placenta growth factor-1 antagonizes VEGF-induced angiogenesis and tumor growth by the formation of functionally inactive PIGF-1/VEGF heterodimers

    DEFF Research Database (Denmark)

    Eriksson, A.; Cao, R.; Pawliuk, R.

    2002-01-01

    , the biological function of its related homolog, placenta growth factor (PlGF), is poorly understood. Here we demonstrate that PlGF-1, an alternatively spliced isoform of the PlGF gene, antagonizes VEGF-induced angiogenesis when both factors are coexpressed in murine fibrosarcoma cells. Overexpression of PlGF-1...... in VEGF-producing tumor cells results in the formation of PlGF-1/VEGF heterodimers and depletion of the majority of mouse VEGF homodimers. The heterodimeric form of PlGF-1/VEGF lacks the ability to induce angiogenesis in vitro and in vivo. Similarly, PlGF-1/VEGF fails to activate the VEGFR-2-mediated...... signaling pathways. Further, PlGF-1 inhibits the growth of a murine fibrosarcoma by approximately 90% when PlGF-1-expressing tumor cells are implanted in syngeneic mice. In contrast, overexpression of human VEGF in murine tumor cells causes accelerated and exponential growth of primary fibrosarcomas...

  9. SPLUNC1 regulation in airway epithelial cells: role of toll-like receptor 2 signaling

    Directory of Open Access Journals (Sweden)

    Smith Sean

    2010-11-01

    Full Text Available Abstract Background Respiratory infections including Mycoplasma pneumoniae (Mp contribute to various chronic lung diseases. We have shown that mouse short palate, lung, and nasal epithelium clone 1 (SPLUNC1 protein was able to inhibit Mp growth. Further, airway epithelial cells increased SPLUNC1 expression upon Mp infection. However, the mechanisms underlying SPLUNC1 regulation remain unknown. In the current study, we investigated if SPLUNC1 production following Mp infection is regulated through Toll-like receptor 2 (TLR2 signaling. Methods Airway epithelial cell cultures were utilized to reveal the contribution of TLR2 signaling including NF-κB to SPLUNC1 production upon bacterial infection and TLR2 agonist stimulation. Results Mp and TLR2 agonist Pam3CSK4 increased SPLUNC1 expression in tracheal epithelial cells from wild type, but not TLR2-/- BALB/c mice. RNA interference (short-hairpin RNA of TLR2 in normal human bronchial epithelial cells under air-liquid interface cultures significantly reduced SPLUNC1 levels in Mp-infected or Pam3CSK4-treated cells. Inhibition and activation of NF-κB pathway decreased and increased SPLUNC1 production in airway epithelial cells, respectively. Conclusions Our data for the first time suggest that airway epithelial TLR2 signaling is pivotal in mycoplasma-induced SPLUNC1 production, thus improving our understanding of the aberrant SPLUNC1 expression in airways of patients suffering from chronic lung diseases with bacterial infections.

  10. Polymorphisms of toll-like receptor 2 and 4 genes in Chagas disease

    Directory of Open Access Journals (Sweden)

    German Zafra

    2008-02-01

    Full Text Available The aim of this study was to test the possible implication of toll-like receptor 2 (TLR2 and TLR4 gene polymorphisms in determining the susceptibility to Chagas' disease. Genotypes were determined by polymerase chain reaction-restriction fragment length polymorphism in 475 individuals from Colombia, 143 seropositive with chagasic cardiomyopathy, 132 seropositive asymptomatic and 200 seronegative. The TLR2 arginine to glutamine substitution at residue 753(Arg753Gln polymorphism was absent in the groups analyzed. The TLR4 Asp299Gly and Thr399Ile polymorphisms are in linkage disequilibrium and we observed a very low frequency of these polymorphisms in our study population (2.6% and 1.8% respectively. The overall TLR2 and TLR4 alleles and genotype distribution in seronegative and seropositive were not significantly different. We compared the frequencies between asymptomatic patients and those with chagasic cardiomyopathy and we did not observe any significant differences in the distribution of alleles or genotypes. In summary, this study corroborates the low frequency of TLR2 and TLR4 polymorphisms observed in other populations and suggest that these do not play an important role in Chagas' disease. The validation of these findings in independent cohorts is needed to firmly establish a role for TLR2 and TLR4 variants in Chagas' disease.

  11. Treponema denticola activates mitogen-activated protein kinase signal pathways through Toll-like receptor 2.

    Science.gov (United States)

    Ruby, John; Rehani, Kunal; Martin, Michael

    2007-12-01

    Treponema denticola, a spirochete indigenous to the oral cavity, is associated with host inflammatory responses to anaerobic polymicrobial infections of the root canal, periodontium, and alveolar bone. However, the cellular mechanisms responsible for the recognition of T. denticola by the innate immune system and the underlying cell signaling pathways that regulate the inflammatory response to T. denticola are currently unresolved. In this study, we demonstrate that T. denticola induces innate immune responses via the utilization of Toll-like receptor 2 (TLR2) but not TLR4. Assessment of TLR2/1 and TLR2/6 heterodimers revealed that T. denticola predominantly utilizes TLR2/6 for the induction of cellular responses. Analysis of the mitogen-activated protein kinase (MAPK) signaling pathway in T. denticola-stimulated monocytes identified a prolonged up-regulation of the MAPK extracellular signal-related kinase 1/2 (ERK1/2) and p38, while no discernible increase in phospho-c-Jun N-terminal kinase 1/2 (JNK1/2) levels was observed. With the aid of pharmacological inhibitors selectively targeting ERK1/2 via the mitogen-activated protein kinase/extracellular signal-related kinase 1/2 kinase and p38, we further demonstrate that ERK1/2 and p38 play a major role in T. denticola-mediated pro- and anti-inflammatory cytokine production.

  12. Enterococcus faecium stimulates human neutrophils via the formyl-peptide receptor 2.

    Directory of Open Access Journals (Sweden)

    Dominik Alexander Bloes

    Full Text Available The human formyl-peptide receptor 2 (FPR2/ALX senses phenol-soluble modulin (PSM peptide toxins produced by pathogenic staphylococcal species and plays a crucial role in directing neutrophil influx during staphylococcal infection. However, it has remained unclear if FPR2 responds also to molecules from other bacterial pathogens. Here we analyzed a variety of gram-positive and gram-negative pathogens and found that apart from staphylococci only certain enterococcal strains have the capacity to stimulate FPR2/ALX. Most of the analyzed Enterococcus faecium but only sporadic Enterococcus faecalis strains released FPR2/ALX-stimulating molecules leading to neutrophil calcium ion fluxes, chemotaxis, and complement receptor upregulation. Among ten test strains vancomycin-resistant E. faecium had a significantly higher capacity to stimulate FPR2/ALX than vancomycin-susceptible strains, suggesting an association of strong FPR2/ALX activation with health-care associated strains. The enterococcal FPR2/ALX agonists were found to be peptides or proteins, which appear, however, to be unrelated to staphylococcal PSMs in sequence and physicochemical properties. Enterococci are among the most frequent invasive bacterial pathogens but the basis of enterococcal virulence and immune activation has remained incompletely understood. Our study indicates that previously unrecognized proteinaceous agonists contribute to Enterococcus-host interaction and underscores the importance of FPR2/ALX in host defense against major endogenous bacterial pathogens.

  13. Preclinical evaluation of SMM-189, a cannabinoid receptor 2-specific inverse agonist.

    Science.gov (United States)

    Presley, Chaela; Abidi, Ammaar; Suryawanshi, Satyendra; Mustafa, Suni; Meibohm, Bernd; Moore, Bob M

    2015-08-01

    Cannabinoid receptor 2 agonists and inverse agonists are emerging as new therapeutic options for a spectrum of autoimmune-related disease. Of particular interest, is the ability of CB2 ligands to regulate microglia function in neurodegenerative diseases and traumatic brain injury. We have previously reported the receptor affinity of 3',5'-dichloro-2,6-dihydroxy-biphenyl-4-yl)-phenyl-methanone (SMM-189) and the characterization of the beneficial effects of SMM-189 in the mouse model of mild traumatic brain injury. Herein, we report the further characterization of SMM-189 as a potent and selective CB2 inverse agonist, which acts as a noncompetitive inhibitor of CP 55,940. The ability of SMM-189 to regulate microglial activation, in terms of chemokine expression and cell morphology, has been determined. Finally, we have determined that SMM-189 possesses acceptable biopharmaceutical properties indicating that the triaryl class of CB2 inverse agonists are viable compounds for continued preclinical development for the treatment of neurodegenerative disorders and traumatic brain injury.

  14. Critical role of somatostatin receptor 2 in the vulnerability of the central noradrenergic system

    DEFF Research Database (Denmark)

    Ádori, Csaba; Glück, Laura; Barde, Swapnali;

    2015-01-01

    Alzheimer’s disease and other age-related neurodegenerative disorders are associated with deterioration of the noradrenergic locus coeruleus (LC), a probable trigger for mood and memory dysfunction. LC noradrenergic neurons exhibit particularly high levels of somatostatin binding sites. This is n......Alzheimer’s disease and other age-related neurodegenerative disorders are associated with deterioration of the noradrenergic locus coeruleus (LC), a probable trigger for mood and memory dysfunction. LC noradrenergic neurons exhibit particularly high levels of somatostatin binding sites...... morphometry and mRNA profiling in a cohort of Alzheimer’s and age-matched control brains in combination with genetic models of somatostatin receptor deficiency to establish causality between defunct somatostatin signalling and noradrenergic neurodegeneration. In Alzheimer’s disease, we found significantly...... reduced somatostatin protein expression in the temporal cortex, with aberrant clustering and bulging of tyrosine hydroxylase-immunoreactive afferents. As such, somatostatin receptor 2 (SSTR2) mRNA was highly expressed in the human LC, with its levels significantly decreasing from Braak stages III...

  15. Constitutively active form of natriuretic peptide receptor 2 ameliorates experimental pulmonary arterial hypertension.

    Science.gov (United States)

    Nawa, Nobutoshi; Ishida, Hidekazu; Katsuragi, Shinichi; Baden, Hiroki; Takahashi, Kunihiko; Higeno, Ryota; Torigoe, Fumiko; Mihara, Seiko; Narita, Jun; Miura, Kohji; Nakamura, Kazufumi; Kogaki, Shigetoyo; Ozono, Keiichi

    2016-01-01

    We recently found a constitutively active mutant of natriuretic peptide receptor 2 (caNPR2; V883M), which synthesizes larger amounts of cyclic guanosine monophosphate (cGMP) intracellularly without any ligand stimulation than existing drugs. The aim of this study was to investigate the therapeutic effects of gene transduction using caNPR2 for pulmonary arterial hypertension (PAH). In vitro gene transduction into human pulmonary arterial smooth muscle cells using Sendai virus (SeV) vectors carrying caNPR2 induced 10,000-fold increases in the synthesis of cGMP without ligand stimulation, and the proliferation of caNPR2-expressing cells was significantly attenuated. The PAH model rats generated by hypoxia and the administration of SU5416 were then treated with SeV vectors through a direct injection into the left pulmonary artery. Right ventricular systolic pressure was significantly decreased 2 weeks after the treatment, while systemic blood pressure remained unchanged. Histological analyses revealed that the medial wall thickness and occlusion rate of pulmonary arterioles were significantly improved in caNPR2-treated lungs. Neither the systemic integration of virus vectors nor side effects were observed. The massive stimulation of cGMP synthesis by gene therapy with caNPR2 was safe and effective in a PAH rat model and, thus, has potential as a novel therapy for patients with severe progressive PAH.

  16. Acanthamoeba protease activity promotes allergic airway inflammation via protease-activated receptor 2.

    Science.gov (United States)

    Park, Mi Kyung; Cho, Min Kyoung; Kang, Shin Ae; Park, Hye-Kyung; Kim, Dong-Hee; Yu, Hak Sun

    2014-01-01

    Acanthamoeba is a free-living amoeba commonly present in the environment and often found in human airway cavities. Acanthamoeba possesses strong proteases that can elicit allergic airway inflammation. To our knowledge, the aeroallergenicity of Acanthamoeba has not been reported. We repeatedly inoculated mice with Acanthamoeba trophozoites or excretory-secretory (ES) proteins intra-nasally and evaluated symptoms and airway immune responses. Acanthamoeba trophozoites or ES proteins elicited immune responses in mice that resembled allergic airway inflammation. ES proteins had strong protease activity and activated the expression of several chemokine genes (CCL11, CCL17, CCL22, TSLP, and IL-25) in mouse lung epithelial cells. The serine protease inhibitor phenyl-methane-sulfonyl fluoride (PMSF) inhibited ES protein activity. ES proteins also stimulated dendritic cells and enhanced the differentiation of naive T cells into IL-4-secreting T cells. After repeated inoculation of the protease-activated receptor 2 knockout mouse with ES proteins, airway inflammation and Th2 immune responses were markedly reduced, but not to basal levels. Furthermore, asthma patients had higher Acanthamoeba-specific IgE titers than healthy controls and we found Acanthamoeba specific antigen from house dust in typical living room. Our findings suggest that Acanthamoeba elicits allergic airway symptoms in mice via a protease allergen. In addition, it is possible that Acanthamoeba may be one of the triggers human airway allergic disease.

  17. Acanthamoeba protease activity promotes allergic airway inflammation via protease-activated receptor 2.

    Directory of Open Access Journals (Sweden)

    Mi Kyung Park

    Full Text Available Acanthamoeba is a free-living amoeba commonly present in the environment and often found in human airway cavities. Acanthamoeba possesses strong proteases that can elicit allergic airway inflammation. To our knowledge, the aeroallergenicity of Acanthamoeba has not been reported. We repeatedly inoculated mice with Acanthamoeba trophozoites or excretory-secretory (ES proteins intra-nasally and evaluated symptoms and airway immune responses. Acanthamoeba trophozoites or ES proteins elicited immune responses in mice that resembled allergic airway inflammation. ES proteins had strong protease activity and activated the expression of several chemokine genes (CCL11, CCL17, CCL22, TSLP, and IL-25 in mouse lung epithelial cells. The serine protease inhibitor phenyl-methane-sulfonyl fluoride (PMSF inhibited ES protein activity. ES proteins also stimulated dendritic cells and enhanced the differentiation of naive T cells into IL-4-secreting T cells. After repeated inoculation of the protease-activated receptor 2 knockout mouse with ES proteins, airway inflammation and Th2 immune responses were markedly reduced, but not to basal levels. Furthermore, asthma patients had higher Acanthamoeba-specific IgE titers than healthy controls and we found Acanthamoeba specific antigen from house dust in typical living room. Our findings suggest that Acanthamoeba elicits allergic airway symptoms in mice via a protease allergen. In addition, it is possible that Acanthamoeba may be one of the triggers human airway allergic disease.

  18. Formyl Peptide Receptor 2 Plays a Deleterious Role During Influenza A Virus Infections.

    Science.gov (United States)

    Tcherniuk, Sergey; Cenac, Nicolas; Comte, Marjorie; Frouard, Julie; Errazuriz-Cerda, Elisabeth; Galabov, Angel; Morange, Pierre-Emmanuel; Vergnolle, Nathalie; Si-Tahar, Mustapha; Alessi, Marie-Christine; Riteau, Béatrice

    2016-07-15

    The pathogenesis of influenza A virus (IAV) infections is a multifactorial process that includes the replication capacity of the virus and a harmful inflammatory response to infection. Formyl peptide receptor 2 (FPR2) emerges as a central receptor in inflammatory processes controlling resolution of acute inflammation. Its role in virus pathogenesis has not been investigated yet. We used pharmacologic approaches to investigate the role of FPR2 during IAV infection in vitro and in vivo. In vitro, FPR2 expressed on A549 cells was activated by IAV, which harbors its ligand, annexin A1, in its envelope. FPR2 activation by IAV promoted viral replication through an extracellular-regulated kinase (ERK)-dependent pathway. In vivo, activating FPR2 by administering the agonist WKYMVm-NH2 decreased survival and increased viral replication and inflammation after IAV infection. This effect was abolished by treating the mice with U0126, a specific ERK pathway inhibitor, showing that, in vivo, the deleterious role of FPR2 also occurs through an ERK-dependent pathway. In contrast, administration of the FPR2 antagonist WRW4 protected mice from lethal IAV infections. These data show that viral replication and IAV pathogenesis depend on FPR2 signaling and suggest that FPR2 may be a promising novel strategy to treat influenza. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

  19. The role of Toll-like receptor 2 in inflammation and fibrosis during progressive renal injury.

    Directory of Open Access Journals (Sweden)

    Jaklien C Leemans

    Full Text Available Tissue fibrosis and chronic inflammation are common causes of progressive organ damage, including progressive renal disease, leading to loss of physiological functions. Recently, it was shown that Toll-like receptor 2 (TLR2 is expressed in the kidney and activated by endogenous danger signals. The expression and function of TLR2 during renal fibrosis and chronic inflammation has however not yet been elucidated. Therefore, we studied TLR2 expression in human and murine progressive renal diseases and explored its role by inducing obstructive nephropathy in TLR2(-/- or TLR2(+/+ mice. We found that TLR2 is markedly upregulated on tubular and tubulointerstitial cells in patients with chronic renal injury. In mice with obstructive nephropathy, renal injury was associated with a marked upregulation and change in distribution of TLR2 and upregulation of murine TLR2 danger ligands Gp96, biglycan, and HMGB1. Notably, TLR2 enhanced inflammation as reflected by a significantly reduced influx of neutrophils and production of chemokines and TGF-beta in kidneys of TLR2(-/- mice compared with TLR2(+/+ animals. Although, the obstructed kidneys of TLR2(-/- mice had less interstitial myofibroblasts in the later phase of obstructive nephropathy, tubular injury and renal matrix accumulation was similar in both mouse strains. Together, these data demonstrate that TLR2 can initiate renal inflammation during progressive renal injury and that the absence of TLR2 does not affect the development of chronic renal injury and fibrosis.

  20. Molecular Mechanisms and Translational Therapies for Human Epidermal Receptor 2 Positive Breast Cancer

    Directory of Open Access Journals (Sweden)

    Quanxia Lv

    2016-12-01

    Full Text Available Breast cancer is the second leading cause of cancer death among women. Human epidermal receptor 2 (HER2 positive breast cancer (HER2+ BC is the most aggressive subtype of breast cancer, with poor prognosis and a high rate of recurrence. About one third of breast cancer is HER2+ BC with significantly high expression level of HER2 protein compared to other subtypes. Therefore, HER2 is an important biomarker and an ideal target for developing therapeutic strategies for the treatment HER2+ BC. In this review, HER2 structure and physiological and pathological roles in HER2+ BC are discussed. Two diagnostic tests, immunohistochemistry (IHC and fluorescent in situ hybridization (FISH, for evaluating HER2 expression levels are briefly introduced. The current mainstay targeted therapies for HER2+ BC include monoclonal antibodies, small molecule tyrosine kinase inhibitors, antibody–drug conjugates (ADC and other emerging anti-HER2 agents. In clinical practice, combination therapies are commonly adopted in order to achieve synergistic drug response. This review will help to better understand the molecular mechanism of HER2+ BC and further facilitate the development of more effective therapeutic strategies against HER2+ BC.

  1. Distribution of cysteinyl leukotriene receptor 2 in human traumatic brain injury and brain tumors

    Institute of Scientific and Technical Information of China (English)

    Hua HU; Er-qing WEI; Gao CHEN; Jian-min ZHANG; Wei-ping ZHANG; Lei ZHANG; Qiu-fu GE; Hong-tian YAO; Wei DING; Zhong CHEN

    2005-01-01

    Aim: To determine the distribution of cysteinyl leukotriene receptor 2 (CysLT2),one of the cysteinyl leukotriene receptors, in human brains with traumatic injury and tumors. Methods: Brain specimens were obtained from patients who underwent brain surgery. CysLT2 in brain tissues was examined using immunohistochemical analysis. Results: CysLT2 was expressed in the smooth muscle cells (not in the endothelial cells) of arteries and veins. CysLT2 was also expressed in the granulocytes in both vessels and in the brain parenchyma. In addition, CysLT2 was detected in neuron- and glial-appearing cells in either the late stages of traumatic injury or in the area surrounding the tumors. Microvessels regenerated 8 d after trauma and CysLT2 expression was recorded in their endothelial cells.Conclusion: CysLT2 is distributed in vascular smooth muscle cells and granulocytes, and brain trauma and tumor can induce its expression in vascular endothelial cells and in a number of other cells.

  2. The role of hepatic transferrin receptor 2 in the regulation of iron homeostasis in the body.

    Directory of Open Access Journals (Sweden)

    Christal A Worthen

    2014-03-01

    Full Text Available Fine tuning of body iron is required to prevent diseases such as iron-overload and anemia. The putative iron-sensor, transferrin receptor 2 (TfR2, is expressed in the liver and mutations in this protein result in the iron-overload disease Type III hereditary hemochromatosis (HH. With the loss of functional TfR2, the liver produces about two-fold less of the peptide hormone hepcidin, which is responsible for negatively regulating iron uptake from the diet. This reduction in hepcidin expression leads to the slow accumulation of iron in the liver, heart, joints, and pancreas and subsequent cirrhosis, heart disease, arthritis, and diabetes. TfR2 can bind iron-loaded transferrin in the bloodstream, and hepatocytes treated with transferrin respond with a two-fold increase in hepcidin expression through stimulation of the BMP-signaling pathway. Loss of functional TfR2 or its binding partner, the original HH protein (HFE, results in a loss of this transferrin-sensitivity. While much is known about the trafficking and regulation of TfR2, the mechanism of its transferrin-sensitivity through the BMP-signaling pathway is still not known.

  3. ApoE receptor 2 regulates synapse and dendritic spine formation.

    Directory of Open Access Journals (Sweden)

    Sonya B Dumanis

    Full Text Available BACKGROUND: Apolipoprotein E receptor 2 (ApoEr2 is a postsynaptic protein involved in long-term potentiation (LTP, learning, and memory through unknown mechanisms. We examined the biological effects of ApoEr2 on synapse and dendritic spine formation-processes critical for learning and memory. METHODOLOGY/PRINCIPAL FINDINGS: In a heterologous co-culture synapse assay, overexpression of ApoEr2 in COS7 cells significantly increased colocalization with synaptophysin in primary hippocampal neurons, suggesting that ApoEr2 promotes interaction with presynaptic structures. In primary neuronal cultures, overexpression of ApoEr2 increased dendritic spine density. Consistent with our in vitro findings, ApoEr2 knockout mice had decreased dendritic spine density in cortical layers II/III at 1 month of age. We also tested whether the interaction between ApoEr2 and its cytoplasmic adaptor proteins, specifically X11α and PSD-95, affected synapse and dendritic spine formation. X11α decreased cell surface levels of ApoEr2 along with synapse and dendritic spine density. In contrast, PSD-95 increased cell surface levels of ApoEr2 as well as synapse and dendritic spine density. CONCLUSIONS/SIGNIFICANCE: These results suggest that ApoEr2 plays important roles in structure and function of CNS synapses and dendritic spines, and that these roles are modulated by cytoplasmic adaptor proteins X11α and PSD-95.

  4. A host deficiency of discoidin domain receptor 2 (DDR2) inhibits both tumour angiogenesis and metastasis.

    Science.gov (United States)

    Zhang, Shuya; Bu, Xin; Zhao, Hu; Yu, Jiangtian; Wang, Yingmei; Li, Di; Zhu, Chuchao; Zhu, Tong; Ren, Tingting; Liu, Xinping; Yao, Libo; Su, Jin

    2014-03-01

    Discoidin domain receptor 2 (DDR2) is a unique receptor tyrosine kinase (RTK) that signals in response to collagen binding and is implicated in tumour malignant phenotypes such as invasion and metastasis. Although it has been reported that DDR2 expression is up-regulated in activated endothelial cells (ECs), functional studies are lacking. Herein, we found that enforced expression of DDR2 promoted proliferation, migration and tube formation of primary human umbilical vein endothelial cells (HUVECs). The results of immunohistochemical analysis showed a strikingly high level of DDR2 in human tumour ECs. Most significantly, we discovered that a host deficiency of DDR2 inhibits subcutaneous angiogenesis induced by either VEGF or tumour cells. In addition, the remaining tumour vessels in DDR2-deficient mice exhibit some normalized properties. These vascular phenotypes are accompanied by the up-regulation of anti-angiogenic genes and down-regulation of pro-angiogenic genes, as well as by alleviated tumour hypoxia. By use of a tail vein metastasis model of melanoma, we uncovered that loss of stromal DDR2 also suppresses tumour metastasis to the lung. Hence, our current data disclose a new mechanism by which DDR2 affects tumour progression, and may strengthen the feasibility of targeting DDR2 as an anticancer strategy.

  5. Type I collagen aging impairs discoidin domain receptor 2-mediated tumor cell growth suppression.

    Science.gov (United States)

    Saby, Charles; Buache, Emilie; Brassart-Pasco, Sylvie; El Btaouri, Hassan; Courageot, Marie-Pierre; Van Gulick, Laurence; Garnotel, Roselyne; Jeannesson, Pierre; Morjani, Hamid

    2016-05-03

    Tumor cells are confronted to a type I collagen rich environment which regulates cell proliferation and invasion. Biological aging has been associated with structural changes of type I collagen. Here, we address the effect of collagen aging on cell proliferation in a three-dimensional context (3D).We provide evidence for an inhibitory effect of adult collagen, but not of the old one, on proliferation of human fibrosarcoma HT-1080 cells. This effect involves both the activation of the tyrosine kinase Discoidin Domain Receptor 2 (DDR2) and the tyrosine phosphatase SHP-2. DDR2 and SHP-2 were less activated in old collagen. DDR2 inhibition decreased SHP-2 phosphorylation in adult collagen and increased cell proliferation to a level similar to that observed in old collagen.In the presence of old collagen, a high level of JAK2 and ERK1/2 phosphorylation was observed while expression of the cell cycle negative regulator p21CIP1 was decreased. Inhibition of DDR2 kinase function also led to an increase in ERK1/2 phosphorylation and a decrease in p21CIP1 expression. Similar signaling profile was observed when DDR2 was inhibited in adult collagen. Altogether, these data suggest that biological collagen aging could increase tumor cell proliferation by reducingthe activation of the key matrix sensor DDR2.

  6. Expression of Discoidin Domain Receptor 2 (DDR2) in the Developing Heart

    Science.gov (United States)

    Morales, Mary O.; Price, Robert L.; Goldsmith, Edie C.

    2005-06-01

    Interactions between cells and the surrounding extracellular matrix are important for a number of developmental events. In the heart, cardiac fibroblasts produce the majority of extracellular matrix proteins, particularly collagen types I and III. Cells originating from the proepicardial organ migrate over the surface of the heart, invade the underlying myocardium and ultimately give rise to smooth muscle cells, fibroblasts, and coronary endothelium. Although integrin expression in the developing heart has been well characterized, the expression of Discoidin Domain Receptor 2 (DDR2) remains to be defined. Using confocal microscopy, the expression of DDR2 was examined at several points during cardiac development. Initially, DDR2 expression was detected on the epicardial surface of the heart and on endothelial and mesenchymal cells within the cardiac cushions. As development progressed, DDR2 expression increased at localized regions in the apex and atrioventricular sulcus, although this expression decreased from epicardial to endocardial surface. Eventually, DDR2 expression spanned the myocardial free wall and was detected within the septum. Not until postnatal development was DDR2 expression detected uniformly throughout the myocardium and this distribution was maintained in the adult heart. In summary, the data presented demonstrate that the distribution of DDR2-positive cells changes within the heart during development.

  7. Tryptanthrin Inhibits Angiogenesis by Targeting the VEGFR2-Mediated ERK1/2 Signalling Pathway

    OpenAIRE

    2013-01-01

    Angiogenesis is a key step for tumour growth and metastasis, and anti-angiogenesis has been proposed as an important strategy for cancer therapy. Tryptanthrin is a weakly basic alkaloid isolated from the dried roots of medicinal indigo plants and has been shown to possess anti-tumour activities on various cancer cell types. This study aims to investigate the in vitro and in vivo anti-angiogenic activities of tryptanthrin and to unravel its underlying molecular action mechanisms. Our results s...

  8. The association of the dopamine transporter gene and the dopamine receptor 2 gene with delirium: a meta-analysis.

    NARCIS (Netherlands)

    Munster, B.C. van; Rooij, S.E.J.A. de; Yazdanpanah, M.; Tienari, P.J.; Pitkala, K.H.; Osse, R.J.; Adamis, D.; Smit, O.; Steen, M.S. van der; Houten, M. van; Rahkonen, T.; Sulkava, R.; Laurila, J.V.; Strandberg, T.E.; Tulen, J.H.M.; Zwang, L.; Macdonald, A.J.D.; Treloar, A.; Sijbrands, E.J.G.; Zwinderman, A.H.; Korevaar, J.C.

    2010-01-01

    Delirium is the most common neuropsychiatric syndrome in elderly ill patients. Previously, associations between delirium and the dopamine transporter gene (solute carrier family 6, member 3 (SLC6A3)) and dopamine receptor 2 gene (DRD2) were found. The aim of this study was to validate whether marker

  9. Extracellular loop 2 of the free Fatty Acid receptor 2 mediates allosterism of a phenylacetamide ago-allosteric modulator

    DEFF Research Database (Denmark)

    Smith, Nicola J; Ward, Richard J; Stoddart, Leigh A;

    2011-01-01

    Allosteric agonists are powerful tools for exploring the pharmacology of closely related G protein-coupled receptors that have nonselective endogenous ligands, such as the short chain fatty acids at free fatty acid receptors 2 and 3 (FFA2/GPR43 and FFA3/GPR41, respectively). We explored the molec...

  10. GENES, IN ADDITION TO TOLL-LIKE RECEPTOR 2, PLAY A ROLE IN ANTIBACTERIAL DEFENSE TO STREPTOCOCCAL PNEUMONIA

    Science.gov (United States)

    Streptococcus infection in human populations continues to be a major cause of morbidity and mortality. To evaluate the effect of genetic background and toll-like receptor 2 (TLR2) on antibacterial defense to streptococcal infection, eight genetically diverse strains of mic...

  11. Toll-like receptor 2 or toll-like receptor 4 deficiency does not modify lupus in MRLlpr mice.

    Directory of Open Access Journals (Sweden)

    Simon J Freeley

    Full Text Available Systemic lupus erythematosus is an autoimmune disease with a high morbidity and nephritis is a common manifestation. Previous studies in murine lupus models have suggest a role for Toll-like receptor 2 and 4. We examined the role of these molecules in MRL lpr mice which is one of the most established and robust murine models. We compared disease parameters in Toll-like receptor 2 or Toll-like receptor 4 deficient mice with their littermate controls. We found no difference in the severity of glomerulonephritis as assessed by histology, serum creatinine and albuminuria when Toll-like receptor 2 or Toll-like receptor 4 deficient MRLlpr mice were compared with Toll-like receptor sufficient controls. We also found similar levels of anti-dsDNA and anti-ssDNA antibodies. These results show that Toll-like receptor 2 and Toll-like receptor 4 do not play a significant role in MRLlpr mice, and therefore they may not be important in human lupus.

  12. Pharmacological and molecular characterization of the positive allosteric modulators of metabotropic glutamate receptor 2.

    Science.gov (United States)

    Lundström, L; Bissantz, C; Beck, J; Dellenbach, M; Woltering, T J; Wichmann, J; Gatti, S

    2017-02-16

    The metabotropic glutamate receptor 2 (mGlu2) plays an important role in the presynaptic control of glutamate release and several mGlu2 positive allosteric modulators (PAMs) have been under assessment for their potential as antipsychotics. The binding mode of mGlu2 PAMs is better characterized in functional terms while few data are available on the relationship between allosteric and orthosteric binding sites. Pharmacological studies characterizing binding and effects of two different chemical series of mGlu2 PAMs are therefore carried out here using the radiolabeled mGlu2 agonist (3)[H]-LY354740 and mGlu2 PAM (3)[H]-2,2,2-TEMPS. A multidimensional approach to the PAM mechanism of action shows that mGlu2 PAMs increase the affinity of (3)[H]-LY354740 for the orthosteric site of mGlu2 as well as the number of (3)[H]-LY354740 binding sites. (3)[H]-2,2,2-TEMPS binding is also enhanced by the presence of LY354740. New residues in the allosteric rat mGlu2 binding pocket are identified to be crucial for the PAMs ligand binding, among these Tyr(3.40) and Asn(5.46). Also of remark, in the described experimental conditions S731A (Ser(5.42)) residue is important only for the mGlu2 PAM LY487379 and not for the compound PAM-1: an example of the structural differences among these mGlu2 PAMs. This study provides a summary of the information generated in the past decade on mGlu2 PAMs adding a detailed molecular investigation of PAM binding mode. Differences among mGlu2 PAM compounds are discussed as well as the mGlu2 regions interacting with mGlu2 PAM and NAM agents and residues driving mGlu2 PAM selectivity.

  13. Estrogen receptor 2b deficiency impairs the antiviral response of zebrafish.

    Science.gov (United States)

    López-Muñoz, Azucena; Liarte, Sergio; Gómez-González, Nuria E; Cabas, Isabel; Meseguer, José; García-Ayala, Alfonsa; Mulero, Victoriano

    2015-11-01

    Although several studies have demonstrated the ability of some endocrine disruptive chemicals (EDCs) to alter the physiology of zebrafish, the immune-reproductive interaction has received little attention in this species. In this study, we used a homozygous line carrying an insertion of 8 amino acids in the ligand-binding domain of the estrogen receptor 2b gene (esr2b) to further understand the role of estrogen signaling on innate immunity. Adult mutant fish showed distorted sexual ratios related with alterations in testicular morphology and supraphysiological testosterone and 17β-estradiol (E2) levels. Immunity-wise, although esr2b mutant fish showed unaltered antibacterial responses, they were unable to mount an effective antiviral response upon viral challenge. RT-qPCR analysis demonstrated that mutant fish were able to induce the genes encoding major antiviral molecules, including Ifnphi1, Ifnphi2, Infphi3, Mxb and Mxc, and the negative feedback regulator of cytokine signaling Socs1. Notably, although esr2b mutant larvae showed a similar resistance to SVCV infection to their wild type siblings, waterborne E2 increased their viral susceptibility. Similarly, the exposure of adult wild type zebrafish to E2 also resulted in increased susceptibility to SVCV infection. Finally, the administration of recombinant Ifnphi1 hardly reversed the higher viral susceptibility of esr2b mutant zebrafish, suggesting that elevated socs1 levels impair Ifn signaling. All together, these results uncover an important role for E2 and Esr signaling in the fine-tuning of sexual hormone balance and the antiviral response of vertebrates.

  14. Structure of CC chemokine receptor 2 with orthosteric and allosteric antagonists

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Yi; Qin, Ling; Ortiz Zacarías, Natalia V.; de Vries, Henk; Han, Gye Won; Gustavsson, Martin; Dabros, Marta; Zhao, Chunxia; Cherney, Robert J.; Carter, Percy; Stamos, Dean; Abagyan, Ruben; Cherezov, Vadim; Stevens, Raymond C.; IJzerman, Adriaan P.; Heitman, Laura H.; Tebben, Andrew; Kufareva, Irina; Handel , Tracy M. (Vertex Pharm); (Leiden-MC); (USC); (BMS); (UCSD)

    2016-12-07

    CC chemokine receptor 2 (CCR2) is one of 19 members of the chemokine receptor subfamily of human class A G-protein-coupled receptors. CCR2 is expressed on monocytes, immature dendritic cells, and T-cell subpopulations, and mediates their migration towards endogenous CC chemokine ligands such as CCL2 (ref. 1). CCR2 and its ligands are implicated in numerous inflammatory and neurodegenerative diseases2 including atherosclerosis, multiple sclerosis, asthma, neuropathic pain, and diabetic nephropathy, as well as cancer3. These disease associations have motivated numerous preclinical studies and clinical trials4 (see http://www.clinicaltrials.gov) in search of therapies that target the CCR2–chemokine axis. To aid drug discovery efforts5, here we solve a structure of CCR2 in a ternary complex with an orthosteric (BMS-681 (ref. 6)) and allosteric (CCR2-RA-[R]7) antagonist. BMS-681 inhibits chemokine binding by occupying the orthosteric pocket of the receptor in a previously unseen binding mode. CCR2-RA-[R] binds in a novel, highly druggable pocket that is the most intracellular allosteric site observed in class A G-protein-coupled receptors so far; this site spatially overlaps the G-protein-binding site in homologous receptors. CCR2-RA-[R] inhibits CCR2 non-competitively by blocking activation-associated conformational changes and formation of the G-protein-binding interface. The conformational signature of the conserved microswitch residues observed in double-antagonist-bound CCR2 resembles the most inactive G-protein-coupled receptor structures solved so far. Like other protein–protein interactions, receptor–chemokine complexes are considered challenging therapeutic targets for small molecules, and the present structure suggests diverse pocket epitopes that can be exploited to overcome obstacles in drug design.

  15. Cathepsin S Cleavage of Protease-Activated Receptor-2 on Endothelial Cells Promotes Microvascular Diabetes Complications.

    Science.gov (United States)

    Kumar Vr, Santhosh; Darisipudi, Murthy N; Steiger, Stefanie; Devarapu, Satish Kumar; Tato, Maia; Kukarni, Onkar P; Mulay, Shrikant R; Thomasova, Dana; Popper, Bastian; Demleitner, Jana; Zuchtriegel, Gabriele; Reichel, Christoph; Cohen, Clemens D; Lindenmeyer, Maja T; Liapis, Helen; Moll, Solange; Reid, Emma; Stitt, Alan W; Schott, Brigitte; Gruner, Sabine; Haap, Wolfgang; Ebeling, Martin; Hartmann, Guido; Anders, Hans-Joachim

    2016-06-01

    Endothelial dysfunction is a central pathomechanism in diabetes-associated complications. We hypothesized a pathogenic role in this dysfunction of cathepsin S (Cat-S), a cysteine protease that degrades elastic fibers and activates the protease-activated receptor-2 (PAR2) on endothelial cells. We found that injection of mice with recombinant Cat-S induced albuminuria and glomerular endothelial cell injury in a PAR2-dependent manner. In vivo microscopy confirmed a role for intrinsic Cat-S/PAR2 in ischemia-induced microvascular permeability. In vitro transcriptome analysis and experiments using siRNA or specific Cat-S and PAR2 antagonists revealed that Cat-S specifically impaired the integrity and barrier function of glomerular endothelial cells selectively through PAR2. In human and mouse type 2 diabetic nephropathy, only CD68(+) intrarenal monocytes expressed Cat-S mRNA, whereas Cat-S protein was present along endothelial cells and inside proximal tubular epithelial cells also. In contrast, the cysteine protease inhibitor cystatin C was expressed only in tubules. Delayed treatment of type 2 diabetic db/db mice with Cat-S or PAR2 inhibitors attenuated albuminuria and glomerulosclerosis (indicators of diabetic nephropathy) and attenuated albumin leakage into the retina and other structural markers of diabetic retinopathy. These data identify Cat-S as a monocyte/macrophage-derived circulating PAR2 agonist and mediator of endothelial dysfunction-related microvascular diabetes complications. Thus, Cat-S or PAR2 inhibition might be a novel strategy to prevent microvascular disease in diabetes and other diseases.

  16. Toll-like receptor 2 ligands regulate monocyte Fcγ receptor expression and function.

    Science.gov (United States)

    Shah, Prexy; Fatehchand, Kavin; Patel, Hemal; Fang, Huiqing; Justiniano, Steven E; Mo, Xiaokui; Jarjoura, David; Tridandapani, Susheela; Butchar, Jonathan P

    2013-04-26

    Fcγ receptor (FcγR) clustering on monocytes/macrophages results in phagocytosis and inflammatory cytokine production, which serve to eliminate antibody-opsonized targets and activate neighboring immune cells. Toll-like receptor 2 (TLR2), which recognizes a range of both bacterial and fungal components, elicits strong proinflammatory responses in these cells when stimulated by ligands, either natural or synthetic. Thus, we explored the possibility that TLR2 agonists could strengthen FcγR activity within the context of antibody therapy. Human peripheral blood monocytes treated with the TLR2 agonist Pam2CSK4 showed significantly enhanced FcγR-mediated cytokine production as well as phagocytic ability. An examination of the molecular mechanism behind this enhancement revealed increased expression of both FcγRIIa and the common γ subunit following Pam2CSK4 treatment. Interestingly however, expression of the inhibitory receptor FcγRIIb was also modestly increased. Further investigation revealed that Pam2CSK4 also dramatically decreased the expression of SHIP, the major mediator of FcγRIIb inhibitory activity. Using a murine Her2/neu solid tumor model of antibody therapy, we found that Pam2CSK4 significantly enhanced the ability of anti-Her2 antibody to reduce the rate of tumor growth. To verify that the FcγR enhancement was not unique to the diacylated Pam2CSK4, we also tested Pam3CSK4, a related triacylated TLR2 agonist. Results showed significant enhancement in FcγR function and expression. Taken together, these findings indicate that TLR2 activation can positively modulate FcγR and suggest that TLR2 agonists should be considered for testing as adjuvants for antitumor antibody therapy.