Photoactivatable Caged Prodrugs of VEGFR-2 Kinase Inhibitors

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Boris Pinchuk; Rebecca Horbert; Alexander Döbber; Lydia Kuhl; Christian Peifer

2016-01-01

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 prodrug...

Novel VEGFR-2 kinase inhibitor identified by the back-to-front approach

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Sanphanya, Kingkan; Phowichit, Suwadee; Wattanapitayakul, Suvara K.; Fokin, Valery V.; Vajragupta, Opa

2013-01-01

Novel lead was developed as VEGFR-2 inhibitor by the back-to-front approach. Docking experiment guided that the 3-chloromethylphenylurea motif occupied the back pocket of the VEGFR-2 kinase. The attempt to enhance the binding affinity of 1 was made by expanding structure to access the front pocket using triazole as linker. A library of 1,4-(disubsituted)-1H-1,2,3-triazoles were screened in silico and one lead compound (VH02) was identified with enzymatic IC50 against VEGFR-2 of 0.56 μM. VH02 showed antiangiogenic effect by inhibiting the tube formation of HUVEC cells (EA.hy926) at 0.3 μM which was 13 times lower than its cytotoxic dose. The enzymatic and cellular activities suggested the potential of VH02 as a lead for further optimization. PMID:23562241

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

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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.

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

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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

2016-05-15

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. © 2016. Published by The Company of Biologists Ltd.

VEGF induces signalling and angiogenesis by directing VEGFR2 internalisation through macropinocytosis.

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Basagiannis, Dimitris; Zografou, Sofia; Murphy, Carol; Fotsis, Theodore; Morbidelli, Lucia; Ziche, Marina; Bleck, Christopher; Mercer, Jason; Christoforidis, Savvas

2016-11-01

Endocytosis plays a crucial role in receptor signalling. VEGFR2 (also known as KDR) and its ligand VEGFA are fundamental in neovascularisation. However, our understanding of the role of endocytosis in VEGFR2 signalling remains limited. Despite the existence of diverse internalisation routes, the only known endocytic pathway for VEGFR2 is the clathrin-mediated pathway. Here, we show that this pathway is the predominant internalisation route for VEGFR2 only in the absence of ligand. Intriguingly, VEGFA induces a new internalisation itinerary for VEGFR2, the pathway of macropinocytosis, which becomes the prevalent endocytic route for the receptor in the presence of ligand, whereas the contribution of the clathrin-mediated route becomes minor. Macropinocytic internalisation of VEGFR2, which mechanistically is mediated through the small GTPase CDC42, takes place through macropinosomes generated at ruffling areas of the membrane. Interestingly, macropinocytosis plays a crucial role in VEGFA-induced signalling, endothelial cell functions in vitro and angiogenesis in vivo, whereas clathrin-mediated endocytosis is not essential for VEGFA signalling. These findings expand our knowledge on the endocytic pathways of VEGFR2 and suggest that VEGFA-driven internalisation of VEGFR2 through macropinocytosis is essential for endothelial cell signalling and angiogenesis. © 2016. Published by The Company of Biologists Ltd.

VEGFR-1 Overexpression Identifies a Small Subgroup of Aggressive Prostate Cancers in Patients Treated by Prostatectomy

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Maria Christina Tsourlakis

2015-04-01

Full Text Available The VEGFR-1 is suggested to promote tumor progression. In the current study we analyzed prevalence and prognostic impact of the VEGFR-1 by immunohistochemistry on a tissue microarray containing more than 3000 prostate cancer specimens. Results were compared to tumor phenotype, ETS-related gene (ERG status, and biochemical recurrence. Membranous VEGFR-1 expression was detectable in 32.6% of 2669 interpretable cancers and considered strong in 1.7%, moderate in 6.7% and weak in 24.2% of cases. Strong VEGFR-1 expression was associated with TMPRSS2:ERG fusion status as determined by fluorescence in situ hybridization (FISH and immunohistochemistry (p < 0.0001 each. Elevated VEGFR-1 expression was linked to high Gleason grade and advanced pT stage in TMPRSS2:ERG negative cancers (p = 0.0008 and p = 0.001, while these associations were absent in TMPRSS2:ERG positive cancers. VEGFR-1 expression was also linked to phosphatase and tensin homolog (PTEN deletions. A comparison with prostate specific antigen (PSA recurrence revealed that the 1.7% of prostate cancers with the highest VEGFR-1 levels had a strikingly unfavorable prognosis. This could be seen in all cancers, in the subsets of TMPRSS2:ERG positive or negative, PTEN deleted or undeleted carcinomas (p < 0.0001 each. High level VEGFR-1 expression is infrequent in prostate cancer, but identifies a subgroup of aggressive cancers, which may be candidates for anti-VEGFR-1 targeted therapy.

Ubiquitination of basal VEGFR2 regulates signal transduction and endothelial function

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Gina A. Smith

2017-10-01

Full Text Available Cell surface receptors can undergo recycling or proteolysis but the cellular decision-making events that sort between these pathways remain poorly defined. Vascular endothelial growth factor A (VEGF-A and vascular endothelial growth factor receptor 2 (VEGFR2 regulate signal transduction and angiogenesis, but how signaling and proteolysis is regulated is not well understood. Here, we provide evidence that a pathway requiring the E1 ubiquitin-activating enzyme UBA1 controls basal VEGFR2 levels, hence metering plasma membrane receptor availability for the VEGF-A-regulated endothelial cell response. VEGFR2 undergoes VEGF-A-independent constitutive degradation via a UBA1-dependent ubiquitin-linked pathway. Depletion of UBA1 increased VEGFR2 recycling from endosome-to-plasma membrane and decreased proteolysis. Increased membrane receptor availability after UBA1 depletion elevated VEGF-A-stimulated activation of key signaling enzymes such as PLCγ1 and ERK1/2. Although UBA1 depletion caused an overall decrease in endothelial cell proliferation, surviving cells showed greater VEGF-A-stimulated responses such as cell migration and tubulogenesis. Our study now suggests that a ubiquitin-linked pathway regulates the balance between receptor recycling and degradation which in turn impacts on the intensity and duration of VEGF-A-stimulated signal transduction and the endothelial response.

Immunohistochemical expression of p53, BCL-2, BAX and VEGFR1 proteins in nephroblastomas A expressão imuno-histoquímica das proteínas p53, BCL-2, BAX e VEGFR1 em nefroblastomas

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Ana Paula Percicote

2013-02-01

Full Text Available INTRODUCTION: Nephroblastoma or Wilms' tumor is the most frequent renal cancer in children. Although its prognosis is favorable for most patients, it may relapse or have a fatal outcome. The characterization of risk groups by applying immunohistochemical biomarkers aims to adapt the treatment to its corresponding group as well as to reduce relapses and fatal outcome. p53, B-cell lymphoma 2 (BCL-2, BCL-2 associated protein X (BAX and vascular endothelial growth factor receptor 1 (VEGFR1 are among the most widely studied biomarkers, which are related to the apoptotic pathway, DNA repair and neovascularization. OBJECTIVE: The objective of this study is to assess the immunohistochemical expression of p53, BCL-2, BAX and VEGFR1 in samples of human nephroblastoma and to correlate them with clinicopathological prognostic factors. MATERIAL AND METHODS: Twenty-nine surgical specimens of nephroblastoma diagnosed from 1994 to 2007 were selected from the Anatomopathological Service of two hospitals in Curitiba. The immunohistochemical analysis of tissue microarrays was performed through immunoperoxidase staining and the yielded results were compared with clinicopathological prognostic factors. RESULTS: The major immunohistochemical expression of VEGFR1 in blastema and epithelium presented positive association with the risk group. Hence this may be related to higher vascular neoplastic invasion apparently caused by the endothelial growth factor, which maximizes the chances of metastasis and ultimately changes tumor staging, risk group and clinical evolution. CONCLUSIONS: The immunohistochemical expression of VEGFR1 substantiated a directly proportional association with the nephroblastoma risk group.INTRODUÇÃO: O nefroblastoma, ou tumor de Wilms, é a neoplasia renal mais frequente na infância. Embora o prognóstico seja favorável para a maioria dos pacientes, muitos evoluem para recidiva ou óbito. A caracterização de grupos de risco por meio de

Ofloxacin induces apoptosis via β1 integrin-EGFR-Rac1-Nox2 pathway in microencapsulated chondrocytes

International Nuclear Information System (INIS)

Sheng, Zhi-Guo; Huang, Wei; Liu, Yu-Xiang; Yuan, Ye; Zhu, Ben-Zhan

2013-01-01

Quinolones (QNs)-induced arthropathy is an important toxic side-effect in immature animals leading to the restriction of their therapeutic use in pediatrics. Ofloxacin, a typical QN, was found to induce the chondrocytes apoptosis in the early phase (12–48 h) of arthropathy in our previous study. However, the exact mechanism(s) is unclear. Microencapsulated juvenile rabbit joint chondrocytes, a three-dimensional culture system, is utilized to perform the present study. Ofloxacin, at a therapeutically relevant concentration (10 μg/ml), disturbs the interaction between β1 integrin and activated intracellular signaling proteins at 12 h, which is inhibited when supplementing Mg 2+ . Intracellular reactive oxygen species (ROS) significantly increases in a time-dependent manner after exposure to ofloxacin for 12–48 h. Furthermore, ofloxacin markedly enhances the level of activated Rac1 and epidermal growth factor receptor (EGFR) phosphorylation, and its inhibition in turn reduces the ROS production, apoptosis and Rac1 activation. Silencing Nox2, Rac1 or supplementing Mg 2+ inhibits ROS accumulation, apoptosis occurrence and EGFR phosphorylation induced by ofloxacin. However, depletion of Nox2, Rac1 and inhibition of EGFR do not affect ofloxacin-mediated loss of interaction between β1 integrin and activated intracellular signaling proteins. In addition, ofloxacin also induces Vav2 phosphorylation, which is markedly suppressed after inactivating EGFR or supplementing Mg 2+ . These results suggest that ofloxacin causes Nox2-mediated intracellular ROS production by disrupting the β1 integrin function and then activating the EGFR-Vav2-Rac1 pathway, finally resulting in apoptosis within 12–48 h exposure. The present study provides a novel insight regarding the potential role of Nox-driven ROS in QNs-induced arthropathy. - Highlights: ► Ofloxacin induces Nox2-driven ROS in encapsulated chondrocyte at 12–48 h. ► Ofloxacin stimulates ROS production via the β1

Ofloxacin induces apoptosis via β1 integrin-EGFR-Rac1-Nox2 pathway in microencapsulated chondrocytes

Energy Technology Data Exchange (ETDEWEB)

Sheng, Zhi-Guo [State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Science, Chinese Academy of Sciences, 18 Shuangqing Road, Beijing 100085 (China); Huang, Wei [Department of Chemical Biology, School of Pharmaceutical Sciences, Peking University Health Science Center, Beijing 1000191 (China); Liu, Yu-Xiang [State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Science, Chinese Academy of Sciences, 18 Shuangqing Road, Beijing 100085 (China); Yuan, Ye [Beijing Institute of Pharmacology and Toxicology, 27 Taiping Road, Beijing 100850 (China); Zhu, Ben-Zhan, E-mail: bzhu@rcees.ac.cn [State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Science, Chinese Academy of Sciences, 18 Shuangqing Road, Beijing 100085 (China); Linus Pauling Institute, Oregon State University, Corvallis, OR 97331 (United States)

2013-02-15

Quinolones (QNs)-induced arthropathy is an important toxic side-effect in immature animals leading to the restriction of their therapeutic use in pediatrics. Ofloxacin, a typical QN, was found to induce the chondrocytes apoptosis in the early phase (12–48 h) of arthropathy in our previous study. However, the exact mechanism(s) is unclear. Microencapsulated juvenile rabbit joint chondrocytes, a three-dimensional culture system, is utilized to perform the present study. Ofloxacin, at a therapeutically relevant concentration (10 μg/ml), disturbs the interaction between β1 integrin and activated intracellular signaling proteins at 12 h, which is inhibited when supplementing Mg{sup 2+}. Intracellular reactive oxygen species (ROS) significantly increases in a time-dependent manner after exposure to ofloxacin for 12–48 h. Furthermore, ofloxacin markedly enhances the level of activated Rac1 and epidermal growth factor receptor (EGFR) phosphorylation, and its inhibition in turn reduces the ROS production, apoptosis and Rac1 activation. Silencing Nox2, Rac1 or supplementing Mg{sup 2+} inhibits ROS accumulation, apoptosis occurrence and EGFR phosphorylation induced by ofloxacin. However, depletion of Nox2, Rac1 and inhibition of EGFR do not affect ofloxacin-mediated loss of interaction between β1 integrin and activated intracellular signaling proteins. In addition, ofloxacin also induces Vav2 phosphorylation, which is markedly suppressed after inactivating EGFR or supplementing Mg{sup 2+}. These results suggest that ofloxacin causes Nox2-mediated intracellular ROS production by disrupting the β1 integrin function and then activating the EGFR-Vav2-Rac1 pathway, finally resulting in apoptosis within 12–48 h exposure. The present study provides a novel insight regarding the potential role of Nox-driven ROS in QNs-induced arthropathy. - Highlights: ► Ofloxacin induces Nox2-driven ROS in encapsulated chondrocyte at 12–48 h. ► Ofloxacin stimulates ROS production via

Advanced glycation end product Nε-carboxymethyllysine induces endothelial cell injury: the involvement of SHP-1-regulated VEGFR-2 dephosphorylation.

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Liu, Shing Hwa; Sheu, Wayne Huey Herng; Lee, Maw Rong; Lee, Wen Jane; Yi, Yu Chiao; Yang, Tzung Jie; Jen, Jen Fon; Pan, Hung Chuan; Shen, Chin Chang; Chen, Wen Bao; Tien, Hsing Ru; Sheu, Meei Ling

2013-06-01

N(ε)-carboxymethyllysine (CML), a major advanced glycation end product, plays a crucial role in diabetes-induced vascular injury. The roles of protein tyrosine phosphatases and vascular endothelial growth factor (VEGF) receptors in CML-related endothelial cell injury are still unclear. Human umbilical vein endothelial cells (HUVECs) are a commonly used human EC type. Here, we tested the hypothesis that NADPH oxidase/reactive oxygen species (ROS)-mediated SH2 domain-containing tyrosine phosphatase-1 (SHP-1) activation by CML inhibits the VEGF receptor-2 (VEGFR-2, KDR/Flk-1) activation, resulting in HUVEC injury. CML significantly inhibited cell proliferation and induced apoptosis and reduced VEGFR-2 activation in parallel with the increased SHP-1 protein expression and activity in HUVECs. Adding recombinant VEGF increased forward biological effects, which were attenuated by CML. The effects of CML on HUVECs were abolished by SHP-1 siRNA transfection. Exposure of HUVECs to CML also remarkably escalated the integration of SHP-1 with VEGFR-2. Consistently, SHP-1 siRNA transfection and pharmacological inhibitors could block this interaction and elevating [(3)H]thymidine incorporation. CML also markedly activated the NADPH oxidase and ROS production. The CML-increased SHP-1 activity in HUVECs was effectively attenuated by antioxidants. Moreover, the immunohistochemical staining of SHP-1 and CML was increased, but phospho-VEGFR-2 staining was decreased in the aortic endothelium of streptozotocin-induced and high-fat diet-induced diabetic mice. We conclude that a pathway of tyrosine phosphatase SHP-1-regulated VEGFR-2 dephosphorylation through NADPH oxidase-derived ROS is involved in the CML-triggered endothelial cell dysfunction/injury. These findings suggest new insights into the development of therapeutic approaches to reduce diabetic vascular complications. Copyright © 2013 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

The enzymatic activity of the VEGFR2 receptor for the biosynthesis of dinucleoside polyphosphates.

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Jankowski, Vera; Schulz, Anna; Kretschmer, Axel; Mischak, Harald; Boehringer, Falko; van der Giet, Markus; Janke, Doreen; Schuchardt, Mirjam; Herwig, Ralf; Zidek, Walter; Jankowski, Joachim

2013-09-01

The group of dinucleoside polyphosphates encompasses a large number of molecules consisting of two nucleosides which are connected by a phosphate chain of variable length. While the receptors activated by dinucleoside polyphosphates as well as their degradation have been studied in detail, its biosynthesis has not been elucidated so far. Since endothelial cells released the dinucleoside polyphosphate uridine adenosine tetraphosphate (Up4A), we tested cytosolic proteins of human endothelial cells obtained from dermal vessels elicited for enzymatic activity. When incubated with ADP and UDP, these cells showed increasing concentrations of Up4A. The underlying enzyme was isolated by chromatography and the mass spectrometric analysis revealed that the enzymatic activity was caused by the vascular endothelial growth factor receptor 2 (VEGFR2). Since VEGFR2 but neither VEGFR1 nor VEGFR3 were capable to synthesise dinucleoside polyphosphates, Tyr-1175 of VEGFR2 is most likely essential for the enzymatic activity of interest. Further, VEGFR2-containing cells like HepG2, THP-1 and RAW264.7 were capable of synthesising dinucleoside polyphosphates. VEGFR2-transfected HEK 293T/17 but not native HEK 293T/17 cells synthesised dinucleoside polyphosphates in vivo too. The simultaneous biosynthesis of dinucleoside polyphosphates could amplify the response to VEGF, since dinucleoside polyphosphates induce cellular growth via P2Y purinergic receptors. Thus the biosynthesis of dinucleoside polyphosphates by VEGFR2 may enhance the proliferative response to VEGF. Given that VEGFR2 is primarily expressed in endothelial cells, the biosynthesis of dinucleoside polyphosphates is mainly located in the vascular system. Since the vasculature is also the main site of action of dinucleoside polyphosphates, activating vascular purinoceptors, blood vessels appear as an autocrine system with respect to dinucleoside polyphosphates. We conclude that VEGFR2 receptor is capable of synthesising

Ubiquitination of basal VEGFR2 regulates signal transduction and endothelial function.

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Smith, Gina A; Fearnley, Gareth W; Abdul-Zani, Izma; Wheatcroft, Stephen B; Tomlinson, Darren C; Harrison, Michael A; Ponnambalam, Sreenivasan

2017-10-15

Cell surface receptors can undergo recycling or proteolysis but the cellular decision-making events that sort between these pathways remain poorly defined. Vascular endothelial growth factor A (VEGF-A) and vascular endothelial growth factor receptor 2 (VEGFR2) regulate signal transduction and angiogenesis, but how signaling and proteolysis is regulated is not well understood. Here, we provide evidence that a pathway requiring the E1 ubiquitin-activating enzyme UBA1 controls basal VEGFR2 levels, hence metering plasma membrane receptor availability for the VEGF-A-regulated endothelial cell response. VEGFR2 undergoes VEGF-A-independent constitutive degradation via a UBA1-dependent ubiquitin-linked pathway. Depletion of UBA1 increased VEGFR2 recycling from endosome-to-plasma membrane and decreased proteolysis. Increased membrane receptor availability after UBA1 depletion elevated VEGF-A-stimulated activation of key signaling enzymes such as PLCγ1 and ERK1/2. Although UBA1 depletion caused an overall decrease in endothelial cell proliferation, surviving cells showed greater VEGF-A-stimulated responses such as cell migration and tubulogenesis. Our study now suggests that a ubiquitin-linked pathway regulates the balance between receptor recycling and degradation which in turn impacts on the intensity and duration of VEGF-A-stimulated signal transduction and the endothelial response. © 2017. Published by The Company of Biologists Ltd.

Autocrine stimulation of VEGFR-2 activates human leukemic cell growth and migration

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Dias, Sergio; Hattori, Koichi; Zhu, Zhenping; Heissig, Beate; Choy, Margaret; Lane, William; Wu, Yan; Chadburn, Amy; Hyjek, Elizabeth; Gill, Muhammad; Hicklin, Daniel J.; Witte, Larry; Moore, M.A.S.; Rafii, Shahin

2000-01-01

Emerging data suggest that VEGF receptors are expressed by endothelial cells as well as hematopoietic stem cells. Therefore, we hypothesized that functional VEGF receptors may also be expressed in malignant counterparts of hematopoietic stem cells such as leukemias. We demonstrate that certain leukemias not only produce VEGF but also express functional VEGFR-2 in vivo and in vitro, resulting in the generation of an autocrine loop that may support leukemic cell survival and proliferation. Approximately 50% of freshly isolated leukemias expressed mRNA and protein for VEGFR-2. VEGF165 induced phosphorylation of VEGFR-2 and increased proliferation of leukemic cells, demonstrating these receptors were functional. VEGF165 also induced the expression of MMP-9 by leukemic cells and promoted their migration through reconstituted basement membrane. The neutralizing mAb IMC-1C11, specific to human VEGFR-2, inhibited leukemic cell survival in vitro and blocked VEGF165-mediated proliferation of leukemic cells and VEGF-induced leukemic cell migration. Xenotransplantation of primary leukemias and leukemic cell lines into immunocompromised nonobese diabetic mice resulted in significant elevation of human, but not murine, VEGF in plasma and death of inoculated mice within 3 weeks. Injection of IMC-1C11 inhibited proliferation of xenotransplanted human leukemias and significantly increased the survival of inoculated mice. Interruption of signaling by VEGFRs, particularly VEGFR-2, may provide a novel strategy for inhibiting leukemic cell proliferation. PMID:10953026

Vasculature analysis of patient derived tumor xenografts using species-specific PCR assays: evidence of tumor endothelial cells and atypical VEGFA-VEGFR1/2 signalings

International Nuclear Information System (INIS)

Bieche, Ivan; Marangoni, Elisabetta; Roman-Roman, Sergio; Decaudin, Didier; Dangles-Marie, Virginie; Vacher, Sophie; Vallerand, David; Richon, Sophie; Hatem, Rana; De Plater, Ludmilla; Dahmani, Ahmed; Némati, Fariba; Angevin, Eric

2014-01-01

Tumor endothelial transdifferentiation and VEGFR1/2 expression by cancer cells have been reported in glioblastoma but remain poorly documented for many other cancer types. To characterize vasculature of patient-derived tumor xenografts (PDXs), largely used in preclinical anti-angiogenic assays, we designed here species-specific real-time quantitative RT-PCR assays. Human and mouse PECAM1/CD31, ENG/CD105, FLT1/VEGFR1, KDR/VEGFR2 and VEGFA transcripts were analyzed in a large series of 150 PDXs established from 8 different tumor types (53 colorectal, 14 ovarian, 39 breast and 15 renal cell cancers, 6 small cell and 5 non small cell lung carcinomas, 13 cutaneous melanomas and 5 glioblastomas) and in two bevacizumab-treated non small cell lung carcinomas xenografts. As expected, mouse cell proportion in PDXs -evaluated by quantifying expression of the housekeeping gene TBP- correlated with all mouse endothelial markers and human VEGFA RNA levels. More interestingly, we observed human PECAM1/CD31 and ENG/CD105 expression in all tumor types, with higher rate in glioblastoma and renal cancer xenografts. Human VEGFR expression profile varied widely depending on tumor types with particularly high levels of human FLT1/VEGFR1 transcripts in colon cancers and non small cell lung carcinomas, and upper levels of human KDR/VEGFR2 transcripts in non small cell lung carcinomas. Bevacizumab treatment induced significant low expression of mouse Pecam1/Cd31, Eng/Cd105, Flt1/Vegfr1 and Kdr/Vefr2 while the human PECAM1/CD31 and VEGFA were upregulated. Taken together, our results strongly suggest existence of human tumor endothelial cells in all tumor types tested and of both stromal and tumoral autocrine VEGFA-VEGFR1/2 signalings. These findings should be considered when evaluating molecular mechanisms of preclinical response and resistance to tumor anti-angiogenic strategies

Prognostic value of circulating VEGFR2+ bone marrow-derived progenitor cells in patients with advanced cancer.

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Massard, Christophe; Borget, Isabelle; Le Deley, Marie Cécile; Taylor, Melissa; Gomez-Roca, Carlos; Soria, Jean Charles; Farace, Françoise

2012-06-01

We hypothesised that host-related markers, possibly reflecting tumour aggressiveness, such as circulating endothelial cells (CEC) and circulating VEGFR2(+) bone marrow-derived (BMD) progenitor cells, could have prognostic value in patients with advanced cancer enrolled in early anticancer drug development trials. Baseline CECs (CD45(-)CD31(+)CD146(+)7AAD(-) cells) and circulating VEGFR2(+)-BMD progenitor cells (defined as CD45(dim)CD34(+)VEGFR2(+)7AAD(-) cells) were measured by flow-cytometry in 71 and 58 patients included in phase 1 trials testing novel anti-vascular or anti-angiogenic agents. Correlations between levels of CECs, circulating VEGFR2(+)-BMD progenitor cells, clinical and biological prognostic factors (i.e. the Royal Marsden Hospital (RMH) score), and overall survival (OS) were studied. The median value of CECs was 12 CEC/ml (range 0-154/ml). The median level of VEGFR2(+)-BMD progenitor cells was 1.3% (range 0-32.5%) of circulating BMD-CD34(+) progenitors. While OS was not correlated with CEC levels, it was significantly worse in patients with high VEGFR2(+)-BMD progenitor levels (>1%) (median OS 9.0 versus 17.0 months), and with a RMH prognostic score >0 (median OS 9.0 versus 24.2 months). The prognostic value of VEGFR2(+)-BMD progenitor levels remained significant (hazard ratio (HR) = 2.3, 95% confidence interval (CI), 1.1-4.6, p = 0.02) after multivariate analysis. A composite VEGFR2(+)-BMD progenitor level/RHM score ≥ 2 was significantly associated with an increased risk of death compared to scores of 0 or 1 (median OS 9.0 versus 18.4 months, HR = 2.6 (95%CI, 1.2-5.8, p = 0.02)). High circulating VEGFR2(+)-BMD progenitor levels are associated with poor prognostics and when combined to classical clinical and biological parameters could provide a new tool for patient selection in early anticancer drug trials. Copyright © 2012 Elsevier Ltd. All rights reserved.

VEGFR2 Trafficking, Signaling and Proteolysis is Regulated by the Ubiquitin Isopeptidase USP8.

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Smith, Gina A; Fearnley, Gareth W; Abdul-Zani, Izma; Wheatcroft, Stephen B; Tomlinson, Darren C; Harrison, Michael A; Ponnambalam, Sreenivasan

2016-01-01

Vascular endothelial growth factor A (VEGF-A) regulates many aspects of vascular function. VEGF-A binding to vascular endothelial growth factor receptor 2 (VEGFR2) stimulates endothelial signal transduction and regulates multiple cellular responses. Activated VEGFR2 undergoes ubiquitination but the enzymes that regulate this post-translational modification are unclear. In this study, the de-ubiquitinating enzyme, USP8, is shown to regulate VEGFR2 trafficking, de-ubiquitination, proteolysis and signal transduction. USP8-depleted endothelial cells displayed altered VEGFR2 ubiquitination and production of a unique VEGFR2 extracellular domain proteolytic fragment caused by VEGFR2 accumulation in the endosome-lysosome system. In addition, perturbed VEGFR2 trafficking impaired VEGF-A-stimulated signal transduction in USP8-depleted cells. Thus, regulation of VEGFR2 ubiquitination and de-ubiquitination has important consequences for the endothelial cell response and vascular physiology. © 2015 The Authors. Traffic published by John Wiley & Sons Ltd.

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.

Periodic mechanical stress activates EGFR-dependent Rac1 mitogenic signals in rat nucleus pulpous cells via ERK1/2

Energy Technology Data Exchange (ETDEWEB)

Gao, Gongming [Department of Orthopedics, The Affiliated Changzhou No. 2 Hospital of Nanjing Medical University, Changzhou 213003 (China); Shen, Nan [Department of Clinical Pharmacy, The Affiliated Jiangyin Hospital of Southeast University Medical School, Jiangyin 214400 (China); Jiang, Xuefeng; Sun, Huiqing [Department of Orthopedics, The Affiliated Jiangyin Hospital of Southeast University Medical School, Jiangyin 214400 (China); Xu, Nanwei; Zhou, Dong [Department of Orthopedics, The Affiliated Changzhou No. 2 Hospital of Nanjing Medical University, Changzhou 213003 (China); Nong, Luming, E-mail: lumingnong@hotmail.com [Department of Orthopedics, The Affiliated Changzhou No. 2 Hospital of Nanjing Medical University, Changzhou 213003 (China); Ren, Kewei, E-mail: keweiren@hotmail.com [Department of Orthopedics, The Affiliated Jiangyin Hospital of Southeast University Medical School, Jiangyin 214400 (China)

2016-01-15

The mitogenic effects of periodic mechanical stress on nucleus pulpous cells have been studied extensively but the mechanisms whereby nucleus pulpous cells sense and respond to mechanical stimulation remain a matter of debate. We explored this question by performing cell culture experiments in our self-developed periodic stress field and perfusion culture system. Under periodic mechanical stress, rat nucleus pulpous cell proliferation was significantly increased (p < 0.05 for each) and was associated with increases in the phosphorylation and activation of EGFR, Rac1, and ERK1/2 (p < 0.05 for each). Pretreatment with the ERK1/2 selective inhibitor PD98059 reduced periodic mechanical stress-induced nucleus pulpous cell proliferation (p < 0.05 for each), while the activation levels of EGFR and Rac1 were not inhibited. Proliferation and phosphorylation of ERK1/2 were inhibited after pretreatment with the Rac1 inhibitor NSC23766 in nucleus pulpous cells in response to periodic mechanical stress (p < 0.05 for each), while the phosphorylation site of EGFR was not affected. Inhibition of EGFR activity with AG1478 abrogated nucleus pulpous cell proliferation (p < 0.05 for each) and attenuated Rac1 and ERK1/2 activation in nucleus pulpous cells subjected to periodic mechanical stress (p < 0.05 for each). These findings suggest that periodic mechanical stress promotes nucleus pulpous cell proliferation in part through the EGFR-Rac1-ERK1/2 signaling pathway, which links these three important signaling molecules into a mitogenic cascade. - Highlights: • The mechanism involved in nucleus pulpous cells to respond to mechanical stimuli. • Periodic mechanical stress can stimulate the phosphorylation of EGFR. • EGFR activates Rac1 and leads to rat nucleus pulpous cell proliferation. • EGFR and Rac1 activate ERK1/2 mitogenic signals in nucleus pulpous cells. • EGFR-Rac1-ERK1/2 is constitutes at least one critical signal transduction pathway.

Periodic mechanical stress activates EGFR-dependent Rac1 mitogenic signals in rat nucleus pulpous cells via ERK1/2

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Gao, Gongming; Shen, Nan; Jiang, Xuefeng; Sun, Huiqing; Xu, Nanwei; Zhou, Dong; Nong, Luming; Ren, Kewei

2016-01-01

The mitogenic effects of periodic mechanical stress on nucleus pulpous cells have been studied extensively but the mechanisms whereby nucleus pulpous cells sense and respond to mechanical stimulation remain a matter of debate. We explored this question by performing cell culture experiments in our self-developed periodic stress field and perfusion culture system. Under periodic mechanical stress, rat nucleus pulpous cell proliferation was significantly increased (p < 0.05 for each) and was associated with increases in the phosphorylation and activation of EGFR, Rac1, and ERK1/2 (p < 0.05 for each). Pretreatment with the ERK1/2 selective inhibitor PD98059 reduced periodic mechanical stress-induced nucleus pulpous cell proliferation (p < 0.05 for each), while the activation levels of EGFR and Rac1 were not inhibited. Proliferation and phosphorylation of ERK1/2 were inhibited after pretreatment with the Rac1 inhibitor NSC23766 in nucleus pulpous cells in response to periodic mechanical stress (p < 0.05 for each), while the phosphorylation site of EGFR was not affected. Inhibition of EGFR activity with AG1478 abrogated nucleus pulpous cell proliferation (p < 0.05 for each) and attenuated Rac1 and ERK1/2 activation in nucleus pulpous cells subjected to periodic mechanical stress (p < 0.05 for each). These findings suggest that periodic mechanical stress promotes nucleus pulpous cell proliferation in part through the EGFR-Rac1-ERK1/2 signaling pathway, which links these three important signaling molecules into a mitogenic cascade. - Highlights: • The mechanism involved in nucleus pulpous cells to respond to mechanical stimuli. • Periodic mechanical stress can stimulate the phosphorylation of EGFR. • EGFR activates Rac1 and leads to rat nucleus pulpous cell proliferation. • EGFR and Rac1 activate ERK1/2 mitogenic signals in nucleus pulpous cells. • EGFR-Rac1-ERK1/2 is constitutes at least one critical signal transduction pathway.

Centchroman regulates breast cancer angiogenesis via inhibition of HIF-1α/VEGFR2 signalling axis.

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Dewangan, Jayant; Kaushik, Shweta; Rath, Srikanta Kumar; Balapure, Anil K

2018-01-15

Angiogenesis is a recognized hallmark of cancer which promotes cancer cell progression and metastasis. Inhibition of angiogenesis to attenuate cancer growth is becoming desirable strategy for breast cancer management. The present study is aimed to investigate the antiangiogenic efficacy of a novel selective estrogen receptor modulator Centchroman (CC) on human breast cancer cells. Effect of CC on cell viability was evaluated using Sulforhodamine B assay. Endothelial cell proliferation, wound healing, Boyden chamber cell invasion, tube formation and chorioallantoic membrane (CAM) assays were performed to assess the effect of CC on migration, invasion and angiogenesis. Apoptosis, reactive oxygen species generation, caspase-3/7 and intracellular calcium ion level were measured through flow cytometry. Expression levels of HIF-1α, VEGF, VEGFR2, AKT and ERK were assessed by western blot analysis. CC selectively induces apoptosis in human breast cancer cells without affecting non-tumorigenic breast epithelial cells MCF-10A. Moreover, it inhibits migratory, invasive and mammosphere forming potential of breast cancer. Furthermore, CC also inhibited VEGF-induced migration, invasion and tube formation of HUVECs in vitro. CC effectively inhibited neovasculature formation in chicken CAM. Western blot analysis demonstrated that CC inhibited expression of HIF-1α and its downstream target VEGF. Interestingly, CC also suppressed VEGFR2 phosphorylation and consequently attenuated AKT and ERK phosphorylation. Our findings suggest that CC downregulates VEGF-induced angiogenesis by modulating HIF-1α/VEGFR2 pathway and recommend it (CC) as a potential therapeutic drug for breast cancer treatment. Copyright © 2017 Elsevier Inc. All rights reserved.

Protein Phosphotyrosine Phosphatase 1B (PTP1B) in Calpain-dependent Feedback Regulation of Vascular Endothelial Growth Factor Receptor (VEGFR2) in Endothelial Cells: IMPLICATIONS IN VEGF-DEPENDENT ANGIOGENESIS AND DIABETIC WOUND HEALING.

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Zhang, Yixuan; Li, Qiang; Youn, Ji Youn; Cai, Hua

2017-01-13

The VEGF/VEGFR2/Akt/eNOS/NO pathway is essential to VEGF-induced angiogenesis. We have previously discovered a novel role of calpain in mediating VEGF-induced PI3K/AMPK/Akt/eNOS activation through Ezrin. Here, we sought to identify possible feedback regulation of VEGFR2 by calpain via its substrate protein phosphotyrosine phosphatase 1B (PTP1B), and the relevance of this pathway to VEGF-induced angiogenesis, especially in diabetic wound healing. Overexpression of PTP1B inhibited VEGF-induced VEGFR2 and Akt phosphorylation in bovine aortic endothelial cells, while PTP1B siRNA increased both, implicating negative regulation of VEGFR2 by PTP1B. Calpain inhibitor ALLN induced VEGFR2 activation, which can be completely blocked by PTP1B overexpression. Calpain activation induced by overexpression or Ca/A23187 resulted in PTP1B cleavage, which can be blocked by ALLN. Moreover, calpain activation inhibited VEGF-induced VEGFR2 phosphorylation, which can be restored by PTP1B siRNA. These data implicate calpain/PTP1B negative feedback regulation of VEGFR2, in addition to the primary signaling pathway of VEGF/VEGFR2/calpain/PI3K/AMPK/Akt/eNOS. We next examined a potential role of PTP1B in VEGF-induced angiogenesis. Endothelial cells transfected with PTP1B siRNA showed faster wound closure in response to VEGF. Aortic discs isolated from PTP1B siRNA-transfected mice also had augmented endothelial outgrowth. Importantly, PTP1B inhibition and/or calpain overexpression significantly accelerated wound healing in STZ-induced diabetic mice. In conclusion, our data for the first time demonstrate a calpain/PTP1B/VEGFR2 negative feedback loop in the regulation of VEGF-induced angiogenesis. Modulation of local PTP1B and/or calpain activities may prove beneficial in the treatment of impaired wound healing in diabetes. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

Expression of growth factor receptors and targeting of EGFR in cholangiocarcinoma cell lines

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Xu, Ling; Hausmann, Martin; Dietmaier, Wolfgang; Kellermeier, Silvia; Pesch, Theresa; Stieber-Gunckel, Manuela; Lippert, Elisabeth; Klebl, Frank; Rogler, Gerhard

2010-01-01

Cholangiocarcinoma (CC) is a malignant neoplasm of the bile ducts or the gallbladder. Targeting of growth factor receptors showed therapeutic potential in palliative settings for many solid tumors. The aim of this study was to determine the expression of seven growth factor receptors in CC cell lines and to assess the effect of blocking the EGFR receptor in vitro. Expression of EGFR (epithelial growth factor receptor), HGFR (hepatocyte growth factor receptor) IGF1R (insulin-like growth factor 1 receptor), IGF2R (insulin-like growth factor 2 receptor) and VEGFR1-3 (vascular endothelial growth factor receptor 1-3) were examined in four human CC cell lines (EGI-1, HuH28, OZ and TFK-1). The effect of the anti-EGFR-antibody cetuximab on cell growth and apoptosis was studied and cell lines were examined for KRAS mutations. EGFR, HGFR and IGFR1 were present in all four cell lines tested. IGFR2 expression was confirmed in EGI-1 and TFK-1. No growth-inhibitory effect was found in EGI-1 cells after incubation with cetuximab. Cetuximab dose-dependently inhibited growth in TFK-1. Increased apoptosis was only seen in TFK-1 cells at the highest cetuximab dose tested (1 mg/ml), with no dose-response-relationship at lower concentrations. In EGI-1 a heterozygous KRAS mutation was found in codon 12 (c.35G>A; p.G12D). HuH28, OZ and TFK-1 lacked KRAS mutation. CC cell lines express a pattern of different growth receptors in vitro. Growth factor inhibitor treatment could be affected from the KRAS genotype in CC. The expression of EGFR itself does not allow prognoses on growth inhibition by cetuximab

Expression of growth factor receptors and targeting of EGFR in cholangiocarcinoma cell lines

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Kellermeier Silvia

2010-06-01

Full Text Available Abstract Background Cholangiocarcinoma (CC is a malignant neoplasm of the bile ducts or the gallbladder. Targeting of growth factor receptors showed therapeutic potential in palliative settings for many solid tumors. The aim of this study was to determine the expression of seven growth factor receptors in CC cell lines and to assess the effect of blocking the EGFR receptor in vitro. Methods Expression of EGFR (epithelial growth factor receptor, HGFR (hepatocyte growth factor receptor IGF1R (insulin-like growth factor 1 receptor, IGF2R (insulin-like growth factor 2 receptor and VEGFR1-3 (vascular endothelial growth factor receptor 1-3 were examined in four human CC cell lines (EGI-1, HuH28, OZ and TFK-1. The effect of the anti-EGFR-antibody cetuximab on cell growth and apoptosis was studied and cell lines were examined for KRAS mutations. Results EGFR, HGFR and IGFR1 were present in all four cell lines tested. IGFR2 expression was confirmed in EGI-1 and TFK-1. No growth-inhibitory effect was found in EGI-1 cells after incubation with cetuximab. Cetuximab dose-dependently inhibited growth in TFK-1. Increased apoptosis was only seen in TFK-1 cells at the highest cetuximab dose tested (1 mg/ml, with no dose-response-relationship at lower concentrations. In EGI-1 a heterozygous KRAS mutation was found in codon 12 (c.35G>A; p.G12D. HuH28, OZ and TFK-1 lacked KRAS mutation. Conclusion CC cell lines express a pattern of different growth receptors in vitro. Growth factor inhibitor treatment could be affected from the KRAS genotype in CC. The expression of EGFR itself does not allow prognoses on growth inhibition by cetuximab.

VEGF induces proliferation of human hair follicle dermal papilla cells through VEGFR-2-mediated activation of ERK

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Li, Wei; Man, Xiao-Yong; Li, Chun-Ming; Chen, Jia-Qi; Zhou, Jiong; Cai, Sui-Qing; Lu, Zhong-Fa; Zheng, Min

2012-01-01

Vascular endothelial growth factor (VEGF) is one of the strongest regulators of physiological and pathological angiogenesis. VEGF receptor 2 (VEGFR-2), the primary receptor for VEGF, is thought to mediate major functional effects of VEGF. Previously, we have localized both VEGF and VEGFR-2 in human hair follicles. In this study, we further defined the expression and roles of VEGFR-2 on human hair follicle dermal papilla (DP) cells. The expression of VEGFR-2 on DP cells was examined by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot analysis separately, and localization of VEGFR-2 was defined by immunofluorescence. The effect of VEGF on DP cells was analyzed by MTT assays and specific inhibitors. Finally, the role of VEGF involved in the signaling pathways was investigated by Western blot. RT-PCR and Western blot analysis demonstrated the expression of VEGFR-2 on DP cells. Immunostaining for VEGFR-2 showed strong signal on cultured human DP cells in vitro. Exogenous VEGF 165 stimulated proliferation of DP cells in a dose-dependent manner. Furthermore, this stimulation was blocked by a VEGFR-2 neutralizing antibody (MAB3571) and an ERK inhibitor (PD98059). VEGF 165 -induced phosphorylation of ERK1/2 was abolished by MAB3571 and PD98059, while the phosphorylation of p38, JNK and AKT were not changed by VEGF 165 . Taken together, VEGFR-2 is expressed on primary human hair follicle DP cells and VEGF induces proliferation of DP cells through VEGFR-2/ERK pathway, but not p38, JNK or AKT signaling. -- Highlights: ► We examine the expression of VEGFR-2 on cultured human dermal papilla (DP) cells. ► VEGF 165 stimulated proliferation of human DP cells in a dose-dependent manner. ► This stimulation was through VEGFR-2-mediated activation of ERK.

Chronic hydrocephalus-induced hypoxia: increased expression of VEGFR-2+ and blood vessel density in hippocampus.

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Dombrowski, S M; Deshpande, A; Dingwall, C; Leichliter, A; Leibson, Z; Luciano, M G

2008-03-18

Chronic hydrocephalus (CH) is a neurological disease characterized by increased cerebrospinal fluid volume and pressure that is often associated with impaired cognitive function. By and large, CH is a complex and heterogeneous cerebrospinal fluid (CSF) disorder where the exact site of brain insult is uncertain. Several mechanisms including neural compression, fiber stretch, and local or global hypoxia have been implicated in the underlying pathophysiology of CH. Specifically, the hippocampus, which plays a significant role in memory processing and is in direct contact with expanding CSF ventricles, may be involved. Using our model of chronic hydrocephalus, we quantified the density of vascular endothelial growth factor receptor 2 (VEGFR-2(+)) neurons, glial, endothelial cells, and blood vessels in hippocampal regions CA1, CA2-3, dentate gyrus and hilus using immunohistochemical and stereological methods. Density and %VEGFR-2(+) cell populations were estimated for CH animals (2-3 weeks vs. 12-16 weeks) and surgical controls (SC). Overall, we found approximately six- to eightfold increase in the cellular density of VEGFR-2(+) and more than double blood vessel density (BVd) in the hippocampus of CH compared with SC. There were no significant regional differences in VEGFR-2(+) cellular and BVd expression in the CH group. VEGFR-2(+) and BVds were significantly related to changes in CSF volume (PVEGFR-2(+) was significantly greater in CH than SC (PVEGFR-2(+) in hippocampus that corresponded to increased BVd. It was unclear whether increased VEGFR-2(+) and blood vessel expression was related to focal compression alone or in combination with global ischemia/hypoxia conditions as previously described. These findings suggest that VEGFR-2 may play an adaptive role in angiogenesis after CH

SiO2-induced release of sVEGFRs from pulmonary macrophages.

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Chao, Jie; Lv, Yan; Chen, Jin; Wang, Jing; Yao, Honghong

2018-01-01

The inhalation of silicon dioxide (SiO 2 ) particles causes silicosis, a stubborn pulmonary disease that is characterized by alveolar inflammation during the early stage. Soluble cytokine receptors (SCRs) play important roles in regulating inflammation by either attenuating or promoting cytokine signaling. However, the role of SCRs in silicosis remains unknown. Luminex assays revealed increased soluble vascular endothelial growth factor receptor (sVEGFR) family levels in the plasma of silicosis patients. In an enzyme-linked immunosorbent assay (ELISA), cells from the differentiated human monocytic cell line U937 released sVEGFR family proteins after exposure to SiO 2 (50μg/cm 2 ). Further Western blot experiments revealed that VEGFR expression was also elevated in U937 cells. In contrast, levels of sVEGFR family members did not change in the supernatants of human umbilical vein endothelial cells (HUVECs) after exposure to SiO 2 (50μg/cm 2 ). Interestingly, VEGFR expression in HUVECs decreased after SiO 2 treatment. In a scratch assay, HUVECs exhibited cell migration ability, indicating the acquisition of mesenchymal properties. Our findings highlight the important role of sVEGFRs in both inflammation and fibrosis induced by SiO 2 , suggesting a possible mechanism for the fibrogenic effects observed in pulmonary diseases associated with fibrosis. Copyright © 2017 Elsevier B.V. All rights reserved.

Expression and localization of VEGFR-2 in hair follicles during induced hair growth in mice.

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Wu, Xian-Jie; Jing, Jing; Lu, Zhong-Fa; Zheng, Min

2018-06-16

Recently, VEGFR-2 has been detected not only in vascular and lymphatic endothelial cells but also in some non-vascular endothelial cells, particularly human hair follicles, sebaceous glands, and sweat glands. In addition, VEGFR-2 has been confirmed to play direct roles in hair follicle keratinocyte regulation beyond simply angiogenesis. To elucidate whether VEGFR-2 activation plays a role in hair follicle cycling regulation, immunofluorescence of VEGFR-2 expression was performed during hair cycling of the dorsum of the mouse induced by hair plucking. We observed that staining for VEGFR-2 in hair follicles during anagen II and IV was much stronger than during anagen VI, catagen and telogen. During anagen II, intense staining for VEGFR-2 was observed on the keratinocyte strands of the hair follicle. Subsequently, we detected intense staining for VEGFR-2 in the ORS, IRS and hair bulb during anagen IV. Moderate staining for VEGFR-2 was detected in the ORS and hair bulb, but staining was most intense in IRS during anagen VI. During catagen, staining for VEGFR-2 in the IRS remained intense, while staining in the ORS and hair bulb was significantly weakened and was negative in the dermal papilla. During telogen, we detected VEGFR-2 in germ cells, cap, and club hair adjoining the epidermis. In conclusion, VEGFR-2 was expressed on the hair follicles of the dorsum of the mouse and varied in expression on the mouse hair follicles during hair cycling, suggesting that VEGFR-2 may exert roles in hair cycle regulation in hair follicles on the dorsum of mice.

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

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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

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

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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.

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.

Ligand-receptor assay for evaluation of functional activity of human recombinant VEGF and VEGFR-1 extracellular fragment.

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Leopol'd, A V; Baklaushev, V P; Korchagina, A A; Shein, S A; Grinenko, N F; Pavlov, K A; Ryabukhin, I A; Chekhonin, V P

2012-04-01

cDNA encoding VEGF and Ig-like extracellular domains 2-4 of VEGFR-1 (sFlt-1(2-4)) were cloned into prokaryotic expression vectors pET32a and pQE60. Recombinant proteins were purified (metal affinity chromatography) and renatured. Chemiluminescent study for the interaction of recombinant VEGF and sFlt-1(2-4) showed that biotinylated VEGF specifically binds to the polystyrene-immobilized receptor extracellular fragment. Biotinylated recombinant sFlt-1 interacts with immobilized VEGF. Analysis of the interaction of immobilized recombinant VEGFR-1 and VEGF with C6 glioma cells labeled with CFDA-SE (vital fluorescent dye) showed that recombinant VEGFR-1 also binds to native membrane-associated VEGF. Recombinant VEGF was shown to bind to specific receptors expressed on the surface of C6 glioma cells. Functional activity of these proteins was confirmed by ligand-receptor assay for VEGF and VEGFR-1 (sFlt-1) and quantitative chemiluminescent detection.

Glycan-deficient PrP stimulates VEGFR2 signaling via glycosaminoglycan.

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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. Copyright © 2016 Elsevier Inc. All rights reserved.

Celecoxib alleviates tamoxifen-instigated angiogenic effects by ROS-dependent VEGF/VEGFR2 autocrine signaling

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Kumar, B N Prashanth; Rajput, Shashi; Dey, Kaushik Kumar; Parekh, Aditya; Das, Subhasis; Mazumdar, Abhijit; Mandal, Mahitosh

2013-01-01

Tamoxifen (TAM) is widely used in the chemotherapy of breast cancer and as a preventive agent against recurrence after surgery. However, extended TAM administration for breast cancer induces increased VEGF levels in patients, promoting new blood vessel formation and thereby limiting its efficacy. Celecoxib (CXB), a selective COX-2 inhibitor, suppresses VEGF gene expression by targeting the VEGF promoter responsible for its inhibitory effect. For this study, we had selected CXB as non-steroidal anti-inflammatory drug in combination with TAM for suppressing VEGF expression and simultaneously reducing doses of both the drugs. The effects of CXB combined with TAM were examined in two human breast cancer cell lines in culture, MCF7 and MDA-MB-231. Assays of proliferation, apoptosis, angiogenesis, metastasis, cell cycle distribution, and receptor signaling were performed. Here, we elucidated how the combination of TAM and CXB at nontoxic doses exerts anti-angiogenic effects by specifically targeting VEGF/VEGFR2 autocrine signaling through ROS generation. At the molecular level, TAM-CXB suppresses VHL-mediated HIF-1α activation, responsible for expression of COX-2, MMP-2 and VEGF. Besides low VEGF levels, TAM-CXB also suppresses VEGFR2 expression, confirmed through quantifying secreted VEGF levels, luciferase and RT-PCR studies. Interestingly, we observed that TAM-CXB was effective in blocking VEGFR2 promoter induced expression and further 2 fold decrease in VEGF levels was observed in combination than TAM alone in both cell lines. Secondly, TAM-CXB regulated VEGFR2 inhibits Src expression, responsible for tumor progression and metastasis. FACS and in vivo enzymatic studies showed significant increase in the reactive oxygen species upon TAM-CXB treatment. Taken together, our experimental results indicate that this additive combination shows promising outcome in anti-metastatic and apoptotic studies. In a line, our preclinical studies evidenced that this additive

Underexpression of mineralocorticoid receptor in colorectal carcinomas and association with VEGFR-2 overexpression.

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Di Fabio, Francesco; Alvarado, Carlos; Majdan, Agnieszka; Gologan, Adrian; Voda, Linda; Mitmaker, Elliot; Beitel, Lenore K; Gordon, Philip H; Trifiro, Mark

2007-11-01

The human mineralocorticoid receptor (MR) is a steroid receptor widely expressed in colorectal mucosa. A significant role for the MR in the reduction of vascular endothelial growth factor receptor-2 (VEGFR-2) mRNA levels has been demonstrated in vitro. To evaluate a potential contribution of MR to colorectal carcinoma progression, we analyzed the expression of MR in relation to VEGFR-2. Fresh human colorectal cancer tissue and adjacent normal mucosa were harvested from 48 consecutive patients. MR and VEGFR-2 mRNA expression levels were determined by real-time reverse transcriptase-polymerase chain reaction and correlated with clinicopathological parameters. A decline of MR expression was observed in all carcinomas compared to normal mucosa. Expression of MR was a median of 11-fold lower in carcinoma compared to the normal mucosa, irrespective of the location, size, stage, and differentiation. MR was a median of 20-fold underexpressed in carcinomas with VEGFR-2 overexpression vs only 9-fold in carcinomas with VEGFR-2 underexpression (p = 0.035, Mann-Whitney test). These findings support the hypothesis that reduction of MR expression may be one of the early events involved in colorectal carcinoma progression. The inverse association between MR and VEGFR-2 expression in carcinoma suggests a potential tumor-suppressive function for MR.

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

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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

Functional convergence of Akt protein with VEGFR-1 in human endothelial progenitor cells exposed to sera from patient with type 2 diabetes mellitus.

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Hassanpour, Mehdi; Rezabakhsh, Aysa; Rahbarghazi, Reza; Nourazarian, Alireza; Nouri, Mohammad; Avci, Çığır Biray; Ghaderi, Shahrooz; Alidadyani, Neda; Bagca, Bakiye Goker; Bagheri, Hesam Saghaei

2017-11-01

Diabetes mellitus type 2 predisposes patients to various microvascular complications. In the current experiment, the potent role of diabetes mellitus was investigated on the content of VEGFR-1, -2, Tie-1 and -2, and Akt in human endothelial progenitor cells. The gene expression profile of mTOR and Hedgehog signaling pathways were measured by PCR array. The possible crosstalk between RTKs, mTOR and Hedgehog signaling was also studied by bioinformatic analysis. Endothelial progenitor cells were incubated with serum from normal and diabetic for 7days. Compared to non-treated cells, diabetic serum-induced cell apoptosis (~2-fold) and prohibited cell migration toward bFGF (p1). ELISA analysis showed that diabetes exposed cells had increased abundance of Tie-1, -2 and VEGFR-2 and reduced amount of VEGFR-1 (p1) in diabetic cells. Western blotting showed a marked reduction in the protein level of Akt after cells exposure to serum from diabetic subjects (p1). PCR array revealed a significant stimulation of both mTOR and Hedgehog signaling pathways in diabetic cells (p1, -2 and Tie-2, but not Tie-1, are master regulators of angiogenesis. There is a crosstalk between RTKs and mTOR signaling by involving P62, GABARAPL1, and HTT genes. It seems that physical interaction and co-expression of Akt decreased the level of VEGFR-1 in diabetic cells. Regarding data from the present experiment, diabetic serum contributed to uncontrolled induction of both mTOR and Hedgehog signaling in endothelial progenitor cells. Diabetes mellitus induces mTOR pathway by involving receptor tyrosine kinases while Hedgehog stimulation is independent of these receptors. Copyright © 2017 Elsevier Inc. All rights reserved.

Crosstalk between VEGF-A/VEGFR2 and GDNF/RET signaling pathways

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Tufro, Alda; Teichman, Jason; Banu, Nazifa; Villegas, Guillermo

2007-01-01

Vascular endothelial growth factor (VEGF-A) plays multiple roles in kidney development: stimulates cell proliferation, survival, tubulogenesis, and branching morphogenesis. However, the mechanism that mediates VEGF-A induced ureteric bud branching is unclear. Glial-derived neurotrophic factor (GDNF) signaling through tyrosine kinase c-RET is the major regulator of ureteric bud branching. Here we examined whether VEGF-A regulates RET signaling. We determined that ureteric bud-derived cells express the main VEGF-A signaling receptor, VEGFR2 and RET, by RT-PCR, immunoblotting, and immunocytochemistry. We show that the VEGF-A isoform VEGF 165 induces RET-tyr 1062 phosphorylation in addition to VEGFR2 autophosphorylation, that VEGF 165 and GDNF have additive effects on RET-tyr 1062 phosphorylation, and that VEGFR2 and RET co-immunoprecipitate. Functionally, VEGF 165 induces ureteric bud cell proliferation and branching morphogenesis. Similarly, in embryonic kidney explants VEGF 165 induces RET-tyr 1062 phosphorylation and upregulates GDNF. These findings provide evidence for a novel cooperative interaction between VEGFR2 and RET that mediates VEGF-A functions in ureteric bud cells

P2Y2 Receptor and EGFR Cooperate to Promote Prostate Cancer Cell Invasion via ERK1/2 Pathway.

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Li, Wei-Hua; Qiu, Ying; Zhang, Hong-Quan; Tian, Xin-Xia; Fang, Wei-Gang

2015-01-01

As one member of G protein-coupled P2Y receptors, P2Y2 receptor can be equally activated by extracellular ATP and UTP. Our previous studies have proved that activation of P2Y2 receptor by extracellular ATP could promote prostate cancer cell invasion and metastasis in vitro and in vivo via regulating the expressions of some epithelial-mesenchymal transition/invasion-related genes (including IL-8, E-cadherin, Snail and Claudin-1), and the most significant change in expression of IL-8 was observed after P2Y2 receptor activation. However, the signaling pathway downstream of P2Y2 receptor and the role of IL-8 in P2Y2-mediated prostate cancer cell invasion remain unclear. Here, we found that extracellular ATP/UTP induced activation of EGFR and ERK1/2. After knockdown of P2Y2 receptor, the ATP -stimulated phosphorylation of EGFR and ERK1/2 was significantly suppressed. Further experiments showed that inactivation of EGFR and ERK1/2 attenuated ATP-induced invasion and migration, and suppressed ATP-mediated IL-8 production. In addition, knockdown of IL-8 inhibited ATP-mediated invasion and migration of prostate cancer cells. These findings suggest that P2Y2 receptor and EGFR cooperate to upregulate IL-8 production via ERK1/2 pathway, thereby promoting prostate cancer cell invasion and migration. Thus blocking of the P2Y2-EGFR-ERK1/2 pathway may provide effective therapeutic interventions for prostate cancer.

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.

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

International Nuclear Information System (INIS)

Patten, Steven G; Adamcic, Una; Lacombe, Kristen; Minhas, Kanwal; Skowronski, Karolina; Coomber, Brenda L

2010-01-01

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. 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. 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 stabilization of colorectal microvessels, but no

Targeting TORC1/2 Enhances Sensitivity to EGFR Inhibitors in Head and Neck Cancer Preclinical Models1

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Cassell, Andre; Freilino, Maria L; Lee, Jessica; Barr, Sharon; Wang, Lin; Panahandeh, Mary C; Thomas, Sufi M; Grandis, Jennifer R

2012-01-01

Head and neck squamous cell carcinoma (HNSCC) is characterized by overexpression of the epidermal growth factor receptor (EGFR) where treatments targeting EGFR have met with limited clinical success. Elucidation of the key downstream-pathways that remain activated in the setting of EGFR blockade may reveal new therapeutic targets. The present study was undertaken to test the hypothesis that inhibition of the mammalian target of rapamycin (mTOR) complex would enhance the effects of EGFR blockade in HNSCC preclinical models. Treatment of HNSCC cell lines with the newly developed TORC1/TORC2 inhibitor OSI-027/ASP4876 resulted in dose-dependent inhibition of proliferation with abrogation of phosphorylation of known downstream targets including phospho-AKT (Ser473), phospho-4E-BP1, phospho-p70s6K, and phospho-PRAS40. Furthermore, combined treatment with OSI-027 and erlotinib resulted in enhanced biochemical effects and synergistic growth inhibition in vitro. Treatment of mice bearing HNSCC xenografts with a combination of the Food and Drug Administration (FDA)-approved EGFR inhibitor cetuximab and OSI-027 demonstrated a significant reduction of tumor volumes compared with either treatment alone. These findings suggest that TORC1/TORC2 inhibition in conjunction with EGFR blockade represents a plausible therapeutic strategy for HNSCC. PMID:23226094

VEGFR-2 expression in HCC, dysplastic and regenerative liver nodules, and correlation with pre-biopsy Dynamic Contrast Enhanced CT

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Thaiss, W.M., E-mail: wolfgang.thaiss@med.uni-tuebingen.de [Eberhard Karls University, Department of Radiology, Diagnostic and Interventional Radiology, Hoppe-Seyler-Str. 3, D-72076 Tuebingen (Germany); Kaufmann, S., E-mail: sascha.kaufmann@med.uni-tuebingen.de [Eberhard Karls University, Department of Radiology, Diagnostic and Interventional Radiology, Hoppe-Seyler-Str. 3, D-72076 Tuebingen (Germany); Kloth, C., E-mail: christopher.kloth@med.uni-tuebingen.de [Eberhard Karls University, Department of Radiology, Diagnostic and Interventional Radiology, Hoppe-Seyler-Str. 3, D-72076 Tuebingen (Germany); Nikolaou, K., E-mail: konstantin.nikolaou@med.uni-tuebingen.de [Eberhard Karls University, Department of Radiology, Diagnostic and Interventional Radiology, Hoppe-Seyler-Str. 3, D-72076 Tuebingen (Germany); Bösmüller, H., E-mail: hans.boesmueller@med.uni-tuebingen.de [Eberhard Karls University, Department of Pathology, Liebermeisterstraße 8, D-72076 Tuebingen (Germany); Horger, M., E-mail: Marius.Horger@med.uni-tuebingen.de [Eberhard Karls University, Department of Radiology, Diagnostic and Interventional Radiology, Hoppe-Seyler-Str. 3, D-72076 Tuebingen (Germany)

2016-11-15

Highlights: • VEGFR-2-expression levels vary between HCC, dysplastic and regenerative liver nodules. • Perfusion parameters vary between these groups in blood flow, blood volume and HPI. • Strong correlations were observed between perfusion parameters and VEGFR-2-expression. • The results might influence diagnosis and therapy of anti-vascular therapeutic regimes. - Abstract: Purpose: To evaluate whether VEGFR-2-expression in hepatocellular carcinoma (HCC), dysplastic (DLN) and regenerative liver nodules (RLN) correlates with pre-histology, in vivo Dynamic Contrast Enhanced-Computed Tomography (DCE-CT) data as VEGFR-2-expression affects prognosis and therapeutic options. Materials and methods: 34 patients (63.6 ± 8.9 years, 7 females) underwent liver biopsy or surgery due to suspected HCC or dysplastic nodules after DCE-CT between 2009 and 2015 with no previous chemo- or interventional therapy. Immunohistochemistry staining for VEGFR-2 was performed using Immunoreactive-Remmele-Stegner-Score (IRS) for quantification. A 128-row CT-scanner was used for DCE-CT with assessment of perfusion parameters blood flow (BF), blood volume (BV), arterial liver perfusion (ALP), portal venous perfusion (PVP), and hepatic perfusion index (HPI). Results: Histology confirmed HCC (n = 10), DLN (n = 7) and RLN (n = 34). Mean IRS for VEGFR-2 in HCCs was 9.1 ± 3.0, 7.3 ± 1.6 for DLN and 5.2 ± 2.8 for RLN (p = 0.0004 for HCC vs. RLN). Perfusion values varied significantly between all three groups for BF and HPI (p < 0.001 and p < 0.0001) and for BV in HCC vs. RLN (p < 0.0001) and DLN vs. RLN (p = 0.0019). Strong correlations between VEGFR-2-IRS and perfusion parameters were observed for BF in HCC (r = 0.88, p < 0.01) and HPI in HCC and DLN (r = 0.85, p < 0.04; r = 0.9, p < 0.01). Conclusion: Immunostaining revealed different VEGFR-2-expression levels in HCC, dysplastic and regenerative liver nodules. Perfusion markers blood flow, blood volume and hepatic perfusion index

Gremlin promotes retinal pigmentation epithelial (RPE) cell proliferation, migration and VEGF production via activating VEGFR2-Akt-mTORC2 signaling.

Science.gov (United States)

Liu, Yuan; Chen, Zhijun; Cheng, Haixia; Chen, Juan; Qian, Jing

2017-01-03

Retinopathy of prematurity (ROP) is characterized by late-phase pathologic retinal vasoproliferation. Gremlin is a novel vascular endothelial growth factors (VEGF) receptor 2 (VEGFR2) agonist and promotes angiogenic response. We demonstrated that gremlin expression was significantly increased in retinas of ROP model mice, which was correlated with VEGF upregulation. In retinal pigmentation epithelial (RPE) cells, gremlin activated VEGFR2-Akt-mTORC2 (mammalian target of rapamycin complex 2) signaling, and promoted cell proliferation, migration and VEGF production. VEGFR inhibition (by SU5416) or shRNA knockdown almost abolished gremlin-mediated pleiotropic functions in RPE cells. Further, pharmacological inhibition of Akt-mTOR, or shRNA knockdown of key mTORC2 component (Rictor or Sin1) also attenuated gremlin-exerted activities in RPE cells. We conclude that gremlin promotes RPE cell proliferation, migration and VEGF production possibly via activating VEGFR2-Akt-mTORC2 signaling. Gremlin could be a novel therapeutic target of ROP or other retinal vasoproliferation diseases.

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

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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

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

Czech Academy of Sciences Publication Activity Database

Hamerlik, P.; Lathia, J.D.; Rasmussen, R.; Wu, Q.; Bartkova, J.; Lee, M.; Moudrý, Pavel; Bartek, J. Jr.; Fischer, W.; Lukas, J.; Rich, J.N.; Bartek, Jiří

2012-01-01

Roč. 209, č. 3 (2012), s. 507-520 ISSN 0022-1007 Grant - others:Danish Council for Independent Research /Medical Sciences(DK) ID4765/11-105457; MZd(CZ) NT11065; MŠMT(CZ) CZ.1.07/2.3.00/20.0019; MŠMT(CZ) CZ.1.05/2.1.00/01.0030; NIH(US) NS054276; NIH(US) CA129958; NIH(US) CA116659; NRSA(US) CA142159 Program:NT Institutional research plan: CEZ:AV0Z50520514 Institutional support: RVO:68378050 Keywords : VEGFR2 * cancer * GBM Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 13.214, year: 2012

Molecular imaging reveals elevated VEGFR-2 expression in retinal capillaries in diabetes: a novel biomarker for early diagnosis.

Science.gov (United States)

Sun, Dawei; Nakao, Shintaro; Xie, Fang; Zandi, Souska; Bagheri, Abouzar; Kanavi, Mozhgan Rezaei; Samiei, Shahram; Soheili, Zahra-Soheila; Frimmel, Sonja; Zhang, Zhongyu; Ablonczy, Zsolt; Ahmadieh, Hamid; Hafezi-Moghadam, Ali

2014-09-01

Diabetic retinopathy (DR) is a microvascular complication of diabetes and a leading cause of vision loss. Biomarkers and methods for early diagnosis of DR are urgently needed. Using a new molecular imaging approach, we show up to 94% higher accumulation of custom designed imaging probes against vascular endothelial growth factor receptor 2 (VEGFR-2) in retinal and choroidal vessels of diabetic animals (P<0.01), compared to normal controls. More than 80% of the VEGFR-2 in the diabetic retina was in the capillaries, compared to 47% in normal controls (P<0.01). Angiography in rabbit retinas revealed microvascular capillaries to be the location for VEGF-A-induced leakage, as expressed by significantly higher rate of fluorophore spreading with VEGF-A injection when compared to vehicle control (26±2 vs. 3±1 μm/s, P<0.05). Immunohistochemistry showed VEGFR-2 expression in capillaries of diabetic animals but not in normal controls. Macular vessels from diabetic patients (n=7) showed significantly more VEGFR-2 compared to nondiabetic controls (n=5) or peripheral retinal regions of the same retinas (P<0.01 in both cases). Here we introduce a new approach for early diagnosis of DR and VEGFR-2 as a molecular marker. VEGFR-2 could become a key diagnostic target, one that might help to prevent retinal vascular leakage and proliferation in diabetic patients. © FASEB.

High levels of circulating VEGFR2+ Bone marrow-derived progenitor cells correlate with metastatic disease in patients with pediatric solid malignancies.

Science.gov (United States)

Taylor, Melissa; Rössler, Jochen; Geoerger, Birgit; Laplanche, Agnès; Hartmann, Olivier; Vassal, Gilles; Farace, Françoise

2009-07-15

Pediatric solid malignancies display important angiogenic potential, and blocking tumor angiogenesis represents a new therapeutic approach for these patients. Recent studies have evidenced rare circulating cells with endothelial features contributing to tumor neovascularization and have shown the pivotal role of bone marrow-derived (BMD) progenitor cells in metastatic disease progression. We measured these cells in patients with pediatric solid malignancies as a prerequisite to clinical trials with antiangiogenic therapy. Peripheral blood was drawn from 45 patients with localized (n = 23) or metastatic (n = 22) disease, and 20 healthy subjects. Subsets of circulating vascular endothelial growth factor receptor (VEGFR)2+-BMD progenitor cells, defined as CD45-CD34+VEGFR2(KDR)+7AAD- and CD45(dim)CD34+VEGFR2+7AAD- events, were measured in progenitor-enriched fractions by flow cytometry. Mature circulating endothelial cells (CEC) were measured in whole blood as CD31+CD146+CD45-7AAD- viable events. Data were correlated with VEGF and sVEGFR2 plasma levels. The CD45-CD34+VEGFR2(KDR)+7AAD- subset represented <0.003% of circulating BMD progenitor cells (< or =0.05 cells/mL). However, the median level (range) of the CD45(dim)CD34+VEGFR2+7AAD- subset was higher in patients compared with healthy subjects, 1.5% (0%-10.3%) versus 0.3% (0%-1.6%) of circulating BMD progenitors (P < 0.0001), and differed significantly between patients with localized and metastatic disease, 0.7% (0%-8.6%) versus 2.9% (0.6%-10.3%) of circulating BMD progenitors (P < 0.001). Median CEC value was 7 cells/mL (0-152 cells/mL) and similar in all groups. Unlike VEGFR2+-BMD progenitors, neither CECs, VEGF, or sVEGFR2 plasma levels correlated with disease status. High levels of circulating VEGFR2+-BMD progenitor cells correlated with metastatic disease. Our study provides novel insights for angiogenesis mechanisms in pediatric solid malignancies for which antiangiogenic targeting of VEGFR2+-BMD progenitors

Phosphorylated EGFR expression may predict outcome of EGFR-TKIs therapy for the advanced NSCLC patients with wild-type EGFR

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Wang Fen

2012-08-01

Full Text Available Abstract Background EGFR mutation is a strong predictive factor of EGFR-TKIs therapy. However, at least 10% of patients with EGFR wild-type are responsive to TKIs, suggesting that other determinants of outcome besides EGFR mutation might exist. We hypothesized that activation of phosphorylated EGFR could be a potential predictive biomarker to EGFR-TKIs treatment among patients in wild-type EGFR. Method Total of 205 stage IIIb and IV NSCLC patients, tissue samples of whom were available for molecular analysis, were enrolled in this study. The phosphorylation of EGFR at tyrosine 1068 (pTyr1068 and 1173 (pTyr1173 were assessed by immunohistochemistry, and EGFR mutations were detected by denaturing high performance liquid chromatograph (DHPLC. Results Among 205 patients assessable for EGFR mutation and phosphorylation analysis, 92 (44.9% were EGFR mutant and 165 patients (57.6% had pTyr1173 expression. Superior progression-free survival (PFS was seen after EGFR-TKIs therapy in patients with pTyr1068 expression compared to pTyr1068 negative ones (median PFS 7.0 months vs. 1.2 months, P P = 0.016. In subgroup of patients with wild-type EGFR, pTyr1068 expression positive ones had a significantly prolonged PFS (4.2 months vs.1.2 months P  Conclusion pTyr1068 may be a predictive biomarker for screening the population for clinical response to EGFR-TKIs treatment; especially for patients with wild-type EGFR.

Inhibition of Epidermal Growth Factor Receptor and Vascular Endothelial Growth Factor Receptor Phosphorylation on Tumor-Associated Endothelial Cells Leads to Treatment of Orthotopic Human Colon Cancer in Nude Mice

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Takamitsu Sasaki

2007-12-01

Full Text Available The purpose of our study was to determine whether the dual inhibition of epidermal growth factor receptor (EGFR and vascular endothelial growth factor receptor (VEGFR signaling pathways in tumor-associated endothelial cells can inhibit the progressive growth of human colon carcinoma in the cecum of nude mice. SW620CE2 human colon cancer cells growing in culture and orthotopically in the cecum of nude mice expressed a high level of transforming growth factor alpha (TGF-α and vascular endothelial growth factor (VEGF but were negative for EGFR, human epidermal growth factor receptor 2 (HER2, VEGFR. Double immunofluorescence staining revealed that tumorassociated endothelial cells expressed EGFR, VEGFR2, phosphorylated EGFR (pEGFR, phosphorylated VEGFR (pVEGFR. Treatment of mice with either 7H-pyrrolo [2,3-d]-pyrimidine lead scaffold (AEE788; an inhibitor of EGFR and VEGFR tyrosine kinase or CPT-11 as single agents significantly inhibited the growth of cecal tumors (P < .01; this decrease was even more pronounced with AEE788 combined with CPT-11 (P < .001. AEE788 alone or combined with CPT-11 also inhibited the expression of pEGFR and pVEGFR on tumor-associated endothelial cells, significantly decreased vascularization and tumor cell proliferation, increased the level of apoptosis in both tumorassociated endothelial cells and tumor cells. These data demonstrate that targeting EGFR and VEGFR signaling on tumor-associated endothelial cells provides a viable approach for the treatment of colon cancer.

Anti-S1P Antibody as a Novel Therapeutic Strategy for VEGFR TKI-Resistant Renal Cancer.

Science.gov (United States)

Zhang, Liang; Wang, Xiaoen; Bullock, Andrea J; Callea, Marcella; Shah, Harleen; Song, Jiaxi; Moreno, Kelli; Visentin, Barbara; Deutschman, Douglas; Alsop, David C; Atkins, Michael B; Mier, James W; Signoretti, Sabina; Bhasin, Manoj; Sabbadini, Roger A; Bhatt, Rupal S

2015-04-15

VEGFR2 tyrosine kinase inhibition (TKI) is a valuable treatment approach for patients with metastatic renal cell carcinoma (RCC). However, resistance to treatment is inevitable. Identification of novel targets could lead to better treatment for patients with TKI-naïve or -resistant RCC. In this study, we performed transcriptome analysis of VEGFR TKI-resistant tumors in a murine model and discovered that the SPHK-S1P pathway is upregulated at the time of resistance. We tested sphingosine-1-phosphate (S1P) pathway inhibition using an anti-S1P mAb (sphingomab), in two mouse xenograft models of RCC, and assessed tumor SPHK expression and S1P plasma levels in patients with metastatic RCC. Resistant tumors expressed several hypoxia-regulated genes. The SPHK1 pathway was among the most highly upregulated pathways that accompanied resistance to VEGFR TKI therapy. SPHK1 was expressed in human RCC, and the product of SPHK1 activity, S1P, was elevated in patients with metastatic RCC, suggesting that human RCC behavior could, in part, be due to overproduction of S1P. Sphingomab neutralization of extracellular S1P slowed tumor growth in both mouse models. Mice bearing tumors that had developed resistance to sunitinib treatment also exhibited tumor growth suppression with sphingomab. Sphingomab treatment led to a reduction in tumor blood flow as measured by MRI. Our findings suggest that S1P inhibition may be a novel therapeutic strategy in patients with treatment-naïve RCC and also in the setting of resistance to VEGFR TKI therapy. ©2015 American Association for Cancer Research.

Sindbis Virus-Pseudotyped Lentiviral Vectors Carrying VEGFR2-Specific Nanobody for Potential Transductional Targeting of Tumor Vasculature.

Science.gov (United States)

Ahani, Roshank; Roohvand, Farzin; Cohan, Reza Ahangari; Etemadzadeh, Mohammad Hossein; Mohajel, Nasir; Behdani, Mahdi; Shahosseini, Zahra; Madani, Navid; Azadmanesh, Kayhan

2016-11-01

Introduction of selectivity/specificity into viral-based gene delivery systems, such as lentiviral vectors (LVs), is crucial in their systemic administration for cancer gene therapy. The pivotal role of tumor-associated endothelial cells (TAECs) in tumor angiogenesis and overexpression of vascular endothelial growth factor receptor-2 (VEGFR2 or KDR) in TAECs makes them a potent target in cancer treatment. Herein, we report the development of VEGFR2-targeted LVs pseudotyped with chimeric sindbis virus E2 glycoprotein (cSVE2s). For this purpose, either sequence of a VEGFR2-specific nanobody or its natural ligand (VEGF 121 ) was inserted into the binding site of sindbis virus E2 glycoprotein. In silico modeling data suggested that the inserted targeting motifs were exposed in the context of cSVE2s. Western blot analysis of LVs indicated the incorporation of cSVE2s into viral particles. Capture ELISA demonstrated the specificity/functionality of the incorporated cSVE2s. Transduction of 293/KDR (expressing VEGFR2) or 293T cells (negative control) by constructed LVs followed by fluorescent microscopy and flow cytometric analyses indicated selective transduction of 293/KDR cells (30 %) by both targeting motifs compared to 293T control cells (1-2 %). These results implied similar targeting properties of VEGFR2-specific nanobody compared to the VEGF 121 and indicated the potential for transductional targeting of tumor vasculature by the nanobody displaying LVs.

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

International Nuclear Information System (INIS)

Yu, Yao; Cai, Wei; Pei, Chong-gang; Shao, Yi

2015-01-01

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

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.

BRCA2, EGFR, and NTRK mutations in mismatch repair-deficient colorectal cancers with MSH2 or MLH1 mutations.

Science.gov (United States)

Deihimi, Safoora; Lev, Avital; Slifker, Michael; Shagisultanova, Elena; Xu, Qifang; Jung, Kyungsuk; Vijayvergia, Namrata; Ross, Eric A; Xiu, Joanne; Swensen, Jeffrey; Gatalica, Zoran; Andrake, Mark; Dunbrack, Roland L; El-Deiry, Wafik S

2017-06-20

Deficient mismatch repair (MMR) and microsatellite instability (MSI) contribute to ~15% of colorectal cancer (CRCs). We hypothesized MSI leads to mutations in DNA repair proteins including BRCA2 and cancer drivers including EGFR. We analyzed mutations among a discovery cohort of 26 MSI-High (MSI-H) and 558 non-MSI-H CRCs profiled at Caris Life Sciences. Caris-profiled MSI-H CRCs had high mutation rates (50% vs 14% in non-MSI-H, P MLH1-mutant CRCs showed higher mutation rates in BRCA2 compared to non-MSH2/MLH1-mutant tumors (38% vs 6%, P MLH1-mutant CRCs included 75 unique mutations not known to occur in breast or pancreatic cancer per COSMIC v73. Only 5 deleterious BRCA2 mutations in CRC were previously reported in the BIC database as germ-line mutations in breast cancer. Some BRCA2 mutations were predicted to disrupt interactions with partner proteins DSS1 and RAD51. Some CRCs harbored multiple BRCA2 mutations. EGFR was mutated in 45.5% of MSH2/MLH1-mutant and 6.5% of non-MSH2/MLH1-mutant tumors (P MLH1-mutant CRC including NTRK1 I699V, NTRK2 P716S, and NTRK3 R745L. Our findings have clinical relevance regarding therapeutic targeting of BRCA2 vulnerabilities, EGFR mutations or other identified oncogenic drivers such as NTRK in MSH2/MLH1-mutant CRCs or other tumors with mismatch repair deficiency.

Levels of circulating CD45dimCD34+VEGFR2+ progenitor cells correlate with outcome in metastatic renal cell carcinoma patients treated with tyrosine kinase inhibitors

Science.gov (United States)

Farace, F; Gross-Goupil, M; Tournay, E; Taylor, M; Vimond, N; Jacques, N; Billiot, F; Mauguen, A; Hill, C; Escudier, B

2011-01-01

Background: Predicting the efficacy of antiangiogenic therapy would be of clinical value in patients (pts) with metastatic renal cell carcinoma (mRCC). We tested the hypothesis that circulating endothelial cell (CEC), bone marrow-derived CD45dimCD34+VEGFR2+ progenitor cell or plasma angiogenic factor levels are associated with clinical outcome in mRCC pts undergoing treatment with tyrosine kinase inhibitors (TKI). Methods: Fifty-five mRCC pts were prospectively monitored at baseline (day 1) and day 14 during treatment (46 pts received sunitinib and 9 pts received sorafenib). Circulating endothelial cells (CD45−CD31+CD146+7-amino-actinomycin (7AAD)− cells) were measured in 1 ml whole blood using four-color flow cytometry (FCM). Circulating CD45dimCD34+VEGFR2+7AAD− progenitor cells were measured in progenitor-enriched fractions by four-color FCM. Plasma VEGF, sVEGFR2, SDF-1α and sVCAM-1 levels were determined by ELISA. Correlations between baseline CEC, CD45dimCD34+VEGFR2+7AAD− progenitor cells, plasma factors, as well as day 1–day 14 changes in CEC, CD45dimCD34+VEGFR2+7AAD− progenitor, plasma factor levels, and response to TKI, progression-free survival (PFS) and overall survival (OS) were examined. Results: No significant correlation between markers and response to TKI was observed. No association between baseline CEC, plasma VEGF, sVEGFR-2, SDF-1α, sVCAM-1 levels with PFS and OS was observed. However, baseline CD45dimCD34+VEGFR2+7AAD− progenitor cell levels were associated with PFS (P=0.01) and OS (P=0.006). Changes in this population and in SDF-1α levels between day 1 and day 14 were associated with PFS (P=0.03, P=0.002). Changes in VEGF and SDF-1α levels were associated with OS (P=0.02, P=0.007). Conclusion: Monitoring CD45dimCD34+VEGFR2+ progenitor cells, plasma VEGF and SDF-1α levels could be of clinical interest in TKI-treated mRCC pts to predict outcome. PMID:21386843

Expression of EGFR and Molecules Downstream to PI3K/Akt, Raf-1-MEK-1-MAP (Erk1/2, and JAK (STAT3 Pathways in Invasive Lung Adenocarcinomas Resected at a Single Institution

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Alba Fabiola Torres

2014-01-01

Full Text Available Therapies targeting EGFR are effective in treating tumors that harbor molecular alterations; however, there is heterogeneity in long-term response to these therapies. We retrospectively analyzed protein expression of EGFR, Stat3, phospho-Akt, and phospho-Erk1/2 by immunohistochemistry in a series of resected cases from a single institution, correlated with clinicopathological variables. There were 96 patients, with the majority of cases being of low stage tumors (17 pT1a, 23 pT1b, 30 pT2a, and 18 pT2b. Histologic subtypes were 45 acinar predominant, 2 cribriform, 25 solid, 7 papillary, 11 lepidic, and 4 mucinous tumors. The EGFR score was higher in tumors with vascular invasion (P=0.013, in solid and cribriform acinar histology, and in high stage tumors (P=0.006 and P=0.01. EGFR was more likely overexpressed in solid compared to lepidic tumors (P=0.02. Acinar tumors had the highest rate of ERK1/2 positivity (19%. There was a strong correlation among positivity for ERCC1 and other markers, including STAT3 (P=0.003, Akt (P=0.02, and ERK1/ERK2 (P=0.0005. Expression of molecules downstream to EGFR varied from 12% to 31% of tumors; however, the expression did not directly correlate to EGFR expression, which may suggest activation of the cascades through different pathways. The correlation of protein expression and the new lung adenocarcinoma classification may help in the understanding of activated pathways of each tumor type, which may act in the oncogenesis and drug resistance of these tumors.

Targeting TORC1/2 Enhances Sensitivity to EGFR Inhibitors in Head and Neck Cancer Preclinical Models

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Andre Cassell

2012-11-01

Full Text Available Head and neck squamous cell carcinoma (HNSCC is characterized by overexpression of the epidermal growth factor receptor (EGFR where treatments targeting EGFR have met with limited clinical success. Elucidation of the key downstream-pathways that remain activated in the setting of EGFR blockade may reveal new therapeutic targets. The present study was undertaken to test the hypothesis that inhibition of the mammalian target of rapamycin (mTOR complex would enhance the effects of EGFR blockade in HNSCC preclinical models. Treatment of HNSCC cell lines with the newly developed TORC1/TORC2 inhibitor OSI-027/ASP4876 resulted in dose-dependent inhibition of proliferation with abrogation of phosphorylation of known downstream targets including phospho-AKT (Ser473, phospho-4E-BP1, phospho-p70s6K, and phospho-PRAS40. Furthermore, combined treatment with OSI-027 and erlotinib resulted in enhanced biochemical effects and synergistic growth inhibition in vitro. Treatment of mice bearing HNSCC xenografts with a combination of the Food and Drug Administration (FDA-approved EGFR inhibitor cetuximab and OSI-027 demonstrated a significant reduction of tumor volumes compared with either treatment alone. These findings suggest that TORC1/TORC2 inhibition in conjunction with EGFR blockade represents a plausible therapeutic strategy for HNSCC.

Targeting TORC1/2 enhances sensitivity to EGFR inhibitors in head and neck cancer preclinical models.

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Cassell, Andre; Freilino, Maria L; Lee, Jessica; Barr, Sharon; Wang, Lin; Panahandeh, Mary C; Thomas, Sufi M; Grandis, Jennifer R

2012-11-01

Head and neck squamous cell carcinoma (HNSCC) is characterized by overexpression of the epidermal growth factor receptor (EGFR) where treatments targeting EGFR have met with limited clinical success. Elucidation of the key downstream-pathways that remain activated in the setting of EGFR blockade may reveal new therapeutic targets. The present study was undertaken to test the hypothesis that inhibition of the mammalian target of rapamycin (mTOR) complex would enhance the effects of EGFR blockade in HNSCC preclinical models. Treatment of HNSCC cell lines with the newly developed TORC1/TORC2 inhibitor OSI-027/ASP4876 resulted in dose-dependent inhibition of proliferation with abrogation of phosphorylation of known downstream targets including phospho-AKT (Ser473), phospho-4E-BP1, phospho-p70s6K, and phospho-PRAS40. Furthermore, combined treatment with OSI-027 and erlotinib resulted in enhanced biochemical effects and synergistic growth inhibition in vitro. Treatment of mice bearing HNSCC xenografts with a combination of the Food and Drug Administration (FDA)-approved EGFR inhibitor cetuximab and OSI-027 demonstrated a significant reduction of tumor volumes compared with either treatment alone. These findings suggest that TORC1/TORC2 inhibition in conjunction with EGFR blockade represents a plausible therapeutic strategy for HNSCC.

Hit discovery of 4-amino-N-(4-(3-(trifluoromethyl)phenoxy)pyrimidin-5-yl)benzamide: A novel EGFR inhibitor from a designed small library.

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Elkamhawy, Ahmed; Paik, Sora; Hassan, Ahmed H E; Lee, Yong Sup; Roh, Eun Joo

2017-12-01

Searching for hit compounds within the huge chemical space resembles the attempt to find a needle in a haystack. Cheminformatics-guided selection of few representative molecules of a rationally designed virtual combinatorial library is a powerful tool to confront this challenge, speed up hit identification and cut off costs. Herein, this approach has been applied to identify hit compounds with novel scaffolds able to inhibit EGFR kinase. From a generated virtual library, six 4-aryloxy-5-aminopyrimidine scaffold-derived compounds were selected, synthesized and evaluated as hit EGFR inhibitors. 4-Aryloxy-5-benzamidopyrimidines inhibited EGFR with IC 50 1.05-5.37 μM. Cell-based assay of the most potent EGFR inhibitor hit (10ac) confirmed its cytotoxicity against different cancerous cells. In spite of no EGFR, HER2 or VEGFR1 inhibition was elicited by 4-aryloxy-5-(thio)ureidopyrimidine derivatives, cell-based evaluation suggested them as antiproliferative hits acting by other mechanism(s). Molecular docking study provided a plausible explanation of incapability of 4-aryloxy-5-(thio)ureidopyrimidines to inhibit EGFR and suggested a reasonable binding mode of 4-aryloxy-5-benzamidopyrimidines which provides a basis to develop more optimized ligands. Copyright © 2017 Elsevier Inc. All rights reserved.

VEGF and VEGFR genotyping in the prediction of clinical outcome for HCC patients receiving sorafenib: the ALICE-1 study.

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Scartozzi, Mario; Faloppi, Luca; Svegliati Baroni, Gianluca; Loretelli, Cristian; Piscaglia, Fabio; Iavarone, Massimo; Toniutto, Pierluigi; Fava, Giammarco; De Minicis, Samuele; Mandolesi, Alessandra; Bianconi, Maristella; Giampieri, Riccardo; Granito, Alessandro; Facchetti, Floriana; Bitetto, Davide; Marinelli, Sara; Venerandi, Laura; Vavassori, Sara; Gemini, Stefano; D'Errico, Antonietta; Colombo, Massimo; Bolondi, Luigi; Bearzi, Italo; Benedetti, Antonio; Cascinu, Stefano

2014-09-01

Although new treatment modalities changed the global approach to hepatocellular carcinoma (HCC), this disease still represents a medical challenge. Currently, the therapeutic stronghold is sorafenib, a tyrosine kinase inhibitor (TKI) directed against the vascular endothelial growth factor (VEGF) family. Previous observations suggested that polymorphisms of VEGF and its receptor (VEGFR) genes may regulate angiogenesis and lymphangiogenesis and thus tumour growth control. The aim of our study was to evaluate the role of VEGF and VEGFR polymorphisms in determining the clinical outcome of HCC patients receiving sorafenib. From a multicentre experience 148 samples (tumour or blood samples) of HCC patients receiving sorafenib were tested for VEGF-A, VEGF-C and VEGFR-1,2,3 single nucleotide polymorphisms (SNPs). Patients' progression-free survival (PFS) and overall survival (OS) were analysed. At univariate analysis VEGF-A alleles C of rs25648, T of rs833061, C of rs699947, C of rs2010963, VEGF-C alleles T of rs4604006, G of rs664393, VEGFR-2 alleles C of rs2071559, C of rs2305948 were significant predictors of PFS and OS. At multivariate analysis rs2010963, rs4604006 and BCLC (Barcelona Clinic Liver Cancer) stage resulted to be independent factors influencing PFS and OS. Once prospectively validated, the analysis of VEGF and VEGFR SNPs may represent a clinical tool to better identify HCC patients more likely to benefit from sorafenib. On the other hand, the availability of more accurate predictive factors could help avoiding unnecessary toxicities to potentially resistant patients who may be optimal candidates for different treatments interfering with other tumour molecular pathways. © 2014 UICC.

Interaction between EGFR and EphA2

DEFF Research Database (Denmark)

Larsen, Alice Bjerregaard

2010-01-01

Enhanced or altered epidermal growth factor receptor (EGFR) activity has been reported in many human cancers and several molecular targeting therapies has been developed. However, despite intense research, therapies targeting EGFR have shown conflicting results in clinical studies, indicating...... the involvement of other important molecular players. Several different EGFR mutations have been reported in cancer, one of which is the cancer specific type III EGFR deletion mutant (EGFRvIII, de2-7EGFR, ΔEGFR). In a global search for EGFR and EGFRvIII regulated genes we identified the receptor tyrosine kinase...... (RTK) EphA2. EphA2 belongs to the large Eph-receptor family, which has mainly been associated with neuronal development. More recently, expression of several Eph-receptors has been detected in many different cancer types. Elevated EphA2 expression has been reported in a broad range of human cancer...

Interaction between EGFR and EphA2

DEFF Research Database (Denmark)

Larsen, Alice Bjerregaard

2010-01-01

Enhanced or altered epidermal growth factor receptor (EGFR) activity has been reported in many human cancers and several molecular targeting therapies has been developed. However, despite intense research, therapies targeting EGFR have shown conflicting results in clinical studies, indicating...... the involvement of other important molecular players. Several different EGFR mutations have been reported in cancer, one of which is the cancer specific type III EGFR deletion mutant (EGFRvIII, de2-7EGFR, ¿EGFR). In a global search for EGFR and EGFRvIII regulated genes we identified the receptor tyrosine kinase...... (RTK) EphA2. EphA2 belongs to the large Eph-receptor family, which has mainly been associated with neuronal development. More recently, expression of several Eph-receptors has been detected in many different cancer types. Elevated EphA2 expression has been reported in a broad range of human cancer...

Effects of Chronic Exposure to Sodium Arsenite on Expressions of VEGF and VEGFR2 Proteins in the Epididymis of Rats

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Dai Yan-Ping

2017-01-01

Full Text Available Objective. To study the expressions of VEGF and VEGFR2 at protein level in the epididymis of rats with arsenism. Methods. Forty male Sprague-Dawley rats were randomly divided into four groups: the high dose arsenic infected group (60.0 mg/L in water, the middle dose arsenic infected group (12.0 mg/L in water, the low dose arsenic infected group (2.4 mg/L in water, and the control group (distilled water. Rats were treated with arsenic through drinking water for 6 consecutive months. At the end of the experiment, the average densitometry values of apoptotic cells in epididymis tubules were determined by TUNEL method; the protein and mRNA levels of VEGF and VEGFR2 were observed by immunohistochemistry, Western blot, and real time fluorescent quantitative PCR, respectively. Results. Compared with the control group, in each infected group, the average densitometry values of apoptotic cells in the epididymis tubules were significantly lower. Compared with control group, protein and mRNA levels of VEGF and VEGFR2 in each infected group were obviously declined. The correlations between protein and mRNA levels of VEGF and VEGFR2 were positively exhibited (r = 0.843, 0.869, p < 0.05. Conclusions. Arsenism affects the expressions of VEGF and VEGFR2 in the epididymis of rats and results in apoptosis of pathophysiology of male infertility.

Administration of Menadione, Vitamin K3, Ameliorates Off-Target Effects on Corneal Epithelial Wound Healing Due to Receptor Tyrosine Kinase Inhibition.

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Rush, Jamie S; Bingaman, David P; Chaney, Paul G; Wax, Martin B; Ceresa, Brian P

2016-11-01

The antiangiogenic receptor tyrosine kinase inhibitor (RTKi), 3-[(4-bromo-2,6-difluorophenyl)methoxy]-5-[[[[4-(1-pyrrolidinyl) butyl] amino] carbonyl]amino]-4-isothiazolecarboxamide hydrochloride, targets VEGFR2 (half maximal inhibitory concentration [IC50] = 11 nM); however, off-target inhibition of epidermal growth factor receptor (EGFR) occurs at higher concentrations. (IC50 = 5.8 μM). This study was designed to determine the effect of topical RTKi treatment on EGF-mediated corneal epithelial wound healing and to develop new strategies to minimize off-target EGFR inhibition. In vitro corneal epithelial wound healing was measured in response to EGF using a transformed human cell line (hTCEpi cells). In vivo corneal wound healing was assessed using a murine model. In these complementary assays, wound healing was measured in the presence of varying RTKi concentrations. Immunoblot analysis was used to examine EGFR and VEGFR2 phosphorylation and the kinetics of EGFR degradation. An Alamar Blue assay measured VEGFR2-mediated cell biology. Receptor tyrosine kinase inhibitor exposure caused dose-dependent inhibition of EGFR-mediated corneal epithelial wound healing in vitro and in vivo. Nanomolar concentrations of menadione, a vitamin K3 analog, when coadministered with the RTKi, slowed EGFR degradation and ameliorated the inhibitory effects on epithelial wound healing both in vitro and in vivo. Menadione did not alter the RTKi's IC50 against VEGFR2 phosphorylation or its inhibition of VEGF-induced retinal endothelial cell proliferation. An antiangiogenic RTKi exhibited off-target effects on the corneal epithelium that can be minimized by menadione without deleteriously affecting its on-target VEGFR2 blockade. These data indicate that menadione has potential as a topical supplement for individuals suffering from perturbations in corneal epithelial homeostasis, especially as an untoward side effect of kinase inhibitors.

Molecular genetic alterations in egfr CA-SSR-1 microsatellite and egfr copy number changes are associated with aggressiveness in thymoma.

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Conti, Salvatore; Gallo, Enzo; Sioletic, Stefano; Facciolo, Francesco; Palmieri, Giovannella; Lauriola, Libero; Evoli, Amelia; Martucci, Robert; Di Benedetto, Anna; Novelli, Flavia; Giannarelli, Diana; Deriu, Gloria; Granone, Pierluigi; Ottaviano, Margaret; Muti, Paola; Pescarmona, Edoardo; Marino, Mirella

2016-03-01

The key role of egfr in thymoma pathogenesis has been questioned following the failure in identifying recurrent genetic alterations of egfr coding sequences and relevant egfr amplification rate. We investigated the role of the non-coding egfr CA simple sequence repeat 1 (CA-SSR-1) in a thymoma case series. We used sequencing and egfr-fluorescence in situ hybridization (FISH) to genotype 43 thymomas; (I) for polymorphisms and somatic loss of heterozygosity of the non-coding egfr CA-SSR-1 microsatellite and (II) for egfr gene copy number changes. We found two prevalent CA-SSR-1 genotypes: a homozygous 16 CA repeat and a heterozygous genotype, bearing alleles with 16 and 20 CA repeats. The average combined allele length was correlated with tumor subtype: shorter sequences were significantly associated with the more aggressive WHO thymoma subtype group including B2/B3, B3 and B3/C histotypes. Four out of 29 informative cases analysed for somatic CA-SSR-1 loss of heterozygosity showed allelic imbalance (AI), 3/4 with loss of the longer allele. By egfr-FISH analysis, 9 out of 33 cases were FISH positive. Moreover, the two integrated techniques demonstrated that 3 out of 4 CA-SSR-1-AI positive cases with short allele relative prevalence showed significantly low or high chromosome 7 "polysomy"/increased gene copy number by egfr-FISH. Our molecular and genetic and follow up data indicated that CA-SSR-1-allelic imbalance with short allele relative prevalence significantly correlated with EGFR 3+ immunohistochemical score, increased egfr Gene Copy Number, advanced stage and with relapsing/metastatic behaviour in thymomas.

TIE-2 and VEGFR kinase activities drive immunosuppressive function of TIE-2-expressing monocytes in human breast tumors.

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Ibberson, Mark; Bron, Sylvian; Guex, Nicolas; Faes-van't Hull, Eveline; Ifticene-Treboux, Assia; Henry, Luc; Lehr, Hans-Anton; Delaloye, Jean-François; Coukos, George; Xenarios, Ioannis; Doucey, Marie-Agnès

2013-07-01

Tumor-associated TIE-2-expressing monocytes (TEM) are highly proangiogenic cells critical for tumor vascularization. We previously showed that, in human breast cancer, TIE-2 and VEGFR pathways control proangiogenic activity of TEMs. Here, we examine the contribution of these pathways to immunosuppressive activity of TEMs. We investigated the changes in immunosuppressive activity of TEMs and gene expression in response to specific kinase inhibitors of TIE-2 and VEGFR. The ability of tumor TEMs to suppress tumor-specific T-cell response mediated by tumor dendritic cells (DC) was measured in vitro. Characterization of TEM and DC phenotype in addition to their interaction with T cells was done using confocal microscopic images analysis of breast carcinomas. TEMs from breast tumors are able to suppress tumor-specific immune responses. Importantly, proangiogenic and suppressive functions of TEMs are similarly driven by TIE-2 and VEGFR kinase activity. Furthermore, we show that tumor TEMs can function as antigen-presenting cells and elicit a weak proliferation of T cells. Blocking TIE-2 and VEGFR kinase activity induced TEMs to change their phenotype into cells with features of myeloid dendritic cells. We show that immunosuppressive activity of TEMs is associated with high CD86 surface expression and extensive engagement of T regulatory cells in breast tumors. TIE-2 and VEGFR kinase activity was also necessary to maintain high CD86 surface expression levels and to convert T cells into regulatory cells. These results suggest that TEMs are plastic cells that can be reverted from suppressive, proangiogenic cells into cells that are able to mediate an antitumoral immune response. ©2013 AACR.

Increased expression of HIF-1α, VEGF-A and its receptors, MMP-2, TIMP-1, and ADAMTS-1 at the venous stenosis of arteriovenous fistula in a mouse model with renal insufficiency

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Misra, Sanjay; Shergill, Uday; Yang, Binxia; Janardhanan, Rajiv; Misra, Khamal D.

2010-01-01

Purpose A mouse model of renal insufficiency with arteriovenous fistula (AVF) and venous stenosis was created. We tested the hypothesis that there is increased gene expression of hypoxia inducible factor-1 alpha (HIF-1α), vascular endothelial growth factor- A (VEGF-A) and its receptors (VEGFR-1, -2), matrix metalloproteinase-2 (MMP-2), -9 (MMP-9), tissue inhibitor of metalloproteinase-1, -2 (TIMP-1, -2), and a disintegrin and metalloproteinase thrombospondin-1 (ADAMTS-1) at the venous stenosis. Materials and methods Nineteen male C57BL/6 mice underwent a left nephrectomy and a surgical occlusion of the right upper pole to induce renal insufficiency and characterized in eight mice. Twenty eight days later, an AVF (n=11) was created from the right carotid artery to ipsilateral jugular vein and the mice were sacrificed at day 7 (n=4) and day 14 (n=4). The outflow and control veins were removed for gene expression. Three mice were sacrificed at day 28 for histologic analysis. Results The mean serum blood urea nitrogen remained significantly elevated for 8 weeks when compared to baseline (P<0.05). By day 7, there was a significant increase in the expression of HIF-1α, VEGF-A, VEGFR-1, VEGFR-2, MMP-2, TIMP-1, and ADAMTS-1 at the outflow vein with HIF-1α and TIMP-1 being significantly elevated at day 14 (P<0.05). By day 28, the venous stenosis was characterized by a thickened vein wall and neointima. Conclusions A mouse model of renal insufficiency with AVF was developed which had increased expression of HIF-1α, VEGF-A, VEGFR-1, VEGFR-2, MMP-2, TIMP-1, and ADAMTS-1 at the outflow vein with venous stenosis by day 28. PMID:20598569

Increased expression of HIF-1alpha, VEGF-A and its receptors, MMP-2, TIMP-1, and ADAMTS-1 at the venous stenosis of arteriovenous fistula in a mouse model with renal insufficiency.

Science.gov (United States)

Misra, Sanjay; Shergill, Uday; Yang, Binxia; Janardhanan, Rajiv; Misra, Khamal D

2010-08-01

A mouse model of renal insufficiency with arteriovenous fistula (AVF) and venous stenosis was created. The authors tested the hypothesis that there is increased gene expression of hypoxia-inducible factor-1 alpha (HIF-1alpha); vascular endothelial growth factor-A (VEGF-A) and its receptors (VEGFR-1, -2); matrix metalloproteinase-2 (MMP-2), -9 (MMP-9); tissue inhibitor of metalloproteinase-1, -2 (TIMP-1, -2); and a disintegrin and metalloproteinase thrombospondin-1 (ADAMTS-1) at the venous stenosis. Nineteen male C57BL/6 mice underwent a left nephrectomy and a surgical occlusion of the right upper pole to induce renal function characterized in eight animals. Twenty eight days later, an AVF (n = 11) was created from the right carotid artery to ipsilateral jugular vein, and the mice were killed at day 7 (n = 4) and day 14 (n = 4). The outflow and control veins were removed for gene expression. Three mice were killed at day 28 for histologic analysis. The mean serum blood urea nitrogen level remained significantly elevated for 8 weeks when compared with baseline (P < .05). By day seven, there was a significant increase in the expression of HIF-1alpha, VEGF-A, VEGFR-1, VEGFR-2, MMP-2, TIMP-1, and ADAMTS-1 at the outflow vein, with HIF-1alpha and TIMP-1 levels significantly elevated at day 14 (P < .05). By day 28, the venous stenosis was characterized by a thickened vein wall and neointima. A mouse model of renal insufficiency with AVF was developed that had increased expression of HIF-1alpha, VEGF-A, VEGFR-1, VEGFR-2, MMP-2, TIMP-1, and ADAMTS-1 at the outflow vein with venous stenosis by day 28. Copyright (c) 2010 SIR. Published by Elsevier Inc. All rights reserved.

Synthesis and preclinical evaluation of [11C]PAQ as a PET imaging tracer for VEGFR-2

International Nuclear Information System (INIS)

Samen, Erik; Stone-Elander, Sharon; Thorell, Jan-Olov; Lu, Li; Tegnebratt, Tetyana; Holmgren, Lars

2009-01-01

R,S-N-(4-Bromo-2-fluorophenyl)-6-methoxy-7-((1-methyl-3-piperidinyl)methox y)-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 11 C-labelled analogue as an in vivo tracer for VEGFR-2 expression in solid tumours. [ 11 C]PAQ was synthesized by an N-methylation of desmethyl-PAQ using [ 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). [ 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 [ 18 F]FDG and correlated well with variations in VEGFR-2 expression determined ex vivo by immunohistochemical analysis. These results suggest that [ 11 C]PAQ has potential as a noninvasive PET tracer for in vivo imaging of VEGFR-2 expression in angiogenic ''hot spots''. (orig.)

Synthesis and preclinical evaluation of [(11)C]PAQ as a PET imaging tracer for VEGFR-2.

Science.gov (United States)

Samén, Erik; Thorell, Jan-Olov; Lu, Li; Tegnebratt, Tetyana; Holmgren, Lars; Stone-Elander, Sharon

2009-08-01

(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 (11)C-labelled analogue as an in vivo tracer for VEGFR-2 expression in solid tumours. [(11)C]PAQ was synthesized by an N-methylation of desmethyl-PAQ using [(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). [(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 [(18)F]FDG and correlated well with variations in VEGFR-2 expression determined ex vivo by immunohistochemical analysis. These results suggest that [(11)C]PAQ has potential as a noninvasive PET tracer for in vivo imaging of VEGFR-2 expression in angiogenic "hot spots".

Gamabufotalin, a major derivative of bufadienolide, inhibits VEGF-induced angiogenesis by suppressing VEGFR-2 signaling pathway.

Science.gov (United States)

Tang, Ning; Shi, Lei; Yu, Zhenlong; Dong, Peipei; Wang, Chao; Huo, Xiaokui; Zhang, Baojing; Huang, Shanshan; Deng, Sa; Liu, Kexin; Ma, Tonghui; Wang, Xiaobo; Wu, Lijun; Ma, Xiao-Chi

2016-01-19

Gamabufotalin (CS-6), a main active compound isolated from Chinese medicine Chansu, has been shown to strongly inhibit cancer cell growth and inflammatory response. However, its effects on angiogenesis have not been known yet. Here, we sought to determine the biological effects of CS-6 on signaling mechanisms during angiogenesis. Our present results fully demonstrate that CS-6 could significantly inhibit VEGF triggered HUVECs proliferation, migration, invasion and tubulogenesis in vitro and blocked vascularization in Matrigel plugs impregnated in C57/BL6 mice as well as reduced vessel density in human lung tumor xenograft implanted in nude mice. Computer simulations revealed that CS-6 interacted with the ATP-binding sites of VEGFR-2 using molecular docking. Furthermore, western blot analysis indicated that CS-6 inhibited VEGF-induced phosphorylation of VEGFR-2 kinase and suppressed the activity of VEGFR-2-mediated signaling cascades. Therefore, our studies demonstrated that CS-6 inhibited angiogenesis by inhibiting the activation of VEGFR-2 signaling pathways and CS-6 could be a potential candidate in angiogenesis-related disease therapy.

Fascaplysin Exerts Anti-Cancer Effects through the Downregulation of Survivin and HIF-1α and Inhibition of VEGFR2 and TRKA

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Taek-In Oh

2017-09-01

Full Text Available Fascaplysin has been reported to exert anti-cancer effects by inhibiting cyclin-dependent kinase 4 (CDK4; however, the precise mode of action by which fascaplysin suppresses tumor growth is not clear. Here, we found that fascaplysin has stronger anti-cancer effects than other CDK4 inhibitors, including PD0332991 and LY2835219, on lung cancer cells that are wild-type or null for retinoblastoma (RB, indicating that unknown target molecules might be involved in the inhibition of tumor growth by fascaplysin. Fascaplysin treatment significantly decreased tumor angiogenesis and increased cleaved-caspase-3 in xenografted tumor tissues. In addition, survivin and HIF-1α were downregulated in vitro and in vivo by suppressing 4EBP1-p70S6K1 axis-mediated de novo protein synthesis. Kinase screening assays and drug-protein docking simulation studies demonstrated that fascaplysin strongly inhibited vascular endothelial growth factor receptor 2 (VEGFR2 and tropomyosin-related kinase A (TRKA via DFG-out non-competitive inhibition. Overall, these results suggest that fascaplysin inhibits TRKA and VEGFR2 and downregulates survivin and HIF-1α, resulting in suppression of tumor growth. Fascaplysin, therefore, represents a potential therapeutic approach for the treatment of multiple types of solid cancer.

Prognostic and predictive values of EGFR overexpression and EGFR copy number alteration in HER2-positive breast cancer.

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Lee, H J; Seo, A N; Kim, E J; Jang, M H; Kim, Y J; Kim, J H; Kim, S-W; Ryu, H S; Park, I A; Im, S-A; Gong, G; Jung, K H; Kim, H J; Park, S Y

2015-01-06

Epidermal growth factor receptor (EGFR) is overexpressed in a subset of human epidermal growth factor receptor 2 (HER2)-positive breast cancers, and coexpression of HER2 and EGFR has been reported to be associated with poor clinical outcome. Moreover, interaction between HER2 and EGFR has been suggested to be a possible basis for trastuzumab resistance. We analysed the clinical significance of EGFR overexpression and EGFR gene copy number alterations in 242 HER2-positive primary breast cancers. In addition, we examined the correlations between EGFR overexpression, trastuzumab response and clinical outcome in 447 primary, and 112 metastatic HER2-positive breast cancer patients treated by trastuzumab. Of the 242 primary cases, the level of EGFR overexpression was 2+ in 12.7% and 3+ in 11.8%. High EGFR gene copy number was detected in 10.3%. Epidermal growth factor receptor overexpression was associated with hormone receptor negativity and high Ki-67 proliferation index. In survival analyses, EGFR overexpression, but not high EGFR copy number, was associated with poor disease-free survival in all patients, and in the subgroup not receiving adjuvant trastuzumab. In 447 HER2-positive primary breast cancer patients treated with adjuvant trastuzumab, EGFR overexpression was also an independent poor prognostic factor. However, EGFR overexpression was not associated with trastuzumab response, progression-free survival or overall survival in the metastatic setting. Epidermal growth factor receptor overexpression, but not high EGFR copy number, is a poor prognostic factor in HER2-positive primary breast cancer. Epidermal growth factor receptor overexpression is a predictive factor for trastuzumab response in HER2-positive primary breast cancer, but not in metastatic breast cancer.

EGFR, HER-2 and KRAS in canine gastric epithelial tumors: a potential human model?

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Rossella Terragni

Full Text Available Epidermal growth factor receptor (EGFR or HER-1 and its analog c-erbB-2 (HER-2 are protein tyrosine kinases correlated with prognosis and response to therapy in a variety of human cancers. KRAS mediates the transduction of signals between EGFR and the nucleus, and its mutation has been identified as a predictor of resistance to anti-EGFR drugs. In human oncology, the importance of the EGFR/HER-2/KRAS signalling pathway in gastric cancer is well established, and HER-2 testing is required before initiating therapy. Conversely, this pathway has never been investigated in canine gastric tumours. A total of 19 canine gastric epithelial neoplasms (5 adenomas and 14 carcinomas were retrospectively evaluated for EGFR/HER-2 immunohistochemical expression and KRAS mutational status. Five (35.7% carcinomas were classified as intestinal-type and 9 (64.3% as diffuse-type. EGFR was overexpressed (≥ 1+ in 8 (42.1% cases and HER-2 (3+ in 11 (57.9% cases, regardless of tumour location or biological behaviour. The percentage of EGFR-positive tumours was significantly higher in the intestinal-type (80% than in the diffuse-type (11.1%, p = 0.023. KRAS gene was wild type in 18 cases, whereas one mucinous carcinoma harboured a point mutation at codon 12 (G12R. EGFR and HER-2 may be promising prognostic and therapeutic targets in canine gastric epithelial neoplasms. The potential presence of KRAS mutation should be taken into account as a possible mechanism of drug resistance. Further studies are necessary to evaluate the role of dog as a model for human gastric cancer.

EMMPRIN/CD147 is a novel coreceptor of VEGFR-2 mediating its activation by VEGF.

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Khayati, Farah; Pérez-Cano, Laura; Maouche, Kamel; Sadoux, Aurélie; Boutalbi, Zineb; Podgorniak, Marie-Pierre; Maskos, Uwe; Setterblad, Niclas; Janin, Anne; Calvo, Fabien; Lebbé, Céleste; Menashi, Suzanne; Fernandez-Recio, Juan; Mourah, Samia

2015-01-01

EMMPRIN/CD147 is mainly known for its protease inducing function but a role in promoting tumor angiogenesis has also been demonstrated. This study provides evidence that EMMPRIN is a new coreceptor for the VEGFR-2 tyrosine kinase receptor in both endothelial and tumor cells, as it directly interacts with it and regulates its activation by its VEGF ligand, signalling and functional consequences both in vitro and in vivo. Computational docking analyses and mutagenesis studies identified a molecular binding site in the extracellular domain of EMMPRIN located close to the cell membrane and containing the amino acids 195/199. EMMPRIN is overexpressed in cancer and hence is able to further potentiate VEGFR-2 activation, suggesting that a combinatory therapy of an antiangiogenic drug together with an inhibitor of EMMPRIN/VEGFR-2 interaction may have a greater impact on inhibiting angiogenesis and malignancy.

Construction and expression of an anti-VEGFR2 Nanobody-Fc fusionbody in NS0 host cell.

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Qasemi, Maryam; Behdani, Mahdi; Shokrgozar, Mohammad Ali; Molla-Kazemiha, Vahid; Mohseni-Kuchesfahani, Homa; Habibi-Anbouhi, Mahdi

2016-07-01

Angiogenesis is the formation of new blood vessels which is involved in migration, growth and differentiation of endothelial cells. This process regularly occurs during growth and development in children however, in adults is usually part of a disease process such as cancer. The vascular endothelial growth factor (VEGF) is a vital player in the vascular development and angiogenesis in physiological and pathological processes. Camelid's immune system has unique antibodies which are composed of only a heavy chain homodimer and the variable domain (VHH, Nanobody). Nanobodies are small, around 15 kDa and stable. In this study, we engineered and constructed a new Nanobody-Fc fusion protein (fusionbody) composed of an anti-VEGFR2 Nanobody and an Fc fragment of human IgG1 antibody. The recombinant vector was transfected into NS0 host cells. Stable producer clones were developed and the recombinant fusionbody was expressed and purified. Functional assay showed the anti-VEGFR2 fusionbody could bind to VEGFR2 on cell surface via VHH part and could mediate killing the targeted cells through direct cell death and complement-dependent cytotoxicity (CDC). Copyright © 2016 Elsevier Inc. All rights reserved.

Reduced estimated glomerular filtration rate (eGFR 73 m2 ) at first transurethral resection of bladder tumour is a significant predictor of subsequent recurrence and progression.

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Blute, Michael L; Kucherov, Victor; Rushmer, Timothy J; Damodaran, Shivashankar; Shi, Fangfang; Abel, E Jason; Jarrard, David F; Richards, Kyle A; Messing, Edward M; Downs, Tracy M

2017-09-01

To evaluate if moderate chronic kidney disease [CKD; estimated glomerular filtration rate (eGFR) 73 m 2 ] is associated with high rates of non-muscle-invasive bladder cancer (NMIBC) recurrence or progression. A multi-institutional database identified patients with serum creatinine values prior to first transurethral resection of bladder tumour (TURBT). The CKD-epidemiology collaboration formula calculated patient eGFR. Cox proportional hazards models evaluated associations with recurrence-free (RFS) and progression-free survival (PFS). In all, 727 patients were identified with a median (interquartile range [IQR]) patient age of 69.8 (60.1-77.6) years. Data for eGFR were available for 632 patients. During a median (IQR) follow-up of 3.7 (1.5-6.5) years, 400 (55%) patients had recurrence and 145 (19.9%) patients had progression of tumour stage or grade. Moderate or severe CKD was identified in 183 patients according to eGFR. Multivariable analysis identified an eGFR of 73 m 2 (hazard ratio [HR] 1.5, 95% confidence interval [CI]: 1.2-1.9; P = 0.002) as a predictor of tumour recurrence. The 5-year RFS rate was 46% for patients with an eGFR of ≥60 mL/min/1.73 m 2 and 27% for patients with an eGFR of 73 m 2 (P 73 m 2 (HR 3.7, 95% CI: 1.75-7.94; P = 0.001) was associated with progression to muscle-invasive disease. The 5-year PFS rate was 83% for patients with an eGFR of ≥60 mL/min/1.73 m 2 and 71% for patients with an eGFR of 73 m 2 (P = 0.01). Moderate CKD at first TURBT is associated with reduced RFS and PFS. Patients with reduced renal function should be considered for increased surveillance. © 2017 The Authors BJU International © 2017 BJU International Published by John Wiley & Sons Ltd.

On the nanotoxicity of PAMAM dendrimers: Superfect® stimulates the EGFR-ERK1/2 signal transduction pathway via an oxidative stress-dependent mechanism in HEK 293 cells.

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Akhtar, Saghir; Chandrasekhar, Bindu; Attur, Sreeja; Yousif, Mariam H M; Benter, Ibrahim F

2013-05-01

Polyamidoamine (PAMAM) dendrimers are cationic branch-like macromolecules that may serve as drug delivery systems for gene-based therapies such as RNA interference. For their safe use in the clinic, they should ideally only enhance drug delivery to target tissues and exhibit no adverse effects. However, little is known about their toxicological profiles in terms of their interactions with cellular signal transduction pathways such as the epidermal growth factor receptor (EGFR). The EGFR is an important signaling cascade that regulates cell growth, differentiation, migration, survival and apoptosis. Here, we investigated the impact of naked, unmodified Superfect (SF), a commercially available generation 6 PAMAM dendrimer, on the epidermal growth factor receptor (EGFR) tyrosine kinase-extracellular-regulated kinase 1/2 (ERK1/2) signaling pathway in human embryonic kidney (HEK 293) cells. At concentrations routinely used for transfection, SF exhibited time and dose-dependent stimulation of EGFR and ERK1/2 phosphorylation whereas AG1478, a selective EGFR tyrosine kinase antagonist, inhibited EGFR-ERK1/2 signaling. SF-induced phosphorylation of EGFR for 1h was partly reversible upon removal of the dendrimer and examination of cells 24 later. Co-treatment of SF with epidermal growth factor (EGF) ligand resulted in greater EGFR stimulation than either agent alone implying that the stimulatory effects of SF and the ligand are synergistic. Dendrimer-induced stimulation of EGFR-ERK1/2 signaling could be attenuated by the antioxidants apocynin, catalase and tempol implying that an oxidative stress dependent mechanism was involved. These results show for the first time that PAMAM dendrimers, aside from their ability to improve drug delivery, can modulate the important EGFR-ERK1/2 cellular signal transduction pathway - a novel finding that may have a bearing on their safe application as drug delivery systems. Copyright © 2013 Elsevier B.V. All rights reserved.

Phase I study of cetuximab, irinotecan, and vandetanib (ZD6474 as therapy for patients with previously treated metastastic colorectal cancer.

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Jeffrey A Meyerhardt

Full Text Available BACKGROUND: To determine the maximum tolerated dose (MTD and safety, and explore efficacy and biomarkers of vandetanib with cetuximab and irinotecan in second-line metastatic colorectal cancer. METHODS: Vandetanib (an orally bioavailable VEGFR-2 and EGFR tyrosine kinases inhibitor was combined at 100 mg, 200 mg, or 300 mg daily with standard dosed cetuximab and irinotecan (3+3 dose-escalation design. Ten patients were treated at the MTD and plasma angiogenesis biomarkers (VEGF, PlGF, bFGF, sVEGFR1, sVEGFR2, IL-1β, IL-6, IL-8, TNF-α, SDF1α were measured before and after treatment. RESULTS: Twenty-seven patients were enrolled at 4 dose levels and the MTD. Two dose-limiting toxicities (grade 3 QTc prolongation and diarrhea were detected at 300 mg of vandetanib with cetuximab and irinotecan resulting in 200 mg being the MTD. Seven percent of patients had a partial response, 59% stable disease and 34% progressed. Median progression-free survival was 3.6 months (95% CI, 3.2-5.6 and median overall survival was 10.5 months (95% CI, 5.1-20.7. Toxicities were fairly manageable with grade 3 or 4 diarrhea being most prominent (30%. Vandetanib and cetuximab treatment induced a sustained increase in plasma PlGF and a transient decrease in plasma sVEGFR1, but no changes in plasma VEGF and sVEGFR2. CONCLUSIONS: Vandetanib can be safely combined with cetuximab and irinotecan for metastatic colorectal cancer. Exploratory biomarker analyses suggest differential effects on certain plasma biomarkers for VEGFR inhibition when combined with EGFR blockade and a potential correlation between baseline sVEGFR1 and response. However, while the primary endpoint was safety, the observed efficacy raises concern for moving forward with this combination. TRIAL REGISTRATION: Clinicaltrials.gov NCT00436072.

Performance of scintillation proximity assay (SPA) to measure the level of VEGFR 1 protein

International Nuclear Information System (INIS)

LEE, So-Young; LIM, Jae-Cheong; KIM, Jin-Joo

2014-01-01

Scintillation proximity assay is a one of radioimmunoassay and can be assayed without the washing or filtration procedures normally used to separate bound from free fractions. Due to its simplicity and high-throughput protocol, it is broadly applicable to immunology, receptor binding, monitoring receptor-ligand interactions and enzyme reactions. Briefly, an antibody or receptor is coated on SPA beads. When a radiolabeled antigen or ligand binds to the beads, the SPA beads stimulate to emit short range electrons. The 3 H and 125 I are commonly used for radiolabeling and the produced photons are detectable with a liquid scintillation counter (LSC). A binding affinity of unlabeled ligands can be determined by competitive reaction of the radiolabeled ligands. Bevacizumab is a recombinant humanized monoclonal antibody, and can stop or delay growth of tumors by inhibiting vascular endothelial growth factor (VEGF). Bevacizumab was approved by FDA for metastatic cancer such as colorectal cancers, ovarian cancers, breast cancers and glioblastoma multiform of the brain. Recently, Dan G. duda et al. was reported that the concentration of vascular endothelial growth factor receptor-1 (VEGFR-1) in plasma may potentially be used as a negative selection biomarker. In this study, we describe a method using scintillation proximity assay to detect the amounts of VEGFR-1 protein. This method is successfully used to measure the concentration of VEGFR-1 protein in human cell extracts. In summary, a simple and sensitive assay is developed for measuring the amount of VEGFR 1 protein in cancer cell lysate using SPA beads. The antibody coating on the beads and antigen binding are achieved in one mixing step

Performance of scintillation proximity assay (SPA) to measure the level of VEGFR 1 protein

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LEE, So-Young; LIM, Jae-Cheong; KIM, Jin-Joo [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2014-10-15

Scintillation proximity assay is a one of radioimmunoassay and can be assayed without the washing or filtration procedures normally used to separate bound from free fractions. Due to its simplicity and high-throughput protocol, it is broadly applicable to immunology, receptor binding, monitoring receptor-ligand interactions and enzyme reactions. Briefly, an antibody or receptor is coated on SPA beads. When a radiolabeled antigen or ligand binds to the beads, the SPA beads stimulate to emit short range electrons. The {sup 3}H and {sup 125}I are commonly used for radiolabeling and the produced photons are detectable with a liquid scintillation counter (LSC). A binding affinity of unlabeled ligands can be determined by competitive reaction of the radiolabeled ligands. Bevacizumab is a recombinant humanized monoclonal antibody, and can stop or delay growth of tumors by inhibiting vascular endothelial growth factor (VEGF). Bevacizumab was approved by FDA for metastatic cancer such as colorectal cancers, ovarian cancers, breast cancers and glioblastoma multiform of the brain. Recently, Dan G. duda et al. was reported that the concentration of vascular endothelial growth factor receptor-1 (VEGFR-1) in plasma may potentially be used as a negative selection biomarker. In this study, we describe a method using scintillation proximity assay to detect the amounts of VEGFR-1 protein. This method is successfully used to measure the concentration of VEGFR-1 protein in human cell extracts. In summary, a simple and sensitive assay is developed for measuring the amount of VEGFR 1 protein in cancer cell lysate using SPA beads. The antibody coating on the beads and antigen binding are achieved in one mixing step.

Kaempferol Inhibits Angiogenesis by Suppressing HIF-1α and VEGFR2 Activation via ERK/p38 MAPK and PI3K/Akt/mTOR Signaling Pathways in Endothelial Cells.

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Kim, Gi Dae

2017-12-01

Kaempferol has been shown to inhibit vascular formation in endothelial cells. However, the underlying mechanisms are not fully understood. In the present study, we evaluated whether kaempferol exerts antiangiogenic effects by targeting extracellular signal-regulated kinase (ERK)/p38 mitogen-activated protein kinase (MAPK) and phosphoinositide 3-kinase (PI3K)/Akt/mechanistic target of rapamycin (mTOR) signaling pathways in endothelial cells. Endothelial cells were treated with various concentrations of kaempferol for 24 h. Cell viability was determined by the 3- (4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide assay; vascular formation was analyzed by tube formation, wound healing, and mouse aortic ring assays. Activation of hypoxia-inducible factor-1α (HIF-1α), vascular endothelial growth factor receptor 2 (VEGFR2), ERK/p38 MAPK, and PI3K/Akt/mTOR was analyzed by Western blotting. Kaempferol significantly inhibited cell migration and tube formation in endothelial cells, and suppressed microvessel sprouting in the mouse aortic ring assay. Moreover, kaempferol suppressed the activation of HIF-1α, VEGFR2, and other markers of ERK/p38 MAPK and PI3K/Akt/mTOR signaling pathways in endothelial cells. These results suggest that kaempferol inhibits angiogenesis by suppressing HIF-1α and VEGFR2 activation via ERK/p38 MAPK and PI3K/Akt/mTOR signaling in endothelial cells.

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

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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.

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

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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.

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

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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.)

Metabolic and molecular relative percentage coreduction in patients with locally advanced rectal cancer treated with neoadjuvant therapy

International Nuclear Information System (INIS)

Sole, Claudio V.; Calvo, Felipe A.; Alvarez, Emilio; Carreras, Jose L.

2016-01-01

Vascular endothelial growth factor receptor-2 (VEGFR-2), epidermal growth factor receptor-1 (EGFR) and cyclooxygenase-2 (COX-2) stimulate key processes involved in tumour progression and are important targets for cancer therapeutics. 18 F-FDG maximum standardized uptake value (SUVmax) on PET/CT is a marker of tumour metabolic activity. The purpose of this study was to measure percentage reductions in SUVmax (∇SUVmax%), VEGFR-2 (∇VEGFR-2%), EGFR (∇EGFR%) and COX-2 (∇COX-2%) in patients with locally advanced rectal cancer (LARC) after preoperative treatment, and to correlate the changes in these markers of response with pathological response in terms of tumour regression grade (TRG) using Roedel's scale and long-term clinical outcome. VEGFR-2, EGFR and COX-2 were measured using a quantitative and qualitative compound immunohistochemistry analysis (immunoreactive score) of the pretreatment endoscopic biopsy and definitive surgical specimens. Composite indexes using ∇SUVmax% and the three molecules were developed to differentiate patients with metabolic and molecular responses from nonresponders. Cox proportional hazards model was used to explore associations between the tumour markers, disease-free survival (DFS) and overall survival (OS). The analysis included 38 patients with a median follow-up of 86 months (range 5 - 113 months). The ∇VEGFR-2%/∇SUVmax% index correctly identified 13 of 19 pathological responders (TRG 3 and 4) and 17 of 19 nonresponders (TRG 0 - 2) (sensitivity 68 %, specificity 89 %, accuracy 79 %, positive predictive value 87 %, negative predictive value 74 %). In multivariate analysis, only the ∇VEGFR-2%/∇SUVmax% index was associated with DFS (HR 0.11, p = 0.001) and OS (HR 0.15, p = 0.02). In patients with LARC the ∇VEGFR-2%/∇SUVmax% response index is associated with outcome. Determination of the optimal diagnostic cut-off level for this novel biomarker association should be explored. Evaluation in a clinical trial is

Acidic pH reduces VEGF-mediated endothelial cell responses by downregulation of VEGFR-2; relevance for anti-angiogenic therapies.

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Faes, Seraina; Uldry, Emilie; Planche, Anne; Santoro, Tania; Pythoud, Catherine; Demartines, Nicolas; Dormond, Olivier

2016-12-27

Anti-angiogenic treatments targeting the vascular endothelial growth factor or its receptors have shown clinical benefits. However, impact on long-term survival remains limited. Solid tumors display an acidic microenvironment that profoundly influences their biology. Consequences of acidity on endothelial cells and anti-angiogenic therapies remain poorly characterized and hence are the focus of this study. We found that exposing endothelial cells to acidic extracellular pH resulted in reduced cell proliferation and migration. Also, whereas VEGF increased endothelial cell proliferation and survival at pH 7.4, it had no effect at pH 6.4. Furthermore, in acidic conditions, stimulation of endothelial cells with VEGF did not result in activation of downstream signaling pathways such as AKT. At a molecular level, acidity significantly decreased the expression of VEGFR-2 by endothelial cells. Consequently, anti-angiogenic therapies that target VEGFR-2 such as sunitinib and sorafenib failed to block endothelial cell proliferation in acidic conditions. In vivo, neutralizing tumor acidity with sodium bicarbonate increased the percentage of endothelial cells expressing VEGFR-2 in tumor xenografts. Furthermore, combining sodium bicarbonate with sunitinib provided stronger anti-cancer activity than either treatment alone. Histological analysis showed that sunitinib had a stronger anti-angiogenic effect when combined with sodium bicarbonate. Overall, our results show that endothelial cells prosper independently of VEGF in acidic conditions partly as a consequence of decreased VEGFR-2 expression. They further suggest that strategies aiming to raise intratumoral pH can improve the efficacy of anti-VEGF treatments.

Design, synthesis, and evaluation of VEGFR-targeted macromolecular MRI contrast agent based on biotin–avidin-specific binding

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Liu YJ

2017-07-01

Full Text Available Yongjun Liu,1 Xiaoyun Wu,1 Xiaohe Sun,1 Dan Wang,1 Ying Zhong,1 Dandan Jiang,1 Tianqi Wang,1 Dexin Yu,2 Na Zhang1 1School of Pharmaceutical Science, Shandong University, 2Department of Radiology Medicine, Qilu Hospital, Jinan, People’s Republic of China Abstract: Developing magnetic resonance imaging (MRI contrast agents with high relaxivity and specificity was essential to increase MRI diagnostic sensitivity and accuracy. In this study, the MRI contrast agent, vascular endothelial growth factor receptor (VEGFR-targeted poly (l-lysine (PLL-diethylene triamine pentacetate acid (DTPA-gadolinium (Gd (VEGFR-targeted PLL-DTPA-Gd, VPDG, was designed and prepared to enhance the MRI diagnosis capacity of tumor. Biotin-PLL-DTPA-Gd was synthesized first, then, VEGFR antibody was linked to biotin-PLL-DTPA-Gd using biotin–avidin reaction. In vitro cytotoxicity study results showed that VPDG had low toxicity to MCF-7 cells and HepG2 cells at experimental concentrations. In cell uptake experiments, VPDG could significantly increase the internalization rates (61.75%±5.22% in VEGFR-positive HepG2 cells compared to PLL-DTPA-Gd (PDG (25.16%±4.71%, P<0.05. In MRI studies in vitro, significantly higher T1 relaxivity (14.184 mM-1 s-1 was observed compared to Magnevist® (4.9 mM-1 s-1; P<0.01. Furthermore, in vivo MRI study results showed that VPDG could significantly enhance the tumor signal intensity and prolong the diagnostic time (from <1 h to 2.5 h. These results indicated that macromolecular VPDG was a promising MRI contrast agent and held great potential for molecular diagnosis of tumor. Keywords: MRI, contrast agent, VEGFR, biotin–avidin reaction, relaxivity

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.

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

International Nuclear Information System (INIS)

Luan, Xin; Gao, Yun-Ge; Guan, Ying-Yun; Xu, Jian-Rong; Lu, Qin; Zhao, Mei; Liu, Ya-Rong; Liu, Hai-Jun; Fang, Chao; Chen, Hong-Zhuan

2014-01-01

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

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

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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.

VEGFR-3 signaling is regulated by a G-protein activator, activator of G-protein signaling 8, in lymphatic endothelial cells.

Science.gov (United States)

Sakima, Miho; Hayashi, Hisaki; Mamun, Abdullah Al; Sato, Motohiko

2018-07-01

Vascular endothelial growth factor C (VEGFC) and its cognate receptor VEGFR-3 play a key role in lymphangiogenesis. We previously reported that an ischemia-inducible Gβγ signal regulator, activator of G-protein signaling 8 (AGS8), regulated the subcellular distribution of vascular endothelial growth factor receptor-2 (VEGFR-2) and influenced VEGFA-induced signaling in vascular endothelial cells. Here, we report that AGS8 regulates VEGFR-3, which is another subtype of the VEGF receptor family, and mediates VEGFC signaling in human dermal lymphatic endothelial cells (HDLECs). VEGFC stimulated the proliferation of HDLECs and tube formation by HDLECs, which were inhibited by knocking down AGS8 by small interfering RNA (siRNA). AGS8 siRNA inhibited VEGFC-mediated phosphorylation of VEGFR-3 and its downstream molecules, including ERK1/2 and AKT. Analysis of fluorescence-activated cell sorting and immunofluorescence staining demonstrated that AGS8 knockdown was associated with a reduction of VEGFR-3 at the cell surface. Endocytosis inhibitors did not rescue the decrease of cell-surface VEGFR-3, suggesting that AGS8 regulated the trafficking of VEGFR-3 to the plasma membrane. An immunoprecipitation assay indicated that VEGFR-3 formed a complex including AGS8 and Gβγ in cells. These data suggest the novel regulation of VEGFC-VEGFR-3 by AGS8 in HDLECs and a potential role for AGS8 in lymphangiogenesis. Copyright © 2018 Elsevier Inc. All rights reserved.

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.

Nilotinib Enhances Tumor Angiogenesis and Counteracts VEGFR2 Blockade in an Orthotopic Breast Cancer Xenograft Model with Desmoplastic Response

Directory of Open Access Journals (Sweden)

Sara Zafarnia

2017-11-01

Full Text Available Vascular endothelial growth factor (VEGF/VEGF receptor (VEGFR-targeted therapies predominantly affect nascent, immature tumor vessels. Since platelet-derived growth factor receptor (PDGFR blockade inhibits vessel maturation and thus increases the amount of immature tumor vessels, we evaluated whether the combined PDGFR inhibition by nilotinib and VEGFR2 blockade by DC101 has synergistic therapy effects in a desmoplastic breast cancer xenograft model. In this context, besides immunohistological evaluation, molecular ultrasound imaging with BR55, the clinically used VEGFR2-targeted microbubbles, was applied to monitor VEGFR2-positive vessels noninvasively and to assess the therapy effects on tumor angiogenesis. DC101 treatment alone inhibited tumor angiogenesis, resulting in lower tumor growth and in significantly lower vessel density than in the control group after 14 days of therapy. In contrast, nilotinib inhibited vessel maturation but enhanced VEGFR2 expression, leading to markedly increased tumor volumes and a significantly higher vessel density. The combination of both drugs led to an almost similar tumor growth as in the DC101 treatment group, but VEGFR2 expression and microvessel density were higher and comparable to the controls. Further analyses revealed significantly higher levels of tumor cell–derived VEGF in nilotinib-treated tumors. In line with this, nilotinib, especially in low doses, induced an upregulation of VEGF and IL-6 mRNA in the tumor cells in vitro, thus providing an explanation for the enhanced angiogenesis observed in nilotinib-treated tumors in vivo. These findings suggest that nilotinib inhibits vessel maturation but counteracts the effects of antiangiogenic co-therapy by enhancing VEGF expression by the tumor cells and stimulating tumor angiogenesis.

Design, synthesis, and evaluation of VEGFR-targeted macromolecular MRI contrast agent based on biotin–avidin-specific binding

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Liu, Yongjun; Wu, Xiaoyun; Sun, Xiaohe; Wang, Dan; Zhong, Ying; Jiang, Dandan; Wang, Tianqi; Yu, Dexin; Zhang, Na

2017-01-01

Developing magnetic resonance imaging (MRI) contrast agents with high relaxivity and specificity was essential to increase MRI diagnostic sensitivity and accuracy. In this study, the MRI contrast agent, vascular endothelial growth factor receptor (VEGFR)-targeted poly (l-lysine) (PLL)-diethylene triamine pentacetate acid (DTPA)-gadolinium (Gd) (VEGFR-targeted PLL-DTPA-Gd, VPDG), was designed and prepared to enhance the MRI diagnosis capacity of tumor. Biotin-PLL-DTPA-Gd was synthesized first, then, VEGFR antibody was linked to biotin-PLL-DTPA-Gd using biotin–avidin reaction. In vitro cytotoxicity study results showed that VPDG had low toxicity to MCF-7 cells and HepG2 cells at experimental concentrations. In cell uptake experiments, VPDG could significantly increase the internalization rates (61.75%±5.22%) in VEGFR-positive HepG2 cells compared to PLL-DTPA-Gd (PDG) (25.16%±4.71%, P<0.05). In MRI studies in vitro, significantly higher T1 relaxivity (14.184 mM−1 s−1) was observed compared to Magnevist® (4.9 mM−1 s−1; P<0.01). Furthermore, in vivo MRI study results showed that VPDG could significantly enhance the tumor signal intensity and prolong the diagnostic time (from <1 h to 2.5 h). These results indicated that macromolecular VPDG was a promising MRI contrast agent and held great potential for molecular diagnosis of tumor. PMID:28765707

Icotinib in Patients with Pretreated Advanced Esophageal Squamous Cell Carcinoma with EGFR Overexpression or EGFR Gene Amplification: A Single-Arm, Multicenter Phase 2 Study.

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Huang, Jing; Fan, Qingxia; Lu, Ping; Ying, Jianming; Ma, Changwu; Liu, Wei; Liu, Ying; Tan, Fenlai; Sun, Yan

2016-06-01

Epidermal growth factor receptor (EGFR) has been reported to be overexpressed and amplified in a high percentage of patients with esophageal squamous cell carcinoma (ESCC). The activity of icotinib, an EGFR tyrosine kinase inhibitor, was assessed in previously treated ESCC with EGFR overexpression or amplification. For this phase 2, single-arm, multicenter trial undertaken at six hospitals in China, we included Chinese patients with previously treated, histologically confirmed advanced ESCC and EGFR overexpression (immunohistochemical staining sore of 3+) or amplification (positive fluorescence in situ hybridization result). These patients received oral icotinib (250 mg, three times daily).The primary end point was the proportion of patients with objective responses as assessed by an independent radiology review committee. Between December 5, 2013, and May 28, 2015, a total of 281 patients were screened. Fifty-four eligible patients were enrolled. Nine responses were observed, including one complete response and eight partial responses, and 16 patients had stable disease, resulting in a 16.7% objective response rate (95% confidence interval [CI]: 6.7-26.6) and 46.3% disease control rate (95% CI: 33.0-59.6). The median progression-free survival and overall survival times were 52 (95% CI: 40-95) days and 153 (95% CI: 139-218) days, respectively. A total of 43 patients experienced at least one adverse event, but most were only grade 1 to 2 in severity. The most frequent was rash (48.1%), followed by diarrhea (22.2%). Icotinib showed favorable activity in patients with advanced, previously treated ESCC with EGFR overexpression or amplification. These findings suggest further research into EGFR overexpression or amplification for selecting responsive patients. Copyright © 2016 International Association for the Study of Lung Cancer. Published by Elsevier Inc. All rights reserved.

Ccbe1 regulates Vegfc-mediated induction of Vegfr3 signaling during embryonic lymphangiogenesis

NARCIS (Netherlands)

Le Guen, Ludovic; Karpanen, Terhi; Schulte, Dörte; Harris, Nicole C; Koltowska, Katarzyna; Roukens, Guy; Bower, Neil I; van Impel, Andreas; Stacker, Steven A; Achen, Marc G; Schulte-Merker, Stefan; Hogan, Benjamin M

The VEGFC/VEGFR3 signaling pathway is essential for lymphangiogenesis (the formation of lymphatic vessels from pre-existing vasculature) during embryonic development, tissue regeneration and tumor progression. The recently identified secreted protein CCBE1 is indispensible for lymphangiogenesis

Identifying EGFR-Expressed Cells and Detecting EGFR Multi-Mutations at Single-Cell Level by Microfluidic Chip

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Li, Ren; Zhou, Mingxing; Li, Jine; Wang, Zihua; Zhang, Weikai; Yue, Chunyan; Ma, Yan; Peng, Hailin; Wei, Zewen; Hu, Zhiyuan

2018-03-01

EGFR mutations companion diagnostics have been proved to be crucial for the efficacy of tyrosine kinase inhibitor targeted cancer therapies. To uncover multiple mutations occurred in minority of EGFR-mutated cells, which may be covered by the noises from majority of un-mutated cells, is currently becoming an urgent clinical requirement. Here we present the validation of a microfluidic-chip-based method for detecting EGFR multi-mutations at single-cell level. By trapping and immunofluorescently imaging single cells in specifically designed silicon microwells, the EGFR-expressed cells were easily identified. By in situ lysing single cells, the cell lysates of EGFR-expressed cells were retrieved without cross-contamination. Benefited from excluding the noise from cells without EGFR expression, the simple and cost-effective Sanger's sequencing, but not the expensive deep sequencing of the whole cell population, was used to discover multi-mutations. We verified the new method with precisely discovering three most important EGFR drug-related mutations from a sample in which EGFR-mutated cells only account for a small percentage of whole cell population. The microfluidic chip is capable of discovering not only the existence of specific EGFR multi-mutations, but also other valuable single-cell-level information: on which specific cells the mutations occurred, or whether different mutations coexist on the same cells. This microfluidic chip constitutes a promising method to promote simple and cost-effective Sanger's sequencing to be a routine test before performing targeted cancer therapy.[Figure not available: see fulltext.

Celecoxib induces proliferation and Amphiregulin production in colon subepithelial myofibroblasts, activating erk1-2 signaling in synergy with EGFR.

Science.gov (United States)

Benelli, Roberto; Venè, Roberta; Minghelli, Simona; Carlone, Sebastiano; Gatteschi, Beatrice; Ferrari, Nicoletta

2013-01-01

The COX-2 inhibitor Celecoxib, tested in phase III trials for the prevention of sporadic colon adenomas, reduced the appearance of new adenomas, but was unable to affect the incidence of colon cancer. Moreover the 5years follow-up showed that patients discontinuing Celecoxib treatment had an increased incidence of adenomas as compared to the placebo arm. In the APC(min/+) mouse model short term treatment with Celecoxib reduced gut adenomas, but a prolonged administration of the drug induced fibroblast activation and intestinal fibrosis with a final tumor burden. The way Celecoxib could directly activate human colon myofibroblasts (MF) has not yet been investigated. We found that MF are activated by non toxic doses of Celecoxib. Celecoxib induces erk1-2 and Akt phosphorylation within 5'. This short term activation is apparently insufficient to cause phenotypic changes, but the contemporary triggering of EGFR causes an impressive synergic effect inducing MF proliferation and the neo-expression and release of Amphiregulin (AREG), a well known EGFR agonist involved in colon cancer progression. As a confirm to these observations, the erk inhibitor U0126 and the EGFR inhibitors Tyrphostin and Cetuximab were able to contrast AREG induction. Our data provide evidence that Celecoxib directly activates MF empowering EGFR signaling. According to these results the association with EGFR (or erk1-2) inhibitors could abolish the off-target activity of Celecoxib, possibly extending the potential of this drug for colon cancer prevention. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Anterior Gradient 2 (AGR2) Induced Epidermal Growth Factor Receptor (EGFR) Signaling Is Essential for Murine Pancreatitis-Associated Tissue Regeneration

Science.gov (United States)

Wodziak, Dariusz; Dong, Aiwen; Basin, Michael F.; Lowe, Anson W.

2016-01-01

A recently published study identified Anterior Gradient 2 (AGR2) as a regulator of EGFR signaling by promoting receptor presentation from the endoplasmic reticulum to the cell surface. AGR2 also promotes tissue regeneration in amphibians and fish. Whether AGR2-induced EGFR signaling is essential for tissue regeneration in higher vertebrates was evaluated using a well-characterized murine model for pancreatitis. The impact of AGR2 expression and EGFR signaling on tissue regeneration was evaluated using the caerulein-induced pancreatitis mouse model. EGFR signaling and cell proliferation were examined in the context of the AGR2-/- null mouse or with the EGFR-specific tyrosine kinase inhibitor, AG1478. In addition, the Hippo signaling coactivator YAP1 was evaluated in the context of AGR2 expression during pancreatitis. Pancreatitis-induced AGR2 expression enabled EGFR translocation to the plasma membrane, the initiation of cell signaling, and cell proliferation. EGFR signaling and tissue regeneration were partially inhibited by the tyrosine kinase inhibitor AG1478, but absent in the AGR2-/- null mouse. AG1478-treated and AGR2-/- null mice with pancreatitis died whereas all wild-type controls recovered. YAP1 activation was also dependent on pancreatitis-induced AGR2 expression. AGR2-induced EGFR signaling was essential for tissue regeneration and recovery from pancreatitis. The results establish tissue regeneration as a major function of AGR2-induced EGFR signaling in adult higher vertebrates. Enhanced AGR2 expression and EGFR signaling are also universally present in human pancreatic cancer, which support a linkage between tissue injury, regeneration, and cancer pathogenesis. PMID:27764193

Aliphatic acetogenin constituents of avocado fruits inhibit human oral cancer cell proliferation by targeting the EGFR/RAS/RAF/MEK/ERK1/2 pathway

Energy Technology Data Exchange (ETDEWEB)

D' Ambrosio, Steven M. [Department of Radiology, College of Medicine, The Ohio State University, Columbus, OH 43210 (United States); Comprehensive Cancer Center, The Ohio State University, Columbus, OH 43210 (United States); Han, Chunhua [Department of Radiology, College of Medicine, The Ohio State University, Columbus, OH 43210 (United States); Pan, Li; Douglas Kinghorn, A. [Division of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, The Ohio State University, Columbus, OH 43210 (United States); Ding, Haiming, E-mail: ding.29@osu.edu [Department of Radiology, College of Medicine, The Ohio State University, Columbus, OH 43210 (United States)

2011-06-10

Highlights: {yields} The aliphatic acetogenins [(2S,4S)-2,4-dihydroxyheptadec-16-enyl acetate] (1) and [(2S,4S)-2,4-dihydroxyheptadec-16-ynyl acetate] (2) isolated from avocado fruit inhibit phosphorylation of c-RAF (Ser338) and ERK1/2 (Thr202/Tyr204). {yields} Aliphatic acetogenin 2, but not 1, prevents EGF-induced activation of EGFR (Tyr1173). {yields} Combination of both aliphatic acetogenins synergistically inhibits c-RAF (Ser338) and ERK1/2 (Thr202/Tyr204) phosphorylation and human oral cancer cell proliferation. {yields} The potential anticancer activity of avocado fruits is due to a combination of specific aliphatic acetogenins targeting two key components of the EGFR/RAS/RAF/MEK/ERK1/2 cancer pathway. {yields} Providing a double hit on a critical cancer pathway such as EGFR/RAS/RAF/MEK/ERK1/2 by phytochemicals like those found in avocado fruit could lead to more effective approach toward cancer prevention. -- Abstract: Avocado (Persea americana) fruits are consumed as part of the human diet and extracts have shown growth inhibitory effects in various types of human cancer cells, although the effectiveness of individual components and their underlying mechanism are poorly understood. Using activity-guided fractionation of the flesh of avocado fruits, a chloroform-soluble extract (D003) was identified that exhibited high efficacy towards premalignant and malignant human oral cancer cell lines. From this extract, two aliphatic acetogenins of previously known structure were isolated, compounds 1 [(2S,4S)-2,4-dihydroxyheptadec-16-enyl acetate] and 2 [(2S,4S)-2,4-dihydroxyheptadec-16-ynyl acetate]. In this study, we show for the first time that the growth inhibitory efficacy of this chloroform extract is due to blocking the phosphorylation of EGFR (Tyr1173), c-RAF (Ser338), and ERK1/2 (Thr202/Tyr204) in the EGFR/RAS/RAF/MEK/ERK1/2 cancer pathway. Compounds 1 and 2 both inhibited phosphorylation of c-RAF (Ser338) and ERK1/2 (Thr202/Tyr204). Compound 2, but not

Aliphatic acetogenin constituents of avocado fruits inhibit human oral cancer cell proliferation by targeting the EGFR/RAS/RAF/MEK/ERK1/2 pathway

International Nuclear Information System (INIS)

D'Ambrosio, Steven M.; Han, Chunhua; Pan, Li; Douglas Kinghorn, A.; Ding, Haiming

2011-01-01

Highlights: → The aliphatic acetogenins [(2S,4S)-2,4-dihydroxyheptadec-16-enyl acetate] (1) and [(2S,4S)-2,4-dihydroxyheptadec-16-ynyl acetate] (2) isolated from avocado fruit inhibit phosphorylation of c-RAF (Ser338) and ERK1/2 (Thr202/Tyr204). → Aliphatic acetogenin 2, but not 1, prevents EGF-induced activation of EGFR (Tyr1173). → Combination of both aliphatic acetogenins synergistically inhibits c-RAF (Ser338) and ERK1/2 (Thr202/Tyr204) phosphorylation and human oral cancer cell proliferation. → The potential anticancer activity of avocado fruits is due to a combination of specific aliphatic acetogenins targeting two key components of the EGFR/RAS/RAF/MEK/ERK1/2 cancer pathway. → Providing a double hit on a critical cancer pathway such as EGFR/RAS/RAF/MEK/ERK1/2 by phytochemicals like those found in avocado fruit could lead to more effective approach toward cancer prevention. -- Abstract: Avocado (Persea americana) fruits are consumed as part of the human diet and extracts have shown growth inhibitory effects in various types of human cancer cells, although the effectiveness of individual components and their underlying mechanism are poorly understood. Using activity-guided fractionation of the flesh of avocado fruits, a chloroform-soluble extract (D003) was identified that exhibited high efficacy towards premalignant and malignant human oral cancer cell lines. From this extract, two aliphatic acetogenins of previously known structure were isolated, compounds 1 [(2S,4S)-2,4-dihydroxyheptadec-16-enyl acetate] and 2 [(2S,4S)-2,4-dihydroxyheptadec-16-ynyl acetate]. In this study, we show for the first time that the growth inhibitory efficacy of this chloroform extract is due to blocking the phosphorylation of EGFR (Tyr1173), c-RAF (Ser338), and ERK1/2 (Thr202/Tyr204) in the EGFR/RAS/RAF/MEK/ERK1/2 cancer pathway. Compounds 1 and 2 both inhibited phosphorylation of c-RAF (Ser338) and ERK1/2 (Thr202/Tyr204). Compound 2, but not compound 1, prevented EGF

MLH1 V384D polymorphism associates with poor response to EGFR tyrosine kinase inhibitors in patients with EGFR L858R-positive lung adenocarcinoma.

Science.gov (United States)

Chiu, Chao-Hua; Ho, Hsiang-Ling; Doong, Howard; Yeh, Yi-Chen; Chen, Mei-Yu; Chou, Teh-Ying; Tsai, Chun-Ming

2015-04-10

A significant fraction of patients with lung adenocarcinomas harboring activating epidermal growth factor receptor (EGFR) mutations do not experience clinical benefits from EGFR tyrosine kinase inhibitor (TKI) therapy. Using next-generation sequencing, we screened 739 mutation hotspots in 46 cancer-related genes in EGFR L858R-mutant lung adenocarcinomas from 29 patients who received EGFR-TKI therapy; 13 had short ( 1 year) progression-free survival (PFS). We discovered MLH1 V384D as a genetic variant enriched in the group of patients with short PFS. Next, we investigated this genetic variation in 158 lung adenocarcinomas with the EGFR L858R mutation and found 14 (8.9%) patients had MLH1 V384D; available blood or non-tumor tissues from patients were also tested positive for MLH1 V384D. Patients with MLH1 V384D had a significantly shorter median PFS than those without (5.1 vs. 10.6 months; P= 0.001). Multivariate analysis showed that MLH1 V384D polymorphism was an independent predictor for a reduced PFS time (hazard ratio, 3.5; 95% confidence interval, 1.7 to 7.2; P= 0.001). In conclusion, MLH1 V384D polymorphism is associated with primary resistance to EGFR-TKIs in patients with EGFR L858R-positive lung adenocarcinoma and may potentially be a novel biomarker to guide treatment decisions.

Self-assembled nanoparticles based on the c(RGDfk peptide for the delivery of siRNA targeting the VEGFR2 gene for tumor therapy

Directory of Open Access Journals (Sweden)

Liu L

2014-07-01

Full Text Available Li Liu,1 Xiaoxia Liu,1 Qian Xu,1 Ping Wu,2 Xialin Zuo,3 Jingjing Zhang,1 Houliang Deng,1 Zhuomin Wu,1 Aimin Ji1 1Department of Pharmacy, Zhujiang Hospital, Southern Medical University, Guangzhou, People’s Republic of China; 2Department of Pharmacy, Chengdu Integrated TCM & Western Medicine Hospital, Chengdu, People’s Republic of China; 3Institute of Neurosciences and the Second Affiliated Hospital of Guangzhou Medical University, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Guangzhou, People’s Republic of China Abstract: The clinical application of small interfering RNA (siRNA has been restricted by their poor intracellular uptake, low serum stability, and inability to target specific cells. During the last several decades, a great deal of effort has been devoted to exploring materials for siRNA delivery. In this study, biodegradable, tumor-targeted, self-assembled peptide nanoparticles consisting of cyclo(Arg–Gly–Asp–d–Phe–Lys-8–amino–3,6–dioxaoctanoic acid–β–maleimidopropionic acid (hereafter referred to as RPM were found to be an effective siRNA carrier both in vitro and in vivo. The nanoparticles were characterized based on transmission electron microscopy, circular dichroism spectra, and dynamic light scattering. In vitro analyses showed that the RPM/VEGFR2-siRNA exhibited negligible cytotoxicity and induced effective gene silencing. Delivery of the RPM/VEGFR2 (zebrafish-siRNA into zebrafish embryos resulted in inhibition of neovascularization. Administration of RPM/VEGFR2 (mouse-siRNA to tumor-bearing nude mice led to a significant inhibition of tumor growth, a marked reduction of vessels, and a downregulation of VEGFR2 (messenger RNA and protein in tumor tissue. Furthermore, the levels of IFN-α, IFN-γ, IL-12, and IL-6 in mouse serum, assayed via enzyme-linked immunosorbent assay, did not indicate any immunogenicity of the RPM/VEGFR2�

Snake venom VEGF Vammin induces a highly efficient angiogenic response in skeletal muscle via VEGFR-2/NRP specific signaling.

Science.gov (United States)

Toivanen, Pyry I; Nieminen, Tiina; Laakkonen, Johanna P; Heikura, Tommi; Kaikkonen, Minna U; Ylä-Herttuala, Seppo

2017-07-17

Vascular Endothelial Growth Factors (VEGFs) are promising molecules for the treatment of ischemic diseases by pro-angiogenic therapy. Snake venom VEGFs are a novel subgroup with unique receptor binding profiles and as such are potential new therapeutic agents. We determined the ligand-receptor interactions, gene regulation and angiogenic properties of Vipera ammodytes venom VEGF, Vammin, and compared it to the canonical angiogenic factor VEGF-A to evaluate the use of Vammin for therapeutic angiogenesis. Vammin efficiently induced VEGFR-2 mediated proliferation and expression of genes associated with proliferation, migration and angiogenesis. VEGF-A 165 and especially VEGF-A 109 induced less pronounced effects. Vammin regulates a number of signaling pathways by inducing the expression of NR4A family nuclear receptors and regulators of calcium signaling and MAP kinase pathways. Interestingly, MARC1, which encodes an enzyme discovered to catalyze reduction of nitrate to NO, was identified as a novel VEGFR-2 regulated gene. In rabbit skeletal muscle adenoviral delivery of Vammin induced prominent angiogenic responses. Both the vector dose and the co-receptor binding of the ligand were critical parameters controlling the type of angiogenic response from sprouting angiogenesis to vessel enlargement. Vammin induced VEGFR-2/NRP-1 mediated signaling more effectively than VEGF-A, consequently it is a promising candidate for development of pro-angiogenic therapies.

Correlation Among Six Biologic Factors (p53, p21WAF1, MIB-1, EGFR, HER2, and Bcl-2) and Clinical Outcomes After Curative Chemoradiation Therapy in Squamous Cell Cervical Cancer

International Nuclear Information System (INIS)

Yamashita, Hideomi; Murakami, Naoya; Asari, Takao; Okuma, Kae; Ohtomo, Kuni; Nakagawa, Keiichi

2009-01-01

Purpose: The expressions of six cell-cycle-associated proteins were analyzed in cervical squamous cell carcinomas in correlation in a search for prognostic correlations in tumors treated with concurrent chemoradiation therapy (cCRT). Methods and Materials: The expressions of p53, p21/waf1/cip1, molecular immunology borstel-1 (MIB-1), epidermal growth factor receptor (EGFR), human epidermal growth factor receptor type 2 (HER2), and Bcl-2 were studied using an immunohistochemical method in 57 cases of cervical squamous cell carcinoma treated with cCRT. Patients received cCRT between 1998 and 2005. The mean patient age was 61 years (range, 27-82 years). The number of patients with Stage II, III, and IVA disease was 18, 29, and 10, respectively. Results: The number of patients with tumors positive for p53, p21/waf1/cip1, MIB-1, EGFR, HER2, and Bcl-2 was 26, 24, 49, 26, 13, and 11, respectively; no significant correlation was noted. The 5-year overall survival rates of HER2-positive and -negative patients was 76% vs. 44%, which was of borderline significance (p = 0.0675). No significant correlation was noted between overall survival and expressions of p53, p21/waf1/cip1, MIB-1, EGFR, and Bcl-2. No correlation was observed between local control and expression of any of the proteins. Conclusion: Expression of HER2 protein had a weak impact of borderline significance on overall survival in squamous cell carcinoma of the uterine cervix treated with cCRT. However, no clinical associations could be established for p53, p21/waf1/cip1, MIB-1, EGFR, and Bcl-2 protein expressions.

Probiotic yeast inhibits VEGFR signaling and angiogenesis in intestinal inflammation.

Directory of Open Access Journals (Sweden)

Xinhua Chen

Full Text Available Saccharomyces boulardii (Sb can protect against intestinal injury and tumor formation, but how this probiotic yeast controls protective mucosal host responses is unclear. Angiogenesis is an integral process of inflammatory responses in inflammatory bowel diseases (IBD and required for mucosal remodeling during restitution. The aim of this study was to determine whether Sb alters VEGFR (vascular endothelial growth factor receptor signaling, a central regulator of angiogenesis.HUVEC were used to examine the effects of Sb on signaling and on capillary tube formation (using the ECMatrix™ system. The effects of Sb on VEGF-mediated angiogenesis were examined in vivo using an adenovirus expressing VEGF-A(164 in the ears of adult nude mice (NuNu. The effects of Sb on blood vessel volume branching and density in DSS-induced colitis was quantified using VESsel GENeration (VESGEN software.1 Sb treatment attenuated weight-loss (p<0.01 and histological damage (p<0.01 in DSS colitis. VESGEN analysis of angiogenesis showed significantly increased blood vessel density and volume in DSS-treated mice compared to control. Sb treatment significantly reduced the neo-vascularization associated with acute DSS colitis and accelerated mucosal recovery restoration of the lamina propria capillary network to a normal morphology. 2 Sb inhibited VEGF-induced angiogenesis in vivo in the mouse ear model. 3 Sb also significantly inhibited angiogenesis in vitro in the capillary tube assay in a dose-dependent manner (p<0.01. 4 In HUVEC, Sb reduced basal VEGFR-2 phosphorylation, VEGFR-2 phosphorylation in response to VEGF as well as activation of the downstream kinases PLCγ and Erk1/2.Our findings indicate that the probiotic yeast S boulardii can modulate angiogenesis to limit intestinal inflammation and promote mucosal tissue repair by regulating VEGFR signaling.

Association between CFH, CFB, ARMS2, SERPINF1, VEGFR1 and VEGF polymorphisms and anatomical and functional response to ranibizumab treatment in neovascular age-related macular degeneration.

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Cobos, Estefania; Recalde, Sergio; Anter, Jaouad; Hernandez-Sanchez, Maria; Barreales, Carla; Olavarrieta, Leticia; Valverde, Alicia; Suarez-Figueroa, Marta; Cruz, Fernando; Abraldes, Maximino; Pérez-Pérez, Julian; Fernández-Robredo, Patricia; Arias, Luis; García-Layana, Alfredo

2018-03-01

We sought to determine if specific genetic single nucleotide polymorphisms (SNPs) influence vascular endothelial growth factor inhibition response to ranibizumab in neovascular age-related macular degeneration (AMD). A total of 403 Caucasian patients diagnosed with exudative AMD were included. After a three-injection loading phase, a pro re nata regimen was followed. Nine SNPs from six different genes (CFH, CFB, ARMS2, SERPINF1, VEGFR1, VEGF) were genotyped. Non-genetic risk factors (gender, smoking habit and hypertension) were also assessed. Patients were classified as good or poor responders (GR or PR) according to functional (visual acuity), anatomical (foveal thickness measured by OCT) and fluid criteria (fluid/no fluid measured by OCT). Hypertension was the environmental factor with the strongest poor response association with ranibizumab in the anatomical measure after the loading phase (p = 0.0004; OR 3.7; 95% CI, 2.4-5.8) and after 12 months of treatment (p = 10 -5 ; OR 2.3; 95% CI, 1.5-3.4). The genetic variants rs12614 (CFB), rs699947 (VEGFA) and rs7993418 (VEGFR1) predisposed patients to a good response, while rs12603486 and rs1136287 (SERPINF1) were associated with a poor response. The protective genotype of rs800292 variant (CFH) was also associated with a poor anatomical response (p 0.0048). All these data suggest that genetics play an important role in treatment response in AMD patients. © 2017 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

Genetic risk variants in the CDKN2A/B, RTEL1 and EGFR genes are associated with somatic biomarkers in glioma.

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Ghasimi, Soma; Wibom, Carl; Dahlin, Anna M; Brännström, Thomas; Golovleva, Irina; Andersson, Ulrika; Melin, Beatrice

2016-05-01

During the last years, genome wide association studies have discovered common germline genetic variants associated with specific glioma subtypes. We aimed to study the association between these germline risk variants and tumor phenotypes, including copy number aberrations and protein expression. A total of 91 glioma patients were included. Thirteen well known genetic risk variants in TERT, EGFR, CCDC26, CDKN2A, CDKN2B, PHLDB1, TP53, and RTEL1 were selected for investigation of possible correlations with the glioma somatic markers: EGFR amplification, 1p/19q codeletion and protein expression of p53, Ki-67, and mutated IDH1. The CDKN2A/B risk variant, rs4977756, and the CDKN2B risk variant, rs1412829 were inversely associated (p = 0.049 and p = 0.002, respectively) with absence of a mutated IDH1, i.e., the majority of patients homozygous for the risk allele showed no or low expression of mutated IDH1. The RTEL1 risk variant, rs6010620 was associated (p = 0.013) with not having 1p/19q codeletion, i.e., the majority of patients homozygous for the risk allele did not show 1p/19q codeletion. In addition, the EGFR risk variant rs17172430 and the CDKN2B risk variant rs1412829, both showed a trend for association (p = 0.055 and p = 0.051, respectively) with increased EGFR copy number, i.e., the majority of patients homozygote for the risk alleles showed chromosomal gain or amplification of EGFR. Our findings indicate that CDKN2A/B risk genotypes are associated with primary glioblastoma without IDH mutation, and that there is an inverse association between RTEL1 risk genotypes and 1p/19q codeletion, suggesting that these genetic variants have a molecular impact on the genesis of high graded brain tumors. Further experimental studies are needed to delineate the functional mechanism of the association between genotype and somatic genetic aberrations.

Contrast-Enhanced Ultrasound with VEGFR2-Targeted Microbubbles for Monitoring Regorafenib Therapy Effects in Experimental Colorectal Adenocarcinomas in Rats with DCE-MRI and Immunohistochemical Validation.

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Ralf Stefan Eschbach

Full Text Available To investigate contrast-enhanced ultrasound (CEUS with VEGFR2-targeted microbubbles for monitoring therapy effects of regorafenib on experimental colon carcinomas in rats with correlation to dynamic contrast-enhanced MRI (DCE-MRI and immunohistochemistry.Human colorectal adenocarcinoma xenografts (HT-29 were implanted subcutaneously in n = 21 (n = 11 therapy group; n = 10 control group female athymic nude rats (Hsd: RH-Foxn1rnu. Animals were imaged at baseline and after a one-week daily treatment with regorafenib or a placebo (10 mg/kg bodyweight, using CEUS with VEGFR2-targeted microbubbles and DCE-MRI. In CEUS tumor perfusion was assessed during an early vascular phase (wash-in area under the curve = WiAUC and VEGFR2-specific binding during a late molecular phase (signal intensity after 8 (SI8min and 10 minutes (SI10min, using a conventional 15L8 linear transducer (transmit frequency 7 MHz, dynamic range 80 dB, depth 25 mm. In DCE-MRI functional parameters plasma flow (PF and plasma volume (PV were quantified. For validation purposes, CEUS parameters were correlated with DCE-MRI parameters and immunohistochemical VEGFR2, CD31, Ki-67 and TUNEL stainings.CEUS perfusion parameter WiAUC decreased significantly (116,989 ± 77,048 a.u. to 30,076 ± 27,095a.u.; p = 0.005 under therapy with no significant changes (133,932 ± 65,960 a.u. to 84,316 ± 74,144 a.u.; p = 0.093 in the control group. In the therapy group, the amount of bound microbubbles in the late phase was significantly lower in the therapy than in the control group on day 7 (SI8min: 283 ± 191 vs. 802 ± 460 a.u.; p = 0.006; SI10min: 226 ± 149 vs. 645 ± 461 a.u.; p = 0.009. PF and PV decreased significantly (PF: 147 ± 58 mL/100 mL/min to 71 ± 15 mL/100 mL/min; p = 0.003; PV: 13 ± 3% to 9 ± 4%; p = 0.040 in the therapy group. Immunohistochemistry revealed significantly fewer VEGFR2 (7.2 ± 1.8 vs. 17.8 ± 4.6; p < 0.001, CD31 (8.1 ± 3.0 vs. 20.8 ± 5.7; p < 0.001 and Ki-67 (318.7 �

Ginsenoside Rg1 enhances lymphatic transport of intrapulmonary silica via VEGF-C/VEGFR-3 signaling in silicotic rats.

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Yu, Jie; Mao, Lijun; Guan, Li; Zhang, Yanlin; Zhao, Jinyuan

2016-03-25

Ginsenoside Rg1, extracted mainly from Panax ginseng, has been shown to exert strong pro-angiogenic activities in vivo. But it is unclear whether ginsenoside Rg1 could promote lung lymphangiogenesis to improve lymphatic transport of intrapulmonary silica in silicotic rats. Here we investigated the effect of ginsenoside Rg1 on lymphatic transport of silica during experimental silicosis, and found that ginsenoside Rg1 treatment significantly raised the silicon content in tracheobronchial lymph nodes and serum to reduce the silicon level in lung interstitium, meanwhile increased pulmonary lymphatic vessel density by enhancing the protein and mRNA expressions of vascular endothelial growth factor-C (VEGF-C) and vascular endothelial growth factor receptor-3 (VEGFR-3). The stimulative effect of ginsenoside Rg1 on lymphatic transport of silica was actively correlated with its pro-lymphangiogenic identity. And VEGFR-3 inhibitor SAR131675 blocked these above effects of ginsenoside Rg1. These findings suggest that ginsenoside Rg1 exhibits good protective effect against lung burden of silica during experimental silicosis through improving lymphatic transport of intrapulmonary silica, which is potentially associated with the activation of VEGF-C/VEGFR-3 signaling pathway. Copyright © 2016 Elsevier Inc. All rights reserved.

RCAN1.4 regulates VEGFR-2 internalisation, cell polarity and migration in human microvascular endothelial cells.

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Alghanem, Ahmad F; Wilkinson, Emma L; Emmett, Maxine S; Aljasir, Mohammad A; Holmes, Katherine; Rothermel, Beverley A; Simms, Victoria A; Heath, Victoria L; Cross, Michael J

2017-08-01

Regulator of calcineurin 1 (RCAN1) is an endogenous inhibitor of the calcineurin pathway in cells. It is expressed as two isoforms in vertebrates: RCAN1.1 is constitutively expressed in most tissues, whereas transcription of RCAN1.4 is induced by several stimuli that activate the calcineurin-NFAT pathway. RCAN1.4 is highly upregulated in response to VEGF in human endothelial cells in contrast to RCAN1.1 and is essential for efficient endothelial cell migration and tubular morphogenesis. Here, we show that RCAN1.4 has a role in the regulation of agonist-stimulated VEGFR-2 internalisation and establishment of endothelial cell polarity. siRNA-mediated gene silencing revealed that RCAN1 plays a vital role in regulating VEGF-mediated cytoskeletal reorganisation and directed cell migration and sprouting angiogenesis. Adenoviral-mediated overexpression of RCAN1.4 resulted in increased endothelial cell migration. Antisense-mediated morpholino silencing of the zebrafish RCAN1.4 orthologue revealed a disrupted vascular development further confirming a role for the RCAN1.4 isoform in regulating vascular endothelial cell physiology. Our data suggest that RCAN1.4 plays a novel role in regulating endothelial cell migration by establishing endothelial cell polarity in response to VEGF.

Design and discovery of thioether and nicotinamide containing sorafenib analogues as multikinase inhibitors targeting B-Raf, B-RafV600E and VEGFR-2.

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Sun, Shaofeng; He, Zuopeng; Huang, Mindong; Wang, Ningning; He, Zongzhong; Kong, Xiangkai; Yao, Jianwen

2018-04-03

New sorafenib derivatives containing thioether and nicotinamide moiety were designed and synthesized as B-Raf, B-Raf V600E and VEGFR-2 multikinase inhibitors. Their in vitro enzymatic inhibitory activities against B-Raf, B-Raf V600E and VEGFR-2 and their antiproliferative activities against HCT-116 and B16BL6 cell lines were evaluated and described. Most of the compounds showed potent activities against both cell lines and specific kinases. Compounds a1, b1 and c4, which exhibited the most potent inhibitory activities against B-Raf with IC 50 of 21 nM, 27 nM and 17 nM, B-Raf V600E with IC 50 of 29 nM, 28 nM and 16 nM, VEGFR-2 with IC 50 of 84 nM, 46 nM and 63 nM, respectively, and good antiproliferative activities, also demonstrated competitive antiangiogenic activities to sorafenib in in vitro HUVEC tube formation assay. Copyright © 2018 Elsevier Ltd. All rights reserved.

Cell adhesion and EGFR activation regulate EphA2 expression in cancer

DEFF Research Database (Denmark)

Larsen, Alice Bjerregaard; Stockhausen, Marie-Thérése; Poulsen, Hans Skovgaard

2010-01-01

largely unknown. Here we show that the expression of EphA2 in in vitro cultured cells, is restricted to cells growing adherently and that adhesion-induced EphA2 expression is dependent upon activation of the epidermal growth factor receptor (EGFR), mitogen activated protein kinase kinase (MEK) and Src...... family kinases (SRC). Moreover, the results show that adhesion-induced EGFR activation and EphA2 expression is affected by interactions with extracellular matrix (ECM) proteins working as integrin ligands. Stimulation with the EphA2 ligand, ephrinA1 inhibited ERK phosphorylation and cancer cell viability....... These effects were however abolished by activation of the EGF-receptor ligand system favoring Ras/MAPK signaling and cell proliferation. Based on our results, we propose a regulatory mechanism where cell adhesion induces EGFR kinase activation and EphA2 expression; and where the effect of ephrinA1 mediated...

Molecular imaging reveals elevated VEGFR-2 expression in retinal capillaries in diabetes: a novel biomarker for early diagnosis

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Sun, Dawei; Nakao, Shintaro; Xie, Fang; Zandi, Souska; Bagheri, Abouzar; Kanavi, Mozhgan Rezaei; Samiei, Shahram; Soheili, Zahra-Soheila; Frimmel, Sonja; Zhang, Zhongyu; Ablonczy, Zsolt; Ahmadieh, Hamid; Hafezi-Moghadam, Ali

2014-01-01

Diabetic retinopathy (DR) is a microvascular complication of diabetes and a leading cause of vision loss. Biomarkers and methods for early diagnosis of DR are urgently needed. Using a new molecular imaging approach, we show up to 94% higher accumulation of custom designed imaging probes against vascular endothelial growth factor receptor 2 (VEGFR-2) in retinal and choroidal vessels of diabetic animals (PM. R., Samiei, S., Soheili, Z.-S., Frimmel, S., Zhang, Z., Ablonczy, Z., Ahmadieh, H., Hafezi-Moghadam, A. Molecular imaging reveals elevated VEGFR-2 expression in retinal capillaries in diabetes: a novel biomarker for early diagnosis. PMID:24903276

Aliphatic acetogenin constituents of avocado fruits inhibit human oral cancer cell proliferation by targeting the EGFR/RAS/RAF/MEK/ERK1/2 pathway

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D’Ambrosio, Steven M.; Han, Chunhua; Pan, Li; Kinghorn, A. Douglas; Ding, Haiming

2011-01-01

Avocado (Persea americana) fruits are consumed as part of the human diet and extracts have shown growth inhibitory effects in various types of human cancer cells, although the effectiveness of individual components and their underlying mechanism are poorly understood. Using activity-guided fractionation of the flesh of avocado fruits, a chloroform-soluble extract (D003), was identified that exhibited high efficacy towards premalignant and malignant human oral cancer cell lines. From this extract, two aliphatic acetogenins of previously known structure were isolated, compounds 1 [(2S,4S)-2,4-dihydroxyheptadec-16-enyl acetate] and 2 [(2S,4S)-2,4-dihydroxyheptadec-16-ynyl acetate]. In this study, we show for the first time that the growth inhibitory efficacy of this chloroform extract is due to blocking the phosphorylation of EGFR (Tyr1173), c-RAF (Ser338), and ERK1/2 (Thr202/Tyr204) in the EGFR/RAS/RAF/MEK/ERK1/2 cancer pathway. Compound 1 and 2 both inhibited phosphorylation of c-RAF (Ser338) and ERK1/2 (Thr202/Tyr204). Compound 2, but not compound 1, prevented EGF-induced activation of EGFR (Tyr1173). When compounds 1 and 2 were combined they synergistically inhibited c-RAF (Ser338) and ERK1/2 (Thr202/Tyr204) phosphorylation, and human oral cancer cell proliferation. The present data suggest that the potential anticancer activity of avocado fruits is due to a combination of specific aliphatic acetogenins that target two key components of the EGFR/RAS/RAF/MEK/ERK1/2 cancer pathway. PMID:21596018

Impact of vascular endothelial growth factor (VEGF and vascular endothelial growth factor receptor (VEGFR single nucleotide polymorphisms on outcome in gastroenteropancreatic neuroendocrine neoplasms.

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Rossana Berardi

Full Text Available Angiogenesis represents a key event in cancer development, leading to local invasion e metastatization, and might be considered a basic feature in gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs with a high expression of angiogenic molecules. We aimed to analyze the prognostic and predictive role of angiogenic factors in GEP-NENs through the analysis of single nucleotide polymorphisms (SNPs of VEGF-A, VEGFR2 and VEGFR3. The genomic DNA of 58 consecutive patients with GEP-NENs treated at our Institution was extracted from peripheral blood. Two SNPs were identified respectively in VEGF-A (rs2010963G>C, rs699947A>C, VEGFR-2 (rs2305948C>T, rs1870377T>A, and VEGFR-3 (rs307821T>C, rs307826C>A gene. Gene polymorphisms were determined by Real-Time PCR using TaqMan assays. Median age was 57 years (range 24-79 years; 32 patients were male and 77.5% of NENs were localized in the pancreas. The allele frequency of VEGFR-2 rs2305948T and of VEGF-A rs2010963C showed a trend of higher frequency than in general population (12.1% vs. 8.0% and 34.5% vs. 31.2%, respectively. Three out SNPs (VEGF-A rs699947C, VEGF-A rs2010963GC and VEGFR-3 rs307821C showed a correlation with an increased risk of disease relapse. Moreover median PFS changes according to the presence of 0-1 SNPs (20.7% of cases; 61.9 months, 2 SNPs (25.9%; 49.2 months and 3 SNPs (53.4%; 27.8 months (p = 0.034. Results suggest, for the first time, that specific SNPs in VEGF-A and VEGFR-3 correlate with poor prognosis in GEP-NENs. The identification of this new prognostic factor might be helpful in order to optimize the management of these heterogeneous neoplasms.

4-Hydroxynonenal activates Src through a non-canonical pathway that involves EGFR/PTP1B

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Zhang, Hongqiao; Forman, Henry Jay

2015-01-01

Src, a non-receptor protein tyrosine kinase involved in many biological processes, can be activated through both redox-dependent and independent mechanisms. 4-Hydroxy-2-nonenal (HNE) is a lipid peroxidation product that is increased in pathophysiological conditions associated with Src activation. This study examined how HNE activates human c-Src. In the canonical pathway Src activation is initiated by dephosphorylation of pTyr530 followed by conformational change that causes Src auto-phosphorylation at Tyr419 and its activation. HNE increased Src activation in both dose- and time-dependent manner, while it also increased Src phosphorylation at Tyr530 (pTyr530 Src), suggesting that HNE activated Src via a non-canonical mechanism. Protein tyrosine phosphatase 1B inhibitor (539741), at concentrations that increased basal pTyr530 Src, also increased basal Src activity and significantly reduced HNE-mediated Src activation. The EGFR inhibitor, AG1478, and EGFR silencing, abrogated HNE-mediated EGFR activation and inhibited basal and HNE-induced Src activity. In addition, AG1478 also eliminated the increase of basal Src activation by a PTP1B inhibitor. Taken together these data suggest that HNE can activate Src partly through a non-canonical pathway involving activation of EGFR and inhibition of PTP1B. PMID:26453921

Role of GPER1, EGFR and CXCR1 in differentiating between malignant follicular thyroid carcinoma and benign follicular thyroid adenoma

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Zhao, Le; Zhu, Xiao-Yun; Jiang, Rong; Xu, Man; Wang, Ni; Chen, George G; Liu, Zhi-Min

2015-01-01

It is extremely difficult to discriminate between follicular thyroid carcinoma (FTC) and follicular thyroid adenoma (FTA) before surgery, because the morphologies of carcinoma cells and adenoma cells obtained by fine needle aspiration biopsy (FNAB) are similar. Molecular markers may be helpful on this issue. The purpose of this study was to assess the role of GPER1, EGFR and CXCR1 in differential diagnosis between FTC and FTA. GPER1, EGFR and CXCR1 mRNA expression levels were examined in 15 FTCs and 10 FTAs using real-time RT-PCR. FTC showed to have significantly increased mRNA levels of the three molecules compared to FTA (P FTA, respectively. Statistical analysis showed that GPER1, EGFR and CXCR1 protein expression were correlated with one another in FTC and concomitant high expression of the three molecules had stronger correlation with the occurrence of FTC than did each alone. The positive predictive values (PPV) for concomitant high expression of the three molecules for discriminating between FTC and FTA were 91.0% for GPER1/EGFR, 93.8% for GPER1/CXCR1, 92.3% for EGFR/CXCR1 and 98.2% for GPER1/EGFR/CXCR1, respectively. These results indicated that the evaluation of GPER1, EGFR and CXCR1 concomitant high expression may be helpful in differential diagnosis between FTC and FTA. PMID:26617848

Assessment and prognostic analysis of EGFR mutations or/and HER2 overexpression in Uygur's Non-small Cell Lung Cancer.

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Shen, Hongli; Du, Guoli; Liu, Zhonghua; Bao, Jianling; Yu, Qin; Jia, Chunli; Liang, Xuelin; Shan, Li

2015-01-01

The epidermal growth factor receptor (EGFR) mutations and human epidermal growth factor receptor HER-2/neu (HER2) have been established roles in the signal transduction pathways leading to cell growth and differentiation. The present study focus on the significance of EGFR mutations combined with HER2 overexpression on survival outcomes in Non-small Cell Lung Cancer patients in Uygur population. A total of 111 consecutive Uygurods: A total of 111 consecutive Cell Lung Cancer under went lung Cell Lung biopsy or surgery at the Affiliated Tumor Hospital of Xin Jiang Medical University between March 2009 and January 2013 were included in this retrospective study. All the patients included had received gefitinib 250 mg once daily. The HER2 expression were evaluated by immunohistochemical staining with score of membranous staining being 0 = none, 1 = weak, 2 = 10-30% cells, 3≥30% cells stained, and Real-time PCR techniques were conducted to detect mutations of EGFR through 21 kinds of human EGFR gene mutation detection kits. A retrospective review of the medical records was analyzed to determine the correlation between the presence of EGFR mutations combined with HER2 overexpression and clinicopathological factors. The overall rate of EGFR mutation was 10.81% (n = 12), which mainly involved exons 19 (83.33%, n = 10), 21 (16.67%, n = 2). The overall rate of HER2 overexpression was 21.62% (n = 24). EGFR mutation combined with HER2 overexpression analysis was performed in 111 patients, with an overall rate of 5.41% (n = 6). Median progression-free survival and overall survival were significantly longer in the EGFR mutations group than in the wild type group (PFS: 10.0±1.5 versus 3.8±1.4 months, P = 0.000; OS: 27.3±2.9 versus 19.1±4.7 months, P = 0.000). The ORR in patients with HER2 overexpression was 29.17%, and 13.80% in those patients with HER2 negative, but no significant difference (P = 0.121). The median PFS and OS in HER2 positive group showed no significant

Benzo[g]quinazolin-based scaffold derivatives as dual EGFR/HER2 inhibitors.

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Ghorab, Mostafa M; Alsaid, Mansour S; Soliman, Aiten M; Al-Mishari, Abdullah A

2018-12-01

Targeting EGFR has proven to be beneficial in the treatment of several types of solid tumours. So, a series of novel 2-(4-oxo-3-(4-sulfamoylphenyl)-3,4-dihydrobenzo[g]quinazolin-2-ylthio)-N-substituted acetamide 5-19 were synthesised from the starting material 4-(2-mercapto-4-oxobenzo[g]quinazolin-3(4H)-yl) benzenesulfonamide 4, to be evaluated as dual EGFR/HER2 inhibitors. The target compounds 5-19, were screened for their cytotoxic activity against A549 lung cancer cell line. The percentage inhibition of EGFR enzyme was measured and compared with erlotinib as the reference drug. Compounds 6, 8, 10, and 16 showed excellent EGFR inhibitory activity and were further selected for screening as dual EGFR/HER2 inhibitors. The four selected compounds showed IC 50 ranging from 0.009 to 0.026 µM for EGFR and 0.021 to 0.069 µM for the HER2 enzyme. Compound 8 was found to be the most potent in this study with IC 50 0.009 and 0.021 µM for EGFR and HER2, respectively.

PGE2 mediates EGFR internalization and nuclear translocation via caveolin endocytosis promoting its transcriptional activity and proliferation in human NSCLC cells.

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Bazzani, Lorenzo; Donnini, Sandra; Giachetti, Antonio; Christofori, Gerhard; Ziche, Marina

2018-03-13

Prostaglandin E 2 (PGE 2 ) contributes to tumor progression by promoting cancer cell growth, invasion and by creating a favorable pro-tumor microenvironment. PGE 2 has been reported to transactivate and internalize into the nucleus receptor tyrosine kinases such as Epidermal growth factor receptor (EGFR), thereby supporting tumor progression. Here we demonstrate that in non-small cell lung carcinoma (NSCLC) cells, PGE 2 induces EGFR nuclear translocation via different dynamin-dependent endocytic pathways, promotes the formation of an EGFR-STAT3 complex, affects nuclear EGFR target gene expression and mediates tumor cell proliferation. Indeed, we find that PGE 2 induces EGFR internalization and consequent nuclear import through Clathrin- and Caveolin-mediated endocytosis and through the interaction of EGFR with Importin β1. Within the nucleus, EGFR forms a complex with STAT3, an event blocked by ablation of Clathrin Heavy Chain or Caveolin-1. The combination of EGF and PGE 2 prolongs nuclear EGFR transcriptional activity manifested by the upregulation of CCND1 , PTGS2 , MYC and NOS2 mRNA levels and potentiates nuclear EGFR-induced NSCLC cell proliferation. Additionally, NSCLC patients with high expression of a nuclear EGFR gene signature display shorter survival times than those with low expression, thus showing a putative correlation between nuclear EGFR and poor prognosis in NSCLC. Together, our findings indicate a complex mechanism underlying PGE 2 -induced EGF/EGFR signaling and transcriptional control, which plays a key role in cancer progression.

Prevention of palatable diet-induced hyperphagia in rats by central injection of a VEGFR kinase inhibitor.

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Branch, Audrey; Bobilev, Anastasia; Negrao, Nuria Waddington; Cai, Haini; Shen, Ping

2015-02-01

Our previous studies have demonstrated a critical role of a VEGFR-like signaling pathway in hunger-driven overeating of sugar-rich food in Drosophila larvae. In the current study, we investigate whether the VEGFR signaling mechanism plays a similar role in the feeding behavior of vertebrates using male Sprague Dawley rats. Young rats were treated intracerebroventrically (i.c.v.) with a single dose (2 μg) of VEGFR2 Tyrosine Kinase Inhibitor V (VTKI-V), an N-cyclopropylnaphthamide compound that selectively inhibits the kinase activity of VEGFR2 at subnanomolar concentrations. We find that animals treated with VTKI-V showed markedly attenuated overconsumption of palatable food that is sweet and fatty. The subsequent meal pattern analysis reveals that is achieved by consumption of smaller, shorter meals. Furthermore, i.c.v. injection of VTKI-V decreased body weight gain in animals fed with CHOW or palatable food. These inhibitory effects of the drug were detectable within 24h and persisted for at least five days. Given that body weight was affected by the drug regardless of diet while food intake was selectively altered in palatable diet fed animals, these results raise the possibility that i.c.v. injection of VTKI-V may interfere the functions of two separate VEGFR-mediated mechanisms: one promotes overconsumption of palatable food, and the other mediates body weight gain. Copyright © 2014 Elsevier B.V. All rights reserved.

AT-101 enhances gefitinib sensitivity in non-small cell lung cancer with EGFR T790M mutations

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Zhao, Ren; Zhou, Shun; Xia, Bing; Zhang, Cui-ying; Hai, Ping; Zhe, Hong; Wang, Yan-yang

2016-01-01

Although epidermal growth factor receptor tyrosine kinase inhibitors (EGFR TKIs) have become the standard care of patients with advanced EGFR-mutant non-small cell lung cancer (NSCLC), development of acquired resistance is inevitable. A secondary mutation of threonine 790 (T790M) is associated with approximately half of the cases of acquired resistance. Strategies or agents to overcome this type of resistance are still limited. In this study, enhanced antitumor effect of AT-101, a-pan-Bcl-2 inhibitor, on gefitinib was explored in NSCLC with T790M mutation. The effect of cotreatment with AT-101 and gefitinib on the viability of NSCLC cell lines harboring acquired T790M mutation was investigated using the MTT assay. The cellular apoptosis of NSCLC cells after cotreatment with AT-101 and gefitinib was assessed by FITC-annexin V/PI assay and Western blots analysis. The potential underlying mechanisms of the enhanced therapeutic effect for AT-101 was also studied using Western blots analysis. The in vivo anti-cancer efficacy of the combination with AT-101 and gefitinib was examined in a mouse xenograft model. In this study, we found that treatment with AT-101 in combination with gefitinib significantly inhibited cell proliferation, as well as promoted apoptosis of EGFR TKIs resistant lung cancer cells. The apoptotic effects of the use of AT-101 was related to the blocking of antiapoptotic protein: Bcl-2, Bcl-xl, and Mcl-1 and downregrulation of the molecules in EGFR pathway. The observed enhancements of tumor growth suppression in xenografts supported the reverse effect of AT-101 in NSCLC with T790M mutation, which has been found in in vitro studies before. AT-101 enhances gefitinib sensitivity in NSCLC with EGFR T790M mutations. The addition of AT-101 to gefitinib is a promising strategy to overcome EGFR TKIs resistance in NSCLC with EGFR T790M mutations

Privileged scaffolds or promiscuous binders: a glance of pyrrolo[2,1-f][1,2,4]triazines and related bridgehead nitrogen heterocycles in medicinal chemistry.

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Song, Yu'ning; Zhan, Peng; Zhang, Qingzhu; Liu, Xinyong

2013-01-01

Pyrrolo[2,1-f][1,2,4]triazine template, a unique bridgehead nitrogen heterocycle, certainly deserves the title of "privileged scaffold" in the drug discovery field because of the versatility and potential to yield derivatives with a wide range of biological activities, such as anti-anaplastic lymphoma kinase (ALK), Janus kinase 2 (JAK2), VEGFR-2, EGFR and/or HER2, Met kinase, p38α mitogen-activated protein (MAP) kinase and insulin-like growth factor receptor (IGF-1R) kinase activities, etc. These different biological properties of pyrrolo[2,1-f][1,2,4]triazine derivatives have motivated new studies in searching for novel derivatives with improved activity and also other applications in pharmaceutical field. However, no systematic review is available in the literature on the pyrrolo[2,1- f][1,2,4]triazine derivatives concerning the design of potent drug-like compounds. Owing to the importance of this heterocyclic system, the present paper is an attempt to the pharmacological activities, structural modifications and the structure-activity relationship (SAR) reported for bridgehead nitrogen heterocycles in the current literature, making an effort to highlight the importance and therapeutic potentials of the pyrrolo[2,1-f][1,2,4]triazine scaffold and its bridgehead nitrogen bioisosters as heterocyclic privileged medicinal scaffolds.

Retrospective Molecular Epidemiology Study of PD-L1 Expression in Patients with EGFR-Mutant Non-small Cell Lung Cancer.

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Cho, Jong Ho; Zhou, Wei; Choi, Yoon-La; Sun, Jong-Mu; Choi, Hyejoo; Kim, Tae-Eun; Dolled-Filhart, Marisa; Emancipator, Kenneth; Rutkowski, Mary Anne; Kim, Jhingook

2018-01-01

Data are limited on programmed death ligand 1 (PD-L1) expression in epidermal growth factor receptor ( EGFR )-mutant non-small cell lung cancer (NSCLC). We retrospectively evaluated the relationship between PD-L1 expression and recurrence-free survival (RFS) and overall survival in 319 patients with EGFR -mutant NSCLC who were treated at Samsung Medical Center from 2006 to 2014. Membranous PD-L1 expression on tumor cells was measured using the PD-L1 IHC 22C3 pharmDx antibody and reported as tumor proportion score (TPS). Kaplan-Meier methods, log-rank test, and Cox proportional hazards models were used for survival analysis. All patients had ≥1 EGFR mutation-54% in exon 19 and 39% in exon 21. Overall, 51% of patients had PD-L1-positive tumors. The prevalence of PD-L1 positivity was higher among patients with stages II-IV versus stage I disease (64% vs. 44%) and among patients with other EGFR mutations (75%) than with L858R mutation (39%) or exon 19 deletion (52%). PD-L1 positivity was associated with shorter RFS, with an adjusted hazard ratio of 1.52 (95% confidence interval [CI], 0.81 to 2.84; median, 18 months) for the PD-L1 TPS ≥ 50% group, 1.51 (95% CI, 1.02 to 2.21; median, 31 months) for the PD-L1 TPS 1%-49% group, and 1.51 (95% CI, 1.05 to 2.18) for the combined PD-L1-positive groups (TPS ≥ 1%) compared with the PD-L1-negative group (median, 35 months). PD-L1 expression is associated with disease stage and type of EGFR mutation. PD-L1 positivity might be associated with worse RFS among patients with surgically treated EGFR -mutant NSCLC.

TWIST1 a new determinant of epithelial to mesenchymal transition in EGFR mutated lung adenocarcinoma.

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Karine Pallier

Full Text Available Metastasis is a multistep process and the main cause of mortality in lung cancer patients. We previously showed that EGFR mutations were associated with a copy number gain at a locus encompassing the TWIST1 gene on chromosome 7. TWIST1 is a highly conserved developmental gene involved in embryogenesis that may be reactivated in cancers promoting both malignant conversion and cancer progression through an epithelial to mesenchymal transition (EMT. The aim of this study was to investigate the possible implication of TWIST1 reactivation on the acquisition of a mesenchymal phenotype in EGFR mutated lung cancer. We studied a series of consecutive lung adenocarcinoma from Caucasian non-smokers for which surgical frozen samples were available (n = 33 and showed that TWIST1 expression was linked to EGFR mutations (P<0.001, to low CDH1 expression (P<0.05 and low disease free survival (P = 0.044. To validate that TWIST1 is a driver of EMT in EGFR mutated lung cancer, we used five human lung cancer cell lines and demonstrated that EMT and the associated cell mobility were dependent upon TWIST1 expression in cells with EGFR mutation. Moreover a decrease of EGFR pathway stimulation through EGF retrieval or an inhibition of TWIST1 expression by small RNA technology reversed the phenomenon. Collectively, our in vivo and in vitro findings support that TWIST1 collaborates with the EGF pathway in promoting EMT in EGFR mutated lung adenocarcinoma and that large series of EGFR mutated lung cancer patients are needed to further define the prognostic role of TWIST1 reactivation in this subgroup.

EGFR and AKT1 overexpression are mutually exclusive and associated with a poor survival in resected gastric adenocarcinomas.

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Petrini, Iacopo; Lencioni, Monica; Vasile, Enrico; Fornaro, Lorenzo; Belluomini, Lorenzo; Pasquini, Giulia; Ginocchi, Laura; Caparello, Chiara; Musettini, Gianna; Vivaldi, Caterina; Caponi, Sara; Ricci, Sergio; Proietti, Agenese; Fontanini, Gabriella; Naccarato, Antonio Giuseppe; Nardini, Vincenzo; Santi, Stefano; Falcone, Alfredo

2018-02-14

The evaluation of molecular targets in gastric cancer has demonstrated the predictive role of HER2 amplification for trastuzumab treatment in metastatic gastric cancer. Besides HER2, other molecular targets are under evaluation in metastatic gastric tumors. However, very little is known about their role in resected tumors. We evaluated the expression of HER2, EGFR, MET, AKT1 and phospho-mTOR in resected stage II-III adenocarcinomas. Ninety-two patients with resected stomach (63%) or gastro-esophageal adenocarcinomas (27%) were evaluated. Antibodies anti-HER2, EGFR, MET, AKT1 and phospho-mTOR were used for immunostaining of formalin-fixed paraffin-embedded slides. Using FISH, HER2 amplification was evaluated in cases with an intermediate (+2) staining. EGFR overexpression (11%) was a poor prognostic factor for overall survival (3-year OS: 47% vs 77%; Log-Rank p= 0.033). MET overexpression (36%) was associated with a trend for a worse survival (3-year OS: 65% vs 77%; Log-Rank p= 0.084). HER2 amplification/overexpression and mTOR hyper-phosphorylation were observed in 13% and 48% of tumors, respectively. AKT1 overexpression (8%) was not a prognostic factor by itself (p= 0.234). AKT1 and EGFR overexpression was mutually exclusive and patients with EGFR or AKT1 overexpression experienced a poor prognosis (3-year OS: 52% vs. 79%, Log-Rank p= 0.005). EGFR is confirmed a poor prognostic factor in resected gastric cancers. We firstly describe a mutually exclusive overexpression of EGFR and AKT1 with potential prognostic implications, suggesting the relevance of this pathway for the growth of gastric cancers.

TNFR1 mediates TNF-α-induced tumour lymphangiogenesis and metastasis by modulating VEGF-C-VEGFR3 signalling

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Ji, Hong; Cao, Renhai; Yang, Yunlong

2014-01-01

of VEGF-C to coordinately activate VEGFR3. Genetic deletion of TNFR1 (Tnfr1(-/-)) in mice or depletion of tumour-associated macrophages (TAMs) virtually eliminates TNF-α-induced lymphangiogenesis and lymphatic metastasis. Gain-of-function experiments show that reconstitution of Tnfr1(+/+) macrophages...

Genetic variant in the 3'-untranslated region of VEGFR1 gene influences chronic obstructive pulmonary disease and lung cancer development in Chinese population.

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Wang, Hui; Yang, Lei; Deng, Jieqiong; Wang, Bo; Yang, Xiaorong; Yang, Rongrong; Cheng, Mei; Fang, Wenxiang; Qiu, Fuman; Zhang, Xin; Ji, Weidong; Ran, Pixin; Zhou, Yifeng; Lu, Jiachun

2014-09-01

Lung inflammation and epithelial to mesenchymal transition (EMT) are two pathogenic features for the two contextual diseases: chronic obstructive pulmonary disease (COPD) and lung cancer. VEGFR1 (or FLT1) plays a certain role in promoting tumour growth, inflammation and EMT. To simultaneously test the association between the single nucleotide polymorphisms (SNPs) in VEGFR1 and risk of COPD and lung cancer would reveal genetic mechanisms shared by these two diseases and joint aetiology. We conducted a two-population hospital-based case-control study. Three potential functional SNPs (rs664393, rs7326277 and rs9554314) were genotyped in southern Chinese and validated in eastern Chinese to explore their associations with COPD risk in 1511 COPD patients and 1677 normal lung function controls, and with lung cancer risk in 1559 lung cancer cases and 1679 cancer-free controls. We also detected the function of the promising SNP. Individuals carrying the rs7326277C (CT+CC) variant genotypes of VEGFR1 had a significant decrease in risk of both COPD (OR = 0.78; 95% CI = 0.68-0.90) and lung cancer (OR = 0.79; 95% CI = 0.64-0.98), compared with those carrying the rs7326277TT genotype. Functional assays further showed that the rs7326277C genotypes had lower transcriptional activity and caused decreased VEGFR expression, compared with the rs7326277TT genotype. However, no significant association was observed for the other two SNPs (rs664393 and rs9554314) and either COPD or lung cancer risk. Our data suggested that the rs7326277C variant of VEGFR1 could reduce both COPD and lung cancer risk by lowering VEGFR1 mRNA expression; the SNP might be a common susceptible locus for both COPD and lung cancer. © The Author 2014. Published by Oxford University Press on behalf of the UK Environmental Mutagen Society. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Targeting EGFR induced oxidative stress by PARP1 inhibition in glioblastoma therapy.

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Nitta, Masayuki; Kozono, David; Kennedy, Richard; Stommel, Jayne; Ng, Kimberly; Zinn, Pascal O; Kushwaha, Deepa; Kesari, Santosh; Inda, Maria-del-Mar; Wykosky, Jill; Furnari, Frank; Hoadley, Katherine A; Chin, Lynda; DePinho, Ronald A; Cavenee, Webster K; D'Andrea, Alan; Chen, Clark C

2010-05-24

Despite the critical role of Epidermal Growth Factor Receptor (EGFR) in glioblastoma pathogenesis, EGFR targeted therapies have achieved limited clinical efficacy. Here we propose an alternate therapeutic strategy based on the conceptual framework of non-oncogene addiction. A directed RNAi screen revealed that glioblastoma cells over-expressing EGFRvIII, an oncogenic variant of EGFR, become hyper-dependent on a variety of DNA repair genes. Among these, there was an enrichment of Base Excision Repair (BER) genes required for the repair of Reactive Oxygen Species (ROS)-induced DNA damage, including poly-ADP ribose polymerase 1 (PARP1). Subsequent studies revealed that EGFRvIII over-expression in glioblastoma cells caused increased levels of ROS, DNA strand break accumulation, and genome instability. In a panel of primary glioblastoma lines, sensitivity to PARP1 inhibition correlated with the levels of EGFR activation and oxidative stress. Gene expression analysis indicated that reduced expression of BER genes in glioblastomas with high EGFR expression correlated with improved patient survival. These observations suggest that oxidative stress secondary to EGFR hyper-activation necessitates increased cellular reliance on PARP1 mediated BER, and offer critical insights into clinical trial design.

Targeting EGFR induced oxidative stress by PARP1 inhibition in glioblastoma therapy.

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Masayuki Nitta

Full Text Available Despite the critical role of Epidermal Growth Factor Receptor (EGFR in glioblastoma pathogenesis, EGFR targeted therapies have achieved limited clinical efficacy. Here we propose an alternate therapeutic strategy based on the conceptual framework of non-oncogene addiction. A directed RNAi screen revealed that glioblastoma cells over-expressing EGFRvIII, an oncogenic variant of EGFR, become hyper-dependent on a variety of DNA repair genes. Among these, there was an enrichment of Base Excision Repair (BER genes required for the repair of Reactive Oxygen Species (ROS-induced DNA damage, including poly-ADP ribose polymerase 1 (PARP1. Subsequent studies revealed that EGFRvIII over-expression in glioblastoma cells caused increased levels of ROS, DNA strand break accumulation, and genome instability. In a panel of primary glioblastoma lines, sensitivity to PARP1 inhibition correlated with the levels of EGFR activation and oxidative stress. Gene expression analysis indicated that reduced expression of BER genes in glioblastomas with high EGFR expression correlated with improved patient survival. These observations suggest that oxidative stress secondary to EGFR hyper-activation necessitates increased cellular reliance on PARP1 mediated BER, and offer critical insights into clinical trial design.

Design, synthesis, and evaluation of VEGFR-targeted macromolecular MRI contrast agent based on biotin-avidin-specific binding.

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Liu, Yongjun; Wu, Xiaoyun; Sun, Xiaohe; Wang, Dan; Zhong, Ying; Jiang, Dandan; Wang, Tianqi; Yu, Dexin; Zhang, Na

2017-01-01

Developing magnetic resonance imaging (MRI) contrast agents with high relaxivity and specificity was essential to increase MRI diagnostic sensitivity and accuracy. In this study, the MRI contrast agent, vascular endothelial growth factor receptor (VEGFR)-targeted poly (l-lysine) (PLL)-diethylene triamine pentacetate acid (DTPA)-gadolinium (Gd) (VEGFR-targeted PLL-DTPA-Gd, VPDG), was designed and prepared to enhance the MRI diagnosis capacity of tumor. Biotin-PLL-DTPA-Gd was synthesized first, then, VEGFR antibody was linked to biotin-PLL-DTPA-Gd using biotin-avidin reaction. In vitro cytotoxicity study results showed that VPDG had low toxicity to MCF-7 cells and HepG2 cells at experimental concentrations. In cell uptake experiments, VPDG could significantly increase the internalization rates (61.75%±5.22%) in VEGFR-positive HepG2 cells compared to PLL-DTPA-Gd (PDG) (25.16%±4.71%, P contrast agent and held great potential for molecular diagnosis of tumor.

EGFR and Bcl-2 in gastric mucosa of children infected with Helicobacter pylori

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Ewa Ryszczuk

2016-03-01

Full Text Available Aim: The aim of the study was to evaluate the expression of EGFR and Bcl-2 proteins as inhibitory markers of apoptosis in surface epithelial cells and gland cells of antral gastric mucosa in children infected with Helicobacter pylori according to the severity and activity of antral gastritis and to assess the correlation between the number of cells expressing EGFR and the number of cells expressing Bcl-2 in H. pylori infected children.Materials and methods: The study included 44 children: 68.2% with chronic gastritis and positive IgG against H. pylori, and 31.8% with functional disorders of the gastrointestinal tract and with normal IgG against H. pylori. The evaluation of EGFR expression in gastric mucosa was performed immunohistochemically using monoclonal mouse anti-EGFR antibody. The polyclonal antibody was used to determine the expression of anti-Bcl-2.Results: A significant increase in the number of cells expressing EGFR and Bcl-2 protein was found in the epithelial cells in severe as well as mild and moderate gastritis in the group of children infected with H. pylori. An increase in the number of cells expressing EGFR and Bcl-2 protein was also found in the epithelial cells in group I according to the activity of gastritis. There was a statistically significant positive correlation between the numbers of cells expressing EGFR and Bcl-2 in H. pylori infected children.Conclusion: Increased expression of EGFR and Bcl-2 proteins in the epithelial cells and a statistically significant positive correlation between the numbers of cells expressing EGFR and Bcl-2 in H. pylori infected children could suggest increased regeneration abilities of gastric mucosa.

EGF-R is Expressed and AP-1 and NF-κ:B Are Activated in Stromal Myofibroblasts Surrounding Colon Adenocarcinomas Paralleling Expression of COX-2 and VEGF

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Panagiotis A. Konstantinopoulos

2007-01-01

Full Text Available Background: COX-2 and VEGF are important triggers of colon cancer growth, metastasis and angiogenesis. Cox-2 promoter contains transcriptional regulatory elements for AP-1 and NF-κ:B transcription factors whilst vegf is a known AP-1 downstream target gene. We investigated whether stromal myofibroblasts surrounding colon adenocarcinomas express COX-2 and VEGF and whether activation of AP-1 and NF-κ:B, as well as expression of EGF-R parallel expression of COX-2 and VEGF in these cells. Methods: Immunohistochemical methodology was performed on archival sections from 40 patients with colon adenocarcinomas. We evaluated c-FOS, p-c-JUN (phosphorylated c-JUN, p-Iκ:B-α (phosphorylated Iκ:B-α, EGF-R, COX-2, NF-κ:B and VEGF expression in stromal myofibroblasts surrounding colon adenocarcinomas. Double immunostaining with a-smooth muscle actin and each antibody was done to verify the expression of these molecules in stromal myofibroblasts. Results: VEGF, p-Iκ:B-α, NF-κ:B, c-FOS, p-c-JUN, EGF-R and COX-2 were expressed in stromal myofibroblasts surrounding colon adenocarcinomas in the majority of cases. EGF-R, p-Iκ:B-α, NF-κ:B, c-FOS and p-c-JUN correlated positively with COX-2 and VEGF expression. Conclusion: Stromal myofibroblasts surrounding colon adenocarcinomas are an important source of VEGF and COX-2 production, while AP-1 and NF-κ:B transcription factors are activated and EGF-R is expressed in these cells and associated with COX-2 and VEGF production.

Cell adhesion and EGFR activation regulate EphA2 expression in cancer

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Larsen, Alice Bjerregaard; Stockhausen, Marie-Thérése; Poulsen, Hans Skovgaard

2010-01-01

family kinases (SRC). Moreover, the results show that adhesion-induced EGFR activation and EphA2 expression is affected by interactions with extracellular matrix (ECM) proteins working as integrin ligands. Stimulation with the EphA2 ligand, ephrinA1 inhibited ERK phosphorylation and cancer cell viability...... largely unknown. Here we show that the expression of EphA2 in in vitro cultured cells, is restricted to cells growing adherently and that adhesion-induced EphA2 expression is dependent upon activation of the epidermal growth factor receptor (EGFR), mitogen activated protein kinase kinase (MEK) and Src...

Lead acetate induces EGFR activation upstream of SFK and PKCα linkage to the Ras/Raf-1/ERK signaling

International Nuclear Information System (INIS)

Wang, C.-Y.; Wang, Y.-T.; Tzeng, D.-W.; Yang, J.-L.

2009-01-01

Lead acetate (Pb), a probable human carcinogen, can activate protein kinase C (PKC) upstream of extracellular signal-regulated kinase 1 and 2 (ERK1/2). Yet, it remains unclear whether Pb activation of PKC → ERK1/2 involves receptor/non-receptor tyrosine kinases and the Ras signaling transducer. Here we demonstrate a novel mechanism elicited by Pb for transmitting ERK1/2 signaling in CL3 human non-small-cell lung adenocarcinoma cells. Pb induction of higher steady-state levels of Ras-GTP was essential for increasing phospho-Raf-1 S338 and phospho-ERK1/2. Pre-treatment of the cells with a conventional PKC inhibitor Goe6976 or depleting PKCα using specific small interfering RNA blocked Pb induction of Ras-GTP. Pb also activated cellular tyrosine kinases. Specific pharmacological inhibitors, PD153035 for epidermal growth factor receptor (EGFR) and SU6656 for Src family tyrosine kinases (SFK), but not AG1296 for platelet-derived growth factor receptor, could suppress the Pb-induced tyrosine kinases, PKCα, Ras-GTP, phospho-Raf-1 S338 and phospho-ERK1/2. Furthermore, phosphorylation of tyrosines on the EGFR multiple autophosphorylation sites and the conserved SFK autophosphorylation site occurred during exposure of cells to Pb for 1-5 min and 5-30 min, respectively. Intriguingly, Pb activation of EGFR required the intrinsic kinase activity but not dimerization of the receptor. Inhibition of SFK or PKCα activities did not affect EGFR phosphorylation, while knockdown of EGFR blocked SFK phosphorylation and PKCα activation following Pb. Together, these results indicate that immediate activation of EGFR in response to Pb is obligatory for activation of SFK and PKCα and subsequent the Ras-Raf-1-MKK1/2-ERK1/2 signaling cascade

NF-κB-dependent transcriptional upregulation of cyclin D1 exerts cytoprotection against hypoxic injury upon EGFR activation

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Chen, Zhi-Dong; Xu, Liang; Tang, Kan-Kai; Gong, Fang-Xiao; Liu, Jing-Quan; Ni, Yin; Jiang, Ling-Zhi; Hong, Jun; Han, Fang; Li, Qian; Yang, Xiang-Hong; Sun, Ren-Hua; Mo, Shi-Jing

2016-01-01

Apoptosis of neural cells is one of the main pathological features in hypoxic/ischemic brain injury. Nuclear factor-κB (NF-κB) might be a potential therapeutic target for hypoxic/ischemic brain injury since NF-κB has been found to be inactivated after hypoxia exposure, yet the underlying molecular mechanisms of NF-κB inactivation are largely unknown. Here we report that epidermal growth factor receptor (EGFR) activation prevents neuron-like PC12 cells apoptosis in response to hypoxia via restoring NF-κB-dependent transcriptional upregulation of cyclin D1. Functionally, EGFR activation by EGF stimulation mitigates hypoxia-induced PC12 cells apoptosis in both dose- and time-dependent manner. Of note, EGFR activation elevates IKKβ phosphorylation, increases IκBα ubiquitination, promotes P65 nuclear translocation and recruitment at cyclin D1 gene promoter as well as upregulates cyclin D1 expression. EGFR activation also abrogates the decrease of IKKβ phosphorylation, reduction of IκBα ubiquitination, blockade of P65 nuclear translocation and recruitment at cyclin D1 gene promoter as well as downregulation of cyclin D1 expression induced by hypoxia. Furthermore, NF-κB-dependent upregulation of cyclin D1 is instrumental for the EGFR-mediated cytoprotection against hypoxic apoptosis. In addition, the dephosphorylation of EGFR induced by either EGF siRNA transfection or anti-HB-EGF neutralization antibody treatment enhances hypoxic cytotoxicity, which are attenuated by EGF administration. Our results highlight the essential role of NF-κB-dependent transcriptional upregulation of cyclin D1 in EGFR-mediated cytoprotective effects under hypoxic preconditioning and support further investigation of EGF in clinical trials of patients with hypoxic/ischemic brain injury. - Highlights: • EGFR activation significantly decreases hypoxia-induced PC12 cells injury. • EGFR activation abrogates the transcriptional repression of cyclin D1 induced by hypoxia in a NF

NF-κB-dependent transcriptional upregulation of cyclin D1 exerts cytoprotection against hypoxic injury upon EGFR activation

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Chen, Zhi-Dong [Department of Critical Care Medicine, The First Affiliated Hospital of Huzhou Normal College, Huzhou 313000, Zhejiang (China); Xu, Liang [Department of Critical Care Medicine, Zhejiang Provincial People’s Hospital, Hangzhou 310000, Zhejiang (China); Tang, Kan-Kai [Department of Critical Care Medicine, The First Affiliated Hospital of Huzhou Normal College, Huzhou 313000, Zhejiang (China); Gong, Fang-Xiao; Liu, Jing-Quan; Ni, Yin; Jiang, Ling-Zhi; Hong, Jun; Han, Fang; Li, Qian; Yang, Xiang-Hong [Department of Critical Care Medicine, Zhejiang Provincial People’s Hospital, Hangzhou 310000, Zhejiang (China); Sun, Ren-Hua, E-mail: jqin168@hotmail.com [Department of Critical Care Medicine, Zhejiang Provincial People’s Hospital, Hangzhou 310000, Zhejiang (China); Mo, Shi-Jing, E-mail: msj860307@163.com [Department of Critical Care Medicine, Zhejiang Provincial People’s Hospital, Hangzhou 310000, Zhejiang (China)

2016-09-10

Apoptosis of neural cells is one of the main pathological features in hypoxic/ischemic brain injury. Nuclear factor-κB (NF-κB) might be a potential therapeutic target for hypoxic/ischemic brain injury since NF-κB has been found to be inactivated after hypoxia exposure, yet the underlying molecular mechanisms of NF-κB inactivation are largely unknown. Here we report that epidermal growth factor receptor (EGFR) activation prevents neuron-like PC12 cells apoptosis in response to hypoxia via restoring NF-κB-dependent transcriptional upregulation of cyclin D1. Functionally, EGFR activation by EGF stimulation mitigates hypoxia-induced PC12 cells apoptosis in both dose- and time-dependent manner. Of note, EGFR activation elevates IKKβ phosphorylation, increases IκBα ubiquitination, promotes P65 nuclear translocation and recruitment at cyclin D1 gene promoter as well as upregulates cyclin D1 expression. EGFR activation also abrogates the decrease of IKKβ phosphorylation, reduction of IκBα ubiquitination, blockade of P65 nuclear translocation and recruitment at cyclin D1 gene promoter as well as downregulation of cyclin D1 expression induced by hypoxia. Furthermore, NF-κB-dependent upregulation of cyclin D1 is instrumental for the EGFR-mediated cytoprotection against hypoxic apoptosis. In addition, the dephosphorylation of EGFR induced by either EGF siRNA transfection or anti-HB-EGF neutralization antibody treatment enhances hypoxic cytotoxicity, which are attenuated by EGF administration. Our results highlight the essential role of NF-κB-dependent transcriptional upregulation of cyclin D1 in EGFR-mediated cytoprotective effects under hypoxic preconditioning and support further investigation of EGF in clinical trials of patients with hypoxic/ischemic brain injury. - Highlights: • EGFR activation significantly decreases hypoxia-induced PC12 cells injury. • EGFR activation abrogates the transcriptional repression of cyclin D1 induced by hypoxia in a NF

Monitoring of high-density lipoprotein cholesterol level is predictive of EGFR mutation and efficacy of EGFR-TKI in patients with advanced lung adenocarcinoma

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Lv Y

2016-01-01

Full Text Available Yang Lv,1,2 Li-Yun Miao,2 Qiu-Fang Chen,1 Yan Li,2 Zhi-Xiang Shi,1 Xuan-Sheng Ding1 1Department of Clinical Pharmacy, China Pharmaceutical University, Nanjing, Jiangsu, People’s Republic of China; 2Division of Respiratory Medicine, Department of Respiration, The Affiliated Drum Tower Hospital of Nanjing University Medical College, Nanjing University Medical School, Nanjing, Jiangsu, People’s Republic of China Abstract: High-density lipoprotein cholesterol (HDL-C has an inverse association with the incidence of lung cancer. However, whether it can be used as a predictive factor in advanced lung adenocarcinoma patients treated with epidermal growth factor receptor (EGFR tyrosine kinase inhibitors (TKI still remains undefined. This research aimed at studying the relationship of serum HDL-C baseline level and HDL-C kinetics to EGFR mutation, the efficacy of EGFR-TKI, and the predictive value of PFS. The presence of mutation rate in the 192 patients with lung adenocarcinoma was compared within stratified groups. Levels of baseline HDL-C and kinetics of HDL-C were analyzed retrospectively in patients treated with EGFR-TKI harboring EGFR mutation. Univariate and multivariate analyses were performed to investigate the prognostic value of HDL-C. EGFR mutation rate of HDL-C high-level group was significantly higher than that of low-level group (59.0% vs 35.6%, P=0.001. Multivariate logistic analysis showed that high-level HDL-C was an independent predictive factor for EGFR gene mutation (P=0.005; odds ratio =0.417; 95% confidence interval [CI], 0.227–0.768. Patients with a low level of HDL-C before therapy showed a progression of disease in most cases (P<0.001. According to HDL-C kinetics, patients who received EGFR-TKI treatment harboring EGFR mutation were divided into four groups. Univariate analysis showed that patients in nondecreased group had longer progression-free survival (P<0.001; hazard ratio =0.003; 95% CI, 0.001–0.018. Multivariate

The Anticancer Effects of Radachlorin-mediated Photodynamic Therapy in the Human Endometrial Adenocarcinoma Cell Line HEC-1-A.

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Kim, Su-Mi; Rhee, Yun-Hee; Kim, Jong-Soo

2017-11-01

We investigated the effect of photodynamic therapy (PDT) using radachlorin on invasion, vascular formation and apoptosis by targeting epidermal growth factor receptor (EGFR)/vascular endothelial growth factor receptor 2 (VEGFR2) signaling pathways in the HEC-1-A endometrial adenocarcinoma cell line. To investigate the apoptotic pathway, we performed the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) assay, and western blot analysis. We also evaluated the effects of PDT on tubular capillary formation in and invasion by HEC-1-A cells with a tube formation assay, invasion assay, prostaglandin E2 (PGE2) assay, and western blot analysis. PDT had anticancer effects on HEC-1-A through activation of the intrinsic pathway of apoptosis via caspase-9 and poly-(ADP-ribose) polymerase (PARP). PDT also inhibited tubular capillary formation in and invasion by HEC-1-A under VEGF pretreatment, that resulted from down-regulation of VEGFR2, EGFR, Ras homolog gene family/ member A (RhoA) and PGE2. These results are indicative of the specificity of radachlorin-mediated PDT to VEGF. The major advantage of radachlorin-mediated PDT is its selectivity for cancer tissue while maintaining adjacent normal endometrial tissue. Therefore, radachlorin-mediated PDT might offer high anticancer efficacy for endometrial adenocarcinoma and an especially useful modality for preserving fertility. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

Clinical significance of altered nm23-H1, EGFR, RB and p53 expression in bilharzial bladder cancer

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Khaled, Hussein M; Bahnassy, Abeer A; Raafat, Amira A; Zekri, Abdel-Rahman N; Madboul, Maha S; Mokhtar, Nadia M

2009-01-01

Clinical characterization of bladder carcinomas is still inadequate using the standard clinico-pathological prognostic markers. We assessed the correlation between nm23-H1, Rb, EGFR and p53 in relation to the clinical outcome of patients with muscle invasive bilharzial bladder cancer (MI-BBC). nm23-H1, Rb, EGFR and p53 expression was assessed in 59 MI-BBC patients using immunohistochemistry and reverse transcription (RT-PCR) and was correlated to the standard clinico-pathological prognostic factors, patient's outcome and the overall survival (OS) rate. Overexpression of EGFR and p53 proteins was detected in 66.1% and 35.6%; respectively. Loss of nm23-H1and Rb proteins was detected in 42.4% and 57.6%; respectively. Increased EGFR and loss of nm23-H1 RNA were detected in 61.5% and 36.5%; respectively. There was a statistically significant correlation between p53 and EGFR overexpression (p < 0.0001), nm23 loss (protein and RNA), lymph node status (p < 0.0001); between the incidence of local recurrence and EGFR RNA overexpression (p= 0.003) as well as between the incidence of metastasis and altered Rb expression (p = 0.026), p53 overexpression (p < 0.0001) and mutation (p = 0.04). Advanced disease stage correlated significantly with increased EGFR (protein and RNA) (p = 0.003 & 0.01), reduced nm23-H1 RNA (p = 0.02), altered Rb (p = 0.023), and p53 overexpression (p = 0.004). OS rates correlated significantly, in univariate analysis, with p53 overexpression (p = 0.011), increased EGFR (protein and RNA, p = 0.034&0.031), nm23-H1 RNA loss (p = 0.021) and aberrations of ≥ 2 genes. However, multivariate analysis showed that only high EGFR overexpression, metastatic recurrence, high tumor grade and the combination of ≥ 2 affected markers were independent prognostic factors. nm23-H1, EGFR and p53 could be used as prognostic biomarkers in MI-BBC patients. In addition to the standard pathological prognostic factors, a combination of these markers (≥ 2) has

Gli1-Mediated Regulation of Sox2 Facilitates Self-Renewal of Stem-Like Cells and Confers Resistance to EGFR Inhibitors in Non-Small Cell Lung Cancer.

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Bora-Singhal, Namrata; Perumal, Deepak; Nguyen, Jonathan; Chellappan, Srikumar

2015-07-01

Non-small cell lung cancer (NSCLC) patients have very low survival rates because the current therapeutic strategies are not fully effective. Although EGFR tyrosine kinase inhibitors are effective for NSCLC patients harboring EGFR mutations, patients invariably develop resistance to these agents. Alterations in multiple signaling cascades have been associated with the development of resistance to EGFR inhibitors. Sonic Hedgehog and associated Gli transcription factors play a major role in embryonic development and have recently been found to be reactivated in NSCLC, and elevated Gli1 levels correlate with poor prognosis. The Hedgehog pathway has been implicated in the functions of cancer stem cells, although the underlying molecular mechanisms are not clear. In this context, we demonstrate that Gli1 is a strong regulator of embryonic stem cell transcription factor Sox2. Depletion of Gli1 or inhibition of the Hedgehog signaling significantly abrogated the self-renewal of stem-like side-population cells from NSCLCs as well as vascular mimicry of such cells. Gli1 was found to transcriptionally regulate Sox2 through its promoter region, and Gli1 could be detected on the Sox2 promoter. Inhibition of Hedgehog signaling appeared to work cooperatively with EGFR inhibitors in markedly reducing the viability of NSCLC cells as well as the self-renewal of stem-like cells. Thus, our study demonstrates a cooperative functioning of the EGFR signaling and Hedgehog pathways in governing the stem-like functions of NSCLC cancer stem cells and presents a novel therapeutic strategy to combat NSCLC harboring EGFR mutations. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Genetic Polymorphisms in the EGFR (R521K and Estrogen Receptor (T594T Genes, EGFR and ErbB-2 Protein Expression, and Breast Cancer Risk in Tunisia

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Imen Kallel

2009-01-01

Full Text Available We evaluated the association of epidermal growth factor receptor (EGFR 142285G>A (R521K and estrogen receptor alpha (ESR1 2014G>A (T594T single nucleotide polymorphisms with breast cancer risk and prognosis in Tunisian patients. EGFR 142285G>A and ESR1 2014G>A were genotyped in a sample of 148 Tunisian breast cancer patients and 303 controls using PCR-RFLP method. Immunohistochemitsry was used to evaluate the expression levels of EGFR, HER2, ESR1, progesterone receptor and BCL2 in tumors. We found no evidence for an association between EGFR R521K polymorphism and breast cancer risk. However, we found that the homozygous GG (Arg genotype was more prevalent in patients with lymph node metastasis (=.03 and high grade tumors (=.011. The ESR1 2014G allele showed significant association with breast cancer risk (=.025. The GG genotype was associated with HER2 overexpression and this association withstood univariate and multivariate analyses (=.009; =.021, resp.. These data suggest that the R521K might be a prognostic factor, because it correlates with both tumor grade and nodule status. The higher expression of HER2 in ESR1 T594T GG patients suggests the possibility that ESR1 gene polymorphisms accompanied by HER2 expression might influence the pathogenesis of breast cancers.

EPIDERMAL GROWTH FACTOR RECEPTOR (EGFR AND HUMAN PAPILLOMAVIRUS (HPV L1 CAPSID PROTEIN IN CERVICAL SQUAMOUS INTRAEPITHELIAL LESIONS

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Balan Raluca

2010-09-01

Full Text Available We analyzed the immunohistochemical pattern of epidermal growth factor receptor (EGFR in cervical squamous intraepithelial lesions (SILs in correlation with L1 HPV capsid protein, in order to determine the relationship between EGFR expression and the infection status of human papillomavirus (HPV. The study included 40 cases, 24 LSIL (low grade SIL (CIN1, cervical intraepithelial neoplasia and 16 HSIL (high grade SIL (6 cases of CIN2 and 10 cases of CIN3. The immunoexpression of L1 HPV protein was assessed on conventional cervico-vaginal smears and EGFR was immunohistochemically evaluated on the corresponding cervical biopsies. The HPV L1 capsid protein was expressed in 45.83% of LSIL and 25% of HSIL. EGFR was overexpressed in 62,4% of HSIL (58,4% CIN2 and 41,6% CIN3 and 37,6% LSIL. The immunoexpression of L1 HPV has clinical application in the progression assessment of the cervical precancerous lesions without a correlation to the grade of the cervical SIL. EGFR is expressed by all proliferating squamous epithelial cells, thus corresponding with the grade of SIL. The evaluation of EGFR status, correlated with L1 HPV protein expression, can provide useful data of progression risk of cervical squamous intraepithelial lesions

Tyrosine kinase inhibitors directed against the vascular endothelial growth factor receptor (VEGFR) have distinct cutaneous toxicity profiles: a meta-analysis and review of the literature.

Science.gov (United States)

Massey, Paul R; Okman, Jonathan S; Wilkerson, Julia; Cowen, Edward W

2015-06-01

Inhibition of the vascular endothelial growth factor receptor (VEGFR) with tyrosine kinase inhibitors (TKIs) is associated with cutaneous adverse effects that increase patient morbidity. Our objective was to examine the skin toxicity profile of anti-VEGFR TKIs and determine the changing incidence in clinical trials. PubMed was queried for phase II or III trials of anti-VEGFR TKIs between 2000 and 2013 involving ≥50 patients. Adverse events were abstracted, with results presented in both fixed and random effects models. Odds ratios (OR) and 95 % confidence intervals (CIs) were estimated for studies with at least two arms. Across 82 included studies, all grades rash (OR, 2.68; 95 % CI, 2.45-2.94), hand-foot skin reaction (HFSR) (OR, 2.70; 95 % CI, 2.43-3.00), and pruritus (OR, 1.25; 95 % CI, 1.12-1.39) were associated with anti-VEGFR TKIs. Vandetanib had the highest incidence of rash (41 %), while sorafenib was most commonly associated with HFSR (37 %) and pruritus (14 %). The incidence of HFSR from 2000 to 2013 showed an upward trend (r (2) = 0.042, p = 0.10) and in sunitinib therapy increased significantly (r (2) = 0.237, p = 0.04). The incidence of HFSR, rash, and pruritus varies considerably by drug. Our data suggest a continued need to address skin toxicities and improve reporting strategies.

Cadmium induces matrix metalloproteinase-9 expression via ROS-dependent EGFR, NF-kB, and AP-1 pathways in human endothelial cells

International Nuclear Information System (INIS)

Lian, Sen; Xia, Yong; Khoi, Pham Ngoc; Ung, Trong Thuan; Yoon, Hyun Joong; Kim, Nam Ho; Kim, Kyung Keun; Jung, Young Do

2015-01-01

Highlights: • Cadmium induces MMP-9 expression through NADPH oxidase-derived ROS. • Cadmium induces MMP-9 through EGFR-mediated Akt, Erk1/2 and JNK1/2 signaling pathways. • Akt, MAPKs (Erk1/2 and JNK1/2) functioned as upstream signals of NF-kB and AP-1 respectively, in cadmium-induced MMP-9 in endothelial cells. • ROS production by NADPH oxidase is the furthest upstream signal in MMP-9 expression in ECV304 cells. - Abstract: Cadmium (Cd), a widespread cumulative pollutant, is a known human carcinogen, associated with inflammation and tumors. Matrix metalloproteinase-9 (MMP-9) plays a pivotal role in tumor metastasis; however, the mechanisms underlying the MMP-9 expression induced by Cd remain obscure in human endothelial cells. Here, Cd elevated MMP-9 expression in dose- and time-dependent manners in human endothelial cells. Cd increased ROS production and the ROS-producing NADPH oxidase. Cd translocates p47 phox , a key subunit of NADPH oxidase, to the cell membrane. Cd also activated the phosphorylation of EGFR, Akt, Erk1/2, and JNK1/2 in addition to promoting NF-kB and AP-1 binding activities. Specific inhibitor and mutagenesis studies showed that EGFR, Akt, Erk1/2, JNK1/2 and transcription factors NF-κB and AP-1 were related to Cd-induced MMP-9 expression in endothelial cells. Akt, Erk1/2, and JNK1/2 functioned as upstream signals in the activation of NF-κB and AP-1, respectively. In addition, N-acetyl-L-cystein (NAC), diphenyleneiodonium chloride (DPI) and apocynin (APO) inhibited the Cd-induced activation of EGFR, Akt, Erk1/2, JNK1/2, and p38 MAPK, indicating that ROS production by NADPH oxidase is the furthest upstream signal in MMP-9 expression. At present, it states that Cd displayed marked invasiveness in ECV304 cells, which was partially abrogated by MMP-9 neutralizing antibodies. These results demonstrated that Cd induces MMP-9 expression via ROS-dependent EGFR- > Erk1/2, JNK1/2- > AP-1 and EGFR- > Akt- > NF-κB signaling pathways and, in turn

VEGFR-3 Expression in Oral Lichen Planus

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Zolfaghari Saravi, Zahra; Seyedmajidi, Maryam; Sharbatdaran, Majid; Bijani, Ali; Mozaffari, Fatemeh; Aminishakib, Pouyan

2017-02-01

Background and objective: Given the postulated the role of inflammation and possible contribution of lymphangiogenesis in oral lichen planus, this study aimed to assess any associated presence of VEGFR-3. Material and Methods: This cross-sectional study was performed on 52 formalin fixed and paraffin embedded blocks of oral lichen planus (pathological diagnosis based on Modified WHO criteria), comprising 25 of erosive and 27 of reticular type, along with 60 samples of normal mucosa (with minimal inflammation from clinical and histopathological aspects) obtained at crown lengthening surgery. Four micron sections were cut from paraffin blocks and stained with H and E for confirmation of diagnosis and by immunohistochemistry with primary antibodies against VEGFR-3. Negative controls were provided by omission of primary antibody and placenta was considered as a positive control. Data were analyzed by Chi-square, Mann-Whitney and Kruskal-wallis tests and P lichen planus specimens and 5% of those from normal mucosa (poral lichen planus than in normal mucosa (poral lichen planus (p=0.262) and the average number of stained vessels (p=0.092) demonstrated no significant difference according to the type. Conclusion: It appears that VEGFR-3 expression might be involved in the pathogenesis of the oral lichen planus through increasing lymphatic vessels and lymphangiogenesis. Creative Commons Attribution License

PAI-1 and EGFR expression in adult glioma tumors: toward a molecular prognostic classification

International Nuclear Information System (INIS)

Muracciole, Xavier; Romain, Sylvie; Dufour, Henri; Palmari, Jacqueline; Chinot, Olivier; Ouafik, L'Houcine; Grisoli, Francois; Figarella-Branger, Dominique; Martin, Pierre-Marie

2002-01-01

Purpose: Molecular classification of gliomas is a major challenge in the effort to improve therapeutic decisions. The plasminogen activator system, including plasminogen activator inhibitor type 1 (PAI-1), plays a key role in tumor invasion and neoangiogenesis. Epidermal growth factor receptor (EGFR) is involved in the control of proliferation. The contribution of PAI-1 and EGFR to the survival of gliomas was retrospectively investigated. Methods and Materials: Fifty-nine adult gliomas treated by neurosurgery and conventional irradiation were analyzed, including 9 low-grade (2) and 50 high-grade (3-4) tumors (WHO classification). PAI-1 was measured on cytosols and EGFR on solubilized membranes using ELISA methods. Results: High PAI-1 levels were strongly associated with high histologic grade (p<0.001) and histologic necrosis (p<0.001). PAI-1 also correlated positively with patient age (p=0.05) and negatively with Karnofsky index (p=0.01). By univariate analysis of the high-grade population, higher PAI-1 (p<0.0001) and EGFR values (p=0.02) were associated with shorter overall survival. Only PAI-1 was an independent factor in multivariate analysis. Grade 3 tumors with low PAI-1 (100% 3-year overall survival rate) presented the same clinical outcome as the low-grade tumors. Conclusions: In this prognostic study, PAI-1 and EGFR expression revealed similarities and differences between high-grade gliomas that were not apparent by traditional clinical criteria. These data strongly support that biologic factors should be included in glioma classification and the design of clinical trials to treat more homogeneous populations

Reciprocal regulation of annexin A2 and EGFR with Her-2 in Her-2 negative and herceptin-resistant breast cancer.

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Praveenkumar K Shetty

Full Text Available Alternative survival pathways are commonly seen to be upregulated upon inhibition of receptor tyrosine kinases (RTK, including Her-2. It is established that treatment with Herceptin leads to selective overexpression and activation of epidermal growth factor receptor (EGFR and Src which further contributes to oncogenesis in Herceptin resistant and triple negative breast cancer (TNBC patients. Here, we show a co-regulated upregulation in the expression of Annexin A2 (AnxA2, a known substrate of Src and one of the regulators of EGFR receptor endocytosis, in Herceptin resistant and Her-2 negative breast cancer. Immunohistochemical expression analysis revealed a reciprocal regulation between Her-2 and AnxA2 in breast cancer clinical samples as well as in cell lines as confirmed by protein and RNA analysis. The siRNA and Herceptin mediated downregulation/inhibition of Her-2 in Her-2 amplified cells induced AnxA2 expression and membrane translocation. In this study we report a possible involvement of AnxA2 in maintaining constitutively activated EGFR downstream signaling intermediates and hence in cell proliferation, migration and viability. This effect was consistent in Herceptin resistant JIMT-1 cells as well as in Her-2 negative breast cancer. The siRNA mediated AnxA2 downregulation leads to increased apoptosis, decreased cell viability and migration. Our studies further indicate the role of AnxA2 in EGFR-Src membrane bound signaling complex and ligand induced activation of downstream signaling pathways. Targeting this AnxA2 dependent positive regulation of EGFR signaling cascade may be of therapeutic value in Her-2 negative breast cancer.

Uncommon EGFR mutations in cytological specimens of 1,874 newly diagnosed Indonesian lung cancer patients

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Syahruddin, Elisna; Wulandari, Laksmi; Sri Muktiati, Nunuk; Rima, Ana; Soeroso, Noni; Ermayanti, Sabrina; Levi, Michael; Hidajat, Heriawaty; Widjajahakim, Grace; Utomo, Ahmad Rusdan Handoyo

2018-01-01

Purpose We aimed to evaluate the distribution of individual epidermal growth factor receptor (EGFR) mutation subtypes found in routine cytological specimens. Patients and methods A retrospective audit was performed on EGFR testing results of 1,874 consecutive cytological samples of newly diagnosed or treatment-naïve Indonesian lung cancer patients (years 2015–2016). Testing was performed by ISO15189 accredited central laboratory. Results Overall test failure rate was 5.1%, with the highest failure (7.1%) observed in pleural effusion and lowest (1.6%) in needle aspiration samples. EGFR mutation frequency was 44.4%. Tyrosine kinase inhibitor (TKI)-sensitive common EGFR mutations (ins/dels exon 19, L858R) and uncommon mutations (G719X, T790M, L861Q) contributed 57.1% and 29%, respectively. Approximately 13.9% of mutation-positive patients carried a mixture of common and uncommon mutations. Women had higher EGFR mutation rate (52.9%) vs men (39.1%; pcytological techniques yielded similar success rate to detect EGFR mutations. Uncommon EGFR mutations were frequent events in Indonesian lung cancer patients. PMID:29615847

EGFR and HER2 expression in primary cervical cancers and corresponding lymph node metastases: Implications for targeted radiotherapy

International Nuclear Information System (INIS)

Shen, Li; Shui, Yongjie; Wang, Xiaojia; Sheng, Liming; Yang, Zhengyan; Xue, Danfeng; Wei, Qichun

2008-01-01

Proteins overexpressed on the surface of tumor cells can be selectively targeted. Epidermal growth factor receptor (EGFR) and human epidermal growth factor receptor 2 (HER2) are among the most often targeted proteins. The level and stability of expression in both primary tumors and corresponding metastases is crucial in the assessment of a receptor as target for imaging in nuclear medicine and for various forms of therapy. So far, the expression of EGFR and HER2 has only been determined in primary cervical cancers, and we have not found published data regarding the receptor status in corresponding metastatic lesions. The goal of this study was to evaluate whether any of these receptors are suitable as target for clinical diagnosis and therapy. Expression of EGFR and HER2 was investigated immunohistochemically in both lymph node metastases and corresponding primary cervical cancers (n = 53). HER2 and EGFR expression was scored using HercepTest criteria (0, 1+, 2+ or 3+). EGFR overexpression (2+ or 3+) was found in 64% (35/53) of the primary cervical tumors and 60% (32/53) of the corresponding lymph node metastases. There was a good concordance between the primary tumors and the paired metastases regarding EGFR expression. Only four patients who had 2+ or 3+ in the primary tumors changed to 0 or 1+ in lymph node metastases, and another two cases changed the other way around. None of the primary tumors or the lymph node metastases expressed HER2 protein. The EGFR expression seems to be common and stable during cervical cancer metastasis, which is encouraging for testing of EGFR targeted radiotherapy. HER2 appears to be of poor interest as a potential target in the treatment of cervical cancer

Biological variations in plasma VEGF and VEGFR-1 may compromise their biomarker value in colorectal cancer

DEFF Research Database (Denmark)

Svendsen, Mads N.; Brunner, Nils; Christensen, Ib Jarle

2010-01-01

Vascular Endothelial Growth Factor (VEGF) plays a prominent role in tumor angiogenesis and plasma VEGF concentration may carry prognostic information in colorectal cancer. The VEGF receptor 1 (VEGFR-1) is a regulatory receptor which is shredded into plasma of patients with colorectal cancer. For ....... For both molecules, large biological variation and lack of standardization of assay procedures are major challenges....

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. © 2015 Authors; published by Portland Press Limited.

Study on the proliferation of human gastric cancer cell AGS by activation of EGFR in H2O2.

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Wang, Q; Shen, W; Tao, G-Q; Sun, J; Shi, L-P

2017-03-01

This study is to investigate the effect of low concentration hydrogen peroxide (H2O2) on the proliferation of gastric cancer AGS cell line in vitro and the mechanism. AGS cells were treated with different low concentrations of H2O2 (1, 0.1, 0.01, and 0.001 μm) for 48 hours. The effect of H2O2 concentration gradient on the activity of AGS cell activities was detected by methyl thiazolyl tetrazolium (MTT) method. The expression of the epidermal growth factor receptor (EGFR) and its downstream signaling pathway extracellular signal-regulated kinase (ERK) protein in H2O2 was detected by Western blot method; moreover, the effect of H2O2 on intracellular reactive oxygen species (ROS) in AGS cells was observed under the fluorescence microscope and quantitative analysis by flow cytometry. The effect of H2O2 on the level of c-myc mRNA in AGS cells was also detected by reverse transcription polymerase chain reaction (RT-PCR). MTT detection results showed that 1 μm and 0.1 μm H2O2 at 48h can effectively promote the proliferation of AGS cells (pH2O2 treatment of AGS cells, the EGFR protein levels and ERK protein phosphorylation levels increased significantly (pH2O2 increased the intracellular reactive oxygen species (ROS). RT-PCR results showed the levels of c-myc mRNA in AGS cells treated with a low concentration of H2O2 were significantly increased (pH2O2 can significantly promote the proliferation of AGS cells by activating EGFR/ERK signaling pathway.

Areca nut components affect COX-2, cyclin B1/cdc25C and keratin expression, PGE2 production in keratinocyte is related to reactive oxygen species, CYP1A1, Src, EGFR and Ras signaling.

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Mei-Chi Chang

Full Text Available Chewing of betel quid (BQ increases the risk of oral cancer and oral submucous fibrosis (OSF, possibly by BQ-induced toxicity and induction of inflammatory response in oral mucosa.Primary gingival keratinocytes (GK cells were exposed to areca nut (AN components with/without inhibitors. Cytotoxicity was measured by 3-(4,5-dimethyl- thiazol- 2-yl-2,5-diphenyl-tetrazolium bromide (MTT assay. mRNA and protein expression was evaluated by reverse transcriptase-polymerase chain reaction (RT-PCR and western blotting. PGE2/PGF2α production was measured by enzyme-linked immunosorbent assays.Areca nut extract (ANE stimulated PGE2/PGF2α production, and upregulated the expression of cyclooxygenase-2 (COX-2, cytochrome P450 1A1 (CYP1A1 and hemeoxygenase-1 (HO-1, but inhibited expression of keratin 5/14, cyclinB1 and cdc25C in GK cells. ANE also activated epidermal growth factor receptor (EGFR, Src and Ras signaling pathways. ANE-induced COX-2, keratin 5, keratin 14 and cdc25C expression as well as PGE2 production were differentially regulated by α-naphthoflavone (a CYP 1A1/1A2 inhibitor, PD153035 (EGFR inhibitor, pp2 (Src inhibitor, and manumycin A (a Ras inhibitor. ANE-induced PGE2 production was suppressed by piper betle leaf (PBL extract and hydroxychavicol (two major BQ components, dicoumarol (aQuinone Oxidoreductase--NQO1 inhibitor and curcumin. ANE-induced cytotoxicity was inhibited by catalase and enhanced by dicoumarol, suggesting that AN components may contribute to the pathogenesis of OSF and oral cancer via induction of aberrant differentiation, cytotoxicity, COX-2 expression, and PGE2/PGF2α production.CYP4501A1, reactive oxygen species (ROS, EGFR, Src and Ras signaling pathways could all play a role in ANE-induced pathogenesis of oral cancer. Addition of PBL into BQ and curcumin consumption could inhibit the ANE-induced inflammatory response.

The Predictive and Prognostic Significance of c-erb-B2, EGFR, PTEN, mTOR, PI3K, p27, and ERCC1 Expression in Hepatocellular Carcinoma

Science.gov (United States)

Bassullu, Nuray; Turkmen, Ilknur; Dayangac, Murat; Yagiz Korkmaz, Pinar; Yasar, Reyhan; Akyildiz, Murat; Yaprak, Onur; Tokat, Yaman; Yuzer, Yildiray; Bulbul Dogusoy, Gulen

2012-01-01

Background Hepatocellular carcinoma (HCC) is the fifth most common fatal cancer and an important healthcare problem worldwide. There are many studies describing the prognostic and predictive effects of epidermal growth factor receptor 2 (c-erb-B2) and epidermal growth factor receptor 1 (EGFR), transmembrane tyrosine kinases that influence cell growth and proliferation in many tumors. Objectives The current study aimed to investigate the expression levels of c-erb-B2, EGFR, PTEN, mTOR, PI3K, p27, and ERCC1 in hepatocellular carcinoma (HCC) and their correlation with other clinicopathologic features. Patients and Methods Fifty HCC cases were stained immunohistochemically with these markers. Correlations between the markers and clinicopathologic characteristics and survival rates were analyzed. Results No membranous c-erb-B2 staining was seen, whereas cytoplasmic positivity was present in 92% of HCC samples, membranous EGFR was observed in 40%, PI3K was found in all samples, and mTOR was seen in 30%, whereas reduced or absent PTEN expression was observed in 56% of samples and loss of p27 was seen in 92% of the cases. c-erb-B2 and mTOR overexpression, as well as reduced expression of p27, all correlated with multiple tumors (P = 0.041, P < 0.001, and P < 0.001, respectively). P27 loss, and mTOR and EGFR positivity were significantly correlated with AFP (P = 0.047, P = 0.004, and P = 0.008, respectively). Angiolymphatic invasion was more commonly seen in EGFR- and ERCC1-positive cases (P = 0.003 and P = 0.005). EGFR was also correlated with histological grade (P = 0.039). No significant correlations were found among PTEN , PI3K, and the clinicopathological parameters. Disease-free or overall survival rates showed significant differences among therapy modalities, AFP levels, angiolymphatic or lymph node invasions, and ERCC1 and p27 expression levels (P < 0.05). Conclusions c-erb-B2, EGFR, mTOR, ERCC1 overexpression levels, and loss of p27 may play roles in

Anti-HER2 antibody and ScFvEGFR-conjugated antifouling magnetic iron oxide nanoparticles for targeting and magnetic resonance imaging of breast cancer

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Chen H

2013-10-01

Full Text Available Hongwei Chen,1,* Liya Wang,1,2,* Qiqi Yu,1,2 Weiping Qian,3 Diana Tiwari,1 Hong Yi,4 Andrew Y Wang,5 Jing Huang,1,2 Lily Yang,3 Hui Mao1,2 1Department of Radiology and Imaging Sciences, 2Center for Systems Imaging, 3Department of Surgery, Emory University School of Medicine, 4Robert Apkarian Electron Microscopy Core, Emory University, Atlanta, GA, 5Ocean NanoTech LLC, Springdale, AK, USA *These authors contributed equally to this work Abstract: Antifouling magnetic iron oxide nanoparticles (IONPs coated with block copolymer poly(ethylene oxide-block-poly(γ-methacryloxypropyltrimethoxysilane (PEO-b-PγMPS were investigated for improving cell targeting by reducing nonspecific uptake. Conjugation of a HER2 antibody, Herceptin®, or a single chain fragment (ScFv of antibody against epidermal growth factor receptor (ScFvEGFR to PEO-b-PγMPS-coated IONPs resulted in HER2-targeted or EGFR-targeted IONPs (anti-HER2-IONPs or ScFvEGFR-IONPs. The anti-HER2-IONPs bound specifically to SK-BR-3, a HER2-overexpressing breast cancer cell line, but not to MDA-MB-231, a HER2-underexpressing cell line. On the other hand, the ScFvEGFR-IONPs showed strong reactivity with MDA-MB-231, an EGFR-positive human breast cancer cell line, but not with MDA-MB-453, an EGFR-negative human breast cancer cell line. Transmission electron microscopy revealed internalization of the receptor-targeted nanoparticles by the targeted cancer cells. In addition, both antibody-conjugated and non-antibody-conjugated IONPs showed reduced nonspecific uptake by RAW264.7 mouse macrophages in vitro. The developed IONPs showed a long blood circulation time (serum half-life 11.6 hours in mice and low accumulation in both the liver and spleen. At 24 hours after systemic administration of ScFvEGFR-IONPs into mice bearing EGFR-positive breast cancer 4T1 mouse mammary tumors, magnetic resonance imaging revealed signal reduction in the tumor as a result of the accumulation of the targeted IONPs

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

Clinical efficacy of first-generation EGFR-TKIs in patients with advanced non-small-cell lung cancer harboring EGFR exon 20 mutations

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Chen D

2016-07-01

Full Text Available Dan Chen,1 Zhengbo Song,2 Guoping Cheng3 1Department of Cardiothoracic Surgery, The First Affiliated Hospital of Chongqing Medical University, Chongqing, 2Department of Chemotherapy, 3Department of Pathology, Zhejiang Cancer Hospital, Hangzhou, People’s Republic of China Purpose: Subsets of non-small-cell lung cancer patients with epidermal growth factor receptor (EGFR mutations carry uncommon subtypes. We evaluated the efficacy of first-generation EGFR-tyrosine kinase inhibitors (TKIs; erlotinib, gefitinib, and icotinib in patients with non-small-cell lung cancer carrying insertions and T790M and S768I mutations in EGFR exon 20. Patients and methods: Patients carrying EGFR exon 20 insertion/T790M/S768I mutations and treated with EGFR-TKIs were evaluated from 2005 to 2014 in Zhejiang Cancer Hospital. The efficacy was evaluated using the Kaplan–Meier method and compared with the log-rank test. Results: Sixty-two patients with exon 20 insertion/T790M/S768I mutations were enrolled. Mutations including exon 20 insertions and T790M and S768I mutations were observed in 29, 23, and ten patients, respectively. In total, the response rate and median progression-free survival (PFS were 8.1% and 2.1 months, respectively. Patients with S768I mutation manifested the longest median PFS (2.7 months, followed by those with T790M (2.4 months and exon 20 insertions (1.9 months; P=0.022. Patients with complex mutations show a better PFS than those with single mutations (2.7 months vs 1.9 months; P=0.034. Conclusion: First-generation EGFR-TKIs are less effective in patients with exon 20 uncommon mutations than in those with common mutations. Patients with complex mutations benefited more from first-generation EGFR-TKIs than those with single mutations. Keywords: non-small cell lung cancer, epidermal growth factor receptor, EGFR mutations, exon 20, tyrosine kinase inhibitor

HER2 induced EMT and tumorigenicity in breast epithelial progenitor cells is inhibited by coexpression of EGFR.

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Ingthorsson, S; Andersen, K; Hilmarsdottir, B; Maelandsmo, G M; Magnusson, M K; Gudjonsson, T

2016-08-11

The members of the epidermal growth factor receptor (EGFR) kinase family are important players in breast morphogenesis and cancer. EGFR2/HER2 and EGFR expression have a prognostic value in certain subtypes of breast cancer such as HER2-amplified, basal-like and luminal type B. Many clinically approved small molecular inhibitors and monoclonal antibodies have been designed to target HER2, EGFR or both. There is, however, still limited knowledge on how the two receptors are expressed in normal breast epithelium, what effects they have on cellular differentiation and how they participate in neoplastic transformation. D492 is a breast epithelial cell line with stem cell properties that can undergo epithelial to mesenchyme transition (EMT), generate luminal- and myoepithelial cells and form complex branching structures in three-dimensional (3D) culture. Here, we show that overexpression of HER2 in D492 (D492(HER2)) resulted in EMT, loss of contact growth inhibition and increased oncogenic potential in vivo. HER2 overexpression, furthermore, inhibited endogenous EGFR expression. Re-introducing EGFR in D492(HER2) (D492(HER2/EGFR)) partially reversed the mesenchymal state of the cells, as an epithelial phenotype reappeared both in 3D cultures and in vivo. The D492(HER2/EGFR) xenografts grow slower than the D492(HER2) tumors, while overexpression of EGFR alone (D492(EGFR)) was not oncogenic in vivo. Consistent with the EGFR-mediated epithelial phenotype, overexpression of EGFR drove the cells toward a myoepithelial phenotype in 3D culture. The effect of two clinically approved anti-HER2 and EGFR therapies, trastuzumab and cetuximab, was tested alone and in combination on D492(HER2) xenografts. While trastuzumab had a growth inhibitory effect compared with untreated control, the effect of cetuximab was limited. When administered in combination, the growth inhibitory effect of trastuzumab was less pronounced. Collectively, our data indicate that in HER2-overexpressing D492

Expressions and clinical significance of autophagy-related markers Beclin1, LC3, and EGFR in human cervical squamous cell carcinoma

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Hu YF

2015-08-01

Full Text Available Yun-Feng Hu,1 Xia Lei,2 Hong-Yi Zhang,3 Jun-wei Ma,1 Wei-wei Yang,1 Min-lin Chen,1 Jie Cui,1,4 Hong Zhao1 1Department of Oncology, 2Department of Gynecology, 3Department of Urology, Yan’an University Affiliated Hospital, Yan’an, Shaanxi Province, People’s Republic of China; 4Department of Oncology, the First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, Shaanxi Province, People’s Republic of China Purpose: We aimed to investigate the expression of EGFR and the autophagy-related markers Beclin1 and LC3 in cervical cancer.Methods: Beclin1, LC3, and EGFR expression were analyzed in 80 samples of cervical squamous cell carcinoma (SCC, 40 samples of high-grade cervical intraepithelial neoplasia (CIN, and 40 samples of normal cervical tissues by immunohistochemistry. The protein expression rates were analyzed with χ2 and Fisher’s exact tests. Differences in overall survival (OS were determined using the Kaplan–Meier method and log-rank tests.Results: Cervical cancer, high-grade CIN, and normal cervical epithelial cells expressed Beclin1 in 26.2%, 77.5%, and 82.5% of patients, respectively, and expressed LC3 in 28.8%, 70.0%, and 75.0% of patients, respectively. There was a significant difference between cervical SCC and high-grade CIN or normal cervical epithelial cells (P=0.000. Cervical cancer cells, high-grade CIN cells, and normal cervical epithelial cells expressed EGFR in 68.8%, 62.5%, and 12.5% of patients, respectively. There was a significant difference between cervical SCC or high-grade CIN and normal cervical epithelial cells (P=0.000. No significant association between Beclin1 or LC3 or EGFR expression and various clinicopathological parameters was observed in cervical SCC. There was no significant correlation between Beclin1, LC3, EGFR expression, and 5-year OS rates of cervical SCC patients. Beclin1- or LC3-negativity with EGFR-positivity in cervical SCC was associated with a higher Federation International of

Egfr Amplification Specific Gene Expression in Phyllodes Tumours of the Breast

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Konstantin Agelopoulos

2007-01-01

Full Text Available Background: Recently, we were able to show that amplifications of the epidermal growth factor receptor (egfr gene and the overexpression of EGFR were associated with the initiation and progression of phyllodes tumours. Methods: In order to gain further insights into regulation mechanisms associated with egfr amplifications and EGFR expression in phyllodes tumours, we performed global gene expression analysis (Affymetrix A133.2 on a series of 10 phyllodes tumours, of these three with and seven without amplifications of an important regulatory repeat in intron 1 of egfr (CA-SSR I. The results were verified and extended by means of immunohistochemistry using the tissue microarray method on an extensively characterized series of 58 phyllodes tumours with antibodies against caveolin-1, eps15, EGF, TGF-α, pErk, pAkt and mdm2. Results: We were able to show that the presence of egfr CA-SSR I amplifications in phyllodes tumours was associated with 230 differentially expressed genes. Caveolin-1 and eps15, involved in EGFR turnover and signalling, were regulated differentially on the RNA and protein level proportionally to egfr gene dosage. Further immunohistochemical analysis revealed that the expression of caveolin-1 and eps15 were also significantly correlated with the expression of pAkt (p < 0.05, pERK (p < 0.05, mdm2 (p < 0.01 and EGF (p < 0.001 for caveolin-1. Eps15 and pERK were further associated with tumour grade (p < 0.01 and p < 0.001, respectively. Conclusion: Our results show that amplifications within regulatory sequences of egfr are associated with the expression of eps15 and caveolin-1, indicating an increased turnover of EGFR. The interplay between EGFR and caveolin-1, eps15, pAkt, mdm2 and pERK therefore seems to present a major molecular pathway in carcinogenesis and progression of breast phyllodes tumours.

SOX2 plays a critical role in EGFR-mediated self-renewal of human prostate cancer stem-like cells.

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Rybak, Adrian P; Tang, Damu

2013-12-01

SOX2 is an essential transcription factor for stem cells and plays a role in tumorigenesis, however its role in prostate cancer stem cells (PCSCs) remains unclear. We report here a significant upregulation of SOX2 at both mRNA and protein levels in DU145 PCSCs propagated as suspension spheres in vitro. The expression of SOX2 in DU145 PCSCs is positively regulated by epidermal growth factor receptor (EGFR) signaling. Activation of EGFR signaling, following the addition of epidermal growth factor (EGF) or ectopic expression of a constitutively-active EGFR mutant (EGFRvIII), increased SOX2 expression and the self-renewal of DU145 PCSCs. Conversely, a small molecule EGFR inhibitor (AG1478) blocked EGFR activation, reduced SOX2 expression and inhibited PCSC self-renewal activity, implicating SOX2 in mediating EGFR-dependent self-renewal of PCSCs. In line with this notion, ectopic SOX2 expression enhanced EGF-induced self-renewal of DU145 PCSCs, while SOX2 knockdown reduced PCSC self-renewal with EGF treatment no longer capable of enhancing their propagation. Furthermore, SOX2 knockdown reduced the capacity of DU145 PCSCs to grow under anchorage-independent conditions. Finally, DU145 PCSCs generated xenograft tumors more aggressively with elevated levels of SOX2 expression compared to xenograft tumors derived from non-PCSCs. Collectively, we provide evidence that SOX2 plays a critical role in EGFR-mediated self-renewal of DU145 PCSCs. © 2013.

Association analysis of polymorphisms in EGFR, HER2, ESR1 and ...

African Journals Online (AJOL)

Background: Research in the genetic basis of coronary artery diseases (CAD) has identified some genes and pathways associated with diseases that would not be considered to underlie conventional risk factors. Among these genes there are the EGFR (epidermal growth factor receptor) receptor family genes and the ...

Guanylate binding protein 1 is a novel effector of EGFR-driven invasion in glioblastoma.

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Li, Ming; Mukasa, Akitake; Inda, Maria del-Mar; Zhang, Jianhua; Chin, Lynda; Cavenee, Webster; Furnari, Frank

2011-12-19

Although GBP1 (guanylate binding protein 1) was among the first interferon-inducible proteins identified, its function is still largely unknown. Epidermal growth factor receptor (EGFR) activation by amplification or mutation is one of the most frequent genetic lesions in a variety of human tumors. These include glioblastoma multiforme (GBM), which is characterized by independent but interrelated features of extensive invasion into normal brain parenchyma, rapid growth, necrosis, and angiogenesis. In this study, we show that EGFR activation promoted GBP1 expression in GBM cell lines through a signaling pathway involving Src and p38 mitogen-activated protein kinase. Moreover, we identified YY1 (Yin Yang 1) as the downstream transcriptional regulator regulating EGFR-driven GBP1 expression. GBP1 was required for EGFR-mediated MMP1 (matrix metalloproteinase 1) expression and glioma cell invasion in vitro. Although deregulation of GBP1 expression did not affect glioma cell proliferation, overexpression of GBP1 enhanced glioma cell invasion through MMP1 induction, which required its C-terminal helical domain and was independent of its GTPase activity. Reducing GBP1 levels by RNA interference in invasive GBM cells also markedly inhibited their ability to infiltrate the brain parenchyma of mice. GBP1 expression was high and positively correlated with EGFR expression in human GBM tumors and cell lines, particularly those of the neural subtype. Together, these findings establish GBP1 as a previously unknown link between EGFR activity and MMP1 expression and nominate it as a novel potential therapeutic target for inhibiting GBM invasion.

Analysis of EGFR, HER2, and TOP2A gene status and chromosomal polysomy in gastric adenocarcinoma from Chinese patients

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Liang, Zhiyong; Zeng, Xuan; Gao, Jie; Wu, Shafei; Wang, Peng; Shi, Xiaohua; Zhang, Jing; Liu, Tonghua

2008-01-01

The EGFR and HER2 genes are located on chromosomes 7 and 17, respectively. They are therapeutic targets in some tumors. The TOP2A gene, which is located near HER2 on chromosome 17, is the target of many chemotherapeutic agents, and co-amplification of HER2 and TOP2A has been described in several tumor types. Herein, we investigated the gene status of EGFR, HER2, and TOP2A in Chinese gastric carcinoma patients. We determined the rate of polysomy for chromosomes 7 and 17, and we attempted to clarify the relationship between EGFR, HER2, and TOP2A gene copy number and increased expression of their encoded proteins. Furthermore, we tried to address the relationship between alterations in EGFR, HER2, and TOP2A and chromosome polysomy. One hundred cases of formalin fixed and paraffin embedded tumor tissues from Chinese gastric carcinoma patients were investigated by immunohistochemistry and fluorescence in situ hybridization (FISH) methods. Forty-two percent of the cases showed EGFR overexpression; 16% showed EGFR FISH positive; 6% showed HER2 overexpression; and 11% showed HER2 gene amplification, including all six HER2 overexpression cases. TOP2A nuclear staining (nuclear index, NI) was determined in all 100 tumors: NI values ranged from 0.5 – 90%. Three percent of the tumors showed TOP2A gene amplification, which were all accompanied by HER2 gene amplification. Nineteen percent of the tumors showed chromosome 7 polysomy, and 16% showed chromosome 17 polysomy. Chromosome 7 polysomy correlated significantly with EGFR FISH-positivity, but was not associated with EGFR overexpression. HER2 overexpression associated significantly with HER2 gene amplification. TOP2A gene amplification was significantly associated with HER2 gene amplification. No relationship was found between alterations in the EGFR, HER2, and TOP2A genes and clinicopathologic variables of gastric carcinoma. The data from our study suggest that chromosome 7 polysomy may be responsible for increased EGFR

Antitumor activity of TY-011 against gastric cancer by inhibiting Aurora A, Aurora B and VEGFR2 kinases

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Wang Liu

2016-11-01

Full Text Available Abstract Background Overexpression of Aurora A and B has been reported in a wide range of tumor types, including gastric cancer. Anti-angiogenesis has been considered as an important therapeutic modality in advanced gastric cancer. Here we identified a novel compound TY-011 with promising antitumor activity by targeting mitotic kinases (Aurora A and B and angiogenic receptor tyrosine kinase (VEGFR2. Methods HTRF® KinEASE™ assay was used to detect the effect of TY-011 against Aurora A, Aurora B and VEGFR2 activities. Docking simulation study was performed to predict the binding mode of TY-011 with Aurora A and B kinases. CCK-8 assay was used to test cell growth. Cell cycle and cell apoptosis was analyzed by flow cytometry. Gastric cancer cell xenograft mouse models were used for in vivo study. TUNEL kit was used to determine the apoptosis of tumor tissues. Immunohistochemistry analysis and HUVEC tube formation assay were performed to determine the anti-angiogenesis ability. Immunofluorescence and western blot were used to test protein expression. Results TY-011 was identified as a potential Aurora A and B inhibitor by HTRF® KinEASE™ assay. It effectively inhibited cellular Aurora A and B activities in a concentration-dependent manner. TY-011 occupied the ATP-binding site of both Aurora A and B kinases. TY-011 demonstrated prominent inhibitory effects on proliferation of gastric cancer cells. TY-011 treatment induced an obvious accumulation of cells at G2/M phase and a modest increase of cells with >4 N DNA content, which then underwent apoptosis. Meaningfully, orally administration of TY-011 demonstrated superior efficacy against the tumor growth in gastric cancer cell xenograft, with ~90% inhibition rate and 100% tumor regression at 9 mg/kg dose, and TY-011 did not affect the body weight of mice. Interestingly, we observed that TY-011 also antagonized tumor angiogenesis by targeting VEGFR2 kinase. Conclusions These results indicate that

Distribution of estimated glomerular filtration rate (eGFR) values in patients receiving contrast-enhanced magnetic resonance imaging

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Shimoji, Keigo; Aoki, Shigeki; Nakanishi, Atsushi

2012-01-01

The aim of this study was to elucidate the distribution of estimated glomerular filtration rate (eGFR) values in patients who underwent gadolinium-based contrast agent (GBCA)-enhanced magnetic resonance imaging (MRI) at different types of hospitals. We retrospectively studied 2,550 patients who underwent MRI at five institutions. We recorded the date and value of each patient's eGFR test. The distribution of eGFR values was compared with that in the general Japanese population. A total of 84.3% of patients had their eGFRs evaluated before GBCA-enhanced MRI. Of these, 84.7% were evaluated within 3 months before the GBCA-enhanced MRI, and 1.3% were evaluated on the day of the GBCA-enhanced MRI. A total of 87.2% of patients tested had an eGFR of ≥60 ml/min/1.73 m 2 ; 12.8% had an eGFR of 2 , and no patients had an eGFR of 2 . The rate of renal function evaluation differed among hospitals. The prevalence of low eGFR values was greater in Juntendo Tokyo Koto Geriatric Medical Center than in the other hospitals, and the prevalence of low eGFR values was greater in patients who underwent GBCA-enhanced MRI than in the general Japanese population. (author)

Evolution of a New Class of VEGFR-2 Inhibitors from Scaffold Morphing and Redesign.

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Mainolfi, Nello; Karki, Rajeshri; Liu, Fang; Anderson, Karen

2016-04-14

Anti-VEGF therapy is a clinically validated treatment for age-related macular degeneration (AMD). We have recently reported the discovery of oral VEGFR-2 inhibitors that are selectively distributed to the ocular tissues. Herein we report a further development of those compounds and in particular the validation of the hypothesis that aminoheterocycles such as aminoisoxazoles and aminopyrazoles could also function as effective "hinge" binding moieties leading to a new class of KDR (kinase insert domain containing receptor) inhibitors.

Cellular Response to Titanium Dioxide Nanoparticles in Intestinal Epithelial Caco-2 Cells is Dependent on Endocytosis-Associated Structures and Mediated by EGFR

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Krüger, Kristin; Schrader, Katrin; Klempt, Martin

2017-01-01

Titanium dioxide (TiO2) is one of the most applied nanomaterials and widely used in food and non-food industries as an additive or coating material (E171). It has been shown that E171 contains up to 37% particles which are smaller than 100 nm and that TiO2 nanoparticles (NPs) induce cytotoxicity and inflammation. Using a nuclear factor Kappa-light-chain enhancer of activated B cells (NF-κB) reporter cell line (Caco-2nfkb-RE), Real time polymerase chain reaction (PCR), and inhibition of dynamin and clathrin, it was shown that cellular responses induced by 5 nm and 10 nm TiO2 NPs (nominal size) depends on endocytic processes. As endocytosis is often dependent on the epithelial growth factor receptor (EGFR), further investigations focused on the involvement of EGFR in the uptake of TiO2 NPs: (1) inhibition of EGFR reduced inflammatory markers of the cell (i.e., nuclear factor (NF)-κB activity, mRNA of IL8, CCL20, and CXCL10); and (2) exposure of Caco-2 cells to TiO2 NPs activated the intracellular EGFR cascade beginning with EGFR-mediated extracellular signal-regulated kinases (ERK)1/2, and including transcription factor ELK1. This was followed by the expression of ERK1/2 target genes CCL2 and CXCL3. We concluded that TiO2 NPs enter the cell via EGFR-associated endocytosis, followed by activation of the EGFR/ERK/ELK signaling pathway, which finally induces NF-κB. No changes in inflammatory response are observed in Caco-2 cells exposed to 32 nm and 490 nm TiO2 particles. PMID:28387727

Collagen type I induces EGFR-TKI resistance in EGFR-mutated cancer cells by mTOR activation through Akt-independent pathway.

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Yamazaki, Shota; Higuchi, Youichi; Ishibashi, Masayuki; Hashimoto, Hiroko; Yasunaga, Masahiro; Matsumura, Yasuhiro; Tsuchihara, Katsuya; Tsuboi, Masahiro; Goto, Koichi; Ochiai, Atsushi; Ishii, Genichiro

2018-06-01

Primary resistance to epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) is a serious problem in lung adenocarcinoma patients harboring EGFR mutations. The aim of this study was to examine whether and how collagen type I (Col I), the most abundantly deposited matrix in tumor stroma, affects EGFR-TKI sensitivity in EGFR-mutant cells. We evaluated the EGFR-TKI sensitivity of EGFR-mutated cancer cells cultured with Col I. Changes in the activation of downstream signaling molecules of EGFR were analyzed. We also examined the association between the Col I expression in tumor stroma in surgical specimens and EGFR-TKI response of postoperative recurrence patients with EGFR mutations. Compared to cancer cells without Col I, the survival rate of cancer cells cultured with Col I was significantly higher after EGFR-TKI treatment. In cancer cells cultured with and without Col I, EGFR-TKI suppressed the levels of phosphorylated (p-)EGFR, p-ERK1/2, and p-Akt. When compared to cancer cells without Col I, expression of p-P70S6K, a hallmark of mTOR activation, was dramatically upregulated in cancer cells with Col I. This activation was maintained even after EGFR-TKI treatment. Simultaneous treatment with EGFR-TKI and mTOR inhibitor abrogated Col I-induced resistance to EGFR-TKI. Patients with Col I-rich stroma had a significantly shorter progression-free survival time after EGFR-TKI therapy (238 days vs 404 days; P Cancer Science published by John Wiley & Sons Australia, Ltd on behalf of Japanese Cancer Association.

Exposure of chick embryos to cadmium changes the extra-embryonic vascular branching pattern and alters expression of VEGF-A and VEGF-R2

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Gheorghescu, Anna Kaskova [School of Medicine and Medical Science, University College Dublin, Belfield, Dublin 4 (Ireland); Tywoniuk, Bartlomiej [School of Physics, University College Dublin, Belfield, Dublin 4 (Ireland); Complex and Adaptive Systems Laboratory, University College Dublin, Belfield, Dublin 4 (Ireland); Duess, Johannes [School of Medicine and Medical Science, University College Dublin, Belfield, Dublin 4 (Ireland); National Children' s Research Centre, Our Lady' s Children' s Hospital, Crumlin, Dublin 12 (Ireland); Buchete, Nicolae-Viorel, E-mail: buchete@ucd.ie [School of Physics, University College Dublin, Belfield, Dublin 4 (Ireland); Complex and Adaptive Systems Laboratory, University College Dublin, Belfield, Dublin 4 (Ireland); Thompson, Jennifer, E-mail: jennifer.thompson@ucd.ie [School of Medicine and Medical Science, University College Dublin, Belfield, Dublin 4 (Ireland)

2015-11-15

Cadmium (Cd) has several industrial applications, and is found in tobacco products, a notable source of human exposure. Vascular endothelial cells are key targets of Cd toxicity. Here, we aim to quantify the alteration to vascular branching pattern following Cd exposure in the chick extra-embryonic membrane (EEM) using fractal analysis, and explore molecular cues to angiogenesis such as VEGF-A and VEGF-R2 expression following Cd treatment. Chicken embryos were incubated for 60 h to Hamburger–Hamilton developmental stage 16–17, then explanted and treated with 50 μL of 50 μmol cadmium acetate (CdAc) or an equivalent volume of equimolar sodium acetate (NaAc). Images of embryos and their area vasculosa (AV) were captured and analyzed at 4 different time points (4, 8, 24 and 48 h) following treatment. Vascular branching in the AV was quantified using its fractal dimension (D{sub f}), estimated using a box counting method. Gallinaceous VEGF ELISA was used to measure the VEGF-A concentration in the EEM following treatment, with determination of the relative expression of VEGF-A and VEGF-R2 using quantitative real-time RT-PCR. Vascular branching increased monotonically in the control group at all time points. The anti-angiogenic effect of Cd exposure on the AV was reflected by a significant reduction in D{sub f} when compared with controls. D{sub f} was more markedly reduced in cultures with abnormal embryos. The expression of VEGF-A protein, and VEGF-A and VEGF-R2 mRNA were reduced in Cd-exposed EEMs. Both molecules contribute to growth, vessel sprouting and branching processes, which supports our findings using fractal analysis. - Highlights: • The chick area vasculosa was undersized in embryos exposed to 50 μM cadmium acetate. • Fractal dimension was reduced in the AV after Cd exposure, indicating decreased branching. • VEGF-A protein was decreased in Cd-treated extraembryonic membranes. • VEGF-A and VEGF-R2 mRNA was decreased in Cd-treated extraembryonic

Prognostic value of plasma EGFR ctDNA in NSCLC patients treated with EGFR-TKIs.

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Chengjuan Zhang

Full Text Available Epidermal growth factor receptor (EGFR specific mutations have been known to improve survival of patients with non-small-cell lung carcinoma (NSCLC. However, whether there are any changes of EGFR mutations after targeted therapy and its clinical significance is unclear. This study was to identify the status of EGFR mutations after targeted therapy and predict the prognostic significance for NSCLC patients.A total of forty-five (45 NSCLC patients who received EGFR-TKI therapy were enrolled. We identified the changes of EGFR mutations in plasma ctDNA by Amplification Refractory Mutation System (ARMS PCR technology.In the 45 cases of NSCLC with EGFR mutations, the EGFR mutation status changed in 26 cases, in which, 12 cases (26.7% from positive to negative, and 14 cases (31.1% from T790M mutation negative to positive after TKI targeted therapy. The T790M occurance group had a shorter Progression -Free-Survival (PFS than the groups of EGFR mutation undetected and EGFR mutation turned out to have no change after EGFR-TKI therapy (p < 0.05.According to this study, it's necessary to closely monitor EGFR mutations during follow-up to predict the prognosis of NSCLC patients who are to receive the TKI targeted therapy.

Targeting EGFR/HER2 pathways enhances the antiproliferative effect of gemcitabine in biliary tract and gallbladder carcinomas

International Nuclear Information System (INIS)

Pignochino, Ymera; Bardelli, Alberto; Aglietta, Massimo; Leone, Francesco; Sarotto, Ivana; Peraldo-Neia, Caterina; Penachioni, Junia Y; Cavalloni, Giuliana; Migliardi, Giorgia; Casorzo, Laura; Chiorino, Giovanna; Risio, Mauro

2010-01-01

Advanced biliary tract carcinomas (BTCs) have poor prognosis and limited therapeutic options. Therefore, it is crucial to combine standard therapies with molecular targeting. In this study EGFR, HER2, and their molecular transducers were analysed in terms of mutations, amplifications and over-expression in a BTC case series. Furthermore, we tested the efficacy of drugs targeting these molecules, as single agents or in combination with gemcitabine, the standard therapeutic agent against BTC. Immunohistochemistry, FISH and mutational analysis were performed on 49 BTC samples of intrahepatic (ICCs), extrahepatic (ECCs), and gallbladder (GBCs) origin. The effect on cell proliferation of different EGFR/HER2 pathway inhibitors as single agents or in combination with gemcitabine was investigated on BTC cell lines. Western blot analyses were performed to investigate molecular mechanisms of targeted drugs. EGFR is expressed in 100% of ICCs, 52.6% of ECCs, and in 38.5% of GBCs. P-MAPK and p-Akt are highly expressed in ICCs (>58% of samples), and to a lower extent in ECCs and GBCs (<46%), indicating EGFR pathway activation. HER2 is overexpressed in 10% of GBCs (with genomic amplification), and 26.3% of ECCs (half of which has genomic amplification). EGFR or its signal transducers are mutated in 26.5% of cases: 4 samples bear mutations of PI3K (8.2%), 3 cases (6.1%) in K-RAS, 4 (8.2%) in B-RAF, and 2 cases (4.1%) in PTEN, but no loss of PTEN expression is detected. EGI-1 cell line is highly sensitive to gemcitabine, TFK1 and TGBC1-TKB cell lines are responsive and HuH28 cell line is resistant. In EGI-1 cells, combination with gefitinib further increases the antiproliferative effect of gemcitabine. In TFK1 and TGBC1-TKB cells, the efficacy of gemcitabine is increased with addiction of sorafenib and everolimus. In TGBC1-TKB cells, lapatinib also has a synergic effect with gemcitabine. HuH28 becomes responsive if treated in combination with erlotinib. Moreover, HuH28 cells are

IQGAP1-dependent signaling pathway regulates endothelial cell proliferation and angiogenesis.

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Rosana D Meyer

Full Text Available Vascular endothelial growth factor receptor-2 (VEGFR-2 signaling is an obligate requirement for normal development and pathological angiogenesis such as cancer and age-related macular degeneration. Although autophosphorylation of tyrosine 1173 (Y1173 of VEGFR-2 is considered a focal point for its angiogenic signal relay, however, the mechanism of phosphorylation of Y1173, signaling proteins that are recruited to this residue and their role in angiogenesis is not fully understood.In this study we demonstrate that c-Src kinase directly through its Src homology 2 (SH2 domain and indirectly via c-Cbl binds to phospho-Y1057 of VEGFR-2. Activation of c-Src kinase by a positive feedback mechanism phosphorylates VEGFR-2 at multi-docking site, Y1173. c-Src also catalyzes tyrosine phosphorylation of IQGAP1 and acts as an adaptor to bridge IQGAP1 to VEGFR-2. In turn, IQGAP1 activates b-Raf and mediates proliferation of endothelial cells. Silencing expression of IQGAP1 and b-Raf revealed that their activity is essential for VEGF to stimulate angiogenesis in an in vivo angiogenesis model of chicken chorioallantoic membrane (CAM.Angiogenesis contributes to the pathology of numerous human diseases ranging from cancer to age-related macular degeneration. Determining molecular mechanism of tyrosine phosphorylation of VEGFR-2 and identification of molecules that are relaying its angiogenic signaling may identify novel targets for therapeutic intervention against angiogenesis-associated diseases. Our study shows that recruitment and activation of c-Src by VEGFR-2 plays a pivotal role in relaying angiogenic signaling of VEGFR-2; it phosphorylates VEGFR-2 at Y1173, facilitates association and activation of IQGAP1 and other signaling proteins to VEGFR-2. IQGAP1-dependent signaling, in part, is critically required for endothelial cell proliferation, a key step in angiogenesis. Thus, Y1057 of VEGFR-2 serves to regulate VEGFR-2 function in a combinatorial manner by

Tumor-targeted Nanobullets: Anti-EGFR nanobody-liposomes loaded with anti-IGF-1R kinase inhibitor for cancer treatment.

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van der Meel, Roy; Oliveira, Sabrina; Altintas, Isil; Haselberg, Rob; van der Veeken, Joris; Roovers, Rob C; van Bergen en Henegouwen, Paul M P; Storm, Gert; Hennink, Wim E; Schiffelers, Raymond M; Kok, Robbert J

2012-04-30

The epidermal growth factor receptor (EGFR) is a validated target for anti-cancer therapy and several EGFR inhibitors are used in the clinic. Over the years, an increasing number of studies have reported on the crosstalk between EGFR and other receptors that can contribute to accelerated cancer development or even acquisition of resistance to anti-EGFR therapies. Combined targeting of EGFR and insulin-like growth factor 1 receptor (IGF-1R) is a rational strategy to potentiate anti-cancer treatment and possibly retard resistance development. In the present study, we have pursued this by encapsulating the kinase inhibitor AG538 in anti-EGFR nanobody-liposomes. The thus developed dual-active nanobody-liposomes associated with EGFR-(over)expressing cells in an EGFR-specific manner and blocked both EGFR and IGF-1R activation, due to the presence of the EGFR-blocking nanobody EGa1 and the anti-IGF-1R kinase inhibitor AG538 respectively. AG538-loaded nanobody-liposomes induced a strong inhibition of tumor cell proliferation even upon short-term exposure followed by a drug-free wash-out period. Therefore, AG538-loaded nanobody-liposomes are a promising anti-cancer formulation due to efficient intracellular delivery of AG538 in combination with antagonistic and downregulating properties of the EGa1 nanobody-liposomes. Copyright © 2011 Elsevier B.V. All rights reserved.

Quantitative PET of EGFR expression in xenograft-bearing mice using 64Cu-labeled cetuximab, a chimeric anti-EGFR monoclonal antibody

International Nuclear Information System (INIS)

Cai, Weibo; Chen, Kai; He, Lina; Cao, Qizhen; Chen, Xiaoyuan; Koong, Albert

2007-01-01

Cetuximab, a chimeric monoclonal antibody targeting epidermal growth factor receptor (EGFR) on the surface of cancer cells, was approved by the FDA to treat patients with metastatic colorectal cancer. It is currently also in advanced-stage development for the treatment of several other solid tumors. Here we report for the first time the quantitative positron emission tomography (PET) imaging of EGFR expression in xenograft-bearing mice using 64 Cu-labeled cetuximab. We conjugated cetuximab with macrocyclic chelating agent 1,4,7,10-tetraazadodecane-N,N',N'',N'''-tetraacetic acid (DOTA), labeled with 64 Cu, and tested the resulting 64 Cu-DOTA-cetuximab in seven xenograft tumor models. The tracer uptake measured by PET was correlated with the EGFR expression quantified by western blotting. The estimated human dosimetry based on the PET data in Sprague-Dawley rats was also calculated. MicroPET imaging showed that 64 Cu-DOTA-cetuximab had increasing tumor activity accumulation over time in EGFR-positive tumors but relatively low uptake in EGFR-negative tumors at all times examined ( 2 0.80) between the tracer uptake (measured by PET) and the EGFR expression level (measured by western blotting). Human dosimetry estimation indicated that the tracer may be safely administered to human patients for tumor diagnosis, with the dose-limiting organ being the liver. The success of EGFR-positive tumor imaging using 64 Cu-DOTA-cetuximab can be translated into the clinic to characterize the pharmacokinetics, to select the right population of patients for EGFR-targeted therapy, to monitor the therapeutic efficacy of anti-EGFR treatment, and to optimize the dosage of either cetuximab alone or cetuximab in combination with other therapeutic agents. (orig.)

The use of radiocobalt as a label improves imaging of EGFR using DOTA-conjugated Affibody molecule.

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Garousi, Javad; Andersson, Ken G; Dam, Johan H; Olsen, Birgitte B; Mitran, Bogdan; Orlova, Anna; Buijs, Jos; Ståhl, Stefan; Löfblom, John; Thisgaard, Helge; Tolmachev, Vladimir

2017-07-20

Several anti-cancer therapies target the epidermal growth factor receptor (EGFR). Radionuclide imaging of EGFR expression in tumours may aid in selection of optimal cancer therapy. The 111 In-labelled DOTA-conjugated Z EGFR:2377 Affibody molecule was successfully used for imaging of EGFR-expressing xenografts in mice. An optimal combination of radionuclide, chelator and targeting protein may further improve the contrast of radionuclide imaging. The aim of this study was to evaluate the targeting properties of radiocobalt-labelled DOTA-Z EGFR:2377 . DOTA-Z EGFR:2377 was labelled with 57 Co (T 1/2  = 271.8 d), 55 Co (T 1/2  = 17.5 h), and, for comparison, with the positron-emitting radionuclide 68 Ga (T 1/2  = 67.6 min) with preserved specificity of binding to EGFR-expressing A431 cells. The long-lived cobalt radioisotope 57 Co was used in animal studies. Both 57 Co-DOTA-Z EGFR:2377 and 68 Ga-DOTA-Z EGFR:2377 demonstrated EGFR-specific accumulation in A431 xenografts and EGFR-expressing tissues in mice. Tumour-to-organ ratios for the radiocobalt-labelled DOTA-Z EGFR:2377 were significantly higher than for the gallium-labelled counterpart already at 3 h after injection. Importantly, 57 Co-DOTA-Z EGFR:2377 demonstrated a tumour-to-liver ratio of 3, which is 7-fold higher than the tumour-to-liver ratio for 68 Ga-DOTA-Z EGFR:2377 . The results of this study suggest that the positron-emitting cobalt isotope 55 Co would be an optimal label for DOTA-Z EGFR:2377 and further development should concentrate on this radionuclide as a label.

Correlation of EGFR expression, gene copy number and clinicopathological status in NSCLC.

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Gaber, Rania; Watermann, Iris; Kugler, Christian; Reinmuth, Nils; Huber, Rudolf M; Schnabel, Philipp A; Vollmer, Ekkehard; Reck, Martin; Goldmann, Torsten

2014-09-17

Epidermal Growth Factor Receptor (EGFR) targeting therapies are currently of great relevance for the treatment of lung cancer. For this reason, in addition to mutational analysis immunohistochemistry (IHC) of EGFR in lung cancer has been discussed for the decision making of according therapeutic strategies. The aim of this study was to obtain standardization of EGFR-expression methods for the selection of patients who might benefit of EGFR targeting therapies. As a starting point of a broad investigation, aimed at elucidating the expression of EGFR on different biological levels, four EGFR specific antibodies were analyzed concerning potential differences in expression levels by Immunohistochemistry (IHC) and correlated with fluorescence in situ hybridization (FISH) analysis and clinicopathological data. 206 tumor tissues were analyzed in a tissue microarray format employing immunohistochemistry with four different antibodies including Dako PharmDx kit (clone 2-18C9), clone 31G7, clone 2.1E1 and clone SP84 using three different scoring methods. Protein expression was compared to FISH utilizing two different probes. EGFR protein expression determined by IHC with Dako PharmDx kit, clone 31G7 and clone 2.1E1 (p ≤ 0.05) correlated significantly with both FISH probes independently of the three scoring methods; best correlation is shown for 31G7 using the scoring method that defined EGFR positivity when ≥ 10% of the tumor cells show membranous staining of moderate and severe intensity (p=0.001). Overall, our data show differences in EGFR expression determined by IHC, due to the applied antibody. Highest concordance with FISH is shown for antibody clone 31G7, evaluated with score B (p=0.001). On this account, this antibody clone might by utilized for standard evaluation of EGFR expression by IHC. The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/13000_2014_165.

Tumor VEGF-R2 imaging with Tc-99m DTPA-dextran-DC101

International Nuclear Information System (INIS)

Kim, E. M.; Jeong, H. J.; Kim, S. L.; Jeong, S. J.; Lee, C. M.; Kim, D. W.; Lim, S. T.; Sohn, M. H.

2007-01-01

Vascular endothelial growth factor (VEGF) and its receptor (fetal liver kinase 1/kinase insert domain-containing receptor) play an important role in vascular permeability and tumor angiogenesis. Here, we investigated the Tc-99m DC101-dextran for VEGF-R2 imaging in tumor xenografted mice. DTPA conjugated amino-dextran was synthesized and then this was reacted with sulfo-LC-SPDP. Synthesis was identified by 1H-NMR. DTPA-dextran-SPDP was reacted with DC101. Binding affinity was checked by ELISA assay. Female athymic nude mice bearing B16F10 tumors were each injected via the tail vein with about 18.5 MBq of the Tc-99m DTPA-dextran-DC101, Tc-99m DTPA-DC101 and I-131 DC101. Biodistribution was performed at 1, 6, and 24h. DTPA-dextran-DC101 bind to FLK-1 in a dose-dependent manner. And this was blocked by significantly by free DC101. Labeling efficiency was approximately above 99% at 24 hr. Tc-99m DTPA-DC101 and I-131 DC101 showed rapid liver uptake, whereas Tc-99m DTPA-dextran-DC101 weak liver uptake and kidney elimination. In biodistribution results, Tc-99m DTPA-dextran-DC101 showed rapid renal clearance, and increased tumor uptake according to the time. Conjugation of antibody with dextran polymer is responsible for the decreased liver uptake and increased tumor uptake

Serum bilirubin concentration is associated with eGFR and urinary albumin excretion in patients with type 1 diabetes mellitus.

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Nishimura, Takeshi; Tanaka, Masami; Sekioka, Risa; Itoh, Hiroshi

2015-01-01

Although relationships of serum bilirubin concentration with estimated glomerular filtration rate (eGFR) and urinary albumin excretion (UAE) in patients with type 2 diabetes have been reported, whether such relationships exist in patients with type 1 diabetes is unknown. A total of 123 patients with type 1 diabetes were investigated in this cross-sectional study. The relationship between bilirubin (total and indirect) concentrations and log(UAE) as well as eGFR was examined by Pearson's correlation analyses. Multivariate regression analyses were used to assess the association of bilirubin (total and indirect) with eGFR as well as log(UAE). A positive correlation was found between serum bilirubin concentration and eGFR; total bilirubin (r=0.223, p=0.013), indirect bilirubin (r=0.244, p=0.007). A negative correlation was found between serum bilirubin concentration and log(UAE); total bilirubin (r=-0.258, p=0.005), indirect bilirubin (r=-0.271, p=0.003). Multivariate regression analyses showed that indirect bilirubin concentration was an independent determinant of eGFR and log(UAE). Bilirubin concentration is associated with both eGFR and log(UAE) in patients with type 1 diabetes. Bilirubin might have a protective role in the progression of type 1 diabetic nephropathy. Copyright © 2015 Elsevier Inc. All rights reserved.

iRhom2 promotes lupus nephritis through TNF-α and EGFR signaling.

Science.gov (United States)

Qing, Xiaoping; Chinenov, Yurii; Redecha, Patricia; Madaio, Michael; Roelofs, Joris Jth; Farber, Gregory; Issuree, Priya D; Donlin, Laura; Mcllwain, David R; Mak, Tak W; Blobel, Carl P; Salmon, Jane E

2018-04-02

Lupus nephritis (LN) often results in progressive renal dysfunction. The inactive rhomboid 2 (iRhom2) is a newly identified key regulator of A disintegrin and metalloprotease 17 (ADAM17), whose substrates, such as TNF-α and heparin-binding EGF (HB-EGF), have been implicated in the pathogenesis of chronic kidney diseases. Here, we demonstrate that deficiency of iRhom2 protects the lupus-prone Fcgr2b-/- mice from developing severe kidney damage without altering anti-double-stranded DNA (anti-dsDNA) Ab production by simultaneously blocking HB-EGF/EGFR and TNF-α signaling in the kidney tissues. Unbiased transcriptome profiling of kidneys and kidney macrophages revealed that TNF-α and HB-EGF/EGFR signaling pathways are highly upregulated in Fcgr2b-/- mice, alterations that were diminished in the absence of iRhom2. Pharmacological blockade of either TNF-α or EGFR signaling protected Fcgr2b-/- mice from severe renal damage. Finally, kidneys from LN patients showed increased iRhom2 and HB-EGF expression, with interstitial HB-EGF expression significantly associated with chronicity indices. Our data suggest that activation of iRhom2/ADAM17-dependent TNF-α and EGFR signaling plays a crucial role in mediating irreversible kidney damage in LN, thereby uncovering a target for selective and simultaneous dual inhibition of 2 major pathological pathways in the effector arm of the disease.

99mTc labeled anti EGFR Nanobody pentamer for tumor radioimmunoimaging

International Nuclear Information System (INIS)

Ding Zhiling; Lan Xiaoli; Li Chongjiao; Pei Zhijun; Zhang Yongxue; Wang Lifei; Gao Bin

2014-01-01

Novel Nanobody has small molecular weight and lower affinity. Appropriate polymer would be more suitable for radioimmunoimaging. In this study, we labeled anti EGFR Nanobody pentamer with 99m Tc to prepare tumor targeting imaging agent and to investigate its binding characteristics of tumor cells and tissues in vitro and in vivo, and to explore the feasibility of 99m Tc-EGFR Nanobody pentamer for tumor radioimmunoimaging compared with anti EGFR Nanobody monomer. EGFR Nanobody labeled with 99m Tc through tricarbonyl intermediate. The labeled compounds were purified by an ultra centrifugal filter; The labeling efficiency was determined by thin layer chromatography (TLC), and the radiochemical purity more than 95%. In vitro, 99m Tc-EGFR Nanobody monomer and pentamer have the specific binding capability with EGFR overexpression A431 tumor cell. the binding rate of 99m Tc-EGFR Nanobody monomer higher than that of pentamer (11.32% ± 2.73% vs 5.80% ± 0.92%, P < O.05). In A431 xenografted tumor was clearly displayed after intravenous injection of 99m Tc-EGFR Nanobody pentamer at l.5 h, T/NT maximum was 2.9 (1.5 h), whereas, the tumor tissues was not obviously found using 99m Tc-EGFR Nanobody monomer. The negative EGFR expression OCM-I xenografted tumor was not showed in both monomer and pentamer tracer. The experiment indicated that 99m Tc-EGFR Nanobody pentamer are appropriate for tumor radioimmunoimaging and has the potential value for the further study. (authors)

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.

Radiotherapy modulates expression of EGFR, ERCC1 and p53 in cervical cancer

Energy Technology Data Exchange (ETDEWEB)

Almeida, V.H. de; Melo, A.C. de; Nogueira-Rodrigues, A.; Pimenta-Inada, H.K.; Alves, F.G.; Moralez, G.; Thiago, L.S.; Ferreira, C.G.; Sternberg, C., E-mail: diretoriaexecutiva@sboc.org.br [Instituto Nacional de Câncer (INCA), Rio de Janeiro, RJ (Brazil); Meira, D.D. [Universidade Federal do Espírito Santo (UFES), Vitória, ES (Brazil); Pires, A.C. [Fonte Medicina Diagnóstica, Niterói, RJ (Brazil)

2018-02-01

Cervical cancer is a public health problem and the molecular mechanisms underlying radioresistance are still poorly understood. Here, we evaluated the modulation of key molecules involved in cell proliferation, cell cycle and DNA repair in cervical cancer cell lines (CASKI and C33A) and in malignant tissues biopsied from 10 patients before and after radiotherapy. The expression patterns of epidermal growth factor receptor (EGFR), excision repair cross-complementation group 1 (ERCC1) and p53 were evaluated in cancer cell lines by quantitative PCR and western blotting, and in human malignant tissues by immunohistochemistry. The mutation status of TP53 gene was evaluated by direct sequencing. Among cell lines, absent or weak modulations of EGFR, ERCC1 and p53 were observed after exposure to 1.8 Gy. Conversely, increased expressions of p53 (5/10 patients; P=0.0239), ERCC1 (5/10 patients; P=0.0294) and EGFR (4/10 patients; P=0.1773) were observed in malignant tissues after radiotherapy with the same radiation dose. TP53 mutations were found only in one patient. Here we show that a single dose of radiotherapy induced EGFR, ERCC1 and p53 expression in malignant tissues from cervical cancer patients but not in cancer cell lines, highlighting the gap between in vitro and in vivo experimental models. Studies on larger patient cohorts are needed to allow an interpretation that an up regulation of p53, EGFR and ERCC1 may be part of a radioresistance mechanism. (author)

Cellular Response to Titanium Dioxide Nanoparticles in Intestinal Epithelial Caco-2 Cells is Dependent on Endocytosis-Associated Structures and Mediated by EGFR.

Science.gov (United States)

Krüger, Kristin; Schrader, Katrin; Klempt, Martin

2017-04-07

Titanium dioxide (TiO₂) is one of the most applied nanomaterials and widely used in food and non-food industries as an additive or coating material (E171). It has been shown that E171 contains up to 37% particles which are smaller than 100 nm and that TiO₂ nanoparticles (NPs) induce cytotoxicity and inflammation. Using a nuclear factor Kappa-light-chain enhancer of activated B cells (NF-κB) reporter cell line (Caco-2 nfkb-RE ), Real time polymerase chain reaction (PCR), and inhibition of dynamin and clathrin, it was shown that cellular responses induced by 5 nm and 10 nm TiO₂ NPs (nominal size) depends on endocytic processes. As endocytosis is often dependent on the epithelial growth factor receptor (EGFR), further investigations focused on the involvement of EGFR in the uptake of TiO₂ NPs: (1) inhibition of EGFR reduced inflammatory markers of the cell (i.e., nuclear factor (NF)-κB activity, mRNA of IL8, CCL20, and CXCL10); and (2) exposure of Caco-2 cells to TiO₂ NPs activated the intracellular EGFR cascade beginning with EGFR-mediated extracellular signal-regulated kinases (ERK)1/2, and including transcription factor ELK1. This was followed by the expression of ERK1/2 target genes CCL2 and CXCL3. We concluded that TiO₂ NPs enter the cell via EGFR-associated endocytosis, followed by activation of the EGFR/ERK/ELK signaling pathway, which finally induces NF-κB. No changes in inflammatory response are observed in Caco-2 cells exposed to 32 nm and 490 nm TiO₂ particles.

HER2 induced EMT and tumorigenicity in breast epithelial progenitor cells is inhibited by coexpression of EGFR

OpenAIRE

Ingthorsson, Saevar; Andersen, K; Hilmarsdóttir, Bylgja; Mælandsmo, Gunhild M; Magnusson, Magnus Karl; Gudjonsson, Thorarinn

2015-01-01

The members of the epidermal growth factor receptor (EGFR) kinase family are important players in breast morphogenesis and cancer. EGFR2/HER2 and EGFR expression have a prognostic value in certain subtypes of breast cancer such as HER2-amplified, basal-like and luminal type B. Many clinically approved small molecular inhibitors and monoclonal antibodies have been designed to target HER2, EGFR or both. There is, however, still limited knowledge on how the two receptors are expressed in normal ...

Neratinib: an oral, irreversible dual EGFR/HER2 inhibitor for breast and non-small cell lung cancer.

Science.gov (United States)

Bose, Prithviraj; Ozer, Howard

2009-11-01

The revolutionary success of imatinib, a specific inhibitor of the BCR-ABL tyrosine kinase (TK) in the treatment of chronic myelogenous leukemia ushered in the era of targeted therapies in cancer. The erythroblastic leukemia viral oncogene homolog family of receptor TKs, to which EGFR (HER1) and human epidermal growth factor receptor 2 (HER2)/neu TKs belong, has been implicated in a variety of cancers, and several agents that inhibit these TKs are in clinical use, with many more in various stages of development. To summarize current knowledge about neratinib (HKI-272), an oral, irreversible dual inhibitor of EGFR and HER2 and to define its future clinical role, especially in the context of related agents that are either available or in the pipeline. A Medline search using Pubmed was conducted using the keywords neratinib, HKI-272, EGFR, HER2, lapatinib, trastuzumab, erlotinib, gefitinib, cetuximab and panitumumab. Relevant abstracts presented at the American Society of Clinical Oncology and San Antonio Breast Cancer Symposium meetings were also reviewed. Both preclinical and human studies have shown that neratinib has promising activity in both advanced breast cancer and NSCLC with an acceptable safety profile. The data support its continued clinical development.

Molecular imaging reveals elevated VEGFR-2 expression in retinal capillaries in diabetes: a novel biomarker for early diagnosis

OpenAIRE

Sun, Dawei; Nakao, Shintaro; Xie, Fang; Zandi, Souska; Bagheri, Abouzar; Kanavi, Mozhgan Rezaei; Samiei, Shahram; Soheili, Zahra-Soheila; Frimmel, Sonja; Zhang, Zhongyu; Ablonczy, Zsolt; Ahmadieh, Hamid; Hafezi-Moghadam, Ali

2014-01-01

Diabetic retinopathy (DR) is a microvascular complication of diabetes and a leading cause of vision loss. Biomarkers and methods for early diagnosis of DR are urgently needed. Using a new molecular imaging approach, we show up to 94% higher accumulation of custom designed imaging probes against vascular endothelial growth factor receptor 2 (VEGFR-2) in retinal and choroidal vessels of diabetic animals (P

(3,5-Dimethylpyrazol-1-yl-[4-(1-phenyl-1H-pyrazolo[3,4-d]pyrimidin-4-ylaminophenyl]methanone

Directory of Open Access Journals (Sweden)

Rania B. Bakr

2016-11-01

Full Text Available In an attempt to enhance cytotoxic activity of pyrazolo[3,4-d]pyrimidine core, we synthesized (3,5-dimethylpyrazol-1-yl-[4-(1-phenyl-1H-pyrazolo[3,4-d]pyrimidin-4-ylaminophenyl]methanone (4 by reacting 4-(1-phenyl-1H-pyrazolo[3,4-d]pyrimidin-4-ylaminobenzohydrazide (3 with acetylacetone. Antiproliferative activity of this compound was screened against breast (MCF-7, colon (HCT-116, and liver (HEPG-2 cancer cell lines. The tested compound exhibited cytotoxic activity with IC50 = 5.00–32.52 μM. Moreover, inhibitory activity of this compound was evaluated against the epidermal growth factor receptor (EGFR, the fibroblast growth factor receptor (FGFR, the insulin receptor (IR, and the vascular endothelial growth factor receptor (VEGFR. This target compound showed potent inhibitory activity, especially against FGFR with IC50 = 5.18 μM.

Adaptor protein containing PH domain, PTB domain and leucine zipper (APPL1) regulates the protein level of EGFR by modulating its trafficking

International Nuclear Information System (INIS)

Lee, Jae-Rin; Hahn, Hwa-Sun; Kim, Young-Hoon; Nguyen, Hong-Hoa; Yang, Jun-Mo; Kang, Jong-Sun; Hahn, Myong-Joon

2011-01-01

Highlights: ► APPL1 regulates the protein level of EGFR in response to EGF stimulation. ► Depletion of APPL1 accelerates the movement of EGF/EGFR from the cell surface to the perinuclear region in response to EGF. ► Knockdown of APPL1 enhances the activity of Rab5. -- Abstract: The EGFR-mediated signaling pathway regulates multiple biological processes such as cell proliferation, survival and differentiation. Previously APPL1 (adaptor protein containing PH domain, PTB domain and leucine zipper 1) has been reported to function as a downstream effector of EGF-initiated signaling. Here we demonstrate that APPL1 regulates EGFR protein levels in response to EGF stimulation. Overexpression of APPL1 enhances EGFR stabilization while APPL1 depletion by siRNA reduces EGFR protein levels. APPL1 depletion accelerates EGFR internalization and movement of EGF/EGFR from cell surface to the perinuclear region in response to EGF treatment. Conversely, overexpression of APPL1 decelerates EGFR internalization and translocation of EGF/EGFR to the perinuclear region. Furthermore, APPL1 depletion enhances the activity of Rab5 which is involved in internalization and trafficking of EGFR and inhibition of Rab5 in APPL1-depleted cells restored EGFR levels. Consistently, APPL1 depletion reduced activation of Akt, the downstream signaling effector of EGFR and this is restored by inhibition of Rab5. These findings suggest that APPL1 is required for EGFR signaling by regulation of EGFR stabilities through inhibition of Rab5.

Antitumor efficacy of triple monoclonal antibody inhibition of epidermal growth factor receptor (EGFR) with MM151 in EGFR-dependent and in cetuximab-resistant human colorectal cancer cells

Science.gov (United States)

Napolitano, Stefania; Martini, Giulia; Martinelli, Erika; Della Corte, Carminia Maria; Morgillo, Floriana; Belli, Valentina; Cardone, Claudia; Matrone, Nunzia; Ciardiello, Fortunato; Troiani, Teresa

2017-01-01

Purpose We investigated the effect of triple monoclonal antibody inhibition of EGFR to overcome acquired resistance to first generation of anti-EGFR inhibitors. Experimental design MM151 is a mixture of three different monoclonal IgG1 antibodies directed toward three different, non-overlapping, epitopes of the EGFR. We performed an in vivo study by using human CRC cell lines (SW48, LIM 1215 and CACO2) which are sensitive to EGFR inhibitors, in order to evaluate the activity of MM151 as compared to standard anti-EGFR mAbs, such as cetuximab, as single agent or in a sequential strategy of combination MM151 with irinotecan (induction therapy) followed by MM151 with a selective MEK1/2 inhibitor (MEKi) (maintenance therapy). Furthermore, the ability of MM151 to overcome acquired resistance to cetuximab has been also evaluated in cetuximab-refractory CRC models. Results MM151 shown stronger antitumor activity as compared to cetuximab. The maintenance treatment with MM151 plus MEKi resulted the most effective therapeutic modality. In fact, this combination caused an almost complete suppression of tumor growth in SW48, LIM 1215 and CACO2 xenografts model at 30 week. Moreover, in this treatment group, mice with no evidence of tumor were more than double as compared to single agent treated mice. Its superior activity has also been demonstrated, in cetuximab-refractory CRC models. Conclusions These results provide experimental evidence that more efficient and complete EGFR blockade may determine better antitumor activity and could contribute to prevent and/or overcome acquired resistance to EGFR inhibitors. PMID:29137301

EGFR mutation frequency and effectiveness of erlotinib

DEFF Research Database (Denmark)

Weber, Britta; Hager, Henrik; Sorensen, Boe S

2014-01-01

mutation (S768I), and two complex mutations. Seven percent of the patients were never smokers. The differences in median progression-free survival and overall survival between the mutated group and the wild-type group were 8.0 vs. 2.5 months, p...-1 vs. 2-3) and line of treatment (1st vs. 2nd and 3rd) had no influence on outcome in EGFR-mutated patients. CONCLUSION: We found a higher frequency of EGFR mutations than expected in a cohort with less than 10% never smokers. The outcome after treatment with erlotinib was much better in patients......OBJECTIVES: In 2008, we initiated a prospective study to explore the frequency and predictive value of epidermal growth factor receptor (EGFR) mutations in an unselected population of Danish patients with non-small cell lung cancer offered treatment with erlotinib, mainly in second-line. MATERIALS...

3A.05: HYPERTENSION AND RISK OF EVENTS ASSOCIATED TO REDUCED EGFR. THE ESCARVAL-RISK STUDY.

Science.gov (United States)

Tellez-Plaza, M; Orozco-Beltran, D; Gil-Guillen, V; Navarro-Pérez, J; Pallares, V; Valls, F; Fernandez, A; Martin-Moreno, J M; Sanchis, C; Dominguez-Lucas, A; Redon, J

2015-06-01

The objective of the present study was to evaluate the potential impact of hypertension in the increased CVD risk associated with CKD in a population with at least one main CV risk factor (CVRF), hypertension, dyslipidemia or diabetes.(Figure is included in full-text article.) : 54,620 men and women aged 30 years or older with at least one of main CVRF (hypertension, diabetes mellitus and/or dyslipidemia), who attended for routine health maintenance have been selected. Patients with a history of a previous CVD event were excluded. At the time of inclusion information about CVRF and their active treatments as well as smoking habit and biochemistry lab values were collected from the EHR. Estimated glomerular filtration rate (eGFR) was calculated using the CKD-EPI. Participants were followed-up for the first episode of hospitalization for myocardial infarction or stroke and all cause of death were collected. Interaction terms for dichotomous eGFR (>=60, dislipidemia 86%, diabetes in 35.5% and obesity in 41,8%. A total of 7884 (14.4%) patients had eGFR below 60 ml/min/1.73 m2 and among them 1807 (3.3%) 45 ml/min/1.73 m2 or lower. During a time follow-up of 3.2 years, patients years exposure, 960 death were recorded. A significant increment in the risk for total mortality was observed in subjects with eGFR 45 ml/min/1.73 m2 or below adjusted for multiple potential confounders (HR 1.83, 1.28-2.62; CI 95th). In normotensive subjects the risk did not increase below 60 ml/min/1.73 m2 in contrast with the increment in hypertensives. (Figure 1 on the previous page). eGFR is a prevalent condition in patients with the main CV risk factors. eGFR below <45 ml/min/1.73 m2 increases mortality risk. Hypertension by itself had an important role in the risk of mortality in patients with low eGFR on top of other CV risk factors.

EGFR signaling in colorectal cancer: a clinical perspective

Directory of Open Access Journals (Sweden)

Saletti P

2015-01-01

Full Text Available Piercarlo Saletti,1 Francesca Molinari,2 Sara De Dosso,1 Milo Frattini2 1Oncology Institute of Southern Switzerland, Bellinzona, 2Laboratory of Molecular Pathology, Institute of Pathology, Locarno, Switzerland Abstract: Colorectal cancer (CRC remains a formidable health burden worldwide, with up to 50% of patients developing metastases during the course of their disease. This group of CRC patients, characterized by the worst prognosis, has been extensively investigated to improve their life expectancy. Main efforts, focused on the epidermal growth-factor receptor (EGFR, which plays a pivotal role in CRC pathogenesis, have led to the development and introduction in clinical practice of specific targeted therapies (ie, monoclonal antibodies. Subsequently, the scientific community has tried to identify molecular predictors of the efficacy of such therapies. However, it has become clear that EGFR alterations occurring in CRC are difficult to investigate, and therefore their predictive role is unclear. In contrast, the clinical role of two downstream members (KRAS and NRAS has been clearly demonstrated. Currently, EGFR-targeted therapies can be administered only to patients with wild-type KRAS and NRAS genes. Our review addresses the medical management of metastatic CRC. Specifically, we describe in detail the molecular biology of metastatic CRC, focusing on the EGFR signaling pathway, and we discuss the role of current and emerging related biomarkers and therapies in this field. We also summarize the clinical evidence regarding anti-EGFR monoclonal antibodies and examine potential future perspectives. Keywords: colorectal cancer, EGFR, gene mutations, cetuximab, panitumumab

Toward precision medicine with next-generation EGFR inhibitors in non-small-cell lung cancer

Directory of Open Access Journals (Sweden)

Yap TA

2014-09-01

Full Text Available Timothy A Yap,1,2 Sanjay Popat1,3 1Lung Cancer Unit, Department of Medicine, The Royal Marsden National Health Service Foundation Trust, London, United Kingdom; 2The Institute of Cancer Research, London, United Kingdom; 3National Heart and Lung Institute, London, United Kingdom Abstract: The use of genomics to discover novel targets and biomarkers has placed the field of oncology at the forefront of precision medicine. First-generation epidermal growth factor receptor (EGFR inhibitors have transformed the therapeutic landscape of EGFR mutant non-small-cell lung carcinoma through the genetic stratification of tumors from patients with this disease. Somatic EGFR mutations in lung adenocarcinoma are now well established as predictive biomarkers of response and resistance to small-molecule EGFR inhibitors. Despite early patient benefit, primary resistance and subsequent tumor progression to first-generation EGFR inhibitors are seen in 10%–30% of patients with EGFR mutant non-small-cell lung carcinoma. Acquired drug resistance is also inevitable, with patients developing disease progression after only 10–13 months of antitumor therapy. This review details strategies pursued in circumventing T790M-mediated drug resistance to EGFR inhibitors, which is the most common mechanism of acquired resistance, and focuses on the clinical development of second-generation EGFR inhibitors, exemplified by afatinib (BIBW2992. We discuss the rationale, mechanism of action, clinical efficacy, and toxicity profile of afatinib, including the LUX-Lung studies. We also discuss the emergence of third-generation irreversible mutant-selective inhibitors of EGFR and envision the future management of EGFR mutant lung adenocarcinoma. Keywords: afatinib, EGFR, erlotinib, gefitinib, LUX-Lung, NSCLC 

Src Kinase becomes preferentially associated with the VEGFR, KDR/Flk-1, following VEGF stimulation of vascular endothelial cells

Directory of Open Access Journals (Sweden)

Wang Jing

2002-12-01

Full Text Available Abstract Background The cytoplasmic tyrosine kinase, Src, has been found to play a crucial role in VEGF (vascular endothelial growth factor – dependent vascular permeability involved in angiogenesis. The two main VEGFRs present on vascular endothelial cells are KDR/Flk-1 (kinase insert domain-containing receptor/fetal liver kinase-1 and Flt-1 (Fms-like tyrosine kinase-1. However, to date, it has not been determined which VEGF receptor (VEGFR is involved in binding to and activating Src kinase following VEGF stimulation of the receptors. Results In this report, we demonstrate that Src preferentially associates with KDR/Flk-1 rather than Flt-1 in human umbilical vein endothelial cells (HUVECs, and that VEGF stimulation resulted in an increase of Src activity associated with activated KDR/Flk-1. These findings were determined through immunoprecipitation-kinase experiments and coimmunoprecipitation studies, and were further confirmed by GST-pull-down assays and Far Western studies. However, Fyn and Yes, unlike Src, were found to associate preferentially with Flt-1. Conclusions Thus, Src preferentially associates with KDR/Flk-1, rather than with Flt-1, upon VEGF stimulation in endothelial cells. Our findings further highlight the potential significance of upregulated KDR/Flk-1-associated Src activity in the process of angiogenesis, and help to elucidate more clearly the specific roles and mechanisms involving Src family tyrosine kinase in VEGF-stimulated signal transduction events.

EGFR mediates astragaloside IV-induced Nrf2 activation to protect cortical neurons against in vitro ischemia/reperfusion damages

Energy Technology Data Exchange (ETDEWEB)

Gu, Da-min [Department of Anesthesiology, Affiliated Yixing People' s Hospital, Jiangsu University, Yixing (China); Lu, Pei-Hua, E-mail: lphty1_1@163.com [Department of Medical Oncology, Wuxi People' s Hospital Affiliated to Nanjing Medical University, Wuxi (China); Zhang, Ke; Wang, Xiang [Department of Anesthesiology, Affiliated Yixing People' s Hospital, Jiangsu University, Yixing (China); Sun, Min [Department of General Surgery, Affiliated Yixing People' s Hospital, Jiangsu University, Yixing (China); Chen, Guo-Qian [Department of Clinical Laboratory, Wuxi People' s Hospital Affiliated to Nanjing Medical University, Wuxi (China); Wang, Qiong, E-mail: WangQiongprof1@126.com [Department of Clinical Laboratory, Wuxi People' s Hospital Affiliated to Nanjing Medical University, Wuxi (China)

2015-02-13

In this study, we tested the potential role of astragaloside IV (AS-IV) against oxygen and glucose deprivation/re-oxygenation (OGD/R)-induced damages in murine cortical neurons, and studied the associated signaling mechanisms. AS-IV exerted significant neuroprotective effects against OGD/R by reducing reactive oxygen species (ROS) accumulation, thereby attenuating oxidative stress and neuronal cell death. We found that AS-IV treatment in cortical neurons resulted in NF-E2-related factor 2 (Nrf2) signaling activation, evidenced by Nrf2 Ser-40 phosphorylation, and its nuclear localization, as well as transcription of antioxidant-responsive element (ARE)-regulated genes: heme oxygenase-1 (HO-1), NAD(P)H:quinone oxidoreductase 1 (NQO-1) and sulphiredoxin 1 (SRXN-1). Knockdown of Nrf2 through lentiviral shRNAs prevented AS-IV-induced ARE genes transcription, and abolished its anti-oxidant and neuroprotective activities. Further, we discovered that AS-IV stimulated heparin-binding-epidermal growth factor (HB-EGF) release to trans-activate epidermal growth factor receptor (EGFR) in cortical neurons. Blockage or silencing EGFR prevented Nrf2 activation by AS-IV, thus inhibiting AS-IV-mediated anti-oxidant and neuroprotective activities against OGD/R. In summary, AS-IV protects cortical neurons against OGD/R damages through activating of EGFR-Nrf2 signaling. - Highlights: • Pre-treatment of astragaloside IV (AS-IV) protects murine cortical neurons from OGD/R. • AS-IV activates Nrf2-ARE signaling in murine cortical neurons. • Nrf2 is required for AS-IV-mediated anti-oxidant and neuroprotective activities. • AS-IV stimulates HB-EGF release to trans-activate EGFR in murine cortical neurons. • EGFR mediates AS-IV-induced Nrf2 activation and neuroprotection against OGD/R.

EGFR mediates astragaloside IV-induced Nrf2 activation to protect cortical neurons against in vitro ischemia/reperfusion damages

International Nuclear Information System (INIS)

Gu, Da-min; Lu, Pei-Hua; Zhang, Ke; Wang, Xiang; Sun, Min; Chen, Guo-Qian; Wang, Qiong

2015-01-01

In this study, we tested the potential role of astragaloside IV (AS-IV) against oxygen and glucose deprivation/re-oxygenation (OGD/R)-induced damages in murine cortical neurons, and studied the associated signaling mechanisms. AS-IV exerted significant neuroprotective effects against OGD/R by reducing reactive oxygen species (ROS) accumulation, thereby attenuating oxidative stress and neuronal cell death. We found that AS-IV treatment in cortical neurons resulted in NF-E2-related factor 2 (Nrf2) signaling activation, evidenced by Nrf2 Ser-40 phosphorylation, and its nuclear localization, as well as transcription of antioxidant-responsive element (ARE)-regulated genes: heme oxygenase-1 (HO-1), NAD(P)H:quinone oxidoreductase 1 (NQO-1) and sulphiredoxin 1 (SRXN-1). Knockdown of Nrf2 through lentiviral shRNAs prevented AS-IV-induced ARE genes transcription, and abolished its anti-oxidant and neuroprotective activities. Further, we discovered that AS-IV stimulated heparin-binding-epidermal growth factor (HB-EGF) release to trans-activate epidermal growth factor receptor (EGFR) in cortical neurons. Blockage or silencing EGFR prevented Nrf2 activation by AS-IV, thus inhibiting AS-IV-mediated anti-oxidant and neuroprotective activities against OGD/R. In summary, AS-IV protects cortical neurons against OGD/R damages through activating of EGFR-Nrf2 signaling. - Highlights: • Pre-treatment of astragaloside IV (AS-IV) protects murine cortical neurons from OGD/R. • AS-IV activates Nrf2-ARE signaling in murine cortical neurons. • Nrf2 is required for AS-IV-mediated anti-oxidant and neuroprotective activities. • AS-IV stimulates HB-EGF release to trans-activate EGFR in murine cortical neurons. • EGFR mediates AS-IV-induced Nrf2 activation and neuroprotection against OGD/R

Quantitative PET of EGFR expression in xenograft-bearing mice using {sup 64}Cu-labeled cetuximab, a chimeric anti-EGFR monoclonal antibody

Energy Technology Data Exchange (ETDEWEB)

Cai, Weibo; Chen, Kai; He, Lina; Cao, Qizhen; Chen, Xiaoyuan [Stanford University School of Medicine, The Molecular Imaging Program at Stanford (MIPS), Department of Radiology and Bio-X Program, Stanford, CA (United States); Koong, Albert [Stanford University School of Medicine, Department of Radiation Oncology, Stanford, CA (United States)

2007-06-15

Cetuximab, a chimeric monoclonal antibody targeting epidermal growth factor receptor (EGFR) on the surface of cancer cells, was approved by the FDA to treat patients with metastatic colorectal cancer. It is currently also in advanced-stage development for the treatment of several other solid tumors. Here we report for the first time the quantitative positron emission tomography (PET) imaging of EGFR expression in xenograft-bearing mice using {sup 64}Cu-labeled cetuximab. We conjugated cetuximab with macrocyclic chelating agent 1,4,7,10-tetraazadodecane-N,N',N'',N'''-tetraacetic acid (DOTA), labeled with {sup 64}Cu, and tested the resulting {sup 64}Cu-DOTA-cetuximab in seven xenograft tumor models. The tracer uptake measured by PET was correlated with the EGFR expression quantified by western blotting. The estimated human dosimetry based on the PET data in Sprague-Dawley rats was also calculated. MicroPET imaging showed that {sup 64}Cu-DOTA-cetuximab had increasing tumor activity accumulation over time in EGFR-positive tumors but relatively low uptake in EGFR-negative tumors at all times examined (<5%ID/g). There was a good correlation (R {sup 2} = 0.80) between the tracer uptake (measured by PET) and the EGFR expression level (measured by western blotting). Human dosimetry estimation indicated that the tracer may be safely administered to human patients for tumor diagnosis, with the dose-limiting organ being the liver. The success of EGFR-positive tumor imaging using {sup 64}Cu-DOTA-cetuximab can be translated into the clinic to characterize the pharmacokinetics, to select the right population of patients for EGFR-targeted therapy, to monitor the therapeutic efficacy of anti-EGFR treatment, and to optimize the dosage of either cetuximab alone or cetuximab in combination with other therapeutic agents. (orig.)

Dual gain of HER2 and EGFR gene copy numbers impacts the prognosis of carcinoma ex pleomorphic adenoma.

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Nishijima, Toshimitsu; Yamamoto, Hidetaka; Nakano, Takafumi; Nakashima, Torahiko; Taguchi, Ken-ichi; Masuda, Muneyuki; Motoshita, Jun-ichi; Komune, Shizuo; Oda, Yoshinao

2015-11-01

We investigated the potential roles of HER2 and EGFR and evaluated their prognostic significance in carcinoma ex pleomorphic adenoma (CXPA). We analyzed HER2 and EGFR overexpression status using immunohistochemistry (IHC) and gene copy number gain by chromogenic in situ hybridization (CISH) in 50 cases of CXPA (40 ductal-type and 10 myoepithelial-type CXPAs). Salivary duct carcinoma was the most common histologic subtype of malignant component (n = 21). Immunohistochemistry positivity and chromogenic in situ hybridization positivity were closely correlated in both HER2 and EGFR. HER2 CISH positivity (mostly gene amplification) and EGFR CISH positivity (mostly gene high polysomy) were present in 19 (40%) and 21 (44%) cases, respectively, and were each significantly correlated with poor outcome (P = .0009 and P = .0032, respectively). Dual gain of HER2 and EGFR gene copy numbers was present in 11 cases (23%) and was the most aggressive genotype. HER2 CISH positivity was more frequently present in ductal-type CXPAs (47%) than in myoepithelial-type CXPAs (10%), whereas the prevalence of EGFR CISH positivity was similar in both histologic subtypes (42% and 50%, respectively). Our results suggest that HER2 and EGFR gene copy number gains may play an important role in the progression of CXPA, in particular ductal-type CXPAs. HER2 CISH-positive/EGFR CISH-positive tumors may be the most aggressive subgroup in CXPA. The molecular subclassification of CXPA based on the HER2 and EGFR status may be helpful for prognostic prediction and decisions regarding the choice of therapeutic strategy. Copyright © 2015 Elsevier Inc. All rights reserved.

Radiolabeling of VEGF165 with 99mTc to evaluate VEGFR expression in tumor angiogenesis.

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Galli, Filippo; Artico, Marco; Taurone, Samanta; Manni, Isabella; Bianchi, Enrica; Piaggio, Giulia; Weintraub, Bruce D; Szkudlinski, Mariusz W; Agostinelli, Enzo; Dierckx, Rudi A J O; Signore, Alberto

2017-06-01

Angiogenesis is the main process responsible for tumor growth and metastatization. The principal effector of such mechanism is the vascular endothelial growth factor (VEGF) secreted by cancer cells and other components of tumor microenvironment. Radiolabeled VEGF analogues may provide a useful tool to noninvasively image tumor lesions and evaluate the efficacy of anti-angiogenic drugs that block the VEGFR pathway. Aim of the present study was to radiolabel the human VEGF165 analogue with 99mTechnetium (99mTc) and to evaluate the expression of VEGFR in both cancer and endothelial cells in the tumor microenvironment. 99mTc-VEGF showed in vitro binding to HUVEC cells and in vivo to xenograft tumors in mice (ARO, K1 and HT29). By comparing in vivo data with immunohistochemical analysis of excised tumors we found an inverse correlation between 99mTc-VEGF165 uptake and VEGF histologically detected, but a positive correlation with VEGF receptor expression (VEGFR1). Results of our studies indicate that endogenous VEGF production by cancer cells and other cells of tumor microenvironment should be taken in consideration when performing scintigraphy with radiolabeled VEGF, because of possible false negative results due to saturation of VEGFRs.

Loss of activating EGFR mutant gene contributes to acquired resistance to EGFR tyrosine kinase inhibitors in lung cancer cells.

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Keisuke Tabara

Full Text Available Non-small-cell lung cancer harboring epidermal growth factor receptor (EGFR mutations attains a meaningful response to EGFR-tyrosine kinase inhibitors (TKIs. However, acquired resistance to EGFR-TKIs could affect long-term outcome in almost all patients. To identify the potential mechanisms of resistance, we established cell lines resistant to EGFR-TKIs from the human lung cancer cell lines PC9 and11-18, which harbored activating EGFR mutations. One erlotinib-resistant cell line from PC9 and two erlotinib-resistant cell lines and two gefitinib-resistant cell lines from 11-18 were independently established. Almost complete loss of mutant delE746-A750 EGFR gene was observed in the erlotinib-resistant cells isolated from PC9, and partial loss of the mutant L858R EGFR gene copy was specifically observed in the erlotinib- and gefitinib-resistant cells from 11-18. However, constitutive activation of EGFR downstream signaling, PI3K/Akt, was observed even after loss of the mutated EGFR gene in all resistant cell lines even in the presence of the drug. In the erlotinib-resistant cells from PC9, constitutive PI3K/Akt activation was effectively inhibited by lapatinib (a dual TKI of EGFR and HER2 or BIBW2992 (pan-TKI of EGFR family proteins. Furthermore, erlotinib with either HER2 or HER3 knockdown by their cognate siRNAs also inhibited PI3K/Akt activation. Transfection of activating mutant EGFR complementary DNA restored drug sensitivity in the erlotinib-resistant cell line. Our study indicates that loss of addiction to mutant EGFR resulted in gain of addiction to both HER2/HER3 and PI3K/Akt signaling to acquire EGFR-TKI resistance.

2-Triazenoazaindoles: α novel class of triazenes inducing transcriptional down-regulation of EGFR and HER-2 in human pancreatic cancer cells.

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Kreutzer, Jan N; Salvador, Alessia; Diana, Patrizia; Cirrincione, Girolamo; Vedaldi, Daniela; Litchfield, David W; Issinger, Olaf-Georg; Guerra, Barbara

2012-04-01

Pancreatic cancer is a complex malignancy arising from the accumulation of genetic and epigenetic defects in the affected cells. Standard chemotherapy for patients with advanced disease shows only modest effects and is associated with considerable toxicity. Overexpression or aberrant activation of members of the epidermal growth factor receptor tyrosine kinase family, which includes EGFR and HER-2, occurs frequently and is associated with multiple drug resistance and decreased patient survival. In this study, we have investigated the therapeutic potential of AS104, a novel compound of the triazene class, with potential inhibitory effects on EGFR. We found that treatment of cells with AS104 causes significant reduction of cell growth and metabolic activity in four human pancreatic cancer cell lines. Furthermore, we show that the AS104-mediated induction of apoptotic cell death is associated with stimulation of autophagy in a dose-dependent manner. Treatment of cells with AS104 results in significant down-regulation of EGFR and HER-2 expression and activity and subsequent inhibition of downstream signaling proteins. Quantitative RT-PCR analysis and assays with proteasome inhibitors revealed that AS104 regulates the expression of EGFR and HER-2 at the transcriptional level. These findings provide for the first time experimental evidence for efficacy of AS104 in the simultaneous transcriptional repression of EGFR and HER-2 genes and suggest that AS104 may have therapeutic potential in the treatment of pancreatic cancers that express high levels of the aforementioned receptor tyrosine kinases.

2-Triazenoazaindoles: A novel class of triazenes inducing transcriptional down-regulation of EGFR and HER-2 in human pancreatic cancer cells

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KREUTZER, JAN N.; SALVADOR, ALESSIA; DIANA, PATRIZIA; CIRRINCIONE, GIROLAMO; VEDALDI, DANIELA; LITCHFIELD, DAVID W.; ISSINGER, OLAF-GEORG; GUERRA, BARBARA

2012-01-01

Pancreatic cancer is a complex malignancy arising from the accumulation of genetic and epigenetic defects in the affected cells. Standard chemotherapy for patients with advanced disease shows only modest effects and is associated with considerable toxicity. Overexpression or aberrant activation of members of the epidermal growth factor receptor tyrosine kinase family, which includes EGFR and HER-2, occurs frequently and is associated with multiple drug resistance and decreased patient survival. In this study, we have investigated the therapeutic potential of AS104, a novel compound of the triazene class, with potential inhibitory effects on EGFR. We found that treatment of cells with AS104 causes significant reduction of cell growth and metabolic activity in four human pancreatic cancer cell lines. Furthermore, we show that the AS104-mediated induction of apoptotic cell death is associated with stimulation of autophagy in a dose-dependent manner. Treatment of cells with AS104 results in significant down-regulation of EGFR and HER-2 expression and activity and subsequent inhibition of downstream signaling proteins. Quantitative RT-PCR analysis and assays with proteasome inhibitors revealed that AS104 regulates the expression of EGFR and HER-2 at the transcriptional level. These findings provide for the first time experimental evidence for efficacy of AS104 in the simultaneous transcriptional repression of EGFR and HER-2 genes and suggest that AS104 may have therapeutic potential in the treatment of pancreatic cancers that express high levels of the aforementioned receptor tyrosine kinases. PMID:22134789

Fluctuations in eGFR in relation to unenhanced and enhanced MRI and CT outpatients

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Azzouz, Manal, E-mail: manalazzouz@gmail.com [Department of Diagnostic Radiology, Copenhagen University Hospital Herlev, Herlev Ringvej 75, DK 2730 Herlev (Denmark); Rømsing, Janne [Department of Drug Design and Pharmacology, University of Copenhagen, Universitetsparken 2, DK-2100 Copenhagen Ø (Denmark); Thomsen, Henrik S. [Department of Diagnostic Radiology, Copenhagen University Hospital Herlev, Herlev Ringvej 75, DK 2730 Herlev (Denmark)

2014-06-15

Objective: To study fluctuations in estimated glomerular filtration rate (eGFR) in relation to contrast medium (CM) enhanced magnetic resonance imaging (MRI) and computed tomography (CT) compared to control groups in outpatients. Materials and methods: eGFR was determined right before the imaging procedure and three days later at the department or at the patient's home. The iodine-based and gadolinium-based contrast media were the same as used for all other examinations at the department. Results: A total of 716 patients completed the study. There was a statistically significant, but not clinically relevant rise in eGFR after three days in all four groups. The average eGFR variation was 4.8 ml/min/1.73 m{sup 2}. There were large variations in eGFR between the two measurements in 45.8% of the patients as they had a change greater than ±10 ml/min/1.73 m{sup 2}. Only three patients fulfilled the contrast-induced nephropathy (CIN) requirement when the definition s-creatinine ≥44 μmol/l (0.5 mg/dl) was used. Conclusions: eGFR in outpatients undergoing MRI or CT did vary independently of whether the patient received contrast or not. The findings probably reflect the natural variations in s-creatinine levels. This should be taken into consideration when CIN is studied.

Fluctuations in eGFR in relation to unenhanced and enhanced MRI and CT outpatients

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Azzouz, Manal; Rømsing, Janne; Thomsen, Henrik S.

2014-01-01

Objective: To study fluctuations in estimated glomerular filtration rate (eGFR) in relation to contrast medium (CM) enhanced magnetic resonance imaging (MRI) and computed tomography (CT) compared to control groups in outpatients. Materials and methods: eGFR was determined right before the imaging procedure and three days later at the department or at the patient's home. The iodine-based and gadolinium-based contrast media were the same as used for all other examinations at the department. Results: A total of 716 patients completed the study. There was a statistically significant, but not clinically relevant rise in eGFR after three days in all four groups. The average eGFR variation was 4.8 ml/min/1.73 m 2 . There were large variations in eGFR between the two measurements in 45.8% of the patients as they had a change greater than ±10 ml/min/1.73 m 2 . Only three patients fulfilled the contrast-induced nephropathy (CIN) requirement when the definition s-creatinine ≥44 μmol/l (0.5 mg/dl) was used. Conclusions: eGFR in outpatients undergoing MRI or CT did vary independently of whether the patient received contrast or not. The findings probably reflect the natural variations in s-creatinine levels. This should be taken into consideration when CIN is studied

Chlorpyrifos promotes colorectal adenocarcinoma H508 cell growth through the activation of EGFR/ERK1/2 signaling pathway but not cholinergic pathway.

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Suriyo, Tawit; Tachachartvanich, Phum; Visitnonthachai, Daranee; Watcharasit, Piyajit; Satayavivad, Jutamaad

2015-12-02

Aside from the effects on neuronal cholinergic system, epidemiological studies suggest an association between chlorpyrifos (CPF) exposure and cancer risk. This in vitro study examined the effects of CPF and its toxic metabolite, chlorpyrifos oxon (CPF-O), on the growth of human colorectal adenocarcinoma H508, colorectal adenocarcinoma HT-29, normal colon epithelial CCD841, liver hepatocellular carcinoma HepG2, and normal liver hepatocyte THLE-3 cells. The results showed that CPF (5-100 μM) concentration-dependently increased viability of H508 and CCD841 cells in serum-free conditions. This increasing trend was not found in HT-29, HepG2 and THLE-3 cells. In contrast, CPF-O (50-100 μM) reduced the viability of all cell lines. Cell cycle analysis showed the induction of cells in the S phase, and EdU incorporation assay revealed the induction of DNA synthesis in CPF-treated H508 cells indicating that CPF promotes cell cycle progression. Despite the observation of acetylcholinesterase activity inhibition and reactive oxygen species (ROS) generation, atropine (a non-selective muscarinic acetylcholine receptor antagonist) and N-acetylcysteine (a potent antioxidant) failed to inhibit the growth-promoting effect of CPF. CPF increased the phosphorylation of epidermal growth factor receptor (EGFR) and its downstream effector, extracellular signal regulated kinase (ERK1/2), in H508 cells. AG-1478 (a specific EGFR tyrosine kinase inhibitor) and U0126 (a specific MEK inhibitor) completely mitigated the growth promoting effect of CPF. Altogether, these results suggest that EGFR/ERK1/2 signaling pathway but not cholinergic pathway involves in CPF-induced colorectal adenocarcinoma H508 cell growth. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Lipopolysaccharide induces VCAM-1 expression and neutrophil adhesion to human tracheal smooth muscle cells: Involvement of Src/EGFR/PI3-K/Akt pathway

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Lin, W.-N.; Luo, S.-F.; Wu, C.-B.; Lin, C.-C.; Yang, C.-M.

2008-01-01

In our previous study, LPS has been shown to induce vascular cell adhesion molecule-1(VCAM-1) expression through MAPKs and NF-κB in human tracheal smooth muscle cells (HTSMCs). In addition to these pathways, the non-receptor tyrosine kinases (Src), EGF receptor (EGFR), and phosphatidylinositol 3-kinase (PI3K) have been shown to be implicated in the expression of several inflammatory target proteins. Here, we reported that LPS-induced up-regulation of VCAM-1 enhanced the adhesion of neutrophils onto HTSMC monolayer, which was inhibited by LY294002 and wortmannin. LPS stimulated phosphorylation of protein tyrosine kinases including Src, PYK2, and EGFR, which were further confirmed using specific anti-phospho-Src, PYK2, or EGFR Ab, respectively, revealed by Western blotting. LPS-stimulated Src, PYK2, EGFR, and Akt phosphorylation and VCAM-1 expression were attenuated by the inhibitors of Src (PP1), EGFR (AG1478), PI3-K (LY294002 and wortmannin), and Akt (SH-5), respectively, or transfection with siRNAs of Src or Akt and shRNA of p110. LPS-induced VCAM-1 expression was also blocked by pretreatment with curcumin (a p300 inhibitor) or transfection with p300 siRNA. LPS-stimulated Akt activation translocated into nucleus and associated with p300 and VCAM-1 promoter region was further confirmed by immunofluorescence, immunoprecipitation, and chromatin immunoprecipitation assays. This association of Akt and p300 to VCAM-1 promoter was inhibited by pretreatment with PP1, AG1478, wortmannin, and SH-5. LPS-induced p300 activation enhanced VCAM-1 promoter activity and VCAM-1 mRNA expression. These results suggested that in HTSMCs, Akt phosphorylation mediated through transactivation of Src/PYK2/EGFR promoted the transcriptional p300 activity and eventually led to VCAM-1 expression induced by LPS

Metaplastic Breast Cancer and EGFR Expression

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Nilufer Avci

2014-03-01

Full Text Available Aim: Metaplastic breast cancer has poor prognosis and is usually triple negative. Although it is morphologically more heterogeneous than triple negative breast cancers, expression profile is more homogeneous. In this study, we investigated our metaplastic breast cancer cases regarding their pathology and clinical characteristics. Material and Method: 16 metaplastic breast cancer cases from four different center were included in the study. Pathology and clinical characteristics of the cases were evaluated retrospectively. Results: All the cases are female and median age is 48 (39-45. Tumor is commonly localized to the outer quadrant and mean diameter of the mass is 37.5 (15-100 mm. Tumor diameter is ≤20 mm in 3 (15.8%, >20-≤50 mm in 11 (57.9% and >50 mm in 3 (10.51% of the cases. Only 4 (16.1% patients have axillary lymph node involvement. When considering histological subtypes, five of the cases has squamous cell, five of them has spindle cell, one of them has mucoepidermoid, and in five cases the subtype was not identified. Considering hormone receptor status ER and PR was negative in 78.9%, 63.2% respectively. HER2 protein expression was positive by immunohistochemical staining in 1 (5.3% case. CK5/6 and CK17 was both positive in 7 (36.8% cases. EGFR expression was positive in 4 (21.1% cases, was negative in 5 (26.3% cases and not identified in 7 (36.8% cases. Three of the cases were offered neoadjuvant chemotherapy. As neoadjuvant chemotherapy, anthracycline and taxane combination (n:2 TAC, n:1 AC-paclitaxel was preferred. Mean follow-up was 41 months. Mean survival was 42.4 months in EGFR negative patients and 47.5 months in EGFR positive patients. This difference was not statistically significant. During follow-up 3 cases had recurrence. Discussion: EGFR expression is seen in metaplastic breast cancer. Although EGFR expression is related to poor prognosis, it is not a predictive marker. Therefore, predictive molecular markers are

The Use of EGFR Tyrosine Kinase Inhibitors in EGFR Wild-Type Non-Small-Cell Lung Cancer.

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Stinchcombe, Thomas E

2016-04-01

The objective response rate and progression-free survival observed with epidermal growth factor receptor tyrosine kinase inhibitors (EGFR TKIs) in patients with metastatic epidermal growth factor receptor (EGFR) wild-type non-small cell lung cancer (NSCLC) are modest. The adverse events associated with EGFR TKIs are manageable but they must be considered in the context of the limited efficacy. The development of anti-PD-1 immunotherapy as second-line therapy has reduced the role of EGFR TKIs in EGFR wild-type NSCLC. Recently, there has been increased recognition of the benefit of the earlier integration of palliative care and symptom management, and this is reasonable alternative to treatment with an EGFR TKI for many patients. My practice pattern for patients with EGFR wild-type NSCLC is platinum-based chemotherapy as first-line therapy, immunotherapy as second-line therapy, and single-agent chemotherapy as third-line therapy for patients with preserved performance status who want to pursue further therapy. Only a small proportion of patients are eligible for fourth-line therapy, and I prefer to enroll them in clinical trials rather than use EGFR TKIs. I suspect that the use of EGFR TKIs in clinical use and as a comparator arm for clinical trials will continue to decline over the next several years.

Synthesis of 6-acrylamido-4-(2-[18F]fluoroanilino)quinazoline: Aprospective irreversible EGFR binding probe

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Vasdev, Neil; Dorff, Peter N.; Gibbs, Andrew R.; Nandanan,Erathodiyil; Reid, Leanne M.; O' Neil, James P.; VanBrocklin, Henry F.

2004-03-30

Acrylamido-quinazolines substituted at the 6-position bindirreversibly to the intracellular ATP binding domain of the epidermalgrowth factor receptor (EGFR). A general route was developed forpreparing 6-substituted-4-anilinoquinazolines from [18F]fluoroanilinesfor evaluation as EGFR targeting agents with PET. By a cyclizationreaction, 2-[18F]fluoroaniline was reacted withN'-(2-cyano-4-nitrophenyl)-N,N-dimethylimidoformamide to produce6-nitro-4-(2-[18F]fluoroanilino)quinazoline in 27.5 percentdecay-corrected radiochemical yield. Acid mediated tin chloride reductionof the nitro group was achieved in 5 min (80 percent conversion) andsubsequent acylation with acrylic acid gave6-acrylamido-4-(2-[18F]fluoroanilino)quinazoline in 8.5 percentdecay-corrected radiochemical yield, from starting fluoride, in less than2 hours.

ETS1 mediates MEK1/2-dependent overexpression of cancerous inhibitor of protein phosphatase 2A (CIP2A in human cancer cells.

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Anchit Khanna

2011-03-01

Full Text Available EGFR-MEK-ERK signaling pathway has an established role in promoting malignant growth and disease progression in human cancers. Therefore identification of transcriptional targets mediating the oncogenic effects of the EGFR-MEK-ERK pathway would be highly relevant. Cancerous inhibitor of protein phosphatase 2A (CIP2A is a recently characterized human oncoprotein. CIP2A promotes malignant cell growth and is over expressed at high frequency (40-80% in most of the human cancer types. However, the mechanisms inducing its expression in cancer still remain largely unexplored. Here we present systematic analysis of contribution of potential gene regulatory mechanisms for high CIP2A expression in cancer. Our data shows that evolutionary conserved CpG islands at the proximal CIP2A promoter are not methylated both in normal and cancer cells. Furthermore, sequencing of the active CIP2A promoter region from altogether seven normal and malignant cell types did not reveal any sequence alterations that would increase CIP2A expression specifically in cancer cells. However, treatment of cancer cells with various signaling pathway inhibitors revealed that CIP2A mRNA expression was sensitive to inhibition of EGFR activity as well as inhibition or activation of MEK-ERK pathway. Moreover, MEK1/2-specific siRNAs decreased CIP2A protein expression. Series of CIP2A promoter-luciferase constructs were created to identify proximal -27 to -107 promoter region responsible for MEK-dependent stimulation of CIP2A expression. Additional mutagenesis and chromatin immunoprecipitation experiments revealed ETS1 as the transcription factor mediating stimulation of CIP2A expression through EGFR-MEK pathway. Thus, ETS1 is probably mediating high CIP2A expression in human cancers with increased EGFR-MEK1/2-ERK pathway activity. These results also suggest that in addition to its established role in invasion and angiogenesis, ETS1 may support malignant cellular growth via regulation of

Ubiquitin ligase Cbl-b is involved in icotinib (BPI-2009H)-induced apoptosis and G1 phase arrest of EGFR mutation-positive non-small-cell lung cancer.

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Mu, Xiaodong; Zhang, Ye; Qu, Xiujuan; Hou, Kezuo; Kang, Jian; Hu, Xuejun; Liu, Yunpeng

2013-01-01

Epidermal growth factor receptor (EGFR) is one of the most promising targets for non-small-cell lung cancer (NSCLC). Icotinib, a highly selective EGFR tyrosine kinase inhibitor (EGFR-TKI), has shown promising clinical efficacy and safety in patients with NSCLC. The exact molecular mechanism of icotinib remains unclear. In this study, we first investigated the antiproliferative effect of icotinib on NSCLC cells. Icotinib significantly inhibited proliferation of the EGFR-mutated lung cancer HCC827 cells. The IC50 values at 48 and 72 h were 0.67 and 0.07 μ M, respectively. Flow cytometric analysis showed that icotinib caused the G1 phase arrest and increased the rate of apoptosis in HCC827 cells. The levels of cyclin D1 and cyclin A2 were decreased. The apoptotic process was associated with activation of caspase-3, -8, and poly(ADP-ribose) polymerase (PARP). Further study revealed that icotinib inhibited phosphorylation of EGFR, Akt, and extracellular signal-regulated kinase. In addition, icotinib upregulated ubiquitin ligase Cbl-b expression. These observations suggest that icotinib-induced upregulation of Cbl-b is responsible, at least in part, for the antitumor effect of icotinib via the inhibition of phosphoinositide 3-kinase (PI3K)/Akt and mitogen-activated protein kinase pathways in EGFR-mutated NSCLC cells.

SMOC Binds to Pro-EGF, but Does Not Induce Erk Phosphorylation via the EGFR.

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Thomas, J Terrig; Chhuy-Hy, Lina; Andrykovich, Kristin R; Moos, Malcolm

2016-01-01

In an attempt to identify the cell-associated protein(s) through which SMOC (Secreted Modular Calcium binding protein) induces mitogen-activated protein kinase (MAPK) signaling, the epidermal growth factor receptor (EGFR) became a candidate. However, although in 32D/EGFR cells, the EGFR was phosphorylated in the presence of a commercially available human SMOC-1 (hSMOC-1), only minimal phosphorylation was observed in the presence of Xenopus SMOC-1 (XSMOC-1) or human SMOC-2. Analysis of the commercial hSMOC-1 product demonstrated the presence of pro-EGF as an impurity. When the pro-EGF was removed, only minimal EGFR activation was observed, indicating that SMOC does not signal primarily through EGFR and its receptor remains unidentified. Investigation of SMOC/pro-EGF binding affinity revealed a strong interaction that does not require the C-terminal extracellular calcium-binding (EC) domain of SMOC or the EGF domain of pro-EGF. SMOC does not appear to potentiate or inhibit MAPK signaling in response to pro-EGF, but the interaction could provide a mechanism for retaining soluble pro-EGF at the cell surface.

Sphingosine 1-Phosphate Activation of EGFR As a Novel Target for Meningitic Escherichia coli Penetration of the Blood-Brain Barrier

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Wang, Xiangru; Maruvada, Ravi; Morris, Andrew J.; Liu, Jun O.; Baek, Dong Jae; Kim, Kwang Sik

2016-01-01

Central nervous system (CNS) infection continues to be an important cause of mortality and morbidity, necessitating new approaches for investigating its pathogenesis, prevention and therapy. Escherichia coli is the most common Gram-negative bacillary organism causing meningitis, which develops following penetration of the blood–brain barrier (BBB). By chemical library screening, we identified epidermal growth factor receptor (EGFR) as a contributor to E. coli invasion of the BBB in vitro. Here, we obtained the direct evidence that CNS-infecting E. coli exploited sphingosine 1-phosphate (S1P) for EGFR activation in penetration of the BBB in vitro and in vivo. We found that S1P was upstream of EGFR and participated in EGFR activation through S1P receptor as well as through S1P-mediated up-regulation of EGFR-related ligand HB-EGF, and blockade of S1P function through targeting sphingosine kinase and S1P receptor inhibited EGFR activation, and also E. coli invasion of the BBB. We further found that both S1P and EGFR activations occurred in response to the same E. coli proteins (OmpA, FimH, NlpI), and that S1P and EGFR promoted E. coli invasion of the BBB by activating the downstream c-Src. These findings indicate that S1P and EGFR represent the novel host targets for meningitic E. coli penetration of the BBB, and counteracting such targets provide a novel approach for controlling E. coli meningitis in the era of increasing resistance to conventional antibiotics. PMID:27711202

EGFR kinase-dependent and kinase-independent roles in clear cell renal cell carcinoma.

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Cossu-Rocca, Paolo; Muroni, Maria R; Sanges, Francesca; Sotgiu, Giovanni; Asunis, Anna; Tanca, Luciana; Onnis, Daniela; Pira, Giovanna; Manca, Alessandra; Dore, Simone; Uras, Maria G; Ena, Sara; De Miglio, Maria R

2016-01-01

Epidermal growth factor receptor (EGFR) is associated with progression of many epithelial malignancies and represents a significant therapeutic target. Although clear cell renal cell carcinoma (CCRCC) has been widely investigated for EGFR molecular alterations, genetic evidences of EGFR gene activating mutations and/or gene amplification have been rarely confirmed in the literature. Therefore, until now EGFR-targeted therapies in clinical trials have been demonstrated unsuccessful. New evidence has been given about the interactions between EGFR and the sodium glucose co-transporter-1 (SGLT1) in maintaining the glucose basal intracellular level to favour cancer cell growth and survival; thus a new functional role may be attributed to EGFR, regardless of its kinase activity. To define the role of EGFR in CCRCC an extensive investigation of genetic changes and functional kinase activities was performed in a series of tumors by analyzing the EGFR mutational status and expression profile, together with the protein expression of downstream signaling pathways members. Furthermore, we investigated the co-expression of EGFR and SGLT1 proteins and their relationships with clinic-pathological features in CCRCC. EGFR protein expression was identified in 98.4% of CCRCC. Furthermore, it was described for the first time that SGLT1 is overexpressed in CCRCC (80.9%), and that co-expression with EGFR is appreciable in 79.4% of the tumours. Moreover, the activation of downstream EGFR pathways was found in about 79.4% of SGLT1-positive CCRCCs. The mutational status analysis of EGFR failed to demonstrate mutations on exons 18 to 24 and the presence of EGFR-variantIII (EGFRvIII) in all CCRCCs analyzed. FISH analysis revealed absence of EGFR amplification, and high polysomy of chromosome 7. Finally, the EGFR gene expression profile showed gene overexpression in 38.2% of CCRCCs. Our study contributes to define the complexity of EGFR role in CCRCC, identifying its bivalent kinase

EGFR and KRAS mutation coexistence in lung adenocarcinomas

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Vitor Manuel Leitão de Sousa

2015-04-01

Full Text Available Lung cancer is one of the most common causes of cancer deaths. The development of EGFR targeted therapies, including monoclonal antibodies and tyrosine kinase inhibitors have generated an interest in the molecular characterization of these tumours. KRAS mutations are associated with resistance to EGFR TKIs. EGFR and KRAS mutations have been considered as mutually exclusive. This paper presents three bronchial-pulmonary carcinomas, two adenocarcinomas and one pleomorphic sarcomatoid carcinoma, harboring EGFR and KRAS mutations. Case 1 corresponded to an adenocarcinoma with EGFR exon 21 mutation (L858R and KRAS codon 12 point mutation (G12V; case 2, a  mucinous adenocarcinoma expressed coexistence of EGFR exon 21 mutation (L858R and KRAS codon 12 point mutation (G12V; and case 3 a sarcomatoid carcinoma with EGFR exon 19 deletion – del 9bp and KRAS codon 12 point mutation (G12C - cysteine. Based on our experience and on the literature, we conclude that EGFR and KRAS mutations can indeed coexist in the same bronchial-pulmonary carcinoma, either in the same histological type or in different patterns. The biological implications of this coexistence are still poorly understood mainly because these cases are not frequent or currently searched. It is therefore necessary to study larger series of cases with the two mutations to better understand the biological, clinical and therapeutic implications.

EGFR Mutation Status in Uighur Lung Adenocarcinoma Patients

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Li SHAN

2013-02-01

Full Text Available Background and objective Epidermal growth factor receptor (EGFR, a transmembrane protein, is a member of the tyrosine kinase family. Gefitinib, an EGFR tyrosine-kinase inhibitors, has shown a high response rate in the treatment of lung cancer in patients with EGFR mutation. However, significant differences in EGFR mutations exist among different ethnic groups. The aim of this study is to investigate the prevalence of EGFR mutations in Uighur lung adenocarcinoma patients by using a rapid and sensitive detection method and to analyze EGFR mutation differences compared with Han lung adenocarcinoma patients. Methods We examined lung adenocarcinoma tissues from 138 patients, including 68 Uighur lung adenocarcinoma patients and 70 Han lung adenocarcinoma patients, for EGFR mutations in exons 18, 19, 20, and 21 by using the amplification refractory mutation system (ARMS PCR method. The mutation differences between Uighur and Han lung adenocarcinoma were compared by using the chi-square test method. Results EGFR mutations were detected in 43 (31.2% of the 138 lung adenocarcinoma patients. EGFR mutations were detected in 11 (16.2% of the 68 Uighur lung adenocarcinoma patients and in 32 (45.7% of the 70 Han lung adenocarcinoma patients. Significant differences were observed in the EGFR mutations between Uighur lung adenocarcinoma patients and Han lung adenocarcinoma patients (P<0.001. Conclusion Our results indicate that the EGFR mutation in Uighur lung adenocarcinoma patients (16.2% is significantly lower than that in Han lung adenocarcinoma patients (45.7%.

Osimertinib and Necitumumab in Treating Patients With EGFR-Mutant Stage IV or Recurrent Non-small Cell Lung Cancer Who Have Progressed on a Previous EGFR Tyrosine Kinase Inhibitor

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2018-03-07

EGFR Exon 19 Deletion Mutation; EGFR Exon 20 Insertion Mutation; EGFR NP_005219.2:p.G719X; EGFR NP_005219.2:p.L858R; EGFR NP_005219.2:p.L861Q; EGFR NP_005219.2:p.T790M; EGFR T790M Mutation Negative; Recurrent Non-Small Cell Lung Carcinoma; Stage IV Non-Small Cell Lung Cancer AJCC v7

Inhibition of Metastatic Potential in Breast Carcinoma In Vivo and In Vitro through Targeting VEGFRs and FGFRs

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Ming-Hsien Chien

2013-01-01

Full Text Available Angiogenesis and lymphangiogenesis are considered to play key roles in tumor metastasis. Targeting receptor tyrosine kinases essentially involved in the angiogenesis and lymphangiogenesis would theoretically prevent cancer metastasis. However, the optimal multikinase inhibitor for metastasis suppression has yet to be developed. In this study, we evaluated the effect of NSTPBP 0100194-A (194-A, a multikinase inhibitor of vascular endothelial growth factor receptors (VEGFRs/fibroblast growth factor receptors (FGFRs, on lymphangiogenesis and angiogenesis in a mammary fat pad xenograft model of the highly invasive breast cancer cell line 4T1-Luc+. We investigated the biologic effect of 194-A on various invasive breast cancer cell lines as well as endothelial and lymphatic endothelial cells. Intriguingly, we found that 194-A drastically reduced the formation of lung, liver, and lymph node metastasis of 4T1-Luc+ and decreased primary tumor growth. This was associated with significant reductions in intratumoral lymphatic vessel length (LVL and microvessel density (MVD. 194-A blocked VEGFRs mediated signaling on both endothelial and lymphatic endothelial cells. Moreover, 194-A significantly inhibited the invasive capacity induced by VEGF-C or FGF-2 in vitro in both 4T1 and MDA-MB231 cells. In conclusion, these experimental results demonstrate that simultaneous inhibition of VEGFRs/FGFRs kinases may be a promising strategy to prevent breast cancer metastasis.

Toroidal-spiral particles for codelivery of anti-VEGFR-2 antibody and irinotecan: a potential implant to hinder recurrence of glioblastoma multiforme.

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Sharma, Vishal; Köllmer, Melanie; Szymusiak, Magdalena; Nitsche, Ludwig C; Gemeinhart, Richard A; Liu, Ying

2014-03-10

Heterogeneous toroidal-spiral particles (TSPs) were generated by polymer droplet sedimentation, interaction, and cross-linking. TSPs provide a platform for encapsulation and release of multiple compounds of different sizes and physicochemical properties. As a model system, we demonstrate the encapsulation and independently controlled release of an anti-VEGFR-2 antibody and irinotecan for the treatment of glioblastoma multiforme. The anti-VEGFR-2 antibody was released from the TS channels and its binding to HUVECs was confirmed by confocal microscopy and flow cytometry, suggesting active antibody encapsulation and release. Irinotecan, a small molecule drug, was released from the dense polymer matrix of poly(ethylene glycol) diacrylate (MW ~ 700 g/mol; PEGDA 700). Released irinotecan inhibited the proliferation of U251 malignant glioma cells. Since the therapeutic compounds are released through different pathways, specifically diffusion through the polymer matrix versus TS channels, the release rate can be controlled independently through the design of the structure and material of particle components.

Specific Inhibition of the VEGFR-3 Tyrosine Kinase by SAR131675 Reduces Peripheral and Tumor Associated Immunosuppressive Myeloid Cells

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Espagnolle, Nicolas; Barron, Pauline; Mandron, Marie; Blanc, Isabelle; Bonnin, Jacques; Agnel, Magali; Kerbelec, Erwan; Herault, Jean Pascal; Savi, Pierre; Bono, Françoise; Alam, Antoine

2014-01-01

Myeloid derived suppressor cells (MDSCs) and tumor-associated macrophages (TAMs) represent prominent components in cancer progression. We previously showed that inhibition of the VEGFR-3 pathway by SAR131675 leads to reduction of TAM infiltration and tumor growth. Here, we found that treatment with SAR131675 prevents the accumulation of immunosuppressive blood and splenic MDSCs which express VEGFR-3, in 4T1 tumor bearing mice. Moreover we showed that soluble factors secreted by tumor cells promote MDSCs proliferation and differentiation into M2 polarized F4/80+ macrophages. In addition, cell sorting and transcriptomic analysis of tumor infiltrating myeloid cells revealed the presence of a heterogeneous population that could be divided into 3 subpopulations: (i) immature cells with a MDSC phenotype (GR1+/CD11b+/F4/80 − ); (ii) “immuno-incompetent” macrophages (F4/80 high /CD86 neg /MHCII Low ) strongly expressing M2 markers such as Legumain, CD206 and Mgl1/2 and (iii) “immuno-competent”-M1 like macrophages (F4/80 Low /CD86 + /MHCII High ). SAR131675 treatment reduced MDSCs in lymphoid organs as well as F4/80 High populations in tumors. Interestingly, in the tumor SAR131675 was able to increase the immunocompetent M1 like population (F4/80 low ). Altogether these results demonstrate that the specific VEGFR-3 inhibitor SAR131675 exerts its anti tumoral activity by acting on different players that orchestrate immunosuppression and cancer progression in a tumoral context: MDSCs in peripheral lymphoid organs and TAMs infiltrating the tumor

Fluorescent Affibody Molecule Administered In Vivo at a Microdose Level Labels EGFR Expressing Glioma Tumor Regions.

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de Souza, Ana Luiza Ribeiro; Marra, Kayla; Gunn, Jason; Samkoe, Kimberley S; Hoopes, P Jack; Feldwisch, Joachim; Paulsen, Keith D; Pogue, Brian W

2017-02-01

Fluorescence guidance in surgical oncology provides the potential to realize enhanced molecular tumor contrast with dedicated targeted tracers, potentially with a microdose injection level. For most glioma tumors, the blood brain barrier is compromised allowing some exogenous drug/molecule delivery and accumulation for imaging. The aberrant overexpression and/or activation of epidermal growth factor receptor (EGFR) is associated with many types of cancers, including glioblastoma, and so the use of a near-infrared (NIR) fluorescent molecule targeted to the EGFR receptor provides the potential for improving tumor contrast during surgery. Fluorescently labeled affibody molecule (ABY-029) has high EGFR affinity and high potential specificity with reasonably fast plasma clearance. In this study, ABY-29 was evaluated in glioma versus normal brain uptake from intravenous injection at a range of doses, down to a microdose injection level. Nude rats were inoculated with the U251 human glioma cell line in the brain. Tumors were allowed to grow for 3-4 weeks. ABY-029 fluorescence ex vivo imaging of brain slices was acquired at different time points (1-48 h) and varying injection doses from 25 to 122 μg/kg (from human protein microdose equivalent to five times microdose levels). The tumor was most clearly visualized at 1-h post-injection with 8- to 16-fold average contrast relative to normal brain. However, the tumor still could be identified after 48 h. In all cases, the ABY-029 fluorescence appeared to localize preferentially in EGFR-positive regions. Increasing the injected dose from a microdose level to five times, a microdose level increased the signal by 10-fold, and the contrast was from 8 to 16, showing that there was value in doses slightly higher than the microdose restriction. Normal tissue uptake was found to be affected by the tumor size, indicating that edema was a likely factor affecting the expected tumor to normal tissue contrast. These results suggest

Activation of EGFR and ERBB2 by Helicobacter pylori Results in Survival of Gastric Epithelial Cells with DNA Damage

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Chaturvedi, Rupesh; Asim, Mohammad; Piazuelo, M. Blanca; Yan, Fang; Barry, Daniel P.; Sierra, Johanna Carolina; Delgado, Alberto G.; Hill, Salisha; Casero, Robert A.; Bravo, Luis E.; Dominguez, Ricardo L.; Correa, Pelayo; Polk, D. Brent; Washington, M. Kay; Rose, Kristie L.; Schey, Kevin L.; Morgan, Douglas R.; Peek, Richard M.; Wilson, Keith T.

2014-01-01

BACKGROUND & AIMS The gastric cancer-causing pathogen Helicobacter pylori upregulates spermine oxidase (SMOX) in gastric epithelial cells, causing oxidative stress-induced apoptosis and DNA damage. A subpopulation of SMOXhigh cells are resistant to apoptosis, despite their high levels of DNA damage. Because epidermal growth factor receptor (EGFR) activation can regulate apoptosis, we determined its role in SMOX-mediated effects. METHODS SMOX, apoptosis, and DNA damage were measured in gastric epithelial cells from H pylori-infected Egfrwa5 mice (which have attenuated EGFR activity), Egfr wild-type mice, or in infected cells incubated with EGFR inhibitors or deficient in EGFR. Phosphoproteomic analysis was performed. Two independent tissue microarrays containing each stage of disease, from gastritis to carcinoma, and gastric biopsies from Colombian and Honduran cohorts were analyzed by immunohistochemistry. RESULTS SMOX expression and DNA damage were decreased, and apoptosis increased in H pylori-infected Egfrwa5 mice. H pylori-infected cells with deletion or inhibition of EGFR had reduced levels of SMOX, DNA damage, and DNA damagehigh apoptosislow cells. Phosphoproteomic analysis revealed increased EGFR and ERBB2 signaling. Immunoblot analysis demonstrated the presence of a phosphorylated (p)EGFR–ERBB2 heterodimer and pERBB2; knockdown of ErbB2 facilitated apoptosis of DNA damagehigh apoptosislow cells. SMOX was increased in all stages of gastric disease, peaking in tissues with intestinal metaplasia, whereas pEGFR, pEGFR–ERBB2, and pERBB2 were increased predominantly in tissues demonstrating gastritis or atrophic gastritis. Principal component analysis separated gastritis tissues from patients with cancer vs those without cancer. pEGFR, pEGFR–ERBB2, pERBB2, and SMOX were increased in gastric samples from patients whose disease progressed to intestinal metaplasia or dysplasia, compared with patients whose disease did not progress. CONCLUSIONS In an analysis

Sequence analysis of the Ras-MAPK pathway genes SOS1, EGFR & GRB2 in silver foxes (Vulpes vulpes): candidate genes for hereditary hyperplastic gingivitis.

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Clark, Jo-Anna B J; Tully, Sara J; Dawn Marshall, H

2014-12-01

Hereditary hyperplastic gingivitis (HHG) is an autosomal recessive disease that presents with progressive gingival proliferation in farmed silver foxes. Hereditary gingival fibromatosis (HGF) is an analogous condition in humans that is genetically heterogeneous with several known autosomal dominant loci. For one locus the causative mutation is in the Son of sevenless homologue 1 (SOS1) gene. For the remaining loci, the molecular mechanisms are unknown but Ras pathway involvement is suspected. Here we compare sequences for the SOS1 gene, and two adjacent genes in the Ras pathway, growth receptor bound protein 2 (GRB2) and epidermal growth factor receptor (EGFR), between HHG-affected and unaffected foxes. We conclude that the known HGF causative mutation does not cause HHG in foxes, nor do the coding regions or intron-exon boundaries of these three genes contain any candidate mutations for fox gum disease. Patterns of molecular evolution among foxes and other mammals reflect high conservation and strong functional constraints for SOS1 and GRB2 but reveal a lineage-specific pattern of variability in EGFR consistent with mutational rate differences, relaxed functional constraints, and possibly positive selection.

Acquired resistance of EGFR-mutant lung adenocarcinomas to afatinib plus cetuximab is associated with activation of mTORC1

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Pirazzoli, Valentina; Nebhan, Caroline; Song, Xiaoling; Wurtz, Anna; Walther, Zenta; Cai, Guoping; Zhao, Zhongming; Jia, Peilin; de Stanchina, Elisa; Shapiro, Erik M.; Gale, Molly; Yin, Ruonan; Horn, Leora; Carbone, David P.; Stephens, Philip J; Miller, Vincent; Gettinger, Scott; Pao, William; Politi, Katerina

2014-01-01

SUMMARY Patients with EGFR-mutant lung adenocarcinomas (LUADs) who initially respond to first-generation TKIs develop resistance to these drugs. A combination of the irreversible TKI afatinib and the EGFR antibody cetuximab can be used to overcome resistance to first-generation TKIs; however, resistance to this drug combination eventually emerges. We identified activation of the mTORC1 signaling pathway as a mechanism of resistance to dual inhibition of EGFR in mouse models. Addition of rapamycin reversed resistance in vivo. Analysis of afatinib+cetuximab-resistant biopsy specimens revealed the presence of genomic alterations in genes that modulate mTORC1 signaling including NF2 and TSC1. These findings pinpoint enhanced mTORC1 activation as a mechanism of resistance to afatinib+cetuximab and identify genomic mechanisms that lead to activation of this pathway, revealing a potential therapeutic strategy for treating patients with resistance to these drugs. PMID:24813888

DSGOST inhibits tumor growth by blocking VEGF/VEGFR2-activated angiogenesis.

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Choi, Hyeong Sim; Lee, Kangwook; Kim, Min Kyoung; Lee, Kang Min; Shin, Yong Cheol; Cho, Sung-Gook; Ko, Seong-Gyu

2016-04-19

Tumor growth requires a process called angiogenesis, a new blood vessel formation from pre-existing vessels, as newly formed vessels provide tumor cells with oxygen and nutrition. Danggui-Sayuk-Ga-Osuyu-Saenggang-Tang (DSGOST), one of traditional Chinese medicines, has been widely used in treatment of vessel diseases including Raynaud's syndrome in Northeast Asian countries including China, Japan and Korea. Therefore, we hypothesized that DSGOST might inhibit tumor growth by targeting newly formed vessels on the basis of its historical prescription. Here, we demonstrate that DSGOST inhibits tumor growth by inhibiting VEGF-induced angiogenesis. DSGOST inhibited VEGF-induced angiogenic abilities of endothelial cells in vitro and in vivo, which resulted from its inhibition of VEGF/VEGFR2 interaction. Furthermore, DSGOST attenuated pancreatic tumor growth in vivo by reducing angiogenic vessel numbers, while not affecting pancreatic tumor cell viability. Thus, our data conclude that DSGOST inhibits VEGF-induced tumor angiogenesis, suggesting a new indication for DSGOST in treatment of cancer.

Dependence of Relative Expression of NTR1 and EGFR on Cell Density and Extracellular pH in Human Pancreatic Cancer Cell Lines

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Olszewski-Hamilton, Ulrike; Hamilton, Gerhard

2011-01-01

Pancreatic adenocarcinoma is a devastating disease characterized by early dissemination and poor prognosis. These solid tumors express receptors for neuropeptides like neurotensin (NT) or epidermal growth factor (EGF) and exhibit acidic regions when grown beyond a certain size. We previously demonstrated increases in intracellular Ca 2+ levels, intracellular pH and interleukin-8 (IL-8) secretion in BxPC-3 and PANC-1 pancreatic cancer cells in response to a stable NT analog. The present study aimed at investigation of the dependence of the relative expression of NT receptor 1 (NTR1) and EGFR in BxPC-3 and MIA PaCa-2 cells on cell density and extracellular pH (pH e ). MTT assays revealed the NTR1 inhibitor SR 142948-sensitive Lys 8 -ψ-Lys 9 NT (8–13)-induced proliferation in BxPC-3 and PANC-1 cells. Confluent cultures of BxPC3 and HT-29 lines exhibited highest expression of NTR1 and lowest of EGFR and expression of NTR1 was maximal at slightly acidic pH e . IL-8 production was stimulated by Lys 8 -ψ-Lys 9 NT (8–13) and even enhanced at both acidic and alkaline pH e in BxPC-3 and PANC-1 cells. In conclusion, our in vitro study suggests that one contributing factor to the minor responses obtained with EGFR-directed therapy may be downregulation of this receptor in tumor cell aggregates, possibly resulting in acquisition of a more aggressive phenotype via other growth factor receptors like NTR1

Lung cancer with concurrent EGFR mutation and ROS1 rearrangement: a case report and review of the literature

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Zhu YC

2016-07-01

Full Text Available You-cai Zhu,1,2,* Chun-wei Xu,3,* Xiao-qian Ye,4 Man-xiang Yin,4 Jin-xian Zhang,2 Kai-qi Du,2 Zhi-hao Zhang,2 Jian Hu1 1Department of Thoracic Surgery, The First Affiliated Hospital of Medical School of Zhejiang University, Hangzhou, 2Department of Thoracic Surgery, Chinese People’s Armed Police Force, Zhejiang Corps Hospital, Jiaxing, Zhejiang, 3Department of Pathology, Affiliated Hospital of Academy of Military Medical Sciences, Beijing, 4Department of Pathology, Chinese People’s Armed Police Force, Zhejiang Corps Hospital, Jiaxing, Zhejiang, People’s Republic of China *These authors contributed equally to this work Abstract: ROS1 rearrangement has recently emerged as a new molecular subtype in non-small cell lung cancer, and is predominantly found in lung adenocarcinomas compared with other oncogenes such as EGFR, KRAS, or ALK. Patients who have both mutations are extremely rare. Here we report a 50-year-old female diagnosed with adenocarcinoma with sarcomatoid differentiation, who was shown to have EGFR and ROS1 mutations. The patient was treated surgically and received three cycles of adjuvant postoperative chemotherapy. In addition, we reviewed the previously reported cases and related literature. This presentation will provide further understanding of the underlying molecular biology and optimal treatment for non-small cell lung cancer patients with more than one driver mutation. Keywords: non-small cell lung cancer, EGFR gene mutation, ROS1 fusion gene

Customized treatment in non-small-cell lung cancer based on EGFR mutations and BRCA1 mRNA expression.

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Rafael Rosell

Full Text Available BACKGROUND: Median survival is 10 months and 2-year survival is 20% in metastatic non-small-cell lung cancer (NSCLC treated with platinum-based chemotherapy. A small fraction of non-squamous cell lung cancers harbor EGFR mutations, with improved outcome to gefitinib and erlotinib. Experimental evidence suggests that BRCA1 overexpression enhances sensitivity to docetaxel and resistance to cisplatin. RAP80 and Abraxas are interacting proteins that form complexes with BRCA1 and could modulate the effect of BRCA1. In order to further examine the effect of EGFR mutations and BRCA1 mRNA levels on outcome in advanced NSCLC, we performed a prospective non-randomized phase II clinical trial, testing the hypothesis that customized therapy would confer improved outcome over non-customized therapy. In an exploratory analysis, we also examined the effect of RAP80 and Abraxas mRNA levels. METHODOLOGY/PRINCIPAL FINDINGS: We treated 123 metastatic non-squamous cell lung carcinoma patients using a customized approach. RNA and DNA were isolated from microdissected specimens from paraffin-embedded tumor tissue. Patients with EGFR mutations received erlotinib, and those without EGFR mutations received chemotherapy with or without cisplatin based on their BRCA1 mRNA levels: low, cisplatin plus gemcitabine; intermediate, cisplatin plus docetaxel; high, docetaxel alone. An exploratory analysis examined RAP80 and Abraxas expression. Median survival exceeded 28 months for 12 patients with EGFR mutations, and was 11 months for 38 patients with low BRCA1, 9 months for 40 patients with intermediate BRCA1, and 11 months for 33 patients with high BRCA1. Two-year survival was 73.3%, 41.2%, 15.6% and 0%, respectively. Median survival was influenced by RAP80 expression in the three BRCA1 groups. For example, for patients with both low BRCA1 and low RAP80, median survival exceeded 26 months. RAP80 was a significant factor for survival in patients treated according to BRCA1

Granulocyte-Colony Stimulating Factor Receptor, Tissue Factor, and VEGF-R Bound VEGF in Human Breast Cancer In Loco.

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Wojtukiewicz, Marek Z; Sierko, Ewa; Skalij, Piotr; Kamińska, Magda; Zimnoch, Lech; Brekken, Ralf A; Thorpe, Philip E

2016-01-01

Doxorubicin and docetaxel-based chemotherapy regimens used in breast cancer patients are associated with high risk of febrile neutropenia (FN). Granulocyte colony-stimulating factors (G-CSF) are recommended for both treating and preventing chemotherapy-induced neutropenia. Increased thrombosis incidence in G-CSF treated patients was reported; however, the underlying mechanisms remain unclear. The principal activator of blood coagulation in cancer is tissue factor (TF). It additionally contributes to cancer progression and stimulates angiogenesis. The main proangiogenic factor is vascular endothelial growth factor (VEGF). The aim of the study was to evaluate granulocyte-colony stimulating factor receptor (G-CSFR), tissue factor (TF) expression and vascular endothelial growth factor receptor (VEGF-R) bound VEGF in human breast cancer in loco. G-CSFR, TF and VEGFR bound VEGF (VEGF: VEGFR) were assessed in 28 breast cancer tissue samples. Immunohistochemical (IHC) methodologies according to ABC technique and double staining IHC procedure were employed utilizing antibodies against G-CSFR, TF and VEGF associated with VEGFR (VEGF: VEGFR). Expression of G-CSFR was demonstrated in 20 breast cancer tissue specimens (71%). In 6 cases (21%) the expression was strong (IRS 9-12). Strong expression of TF was observed in all investigated cases (100%). Moreover, expression of VEGF: VEGFR was visualized in cancer cells (IRS 5-8). No presence of G-CSFR, TF or VEGF: VEGFR was detected on healthy breast cells. Double staining IHC studies revealed co-localization of G-CSFR and TF, G-CSFR and VEGF: VEGFR, as well as TF and VEGF: VEGFR on breast cancer cells and ECs. The results of the study indicate that GCSFR, TF and VEGF: VEGFR expression as well as their co-expression might influence breast cancer biology, and may increase thromboembolic adverse events incidence.

Association and interaction between dietary pattern and VEGF receptor-2 (VEGFR2) gene polymorphisms on blood lipids in Chinese Malaysian and Japanese adults.

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Yap, Roseline Wai Kuan; Shidoji, Yoshihiro; Hon, Wei Min; Masaki, Motofumi

2012-01-01

Dietary pattern and genetic predisposition of each population have different impacts on lifestyle-related chronic diseases. This study was conducted to evaluate the association and interaction between dietary patterns and VEGFR2 or KDR gene polymorphisms on physical and biochemical risk factors of cardiovascular disease in two Asian populations (179 Chinese Malaysian and 136 Japanese adults). Dietary patterns were constructed from food frequency questionnaire using factor analysis. Genotyping of rs1870377 and rs2071559 was performed by real-time PCR using TaqMan probes. Physical measurements: body mass index, systolic and diastolic blood pressures and biochemical parameters: glycated hemoglobin A1c and blood lipids (total cholesterol, triglycerides, LDL-cholesterol, HDL-cholesterol and total cholesterol/HDL-C ratio) were measured. Two dietary patterns were extracted for: Japanese ('Japanese diet' and 'Western diet') and Chinese Malaysians ('Balanced diet'; and 'Meat, rice and noodles diet'). In Japanese, 'Western Diet' and rs2071559 were associated with LDL-C and HDL-C, respectively. In Chinese Malaysians, 'Meat, rice and noodles diet' was asso-ciated with triglycerides, HDL-C and total cholesterol/HDL ratio while rs1870377 and rs2071559 were associated with total cholesterol and/or LDL-C. The interaction between 'Western Diet' and rs2071559 in Japanese and 'Meat, rice and noodles diet' and rs1870377 in Malaysians had significant effects on blood lipids after adjusting for confounders. The association and interaction of dietary patterns and VEGFR2 gene polymorphisms on blood lipids differ between Chinese Malaysian and Japanese subjects by either decreasing or increasing the risk of cardiovascular disease.

Contribution of EGFR and ErbB-3 Heterodimerization to the EGFR Mutation-Induced Gefitinib- and Erlotinib-Resistance in Non-Small-Cell Lung Carcinoma Treatments.

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Debby D Wang

Full Text Available EGFR mutation-induced drug resistance has become a major threat to the treatment of non-small-cell lung carcinoma. Essentially, the resistance mechanism involves modifications of the intracellular signaling pathways. In our work, we separately investigated the EGFR and ErbB-3 heterodimerization, regarded as the origin of intracellular signaling pathways. On one hand, we combined the molecular interaction in EGFR heterodimerization with that between the EGFR tyrosine kinase and its inhibitor. For 168 clinical subjects, we characterized their corresponding EGFR mutations using molecular interactions, with three potential dimerization partners (ErbB-2, IGF-1R and c-Met of EGFR and two of its small molecule inhibitors (gefitinib and erlotinib. Based on molecular dynamics simulations and structural analysis, we modeled these mutant-partner or mutant-inhibitor interactions using binding free energy and its components. As a consequence, the mutant-partner interactions are amplified for mutants L858R and L858R_T790M, compared to the wild type EGFR. Mutant delL747_P753insS represents the largest difference between the mutant-IGF-1R interaction and the mutant-inhibitor interaction, which explains the shorter progression-free survival of an inhibitor to this mutant type. Besides, feature sets including different energy components were constructed, and efficient regression trees were applied to map these features to the progression-free survival of an inhibitor. On the other hand, we comparably examined the interactions between ErbB-3 and its partners (EGFR mutants, IGF-1R, ErbB-2 and c-Met. Compared to others, c-Met shows a remarkably-strong binding with ErbB-3, implying its significant role in regulating ErbB-3 signaling. Moreover, EGFR mutants corresponding to poor clinical outcomes, such as L858R_T790M, possess lower binding affinities with ErbB-3 than c-Met does. This may promote the communication between ErbB-3 and c-Met in these cancer cells. The

Ubiquitin Ligase Cbl-b Is Involved in Icotinib (BPI-2009H-Induced Apoptosis and G1 Phase Arrest of EGFR Mutation-Positive Non-Small-Cell Lung Cancer

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Xiaodong Mu

2013-01-01

Full Text Available Epidermal growth factor receptor (EGFR is one of the most promising targets for non-small-cell lung cancer (NSCLC. Icotinib, a highly selective EGFR tyrosine kinase inhibitor (EGFR-TKI, has shown promising clinical efficacy and safety in patients with NSCLC. The exact molecular mechanism of icotinib remains unclear. In this study, we first investigated the antiproliferative effect of icotinib on NSCLC cells. Icotinib significantly inhibited proliferation of the EGFR-mutated lung cancer HCC827 cells. The IC50 values at 48 and 72 h were 0.67 and 0.07 μM, respectively. Flow cytometric analysis showed that icotinib caused the G1 phase arrest and increased the rate of apoptosis in HCC827 cells. The levels of cyclin D1 and cyclin A2 were decreased. The apoptotic process was associated with activation of caspase-3, -8, and poly(ADP-ribose polymerase (PARP. Further study revealed that icotinib inhibited phosphorylation of EGFR, Akt, and extracellular signal-regulated kinase. In addition, icotinib upregulated ubiquitin ligase Cbl-b expression. These observations suggest that icotinib-induced upregulation of Cbl-b is responsible, at least in part, for the antitumor effect of icotinib via the inhibition of phosphoinositide 3-kinase (PI3K/Akt and mitogen-activated protein kinase pathways in EGFR-mutated NSCLC cells.

GU81, a VEGFR2 antagonist peptoid, enhances the anti-tumor activity of doxorubicin in the murine MMTV-PyMT transgenic model of breast cancer

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Lynn, Kristi D; Udugamasooriya, D Gomika; Roland, Christina L; Castrillon, Diego H; Kodadek, Thomas J; Brekken, Rolf A

2010-01-01

Vascular endothelial growth factor (VEGF) is a primary stimulant of angiogenesis under physiological and pathological conditions. Anti-VEGF therapy is a clinically proven strategy for the treatment of a variety of cancers including colon, breast, lung, and renal cell carcinoma. Since VEGFR2 is the dominant angiogenic signaling receptor, it has become an important target in the development of novel anti-angiogenic therapies. We have reported previously the development of an antagonistic VEGFR2 peptoid (GU40C4) that has promising anti-angiogenic activity in vitro and in vivo. In the current study, we utilize a derivative of GU40C4, termed GU81 in therapy studies. GU81 was tested alone or in combination with doxorubicin for in vivo efficacy in the MMTV-PyMT transgenic model of breast cancer. The derivative GU81 has increased in vitro efficacy compared to GU40C4. Single agent therapy (doxorubicin or GU81 alone) had no effect on tumor weight, histology, tumor fat content, or tumor growth index. However, GU81 is able to significantly to reduce total vascular area as a single agent. GU81 used in combination with doxorubicin significantly reduced tumor weight and growth index compared to all other treatment groups. Furthermore, treatment with combination therapy significantly arrested tumor progression at the premalignant stage, resulting in increased tumor fat content. Interestingly, treatment with GU81 alone increased tumor-VEGF levels and macrophage infiltration, an effect that was abrogated when used in combination with doxorubicin. This study demonstrates the VEGFR2 antagonist peptoid, GU81, enhances the anti-tumor activity of doxorubicin in spontaneous murine MMTV-PyMT breast tumors

Hypoxia preconditioning of mesenchymal stromal cells enhances PC3 cell lymphatic metastasis accompanied by VEGFR-3/CCR7 activation.

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Huang, Xin; Su, Kunkai; Zhou, Limin; Shen, Guofang; Dong, Qi; Lou, Yijia; Zheng, Shu

2013-12-01

Mesenchymal stromal cells (MSCs) in bone marrow may enhance tumor metastases through the secretion of chemokines. MSCs have been reported to home toward the hypoxic tumor microenvironment in vivo. In this study, we investigated prostate cancer PC3 cell behavior under the influence of hypoxia preconditioned MSCs and explored the related mechanism of prostate cancer lymphatic metastases in mice. Transwell assays revealed that VEGF-C receptor, VEGFR-3, as well as chemokine CCL21 receptor, CC chemokine receptor 7 (CCR7), were responsible for the migration of PC3 cells toward hypoxia preconditioned MSCs. Knock-in Ccr7 in PC3 cells also improved cell migration in vitro. Furthermore, when PC3 cells were labeled using the hrGfp-lentiviral vector, and were combined with hypoxia preconditioned MSCs for xenografting, it resulted in an enhancement of lymph node metastases accompanied by up-regulation of VEGFR-3 and CCR7 in primary tumors. Both PI3K/Akt/IκBα and JAK2/STAT3 signaling pathways were activated in xenografts in the presence of hypoxia-preconditioned MSCs. Unexpectedly, the p-VEGFR-2/VEGFR-2 ratio was attenuated accompanied by decreased JAK1 expression, indicating a switching-off of potential vascular signal within xenografts in the presence of hypoxia-preconditioned MSCs. Unlike results from other studies, VEGF-C maintained a stable expression in both conditions, which indicated that hypoxia preconditioning of MSCs did not influence VEGF-C secretion. Our results provide the new insights into the functional molecular events and signalings influencing prostate tumor metastases, suggesting a hopeful diagnosis and treatment in new approaches. © 2013 Wiley Periodicals, Inc.

Serum placental growth factor, vascular endothelial growth factor, soluble vascular endothelial growth factor receptor-1 and -2 levels in periodontal disease, and adverse pregnancy outcomes.

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Sert, Tuba; Kırzıoğlu, F Yeşim; Fentoğlu, Ozlem; Aylak, Firdevs; Mungan, Tamer

2011-12-01

The aim of this study is the evaluation of levels of serum interleukin (IL)-1β, IL-6, IL-10, tumor necrosis factor (TNF)-α, vascular endothelial growth factor (VEGF), placental growth factor (PIGF), and soluble VEGF receptor (sVEGFR)-1 and -2 in the association between periodontal disease and adverse pregnancy outcomes. One hundred and nine mothers, who recently gave birth, and 51 women who were not recently pregnant, aged 18 to 35 years, were included in this study. The mothers were classified as term birth, preterm birth (PTB), and preterm low birth weight (PLBW) in respect to their gestational age and baby's birth weight. The birth mothers were grouped as having gingivitis or periodontitis. The non-pregnant group also included periodontally healthy patients. Venous blood samples were collected to evaluate serum IL-1β, IL-6, IL-10, TNF-α, VEGF, PIGF, and sVEGFR-1 and -2 levels. Mother's weight, education, and income level were significantly associated with pregnancy outcomes. Serum levels of IL-1β, TNF-α, IL-6, VEGF, and sVEGFR-1 and -2 showed an increase in significance when related to pregnancy. Whereas in the PLBW group IL-1β, VEGF, and sVEGFR-2 levels were increased, in the PTB group sVEGFR-1 levels were increased. Additionally, the patients in the PLBW group with periodontitis had higher serum levels of IL-1β, VEGF, sVEGFR-2, and IL-1β/IL-10. The serum levels of IL-1β, VEGF, and sVEGFR-1 and -2 may have a potential effect on the mechanism of the association between periodontal disease and adverse pregnancy outcomes.

Acquired Resistance of EGFR-Mutant Lung Adenocarcinomas to Afatinib plus Cetuximab Is Associated with Activation of mTORC1

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Valentina Pirazzoli

2014-05-01

Full Text Available Patients with EGFR-mutant lung adenocarcinomas (LUADs who initially respond to first-generation tyrosine kinase inhibitors (TKIs develop resistance to these drugs. A combination of the irreversible TKI afatinib and the EGFR antibody cetuximab can be used to overcome resistance to first-generation TKIs; however, resistance to this drug combination eventually emerges. We identified activation of the mTORC1 signaling pathway as a mechanism of resistance to dual inhibition of EGFR in mouse models. The addition of rapamycin reversed resistance in vivo. Analysis of afatinib-plus-cetuximab-resistant biopsy specimens revealed the presence of genomic alterations in genes that modulate mTORC1 signaling, including NF2 and TSC1. These findings pinpoint enhanced mTORC1 activation as a mechanism of resistance to afatinib plus cetuximab and identify genomic mechanisms that lead to activation of this pathway, revealing a potential therapeutic strategy for treating patients with resistance to these drugs.

Icotinib in Patients with Pretreated Advanced Esophageal Squamous Cell Carcinoma with EGFR Overexpression or EGFR Gene Amplification: A Single-Arm, Multicenter Phase 2 Study.

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Huang, J.; Fan, Q.; Lu, P.; Ying, J.; Ma, C.; Liu, W.; Liu, Y.; Tan, F.; Sun, Y

2016-01-01

INTRODUCTION: Epidermal growth factor receptor (EGFR) has been reported to be overexpressed and amplified in a high percentage of patients with esophageal squamous cell carcinoma (ESCC). The activity of icotinib, an EGFR tyrosine kinase inhibitor, was assessed in previously treated ESCC with EGFR

Sapanisertib and Osimertinib in Treating Patients With Stage IV EGFR Mutation Positive Non-small Cell Lung Cancer After Progression on a Previous EGFR Tyrosine Kinase Inhibitor

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2018-04-25

EGFR Activating Mutation; EGFR Exon 19 Deletion Mutation; EGFR NP_005219.2:p.G719X; EGFR NP_005219.2:p.L858R; EGFR NP_005219.2:p.L861Q; EGFR T790M Mutation Negative; Recurrent Non-Small Cell Lung Carcinoma; Stage III Non-Small Cell Lung Cancer AJCC v7; Stage IIIA Non-Small Cell Lung Cancer AJCC v7; Stage IIIB Non-Small Cell Lung Cancer AJCC v7; Stage IV Non-Small Cell Lung Cancer AJCC v7

Specific Inhibition of the VEGFR-3 Tyrosine Kinase by SAR131675 Reduces Peripheral and Tumor Associated Immunosuppressive Myeloid Cells

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Espagnolle, Nicolas [UMR5273 INSERM U1031/CNRS/EFS StromaLab, Toulouse 31432 (France); Barron, Pauline; Mandron, Marie; Blanc, Isabelle; Bonnin, Jacques [Sanofi Recherche et Développement, Early to Candidate DPU, Toulouse 31036 (France); Agnel, Magali; Kerbelec, Erwan [Molecular Biology Unit, Biologics Department, Sanofi, Vitry-sur-Seine 94400 (France); Herault, Jean Pascal; Savi, Pierre; Bono, Françoise; Alam, Antoine, E-mail: antoine.alam@sanofi.com [Sanofi Recherche et Développement, Early to Candidate DPU, Toulouse 31036 (France)

2014-02-28

Myeloid derived suppressor cells (MDSCs) and tumor-associated macrophages (TAMs) represent prominent components in cancer progression. We previously showed that inhibition of the VEGFR-3 pathway by SAR131675 leads to reduction of TAM infiltration and tumor growth. Here, we found that treatment with SAR131675 prevents the accumulation of immunosuppressive blood and splenic MDSCs which express VEGFR-3, in 4T1 tumor bearing mice. Moreover we showed that soluble factors secreted by tumor cells promote MDSCs proliferation and differentiation into M2 polarized F4/80+ macrophages. In addition, cell sorting and transcriptomic analysis of tumor infiltrating myeloid cells revealed the presence of a heterogeneous population that could be divided into 3 subpopulations: (i) immature cells with a MDSC phenotype (GR1+/CD11b+/F4/80{sup −}); (ii) “immuno-incompetent” macrophages (F4/80{sup high}/CD86{sup neg}/MHCII{sup Low}) strongly expressing M2 markers such as Legumain, CD206 and Mgl1/2 and (iii) “immuno-competent”-M1 like macrophages (F4/80{sup Low}/CD86{sup +}/MHCII{sup High}). SAR131675 treatment reduced MDSCs in lymphoid organs as well as F4/80{sup High} populations in tumors. Interestingly, in the tumor SAR131675 was able to increase the immunocompetent M1 like population (F4/80{sup low}). Altogether these results demonstrate that the specific VEGFR-3 inhibitor SAR131675 exerts its anti tumoral activity by acting on different players that orchestrate immunosuppression and cancer progression in a tumoral context: MDSCs in peripheral lymphoid organs and TAMs infiltrating the tumor.

Radiosensitization of NSCLC cells by EGFR inhibition is the result of an enhanced p53-dependent G1 arrest

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Kriegs, Malte; Gurtner, Kristin; Can, Yildiz; Brammer, Ingo; Rieckmann, Thorsten; Oertel, Reinhard; Wysocki, Marek; Dorniok, Franziska; Gal, Andreas; Grob, Tobias J.; Laban, Simon; Kasten-Pisula, Ulla; Petersen, Cordula; Baumann, Michael; Krause, Mechthild; Dikomey, Ekkehard

2015-01-01

Purpose: How EGF receptor (EGFR) inhibition induces cellular radiosensitization and with that increase in tumor control is still a matter of discussion. Since EGFR predominantly regulates cell cycle and proliferation, we studied whether a G1-arrest caused by EGFR inhibition may contribute to these effects. Materials and methods: We analyzed human non-small cell lung cancer (NSCLC) cell lines either wild type (wt) or mutated in p53 (A549, H460, vs. H1299, H3122) and HCT116 cells (p21 wt and negative). EGFR was inhibited by BIBX1382BS, erlotinib or cetuximab; p21 was knocked down by siRNA. Functional endpoints analyzed were cell signaling, proliferation, G1-arrest, cell survival as well as tumor control using an A549 tumor model. Results: When combined with IR, EGFR inhibition enhances the radiation-induced permanent G1 arrest, though solely in cells with intact p53/p21 signaling. This increase in G1-arrest was always associated with enhanced cellular radiosensitivity. Strikingly, this effect was abrogated when cells were re-stimulated, suggesting the initiation of dormancy. In line with this, only a small non-significant increase in tumor control was observed for A549 tumors treated with fractionated RT and EGFR inhibition. Conclusion: For NSCLC cells increase in radiosensitivity by EGFR inhibition results from enhanced G1-arrest. However, this effect does not lead to improved tumor control because cells can be released from this arrest by re-stimulation

Genomic activation of the EGFR and HER2-neu genes in a significant proportion of invasive epithelial ovarian cancers

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Ghislain Vanessa

2008-01-01

Full Text Available Abstract Background The status of the EGFR and HER2-neu genes has not been fully defined in ovarian cancer. An integrated analysis of both genes could help define the proportion of patients that would potentially benefit from targeted therapies. Methods We determined the tumour mutation status of the entire tyrosine kinase (TK domain of the EGFR and HER2-neu genes in a cohort of 52 patients with invasive epithelial ovarian cancer as well as the gene copy number and protein expression of both genes in 31 of these patients by DGGE and direct sequecing, immunohistochemistry and Fluorescent in Situ Hybridisation (FISH. Results The EGFR was expressed in 59% of the cases, with a 2+/3+ staining intensity in 38%. HER2-neu expression was found in 35%, with a 2/3+ staining in 18%. No mutations were found in exons 18–24 of the TK domains of EGFR and HER2-neu. High polysomy of the EGFR gene was observed in 13% of the invasive epthelial cancers and amplification of the HER2-neu gene was found in 10% and correlated with a high expression level by immunohistochemistry. Mutations within the tyrosine kinase domain were not found in the entire TK domain of both genes, but have been found in very rare cases by others. Conclusion Genomic alteration of the HER2-neu and EGFR genes is frequent (25% in ovarian cancer. EGFR/HER2-neu targeted therapies should be investigated prospectively and specifically in that subset of patients.

64Cu-Labeled Trastuzumab Fab-PEG24-EGF Radioimmunoconjugates Bispecific for HER2 and EGFR: Pharmacokinetics, Biodistribution, and Tumor Imaging by PET in Comparison to Monospecific Agents.

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Kwon, Luke Yongkyu; Scollard, Deborah A; Reilly, Raymond M

2017-02-06

Heterodimerization of EGFR with HER2 coexpressed in breast cancer (BC) promotes tumor growth, and increased EGFR expression is associated with trastuzumab resistance. Our aim was to construct 64 Cu-labeled bispecific radioimmunoconjugates (bsRIC) composed of trastuzumab Fab, which binds HER2 linked through a polyethylene glycol (PEG 24 ) spacer to EGF, and to compare their pharmacokinetic, biodistribution, and tumor imaging characteristics by positron-emission tomography (PET). bsRICs were generated by linking maleimide modified trastuzumab Fab with thiolated EGF through a thioether bond. HER2 and EGFR binding were assessed in vitro in MDA-MB-231 (EGFR mod /HER2 low ), MDA-MB-468 (EGFR high /HER2 neg ), MDA-MB-231-H2N (EGFR mod /HER2 mod ), and SKOV3 (EGFR low /HER2 high ) cells by competition and saturation cell binding assays to estimate the dissociation constant (K d ). The elimination of the 64 Cu-NOTA-trastuzumab Fab-PEG 24 -EGF bsRICs from the blood of Balb/c mice was compared to monospecific 64 Cu-NOTA-trastuzumab Fab and 64 Cu-NOTA-EGF. MicroPET/CT imaging was performed in NOD/SCID mice bearing subcutaneous MDA-MB-468, MDA-MB-231/H2N, or SKOV3 human BC xenografts at 24 and 48 h postinjection (p.i.) of bsRICs. Tumor and normal tissue uptake were quantified by biodistribution studies and compared to monospecific agents. The binding of bsRICs to MDA-MB-231 cells was decreased to 24.5 ± 5.2% by excess EGF, while the binding of bsRICs to SKOV3 cells was decreased to 38.6 ± 5.4% by excess trastuzumab Fab, demonstrating specific binding to both EGFR and HER2. 64 Cu-labeled bsRICs incorporating the PEG 24 spacer were eliminated more slowly from the blood than 64 Cu-bsRICs without the PEG spacer and were cleared much more slowly than 64 Cu-NOTA-Fab or 64 Cu-NOTA-EGF. All three tumor xenografts were visualized by microPET/CT at 24 and 48 h p.i. of bsRICs. Biodistribution studies at 48 h p.i. in NOD/SCID mice with MDA-MB-231/H2N tumors demonstrated significantly

MAXIMIZATION OF DNA DAMAGE TO MGMT(+ EGFR(+ GBM CELLS USING OPTIMAL COMBINATION OF TEMOZOLOMIDE-ANTI EGFR MONOCLONAL ANTIBODY NIMOTUZUMAB

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M. A. M. Inggas

2015-09-01

Full Text Available Background: Glioblastoma multiforme (GBM is the most aggressive primary brain tumor in adultswith dismal prognosis due to the unavailability of an effective therapy. Up to now, there had been no definitive studies published on EGFR inhibition therapy as a chemosensitizer for GBM therapy using Temozolomide (TMZ. This study aims to reveal the most effective method and timing to administer TMZ-anti EGFR targeted therapy which causes maximal DNA damage on GBM cells.Methods: Various regimens of anti EGFR monoclonal antibody Nimotuzumab (NMZ was administered in different combinations with TMZ, performed on U87MG MGMT(+ EGFR(+ cells. The effectiveness of the combinations were evaluated by measuring yH2AX levels which reflects the degree of DNA damage. One-way Anova and LSD tests were performed to determine the effects of each treatment with p<0.05. Results and discussion: the mean SD of yH2AX of each treatment was: 11,90±1,25 for the control group; 29.33±1.91 for NMZ alone; 28.13±1.58 for TMZ alone; 41.53±3.51 for concurrent use; 35.67 ±2.65 for NMZ after 24 hours TMZ; 31.87±2.94 for NMZ after 48 hours TMZ; 39.57±4.2 for TMZ after 24 hours NMZ; and 35.93 ±3.56 for TMZ after 48 hours NMZ. The administration of TMZ concurrent with or after 24 hours NMZ gives the highest amount of DNA damage to GBM cells. Conclusion: The administration of Nimotuzumab targeted therapy up to 24 hours before Temozolomide chemotherapy has been proven to be effective in maximizing the amount of DNA damage done to GBM cells in vitro. 

Acrolein and thiol-reactive electrophiles suppress allergen-induced innate airway epithelial responses by inhibition of DUOX1 and EGFR.

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Danyal, Karamatullah; de Jong, Willem; O'Brien, Edmund; Bauer, Robert A; Heppner, David E; Little, Andrew C; Hristova, Milena; Habibovic, Aida; van der Vliet, Albert

2016-11-01

Acrolein is a major thiol-reactive component of cigarette smoke (CS) that is thought to contribute to increased asthma incidence associated with smoking. Here, we explored the effects of acute acrolein exposure on innate airway responses to two common airborne allergens, house dust mite and Alternaria alternata, and observed that acrolein exposure of C57BL/6 mice (5 ppm, 4 h) dramatically inhibited innate airway responses to subsequent allergen challenge, demonstrated by attenuated release of the epithelial-derived cytokines IL-33, IL-25, and IL-1α. Acrolein and other anti-inflammatory thiol-reactive electrophiles, cinnamaldehyde, curcumin, and sulforaphane, similarly inhibited allergen-induced production of these cytokines from human or murine airway epithelial cells in vitro. Based on our previous observations indicating the importance of Ca 2+ -dependent signaling, activation of the NADPH oxidase DUOX1, and Src/EGFR-dependent signaling in allergen-induced epithelial secretion of these cytokines, we explored the impact of acrolein on these pathways. Acrolein and other thiol-reactive electrophiles were found to dramatically prevent allergen-induced activation of DUOX1 as well as EGFR, and acrolein was capable of inhibiting EGFR tyrosine kinase activity via modification of C797. Biotin-labeling strategies indicated increased cysteine modification and carbonylation of Src, EGFR, as well as DUOX1, in response to acrolein exposure in vitro and in vivo, suggesting that direct alkylation of these proteins on accessible cysteine residues may be responsible for their inhibition. Collectively, our findings indicate a novel anti-inflammatory mechanism of CS-derived acrolein and other thiol-reactive electrophiles, by directly inhibiting DUOX1- and EGFR-mediated airway epithelial responses to airborne allergens. Copyright © 2016 the American Physiological Society.

HIF2α contributes to antiestrogen resistance via positive bilateral crosstalk with EGFR in breast cancer cells

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Alam, Muhammad Wasi; Persson, Camilla Ulrika; Reinbothe, Susann

2016-01-01

or inhibition of EGFR led to decreased HIF2α levels. This positive and bilateral HIF2-EGFR regulatory crosstalk promotes antiestrogen resistance and, where intrinsic hypoxic resistance exists, therapy itself may exacerbate the problem. Finally, inhibition of HIFs by FM19G11 restores antiestrogen sensitivity...

Recent Advances in Targetable Therapeutics in Metastatic Non-Squamous NSCLC

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Pranshu eBansal

2016-05-01

Full Text Available Lung adenocarcinoma is the most common subtype of non-small cell lung cancer (NSCLC. With the discovery of epidermal growth factor receptor (EGFR mutations, anaplastic lymphoma kinase (ALK rearrangements and effective targeted therapies, therapeutic options are expanding for patients with lung adenocarcinoma. Here, we review novel therapies in non-squamous NSCLC, which are directed against oncogenic targets, including EGFR, ALK, ROS1, BRAF, MET, human epidermal growth factor receptor 2 (HER2, vascular endothelial growth factor receptor 2 (VEGFR2, RET and NTRK. With the rapidly evolving molecular testing and development of new targeted agents, our ability to further personalize therapy in non-squamous NSCLC is rapidly expanding.

Conservation of protein abundance patterns reveals the regulatory architecture of the EGFR-MAPK pathway

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Shi, T.; Niepel, M.; McDermott, J. E.; Gao, Y.; Nicora, C. D.; Chrisler, W. B.; Markillie, L. M.; Petyuk, V. A.; Smith, R. D.; Rodland, K. D.; Sorger, P. K.; Qian, W. -J.; Wiley, H. S.

2016-07-12

It is not known whether cancer cells generally show quantitative differences in the expression of signaling pathway proteins that could dysregulate signal transduction. To explore this issue, we first defined the primary components of the EGF-MAPK pathway in normal human mammary epithelial cells, identifying 16 core proteins and 10 feedback regulators. We then quantified their absolute abundance across a panel of normal and cancer cell lines. We found that core pathway proteins were expressed at very similar levels across all cell types. In contrast, the EGFR and transcriptionally controlled feedback regulators were expressed at highly variable levels. The absolute abundance of most core pathway proteins was between 50,000- 70,000 copies per cell, but the adaptors SOS1, SOS2, and GAB1 were found at far lower levels (2,000-5,000 per cell). MAPK signaling showed saturation in all cells between 3,000-10,000 occupied EGFR, consistent with the idea that low adaptor levels limit signaling. Our results suggest that the core MAPK pathway is essentially invariant across different cell types, with cell- specific differences in signaling likely due to variable levels of feedback regulators. The low abundance of adaptors relative to the EGFR could be responsible for previous observation of saturable signaling, endocytosis, and high affinity EGFR.

[Regulation on EGFR function via its interacting proteins and its potential application].

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Zheng, Jun-Fang; Chen, Hui-Min; He, Jun-Qi

2013-12-01

Epidermal growth factor receptor (EGFR) is imptortant for cell activities, oncogenesis and cell migration, and EGFR inhibitor can treat cancer efficiently, but its side effects, for example, in skin, limited its usage. On the other hand, EGFR interacting proteins may also lead to oncogenesis and its interacting protein as drug targets can avoid cutaneous side effect, which implies possibly a better outcome and life quality of cancer patients. For the multiple EGFR interaction proteins, B1R enhances Erk/MAPK signaling, while PTPN12, Kek1, CEACAM1 and NHERF repress Erk/MAPK signaling. CaM may alter charge of EGFR juxamembrane domain and regulate activation of PI3K/Akt and PLC-gamma/PKC. STAT1, STAT5b are widely thought to be activated by EGFR, while there is unexpectedly inhibiting sequence within EGFR to repress the activity of STATs. LRIG1 and ACK1 enhance the internalization and degration of EGFR, while NHERF and HIP1 repress it. In this article, proteins interacting with EGFR, their interacting sites and their regulation on EGFR signal transduction will be reviewed.

Detection of EGFR and COX-2 Expression by Immunohistochemical Method on a Tissue Microarray Section in Lung Cancer and Biological Significance

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Xinyun WANG

2010-02-01

Full Text Available Background and objective Epidermal growth factor receptor (EGFR and cyclooxygenase-2 (COX-2, which can regulate growth, invasion and metastasis of tumor through relevant signaling pathway, have been detected in a variety of solid tumors. The aim of this study is to investigate the biological significance of EGFR and COX-2 expression in lung cancer and the relationship between them. Methods The expression of EGFR and COX-2 was detected in 89 primary lung cancer tissues, 12 premaliganant lesions, 12 lymph node metastases, and 10 normal lung tissues as the control by immunohistochemical method on a tissue microarray section. Results EGFR protein was detectable in 59.6%, 41.7%, and 66.7% of primary lung cancer tissues, premalignant lesions and lymph node metastases, respectively; COX-2 protein was detectable in 52.8%, 41.7%, and 66.7% of primary lung cancer tissues, premalignant lesions and lymph node metastases, respectively, which were significantly higher than those of the control (P 0.05. COX-2 expression was related to gross type (P < 0.05. A highly positive correlation was observed between EGFR and COX-2 expression (P < 0.01. Conclusion Overexpression of EGFR and COX-2 may play an important role in the tumorgenesis, progression and malignancy of lung cancer. Detection of EGFR and COX-2 expression might be helpful to diagnosis and prognosis of lung cancer.

Design, Synthesis and Evaluation of Ribose-modified Anilinopyrimidine Derivatives as EGFR Tyrosine Kinase Inhibitors

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Hu, Xiuqin; Wang, Disha; Tong, Yi; Tong, Linjiang; Wang, Xia; Zhu, Lili; Xie, Hua; Li, Shiliang; Yang, You; Xu, Yufang

2017-11-01

The synthesis of a series of ribose-modified anilinopyrimidine derivatives was efficiently achieved by utilizing DBU or tBuOLi-promoted coupling of ribosyl alcohols with 2,4,5-trichloropyrimidine as key step. Preliminary biological evaluation of this type of compounds as new EGFR tyrosine kinase inhibitors for combating EGFR L858R/T790M mutant associated with drug resistance in the treatment of non-small cell lung cancer revealed that 3-N-acryloyl-5-O-anilinopyrimidine ribose derivative 1a possessed potent and specific inhibitory activity against EGFR L858R/T790M over WT EGFR. Based upon molecular docking studies of the binding mode between compound 1a and EGFR, the distance between the Michael receptor and the pyrimidine scaffold is considered as an important factor for the inhibitory potency and future design of selective EGFR tyrosine kinase inhibitors against EGFR L858R/T790M mutants.

Effect of Genetic African Ancestry on eGFR and Kidney Disease

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Nadkarni, Girish N.; Belbin, Gillian; Lotay, Vaneet; Wyatt, Christina; Gottesman, Omri; Bottinger, Erwin P.; Kenny, Eimear E.; Peter, Inga

2015-01-01

Self-reported ancestry, genetically determined ancestry, and APOL1 polymorphisms are associated with variation in kidney function and related disease risk, but the relative importance of these factors remains unclear. We estimated the global proportion of African ancestry for 9048 individuals at Mount Sinai Medical Center in Manhattan (3189 African Americans, 1721 European Americans, and 4138 Hispanic/Latino Americans by self-report) using genome-wide genotype data. CKD-EPI eGFR and genotypes of three APOL1 coding variants were available. In admixed African Americans and Hispanic/Latino Americans, serum creatinine values increased as African ancestry increased (per 10% increase in African ancestry, creatinine values increased 1% in African Americans and 0.9% in Hispanic/Latino Americans; P≤1x10−7). eGFR was likewise significantly associated with African genetic ancestry in both populations. In contrast, APOL1 risk haplotypes were significantly associated with CKD, eGFRblack on the basis of ≥50% African ancestry resulted in higher eGFR for 14.7% of Hispanic/Latino Americans and lower eGFR for 4.1% of African Americans, affecting CKD staging in 4.3% and 1% of participants, respectively. Reclassified individuals had electrolyte values consistent with their newly assigned CKD stage. In summary, proportion of African ancestry was significantly associated with normal-range creatinine and eGFR, whereas APOL1 risk haplotypes drove the associations with CKD. Recalculation of eGFR on the basis of genetic ancestry affected CKD staging and warrants additional investigation. PMID:25349204

Novel [99mTcN]2+ Labeled EGFR Inhibitors as Potential Radiotracers for Single Photon Emission Computed Tomography (SPECT Tumor Imaging

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Mingxia Zhao

2014-04-01

Full Text Available The epidermal growth factor receptor (EGFR is overexpressed in many cancers, including breast, ovarian, endometrial and non-small cell lung cancer. An EGFR-specific imaging agent could facilitate clinical evaluation of primary tumors or metastases. To achieve this goal, 4-(2-aminoethylamino-6,7-dimethoxyquinazoline (ADMQ was synthesized based on a 4-aminoquinazoline core and then conjugated with N-mercapto- acetylglycine (MAG and N-mercaptoacetyltriglycine (MAG3, respectively, to give compounds 1 and 2. The final complexes [99mTcN]-1 and [99mTcN]-2 were successfully obtained with radiochemical purities of >99% and >98% as measured by radio-HPLC. No decomposition of the two complexes at room temperature was observed over a period of 2 h. Their partition coefficients indicated they were hydrophilic and the electrophoresis results showed they were negatively charged. Biodistribution in tumor-bearing mice demonstrated that the two new complexes showed tumor accumulation, high tumor-tomuscle (T/M ratios and fast clearance from blood and muscle. Between the two compounds, the 99mTcN-MAG3-ADMQ ([99mTcN]-2 showed the better characteristics, with the tumor/muscle and tumor/blood ratios reached 2.11 and 1.90 at 60 min post-injection, 4.20 and 1.10 at 120 min post-injection, suggesting it could be a promising radiotracer for SPECT tumor imaging.

A pathological study on overexpression of c-erbB-2, EGFR proteins in human radiation skin ulcer

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Zhao Po; Yang Zhixiang; Wang Dewen; Li Guomin; Gao Yabin

1996-01-01

We performed an immunohistochemical study in 25 cases of human radiation skin ulcer by using c-erbB-2, Epidermal growth factor receptor (EGFR), protein antibodies and repairing method of antigen with microwave oven. The results show that the positive rate for overexpression of c-erbB-2 oncoprotein was 92.0% (23/25), and EGFR was 73.7%(14/19). The positive position for overexpression of c-crbB-2 was mainly observed on cell membrane of squamous epithelial cells and cell plasma of fibroblasts, endotheliocytes, and leiomyocytes in media and fibrocytes in adventitia of the arterioles in mesenchyme. It is suggested that the overexpression of c-erbB-2 and EGFR proteins might be related to cancer transformation and poor healing in radiation skin ulcers

Brief report: Afatinib and cetuximab in four patients with EGFR exon 20 insertion positive advanced non-small-cell lung cancer.

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van Veggel, Bianca; de Langen, Adrianus J; Hashemi, Sayed; Monkhorst, Kim; Heideman, Daniëlle A M; Thunnissen, Erik; Smit, Egbert F

2018-04-24

Epidermal growth factor receptor (EGFR) exon 20 insertions comprise 4-9% of EGFR mutated non-small-cell lung cancer (NSCLC). Despite being an oncogenic driver, they are associated with primary resistance to EGFR tyrosine kinase inhibitors (TKIs). We hypothesized that dual EGFR blockade with afatinib, an irreversible EGFR TKI, and cetuximab, a monoclonal antibody against EGFR, could induce tumor responses. Four patients with EGFR exon 20 insertion positive NSCLC were treated with afatinib 40 mg once daily and cetuximab 250-500 mg/m 2 every two weeks. All patients had stage IV adenocarcinoma of the lung harboring an EGFR exon 20 insertion mutation. Previous lines of treatment consisted of platinum doublet chemotherapy (n=4) and EGFR TKI (n=2). Three out of four patients showed a partial response according to RECIST 1.1. Median progression-free survival was 5.4 months (95% confidence interval 0.0 - 14.2 months; range 2.7 - 17.6 months). Toxicity was manageable with appropriate skin management and dose reduction being required in two patients. Dual EGFR blockade with afatinib and cetuximab may induce tumor responses in patients with EGFR exon 20 insertion positive NSCLC. Copyright © 2018. Published by Elsevier Inc.

Frequent EGFR Positivity and Overexpression in High-Grade Areas of Human MPNSTs

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Séverine Tabone-Eglinger

2008-01-01

Full Text Available Malignant peripheral nerve sheath tumours (MPNSTs are highly malignant and resistant. Transformation might implicate up regulation of epidermal growth factor receptor (EGFR. Fifty-two MPNST samples were studied for EGFR, Ki-67, p53, and survivin expression by immunohistochemistry and for EGFR amplification by in situ hybridization. Results were correlated with clinical data. EGFR RNA was also quantified by RT-PCR in 20 other MPNSTs and 14 dermal neurofibromas. Half of the patients had a neurofibromatosis type 1 (NF1. EGFR expression, detected in 86% of MPNSTs, was more frequent in NF1 specimens and closely associated with high-grade and p53-positive areas. MPNSTs expressed more EGFR transcripts than neurofibromas. No amplification of EGFR locus was observed. NF1 status was the only prognostic factor in multivariate analysis, with median survivals of 18 and 43 months for patients with or without NF1. Finally, EGFR might become a new target for MPNSTs treatment, especially in NF1-associated MPNSTs.