WorldWideScience

Sample records for activated egfr determines

  1. Whacking a mole-cule: clinical activity and mechanisms of resistance to third generation EGFR inhibitors in EGFR mutated lung cancers with EGFR-T790M

    Costa, Daniel B.; Kobayashi, Susumu S.

    2015-01-01

    Epidermal growth factor receptor (EGFR) mutations, especially EGFR-exon 19 deletions and EGFR-L858R, are the most frequent actionable genomic events in lung adenocarcinomas. Tumors arise due to constitutively activated EGFR signaling and are susceptible to EGFR tyrosine kinase inhibitors (TKIs). First generation EGFR TKIs (gefitinib and erlotinib) and the second generation EGFR TKI afatinib are approved worldwide. Although targeted therapies against EGFR mutants induce dramatic initial respon...

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

    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. Whacking a mole-cule: clinical activity and mechanisms of resistance to third generation EGFR inhibitors in EGFR mutated lung cancers with EGFR-T790M.

    Costa, Daniel B; Kobayashi, Susumu S

    2015-12-01

    Epidermal growth factor receptor (EGFR) mutations, especially EGFR-exon 19 deletions and EGFR-L858R, are the most frequent actionable genomic events in lung adenocarcinomas. Tumors arise due to constitutively activated EGFR signaling and are susceptible to EGFR tyrosine kinase inhibitors (TKIs). First generation EGFR TKIs (gefitinib and erlotinib) and the second generation EGFR TKI afatinib are approved worldwide. Although targeted therapies against EGFR mutants induce dramatic initial responses, acquired resistance (through multiple biological mechanisms) to erlotinib, gefitinib and afatinib emerges within the first 1-2 years of continued monotherapy. EGFR-T790M accounts for more than half of acquired resistance to first or second generation EGFR TKIs by modifying ATP affinity and drug binding kinetics. Two new studies have shown that two covalent pyrimidine inhibitors-AZD9291 and rociletinib of EGFR-T790M (i.e., third generation EGFR TKIs) shown remarkable clinical activity in patients with acquired resistance to erlotinib, gefitinib and afatinib when the tumor carries EGFR-T790M in conjunction with an activating mutation. However, and regrettably, acquired resistance to these third generation EGFR TKIs has already been reported in preclinical models and clinical specimens; such as a tertiary mutation at EGFR-C797S that prevents covalent binding of EGFR TKIs. The experience with sequential EGFR TKI monotherapy highlights tumor heterogeneity and adaptability (i.e., relentless game of whack-a-mole played between TKIs and cancer), and will help shape future clinical development of novel combinatory approaches to manage EGFR mutated lung adenocarcinomas. PMID:26798593

  4. Direct interaction between surface β1,4-galactosyltransferase 1 and epidermal growth factor receptor (EGFR) inhibits EGFR activation in hepatocellular carcinoma

    Highlights: •β1,4GT1 interacts with EGFR both in vitro and in vivo. •β1,4GT1 co-localizes with EGFR on the cell surface. •β1,4GT1 inhibits 125I-EGF binding to EGFR. •β1,4GT1 inhibits EGF induced EGFR dimerization and phosphorylation. -- Abstract: Our previous studies showed that cell surface β1,4-galactosyltransferase 1 (β1,4GT1) negatively regulated cell survival through inhibition and modulation of the epidermal growth factor receptor (EGFR) signaling pathway in human hepatocellular carcinoma (HCC) SMMC-7721 cells. However, the underlying mechanism remains unclear. Here we demonstrated that β1,4-galactosyltransferase 1 (β1,4GT1) interacted with EGFR in vitro by GST pull-down analysis. Furthermore, we demonstrated that β1,4GT1 bound to EGFR in vivo by co-immunoprecipitation and determined the co-localization of β1,4GT1 and EGFR on the cell surface via confocal laser scanning microscopy analysis. Finally, using 125I-EGF binding experiments and Western blot analysis, we found that overexpression of β1,4GT1 inhibited 125I-EGF binding to EGFR, and consequently reduced the levels of EGFR dimerization and phosphorylation. In contrast, RNAi-mediated knockdown of β1,4GT1 increased the levels of EGFR dimerization and phosphorylation. These data suggest that cell surface β1,4GT1 interacts with EGFR and inhibits EGFR activation

  5. Quantitative Analysis of [11C]-Erlotinib PET Demonstrates Specific Binding for Activating Mutations of the EGFR Kinase Domain

    J. Ryan Petrulli

    2013-12-01

    Full Text Available Activating mutations of the epidermal growth factor receptor (EGFR occur in multiple tumor types, including non-small cell lung cancer (NSCLC and malignant glioma, and have become targets for therapeutic intervention. The determination of EGFR mutation status using a noninvasive, molecular imaging approach has the potential for clinical utility. In this study, we investigated [11C]-erlotinib positron emission tomography (PET imaging as a tool to identify activating mutations of EGFR in both glioma and NSCLC xenografts. Radiotracer specific binding was determined for high and low specific activity (SA [11C]-erlotinib PET scans in mice bearing synchronous human cancer xenografts with different EGFR expression profiles (PC9, HCC827, U87, U87 ΔEGFR, and SW620. Although xenograft immunohistochemistry demonstrated constitutive EGFR phosphorylation, PET scan analysis using the Simplified Reference Tissue Model showed that only kinase domain mutant NSCLC (HCC827 and PC9 had significantly greater binding potentials in high versus low SA scans. Xenografts with undetectable EGFR expression (SW620, possessing wild-type EGFR (U87, and expressing an activating extracellular domain mutation (U87 ΔEGFR were indistinguishable under both high and low SA scan conditions. The results suggest that [11C]-erlotinib is a promising radiotracer that could provide a novel clinical methodology for assessing EGFR and erlotinib interactions in patients with tumors that harbor EGFR-activating kinase domain mutations.

  6. HPV infection and EGFR activation/alteration in HIV-infected East African patients with conjunctival carcinoma.

    Jing Jie Yu

    Full Text Available BACKGROUND: There has been substantial growth in the numbers of patients with conjunctival squamous cell carcinoma infected with HIV in East Africa. The natural history of the conjunctival squamous cell carcinoma appears to be unique in this region of the world, but the etiologic mechanism unclear and therapeutic options limited. This research was carried out to determine if conjunctival squamous cell carcinoma harbors human papillomavirus DNA and is associated with activation of the EGFR signaling pathway. Positive findings would identify etiologic causes and provide clinical guidance to improve treatment. METHODS/FINDINGS: Expression of p-MAPK/MAPK, p-Akt/Akt and p-EGFR/EGFR in cell nuclei and cytoplasm of 38 FFPE specimens were assessed by immunohistochemistry; HPV genotype was detected by qPCR assay; EGFR mutation was assessed by DNA sequencing analysis; and EGFR mRNA expression was measured using relative qPCR. Statistical analyses included two-sided Fisher exact test or chi-square test, Spearman correlation coefficient and ANOVA. HPV 18 was found in 61% of samples, with HPV 16 double-genotype in 6 patients (16%. Immunohistochemistry and qPCR data suggest that activation and expression of the EGFR signaling pathway is related to disease progression of conjunctival cancer. The associations between cytoplasmic p-MAPK, cytoplasmic p-Akt and tumor invasiveness were significant (p = 0.05 or 0.028. Nuclear p-EGFR appeared only in invasive tumors. A significant positive association between EGFR expression and disease invasiveness was observed (p = 0.01. A SNP in 10 patients and one missense mutation were found within EGFR tyrosine kinase domain. Statistical analysis indicates that patients with measurable EGFR expression more likely harbor EGFR mutations, compared to those with negative EGFR expression (35.3% vs. 0%. CONCLUSIONS/SIGNIFICANCE: We conclude that HPV types 16/18 infection is frequent in East African patients with AIDS

  7. Determination of EGFR and KRAS mutational status in Greek non-small-cell lung cancer patients

    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

    2015-01-01

    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 clinicopat...

  8. Inhibition of radiation-induced EGFR nuclear import by C225 (Cetuximab) suppresses DNA-PK activity

    Background and purpose: Inhibition of EGFR-function can induce radiosensitization in tumor cells. Purpose of our investigation was to identify the possible molecular mechanism of radiosensitization following treatment with anti-EGFR-antibody C225 (Cetuximab). Materials and methods: The effect of C225 on radiation response was determined in human cell lines of bronchial carcinoma (A549) and breast adenoma cells (MDA MB 231). The molecular effects of C225 on EGFR-function after irradiation were analyzed applying western blotting, immune-precipitation and kinase assays. Effects on DNA-repair were detected by quantification of γ-H2AX positive foci 24 h after irradiation. Results: The EGFR specific antibody C225 induced radiosensitization in A549 and also in MDA MB 231 cells. Radiosensitization in A549 was associated with blockage of radiation-induced EGFR transport into the nucleus, and immobilized the complex of EGFR with DNA-dependent protein kinase (DNA-PK) in the cytoplasm. As a consequence radiation-induced DNA-PK activation was abolished, a process that is essential for DNA-repair after radiation exposure. Likewise C225 treatment increased the residual amount of γ-H2AX-positive foci 24 h after irradiation in A549 and in MDA MB 231 cells. Conclusions: Our results suggest that irradiation induced DNA-PK activation-essential for DNA repair-may be hampered specifically by use of the anti-EGFR-antibody C225. This process is associated with radiosensitization

  9. Integrated Experimental and Model-based Analysis Reveals the Spatial Aspects of EGFR Activation Dynamics

    Shankaran, Harish; Zhang, Yi; Chrisler, William B.; Ewald, Jonathan A.; Wiley, H. S.; Resat, Haluk

    2012-10-02

    The epidermal growth factor receptor (EGFR) belongs to the ErbB family of receptor tyrosine kinases, and controls a diverse set of cellular responses relevant to development and tumorigenesis. ErbB activation is a complex process involving receptor-ligand binding, receptor dimerization, phosphorylation, and trafficking (internalization, recycling and degradation), which together dictate the spatio-temporal distribution of active receptors within the cell. The ability to predict this distribution, and elucidation of the factors regulating it, would help to establish a mechanistic link between ErbB expression levels and the cellular response. Towards this end, we constructed mathematical models for deconvolving the contributions of receptor dimerization and phosphorylation to EGFR activation, and to examine the dependence of these processes on sub-cellular location. We collected experimental datasets for EGFR activation dynamics in human mammary epithelial cells, with the specific goal of model parameterization, and used the data to estimate parameters for several alternate models. Model-based analysis indicated that: 1) signal termination via receptor dephosphorylation in late endosomes, prior to degradation, is an important component of the response, 2) less than 40% of the receptors in the cell are phosphorylated at any given time, even at saturating ligand doses, and 3) receptor dephosphorylation rates at the cell surface and early endosomes are comparable. We validated the last finding by measuring EGFR dephosphorylation rates at various times following ligand addition both in whole cells, and in endosomes using ELISAs and fluorescent imaging. Overall, our results provide important information on how EGFR phosphorylation levels are regulated within cells. Further, the mathematical model described here can be extended to determine receptor dimer abundances in cells co-expressing various levels of ErbB receptors. This study demonstrates that an iterative cycle of

  10. Selective Antitumor Activity of Ibrutinib in EGFR-Mutant Non–Small Cell Lung Cancer Cells

    Gao, Wen; Wang, Michael; Wang, Li; Lu, Haibo; Wu, Shuhong; Dai, Bingbing; Ou, Zhishuo; Zhang, Liang; Heymach, John V.; Gold, Kathryn A.; Minna, John ,; Roth, Jack A.; Hofstetter, Wayne L.; Swisher, Stephen G.; Fang, Bingliang

    2014-01-01

    Ibrutinib, which irreversibly inhibits Bruton tyrosine kinase, was evaluated for antitumor activity in a panel of non–small cell lung cancer (NSCLC) cell lines and found to selectively inhibit growth of NSCLC cells carrying mutations in the epidermal growth factor receptor (EGFR) gene, including T790M mutant and erlotinib-resistant H1975 cells. Ibrutinib induced dose-dependent inhibition of phosphor-EGFR at both Y1068 and Y1173 sites, suggesting ibrutinib functions as an EGFR inhibitor. Survi...

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

    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.

  12. EGFR-activating mutations, DNA copy number abundance of ErbB family, and prognosis in lung adenocarcinoma

    Chen, Hsuan-Yu; Liu, Chia-Hsin; Chang, Ya-Hsuan; Yu, Sung-Liang; Ho, Bing-Ching; Hsu, Chung-Ping; Yang, Tsung-Ying; Chen, Kun-Chieh; Hsu, Kuo-Hsuan; Tseng, Jeng-Sen; Hsia, Jiun-Yi; Chuang, Cheng-Yen; Chang, Chi-Sheng; Li, Yu-Cheng; Li, Ker-Chau; Chang, Gee-Chen; Yang, Pan-Chyr

    2016-01-01

    In this study, EGFR-activating mutation status and DNA copy number abundances of members of ErbB family were measured in 261 lung adenocarcinomas. The associations between DNA copy number abundances of ErbB family, EGFR-activating mutation status, and prognosis were explored. Results showed that DNA copy number abundances of EGFR, ERBB2, ERBB3, and ERBB4 had associations with overall survival in lung adenocarcinoma with EGFR-activating mutations. In the stratification analysis, only ERBB2 showed significant discrepancy in patients carrying wild type EGFR and other members of ErbB family in patients carrying EGFR-activating mutation. This indicated that CNAs of ErbB family had effect modifications of EGFR-activating mutation status. Findings of this study demonstrate potential molecular guidance of patient management of lung adenocarcinoma with or without EGFR-activating mutations. PMID:26824984

  13. TGFβ induces proHB-EGF shedding and EGFR transactivation through ADAM activation in gastric cancer cells

    Research highlights: → TGFβ induces EGFR transactivation through proHB-EGF shedding by activated ADAM members in gastric cancer cells. → TGFβ induces nuclear translocation of HB-EGF-CTF cleaved by ADAM members. → TGFβ enhances cell growth by EGFR transactivation and HB-EGF-CTF nuclear translocation and ADAM inhibitors block these effects. → Silencing of ADAM17 also blocks EGFR transactivation, HB-EGF-CTF nuclear translocation and cancer cell growth by TGFβ. → ADAM17 may play a crucial role in this TGFβ-HB-EGF signal transduction. -- Abstract: Background and aims: Transforming growth factor-beta (TGFβ) is known to potently inhibit cell growth. Loss of responsiveness to TGFβ inhibition on cell growth is a hallmark of many types of cancer, yet its mechanism is not fully understood. Membrane-anchored heparin-binding EGF-like growth factor (proHB-EGF) ectodomain is cleaved by a disintegrin and metalloproteinase (ADAM) members and is implicated in epidermal growth factor receptor (EGFR) transactivation. Recently, nuclear translocation of the C-terminal fragment (CTF) of pro-HB-EGF was found to induce cell growth. We investigated the association between TGFβ and HB-EGF signal transduction via ADAM activation. Materials and methods: The CCK-8 assay in two gastric cancer cell lines was used to determine the effect for cell growth by TGFβ. The effect of two ADAM inhibitors was also evaluated. Induction of EGFR phosphorylation by TGFβ was analyzed and the effect of the ADAM inhibitors was also examined. Nuclear translocation of HB-EGF-CTF by shedding through ADAM activated by TGFβ was also analyzed. EGFR transactivation, HB-EGF-CTF nuclear translocation, and cell growth were examined under the condition of ADAM17 knockdown. Result: TGFβ-induced EGFR phosphorylation of which ADAM inhibitors were able to inhibit. TGFβ induced shedding of proHB-EGF allowing HB-EGF-CTF to translocate to the nucleus. ADAM inhibitors blocked this nuclear translocation. TGF

  14. Akt kinase-interacting protein1, a novel therapeutic target for lung cancer with EGFR-activating and gatekeeper mutations.

    Yamada, T; Takeuchi, S; Fujita, N; Nakamura, A; Wang, W; Li, Q; Oda, M; Mitsudomi, T; Yatabe, Y; Sekido, Y; Yoshida, J; Higashiyama, M; Noguchi, M; Uehara, H; Nishioka, Y; Sone, S; Yano, S

    2013-09-12

    Despite initial dramatic response, epidermal growth factor receptor (EGFR) mutant lung cancer patients always acquire resistance to EGFR-tyrosine kinase inhibitors (TKIs). Gatekeeper T790M mutation in EGFR is the most prevalent genetic alteration underlying acquired resistance to EGFR-TKI, and EGFR mutant lung cancer cells are reported to be addictive to EGFR/Akt signaling even after acquired T790M mutation. Here, we focused on Akt kinase-interacting protein1 (Aki1), a scaffold protein of PI3K (phosphoinositide 3-kinase)/PDK1 (3-phosphoinositide-dependent protein kinase)/Akt that determines receptor signal selectivity for non-mutated EGFR, and assessed its role in EGFR mutant lung cancer with or without gatekeeper T790M mutation. Cell line-based assays showed that Aki1 constitutively associates with mutant EGFR in lung cancer cells with (H1975) or without (PC-9 and HCC827) T790M gatekeeper mutation. Silencing of Aki1 induced apoptosis of EGFR mutant lung cancer cells. Treatment with Aki1 siRNA dramatically inhibited growth of H1975 cells in a xenograft model. Moreover, silencing of Aki1 further potentiated growth inhibitory effect of new generation EGFR-TKIs against H1975 cells in vitro. Aki1 was frequently expressed in tumor cells of EGFR mutant lung cancer patients (53/56 cases), including those with acquired resistance to EGFR-TKI treatment (7/7 cases). Our data suggest that Aki1 may be a critical mediator of survival signaling from mutant EGFR to Akt, and may therefore be an ideal target for EGFR mutant lung cancer patients, especially those with acquired EGFR-TKI resistance due to EGFR T790M gatekeeper mutation. PMID:23045273

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

    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 (FCMTGF, FCMPDGF) were used to stimulate PE/CA-PJ15 OSCC cells. Results were compared to the effect of conditioned media of non-stimulated fibroblasts (FCMB). FCMTGF stimulation leads to an up-regulation of vimentin in the OSCC cells and an enhancement of invasive behaviour, indicating EMT-like effects. Similarly, FCMTGF≫FCMPDGF 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 (FCMTGF>FCMPDGF) 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 as sign of EMT. • Results qualify CAF as

  16. Cell adhesion and EGFR activation regulate EphA2 expression in cancer

    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...

  17. Antagonistic regulation of swelling-activated Cl− current in rabbit ventricle by Src and EGFR protein tyrosine kinases

    Ren, Zuojun; Baumgarten, Clive M.

    2005-01-01

    Regulation of swelling-activated Cl− current (ICl,swell) is complex, and multiple signaling cascades are implicated. To determine whether protein tyrosine kinase (PTK) modulates ICl,swell and to identify the PTK involved, we studied the effects of a broad-spectrum PTK inhibitor (genistein), selective inhibitors of Src (PP2, a pyrazolopyrimidine) and epidermal growth factor receptor (EGFR) kinase (PD-153035), and a protein tyrosine phosphatase (PTP) inhibitor (orthovanadate). ICl,swell evoked ...

  18. Anti-epidermal growth factor receptor monoclonal antibody cetuximab inhibits EGFR/HER-2 heterodimerization and activation.

    Patel, Dipa; Bassi, Rajiv; Hooper, Andrea; Prewett, Marie; Hicklin, Daniel J; Kang, Xiaoqiang

    2009-01-01

    Human carcinomas frequently express one or more members of the epidermal growth factor receptor family. Two family members, epidermal growth factor receptor (EGFR) and c-erbB2/neu (HER2), homodimerize or heterodimerize upon activation with ligand and trigger potent mechanisms of cellular proliferation, differentiation and migration. In this study, we examined the effect of the anti-EGFR monoclonal antibody Erbitux (cetuximab) on human tumor cells expressing both EGFR and HER2. Investigation of the effect of cetuximab on the activation of EGFR-EGFR, EGFR-HER2 and HER2-HER2 homodimers and heterodimers was conducted using the NCI-N87 human gastric carcinoma cell line. Treatment of NCI-N87 cells with cetuximab completely inhibited formation of EGFR-EGFR homodimers and EGFR-HER2 heterodimers. Activation of HER2-HER2 homodimers was not appreciably stimulated by exogenous ligand and was not inhibited by cetuximab treatment. Furthermore, cetuximab inhibited EGF-induced EGFR and HER2 phosphorylation in CAL27, NCI-H226 and NCI-N87 cells. The activation of downstream signaling molecules such as AKT, MAPK and STAT-3 were also inhibited by cetuximab in these cells. To examine the effect of cetuximab on the growth of tumors in vivo, athymic mice bearing established NCI-N87 or CAL27 xenografts were treated with cetuximab (1 mg, i.p., q3d). The growth of NCI-N87 and CAL27 tumors was significantly inhibited with cetuximab therapy compared to the control groups (p<0.0001 in both cases). In the CAL27 xenograft model, tumor growth inhibition by cetuximab treatment was similar to that by cetuximab and trastuzumab combination treatment. Immunohistological analysis of cetuximab-treated tumors showed a decrease in EGFR-HER2 signaling and reduced tumor cell proliferation. These results suggest that cetuximab may be useful in the treatment of carcinomas co-expressing EGFR and HER2. PMID:19082474

  19. K-RAS(V12) Induces Autocrine Production of EGFR Ligands and Mediates Radioresistance Through EGFR-Dependent Akt Signaling and Activation of DNA-PKcs

    Purpose: It is known that postirradiation survival of tumor cells presenting mutated K-RAS is mediated through autocrine activation of epidermal growth factor receptor (EGFR). In this study the molecular mechanism of radioresistance of cells overexpressing mutated K-RAS(V12) was investigated. Methods and Materials: Head-and-neck cancer cells (FaDu) presenting wild-type K-RAS were transfected with empty vector or vector expressing mutated K-RAS(V12). The effect of K-RAS(V12) on autocrine production of EGFR ligands, activation of EGFR downstream pathways, DNA damage repair, and postirradiation survival was analyzed. Results: Conditioned medium collected from K-RAS(V12)–transfected cells enhanced activation of the phosphatidylinositol-3-kinase–Akt pathway and increased postirradiation survival of wild-type K-RAS parental cells when compared with controls. These effects were reversed by amphiregulin (AREG)–neutralizing antibody. In addition, secretion of the EGFR ligands AREG and transforming growth factor α was significantly increased upon overexpression of K-RAS(V12). Expression of mutated K-RAS(V12) resulted in an increase in radiation-induced DNA-dependent protein kinase catalytic subunit (DNA-PKcs) phosphorylation at S2056. This increase was accompanied by increased repair of DNA double-strand breaks. Abrogation of DNA-PKcs phosphorylation by serum depletion or AREG-neutralizing antibody underscored the role of autocrine production of EGFR ligands, namely, AREG, in regulating DNA-PKcs activation in K-RAS mutated cells. Conclusions: These data indicate that radioresistance of K-RAS mutated tumor cells is at least in part due to constitutive production of EGFR ligands, which mediate enhanced repair of DNA double-strand breaks through the EGFR–phosphatidylinositol-3-kinase–Akt cascade.

  20. Mechanisms of silica-induced IL-8 release from A549 cells: Initial kinase-activation does not require EGFR activation or particle uptake

    Understanding how mineral particles trigger cellular responses is crucial in order to elucidate what characteristics determine their harmful effects. It is not clear whether cellular effects are triggered through the cell membrane or require particle uptake. However, studies with asbestos suggest that activation of the epidermal growth factor receptor (EGFR) may be important. We have previously reported that crystalline silica-induced interleukin (IL)-8 release from human lung epithelial cells (A549) was regulated through Src family kinases (SFKs) and the mitogen-activated protein kinases (MAPKs) p38 and extracellular signal-regulated kinase (ERK)-1 and -2. The present study shows that SFK and p38 phosphorylation increased almost immediately upon crystalline silica exposure, whereas ERK1/2 phosphorylation increased after 10 min of exposure. The p38 inhibitor SB202190 increased the silica-induced ERK1/2 phosphorylation suggesting that p38 activity may attenuate activation of ERK1/2. Scanning electron microscopy showed that some silica particles were phagocytosed between 1 and 4 h of exposure, but that the majority remained bound by microvilli on the cell surface. The EGFR inhibitor AG1478 attenuated both silica-induced IL-8 release and phosphorylation of SFKs and ERK1/2. However, AG1478 also inhibited the respective background levels, and the EGFR was not phosphorylated at the onset of silica exposure. The results suggest that crystalline silica triggers p38 and SFK-ERK1/2 signaling through interactions with membrane components as both pathways were rapidly activated prior to particle internalization. However, the silica-induced up-regulation of IL-8 release through the SFK-ERK1/2 pathway does not appear to be initiated through activation of the EGFR, although basal EGFR activity may affect the magnitude of the responses

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

    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.

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

    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

  3. Activation of Multiple ERBB Family Receptors Mediates Glioblastoma Cancer Stem-like Cell Resistance to EGFR-Targeted Inhibition

    Paul A. Clark

    2012-05-01

    Full Text Available Epidermal growth factor receptor (EGFR signaling is strongly implicated in glioblastoma (GBM tumorigenesis. However, molecular agents targeting EGFR have demonstrated minimal efficacy in clinical trials, suggesting the existence of GBM resistance mechanisms. GBM cells with stem-like properties (CSCs are highly efficient at tumor initiation and exhibit therapeutic resistance. In this study, GBMCSC lines showed sphere-forming and tumor initiation capacity after EGF withdrawal from cell culture media, compared with normal neural stem cells that rapidly perished after EGF withdrawal. Compensatory activation of related ERBB family receptors (ERBB2 and ERBB3 was observed in GBM CSCs deprived of EGFR signal (EGF deprivation or cetuximab inhibition, suggesting an intrinsic GBM resistance mechanism for EGFR-targeted therapy. Dual inhibition of EGFR and ERBB2 with lapatinib significantly reduced GBM proliferation in colony formation assays compared to cetuximab-mediated EGFR-specific inhibition. Phosphorylation of downstream ERBB signaling components (AKT, ERK1/2 and GBM CSC proliferation were inhibited by lapatinib. Collectively, these findings show that GBM therapeutic resistance to EGFR inhibitors may be explained by compensatory activation of EGFR-related family members (ERBB2, ERBB3 enabling GBM CSC proliferation, and therefore simultaneous blockade of multiple ERBB family members may be required for more efficacious GBM therapy.

  4. Model-based analysis of HER activation in cells co-expressing EGFR, HER2 and HER3.

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

    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 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/HER1, 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 human mammary epithelial cells lines with known HER expression levels in response to stimulations with ligands EGF and HRG. Simulations over the range of expression levels seen in various cell lines indicate that: i) EGFR phosphorylation is driven by HER1-HER1 and HER1-HER2 dimers, and not HER1-HER3 dimers, ii) HER1-HER2 and HER2-HER3 dimers both contribute significantly to HER2 activation with the EGFR expression level determining the relative importance of these species, and iii) the HER2-HER3 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. PMID:23990774

  5. Model-based analysis of HER activation in cells co-expressing EGFR, HER2 and HER3.

    Harish Shankaran

    Full Text Available 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 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/HER1, 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 human mammary epithelial cells lines with known HER expression levels in response to stimulations with ligands EGF and HRG. Simulations over the range of expression levels seen in various cell lines indicate that: i EGFR phosphorylation is driven by HER1-HER1 and HER1-HER2 dimers, and not HER1-HER3 dimers, ii HER1-HER2 and HER2-HER3 dimers both contribute significantly to HER2 activation with the EGFR expression level determining the relative importance of these species, and iii the HER2-HER3 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.

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

    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.

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

    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.

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

    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. 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). 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. 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

  9. NF-κB signaling is activated and confers resistance to apoptosis in three-dimensionally cultured EGFR-mutant lung adenocarcinoma cells

    Highlights: ► EGFR-mutant cells in 3D culture resist EGFR inhibition compared with suspended cells. ► Degradation of IκB and activation of NF-κB are observed in 3D-cultured cells. ► Inhibiting NF-κB enhances the efficacy of the EGFR inhibitor in 3D-cultured cells. -- Abstract: Epidermal growth factor receptor (EGFR)-mutant lung adenocarcinoma cells in suspension undergo apoptosis to a greater extent than adherent cells in a monolayer when EGFR autophosphorylation is inhibited by EGFR tyrosine kinase inhibitors (TKIs). This suggests that cell adhesion to a culture dish may activate an anti-apoptotic signaling pathway other than the EGFR pathway. Since the microenvironment of cells cultured in a monolayer are substantially different to that of cells existing in three-dimension (3D) in vivo, we assessed whether two EGFR-mutant lung adenocarcinoma cell lines, HCC827 and H1975, were more resistant to EGFR TKI-induced apoptosis when cultured in a 3D extracellular matrix (ECM) as compared with in suspension. The ECM-adherent EGFR-mutant cells in 3D were significantly less sensitive to treatment with WZ4002, an EGFR TKI, than the suspended cells. Further, a marked degradation of IκBα, the inhibitor of nuclear factor (NF)-κB, was observed only in the 3D-cultured cells, leading to an increase in the activation of NF-κB. Moreover, the inhibition of NF-κB with pharmacological inhibitors enhanced EGFR TKI-induced apoptosis in 3D-cultured EGFR-mutant cells. These results suggest that inhibition of NF-κB signaling would render ECM-adherent EGFR-mutant lung adenocarcinoma cells in vivo more susceptible to EGFR TKI-induced cell death.

  10. HDAC6-mediated EGFR stabilization and activation restrict cell response to sorafenib in non-small cell lung cancer cells.

    Wang, Zhihao; Hu, Pengchao; Tang, Fang; Xie, Conghua

    2016-05-01

    Sorafenib is a multi-targeted kinase inhibitor and has been the subject of extensive clinical research in advanced non-small cell lung cancer (NSCLC). However, sorafenib fails to improve overall survival of patients with advanced NSCLC. The molecular mechanisms that account for this phenomenon are unclear. Here we show that sorafenib treatment stabilizes epidermal growth factor receptor (EGFR) and activates EGFR pathway. Moreover, this is partly mediated by stabilization of histone deacetylase 6 (HDAC6), which has been shown to regulate EGFR endocytic trafficking and degradation. Overexpression of HDAC6 confers resistance to sorafenib in NSCLC cells. Inhibition of HDAC6 with selective inhibitors synergizes with sorafenib to kill NSCLC cells via inhibition of sorafenib-mediated EGFR pathway activation. Taken together, our findings might partly explain the failure of Phase III trial of sorafenib in improving overall survival of advanced NSCLC patients and bear possible implications for the improvement on the efficacy of sorafenib in treatment of NSCLC. PMID:27090797

  11. ZD6474, an inhibitor of VEGFR and EGFR tyrosine kinase activity in combination with radiotherapy

    Radiation enhances both epithelial growth factor receptor (EGFR) and vascular endothelial growth factor (VEGF) expression, which are a part of key pathways for tumor progression. Some tumors may not respond well to EGFR inhibitors alone or may develop resistance to EGFR inhibitors. Therefore, drug therapy targeted to VEGF receptors and EGFRs, when combined with radiotherapy (RT), may improve tumor control and provide wider applicability. This article focuses on ZD6474, an inhibitor of EGFR and VEGF receptor signaling in combination with RT. We discuss preclinical and clinical studies with RT and inhibitors of VEGF or EGFR signaling first. We then address issues associated with ZD6474 pharmacokinetic dosing, and scheduling when combined with RT. We also discuss ZD6474 in the context of anti-EGFR therapy resistance. Dual inhibition of EGFR and VEGF receptor signaling pathways shows promise in enhancing RT efficacy

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

    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.......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....

  13. Synthesis, Characterization, and in Vitro Antitumor Activity of Ruthenium(II) Polypyridyl Complexes Tethering EGFR-Inhibiting 4-Anilinoquinazolines.

    Du, Jun; Kang, Yan; Zhao, Yao; Zheng, Wei; Zhang, Yang; Lin, Yu; Wang, Zhaoying; Wang, Yuanyuan; Luo, Qun; Wu, Kui; Wang, Fuyi

    2016-05-01

    Ruthenium-based anticancer complexes are promising antitumor agents for their low system toxicity and versatile chemical structures. Epidermal growth factor receptor (EGFR) has been found to be overexpressed in a broad range of tumor cells and is regarded as a drug target in developing novel antitumor drugs. In this work, five ruthenium(II) polypyridyl complexes containing EGFR-inhibiting 4-anilinoquinazoline pharmacophores were synthesized and characterized. These complexes showed both high EGFR-inhibiting activity and strong DNA minor groove-binding activity. In vitro antiproliferation screening demonstrated that the prepared ruthenium complexes are highly cytotoxic against a series of cancer cell lines, in particular non-small-cell lung A549 and human epidermoid carcinoma A431. Fluorescence-activated cell sorting analysis and fluorescence microscopy revealed that the most active complex, K4, induced much more late-stage cell apoptosis and necrosis than gefitinib, the first EGFR-targeting antitumor drug in clinical use. These results indicate that the ruthenium(II) polypyridyl complexes bearing EGFR-inhibiting 4-anilinoquinazolines possess highly active dual-targeting anticancer activity and are promising in developing new anticancer agents. PMID:27093574

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

    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.

  15. CRIPTO1 expression in EGFR-mutant NSCLC elicits intrinsic EGFR-inhibitor resistance

    Park, Kang-Seo; Raffeld, Mark; Moon, Yong Wha; Xi, Liqiang; Bianco, Caterina; Van Pham, Trung; Lee, Liam C.; Mitsudomi, Tetsuya; Yatabe, Yasushi; Okamoto, Isamu; Subramaniam, Deepa; Mok, Tony; Rosell, Rafael; Luo, Ji; Salomon, David S.

    2014-01-01

    The majority of non–small cell lung cancer (NSCLC) patients harbor EGFR-activating mutations that can be therapeutically targeted by EGFR tyrosine kinase inhibitors (EGFR-TKI), such as erlotinib and gefitinib. Unfortunately, a subset of patients with EGFR mutations are refractory to EGFR-TKIs. Resistance to EGFR inhibitors reportedly involves SRC activation and induction of epithelial-to-mesenchymal transition (EMT). Here, we have demonstrated that overexpression of CRIPTO1, an EGF-CFC protei...

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

    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.

  17. Synthesis of new 4-anilinoquinazoline analogues and evaluation of their EGFR inhibitor activity.

    Wang, Zheng; WANG, Cui-Ling; Li, Jun-lin; Zhang, Ning; Sun, Yan-ni; Liu, Zhu-lan; Tang, Zhi-shu; Liu, Jian-li

    2015-12-01

    Thirteen of 4-anilinoquinazoline derivatives with imine groups at position 6 of quinazoline ring were synthesized and their antitumor activities were evaluated by MTT assay and Western blotting analysis. Among these compounds, 13a-131 were reported first time. The MTT assay was carried out on three human cancer cell lines (A549, HepG2 and SMMC7721) with EGFR highly expressed. Among the tested compounds, 13i and 13j exhibited notable inhibition potency and their IC50 values on three cell lines were equivalent to or less than those of gefitinib. Compound 14, without imine group substituted, displayed excellent inhibitor potency only on A549 cell line. Compounds 14 and 13j were chosen to perform Western blotting analysis on A549. The results showed that both of the compounds could inhibit the expression level of phosphorylated EGFR remarkably. It was concluded that the inhibitor potency of compound 14 was almost equivalent to that of gefitinib and the inhibitor potency of 13j was better than that of gefitinib. PMID:27169285

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

    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. PMID:27086143

  19. Clinical activity of the mutant-selective EGFR inhibitor AZD9291 in patients with EGFR inhibitor—resistant non-small cell lung cancer

    Tao JIANG; Caicun ZHOU

    2014-01-01

    The first generation epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) are effective in advanced non-small cell lung cancer (NSCLC) with EGFR mutations. Unfortunately, disease progression generally occurs after 9 to 14 months of targeted therapy. The substitution of threonine with methionine at amino acid position 790 (T790M), as the second mutation in EGFR, is the most common resistance mechanism and is detected in tumor cells from more than 50-60% of patients after dis...

  20. Clinical activity of the mutant-selective EGFR inhibitor AZD9291 in patients with EGFR inhibitor-resistant non-small cell lung cancer.

    Jiang, Tao; Zhou, Caicun

    2014-12-01

    The first generation epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) are effective in advanced non-small cell lung cancer (NSCLC) with EGFR mutations. Unfortunately, disease progression generally occurs after 9 to 14 months of targeted therapy. The substitution of threonine with methionine at amino acid position 790 (T790M), as the second mutation in EGFR, is the most common resistance mechanism and is detected in tumor cells from more than 50-60% of patients after disease progression. However, current targeted therapeutic strategies for patients with acquired resistance are limited. This has led to the development of "third generation" EGFR-TKIs that are designed to target T790M and EGFR-TKI sensitizing mutations more selectively than wild-type. AZD9291, as a mono-anilino-pyrimidine compound, is a novel, irreversible EGFR-TKI, has proved to be more effective against both EGFR-TKI sensitizing and resistance T790M mutations in preclinical models. This phase I clinical study showed that AZD9291 has robust efficacy and is well tolerated in EGFR mutant NSCLC patients with acquired resistance to EGFR-TKIs. PMID:25806323

  1. Hierarchical modeling of activation mechanisms in the ABL and EGFR kinase domains: thermodynamic and mechanistic catalysts of kinase activation by cancer mutations.

    Anshuman Dixit

    2009-08-01

    Full Text Available Structural and functional studies of the ABL and EGFR kinase domains have recently suggested a common mechanism of activation by cancer-causing mutations. However, dynamics and mechanistic aspects of kinase activation by cancer mutations that stimulate conformational transitions and thermodynamic stabilization of the constitutively active kinase form remain elusive. We present a large-scale computational investigation of activation mechanisms in the ABL and EGFR kinase domains by a panel of clinically important cancer mutants ABL-T315I, ABL-L387M, EGFR-T790M, and EGFR-L858R. We have also simulated the activating effect of the gatekeeper mutation on conformational dynamics and allosteric interactions in functional states of the ABL-SH2-SH3 regulatory complexes. A comprehensive analysis was conducted using a hierarchy of computational approaches that included homology modeling, molecular dynamics simulations, protein stability analysis, targeted molecular dynamics, and molecular docking. Collectively, the results of this study have revealed thermodynamic and mechanistic catalysts of kinase activation by major cancer-causing mutations in the ABL and EGFR kinase domains. By using multiple crystallographic states of ABL and EGFR, computer simulations have allowed one to map dynamics of conformational fluctuations and transitions in the normal (wild-type and oncogenic kinase forms. A proposed multi-stage mechanistic model of activation involves a series of cooperative transitions between different conformational states, including assembly of the hydrophobic spine, the formation of the Src-like intermediate structure, and a cooperative breakage and formation of characteristic salt bridges, which signify transition to the active kinase form. We suggest that molecular mechanisms of activation by cancer mutations could mimic the activation process of the normal kinase, yet exploiting conserved structural catalysts to accelerate a conformational transition

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

    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.

  3. Conversion from the "oncogene addiction" to "drug addiction" by intensive inhibition of the EGFR and MET in lung cancer with activating EGFR mutation.

    Suda, Kenichi; Tomizawa, Kenji; Osada, Hirotaka; Maehara, Yoshihiko; Yatabe, Yasushi; Sekido, Yoshitaka; Mitsudomi, Tetsuya

    2012-06-01

    Emergence of acquired resistance is virtually inevitable in patients with a mutation in the epidermal growth factor receptor gene (EGFR) treated with EGFR tyrosine kinase inhibitors (TKIs). Several novel TKIs that may prevent or overcome the resistance mechanisms are now under clinical development. However, it is unknown how tumor cells will respond to intensive treatment using these novel TKIs. We previously established HCC827EPR cells, which are T790M positive, through combined treatment with erlotinib and a MET-TKI from erlotinib-hypersensitive HCC827 cells. In this study, we treated HCC827EPR cells sequentially with an irreversible EGFR-TKI, CL-387,785, to establish resistant cells (HCC827CLR), and we analyzed the mechanisms responsible for resistance. In HCC827CLR cells, PTEN expression was downregulated and Akt phosphorylation persisted in the presence of CL-387,785. Akt inhibition restored CL-387,785 sensitivity. In addition, withdrawal of CL-387,785 reduced cell viability in HCC827CLR cells, indicating that these cells were "addicted" to CL-387,785. HCC827CLR cells overexpressed the EGFR, and inhibition of the EGFR or MEK-ERK was needed to maintain cell proliferation. Increased senescence was observed in HCC827CLR cells in the drug-free condition. Through long-term culture of HCC827CLR cells without CL-387,785, we established HCC827-CL-387,785-independent cells, which exhibited decreased EGFR expression and a mesenchymal phenotype. In conclusion, PTEN downregulation is a newly identified mechanism underlying the acquired resistance to irreversible EGFR-TKIs after acquisition of T790M against erlotinib. This series of experiments highlights the flexibility of cancer cells that have adapted to environmental stresses induced by intensive treatment with TKIs. PMID:22133747

  4. The use of EGFR exon 19 and 21 unlabeled DNA probes to screen for activating mutations in non-small cell lung cancer.

    Willmore-Payne, Carlynn; Holden, Joseph A; Wittwer, Carl T; Layfield, Lester J

    2008-07-01

    Activating mutations in epidermal growth factor receptor-1 (EGFR) are found in 10-15% of Caucasian patients with non-small cell lung carcinoma (NSCLC). Approximately 90% of the mutations are deletions of several amino acids in exon 19 or point mutations in exon 21. Some studies suggest that these mutations identify patients that might benefit from targeted EGFR inhibitor therapy. DNA melting analysis of polymerase chain reaction products can screen for these mutations to identify this patient population. However, amplicon DNA melting analysis, although easily capable of detecting heterozygous mutations by heterodimer formation, becomes more difficult if mutations are homozygous or if the mutant allele is selectively amplified over wild type. Amplification of EGFR is common in NSCLC and this could compromise mutation detection by amplicon melting analysis. To overcome this potential limitation, we developed unlabeled, single-stranded DNA probes, complimentary to EGFR exon 19 and exon 21 where the common activating mutations occur. The unlabeled probes are incorporated into a standard polymerase chain reaction during the amplification of EGFR exons 19 and 21. The probe melting peak is easily distinguished from the amplicon melting peak, and probe melting is altered if mutations are present. This allows for easy identification of activating mutations even in homozygous or amplified states and is useful in the screening of NSCLC for the common EGFR activating mutations. PMID:19137110

  5. Elevated Expression of Fn14 in Non-Small Cell Lung Cancer Correlates with Activated EGFR and Promotes Tumor Cell Migration and Invasion

    Whitsett, Timothy G.; Cheng, Emily; Inge, Landon; Asrani, Kaushal; Jameson, Nathan M.; Hostetter, Galen; Weiss, Glen J.; Kingsley, Christopher B.; Loftus, Joseph C.; Bremner, Ross; Tran, Nhan L.; Winkles, Jeffrey A.

    2012-01-01

    Lung cancer is the leading cause of cancer deaths worldwide; approximately 85% of these cancers are non-small cell lung cancer (NSCLC). Patients with NSCLC frequently have tumors harboring somatic mutations in the epidermal growth factor receptor (EGFR) gene that cause constitutive receptor activation. These patients have the best clinical response to EGFR tyrosine kinase inhibitors (TKIs). Herein, we show that fibroblast growth factor–inducible 14 (Fn14; TNFRSF12A) is frequently overexpresse...

  6. The Use of EGFR Exon 19 and 21 Unlabeled DNA Probes to Screen for Activating Mutations in Non–Small Cell Lung Cancer

    Willmore-Payne, Carlynn; Holden, Joseph A.; Wittwer, Carl T.; Layfield, Lester J.

    2008-01-01

    Activating mutations in epidermal growth factor receptor-1 (EGFR) are found in 10–15% of Caucasian patients with non–small cell lung carcinoma (NSCLC). Approximately 90% of the mutations are deletions of several amino acids in exon 19 or point mutations in exon 21. Some studies suggest that these mutations identify patients that might benefit from targeted EGFR inhibitor therapy. DNA melting analysis of polymerase chain reaction products can screen for these mutations to identify this patient...

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

    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.

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

    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

  9. Akt kinase-interacting protein1, a novel therapeutic target for lung cancer with EGFR-activating and gatekeeper mutations

    Yamada, Tadaaki; Takeuchi, Shinji; Fujita, Naoya; Nakamura, Akito; Wang, Wei; Li, Qi; Oda, Makoto; Mitsudomi, Tetsuya; Yatabe, Yasushi; Sekido, Yoshitaka; Yoshida, Junji; Higashiyama, Masahiko; Noguchi, Masayuki; Uehara, Hisanori; Nishioka, Yasuhiko

    2013-01-01

    Despite initial dramatic response, epidermal growth factor receptor (EGFR) mutant lung cancer patients always acquire resistance to EGFR-tyrosine kinase inhibitors (TKIs). Gatekeeper T790M mutation in EGFR is the most prevalent genetic alteration underlying acquired resistance to EGFR-TKI, and EGFR mutant lung cancer cells are reported to be addictive to EGFR/Akt signaling even after acquired T790M mutation. Here, we focused on Akt kinase-interacting protein1 (Aki1), a scaffold protein of PI3...

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

    Frogne, Thomas; Benjaminsen, Rikke V; Sonne-Hansen, Katrine; Sorensen, Boe S; Nexo, Ebba; Laenkholm, Anne-Vibeke; Rasmussen, Louise M; Riese, David J; de Cremoux, Patricia; Stenvang, Jan; Lykkesfeldt, Anne

    2008-01-01

    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...... 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....... Our data support that a concerted action against EGFR, ErbB2 and ErbB3 may be required to obtain complete growth suppression of fulvestrant resistant cells....

  11. 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

    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.

  12. 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

    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

  13. CRIPTO1 expression in EGFR-mutant NSCLC elicits intrinsic EGFR-inhibitor resistance.

    Park, Kang-Seo; Raffeld, Mark; Moon, Yong Wha; Xi, Liqiang; Bianco, Caterina; Pham, Trung; Lee, Liam C; Mitsudomi, Tetsuya; Yatabe, Yasushi; Okamoto, Isamu; Subramaniam, Deepa; Mok, Tony; Rosell, Rafael; Luo, Ji; Salomon, David S; Wang, Yisong; Giaccone, Giuseppe

    2014-07-01

    The majority of non-small cell lung cancer (NSCLC) patients harbor EGFR-activating mutations that can be therapeutically targeted by EGFR tyrosine kinase inhibitors (EGFR-TKI), such as erlotinib and gefitinib. Unfortunately, a subset of patients with EGFR mutations are refractory to EGFR-TKIs. Resistance to EGFR inhibitors reportedly involves SRC activation and induction of epithelial-to-mesenchymal transition (EMT). Here, we have demonstrated that overexpression of CRIPTO1, an EGF-CFC protein family member, renders EGFR-TKI-sensitive and EGFR-mutated NSCLC cells resistant to erlotinib in culture and in murine xenograft models. Furthermore, tumors from NSCLC patients with EGFR-activating mutations that were intrinsically resistant to EGFR-TKIs expressed higher levels of CRIPTO1 compared with tumors from patients that were sensitive to EGFR-TKIs. Primary NSCLC cells derived from a patient with EGFR-mutated NSCLC that was intrinsically erlotinib resistant were CRIPTO1 positive, but gained erlotinib sensitivity upon loss of CRIPTO1 expression during culture. CRIPTO1 activated SRC and ZEB1 to promote EMT via microRNA-205 (miR-205) downregulation. While miR-205 depletion induced erlotinib resistance, miR-205 overexpression inhibited CRIPTO1-dependent ZEB1 and SRC activation, restoring erlotinib sensitivity. CRIPTO1-induced erlotinib resistance was directly mediated through SRC but not ZEB1; therefore, cotargeting EGFR and SRC synergistically attenuated growth of erlotinib-resistant, CRIPTO1-positive, EGFR-mutated NSCLC cells in vitro and in vivo, suggesting that this combination may overcome intrinsic EGFR-inhibitor resistance in patients with CRIPTO1-positive, EGFR-mutated NSCLC. PMID:24911146

  14. Helicobacter pylori Activates Matrix Metalloproteinase 10 in Gastric Epithelial Cells via EGFR and ERK-mediated Pathways.

    Costa, Angela M; Ferreira, Rui M; Pinto-Ribeiro, Ines; Sougleri, Ioanna S; Oliveira, Maria J; Carreto, Laura; Santos, Manuel A; Sgouras, Dionyssios N; Carneiro, Fatima; Leite, Marina; Figueiredo, Ceu

    2016-06-01

    Helicobacter pylori colonizes the human stomach and increases the risk for peptic ulcer disease and gastric carcinoma. H. pylori upregulates the expression and activity of several matrix metalloproteinases (MMPs) in cell lines and in the gastric mucosa. The aim of this study was to explore the mechanisms leading to upregulation of MMP10 in gastric epithelial cells induced by H. pylori Infection of gastric cells with H. pylori led to an increase in levels of MMP-10 messenger RNA, protein secretion, and activity. cagA knockout mutants or CagA phosphorylation-defective mutants failed to increase MMP10 expression. These results were confirmed in infection experiments with clinical isolates with known cagA status and in human gastric biopsy specimens. Treatment of cells with chemical inhibitors of the receptor tyrosine kinase EGFR and the kinase Src abrogated H. pylori-induced MMP10 expression. Inhibitors of ERK1/2 and JNK kinases abolished and significantly decreased H. pylori-induced MMP10 expression, respectively, whereas inhibition of the kinase p38 had no effect. Finally, inhibition of MMP10 expression by small interfering RNA led to a decrease in the gastric cell-invasive phenotype mediated by the infection. In conclusion, CagA-positive H. pylori strains stimulate MMP10 expression. MMP-10 modulation occurs via EGFR activation in a process that involves Src, ERK, and JNK pathways. MMP-10 may be implicated in H. pylori-mediated extracellular matrix remodeling. PMID:26802142

  15. ADAM17-siRNA inhibits MCF-7 breast cancer through EGFR-PI3K-AKT activation.

    Meng, Xiangchao; Hu, Baoshan; Hossain, Mohammad Monir; Chen, Guofu; Sun, Ying; Zhang, Xuepeng

    2016-08-01

    A disintegrin and metalloproteinase-17 (ADAM17) can cut and release a wide variety of epidermal growth factor receptor (EGFR) ligands to promote survival, invasion and proliferation of cancer cell, and therefore, is considered to be a potential therapeutic target for cancer. The main goal of the present study was to observe the effects of ADAM17 small interfering RNA (ADAM17-siRNA) on human MCF-7 breast cancer and investigate its activation pathway. In vitro, MCF-7 cells were divided into ADAM17-siRNA groups, nonsense siRNA groups, AG1478 (selective EGFR blocker) groups, LY294002 [phosphatidylinositol 3-kinase (PI3K) phosphorylation inhibitor] groups, PD0325901 [mitogen extracellular kinase (MEK) inhibitor] groups and control groups. In vivo, MCF-7 cells were implanted subcutaneously into nude mice and then these mice were randomly divided into ADAM17-siRNA groups, vector groups and control groups. Our data showed that compared with the control groups, ADAM17-siRNA, AG1478 and LY294002 could inhibit the migration and proliferation of MCF-7 cells, but PD0325901 and nonsense siRNA did not show this effect. Except that specific ADAM17-siRNA could inhibit the expression of ADAM17 mRNA, others did not change it. Western blot analysis further confirmed that EGFR-PI3K-AKT signaling pathway is involved in ADAM17-siRNA inhibiting migration and proliferation of MCF-7 cells. Similarly to the former, the growth of MCF-7 breast cancer in nude mice was significantly inhibited by ADAM17-siRNA. Compared with the control group and the vector group, the tumor volume was smaller in the ADAM17-siRNA group, the tissues developed large areas of necrosis, immunohistochemistry showed low expressions of ADAM17 and Ki-67 and western blot analysis proved that the expression of ADAM17 protein in the tissue was also reduced. The present study suggests that ADAM17-siRNA inhibits MCF-7 breast cancer and is activated through the EGFR-PI3K-AKT signaling pathway. PMID:27221510

  16. Nuclear epidermal growth factor receptor (EGFR) interacts with signal transducer and activator of transcription 5 (STAT5) in activating Aurora-A gene expression

    Hung, Liang-Yi; Tseng, Joseph T.; Lee, Yi-Chao; Xia, Weiya; Wang, Ying-Nai; Wu, Min-Li; Chuang, Yu-Hsuan; Lai, Chein-Hsien; Chang, Wen-Chang

    2008-01-01

    Loss of the maintenance of genetic material is a critical step leading to tumorigenesis. It was reported that overexpression of Aurora-A and the constitutive activation of the epidermal growth factor (EGF) receptor (EGFR) are implicated in chromosome instability. In this study, we examined that when cells treated with EGF result in centrosome amplification and microtubule disorder, which are critical for genetic instability. Interestingly, the expression of Aurora-A was also increased by EGF ...

  17. INHIBITION OF PHOSPHATASE ACTIVITY MEDIATES EPIDERMAL GROWTH FACTOR RECEPTOR (EGFR) SIGNALING IN HUMAN AIRWAY EPITHELIAL CELLS (HAEC) EXPOSED TO ZN2+

    A number of studies have implicated zinc in the toxicity of ambient particulate matter (PM) inhalation. We previously showed that exposure to metal-laden particulate matter inhibits protein tyrosine phosphatase activity in HAEC and leads to Src-dependent activation of EGFR sign...

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

    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.

  19. Panaxydol, a component of Panax ginseng, induces apoptosis in cancer cells through EGFR activation and ER stress and inhibits tumor growth in mouse models.

    Kim, Hee Suk; Lim, Jang Mi; Kim, Joo Young; Kim, Yongjin; Park, Serkin; Sohn, Jeongwon

    2016-03-15

    We reported previously that panaxydol, a component of Panax ginseng roots, induced mitochondria-mediated apoptosis preferentially in transformed cells. This study demonstrates that EGFR activation and the resulting ER stress mediate panaxydol-induced apoptosis, and that panaxydol suppresses in vivo tumor growth in syngeneic and xenogeneic mouse tumor models. In addition, we elucidated that CaMKII and TGF-β-activated kinase (TAK1) participate in p38/JNK activation by elevated cytoplasmic Ca(2+) concentration ([Ca(2+)]c). In MCF-7 cells, EGFR was activated immediately after exposure to panaxydol, and this activation was necessary for induction of apoptosis, suggesting that panaxydol might be a promising anticancer candidate, especially for EGFR-addicted cancer. Activation of PLCγ followed EGFR activation, resulting in Ca(2+) release from the endoplasmic reticulum (ER) via inositol triphosphate and ryanodine receptors. ER Ca(2+) release triggered mitochondrial Ca(2+) uptake indirectly through oxidative stress and ensuing ER stress. Elevated [Ca(2+)]c triggered sequential activation of calmodulin/CaMKII, TAK1 and p38/JNK. As shown previously, p38 and JNK activate NADPH oxidase. Here, it was shown that the resulting oxidative stress triggered ER stress. Among the three signaling branches of the unfolded protein response, protein kinase R-like ER kinase (PERK), but not inositol-requiring enzyme 1 or activating transcription factor 6, played a role in transmitting the apoptosis signal. PERK induced C/EBP homologous protein (CHOP), and CHOP elevated Bim expression, initiating mitochondrial Ca(2+) uptake and apoptosis. In summary, we identified roles of EGFR, the CAMKII-TAK1-p38/JNK pathway, and ER stress in panaxydol-induced apoptosis and demonstrated the in vivo anticancer effect of panaxydol. PMID:26421996

  20. Squamosamide derivative FLZ protects retinal pigment epithelium cells from oxidative stress through activation of epidermal growth factor receptor (EGFR)-AKT signaling.

    Cheng, Li-Bo; Chen, Chun-Ming; Zhong, Hong; Zhu, Li-Juan

    2014-01-01

    Reactive oxygen species (ROS)-mediated retinal pigment epithelium (RPE) cell apoptosis is attributed to age-related macular degeneration (AMD) pathogenesis. FLZ, a novel synthetic squamosamide derivative from a Chinese herb, Annona glabra, has displayed significant cyto-protective activity. In the current study, we explored the pro-survival effect of FLZ in oxidative stressed-RPE cells and studied the underlying signaling mechanisms. Our results showed that FLZ attenuated hydrogen peroxide (H2O2)-induced viability decrease and apoptosis in the RPE cell line (ARPE-19 cells) and in primary mouse RPE cells. Western blotting results showed that FLZ activated AKT signaling in RPE cells. The AKT-specific inhibitor, MK-2206, the phosphoinositide 3-kinase (PI3K)/AKT pan inhibitor, wortmannin, and AKT1-shRNA (short hairpin RNA) depletion almost abolished FLZ-mediated pro-survival/anti-apoptosis activity. We discovered that epidermal growth factor receptor (EGFR) trans-activation mediated FLZ-induced AKT activation and the pro-survival effect in RPE cells, and the anti-apoptosis effect of FLZ against H2O2 was inhibited by the EGFR inhibitor, PD153035, or by EGFR shRNA-knockdown. In conclusion, FLZ protects RPE cells from oxidative stress through activation of EGFR-AKT signaling, and our results suggest that FLZ might have therapeutic values for AMD. PMID:25329617

  1. Targeting SHP2 for EGFR inhibitor resistant non-small cell lung carcinoma

    Xu, Jie; Zeng, Li-Fan; Shen, Weihua [Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis (United States); Turchi, John J. [Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis (United States); Department of Medicine, Indiana University School of Medicine, Indianapolis (United States); Zhang, Zhong-Yin, E-mail: zyzhang@iu.edu [Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis (United States)

    2013-10-04

    Highlights: •SHP2 is required for EGFR inhibitor resistant NSCLC H1975 cell proliferation. •SHP2 inhibitor blocks EGF-stimulated ERK1/2 activation and proliferation. •SHP2 inhibitor exhibits marked anti-tumor activity in H1975 xenograft mice. •SHP2 inhibitor synergizes with PI3K inhibitor in suppressing cell growth. •Targeting SHP2 represents a novel strategy for EGFR inhibitor resistant NSCLCs. -- Abstract: Targeted therapy with inhibitors of epidermal growth factor receptor (EGFR) has produced a noticeable benefit to non-small cell lung cancer (NSCLC) patients whose tumors carry activating mutations (e.g. L858R) in EGFR. Unfortunately, these patients develop drug resistance after treatment, due to acquired secondary gatekeeper mutations in EGFR (e.g. T790M). Given the critical role of SHP2 in growth factor receptor signaling, we sought to determine whether targeting SHP2 could have therapeutic value for EGFR inhibitor resistant NSCLC. We show that SHP2 is required for EGF-stimulated ERK1/2 phosphorylation and proliferation in EGFR inhibitor resistant NSCLC cell line H1975, which harbors the EGFR T790M/L858R double-mutant. We demonstrate that treatment of H1975 cells with II-B08, a specific SHP2 inhibitor, phenocopies the observed growth inhibition and reduced ERK1/2 activation seen in cells treated with SHP2 siRNA. Importantly, we also find that II-B08 exhibits marked anti-tumor activity in H1975 xenograft mice. Finally, we observe that combined inhibition of SHP2 and PI3K impairs both the ERK1/2 and PI3K/AKT signaling axes and produces significantly greater effects on repressing H1975 cell growth than inhibition of either protein individually. Collectively, these results suggest that targeting SHP2 may represent an effective strategy for treatment of EGFR inhibitor resistant NSCLCs.

  2. Targeting SHP2 for EGFR inhibitor resistant non-small cell lung carcinoma

    Highlights: •SHP2 is required for EGFR inhibitor resistant NSCLC H1975 cell proliferation. •SHP2 inhibitor blocks EGF-stimulated ERK1/2 activation and proliferation. •SHP2 inhibitor exhibits marked anti-tumor activity in H1975 xenograft mice. •SHP2 inhibitor synergizes with PI3K inhibitor in suppressing cell growth. •Targeting SHP2 represents a novel strategy for EGFR inhibitor resistant NSCLCs. -- Abstract: Targeted therapy with inhibitors of epidermal growth factor receptor (EGFR) has produced a noticeable benefit to non-small cell lung cancer (NSCLC) patients whose tumors carry activating mutations (e.g. L858R) in EGFR. Unfortunately, these patients develop drug resistance after treatment, due to acquired secondary gatekeeper mutations in EGFR (e.g. T790M). Given the critical role of SHP2 in growth factor receptor signaling, we sought to determine whether targeting SHP2 could have therapeutic value for EGFR inhibitor resistant NSCLC. We show that SHP2 is required for EGF-stimulated ERK1/2 phosphorylation and proliferation in EGFR inhibitor resistant NSCLC cell line H1975, which harbors the EGFR T790M/L858R double-mutant. We demonstrate that treatment of H1975 cells with II-B08, a specific SHP2 inhibitor, phenocopies the observed growth inhibition and reduced ERK1/2 activation seen in cells treated with SHP2 siRNA. Importantly, we also find that II-B08 exhibits marked anti-tumor activity in H1975 xenograft mice. Finally, we observe that combined inhibition of SHP2 and PI3K impairs both the ERK1/2 and PI3K/AKT signaling axes and produces significantly greater effects on repressing H1975 cell growth than inhibition of either protein individually. Collectively, these results suggest that targeting SHP2 may represent an effective strategy for treatment of EGFR inhibitor resistant NSCLCs

  3. ROLE OF THE EPIDERMAL GROWTH FACTOR RECEPTOR (EGFR) IN THE ACTIVATION OF MEK INDUCED BY ZN EXPOSURE

    Zn is a ubiquitous ambient air pollutant typically found associated with particulate matter. Divalent Zn inhibits tyrosine phosphatases and induces EGFR- and MAPK- dependent signaling in human airway epithelial cells. To further characterize Zn-induced intracellular signaling, ...

  4. EGFR-targeted TRAIL and a Smac mimetic synergize to overcome apoptosis resistance in KRAS mutant colorectal cancer cells.

    Yvonne Möller

    Full Text Available TRAIL is a death receptor ligand that induces cell death preferentially in tumor cells. Recombinant soluble TRAIL, however, performs poorly as an anti-cancer therapeutic because oligomerization is required for potent biological activity. We previously generated a diabody format of tumor-targeted TRAIL termed Db(αEGFR-scTRAIL, comprising single-stranded TRAIL molecules (scTRAIL and the variable domains of a humanized variant of the EGFR blocking antibody Cetuximab. Here we define the bioactivity of Db(αEGFR-scTRAIL with regard to both EGFR inhibition and TRAIL receptor activation in 3D cultures of Caco-2 colorectal cancer cells, which express wild-type K-Ras. Compared with conventional 2D cultures, Caco-2 cells displayed strongly enhanced sensitivity toward Db(αEGFR-scTRAIL in these 3D cultures. We show that the antibody moiety of Db(αEGFR-scTRAIL not only efficiently competed with ligand-induced EGFR function, but also determined the apoptotic response by specifically directing Db(αEGFR-scTRAIL to EGFR-positive cells. To address how aberrantly activated K-Ras, which leads to Cetuximab resistance, affects Db(αEGFR-scTRAIL sensitivity, we generated stable Caco-2tet cells inducibly expressing oncogenic K-Ras(G12V. In the presence of doxycycline, these cells showed increased resistance to Db(αEGFR-scTRAIL, associated with the elevated expression of the anti-apoptotic proteins cIAP2, Bcl-xL and FlipS. Co-treatment of cells with the Smac mimetic SM83 restored the Db(αEGFR-scTRAIL-induced apoptotic response. Importantly, this synergy between Db(αEGFR-scTRAIL and SM83 also translated to 3D cultures of oncogenic K-Ras expressing HCT-116 and LoVo colorectal cancer cells. Our findings thus support the notion that Db(αEGFR-scTRAIL therapy in combination with apoptosis-sensitizing agents may be promising for the treatment of EGFR-positive colorectal cancers, independently of their KRAS status.

  5. Activation of Multiple ERBB Family Receptors Mediates Glioblastoma Cancer Stem-like Cell Resistance to EGFR-Targeted Inhibition12

    Clark, Paul A.; Iida, Mari; Daniel M. Treisman; Kalluri, Haviryaji; Ezhilan, Sathyapriya; Zorniak, Michael; Deric L. Wheeler; Kuo, John S.

    2012-01-01

    Epidermal growth factor receptor (EGFR) signaling is strongly implicated in glioblastoma (GBM) tumorigenesis. However, molecular agents targeting EGFR have demonstrated minimal efficacy in clinical trials, suggesting the existence of GBM resistance mechanisms. GBM cells with stem-like properties (CSCs) are highly efficient at tumor initiation and exhibit therapeutic resistance. In this study, GBMCSC lines showed sphere-forming and tumor initiation capacity after EGF withdrawal from cell cultu...

  6. Synergistic antitumor effect between gefitinib and fractionated irradiation in anaplastic oligodendrogliomas cannot be predicted by the Egfr signaling activity.

    Sophie Pinel; Jihane Mriouah; Marc Vandamme; Alicia Chateau; François Plénat; Eric Guérin; Luc Taillandier; Valérie Bernier-Chastagner; Jean-Louis Merlin; Pascal Chastagner

    2013-01-01

    International audience In high-grade gliomas, the identification of patients that could benefit from EGFR inhibitors remains a challenge, hindering the use of these agents. Using xenografts models, we evaluated the antitumor effect of the combined treatment "gefitinib + radiotherapy" and aimed to identify the profile of responsive tumors. Expression of phosphorylated proteins involved in the EGFR-dependent signaling pathways was analyzed in 10 glioma models. We focused on three models of a...

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

    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.

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

    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 G1 arrest. T98 cells were a little more refractory to growth inhibition and A172 cells did not undergo a G1 arrest. This G1 arrest was associated with up-regulation of p27kip1, 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 G1 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 ΔEGFR 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.

  9. Discovery of a series of novel phenylpiperazine derivatives as EGFR TK inhibitors

    Sun, Juan; Wang, Xin-Yi; Lv, Peng-Cheng; Zhu, Hai-Liang

    2015-09-01

    Human epidermal growth factor receptor (EGFR) is an important drug target that plays a fundamental role in signal transduction pathways in oncology. We report herein the discovery of a novel class of phenylpiperazine derivatives with improved potency toward EGFR. The biological activity of compound 3p as inhibitor of EGFR was further investigated both in vitro and in vivo. Notably, compound 3p exhibited an IC50 in the nanomolar range in A549 cell cultures and induced a cessation of tumor growth with no toxicity, as determined by loss of body weight and death of treated mice. Compoutational docking studies also showed that compound 3p has interaction with EGFR key residues in the active site.

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

    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.

  11. Monocytes/macrophages support mammary tumor invasivity by co-secreting lineage-specific EGFR ligands and a STAT3 activator

    Tumor-associated macrophages (TAM) promote malignant progression, yet the repertoire of oncogenic factors secreted by TAM has not been clearly defined. We sought to analyze which EGFR- and STAT3-activating factors are secreted by monocytes/macrophages exposed to tumor cell-secreted factors. Following exposure of primary human monocytes and macrophages to supernatants of a variety of tumor cell lines, we have analyzed transcript and secreted protein levels of EGFR family ligands and of STAT3 activators. To validate our findings, we have analyzed TAM infiltration levels, systemic and local protein levels as well as clinical data of primary breast cancer patients. Primary human monocytes and macrophages respond to tumor cell-derived factors by secreting EGFR- and STAT3-activating ligands, thus inducing two important oncogenic pathways in carcinoma cells. Tumor cell-secreted factors trigger two stereotype secretory profiles in peripheral blood monocytes and differentiated macrophages: monocytes secrete epiregulin (EREG) and oncostatin-M (OSM), while macrophages secrete heparin-binding EGF-like growth factor (HB-EGF) and OSM. HB-EGF and OSM cooperatively induce tumor cell chemotaxis. HB-EGF and OSM are co-expressed by TAM in breast carcinoma patients, and plasma levels of both ligands correlate strongly. Elevated HB-EGF levels accompany TAM infiltration, tumor growth and dissemination in patients with invasive disease. Our work identifies systemic markers for TAM involvement in cancer progression, with the potential to be developed into molecular targets in cancer therapy

  12. Protein phosphorylation profiling using an in situ proximity ligation assay: phosphorylation of AURKA-elicited EGFR-Thr654 and EGFR-Ser1046 in lung cancer cells.

    Tzu-Chi Chen

    Full Text Available The epidermal growth factor receptor (EGFR, which is up-regulated in lung cancer, involves the activation of mitogenic signals and triggers multiple signaling cascades. To dissect these EGFR cascades, we used 14 different phospho-EGFR antibodies to quantify protein phosphorylation using an in situ proximity ligation assay (in situ PLA. Phosphorylation at EGFR-Thr654 and -Ser1046 was EGF-dependent in the wild-type (WT receptor but EGF-independent in a cell line carrying the EGFR-L858R mutation. Using a ProtoAarray™ containing ∼5000 recombinant proteins on the protein chip, we found that AURKA interacted with the EGFR-L861Q mutant. Moreover, overexpression of EGFR could form a complex with AURKA, and the inhibitors of AURKA and EGFR decreased EGFR-Thr654 and -Ser1046 phosphorylation. Immunohistochemical staining of stage I lung adenocarcinoma tissues demonstrated a positive correlation between AURKA expression and phosphorylation of EGFR at Thr654 and Ser1046 in EGFR-mutant specimens, but not in EGFR-WT specimens. The interplay between EGFR and AURKA provides an explanation for the difference in EGF dependency between EGFR-WT and EGFR-mutant cells and may provide a new therapeutic strategy for lung cancer patients carrying EGFR mutations.

  13. Sonic Hedgehog modulates EGFR dependent proliferation of neural stem cells during late mouse embryogenesis through EGFR transactivation

    Reinchisi, Gisela; Parada, Margarita; Lois, Pablo; Oyanadel, Claudia; Shaughnessy, Ronan; Gonzalez, Alfonso; Palma, Verónica

    2013-01-01

    Sonic Hedgehog (Shh/GLI) and EGFR signaling pathways modulate Neural Stem Cell (NSC) proliferation. How these signals cooperate is therefore critical for understanding normal brain development and function. Here we report a novel acute effect of Shh signaling on EGFR function. We show that during late neocortex development, Shh mediates the activation of the ERK1/2 signaling pathway in Radial Glial cells (RGC) through EGFR transactivation. This process is dependent on metalloprotease activity and accounts for almost 50% of the EGFR-dependent mitogenic response of late NSCs. Furthermore, in HeLa cancer cells, a well-known model for studying the EGFR receptor function, Shh also induces cell proliferation involving EGFR activation, as reflected by EGFR internalization and ERK1/2 phosphorylation. These findings may have important implications for understanding the mechanisms that regulate NSC proliferation during neurogenesis and may lead to novel approaches to the treatment of tumors. PMID:24133411

  14. EGFR-mediated carcinoma cell metastasis mediated by integrin αvβ5 depends on activation of c-Src and cleavage of MUC1.

    Steven K M Lau

    Full Text Available Receptor tyrosine kinases and integrins play an essential role in tumor cell invasion and metastasis. We previously showed that EGF and other growth factors induce human carcinoma cell invasion and metastasis mediated by integrin αvβ5 that is prevented by Src blockade. MUC1, a transmembrane glycoprotein, is expressed in most epithelial tumors as a heterodimer consisting of an extracellular and a transmembrane subunit. The MUC1 cytoplasmic domain of the transmembrane subunit (MUC1.CD translocates to the nucleus where it promotes the transcription of a metastatic gene signature associated with epithelial to mesenchymal transition. Here, we demonstrate a requirement for MUC1 in carcinoma cell metastasis dependent on EGFR and Src without affecting primary tumor growth. EGF stimulates Src-dependent MUC1 cleavage and nuclear localization leading to the expression of genes linked to metastasis. Moreover, expression of MUC1.CD results in its nuclear localization and is sufficient for transcription of the metastatic gene signature and tumor cell metastasis. These results demonstrate that EGFR and Src activity contribute to carcinoma cell invasion and metastasis mediated by integrin αvβ5 in part by promoting proteolytic cleavage of MUC1 and highlight the ability of MUC1.CD to promote metastasis in a context-dependent manner. Our findings may have implications for the use and future design of targeted therapies in cancers known to express EGFR, Src, or MUC1.

  15. Plant polyphenols differentially modulate inflammatory responses of human keratinocytes by interfering with activation of transcription factors NFκB and AhR and EGFR-ERK pathway

    Molecular mechanisms underlying modulation of inflammatory responses in primary human keratinocytes by plant polyphenols (PPs), namely the glycosylated phenylpropanoid verbascoside, the stilbenoid resveratrol and its glycoside polydatin, and the flavonoid quercetin and its glycoside rutin were evaluated. As non-lethal stimuli, the prototypic ligand for epidermal growth factor receptor (EGFR) transforming growth factor alpha (TGFalpha), the combination of tumor necrosis factor (TNFalpha) and interferon (IFNgamma) (T/I), UVA + UVB irradiation, and bacterial lipopolysaccharide (LPS) were used. We demonstrated differential modulation of inflammatory responses in keratinocytes at signal transduction, gene transcription, and protein synthesis levels as a function of PP chemical structure, the pro-inflammatory trigger used, and PP interaction with intracellular detoxifying systems. The PPs remarkably inhibited constitutive, LPS- and T/I-induced but not TGFalpha-induced ERK phosphorylation. They also suppressed NFkappaB activation by LPS and T/I. Verbascoside and quercetin invariably impaired EGFR phosphorylation and UV-associated aryl hydrocarbon receptor (AhR)-mediated signaling, while rutin, polydatin and resveratrol did not affect EGFR phosphorylation and further activated AhR machinery in UV-exposed keratinocytes. In general, PPs down-regulated gene expression of pro-inflammatory cytokines/enzymes, except significant up-regulation of IL-8 observed under stimulation with TGFalpha. Both spontaneous and T/I-induced release of IL-8 and IP-10 was suppressed, although 50 μM resveratrol and polydatin up-regulated IL-8. At this concentration, resveratrol activated both gene expression and de novo synthesis of IL-8 and AhR-mediated mechanisms were involved. We conclude that PPs differentially modulate the inflammatory response of human keratinocytes through distinct signal transduction pathways, including AhR and EGFR. - Graphical abstract: Display Omitted Highlights:

  16. Activation of EGFR/ERBB2 via Pathways Involving ERK1/2, P38 MAPK, AKT and FOXO Enhances Recovery of Diabetic Hearts from Ischemia-Reperfusion Injury

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

    2012-01-01

    This study characterized the effects of diabetes and/or ischemia on epidermal growth factor receptor, EGFR, and/or erbB2 signaling pathways on cardiac function. Isolated heart perfusion model of global ischemia was used to study the effect of chronic inhibition or acute activation of EGFR/erbB2 signaling on cardiac function in a rat model of type-1 diabetes. Induction of diabetes with streptozotocin impaired recovery of cardiac function (cardiac contractility and hemodynamics) following 40 minutes of global ischemia in isolated hearts. Chronic treatment with AG825 or AG1478, selective inhibitors of erbB2 and EGFR respectively, did not affect hyperglycemia but led to an exacerbation whereas acute administration of the EGFR ligand, epidermal growth factor (EGF), led to an improvement in cardiac recovery in diabetic hearts. Diabetes led to attenuated dimerization and phosphorylation of cardiac erbB2 and EGFR receptors that was associated with reduced signaling via extracellular-signal-regulated kinase 1/2 (ERK1/2), p38 mitogen activated protein (MAP) kinase and AKT (protein kinase B). Ischemia was also associated with reduced cardiac signaling via these molecules whereas EGF-treatment opposed diabetes and/or ischemia induced changes in ERK1/2, p38 MAP kinase, and AKT-FOXO signaling. Losartan treatment improved cardiac function in diabetes but also impaired EGFR phosphorylation in diabetic heart. Co-administration of EGF rescued Losartan-mediated reduction in EGFR phosphorylation and significantly improved cardiac recovery more than with either agent alone. EGFR/erbB2 signaling is an important cardiac survival pathway whose activation, particularly in diabetes, ischemia or following treatment with drugs that inhibit this cascade, significantly improves cardiac function. These findings may have clinical relevance particularly in the treatment of diabetes-induced cardiac dysfunction. PMID:22720029

  17. Activation of EGFR/ERBB2 via pathways involving ERK1/2, P38 MAPK, AKT and FOXO enhances recovery of diabetic hearts from ischemia-reperfusion injury.

    Saghir Akhtar

    Full Text Available This study characterized the effects of diabetes and/or ischemia on epidermal growth factor receptor, EGFR, and/or erbB2 signaling pathways on cardiac function. Isolated heart perfusion model of global ischemia was used to study the effect of chronic inhibition or acute activation of EGFR/erbB2 signaling on cardiac function in a rat model of type-1 diabetes. Induction of diabetes with streptozotocin impaired recovery of cardiac function (cardiac contractility and hemodynamics following 40 minutes of global ischemia in isolated hearts. Chronic treatment with AG825 or AG1478, selective inhibitors of erbB2 and EGFR respectively, did not affect hyperglycemia but led to an exacerbation whereas acute administration of the EGFR ligand, epidermal growth factor (EGF, led to an improvement in cardiac recovery in diabetic hearts. Diabetes led to attenuated dimerization and phosphorylation of cardiac erbB2 and EGFR receptors that was associated with reduced signaling via extracellular-signal-regulated kinase 1/2 (ERK1/2, p38 mitogen activated protein (MAP kinase and AKT (protein kinase B. Ischemia was also associated with reduced cardiac signaling via these molecules whereas EGF-treatment opposed diabetes and/or ischemia induced changes in ERK1/2, p38 MAP kinase, and AKT-FOXO signaling. Losartan treatment improved cardiac function in diabetes but also impaired EGFR phosphorylation in diabetic heart. Co-administration of EGF rescued Losartan-mediated reduction in EGFR phosphorylation and significantly improved cardiac recovery more than with either agent alone. EGFR/erbB2 signaling is an important cardiac survival pathway whose activation, particularly in diabetes, ischemia or following treatment with drugs that inhibit this cascade, significantly improves cardiac function. These findings may have clinical relevance particularly in the treatment of diabetes-induced cardiac dysfunction.

  18. Biological activity determination

    Madronová, L.; Novák, J.; Kubíček, J.; Antošová, B.; Kozler, J.; Novák, František

    New York: Nova Science Publisher, 2011 - (Madronová, L.), s. 85-103. (Chemistry Research and Applications). ISBN 978-1-61668-965-0 Institutional research plan: CEZ:AV0Z60660521 Keywords : biological activity * determination * potassium humate samples Subject RIV: CB - Analytical Chemistry, Separation

  19. Sym004, a novel EGFR antibody mixture, can overcome acquired resistance to cetuximab.

    Iida, Mari; Brand, Toni M; Starr, Megan M; Li, Chunrong; Huppert, Evan J; Luthar, Neha; Pedersen, Mikkel W; Horak, Ivan D; Kragh, Michael; Wheeler, Deric L

    2013-10-01

    The epidermal growth factor receptor (EGFR) is a central regulator of tumor progression in a variety of human cancers. Cetuximab is an anti-EGFR monoclonal antibody that has been approved for head and neck and colorectal cancer treatment, but many patients treated with cetuximab don't respond or eventually acquire resistance. To determine how tumor cells acquire resistance to cetuximab, we previously developed a model of acquired resistance using the non-small cell lung cancer line NCI-H226. These cetuximab-resistant (Ctx(R)) cells exhibit increased steady-state EGFR expression secondary to alterations in EGFR trafficking and degradation and, further, retained dependence on EGFR signaling for enhanced growth potential. Here, we examined Sym004, a novel mixture of antibodies directed against distinct epitopes on the extracellular domain of EGFR, as an alternative therapy for Ctx(R) tumor cells. Sym004 treatment of Ctx(R) clones resulted in rapid EGFR degradation, followed by robust inhibition of cell proliferation and down-regulation of several mitogen-activated protein kinase pathways. To determine whether Sym004 could have therapeutic benefit in vivo, we established de novo Ctx(R) NCI-H226 mouse xenografts and subsequently treated Ctx(R) tumors with Sym004. Sym004 treatment of mice harboring Ctx(R) tumors resulted in growth delay compared to mice continued on cetuximab. Levels of total and phospho-EGFR were robustly decreased in Ctx(R) tumors treated with Sym004. Immunohistochemical analysis of these Sym004-treated xenograft tumors further demonstrated decreased expression of Ki67, and phospho-rpS6, as well as a modest increase in cleaved caspase-3. These results indicate that Sym004 may be an effective targeted therapy for Ctx(R) tumors. PMID:24204198

  20. Sym004, a Novel EGFR Antibody Mixture, Can Overcome Acquired Resistance to Cetuximab

    Mari Iida

    2013-10-01

    Full Text Available The epidermal growth factor receptor (EGFR is a central regulator of tumor progression in a variety of human cancers. Cetuximab is an anti-EGFR monoclonal antibody that has been approved for head and neck and colorectal cancer treatment, but many patients treated with cetuximab don't respond or eventually acquire resistance. To determine how tumor cells acquire resistance to cetuximab, we previously developed a model of acquired resistance using the non-small cell lung cancer line NCI-H226. These cetuximab-resistant (CtxR cells exhibit increased steady-state EGFR expression secondary to alterations in EGFR trafficking and degradation and, further, retained dependence on EGFR signaling for enhanced growth potential. Here, we examined Sym004, a novel mixture of antibodies directed against distinct epitopes on the extracellular domain of EGFR, as an alternative therapy for CtxR tumor cells. Sym004 treatment of CtxR clones resulted in rapid EGFR degradation, followed by robust inhibition of cell proliferation and down-regulation of several mitogen-activated protein kinase pathways. To determine whether Sym004 could have therapeutic benefit in vivo, we established de novo CtxR NCI-H226 mouse xenografts and subsequently treated CtxR tumors with Sym004. Sym004 treatment of mice harboring CtxR tumors resulted in growth delay compared to mice continued on cetuximab. Levels of total and phospho-EGFR were robustly decreased in CtxR tumors treated with Sym004. Immunohistochemical analysis of these Sym004-treated xenograft tumors further demonstrated decreased expression of Ki67, and phospho-rpS6, as well as a modest increase in cleaved caspase-3. These results indicate that Sym004 may be an effective targeted therapy for CtxR tumors.

  1. Interaction between EGFR and EphA2

    Larsen, Alice Bjerregaard

    2010-01-01

    including those originating from the brain, breast, cervix, colon, head and neck, kidney, lung, esophagus, ovary, prostate, skin and stomach. Moreover, high EphA2 expression has been correlated with increased tumor volume, short overall survival and increasing evidence also suggest that EphA2 is involved in......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...

  2. Targeted treatment of mutated EGFR-expressing non-small-cell lung cancer: focus on erlotinib with companion diagnostics

    Karachaliou N

    2014-11-01

    Full Text Available Niki Karachaliou,1 Rafael Rosell21Translational Research Unit, Dr Rosell Oncology Institute, Quirón Dexeus University Hospital, 2Cancer Biology and Precision Medicine Program, Catalan Institute of Oncology, Hospital Germans Trias i Pujol, Barcelona, SpainAbstract: Deeper understanding of the pathobiology of non-small-cell lung cancer (NSCLC has led to the development of small molecules that target genetic mutations known to play critical roles in the progression to metastatic disease. The discovery of epidermal growth factor receptor (EGFR mutations in 15%–20% of lung adenocarcinomas and the associated response to EGFR tyrosine kinase inhibitors have provided a successful avenue of attack in late-stage adenocarcinomas. Use of the EGFR tyrosine kinase inhibitors gefitinib, erlotinib, and afatinib is limited to patients who have adenocarcinomas with known activating EGFR mutations. However, the EGFR mutation testing landscape is varied and includes many screening and targeted methods, each with its own benefits and limitations. These tests can simplify the drug discovery process, make clinical trials more efficient and informative, and individualize cancer therapy. In practice, the choice of method should be determined by the nature of the sample to be tested, the testing laboratory's expertise and access to equipment, and whether the detection of only known activating EGFR mutations, or of all possible mutations, is required. Development of companion diagnostic tests for this identification is advancing; nevertheless, the use of such tests merits greater attention.Keywords: lung adenocarcinoma, EGFR mutations, companion diagnostics

  3. Intratumoral distribution of EGFR-amplified and EGFR-mutated cells in pulmonary adenocarcinoma.

    Soma, Shingo; Tsuta, Koji; Takano, Toshimi; Hatanaka, Yutaka; Yoshida, Akihiko; Suzuki, Kenji; Asamura, Hisao; Tsuda, Hitoshi

    2014-03-01

    Alterations in the epidermal growth factor receptor (EGFR) gene are associated with carcinogenesis in non-small cell lung cancer. However, the intratumoral distribution of these abnormalities has not been elucidated. This study included patients with surgically resected lung adenocarcinoma. The predominant histological growth pattern was determined. Chromogenic in situ hybridization (CISH) and EGFR-mutation specific-antibodies were used for analysis of changes in gene copy number and EGFR mutations, respectively. EGFR mutation detected immunohistochemistry (IHC) and amplification were identified in 31 (53%) and 30 (52%) cases, respectively. The predominant growth patterns in the 58 tumors evaluated were papillary (28, 48%), lepidic (8, 14%), acinar (15, 26%), and solid (7, 12%). EGFR mutations were the least common in cases with a solid predominant pattern. The incidence of EGFR amplification did not differ among predominant patterns. Analyzing each histological subtype, no differences were noted between the prevalence of EGFR-IHC positive and CISH-positive rates. In the analysis of EGFR amplification, CISH-positive status was more prevalent in IHC-positive cases than in IHC-negative cases. All 19 cases that were both IHC and CISH positive were analyzed. In 17 cases (90%), the IHC-positive area was equal to or larger than the CISH-positive area. Among the histological subtypes of lung adenocarcinoma, the solid predominant subtype was distinguishable by its infrequent EGFR mutations. EGFR gene mutations preceded changes in oncogenic drive, more so than did EGFR gene number alterations during the developmental process of lung adenocarcinoma. PMID:24355440

  4. Epidermal growth factor receptor (EGFR mutation status and Rad51 determine the response of glioblastoma (GBM to multimodality therapy with cetuximab, temozolomide and radiation

    PhyllisRachelleWachsberger

    2013-02-01

    Full Text Available Purpose: EGFR amplification and mutation (i.e., EGFRvIII are found in 40% of primary GBM tumors and are believed to contribute to tumor development and therapeutic resistance. This study was designed to investigate how EGFR mutational status modulates response to multimodality treatment with cetuximab, an anti-EGFR inhibitor, the chemotherapeutic agent, temozolamide (TMZ and radiation therapy (RT Methods and Materials: In vitro and in vivo experiments were performed on two isogenic U87 GBM cell lines: one overexpressing wildtype EGFR (U87wtEGFR and the other overexpressing EGFRvIII (U87EGFRvIII. Results: Xenografts harboring EGFRvIII were more sensitive to TMZ alone and TMZ in combination with RT and/or cetuximab than xenografts expressing wtEGFR. In vitro experiments demonstrated that U87EGFRvIII-expressing tumors appear to harbor defective DNA homologous recombination repair in the form of Rad51 processing, Conclusions: The difference in sensitivity between EGFR-expressing and EGFRvIII-expressing tumors to combined modality treatment may help in the future tailoring of GBM therapy to subsets of patients expressing more or less of the EGFR mutant.

  5. 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

    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.

  6. 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

    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.

  7. Nimotuzumab enhances temozolomide-induced growth suppression of glioma cells expressing mutant EGFR in vivo.

    Nitta, Yusuke; Shimizu, Saki; Shishido-Hara, Yukiko; Suzuki, Kaori; Shiokawa, Yoshiaki; Nagane, Motoo

    2016-03-01

    A mutant form of epidermal growth factor receptor (EGFR), EGFRvIII, is common in glioblastoma (GBM) and confers enhanced tumorigenic activity and drug resistance. Nimotuzumab, an anti-EGFR antibody, has shown preclinical and clinical activity to GBM, but its specific activity against EGFRvIII has not been fully investigated. Human glioma U87MG or LNZ308 cells overexpressing either wild-type (wt) EGFR or EGFRvIII were treated with nimotuzumab, temozolomide, or both. Expression and phosphorylation status of molecules were determined by Western blot analysis. Methylation status of promoter region of O(6) -methylguanine-DNA methyltransferase (MGMT) was detected by methylation-specific PCR. Antitumor activity was tested using nude mice bearing either subcutaneous or intracerebral xenografts along with analyses of EGFR phosphorylation status, proliferation, apoptosis, and vessel density. Nimotuzumab treatment resulted in reduction of EGFRvIII tyrosine phosphorylation with a decrease in Akt phosphorylation that was greater than that of wtEGFR. Correspondingly, antitumor effects, growth suppression and survival elongation, were more significant in mice bearing either subcutaneous or intracerebral tumor expressing EGFRvIII than in those expressing wtEGFR. These effects were markedly increased when temozolomide was combined with nimotuzumab. The post-treatment recurrent brain tumors exhibited a decrease in expression of the mismatch repair (MMR) proteins, MSH6 and MLH1, but their methylated MGMT status did not changed. Nimotuzumab has in vivo antitumor activity against GBM, especially those expressing EGFRvIII, when combined with temozolomide. This could provide a basis for preselection of patients with GBM by EGFR status who might benefit from the nimotuzumab and temozolomide combination therapy. PMID:26778701

  8. Truncation, modification, and optimization of MIG6(segment 2) peptide to target lung cancer-related EGFR.

    Yu, Xiao-Dong; Yang, Rui; Leng, Chang-Jun

    2016-04-01

    Human epidermal growth factor receptor (EGFR) plays a central role in the pathological progression and metastasis of lung cancer; the development and clinical application of therapeutic agents that target the receptor provide important insights for new lung cancer therapies. The tumor-suppressor protein MIG6 is a negative regulator of EGFR, which can bind at the activation interface of asymmetric dimer of EGFR kinase domains to disrupt dimerization and then inactivate the kinase (Zhang X. et al. Nature 2007, 450: 741-744). The protein adopts two separated segments, i.e. MIG6(segment 1) and MIG6(segment 2), to directly interact with EGFR. Here, computational modeling and analysis of the intermolecular interaction between EGFR kinase domain and MIG6(segment 2) peptide revealed that the peptide is folded into a two-stranded β-sheet composed of β-strand 1 and β-strand 2; only the β-strand 2 can directly interact with EGFR activation loop, while leaving β-strand 1 apart from the kinase. A C-terminal island within the β-strand 2 is primarily responsible for peptide binding, which was truncated from the MIG6(segment 2) and exhibited weak affinity to EGFR kinase domain. Structural and energetic analysis suggested that phosphorylation at residues Tyr394 and Tyr395 of truncated peptide can considerably improve EGFR affinity, and mutation of other residues can further optimize the peptide binding capability. Subsequently, three derivative versions of the truncated peptide, including phosphorylated and dephosphorylated peptides as well as a double-point mutant were synthesized and purified, and their affinities to the recombinant protein of human EGFR kinase domain were determined by fluorescence anisotropy titration. As expected theoretically, the dephosphorylated peptide has no observable binding to the kinase, and phosphorylation and mutation can confer low and moderate affinities to the peptide, respectively, suggesting a good consistence between the computational

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

    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.

  10. A CLONALLY DERIVED CELL LINE,9L-EGFR IS USEFUL FOR THE STUDIES OF CANCER CELLS BEARING EGF RECEPTOR

    Lin Qi; Rajesh Agarwal; Rana Singh; Gail S. Harrisona; L.Michael Glodea

    2003-01-01

    Since the epidermal growth factor receptor (EGFR) is a key regulator in cell signaling pathways of cancer cell. To investigate the mechanism between cancer cells survival and its EGFR expression, drug selection of cancer cells target therapy, we generated a cell line, 9L-EGFR, which stably expressed human EGFR; the parental rat glioma cell line, 9L, does not contain endogenous EGFR message or protein. Our results show that 9L-EGFR cells had high levels of EGFR on their cell surface by using RT-PCR, Western analysis and Flow cytometry analysis. The EGFR transfected into 9L cells was capable of being activated by EGF, in which either phosphorylated (p-EGFR) or total (EGFR) was showed by Western blot. This investigation may contribute to the further studies of cancer cells bearing EGFR.

  11. Radioresistance of human glioma spheroids and expression of HSP70, p53 and EGFr

    Radiation therapy is routinely prescribed for high-grade malignant gliomas. However, the efficacy of this therapeutic modality is often limited by the occurrence of radioresistance, reflected as a diminished susceptibility of the irradiated cells to undergo cell death. Thus, cells have evolved an elegant system in response to ionizing radiation induced DNA damage, where p53, Hsp70 and/or EGFr may play an important role in the process. In the present study, we investigated whether the content of p53, Hsp70 and EGFr are associated to glioblastoma (GBM) cell radioresistance. Spheroids from U-87MG and MO59J cell lines as well as spheroids derived from primary culture of tumor tissue of one GBM patient (UGBM1) were irradiated (5, 10 and 20 Gy), their relative radioresistance were established and the p53, Hsp70 and EGFr contents were immunohistochemically determined. Moreover, we investigated whether EGFr-phospho-Akt and EGFr-MEK-ERK pathways can induce GBM radioresistance using inhibitors of activation of ERK (PD098059) and Akt (wortmannin). At 5 Gy irradiation UGBM1 and U-87MG spheroids showed growth inhibition whereas the MO59J spheroid was relatively radioresistant. Overall, no significant changes in p53 and Hsp70 expression were found following 5 Gy irradiation treatment in all spheroids studied. The only difference observed in Hsp70 content was the periphery distribution in MO59J spheroids. However, 5 Gy treatment induced a significant increase on the EGFr levels in MO59J spheroids. Furthermore, treatment with inhibitors of activation of ERK (PD098059) and Akt (wortmannin) leads to radiosensitization of MO59J spheroids. These results indicate that the PI3K-Akt and MEK-ERK pathways triggered by EGFr confer GBM radioresistance

  12. EGFR/cell membrane chromatography-online-high performance liquid chromatography/mass spectrometry method for screening EGFR antagonists from Radix Angelicae Pubescentis

    2010-01-01

    The intracellular kinase domains of the epidermal growth factor receptor(EGFR) in some tumor cells are significant targets for drug discovery.We have developed a new EGFR cell membrane chromatography(EGFR/CMC)-online-high performance liquid chromatography/mass spectrometry(HPLC/MS) method for screening anti-EGFR antagonists from medicinal herbs such as Radix Angelicae Pubescentis.In this study,the HEK293 EGFR cells with high expression of EGFR were used to prepare cell membrane stationary phase(CMSP) in the EGFR/CMC model.The retention fractions on the EGFR/CMC model were directly analyzed by combining a 10 port columns switcher with a HPLC/MS system online.As a result,osthole from Radix Angelicae Pubescentis was found to be the active component acting on EGFR like dasatinib as the control drug.There was a good relationship between their inhibiting effects on EGFR secretion and HEK293 EGFR cell growth in vitro.This new EGFR/CMC-online-HPLC/MS method can be applied for screening anti-EGFR antagonists from TCMs,for instance,Radix Angelicae Pubescentis.It will be a useful method for drug discovery with natural medicinal herbs as a leading compound resource.

  13. Ibrutinib selectively and irreversibly targets EGFR (L858R, Del19) mutant but is moderately resistant to EGFR (T790M) mutant NSCLC Cells

    Wu, Hong; Wang, Aoli; Zhang, Wei; Wang, Beilei; Chen, Cheng; Wang, Wenchao; Hu, Chen; Ye, Zi; Zhao, Zheng; Wang, Li; Li, Xixiang; Yu, Kailin; Liu, Juan; Wu, Jiaxin; Yan, Xiao-E

    2015-01-01

    Through comprehensive comparison study, we found that ibrutinib, a clinically approved covalent BTK kinase inhibitor, was highly active against EGFR (L858R, del19) mutant driven NSCLC cells, but moderately active to the T790M ‘gatekeeper’ mutant cells and not active to wild-type EGFR NSCLC cells. Ibrutinib strongly affected EGFR mediated signaling pathways and induced apoptosis and cell cycle arrest (G0/G1) in mutant EGFR but not wt EGFR cells. However, ibrutinib only slowed down tumor progre...

  14. Optimizing the sequence of anti-EGFR-targeted therapy in EGFR-mutant lung cancer.

    Meador, Catherine B; Jin, Hailing; de Stanchina, Elisa; Nebhan, Caroline A; Pirazzoli, Valentina; Wang, Lu; Lu, Pengcheng; Vuong, Huy; Hutchinson, Katherine E; Jia, Peilin; Chen, Xi; Eisenberg, Rosana; Ladanyi, Marc; Politi, Katerina; Zhao, Zhongming; Lovly, Christine M; Cross, Darren A E; Pao, William

    2015-02-01

    Metastatic EGFR-mutant lung cancers are sensitive to the first- and second-generation EGFR tyrosine kinase inhibitors (TKIs) gefitinib, erlotinib, and afatinib, but resistance develops. Acquired resistance to gefitinib or erlotinib occurs most commonly (>50%) via the emergence of a second-site EGFR mutation, T790M. Two strategies to overcome T790M-mediated resistance are dual inhibition of EGFR with afatinib plus the anti-EGFR antibody cetuximab (A+C), or mutant-specific EGFR inhibition with AZD9291. A+C and AZD9291 are now also being tested as first-line therapies, but whether these therapies will extend progression-free survival or induce more aggressive forms of resistance in this setting remains unknown. We modeled resistance to multiple generations of anti-EGFR therapies preclinically to understand the effects of sequential treatment with anti-EGFR agents on drug resistance and determine the optimal order of treatment. Using a panel of erlotinib/afatinib-resistant cells, including a novel patient-derived cell line (VP-2), we found that AZD9291 was more potent than A+C at inhibiting cell growth and EGFR signaling in this setting. Four of four xenograft-derived A+C-resistant cell lines displayed in vitro and in vivo sensitivity to AZD9291, but four of four AZD9291-resistant cell lines demonstrated cross-resistance to A+C. Addition of cetuximab to AZD9291 did not confer additive benefit in any preclinical disease setting. This work, emphasizing a mechanistic understanding of the effects of therapies on tumor evolution, provides a framework for future clinical trials testing different treatment sequences. This paradigm is applicable to other tumor types in which multiple generations of inhibitors are now available. PMID:25477325

  15. MITF Modulates Therapeutic Resistance through EGFR Signaling.

    Ji, Zhenyu; Erin Chen, Yiyin; Kumar, Raj; Taylor, Michael; Jenny Njauw, Ching-Ni; Miao, Benchun; Frederick, Dennie T; Wargo, Jennifer A; Flaherty, Keith T; Jönsson, Göran; Tsao, Hensin

    2015-07-01

    Response to targeted therapies varies significantly despite shared oncogenic mutations. Nowhere is this more apparent than in BRAF (V600E)-mutated melanomas where initial drug response can be striking and yet relapse is commonplace. Resistance to BRAF inhibitors have been attributed to the activation of various receptor tyrosine kinases (RTKs), although the underlying mechanisms have been largely uncharacterized. Here, we found that EGFR-induced vemurafenib resistance is ligand dependent. We employed whole-genome expression analysis and discovered that vemurafenib resistance correlated with the loss of microphthalmia-associated transcription factor (MITF), along with its melanocyte lineage program, and with the activation of EGFR signaling. An inverse relationship between MITF, vemurafenib resistance, and EGFR was then observed in patient samples of recurrent melanoma and was conserved across melanoma cell lines and patients' tumor specimens. Functional studies revealed that MITF depletion activated EGFR signaling and consequently recapitulated the resistance phenotype. In contrast, forced expression of MITF in melanoma and colon cancer cells inhibited EGFR and conferred sensitivity to BRAF/MEK inhibitors. These findings indicate that an "autocrine drug resistance loop" is suppressed by melanocyte lineage signal(s), such as MITF. This resistance loop modulates drug response and could explain the unique sensitivity of melanomas to BRAF inhibition. PMID:25789707

  16. EGFR kinase domain duplication (EGFR-KDD) is a novel oncogenic driver in lung cancer that is clinically responsive to afatinib

    Gallant, Jean-Nicolas; Sheehan, Jonathan H.; Shaver, Timothy M.; Bailey, Mark; Lipson, Doron; Chandramohan, Raghu; Brewer, Monica Red; York, Sally J.; Kris, Mark G.; Pietenpol, Jennifer A.; Ladanyi, Marc; Miller, Vincent A.; Ali, Siraj M.; Meiler, Jens; Lovly, Christine M.

    2015-01-01

    Oncogenic EGFR mutations are found in 10-35% of lung adenocarcinomas. Such mutations, which present most commonly as small in-frame deletions in exon 19 or point mutations in exon 21 (L858R), confer sensitivity to EGFR tyrosine kinase inhibitors (TKIs). In analyzing the tumor from a 33-year-old male never smoker, we identified a novel EGFR alteration in lung cancer: EGFR exon 18-25 kinase domain duplication (EGFR-KDD). Through analysis of a larger cohort of tumor samples, we detected additional cases of EGFR-KDD in lung, brain, and other cancers. In vitro, EGFR-KDD is constitutively active, and computational modeling provides potential mechanistic support for its auto-activation. EGFR-KDD-transformed cells are sensitive to EGFR TKIs and, consistent with these in vitro findings, the index patient had a partial response to the EGFR TKI, afatinib. The patient eventually progressed, at which time, re-sequencing revealed an EGFR-dependent mechanism of acquired resistance to afatinib, thereby validating EGFR-KDD as a driver alteration and therapeutic target. PMID:26286086

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

    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.

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

    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

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

    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. 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. 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. 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

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

    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

    2013-01-01

    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 unkn...

  1. Nuclear EGFR as a molecular target in cancer

    The epidermal growth factor receptor (EGFR) has been one of the most targeted receptors in the field of oncology. While anti-EGFR inhibitors have demonstrated clinical success in specific cancers, most patients demonstrate either intrinsic or acquired resistance within one year of treatment. Many mechanisms of resistance to EGFR inhibitors have been identified, one of these being attributed to alternatively localized EGFR from the cell membrane into the cell’s nucleus. Inside the nucleus, EGFR functions as a co-transcription factor for several genes involved in cell proliferation and angiogenesis, and as a tyrosine kinase to activate and stabilize proliferating cell nuclear antigen and DNA dependent protein kinase. Nuclear localized EGFR is highly associated with disease progression, worse overall survival in numerous cancers, and enhanced resistance to radiation, chemotherapy, and the anti-EGFR therapies gefitinib and cetuximab. In this review the current knowledge of how nuclear EGFR enhances resistance to cancer therapeutics is discussed, in addition to highlighting ways to target nuclear EGFR as an anti-cancer strategy in the future

  2. Nuclear trafficking of EGFR by Vps34 represses Arf expression to promote lung tumor cell survival.

    Dayde, D; Guerard, M; Perron, P; Hatat, A-S; Barrial, C; Eymin, B; Gazzeri, S

    2016-07-28

    Epidermal growth factor receptor (EGFR) is a cell surface receptor that has an essential role in cell proliferation and survival, and overexpression of EGFR is a common feature of human cancers. In Non-small-cell lung cancer (NSCLC), activating mutations of EGFR have also been described. We recently showed that mutant EGFR-L858R inhibits the expression of the p14ARF tumor-suppressor protein to promote cell survival. In this study, we defined the molecular bases by which EGFR controls Arf expression. Using various lung tumor models, we showed that EGF stimulation inhibits Arf transcription by a mechanism involving the nuclear transport and recruitment of EGFR to the Arf promoter. We unraveled the vesicular trafficking protein Vps34 as a mediator of EGFR nuclear trafficking and showed that its neutralization prevents the accumulation of EGFR to the Arf promoter in response to ligand activation. Finally, in lung tumor cells that carry mutant EGFR-L858R, we demonstrated that inhibition of Vps34 using small interfering RNA restrains nuclear EGFR location and restores Arf expression leading to apoptosis. These findings identify the Arf tumor suppressor as a new transcriptional target of nuclear EGFR and highlight Vps34 as an important regulator of the nuclear EGFR/Arf survival pathway. As a whole, they provide a mechanistic explanation to the inverse correlation between nuclear expression of EGFR and overall survival in NSCLC patients. PMID:26686095

  3. DNA methylation down-regulates EGFR expression in chicken

    The epidermal growth factor receptor (EGFR), a growth-factor-receptor tyrosine kinase, was found up-regulated in numerous tumors, which provides a good target for cancer therapy. Although it was documented that oncoviruses are responsible for the activation of EGFR in tumors, the impact of Marek’s d...

  4. Agonist-induced activation of histamine H3 receptor signals to extracellular signal-regulated kinases 1 and 2 through PKC-, PLD-, and EGFR-dependent mechanisms.

    Lai, Xiangru; Ye, Lingyan; Liao, Yuan; Jin, Lili; Ma, Qiang; Lu, Bing; Sun, Yi; Shi, Ying; Zhou, Naiming

    2016-04-01

    The histamine H3 receptor (H3R), abundantly expressed in the central and the peripheral nervous system, has been recognized as a promising target for the treatment of various important CNS diseases including narcolepsy, Alzheimer's disease, and attention deficit hyperactivity disorder. The H3R acts via Gi/o -proteins to inhibit adenylate cyclase activity and modulate MAPK activity. However, the underlying molecular mechanisms for H3R mediation of the activation of extracellular signal-regulated kinases 1 and 2 (ERK1/2) remain to be elucidated. In this study, using HEK293 cells stably expressing human H3R and mouse primary cortical neurons endogenously expressing mouse H3R, we found that the H3R-mediated activation of ERK1/2 was significantly blocked by both the pertussis toxin and the MEK1/2 inhibitor U0126. Upon stimulation by H3R agonist histamine or imetit, H3R was shown to rapidly induce ERK1/2 phosphorylation via PLC/PKC-, PLDs-, and epidermal growth factor receptor (EGFR) transactivation-dependent pathways. Furthermore, it was also indicated that while the βγ-subunits play a key role in H3R-activated ERK1/2 phosphorylation, β-arrestins were not required for ERK1/2 activation. In addition, when the cultured mouse cortical neurons were exposed to oxygen and glucose deprivation conditions (OGD), imetit exhibited neuroprotective properties through the H3R. Treatment of cells with the inhibitor UO126 abolished these protective effects. This suggests a possible neuroprotective role of the H3R-mediated ERK1/2 pathway under hypoxia conditions. These observations may provide new insights into the pharmacological effects and the physiological functions modulated by the H3R-mediated activation of ERK1/2. Histamine H3 receptors are abundantly expressed in the brain and play important roles in various CNS physiological functions. However, the underlying mechanisms for H3R-induced activation of extracellular signal-regulated kinase (ERK)1/2 remain largely unknown. Here

  5. Dermatologic Toxicities from Monoclonal Antibodies and Tyrosine Kinase Inhibitors against EGFR: Pathophysiology and Management

    Shaad E. Abdullah; Missak Haigentz; Bilal Piperdi

    2012-01-01

    Epidermal growth factor receptor (EGFR) inhibition has now been well established as an effective treatment for various cancers. The EGFR belongs to the ErbB family of tyrosine kinase receptors which regulate tumor cell differentiation, survival and proliferation. Activation of EGFR drives tumorigenesis in lung, head and neck, colorectal and pancreatic cancers. Irrespective of the type of cancer being treated and the mechanism by which tumor EGFR drives tumorigenesis, the major side effect of ...

  6. Relationship between EGFR expression, copy number and mutation in lung adenocarcinomas

    This study was designed to investigate EGFR protein expression, EGFR copy number and EGFR mutations in lung adenocarcinomas, to explore the relationship of the three markers. EGFR status was analyzed in surgically resected lung adenocarcinoma samples from 133 Chinese patients by three methods: protein expression (n = 133) by standardized immunohistochemistry (IHC), gene copy number (n = 133) by fluorescence in situ hybridization (FISH), and mutation analysis using the Scorpion amplification refractory mutation system (ARMS) (n = 133). The results showed that 68.4% of the samples were positive by IHC, 42.1% were positive by FISH, and 63.9% contained activating kinase domain mutations. EGFR mutations were more frequent in non-smoking patients (p = 0.008), and EGFR mutations were associated with EGFR FISH positivity (p < 0.0001). When using 10% positivity and 2+ as cutoffs, EGFR protein expression was significantly correlated with EGFR FISH positivity (p = 0.012) and EGFR mutations (p = 0.008) after Bonferroni correction. EGFR protein expression, EGFR copy number and EGFR mutations were closely related to each other. Standard methods and interpretation criteria need to be established

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

    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

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

    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

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

    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

  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.

    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

    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. JAK2 inhibition sensitizes resistant EGFR-mutant lung adenocarcinoma to tyrosine kinase inhibitors.

    Gao, Sizhi P; Chang, Qing; Mao, Ninghui; Daly, Laura A; Vogel, Robert; Chan, Tyler; Liu, Shu Hui; Bournazou, Eirini; Schori, Erez; Zhang, Haiying; Red Brewer, Monica; Pao, William; Morris, Luc; Ladanyi, Marc; Arcila, Maria; Manova-Todorova, Katia; de Stanchina, Elisa; Norton, Larry; Levine, Ross L; Altan-Bonnet, Gregoire; Solit, David; Zinda, Michael; Huszar, Dennis; Lyden, David; Bromberg, Jacqueline F

    2016-01-01

    Lung adenocarcinomas with mutant epidermal growth factor receptor (EGFR) respond to EGFR-targeted tyrosine kinase inhibitors (TKIs), but resistance invariably occurs. We found that the Janus kinase (JAK)/signal transduction and activator of transcription 3 (STAT3) signaling pathway was aberrantly increased in TKI-resistant EGFR-mutant non-small cell lung cancer (NSCLC) cells. JAK2 inhibition restored sensitivity to the EGFR inhibitor erlotinib in TKI-resistant cell lines and xenograft models of EGFR-mutant TKI-resistant lung cancer. JAK2 inhibition uncoupled EGFR from its negative regulator, suppressor of cytokine signaling 5 (SOCS5), consequently increasing EGFR abundance and restoring the tumor cells' dependence on EGFR signaling. Furthermore, JAK2 inhibition led to heterodimerization of mutant and wild-type EGFR subunits, the activity of which was then blocked by TKIs. Our results reveal a mechanism whereby JAK2 inhibition overcomes acquired resistance to EGFR inhibitors and support the use of combination therapy with JAK and EGFR inhibitors for the treatment of EGFR-dependent NSCLC. PMID:27025877

  12. A Novel Technique to Detect EGFR Mutations in Lung Cancer.

    Liu, Yuanbin; Lei, Ting; Liu, Zhiyu; Kuang, Yanbin; Lyu, Jianxin; Wang, Qi

    2016-01-01

    Epidermal growth factor receptor (EGFR) gene mutations occur in multiple human cancers; therefore, the detection of EGFR mutations could lead to early cancer diagnosis. This study describes a novel EGFR mutation detection technique. Compared to direct DNA sequencing detection methods, this method is based on allele-specific amplification (ASA), recombinase polymerase amplification (RPA), peptide nucleic acid (PNA), and SYBR Green I (SYBR), referred to as the AS-RPA-PNA-SYBR (ARPS) system. The principle of this technique is based on three continuous steps: ASA or ASA combined with PNA to prevent non-target sequence amplification (even single nucleotide polymorphisms, SNPs), the rapid amplification advantage of RPA, and appropriate SYBR Green I detection (the samples harboring EGFR mutations show a green signal). Using this method, the EGFR 19Del(2) mutation was detected in 5 min, while the EGFR L858R mutation was detected in 10 min. In this study, the detection of EGFR mutations in clinical samples using the ARPS system was compatible with that determined by polymerase chain reaction (PCR) and DNA sequencing methods. Thus, this newly developed methodology that uses the ARPS system with appropriate primer sets is a rapid, reliable, and practical way to assess EGFR mutations in clinical samples. PMID:27223277

  13. A Novel Technique to Detect EGFR Mutations in Lung Cancer

    Liu, Yuanbin; Lei, Ting; Liu, Zhiyu; Kuang, Yanbin; Lyu, Jianxin; Wang, Qi

    2016-01-01

    Epidermal growth factor receptor (EGFR) gene mutations occur in multiple human cancers; therefore, the detection of EGFR mutations could lead to early cancer diagnosis. This study describes a novel EGFR mutation detection technique. Compared to direct DNA sequencing detection methods, this method is based on allele-specific amplification (ASA), recombinase polymerase amplification (RPA), peptide nucleic acid (PNA), and SYBR Green I (SYBR), referred to as the AS-RPA-PNA-SYBR (ARPS) system. The principle of this technique is based on three continuous steps: ASA or ASA combined with PNA to prevent non-target sequence amplification (even single nucleotide polymorphisms, SNPs), the rapid amplification advantage of RPA, and appropriate SYBR Green I detection (the samples harboring EGFR mutations show a green signal). Using this method, the EGFR 19Del(2) mutation was detected in 5 min, while the EGFR L858R mutation was detected in 10 min. In this study, the detection of EGFR mutations in clinical samples using the ARPS system was compatible with that determined by polymerase chain reaction (PCR) and DNA sequencing methods. Thus, this newly developed methodology that uses the ARPS system with appropriate primer sets is a rapid, reliable, and practical way to assess EGFR mutations in clinical samples. PMID:27223277

  14. Consensus for EGFR mutation testing in non-small cell lung cancer: results from a European workshop

    Pirker, Robert; Herth, Felix J F; Kerr, Keith M; Filipits, Martin; Taron, Miquel; Gandara, David; Hirsch, Fred R; Grunenwald, Dominique; Popper, Helmut; Smit, Egbert; Dietel, Manfred; Marchetti, Antonio; Manegold, Christian; Schirmacher, Peter; Thomas, Michael; Rosell, Rafael; Cappuzzo, Federico; Stahel, Rolf; de Stricker, Karin

    2010-01-01

    Activating somatic mutations of the tyrosine kinase domain of epidermal growth factor receptor (EGFR) have recently been characterized in a subset of patients with advanced non-small cell lung cancer (NSCLC). Patients harboring these mutations in their tumors show excellent response to EGFR...... tyrosine kinase inhibitors (EGFR-TKIs). The EGFR-TKI gefitinib has been approved in Europe for the treatment of adult patients with locally advanced or metastatic NSCLC with activating mutations of the EGFR TK. Because EGFR mutation testing is not yet well established across Europe, biomarker...

  15. A fully automated two-step synthesis of an {sup 18}F-labelled tyrosine kinase inhibitor for EGFR kinase activity imaging in tumors

    Kobus, D.; Giesen, Y.; Ullrich, R.; Backes, H. [Max Planck Institute for Neurological Research with Klaus-Joachim-Zuelch Laboratories of the Max Planck Society and the Faculty of Medicine of the University of Cologne, Cologne (Germany); Neumaier, B. [Max Planck Institute for Neurological Research with Klaus-Joachim-Zuelch Laboratories of the Max Planck Society and the Faculty of Medicine of the University of Cologne, Cologne (Germany)], E-mail: bernd.neumaier@nf.mpg.de

    2009-11-15

    Radiolabelled epidermal growth factor receptor (EGFR) tyrosine kinase (TK) inhibitors potentially facilitate the assessment of EGFR overexpression in tumors. Since elaborate multi-step radiosyntheses are required for {sup 18}F-labelling of EGFR-specific anilinoquinazolines we report on the development of a two-step click labelling approach that was adapted to a fully automated synthesis module. 6-(4-N,N-Dimethylaminocrotonyl)amido-4-(3-chloro-4-fluoro)phenylamino-7-{l_brace}3- [4-(2-[{sup 18}F]fluoroethyl)-2,3,4-triazol-1-yl]propoxy{r_brace}quinazoline ([{sup 18}F]6) was synthesized via Huisgen 1,3-dipolar cycloaddition between 2-[{sup 18}F]fluoroethylazide ([{sup 18}F]4) and the alkyne modified anilinoquinazoline precursor 5. PET images of PC9 tumor xenograft using the novel biomarker showed promising results to visualize EGFR overexpression.

  16. A fully automated two-step synthesis of an 18F-labelled tyrosine kinase inhibitor for EGFR kinase activity imaging in tumors

    Radiolabelled epidermal growth factor receptor (EGFR) tyrosine kinase (TK) inhibitors potentially facilitate the assessment of EGFR overexpression in tumors. Since elaborate multi-step radiosyntheses are required for 18F-labelling of EGFR-specific anilinoquinazolines we report on the development of a two-step click labelling approach that was adapted to a fully automated synthesis module. 6-(4-N,N-Dimethylaminocrotonyl)amido-4-(3-chloro-4-fluoro)phenylamino-7-{3- [4-(2-[18F]fluoroethyl)-2,3,4-triazol-1-yl]propoxy}quinazoline ([18F]6) was synthesized via Huisgen 1,3-dipolar cycloaddition between 2-[18F]fluoroethylazide ([18F]4) and the alkyne modified anilinoquinazoline precursor 5. PET images of PC9 tumor xenograft using the novel biomarker showed promising results to visualize EGFR overexpression.

  17. Therapeutic resistance in cancer: microRNA regulation of EGFR signaling networks

    Receptor tyrosine kinases (RTKs) such as the epidermal growth factor receptor (EGFR) regulate cellular homeostatic processes. EGFR activates downstream signaling cascades that promote tumor cell survival, proliferation and migration. Dysregulation of EGFR signaling as a consequence of overexpression, amplification and mutation of the EGFR gene occurs frequently in several types of cancers and many become dependent on EGFR signaling to maintain their malignant phenotypes. Consequently, concerted efforts have been mounted to develop therapeutic agents and strategies to effectively inhibit EGFR. However, limited therapeutic benefits to cancer patients have been derived from EGFR-targeted therapies. A well-documented obstacle to improved patient survival is the presence of EGFR-inhibitor resistant tumor cell variants within heterogeneous tumor cell masses. Here, we summarize the mechanisms by which tumors resist EGFR-targeted therapies and highlight the emerging role of microRNAs (miRs) as downstream effector molecules utilized by EGFR to promote tumor initiation, progression and that play a role in resistance to EGFR inhibitors. We also examine evidence supporting the utility of miRs as predictors of response to targeted therapies and novel therapeutic agents to circumvent EGFR-inhibitor resistance mechanisms

  18. EGFR Expression in Gallbladder Carcinoma in North America

    Matthew Kaufman, Bhoomi Mehrotra, Sewanti Limaye, Sherrie White, Alexander Fuchs, Yehuda Lebowicz, Sandy Nissel-Horowitz, Adrienne Thomas

    2008-01-01

    Full Text Available BACKGROUND: Increased epidermal growth factor receptor (EGF receptor expression has been noted in various cancers and has become a useful target for therapeutic interventions. Small studies from Asia and Australia have demonstrated EGFR over-expression in gallbladder cancer. We sought to evaluate the expression of EGFR in a series of 16 gallbladder cancer patients from North America. METHODS: Using tumor registry data, we identified 16 patients diagnosed with gall bladder carcinoma at our medical center between the years of 1998 and 2005. We performed a retrospective review of these patients' charts, obtained cell blocks from pathology archives and stained for EGFR and Her2/neu. RESULTS: Fifteen of sixteen patients were noted to over-express EGFR. Three were determined 1+, nine were 2+ and three were 3+. Eight patients had poorly differentiated adenocarcinoma, six had moderately differentiated and two had well-differentiated tumors. In this small series, there was a trend toward shorter survival and more poorly differentiated tumors in patients with greater intensity of EGFR expression. One patient was EGFR negative but 3+ for erb-2/Her 2-neu expression. No patient co-expressed EGFR and Her-2-neu. Median survival of patients in this series was 17 months. CONCLUSION: In view of our observations confirming the over-expression of EGFR in our patient population in North America, and the recent success of EGFR targeted therapies in other solid tumors that over-express EGFR, it may now be appropriate to evaluate agents targeting this pathway either as single agents or in combination with standard chemotherapy.

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

    Meng Sun; Yan-min Zhang; Jie Zhang; Si-cen Wang; Lang-chong He

    2011-01-01

    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...

  20. Epidermal Growth Factor Receptor (EGFR) mutation analysis, gene expression profiling and EGFR protein expression in primary prostate cancer

    Activating mutations of the epidermal growth factor receptor (EGFR) confer sensitivity to the tyrosine kinase inhibitors (TKi), gefitinib and erlotinib. We analysed EGFR expression, EGFR mutation status and gene expression profiles of prostate cancer (PC) to supply a rationale for EGFR targeted therapies in this disease. Mutational analysis of EGFR TK domain (exons from 18 to 21) and immunohistochemistry for EGFR were performed on tumour tissues derived from radical prostatectomy from 100 PC patients. Gene expression profiling using oligo-microarrays was also carried out in 51 of the PC samples. EGFR protein overexpression (EGFRhigh) was found in 36% of the tumour samples, and mutations were found in 13% of samples. Patients with EGFRhigh tumours experienced a significantly increased risk of biochemical relapse (hazard ratio-HR 2.52, p=0.02) compared with patients with tumours expressing low levels of EGFR (EGFRlow). Microarray analysis did not reveal any differences in gene expression between EGFRhigh and EGFRlow tumours. Conversely, in EGFRhigh tumours, we were able to identify a 79 gene signature distinguishing mutated from non-mutated tumours. Additionally, 29 genes were found to be differentially expressed between mutated/EGFRhigh (n=3) and mutated/EGFRlow tumours (n=5). Four of the down-regulated genes, U19/EAF2, ABCC4, KLK3 and ANXA3 and one of the up-regulated genes, FOXC1, are involved in PC progression. Based on our findings, we hypothesize that accurate definition of the EGFR status could improve prognostic stratification and we suggest a possible role for EGFR-directed therapies in PC patients. Having been generated in a relatively small sample of patients, our results warrant confirmation in larger series

  1. EGFR soluble isoforms and their transcripts are expressed in meningiomas.

    Guillaudeau, Angélique; Durand, Karine; Bessette, Barbara; Chaunavel, Alain; Pommepuy, Isabelle; Projetti, Fabrice; Robert, Sandrine; Caire, François; Rabinovitch-Chable, Hélène; Labrousse, François

    2012-01-01

    The EGFR (epidermal growth factor receptor) is involved in the oncogenesis of many tumors. In addition to the full-length EGFR (isoform a), normal and tumor cells produce soluble EGFR isoforms (sEGFR) that lack the intracellular domain. sEGFR isoforms b, c and d are encoded by EGFR variants 2 (v2), 3 (v3) and 4 (v4) mRNA resulting from gene alternative splicing. Accordingly, the results of EGFR protein expression analysis depend on the domain targeted by the antibodies. In meningiomas, EGFR expression investigations mainly focused on EGFR isoform a. sEGFR and EGFRvIII mutant, that encodes a constitutively active truncated receptor, have not been studied. In a 69 meningiomas series, protein expression was analyzed by immunohistochemistry using extracellular domain targeted antibody (ECD-Ab) and intracellular domain targeted antibody (ICD-Ab). EGFRv1 to v4 and EGFRvIII mRNAs were quantified by RT-PCR and EGFR amplification revealed by MLPA. Results were analyzed with respect to clinical data, tumor resection (Simpson grade), histological type, tumor grade, and patient outcome.Immunochemical staining was stronger with ECD-Ab than with ICD-Ab. Meningiomas expressed EGFRv1 to -v4 mRNAs but not EGFRvIII mutant. Intermediate or high ECD-Ab staining and high EGFRv1 to v4 mRNA levels were associated to a better progression free survival (PFS). PFS was also improved in women, when tumor resection was evaluated as Simpson 1 or 2, in grade I vs. grade II and III meningiomas and when Ki67 labeling index was lower than 10%. Our results suggest that, EGFR protein isoforms without ICD and their corresponding mRNA variants are expressed in meningiomas in addition to the whole isoform a. EGFRvIII was not expressed. High expression levels seem to be related to a better prognosis. These results indicate that the oncogenetic mechanisms involving the EGFR pathway in meningiomas could be different from other tumor types. PMID:22623992

  2. EGFR soluble isoforms and their transcripts are expressed in meningiomas.

    Angélique Guillaudeau

    Full Text Available The EGFR (epidermal growth factor receptor is involved in the oncogenesis of many tumors. In addition to the full-length EGFR (isoform a, normal and tumor cells produce soluble EGFR isoforms (sEGFR that lack the intracellular domain. sEGFR isoforms b, c and d are encoded by EGFR variants 2 (v2, 3 (v3 and 4 (v4 mRNA resulting from gene alternative splicing. Accordingly, the results of EGFR protein expression analysis depend on the domain targeted by the antibodies. In meningiomas, EGFR expression investigations mainly focused on EGFR isoform a. sEGFR and EGFRvIII mutant, that encodes a constitutively active truncated receptor, have not been studied. In a 69 meningiomas series, protein expression was analyzed by immunohistochemistry using extracellular domain targeted antibody (ECD-Ab and intracellular domain targeted antibody (ICD-Ab. EGFRv1 to v4 and EGFRvIII mRNAs were quantified by RT-PCR and EGFR amplification revealed by MLPA. Results were analyzed with respect to clinical data, tumor resection (Simpson grade, histological type, tumor grade, and patient outcome.Immunochemical staining was stronger with ECD-Ab than with ICD-Ab. Meningiomas expressed EGFRv1 to -v4 mRNAs but not EGFRvIII mutant. Intermediate or high ECD-Ab staining and high EGFRv1 to v4 mRNA levels were associated to a better progression free survival (PFS. PFS was also improved in women, when tumor resection was evaluated as Simpson 1 or 2, in grade I vs. grade II and III meningiomas and when Ki67 labeling index was lower than 10%. Our results suggest that, EGFR protein isoforms without ICD and their corresponding mRNA variants are expressed in meningiomas in addition to the whole isoform a. EGFRvIII was not expressed. High expression levels seem to be related to a better prognosis. These results indicate that the oncogenetic mechanisms involving the EGFR pathway in meningiomas could be different from other tumor types.

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

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

    2016-01-01

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

  4. Nuclear EGFR contributes to acquired resistance to cetuximab.

    Li, C; Iida, M; Dunn, E F; Ghia, A J; Wheeler, D L

    2009-10-29

    Epidermal growth factor receptor (EGFR) is a ubiquitously expressed receptor tyrosine kinase involved in the etiology of several human cancers. Cetuximab is an EGFR-blocking antibody that has been approved for the treatment of patients with head and neck squamous cell carcinoma and metastatic colorectal cancer. Previous reports have shown that EGFR translocation to the nucleus is associated with cell proliferation. Here we investigated mechanisms of acquired resistance to cetuximab using a model derived from the non-small cell lung cancer line H226. We demonstrated that cetuximab-resistant cells overexpress HER family ligands including epidermal growth factor (EGF), amphiregulin, heparin-binding EGF and beta-cellulin. Overexpression of these ligands is associated with the nuclear translocation of the EGFR and this process was mediated by the Src family kinases (SFK). Treatment of cetuximab-resistant cells with the SFK inhibitor, dasatinib, resulted in loss of nuclear EGFR, increased membrane expression of the EGFR and resensitization to cetuximab. In addition, expression of a nuclear localization sequence-tagged EGFR in cetuximab-sensitive cells increased resistance to cetuximab both in vitro and in mouse xenografts. Collectively, these data suggest that nuclear expression of EGFR may be an important molecular determinant of resistance to cetuximab therapy and provides a rationale for investigating nuclear EGFR as a biomarker for cetuximab response. Further, these data suggest a rationale for the design of clinical trials that examine the value of treating patients with cetuximab-resistant tumors with inhibitors of SFKs in combination with cetuximab. PMID:19684613

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

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

  6. Epidermal Growth Factor Receptor (EGFR) Crosstalks in Liver Cancer

    Hepatocarcinogenesis is a complex multistep process in which many different molecular pathways have been implicated. Hepatocellular carcinoma (HCC) is refractory to conventional chemotherapeutic agents, and the new targeted therapies are meeting with limited success. Interreceptor crosstalk and the positive feedback between different signaling systems are emerging as mechanisms of targeted therapy resistance. The identification of such interactions is therefore of particular relevance to improve therapeutic efficacy. Among the different signaling pathways activated in hepatocarcinogenesis the epidermal growth factor receptor (EGFR) system plays a prominent role, being recognized as a “signaling hub” where different extracellular growth and survival signals converge. EGFR can be transactivated in response to multiple heterologous ligands through the physical interaction with multiple receptors, the activity of intracellular kinases or the shedding of EGFR-ligands. In this article we review the crosstalk between the EGFR and other signaling pathways that could be relevant to liver cancer development and treatment

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

    Wang, Shuhang; Cang, Shundong; Liu, Delong

    2016-01-01

    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/...

  8. EGFR: The Paradigm of an Oncogene-Driven Lung Cancer

    Riely, Gregory J.; Yu, Helena A.

    2015-01-01

    Somatic, activating mutations in Epidermal Growth Factor Receptor (EGFR) identify a significant minority of patients with non-small cell lung cancer (NSCLC). While these mutations are associated with an ~70% response rate to some EGFR tyrosine kinase inhibitors (gefitinib, erlotinib, and afatinib), patients develop resistance (i.e. “acquired resistance”) after a median of 9–12 months. In patients with clinical acquired resistance, repeat biopsy of tumors has identified a number of relevant me...

  9. EGFR Tyrosine kinase regulates small conductance Ca2+-activated K+ (hSKCa1) channels expressed in HEK 293 cells

    Wu, W.; H. Sun; Deng, XL; Li, GR

    2013-01-01

    SKCa (small-conductance Ca(2+)-activated K(+)) channels are widely distributed in different tissues, including the brain, pancreatic islets and myocardium and play an important role in controlling electrical activity and cellular functions. However, intracellular signal modulation of SKCa channels is not fully understood. The present study was designed to investigate the potential regulation of hSKCa1 (human SKCa1) channels by PTKs (protein tyrosine kinases) in HEK (human embryonic kidney)-29...

  10. Ezrin Enhances EGFR Signaling and Modulates Erlotinib Sensitivity in Non–Small Cell Lung Cancer Cells

    Yasemin Saygideğer-Kont

    2016-02-01

    Full Text Available Ezrin is a scaffolding protein that is involved in oncogenesis by linking cytoskeletal and membrane proteins. Ezrin interacts with epidermal growth factor receptor (EGFR in the cell membrane, but little is known about the effects of this interaction on EGFR signaling pathway. In this study, we established the biological and functional significance of ezrin-EGFR interaction in non–small cell lung cancer (NSCLC cells. Endogenous ezrin and EGRF interaction was confirmed by co-immunoprecipitation and immunofluorescent staining. When expression of ezrin was inhibited, EGFR activity and phosphorylation levels of downstream signaling pathway proteins ERK and STAT3 were decreased. Cell fractionation experiments revealed that nuclear EGFR was significantly diminished in ezrin-knockdown cells. Consequently, mRNA levels of EGFR target genes AURKA, COX-2, cyclin D1, and iNOS were decreased in ezrin-depleted cells. A small molecule inhibitor of ezrin, NSC305787, reduced EGF-induced phosphorylation of EGFR and downstream target proteins, EGFR nuclear translocation, and mRNA levels of nuclear EGFR target genes similar to ezrin suppression. NSC305787 showed synergism with erlotinib in wild-type EGFR-expressing NSCLC cells, whereas no synergy was observed in EGFR-null cells. Phosphorylation of ezrin on Y146 was found as an enhancer of ezrin-EGFR interaction and required for increased proliferation, colony formation, and drug resistance to erlotinib. These findings suggest that ezrin-EGFR interaction augments oncogenic functions of EGFR and that targeting ezrin may provide a potential novel approach to overcome erlotinib resistance in NSCLC cells.

  11. Impact of EGFR mutation detection methods on the efficacy of erlotinib in patients with advanced EGFR-wild type lung adenocarcinoma.

    Jeng-Sen Tseng

    Full Text Available INTRODUCTION: Methods used for epidermal growth factor receptor (EGFR mutation testing vary widely. The impact of detection methods on the rates of response to EGFR-tyrosine kinase inhibitors (TKIs in EGFR-wild type (wt lung adenocarcinoma patients is unknown. METHODS: We recruited the Group-I patients to evaluate the efficacy of erlotinib in patients with EGFR-wt lung adenocarcinoma by either direct sequencing (DS or mutant type-specific sensitive (MtS methods in six medical centers in Taiwan. Cross recheck of EGFR mutations was performed in patients who achieved objective response to erlotinib and had adequate specimens. The independent Group-II lung adenocarcinoma patients whose EGFR mutation status determined by DS were recruited to evaluate the potential limitations of three MtS methods. RESULTS: In Group-I analysis, 38 of 261 EGFR-wt patients (14.6% achieved partial response to erlotinib treatment. Nineteen patients (50.0% had adequate specimens for cross recheck of EGFR mutations and 10 of them (52.6% had changes in EGFR mutation status, 5 in 10 by DS and 5 in 9 by MtS methods originally. In Group-II analysis, 598 of 996 lung adenocarcinoma patients (60.0% had detectable EGFR mutations. The accuracy rates of the three MtS methods, MALDI-TOF MS, Scorpions ARMS and Cobas, were 87.8%, 86.8% and 85.8%, respectively. CONCLUSIONS: A significant portion of the erlotinib responses in EGFR-wt lung adenocarcinoma patients were related to the limitations of detection methods, not only DS but also MtS methods with similar percentages. Prospective studies are needed to define the proper strategy for EGFR mutation testing.

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

    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.

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

    Jorge, S E D C; Kobayashi, S S; Costa, D B

    2014-11-01

    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. PMID:25296354

  14. Treatment approaches for EGFR-inhibitor-resistant patients with non-small-cell lung cancer.

    Tan, Chee-Seng; Gilligan, David; Pacey, Simon

    2015-09-01

    Discovery of activating mutations in EGFR and their use as predictive biomarkers to tailor patient therapy with EGFR tyrosine kinase inhibitors (TKIs) has revolutionised treatment of patients with advanced EGFR-mutant non-small-cell lung cancer (NSCLC). At present, first-line treatment with EGFR TKIs (gefitinib, erlotinib, and afatinib) has been approved for patients harbouring exon 19 deletions or exon 21 (Leu858Arg) substitution EGFR mutations. These agents improve response rates, time to progression, and overall survival. Unfortunately, patients develop resistance, limiting patient benefit and posing a challenge to oncologists. Optimum treatment after progression is not clearly defined. A more detailed understanding of the biology of EGFR-mutant NSCLC and the mechanisms of resistance to targeted therapy mean that an era of treatment approaches based on rationally developed drugs or therapeutic strategies has begun. Combination approaches-eg, dual EGFR blockade-to overcome resistance have been trialled and seem to be promising but are potentially limited by toxicity. Third-generation EGFR-mutant-selective TKIs, such as AZD9291 or rociletininb, which target Thr790Met-mutant tumours, the most common mechanism of EGFR TKI resistance, have entered clinical trials, and exciting, albeit preliminary, efficacy data have been reported. In this Review, we summarise the scientific literature and evidence on therapy options after EGFR TKI treatment for patients with NSCLC, aiming to provide a guide to oncologists, and consider how to maximise therapeutic advances in outcomes in this rapidly advancing area. PMID:26370354

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

    S.E.D.C. Jorge

    2014-11-01

    Full Text Available 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.

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

    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

  17. Targeting EGFR for Treatment of Glioblastoma: Molecular Basis to Overcome Resistance

    Taylor, Tiffany E.; Furnari, Frank B.; Cavenee, Webster K.

    2012-01-01

    Glioblastoma (glioblastoma multiforme; GBM; WHO Grade IV) accounts for the majority of primary malignant brain tumors in adults. Amplification and mutation of the epidermal growth factor receptor (EGFR) gene represent signature genetic abnormalities encountered in GBM. A range of potential therapies that target EGFR or its mutant constitutively active form, ΔEGFR, including tyrosine kinase inhibitors (TKIs), monoclonal antibodies, vaccines, and RNA-based agents, are currently in development o...

  18. Optimizing the sequence of anti-EGFR targeted therapy in EGFR-mutant lung cancer

    Meador, Catherine B.; Jin, Hailing; de Stanchina, Elisa; Nebhan, Caroline A.; Pirazzoli, Valentina; Wang, Lu; Lu, Pengcheng; Vuong, Huy; Hutchinson, Katherine E.; Jia, Peilin; Chen, Xi; Eisenberg, Rosana; Ladanyi, Marc; Politi, Katerina; Zhao, Zhongming

    2014-01-01

    Metastatic EGFR-mutant lung cancers are sensitive to the first- and second- generation EGFR tyrosine kinase inhibitors (TKIs), gefitinib, erlotinib, and afatinib, but resistance develops. Acquired resistance (AR) to gefitinib or erlotinib occurs most commonly (>50%) via the emergence of a second-site EGFR mutation, T790M. Two strategies to overcome T790M-mediated resistance are dual inhibition of EGFR with afatinib plus the anti-EGFR antibody, cetuximab (A+C), or mutant-specific EGFR inhibiti...

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

    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.

  20. p38 MAPK-induced MDM2 degradation confers paclitaxel resistance through p53-mediated regulation of EGFR in human lung cancer cells

    Park, Shin-Hyung; Seong, Myeong-A; Lee, Ho-Young

    2016-01-01

    Paclitaxel (PTX) is a chemotherapeutic agent that is used to treat a variety of cancers, including non-small cell lung cancer (NSCLC). However, the emergence of drug resistance limits the utility of PTX. This study determined the signaling pathway that contributes to PTX resistance. We first established PTX resistant cell lines (H460/R and 226B/R) using a dose-escalating maintenance of PTX. We found that p38 MAPK and epidermal growth factor receptor (EGFR) were constitutively activated in these cell lines. The inhibition of p38 MAPK activity by SB203580 treatment or the transfection of dominant-negative p38 MAPK sensitized both cell lines to PTX treatment. Erlotinib, an EGFR inhibitor, also increased PTX-induced apoptosis in PTX resistant cells, which suggests a role for p38 MAPK and EGFR in the development of PTX resistance. We demonstrated that p38 MAPK enhanced EGFR expression via the induction of the rapid degradation of mouse double-minute 2 homolog (MDM2) and the consequent stabilization of p53, a transcription factor of EGFR. These results suggest for the first time that the p38 MAPK/p53/EGFR axis is crucial for the facilitation of PTX resistance in NSCLCs. We also propose a mechanism for the role of the tumor-suppressor p53 in drug resistance. These results provide a foundation for the future development of potential therapeutic strategies to regulate the p38 MAPK/p53/EGFR pathway for the treatment of lung cancer patients with PTX resistance. PMID:26799187

  1. The Potential Value of EGFR and P53 Immunostaining in Tumors of the Urinary Bladder

    Ibrahim N

    2009-01-01

    Full Text Available The expression of EGFR and p53 has not been adequately studied as a prognostic tool in urinary bladder tumors. We analyzed 74 bladder cancer samples from Egypt for EGFR and p53 expression using immunohistochemistry. The tumors were of different histological types, grades and clinical stages, and with established lymph node status. Almost 61% of the tumors showed positive membranous EGFR expression and 74.3% had positive nuclear staining of p53. Analysis of correlation of the IHC staining with clinical variables showed a significant correlation only between EGFR expression and histological type (p=0.002, ANOVA, in that the expression was higher in squamous cell carcinomas than in other histological types. There were no significant correlations between p53 or EGFR with the other clinicopathological variables, including age, sex, staging, grading, and lymph node status. Further studies are needed to determine if EGFR and p53 might be used as prognostic tools in bladder cancer.

  2. The Next Wave of EGFR Tyrosine Kinase Inhibitors Enter the Clinic.

    Politi, Katerina; Ayeni, Deborah; Lynch, Thomas

    2015-06-01

    The T790M mutation in EGFR accounts for approximately half of all lung cancer cases with acquired resistance to the current clinical EGFR tyrosine kinase inhibitors. In tyrosine kinase inhibitor-resistant lung tumors, rociletinib and AZD9291 are highly active when T790M is present and modestly active when T790M is absent. PMID:26058074

  3. Advances in the management of acquired resistance to EGFR-TKI in non-small cell lung cancer

    Fei Zhou; Caicun Zhou

    2015-01-01

    Drugs that specifical y target the tyrosine kinase domain of epidermal growth factor receptor (EGFR), such as erlotinib or gefitinib, have exhibited striking ef icacy in non-smal cel lung cancer (NSCLC) patients har-boring activating EGFR mutations. However, acquired resistance inevitably develops and remains a serious barrier for the successful management of patients with this disease. Multiple mechanisms are reportedly involved in the process of acquired resistance, which provide new insights into the management of EGFR-tyrosine kinase inhibitor (EGFR-TKI) resistance. Here, we provide an overview of the emerging treatment approaches for patients with EGFR-TKI resistance.

  4. Maintenance of EGFR and EGFRvIII expressions in an in vivo and in vitro model of human glioblastoma multiforme

    Stockhausen, Marie-Thérése; Broholm, Helle; Villingshøj, Mette; Kirchhoff, Maria; Gerdes, Tommy; Kristoffersen, Karina; Kosteljanetz, Michael; Spang-Thomsen, Mogens; Poulsen, Hans Skovgaard

    2011-01-01

    Glioblastoma multiforme (GBM) is the most common, and most aggressive primary brain tumor among adults. A vast majority of the tumors express high levels of the epidermal growth factor receptor (EGFR) as a consequence of gene amplification. Furthermore, gene amplification is often associated with...... mutation of EGFR, and the constitutive activated deletion variant EGFRvIII is the most common EGFR mutation found in GBM. Activated EGFR signaling, through overexpression and/or mutation, is involved in increased tumorigenic potential. As such, EGFR is an attractive target for GBM therapy. However......, clinical studies with EGFR inhibitors have shown inconsistent results, and as such, further knowledge regarding the role of EGFR and EGFRvIII in GBM is needed. For this, an appropriate in vivo/in vitro tumor model is required. Here, we report the establishment of an experimental GBM model in which the...

  5. Changes in sebum levels and the development of acneiform rash in patients with non–small cell lung cancer after treatment with EGFR inhibitors

    Nakahara T

    2015-01-01

    Full Text Available Takeshi Nakahara,1,2 Yoichi Moroi,2 Koichi Takayama,3 Eriko Itoh,1,2 Makiko Kido-Nakahara,2 Yoichi Nakanishi,3 Masutaka Furue2 1Division of Skin Surface Sensing, 2Department of Dermatology, 3Research Institute for Diseases of the Chest, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan Background: It has recently been shown that patients treated with epidermal growth factor receptor (EGFR inhibitors often develop various cutaneous adverse events. While the pathogenesis underlying these events remains unclear, the relationship between skin toxicity induced by EGFR inhibitors and the sebaceous glands that express EGFR has been previously reported. Objectives: The primary aim of this study was to determine the relationship between cutaneous sebum levels and acneiform rash, a typical skin toxicity of EGFR inhibitors, by measuring the sebum levels before and after EGFR inhibitor treatment. Methods: Eight patients diagnosed with non–small cell lung cancer (NSCLC (three men and five women with an average age of 69.3 years who were initiated on treatment with EGFR inhibitors (either gefitinib [Iressa®] or erlotinib [Tarceva®] were enrolled. Using a Sebumeter®, sebum levels in the face, chest, and back of each patient were measured before and after EGFR inhibitor treatment. The development of acneiform rash in each skin region was also assessed. Results: Changes in sebum level along with the development of an acneiform rash were observed after patients were started on EGFR inhibitor treatment. Patients who developed an EGFR inhibitor–induced acneiform rash tended to have higher pretreatment sebum levels (baseline than did patients who did not experience an acneiform rash. At each time point measurement, sebum levels were found to be significantly higher in patients who had developed an acneiform rash at that time. Patients who developed rash during treatment showed greater differences in sebum level compared with

  6. EGFR tyrosine kinase inhibitors versus cranial radiation therapy for EGFR mutant non-small cell lung cancer with brain metastases: A systematic review and meta-analysis

    Background and purpose: EGFR TKIs alone have demonstrated activity against intracranial disease in EGFR mutant non-small cell lung cancer (NSCLC). This study aimed to determine if upfront cranial radiotherapy improves intracranial disease control and survival outcomes in EGFR mutant NSCLC with brain metastases relative to TKIs alone. Materials and methods: We searched MEDLINE and various conference proceedings from 2008 to July 2014 for eligible studies where patients received upfront cranial radiotherapy or TKIs alone. Outcomes of interest were overall intracranial disease response rate (ORR), four-month intracranial disease progression-free survival (PFS), two-year overall survival (OS) and neurological adverse events (AE). We used random effects models to pool outcomes across studies and compared them using interaction tests. Results: We found 12 non-comparative observational studies (n = 363) with severe methodological limitations. Upfront cranial radiotherapy results in similar intracranial disease ORR (relative risk (RR) 0.93, 95% confidence interval (CI) 0.82–1.06; interaction p value (p) = 0.53), improved four-month intracranial disease PFS (RR 1.06, 95% CI 1.00–1.12; p = 0.03), improved two-year OS (RR 1.33, 95% CI 1.00–1.77; p = 0.05) but caused more neurological AEs than TKIs alone. Conclusion: There is evidence, albeit of low quality, that upfront cranial radiotherapy may improve intracranial disease control and survival outcomes compared with TKI alone

  7. Activity determination of 59Fe

    Iron-59 was measured in three commercial and two custom-built liquid scintillation counters. The counting efficiencies were determined using CIEMAT/NIST efficiency tracing and the triple-to-double coincidence ratio (TDCR) method, respectively. The efficiency computation for the TDCR method was realized by means of the MICELLE2 program, applying a stochastic model for the computation of electron emission spectra. The program was extended to make calculations of spectra originating from complex decay schemes possible. In addition, a new parameterization of electron stopping powers for 10 commercial liquid scintillation cocktails was included in the software. The activities determined with the two methods were in very good agreement; the relative standard uncertainty of the combined result was found to be 0.16%. It was used to calibrate a 4π ionization chamber at PTB for future calibrations of this isotope which is used for investigations of iron metabolism. A standardized solution was submitted to the Bureau International des Poids et Mesures (BIPM) to be measured in the ionization chambers of the International Reference System (SIR) for comparison purposes. The liquid scintillation samples were also measured in a new portable TDCR system with three channel photomultipliers. Although this system has a much lower counting efficiency, the activity was in satisfactory agreement with the conventional TDCR system. The usage of the portable TDCR system, thus, provides an important test of the free parameter model. - Highlights: • Iron-59 was measured by means of liquid scintillation counters. • CIEMAT/NIST efficiency tracing and the TDCR method were applied. • The models were extended for complex decay schemes. • The relative standard uncertainty was found to be 0.16%

  8. Prolyl isomerase Pin1 promotes survival in EGFR-mutant lung adenocarcinoma cells with an epithelial-mesenchymal transition phenotype.

    Sakuma, Yuji; Nishikiori, Hirotaka; Hirai, Sachie; Yamaguchi, Miki; Yamada, Gen; Watanabe, Atsushi; Hasegawa, Tadashi; Kojima, Takashi; Niki, Toshiro; Takahashi, Hiroki

    2016-04-01

    The secondary epidermal growth factor receptor (EGFR) T790M mutation is the most prominent mechanism that confers resistance to first- or second-generation EGFR tyrosine kinase inhibitors (TKIs) in lung cancer treatment. Although third-generation EGFR TKIs can suppress the kinase activity of T790M-positive EGFR, they still cannot eradicate EGFR-mutated cancer cells. We previously reported that a subpopulation of EGFR-mutant lung adenocarcinomas depends on enhanced autophagy, instead of EGFR, for survival, and in this study we explore another mechanism that contributes to TKI resistance. We demonstrate here that an EGFR-mutant lung adenocarcinoma cell line, H1975 (L858R+T790M), has a subset of cells that exhibits an epithelial-mesenchymal transition (EMT) phenotype and can thrive in the presence of third-generation EGFR TKIs. These cells depend on not only autophagy but also on the isomerase Pin1 for survival in vitro, unlike their parental cells. The Pin1 protein was expressed in an EGFR-mutant lung cancer tissue that has undergone partial EMT and acquired resistance to EGFR TKIs, but not its primary tumor. These findings suggest that inhibition of Pin1 activity can be a novel strategy in lung cancer treatment. PMID:26752745

  9. Effect of the BRCA1-SIRT1-EGFR axis on cisplatin sensitivity in ovarian cancer

    Li, Da; Wu, Qi-Jun; Bi, Fang-Fang; Chen, Si-Lei; Zhou, Yi-Ming; Zhao, Yue; Yang, Qing

    2016-01-01

    There is accumulating evidence that breast cancer 1 (BRCA1), sirtuin 1 (SIRT1), and epidermal growth factor receptor (EGFR) help to modulate cisplatin cytotoxicity. The role of dynamic crosstalk among BRCA1, SIRT1, and EGFR in cisplatin sensitivity remains largely unknown. We found that BRCA1, SIRT1, and EGFR levels were increased in cisplatin-resistant ovarian cancers compared with those in cisplatin-sensitive ovarian cancers. Hypomethylation in the BRCA1 promoter was associated with BRCA1 activation, significantly elevated SIRT1 levels, decreased nicotinamide adenine dinucleotide (NAD)-mediated SIRT1 activity, and decreased EGFR levels. Treatment with 5 and 10 μg/ml cisplatin induced a gradual increase in BRCA1 and SIRT1 levels and a gradual decrease in NAD levels and NAD-mediated SIRT1 activity, whereas EGFR levels were increased or decreased by treatment with 5 or 10 μg/ml cisplatin, respectively. The overexpression of SIRT1 or the enhancement of SIRT1 activity synergistically enhanced the BRCA1-mediated effects on EGFR transcription. In contrast, the knockdown of SIRT1 or the inhibition of SIRT1 activity inhibited the BRCA1-mediated effects on EGFR transcription. BRCA1 regulates EGFR through a BRCA1-mediated balance between SIRT1 expression and activity. Those results improve our understanding of the basic molecular mechanism underlying BRCA1-related cisplatin resistance in ovarian cancer.

  10. An in vivo C. elegans model system for screening EGFR-inhibiting anti-cancer drugs.

    Young-Ki Bae

    Full Text Available The epidermal growth factor receptor (EGFR is a well-established target for cancer treatment. EGFR tyrosine kinase (TK inhibitors, such as gefinitib and erlotinib, have been developed as anti-cancer drugs. Although non-small cell lung carcinoma with an activating EGFR mutation, L858R, responds well to gefinitib and erlotinib, tumors with a doubly mutated EGFR, T790M-L858R, acquire resistance to these drugs. The C. elegans EGFR homolog LET-23 and its downstream signaling pathway have been studied extensively to provide insight into regulatory mechanisms conserved from C. elegans to humans. To develop an in vivo screening system for potential cancer drugs targeting specific EGFR mutants, we expressed three LET-23 chimeras in which the TK domain was replaced with either the human wild-type TK domain (LET-23::hEGFR-TK, a TK domain with the L858R mutation (LET-23::hEGFR-TK[L858R], or a TK domain with the T790M-L858R mutations (LET-23::hEGFR-TK[T790M-L858R] in C. elegans vulval cells using the let-23 promoter. The wild-type hEGFR-TK chimeric protein rescued the let-23 mutant phenotype, and the activating mutant hEGFR-TK chimeras induced a multivulva (Muv phenotype in a wild-type C. elegans background. The anti-cancer drugs gefitinib and erlotinib suppressed the Muv phenotype in LET-23::hEGFR-TK[L858R]-expressing transgenic animals, but not in LET-23::hEGFR-TK[T790M-L858R] transgenic animals. As a pilot screen, 8,960 small chemicals were tested for Muv suppression, and AG1478 (an EGFR-TK inhibitor and U0126 (a MEK inhibitor were identified as potential inhibitors of EGFR-mediated biological function. In conclusion, transgenic C. elegans expressing chimeric LET-23::hEGFR-TK proteins are a model system that can be used in mutation-specific screens for new anti-cancer drugs.

  11. EGFR overexpressing cells and tumors are dependent on autophagy for growth and survival

    Background and purpose: The epidermal growth factor receptor (EGFR) is overexpressed, amplified or mutated in various human epithelial tumors, and is associated with tumor aggressiveness and therapy resistance. Autophagy activation provides a survival advantage for cells in the tumor microenvironment. In the current study, we assessed the potential of autophagy inhibition (using chloroquine (CQ)) in treatment of EGFR expressing tumors. Material and methods: Quantitative PCR, immunohistochemistry, clonogenic survival, proliferation assays and in vivo tumor growth were used to assess this potential. Results: We show that EGFR overexpressing xenografts are sensitive to CQ treatment and are sensitized to irradiation by autophagy inhibition. In HNSSC xenografts, a correlation between EGFR and expression of the autophagy marker LC3b is observed, suggesting a role for autophagy in EGFR expressing tumors. This observation was substantiated in cell lines, showing high EGFR expressing cells to be more sensitive to CQ addition as reflected by decreased proliferation and survival. Surprisingly high EGFR expressing cells display a lower autophagic flux. Conclusions: The EGFR high expressing cells and tumors investigated in this study are highly dependent on autophagy for growth and survival. Inhibition of autophagy may therefore provide a novel treatment opportunity for EGFR overexpressing tumors

  12. Combination of afatinib with cetuximab in patients with EGFR-mutant non-small-cell lung cancer resistant to EGFR inhibitors.

    Ribeiro Gomes, Jéssica; Cruz, Marcelo Rocha S

    2015-01-01

    Tyrosine kinase inhibitors (TKIs) targeting the epidermal growth factor receptor (EGFR) have shown effectiveness for advanced non-small-cell lung cancer (NSCLC) with activating mutations in the EGFR gene. However, resistance to the EGFR TKIs develops mostly secondary to T790M mutation in exon 20. The use of afatinib associated with cetuximab represents a new possibility of therapy following progression on gefitinib or erlotinib. We present two patients who acquired resistance to first-generation TKI and who underwent combination treatment with afatinib plus cetuximab as third-line therapy. Both patients presented partial response, and the time duration of disease control was 8 months and 10 months. The combined use of afatinib plus cetuximab emerges as a new possibility for the treatment of patients with advanced NSCLC harboring mutated EGFR after progression on first-generation EGFR TKIs with consequently acquired resistance to TKIs. Further studies are necessary to consolidate the data. PMID:26056478

  13. EGFR: The Paradigm of an Oncogene-Driven Lung Cancer.

    Riely, Gregory J; Yu, Helena A

    2015-05-15

    Somatic, activating mutations in EGFR identify a significant minority of patients with non-small cell lung cancer (NSCLC). Although these mutations are associated with an approximately 70% response rate to some EGFR tyrosine kinase inhibitors (gefitinib, erlotinib, and afatinib), patients develop resistance (i.e., "acquired resistance") after a median of 9 to 12 months. In patients with clinical acquired resistance, repeat biopsy of tumors has identified a number of relevant mechanisms of resistance, but by far the most frequent event is the acquisition of EGFR T790M, a mutation in the "gatekeeper" residue that confers resistance to gefitinib, erlotinib, and afatinib. This emphasizes the critical dependence upon EGFR signaling for some tumors, a property that has been exploited therapeutically. Dual EGFR blockade using afatinib and cetuximab led to a 29% radiographic response rate. More recently, drugs that target EGFR T790M (e.g., rociletinib, AZD9291, and others) have entered clinical trials, with impressive results observed in phase I clinical trials. The development of these newer drugs, with efficacy after resistance to first-line EGFR tyrosine kinase inhibitor, has led to exploration of these strategies in multiple disease settings: at resistance, in the first line, and in adjuvant treatment of those with completely resected early-stage disease who would otherwise die of recurrent/metastatic disease. This example of translational research that identifies mechanisms of resistance to first-generation drugs, and then targets those mechanisms yielding clinical benefit, is a paradigm for how targeted therapies can be developed. PMID:25979928

  14. Novel carbon-11 labeled 4-dimethylamino-but-2-enoic acid [4-(phenylamino)-quinazoline-6-yl]-amides: potential PET bioprobes for molecular imaging of EGFR-positive tumors

    We have previously reported of labeled reversible and irreversible EGFR inhibitors, such as 4-(3,4-dichloro-6-fluoroanilino)-6,7-dimethoxyquinazoline (ML01) and 6-acrylamido-4-(3,4-dichloro-6-fluoroanilino)quinazoline (ML03), to be suboptimal as imaging agents. On the basis of these studies, a new generation of novel, more chemically stable irreversible inhibitors was labeled with carbon-11 as potential positron emission tomography (PET) biomarkers for molecular imaging of epidermal growth factor receptor (EGFR)-positive tumors. In these new labeled, irreversible inhibitors the acryl-amide group at the 6-position of the quinazoline ring was replaced with a 4-dimethylamino-but-2-enoic amide. The nonlabeled compounds were evaluated in vitro to determine their EGFR autophosphorylation IC50 values. The IC50 values indicated that these new irreversible compounds possess similar potencies towards the EGFR, as the parent compound, ML03. These compounds were labeled with carbon-11 at the dimethylamine moiety, using the well known labeling reagent C-11 MeI. The labeling procedure was automated using a commercial module. The final products were obtained with 10% decay corrected radiochemical yield, 99% radiochemical purity, 96% chemical purity, and a high specific activity of 2.7 Ci/μmol EOB. The high potency of these new labeled bioprobes towards the EGFR establishes their potential to serve as PET agents for molecular imaging of EGFR-positive tumors

  15. Radiation Response Modulation of GW572016 (EGFR/HER2 Dual Tyrosine Kinase Inhibitor) in Human Breast Cancer Xenografts

    Kim, Yeon Sil; Roh, Kwang Won; Chae, Soo Min; Yoon, Sei Chul; Jang, Hong Seok; Chung, Su Mi [The Catholic University of Korea, College of Medicine, Seoul (Korea, Republic of); Mun, Seong Kwon [Eulji University Hospital, Daejeon (Korea, Republic of)

    2007-12-15

    Purpose: We examined the effect of the dual EGFR/HER2 tyrosine kinase inhibitor, GW572016, on EGFR/HER2 receptor phosphorylation, inhibition of downstream signaling and radiosensitization in either an EGFR or HER2 overexpressing human breast cancer xenograft. Materials and Methods: We established SCID mice xenografts from 4 human breast cancer cell line that overexpressed EGFR or HER 2 (SUM 102, SUM 149, SUM 185, SUM 225). Two series of xenografts were established. One series was established for determining inhibition of the EGFR/HER2 receptor and downstream signaling activities by GW572016. The other series was established for determining the radiosensitization effect of GW572016. Inhibition of the receptor and downstream signaling proteins were measured by the use of immunoprecipitation and Western blotting. For determining the in vivo radiosensitization effect of GW572016, we compared tumor growth delay curves in the following four treatment arms: a) control; b) GW572016 alone; c) radiotherapy (RT) alone; d) GW572016 and RT. Results: GW572016 inhibited EGFR, HER2 receptor phosphorylation in SUM 149 and SUM 185 xenografts. In addition, the p44/42 MAPK (ERK 1/2) downstream signaling pathway was inactivated by GW572016 in the SUM 185 xenograft. In the SUM 225 xenograft, we could not observe inhibition of HER2 receptor phosphorylation by GW572016; both p44/42 MAPK (Erk1/2) and Akt downstream signal protein phosphorylation were inhibited by GW572016. GW572016 inhibited growth of the tumor xenograft of SUM 149 and SUM 185. The combination of GW572016 and RT enhanced growth inhibition greater than that with GW572016 alone or with RT alone in the SUM 149 xenograft. GW572016 appears to act as an in vivo radiosensitizer. Conclusion: GW572016 inhibited EGFR/HER2 receptor phosphorylation and downstream signaling pathway proteins. GW572016 modestly inhibited the growth of tumor in the SUM 185 xenograft and showed radiosensitization in the SUM 149 xenograft. Our results

  16. Effect of EGFR-TKI retreatment following chemotherapy for advanced non-small cell lung cancer patients who underwent EGFR-TKI

    Non-small cell lung cancer (NSCLC) patients with epidermal growth factor receptor (EGFR)-activating mutations have higher response rate and more prolonged survival following treatment with single-agent EGFR tyrosine kinase inhibitor (EGFR-TKI) compared with patients with wild-type EGFR. However, all patients treated with reversible inhibitors develop acquired resistance over time. The mechanisms of resistance are complicated. The lack of established therapeutic options for patients after a failed EGFR-TKI treatment poses a great challenge to physicians in managing this group of lung cancer patients. This study evaluates the influence of EGFR-TKI retreatment following chemotherapy after failure of initial EGFR-TKI within at least 6 months on NSCLC patients. The data of 27 patients who experienced treatment failure from their initial use of EGFR-TKI within at least 6 months were analyzed. After chemotherapy, the patients were retreated with EGFR-TKI (gefitinib 250 mg qd or erlotinib 150 mg qd), and the tumor progression was observed. The patients were assessed for adverse events and response to therapy. Targeted tumor lesions were assessed with CT scan. Of the 27 patients who received EGFR-TKI retreatment, 1 (3.7%) patient was observed in complete response (CR), 8 (29.6%) patients in partial response (PR), 14 (51.9%) patients in stable disease (SD), and 4 (14.8%) patients in progressive disease (PD). The disease control rate (DCR) was 85.2% (95% CI: 62%-94%). The median progression-free survival (mPFS) was 6 months (95% CI: 1-29). Of the 13 patients who received the same EGFR-TKI, 1 patient in CR, 3 patients in PR, 8 patients in SD, and 2 patients in PD were observed. The DCR was 84.6%, and the mPFS was 5 months. Of the 14 patients who received another EGFR-TKI, no patient in CR, 6 patients in PR, 6 patients in SD, and 2 patients in PD were observed. The DCR was 85.7%, and the mPFS was 9.5 months. Significant difference was found between the two groups in PFS but not

  17. EGFR Inhibition Blocks Palmitic Acid-induced inflammation in cardiomyocytes and Prevents Hyperlipidemia-induced Cardiac Injury in Mice.

    Li, Weixin; Fang, Qilu; Zhong, Peng; Chen, Lingfeng; Wang, Lintao; Zhang, Yali; Wang, Jun; Li, Xiaokun; Wang, Yi; Wang, Jingying; Liang, Guang

    2016-01-01

    Obesity is often associated with increased risk of cardiovascular diseases. Previous studies suggest that epidermal growth factor receptor (EGFR) antagonism may be effective for the treatment of angiotensin II-induced cardiac hypertrophy and diabetic cardiomyopathy. This study was performed to demonstrate if EGFR plays a role in the pathogenesis of hyperlipidemia/obesity-related cardiac injuries. The in vivo studies using both wild type (WT) and apolipoprotein E (ApoE) knockout mice fed with high fat diet (HFD) showed the beneficial effects of small-molecule EGFR inhibitors, AG1478 and 542, against obesity-induced myocardial injury. Administration of AG1478 and 542 significantly reduced myocardial inflammation, fibrosis, apoptosis, and dysfunction in both two obese mouse models. In vitro, EGFR signaling was blocked by either siRNA silencing or small-molecule EGFR inhibitors in palmitic acid (PA)-stimulated cardiomyocytes. EGFR inhibition attenuated PA-induced inflammatory response and apoptosis in H9C2 cells. Furthermore, we found that PA-induced EGFR activation was mediated by the upstream TLR4 and c-Src. This study has confirmed the detrimental effect of EGFR activation in the pathogenesis of obesity-induced cardiac inflammatory injuries in experimental mice, and has demonstrated the TLR4/c-Src-mediated mechanisms for PA-induced EGFR activation. Our data suggest that EGFR may be a therapeutic target for obesity-related cardiovascular diseases. PMID:27087279

  18. EGFR Interacts with the Fusion Protein of Respiratory Syncytial Virus Strain 2-20 and Mediates Infection and Mucin Expression

    Stobart, Christopher C.; Hotard, Anne L.; Villenave, Remi; Meng, Jia; Pretto, Carla D.; Shields, Michael D.; Nguyen, Minh Trang; Todd, Sean O.; Chi, Michael H.; Hammonds, Jason; Krumm, Stefanie A.; Spearman, Paul; Plemper, Richard K.; Sakamoto, Kaori; Peebles, R. Stokes; Power, Ultan F.; Moore, Martin L.

    2016-01-01

    Respiratory syncytial virus (RSV) is the major cause of viral lower respiratory tract illness in children. In contrast to the RSV prototypic strain A2, clinical isolate RSV 2–20 induces airway mucin expression in mice, a clinically relevant phenotype dependent on the fusion (F) protein of the RSV strain. Epidermal growth factor receptor (EGFR) plays a role in airway mucin expression in other systems; therefore, we hypothesized that the RSV 2–20 F protein stimulates EGFR signaling. Infection of cells with chimeric strains RSV A2-2-20F and A2-2-20GF or over-expression of 2–20 F protein resulted in greater phosphorylation of EGFR than infection with RSV A2 or over-expression of A2 F, respectively. Chemical inhibition of EGFR signaling or knockdown of EGFR resulted in diminished infectivity of RSV A2-2-20F but not RSV A2. Over-expression of EGFR enhanced the fusion activity of 2–20 F protein in trans. EGFR co-immunoprecipitated most efficiently with RSV F proteins derived from “mucogenic” strains. RSV 2–20 F and EGFR co-localized in H292 cells, and A2-2-20GF-induced MUC5AC expression was ablated by EGFR inhibitors in these cells. Treatment of BALB/c mice with the EGFR inhibitor erlotinib significantly reduced the amount of RSV A2-2-20F-induced airway mucin expression. Our results demonstrate that RSV F interacts with EGFR in a strain-specific manner, EGFR is a co-factor for infection, and EGFR plays a role in RSV-induced mucin expression, suggesting EGFR is a potential target for RSV disease. PMID:27152417

  19. Synthesis of p-O-Alkyl Salicylanilide Derivatives as Novel EGFR Inhibitors.

    Zhang, Li; Hou, Lin; Sun, Wenyan; Yu, Zidong; Wang, Jibo; Gao, Hua; Yang, Guiming

    2016-02-01

    Preclinical Research Epidermal growth factor receptor (EGFR), a validated target for anticancer drugs, plays a critical role in tumorigenesis and tumor development. A series of p-O-alkyl salicylanilide derivatives were designed and synthesized as novel EGFR inhibitors using a salicylic acid scaffold. A simulated six-membered ring strategy formed through intramolecular hydrogen bonds was employed to mimic the planar quinazoline of the EGFR antagonist, gefitinib. The derived compounds with hydroxyl at the ortho position were more potent than ones with methoxyl group. In particular, compounds 5d and 5b displayed significant EGFR inhibitory (IC50 values = 0.30 and 0.45 μM, respectively) activity as well as potent antiproliferative activity in A431 and HCT-116 tumor cells. These salicylanilides could be considered as promising lead compounds for developing novel EGFR inhibitors. PMID:26763193

  20. AZD9291 in EGFR-mutant advanced non-small-cell lung cancer patients.

    Remon, Jordi; Planchard, David

    2015-11-01

    Non-small-cell lung cancer (NSCLC) patients whose tumors have an EGFR-activating mutation develop acquired resistance after a median of 9-11 months from the beginning of treatment with erlotinib, gefitinib and afatinib. T790M mutation is the cause of this resistance in approximately 60% of cases. AZD9291 is an oral, irreversible, mutant-selective EGF receptor (EGFR) tyrosine kinase inhibitor (TKI) developed to have potency against EGFR mutations, including T790M mutation, while sparing wild-type EGFR. A Phase I trial of AZD9291 in EGFR-mutant NSCLC patients, demonstrated high activity, essentially among T790M-mutant tumors, with a manageable tolerability profile. Ongoing Phase III trials are evaluating AZD9291 in EGFR-mutant patients as first-line treatment compared with erlotinib and gefitinib; and as second-line treatment compared with chemotherapy after progression on EGFR TKI in T790M-mutant tumors. Better identification of T790M-mutant tumors post EGFR TKI relapse and mechanisms of resistance to AZD9291 are the future challenges. This article reviews the emerging data regarding AZD9291 in the treatment of patients with advanced NSCLC. PMID:26450446

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

    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.

  2. 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

    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. 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. 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 < 2.6 respectively (p = 0.002) and in 10 (36%) and 1 (6%) cases with a CISH EGFR GCN ≥ 2.12 and < 2.12 respectively (p = 0.03). Median TTP was 7.7 and 6.4 months in patients showing increased FISH and CISH EGFR GCN whereas it was 2.9 and 3.1 months in those with low FISH and CISH EGFR GCN (p = 0.04 and 0.02 respectively). 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

  3. Lung Adenocarcinoma with Pulmonary Miliary Metastases and Complex Somatic Heterozygous EGFR Mutation

    Alexandre Schaller

    2014-11-01

    Full Text Available The pretreatment detection of an activating mutation of EGFR is now routinely performed in metastatic nonsquamous non-small cell lung cancer (NSCLC. The therapeutic impact of such a detection is major, as patients with advanced NSCLC exhibiting a mutation of exon 19 or 21 will benefit from EGFR-tyrosine kinase inhibitors (TKI. The presence of an EGFR resistance mutation, such as T790M in EGFR-TKI-naïve patients, is seldom looked for and is related either to a germinal mutation or to somatically mutated subclones. It has a negative predictive impact. We present the case of a patient with a lung papillary adenocarcinoma and miliary intrapulmonary metastases whose tumor displays a somatic complex heterozygous EGFR mutation, combining L858R (exon 21 and a primary resistance mutation T790M (exon 20, both detected by direct sequencing.

  4. EGFR Transactivation by Peptide G Protein-Coupled Receptors in Cancer.

    Moody, Terry W; Nuche-Berenguer, Bernardo; Nakamura, Taichi; Jensen, Robert T

    2016-01-01

    Lung cancer kills approximately 1.3 million citizens in the world annually. The tyrosine kinase inhibitors (TKI) erlotinib and gefitinib are effective anti-tumor agents especially in lung cancer patients with epidermal growth factor receptor (EGFR) mutations. The goal is to increase the potency of TKI in lung cancer patients with wild type EGFR. G protein-coupled receptors (GPCR) transactivate the wild type EGFR in lung cancer cells. The GPCR can be activated by peptide agonists causing phosphatidylinositol turnover or stimulation of adenylylcyclase. Recently, nonpeptide antagonists were found to inhibit the EGFR transactivation caused by peptides. Nonpeptide antagonists for bombesin (BB), neurotensin (NTS) and cholecystokinin (CCK) inhibit lung cancer growth and increase the cytotoxicity of gefitinib. The results suggest that GPCR transactivation of the EGFR may play an important role in cancer cell proliferation. PMID:25563590

  5. EGFR cooperates with glucose transporter SGLT1 to enable chromatin remodeling in response to ionizing radiation

    Background and purpose: EGFR and the sodium-dependent glucose transporter, SGLT1, are found in complex after radiation treatment. The aim of this study was to elucidate the role of EGFR in glucose uptake and chromatin remodeling. Material and methods: Glucose accumulation was quantified with help of 3H-glucose. Involvement of SGLT was detected by a specific inhibitor. Role of EGFR was proved by EGFR overexpression and siRNA driven knockdown. Functional endpoints were intracellular ATP levels, protein expression, residual DNA-damage and colony formation. Results: EGFR/SGLT1 interactions in response to ionizing radiation were associated with increased glucose uptake. Nevertheless, tumor cells exhibit ATP depletion following irradiation. Recovery from radiation-induced ATP crisis was EGFR/SGLT-dependent and associated with increased cell survival and improved DNA-repair. The blockage of either EGFR or SGLT inhibited ATP level recovery and histone H3 modifications crucial for both chromatin remodeling and DNA repair in response to irradiation. Inhibition of the acetyltransferase TIP60, which is essential for histone H3-K9 acetylation and ATM activation, prevented energy crisis and chromatin remodeling. Conclusions: Radiation-associated interactions between SGLT1 and EGFR resulted in increased glucose uptake, which counteracts the ATP crisis in tumor cells due to chromatin remodeling. The blockage of recovery from ATP crisis led to radio-sensitization in tumor cells

  6. Routine implementation of EGFR mutation testing in clinical practice in Flanders: 'HERMES' project.

    Janssens, A; De Droogh, E; Lefebure, A; Kockx, M; Pauwels, P; Germonpre, P; van Meerbeeck, J P

    2014-04-01

    Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) is the recommended first-line treatment in metastatic EGFR-mutation-positive non-small cell lung cancer (NSCLC) patients. Such a personalized treatment requires fast EGFR mutation testing. This study was performed to determine the turn around time (TAT) for EGFR mutation testing on tumour samples of NSCLC in the clinical care in the region of Antwerp (Belgium). The secondary aim was to determine the frequency of EGFR mutations in this Flemish population. Tumour tissue was prospectively obtained from lung cancer patients in participating hospitals and sent from the local pathology laboratory (lab) to two central laboratories (labs) where EGFR-mutation analysis was performed. Results were returned from the central labs to the clinicians and the local pathology lab. TAT was defined as the interval between the request from the oncologist and the result obtained by the oncologist. One hundred and seven specimens were analysed. The clinician got the result from the local lab in a median time of 10 days (3-37 days) and from the central lab in 9 days (3-29 days). We detected seven mutations (7%) in this study population, all occurring in tumours with an adenocarcinoma histology, four (57%) in men and five (71%) in (ex-)smokers. There were six exon 19 deletions and one L858R mutation. It is possible to implement EGFR-mutation testing with timely reporting of the EGFR-mutation status. EGFR-mutation occurs in 7% of Flemish patients with NSCLC. Patients with advanced non-squamous NSCLC should be tested for EGFR mutation regardless of their gender and smoking history. PMID:24724747

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

    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

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

    Sanders, Jeffrey M; Wampole, Matthew E; Thakur, Mathew L; Wickstrom, Eric

    2013-01-01

    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 therapeutics targeting EGF

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

    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.

  10. Missense Mutations in Exons 18–24 of EGFR in Hepatocellular Carcinoma Tissues

    Ravat Panvichian

    2015-01-01

    Full Text Available Epidermal growth factor receptor (EGFR, a transmembrane tyrosine kinase receptor, plays important roles in various cancers. In nonsmall cell lung cancer (NSCLC, EGFR mutations cluster around the ATP-binding pocket (exons 18–21 and some of these mutations activate the kinase and induce an increased sensitivity to EGFR-tyrosine kinase inhibitors. Nevertheless, data of EGFR mutations in HCC are limited. In this study, we investigated EGFR expression by immunohistochemistry and EGFR mutations (exons 18–24 by PCR cloning and sequencing. EGFR overexpression in HCC and matched nontumor tissues were detected in 13/40 (32.5% and 10/35 (28.6%, respectively. Moreover, missense and silent mutations were detected in 13/33 (39.4% and 11/33 (33.3% of HCC tissues, respectively. The thirteen different missense mutations were p.L730P, p.V742I, p.K757E, p.I780T, p.N808S, p.R831C, p.V851A, p.V897A, p.S912P, p.P937L, p.T940A, p.M947V, and p.M947T. We also found already known SNP, p.Q787Q (CAG>CAA, in 13/33 (39.4% of HCC tissues. However, no significant association was detected between EGFR mutations and EGFR overexpression, tissue, age, sex, tumor size, AFP, HBsAg, TP53, and Ki-67. Further investigation is warranted to validate the frequency and activity of these missense mutations, as well as their roles in HCC tumorigenesis and in EGFR-targeted therapy.

  11. 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

    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.

  12. Src inhibitors act through different mechanisms in Non-Small Cell Lung Cancer models depending on EGFR and RAS mutational status

    Formisano, Luigi; D'Amato, Valentina; Servetto, Alberto; Brillante, Simona; Raimondo, Lucia; Di Mauro, Concetta; Marciano, Roberta; Orsini, Roberta Clara; Cosconati, Sandro; Randazzo, Antonio; Parsons, Sarah J.; Montuori, Nunzia; Veneziani, Bianca Maria; De Placido, Sabino

    2015-01-01

    Resistance to the EGFR tyrosine kinase inhibitors (TKIs) gefitinib and erlotinib, often related to Ras or secondary EGFR mutations, is a relevant clinical issue in Non-Small Cell Lung Cancer (NSCLC). Although Src TK has been involved in such resistance, clinical development of its inhibitors has been so far limited. To better define the molecular targets of the Src TKIs saracatinib, dasatinib and bosutinib, we used a variety of in vitro/in vivo studies. Kinase assays supported by docking analysis demonstrated that all the compounds directly inhibit EGFR TK variants. However, in live cells only saracatinib efficiently reduced EGFR activation, while dasatinib was the most effective agent in inhibiting Src TK. Consistently, a pronounced anti-proliferative effect was achieved with saracatinib, in EGFR mutant cells, or with dasatinib, in wt EGFR/Ras mutant cells, poorly dependent on EGFR and erlotinib-resistant. We then identified the most effective drug combinations to overcome resistance to EGFR inhibitors, both in vitro and in nude mice: in T790M EGFR erlotinib-resistant cells, saracatinib with the anti-EGFR mAb cetuximab; in Ras mutant erlotinib-resistant models, dasatinib with the MEK inhibitor selumetinib. Src inhibitors may act with different mechanisms in NSCLCs, depending on EGFR/Ras mutational profile, and may be integrated with EGFR or MEK inhibitors for different cohorts of NSCLCs. PMID:26325669

  13. A case of EGFR mutant lung adenocarcinoma that acquired resistance to EGFR-tyrosine kinase inhibitors with MET amplification and epithelial-to-mesenchymal transition

    Miyoshi S

    2015-04-01

    Full Text Available Seigo Miyoshi,1 Takahide Kato,1 Hitoshi Katayama,1 Ryoji Ito,1 Yosuke Mizuno,2 Takafumi Okura,1 Jitsuo Higaki1 1Department of Cardiology, Pulmonology, Hypertension and Nephrology, Ehime University Graduate School of Medicine, Ehime, Japan; 2Department of Molecular Pathology, Ehime University Graduate School of Medicine, Ehime, Japan Abstract: EGFR mutant lung cancer responds to EGFR tyrosine kinase inhibitors (TKIs, but all patients eventually develop resistance to EGFR-TKIs. Herein we report a case of EGFR mutant lung adenocarcinoma that acquired resistance to EGFR-TKI with MET amplification and epithelial-to-mesenchymal transition (EMT. A 73-year-old woman was diagnosed with adenocarcinoma harboring an EGFR exon 19 deletion. She received gefitinib as second-line therapy. Tumors were reduced 1 month after gefitinib therapy. However, only a few months later, chest computed tomography results indicated cancer progression. Gefitinib therapy was stopped and docetaxel therapy started. However, she died 13 days after admission. Microscopic examination of postmortem specimens revealed a diffuse proliferation of atypical giant cells in primary and metastatic lesions, but no adenocarcinomatous components as in the antemortem specimens. Immunohistochemical analyses showed that antemortem tumor specimens were positive for CDH1 but negative for VIM. In contrast, postmortem tumor specimens were positive for VIM but negative for CDH1. Genetic analyses revealed MET amplification. We concluded that resistance to EGFR-TKI might be caused by MET amplification and EMT. To our knowledge, no clinical studies have reported that MET amplification and EMT together may be associated with acquired resistance to EGFR-TKI. Second biopsy after the development of EGFR-TKI resistance may be recommended to determine the best therapeutic strategy. Keywords: epidermal growth factor receptor tyrosine kinase inhibitor, MET amplification, epithelial-to-mesenchymal transition

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

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

    Wang, Shuhang; Cang, Shundong; Liu, Delong

    2016-01-01

    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. PMID:27071706

  16. NOX4 mediates cytoprotective autophagy induced by the EGFR inhibitor erlotinib in head and neck cancer cells

    Sobhakumari, Arya [Interdisciplinary Graduate Program in Human Toxicology, The University of Iowa, Iowa City, IA (United States); Department of Pathology, The University of Iowa, Iowa City, IA (United States); Schickling, Brandon M. [Department of Internal Medicine, The University of Iowa, Iowa City, IA (United States); Love-Homan, Laurie; Raeburn, Ayanna [Department of Pathology, The University of Iowa, Iowa City, IA (United States); Fletcher, Elise V.M. [Interdisciplinary Graduate Program in Human Toxicology, The University of Iowa, Iowa City, IA (United States); Department of Pathology, The University of Iowa, Iowa City, IA (United States); Case, Adam J. [Free Radical and Radiation Biology Program, Department of Radiation Oncology, The University of Iowa, Iowa City, IA (United States); Domann, Frederick E. [Interdisciplinary Graduate Program in Human Toxicology, The University of Iowa, Iowa City, IA (United States); Department of Pathology, The University of Iowa, Iowa City, IA (United States); Free Radical and Radiation Biology Program, Department of Radiation Oncology, The University of Iowa, Iowa City, IA (United States); Holden Comprehensive Cancer Center, University of Iowa Hospitals and Clinics (UIHC), Iowa City, IA (United States); Miller, Francis J. [Department of Internal Medicine, The University of Iowa, Iowa City, IA (United States); Free Radical and Radiation Biology Program, Department of Radiation Oncology, The University of Iowa, Iowa City, IA (United States); Holden Comprehensive Cancer Center, University of Iowa Hospitals and Clinics (UIHC), Iowa City, IA (United States); and others

    2013-11-01

    Most head and neck squamous cell carcinomas (HNSCCs) overexpress epidermal growth factor receptor (EGFR) and EGFR inhibitors are routinely used in the treatment of HNSCC. However, many HNSCC tumors do not respond or become refractory to EGFR inhibitors. Autophagy, which is a stress-induced cellular self-degradation process, has been reported to reduce the efficacy of chemotherapy in various disease models. The purpose of this study is to determine if the efficacy of the EGFR inhibitor erlotinib is reduced by activation of autophagy via NOX4-mediated oxidative stress in HNSCC cells. Erlotinib induced the expression of the autophagy marker LC3B-II and autophagosome formation in FaDu and Cal-27 cells. Inhibition of autophagy by chloroquine and knockdown of autophagy pathway genes Beclin-1 and Atg5 sensitized both cell lines to erlotinib-induced cytotoxicity, suggesting that autophagy may serve as a protective mechanism. Treatment with catalase (CAT) and diphenylene iodonium (DPI) in the presence of erlotinib suppressed the increase in LC3B-II expression in FaDu and Cal-27 cells. Erlotinib increased NOX4 mRNA and protein expression by increasing its promoter activity and mRNA stability in FaDu cells. Knockdown of NOX4 using adenoviral siNOX4 partially suppressed erlotinib-induced LC3B-II expression, while overexpression of NOX4 increased expression of LC3B-II. These studies suggest that erlotinib may activate autophagy in HNSCC cells as a pro-survival mechanism, and NOX4 may play a role in mediating this effect. - Highlights: • Erlotinib increased LC3B-II and autophagosome formation in HNSCC cells. • Inhibition of autophagy sensitized HNSCC cells to erlotinib. • Erlotinib increased NOX4 promoter and 3′UTR luciferase activity. • Manipulating NOX4 decreases or increases autophagy.

  17. NOX4 mediates cytoprotective autophagy induced by the EGFR inhibitor erlotinib in head and neck cancer cells

    Most head and neck squamous cell carcinomas (HNSCCs) overexpress epidermal growth factor receptor (EGFR) and EGFR inhibitors are routinely used in the treatment of HNSCC. However, many HNSCC tumors do not respond or become refractory to EGFR inhibitors. Autophagy, which is a stress-induced cellular self-degradation process, has been reported to reduce the efficacy of chemotherapy in various disease models. The purpose of this study is to determine if the efficacy of the EGFR inhibitor erlotinib is reduced by activation of autophagy via NOX4-mediated oxidative stress in HNSCC cells. Erlotinib induced the expression of the autophagy marker LC3B-II and autophagosome formation in FaDu and Cal-27 cells. Inhibition of autophagy by chloroquine and knockdown of autophagy pathway genes Beclin-1 and Atg5 sensitized both cell lines to erlotinib-induced cytotoxicity, suggesting that autophagy may serve as a protective mechanism. Treatment with catalase (CAT) and diphenylene iodonium (DPI) in the presence of erlotinib suppressed the increase in LC3B-II expression in FaDu and Cal-27 cells. Erlotinib increased NOX4 mRNA and protein expression by increasing its promoter activity and mRNA stability in FaDu cells. Knockdown of NOX4 using adenoviral siNOX4 partially suppressed erlotinib-induced LC3B-II expression, while overexpression of NOX4 increased expression of LC3B-II. These studies suggest that erlotinib may activate autophagy in HNSCC cells as a pro-survival mechanism, and NOX4 may play a role in mediating this effect. - Highlights: • Erlotinib increased LC3B-II and autophagosome formation in HNSCC cells. • Inhibition of autophagy sensitized HNSCC cells to erlotinib. • Erlotinib increased NOX4 promoter and 3′UTR luciferase activity. • Manipulating NOX4 decreases or increases autophagy

  18. Concurrent hypermethylation of DNMT1, MGMT and EGFR genes in progression of gliomas

    Gömöri Éva

    2012-01-01

    Full Text Available Abstract Background Gliomas are the most common neoplasm of the brain. High-grade gliomas often resist treatment even with aggressive surgical resection and adjuvant radiation and chemotherapy. Despite the combined treatment, they frequently recur with the same or higher-grade histology. Genetic instability is commonly associated with inactivation of the normal DNA repair function and tumour suppressor genes as well as activation of oncogenes resulting from alterations of promoter hypermethylation, but the molecular mechanisms of the histological and clinical progression of gliomas are still poorly understood. Methods This study involved longitudinal analysis samples of primary and recurrent gliomas to determine whether the progression of low- and high-grade gliomas is associated with the promoter methylation of the DNMT1, MGMT and EGFR genes by PCR-based restriction enzyme assay. Epigenetic inactivation of these three important glioma-associated genes was analyzed in paired biopsy samples from 18 patients with tumour recurrence. Results The methylation analysis of the CpG sites in the DNA methyltransferase (DNMT1 promoter revealed a total of 6 hypermethylations (6/18, the methylguanine-DNA methyltransferase (MGMT promoter revealed a total of 10 hypermethylations (10/18 and the epithelial grow factor receptor (EGFR promoter revealed a total of 12 (12/18 hypermethylations respectively in recurrent gliomas. The results demonstrated that DNMT1 promoter hypermethylation does not occur in low-grade gliomas, it was mainly observed in secondary glioblastomas. Additionally, the MGMT and EGFR promoter was hypermethylated in both low-and high-grade GLs and their corresponding histological transformed GLs. Conclusion This study has provided further evidence that the histological transformation and progression of gliomas may be associated with the inactivation of the EGFR and MGMT genes. It seems that EGFR and MGMT promoter hypermethylations are early

  19. Targeting the EGFR/PCNA signaling suppresses tumor growth of triple-negative breast cancer cells with cell-penetrating PCNA peptides.

    Yung-Luen Yu

    Full Text Available Tyrosine 211 (Y211 phosphorylation of proliferation cell nuclear antigen (PCNA coincides with pronounced cancer cell proliferation and correlates with poor survival of breast cancer patients. In epidermal growth factor receptor (EGFR tyrosine kinase inhibitor (TKI-resistant cells, both nuclear EGFR (nEGFR expression and PCNA Y211 phosphorylation are increased. Moreover, the resistance to EGFR TKI is a major clinical problem in treating EGFR-overexpressing triple-negative breast cancer (TNBC. Thus, effective treatment to combat resistance is urgently needed. Here, we show that treatment of cell-penetrating PCNA peptide (CPPP inhibits growth and induces apoptosis of human TNBC cells. The Y211F CPPP specifically targets EGFR and competes directly for PCNA tyrosine Y211 phosphorylation and prevents nEGFR from binding PCNA in vivo; it also suppresses tumor growth by sensitizing EGFR TKI resistant cells, which have enhanced nEGFR function and abrogated classical EGFR membrane signaling. Furthermore, we identify an active motif of CPPP, RFLNFF (RF6 CPPP, which is necessary and sufficient to inhibit TKI-resistant TNBC cell growth of orthotopic implanted tumor in mice. Finally, the activity of its synthetic retro-inverted derivative, D-RF6 CPPP, on an equimolar basis, is more potent than RF6 CPPP. Our study reveals a drug candidate with translational potential for the future development of safe and effective therapeutic for EGFR TKI resistance in TNBC.

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

    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......-induced nephropathy (CIN) requirement when the definition s-creatinine ≥44μmol/l (0.5mg/dl) was used. CONCLUSIONS: eGFR in outpatients undergoing MRI or CT did vary independently of whether the patient received contrast or not. The findings probably reflect the natural variations in s-creatinine levels. This should...

  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.

    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. 5-Fluorocytosine combined with Fcy-hEGF fusion protein targets EGFR-expressing cancer cells

    Lan, Keng-Hsueh [Division of Radiation Oncology, Department of Oncology, National Taiwan University Hospital, Taipei 100, Taiwan (China); Shih, Yi-Sheng [Cancer Center, Taipei Veterans General Hospital, Taipei 112, Taiwan (China); Chang, Cheng Allen [Department of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, Taipei 112, Taiwan (China); School of Biomedical Science and Engineering, National Yang-Ming University, Taipei 112, Taiwan (China); Yen, Sang-Hue [Cancer Center, Taipei Veterans General Hospital, Taipei 112, Taiwan (China); Department of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, Taipei 112, Taiwan (China); Lan, Keng-Li, E-mail: kllan@vghtpe.gov.tw [Cancer Center, Taipei Veterans General Hospital, Taipei 112, Taiwan (China); Department of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, Taipei 112, Taiwan (China)

    2012-11-16

    Highlights: Black-Right-Pointing-Pointer EGFR-expressing epithelial cancers account for significant portion of cancer deaths. Black-Right-Pointing-Pointer EGF-EGFR signaling pathway is validated as an important anticancer drug target. Black-Right-Pointing-Pointer EGF and Fcy fusion protein (Fcy-hEGF) can bind to EGFR and convert 5-FC to 5-FU. Black-Right-Pointing-Pointer Fcy-hEGF combined with 5-FC preferentially inhibits EGFR-expressing cells viability. -- Abstract: Human epithelial cancers account for approximately 50% of all cancer deaths. This type of cancer is characterized by excessive activation and expression of the epidermal growth factor receptor (EGFR). The EGFR pathway is critical for cancer cell proliferation, survival, metastasis and angiogenesis. The EGF-EGFR signaling pathway has been validated as an important anticancer drug target. Increasing numbers of targeted therapies against this pathway have been either approved or are currently under development. Here, we adopted a prodrug system that uses 5-fluorocytosine (5-FC) and human EGF (hEGF) fused with yeast cytosine deaminase (Fcy) to target EGFR-overexpressing cancer cells and to convert 5-FC to a significantly more toxic chemotherapeutic, 5-fluorouracil (5-FU). We cloned and purified the Fcy-hEGF fusion protein from Pichia pastoris yeast. This fusion protein specifically binds to EGFR with a similar affinity as hEGF, approximately 10 nM. Fcy-hEGF binds tightly to A431 and MDA-MB-468 cells, which overexpress EGFR, but it binds with a lower affinity to MDA-MB-231 and MCF-7, which express lower levels of EGFR. Similarly, the viability of EGFR-expressing cells was suppressed by Fcy-hEGF in the presence of increasing concentrations of 5-FC, and the IC{sub 50} values for A431 and MDA-MB-468 were approximately 10-fold lower than those of MDA-MB-231 and MCF-7. This novel prodrug system, Fcy-hEGF/5-FC, might represent a promising addition to the available class of inhibitors that specifically target EGFR

  3. 5-Fluorocytosine combined with Fcy–hEGF fusion protein targets EGFR-expressing cancer cells

    Highlights: ► EGFR-expressing epithelial cancers account for significant portion of cancer deaths. ► EGF–EGFR signaling pathway is validated as an important anticancer drug target. ► EGF and Fcy fusion protein (Fcy–hEGF) can bind to EGFR and convert 5-FC to 5-FU. ► Fcy–hEGF combined with 5-FC preferentially inhibits EGFR-expressing cells viability. -- Abstract: Human epithelial cancers account for approximately 50% of all cancer deaths. This type of cancer is characterized by excessive activation and expression of the epidermal growth factor receptor (EGFR). The EGFR pathway is critical for cancer cell proliferation, survival, metastasis and angiogenesis. The EGF–EGFR signaling pathway has been validated as an important anticancer drug target. Increasing numbers of targeted therapies against this pathway have been either approved or are currently under development. Here, we adopted a prodrug system that uses 5-fluorocytosine (5-FC) and human EGF (hEGF) fused with yeast cytosine deaminase (Fcy) to target EGFR-overexpressing cancer cells and to convert 5-FC to a significantly more toxic chemotherapeutic, 5-fluorouracil (5-FU). We cloned and purified the Fcy–hEGF fusion protein from Pichia pastoris yeast. This fusion protein specifically binds to EGFR with a similar affinity as hEGF, approximately 10 nM. Fcy–hEGF binds tightly to A431 and MDA-MB-468 cells, which overexpress EGFR, but it binds with a lower affinity to MDA-MB-231 and MCF-7, which express lower levels of EGFR. Similarly, the viability of EGFR-expressing cells was suppressed by Fcy–hEGF in the presence of increasing concentrations of 5-FC, and the IC50 values for A431 and MDA-MB-468 were approximately 10-fold lower than those of MDA-MB-231 and MCF-7. This novel prodrug system, Fcy–hEGF/5-FC, might represent a promising addition to the available class of inhibitors that specifically target EGFR-expressing cancers.

  4. EGFR and its mutant EGFRvIII as modulators of tumor cell radiosensitivity

    Purpose: Exposure of human carcinoma and malignant glioma cells to ionizing radiation (IR)activates EGFR,which as a consequence mediates a cytoprotective response. We have demonstrated that expression of a dominant negative mutant, EGFR-CD533 disrupts this cytoprotective response, resulting in significant radiosensitization. During studies of in vivo radiosensitization with intratumoral delivery of the Adenovirus (Ad) vector, Ad-EGFR-CD533, it became apparent that xenografts from human carcinoma and malignant glioma cells invariably expressed the constitutively active EGFR mutant, EGFRvIII. This mutant EGFRvIII is frequently found in vivo in glioblastoma, breast, prostate, lung and ovarian carcinoma, but does not appear to be expressed in tumor cells under in vitro conditions. The functional consequences of EGFRvIII expression on tumor cell radiation responses are currently unknown. We have therefore investigated in a transient transfection cell system the responses of EGFRvIII and downstream signal transduction pathways to IR. In addition, the capacity of EGFR-CD533 to disrupt the function of EGFRvIII was tested. Materials and Methods: The MDA-MB-231, U-87 MG and U-373 MG cell lines were established as tumors and then intratumorally transduced with Ad-EGFR-CD533 or Ad-LacZ (control vector). The transduction efficiency was > 40% in MDA-MB-231 tumors and reached > 70% in the glioma xenografts. Radiosensitivity was measured by ex vivo colony formation and growth delay assays. The functional consequences of EGFRvIII expression on cellular IR responses were studied in transiently transfected Chinese hamster ovary (CHO) cells because tumor cells do not express EGFRvIII in vitro. Transfection with null vectors and vectors encoding either EGFRvIII or EGFR were performed and similar protein expression levels were verified by Western blot analyses. Results: The radiosensitivity of Ad-EGFR-CD533 transduced tumors was significantly increased compared with Ad-LacZ transduced

  5. Alternative packing of EGFR transmembrane domain suggests that protein-lipid interactions underlie signal conduction across membrane.

    Bocharov, Eduard V; Lesovoy, Dmitry M; Pavlov, Konstantin V; Pustovalova, Yulia E; Bocharova, Olga V; Arseniev, Alexander S

    2016-06-01

    The human epidermal growth factor receptor (EGFR) of HER/ErbB receptor tyrosine kinase family mediates a broad spectrum of cellular responses transducing biochemical signals via lateral dimerization in plasma membrane, while inactive receptors can exist in both monomeric and dimeric forms. Recently, the dimeric conformation of the helical single-span transmembrane domains of HER/ErbB employing the relatively polar N-terminal motifs in a fashion permitting proper kinase activation was experimentally determined. Here we describe the EGFR transmembrane domain dimerization via an alternative weakly polar C-terminal motif A(661)xxxG(665) presumably corresponding to the inactive receptor state. During association, the EGFR transmembrane helices undergo a structural adjustment with adaptation of inter-molecular polar and hydrophobic interactions depending upon the surrounding membrane properties that directly affect the transmembrane helix packing. This might imply that signal transduction through membrane and allosteric regulation are inclusively mediated by coupled protein-protein and protein-lipid interactions, elucidating paradoxically loose linkage between ligand binding and kinase activation. PMID:26903218

  6. Germ-line mutations in epidermal growth factor receptor (EGFR) are rare but may contribute to oncogenesis: A novel germ-line mutation in EGFR detected in a patient with lung adenocarcinoma

    A subset of lung cancer patients harbour EGFR somatic mutations in their tumours and are candidates for treatment with EGFR tyrosine kinase inhibitors. In a few cases EGFR mutations have also been found in the germ line, suggesting a role in lung carcinogenesis. Objetives of this study were: 1) To analyze the EGFR gene mutations in a population diagnosed with lung adenocarcinoma from Northern Spain. 2) To determine the frequency of a new germ-line mutation found in our laboratory as well as the frequency in our population of three other EGFR germ-line mutations detected by other authors. 3) To determine whether the novel mutation detected may have a functional effect on the EGFR protein. Tumour DNA samples were obtained from frozen or paraffin embedded tumour tissues. Samples of DNA from peripheral blood cells were obtained from 912 individuals with lung cancer recruited from the CAPUA study [1,2], 477 unrelated healthy donor individuals and 32 individuals with other types of cancer. EGFR gene exons 18 to 21 were studied by direct standard dideoxy sequencing. Specific mutations were determined either by direct sequencing or by specific RFLP analysis. Cell lines were transfected with EGFR-mutant plasmids and analysed by western blot with antibodies specific for total or phosphorylated-EGFR. We found EGFR mutation in 12 of the 71 tumour samples (17%). One tumour contained two mutations. One mutation (p.R776G) was present as a germ line. Using an RFLP analysis, this mutation was not found in 954 alleles from healthy individuals studied, concluding that it is not a polymorphism. The mutation was not found either in genomic DNA from 912 lung cancer patients. Three additional EGFR germ-line mutations that were already described were not found in any of the studied samples. These observations show that EGFR mutated alleles are rare in the population. In vitro studies revealed that tyrosine autophosphorylation is enhanced in p.R776G-mutant EGFR when compared with wild

  7. Heterogeneous EGFR gene copy number increase is common in colorectal cancer and defines response to anti-EGFR therapy.

    Ålgars, Annika; Avoranta, Tuulia; Österlund, Pia; Lintunen, Minnamaija; Sundström, Jari; Jokilehto, Terhi; Ristimäki, Ari; Ristamäki, Raija; Carpén, Olli

    2014-01-01

    Anti-EGFR therapy is commonly used to treat colorectal cancer (CRC), although only a subset of patients benefit from the treatment. While KRAS mutation predicts non-responsiveness, positive predictive markers are not in clinical practice. We previously showed that immunohistochemistry (IHC)-guided EGFR gene copy number (GCN) analysis may identify CRC patients benefiting from anti-EGFR treatment. Here we tested the predictive value of such analysis in chemorefractory metastatic CRC, elucidated EGFR GCN heterogeneity within the tumors, and evaluated the association between EGFR GCN, KRAS status, and anti-EGFR antibody response in CRC cell lines. The chemorefractory patient cohort consisted of 54 KRAS wild-type (WT) metastatic CRC patients. EGFR GCN status was analyzed by silver in situ hybridization using a cut-off value of 4.0 EGFR gene copies/cell. KRAS-WT and KRAS mutant CRC cell lines with different EGFR GCN were used in in vitro studies. The chemorefractory CRC tumors with EGFR GCN increase (≥4.0) responded better to anti-EGFR therapy than EGFR GCN (<4.0) tumors (clinical benefit, P = 0.0004; PFS, HR = 0.23, 95% CI 0.12-0.46). EGFR GCN counted using EGFR IHC guidance was significantly higher than the value from randomly selected areas verifying intratumoral EGFR GCN heterogeneity. In CRC cell lines, EGFR GCN correlated with EGFR expression. Best anti-EGFR response was seen with KRAS-WT, EGFR GCN = 4 cells and poorest response with KRAS-WT, EGFR GCN = 2 cells. Anti-EGFR response was associated with AKT and ERK1/2 phosphorylation, which was effectively inhibited only in cells with KRAS-WT and increased EGFR GCN. In conclusion, IHC-guided EGFR GCN is a promising predictor of anti-EGFR treatment efficacy in chemorefractory CRC. PMID:24940619

  8. Heterogeneous EGFR Gene Copy Number Increase Is Common in Colorectal Cancer and Defines Response to Anti-EGFR Therapy

    Ålgars, Annika; Lintunen, Minnamaija; Sundström, Jari; Jokilehto, Terhi; Ristimäki, Ari; Ristamäki, Raija; Carpén, Olli

    2014-01-01

    Anti-EGFR therapy is commonly used to treat colorectal cancer (CRC), although only a subset of patients benefit from the treatment. While KRAS mutation predicts non-responsiveness, positive predictive markers are not in clinical practice. We previously showed that immunohistochemistry (IHC)-guided EGFR gene copy number (GCN) analysis may identify CRC patients benefiting from anti-EGFR treatment. Here we tested the predictive value of such analysis in chemorefractory metastatic CRC, elucidated EGFR GCN heterogeneity within the tumors, and evaluated the association between EGFR GCN, KRAS status, and anti-EGFR antibody response in CRC cell lines. The chemorefractory patient cohort consisted of 54 KRAS wild-type (WT) metastatic CRC patients. EGFR GCN status was analyzed by silver in situ hybridization using a cut-off value of 4.0 EGFR gene copies/cell. KRAS-WT and KRAS mutant CRC cell lines with different EGFR GCN were used in in vitro studies. The chemorefractory CRC tumors with EGFR GCN increase (≥4.0) responded better to anti-EGFR therapy than EGFR GCN (<4.0) tumors (clinical benefit, P = 0.0004; PFS, HR = 0.23, 95% CI 0.12–0.46). EGFR GCN counted using EGFR IHC guidance was significantly higher than the value from randomly selected areas verifying intratumoral EGFR GCN heterogeneity. In CRC cell lines, EGFR GCN correlated with EGFR expression. Best anti-EGFR response was seen with KRAS-WT, EGFR GCN = 4 cells and poorest response with KRAS-WT, EGFR GCN = 2 cells. Anti-EGFR response was associated with AKT and ERK1/2 phosphorylation, which was effectively inhibited only in cells with KRAS-WT and increased EGFR GCN. In conclusion, IHC-guided EGFR GCN is a promising predictor of anti-EGFR treatment efficacy in chemorefractory CRC. PMID:24940619

  9. Dermatologic Toxicities from Monoclonal Antibodies and Tyrosine Kinase Inhibitors against EGFR: Pathophysiology and Management

    Shaad E. Abdullah

    2012-01-01

    Full Text Available Epidermal growth factor receptor (EGFR inhibition has now been well established as an effective treatment for various cancers. The EGFR belongs to the ErbB family of tyrosine kinase receptors which regulate tumor cell differentiation, survival and proliferation. Activation of EGFR drives tumorigenesis in lung, head and neck, colorectal and pancreatic cancers. Irrespective of the type of cancer being treated and the mechanism by which tumor EGFR drives tumorigenesis, the major side effect of EGFR inhibition is a papulopustular (also described as maculopapular or acneiform rash which occurs in about two thirds of treated patients. Interestingly, this rash has been commonly correlated with better clinical outcomes (objective tumor response and patient survival. The pathophysiology of dermatological toxicity from EGFR inhibitors is an important area of clinical research, and the proper management of the rash is essential to increase the therapeutic index from this class of drugs. In this paper, we review the dermatologic toxicities associated with EGFR inhibitors with an emphasis on its pathophysiology and clinical management.

  10. Evaluation of radiolabeled ML04, a putative irreversible inhibitor of epidermal growth factor receptor, as a bioprobe for PET imaging of EGFR-overexpressing tumors

    Overexpression of epidermal growth factor receptor (EGFR) has been implicated in tumor development and malignancy. Evaluating the degree of EGFR expression in tumors could aid in identifying patients for EGFR-targeted therapies and in monitoring treatment. Nevertheless, no currently available assay can reliably quantify receptor content in tumors. Radiolabeled inhibitors of EGFR-TK could be developed as bioprobes for positron emission tomography imaging. Such imaging agents would not only provide a noninvasive quantitative measurement of EGFR content in tumors but also serve as radionuclide carriers for targeted radiotherapy. The potency, reversibility, selectivity and specific binding characteristics of ML04, an alleged irreversible inhibitor of EGFR, were established in vitro. The distribution of the F-18-labeled compound and the extent of EGFR-specific tumor uptake were evaluated in tumor-bearing mice. ML04 demonstrated potent, irreversible and selective inhibition of EGFR, combined with specific binding to the receptor in intact cells. In vivo distribution of the radiolabeled compound revealed tumor/blood and tumor/muscle activity uptake ratios of about 7 and 5, respectively, 3 h following administration of a radiotracer. Nevertheless, only minor EGFR-specific uptake of the compound was detected in these studies, using either EGFR-negative tumors or blocking studies as controls. To improve the in vivo performance of ML04, administration via prolonged intravenous infusion is proposed. Detailed pharmacokinetic characterization of this bioprobe could assist in the development of a kinetic model that would afford accurate measurement of EGFR content in tumors

  11. AZD8931, an equipotent, reversible inhibitor of signaling by epidermal growth factor receptor (EGFR), HER2, and HER3: preclinical activity in HER2 non-amplified inflammatory breast cancer models

    Mu, Zhaomei; Klinowska, Teresa; Dong, Xiaoshen; Foster, Emily; Womack, Chris; Fernandez, Sandra V.; Cristofanilli, Massimo

    2014-01-01

    Introduction Epidermal growth factor receptor (EGFR) overexpression has been associated with prognostic and predictive value in inflammatory breast cancer (IBC). Epidermal growth factor receptor 2 (HER2) overexpression is observed at a higher rate in IBC compared with noninflammatory breast cancer. Current clinically available anti-HER2 therapies are effective only in patients with HER2 amplified breast cancer, including IBC. AZD8931 is a novel small-molecule equipotent inhibitor of EGFR, HER...

  12. Combination of afatinib with cetuximab in patients with EGFR-mutant non-small-cell lung cancer resistant to EGFR inhibitors

    Ribeiro Gomes J

    2015-05-01

    Full Text Available Jéssica Ribeiro Gomes, Marcelo Rocha S Cruz Antonio Ermirio de Moraes Oncology Center, São Paulo-Brazil Abstract: Tyrosine kinase inhibitors (TKIs targeting the epidermal growth factor receptor (EGFR have shown effectiveness for advanced non-small-cell lung cancer (NSCLC with activating mutations in the EGFR gene. However, resistance to the EGFR TKIs develops mostly secondary to T790M mutation in exon 20. The use of afatinib associated with cetuximab represents a new possibility of therapy following progression on gefitinib or erlotinib. We present two patients who acquired resistance to first-generation TKI and who underwent combination treatment with afatinib plus cetuximab as third-line therapy. Both patients presented partial response, and the time duration of disease control was 8 months and 10 months. The combined use of afatinibplus cetuximab emerges as a new possibility for the treatment of patients with advanced NSCLC harboring mutated EGFR after progression on first-generation EGFR TKIs with consequently acquired resistance to TKIs. Further studies are necessary to consolidate the data. Keywords: lung cancer, non-small-cell lung cancer, EGFR, afatinib, cetuximab, case report 

  13. Radiohalogenated 4-anilinoquinazoline-based EGFR-TK inhibitors as potential cancer imaging agents

    Introduction: The overexpression of epidermal growth factor receptor (EGFR) in tumors underlines the recent interest in EGFR as attractive target for the development of new cancer imaging agents. EGFR-tyrosine kinase inhibitors (EGFR-TKIs) based on the anilinoquinazoline scaffold have been explored as potential probes for EGFR imaging. However, up to now, no optimal radiotracer is available. Herein, we report the synthesis and biological evaluation of three novel halogenated 6-substituted 4-anilinoquinazoline based EGFR-TKIs. Radiosynthesis (125I and 18F) of the corresponding analogues was also performed. Methods: 6a, 6b and 8 were obtained by reaction of 6-amino-4-anilinoquinazoline (5) with 3-/4-iodobenzoyl and 4-fluorobenzoyl chlorides. Inhibition of EGFR autophosphorylation and A431 cellular proliferation were assessed by Western blot and MTT assays. 125I-anilinoquinazolines [125I]6a/b were prepared via destannylation of the corresponding tributylstannyl precursors with [125I]NaI. Cellular uptake studies were conducted in A431 cells. Optimization of the radiosynthesis of the 18F-anilinoquinazoline [18F]8 was attempted by nucleophilic substitution of the trimethylammonium- and nitro-6-substituted 4-anilinoquinazoline precursors. Results: 6a, 6b and 8 were synthesized in high chemical yield. All of them are inhibitors of EGFR autophosphorylation (0.15050125I]6a/b, obtained in high radiochemical purity and specific activity, were highly taken up by A431 cells. Biodistribution profile in mice indicated fast blood clearance and hepatobiliary excretion. Despite all attempts, [18F]8 was only formed in 4% yield, hampering further biological evaluation. Conclusions: This study suggests that these quinazoline derivatives can act as EGFR-TKI, warranting further modifications in the chemical structure in order to be explored as potential molecular imaging agents for single photon emission computerized tomography and positron emission tomography.

  14. Sym004, a Novel EGFR Antibody Mixture, Can Overcome Acquired Resistance to Cetuximab1

    Iida, Mari; Brand, Toni M; Starr, Megan M.; Li, Chunrong; Huppert, Evan J; Luthar, Neha; Pedersen, Mikkel W; Horak, Ivan D.; Kragh, Michael; Wheeler, Deric L

    2013-01-01

    The epidermal growth factor receptor (EGFR) is a central regulator of tumor progression in a variety of human cancers. Cetuximab is an anti-EGFR monoclonal antibody that has been approved for head and neck and colorectal cancer treatment, but many patients treated with cetuximab don't respond or eventually acquire resistance. To determine how tumor cells acquire resistance to cetuximab, we previously developed a model of acquired resistance using the non-small cell lung cancer line NCI-H226. ...

  15. Sym004, a Novel EGFR Antibody Mixture, Can Overcome Acquired Resistance to Cetuximab

    Mari Iida; Brand, Toni M; Starr, Megan M.; Chunrong Li; Huppert, Evan J; Neha Luthar; Pedersen, Mikkel W; Horak, Ivan D.; Michael Kragh; Wheeler, Deric L

    2013-01-01

    The epidermal growth factor receptor (EGFR) is a central regulator of tumor progression in a variety of human cancers. Cetuximab is an anti-EGFR monoclonal antibody that has been approved for head and neck and colorectal cancer treatment, but many patients treated with cetuximab don't respond or eventually acquire resistance. To determine how tumor cells acquire resistance to cetuximab, we previously developed a model of acquired resistance using the non-small cell lung cancer line NCI-H226. ...

  16. Determination of proteolytic activity in cereals

    D. Wojciechowska

    2015-05-01

    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.

  17. AZD9291 overcomes T790 M-mediated resistance through degradation of EGFR(L858R/T790M) in non-small cell lung cancer cells.

    Ku, Bo Mi; Bae, Yeon-Hee; Koh, Jiae; Sun, Jong-Mu; Lee, Se-Hoon; Ahn, Jin Seok; Park, Keunchil; Ahn, Myung-Ju

    2016-08-01

    The discovery of activating mutations of epidermal growth factor receptor (EGFR) has resulted in the development of more effective treatments for non-small cell lung cancer (NSCLC). Although first-generation EGFR tyrosine kinase inhibitors (EGFR TKIs) provide significant clinical benefit, acquired resistance often occurs, most commonly (>50 %) via a T790 M resistance mutation. Although AZD9291 is selective for both T790 M and activating EGFR mutations over wild-type EGFR, it is highly active when T790 M is present, especially EGFR(L858R/T790M), and modestly active when T790 M is absent. The aim of this study was to elucidate the underlying mechanism of the high sensitivity of NSCLC cells harboring EGFR(L858R/T790M) to AZD9291. In H1975 cells harboring EGFR(L858R/T790M), AZD9291 potently inhibited cellular growth and EGFR signaling pathways together with depletion of mutant EGFR protein. AZD9291-induced depletion of EGFR(L858R/T790M) protein was abrogated through inhibition of the proteasome with MG132. However, AZD9291 had no effect on protein levels of EGFR(WT) and EGFR(L858R). In addition, AZD9291 induced apoptosis and caused expression changes in cell cycle-related genes. Moreover, oral administration of AZD9291 as a single agent induced tumor regression in vivo in a H1975 tumor xenograft model and reduced EGFR(L858R/T790M) protein levels in xenograft tumors. Taken together, our results provide a potential mechanism for the sensitivity of EGFR(L858R/T790M) cells to AZD9291 and suggest that AZD9291 may be effective in cases of T790 M-positive EGFR resistance. PMID:27044261

  18. Pharmacological inhibition of EGFR signaling enhances G-CSF-induced hematopoietic stem cell mobilization.

    Ryan, Marnie A; Nattamai, Kalpana J; Xing, Ellen; Schleimer, David; Daria, Deidre; Sengupta, Amitava; Köhler, Anja; Liu, Wei; Gunzer, Matthias; Jansen, Michael; Ratner, Nancy; Le Cras, Timothy D; Waterstrat, Amanda; Van Zant, Gary; Cancelas, Jose A; Zheng, Yi; Geiger, Hartmut

    2010-10-01

    Mobilization of hematopoietic stem and progenitor cells (HSPCs) from bone marrow into peripheral blood by the cytokine granulocyte colony-stimulating factor (G-CSF) has become the preferred source of HSPCs for stem cell transplants. However, G-CSF fails to mobilize sufficient numbers of stem cells in up to 10% of donors, precluding autologous transplantation in those donors or substantially delaying transplant recovery time. Consequently, new regimens are needed to increase the number of stem cells in peripheral blood upon mobilization. Using a forward genetic approach in mice, we mapped the gene encoding the epidermal growth factor receptor (Egfr) to a genetic region modifying G-CSF-mediated HSPC mobilization. Amounts of EGFR in HSPCs inversely correlated with the cells' ability to be mobilized by G-CSF, implying a negative role for EGFR signaling in mobilization. In combination with G-CSF treatment, genetic reduction of EGFR activity in HSPCs (in waved-2 mutant mice) or treatment with the EGFR inhibitor erlotinib increased mobilization. Increased mobilization due to suppression of EGFR activity correlated with reduced activity of cell division control protein-42 (Cdc42), and genetic Cdc42 deficiency in vivo also enhanced G-CSF-induced mobilization. Our findings reveal a previously unknown signaling pathway regulating stem cell mobilization and provide a new pharmacological approach for improving HSPC mobilization and thereby transplantation outcomes. PMID:20871610

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

    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. 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. 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. 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

  20. IGFBP2 potentiates nuclear EGFR-STAT3 signaling

    Chua, Corrine Yingxuan; Liu, Yuexin; Granberg, Kirsi J.; Hu, Limei; Haapasalo, Hannu; Annala, Matti J.; Cogdell, David E.; Verploegen, Maartje; Moore, Lynette M.; Fuller, Gregory N.; Nykter, Matti; Cavenee, Webster K.; Zhang, Wei

    2015-01-01

    Insulin-like growth factor binding protein 2 (IGFBP2) is a pleiotropic oncogenic protein that has both extracellular and intracellular functions. Despite a clear causal role in cancer development, the tumor-promoting mechanisms of IGFBP2 are poorly understood. The contributions of intracellular IGFBP2 to tumor development and progression are also unclear. Here we present evidence that both exogenous IGFBP2 treatment and cellular IGFBP2 overexpression lead to aberrant activation of EGFR, which...

  1. The epidermal growth factor receptor (EGFR in head and neck cancer: its role and treatment implications

    Azria David

    2006-05-01

    Full Text Available Abstract Epidermal growth factor receptor (EGFR is a member of the ErbB family of receptors. Its stimulation by endogenous ligands, EGF or transforming growth factor-alpha (TGF-α results in activation of intracellular tyrosine kinase, therefore, cell cycle progression. High levels of EGFR expression are correlated with poor prognosis and resistance to radiation therapy in a variety of cancers, mostly in squamous-cell carcinoma of the head and neck (SCCHN. Blocking the EGFR by a monoclonal antibody results in inhibition of the stimulation of the receptor, therefore, in inhibition of cell proliferation, enhanced apoptosis, and reduced angiogenesis, invasiveness and metastases. The EGFR is a prime target for new anticancer therapy in SCCHN, and other agents in development include small molecular tyrosine kinase inhibitors and antisense therapies.

  2. The epidermal growth factor receptor (EGFR) in head and neck cancer: its role and treatment implications

    Epidermal growth factor receptor (EGFR) is a member of the ErbB family of receptors. Its stimulation by endogenous ligands, EGF or transforming growth factor-alpha (TGF-α) results in activation of intracellular tyrosine kinase, therefore, cell cycle progression. High levels of EGFR expression are correlated with poor prognosis and resistance to radiation therapy in a variety of cancers, mostly in squamous-cell carcinoma of the head and neck (SCCHN). Blocking the EGFR by a monoclonal antibody results in inhibition of the stimulation of the receptor, therefore, in inhibition of cell proliferation, enhanced apoptosis, and reduced angiogenesis, invasiveness and metastases. The EGFR is a prime target for new anticancer therapy in SCCHN, and other agents in development include small molecular tyrosine kinase inhibitors and antisense therapies

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

    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

  4. Gallic acid abolishes the EGFR/Src/Akt/Erk-mediated expression of matrix metalloproteinase-9 in MCF-7 breast cancer cells.

    Chen, Ying-Jung; Lin, Ku-Nan; Jhang, Li-Mei; Huang, Chia-Hui; Lee, Yuan-Chin; Chang, Long-Sen

    2016-05-25

    Several studies have revealed that natural compounds are valuable resources to develop novel agents against dysregulation of the EGF/EGFR-mediated matrix metalloproteinase-9 (MMP-9) expression in cancer cells. In view of the findings that EGF/EGFR-mediated MMP-9 expression is closely related to invasion and metastasis of breast cancer. To determine the beneficial effects of gallic acid on the suppression of breast cancer metastasis, we explored the effect of gallic acid on MMP-9 expression in EGF-treated MCF-7 breast cancer cells. Treatment with EGF up-regulated MMP-9 mRNA and protein levels in MCF-7 cells. EGF treatment induced phosphorylation of EGFR and elicited Src activation, subsequently promoting Akt/NFκB (p65) and ERK/c-Jun phosphorylation in MCF-7 cells. Activation of Akt/p65 and ERK/c-Jun was responsible for the MMP-9 up-regulation in EGF-treated cells. Gallic acid repressed the EGF-induced activation of EGFR and Src; furthermore, inactivation of Akt/p65 and ERK/c-Jun was a result of the inhibitory effect of gallic acid on the EGF-induced MMP-9 up-regulation. Over-expression of constitutively active Akt and MEK1 or over-expression of constitutively active Src eradicated the inhibitory effect of gallic acid on the EGF-induced MMP-9 up-regulation. A chromosome conformation capture assay showed that EGF induced a chromosomal loop formation in the MMP-9 promoter via NFκB/p65 and AP-1/c-Jun activation. Treatment with gallic acid, EGFR inhibitor, or Src inhibitor reduced DNA looping. Taken together, our data suggest that gallic acid inhibits the activation of EGFR/Src-mediated Akt and ERK, leading to reduced levels of p65/c-Jun-mediated DNA looping and thus inhibiting MMP-9 expression in EGF-treated MCF-7 cells. PMID:27087131

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

    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.

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

    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. 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. 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 < 0.001). 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

  7. Determination of proteolytic activity in cereals

    D. Wojciechowska; J. Kączkowski

    2015-01-01

    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 descri...

  8. Fighting cancer drug resistance: Opportunities and challenges for mutation-specific EGFR inhibitors.

    Juchum, Michael; Günther, Marcel; Laufer, Stefan A

    2015-05-01

    Multiple mutations in the EGFR gene are a major cause for the failure of Erlotinib and Gefitinib in the treatment of patients harboring non-small-cell lung cancer (NSCLC) who initially responded to this therapy. The development of these tyrosine kinase inhibitors (TKIs) is going back to the early 90s, where cancer was widely considered and fully treated as a disease of an organ. Fundamental gain of knowledge in cell biology in general and cancer genetics in particular led us to where we currently stand: cancer is a disease that originates in the genome. Fast and affordable gene sequencing paved the way and opened our eyes for the genetic instability of many cancers, particularly EGFR driven NSCLC. This might allow highly rational and personal therapies by aiming at a very particular wild type and mutant kinase pattern. However, the paradigm "one disease - one target - one drug" is currently challenged. Both activating and deactivating EGFR mutations are known to render the development of novel targeted drugs difficult. Among all lung adenocarcinomas, only 20% are driven by EGFR and only a subpopulation has an activating mutation (e.g. L858R), making them sensitive to first generation EGFR inhibitors. Unfortunately, most of them acquire second deactivating mutations (e.g. T790M) during treatment, leading to a complete loss of response. Are specific inhibitors of the double EGFR mutant L858R/T790M the magic bullet? Much scientific evidence but also high expectations justify this approach. Structural biology of EGFR mutants constitutes the basis for highly rational approaches. Second generation pan EGFR inhibitors inhibiting wild type (WT) and mutant EGFR like Afatinib suffer from dose-limiting adverse effects. Inhibition of WT EGFR is considered to be the culprit. Third generation EGFR inhibitors follow two strategies. Mutant selectivity and improved target residential time. These inhibitors display high mutant selectivity and irreversible binding patterns while

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

    Masayuki Nitta

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

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

    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. PMID:24700819

  11. 18F-FDG uptake for prediction EGFR mutation status in non-small cell lung cancer.

    Guan, Jian; Xiao, Nan J; Chen, Min; Zhou, Wen L; Zhang, Yao W; Wang, Shuang; Dai, Yong M; Li, Lu; Zhang, Yue; Li, Qin Y; Li, Xiang Z; Yang, Mi; Wu, Hu B; Chen, Long H; Liu, Lai Y

    2016-07-01

    Epidermal growth factor receptor (EGFR) mutations in non-small cell lung cancer (NSCLC) are a response to EGFR-tyrosine kinase inhibitor. However, a lack of sufficient tumor tissue has been a limitation for determining EGFR mutation status in clinical practice. The objective of this study was to predict EGFR mutation status in NSCLC patients based on a model including maximum standardized uptake value (SUVmax) and clinical features.We retrospectively reviewed NSCLC patients undergoing EGFR mutation testing and pretreatment positron emission tomography/computed tomography between March 2009 and December 2013. The relationships of EGFR mutations with both SUVmax and patient characteristics were evaluated, and a multivariate logistic regression analysis was performed. The model was assessed by area under the receiver-operating characteristic curve (AUC) and was prospectively validated during January to June 2014.Three hundred and sixteen patients meeting the criteria were enrolled for model construction. The SUVmax values were significantly lower for EGFR mutations (mean, 9.5 ± 5.74) than for EGFR wild-type (mean, 12.7 ± 6.43; P tests are not available. PMID:27472739

  12. EGFR-Mutant Lung Adenocarcinoma Mimicking a Pneumonia

    Álvaro Taus

    2012-01-01

    Full Text Available PET-CT scan has demonstrated to be very effective in lung cancer diagnosis and staging, but lung cancer has multiple ways of presentation, which can lead to an error in diagnosis imaging and a delay on the beginning of specific treatment. We present a case of a 77-year-old man with an initial PET-CT scan showing high 18F-FDG intake, suggesting a bilateral pneumonia, who was finally diagnosed of an EGFR-mutant lung adenocarcinoma. EGFR-activating mutation allowed us to start treatment with the oral tyrosin kinase inhibitor Gefitinib, obtaining a rapid and sustained response. Histological confirmation of imaging findings is always necessary to avoid diagnostic errors.

  13. Genetic variations of the A13/A14 repeat located within the EGFR 3′ untranslated region have no oncogenic effect in patients with colorectal cancer

    The EGFR 3′ untranslated region (UTR) harbors a polyadenine repeat which is polymorphic (A13/A14) and undergoes somatic deletions in microsatellite instability (MSI) colorectal cancer (CRC). These mutations could be oncogenic in colorectal tissue since they were shown to result into increased EGFR mRNA stability in CRC cell lines. First, we determined in a case control study including 429 CRC patients corresponding to different groups selected or not on age of tumor onset and/or familial history and/or MSI, whether or not, the germline EGFR A13/A14 polymorphism constitutes a genetic risk factor for CRC; second, we investigated the frequency of somatic mutations of this repeat in 179 CRC and their impact on EGFR expression. No statistically significant difference in allelic frequencies of the EGFR polyA repeat polymorphism was observed between CRC patients and controls. Somatic mutations affecting the EGFR 3′UTR polyA tract were detected in 47/80 (58.8%) MSI CRC versus 0/99 microsatellite stable (MSS) tumors. Comparative analysis in 21 CRC samples of EGFR expression, between tumor and non malignant tissues, using two independent methods showed that somatic mutations of the EGFR polyA repeat did not result into an EGFR mRNA increase. Germline and somatic genetic variations occurring within the EGFR 3′ UTR polyA tract have no impact on CRC genetic risk and EGFR expression, respectively. Genotyping of the EGFR polyA tract has no clinical utility to identify patients with a high risk for CRC or patients who could benefit from anti-EGFR antibodies

  14. Discovery of 5-(methylthio)pyrimidine derivatives as L858R/T790M mutant selective epidermal growth factor receptor (EGFR) inhibitors.

    Xiao, Qiang; Qu, Rong; Gao, Dingding; Yan, Qi; Tong, Linjiang; Zhang, Wei; Ding, Jian; Xie, Hua; Li, Yingxia

    2016-06-15

    To overcome the drug-resistance of first generation EGFR inhibitors and the nonselective toxicities of second generation inhibitors among NSCLC patients, a series of 5-(methylthio)pyrimidine derivatives were discovered as novel EGFR inhibitors, which harbored not only potent enzymatic and antiproliferative activities against EGFR(L858R/T790M) mutants, but good selectivity over wide-type form of the receptor. This goal was achieved by employing structure-based drug design and traditional optimization strategies, based on WZ4002 and CO1686. These derivatives inhibited the enzymatic activity of EGFR(L858R/T790M) mutants with IC50 values in subnanomolar ranges, while exhibiting hundreds of fold less potency on EGFR(WT). These compounds also strongly inhibited the proliferation of H1975 non-small cell lung cancer cells bearing EGFR(L858R/T790M), while being significantly less toxic to A431 human epithelial carcinoma cells with overexpressed EGFR(WT). The EGFR kinase inhibitory and antiproliferative activities were further validated by Western blot analysis for activation of EGFR and the downstream signaling in cancer cells. PMID:27131639

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

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

    2014-06-15

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

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

    Objective: To study fluctuations in estimated glomerular filtration rate (eGFR) in relation to contrast medium (CM) enhanced magnetic resonance imaging (MRI) and computed tomography (CT) compared to control groups in outpatients. Materials and methods: eGFR was determined right before the imaging procedure and three days later at the department or at the patient's home. The iodine-based and gadolinium-based contrast media were the same as used for all other examinations at the department. Results: A total of 716 patients completed the study. There was a statistically significant, but not clinically relevant rise in eGFR after three days in all four groups. The average eGFR variation was 4.8 ml/min/1.73 m2. There were large variations in eGFR between the two measurements in 45.8% of the patients as they had a change greater than ±10 ml/min/1.73 m2. Only three patients fulfilled the contrast-induced nephropathy (CIN) requirement when the definition s-creatinine ≥44 μmol/l (0.5 mg/dl) was used. Conclusions: eGFR in outpatients undergoing MRI or CT did vary independently of whether the patient received contrast or not. The findings probably reflect the natural variations in s-creatinine levels. This should be taken into consideration when CIN is studied

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

    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.)

  18. Properties of resistant cells generated from lung cancer cell lines treated with EGFR inhibitors

    Epidermal growth factor receptor (EGFR) signaling plays an important role in non-small cell lung cancer (NSCLC) and therapeutics targeted against EGFR have been effective in treating a subset of patients bearing somatic EFGR mutations. However, the cancer eventually progresses during treatment with EGFR inhibitors, even in the patients who respond to these drugs initially. Recent studies have identified that the acquisition of resistance in approximately 50% of cases is due to generation of a secondary mutation (T790M) in the EGFR kinase domain. In about 20% of the cases, resistance is associated with the amplification of MET kinase. In the remaining 30-40% of the cases, the mechanism underpinning the therapeutic resistance is unknown. An erlotinib resistant subline (H1650-ER1) was generated upon continuous exposure of NSCLC cell line NCI-H1650 to erlotinib. Cancer stem cell like traits including expression of stem cell markers, enhanced ability to self-renew and differentiate, and increased tumorigenicity in vitro were assessed in erlotinib resistant H1650-ER1 cells. The erlotinib resistant subline contained a population of cells with properties similar to cancer stem cells. These cells were found to be less sensitive towards erlotinib treatment as measured by cell proliferation and generation of tumor spheres in the presence of erlotinib. Our findings suggest that in cases of NSCLC accompanied by mutant EGFR, treatment targeting inhibition of EGFR kinase activity in differentiated cancer cells may generate a population of cancer cells with stem cell properties

  19. Anti-EGFR-Targeted Therapy for Esophageal and Gastric Cancers: An Evolving Concept

    Tomislav Dragovich

    2009-01-01

    Full Text Available Cancers of the esophagus and stomach present a major health burden worldwide. In the past 30 years we have witnessed some interesting shifts in terms of epidemiology of esophago gastric cancers. Regardless of a world region, the majority of patients diagnosed with esophageal or gastric cancers die from progression or recurrence of their disease. While there are many active cytotoxic agents for esophageal and stomach cancers, their impact on the disease course has been modest at best. Median survival for patients with advanced gastroesophageal cancer is still less than a year. Therefore, novel strategies, based on our understanding of biology and genetics, are desperately needed. Epidermal growth factor receptor (EGFR pathway has been implicated in pathophysiology of many epithelial malignancies, including esophageal and stomach cancers. EGFR inhibitors, small molecule tyrosine kinase inhibitors and monoclonal antibodies, have been explored in patients with esophageal and gastric cancers. It appears that tumors of the distal esophagus and gastroesophageal junction (GEJ may be more sensitive to EGFR blockade than distal gastric adenocarcinomas. Investigations looking into potential molecular predictors of sensitivity to EGFR inhibitors for patients with esophageal and GEJ cancers are ongoing. While we are still searching for those predictors, it is clear that they will be different from ones identified in lung and colorectal cancers. Further development of EGFR inhibitors for esophageal and GEJ cancers should be driven by better understanding of EGFR pathway disregulation that drives cancer progression in a sensitive patient population.

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

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

    2014-01-01

    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 1November 2003 to 1 November 2013 reporting on 18FFDG-PET response evaluation during EGFR-TKI treatment in patients with NSCLC were collected.In total 7studies,including data of 210 patients were eligible for analyses.Our report shows that FDG-PET/CT responseduring 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.

  1. Phosphoproteomics-based modeling defines the regulatory mechanism underlying aberrant EGFR signaling.

    Shinya Tasaki

    Full Text Available BACKGROUND: Mutation of the epidermal growth factor receptor (EGFR results in a discordant cell signaling, leading to the development of various diseases. However, the mechanism underlying the alteration of downstream signaling due to such mutation has not yet been completely understood at the system level. Here, we report a phosphoproteomics-based methodology for characterizing the regulatory mechanism underlying aberrant EGFR signaling using computational network modeling. METHODOLOGY/PRINCIPAL FINDINGS: Our phosphoproteomic analysis of the mutation at tyrosine 992 (Y992, one of the multifunctional docking sites of EGFR, revealed network-wide effects of the mutation on EGF signaling in a time-resolved manner. Computational modeling based on the temporal activation profiles enabled us to not only rediscover already-known protein interactions with Y992 and internalization property of mutated EGFR but also further gain model-driven insights into the effect of cellular content and the regulation of EGFR degradation. Our kinetic model also suggested critical reactions facilitating the reconstruction of the diverse effects of the mutation on phosphoproteome dynamics. CONCLUSIONS/SIGNIFICANCE: Our integrative approach provided a mechanistic description of the disorders of mutated EGFR signaling networks, which could facilitate the development of a systematic strategy toward controlling disease-related cell signaling.

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

    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

  3. A functional study of EGFR and Notch signaling in brain cancer stem-like cells from glioblastoma multiforme (Ph.d.)

    Kristoffersen, Karina

    2013-01-01

    treatment. The overall aim of the present PhD project has been to study the functional role of EGFR and Notch activity in bCSCs stem cell-like features and tumorigenic potential with the purpose of deepen our knowledge about the significance of these pathways in the bCSC population in GBM. By establishing...... expression of the mutant receptor EGFRvIII, an expression that was maintained from patient material to the xenograft tumors and cell cultures. In a culture expressing EGFR and EGFRvIII we found that EGFR inhibition induced differentiation, while forced differentiation led to down-regulation of EGFR and EGFRv......III. In addition, we showed that EGFR/EGFRvIII down regulation either as a result of induced differentiation or EGFR inhibition led to decreased in vitro tumorigenic and stem cell-like potential. In cultures expressing high levels of the Notch-1 receptor we found that Notch inhibition decreased the in...

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

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

    2014-01-01

    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......BACKGROUND: 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. 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...

  5. Activation determination of copper in food

    Neutron activation analysis was used for determining copper content in food. Analyzed were dried milk, flour, coffee, tea, husked rice, and liver. Bowen's kale powder with a guaranteed copper content of 3.6 to 6.5 ppm was used as a reference biological material. The instruments, chemicals and solutions used are reported. The method is described of copper separation with α-benzoinoxime and pyridine as is the procedure for the destructive activation analysis of samples. The copper concentrations in the foods under analysis were found to range within usual limits. The copper concentration determined in the reference material agreed with the measured value. The analysis confirms that the method yields reliable results. (J.B.)

  6. A proposed EGFR inhibitor dermatologic adverse event-specific grading scale from the MASCC skin toxicity study group

    Lacouture, Mario E.; Maitland, Michael L.; Segaert, Siegfried; Setser, Ann; Baran, Robert; Fox, Lindy P.; Epstein, Joel B.; Barasch, Andrei; Einhorn, Lawrence; Wagner, Lynne; West, Dennis P.; Rapoport, Bernardo L.; Kris, Mark G.; Basch, Ethan; Eaby, Beth; Kurtin, Sandra; Olsen, Elise A.; Chen, Alice; Dancey, Janet E.; Trotti, Andy

    2010-01-01

    Accurate grading of dermatologic adverse events (AE) due to epidermal growth factor receptor (EGFR) inhibitors (EGFRIs) is necessary for drug toxicity determinations, interagent comparisons, and supportive care trials. The most widely used severity grading scale, the National Cancer Institute's Comm

  7. Acquired EGFR C797S mutation mediates resistance to AZD9291 in non-small cell lung cancer harboring EGFR T790M.

    Thress, Kenneth S; Paweletz, Cloud P; Felip, Enriqueta; Cho, Byoung Chul; Stetson, Daniel; Dougherty, Brian; Lai, Zhongwu; Markovets, Aleksandra; Vivancos, Ana; Kuang, Yanan; Ercan, Dalia; Matthews, Sarah E; Cantarini, Mireille; Barrett, J Carl; Jänne, Pasi A; Oxnard, Geoffrey R

    2015-06-01

    Here we studied cell-free plasma DNA (cfDNA) collected from subjects with advanced lung cancer whose tumors had developed resistance to the epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) AZD9291. We first performed next-generation sequencing of cfDNA from seven subjects and detected an acquired EGFR C797S mutation in one; expression of this mutant EGFR construct in a cell line rendered it resistant to AZD9291. We then performed droplet digital PCR on serial cfDNA specimens collected from 15 AZD9291-treated subjects. All were positive for the T790M mutation before treatment, but upon developing AZD9291 resistance three molecular subtypes emerged: six cases acquired the C797S mutation, five cases maintained the T790M mutation but did not acquire the C797S mutation and four cases lost the T790M mutation despite the presence of the underlying EGFR activating mutation. Our findings provide insight into the diversity of mechanisms through which tumors acquire resistance to AZD9291 and highlight the need for therapies that are able to overcome resistance mediated by the EGFR C797S mutation. PMID:25939061

  8. Acquired EGFR C797S mediates resistance to AZD9291 in advanced non-small cell lung cancer harboring EGFR T790M

    Thress, Kenneth S.; Paweletz, Cloud P.; Felip, Enriqueta; Cho, Byoung Chul; Stetson, Daniel; Dougherty, Brian; Lai, Zhongwu; Markovets, Aleksandra; Vivancos, Ana; Kuang, Yanan; Ercan, Dalia; Matthews, Sarah; Cantarini, Mireille; Barrett, J. Carl; Jänne, Pasi A.; Oxnard, Geoffrey R.

    2015-01-01

    Here we studied cell-free plasma DNA (cfDNA) collected from subjects with advanced lung cancer whose tumors had developed resistance to the epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) AZD9291. We first performed next-generation sequencing of cfDNA from seven subjects and detected an acquired EGFR C797S mutation in one; expression of this mutant EGFR construct in a cell line rendered it resistant to AZD9291. We then performed droplet digital PCR on serial cfDNA specimens collected from 15 AZD9291-treated subjects. All were positive for T790M prior to treatment, but at resistance three molecular subtypes emerged: 6 cases acquired the C797S mutation, 5 cases maintained the T790M mutation but did not acquire the C797S mutation, and 4 cases lost the T790M mutation despite detecting of the underlying EGFR activating mutation. Our findings provide insight into the diversity of mechanisms through which tumors acquire resistance to AZD9291 and highlight the need for therapies able to overcome resistance mediated by EGFR C797S. PMID:25939061

  9. Levels of active tyrosine kinase receptor determine the tumor response to Zalypsis

    Zalypsis® is a marine compound in phase II clinical trials for multiple myeloma, cervical and endometrial cancer, and Ewing’s sarcoma. However, the determinants of the response to Zalypsis are not well known. The identification of biomarkers for Zalypsis activity would also contribute to broaden the spectrum of tumors by selecting those patients more likely to respond to this therapy. Using in vitro drug sensitivity data coupled with a set of molecular data from a panel of sarcoma cell lines, we developed molecular signatures that predict sensitivity to Zalypsis. We verified these results in culture and in vivo xenograft studies. Zalypsis resistance was dependent on the expression levels of PDGFRα or constitutive phosphorylation of c-Kit, indicating that the activation of tyrosine kinase receptors (TKRs) may determine resistance to Zalypsis. To validate our observation, we measured the levels of total and active (phosphorylated) forms of the RTKs PDGFRα/β, c-Kit, and EGFR in a new panel of diverse solid tumor cell lines and found that the IC50 to the drug correlated with RTK activation in this new panel. We further tested our predictions about Zalypsis determinants for response in vivo in xenograft models. All cells lines expressing low levels of RTK signaling were sensitive to Zalypsis in vivo, whereas all cell lines except two with high levels of RTK signaling were resistant to the drug. RTK activation might provide important signals to overcome the cytotoxicity of Zalypsis and should be taken into consideration in current and future clinical trials

  10. Determinants of Physical Activity in Active and Low-Active, Sixth Grade African-American Youth.

    Trost, Stewart G.; Pate, Russell R.; Ward, Dianne S.; Saunders, Ruth; Riner, William

    1999-01-01

    Compared determinants of physical activity in active and low-active African-American sixth graders, surveying students and making objective assessments of physical activity over seven days. Results indicated that physical activity self-efficacy, beliefs about physical activity outcomes, involvement in community-based physical activity, perception…

  11. Meta-Analysis of First-Line Therapies in Advanced Non–Small-Cell Lung Cancer Harboring EGFR-Activating Mutations

    Haaland, Benjamin; Tan, Pui San; Castro, Gilberto de; Lopes, Gilberto

    2014-01-01

    Introduction: Tyrosine kinase inhibitors gefitinib, erlotinib, and afatinib have been compared with chemotherapy as first-line therapies for patients with advanced non–small-cell lung cancer harboring epidermal growth factor receptor–activating mutations. This meta-analysis compares gefitinib, erlotinib, afatinib, and chemotherapy. Methods: Literature search was performed using relevant keywords. Direct and indirect meta-estimates were generated using log-linear mixed-effects models, with ran...

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

    Huan, Hongbo; Wen, Xudong; Chen, Xuejiao; Wu, Lili; Liu, Weihui; Habib, Nagy A.; Bie, Ping; Xia, Feng

    2016-01-01

    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-sa...

  13. Simultaneous Inhibition of EGFR and PI3K Enhances Radiosensitivity in Human Breast Cancer

    Purpose: Mutations in the epidermal growth factor receptor (EGFR)/phosphoinositide 3-kinase (PI3K)/Akt signaling transduction pathway are common in cancer. This pathway is imperative to the radiosensitivity of cancer cells. We aimed to investigate the radiosensitizing effects of the simultaneous inhibition of EGFR and PI3K in breast cancer cells. Methods and Materials: MCF-7 cell lines with low expression of EGFR and wild-type PTEN and MDA-MB-468 cell lines with high expression of EGFR and mutant PTEN were used. The radiosensitizing effects by the inhibition of EGFR with AG1478 and/or PI3K with Ly294002 were determined by colony formation assay, Western blot was used to investigate the effects on downstream signaling. Flow cytometry was used for apoptosis and cell cycle analysis. Mice-bearing xenografts of MDA-MB-468 breast cancer cells were also used to observe the radiosensitizing effect. Results: Simultaneous inhibition of EGFR and PI3K greatly enhanced radiosensitizing effect in MDA-MB-468 in terms of apoptosis and mitotic death, either inhibition of EGFR or PI3K alone could enhance radiosensitivity with a dose-modifying factor (DMFSF2) of 1.311 and 1.437, radiosensitizing effect was further enhanced by simultaneous inhibition of EGFR and PI3K with a DMFSF2 at 2.698. DNA flow cytometric analysis indicated that dual inhibition combined with irradiation significantly induced G0/G1 phase arrest in MDA-MB-468 cells. The expression of phosphor-Akt and phosphor-Erk1/2 (induced by irradiation and PI3K inhibitor) were fully attenuated by simultaneous treatment with both inhibitors in combination with irradiation. In addition, dual inhibition combined with irradiation induced dramatic tumor growth delay in MDA-MB-468 xenografts. Conclusions: Our study indicated that simultaneous inhibition of EGFR and PI3K could further sensitize the cancer cells to irradiation compared to the single inhibitor with irradiation in vitro and in vivo. The approach may have important

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

    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.

  15. EGFR/Ras Signaling Controls Drosophila Intestinal Stem Cell Proliferation via Capicua-Regulated Genes

    Jin, Yinhua; Ha, Nati; Forés, Marta; Xiang, Jinyi; Gläßer, Christine; Maldera, Julieta; Jiménez, Gerardo; Edgar, Bruce A.

    2015-01-01

    Epithelial renewal in the Drosophila intestine is orchestrated by Intestinal Stem Cells (ISCs). Following damage or stress the intestinal epithelium produces ligands that activate the epidermal growth factor receptor (EGFR) in ISCs. This promotes their growth and division and, thereby, epithelial regeneration. Here we demonstrate that the HMG-box transcriptional repressor, Capicua (Cic), mediates these functions of EGFR signaling. Depleting Cic in ISCs activated them for division, whereas overexpressed Cic inhibited ISC proliferation and midgut regeneration. Epistasis tests showed that Cic acted as an essential downstream effector of EGFR/Ras signaling, and immunofluorescence showed that Cic’s nuclear localization was regulated by EGFR signaling. ISC-specific mRNA expression profiling and DNA binding mapping using DamID indicated that Cic represses cell proliferation via direct targets including string (Cdc25), Cyclin E, and the ETS domain transcription factors Ets21C and Pointed (pnt). pnt was required for ISC over-proliferation following Cic depletion, and ectopic pnt restored ISC proliferation even in the presence of overexpressed dominant-active Cic. These studies identify Cic, Pnt, and Ets21C as critical downstream effectors of EGFR signaling in Drosophila ISCs. PMID:26683696

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

    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

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

    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).

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

    Jiao, Xin; JIN, BO; Qu, Xiujuan; Shunchao YAN; Hou, Kezuo; Liu, Yunpeng; Hu, Xuejun

    2011-01-01

    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 correlati...

  19. [Determination of riboflavin kinase activity in yeast].

    Shavlovsky, G M; Kashchenko, V E

    1975-01-01

    It is established that the main reason of the riboflavin kinase (RFK, EC 2.7.1.26) low specific activity in the cell-free extracts of the yeast Pichia guillermondii Wickerham ATCC 9058 is the presence of alkaline phosphatase (EC 3.1.3.1), effectively destructing flaven mononucleotide. By chromatography of the cell-free extracts of P. guillermondii on DEAE-Sephadex A-50, CM-Sphadex C-50, CM-cellulose, Sephadexes G-75 and G-100 RFK and alkaline phosphatase may be separated completely. Any of these procedures results in a several times increase of the RFK activity as compared with the initial preparation. One failed to obtain a similar effect by fractionation of the extracts with amminium sulphate and by hydroxylapatite chromatography. A simple method is developed for determining the activity of RFK in the cell-free extracts of yeast on the basis of negative adsorption of this enzyme on DEAE-Sephadex A-50. A selective inhibition of alkaline phosphatase by ions Be2+ and F- yields a less satisfactory result. The data are presented on the PFK activity of certain species of flavinogenic (Pichia guillermondii, Torulopsis camdida) and non-flavinogenic (Pichia ohmeri, Candida utilis, Saccharomyces cervisiae) yeast. PMID:174262

  20. Tumor-penetrating peptide fused EGFR single-domain antibody enhances cancer drug penetration into 3D multicellular spheroids and facilitates effective gastric cancer therapy

    Sha, Huizi; Zou, Zhengyun; Xin, Kai; Bian, Xinyu; Cai, Xueting; Lu, Wuguang; Chen, Jiao; Chen, Gang; Huang, Leaf; Blair, Andrew M.; Cao, Peng; Liu, Baorui

    2016-01-01

    Human tumors, including gastric cancer, frequently express high levels of epidermal growth factor receptors (EGFRs), which are associated with a poor prognosis. Targeted delivery of anticancer drugs to cancerous tissues shows potential in sparing unaffected tissues. However, it has been a major challenge for drug penetration in solid tumor tissues due to the complicated tumor microenvironment. We have constructed a recombinant protein named anti-EGFR-iRGD consisting of an anti-EGFR VHH (the variable domain from the heavy chain of the antibody) fused to iRGD, a tumor-specific binding peptide with high permeability. Anti-EGFR-iRGD, which targets EGFR and αvβ3, spreads extensively throughout both the multicellular spheroids and the tumor mass. The recombinant protein anti-EGFR-iRGD also exhibited antitumor activity in tumor cell lines, multicellular spheroids, and mice. Moreover, anti-EGFR-iRGD could improve anticancer drugs, such as doxorubicin (DOX), bevacizumab, nanoparticle permeability and efficacy in multicellular spheroids. This study draws attention to the importance of iRGD peptide in the therapeutic approach of anti-EGFR-iRGD. As a consequence, anti-EGFR-iRGD could be a drug candidate for cancer treatment and a useful adjunct of other anticancer drugs. PMID:25553823

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

    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

  2. A synonymous EGFR polymorphism predicting responsiveness to anti-EGFR therapy in metastatic colorectal cancer patients.

    Bonin, Serena; Donada, Marisa; Bussolati, Gianni; Nardon, Ermanno; Annaratone, Laura; Pichler, Martin; Chiaravalli, Anna Maria; Capella, Carlo; Hoefler, Gerald; Stanta, Giorgio

    2016-06-01

    Genetic factors are known to affect the efficiency of therapy with monoclonal antibodies (mAbs) targeting the epidermal growth factor receptor (EGFR) in patients with metastatic colorectal cancer (mCRC). At present, the only accepted molecular marker predictive of the response to anti-EGFR mAbs is the somatic mutation of KRAS and NRAS as a marker of resistance to anti-EGFR. However, only a fraction of KRAS wild-type patients benefit from that treatment. In this study, we show that the EGFR gene polymorphism rs1050171 defines, independently of RAS mutational status, a sub-population of 11 % of patients with a better clinical outcome after anti-EGFR treatment. Median PFS for patients with the GG genotype was 10.17 months compared to 5.37 of those with AG + AA genotypes. Taken together, our findings could be used to better define CRC populations responding to anti-EGFR therapy. Further studies in larger independent cohorts are necessary to validate the present observation that a synonymous polymorphism in EGFR gene impacts on clinical responsiveness. PMID:26666825

  3. Pharmacogenomics of EGFR-targeted therapies in non-small cell lung cancer:EGFR and beyond

    Christopher Delaney; Samuel Frank; R Stephanie Huang

    2015-01-01

    Commonly observed aberrations in epidermal growth factor receptor (EGFR) signaling have led to the development of EGFR-targeted therapies for various cancers, including non–small cell lung cancer (NSCLC). EGFR mutations and overexpression have further been shown to modulate sensitivity to these EGFR-targeted therapies in NSCLC and several other types of cancers. However, it is clear that mutations and/or genetic variations in EGFR alone cannot explain all of the variability in the responses of patients with NSCLC to EGFR-targeted therapies. For instance, in addition to EGFR genotype, genetic variations in other members of the signaling pathway downstream of EGFR or variations in paral el receptor tyrosine kinase (RTK) pathways are now recognized to have a significant impact on the efficacy of certain EGFR-targeted therapies. In this review, we highlight the mutations and genetic variations in such genes downstream of EGFR and in parallel RTK pathways. Specifically, the directional effects of these pharmacogenetic factors are discussed with a focus on two commonly prescribed EGFR inhibitors:cetuximab and erlotinib. The results of this comprehensive review can be used to optimize the treatment of NSCLC with EGFR inhibitors. Furthermore, they may provide the rationale for the design of subsequent combination therapies that involve the inhibition of EGFR.

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

    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.

  5. Nimotuzumab promotes radiosensitivity of EGFR-overexpression esophageal squamous cell carcinoma cells by upregulating IGFBP-3

    Zhao Lei

    2012-12-01

    Full Text Available Abstract Background Epidermal growth factor receptor (EGFR is suggested to predict the radiosensitivity and/or prognosis of human esophageal squamous cell carcinoma (ESCC. The objective of this study was to investigate the efficacy of Nimotuzumab (an anti-EGFR monoclonal antibody on ESCC radiotherapy (RT and underlying mechanisms. Methods Nimotuzumab was administrated to 2 ESCC cell lines KYSE30 and TE-1 treated with RT. Cell growth, colony formation and apoptosis were used to measure anti-proliferation effects. The method of RNA interference was used to investigate the role of insulin-like growth factor binding protein-3 (IGFBP-3 in ESCC cells radiosensitivity treated with Nimotuzumab. In vivo effect of Nimotuzumab on ESCC radiotherapy was done using a mouse xenograft model. Results Nimotuzumab enhanced radiation response of KYSE30 cells (with high EGFR expression in vitro, as evidenced by increased radiation-inhibited cell growth and colony formation and radiation-mediated apoptosis. Mechanism study revealed that Nimotuzumab inhibited phosphorylated EGFR (p-EGFR induced by EGF in KYSE30 cells. In addition, knockdown of IGFBP-3 by short hairpin RNA significantly reduced KYSE30 cells radiosensitivity (PP>0.05. In KYSE30 cell xenografts, Nimotuzumab combined with radiation led to significant tumor growth delay, compared with that of radiation alone (P=0.029, and also with IGFBP-3 up-regulation in tumor tissue. Conclusions Nimotuzumab could enhance the RT effect of ESCC cells with a functional active EGFR pathway. In particular, the increased ESCC radiosensitivity by Nimotuzumab might be dependent on the up-regulation of IGFBP-3 through EGFR-dependent pathway.

  6. Simultaneous molecular imaging of EGFR and HER2 using hyperspectral darkfield microscopy and immunotargeted nanoparticles

    Crow, Matthew J.; Marinakos, Stella; Chilkoti, Ashutosh; Wax, Adam P.

    2009-02-01

    Epidermal growth factor receptor (EGFR) and human epidermal growth factor receptor (HER2) contribute to the regulation of cell proliferation, and when jointly over-expressed are associated with several types of cancer. The ability to monitor both receptors simultaneously results in a more accurate indicator of degree of cancerous activity than either receptor alone. Plasmonic nanoparticles (NPs) show promise as a potential EGFR and HER2 biomarker over alternatives such as fluorophores and quantum dots, which are limited by their cytotoxicity and photobleaching. To observe immunolabeled NPs bound to receptor-expressing cells, our past experiments were conducted using a novel optical darkfield microspectroscopy system. We implemented an epi-illumination darkfield broadband light train, which allows for darkfield analysis of live cells in culture with enhanced NP contrast. Under this setup, molecularly specific binding of NPs immunolabeled with anti-EGFR was confirmed. We have since adapted our darkfield setup, which previously only obtained spectral information from a line imaging spectrometer, to incorporate hyperspectral imaging capabilities, allowing widefield data acquisition within seconds. The new system has been validated through observation of shifts in the peak wavelength of scattering by gold NPs on silanated cover glasses using several immersion media. Peak resonant scattering wavelengths match well with that predicted by Mie theory. We will further demonstrate the potential of the system with simultaneous molecular imaging of multiple receptors in vitro using labeled EGFR+/HER2+ SK-BR-3 human breast cancer cells with anti-EGFR immunolabeled gold nanospheres and anti-HER2 immunolabeled gold nanorods, with each scattering in different spectral windows. Additional trials will be performed to demonstrate molecularly specific binding using EGFR+/HER2- MDA-MB-468 and HER2+/EGFR- MDA-MB-453 breast cancer cells.

  7. Sensing of p53 and EGFR Biomarkers Using High Efficiency SERS Substrates

    Peter Owens

    2015-10-01

    Full Text Available In this paper we describe a method for the determination of protein concentration using Surface Enhanced Raman Resonance Scattering (SERRS immunoassays. We use two different Raman active linkers, 4-aminothiophenol and 6-mercaptopurine, to bind to a high sensitivity SERS substrate and investigate the influence of varying concentrations of p53 and EGFR on the Raman spectra. Perturbations in the spectra are due to the influence of protein–antibody binding on Raman linker molecules and are attributed to small changes in localised mechanical stress, which are enhanced by SERRS. These influences are greatest for peaks due to the C-S functional group and the Full Width Half Maximum (FWHM was found to be inversely proportional to protein concentration.

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

    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.

  9. NF-κB-driven suppression of FOXO3a contributes to EGFR mutation-independent gefitinib resistance.

    Chiu, Ching-Feng; Chang, Yi-Wen; Kuo, Kuang-Tai; Shen, Yu-Shiuan; Liu, Chien-Ying; Yu, Yang-Hao; Cheng, Ching-Chia; Lee, Kang-Yun; Chen, Feng-Chi; Hsu, Min-Kung; Kuo, Tsang-Chih; Ma, Jui-Ti; Su, Jen-Liang

    2016-05-01

    Therapy with epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (EGFR-TKIs, such as gefitinib or erlotinib) significantly prolongs survival time for patients with tumors harboring an activated mutation on EGFR; however, up to 40% of lung cancer patients exhibit acquired resistance to EGFR-TKIs with an unknown mechanism. FOXO3a, a transcription factor of the forkhead family, triggers apoptosis, but the mechanistic details involved in EGFR-TKI resistance and cancer stemness remain largely unclear. Here, we observed that a high level of FOXO3a was correlated with EGFR mutation-independent EGFR-TKI sensitivity, the suppression of cancer stemness, and better progression-free survival in lung cancer patients. The suppression of FOXO3a obviously increased gefitinib resistance and enhanced the stem-like properties of lung cancer cells; consistent overexpression of FOXO3a in gefitinib-resistant lung cancer cells reduced these effects. Moreover, we identified that miR-155 targeted the 3'UTR of FOXO3a and was transcriptionally regulated by NF-κB, leading to repressed FOXO3a expression and increased gefitinib resistance, as well as enhanced cancer stemness of lung cancer in vitro and in vivo. Our findings indicate that FOXO3a is a significant factor in EGFR mutation-independent gefitinib resistance and the stemness of lung cancer, and suggest that targeting the NF-κB/miR-155/FOXO3a pathway has potential therapeutic value in lung cancer with the acquisition of resistance to EGFR-TKIs. PMID:27091996

  10. AZD9291, an irreversible EGFR TKI, overcomes T790M-mediated resistance to EGFR inhibitors in lung cancer

    Cross, Darren A. E.; Ashton, Susan E.; Ghiorghiu, Serban; Eberlein, Cath; Nebhan, Caroline A.; Spitzler, Paula J.; Orme, Jonathon P.; Finlay, M. Raymond V.; Ward, Richard A.; Mellor, Martine J.; Hughes, Gareth; Rahi, Amar; Jacobs, Vivien N.; Brewer, Monica Red; Ichihara, Eiki

    2014-01-01

    First generation EGF receptor tyrosine kinase inhibitors (EGFR TKIs) provide significant clinical benefit in patients with advanced EGFR mutant (EGFRm+) non-small cell lung cancer (NSCLC). Patients ultimately develop disease progression, often driven by acquisition of a second T790M EGFR TKI resistance mutation. AZD9291 is a novel oral, potent and selective third generation irreversible inhibitor of both EGFRm+ sensitizing and T790M resistance mutants that spares wild-type EGFR. This monoanil...

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

    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

  12. EGFR expression level predicts response and overall survival in gastric cancer PDTX model treated with cetuximab

    2015-01-01

    Objective:hTe aim of this study was to determine whether the EGFR statuscould significantly predict some benefit in overall survival and response to cetuximab in advanced GC xenografts.Methods: Two hundred xenografts derived from 20 GC patients were established. Then they were divided into cetuximab treated group and control group randomly.Results:Among the cetuximab treated group, 4 GC cases were identified responded to cetuximab.hTose cetuximab treated PDX models had longer OS than non-treated. High EGFR mRNA expression and immunohistochemistry score are more prone to response to cetuximab. EGFR amplification, mRNA and protein overexpression were associated with the OS in cetuximab treated PDX models. Moreover, in the PDX models derived from EGFR ampliifcation, mRNA or protein overexpression cases, the OS is signiifcantly different between the cetuximab treated and control group, while the OS in not statistically different in other cases.Conclusion:EGFR status predicts sensitivity to therapy and survival in GC treated with cetuximab, especially the mRNA and protein expression level.

  13. Substoichiometric neutron activation determination of gold

    A highly precise and selective method is described for the determination of traces of gold by substoichiometric extraction from hydrochloric acid with tri-n-octylphosphine sulfide in cyclohexane following thermal neutron activation. Fundamental aspects of the extraction system are discussed and results are reported for the determination of gold in an effluent from a recovery process containing a complexed species of gold and unknown amounts of cyanide, citrate, phosphate, potassium and sodium. Other constituents of the effluent stream include traces of the transition elements Co, Ni, Fe, Cu, Zn, Pb and Sn at concentrations less than 50 ppm. One hour was allowed for the Au3+ carrier and the 198Au complexed species in samples and standards to oxidize, exchange, and reach chemical equilibrium. Samples were then equilibrated by shaking with the organic phase for thirty min. The percentage extractions (%E) for the substoichiometric separation of gold from the effluent and from the corresponding comparison standards were monitored. The mean percentage extractions for the substoichiometric separations of carrier from the effluent, and its corresponding standard were 75.3 and 59.3, respectively. These data are estimated to be accurate within +-2.0%. (T.G.)

  14. Structural Determinants of Sleeping Beauty Transposase Activity.

    Abrusán, György; Yant, Stephen R; Szilágyi, András; Marsh, Joseph A; Mátés, Lajos; Izsvák, Zsuzsanna; Barabás, Orsolya; Ivics, Zoltán

    2016-08-01

    Transposases are important tools in genome engineering, and there is considerable interest in engineering more efficient ones. Here, we seek to understand the factors determining their activity using the Sleeping Beauty transposase. Recent work suggests that protein coevolutionary information can be used to classify groups of physically connected, coevolving residues into elements called "sectors", which have proven useful for understanding the folding, allosteric interactions, and enzymatic activity of proteins. Using extensive mutagenesis data, protein modeling and analysis of folding energies, we show that (i) The Sleeping Beauty transposase contains two sectors, which span across conserved domains, and are enriched in DNA-binding residues, indicating that the DNA binding and endonuclease functions of the transposase coevolve; (ii) Sector residues are highly sensitive to mutations, and most mutations of these residues strongly reduce transposition rate; (iii) Mutations with a strong effect on free energy of folding in the DDE domain of the transposase significantly reduce transposition rate. (iv) Mutations that influence DNA and protein-protein interactions generally reduce transposition rate, although most hyperactive mutants are also located on the protein surface, including residues with protein-protein interactions. This suggests that hyperactivity results from the modification of protein interactions, rather than the stabilization of protein fold. PMID:27401040

  15. Potential crosstalk between cofilin-1 and EGFR pathways in cisplatin resistance of non-small-cell lung cancer

    Müller, Carolina Beatriz; De Bastiani, Marco Antônio; Becker, Matheus; França, Fernanda Stapenhorst; Branco, Mariane Araujo; Castro, Mauro Antônio Alves; Klamt, Fábio

    2015-01-01

    Current challenge in oncology is to establish the concept of personalized medicine in clinical practice. In this context, non-small-cell lung cancer (NSCLC) presents clinical, histological and molecular heterogeneity, being one of the most genomically diverse of all cancers. Recent advances added Epidermal Growth Factor Receptor (EGFR) as a predictive biomarker for patients with advanced NSCLC. In tumors with activating EGFR mutations, tyrosine kinase inhibitors (TKI) are indicated as first-l...

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

    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.

  17. Novel targets in HPV-negative head and neck cancer: overcoming resistance to EGFR inhibition.

    Burtness, Barbara; Bauman, Julie E; Galloway, Thomas

    2013-07-01

    Cancers of the head and neck that arise from habitual exposure to carcinogens have lower cure rates than those that arise from infection with human papillomavirus (HPV), and intensification of cytotoxic chemotherapy and radiation has not improved outcomes. HPV-negative head and neck cancers abundantly express EGFR, and the monoclonal antibody cetuximab, directed against EGFR, is the only targeted therapy that has improved disease survival so far. However, response rates to single-agent cetuximab are lower than 15%, and cetuximab given with chemotherapy or radiation leads to only a modest effect on survival. Thus, investigating the mechanisms of resistance to EGFR inhibition in HPV-negative head and neck cancer might help identify novel and active therapies. In this Review, we focus on therapies in development that target redundant receptor tyrosine kinases (eg, HER2 and MET), reduce or abrogate nuclear functions of EGFR, affect cellular trafficking by inhibition of histone deacetylase, or treatments that might address resistance that arises in the EGFR signalling stream (eg, aurora-kinase inhibitors and STAT decoys). PMID:23816296

  18. EGFR mutation frequency and effectiveness of erlotinib

    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. MATERIAL...

  19. EGFR, KRAS, BRAF, and HER-2 molecular status in brain metastases from 77 NSCLC patients

    Villalva, Claire; Duranton-Tanneur, Valérie; Guilloteau, Karline; Burel-Vandenbos, Fanny; Wager, Michel; Doyen, Jérôme,; Levillain, Pierre Marie; Fontaine, Denys; Blons, Hélène; Pedeutour, Florence; Karayan-Tapon, Lucie

    2013-01-01

    The aim of this study was to determine the frequency of EGFR, KRAS, BRAF, and HER-2 mutations in brain metastases from non-small cell lung carcinomas (BM-NSCLC). A total of 77 samples of BM-NSCLC were included and 19 samples of BM from breast, kidney, and colorectal tumors were also studied as controls. These samples were collected from patients followed between 2008 and 2011 at Poitiers and Nice University Hospitals in France. The frequencies of EGFR, KRAS, BRAF, and HER-2 mutations in BM-NS...

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

    Shuhang Wang

    Full Text Available INTRODUCTION: 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. PATIENTS AND METHODS: 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. RESULTS: 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. CONCLUSION: 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.

  1. Expression and significance of EGFR protein in model of radiation injury in mouse skin

    Objective: The expression of EGFR protein was studied by SABC immunohistochemistry in 40 cases of model of radiation injury in mouse skin. Methods: Experiment animals were divided into four groups according to radiation dose. Results: The positive rates were 27.0%, 49.3%, 72.2%, 87.6% in 5 Gy group, 15 Gy group, 30 Gy group, 45 Gy group respectively, showing significant difference (P < 0.01). While the positive rate was 10.8% in normal control group, with significant difference (P < 0.01) compared with each radiation group. Conclusion: The enhancement of expression of EGFR in accordance with the increasing of radiation dose in certain dose range might be one important factor related to c-erbB-1 gene activated and enlarged by radiation, and the overexpression of EGFR protein might be related to poor healing in radiation skin injury

  2. Synthetic Genistein Glycosides Inhibiting EGFR Phosphorylation Enhance the Effect of Radiation in HCT 116 Colon Cancer Cells

    Aleksandra Gruca

    2014-11-01

    Full Text Available The need to find new EGFR inhibitors for use in combination with radiotherapy in the treatment of solid tumors has drawn our attention to compounds derived from genistein, a natural isoflavonoid. The antiproliferative potential of synthetic genistein derivatives used alone or in combination with ionizing radiation was evaluated in cancer cell lines using clonogenic assay. EGFR phosphorylation was assessed with western blotting. Genistein derivatives inhibited clonogenic growth of HCT 116 cancer cells additively or synergistically when used in combination with ionizing radiation, and decreased EGFR activation. Our preclinical evaluation of genistein-derived EGFR inhibitors suggests that these compounds are much more potent sensitizers of cells to radiation than the parent isoflavonoid, genistein and indicate that these compounds may be useful in the treatment of colon cancer with radiation therapy.

  3. EGFR Mutation Status in Uighur Lung Adenocarcinoma Patients

    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%.

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

    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

  5. 树突状细胞活化TCR基因转染记忆性T细胞联合化疗治疗EGFR-TKI耐药性晚期非小细胞肺癌的疗效与安全性%Efficacy and safety of combining infusion of antigen-activated,TCR gene-transfected memory T cells combined with chemotherapy for treating advanced non-small cell lung cancer resistant to EGFR-TKIs

    江冠铭; 袁领勤; 贾筠; 林顺欢; 蔡彦敏; 刘淳; 吴依芬; 王在国; 黄树林

    2014-01-01

    Objective To examine whether infusion of antigen-activated memory T cells transfected with TCR genes alters the clinical efficacy and toxicity of pemetrexed-cisplatin combination chemotherapy to treatin the treatment of advanced non-small cell lung cancer resistant to EGFR-TKIs. Methods A total of 41 patients with non-small cell lung cancer were randomized into a group (n=20)that received standard chemotherapy involving a 3-week regime of pemetrexed (500 mg/m2)and cisplatin (75 mg/m2),or into a group (n=21)that received the same chemotherapy after harvesting,culturing and intravenously infusing DC-activated T cells.Curative effects,immune function,quality of life and adverse reactions were compared between the two treatments. Results Combining infu-sion of DC-activated T cells with chemotherapy significantly increased serum populations of CD3+,CD4+,CD8+,CD95+,and CD122+cells,as well as the CD4+/CD8+ ratio.Combination therapy and standard chemotherapy alone gave similar overall response rates of 33.33%and 30.00%(P>0.05),respectively,but combination therapy led to a significantly higher disease control rate(76.19%vs 60.00%, P0.05),疾病控制率分别为76.19%和60.00%(P<0.05)。中位疾病无进展时间联合治疗组为7.1个月,明显高于化疗组的3.7个月(P<0.05)。联合治疗组患者KPS评分改善率为85.71%,高于化疗组45.00%(P<0.05)。联合治疗组患者粒细胞减少、恶心呕吐和疲乏的发生率分别为46.6%、52.4%和23.8%,明显低于化疗组的75.0%、90.0%和65.0%(P<0.05)。结论负载抗原DC活化TCR基因转染记忆性T细胞联合培美曲塞、顺铂治疗EGFR-TKI耐药性晚期NSCLC的疗效较好,能提高患者免疫功能和改善生活质量,减低化疗毒副反应,安全性较好。

  6. Helicobacter pylori infection and expressions of EGF, EGFR and c-erbB-2 proteins in gastric carcinoma.

    Andrzej Kemona

    2010-02-01

    Full Text Available The family of epidermal growth factor (EGF, EGFR, c-erbB-2 plays a pivotal role in gastric cancer progression, invasion and metastasizing. Helicobacter pylori infection is known to contribute significantly to the formation and progression of gastric cancer. However, the mechanisms responsible for this process have not been yet elucidated. We analysed the relationship between H. pylori infection and expression of proteins belonging to the family of epidermal growth factor (EGF, EGFR, c-erbB-2. Fifty-five patients with gastric cancer were analysed for Helicobacter pylori infection. The expressions of EGF, EGFR, c-erbB-2 proteins were determined using an immunohistochemical method. No statistically significant correlation was found between the degree of H. pylori infection and the expressions of EGF, EGFR and c-erbB-2 in gastric cancer. However, c-erbB-2 expression in the main mass of tumour correlated with tumour expression of EGF and EGFR and with c-erbB-2 expression in local lymph nodes. The expression of c-erbB-2 in lymph nodes was statistically significantly related to the expressions of EGF and EGFR both in the main mass of tumour and in lymph nodes. The expression of EGF was found to correlate with EGFR in the main mass of tumour and the expression of EGF in lymph nodes was related to lymph node EGFR level. Our study did not confirm the relationship between H. pylori infection and the expression of epidermal growth factor in gastric cancer.

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

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

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

    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

  9. Temporal changes of EGFR mutations and T790M levels in tumour and plasma DNA following AZD9291 treatment.

    Chia, Puey Ling; Do, Hongdo; Morey, Adrienne; Mitchell, Paul; Dobrovic, Alexander; John, Thomas

    2016-08-01

    AZD9291, a T790M specific epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI), has demonstrated impressive response rates in tumours harbouring the EGFR T790M resistance mutation. Emergence of resistance to AZD9291 has been shown to occur through several different mechanisms including the development of new mutations (e.g. C797S) in the EGFR tyrosine kinase domain. We studied two patients with paired tumour biopsies and blood samples pre- and post-progression on AZD9291 to explore possible resistance mechanisms. Pre- and Post-AZD9291 tumour biopsies as well as serial plasma samples were collected from two patients on the AURA clinical study (AZD9291 First Time in Patients Ascending Dose study). Droplet digital PCR (ddPCR) assays were used to quantify T790M, the driver EGFR mutation, and the C797S mutation in genomic DNA from paired tumour biopsies and plasma cell-free DNA. In the first patient, both EGFR T790M and L858R became undetectable in the plasma within 1 month after treatment with AZD9291. However, the T790M and the original L858R mutation re-emerged with radiologically confirmed resistance to AZD9291. In patient two, the levels of T790M were undetectable at the time of radiological resistance to AZD9291 but increasing levels of the original EGFR exon 19 deletion was detected. MET amplification was detected in a biopsy performed on progression. The EGFR C797S mutation was not detected in either patient at the time of relapse. ddPCR of cell free DNA enables real time monitoring of patients on 3rd generation TKIs. As resistance mechanisms are variable, monitoring levels of the initial activating EGFR mutation may facilitate more reliable detection of progression. PMID:27393503

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

    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.

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

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

    2012-11-01

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

  12. Management of hyperglycemia from epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) targeting T790M-mediated resistance.

    Villadolid, Jeryl; Ersek, Jennifer L; Fong, Mei Ka; Sirianno, Lindsey; Story, Ellen S

    2015-10-01

    Epidermal growth factor receptor (EGFR) mutations in non-small cell lung cancer (NSCLC) patients are associated with sensitivity to small molecule tyrosine kinase inhibitors (TKIs) such as erlotinib, gefitinib, and afatinib. Although studies show an increased progression free survival (PFS) with use of EGFR TKIs in the first-line setting, most patients will develop resistance to therapy after the first 8-16 months. T790M is an acquired resistance mutation reported in 60-70% of patients who initially responded to a prior EGFR TKI. Recently, EGFR TKIs targeting T790M have been developed to overcome resistance with positive results in PFS and objective response rate in patients who have had disease progression on at least one TKI. Two EGFR TKIs targeting T790M, AZD9291 and rociletinib, are new active treatment options for NSCLC but differ in adverse effect profiles. Dose-limiting hyperglycemia has been reported with rociletinib and has required dose reduction, an oral antihyperglycemic, or both, without discontinuation of therapy. This suggests that patients may be effectively treated chronically for hyperglycemia associated with EGFR TKIs targeting T790M, however, guidelines for treatment of hyperglycemia in this setting have not been published. We discuss mechanisms of hyperglycemia associated with TKIs and initial management of hyperglycemia, including benefits and limitations of oral antihyperglycemic options, adjustment of therapy based on grade of hyperglycemia, and recommendations for follow-up glucose monitoring. PMID:26629426

  13. Assessment of early changes in 3H-fluorothymidine uptake after treatment with gefitinib in human tumor xenograft in comparison with Ki-67 and phospho-EGFR expression

    The purpose of this study was to evaluate whether early changes in 3′-deoxy-3′-3H-fluorothymidine (3H-FLT) uptake can reflect the antiproliferative effect of gefitinib in a human tumor xenograft, in comparison with the histopathological markers, Ki-67 and phosphorylated EGFR (phospho-EGFR). An EGFR-dependent human tumor xenograft model (A431) was established in female BALB/c athymic mice, which were divided into three groups: one control group and two treatment groups. Mice in the treatment groups were orally administered a partial regression dose (100 mg/kg/day) or the maximum tolerated dose of gefitinib (200 mg/kg/day), once daily for 2 days. Mice in the control group were administered the vehicle (0.1% Tween 80). Tumor size was measured before and 3 days after the start of treatment. Biodistribution of 3H-FLT and 18F-FDG (%ID/g/kg) was examined 3 days after the start of the treatment. Tumor cell proliferative activity with Ki-67 was determined. Immunohistochemical staining of EGFR and measurement of phospho-EGFR were also performed. High expression levels of EGFR and Ki-67 were observed in the A431 tumor. After the treatment with 100 and 200 mg/kg gefitinib, the uptake levels of 3H-FLT in the tumor were significantly reduced to 67% and 61% of the control value, respectively (0.39 ± 0.09, 0.36 ± 0.06, 0.59 ± 0.11%ID/g/kg for 100 mg/kg, 200 mg/kg, and control groups, respectively; p < 0.01 vs. control), but those of 18F-FDG were not. After the treatment with 100 and 200 mg/kg gefitinib, the expression levels of Ki-67 in the tumor were markedly decreased (4.6 ± 2.4%, 6.2 ± 1.8%, and 10.4 ± 5.7% for 100 mg/kg, 200 mg/kg, and control groups, respectively, p < 0.01 vs. control). The expression levels of the phospho-EGFR protein also significantly decreased (29% and 21% of the control value for 100, and 200 mg/kg, respectively p < 0.01 vs. control). There was no statistically significant difference in tumor size between pre- and post-treatments in each group

  14. AZD9291 in TKI EGFR resistance in non-small cell lung cancer and the new concept of phase I trials.

    Gil-Bazo, Ignacio; Rolfo, Christian

    2016-02-01

    Epidermal growth factor receptor (EGFR) tyrosine-kinase inhibitors (TKIs) constitute the standard of care for stage IV EGFR mutated non-small cell lung cancer (NSCLC) patients initiating first-line systemic treatment. Despite the initial remarkable activity of targeted treatment in these patients rendering objective response rates (ORR) of 50-80% and progression-free survivals (PFS) of 9-12 months, most patients present disease progression during the first 12 to 24 months. Although the activity of platinum-based doublets has been shown in EGFR mutated NSCLC patients after progression to first-line TKIs, PFS is rather short. Drug development companies have more recently focused their attention on the molecular basis of EGFR TKIs acquired resistance. Secondary resistance mutations have proven to be the most frequent cause of acquired resistance. Among them, T790M mutation in exon 20 seems to be the leading responsible for that resistance. Several agents have shown preliminary preclinical and clinical activity in overcoming acquired resistance to firstline EGFR TKIs. To date, however, only AZD9291, an oral, potent, irreversible EGFR TKI that is selective for EGFR tyrosine kinase inhibitor-sensitizing mutations and the T790M resistance mutation has shown to be not only highly active but also fairly tolerable in a large cohort of patients. Here we present a critical analysis of this trial in its clinical setting and propose some future directions. PMID:26958497

  15. Targeting EGFR and COX-2 as a potential treatment improvement strategy in cancer radiotherapy

    Molecular targeting, i.e. use of agents that counteract molecular processes that are dysregulated in cancer cells, which may be responsible for tumor radio-or chemoresistance, is a recently extensively investigated approach to further improve radiotherapy, chemotherapy or radiochemotherapy. Many potential targets for augmentation of radio (or chemo) response have been identified including epidermal growth factor receptor (EGFR), cyclooxygenase-2 (COX-2) enzyme, mutated ras and angiogenic molecules. Agents that selectively inhibit these molecules are becoming available at a rapid rate, and many of them have been shown in preclinical testing to be highly effective in improving tumor radioresponse or chemoresponse, without significantly affecting normal tissues. The interaction of EGFR and COX-2 inhibitors with radiation has attracted a flare of investigational interest, and is over-viewed here. EGFR is frequently overexpressed or mutated in many types of cancer, which is associated with more aggressive tumor behavior and poorer tumor response to cytotoxic agents, including radiation. Blockade of EGFR or interference with its downstream signaling processes can improve tumor treatment. Our own studies, using human tumor xenografts, demonstrated that blocking EGFR with C225 anti-EGFR antibody produces a dramatic enhancement of tumor radioresponse, and even more dramatic response when radiation is combined with chemotherapeutic agents. C225 acts by a number of mechanisms including inhibition of DNA repair from radiation damage, enhancement of apoptosis and tumor necrosis, and by inhibition of tumor angiogenesis. Inhibition of tyrosine kinase activation by small molecule agents, such as Iressa or Tarceva, is another approach in interfering with EGFR-signaling, which also showed potent enhancing effect on tumor radioresponse. There are two COX enzymes: COX-1 and COX-2. While COX-1 is a ubiquitous constitutive enzyme having housekeeping physiological function, COX-2 is an

  16. The prognostic values of EGFR expression and KRAS mutation in patients with synchronous or metachronous metastatic colorectal cancer

    The epidermal growth factor receptor (EGFR)/RAS/RAF/MEK/MAPK pathway is an important pathway in the carcinogenesis, invasion and metastasis of colorectal cancers (CRCs). We conducted a retrospective study to determine the prognostic values of EGFR expression and KRAS mutation in patients with metastatic CRC (mCRC) based on synchronous or metachronous status. From October 2002 to March 2012, 205 patients with mCRC were retrospectively analyzed; 98 were found to have metachronous mCRC while 107 were found to have synchronous mCRC. The EGFR expressions were determinate by IHC (immunohistochemistry) analysis and categorized 1+ (weak intensity), 2+ (moderate intensity), and 3+ (strong intensity). Genomic DNA was isolated from frozen primary CRC tissues and direct sequencing of KRAS was performed. The clinicopathological features of these mCRC patients were retrospectively investigated according to EGFR expression and KRAS mutation status. Moreover, we analyzed the prognostic values of EGFR expression and KRAS mutation among these patients. Of the 205 patients with mCRC, EGFR expression was analyzed in 167 patients, and positive EGFR expression was noted in 140 of those patients (83.8%). KRAS mutation was investigated in 205 patients and mutations were noted in 88 of those patients (42.9%). In patients with metachronous mCRC, positive EGFR expression was significantly correlated with well-and moderately-differentiated tumors (P = 0.028), poorer disease-free survival (DFS) (P < 0.001), and overall survival (OS) (P < 0.001). Furthermore, positive EGFR expression was a significant independent prognostic factor of DFS (P = 0.006, HR: 4.012, 95% CI: 1.130–8.445) and OS (P = 0.028, HR: 3.090, 95% CI: 1.477–10.900) in metachronous mCRC patients. KRAS mutation status was not significantly related to DFS and OS of patients with metachronous mCRC; likewise, KRAS mutation status was not significantly different in the progression-free survival (PFS) and OS of patients with

  17. Management of egfr tki–induced dermatologic adverse events

    Melosky, B.; Leighl, N.B.; Rothenstein, J; Sangha, R.; Stewart, D; Papp, K.

    2015-01-01

    Targeting the epidermal growth factor receptor (egfr) pathway has become standard practice for the treatment of advanced non-small-cell lung cancer. Compared with chemotherapy, egfr tyrosine kinase inhibitors (tkis) have been associated with improved efficacy in patients with an EGFR mutation. Together with the increase in efficacy comes an adverse event (ae) profile different from that of chemotherapy. That profile includes three of the most commonly occurring dermatologic aes: acneiform ras...

  18. Nuclear EGFR Contributes to Acquired Resistance to Cetuximab

    Li, Chunrong; Iida, Mari; Dunn, Emily F.; Ghia, Amol J.; Wheeler, Deric L

    2009-01-01

    Epidermal growth factor receptor (EGFR) is a ubiquitously expressed receptor tyrosine kinase involved in the etiology of several human cancers. Cetuximab is an EGFR blocking-antibody that has been approved for the treatment of patients with cancers of the head and neck (HNSCC) and metastatic colorectal cancer (mCRC). Previous reports have shown that EGFR translocation to the nucleus is associated with cell proliferation. Here we investigated mechanisms of acquired resistance to cetuximab usin...

  19. A Novel Technique to Detect EGFR Mutations in Lung Cancer

    Yuanbin Liu; Ting Lei; Zhiyu Liu; Yanbin Kuang; Jianxin Lyu; Qi Wang

    2016-01-01

    Epidermal growth factor receptor (EGFR) gene mutations occur in multiple human cancers; therefore, the detection of EGFR mutations could lead to early cancer diagnosis. This study describes a novel EGFR mutation detection technique. Compared to direct DNA sequencing detection methods, this method is based on allele-specific amplification (ASA), recombinase polymerase amplification (RPA), peptide nucleic acid (PNA), and SYBR Green I (SYBR), referred to as the AS-RPA-PNA-SYBR (ARPS) system. The...

  20. Discovery of AZD8931, an Equipotent, Reversible Inhibitor of Signaling by EGFR, HER2, and HER3 Receptors.

    Barlaam, Bernard; Anderton, Judith; Ballard, Peter; Bradbury, Robert H; Hennequin, Laurent F A; Hickinson, D Mark; Kettle, Jason G; Kirk, George; Klinowska, Teresa; Lambert-van der Brempt, Christine; Trigwell, Cath; Vincent, John; Ogilvie, Donald

    2013-08-01

    Deregulation of HER family signaling promotes proliferation and tumor cell survival and has been described in many human cancers. Simultaneous, equipotent inhibition of EGFR-, HER2-, and HER3-mediated signaling may be of clinical utility in cancer settings where the selective EGFR or HER2 therapeutic agents are ineffective or only modestly active. We describe the discovery of AZD8931 (2), an equipotent, reversible inhibitor of EGFR-, HER2-, and HER3-mediated signaling and the structure-activity relationships within this series. Docking studies based on a model of the HER2 kinase domain helped rationalize the increased HER2 activity seen with the methyl acetamide side chain present in AZD8931. AZD8931 exhibited good pharmacokinetics in preclinical species and showed superior activity in the LoVo tumor growth efficacy model compared to close analogues. AZD8931 is currently being evaluated in human clinical trials for the treatment of cancer. PMID:24900741

  1. 15 CFR 930.35 - Negative determinations for proposed activities.

    2010-01-01

    ... periodically assess whether the general negative determination is still applicable. (e) In the event of a... 15 Commerce and Foreign Trade 3 2010-01-01 2010-01-01 false Negative determinations for proposed... Federal Agency Activities § 930.35 Negative determinations for proposed activities. (a) If a...

  2. Nuclear FABP7 immunoreactivity is preferentially expressed in infiltrative glioma and is associated with poor prognosis in EGFR-overexpressing glioblastoma

    Aldape Ken D

    2006-04-01

    Full Text Available Abstract Background We previously identified brain type fatty acid-binding protein (FABP7 as a prognostic marker for patients with glioblastoma (GBM. Increased expression of FABP7 is associated with reduced survival. To investigate possible molecular mechanisms underlying this association, we compared the expression and subcellular localization of FABP7 in non-tumor brain tissues with different types of glioma, and examined the expression of FABP7 and epidermal growth factor receptor (EGFR in GBM tumors. Methods Expression of FABP7 in non-tumor brain and glioma specimens was examined using immunohistochemistry, and its correlation to the clinical behavior of the tumors was analyzed. We also analyzed the association between FABP7 and EGFR expression in different sets of GBM specimens using published DNA microarray datasets and semi-quantitative immunohistochemistry. In vitro migration was examined using SF763 glioma cell line. Results FABP7 was present in a unique population of glia in normal human brain, and its expression was increased in a subset of reactive astrocytes. FABP7 immunoreactivity in grade I pilocytic astrocytoma was predominantly cytoplasmic, whereas nuclear FABP7 was detected in other types of infiltrative glioma. Nuclear, not cytoplasmic, FABP7 immunoreactivity was associated with EGFR overexpression in GBM (N = 61, p = 0.008. Expression of the FABP7 gene in GBM also correlated with the abundance of EGFR mRNA in our previous microarray analyses (N = 34, p = 0.016 and an independent public microarray dataset (N = 28, p = 0.03. Compared to those negative for both markers, nuclear FABP7-positive/EGFR-positive and nuclear FABP7-positive/EGFR-negative GBM tumors demonstrated shortest survival, whereas those only positive for EGFR had intermediate survival. EGFR activation increased nuclear FABP7 immunoreactivity in a glioma cell line in vitro, and inhibition of FABP7 expression suppressed EGF-induced glioma-cell migration. Our data

  3. Nuclear FABP7 immunoreactivity is preferentially expressed in infiltrative glioma and is associated with poor prognosis in EGFR-overexpressing glioblastoma

    We previously identified brain type fatty acid-binding protein (FABP7) as a prognostic marker for patients with glioblastoma (GBM). Increased expression of FABP7 is associated with reduced survival. To investigate possible molecular mechanisms underlying this association, we compared the expression and subcellular localization of FABP7 in non-tumor brain tissues with different types of glioma, and examined the expression of FABP7 and epidermal growth factor receptor (EGFR) in GBM tumors. Expression of FABP7 in non-tumor brain and glioma specimens was examined using immunohistochemistry, and its correlation to the clinical behavior of the tumors was analyzed. We also analyzed the association between FABP7 and EGFR expression in different sets of GBM specimens using published DNA microarray datasets and semi-quantitative immunohistochemistry. In vitro migration was examined using SF763 glioma cell line. FABP7 was present in a unique population of glia in normal human brain, and its expression was increased in a subset of reactive astrocytes. FABP7 immunoreactivity in grade I pilocytic astrocytoma was predominantly cytoplasmic, whereas nuclear FABP7 was detected in other types of infiltrative glioma. Nuclear, not cytoplasmic, FABP7 immunoreactivity was associated with EGFR overexpression in GBM (N = 61, p = 0.008). Expression of the FABP7 gene in GBM also correlated with the abundance of EGFR mRNA in our previous microarray analyses (N = 34, p = 0.016) and an independent public microarray dataset (N = 28, p = 0.03). Compared to those negative for both markers, nuclear FABP7-positive/EGFR-positive and nuclear FABP7-positive/EGFR-negative GBM tumors demonstrated shortest survival, whereas those only positive for EGFR had intermediate survival. EGFR activation increased nuclear FABP7 immunoreactivity in a glioma cell line in vitro, and inhibition of FABP7 expression suppressed EGF-induced glioma-cell migration. Our data suggested that in EGFR-positive GBM the presence of

  4. Platycodin D inhibits migration, invasion, and growth of MDA-MB-231 human breast cancer cells via suppression of EGFR-mediated Akt and MAPK pathways.

    Chun, Jaemoo; Kim, Yeong Shik

    2013-10-01

    Platycodin D (PD), an active triterpenoid saponin from Platycodon grandiflorum, has been known to inhibit the proliferation of a variety of cancer cells, but the effect of PD on the invasiveness of cancer cells is largely unknown. In this study, we first determined the molecular mechanism by which PD inhibits the migratory and invasive abilities of the highly metastatic MDA-MB-231 breast cancer cell line. We demonstrated that a non-cytotoxic concentration of PD markedly suppressed wound healing migration, invasion through the matrigel, and adhesion to an ECM-coated substrate in a dose-dependent manner. Moreover, PD inhibited cell invasion by reducing matrix metalloproteinase (MMP)-9 enzyme activity and mRNA expression. Western blot analysis indicated that PD potently suppressed the phosphorylation of extracellular signal-regulated kinase (ERK), p38, and c-Jun N-terminal kinase (JNK) as well as blocked the phosphatidylinositol-3-kinase (PI3K)/Akt/mTOR signaling pathway. Furthermore, PD treatment inhibited the DNA binding activity of NF-κB, which is known to mediate the expression of epidermal growth factor receptor (EGFR), as observed by electrophoretic mobility shift assay. Specific mechanisms of action exerted by PD involved the downregulation of EGFR and the inhibition of EGF-induced activation of the EGFR, MAPK, and PI3K/Akt pathways. The in vivo studies showed that PD significantly inhibited the growth of MDA-MB-231 xenograft tumors in BALB/c nude mice. These results suggest that PD might be a potential therapeutic candidate for the treatment of breast cancer metastasis. PMID:23867902

  5. Protein determination in seeds by proton activation

    Morales, J. R.; Dinator, M. I.; Cerda, P.

    1989-04-01

    A proton beam of 6.6 MeV has been used to produce 11C and 13N in Araucaria Araucana seeds. Their positron decay allows determination of the N/C ratio. In seeds the nitrogen content is associated to proteins while carbon is spread in the organic material. Samples were irradiated for about 10 min with a beam intensity of 5 nA on areas of 1 mm 2. Slices of the seed were radially explored, showing a larger concentration of protein in the center.

  6. Protein determination in seeds by proton activation

    Morales, J.R.; Dinator, M.I. (Chile Univ., Santiago (Chile). Lab. de Fisica); Cerda, P. (Bio-Bio Univ., Chillan (Chile))

    1989-04-01

    A proton beam of 6.6 MeV has been used to produce /sup 11/C and /sup 13/N in Araucaria Araucana seeds. Their positron decay allows determination of the N/C ratio. In seeds the nitrogen content is associated to proteins while carbon is spread in the organic material. Samples were irradiated for about 10 min with a beam intensity of 5 nA on areas of 1 mm/sup 2/. Slices of the seed were radially explored, showing a larger concentration of protein in the center. (orig.).

  7. Cross-talk between AMPK and EGFR dependent Signaling in Non-Small Cell Lung Cancer

    Praveen, Paurush; Hülsmann, Helen; Sültmann, Holger; Kuner, Ruprecht; Fröhlich, Holger

    2016-06-01

    Lung cancers globally account for 12% of new cancer cases, 85% of these being Non Small Cell Lung Cancer (NSCLC). Therapies like erlotinib target the key player EGFR, which is mutated in about 10% of lung adenocarcinoma. However, drug insensitivity and resistance caused by second mutations in the EGFR or aberrant bypass signaling have evolved as a major challenge in controlling these tumors. Recently, AMPK activation was proposed to sensitize NSCLC cells against erlotinib treatment. However, the underlying mechanism is largely unknown. In this work we aim to unravel the interplay between 20 proteins that were previously associated with EGFR signaling and erlotinib drug sensitivity. The inferred network shows a high level of agreement with protein-protein interactions reported in STRING and HIPPIE databases. It is further experimentally validated with protein measurements. Moreover, predictions derived from our network model fairly agree with somatic mutations and gene expression data from primary lung adenocarcinoma. Altogether our results support the role of AMPK in EGFR signaling and drug sensitivity.

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

    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.

  9. The challenge of targeting EGFR: experience with gefitinib in nonsmall cell lung cancer

    C.L. Watkins

    2010-09-01

    Full Text Available As the first approved epidermal growth factor receptor (EGFR-targeted therapy for nonsmall cell lung cancer (NSCLC, the clinical development of gefitinib was complex. Advances in scientific understanding of the target biology during its clinical development enabled the identification of a biomarker to define patients most likely to derive benefit from gefitinib. Initial phase II trials showed clinically meaningful anti-tumour activity in 12–18% of unselected pretreated patients with advanced NSCLC at the optimum biological dose (250 mg. Subgroup analyses of these and subsequent phase III trials in unselected patients suggested that EGFR mutation and some clinical characteristics associated with a higher incidence of EGFR mutation (Asian ethnicity, adenocarcinoma histology, never-smoking and female sex were linked with increased response to gefitinib. Consequently, the IRESSA Pan-Asia Study (IPASS was conducted in never-smokers or former light-smokers in East Asia who had adenocarcinoma of the lung. IPASS showed that EGFR mutation was the strongest predictor of improved progression-free survival (mutation-positive subgroup hazard ratio (HR 0.48, 95% CI 0.36–0.64 (p<0.001, n = 261; mutation-negative subgroup HR 2.85, 95% CI 2.05–3.98 (p<0.001, n = 176; interaction test p<0.001 with gefitinib versus carboplatin/paclitaxel as first-line therapy for advanced NSCLC. Important lessons for the development of future personalised medicines are discussed.

  10. Device for determining carbon activity through pressure

    A hollow iron capsule of annular shape having an interior layer of Fe0.947O and a near absolute internal vacuum is submersed within a molten metal with the inner chamber of the capsule connected to a pressure sensor. Carbon present in the molten metal diffuses through the capsule wall and reacts with the Fe0.947O layer to generate a CO2--CO gas mixture within the internal chamber. The total absolute pressure of the gas measured by the pressure sensor is directly proportional to the carbon activity of the molten metal

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

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

  12. [Research Progress of EGFR-TKI Therapy for Patients with Central Nervous System 
Metastases from Non-small Cell Lung Cancer].

    Jin, Yinghua; Xin, Tao

    2016-08-20

    Approximately half of all patients with non-small cell lung cancer (NSCLC) develop central nervous system metastases during the course of their disease which indicate poor prognosis. A part of NSCLC patients demonstrates activating epidermal growth factor receptor gene (EGFR) mutations who represent effectiveness and well tolerance of EGFR-specific tyrosine kinase inhibitors (TKIs) therapy. Although the systemic efficacy of targeted agents is established, the efficacy of central nervous system (CNS) metastases is not as well characterized. In this article, we review recent data on the use of EGFR inhibitors for treatment of patients with NSCLC and CNS metastases. PMID:27561797

  13. Controlled physical activity for functional operability determination

    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.

  14. Flagellin-induced corneal antimicrobial peptide production and wound repair involve a novel NF-kappaB-independent and EGFR-dependent pathway.

    Nan Gao

    Full Text Available BACKGROUND: The bacterial protein flagellin plays a major role in stimulating mucosal surface innate immune response to bacterial infection and uniquely induces profound cytoprotection against pathogens, chemicals, and radiation. This study sought to determine signaling pathways responsible for the flagellin-induced inflammatory and cytoprotective effects on human corneal epithelial cells (HCECs. METHODOLOGY/PRINCIPAL FINDINGS: Flagellin purified from Pseudomonas aeruginosa (strain PAK or live bacteria were used to challenge cultured HCECs. The activation of signaling pathways was assessed with Western blot, and the secretion of cytokine/chemokine and production of antimicrobial peptides (AMPs were measured with ELISA and dot blot, respectively. Effects of flagellin on wound healing were assessed in cultured porcine corneas. L94A (a site mutation in TLR5 binding region flagellin and PAK expressing L94A flagellin were unable to stimulate NF-kappaB activation, but were potent in eliciting EGFR signaling in a TGF-alpha-related pathway in HCECs. Concomitant with the lack of NF-kappaB activation, L94A flagellin was ineffective in inducing IL-6 and IL-8 production in HCECs. Surprisingly, the secretion of two inducible AMPs, LL-37 and hBD2, was not affected by L94A mutation. Similar to wild-type flagellin, L94A induced epithelial wound closure in cultured porcine cornea through maintaining EGFR-mediated signaling. CONCLUSIONS/SIGNIFICANCE: Our data suggest that inflammatory response mediated by NF-kappaB can be uncoupled from epithelial innate defense machinery (i.e., AMP expression and major epithelial proliferation/repair pathways mediated by EGFR, and that flagellin and its derivatives may have broad therapeutic applications in cytoprotection and in controlling infection in the cornea and other mucosal tissues.

  15. EGFR kinase promotes acquisition of stem cell-like properties: a potential therapeutic target in head and neck squamous cell carcinoma stem cells.

    Eric L Abhold

    Full Text Available Members of the EGFR/ErbB family of tyrosine kinases are found to be highly expressed and deregulated in many cancers, including head and neck squamous cell carcinoma (HNSCC. The ErbB family, including EGFR, has been demonstrated to play key roles in metastasis, tumorigenesis, cell proliferation, and drug resistance. Recently, these characteristics have been linked to a small subpopulation of cells classified as cancer stem cells (CSCs which are believed to be responsible for tumor initiation and maintenance. In this study, we investigated the possible role of EGFR as a regulator of "stemness" in HNSCC cells. Activation of EGFR by the addition of EGF ligand or ectopic expression of EGFR in two established HNSCC cell lines (UMSCC-22B and HN-1 resulted in the induction of CD44, BMI-1, Oct-4, NANOG, CXCR4, and SDF-1. Activation of EGFR also resulted in increased tumorsphere formation, a characteristic ability of cancer stem cells. Conversely, treatment with the EGFR kinase inhibitor, Gefinitib (Iressa, resulted in decreased expression of the aforementioned genes, and loss of tumorsphere-forming ability. Similar trends were observed in a 99.9% CD44 positive stem cell culture derived from a fresh HNSCC tumor, confirming our findings for the cell lines. Additionally, we found that these putative cancer stem cells, when treated with Gefitinib, possessed a lower capacity to invade and became more sensitive to cisplatin-induced death in vitro. These results suggest that EGFR plays critical roles in the survival, maintenance, and function of cancer stem cells. Drugs that target EGFR, perhaps administered in combination with conventional chemotherapy, might be an effective treatment for HNSCC.

  16. High efficacy of third generation EGFR inhibitor AZD9291 in a leptomeningeal carcinomatosis model with EGFR-mutant lung cancer cells

    Nanjo, Shigeki; Ebi, Hiromichi; Arai, Sachiko; Takeuchi, Shinji; Yamada, Tadaaki; Mochizuki, Satsuki; Okada, Yasunori; Nakada, Mitsutoshi; Murakami, Takashi; Yano, Seiji

    2015-01-01

    Leptomeningeal carcinomatosis (LMC) remarkably decreases the quality of life of EGFR-mutant lung cancer patients. In contrast to the lesions outside the central nervous system (CNS), molecular mechanisms of EGFR tyrosine kinase inhibitor (TKI) resistance in CNS lesions including LMC are largely unknown. In this study, we established an in vivo imaging model for LMC with EGFR mutant lung cancer cell lines harboring an exon 19 deletion in EGFR and evaluated the effect of first generation EGFR-T...

  17. The human epidermal growth factor receptor (EGFR gene in European patients with advanced colorectal cancer harbors infrequent mutations in its tyrosine kinase domain

    Delvenne Philippe

    2011-10-01

    Full Text Available Abstract Background The epidermal growth factor receptor (EGFR, a member of the ErbB family of receptors, is a transmembrane tyrosine kinase (TK activated by the binding of extracellular ligands of the EGF-family and involved in triggering the MAPK signaling pathway, which leads to cell proliferation. Mutations in the EGFR tyrosine kinase domain are frequent in non-small-cell lung cancer (NSCLC. However, to date, only very few, mainly non-European, studies have reported rare EGFR mutations in colorectal cancer (CRC. Methods We screened 236 clinical tumor samples from European patients with advanced CRC by direct DNA sequencing to detect potential, as yet unknown mutations, in the EGFR gene exons 18 to 21, mainly covering the EGFR TK catalytic domain. Results EGFR sequences showed somatic missense mutations in exons 18 and 20 at a frequency of 2.1% and 0.4% respectively. Somatic SNPs were also found in exons 20 and 21 at a frequency of about 3.1% and 0.4% respectively. Of these mutations, four have not yet been described elsewhere. Conclusions These mutation frequencies are higher than in a similarly sized population characterized by Barber and colleagues, but still too low to account for a major role played by the EGFR gene in CRC.

  18. Dual-targeting organometallic ruthenium(II) anticancer complexes bearing EGFR-inhibiting 4-anilinoquinazoline ligands.

    Zhang, Yang; Zheng, Wei; Luo, Qun; Zhao, Yao; Zhang, Erlong; Liu, Suyan; Wang, Fuyi

    2015-08-01

    We have recently demonstrated that complexation with (η(6)-arene)Ru(II) fragments confers 4-anilinoquinazoline pharmacophores a higher potential for inducing cellular apoptosis while preserving the highly inhibitory activity of 4-anilinoquinazolines against EGFR and the reactivity of the ruthenium centre to 9-ethylguanine (Chem. Commun., 2013, 49, 10224-10226). Reported herein are the synthesis, characterisation and evaluation of the biological activity of a new series of ruthenium(ii) complexes of the type [(η(6)-arene)Ru(N,N-L)Cl]PF6 (arene = p-cymene, benzene, 2-phenylethanol or indane, L = 4-anilinoquinazolines). These organometallic ruthenium complexes undergo fast hydrolysis in aqueous solution. Intriguingly, the ligation of (arene)Ru(II) fragments with 4-anilinoquinazolines not only makes the target complexes excellent EGFR inhibitors, but also confers the complexes high affinity to bind to DNA minor grooves while maintaining their reactivity towards DNA bases, characterising them with dual-targeting properties. Molecular modelling studies reveal that the hydrolysis of these complexes is a favourable process which increases the affinity of the target complexes to bind to EGFR and DNA. In vitro biological activity assays show that most of this group of ruthenium complexes are selectively active inhibiting the EGF-stimulated growth of the HeLa cervical cancer cell line, and the most active complex [(η(6)-arene)Ru(N,N-L13)Cl]PF6 (, IC50 = 1.36 μM, = 4-(3'-chloro-4'-fluoroanilino)-6-(2-(2-aminoethyl)aminoethoxy)-7-methoxyquinazoline) is 29-fold more active than its analogue, [(η(6)-arene)Ru(N,N-ethylenediamine)Cl]PF6, and 21-fold more active than gefitinib, a well-known EGFR inhibitor in use clinically. These results highlight the strong promise to develop highly active ruthenium anticancer complexes by ligation of cytotoxic ruthenium pharmacophores with bioactive organic molecules. PMID:26106875

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

    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

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

    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.

  1. Detecting and treating breast cancer resistance to EGFR inhibitors

    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.

  2. Effects of the EGFR Inhibitor Erlotinib on Magnesium Handling

    Dimke, Henrik Anthony; van der Wijst, Jenny; Alexander, Todd R;

    2010-01-01

    A mutation in pro-EGF causes isolated hypomagnesemia, and monoclonal antibodies targeting the extracellular domain of the EGF receptor (EGFR) affect epithelial Mg(2+) transport. The effect of the EGFR tyrosine kinase inhibitor erlotinib on Mg(2+) homeostasis, however, remains unknown. Here, we in...

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

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

  4. Structural and institutional determinants of investment activity in Africa

    Chuku, Chuku; Onye, Kenneth; Ajah, Hycent

    2015-01-01

    This paper considers the structural and institutional determinants of investment activity in selected African countries within a neoclassical framework. Generalized method of moments and a family of panel data estimation techniques are utilized in addition to nonparametric kernel regression techniques to uncover the relationship. Three main findings emerge; (i) financial openness and institutional quality are reasonably robust structural and institutional determinants of investment activity...

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

    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

  6. EGFR and microvessel density in canine malignant mammary tumours.

    Carvalho, Maria Isabel; Guimarães, Maria João; Pires, Isabel; Prada, Justina; Silva-Carvalho, Ricardo; Lopes, Carlos; Queiroga, Felisbina L

    2013-12-01

    The epidermal growth factor receptor (EGFR) is a transmembrane tyrosine kinase receptor which has been shown to have an important role in human breast cancer. Its role appears to be associated with increased angiogenesis and metastasis. In order to clarify its role in canine mammary tumours (CMT), 61 malignant neoplasms were studied by using immunohistochemistry, comparing expression of EGFR, microvessel density (MVD) by CD31 immunolabelling and characteristics of tumour aggressiveness. High EGFR immunoexpression was statistically significantly associated with tumour size, tumour necrosis, mitotic grade, histological grade of malignancy and clinical stage. High CD31 immunoreactivity was statistically significantly associated with tubule formation, histological grade of malignancy and clinical stage. A positive correlation between EGFR and CD31 immunoexpression (r = 0.843; P aggression in malignant CMT, presenting the possibility of using EGFR inhibitors in the context of metastatic disease treatment. PMID:24091029

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

    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: http://www.clinicaltrials.gov/ct2/show/NCT00815971

  8. Mathematical method for pig iron specific activity determination

    An original method for pig iron specific activity determination is presented. The mathematical method described is based on the Monte Carlo procedure and is referred to two practical stiuations determined by whether the nature of radionuclide contaminating the pig iron is known or not. Two methods for pig iron specific activity determination, a global and a spectrometric one, are presented, each of them being used in one of the practical situations mentioned above. (author)

  9. Determinants of Change in Physical Activity in Children and Adolescents

    Craggs, Christopher; Corder, Kirsten; van Sluijs, Esther M. F.; Simon J Griffin

    2011-01-01

    Context Data are available on correlates of physical activity in children and adolescents, less is known about the determinants of change. This review aims to systematically review the published evidence regarding determinants of change in physical activity in children and adolescents. Evidence acquisition Prospective quantitative studies investigating change in physical activity in children and adolescents aged 4–18 years were identified from seven databases (to November 2010): PubMed, SCOPU...

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

    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. PMID:26650936

  11. AZD9291 in TKI EGFR resistance in non-small cell lung cancer and the new concept of phase I trials

    Gil-Bazo, Ignacio; Rolfo, Christian

    2016-01-01

    Epidermal growth factor receptor (EGFR) tyrosine-kinase inhibitors (TKIs) constitute the standard of care for stage IV EGFR mutated non-small cell lung cancer (NSCLC) patients initiating first-line systemic treatment. Despite the initial remarkable activity of targeted treatment in these patients rendering objective response rates (ORR) of 50–80% and progression-free survivals (PFS) of 9–12 months, most patients present disease progression during the first 12 to 24 months. Although the activi...

  12. PET of EGFR with (64) Cu-cetuximab-F(ab')2 in mice with head and neck squamous cell carcinoma xenografts.

    van Dijk, Laura K; Yim, Cheng-Bin; Franssen, Gerben M; Kaanders, Johannes H A M; Rajander, Johan; Solin, Olof; Grönroos, Tove J; Boerman, Otto C; Bussink, Johan

    2016-01-01

    Overexpression of the epidermal growth factor receptor (EGFR) is linked to an adverse outcome in various solid tumors. Cetuximab is an EGFR inhibitor, which in combination with radiotherapy improves locoregional control and survival in a subgroup of patients with head and neck squamous cell carcinomas (HNSCCs). The aim of this study was to develop and characterize an EGFR-directed PET tracer, (64) Cu-cetuximab-F(ab')2, to determine the systemic accessibility of EGFR. Mice with HNSCC xenografts, UT-SCC-8 (n = 6) or UT-SCC-45 (n = 6), were imaged 24 h post injection with (64) Cu-NODAGA-cetuximab-F(ab')2 using PET/CT. One mouse for each tumor model was co-injected with excess unlabeled cetuximab 3 days before radiotracer injection to determine non-EGFR-mediated uptake. Ex vivo biodistribution of the tracer was determined and tumors were analyzed by autoradiography and immunohistochemistry. The SUVmax of UT-SCC-8 tumors was higher than that of UT-SCC-45: 1.5 ± 1.0 and 0.8 ± 0.2 (p monitor the response to EGFR-inhibitor treatment. PMID:26242487

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

    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

  14. Chiral 6-aryl-furo[2,3-d]pyrimidin-4-amines as EGFR inhibitors.

    Han, Jin; Kaspersen, Svein Jacob; Nervik, Sondre; Nørsett, Kristin G; Sundby, Eirik; Hoff, Bård Helge

    2016-08-25

    Epidermal growth factor receptor inhibitors are of importance in cancer therapy and possibly in the management of pain. Herein, we report a structure-activity relationship study with 29 new 6-aryl-furo[2,3-d]pyrimidin-4-amines, involving modification of the 4-amino group and 6-aryl function. The EGFR activity was especially dependent on having a chiral 4-benzylamino group with correct stereochemistry. Molecular dynamics indicate this to be due to favourable cation-π interactions. The most active inhibitor identified, equipotent to Erlotinib, was substituted with (R)-1-phenylethylamine at C-4 and a N(1), N(1)-dimethyl-1,2-diamine group in para position of the 6-aryl moiety. These new furopyrimidines had a different off-target kinase profile when compared to Erlotinib, and also possessed high activity towards Ba/F3 EGFR(L858R) reporter cells. Further, comparing the EGFR data of the furo[2,3-d]pyrimidin-4-amines with that of the corresponding thieno- and pyrrolopyrimidines concludes the furopyrimidine scaffold to be highly useful for development of new epidermal growth factor receptor antagonists. PMID:27235841

  15. Impact of bevacizumab in combination with erlotinib on EGFR-mutated non-small cell lung cancer xenograft models with T790M mutation or MET amplification.

    Furugaki, Koh; Fukumura, Junko; Iwai, Toshiki; Yorozu, Keigo; Kurasawa, Mitsue; Yanagisawa, Mieko; Moriya, Yoichiro; Yamamoto, Kaname; Suda, Kenichi; Mizuuchi, Hiroshi; Mitsudomi, Tetsuya; Harada, Naoki

    2016-02-15

    Erlotinib (ERL), an epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor, shows notable efficacy against non-small cell lung cancer (NSCLC) harboring EGFR mutations. Bevacizumab (BEV), a humanized monoclonal antibody to vascular endothelial cell growth factor (VEGF), in combination with ERL (BEV+ERL) significantly extended progression-free survival in patients with EGFR-mutated NSCLC compared with ERL alone. However, the efficacy of BEV+ERL against EGFR-mutated NSCLC harboring T790M mutation or MET amplification, is unclear. Here, we examined the antitumor activity of BEV+ERL in four xenograft models of EGFR-mutated NSCLC (three harboring ERL resistance mutations). In the HCC827 models (exon 19 deletion: DEL), ERL significantly inhibited tumor growth by blocking EGFR signal transduction. Although there was no difference between ERL and BEV+ERL in maximum tumor growth inhibition, BEV+ERL significantly suppressed tumor regrowth during a drug-cessation period. In the HCC827-EPR model (DEL+T790M) and HCC827-vTR model (DEL+MET amplification), ERL reduced EGFR signal transduction and showed less pronounced but still significant tumor growth inhibition than in the HCC827 model. In these models, tumor growth inhibition was significantly stronger with BEV+ERL than with each single agent. In the NCI-H1975 model (L858R+T790M), ERL did not inhibit growth or EGFR signal transduction, and BEV+ERL did not inhibit growth more than BEV. BEV alone significantly decreased microvessel density in each tumor. In conclusion, addition of BEV to ERL did not enhance antitumor activity in primarily ERL-resistant tumors with T790M mutation; however, BEV+ERL enhanced antitumor activity in T790M mutation- or MET amplification-positive tumors as long as their growth remained significantly suppressed by ERL. PMID:26370161

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

    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

  17. [3rd generation's TKI in lung cancer non-small cell EGFR-mutated having acquired a secondary T790M resistance].

    Brosseau, Solenn; Viala, Marie; Varga, Andréa; Planchard, David; Besse, Benjamin; Soria, Jean-Charles

    2015-09-01

    Activating EGFR mutations discovery and efficacy of 1st generation tyrosine kinase inhibitors (TKI), such as erlotinib or gefitinib, inaugurated the beginning of personalized medicine in the treatment of EGFR-mutated non-small cell lung cancer (NSCLC). However, all patients showed a tumor progression of 10 to 16 months after the onset of TKI therapy related to molecular resistance mechanisms as T790M mutation. Till now, patients suffering from EGFR-mutated NSCLC with acquired resistance have conventional treatment options. Two new 3rd generations' TKI, AZD9291 and rociletinib, are currently being studied in phases 1-3 studies. Preliminary results show relevant therapeutic properties in patients with T790M mutated-EGFR NSCLC. This review aims to highlight these new molecules, their effectiveness and their clinical toxicities in the treatment of advanced stages of NSCLC expressing the T790M mutation. PMID:26235419

  18. EGFR-independent autophagy induction with gefitinib and enhancement of its cytotoxic effect by targeting autophagy with clarithromycin in non-small cell lung cancer cells.

    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. PMID:25858318

  19. Immunohistochemical expression of SP-NK-1R-EGFR pathway and VDR in colonic inflammation and neoplasia

    Isidro, Raymond A; Cruz, Myrella L; Isidro, Angel A; Baez, Axel; Arroyo, Axel; González-Marqués, William A; González-Keelan, Carmen; Torres, Esther A.; Appleyard, Caroline B.

    2015-01-01

    AIM: To determine the expression of neurokinin-1 receptor (NK-1R), phosphorylated epidermal growth factor receptor (pEGFR), cyclooxygenase-2 (Cox-2), and vitamin D receptor (VDR) in normal, inflammatory bowel disease (IBD), and colorectal neoplasia tissues from Puerto Ricans.

  20. Integrated genomic approaches identify upregulation of SCRN1 as a novel mechanism associated with acquired resistance to erlotinib in PC9 cells harboring oncogenic EGFR mutation

    Kim, Nayoung; Cho, Ahye; Watanabe, Hideo; Choi, Yoon-La; Aziz, Meraj; Kassner, Michelle; Joung, Je-Gun; Park, Angela KJ; 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

    2016-01-01

    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. PMID:26883194

  1. 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

    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...

  2. Determination of rhenium in molybdenite by neutron-activation analysis.

    Terada, K; Yoshimura, Y; Osaki, S; Kiba, T

    1967-01-01

    A neutron-activation method is described for the determination of rhenium in molybdenite. Radiochemical separation by a carrier technique was carried out very rapidly by means of successive liquid-liquid extraction processes. The recovery of rhenium, which was determined by a spectrophotometric method, was about 93%. About 10 samples could be analysed within 6 hr in parallel runs. PMID:18960067

  3. Gold determination in massive samples by neutron activation analysis

    Broglio, Eduardo

    2015-01-01

    This work presents the characteristics of the Neutron Activation Analysis (NAA) in the determination of gold in voluminous mineral samples using a linear particle accelerator (Linac) as source of irradiation. The used volumes are one or two orders of magnitude higher than the ones that can be used in nuclear research reactor, which is the source usually used to determine through the NAA. This study was encouraged by a specific legal requirement to determine the gold law in a small Patagonian gold deposit.

  4. Genetic Variation in the EGFR Gene and the Risk of Glioma in a Chinese Han Population

    Hou, Wu-Gang; Ai, Wen-Bo; Bai, Xiao-Guang; Dong, Hai-long; Li, Zhen; Zhang, Yuan-Qiang; Xiong, Li-Ze

    2012-01-01

    Previous studies have shown that regulation of the epidermal growth factor gene (EGFR) pathway plays a role in glioma progression. Certain genotypes of the EGFR gene may be related to increased glioblastoma risk, indicating that germ line EGFR polymorphisms may have implications in carcinogenesis. To examine whether and how variants in the EGFR gene contribute to glioma susceptibility, we evaluated nine tagging single-nucleotide polymorphisms (tSNPs) of the EGFR gene in a case–control study f...

  5. Rapid determination of antifungal activity by flow cytometry.

    Green, L.; Petersen, B.; Steimel, L; Haeber, P; Current, W

    1994-01-01

    We have developed a rapid assay of antifungal activity which utilizes flow cytometry to detect accumulation of a vital dye in drug-damaged fungal cells. Results of these studies suggest that flow cytometry may provide an improved, rapid method for determining and comparing the antifungal activities of compounds with differing modes of action.

  6. Determination of average activating thermal neutron flux in bulk samples

    A previous method used for the determination of the average neutron flux within bulky samples has been applied for the measurements of hydrogen contents of different samples. An analytical function is given for the description of the correlation between the activity of Dy foils and the hydrogen concentrations. Results obtained by the activation and the thermal neutron reflection methods are compared

  7. The caenorhabditis elegans CDT-2 ubiquitin ligase is required for attenuation of EGFR signalling in vulva precursor cells

    Ahringer Julie

    2010-10-01

    Full Text Available Abstract Background Attenuation of the EGFR (Epidermal Growth Factor Receptor signalling cascade is crucial to control cell fate during development. A candidate-based RNAi approach in C. elegans identified CDT-2 as an attenuator of LET-23 (EGFR signalling. Human CDT2 is a component of the conserved CDT2/CUL4/DDB1 ubiquitin ligase complex that plays a critical role in DNA replication and G2/M checkpoint. Within this complex, CDT2 is responsible for substrate recognition. This ubiquitin ligase complex has been shown in various organisms, including C. elegans, to target the replication-licensing factor CDT1, and the CDK inhibitor p21. However, no previous link to EGFR signalling has been identified. Results We have characterised CDT-2's role during vulva development and found that it is a novel attenuator of LET-23 signalling. CDT-2 acts redundantly with negative modulators of LET-23 signalling and CDT-2 or CUL-4 downregulation causes persistent expression of the egl-17::cfp transgene, a marker of LET-23 signalling during vulva development. In addition, we show that CDT-2 physically interacts with SEM-5 (GRB2, a known negative modulator of LET-23 signalling that directly binds LET-23, and provide genetic evidence consistent with CDT-2 functioning at or downstream of LET-23. Interestingly, both SEM-5 and CDT-2 were identified independently in a screen for genes involved in receptor-mediated endocytosis in oocytes, suggesting that attenuation of LET-23 by CDT-2 might be through regulation of endocytosis. Conclusions In this study, we have shown that CDT-2 and CUL-4, members of the CUL-4/DDB-1/CDT-2 E3 ubiquitin ligase complex attenuate LET-23 signalling in vulval precursor cells. In future, it will be interesting to investigate the potential link to endocytosis and to determine whether other signalling pathways dependent on endocytosis, e.g. LIN-12 (Notch could be regulated by this ubiquitin ligase complex. This work has uncovered a novel function

  8. Physical activity as an important determinant in developing childhood obesity

    Bukara-Radujković Gordana; Zdravković Dragan

    2009-01-01

    The correlation between physical activity and sedentary life style was investigated as a determinant of the body mass index in children and adolescents in Banjaluka region. The study involved 1204 children and adolescents, 6-17 years old, 578 boys, 626 girls. BMI was calculated from their height and weight using standard formula. Each child, together with their parents answered the questions considering their level of involvement in physical versus sedentary activities. Physical activity was ...

  9. Determination of the antioxidant activity of Ficus carica aqueous extract

    Trifunski Svetlana I.; Ardelean Dorina G.

    2012-01-01

    The aim of this study was to examine the antioxidant activity of water extracts from fig leaf. Water extracts were prepared according to traditional medicine. The antioxidant activity of the extracts was spectrophotometrically determined. Using the potassium permanganate colorimetric method it was found that the water extract that was maintained at the refrigerator had lower antioxidant activity than extract that was maintained at the room temperature.

  10. Development of a new biosensor for determination of catalase activity.

    Teke, Mustafa

    2014-01-01

    Catalase is one of the major antioxidant enzymes that catalyzes the hydrolysis of H2O2. The aim of this study was to suggest a new method for the assay of catalase activity. For this purpose, an amperometric biosensor based on glucose oxidase for determination of catalase activity was developed. Immobilization of glucose oxidase was made by a cross-linking method with glutaraldehyde on a Clark-type electrode (dissolved oxygen probe). Optimization and characterization properties of the biosensor were studied and determination of catalase activity in defined conditions was investigated in artificial serum solution. The results were compared with a reference method. PMID:24499365

  11. A drosophila model for EGFR-Ras and PI3K-dependent human glioma.

    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.

  12. Effects of EGFR Gene Polymorphisms on Efficacy and Prognosis 
in Advanced Non-small Cell Lung Cancer Treated with EGFR-TKIs

    Liangshan DA

    2013-03-01

    Full Text Available An increasing number of patients with advanced non-small cell lung cancer (NSCLC have been treated with epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs. However, significant differences in response to EGFR-TKIs have been shown among advanced NSCLC patients. Recently, selection of patients was mainly based on EGFR gene mutation detection. Nevertheless, mutation detection is often limited by tumour tissues derivation, technique complexity, high cost, and so on. It is urgent to seek other biological markers to predict efficacy of EGFR-TKIs. Many studies have founded that the EGFR gene polymorphisms are also associated with clinical outcome and prognosis in treatment of advanced NSCLC with EGFR-TKIs. Here, we presented a review discussing the correlation between EGFR gene polymorphisms and the efficacy of EGFR-TKIs in advanced NSCLC.

  13. Redirecting T-Cell Specificity to EGFR Using mRNA to Self-limit Expression of Chimeric Antigen Receptor.

    Caruso, Hillary G; Torikai, Hiroki; Zhang, Ling; Maiti, Sourindra; Dai, Jianliang; Do, Kim-Anh; Singh, Harjeet; Huls, Helen; Lee, Dean A; Champlin, Richard E; Heimberger, Amy B; Cooper, Laurence J N

    2016-06-01

    Potential for on-target, but off-tissue toxicity limits therapeutic application of genetically modified T cells constitutively expressing chimeric antigen receptors (CARs) from tumor-associated antigens expressed in normal tissue, such as epidermal growth factor receptor (EGFR). Curtailing expression of CAR through modification of T cells by in vitro-transcribed mRNA species is one strategy to mitigate such toxicity. We evaluated expression of an EGFR-specific CAR coded from introduced mRNA in human T cells numerically expanded ex vivo to clinically significant numbers through coculture with activating and propagating cells (AaPC) derived from K562 preloaded with anti-CD3 antibody. The density of AaPC could be adjusted to affect phenotype of T cells such that reduced ratio of AaPC resulted in higher proportion of CD8 and central memory T cells that were more conducive to electrotransfer of mRNA than T cells expanded with high ratios of AaPC. RNA-modified CAR T cells produced less cytokine, but demonstrated similar cytolytic capacity as DNA-modified CAR T cells in response to EGFR-expressing glioblastoma cells. Expression of CAR by mRNA transfer was transient and accelerated by stimulation with cytokine and antigen. Loss of CAR abrogated T-cell function in response to tumor and normal cells expressing EGFR. We describe a clinically applicable method to propagate and modify T cells to transiently express EGFR-specific CAR to target EGFR-expressing tumor cells that may be used to limit on-target, off-tissue toxicity to normal tissue. PMID:27163741

  14. Erlotinib Versus Radiation Therapy for Brain Metastases in Patients With EGFR-Mutant Lung Adenocarcinoma

    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.

  15. Erlotinib Versus Radiation Therapy for Brain Metastases in Patients With EGFR-Mutant Lung Adenocarcinoma

    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

  16. Role of [18F]FDG PET in prediction of KRAS and EGFR mutation status in patients with advanced non-small-cell lung cancer

    The tumour molecular profile predicts the activity of epidermal growth factor receptor (EGFR) inhibitors in non-small-cell lung cancer (NSCLC). However, tissue availability and tumour heterogeneity limit its assessment. We evaluated whether [18F]FDG PET might help predict KRAS and EFGR mutation status in NSCLC. Between January 2005 and October 2011, 340 NSCLC patients were tested for KRAS and EGFR mutation status. We identified patients with stage III and IV disease who had undergone [18F]FDG PET/CT scanning for initial staging. SUVpeak, SUVmax and SUVmean of the single hottest tumour lesions were calculated, and their association with KRAS and EGFR mutation status was assessed. A receiver operator characteristic (ROC) curve analysis and a multivariate analysis (including SUVmean, gender, age and AJCC stage) were performed to identify the potential value of [18F]FDG PET/CT for predicting KRAS mutation. From 102 patients staged using [18F]FDG PET/CT, 28 (27 %) had KRAS mutation (KRAS+), 22 (22 %) had EGFR mutation (EGFR+) and 52 (51 %) had wild-type KRAS and EGFR profiles (WT). KRAS+ patients showed significantly higher [18F]FDG uptake than EGFR+ and WT patients (SUVmean 9.5, 5.7 and 6.6, respectively; p 18F]FDG uptake between EGFR+ patients and WT patients. ROC curve analysis for KRAS mutation status discrimination yielded an area under the curve of 0.740 for SUVmean (p 18F]FDG uptake than WT patients, as assessed in terms of SUVpeak, SUVmax and SUVmean. A multivariate model based on age, gender, AJCC stage and SUVmean might be used as a predictive marker of KRAS mutation status in patients with stage III or IV NSCLC. (orig.)

  17. Radiolabeled Cetuximab Conjugates for EGFR Targeted Cancer Diagnostics and Therapy

    Wiebke Sihver; Jens Pietzsch; Mechthild Krause; Michael Baumann; Jörg Steinbach; Hans-Jürgen Pietzsch

    2014-01-01

    The epidermal growth factor receptor (EGFR) has evolved over years into a main molecular target for the treatment of different cancer entities. In this regard, the anti-EGFR antibody cetuximab has been approved alone or in combination with: (a) chemotherapy for treatment of colorectal and head and neck squamous cell carcinoma and (b) with external radiotherapy for treatment of head and neck squamous cell carcinoma. The conjugation of radionuclides to cetuximab in combination with the specif...

  18. Neural cell adhesion molecule-180-mediated homophilic binding induces epidermal growth factor receptor (EGFR) down-regulation and uncouples the inhibitory function of EGFR in neurite outgrowth

    Povlsen, Gro Klitgaard; Berezin, Vladimir; Bock, Elisabeth

    2008-01-01

    The neural cell adhesion molecule (NCAM) plays important roles in neuronal development, regeneration, and synaptic plasticity. NCAM homophilic binding mediates cell adhesion and induces intracellular signals, in which the fibroblast growth factor receptor plays a prominent role. Recent studies on...... this NCAM-180-induced EGFR down-regulation involves increased EGFR ubiquitination and lysosomal EGFR degradation. Furthermore, NCAM-180-mediated EGFR down-regulation requires NCAM homophilic binding and interactions of the cytoplasmic domain of NCAM-180 with intracellular interaction partners, but does...

  19. Digital PCR analysis of plasma cell-free DNA for non-invasive detection of drug resistance mechanisms in EGFR mutant NSCLC: Correlation with paired tumor samples

    Ishii, Hidenobu; Azuma, Koichi; Sakai, Kazuko; Kawahara, Akihiko; Yamada, Kazuhiko; Tokito, Takaaki; Okamoto, Isamu; Nishio, Kazuto; Hoshino, Tomoaki

    2015-01-01

    As the development of resistance to epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) has become an issue of concern, identification of the mechanisms responsible has become an urgent priority. However, for research purposes, it is not easy to obtain tumor samples from patients with EGFR mutation-positive non-small-cell lung cancer (NSCLC) that has relapsed after treatment with EGFR-TKIs. Here, using digital PCR assay as an alternative and noninvasive method, we examined plasma and tumor samples from patients with relapsed NSCLC to establish the inter-relationships existing among T790M mutation, activating EGFR mutations, HER2 amplification, and MET amplification. Paired samples of tumor and blood were obtained from a total of 18 patients with NSCLC after they had developed resistance to EGFR-TKI treatment, and the mechanisms of resistance were analyzed by digital PCR. Digital PCR analysis of T790M mutation in plasma had a sensitivity of 81.8% and specificity of 85.7%, the overall concordance between plasma and tissue samples being 83.3%. MET gene copy number gain in tumor DNA was observed by digital PCR in three patients, of whom one exhibited positivity for MET amplification by FISH, whereas no patient demonstrated MET and HER2 copy number gain in plasma DNA. Digital PCR analysis of plasma is feasible and accurate for detection of T790M mutation in NSCLC that becomes resistant to treatment with EGFR-TKIs. PMID:26334838

  20. EGFR signaling in colorectal cancer: a clinical perspective

    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

  1. EGFR tyrosine kinase inhibitory peptide attenuates Helicobacter pylori-mediated hyper-proliferation in AGS enteric epithelial cells

    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. EGFR tyrosine kinase inhibitory peptide attenuates Helicobacter pylori-mediated hyper-proliferation in AGS enteric epithelial cells

    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

  3. Regulation of EGFR signal transduction by analogue-to-digital conversion in endosomes

    Villaseñor, Roberto; Nonaka, Hidenori; Del Conte-Zerial, Perla; Kalaidzidis, Yannis; Zerial, Marino

    2015-01-01

    An outstanding question is how receptor tyrosine kinases (RTKs) determine different cell-fate decisions despite sharing the same signalling cascades. Here, we uncovered an unexpected mechanism of RTK trafficking in this process. By quantitative high-resolution FRET microscopy, we found that phosphorylated epidermal growth factor receptor (p-EGFR) is not randomly distributed but packaged at constant mean amounts in endosomes. Cells respond to higher EGF concentrations by increasing the number of endosomes but keeping the mean p-EGFR content per endosome almost constant. By mathematical modelling, we found that this mechanism confers both robustness and regulation to signalling output. Different growth factors caused specific changes in endosome number and size in various cell systems and changing the distribution of p-EGFR between endosomes was sufficient to reprogram cell-fate decision upon EGF stimulation. We propose that the packaging of p-RTKs in endosomes is a general mechanism to ensure the fidelity and specificity of the signalling response. DOI: http://dx.doi.org/10.7554/eLife.06156.001 PMID:25650738

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

    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.

  5. Dynamic Bayesian Network Modeling of the Interplay between EGFR and Hedgehog Signaling.

    Fröhlich, Holger; Bahamondez, Gloria; Götschel, Frank; Korf, Ulrike

    2015-01-01

    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. PMID:26571415

  6. Dynamic Bayesian Network Modeling of the Interplay between EGFR and Hedgehog Signaling.

    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.

  7. Molecular docking, MM/GBSA and 3D-QSAR studies on EGFR inhibitors

    RAJU BATHINI; SREE KANTH SIVAN; SABIHA FATIMA; VIJJULATHA MANGA

    2016-07-01

    Epidermal growth factor receptor (EGFR) is the first growth factor receptor proposed as a target for cancer therapy. Molecular modeling protocols like molecular docking, molecular mechanics/generalized born surface area (MM/GBSA) calculations and three dimensional-quantitative structure activity relationship(3D-QSAR) studies were performed on 45 molecules to understand the structural requirements for EGFR tyrosine kinase inhibitors. Conformation for all the molecules obtained from molecular docking were used as is for 3D-QSAR analysis. Comparative molecular field analysis (CoMFA) and comparative molecular similarityindices analysis (CoMSIA) models were obtained by performing partial least square analysis on 35 training molecules and these models were validated using 10 test moleucles. The models showed good statistical results in terms of r², q² loo and r² pred values. Information rendered from 3D-QSAR model and sitemap analysis was used to optimize lead molecule to design prospective inhibitors. Improvement in EGFR binding affinity can be achieved by substitutional modification on phenyl ring attached to alkynyl group with bulkier hydrogen bond donor and acceptor substituents that can increase favourable interaction with the receptor.

  8. Protein determination in soya bean by fast neutron activation analysis

    For a non-destructive determination of the protein content in soya bean samples, 14-MeV neutron activation analysis was applied. To check the method, the results obtained by X-ray fluorescence analysis and the Kjeldahl procedure were compared. For pressed pellet samples of about 1 g with 15 min irradiation and 10 min measuring times the accuracy of the protein determination was found to be 15%. (author) 7 refs.; 4 figs.; 3 tabs

  9. Determination of mercury in food by neutron activation

    Determination of mercury in food samples has been carried out by neutron activation followed by chemical separation to remove the interfering activities of copper, zinc etc. Chemical separation was carried out using anion exchange resin (DOWEX 1x8). Mercury was determined by counting 77 keV γ-rays of 197Hg on a NaI(Tl) crystal in conjunction with a 400-channel pulse-height analyser. Levels of mercury in the following foods are tabulated: rice, wheat, pulses, millets, leafy vegetables, flower, carrot, potato, tomato, onion, chilli powder, sugar, tea leaves, milk. (T.I.)

  10. Direct potentiometric determination of diastase activity in honey.

    Sak-Bosnar, Milan; Sakač, Nikola

    2012-11-15

    A novel method for the determination of diastase activity is reported. The method is based on a direct potentiometric measurement of triiodide ion that is released when a starch-triiodide complex is hydrolysed by honey diastase. The increase of free triiodide ion concentration in a sample is found to be directly proportional to the diastase activity of the sample. A response mechanism of the platinum redox electrode is proposed, allowing a calculation of the diastase activity factor (F). The sensor and analyte parameters, including F, were obtained by least squares fitting of potentiometric data using the optimisation function of the Solver add-in of Microsoft Excel. The values of F obtained by the new direct potentiometric method were compared with those obtained using the standard Phadebas method (DN values), and the two values were found to agree within experimental error. Finally, the diastase activity of nine varieties of honey was determined using the novel method developed here. PMID:22868165

  11. Metallic samples specific activity determination by mathematical modelling

    The problem of specific activity determination of metallic samples containing radionuclides has been generally solved for a subject demanded by Iron and Steel Workes Galati. In order to establish the dependence between specific activity and the counting rate furnished by the counting equipment, the method used consists in mathematical modelling of the sample detector assembly as well as of the pertinent physical processes. The method and obtained results are described. (author)

  12. DETERMINANTS OF LEISURE-TIME PHYSICAL ACTIVITY: EVIDENCE FROM MALAYSIA

    YONG KANG CHEAH; Tan, Andrew K.G.

    2014-01-01

    This paper examines how socio-demographic and health-lifestyle factors determine participation and duration of leisure-time physical activity in Malaysia. Based on the Malaysia Non-Communicable Disease Surveillance-1 data, Heckman's sample selection model is employed to estimate the probability to participate and duration on physical activity. Results indicate that gender, age, years of education and family illness history are significant in explaining participation probability in leisure-tim...

  13. Mercury determination in natural waters using neutron activation analysis

    Available as short communication only. An analytical method for quantitative determination of Mercury traces in river and sea water is proposed. The neutron activation method and radiochemical separation of Mercury by developing of C L4 Hg-2 complex, and their chromatographic separation using anionic exchange resin Dowex 1 X 8 of 400 mesh is used. The quantitative determination is done by gamma spectrometric analysis. The selection limits reached with this method showed that this is an amenable procedure in routine mercury determination in the ppb level, specially useful in the environmental contamination analysis. (author). 3 refs, 2 figs, 1 tab

  14. Determining and Accounting of Fair Value in Agricultural Activities

    Ahmet GÖKGÖZ

    2012-12-01

    Full Text Available Biological assets and agricultural products bring about the subject of agricultural production. Having biological transformation of biological assets and agricultural products via the cases such as growth, reproduction, deterioration, decay; makes the valuation of agricultural activities important. The Fair Value Approach is adopted in TAS 41, the Agricultural Activities Standard regulating agricultural activities, about the valuation of biological assets and agricultural products. In the study; determining process of biological assets and agricultural products’ fair value adopted by TAS 41 is explained. Afterwards; recording of increase and decrease, occured due to the valuation by the framework of TAS 41, through the accounts offered to the Uniform Chart of Accounts.

  15. Methods for determining keratinolytic activity of saprophytic fungi

    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. Role of EGFR transactivation in angiotensin II signaling to extracellular regulated kinase in preglomerular smooth muscle cells.

    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. PMID:12623996

  17. The absolute determination of activity by the efficiency extrapolation method

    As agent for the Commonwealth Scientific and Industrial Research Organisation, the Australian Atomic Energy Commission is responsible for the maintenance of the Australian standard of activity. The standard comprises activity measurement procedures involving the operation of 4 π β-γ coincidence counting equipment. The coincidence method requires the application of correction factors which depend on detection efficiency, such as arise for complex decay schemes and internal conversion. These corrections approach unity as the detection efficiency in the β-channel approaches 100 per cent. By performing activity determinations for a range of β detection efficiencies, an 'efficiency extrapolation' analysis can be applied which eliminates the need to determine the absolute detection efficiency for each channel

  18. Epidermal growth factor receptor (EGFR) antisense transfection reduces the expression of EGFR and suppresses the malignant phenotype of a human ovarian cancer cell line.

    Brader, K R; Wolf, J K; Chakrabarty, S; Price, J E

    1998-01-01

    An EGFR-expressing clone of the human ovarian cancer line 2774 was transfected with an antisense construct of EGFR to test how suppression of this gene modulates the malignant phenotype. Transfected clones were screened for EGFR expression by Western blot and FACS analysis. Anchorage-independent growth was used to assess the effect of reduced EGFR on the malignant behavior of the cells. Several transfected clones with decreased EGFR (40-50% reduction) were identified. A correlation was noted between reduced EGFR and decreased anchorage-independent growth, with the transfected clones losing the ability to grow in agarose and responsiveness to exogenous EGF. These results suggest that EGFR may be an important factor in the malignant behavior of this ovarian cancer cell line. PMID:9683849

  19. Ganoderma lucidum Combined with the EGFR Tyrosine Kinase Inhibitor, Erlotinib Synergize to Reduce Inflammatory Breast Cancer Progression.

    Suárez-Arroyo, Ivette J; Rios-Fuller, Tiffany J; Feliz-Mosquea, Yismeilin R; Lacourt-Ventura, Mercedes; Leal-Alviarez, Daniel J; Maldonado-Martinez, Gerónimo; Cubano, Luis A; Martínez-Montemayor, Michelle M

    2016-01-01

    The high incidence of resistance to Tyrosine Kinase Inhibitors (TKIs) targeted against EGFR and downstream pathways has increased the necessity to identify agents that may be combined with these therapies to provide a sustained response for breast cancer patients. Here, we investigate the therapeutic potential of Ganoderma lucidum extract (GLE) in breast cancer, focusing on the regulation of the EGFR signaling cascade when treated with the EGFR TKI, Erlotinib. SUM-149, or intrinsic Erlotinib resistant MDA-MB-231 cells, and a successfully developed Erlotinib resistant cell line, rSUM-149 were treated with increasing concentrations of Erlotinib, GLE, or their combination (Erlotinib/GLE) for 72h. Treatment effects were tested on cell viability, cell proliferation, cell migration and invasion. To determine tumor progression, severe combined immunodeficient mice were injected with SUM-149 cells and then treated with Erlotinib/GLE or Erlotinib for 13 weeks. We assessed the protein expression of ERK1/2 and AKT in in vitro and in vivo models. Our results show that GLE synergizes with Erlotinib to sensitize SUM-149 cells to drug treatment, and overcomes intrinsic and developed Erlotinib resistance. Also, Erlotinib/GLE decreases SUM-149 cell viability, proliferation, migration and invasion. GLE increases Erlotinib sensitivity by inactivating AKT and ERK signaling pathways in our models. We conclude that a combinatorial therapeutic approach may be the best way to increase prognosis in breast cancer patients with EGFR overexpressing tumors. PMID:26958085

  20. Combined EGFR and VEGFR versus single EGFR signaling pathways inhibition therapy for NSCLC: a systematic review and meta-analysis.

    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

  1. Physical activity as an important determinant in developing childhood obesity

    Bukara-Radujković Gordana

    2009-01-01

    Full Text Available The correlation between physical activity and sedentary life style was investigated as a determinant of the body mass index in children and adolescents in Banjaluka region. The study involved 1204 children and adolescents, 6-17 years old, 578 boys, 626 girls. BMI was calculated from their height and weight using standard formula. Each child, together with their parents answered the questions considering their level of involvement in physical versus sedentary activities. Physical activity was defined as involvement in sports activities, while sedentary life style was defined as time spent on computer, games, video, and TV. The prevalence of overweight and obesity were 12.2% and 6.1% in our study group. Increased physical activity showed strong positive correlation with normal, lower BMI in boys (p<0,05, and girls (p<0.001. Sedentary lifestyle, prolonged TV watching was strongly associated with increased BMI only in girls (p<0.05. However, computer use for 2 hours/day was strongly associated with increased BMI (p<0.05 only in boys, although computer use for more than 3 hours/day was associated with lower BMI in boys. Physical activity and sedentary lifestyle are significant determinants of BMI and risk factors in developing overweight and obesity in childhood, as shown in our study.

  2. Development of personalized treatments in lung cancer: focusing on the EGFR mutations and beyond

    Suda K

    2013-08-01

    Full Text Available Kenichi Suda,1,2 Tetsuya Mitsudomi1 1Division of Thoracic Surgery, Department of Surgery, Kinki University Faculty of Medicine, Osaka-Sayama, Japan; 2Department of Surgery and Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan Abstract: Lung cancers with epidermal growth factor receptor (EGFR gene mutation account for ~40% of adenocarcinoma in East Asians and ~15% of that in Caucasians, which makes them one of the most common molecularly defined lung cancer subsets. The role of EGFR mutation as a strong predictive biomarker of response to EGFR-tyrosine kinase inhibitors (TKIs was finally confirmed by the biomarker analysis of Iressa Pan-Asian Study (IPASS. Since the 2004 discovery of EGFR mutation in lung cancer, the EGFR mutation and EGFR-TKI treatment have been widely studied. These include characteristics of lung cancers with EGFR mutations; clinical efficacies and adverse effects of EGFR-TKIs in patients with EGFR-mutated lung cancers; development of novel EGFR-TKIs that may prolong progression-free survival of these patients or overcome resistance to first-generation EGFR-TKIs (gefitinib and erlotinib; optimal treatment schedules for EGFR-TKIs to delay emergence of resistance; molecular mechanisms of acquired resistance to EGFR-TKIs; treatment strategies after patients acquire resistance to EGFR-TKIs; and predictive biomarkers for EGFR-TKIs among patients with EGFR-mutated lung cancers. Some of these results are widely accepted, while others are apparent only in cell line models, preclinical animal models, or retrospective analyses (and sometimes conflict with each other. In this review, we summarize accumulated reports from the past decade, especially focusing on unanswered but important clinical questions in treating patients with EGFR-mutated lung cancers. Keywords: epidermal growth factor receptor mutation, predictive biomarkers, personalized therapy, molecular target, adjuvant therapy, acquired resistance

  3. Over-expression of EGFR in Breast Cancer

    BO Ai-hua; HOU Jin-chao; LAN Yong-hao; TIAN Ya-ting; ZHANG Jun-yan

    2008-01-01

    Objective:To explore the relationship of overexpression of epidermal growth factor receptor(EGFR)in occurrence,development and treatment of breast cancer. Methods:Samples of 46 breast adenoma tissues and 86 breast cancer tissues were regularly dehydrate-fixed,embedded in paraffin,sliced in to 5 μm thick,stained with SABC immunohistochemistry and coloured with DAB. Results:The positive staining of EGFR was shown as brown- yellow and distributed in cytoplasm.The positive rates in the tissues of breast adenosis and breast cancer were 17.04%(6/46)and 56.98%(49/86)respectively.The positive rates of EGFR in the tissue of invasive ductal carcinoma was 64.49%(41/59),which was significantly higher than that in in situ carcinoma(P<0.05).The positive rate of lymph metastasis group was higher than that in non-lymph metastasis group (P<0.05). Conclusion:The overexpression of EGFR was related with occurrence,lymph metastasis and pathologic types of breast cancer.The examination of EGFR in the breast cancer can serve as a guidance for target chemotherapy.

  4. Correlation between egfr expression and accelerated proliferation during radiotherapy of head and neck squamous cell carcinoma

    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

  5. Correlation between egfr expression and accelerated proliferation during radiotherapy of head and neck squamous cell carcinoma

    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

  6. Determinants of Foreign Technological Activity in German Regions

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

    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 fo...... non-linear and that it is influenced by sectoral heterogeneity. Externalities related to technological diversification attract foreign R&D only into ‘higher order’ regions....... 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...

  7. Determinants of clean development mechanism activity: Evidence from China

    As regards the dual goals of additionality and sustainability, some clean development mechanism (CDM) projects were successfully registered while some were rejected by the Executive Board (EB). This paper focuses on two final statuses of these projects and aims to explore the potential determinants of CDM activities. Based on the Chinese samples of the rejections and registrations, we find that (1) according to the financial barrier analysis with the internal rate of return without CDM, the additionality is the most important and robust rule of CDM activities and the CDM projects successfully registered are more additional than the rejected ones in China; (2) the sustainability is another important determinant of CDM activities in China and Chinese CDM activities are sustainable in terms of size, while the EB is criticized for its selection of unsustainable CDM projects in terms of cost-effectiveness on emission reductions within a long period or in terms of hydropower plants; (3) some other factors including the prices of sale electricity and certified emission reductions, the generating capacity and installed capacity all tend to pose significant impacts on the final status of each project that features the CDM activities in local areas of China. - Highlights: • The final status of each project features the CDM activities in local areas. • Microeconomic factors have significant impacts on the final statuses. • The additionality is the most important and robust rule of CDM activities in China. • Chinese CDM activities are sustainable in terms of size. • Chinese unsustainable CDM projects were selected by the EB in terms of cost-effectiveness

  8. Human monoamine oxidase A gene determines levels of enzyme activity.

    Hotamisligil, G S; Breakefield, X O

    1991-01-01

    Monoamine oxidase (MAO) is a critical enzyme in the degradative deamination of biogenic amines throughout the body. Two biochemically distinct forms of the enzyme, A and B, are encoded in separate genes on the human X chromosome. In these studies we investigated the role of the structural gene for MAO-A in determining levels of activity in humans, as measured in cultured skin fibroblasts. The coding sequence of the mRNA for MAO-A was determined by first-strand cDNA synthesis, PCR amplificatio...

  9. Determination of mercury in dentists through Neutron activation analysis

    It was determined the mercury levels in urine through Neutron activation analysis to 25 dentists who have been exposed to mercury by several time periods, because of the routine manipulations of amalgams. The determined concentrations of mercury were less to 10 μ g Hg/l of urine. The results were founded inside the safety limits reported in the literature. The mercury levels in the dentists are associated with a wide variety of factors that contribute to their exposure as: number of years of dental practice, number of amalgams manipulated between others. (Author)

  10. Determination of thorium in human urine by neutron activation

    A routine procedure for the determination of thorium in urine of workers has been developed by the neutron activation method. The technique suggested by Dang, et. al. has been modified in order to reduce the cost involved and the sample processing time. The samples were irradiated in the MIT (Massachusetts Institute of Technology-Boston) reactor, in a thermal neutron flux of 8 x 10 12n.cm-2.s-1 for 3,5 hours. Thorium-232 was determined by counting 233Pa. (author) 6 refs.; 2 tabs

  11. Improved response by co-targeting EGFR/EGFRvIII and Src family kinases in human cancer cells

    Andersen, Peter; Villingshøj, Mette; Poulsen, Hans Skovgaard; Stockhausen, Marie-Thérése

    2009-01-01

    We hypothesized that co-targeting the epidermal growth factor receptor (EGFR) and Src with the EGFR inhibitor gefitinib and the Src inhibitor AZD0530 would increase growth inhibition and impede migration. Cells overexpressing EGFR were more sensitive to gefitinib than cells expressing mutated EGFR...... or normal levels of wild-type EGFR. Furthermore, cells with mutated EGFR responded to low doses of gefitinib with increased proliferation. AZD0530 was an effective inhibitor of proliferation and migration, irrespective of EGFR status. These results suggest that co-targeting EGFR and Src might be a...

  12. Determination of sodium in pharmaceuticals by neutron activation analysis

    A simple, fast and accurate neutron activation analysis method for determination of Na in drugs concerning either active compound or total content was developed. The examined dosage forms consisted of 10 injectable ampoules and 10 bottles of oral solutions. The irradiation of samples and standards was carried out in the rotation system of the Reactor of Nuclear Research Center Democritos with maximal neutron flux of 2,9.1013 n.cm-2.sec-1. Gamma-ray spectrometry of the irradiated samples and standards was accomplished with a coaxial Ge(Li) detector series Win 15 with an efficiency of 15% connected to an Ino-Tech 1024 channel analyser (Model IT 5200). The accuracy and precision of the method are found to be very high and therefore it could be established as an official one for the determination of sodium in parmaceuticals

  13. EGFR-Targeted Therapeutics: Focus on SCCHN and NSCLC

    Martin Sattler

    2008-01-01

    Full Text Available Cancers of the head and neck and of the lung are associated with high morbidity and mortality rates that have remained relatively unchanged for more than 3 decades, despite advances in radiation therapies and chemotherapies over the same time. It is generally believed that the efficacy of standard therapy regimens has reached a plateau for these cancers. The discovery of specific aberrant molecular signaling pathways in solid tumors has afforded promising new directions for newer “targeted” cancer therapeutics. Among these, the epidermal growth factor receptor (EGFR shows promise as a therapeutic target. Clinical studies have demonstrated that this targeted approach provides clinically meaningful benefit. This article reviews EGFR-targeted therapies in use and in development, with a focus on the role of EGFR in the pathophysiology of head and neck and lung cancer, and new concepts being investigated to improve outcomes with these agents.

  14. The combined status of estrogen receptor (ER) and epidermal growth factor (EGFR) predicts a poor outcome in primary breast cancer

    The aim of this study was to investigate retrospectively the presence of ER, PR, Db Receptor and Epidermal Growth Factor (EGFR) in 678 patients carrying primary breast cancer, its correlation with clinic pathological parameters and evolution. the determination of ER, PR and EGFR was performed by Scatchard biochemical technique, based cutoff 10 fmoles / mg of protein. The RE-b detection performed by RT-PCR from total RNA, using the GAPDH gene as a control. Statistical analyzes were applied the Chi2 tests, Spearman and Kruskal-Wallis. The disease-free survival (SVLE) and survival overall (SVG) were analyzed using Kaplan Meier / Log Rank Test and analysis Cox regression. Median follow-up was 28 months (range 1-218 months). sixty Four percent of the patients were post-menopausal and 83% occurred in stages Early disease (I-II, pTNM UICC). The receptor positivity was 68%, 47%, 23% and 58% for ER, PR, EGFR and ER-b-mRNA, respectively. A correlation was found positive between the content of ER and PR (p = 1.10-5) and negative between these receptors and EGFR (n = 359, p = 0.014 and p = 0.018, respectively). We observed a trend to increased expression ER-b when ER, PR or both receptors were negative comparable to that observed with EGFR. Also, a gradual decrease in the content of ER and PR was observed with the progression to more advanced stages (p = 0.04 and p = 0.03). Of a total of 501 evaluable patients 23% relapsed and 12% died. ER positivity was associated with a greater SVLE and SVG 24 and 60 months follow up (p = 0.06). A major impact did the RE content, levels less than 45 fmol / mg protein were associated with disease recurrence (p = 0.03 and p = 0.006 for 24 and 60 months). Although less significant EGFR status influenced SVLE and SVG. In particular, the presence of EGFR in ER + group affected the evolution tripling relapses and deaths (p = 0.058). The presence of ER-b also had a negative impact on this patient group. In Cox regression analysis, N + and T> 2cm

  15. GW627368X inhibits proliferation and induces apoptosis in cervical cancer by interfering with EP4/EGFR interactive signaling.

    Parida, S; Pal, I; Parekh, A; Thakur, B; Bharti, R; Das, S; Mandal, M

    2016-01-01

    PGE2, the major product of cyclooxygenases implicated in carcinogenesis, is significantly upregulated in cervical cancer. PGE2 via prostanoid receptor EP4 stimulates proliferation and motility while inhibiting apoptosis and immune surveillance. It promotes angiogenesis by stimulating the production of pro-angiogenic factors. The present study demonstrates GW627368X, a highly selective competitive EP4 antagonist, which hinders cervical cancer progression by inhibiting EP4/epithelial growth factor receptor (EGFR) interactive signaling. GW627368X reduced protein kinase A (PKA) phosphorylation which in turn leads to decreased cAMP response element-binding protein (CREB) activation. Decreased PKA phosphorylation also directly enhanced Bax activity and in part reduced glycogen synthase kinase 3 (GSK3)β phosphorylation. Owing to the interactive signaling between EP4 and EGFR, GW627368X lowered EGFR phosphorylation in turn reducing Akt, mitogen-activated protein kinase (MAPK) and GSK3β activity significantly. Sublethal dose of GW627368X was found to reduce the nuclear translocation of β-catenin in a time dependent manner along with time-dependent decrease in cytoplasmic as well as whole-cell β-catenin. Decreased CREB and β-catenin transcriptional activity restricts the aberrant transcription of key genes like EP4, cyclooxygenase (COX)-2, vascular endothelial growth factor and c-myc, which ultimately control cell survival, proliferation and angiogenesis. Reduced activity of EGFR resulted in enhanced expression of 15-hydroxyprostaglandin dehydrogenase increasing PGE2 degradation thereby blocking a positive feedback loop. In xenograft model, dose-dependent decrease in cancer proliferation was observed characterized by reduction in tumor mass and volume and a marked decrease in Ki67 expression. A diminished CD31 specific staining signified decreased tumor angiogenesis. Reduced expression of pAkt, pMAPK, pEGFR and COX-2 validated in vitro results. GW627368X therefore

  16. Multielement determination in soil extracts by instrumental neutron activation analysis

    Forest Swiss soils from 39 locations, each sampled at three depths, were extracted with a buffered solution of pH 4.65 containing EDTA. Nearly 30 elements were determined by instrumental neutron activation analysis. The results obtained are discussed in terms of efficiency of the extractant, precision and accuracy. Summarized results are presented for the quantity fractions of the extracted elements. (author) 18 refs.; 4 figs.; 3 tabs

  17. Determination Of Antioxidant Activities In Freshliver (Salvia Officinalis) Plant

    Arıduru, Rana; Arabacı, Gülnur

    2013-01-01

    In this study, we determined the antioxidant activities of four different solvent fractions (ethanol, methanol, acetone and ethyl acetate) obtained from Freshliver plant leaves (Salvia officinalis) by employing two different assays such as 2,2-diphenyl-1-picrylhydrazyl hydrate (DPPH) and Folin-Ciocaltaeu method. The results showed that ethanolextract of freshliver plant exhibited the highest total phenolic contents (43.55 mg GAE/g extract), followed by methanol-extract of freshliver plant (23...

  18. Cadmium filtered neutron flux determination. Comparison of activation methods

    Neutron fluxes under cadmium filters are determined by the cadmium ratio and sandwich activation methods. The thermal neutron flux levels obtained with 7 detectors of different kinds: In, Au, Ag, W, Co, Mn, Zn are compared. The cadmium ratio method was used in locations for which the epithermal and thermal neutron flux ratio are quite different. By irradiating materials under different thicknesses of cadmium it was possible to establish experimental curves from which the flux depression factors for intermediate neutrons may be determined whatever the thickness of the filter used. Whereas the cadmium ratio method can only measure the mean flux above the cadmium cut-off energy the sandwich method enables the flux value to be determined in a narrow band around the resonance energy of each detector used

  19. Which biomarker predicts benefit from EGFR-TKI treatment for patients with lung cancer?

    Uramoto, H; Mitsudomi, T.

    2007-01-01

    Subsets of patients with non-small cell lung cancer respond remarkably well to small molecule tyrosine kinase inhibitors (TKI) specific for epidermal growth factor receptor (EGFR) such as gefitinib or erlotinib. In 2004, it was found that EGFR mutations occurring in the kinase domain are strongly associated with EGFR-TKI sensitivity. However, subsequent studies revealed that this relationship was not perfect and various predictive markers have been reported. These include EGFR gene copy numbe...

  20. High efficacy of third generation EGFR inhibitor AZD9291 in a leptomeningeal carcinomatosis model with EGFR-mutant lung cancer cells.

    Nanjo, Shigeki; Ebi, Hiromichi; Arai, Sachiko; Takeuchi, Shinji; Yamada, Tadaaki; Mochizuki, Satsuki; Okada, Yasunori; Nakada, Mitsutoshi; Murakami, Takashi; Yano, Seiji

    2016-01-26

    Leptomeningeal carcinomatosis (LMC) remarkably decreases the quality of life of EGFR-mutant lung cancer patients. In contrast to the lesions outside the central nervous system (CNS), molecular mechanisms of EGFR tyrosine kinase inhibitor (TKI) resistance in CNS lesions including LMC are largely unknown. In this study, we established an in vivo imaging model for LMC with EGFR mutant lung cancer cell lines harboring an exon 19 deletion in EGFR and evaluated the effect of first generation EGFR-TKIs, erlotinib, second generation afatinib, and third generation AZD9291. In PC-9/ffluc model, erlotinib treatment slowed the development of LMC. Importantly, treatment with afatinib or AZD9291 apparently delayed the development of LMC. Moreover, treatment with a higher dose of AZD9291, also associated with inhibited phosphorylation of EGFR downstream molecule S6, regressed LMC refractory to the aforementioned EGFR-TKI treatments. These observations suggest that the third generation EGFR-TKI AZD9291 may be an effective treatment for first or second generation EGFR-TKI resistant LMC caused by EGFR-mutant lung cancer. PMID:26716903

  1. Determination of iodine 129 in vegetables using neutron activation analysis

    The developed methodology allows the determination of iodine 129 in vegetables, using neutron activation analysis. The chemical treatment removes the interferences present in these matrixes, as well as the bromine 82 originated in the activation process. The experimental method for the determination of iodine 129 by neutron activation analysis involves five steps: 1- digestion by alkaline fusion; 2- pre-irradiation purification of iodine 129 by distillation followed by solvent extraction, and adsorption on activated charcoal by distillation; 3- neutron irradiation; 4- post-irradiation purification of iodine 130 by distillation followed by solvent extraction; 5- gamma spectrometry. A chemical recovery of 95 % is obtained in the distillations, measured using iodine 131 as tracer. The whole process recovery is within 70 % and 85 %. The detection limit is 2 mBq/kg of sample, but several factors affect this value, such as type of vegetable, natural iodine concentration, irradiation time and neutron flux. The methodology developed is applied at environmental surveillance with safeguards proposes, in the detection of undeclared reprocessing of irradiated fuel. (authors)

  2. Study on palladium determination by neutron activation analysis

    This study presents results of Pd determinations in neutron activation analysis of spiked biological tissues and CCQM-P63 automotive catalyst. Pd spiked biological tissues of bovine muscle and liver were prepared using a blender with titanium blades and Pd solutions. These materials obtained in a past form were freeze-dried and homogenized before the analysis. Thermal and epithermal neutron activation analyses were applied in these determinations. Separations of Pd from interfering elements were also carried out using solvent extraction and solid-phase extraction techniques, before the irradiations with epithermal neutrons. The irradiations were carried out at the IEA-R1 nuclear research reactor under thermal neutron flux of about 4 x 1012 n cm-2 s-1 during 4 and 16 h for thermal and epithermal irradiations, respectively. The gamma activities of 109Pd of the irradiated samples and Pd standard were measured using an HGe detector coupled to a gamma ray spectrometer. Results obtained in these analyses indicated that the epithermal irradiation presented higher sensitivity, due to the reduction of interferences. The pre-separation procedure of solid-phase extraction applied also yielded low detection limit. Comparisons made between the Pd results obtained using different procedures of neutron activation analysis indicated a good agreement. The analyses carried out in replicates also indicated a good precision with relative standard deviations varying from 1.2 to 14 %. (author)

  3. Predictive efficacy of low burden EGFR mutation detected by next-generation sequencing on response to EGFR tyrosine kinase inhibitors in non-small-cell lung carcinoma.

    Hye Sook Kim

    Full Text Available Direct sequencing remains the most widely used method for the detection of epidermal growth factor receptor (EGFR mutations in lung cancer; however, its relatively low sensitivity limits its clinical use. The objective of this study was to investigate the sensitivity of detecting an epidermal growth factor receptor (EGFR mutation from peptide nucleic acid-locked nucleic acid polymerase chain reaction (PNA-LNA PCR clamp and Ion Torrent Personal Genome Machine (PGM techniques compared to that by direct sequencing. Furthermore, the predictive efficacy of EGFR mutations detected by PNA-LNA PCR clamp was evaluated. EGFR mutational status was assessed by direct sequencing, PNA-LNA PCR clamp, and Ion Torrent PGM in 57 patients with non-small cell lung cancer (NSCLC. We evaluated the predictive efficacy of PNA-LNA PCR clamp on the EGFR-TKI treatment in 36 patients with advanced NSCLC retrospectively. Compared to direct sequencing (16/57, 28.1%, PNA-LNA PCR clamp (27/57, 47.4% and Ion Torrent PGM (26/57, 45.6% detected more EGFR mutations. EGFR mutant patients had significantly longer progressive free survival (14.31 vs. 21.61 months, P = 0.003 than that of EGFR wild patients when tested with PNA-LNA PCR clamp. However, no difference in response rate to EGFR TKIs (75.0% vs. 82.4%, P = 0.195 or overall survival (34.39 vs. 44.10 months, P = 0.422 was observed between the EGFR mutations by direct sequencing or PNA-LNA PCR clamp. Our results demonstrate firstly that patients with EGFR mutations were detected more frequently by PNA-LNA PCR clamp and Ion Torrent PGM than those by direct sequencing. EGFR mutations detected by PNA-LNA PCR clamp may be as a predicative factor for EGFR TKI response in patients with NSCLC.

  4. Quantum dot-based quantification revealed differences in subcellular localization of EGFR and E-cadherin between EGFR-TKI sensitive and insensitive cancer cells

    Nanoparticle quantum dots (QDs) provide sharper and more photostable fluorescent signals than organic dyes, allowing quantification of multiple biomarkers simultaneously. In this study, we quantified the expression of epidermal growth factor receptor (EGFR) and E-cadherin (E-cad) in the same cells simultaneously by using secondary antibody-conjugated QDs with two different emission wavelengths (QD605 and QD565) and compared the cellular distribution of EGFR and E-cad between EGFR-tyrosine kinase inhibitor (TKI)-insensitive and -sensitive lung and head and neck cancer cell lines. Relocalization of EGFR and E-cad upon treatment with the EGFR-TKI erlotinib in the presence of EGF was visualized and analyzed quantitatively. Our results showed that QD-immunocytochemistry (ICC)-based technology can not only quantify basal levels of multiple biomarkers but also track the localization of the biomarkers upon biostimulation. With this new technology we found that in EGFR-TKI-insensitive cells, EGFR and E-cad were located mainly in the cytoplasm; while in sensitive cells, they were found mainly on the cell membrane. After induction with EGF, both EGFR and E-cad internalized to the cytoplasm, but the internalization capability in sensitive cells was greater than that in insensitive cells. Quantification also showed that inhibition of EGF-induced EGFR and E-cad internalization by erlotinib in the sensitive cells was stronger than that in the insensitive cells. These studies demonstrate substantial differences between EGFR-TKI-insensitive and -sensitive cancer cells in EGFR and E-cad expression and localization both at the basal level and in response to EGF and erlotinib. QD-based analysis facilitates the understanding of the features of EGFR-TKI-insensitive versus -sensitive cancer cells and may be used in the prediction of patient response to EGFR-targeted therapy.

  5. Antiproliferative effect of growth hormone-releasing hormone (GHRH antagonist on ovarian cancer cells through the EGFR-Akt pathway

    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.

  6. The structural determinants of insulin-like peptide 3 activity

    Ross AD Bathgate

    2012-02-01

    Full Text Available INSL3 is a hormone and/or paracrine factor which is a member of the relaxin peptide family. It has key roles as a fertility regulator in both males and females. The receptor for INSL3 is the leucine rich repeat (LRR containing G-protein coupled receptor 8 (LGR8 which is now known as relaxin family peptide receptor 2 (RXFP2. Receptor activation by INSL3 involves binding to the LRRs in the large ectodomain of RXFP2 by residues within the B-chain of INSL3 as well as an interaction with the transmembrane exoloops of the receptor. Although the binding to the LRRs is well characterized the features of the peptide and receptor involved in the exoloop interaction are currently unknown. This study was designed to determine the key INSL3 determinants for RXFP2 activation. A chimeric peptide approach was first utilized to demonstrate that the A-chain is critical for receptor activation. Replacement of the INSL3 A-chain with that from the related peptides INSL5 and INSL6 resulted in complete loss of activity despite only minor changes in binding affinity. Subsequent replacement of specific A-chain residues with those from the INSL5 peptide highlighted that the N-terminus of the A-chain of INSL3 is critical for its activity. Remarkably, replacement of the entire N-terminus with four or five alanine residues resulted in peptides with near native activity suggesting that specific residues are not necessary for activity. Additionally removal of two amino acids at the C-terminus of the A-chain and mutation of Lys-8 in the B-chain also resulted in minor decreases in peptide activity. Therefore we have demonstrated that the activity of the INSL3 peptide is driven predominantly by residues 5-9 in the A-chain, with minor additional contributions from the two C-terminal A-chain residues and Lys-8 in the B-chain. Using this new knowledge, we were able to produce a truncated INSL3 peptide structure which retained native activity, despite having 14 fewer residues than

  7. Structural Determinants of Clostridium difficile Toxin A Glucosyltransferase Activity

    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.

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

    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

  9. Determination of the specific activity of carrier-free 125I preparations by neutron activation analysis

    Heydorn, Kaj

    Chemical methods are unsuitable for the determination of the specific activity of commerical125I preparations because of the unknown chemical state of the iodine in solutions more than a few weeks old.125I and127I were determined in samples from seven different manufacturers by instrumental neutron...

  10. Regulation of EGFR Protein Stability by the HECT-type Ubiquitin Ligase SMURF2

    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.

  11. Emerging Roles of MicroRNAs in EGFR-Targeted Therapies for Lung Cancer

    Fei Han

    2015-01-01

    Full Text Available Lung cancer is a leading cause of cancer mortality worldwide. Several molecular pathways underlying mechanisms of this disease have been partly elucidated, among which the epidermal growth factor receptor (EGFR pathway is one of the well-known signaling cascades that plays a critical role in tumorigenesis. Dysregulation of the EGFR signaling is frequently found in lung cancer. The strategies to effectively inhibit EGFR signaling pathway have been mounted for developing anticancer therapeutic agents. However, most anti-EGFR-targeted agents fail to repress cancer progression because of developing drug-resistance. Therefore, studies of the mechanisms underpinning the resistance toward anti-EGFR agents may provide important findings for lung cancer treatment using anti-EGFR therapies. Recently, increasing numbers of miRNAs are correlated with the drug resistance of lung cancer cells to anti-EGFR agents, indicating that miRNAs may serve as novel targets and/or promising predictive biomarkers for anti-EGFR therapy. In this paper, we summarize the emerging role of miRNAs as regulators to modulate the EGFR signaling and the resistance of lung cancer cells to anti-EGFR therapy. We also highlight the evidence supporting the use of miRNAs as biomarkers for response to anti-EGFR agents and as novel therapeutic targets to circumvent the resistance of lung cancer cells to EGFR inhibitors.

  12. File list: Oth.Utr.05.EGFR.AllCell [Chip-atlas[Archive

    Full Text Available Oth.Utr.05.EGFR.AllCell hg19 TFs and others EGFR Uterus SRX853214,SRX853217,SRX8532...15,SRX853216 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/Oth.Utr.05.EGFR.AllCell.bed ...

  13. File list: Oth.Utr.20.EGFR.AllCell [Chip-atlas[Archive

    Full Text Available Oth.Utr.20.EGFR.AllCell hg19 TFs and others EGFR Uterus SRX853217,SRX853214,SRX8532...16,SRX853215 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/Oth.Utr.20.EGFR.AllCell.bed ...

  14. File list: Oth.Utr.10.EGFR.AllCell [Chip-atlas[Archive

    Full Text Available Oth.Utr.10.EGFR.AllCell hg19 TFs and others EGFR Uterus SRX853214,SRX853217,SRX8532...16,SRX853215 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/Oth.Utr.10.EGFR.AllCell.bed ...

  15. File list: Oth.Utr.50.EGFR.AllCell [Chip-atlas[Archive

    Full Text Available Oth.Utr.50.EGFR.AllCell hg19 TFs and others EGFR Uterus SRX853217,SRX853215,SRX8532...14,SRX853216 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/Oth.Utr.50.EGFR.AllCell.bed ...

  16. EGFR Signaling in the Brain Is Necessary for Olfactory Learning in "Drosophila" Larvae

    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…

  17. Predictive value of K-ras and PIK3CA in non-small cell lung cancer patients treated with EGFR-TKIs:a systemic review and meta-analysis

    Jie-Ying Chen; Ya-Nan Cheng; Lei Han; Feng Wei; Wen-Wen Yu; Xin-Wei Zhang; Shui Cao; Jin-Pu Yu

    2015-01-01

    Objective:A meta-analysis was performed to augment the insuffcient data on the impact of mutative EGFR downstream phosphatidylinositol-3-kinase (PI3K) and mitogen-activated protein kinase (MAPK) pathways on the clinical effciency of epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) treatment of non-small cell lung cancer (NSCLC) patients. Methods:Network databases were explored in April, 2015. Papers that investigated the clinical outcomes of NSCLC patients treated with EGFR-TKIs according to the status of K-ras and/or PIK3CA gene mutation were included. A quantitative meta-analysis was conducted using standard statistical methods. Odds ratios (ORs) for objective response rate (ORR) and hazard ratios (HRs) for progression-free survival (PFS) and overall survival (OS) were calculated. Results:Mutation in K-ras signiifcantly predicted poor ORR [OR=0.22;95%conifdence interval (CI), 0.13-0.35], shorter PFS (HR=1.56;95%CI, 1.27-1.92), and shorter OS (HR=1.59;95%CI, 1.33-1.91) in NSCLC patients treated with EGFR-TKIs. Mutant PIK3CA signiifcantly predicted shorter OS (HR=1.83;95%CI, 1.05-3.20), showed poor ORR (OR=0.70;95%CI, 0.22-2.18), and shorter PFS (HR=1.79;95%CI, 0.91-3.53) in NSCLC patients treated with EGFR-TKIs. Conclusion:K-ras mutation adversely affected the clinical response and survival of NSCLC patients treated with EGFR-TKIs. PIK3CA mutation showed similar trends. In addition to EGFR, adding K-ras and PIK3CA as routine gene biomarkers in clinical genetic analysis is valuable to optimize the effectiveness of EGFR-TKI regimens and identify optimal patients who will beneift from EGFR-TKI treatment.

  18. Predictive value of K-ras and PIK3CA in non-small cell lung cancer patients treated with EGFR-TKIs: a systemic review and meta-analysis

    Chen, Jie-Ying; Cheng, Ya-Nan; Han, Lei; Wei, Feng; Yu, Wen-Wen; Zhang, Xin-Wei; Cao, Shui; Yu, Jin-Pu

    2015-01-01

    Objective A meta-analysis was performed to augment the insufficient data on the impact of mutative EGFR downstream phosphatidylinositol-3-kinase (PI3K) and mitogen-activated protein kinase (MAPK) pathways on the clinical efficiency of epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) treatment of non-small cell lung cancer (NSCLC) patients. Methods Network databases were explored in April, 2015. Papers that investigated the clinical outcomes of NSCLC patients treated with EGFR-TKIs according to the status of K-ras and/or PIK3CA gene mutation were included. A quantitative meta-analysis was conducted using standard statistical methods. Odds ratios (ORs) for objective response rate (ORR) and hazard ratios (HRs) for progression-free survival (PFS) and overall survival (OS) were calculated. Results Mutation in K-ras significantly predicted poor ORR [OR =0.22; 95% confidence interval (CI), 0.13-0.35], shorter PFS (HR =1.56; 95% CI, 1.27-1.92), and shorter OS (HR =1.59; 95% CI, 1.33-1.91) in NSCLC patients treated with EGFR-TKIs. Mutant PIK3CA significantly predicted shorter OS (HR =1.83; 95% CI, 1.05-3.20), showed poor ORR (OR =0.70; 95% CI, 0.22-2.18), and shorter PFS (HR =1.79; 95% CI, 0.91-3.53) in NSCLC patients treated with EGFR-TKIs. Conclusion K-ras mutation adversely affected the clinical response and survival of NSCLC patients treated with EGFR-TKIs. PIK3CA mutation showed similar trends. In addition to EGFR, adding K-ras and PIK3CA as routine gene biomarkers in clinical genetic analysis is valuable to optimize the effectiveness of EGFR-TKI regimens and identify optimal patients who will benefit from EGFR-TKI treatment. PMID:26175928

  19. Predictive value of K-ras and PIK3CA in non-small cell lung cancer patients treated with EGFR-TKIs: a systemic review and meta-analysis

    A meta-analysis was performed to augment the insufficient data on the impact of mutative EGFR downstream phosphatidylinositol-3-kinase (PI3K) and mitogen-activated protein kinase (MAPK) pathways on the clinical efficiency of epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) treatment of non-small cell lung cancer (NSCLC) patients. Network databases were explored in April, 2015. Papers that investigated the clinical outcomes of NSCLC patients treated with EGFR-TKIs according to the status of K-ras and/or PIK3CA gene mutation were included. A quantitative meta-analysis was conducted using standard statistical methods. Odds ratios (ORs) for objective response rate (ORR) and hazard ratios (HRs) for progression-free survival (PFS) and overall survival (OS) were calculated. Mutation in K-ras significantly predicted poor ORR [OR =0.22; 95% confidence interval (CI), 0.13-0.35], shorter PFS (HR =1.56; 95% CI, 1.27-1.92), and shorter OS (HR =1.59; 95% CI, 1.33-1.91) in NSCLC patients treated with EGFR-TKIs. Mutant PIK3CA significantly predicted shorter OS (HR =1.83; 95% CI, 1.05-3.20), showed poor ORR (OR =0.70; 95% CI, 0.22-2.18), and shorter PFS (HR =1.79; 95% CI, 0.91-3.53) in NSCLC patients treated with EGFR-TKIs. K-ras mutation adversely affected the clinical response and survival of NSCLC patients treated with EGFR-TKIs. PIK3CA mutation showed similar trends. In addition to EGFR, adding K-ras and PIK3CA as routine gene biomarkers in clinical genetic analysis is valuable to optimize the effectiveness of EGFR-TKI regimens and identify optimal patients who will benefit from EGFR-TKI treatment

  20. Method to determine the activity concentration and total activity of radioactive waste

    A characteristic system of radioactive waste is described to determine the concentration of radionuclides activity and the total activity of bundles of radioactive waste. The system this integrated by three subsystems: - Elevator of drums. - Electromechanics. - Gamma spectroscopy. In the system it is analyzed waste of issuing gamma specifically, and this designed for materials of relative low density and it analyzes materials of cylindrical recipients

  1. EGFR-TKI therapy for patients with brain metastases from non-small-cell lung cancer: a pooled analysis of published data

    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

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

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

  3. Antitumor and antiangiogenic effect of the dual EGFR and HER-2 tyrosine kinase inhibitor lapatinib in a lung cancer model

    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). 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. Lapatinib dramatically reduced cell proliferation (P < 0.0001), DNA synthesis (P < 0.006), and colony formation capacity (P < 0.0001) in A549 cells in vitro. Furthermore, lapatinib induced G1 cell cycle arrest (P < 0.0001) and apoptotic cell death (P < 0.0006) and reduced cyclin A and B1 levels, which are regulators of S and G2/M cell cycle stages, respectively. Stimulation of apoptosis in lapatinib-treated A549 cells was correlated with increased cleaved PARP, active caspase-3, and proapoptotic Bak-1 levels, and reduction in the antiapoptic IAP-2 and Bcl-xL protein levels. We also demonstrate that lapatinib altered EGFR/HER-2 signaling pathways reducing p-EGFR, p-HER-2, p-ERK1/2, p-AKT, c-Myc and PCNA levels. In vivo experiments revealed that A549 tumor-bearing mice treated with lapatinib had significantly less active tumors (as assessed by PET analysis) (P < 0.04) and smaller in size than controls. In addition, tumors from lapatinib-treated mice showed a dramatic reduction in angiogenesis (P < 0.0001). Overall, these data suggest that lapatinib

  4. The determination of chromium in water samples by neutron activation analysis after preconcentration on activated carbon

    A method is presented for the determination of chromium in sea- and fresh water. Chromium is concentrated on activated carbon from a neutral solution after a previous reduction of chromate with sodium sulfite at pH 1.5. The adsorption conditions, acidity, concentrations, amount of carbon, stirring-time, sample-volume, salinity, the influence of storage on the ratio of tervalent to hexavalent chromium, were investigated. The final determination of the total chromium content is performed by instrumental neutron-activation analysis. By preconcentration on activated carbon, a differentiation between tervalent and hexavalent chromium is possible. A separate determination of both species is not yet feasible due to the high carbon blank and to the necessity of measuring the adsorption percentage on carbon. The lower limit of determination, which depends on the value of the carbon blank, is 0.05 μg Cr/l with a precision of 20%. The determination is hampered by the considerable blank from the carbon. The use of activated carbon prepared from recrystallized sugar will probably improve the lower limit of determination and possibly allow the determination of chromate. (T.G.)

  5. Determination of phosphodiesterase I activity in human blood serum.

    Hynie, I; Meuffels, M; Poznanski, W J

    1975-09-01

    Phosphodiesterase I (EC 3.1.4.1) activity was detected in normal human blood serum. The enzyme is stable at laboratory temperature for three days, but is inactivated at pH less than 7. The pH for optimum activity increases with the substrate concentration (under the conditions used, from pH 9.0 to 10.2) and, conversely, the Km increases with pH and buffer concentration. The enzyme is inhibited by ethylenediaminetetraacetate but not by phosphate (0.1 mol/liter). We developed a simple quantitative method for its determination, based on hydrolysis of the p-nitrophenyl ester of thymidine 5'-monophosphate and subsequent measurement of the liberated p-nitrophenol at 400 nm in NaOH (0.1 mol/liter). Normal values (mean +/- 2 SD) were determined to be 33 +/- 6.4 U/liter. Preliminary studies indicate that phosphodiesterase I activity is greater than normal in serum of patients with necrotic changes in the liver or kidney or in cases of breast cancer, but not in that of patients with myocardial infarction, bone cancer, lung cancer, or chronic liver cirrhosis. PMID:168991

  6. In vitro determination of the spermicidal activity of plant saponins.

    Primorac, M; Sekulović, D; Antonić, S

    1985-08-01

    The plant kingdom might yield an effective antifertility drug. A Mentha arvensis L. (Labiatae) fraction with uterotonic activity was isolated, and was found to be active on the nonpregnant as well as the pregnant rat uterus. According to folklore medicine, the Mexican plant Montanoa tomentosa Cerv. (zoapatle) possesses antifertility activity in women. The effect of various isolated preparations from this plant on early pregnancy were investigated in serveral rodent species including the mouse, rat hamster, and guinea pig. It was concluded that zoapatle plant extracts possess unique antifertility activity. Lin-Hsim and coworkers isolated fractions from Aristolochia molissima Hanceith contrceptive activity in female mice. Saponins of some plants were used in contraceptive formulations either as foaming agents or as spermicidal substances. Elbary and Nour investigated the spermicidal effects of saponins isolated from the following plants: Gypsophila paniculata L., Saponaria officinalis L., Enterolobium cyclocarpum, Griseb., Terminalia horrida Steud., Melilotus sicula Vitm., and Ruscus hypoglossum L. All of the saponins tested possessed spermicidal activity. Jain and coworkers isolated 2 new saponins in Pittosporum nilghrense with spermicidal effects. In this paper we have determined the spermicidal activity of saponins isolated from some Yugoslav plants, which in that aspect have not been investigated. The results are illustrated in the table. They show that all of the saponins tested were spermicidal in dependence on their nature. Saponins of Primula vulgaris Huds. and Cyclamen persicum Mill. immobilized human spermatozoa within a period of 20 s at a dilution 1:1000. Saponin of Gypsophila paniculata L. was spermicidal at dilution 1:20. These findings show that saponins isolated from some Yugoslav plants may be useful spermicides of natural origin. PMID:4080814

  7. Treatment Choice for Advanced Non-small Cell Lung Cancer Patients Who Had Gradual Progression After EGFR-TKIs: 32 Cases Report

    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.

  8. miRs-134 and -370 function as tumor suppressors in colorectal cancer by independently suppressing EGFR and PI3K signalling

    El-Daly, Sherien M.; Abba, Mohammed L.; Patil, Nitin; Allgayer, Heike

    2016-01-01

    Growth factor receptor signalling plays a central and critical role in colorectal cancer. Most importantly, the EGFR signalling cascade involving PI3K/AKT/mTOR and Raf/MEK/ERK pathways are particularly relevant, since they are commonly activated in several cancer entities, including colorectal cancer. In this study, we show that miRs-134 and -370 are both capable of regulating these pathways by targeting EGFR and PIK3CA. In three different colorectal cancer cell lines (DLD1, HCT-116 and RKO), suppression of EGFR and PIK3CA through the enhanced expression of miR-134 or -370 led to a suppression of the key molecules of the PI3K/AKT/mTOR pathway. Furthermore, overexpression of miR-134 or -370 resulted in a significant reduction of cell proliferation, colony formation, migration, invasion and in-vivo tumor growth and metastasis. Concurrent experiments with small interfering RNAs targeting the prime targets show that our selected miRNAs exert a greater functional influence and affect more downstream molecules than is seen with silencing of the individual proteins. Taken together, these data indicate that miRs-134 and -370 are potential tumour suppressor miRNAs and could play a fundamental role in suppressing colorectal cancer tumorigenesis through their ability to co-ordinately regulate EGFR signalling cascade by independently targeting EGFR and PIK3CA. PMID:27095166

  9. Determination of impurities in zirconium oxide by neutron activation analysis

    The instrumental method of neutron activation analysis was applied to the determination of impurities in zirconium oxide samples produced at IPEN-CNEN/SP. The samples and the standards of the elements to be determined were irradiated in the IEA-R1 research reactor under a thermal neutron flux from 1011 to 1012 n.cm-2.s-1 for a period that varied from 3 min to 8 h and after adequate cooling time they were counted in a Ge(Li) detector coupled to a multichannel analyzer. The impurities of Al, Dy, Eu, Fe, Hf, Mn, Sc, Ta, Tb, Th and V were determined quantitatively in zirconium oxide samples. The relative standard deviations of the results for several impurities were, in general, lower than 15%. In order to investigate the accuracy obtainable with the method a standard reference material Zircaloy 2 - SRM-360a from NIST was analysed. The quantitative determination limit was also evaluated for impurities present in zirconium oxide samples. (author)

  10. The activation method for determining neutron spectra and fluences

    3 mm thick foils of 4 and 17 mm in diameter were used for measurements. NaI scintillation detectors 45 mm in diameter by 50 mm thick and 40 mm in diameter by 1 mm thick, and a Ge-Li spectrometer of 53 cm3 in volume were used for gamma detection. A photopeak or a certain part of the integral spectrum was measured for each radionuclide. Computer code PIKAR was applied in automatic calculation of a simple gamma spectrum obtained using the semiconductor spectrometer. The FACT code was used for calculating foil activity. Codes SAND II and RFSP were used for neutron spectra unfolding. Ge-Li detector spectrometry was used for determining neutron fluence. Code FLUE was used for determining the mean value of neutron flux density and fluence. (J.P.)

  11. Radon determination by activated charcoal adsorption and liquid scintillation measurement

    A passive diffusion method for the determination of radon concentration has been optimised and calibrated. The device consists of a scintillation vial containing activated charcoal, a diffusion barrier and a desiccant agent. The response to diverse atmospheric humidity and variable exposure intervals was studied. The result is a detector, which is independent of atmospheric humidity for at least (up to) 7 days of exposure. The method was compared with electret detectors (US EPA) with very satisfactory results. The advantages of this method are its simplicity, low cost, low detection limit, the total automatization of the measurement and its total independence of humidity to measure in a wide range of radon concentrations. (author)

  12. Determination Of Antioxidant Activities In Freshliver (Salvia Officinalis) Plant

    Rana Arıduru; Gülnur Arabacı

    2013-01-01

    In this study, we determined the antioxidant activities of four different solvent fractions obtained from Freshliver plant leaves (Salvia officinalis) by employing two different assays such as 2,2-diphenyl-1-picrylhydrazyl hydrate (DPPH) and Folin-Ciocaltaeu method. The results showed that ethanol-extract of freshliver plant exhibited the highest total phenolic contents mg GAE/g extract; 43,55, methanol-extract of 23.62, ethyl acetate extract 18.29, and acetone extract 11.58. All the extracti...

  13. 213Bi-anti-EGFR radioimmunoconjugates and X-ray irradiation trigger different cell death pathways in squamous cell carcinoma cells

    Introduction: Treatment of patients with squamous cell carcinoma of head and neck is hampered by resistance of tumor cells to irradiation. Additional therapies enhancing the effect of X-ray irradiation may be beneficial. Antibodies targeting EGFR have been shown to improve the efficacy of radiation therapy. Therefore, we analyzed cytotoxicity of 213Bi-anti-EGFR immunoconjugates in combination with X-ray irradiation. Methods: The monoclonal anti-EGFR antibody matuzumab was coupled to CHX-A”-DTPA forming stable complexes with 213Bi. Cytotoxicity of X-ray radiation, of treatment with 213Bi-anti-EGFR monoclonal antibodies (MAb) or of a combined treatment regimen was assayed using cell proliferation and colony formation assays in UD-SCC5 cells. Key proteins of cell-cycle arrest and cell death were examined by Western blot analysis. Cell cycle analysis was performed by flow cytometry. DNA double-strand breaks were detected via γH2AX and quantified using Definiens™ software. Results: Irradiation with X-rays or treatment with 213Bi-anti-EGFR-MAb resulted in median lethal dose (LD50) values of 12 Gy or 130 kBq/mL, respectively. Treatment with 37 kBq/mL of 213Bi-anti-EGFR-MAb or 2 Gy of X-rays had only little effect on colony formation of UD-SCC5 cells. In contrast, a combined treatment regimen (37 kBq/mL plus 2 Gy) significantly decreased colony formation and enhanced the formation of DNA double-strand breaks. As revealed by flow cytometry, radiation treatments caused accumulation of cells in the G0/G1 phase. Both treatment with 213Bi-anti-EGFR immunoconjugates and application of the combined treatment regimen triggered activation of genes of signaling pathways involved in cell-cycle arrest and induction of apoptosis like p21/Waf, GADD45, Puma and Bax, which were only marginally modulated by X-ray irradiation of cells. Conclusions: 213Bi-anti-EGFR-MAb enhances cytotoxicity of X-ray irradiation in UD-SCC5 cells most probably due to effective induction of DNA double

  14. Proton energy determination using activated yttrium foils and ionization chambers for activity assay

    Avila-Rodriguez, M.A. [Turku PET Centre, University of Turku, Kiinamyllynkatu 4-8, 20520 Turku (Finland); Unidad PET/CT-Ciclotron, Facultad de Medicina, Universidad Nacional Autonoma de Mexico, Edificio de Investigacion P.B, Cd. Universitaria, Circ. Interior, C.P. 04510 Mexico D.F. (Mexico)], E-mail: avilarod@uwalumni.com; Rajander, J.; Lill, J.-O. [Turku PET Centre, Abo Akademi University, Porthansg 3, 20500 Turku (Finland); Gagnon, K. [Edmonton PET Centre, Cross Cancer Institute, 11560 University Ave., Edmonton, AB, T6G 1Z2 (Canada); Schlesinger, J. [Turku PET Centre, University of Turku, Kiinamyllynkatu 4-8, 20520 Turku (Finland); Wilson, J.S.; McQuarrie, S.A. [Edmonton PET Centre, Cross Cancer Institute, 11560 University Ave., Edmonton, AB, T6G 1Z2 (Canada); Solin, O. [Turku PET Centre, University of Turku, Kiinamyllynkatu 4-8, 20520 Turku (Finland)

    2009-05-15

    Excitation functions of the {sup 89}Y(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 {sup 89}Zr 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 {sup 89g}Zr/{sup 88}Zr and {sup 89g}Zr/{sup 88}Y activity ratios measured via gamma spectroscopy.

  15. EGFR-Ras-Raf Signaling in Epidermal Stem Cells: Roles in Hair Follicle Development, Regeneration, Tissue Remodeling and Epidermal Cancers

    Manuela Baccarini; Christian Rupp; Eszter Doma

    2013-01-01

    The mammalian skin is the largest organ of the body and its outermost layer, the epidermis, undergoes dynamic lifetime renewal through the activity of somatic stem cell populations. The EGFR-Ras-Raf pathway has a well-described role in skin development and tumor formation. While research mainly focuses on its role in cutaneous tumor initiation and maintenance, much less is known about Ras signaling in the epidermal stem cells, which are the main targets of skin carcinogenesis. In this review,...

  16. Determination of mutually interfering elements in activation analysis

    The determination of the elements present in the groups scandium-zinc, mercury-selenium and arsenic-antimony-bromine represents a classical problem in thermal neutron activation analysis because the gamma-ray peaks of the radioisotopes produced from these elements by activation appear very close in the spectrum. A study is made of the possibility of simultaneous instrumental determination of these elements by means of the spectrum stripping technique, using a 400-channel analyser coupled to a Nal(Tl) detector and a 4096-channel analyser coupled to a Ge(Li) detector. Artificial mixtures of the interfering elements in varying proportions are prepared, so as to reproduce possible real samples, where the elements may be present at several concentrations. Radiochemical separation techniques for the cited elements are studied with the use of tracers. For the separation of scadium and zinc, the technique of extraction chromatography is applied. The separation of mercury and selenium is accomplished by means of ion exchange. The technique of coprecipitation is used to separate bromine from arsenic and antimony followed by ion exchange to isolate these two elements from each other. The precision and the accuracy of the results are discussed. (Author)

  17. Determination of the sanguine iodine content by activation analysis (1962)

    Two methods of measuring the iodine content of the blood by activation analysis after 30 min irradiation in a flux of 6.1012 n/cm2.s are described. One method includes a chemical separation of iodine before irradiation. The radioactivity of this specimen is determined on the basis of the amplitude of the iodine 128 photoelectric peak measured by γ-spectrometry. The sensitivity of this method is about 10-8 g. The other includes chemical separation after irradiation, and radioactivity is subsequently measured with a Geiger-Muller counter. The sensitivity of this second method is about 10-10 g, sufficient for determination of the plasmatic mineral content. The advantages of activation analysis over the conventional method based on colorimetric measurement of the catalytic action of iodine in the oxidation of arsenious anhydride with ceric sulphate are discussed. Initial results obtained with this new form of analysis are detailed as are also the possibilities of measuring plasmatic proteic iodine by scintillation spectrometry without prior chemical separation. (authors)

  18. EGFR and HER2 expression in advanced biliary tract cancer

    Jan Harder; Oliver Waiz; Florian Otto; Michael Geissler; Manfred Olschewski; Brigitte Weinhold; Hubert E Blum; Annette Schmitt-Graeff; Oliver G Opitz

    2009-01-01

    AIM: To analyze the pathogenetic role and potential clinical usefulness of the epidermal growth factor receptor (EGFR) and the human epidermal growth factor receptor 2 (HER2) in patients with advanced biliary tract cancer (BTC). METHODS: EGFR and HER2 expression was studied in biopsy samples from 124 patients (51% women;median age 64.8 years), with advanced BTC diagnosed between 1997 and 2004. Five micrometers sections of paraffin embedded tissue were examined by standard, FDA approved immunohistochemistry. Tumors with scores of 2+ or 3+ for HER2 expression on immunochemistry were additionally tested for HER2 gene amplification by fluorescence in situ hybridisation (FISH).RESULTS: 34/124 patients (27.4%) had gallbladder cancer, 47 (37.9%) had intrahepatic BTC and 43 (34.7%) had extrahepatic or perihilar BTC. EGFR expression was examined in a subset of 56 samples. EGFR expression was absent in 22/56 tumors (39.3%).Of the remaining samples expression was scored as 1+ in 12 (21.5%), 2+ in 13 (23.2%) and 3+ in 9 (16%), respectively. HER2 expression was as follows: score 0 73/124 (58.8%), score 1+ 27/124 (21.8%), score 2+ 21/124 (17%) and score 3+ 4/124 (3.2%). HER2 gene amplification was present in 6/124, resulting in an overall amplification rate of 5%.CONCLUSION: Our data suggest that routine testing and therapeutic targeting of HER2 does not seem to be useful in patients with BTC, while targeting EGFR may be promising.

  19. Dual targeting of EGFR and focal adhesion kinase in 3D grown HNSCC cell cultures

    Purpose: Epidermal growth factor receptor (EGFR) and focal adhesion kinase (FAK) show frequent overexpression and hyperactivity in various human malignancies including head and neck squamous cell carcinomas (HNSCC). To examine effects of dual EGFR/FAK inhibition on cellular radiosensitivity of HNSCC cells in a more physiological environment, we employed a previously established laminin-rich extracellular matrix (lrECM) based three-dimensional (3D) cell culture model. Materials and methods: UTSCC15 and SAS HNSCC cell lines stably transfected with EGFR-CFP or CFP were used. Single or combined EGFR (Cetuximab, siRNA) and FAK (TAE226, siRNA) inhibition were accomplished prior to measuring clonogenic survival and protein expression and phosphorylation. Immunofluorescence enabled visualization of EGFR-CFP and FAK. Results: Cetuximab resulted in higher radiosensitization in EGFR-CFP overexpressing cell lines than CFP controls. Single EGFR or FAK inhibition mediated radiosensitization, while dual EGFR/FAK targeting further augmented this effect. Despite signaling alterations upon Cetuximab and siRNA knockdown, analysis of protein expression and phosphorylation indicates EGFR and FAK signaling coexistence without obvious overlap. Conclusions: Combined EGFR/FAK targeting yielded stronger radiosensitization than either approach alone, which might be based on non-overlapping downstream signaling. Whether dual targeting of EGFR and FAK can reasonably be combined with radiotherapy and chemotherapy needs clarification.

  20. EGFR FISH analysis in colorectal cancer as a tool in selecting patients for antiEGFR monoclonal antibodies therapy

    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.

  1. Alpha-particle emitting 213Bi-anti-EGFR immunoconjugates eradicate tumor cells independent of oxygenation.

    Christian Wulbrand

    Full Text Available Hypoxia is a central problem in tumor treatment because hypoxic cells are less sensitive to chemo- and radiotherapy than normoxic cells. Radioresistance of hypoxic tumor cells is due to reduced sensitivity towards low Linear Energy Transfer (LET radiation. High LET α-emitters are thought to eradicate tumor cells independent of cellular oxygenation. Therefore, the aim of this study was to demonstrate that cell-bound α-particle emitting (213Bi immunoconjugates kill hypoxic and normoxic CAL33 tumor cells with identical efficiency. For that purpose CAL33 cells were incubated with (213Bi-anti-EGFR-MAb or irradiated with photons with a nominal energy of 6 MeV both under hypoxic and normoxic conditions. Oxygenation of cells was checked via the hypoxia-associated marker HIF-1α. Survival of cells was analysed using the clonogenic assay. Cell viability was monitored with the WST colorimetric assay. Results were evaluated statistically using a t-test and a Generalized Linear Mixed Model (GLMM. Survival and viability of CAL33 cells decreased both after incubation with increasing (213Bi-anti-EGFR-MAb activity concentrations (9.25 kBq/ml-1.48 MBq/ml and irradiation with increasing doses of photons (0.5-12 Gy. Following photon irradiation survival and viability of normoxic cells were significantly lower than those of hypoxic cells at all doses analysed. In contrast, cell death induced by (213Bi-anti-EGFR-MAb turned out to be independent of cellular oxygenation. These results demonstrate that α-particle emitting (213Bi-immunoconjugates eradicate hypoxic tumor cells as effective as normoxic cells. Therefore, (213Bi-radioimmunotherapy seems to be an appropriate strategy for treatment of hypoxic tumors.

  2. EGFR-directed Affibody for fluorescence-guided glioma surgery: time-dose analysis (Conference Presentation)

    Ribeiro de Souza, Ana Luiza; Marra, Kayla; Gunn, Jason R.; Elliott, Jonathan T.; Samkoe, Kimberley S.; Paulsen, Keith D.; Draney, Daniel R.; Feldwisch, Joachim

    2016-03-01

    The key to fluorescence guided surgical oncology is the ability to create specific contrast between normal and glioma tissue. The blood brain barrier that limits the delivery of substances to the normal brain is broken in tumors, allowing accumulation of agents in the tumor interior. However, for a clinical success, imaging agents should be in the infiltrative edges to minimize the resection of normal brain while enable the removal of tumor. The aberrant overexpression and/or activation of EGFR is associated with many types of cancers, including glioblastoma and the injection of a fluorescent molecule targeted to these receptors would improve tumor contrast during fluorescence guided surgery. Affibody molecules have intentional medium affinity and high potential specificity, which are the desirable features of a good surgical imaging agent. The aim of this study was evaluate the brain/glioma uptake of ABY029 labeled with near-infrared dye IRDye800CW after intravenous injection. Rats were either inoculated with orthotopic implantations of U251 human glioma cell line or PBS (shams control) in the brain. The tumors were allowed to grow for 2-3 weeks before carrying out fluorescent tracer experiments. Fluorescent imaging of ex vivo brain slices from rats was acquired at different time points after infection of fluorescently labeled EGFR-specific affibody to verify which time provided maximal contrast tumor to normal brain. Although the tumor was most clearly visualized after 1h of IRDye800CW-labeled ABY029 injection, the tumor location could be identified from the background after 48h. These results suggest that the NIR-labeled affibody examined shows excellent potential to increase surgical visualization for confirmed EGFR positive tumors.

  3. A gasometric method to determine erythrocyte catalase activity

    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.

  4. p85α promotes nucleolin transcription and subsequently enhances EGFR mRNA stability and EGF-induced malignant cellular transformation

    Gu, Jiayan; Zhang, Liping; Jin, Honglei; Huang, Haishan; Li, Jingxia; Huang, Chuanshu

    2016-01-01

    p85α is a regulatory subunit of phosphatidylinositol 3-kinase (PI3K) that is a key lipid enzyme for generating phosphatidylinositol 3, 4, 5-trisphosphate, and subsequently activates signaling that ultimately regulates cell cycle progression, cell growth, cytoskeletal changes, and cell migration. In addition to form a complex with the p110 catalytic subunit, p85α also exists as a monomeric form due to that there is a greater abundance of p85α than p110 in many cell types. Our previous studies have demonstrated that monomeric p85α exerts a pro-apoptotic role in UV response through induction of TNF-α gene expression in PI3K-independent manner. In current studies, we identified a novel biological function of p85α as a positive regulator of epidermal growth factor receptor (EGFR) expression and cell malignant transformation via nucleolin-dependent mechanism. Our results showed that p85α was crucial for EGFR and nucleolin expression and subsequently resulted in an increase of malignant cellular transformation by using both specific knockdown and deletion of p85α in its normal expressed cells. Mechanistic studies revealed that p85α upregulated EGFR protein expression mainly through stabilizing its mRNA, whereas nucleolin (NCL) was able to bind to egfr mRNA and increase its mRNA stability. Consistently, overexpression of NCL in p85α−/− cells restored EGFR mRNA stabilization, protein expression and cell malignant transformation. Moreover, we discovered that p85α upregulated NCL gene transcription via enhancing C-Jun activation. Collectively, our studies demonstrate a novel function of p85α as a positive regulator of EGFR mRNA stability and cell malignant transformation, providing a significant insight into the understanding of biomedical nature of p85α protein in mammalian cells and further supporting that p85α might be a potential target for cancer prevention and therapy. PMID:26918608

  5. p85α promotes nucleolin transcription and subsequently enhances EGFR mRNA stability and EGF-induced malignant cellular transformation.

    Xie, Qipeng; Guo, Xirui; Gu, Jiayan; Zhang, Liping; Jin, Honglei; Huang, Haishan; Li, Jingxia; Huang, Chuanshu

    2016-03-29

    p85α is a regulatory subunit of phosphatidylinositol 3-kinase (PI3K) that is a key lipid enzyme for generating phosphatidylinositol 3, 4, 5-trisphosphate, and subsequently activates signaling that ultimately regulates cell cycle progression, cell growth, cytoskeletal changes, and cell migration. In addition to form a complex with the p110 catalytic subunit, p85α also exists as a monomeric form due to that there is a greater abundance of p85α than p110 in many cell types. Our previous studies have demonstrated that monomeric p85α exerts a pro-apoptotic role in UV response through induction of TNF-α gene expression in PI3K-independent manner. In current studies, we identified a novel biological function of p85α as a positive regulator of epidermal growth factor receptor (EGFR) expression and cell malignant transformation via nucleolin-dependent mechanism. Our results showed that p85α was crucial for EGFR and nucleolin expression and subsequently resulted in an increase of malignant cellular transformation by using both specific knockdown and deletion of p85α in its normal expressed cells. Mechanistic studies revealed that p85α upregulated EGFR protein expression mainly through stabilizing its mRNA, whereas nucleolin (NCL) was able to bind to egfr mRNA and increase its mRNA stability. Consistently, overexpression of NCL in p85α-/- cells restored EGFR mRNA stabilization, protein expression and cell malignant transformation. Moreover, we discovered that p85α upregulated NCL gene transcription via enhancing C-Jun activation. Collectively, our studies demonstrate a novel function of p85α as a positive regulator of EGFR mRNA stability and cell malignant transformation, providing a significant insight into the understanding of biomedical nature of p85α protein in mammalian cells and further supporting that p85α might be a potential target for cancer prevention and therapy. PMID:26918608

  6. Suppression of microRNA-125a-5p upregulates the TAZ-EGFR signaling pathway and promotes retinoblastoma proliferation.

    Zhang, Yiting; Xue, Chunyan; Zhu, Xiaomin; Zhu, Xinyue; Xian, Hongyu; Huang, Zhenping

    2016-08-01

    Retinoblastoma is the most common intraocular malignancy that occurs during childhood; however, the mechanism underlying retinoblastoma proliferation and progression remains unclear. MicroRNAs (miRNAs) play an important role in the regulation of a myriad of biological processes in various types of cancer. In this study, we performed microarray analysis followed by qRT-PCR using four classes of retinoblastoma tissues with increasing cTNM classification stages to identify crucial miRNAs whose expression was correlated with retinoblastoma progression. miR-125a-5p was downregulated, and its expression levels were inversely correlated with cell proliferation in retinoblastoma compared with adjacent non-tumor retinal tissues. The overexpression of miR-125a-5p significantly suppressed cell proliferation and tumor formation in retinoblastoma. We further identified the transcriptional co-activator with PDZ binding motif (TAZ) as a direct target of miR-125a-5p. Importantly, TAZ levels were inversely correlated with miRNA-125a-5p expression, and TAZ promoted retinoblastoma cell proliferation. Moreover, the overexpression of miR-125a-5p led to a decrease in TAZ expression and downstream EGFR signaling pathway activation both in vitro and vivo. Finally, TAZ overexpression in retinoblastoma cells overexpressing miR-125a-5p restored retinoblastoma cell proliferation and EGFR pathway activation. Taken together, our data demonstrated that miR-125a-5p functions as an important tumor suppressor that suppresses the EGFR pathway by targeting TAZ to inhibit tumor progression in retinoblastoma. Thus, the miR-125a-5p/TAZ/EGFR axis may be a potential therapeutic target for retinoblastoma. PMID:27094723

  7. A novel epidermal growth factor receptor variant lacking multiple domains directly activates transcription and is overexpressed in tumors

    Piccione, EC; Lieu, TJ; Gentile, CF; Williams, TR; Connolly, AJ; Godwin, AK; Koong, AC; Wong, AJ

    2011-01-01

    The epidermal growth factor receptor (EGFR) is essential to multiple physiological and neoplastic processes via signaling by its tyrosine kinase domain and subsequent activation of transcription factors. EGFR overexpression and alteration, including point mutations and structural variants, contribute to oncogenesis in many tumor types. In this study, we identified an in-frame splice variant of the EGFR called mini-LEEK (mLEEK) that is more broadly expressed than the EGFR and is overexpressed ...

  8. The instrumental neutron activation determination of impurities in technical cobalt

    Instrumental neutron activation techniques for determination of 13 impurities with detection limit 10-5 - 10-2% in technical cobalt have been developed by using thermal and epithermal neutrons of nuclear reactor. Self-shielding and disturbance of neutron flux(Co59 has high capture cross-section of neutrons) by sample were taken into account by using some references and from the results obtained in preliminary experiments. Samples and standards have been placed in such a way that neutron flux disturbance was less than 2-3%. The Al-Pb-Cd-Cu filter was used for absorption of low energy γ-rays of Co60m and Co61. (author)

  9. Neutron activation determination of impurities in molybdenite and galena

    A method is described for non-destructive neutron-activation determination of 14 chemical elements (Na, Ag, Zn, Sc, La, Eu, Tb, Yb, Sb, Ta, Gr, Se, Fe and Co) in molybdenite and galenite minerals. The samples and standards of Ag, Se, Co and Np have been wrapped in an aluminium foil and packed in an aluminium container; they have been then irradiated for 10 hr in the vertical channel of a nuclear reactor with flux of thermal neutrons (3.0, 0.45)x1013 n/cm2xsec to record the γ-spectra of the samples and standards 1, 5, 16, 65, 265 and 350 days after irradiation on a γ-spectrometer with a Ge(Li)-detector. The results are found to be in a good agreement with the spectra of Ag, Sb, La and Fe

  10. Determination of active oxygen content in rare earth peroxides

    The content of active oxygen in rare earth peroxides have been determined after the dissolution of the samples with hydrocloridic acid in the presence of potassium iodide. The free generated iodine is titrated with sodium thiosulfate using starch as indicator. The oxidation of iodide to the free iodine indicates the presence of a higher valence state rare earth oxide, until now specifically recognized for the oxides of cerium (Ce O2), praseodymium (Pr6 O11) and terbium (TB4 O7). recently the authors synthesized a new series of rare earth compounds, the peroxides. These new compounds were prepared by precipitating the rare earth elements complexed with carbonate ion by addition of hydrogen peroxide. the authors demonstrated that all rare earth elements, once solubilized by complexing with carbonate ion, are quantitatively precipitated as peroxide by addition of hydrogen peroxide. (author)

  11. Determinants of uptake and maintenance of active commuting to school.

    Murtagh, Elaine M; Dempster, Martin; Murphy, Marie H

    2016-07-01

    The objective was to identify determinants of uptake and maintenance of active school travel (AST) over 4 years in children aged 9 at baseline. Data from wave 1 (n=8502) and 2 (n=7479) of the Growing Up in Ireland study were analysed. At 9- and 13-years 25% and 20% engaged in AST. Children were more likely to maintain or take-up AST if they lived in an urban area. Change in distance to school influenced both maintenance and adoption of AST, with a negative impact seen for increased distance between 9 and 13 years and a positive impact seen for decreased distance. Some factors which predict uptake and maintenance of AST are modifiable and can inform intervention development. PMID:27160529

  12. The prevalence of EGFR mutations in non-small cell lung cancer in an unselected Caucasian population

    Skov, Birgit G; Høgdall, Estrid; Clementsen, Paul;

    2015-01-01

    in a well-defined Danish population were included. The type of the diagnostic material, and data on smoking were registered. The mutation analyses were investigated by Therascreen EGFR RGQ-PCR Kit or Sanger sequencing. A total of 658 men and 598 women were included. 6.2% were never smokers, 38.......9% were ex-smokers, and 54.9% were current smokers. One thousand one hundred and sixty-one (92.4%) patients had sufficient material for mutation analysis. Cytological material was used for 38% of the mutation analyses. 5.4% had mutation in the EGFR gene (4.3% men/6.7% women). 87% were activating mutations...

  13. EGFR-Ras-Raf Signaling in Epidermal Stem Cells: Roles in Hair Follicle Development, Regeneration, Tissue Remodeling and Epidermal Cancers

    Manuela Baccarini

    2013-09-01

    Full Text Available The mammalian skin is the largest organ of the body and its outermost layer, the epidermis, undergoes dynamic lifetime renewal through the activity of somatic stem cell populations. The EGFR-Ras-Raf pathway has a well-described role in skin development and tumor formation. While research mainly focuses on its role in cutaneous tumor initiation and maintenance, much less is known about Ras signaling in the epidermal stem cells, which are the main targets of skin carcinogenesis. In this review, we briefly discuss the properties of the epidermal stem cells and review the role of EGFR-Ras-Raf signaling in keratinocyte stem cells during homeostatic and pathological conditions.

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

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

  15. Determination of actinides in samples obtained during dismantling activities

    At present, some of the nuclear and radioactive facilities from CIEMAT employed in the past to perform activities related to the production of nuclear energy have been decommissioned as part of a more global on-going dismantling project. During the radiological characterization of a former laboratory a significant contamination of actinide elements in the old liquid effluents system was found. Samples obtained from two different locations (pipes and deposit) were measured by gamma- and alpha-spectrometry to quantify the contamination of the system. A quick and simple method using Actinide resin coupled with liquid scintillation counting (LSC) was employed for the determination of gross-alpha activity. The samples were also analyzed using a sequential leaching procedure to obtain information about the actinide association to certain geochemical phases with different solubilities such as carbonates, oxides, organic matter, etc., and thus, to choose the most appropriate clean-up method. Finally, the results obtained by the different techniques mentioned are compared and discussed. (author)

  16. Coexpression of EGFR and CXCR4 predicts poor prognosis in resected pancreatic ductal adenocarcinoma.

    Huanwen Wu

    Full Text Available Epidermal growth factor receptor (EGFR is highly expressed in pancreatic ductal adenocarcinoma (PDAC and is involved in tumorigenesis and development. However, EGFR expression alone has limited clinical and prognostic significance. Recently, the cross-talk between EGFR and G-protein-coupled chemokine receptor CXCR4 has become increasingly recognized.In the present study, immunohistochemical staining of EGFR and CXCR4 was performed on paraffin-embedded specimens from 131 patients with surgically resected PDAC. Subsequently, the associations between EGFR expression, CXCR4 expression, EGFR/CXCR4 coexpression and clinicopathologic factors were assessed, and survival analyses were performed.In total, 64 (48.9% patients expressed EGFR, 68 (51.9% expressed CXCR4, and 33 (25.2% coexpressed EGFR and CXCR4. No significant association between EGFR and CXCR4 expression was observed (P = 0.938. EGFR expression significantly correlated with tumor differentiation (P = 0.031, whereas CXCR4 expression significantly correlated with lymph node metastasis (P = 0.001. EGFR/CXCR4 coexpression was significantly associated with lymph node metastasis (P = 0.026, TNM stage (P = 0.048, and poor tumor differentiation (P = 0.004. By univariate survival analysis, both CXCR4 expression and EGFR/CXCR4 coexpression were significant prognostic factors for poor disease-free survival (DFS and overall survival (OS. Moreover, EGFR/CXCR4 coexpression significantly increased the hazard ratio for both recurrence and death compared with EGFR or CXCR4 protein expression alone. Multivariate survival analysis demonstrated that EGFR/CXCR4 coexpression was an independent prognostic factor for DFS (HR = 2.33, P<0.001 and OS (HR = 2.48, P = 0.001.In conclusion, our data indicate that although EGFR expression alone has limited clinical and prognostic significance, EGFR/CXCR4 coexpression identified a subset of PDAC patients with more aggressive tumor characteristics and a significantly worse

  17. Role of EGFR mutations in lung cancers: prognosis and tumor chemosensitivity.

    Suda, Kenichi; Mitsudomi, Tetsuya

    2015-08-01

    Lung cancers with an epidermal growth factor receptor (EGFR) gene mutation account for ~40 % of adenocarcinomas in East Asians and ~15 % of those in Caucasians and African Americans, which makes them one of the most common molecularly defined lung cancer subsets. The discriminative clinical and pathological features of lung cancers with EGFR mutations have been intensively studied, and the predictive role of an EGFR mutation for treatment with EGFR tyrosine kinase inhibitors (EGFR-TKIs) is well established. However, controversial issues remain regarding the clinical and therapeutic implications of EGFR mutations in lung cancers. These include the prognostic impact of the EGFR mutation, its predictive implication for successful treatment with anticancer agents other than EGFR-TKIs, appropriate cytotoxic agents for lung cancers with this mutation, and the chemosensitivity of EGFR-mutation-positive lung cancers after acquisition of resistance to EGFR-TKIs. In this review, we discuss these unanswered but important questions, referring to in vitro studies, basic research, retrospective analyses, and the results of phase III clinical trials. PMID:25983263

  18. Assessment of EGFR mutation status in lung adenocarcinoma by immunohistochemistry using antibodies specific to the two major forms of mutant EGFR.

    Brevet, Marie; Arcila, Maria; Ladanyi, Marc

    2010-03-01

    EGFR mutations are the best predictors of response to EGFR kinase inhibitors in lung adenocarcinoma. We evaluated two mutation-specific monoclonal antibodies for the detection of EGFR mutations by immunohistochemistry (IHC), generated respectively against the L858R mutant and the exon 19 mutant with the common 15bp/5AA deletion. These two mutations account for approximately 90% of all EGFR mutations. IHC staining performed on 218 paraffin-embedded lung adenocarcinomas was assessed on a 0 to 3+ scale, and positivity cutoffs of 1+ and 2+ were compared. All cases were studied by standard molecular methods for these two mutations, and selected cases were also studied using higher sensitivity molecular assays. The EGFR L858R mutant antibody showed a sensitivity of 95% and a positive predictive value (PPV) of 99% with a positivity cutoff of 1+ and a sensitivity of 76% and a PPV of 100% with a positivity cutoff of 2+. The EGFR exon 19 mutant-specific antibody showed reduced sensitivity for exon 19 deletions other than 15bp. A positivity cutoff of 1+ resulted in a sensitivity of 85% and a PPV of 99%, whereas a 2+ cutoff gave a sensitivity of 67% and a PPV of 100%. IHC with EGFR mutant-specific antibodies could be used as a screen to identify most candidates for EGFR inhibitors. PMID:20093391

  19. Analysis of EGFR signaling pathway in nasopharyngeal carcinoma cells by quantitative phosphoproteomics

    He Qiu-Yan

    2011-06-01

    Full Text Available Abstract Background The epidermal growth factor receptor (EGFR is usually overexpressed in nasopharyngeal carcinoma (NPC and is associated with pathogenesis of NPC. However, the downstream signaling proteins of EGFR in NPC have not yet been completely understood at the system level. The aim of this study was identify novel downstream proteins of EGFR signaling pathway in NPC cells. Results We analyzed EGFR-regulated phosphoproteome in NPC CNE2 cells using 2D-DIGE and mass spectrometry analysis after phosphoprotein enrichment. As a result, 33 nonredundant phosphoproteins including five known EGFR-regulated proteins and twenty-eight novel EGFR-regulated proteins in CNE2 were identified, three differential phosphoproteins were selectively validated, and two differential phosphoproteins (GSTP1 and GRB2 were showed interacted with phospho-EGFR. Bioinformatics analysis showed that 32 of 33 identified proteins contain phosphorylation modification sites, and 17 identified proteins are signaling proteins. GSTP1, one of the EGFR-regulated proteins, associated with chemoresistance was analyzed. The results showed that GSTP1 could contribute to paclitaxel resistance in EGF-stimulated CNE2 cells. Furthermore, an EGFR signaling network based on the identified EGFR-regulated phosphoproteins were constructed using Pathway Studio 5.0 software, which includes canonical and novel EGFR-regulated proteins and implicates the possible biological roles for those proteins. Conclusion The data not only can extend our knowledge of canonical EGFR signaling, but also will be useful to understand the molecular mechanisms of EGFR in NPC pathogenesis and search therapeutic targets for NPC.

  20. Alpha1a-Adrenoceptor Genetic Variant Triggers Vascular Smooth Muscle Cell Hyperproliferation and Agonist Induced Hypertrophy via EGFR Transactivation Pathway.

    Irina Gradinaru

    Full Text Available α1a Adrenergic receptors (α1aARs are the predominant AR subtype in human vascular smooth muscle cells (SMCs. α1aARs in resistance vessels are crucial in the control of blood pressure, yet the impact of naturally occurring human α1aAR genetic variants in cardiovascular disorders remains poorly understood. To this end, we present novel findings demonstrating that 3D cultures of vascular SMCs expressing human α1aAR-247R (247R genetic variant demonstrate significantly increased SMC contractility compared with cells expressing the α1aAR-WT (WT receptor. Stable expression of 247R genetic variant also triggers MMP/EGFR-transactivation dependent serum- and agonist-independent (constitutive hyperproliferation and agonist-dependent hypertrophy of SMCs. Agonist stimulation reduces contractility Using pathway-specific inhibitors we determined that the observed hyperproliferation of 247R-expressing cells is triggered via β-arrestin1/Src/MMP-2/EGFR/ERK-dependent mechanism. MMP-2-specific siRNA inhibited 247R-triggered hyperproliferation indicating MMP-2 involvement in 247R-triggered hyperproliferation in SMCs. β-arrestin1-specific shRNA also inhibited 247R-triggered hyperproliferation but did not affect hypertrophy in 247R-expressing SMCs, indicating that agonist-dependent hypertrophy is independent of β-arrestin1. Our data reveal that in different cardiovascular cells the same human receptor genetic variant can activate alternative modulators of the same signaling pathway. Thus, our findings in SMCs demonstrate that depending on the type of cells expressing the same receptor (or receptor variant, different target-specific inhibitors could be used to modulate aberrant hyperproliferative or hypertrophic pathways in order to restore normal phenotype.

  1. Human pharmacokinetics, biodistribution and dosimetry of the kit of monoclonal antibody IOR EGF/R3 labelled with {sup 99m} Tc

    Torres, L.A.; Ramos, M.; Perera, A.; Hernandez, A.; Iznaga, M.E. N. [Solano, Ivette Alvarez, Jose L. Rodriguez. Centro de InvestigacionesClinicas. 34 no.4501 e/45 y 47 Kohly, Playa, C. Habana (Cuba)

    1998-12-31

    The aim of this work was to assess the human pharmacokinetics, biodistribution and dosimetry of the {sup 99m} Tc-labeled MAb ior egf/r3. Five patients were included in the biodistribution and dosimetric studies and three in the pharmacokinetic analysis. Multiple blood and urine samples we recollected and sequential anterior and posterior whole-body scintigraphies u pto 24 hr post-injection were performed to all patients . The internal radiation dosimetry was estimated from gamma camera imaging data using the methods developed by the Medical Internal radiation dosimetry (MIRD)committee. Raw data were computed from operations between gamma graphic images and regions of interest (ROI) using the Bio-Dose software and time-activity curves were calculated in order to determine the residence times of the source organs. The Pharmacokinetics and Biodistribution results showed that this compound have a bio exponential plasmatic and blood clearance with a rapid biodistribution phase of 9.1 {+-} 8.4 min and 12.2{+-}4.4 min, respectively, and a slower elimination phase of 6.6 {+-} 1.6 hr and 10.8 {+-} 6.8 hr. respectively. The urinary and hepatobiliary excretion showed 4.7 {+-} 0.4 % and 9.9 {+-} 1.8 % of the total administered dose,eliminated by these ways. Liver was the target organ of this product and had an uptake peak at 1 hr post-injection (61.2%) and a great retention of the MAb(T 1/2 eff = 5.3 hr, T 1/2 Biol. = 45.0 hr). The dosimetric results showed that liver, gallbladder and spleen received the higher absorbed. The effective dose and the effective equivalent dose were 1,2E-01 mSv/MBq and 9,2E-02 mSv/MBq respectively. These results allow to see the i or egf/r3 kit in a safe and controlled way. (Author)

  2. Reduction in Estimated Glomerular Filtration Rate (eGFR) Results in an Increased Risk of Spontaneous Hemorrhagic Transformation in Patients with Large-artery Atherosclerosis Stroke.

    Liu, Bian; Wang, Deren; Hao, Zilong; Li, Dan; Zhang, Junhuai; Liu, Junfeng; Liu, Ming

    2016-01-01

    The association between chronic kidney disease and spontaneous hemorrhagic transformation (HT) in patients with acute ischemic stroke is seldom reported. We performed this study to identify whether reduced estimated glomerular filtration rate (eGFR) is associated with spontaneous HT in acute ischemic stroke patients, and examine whether the association depends on stroke etiology. Patients diagnosed with acute ischemic stroke whose serum creatinine levels at admission were available were consecutively and prospectively enrolled in the Chengdu Stroke Registry Database. All were analyzed on admission by cranial computed tomography (CT) scanning, followed by regular magnetic resonance imaging (MRI) 2-3 days later and afterwards CT scan if neurological symptoms deteriorated. HT was defined based on the MRI or later CT, and eGFR was calculated using the Modification of Diet in Renal Disease equation. Univariate analysis and multivariable logistic regression were performed to determine whether reduced eGFR, defined as < 60 ml/min/1.73m2, was associated with spontaneous HT. The association was also assessed in subgroups of patients classified according to the criteria of the Trial of Org 10172 in Acute Stroke Treatment (TOAST). Of the 1,645 patients enrolled, 123 (7.5%) developed spontaneous HT and 215 (13.1%) had reduced eGFR. Reduced eGFR was significantly associated with increased risk of spontaneous HT in all ischemic stroke patients (OR 1.821, 95% CI 1.081 to 3.06, P=0.024), and in the subgroup of large artery atherosclerosis, not in the cardio-embolism stroke group (OR 1.588, 95% CI 0.642 to 3.782, P=0.327). Reduced eGFR did not increase the risk of symptomatic hemorrhagic transformation (OR 0.937, 95%CI 0.247 to 3.577, P=0.924). In conclusion, reduced eGFR was significantly associated with increased risk of spontaneous HT in all ischemic stroke patients, and in large artery atherosclerosis, not in cardio-embolism stroke. Reduced eGFR did not increase the risk of

  3. Simple and direct determination of active ingredients in drugs by neutron activation analysis

    The increasing number of drugs in the market and the need for their control requires new, simple, fast and accurate analytical methods. Iodine, iron, manganese, silver and sodium were determined by INAA in various pharmaceutical formulations, representing capsules, injectables, powders for injection, solutions and tablets. From the results it appears that NAA could be used as an official method for the determination of iron, manganese and silver in pharmaceutical products, in which these elements are present as active ingredients, as well as for the control of the concentration limits for iodine and sodium. (author)

  4. Role of [{sup 18}F]FDG PET in prediction of KRAS and EGFR mutation status in patients with advanced non-small-cell lung cancer

    Caicedo, Carlos; Garcia-Velloso, Maria Jose; Vigil Diaz, Carmen; Richter Echevarria, Jose Angel [University of Navarra, Nuclear Medicine Department, University Clinic of Navarra, Pamplona (Spain); Lozano, Maria Dolores; Labiano, Tania [University of Navarra, Pathology Department, University Clinic of Navarra, Pamplona (Spain); Lopez-Picazo, Jose Maria; Gurpide, Alfonso; Perez Gracia, Jose Luis [University of Navarra, Oncology Department, University Clinic of Navarra, Pamplona (Spain); Zulueta, Javier [University of Navarra, Pulmonology Department, University Clinic of Navarra, Pamplona (Spain)

    2014-11-15

    The tumour molecular profile predicts the activity of epidermal growth factor receptor (EGFR) inhibitors in non-small-cell lung cancer (NSCLC). However, tissue availability and tumour heterogeneity limit its assessment. We evaluated whether [{sup 18}F]FDG PET might help predict KRAS and EFGR mutation status in NSCLC. Between January 2005 and October 2011, 340 NSCLC patients were tested for KRAS and EGFR mutation status. We identified patients with stage III and IV disease who had undergone [{sup 18}F]FDG PET/CT scanning for initial staging. SUVpeak, SUVmax and SUVmean of the single hottest tumour lesions were calculated, and their association with KRAS and EGFR mutation status was assessed. A receiver operator characteristic (ROC) curve analysis and a multivariate analysis (including SUVmean, gender, age and AJCC stage) were performed to identify the potential value of [{sup 18}F]FDG PET/CT for predicting KRAS mutation. From 102 patients staged using [{sup 18}F]FDG PET/CT, 28 (27 %) had KRAS mutation (KRAS+), 22 (22 %) had EGFR mutation (EGFR+) and 52 (51 %) had wild-type KRAS and EGFR profiles (WT). KRAS+ patients showed significantly higher [{sup 18}F]FDG uptake than EGFR+ and WT patients (SUVmean 9.5, 5.7 and 6.6, respectively; p < 0.001). No significant differences were observed in [{sup 18}F]FDG uptake between EGFR+ patients and WT patients. ROC curve analysis for KRAS mutation status discrimination yielded an area under the curve of 0.740 for SUVmean (p < 0.001). The multivariate analysis showed a sensitivity and specificity of 78.6 % and 62.2 %, respectively, and the AUC was 0.773. NSCLC patients with tumours harbouring KRAS mutations showed significantly higher [{sup 18}F]FDG uptake than WT patients, as assessed in terms of SUVpeak, SUVmax and SUVmean. A multivariate model based on age, gender, AJCC stage and SUVmean might be used as a predictive marker of KRAS mutation status in patients with stage III or IV NSCLC. (orig.)

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

    Chen H

    2013-10-01

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

  6. Genetic link between Cabeza, a Drosophila homologue of Fused in Sarcoma (FUS), and the EGFR signaling pathway

    Shimamura, Mai; Kyotani, Akane [Department of Applied Biology, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585 (Japan); Insect Biomedical Research Center, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585 (Japan); Azuma, Yumiko [Department of Neurology, Kyoto Prefectural University of Medicine, 465 Kajii-cho,Kamigyo-ku, Kyoto 602-8566 (Japan); Yoshida, Hideki; Binh Nguyen, Thanh [Department of Applied Biology, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585 (Japan); Insect Biomedical Research Center, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585 (Japan); Mizuta, Ikuko; Yoshida, Tomokatsu; Mizuno, Toshiki [Department of Neurology, Kyoto Prefectural University of Medicine, 465 Kajii-cho,Kamigyo-ku, Kyoto 602-8566 (Japan); Nakagawa, Masanori [North Medical Center, Kyoto Prefectural University of Medicine, 465 Kajii-cho, Kamigyo-ku, Kyoto 602-8566 (Japan); Tokuda, Takahiko, E-mail: ttokuda@koto.kpu-m.ac.jp [Department of Neurology, Kyoto Prefectural University of Medicine, 465 Kajii-cho,Kamigyo-ku, Kyoto 602-8566 (Japan); Department of Molecular Pathobiology of Brain Diseases, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, 465 Kajii-cho, Kamigyo-ku, Kyoto 602-8566 (Japan); Yamaguchi, Masamitsu, E-mail: myamaguc@kit.ac.jp [Department of Applied Biology, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585 (Japan); Insect Biomedical Research Center, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585 (Japan)

    2014-08-01

    Amyotrophic Lateral Sclerosis (ALS) is a fatal neurodegenerative disease that causes progressive muscular weakness. Fused in Sarcoma (FUS) that has been identified in familial ALS is an RNA binding protein that is normally localized in the nucleus. However, its function in vivo is not fully understood. Drosophila has Cabeza (Caz) as a FUS homologue and specific knockdown of Caz in the eye imaginal disc and pupal retina using a GMR-GAL4 driver was here found to induce an abnormal morphology of the adult compound eyes, a rough eye phenotype. This was partially suppressed by expression of the apoptosis inhibitor P35. Knockdown of Caz exerted no apparent effect on differentiation of photoreceptor cells. However, immunostaining with an antibody to Cut that marks cone cells revealed fusion of these and ommatidia of pupal retinae. These results indicate that Caz knockdown induces apoptosis and also inhibits differentiation of cone cells, resulting in abnormal eye morphology in adults. Mutation in EGFR pathway-related genes, such as rhomboid-1, rhomboid-3 and mirror suppressed the rough eye phenotype induced by Caz knockdown. Moreover, the rhomboid-1 mutation rescued the fusion of cone cells and ommatidia observed in Caz knockdown flies. The results suggest that Caz negatively regulates the EGFR signaling pathway required for determination of cone cell fate in Drosophila. - Highlights: • Knockdown of Cabeza induced rough eye phenotype. • Knockdown of Cabeza induced fusion of cone cells in pupal retinae. • Knockdown of Cabeza induced apoptosis in pupal retinae. • Mutation in EGFR pathway-related genes suppressed the rough eye phenotype. • Cabeza may negatively regulate the EGFR pathway.

  7. Implementation and Quality Control of Lung Cancer EGFR Genetic Testing by MALDI-TOF Mass Spectrometry in Taiwan Clinical Practice

    Su, Kang-Yi; Kao, Jau-Tsuen; Ho, Bing-Ching; Chen, Hsuan-Yu; Chang, Gee-Cheng; Ho, Chao-Chi; Yu, Sung-Liang

    2016-01-01

    Molecular diagnostics in cancer pharmacogenomics is indispensable for making targeted therapy decisions especially in lung cancer. For routine clinical practice, the flexible testing platform and implemented quality system are important for failure rate and turnaround time (TAT) reduction. We established and validated the multiplex EGFR testing by MALDI-TOF MS according to ISO15189 regulation and CLIA recommendation in Taiwan. Totally 8,147 cases from Aug-2011 to Jul-2015 were assayed and statistical characteristics were reported. The intra-run precision of EGFR mutation frequency was CV 2.15% (L858R) and 2.77% (T790M); the inter-run precision was CV 3.50% (L858R) and 2.84% (T790M). Accuracy tests by consensus reference biomaterials showed 100% consistence with datasheet (public database). Both analytical sensitivity and specificity were 100% while taking Sanger sequencing as the gold-standard method for comparison. EGFR mutation frequency of peripheral blood mononuclear cell for reference range determination was 0.002 ± 0.016% (95% CI: 0.000–0.036) (L858R) and 0.292 ± 0.289% (95% CI: 0.000–0.871) (T790M). The average TAT was 4.5 working days and the failure rate was less than 0.1%. In conclusion, this study provides a comprehensive report of lung cancer EGFR mutation detection from platform establishment, method validation to clinical routine practice. It may be a reference model for molecular diagnostics in cancer pharmacogenomics. PMID:27480787

  8. Genetic link between Cabeza, a Drosophila homologue of Fused in Sarcoma (FUS), and the EGFR signaling pathway

    Amyotrophic Lateral Sclerosis (ALS) is a fatal neurodegenerative disease that causes progressive muscular weakness. Fused in Sarcoma (FUS) that has been identified in familial ALS is an RNA binding protein that is normally localized in the nucleus. However, its function in vivo is not fully understood. Drosophila has Cabeza (Caz) as a FUS homologue and specific knockdown of Caz in the eye imaginal disc and pupal retina using a GMR-GAL4 driver was here found to induce an abnormal morphology of the adult compound eyes, a rough eye phenotype. This was partially suppressed by expression of the apoptosis inhibitor P35. Knockdown of Caz exerted no apparent effect on differentiation of photoreceptor cells. However, immunostaining with an antibody to Cut that marks cone cells revealed fusion of these and ommatidia of pupal retinae. These results indicate that Caz knockdown induces apoptosis and also inhibits differentiation of cone cells, resulting in abnormal eye morphology in adults. Mutation in EGFR pathway-related genes, such as rhomboid-1, rhomboid-3 and mirror suppressed the rough eye phenotype induced by Caz knockdown. Moreover, the rhomboid-1 mutation rescued the fusion of cone cells and ommatidia observed in Caz knockdown flies. The results suggest that Caz negatively regulates the EGFR signaling pathway required for determination of cone cell fate in Drosophila. - Highlights: • Knockdown of Cabeza induced rough eye phenotype. • Knockdown of Cabeza induced fusion of cone cells in pupal retinae. • Knockdown of Cabeza induced apoptosis in pupal retinae. • Mutation in EGFR pathway-related genes suppressed the rough eye phenotype. • Cabeza may negatively regulate the EGFR pathway

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

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

    2011-06-10

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

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

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

  11. Determination of the radioprotective activity of certain analogs of imipramine

    Investigation of some derivatives of azepine, structurally related to imipramine in view of their radioprotective activity towards γ-radiation. Among them, three compounds displayed significant activity

  12. Activity Assay of Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitors in Triple-Negative Breast Cancer Cells Using Peptide-Conjugated Magnetic Beads

    Ghosh, Gargi; Yan, Xiaoliang; Kron, Stephen J.; Palecek, Sean P.

    2013-01-01

    Triple-negative breast cancer (TNBC) is a highly aggressive subtype of breast cancer with limited treatment options. Epidermal growth factor receptor I (EGFR) has emerged as a promising target in TNBC. Limited success of the EGFR kinase inhibiting small molecules in clinical trials may be attributed in part to inaccuracy in identifying EGFR signatures in patient tumors. In light of the absence of a simple correlation between EGFR expression and its degree of activation, a simple and reliable ...

  13. Aminoflavone-loaded EGFR-targeted unimolecular micelle nanoparticles exhibit anti-cancer effects in triple negative breast cancer.

    Brinkman, Ashley M; Chen, Guojun; Wang, Yidan; Hedman, Curtis J; Sherer, Nathan M; Havighurst, Thomas C; Gong, Shaoqin; Xu, Wei

    2016-09-01

    Triple negative breast cancer (TNBC) is an aggressive subtype of breast cancer for which there is no available targeted therapy. TNBC cases contribute disproportionately to breast cancer-related mortality, thus the need for novel and effective therapeutic methods is urgent. We have previously shown that a National Cancer Institute (NCI) investigational drug aminoflavone (AF) exhibits strong growth inhibitory effects in TNBC cells. However, in vivo pulmonary toxicity resulted in withdrawal or termination of several human clinical trials for AF. Herein we report the in vivo efficacy of a nanoformulation of AF that enhances the therapeutic index of AF in TNBC. We engineered a unique unimolecular micelle nanoparticle (NP) loaded with AF and conjugated with GE11, a 12 amino acid peptide targeting epidermal growth factor receptor (EGFR), since EGFR amplification is frequently observed in TNBC tumors. These unimolecular micelles possessed excellent stability and preferentially released drug payload at endosomal pH levels rather than blood pH levels. Use of the GE11 targeting peptide resulted in enhanced cellular uptake and strong growth inhibitory effects in TNBC cells. Further, AF-loaded, GE11-conjugated (targeted) unimolecular micelle NPs significantly inhibit orthotopic TNBC tumor growth in a xenograft model, compared to treatment with AF-loaded, GE11-lacking (non-targeted) unimolecular micelle NPs or free AF. Interestingly, the animals treated with AF-loaded, targeted NPs had the highest plasma and tumor level of AF among different treatment groups yet exhibited no increase in plasma aspartate aminotransferase (AST) activity level or observable tissue damage at the time of sacrifice. Together, these results highlight AF-loaded, EGFR-targeted unimolecular micelle NPs as an effective therapeutic option for EGFR-overexpressing TNBC. PMID:27267625

  14. Thiolated chitosan nanoparticles as a delivery system for antisense therapy: evaluation against EGFR in T47D breast cancer cells

    Talaei F

    2011-09-01

    Full Text Available Fatemeh Talaei1, Ebrahim Azizi2, Rassoul Dinarvand3, Fatemeh Atyabi31Novel Drug Delivery Systems Lab, 2Molecular Research Lab, Department of Pharmacology and Toxicology, 3Nanotechnology Research Centre, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, IranAbstract: Thiolated chitosan has high transfection and mucoadhesive properties. We investigated the potential of two recently synthesized polymers: NAC-C (N-acetyl cysteine-chitosan and NAP-C (N-acetyl penicillamine-chitosan in anticancer drug delivery targeting epidermal growth factor receptor (EGFR. Doxorubicin (DOX and antisense oligonucleotide (ASOND-loaded polymer nanoparticles were prepared in water by a gelation process. Particle characterization, drug loading, and drug release were evaluated. To verify drug delivery efficiency in vitro experiments on a breast cancer cell line (T47D were performed. EGFR gene and protein expression was analyzed by real time quantitative polymerase chain reaction and Western blotting, respectively. A loading percentage of 63% ± 5% for ASOND and 70% ± 5% for DOX was achieved. Drug release data after 15 hours showed that ASOND and DOX were completely released from chitosan-based particles while a lower and more sustained release of only 22% ± 8% was measured for thiolated particles. In a cytosol simulated release medium/reducing environment, such as found intracellularly, polymer-based nanoparticles dissociated, liberating approximately 50% of both active substances within 7 hours. ASOND-loaded polymer nanoparticles had higher stability and high mucoadhesive properties. The ASOND-loaded thiolated particles significantly suppressed EGFR gene expression in T47D cells compared with ASOND-loaded chitosan particles and downregulated EGFR protein expression in cells. This study could facilitate future investigations into the functionality of NAP-C and NAC-C polymers as an efficient ASOND delivery system in vitro and in vivo

  15. Anti-EGFR-iRGD recombinant protein conjugated silk fibroin nanoparticles for enhanced tumor targeting and antitumor efficiency

    Bian, Xinyu; Wu, Puyuan; Sha, Huizi; Qian, Hanqing; Wang, Qing; Cheng, Lei; Yang, Yang; Yang, Mi; Liu, Baorui

    2016-01-01

    In this study, we report a novel kind of targeting with paclitaxel (PTX)-loaded silk fibroin nanoparticles conjugated with iRGD–EGFR nanobody recombinant protein (anti-EGFR-iRGD). The new nanoparticles (called A-PTX-SF-NPs) were prepared using the carbodiimide-mediated coupling procedure and their characteristics were evaluated. The cellular cytotoxicity and cellular uptake of A-PTX-SF-NPs were also investigated. The results in vivo suggested that NPs conjugated with the recombinant protein exhibited more targeting and anti-neoplastic property in cells with high EGFR expression. In the in vivo antitumor efficacy assay, the A-PTX-SF-NPs group showed slower tumor growth and smaller tumor volumes than PTX-SF-NPs in a HeLa xenograft mouse model. A real-time near-infrared fluorescence imaging study showed that A-PTX-SF-NPs could target the tumor more effectively. These results suggest that the anticancer activity and tumor targeting of A-PTX-SF-NPs were superior to those of PTX-SF-NPs and may have the potential to be used for targeted delivery for tumor therapies.

  16. EGFR-Targeting as a Biological Therapy: Understanding Nimotuzumab's Clinical Effects

    Perez, Rolando, E-mail: rolando@cim.sld.cu; Moreno, Ernesto; Garrido, Greta; Crombet, Tania [Center of Molecular Immunology, P.O. Box 16040, Havana 11600 (Cuba)

    2011-04-18

    Current clinical trials of epidermal growth factor receptor (EGFR)-targeted therapies are mostly guided by a classical approach coming from the cytotoxic paradigm. The predominant view is that the efficacy of EGFR antagonists correlates with skin rash toxicity and induction of objective clinical response. Clinical benefit from EGFR-targeted therapies is well documented; however, chronic use in advanced cancer patients has been limited due to cumulative and chemotherapy-enhanced toxicity. Here we analyze different pieces of data from mechanistic and clinical studies with the anti-EGFR monoclonal antibody Nimotuzumab, which provides several clues to understand how this antibody may induce a biological control of tumor growth while keeping a low toxicity profile. Based on these results and the current state of the art on EGFR-targeted therapies, we discuss the need to evaluate new therapeutic approaches using anti-EGFR agents, which would have the potential of transforming advanced cancer into a long-term controlled chronic disease.

  17. Role of LPAR3, PKC and EGFR in LPA-induced cell migration in oral squamous carcinoma cells

    Oral squamous cell carcinoma is an aggressive neoplasm with serious morbidity and mortality, which typically spreads through local invasive growth. Lysophosphatidic acid (LPA) is involved in a number of biological processes, and may have a role in cancer cell migration and invasiveness. LPA is present in most tissues and can activate cells through six different LPA receptors (LPAR1-6). Although LPA is predominantly promigratory, some of the receptors may have antimigratory effects in certain cells. The signalling mechanisms of LPA are not fully understood, and in oral carcinoma cells the specific receptors and pathways involved in LPA-stimulated migration are unknown. The oral carcinoma cell lines E10, SCC-9, and D2 were investigated. Cell migration was studied in a scratch wound assay, and invasion was demonstrated in organotypic three dimensional co-cultures. Protein and mRNA expression of LPA receptors was studied with Western blotting and qRT-PCR. Activation of signalling proteins was examined with Western blotting and isoelectric focusing, and signalling mechanisms were further explored using pharmacological agents and siRNA directed at specific receptors and pathways. LPA stimulated cell migration in the two oral carcinoma cell lines E10 and SCC-9, but was slightly inhibitory in D2. The receptor expression profile and the effects of specific pharmacological antagonist and agonists indicated that LPA-stimulated cell migration was mediated through LPAR3 in E10 and SCC-9. Furthermore, in both these cell lines, the stimulation by LPA was dependent on PKC activity. However, while LPA induced transactivation of EGFR and the stimulated migration was blocked by EGFR inhibitors in E10 cells, LPA did not induce EGFR transactivation in SCC-9 cells. In D2 cells, LPA induced EGFR transactivation, but this was associated with slowing of a very high inherent migration rate in these cells. The results demonstrate LPA-stimulated migration in oral carcinoma cells through LPAR3

  18. A Rapid, Sensitive Assay to Detect EGFR Mutation in Small Biopsy Specimens from Lung Cancer

    Yatabe, Yasushi; Hida, Toyoaki; Horio, Yoshitsugu; Kosaka, Takayuki; Takahashi, Takashi; Mitsudomi, Tetsuya

    2006-01-01

    It has been demonstrated that lung cancers, specifically a subset of pulmonary adenocarcinomas, with epidermal growth factor receptor (EGFR) mutation are highly sensitive to EGFR-targeted drugs. Therefore, a rapid, sensitive assay for mutation detection using routine pathological specimens is demanded in clinical practice to predict the response. We therefore developed a new assay for detecting EGFR mutation using only a paraffin section of a small biopsy specimen. The method was very sensiti...

  19. Erlotinib-mediated Inhibition of EGFR Signaling Induces Metabolic Oxidative Stress through NOX4

    Orcutt, Kevin P.; Parsons, Arlene D.; Sibenaller, Zita A.; Scarbrough, Peter M.; Zhu, Yueming; Sobhakumari, Arya; Wilke, Werner W.; Kalen, Amanda L.; Goswami, Prabhat; Miller, Francis J.; Spitz, Douglas R.; Simons, Andrean L.

    2011-01-01

    Redox regulation of EGFR signaling helps protect cells against oxidative stress. In this study, we investigated whether the cytotoxicity of an EGFR tyrosine kinase inhibitor, erlotinib (ERL), was mediated by induction of oxidative stress in human head and neck cancer (HNSCC) cells. ERL elicited cytotoxicity in vitro and in vivo while increasing a panel of oxidative stress parameters which were all reversible by the antioxidant N-acetyl cysteine. Knockdown of EGFR using siRNA similarly increas...

  20. Selected Reaction Monitoring (SRM) Analysis of Epidermal Growth Factor Receptor (EGFR) in Formalin Fixed Tumor Tissue

    Hembrough Todd; Thyparambil Sheeno; Liao Wei-Li; Darfler Marlene M; Abdo Joseph; Bengali Kathleen M; Taylor Paul; Tong Jiefei; Lara-Guerra Humberto; Waddell Thomas K; Moran Michael F; Tsao Ming-Sound; Krizman David B; Burrows Jon

    2012-01-01

    Abstract Background Analysis of key therapeutic targets such as epidermal growth factor receptor (EGFR) in clinical tissue samples is typically done by immunohistochemistry (IHC) and is only subjectively quantitative through a narrow dynamic range. The development of a standardized, highly-sensitive, linear, and quantitative assay for EGFR for use in patient tumor tissue carries high potential for identifying those patients most likely to benefit from EGFR-targeted therapies. Methods A mass s...

  1. Rhbdf2 mutations increase its protein stability and drive EGFR hyperactivation through enhanced secretion of amphiregulin

    Hosur, Vishnu; Johnson, Kenneth R.; Burzenski, Lisa M.; Stearns, Timothy M; Maser, Richard S.; Shultz, Leonard D.

    2014-01-01

    Epidermal growth factor receptor (EGFR) signal transduction plays a major role in growth, proliferation, and differentiation of mammalian cells. Although inactive rhomboids (iRhoms) are cardinal regulators of EGFR signaling in Drosophila melanogaster, their physiological role in regulating EGFR signaling and their substrates in mammals remain unclear. Here, we show that iRhoms are short-lived proteins, but dominant mutations increase their protein stability and stimulate secretion of specific...

  2. An intracellular targeted antibody detects EGFR as an independent prognostic factor in ovarian carcinomas

    In ovarian cancer, the reported rate of EGFR expression varies between 4-70% depending on assessment method and data on patient outcome are conflicting. Methods: In this study we investigated EGFR expression and its prognostic value in a cohort of 121 invasive ovarian carcinomas, using a novel antibody against the intracellular domain of the receptor. We further evaluated an association between EGFR, the nuclear transporter CRM1 as well as COX-2. Furthermore, we evaluated EGFR expression in ten ovarian cancer cell lines and incubated cancer cells with Leptomycin B, a CRM1 specific inhibitor. We observed a membranous and cytoplasmic EGFR expression in 36.4% and 64% of ovarian carcinomas, respectively. Membranous EGFR was an independent prognostic factor for poor overall survival in ovarian cancer patients (HR 2.7, CI 1.1-6.4, p = 0.02) which was also found in the serous subtype (HR 4.6, CI 1.6-13.4, p = 0.004). We further observed a significant association of EGFR with COX-2 and nuclear CRM1 expression (chi-square test for trends, p = 0.006 and p = 0.013, respectively). In addition, combined membranous EGFR/COX-2 expression was significantly related to unfavorable overall survival (HR 7.2, CI 2.3-22.1, p = 0.001). In cell culture, we observed a suppression of EGFR protein levels after exposure to Leptomycin B in OVCAR-3 and SKOV-3 cells. Our results suggest that the EGFR/COX-2/CRM1 interaction might be involved in progression of ovarian cancer and patient prognosis. Hence, it is an interesting anti-cancer target for a combination therapy. Further studies will also be needed to investigate whether EGFR is also predictive for benefit from EGFR targeted therapies

  3. Frequency of EGFR Mutations in 907 Lung Adenocarcioma Patients of Indian Ethnicity

    Anuradha Chougule; Kumar Prabhash; Vanita Noronha; Amit Joshi; Abhishek Thavamani; Pratik Chandrani; Pawan Upadhyay; Sagarika Utture; Saral Desai; Nirmala Jambhekar; Amit Dutt

    2013-01-01

    BACKGROUND: During the past decade, the incidence of EGFR mutation has been shown to vary across different ethnicities. It occurs at the rate of 10-15% in North Americans and Europeans, 19% in African-Americans, 20-30% in various East Asian series including Chinese, Koreans, and Japanese. Frequency of EGFR mutations in India however remains sparsely explored. METHODOLOGY/PRINCIPAL FINDINGS: We report 23% incidence of Epidermal growth factor receptor (EGFR) mutations in 907 Non small cell lung...

  4. EGFR gene-mutation status correlated with therapeutic decision making in lung adenocarcinoma

    Ren YY; Yao YB; Ma Q; Zhong DS

    2015-01-01

    Yaoyao Ren, Yibing Yao, Qing Ma, Diansheng Zhong Oncology Department, Tianjin Medical University General Hospital, Tianjin, People’s Republic of China Abstract: The purpose of this study was to investigate the correlation between EGFR-mutation status and treatment efficacy for advanced lung adenocarcinoma patients. A total of 47 patients receiving erlotinib as first-line therapy were divided into two groups: the EGFR gene mutation group included 19 patients with known EGFR-sensiti...

  5. New Strategies in Overcoming Acquired Resistance to EGFR Tyrosine Kinase Inhibitors in Lung Cancer

    Oxnard, Geoffrey R.; Arcila, Maria E.; Chmielecki, Juliann; Ladanyi, Marc; Miller, Vincent A.; Pao, William

    2011-01-01

    The management of non-small cell lung cancer (NSCLC) has been transformed by the observation that lung adenocarcinomas harboring mutations in EGFR are uniquely sensitive to EGFR tyrosine kinase inhibitors (TKIs). In these patients, acquired resistance to EGFR-TKI develops after a median of 10-14 months, at which time the current standard practice is to switch to conventional cytotoxic chemotherapy. Several possible mechanisms for acquired resistance have been identified, the most common being...

  6. An intracellular targeted antibody detects EGFR as an independent prognostic factor in ovarian carcinomas

    Braicu Elena I; Sehouli Jalid; Buckendahl Ann-Christin; Darb-Esfahani Silvia; Weichert Wilko; Schwabe Michael; Noske Aurelia; Budczies Jan; Dietel Manfred; Denkert Carsten

    2011-01-01

    Abstract Background In ovarian cancer, the reported rate of EGFR expression varies between 4-70% depending on assessment method and data on patient outcome are conflicting. Methods: In this study we investigated EGFR expression and its prognostic value in a cohort of 121 invasive ovarian carcinomas, using a novel antibody against the intracellular domain of the receptor. We further evaluated an association between EGFR, the nuclear transporter CRM1 as well as COX-2. Furthermore, we evaluated ...

  7. Acquired MET expression confers resistance to EGFR inhibition in a mouse model of glioblastoma multiforme

    Jun, Hyun Jung; Acquaviva, Jaime; Chi, Dorcas; Lessard, Julie; Zhu, Haihao; Woolfenden, Steve; Bronson, Roderick T.; Pfannl, Rolf; White, Forest; Housman, David E.; Iyer, Lakshmanan; Whittaker, Charles A; Boskovitz, Abraham; Raval, Ami; Charest, Alain

    2011-01-01

    Glioblastoma multiforme (GBM) is an aggressive brain tumor for which there is no cure. Overexpression of wild-type epidermal growth factor receptor (EGFR) and loss of the tumor suppressor genes Ink4a/Arf and PTEN are salient features of this deadly cancer. Surprisingly, targeted inhibition of EGFR has been clinically disappointing, demonstrating an innate ability for GBM to develop resistance. Efforts at modeling GBM in mice using wild-type EGFR have proven unsuccessful to date, hampering end...

  8. Acquired MET Expression Confers Resistance to EGFR Inhibition In a Mouse Model of Glioblastoma Multiforme

    Jun, Hyun Jung; Acquaviva, Jaime; Chi, Dorcas; Lessard, Julie; Zhu, Haihao; Woolfenden, Steve; Bronson, Roderick T.; Pfannl, Rolf; White, Forest; Housman, David E.; Iyer, Lakshmanan; Whittaker, Charles A; Boskovitz, Abraham; Raval, Ami; Charest, Alain

    2013-01-01

    Glioblastoma Multiforme (GBM) is an aggressive brain tumor for which there is no cure. Overexpression of wild-type EGFR and loss of the tumor suppressor genes Ink4a/Arf and PTEN are salient features of this deadly cancer. Surprisingly, targeted inhibition of EGFR has been clinically disappointing, demonstrating an innate ability for GBM to develop resistance. Efforts at modeling GBM in mice using wild-type EGFR have proven unsuccessful to date, hampering endeavors at understanding molecular m...

  9. Pyrosequencing, a method approved to detect the two major EGFR mutations for anti EGFR therapy in NSCLC

    Richard Marie-Jeanne

    2011-05-01

    Full Text Available Abstract Background Epidermal Growth Factor Receptor (EGFR mutations, especially in-frame deletions in exon 19 (ΔLRE and a point mutation in exon 21 (L858R predict gefitinib sensitivity in patients with non-small cell lung cancer. Several methods are currently described for their detection but the gold standard for tissue samples remains direct DNA sequencing, which requires samples containing at least 50% of tumor cells. Methods We designed a pyrosequencing assay based on nested PCR for the characterization of theses mutations on formalin-fixed and paraffin-embedded tumor tissue. Results This method is highly specific and permits precise characterization of all the exon 19 deletions. Its sensitivity is higher than that of "BigDye terminator" sequencing and enabled detection of 3 additional mutations in the 58 NSCLC tested. The concordance between the two methods was very good (97.4%. In the prospective analysis of 213 samples, 7 (3.3% samples were not analyzed and EGFR mutations were detected in 18 (8.7% patients. However, we observed a deficit of mutation detection when the samples were very poor in tumor cells. Conclusions pyrosequencing is then a highly accurate method for detecting ΔLRE and L858R EGFR mutations in patients with NSCLC when the samples contain at least 20% of tumor cells.

  10. Evolution of the EGFR pathway in Metazoa and its diversification in the planarian Schmidtea mediterranea.

    Barberán, Sara; Martín-Durán, José M; Cebrià, Francesc

    2016-01-01

    The EGFR pathway is an essential signaling system in animals, whose core components are the epidermal growth factors (EGF ligands) and their trans-membrane tyrosine kinase receptors (EGFRs). Despite extensive knowledge in classical model organisms, little is known of the composition and function of the EGFR pathway in most animal lineages. Here, we have performed an extensive search for the presence of EGFRs and EGF ligands in representative species of most major animal clades, with special focus on the planarian Schmidtea mediterranea. With the exception of placozoans and cnidarians, we found that the EGFR pathway is potentially present in all other analyzed animal groups, and has experienced frequent independent expansions. We further characterized the expression domains of the EGFR/EGF identified in S. mediterranea, revealing a wide variety of patterns and localization in almost all planarian tissues. Finally, functional experiments suggest an interaction between one of the previously described receptors, Smed-egfr-5, and the newly found ligand Smed-egf-6. Our findings provide the most comprehensive overview to date of the EGFR pathway, and indicate that the last common metazoan ancestor had an initial complement of one EGFR and one putative EGF ligand, which was often expanded or lost during animal evolution. PMID:27325311

  11. Differential effects of EGFR ligands on endocytic sorting of the receptor

    Roepstorff, Kirstine; Grandal, Michael Vibo; Henriksen, Lasse;

    2009-01-01

    signalling and is a more potent mitogen than EGF. In addition to EGF and TGF-alpha, five EGFR ligands have been identified. Although many of these ligands are upregulated in cancers, very little is known about their effect on EGFR trafficking. We have compared the effect of six different ligands on endocytic...... trafficking of EGFR. We find that, whereas they all stimulate receptor internalization, they have very diverse effects on endocytic sorting. Heparin-binding EGF-like growth factor and Betacellulin target all EGFRs for lysosomal degradation. In contrast, TGF-alpha and epiregulin lead to complete receptor...

  12. Determination of Teloschistes flavicans (sw norm anti-inflammatory activity

    Eugênia C Pereira

    2010-01-01

    Full Text Available Background: Lichens produce a variety of substances that possesses pharmacological actions. However, rare products are submitted to rigorous scientific tests or have the risk potential or side effects evaluated. The lack of medical and sanitary control, absence of accurate botanical identification or purity certification, founded in diverse natural products, may represent great danger to population health. This work aimed to evaluate toxic effects and anti-inflammatory action in vivo of Teloschistes flavicans (Sw. Norm. (TFN unrefined extracts, as well as determinate its main constituents. Methods: The carrageenan induced paw edema and cotton pellet implant induced granuloma methods were utilized, besides a classic acute toxicity test. TFN acetone extract inhibited carrageenan paw edema on 60, 120, and 180 min (inhibition percentiles of 45.03%, 60.59% and 41.72%. Results: TFN ethereal (inhibition percentiles of 23.95% and 29.01% and chloroform (inhibition percentiles of 28.8% and 22.04% extracts inhibited edema on 120 and 180 min. None of the extract inhibited the granuloma development. None of the extract caused death or other acute toxicity signs. Vicanicine (60.26% in ethereal extract and 51.17% in acetone extract, parietine (9.60% in ethereal extract and 15.38% on second, falacinol (0.78% in ether and 14.95% in acetone and very low concentration of falacinal (0.15% in ethereal extract and 3.32% in acetone extract were detected in the medicine. Conclusions: The tested extracts have antiedematogenic activity, but are not effective on subchronic inflammation. The extracts do not present toxic effects in administered doses.

  13. Lysosomally cleavable peptide-containing polymersomes modified with anti-EGFR antibody for systemic cancer chemotherapy.

    Lee, Jung S; Groothuis, Tom; Cusan, Claudia; Mink, Daniel; Feijen, Jan

    2011-12-01

    Polymersomes (Ps) based on a biodegradable and biocompatible block copolymer of methoxy poly(ethylene glycol) (mPEG) and poly(D,L-lactide) (PDLLA) in which apeptide sequence, Gly-Phe-Leu-Gly-Phe (GFLGF), was introduced in between the two blocks(mPEG-pep-PDLLA) were developed. The peptide linker is cleavable by the lysosomal enzymecathepsin B (Cath B). Ps containing the peptide linker (Ps(pep)) with an average diameter of about 124 nm were prepared by injecting a THF solution of the block copolymer into DI water. The Ps had a membrane thickness of about 15 nm as determined by transmission electron microscopy (TEM). In order to investigate the enzymatic degradation of the Ps (pep), dynamic light scattering (DLS) measurements of Ps(pep) dispersions with different concentrations of Cath B at pH 5.5 and 7.4 were performed as a function of time. A gradual decrease in kilo counts per second (Kcps) of the Ps (pep) over 7 d was observed after incubation of the Ps (pep) dispersions with 5 units/ml of Cath B at pH 5.5 at 37 °C. The size distribution became also bimodal, indicating that aggregation and precipitation of Ps (pep) occurred by disintegration of the Ps (pep) as a result of cleavage of the peptide. The rate of disintegration of the Ps (pep) was depending on the concentration of Cath Band the pH. No changes by DLS were seen when the dispersions were incubated with the enzyme at pH 7.4. Acridine orange (AO) was encapsulated in Ps (pep)as a model drug and rapid release of AO triggered by Cath B degradation of Ps (pep) was observed at pH 5.5. Anti-epidermal growth factor receptor (anti-EGFR) antibody (abEGFR) was immobilized on the surface of Ps(pep)in order to enhance the cellular uptake of Ps (pep). Fluorescein isothiocyanate labeled dextran (40,000 g/mol) (FD40) was incorporated in the Ps (pep) for the cell study and Ps either without peptide or antibody or without both peptide and antibody were used as negative controls. After 3 d exposure to SKBR3 cells, abEGFR

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

    Praveenkumar K Shetty

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

  15. Combined therapy with mutant-selective EGFR inhibitor and Met kinase inhibitor for overcoming erlotinib resistance in EGFR-mutant lung cancer.

    Nakagawa, Takayuki; Takeuchi, Shinji; Yamada, Tadaaki; Nanjo, Shigeki; Ishikawa, Daisuke; Sano, Takako; Kita, Kenji; Nakamura, Takahiro; Matsumoto, Kunio; Suda, Kenichi; Mitsudomi, Tetsuya; Sekido, Yoshitaka; Uenaka, Toshimitsu; Yano, Seiji

    2012-10-01

    Although the EGF receptor tyrosine kinase inhibitors (EGFR-TKI) erlotinib and gefitinib have shown dramatic effects against EGFR mutant lung cancer, patients become resistant by various mechanisms, including gatekeeper EGFR-T790M mutation, Met amplification, and HGF overexpression, thereafter relapsing. Thus, it is urgent to develop novel agents to overcome EGFR-TKI resistance. We have tested the effects of the mutant-selective EGFR-TKI WZ4002 and the mutant-selective Met-TKI E7050 on 3 EGFR mutant lung cancer cell lines resistant to erlotinib by different mechanisms: PC-9/HGF cells with an exon 19 deletion, H1975 with an L858R mutation, and HCC827ER with an exon 19 deletion, with acquired resistance to erlotinib because of HGF gene transfection, gatekeeper T790M mutation, and Met amplification, respectively. WZ4002 inhibited the growth of H1975 cells with a gatekeeper T790M mutation, but did not inhibit the growth of HCC827ER and PC-9/HGF cells. HGF triggered the resistance of H1975 cells to WZ4002, whereas E7050 sensitized HCC827ER, PC-9/HGF, and HGF-treated H1975 cells to WZ4002, inhibiting EGFR and Met phosphorylation and their downstream molecules. Combined treatment potently inhibited the growth of tumors induced in severe-combined immunodeficient mice by H1975, HCC827ER, and PC-9/HGF cells, without any marked adverse events. These therapeutic effects were associated with the inhibition of EGFR and Met phosphorylation in vivo. The combination of a mutant-selective EGFR-TKI and a Met-TKI was effective in suppressing the growth of erlotinib-resistant tumors caused by gatekeeper T790M mutation, Met amplification, and HGF overexpression. Further evaluations in clinical trials are warranted. PMID:22844075

  16. Molecular mechanisms of the enhanced anti-tumor effect of ionizing radiation by epidermal growth factor receptor (EGFR) blockade: the role of vascular endothelial growth factor (VEGF)

    Recent studies demonstrating that inhibition of the EGFR enhances the anti-tumor effect of radiation have prompted the commencement of clinical trials of this therapeutic strategy. The mechanisms involved in this interaction remain to be fully established and are potentially important for patient selection, as well as understanding the basis of resistance to this approach. Initial studies with the EGFR tyrosine kinase inhibitor gefitinib (ZD1839, Iressa) used in combination with radiation in A431 xenografts in nude mice demonstrated greater in vivo than in vitro effects. An effect on angiogenesis was suggested by reductions in microvessel staining and VEGF expression in tumors treated with ZD1839. Measurement of VEGF production of cell culture supernatant demonstrated that gefitinib is able to inhibit EGF-stimulated as well as basal VEGF production in A431 cells as well as in other cell lines including head and neck squamous cell carcinoma (SCC-25) and androgen-insensitive prostate cancer (DU145). Signal transduction pathways downstream of the EGF leading to VEGF production were dissected using specific inhibitors of PI3K (LY294002), MAPK (U0126), and p38 Kinase (SB203580) in A431 cells. Inhibition of PI3K reduced EGF stimulated VEGF production. Similarly EGF stimulated HIF-1alpha protein expression was reduced by EGFR inhibition with gefitinib as well as by downstream inhibition of PI3K. Cell lines producingVEGF in a doxycycline-inducible manner (pBIEGFPVEGF165) have been generated to determine the effects of maintaining VEGF expression despite EGFR inhibition. Experiments performed in vivo with these lines to determine if inducible-VEGF expression rescues tumors from the enhanced effects of radiation in combination with EGFR inhibition will be presented

  17. Inhibition of EGFR or IGF-1R signaling enhances radiation response in head and neck cancer models but concurrent inhibition has no added benefit

    Interaction between the epidermal growth factor receptor (EGFR) and the insulin-like growth factor receptor (IGF-1R) has been well established in many cancer types. We investigated the effects of cetuximab (EGFR antibody) and IMC-A12 (IGF-1R antibody) on the response of head and neck squamous cell carcinoma (HNSCC) to radiation therapy (RT). The effects of cetuximab and IMC-A12 on cell viability and radiosensitivity were determined by clonogenic cell survival assay. Formation of nuclear γ-H2AX and 53BP1 foci was monitored by immunofluorescence. Alterations in target signaling were analyzed by Western blots. In vivo tumor growth delay assay was performed to determine the efficacy of triple therapy with IMC-A12, cetuximab, and RT. In vitro data showed that cetuximab differentially affected the survival and the radiosensitivity of HNSCC cells. Cetuximab suppressed DNA repair that was evident by the prolonged presence of nuclear γ-H2AX and 53BP1 foci. IMC-A12 did not have any effect on the cell survival. However, it increased the radiosensitivity of one of the cell lines. EGFR inhibition increased IGF-1R expression levels and also the association between EGFR and IGF-1R. Addition of IMC-A12 to cetuximab did not increase the radiosensitivity of these cells. Tumor xenografts exhibited enhanced response to RT in the presence of either cetuximab or IMC-A12. Concurrent treatment regimen failed to further enhance the tumor response to cetuximab and/or RT. Taken together our data suggest that concomitant inhibition of both EGFR and IGF-1R pathways did not yield additional therapeutic benefit in overcoming resistance to RT

  18. Acquired EGFR C797S mediates resistance to AZD9291 in advanced non-small cell lung cancer harboring EGFR T790M

    Thress, Kenneth S.; Paweletz, Cloud P.; Felip, Enriqueta; Cho, Byoung Chul; Stetson, Daniel; Dougherty, Brian; Lai, Zhongwu; Markovets, Aleksandra; Vivancos, Ana; Kuang, Yanan; Ercan, Dalia; Matthews, Sarah; Cantarini, Mireille; Barrett, J. Carl; Jänne, Pasi A.

    2015-01-01

    Here we studied cell-free p