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Sample records for activated egfr determines

  1. EGFR Activation by Spatially Restricted Ligands

    National Research Council Canada - National Science Library

    Goodrich, Jennifer S

    2005-01-01

    ...) activity has been associated with an increased prognosis of breast cancer. During oogenesis in Drosophila melanogaster, local EGFR activation by the spatially restricted TGF alpha-like ligand, Gurken (Grk...

  2. Response to the Dorsal Anterior Gradient of EGFR Signaling in Drosophila Oogenesis Is Prepatterned by Earlier Posterior EGFR Activation

    Directory of Open Access Journals (Sweden)

    Mariana Fregoso Lomas

    2013-08-01

    Full Text Available Spatially restricted epidermal growth factor receptor (EGFR activity plays a central role in patterning the follicular epithelium of the Drosophila ovary. In midoogenesis, localized EGFR activation is achieved by the graded dorsal anterior localization of its ligand, Gurken. Graded EGFR activity determines multiple dorsal anterior fates along the dorsal-ventral axis but cannot explain the sharp posterior limit of this domain. Here, we show that posterior follicle cells express the T-box transcription factors Midline and H15, which render cells unable to adopt a dorsal anterior fate in response to EGFR activation. The posterior expression of Midline and H15 is itself induced in early oogenesis by posteriorly localized EGFR signaling, defining a feedback loop in which early induction of Mid and H15 confers a molecular memory that fundamentally alters the outcome of later EGFR signaling. Spatial regulation of the EGFR pathway thus occurs both through localization of the ligand and through localized regulation of the cellular response.

  3. Convergent Akt activation drives acquired EGFR inhibitor resistance in lung cancer

    DEFF Research Database (Denmark)

    Jacobsen, Kirstine; Bertran-Alamillo, Jordi; Molina, Miguel Angel

    2017-01-01

    Non-small-cell lung cancer patients with activating epidermal growth factor receptor (EGFR) mutations typically benefit from EGFR tyrosine kinase inhibitor treatment. However, virtually all patients succumb to acquired EGFR tyrosine kinase inhibitor resistance that occurs via diverse mechanisms....... The diversity and unpredictability of EGFR tyrosine kinase inhibitor resistance mechanisms presents a challenge for developing new treatments to overcome EGFR tyrosine kinase inhibitor resistance. Here, we show that Akt activation is a convergent feature of acquired EGFR tyrosine kinase inhibitor resistance...... phospho-Akt levels to therapeutically combat the heterogeneity of EGFR tyrosine kinase inhibitor resistance mechanisms.EGFR-mutant non-small cell lung cancer are often resistant to EGFR tyrosine kinase inhibitor treatment. In this study, the authors show that resistant tumors display high Akt activation...

  4. IMPAIRED SHP2-MEDIATED ERK ACTIVATION CONTRIBUTES TO GEFITINIB SENSITIVITY OF LUNG CANCER CELLS WITH EGFR-ACTIVATING MUTATIONS

    OpenAIRE

    Lazzara, Matthew J.; Lane, Keara; Chan, Richard; Jasper, Paul J; Yaffe, Michael B.; Sorger, Peter K.; Jacks, Tyler; Neel, Benjamin G.; Lauffenburger, Douglas A.

    2010-01-01

    Most non-small cell lung cancers (NSCLC) display elevated expression of epidermal growth factor receptor (EGFR), but response to EGFR kinase inhibitors is predominantly limited to NSCLC harboring EGFR-activating mutations. These mutations are associated with increased activity of survival pathways including PI3K/AKT and STAT3/5. We report that EGFR-activating mutations also surprisingly lead to decreased ability to activate ERK compared to wild-type EGFR. In NSCLC cells and mouse embryonic fi...

  5. MET signaling in keratinocytes activates EGFR and initiates squamous carcinogenesis.

    Science.gov (United States)

    Cataisson, Christophe; Michalowski, Aleksandra M; Shibuya, Kelly; Ryscavage, Andrew; Klosterman, Mary; Wright, Lisa; Dubois, Wendy; Liu, Fan; Zhuang, Anne; Rodrigues, Kameron B; Hoover, Shelley; Dwyer, Jennifer; Simpson, Mark R; Merlino, Glenn; Yuspa, Stuart H

    2016-06-21

    The receptor tyrosine kinase MET is abundant in many human squamous cell carcinomas (SCCs), but its functional significance in tumorigenesis is not clear. We found that the incidence of carcinogen-induced skin squamous tumors was substantially increased in transgenic MT-HGF (mouse metallothionein-hepatocyte growth factor) mice, which have increased abundance of the MET ligand HGF. Squamous tumors also erupted spontaneously on the skin of MT-HGF mice that were promoted by wounding or the application of 12-O-tetradecanoylphorbol 13-acetate, an activator of protein kinase C. Carcinogen-initiated tumors had Ras mutations, but spontaneous tumors did not. Cultured keratinocytes from MT-HGF mice and oncogenic RAS-transduced keratinocytes shared phenotypic and biochemical features of initiation that were dependent on autocrine activation of epidermal growth factor receptor (EGFR) through increased synthesis and release of EGFR ligands, which was mediated by the kinase SRC, the pseudoproteases iRhom1 and iRhom2, and the metallopeptidase ADAM17. Pharmacological inhibition of EGFR caused the regression of MT-HGF squamous tumors that developed spontaneously in orthografts of MT-HGF keratinocytes combined with dermal fibroblasts and implanted onto syngeneic mice. The global gene expression profile in MET-transformed keratinocytes was highly concordant with that in RAS-transformed keratinocytes, and a core RAS/MET coexpression network was activated in precancerous and cancerous human skin lesions. Tissue arrays revealed that many human skin SCCs have abundant HGF at both the transcript and protein levels. Thus, through the activation of EGFR, MET activation parallels a RAS pathway to contribute to human and mouse cutaneous cancers. Copyright © 2016, American Association for the Advancement of Science.

  6. Co-activation of STAT3 and YES-Associated Protein 1 (YAP1) Pathway in EGFR-Mutant NSCLC.

    Science.gov (United States)

    Chaib, Imane; Karachaliou, Niki; Pilotto, Sara; Codony Servat, Jordi; Cai, Xueting; Li, Xuefei; Drozdowskyj, Ana; Servat, Carles Codony; Yang, Jie; Hu, Chunping; Cardona, Andres Felipe; Vivanco, Guillermo Lopez; Vergnenegre, Alain; Sanchez, Jose Miguel; Provencio, Mariano; de Marinis, Filipo; Passaro, Antonio; Carcereny, Enric; Reguart, Noemi; Campelo, Charo Garcia; Teixido, Christina; Sperduti, Isabella; Rodriguez, Sonia; Lazzari, Chiara; Verlicchi, Alberto; de Aguirre, Itziar; Queralt, Cristina; Wei, Jia; Estrada, Roger; Puig de la Bellacasa, Raimon; Ramirez, Jose Luis; Jacobson, Kirstine; Ditzel, Henrik J; Santarpia, Mariacarmela; Viteri, Santiago; Molina, Migual Angel; Zhou, Caicun; Cao, Peng; Ma, Patrick C; Bivona, Trever G; Rosell, Rafael

    2017-09-01

    The efficacy of epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) in EGFR-mutant non-small cell lung cancer (NSCLC) is limited by adaptive activation of cell survival signals. We hypothesized that both signal transducer and activator of transcription 3 (STAT3) and Src-YES-associated protein 1 (YAP1) signaling are dually activated during EGFR TKI treatment to limit therapeutic response. We used MTT and clonogenic assays, immunoblotting, and quantitative polymerase chain reaction to evaluate the efficacy of EGFR TKI alone and in combination with STAT3 and Src inhibition in three EGFR-mutant NSCLC cell lines. The Chou-Talalay method was used for the quantitative determination of drug interaction. We examined tumor growth inhibition in one EGFR-mutant NSCLC xenograft model (n = 4 mice per group). STAT3 and YAP1 expression was evaluated in tumors from 119 EGFR-mutant NSCLC patients (64 in an initial cohort and 55 in a validation cohort) by quantitative polymerase chain reaction. Kaplan-Meier and Cox regression analyses were used to assess the correlation between survival and gene expression. All statistical tests were two-sided. We discovered that lung cancer cells survive initial EGFR inhibitor treatment through activation of not only STAT3 but also Src-YAP1 signaling. Cotargeting EGFR, STAT3, and Src was synergistic in two EGFR-mutant NSCLC cell lines with a combination index of 0.59 (95% confidence interval [CI] = 0.54 to 0.63) for the PC-9 and 0.59 (95% CI = 0.54 to 0.63) for the H1975 cell line. High expression of STAT3 or YAP1 predicted worse progression-free survival (hazard ratio [HR] = 3.02, 95% CI = 1.54 to 5.93, P = .001, and HR = 2.57, 95% CI = 1.30 to 5.09, P = .007, respectively) in an initial cohort of 64 EGFR-mutant NSCLC patients treated with firstline EGFR TKIs. Similar results were observed in a validation cohort. Our study uncovers a coordinated signaling network centered on both STAT3 and Src-YAP signaling

  7. Determination of EGFR endocytosis kinetic by auto-regulatory association of PLD1 with mu2.

    Science.gov (United States)

    Lee, Jun Sung; Kim, Il Shin; Kim, Jung Hwan; Cho, Wonhwa; Suh, Pann-Ghill; Ryu, Sung Ho

    2009-09-18

    Upon ligand binding, cell surface signaling receptors are internalized through a process tightly regulated by endocytic proteins and adaptor protein 2 (AP2) to orchestrate them. Although the molecular identities and roles of endocytic proteins are becoming clearer, it is still unclear what determines the receptor endocytosis kinetics which is mainly regulated by the accumulation of endocytic apparatus to the activated receptors. Here we employed the kinetic analysis of endocytosis and adaptor recruitment to show that mu2, a subunit of AP2 interacts directly with phospholipase D (PLD)1, a receptor-associated signaling protein and this facilitates the membrane recruitment of AP2 and the endocytosis of epidermal growth factor receptor (EGFR). We also demonstrate that the PLD1-mu2 interaction requires the binding of PLD1 with phosphatidic acid, its own product. These results suggest that the temporal regulation of EGFR endocytosis is achieved by auto-regulatory PLD1 which senses the receptor activation and triggers the translocation of AP2 near to the activated receptor.

  8. Determination of EGFR endocytosis kinetic by auto-regulatory association of PLD1 with mu2.

    Directory of Open Access Journals (Sweden)

    Jun Sung Lee

    2009-09-01

    Full Text Available Upon ligand binding, cell surface signaling receptors are internalized through a process tightly regulated by endocytic proteins and adaptor protein 2 (AP2 to orchestrate them. Although the molecular identities and roles of endocytic proteins are becoming clearer, it is still unclear what determines the receptor endocytosis kinetics which is mainly regulated by the accumulation of endocytic apparatus to the activated receptors.Here we employed the kinetic analysis of endocytosis and adaptor recruitment to show that mu2, a subunit of AP2 interacts directly with phospholipase D (PLD1, a receptor-associated signaling protein and this facilitates the membrane recruitment of AP2 and the endocytosis of epidermal growth factor receptor (EGFR. We also demonstrate that the PLD1-mu2 interaction requires the binding of PLD1 with phosphatidic acid, its own product.These results suggest that the temporal regulation of EGFR endocytosis is achieved by auto-regulatory PLD1 which senses the receptor activation and triggers the translocation of AP2 near to the activated receptor.

  9. Hypoxia activated EGFR signaling induces epithelial to mesenchymal transition (EMT.

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    Ashish Misra

    Full Text Available Metastasis is a multi-step process which requires the conversion of polarized epithelial cells to mesenchymal cells, Epithelial-Mesenchymal Transition (EMT. EMT is essential during embryonic morphogenesis and has been implicated in the progression of primary tumors towards metastasis. Hypoxia is known to induce EMT; however the molecular mechanism is still poorly understood. Using the A431 epithelial cancer cell line, we show that cells grown under hypoxic conditions migrated faster than cells grown under normal oxygen environment. Cells grown under hypoxia showed reduced adhesion to the extracellular matrix (ECM probably due to reduced number of Vinculin patches. Growth under hypoxic conditions also led to down regulation of E-cadherin and up regulation of vimentin expression. The increased motility of cells grown under hypoxia could be due to redistribution of Rac1 to the plasma membrane as opposed to increased expression of Rac1. EGF (Epidermal Growth Factor is a known inducer of EMT and growth of A431 cells in the absence of oxygen led to increased expression of EGFR (EGF Receptor. Treatment of A431 cells with EGF led to reduced cell adhesion to ECM, increased cell motility and other EMT characteristics. Furthermore, this transition was blocked by the monoclonal antibody Cetuximab. Cetuximab also blocked the hypoxia-induced EMT suggesting that cell growth under hypoxic conditions led to activation of EGFR signaling and induction of EMT phenotype.

  10. IMPAIRED SHP2-MEDIATED ERK ACTIVATION CONTRIBUTES TO GEFITINIB SENSITIVITY OF LUNG CANCER CELLS WITH EGFR-ACTIVATING MUTATIONS

    Science.gov (United States)

    Lazzara, Matthew J.; Lane, Keara; Chan, Richard; Jasper, Paul J.; Yaffe, Michael B.; Sorger, Peter K.; Jacks, Tyler; Neel, Benjamin G.; Lauffenburger, Douglas A.

    2010-01-01

    Most non-small cell lung cancers (NSCLC) display elevated expression of epidermal growth factor receptor (EGFR), but response to EGFR kinase inhibitors is predominantly limited to NSCLC harboring EGFR-activating mutations. These mutations are associated with increased activity of survival pathways including PI3K/AKT and STAT3/5. We report that EGFR-activating mutations also surprisingly lead to decreased ability to activate ERK compared to wild-type EGFR. In NSCLC cells and mouse embryonic fibroblasts expressing mutant EGFR, this effect on ERK correlates with decreased EGFR internalization and reduced phosphorylation of SHP2, a tyrosine phosphatase required for the full activation of ERK. We further demonstrate that ERK activation levels impact cellular response to gefitinib. NSCLC cells with EGFR mutation display reduced gefitinib sensitivity when ERK activation is augmented by expression of constitutively active mutants of MEK. Conversely, in an NSCLC cell line expressing wild-type EGFR, gefitinib treatment along with or following MEK inhibition increases death response compared to treatment with gefitinib alone. Our results demonstrate that EGFR-activating mutations may promote some survival pathways but simultaneously impair others. This multivariate alteration of the network governing cellular response to gefitinib, which we term “oncogene imbalance”, portends a potentially broader ability to treat gefitinib-resistant NSCLC. PMID:20406974

  11. Detecting intratumoral heterogeneity of EGFR activity by liposome-based in vivo transfection of a fluorescent biosensor.

    Science.gov (United States)

    Weitsman, G; Mitchell, N J; Evans, R; Cheung, A; Kalber, T L; Bofinger, R; Fruhwirth, G O; Keppler, M; Wright, Z V F; Barber, P R; Gordon, P; de Koning, T; Wulaningsih, W; Sander, K; Vojnovic, B; Ameer-Beg, S; Lythgoe, M; Arnold, J N; Årstad, E; Festy, F; Hailes, H C; Tabor, A B; Ng, T

    2017-06-22

    Despite decades of research in the epidermal growth factor receptor (EGFR) signalling field, and many targeted anti-cancer drugs that have been tested clinically, the success rate for these agents in the clinic is low, particularly in terms of the improvement of overall survival. Intratumoral heterogeneity is proposed as a major mechanism underlying treatment failure of these molecule-targeted agents. Here we highlight the application of fluorescence lifetime microscopy (FLIM)-based biosensing to demonstrate intratumoral heterogeneity of EGFR activity. For sensing EGFR activity in cells, we used a genetically encoded CrkII-based biosensor which undergoes conformational changes upon tyrosine-221 phosphorylation by EGFR. We transfected this biosensor into EGFR-positive tumour cells using targeted lipopolyplexes bearing EGFR-binding peptides at their surfaces. In a murine model of basal-like breast cancer, we demonstrated a significant degree of intratumoral heterogeneity in EGFR activity, as well as the pharmacodynamic effect of a radionuclide-labeled EGFR inhibitor in situ. Furthermore, a significant correlation between high EGFR activity in tumour cells and macrophage-tumour cell proximity was found to in part account for the intratumoral heterogeneity in EGFR activity observed. The same effect of macrophage infiltrate on EGFR activation was also seen in a colorectal cancer xenograft. In contrast, a non-small cell lung cancer xenograft expressing a constitutively active EGFR conformational mutant exhibited macrophage proximity-independent EGFR activity. Our study validates the use of this methodology to monitor therapeutic response in terms of EGFR activity. In addition, we found iNOS gene induction in macrophages that are cultured in tumour cell-conditioned media as well as an iNOS activity-dependent increase in EGFR activity in tumour cells. These findings point towards an immune microenvironment-mediated regulation that gives rise to the observed intratumoral

  12. EGFR and HER2 activate rigidity sensing only on rigid matrices

    Science.gov (United States)

    Saxena, Mayur; Liu, Shuaimin; Yang, Bo; Hajal, Cynthia; Changede, Rishita; Hu, Junqiang; Wolfenson, Haguy; Hone, James; Sheetz, Michael P.

    2017-07-01

    Epidermal growth factor receptor (EGFR) interacts with integrins during cell spreading and motility, but little is known about the role of EGFR in these mechanosensing processes. Here we show, using two different cell lines, that in serum- and EGF-free conditions, EGFR or HER2 activity increase spreading and rigidity-sensing contractions on rigid, but not soft, substrates. Contractions peak after 15-20 min, but diminish by tenfold after 4 h. Addition of EGF at that point increases spreading and contractions, but this can be blocked by myosin-II inhibition. We further show that EGFR and HER2 are activated through phosphorylation by Src family kinases (SFK). On soft surfaces, neither EGFR inhibition nor EGF stimulation have any effect on cell motility. Thus, EGFR or HER2 can catalyse rigidity sensing after associating with nascent adhesions under rigidity-dependent tension downstream of SFK activity. This has broad implications for the roles of EGFR and HER2 in the absence of EGF both for normal and cancerous growth.

  13. DDX3X induces primary EGFR-TKI resistance based on intratumor heterogeneity in lung cancer cells harboring EGFR-activating mutations.

    Directory of Open Access Journals (Sweden)

    Koichiro Nozaki

    Full Text Available The specific mechanisms how lung cancer cells harboring epidermal growth factor receptor (EGFR activating mutations can survive treatment with EGFR-tyrosine kinase inhibitors (TKIs until they eventually acquire treatment-resistance genetic mutations are unclear. The phenotypic diversity of cancer cells caused by genetic or epigenetic alterations (intratumor heterogeneity confers treatment failure and may foster tumor evolution through Darwinian selection. Recently, we found DDX3X as the protein that was preferentially expressed in murine melanoma with cancer stem cell (CSC-like phenotypes by proteome analysis. In this study, we transfected PC9, human lung cancer cells harboring EGFR exon19 deletion, with cDNA encoding DDX3X and found that DDX3X, an ATP-dependent RNA helicase, induced CSC-like phenotypes and the epithelial-mesenchymal transition (EMT accompanied with loss of sensitivity to EGFR-TKI. DDX3X expression was associated with upregulation of Sox2 and increase of cancer cells exhibiting CSC-like phenotypes, such as anchorage-independent proliferation, strong expression of CD44, and aldehyde dehydrogenase (ALDH. The EMT with switching from E-cadherin to N-cadherin was also facilitated by DDX3X. Either ligand-independent or ligand-induced EGFR phosphorylation was inhibited in lung cancer cells that strongly expressed DDX3X. Lack of EGFR signal addiction resulted in resistance to EGFR-TKI. Moreover, we found a small nonadherent subpopulation that strongly expressed DDX3X accompanied by the same stem cell-like properties and the EMT in parental PC9 cells. The unique subpopulation lacked EGFR signaling and was highly resistant to EGFR-TKI. In conclusion, our data indicate that DDX3X may play a critical role for inducing phenotypic diversity, and that treatment targeting DDX3X may overcome primary resistance to EGFR-TKI resulting from intratumor heterogeneity.

  14. Toxoplasma gondii-induced activation of EGFR prevents autophagy protein-mediated killing of the parasite.

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    Luis Muniz-Feliciano

    Full Text Available Toxoplasma gondii resides in an intracellular compartment (parasitophorous vacuole that excludes transmembrane molecules required for endosome-lysosome recruitment. Thus, the parasite survives by avoiding lysosomal degradation. However, autophagy can re-route the parasitophorous vacuole to the lysosomes and cause parasite killing. This raises the possibility that T. gondii may deploy a strategy to prevent autophagic targeting to maintain the non-fusogenic nature of the vacuole. We report that T. gondii activated EGFR in endothelial cells, retinal pigment epithelial cells and microglia. Blockade of EGFR or its downstream molecule, Akt, caused targeting of the parasite by LC3(+ structures, vacuole-lysosomal fusion, lysosomal degradation and killing of the parasite that were dependent on the autophagy proteins Atg7 and Beclin 1. Disassembly of GPCR or inhibition of metalloproteinases did not prevent EGFR-Akt activation. T. gondii micronemal proteins (MICs containing EGF domains (EGF-MICs; MIC3 and MIC6 appeared to promote EGFR activation. Parasites defective in EGF-MICs (MIC1 ko, deficient in MIC1 and secretion of MIC6; MIC3 ko, deficient in MIC3; and MIC1-3 ko, deficient in MIC1, MIC3 and secretion of MIC6 caused impaired EGFR-Akt activation and recombinant EGF-MICs (MIC3 and MIC6 caused EGFR-Akt activation. In cells treated with autophagy stimulators (CD154, rapamycin EGFR signaling inhibited LC3 accumulation around the parasite. Moreover, increased LC3 accumulation and parasite killing were noted in CD154-activated cells infected with MIC1-3 ko parasites. Finally, recombinant MIC3 and MIC6 inhibited parasite killing triggered by CD154 particularly against MIC1-3 ko parasites. Thus, our findings identified EGFR activation as a strategy used by T. gondii to maintain the non-fusogenic nature of the parasitophorous vacuole and suggest that EGF-MICs have a novel role in affecting signaling in host cells to promote parasite survival.

  15. Unraveling the pivotal role of ALIX in MVB sorting and silencing of activated EGFR

    Science.gov (United States)

    Sun, Sheng; Zhou, Xi; Zhang, Wei; Gallick, Gary E.; Kuang, Jian

    2015-01-01

    ESCRT-III mediated membrane invagination and scission is a critical step in MVB sorting of ubiquitinated membrane receptors and generally thought to be required for degradation of these receptors in lysosomes. The adaptor protein ALIX is critically involved in multiple ESCRT-III-mediated membrane remodeling processes in mammalian cells. However, ALIX knockdown does not inhibit degradation of activated EGFR in mammalian cell lines, leading to a widely held notion that ALIX is not critically involved in MVB sorting of ubiquitinated membrane receptors in mammalian cells. In this study, we demonstrate that despite its non-essential roles in degradation of activated EGFR, ALIX plays a critical role in MVB sorting and silencing of activated EGFR. EGF stimulation of mammalian cell lines induces ALIX interaction with ubiquitinated EGFR through the ALIX V domain and increases ALIX association with membrane-bound CHMP4 through the ALIX Bro1 domain. Under both continuous and pulse-chase EGF stimulation conditions, inhibition of ALIX interaction with membrane-bound CHMP4, inhibition of ALIX dimerization through the V domain or ALIX knockdown dramatically inhibits MVB sorting of activated EGFR and promotes sustained activation of ERK1/2. Under the continuous EGF stimulation conditions, these cell treatments also retard degradation of activated EGFR. These findings indicate that ALIX is critically involved in MVB sorting of ubiquitinated membrane receptors in mammalian cells. PMID:25510652

  16. Co-activation of STAT3 and YES-Associated Protein 1 (YAP1) Pathway in EGFR-Mutant NSCLC

    DEFF Research Database (Denmark)

    Chaib, Imane; Karachaliou, Niki; Pilotto, Sara

    2017-01-01

    Background: The efficacy of epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) in EGFR-mutant non-small cell lung cancer (NSCLC) is limited by adaptive activation of cell survival signals. We hypothesized that both signal transducer and activator of transcription 3 (STAT3......) and Src-YES-associated protein 1 (YAP1) signaling are dually activated during EGFR TKI treatment to limit therapeutic response. Methods: We used MTT and clonogenic assays, immunoblotting, and quantitative polymerase chain reaction to evaluate the efficacy of EGFR TKI alone and in combination with STAT3...... that lung cancer cells survive initial EGFR inhibitor treatment through activation of not only STAT3 but also Src-YAP1 signaling. Cotargeting EGFR, STAT3, and Src was synergistic in two EGFR-mutant NSCLC cell lines with a combination index of 0.59 (95% confidence interval [CI] = 0.54 to 0.63) for the PC-9...

  17. Nimotuzumab Induces NK Cell Activation, Cytotoxicity, Dendritic Cell Maturation and Expansion of EGFR-Specific T Cells in Head and Neck Cancer Patients

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    Zaima Mazorra

    2017-06-01

    Full Text Available Survival benefit and long-term duration of clinical response have been seen using the epidermal growth factor receptor (EGFR-targeted monoclonal antibody (mAb nimotuzumab. Blocking EGFR signaling may not be the only mechanism of action underlying its efficacy. As an IgG1 isotype mAb, nimotuzumab’s capacity of killing tumor cells by antibody dependent cellular cytotoxicity (ADCC and to induce an immune response in cancer patients have not been studied. ADCC-induced by nimotuzumab was determined using a 51Cr release assay. The in vitro effect of nimotuzumab on natural killer (NK cell activation and dendritic cell (DC maturation and the in vivo frequency of circulating regulatory T cells (Tregs and NK cells were assessed by flow cytometry. Cytokine levels in supernatants were determined by ELISA. ELISpot was carried out to quantify EGFR-specific T cells in nimotuzumab-treated head and neck cancer (HNSCC patients. Nimotuzumab was able to kill EGFR+ tumor cells by NK cell-mediated ADCC. Nimotuzumab-activated NK cells promoted DC maturation and EGFR-specific CD8+ T cell priming. Interestingly, nimotuzumab led to upregulation of some immune checkpoint molecules on NK cells (TIM-3 and DC (PD-L1, to a lower extent than another EGFR mAb, cetuximab. Furthermore, circulating EGFR-specific T cells were identified in nimotuzumab-treated HNSCC patients. Notably, nimotuzumab combined with cisplatin-based chemotherapy and radiation increased the frequency of peripheral CD4+CD39+FOXP3+Tregs which otherwise were decreased to baseline values when nimotuzumab was used as monotherapy. The frequency of circulating NK cells remained constant during treatment. Nimotuzumab-induced, NK cell-mediated DC priming led to induction of anti-EGFR specific T cells in HNSCC patients. The association between EGFR-specific T cells and patient clinical benefit with nimotuzumab treatment should be investigated.

  18. Identification of the zinc finger 216 (ZNF216) in human carcinoma cells: a potential regulator of EGFR activity.

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    Mincione, Gabriella; Di Marcantonio, Maria Carmela; Tarantelli, Chiara; Savino, Luca; Ponti, Donatella; Marchisio, Marco; Lanuti, Paola; Sancilio, Silvia; Calogero, Antonella; Di Pietro, Roberta; Muraro, Raffaella

    2016-11-15

    Epidermal Growth Factor Receptor (EGFR), a member of the ErbB family of receptor tyrosine kinase (RTK) proteins, is aberrantly expressed or deregulated in tumors and plays pivotal roles in cancer onset and metastatic progression. ZNF216 gene has been identified as one of Immediate Early Genes (IEGs) induced by RTKs. Overexpression of ZNF216 protein sensitizes 293 cell line to TNF-α induced apoptosis. However, ZNF216 overexpression has been reported in medulloblastomas and metastatic nasopharyngeal carcinomas. Thus, the role of this protein is still not clearly understood. In this study, the inverse correlation between EGFR and ZNF216 expression was confirmed in various human cancer cell lines differently expressing EGFR. EGF treatment of NIH3T3 cells overexpressing both EGFR and ZNF216 (NIH3T3-EGFR/ZNF216), induced a long lasting activation of EGFR in the cytosolic fraction and an accumulation of phosphorylated EGFR (pEGFR) more in the nuclear than in the cytosolic fraction compared to NIH3T3-EGFR cells. Moreover, EGF was able to stimulate an increased expression of ZNF216 in the cytosolic compartment and its nuclear translocation in a time-dependent manner in NIH3T3-EGFR/ZNF216. A similar trend was observed in A431 cells endogenously expressing the EGFR and transfected with Znf216. The increased levels of pEGFR and ZNF216 in the nuclear fraction of NIH3T3-EGFR/ZNF216 cells were paralleled by increased levels of phospho-MAPK and phospho-Akt. Surprisingly, EGF treatment of NIH3T3-EGFR/ZNF216 cells induced a significant increase of apoptosis thus indicating that ZNF216 could sensitize cells to EGF-induced apoptosis and suggesting that it may be involved in the regulation and effects of EGFR signaling.

  19. Regulation of HGF Expression by ΔEGFR-Mediated c-Met Activation in Glioblastoma Cells

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    Jeannine Garnett

    2013-01-01

    Full Text Available The hepatocyte growth factor receptor (c-Met and a constitutively active mutant of the epidermal growth factor receptor (ΔEGFR/EGFRvIII are frequently overexpressed in glioblastoma (GBM and promote tumorigenesis. The mechanisms underlying elevated hepatocyte growth factor (HGF production in GBM are not understood. We found higher, coordinated mRNA expression levels of HGF and c-Met in mesenchymal (Mes GBMs, a subtype associated with poor treatment response and shorter overall survival. In an HGF/c-Met–dependent GBM cell line, HGF expression declined upon silencing of c-Met using RNAi or by inhibiting its activity with SU11274. Silencing c-Met decreased anchorage-independent colony formation and increased the survival of mice bearing intracranial GBM xenografts. Consistent with these findings, c-Met activation by ΔEGFR also elevated HGF expression, and the inhibition of ΔEGFR with AG1478 reduced HGF levels. Interestingly, c-Met expression was required for ΔEGFR-mediated HGF production, anchorage-independent growth, and in vivo tumorigenicity, suggesting that these pathways are coupled. Using an unbiased mass spectrometry–based screen, we show that signal transducer and activator of transcription 3 (STAT3 Y705 is a downstream target of c-Met signaling. Suppression of STAT3 phosphorylation with WP1193 reduced HGF expression in ΔEGFR-expressing GBM cells, whereas constitutively active STAT3 partially rescued HGF expression and colony formation in c-Met knockdown cells expressing ΔEGFR. These results suggest that the c-Met/HGF signaling axis is enhanced by ΔEGFR through increased STAT3-dependent HGF expression and that targeting c-Met in Mes GBMs may be an important strategy for therapy.

  20. 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...

  1. 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

    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...

  2. Activation of a Neospora caninum EGFR-Like Kinase Facilitates Intracellular Parasite Proliferation

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    Xiaoxia Jin

    2017-10-01

    Full Text Available The Apicomplexan parasite Neospora caninum, an obligate intracellular protozoan, causes serious diseases in a number of mammalian species, especially in cattle. Infection with N. caninum is associated with abortions in both dairy and beef cattle worldwide which have a major economic impact on the cattle industry. However, the mechanism by which N. caninum proliferates within host cells is poorly understood. Epidermal growth factor receptor (EGFR is a protein kinase ubiquitously expressed, present on cell surfaces in numerous species, which has been confirmed to be essential in signal transduction involved in cell growth, proliferation, survival, and many other intracellular processes. However, the presence of EGFR in N. caninum and its role in N. caninum proliferation remain unclear. In the present study, we identified a putative EGFR-like kinase in N. caninum, which could be activated in tachyzoites by infection or treatment with rNcMIC3 [containing four epidermal growth factor (EGF domains] or human EGF. Blockade of EGFR-like in tachyzoites by AG1478 significantly reduced parasite proliferation in host cells. Our data suggested that the activation of tachyzoite EGFR-like might facilitate the intracellular proliferation of N. caninum.

  3. Proteomic profiling of patient-derived glioblastoma xenografts identifies a subset with activated EGFR: Implications for drug development

    Science.gov (United States)

    Brown, Kristine E.; Chagoya, Gustavo; Kwatra, Shawn G.; Yen, Timothy; Keir, Stephen T.; Cooter, Mary; Hoadley, Katherine A.; Rasheed, Ahmed; Lipp, Eric S.; Mclendon, Roger; Ali-Osman, Francis; Bigner, Darell D.; Sampson, John H.; Kwatra, Madan M.

    2015-01-01

    The development of drugs to inhibit glioblastoma (GBM) growth requires reliable preclinical models. To date, proteomic level validation of widely used patient-derived glioblastoma xenografts (PDGX) has not been performed. In the present study, we characterized 20 PDGX models according to subtype classification based on The Cancer Genome Atlas (TCGA) criteria, TP53, PTEN, IDH 1/2 and TERT promoter genetic analysis, EGFR amplification status, and examined their proteomic profiles against those of their parent tumors. The 20 PDGXs belonged to three of four TCGA subtypes: 8 classical, 8 mesenchymal, and 4 proneural; none neural. Amplification of EGFR gene was observed in 9 out of 20 xenografts, and of these, 3 harbored the EGFRvIII mutation. We then performed proteomic profiling of PDGX, analyzing expression/activity of several proteins including EGFR. Levels of EGFR phosphorylated at Y1068 vary considerably between PDGX samples, and this pattern was also seen in primary GBM. Partitioning of 20 PDGX into high (n=5) and low (n=15) groups identified a panel of proteins associated with high EGFR activity. Thus, PDGX with high EGFR activity represent an excellent preclinical model to develop therapies for a subset of GBM patients whose tumors are characterized by high EGFR activity. Further, the proteins found to be associated with high EGFR activity can be monitored to assess the effectiveness of targeting EGFR. PMID:25598002

  4. Curcumin Induces EGFR Degradation in Lung Adenocarcinoma and Modulates p38 Activation in Intestine: The Versatile Adjuvant for Gefitinib Therapy

    Science.gov (United States)

    Lee, Jen-Yi; Lee, Yee-Ming; Chang, Gee-Chen; Yu, Sung-Liang; Hsieh, Wan-Yu; Chen, Jeremy J. W.; Chen, Huei-Wen; Yang, Pan-Chyr

    2011-01-01

    Background Non-small cell lung cancer (NSCLC) patients with L858R or exon 19 deletion mutations in epidermal growth factor receptor (EGFR) have good responses to the tyrosine kinase inhibitor (TKI), gefitinib. However, patients with wild-type EGFR and acquired mutation in EGFR T790M are resistant to gefitinib treatment. Here, we showed that curcumin can improve the efficiency of gefitinib in the resistant NSCLC cells both in vitro and in vivo models. Methods/Principal Findings After screening 598 herbal and natural compounds, we found curcumin could inhibit cell proliferation in different gefitinib-resistant NSCLC cell lines; concentration-dependently down-regulate EGFR phosphorylation through promoting EGFR degradation in NSCLC cell lines with wild-type EGFR or T790M EGFR. In addition, the anti-tumor activity of gefitinib was potentiated via curcumin through blocking EGFR activation and inducing apoptosis in gefitinib-resistant NSCLC cell lines; also the combined treatment with curcumin and gefitinib exhibited significant inhibition in the CL1-5, A549 and H1975 xenografts tumor growth in SCID mice through reducing EGFR, c-MET, cyclin D1 expression, and inducing apoptosis activation through caspases-8, 9 and PARP. Interestingly, we observed that the combined treatment group represented better survival rate and less intestinal mucosal damage compare to gefitinib-alone therapy. We showed that curcumin attenuated the gefitinib-induced cell proliferation inhibition and apoptosis through altering p38 mitogen-activated protein kinase (MAPK) activation in intestinal epithelia cell. Conclusions/Significance Curcumin potentiates antitumor activity of gefitinib in cell lines and xenograft mice model of NSCLC through inhibition of proliferation, EGFR phosphorylation, and induction EGFR ubiquitination and apoptosis. In addition, curcumin attenuates gefitinib-induced gastrointestinal adverse effects via altering p38 activation. These findings provide a novel treatment strategy

  5. Curcumin induces EGFR degradation in lung adenocarcinoma and modulates p38 activation in intestine: the versatile adjuvant for gefitinib therapy.

    Directory of Open Access Journals (Sweden)

    Jen-Yi Lee

    Full Text Available BACKGROUND: Non-small cell lung cancer (NSCLC patients with L858R or exon 19 deletion mutations in epidermal growth factor receptor (EGFR have good responses to the tyrosine kinase inhibitor (TKI, gefitinib. However, patients with wild-type EGFR and acquired mutation in EGFR T790M are resistant to gefitinib treatment. Here, we showed that curcumin can improve the efficiency of gefitinib in the resistant NSCLC cells both in vitro and in vivo models. METHODS/PRINCIPAL FINDINGS: After screening 598 herbal and natural compounds, we found curcumin could inhibit cell proliferation in different gefitinib-resistant NSCLC cell lines; concentration-dependently down-regulate EGFR phosphorylation through promoting EGFR degradation in NSCLC cell lines with wild-type EGFR or T790M EGFR. In addition, the anti-tumor activity of gefitinib was potentiated via curcumin through blocking EGFR activation and inducing apoptosis in gefitinib-resistant NSCLC cell lines; also the combined treatment with curcumin and gefitinib exhibited significant inhibition in the CL1-5, A549 and H1975 xenografts tumor growth in SCID mice through reducing EGFR, c-MET, cyclin D1 expression, and inducing apoptosis activation through caspases-8, 9 and PARP. Interestingly, we observed that the combined treatment group represented better survival rate and less intestinal mucosal damage compare to gefitinib-alone therapy. We showed that curcumin attenuated the gefitinib-induced cell proliferation inhibition and apoptosis through altering p38 mitogen-activated protein kinase (MAPK activation in intestinal epithelia cell. CONCLUSIONS/SIGNIFICANCE: Curcumin potentiates antitumor activity of gefitinib in cell lines and xenograft mice model of NSCLC through inhibition of proliferation, EGFR phosphorylation, and induction EGFR ubiquitination and apoptosis. In addition, curcumin attenuates gefitinib-induced gastrointestinal adverse effects via altering p38 activation. These findings provide a novel

  6. Bisphenol A activates EGFR and ERK promoting proliferation, tumor spheroid formation and resistance to EGFR pathway inhibition in estrogen receptor-negative inflammatory breast cancer cells.

    Science.gov (United States)

    Sauer, Scott J; Tarpley, Michael; Shah, Imran; Save, Akshay V; Lyerly, H Kim; Patierno, Steven R; Williams, Kevin P; Devi, Gayathri R

    2017-03-01

    Emerging evidence from epidemiological studies suggests a link between environmental chemical exposure and progression of aggressive breast cancer subtypes. Of all clinically distinct types of breast cancers, the most lethal phenotypic variant is inflammatory breast cancer (IBC). Overexpression of epidermal growth factor receptors (EGFR/HER2) along with estrogen receptor (ER) negativity is common in IBC tumor cells, which instead of a solid mass present as rapidly proliferating diffuse tumor cell clusters. Our previous studies have demonstrated a role of an adaptive response of increased antioxidants in acquired resistance to EGFR-targeting drugs in IBC. Environmental chemicals are known to induce oxidative stress resulting in perturbations in signal transduction pathways. It is therefore of interest to identify chemicals that can potentiate EGFR mitogenic effects in IBC. Herein, we assessed in ER-negative IBC cells a subset of chemicals from the EPA ToxCast set for their effect on EGFR activation and in multiple cancer phenotypic assays. We demonstrated that endocrine-disrupting chemicals such as bisphenol A (BPA) and 2,2-bis(p-hydroxyphenyl)-1,1,1-trichloroethane can increase EGFR/ERK signaling. BPA also caused a corresponding increase in expression of SOD1 and anti-apoptotic Bcl-2, key markers of antioxidant and anti-apoptotic processes. BPA potentiated clonogenic growth and tumor spheroid formation in vitro, reflecting IBC-specific pathological characteristics. Furthermore, we identified that BPA was able to attenuate the inhibitory effect of an EGFR targeted drug in a longer-term anchorage-independent growth assay. These findings provide a potential mechanistic basis for environmental chemicals such as BPA in potentiating a hyperproliferative and death-resistant phenotype in cancer cells by activating mitogenic pathways to which the tumor cells are addicted for survival. © The Author 2017. Published by Oxford University Press. All rights reserved. For

  7. Activation of the epidermal growth factor receptor (EGFR) by a novel metalloprotease pathway.

    LENUS (Irish Health Repository)

    Bergin, David A

    2008-11-14

    Neutrophil Elastase (NE) is a pro-inflammatory protease present at higher than normal levels in the lung during inflammatory disease. NE regulates IL-8 production from airway epithelial cells and can activate both EGFR and TLR4. TACE\\/ADAM17 has been reported to trans-activate EGFR in response to NE. Here, using 16HBE14o-human bronchial epithelial cells we demonstrate a new mechanism by which NE regulates both of these events. A high molecular weight soluble metalloprotease activity detectable only in supernatants from NE-treated cells by gelatin and casein zymography was confirmed to be meprin alpha by Western immunoblotting. In vitro studies demonstrated the ability of NE to activate meprin alpha, which in turn could release soluble TGFalpha and induce IL-8 production from 16HBE14o- cells. These effects were abrogated by actinonin, a specific meprin inhibitor. NE-induced IL-8 expression was also inhibited by meprin alpha siRNA. Immunoprecipitation studies detected EGFR\\/TLR4 complexes in NE-stimulated cells overexpressing these receptors. Confocal studies confirmed colocalization of EGFR and TLR4 in 16HBE14o- cells stimulated with meprin alpha. NFkappaB was also activated via MyD88 in these cells by meprin alpha. In bronchoalveolar lavage fluid from NE knock-out mice infected intra-tracheally with Pseudomonas aeruginosa meprin alpha was significantly decreased compared with control mice, and was significantly increased and correlated with NE activity, in bronchoalveolar lavage fluid from individuals with cystic fibrosis but not healthy controls. The data describe a previously unidentified lung metalloprotease meprin alpha, and its role in NE-induced EGFR and TLR4 activation and IL-8 production.

  8. Effects of activated fibroblasts on phenotype modulation, EGFR signalling and cell cycle regulation in OSCC cells

    Energy Technology Data Exchange (ETDEWEB)

    Berndt, Alexander, E-mail: alexander.berndt@med.uni-jena.de [Center for Molecular Biomedicine, Institute of Pathology, Jena University Hospital, 07740 Jena (Germany); Büttner, Robert, E-mail: Robert-Buettner@gmx.net [Institute of Biochemistry and Biophysics, Friedrich Schiller University Jena, 07740 Jena (Germany); Gühne, Stefanie, E-mail: stefanie_guehne@gmx.net [Center for Molecular Biomedicine, Institute of Pathology, Jena University Hospital, 07740 Jena (Germany); Gleinig, Anna, E-mail: annagleinig@yahoo.com [Center for Molecular Biomedicine, Institute of Pathology, Jena University Hospital, 07740 Jena (Germany); Richter, Petra, E-mail: P.Richter@med.uni-jena.de [Center for Molecular Biomedicine, Institute of Pathology, Jena University Hospital, 07740 Jena (Germany); Chen, Yuan, E-mail: Yuan.Chen@med.uni-jena.de [Center for Molecular Biomedicine, Institute of Pathology, Jena University Hospital, 07740 Jena (Germany); Franz, Marcus, E-mail: Marcus.Franz@med.uni-jena.de [Clinic of Internal Medicine I, Jena University Hospital, 07740 Jena (Germany); Liebmann, Claus, E-mail: Claus.Liebmann@uni-jena.de [Institute of Biochemistry and Biophysics, Friedrich Schiller University Jena, 07740 Jena (Germany)

    2014-04-01

    Crosstalk between carcinoma associated fibroblasts (CAFs) and oral squamous cell carcinoma (OSCC) cells is suggested to mediate phenotype transition of cancer cells as a prerequisite for tumour progression, to predict patients’ outcome, and to influence the efficacy of EGFR inhibitor therapies. Here we investigate the influence of activated fibroblasts as a model for CAFs on phenotype and EGFR signalling in OSCC cells in vitro. For this, immortalised hTERT-BJ1 fibroblasts were activated with TGFβ1 and PDGFAB to generate a myofibroblast or proliferative phenotype, respectively. Conditioned media (FCM{sub TGF}, FCM{sub PDGF}) were used to stimulate PE/CA-PJ15 OSCC cells. Results were compared to the effect of conditioned media of non-stimulated fibroblasts (FCM{sub B}). FCM{sub TGF} stimulation leads to an up-regulation of vimentin in the OSCC cells and an enhancement of invasive behaviour, indicating EMT-like effects. Similarly, FCM{sub TGF}≫FCM{sub PDGF} induced up-regulation of EGFR, but not of ErbB2/ErbB3. In addition, we detected an increase in basal activities of ERK, PI3K/Akt and Stat3 (FCM{sub TGF}>FCM{sub PDGF}) accompanied by protein interaction of vimentin with pERK. These effects are correlated with an increased proliferation. In summary, our results suggest that the activated myofibroblast phenotype provides soluble factors which are able to induce EMT-like phenomena and to increase EGFR signalling as well as cell proliferation in OSCC cells. Our results indicate a possible influence of activated myofibroblasts on EGFR-inhibitor therapy. Therefore, CAFs may serve as promising novel targets for combined therapy strategies. - Highlights: • A cell culture model for cancer associated fibroblasts is described. • The mutual interaction with OSCC cells leads to up-regulation of EGFR in tumour cells. • mCAF induces EGFR downstream signalling with increased proliferation in OSCC. • Erk activation is associated with protein interaction with vimentin

  9. Unravelling the pivotal role of Alix in MVB sorting and silencing of the activated EGFR.

    Science.gov (United States)

    Sun, Sheng; Zhou, Xi; Zhang, Wei; Gallick, Gary E; Kuang, Jian

    2015-03-15

    Endosomal sorting complex required for transport (ESCRT)-III-mediated membrane invagination and scission are a critical step in multivesicular body (MVB) sorting of ubiquitinated membrane receptors, and generally thought to be required for degradation of these receptors in lysosomes. The adaptor protein Alix is critically involved in multiple ESCRT-III-mediated, membrane-remodelling processes in mammalian cells. However, Alix knockdown does not inhibit degradation of the activated epidermal growth factor receptor (EGFR) in mammalian cell lines, leading to a widely held notion that Alix is not critically involved in MVB sorting of ubiquitinated membrane receptors in mammalian cells. In the present study, we demonstrate that, despite its non-essential role in degradation of the activated EGFR, Alix plays a critical role in its MVB sorting and silencing Epidermal growth factor (EGF) stimulation of mammalian cell lines induces Alix's interaction with the ubiquitinated EGFR via the Alix V domain, and increases Alix's association with membrane-bound charged multivesicular body protein 4 (CHMP4) via the Alix Bro1 domain. Under both continuous and pulse-chase EGF stimulation conditions, inhibition of Alix's interaction with membrane-bound CHMP4, inhibition of Alix dimerization through the V domain or Alix knockdown dramatically inhibits MVB sorting of the activated EGFR and promotes sustained activation of extracellular-signal regulated kinase (ERK)1/2. Under the continuous EGF stimulation conditions, these cell treatments also retard degradation of the activated EGFR. These findings indicate that Alix is critically involved in MVB sorting of ubiquitinated membrane receptors in mammalian cells.

  10. Model-based Analysis of HER Activation in Cells Co-Expressing EGFR, HER2 and HER3.

    Energy Technology Data Exchange (ETDEWEB)

    Shankaran, Harish; Zhang, Yi; Tan, Yunbing; Resat, Haluk

    2013-08-22

    The HER/ErbB family of receptor tyrosine kinases drive critical responses in normal physiology and cancer, and the expression levels of the various HER receptors are critical determinants of clinical outcomes. HER activation is driven by the formation of various dimer complexes between members of this receptor family. The HER dimer types can have differential effects on downstream signaling and phenotypic outcomes. We constructed an integrated mathematical model of HER activation and trafficking to quantitatively link receptor expression levels to dimerization and activation. We parameterized the model with a comprehensive set of HER phosphorylation and abundance data collected in a panel of human mammary epithelial cells expressing varying levels of EGFR, HER2 and HER3. Although parameter estimation yielded multiple solutions, predictions for dimer phosphorylation were in agreement with each other. We validated the model using experiments where pertuzumab was used to block HER2 dimerization. We used the model to predict HER dimerization and activation patterns in a panel of epithelial cells lines with known HER expression levels. Simulations over the range of expression levels seen in various cell lines indicate that: i) EGFR phosphorylation is driven by HER1/1 and HER1/2 dimers, and not HER1/3 dimers, ii) HER1/2 and HER2/3 dimers both contribute significantly to HER2 activation with the EGFR expression level determining the relative importance of these species, and iii) the HER2/3 dimer is largely responsible for HER3 activation. The model can be used to predict phosphorylated dimer levels for any given HER expression profile. This information in turn can be used to quantify the potencies of the various HER dimers, and can potentially inform personalized therapeutic approaches.

  11. A combination of gefitinib and FOLFOX-4 as first-line treatment in advanced colorectal cancer patients. A GISCAD multicentre phase II study including a biological analysis of EGFR overexpression, amplification and NF-kB activation

    Science.gov (United States)

    Cascinu, S; Berardi, R; Salvagni, S; Beretta, G D; Catalano, V; Pucci, F; Sobrero, A; Tagliaferri, P; Labianca, R; Scartozzi, M; Crocicchio, F; Mari, E; Ardizzoni, A

    2007-01-01

    Interesting activity has been reported by combining chemotherapy with cetuximab. An alternative approach for blocking EGFR function has been the development of small-molecule inhibitors of tyrosine kinase domain such as gefitinib. We designed a multicentre phase II study in advanced colorectal cancer combining gefitinib+FOLFOX in order to determine the activity and to relate EGFR expression and gene amplification and NF-kB activation to therapeutic results. Patients received FOLFOX-4 regimen plus gefitinib as first-line treatment. Tumour samples were analysed for EGFR protein expression by immunohistochemical analysis and for EGFR gene amplification by fluorescence in situ hybridisation (FISH), chromogenic in situ hybridisation (CISH) and NF-kB activation. Forty-three patients were enrolled into this study; 15 patients experienced a partial response (response rate=34.9%), whereas other 12 (27.9%) had a stable disease. Median progression-free survival (PFS) was 7.8 months and median overall survival (OS) was 13.9 months. We did not find any relationship with EGFR overexpression, gene amplification, while NF-kB activation was associated with a resistance to therapy. Gefitinib does not seem to increase the activity of FOLFOX in advanced colorectal cancer even in patients overexpressing EGFR or with EGFR amplification. Furthermore, while NF-kB activation seems to predict resistance to chemotherapy as demonstrated ‘in vitro' models, gefitinib does not overcome this mechanism of resistance, as reported for cetuximab. PMID:18059397

  12. Alpha6beta4 integrin crosslinking induces EGFR clustering and promotes EGF-mediated Rho activation in breast cancer

    Directory of Open Access Journals (Sweden)

    Woodward Wendy A

    2009-05-01

    Full Text Available Abstract Background The α6β4 integrin is overexpressed in the basal subtype of breast cancer and plays an important role in tumor cell motility and invasion. EGFR is also overexpressed in the basal subtype of breast cancer, and crosstalk between α6β4 integrin and EGFR appears to be important in tumor progression. Methods We evaluated the effects of α6β4 crosslinking on the distribution and function of EGFR in breast carcinoma cell line MDA-MB-231. Receptor distribution was evaluated by fluorescence microscopy and multispectral imaging flow cytometry, and ligand-mediated EGFR signaling was evaluated using Western blots and a Rho pull-down assay. Results Antibody-mediated crosslinking of α6β4 integrin was sufficient to induce cell-surface clustering of not only α6β4 but also EGFR in nonadherent cells. The induced clustering of EGFR was observed minimally after 5 min of integrin crosslinking but was more prominent after 15 min. EGFR clustering had minimal effect on the phosphorylation of Akt or Erk1,2 in response to EGF in suspended cells or in response to HB-EGF in adherent cells. However, EGFR clustering induced by crosslinking α6β4 had a marked effect on Rho activation in response to EGF. Conclusion Crosslinking α6β4 integrin in breast carcinoma cells induces EGFR clustering and preferentially promotes Rho activation in response to EGF. We hypothesize that this integrin-EGFR crosstalk may facilitate tumor cell cytoskeletal rearrangements important for tumor progression.

  13. Quinazoline-1-deoxynojirimycin hybrids as high active dual inhibitors of EGFR and α-glucosidase.

    Science.gov (United States)

    Zhang, Yaling; Gao, Hongliang; Liu, Renjie; Liu, Juan; Chen, Li; Li, Xiabing; Zhao, Lijun; Wang, Wei; Li, Baolin

    2017-09-15

    A series of novel quinazoline-1-deoxynojirimycin hybrids were designed, synthesized and evaluated for their inhibitory activities against two drug target enzymes, epidermal growth factor receptor (EGFR) tyrosine kinase and α-glucosidase. Some synthesized compounds exhibited significantly inhibitory activities against the tested enzymes. Comparing with reference compounds gefitinib and lapatinib, compounds 7d, 8d, 9b and 9d showed higher inhibitory activities against EGFR (IC50: 1.79-10.71nM). Meanwhile the inhibitory activities of 7d, 8d and 9c against α-glucosidase (IC50=0.14, 0.09 and 0.25µM, respectively) were obvious higher than that of miglitol (IC50=2.43µM), a clinical using α-glucosidase inhibitor. Interestingly, compound 9d as a dual inhibitor showed high inhibitory activity to EGFRwt tyrosine kinase (IC50=1.79nM), also to α-glucosidase (IC50=0.39µM). The work could be very useful starting point for developing a new series of enzyme inhibitors targeting EGFR and/or α-glucosidase. Copyright © 2017 Elsevier Ltd. All rights reserved.

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

    Energy Technology Data Exchange (ETDEWEB)

    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

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

    Directory of Open Access Journals (Sweden)

    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.

  16. Antibacterial and EGFR-Tyrosine Kinase Inhibitory Activities of Polyhydroxylated Xanthones from Garcinia succifolia

    Directory of Open Access Journals (Sweden)

    Susawat Duangsrisai

    2014-11-01

    Full Text Available Chemical investigation of the methanol extract of the wood of Garcinia succifolia Kurz (Clusiaceae led to the isolation of 1,5-dihydroxyxanthone (1, 1,7-dihydroxyxanthone (2, 1,3,7-trihydroxyxanthone (3, 1,5,6-trihydroxyxanthone (4, 1,6,7-trihydroxyxanthone (5, and 1,3,6,7-tetrahydroxyxanthone (6. All of the isolated xanthones were evaluated for their antibacterial activity against bacterial reference strains, two Gram-positive (Staphylococcus aureus ATTC 25923, Bacillus subtillis ATCC 6633 and two Gram-negative (Escherichia coli ATCC 25922 and Pseudomonas aeruginosa ATCC 27853, and environmental drug-resistant isolates (S. aureus B1, Enteroccoccus faecalis W1, and E. coli G1, as well as for their epidermal growth factor receptor (EGFR of tyrosine kinase inhibitory activity. Only 1,5,6-trihydroxy-(4, 1,6,7-trihydroxy-(5, and 1,3,6,7-tetrahydroxyxanthones (6 exhibited antibacterial activity against Gram-positive bacteria, however none was active against vancomycin-resistant E. faecalis. Additionally, 1,7-dihydroxyxanthone (2 showed synergism with oxacillin, but not with ampicillin. On the other hand, only 1,5-dihydroxyxanthone (1 and 1,7-dihydroxyxanthone (2 were found to exhibit the EGFR-tyrosine kinase inhibitory activity, with IC50 values of 90.34 and 223 nM, respectively.

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

    Directory of Open Access Journals (Sweden)

    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.

  18. Deoxycholic acid mediates non-canonical EGFR-MAPK activation through the induction of calcium signaling in colon cancer cells.

    Science.gov (United States)

    Centuori, Sara M; Gomes, Cecil J; Trujillo, Jesse; Borg, Jamie; Brownlee, Joshua; Putnam, Charles W; Martinez, Jesse D

    2016-07-01

    Obesity and a western diet have been linked to high levels of bile acids and the development of colon cancer. Specifically, increased levels of the bile acid deoxycholic acid (DCA), an established tumor promoter, has been shown to correlate with increased development of colorectal adenomas and progression to carcinoma. Herein we investigate the mechanism by which DCA leads to EGFR-MAPK activation, a candidate mechanism by which DCA may promote colorectal tumorigenesis. DCA treated colon cancer cells exhibited strong and prolonged activation of ERK1/2 when compared to EGF treatment alone. We also showed that DCA treatment prevents EGFR degradation as opposed to the canonical EGFR recycling observed with EGF treatment. Moreover, the combination of DCA and EGF treatment displayed synergistic activity, suggesting DCA activates MAPK signaling in a non-canonical manner. Further evaluation showed that DCA treatment increased intracellular calcium levels and CAMKII phosphorylation, and that blocking calcium with BAPTA-AM abrogated MAPK activation induced by DCA, but not by EGF. Finally we showed that DCA-induced CAMKII leads to MAPK activation through the recruitment of c-Src. Taken together, we demonstrated that DCA regulates MAPK activation through calcium signaling, an alternative mechanism not previously recognized in human colon cancer cells. Importantly, this mechanism allows for EGFR to escape degradation and thus achieve a constitutively active state, which may explain its tumor promoting effects. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. Increased concentrations of growth factors and activation of the EGFR system in breast cancer

    DEFF Research Database (Denmark)

    Aalund Olsen, Dorte; Bechmann, Troels; Østergaard, Birthe

    2012-01-01

    In this study the total and phosphorylated amount of epidermal growth factor receptor 1 (EGFR) and 2 (HER2) were measured together with EGFR ligands in tissue samples of breast cancer patients in order to investigate interrelations and possible prognostic values....

  20. Electromagnetic fields induce neural differentiation of human bone marrow derived mesenchymal stem cells via ROS mediated EGFR activation.

    Science.gov (United States)

    Park, Jeong-Eun; Seo, Young-Kwon; Yoon, Hee-Hoon; Kim, Chan-Wha; Park, Jung-Keug; Jeon, Songhee

    2013-03-01

    Even though the inducing effect of electromagnetic fields (EMF) on the neural differentiation of human bone marrow mesenchymal stem cells (hBM-MSCs) is a distinctive, the underlying mechanism of differentiation remains unclear. To find out the signaling pathways involved in the neural differentiation of BM-MSCs by EMF, we examined the CREB phosphorylation and Akt or ERK activation as an upstream of CREB. In hBM-MSCs treated with ELF-EMF (50 Hz, 1 mT), the expression of neural markers such as NF-L, MAP2, and NeuroD1 increased at 6 days and phosphorylation of Akt and CREB but not ERK increased at 90 min in BM-MSCs. Moreover, EMF increased phosphorylation of epidermal growth factor receptor (EGFR) as an upstream receptor tyrosine kinase of PI3K/Akt at 90 min. It has been well documented that ELF-MF exposure may alter cellular processes by increasing intracellular reactive oxygen species (ROS) concentrations. Thus, we examined EMF-induced ROS production in BM-MSCs. Moreover, pretreatment with a ROS scavenger, N-acetylcystein, and an EGFR inhibitor, AG-1478, prevented the phosphorylation of EGFR and downstream molecules. These results suggest that EMF induce neural differentiation through activation of EGFR signaling and mild generation of ROS. Copyright © 2013 Elsevier Ltd. All rights reserved.

  1. Helicobacter pylori Induces Serine Phosphorylation of EGFR via Novel TAK1-p38 Activation Pathway in an HB-EGF-Independent Manner.

    Science.gov (United States)

    Zaidi, Syed Faisal; Refaat, Alaa; Zhou, Yue; Sualeh Muhammad, Jibran; Shin, Myoung-Sook; Saiki, Ikuo; Sakurai, Hiroaki; Sugiyama, Toshiro

    2015-10-01

    The interaction of Helicobacter pylori with gastric epithelial cells can result in the activation of transcription factor NF-κB via TGF-β-activated kinase 1 (TAK1). In this study, we have demonstrated the role of H. pylori in the activation of EGFR via TAK1-mediated phosphorylation of p38. Gastric epithelial AGS or MKN-45 cells were co-cultured with wild-type or cagA(-) H. pylori strains. H. pylori was added to the cells, and the activation of EGFR, p65 (NF-κB) subunit, p38, ERK, and TAK1 was examined by Western blotting. Infected cells were pretreated with or without ligands, chemical inhibitors, anti-HB-EGF antibody, and siRNAs to evaluate the effects on phosphorylation of various EGFR residues. Fluorescence microscopy and flow cytometry were performed to detect the internalization of EGFR. Incubating cells with wild-type and CagA(-) H. pylori strains resulted in the rapid and transient phosphorylation of serine residues of EGFR. RNAi experiments using siRNA against TAK1 and p38 pathways blocked the phosphorylation of serine residue. Immunofluorescence and flow cytometry revealed that EGFR was internalized in H. pylori-infected cells after EGFR phosphorylation in a p38-dependent manner. In contrast, pretreatment with gefitinib and anti-HB-EGF antibody did not block both the phosphorylation and internalization of EGFR. Helicobacter pylori induces internalization of EGFR via novel TAK1-p38-serine activation pathway which is independent of HB-EGF. The interaction between TAK1 and EGFR in H. pylori-infected cells might open new dimensions in understanding H. pylori-associated gastric carcinogenesis. © 2015 John Wiley & Sons Ltd.

  2. The HOXB7 protein renders breast cancer cells resistant to tamoxifen through activation of the EGFR pathway.

    Science.gov (United States)

    Jin, Kideok; Kong, Xiangjun; Shah, Tariq; Penet, Marie-France; Wildes, Flonne; Sgroi, Dennis C; Ma, Xiao-Jun; Huang, Yi; Kallioniemi, Anne; Landberg, Goran; Bieche, Ivan; Wu, Xinyan; Lobie, Peter E; Davidson, Nancy E; Bhujwalla, Zaver M; Zhu, Tao; Sukumar, Saraswati

    2012-02-21

    Multiple factors including long-term treatment with tamoxifen are involved in the development of selective estrogen receptor (ER) modulator resistance in ERα-positive breast cancer. Many underlying molecular events that confer resistance are known but a unifying theme is yet to be revealed. In this report, we provide evidence that HOXB7 overexpression renders MCF-7 cells resistant to tamoxifen via cross-talk between receptor tyrosine kinases and ERα signaling. HOXB7 is an ERα-responsive gene. Extended treatment of MCF-7 cells with tamoxifen resulted in progressively increasing levels of HOXB7 expression, along with EGFR and EGFR ligands. Up-regulation of EGFR occurs through direct binding of HOXB7 to the EGFR promoter, enhancing transcriptional activity. Finally, higher expression levels of HOXB7 in the tumor significantly correlated with poorer disease-free survival in ERα-positive patients with breast cancer on adjuvant tamoxifen monotherapy. These studies suggest that HOXB7 acts as a key regulator, orchestrating a major group of target molecules in the oncogenic hierarchy. Functional antagonism of HOXB7 could circumvent tamoxifen resistance.

  3. Antitumor activity of sorafenib in human cancer cell lines with acquired resistance to EGFR and VEGFR tyrosine kinase inhibitors.

    Directory of Open Access Journals (Sweden)

    Floriana Morgillo

    Full Text Available Treatment of non small cell lung cancer (NSCLC and colorectal cancer (CRC have substantially changed in the last years with the introduction of epidermal growth factor receptor (EGFR inhibitors in the clinical practice. The understanding of mechanisms which regulate cells sensitivity to these drugs is necessary for their optimal use.An in vitro model of acquired resistance to two tyrosine kinase inhibitors (TKI targeting the EGFR, erlotinib and gefitinib, and to a TKI targeting EGFR and VEGFR, vandetanib, was developed by continuously treating the human NSCLC cell line CALU-3 and the human CRC cell line HCT116 with escalating doses of each drug. MTT, western blot analysis, migration, invasion and anchorage-independent colony forming assays were conducted in vitro and experiments with established xenografts in athymic nude mice were performed in vivo in sensitive, wild type (WT and TKI-resistant CALU-3 and HCT116 cell lines.As compared to WT CALU-3 and HCT116 human cancer cells, TKI-resistant cell lines showed a significant increase in the levels of activated, phosphorylated AKT, MAPK, and of survivin. Considering the role of RAS and RAF as downstream signals of both the EGFR and VEGFR pathways, we treated resistant cells with sorafenib, an inhibitor of C-RAF, B-RAF, c-KIT, FLT-3, RET, VEGFR-2, VEGFR-3, and PDGFR-β. Sorafenib reduced the activation of MEK and MAPK and caused an inhibition of cell proliferation, invasion, migration, anchorage-independent growth in vitro and of tumor growth in vivo of all TKI-resistant CALU-3 and HCT116 cell lines.These data suggest that resistance to EGFR inhibitors is predominantly driven by the RAS/RAF/MAPK pathway and can be overcame by treatment with sorafenib.

  4. Determination of EGFR Endocytosis Kinetic by Auto-Regulatory Association of PLD1 with ?2

    OpenAIRE

    Lee, Jun Sung; Kim, Il Shin; Kim, Jung Hwan; Cho, Wonhwa; Suh, Pann-Ghill; Ryu, Sung Ho

    2009-01-01

    Background Upon ligand binding, cell surface signaling receptors are internalized through a process tightly regulated by endocytic proteins and adaptor protein 2 (AP2) to orchestrate them. Although the molecular identities and roles of endocytic proteins are becoming clearer, it is still unclear what determines the receptor endocytosis kinetics which is mainly regulated by the accumulation of endocytic apparatus to the activated receptors. Methodology/Principal Findings Here we employed the k...

  5. The activation of G protein-coupled estrogen receptor induces relaxation via cAMP as well as potentiates contraction via EGFR transactivation in porcine coronary arteries.

    Directory of Open Access Journals (Sweden)

    Xuan Yu

    Full Text Available Estrogen exerts protective effects against cardiovascular diseases in premenopausal women, but is associated with an increased risk of both coronary heart disease and stroke in older postmenopausal women. Studies have shown that activation of the G-protein-coupled estrogen receptor 1 (GPER can cause either relaxation or contraction of arteries. It is highly likely that these dual actions of GPER may contribute to the seemingly paradoxical effects of estrogen in regulating coronary artery function. The objective of this study was to test the hypothesis that activation of GPER enhances agonist-stimulated porcine coronary artery contraction via epidermal growth factor receptor (EGFR transactivation and its downstream extracellular signal-regulated kinases (ERK1/2 pathway. Isometric tension studies and western blot were performed to determine the effect of GPER activation on coronary artery contraction. Our findings demonstrated that G-1 caused concentration-dependent relaxation of ET-1-induced contraction, while pretreatment of arterial rings with G-1 significantly enhanced ET-1-induced contraction. GPER antagonist, G-36, significantly inhibited both the G-1-induced relaxation effect and G-1-enhanced ET-1 contraction. Gallein, a Gβγ inhibitor, significantly increased G-1-induced relaxation, yet inhibited G-1-enhanced ET-1-mediated contraction. Similarly, inhibition of EGFR with AG1478 or inhibition of Src with phosphatase 2 further increased G-1-induced relaxation responses in coronary arteries, but decreased G-1-enhanced ET-1-induced contraction. Western blot experiments in porcine coronary artery smooth muscle cells (PCASMC showed that G-1 increased tyrosine phosphorylation of EGFR, which was inhibited by AG-1478. Furthermore, enzyme-linked immunosorbent assays showed that the level of heparin-binding EGF (HB-EGF released by ET-1 treatment increased two-fold; whereas pre-incubation with G-1 further increased ET-1-induced HB-EGF release to four

  6. Up-regulation of fatty acid synthase induced by EGFR/ERK activation promotes tumor growth in pancreatic cancer

    Energy Technology Data Exchange (ETDEWEB)

    Bian, Yong, E-mail: drbiany@126.com [Department of Science and Technology, Nanjing University of Chinese Medicine, 210023 (China); Yu, Yun [College of Pharmacy, Nanjing University of Chinese Medicine, 210023 (China); Wang, Shanshan; Li, Lin [Department of Science and Technology, Nanjing University of Chinese Medicine, 210023 (China)

    2015-08-07

    Lipid metabolism is dysregulated in many human diseases including atherosclerosis, type 2 diabetes and cancers. Fatty acid synthase (FASN), a key lipogenic enzyme involved in de novo lipid biosynthesis, is significantly upregulated in multiple types of human cancers and associates with tumor progression. However, limited data is available to understand underlying biological functions and clinical significance of overexpressed FASN in pancreatic ductal adenocarcinoma (PDAC). Here, upregulated FASN was more frequently observed in PDAC tissues compared with normal pancreas in a tissue microarray. Kaplan–Meier survival analysis revealed that high expression level of FASN resulted in a significantly poor prognosis of PDAC patients. Knockdown or inhibition of endogenous FASN decreased cell proliferation and increased cell apoptosis in HPAC and AsPC-1 cells. Furthermore, we demonstrated that EGFR/ERK signaling accounts for elevated FASN expression in PDAC as ascertained by performing siRNA assays and using specific pharmacological inhibitors. Collectively, our results indicate that FASN exhibits important roles in tumor growth and EGFR/ERK pathway is responsible for upregulated expression of FASN in PDAC. - Highlights: • Increased expression of FASN indicates a poor prognosis in PDAC. • Elevated FASN favors tumor growth in PDAC in vitro. • Activation of EGFR signaling contributes to elevated FASN expression.

  7. Protein Kinase G facilitates EGFR-mediated cell death in MDA-MB-468 cells

    Energy Technology Data Exchange (ETDEWEB)

    Jackson, Nicole M.; Ceresa, Brian P., E-mail: brian.ceresa@louisville.edu

    2016-08-15

    The Epidermal Growth Factor Receptor (EGFR) is a transmembrane receptor tyrosine kinase with critical implications in cell proliferation, migration, wound healing and the regulation of apoptosis. However, the EGFR has been shown to be hyper-expressed in a number of human malignancies. The MDA-MB-468 metastatic breast cell line is one example of this. This particular cell line hyper-expresses the EGFR and undergoes EGFR-mediated apoptosis in response to EGF ligand. The goal of this study was to identify the kinases that could be potential intermediates for the EGFR-mediated induction of apoptosis intracellularly. After identifying Cyclic GMP-dependent Protein Kinase G (PKG) as a plausible intermediate, we wanted to determine the temporal relationship of these two proteins in the induction of apoptosis. We observed a dose-dependent decrease in MDA-MB-468 cell viability, which was co-incident with increased PKG activity as measured by VASPSer239 phosphorylation. In addition, we observed a dose dependent decrease in cell viability, as well as an increase in apoptosis, in response to two different PKG agonists, 8-Bromo-cGMP and 8-pCPT-cGMP. MDA-MB-468 cells with reduced PKG activity had attenuated EGFR-mediated apoptosis. These findings indicate that PKG does not induce cell death via transphosphorylation of the EGFR. Instead, PKG activity occurs following EGFR activation. Together, these data indicate PKG as an intermediary in EGFR-mediated cell death, likely via apoptotic pathway.

  8. Calcium-activated chloride channel ANO1 promotes breast cancer progression by activating EGFR and CAMK signaling.

    Science.gov (United States)

    Britschgi, Adrian; Bill, Anke; Brinkhaus, Heike; Rothwell, Christopher; Clay, Ieuan; Duss, Stephan; Rebhan, Michael; Raman, Pichai; Guy, Chantale T; Wetzel, Kristie; George, Elizabeth; Popa, M Oana; Lilley, Sarah; Choudhury, Hedaythul; Gosling, Martin; Wang, Louis; Fitzgerald, Stephanie; Borawski, Jason; Baffoe, Jonathan; Labow, Mark; Gaither, L Alex; Bentires-Alj, Mohamed

    2013-03-12

    The calcium-activated chloride channel anoctamin 1 (ANO1) is located within the 11q13 amplicon, one of the most frequently amplified chromosomal regions in human cancer, but its functional role in tumorigenesis has remained unclear. The 11q13 region is amplified in ∼15% of breast cancers. Whether ANO1 is amplified in breast tumors, the extent to which gene amplification contributes to ANO1 overexpression, and whether overexpression of ANO1 is important for tumor maintenance have remained unknown. We have found that ANO1 is amplified and highly expressed in breast cancer cell lines and primary tumors. Amplification of ANO1 correlated with disease grade and poor prognosis. Knockdown of ANO1 in ANO1-amplified breast cancer cell lines and other cancers bearing 11q13 amplification inhibited proliferation, induced apoptosis, and reduced tumor growth in established cancer xenografts. Moreover, ANO1 chloride channel activity was important for cell viability. Mechanistically, ANO1 knockdown or pharmacological inhibition of its chloride-channel activity reduced EGF receptor (EGFR) and calmodulin-dependent protein kinase II (CAMKII) signaling, which subsequently attenuated AKT, v-src sarcoma viral oncogene homolog (SRC), and extracellular signal-regulated kinase (ERK) activation in vitro and in vivo. Our results highlight the involvement of the ANO1 chloride channel in tumor progression and provide insights into oncogenic signaling in human cancers with 11q13 amplification, thereby establishing ANO1 as a promising target for therapy in these highly prevalent tumor types.

  9. Can EGFR mutation status be reliably determined in pre-operative needle biopsies from adenocarcinomas of the lung?

    DEFF Research Database (Denmark)

    Lindahl, Kim Hein; Sørensen, Flemming Brandt; Jonstrup, Søren Peter

    2015-01-01

    of the tumour volume. The aim of the present investigation was to evaluate the diagnostic performance of this molecular test. We retrospectively included 201 patients with primary adenocarcinoma of the lung. EGFR mutation status (exon 19 deletions and exon 21 L858R point mutation) was evaluated on both pre......The identification of EGFR mutations in non-small-cell lung cancer is important for selecting patients, who may benefit from treatment with EGFR tyrosine kinase inhibitors. The analysis is usually performed on cytological aspirates and/or histological needle biopsies, representing a small fraction......-operative biopsies (131 histological and 70 cytological) and on the surgical specimens, using PCR. Samples with low tumour cell fraction were assigned to laser micro-dissection (LMD). We found nine (4.5%) patients with EGFR mutation in the lung tumour resections, but failed to identify mutation in one...

  10. Highly sensitive and quantitative evaluation of the EGFR T790M mutation by nanofluidic digital PCR.

    Science.gov (United States)

    Iwama, Eiji; Takayama, Koichi; Harada, Taishi; Okamoto, Isamu; Ookubo, Fumihiko; Kishimoto, Junji; Baba, Eishi; Oda, Yoshinao; Nakanishi, Yoichi

    2015-08-21

    The mutation of T790M in EGFR is a major mechanism of resistance to treatment with EGFR-TKIs. Only qualitative detection (presence or absence) of T790M has been described to date, however. Digital PCR (dPCR) analysis has recently been applied to the quantitative detection of target molecules in cancer with high sensitivity. In the present study, 25 tumor samples (13 obtained before and 12 after EGFR-TKI treatment) from 18 NSCLC patients with activating EGFR mutations were evaluated for T790M with dPCR. The ratio of the number of T790M alleles to that of activating mutation alleles (T/A) was determined. dPCR detected T790M in all 25 samples. Although T790M was present in all pre-TKI samples from 13 patients, 10 of these patients had a low T/A ratio and manifested substantial tumor shrinkage during treatment with EGFR-TKIs. In six of seven patients for whom both pre- and post-TKI samples were available, the T/A ratio increased markedly during EGFR-TKI treatment. Highly sensitive dPCR thus detected T790M in all NSCLC patients harboring activating EGFR mutations whether or not they had received EGFR-TKI treatment. Not only highly sensitive but also quantitative detection of T790M is important for evaluation of the contribution of T790M to EGFR-TKI resistance.

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

    Science.gov (United States)

    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.

  12. Induction of Tyrosine Phosphorylation of UV-Activated EGFR by the Beta-Human Papillomavirus Type 8 E6 Leads to Papillomatosis

    Directory of Open Access Journals (Sweden)

    Stefanie Taute

    2017-11-01

    Full Text Available Epidemiological evidence is accumulating that beta-human papillomaviruses (HPV synergize with UV-light in the development of precancerous actinic keratosis, and cutaneous squamous cell carcinomas (cSCC, one of the most common cancers in the Caucasian population. We previously demonstrated the tumorigenic activity of beta-HPV type 8 (HPV8 in the skin of transgenic mice and its cooperation with UV-light. Analysis of underlying mechanisms now showed that in keratinocytes expressing the HPV8E6 protein a transient increase of tyrosine phosphorylated epidermal growth factor receptor (EGFR in response to UV-irradiation occurred, while EGFR tyrosine phosphorylation, i.e., receptor tyrosine kinase (RTK-activity was hardly affected in empty vector control cells. FACS and immunofluorescences revealed that the EGFR was internalized into early endosomes in response to UV-exposure in both, HPV8E6 positive and in control cells, yet with a higher rate in the presence of HPV8E6. Moreover, only in HPV8E6 expressing keratinocytes the EGFR was further sorted into CD63+ intraluminal vesicles, indicative for trafficking to late endosomes. The latter requires the ubiquitination of the EGFR, and in correlation, we could show that only in HPV8E6 positive keratinocytes the EGFR was ubiquitinated upon UV-exposure. HPV8E6 and tyrosine phosphorylated EGFR directly interacted which was enhanced by UV-irradiation. The treatment of K14-HPV8E6 transgenic mice with Canertinib, an inhibitor of the RTK-activity of the EGFR, suppressed skin papilloma growth in response to UV-irradiation. This confirms the crucial role of the RTK-activity of the EGFR in HPV8E6 and UV-mediated papillomatosis in transgenic mice. Taken together, our results demonstrate that HPV8E6 alters the signaling of the UV-activated EGFR and this is a critical step in papilloma formation in response to UV-light in transgenic mice. Our results provide a molecular basis how a beta-HPV type may support early steps of

  13. EGFR Is Regulated by TFAP2C in Luminal Breast Cancer and Is a Target for Vandetanib.

    Science.gov (United States)

    De Andrade, James P; Park, Jung M; Gu, Vivian W; Woodfield, George W; Kulak, Mikhail V; Lorenzen, Allison W; Wu, Vincent T; Van Dorin, Sarah E; Spanheimer, Philip M; Weigel, Ronald J

    2016-03-01

    Expression of TFAP2C in luminal breast cancer is associated with reduced survival and hormone resistance, partially explained through regulation of RET. TFAP2C also regulates EGFR in HER2 breast cancer. We sought to elucidate the regulation and functional role of EGFR in luminal breast cancer. We used gene knockdown (KD) and treatment with a tyrosine kinase inhibitor (TKI) in cell lines and primary cancer isolates to determine the role of RET and EGFR in regulation of p-ERK and tumorigenesis. KD of TFAP2C decreased expression of EGFR in a panel of luminal breast cancers, and chromatin immunoprecipitation sequencing (ChIP-seq) confirmed that TFAP2C targets the EGFR gene. Stable KD of TFAP2C significantly decreased cell proliferation and tumor growth, mediated in part through EGFR. While KD of RET or EGFR reduced proliferation (31% and 34%, P breast cancers to TKIs assessed by ERK activation established a correlation with expression of RET and EGFR. We conclude that TFAP2C regulates EGFR in luminal breast cancer. Response to vandetanib was mediated through the TFAP2C target genes EGFR and RET. Vandetanib may provide a therapeutic effect in luminal breast cancer, and RET and EGFR can serve as molecular markers for response. ©2016 American Association for Cancer Research.

  14. Lapatinib, a dual EGFR and HER2 tyrosine kinase inhibitor, downregulates thymidylate synthase by inhibiting the nuclear translocation of EGFR and HER2.

    Directory of Open Access Journals (Sweden)

    Hwang-Phill Kim

    Full Text Available BACKGROUND: Epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI has been shown to exert a synergistic antitumor effect when combined with fluoropyrimidine. This synergy may be attributable to the downregulation of thymidylate synthase (TS, which is frequently overexpressed in fluoropyrimidine-resistant cancer cells. However, the molecular mechanism underlying the downregulation of TS has yet to be clearly elucidated. METHODOLOGY AND PRINCIPAL FINDINGS: In this study, we demonstrate that lapatinib, a dual TKI of EGFR and HER2 downregulates TS via inhibition of the nuclear translocation of EGFR and HER2. From our cDNA microarray experiments, we determined that a variety of nucleotide synthesis-related genes, including TS, were downregulated with lapatinib, and this was apparent in HER2-amplified cells. Targeted and pharmacologic inhibition assays confirmed that the dual inhibition of EGFR and HER2 is required for the more effective reduction of TS as compared to what was observed with gefitinib or trasutuzumab alone. Additionally, we determined that co-transfected EGFR and HER2 activate the TS gene promoter more profoundly than do either EGFR or HER2 alone. The translocation of EGFR and HER2 into the nucleus and the subsequent activation of the TS promoter were inhibited by lapatinib. CONCLUSIONS AND SIGNIFICANCE: These results demonstrate that lapatinib inhibits the nuclear translocation of EGFR and HER2 and downregulates TS, thus sensitizing cancer cells to fluoropyrimidine.

  15. Lapatinib, a Dual EGFR and HER2 Tyrosine Kinase Inhibitor, Downregulates Thymidylate Synthase by Inhibiting the Nuclear Translocation of EGFR and HER2

    Science.gov (United States)

    Kim, Hwang-Phill; Yoon, Young-Kwang; Kim, Jin-Won; Han, Sae-Won; Hur, Hyung-Seok; Park, Jinah; Lee, Ju-Hee; Oh, Do-Youn; Im, Seock-Ah; Bang, Yung-Jue; Kim, Tae-You

    2009-01-01

    Background Epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) has been shown to exert a synergistic antitumor effect when combined with fluoropyrimidine. This synergy may be attributable to the downregulation of thymidylate synthase (TS), which is frequently overexpressed in fluoropyrimidine-resistant cancer cells. However, the molecular mechanism underlying the downregulation of TS has yet to be clearly elucidated. Methodology and Principal Findings In this study, we demonstrate that lapatinib, a dual TKI of EGFR and HER2 downregulates TS via inhibition of the nuclear translocation of EGFR and HER2. From our cDNA microarray experiments, we determined that a variety of nucleotide synthesis-related genes, including TS, were downregulated with lapatinib, and this was apparent in HER2-amplified cells. Targeted and pharmacologic inhibition assays confirmed that the dual inhibition of EGFR and HER2 is required for the more effective reduction of TS as compared to what was observed with gefitinib or trasutuzumab alone. Additionally, we determined that co-transfected EGFR and HER2 activate the TS gene promoter more profoundly than do either EGFR or HER2 alone. The translocation of EGFR and HER2 into the nucleus and the subsequent activation of the TS promoter were inhibited by lapatinib. Conclusions and Significance These results demonstrate that lapatinib inhibits the nuclear translocation of EGFR and HER2 and downregulates TS, thus sensitizing cancer cells to fluoropyrimidine. PMID:19529774

  16. Requirement of ERα and basal activities of EGFR and Src kinase in Cd-induced activation of MAPK/ERK pathway in human breast cancer MCF-7 cells

    Energy Technology Data Exchange (ETDEWEB)

    Song, Xiulong, E-mail: songxiulong@hotmail.com; Wei, Zhengxi; Shaikh, Zahir A., E-mail: zshaikh@uri.edu

    2015-08-15

    Cadmium (Cd) is a common environmental toxicant and an established carcinogen. Epidemiological studies implicate Cd with human breast cancer. Low micromolar concentrations of Cd promote proliferation of human breast cancer cells in vitro. The growth promotion of breast cancer cells is associated with the activation of MAPK/ERK pathway. This study explores the mechanism of Cd-induced activation of MAPK/ERK pathway. Specifically, the role of cell surface receptors ERα, EGFR, and Src kinase was evaluated in human breast cancer MCF-7 cells treated with 1–3 μM Cd. The activation of ERK was studied using a serum response element (SRE) luciferase reporter assay. Receptor phosphorylation was detected by Western blot analyses. Cd treatment increased both the SRE reporter activity and ERK1/2 phosphorylation in a concentration-dependent manner. Cd treatment had no effect on reactive oxygen species (ROS) generation. Also, blocking the entry of Cd into the cells with manganese did not diminish Cd-induced activation of MAPK/ERK. These results suggest that the effect of Cd was likely not caused by intracellular ROS generation, but through interaction with the membrane receptors. While Cd did not appear to activate either EGFR or Src kinase, their inhibition completely blocked the Cd-induced activation of ERK as well as cell proliferation. Similarly, silencing ERα with siRNA or use of ERα antagonist blocked the effects of Cd. Based on these results, it is concluded that not only ERα, but also basal activities of EGFR and Src kinase are essential for Cd-induced signal transduction and activation of MAPK/ERK pathway for breast cancer cell proliferation. - Highlights: • Low micromolar concentrations of Cd rapidly activate ERK1/2 in MCF-7 cells. • Signal transduction and resulting cell proliferation require EGFR, ERα, and Src. • These findings implicate Cd in promotion of breast cancer.

  17. 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.

  18. Cell Cycle Synchronization of HeLa Cells to Assay EGFR Pathway Activation.

    Science.gov (United States)

    Wee, Ping; Wang, Zhixiang

    2017-01-01

    Progression through the cell cycle causes changes in the cell's signaling pathways that can alter EGFR signal transduction. Here, we describe drug-derived protocols to synchronize HeLa cells in various phases of the cell cycle, including G1 phase, S phase, G2 phase, and mitosis, specifically in the mitotic stages of prometaphase, metaphase, and anaphase/telophase. The synchronization procedures are designed to allow synchronized cells to be treated for EGF and collected for the purpose of Western blotting for EGFR signal transduction components.S phase synchronization is performed by thymidine block, G2 phase with roscovitine, prometaphase with nocodazole, metaphase with MG132, and anaphase/telophase with blebbistatin. G1 phase synchronization is performed by culturing synchronized mitotic cells obtained by mitotic shake-off. We also provide methods to validate the synchronization methods. For validation by Western blotting, we provide the temporal expression of various cell cycle markers that are used to check the quality of the synchronization. For validation of mitotic synchronization by microscopy, we provide a guide that describes the physical properties of each mitotic stage, using their cellular morphology and DNA appearance. For validation by flow cytometry, we describe the use of imaging flow cytometry to distinguish between the phases of the cell cycle, including between each stage of mitosis.

  19. Curcumin Induces EGFR Degradation in Lung Adenocarcinoma and Modulates p38 Activation in Intestine: The Versatile Adjuvant for Gefitinib Therapy

    OpenAIRE

    Jen-Yi Lee; Yee-Ming Lee; Gee-Chen Chang; Sung-Liang Yu; Wan-Yu Hsieh; Jeremy J W Chen; Huei-Wen Chen; Pan-Chyr Yang

    2011-01-01

    BACKGROUND: Non-small cell lung cancer (NSCLC) patients with L858R or exon 19 deletion mutations in epidermal growth factor receptor (EGFR) have good responses to the tyrosine kinase inhibitor (TKI), gefitinib. However, patients with wild-type EGFR and acquired mutation in EGFR T790M are resistant to gefitinib treatment. Here, we showed that curcumin can improve the efficiency of gefitinib in the resistant NSCLC cells both in vitro and in vivo models. METHODS/PRINCIPAL FINDINGS: After screeni...

  20. A Rapid and Sensitive Method for Detection of the T790M Mutation of EGFR in Plasma DNA.

    Science.gov (United States)

    Kimura, Hideharu; Nishikawa, Shingo; Koba, Hayato; Yoneda, Taro; Sone, Takashi; Kasahara, Kazuo

    2016-01-01

    Epidermal growth factor receptor (EGFR) T790M mutation is associated with resistance to EGFR tyrosine kinase inhibitors' (EGFR-TKIs) in non-small cell lung cancer (NSCLC). The aims of this study are to develop a blood-based, non-invasive approach to detecting the EGFR T790M mutation in advanced NSCLC patients, using PointMan™ EGFR DNA Enrichment Kit which is a novel method for selective amplification of genotype specific sequences.Pairs of blood samples and tumor tissues were collected from NSCLC patients with an EGFR activating mutation and who were resistant to EGFR-TKI treatment. EGFR T790M mutation in plasma DNA were detected using the PointMan™ EGFR DNA Enrichment Kit. The concentrations of plasma DNA were determined using quantitative real-time PCR.Of the 52 patients enrolled in this study, 41 of the patients' plasma samples were collected at post EGFR-TKIs. Nineteen (46.3 %) of the 41 patients had an EGFR T790M mutation in their plasma DNA as detected using the PointMan™ EGFR DNA Enrichment Kit after disease progression to EFGR-TKI. Of 11 cases with a detected T790M mutation from tumor tissues, 10 (90.9 %) also had a detectable T790M mutation in the plasma DNA. There was no difference in the progression-free survival between patients with T790M and those without T790M.The PointMan™ proved to be a useful method for determining plasma EGFR T790M mutation status.

  1. 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.

  2. CXCL12/CXCR4 Axis Activation Mediates Prostate Myofibroblast Phenoconversion through Non-Canonical EGFR/MEK/ERK Signaling.

    Directory of Open Access Journals (Sweden)

    José A Rodríguez-Nieves

    Full Text Available Benign prostate hyperplasia (BPH, an enlargement of the prostate common in aging in men, is associated with urinary voiding dysfunction manifest as Lower Urinary Tract Symptoms (LUTS. Although inflammation and abnormal smooth muscle contractions are known to play key roles in the development of LUTS, tissue fibrosis may also be an important and previously unrecognized contributing factor. Tissue fibrosis arises from the unregulated differentiation of fibroblasts or other precursor cell types into myofibroblasts, which is usually accomplished by activation of the TGFβ/TGFβR axis. Previously we reported that the CXC-type chemokines, CXCL5, CXCL8 and CXCL12, which are up-regulated in the aging in the prostate, can drive this differentiation process as well in the absence of TGFβ. Based on this data we sought to elucidate the molecular mechanisms employed by CXCL12, and its receptor CXCR4, during prostate myofibroblast phenoconversion. The results of these studies suggest that CXCL12/CXCR4-mediated signaling events in prostate myofibroblast phenoconversion may proceed through non-canonical pathways that do not depend on TGFβ/TGFβR axis activation or Smad signaling. Here we report that CXCL12/CXCR4 axis activation promotes signaling through the EGFR and downstream MEK/ERK and PI3K/Akt pathways during myofibroblast phenoconversion, but not through TGFβ/TGFβR and downstream Smad signaling, in prostate fibroblasts undergoing myofibroblast phenoconversion. We document that EGFR transactivation is required for CXCL12-mediated signaling and expression of genes associate with myofibroblast phenoconversion (α-SMA, COL1a1. Our study successfully identified TGFβ/TGFβR-independent molecular mechanisms that promote CXCL12/CXCR4-induced myofibroblast phenoconversion. This information may be crucial for the development of novel therapies and potential biomarkers for prostatic fibrosis.

  3. Targeting Signal Transducers and Activators of Transcription-3 (Stat3) As a Novel Strategy In Sensitizing Breast Cancer To Egfr-Targeted Therapy

    Science.gov (United States)

    2008-06-01

    4, 5). (iv) Iressa-treated breast cancer cells and clinical specimens displayed insufficient suppression of STAT3 activity despite with complete... kidney (MDCK) epithelial cells were obtained from American Type Culture Collection. CHO-NEO, CHO-EGFR, and CHO-EGFR-NLS stable cells were derived from...were washed twice with dialysis buffer [2 mmol/L EDTA, 50 mmol/L Tris-HCl (pH 8.0)]and four times with immunoprecip- itation wash buffer [0.5 mol/L

  4. Gene Expression of the EGF System-a Prognostic Model in Non-Small Cell Lung Cancer Patients Without Activating EGFR Mutations

    DEFF Research Database (Denmark)

    Sandfeld-Paulsen, Birgitte; Folkersen, Birgitte Holst; Rasmussen, Torben Riis

    2016-01-01

    OBJECTIVES: Contradicting results have been demonstrated for the expression of the epidermal growth factor receptor (EGFR) as a prognostic marker in non-small cell lung cancer (NSCLC). The complexity of the EGF system with four interacting receptors and more than a dozen activating ligands...

  5. Sulforaphane attenuates EGFR signaling in NSCLC cells.

    Science.gov (United States)

    Chen, Chi-Yuan; Yu, Zhu-Yun; Chuang, Yen-Shu; Huang, Rui-Mei; Wang, Tzu-Chien V

    2015-06-03

    EGFR, a receptor tyrosine kinase (RTK), is frequently overexpressed and mutated in non-small cell lung cancer (NSCLC). Tyrosine kinase inhibitors (TKIs) have been widely used in the treatment of many cancers, including NSCLC. However, intrinsic and acquired resistance to TKI remains a common obstacle. One strategy that may help overcome EGFR-TKI resistance is to target EGFR for degradation. As EGFR is a client protein of heat-shock protein 90 (HSP90) and sulforaphane is known to functionally regulate HSP90, we hypothesized that sulforaphane could attenuate EGFR-related signaling and potentially be used to treat NSCLC. Our study revealed that sulforaphane displayed antitumor activity against NSCLC cells both in vitro and in vivo. The sensitivity of NSCLC cells to sulforaphane appeared to positively correlate with the inhibition of EGFR-related signaling, which was attributed to the increased proteasomal degradation of EGFR. Combined treatment of NSCLC cells with sulforaphane plus another HSP90 inhibitor (17-AAG) enhanced the inhibition of EGFR-related signaling both in vitro and in vivo. We have shown that sulforaphane is a novel inhibitory modulator of EGFR expression and is effective in inhibiting the tumor growth of EGFR-TKI-resistant NSCLC cells. Our findings suggest that sulforaphane should be further explored for its potential clinical applications against NSCLC.

  6. Activating PIK3CA Mutations Induce an Epidermal Growth Factor Receptor (EGFR)/Extracellular Signal-regulated Kinase (ERK) Paracrine Signaling Axis in Basal-like Breast Cancer*

    Science.gov (United States)

    Young, Christian D.; Zimmerman, Lisa J.; Hoshino, Daisuke; Formisano, Luigi; Hanker, Ariella B.; Gatza, Michael L.; Morrison, Meghan M.; Moore, Preston D.; Whitwell, Corbin A.; Dave, Bhuvanesh; Stricker, Thomas; Bhola, Neil E.; Silva, Grace O.; Patel, Premal; Brantley-Sieders, Dana M.; Levin, Maren; Horiates, Marina; Palma, Norma A.; Wang, Kai; Stephens, Philip J.; Perou, Charles M.; Weaver, Alissa M.; O'Shaughnessy, Joyce A.; Chang, Jenny C.; Park, Ben Ho; Liebler, Daniel C.; Cook, Rebecca S.; Arteaga, Carlos L.

    2015-01-01

    Mutations in PIK3CA, the gene encoding the p110α catalytic subunit of phosphoinositide 3-kinase (PI3K) have been shown to transform human mammary epithelial cells (MECs). These mutations are present in all breast cancer subtypes, including basal-like breast cancer (BLBC). Using liquid chromatography-tandem mass spectrometry (LC-MS/MS), we identified 72 protein expression changes in human basal-like MECs with knock-in E545K or H1047R PIK3CA mutations versus isogenic MECs with wild-type PIK3CA. Several of these were secreted proteins, cell surface receptors or ECM interacting molecules and were required for growth of PIK3CA mutant cells as well as adjacent cells with wild-type PIK3CA. The proteins identified by MS were enriched among human BLBC cell lines and pointed to a PI3K-dependent amphiregulin/EGFR/ERK signaling axis that is activated in BLBC. Proteins induced by PIK3CA mutations correlated with EGFR signaling and reduced relapse-free survival in BLBC. Treatment with EGFR inhibitors reduced growth of PIK3CA mutant BLBC cell lines and murine mammary tumors driven by a PIK3CA mutant transgene, all together suggesting that PIK3CA mutations promote tumor growth in part by inducing protein changes that activate EGFR. PMID:25953087

  7. Activating PIK3CA Mutations Induce an Epidermal Growth Factor Receptor (EGFR)/Extracellular Signal-regulated Kinase (ERK) Paracrine Signaling Axis in Basal-like Breast Cancer.

    Science.gov (United States)

    Young, Christian D; Zimmerman, Lisa J; Hoshino, Daisuke; Formisano, Luigi; Hanker, Ariella B; Gatza, Michael L; Morrison, Meghan M; Moore, Preston D; Whitwell, Corbin A; Dave, Bhuvanesh; Stricker, Thomas; Bhola, Neil E; Silva, Grace O; Patel, Premal; Brantley-Sieders, Dana M; Levin, Maren; Horiates, Marina; Palma, Norma A; Wang, Kai; Stephens, Philip J; Perou, Charles M; Weaver, Alissa M; O'Shaughnessy, Joyce A; Chang, Jenny C; Park, Ben Ho; Liebler, Daniel C; Cook, Rebecca S; Arteaga, Carlos L

    2015-07-01

    Mutations in PIK3CA, the gene encoding the p110α catalytic subunit of phosphoinositide 3-kinase (PI3K) have been shown to transform human mammary epithelial cells (MECs). These mutations are present in all breast cancer subtypes, including basal-like breast cancer (BLBC). Using liquid chromatography-tandem mass spectrometry (LC-MS/MS), we identified 72 protein expression changes in human basal-like MECs with knock-in E545K or H1047R PIK3CA mutations versus isogenic MECs with wild-type PIK3CA. Several of these were secreted proteins, cell surface receptors or ECM interacting molecules and were required for growth of PIK3CA mutant cells as well as adjacent cells with wild-type PIK3CA. The proteins identified by MS were enriched among human BLBC cell lines and pointed to a PI3K-dependent amphiregulin/EGFR/ERK signaling axis that is activated in BLBC. Proteins induced by PIK3CA mutations correlated with EGFR signaling and reduced relapse-free survival in BLBC. Treatment with EGFR inhibitors reduced growth of PIK3CA mutant BLBC cell lines and murine mammary tumors driven by a PIK3CA mutant transgene, all together suggesting that PIK3CA mutations promote tumor growth in part by inducing protein changes that activate EGFR. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  8. Activation of ErbB3, EGFR and Erk is essential for growth of human breast cancer cell lines with acquired resistance to fulvestrant

    DEFF Research Database (Denmark)

    Frogne, Thomas; Benjaminsen, Rikke V; Sonne-Hansen, Katrine

    2008-01-01

    growth inhibition of two resistant cell lines. These data indicate that ligand activated ErbB3 and EGFR, and Erk signaling play important roles in fulvestrant resistant cell growth. Furthermore, the decreased level of ErbB4 in resistant cells may facilitate heterodimerization of ErbB3 with EGFR and ErbB2......Seven fulvestrant resistant cell lines derived from the estrogen receptor alpha positive MCF-7 human breast cancer cell line were used to investigate the importance of epidermal growth factor receptor (ErbB1-4) signaling. We found an increase in mRNA expression of EGFR and the ErbB3/ErbB4 ligand...... activation was observed only in the parental MCF-7 cells. The downstream kinases pAkt and pErk were increased in five of seven and in all seven resistant cell lines, respectively. Treatment with the EGFR inhibitor gefitinib preferentially inhibited growth and reduced the S phase fraction in the resistant...

  9. 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

    Science.gov (United States)

    Konstantinopoulos, Panagiotis A.; Vandoros, Gerasimos P.; Karamouzis, Michalis V.; Gkermpesi, Maria; Sotiropoulou-Bonikou, Georgia; Papavassiliou, Athanasios G.

    2007-01-01

    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. PMID:18032824

  10. 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

    Directory of Open Access Journals (Sweden)

    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.

  11. EGFR mutation testing in lung cancer: a review of available methods and their use for analysis of tumour tissue and cytology samples.

    Science.gov (United States)

    Ellison, Gillian; Zhu, Guanshan; Moulis, Alexandros; Dearden, Simon; Speake, Georgina; McCormack, Rose

    2013-02-01

    Activating mutations in the gene encoding epidermal growth factor receptor (EGFR) can confer sensitivity to EGFR tyrosine kinase inhibitors such as gefitinib in patients with advanced non-small-cell lung cancer. Testing for mutations in EGFR is therefore an important step in the treatment-decision pathway. We reviewed reported methods for EGFR mutation testing in patients with lung cancer, initially focusing on studies involving standard tumour tissue samples. We also evaluated data on the use of cytology samples in order to determine their suitability for EGFR mutation analysis. We searched the MEDLINE database for studies reporting on EGFR mutation testing methods in patients with lung cancer. Various methods have been investigated as potential alternatives to the historical standard for EGFR mutation testing, direct DNA sequencing. Many of these are targeted methods that specifically detect the most common EGFR mutations. The development of targeted mutation testing methods and commercially available test kits has enabled sensitive, rapid and robust analysis of clinical samples. The use of screening methods, subsequent to sample micro dissection, has also ensured that identification of more rare, uncommon mutations is now feasible. Cytology samples including fine needle aspirate and pleural effusion can be used successfully to determine EGFR mutation status provided that sensitive testing methods are employed. Several different testing methods offer a more sensitive alternative to direct sequencing for the detection of common EGFR mutations. Evidence published to date suggests cytology samples are viable alternatives for mutation testing when tumour tissue samples are not available.

  12. SAH-induced suppression of voltage-gated K+ (KV) channel currents in parenchymal arteriolar myocytes involves activation of the HB-EGF/EGFR pathway

    OpenAIRE

    Koide, Masayo; Wellman, George C.

    2013-01-01

    Potassium channels play an important role in the regulation of arterial tone and decreased activity of these ion channels has been linked to pial artery vasospasm after subarachnoid hemorrhage (SAH). Our previous work has shown that acute application of a blood component, oxyhemoglobin, caused suppression of voltage-gated K+ (KV) channels through heparin-binding epidermal growth factor-like growth factor (HB-EGF) mediated activation of epidermal growth factor receptor (EGFR). Using patch clam...

  13. Epidermal growth factor receptor (EGFR) and EGFR mutations, function and possible role in clinical trials.

    Science.gov (United States)

    Voldborg, B R; Damstrup, L; Spang-Thomsen, M; Poulsen, H S

    1997-12-01

    The epidermal growth factor receptor (EGFR) is a growth factor receptor that induces cell differentiation and proliferation upon activation through the binding of one of its ligands. The receptor is located at the cell surface, where the binding of a ligand activates a tyrosine kinase in the intracellular region of the receptor. This tyrosine kinase phosphorylates a number of intracellular substrates that activates pathways leading to cell growth, DNA synthesis and the expression of oncogenes such as fos and jun. EGFR is thought to be involved the development of cancer, as the EGFR gene is often amplified, and/or mutated in cancer cells. In this review we will focus on: (I) the structure and function of EGFR, (II) implications of receptor/ligand coexpression and EGFR mutations or overexpression, (III) its effect on cancer cells, (IV) the development of the malignant phenotype and (V) the clinical aspects of therapeutic targeting of EGFR.

  14. SAH-induced suppression of voltage-gated K+ (KV) channel currents in parenchymal arteriolar myocytes involves activation of the HB-EGF/EGFR pathway

    Science.gov (United States)

    Koide, Masayo; Wellman, George C.

    2013-01-01

    Summary Potassium channels play an important role in the regulation of arterial tone and decreased activity of these ion channels has been linked to pial artery vasospasm after subarachnoid hemorrhage (SAH). Our previous work has shown that acute application of a blood component, oxyhemoglobin, caused suppression of voltage-gated K+ (KV) channels through heparin-binding epidermal growth factor-like growth factor (HB-EGF) mediated activation of epidermal growth factor receptor (EGFR). Using patch clamp electrophysiology, we have now examined whether this pathway of KV channel suppression is activated in parenchymal arteriolar myocytes following long-term in vivo exposure to subarachnoid blood. We have found that KV currents, but not large conductance Ca2+ activated or inwardly rectifying K+ channel currents, were decreased in parenchymal arteriolar myocytes freshly isolated from Day-5 SAH model rabbits. Interestingly, parenchymal arteriolar myocytes from control animals were more sensitive to exogenous HB-EGF (IC50: 0.2 ± 0.4 ng/mL) compared to pial arterial myocytes (IC50: 2.4 ±1.3 ng/mL). However, HB-EGF and oxyhemoglobin failed to decrease KV currents in parenchymal arteriolar myocytes from SAH animals, consistent with EGFR activation and KV current suppression by SAH. These data suggest that HB-EGF/EGFR pathway activation contributes to KV current suppression and enhanced parenchymal arteriolar constriction after SAH. PMID:22890666

  15. SAH-induced suppression of voltage-gated K(+) (K (V)) channel currents in parenchymal arteriolar myocytes involves activation of the HB-EGF/EGFR pathway.

    Science.gov (United States)

    Koide, Masayo; Wellman, George C

    2013-01-01

    Potassium channels play an important role in the regulation of arterial tone, and decreased activity of these ion channels has been linked to pial artery vasospasm after subarachnoid hemorrhage (SAH). Our previous work has shown that acute application of a blood component, oxyhemoglobin, caused suppression of voltage-gated K(+) (K(V)) channels through heparin-binding epidermal growth factor-like growth factor (HB-EGF)-mediated activation of epidermal growth factor receptor (EGFR). Using patch clamp electrophysiology, we have now examined whether this pathway of K(V) channel suppression is activated in parenchymal arteriolar myocytes following long-term in vivo exposure to subarachnoid blood. We have found that K(V) currents, but not large conductance Ca(2+) activated or inwardly rectifying K(+) channel currents, were decreased in parenchymal arteriolar myocytes freshly isolated from day 5 SAH model rabbits. Interestingly, parenchymal arteriolar myocytes from control animals were more sensitive to exogenous HB-EGF (half-maximal inhibitory concentration [IC(50)] 0.2 ± 0.4 ng/ml) compared to pial arterial myocytes (IC(50) 2.4 ± 1.3 ng/ml). However, HB-EGF and oxyhemoglobin failed to decrease K(V) currents in parenchymal arteriolar myocytes from SAH animals, consistent with EGFR activation and K(V) current suppression by SAH. These data suggest that HB-EGF/EGFR pathway activation contributes to K(V) current suppression and enhanced parenchymal arteriolar constriction after SAH.

  16. Genome-wide co-localization of active EGFR and downstream ERK pathway kinases mirrors mitogen-inducible RNA polymerase 2 genomic occupancy.

    Science.gov (United States)

    Mikula, M; Skrzypczak, M; Goryca, K; Paczkowska, K; Ledwon, J K; Statkiewicz, M; Kulecka, M; Grzelak, M; Dabrowska, M; Kuklinska, U; Karczmarski, J; Rumienczyk, I; Jastrzebski, K; Miaczynska, M; Ginalski, K; Bomsztyk, K; Ostrowski, J

    2016-12-01

    Genome-wide mechanisms that coordinate expression of subsets of functionally related genes are largely unknown. Recent studies show that receptor tyrosine kinases and components of signal transduction cascades including the extracellular signal-regulated protein kinase (ERK), once thought to act predominantly in the vicinity of plasma membrane and in the cytoplasm, can be recruited to chromatin encompassing transcribed genes. Genome-wide distribution of these transducers and their relationship to transcribing RNA polymerase II (Pol2) could provide new insights about co-regulation of functionally related gene subsets. Chromatin immunoprecipitations (ChIP) followed by deep sequencing, ChIP-Seq, revealed that genome-wide binding of epidermal growth factor receptor, EGFR and ERK pathway components at EGF-responsive genes was highly correlated with characteristic mitogen-induced Pol2-profile. Endosomes play a role in intracellular trafficking of proteins including their nuclear import. Immunofluorescence revealed that EGF-activated EGFR, MEK1/2 and ERK1/2 co-localize on endosomes. Perturbation of endosome internalization process, through the depletion of AP2M1 protein, resulted in decreased number of the EGFR containing endosomes and inhibition of Pol2, EGFR/ERK recruitment to EGR1 gene. Thus, mitogen-induced co-recruitment of EGFR/ERK components to subsets of genes, a kinase module possibly pre-assembled on endosome to synchronize their nuclear import, could coordinate genome-wide transcriptional events to ensure effective cell proliferation. © The Author(s) 2016. Published by Oxford University Press on behalf of Nucleic Acids Research.

  17. EGFR as a potential target for the treatment of pancreatic cancer: dilemma and controversies.

    Science.gov (United States)

    Nedaeinia, Reza; Avan, Amir; Manian, Mostafa; Salehi, Rasoul; Ghayour-Mobarhan, Majid

    2014-01-01

    Pancreatic Ductal Adenocarcinoma (PDAC) is among the most lethal solid tumors with grim prognosis. This dismal outcome can partially be explained by the resistance to currently available chemotherapy regimens or the failure of most anticancer agents, which prompted the development of new and effective therapeutic-approaches, such as inhibitors of the epidermal growth factor receptor (EGFR). Some of these EGFR inhibitors (e.g., erlotinib) are approved for lungcancer, however available data are inconclusive for treatment of pancreatic cancer patients with EGFR-targeted-therapies. Here we describe the critical role of EGFR pathway in pancreatic-cancer, strategies to enhance the effectiveness of EGFRinhibitors as well as the preclinical/clinical studies with particular emphasis on recent findings with monoclonal antibodies and tyrosine-inhibitors. Several combinations of EGFR inhibitors with other agents illustrate inhibition of tumor-induced angiogenesis and cell growth. Moreover, combination of erlotinib with gemcitabine showed statistically significance in overall-survival, compared to gemcitabine-alone. However high cost, little survival gain and increased risk of toxicities have limited its efficacy. Considering the multiple genetic mutations and the crosstalk of signaling pathways, (1) development of multiple targeted-therapies; (2) identification of predictive-biomarkers; and (3) those patients who are most likely benefit from therapy, could provide valuable direction for the clinical development of EGFR inhibitors. Moreover further preclinical/clinical studies are warranted to identify determinants of the activity of EGFR-inhibitors and mechanisms leading to resistance to EGFR inhibitors, through the analysis of genetic and environmental alterations affecting EGFR and parallel pro-cancer pathways. These studies will be critical to improve the efficacy and selectivity of current anticancer strategies targeting EGFR in pancreatic cancer.

  18. The complexity of targeting EGFR signalling in cancer: from expression to turnover.

    Science.gov (United States)

    Sebastian, Sinto; Settleman, Jeffrey; Reshkin, Stephan J; Azzariti, Amalia; Bellizzi, Antonia; Paradiso, Angelo

    2006-08-01

    The epidermal growth factor receptor (ErbB1 or EGFR) has been found to be altered in a variety of human cancers. A number of agents targeting these receptors, including specific antibodies directed against the ligand-binding domain of the receptor and small molecules that inhibit kinase activity are either in clinical trials or are already approved for clinical treatment. However, identifying patients that are likely to respond to such treatments has been challenging. As a consequence, it still remains important to identify additional alterations of the tumor cell that contribute to the response to EGFR-targeted agents. While EGFR-mediated signalling pathways have been well established, there is still a rather limited understanding of how intracellular protein-protein interactions, ubiquitination, endocytosis and subsequent degradation of EGFR contribute to the determination of sensitivity to EGFR targeting agents and are emerging areas of investigation. This review primarily focuses on the basic signal transduction pathways mediated through activated membrane bound and/or endosomal EGFR and emphasizes the need to co-target additional proteins that function either upstream or downstream of EGFR to improve cancer therapy.

  19. The pan-HER family tyrosine kinase inhibitor afatinib overcomes HER3 ligand heregulin-mediated resistance to EGFR inhibitors in non-small cell lung cancer

    Science.gov (United States)

    Yonesaka, Kimio; Kudo, Keita; Nishida, Satomi; Takahama, Takayuki; Iwasa, Tsutomu; Yoshida, Takeshi; Tanaka, Kaoru; Takeda, Masayuki; Kaneda, Hiroyasu; Okamoto, Isamu; Nishio, Kazuto; Nakagawa, Kazuhiko

    2015-01-01

    Afatinib is a second generation epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) characterized as an irreversible pan-human EGFR (HER) family inhibitor. Afatinib remains effective for a subpopulation of patients with non-small cell lung cancer (NSCLC) with acquired resistance to first generation EGFF-TKIs such as erlotinib. Heregulin activates HER3 in an autocrine fashion and causes erlotinib resistance in NSCLC. Here we examine whether afatinib is effective against heregulin-overexpressing NSCLCs harboring EGFR activating mutations. Afatinib but not erlotinib decreased EGFR mutant NSCLC PC9HRG cell proliferation in vitro and in mouse xenografts. Afatinib inhibited phosphorylation of the cell signaling pathway proteins HER3, EGFR, HER2, and HER4, likely by prevention of trans-phosphorylation as HER3 kinase activity is inadequate for auto-phosphorylation. Afatinib, unlike erlotinib, inhibited AKT activation, resulting in elevated apoptosis in PC9HRG cells. Clinically, a subpopulation of 33 patients with EGFR mutations and NSCLC who had received first generation EGFR-TKIs exhibited elevated plasma heregulin levels compared to healthy volunteers; one of these achieved a response with afatinib therapy despite having previously developed erlotinib resistance. Afatinib can overcome heregulin-mediated resistance to erlotinib in EGFR mutant NSCLC. Further studies are necessary to determine whether heregulin can predict afatinib efficacy after development offirst generation EGFR-TKI resistance. PMID:26418897

  20. Molecular modeling and description of a newly characterized activating mutation of the EGFR gene in non-small cell lung cancer

    Directory of Open Access Journals (Sweden)

    Otto Claudia

    2012-10-01

    Full Text Available Abstract Lung cancer is the leading cause of death among malignant diseases in humans worldwide. In the last decade development of new targeted drugs for the treatment of non-small cell lung cancer proved to be a promising approach to prolong the otherwise very poor prognosis of patients with advanced UICC stages. Epidermal growth factor receptor (EGFR has been in the focus of this lung cancer science and specific activating mutations are eligible for the treatment with specific tyrosine kinase inhibitors like gefitinib or erlotinib. Beside typical deletions in exon 19 and point mutations in exons 18 and 21 several insertions in exon 19 have been described and attributed activating properties as well. This is the first European and overall the 5th description in English literature of one of these specific insertions. To elucidate its structural changes leading to the activating properties we performed molecular modeling studies. These revealed conformational and electrostatic force field changes in the kinase domain of EGFR. To not miss uncommon mutations thorough and precise characterization of EGFR hotspots, i. e. at least exons 18, 19 and 21, should therefore be conducted to provide best medical care and to offer lung cancer patients appropriate cancer treatment. Virtual slides The vistual slides for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/2209889658102062

  1. Small tyrosine kinase inhibitors interrupt EGFR signaling by interacting with erbB3 and erbB4 in glioblastoma cell lines

    Energy Technology Data Exchange (ETDEWEB)

    Carrasco-Garcia, Estefania; Saceda, Miguel [Instituto de Biologia Molecular y Celular, Universidad Miguel Hernandez, 03202 Elche (Alicante) (Spain); Unidad de Investigacion, Hospital General Universitario de Elche, 03203 Elche (Alicante) (Spain); Grasso, Silvina; Rocamora-Reverte, Lourdes; Conde, Mariano; Gomez-Martinez, Angeles [Instituto de Biologia Molecular y Celular, Universidad Miguel Hernandez, 03202 Elche (Alicante) (Spain); Garcia-Morales, Pilar [Instituto de Biologia Molecular y Celular, Universidad Miguel Hernandez, 03202 Elche (Alicante) (Spain); Unidad de Investigacion, Hospital General Universitario de Elche, 03203 Elche (Alicante) (Spain); Ferragut, Jose A. [Instituto de Biologia Molecular y Celular, Universidad Miguel Hernandez, 03202 Elche (Alicante) (Spain); Martinez-Lacaci, Isabel, E-mail: imlacaci@umh.es [Instituto de Biologia Molecular y Celular, Universidad Miguel Hernandez, 03202 Elche (Alicante) (Spain); Unidad AECC de Investigacion Traslacional en Cancer, Hospital Universitario Virgen de la Arrixaca, 30120 Murcia (Spain)

    2011-06-10

    Signaling through the epidermal growth factor receptor (EGFR) is relevant in glioblastoma. We have determined the effects of the EGFR inhibitor AG1478 in glioblastoma cell lines and found that U87 and LN-229 cells were very sensitive to this drug, since their proliferation diminished and underwent a marked G{sub 1} arrest. T98 cells were a little more refractory to growth inhibition and A172 cells did not undergo a G{sub 1} arrest. This G{sub 1} arrest was associated with up-regulation of p27{sup kip1}, whose protein turnover was stabilized. EGFR autophosphorylation was blocked with AG1478 to the same extent in all the cell lines. Other small-molecule EGFR tyrosine kinase inhibitors employed in the clinic, such as gefitinib, erlotinib and lapatinib, were able to abrogate proliferation of glioblastoma cell lines, which underwent a G{sub 1} arrest. However, the EGFR monoclonal antibody, cetuximab had no effect on cell proliferation and consistently, had no effect on cell cycle either. Similarly, cetuximab did not inhibit proliferation of U87 {Delta}EGFR cells or primary glioblastoma cell cultures, whereas small-molecule EGFR inhibitors did. Activity of downstream signaling molecules of EGFR such as Akt and especially ERK1/2 was interrupted with EGFR tyrosine kinase inhibitors, whereas cetuximab treatment could not sustain this blockade over time. Small-molecule EGFR inhibitors were able to prevent phosphorylation of erbB3 and erbB4, whereas cetuximab only hindered EGFR phosphorylation, suggesting that EGFR tyrosine kinase inhibitors may mediate their anti-proliferative effects through other erbB family members. We can conclude that small-molecule EGFR inhibitors may be a therapeutic approach for the treatment of glioblastoma patients.

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

    Directory of Open Access Journals (Sweden)

    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.

  3. Epidermal growth factor receptor (EGFR) and EGFR mutations, function and possible role in clinical trials

    DEFF Research Database (Denmark)

    Voldborg, B R; Damstrup, L; Spang-Thomsen, M

    1997-01-01

    in the intracellular region of the receptor. This tyrosine kinase phosphorylates a number of intracellular substrates that activates pathways leading to cell growth, DNA synthesis and the expression of oncogenes such as fos and jun. EGFR is thought to be involved the development of cancer, as the EGFR gene is often...... amplified, and/or mutated in cancer cells. In this review we will focus on: (I) the structure and function of EGFR, (II) implications of receptor/ligand coexpression and EGFR mutations or overexpression, (III) its effect on cancer cells, (IV) the development of the malignant phenotype and (V) the clinical...

  4. C/EBPα Short-Activating RNA Suppresses Metastasis of Hepatocellular Carcinoma through Inhibiting EGFR/β-Catenin Signaling Mediated EMT.

    Directory of Open Access Journals (Sweden)

    Hongbo Huan

    Full Text Available Hepatocellular carcinoma is associated with high mortality, and tumor metastasis is an important reason for poor prognosis. However, metastasis has not been effectively prevented in clinical therapy and the mechanisms underlying metastasis have not been fully characterized. CCAAT/enhancer-binding protein-α (C/EBPα is a transcriptional regulator with an essential role in tumor metastasis. We used short-activating RNAs (saRNA to enhance expression of C/EBPα. Intravenous injection of C/EBPα-saRNA in a nude mouse liver orthotopic xenograft tumor model inhibited intrahepatic and distant metastasis. C/EBPα-saRNA-treated mice showed increased serum levels of albumin and decreased alanine aminotransferase (ALT, glutamic-oxalacetic transaminase (AST, indicating a role of C/EBPα in improving liver function. Migration and invasion were inhibited in hepatoma cell lines transfected with C/EBPα-saRNA. We also observed an inhibition of epithelial-mesenchymal transition (EMT and suppression of epidermal growth factor receptor (EGFR, EGFR phosphorylation, and β-catenin in C/EBPa-saRNA-transfected cells. Our results suggested that C/EBPα-saRNA successfully inhibited HCC metastasis by inhibiting EGFR/β-catenin signaling pathway mediated EMT in vitro and in vivo.

  5. Chronic inflammation enhances NGF-β/TrkA system expression via EGFR/MEK/ERK pathway activation in Sjögren's syndrome.

    Science.gov (United States)

    Lisi, Sabrina; Sisto, Margherita; Ribatti, Domenico; D'Amore, Massimo; De Lucro, Raffella; Frassanito, Maria Antonia; Lorusso, Loredana; Vacca, Angelo; Lofrumento, Dario Domenico

    2014-05-01

    Primary Sjögren's syndrome (pSS) is a chronic autoimmune exocrine disease associated with variable lymphocytic infiltration of the affected organs (primarily salivary and lachrymal glands). To investigate the potential implication of nerve growth factor-β (NGF-β) and its high affinity receptor tyrosine kinase receptor A (TrkA) in the regulation of pSS inflammatory responses, we studied their expression in the human salivary gland epithelial cells (SGEC) cultures from pSS minor salivary glands (MSG) biopsies and their relationship with histopathological disease parameters. Here, we demonstrated an increased expression of the NGF-β/TrkA system in pSS SGEC, correlated with the MSG inflammation grade. The results demonstrate that the pro-inflammatory cytokines TNF-α and IL-6 enhance NGF-β production; on the contrary, NGF-β production was reduced in the presence of both Raf-1 kinase and MEK inhibitors. Furthermore, TNF-α/IL-6 treatment increased ERK1/2 phosphorylation. Inhibition of the EGF/EGFR system also decreased NGF-β release by pSS SGEC, indicating that the chronic inflammatory condition characteristic of pSS enhances NGF-β production via EGFR/Raf-1/MEK/ERK pathway activation. NGF-β and TrkA expression is elevated in salivary gland epithelial cells of primary Sjögren's syndrome (pSS). Overexpression of NGF-β/TrkA system in pSS occurs via EGFR/Raf-1/MEK/ERK pathway. In pSS, NGF-β overexpression was prevented by EGFR/Raf-1/MEK/ERK pathway inhibition.

  6. Active G protein-coupled receptors (GPCR), matrix metalloproteinases 2/9 (MMP2/9), heparin-binding epidermal growth factor (hbEGF), epidermal growth factor receptor (EGFR), erbB2, and insulin-like growth factor 1 receptor (IGF-1R) are necessary for trenbolone acetate-induced alterations in protein turnover rate of fused bovine satellite cell cultures.

    Science.gov (United States)

    Thornton, K J; Kamanga-Sollo, E; White, M E; Dayton, W R

    2016-06-01

    Trenbolone acetate (TBA), a testosterone analog, increases protein synthesis and decreases protein degradation in fused bovine satellite cell (BSC) cultures. However, the mechanism through which TBA alters these processes remains unknown. Recent studies indicate that androgens improve rate and extent of muscle growth through a nongenomic mechanism involving G protein-coupled receptors (GPCR), matrix metalloproteinases (MMP), heparin-binding epidermal growth factor (hbEGF), the epidermal growth factor receptor (EGFR), erbB2, and the insulin-like growth factor-1 receptor (IGF-1R). We hypothesized that TBA activates GPCR, resulting in activation of MMP2/9 that releases hbEGF, which activates the EGFR and/or erbB2. To determine whether the proposed nongenomic pathway is involved in TBA-mediated alterations in protein turnover, fused BSC cultures were treated with TBA in the presence or absence of inhibitors for GPCR, MMP2/9, hbEGF, EGFR, erbB2, or IGF-1R, and resultant protein synthesis and degradation rates were analyzed. Assays were replicated at least 9 times for each inhibitor experiment utilizing BSC cultures obtained from at least 3 different steers that had no previous exposure to steroid compounds. As expected, fused BSC cultures treated with 10 n TBA exhibited increased ( GPCR, MMP2/9, hbEGF, EGFR, erbB2, or IGF-1R suppressed ( GPCR, MMP2/9, hbEGF, EGFR, erbB2, or IGF-1R in the presence of 10 n TBA each had no ( > 0.05) effect on TBA-mediated decreases in protein degradation. However, inhibition of both EGFR and erbB2 in the presence of 10 n TBA resulted in decreased ( GPCR, MMP2/9, hbEGF, EGFR, erbB2, and IGF-1R. However, the mechanism through which TBA mediates changes in protein degradation is different and appears to involve only the EGFR and erbB2. Furthermore, it appears the protein kinase B pathway is involved in TBA's effects on fused BSC cultures.

  7. Nuclear localization of epidermal growth factor receptor (EGFR) in ameloblastomas.

    Science.gov (United States)

    Pereira, Núbia Braga; do Carmo, Ana Carolina de Melo; Diniz, Marina Gonçalves; Gomez, Ricardo Santiago; Gomes, Dawidson Assis; Gomes, Carolina Cavalieri

    2015-01-01

    Ameloblastoma is a locally invasive neoplasm often associated with morbidity and facial deformities, showing increased Epidermal Growth Factor Receptor (EGFR) expression. Inhibition of EGFR was suggested as a treatment option for a subset of ameloblastomas. However, there are resistance mechanisms that impair anti-EGFR therapies. One important resistance mechanism for EGFR-inhibition is the EGFR nuclear localization, which activates genes responsible for its mitogenic effects, such as Cyclin D1. We assessed EGFR nuclear localization in encapsulated (unicystic, n = 3) and infiltrative (multicystic, n = 11) ameloblastomas and its colocalization with Cyclin D1 by using anti-EGFR and anti-lamin B1 double labeling immunofluorescence analyzed by confocal microscopy. Oral inflammatory fibrous hyperplasia and oral squamous cell carcinoma samples were used for comparison. Twelve cases of ameloblastoma exhibited nuclear EGFR colocalization with lamin B1. This positive staining was mainly observed in the ameloblast-like cells. The EGFR nuclear localization was also observed in control samples. In addition, nuclear EGFR colocalized with Cyclin D1 in ameloblastomas. Nuclear EGFR occurs in ameloblastomas in association with Cyclin D1 expression, which is important in terms of tumor biology clarification and raises a concern about anti-EGFR treatment resistance in ameloblastomas.

  8. Coexpression of receptor tyrosine kinase AXL and EGFR in human primary lung adenocarcinomas.

    Science.gov (United States)

    Wu, Zhenzhou; Bai, Fan; Fan, Liyun; Pang, Wenshuai; Han, Ruiyu; Wang, Juan; Liu, Yueping; Yan, Xia; Duan, Huijun; Xing, Lingxiao

    2015-12-01

    AXL has been identified as a tyrosine kinase switch that causes resistance to inhibitors targeting epidermal growth factor receptor (EGFR) signaling in non-small cell lung cancer (NSCLC). However, the relationship between 2 receptor tyrosine kinases, AXL and EGFR, and the relevance of AXL expression with EGFR mutation status in treatment-naive human NSCLCs remain uncertain. In this study, we evaluated the coexpression pattern of AXL, EGFR, and pEGFR(1068) in 109 lung adenocarcinoma patients with or without an EGFR mutation. There were 68 (62.4%) patients with tumors harboring EGFR mutations such as 19 del and/or L858R; 2 patients were T790M positive. The expression of AXL, EGFR, and pEGFR(1068) was detected in 60 (55%), 68 (62.4%), and 57 (52.3%) of 109 patients, respectively. The positive rates of EGFR and pEGFR(1068) were associated with the L858R mutation alone or with the 19 del and L858R mutation status. Further analysis indicated that the percentage of AXL(+)/EGFR(+)/pEGFR(1068) coexpression in 68 EGFR-activating mutations patients was significantly higher than that in 39 EGFR wild-type patients (30.9% versus 10.3%, P=.015). Furthermore, in the subgroup of AXL(+) patients (35 mutation(+) and 23 wild-type patients), the coexpression rates of AXL(+)/pEGFR(1068+) and AXL(+)/EGFR(+)/pEGFR(1068+) in patients with EGFR mutations were significantly higher compared with those in wild-type patients (both P<.05). Our study emphasized that the AXL and EGFR receptor tyrosine kinases were coexpressed in a subgroup of treatment-naive lung adenocarcinomas with or without EGFR mutations. Anti-AXL therapeutics delivered up front in combination with an EGFR inhibitor might prevent or delay resistance in patients with AXL-positive, EGFR-mutant, or wild-type NSCLC. Copyright © 2015 Elsevier Inc. All rights reserved.

  9. 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...

  10. 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...

  11. Brigatinib combined with anti-EGFR antibody overcomes osimertinib resistance in EGFR-mutated non-small-cell lung cancer

    Science.gov (United States)

    Uchibori, Ken; Inase, Naohiko; Araki, Mitsugu; Kamada, Mayumi; Sato, Shigeo; Okuno, Yasushi; Fujita, Naoya; Katayama, Ryohei

    2017-03-01

    Osimertinib has been demonstrated to overcome the epidermal growth factor receptor (EGFR)-T790M, the most relevant acquired resistance to first-generation EGFR-tyrosine kinase inhibitors (EGFR-TKIs). However, the C797S mutation, which impairs the covalent binding between the cysteine residue at position 797 of EGFR and osimertinib, induces resistance to osimertinib. Currently, there are no effective therapeutic strategies to overcome the C797S/T790M/activating-mutation (triple-mutation)-mediated EGFR-TKI resistance. In the present study, we identify brigatinib to be effective against triple-mutation-harbouring cells in vitro and in vivo. Our original computational simulation demonstrates that brigatinib fits into the ATP-binding pocket of triple-mutant EGFR. The structure-activity relationship analysis reveals the key component in brigatinib to inhibit the triple-mutant EGFR. The efficacy of brigatinib is enhanced markedly by combination with anti-EGFR antibody because of the decrease of surface and total EGFR expression. Thus, the combination therapy of brigatinib with anti-EGFR antibody is a powerful candidate to overcome triple-mutant EGFR.

  12. Including total EGFR staining in scoring improves EGFR mutations detection by mutation-specific antibodies and EGFR TKIs response prediction.

    Directory of Open Access Journals (Sweden)

    Shang-Gin Wu

    Full Text Available Epidermal growth factor receptor (EGFR is a novel target for therapy in subsets of non-small cell lung cancer, especially adenocarcinoma. Tumors with EGFR mutations showed good response to EGFR tyrosine kinase inhibitors (TKIs. We aimed to identify the discriminating capacity of immunohistochemical (IHC scoring to detect L858R and E746-A750 deletion mutation in lung adenocarcinoma patients and predict EGFR TKIs response. Patients with surgically resected lung adenocarcinoma were enrolled. EGFR mutation status was genotyped by PCR and direct sequencing. Mutation-specific antibodies for L858R and E746-A750 deletion were used for IHC staining. Receiver operating characteristic (ROC curves were used to determine the capacity of IHC, including intensity and/or quickscore (Q score, in differentiating L858R and E746-A750 deletion. We enrolled 143 patients during September 2000 to May 2009. Logistic-regression-model-based scoring containing both L858R Q score and total EGFR expression Q score was able to obtain a maximal area under the curve (AUC: 0.891 to differentiate the patients with L858R. Predictive model based on IHC Q score of E746-A750 deletion and IHC intensity of total EGFR expression reached an AUC of 0.969. The predictive model of L858R had a significantly higher AUC than L858R intensity only (p = 0.036. Of the six patients harboring complex EGFR mutations with classical mutation patterns, five had positive IHC staining. For EGFR TKI treated cancer recurrence patients, those with positive mutation-specific antibody IHC staining had better EGFR TKI response (p = 0.008 and longer progression-free survival (p = 0.012 than those without. In conclusion, total EGFR expression should be included in the IHC interpretation of L858R. After adjusting for total EGFR expression, the scoring method decreased the false positive rate and increased diagnostic power. According to the scoring method, the IHC method is useful to predict the

  13. A high expression EGFR/cell membrane chromatography and online high performance liquid chromatography/mass spectrometry method for screening EGFR antagonists from Rhizoma Polygoni Cuspidati

    Directory of Open Access Journals (Sweden)

    Meng Sun

    2011-08-01

    Full Text Available The epidermal growth factor receptors (EGFRs in some tumor cells are significant targets for drug discovery. In this work, we have developed an EGFR cell membrane chromatography and online high performance liquid chromatography/mass spectrometry system for screening active component from Rhizoma Polygoni Cuspidati. As a result, resveratrol from Rhizoma Polygoni Cuspidati was found to be the active component acting on EGFR like gefitinib. There was a good relationship between their inhibiting effects on EGFR secretion and HEK293 EGFR cell growth in vitro. The EGFR/CMC-online-HPLC/MS system demonstrated fast and effective characteristics for screening leading compounds from traditional Chinese medicine.

  14. Monitoring of Circulating Tumor Cells and Their Expression of EGFR/Phospho-EGFR During Combined Radiotherapy Regimens in Locally Advanced Squamous Cell Carcinoma of the Head and Neck

    Energy Technology Data Exchange (ETDEWEB)

    Tinhofer, Ingeborg, E-mail: ingeborg.tinhofer@charite.de [Translational Radiooncology Laboratory, Department of Radiooncology and Radiotherapy, Charite Campus Mitte, Charite Universitaetsmedizin Berlin, Berlin (Germany); Hristozova, Tsvetana; Stromberger, Carmen [Translational Radiooncology Laboratory, Department of Radiooncology and Radiotherapy, Charite Campus Mitte, Charite Universitaetsmedizin Berlin, Berlin (Germany); KeilhoIz, Ulrich [Department of Hematology and Oncology, Campus Benjamin Franklin, Charite Universitaetsmedizin Berlin, Berlin (Germany); Budach, Volker [Translational Radiooncology Laboratory, Department of Radiooncology and Radiotherapy, Charite Campus Mitte, Charite Universitaetsmedizin Berlin, Berlin (Germany)

    2012-08-01

    Purpose: The numbers of circulating tumor cells (CTCs) and their expression/activation of epidermal growth factor receptor (EGFR) during the course of combined chemo- or bioradiotherapy regimens as potential biomarkers of treatment efficacy in squamous cell carcinoma of the head and neck (SCCHN) were determined. Methods and Materials: Peripheral blood samples from SCCHN patients with locally advanced stage IVA/B disease who were treated with concurrent radiochemotherapy or induction chemotherapy followed by bioradiation with cetuximab were included in this study. Using flow cytometry, the absolute number of CTCs per defined blood volume as well as their expression of EGFR and its phosphorylated form (pEGFR) during the course of treatment were assessed. Results: Before treatment, we detected {>=}1 CTC per 3.75 mL blood in 9 of 31 patients (29%). Basal expression of EGFR was detected in 100% and pEGFR in 55% of the CTC+ cases. The frequency of CTC detection was not influenced by induction chemotherapy. However, the number of CTC+ samples significantly increased after radiotherapy. This radiation-induced increase in CTC numbers was less pronounced when radiotherapy was combined with cetuximab compared to its combination with cisplatin/5-fluorouracil. The former treatment regimen was also more effective in reducing pEGFR expression in CTCs. Conclusions: Definitive radiotherapy regimens of locally advanced SCCHN can increase the number of CTCs and might thus contribute to a systemic spread of tumor cells. Further studies are needed to evaluate the predictive value of the radiation-induced increase in CTC numbers and the persistent activation of the EGFR signalling pathway in individual CTC+ cases.

  15. Bufalin Reverses HGF-Induced Resistance to EGFR-TKIs in EGFR Mutant Lung Cancer Cells via Blockage of Met/PI3k/Akt Pathway and Induction of Apoptosis

    Directory of Open Access Journals (Sweden)

    Xiao-Hong Kang

    2013-01-01

    Full Text Available The epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs, such as gefitinib and erlotinib, have shown promising therapeutic efficacy in nonsmall cell lung cancer (NSCLC patients harboring epidermal growth factor receptor- (EGFR- activating mutation. However, the inevitable recurrence resulting from acquired resistance has limited the clinical improvement in therapy outcomes. Many studies demonstrate that hepatocyte growth factor- (HGF- Met axis plays an important role in tumor progression and drug sensitivity. HGF may induce resistance to EGFR-TKIs in EGFR mutant lung cancer cells by Met/PI3K/Akt signaling. The purpose of this study was to determine whether bufalin, a major bioactive component of Venenum Bufonis, could reverse HGF-induced resistance to reversible and irreversible EGFR-TKIs in mutant lung cancer cells PC-9, HCC827, and H1975. Our studies showed that bufalin could reverse resistance to reversible and irreversible EGFR-TKIs induced by exogenous HGF in EGFR mutant lung cancer cells by inhibiting the Met/PI3K/Akt pathway and inducing death signaling. These results suggested that bufalin might have a potential to overcome HGF-induced resistance to molecular-targeted drugs for lung cancer.

  16. Niacin Activates the PI3K/Akt Cascade via PKC- and EGFR-Transactivation-Dependent Pathways through Hydroxyl-Carboxylic Acid Receptor 2

    Science.gov (United States)

    Zhang, Wenjuan; Zhou, Qi; Yu, Yena; Shi, Ying; Offermanns, Stefan; Lu, Jianxin; Zhou, Naiming

    2014-01-01

    Niacin has been demonstrated to activate a PI3K/Akt signaling cascade to prevent brain damage after stroke and UV-induced skin damage; however, the underlying molecular mechanisms for HCA2-induced Akt activation remain to be elucidated. Using CHO-K1 cells stably expressing HCA2 and A431 cells, a human epidermoid cell line with high levels of endogenous expression of functional HCA2 receptors, we first demonstrated that niacin induced a robust Akt phosphorylation at both Thr308 and Ser473 in a time-dependent fashion, with a maximal activation at 5 min and a subsequent reduction to baseline by 30 min through HCA2, and that the activation was significantly blocked by pertussis toxin. The HCA2-mediated activation of Akt was also significantly inhibited by the PKC inhibitors GF109203x and Go6983 in both cell lines, by the PDGFR-selective inhibitor tyrphostin A9 in CHO-HCA2 cells and by the MMP inhibitor GM6001 and EGFR-specific inhibitor AG1478 in A431 cells. These results suggest that the PKC pathway and PDGFR/EGFR transactivation pathway play important roles in HCA2-mediated Akt activation. Further investigation indicated that PI3K and the Gβγ subunit were likely to play an essential role in HCA2-induced Akt activation. Moreover, Immunobloting analyses using an antibody that recognizes p70S6K1 phosphorylated at Thr389 showed that niacin evoked p70S6K1 activation via the PI3K/Akt pathway. The results of our study provide new insight into the signaling pathways involved in HCA2 activation. PMID:25375133

  17. Niacin activates the PI3K/Akt cascade via PKC- and EGFR-transactivation-dependent pathways through hydroxyl-carboxylic acid receptor 2.

    Directory of Open Access Journals (Sweden)

    Huawang Sun

    Full Text Available Niacin has been demonstrated to activate a PI3K/Akt signaling cascade to prevent brain damage after stroke and UV-induced skin damage; however, the underlying molecular mechanisms for HCA2-induced Akt activation remain to be elucidated. Using CHO-K1 cells stably expressing HCA2 and A431 cells, a human epidermoid cell line with high levels of endogenous expression of functional HCA2 receptors, we first demonstrated that niacin induced a robust Akt phosphorylation at both Thr308 and Ser473 in a time-dependent fashion, with a maximal activation at 5 min and a subsequent reduction to baseline by 30 min through HCA2, and that the activation was significantly blocked by pertussis toxin. The HCA2-mediated activation of Akt was also significantly inhibited by the PKC inhibitors GF109203x and Go6983 in both cell lines, by the PDGFR-selective inhibitor tyrphostin A9 in CHO-HCA2 cells and by the MMP inhibitor GM6001 and EGFR-specific inhibitor AG1478 in A431 cells. These results suggest that the PKC pathway and PDGFR/EGFR transactivation pathway play important roles in HCA2-mediated Akt activation. Further investigation indicated that PI3K and the Gβγ subunit were likely to play an essential role in HCA2-induced Akt activation. Moreover, Immunobloting analyses using an antibody that recognizes p70S6K1 phosphorylated at Thr389 showed that niacin evoked p70S6K1 activation via the PI3K/Akt pathway. The results of our study provide new insight into the signaling pathways involved in HCA2 activation.

  18. EGFR transactivation: mechanisms, pathophysiology and potential therapies in cardiovascular system

    Science.gov (United States)

    Forrester, Steven J.; Kawai, Tatsuo; Elliott, Katherine J.; O’Brien, Shannon; Thomas, Walter; Harris, Raymond C.; Eguchi, Satoru

    2017-01-01

    Accumulating studies suggest that the epidermal growth factor receptor (EGFR) activation is associated with the physiology and pathophysiology of the cardiovascular system, and inhibition of EGFR activity is emerging as a potential therapeutic strategy to treat diseases, including hypertension, cardiac hypertrophy, renal fibrosis and abdominal aortic aneurysm. The capacity of G protein-coupled receptor (GPCR) agonists, such as angiotensin II (AngII), to promote EGFR signaling is well described – a process termed EGFR “transactivation” – yet delineating the molecular processes and functional relevance of this crosstalk has been challenging. Moreover, these critical findings are dispersed among many different fields. The aim of our review is to highlight the recent advancement of the signaling cascades and downstream consequences of EGFR transactivation within the cardiovascular renal system in vitro and in vivo. We will also focus on linking EGFR transactivation to animal models of the disease as well as the potential therapeutic applications. PMID:26566153

  19. EGFR induces expression of IRF-1 via STAT1 and STAT3 activation leading to growth arrest of human cancer cells

    DEFF Research Database (Denmark)

    Andersen, Peter; Pedersen, Mikkel Wandahl; Woetmann, Anders

    2008-01-01

    the constitutively active cancer specific receptor EGFRvIII are unable to mediate phosphorylation of these STATs and thereby incapable of inducing IRF-1. We also demonstrate that IRF-1 is expressed in an EGF dose-dependent manner, which correlates with inhibition of cell proliferation, and that the regulation of IRF......-1 is partially dependent on intracellular Src family kinase activity. Treatment with the dual specific Abl/c-Src kinase inhibitor AZD0530 significantly reduces the growth inhibitory effect of high EGF concentrations, signifying that EGFR induced IRF-1 is responsible for the observed growth...... products mediate growth arrest and activate immune effector cells, and which potentially could be involved in alerting the immune system in vivo leading to elimination of the transformed cells....

  20. The E3 ubiquitin ligase NEDD4 mediates cell migration signaling of EGFR in lung cancer cells.

    Science.gov (United States)

    Shao, Genbao; Wang, Ranran; Sun, Aiqin; Wei, Jing; Peng, Ke; Dai, Qian; Yang, Wannian; Lin, Qiong

    2018-02-19

    EGFR-dependent cell migration plays an important role in lung cancer progression. Our previous study observed that the HECT E3 ubiquitin ligase NEDD4 is significantly correlated with tumor metastasis and required for migration and invasion signaling of EGFR in gastric cancer cells. However, how NEDD4 promotes the EGFR-dependent lung cancer cell migration is unknown. This study is to elucidate the mechanism by which NEDD4 mediates the EGFR lung cancer migration signaling. Lentiviral vector-loaded NEDD4 shRNA was used to deplete endogenous NEDD4 in lung cancer cell lines. Effects of the NEDD4 knockdown on the EGFR-dependent or independent lung cancer cell migration were determined using the wound-healing and transwell assays. Association of NEDD4 with activated EGFR was assayed by co-immunoprecipitation. Co-expression of NEDD4 with EGFR or PTEN was determined by immunohistochemical (IHC) staining in 63 lung adenocarcinoma tissue samples. Effects of NEDD4 ectopic expression or knockdown on PTEN ubiquitination and down-regulation, AKT activation and lysosomal secretion were examined using the GST-Uba pulldown assay, immunoblotting, immunofluorescent staining and a human cathepsin B ELISA assay respectively. The specific cathepsin B inhibitor CA-074Me was used for assessing the role of cathepsin B in lung cancer cell migration. Knockdown of NEDD4 significantly reduced EGF-stimulated cell migration in non-small cell lung carcinoma (NSCLC) cells. Co-immunoprecipitation assay found that NEDD4 is associated with EGFR complex upon EGF stimulation, and IHC staining indicates that NEDD4 is co-expressed with EGFR in lung adenocarcinoma tumor tissues, suggesting that NEDD4 might mediate lung cancer cell migration by interaction with the EGFR signaling complex. Interestingly, NEDD4 promotes the EGF-induced cathepsin B secretion, possibly through lysosomal exocytosis, as overexpression of the ligase-dead mutant of NEDD4 impedes lysosomal secretion, and knockdown of NEDD4

  1. Bioinformatics-driven discovery of rational combination for overcoming EGFR-mutant lung cancer resistance to EGFR therapy

    Science.gov (United States)

    Kim, Jihye; Vasu, Vihas T.; Mishra, Rangnath; Singleton, Katherine R.; Yoo, Minjae; Leach, Sonia M.; Farias-Hesson, Eveline; Mason, Robert J.; Kang, Jaewoo; Ramamoorthy, Preveen; Kern, Jeffrey A.; Heasley, Lynn E.; Finigan, James H.; Tan, Aik Choon

    2014-01-01

    Motivation: Non–small-cell lung cancer (NSCLC) is the leading cause of cancer death in the United States. Targeted tyrosine kinase inhibitors (TKIs) directed against the epidermal growth factor receptor (EGFR) have been widely and successfully used in treating NSCLC patients with activating EGFR mutations. Unfortunately, the duration of response is short-lived, and all patients eventually relapse by acquiring resistance mechanisms. Result: We performed an integrative systems biology approach to determine essential kinases that drive EGFR-TKI resistance in cancer cell lines. We used a series of bioinformatics methods to analyze and integrate the functional genetics screen and RNA-seq data to identify a set of kinases that are critical in survival and proliferation in these TKI-resistant lines. By connecting the essential kinases to compounds using a novel kinase connectivity map (K-Map), we identified and validated bosutinib as an effective compound that could inhibit proliferation and induce apoptosis in TKI-resistant lines. A rational combination of bosutinib and gefitinib showed additive and synergistic effects in cancer cell lines resistant to EGFR TKI alone. Conclusions: We have demonstrated a bioinformatics-driven discovery roadmap for drug repurposing and development in overcoming resistance in EGFR-mutant NSCLC, which could be generalized to other cancer types in the era of personalized medicine. Availability and implementation: K-Map can be accessible at: http://tanlab.ucdenver.edu/kMap. Contact: aikchoon.tan@ucdenver.edu or finiganj@njhealth.org Supplementary information: Supplementary data are available at Bioinformatics online. PMID:24812339

  2. Model-Based Analysis of HER Activation in Cells Co-Expressing EGFR, HER2 and HER3

    OpenAIRE

    Harish Shankaran; Yi Zhang; Yunbing Tan; Haluk Resat

    2013-01-01

    The HER/ErbB family of receptor tyrosine kinases drives critical responses in normal physiology and cancer, and the expression levels of the various HER receptors are critical determinants of clinical outcomes. HER activation is driven by the formation of various dimer complexes between members of this receptor family. The HER dimer types can have differential effects on downstream signaling and phenotypic outcomes. We constructed an integrated mathematical model of HER activation, and traffi...

  3. Antagonizing c-Cbl enhances EGFR-dependent corneal epithelial homeostasis.

    Science.gov (United States)

    Rush, Jamie S; Boeving, Michael A; Berry, William L; Ceresa, Brian P

    2014-07-01

    In many cell types, the E3 ubiquitin ligase, c-Cbl, induces ligand-dependent ubiquitylation of the epidermal growth factor receptor (EGFR) and targets the receptor for lysosomal degradation. The goal of this study was to determine whether c-Cbl is a negative regulator of EGFR in the corneal epithelium and if it can be inhibited to promote corneal epithelial homeostasis. Expression and activity of c-Cbl were blocked in immortalized human corneal epithelial cells (hTCEpi) using RNAi and pharmacological agents ([4-amino-5-(4-methylphenyl)-7-(t-butyl)pyrazolo-d-3,4-pyrimidine] or PP1). Following c-Cbl inhibition, cells were assessed for ligand-dependent receptor ubiquitylation, receptor phosphorylation, and in vitro wound healing. Subsequent experiments used PP1 in hTCEpi cells and monitored in vivo murine corneal epithelial wound healing. Knockdown and inhibition of c-Cbl decreased ligand-dependent ubiquitylation of the EGFR and prolonged receptor activity as measured by tyrosine phosphorylation. Further, these treatments also increased the extent of ligand-dependent corneal epithelial wound healing in vitro and in vivo. Manipulating the duration of EGFR activity can enhance the rate of restoration of the corneal epithelial layer. Based on our findings, c-Cbl is a new therapeutic target to enhance EGFR-mediated corneal epithelial homeostasis that bypasses the limitations of previous approaches. Copyright 2014 The Association for Research in Vision and Ophthalmology, Inc.

  4. Silica nanoparticles induce cytokine responses in lung epithelial cells through activation of a p38/TACE/TGF-α/EGFR-pathway and NF-κΒ signalling

    Energy Technology Data Exchange (ETDEWEB)

    Skuland, Tonje, E-mail: tonje.skuland@fhi.no; Øvrevik, Johan; Låg, Marit; Schwarze, Per; Refsnes, Magne

    2014-08-15

    Amorphous silica nanoparticles (SiNPs) have previously been shown to induce marked cytokine (interleukin-6; IL-6 and interleukin-8; CXCL8/IL-8) responses independently of particle uptake in human bronchial epithelial BEAS-2B cells. In this study the involvement of the mitogen-activated protein kinases (MAP-kinases), nuclear factor-kappa Β (NF-κΒ) and in particular tumour necrosis factor-α converting enzyme (TACE) and—epidermal growth factor receptor (EGFR) signalling pathways were examined in triggering of IL-6 and CXCL8 release after exposure to a 50 nm silica nanoparticle (Si50). Exposure to Si50 increased phosphorylation of NF-κΒ p65 and MAP-kinases p38 and JUN-N-terminal protein kinase pathways (JNK), but not extracellular signal regulated kinases (ERK). Inhibition of NF-κΒ and p38 reduced the cytokine responses to Si50, whereas neither JNK- nor ERK-inhibition exerted any significant effect on the responses to Si50. Increases in membrane-bound transforming growth factor-α (TGF-α) release and EGFR phosphorylation were also observed after Si50 exposure, and pre-treatment with inhibitors of these pathways reduced the release of IL-6 and CXCL8, but did not affect the Si50-induced phosphorylation of p38 and p65. In contrast, p38-inhibition partially reduced Si50-induced TGF-α release, while the p65-inhibition was without effect. Overall, our results indicate that Si50-induced IL-6 and CXCL8 responses in BEAS-2B cells were regulated through combined activation of several pathways, including NF-κΒ and p38/TACE/TGF-α/EGFR signalling. The study identifies critical, initial events in the triggering of pro-inflammatory responses by nanoparticles. - Highlights: • Silica nanoparticles induce IL-6 and CXCL8 via NFκB and MAPKinase p38 in BEAS-2B • Silica nanoparticles induce release of the EGF-receptor ligand TGF-α • TGF-α release contributes to the IL-6 and CXCL8 release • Phosphorylation of p38 is involved in release of TGF-α.

  5. eGFR

    Science.gov (United States)

    ... Pregnancy hCG Tumor Marker HDL Cholesterol Heavy Metals Helicobacter pylori Testing Hematocrit Hemoglobin Hemoglobin A1c Hemoglobinopathy Evaluation ... Foundation for calculating eGFR in adults Modification of Diet in Renal Disease Study (MDRD) equation—some laboratories ...

  6. Sulfated Galactans from Red Seaweed Gracilaria fisheri Target EGFR and Inhibit Cholangiocarcinoma Cell Proliferation.

    Science.gov (United States)

    Sae-Lao, Thannicha; Tohtong, Rutaiwan; Bates, David O; Wongprasert, Kanokpan

    2017-01-01

    Cholangiocarcinoma (CCA) is increasing in incidence worldwide and is resistant to chemotherapeutic agents, making treatment of CCA a major challenge. Previous studies reported that natural sulfated polysaccharides (SPs) disrupted growth factor receptor activation in cancer cells. The present study, therefore, aimed at investigating the antiproliferation effect of sulfated galactans (SG) isolated from the red seaweed Gracilaria fisheri (G. fisheri) on CCA cell lines. Direct binding activity of SG to CCA cells, epidermal growth factor (EGF) and epidermal growth factor receptor (EGFR) were determined. The effect of SG on proliferation of CCA cells was investigated. Cell cycle analyses and expression of signaling molecules associated with proliferation were also determined. The results demonstrated that SG bound directly to EGFR. SG inhibited proliferation of various CCA cell lines by inhibiting EGFR and extracellular signal-regulated kinases (ERK) phosphorylation, and inhibited EGF-induced increased cell proliferation. Cell cycle analyses showed that SG induced cell cycle arrest at the G0/G1 phase, down-regulated cell cycle genes and proteins (cyclin-D, cyclin-E, cdk-4, cdk-2), and up-regulated the tumor suppressor protein P53 and the cyclin-dependent kinase inhibitor P21. Taken together, these data demonstrate that SG from G. fisheri inhibited proliferation of CCA cells, and its mechanism of inhibition is mediated, to some extent, by inhibitory effects on EGFR activation and EGFR/ERK signaling pathway. SG presents a potential EGFR targeted molecule, which may be further clinically developed in a combination therapy for CCA treatment.

  7. EGFR/HER2 inhibitors effectively reduce the malignant potential of MDR breast cancer evoked by P-gp substrates in vitro and in vivo.

    Science.gov (United States)

    Jin, Yiting; Zhang, Wei; Wang, Hongying; Zhang, Zijing; Chu, Chengyu; Liu, Xiuping; Zou, Qiang

    2016-02-01

    Multidrug resistance (MDR) induced by chemotherapy in breast cancer frequently leads to tumor invasion, metastasis and poor clinical outcome. We preliminarily found that the epidermal growth factor receptor (EGFR) is involved in enhancing the malignant potential of MDR breast cancer cells, but the mechanism remains unclear. In the present study, we demonstrated in vitro and in vivo that EGFR/HER2 promote the invasive and metastatic abilities of MDR breast cancer. More importantly, a new function of EGFR/HER2 inhibitors was revealed for the first time, which could improve the treatment efficacy of breast cancer by reversing the MDR process rather than by inhibiting tumor growth. Firstly, using quantitative real‑time PCR and western blot analysis, we found that overexpression of EGFR/HER2 in MCF7/Adr cells upregulated CD147 and MMP2/9 at both the transcription and protein expression levels, which promoted tumor cell migration, as determined using an in vitro invasion assay. Secondly, the upregulated levels of CD147 and MMP2/9 were decreased when EGFR/HER2 activity was inhibited, and therefore tumor invasion was also significantly inhibited. These phenomena were also demonstrated in nude mouse assays. Additionally, in MDR breast cancer patients, we found that overexpression of EGFR and P‑gp levels led to shorter overall survival (OS) and disease‑free survival (DFS) by IHC assays and Kaplan‑Meier survival analysis. In conclusion, EGFR/HER2 play a crucial role in enhancing CD147 and MMP expression to establish favorable conditions for invasion/metastasis in MDR breast cancer. The scope of application of EGFR/HER2 inhibitors may be expanded in EGFR/HER2‑positive patients. We suggest that MDR breast cancer patients may benefit from novel therapies targeting EGFR/HER2.

  8. Aspirin Prevents Colorectal Cancer by Normalizing EGFR Expression.

    Science.gov (United States)

    Li, Haitao; Zhu, Feng; Boardman, Lisa A; Wang, Lei; Oi, Naomi; Liu, Kangdong; Li, Xiang; Fu, Yang; Limburg, Paul J; Bode, Ann M; Dong, Zigang

    2015-05-01

    Aspirin intake reduces the risk of colorectal cancer (CRC), but the molecular underpinnings remain elusive. Epidermal growth factor receptor (EGFR), which is overexpressed in about 80% of CRC cases, is implicated in the etiology of CRC. Here, we investigated whether aspirin can prevent CRC by normalizing EGFR expression. Immunohistochemistry staining was performed on paraffin-embedded tissue sections from normal colon mucosa, adenomatous polyps from FAP patients who were classified as regular aspirin users or nonusers. The interplay between cyclooxygenase-2 (COX-2) and EGFR was studied in primary intestinal epithelial cells isolated from Apc(Min) mice, immortalized normal human colon epithelial cells (HCEC) as well as murine embryonic fibroblasts (MEFs). Immunohistochemistry staining results established that EGFR overexpression is an early event in colorectal tumorigenesis, which can be greatly attenuated by regular use of aspirin. Importantly, EGFR and COX-2 were co-overexpressed and co-localized with each other in FAP patients. Further mechanistic studies revealed that COX-2 overexpression triggers the activation of the c-Jun-dependent transcription factor, activator protein-1 (AP-1), which binds to the Egfr promoter. Binding facilitates the cellular accumulation of EGFR and lowers the threshold required for pre-neoplastic cells to undergo transformation. Aspirin might exert its chemopreventive activity against CRC, at least partially, by normalizing EGFR expression in gastrointestinal precancerous lesions.

  9. High EGFR_1 Inside-Out Activated Inflammation-Induced Motility through SLC2A1-CCNB2-HMMR-KIF11-NUSAP1-PRC1-UBE2C.

    Science.gov (United States)

    Zhou, Huilei; Wang, Lin; Huang, Juxiang; Jiang, Minghu; Zhang, Xiaoyu; Zhang, Liyuan; Wang, Yangming; Jiang, Zhenfu; Zhang, Zhongjie

    2015-01-01

    48 different Pearson mutual-positive-correlation epidermal growth factor receptor (EGFR_1)-activatory molecular feedback, up- and down-stream network was constructed from 171 overlapping of 366 GRNInfer and 223 Pearson under EGFR_1 CC ≥0.25 in high lung adenocarcinoma compared with low human normal adjacent tissues. Our identified EGFR_1 inside-out upstream activated molecular network showed SLC2A1 (solute carrier family 2 (facilitated glucose transporter) member 1), CCNB2 (cyclin B2), HMMR (hyaluronan-mediated motility receptor (RHAMM)), KIF11 (kinesin family member 11), NUSAP1 (nucleolar and spindle associated protein 1), PRC1 (protein regulator of cytokinesis 1), UBE2C (ubiquitin-conjugating enzyme E2C) in high lung adenocarcinoma. EGFR_1 inside-out upstream activated terms network includes intracellular, membrane fraction, cytoplasm, plasma membrane, integral to membrane, basolateral plasma membrane, transmembrane transport, nucleus, cytosol, cell surface; T cell homeostasis, inflammation; microtubule cytoskeleton, embryonic development (sensu Mammalia), cell cycle, mitosis, thymus development, cell division, regulation of cell cycle, Contributed--cellular process--Hs cell cycle KEGG, cytokinesis, M phase, M phase of mitotic cell cycle, estrogen-responsive protein Efp controls cell cycle and breast tumors growth, cell motility, locomotion, locomotory behavior, neoplasm metastasis, spindle pole, spindle microtubule, microtubule motor activity, microtubule-based movement, mitotic spindle organization and biogenesis, mitotic centrosome separation, spindle pole body organization and biogenesis, microtubule-based process, microtubule, cytokinesis after mitosis, mitotic chromosome condensation, establishment of mitotic spindle localization, positive regulation of mitosis, mitotic spindle elongation, spindle organization and biogenesis, positive regulation of exit from mitosis, regulation of cell proliferation, positive regulation of cell proliferation based on

  10. XGFR*, a novel affinity-matured bispecific antibody targeting IGF-1R and EGFR with combined signaling inhibition and enhanced immune activation for the treatment of pancreatic cancer

    Science.gov (United States)

    Schanzer, Juergen M.; Wartha, Katharina; Moessner, Ekkehard; Hosse, Ralf J.; Moser, Samuel; Croasdale, Rebecca; Trochanowska, Halina; Shao, Cuiying; Wang, Peng; Shi, Lei; Weinzierl, Tina; Rieder, Natascha; Bacac, Marina; Ries, Carola H.; Kettenberger, Hubert; Schlothauer, Tilman; Friess, Thomas; Umana, Pablo; Klein, Christian

    2016-01-01

    ABSTRACT The epidermal growth factor receptor (EGFR) and the insulin-like growth factor-1 receptor (IGF-1R) play critical roles in tumor growth, providing a strong rationale for the combined inhibition of IGF-1R and EGFR signaling in cancer therapy. We describe the design, affinity maturation, in vitro and in vivo characterization of the bispecific anti-IGF-1R/EGFR antibody XGFR*. XGFR* is based on the bispecific IgG antibody XGFR, which enabled heterodimerization of an IGF-1R binding scFab heavy chain with an EGFR-binding light and heavy chain by the “knobs-into-holes” technology. XGFR* is optimized for monovalent binding of human EGFR and IGF-1R with increased binding affinity for IGF-1R due to affinity maturation and highly improved protein stability to oxidative and thermal stress. It bears an afucosylated Fc-portion for optimal induction of antibody-dependent cell-mediated cytotoxicity (ADCC). Stable Chinese hamster ovary cell clones with production yields of 2–3 g/L were generated, allowing for large scale production of the bispecific antibody. XGFR* potently inhibits EGFR- and IGF-1R-dependent receptor phosphorylation, reduces tumor cell proliferation in cells with heterogeneous levels of IGF-1R and EGFR receptor expression and induces strong ADCC in vitro. A comparison of pancreatic and colorectal cancer lines demonstrated superior responsiveness to XGFR*-mediated signaling and tumor growth inhibition in pancreatic cancers that frequently show a high degree of IGF-1R/EGFR co-expression. XGFR* showed potent anti-tumoral efficacy in the orthotopic MiaPaCa-2 pancreatic xenograft model, resulting in nearly complete tumor growth inhibition with significant number of tumor remissions. In summary, the bispecific anti-IGF-1R/EGFR antibody XGFR* combines potent signaling and tumor growth inhibition with enhanced ADCC induction and represents a clinical development candidate for the treatment of pancreatic cancer. PMID:26984378

  11. Cardiac GPCR-Mediated EGFR Transactivation: Impact and Therapeutic Implications.

    Science.gov (United States)

    Grisanti, Laurel A; Guo, Shuchi; Tilley, Douglas G

    2017-07-01

    G protein-coupled receptors (GPCRs) remain primary therapeutic targets for numerous cardiovascular disorders, including heart failure (HF), because of their influence on cardiac remodeling in response to elevated neurohormone signaling. GPCR blockers have proven to be beneficial in the treatment of HF by reducing chronic G protein activation and cardiac remodeling, thereby extending the lifespan of patients with HF. Unfortunately, this effect does not persist indefinitely, thus next-generation therapeutics aim to selectively block harmful GPCR-mediated pathways while simultaneously promoting beneficial signaling. Transactivation of epidermal growth factor receptor (EGFR) has been shown to be mediated by an expanding repertoire of GPCRs in the heart, and promotes cardiomyocyte survival, thus may offer a new avenue of HF therapeutics. However, GPCR-dependent EGFR transactivation has also been shown to regulate cardiac hypertrophy and fibrosis by different GPCRs and through distinct molecular mechanisms. Here, we discuss the mechanisms and impact of GPCR-mediated EGFR transactivation in the heart, focusing on angiotensin II, urotensin II, and β-adrenergic receptor systems, and highlight areas of research that will help us to determine whether this pathway can be engaged as future therapeutic strategy.

  12. Immunohistochemical expression of EGFR in oral leukoplakia: Association with clinicopathological features and cellular proliferation

    Science.gov (United States)

    Ribeiro, Daniela C.; Gleber-Netto, Frederico O.; Sousa, Sílvia F.; Bernardes, Vanessa F.; Guimarães-Abreu, Mauro H.N.

    2012-01-01

    Objectives: to investigate the immunoexpression of epidermal growth factor receptor (EGFR) in a sample of oral leukoplakias (OL) and to determine the receptor’s association with dysplasia, tobacco consumption, lesion site, and proliferation rate. Although EGFR should be overexpressed in some oral leukoplakias, the factors that may interfere with this expression and the influence of this receptor on epithelial proliferation have yet to be investigated. Study Design: Samples of oral leukoplakias (48) and of normal oral epithelium (10) were immunohistologically examined for expression of EGFR. Immunohistochemistry for Ki-67, and p27 were also performed in leukoplakias. EGFR expression was associated with clinical and pathological features. Results: EGFR was positive in 62.5% of the leukoplakias and 50% of normal oral epithelium. The number of EGFR positive OL located in high-risk sites was significantly higher than EGFR positive OL located in low-risk sites. Most of the p27 negative leukoplakias were EGFR positive, and the p27 index in the parabasal layer was diminished in the presence of dysplasia. Positivity for EGFR was not associated with dysplasia, tobacco exposure, or Ki-67. Conclusion: EGFR is expressed in leukoplakia regardless of dysplasia, but EGFR positivity should be more frequent in lesions sited in areas of high cancer risk. The association between EGFR and p27 may represent an important mechanism in the control of cellular proliferation and malignant progression of oral epithelium and therefore warrants further investigation. Key words:Oral leukoplakia, EGFR, p27, Ki-67, epithelial dysplasia. PMID:22322523

  13. Construction of a high-EGFR expression cell line and its biological ...

    African Journals Online (AJOL)

    USER

    2010-07-26

    EGFR ... γ)/protein kinase C (PKC), and the signal transducer and activator of transcription (STAT) .... HEK293 cells. Figure 5. p-EGFR and p-ERK protein expression in HEK293-EGFR and A431 cell lines. expression in the ...

  14. Development of Cu-64 labeled EGF for In Vivo PET Imaging of EGFR Expression

    Energy Technology Data Exchange (ETDEWEB)

    Backer, Joseph M.

    2009-07-12

    In this project we proposed to establish feasibility of the development of targeted tracers for radionuclide imaging of epidermal growth factor receptors (EGFR) in cancer patients. The significance and impact of the proposed radiotracers are determined by the crucial role that EGFR plays in many cancers and by the rapid entrance of EGFR-inhibiting drugs into clinic. Clinical experience, however, revealed that only 10-25% of patients that are defined as EGFR-positive by immunohistochemical analysis respond to EGFR-directed therapeutics and there is poor correlation between EGFR immunohistochemistry and treatment. Therefore, for more efficacious use of EGFR-targeting therapeutics, there is a need for information about EGFR activity in patients. We hypothesized that radionuclide imaging of functionally active EGFR will provide such information and would allow for 1) rational patient stratification, 2) rapid monitoring of responses to therapy, and 3) development of personalized treatment regimens. We hypothesized that tracers based epidermal growth factor (EGF), a natural EGFR ligand, as a targeting vector would be particularly advantageous. First, only functionally active and therefore critical for disease progression EGFRs will bind and internalize an EGF-based tracer. Second, continuous internalization of EGF-based tracers by recyclable EGFR would lead to intracellular accumulation of radionuclide and improved signal-to-background ratio. Third, small size of EGF relative to antibodies would facilitate tumor penetration with vastly better non-specific soft tissue and blood clearance rates. Fourth, as a human protein, EGF is not expected to be immunogenic. Finally, at the beginning of this project, we have already engineered and expressed functionally active EGF with an N-terminal Cys-tag for site-specific conjugation of various payloads, including radionuclide chelators. In the Phase I of this project, in collaboration with Dr. Blankenberg’s group at Stanford

  15. Comparison of a mouse and a novel human scFv-SNAP-auristatin F drug conjugate with potent activity against EGFR-overexpressing human solid tumor cells

    Directory of Open Access Journals (Sweden)

    Woitok M

    2017-07-01

    Full Text Available Mira Woitok,1,2 Diana Klose,1 Stefano Di Fiore,1 Wolfgang Richter,3 Christoph Stein,1 Gerrit Gresch,1 Elena Grieger,1 Stefan Barth,1 Rainer Fischer,1,2 Katharina Kolberg,1,* Judith Niesen1,* 1Fraunhofer Institute for Molecular Biology and Applied Ecology (IME, Aachen, Germany; 2Institute of Molecular Biotechnology (Biology VII, RWTH Aachen University, Aachen, Germany; 3Tube Pharmaceuticals GmbH, Vienna, Austria *These authors contributed equally to this work Abstract: Antibody–drug conjugates (ADCs can deliver toxins to specific targets such as tumor cells. They have shown promise in preclinical/clinical development but feature stoichiometrically undefined chemical linkages, and those based on full-size antibodies achieve only limited tumor penetration. SNAP-tag technology can overcome these challenges by conjugating benzylguanine-modified toxins to single-chain fragment variables (scFvs with 1:1 stoichio­metry while preserving antigen binding. Two (human and mouse scFv-SNAP fusion proteins recognizing the epidermal growth factor receptor (EGFR were expressed in HEK 293T cells. The purified fusion proteins were conjugated to auristatin F (AURIF. Binding activity was confirmed by flow cytometry/immunohistochemistry, and cytotoxic activity was confirmed by cell viability/apoptosis and cell cycle arrest assays, and a novel microtubule dynamics disassembly assay was performed. Both ADCs bound specifically to their target cells in vitro and ex vivo, indicating that the binding activity of the scFv-SNAP fusions was unaffected by conjugation to AURIF. Cytotoxic assays confirmed that the ADCs induced apoptosis and cell cycle arrest at nanomolar concentrations and microtubule disassembly. The SNAP-tag technology provides a platform for the development of novel ADCs with defined conjugation sites and stoichiometry. We achieved the stable and efficient linkage of AURIF to human or murine scFvs using the SNAP-tag technology, offering a strategy to

  16. A Selected Lactobacillus rhamnosus Strain Promotes EGFR-Independent Akt Activation in an Enterotoxigenic Escherichia coli K88-Infected IPEC-J2 Cell Model.

    Directory of Open Access Journals (Sweden)

    Wei Zhang

    Full Text Available Enterotoxigenic Escherichia coli (ETEC are important intestinal pathogens that cause diarrhea in humans and animals. Although probiotic bacteria may protect against ETEC-induced enteric infections, the underlying mechanisms are unknown. In this study, porcine intestinal epithelial J2 cells (IPEC-J2 were pre-incubated with and without Lactobacillus rhamnosus ATCC 7469 and then exposed to F4+ ETEC. Increases in TLR4 and NOD2 mRNA expression were observed at 3 h after F4+ ETEC challenge, but these increases were attenuated by L. rhamnosus treatment. Expression of TLR2 and NOD1 mRNA was up-regulated in cells pre-treated with L. rhamnosus. Pre-treatment with L. rhamnosus counteracted F4+ ETEC-induced increases in TNF-α concentration. Increased PGE2. concentrations were observed in cells infected with F4+ ETEC and in cells treated with L. rhamnosus only. A decrease in phosphorylated epidermal growth factor receptor (EGFR was observed at 3 h after F4+ ETEC challenge in cells treated with L. rhamnosus. Pre-treatment with L. rhamnosus enhanced Akt phosphorylation and increased ZO-1 and occludin protein expression. Our findings suggest that L. rhamnosus protects intestinal epithelial cells from F4+ ETEC-induced damage, partly through the anti-inflammatory response involving synergism between TLR2 and NOD1. In addition, L. rhamnosus promotes EGFR-independent Akt activation, which may activate intestinal epithelial cells in response to bacterial infection, in turn increasing tight junction integrity and thus enhancing the barrier function and restricting pathogen invasion. Pre-incubation with L. rhamnosus was superior to co-incubation in reducing the adhesion of F4+ ETEC to IPEC-J2 cells and subsequently attenuating F4+ ETEC-induced mucin layer destruction and suppressing apoptosis. Our data indicate that a selected L. rhamnosus strain interacts with porcine intestinal epithelial cells to maintain the epithelial barrier and promote intestinal epithelial

  17. A Selected Lactobacillus rhamnosus Strain Promotes EGFR-Independent Akt Activation in an Enterotoxigenic Escherichia coli K88-Infected IPEC-J2 Cell Model.

    Science.gov (United States)

    Zhang, Wei; Zhu, Yao-Hong; Yang, Jin-Cai; Yang, Gui-Yan; Zhou, Dong; Wang, Jiu-Feng

    2015-01-01

    Enterotoxigenic Escherichia coli (ETEC) are important intestinal pathogens that cause diarrhea in humans and animals. Although probiotic bacteria may protect against ETEC-induced enteric infections, the underlying mechanisms are unknown. In this study, porcine intestinal epithelial J2 cells (IPEC-J2) were pre-incubated with and without Lactobacillus rhamnosus ATCC 7469 and then exposed to F4+ ETEC. Increases in TLR4 and NOD2 mRNA expression were observed at 3 h after F4+ ETEC challenge, but these increases were attenuated by L. rhamnosus treatment. Expression of TLR2 and NOD1 mRNA was up-regulated in cells pre-treated with L. rhamnosus. Pre-treatment with L. rhamnosus counteracted F4+ ETEC-induced increases in TNF-α concentration. Increased PGE2. concentrations were observed in cells infected with F4+ ETEC and in cells treated with L. rhamnosus only. A decrease in phosphorylated epidermal growth factor receptor (EGFR) was observed at 3 h after F4+ ETEC challenge in cells treated with L. rhamnosus. Pre-treatment with L. rhamnosus enhanced Akt phosphorylation and increased ZO-1 and occludin protein expression. Our findings suggest that L. rhamnosus protects intestinal epithelial cells from F4+ ETEC-induced damage, partly through the anti-inflammatory response involving synergism between TLR2 and NOD1. In addition, L. rhamnosus promotes EGFR-independent Akt activation, which may activate intestinal epithelial cells in response to bacterial infection, in turn increasing tight junction integrity and thus enhancing the barrier function and restricting pathogen invasion. Pre-incubation with L. rhamnosus was superior to co-incubation in reducing the adhesion of F4+ ETEC to IPEC-J2 cells and subsequently attenuating F4+ ETEC-induced mucin layer destruction and suppressing apoptosis. Our data indicate that a selected L. rhamnosus strain interacts with porcine intestinal epithelial cells to maintain the epithelial barrier and promote intestinal epithelial cell activation in

  18. Cellular Functions Regulated by Phosphorylation of EGFR on Tyr845

    Directory of Open Access Journals (Sweden)

    Ken-ichi Sato

    2013-05-01

    Full Text Available The Src gene product (Src and the epidermal growth factor receptor (EGFR are prototypes of oncogene products and function primarily as a cytoplasmic non-receptor tyrosine kinase and a transmembrane receptor tyrosine kinase, respectively. The identification of Src and EGFR, and the subsequent extensive investigations of these proteins have long provided cutting edge research in cancer and other molecular and cellular biological studies. In 1995, we reported that the human epidermoid carcinoma cells, A431, contain a small fraction of Src and EGFR in which these two kinase were in physical association with each other, and that Src phosphorylates EGFR on tyrosine 845 (Y845 in the Src-EGFR complex. Y845 of EGFR is located in the activation segment of the kinase domain, where many protein kinases contain kinase-activating autophosphorylation sites (e.g., cAMP-dependent protein kinase, Src family kinases, transmembrane receptor type tyrosine kinases or trans-phosphorylation sites (e.g., cyclin-dependent protein kinase, mitogen-activated protein kinase, Akt protein kinase. A number of studies have demonstrated that Y845 phosphorylation serves an important role in cancer as well as normal cells. Here we compile the experimental facts involving Src phosphorylation of EGFR on Y845, by which cell proliferation, cell cycle control, mitochondrial regulation of cell metabolism, gamete activation and other cellular functions are regulated. We also discuss the physiological relevance, as well as structural insights of the Y845 phosphorylation.

  19. 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...... phosphorylation and activation of downstream signaling pathways. Importantly, EphA2 downregulation inhibits EGF-induced cancer cell migration and viability. The EGFR regulated EphA2 expression and functional cross-talk between the two receptor–ligand systems could be very important when targeting either receptor...

  20. Pseudomonas aeruginosa pyocyanin activates NRF2-ARE-mediated transcriptional response via the ROS-EGFR-PI3K-AKT/MEK-ERK MAP kinase signaling in pulmonary epithelial cells.

    Science.gov (United States)

    Xu, Ying; Duan, Chaohui; Kuang, Zhizhou; Hao, Yonghua; Jeffries, Jayme L; Lau, Gee W

    2013-01-01

    The redox-active pyocyanin (PCN) secreted by the respiratory pathogen Pseudomonas aeruginosa generates reactive oxygen species (ROS) and causes oxidative stress to pulmonary epithelial cells. Nuclear factor (erythroid-derived 2)-like 2 (NRF2) confers protection against ROS-mediated cell death by inducing the expression of detoxifying enzymes and proteins via its binding to the cis-acting antioxidant response element (ARE). However, a clear relationship between NRF2 and PCN-mediated oxidative stress has not been established experimentally. In this study, we investigated the induction of NRF2-ARE response by PCN in the pulmonary epithelial cells. We analyzed the effect of PCN on NRF2 expression and nuclear translocation in cultured human airway epithelial cells, and in a mouse model of chronic PCN exposure. NRF2-dependent transcription of antioxidative enzymes was also assessed. Furthermore, we used inhibitors to examine the involvement of EGFR and its downstream signaling components that mediate NRF2-ARE-activation in response to PCN. PCN enhances the nuclear NRF2 accumulation and activates the transcription of ARE-mediated antioxidant genes. Furthermore, PCN activates NRF2 by inducing the EGFR-phosphoinositide-3-kinase (PI3K) signaling pathway and its main downstream effectors, AKT and MEK1/2-ERK1/2 MAP kinases. Inhibition of the EGFR-PI3K signaling markedly attenuates PCN-stimulated NRF2 accumulation in the nucleus. We demonstrate for the first time that PCN-mediated oxidative stress activates the EGFR-PI3K-AKT/MEK1/2-ERK1/2 MAP kinase signaling pathway, leading to nuclear NRF2 translocation and ARE responsiveness in pulmonary epithelial cells.

  1. Pseudomonas aeruginosa pyocyanin activates NRF2-ARE-mediated transcriptional response via the ROS-EGFR-PI3K-AKT/MEK-ERK MAP kinase signaling in pulmonary epithelial cells.

    Directory of Open Access Journals (Sweden)

    Ying Xu

    Full Text Available The redox-active pyocyanin (PCN secreted by the respiratory pathogen Pseudomonas aeruginosa generates reactive oxygen species (ROS and causes oxidative stress to pulmonary epithelial cells. Nuclear factor (erythroid-derived 2-like 2 (NRF2 confers protection against ROS-mediated cell death by inducing the expression of detoxifying enzymes and proteins via its binding to the cis-acting antioxidant response element (ARE. However, a clear relationship between NRF2 and PCN-mediated oxidative stress has not been established experimentally. In this study, we investigated the induction of NRF2-ARE response by PCN in the pulmonary epithelial cells. We analyzed the effect of PCN on NRF2 expression and nuclear translocation in cultured human airway epithelial cells, and in a mouse model of chronic PCN exposure. NRF2-dependent transcription of antioxidative enzymes was also assessed. Furthermore, we used inhibitors to examine the involvement of EGFR and its downstream signaling components that mediate NRF2-ARE-activation in response to PCN. PCN enhances the nuclear NRF2 accumulation and activates the transcription of ARE-mediated antioxidant genes. Furthermore, PCN activates NRF2 by inducing the EGFR-phosphoinositide-3-kinase (PI3K signaling pathway and its main downstream effectors, AKT and MEK1/2-ERK1/2 MAP kinases. Inhibition of the EGFR-PI3K signaling markedly attenuates PCN-stimulated NRF2 accumulation in the nucleus. We demonstrate for the first time that PCN-mediated oxidative stress activates the EGFR-PI3K-AKT/MEK1/2-ERK1/2 MAP kinase signaling pathway, leading to nuclear NRF2 translocation and ARE responsiveness in pulmonary epithelial cells.

  2. A Targetable EGFR-Dependent Tumor-Initiating Program in Breast Cancer

    Directory of Open Access Journals (Sweden)

    Paul Savage

    2017-10-01

    Full Text Available Summary: Therapies targeting epidermal growth factor receptor (EGFR have variable and unpredictable responses in breast cancer. Screening triple-negative breast cancer (TNBC patient-derived xenografts (PDXs, we identify a subset responsive to EGFR inhibition by gefitinib, which displays heterogeneous expression of wild-type EGFR. Deep single-cell RNA sequencing of 3,500 cells from an exceptional responder identified subpopulations displaying distinct biological features, where elevated EGFR expression was significantly enriched in a mesenchymal/stem-like cellular cluster. Sorted EGFRhi subpopulations exhibited enhanced stem-like features, including ALDH activity, sphere-forming efficiency, and tumorigenic and metastatic potential. EGFRhi cells gave rise to EGFRhi and EGFRlo cells in primary and metastatic tumors, demonstrating an EGFR-dependent expansion and hierarchical state transition. Similar tumorigenic EGFRhi subpopulations were identified in independent PDXs, where heterogeneous EGFR expression correlated with gefitinib sensitivity. This provides new understanding for an EGFR-dependent hierarchy in TNBC and for patient stratification for therapeutic intervention. : Savage et al. demonstrate that sensitivity to EGFR inhibitor, gefitinib, in triple-negative breast cancer is paradoxically associated with EGFR heterogeneity. Using single-cell RNA sequencing in conjunction with functional assays, they identify TNBC tumors in which EGFR expression identifies cells with tumor-initiating capacity whose proliferative expansion is sensitive to EGFR inhibition. Keywords: breast cancer, tumor heterogeneity, patient-derived xenograft, single-cell RNA sequencing, EGFR inhibition, therapeutic response, tumor-initiating cell, cell hierarchy, BRCA1 mutation

  3. Potential roles of Centipede Scolopendra extracts as a strategy against EGFR-dependent cancers.

    Science.gov (United States)

    Ma, Weina; Zhang, Dongdong; Zheng, Lei; Zhan, Yingzhuan; Zhang, Yanmin

    2015-01-01

    Centipede Scolopendra, a commonly used traditional Chinese medicine, has been shown to have anti-cancer effects. In this study, the inhibitory effect of alcohol extracts of Centipede Scolopendra (AECS) was more prominent when treating cells highly expressing epidermal growth factor receptor (EGFR) (A431 and HEK293/EGFR cells versus HEK293 cells). The elution profiles of AECS on cell membrane chromatography (CMC) column showed that AECS could bind to EGFR, and competition studies indicated that AECS and gefitinib may have direct competition at a single common binding site on EGFR. SiRNA knockdown of EGFR in A431 cells attenuated AECS effects, suggesting that EGFR was a target mediated by AECS. In a cell culture system, AECS dramatically induced apoptosis of A431 and HEK293/EGFR cells, which was associated with the effects on Bcl-2 family. Furthermore, AECS could alter EGFR kinase activity and reduce phosphorylation of EGFR and downstream signaling players AKT and Erk1/2. The mechanism of AECS to inhibit high-EGFR expression cell proliferation is due to its ability to induce apoptosis and modulate the EGFR pathway. This study might provide a novel therapy for cancer with high-EGFR expression.

  4. Trophoblast subtype-specific EGFR/ERBB4 expression correlates with cell cycle progression and hyperplasia in complete hydatidiform moles.

    Science.gov (United States)

    Fock, Valerie; Plessl, Kerstin; Fuchs, Roman; Dekan, Sabine; Milla, Stephanie K; Haider, Sandra; Fiala, Christian; Knöfler, Martin; Pollheimer, Jürgen

    2015-04-01

    Do trophoblast subtypes differ in their expression of erythroblastic leukaemia viral oncogene homologue (ERBB) receptor family members and responsiveness towards specific growth factor ligands? Our data reveal a reciprocal expression pattern of epidermal growth factor receptor (EGFR)/ERBB4 in proliferative and ERBB2/ERBB3 in invasive trophoblast subtypes, as well as a restricted responsiveness to epidermal growth factor (EGF) and heparin-binding (HB)-EGF. EGFR is expressed by villous cytotrophoblasts (vCTBs), but absent from extravillous trophoblasts (EVTs), which specifically up-regulate ERBB2. Tissue samples of human first trimester placentae (n = 50) and deciduae (n = 5) obtained from elective pregnancy terminations were used to study trophoblast subtype-specific ERBB receptor expression and responsiveness to recombinant human EGF and HB-EGF. Age-matched complete hydatidiform mole (CHM) placentae (n = 12) were assessed for EGFR and ERBB4 expression in proliferation-competent regions. ERBB receptor expression was analysed in primary trophoblast cell isolates by means of microarray, quantitative real-time PCR and western blotting, as well as immunofluorescence stainings of placental and decidual tissue sections. EGF and HB-EGF were tested for their potential to activate ERBB receptors in purified EGFR(+) and HLA-G(+) trophoblasts. 5-Ethynyl-2'-deoxyuridine incorporation assays were performed to study the effect of both ligands on the proliferative capacity of primary trophoblasts as well as of vCTBs and proximal cell column trophoblasts (pCCTs) in placental floating explants. Finally, the average number of EGFR(+) vCTB and pCCT layers was determined in CHM placentae and compared with healthy age-matched controls. Proliferative vCTBs and pCCTs co-express EGFR and ERBB4, but are devoid of ERBB2 and ERBB3. In contrast, HLA-G(+) trophoblast subtypes exhibit an EGFR/ERBB4(-) and ERBB2/ERBB3(+) phenotype. EGF and HB-EGF activate EGFR, ERBB4, AKT and extracellular signal

  5. Γ-Ionizing radiation activated EGFR-p38/ERK-STAT3/CREB-1-EMT pathway for promotion of the migration/invasion of lung cancer cell and its inhibition by podophyllotoxin acetate

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    Cho, Jeong Hyun; Um, Hong Duck; Park, Jong Kuk [Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of)

    2016-05-15

    In this study, we sought to identify the intracellular machinery responsible for IR induced cancer invasion/migration. We report that IR activates the EGFR - p38/ERK - CREB-1/STAT3 pathway, which triggers EMT and increases invasion/migration of lung cancer. Moreover, we show that podophyllotoxin acetate (PA) inhibits IR-induced invasion/migration at least partly by blocking EGFR - p38/ERK - STAT3/ CREB-1signaling and thereby suppressing EMT. Our results revealed that IR increased the invasion/migration of A549 cells, and this effect was decreased by 10 nM PA treatment. PA also inhibited the expressions/activities of matrix metalloprotase (MMP) -2, MMP-9, and vimentin, suggesting that PA could block the IR-induced epithelial-mesenchymal transition (EMT). The IR induced increases in invasion/migration were associated with the activation of EGFR-AKT, and PA inhibited this effect. P38 and p44/42 ERK were also involved in IR induced invasion/migration, and combined treatments with PA plus inhibitors of each MAPK synergistically blocked this invasion/migration. In terms of transcription factors (TFs), IR-induced increases in cyclic AMP response element-binding protein-1 (CREB-1) and signal transducer and activator of transcription 3 (STAT3) increased invasion/migration and EMT. PA also inhibited these transcription factors and then blocked IR-induced invasion/migration.

  6. Spheroid Culture of Head and Neck Cancer Cells Reveals an Important Role of EGFR Signalling in Anchorage Independent Survival.

    Science.gov (United States)

    Braunholz, Diana; Saki, Mohammad; Niehr, Franziska; Öztürk, Merve; Borràs Puértolas, Berta; Konschak, Robert; Budach, Volker; Tinhofer, Ingeborg

    2016-01-01

    In solid tumours millions of cells are shed into the blood circulation each day. Only a subset of these circulating tumour cells (CTCs) survive, many of them presumable because of their potential to form multi-cellular clusters also named spheroids. Tumour cells within these spheroids are protected from anoikis, which allows them to metastasize to distant organs or re-seed at the primary site. We used spheroid cultures of head and neck squamous cell carcinoma (HNSCC) cell lines as a model for such CTC clusters for determining the role of the epidermal growth factor receptor (EGFR) in cluster formation ability and cell survival after detachment from the extra-cellular matrix. The HNSCC cell lines FaDu, SCC-9 and UT-SCC-9 (UT-SCC-9P) as well as its cetuximab (CTX)-resistant sub-clone (UT-SCC-9R) were forced to grow in an anchorage-independent manner by coating culture dishes with the anti-adhesive polymer poly-2-hydroxyethylmethacrylate (poly-HEMA). The extent of apoptosis, clonogenic survival and EGFR signalling under such culture conditions was evaluated. The potential of spheroid formation in suspension culture was found to be positively correlated with the proliferation rate of HNSCC cell lines as well as their basal EGFR expression levels. CTX and gefitinib blocked, whereas the addition of EGFR ligands promoted anchorage-independent cell survival and spheroid formation. Increased spheroid formation and growth were associated with persistent activation of EGFR and its downstream signalling component (MAPK/ERK). Importantly, HNSCC cells derived from spheroid cultures retained their clonogenic potential in the absence of cell-matrix contact. Addition of CTX under these conditions strongly inhibited colony formation in CTX-sensitive cell lines but not their resistant subclones. Altogether, EGFR activation was identified as crucial factor for anchorage-independent survival of HNSCC cells. Targeting EGFR in CTC cluster formation might represent an attractive anti

  7. A functional siRNA screen identifies genes modulating angiotensin II-mediated EGFR transactivation.

    Science.gov (United States)

    George, Amee J; Purdue, Brooke W; Gould, Cathryn M; Thomas, Daniel W; Handoko, Yanny; Qian, Hongwei; Quaife-Ryan, Gregory A; Morgan, Kylie A; Simpson, Kaylene J; Thomas, Walter G; Hannan, Ross D

    2013-12-01

    The angiotensin type 1 receptor (AT1R) transactivates the epidermal growth factor receptor (EGFR) to mediate cellular growth, however, the molecular mechanisms involved have not yet been resolved. To address this, we performed a functional siRNA screen of the human kinome in human mammary epithelial cells that demonstrate a robust AT1R-EGFR transactivation. We identified a suite of genes encoding proteins that both positively and negatively regulate AT1R-EGFR transactivation. Many candidates are components of EGFR signalling networks, whereas others, including TRIO, BMX and CHKA, have not been previously linked to EGFR transactivation. Individual knockdown of TRIO, BMX or CHKA attenuated tyrosine phosphorylation of the EGFR by angiotensin II stimulation, but this did not occur following direct stimulation of the EGFR with EGF, indicating that these proteins function between the activated AT1R and the EGFR. Further investigation of TRIO and CHKA revealed that their activity is likely to be required for AT1R-EGFR transactivation. CHKA also mediated EGFR transactivation in response to another G protein-coupled receptor (GPCR) ligand, thrombin, indicating a pervasive role for CHKA in GPCR-EGFR crosstalk. Our study reveals the power of unbiased, functional genomic screens to identify new signalling mediators important for tissue remodelling in cardiovascular disease and cancer.

  8. Effects of different ligands on epidermal growth factor receptor (EGFR) nuclear translocation

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    Faria, Jerusa A.Q.A.; Andrade, Carolina de; Goes, Alfredo M. [Department of Biochemistry and Immunology, Universidade Federal de Minas Gerais, Av. Antonio Carlos, 6627, Belo Horizonte, MG, 31270-901 (Brazil); Rodrigues, Michele A. [Department of Biochemistry and Immunology, Universidade Federal de Minas Gerais, Av. Antonio Carlos, 6627, Belo Horizonte, MG, 31270-901 (Brazil); Department of General Pathology, Universidade Federal de Minas Gerais, Av. Antonio Carlos, 6627, Belo Horizonte, MG, 31270-901 (Brazil); Gomes, Dawidson A., E-mail: dawidson@ufmg.br [Department of Biochemistry and Immunology, Universidade Federal de Minas Gerais, Av. Antonio Carlos, 6627, Belo Horizonte, MG, 31270-901 (Brazil)

    2016-09-09

    The epidermal growth factor receptor (EGFR) is activated through binding to specific ligands and generates signals for proliferation, differentiation, migration, and cell survival. Recent data show the role of nuclear EGFR in tumors. Although many EGFR ligands are upregulated in cancers, little is known about their effects on EGFR nuclear translocation. We have compared the effects of six EGFR ligands (EGF, HB-EGF, TGF-α, β-Cellulin, amphiregulin, and epiregulin) on nuclear translocation of EGFR, receptor phosphorylation, migration, and proliferation. Cell fractionation and confocal immunofluorescence detected EGFR in the nucleus after EGF, HB-EGF, TGF-α and β-Cellulin stimulation in a dose-dependent manner. In contrast, amphiregulin and epiregulin did not generate nuclear translocation of EGFR. EGF, HB-EGF, TGF-α and β-Cellulin showed correlations between a higher rate of wound closure and increased phosphorylation of residues in the carboxy-terminus of EGFR, compared to amphiregulin and epiregulin. The data indicate that EGFR is translocated to the nucleus after stimulation with EGF, HB-EGF, TGF-α and β-Cellulin, and that these ligands are related to increased phosphorylation of EGFR tyrosine residues, inducing migration of SkHep-1 cells. - Highlights: • EGF, HB-EGF, TGF-α, β-Cellulin are involved in the EGFR nuclear translocation. • Amphiregulin and epiregulin did not promote nuclear translocation of EGFR. • EGF, HB-EGF, TGF-α and β-Cellulin have a role in SkHep-1 cells migration. • EGFR ligands associated with better prognosis don't stimulate EGFR translocation.

  9. Mechanistic insights into EGFR membrane clustering revealed by super-resolution imaging

    Science.gov (United States)

    Gao, Jing; Wang, Ye; Cai, Mingjun; Pan, Yangang; Xu, Haijiao; Jiang, Junguang; Ji, Hongbin; Wang, Hongda

    2015-01-01

    The clustering of membrane receptors such as EGFR is critical for various biological processes, for example cell signaling and tumorigenesis. However, the mechanism involved remains poorly understood. Here, we used a super resolution imaging technique, which has shattered the longstanding resolution barrier of light diffraction, to investigate the distribution of membrane EGFR on apical or basal surfaces of COS-7 cells and on the surface of suspended COS-7 cells. Our data show that more and larger EGFR clusters are detected on the apical surface in comparison with those on the basal surface and this difference is not affected by the EGFR activation state, whereas suspended COS-7 cells exhibit a moderate clustering state and a homogeneous distribution pattern, indicating that the external environment surrounding the cell membrane is the decisive factor in the EGFR clustering pattern. A dual-color dSTORM image reveals the significant colocalization of EGFR and lipid rafts; interestingly MβCD treatment leads to a dramatic decrease of the amount and size of EGFR clusters on both apical and basal surfaces, highlighting a key role of lipid rafts in EGFR cluster formation. Altogether, our results illustrate the distribution pattern of EGFR in polarized cells and uncover the essential role of lipid rafts in EGFR cluster maintenance.The clustering of membrane receptors such as EGFR is critical for various biological processes, for example cell signaling and tumorigenesis. However, the mechanism involved remains poorly understood. Here, we used a super resolution imaging technique, which has shattered the longstanding resolution barrier of light diffraction, to investigate the distribution of membrane EGFR on apical or basal surfaces of COS-7 cells and on the surface of suspended COS-7 cells. Our data show that more and larger EGFR clusters are detected on the apical surface in comparison with those on the basal surface and this difference is not affected by the EGFR

  10. The EGFR Inhibitor Gefitinib Enhanced the Response of Human Oral Squamous Cell Carcinoma to Cisplatin In Vitro.

    Science.gov (United States)

    Khalil, Ashraf; Jameson, Mark J

    2017-12-01

    The epidermal growth factor receptor (EGFR) is highly expressed in a variety of solid tumors including oral cavity squamous cell carcinoma (OSCC) and has been implicated in the resistance of these tumors to cisplatin. This study was performed to determine if the EGFR tyrosine kinase inhibitor gefitinib could enhance the cytotoxic effect of cisplatin on OSCC cells in vitro. The expression of EGFR and the phosphorylation of its downstream signaling to ERK, and AKT pathway were detected by Western blotting. Cell proliferation and survival were determined by AlamarBlue and colony formation assay respectively. Cells apoptosis were determined by Western blotting for cleaved PARP protein and by flowcytometry of cells stained with Annexin V and PI. Cal27, OSC19, and SCC25 cells treated with gefitinib 1 μM demonstrated reduced phosphorylation of EGFR, AKT, and ERK proteins with very limited inhibition of proliferation. Cisplatin inhibited proliferation of the same cell lines in a dose-dependent manner. The concentration producing 50% inhibition (IC50) for cisplatin decreased in the presence of gefitinib 1 μM, and a combination of cisplatin 5 µM and gefitinib 1 µM caused synergistic growth inhibition and synergistic reduction in cell survival. The growth inhibitory effect of the combination was associated with reduced ERK and AKT activation, increased poly ADP ribose polymerase (PARP) cleavage, and increased apoptosis. Thus, in OSCC cells in vitro, inhibition of EGFR activity with gefitinib enhances the apoptotic effect of cisplatin. This has potential implications for enhancement of cisplatin effectiveness in tumors that over-express the EGFR.

  11. Epidermal growth factor receptor activation in glioblastoma through novel missense mutations in the extracellular domain.

    Directory of Open Access Journals (Sweden)

    Jeffrey C Lee

    2006-12-01

    Full Text Available Protein tyrosine kinases are important regulators of cellular homeostasis with tightly controlled catalytic activity. Mutations in kinase-encoding genes can relieve the autoinhibitory constraints on kinase activity, can promote malignant transformation, and appear to be a major determinant of response to kinase inhibitor therapy. Missense mutations in the EGFR kinase domain, for example, have recently been identified in patients who showed clinical responses to EGFR kinase inhibitor therapy.Encouraged by the promising clinical activity of epidermal growth factor receptor (EGFR kinase inhibitors in treating glioblastoma in humans, we have sequenced the complete EGFR coding sequence in glioma tumor samples and cell lines. We identified novel missense mutations in the extracellular domain of EGFR in 13.6% (18/132 of glioblastomas and 12.5% (1/8 of glioblastoma cell lines. These EGFR mutations were associated with increased EGFR gene dosage and conferred anchorage-independent growth and tumorigenicity to NIH-3T3 cells. Cells transformed by expression of these EGFR mutants were sensitive to small-molecule EGFR kinase inhibitors.Our results suggest extracellular missense mutations as a novel mechanism for oncogenic EGFR activation and may help identify patients who can benefit from EGFR kinase inhibitors for treatment of glioblastoma.

  12. Non-invasive urine testing of EGFR activating mutation and T790M resistance mutation in non-small cell lung cancer.

    Science.gov (United States)

    Berz, David; Raymond, Victoria M; Garst, Jordan H; Erlander, Mark G

    2015-01-01

    The increasing understanding of non-small cell lung cancer (NSCLC) biology over the last two decades has led to the identification of multiple molecular targets. This led to the development of multiple targeted therapies in the primary and secondary resistance setting and the epidermal growth factor receptor (EGFR) gene remains the most frequently observed molecular target in NSCLC. Tissue biopsies remain the standard for the identification of such EGFR mutations. Obtaining serial tissue biopsies, especially in the secondary resistance setting is associated with multiple medical and logistical challenges. Utilizing circulating tumor DNA (ctDNA) fragments for molecular analysis can overcome these challenges and aid in therapeutic decision-making. Here we present a present a 72-year-old Korean woman with metastatic, EGFR L858R mutated bronchogenic adenocarcinoma. She developed skeletal progression on treatment with first and second generation tyrosine kinase inhibitors (TKIs). Repeated biopsies failed to provide informative molecular test results. A novel urine ctDNA assay was utilized and confirmed T790M positive status. The patient was started on a third generation TKI, which led to a measurable clinical response. Utilization of urine liquid biopsies for EGFR diagnostics are feasible and provided critical clinical information in this patient's case. Urine liquid biopsy represents a viable alternative to tissue biopsy, particularly in the secondary resistance setting, when tissue is not available for molecular testing.

  13. EGFR and KRAS mutations in lung carcinomas in the Dutch population: increased EGFR mutation frequency in malignant pleural effusion of lung adenocarcinoma.

    NARCIS (Netherlands)

    Smits, A.J.A.; Kummer, J.A.; Hinrichs, J.W.; Herder, G.J.; Scheidel-Jacobse, K.C.; Jiwa, N.M.; Ruijter, T.E.G.; Nooijen, P.T.G.A.; Looijen-Salamon, M.G.; Ligtenberg, M.J.L.; Thunnissen, F.B.J.M.; Heideman, D.A.; Weger, R.A. de; Vink, A.

    2012-01-01

    BACKGROUND: Frequencies of EGFR and KRAS mutations in non-small cell lung cancer (NSCLC) have predominantly been determined in East Asian and North American populations, showing large differences between these populations. The aim of the present study was to determine the frequency of EGFR and KRAS

  14. Reversing EGFR Mediated Immunoescape by Targeted Monoclonal Antibody Therapy

    OpenAIRE

    Fernando Concha-Benavente; Ferris, Robert L.

    2017-01-01

    Uncontrolled growth is a signature of carcinogenesis, in part mediated by overexpression or overstimulation of growth factor receptors. The epidermal growth factor receptor (EGFR) mediates activation of multiple oncogenic signaling pathways and escape from recognition by the host immune system. We discuss how EGFR signaling downregulates tumor antigen presentation, upregulates suppressive checkpoint receptor ligand programmed death ligand (PD-L1), induces secretion of inhibitory molecules suc...

  15. Expression and clinical value of EGFR in human meningiomas

    Directory of Open Access Journals (Sweden)

    Magnus B. Arnli

    2017-03-01

    Full Text Available Background Meningiomas are common intracranial tumors in humans that frequently recur despite having a predominantly benign nature. Even though these tumors have been shown to commonly express EGFR/c-erbB1 (epidermal growth factor receptor, results from previous studies are uncertain regarding the expression of either intracellular or extracellular domains, cellular localization, activation state, relations to malignancy grade, and prognosis. Aims This study was designed to investigate the expression of the intracellular and extracellular domains of EGFR and of the activated receptor as well as its ligands EGF and TGFα in a large series of meningiomas with long follow-up data, and investigate if there exists an association between antibody expression and clinical and histological data. Methods A series of 186 meningiomas consecutively operated within a 10-year period was included. Tissue microarrays were constructed and immunohistochemically analyzed with antibodies targeting intracellular and extracellular domains of EGFR, phosphorylated receptor, and EGF and TGFα. Expression levels were recorded as a staining index (SI. Results Positive immunoreactivity was observed for all antibodies in most cases. There was in general high SIs for the intracellular domain of EGFR, phosphorylated EGFR, EGF, and TGFα but lower for the extracellular domain. Normal meninges were negative for all antibodies. Higher SIs for the phosphorylated EGFR were observed in grade II tumors compared with grade I (p = 0.018. Survival or recurrence was significantly decreased in the time to recurrence analysis (TTR with high SI-scores of the extracellular domain in a univariable survival analysis (HR 1.152, CI (1.036–1.280, p = 0.009. This was not significant in a multivariable analysis. Expression of the other antigens did not affect survival. Conclusion EGFR is overexpressed and in an activated state in human meningiomas. High levels of ligands also support this

  16. Enteropathogenic Escherichia coli dynamically regulates EGFR signaling in intestinal epithelial cells.

    Science.gov (United States)

    Roxas, Jennifer Lising; Ryan, Katheryn; Vedantam, Gayatri; Viswanathan, V K

    2014-08-01

    The diarrheagenic pathogen enteropathogenic Escherichia coli (EPEC) dynamically modulates the survival of infected host intestinal epithelial cells. In the initial stages of infection, several prosurvival signaling events are activated in host cells. These include the phosphorylation of epidermal growth factor receptor (EGFR) and the consequent activation of the phosphatidylinositol-3 kinase/Akt pathway. While studying this pathway in infected epithelial cells, we observed EGFR depletion at later stages of infection, followed subsequently by a decrease in phospho-EGFR. EGFR loss was not dependent on receptor phosphorylation, or on canonical proteasome- and lysosome-dependent processes. Although a type III secretion mutant (ΔescN) stimulated EGFR phosphorylation, it failed to induce receptor degradation. To identify the specific EPEC effector molecule(s) that influenced EGFR stability, epithelial cells infected with isogenic mutant EPEC strains were examined. An EPEC ΔespF strain failed to induce EGFR degradation, whereas EPEC ΔespZ accentuated receptor loss in infected cells. Given the known and contrasting effects of EspF and EspZ on caspase activation, and the known role of proteases in cleaving EGFR, we explored the effect of caspase inhibitors on infection-dependent EGFR loss. The pan-caspase inhibitor Q-VD-OPh blocked EPEC-induced EGFR cleavage in a dose-dependent manner. Taken together, our data suggest that EPEC EspF stimulates caspase-dependent EGFR cleavage and loss, whereas EspZ inhibits this process. Whereas EGFR phosphorylation contributes to the survival of host cells early in infection, EspF-driven caspase activation and consequent EGFR loss likely induce a precipitous increase in host cell death later in the infectious process. Copyright © 2014 the American Physiological Society.

  17. Prediction for response duration to epidermal growth factor receptor-tyrosine kinase inhibitors in EGFR mutated never smoker lung adenocarcinoma.

    Science.gov (United States)

    Kim, Hye Ryun; Cho, Byoung Chul; Shim, Hyo Sup; Lim, Sun Min; Kim, Se Kyu; Chang, Joon; Kim, Dae Joon; Kim, Joo Hang

    2014-03-01

    Among non-small cell lung cancer (NSCLC) patients harboring activating epidermal growth factor receptor (EGFR) mutations, ∼ 20-30% exhibit de novo resistance to EGFR-tyrosine kinase inhibitor (TKI). The aim of this study was to examine whether mutations in the EGFR-downstream genes may be associated with de novo resistance to EGFR-TKIs in EGFR mutation-positive patients. Sixty-eight never-smoker adenocarcinoma patients with an activating EGFR mutation were included in the mutational analysis and 55 patients treated with EGFR-TKIs were analyzed for the treatment outcomes to EGFR-TKIs. We concurrently analyzed mutations in PIK3CA, PTEN, AKT and STK11, which are all EGFR-downstream genes. Mutations in PIK3CA, PTEN, AKT, and STK11 were analyzed by polymerase chain reaction-based sequencing. PIK3CA mutations were detected in 4.4% (3/68) of patients, PTEN mutations in 16.1% (11/68), AKT mutations in 5.9% (4/68), and STK11 mutations in 13.2% (9/68). One patient with an activating exon 21 L858R mutation concomitantly had an exon 20 T790M mutation in EGFR. The proportion of patients who had mutations in EGFR-downstream genes was 32.4% (22/68). When we analyzed the treatment outcome of 55 patients treated with EGFR-TKI, the presence of mutations in EGFR-downstream genes correlated with a poor overall response rate to EGFR-TKIs (63.6 vs.14.5% in patients with mutation in EGFR-downstream gene, Padenocarcinoma patients with activating EGFR mutations. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  18. Correlation of EGFR or KRAS mutation status with 18F-FDG uptake on PET-CT scan in lung adenocarcinoma.

    Science.gov (United States)

    Takamochi, Kazuya; Mogushi, Kaoru; Kawaji, Hideya; Imashimizu, Kota; Fukui, Mariko; Oh, Shiaki; Itoh, Masayoshi; Hayashizaki, Yoshihide; Ko, Weijey; Akeboshi, Masao; Suzuki, Kenji

    2017-01-01

    18F-fluoro-2-deoxy-glucose (18F-FDG) positron emission tomography (PET) is a functional imaging modality based on glucose metabolism. The correlation between EGFR or KRAS mutation status and the standardized uptake value (SUV) of 18F-FDG PET scanning has not been fully elucidated. Correlations between EGFR or KRAS mutation status and clinicopathological factors including SUVmax were statistically analyzed in 734 surgically resected lung adenocarcinoma patients. Molecular causal relationships between EGFR or KRAS mutation status and glucose metabolism were then elucidated in 62 lung adenocarcinomas using cap analysis of gene expression (CAGE), a method to determine and quantify the transcription initiation activities of mRNA across the genome. EGFR and KRAS mutations were detected in 334 (46%) and 83 (11%) of the 734 lung adenocarcinomas, respectively. The remaining 317 (43%) patients had wild-type tumors for both genes. EGFR mutations were more frequent in tumors with lower SUVmax. In contrast, no relationship was noted between KRAS mutation status and SUVmax. CAGE revealed that 4 genes associated with glucose metabolism (GPI, G6PD, PKM2, and GAPDH) and 5 associated with the cell cycle (ANLN, PTTG1, CIT, KPNA2, and CDC25A) were positively correlated with SUVmax, although expression levels were lower in EGFR-mutated than in wild-type tumors. No similar relationships were noted with KRAS mutations. EGFR-mutated adenocarcinomas are biologically indolent with potentially lower levels of glucose metabolism than wild-type tumors. Several genes associated with glucose metabolism and the cell cycle were specifically down-regulated in EGFR-mutated adenocarcinomas.

  19. Correlation of EGFR or KRAS mutation status with 18F-FDG uptake on PET-CT scan in lung adenocarcinoma.

    Directory of Open Access Journals (Sweden)

    Kazuya Takamochi

    Full Text Available 18F-fluoro-2-deoxy-glucose (18F-FDG positron emission tomography (PET is a functional imaging modality based on glucose metabolism. The correlation between EGFR or KRAS mutation status and the standardized uptake value (SUV of 18F-FDG PET scanning has not been fully elucidated.Correlations between EGFR or KRAS mutation status and clinicopathological factors including SUVmax were statistically analyzed in 734 surgically resected lung adenocarcinoma patients. Molecular causal relationships between EGFR or KRAS mutation status and glucose metabolism were then elucidated in 62 lung adenocarcinomas using cap analysis of gene expression (CAGE, a method to determine and quantify the transcription initiation activities of mRNA across the genome.EGFR and KRAS mutations were detected in 334 (46% and 83 (11% of the 734 lung adenocarcinomas, respectively. The remaining 317 (43% patients had wild-type tumors for both genes. EGFR mutations were more frequent in tumors with lower SUVmax. In contrast, no relationship was noted between KRAS mutation status and SUVmax. CAGE revealed that 4 genes associated with glucose metabolism (GPI, G6PD, PKM2, and GAPDH and 5 associated with the cell cycle (ANLN, PTTG1, CIT, KPNA2, and CDC25A were positively correlated with SUVmax, although expression levels were lower in EGFR-mutated than in wild-type tumors. No similar relationships were noted with KRAS mutations.EGFR-mutated adenocarcinomas are biologically indolent with potentially lower levels of glucose metabolism than wild-type tumors. Several genes associated with glucose metabolism and the cell cycle were specifically down-regulated in EGFR-mutated adenocarcinomas.

  20. EGFR tyrosine kinases inhibitors in cancer treatment: in vitro and in vivo evidence.

    Science.gov (United States)

    Quatrale, Anna Elisa; Porcelli, Letizia; Silvestris, Nicola; Colucci, Giuseppe; Angelo, Angelo; Azzariti, Amalia

    2011-01-01

    The increasing understanding of the molecular mechanisms of neoplastic transformation and progression has prompted the search for novel drugs that could interfere with the intracellular targets involved in this process. EGFR is implicated in the development and progression of the majority of the common human epithelial cancer; therefore different agents have been developed to block EGFR activation in cancer cells. This review focuses on EGFR-tyrosine kinase inhibitors in clinical practice that interfere with ATP binding, inhibiting tyrosine kinase activity and subsequently blocking signal transduction from EGFR. We report current knowledge on molecular mechanisms underlying the anticancer activity of EGFR-tyrosine kinase inhibitors in preclinical models, with particular attention to EGFR downstream effectors responsible for treatment efficacy or resistance.

  1. Exosome production and its regulation of EGFR during wound healing in renal tubular cells.

    Science.gov (United States)

    Zhou, Xiangjun; Zhang, Wei; Yao, Qisheng; Zhang, Hao; Dong, Guie; Zhang, Ming; Liu, Yutao; Chen, Jian-Kang; Dong, Zheng

    2017-06-01

    Kidney repair following injury involves the reconstitution of a structurally and functionally intact tubular epithelium. Growth factors and their receptors, such as EGFR, are important in the repair of renal tubules. Exosomes are cell-produced small (~100 nm in diameter) vesicles that contain and transfer proteins, lipids, RNAs, and DNAs between cells. In this study, we examined the relationship between exosome production and EGFR activation and the potential role of exosome in wound healing. EGFR activation occurred shortly after scratch wounding in renal tubular cells. Wound repair after scratching was significantly promoted by EGF and suppressed by EGFR inhibitor gefitinib. Interestingly, scratch wounding induced a significant increase of exosome production. The exosome production was decreased by EGF and increased by gefitinib, suggesting a suppressive role of EGFR signaling in exosome production. Conversely, inhibition of exosome release by GW4869 and manumycin A markedly increased EGFR activation and promoted wound healing. Moreover, exosomes derived from scratch-wounding cells could inhibit wound healing. Collectively, the results indicate that wound healing in renal tubular cells is associated with EGFR activation and exosome production. Although EGFR activation promotes wound healing, released exosomes may antagonize EGFR activation and wound healing. Copyright © 2017 the American Physiological Society.

  2. Prevalence of EGFR Mutations in Lung Cancer in Uruguayan Population

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    Nora Berois

    2017-01-01

    Full Text Available Background. Incorporation of molecular analysis of the epidermal growth factor receptor (EGFR gene into routine clinical practice represents a milestone for personalized therapy of the non-small-cell lung cancer (NSCLC. However, the genetic testing of EGFR mutations has not yet become a routine clinical practice in developing countries. In view of different prevalence of such mutations among different ethnicities and geographic regions, as well as the limited existing data from Latin America, our aim was to study the frequency of major types of activating mutations of the EGFR gene in NSCLC patients from Uruguay. Methods. We examined EGFR mutations in exons 18 through 21 in 289 NSCLC Uruguayan patients by PCR-direct sequencing. Results. EGFR mutations were detected in 53 of the 289 (18.3% patients, more frequently in women (23.4% than in men (14.5%. The distribution by exon was similar to that generally reported in the literature. Conclusions. This first epidemiological study of EGFR mutations in Uruguay reveals a wide spectrum of mutations and an overall prevalence of 18.3%. The background ethnic structure of the Uruguayan population could play an important role in explaining our findings.

  3. Epidermal growth factor receptor (EGFR) mutations in lung cancer: preclinical and clinical data

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    Jorge, S.E.D.C.; Kobayashi, S.S.; Costa, D.B. [Harvard Medical School, Beth Israel Deaconess Medical Center, Department of Medicine, Division of Hematology/Oncology, Boston, MA (United States)

    2014-09-05

    Lung cancer leads cancer-related mortality worldwide. Non-small-cell lung cancer (NSCLC), the most prevalent subtype of this recalcitrant cancer, is usually diagnosed at advanced stages, and available systemic therapies are mostly palliative. The probing of the NSCLC kinome has identified numerous nonoverlapping driver genomic events, including epidermal growth factor receptor (EGFR) gene mutations. This review provides a synopsis of preclinical and clinical data on EGFR mutated NSCLC and EGFR tyrosine kinase inhibitors (TKIs). Classic somatic EGFR kinase domain mutations (such as L858R and exon 19 deletions) make tumors addicted to their signaling cascades and generate a therapeutic window for the use of ATP-mimetic EGFR TKIs. The latter inhibit these kinases and their downstream effectors, and induce apoptosis in preclinical models. The aforementioned EGFR mutations are stout predictors of response and augmentation of progression-free survival when gefitinib, erlotinib, and afatinib are used for patients with advanced NSCLC. The benefits associated with these EGFR TKIs are limited by the mechanisms of tumor resistance, such as the gatekeeper EGFR-T790M mutation, and bypass activation of signaling cascades. Ongoing preclinical efforts for treating resistance have started to translate into patient care (including clinical trials of the covalent EGFR-T790M TKIs AZD9291 and CO-1686) and hold promise to further boost the median survival of patients with EGFR mutated NSCLC.

  4. Identification of EGFR Mutations by Immunohistochemistry with EGFR Mutation-Specific Antibodies in Biopsy and Resection Specimens from Pulmonary Adenocarcinoma.

    Science.gov (United States)

    Kim, Chi Hong; Kim, Seung Hoon; Park, Sonya Youngju; Yoo, Jinyoung; Kim, Sung Kyoung; Kim, Hoon Kyo

    2015-10-01

    Mutation-specific antibodies have recently been developed for identification of epidermal growth factor receptor (EGFR) mutations by immunohistochemistry (IHC). This study was designed to investigate whether the type of specimen (biopsy vs. resection) would make a difference in determining mutation status by IHC, and to evaluate whether biopsies are suitable for detection of mutant EGFR protein. IHC was performed using mutation-specific antibodies for E746-A750 deletion (DEL) and L858R point mutation (L858R) in biopsies and tissue microarrays of resected tumors from 154 patients with pulmonary adenocarcinoma. Results were then compared with DNA sequencing data. Molecular-based assays detected EGFR mutations in 62 patients (40.3%), including 14 (9.1%) with DEL, and 31 (20.1%) with L858R. IHC with two mutation-specific antibodies showed a homogeneous staining pattern, and correctly identified EGFR mutation status in 89% (137/154). Overall (biopsy/resection) sensitivity, specificity, positive predictive value, and negative predictive value were 75.6% (78.3%/72.7%), 94.5% (90.9%/96.3%), 85% (78.3%/88.9%), and 90.4% (90.9%/89.7%), respectively. Our data showed that IHC using EGFR mutation-specific antibodies is useful for detection of EGFR mutations with high specificity and good sensitivity not only for resection specimens but also for biopsy materials. Therefore, IHC using EGFR mutation-specific antibodies may preclude a second biopsy procedure to obtain additional tissues for identification of EGFR mutations by molecular assays in biopsies from advanced cancer, particularly when tumor cells in the samples are limited.

  5. Erlotinib therapy after initial platinum doublet therapy in patients with EGFR wild type non-small cell lung cancer: results of a combined patient-level analysis of the NCIC CTG BR.21 and SATURN trials.

    Science.gov (United States)

    Osarogiagbon, Raymond U; Cappuzzo, Federico; Ciuleanu, Tudor; Leon, Larry; Klughammer, Barbara

    2015-08-01

    The clinical benefit of erlotinib in treating epidermal growth factor receptor (EGFR) wildtype non-small cell lung cancer (NSCLC) has been questioned. We examined the impact of erlotinib in confirmed EGFR wildtype patients in two placebo-controlled phase III trials: the National Cancer Institute of Canada Clinical Trials Group BR.21 (BR.21) and Sequential Tarceva in Unresectable Non-Small Cell Lung Cancer (SATURN) trials. Combined re-analysis of progression-free survival (PFS) and overall survival (OS) in patients with known wildtype EGFR, estimated by Kaplan-Meier curves and compared by two-sided log-rank test. Cox proportional hazards model was used to estimate hazard ratios (HR) adjusted for potential confounders. Additional analyses assessed comparability of patients with known and unknown EGFR mutation status to determine generalizability of the two study populations. Mutation status was known in 25% (n=184 of 731) of the BR.21, and 49% (n=437 of 889) of the SATURN populations, of which 82% (n=150) and 89% (n=388) respectively had wildtype EGFR. HR for PFS was 0.71 (95% CI, 0.59-0.85; P<0.01) and for OS was 0.72 (95% CI, 0.59-0.88; P<0.01). Baseline characteristics and outcome (PFS and OS) distributions were similar for patients with known and unknown EGFR status, suggesting generalizability of the EGFR wildtype data. Erlotinib benefit was sustained in all clinical subsets. Erlotinib provided a consistent and significant improvement in survival for patients with EGFR wildtype NSCLC in both studies, individually and in combination. The benefit of erlotinib does not appear to be limited to patients with activating mutations of EGFR.

  6. Adaptive and Acquired Resistance to EGFR Inhibitors Converge on the MAPK Pathway.

    Science.gov (United States)

    Ma, Pengfei; Fu, Yujie; Chen, Minjiang; Jing, Ying; Wu, Jie; Li, Ke; Shen, Ying; Gao, Jian-Xin; Wang, Mengzhao; Zhao, Xiaojing; Zhuang, Guanglei

    2016-01-01

    Both adaptive and acquired resistance significantly limits the efficacy of the epidermal growth factor receptor (EGFR) kinase inhibitors. However, the distinct or common mechanisms of adaptive and acquired resistance have not been fully characterized. Here, through systematic modeling of erlotinib resistance in lung cancer, we found that feedback reactivation of MAPK signaling following erlotinib treatment, which was dependent on the MET receptor, contributed to the adaptive resistance of EGFR inhibitors. Interestingly, acquired resistance to erlotinib was also associated with the MAPK pathway activation as a result of CRAF or NRAS amplification. Consequently, combined inhibition of EGFR and MAPK impeded the development of both adaptive and acquired resistance. These observations demonstrate that adaptive and acquired resistance to EGFR inhibitors can converge on the same pathway and credential cotargeting EGFR and MAPK as a promising therapeutic approach in EGFR mutant tumors.

  7. Gene expression profiles of lung adenocarcinoma linked to histopathological grading and survival but not to EGF-R status: a microarray study

    Directory of Open Access Journals (Sweden)

    Passlick Bernward

    2010-03-01

    Full Text Available Abstract Background Several different gene expression signatures have been proposed to predict response to therapy and clinical outcome in lung adenocarcinoma. Herein, we investigate if elements of published gene sets can be reproduced in a small dataset, and how gene expression profiles based on limited sample size relate to clinical parameters including histopathological grade and EGFR protein expression. Methods Affymetrix Human Genome U133A platform was used to obtain gene expression profiles of 28 pathologically and clinically annotated adenocarcinomas of the lung. EGFR status was determined by fluorescent in situ hybridization and immunohistochemistry. Results Using unsupervised clustering algorithms, the predominant gene expression signatures correlated with the histopathological grade but not with EGFR protein expression as detected by immunohistochemistry. In a supervised analysis, the signature of high grade tumors but not of EGFR overexpressing cases showed significant enrichment of gene sets reflecting MAPK activation and other potential signaling cascades downstream of EGFR. Out of four different previously published gene sets that had been linked to prognosis, three showed enrichment in the gene expression signature associated with favorable prognosis. Conclusions In this dataset, histopathological tumor grades but not EGFR status were associated with dominant gene expression signatures and gene set enrichment reflecting oncogenic pathway activation, suggesting that high immunohistochemistry EGFR scores may not necessarily be linked to downstream effects that cause major changes in gene expression patterns. Published gene sets showed association with patient survival; however, the small sample size of this study limited the options for a comprehensive validation of previously reported prognostic gene expression signatures.

  8. Flavopiridol Synergizes with Sorafenib to Induce Cytotoxicity and Potentiate Antitumorigenic Activity in EGFR/HER-2 and Mutant RAS/RAF Breast Cancer Model Systems

    Directory of Open Access Journals (Sweden)

    Teddy S Nagaria

    2013-08-01

    Full Text Available Oncogenic receptor tyrosine kinase (RTK signaling through the Ras-Raf-Mek-Erk (Ras-MAPK pathway is implicated in a wide array of carcinomas, including those of the breast. The cyclin-dependent kinases (CDKs are implicated in regulating proliferative and survival signaling downstream of this pathway. Here, we show that CDK inhibitors exhibit an order of magnitude greater cytotoxic potency than a suite of inhibitors targeting RTK and Ras-MAPK signaling in cell lines representative of clinically recognized breast cancer (BC subtypes. Drug combination studies show that the pan-CDK inhibitor, flavopiridol (FPD, synergistically potentiated cytotoxicity induced by the Raf inhibitor, sorafenib (SFN. This synergy was most pronounced at sub-EC50 SFN concentrations in MDA-MB-231 (KRAS-G13D and BRAF-G464V mutations, MDA-MB-468 [epidermal growth factor receptor (EGFR overexpression], and SKBR3 [ErbB2/EGFR2 (HER-2 overexpression] cells but not in hormone-dependent MCF-7 and T47D cells. Potentiation of SFN cytotoxicity by FPD correlated with enhanced apoptosis, suppression of retinoblastoma (Rb signaling, and reduced Mcl-1 expression. SFN and FPD were also tested in an MDA-MB-231 mammary fat pad engraftment model of tumorigenesis. Mice treated with both drugs exhibited reduced primary tumor growth rates and metastatic tumor load in the lungs compared to treatment with either drug alone, and this correlated with greater reductions in Rb signaling and Mcl-1 expression in resected tumors. These findings support the development of CDK and Raf co-targeting strategies in EGFR/HER-2-overexpressing or RAS/RAF mutant BCs.

  9. Protein tyrosine phosphatase SHP-1 sensitizes EGFR/HER-2 positive breast cancer cells to trastuzumab through modulating phosphorylation of EGFR and HER-2.

    Science.gov (United States)

    Wu, Yifen; Li, Rong; Zhang, Junyi; Wang, Gang; Liu, Bin; Huang, Xiaofang; Zhang, Tao; Luo, Rongcheng

    2015-01-01

    Trastuzumab resistance in HER-2 positive breast cancer cells is closely related to overexpression of both epidermal growth factor receptor (EGFR) and human epidermal receptor (HER-2). SHP-1 has been demonstrated to downregulate tyrosine kinase activity including EGFR via its phosphatase function, but its effect on HER-2 activity is still unknown. Here, we examined the hypothesis that SHP-1 enhances the anticancer efficacy of trastuzumab in EGFR/HER-2 positive breast cancer cells through combining dual inhibition of EGFR and HER-2. Trastuzumab-resistant breast cancer SKBr-3 cells were generated by long-term in vitro culture of SKBr-3cells in the presence of trastuzumab. The SHP-1 was ectopically expressed by stable transfection. The activity and expression of EGFR, HER-2, and downstream signaling pathways were tested by Western blot. Cell viability was examined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, and apoptosis was examined by flow cytometry. The binding between SHP-1 and EGFR/HER-2 was evaluated by immunoprecipitation assay and bimolecular fluorescence complementation. The effects of SHP-1 on tumorigenicity and trastuzumab sensitivity were confirmed via in vivo xenograft model. Trastuzumab-resistant SKBr-3 cells showed aberrant co-expression of EGFR and HER-2. Introduction of wild-type SHP-1 inhibited cell proliferation, clone formation, and promoted the apoptosis induced by trastuzumab. Meanwhile, SHP-1 overexpression reduced phosphorylation levels of EGFR and HER-2 both in parental and trastuzumab-resistant SKBr-3 cells. In vivo study showed an increased antitumor effect of trastuzumab in SHP-1 overexpressed xenografts. At last, we discovered that SHP-1 can make complexes with both EGFR and HER-2, and both phospho-EGFR and phosphor-HER-2 levels in wild-type SHP-1 immunoprecipitates were less than those in phosphatase-inactive SHP-1 (C453S) immunoprecipitates, indicating that EGFR and HER-2 are potential substrates of

  10. Epidermal Growth Factor Receptor (EGFR)-targeted Photoimmunotherapy (PIT) for the Treatment of EGFR-expressing Bladder Cancer.

    Science.gov (United States)

    Railkar, Reema; Krane, L Spencer; Li, Q Quentin; Sanford, Thomas; Siddiqui, Mohammad Rashid; Haines, Diana; Vourganti, Srinivas; Brancato, Sam J; Choyke, Peter L; Kobayashi, Hisataka; Agarwal, Piyush K

    2017-10-01

    The use of light as a means of therapy for bladder cancer has a long history but has been hampered by a lack of tumor specificity and therefore, damage to the normal bladder mucosa. Here, we describe a targeted form of phototherapy called photoimmunotherapy (PIT), which targets EGFR-expressing bladder cancer. Anti-EGFR antibody panitumumab was labeled with the photoabsorber (PA), IRDye 700Dx (IR700), to create a panitumumab-IR700 antibody-PA conjugate that is activated by near-infrared radiation (NIR). Bladder cancer tissue microarray (TMA) and bladder cancer cell lines were analyzed for expression of EGFR. Mechanism of PIT-induced cell death was studied using proliferation assays, transmission electron microscopy (TEM), and production of reactive oxygen species. Finally, the in vivo effect was studied in xenografts. EGFR staining of TMAs showed that while most bladder cancers have expression of EGFR to a varying degree, squamous cell carcinomas (SCC) have the highest expression of EGFR. Panitumumab-IR700 activated by NIR light rapidly killed UMUC-5 cells, a bladder SCC line. Panitumumab alone, panitumumab-IR700 without NIR, or NIR alone had no effect on cells. TEM demonstrated that cell death is due to necrosis. Singlet oxygen species contributed toward cell death. NIR-PIT with panitumumab-IR700 reduced growth compared with only panitumumab-IR700-treated UMUC-5 xenograft tumors. PIT is a new targeted treatment for bladder cancer. Panitumumab-IR700-induced PIT selectively kills EGFR-expressing bladder cancer cells in vitro and in vivo and therefore warrants further therapeutic studies in orthotopic xenografts of bladder cancer and ultimately in patients. Mol Cancer Ther; 16(10); 2201-14. ©2017 AACR. ©2017 American Association for Cancer Research.

  11. Coexistence of EGFR with KRAS, or BRAF, or PIK3CA somatic mutations in lung cancer: a comprehensive mutation profiling from 5125 Chinese cohorts

    Science.gov (United States)

    Li, S; Li, L; Zhu, Y; Huang, C; Qin, Y; Liu, H; Ren-Heidenreich, L; Shi, B; Ren, H; Chu, X; Kang, J; Wang, W; Xu, J; Tang, K; Yang, H; Zheng, Y; He, J; Yu, G; Liang, N

    2014-01-01

    Background: Determining the somatic mutations of epidermal growth factor receptor (EGFR)-pathway networks is the key to effective treatment for non-small cell lung cancer (NSCLC) with tyrosine kinase inhibitors (TKIs).The somatic mutation frequencies and their association with gender, smoking history and histology was analysed and reported in this study. Methods: Five thousand one hundred and twenty-five NSCLC patients' pathology samples were collected, and EGFR, KRAS, BRAF and PIK3CA mutations were detected by multiplex testing. The mutation status of EGFR, KRAS, BRAF and PIK3CA and their association with gender, age, smoking history and histological type were evaluated by appropriate statistical analysis. Results: EGFR, KRAS, BRAF and PIK3CA mutation rates revealed 36.2%, 8.4%, 0.5% and 3.3%, respectively, across the 5125 pathology samples. For the first time, evidence of KRAS mutations were detected in two female, non-smoking patients, age 5 and 14, with NSCLC. Furthermore, we identified 153 double and coexisting mutations and 7 triple mutations. Interestingly, the second drug-resistant mutations, T790M or E545K, were found in 44 samples from patients who had never received TKI treatments. Conclusions: EGFR exons 19, 20 and 21, and BRAF mutations tend to happen in females and non-smokers, whereas KRAS mutations were more inclined to males and smokers. Activating and resistant mutations to EGFR-TKI drugs can coexist and ‘second drug-resistant mutations', T790M or E545K, may be primary mutations in some patients. These results will help oncologists to decide candidates for mutation testing and EGFR-TKI treatment. PMID:24743704

  12. Dacomitinib in lung cancer: a “lost generation” EGFR tyrosine-kinase inhibitor from a bygone era?

    Directory of Open Access Journals (Sweden)

    Ou SH

    2015-10-01

    Full Text Available Sai-Hong Ignatius Ou,1 Ross A Soo21Chao Family Comprehensive Cancer Center, Division of Hematology/Oncology, Department of Medicine, University of California, Irvine School of Medicine, Orange, CA, USA; 2National University Health System and Cancer Science Institute of Singapore, SingaporeAbstract: EGFR tyrosine-kinase inhibitors (TKIs have now been firmly established as the first-line treatment for non-small-cell lung cancer (NSCLC patients harboring activating EGFR mutations, based on seven prospective randomized Phase III trials. However, despite significantly improved overall response rate and improved median progression-free survival when compared to platinum-doublet chemotherapy, EGFR-mutant NSCLC patients treated with EGFR TKIs invariably progress due to the emergence of acquired resistances, with the gatekeeper T790M mutation accounting for up to 60% of the resistance mechanisms. Second-generation irreversible EGFR TKIs were developed in part to inhibit the T790M mutation, in addition to the common activating EGFR mutations. Dacomitinib is one such second-generation EGFR TKI designed to inhibit both the wild-type (WT EGFR and EGFR T790M. Afatinib is another second-generation EGR TKI that has been now been approved for the first-line treatment of EGFR-mutant NSCLC patients, while dacomitinib continues to undergo clinical evaluation. We will review the clinical development of dacomitinib from Phase I to Phase III trials, including the two recently published negative large-scale randomized Phase III trials (ARCHER 1009, NCIC-BR-26. Results from another large-scale randomized trial (ARCHER 1050 comparing dacomitinib to gefitinib as first-line treatment of advanced treatment-naïve EGFR-mutant NSCLC patients will soon be available and will serve as the lynchpin trial for the potential approval of dacomitinib in NSCLC. Meanwhile, third-generation EGFR TKIs (eg, CO-1686 [rociletinib], AZ9291, HM61713, EGF816, and ASP8273 that preferentially

  13. 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...... (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...... phosphorylation and activation of downstream signaling pathways. Importantly, EphA2 downregulation inhibits EGF-induced cancer cell migration and viability. The EGFR regulated EphA2 expression and functional cross-talk between the two receptor–ligand systems could be very important when targeting either receptor...

  14. Targeting EGFR in bilio-pancreatic and liver carcinoma.

    Science.gov (United States)

    Fratto, Maria Elisabetta; Santini, Daniele; Vincenzi, Bruno; Silvestris, Nicola; Azzariti, Amalia; Tommasi, Stefania; Zoccoli, Alice; Galluzzo, Sara; Maiello, Evaristo; Colucci, Giuseppe; Tonini, Giuseppe

    2011-01-01

    The key role of epidermal growth factor receptor(EGFR) in tumorigenesis has been demonstrated in several cancer types, so recent clinical trials have investigated their activity/efficacy in different settings. Two different types of EGFR-targeted agents were developed: monoclonal antibodies such as cetuximab and panitumumab, and tyrosine kinase inhibitors, such as gefitinib and erlotinib. In this review, we summarize the preclinical rational of potential activity and the most important clinical trials evaluated anti-EGFR targeted agents in non-colorectal digestive cancer, both in monotherapy and in combination with other chemotherapeutic or targeted agents. Patient selection by use of biologic markers will identify which patients are more likely to respond, contributing to the successful use of these agents.

  15. Enterococcus faecalis Enhances Cell Proliferation through Hydrogen Peroxide-Mediated Epidermal Growth Factor Receptor Activation

    Science.gov (United States)

    Boonanantanasarn, Kanitsak; Gill, Ann Lindley; Yap, YoonSing; Jayaprakash, Vijayvel; Sullivan, Maureen A.

    2012-01-01

    Enterococcus faecalis is a member of the intestinal and oral microbiota that may affect the etiology of colorectal and oral cancers. The mechanisms by which E. faecalis may contribute to the initiation and progression of these cancers remain uncertain. Epidermal growth factor receptor (EGFR) signaling is postulated to play a crucial role in oral carcinogenesis. A link between E. faecalis and EGFR signaling in oral cancer has not been elucidated. The present study aimed to evaluate the association between E. faecalis and oral cancer and to determine the underlying mechanisms that link E. faecalis to EGFR signaling. We report the high frequency of E. faecalis infection in oral tumors and the clinical association with EGFR activation. Using human oral cancer cells, we support the clinical findings and demonstrate that E. faecalis can induce EGFR activation and cell proliferation. E. faecalis activates EGFR through production of H2O2, a signaling molecule that activates several signaling pathways. Inhibitors of H2O2 (catalase) and EGFR (gefitinib) significantly blocked E. faecalis-induced EGFR activation and cell proliferation. Therefore, E. faecalis infection of oral tumor tissues suggests a possible association between E. faecalis infection and oral carcinogenesis. Interaction of E. faecalis with host cells and production of H2O2 increase EGFR activation, thereby contributing to cell proliferation. PMID:22851748

  16. Presence of the minor EGFR T790M mutation is associated with drug-sensitive EGFR mutations in lung adenocarcinoma patients.

    Science.gov (United States)

    Hashida, Shinsuke; Soh, Junichi; Toyooka, Shinichi; Tanaka, Tomoaki; Furukawa, Masashi; Shien, Kazuhiko; Yamamoto, Hiromasa; Asano, Hiroaki; Tsukuda, Kazunori; Hagiwara, Koichi; Miyoshi, Shinichiro

    2014-07-01

    The T790M mutation in the epidermal growth factor receptor (EGFR) gene is known to be associated with the acquired resistance of lung adenocarcinoma patients to EGFR-tyrosine kinase inhibitors (EGFR-TKIs). The minor T790M mutant allele is occasionally detected in EGFR-TKI-naive tumor samples, yet findings concerning the clinical impact of the minor T790M mutation vary among previous studies. In the present study, we assessed the clinical impact of the minor T790M mutation using a novel, highly sensitive assay combining high-resolution melting (HRM), mutant-enriched PCR and co-amplification at a lower denaturation temperature (COLD)-PCR. We determined the T790M mutational status in 146 surgically resected lung adenocarcinomas without a history of EGFR-TKI treatment using mutant-enriched COLD-HRM (MEC-HRM) and standard HRM assays. The sensitivities of the MEC-HRM and standard HRM assays for the detection of T790M-mutant alleles among wild-type alleles were 0.01 and 10%, respectively. Although the T790M mutation was not detected using a standard HRM assay, we identified 19 (13%) T790M mutations using the MEC-HRM assay and defined these 19 mutations as minor T790M mutations. The proportion of T790M alleles was mutation was significantly associated with the presence of EGFR exon 19 deletions or the L858R mutation (both of which are drug-sensitive EGFR mutations) (P=0.04). In conclusion, the minor EGFR T790M mutations were present in 13% of EGFR-TKI-naive surgically resected lung adenocarcinomas and were associated with drug-sensitive EGFR mutations.

  17. WASH and Tsg101/ALIX-dependent diversion of stress-internalized EGFR from the canonical endocytic pathway.

    Science.gov (United States)

    Tomas, Alejandra; Vaughan, Simon O; Burgoyne, Thomas; Sorkin, Alexander; Hartley, John A; Hochhauser, Daniel; Futter, Clare E

    2015-06-12

    Stress exposure triggers ligand-independent EGF receptor (EGFR) endocytosis, but its post-endocytic fate and role in regulating signalling are unclear. We show that the p38 MAP kinase-dependent, EGFR tyrosine kinase (TK)-independent EGFR internalization induced by ultraviolet light C (UVC) or the cancer therapeutic cisplatin, is followed by diversion from the canonical endocytic pathway. Instead of lysosomal degradation or plasma membrane recycling, EGFR accumulates in a subset of LBPA-rich perinuclear multivesicular bodies (MVBs) distinct from those carrying EGF-stimulated EGFR. Stress-internalized EGFR co-segregates with exogenously expressed pre-melanosomal markers OA1 and fibrillar PMEL, following early endosomal sorting by the actin polymerization-promoting WASH complex. Stress-internalized EGFR is retained intracellularly by continued p38 activity in a mechanism involving ubiquitin-independent, ESCRT/ALIX-dependent incorporation onto intraluminal vesicles (ILVs) of MVBs. In contrast to the internalization-independent EGF-stimulated activation, UVC/cisplatin-triggered EGFR activation depends on EGFR internalization and intracellular retention. EGFR signalling from this MVB subpopulation delays apoptosis and might contribute to chemoresistance.

  18. Clinical Observation of EGFR-TKI as A First-line Therapy on Advanced Non-small Cell Lung Cancer

    Directory of Open Access Journals (Sweden)

    Jianjie LI

    2012-05-01

    Full Text Available Background and objective It has been proven that epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI significantly benefits advanced non-small cell lung cancer (NSCLC patients harboring EGFR mutations in progression-free survival time with better tolerance. This study is undertaken to analyze efficacy and tolerance of advanced NSCLC patients harboring EGFR mutations taking EGFR-TKI as a first-line therapy. Methods Tumor samples from 54 patients with advanced NSCLC were examined for EGFR activating mutations (deletion mutation in exon 19 and the L858R point mutation in exon 21 by direct sequencing. The patients were first-line treated with oral administration of EGFR-TKI until disease progression. The efficacy and adverse events were observed, and survival was followed up. Results Among the patients, 61% (33 of 54 had EGFR exon 19 deletion, and 39% (21 of 54 had EGFR L858R point mutation. All patients received first-line TKI therapy. The total response rate was 96%, median progression free survival (PFS was 8.3 months and median survival was 19.5 months. The patients with EGFR exon 19 deletion had significantly longer median PFS (9 versus 7 months, P=0.002 and longer median overall survival (OS(25 versus 16 months, P=0.001 than patients with EGFR L858R point mutation. There is no significance in efficacy between gefitinib and erlotinib, and gefitinib is safer than erlotinib. The most common adverse events were rash and diarrhea. Two (4% grade 4 skin toxity effects, two (4% grade 3 aminotransferase level elevations, and one (1 grade 3 stomatitis were observed. Conclusion The first-line EGFR-TKI treatment in advanced NSCLC patients harboring EGFR mutations is efficient and safe, which is more efficient in patients with EGFR exon 19 deletion than those with EGFR L858R mutation.

  19. Detection and clinical significance of intratumoral EGFR mutational heterogeneity in Chinese patients with advanced non-small cell lung cancer.

    Directory of Open Access Journals (Sweden)

    Hua Bai

    Full Text Available PURPOSE: This study evaluated occurrence and potential clinical significance of intratumoral EGFR mutational heterogeneity in Chinese patients with non-small cell lung cancer (NSCLC. MATERIALS AND METHODS: Eighty-five stage IIIa-IV NSCLC patients who had undergone palliative surgical resection were included in this study. Of these, 45 patients carried EGFR mutations (group-M and 40 patients were wild-type (group-W. Each tumor sample was microdissected to yield 28-34 tumor foci and Intratumoral EGFR mutation were determined using Denaturing High Performance Liquid Chromatography (DHPLC and Amplification Refractory Mutation System (ARMS. EGFR copy numbers were measured using fluorescence in situ hybridization (FISH. RESULTS: Microdissection yielded 1,431 tumor foci from EGFR mutant patients (group-M and 1,238 foci from wild-type patients (group-W. The EGFR mutant frequencies in group-M were 80.6% (1,154/1,431 and 87.1% (1,247/1,431 using DHPLC and ARMS, respectively. A combination of EGFR-mutated and wild-type cells was detected in 32.9% (28/85 of samples by DHPLC and 28.2% (24/85 by ARMS, supporting the occurrence of intratumoral heterogeneity. Thirty-one patients (36.5% were identified as EGFR FISH-positive. Patients harboring intratumoral mutational heterogeneity possessed lower EGFR copy numbers than those tumors contained mutant cells alone (16.7% vs. 71.0%, P<0.05. Among 26 patients who had received EGFR-TKIs, the mean EGFR mutation content was higher in patients showing partial response (86.1% or stable disease (48.7% compared with patients experiencing progressive disease (6.0% (P = 0.001. There also showed relationship between progression-free survival (PFS and different content of EGFR mutation groups (pure wild type EGFR, EGFR mutation with heterogeneity and pure mutated EGFR (P = 0.001. CONCLUSION: Approximately 30% of patients presented intratumoral EGFR mutational heterogeneity, accompanying with relatively low EGFR copy

  20. COPI-mediated retrograde trafficking from the Golgi to the ER regulates EGFR nuclear transport

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Ying-Nai; Wang, Hongmei; Yamaguchi, Hirohito [Department of Molecular and Cellular Oncology, The University of Texas, M.D. Anderson Cancer Center, Houston, TX 77030 (United States); Lee, Hong-Jen; Lee, Heng-Huan [Department of Molecular and Cellular Oncology, The University of Texas, M.D. Anderson Cancer Center, Houston, TX 77030 (United States); The University of Texas Graduate School of Biomedical Sciences at Houston, Houston, TX 77030 (United States); Hung, Mien-Chie, E-mail: mhung@mdanderson.org [Department of Molecular and Cellular Oncology, The University of Texas, M.D. Anderson Cancer Center, Houston, TX 77030 (United States); The University of Texas Graduate School of Biomedical Sciences at Houston, Houston, TX 77030 (United States); Center for Molecular Medicine and Graduate Institute of Cancer Biology, China Medical University and Hospital, Taichung 404, Taiwan (China); Asia University, Taichung 413, Taiwan (China)

    2010-09-03

    Research highlights: {yields} ARF1 activation is involved in the EGFR transport to the ER and the nucleus. {yields} Assembly of {gamma}-COP coatomer mediates EGFR transport to the ER and the nucleus. {yields} Golgi-to-ER retrograde trafficking regulates nuclear transport of EGFR. -- Abstract: Emerging evidence indicates that cell surface receptors, such as the entire epidermal growth factor receptor (EGFR) family, have been shown to localize in the nucleus. A retrograde route from the Golgi to the endoplasmic reticulum (ER) is postulated to be involved in the EGFR trafficking to the nucleus; however, the molecular mechanism in this proposed model remains unexplored. Here, we demonstrate that membrane-embedded vesicular trafficking is involved in the nuclear transport of EGFR. Confocal immunofluorescence reveals that in response to EGF, a portion of EGFR redistributes to the Golgi and the ER, where its NH{sub 2}-terminus resides within the lumen of Golgi/ER and COOH-terminus is exposed to the cytoplasm. Blockage of the Golgi-to-ER retrograde trafficking by brefeldin A or dominant mutants of the small GTPase ADP-ribosylation factor, which both resulted in the disassembly of the coat protein complex I (COPI) coat to the Golgi, inhibit EGFR transport to the ER and the nucleus. We further find that EGF-dependent nuclear transport of EGFR is regulated by retrograde trafficking from the Golgi to the ER involving an association of EGFR with {gamma}-COP, one of the subunits of the COPI coatomer. Our findings experimentally provide a comprehensive pathway that nuclear transport of EGFR is regulated by COPI-mediated vesicular trafficking from the Golgi to the ER, and may serve as a general mechanism in regulating the nuclear transport of other cell surface receptors.

  1. EGFR or HER2 inhibition modulates the tumor microenvironment by suppression of PD-L1 and cytokines release.

    Science.gov (United States)

    Suh, Koung Jin; Sung, Ji Hea; Kim, Jin Won; Han, Song-Hee; Lee, Hye Seung; Min, Ahrum; Kang, Mi Hyun; Kim, Ji Eun; Kim, Ji-Won; Kim, Se Hyun; Lee, Jeong-Ok; Kim, Yu Jung; Lee, Keun-Wook; Kim, Jee Hyun; Bang, Soo-Mee; Im, Seock-Ah; Lee, Jong Seok

    2017-09-08

    Characteristics of tumor microenvironment have been suggested as predictive markers of anti-EGFR or anti-HER2 treatment response. However, the effect of EGFR/HER2 signal blockade on the tumor immune microenvironment is unclear. EGFR/HER2 pathway signaling and PD-L1 expression in gastric cancer cell lines were screened by western blot analysis. PD-L1 and HER2 expressions in 251 resected gastric tumors were determined by immunohistochemistry, and changes in EFGR, HER2, and PD-L1 expression in paired specimens between pre- and post-chemotherapy were evaluated. PD-L1 expression in HER2-amplified cell lines was evaluated by western blotting, fluorescence-activated cell sorting, reverse transcription, and real-time quantitative PCR analyses before and after afatinib, lapatinib, pictilisib and trametinib treatment. Changes in cytokines were evaluated by reverse transcription, real-time quantitative PCR, and enzyme-linked immunosorbent assay after EGFR/HER2 inhibition. Cell lines with pEGFR or pHER2 overexpression showed higher PD-L1 expression. In resected gastric tumors, HER2 expression was significantly associated with PD-L1 expression ( p =0.030). PD-L1 overexpression accompanied by increased HER2 expression was identified in a post-chemotherapy specimen from a patient with an initial HER2/PD-L1-negative tumor. In HER2-overexpressing cell lines, PD-L1 expression was decreased in a dose- and time-dependent manner after afatinib and lapatinib treatment. PI3K pathway inhibition by pictilisib, but not MEK pathway inhibition by trametinib, resulted in PD-L1 suppression. After lapatinib treatment, the release of CCL2, CCL21, VEGF and CXCL1 decreased in a dose-dependent manner. Inhibition of the EGFR/HER2 signaling pathway, particularly of downstream PI3K activity, suppressed PD-L1 and release of cytokines, suggesting that EGFR/HER2 inhibition may create a more favorable milieu for tumor immunotherapy.

  2. Quantification and kinetic analysis of Grb2-EGFR interaction on micro-patterned surfaces for the characterization of EGFR-modulating substances.

    Directory of Open Access Journals (Sweden)

    Peter Lanzerstorfer

    Full Text Available The identification of the epidermal growth factor receptor (EGFR as an oncogene has led to the development of several anticancer therapeutics directed against this receptor tyrosine kinase. However, drug resistance and low efficacy remain a severe challenge, and have led to a demand for novel systems for an efficient identification and characterization of new substances. Here we report on a technique which combines micro-patterned surfaces and total internal reflection fluorescence (TIRF microscopy (μ-patterning assay for the quantitative analysis of EGFR activity. It does not simply measure the phosphorylation of the receptor, but instead quantifies the interaction of the key signal transmitting protein Grb2 (growth factor receptor-bound protein 2 with the EGFR in a live cell context. It was possible to demonstrate an EGF dependent recruitment of Grb2 to the EGFR, which was significantly inhibited in the presence of clinically tested EGFR inhibitors, including small tyrosine kinase inhibitors and monoclonal antibodies targeting the EGF binding site. Importantly, in addition to its potential use as a screening tool, our experimental setup offers the possibility to provide insight into the molecular mechanisms of bait-prey interaction. Recruitment of the EGFR together with Grb2 to clathrin coated pits (CCPs was found to be a key feature in our assay. Application of bleaching experiments enabled calculation of the Grb2 exchange rate, which significantly changed upon stimulation or the presence of EGFR activity inhibiting drugs.

  3. EGFR-mediated Beclin 1 phosphorylation in autophagy suppression, tumor progression, and tumor chemoresistance

    National Research Council Canada - National Science Library

    Wei, Yongjie; Zou, Zhongju; Becker, Nils; Anderson, Matthew; Sumpter, Rhea; Xiao, Guanghua; Kinch, Lisa; Koduru, Prasad; Christudass, Christhunesa S; Veltri, Robert W; Grishin, Nick V; Peyton, Michael; Minna, John; Bhagat, Govind; Levine, Beth

    2013-01-01

    ...) tyrosine kinase regulates autophagy. Active EGFR binds the autophagy protein Beclin 1, leading to its multisite tyrosine phosphorylation, enhanced binding to inhibitors, and decreased Beclin 1-associated VPS34 kinase activity...

  4. Elevated BCRP/ABCG2 expression confers acquired resistance to gefitinib in wild-type EGFR-expressing cells.

    Directory of Open Access Journals (Sweden)

    Yun-Ju Chen

    Full Text Available BACKGROUND: The sensitivity of non-small cell lung cancer (NSCLC patients to EGFR tyrosine kinase inhibitors (TKIs is strongly associated with activating EGFR mutations. Although not as sensitive as patients harboring these mutations, some patients with wild-type EGFR (wtEGFR remain responsive to EGFR TKIs, suggesting that the existence of unexplored mechanisms renders most of wtEGFR-expressing cancer cells insensitive. METHODOLOGY/PRINCIPAL FINDINGS: Here, we show that acquired resistance of wtEGFR-expressing cancer cells to an EGFR TKI, gefitinib, is associated with elevated expression of breast cancer resistance protein (BCRP/ABCG2, which in turn leads to gefitinib efflux from cells. In addition, BCRP/ABCG2 expression correlates with poor response to gefitinib in both cancer cell lines and lung cancer patients with wtEGFR. Co-treatment with BCRP/ABCG2 inhibitors enhanced the anti-tumor activity of gefitinib. CONCLUSIONS/SIGNIFICANCE: Thus, BCRP/ABCG2 expression may be a predictor for poor efficacy of gefitinib treatment, and targeting BCRP/ABCG2 may broaden the use of gefitinib in patients with wtEGFR.

  5. UV light blocks EGFR signalling in human cancer cell lines

    DEFF Research Database (Denmark)

    Olsen, BB; Neves-Petersen, M T; Klitgaard, S

    2007-01-01

    overexpress the EGF receptor, leads to arrest of the EGFR signaling pathway. The phosphorylation status of the receptor and the level of phosphorylated downstream signaling molecules i.e. AKT and the mitogen activated protein kinases (MAPKs) ERK1 and 2 is detected by Western blotting using phosphospecific...

  6. Epidermal Growth Factor Receptor (EGFR gene copy number (GCN correlates with clinical activity of irinotecan-cetuximab in K-RAS wild-type colorectal cancer: a fluorescence in situ (FISH and chromogenic in situ hybridization (CISH analysis

    Directory of Open Access Journals (Sweden)

    Scartozzi Mario

    2009-08-01

    Full Text Available Abstract Background K-RAS wild type colorectal tumors show an improved response rate to anti-EGFR monoclonal antibodies. Nevertheless 70% to 40% of these patients still does not seem to benefit from this therapeutic approach. FISH EGFR GCN has been previously demonstrated to correlate with clinical outcome of colorectal cancer treated with anti-EGFR monoclonal antibodies. CISH also seemed able to provide accurate EGFR GCN information with the advantage of a simpler and reproducible technique involving immunohistochemistry and light microscopy. Based on these findings we investigated the correlation between both FISH and CISH EGFR GCN and clinical outcome in K-RAS wild-type colorectal cancer treated with irinotecan-cetuximab. Methods Patients with advanced K-RAS wild-type, colorectal cancer receiving irinotecan-cetuximab after failure of irinotecan-based chemotherapy were eligible. A cut-off value for EGFR GCN of 2.6 and 2.12 for FISH and CISH respectively was derived from ROC curve analysis. Results Forty-four patients were available for analysis. We observed a partial remission in 9 (60% and 2 (9% cases with a FISH EGFR GCN ≥ 2.6 and Conclusion FISH and CISH EGFR GCN may both represent effective tools for a further patients selection in K-RAS wild-type colorectal cancer treated with cetuximab.

  7. Psychological determinants of information searching activity.

    Science.gov (United States)

    Gorunova, L

    2012-01-01

    The paper deals with the application of the activity theory in describing psychological determinants of the information searching activity. The notions of information behavior, information retrieval, information competence, information retrieval activity given in Russian and English scientific literature are compared. The research approach to the information retrieval activity based on the principles developed in the Russian theory of activity is described; and the fundamentals of G. Sukhodolsky's generalized conception of activity are presented for the first time. Analysis of empirical researches showed that specific features of information search depend on how the user evaluates information resources, information, conditions and results of search. Psychological determiners of information search may be detected as the system of evaluative alternatives, which is generated by the user during the process of his experience growth. We discovered that user's evaluation system is also related to his individual typological and personal regulative features and determines the choice of the search strategy.

  8. Comparison of the Analytical Performance Between cobas EGFR Assay and PCR-Clamp Method in the Detection of EGFR Mutations in Japanese Non-Small Cell Lung Cancer Patients.

    Science.gov (United States)

    Ai, Tomohiko; Yuri, Maiko; Tabe, Yoko; Kakimoto, Atsushi; Morishita, Soji; Tsuchiya, Koji; Takamochi, Kazuya; Kodama, Yuzo; Takahashi, Fumiyuki; Shigeki, Misawa; Horii, Takashi; Suzuki, Kenji; Takahashi, Kazuhisa; Miida, Takashi; Ohsaka, Akimichi

    2017-05-01

    EGFR, a tyrosine-kinase, plays an important role in the progression of lung cancer. Since genetic abnormality of EGFR alters the effects of tyrosine-kinase inhibitors targeting EGFR, molecular analyses of EGFR have recently gained more attention in the treatment of lung cancer. However, several different techniques are available and which method is superior has not been determined. In this study, we compared two recently developed PCR-based techniques, PCR-clamp method and cobas EGFR assay. Ninety-four surgical samples and 58 biopsy samples from patients suffering from non-small cell lung cancers (NSCLCs) were included in the study. Samples with positive and negative genetic abnormalities, 66 and 28 respectively, were chosen for PCR-Clamp methods. Those same samples were reanalyzed with cobas EGFR assay. The concordance between PCR-Clamp and cobas EGFR methods was 95.7%. PCR-Clamp failed to detect four mutations that were detected with cobas EGFR assay. These two methods were further tested by analyzing 58 random biopsy samples. The concordance for the biopsy samples was 93.1%, and PCR-Clamp, again, failed to detect three mutations that were detected with cobas EGFR assay. Our results showed both methods detected most of the known EGFR mutations and the concordance was similar to those previously reported in different ethnicities. However, in our study, PCR-Clamp method failed to detect a total of seven mutations that were detected with cobas EGFR assay. Thus, we concluded that cobas EGFR assay is an easier and more accurate screening assay than PCR-Clamp method in detecting EGFR genetic abnormalities.

  9. A Chimeric Egfr Protein Reporter Mouse Reveals Egfr Localization and Trafficking In Vivo

    Directory of Open Access Journals (Sweden)

    Yu-Ping Yang

    2017-05-01

    Full Text Available EGF receptor (EGFR is a critical signaling node throughout life. However, it has not been possible to directly visualize endogenous Egfr in mice. Using CRISPR/Cas9 genome editing, we appended a fluorescent reporter to the C terminus of the Egfr. Homozygous reporter mice appear normal and EGFR signaling is intact in vitro and in vivo. We detect distinct patterns of Egfr expression in progenitor and differentiated compartments in embryonic and adult mice. Systemic delivery of EGF or amphiregulin results in markedly different patterns of Egfr internalization and trafficking in hepatocytes. In the normal intestine, Egfr localizes to the crypt rather than villus compartment, expression is higher in adjacent epithelium than in intestinal tumors, and following colonic injury expression appears in distinct cell populations in the stroma. This reporter, under control of its endogenous regulatory elements, enables in vivo monitoring of the dynamics of Egfr localization and trafficking in normal and disease states.

  10. Pooled analysis of clinical outcome for EGFR TKI-treated patients with EGFR mutation-positive NSCLC

    Science.gov (United States)

    Paz-Ares, Luis; Soulières, Denis; Moecks, Joachim; Bara, Ilze; Mok, Tony; Klughammer, Barbara

    2014-01-01

    Patients with non-small-cell lung cancer (NSCLC) appear to gain particular benefit from treatment with epidermal growth factor receptor (EGFR) tyrosine-kinase inhibitors (TKI) if their disease tests positive for EGFR activating mutations. Recently, several large, controlled, phase III studies have been published in NSCLC patients with EGFR mutation-positive tumours. Given the increased patient dataset now available, a comprehensive literature search for EGFR TKIs or chemotherapy in EGFR mutation-positive NSCLC was undertaken to update the results of a previously published pooled analysis. Pooling eligible progression-free survival (PFS) data from 27 erlotinib studies (n = 731), 54 gefitinib studies (n = 1802) and 20 chemotherapy studies (n = 984) provided median PFS values for each treatment. The pooled median PFS was: 12.4 months (95% accuracy intervals [AI] 11.6–13.4) for erlotinib-treated patients; 9.4 months (95% AI 9.0–9.8) for gefitinib-treated patients; and 5.6 months (95% AI 5.3–6.0) for chemotherapy. Both erlotinib and gefitinib resulted in significantly longer PFS than chemotherapy (permutation testing; P = 0.000 and P = 0.000, respectively). Data on more recent TKIs (afatinib, dacomitinib and icotinib) were insufficient at this time-point to carry out a pooled PFS analysis on these compounds. The results of this updated pooled analysis suggest a substantial clear PFS benefit of treating patients with EGFR mutation-positive NSCLC with erlotinib or gefitinib compared with chemotherapy. PMID:25100284

  11. EGFR testing and clinical management of advanced NSCLC: a Galician Lung Cancer Group study (GGCP 048-10).

    Science.gov (United States)

    Vázquez, Sergio; Casal, Joaquín; Afonso Afonso, Francisco Javier; Fírvida, José Luis; Santomé, Lucía; Barón, Francisco; Lázaro, Martín; Pena, Carolina; Amenedo, Margarita; Abdulkader, Ihab; González-Arenas, Carmen; Fachal, Laura; Vega, Ana

    2016-01-01

    This study aimed to assess the incidence of mutations in the epidermal growth factor receptor (EGFR) gene in non-small-cell lung cancer (NSCLC) patients in the Galician region of Spain and the clinical management and outcome of patients carrying EGFR mutations. All newly diagnosed advanced or metastatic NSCLC patients were screened for EGFR mutations in matched tumor samples (tissue or cytology specimens) and serum samples. Of 198 patients screened for EGFR mutations in tumor samples, 184 had evaluable data and, of these, 25 (13.6%) had EGFR mutations (84% sensitizing mutations). EGFR mutation was found in serum in 14 (8.1%) patients (of 174 evaluable). Compared to matched tumor tissue, serum EGFR mutation testing specificity and sensitivity were 99% and 52%, respectively. All but two patients received gefitinib. Median progression-free survival and overall survival were 10 (95% confidence interval: 4.8-15.3) months and 17.8 (95% confidence interval: 13.9-21.6) months, respectively, in patients carrying sensitizing mutations. The incidence of EGFR mutations in Galicia is consistent with previous data in Spain. Our results also support the feasibility of EGFR testing to guide treatment decision making using tumor tissue or cytology samples, or serum samples if tumor specimens are unavailable. These findings also confirm that first-line gefitinib is an active treatment option in Caucasians with EGFR mutation-positive NSCLC.

  12. High levels of EGFR expression in tumor stroma are associated with aggressive clinical features in epithelial ovarian cancer.

    Science.gov (United States)

    Wang, Ke; Li, Dan; Sun, Lu

    2016-01-01

    The aim of this study was to investigate the clinical significance and biological function of epidermal growth factor receptor (EGFR) expressed in tumor stroma of epithelial ovarian cancer. Immunohistological staining of EGFR was evaluated in 242 patients with epithelial ovarian cancer. The correlations of EGFR expression in tumor stroma with clinicopathological features and with the expression level of Ki-67 were analyzed by SPSS software. Kaplan-Meier analysis and the Cox proportional hazard model were used to analyze the effect of EGFR expression in tumor stroma on the prognosis of patients with epithelial ovarian cancer. Meanwhile, the activities of proliferation and migration of tumor cells were detected when EGFR overexpressed in stroma cells. EGFR expression in tumor stroma correlated significantly with clinical stage (χ (2)=7.002, P=0.008) and distant metastases (χ (2)=16.59, Pstroma and the level of Ki-67 expressed in tumor cells (χ (2)=6.120, P=0.013). Patients with high EGFR expression level in tumor stroma showed poor survival (P=0.002). Multivariate analysis showed that high expression of EGFR in tumor stroma was an independent predictor for epithelial ovarian cancer patients (hazard ratio =1.703; 95% confidence interval 1.125-2.578, P=0.012). Furthermore, stroma cells overexpressing EGFR could promote the proliferation and migration of adjacent tumor cells. High expression of EGFR in tumor stroma correlates with aggressive clinical features in epithelial ovarian cancer, and is an independent prognostic factor.

  13. RAB-7 antagonizes LET-23 EGFR signaling during vulva development in Caenorhabditis elegans.

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    Olga Skorobogata

    Full Text Available The Rab7 GTPase regulates late endosome trafficking of the Epidermal Growth Factor Receptor (EGFR to the lysosome for degradation. However, less is known about how Rab7 activity, functioning late in the endocytic pathway, affects EGFR signaling. Here we used Caenorhabditis elegans vulva cell fate induction, a paradigm for genetic analysis of EGFR/Receptor Tyrosine Kinase (RTK signaling, to assess the genetic requirements for rab-7. Using a rab-7 deletion mutant, we demonstrate that rab-7 antagonizes LET-23 EGFR signaling to a similar extent, but in a distinct manner, as previously described negative regulators such as sli-1 c-Cbl. Epistasis analysis places rab-7 upstream of or in parallel to lin-3 EGF and let-23 EGFR. However, expression of gfp::rab-7 in the Vulva Presursor Cells (VPCs is sufficient to rescue the rab-7(- VPC induction phenotypes indicating that RAB-7 functions in the signal receiving cell. We show that components of the Endosomal Sorting Complex Required for Transport (ESCRT-0, and -I, complexes, hgrs-1 Hrs, and vps-28, also antagonize signaling, suggesting that LET-23 EGFR likely transits through Multivesicular Bodies (MVBs en route to the lysosome. Consistent with RAB-7 regulating LET-23 EGFR trafficking, rab-7 mutants have increased number of LET-23::GFP-positive endosomes. Our data imply that Rab7, by mediating EGFR trafficking and degradation, plays an important role in downregulation of EGFR signaling. Failure to downregulate EGFR signaling contributes to oncogenesis, and thus Rab7 could possess tumor suppressor activity in humans.

  14. 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.)

  15. Reversing EGFR Mediated Immunoescape by Targeted Monoclonal Antibody Therapy

    Directory of Open Access Journals (Sweden)

    Fernando Concha-Benavente

    2017-05-01

    Full Text Available Uncontrolled growth is a signature of carcinogenesis, in part mediated by overexpression or overstimulation of growth factor receptors. The epidermal growth factor receptor (EGFR mediates activation of multiple oncogenic signaling pathways and escape from recognition by the host immune system. We discuss how EGFR signaling downregulates tumor antigen presentation, upregulates suppressive checkpoint receptor ligand programmed death ligand (PD-L1, induces secretion of inhibitory molecules such as transforming growth factor beta (TGFβ and reprograms the metabolic pathways in cancer cells to upregulate aerobic glycolysis and lactate secretion that ultimately lead to impaired cellular immunity mediated by natural killer (NK cell and cytotoxic T lymphocytes (CTL. Ultimately, our understanding of EGFR-mediated escape mechanisms has led us to design EGFR-specific monoclonal antibody therapies that not only inhibit tumor cell metabolic changes and intrinsic oncogenic signaling but also activates immune cells that mediate tumor clearance. Importantly, targeted immunotherapy may also benefit from combination with antibodies that target other immunosuppressive pathways such PD-L1 or TGFβ and ultimately enhance clinical efficacy.

  16. EGFR CA repeat polymorphism predict clinical outcome in EGFR mutation positive NSCLC patients treated with erlotinib

    DEFF Research Database (Denmark)

    Winther Larsen, Anne; Nissen, Peter Henrik; Meldgaard, Peter

    2014-01-01

    OBJECTIVES: Somatic mutations in the epidermal growth factor receptor (EGFR) are predictors of efficacy for treatment with the EGFR tyrosine kinase inhibitor erlotinib in non-small cell lung cancer (NSCLC). A CA repeat polymorphism in intron 1 of the EGFR gene influences the transcription...

  17. Determination of proteolytic activity in cereals

    Directory of Open Access Journals (Sweden)

    D. Wojciechowska

    2015-01-01

    Full Text Available Results have been presented indicating that native proteolytic enzymes and bromelain acted variously ion wheat proteins differentiated in quality, they also act nonspecifically ton haemoglobin. It was thought useful to elaborate a new method of proteolytic activity determination based on the application of a standard natural substrate. The latter consists of gluten extract in acetic acid from a definite flour sample. The method of substrate selection and the determination procedure are described and some examples of wheat proteolytic activity determination are given.

  18. Molecular determinants of epidermal growth factor binding: a molecular dynamics study.

    Directory of Open Access Journals (Sweden)

    Jeffrey M Sanders

    Full Text Available The epidermal growth factor receptor (EGFR is a member of the receptor tyrosine kinase family that plays a role in multiple cellular processes. Activation of EGFR requires binding of a ligand on the extracellular domain to promote conformational changes leading to dimerization and transphosphorylation of intracellular kinase domains. Seven ligands are known to bind EGFR with affinities ranging from sub-nanomolar to near micromolar dissociation constants. In the case of EGFR, distinct conformational states assumed upon binding a ligand is thought to be a determining factor in activation of a downstream signaling network. Previous biochemical studies suggest the existence of both low affinity and high affinity EGFR ligands. While these studies have identified functional effects of ligand binding, high-resolution structural data are lacking. To gain a better understanding of the molecular basis of EGFR binding affinities, we docked each EGFR ligand to the putative active state extracellular domain dimer and 25.0 ns molecular dynamics simulations were performed. MM-PBSA/GBSA are efficient computational approaches to approximate free energies of protein-protein interactions and decompose the free energy at the amino acid level. We applied these methods to the last 6.0 ns of each ligand-receptor simulation. MM-PBSA calculations were able to successfully rank all seven of the EGFR ligands based on the two affinity classes: EGF>HB-EGF>TGF-α>BTC>EPR>EPG>AR. Results from energy decomposition identified several interactions that are common among binding ligands. These findings reveal that while several residues are conserved among the EGFR ligand family, no single set of residues determines the affinity class. Instead we found heterogeneous sets of interactions that were driven primarily by electrostatic and Van der Waals forces. These results not only illustrate the complexity of EGFR dynamics but also pave the way for structure-based design of

  19. EGFR Inhibition Abrogates Leiomyosarcoma Cell Chemoresistance through Inactivation of Survival Pathways and Impairment of CSC Potential

    Science.gov (United States)

    Sette, Giovanni; Salvati, Valentina; Memeo, Lorenzo; Fecchi, Katia; Colarossi, Cristina; Di Matteo, Paola; Signore, Michele; Biffoni, Mauro; D’Andrea, Vito; De Antoni, Enrico; Canzonieri, Vincenzo; De Maria, Ruggero; Eramo, Adriana

    2012-01-01

    Background Tumor cells with stem-like phenotype and properties, known as cancer stem cells (CSC), have been identified in most solid tumors and are presumed to be responsible for driving tumor initiation, chemoresistance, relapse, or metastasis. A subpopulation of cells with increased stem-like potential has also been identified within sarcomas. These cells are endowed with increased tumorigenic potential, chemoresistance, expression of embryonic markers, and side population(SP) phenotype. Leiomyosarcomas (LMS) are soft tissue sarcomas presumably arising from undifferentiated cells of mesenchymal origin, the Mesenchymal Stem Cells (MSC). Frequent recurrence of LMS and chemoresistance of relapsed patients may likely result from the failure to target CSC. Therefore, therapeutic cues coming from the cancer stem cell (CSC) field may drastically improve patient outcome. Methodology/Principal Findings We expanded LMS stem-like cells from patient samples in vitro and examined the possibility to counteract LMS malignancy through a stem-like cell effective approach. LMS stem-like cells were in vitro expanded both as “tumor spheres” and as “monolayers” in Mesenchymal Stem Cell (MSC) conditions. LMS stem-like cells displayed MSC phenotype, higher SP fraction, and increased drug-extrusion, extended proliferation potential, self-renewal, and multiple differentiation ability. They were chemoresistant, highly tumorigenic, and faithfully reproduced the patient tumor in mice. Such cells displayed activation of EGFR/AKT/MAPK pathways, suggesting a possibility in overcoming their chemoresistance through EGFR blockade. IRESSA plus Vincristine treatment determined pathway inactivation, impairment of SP phenotype, high cytotoxicity in vitro and strong antitumor activity in stem-like cell-generated patient-like xenografts, targeting both stem-like and differentiated cells. Conclusions/Significance EGFR blockade combined with vincristine determines stem-like cell effective

  20. Third-generation inhibitors targeting EGFR T790M mutation in advanced non-small cell lung cancer

    Directory of Open Access Journals (Sweden)

    Shuhang Wang

    2016-04-01

    Full Text Available Abstract The tyrosine kinase inhibitors (TKI against epidermal growth factor receptor (EGFR are widely used in patients with non-small cell lung cancer (NSCLC. However, EGFR T790M mutation leads to resistance to most clinically available EGFR TKIs. Third-generation EGFR TKIs against the T790M mutation have been in active clinical development. These agents include osimertinib, rociletinib, HM61713, ASP8273, EGF816, and PF-06747775. Osimertinib and rociletinib have shown clinical efficacy in phase I/II trials in patients who had acquired resistance to first- or second-generation TKIs. Osimertinib (AZD9291, TAGRISSO was recently approved by FDA for metastatic EGFR T790M mutation-positive NSCLC. HM61713, ASP8237, EGF816, and PF-06747775 are still in early clinical development. This article reviews the emerging data regarding third-generation agents against EGFR T790M mutation in the treatment of patients with advanced NSCLC.

  1. Using the MCF10A/MCF10CA1a Breast Cancer Progression Cell Line Model to Investigate the Effect of Active, Mutant Forms of EGFR in Breast Cancer Development and Treatment Using Gefitinib.

    Directory of Open Access Journals (Sweden)

    Darrell C Bessette

    Full Text Available Basal-like and triple negative breast cancer (TNBC share common molecular features, poor prognosis and a propensity for metastasis to the brain. Amplification of epidermal growth factor receptor (EGFR occurs in ~50% of basal-like breast cancer, and mutations in the epidermal growth factor receptor (EGFR have been reported in up to ~ 10% of Asian TNBC patients. In non-small cell lung cancer several different mutations in the EGFR tyrosine kinase domain confer sensitivity to receptor tyrosine kinase inhibitors, but the tumourigenic potential of EGFR mutations in breast cells and their potential for targeted therapy is unknown.Constructs containing wild type, G719S or E746-A750 deletion mutant forms of EGFR were transfected into the MCF10A breast cells and their tumorigenic derivative, MCF10CA1a. The effects of EGFR over-expression and mutation on proliferation, migration, invasion, response to gefitinib, and tumour formation in vivo was investigated. Copy number analysis and whole exome sequencing of the MCF10A and MCF10CA1a cell lines were also performed.Mutant EGFR increased MCF10A and MCF10CA1a proliferation and MCF10A gefitinib sensitivity. The EGFR-E746-A750 deletion increased MCF10CA1a cell migration and invasion, and greatly increased MCF10CA1a xenograft tumour formation and growth. Compared to MCF10A cells, MCF10CA1a cells exhibited large regions of gain on chromosomes 3 and 9, deletion on chromosome 7, and mutations in many genes implicated in cancer.Mutant EGFR enhances the oncogenic properties of MCF10A cell line, and increases sensitivity to gefitinib. Although the addition of EGFR E746-A750 renders the MCF10CA1a cells more tumourigenic in vivo it is not accompanied by increased gefitinib sensitivity, perhaps due to additional mutations, including the PIK3CA H1047R mutation, that the MCF10CA1a cell line has acquired. Screening TNBC/basal-like breast cancer for EGFR mutations may prove useful for directing therapy but, as in non

  2. Association Between Environmental Tobacco Smoke Exposure and the Occurrence of EGFR Mutations and ALK Rearrangements in Never-smokers With Non-Small-cell Lung Cancer: Analyses From a Prospective Multinational ETS Registry.

    Science.gov (United States)

    Soo, Ross A; Kubo, Akihito; Ando, Masahiko; Kawaguchi, Tomoya; Ahn, Myung-Ju; Ou, Sai-Hong Ignatius

    2017-09-01

    Molecular studies have demonstrated actionable driver oncogene alterations are more frequent in never-smokers with non-small-cell lung cancer (NSCLC). The etiology of these driver oncogenes in patients with NSCLC remains unknown, and environmental tobacco smoke (ETS) is a potential cause in these cases. We assembled clinical and genetic information for never-smoker patients with NSCLC accrued in Japan, Korea, Singapore, and the United States. To determine an association between cumulative ETS and activating EGFR mutations or ALK rearrangements, the Mantel extension test was used. Multivariate analysis on activating EGFR and ALK gene rearrangements was performed using the generalized linear mixed model with nations as a random effect. From July 2007 to December 2012, 498 never-smokers with pathologically proven NSCLC were registered and tested for the association between ETS and EGFR and ALK status. EGFR mutations were more frequent in the ever-ETS cohort (58.4%) compared with the never-ETS cohort (39.6%), and the incidence of EGFR mutations was significantly associated with the increment of cumulative ETS (cETS) in female never-smokers (P = .033), whereas the incidence of ALK rearrangements was not significantly different between the ever-ETS and never-ETS cohorts. Odds ratio for EGFR mutations for each 10-year increment in cETS was 1.091 and 0.89 for female and male never-smokers (P = .031 and P = .263, respectively). Increased ETS exposure was closely associated with EGFR mutations in female never-smokers with NSCLC in the expanded multinational cohort. However, the association of ETS and ALK rearrangements in never-smokers with NSCLC was not significant. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. Cationic Polyamidoamine Dendrimers as Modulators of EGFR Signaling In Vitro and In Vivo

    Science.gov (United States)

    Akhtar, Saghir; Al-Zaid, Bashayer; El-Hashim, Ahmed Z.; Chandrasekhar, Bindu; Attur, Sreeja; Yousif, Mariam H. M.; Benter, Ibrahim F.

    2015-01-01

    Cationic polyamidoamine (PAMAM) dendrimers are branch-like spherical polymers being investigated for a variety of applications in nanomedicine including nucleic acid drug delivery. Emerging evidence suggests they exhibit intrinsic biological and toxicological effects but little is known of their interactions with signal transduction pathways. We previously showed that the activated (fragmented) generation (G) 6 PAMAM dendrimer, Superfect (SF), stimulated epidermal growth factor receptor (EGFR) tyrosine kinase signaling—an important signaling cascade that regulates cell growth, survival and apoptosis- in cultured human embryonic kidney (HEK 293) cells. Here, we firstly studied the in vitro effects of Polyfect (PF), a non-activated (intact) G6 PAMAM dendrimer, on EGFR tyrosine kinase signaling via extracellular-regulated kinase 1/2 (ERK1/2) and p38 mitogen-activated protein kinase (MAPK) in cultured HEK 293 cells and then compared the in vivo effects of a single administration (10mg/kg i.p) of PF or SF on EGFR signaling in the kidneys of normal and diabetic male Wistar rats. Polyfect exhibited a dose- and time-dependent inhibition of EGFR, ERK1/2 and p38 MAPK phosphorylation in HEK-293 cells similar to AG1478, a selective EGFR inhibitor. Administration of dendrimers to non-diabetic or diabetic animals for 24h showed that PF inhibited whereas SF stimulated EGFR phosphorylation in the kidneys of both sets of animals. PF-mediated inhibition of EGFR phosphorylation as well as SF or PF-mediated apoptosis in HEK 293 cells could be significantly reversed by co-treatment with antioxidants such as tempol implying that both these effects involved an oxidative stress-dependent mechanism. These results show for the first time that SF and PF PAMAM dendrimers can differentially modulate the important EGFR signal transduction pathway in vivo and may represent a novel class of EGFR modulators. These findings could have important clinical implications for the use of PAMAM

  4. Sociocultural determiners of scientific activity transformation

    Directory of Open Access Journals (Sweden)

    Rubanov Vitaliy

    2016-01-01

    Full Text Available Transformation of modern society affects all fields. The goals and objectives of social development as well as the means to achieve them require science-based mechanisms, methodological support for studying social phenomena and their philosophical and sociological analysis. Both integrative and differential processes characterize modern scientific activity. The key reason for science institutionalization as a sociocultural phenomenon is its social inclusion. In this process science integrates with such social institutions as education, management and etc.The paper deals with research activities in higher education institutions. The importance of this study is determined by the increasing role of research activities in social, economic, political, legal and cultural development of society. In a modern society the process of institutionalization requires its dynamic development. Science has issues that should be examined. The socio-cultural basis of scientific activity changes is a key one for studying. The goal of this study is to analyze the historical validity of the characteristics of research activities in terms of sociocultural determinants. The authors carried out system and comparative analyses and a logical-historical study of the transformation of research activity phenomenon. In conclusion, sociocultural determinants of research activity formation and development are revealed in today’s changing conditions of social factors; the definitions to such concepts as “research interest” and “research needs” are given.

  5. Determination of phospholipase activity of PAF acetylhydrolase.

    Science.gov (United States)

    Stafforini, Diana M; McIntyre, Thomas M

    2013-06-01

    This article presents a radiometric assay to determine the enzymatic activity of platelet-activating factor (PAF) acetylhydrolase (PAF-AH), also known as lipoprotein-associated phospholipase A2 and phospholipase A2 group 7A. The method is based on the release of radioactively labeled acetate from sn-2-labeled PAF and separation of substrate and product using reversed-phase column chromatography on octadecyl silica gel cartridges. The assay is fast, convenient, reproducible, sensitive, and inexpensive. The instrumentation required includes standard laboratory equipment and a liquid scintillation counter. The assay is also useful to determine the activity of intracellular PAF-AH (PAF-AH II), provided that a few modifications are included. The enzymatic activity determined using PAF as the substrate is a direct indication of the ability of plasma samples, purified preparations, and cellular and tissue lysates to hydrolyze short- and medium-chain phospholipids that may or may not harbor oxidized functionalities. In addition, the assay can be used to test the suitability of other phospholipids, including species containing oxidized, long-chain sn-2 fatty acyl groups, as PAF-AH substrates. This versatile assay can be used to accurately determine PAF-AH activity in biological samples and preliminarily assess affinity and efficiency of the hydrolysis of potential substrates present in complex mixtures. Copyright © 2012 Elsevier Inc. All rights reserved.

  6. High levels of EGFR expression in tumor stroma are associated with aggressive clinical features in epithelial ovarian cancer

    Directory of Open Access Journals (Sweden)

    Wang K

    2016-01-01

    Full Text Available Ke Wang, Dan Li, Lu Sun Department of Gynecologic Cancer, National Clinical Research Center for Cancer, Tianjin Key Laboratory of Cancer Prevention and Therapy, Tianjin Medical University Cancer Institute and Hospital, Tianjin, People’s Republic of China Purpose: The aim of this study was to investigate the clinical significance and biological function of epidermal growth factor receptor (EGFR expressed in tumor stroma of epithelial ovarian cancer. Methods: Immunohistological staining of EGFR was evaluated in 242 patients with epithelial ovarian cancer. The correlations of EGFR expression in tumor stroma with clinicopathological features and with the expression level of Ki-67 were analyzed by SPSS software. Kaplan–Meier analysis and the Cox proportional hazard model were used to analyze the effect of EGFR expression in tumor stroma on the prognosis of patients with epithelial ovarian cancer. Meanwhile, the activities of proliferation and migration of tumor cells were detected when EGFR overexpressed in stroma cells. Results: EGFR expression in tumor stroma correlated significantly with clinical stage (χ2=7.002, P=0.008 and distant metastases (χ2=16.59, P<0.001. Furthermore, there was a significantly positive correlation between the level of EGFR expressed in tumor stroma and the level of Ki-67 expressed in tumor cells (χ2=6.120, P=0.013. Patients with high EGFR expression level in tumor stroma showed poor survival (P=0.002. Multivariate analysis showed that high expression of EGFR in tumor stroma was an independent predictor for epithelial ovarian cancer patients (hazard ratio =1.703; 95% confidence interval 1.125–2.578, P=0.012. Furthermore, stroma cells overexpressing EGFR could promote the proliferation and migration of adjacent tumor cells. Conclusion: High expression of EGFR in tumor stroma correlates with aggressive clinical features in epithelial ovarian cancer, and is an independent prognostic factor. Keywords: EGFR, epithelial

  7. Combination of BIBW2992 and ARQ 197 is effective against erlotinib-resistant human lung cancer cells with the EGFR T790M mutation.

    Science.gov (United States)

    Qu, Geping; Liu, Changting; Sun, Baojun; Zhou, Changxi; Zhang, Zhijian; Wang, Peng

    2014-07-01

    Although the EGFR tyrosine kinase inhibitors (EGFR-TKI) erlotinib and gefitinib have shown marked effects against EGFR-mutated lung cancer, patients acquire resistance by various mechanisms, including the EGFR T790M mutation and Met induction, consequently suffering relapse. Thus, novel agents to overcome EGFR-TKI resistance are urgently needed. We aimed to investigate the inhibitory effects of a combination of BIBW2992 (irreversible EGFR inhibitor)/ARQ 197 (MET inhibitor) on the human lung adenocarcinoma cell line H1975. H1975 cells (harboring a T790M mutation in EGFR) were treated with erlotinib, BIBW2992 or ARQ 197 separately or with combinations of erlotinib/ARQ 197 or BIBW2992/ARQ 197. Cell growth, apoptosis and cell cycle distribution were evaluated by MTT assay, Annexin V/propidium iodide (PI) double staining and flow cytometry, respectively. EGFR, MET, AKT, ERK and the respective phosphorylated counterparts were detected by western blot analysis. Pathway-specific knockdown of MET and/or EGFR kinase signaling was achieved by siRNA interference. H1975 cells displayed EGFR and MET activation, and were resistant to erlotinib. The BIBW2992/ARQ 197 combination significantly inhibited growth, induced cell cycle arrest and apoptosis, and altered the phosphorylation of EGFR, MET, AKT and ERK1/2 in the H1975 cells. Phosphorylation of AKT and ERK1/2, downstream effectors of the EGFR and MET pathways, was not affected by the other tested treatments. Finally, knockdown of MET and/or EGFR in the H1975 cells confirmed the enhanced downstream inhibition of both MET and EGFR pathways. Combination of an irreversible EGFR inhibitor and MET inhibitor is effective in controlling H1975 cells with acquired resistance to erlotinib, by a mechanism involving the downregulation of PI3K/AKT and MEK/ERK signaling pathways.

  8. Anti-EGFR monoclonal antibody in cancer treatment: in vitro and in vivo evidence

    Science.gov (United States)

    Quatrale, Anna Elisa; Petriella, Daniela; Porcelli, Letizia; Tommasi, Stefania; Silvestris, Nicola; Colucci, Giuseppe; Angelo, Angelo; Azzariti, Amalia

    2011-01-01

    The complexity of EGFR signaling network suggests that the receptor could be promising targets for new personalised therapy. In clinical practice two strategies targeting the receptor are available; they utilise monoclonal antibodies, directed towards the extracellular domain of EGFR, and small molecule tyrosine kinase inhibitors, which bind the catalytic kinase domain of the receptor. In this review, we summarise currently known pre-clinical data on the antitumor effects of monoclonal antibodies, which bind to EGFR in its inactive configuration, competing for ligand binding and thereby blocking ligand-induced EGFR tyrosine kinase activation. As a consequence of treatment, key EGFR-dependent intracellular signals in cancer cells are affected. Data explaining the mechanisms of action of anti-EGFR monoclonal antibodies, currently used in clinical setting and under development for the treatment of solid tumors, are revised with the aim to provide an overview of the most important preclinical studies showing the impact of this class of EGFR targeted agents on tumor biology.

  9. Determination of antimicrobial effect, antioxidant activity and ...

    African Journals Online (AJOL)

    activity against four Gram-positive and five Gram-negative bacteria, and one yeast using a micro dilution method. In this study, the highest minimum inhibitory concentration (MIC) value was observed with the acetone extract (MIC, 4.8 ìg/mL) against Candida albicans. Maximum antimicrobial effect was also determined with ...

  10. Comparative analysis of the EGFR, HER2, c-MYC, and MET variations in colorectal cancer determined by three different measures: gene copy number gain, amplification status and the 2013 ASCO/CAP guideline criterion for HER2 testing of breast cancer.

    Science.gov (United States)

    Kwak, Yoonjin; Yun, Sumi; Nam, Soo Kyung; Seo, An Na; Lee, Kyu Sang; Shin, Eun; Oh, Heung-Kwon; Kim, Duck Woo; Kang, Sung Bum; Kim, Woo Ho; Lee, Hye Seung

    2017-08-01

    The purpose of this study was to explore gene copy number (GCN) variation of EGFR, HER2, c-MYC, and MET in patients with primary colorectal cancer (CRC). Dual-colour silver-enhanced in situ hybridization was performed in tissue samples of 334 primary CRC patients. The amplification status (GCN ratio ≥2) and GCN gain (average GCN ≥4) data for the EGFR, HER2, c-MYC and MET genes were obtained. GCN variation was also assessed by the criterion of the 2013 ASCO/CAP guidelines for HER2 testing. Amplification of EGFR, HER2, c-MYC and MET was detected in 8 (2.4%), 20 (6.0%), 29 (8.7%), and 14 (4.2%) patients, respectively. Of 66 patients with at least one amplified gene, five exhibited co-amplification of genes studied (HER2-MET co-amplification: two patients; HER2-c-MYC co-amplification: two patients; EGFR-c-MYC co-amplification: one patient). There were 109 patients with GCN gains of one or more genes (EGFR: 11/334, HER2: 29/334, c-MYC; 60/334, MET: 48/334) and 32.1% (35/109) had multiple GCN gains. When each GCN was assessed by the criterion of the ASCO/CAP 2013 guideline for HER2 testing, 116 people showed positive or equivocal results for one or more genes. The cumulative amplification status had no association with patients' outcome. However, the cumulative results of the GCN gain and GCN status determined according to the ASCO/CAP guideline had a significant prognostic correlation in the univariate analysis (P values of 0.006 and 0.022, respectively). In the multivariate analysis, GCN gain and GCN status were independent prognostic factors (P values of 0.010 and 0.017, respectively). In this study, we evaluated GCN variation of four genes in a large sample of Korean CRC patients. The amplification status was not related to patient outcome. However, the GCN gain and GCN status according to the ASCO/CAP 2013 guideline were independent prognostic factors.

  11. Is the eGFR formula adequate for evaluating renal function before chemotherapy in patients with urogenital cancer? A suggestion for clinical application of eGFR formula.

    Science.gov (United States)

    Uozumi, Jiro; Noguchi, Mitsuru; Tokuda, Yuji; Tobu, Shohei; Udo, Kazuma; Kakinoki, Hiroaki; Kurata, Saya; Nanri, Maki; Ichibagase, Yuka; Takahara, Kohei

    2015-08-01

    Accurate evaluation of renal function is required before cancer chemotherapy. Various kinds of formula have been developed for estimating creatinine clearance (Ccr) or glomerular filtration rate (GFR) conveniently. We retrospectively examined the reliability of the GFR estimating formula using the renal function data in cancer chemotherapy. Clinical data of 12 patients with urogenital cancer from 1998 to 2013 in Saga University Hospital were reviewed. Patients were treated with 6-21 (median 10.5) courses of chemotherapy and those patients underwent 9-29 (median 14.5) times of 24hrCcr tests before and during chemotherapy. We compared estimated GFR (eGFR) with 24hrCcr. In addition, we developed a novel method to estimate the Ccr using the patient-inherent 24hrCcr/eGFR ratio, which is calculated from initial 3 or 4 determinations of 24hrCcr and the corresponding eGFR. Those estimated Ccrs were also compared with 24hrCcr. The dissociation between 24hrCcr and eGFR was not constant, and a large dissociation was observed in some cases. The newly devised estimated Ccr demonstrated less dissociation from 24hrCcr compared with eGFR. The eGFR formula is not adequate for the clinical use in cancer chemotherapy. The absolute value of eGFR is not reliable, but clinical use of eGFR as relative value seems to be acceptable. To avoid troublesome 24hrCcr measurement in long-term cancer chemotherapy, eGFR formula can be used for estimating Ccr in combination with the specific inherent 24hrCcr/eGFR ratio, which is obtained from 3 or 4 times of actual 24hrCcr measurements.

  12. Characterization of ABT-806, a Humanized Tumor-Specific Anti-EGFR Monoclonal Antibody.

    Science.gov (United States)

    Reilly, Edward B; Phillips, Andrew C; Buchanan, Fritz G; Kingsbury, Gillian; Zhang, Yumin; Meulbroek, Jonathan A; Cole, Todd B; DeVries, Peter J; Falls, Hugh D; Beam, Christine; Gu, Jinming; Digiammarino, Enrico L; Palma, Joann P; Donawho, Cherrie K; Goodwin, Neal C; Scott, Andrew M

    2015-05-01

    Despite clinical efficacy, current approved agents targeting EGFR are associated with on-target toxicities as a consequence of disrupting normal EGFR function. MAb 806 is a novel EGFR antibody that selectively targets a tumor-selective epitope suggesting that a mAb 806-based therapeutic would retain antitumor activity without the on-target toxicities associated with EGFR inhibition. To enable clinical development, a humanized variant of mAb 806 designated ABT-806 was generated and is currently in phase 1 trials. We describe the characterization of binding and functional properties of ABT-806 compared with the clinically validated anti-EGFR antibody cetuximab. ABT-806 binds the mutant EGFRvIII with high affinity and, relative to cetuximab, exhibits increased potency against glioblastoma multiforme cell line and patient-derived xenografts expressing this form of the receptor. ABT-806 also inhibits the growth of squamous cell carcinoma xenograft models expressing high levels of wild-type EGFR, associated with inhibition of EGFR signaling, although higher doses of ABT-806 than cetuximab are required for similar activity. ABT-806 enhances in vivo potency of standard-of-care therapies used to treat glioblastoma multiforme and head and neck squamous cell carcinoma. An indium-labeled version of ABT-806, [(111)In]-ABT-806, used to investigate the relationship between dose and receptor occupancy, revealed greater receptor occupancy at lowers doses in an EGFRvIII-expressing model and significant uptake in an orthotopic model. Collectively, these results suggest that ABT-806 may have antitumor activity superior to cetuximab in EGFRvIII-expressing tumors, and similar activity to cetuximab in tumors highly overexpressing wild-type EGFR with reduced toxicity. ©2015 American Association for Cancer Research.

  13. The relevance of EGFR overexpression for the prediction of the malignant transformation of oral leukoplakia.

    Science.gov (United States)

    Ries, Jutta; Vairaktaris, Eleftherios; Agaimy, Abbas; Bechtold, Moritz; Gorecki, Patricia; Neukam, Friedrich W; Nkenke, Emeka

    2013-09-01

    The present study evaluated the relevance of EGFR overexpression in prediction of malignant transformation of oral leukoplakia (OLP). The retrospective study comprised paraffin-embedded tissue samples of OLP that transformed into oral squamous cell carcinoma (OSCC) (n=53) and tissue samples of OLP that did not transform into OSCC (n=45) during a follow-up period of 5 years. EGFR overexpression was assessed immunohistochemically. A significantly different expression rate of EGFR was determined between transformed and non-transformed OLP (p=0.017). A statistically significant increase of EGFR expression for low dysplasia lesions in group I compared to group II was proven (D0, p=0.013; D1, p=0.049). By calculation of ROC curve and determination of highest Youden index the optimal threshold value [cut-off point (COP) = 44.96] for distinguishing the transformed from non-transformed lesions was estimated (critical expression rate of EGFR). Using the determined COP the correlation between high-risk lesions and the detection of increased expression rates were significant (p=0.001). In the future, the assessment of EGFR overexpression in OLP may allow identifying OLP lesions with an increased risk of malignant transformation that may have been regarded harmless when only the grade of dysplasia had been taken into account.

  14. Identification of potent EGFR inhibitors from TCM Database@Taiwan.

    Directory of Open Access Journals (Sweden)

    Shun-Chieh Yang

    2011-10-01

    Full Text Available Overexpression of epidermal growth factor receptor (EGFR has been associated with cancer. Targeted inhibition of the EGFR pathway has been shown to limit proliferation of cancerous cells. Hence, we employed Traditional Chinese Medicine Database (TCM Database@Taiwan (http://tcm.cmu.edu.tw to identify potential EGFR inhibitor. Multiple Linear Regression (MLR, Support Vector Machine (SVM, Comparative Molecular Field Analysis (CoMFA, and Comparative Molecular Similarities Indices Analysis (CoMSIA models were generated using a training set of EGFR ligands of known inhibitory activities. The top four TCM candidates based on DockScore were 2-O-caffeoyl tartaric acid, Emitine, Rosmaricine, and 2-O-feruloyl tartaric acid, and all had higher binding affinities than the control Iressa®. The TCM candidates had interactions with Asp855, Lys716, and Lys728, all which are residues of the protein kinase binding site. Validated MLR (r² = 0.7858 and SVM (r² = 0.8754 models predicted good bioactivity for the TCM candidates. In addition, the TCM candidates contoured well to the 3D-Quantitative Structure-Activity Relationship (3D-QSAR map derived from the CoMFA (q² = 0.721, r² = 0.986 and CoMSIA (q² = 0.662, r² = 0.988 models. The steric field, hydrophobic field, and H-bond of the 3D-QSAR map were well matched by each TCM candidate. Molecular docking indicated that all TCM candidates formed H-bonds within the EGFR protein kinase domain. Based on the different structures, H-bonds were formed at either Asp855 or Lys716/Lys728. The compounds remained stable throughout molecular dynamics (MD simulation. Based on the results of this study, 2-O-caffeoyl tartaric acid, Emitine, Rosmaricine, and 2-O-feruloyl tartaric acid are suggested to be potential EGFR inhibitors.

  15. 2D-QSAR and 3D-QSAR Analyses for EGFR Inhibitors

    Directory of Open Access Journals (Sweden)

    Manman Zhao

    2017-01-01

    Full Text Available Epidermal growth factor receptor (EGFR is an important target for cancer therapy. In this study, EGFR inhibitors were investigated to build a two-dimensional quantitative structure-activity relationship (2D-QSAR model and a three-dimensional quantitative structure-activity relationship (3D-QSAR model. In the 2D-QSAR model, the support vector machine (SVM classifier combined with the feature selection method was applied to predict whether a compound was an EGFR inhibitor. As a result, the prediction accuracy of the 2D-QSAR model was 98.99% by using tenfold cross-validation test and 97.67% by using independent set test. Then, in the 3D-QSAR model, the model with q2=0.565 (cross-validated correlation coefficient and r2=0.888 (non-cross-validated correlation coefficient was built to predict the activity of EGFR inhibitors. The mean absolute error (MAE of the training set and test set was 0.308 log units and 0.526 log units, respectively. In addition, molecular docking was also employed to investigate the interaction between EGFR inhibitors and EGFR.

  16. EGFR-STAT3 signaling promotes formation of malignant peripheral nerve sheath tumors.

    Science.gov (United States)

    Wu, J; Patmore, D M; Jousma, E; Eaves, D W; Breving, K; Patel, A V; Schwartz, E B; Fuchs, J R; Cripe, T P; Stemmer-Rachamimov, A O; Ratner, N

    2014-01-09

    Malignant peripheral nerve sheath tumors (MPNSTs) develop sporadically or in the context of neurofibromatosis type 1. Epidermal growth factor receptor (EGFR) overexpression has been implicated in MPNST formation, but its precise role and relevant signaling pathways remain unknown. We found that EGFR overexpression promotes mouse neurofibroma transformation to aggressive MPNST (GEM-PNST). Immunohistochemistry demonstrated phosphorylated STAT3 (Tyr705) in both human MPNST and mouse GEM-PNST. A specific JAK2/STAT3 inhibitor FLLL32 delayed MPNST formation in an MPNST xenograft nude mouse model. STAT3 knockdown by shRNA prevented MPNST formation in vivo. Finally, reducing EGFR activity strongly reduced pSTAT3 in vivo. Thus, an EGFR-STAT3 pathway is necessary for MPNST transformation and establishment of MPNST xenografts growth but not for tumor maintenance. Efficacy of the FLLL32 pharmacological inhibitor in delaying MPNST growth suggests that combination therapies targeting JAK/STAT3 might be useful therapeutics.

  17. Therapeutic IMC-C225 antibody inhibits breast cancer cell invasiveness via Vav2-dependent activation of RhoA GTPase.

    Science.gov (United States)

    Molli, Poonam R; Adam, Liana; Kumar, Rakesh

    2008-10-01

    Abnormalities in the expression and signaling pathways downstream of epidermal growth factor receptor (EGFR) contribute to progression, invasion, and maintenance of the malignant phenotype in human cancers. Accordingly, biological agents, such as the EGFR-blocking antibody IMC-C225 have promising anticancer potential and are currently in various stages of clinical development. Because use of IMC-C225 is limited, at present, only for treatment of cancer with high EGFR expression, the goal of the present study was to determine the effect of IMC-C225 on the invasiveness of breast cancer cells with high and low levels of EGFR expression. The effect of IMC-C225 on invasion was studied using breast cancer cell lines with high and low levels of EGFR expression. The addition of EGF led to progressive stress fiber dissolution. In contrast, cells treated with IMC-C225 showed reduced invasiveness and increased stress-fiber formation. Interestingly, IMC-C225 pretreatment was accompanied by EGFR phosphorylation, as detected using an anti-phosphorylated tyrosine antibody (PY99), which correlated with phosphorylation of Vav2 guanine nucleotide exchange factor and activation of RhoA GTPase irrespective of EGFR level, and Vav2 interacted with EGFR only in IMC-C225-treated cells. The underlying mechanism involved an enhanced interaction between beta1 integrins and EGFR upon IMC-C225 treatment. Here, we defined a new mechanism for IMC-C225 that cross-links integrins with EGFR, leading to activation of RhoA and inhibition of breast cancer cell invasion irrespective of the level of EGFR in the cells, thus providing a rationale for using IMC-C225 in the metastatic setting independent of the levels of EGFR.

  18. EGFR Mutation Status in Uighur Lung Adenocarcinoma Patients

    OpenAIRE

    Shan, Li; Zhang, Yan; Zhao, Feng; Limou ZHENG; Zhang, Guoqing

    2013-01-01

    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 ...

  19. Downregulation of E-Cadherin enhances proliferation of head and neck cancer through transcriptional regulation of EGFR

    Directory of Open Access Journals (Sweden)

    Shin Dong M

    2011-09-01

    Full Text Available Abstract Background Epidermal growth factor receptor (EGFR has been reported to downregulate E-cadherin (E-cad; however, whether the downregulation of E-cad has any effect on EGFR expression has not been elucidated. Our previous studies have found an inverse correlation between EGFR and E-cad expression in tissue specimens of squamous cell carcinoma of the head and neck (SCCHN. To understand the biological mechanisms underlying this clinical observation, we knocked down E-cad expression utilizing E-cad siRNA in four SCCHN cell lines. Results It was observed that downregulation of E-cad upregulated EGFR expression compared with control siRNA-transfected cells after 72 hours. Cellular membrane localization of EGFR was also increased. Consequently, downstream signaling molecules of the EGFR signaling pathway, p-AKT, and p-ERK, were increased at 72 hours after the transfection with E-cad siRNA. Reverse transcriptase-polymerase chain reaction (RT-PCR showed EGFR mRNA was upregulated by E-cad siRNA as early as 24 hours. In addition, RT-PCR revealed this upregulation was due to the increase of EGFR mRNA stability, but not protein stability. Sulforhodamine B (SRB assay indicated growth of E-cad knocked down cells was enhanced up to 2-fold more than that of control siRNA-transfected cells at 72-hours post-transfection. The effect of E-cad reduction on cell proliferation was blocked by treating the E-cad siRNA-transfected cells with 1 μM of the EGFR-specific tyrosine kinase inhibitor erlotinib. Conclusion Our results suggest for the first time that reduction of E-cad results in upregulation of EGFR transcriptionally. It also suggests that loss of E-cad may induce proliferation of SCCHN by activating EGFR and its downstream signaling pathways.

  20. Peptide vaccines and peptidomimetics of EGFR (HER-1) ligand binding domain inhibit cancer cell growth in vitro and in vivo.

    Science.gov (United States)

    Foy, Kevin Chu; Wygle, Ruthie M; Miller, Megan J; Overholser, Jay P; Bekaii-Saab, Tanios; Kaumaya, Pravin T P

    2013-07-01

    Epidermal growth factor receptor (EGFR) is a validated target for several cancers including lung, colorectal, and certain subtypes of breast cancer. Cetuximab targets ligand binding of EGFR, but major problems like high cost, short t1/2, toxicity, and emergence of resistance are associated with the drug. Immunization with EGFR B cell epitopes will train the immune system to produce specific Abs that can kill cancer cells. Also, therapy with stable, less-expensive, and nontoxic EGFR peptide mimics will block EGFR signaling and inhibit cancer growth. We designed three peptides based on the contact sites between EGF and EGFR. The B cell epitopes were synthesized alone and also linked with the measles virus T cell epitope to produce a chimeric peptide vaccine. The peptide vaccines were immunogenic in both mice and rabbits and Abs raised against the vaccine specifically bound EGFR-expressing cells and recombinant human EGFR protein. The peptide mimics and the anti-peptide Abs were able to inhibit EGFR signaling pathways. Immunization with the peptide vaccine or treatment with the B cell epitopes significantly reduced tumor growth in both transplantable breast and lung cancer models. Immunohistochemical analysis also showed significant reductions in microvascular density and actively dividing cells in the tumor sections after treatment in the FVB/n breast cancer model. The 418-435 B cell epitope was the best candidate both as a vaccine or peptide mimic because it caused significant inhibition in the two mouse models. Our results show that this novel EGFR B cell epitope has great potential to be used as a vaccine or treatment option for EGFR-expressing cancers.

  1. Assessment of Epidermal Growth Factor Receptor (EGFR expression in human meningioma

    Directory of Open Access Journals (Sweden)

    Perry Arie

    2010-05-01

    Full Text Available Abstract Purpose This study explores whether meningioma expresses epidermal growth factor receptor (EGFR and determines if there is a correlation between the WHO grade of this tumor and the degree of EGFR expression. Methods Following institutional review board approval, 113 meningioma specimens from 89 patients were chosen. Of these, 85 were used for final analysis. After a blinded review, immunohistochemical stains for EGFR were performed. Staining intensity (SI was scored on a scale 0-3 (from no staining to strong staining. Staining percentage of immunoreactive cells (SP was scored 1-5 (from the least to the maximum percent of the specimen staining. Immunohistochemical score (IHS was calculated as the product of SI and SP. Results Eighty-five samples of meningioma were classified in accordance with World Health Organization (WHO criteria: benign 57/85 (67%, atypical 23/85 (27%, and malignant 5/85 (6%. The majority of samples demonstrated a moderate SI for EGFR. IHS for EGFR demonstrated a significant association between SI and histopathologic subtype. Also, there was a correlation between the SP and histopathologic subtype (p = 0.029. A significant association was determined when the benign and the atypical samples were compared to the malignant with respect to the SP (p = 0.009. While there was a range of the IHS for the benign and the atypical histologic subtypes, malignant tumors exhibited the lowest score and were statistically different from the benign and the atypical specimens (p Conclusions To our knowledge, this represents the largest series of meningioma samples analyzed for EGFR expression reported in the literature. EGFR expression is greatest in benign meningiomas and may serve a potential target for therapeutic intervention with selective EGFR inhibitors.

  2. Targeting of Both the c-Met and EGFR Pathways Results in Additive Inhibition of Lung Tumorigenesis in Transgenic Mice

    Energy Technology Data Exchange (ETDEWEB)

    Stabile, Laura P. [Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA 15213 (United States); Lung and Thoracic Malignancy Program, University of Pittsburgh, Pittsburgh, PA 15213 (United States); Rothstein, Mary E. [Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA 15213 (United States); Keohavong, Phouthone [Department of Environmental and Occupational Health, University of Pittsburgh, Pittsburgh, PA 15213 (United States); Lung and Thoracic Malignancy Program, University of Pittsburgh, Pittsburgh, PA 15213 (United States); Lenzner, Diana [Department of Biostatistics, University of Pittsburgh, Pittsburgh, PA 15213 (United States); Land, Stephanie R. [Department of Biostatistics, University of Pittsburgh, Pittsburgh, PA 15213 (United States); Lung and Thoracic Malignancy Program, University of Pittsburgh, Pittsburgh, PA 15213 (United States); Gaither-Davis, Autumn L. [Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA 15213 (United States); Lung and Thoracic Malignancy Program, University of Pittsburgh, Pittsburgh, PA 15213 (United States); Kim, K. Jin [Galaxy Biotech, LLC, Sunnyvale, CA 94089 (United States); Kaminski, Naftali [Department of Medicine, University of Pittsburgh, Pittsburgh, PA 15213 (United States); Lung and Thoracic Malignancy Program, University of Pittsburgh, Pittsburgh, PA 15213 (United States); Siegfried, Jill M., E-mail: siegfriedjm@upmc.edu [Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA 15213 (United States); Lung and Thoracic Malignancy Program, University of Pittsburgh, Pittsburgh, PA 15213 (United States)

    2010-12-22

    EGFR and c-Met are both overexpressed in lung cancer and initiate similar downstream signaling, which may be redundant. To determine how frequently ligands that initiate signaling of both pathways are found in lung cancer, we analyzed serum for hepatocyte growth factor (HGF), transforming growth factor-alpha, and amphiregulin (AREG) in lung cancer cases and tobacco-exposed controls. HGF and AREG were both significantly elevated in cases compared to controls, suggesting that both HGF/c-Met and AREG/EGFR pathways are frequently active. When both HGF and AREG are present in vitro, downstream signaling to MAPK and Akt in non-small cell lung cancer (NSCLC) cells can only be completely inhibited by targeting both pathways. To test if dual blockade of the pathways could better suppress lung tumorigenesis in an animal model than single blockade, mice transgenic for airway expression of human HGF were treated with inhibitors of both pathways alone and in combination after exposure to a tobacco carcinogen. Mean tumor number in the group using both the HGF neutralizing antibody L2G7 and the EGFR inhibitor gefitinib was significantly lower than with single agents. A higher tumor K-ras mutation rate was observed with L2G7 alone compared to controls, suggesting that agents targeting HGF may be less effective against mutated K-ras lung tumors. This was not observed with combination treatment. A small molecule c-Met inhibitor decreased formation of both K-ras wild-type and mutant tumors and showed additive anti-tumor effects when combined with gefitinib. Dual targeting of c-Met/EGFR may have clinical benefit for lung cancer.

  3. LIGAND-INDEPENDENT PHOSPHORYLATION OF Y869 LINKS MUTANT EGFR SIGNALING TO STAT-MEDIATED GENE EXPRESSION

    Science.gov (United States)

    Yang, Seungchan; Park, Kyungho; Turkson, James; Arteaga, Carlos L.

    2011-01-01

    Activating mutants of EGFR have been identified in a subset of non-small-cell lung cancers. To investigate mutant-driven signaling, we focused on Y869, a residue in the same activation loop where the L858R and L861Q mutations are located. We observed ligand-independent phosphorylation of Y869 in 32D cells EGFRL858R and EGFRL861Q. The EGFR tyrosine kinase inhibitor (TKI) erlotinib inhibited Y869 P-EGFR in intact cells as well as in a cell-free kinase reaction. Expression of kinase domain of EGFRL858R and EGFRL861Q exhibited auto-phosphorylation of Y869; this was inhibited by EGFR TKIs but not by Src kinase inhibitor. P-Y859 of EGFR-mediated downstream component, STAT5, was also analyzed. Y694 P-STAT5 was eliminated by erlotinib treatment. Analysis of immune-complexes showed constitutive association of mutant EGFRs with STAT5 and Src which was unaffected by erlotinib or PP1. On the other hand, 32D-EGFRWT exhibited constitutive STAT5 phosphorylation and association of EGFR with JAK2. In these cells, a JAK2 inhibitor abrogated P-STAT5 whereas mutant EGFRs did not associate with JAK2. Expression of c-myc was regulated by EGFR/STAT5 signaling in cells expressing EGFRL858R and EGFRL861Q. Our results suggest that ligand-independent and Src activity-independent phosphorylation of Y869 in mutant EGFR regulates STAT5 activation and c-myc expression. PMID:17927978

  4. Immunohistochemical Detections of EGFR Mutations in NSCLC

    Directory of Open Access Journals (Sweden)

    Chang LIU

    2014-09-01

    Full Text Available In recent years, it has been well known that non-small cell lung cancer (NSCLC patients with mutations of epidermal growth factor receptor (EGFR response better to EGFR-tyrosine kinase inhibitor treatment. Although DNA-based assays (e.g. DNA sequencing are the most frequently used and a relatively reliable method to detect EGFR mutations, they are complex, time-consuming and relatively expensive for routine use in clinical laboratories, besides they require high quality tumor samples. In contrast, the immunohistochemistry (IHC methods make up fully for the above shortcomings and can serve as screening tests for EGFR mutations. However, there are many factors that can influence the results of IHC methods, such as different staining procedures, different antigen retrieval solutions and different sets of criteria, etc. Thus the IHC methods for detecting EGFR mutations have not been widely used in clinic and only in the research stage. This article reviews the use of IHC methods by different researchers and further discusses how to make the IHC methods work best for the detection of EGFR mutations.

  5. Determination of Russian innovative activity tendencies

    Directory of Open Access Journals (Sweden)

    Marina A. Motova

    2016-01-01

    Higher School of Economics and «The Russian Statistical Year-Book» of Rosstat.Data on a condition of the innovative sphere in Russia, and, also data on profitability of financial investments cover the industrial production (the extracting and processing productions and the enterprises on production and electric power, gas and water distribution, and also some industries of the service sector. The analysis covers the data for the period of 2005-2014. It covers the data on the innovation-active organizations, engaged in technological innovations by main types of economic and innovative activity. In total the given results, from our point of view, can become a basis for the choice of the directions of investment activity.Development of forecasts of the main indicators of the innovative sphere shall become the perspective direction of research continuation. The received forecasts will be the basis for the cluster analysis procedure for the purpose of prospects’ determination for the development of investment activity in innovation-active sectors of economy

  6. Molecular Epidemiology of EGFR Mutations in Asian Patients with Advanced Non-Small-Cell Lung Cancer of Adenocarcinoma Histology - Mainland China Subset Analysis of the PIONEER study.

    Directory of Open Access Journals (Sweden)

    Yuankai Shi

    Full Text Available Epidermal growth factor receptor (EGFR mutations are the strongest response predictors to EGFR tyrosine kinase inhibitors (TKI therapy, but knowledge of the EGFR mutation frequency on lung adenocarcinoma is still limited to retrospective studies. The PIONEER study (NCT01185314 is a prospective molecular epidemiology study in Asian patients with newly diagnosed advanced lung adenocarcinoma, aiming to prospectively analyze EGFR mutation status in IIIB/IV treatment-naïve lung adenocarcinomas in Asia. We report the mainland China subset results. Eligible patients (≥20 yrs old, IIIB/IV adenocarcinoma and treatment-naïve were registered in 17 hospitals in mainland China. EGFR was tested for mutations by amplification refractory mutation system using biopsy samples. Demographic and clinical characteristics were collected for subgroup analyses. A total of 747 patients were registered. Successful EGFR mutation analysis was performed in 741, with an overall mutation rate of 50.2%. The EGFR active mutation rate is 48.0% (with 1.3% of combined active and resistance mutations. Tobacco use (>30 pack-year vs. 0-10 pack-year, OR 0.27, 95%CI: 0.17-0.42 and regional lymph nodes involvement (N3 vs. N0, OR 0.47, 95%CI: 0.29-0.76 were independent predictors of EGFR mutation in multivariate analysis. However, even in regular smokers, the EGFR mutation frequency was 35.3%. The EGFR mutation frequency was similar between diverse biopsy sites and techniques. The overall EGFR mutation frequency of the mainland China subset was 50.2%, independently associated with the intensity of tobacco use and regional lymph nodes involvement. The relatively high frequency of EGFR mutations in the mainland China subset suggest that any effort to obtain tissue sample for EGFR mutation testing should be encouraged.

  7. egr-4, a target of EGFR signaling, is required for the formation of the brain primordia and head regeneration in planarians.

    Science.gov (United States)

    Fraguas, Susanna; Barberán, Sara; Iglesias, Marta; Rodríguez-Esteban, Gustavo; Cebrià, Francesc

    2014-05-01

    During the regeneration of freshwater planarians, polarity and patterning programs play essential roles in determining whether a head or a tail regenerates at anterior or posterior-facing wounds. This decision is made very soon after amputation. The pivotal role of the Wnt/β-catenin and Hh signaling pathways in re-establishing anterior-posterior (AP) polarity has been well documented. However, the mechanisms that control the growth and differentiation of the blastema in accordance with its AP identity are less well understood. Previous studies have described a role of Smed-egfr-3, a planarian epidermal growth factor receptor, in blastema growth and differentiation. Here, we identify Smed-egr-4, a zinc-finger transcription factor belonging to the early growth response gene family, as a putative downstream target of Smed-egfr-3. Smed-egr-4 is mainly expressed in the central nervous system and its silencing inhibits anterior regeneration without affecting the regeneration of posterior regions. Single and combinatorial RNA interference to target different elements of the Wnt/β-catenin pathway, together with expression analysis of brain- and anterior-specific markers, revealed that Smed-egr-4: (1) is expressed in two phases - an early Smed-egfr-3-independent phase and a late Smed-egfr-3-dependent phase; (2) is necessary for the differentiation of the brain primordia in the early stages of regeneration; and (3) that it appears to antagonize the activity of the Wnt/β-catenin pathway to allow head regeneration. These results suggest that a conserved EGFR/egr pathway plays an important role in cell differentiation during planarian regeneration and indicate an association between early brain differentiation and the proper progression of head regeneration.

  8. An open label phase II study evaluating first-line EGFR tyrosine kinase inhibitor erlotinib in non-small cell lung cancer patients with tumors showing high EGFR gene copy number

    Science.gov (United States)

    Kowalczyk, Anna; Suszko-Kazarnowicz, Malgorzata; Duchnowska, Renata; Szczesna, Aleksandra; Ratajska, Magdalena; Sowa, Aleksander; Limon, Janusz; Biernat, Wojciech; Burzykowski, Tomasz; Jassem, Jacek; Dziadziuszko, Rafal

    2017-01-01

    Background First-line treatment with epidermal growth factor receptor (EGFR) inhibitors in NSCLC is effective in patients with activating EGFR mutations. The activity of erlotinib in patients harboring high EGFR gene copy number has been considered debatable. Patients and Methods A multicenter, open-label, single-arm phase II clinical trial was performed to test the efficacy of erlotinib in the first-line treatment of NSCLC patients harboring high EGFR gene copy number defined as =4 copies in =40% of cells. Findings Between December 2007 and April 2011, tumor samples from 149 subjects were screened for EGFR gene copy number by fluorescence in-situ hybridization (FISH), Out of 49 patients with positive EGFR FISH test, 45 were treated with erlotinib. Median PFS in the intent-to-treat population was 3.3 months (95%CI: 1.83.9 months), and median overall survival was 7.9 months (95% CI: 5.112.6 months). Toxicity profile of erlotinib was consistent with its known safety profile. The trial was stopped prematurely at 63% of originally planned sample size due to accumulating evidence that EGFR gene copy number should not be used to select NSCLC patients to first-line therapy with EGFR TKI. Data on erlotinib efficacy according to EGFR, KRAS and BRAF mutations are additionally presented. Interpretation This trial argues against using high gene copy number for selection of NSCLC patients to first-line therapy with EGFR TKIs. The study adds to the discussion on efficacy of other targeted agents in patients with target gene amplified tumors. PMID:27924059

  9. An open label phase II study evaluating first-line EGFR tyrosine kinase inhibitor erlotinib in non-small cell lung cancer patients with tumors showing high EGFR gene copy number.

    Science.gov (United States)

    Szutowicz-Zielińska, Ewa; Konopa, Krzysztof; Kowalczyk, Anna; Suszko-Każarnowicz, Małgorzata; Duchnowska, Renata; Szczęsna, Aleksandra; Ratajska, Magdalena; Sowa, Aleksander; Limon, Janusz; Biernat, Wojciech; Burzykowski, Tomasz; Jassem, Jacek; Dziadziuszko, Rafał

    2017-03-07

    First-line treatment with epidermal growth factor receptor (EGFR) inhibitors in NSCLC is effective in patients with activating EGFR mutations. The activity of erlotinib in patients harboring high EGFR gene copy number has been considered debatable. A multicenter, open-label, single-arm phase II clinical trial was performed to test the efficacy of erlotinib in the first-line treatment of NSCLC patients harboring high EGFR gene copy number defined as ≥4 copies in ≥40% of cells. Between December 2007 and April 2011, tumor samples from 149 subjects were screened for EGFR gene copy number by fluorescence in-situ hybridization (FISH), Out of 49 patients with positive EGFR FISH test, 45 were treated with erlotinib. Median PFS in the intent-to-treat population was 3.3 months (95%CI: 1.8-3.9 months), and median overall survival was 7.9 months (95% CI: 5.1-12.6 months). Toxicity profile of erlotinib was consistent with its known safety profile. The trial was stopped prematurely at 63% of originally planned sample size due to accumulating evidence that EGFR gene copy number should not be used to select NSCLC patients to first-line therapy with EGFR TKI. Data on erlotinib efficacy according to EGFR, KRAS and BRAF mutations are additionally presented. This trial argues against using high gene copy number for selection of NSCLC patients to first-line therapy with EGFR TKIs. The study adds to the discussion on efficacy of other targeted agents in patients with target gene amplified tumors.

  10. Comparative analysis of clinicoradiologic characteristics of lung adenocarcinomas with ALK rearrangements or EGFR mutations

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, J.Y.; Zheng, J.; Chen, X.; Zhou, J.Y. [Zhejiang University, Department of Respiratory Disease, Thoracic Disease Center, First Affiliated Hospital, College of Medicine, Hangzhou (China); Yu, Z.F.; Xiao, W.B.; Jiang, L.N. [Zhejiang University, Department of Radiology, First Affiliated Hospital, College of Medicine, Hangzhou (China); Zhao, J.; Sun, K.; Wang, B.; Ding, W. [Zhejiang University, Department of Pathology, First Affiliated Hospital, College of Medicine, Hangzhou (China)

    2015-05-01

    To compare the clinicoradiologic features of tumours with echinoderm anaplastic lymphoma kinase (ALK) rearrangements, epidermal growth factor receptor (EGFR) mutations, or wild type (WT) for both genes in a cohort of patients with lung adenocarcinoma to identify useful characteristics of different gene statuses. In 346 lung adenocarcinoma patients, ALK rearrangements were confirmed with fluorescence in situ hybridisation, and EGFR mutations were determined by pyrosequencing assay. Patients were divided into three groups: ALK rearrangement (ALK+ group, n = 48), EGFR mutation (EGFR+ group, n = 166), and WT for both genes (WT group, n = 132). Chest computed tomography (CT) examinations were performed in all patients. The percentages of ground-glass opacity volume (pGGO) and tumour shadow disappearance rate (TDR) were measured using semi-automated nodule assessment software. The pGGO was significantly lower in the ALK+ group (25.1 % ± 24.3) than in the EGFR+ group (37.2 % ± 25.7, p < 0.001) and the WT group (36.1 % ± 24.6, p = 0.001). The TDR in the ALK+ group (17.3 % ± 25.1) was significantly lower than in the EGFR+ group (26.8 % ± 24.9, p = 0.002) and the WT group (25.7 % ± 24.6, p = 0.003). Solid pattern with lower incidence of lobulated border, finely spiculated margins, pleural retraction, and bubble-like lucency on CT imaging are the main characteristics of ALK rearrangement tumours. (orig.)

  11. Research progress on criteria for discontinuation of EGFR inhibitor therapy

    Directory of Open Access Journals (Sweden)

    Zhuang HQ

    2012-10-01

    Full Text Available Hong-qing Zhuang, Zhi-yong Yuan, Jun Wang, Ping Wang, Lu-jun Zhao, Bai-lin ZhangDepartment of Radiotherapy, Tianjin Medical University Cancer Institute and Hospital, Tianjin Key Laboratory of Cancer Prevention and Therapy, Tianjin Lung Cancer Center, Tianjin, People's Republic of ChinaAbstract: The clinical success of the epidermal growth factor receptor (EGFR tyrosine kinase inhibitors (TKI as therapeutic agents has prompted great interest in their further development and clinical testing for a wide variety of malignancies. However, most studies have focused on the efficacy of TKI, and few studies have been done on the criteria for their discontinuation. The current standard for drug discontinuation is “until progression”, based on change in tumor size. However, tumor size is not related to the gene expression which determines the efficacy of TKI in the final analysis, and it is also difficult to make a thorough and correct prediction based on tumor size when the TKI is discontinued. Nevertheless, clinical evaluation of the criteria for TKI discontinuation is still in its early days. Some promising findings have started to emerge. With the improving knowledge of EGFR and its inhibitors, it is expected that the criteria for discontinuation of EGFR inhibitor therapy will become clearer.Keywords: epidermal growth factor receptor, drug discontinuation, acquired drug-resistance

  12. Epidermal growth factor receptor (EGFR) and EGFR mutations, function and possible role in clinical trials

    National Research Council Canada - National Science Library

    Rude Voldborg, B; Damstrup, L; Spang-Thomsen, M; Skovgaard Poulsen, H

    1997-01-01

    ... ___________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________ Epidermal growth factor receptor (EGFR) and EGFR mutations, function a n dp o s s i b l er o l ei nc l i n i c a lt r i a l s B. Rude V oldborg, 1 L. Damstrup, 1 M...

  13. FDG-PET/CT response evaluation during EGFR-TKI treatment in patients with NSCLC.

    Science.gov (United States)

    van Gool, Matthijs H; Aukema, Tjeerd S; Hartemink, Koen J; Valdés Olmos, Renato A; van Tinteren, Harm; Klomp, Houke M

    2014-07-28

    Over recent years, [18F]-fluorodeoxyglucose positron emission tomography acquired together with low dose computed tomography (FDG-PET/CT) has proven its role as a staging modality in patients with non-small cell lung cancer (NSCLC). The purpose of this review was to present the evidence to use FDG-PET/CT for response evaluation in patients with NSCLC, treated with epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors (TKI). All published articles from 1 November 2003 to 1 November 2013 reporting on 18F-FDG-PET response evaluation during EGFR-TKI treatment in patients with NSCLC were collected. In total 7 studies, including data of 210 patients were eligible for analyses. Our report shows that FDG-PET/CT response during EGFR-TKI therapy has potential in targeted treatment for NSCLC. FDG-PET/CT response is associated with clinical and radiologic response and with survival. Furthermore FDG-PET/CT response monitoring can be performed as early as 1-2 wk after initiation of EGFR-TKI treatment. Patients with substantial decrease of metabolic activity during EGFR-TKI treatment will probably benefit from continued treatment. If metabolic response does not occur within the first weeks of EGFR-TKI treatment, patients may be spared (further) unnecessary toxicity of ineffective treatment. Refining FDG-PET response criteria may help the clinician to decide on continuation or discontinuation of targeted treatment.

  14. Rapidly acquired resistance to EGFR tyrosine kinase inhibitors in NSCLC cell lines through de-repression of FGFR2 and FGFR3 expression.

    Directory of Open Access Journals (Sweden)

    Kathryn E Ware

    2010-11-01

    Full Text Available Despite initial and sometimes dramatic responses of specific NSCLC tumors to EGFR TKIs, nearly all will develop resistance and relapse. Gene expression analysis of NSCLC cell lines treated with the EGFR TKI, gefitinib, revealed increased levels of FGFR2 and FGFR3 mRNA. Analysis of gefitinib action on a larger panel of NSCLC cell lines verified that FGFR2 and FGFR3 expression is increased at the mRNA and protein level in NSCLC cell lines in which the EGFR is dominant for growth signaling, but not in cell lines where EGFR signaling is absent. A luciferase reporter containing 2.5 kilobases of fgfr2 5' flanking sequence was activated after gefitinib treatment, indicating transcriptional regulation as a contributing mechanism controlling increased FGFR2 expression. Induction of FGFR2 and FGFR3 protein as well as fgfr2-luc activity was also observed with Erbitux, an EGFR-specific monoclonal antibody. Moreover, inhibitors of c-Src and MEK stimulated fgfr2-luc activity to a similar degree as gefitinib, suggesting that these pathways may mediate EGFR-dependent repression of FGFR2 and FGFR3. Importantly, our studies demonstrate that EGFR TKI-induced FGFR2 and FGFR3 are capable of mediating FGF2 and FGF7 stimulated ERK activation as well as FGF-stimulated transformed growth in the setting of EGFR TKIs. In conclusion, this study highlights EGFR TKI-induced FGFR2 and FGFR3 signaling as a novel and rapid mechanism of acquired resistance to EGFR TKIs and suggests that treatment of NSCLC patients with combinations of EGFR and FGFR specific TKIs may be a strategy to enhance efficacy of single EGFR inhibitors.

  15. Kaempferol inhibits cell proliferation and glycolysis in esophagus squamous cell carcinoma via targeting EGFR signaling pathway.

    Science.gov (United States)

    Yao, Shihua; Wang, Xiaowei; Li, Chunguang; Zhao, Tiejun; Jin, Hai; Fang, Wentao

    2016-08-01

    Antitumor activity of kaempferol has been studied in various tumor types, but its potency in esophagus squamous cell carcinoma is rarely known. Here, we reported the activity of kaempferol against esophagus squamous cell carcinoma as well as its antitumor mechanisms. Results of cell proliferation and colony formation assay showed that kaempferol substantially inhibited tumor cell proliferation and clone formation in vitro. Flow cytometric analysis demonstrated that tumor cells were induced G0/G1 phase arrest after kaempferol treatment, and the expression of protein involved in cell cycle regulation was dramatically changed. Except the potency on cell proliferation, we also discovered that kaempferol had a significant inhibitory effect against tumor glycolysis. With the downregulation of hexokinase-2, glucose uptake and lactate production in tumor cells were dramatically declined. Mechanism studies revealed kaempferol had a direct effect on epidermal growth factor receptor (EGFR) activity, and along with the inhibition of EGFR, its downstream signaling pathways were also markedly suppressed. Further investigations found that exogenous overexpression of EGFR in tumor cells substantially attenuated glycolysis suppression induced by kaempferol, which implied that EGFR also played an important role in kaempferol-mediated glycolysis inhibition. Finally, the antitumor activity of kaempferol was validated in xenograft model and kaempferol prominently restrained tumor growth in vivo. Meanwhile, dramatic decrease of EGFR activity and hexokinase-2 expression were observed in kaempferol-treated tumor tissue, which confirmed these findings in vitro. Briefly, these studies suggested that kaempferol, or its analogues, may serve as effective candidates for esophagus squamous cell carcinoma management.

  16. Radiotherapy of non-small-cell lung cancer in the era of EGFR gene mutations and EGF receptor tyrosine kinase inhibitors.

    Science.gov (United States)

    Moschini, Ilaria; Dell'Anna, Cristina; Losardo, Pier Luigi; Bordi, Paola; D'Abbiero, Nunziata; Tiseo, Marcello

    2015-01-01

    Non-small-cell lung cancer (NSCLC) occurs, approximately, in 80-85% of all cases of lung cancer. The majority of patients present locally advanced or metastatic disease when diagnosed, with poor prognosis. The discovery of activating mutations in the EGFR gene has started a new era of personalized treatment for NSCLC patients. To improve the treatment outcome in patients with unresectable NSCLC and, in particular, EGFR mutated, a combined strategy of radiotherapy and medical treatment can be undertaken. In this review we will discuss preclinical data regarding EGF receptor (EGFR) tyrosine kinase inhibitors (TKIs) and radiotherapy, available clinical trials investigating efficacy and toxicity of combined treatment (thoracic or whole brain radiotherapy and EGFR-TKIs) and, also, the role of local radiation in mutated EGFR patients who developed EGFR-TKI resistance.

  17. Detection of EGFR mutations in plasma and biopsies from non-small cell lung cancer patients by allele-specific PCR assays

    DEFF Research Database (Denmark)

    Weber, Britta; Meldgaard, Peter; Hager, Henrik

    2014-01-01

    samples with allele-specific PCR assays. METHODS: Pairs of the diagnostic biopsy and plasma obtained just prior to start of erlotinib treatment were collected from 199 patients with adenocarcinoma of non-small-cell lung cancer. DNA from both sample types was isolated and examined for the presence...... of mutations in exons 18-21 of the EGFR gene, employing the cobas(®) EGFR Tissue Test and cobas(®) EGFR Blood Test (in development, Roche Molecular Systems, Inc., CA, USA). RESULTS: Test results were obtained in all 199 (100%) plasma samples and 196/199 (98%) of the biopsies. EGFR-activating mutations were...... identified in 24/199 (12%) plasma samples and 28/196 (14%) biopsy samples, and 17/196 (9%) matched pairs contained the same mutation. Six EGFR mutations were present only in plasma samples but not in the biopsy samples. The overall concordance of the EGFR gene mutations detected in plasma and biopsy tissue...

  18. Dynamic conformational transitions of the EGF receptor in living mammalian cells determined by FRET and fluorescence lifetime imaging microscopy.

    Science.gov (United States)

    Ziomkiewicz, Iwona; Loman, Anastasia; Klement, Reinhard; Fritsch, Cornelia; Klymchenko, Andrey S; Bunt, Gertrude; Jovin, Thomas M; Arndt-Jovin, Donna J

    2013-09-01

    We have revealed a reorientation of ectodomain I of the epidermal growth factor receptor (EGFR; ErbB1; Her1) in living CHO cells expressing the receptor, upon binding of the native ligand EGF. The state of the unliganded, nonactivated EGFR was compared to that exhibited after ligand addition in the presence of a kinase inhibitor that prevents endocytosis but does not interfere with binding or the ensuing conformational rearrangements. To perform these experiments, we constructed a transgene EGFR with an acyl carrier protein sequence between the signal peptide and the EGFR mature protein sequence. This protein, which behaves similarly to wild-type EGFR with respect to EGF binding, activation, and internalization, can be labeled at a specific serine in the acyl carrier tag with a fluorophore incorporated into a 4'-phosphopantetheine (P-pant) conjugate transferred enzymatically from the corresponding CoA derivative. By measuring Förster resonance energy transfer between a molecule of Atto390 covalently attached to EGFR in this manner and a novel lipid probe NR12S distributed exclusively in the outer leaflet of the plasma membrane, we determined the apparent relative separation of ectodomain I from the membrane under nonactivating and activating conditions. The data indicate that the unliganded domain I of the EGFR receptor is situated much closer to the membrane before EGF addition, supporting the model of a self-inhibited configuration of the inactive receptor in quiescent cells. Copyright © 2013 International Society for Advancement of Cytometry.

  19. EGFR mutation frequency and effectiveness of erlotinib

    DEFF Research Database (Denmark)

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

    2014-01-01

    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...... AND METHODS: Four hundred and eighty eight patients with advanced NSCLC were included. The mutation status was assessed using the cobas EGFR Mutation Test. Erlotinib was administrated (150 mg/d) until disease progression or unacceptable toxicities occurred. The primary endpoint was progression-free survival....... Secondary endpoints were overall survival and response. RESULTS: Biopsies were retrieved from 467 patients, and mutation results obtained for 462. We identified 57 (12%) patients with EGFR mutations: 33 exon 19 deletions, 13 exon 21 mutations, 5 exon 18 mutations, 3 exon 20 insertions, 1 exon 20 point...

  20. Computational modelling of cancerous mutations in the EGFR/ERK signalling pathway

    Directory of Open Access Journals (Sweden)

    Gormand Amelie

    2009-10-01

    Full Text Available Abstract Background The Epidermal Growth Factor Receptor (EGFR activated Extracellular-signal Regulated Kinase (ERK pathway is a critical cell signalling pathway that relays the signal for a cell to proliferate from the plasma membrane to the nucleus. Deregulation of the EGFR/ERK pathway due to alterations affecting the expression or function of a number of pathway components has long been associated with numerous forms of cancer. Under normal conditions, Epidermal Growth Factor (EGF stimulates a rapid but transient activation of ERK as the signal is rapidly shutdown. Whereas, under cancerous mutation conditions the ERK signal cannot be shutdown and is sustained resulting in the constitutive activation of ERK and continual cell proliferation. In this study, we have used computational modelling techniques to investigate what effects various cancerous alterations have on the signalling flow through the ERK pathway. Results We have generated a new model of the EGFR activated ERK pathway, which was verified by our own experimental data. We then altered our model to represent various cancerous situations such as Ras, B-Raf and EGFR mutations, as well as EGFR overexpression. Analysis of the models showed that different cancerous situations resulted in different signalling patterns through the ERK pathway, especially when compared to the normal EGF signal pattern. Our model predicts that cancerous EGFR mutation and overexpression signals almost exclusively via the Rap1 pathway, predicting that this pathway is the best target for drugs. Furthermore, our model also highlights the importance of receptor degradation in normal and cancerous EGFR signalling, and suggests that receptor degradation is a key difference between the signalling from the EGF and Nerve Growth Factor (NGF receptors. Conclusion Our results suggest that different routes to ERK activation are being utilised in different cancerous situations which therefore has interesting implications

  1. Gefitinib: a pharmacoeconomic profile of its use in patients with Non Small Cell Lung Cancer EGFR+

    Directory of Open Access Journals (Sweden)

    Viola Sacchi

    2011-06-01

    Full Text Available Lung cancer is the most common form of cancer with the highest incidence worldwide. The mortality rates are highest in males and second highest in females, after breast cancer. The genetic predisposition to Non Small Cell Lung Cancer (NSCLC is still under investigation, however, studies have shown that the Epidermal Growth Factor Receptor (EGFR, a receptor tyrosine kinase is frequently over-expressed and activated to a phosphorylated state in NSCLC. The activity of EGFR in cancer cells results in the phosphorylation of downstream proteins that promote cell proliferation, invasion, metastasis, and inhibition of apoptosis. Targeting the EGFR pathway therefore constitutes a relevant strategy for cancer therapy. Gefitinib is a selective inhibitor of the EGFR tyrosine kinase and is indicated for the treatment of adult patients with locally advanced or metastatic NSCLC with activating mutations of EGFR-TK. From the pharmacoeconomic point of view gefitinib is dominant (more effective and less expensive compared to the alternatives. In conclusion, gefitinib is a treatment option for NSCLC tumors with a high clinical and economic value in the Italian setting.

  2. Tetrathiomolybdate mediates cisplatin-induced p38 signaling and EGFR degradation and enhances response to cisplatin therapy in gynecologic cancers

    Science.gov (United States)

    Kim, Kyu Kwang; Han, Alex; Yano, Naohiro; Ribeiro, Jennifer R.; Lokich, Elizabeth; Singh, Rakesh K.; Moore, Richard G.

    2015-01-01

    Cisplatin and its analogs are among the most widely used chemotherapeutic agents against various types of cancer. It is known that cisplatin can activate epidermal growth factor receptor (EGFR), which may provide a survival benefit in cancers. Tetrathiomolybdate (TM) is a potent anti-cancer and anti-angiogenic agent and has been investigated in a number of clinical trials for cancer. In this study, we explore the therapeutic potential of TM on cisplatin-mediated EGFR regulation. Our study shows that TM is not cytotoxic, but exerts an anti-proliferative effect in ECC-1 cells. However, TM treatment prior to cisplatin markedly improves cisplatin-induced cytotoxicity. TM suppressed cisplatin-induced activation of EGFR while potentiating activation of p38; the activation of p38 signaling appeared to promote cisplatin-induced EGFR degradation. These results are in contrast to what we saw when cells were co-treated with cisplatin plus an EGFR tyrosine kinase inhibitor, where receptor activation was inhibited but receptor degradation was also blocked. Our current study is in agreement with previous findings that TM may have a therapeutic benefit by inhibiting EGFR activation. We furthermore provide evidence that TM may provide an additional benefit by potentiating p38 activation following cisplatin treatment, which may in turn promote receptor degradation by cisplatin. PMID:26568478

  3. Clinical Characteristics and Outcomes of Lung Cancer Patients 
with EGFR Mutations in Exons 19 and 21

    Directory of Open Access Journals (Sweden)

    Renwang LIU

    2014-11-01

    Full Text Available Background and objective Studies on the epidermal growth factor receptor (EGFR signaling pathways and the therapeutic effects of EGFR-tyrosine kinase inhibitors (EGFR-TKIs have recently proven that targeted therapy has a major role in the treatment of lung cancer. However, the therapeutic effects of EGFR-TKIs on lung cancers with different EGFR mutation subtypes remain unclear. And if there is a significant difference in the effects of EGFR-TKIs, the mechanisms for the difference remain unclear. The aim of this study was to investigate the clinical importance of EGFR mutations in exons 19 and 21 of lung cancer patients and to compare the outcomes of these patients. Methods The study recruited 113 patients who had non-small cell lung cancer (NSCLC with EGFR mutations. EGFR mutations were detected for 47 patients using Real-time PCR or DNA sequencinag. The mutations of the remaining patients were determined using xTag-EGFR liquid chip technology. All stages I-III patients underwent radical resection followed by 4 cycles of postoperative chemotherapy. Patients with pleural metastases underwent pleural biopsy, pleurodesis, and chemotherapy only. Patients with distant metastases underwent biopsy and chemotherapy only. Collected clinical data were analyzed using SPSS 19.0 software. Results EGFR exon mutations 19 and 21 were found in 56 and 57 patients, respectively. The mean age of patients with exon 19 mutations was lower than the age of the patients with exon 21 mutations (57.02±11.31 years vs 62.25±7.76 years, respectively; P0.05 between the patients with exon 19 and 21 mutations; and survival analysis of 91 (80.5% patients with complete clinical data found no differences in overall survival. Stratification analysis found out that patients with exon 19 mutations had longer overall survival associated with age>61 years, male gender, ever smoking, and stage IV disease; although the differences were not significant. Conclusion Compared to the lung

  4. Expression of P-EGFR and P-Akt protein in esophageal squamous cell carcinoma and its prognosis.

    Science.gov (United States)

    Shan, Zheng-Zheng; Chen, Pei-Nan; Wang, Feng; Wang, Jun; Fan, Qing-Xia

    2017-09-01

    The phosphorylated epidermal growth factor receptor (P-EGFR) and phosphorylated Akt (P-Akt) protein in esophageal squamous cell carcinoma (ESCC) were studied, and its significance in clinical prognosis of patients was assessed. The expression of P-EGFR and P-Akt protein in 83 cases of ESCC and 83 normal esophageal tissues was determined by immunohistochemical staining. Log-rank test and correlation analysis were used to analyze the prognosis of ESCC. The positive expression of P-EGFR in ESCC was 88% (73/83 cases) compared with 41% in normal esophageal mucosa (34/83 cases) (PP-Akt protein expression in ESCC was 90.4% (75/83 cases), compared with 27.7% seen in normal esophageal mucosa (23/83 cases) (PP-EGFR and P-Akt protein was positively correlated with lymph node metastasis and degree of differentiation (PP>0.05). The expression of P-EGFR was positively correlated with that of P-Akt protein (r=0.674, PP-EGFR expression was negatively correlated with survival time of patients with ESCC (r=-0.526, PP-EGFR-positive cases was significantly lower than that of the P-EGFR-negative cases (PP-Akt was negatively correlated with survival in patients with ESCC (r=-0.473, PP-Akt-positive cases was significantly lower than that of the P-Akt-negative cases (PP-EGFR and P-Akt protein expression is closely related to the incidence of ESCC and mediates the development of invasive cancer and metastasis. It is used to determine the prognosis of ESCC, and may represent a new therapeutic target for the disease.

  5. Phase III study of afatinib or cisplatin plus pemetrexed in patients with metastatic lung adenocarcinoma with EGFR mutations.

    LENUS (Irish Health Repository)

    Sequist, Lecia V

    2013-09-20

    The LUX-Lung 3 study investigated the efficacy of chemotherapy compared with afatinib, a selective, orally bioavailable ErbB family blocker that irreversibly blocks signaling from epidermal growth factor receptor (EGFR\\/ErbB1), human epidermal growth factor receptor 2 (HER2\\/ErbB2), and ErbB4 and has wide-spectrum preclinical activity against EGFR mutations. A phase II study of afatinib in EGFR mutation-positive lung adenocarcinoma demonstrated high response rates and progression-free survival (PFS).

  6. Determination of beta activity in water

    Science.gov (United States)

    Barker, F.B.; Robinson, B.P.

    1963-01-01

    Many elements have one or more naturally radioactive isotopes, and several hundred other radionuclides have been produced artificially. Radioactive substances may be present in natural water as a result of geochemical processes or the release of radioactive waste and other nuclear debris to the environment. The Geological Survey has developed methods for measuring certain of these .radioactive substances in water. Radioactive substances often are present in water samples in microgram quantities or less. Therefore, precautions must be taken to prevent loss of material and to assure that the sample truly represents its source at the time of collection. Addition of acids, complexing agents, or stable isotopes often aids in preventing loss of radioactivity on container walls, on sediment, or on other solid materials in contact with the sample. The disintegration of radioactive atoms is a random process subject to established methods of statistical analysis. Because many water samples contain small amounts of radioactivity, low-level counting techniques must be used. The usual assumption that counting data follow a Gaussian distribution is invalid under these conditions, and statistical analyses must be based on the Poisson distribution. The gross beta activity in water samples is determined from the residue left after evaporation of the sample to dryness. Evaporation is accomplished first in a teflon dish, then the residue is transferred with distilled water to a counting planchet and again is reduced to dryness. The radioactivity on the planchet is measured with an anticoincidence-shielded, low-background, beta counter and is compared with measurements of a strontium-90-yttrium-90 standard prepared and measured in the same manner. Control charts are used to assure consistent operation of the counting instrument.

  7. Navigating into the binding pockets of the HER family protein kinases: discovery of novel EGFR inhibitor as antitumor agent

    Directory of Open Access Journals (Sweden)

    Liu W

    2015-07-01

    Full Text Available Wei Liu,1,* Jin-Feng Ning,2,* Qing-Wei Meng,1 Jing Hu,1 Yan-Bin Zhao,1 Chao Liu,3 Li Cai11The Fourth Department of Medical Oncology, Harbin Medical University Cancer Hospital, 2The Thoracic Surgery Department, Harbin Medical University Cancer Hospital, Harbin, People’s Republic of China; 3General Surgery Department, Mudanjiang Guanliju Central Hospital, Mishan, Heilongjiang Province, People’s Republic of China*These authors contributed equally to this workAbstract: The epidermal growth factor receptor (EGFR family has been validated as a successful antitumor drug target for decades. Known EGFR inhibitors were exposed to distinct drug resistance against the various EGFR mutants within non-small-cell lung cancer (NSCLC, particularly the T790M mutation. Although so far a number of studies have been reported on the development of third-generation EGFR inhibitors for overcoming the resistance issue, the design procedure largely depends on the intuition of medicinal chemists. Here we retrospectively make a detailed analysis of the 42 EGFR family protein crystal complexes deposited in the Protein Data Bank (PDB. Based on the analysis of inhibitor binding modes in the kinase catalytic cleft, we identified a potent EGFR inhibitor (compound A-10 against drug-resistant EGFR through fragment-based drug design. This compound showed at least 30-fold more potency against EGFR T790M than the two control molecules erlotinib and gefitinib in vitro. Moreover, it could exhibit potent HER2 inhibitory activities as well as tumor growth inhibitory activity. Molecular docking studies revealed a structural basis for the increased potency and mutant selectivity of this compound. Compound A-10 may be selected as a promising candidate in further preclinical studies. In addition, our findings could provide a powerful strategy to identify novel selective kinase inhibitors on the basis of detailed kinase–ligand interaction space in the PDB.Keywords: EGFR, kinase

  8. The epidermal growth factor receptor (EGFR / HER-1 gatekeeper mutation T790M is present in European patients with early breast cancer.

    Directory of Open Access Journals (Sweden)

    Vahid Bemanian

    Full Text Available The epidermal growth factor receptor (EGFR is one of the major oncogenes identified in a variety of human malignancies including breast cancer (BC. EGFR-mutations have been studied in lung cancer for some years and are established as important markers in guiding therapy with tyrosine kinase inhibitors (TKIs. In contrast, EGFR-mutations have been reported to be rare if not absent in human BC, although recent evidence has suggested a significant worldwide variation in somatic EGFR-mutations. Therefore, we investigated the presence of EGFR-mutations in 131 norwegian patients diagnosed with early breast cancer using real-time PCR methods. In the present study we identified three patients with an EGFR-T790M-mutation. The PCR-findings were confirmed by direct Sanger sequencing. Two patients had triple-negative BC (TNBC while the third was classified as luminal-A subtype. The difference in incidence of T790M mutations comparing the TNBC subgroup with the other BC subgroups was statistical significant (P = 0.023. No other EGFR mutations were identified in the entire cohort. Interestingly, none of the patients had received any previous cancer treatment. To our best knowledge, the EGFR-T790M-TKI-resistance mutation has not been previously detected in breast cancer patients. Our findings contrast with the observations made in lung cancer patients where the EGFR-T790M-mutation is classified as a typical "second mutation"causing resistance to TKI-therapy during ongoing anticancer therapy. In conclusion, we have demonstrated for the first time that the EGFR-T790M-mutation occurs in primary human breast cancer patients. In the present study the EGFR-T790M mutation was not accompanied by any simultaneous EGFR-activating mutation.

  9. The epidermal growth factor receptor (EGFR / HER-1) gatekeeper mutation T790M is present in European patients with early breast cancer.

    Science.gov (United States)

    Bemanian, Vahid; Sauer, Torill; Touma, Joel; Lindstedt, Bjørn Arne; Chen, Ying; Ødegård, Hilde Presterud; Vetvik, Katja Marjaana; Bukholm, Ida Rashida; Geisler, Jürgen

    2015-01-01

    The epidermal growth factor receptor (EGFR) is one of the major oncogenes identified in a variety of human malignancies including breast cancer (BC). EGFR-mutations have been studied in lung cancer for some years and are established as important markers in guiding therapy with tyrosine kinase inhibitors (TKIs). In contrast, EGFR-mutations have been reported to be rare if not absent in human BC, although recent evidence has suggested a significant worldwide variation in somatic EGFR-mutations. Therefore, we investigated the presence of EGFR-mutations in 131 norwegian patients diagnosed with early breast cancer using real-time PCR methods. In the present study we identified three patients with an EGFR-T790M-mutation. The PCR-findings were confirmed by direct Sanger sequencing. Two patients had triple-negative BC (TNBC) while the third was classified as luminal-A subtype. The difference in incidence of T790M mutations comparing the TNBC subgroup with the other BC subgroups was statistical significant (P = 0.023). No other EGFR mutations were identified in the entire cohort. Interestingly, none of the patients had received any previous cancer treatment. To our best knowledge, the EGFR-T790M-TKI-resistance mutation has not been previously detected in breast cancer patients. Our findings contrast with the observations made in lung cancer patients where the EGFR-T790M-mutation is classified as a typical "second mutation"causing resistance to TKI-therapy during ongoing anticancer therapy. In conclusion, we have demonstrated for the first time that the EGFR-T790M-mutation occurs in primary human breast cancer patients. In the present study the EGFR-T790M mutation was not accompanied by any simultaneous EGFR-activating mutation.

  10. Reticulon 3-dependent ER-PM contact sites control EGFR nonclathrin endocytosis.

    Science.gov (United States)

    Caldieri, Giusi; Barbieri, Elisa; Nappo, Gilda; Raimondi, Andrea; Bonora, Massimo; Conte, Alexia; Verhoef, Lisette G G C; Confalonieri, Stefano; Malabarba, Maria Grazia; Bianchi, Fabrizio; Cuomo, Alessandro; Bonaldi, Tiziana; Martini, Emanuele; Mazza, Davide; Pinton, Paolo; Tacchetti, Carlo; Polo, Simona; Di Fiore, Pier Paolo; Sigismund, Sara

    2017-05-12

    The integration of endocytic routes is critical to regulate receptor signaling. A nonclathrin endocytic (NCE) pathway of the epidermal growth factor receptor (EGFR) is activated at high ligand concentrations and targets receptors to degradation, attenuating signaling. Here we performed an unbiased molecular characterization of EGFR-NCE. We identified NCE-specific regulators, including the endoplasmic reticulum (ER)-resident protein reticulon 3 (RTN3) and a specific cargo, CD147. RTN3 was critical for EGFR/CD147-NCE, promoting the creation of plasma membrane (PM)-ER contact sites that were required for the formation and/or maturation of NCE invaginations. Ca2+ release at these sites, triggered by inositol 1,4,5-trisphosphate (IP3)-dependent activation of ER Ca2+ channels, was needed for the completion of EGFR internalization. Thus, we identified a mechanism of EGFR endocytosis that relies on ER-PM contact sites and local Ca2+ signaling. Copyright © 2017, American Association for the Advancement of Science.

  11. Epidermal to Mesenchymal Transition and Failure of EGFR-Targeted Therapy in Glioblastoma

    Energy Technology Data Exchange (ETDEWEB)

    Pala, Andrej; Karpel-Massler, Georg [Department of Neurosurgery, University of Ulm School of Medicine, Steinhövelstrasse 9, Ulm D-89077 (Germany); Kast, Richard Eric [Department of Psychiatry, University of Vermont, 22 Church Street, Burlington, VT 05401 (United States); Wirtz, Christian Rainer; Halatsch, Marc-Eric, E-mail: marc-eric.halatsch@uniklinik-ulm.de [Department of Neurosurgery, University of Ulm School of Medicine, Steinhövelstrasse 9, Ulm D-89077 (Germany)

    2012-05-08

    Glioblastoma multiforme (GBM), the most common primary brain tumor in adults, is almost never curable with the current standard treatment consisting of surgical resection, irradiation and temozolomide. The prognosis remains poor despite undisputable advances in the understanding of this tumor’s molecular biology and pathophysiology, which unfortunately has so far failed to translate into a meaningful clinical benefit. Dysregulation and a resulting prominent pathophysiological role of the epidermal growth factor receptor (EGFR) have been identified in several different malignant tumor entities, GBM among them. The EGFR is overexpressed in about 40% of GBM cases, and half of these coexpress a mutant, constitutively activated subtype, EGFRvIII. Unfortunately, recent trials studying with therapeutic approaches targeted against the EGFR and EGFRvIII have failed to meet expectations, with only a minority of patients responding despite evidence of good in vitro and rodent model activity. Having potentially high relevance within this context, epithelial to mesenchymal transition (EMT) is a phenomenon associated with early stages of carcinogenesis, cancer invasion and recurrence. During EMT, epithelial cells lose many of their epithelial characteristics, prominently E-cadherin expression, and acquire properties that are typical for mesenchymal cells such as the expression of vimentin. Epithelial to mesenchymal transition has been specifically demonstrated in GBM. In this review, we summarize the evidence that EMT may precipitate GBM resistance to EGFR-targeted therapy, and may thus be among the principal factors contributing to the clinical failure of targeted therapy against EGFR and EGFRvIII.

  12. Expressions of c-Cbl, Cbl-b and EGFR and Its Role of Prognosis in NSCLC

    Directory of Open Access Journals (Sweden)

    Xin JIAO

    2011-06-01

    Full Text Available Background and objective Epidermal growth factor receptor (EGFR is closely correlated with the progression of lung cancer. Its activity is modulated by Casitas B-lineage lymphoma (Cbl family. The aim of this study is to investigate the expression and clinical relevance of c-Cbl, Cbl-b and EGFR in non-small cell lung cancer (NSCLC. Methods Expressions of c-Cbl, Cbl-b and EGFR protein were detected with tissue microarrays and immunohistochemistry technique in 94 cases of NSCLC. The correlations between the expression of the three proteins and clinicopathological parameters were analyzed. Results The positive expression rates of EGFR, c-Cbl and Cbl-b were 60.6% (57/94, 30.9% (29/94 and 84.0% (79/94, respectively. The expression of EGFR, c-Cbl and Cbl-b was not associated with age, pathological type, TNM stage, lymph node metastasis, and smoking history. c-Cbl and Cbl-b status was not significantly correlated with overall survival. Subgroup analyses showed that c-Cbl-positive patients had longer survival than c-Cbl-negative patients in EGFR-positive group (P=0.014. Conclusion Detection of c-Cbl protein levels might contribute to the prognosis evaluation of EGFR-positive NSCLC.

  13. Modification of cytokine-induced killer cells with chimeric antigen receptors (CARs) enhances antitumor immunity to epidermal growth factor receptor (EGFR)-positive malignancies.

    Science.gov (United States)

    Ren, Xuequn; Ma, Wanli; Lu, Hong; Yuan, Lei; An, Lei; Wang, Xicai; Cheng, Guanchang; Zuo, Shuguang

    2015-12-01

    Epidermal growth factor receptor (EGFR, ErbB1, Her-1) is a cell surface molecule overexpressing in a variety of human malignancies and, thus, is an excellent target for immunotherapy. Immunotherapy targeting EGFR-overexpressing malignancies using genetically modified immune effector cells is a novel and promising approach. In the present study, we have developed an adoptive cellular immunotherapy strategy based on the chimeric antigen receptor (CAR)-modified cytokine-induced killer (CAR-CIK) cells specific for the tumor cells expressing EGFR. To generate CAR-CIK cells, a lentiviral vector coding the EGFR-specific CAR was constructed and transduced into the CIK cells. The CAR-CIK cells showed significantly enhanced cytotoxicity and increased production of cytokines IFN-γ and IL-2 when co-cultured with EGFR-positive cancer cells. In tumor xenografts, adoptive immunotherapy of CAR-CIK cells could inhibit tumor growth and prolong the survival of EGFR-overexpressing human tumor xenografts. Moreover, tumor growth inhibition and prolonged survival in mice with EGFR(+) human cancer were associated with the increased persistence of CAR-CIK cells in vivo. Our study indicates that modification with EGFR-specific CAR strongly enhances the antitumor activity of the CIK cells against EGFR-positive malignancies.

  14. Detection of EGFR mutations in plasma and biopsies from non-small cell lung cancer patients by allele-specific PCR assays.

    Science.gov (United States)

    Weber, Britta; Meldgaard, Peter; Hager, Henrik; Wu, Lin; Wei, Wen; Tsai, Julie; Khalil, Azza; Nexo, Ebba; Sorensen, Boe S

    2014-04-28

    Lung cancer patients with mutations in the epidermal growth factor receptor (EGFR) are primary candidates for EGFR-targeted therapy. Reliable analyses of such mutations have previously been possible only in tumour tissue. Here, we demonstrate that mutations can be detected in plasma samples with allele-specific PCR assays. Pairs of the diagnostic biopsy and plasma obtained just prior to start of erlotinib treatment were collected from 199 patients with adenocarcinoma of non-small-cell lung cancer. DNA from both sample types was isolated and examined for the presence of mutations in exons 18-21 of the EGFR gene, employing the cobas(®) EGFR Tissue Test and cobas(®) EGFR Blood Test (in development, Roche Molecular Systems, Inc., CA, USA). Test results were obtained in all 199 (100%) plasma samples and 196/199 (98%) of the biopsies. EGFR-activating mutations were identified in 24/199 (12%) plasma samples and 28/196 (14%) biopsy samples, and 17/196 (9%) matched pairs contained the same mutation. Six EGFR mutations were present only in plasma samples but not in the biopsy samples. The overall concordance of the EGFR gene mutations detected in plasma and biopsy tissue was 179/196 (91%) (kappa value: 0.621). Mutational analysis of the EGFR gene in plasma samples is feasible with allele-specific PCR assays and represents a non-invasive supplement to biopsy analysis. M-20080012 from March 10, 2008 and reported to ClinicalTrials.gov: NCT00815971.

  15. EGFR and VEGFR as potential target for biological therapies in HCC cells.

    Science.gov (United States)

    Giannelli, Gianluigi; Sgarra, Concetta; Porcelli, Letizia; Azzariti, Amalia; Antonaci, Salvatore; Paradiso, Angelo

    2008-04-18

    Hepatocellular carcinoma (HCC) is a highly malignant cancer with poor prognosis. Inhibitors of EGFR and VEGFR for HCC treatment are currently under investigation. Gefitinib and vandetanib inhibit migration of HCC cells on Laminin-5 and Fibronectin, and invasion through matrigel. Both drugs inhibit p-EGFR after short time, while their efficacy on p-Erk1/2 and p-Akt is progressive and stable over time. PI3K/Akt and MEK/Erk1/2 inhibitors, inhibit migration and invasion as well as inducing de-phosphorylation of downstream effectors. Finally, both inhibitors, vandetanib and gefitinib down-regulated the secretion of matrix metalloproteases MMP-2 and MMP-9. All these biological effects seem to depend on the activity of gefitinib and vandetanib blocking activity towards p-EGFR mediated pathways.

  16. High specificity but low sensitivity of mutation-specific antibodies against EGFR mutations in non-small-cell lung cancer

    DEFF Research Database (Denmark)

    Bondgaard, Anna-Louise; Høgdall, Estrid; Mellemgaard, Anders

    2014-01-01

    Determination of epidermal growth factor receptor (EGFR) mutations has a pivotal impact on treatment of non-small-cell lung cancer (NSCLC). A standardized test has not yet been approved. So far, Sanger DNA sequencing has been widely used. Its rather low sensitivity has led to the development......, and staining score (multipum of intensity (graded 0-3) and percentages (0-100%) of stained tumor cells) was calculated. Positivity was defined as staining score >0. Specificity of exon19 antibody was 98.8% (95% confidence interval=95.9-99.9%) and of exon21 antibody 97.8% (95% confidence interval=94...... positive (immunohistochemistry positive, RT-PCR negative). One false positive exon21 mutation had staining score 300. The EGFR variantIII antibody showed no correlation to EGFR mutation status determined by RT-PCR or to EGFR immunohistochemistry. High specificity of the mutation-specific antibodies...

  17. Determining Sample Size for Research Activities

    Science.gov (United States)

    Krejcie, Robert V.; Morgan, Daryle W.

    1970-01-01

    A formula for determining sample size, which originally appeared in 1960, has lacked a table for easy reference. This article supplies a graph of the function and a table of values which permits easy determination of the size of sample needed to be representative of a given population. (DG)

  18. Inhibition of tumor growth by targeted anti-EGFR/IGF-1R Nanobullets depends on efficient blocking of cell survival pathways

    NARCIS (Netherlands)

    van der Meel, Roy; Oliveira, Sabrina; Altintas, Isil; Heukers, R.; Pieters, Ebel H.E.; van Bergen en Henegouwen, Paul M.P.; Storm, Gerrit; Hennink, Wim E.; Kok, Robbert J.; Schiffelers, Raymond M.

    2013-01-01

    The clinical efficacy of epidermal growth factor receptor (EGFR)-targeted inhibitors is limited due to resistance mechanisms of the tumor such as activation of compensatory pathways. Crosstalk between EGFR and insulin-like growth factor 1 (IGF-1R) signaling has been frequently described to be

  19. Detection and Analysis of EGFR and KRAS Mutations 
in the Patients with Lung Squamous Cell Carcinomas

    Directory of Open Access Journals (Sweden)

    Hui ZHANG

    2015-10-01

    Full Text Available Background and objective Activating mutations in epidermal growth factor receptor (EGFR and KRAS are important markers in non-small cell lung cancer. However, EGFR and KRAS gene mutations in lung squamous cell carcinoma are rarely reported. The aim of this study was to analyze EGFR and KRAS gene mutation rate and their relationship with clinical features in patients with lung squamous cell carcinomas. Methods A total of 139 patients undergoing treatment for naïve lung squamous cell carcinomas with tumor tissue samples available for testing were recruited. EGFR and KRAS mutation statuses of the tumor samples were detected using a mutant enriched liquid chip. Results Of the 139 cases of lung squamous cell carcinoma, EGFR mutations were detected in 25 cases (18%, KRAS mutations were detected in 7 cases (5%, and the presence of both EGFR and KRAS mutations was detected in 1 case (0.7%. EGFR mutations occurred more often in females than in males (33.3% vs 16.5% and in patients that never smoked than in those who smoke (29.6% vs 16.1%. However, the difference did not reach statistical significance (P>0.05. No significant differences were observed in age, stage, and different biopsy type. KRAS mutations occurred more often in males than in females (5.5% vs 0%, but the difference did not reach statistical significance (P>0.05. No significant differences were observed in age, stage, different biopsy type, and smoking status (P>0.05. Conclusion EGFR and KRAS mutations were low in lung squamous cell carcinomas, and had no significant correlation with clinical features. Before using tyrosine kinase inhibitor targeted therapy, EGFR and KRAS mutations should be detected in patients with lung squamous cell carcinomas.

  20. Frequency of EGFR mutations in non-small cell lung cancer patients: screening data from West Siberia.

    Science.gov (United States)

    Gervas, Polina; Ivanova, Anna; Vasiliev, Nikolay; Ananina, Olga; Zharkova, Olga; Rogovieva, Olga; Verzhbitskaya, Natalia; Didichuk, Ivan; Cheremisina, Olga; Popova, Natalia; Goldberg, Victor; Cherdyntsev, Evgeny; Choynzonov, Evgeny; Cherdyntseva, Nadezda

    2015-01-01

    Incorporation of molecular analysis of the epidermal growth factor receptor (EGFR) gene into routine clinical practice has shown great promise to provide personalized therapy of the non-small cell lung cancer (NSCLC) in the developed world. However, the genetic testing of EGFR mutations has not yet become routine clinical practice in territories remote from the central regions of Russia. Therefore, we aimed to study the frequency of major types of activating mutations of the EGFR gene in NSCLC patients residing in West Siberia. We examined EGFR mutations in exons 19 and 21 in 147 NSCLC patients (excluding squamous cell lung carcinomas) by real time polymerase chain reaction. EGFR mutations were detected in 28 of the 147 (19%) patients. There were 19 (13%) cases with mutations in exon 19 and 9 cases (6%) in exon 21. Mutations were more frequently observed in women (42%, p=0.000) than in men (1%). A significantly higher incidence of EGFR mutations was observed in bronchioloalveolar carcinomas (28%, p=0.019) and in adenocarcinomas (21%, p=0.024) than in large cell carcinomas, mixed adenocarcinomas, and NOS (4%). The EGFR mutation rate was much higher in never-smokers than in smokers: 38% vs. 3% (p=0.000). The frequency of EGFR mutations in the Kemerovo and Tomsk regions was 19%. The incorporation of molecular analysis of the EGFR gene into routine clinical practice will allow clinicians to provide personalised therapy, resulting in a significant increase in survival rates and improvement in life quality of advanced NSCLC patients.

  1. Management of acquired resistance to EGFR TKI-targeted therapy in advanced non-small cell lung cancer.

    Science.gov (United States)

    Wu, Shang-Gin; Shih, Jin-Yuan

    2018-02-19

    Recent advances in diagnosis and treatment are enabling a more targeted approach to treating lung cancers. Therapy targeting the specific oncogenic driver mutation could inhibit tumor progression and provide a favorable prognosis in clinical practice. Activating mutations of epidermal growth factor receptor (EGFR) in non-small cell lung cancer (NSCLC) are a favorable predictive factor for EGFR tyrosine kinase inhibitors (TKIs) treatment. For lung cancer patients with EGFR-exon 19 deletions or an exon 21 Leu858Arg mutation, the standard first-line treatment is first-generation (gefitinib, erlotinib), or second-generation (afatinib) TKIs. EGFR TKIs improve response rates, time to progression, and overall survival. Unfortunately, patients with EGFR mutant lung cancer develop disease progression after a median of 10 to 14 months on EGFR TKI. Different mechanisms of acquired resistance to first-generation and second-generation EGFR TKIs have been reported. Optimal treatment for the various mechanisms of acquired resistance is not yet clearly defined, except for the T790M mutation. Repeated tissue biopsy is important to explore resistance mechanisms, but it has limitations and risks. Liquid biopsy is a valid alternative to tissue re-biopsy. Osimertinib has been approved for patients with T790M-positive NSCLC with acquired resistance to EGFR TKI. For other TKI-resistant mechanisms, combination therapy may be considered. In addition, the use of immunotherapy in lung cancer treatment has evolved rapidly. Understanding and clarifying the biology of the resistance mechanisms of EGFR-mutant NSCLC could guide future drug development, leading to more precise therapy and advances in treatment.

  2. Delphinidin reduces cell proliferation and induces apoptosis of non-small-cell lung cancer cells by targeting EGFR/VEGFR2 signaling pathways.

    Directory of Open Access Journals (Sweden)

    Harish Chandra Pal

    Full Text Available Epidermal growth factor receptor (EGFR and vascular endothelial growth factor receptor 2 (VEGFR2 have emerged as two effective clinical targets for non-small-cell lung cancer (NSCLC. In the present study, we found that delphinidin, an anthocyanidin, present in pigmented fruits and vegetables, is a potent inhibitor of both EGFR and VEGFR2 in NSCLC cells that overexpress EGFR/VEGFR2. Using these cells, we next determined the effects of delphinidin on cell growth and apoptosis in vitro and on tumor growth and angiogenesis in vivo. Delphinidin (5-60 µM treatment of NSCLC cells inhibited the activation of PI3K, and phosphorylation of AKT and MAPKs. Additionally, treatment of NSCLC cells with delphinidin resulted in inhibition of cell growth without having significant toxic effects on normal human bronchial epithelial cells. Specifically, treatment of NCI-H441 and SK-MES-1 cells with delphindin (5-60 µM resulted in (i cleavage of PARP protein, (ii activation of caspase-3 and -9, (iii downregulation of anti-apoptotic proteins (Bcl2, Bcl-xL and Mcl-1, (iv upregulation of pro-apoptotic proteins (Bax and Bak, and (v decreased expression of PCNA and cyclin D1. Furthermore, in athymic nude mice subcutaneously implanted with human NSCLC cells, delphinidin treatment caused a (i significant inhibition of tumor growth, (ii decrease in the expression of markers for cell proliferation (Ki67 and PCNA and angiogenesis (CD31 and VEGF, and (iii induction of apoptosis, when compared with control mice. Based on these observations, we suggest that delphinidin, alone or as an adjuvant to current therapies, could be used for the management of NSCLC, especially those that overexpress EGFR and VEGFR2.

  3. Genetic deletion of the EGFR ligand epigen does not affect mouse embryonic development and tissue homeostasis.

    Science.gov (United States)

    Dahlhoff, Maik; Schäfer, Matthias; Wolf, Eckhard; Schneider, Marlon R

    2013-02-15

    The epidermal growth factor receptor (EGFR) is a tyrosine kinase receptor with manifold functions during development, tissue homeostasis and disease. EGFR activation, the formation of homodimers or heterodimers (with the related ERBB2-4 receptors) and downstream signaling is initiated by the binding of a family of structurally related growth factors, the EGFR ligands. Genetic deletion experiments clarified the biological function of all family members except for the last characterized ligand, epigen. We employed gene targeting in mouse embryonic stem cells to generate mice lacking epigen expression. Loss of epigen did not affect mouse development, fertility, or organ physiology. Quantitative RT-PCR analysis revealed increased expression of betacellulin and EGF in a few organs of epigen-deficient mice, suggesting a functional compensation by these ligands. In conclusion, we completed the genetic analysis of EGFR ligands and show that epigen has non-essential functions or functions that can be compensated by other EGFR ligands during growth and tissue homeostasis. Copyright © 2012 Elsevier Inc. All rights reserved.

  4. Individualized therapies in colorectal cancer: KRAS as a marker for response to EGFR-targeted therapy

    Directory of Open Access Journals (Sweden)

    Li Kuiyuan

    2009-04-01

    Full Text Available Abstract Individualized therapies that are tailored to a patient's genetic composition will be of tremendous value for treatment of cancer. Recently, Kirsten ras (KRAS status has emerged as a predictor of response to epidermal growth factor receptor (EGFR targeted therapies. In this article, we will discuss targeted therapies for colorectal cancers (CRC based on EGFR signaling pathway and review published data about the potential usefulness of KRAS as a biological marker for response to these therapies. Results from relevant studies published since 2005 and unpublished results presented at national meetings were retrieved and summarized. These studies reflected response (or lack of response to EGFR-targeted therapies in patients with metastatic CRC as a function of KRAS status. It has become clear that patients with colorectal cancer whose tumor has an activating mutation in KRAS do not respond to monoclonal antibody therapies targeting EGFR. It should now become a standard practice that any patients being considered for EGFR targeted therapies have their tumors tested for KRAS status and only those with wild-type KRAS being offered such therapies.

  5. Concurrent EGFR Mutation and ALK Translocation in Non-Small Cell Lung Cancer.

    Science.gov (United States)

    Sweis, Randy F; Thomas, Sachdev; Bank, Bruce; Fishkin, Paul; Mooney, Colin; Salgia, Ravi

    2016-02-26

    Epidermal growth factor receptor (EGFR) mutations and anaplastic large-cell lymphoma kinase (ALK) rearrangements are now routine biomarkers that have been incorporated into the practice of managing non-small cell lung cancer (NSCLC). Historically, the two molecular alterations have been viewed as mutually exclusive, but recent identified cases suggest otherwise. In this report, we describe cases of lung cancer with concurrent EGFR mutation and ALK rearrangement and identify their clinical characteristics. Non-small cell lung cancer patients with multiple molecular alterations were retrospectively analyzed from an academic referral center from 2011-2013. An additional review was conducted of reported cases with dual alterations. Four cases of NSCLC with alterations in both EGFR and ALK were identified and evaluated with 16 published cases for a total of 20 cases. The age of patients ranged from 37 to 77 years. Nine patients were never smokers. The disease control rates in patients treated with EGFR inhibitors and ALK inhibitors were 46% (6/13) and 71% (5/7), respectively. This series highlights the importance of comprehensive molecular profiling of newly diagnosed lung cancer, as NSCLC may be driven by concurrent molecular alterations. EGFR- and ALK-targeted therapies appear to have modest activity in patients with tumors possessing both alterations. Dual-altered NSCLC patients may have distinct clinical characteristics warranting further study. Combination targeted therapy or novel multi-targeted tyrosine kinase inhibitors may prove important in these patients, though necessary studies remain ongoing.

  6. Chromosome 7 Multiplication in EGFR-positive Lung Carcinomas Based on Tissue Microarray Analysis.

    Science.gov (United States)

    Tsiambas, Evangelos; Mastronikolis, Nicholas S; Lefas, Alicia Y; Georgiannos, Stavros N; Ragos, Vasileios; Fotiades, Panagiotis P; Tsoukalas, Nikolaos; Kavantzas, Nikolaos; Karameris, Andreas; Peschos, Dimitrios; Patsouris, Efstratios; Syrigos, Konstantinos

    2017-01-01

    Epidermal growth factor receptor (EGFR) over-activation is observed in significant proportions of non-small cell lung carcinomas (NSCLC). Our aim was to investigate the role of chromosome 7 multiplication with regard to its influence in EGFR expression, combined or not with gene amplification. Using tissue microarray technology, fifty (n=50) primary NSCLCs were cored and re-embedded into the final recipient block. Immunohistochemistry (IHC) and also chromogenic in situ hybridization (CISH) were performed. EGFR expression at any level was detected in 40/50 (80%) cores. Over-expression was observed in 23/40 (57.5%) cases. Gene amplification was identified in 11/50 (22%) cases whereas chromosome 7 polysomy in 8/50 (16%) cases. Pure chromosome 7 multiplication alone led to low or moderate levels of expression. Overall EGFR expression was correlated with gene (p=0.001) and interestingly with chromosome 7 centromere numerical imbalances (p=0.004). EGFR expression is associated not only with amplification, but also with chromosome 7 centromere multiple copies. Chromosome 7 multiplication -due to centromere region amplification or true polysomy- is critical for applying monoclonal antibody targeted therapeutic strategies excluding the pure non-amplified cases. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

  7. EGFR Mutation Status in Uighur Lung Adenocarcinoma Patients

    Directory of Open Access Journals (Sweden)

    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%.

  8. [EGFR-expression in pulmonary neuroendocrine cell hyperplasia].

    Science.gov (United States)

    Kuhnen, C; Winter, B U

    2006-03-01

    15 cases of pulmonary neuroendocrine cell hyperplasia (carcinoid-tumorlets, diffuse idiopathic pulmonary neuroendocrine cell hyperplasia/DIPNECH) and 20 neuroendocrine pulmonary tumors (10 carcinoid tumors, 5 large cell neuroendocrine, and 5 small cell neuroendocrine lung carcinomas) were immunohistochemically analyzed for the expression of epidermal growth factor receptor (EGFR, = HER-1). All cases of neuroendocrine cell hyperplasia exhibited a maximum EGFR expression (score 3 in 100% of cells) showing predominantly membranous, partly cytoplasmic staining. 4 ot the 10 carcinoid tumors were strongly positive for EGFR, whereas the other 6 were EGFR-negative. A total of 90% of large cell neuroendocrine and small cell neuroendocrine carcinomas were negative for EGFR. Overexpression of EGFR in pulmonary neuroendocrine cell hyperplasia might be significant for the pathogenesis of these lesions. As DIPNECH is characterized by clinical signs and symptoms including mild cough and obstructive functional impairment, a specific antagonistic therapeutic trial could aim at blocking EGFR/HER-1 or its subsequent signal transduction pathway.

  9. EGFR intragenic loss and gene amplification in astrocytic gliomas.

    Science.gov (United States)

    Arjona, Dolores; Bello, M Josefa; Rey, Juan A

    2006-01-01

    We have studied EGFR gene amplification and allelic status of chromosome 7 in 68 tumors consisting of 34 WHO grade IV glioblastomas (26 primary and 8 secondary), 14 WHO grade III anaplastic astrocytomas, and 20 WHO grade II astrocytomas, by polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP), quantitative PCR, and microsatellite analysis. EGFR gene amplification was present in 27 of these tumors (40%), and we identified allelic losses at 7p11 approximately p14 in 38 of the 68 cases (56%), including 17 tumors displaying loss for EGFR intragenic markers. The positive correlation (P < 0.05, chi(2)) between tumors with EGFR intragenic loss and EGFR gene amplification, frequently displaying the EGFR vIII form, suggests that EGFR gene rearrangement leading to intragenic loss is a molecular event that participates in the amplification process of this gene.

  10. Inhibition of EGFR/MAPK signaling reduces microglial inflammatory response and the associated secondary damage in rats after spinal cord injury

    Directory of Open Access Journals (Sweden)

    Qu Wen-sheng

    2012-07-01

    Full Text Available Abstract Background Emerging evidence indicates that reactive microglia-initiated inflammatory responses are responsible for secondary damage after primary traumatic spinal cord injury (SCI; epidermal growth factor receptor (EGFR signaling may be involved in cell activation. In this report, we investigate the influence of EGFR signaling inhibition on microglia activation, proinflammatory cytokine production, and the neuronal microenvironment after SCI. Methods Lipopolysaccharide-treated primary microglia/BV2 line cells and SCI rats were used as model systems. Both C225 and AG1478 were used to inhibit EGFR signaling activation. Cell activation and EGFR phosphorylation were observed after fluorescent staining and western blot. Production of interleukin-1beta (IL-1β and tumor necrosis factor alpha (TNFα was tested by reverse transcription PCR and ELISA. Western blot was performed to semi-quantify the expression of EGFR/phospho-EGFR, and phosphorylation of Erk, JNK and p38 mitogen-activated protein kinases (MAPK. Wet-dry weight was compared to show tissue edema. Finally, axonal tracing and functional scoring were performed to show recovery of rats. Results EGFR phosphorylation was found to parallel microglia activation, while EGFR blockade inhibited activation-associated cell morphological changes and production of IL-1β and TNFα. EGFR blockade significantly downregulated the elevated MAPK activation after cell activation; selective MAPK inhibitors depressed production of cytokines to a certain degree, suggesting that MAPK mediates the depression of microglia activation brought about by EGFR inhibitors. Subsequently, seven-day continual infusion of C225 or AG1478 in rats: reduced the expression of phospho-EGFR, phosphorylation of Erk and p38 MAPK, and production of IL-1β and TNFα; lessened neuroinflammation-associated secondary damage, like microglia/astrocyte activation, tissue edema and glial scar/cavity formation; and enhanced axonal

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

    DEFF Research Database (Denmark)

    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...

  12. DETERMINATION OF PHYSICAL ACTIVITY AMONG YOUNG ADULTS

    Directory of Open Access Journals (Sweden)

    Songul A. VAIZOÐLU

    2004-08-01

    Full Text Available Introduction: The physical activities have changed and decreased as the technological improvements increase. Physical inactivity is one of the most important public health problems in the last several decades. Materials and methods: This cross-sectional study is conducted in the 1. grade students of Kaya Bayazitoglu High School by using “Physical Activity Questionnnaire Form” under observation in April 2003. Participation rate is 95.8 %. SPSS 11.0 version (Statistical Package for Social Sciences statistical programme was used for entrance and analysis of the data. Results: 50,4% of the participants were female and 49,6% were male. Mean age was 15,21 ± 0,59. The mean of the energy spent by the participants was 1779,67 ± 2539.86 kilocalories/day and the the mean MET/week spent by the physical activities was 47,32 ± 68,08. In conclusion 26,0 % of the participants were found to be sedentary. 35,7 % of the females and 16,2 % of the males were sedentary. The energy spent by the males by physical activity weekly was statisticaly higher than that of the females (2 = 11,615, p = 0,001. Also the energy spent by the licenced sportsmen weekly by physical activity was statisticaly higher than that of the students who are not sportsmen (Fisher Exact, p = 0,037 Conclusions and recommendation: The physical activity of the participants was found to be low. Health and educational associations, schools and municipalities have to colloborate in increasing the physical activity of this age group. [TAF Prev Med Bull 2004; 3(4.000: 63-71

  13. [Study on the correlation between EGFR-STAT3 signal pathway and laryngeal papilloma].

    Science.gov (United States)

    Wang, Xinhua; Sun, Jingwu

    2009-09-01

    To explore the relationship between the expression of EGFR and STAT3 in human laryngeal papilloma and its biological behavior. Reverse transcription polymerase chain reaction(RT-PCR), immunohistochemical staining and Western blot were used to evaluate the mRNA and protein expression of EGFR and STAT3 (p-STAT3) in 42 laryngeal papilloma tissues and 15 samples of normal laryngeal tissue, and the relationship between the protein expression of them and clinic pathological parameters was also analyzed. The mRNA expression levels of EGFR and STAT3 in laryngeal papilloma tissue were significantly higher than that in normal laryngeal tissue (P laryngeal papilloma than normal laryngeal tissue by immunohistochemistry and western blot (P laryngeal papilloma (P laryngeal papilloma (P laryngeal papilloma,, and the persistent activation of STAT3 gene plays an important role in the recurrence and canceration of laryngeal papilloma.

  14. CHIP is a novel tumor suppressor in pancreatic cancer and inhibits tumor growth through targeting EGFR

    Science.gov (United States)

    Wang, Tianxiao; Yang, Jingxuan; Xu, Jianwei; Li, Jian; Cao, Zhe; Zhou, Li; You, Lei; Shu, Hong; Lu, Zhaohui; Li, Huihua; Li, Min; Zhang, Taiping; Zhao, Yupei

    2014-01-01

    Carboxyl terminus of heat shock protein 70-interacting protein (CHIP) is an E3 ubiquitin ligase that is involved in protein quality control and mediates several tumor-related proteins in many cancers, but the function of CHIP in pancreatic cancer is not known. Here we show that CHIP interacts and ubiquitinates epidermal growth factor receptor (EGFR) for proteasome-mediated degradation in pancreatic cancer cells, thereby inhibiting the activation of EGFR downstream pathways. CHIP suppressed cell proliferation, anchor-independent growth, invasion and migration, as well as enhanced apoptosis induced by erlotinib in vitro and in vivo. The expression of CHIP was decreased in pancreatic cancer tissues or sera. Low CHIP expression in tumor tissues was correlated with tumor differentiation and shorter overall survival. These observations indicate that CHIP serves as a novel tumor suppressor by down-regulating EGFR pathway in pancreatic cancer cells, decreased expression of CHIP was associated with poor prognosis in pancreatic cancer. PMID:24722501

  15. Synergistic antiproliferative and antiangiogenic effects of EGFR and mTOR inhibitors.

    Science.gov (United States)

    Porcelli, L; Quatrale, A E; Mantuano, P; Silvestris, N; Rolland, J F; Biancolillo, L; Paradiso, A; Azzariti, A

    2013-01-01

    Single-agent therapy with molecularly targeted agents has shown limited success in tumor growth control, mainly because escape or resistance mechanisms are activated once a signalling molecule is inhibited. Rational combinations of target-specific agents could counteract this response providing a useful strategy in cancer treatment. In this regard, the EGFR and mTOR inhibitors have been used together to generate a synergistic effect and maximize the efficacy of each individual agent. Overall, the in vivo and in vitro evidences support the utilization of combinations targeting EGFR and mTOR, for malignancies characterized by deregulated EGFR/PI3K/Akt/ mTOR signalling cascade; whereas the clinical experience points out that the assessment of the therapeutic value of such combination awaits further investigations.

  16. Lung adenocarcinoma patients of young age have lower EGFR mutation rate and poorer efficacy of EGFR tyrosine kinase inhibitors

    Directory of Open Access Journals (Sweden)

    Shang-Gin Wu

    2017-07-01

    Full Text Available Patients aged ≤50 years are rarely diagnosed with nonsmall cell lung cancer. We conducted a retrospective cohort study to understand the mutation status of EGFR and the efficacy of epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI treatment in young Asian patients with lung adenocarcinoma. We collected tumour specimens and malignant pleural effusions from lung adenocarcinoma patients from June 2005 to April 2014, recorded their clinical demographic data, and analysed EGFR mutations by reverse transcriptase PCR. EGFR mutation data were collected from 1039 lung adenocarcinoma patients, including 161 patients aged ≤50 years and 878 patients aged >50 years. Fewer patients aged ≤50 years had EGFR mutations than older patients (p=0.043, but they showed a higher rate of uncommon EGFR mutations (p=0.035. A total of 524 patients with EGFR mutations received EGFR-TKI treatment, including 81 patients aged ≤50 years. Younger patients had a lower response rate than older patients (p=0.038 and had the shortest progression-free survival compared with other predefined age categories (p=0.033. Multivariate analysis of overall survival revealed age ≤50 years as a poor prognostic factor. In conclusion, fewer Asian patients aged ≤50 years had EGFR mutations, but the EGFR mutation types were more uncommon. Age ≤50 years is associated with poorer efficacy of EGFR-TKI treatment.

  17. Phase I-IIa study of BMS-690514, an EGFR, HER-2 and -4 and VEGFR-1 to -3 oral tyrosine kinase inhibitor, in patients with advanced or metastatic solid tumours.

    Science.gov (United States)

    Soria, Jean-Charles; Baselga, José; Hanna, Nasser; Laurie, Scott A; Bahleda, Rastislav; Felip, Enriqueta; Calvo, Emiliano; Armand, Jean-Pierre; Shepherd, Frances A; Harbison, Christopher T; Berman, David; Park, Jong-Soon; Zhang, Steven; Vakkalagadda, Blisse; Kurland, John F; Pathak, Ashutosh K; Herbst, Roy S

    2013-05-01

    BMS-690514 is a potent, reversible oral inhibitor of epidermal growth factor receptor (EGFR/HER-1), HER-2 and -4, and vascular endothelial growth factor receptors (VEGFRs)-1 to -3 offering targeted inhibition of tumour growth and vascularisation in a single agent. This phase I-IIa study was designed to identify the maximum tolerated dose (MTD) and assess safety, antitumour activity, pharmacokinetics and pharmacodynamics of BMS-690514. In phase I, patients with advanced solid tumours received escalating doses of once-daily BMS-690514. In phase IIa, erlotinib-naïve (cohort A) or erlotinib-resistant (cohort B) patients with advanced non-small-cell lung cancer (NSCLC) received BMS-690514 once-daily at the MTD. In phase I (n=28), the MTD was determined to be 200mg daily. BMS-690514 was rapidly absorbed and highly metabolised after repeated oral administration with minimum drug accumulation. In phase IIa (n=62), the most frequent treatment-related adverse events were diarrhoea and acneiform rash. Adverse events that led to >1 discontinuation were diarrhoea (n=4; 4%) and rash (n=2; 2%). Disease control (≥4months) and objective response rates, respectively, were 43.3% and 3.3% (cohort A) and 22.6% and 3.2% (cohort B). Six of 21 (29%) NSCLC patients with wild-type EGFR achieved disease control versus seven of 10 (70%) patients with EGFR mutations (including T790M). At MTD, BMS-690514 modulated pharmacodynamic biomarkers associated with inhibition of VEGFR- and EGFR-signalling pathways. This phase I-IIa study suggests that BMS-690514 has manageable safety profile and antitumour activity in patients with NSCLC at 200mg/d, including those with EGFR mutations conferring resistance to erlotinib. Copyright © 2013 Elsevier Ltd. All rights reserved.

  18. Graphene-induced apoptosis in lung epithelial cells through EGFR

    Science.gov (United States)

    Tsai, Shih-Ming; Bangalore, Preeti; Chen, Eric Y.; Lu, David; Chiu, Meng-Hsuen; Suh, Andrew; Gehring, Matthew; Cangco, John P.; Garcia, Santiago G.; Chin, Wei-Chun

    2017-07-01

    Expanding interest in nanotechnology applied to electronic and biomedical fields has led to fast-growing development of various nanomaterials. Graphene is a single-atom thick, two-dimensional sheet of hexagonally arranged carbon atoms with unique physical and chemical properties. Recently, graphene has been used in many studies on electronics, photonics, composite materials, energy generation and storage, sensors, and biomedicine. However, the current health risk assessment for graphene has been relatively limited and inconclusive. This study evaluated the toxicity effects of graphene on the airway epithelial cell line BEAS-2B, which represents the first barrier of the human body to interact with airborne graphene particles. Our result showed that graphene can induce the cellular Ca2+ by phospholipase C (PLC) associated pathway by activating epidermal growth factor receptor (EGFR). Subsequently, inositol 1,4,5-triphosphate (IP3) receptors activate the release of Ca2+ from the endoplasmic reticulum (ER) Ca2+ stores. Those Ca2+ signals further trigger the calcium-regulated apoptosis in the cell. Furthermore, the stimulation can cause EGFR upregulation, which have been demonstrated to associate with diseases such as lung cancer, chronic obstructive pulmonary disease (COPD), and cardiovascular diseases. This study highlights the additional health risk considering that it can function as a contributing factor for other respiratory diseases.

  19. Determination of DPPH free radical scavenging activity

    African Journals Online (AJOL)

    Pavle

    2012-06-05

    Jun 5, 2012 ... 3Institute for Vegetable Crops, 26 000 Smederevska Palanka, Serbia. Accepted 18 May, 2012. The objective of this study was to evaluate antifungal and antioxidant activities of vegetable extracts. (Capsicum annuum L. cv. .... become dehydrated and prepared in triplicate, and then they were placed in an ...

  20. DETERMINANTS OF FISHER'S CHOICE OF FISHING ACTIVITY ...

    African Journals Online (AJOL)

    2017-10-02

    Oct 2, 2017 ... (boat), credit access, fishing experience, income and household size. The study revealed that lack of credit access as affirmed by majority (82%) of the respondents as the major challenge faced in the study .... four activities, then he is a full adopter and scores four and is assumed to be better off than all the ...

  1. Phytochemical Determinations and Antibacterial Activities of the ...

    African Journals Online (AJOL)

    The aqueous, ethanol and methanol extracts of the plants inhibited the growth of all the test organisms to varying degrees with the exception of E. coli, which was ... Synergistic effect of the ethanol and methanol extracts of the two plants resulted in enhanced antibacterial activity (large zones of inhibition, lower MIC, 0.31 ...

  2. Potential influence of interleukin-6 on the therapeutic effect of gefitinib in patients with advanced non-small cell lung cancer harbouring EGFR mutations.

    Science.gov (United States)

    Tamura, Tomoki; Kato, Yuka; Ohashi, Kadoaki; Ninomiya, Kiichiro; Makimoto, Go; Gotoda, Hiroko; Kubo, Toshio; Ichihara, Eiki; Tanaka, Takehiro; Ichimura, Koichi; Maeda, Yoshinobu; Hotta, Katsuyuki; Kiura, Katsuyuki

    2018-01-01

    Although epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) are a key therapy used for patients with EGFR-mutant non-small cell lung cancer (NSCLC), some of whom do not respond well to its therapy. Cytokine including IL-6 secreted by tumour cells is postulated as a potential mechanism for the primary resistance or low sensitivity to EGFR-TKIs. Fifty-two patients with advanced EGFR-mutant NSCLC who had received gefitinib were assessed retrospectively. The protein expression of IL-6 in the tumour cells was assessed by immunostaining and judged as positive if ≥ 50 of 100 tumour cells stained positively. Of the 52 patients, 24 (46%) and 28 (54%) were defined as IL-6-postitive (group P) and IL-6-negative (group N), respectively. Group P had worse progression-free survival (PFS) than that of group N, which was retained in the multivariate analysis (hazard ratio: 2.39; 95 %CI: 1.00-5.68; p < 0.05). By contrast, the PFS after platinum-based chemotherapy did not differ between groups P and N (p = 0.47). In cell line-based model, the impact of IL-6 on the effect of EGFR-TKIs was assessed. The combination of EGFR-TKI and anti-IL-6 antibody moderately improved the sensitivity of EGFR-TKI in lung cancer cell with EGFR mutation. Interestingly, suppression of EGFR with EGFR-TKI accelerated the activation of STAT3 induced by IL-6. Taken together, tumour IL-6 levels might indicate a subpopulation of EGFR-mutant NSCLC that benefits less from gefitinib monotherapy. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. Alterations in EGFR and related genes following neo-adjuvant chemotherapy in Chinese patients with non-small cell lung cancer.

    Directory of Open Access Journals (Sweden)

    Shuhang Wang

    Full Text Available Genetic aberrancies within epidermal growth factor receptor (EGFR pathway are associated with therapeutic outcomes of EGFR-tyrosine kinase inhibitors (TKIs in advanced non-small cell lung cancer (NSCLC. However, the impact of chemotherapy on EGFR-related genes alterations has not been defined in NSCLC. Our study aims to investigate the impact of neoadjuvant chemotherapy (Neoadj-Chemo on EGFR activating mutations and associated EGFR-TKIs resistance-related genes.Matched tumor samples were obtained retrospectively from 66 NSCLC patients (stages IIb-IIIb corresponding to pre- and post- Neoadj-Chemo. EGFR mutations were detected by denaturing high performance liquid chromatography (DHPLC and confirmed by Amplification Refractory Mutation System technology (ARMS, KRAS mutations, T790M mutation and c-MET amplification were identified using Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP, ARMS, and real-time PCR, respectively.Before Neoadj-Chemo, EGFR mutations were identified in 33.3% (22/66 of NSCLC patients. Only 18.2% (12/66 of patients carried EGFR mutations after Neoadj-Chemo (p = 0.013. The median peak value of EGFR 19 exon mutations decreased non-significantly after Neoadj-Chemo. KRAS mutation rate decreased from 4.6% (3/66 to 3.0% (2/66 with Neoadj-Chemo. Although the overall percentage of patients exhibiting c-MET amplifications (6.1% [4/66] did not change with Neoadj-Chemo, two patients transitioned from negative to positive c-MET amplification, and two patients reversed these changes post-Neoadj-Chemo. T790M mutations were absent from all samples.Neoadjuvant chemotherapy tends to decrease the mutation frequency of EGFR mutation and downstream genes, which suggests that real-time samples analysis for genetic aberrancies within EGFR pathways have important value to delineate specific patient populations and facilitate individualized treatment.

  4. Increased Epidermal Growth Factor Receptor (EGFR Associated with Hepatocyte Growth Factor (HGF and Symptom Severity in Children with Autism Spectrum Disorders (ASDs

    Directory of Open Access Journals (Sweden)

    Anthony J. Russo

    2014-01-01

    Full Text Available Background One in 88 children in the US is thought to have one of the autism spectrum disorders (ASDs. ASDs are characterized by social impairments and communication problems. Growth factors and their receptors may play a role in the etiology of ASDs. Research has shown that epidermal growth factor receptor (EGFR activation is associated with nerve cell development and repair. This study was designed to measure plasma levels of EGFR in autistic children and correlate these levels with its ligand, epidermal growth factor, other related putative biomarkers such as hepatocyte growth factor (HGF, the ligand for MET (MNNG HOS transforming gene receptor, as well as the symptom severity of 19 different behavioral symptoms. Subjects and Methods Plasma EGFR concentration was measured in 33 autistic children and 34 age- and gender-similar neurotypical controls, using an enzyme-linked immunosorbent assay. Plasma EGFR levels were compared to putative biomarkers known to be associated with EGFR and MET and severity levels of 19 autism-related symptoms. Results We found plasma EGFR levels significantly higher in autistic children, when compared to neurotypical controls. EGFR levels correlated with HGF and high-mobility group protein B1 (HMGB1 levels, but not other tested putative biomarkers, and EGFR levels correlated significantly with severity of expressive language, conversational language, focus/attention, hyperactivity, eye contact, and sound sensitivity deficiencies. Conclusions These results suggest a relationship between increased plasma EGFR levels and designated symptom severity in autistic children. A strong correlation between plasma EGFR and HGF and HMGB1 suggests that increased EGFR levels may be associated with the HGF/Met signaling pathway, as well as inflammation.

  5. Determination of silica activity in Bushveld rocks

    Science.gov (United States)

    Buchanan, D. L.; Nolan, J.; Viljoen, E. A.

    1980-08-01

    Values of silica activity have been calculated for Bushveld rocks from an extension of the mafic layered sequence north of the town of Bethal in the south-eastern Transvaal as well as the Roossenekal area in the eastern limb of the Complex. The samples examined contain the coexisting assemblage olivine, Ca-poor pyroxene, Ca-rich pyroxene and plagioclase. This enabled silica activities to be calculated from the following reactions: (Mg, Fe)2SiO4+SiO2⇆2(Mg, Fe)SiO3, CaAl2SiO6+SiO2⇆CaAl2Si2O8. Parallel curves of increasing silica activity with fractionation were established 0.20 log units apart. This represented a pressure of emplacement for the top of the layered zone in the Bethal area of 2.72±0.79 kbars. A value of 1.47±0.62 kbars was obtained for the Roossenekal area. These values are equivalent to 9.1±2.6 km and 4.9±2.1 km respectively, the latter figure being consistent with the minimum thickness of 4550 m of felsite and granophyre originally overlying the layered sequence and still preserved in the area west of Roossenekal.

  6. Enhanced efficacy of AZD3759 and radiation on brain metastasis from EGFR mutant non-small cell lung cancer.

    Science.gov (United States)

    Li, Xue; Wang, Yingchun; Wang, Jia; Zhang, Tianwei; Zheng, Li; Yang, Zhenfan; Xing, Ligang; Yu, Jinming

    2018-02-12

    The prognosis of patients with brain metastasis (BM) is poor. In this study, we demonstrated that AZD3759, an EGFR tyrosine kinase inhibitors (TKIs) with excellent blood-brain barrier (BBB) penetration, combined with radiation enhanced the antitumor efficacy in BM model from EGFR mutant (EGFRm) NSCLC. Besides, the antitumor activity displayed no difference between radiation concurrently with AZD3759 and radiation sequentially with AZD3759. Mechanistically, we found that two factors determined the enhanced efficacy: cells with EGFRm which were sensitive to AZD3759, and a relative high concentration of AZD3759. We have validated mechanisms underlying the radio-sensitizing effect of AZD3759, which were involved in decreased cell proliferation and survival, and suppressed repair of DNA damage. Moreover, our study found that AZD3759 inhibited both the non-homologous end joining (NHEJ) and homologous recombination (HR) DNA double stands breaks (DSBs) repair pathway, and abrogated the G2/M checkpoint to suppress DNA damage repair. We also detected the BBB penetration of AZD3759 when combined with cranial radiation. The results showed the BBB penetration of AZD3759 was decreased within 24 hours after radiation, however, the free concentration of AZD3759 in brain kept at a high level in the context of radiation. In conclusion, our findings suggest that AZD3759 combined with radiation enhances the antitumor activity in BM from EGFRm NSCLC, this combination therapy may be an effective treatment option for BM from EGFRm NSCLC. This article is protected by copyright. All rights reserved. © 2018 UICC.

  7. hMena+11a Isoform Serves as a Marker of Epithelial Phenotype and Sensitivity to EGFR Inhibition in Human Pancreatic Cancer Cell Lines

    Science.gov (United States)

    Pino, Maria S.; Balsamo, Michele; Di Modugno, Francesca; Mottolese, Marcella; Alessio, Massimo; Melucci, Elisa; Milella, Michele; McConkey, David J.; Philippar, Ulrike; Gertler, Frank B.; Natali, Pier Giorgio; Nistico, Paola

    2008-01-01

    Purpose hMena, member of the Ena/VASP protein family, is a cytoskeletal protein that is involved in the regulation of cell motility and adhesion. The aim of this study was to determine whether or not the expression of hMena isoforms correlated with sensitivity to EGFR tyrosine kinase inhibitors and could serve as markers with potential clinical use. Experimental design Human pancreatic ductal adenocarcinoma (PDAC) cell lines were characterized for in vitro sensitivity to erlotinib, expression of HER family receptors, markers of epithelial to mesenchymal transition (EMT), and expression of hMena and its isoform hMena+11a. The effects of EGF and erlotinib on hMena expression as well as the effect of hMena knock-down on cell proliferation were also evaluated. Results hMena was detected in all of the pancreatic tumor cell lines tested as well as in the majority of the human tumor samples [primary (92%) and metastatic (86%)]. Intriguingly, in vitro hMena+11a isoform was specifically associated with an epithelial phenotype, EGFR dependency and sensitivity to erlotinib. In epithelial BxPC3 cells EGF upregulated hMena/hMena+11a and erlotinib downregulated expression. hMena knock-down reduced cell proliferation and MAPK and AKT activation in BxPC3 cells and promoted the growth inhibitory effects of erlotinib. Conclusions Collectively, our data indicate that the hMena+11a isoform is associated with an epithelial phenotype and identifies EGFR dependent cell lines that are sensitive to the EGFR inhibitor erlotinib. The availability of anti-hMena+11a specific probes may offer a new tool in pancreatic cancer management if these results can be verified prospectively in cancer patients. PMID:18676769

  8. Impact of the 3D microenvironment on phenotype, gene expression, and EGFR inhibition of colorectal cancer cell lines.

    Directory of Open Access Journals (Sweden)

    Anna C Luca

    Full Text Available Three-dimensional (3D tumor cell cultures grown in laminin-rich-extracellular matrix (lrECM are considered to reflect human tumors more realistic as compared to cells grown as monolayer on plastic. Here, we systematically investigated the impact of ECM on phenotype, gene expression, EGFR signaling pathway, and on EGFR inhibition in commonly used colorectal cancer (CRC cell lines. LrECM on-top (3D culture assays were performed with the CRC cell lines SW-480, HT-29, DLD-1, LOVO, CACO-2, COLO-205 and COLO-206F. Morphology of lrECM cultivated CRC cell lines was determined by phase contrast and confocal laser scanning fluorescence microscopy. Proliferation of cells was examined by MTT assay, invasive capacity of the cell lines was assayed using Matrigel-coated Boyden chambers, and migratory activity was determined employing the Fence assay. Differential gene expression was analyzed at the transcriptional level by the Agilent array platform. EGFR was inhibited by using the specific small molecule inhibitor AG1478. A specific spheroid growth pattern was observed for all investigated CRC cell lines. DLD-1, HT-29 and SW-480 and CACO-2 exhibited a clear solid tumor cell formation, while LOVO, COLO-205 and COLO-206F were characterized by forming grape-like structures. Although the occurrence of a spheroid morphology did not correlate with an altered migratory, invasive, or proliferative capacity of CRC cell lines, gene expression was clearly altered in cells grown on lrECM as compared to 2D cultures. Interestingly, in KRAS wild-type cell lines, inhibition of EGFR was less effective in lrECM (3D cultures as compared to 2D cell cultures. Thus, comparing both 2D and 3D cell culture models, our data support the influence of the ECM on cancer growth. Compared to conventional 2D cell culture, the lrECM (3D cell culture model offers the opportunity to investigate permanent CRC cell lines under more physiological conditions, i.e. in the context of molecular

  9. Epidermal growth factor receptor (EGFR mutations and expression in squamous cell carcinoma of the esophagus in central Asia

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    Abedi-Ardekani Behnoush

    2012-12-01

    Full Text Available Abstract Background Esophageal squamous cell carcinoma (ESCC shows geographic variations in incidence, with high incidences (>50/105 person-years in central Asia, including North Eastern Iran (Golestan and Northern India (Kashmir. In contrast to Western countries, smoking does not appear to be a significant risk factor for ESCC in central Asia. In lung adenocarcinoma, activating mutations in the gene encoding epidermal growth factor receptor (EGFR are frequent in tumors of never smokers of Asian origin, predicting therapeutic sensitivity to Egfr-targeting drugs. Methods In this study 152 cases of histologically confirmed ESCC from Iran (Tehran and Golestan Province and North India (Kashmir Valley have been analyzed for EGFR mutation by direct sequencing of exons 18–21. Egfr protein expression was evaluated by immunohistochemistry in 34 samples from Tehran and HER2 mutations were analyzed in 54 cases from Kashmir. Results A total of 14 (9.2% EGFR variations were detected, including seven variations in exons. Among those, four (2.6% were already documented in lung cancers, two were reported as polymorphisms and one was a potentially new activating mutation. All but one variation in introns were previously identified as polymorphisms. Over-expression of Egfr was detected in 22/34 (65% of tested cases whereas no HER2 mutation was found in 54 cases from Kashmir. Conclusion Overall, EGFR mutations appear to be a rare event in ESCC in high incidence areas of central Asia, although a very small proportion of cases may harbor mutations predicting sensitivity to anti-Egfr drugs.

  10. Controlled physical activity for functional operability determination

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    Luchenkov А.А.

    2014-06-01

    Full Text Available The aim: to use veloergometry test at patients of high anaeshtesiology-operative risk before traumatic operations for functional operability determination. Material and methods: Randomized prospective research with the double "blind" control has been performed at 95 patients of high risk (ASA>III, undergoing long and traumatic operations on thoracic and abdominal organs. Patients have divided into groups without complications and with complications (51 and 44 patients which one day prior to operation have spent veloergometry test (VEMT. Average dynamic pressure (ADP, the general peripheral resistance of vessels (GPRV, a core index (Cl; arterio-venous (a-v difference on oxygen, oxygen delivery to tissues, consumption of oxygen and coefficients extraction oxygen in tissues; energy consumption have been investigated. Statistics has been done by nonparametric methods. Results. In response to veloergometry test in both groups growth of Cl at the expense of a tachycardia and GPRV fall which in complication group remains above norm is noted. In group without complications coefficients extraction oxygen in tissues were normalised, a-v difference on 02 became above norm, in other group — coefficients extraction oxygen in tissues and a-v difference on 02 began to exceed norm, and oxygen consumption has grown almost in 2 times. After VEMT a-v a difference on О and oxygen consumption were essentially above in group with complications. Under the influence of VEMT markecT stabilization of function of vegetative nervous systems (VNS. The number of complications made 39: intraoperation cardiovascular — 23, postoperative respiratory — 16. Clinically important connection (p=0,069 of perioperative complications with growth a-v differences on oxygen and a power interchanging have been received. Conclusion. Thus, the oxygen-energy exchange and the vegetative status can be referred to clinical functional operability determination.

  11. Can EGFR-Tyrosine Kinase Inhibitors (TKI) Alone Without Talc Pleurodesis Prevent Recurrence of Malignant Pleural Effusion (MPE) in Lung Adenocarcinoma.

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    Verma, Akash; Chopra, Akhil; Lee, Yeo W; Bharwani, Lavina D; Asmat, Atasha B; Aneez, Dokeu B A; Akbar, Fazuludeen A; Lim, Albert Y H; Chotirmall, Sanjay H; Abisheganaden, John

    2016-01-01

    Epidermal Growth Factor Receptor-Tyrosine Kinase Inhibitors (EGFR-TKIs) are effective against lung adenocarcinoma. However, limited data is available assessing the effectiveness of EGFR-TKI use in preventing re-accumulation of MPE. To our knowledge, there is no literature on comparison of talc pleurodesis with EGFR-TKIs alone on re-accumulation of MPE in Asian population. We investigated if EGFR-TKI therapy for advanced lung adenocarcinoma with malignant pleural effusion (MPE) is also successful in preventing pleural fluid re-accumulation following initial drainage. An observational cohort study of patients with lung adenocarcinoma and MPE in the year 2012 was conducted. 70 patients presented with MPE from lung adenocarcinoma. Fifty six underwent EGFR mutation testing of which 39 (69.6%) had activating EGFR mutation and 34 (87.1%) received TKI. 20 were managed by pleural fluid drainage only whereas 14 underwent talc pleurodesis following pleural fluid drainage. Time taken for the pleural effusion to re-accumulate in those with and without pleurodesis was 9.9 vs. 11.7 months, p=0.59 respectively. More patients (n=10, 25.6%) with activating EGFR mutation presented with complete opacification (white-out) of the hemithorax compared to none without activating EGFR mutation (p=0.02). In TKI eligible patients, early talc pleurodesis may not confer additional benefit in preventing re-accumulation of pleural effusion and may be reserved for non-adenocarcinoma histology, or EGFR negative adenocarcinoma. Complete opacification of the hemithorax on presentation may serve as an early radiographic signal of positive EGFR mutation status.

  12. 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

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

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    Yang Zhengyan

    2008-08-01

    Full Text Available Abstract Background 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. Methods 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+. Results 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. Conclusion 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.

  14. EGFR as a prognostic biomarker and therapeutic target in ovarian cancer: evaluation of patient cohort and literature review.

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    Mehner, Christine; Oberg, Ann L; Goergen, Krista M; Kalli, Kimberly R; Maurer, Matthew J; Nassar, Aziza; Goode, Ellen L; Keeney, Gary L; Jatoi, Aminah; Radisky, Derek C; Radisky, Evette S

    2017-05-01

    Limited effectiveness of therapeutic agents targeting epidermal growth factor receptor (EGFR) in clinical trials using unselected ovarian cancer patients has prompted efforts to more effectively stratify patients who might best benefit from these therapies. A series of studies that have evaluated immunohistochemical (IHC) staining of EGFR in ovarian cancer biopsies has produced unclear results as to the utility of this measure as a prognostic biomarker. Here, we used one of the largest, single institution cohorts to date to determine possible associations of EGFR expression with patient outcome. We performed IHC staining of EGFR in tissue microarrays including nearly 500 patient tumor samples. Staining was classified by subcellular localization (membranous, cytoplasmic) or by automated image analysis algorithms. We also performed a literature review to place these results in the context of previous studies. No significant associations were found between EGFR subcellular localization or expression and histology, stage, grade, or outcome. These results were broadly consistent with the consensus of the reviewed literature. These results suggest that IHC staining for EGFR may not be a useful prognostic biomarker for ovarian cancer patients. Future studies should pursue other staining methods or analysis in combination with other pathway mediators.

  15. 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

  16. 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.

  17. Clinical Observation of Icotinib Hydrochloride for Advanced Non-small Cell Lung Cancer Patients with EGFR Status Identified

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    Xi LI

    2015-12-01

    Full Text Available Background and objective Icotinib is the first self-developed small molecular drug in China for targeted therapy of lung cancer. Compared to the other two commercially available epidermal growth factor receptor (EGFR tyrosine kinase inhibitors, gefitinib and erlotinib, icotinib is similar to them in chemical structure, mechanism of activity and therapeutic effects. To explore the efficacy and side effects of icotinib hydrochloride in the treatment of the advanced non-small cell lung cancer (NSCLC patients with EGFR mutation and wild-type. Methods Patients with advanced NSCLC who were treated with icotinib hydrochloride in Beijing Chest Hospital were retrospective analyzed from March 2009 to December 2014. Results The clinical data of 124 patients (99 with EGFR mutation and 25 with wild type with advanced NSCLC were enrolled in this study. The patients’ overall objective response rate (ORR was 51.6 % and the disease control rate (DCR was 79.8%; The patients with EGFR mutation, ORR was 63.6%, DCR was 93.9%. The ORR was 4.0% and the DCR was 24.0% in the wild-type patients. Median progression-free survival (PFS with icotinib treatment in EGFR mutation patients was 10.5 months and 1.0 month in wild-type patients. The major adverse events were mild skin rash (30.6% and diarrhea (16.1%. Conclusion Monotherapy with icotinib hydrochloride is effective and tolerable for the advanced NSCLC EGFR mutation patients.

  18. Development of a Novel Human scFv Against EGFR L2 Domain by Phage Display Technology.

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    Rahbarnia, Leila; Farajnia, Safar; Babaei, Hossein; Majidi, Jafar; Veisi, Kamal; Khosroshahi, Shiva Ahdi; Tanomand, Asghar

    2017-01-01

    Epidermal growth factor receptor (EGFR) as a transmembrane tyrosine kinase receptor frequently overexpresses in tumors with epithelial origin. The L2 domain from extracellular part of EGFR is involved in ligand binding and the blockage of this domain prevents activation of related signaling pathways. This study was aimed to develop a novel human scFv against EGFR L2 domain as a promising target for cancer therapy. The L2 recombinant protein was purified and used for panning a human scFv phage library (Tomlinson I). In this study, a novel screening strategy was applied to select clones with high binding and enrichment of rare specific phage clones of the L2 protein. After five biopanning rounds several specific clones were isolated which among them one phage clone with high binding was purified for further analysis. The specific interaction of selected clone against target antigen was confirmed by ELISA and western blotting. Immunofluorescence staining showed that purified scFv binds to A431 cells surface, displaying EGFR surface receptor. In the present study, we isolated for the first time a novel human scFv against EGFR L2 domain. This study can be the groundwork for developing more effective diagnostic and therapeutic agents against EGFR overexpressing cancers using this novel human anti-L2 ScFv. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  19. Cellular Plasticity and Heterogeneity of EGFR Mutant Lung Cancer

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    2016-11-01

    AWARD NUMBER: W81XWH-14-1-0177 TITLE: Cellular Plasticity and Heterogeneity of EGFR Mutant Lung Cancer PRINCIPAL INVESTIGATOR: Katerina...5a. CONTRACT NUMBER Cellular Plasticity and Heterogeneity of EGFR Mutant Lung Cancer 5b. GRANT NUMBER W81XWH-14-1-0177 5c. PROGRAM ELEMENT NUMBER...epigenomic landscape of EGFR mutant SCLCs and their corresponding pre- treatment LUADs. These are very rare specimens. Through our Yale rebiopsy program

  20. Pedometer-determined physical activity and active transport in girls

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    Schofield Grant

    2008-01-01

    Full Text Available Abstract Background It is well established that the risk of insufficient physical activity is greater in girls than in boys, especially during the adolescent years. The promotion of active transport (AT to and from school has been posited as a practical and convenient solution for increasing girls' total daily activity. However, there is limited information describing the associations between AT choices and girls' physical activity across a range of age, ethnic, and socioeconomic groups. The objectives of this study were to (1 investigate physical activity patterns in a large multiethnic sample of female children and adolescents, and to (2 estimate the physical activity associated with AT to and from school. Methods A total of 1,513 girls aged 5–16 years wore sealed multiday memory (MDM pedometers for three weekdays and two weekend days. The ethnic composition of this sample was 637 European (42.1%, 272 Pacific Island (18.0%, 207 East Asian (13.7%, 179 Maori (11.8%, 142 South Asian (9.4%, and 76 from other ethnic groups (5%. Pedometer compliance and school-related AT were assessed by questionnaire. Results Mean weekday step counts (12,597 ± 3,630 were higher and less variable than mean weekend steps (9,528 ± 4,407. A consistent decline in daily step counts was observed with age: after adjustment for ethnicity and SES, girls in school years 9–10 achieved 2,469 (weekday and 4,011 (weekend fewer steps than girls in years 1–2. Daily step counts also varied by ethnicity, with Maori girls the most active and South Asian girls the least active. Overall, 44.9% of participants used AT for school-related travel. Girls who used AT to and from school averaged 1,052 more weekday steps than those who did not use AT. However, the increases in steps associated with AT were significant only in older girls (school years 5–10 and in those of Maori or European descent. Conclusion Our data suggest that adolescent-aged girls and girls of Asian descent are

  1. Cytotoxic Effect of Nano-SiO2 in Human Breast Cancer Cells via Modulation of EGFR Signaling Cascades.

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    Jeon, Donghwan; Kim, Hyungjoo; Nam, Keesoo; Oh, Sunhwa; Son, Seog-Ho; Shin, Incheol

    2017-11-01

    Silica nanoparticles (nano-SiO2) are widely used in many industrial areas and there is much controversy surrounding cytotoxic effects of such nanoparticles. In order to determine the toxicity and possible molecular mechanisms involved, we conducted several tests with two breast cancer cell lines, MDA-MB-231 and Hs578T. After exposure to nano-SiO2, growth, apoptosis, motility of breast cancer cells were monitored. In addition, modulation of signal transduction induced by nano-SiO2 was detected through western blot analysis. Treatment of nano-SiO2 repressed the growth of breast cancer cell lines. It also increased apoptosis and reduced cell motility. Moreover, exposure to nano-SiO2 significantly disturbed the dimerization of epidermal growth factor receptor (EGFR), followed by down-regulation of its downstream cellular sarcoma kinase (c-SRC) and signal transducer and activator of transcription 3 (STAT3) signaling cascades. Nano-SiO2 has a cytotoxic effect on MDA-MB-231 and Hs578T breast cancer cells via modulation of EGFR signaling cascades. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

  2. Osimertinib (AZD9291, a Mutant-Selective EGFR Inhibitor, Reverses ABCB1-Mediated Drug Resistance in Cancer Cells

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    Xiao-Yu Zhang

    2016-09-01

    Full Text Available In recent years, tyrosine kinase inhibitors (TKIs have been shown capable of inhibiting the ATP-binding cassette (ABC transporter-mediated multidrug resistance (MDR. In this study, we determine whether osimertinib, a novel selective, irreversible EGFR (epidermal growth factor receptor TKI, could reverse ABC transporter-mediated MDR. The results showed that, at non-toxic concentrations, osimertinib significantly sensitized both ABCB1-transfected and drug-selected cell lines to substrate anticancer drugs colchicine, paclitaxel, and vincristine. Osimertinib significantly increased the accumulation of [3H]-paclitaxel in ABCB1 overexpressing cells by blocking the efflux function of ABCB1 transporter. In contrast, no significant alteration in the expression levels and localization pattern of ABCB1 was observed when ABCB1 overexpressing cells were exposed to 0.3 µM osimertinib for 72 h. In addition, ATPase assay showed osimertinib stimulated ABCB1 ATPase activity. Molecular docking and molecular dynamic simulations showed osimertinib has strong and stable interactions at the transmembrane domain of human homology ABCB1. Taken together, our findings suggest that osimertinib, a clinically-approved third-generation EGFR TKI, can reverse ABCB1-mediated MDR, which supports the combination therapy with osimertinib and ABCB1 substrates may potentially be a novel therapeutic stategy in ABCB1-positive drug resistant cancers.

  3. EGFR-dependent TOR-independent endocycles support Drosophila gut epithelial regeneration.

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    Xiang, Jinyi; Bandura, Jennifer; Zhang, Peng; Jin, Yinhua; Reuter, Hanna; Edgar, Bruce A

    2017-05-09

    Following gut epithelial damage, epidermal growth factor receptor/mitogen-activated protein kinase (EGFR/MAPK) signalling triggers Drosophila intestinal stem cells to produce enteroblasts (EBs) and enterocytes (ECs) that regenerate the gut. As EBs differentiate into ECs, they become postmitotic, but undergo extensive growth and DNA endoreplication. Here we report that EGFR/RAS/MAPK signalling is required and sufficient to drive damage-induced EB/EC growth. Endoreplication occurs exclusively in EBs and newborn ECs that inherit EGFR and active MAPK from fast-dividing progenitors. Mature ECs lack EGF receptors and are refractory to growth signalling. Genetic tests indicated that stress-dependent EGFR/MAPK promotes gut regeneration via a novel mechanism that operates independently of Insulin/Pi3K/TOR signalling, which is nevertheless required in nonstressed conditions. The E2f1 transcription factor is required for and sufficient to drive EC endoreplication, and Ras/Raf signalling upregulates E2f1 levels posttranscriptionally. We illustrate how distinct signalling mechanisms direct stress-dependent versus homeostatic regeneration, and highlight the importance of postmitotic cell growth in gut epithelial repair.

  4. EGFR mutations cause a lethal syndrome of epithelial dysfunction with progeroid features.

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    Ganetzky, Rebecca; Finn, Erin; Bagchi, Atrish; Zollo, Ornella; Conlin, Laura; Deardorff, Matthew; Harr, Margaret; Simpson, Michael A; McGrath, John A; Zackai, Elaine; Lemmon, Mark A; Sondheimer, Neal

    2015-09-01

    The epidermal growth factor receptor (EGFR) is part of a large family of receptors required for communicating extracellular signals through internal tyrosine kinases. Epidermal growth factor (EGF) signaling is required for tissue development, whereas constitutive activation of this signaling pathway is associated with oncogenic transformation. We identified homozygous c.1283G>A (p.Gly428Asp) mutations in the extracellular domain of EGFR in two siblings. The children were born prematurely, had abnormalities in skin and hair, suffered multisystem organ failure, and died in the neonatal period from intestinal perforation. EGF failed to induce mutated receptor phosphorylation in patient-derived fibroblasts and activation of downstream targets was suppressed. The heterologously expressed extracellular domain was impaired in stability and the binding of EGF. Cells from the affected patient undergo early senescence with accelerated expression of β-galactosidase and shortened telomeres at all passages when compared to controls. A comparison of homozygous inherited regions from a separate report of a patient from the same ethnic background and EGFR genotype confirms the pathogenicity of EGFR mutations in congenital disease.

  5. The EGFR pathway regulates BCRP expression in NSCLC cells: role of erlotinib.

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    Porcelli, Letizia; Giovannetti, Elisa; Assaraf, Yehuda G; Jansen, Gerrit; Scheffer, George L; Kathman, Ietje; Azzariti, Amalia; Paradiso, Angelo; Peters, Godefridus J

    2014-01-01

    While multidrug resistance (MDR) in cancer is well established, little is known about the cellular pathways regulating the expression and trafficking of the MDR efflux transporter like BCRP (ABCG2). Here we evaluated the role of signalling downstream of EGFR on BCRP expression and sub-cellular localization using lung cancer cells harboring BCRP but expressing various EGFR and Ras activating mutations; A549 (K-Ras-G12S), H292 wild-type EGFR and Ras, and H1650 (EGFR-DelE747-A750). Immunocytochemistry and immunofluorescence studies demonstrated that BCRP was predominantly intracellular but its expression was found also on the plasma membrane in A549 and H1650 cells with activated Ras and EGFR. Remarkably, EGFR inhibition by erlotinib at IC₅₀ concentrations induced a differential timedependent alteration in BCRP gene and protein expression. In H1650 cells, erlotinib enhanced both the total and plasma membrane degradation of BCRP by ubiquitination within 6-24 hours, whereas BCRP expression regained the original basal levels after 48 hours. In erlotinib treated H292 cells, BCRP levels decreased at 24 hours until 72 hours, whereas in A549 cells erlotinib initially reduced BCRP expression but then induced its accumulation on the plasma membrane at 72 hours. We further found that the PI3K/Akt inhibitor LY294002 down-regulated BCRP expression, hence showing that the Akt pathway is involved in the regulation of BCRP expression but not in its localization in these lung cancer cell lines. Finally, the selective BCRP transport inhibitor Ko143 did not increase erlotinib sensitivity, but did decrease the transport activity of BCRP in A549 and H1650 cells as it induced the accumulation of its transport substrate topotecan. In conclusion, our results suggest that the EGFR and Akt pathways are involved in regulation of BCRP expression, trafficking and drug transport activity. These findings warrant future studies on the pharmacologic modulation of these pathways to enhance the

  6. Phase II study of erlotinib plus tivantinib (ARQ 197) in patients with locally advanced or metastatic EGFR mutation-positive non-small-cell lung cancer just after progression on EGFR-TKI, gefitinib or erlotinib.

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    Azuma, Koichi; Hirashima, Tomonori; Yamamoto, Nobuyuki; Okamoto, Isamu; Takahashi, Toshiaki; Nishio, Makoto; Hirata, Taizo; Kubota, Kaoru; Kasahara, Kazuo; Hida, Toyoaki; Yoshioka, Hiroshige; Nakanishi, Kaoru; Akinaga, Shiro; Nishio, Kazuto; Mitsudomi, Tetsuya; Nakagawa, Kazuhiko

    2016-01-01

    Patients with epidermal growth factor receptor (EGFR) activation mutation-positive non-small-cell lung cancer (NSCLC) respond well to EGFR tyrosine kinase inhibitors (EGFR-TKIs), but eventually become resistant in most cases. The hepatocyte growth factor/c-Met (HGF/c-Met) pathway is reported as a poor prognostic factor in various cancers. As c-Met is involved in EGFR-TKI resistance, a c-Met inhibitor and EGFR-TKI combination may reverse the resistance. This study evaluated the efficacy and safety of a c-Met selective inhibitor, tivantinib (ARQ 197), in combination with erlotinib, in Japanese EGFR mutation-positive patients with NSCLC who progressed while on EGFR-TKIs. This study enrolled 45 patients with NSCLC with acquired resistance to EGFR-TKIs, who were orally administered a daily combination of tivantinib/erlotinib. The primary end point was the overall response rate (ORR) and secondary end points included disease control rate, progression-free survival (PFS) and overall survival (OS). The patients underwent a mandatory second biopsy just after progression on EGFR-TKIs. The predictive biomarkers were extensively analysed using tumour and blood samples. The ORR was 6.7% (95% CI 1.4% to 18.3%), and the lower limit of 95% CI did not exceed the target of 5%. The median PFS (mPFS) and median OS (mOS) were 2.7 months (95% CI 1.4 to 4.2) and 18.0 months (95% CI 13.4 to 22.2), respectively. Both were longer in c-Met high patients (c-Met high vs low: mPFS 4.1 vs 1.4 months; mOS 20.7 vs 13.9 months). Partial response was observed in three patients, all of whom were c-Met and HGF high. The common adverse events and their frequencies were similar to those known to occur with tivantinib or erlotinib alone. Although this study did not prove clinical benefit of tivantinib in patients with acquired resistance to EGFR-TKIs, activated HGF/c-Met signalling, a poor prognostic factor, may define a patient subset associated with longer survival by the tivantinib

  7. EGFR(s) in aging and carcinogenesis of the gastrointestinal tract.

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    Nautiyal, Jyoti; Kanwar, Shailender Singh; Majumdar, Adhip P N

    2010-09-01

    Cells of the gastrointestinal (GI) mucosa are subject to a constant process of renewal which, in normal adults, reflects a balance between the rates of cell production and cell loss. Detailed knowledge of these events is, therefore, essential for a better understanding of the normal aging processes as well as many GI diseases, particularly malignancy, that represent disorders of tissue growth. In general, many GI dysfunctions, including malignancy, increase with advancing age, and aging itself is associated with alterations in structural and functional integrity of the GI tract. Although the regulatory mechanisms for age-related increase in the incidence of GI-cancers are yet to be fully delineated, recent evidence suggests a role for epidermal growth family receptors and its family members {referred to as EGFR(s)} in the development and progression of carcinogenesis during aging. The present communication discusses the involvement of EGFR(s) in regulating events of GI cancers during advancing age and summarizes the current available therapeutics targeting these receptors. The current review also describes the effectiveness of ErbB inhibitors as well as combination therapies. Additionally, the involvement of GI stem cells in the development of the age-related rise in GI cancers is emphasized.

  8. Focal Adhesion Kinase Inhibitors in Combination with Erlotinib Demonstrate Enhanced Anti-Tumor Activity in Non-Small Cell Lung Cancer.

    Directory of Open Access Journals (Sweden)

    Grant A Howe

    Full Text Available Blockade of epidermal growth factor receptor (EGFR activity has been a primary therapeutic target for non-small cell lung cancers (NSCLC. As patients with wild-type EGFR have demonstrated only modest benefit from EGFR tyrosine kinase inhibitors (TKIs, there is a need for additional therapeutic approaches in patients with wild-type EGFR. As a key component of downstream integrin signalling and known receptor cross-talk with EGFR, we hypothesized that targeting focal adhesion kinase (FAK activity, which has also been shown to correlate with aggressive stage in NSCLC, would lead to enhanced activity of EGFR TKIs. As such, EGFR TKI-resistant NSCLC cells (A549, H1299, H1975 were treated with the EGFR TKI erlotinib and FAK inhibitors (PF-573,228 or PF-562,271 both as single agents and in combination. We determined cell viability, apoptosis and 3-dimensional growth in vitro and assessed tumor growth in vivo. Treatment of EGFR TKI-resistant NSCLC cells with FAK inhibitor alone effectively inhibited cell viability in all cell lines tested; however, its use in combination with the EGFR TKI erlotinib was more effective at reducing cell viability than either treatment alone when tested in both 2- and 3-dimensional assays in vitro, with enhanced benefit seen in A549 cells. This increased efficacy may be due in part to the observed inhibition of Akt phosphorylation when the drugs were used in combination, where again A549 cells demonstrated the most inhibition following treatment with the drug combination. Combining erlotinib with FAK inhibitor was also potent in vivo as evidenced by reduced tumor growth in the A549 mouse xenograft model. We further ascertained that the enhanced sensitivity was irrespective of the LKB1 mutational status. In summary, we demonstrate the effectiveness of combining erlotinib and FAK inhibitors for use in known EGFR wild-type, EGFR TKI resistant cells, with the potential that a subset of cell types, which includes A549, could be

  9. Effect of phosphorylation on EGFR dimer stability probed by single-molecule dynamics and FRET/FLIM.

    Science.gov (United States)

    Coban, Oana; Zanetti-Dominguez, Laura C; Matthews, Daniel R; Rolfe, Daniel J; Weitsman, Gregory; Barber, Paul R; Barbeau, Jody; Devauges, Viviane; Kampmeier, Florian; Winn, Martyn; Vojnovic, Borivoj; Parker, Peter J; Lidke, Keith A; Lidke, Diane S; Ameer-Beg, Simon M; Martin-Fernandez, Marisa L; Ng, Tony

    2015-03-10

    Deregulation of epidermal growth factor receptor (EGFR) signaling has been correlated with the development of a variety of human carcinomas. EGF-induced receptor dimerization and consequent trans- auto-phosphorylation are among the earliest events in signal transduction. Binding of EGF is thought to induce a conformational change that consequently unfolds an ectodomain loop required for dimerization indirectly. It may also induce important allosteric changes in the cytoplasmic domain. Despite extensive knowledge on the physiological activation of EGFR, the effect of targeted therapies on receptor conformation is not known and this particular aspect of receptor function, which can potentially be influenced by drug treatment, may in part explain the heterogeneous clinical response among cancer patients. Here, we used Förster resonance energy transfer/fluorescence lifetime imaging microscopy (FRET/FLIM) combined with two-color single-molecule tracking to study the effect of ATP-competitive small molecule tyrosine kinase inhibitors (TKIs) and phosphatase-based manipulation of EGFR phosphorylation on live cells. The distribution of dimer on-times was fitted to a monoexponential to extract dimer off-rates (koff). Our data show that pretreatment with gefitinib (active conformation binder) stabilizes the EGFR ligand-bound homodimer. Overexpression of EGFR-specific DEP-1 phosphatase was also found to have a stabilizing effect on the homodimer. No significant difference in the koff of the dimer could be detected when an anti-EGFR antibody (425 Snap single-chain variable fragment) that allows for dimerization of ligand-bound receptors, but not phosphorylation, was used. These results suggest that both the conformation of the extracellular domain and phosphorylation status of the receptor are involved in modulating the stability of the dimer. The relative fractions of these two EGFR subpopulations (interacting versus free) were obtained by a fractional-intensity analysis of

  10. EMT-induced stemness and tumorigenicity are fueled by the EGFR/Ras pathway.

    Directory of Open Access Journals (Sweden)

    Dominic Chih-Cheng Voon

    Full Text Available Recent studies have revealed that differentiated epithelial cells would acquire stem cell-like and tumorigenic properties following an Epithelial-Mesenchymal Transition (EMT. However, the signaling pathways that participate in this novel mechanism of tumorigenesis have not been fully characterized. In Runx3 (-/- p53 (-/- murine gastric epithelial (GIF-14 cells, EMT-induced plasticity is reflected in the expression of the embryonal proto-oncogene Hmga2 and Lgr5, an exclusive gastrointestinal stem cell marker. Here, we report the concurrent activation of an EGFR/Ras gene expression signature during TGF-β1-induced EMT in GIF-14 cells. Amongst the altered genes was the induction of Egfr, which corresponded with a delayed sensitization to EGF treatment in GIF-14. Co-treatment with TGF-β1 and EGF or the expression of exogenous KRas led to increased Hmga2 or Lgr5 expression, sphere initiation and colony formation in soft agar assay. Interestingly, the gain in cellular plasticity/tumorigenicity was not accompanied by increased EMT. This uncoupling of EMT and the induction of plasticity reveals an involvement of distinct signaling cues, whereby the EGFR/Ras pathway specifically promotes stemness and tumorigenicity in EMT-altered GIF-14 cells. These data show that the EGFR/Ras pathway requisite for the sustenance of gastric stem cells in vivo and in vitro is involved in the genesis and promotion of EMT-induced tumor-initiating cells.

  11. Growth Factor Identity Is Encoded by Discrete Coiled-Coil Rotamers in the EGFR Juxtamembrane Region.

    Science.gov (United States)

    Doerner, Amy; Scheck, Rebecca; Schepartz, Alanna

    2015-06-18

    Binding of transforming growth factor α (TGF-α) to the epidermal growth factor receptor (EGFR) extracellular domain is encoded through the formation of a unique antiparallel coiled coil within the juxtamembrane segment. This new coiled coil is an "inside-out" version of the coiled coil formed in the presence of epidermal growth factor (EGF). A third, intermediary coiled-coil interface is formed in the juxtamembrane region when EGFR is stimulated with betacellulin. The seven growth factors that activate EGFR in mammalian systems (EGF, TGF-α, epigen, epiregulin, betacellulin, heparin-binding EGF, and amphiregulin) fall into distinct categories in which the structure of the coiled coil induced within the juxtamembrane region correlates with cell state. The observation that coiled-coil state tracks with the downstream signaling profiles for each ligand provides evidence for growth factor functional selectivity by EGFR. Encoding growth factor identity in alternative coiled-coil rotamers provides a simple and elegant method for communicating chemical information across the plasma membrane. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Phosphorylation of Both EGFR and ErbB2 Is a Reliable Predictor of Prostate Cancer Cell Proliferation in Response to EGF

    Directory of Open Access Journals (Sweden)

    Soha Salama El Sheikh

    2004-11-01

    Full Text Available Despite multiple reports of overexpression in prostate cancer (PC, the reliance of PC cells on activated epidermal growth factor receptor (EGFR and its downstream signaling to phosphoinositide 3'-kinase/Akt (PI3K/Akt/PTEN and/or mitogen-activated protein kinase (MAPK/ERK pathways has not been fully elucidated. In this study, we compared the role of EGF-mediated signaling in nonmalignant (BPH-1, PNT1A, and PNT1 B and PC cell lines (DU145, PC3, LNCaP, and CWR22Rv1. EGF-induced proliferation was observed in all EGFR-expressing PC cells except PC3, indicating that EGFR expression does not unequivocally trigger proliferation following EGF stimulation. ErbB2 recruitment potentiated EGF-induced signals and was associated with the most pronounced effects of EGF despite low EGFR expression. In this way, the sum of EGFR and ErbB2 receptor phosphorylation proved to be a more sensitive indicator of EGF-induced proliferation than quantification of the expression of either receptor alone. Both Akt and ERK were rapidly phosphorylated in response to EGF, with ERK phosphorylation being weakest in PC3 cells. Extrapolation of these findings to clinical PC suggests that assessment of phosphorylated EGFR + ErbB2 together could serve as a marker for sensitivity to anti-EGFR-targeted therapies.

  13. Decreased EGFR mRNA expression in response to antipsoriatic ...

    African Journals Online (AJOL)

    Dithranol is enormously effective in the treatment of psoriasis; however its molecular mode of action should be further elucidated. Since epidermal growth factor receptor (EGFR) is involved in the pathogenesis of psoriasis, the objective of this study was to investigate the transcriptional effect of dithranol on EGFR gene ...

  14. Graf regulates hematopoiesis through GEEC endocytosis of EGFR.

    Science.gov (United States)

    Kim, Sungdae; Nahm, Minyeop; Kim, Najin; Kwon, Yumi; Kim, Joohyung; Choi, Sukwoo; Choi, Eun Young; Shim, Jiwon; Lee, Cheolju; Lee, Seungbok

    2017-11-15

    GTPase regulator associated with focal adhesion kinase 1 (GRAF1) is an essential component of the GPI-enriched endocytic compartment (GEEC) endocytosis pathway. Mutations in the human GRAF1 gene are associated with acute myeloid leukemia, but its normal role in myeloid cell development remains unclear. We show that Graf, the Drosophila ortholog of GRAF1, is expressed and specifically localizes to GEEC endocytic membranes in macrophage-like plasmatocytes. We also find that loss of Graf impairs GEEC endocytosis, enhances EGFR signaling and induces a plasmatocyte overproliferation phenotype that requires the EGFR signaling cascade. Mechanistically, Graf-dependent GEEC endocytosis serves as a major route for EGFR internalization at high, but not low, doses of the predominant Drosophila EGFR ligand Spitz (Spi), and is indispensable for efficient EGFR degradation and signal attenuation. Finally, Graf interacts directly with EGFR in a receptor ubiquitylation-dependent manner, suggesting a mechanism by which Graf promotes GEEC endocytosis of EGFR at high Spi. Based on our findings, we propose a model in which Graf functions to downregulate EGFR signaling by facilitating Spi-induced receptor internalization through GEEC endocytosis, thereby restraining plasmatocyte proliferation. © 2017. Published by The Company of Biologists Ltd.

  15. Detecting and treating breast cancer resistance to EGFR inhibitors

    Energy Technology Data Exchange (ETDEWEB)

    Moonlee, Sun-Young; Bissell, Mina J.; Furuta, Saori; Meier, Roland; Kenny, Paraic A.

    2016-04-05

    The application describes therapeutic compositions and methods for treating cancer. For example, therapeutic compositions and methods related to inhibition of FAM83A (family with sequence similarity 83) are provided. The application also describes methods for diagnosing cancer resistance to EGFR inhibitors. For example, a method of diagnosing cancer resistance to EGFR inhibitors by detecting increased FAM83A levels is described.

  16. RRx-001-Induced Tumor Necrosis and Immune Cell Infiltration in an EGFR Mutation-Positive NSCLC with Resistance to EGFR Tyrosine Kinase Inhibitors: A Case Report

    Directory of Open Access Journals (Sweden)

    Christina Brzezniak

    2016-01-01

    Full Text Available We present the case of a 49-year-old male with metastatic epidermal growth factor receptor (EGFR mutation-positive adenocarcinoma of the lung that continues to outlive stage IV diagnosis of non-small cell lung cancer after treatment with RRx-001, an experimental anticancer agent with epigenetic and immunologic activity, in the context of a phase II clinical trial called TRIPLE THREAT. Currently, no adequate treatment options exist for patients with EGFR mutation-positive tumors who have failed a 1st-generation tyrosine kinase inhibitor (erlotinib or gefitinib treatment and do not develop a resistant mutation. Biopsy of a large pancreatic metastasis after RRx-001 demonstrated extensive necrosis with CD3+ and CD8+ immune cell infiltration that appears to correlate with prolonged survival despite end-stage disease. These results suggest that the mode of action of RRx-001 is related to immune stimulation in addition to epigenetic inhibition.

  17. Anti-EGFR Agents: Current Status, Forecasts and Future Directions.

    Science.gov (United States)

    Kwapiszewski, Radoslaw; Pawlak, Sebastian D; Adamkiewicz, Karolina

    2016-12-01

    The epidermal growth factor receptor (EGFR) is one of the most important and attractive targets for specific anticancer therapies. It is a robust regulator of pathways involved in cancer pathogenesis and progression. Thus far, clinical trials have demonstrated the benefits of monoclonal antibodies and synthetic tyrosine kinase inhibitors in targeting this receptor; however, novel strategies are still being developed. This article reviews the current state of efforts in targeting the EGFR in cancer therapy. Following a brief characterization of EGFR, we will present a complete list of anti-EGFR agents that are already approved, and available in clinical practice. Aside from the indications, we will present the sales forecasts and expiry dates of product patents for the selected agents. Finally, we discuss the novel anti-EGFR strategies that are currently in preclinical development.

  18. Comparison of EGFR and KRAS Status between Primary Non-small Cell Lung Cancer and Corresponding Metastases: A Systematic Review and meta-analysis

    Directory of Open Access Journals (Sweden)

    Chengbo HAN

    2010-09-01

    Full Text Available Background and objective Epidermal growth factor receptor (EGFR and KRAS status were particularly critical for the choice of first-line targeted therapy of non-small cell lung cancer (NSCLC, while the primary tumor and metastases might be different in the EGFR and KRAS gene status. The aim of this pooled analysis is to compare EGFR and KRAS status in matching primary NSCLC and metastases and further to guide clinical practice. Methods Systematic computerized searches of the Pubmed and Medline databases (up to May 10, 2010 meeting specified search criteria were performed, followed by a further screening according to inclusive and exclusive criteria. Results Fourteen articles were selected into the final meta-analysis with paired primary and metastatic cases of 598. Expression level of EGFR protein and mutation frequency of KRAS gene in primary tumors were higher than that in metastases, relative risk (RR=1.13 (95%CI: 0.98-1.31, P=0.09 and RR=1.39 (95%CI: 0.95-2.03, P=0.09, respectively. EGFR gene copy number in metastases was higher than that in primary tumor, RR=0.74 (95%CI: 0.53-1.02, P=0.06. There was no statistically significant difference of EGFR mutation frequency in primary tumors and metastases (P=0.31. The discordant rate in primary and metastases was 17.09% for EGFR mutation, 27.07% for EGFR amplification, 27.84% for EGFR protein expression and 25.91% for KRAS mutation. Conclusion The systematic analysis showed that the EGFR mutation status in primary lung cancer and corresponding metastases was more stable than KRAS gene. KRAS mutation in primary lung cancerous foci seems to better reflect systemically cancerous genetic characteristics of KRAS gene. Determination of KRAS gene status based merely on metastatic foci might lead to more resistant selections of EGFR tyrosine kinase inhibitor (TKI therapy. Combined detection of EGFR and KRAS mutation from primary NSCLC foci might serve as a better predictive biomarker for anti-EGFR targeted

  19. Cholinergic Transactivation of the EGFR in HaCaT Keratinocytes Stimulates a Flotillin-1 Dependent MAPK-Mediated Transcriptional Response

    Directory of Open Access Journals (Sweden)

    Sina Kühne

    2015-03-01

    Full Text Available Acetylcholine and its receptors regulate numerous cellular processes in keratinocytes and other non-neuronal cells. Muscarinic acetylcholine receptors are capable of transactivating the epidermal growth factor receptor (EGFR and, downstream thereof, the mitogen-activated protein kinase (MAPK cascade, which in turn regulates transcription of genes involved in cell proliferation and migration. We here show that cholinergic stimulation of human HaCaT keratinocytes results in increased transcription of matrix metalloproteinase MMP-3 as well as several ligands of the epidermal growth factor family. Since both metalloproteinases and the said ligands are involved in the transactivation of the EGFR, this transcriptional upregulation may provide a positive feed-forward loop for EGFR/MAPK activation. We here also show that the cholinergic EGFR and MAPK activation and the upregulation of MMP-3 and EGF-like ligands are dependent on the expression of flotillin-1 which we have previously shown to be a regulator of MAPK signaling.

  20. Insufficiency of peripheral blood as a substitute tissue for detecting EGFR mutations in lung cancer: a meta-analysis.

    Science.gov (United States)

    Li, Zhijun; Zhang, Yongjun; Bao, Wenlong; Jiang, Chuming

    2014-12-01

    The detection of epidermal growth factor receptor (EGFR) mutations in non-small cell lung cancer tissues is necessary for effective treatment with EGFR tyrosine kinase inhibitors. However, tumor tissues may not be available in all situations. Studies have evaluated the potential use of serum or plasma for detecting the EGFR mutation status, but the results have been inconclusive. Here, a meta-analysis was performed to determine whether blood samples could serve as substitutes for tissue specimens in detecting the EGFR mutation status. Databases, including PubMed and Embase, were searched for relevant studies published from 2005 to 2013 that included true-positive, false-positive, true-negative, and false-negative values of the EGFR mutation status of the blood compared with tissue specimens. Summary receiver operating characteristic curves were developed to explore the threshold effect. Spearman's correlation coefficient was calculated to analyze the heterogeneity between studies. Pooled sensitivity and specificity were evaluated using Meta-DiSc version 1.4. Thirteen articles involving 1,591 cases were enrolled, with a pooled sensitivity and specificity of 64.5 % (95 % CI = 0.605-0.683) and 88.5 % (95 % CI = 0.863-0.904), respectively. Heterogeneity among the studies was caused by factors other than threshold effect. The findings were influenced by test method (p = 0.0354). Blood samples had a high specificity and relatively low sensitivity for detecting EGFR mutations compared to tumor tissues. The results of this meta-analysis suggest that peripheral blood is insufficient as a substitute for tumor tissues in detecting EGFR mutations in clinical practice.

  1. [Value of immunohistochemical staining with mutation-specific antibodies in detecting EGFR mutations: a meta-analysis].

    Science.gov (United States)

    Ma, Qing; Wang, Jing; Zhong, Diansheng; Ning, Chao; Liu, Chang; Xiao, Ping

    2014-06-20

    It has been proven that epidermal growth factor receptor (EGFR) mutation is the most important predictive factor for determining the effect of EGFR tyrosine kinase inhibitors (TKIs) applied to non-small cell lung cancer (NSCLC) patients. The patients with EGFR mutations response better to TKIs. To detect EGFR mutation has been particularly essential to select first-line treatment for lung cancer patients. To research and analyze the sensitivity and specificity of immunohistochemistry (IHC) using mutation specific antibodies in detecting EGFR mutations compared with DNA sequencing, and further evaluate the accuracy and clinical application value of IHC. All required articles in Pubmed database were searched. The deadline of retrieval was March 26, 2013. Then further screening the articles based on the inclusion and exclusion criteria. Meta analysis of diagnostic test was applied to analyze the sensitivity and specificity of IHC compared with DNA sequencing for the detection of EGFR mutations. Ten articles were included in the meta analysis, there were 1,679 samples in L858R group and 1,041 samples in E746-A750del group. The DOR were 225.17 (95%CI: 55.67-910.69) and 267.16 (95%CI: 132.45-538.88) respectively; the AUC of SROC were 0.948,4 (SEAUC=0.014,4) and 0.981,3 (SEAUC=0.009,9) respectively; the Q values were 0.888,3 (SEQ*=0.019,2) and 0.939,7 (SEQ*=0.019,1) respectively. The specificity and sensitivity of IHC method using these two mutation-specific antibodies were relatively high. As a screening method for EGFR mutations, the IHC with mutation specific antibodies is of clinical value.

  2. The expression of epidermal growth factor (EGF) and its receptor (EGFR) during post-natal testes development in the yak.

    Science.gov (United States)

    Pan, Y; Cui, Y; Yu, S; Zhang, Q; Fan, J; Abdul Rasheed, B; Yang, K

    2014-12-01

    Growth factors play critical role in cell proliferation, regulate tissue differentiation and modulate organogenesis. Several growth factors have been identified in the testes of various mammalian species in last few years. In present investigation, the objective was to determine the expression of epidermal growth factor (EGF) and the epidermal growth factor receptor (EGFR) in yak testicular tissue by relative quantitative real time polymerase chain reaction (RT-PCR), Western blot (WB) and immunohistochemistry (IHC) from mRNA and protein levels. The testicular tissues were collected from male yak at 6 and 24 months old. Results of RT-PCR and WB showed that the expression quantity of EGF and EGFR at 24 months of age was higher than at 6 months, and the increase rate of EGFR on mRNA and protein levels was higher than the increase rate EGF during post-natal testes development. Positive staining for EGF and EGFR was very low and mainly localized to Leydig cells testes at 6 months of age with immunohistochemistry, and seminiferous tubules were not observed. At 24 month of age, both the EGF and EGFR could be detected in Leydig cells, peritubular myoid cells, sertoli cells and germ cells of the yak testes. However, EGF and EGFR were localized to preferential adluminal compartment and basal compartment in the seminiferous tubules, respectively. In conclusion, the findings in present studies suggest that EGF and EGFR as important paracrine and/or autocrine regulators in yak testes development and spermatogenesis. © 2014 Blackwell Verlag GmbH.

  3. Comparison of cross-platform technologies for EGFR T790M testing in patients with non-small cell lung cancer.

    Science.gov (United States)

    Li, Xuefei; Zhou, Caicun

    2017-11-21

    Somatic mutations in the gene encoding epidermal growth factor receptor (EGFR) play an important role in determining targeted treatment modalities in non-small cell lung cancer (NSCLC). The EGFR T790M mutation emerges in approximately 50% of cases who acquire resistance to tyrosine kinase inhibitors. Detecting EGFR T790M mutation in tumor tissue is challenging due to heterogeneity of the tumor, low abundance of the mutation and difficulty for re-biopsy in patients with advanced disease. Alternatively, circulating tumor DNA (ctDNA) has been proposed as a non-invasive method for mutational analysis. The presence of EGFR mutations in ctDNA predicts response to the EGFR TKIs in the first-line setting. Molecular testing is now considered a standard care for NSCLC. The advent of standard commercially available kits and targeted mutational analysis has revolutionized the accuracy of mutation detection platforms for detection of EGFR mutations. Our review provides an overview of various commonly used platforms for detecting EGFR T790M mutation in tumor tissue and plasma.

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

    Science.gov (United States)

    Shi, Tujin; Niepel, Mario; McDermott, Jason E.; Gao, Yuqian; Nicora, Carrie D.; Chrisler, William B.; Markillie, Lye M.; Petyuk, Vladislav A.; Smith, Richard D.; Rodland, Karin D.; Sorger, Peter K.; Qian, Wei-Jun; Wiley, H. Steven

    2016-01-01

    Various genetic mutations associated with cancer are known to alter cell signaling, but it is not clear whether they dysregulate signaling pathways by altering the abundance of pathway proteins. Using a combination of RNA sequencing and ultrasensitive targeted proteomics, we defined the primary components—16 core proteins and 10 feedback regulators—of the epidermal growth factor receptor (EGFR)–mitogen-activated protein kinase (MAPK) pathway in normal human mammary epithelial cells and then quantified their absolute abundance across a panel of normal and breast cancer cell lines as well as fibroblasts. We found that core pathway proteins were present at very similar concentrations across all cell types, with a variance similar to that of proteins previously shown to display conserved abundances across species. In contrast, EGFR and transcriptionally controlled feedback regulators were present at highly variable concentrations. The absolute abundance of most core proteins was between 50,000 and 70,000 copies per cell, but the adaptors SOS1, SOS2, and GAB1 were found at far lower amounts (2000 to 5000 copies per cell). MAPK signaling showed saturation in all cells between 3000 and 10,000 occupied EGFRs, consistent with the idea that adaptors limit signaling. Our results suggest that the relative stoichiometry of core MAPK pathway proteins is very similar across different cell types, with cell-specific differences mostly restricted to variable amounts of feedback regulators and receptors. The low abundance of adaptors relative to EGFR could be responsible for previous observations that only a fraction of total cell surface EGFR is capable of rapid endocytosis, high-affinity binding, and mitogenic signaling. PMID:27405981

  5. EGFR Monoclonal Antibodies in the Treatment of Squamous Cell Carcinoma of the Head and Neck: A View beyond Cetuximab

    Directory of Open Access Journals (Sweden)

    Scott A. Kono

    2012-01-01

    Full Text Available Squamous cell carcinoma of the head and neck (SCCHN is a prevalent disease both in the United States and worldwide with an overall poor prognosis, in part due to limited activity of existing therapy. Primary therapy is largely dictated by the anatomical origin of the cancer and whether distant disease is present. Many patients with localized disease are treated with chemoradiotherapy, either in the definitive or adjuvant setting, and those with metastatic disease are treated with palliative chemotherapy. The chemotherapy used in SCCHN can be toxic, whether given with radiation or alone. The epidermal growth factor receptor (EGFR is highly expressed in SCCHN and serves as a logical therapeutic target. EGFR-directed monoclonal antibodies (MoAbs have higher activity in SCCHN than small molecule tyrosine kinase inhibitors. Cetuximab, a widely studied EGFR MoAb, is FDA approved in the metastatic setting, as well as with radiation for locally advanced disease. Despite improvements in survival when cetuximab is incorporated with chemotherapy for metastatic disease, the prognosis of patients remains poor. Novel EGFR MoAbs are being developed with the goal of improving efficacy and tolerability. This paper will summarize the use of EGFR-directed MoAbs in treating SCCHN with a focus on novel agents being tested.

  6. Systems biology modeling reveals a possible mechanism of the tumor cell death upon oncogene inactivation in EGFR addicted cancers.

    Directory of Open Access Journals (Sweden)

    Jian-Ping Zhou

    Full Text Available Despite many evidences supporting the concept of "oncogene addiction" and many hypotheses rationalizing it, there is still a lack of detailed understanding to the precise molecular mechanism underlying oncogene addiction. In this account, we developed a mathematic model of epidermal growth factor receptor (EGFR associated signaling network, which involves EGFR-driving proliferation/pro-survival signaling pathways Ras/extracellular-signal-regulated kinase (ERK and phosphoinositol-3 kinase (PI3K/AKT, and pro-apoptotic signaling pathway apoptosis signal-regulating kinase 1 (ASK1/p38. In the setting of sustained EGFR activation, the simulation results show a persistent high level of proliferation/pro-survival effectors phospho-ERK and phospho-AKT, and a basal level of pro-apoptotic effector phospho-p38. The potential of p38 activation (apoptotic potential due to the elevated level of reactive oxygen species (ROS is largely suppressed by the negative crosstalk between PI3K/AKT and ASK1/p38 pathways. Upon acute EGFR inactivation, the survival signals decay rapidly, followed by a fast increase of the apoptotic signal due to the release of apoptotic potential. Overall, our systems biology modeling together with experimental validations reveals that inhibition of survival signals and concomitant release of apoptotic potential jointly contribute to the tumor cell death following the inhibition of addicted oncogene in EGFR addicted cancers.

  7. Determination of amylase activity of crude extract from partially ...

    African Journals Online (AJOL)

    Amylase activity of crude extract from partially germinated mango seeds ( Mangifera oraphila) was determined using Caraway-Somogyi iodine/potassium iodide (IKI) method. The effects of varied pH and temperature were also investigated. The amylase was extracted with 0.1 M acetate buffer (pH 4.2). Amylase activity of the ...

  8. Determination of antioxidant activity in methanolic and chloroformic ...

    African Journals Online (AJOL)

    Administrator

    2011-06-06

    Jun 6, 2011 ... The aim of this study was to determine and compare the antioxidant activity of methanolic and chloroformic extracts of Momordica charantia (MC) fruit. In this study, the total antioxidant and free radical scavenging activities in methanolic and chloroformic were measured by ferric thiocyanate. (FTC) ...

  9. Using mobile phone data records to determine criminal activity space

    CSIR Research Space (South Africa)

    Schmitz, Peter MU

    2007-09-01

    Full Text Available to anchor points than property crimes. Using call data records (CDR) or active tracking data makes it possible to determine the activity space of an individual using cellular data. The data alone is not sufficient and needs to be supported by local knowledge...

  10. Determination of activities of human carbonic anhydrase II inhibitors ...

    African Journals Online (AJOL)

    Purpose: To evaluate the activities of new curcumin analogs as carbonic anhydrase II (CA-II) inhibitor. Methods: Carbonic anhydrase II (CA-II) inhibition was determined by each ligand capability to inhibit the esterase activity of CA-II using 4-NPA as a substrate in 96-well plates. Dimethyl sulfoxide was used to dissolve each ...

  11. EGFR(S) inhibitors in the treatment of gastro-intestinal cancers: what's new?

    Science.gov (United States)

    Kanwar, Shailender Singh; Nautiyal, Jyoti; Majumdar, Adhip P N

    2010-06-01

    In the past 10 to 15 years, a considerable progress has been made in the treatment of gastrointestinal (GI) related malignancies, as number of agents expanded from only one in 1995 to seven in 2006. Current review describes the recent role of targeted therapies, specifically EGFR inhibitors in the treatment of GI cancers. Importance of dietary agents in the treatment and prevention of GI cancers is also reviewed.

  12. High specificity but low sensitivity of mutation-specific antibodies against EGFR mutations in non-small-cell lung cancer.

    Science.gov (United States)

    Bondgaard, Anna-Louise; Høgdall, Estrid; Mellemgaard, Anders; Skov, Birgit G

    2014-12-01

    Determination of epidermal growth factor receptor (EGFR) mutations has a pivotal impact on treatment of non-small-cell lung cancer (NSCLC). A standardized test has not yet been approved. So far, Sanger DNA sequencing has been widely used. Its rather low sensitivity has led to the development of more sensitive methods including real-time PCR (RT-PCR). Immunohistochemistry with mutation-specific antibodies might be a promising detection method. We evaluated 210 samples with NSCLC from an unselected Caucasian population. Extracted DNA was analyzed for EGFR mutations by RT-PCR (Therascreen EGFR PCR kit, Qiagen, UK; reference method). For immunohistochemistry, antibodies against exon19 deletions (clone 6B6), exon21 mutations (clone 43B2) from Cell Signaling Technology (Boston, USA) and EGFR variantIII (clone 218C9) from Dako (Copenhagen, DK) were applied. Protein expression was evaluated, and staining score (multipum of intensity (graded 0-3) and percentages (0-100%) of stained tumor cells) was calculated. Positivity was defined as staining score >0. Specificity of exon19 antibody was 98.8% (95% confidence interval=95.9-99.9%) and of exon21 antibody 97.8% (95% confidence interval=94.4-99.4%). Sensitivity of exon19 antibody was 63.2% (95% confidence interval=38.4-83.7%) and of exon21 antibody was 80.0% (95% confidence interval=44.4-97.5%). Seven exon19 and four exon21 mutations were false negatives (immunohistochemistry negative, RT-PCR positive). Two exon19 and three exon21 mutations were false positive (immunohistochemistry positive, RT-PCR negative). One false positive exon21 mutation had staining score 300. The EGFR variantIII antibody showed no correlation to EGFR mutation status determined by RT-PCR or to EGFR immunohistochemistry. High specificity of the mutation-specific antibodies was demonstrated. However, sensitivity was low, especially for exon19 deletions, and thus these antibodies cannot yet be used as screening method for EGFR mutations in NSCLC

  13. Determination of activated plasma fibronectin using radioactive labelled collagen I

    DEFF Research Database (Denmark)

    Fenger, M

    1984-01-01

    The plasma concentration of biological active fibronectin was assayed by a protein binding assay using 125I-collagen I as ligand and heparin as activator. The standard curve is linear for a fibronectin range of 1.1-11 pmol (0.5-5.0 micrograms) and the coefficient of variation was less than 10......%. The active or activable fibronectin was compared to the immunoreactive fibronectin in plasma from patients with various bacterial diseases. Similar concentrations were detected by the two assays suggesting that all the circulating fibronectin was functionally active. The assay was also applied to determine...... the structure-function relationship of heparin and heparansulphate in activation of fibronectin. Low-sulphated heparansulphate from umbilical cords and heparin-activated fibronectin but the effect was uncorrelated to anticoagulation activity. Only a small fraction of the heparin was actually capable...

  14. Abrogating phosphorylation of eIF4B is required for EGFR and mTOR inhibitor synergy in triple-negative breast cancer

    Science.gov (United States)

    Madden, Julie M; Mueller, Kelly L; Bollig-Fischer, Aliccia; Stemmer, Paul; Mattingly, Raymond R; Boerner, Julie L

    2014-01-01

    Purpose Triple negative breast cancer (TNBC) patients suffer from a highly malignant and aggressive disease. They have a high rate of relapse and often develop resistance to standard chemotherapy. Many TNBCs have elevated epidermal growth factor receptor (EGFR) but are resistant to EGFR inhibitors as monotherapy. In this study we sought to find a combination therapy that could sensitize TNBC to EGFR inhibitors. Methods Phospho-mass spectrometry was performed on the TNBC cell line, BT20, treated with 0.5 μM gefitinib. Immunoblotting measured protein levels and phosphorylation. Colony formation and growth assays analyzed the treatment on cell proliferation while MTT assays determined the synergistic effect of inhibitor combination. A dual luciferase reporter gene plasmid measured translation. All statistical analysis was done on CalucuSyn and GraphPad Prism using ANOVAs. Results Phospho-proteomics identified the mTOR pathway to be of interest in EGFR inhibitor resistance. In our studies, combining gefitinib and temsirolimus decreased cell growth and survival in a synergistic manner. Our data identified eIF4B, as a potentially key fragile point in EGFR and mTOR inhibitor synergy. Decreased eIF4B phosphorylation correlated with drops in growth, viability, clonogenic survival, and cap-dependent translation. Conclusions Taken together these data suggest EGFR and mTOR inhibitors abrogate growth, viability, and survival via disruption of eIF4B phosphorylation leading to decreased translation in TNBC cell lines. Further, including an mTOR inhibitor along with an EGFR inhibitor in TNBC with increased EGFR expression should be further explored. Additionally, translational regulation may play in important role in regulating EGFR and mTOR inhibitor synergy and warrants further investigation. PMID:25129346

  15. Determination of superoxide dismutase mimetic activity in common culinary herbs.

    Science.gov (United States)

    Chohan, Magali; Naughton, Declan P; Opara, Elizabeth I

    2014-01-01

    Under conditions of oxidative stress, the removal of superoxide, a free radical associated with chronic inflammation, is catalysed by superoxide dismutase (SOD). Thus in addition to acting as an antioxidant, SOD may also be utilized as an anti-inflammatory agent. Some plant derived foods have been shown to have SOD mimetic (SODm) activity however it is not known if this activity is possessed by culinary herbs which have previously been shown to possess both antioxidant and anti-inflammatory properties. The aim of the study was to ascertain if the culinary herbs rosemary, sage and thyme possess SODm activity, and to investigate the influence of cooking and digestion on this activity. Transition metal ion content was also determined to establish if it could likely contribute to any SODm activity detected. All extracts of uncooked (U), cooked (C) and cooked and digested (C&D) herbs were shown to possess SODm activity, which was significantly correlated with previously determined antioxidant and anti-inflammatory activities of these herbs. SODm activity was significantly increased following (C) and (C&D) for rosemary and sage only. The impact of (C) and (C&D) on the SODm for thyme may have been influenced by its transition metal ion content. SODm activity may contribute to the herbs' antioxidant and anti-inflammatory activities however the source and significance of this activity need to be established.

  16. Development of method for the mineral water catalase activity determination

    Directory of Open Access Journals (Sweden)

    Olena М. Nikipelova

    2015-03-01

    Full Text Available Biological effects of mineral water depend not only on the chemical composition but also on the metabolic products of microbial cenosis. Among numerous microorganisms constituting the autochthonous microflora of mineral waters, we do evolve the saprophytic organisms producing the catalase, the saprophytes’ physiological and biological role being proven a long ago. The research aim was to develop a method for determination of mineral water catalase activity. Analyzed are various methods to determine the catalase activity in biological objects. Developed is a spectrophotometric method for determination of mineral water catalase activity. The method is efficiently tested with series of Ukrainian mineral waters. Calculated are the relative standard deviations which are significantly below normal errors, admitted at spectroscopic analysis and at the optic density range. The given method provides sufficient accuracy and convergence when estimating the mineral waters catalase activity, allowing to introduce a new index to assess the quality and biological value.

  17. Serum ZAG Levels Were Associated with eGFR Mild Decrease in T2DM Patients with Diabetic Nephropathy.

    Science.gov (United States)

    Xu, Lingling; Yu, Weihong; Niu, Meng; Zheng, Caixia; Qu, Bin; Li, Yan; Wang, Jing; Huang, Ping; Wang, O; Gong, Fengying

    2017-01-01

    Objective. To investigate the changes of serum zinc-α2-glycoprotein (ZAG) in type 2 diabetes mellitus (T2DM) with eGFR mild decrease. Subjects and Methods. A total of 438 T2DM patients (61.3 ± 4.0 y) were recruited and the demographic, anthropometric, and biochemical parameters were all collected. Serum ZAG levels were determined by commercially available ELISA kits. Results. The proportion of T2DM patients with the high tertile ZAG levels was 11.9% higher in patients with mildly decreased estimated glomerular filtration rate (eGFR) (ZAG levels (P = 0.038). The probability of the eGFR ZAG levels was 94% higher than those with the low serum ZAG levels after adjusting for age, gender, and education [OR = 1.94, 95% CI (1.17-3.23), P = 0.0094]. This phenomenon was more likely to be observed in the condition of uACR ≥ 2.7 mg/mmol, WC ≥ 90 cm for men, or WC ≥ 85 cm for women. Conclusion. Serum ZAG levels were firstly found to be related with eGFR in T2DM patients. The patients with the high tertile ZAG levels were more likely to have mildly eGFR decrease, especially for female patients with higher uACR and bigger WC.

  18. Propofol enhances the cisplatin-induced apoptosis on cervical cancer cells via EGFR/JAK2/STAT3 pathway.

    Science.gov (United States)

    Li, Haoran; Lu, Yan; Pang, Yangyang; Li, Mengjiao; Cheng, Xi; Chen, Jiawei

    2017-02-01

    The main purpose of this study was to evaluate propofol and its combined effect with cisplatin on apoptosis of cervical cancer cells and molecular mechanisms of this phenomenon. The effects of propofol and cisplatin on cell viability and apoptosis were detected by cell counting kit-8 (CCK-8) assay, colony formation assay and flow cytometry assay. Besides, protein expression of EGFR/JAK2/STAT3 pathway was determined by western blot. STAT3 was over-expressed in cervical cancer cells by STAT3 cDNA. Expression of EGFR and STAT3 protein of human tissues was evaluated by immunohistochemistry (IHC) assay. In this study, we found that not only propofol alone could inhibit cervical cancer cells viability but also could increase the inhibitory effect of cisplatin on cervical cancer cells growth. Meanwhile, propofol sensitized cervical cancer cells to cisplatin-induced apoptosis but not affected normal cervical cells. In genetic level, propofol could enhance the anti-tumor effect of cisplatin through EGFR/JAK2/STAT3 pathway. Further studies indicated that overexpression of EGFR and STAT3 is related to poor prognoses in cervical cancer patients, which contributed to confirm the clinical role of combined application of propofol and cisplatin. Propofol enhances the cisplatin-induced cell apoptosis cervical cancer cells via EGFR/JAK2/STAT3 pathway and may be developed as a potential therapeutic agent to treat cervical cancer. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  19. Crosstalk between EGFR and integrin affects invasion and proliferation of gastric cancer cell line, SGC7901

    Directory of Open Access Journals (Sweden)

    Dan L

    2012-10-01

    Full Text Available Li Dan,1,* Ding Jian,2,* Lin Na,1 Wang Xiaozhong,1 1Digestive Department, the Union Hospital of Fujian Medical University, Fujian, People’s Republic of China; 2Digestive Department, the First Affiliated Hospital of Fujian Medical University, Fuzhou, Fujian, People’s Republic of China*These authors contributed equally to this workBackground/objective: To investigate the crosstalk between epidermal growth factor receptor (EGFR and integrin-mediated signal transduction pathways in human gastric adenocarcinoma cells.Methods: EGF was used as a ligand of EGFR to stimulate the gastric adenocarcinoma cell, SGC7901. Signal molecules downstream of the integrin, FAK(Y397 and p130cas(Y410 phosphorylation, were measured by immunoprecipitation and western blot. Fibronectin (Fn was used as a ligand of integrin to stimulate the same cell line. Signal molecules downstream of EGFR and extracellular signal-regulated kinase (ERK general phosphorylation were also measured. Focal adhesion kinase (FAK small-interfering RNA was designed and transfected into SGC7901 cells to decrease the expression of FAK. Modified Boyden chambers and MTT assay were used to examine the effect of FAK inhibition on the invasiveness and proliferation of SGC7901.Results: EGF activated FAK(Y397 and p130cas(Y410 phosphorylation, while Fn activated ERK general phosphorylation. Inhibition of FAK expression decreased p130cas(Y410 phosphorylation activated by EGF and ERK general phosphorylation activated by Fn, also decreased the invasiveness and proliferation of SGC7901 cells activated by EGF or Fn.Conclusion: There is crosstalk between EGFR and integrin signal transduction. FAK may be a key cross point of the two signal pathways and acts as a potential target for human gastric cancer therapy.Keywords: gastric adenocarcinoma, epidermal growth factor receptor, integrin, focal adhesion kinase, crosstalk

  20. PD-1 Axis Inhibitors in EGFR- and ALK-Driven Lung Cancer: Lost Cause?

    Science.gov (United States)

    Gettinger, Scott; Politi, Katerina

    2016-09-15

    Programmed death axis 1 (PD-1) inhibitors have ushered in a new error of cancer immunotherapeutics for advanced smoking-associated non-small cell lung cancer. Their role in treating EGFR-mutant and ALK-rearranged lung cancer has yet to be determined. Clin Cancer Res; 22(18); 4539-41. ©2016 AACRSee related article by Gainor et al., p. 4585. ©2016 American Association for Cancer Research.

  1. Oncogenic EGFR Represses the TET1 DNA Demethylase to Induce Silencing of Tumor Suppressors in Cancer Cells

    Directory of Open Access Journals (Sweden)

    Matteo Forloni

    2016-07-01

    Full Text Available Oncogene-induced DNA methylation-mediated transcriptional silencing of tumor suppressors frequently occurs in cancer, but the mechanism and functional role of this silencing in oncogenesis are not fully understood. Here, we show that oncogenic epidermal growth factor receptor (EGFR induces silencing of multiple unrelated tumor suppressors in lung adenocarcinomas and glioblastomas by inhibiting the DNA demethylase TET oncogene family member 1 (TET1 via the C/EBPα transcription factor. After oncogenic EGFR inhibition, TET1 binds to tumor suppressor promoters and induces their re-expression through active DNA demethylation. Ectopic expression of TET1 potently inhibits lung and glioblastoma tumor growth, and TET1 knockdown confers resistance to EGFR inhibitors in lung cancer cells. Lung cancer samples exhibited reduced TET1 expression or TET1 cytoplasmic localization in the majority of cases. Collectively, these results identify a conserved pathway of oncogenic EGFR-induced DNA methylation-mediated transcriptional silencing of tumor suppressors that may have therapeutic benefits for oncogenic EGFR-mediated lung cancers and glioblastomas.

  2. Amiodarone Induces Overexpression of Similar to Versican b to Repress the EGFR/Gsk3b/Snail Signaling Axis during Cardiac Valve Formation of Zebrafish Embryos.

    Science.gov (United States)

    Lee, Hung-Chieh; Lo, Hao-Chan; Lo, Dao-Ming; Su, Mai-Yan; Hu, Jia-Rung; Wu, Chin-Chieh; Chang, Sheng-Nan; Dai, Ming-Shen; Tsai, Chia-Ti; Tsai, Huai-Jen

    2015-01-01

    Although Amiodarone, a class III antiarrhythmic drug, inhibits zebrafish cardiac valve formation, the detailed molecular pathway is still unclear. Here, we proved that Amiodarone acts as an upstream regulator, stimulating similar to versican b (s-vcanb) overexpression at zebrafish embryonic heart and promoting cdh-5 overexpression by inhibiting snail1b at atrioventricular canal (AVC), thus blocking invagination of endocardial cells and, as a result, preventing the formation of cardiac valves. A closer investigation showed that an intricate set of signaling events ultimately caused the up-regulation of cdh5. In particular, we investigated the role of EGFR signaling and the activity of Gsk3b. It was found that knockdown of EGFR signaling resulted in phenotypes similar to those of Amiodarone-treated embryos. Since the reduced phosphorylation of EGFR was rescued by knockdown of s-vcanb, it was concluded that the inhibition of EGFR activity by Amiodarone is s-vcanb-dependent. Moreover, the activity of Gsk3b, a downstream effector of EGFR, was greatly increased in both Amiodarone-treated embryos and EGFR-inhibited embryos. Therefore, it was concluded that reduced EGFR signaling induced by Amiodarone treatment results in the inhibition of Snail functions through increased Gsk3b activity, which, in turn, reduces snail1b expression, leading to the up-regulation the cdh5 at the AVC, finally resulting in defective formation of valves. This signaling cascade implicates the EGFR/Gsk3b/Snail axis as the molecular basis for the inhibition of cardiac valve formation by Amiodarone.

  3. Phase I/II clinical and pharmacokinetic study evaluating a fully human monoclonal antibody against EGFr (HuMax-EGFr) in patients with advanced squamous cell carcinoma of the head and neck

    DEFF Research Database (Denmark)

    Bastholt, Lars; Specht, Lena; Jensen, Kenneth

    2007-01-01

    PURPOSE: To assess safety, tolerability, pharmacokinetics and clinical activity of HuMax-EGFr in patients with SCCHN. PATIENTS AND METHODS: Twenty-eight patients with SCCHN were enrolled. The study comprised a single-dose escalation part for assessment of safety issues followed by a repeat dose...... reactions varied from few days to 2 months. No DLTs were observed and MTD was not reached. In the two highest dose groups, 7 of 11 patients obtained a PR or SD and 9 patients obtained metabolic PR or SD. CONCLUSIONS: HuMax-EGFr can be safely administered in doses up to 8 mg/kg, and preliminary data...

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

    OpenAIRE

    Shi, Tujin; Niepel, Mario; McDermott, Jason E.; Gao, Yuqian; Nicora, Carrie D.; Chrisler, William B.; Markillie, Lye M.; Petyuk, Vladislav A.; Smith, Richard D; Rodland, Karin D.; Sorger, Peter K.; Qian, Wei-Jun; Wiley, H. Steven

    2016-01-01

    Various genetic mutations associated with cancer are known to alter cell signaling, but it is not clear whether they dysregulate signaling pathways by altering the abundance of pathway proteins. Using a combination of RNA sequencing and ultrasensitive targeted proteomics, we defined the primary components—16 core proteins and 10 feedback regulators—of the epidermal growth factor receptor (EGFR)–mitogen-activated protein kinase (MAPK) pathway in normal human mammary epithelial cells and then q...

  5. Frequency of EGFR mutations in lung adenocarcinoma with malignant pleural effusion: Implication of cancer biological behaviour regulated by EGFR mutation.

    Science.gov (United States)

    Zou, JianYong; Bella, Amos Ela; Chen, ZhenGuang; Han, XiangQian; Su, ChunHua; Lei, YiYan; Luo, HongHe

    2014-10-01

    A retrospective single-centre study to compare the clinical features of patients with lung adenocarcinoma with and without epidermal growth factor receptor (EGFR) mutations. Pretreatment medical records of patients with lung adenocarcinoma were reviewed. DNA was extracted from paraffin wax-embedded tumour tissue for analysis of EGFR mutations. Malignant pleural effusion (MPE) was diagnosed by cytopathological testing of pleural fluid. EGFR mutations (19-Del and L858R) were recorded in 81/283 patients (28.6%). MPE was found in 42/283 patients (14.8%). In patients with stage IV disease, the frequency of EGFR mutations was higher in those with MPE than in those without MPE. EGFR mutations were independently associated with female sex, no history of smoking and presence of MPE. There was a positive association between EGFR mutation and the presence of MPE. EGFR mutations may play an important role in the formation of MPE. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

  6. Direct determination of phosphatase activity from physiological substrates in cells.

    Directory of Open Access Journals (Sweden)

    Zhongyuan Ren

    Full Text Available A direct and continuous approach to determine simultaneously protein and phosphate concentrations in cells and kinetics of phosphate release from physiological substrates by cells without any labeling has been developed. Among the enzymes having a phosphatase activity, tissue non-specific alkaline phosphatase (TNAP performs indispensable, multiple functions in humans. It is expressed in numerous tissues with high levels detected in bones, liver and neurons. It is absolutely required for bone mineralization and also necessary for neurotransmitter synthesis. We provided the proof of concept that infrared spectroscopy is a reliable assay to determine a phosphatase activity in the osteoblasts. For the first time, an overall specific phosphatase activity in cells was determined in a single step by measuring simultaneously protein and substrate concentrations. We found specific activities in osteoblast like cells amounting to 116 ± 13 nmol min(-1 mg(-1 for PPi, to 56 ± 11 nmol min(-1 mg(-1 for AMP, to 79 ± 23 nmol min(-1 mg(-1 for beta-glycerophosphate and to 73 ± 15 nmol min(-1 mg(-1 for 1-alpha-D glucose phosphate. The assay was also effective to monitor phosphatase activity in primary osteoblasts and in matrix vesicles. The use of levamisole--a TNAP inhibitor--served to demonstrate that a part of the phosphatase activity originated from this enzyme. An IC50 value of 1.16 ± 0.03 mM was obtained for the inhibition of phosphatase activity of levamisole in osteoblast like cells. The infrared assay could be extended to determine any type of phosphatase activity in other cells. It may serve as a metabolomic tool to monitor an overall phosphatase activity including acid phosphatases or other related enzymes.

  7. Direct determination of phosphatase activity from physiological substrates in cells.

    Science.gov (United States)

    Ren, Zhongyuan; Do, Le Duy; Bechkoff, Géraldine; Mebarek, Saida; Keloglu, Nermin; Ahamada, Saandia; Meena, Saurabh; Magne, David; Pikula, Slawomir; Wu, Yuqing; Buchet, René

    2015-01-01

    A direct and continuous approach to determine simultaneously protein and phosphate concentrations in cells and kinetics of phosphate release from physiological substrates by cells without any labeling has been developed. Among the enzymes having a phosphatase activity, tissue non-specific alkaline phosphatase (TNAP) performs indispensable, multiple functions in humans. It is expressed in numerous tissues with high levels detected in bones, liver and neurons. It is absolutely required for bone mineralization and also necessary for neurotransmitter synthesis. We provided the proof of concept that infrared spectroscopy is a reliable assay to determine a phosphatase activity in the osteoblasts. For the first time, an overall specific phosphatase activity in cells was determined in a single step by measuring simultaneously protein and substrate concentrations. We found specific activities in osteoblast like cells amounting to 116 ± 13 nmol min(-1) mg(-1) for PPi, to 56 ± 11 nmol min(-1) mg(-1) for AMP, to 79 ± 23 nmol min(-1) mg(-1) for beta-glycerophosphate and to 73 ± 15 nmol min(-1) mg(-1) for 1-alpha-D glucose phosphate. The assay was also effective to monitor phosphatase activity in primary osteoblasts and in matrix vesicles. The use of levamisole--a TNAP inhibitor--served to demonstrate that a part of the phosphatase activity originated from this enzyme. An IC50 value of 1.16 ± 0.03 mM was obtained for the inhibition of phosphatase activity of levamisole in osteoblast like cells. The infrared assay could be extended to determine any type of phosphatase activity in other cells. It may serve as a metabolomic tool to monitor an overall phosphatase activity including acid phosphatases or other related enzymes.

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

    Science.gov (United States)

    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.

  9. Radiosensitivity and TP 53, EGFR amplification and LOH10 analysis of primary glioma cell cultures

    Energy Technology Data Exchange (ETDEWEB)

    Gerlach, B. [Dept. of Radiation Oncology, VU Univ. Medical Center, Amsterdam (Netherlands); Dept. of Radiation Oncology, Univ. of Duesseldorf (Germany); Harder, A.H.; Slotman, B.J.; Sminia, P. [Dept. of Radiation Oncology, VU Univ. Medical Center, Amsterdam (Netherlands); Hulsebos, T.J.M. [Dept. of Human Genetics, Academic Medical Center, Amsterdam (Netherlands); Leenstra, S. [Dept. of Neurosurgery, Academic Medical Center, Amsterdam (Netherlands); Peter Vandertop, W. [Dept. of Neurosurgery, VU Univ. Medical Center, Amsterdam (Netherlands); Hartmann, K.A. [Dept. of Radiation Oncology, Univ. of Duesseldorf (Germany)

    2002-09-01

    Aim: Determination of in-vitro radiosensitivity and genetic alterations of cell cultures derived from human glioma biopsy tissue and established glioma cell lines. Material and Methods: Fresh brain tumor specimens of six patients were processed to early passage cell cultures. In addition the cell lines D 384 and Gli 6 were used. Cell cultures were irradiated with doses from 2 to 10 Gy. Following irradiation, cell survival was determined by clonogenic assay and survival curves were generated. The surviving fractions after 2 Gy (SF2) and 4 Gy (SF4) were used as radiosensitivity parameters. Genetic analysis included determination of the mutational and loss of heterozygosity (LOH) status of TP 53 (exons 5-8), the LOH 10- and epidermal growth factor receptor gene (EGFR) amplification status. Results: The SF2 and SF4 values ranged from 0.54 to 0.88 (mean: 0.70) and from 0.13 to 0.52 (mean: 0.32), respectively. Genetic alterations were found in the Gli 6 cell line and in two primary cell cultures. The genetic profile of Gli 6 showed LOH but no TP 53 mutation, complete LOH 10 and no EGFR amplification. The VU 15 cell culture showed TP 53 mutation but no LOH 10 or EGFR amplification, while VU 24 showed incomplete LOH 10, EGFR amplification and no TP 53 mutation. In the other four cell cultures and D 384 cell line no genetic alterations were diagnosed. Histopathological classification of glioblastoma multiforme and/or genetic alterations resulted in lower radiosensitivity. Conclusion: In this small series of early passage glioma cell cultures low radiosensitivity and alterations in cell regulatory genes were seen. Further testing of biological behavior in larger series of patient-derived material is ongoing. (orig.)

  10. EGFR and EGFRvIII Promote Angiogenesis and Cell Invasion in Glioblastoma: Combination Therapies for an Effective Treatment

    Directory of Open Access Journals (Sweden)

    Stefanie Keller

    2017-06-01

    Full Text Available Epidermal growth factor receptor (EGFR and the mutant EGFRvIII are major focal points in current concepts of targeted cancer therapy for glioblastoma multiforme (GBM, the most malignant primary brain tumor. The receptors participate in the key processes of tumor cell invasion and tumor-related angiogenesis and their upregulation correlates with the poor prognosis of glioma patients. Glioma cell invasion and increased angiogenesis share mechanisms of the degradation of the extracellular matrix (ECM through upregulation of ECM-degrading proteases as well as the activation of aberrant signaling pathways. This review describes the role of EGFR and EGFRvIII in those mechanisms which might offer new combined therapeutic approaches targeting EGFR or EGFRvIII together with drug treatments against proteases of the ECM or downstream signaling to increase the inhibitory effects of mono-therapies.

  11. EGFR testing and clinical management of advanced NSCLC: a Galician Lung Cancer Group study (GGCP 048-10

    Directory of Open Access Journals (Sweden)

    Vázquez S

    2016-02-01

    %, respectively. All but two patients received gefitinib. Median progression-free survival and overall survival were 10 (95% confidence interval: 4.8–15.3 months and 17.8 (95% confidence interval: 13.9–21.6 months, respectively, in patients carrying sensitizing mutations. Conclusion: The incidence of EGFR mutations in Galicia is consistent with previous data in Spain. Our results also support the feasibility of EGFR testing to guide treatment decision making using tumor tissue or cytology samples, or serum samples if tumor specimens are unavailable. These findings also confirm that first-line gefitinib is an active treatment option in Caucasians with EGFR mutation-positive NSCLC. Keywords: epidermal growth factor receptor, EGFR tyrosine inhibitors, TKIs, EGFR gene mutation, EGFR mutation testing, non-small-cell lung cancer

  12. Determinants of Foreign Technological Activity in German Regions

    DEFF Research Database (Denmark)

    Dettmann, Eva; Lacasa, Iciar Dominguez; Günther, Jutta

    This paper analyses the determinants of spatial distribution of foreign technological activity across 96 German regions (1996-2009). We identify foreign inventive activity by applying the ‘cross-border-ownership concept’ to transnational patent applications. The descriptive analysis shows...... that foreign technological activity more than doubled during the observation period with persistent spatial heterogeneity in Germany. Using a pooled count data model, we estimate the effect of various sources for externalities on the extent of foreign technological activity across regions. Our results show...... that foreign technological activity is attracted by technologically specialised sectors of regions. In contrast to existing findings this effect applies both to foreign as well as domestic sources of specialisation. We show that the relation between specialization and foreign technological activity is non...

  13. EGFR gene copy number predicts response to anti-EGFR treatment in RAS wild type and RAS/BRAF/PIK3CA wild type metastatic colorectal cancer.

    Science.gov (United States)

    Ålgars, Annika; Sundström, Jari; Lintunen, Minnamaija; Jokilehto, Terhi; Kytölä, Soili; Kaare, Milja; Vainionpää, Reetta; Orpana, Arto; Österlund, Pia; Ristimäki, Ari; Carpen, Olli; Ristamäki, Raija

    2017-02-15

    Anti-EGFR antibodies are used for the treatment of RAS wild type metastatic colorectal cancer. We previously showed that EGFR gene copy number (GCN) predicts response to anti-EGFR therapy in KRAS exon 2 wild type metastatic colorectal cancer. The aim of our study was to analyse the predictive role of EGFR GCN in RAS/BRAF/PIK3CA wild type metastatic colorectal cancer. The material included 102 patients with KRAS exon 2 wild type metastatic colorectal cancer treated with anti-EGFR ± cytotoxic therapy. Next generation sequencing was used for KRAS, NRAS, BRAF and PIK3CA gene mutation analyses. EGFR GCN was analysed by EGFR immunohistochemistry guided automated silver in situ hybridisation. Increased EGFR GCN (≥4.0) predicted a better response and prolonged progression free survival in anti-EGFR treated RAS/BRAF/PIK3CA wild type patients (Log-rank test, p = 0.0004). In contrast, survival of RAS/BRAF/PIK3CA wild type, EGFR GCN below 4.0 patients did not differ from patients with mutant RAS, BRAF or PIK3CA. Our study indicates that EGFR GCN predicts anti-EGFR treatment efficacy in patients with RAS/BRAF/PIK3CA wt metastatic CRC. Tumours with EGFR GCN below 4.0 appear to be as refractory to anti-EGFR treatment as tumours with mutation in any of the RAS/RAF/PIK3CA pathway genes. © 2016 UICC.

  14. EGFR transactivation contributes to neuroinflammation in Streptococcus suis meningitis.

    Science.gov (United States)

    Yang, Xiao-Pei; Fu, Ji-Yang; Yang, Rui-Cheng; Liu, Wen-Tong; Zhang, Tao; Yang, Bo; Miao, Ling; Dou, Bei-Bei; Tan, Chen; Chen, Huan-Chun; Wang, Xiang-Ru

    2016-10-19

    Streptococcus suis serotype 2 (SS2) is an important zoonotic bacterial pathogen in both humans and animals, which can cause high morbidity and mortality. Meningitis is one of the major clinical manifestations of SS2 infection. However, the specific process of SS2 meningitis and its molecular mechanisms remain unclear. Epidermal growth factor receptor (EGFR) has been reported to initiate transduction of intracellular signals and regulate host inflammatory responses. Whether and how EGFR contributes to the development of S. suis meningitis are currently unknown. The tyrosine phosphorylation of cellular proteins, the transactivation of EGFR, as well as its dimerization, and the associated signal transduction pathways were investigated by immunoprecipitation and western blotting. Real-time quantitative PCR was used to investigate the transcriptional level of the ErbB family members, EGFR-related ligands, cytokines, and chemokines. The secretion of cytokines and chemokines in the serum and brain were detected by Q-Plex™ Chemiluminescent ELISA. We found an important role of EGFR in SS2 strain SC19-induced meningitis. SC19 increasingly adhered to human brain microvascular endothelial cells (hBMEC) and caused inflammatory lesions in the brain tissues, with significant induction and secretion of proinflammatory cytokines and chemokines in the serum and brains. SC19 infection of hBMEC induced tyrosine phosphorylation of cellular EGFR in a ligand-dependent manner involving the EGF-like ligand HB-EGF, amphiregulin (AREG), and epiregulin (EREG) and led to heterodimerization of EGFR/ErbB3. The EGFR transactivation did not participate in SS2 strain SC19 adhesion of hBMEC, as well as in bacterial colonization in vivo. However, its transactivation contributed to the bacterial-induced neuroinflammation, via triggering the MAPK-ERK1/2 and NF-κB signaling pathways in hBMEC that promote the production of proinflammatory cytokines and chemokines. We investigated for the first time

  15. Methods for determining keratinolytic activity of saprophytic fungi

    Directory of Open Access Journals (Sweden)

    Teresa Korniłłowicz

    2014-08-01

    Full Text Available In order to evaluate tbe keratinolytic activity of saprophytic microfungi the following values were determined, the percentage keratin substrate decomposition (native feathers. the changes of pH of medium the liberation of peptidic substances in this process, as well as the liberation of amine nitrogen and cystein. The presence of keratinase was examined in culture filtrates and the proteolytic activity in the presence of casein. It was noted that among the above mentioned indices the percentage decrease of substrate mass was the most useful criterion of keratinolytic activity evaluation.

  16. Detection of wild-type EGFR amplification and EGFRvIII mutation in CSF-derived extracellular vesicles of glioblastoma patients.

    Science.gov (United States)

    Figueroa, Javier M; Skog, Johan; Akers, Johnny; Li, Hongying; Komotar, Ricardo; Jensen, Randy; Ringel, Florian; Yang, Isaac; Kalkanis, Steven; Thompson, Reid; LoGuidice, Lori; Berghoff, Emily; Parsa, Andrew; Liau, Linda; Curry, William; Cahill, Daniel; Bettegowda, Chetan; Lang, Frederick F; Chiocca, E Antonio; Henson, John; Kim, Ryan; Breakefield, Xandra; Chen, Clark; Messer, Karen; Hochberg, Fred; Carter, Bob S

    2017-10-19

    RNAs within extracellular vesicles (EVs) have potential as diagnostic biomarkers for patients with cancer and are identified in a variety of biofluids. Glioblastomas (GBMs) release EVs containing RNA into cerebrospinal fluid (CSF). Here we describe a multi-institutional study of RNA extracted from CSF-derived EVs of GBM patients to detect the presence of tumor-associated amplifications and mutations in epidermal growth factor receptor (EGFR). CSF and matching tumor tissue were obtained from patients undergoing resection of GBMs. We determined wild-type (wt)EGFR DNA copy number amplification, as well as wtEGFR and EGFR variant (v)III RNA expression in tumor samples. We also characterized wtEGFR and EGFRvIII RNA expression in CSF-derived EVs. EGFRvIII-positive tumors had significantly greater wtEGFR DNA amplification (P = 0.02) and RNA expression (P = 0.03), and EGFRvIII-positive CSF-derived EVs had significantly more wtEGFR RNA expression (P = 0.004). EGFRvIII was detected in CSF-derived EVs for 14 of the 23 EGFRvIII tissue-positive GBM patients. Conversely, only one of the 48 EGFRvIII tissue-negative patients had the EGFRvIII mutation detected in their CSF-derived EVs. These results yield a sensitivity of 61% and a specificity of 98% for the utility of CSF-derived EVs to detect an EGFRvIII-positive GBM. Our results demonstrate CSF-derived EVs contain RNA signatures reflective of the underlying molecular genetic status of GBMs in terms of wtEGFR expression and EGFRvIII status. The high specificity of the CSF-derived EV diagnostic test gives us an accurate determination of positive EGFRvIII tumor status and is essentially a less invasive "liquid biopsy" that might direct mutation-specific therapies for GBMs.

  17. Esophageal Cancer and the Importance of Epidermal Growth Factor (EGFR

    Directory of Open Access Journals (Sweden)

    Kazem Anvari

    2014-04-01

    Full Text Available Esophageal squamous cell carcinoma (ESCC is one of the most frequent malignancies, worldwide. It is important to find out what prognostic factors can facilitate diagnosis, optimize therapeutic decisions, and improve the survival of these patients. Despite improvements in surgical techniques combined with chemotherapy and/or radiotherapy, the novel therapies such as small molecule inhibitors of tyrosine kinases (TKIs and humanized monoclonal antibodies (mAbs are very much needed. On the other hand, neoadjuvant chemotherapy which may improve the outcome is accompanied by toxicity by destruction of normal cells. Side effects may be avoided by developing therapies that specifically target molecular characteristics of tumors. Epidermal growth factor receptor (EGFR is one of tyrosine kinases receptors widely distributed in human epithelial cell membrane. Genetic polymorphisms in EGFR genes influence cell cycle progression, angiogenesis, apoptosis and metastasis. EGFR mutations are mostly observed in lung tumors; curiously they are more prevalent in Asian women diagnosed with adenocarcinoma. Also, esophageal SCC shows a relatively high incidence of EGFR (33% and/or HER2 (31% overexpression. Patients who carry these mutations in EGFR have been founded tending to have a better response to gefitinib, an EGFR-TKI, whereas patients with the wild-type genotype show a better response to conventional chemotherapy. Therefore, finding clinical characteristics and environmental interactions with EGFR can affect on investigations about novel anti-cancer therapies like monoclonal antibodies and gene therapy and studies which identify patients who may benefit from EGFR targeted therapies. Hence, it may be effective on the improvement of prognosis in these patients.

  18. Physical Activity And Dietary Fat As Determinants Of Body Mass ...

    African Journals Online (AJOL)

    Overweight/obesity and related disease conditions will constitute a major threat to the economically productive adults and subsequently, will present a huge health-care burden on developing countries in the near future. Suspected determinants include physical activity and dietary fat. The main indicator of ...

  19. Determination of secondary metabolites and antioxidant activity of ...

    African Journals Online (AJOL)

    Butylated hydroxyanisole (BHA), Folin-Ciocalteu, methanol, sodium acetate, aluminium chloride and ethanol were ... The BHA was used as a standard reference. Antioxidant activity (D) was determined as in Eq 1. .... cancer and cardiovascular diseases and as well as inhibit the development of diabetes mellitus. [21].

  20. Determination of antimicrobial activity and production of some ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-12-17

    Dec 17, 2008 ... Determination of antimicrobial activity and production of some metabolites by Pseudomonas aeruginosa B1 and B2 in sugar beet molasses. Dilsad Onbasli1* and Belma Aslim2. 1Kastamonu University, Faculty of Science and Arts, Department of Biology, 37100, Kastamonu-Turkey. 2Gazi University, Faculty ...

  1. 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

  2. [Method of determining tissue renin activity using heterologous serum].

    Science.gov (United States)

    Orbetsova, V Ts; Kiprov, D

    1979-01-01

    The authors described a method for determination of tissue renin activity with heterologous substrate. The preparation of the substrate was performed at several stages: salting with amonium sulfate; dialisis of the precipitate till complete separation of amonium sulfate molecules; distruction of angiotensinases by interchangeble souring and alcalization of the medium; lyophylization of the pure substrate. The obtained renin-substrate was preserved in ampules and its usage had a series of advantages--duration, economic, a possibility for standartization of the determination, etc., which were described in details in the article. The described in details also the quantitative determination of the renin activity in the tissues (renal and cerebral) with the help of the obtained substrate as the moments, modiied by the authors, were indicated.

  3. A general method for determining secondary active transporter substrate stoichiometry.

    Science.gov (United States)

    Fitzgerald, Gabriel A; Mulligan, Christopher; Mindell, Joseph A

    2017-01-25

    The number of ions required to drive substrate transport through a secondary active transporter determines the protein's ability to create a substrate gradient, a feature essential to its physiological function, and places fundamental constraints on the transporter's mechanism. Stoichiometry is known for a wide array of mammalian transporters, but, due to a lack of readily available tools, not for most of the prokaryotic transporters for which high-resolution structures are available. Here, we describe a general method for using radiolabeled substrate flux assays to determine coupling stoichiometries of electrogenic secondary active transporters reconstituted in proteoliposomes by measuring transporter equilibrium potentials. We demonstrate the utility of this method by determining the coupling stoichiometry of VcINDY, a bacterial Na + -coupled succinate transporter, and further validate it by confirming the coupling stoichiometry of vSGLT, a bacterial sugar transporter. This robust thermodynamic method should be especially useful in probing the mechanisms of transporters with available structures.

  4. Determinant factors of peak treadmill speed in physically active men.

    Science.gov (United States)

    Alves Pasqua, Leonardo; Damasceno, Mayara V; Bueno, Salomão; Zagatto, Alessandro M; DE Araújo, Gustavo G; Lima-Silva, Adriano E; Bertuzzi, Rômulo

    2016-11-30

    The aim of the present study was to determine whether physiological factors and maximal dynamic strength are able to determine the peak treadmill speed (PTS) in physically active individuals. One hundred and fifty physically active healthy males voluntarily visit the laboratory on three separate occasions and underwent the following activities: first visit: IPAQ (short version), anthropometric measurements, and a maximal incremental test performed for physiological variables (maximal oxygen uptake ( ) and respiratory compensation point (RCP); second visit: constant speed test for running economy (RE) measurement, and familiarization with the maximum dynamic strength (1RM) test in the leg press exercise; third visit: 1RM test. The stepwise multiple regression model selected four independent variables to predict PTS (RCP, , RE, and 1RM). RCP explained 59% (p < 0.001) of variance in PTS, whereas , RE and 1RM accounted for additional 8% (p < 0.001), 4% (p < 0.001), and 1.4% (p = 0.038), respectively. In conclusion, the results of the present study demonstrate that PTS, an important predictor of endurance performance, is determined by both physiological (i.e., RCP, and RE) and muscular (1RM) parameters in healthy active individuals. These results demonstrate that, during a physical evaluation, PTS is able to represent physiological and muscular parameters of physically active individuals. This has the advantage during aerobic fitness evaluations of not requiring expensive equipment and specialized software.

  5. Integrated genomic approaches identify upregulation of SCRN1 as a novel mechanism associated with acquired resistance to erlotinib in PC9 cells harboring oncogenic EGFR mutation.

    Science.gov (United States)

    Kim, Nayoung; Cho, Ahye; Watanabe, Hideo; Choi, Yoon-La; Aziz, Meraj; Kassner, Michelle; Joung, Je-Gun; Park, Angela Kyung-Joo; Francis, Joshua M; Bae, Joon Seol; Ahn, Soo-Min; Kim, Kyoung-Mee; Park, Joon Oh; Park, Woong-Yang; Ahn, Myung-Ju; Park, Keunchil; Koo, Jaehyung; Yin, Hongwei Holly; Cho, Jeonghee

    2016-03-22

    Therapies targeting the tyrosine kinase activity of Epidermal Growth Factor Receptor (EGFR) have been proven to be effective in treating a subset of non-small cell lung cancer (NSCLC) patients harboring activating EGFR mutations. Inevitably these patients develop resistance to the EGFR-targeted tyrosine kinase inhibitors (TKIs). Here, we performed integrated genomic analyses using an in vitro system to uncover alternative genomic mechanisms responsible for acquired resistance to EGFR-TKIs. Specifically, we identified 80 genes whose expression is significantly increased in the erlotinib-resistant clones. RNAi-based systematic synthetic lethal screening of these candidate genes revealed that suppression of one upregulated transcript, SCRN1, a secernin family member, restores sensitivity to erlotinib by enhancing inhibition of PI3K/AKT signaling pathway. Furthermore, immunohistochemical analysis revealed increased levels of SCRN1 in 5 of 11 lung tumor specimens from EGFR-TKIs resistant patients. Taken together, we propose that upregulation of SCRN1 is an additional mechanism associated with acquired resistance to EGFR-TKIs and that its suppression serves as a novel therapeutic strategy to overcome drug resistance in these patients.

  6. Association of integrin beta1 and c-MET in mediating EGFR TKI gefitinib resistance in non-small cell lung cancer

    Directory of Open Access Journals (Sweden)

    Ju Lixia

    2013-02-01

    Full Text Available Abstract Although some patients are initially sensitive to epidermal growth factor receptor tyrosine kinase inhibitors (EGFR TKIs, resistance invariably develops. Therefore, it’s very important to study the molecular mechanism of this resistance. In our previous study we found that integrin beta1 can induce EGFR TKIs resistance in non-small cell lung cancer (NSCLC cells. Here we analyzed the association of integrin beta1 and c-MET that is a recognized mechanism of EGFR TKIs resistance in NSCLC to demonstrate the mechanism of integrin beta1 related EGFR TKIs resistance. We found that the ligands of integrin beta1 and c-MET could synergistically promote cell proliferation and their inhibitors could synergistically improve the sensitivity to gfitinib, increase apoptosis, and inhibit the downstream signal transduction: focal adhesion kinase (FAK and AKT. On the other hand, ligand-dependent activation of integrin beta1 could induce EGFR TKIs resistance through activating c-MET and its downstream signals. Thus, it can be concluded that there is crosstalk between integrin beta1 and c-MET and integrin beta1 mediates EGFR TKI resistance associating with c-MET signaling pathway in non-small cell lung cancer.

  7. EGFR-independent autophagy induction with gefitinib and enhancement of its cytotoxic effect by targeting autophagy with clarithromycin in non-small cell lung cancer cells.

    Science.gov (United States)

    Sugita, Shohei; Ito, Kentaro; Yamashiro, Yutaro; Moriya, Shota; Che, Xiao-Fang; Yokoyama, Tomohisa; Hiramoto, Masaki; Miyazawa, Keisuke

    2015-05-22

    Gefitinib (GEF), an inhibitor for EGFR tyrosine kinase, potently induces autophagy in non-small cell lung cancer (NSCLC) cell lines such as PC-9 cells expressing constitutively activated EGFR kinase by EGFR gene mutation as well as A549 and H226 cells with wild-type EGFR. Unexpectedly, GEF-induced autophagy was also observed in non-NSCLC cells such as murine embryonic fibroblasts (MEF) and leukemia cell lines K562 and HL-60 without EGFR expression. Knockout of EGFR gene in A549 cells by CRISPR/Cas9 system still exhibited autophagy induction after treatment with GEF, indicating that the autophagy induction by GEF is not mediated through inhibiting EGFR kinase activity. Combined treatment with GEF and clarithromycin (CAM), a macrolide antibiotic having the effect of inhibiting autophagy flux, enhances the cytotoxic effect in NSCLC cell lines, although treatment with CAM alone exhibits no cytotoxicity. GEF treatment induced up-regulation of endoplasmic reticulum (ER)-stress related genes such as CHOP/GADD153 and GRP78. Knockdown of CHOP in PC-9 cells and Chop-knockout MEF both exhibited less sensitivity to GEF than controls. Addition of CAM in culture medium resulted in further pronounced GEF-induced ER stress loading, while CAM alone exhibited no effect. These data suggest that GEF-induced autophagy functions as cytoprotective and indicates the potential therapeutic possibility of using CAM for GEF therapy. Furthermore, it is suggested that the intracellular signaling for autophagy initiation in response to GEF can be completely dissociated from EGFR, but unknown target molecule(s) of GEF for autophagy induction might exist. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  8. A drosophila model for EGFR-Ras and PI3K-dependent human glioma.

    Directory of Open Access Journals (Sweden)

    Renee D Read

    2009-02-01

    Full Text Available Gliomas, the most common malignant tumors of the nervous system, frequently harbor mutations that activate the epidermal growth factor receptor (EGFR and phosphatidylinositol-3 kinase (PI3K signaling pathways. To investigate the genetic basis of this disease, we developed a glioma model in Drosophila. We found that constitutive coactivation of EGFR-Ras and PI3K pathways in Drosophila glia and glial precursors gives rise to neoplastic, invasive glial cells that create transplantable tumor-like growths, mimicking human glioma. Our model represents a robust organotypic and cell-type-specific Drosophila cancer model in which malignant cells are created by mutations in signature genes and pathways thought to be driving forces in a homologous human cancer. Genetic analyses demonstrated that EGFR and PI3K initiate malignant neoplastic transformation via a combinatorial genetic network composed primarily of other pathways commonly mutated or activated in human glioma, including the Tor, Myc, G1 Cyclins-Cdks, and Rb-E2F pathways. This network acts synergistically to coordinately stimulate cell cycle entry and progression, protein translation, and inappropriate cellular growth and migration. In particular, we found that the fly orthologs of CyclinE, Cdc25, and Myc are key rate-limiting genes required for glial neoplasia. Moreover, orthologs of Sin1, Rictor, and Cdk4 are genes required only for abnormal neoplastic glial proliferation but not for glial development. These and other genes within this network may represent important therapeutic targets in human glioma.

  9. Erlotinib Versus Radiation Therapy for Brain Metastases in Patients With EGFR-Mutant Lung Adenocarcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Gerber, Naamit K.; Yamada, Yoshiya; Rimner, Andreas [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Shi, Weiji [Department of Epidemiology and Biostatistics, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Riely, Gregory J. [Department of Medicine, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Beal, Kathryn [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Yu, Helena A. [Department of Medicine, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Chan, Timothy A. [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Zhang, Zhigang [Department of Epidemiology and Biostatistics, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Wu, Abraham J., E-mail: wua@mskcc.org [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States)

    2014-06-01

    Purpose/Objectives: Radiation therapy (RT) is the principal modality in the treatment of patients with brain metastases (BM). However, given the activity of EGFR tyrosine kinase inhibitors in the central nervous system, it is uncertain whether upfront brain RT is necessary for patients with EGFR-mutant lung adenocarcinoma with BM. Methods and Materials: Patients with EGFR-mutant lung adenocarcinoma and newly diagnosed BM were identified. Results: 222 patients were identified. Exclusion criteria included prior erlotinib use, presence of a de novo erlotinib resistance mutation, or incomplete data. Of the remaining 110 patients, 63 were treated with erlotinib, 32 with whole brain RT (WBRT), and 15 with stereotactic radiosurgery (SRS). The median overall survival (OS) for the whole cohort was 33 months. There was no significant difference in OS between the WBRT and erlotinib groups (median, 35 vs 26 months; P=.62), whereas patients treated with SRS had a longer OS than did those in the erlotinib group (median, 64 months; P=.004). The median time to intracranial progression was 17 months. There was a longer time to intracranial progression in patients who received WBRT than in those who received erlotinib upfront (median, 24 vs 16 months, P=.04). Patients in the erlotinib or SRS group were more likely to experience intracranial failure as a component of first failure, whereas WBRT patients were more likely to experience failure outside the brain (P=.004). Conclusions: The survival of patients with EGFR-mutant adenocarcinoma with BM is notably long, whether they receive upfront erlotinib or brain RT. We observed longer intracranial control with WBRT, even though the WBRT patients had a higher burden of intracranial disease. Despite the equivalent survival between the WBRT and erlotinib group, this study underscores the role of WBRT in producing durable intracranial control in comparison with a targeted biologic agent with known central nervous system activity.

  10. Synergic antiproliferative and antiangiogenic effects of EGFR and mTor inhibitors on pancreatic cancer cells.

    Science.gov (United States)

    Azzariti, Amalia; Porcelli, Letizia; Gatti, Giuliana; Nicolin, Angelo; Paradiso, Angelo

    2008-03-01

    The in vitro efficacy of both EGFR inhibitor gefitinib and mTor inhibitor rapamycin, either administrated alone or in different combination schedules, was analysed in four pancreas cancer cell lines. Both drugs were found to induce cell growth inhibition, apoptosis as well as a slight but stable accumulation of cells in the G0/G1 phase. In all cell lines, neither gefitinib nor rapamycin affected EGFR and the expression of its downstream effectors. By contrast, gefitinib inhibited in a fast and completely way p-EGFR and partially p-Akt while a 3 days-rapamycin exposure resulted in the inhibition of the expression of both mTor and p70S6K. Moreover, after early stimulation, the mTor inhibitor produced a progressive, and almost complete inhibition of p-Akt. The analysis of combined gefitinib and rapamycin administration showed a clear schedule-dependent activity which turned out to be synergic only when gefitinib was given before rapamycin. This synergism seemed to depend on increase of both p-Akt and p70S6K inhibition, the greater the induction of apoptosis, the higher the decrease in cell cycle rate. Moreover, the antiangiogenic activity of the two drugs given in combination was demonstrated by a strong reduction of VEGF release which turned out to be more pronounced in the synergic schedule, and HIF-1alpha inhibition-independent. Our results suggest that the schedule of gefitinib followed by rapamycin, acting at different levels of the EGFR cellular pathway, could induce antitumor and antiangiogenic effects of clinical interest in the pancreas cancer model.

  11. Design of an EGFR-targeting toxin for photochemical delivery: in vitro and in vivo selectivity and efficacy.

    Science.gov (United States)

    Berstad, M B; Cheung, L H; Berg, K; Peng, Q; Fremstedal, A S V; Patzke, S; Rosenblum, M G; Weyergang, A

    2015-10-29

    The number of epidermal growth factor receptor (EGFR)-targeting drugs in the development for cancer treatment is continuously increasing. Currently used EGFR-targeted monoclonal antibodies and tyrosine kinase inhibitors have specific limitations related to toxicity and development of resistance, and there is a need for alternative treatment strategies to maximize the clinical potential of EGFR as a molecular target. This study describes the design and production of a novel EGFR-targeted fusion protein, rGel/EGF, composed of the recombinant plant toxin gelonin and EGF. rGel/EGF was custom-made for administration by photochemical internalization (PCI), a clinically tested modality for cytosolic release of macromolecular therapeutics. rGel/EGF lacks efficient mechanisms for endosomal escape and is therefore minimally toxic as monotherapy. However, PCI induces selective and efficient cytosolic release of rGel/EGF in EGFR-expressing target cells by light-directed activation of photosensitizers accumulated selectively in tumor tissue. PCI of rGel/EGF was shown to be highly effective against EGFR-expressing cell lines, including head and neck squamous cell carcinoma (HNSCC) cell lines resistant to cetuximab (Erbitux). Apoptosis, necrosis and autophagy were identified as mechanisms of action following PCI of rGel/EGF in vitro. PCI of rGel/EGF was further shown as a highly tumor-specific and potent modality in vivo, with growth inhibitory effects demonstrated on A-431 squamous cell carcinoma (SCC) xenografts and reduction of tumor perfusion and necrosis induction in SCC-026 HNSCC tumors. Considering the small amount of rGel/EGF injected per animal (0.1 mg/kg), the presented in vivo results are highly promising and warrant optimization and production of rGel/EGF for further preclinical evaluation with PCI.

  12. Kidney function, endothelial activation and atherosclerosis in black and white Africans with rheumatoid arthritis.

    Directory of Open Access Journals (Sweden)

    Patrick H Dessein

    Full Text Available To determine whether kidney function independently relates to endothelial activation and ultrasound determined carotid atherosclerosis in black and white Africans with rheumatoid arthritis (RA.We calculated the Jelliffe, 5 Cockcroft-Gault equations, Salazar-Corcoran, Modification of Diet in Renal Disease (MDRD and Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI estimated glomerular filtration rate (EGFR equations in 233 (112 black RA patients.The CKD-EPI eGFR was 0.1 for comparisons of AUC (SE for the other 8 equations. Based on optimal eGFR cutoff values with sensitivities and specificities ranging from 42 to 60% and 70 to 91% respectively, as determined in ROC curve analysis, a low eGFR increased the odds ratio for plaque 2.2 to 4.0 fold.Reduced kidney function is independently associated with atherosclerosis and endothelial activation in black and white Africans with RA, respectively. CKD is highly prevalent in black Africans with RA. Apart from the MDRD, eGFR equations are useful in predicting carotid plaque presence, a coronary heart disease equivalent, amongst black African RA patients.

  13. Antitumor and antiangiogenic effect of the dual EGFR and HER-2 tyrosine kinase inhibitor lapatinib in a lung cancer model

    Directory of Open Access Journals (Sweden)

    Collantes Maria

    2010-05-01

    Full Text Available Abstract Background There is strong evidence demonstrating that activation of epidermal growth factor receptors (EGFRs leads to tumor growth, progression, invasion and metastasis. Erlotinib and gefitinib, two EGFR-targeted agents, have been shown to be relevant drugs for lung cancer treatment. Recent studies demonstrate that lapatinib, a dual tyrosine kinase inhibitor of EGFR and HER-2 receptors, is clinically effective against HER-2-overexpressing metastatic breast cancer. In this report, we investigated the activity of lapatinib against non-small cell lung cancer (NSCLC. Methods We selected the lung cancer cell line A549, which harbors genomic amplification of EGFR and HER-2. Proliferation, cell cycle analysis, clonogenic assays, and signaling cascade analyses (by western blot were performed in vitro. In vivo experiments with A549 cells xenotransplanted into nude mice treated with lapatinib (with or without radiotherapy were also carried out. Results Lapatinib dramatically reduced cell proliferation (P P P in vitro. Furthermore, lapatinib induced G1 cell cycle arrest (P P In vivo experiments revealed that A549 tumor-bearing mice treated with lapatinib had significantly less active tumors (as assessed by PET analysis (P P Conclusion Overall, these data suggest that lapatinib may be a clinically useful agent for the treatment of lung cancer.

  14. Determination of ultraviolet filter activity on coconut oil cosmetic cream

    Science.gov (United States)

    Widiyati, Eni

    2017-08-01

    A research on determination of ultraviolet (UV) filter activity of cosmetic cream with coconut oil as raw material has been done. The cream was made by mixing the oil phase (coconut oil, stearic acid, lanolin and cetyl alcohol) at 70°C and the water phase (glycerin, aquadest and triethanolamine) at 70°C, while stirring until reached a temperature of 35°C. It was made also a cream with inorganic sunscreen TiO2 and organic sunscreen benzophenone-3 as a comparison. To study the UV filter activity, each cream was determined the UV absorption using UV spectrophotometer. The results show that cosmetic cream with coconut oil as raw material absorbs UV rays in the region of UV-C, whereas the cream with TiO2 absorbs the UV rays from UV-C to UV-A and cream with benzophenone-3 absorbs the UV rays from UV-B to UV-A region. This means that, the cosmetic cream with coconut oil as raw material has an activity as UV-C filter. If this cream is expected to have an activity as a sunscreen, it must be added an inorganic or organic sunscreen or a mixture of both as an active materials.

  15. EGFR Amplification and IDH Mutations in Glioblastoma Patients of the Northeast of Morocco

    Directory of Open Access Journals (Sweden)

    Nadia Senhaji

    2017-01-01

    Full Text Available Glioblastomas are the most frequent and aggressive primary brain tumors which are expressing various evolutions, aggressiveness, and prognosis. Thus, the 2007 World Health Organization classification based solely on the histological criteria is no longer sufficient. It should be complemented by molecular analysis for a true histomolecular classification. The new 2016 WHO classification of tumors of the central nervous system uses molecular parameters in addition to histology to reclassify these tumors and reduce the interobserver variability. The aim of this study is to determine the prevalence of IDH mutations and EGFR amplifications in the population of the northeast region of Morocco and then to compare the results with other studies. Methods. IDH1 codon 132 and IDH2 codon 172 were directly sequenced and the amplification of exon 20 of EGFR gene was investigated by qPCR in 65 glioblastoma tumors diagnosed at the University Hospital of Fez between 2010 and 2014. Results. The R132H IDH1 mutation was observed in 8 of 65 tumor samples (12.31%. No mutation of IDH2 was detected. EGFR amplification was identified in 17 cases (26.15%. Conclusion. A systematic search of both histological and molecular markers should be requisite for a good diagnosis and a better management of glioblastomas.

  16. EGFR Amplification and IDH Mutations in Glioblastoma Patients of the Northeast of Morocco

    Science.gov (United States)

    Louati, Sara; Chbani, Laila; El Fatemi, Hind; Hammas, Nawal; Mikou, Karima; Maaroufi, Mustapha; Benzagmout, Mohammed; Boujraf, Said; El Bardai, Sanae; Giry, Marine; Marie, Yannick; Chaoui El Faiz, Mohammed; Mokhtari, Karima; Amarti, Afaf; Bennis, Sanae

    2017-01-01

    Glioblastomas are the most frequent and aggressive primary brain tumors which are expressing various evolutions, aggressiveness, and prognosis. Thus, the 2007 World Health Organization classification based solely on the histological criteria is no longer sufficient. It should be complemented by molecular analysis for a true histomolecular classification. The new 2016 WHO classification of tumors of the central nervous system uses molecular parameters in addition to histology to reclassify these tumors and reduce the interobserver variability. The aim of this study is to determine the prevalence of IDH mutations and EGFR amplifications in the population of the northeast region of Morocco and then to compare the results with other studies. Methods. IDH1 codon 132 and IDH2 codon 172 were directly sequenced and the amplification of exon 20 of EGFR gene was investigated by qPCR in 65 glioblastoma tumors diagnosed at the University Hospital of Fez between 2010 and 2014. Results. The R132H IDH1 mutation was observed in 8 of 65 tumor samples (12.31%). No mutation of IDH2 was detected. EGFR amplification was identified in 17 cases (26.15%). Conclusion. A systematic search of both histological and molecular markers should be requisite for a good diagnosis and a better management of glioblastomas. PMID:28785587

  17. Determinants of Demand for Physical Activity among Students in Krakow

    Directory of Open Access Journals (Sweden)

    Kościółek Szczepan

    2017-06-01

    Full Text Available The low level of physical activity amongst Poles is not only a social problem, but also a big challenge for commercial organizations. The aim of the thesis was to determine indicating factors influencing the maximum price that students are prone to pay for physical activity. The research was based on the opinions of 398 respondents (students from Krakow’s academies. A Chi-square test of independence was used to compare the distribution of the observed variables with their theoretical distribution.

  18. Tumor Targeting Using Anti–Epidermal Growth Factor Receptor (ior egf/r3 Immunoconjugate with a Tetraaza Macrocyclic Agent (DO3A-EA

    Directory of Open Access Journals (Sweden)

    Gauri Mishra

    2012-09-01

    Full Text Available Epidermal growth factor receptor (EGFR signaling inhibition represents a highly promising arena for the application of molecularly targeted cancer therapies. EGFR conjugated metal chelates have been proposed as potential imaging agents for cancers that overexpress EGFR receptors. Through improved understanding of EGFR biology in human cancers, there is anticipation that more tumor-selective therapy approaches with diminished collateral normal tissue toxicity can be advanced. We report here on the results with a thermodynamically stable chelate, 1,4,7-tris(carboxymethyl-10-(2-aminoethyl-1,4,7,10-tetraazacyclododecane (DO3A-EA and anti-EGFr (ior egf/r3 conjugate to develop immunospecifc imaging agent. Conjugation and labelling with anti-EGFr was performed using standard procedure and subjected to purification on size exclusion chromatography. The conjugated antibodies were labeled with a specific activity 20-30 mCi/mg of protein. Labeling efficiencies were measured by ascending paper chromatography on ITLC-SG strips. Radiolabeling of the immunoconjugate was found to be 98.5 ± 0.30%. 99mTc-DO3A-EA-EGFr conjugate was studied in athymic mice bearing U-87MG, MDA-MB-468 tumors following intravenous injection. Pharmacokinetic and biodistribution studies confirmed long circulation times (t1/2(fast= 45 min and t1/2(slow=4 hours 40 min and efficient accumulation in tumors. Biodistribution studies in athymic mice grafted with U-87MG human glioblastoma multiforme and Hela human cervical carcinoma tumors revealed significant localization of 99mTc-labeled antibodies conjugate in tumors and reduced accumulation in normal organs. This new chelating agent is promising for immunoscintigraphy since good tumour-to-normal organ contrast could be demonstrated. These properties can be exploited for immunospecifc contrast agents in nuclear medicine and SPECT imaging.

  19. Altered Treg and IL-1A Expression in the Immune Microenvironment 
of Lung Squamous-cell Cancer after EGFR Blockade

    Directory of Open Access Journals (Sweden)

    Haiyang HE

    2017-03-01

    Full Text Available Background and objective Targeting the mutations and amplifications in the epidermal growth factor receptor (EGFR gene has curative effects on cancers of the lung, oral cavity, and gastrointestinal system. However, a systemic immune inflammation is an adverse effect of this therapeutic strategy. In this study, we aimed to identify the possible changes in the tumor microenvironment that contribute to the anti-cancer activity of EGFR inhibition. Methods Squamous-cell cancers were induced by the syngeneic transplantation of either EGFR-null or wild-type mouse primary keratinocytes that had been transduced with an oncogenic H-ras retrovirus. The mice were treated with gefinitib. Then, flow cytometric was used to detect the ratio of T cells and the expression of programmed cell death receptor 1 (PD-1. RT-PCR was used to detect the expression of cytokines and chemokines. Results Tumors that formed from EGFR-null keratinocytes were smaller, had fewer infiltrating FoxP3+ Treg cells, lower Foxp3 RNA, and lower percentage of PD-1 positive CD4 cells than those formed from wild-type keratinocytes. These results indicated that tumor cells can autonomously regulate the tumor microenvironment. Hosts with wild-type cancers and that were treated with gefitinib for 1 week tended to have smaller tumors. The treated mice in the short-term pharmacological model tended to have reduced FoxP3+ cells and FoxP3 RNA in the tumor microenvironment, as well as a substantially increased ratio of IL-1A/IL-1RA transcripts. These results suggested that the brief systemic inhibition of EGFR signaling alters the immune environment of the targeted cancer. Conclusion The autonomous (genetic or systemic (pharmacologic inhibition of EGFR signaling in tumor cells reduces tumor growth and Treg infiltration in the tumor microenvironment. An EGFR-dependent Treg function supports the growth of squamous cancers. Therefore, Treg is a target in the therapeutic strategy of EGFR inhibition.

  20. Establishing Dual Resistance to EGFR-TKI and MET-TKI in Lung Adenocarcinoma Cells In Vitro with a 2-step Dose-escalation Procedure.

    Science.gov (United States)

    Yamaoka, Toshimitsu; Ohba, Motoi; Arata, Satoru; Ohmori, Tohru

    2017-08-11

    Drug resistance is a major challenge in cancer therapy. The generation of resistant sublines in vitro is necessary for discovering novel mechanisms to overcome this challenge. Here, a 2-step dose-escalation method for establishing dual-resistance to an epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitor (TKI), gefitinib, and a MET-TKI, PHA665752, is described. This method is based on simple stepwise dose-escalation of inhibitors for inducing acquired resistance in cell lines. The alternate method for generating resistant sublines involves exposing the cells to high concentrations of the inhibitor in one step. The stepwise dose-escalation method has a higher possibility of successfully inducing acquired resistance than this method. Activating EGFR mutations are biomarkers of a response to treatment with EGFR-TKI, which is an applied first-line treatment for non-small cell lung cancers (NSCLC) that harbor these mutations. However, despite reports of effective responses, the use of EGFR-TKI is limited because tumors inevitably acquire resistance. The major mechanisms behind EGFR-TKI resistance include a secondary mutation at the gatekeeper site, T790M in exon 20 of EGFR, and a bypass signal of MET. Thus, a potential solution for this issue would be a combination of EGFR-TKI and MET-TKI. This combined treatment has been shown to be effective in an in vitro study model. Acquired gefitinib-resistance was established through MET-amplification by stepwise dose-escalation of gefitinib for 12 months, and a cell line named PC-9MET1000 was generated in a previous study. To further investigate the mechanisms of acquired MET-TKI and EGFR-TKI resistance, a MET-TKI, PHA665752, was administered to these cells with stepwise dose-escalation in the presence of gefitinib for 12 months. This protocol has also been successfully applied for a number of combination therapies to establish acquired resistance to other inhibitor molecules.

  1. EGFR tyrosine kinase inhibitory peptide attenuates Helicobacter pylori-mediated hyper-proliferation in AGS enteric epithelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Himaya, S.W.A. [Marine Bio-Process Research Center, Pukyong National University, Nam-Gu, Busan, 608-737 (Korea, Republic of); Dewapriya, Pradeep [Department of Chemistry, Pukyong National University, Nam-Gu, Busan, 608-737 (Korea, Republic of); Kim, Se-Kwon, E-mail: sknkim@pknu.ac.kr [Marine Bio-Process Research Center, Pukyong National University, Nam-Gu, Busan, 608-737 (Korea, Republic of); Department of Chemistry, Pukyong National University, Nam-Gu, Busan, 608-737 (Korea, Republic of)

    2013-06-15

    Helicobacter pylori infection is one of the most critical causes of stomach cancer. The current study was conducted to explore the protective effects of an isolated active peptide H-P-6 (Pro-Gln-Pro-Lys-Val-Leu-Asp-Ser) from microbial hydrolysates of Chlamydomonas sp. against H. pylori-induced carcinogenesis. The peptide H-P-6 has effectively suppressed H. pylori-induced hyper-proliferation and migration of gastric epithelial cells (AGS). However, the peptide did not inhibit the viability of the bacteria or invasion into AGS cells. Therefore, the effect of the peptide on regulating H. pylori-induced molecular signaling was investigated. The results indicated that H. pylori activates the EGFR tyrosine kinase signaling and nuclear translocation of the β-catenin. The EGFR activation has led to the up-regulation of PI3K/Akt signaling pathway. Moreover, the nuclear translocation levels of β-catenin were significantly increased as a result of Akt mediated down-regulation of GSK3/β protein levels in the cytoplasm. Both of these consequences have resulted in increased expression of cell survival and migration related genes such as c-Myc, cyclin-D, MMP-2 and matrilysin. Interestingly, the isolated peptide potently inhibited H. pylori-mediated EGFR activation and thereby down-regulated the subsequent P13K/Akt signaling leading to β-catenin nuclear translocation. The effect of the peptide was confirmed with the use of EGFR tyrosine kinase inhibitor AG1487 and molecular docking studies. Collectively this study identifies a potent peptide which regulates the H. pylori-induced hyper-proliferation and migration of AGS cells at molecular level. - Highlights: • Chlamydomonas sp. derived peptide H-P-6 inhibits H. pylori-induced pathogenesis. • H-P-6 suppresses H. pylori-induced hyper-proliferation and migration of AGS cells. • The peptide inhibits H. pylori-induced EGFR activation.

  2. Factors affecting eGFR 5-year post-deceased donor renal transplant: analysis and predictive model.

    Science.gov (United States)

    Elbadri, Abdalla; Traynor, Carol; Veitch, John T; O'Kelly, Patrick; Magee, Colm; Denton, Mark; O'Sheaghdha, Conall; Conlon, Peter J

    2015-04-01

    Long-term survival of renal allografts has improved over the last 20 years. However, less is known about current expectations for long-term allograft function as determined by estimated glomerular filtration rate (eGFR). The aim of this study was to investigate factors which affect graft function at 5 years' post-renal transplantation. The statistically significant factors were then used to construct a predictive model for expected eGFR at five years' post-transplant. We retrospectively reviewed all adult patients who received a renal transplant in the Republic of Ireland between 1990 and 2004. Data collected included era of transplantation (1990-1994, 1995-1999, 2000-2004), donor and recipient age and gender, number of human leucocyte antigen mismatches, cold ischemia time (CIT), number of prior renal transplants, immunosuppressive regimen used and acute rejection episodes. Estimated GFR was calculated at 5 years after transplantation from patient data using the Modified Diet in Renal Disease (MDRD) equation. Consecutive sampling was used to divide the study population into two equal unbiased groups of 489 patients. The first group (derivation cohort) was used to construct a predictive model for eGFR five years' post-transplantation, the second (validation cohort) to test this model. Nine hundred and seventy eight patients were analyzed. The median age at transplantation was 43 years (range 18-78) and 620 (63.4%) were male. One hundred and seventy five patients (17.9%) had received a prior renal transplant. Improved eGFR at five years' post-transplantation was associated with tacrolimus-based combination immunosuppression, younger donor age, male recipient, absence of cytomegalovirus disease and absence of acute rejection episodes as independently significant factors (p predictive model developed using these factors showed good correlation between predicted and actual median eGFR at five years. The model explained 20% of eGFR variability. The validation model

  3. Adenocarcinoma of the lung with EGFR gene mutation and subsequent resistance mechanisms exploration: case report

    Directory of Open Access Journals (Sweden)

    Xu L

    2017-09-01

    Full Text Available Li Xu,1,2 Qian Z Wang,1,2 Lin Wu1,2 1Department of the Second Chest Medicine, Hunan Cancer Hospital, Changsha, Hunan, People’s Republic of China; 2Department of the Second Chest Medicine, The Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, Hunan, People’s Republic of China Abstract: The treatment of lung cancer has made paradigm-shift advancements in the past decade with the development of therapies directed at specific genetic alterations, such as epidermal growth factor receptor (EGFR. Here, we present a rare case of lung adenocarcinoma harboring EGFR activating mutation and ALK overexpression. During the EGFR-tyrosine kinase inhibitors treatment, next-generation sequencing revealed phosphatidylinositol 3-kinase/Akt/mammalian target of rapamycin pathway amplifications in tumor specimen and subsequent T790M mutation via plasma circulating tumor DNA. In conclusion, this case illustrates the existence of concomitant resistance mechanisms and demonstrates that circulating tumor DNA can reflect tumor heterogeneity. Keywords: epidermal growth factor receptor, PI3K/Akt/mTOR pathway, T790M, next-generation sequencing, circulating tumor DNA

  4. NF2/Merlin mediates contact-dependent inhibition of EGFR mobility and internalization via cortical actomyosin.

    Science.gov (United States)

    Chiasson-MacKenzie, Christine; Morris, Zachary S; Baca, Quentin; Morris, Brett; Coker, Joanna K; Mirchev, Rossen; Jensen, Anne E; Carey, Thomas; Stott, Shannon L; Golan, David E; McClatchey, Andrea I

    2015-10-26

    The proliferation of normal cells is inhibited at confluence, but the molecular basis of this phenomenon, known as contact-dependent inhibition of proliferation, is unclear. We previously identified the neurofibromatosis type 2 (NF2) tumor suppressor Merlin as a critical mediator of contact-dependent inhibition of proliferation and specifically found that Merlin inhibits the internalization of, and signaling from, the epidermal growth factor receptor (EGFR) in response to cell contact. Merlin is closely related to the membrane-cytoskeleton linking proteins Ezrin, Radixin, and Moesin, and localization of Merlin to the cortical cytoskeleton is required for contact-dependent regulation of EGFR. We show that Merlin and Ezrin are essential components of a mechanism whereby mechanical forces associated with the establishment of cell-cell junctions are transduced across the cell cortex via the cortical actomyosin cytoskeleton to control the lateral mobility and activity of EGFR, providing novel insight into how cells inhibit mitogenic signaling in response to cell contact. © 2015 Chiassson-MacKenzie et al.

  5. Facile and efficient synthesis and biological evaluation of 4-anilinoquinazoline derivatives as EGFR inhibitors.

    Science.gov (United States)

    Wang, Zheng; Wu, Xue; Wang, Li; Zhang, Jiao; Liu, Jianli; Song, Zhongxing; Tang, Zhishu

    2016-06-01

    Series of 4-anilinoquinazoline derivatives were conveniently and efficiently synthesized and their antitumor activities were evaluated by MTT assay in three human cancer cell lines: H1975, HepG2 and SMMC-7721. New compounds 19a-19h were designed and synthesized to seek for powerful EGFR inhibitors and to explore whether methyl group at C-2 position of quinazoline ring has a positive effect on EGFR inhibition. All the compounds of 19a-19h were found potent against all three cell lines and five compounds (19c, 19d, and 19f-19h) were found more potent against H1975 than gefitinib. SAR studies revealed that methyl group at C-2 position of quinazoline ring could significantly improve the antitumor potency of 4-anilinoquinazolines. The same conclusion was also drawn according to the results of Western blotting analysis. Among all the tested compounds, 19g exhibited extremely potent against H1975 with an IC50 value of 0.11μM, remarkably lower than that of gefitinib (1.23μM). The results of western blotting analysis showed that compounds 19c and 19g could notably inhibit the expression of phosphorylated EGFR, especially 19g, almost inhibited completely. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Cisplatin-alginate conjugate liposomes for targeted delivery to EGFR-positive ovarian cancer cells.

    Science.gov (United States)

    Wang, Yunfei; Zhou, Jinhua; Qiu, Lihua; Wang, Xinran; Chen, Lilan; Liu, Ting; Di, Wen

    2014-05-01

    Systemic side effects and low aqueous solubility have limited the clinical use of cisplatin (CDDP) in ovarian carcinoma and have contributed to failures in developing effective drug delivery systems. In order to develop a novel drug delivery system with enhanced efficacy and minimal adverse effects, we exploited the properties of sodium alginate (SA) to synthesize CDDP-SA conjugate (CS), which is highly soluble and readily incorporated into liposomes (CS-PEG-Lip). Epidermal growth factor receptor (EGFR) is overexpressed in many ovarian cancers, therefore we modified EGF on the liposomes (CS-EGF-Lip) to specifically target EGFR-expressing tumors, thereby increasing the bioavailability and efficacy of CDDP. In vitro experiments confirmed that EGF-Lip selectively recognized EGFR-positive SKOV3 cells and effectively penetrated tumor spheroids. We demonstrated that CS-EGF-Lip possessed satisfactory size distribution and exhibited significantly improved encapsulation and loading efficiency. Furthermore, CS-EGF-Lip sustained release of CDDP in vitro, suggesting that CS-EGF-Lip may retain the antitumor activity of CDDP. Inhibition of proliferation and migration was also greater with CS-EGF-Lip compared to CDDP. In vivo xenograft experiments revealed that administration of CS-EGF-Lip enhanced delivery of CDDP into ovarian tumor tissues and improved the antitumor efficacy of CDDP, while reducing nephrotoxicity and body weight loss in mice. These results suggest that CS-EGF-Lip may offer a promising strategy for CDDP delivery in the treatment of EGFR-positive ovarian carcinoma or similar tumors, with enhanced efficacy and fewer adverse effects. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. Dynamic Bayesian Network Modeling of the Interplay between EGFR and Hedgehog Signaling.

    Directory of Open Access Journals (Sweden)

    Holger Fröhlich

    Full Text Available Aberrant activation of sonic Hegdehog (SHH signaling has been found to disrupt cellular differentiation in many human cancers and to increase proliferation. The SHH pathway is known to cross-talk with EGFR dependent signaling. Recent studies experimentally addressed this interplay in Daoy cells, which are presumable a model system for medulloblastoma, a highly malignant brain tumor that predominately occurs in children. Currently ongoing are several clinical trials for different solid cancers, which are designed to validate the clinical benefits of targeting the SHH in combination with other pathways. This has motivated us to investigate interactions between EGFR and SHH dependent signaling in greater depth. To our knowledge, there is no mathematical model describing the interplay between EGFR and SHH dependent signaling in medulloblastoma so far. Here we come up with a fully probabilistic approach using Dynamic Bayesian Networks (DBNs. To build our model, we made use of literature based knowledge describing SHH and EGFR signaling and integrated gene expression (Illumina and cellular location dependent time series protein expression data (Reverse Phase Protein Arrays. We validated our model by sub-sampling training data and making Bayesian predictions on the left out test data. Our predictions focusing on key transcription factors and p70S6K, showed a high level of concordance with experimental data. Furthermore, the stability of our model was tested by a parametric bootstrap approach. Stable network features were in agreement with published data. Altogether we believe that our model improved our understanding of the interplay between two highly oncogenic signaling pathways in Daoy cells. This may open new perspectives for the future therapy of Hedghog/EGF-dependent solid tumors.

  8. Impaired SHP2-Mediated Extracellular Signal-Regulated Kinase Activation Contributes to Gefitinib Sensitivity of Lung Cancer Cells with Epidermal Factor Receptor-Activating Mutations

    OpenAIRE

    Lazzara, Matthew J.; Lane, Keara M.; Chan, Richard; Jasper, Paul J; Yaffe, Michael B.; Sorger, Peter K.; Jacks, Tyler E.; Neel, Benjamin G.; Lauffenburger, Douglas A.

    2010-01-01

    Most non–small cell lung cancers (NSCLC) display elevated expression of epidermal growth factor receptor (EGFR), but response to EGFR kinase inhibitors is predominantly limited to NSCLC harboring EGFR-activating mutations. These mutations are associated with increased activity of survival pathways, including phosphatidylinositol 3-kinase/AKT and signal transducer and activator of transcription 3/5. We report that EGFR-activating mutations also surprisingly lead to decreased ability to activat...

  9. EGFR/ARF6 regulation of Hh signalling stimulates oncogenic Ras tumour overgrowth.

    Science.gov (United States)

    Chabu, Chiswili; Li, Da-Ming; Xu, Tian

    2017-03-10

    Multiple signalling events interact in cancer cells. Oncogenic Ras cooperates with Egfr, which cannot be explained by the canonical signalling paradigm. In turn, Egfr cooperates with Hedgehog signalling. How oncogenic Ras elicits and integrates Egfr and Hedgehog signals to drive overgrowth remains unclear. Using a Drosophila tumour model, we show that Egfr cooperates with oncogenic Ras via Arf6, which functions as a novel regulator of Hh signalling. Oncogenic Ras induces the expression of Egfr ligands. Egfr then signals through Arf6, which regulates Hh transport to promote Hh signalling. Blocking any step of this signalling cascade inhibits Hh signalling and correspondingly suppresses the growth of both, fly and human cancer cells harbouring oncogenic Ras mutations. These findings highlight a non-canonical Egfr signalling mechanism, centered on Arf6 as a novel regulator of Hh signalling. This explains both, the puzzling requirement of Egfr in oncogenic Ras-mediated overgrowth and the cooperation between Egfr and Hedgehog.

  10. Grape seed proanthocyanidins inhibit the invasive potential of head and neck cutaneous squamous cell carcinoma cells by targeting EGFR expression and epithelial-to-mesenchymal transition

    Directory of Open Access Journals (Sweden)

    Sun Qian

    2011-12-01

    Full Text Available Abstract Background Head and neck squamous cell carcinoma (HNSCC is responsible for over 20,000 deaths every year in United States. Most of the deaths are due, in large part, to its propensity to metastasize. We have examined the effect of bioactive component grape seed proanthocyanidins (GSPs on human cutaneous HNSCC cell invasion and the molecular mechanisms underlying these effects using SCC13 cell line as an in vitro model. Methods The therapeutic effects of GSPs on cancer cell invasion were studied using Boyden chamber and wound healing assays. The effects of GSPs on the levels of various proteins related with cancer cell invasion were determined using western blot analysis. Results Using in vitro cell invasion assays, we observed that treatment of SCC13 cells with GSPs resulted in a concentration-dependent inhibition of cell invasion of these cells, which was associated with a reduction in the levels of epidermal growth factor receptor (EGFR. Treatment of cells with gefitinib and erlotinib, inhibitors of EGFR, or transient transfection of SCC13 cells with EGFR small interfering RNA, also inhibited invasion of these cells. The inhibition of cell invasion by GSPs was associated with the inhibition of the phosphorylation of ERK1/2, a member of mitogen-activated protein kinase family. Treatment of cells with UO126, an inhibitor of MEK, also inhibited the invasion potential of SCC13 cells. Additionally, inhibition of human cutaneous HNSCC cell invasion by GSPs was associated with reversal of epithelial-to-mesenchymal transition (EMT process, which resulted in an increase in the levels of epithelial biomarker (E-cadherin while loss of mesenchymal biomarkers (vimentin, fibronectin and N-cadherin in cells. Similar effect on EMT biomarkers was also observed when cells were treated with erlotinib. Conclusion The results obtained from this study indicate that grape seed proanthocyanidins have the ability to inhibit the invasion of human cutaneous

  11. DETERMINATION OF ANTIMICROBIAL ACTIVITY OF EXTRACTS OF CALENDULA OFFICINALIS FLOWERS

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    P. V. Afanasyeva

    2016-01-01

    Full Text Available Pot marigold (Calendula officinalis L. is one of the most popular medicinal plants in the Russian Federation and abroad. The wide range of pharmacological activity of this medicinal plant is determined by carotenoids, flavonoids, saponins. These biologically active substances give total therapeutic effect of flowers of Calendula officinalis and medicines on base of pot marigold. This paper discusses the results of comparative investigations for a determination of antimicrobial activity of aqueous and aqueous- alcoholic extracts from pot marigold flowers. Detection of the minimum inhibitory concentration (MIC was carried out by using the method of double serial dilutions in broth. The following microorganisms were used as test cultures: Bacillus cereus, Candida albicans, Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus. The study showed that the widest spectrum of antibacterial activity has water extract of pot marigold flowers. As for Pseudomonas aeruginosa the most active medicine is tincture (1:10 with 70% alcohol. As for Escherichia coli the only phytopharmaceutical – water extract of marigold flowers, reveals antimicrobial activity. Against Bacillus cereus the most effective properties was indicated for tincture (1:5 with 70% ethanol and the liquid extract (1:2 with 70% alcohol. In case of Candida albicans, tincture (1:10 with 70% alcohol exhibited the highest activity.

  12. Mapping EGFR1 mutations in patients with lung adenocarcinoma.

    Science.gov (United States)

    Vlastos, Fotis; Zinszner, Julie; Hussenet, Thomas; du Manoir, Stanislas; Vordonis, Leonidas; Nikolakopoulou, Sofia; Hardavella, Georgia; Lacomme, Stéfanie; Vignaud, Jean Michel; Martinet, Nadine

    2010-12-01

    Unselected lung cancer patients seem unable to gain in terms of survival from treatment with epidermal growth factor receptor (EGFR) inhibitors. Screening for specific molecular targets involves detection of EGFR1 mutations. The aim of our study was to develop a simple set of tests to detect mutations at the tyrosine kinase domain of the EGFR1 gene while avoiding expensive DNA sequencing to select patients eligible for treatment. DNA samples from 85 adenocarcinoma patients were analyzed. The cohort consisted of 65 female (40 nonsmokers and 25 smokers) and 20 male patients [15 smokers and 5 diagnosed with bronchioloalveolar carcinomas (BAC)]. Different restriction enzymes were identified that recognize mutations at the EGFR1's tyrosine kinase domain. Biocomputing and polymerase chain reaction were used to develop molecular screening tools. Eight mutations were found in 7 patients, of which 5 were female nonsmokers (14.3%), 1 was a male nonsmoker, and 1 a male smoker. Among the mutations that were discovered, 5 (71%) were found at exon 19 and 3 (29%) at exon 20. At exon 19, 4 were deletions found in nonsmoker women, whereas the fifth was a deletion-insertion found in a nonsmoker male patient with BAC. At exon 20, 3 mutations were identified in 2 patients: a duplication (in a nonsmoker woman) and 2 substitutions (in a smoker male with BAC). No mutations were found at exons 18 and 21. Gene copy number was increased in 6 patients (4 female and 2 male) with the highest being found in a smoking female patient diagnosed with BAC. Mapping of EGFR1 mutations by alternative methods should be used in the screening of patients with non-small cell lung cancer who are candidates for EGFR inhibitor treatment. Patients with an increased EGFR1 copy number could benefit from the monoclonal antibody therapy.

  13. Development of method for the mineral water catalase activity determination

    OpenAIRE

    Olena М. Nikipelova; Аlena Yu. Kisilevskaya; Lyudmyla B. Solodova

    2015-01-01

    Biological effects of mineral water depend not only on the chemical composition but also on the metabolic products of microbial cenosis. Among numerous microorganisms constituting the autochthonous microflora of mineral waters, we do evolve the saprophytic organisms producing the catalase, the saprophytes’ physiological and biological role being proven a long ago. The research aim was to develop a method for determination of mineral water catalase activity. Analyzed are various methods to det...

  14. Structural Determinants of Clostridium difficile Toxin A Glucosyltransferase Activity

    Energy Technology Data Exchange (ETDEWEB)

    Pruitt, Rory N.; Chumbler, Nicole M.; Rutherford, Stacey A.; Farrow, Melissa A.; Friedman, David B.; Spiller, Ben; Lacy, D. Borden (Vanderbilt)

    2012-03-28

    The principle virulence factors in Clostridium difficile pathogenesis are TcdA and TcdB, homologous glucosyltransferases capable of inactivating small GTPases within the host cell. We present crystal structures of the TcdA glucosyltransferase domain in the presence and absence of the co-substrate UDP-glucose. Although the enzymatic core is similar to that of TcdB, the proposed GTPase-binding surface differs significantly. We show that TcdA is comparable with TcdB in its modification of Rho family substrates and that, unlike TcdB, TcdA is also capable of modifying Rap family GTPases both in vitro and in cells. The glucosyltransferase activities of both toxins are reduced in the context of the holotoxin but can be restored with autoproteolytic activation and glucosyltransferase domain release. These studies highlight the importance of cellular activation in determining the array of substrates available to the toxins once delivered into the cell.

  15. Sociodemographic determinants of pedometer-determined physical activity among Japanese adults.

    Science.gov (United States)

    Inoue, Shigeru; Ohya, Yumiko; Odagiri, Yuko; Takamiya, Tomoko; Suijo, Kenichi; Kamada, Masamitsu; Okada, Shinpei; Tudor-Locke, Catrine; Shimomitsu, Teruichi

    2011-05-01

    Although previous studies have reported physical activity and its sociodemographic determinants using self-report measures, there have been few studies using pedometers. To ascertain pedometer-determined physical activity and its sociodemographic determinants among community residents living in four Japanese cities. A cross-sectional mail survey was conducted from February 2007 to January 2008 with a sample of 4000 residents (aged 20-69 years and 50% male) who were randomly selected from the registry of residential addresses. Complete responses for both questionnaire and pedometer were obtained from 790 residents (48.3±13.7 years, 46.7% male). Associations of 11 sociodemographic variables with steps per day were examined using multiple logistic regression analyses. Data were analyzed in 2010. Men averaged 8763±3497 steps/day and women averaged 8242±3277 steps/day. Further, 29.0% of men and 27.8% of women walked ≥10,000 steps/day. City of residence, good self-rated health, low educational attainment, and not owning a car were associated with taking ≥10,000 steps/day in men, whereas employed status and dog ownership were associated with walking ≥10,000 steps/day in women. The results contribute to understanding of step-defined physical activity and its sociodemographic determinants. A diversity of step counts by sociodemographic variables clarifies specific populations among Japanese who are in need of intervention to promote physical activity. Copyright © 2011 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    Wei-Hua Li

    Full Text Available 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.

  17. Combined EGFR and VEGFR versus single EGFR signaling pathways inhibition therapy for NSCLC: a systematic review and meta-analysis.

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    Xinji Zhang

    Full Text Available BACKGROUND: Lung cancer is a heterogeneous disease with multiple signaling pathways influencing tumor cell survival and proliferation, and it is likely that blocking only one of these pathways allows others to act as salvage or escape mechanisms for cancer cells. Whether combined inhibition therapy has greater anti-tumor activity than single inhibition therapy is a matter of debate. Hence, a meta-analysis comparing therapy inhibiting both VEGFR and EGFR signaling pathways with that inhibiting EGFR signaling pathway alone was performed. METHODOLOGY AND PRINCIPAL FINDINGS: We searched PubMed, EMBASE database and the proceedings of major conferences for relevant clinical trials. Outcomes analyzed were objective tumor response rate (ORR, progression-free survival (PFS, overall survival (OS and toxicity. Besides, subgroup analyses were performed to investigate whether the combined inhibition therapy is best performed using combination of selective agents or a single agent with multiple targets. Six trials recruiting 3,302 patients were included in the analysis. Combined inhibition therapy was associated with a 3% improvement in OS as compared with single-targeted therapy, but this difference was not statistically significant (HR, 0.97; 95% CI, 0.89-1.05; P=0.472. Patients receiving combined inhibition therapy had significant longer PFS than the group with single-targeted therapy (HR, 0.80; 95% CI, 0.67-0.95; P=0.011. There was no difference in the ORR between the groups (OR, 1.44; 95% CI, 0.95-2.18; P=0.085. Subgroup analysis revealed that combined inhibition therapy using combination regimens was associated with statistically significant improvement in both ORR and PFS. Toxicity was greater in combined inhibition therapy. CONCLUSIONS: There is no evidence to support the use of combined inhibition therapy in unselected patients with advanced NSCLC. However, given the significant advantage in ORR and PFS, combined inhibition therapy using combination

  18. Determination ofEGFRandKRASmutational status in Greek non-small-cell lung cancer patients.

    Science.gov (United States)

    Papadopoulou, Eirini; Tsoulos, Nikolaos; Tsirigoti, Angeliki; Apessos, Angela; Agiannitopoulos, Konstantinos; Metaxa-Mariatou, Vasiliki; Zarogoulidis, Konstantinos; Zarogoulidis, Pavlos; Kasarakis, Dimitrios; Kakolyris, Stylianos; Dahabreh, Jubrail; Vlastos, Fotis; Zoublios, Charalampos; Rapti, Aggeliki; Papageorgiou, Niki Georgatou; Veldekis, Dimitrios; Gaga, Mina; Aravantinos, Gerasimos; Karavasilis, Vasileios; Karagiannidis, Napoleon; Nasioulas, George

    2015-10-01

    It has been reported that certain patients with non-small-cell lung cancer (NSCLC) that harbor activating somatic mutations within the tyrosine kinase domain of the epidermal growth factor receptor ( EGFR ) gene may be effectively treated using targeted therapy. The use of EGFR inhibitors in patient therapy has been demonstrated to improve response and survival rates; therefore, it was suggested that clinical screening for EGFR mutations should be performed for all patients. Numerous clinicopathological factors have been associated with EGFR and Kirsten-rat sarcoma oncogene homolog (KRAS) mutational status including gender, smoking history and histology. In addition, it was reported that EGFR mutation frequency in NSCLC patients was ethnicity-dependent, with an incidence rate of ~30% in Asian populations and ~15% in Caucasian populations. However, limited data has been reported on intra-ethnic differences throughout Europe. The present study aimed to investigate the frequency and spectrum of EGFR mutations in 1,472 Greek NSCLC patients. In addition, KRAS mutation analysis was performed in patients with known smoking history in order to determine the correlation of type and mutation frequency with smoking. High-resolution melting curve (HRM) analysis followed by Sanger sequencing was used to identify mutations in exons 18-21 of the EGFR gene and in exon 2 of the KRAS gene. A sensitive next-generation sequencing (NGS) technology was also employed to classify samples with equivocal results. The use of sensitive mutation detection techniques in a large study population of Greek NSCLC patients in routine diagnostic practice revealed an overall EGFR mutation frequency of 15.83%. This mutation frequency was comparable to that previously reported in other European populations. Of note, there was a 99.8% concordance between the HRM method and Sanger sequencing. NGS was found to be the most sensitive method. In addition, female non-smokers demonstrated a high prevalence of

  19. Differential effects of EGFR ligands on endocytic sorting of the receptor

    DEFF Research Database (Denmark)

    Roepstorff, Kirstine; Grandal, Michael Vibo; Henriksen, Lasse

    2009-01-01

    Endocytic downregulation is a pivotal mechanism turning off signalling from the EGF receptor (EGFR). It is well established that whereas EGF binding leads to lysosomal degradation of EGFR, transforming growth factor (TGF)-alpha causes receptor recycling. TGF-alpha therefore leads to continuous...... recycling. EGF leads to lysosomal degradation of the majority but not all EGFRs. Amphiregulin does not target EGFR for lysosomal degradation but causes fast as well as slow EGFR recycling. The Cbl ubiquitin ligases, especially c-Cbl, are responsible for EGFR ubiquitination after stimulation with all ligands...

  20. Determinants of active pulmonary tuberculosis in Ambo Hospital, West Ethiopia

    Directory of Open Access Journals (Sweden)

    Tenna Ephrem

    2015-02-01

    Full Text Available Objectives: The aim of this study was to determine factors associated with active pulmonary tuberculosis seen in cases in Ambo Hospital, Ethiopia.Design: A facility-based prospective case-control study.Setting: Patients attending Ambo Hospital from 01 December 2011 to 29 March 2012.Participants: The sample included 312 adult patients attending Ambo Hospital. The main outcome measure was presence of active pulmonary tuberculosis (TB.Explanatory measures: Age, gender, occupation, educational status, marital status, place of residence, patient history of TB, family history of TB, human immunodeficiency virus (HIV infection, smoking, alcohol intake, khat chewing, body mass index (BMI, employment, diabetes, history of asthma, previous history of worm infestation, history of hospitalisation, number of adults living in the household (HH, person per room, housing condition.Results: A total of 312 study participants, including 104 active pulmonary tuberculosis (PTB cases (cases and 208 non-active PTB cases (controls, were recruited for the present study. Having one or more family member with a history of TB (OR = 4.4; 95% CI: 1.50–12.90, marital status (OR = 7.6; 95% CI: 2.2–12.6, male gender (OR = 3.2; 95% CI: 1.4–7, rural residence (OR = 3.3; P = 0.012, being a current or past smoker (OR = 2.8; 95% CI: 1.1–7.2, BMI < 18.5 (OR = 2.1; 95% CI: 1.03–4.2, HIV infection (OR = 8.8; 95% CI: 2.4–23.8 and a history of worm infestation (OR = 6.4; 95% CI: 2.6–15.4 remained significant independent host-related factors for active PTB.Conclusion: Patients who came from a compound with more than two HHs were more likely to develop active PTB than those who came from a compound with only one HH. Those who lived in houses with no windows were more likely to develop active PTB than those who lived in houses with one or more windows, had a family history of TB, lived in rural areas. Sex of the patient was a predicting factor. Not being the owner of the house

  1. EGFR and HER2 signaling in breast cancer brain metastasis

    Science.gov (United States)

    Sirkisoon, Sherona R.; Carpenter, Richard L.; Rimkus, Tadas; Miller, Lance; Metheny-Barlow, Linda; Lo, Hui-Wen

    2016-01-01

    Breast cancer occurs in approximately 1 in 8 women and 1 in 37 women with breast cancer succumbed to the disease. Over the past decades, new diagnostic tools and treatments have substantially improved the prognosis of women with local diseases. However, women with metastatic disease still have a dismal prognosis without effective treatments. Among different molecular subtypes of breast cancer, the HER2-enriched and basal-like subtypes typically have higher rates of metastasis to the brain. Basal-like metastatic breast tumors frequently express EGFR. Consequently, HER2- and EGFR-targeted therapies are being used in the clinic and/or evaluated in clinical trials for treating breast cancer patients with brain metastases. In this review, we will first provide an overview of the HER2 and EGFR signaling pathways. The roles that EGFR and HER2 play in breast cancer metastasis to the brain will then be discussed. Finally, we will summarize the preclinical and clinical effects of EGFR- and HER2-targeted therapies on breast cancer metastasis. PMID:26709660

  2. Physical activity and determinants of physical activity in obese and non-obese children

    National Research Council Canada - National Science Library

    S G Trost; L M Kerr; D S Ward; R R Pate

    2001-01-01

      OBJECTIVE:: To compare the physical activity (PA) patterns and the hypothesized psychosocial and environmental determinants of PA in an ethnically diverse sample of obese and non-obese middle school children. DESIGN...

  3. Structural determinants of the eosinophil cationic protein antimicrobial activity.

    Science.gov (United States)

    Boix, Ester; Salazar, Vivian A; Torrent, Marc; Pulido, David; Nogués, M Victòria; Moussaoui, Mohammed

    2012-08-01

    Antimicrobial RNases are small cationic proteins belonging to the vertebrate RNase A superfamily and endowed with a wide range of antipathogen activities. Vertebrate RNases, while sharing the active site architecture, are found to display a variety of noncatalytical biological properties, providing an excellent example of multitask proteins. The antibacterial activity of distant related RNases suggested that the family evolved from an ancestral host-defence function. The review provides a structural insight into antimicrobial RNases, taking as a reference the human RNase 3, also named eosinophil cationic protein (ECP). A particular high binding affinity against bacterial wall structures mediates the protein action. In particular, the interaction with the lipopolysaccharides at the Gram-negative outer membrane correlates with the protein antimicrobial and specific cell agglutinating activity. Although a direct mechanical action at the bacteria wall seems to be sufficient to trigger bacterial death, a potential intracellular target cannot be discarded. Indeed, the cationic clusters at the protein surface may serve both to interact with nucleic acids and cell surface heterosaccharides. Sequence determinants for ECP activity were screened by prediction tools, proteolysis and peptide synthesis. Docking results are complementing the structural analysis to delineate the protein anchoring sites for anionic targets of biological significance.

  4. Determination of strongly overlapping signaling activity from microarray data

    Directory of Open Access Journals (Sweden)

    Bidaut Ghislain

    2006-02-01

    Full Text Available Abstract Background As numerous diseases involve errors in signal transduction, modern therapeutics often target proteins involved in cellular signaling. Interpretation of the activity of signaling pathways during disease development or therapeutic intervention would assist in drug development, design of therapy, and target identification. Microarrays provide a global measure of cellular response, however linking these responses to signaling pathways requires an analytic approach tuned to the underlying biology. An ongoing issue in pattern recognition in microarrays has been how to determine the number of patterns (or clusters to use for data interpretation, and this is a critical issue as measures of statistical significance in gene ontology or pathways rely on proper separation of genes into groups. Results Here we introduce a method relying on gene annotation coupled to decompositional analysis of global gene expression data that allows us to estimate specific activity on strongly coupled signaling pathways and, in some cases, activity of specific signaling proteins. We demonstrate the technique using the Rosetta yeast deletion mutant data set, decompositional analysis by Bayesian Decomposition, and annotation analysis using ClutrFree. We determined from measurements of gene persistence in patterns across multiple potential dimensionalities that 15 basis vectors provides the correct dimensionality for interpreting the data. Using gene ontology and data on gene regulation in the Saccharomyces Genome Database, we identified the transcriptional signatures of several cellular processes in yeast, including cell wall creation, ribosomal disruption, chemical blocking of protein synthesis, and, criticially, individual signatures of the strongly coupled mating and filamentation pathways. Conclusion This works demonstrates that microarray data can provide downstream indicators of pathway activity either through use of gene ontology or transcription

  5. Rapid optical determination of β-lactamase and antibiotic activity

    Science.gov (United States)

    2014-01-01

    Background The absence of rapid tests evaluating antibiotic susceptibility results in the empirical prescription of antibiotics. This can lead to treatment failures due to escalating antibiotic resistance, and also furthers the emergence of drug-resistant bacteria. This study reports a rapid optical method to detect β-lactamase and thereby assess activity of β-lactam antibiotics, which could provide an approach for targeted prescription of antibiotics. The methodology is centred on a fluorescence quenching based probe (β-LEAF – β-Lactamase Enzyme Activated Fluorophore) that mimics the structure of β-lactam antibiotics. Results The β-LEAF assay was performed for rapid determination of β-lactamase production and activity of β-lactam antibiotic (cefazolin) on a panel of Staphylococcus aureus ATCC strains and clinical isolates. Four of the clinical isolates were determined to be lactamase producers, with the capacity to inactivate cefazolin, out of the twenty-five isolates tested. These results were compared against gold standard methods, nitrocefin disk test for β-lactamase detection and disk diffusion for antibiotic susceptibility, showing results to be largely consistent. Furthermore, in the sub-set of β-lactamase producers, it was demonstrated and validated that multiple antibiotics (cefazolin, cefoxitin, cefepime) could be assessed simultaneously to predict the antibiotic that would be most active for a given bacterial isolate. Conclusions The study establishes the rapid β-LEAF assay for β-lactamase detection and prediction of antibiotic activity using S. aureus clinical isolates. Although the focus in the current study is β-lactamase-based resistance, the overall approach represents a broad diagnostic platform. In the long-term, these studies form the basis for the development of assays utilizing a broader variety of targets, pathogens and drugs. PMID:24708478

  6. Role of EGFR transactivation in angiotensin II signaling to extracellular regulated kinase in preglomerular smooth muscle cells.

    Science.gov (United States)

    Andresen, Bradley T; Linnoila, Jenny J; Jackson, Edwin K; Romero, Guillermo G

    2003-03-01

    Angiotensin (Ang) II promotes the phosphorylation of extracellular regulated kinase (ERK); however, the mechanisms leading to Ang II-induced ERK phosphorylation are debated. The currently accepted theory involves transactivation of epidermal growth factor receptor (EGFR). We have shown that generation of phosphatidic acid (PA) is required for the recruitment of Raf to membranes and the activation of ERK by multiple agonists, including Ang II. In the present report, we confirm that phospholipase D-dependent generation of PA is required for Ang II-mediated phosphorylation of ERK in Wistar-Kyoto and spontaneously hypertensive rat preglomerular smooth muscle cells (PGSMCs). However, EGF stimulation does not activate phospholipase D or generate PA. These observations indicate that EGF recruits Raf to membranes via a mechanism that does not involve PA, and thus, Ang II-mediated phosphorylation of ERK is partially independent of EGFR-mediated signaling cascades. We hypothesized that phosphoinositide-3-kinase (PI3K) can also act to recruit Raf to membranes; therefore, inhibition of PI3K should inhibit EGF signaling to ERK. Wortmannin, a PI3K inhibitor, inhibited EGF-mediated phosphorylation of ERK (IC50, approximately 14 nmol/L). To examine the role of the EGFR in Ang II-mediated phosphorylation of ERK we utilized 100 nmol/L wortmannin to inhibit EGFR signaling to ERK and T19N RhoA to block Ang II-mediated ERK phosphorylation. Wortmannin treatment inhibited EGF-mediated but not Ang II-mediated phosphorylation of ERK. Furthermore, T19N RhoA inhibited Ang II-mediated ERK phosphorylation, whereas T19N RhoA had significantly less effect on EGF-mediated ERK phosphorylation. We conclude that transactivation of the EGFR is not primarily responsible for Ang II-mediated activation of ERK in PGSMCs.

  7. Co-expression of periostin and EGFR in patients with esophageal squamous cell carcinoma and their prognostic significance

    Directory of Open Access Journals (Sweden)

    Jia W

    2016-08-01

    Full Text Available Wei Jia,1 Wei Wang,1 Chu-shu Ji,1 Jun-yang Niu,2 Ya-jing Lv,1 Hang-cheng Zhou,2 Bing Hu1 1Department of Medical Oncology, 2Department of Pathology, Anhui Provincial Hospital, Anhui Medical University, Hefei, People’s Republic of China Background: Both periostin (PN and epidermal growth factor receptor (EGFR can predict the prognosis of several carcinomas alone. However, coexpression of PN and EGFR in esophageal squamous cell carcinoma (ESCC still remains unknown. We aimed to clarify their relationship with clinicopathological factors and prognostic significance of their coexpression in ESCC. Patients and methods: In this single-center retrospective study, immunohistochemistry was performed to evaluate the expression of PN and EGFR in ESCC and paracarcinomatous tissues of 83 patients. The quantitative expression levels of PN and EGFR were examined in two ESCC and tumor-adjacent tissues. The levels of PN and EGFR expression were correlated with clinicopathological parameters by the χ2 or Kruskal–Wallis method. Spearman’s rank correlation test was performed to determine the relationship between PN and EGFR expression levels. Kaplan–Meier and Cox regression analyses were used to detect the prognostic factors of disease-free survival (DFS and overall survival (OS. Results: The high expression of PN protein in ESCC tissues was significantly associated with tumor length (P=0.044, differentiation grade (P=0.003, venous invasion (P=0.010, invasion depth (P=0.007, lymphatic metastasis (P=0.000, and tumor stage (P=0.000. The high expression of EGFR protein in ESCC tissues was only significantly related to lymphatic metastasis (P=0.000, invasion depth (P=0.022, and tumor stage (P=0.000. Kaplan–Meier analysis showed that high expression of PN was closely correlated to reduced OS (P=0.000 and DFS (P=0.000, which was consistent with EGFR expression. Cox regression analysis identified PN and EGFR as independent poor prognostic factors of OS and DFS

  8. EGFR-inhibitors, radiotherapy and normal tissue toxicity

    DEFF Research Database (Denmark)

    Eriksen, J. G.

    2015-01-01

    EGFR-inhibitors have been used in several clinical settings during the last decade and side-effects related to normal tissues like the skin, mucosa and kidney has been well described. However, when EGFR-inhibitors are combined with radiotherapy, then different skin and mucosa toxicity profiles can...... will be explained with references to the current knowledge of the biology of skin toxicity. Treatment options for acute side-effects in skin and mucosa after bio-radiotherapy is rarely causal. A few attempts have been done; some of them aiming to rephosphorylate the EGFreceptor in the skin with vitamin K3. The talk...... single nucleotide polymorphisms in the EGF-gene that alter the ligand-receptor binding might be responsible for the observed clinical correlation. These data will be discussed in the light of EGFR-inhibition in combination with chemotherapy and/or radiotherapy....

  9. Computational design of binding proteins to EGFR domain II.

    Directory of Open Access Journals (Sweden)

    Yoon Sup Choi

    Full Text Available We developed a process to produce novel interactions between two previously unrelated proteins. This process selects protein scaffolds and designs protein interfaces that bind to a surface patch of interest on a target protein. Scaffolds with shapes complementary to the target surface patch were screened using an exhaustive computational search of the human proteome and optimized by directed evolution using phage display. This method was applied to successfully design scaffolds that bind to epidermal growth factor receptor (EGFR domain II, the interface of EGFR dimerization, with high reactivity toward the target surface patch of EGFR domain II. One potential application of these tailor-made protein interactions is the development of therapeutic agents against specific protein targets.

  10. Determination of Antimicrobial Activity of Pterigynandrum filiforme Hedw.

    Directory of Open Access Journals (Sweden)

    Ali YETGİN

    2017-06-01

    Full Text Available Pterigynandrum filiforme Hedw. is a moss species living in the forests of Central Europe and Anatolia. It is a wide spreading moss. The aim of the antimicrobial studies are discovering new substances which reduce effects of infectious. The antimicrobial activity effect of P. filiforme against 17 bacteria and 1 fungus species was analyzed in this study. 0.27 and 0.93 mg samples were prepared by ethanol extraction method and wide spectrum antimicrobial analysis was performed by disk diffusion method. There is no research in the literature regarding the antimicrobial potential of P. filiforme. Antimicrobial activity was determined in the bacteria treated with P. filiforme samples. These include gram-positive bacteria S. aureus, B. subtilis, L. monocytogenes and E. faecalis; gram-negative bacteria K. pneumoniae and S. enteritidis.

  11. Correlation between egfr expression and accelerated proliferation during radiotherapy of head and neck squamous cell carcinoma

    Directory of Open Access Journals (Sweden)

    Pedicini Piernicola

    2012-08-01

    Full Text Available Abstract Purpose To investigate the correlation between the expression of Epidermal Growth Factor receptor (EGFr and the reduction of the effective doubling time (TD during radiotherapy treatment and also to determine the dose per fraction to be taken into account when the overall treatment time (OTT is reduced in accelerated radiotherapy of head and neck squamous cell carcinoma (HNSCC. Methods A survey of the published papers comparing 3-years of local regional control rate (LCR for a total of 2162 patients treated with conventional and accelerated radiotherapy and with a pretreatment assessment of EGFr expression, was made. Different values of TD were obtained by a model incorporating the overall time corrected biologically effective dose (BED and a 3-year clinical LCR for high and low EGFr groups of patients (HEGFr and LEGFr, respectively. By obtaining the TD from the above analysis and the sub-sites’ potential doubling time (Tpot from flow cytometry and immunohistochemical methods, we were able to estimate the average TD for each sub-site included in the analysis. Moreover, the dose that would be required to offset the modified proliferation occurring in one day (Dprolif, was estimated. Results The averages of TD were 77 (27-9095% days in LEGFr and 8.8 (7.3-11.095% days in HEGFr, if an onset of accelerated proliferation TK at day 21 was assumed. The correspondent HEGFr sub-sites’ TD were 5.9 (6.6, 5.9 (6.6, 4.6 (6.1, 14.3 (12.9 days, with respect to literature immunohistochemical (flow cytometry data of Tpot for Oral-Cavity, Oro-pharynx, Hypo-pharynx, and Larynx respectively. The Dprolif for the HEGFr groups were 0.33 (0.29, 0.33 (0.29, 0.42 (0.31, 0.14 (0.15 Gy/day if α = 0.3 Gy-1 and α/β = 10 Gy were assumed. Conclusions A higher expression of the EGFr leads to enhanced proliferation. This study allowed to quantify the extent of the effect which EGFr expression has in terms of reduced TD and Dprolif for each head and neck

  12. Correlation between EGFr expression and accelerated proliferation during radiotherapy of head and neck squamous cell carcinoma.

    Science.gov (United States)

    Pedicini, Piernicola; Nappi, Antonio; Strigari, Lidia; Jereczek-Fossa, Barbara Alicia; Alterio, Daniela; Cremonesi, Marta; Botta, Francesca; Vischioni, Barbara; Caivano, Rocchina; Fiorentino, Alba; Improta, Giuseppina; Storto, Giovanni; Benassi, Marcello; Orecchia, Roberto; Salvatore, Marco

    2012-08-24

    To investigate the correlation between the expression of Epidermal Growth Factor receptor (EGFr) and the reduction of the effective doubling time (TD) during radiotherapy treatment and also to determine the dose per fraction to be taken into account when the overall treatment time (OTT) is reduced in accelerated radiotherapy of head and neck squamous cell carcinoma (HNSCC). A survey of the published papers comparing 3-years of local regional control rate (LCR) for a total of 2162 patients treated with conventional and accelerated radiotherapy and with a pretreatment assessment of EGFr expression, was made. Different values of TD were obtained by a model incorporating the overall time corrected biologically effective dose (BED) and a 3-year clinical LCR for high and low EGFr groups of patients (HEGFr and LEGFr), respectively. By obtaining the TD from the above analysis and the sub-sites' potential doubling time (Tpot) from flow cytometry and immunohistochemical methods, we were able to estimate the average TD for each sub-site included in the analysis. Moreover, the dose that would be required to offset the modified proliferation occurring in one day (Dprolif), was estimated. The averages of TD were 77 (27-90)95% days in LEGFr and 8.8 (7.3-11.0)95% days in HEGFr, if an onset of accelerated proliferation TK at day 21 was assumed. The correspondent HEGFr sub-sites' TD were 5.9 (6.6), 5.9 (6.6), 4.6 (6.1), 14.3 (12.9) days, with respect to literature immunohistochemical (flow cytometry) data of Tpot for Oral-Cavity, Oro-pharynx, Hypo-pharynx, and Larynx respectively. The Dprolif for the HEGFr groups were 0.33 (0.29), 0.33 (0.29), 0.42 (0.31), 0.14 (0.15) Gy/day if α = 0.3 Gy-1 and α/β = 10 Gy were assumed. A higher expression of the EGFr leads to enhanced proliferation. This study allowed to quantify the extent of the effect which EGFr expression has in terms of reduced TD and Dprolif for each head and neck sub-site.

  13. Nicotinamide attenuates aquaporin 3 overexpression induced by retinoic acid through inhibition of EGFR/ERK in cultured human skin keratinocytes.

    Science.gov (United States)

    Song, Xiuzu; Xu, Aie; Pan, Wei; Wallin, Brittany; Kivlin, Rebecca; Lu, Shan; Cao, Cong; Bi, Zhigang; Wan, Yinsheng

    2008-08-01

    The most common adverse effects that are related to all-trans retinoic acid (atRA) treatment are irritation and dryness of the skin. atRA therapy is reported to impair barrier function as achieved by trans-epidermal water loss (TEWL). Treatment with nicotinamide prior to initiation of atRA therapy provides additional barrier protection and thus reduces susceptibility of retinoic acid. Our previous studies showed that atRA upregulates aquaporin 3 (AQP3) in cultured human skin keratinocytes and fibroblasts. Others have demonstrated that in atopic dermatitis, overexpression of AQP3 is linked to elevated TEWL and that nicotinamide treatment reduces skin TEWL. In this study, we observed that while atRA upregulates AQP3 expression in cultured human skin keratinocytes (HaCaT cells), nicotinamide attenuates the effect of atRA in a concentration-dependent manner. atRA treatment induces EGFR and ERK activation. PD153035, an EGFR inhibitor, and U0126, an ERK inhibitor, inhibit atRA-induced upregulation of AQP3. Nicotinamide also inhibits atRA-induced activation of EGFR/ERK signal transduction and decreases water permeability by downregulating AQP3 expression. Collectively, our results indicate that the effect of atRA on AQP3 expression is at least partly mediated by EGFR/ERK signaling in cultured human skin keratinocytes. Nicotinamide attenuates atRA-induced AQP3 expression through inhibition of EGFR/ERK signal transduction and eventually decreases water permeability and water loss. Our study provides insights into the molecular mechanism through which nicotinamide reverses the side effects of dryness in human skin after treatment with atRA.

  14. Preclinical PET imaging of EGFR levels: pairing a targeting with a non-targeting Sel-tagged Affibody-based tracer to estimate the specific uptake.

    Science.gov (United States)

    Cheng, Qing; Wållberg, Helena; Grafström, Jonas; Lu, Li; Thorell, Jan-Olov; Hägg Olofsson, Maria; Linder, Stig; Johansson, Katarina; Tegnebratt, Tetyana; Arnér, Elias S J; Stone-Elander, Sharon; Ahlzén, Hanna-Stina Martinsson; Ståhl, Stefan

    2016-12-01

    Though overexpression of epidermal growth factor receptor (EGFR) in several forms of cancer is considered to be an important prognostic biomarker related to poor prognosis, clear correlations between biomarker assays and patient management have been difficult to establish. Here, we utilize a targeting directly followed by a non-targeting tracer-based positron emission tomography (PET) method to examine some of the aspects of determining specific EGFR binding in tumors. The EGFR-binding Affibody molecule ZEGFR:2377 and its size-matched non-binding control ZTaq:3638 were recombinantly fused with a C-terminal selenocysteine-containing Sel-tag (ZEGFR:2377-ST and ZTaq:3638-ST). The proteins were site-specifically labeled with DyLight488 for flow cytometry and ex vivo tissue analyses or with (11)C for in vivo PET studies. Kinetic scans with the (11)C-labeled proteins were performed in healthy mice and in mice bearing xenografts from human FaDu (squamous cell carcinoma) and A431 (epidermoid carcinoma) cell lines. Changes in tracer uptake in A431 xenografts over time were also monitored, followed by ex vivo proximity ligation assays (PLA) of EGFR expressions. Flow cytometry and ex vivo tissue analyses confirmed EGFR targeting by ZEGFR:2377-ST-DyLight488. [Methyl-(11)C]-labeled ZEGFR:2377-ST-CH3 and ZTaq:3638-ST-CH3 showed similar distributions in vivo, except for notably higher concentrations of the former in particularly the liver and the blood. [Methyl-(11)C]-ZEGFR:2377-ST-CH3 successfully visualized FaDu and A431 xenografts with moderate and high EGFR expression levels, respectively. However, in FaDu tumors, the non-specific uptake was large and sometimes equally large, illustrating the importance of proper controls. In the A431 group observed longitudinally, non-specific uptake remained at same level over the observation period. Specific uptake increased with tumor size, but changes varied widely over time in individual tumors. Total (membranous and cytoplasmic) EGFR

  15. Does Nucleos(tide Analogues Treatment Affect Renal Function in Chronic Hepatitis B Patients Who Have Already Decreased eGFR? A Longitudinal Study.

    Directory of Open Access Journals (Sweden)

    Ming-Chao Tsai

    Full Text Available This study aimed to assess the renal function in chronic hepatitis B (CHB patients who received nucleos(tide analogues (NAs therapy using estimated glomerular filtration rate (eGFR titer. We performed a longitudinal observational study of 37 tenofovir-, 42 telbivudine-, and 62 entecavir-naïve CHB patients, who had impaired renal function (eGFR, 90-30 ml/min/1.73m2 without history of diabetes, hypertension, and chemotherapy. Calculation and evaluation of eGFR was performed with the Modification of Diet in Renal Disease, Chronic Kidney Disease Epidemiology Collaboration, and Cockcroft-Gault formula at pretreatment, at baseline, and after the 1st and 2nd year of treatment. The eGFR was significantly increased in patients given telbivudine or entecavir (p = 0.003 and p = 0.012, respectively, but the eGFR was decreased in patients given tenofovir (p = 0.001 after 2 years of treatment. Of all patients, eGFR was stable one year prior to treatment. If we analyzed the renal function by change of chronic kidney disease (CKD category with a change of 25% of eGFR, the proportion of uncertain drop (drop in CKD category with <25% decrease in eGFR and certain drop (drop in CKD category with ≧25% decrease in eGFR in tenofovir group was smaller (5.4% than those of telbivudine (12.9% or entecavir (6.5%. Furthermore, telbivudine had the lowest stable rate (76.2%, the highest certain rise rate (9.5%, and certain drop rate (7.1% compared to the other groups (p = 0.049. In conclusion, in NAs-naïve CHB patients with impaired renal function, telbivudine and entecavir resulted in a significant increase in eGFR while tenofovir resulted in a significant decrease after a 2-year treatment. Interestingly, TDF had the lowest proportion of patients reclassified to certain and uncertain drop groups; in contrast, LdT had a higher proportion in both raise and drop groups. The outcomes of this renal effect remain to be determined.

  16. Effect of siRNAs targeting the EGFR T790M mutation in a non-small cell lung cancer cell line resistant to EGFR tyrosine kinase inhibitors and combination with various agents.

    Science.gov (United States)

    Chen, Gang; Kronenberger, Peter; Teugels, Erik; Umelo, Ijeoma Adaku; De Grève, Jacques

    2013-02-15

    The epidermal growth factor receptor (EGFR) is a validated therapeutic target in non-small cell lung cancer (NSCLC). However, some mutations confer resistance to current available agents, especially the frequently occurring T790M mutation. In the current study, we have examined, in a NSCLC cell line H1975 containing both L858R and T790M mutations, the effect of T790M-specific-siRNAs versus other EGFR-specific-siRNAs. T790M-specific-siRNAs were able to inhibit T790M and EGFR mRNA, to reduce EGFR protein expression, as well as to reduce the cell growth and induce cell caspase activity in H1975 cells. However, this effect showed less potency compared to the other EGFR-specific-siRNAs. EGFR-specific-siRNAs strongly inhibited cell growth and induced apoptosis in H358, H1650, H292, HCC827 and also in H1975 cells, which showed weak response to tyrosine kinase inhibitors (TKIs) or cetuximab. The addition of T790M-specific-siRNAs could rescue the sensitivity of T790M mutant H1975 cells to TKIs. The combination of T790M-specific-siRNAs and cetuximab also additively enhanced cell growth inhibition and induction of apoptosis in H1975 cells. Among the anti-EGFR agents tested, the strongest biological effect was observed when afatinib was combined with T790M-specific-siRNAs. Afatinib also offered extra effect when combined with cetuximab in H1975 cells. In conclusion, knock-down of T790M transcript by siRNAs further decreases the cell growth of T790M mutant lung cancer cells that are treated with TKIs or cetuximab. The combination of a potent, irreversible kinase inhibitor such as afatinib, with T790M-specific-siRNAs should be further investigated as a new strategy in the treatment of lung cancer containing the resistant T790M mutation. Copyright © 2012 Elsevier Inc. All rights reserved.

  17. EGF stimulates the activation of EGF receptors and the selective activation of major signaling pathways during mitosis.

    Science.gov (United States)

    Wee, Ping; Shi, Huaiping; Jiang, Jennifer; Wang, Yuluan; Wang, Zhixiang

    2015-03-01

    Mitosis and epidermal growth factor (EGF) receptor (EGFR) are both targets for cancer therapy. The role of EGFR signaling in mitosis has been rarely studied and poorly understood. The limited studies indicate that the activation of EGFR and downstream signaling pathways is mostly inhibited during mitosis. However, we recently showed that EGFR is phosphorylated in response to EGF stimulation in mitosis. Here we studied EGF-induced EGFR activation and the activation of major signaling pathways downstream of EGFR during mitosis. We showed that EGFR was strongly activated by EGF during mitosis as all the five major tyrosine residues including Y992, Y1045, Y1068, Y1086, and Y1173 were phosphorylated to a level similar to that in the interphase. We further showed that the activated EGFR is able to selectively activate some downstream signaling pathways while avoiding others. Activated EGFR is able to activate PI3K and AKT2, but not AKT1, which may be responsible for the observed effects of EGF against nocodazole-induced cell death. Activated EGFR is also able to activate c-Src, c-Cbl and PLC-γ1 during mitosis. However, activated EGFR is unable to activate ERK1/2 and their downstream substrates RSK and Elk-1. While it activated Ras, EGFR failed to fully activate Raf-1 in mitosis due to the lack of phosphorylation at Y341 and the lack of dephosphorylation at pS259. We conclude that contrary to the dogma, EGFR is activated by EGF during mitosis. Moreover, EGFR-mediated cell signaling is regulated differently from the interphase to specifically serve the needs of the cell in mitosis. Copyright © 2015 Elsevier Inc. All rights reserved.

  18. Fast Photochemical Oxidation of Proteins (FPOP) Maps the Epitope of EGFR Binding to Adnectin

    Science.gov (United States)

    Yan, Yuetian; Chen, Guodong; Wei, Hui; Huang, Richard Y.-C.; Mo, Jingjie; Rempel, Don L.; Tymiak, Adrienne A.; Gross, Michael L.

    2014-12-01

    Epitope mapping is an important tool for the development of monoclonal antibodies, mAbs, as therapeutic drugs. Recently, a class of therapeutic mAb alternatives, adnectins, has been developed as targeted biologics. They are derived from the 10th type III domain of human fibronectin (10Fn3). A common approach to map the epitope binding of these therapeutic proteins to their binding partners is X-ray crystallography. Although the crystal structure is known for Adnectin 1 binding to human epidermal growth factor receptor (EGFR), we seek to determine complementary binding in solution and to test the efficacy of footprinting for this purpose. As a relatively new tool in structural biology and complementary to X-ray crystallography, protein footprinting coupled with mass spectrometry is promising for protein-protein interaction studies. We report here the use of fast photochemical oxidation of proteins (FPOP) coupled with MS to map the epitope of EGFR-Adnectin 1 at both the peptide and amino-acid residue levels. The data correlate well with the previously determined epitopes from the crystal structure and are consistent with HDX MS data, which are presented in an accompanying paper. The FPOP-determined binding interface involves various amino-acid and peptide regions near the N terminus of EGFR. The outcome adds credibility to oxidative labeling by FPOP for epitope mapping and motivates more applications in the therapeutic protein area as a stand-alone method or in conjunction with X-ray crystallography, NMR, site-directed mutagenesis, and other orthogonal methods.

  19. A gasometric method to determine erythrocyte catalase activity

    Directory of Open Access Journals (Sweden)

    A.J.S. Siqueira

    1999-09-01

    Full Text Available We describe a new gasometric method to determine erythrocyte catalase activity by the measurement of the volume of oxygen produced as a result of hydrogen peroxide decomposition in a system where enzyme and substrate are separated in a special reaction test tube connected to a manometer and the reagents are mixed with a motor-driven stirrer. The position of the reagents in the test tube permits the continuous measurement of oxygen evolution from the time of mixing, without the need to stop the reaction by the addition of acid after each incubation time. The enzyme activity is reported as KHb, i.e., mg hydrogen peroxide decomposed per second per gram of hemoglobin (s-1 g Hb-1. The value obtained for catalase activity in 28 samples of hemolyzed human blood was 94.4 ± 6.17 mg H2O2 s-1 g Hb-1. The results obtained were precise and consistent, indicating that this rapid, simple and inexpensive method could be useful for research and routine work.

  20. Modelling the correlation between EGFr expression and tumour cell radiosensitivity, and combined treatments of radiation and monoclonal antibody EGFr inhibitors

    Directory of Open Access Journals (Sweden)

    Pedicini Piernicola

    2012-06-01

    Full Text Available Abstract Purpose To estimate the effects of heterogeneity on tumour cell sensitivity to radiotherapy combined with radiosensitizing agents attributable to differences in expression levels of Epidermal Growth Factor Receptor (EGFr. Materials and methods Differences in radiosensitivity are not limited to cells of different cancer histotypes but also occur within the same cancer, or appear during radiotherapy if radiosensitizing drugs are combined with ionizing radiation. A modified biologically effective dose (MBED, has been introduced to account for changes in radiosensitivity parameters (α and α/β rather than changes in dose/fraction or total dose as normally done with standard biologically effective dose (BED. The MBED approach was applied to cases of EGFr over-expression and cases where EGFr inhibitors were combined with radiation. Representative examples in clinical practice were considered. Results Assuming membrane EGFr over-expression corresponds to reduced radiosensitivity (αH = 0.15 Gy-1 and αH/βH = 7.5 Gy relative to normal radiosensitivity (α = 0.2 Gy-1 and α/β = 10 Gy, an increased dose per fraction of 2.42 Gy was obtained through the application of MBED, which is equivalent to the effect of a reference schedule with 30 fractions of 2 Gy. An equivalent hypo-fractionated regime with a dose per fraction of 2.80 Gy is obtained if 25 fractions are set. Dose fractionations modulated according to drug pharmacokinetics are estimated for combined treatments with biological drugs. Soft and strong modulated equivalent hypo-fractionations result from subtraction of 5 or 10 fractions, respectively. Conclusions During this computational study, a new radiobiological tool has been introduced. The MBED allows the required dose per fraction to be estimated when tumour radiosensitivity is reduced because EGFr is over-expressed. If radiotherapy treatment is combined with EGFr inhibitors, MBED suggests new treatment strategies

  1. EGFR tyrosine kinase inhibitors versus chemotherapy in EGFR wild-type pre-treated advanced nonsmall cell lung cancer in daily practice

    Science.gov (United States)

    Tomasini, Pascale; Brosseau, Solenn; Mazières, Julien; Merlio, Jean-Philippe; Beau-Faller, Michèle; Mosser, Jean; Wislez, Marie; Ouafik, L'Houcine; Besse, Benjamin; Rouquette, Isabelle; Debieuvre, Didier; Escande, Fabienne; Westeel, Virginie; Audigier-Valette, Clarisse; Missy, Pascale; Langlais, Alexandra; Morin, Frank; Moro-Sibilot, Denis; Zalcman, Gérard

    2017-01-01

    Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) are approved for second-line treatment of EGFR wild-type (EGFR-wt) nonsmall cell lung cancer (NSCLC). However, results from randomised trials performed to compare EGFR-TKIs with chemotherapy in this population did not show any survival benefit. In the era of immunotherapy, many drugs are approved for second-line treatment of EGFR-wt NSCLC and there is a need to reassess the role of EGFR-TKIs in this setting. The Biomarkers France study is a large nationwide cohort of NSCLC patients tested for EGFR mutations. We used this database to collect clinical, biological, treatment and outcome data on EGFR-wt patients who received second-line treatment with either EGFR-TKIs or chemotherapy. Among 1278 patients, 868 received chemotherapy and 410 received an EGFR-TKI. Median overall survival and progression-free survival were longer with chemotherapy than with an EGFR-TKI. Overall survival was 8.38 versus 4.99 months, respectively (hazard ratio 0.70, 95% CI 0.59–0.83; p<0.0001) and progression-free survival was 4.30 versus 2.83 months, respectively (hazard ratio 0.66, 95% CI 0.57–0.77; p<0.0001). This study is helpful to guide a multiline treatment strategy for EGFR-wt NSCLC patients. Immunotherapy is approved for second-line treatment. For third-line treatment, chemotherapy results in longer overall survival and progression-free survival, and should be preferred to EGFR-TKIs. PMID:28798090

  2. Proton energy determination using activated yttrium foils and ionization chambers for activity assay

    Science.gov (United States)

    Avila-Rodriguez, M. A.; Rajander, J.; Lill, J.-O.; Gagnon, K.; Schlesinger, J.; Wilson, J. S.; McQuarrie, S. A.; Solin, O.

    2009-05-01

    Excitation functions of the 89Y(p, xn) nuclear reactions were measured up to 18 MeV by the conventional activation method using the stacked-foil technique, and the irradiation of single foils. Activity assays of the irradiated foils were performed via ionization chamber and gamma spectroscopy methods. Activity ratios of the activation products were measured in two different facilities and evaluated for use as a practical and simple method for proton energy determinations. Cross section values measured in this work were compared with published data and with theoretical values as determined by the nuclear reaction model code EMPIRE II. In general, there was a good agreement between the experimental and theoretical values of the cross section data. Activity ratios of the isomeric and ground state of 89Zr measured via ionization chamber were found to be useful for proton energy determinations in the energy range from 7 to 15 MeV. Proton energies above 13 MeV were accurately determined using the 89gZr/ 88Zr and 89gZr/ 88Y activity ratios measured via gamma spectroscopy.

  3. Osimertinib benefit in EGFR-mutant NSCLC patients with T790M-mutation detected by circulating tumour DNA.

    Science.gov (United States)

    Remon, J; Caramella, C; Jovelet, C; Lacroix, L; Lawson, A; Smalley, S; Howarth, K; Gale, D; Green, E; Plagnol, V; Rosenfeld, N; Planchard, D; Bluthgen, M V; Gazzah, A; Pannet, C; Nicotra, C; Auclin, E; Soria, J C; Besse, B

    2017-04-01

    Approximately 50% of epidermal growth factor receptor (EGFR) mutant non-small cell lung cancer (NSCLC) patients treated with EGFR tyrosine kinase inhibitors (TKIs) will acquire resistance by the T790M mutation. Osimertinib is the standard of care in this situation. The present study assesses the efficacy of osimertinib when T790M status is determined in circulating cell-free tumour DNA (ctDNA) from blood samples in progressing advanced EGFR-mutant NSCLC patients. ctDNA T790M mutational status was assessed by Inivata InVision™ (eTAm-Seq™) assay in 48 EGFR-mutant advanced NSCLC patients with acquired resistance to EGFR TKIs without a tissue biopsy between April 2015 and April 2016. Progressing T790M-positive NSCLC patients received osimertinib (80 mg daily). The objectives were to assess the response rate to osimertinib according to Response Evaluation Criteria in Solid Tumours (RECIST) 1.1, the progression-free survival (PFS) on osimertinib, and the percentage of T790M positive in ctDNA. The ctDNA T790M mutation was detected in 50% of NSCLC patients. Among assessable patients, osimertinib gave a partial response rate of 62.5% and a stable disease rate of 37.5%. All responses were confirmed responses. After median follow up of 8 months, median PFS by RECIST criteria was not achieved (95% CI: 4-NA), with 6- and 12-months PFS of 66.7% and 52%, respectively. ctDNA from liquid biopsy can be used as a surrogate marker for T790M in tumour tissue.

  4. Serum ZAG Levels Were Associated with eGFR Mild Decrease in T2DM Patients with Diabetic Nephropathy

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    Lingling Xu

    2017-01-01

    Full Text Available Objective. To investigate the changes of serum zinc-α2-glycoprotein (ZAG in type 2 diabetes mellitus (T2DM with eGFR mild decrease. Subjects and Methods. A total of 438 T2DM patients (61.3 ± 4.0 y were recruited and the demographic, anthropometric, and biochemical parameters were all collected. Serum ZAG levels were determined by commercially available ELISA kits. Results. The proportion of T2DM patients with the high tertile ZAG levels was 11.9% higher in patients with mildly decreased estimated glomerular filtration rate (eGFR (<90 mL/min/1.73 m2 than those with the low tertile ZAG levels P=0.038. The probability of the eGFR<90 mL/min/1.73 m2 in patients with the high ZAG levels was 94% higher than those with the low serum ZAG levels after adjusting for age, gender, and education [OR = 1.94, 95% CI (1.17–3.23, P=0.0094]. This phenomenon was more likely to be observed in the condition of uACR ≥ 2.7 mg/mmol, WC ≥ 90 cm for men, or WC ≥ 85 cm for women. Conclusion. Serum ZAG levels were firstly found to be related with eGFR in T2DM patients. The patients with the high tertile ZAG levels were more likely to have mildly eGFR decrease, especially for female patients with higher uACR and bigger WC.

  5. Soybean phospholipase D activity determination. A comparison of two methods

    Directory of Open Access Journals (Sweden)

    Ré, E.

    2007-09-01

    Full Text Available Due to a discrepancy between previously published results, two methods to determine the soybean phospholipase D activity were evaluated. One method is based on the extraction of the enzyme from whole soybean flour, quantifying the enzyme activity on the extract. The other method quantifies the enzymatic activity on whole soybean flour without enzyme extraction. In the extraction-based-method, both the extraction time and the number of extractions were optimized. The highest phospholipase D activity values were obtained from the method without enzyme extraction. This method is less complex, requires less running-time and the conditions of the medium in which phospholipase D acts resemble the conditions found in the oil industrySe evaluaron dos métodos para determinar la actividad de la fosfolipasa D en soja debido a que existe discrepancia entre los resultados publicados. Un método se basa en la extracción de la enzima de la harina resultante de la molienda del grano de soja entero, cuantificando la actividad sobre el extracto. En el otro método, la cuantificación se realiza sobre la harina del grano entero molido, sin extraer la enzima. En el método de extracción se optimizaron tanto el tiempo como el número de extracciones. Los mayores valores de actividad de la fosfolipasa D se obtuvieron por el método sin extracción de la enzima. Este método es más simple, exige menos tiempo de ejecución y las condiciones del medio en que actúa la fosfolipasa D se asemejan a las condiciones encontradas en la industria aceitera.

  6. EGFR Signaling in the Brain Is Necessary for Olfactory Learning in "Drosophila" Larvae

    Science.gov (United States)

    Rahn, Tasja; Leippe, Matthias; Roeder, Thomas; Fedders, Henning

    2013-01-01

    Signaling via the epidermal growth factor receptor (EGFR) pathway has emerged as one of the key mechanisms in the development of the central nervous system in "Drosophila melanogaster." By contrast, little is known about the functions of EGFR signaling in the differentiated larval brain. Here, promoter-reporter lines of EGFR and its most prominent…

  7. Regulation of EGFR Protein Stability by the HECT-type Ubiquitin Ligase SMURF2

    Directory of Open Access Journals (Sweden)

    Dipankar Ray

    2011-07-01

    Full Text Available Epidermal growth factor receptor (EGFR is overexpressed in a variety of epithelial tumors and is considered to be an important therapeutic target. Although gene amplification is responsible for EGFR overexpression in certain human malignancies including lung and head and neck cancers, additional molecular mechanisms are likely. Here, we report a novel interaction of EGFR with an HECT-type ubiquitin ligase SMURF2, which can ubiquitinate, but stabilize EGFR by protecting it from c-Cbl-mediated degradation. Conversely, small interfering RNA (siRNA-mediated knockdown of SMURF2 destabilized EGFR, induced an autophagic response and reduced the clonogenic survival of EGFR-expressing cancer cell lines, with minimal effects on EGFR-negative cancer cells, normal fibroblasts, and normal epithelial cells. UMSCC74B head and neck squamous cancer cells, which form aggressive tumors in nudemice, significantly lost in vivo tumor-forming ability on siRNA-mediated SMURF2 knockdown. Gene expressionmicroarray data from 443 lung adenocarcinoma patients, and tissue microarray data from 67 such patients, showed a strong correlation of expression between EGFR and SMURF2 at the messenger RNA and protein levels, respectively. Our findings suggest that SMURF2-mediated protective ubiquitination of EGFR may be responsible for EGFR overexpression in certain tumors and support targeting SMURF2-EGFR interaction as a novel therapeutic approach in treating EGFR-addicted tumors.

  8. Construction of a high-EGFR expression cell line and its biological ...

    African Journals Online (AJOL)

    Targeted screening of EGFR compounds has become one of the medical research focuses for tumor therapy. A431, which naturally expresses high levels of EGFR, was compared with the stably high expressing EGFR cell line HEK293. Flow cytometry was used to analyze cell growth and Western blot was used to ...

  9. Drosophila Zpr1 (Zinc finger protein 1 is required downstream of both EGFR and FGFR signaling in tracheal subcellular lumen formation.

    Directory of Open Access Journals (Sweden)

    Oscar E Ruiz

    Full Text Available The cellular and molecular cues involved in creating branched tubular networks that transport liquids or gases throughout an organism are not well understood. To identify factors required in branching and lumen formation of Drosophila tracheal terminal cells, a model for branched tubular networks, we performed a forward genetic-mosaic screen to isolate mutations affecting these processes. From this screen, we have identified the first Drosophila mutation in the gene Zpr1 (Zinc finger protein 1 by the inability of Zpr1-mutant terminal cells to form functional, gas-filled lumens. We show that Zpr1 defective cells initiate lumen formation, but are blocked from completing the maturation required for gas filling. Zpr1 is an evolutionarily conserved protein first identified in mammalian cells as a factor that binds the intracellular domain of the unactivated epidermal growth factor receptor (EGFR. We show that down-regulation of EGFR in terminal cells phenocopies Zpr1 mutations and that Zpr1 is epistatic to ectopic lumen formation driven by EGFR overexpression. However, while Zpr1 mutants are fully penetrant, defects observed when reducing EGFR activity are only partially penetrant. These results suggest that a distinct pathway operating in parallel to the EGFR pathway contributes to lumen formation, and this pathway is also dependent on Zpr1. We provide evidence that this alternative pathway may involve fibroblast growth factor receptor (FGFR signaling. We suggest a model in which Zpr1 mediates both EGFR and FGFR signal transduction cascades required for lumen formation in terminal cells. To our knowledge, this is the first genetic evidence placing Zpr1 downstream of EGFR signaling, and the first time Zpr1 has been implicated in FGFR signaling. Finally, we show that down-regulation of Smn, a protein known to interact with Zpr1 in mammalian cells, shows defects similar to Zpr1 mutants.

  10. Antiproliferative effect of growth hormone-releasing hormone (GHRH antagonist on ovarian cancer cells through the EGFR-Akt pathway

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    Varga Jozsef

    2010-05-01

    Full Text Available Abstract Background Antagonists of growth hormone-releasing hormone (GHRH are being developed for the treatment of various human cancers. Methods MTT assay was used to test the proliferation of SKOV3 and CaOV3. The splice variant expression of GHRH receptors was examined by RT-PCR. The expression of protein in signal pathway was examined by Western blotting. siRNA was used to block the effect of EGFR. Results In this study, we investigated the effects of a new GHRH antagonist JMR-132, in ovarian cancer cell lines SKOV3 and CaOV3 expressing splice variant (SV1 of GHRH receptors. MTT assay showed that JMR-132 had strong antiproliferative effects on SKOV3 and CaOV3 cells in both a time-dependent and dose-dependent fashion. JMR-132 also induced the activation and increased cleaved caspase3 in a time- and dose-dependent manner in both cell lines. In addition, JMR-132 treatments decreased significantly the epidermal growth factor receptor (EGFR level and the phosphorylation of Akt (p-Akt, suggesting that JMR-132 inhibits the EGFR-Akt pathway in ovarian cancer cells. More importantly, treatment of SKOV3 and CaOV3 cells with 100 nM JMR-132 attenuated proliferation and the antiapoptotic effect induced by EGF in both cell lines. After the knockdown of the expression of EGFR by siRNA, the antiproliferative effect of JMR-132 was abolished in SKOV3 and CaOV3 cells. Conclusions The present study demonstrates that the inhibitory effect of the GHRH antagonist JMR-132 on proliferation is due, in part, to an interference with the EGFR-Akt pathway in ovarian cancer cells.

  11. 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

  12. Decreased EGFR mRNA expression in response to antipsoriatic ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-07-20

    Jul 20, 2009 ... tors (Hashimoto, 2000). Of these mediators, the most crucial mechanism for the proliferation of keratinocytes is the signal from the EGFR. The EGF family consists of. EGF, TGF-α, heparin binding EGF-like growth factor (HB-. EGF), amphiregulin, epiregulin, betacellulin, epigen, neu- regulin (NRG)-1, NRG-2, ...

  13. GPR54 (KISS1R) transactivates EGFR to promote breast cancer cell invasiveness.

    Science.gov (United States)

    Zajac, Mateusz; Law, Jeffrey; Cvetkovic, Dragana Donna; Pampillo, Macarena; McColl, Lindsay; Pape, Cynthia; Di Guglielmo, Gianni M; Postovit, Lynne M; Babwah, Andy V; Bhattacharya, Moshmi

    2011-01-01

    Kisspeptins (Kp), peptide products of the Kisspeptin-1 (KISS1) gene are endogenous ligands for a G protein-coupled receptor 54 (GPR54). Previous findings have shown that KISS1 acts as a metastasis suppressor in numerous cancers in humans. However, recent studies have demonstrated that an increase in KISS1 and GPR54 expression in human breast tumors correlates with higher tumor grade and metastatic potential. At present, whether or not Kp signaling promotes breast cancer cell invasiveness, required for metastasis and the underlying mechanisms, is unknown. We have found that kisspeptin-10 (Kp-10), the most potent Kp, stimulates the invasion of human breast cancer MDA-MB-231 and Hs578T cells using Matrigel-coated Transwell chamber assays and induces the formation of invasive stellate structures in three-dimensional invasion assays. Furthermore, Kp-10 stimulated an increase in matrix metalloprotease (MMP)-9 activity. We also found that Kp-10 induced the transactivation of epidermal growth factor receptor (EGFR). Knockdown of the GPCR scaffolding protein, β-arrestin 2, inhibited Kp-10-induced EGFR transactivation as well as Kp-10 induced invasion of breast cancer cells via modulation of MMP-9 secretion and activity. Finally, we found that the two receptors associate with each other under basal conditions, and FRET analysis revealed that GPR54 interacts directly with EGFR. The stability of the receptor complex formation was increased upon treatment of cells by Kp-10. Taken together, our findings suggest a novel mechanism by which Kp signaling via GPR54 stimulates breast cancer cell invasiveness.

  14. GPR54 (KISS1R transactivates EGFR to promote breast cancer cell invasiveness.

    Directory of Open Access Journals (Sweden)

    Mateusz Zajac

    Full Text Available Kisspeptins (Kp, peptide products of the Kisspeptin-1 (KISS1 gene are endogenous ligands for a G protein-coupled receptor 54 (GPR54. Previous findings have shown that KISS1 acts as a metastasis suppressor in numerous cancers in humans. However, recent studies have demonstrated that an increase in KISS1 and GPR54 expression in human breast tumors correlates with higher tumor grade and metastatic potential. At present, whether or not Kp signaling promotes breast cancer cell invasiveness, required for metastasis and the underlying mechanisms, is unknown. We have found that kisspeptin-10 (Kp-10, the most potent Kp, stimulates the invasion of human breast cancer MDA-MB-231 and Hs578T cells using Matrigel-coated Transwell chamber assays and induces the formation of invasive stellate structures in three-dimensional invasion assays. Furthermore, Kp-10 stimulated an increase in matrix metalloprotease (MMP-9 activity. We also found that Kp-10 induced the transactivation of epidermal growth factor receptor (EGFR. Knockdown of the GPCR scaffolding protein, β-arrestin 2, inhibited Kp-10-induced EGFR transactivation as well as Kp-10 induced invasion of breast cancer cells via modulation of MMP-9 secretion and activity. Finally, we found that the two receptors associate with each other under basal conditions, and FRET analysis revealed that GPR54 interacts directly with EGFR. The stability of the receptor complex formation was increased upon treatment of cells by Kp-10. Taken together, our findings suggest a novel mechanism by which Kp signaling via GPR54 stimulates breast cancer cell invasiveness.

  15. Gene copy number variation and protein overexpression of EGFR and HER2 in distal extrahepatic cholangiocarcinoma.

    Science.gov (United States)

    Jung, Min Jung; Woo, Chang Gok; Lee, Saetbyeol; Chin, Susie; Kim, Hee Kyung; Kwak, Jeong Ja; Koh, Eun Suk; Lee, Bora; Jang, Kee-Taek; Moon, Ahrim

    2017-10-01

    EGFR and HER2 are among the most promising therapeutic targets in solid cancers. The expression status of EGFR and HER2 are associated with the prognosis, and with a number of clinicopathological factors, in many cancers. However, few studies have examined this association in distal extrahepatic cholangiocarcinoma (EHCC). Therefore, we investigated EGFR and HER2 protein expression and gene copy number variation (CNV) in distal EHCC. We also studied the association of these factors with clinicopathological parameters and prognosis. Immunostaining, using antibodies against EGFR and HER2, was performed on 84 cases of distal EHCC. All positive (3+) and equivocal (2+) EGFR and HER2 expression cases, together with randomly selected negative (1+ and 0) cases, were evaluated for EGFR and HER2 CNV. Among distal EHCC samples, 6.0% (n=5) were positive (3+) for EGFR expression and 6.0% (n=5) were equivocal (2+). HER2 expression was positively identified in 2.4% of samples (n=2), and was equivocal in 1.2% of samples (n=1). All cases of positive EGFR expression showed amplification (n=1) or high polysomy (n=4) involving the EGFR gene; three cases (60%) of equivocal EGFR expression showed high polysomy of the EGFR gene. All cases of positive or equivocal HER2 expression (n=3, 3.6%) showed amplification of the HER2 gene. In univariate analysis, EGFR expression and CNV were associated with shorter cancer-specific overall survival (p=0.003 and p=0.018, respectively). Multivariate analysis also showed that EGFR CNV was a significant prognostic factor in distal EHCC (p=0.015). Although further study is warranted, our findings suggest that EGFR expression and CNV are factors associated with poor prognosis, and that anticancer therapeutics against EGFR and HER2 receptors may be promising therapeutic options for patients with distal EHCC. Copyright © 2017 Royal College of Pathologists of Australasia. Published by Elsevier B.V. All rights reserved.

  16. [Lung adenocarcinoma with concomitant EGFR mutation and ALK rearrangement].

    Science.gov (United States)

    Caliez, J; Monnet, I; Pujals, A; Rousseau-Bussac, G; Jabot, L; Boudjemaa, A; Leroy, K; Chouaid, C

    2017-05-01

    Among patients with non-small-cell lung cancer, coexistence of EGFR mutation and ALK rearrangement is rare. We describe the clinical features of two patients with this double anomaly. A 62-year-old Caucasian non-smoking woman was diagnosed with cT4N0M0 lung adenocarcinoma. Initial biopsy showed EGFR mutation and ALK rearrangement. She received cisplatin-gemcitabine, followed by 17 months of gemcitabine. Owing to progression, she received erlotinib for 14 months, then paclitaxel for 6 months and finally crizotinib. A partial response was achieved and maintained for 24 months. A 45-year-old Caucasian woman, light smoker, was diagnosed with cT2N3M0 lung adenocarcinoma. Only EGFR mutation was found on initial analysis. She underwent treatment with cisplatin-gemcitabine and thoracic radiotherapy. Progression occurred after 8 months and afatinbib was started. Eight months later, progression was observed with a neoplasic pleural effusion in which tumor cells expressing ALK rearrangement were found. A new FISH analysis was performed on the initial tumor but did not find this rearrangement. Despite a third line of crizotinib, the patient died one month later. The literature shows 45 other cases of these two abnormalities, observed either from the start or during follow-up. EGFR's TKI were almost always given before ALK's TKI. Therapeutic strategy needs to be clarified in cases of double alteration. With regard to the second patient, appearance of ALK rearrangement may constitute a resistance mechanism to EGFR's TKI. Copyright © 2016 SPLF. Published by Elsevier Masson SAS. All rights reserved.

  17. Role of epidermal growth factor receptor activation in regulating mucin synthesis

    Directory of Open Access Journals (Sweden)

    Nadel Jay A

    2001-02-01

    Full Text Available Abstract Healthy individuals have few goblet cells in their airways, but in patients with hypersecretory diseases goblet-cell upregulation results in mucus hypersecretion, airway plugging, and death. Multiple stimuli produce hypersecretion via epidermal growth factor receptor (EGFR expression and activation, causing goblet-cell metaplasia from Clara cells by a process of cell differentiation. These cells are also believed to be the cells of origin of non-small-cell lung cancer, but this occurs via cell multiplication. The mechanisms that determine which pathway is chosen are critical but largely unknown. Although no effective therapy exists for hypersecretion at present, the EGFR cascade suggests methods for effective therapeutic intervention.

  18. EGFR-TKI therapy for patients with brain metastases from non-small-cell lung cancer: a pooled analysis of published data

    Directory of Open Access Journals (Sweden)

    Fan Y

    2014-11-01

    Full Text Available Yun Fan,1,2 Xiaoling Xu,3 Conghua Xie4 1Zhongnan Hospital of Wuhan University, Department of Radiation Oncology, Wuhan, People's Republic of China; 2Department of Chemotherapy, Zhejiang Cancer Hospital, Hangzhou, People’s Republic of China; 3Zhejiang Cancer Hospital, Hangzhou, People’s Republic of China; 4Zhongnan Hospital of Wuhan University, Department of Radiation Oncology, Wuhan, People’s Republic of China Introduction: Brain metastases are one of the leading causes of death from non-small-cell lung cancer (NSCLC. The use of epidermal growth factor receptor (EGFR tyrosine kinase inhibitors (TKIs to treat brain metastases remains controversial. Thus, we performed a pooled analysis of published data to evaluate the efficacy of EGFR-TKIs in NSCLC patients with brain metastases, particularly for tumors with activating EGFR mutations. Methods: Several data sources were searched, including PubMed, Web of Science, and ASCO Annual Meetings databases. The end points were intracranial overall response rate (ORR, disease control rate (DCR, progression-free survival (PFS, overall survival (OS, and adverse events. The pooled ORR, DCR, PFS, and OS with 95% confidence intervals (CIs were calculated employing fixed- or random-effect models, depending on the heterogeneity of the included studies. Results: Sixteen published studies were included in this analysis, with a total of 464 enrolled patients. The EGFR mutational status was unknown for 362 (unselected group, and 102 had activating EGFR mutations. The pooled intracranial ORR and DCR were 51.8% (95% CI: 45.8%–57.8% and 75.7% (95% CI: 70.3%–80.5%, respectively. A higher ORR was observed in the EGFR mutation group than in the unselected group (85.0% vs 45.1%; a similar trend was observed for the DCR (94.6% vs 71.3%. The pooled median PFS and OS were 7.4 months (95% CI, 4.9–9.9 and 11.9 months (95% CI, 7.7–16.2, respectively, with longer PFS (12.3 months vs 5.9 months and OS (16.2 months vs

  19. EGFR FISH analysis in colorectal cancer as a tool in selecting patients for antiEGFR monoclonal antibodies therapy

    Directory of Open Access Journals (Sweden)

    Mauro Moroni

    2011-12-01

    Full Text Available The recent introduction of targeted therapies in the treatment of patients with metastatic colorectal cancer (mCRC not only improved efficacy but also toxicity and costs of the therapy, therefore requiring the identification of decision-making tools to select patients who are likely to benefit from them. By now, several studies have demonstrated an association between epidermal growth factor receptor (EGFR non-increased gene copy number, evaluated by fluorescence in situ hybridization (FISH, and resistance to the treatment with antiEGFR monoclonal antibodies (moAbs in patients with mCRC. However, the reproducibility of data by standardization of methods still remains an obstacle to be faced for clinical application of the test. We present a review of studies pertaining EGFR FISH analysis as a predictive test of clinical outcome to the treatment with antiEGFR moAbs in mCRC to point out the existing knowledge and the open questions about this issue.

  20. Treatment Choice for Advanced Non-small Cell Lung Cancer Patients Who Had Gradual Progression After EGFR-TKIs: 32 Cases Report

    Directory of Open Access Journals (Sweden)

    Lin LIN

    2013-10-01

    Full Text Available Background and objective The epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs have been widely used in the treatment of the advanced non-small cell lung cancer (NSCLC, especially in the adenocarcinoma patients with activating EGFR mutations. But there is no published overview of the following treatment. This report through observing the efficacy, toxicity and overall survival of different treatments to the advanced NSCLC patients who had gradual progression after EGFR-TKIs, evaluates the influence of the continued treatment and switching chemotherapy. Methods Retrospective review is conducted on 32 cases of advanced NSCLC patients who experienced treatment failure of EGFR-TKIs. One group accepted the continued treatment and the other group accepted the switching chemotherapy. Results The median overall survival of the continued treatment group is 36.0 months. The respose rate of the switching chemotherapy group is 43.75%, and clinical benefit rate (complete and partial response and stable disease is 87.5%. The median overall survival is 15.5 months. The main toxicities are nausea, vomiting and hematological toxicities. Conclusion For the advanced NSCLC patients who had gradual progression after EGFR-TKIs, the continued treatment is one of the acceptable choices.

  1. In vivo evaluation of cetuximab-conjugated poly(γ-glutamic acid)-docetaxel nanomedicines in EGFR-overexpressing gastric cancer xenografts

    Science.gov (United States)

    Sreeranganathan, Maya; Uthaman, Saji; Sarmento, Bruno; Mohan, Chethampadi Gopi; Park, In-Kyu; Jayakumar, Rangasamy

    2017-01-01

    Epidermal growth factor receptor (EGFR), upregulated in gastric cancer patients, is an oncogene of interest in the development of targeted cancer nanomedicines. This study demonstrates in silico modeling of monoclonal antibody cetuximab (CET MAb)-conjugated docetaxel (DOCT)-loaded poly(γ-glutamic acid) (γ-PGA) nanoparticles (Nps) and evaluates the in vitro/in vivo effects on EGFR-overexpressing gastric cancer cells (MKN-28). Nontargeted DOCT-γ-PGA Nps (NT Nps: 110±40 nm) and targeted CET MAb-DOCT-γ-PGA Nps (T Nps: 200±20 nm) were prepared using ionic gelation followed by 1-Ethyl-3-(3-dimethyl aminopropyl)carbodiimide–N-Hydoxysuccinimide (EDC–NSH) chemistry. Increased uptake correlated with enhanced cytotoxicity induced by targeted Nps to EGFR +ve MKN-28 compared with nontargeted Nps as evident from MTT and flow cytometric assays. Nanoformulated DOCT showed a superior pharmacokinetic profile to that of free DOCT in Swiss albino mice, indicating the possibility of improved therapeutic effect in the disease model. Qualitative in vivo imaging showed early and enhanced tumor targeted accumulation of CET MAb-DOCT-γ-PGA Nps in EGFR +ve MKN-28–based gastric cancer xenograft, which exhibited efficient arrest of tumor growth compared with nontargeted Nps and free DOCT. Thus, actively targeted CET MAb-DOCT-γ-PGA Nps could be developed as a substitute to conventional nonspecific chemotherapy, and hence could become a feasible strategy for cancer therapy for EGFR-overexpressing gastric tumors. PMID:29033568

  2. Confirmation of the immunoreactivity of monoclonal anti-human C-terminal EGFR antibodies in bronze Corydoras Corydoras aeneus (Callichthyidae Teleostei) by Western Blot method.

    Science.gov (United States)

    Mytych, Jennifer; Satora, Leszek; Kozioł, Katarzyna

    2017-12-12

    Bronze corydoras (Corydoras aeneus) uses the distal part of the intestine as accessory respiratory organ. Our previous study showed the presence of epidermal growth factor receptor (EGFR) cytoplasmic domain in the digestive tract of the bronze corydoras. In this study, using Western Blot method, we validated the results presented in the previous research. In detail, results of Western Blot analysis on digestive and respiratory part of bronze corydoras intestine homogenates confirmed the immunoreactivity of anti-cytoplasmic domain (C-terminal) human EGFR antibodies with protein band of approximately 180kDa (EGFR molecular weight). This indicates a high homology of EGFR domain between these species and the possibility of such antibody use in bronze corydoras. Statistically significantly higher EGFR expression was observed in the respiratory part of intestine when compared to the digestive part. This implies higher proliferation activity and angiogenesis of epithelium in this part of intestine, creating conditions for air respiration. Therefore, Corydoras aeneus may be considered as a model organism for the molecular studies of the mechanisms of epithelial proliferation initiation and inhibition depending on hypoxia and normoxia. Copyright © 2017. Published by Elsevier GmbH.