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Sample records for factor receptor proto-oncogene

  1. Expression of hepatocyte growth factor and the proto-oncogenic receptor c-Met in canine osteosarcoma

    NARCIS (Netherlands)

    Fieten, H; Spee, B; Ijzer, J; Kik, M J; Penning, L C; Kirpensteijn, J

    Hepatocyte growth factor (HGF) and the proto-oncogenic receptor c-Met are implicated in growth, invasion, and metastasis in human cancer. Little information is available on the expression and role of both gene products in canine osteosarcoma. We hypothesized that the expression of c-Met is

  2. Macrophage colony-stimulating factor, CSF-1, and its proto-oncogene-encoded receptor

    International Nuclear Information System (INIS)

    Sherr, C.J.; Rettenmier, C.W.; Roussel, M.F.

    1988-01-01

    The macrophage colony-stimulating factor, CSF-1, or M-CSF, is one of a family of hematopoietic growth factors that stimulates the proliferation of monocytes, macrophages, and their committed bone marrow progenitors. Unlike pluripotent hemopoietins such as granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin-3 (IL-3 or multi-CSF), which affect the growth of myeloid cells of several different hematopoietic lineages, CSF-1 acts only on cells of the mononuclear phagocyte series to stimulate their growth and enhance their survival. Retroviral transduction of the feline c-fms gene in the Susan McDonough and Hardy Zuckerman-5 (HZ-5) strains of feline sarcoma virus (FeSV) led to genetic alterations that endowed the recombined viral oncogene (v-fms) with the ability to transform cells in culture morphologically and to induce firbrosarcomas and hematopoietic neoplasms in susceptible animals. The v-fms oncogene product differs from the normal CSF-1 receptor in certain of its cardinal biochemical properties, most notably in exhibiting constitutively high basal levels of tyrosine kinase activity in the absence of its ligand. Comparative studies of the c-fms and v-fms genes coupled with analyses of engineered mutants and receptor chimeras have begun to pinpoint pertinent genetic alterations in the normal receptor gene that unmask its latent oncogenic potential. In addition, the availability of biologically active c-fms, v-fms, and CSF-1 cDNAs has allowed these genes to be mobilized and expressed in naive cells, thereby facilitating assays for receptor coupling with downstream components of the mitogenic pathway in diverse cell types

  3. The proto-oncogene product c-Crk associates with insulin receptor substrate-1 and 4PS. Modulation by insulin growth factor-I (IGF) and enhanced IGF-I signaling.

    Science.gov (United States)

    Beitner-Johnson, D; Blakesley, V A; Shen-Orr, Z; Jimenez, M; Stannard, B; Wang, L M; Pierce, J; LeRoith, D

    1996-04-19

    The Crk proto-oncogene product is an SH2 and SH3 domain-containing adaptor protein which we have previously shown to become rapidly tyrosine phosphorylated in response to stimulation with insulin-like growth factor I (IGF-I) in NIH-3T3 cells. In order to further characterize the role of Crk in the IGF-I signaling pathway, NIH-3T3 and 293 cells were stably transfected with an expression vector containing the Crk cDNA. The various resultant 3T3-Crk clones expressed Crk at approximately 2-15-fold higher levels than parental 3T3 cells. In 3T3-Crk cells, Crk immunoreactivity was detected in insulin receptor substrate-1 (IRS-1) immunoprecipitates. Stimulation with IGF-I resulted in a dissociation of Crk protein from IRS-1. In contrast, the association of the related adaptor protein Grb2 with IRS-1 was enhanced by IGF-I stimulation. Similar results were obtained in stably transfected 293-Crk cells, which express both IRS-1 and the IRS-1-related signaling protein 4PS. In these cells, IRS-1 and 4PS both associated with Crk, and this association was also decreased by IGF-I treatment, whereas the association of Grb2 with IRS-1 and 4PS was enhanced by IGF-I. Overexpression of Crk also enhanced IGF-I-induced mitogenesis of NIH-3T3 cells, as measured by [3H]thymidine incorporation. The levels of IGF-I-induced mitogenesis were proportional to the level of Crk expression. These results suggest that Crk is a positive effector of IGF-I signaling, and may mediate its effects via interaction with IRS-1 and/or 4PS.

  4. Activation of phosphatidylinositol-3 kinase by nerve growth factor involves indirect coupling of the trk proto-oncogene with src homology 2 domains.

    Science.gov (United States)

    Ohmichi, M; Decker, S J; Saltiel, A R

    1992-10-01

    Growth factor receptor tyrosine kinases can form stable associations with intracellular proteins that contain src homology (SH) 2 domains, including the p85 regulatory subunit of phosphatidylinositol (PI)-3 kinase. The activation of this enzyme by growth factors is evaluated in PC12 pheochromocytoma cells and NIH 3T3 fibroblasts expressing the pp140c-trk nerve growth factor (NGF) receptor (3T3-c-trk). NGF causes the rapid stimulation of PI-3 kinase activity detected in anti-phosphotyrosine, but not in anti-trk, immunoprecipitates. This effect coincides with the tyrosine phosphorylation of two proteins, with molecular masses of of 100 kd and 110 kd, that coimmunoprecipitate with p85. Similar phosphorylation patterns are induced when an immobilized fusion protein containing the amino-terminal SH2 domain of p85 is used to precipitate tyrosine-phosphorylated proteins. Thus, although NGF produces the rapid activation of PI-3 kinase through a mechanism that involves tyrosine phosphorylation, there is no evidence for tyrosine phosphorylation of p85, or for its ligand-dependent association with the NGF receptor. Perhaps another phosphoprotein may link the NGF receptor to this enzyme.

  5. Bioinformatics of non small cell lung cancer and the ras proto-oncogene

    CERN Document Server

    Kashyap, Amita; Babu M, Naresh

    2015-01-01

    Cancer is initiated by activation of oncogenes or inactivation of tumor suppressor genes. Mutations in the K-ras proto-oncogene are responsible for 10–30% of adenocarcinomas. Clinical Findings point to a wide variety of other cancers contributing to lung cancer incidence. Such a scenario makes identification of lung cancer difficult and thus identifying its mechanisms can contribute to the society. Identifying unique conserved patterns common to contributing proto-oncogenes may further be a boon to Pharmacogenomics and pharmacoinformatics. This calls for ab initio/de novo drug discovery that in turn will require a comprehensive in silico approach of Sequence, Domain, Phylogenetic and Structural analysis of the receptors, ligand screening and optimization and detailed Docking studies. This brief involves extensive role of the RAS subfamily that includes a set of proteins, which cause an over expression of cancer-causing genes like M-ras and initiate tumour formation in lungs. SNP Studies and Structure based ...

  6. Expression of proto-oncogenes in non-Hodgkin's lymphomas by in situ hybridization with biotinylated DNA probes

    International Nuclear Information System (INIS)

    Hamatani, Kiyohiro; Yoshida, Kuniko; Abe, Masumi; Shimaoka, Katsutaro; Shiku, Hiroshi; Akiyama, Mitoshi; Kondo, Hisayoshi.

    1989-11-01

    Expression of six proto-oncogenes (fos, myc, myb, Ki-ras, Ha-ras, and N-ras) in 43 cases of non-Hodgkin's lymphoma was analyzed by means of in situ hybridization. Biotinylated DNA probes of the six oncogenes and those of the immunoglobulin H-chain (IgH) gene and the T cell receptor β-chain (TCRβ) gene were used. The results of in situ hybridization performed under blind conditions by IgH and TCRβ gene probes were compatible with those of typing by cell surface markers. The nuclear protein-related proto-oncogenes, fos myc, and myb, were expressed in about 70 % - 80 % of all cases regardless of phenotypes, histology or histologic grade. On the contrary, genes of the ras family were expressed in fewer cases except for the Ki-ras gene which was more frequently expressed by cases of the T cell immunophenotype with a high malignancy grade. The results of dot hybridization with RNA extracted from some cases were compatible with those of in situ hybridization, further demonstrating the specificity of in situ hybridization. (author)

  7. Identification of a Novel Proto-oncogenic Network in Head and Neck Squamous Cell Carcinoma.

    Science.gov (United States)

    Georgy, Smitha R; Cangkrama, Michael; Srivastava, Seema; Partridge, Darren; Auden, Alana; Dworkin, Sebastian; McLean, Catriona A; Jane, Stephen M; Darido, Charbel

    2015-09-01

    The developmental transcription factor Grainyhead-like 3 (GRHL3) plays a critical tumor suppressor role in the mammalian epidermis through direct regulation of PTEN and the PI3K/AKT/mTOR signaling pathway. GRHL3 is highly expressed in all tissues derived from the surface ectoderm, including the oral cavity, raising a question about its potential role in suppression of head and neck squamous cell carcinoma (HNSCC). We explored the tumor suppressor role of Grhl3 in HNSCC using a conditional knockout (Grhl3 (∆/-) /K14Cre (+) ) mouse line (n = 26) exposed to an oral chemical carcinogen. We defined the proto-oncogenic pathway activated in the HNSCC derived from these mice and assessed it in primary human HNSCC samples, normal oral epithelial cell lines carrying shRNA to GRHL3, and human HNSCC cell lines. Data were analyzed with two-sided chi square and Student's t tests. Deletion of Grhl3 in oral epithelium in mice did not perturb PTEN/PI3K/AKT/mTOR signaling, but instead evoked loss of GSK3B expression, resulting in stabilization and accumulation of c-MYC and aggressive HNSCC. This molecular signature was also evident in a subset of primary human HNSCC and HNSCC cell lines. Loss of Gsk3b in mice, independent of Grhl3, predisposed to chemical-induced HNSCC. Restoration of GSK3B expression blocked proliferation of normal oral epithelial cell lines carrying shRNA to GRHL3 (cell no., Day 8: Scramble ctl, 616±21.8 x 10(3) vs GRHL3-kd, 1194±44 X 10(3), P < .001; GRHL3-kd vs GRHL3-kd + GSK3B, 800±98.84 X 10(3), P = .003) and human HNSCC cells. We defined a novel molecular signature in mammalian HNSCC, suggesting new treatment strategies targeting the GRHL3/GSK3B/c-MYC proto-oncogenic network. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  8. Regulation of expression of the c-sis proto-oncogene

    Energy Technology Data Exchange (ETDEWEB)

    Ratner, L. (Washington Univ., St. Louis, MO (USA))

    1989-06-12

    Regulation of expression of platelet derived growth factor polypeptide B encoded by the c-sis proto-oncogene is important in a number of physiological and pathological conditions. Sequences in the 1,028 nucleotide long 5{prime} untranslated region of the c-sis mRNA were found to inhibit protein synthesis. The inhibition is relieved by deletion of nucleotides 154-378 or 398-475. Sequences within 375 nucleotides upstream of the RNA initiation sites are important for transcriptional activity. Sequences in two portions of this region, between {minus}375 and {minus}235 nucleotides and between {minus}235 and {minus}99 nucleotides relative to the RNA CAP site are important for full activity. A transcriptional enhancer activity is demonstrated by its ability to increase the activity of the human T lymphotropic virus type (HTLV) I promoter at a distance and in an orientation-independent manner. Furthermore, sequences upstream of the c-sis RNA CAP site respond to the HTLV I transactivator protein to increase RNA synthesis from either the c-sis or HTLV I promoter.

  9. Unexpected functional similarities between gatekeeper tumour suppressor genes and proto-oncogenes revealed by systems biology.

    Science.gov (United States)

    Zhao, Yongzhong; Epstein, Richard J

    2011-05-01

    Familial tumor suppressor genes comprise two subgroups: caretaker genes (CTs) that repair DNA, and gatekeeper genes (GKs) that trigger cell death. Since GKs may also induce cell cycle delay and thus enhance cell survival by facilitating DNA repair, we hypothesized that the prosurvival phenotype of GKs could be selected during cancer progression, and we used a multivariable systems biology approach to test this. We performed multidimensional data analysis, non-negative matrix factorization and logistic regression to compare the features of GKs with those of their putative antagonists, the proto-oncogenes (POs), as well as with control groups of CTs and functionally unrelated congenital heart disease genes (HDs). GKs and POs closely resemble each other, but not CTs or HDs, in terms of gene structure (Pexpression level and breadth (Pimplied suggest a common functional attribute that is strongly negatively selected-that is, a shared phenotype that enhances cell survival. The counterintuitive finding of similar evolutionary pressures affecting GKs and POs raises an intriguing possibility: namely, that cancer microevolution is accelerated by an epistatic cascade in which upstream suppressor gene defects subvert the normal bifunctionality of wild-type GKs by constitutively shifting the phenotype away from apoptosis towards survival. If correct, this interpretation would explain the hitherto unexplained phenomenon of frequent wild-type GK (for example, p53) overexpression in tumors.

  10. A novel form of the RelA nuclear factor kappaB subunit is induced by and forms a complex with the proto-oncogene c-Myc.

    Science.gov (United States)

    Chapman, Neil R; Webster, Gill A; Gillespie, Peter J; Wilson, Brian J; Crouch, Dorothy H; Perkins, Neil D

    2002-01-01

    Members of both Myc and nuclear factor kappaB (NF-kappaB) families of transcription factors are found overexpressed or inappropriately activated in many forms of human cancer. Furthermore, NF-kappaB can induce c-Myc gene expression, suggesting that the activities of these factors are functionally linked. We have discovered that both c-Myc and v-Myc can induce a previously undescribed, truncated form of the RelA(p65) NF-kappaB subunit, RelA(p37). RelA(p37) encodes the N-terminal DNA binding and dimerization domain of RelA(p65) and would be expected to function as a trans-dominant negative inhibitor of NF-kappaB. Surprisingly, we found that RelA(p37) no longer binds to kappaB elements. This result is explained, however, by the observation that RelA(p37), but not RelA(p65), forms a high-molecular-mass complex with c-Myc. These results demonstrate a previously unknown functional and physical interaction between RelA and c-Myc with many significant implications for our understanding of the role that both proteins play in the molecular events underlying tumourigenesis. PMID:12027803

  11. A germline RET proto-oncogene mutation in multiple members of an ...

    African Journals Online (AJOL)

    Background: Multiple endocrine neoplasia type 2A (MEN2A) is a rare cancer associated-syndrome, inherited in an autosomal dominant fashion and caused by germline mutation in RET proto-oncogene. Clinical diagnosis depends on the manifestation of two or more certain endocrine tumors in an individual, such as ...

  12. Expression of proto-oncogene KIT is up-regulated in subset of human meningiomas

    Directory of Open Access Journals (Sweden)

    Saini Masum

    2012-06-01

    Full Text Available Abstract Background KIT is a proto-oncogene involved in diverse neoplastic processes. Aberrant kinase activity of the KIT receptor has been targeted by tyrosine kinase inhibitor (TKI therapy in different neoplasias. In all the earlier studies, KIT expression was reported to be absent in meningiomas. However, we observed KIT mRNA expression in some meningioma cases. This prompted us to undertake its detailed analyses in meningioma tissues resected during 2008–2009. Methods Tumor tissues and matched peripheral blood samples collected from meningioma patients were used for detailed molecular analyses. KIT expression was ascertained immunohistochemically and validated by immunoblotting. KIT and KITLG transcript levels were discerned by reverse transcription quantitative real-time PCR (RT-qPCR. Similarly, KIT amplification and allele loss were assessed by quantitative real-time (qPCR and validated by fluorescence in situ hybridization (FISH on the neoplastic tissues. Possible alterations of the gene at the nucleotide level were analyzed by sequencing. Results Contrary to earlier reports, KIT expression, was detected immunohistochemically in 20.6% meningioma cases (n = 34. Receptor (KIT and ligand (KITLG transcripts monitored by RT-qPCR were found to co-express (p = 0.048 in most of the KIT immunopositive tumors. 1/7 KIT positive meningiomas showed allele loss corroborated by reduced FISH signal in the corresponding neoplastic tissue. Sequence analysis of KIT showed M541L substitution in exon 10, in one of the immunopositive cases. However, its biological consequence remains to be uncovered. Conclusions This study clearly demonstrates KIT over-expression in the human meningiomas. The data suggest that up-regulated KIT transcription (p  0.05, is a likely mechanism responsible for altered KIT expression. Thus, KIT is a potential candidate for detailed investigation in the context of meningioma pathogenesis.

  13. Expression of proto-oncogene KIT is up-regulated in subset of human meningiomas

    International Nuclear Information System (INIS)

    Saini, Masum; Jha, Ajaya Nand; Abrari, Andleeb; Ali, Sher

    2012-01-01

    KIT is a proto-oncogene involved in diverse neoplastic processes. Aberrant kinase activity of the KIT receptor has been targeted by tyrosine kinase inhibitor (TKI) therapy in different neoplasias. In all the earlier studies, KIT expression was reported to be absent in meningiomas. However, we observed KIT mRNA expression in some meningioma cases. This prompted us to undertake its detailed analyses in meningioma tissues resected during 2008–2009. Tumor tissues and matched peripheral blood samples collected from meningioma patients were used for detailed molecular analyses. KIT expression was ascertained immunohistochemically and validated by immunoblotting. KIT and KITLG transcript levels were discerned by reverse transcription quantitative real-time PCR (RT-qPCR). Similarly, KIT amplification and allele loss were assessed by quantitative real-time (qPCR) and validated by fluorescence in situ hybridization (FISH) on the neoplastic tissues. Possible alterations of the gene at the nucleotide level were analyzed by sequencing. Contrary to earlier reports, KIT expression, was detected immunohistochemically in 20.6% meningioma cases (n = 34). Receptor (KIT) and ligand (KITLG) transcripts monitored by RT-qPCR were found to co-express (p = 0.048) in most of the KIT immunopositive tumors. 1/7 KIT positive meningiomas showed allele loss corroborated by reduced FISH signal in the corresponding neoplastic tissue. Sequence analysis of KIT showed M541L substitution in exon 10, in one of the immunopositive cases. However, its biological consequence remains to be uncovered. This study clearly demonstrates KIT over-expression in the human meningiomas. The data suggest that up-regulated KIT transcription (p < 0.001), instead of gene amplification (p > 0.05), is a likely mechanism responsible for altered KIT expression. Thus, KIT is a potential candidate for detailed investigation in the context of meningioma pathogenesis

  14. The fps/fes proto-oncogene regulates hematopoietic lineage output.

    Science.gov (United States)

    Sangrar, Waheed; Gao, Yan; Zirngibl, Ralph A; Scott, Michelle L; Greer, Peter A

    2003-12-01

    The fps/fes proto-oncogene is abundantly expressed in myeloid cells, and the Fps/Fes cytoplasmic protein-tyrosine kinase is implicated in signaling downstream from hematopoietic cytokines, including interleukin-3 (IL-3), granulocyte-macrophage colony-stimulating factor (GM-CSF), and erythropoietin (EPO). Studies using leukemic cell lines have previously suggested that Fps/Fes contributes to granulomonocytic differentiation, and that it might play a more selective role in promoting survival and differentiation along the monocytic pathway. In this study we have used a genetic approach to explore the role of Fps/Fes in hematopoiesis. We used transgenic mice that tissue-specifically express a mutant human fps/fes transgene (fps(MF)) that was engineered to encode Fps/Fes kinase that is activated through N-terminal myristoylation (MFps). Hematopoietic function was assessed using lineage analysis, hematopoietic progenitor cell colony-forming assays, and biochemical approaches. fps(MF) transgenic mice displayed a skewed hematopoietic output reflected by increased numbers of circulating granulocytic and monocytic cells and a corresponding decrease in lymphoid cells. Bone marrow colony assays of progenitor cells revealed a significant increase in the number of both granulomonocytic and multi-lineage progenitors. A molecular analysis of signaling in mature monocytic cells showed that MFps promoted GM-CSF-induced STAT3, STAT5, and ERK1/2 activation. These observations support a role for Fps/Fes in signaling pathways that contribute to lineage determination at the level of multi-lineage hematopoietic progenitors as well as the more committed granulomonocytic progenitors.

  15. Proto-oncogene expression: a predictive assay for radiation biodosimetry applications

    Energy Technology Data Exchange (ETDEWEB)

    Miller, A.C.; Luo, L.; Chin, W.K.; Director-Myska, A.E.; Prasanna, P.G.S.; Blakely, W.F

    2002-07-01

    Using a model system of in vitro human peripheral blood lymphocytes, the effect of low-dose (0.25 to 1.50 Gy) 250-kV{sub p} X ray radiation (1 Gy.min{sup -1}) on the expression of several proto-oncogenes was examined (c-Haras, c-src, c-met, c-jun, c-fos, and c-myc) and {beta}-actin from 0.25 to 17 h post-radiation. RNA was extracted from cells harvested at various times after exposure and examined for levels of particular mRNAs by northern blot hybridisation. A progressive time- and dose-dependent increase in mRNA levels was observed for c-Haras mRNA, while the other proto-oncogenes (c-src, c-met, c-fos, c-jun, and c-myc) examined were variable during the same time period. {beta}-actin levels were initially decreased but at 17 h post-radiation had returned to control levels. A comparison of the rate of c-Haras transcription at 5 and 17 h post-irradiation revealed that c-Haras transcription was higher at 5 h than at 17 h. These findings suggest that the level of specific proto-oncogene expression, particularly c-Haras, may be useful early diagnostic molecular biomarkers for biodosimetry applications. The use of real-time PCR technologies to quantify gene expression changes will also be discussed. (author)

  16. Epidermal Growth Factor Receptor in Pancreatic Cancer

    International Nuclear Information System (INIS)

    Oliveira-Cunha, Melissa; Newman, William G.; Siriwardena, Ajith K.

    2011-01-01

    Pancreatic cancer is the fourth leading cause of cancer related death. The difficulty in detecting pancreatic cancer at an early stage, aggressiveness and the lack of effective therapy all contribute to the high mortality. Epidermal growth factor receptor (EGFR) is a transmembrane glycoprotein, which is expressed in normal human tissues. It is a member of the tyrosine kinase family of growth factors receptors and is encoded by proto-oncogenes. Several studies have demonstrated that EGFR is over-expressed in pancreatic cancer. Over-expression correlates with more advanced disease, poor survival and the presence of metastases. Therefore, inhibition of the EGFR signaling pathway is an attractive therapeutic target. Although several combinations of EGFR inhibitors with chemotherapy demonstrate inhibition of tumor-induced angiogenesis, tumor cell apoptosis and regression in xenograft models, these benefits remain to be confirmed. Multimodality treatment incorporating EGFR-inhibition is emerging as a novel strategy in the treatment of pancreatic cancer

  17. The SKI proto-oncogene enhances the in vivo repopulation of hematopoietic stem cells and causes myeloproliferative disease.

    Science.gov (United States)

    Singbrant, Sofie; Wall, Meaghan; Moody, Jennifer; Karlsson, Göran; Chalk, Alistair M; Liddicoat, Brian; Russell, Megan R; Walkley, Carl R; Karlsson, Stefan

    2014-04-01

    The proto-oncogene SKI is highly expressed in human myeloid leukemia and also in murine hematopoietic stem cells. However, its operative relevance in these cells remains elusive. We have over-expressed SKI to define its intrinsic role in hematopoiesis and myeloid neoplasms, which resulted in a robust competitive advantage upon transplantation, a complete dominance of the stem and progenitor compartments, and a marked enhancement of myeloid differentiation at the expense of other lineages. Accordingly, enforced expression of SKI induced a gene signature associated with hematopoietic stem cells and myeloid differentiation, as well as hepatocyte growth factor signaling. Here we demonstrate that, in contrast to what has generally been assumed, the significant impact of SKI on hematopoiesis is independent of its ability to inhibit TGF-beta signaling. Instead, myeloid progenitors expressing SKI are partially dependent on functional hepatocyte growth factor signaling. Collectively our results demonstrate that SKI is an important regulator of hematopoietic stem cell activity and its overexpression leads to myeloproliferative disease.

  18. Aubergine and piRNAs promote germline stem cell self-renewal by repressing the proto-oncogene Cbl.

    Science.gov (United States)

    Rojas-Ríos, Patricia; Chartier, Aymeric; Pierson, Stéphanie; Simonelig, Martine

    2017-11-02

    PIWI proteins play essential roles in germ cells and stem cell lineages. In Drosophila , Piwi is required in somatic niche cells and germline stem cells (GSCs) to support GSC self-renewal and differentiation. Whether and how other PIWI proteins are involved in GSC biology remains unknown. Here, we show that Aubergine (Aub), another PIWI protein, is intrinsically required in GSCs for their self-renewal and differentiation. Aub needs to be loaded with piRNAs to control GSC self-renewal and acts through direct mRNA regulation. We identify the Cbl proto-oncogene, a regulator of mammalian hematopoietic stem cells, as a novel GSC differentiation factor. Aub stimulates GSC self-renewal by repressing Cbl mRNA translation and does so in part through recruitment of the CCR4-NOT complex. This study reveals the role of piRNAs and PIWI proteins in controlling stem cell homeostasis via translational repression and highlights piRNAs as major post-transcriptional regulators in key developmental decisions. © 2017 The Authors. Published under the terms of the CC BY 4.0 license.

  19. Effect of ionizing radiation on the biological activity of activated oncogenes and dormant proto-oncogenes

    International Nuclear Information System (INIS)

    Angenent, G.C.; Berg, K.J. van den.

    1984-01-01

    The authors have studied the effect of ionizing radiation on the cloned human activated Ha-ras oncogene, on the Ha-ras gene in integrated form and on the dormant proto-oncogene murine c-mos using the NIH/3T3 transfection system. NIH/3T3 cells were transfected with DNA from the plasmid pT24 carrying the cloned Ha-ras oncogene of the T24 bladder carcinoma cell line. Various individual foci which developed were injected into nude mice. DNA was isolated from tumours, digested with the restriction enzyme Bam HI, electrophoresed on agarose and blotted onto nitrocellulose filter according to Southern. Hybridization with a pT24 probe showed that all the primary foci of transformed cells contained various fragments of the pT24 plasmid indicating that fibroblast transformation had been induced by introduction of the Ha-ras oncogene. (Auth.)

  20. Targeting of the tumor suppressor GRHL3 by a miR-21-dependent proto-oncogenic network results in PTEN loss and tumorigenesis.

    Science.gov (United States)

    Darido, Charbel; Georgy, Smitha R; Wilanowski, Tomasz; Dworkin, Sebastian; Auden, Alana; Zhao, Quan; Rank, Gerhard; Srivastava, Seema; Finlay, Moira J; Papenfuss, Anthony T; Pandolfi, Pier Paolo; Pearson, Richard B; Jane, Stephen M

    2011-11-15

    Despite its prevalence, the molecular basis of squamous cell carcinoma (SCC) remains poorly understood. Here, we identify the developmental transcription factor Grhl3 as a potent tumor suppressor of SCC in mice, and demonstrate that targeting of Grhl3 by a miR-21-dependent proto-oncogenic network underpins SCC in humans. Deletion of Grhl3 in adult epidermis evokes loss of expression of PTEN, a direct GRHL3 target, resulting in aggressive SCC induced by activation of PI3K/AKT/mTOR signaling. Restoration of Pten expression completely abrogates SCC formation. Reduced levels of GRHL3 and PTEN are evident in human skin, and head and neck SCC, associated with increased expression of miR-21, which targets both tumor suppressors. Our data define the GRHL3-PTEN axis as a critical tumor suppressor pathway in SCC. 2011 Elsevier Inc. All rights reserved.

  1. Proto-oncogene FBI-1 (Pokemon) and SREBP-1 Synergistically Activate Transcription of Fatty-acid Synthase Gene (FASN)*S⃞

    Science.gov (United States)

    Choi, Won-Il; Jeon, Bu-Nam; Park, Hyejin; Yoo, Jung-Yoon; Kim, Yeon-Sook; Koh, Dong-In; Kim, Myung-Hwa; Kim, Yu-Ri; Lee, Choong-Eun; Kim, Kyung-Sup; Osborne, Timothy F.; Hur, Man-Wook

    2008-01-01

    FBI-1 (Pokemon/ZBTB7A) is a proto-oncogenic transcription factor of the BTB/POZ (bric-à-brac, tramtrack, and broad complex and pox virus zinc finger) domain family. Recent evidence suggested that FBI-1 might be involved in adipogenic gene expression. Coincidentally, expression of FBI-1 and fatty-acid synthase (FASN) genes are often increased in cancer and immortalized cells. Both FBI-1 and FASN are important in cancer cell proliferation. SREBP-1 is a major regulator of many adipogenic genes, and FBI-1 and SREBP-1 (sterol-responsive element (SRE)-binding protein 1) interact with each other directly via their DNA binding domains. FBI-1 enhanced the transcriptional activation of SREBP-1 on responsive promoters, pGL2-6x(SRE)-Luc and FASN gene. FBI-1 and SREBP-1 synergistically activate transcription of the FASN gene by acting on the proximal GC-box and SRE/E-box. FBI-1, Sp1, and SREBP-1 can bind to all three SRE, GC-box, and SRE/E-box. Binding competition among the three transcription factors on the GC-box and SRE/E-box appears important in the transcription regulation. FBI-1 is apparently changing the binding pattern of Sp1 and SREBP-1 on the two elements in the presence of induced SREBP-1 and drives more Sp1 binding to the proximal promoter with less of an effect on SREBP-1 binding. The changes induced by FBI-1 appear critical in the synergistic transcription activation. The molecular mechanism revealed provides insight into how proto-oncogene FBI-1 may attack the cellular regulatory mechanism of FASN gene expression to provide more phospholipid membrane components needed for rapid cancer cell proliferation. PMID:18682402

  2. Expression of the Pokemon proto-oncogene in nasopharyngeal carcinoma cell lines and tissues.

    Science.gov (United States)

    Jiao, Wei; Liu, Fei; Tang, Feng-Zhu; Lan, Jiao; Xiao, Rui-Ping; Chen, Xing-Zhou; Ye, Hui-Lan; Cai, Yong-Lin

    2013-01-01

    To study the differentiated expression of the proto-oncogene Pokemon in nasopharyngeal carcinoma (NPC) cell lines and tissues, mRNA and protein expression levels of CNE1, CNE2, CNE3 and C666-1 were detected separately by reverse transcription polymerase chain reaction (RT-PCR), real-time PCR and Western-blotting. The immortalized nasopharyngeal epithelial cell line NP69 was used as a control. The Pokemon protein expression level in biopsy specimens from chronic rhinitis patients and undifferentiated non keratinizing NPC patients was determined by Western-blotting and arranged from high to low: C666-1>CNE1>CNE2> CNE3>NP69. The Pokemon mRNA expression level was also arranged from high to low: CNE1>CNE2>NP69>C666-1>CNE3. Pokemon expression of NP69 and C666-1 obviously varied from mRNA to protein. The Pokemon protein level of NPC biopsy specimens was obviously higher than in chronic rhinitis. The data suggest that high Pokemon protein expression is closely associated with undifferentiated non-keratinizing NPC and may provide useful information for NPC molecular target therapy.

  3. The crucial role of the proto-oncogene c-mos in regulation of oocyte maturation

    Directory of Open Access Journals (Sweden)

    Irena Jałocha

    2010-12-01

    Full Text Available Meiosis arrest before fertilization is a common and unique feature of oogenesis in many animal species. On account of the unclear biological significance of meiosis arrest at various stages and for different durations in different animal species, this process and its regulation are the subject of many scientific studies. Studies on the development of ovarian teratomas proved to be helpful in defining the role of particular genes and biochemical cycles in control of the cell cycle in animals. These benign tumors are a valuable source of information on oocyte maturation. The [i]c-mos[/i] proto-oncogene, which is specifically expressed in female and male germ cells, plays a crucial role in control of meiotic cell division in mammals. Its product – Mos protein kinase – acting through mitogen-activated protein kinases (MAPKs regulates critical cellular functions required for homeostasis and decides about cell survival or apoptosis. The MAPK kinase kinase – MAPK kinase – MAPK (MKKK-MKK-MAPK phosphorelay system, in view of its role in cells, seems to be the ideal target for therapeutic intervention in cancer and other diseases. The recent research on human oocytes suggests that the basic mechanisms regulating various stages of oocyte maturation are similar to those described in animals.

  4. Primary structure of the human fgr proto-oncogene product p55/sup c-fgr/

    Energy Technology Data Exchange (ETDEWEB)

    Katamine, S.; Notario, V.; Rao, C.D.; Miki, T.; Cheah, M.S.C.; Tronick, S.R.; Robbins, K.C.

    1988-01-01

    Normal human c-fgr cDNA clones were constructed by using normal peripheral blood mononuclear cell mRNA as a template. Nucleotide sequence analysis of two such clones revealed a 1,587-base-pair-long open reading frame which predicted the primary amino acid sequence of the c-fgr translational product. Homology of this protein with the v-fgr translational product stretched from codons 128 to 516, where 32 differences among 388 codons were observed. Sequence similarity with human c-src, c-yes, and fyn translations products began at amino acid position 76 of the predicted c-fgr protein and extended nearly to its C-terminus. In contrast, the stretch of 75 amino acids at the N-terminus demonstrated a greatly reduced degree of relatedness to these same proteins. To verify the deduced amino acid sequence, antibodies were prepared against peptides representing amino- and carboxy-terminal regions of the predicted c-fgr translational product. Both antibodies specifically recognized a 55-kilodalton protein expressed in COS-1 cells transfected with a c-fgr cDNA expression plasmid. Moreover, the same protein was immunoprecipitated from an Epstein-Barr virus-infected Burkitt's lymphoma cell line which expressed c-fgr mRNA but not in its uninfected fgr mRNA-negative counterpart. These findings identified the 55-kilodalton protein as the product of the human fgr proto-oncogene.

  5. Methamphetamine induces apoptosis in immortalized neural cells: protection by the proto-oncogene, bcl-2.

    Science.gov (United States)

    Cadet, J L; Ordonez, S V; Ordonez, J V

    1997-02-01

    Methamphetamine (METH) is an amphetamine analog that produces degeneration of the dopaminergic system in mammals. The neurotoxic effects of the drug are thought to be mediated by oxygen-based free radicals. In the present report, we have used immortalized neural cells obtained from rat mesencephalon in order to further assess the role of oxidative stress in METH-induced neurotoxicity. We thus tested if the anti-death proto-oncogene, bcl-2 could protect against METH-induced cytotoxicity. METH caused dose-dependent loss of cellular viability in control cells while bcl-2-expressing cells were protected against these deleterious effects. Using flow cytometry, immunofluorescent staining, and DNA electrophoresis, we also show that METH exposure can cause DNA strand breaks, chromatin condensation, nuclear fragmentation, and DNA laddering. All these changes were prevented by bcl-2 expression. These observations provide further support for the involvement of oxidative stress in the toxic effects of amphetamine analogs. They also document that METH-induced cytotoxicity is secondary to apoptosis. These findings may be of relevance to the cause(s) of Parkinson's disease which involves degeneration of the nigrostriatal dopaminergic pathway.

  6. Studies of the HER-2/neu proto-oncogene in human breast and ovarian cancer.

    Science.gov (United States)

    Slamon, D J; Godolphin, W; Jones, L A; Holt, J A; Wong, S G; Keith, D E; Levin, W J; Stuart, S G; Udove, J; Ullrich, A

    1989-05-12

    Carcinoma of the breast and ovary account for one-third of all cancers occurring in women and together are responsible for approximately one-quarter of cancer-related deaths in females. The HER-2/neu proto-oncogene is amplified in 25 to 30 percent of human primary breast cancers and this alteration is associated with disease behavior. In this report, several similarities were found in the biology of HER-2/neu in breast and ovarian cancer, including a similar incidence of amplification, a direct correlation between amplification and over-expression, evidence of tumors in which overexpression occurs without amplification, and the association between gene alteration and clinical outcome. A comprehensive study of the gene and its products (RNA and protein) was simultaneously performed on a large number of both tumor types. This analysis identified several potential shortcomings of the various methods used to evaluate HER-2/neu in these diseases (Southern, Northern, and Western blots, and immunohistochemistry) and provided information regarding considerations that should be addressed when studying a gene or gene product in human tissue. The data presented further support the concept that the HER-2/neu gene may be involved in the pathogenesis of some human cancers.

  7. Mutation and genomic amplification of the PIK3CA proto-oncogene in pituitary adenomas

    Energy Technology Data Exchange (ETDEWEB)

    Murat, C.B.; Braga, P.B.S.; Fortes, M.A.H.Z. [Laboratório de Endocrinologia Celular e Molecular (LIM-25), Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP (Brazil); Bronstein, M.D. [Unidade de Neuroendocrinologia, Serviço de Endocrinologia, Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP (Brazil); Corrêa-Giannella, M.L.C.; Giorgi, R.R. [Laboratório de Endocrinologia Celular e Molecular (LIM-25), Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP (Brazil)

    2012-07-13

    The tumorigenesis of pituitary adenomas is poorly understood. Mutations of the PIK3CA proto-oncogene, which encodes the p110-α catalytic subunit of PI3K, have been reported in various types of human cancers regarding the role of the gene in cell proliferation and survival through activation of the PI3K/Akt signaling pathway. Only one Chinese study described somatic mutations and amplification of the PIK3CA gene in a large series of pituitary adenomas. The aim of the present study was to determine genetic alterations of PIK3CA in a second series that consisted of 33 pituitary adenomas of different subtypes diagnosed by immunohistochemistry: 6 adrenocorticotropic hormone-secreting microadenomas, 5 growth hormone-secreting macroadenomas, 7 prolactin-secreting macroadenomas, and 15 nonfunctioning macroadenomas. Direct sequencing of exons 9 and 20 assessed by qPCR was employed to investigate the presence of mutations and genomic amplification defined as a copy number ≥4. Previously identified PIK3CA mutations (exon 20) were detected in four cases (12.1%). Interestingly, the Chinese study reported mutations only in invasive tumors, while we found a PIK3CA mutation in one noninvasive corticotroph microadenoma. PIK3CA amplification was observed in 21.2% (7/33) of the cases. This study demonstrates the presence of somatic mutations and amplifications of the PIK3CA gene in a second series of pituitary adenomas, corroborating the previously described involvement of the PI3K/Akt signaling pathway in the tumorigenic process of this gland.

  8. Mutation and genomic amplification of the PIK3CA proto-oncogene in pituitary adenomas

    International Nuclear Information System (INIS)

    Murat, C.B.; Braga, P.B.S.; Fortes, M.A.H.Z.; Bronstein, M.D.; Corrêa-Giannella, M.L.C.; Giorgi, R.R.

    2012-01-01

    The tumorigenesis of pituitary adenomas is poorly understood. Mutations of the PIK3CA proto-oncogene, which encodes the p110-α catalytic subunit of PI3K, have been reported in various types of human cancers regarding the role of the gene in cell proliferation and survival through activation of the PI3K/Akt signaling pathway. Only one Chinese study described somatic mutations and amplification of the PIK3CA gene in a large series of pituitary adenomas. The aim of the present study was to determine genetic alterations of PIK3CA in a second series that consisted of 33 pituitary adenomas of different subtypes diagnosed by immunohistochemistry: 6 adrenocorticotropic hormone-secreting microadenomas, 5 growth hormone-secreting macroadenomas, 7 prolactin-secreting macroadenomas, and 15 nonfunctioning macroadenomas. Direct sequencing of exons 9 and 20 assessed by qPCR was employed to investigate the presence of mutations and genomic amplification defined as a copy number ≥4. Previously identified PIK3CA mutations (exon 20) were detected in four cases (12.1%). Interestingly, the Chinese study reported mutations only in invasive tumors, while we found a PIK3CA mutation in one noninvasive corticotroph microadenoma. PIK3CA amplification was observed in 21.2% (7/33) of the cases. This study demonstrates the presence of somatic mutations and amplifications of the PIK3CA gene in a second series of pituitary adenomas, corroborating the previously described involvement of the PI3K/Akt signaling pathway in the tumorigenic process of this gland

  9. Formaldehyde-induced histone H3 phosphorylation via JNK and the expression of proto-oncogenes

    International Nuclear Information System (INIS)

    Yoshida, Ikuma; Ibuki, Yuko

    2014-01-01

    Graphical abstract: - Highlights: • Formaldehyde modified histones. • The phosphorylation of H3S10 was increased at the promoter regions of proto-oncogenes. • The phosphorylation of H2AXS139 was attributed to FA-induced DNA damage. • The FA-induced initiation and promotion of cancer could be judged by these modifications. - Abstract: Formaldehyde (FA) is a very reactive compound that forms DNA adducts and DNA-protein crosslinks, which are known to contribute to FA-induced mutations and carcinogenesis. Post-translational modifications to histones have recently attracted attention due to their link with cancer. In the present study, we examined histone modifications following a treatment with FA. FA significantly phosphorylated histone H3 at serine 10 (H3S10), and at serine 28 (H3S28), the time-course of which was similar to the phosphorylation of H2AX at serine 139 (γ-H2AX), a marker of DNA double strand breaks. The temporal deacetylation of H3 was observed due to the reaction of FA with the lysine residues of histones. The phosphorylation mechanism was then analyzed by focusing on H3S10. The nuclear distribution of the phosphorylation of H3S10 and γ-H2AX did not overlap, and the phosphorylation of H3S10 could not be suppressed with an inhibitor of ATM/ATR, suggesting that the phosphorylation of H3S10 was independent of the DNA damage response. ERK and JNK in the MAPK pathways were phosphorylated by the treatment with FA, in which the JNK pathway was the main target for phosphorylation. The phosphorylation of H3S10 increased at the promoter regions of c-fos and c-jun, indicating a relationship between FA-induced tumor promotion activity and phosphorylation of H3S10. These results suggested that FA both initiates and promotes cancer, as judged by an analysis of histone modifications

  10. Formaldehyde-induced histone H3 phosphorylation via JNK and the expression of proto-oncogenes

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, Ikuma; Ibuki, Yuko, E-mail: ibuki@u-shizuoka-ken.ac.jp

    2014-12-15

    Graphical abstract: - Highlights: • Formaldehyde modified histones. • The phosphorylation of H3S10 was increased at the promoter regions of proto-oncogenes. • The phosphorylation of H2AXS139 was attributed to FA-induced DNA damage. • The FA-induced initiation and promotion of cancer could be judged by these modifications. - Abstract: Formaldehyde (FA) is a very reactive compound that forms DNA adducts and DNA-protein crosslinks, which are known to contribute to FA-induced mutations and carcinogenesis. Post-translational modifications to histones have recently attracted attention due to their link with cancer. In the present study, we examined histone modifications following a treatment with FA. FA significantly phosphorylated histone H3 at serine 10 (H3S10), and at serine 28 (H3S28), the time-course of which was similar to the phosphorylation of H2AX at serine 139 (γ-H2AX), a marker of DNA double strand breaks. The temporal deacetylation of H3 was observed due to the reaction of FA with the lysine residues of histones. The phosphorylation mechanism was then analyzed by focusing on H3S10. The nuclear distribution of the phosphorylation of H3S10 and γ-H2AX did not overlap, and the phosphorylation of H3S10 could not be suppressed with an inhibitor of ATM/ATR, suggesting that the phosphorylation of H3S10 was independent of the DNA damage response. ERK and JNK in the MAPK pathways were phosphorylated by the treatment with FA, in which the JNK pathway was the main target for phosphorylation. The phosphorylation of H3S10 increased at the promoter regions of c-fos and c-jun, indicating a relationship between FA-induced tumor promotion activity and phosphorylation of H3S10. These results suggested that FA both initiates and promotes cancer, as judged by an analysis of histone modifications.

  11. Expression of the proto-oncogene Pokemon in colorectal cancer--inhibitory effects of an siRNA.

    Science.gov (United States)

    Zhao, Gan-Ting; Yang, Li-Juan; Li, Xi-Xia; Cui, Hui-Lin; Guo, Rui

    2013-01-01

    This study aimed to investigate expression of the proto-oncogene POK erythroid myeloid ontogenic factor (Pokemon) in colorectal cancer (CRC), and assess inhibitory effects of a small interference RNA (siRNA) expression vector in SW480 and SW620 cells. Semi-quantitative reverse transcription-polymerase chain reaction (PCR) and immunohistochemistry were performed to determine mRNA and protein expression levels of Pokemon in CRC tissues. Indirect immunofluorescence staining was applied to investigate the location of Pokemon in SW480 and SW620 cells. The siRNA expression vectors that were constructed to express a short hairpin RNA against Pokemon were transfected to the SW480 and SW620 cells with a liposome. Expression levels of Pokemon mRNA and protein were examined by real-time quantitative-fluorescent PCR and western blot analysis. The effects of Pokemon silencing on proliferation of SW480 and SW620 cells were evaluated with reference to growth curves with MTT assays. The mRNA expression level of Pokemon in tumor tissues (0.845 ± 0.344) was significantly higher than that in adjacent tumor specimens (0.321 ± 0.197). The positive expression ratio of Pokemon protein in CRC (87.0%) was significantly higher than that in the adjacent tissues (19.6%). Strong fluorescence staining of Pokemon protein was observed in the cytoplasm of the SW480 and SW620 cells. The inhibition ratios of Pokemon mRNA and protein in the SW480 cells were 83.1% and 73.5% at 48 and 72 h, respectively, compared with those of the negative control cells with the siRNA. In the SW620 cells, the inhibition ratios of Pokemon mRNA and protein were 76.3% and 68.7% at 48 and 72 h, respectively. MTT showed that Pokemon gene silencing inhibited the proliferation of SW480 and SW620 cells. Overexpression of Pokemon in CRC may have a function in carcinogenesis and progression. siRNA expression vectors could effectively inhibit mRNA and protein expression of Pokemon in SW480 and SW620 cells, thereby reducing

  12. The protein encoded by the proto-oncogene DEK changes the topology of chromatin and reduces the efficiency of DNA replication in a chromatin-specific manner

    DEFF Research Database (Denmark)

    Alexiadis, V; Waldmann, T; Andersen, Jens S.

    2000-01-01

    The structure of chromatin regulates the genetic activity of the underlying DNA sequence. We report here that the protein encoded by the proto-oncogene DEK, which is involved in acute myelogenous leukemia, induces alterations of the superhelical density of DNA in chromatin. The change in topology...

  13. Plasma levels of calcitonin in medullary thyroid carcinoma patients with and without the RET proto-oncogene mutations in exons 10 and 11

    Directory of Open Access Journals (Sweden)

    Samira Ehyayi

    2017-09-01

    Conclusion: Routine measurement of calcitonin has been investigated as a screening method for the diagnosis of medullary thyroid carcinoma patients. Nevertheless, additional data are required to definitely support routine measurement of calcitonin due to the role of RET proto-oncogene.

  14. Retroviruses Hijack Chromatin Loops to Drive Oncogene Expression and Highlight the Chromatin Architecture around Proto-Oncogenic Loci

    Science.gov (United States)

    Pattison, Jillian M.; Wright, Jason B.; Cole, Michael D.

    2015-01-01

    The majority of the genome consists of intergenic and non-coding DNA sequences shown to play a major role in different gene regulatory networks. However, the specific potency of these distal elements as well as how these regions exert function across large genomic distances remains unclear. To address these unresolved issues, we closely examined the chromatin architecture around proto-oncogenic loci in the mouse and human genomes to demonstrate a functional role for chromatin looping in distal gene regulation. Using cell culture models, we show that tumorigenic retroviral integration sites within the mouse genome occur near existing large chromatin loops and that this chromatin architecture is maintained within the human genome as well. Significantly, as mutagenesis screens are not feasible in humans, we demonstrate a way to leverage existing screens in mice to identify disease relevant human enhancers and expose novel disease mechanisms. For instance, we characterize the epigenetic landscape upstream of the human Cyclin D1 locus to find multiple distal interactions that contribute to the complex cis-regulation of this cell cycle gene. Furthermore, we characterize a novel distal interaction upstream of the Cyclin D1 gene which provides mechanistic evidence for the abundant overexpression of Cyclin D1 occurring in multiple myeloma cells harboring a pathogenic translocation event. Through use of mapped retroviral integrations and translocation breakpoints, our studies highlight the importance of chromatin looping in oncogene expression, elucidate the epigenetic mechanisms crucial for distal cis-regulation, and in one particular instance, explain how a translocation event drives tumorigenesis through upregulation of a proto-oncogene. PMID:25799187

  15. Inhibition of carcinogen induced c-Ha-ras and c-fos proto-oncogenes expression by dietary curcumin

    Directory of Open Access Journals (Sweden)

    Lipigorngoson Suwiwek

    2001-01-01

    Full Text Available Abstract Background We investigated the chemopreventive action of dietary curcumin on 7,12-dimethylbenz(aanthracene (DMBA-initiated and 12,0-tetradecanoylphorbol-13-acetate (TPA-promoted skin tumor formation in Swiss albino mice. Curcumin, a yellow coloring matter isolated from roots of Curcuma longa Linn, is a phenolic compound possessing antioxidant, free radical scavenger, and antiinflammatory properties. It has been shown by previously reported work that TPA-induced skin tumors were inhibited by topical application of curcumin, and curcumin has been shown to inhibit a variety of biological activities of TPA. Topical application of curcumin was reported to inhibit TPA-induced c-fos, c-jun and c-myc gene expression in mouse skin. This paper reports the effects of orally administered curcumin, which was consumed as a dietary component at concentrations of 0.2 % or 1 %, in ad libitum feeding. Results Animals in which tumors had been initiated with DMBA and promoted with TPA experienced significantly fewer tumors and less tumor volume if they ingested either 0.2% or 1% curcumin diets. Also, the dietary consumption of curcumin resulted in a significantly decreased expression of ras and fos proto-oncogenes in the tumorous skin, as measured by enhanced chemiluminesence Western blotting detection system (Amersham. Conclusions Whereas earlier work demonstrated that topical application of curcumin to mouse skin inhibited TPA-induced expression of c-fos, c-jun and c-myc oncogenes, our results are the first to show that orally consumed curcumin significantly inhibited DMBA- and TPA-induced ras and fos gene expression in mouse skin.

  16. Inhibition of carcinogen induced c-Ha-ras and c-fos proto-oncogenes expression by dietary curcumin

    International Nuclear Information System (INIS)

    Limtrakul, Porn-ngarm; Anuchapreeda, Songyot; Lipigorngoson, Suwiwek; Dunn, Floyd W

    2001-01-01

    We investigated the chemopreventive action of dietary curcumin on 7,12-dimethylbenz(a)anthracene (DMBA)-initiated and 12,0-tetradecanoylphorbol-13-acetate (TPA)-promoted skin tumor formation in Swiss albino mice. Curcumin, a yellow coloring matter isolated from roots of Curcuma longa Linn, is a phenolic compound possessing antioxidant, free radical scavenger, and antiinflammatory properties. It has been shown by previously reported work that TPA-induced skin tumors were inhibited by topical application of curcumin, and curcumin has been shown to inhibit a variety of biological activities of TPA. Topical application of curcumin was reported to inhibit TPA-induced c-fos, c-jun and c-myc gene expression in mouse skin. This paper reports the effects of orally administered curcumin, which was consumed as a dietary component at concentrations of 0.2 % or 1 %, in ad libitum feeding. Animals in which tumors had been initiated with DMBA and promoted with TPA experienced significantly fewer tumors and less tumor volume if they ingested either 0.2% or 1% curcumin diets. Also, the dietary consumption of curcumin resulted in a significantly decreased expression of ras and fos proto-oncogenes in the tumorous skin, as measured by enhanced chemiluminesence Western blotting detection system (Amersham). Whereas earlier work demonstrated that topical application of curcumin to mouse skin inhibited TPA-induced expression of c-fos, c-jun and c-myc oncogenes, our results are the first to show that orally consumed curcumin significantly inhibited DMBA- and TPA-induced ras and fos gene expression in mouse skin

  17. Microsatellite instability and B-type Raf proto-oncogene mutation in colorectal cancer: Clinicopathological characteristics and effects on survival

    Directory of Open Access Journals (Sweden)

    Sebnem Batur

    2016-11-01

    Full Text Available Prognostic significance of microsatellite instability (MSI status and B-type Raf proto-oncogene (BRAF mutation in colorectal cancer is controversial. The aim of this study was to examine the clinical and pathological characteristics associated with microsatellite stability and the effect of MSI and BRAF mutation on the survival of patients with colorectal cancer. The study included 145 colorectal cancer cases. All the patients were examined for DNA mismatch repair (MMR proteins with an immunohistochemical method. Molecular assessment of MSI was available in a subset of 41 patients. In addition, BRAF mutation analysis was performed in 30 cases. Immunohistochemically, MMR deficiency was present in 28 (19.3% patients. Female gender (p = 0.001, lesion size ≥5 cm (p = 0.013, Crohn-like response (p = 0.035, and right-sided localization (p < 0.001 were significantly more frequent among MMR-deficient patients. The overall survival was 44.1 ± 5.1 months (95% confidence interval [CI], 33.7-54.4. Multivariate analyses identified only high tumor grade as an independent predictor of poor overall survival: odd ratio, 6.7 (95% CI 2.1-21.7, p = 0.002. In the subset of patients with available BRAF assessment (n = 30, a negative BRAF status was associated with better survival when compared to a positive BRAF status (36.7 ± 2.1 vs. 34.1 ± 7.2 months, p = 0.048. The sensitivity and specificity of the immunohistochemical method in predicting positive MSI status, with the molecular method as a reference, were 85.7% (95% CI: 56.2%-97.5% and 88.9% (95% CI: 69.7%-97.1%, respectively. BRAF appears to be a significant predictor of a worse outcome in patients with colorectal cancer. Further studies with a large spectrum of clinical and biological variables are warranted.

  18. Physiological Signaling and Structure of the HGF Receptor MET

    Directory of Open Access Journals (Sweden)

    Gianluca Baldanzi

    2014-12-01

    Full Text Available The “hepatocyte growth factor” also known as “scatter factor”, is a multifunctional cytokine with the peculiar ability of simultaneously triggering epithelial cell proliferation, movement and survival. The combination of those proprieties results in the induction of an epithelial to mesenchymal transition in target cells, fundamental for embryogenesis but also exploited by tumor cells during metastatization. The hepatocyte growth factor receptor, MET, is a proto-oncogene and a prototypical transmembrane tyrosine kinase receptor. Inhere we discuss the MET molecular structure and the hepatocyte growth factor driven physiological signaling which coordinates epithelial proliferation, motility and morphogenesis.

  19. Pokemon proto-oncogene in oral cancer: potential role in the early phase of tumorigenesis.

    Science.gov (United States)

    Sartini, D; Lo Muzio, L; Morganti, S; Pozzi, V; Di Ruscio, G; Rocchetti, R; Rubini, C; Santarelli, A; Emanuelli, M

    2015-05-01

    Oral squamous cell carcinoma (OSCC) represents about 90% of all oral neoplasms with a poor clinical prognosis. To improve survival of OSCC patients, it is fundamental to understand the basic molecular mechanisms characterizing oral carcinogenesis. Dysregulation of oncogenes and tumor suppressor genes seems to play a central role in tumorigenesis, including malignant transformation of the oral cavity. We analyzed the expression levels of the pro-oncogenic transcription factor Pokemon through real-time PCR, Western blot and immunohistochemistry in tumor, and normal oral tissue samples obtained from 22 patients with OSCC. The relationship between tumor characteristics and the level of Pokemon intratumor expression was also analyzed. Pokemon was significantly downregulated in OSCC. In particular, both mRNA and protein levels (tumor vs normal tissue) inversely correlated with histological grading, suggesting its potential role as a prognostic factor for OSCC. Moreover, a significant inverse correlation was found between Pokemon protein expression levels (OSCC vs normal oral mucosa) and tumor size, supporting the hypothesis that Pokemon could play an important role in the early phase of tumor expansion. This work shows that reduced expression of Pokemon is a peculiar feature of OSCC. Additional studies may establish the effective role of Pokemon in oral tumorigenesis. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  20. Enhanced sensitivity of the RET proto-oncogene to ionizing radiation in vitro.

    Science.gov (United States)

    Volpato, Claudia Béu; Martínez-Alfaro, Minerva; Corvi, Raffaella; Gabus, Coralie; Sauvaigo, Sylvie; Ferrari, Pietro; Bonora, Elena; De Grandi, Alessandro; Romeo, Giovanni

    2008-11-01

    Exposure to ionizing radiation is a well-known risk factor for a number of human cancers, including leukemia and thyroid cancer. It has been known for a long time that exposure of cells to radiation results in extensive DNA damage; however, a small number of studies have tried to explain the mechanisms of radiation-induced carcinogenesis. The high prevalence of RET/PTC rearrangements in patients who have received external radiation, and the evidence of in vitro induction of RET rearrangements in human cells, suggest an enhanced sensitivity of the RET genomic region to damage by ionizing radiation. To assess whether RET is indeed more sensitive to radiations than other genomic regions, we used a COMET assay coupled with fluorescence in situ hybridization, which allows the measurement of DNA fragmentation in defined genomic regions of single cells. We compared the initial DNA damage of the genomic regions of RET, CXCL12/SDF1, ABL, MYC, PLA2G2A, p53, and JAK2 induced by ionizing radiation in both a lymphoblastoid and a fetal thyroid cell line. In both cell lines, RET fragmentation was significantly higher than in other genomic regions. Moreover, a differential distribution of signals within the COMET was associated with a higher percentage of RET fragments in the tail. RET was more susceptible to fragmentation in the thyroid-derived cells than in lymphoblasts. This enhanced susceptibility of RET to ionizing radiation suggests the possibility of using it as a radiation exposure marker.

  1. Elevated expression of proto-oncogenes accompany enhanced induction of heat-shock genes after exposure of rat embryos in utero to ionizing irradiation

    International Nuclear Information System (INIS)

    Higo, H.; Lee, J.Y.; Satow, Y.; Higo, K.

    1989-01-01

    We have recently found that the effects of exposing rat embryos in utero to teratogens capable of producing cardiac anomalies were expressed later as enhanced induction of heat-shock proteins (hsp70 family) when embryonic hearts were cultured in vitro. However, it remained to be determined whether heat-shock proteins are induced in vivo after exposure to teratogens. The heat-shock response in some mammalian systems is known to be accompanied by elevated expression of proto-oncogenes. Using gene-specific DNA probes, we examined the levels of the expression (transcription) of heat-shock protein genes and two nuclear proto-oncogenes, c-fos and c-myc, in the embryos removed from irradiated pregnant mother rats 4 or 5 days after the irradiation. We found that the levels of expression in vivo of the hsp70 and c-myc genes in the irradiated embryos increased by approximately twofold as compared with those in the control. The expression in vivo of the c-fos gene was not detected in either the irradiated or non-irradiated embryos. After 0.5-hr incubation in vitro of the embryos, however, the expression of the c-fos gene in the irradiated embryos was highly enhanced whereas the control showed no changes. Although the exact functions of these gene products still remain obscure, the enhanced expression of hsp70 gene(s) and the nuclear proto-oncogenes observed in the present study may reflect repair of intracellular damages and/or regeneration of tissue by compensatory cell proliferation, processes that may disturb the normal program of organogenesis

  2. Proto-oncogene FBI-1 (Pokemon/ZBTB7A) Represses Transcription of the Tumor Suppressor Rb Gene via Binding Competition with Sp1 and Recruitment of Co-repressors*S⃞

    Science.gov (United States)

    Jeon, Bu-Nam; Yoo, Jung-Yoon; Choi, Won-Il; Lee, Choong-Eun; Yoon, Ho-Geun; Hur, Man-Wook

    2008-01-01

    FBI-1 (also called Pokemon/ZBTB7A) is a BTB/POZ-domain Krüppel-like zinc-finger transcription factor. Recently, FBI-1 was characterized as a proto-oncogenic protein, which represses tumor suppressor ARF gene transcription. The expression of FBI-1 is increased in many cancer tissues. We found that FBI-1 potently represses transcription of the Rb gene, a tumor suppressor gene important in cell cycle arrest. FBI-1 binds to four GC-rich promoter elements (FREs) located at bp –308 to –188 of the Rb promoter region. The Rb promoter also contains two Sp1 binding sites: GC-box 1 (bp –65 to –56) and GC-box 2 (bp –18 to –9), the latter of which is also bound by FBI-1. We found that FRE3 (bp –244 to –236) is also a Sp1 binding element. FBI-1 represses transcription of the Rb gene not only by binding to the FREs, but also by competing with Sp1 at the GC-box 2 and the FRE3. By binding to the FREs and/or the GC-box, FBI-1 represses transcription of the Rb gene through its POZ-domain, which recruits a co-repressor-histone deacetylase complex and deacetylates histones H3 and H4 at the Rb gene promoter. FBI-1 inhibits C2C12 myoblast cell differentiation by repressing Rb gene expression. PMID:18801742

  3. Mutation analysis of the RET proto-oncogene in Dutch families with MEN 2A, MEN 2B and FMTC : Two novel mutations and one de novo mutation for MEN 2A

    NARCIS (Netherlands)

    Landsvater, RM; Jansen, RPM; Hofstra, RMW; Buys, CHCM; Lips, CJM; vanAmstel, HKP

    Hereditary C-cell carcinoma is encountered in multiple endocrine neoplasia type 2A (MEN 2A), MEN 2B, and familial medullary thyroid carcinoma (FMTC). Mutations of the RET proto-oncogene are associated with all three diseases. To obtain an insight into the molecular heterogeneity of MEN 2 syndromes

  4. Hypomethylation mediated by decreased DNMTs involves in the activation of proto-oncogene MPL in TK6 cells treated with hydroquinone.

    Science.gov (United States)

    Liu, Linhua; Ling, Xiaoxuan; Liang, Hairong; Gao, Yuting; Yang, Hui; Shao, Junli; Tang, Huanwen

    2012-03-25

    Hydroquinone (HQ), one of the most important metabolites derived from benzene, is known to be associated with acute myelogenous leukemia (AML) risk, however, its carcinogenic mechanism remains unclear. In this study, the epigenetic mechanism of HQ exposure was investigated. We characterized the epigenomic response of TK6 cells to HQ exposure, and examined the mRNA expression of DNA methyltransferases (DNMTs) including DNMT1, DNMT3a and DNMT3b, methyl-CpG-binding domain protein 2 (MBD2) and six proto-oncogenes (MPL, RAF1, MYB, MYC, ERBB2 and BRAF). Compared to the control cells, HQ exposure (2.5, 5.0, 10.0 and 20.0 μM for 48 h) resulted in the decrease of DNMTs and MBD2 expression, the global hypomethylation and increase of MPL at mRNA level. Meanwhile, most of these changes were in dose-dependent manner. Moreover, inhibition of DNMTs induced by 5-aza-2'-deoxycytidine (5-AZA), an identified DNMT inhibitor, caused more induction of MPL expression at mRNA level compared to the HQ (10.0 μM) pre-treated group. Furthermore, treatment of HQ potentially led to MPL itself hypomethylation (10.0 and 20.0 μM reduced by 47% and 44%, respectively), further revealing that the activation of proto-oncogene MPL was related to hypomethylation in its DNA sequences. In conclusion, hypomethylation, including global and specific hypomethylation, might be involved in the activation of MPL, and the hypomethylation could be induced by decreased DNMTs in TK6 cells exposed to HQ. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  5. Effects of 12-O-tetradecanoyl-phorbol-13-acetate [corrected] and sodium lauryl sulfate on the production and expression of cytokines and proto-oncogenes in photoaged and intrinsically aged human keratinocytes.

    Science.gov (United States)

    Suh, D H; Youn, J I; Eun, H C

    2001-11-01

    Skin aging may be divided into photoaging and intrinsic aging. The purpose of this study was to investigate the effects of 12-O-tetradecanoyl-phorbol-13-acetate and sodium lauryl sulfate on the production and expression of cytokines and proto-oncogenes in photoaged and intrinsically aged skin, compared with young skin. Keratinocytes were taken from newborns, young adults in their twenties, and from the forearm and thigh of volunteers in their fifties and seventies. Interleukin-1alpha and -6, and interleukin-1 receptor antagonist, c-fos and c-myc were measured after cultured keratinocytes had been treated with 12-O-tetradecanoyl-phorbol-13-acetate and sodium lauryl sulfate. There has been no report concerning the dependence of cytokine production by sodium lauryl sulfate upon photoaging and intrinsic aging. This study also involves the first investigation of the effects of aging on c-myc expression by 12-O-tetradecanoyl-phorbol-13-acetate treatment. Cytokine production decreased markedly with age. These results suggest the progressive decline of cellular function with age. The ratio of cytokine production in the irritant-treated group compared with that in the control group showed a different pattern in photoaging and intrinsic aging. With the significant difference between photoaging and intrinsic aging, T/C ratio decreased in interleukin-1alpha and interleukin-1 receptor antagonist upon aging, whereas it increased in interleukin-6. S/C ratio was uniquely elevated on photoaged skin in the 50 y age group. It is suggested that photoaged skin shows an exaggerated reaction to surfactant. Compared with the control, c-fos expression in 12-O-tetradecanoyl-phorbol-13-acetate-treated keratinocytes decreased with age in the thigh, but increased in the photoaged skin of forearm. The increased c-fos expression in 12-O-tetradecanoyl-phorbol-13-acetate-treated keratinocytes could be relevant for the predisposition of photoaged keratinocytes to malignant transformation.

  6. Eukaryotic translation initiator protein 1A isoform, CCS-3, enhances the transcriptional repression of p21CIP1 by proto-oncogene FBI-1 (Pokemon/ZBTB7A).

    Science.gov (United States)

    Choi, Won-Il; Kim, Youngsoo; Kim, Yuri; Yu, Mi-young; Park, Jungeun; Lee, Choong-Eun; Jeon, Bu-Nam; Koh, Dong-In; Hur, Man-Wook

    2009-01-01

    FBI-1, a member of the POK (POZ and Kruppel) family of transcription factors, plays a role in differentiation, oncogenesis, and adipogenesis. eEF1A is a eukaryotic translation elongation factor involved in several cellular processes including embryogenesis, oncogenic transformation, cell proliferation, and cytoskeletal organization. CCS-3, a potential cervical cancer suppressor, is an isoform of eEF1A. We found that eEF1A forms a complex with FBI-1 by co-immunoprecipitation, SDS-PAGE, and MALDI-TOF Mass analysis of the immunoprecipitate. GST fusion protein pull-downs showed that FBI-1 directly interacts with eEF1A and CCS-3 via the zinc finger and POZ-domain of FBI-1. FBI-1 co-localizes with either eEF1A or CCS-3 at the nuclear periplasm. CCS-3 enhances transcriptional repression of the p21CIP1 gene (hereafter referred to as p21) by FBI-1. The POZ-domain of FBI-1 interacts with the co-repressors, SMRT and BCoR. We found that CCS-3 also interacts with the co-repressors independently. The molecular interaction between the co-repressors and CCS-3 at the POZ-domain of FBI-1 appears to enhance FBI-1 mediated transcriptional repression. Our data suggest that CCS-3 may be important in cell differentiation, tumorigenesis, and oncogenesis by interacting with the proto-oncogene FBI-1 and transcriptional co-repressors. Copyright 2009 S. Karger AG, Basel.

  7. The proto-oncogenic protein TAL1 controls TGF-β1 signaling through interaction with SMAD3

    Directory of Open Access Journals (Sweden)

    Jean-Michel Terme

    2016-06-01

    Full Text Available TGF-β1 is involved in many aspects of tissue development and homeostasis including hematopoiesis. The TAL1 transcription factor is also an important player of this latter process and is expressed very early in the myeloid and erythroid lineages. We previously established a link between TGF-β1 signaling and TAL1 by showing that the cytokine was able to induce its proteolytic degradation by the ubiquitin proteasome pathway. In this manuscript we show that TAL1 interacts with SMAD3 that acts in the pathway downstream of TGF-β1 association with its receptor. TAL1 expression strengthens the positive or negative effect of SMAD3 on various genes. Both transcription factors activate the inhibitory SMAD7 factor through the E box motif present in its transcriptional promoter. DNA precipitation assays showed that TAL1 present in Jurkat or K562 cells binds to this SMAD binding element in a SMAD3 dependent manner. SMAD3 and TAL1 also inhibit several genes including ID1, hTERT and TGF-β1 itself. In this latter case TAL1 and SMAD3 can impair the positive effect exerted by E47. Our results indicate that TAL1 expression can modulate TGF-β1 signaling by interacting with SMAD3 and by increasing its transcriptional properties. They also suggest the existence of a negative feedback loop between TAL1 expression and TGF-β1 signaling.

  8. Characteristics of lentiviral vectors harboring the proximal promoter of the vav proto-oncogene: a weak and efficient promoter for gene therapy.

    Science.gov (United States)

    Almarza, Elena; Río, Paula; Meza, Nestor W; Aldea, Montserrat; Agirre, Xabier; Guenechea, Guillermo; Segovia, José C; Bueren, Juan A

    2007-08-01

    Recent published data have shown the efficacy of gene therapy treatments of certain monogenic diseases. Risks of insertional oncogenesis, however, indicate the necessity of developing new vectors with weaker or cell-restricted promoters to minimize the trans-activation activity of integrated proviruses. We have inserted the proximal promoter of the vav proto-oncogene into self-inactivating lentiviral vectors (vav-LVs) and investigated the expression pattern and therapeutic efficacy of these vectors. Compared with other LVs frequently used in gene therapy, vav-LVs mediated a weak, though homogeneous and stable, expression in in vitro-cultured cells. Transplantation experiments using transduced mouse bone marrow and human CD34(+) cells confirmed the stable activity of the promoter in vivo. To investigate whether the weak activity of this promoter was compatible with a therapeutic effect, a LV expressing the Fanconi anemia A (FANCA) gene was constructed (vav-FANCA LV). Although this vector induced a low expression of FANCA, compared to the expression induced by a LV harboring the spleen focus-forming virus (SFFV) promoter, the two vectors corrected the phenotype of cells from a patient with FA-A with the same efficacy. We propose that self-inactivating vectors harboring weak promoters, such as the vav promoter, will improve the safety of gene therapy and will be of particular interest for the treatment of diseases where a high expression of the transgene is not required.

  9. Amplification of the Ect2 proto-oncogene and over-expression of Ect2 mRNA and protein in nickel compound and methylcholanthrene-transformed 10T1/2 mouse fibroblast cell lines

    International Nuclear Information System (INIS)

    Clemens, Farrah; Verma, Rini; Ramnath, Jamuna; Landolph, Joseph R.

    2005-01-01

    Occupational exposure of humans to mixtures of insoluble and soluble nickel (Ni) compounds correlates with increased incidences of lung, sinus, and pharyngeal tumors. Specific insoluble Ni compounds are carcinogenic to animals by inhalation and induce morphological and neoplastic transformation of cultured rodent cells. Our objectives were to (1) understand mechanisms of nickel ion-induced cell transformation, hence carcinogenesis and (2) develop biomarkers of nickel ion exposure and nickel ion-induced cell transformation. We isolated mRNAs from green nickel oxide (NiO), crystalline nickel monosulfide (NiS), and 3-methylcholanthrene (MCA) transformed C3H/10T1/2 Cl 8 cell lines, and determined by mRNA differential display that nine mRNA fragments were differentially expressed between Ni transformed and non-transformed 10T1/2 cell lines. Fragment R2-5 was expressed at higher steady-state levels in the transformed cell lines. R2-5 had 100% sequence identity to part of the coding region of Ect2, a mouse proto-oncogene encoding a GDP-GTP exchange factor. The 3.9-kb Ect2 transcript was expressed at 1.6- to 3.6-fold higher steady-state levels in four Ni transformed, and in two MCA-transformed, cell lines. Ect2 protein was expressed at 3.0- to 4.5-fold higher steady-state levels in Ni-transformed and in MCA-transformed cell lines. The Ect2 gene was amplified by 3.5- to 10-fold in Ni transformed, and by 2.5- to 3-fold in MCA transformed cell lines. Binding of nickel ions to enzymes of DNA synthesis likely caused amplification of the Ect2 gene. Ect2 gene amplification and over-expression of Ect2 mRNA and protein can cause microtubule disassembly and cytokinesis, contributing to induction and maintenance of morphological, anchorage-independent, and neoplastic transformation of these cell lines. Over-expression of Ect2 protein is a useful biomarker to detect exposure to nickel compounds and nickel ion-induced morphological and neoplastic cell transformation

  10. In-vivo fluorescence detection of breast cancer growth factor receptors by fiber-optic probe

    Science.gov (United States)

    Bustamante, Gilbert; Wang, Bingzhi; DeLuna, Frank; Sun, LuZhe; Ye, Jing Yong

    2018-02-01

    Breast cancer treatment options often include medications that target the overexpression of growth factor receptors, such as the proto-oncogene human epidermal growth factor receptor 2 (HER2/neu) and epidermal growth factor receptor (EGFR) to suppress the abnormal growth of cancerous cells and induce cancer regression. Although effective, certain treatments are toxic to vital organs, and demand assurance that the pursued receptor is present at the tumor before administration of the drug. This requires diagnostic tools to provide tumor molecular signatures, as well as locational information. In this study, we utilized a fiber-optic probe to characterize in vivo HER2 and EGFR overexpressed tumors through the fluorescence of targeted dyes. HER2 and EGFR antibodies were conjugated with ICG-Sulfo-OSu and Alexa Fluor 680, respectively, to tag BT474 (HER2+) and MDA-MB-468 (EGFR+) tumors. The fiber was inserted into the samples via a 30-gauge needle. Different wavelengths of a supercontinuum laser were selected to couple into the fiber and excite the corresponding fluorophores in the samples. The fluorescence from the dyes was collected through the same fiber and quantified by a time-correlated single photon counter. Fluorescence at different antibody-dye concentrations was measured for calibration. Mice with subcutaneous HER2+ and/or EGFR+ tumors received intravenous injections of the conjugates and were later probed at the tumor sites. The measured fluorescence was used to distinguish between tumor types and to calculate the concentration of the antibody-dye conjugates, which were detectable at levels as low as 40 nM. The fiber-optic probe presents a minimally invasive instrument to characterize the molecular signatures of breast cancer in vivo.

  11. Cytogenetic evaluation of human glial tumors: correlation of overexpression of epidermal growth factor receptor (EGFB) with abnormalities of chromosome 7

    International Nuclear Information System (INIS)

    Bell, C.W.

    1987-01-01

    Chromosome banding analysis of human glial tumors were performed using G- and Q-banding techniques in an attempt to establish recurring sites of chromosome change. Results revealed a nonrandom karyotypic profile including aneuploidy and considerable variation in chromosome number (range 40 → 200). All tumors examined displayed numerical abnormalities, with the most common numeric change being a gain of chromosome 7. An attempt was then made to correlate the observed chromosome 7 changes with activation of the cellular proto-oncogene c-erb-B, whose produce is the epidermal growth factor receptor (EGFR). Six human glial tumors were analyzed for 125 I-EGF binding, EGFR gene copy number, EGFR gene rearrangement, mRNA expression, and karyotypic profile. Saturation analysis at 4 0 C revealed significant numbers of EGFR's in all 6 tumors. Southern blotting analysis utilizing cDNA probes for the EGFR failed to demonstrate significant amplification or structural rearrangement of the EFGR gene. The results suggest that overexpression of the EGFR may be related to an alternative mechanism, other than gene amplification and elevated mRNA levels, such as the regulation of receptor biosynthesis and degradation. In summary, findings indicate that alterations of chromosome 7 are the most prevalent chromosomal change in human glial tumors, and that these alterations may lead to overexpression of the protooncogene c-erb-B

  12. Biological aspects and tumorigenic activity of the Ras proto-oncogenic family Aspectos biológicos e atividade tumorigênica da família proto-oncogênica Ras

    Directory of Open Access Journals (Sweden)

    Juliano André Boquett

    2010-12-01

    Full Text Available Proto-oncogenes play an important role in the regulation of the cellular cycle, being critical to the tumorigenesis. In this category we can find the RAS family. Due to the high transformation potential of these genes, this family is the best described and most studied one. It is formed by the H-, K- and the N-RAS genes, that codify highly related proteins expressed in several types of cells, denominated p21.These proteins act in the sign transduction from the membrane to the nucleus, as well as in the control of proliferation, differentiation and cellular death, and they are regulated by the interaction with GDP (inactive and GTP (active. These proteins show variation in only 10 - 15% of the primary structure, in the C-terminal portion denominated hyper-variant region. When in the oncogenic form, the p21 proteins remain active, providing continuous stimuli to the cellular proliferation. Among the RAS genes, K-RAS ones have been the most studied for presenting more frequent mutations and for being present in more aggressive tumors, implying the patients’ shorter survival time. Due to these facts and relative bibliography lack in the Portuguese language on this family, we presented in this work a systematized and updated review on the RAS genes. Os proto-oncogenes desempenham importante papel na regulação do ciclo celular, e são críticos à tumorigênese. Nessa categoria se encontra a família RAS, que, devido ao elevado potencial transformante dos genes que a compõem, é uma das mais bem descritas e estudadas. É formada pelos genes H-, K- e N-RAS, que codificam proteínas altamente relacionadas expressas em vários tipos de células, denominadas p21. Estas atuam na transdução de sinal da membrana ao núcleo, estão envolvidas no controle da proliferação, diferenciação e morte celular e são reguladas pela interação com GDP (inativa e GTP (ativa. As proteínas p21 diferem em apenas 10-15% da sua estrutura primária, na porção C

  13. UniProt search blastx result: AK288287 [KOME

    Lifescience Database Archive (English)

    Full Text Available C 2.7.10.1) (HGF receptor) (Scatter factor receptor) (SF receptor) (HGF/SF receptor) (Met proto-oncogene tyrosine kinase) (c-Met) - Neofelis nebulosa (Clouded leopard) 3.00E-18 ...

  14. UniProt search blastx result: AK289170 [KOME

    Lifescience Database Archive (English)

    Full Text Available C 2.7.10.1) (HGF receptor) (Scatter factor receptor) (SF receptor) (HGF/SF receptor) (Met proto-oncogene tyrosine kinase) (c-Met) - Neofelis nebulosa (Clouded leopard) 1.00E-18 ...

  15. UniProt search blastx result: AK287484 [KOME

    Lifescience Database Archive (English)

    Full Text Available C 2.7.10.1) (HGF receptor) (Scatter factor receptor) (SF receptor) (HGF/SF receptor) (Met proto-oncogene tyrosine kinase) (c-Met) - Neofelis nebulosa (Clouded leopard) 3.00E-16 ...

  16. UniProt search blastx result: AK288291 [KOME

    Lifescience Database Archive (English)

    Full Text Available C 2.7.10.1) (HGF receptor) (Scatter factor receptor) (SF receptor) (HGF/SF receptor) (Met proto-oncogene tyrosine kinase) (c-Met) - Neofelis nebulosa (Clouded leopard) 6.00E-14 ...

  17. UniProt search blastx result: AK288206 [KOME

    Lifescience Database Archive (English)

    Full Text Available C 2.7.10.1) (HGF receptor) (Scatter factor receptor) (SF receptor) (HGF/SF receptor) (Met proto-oncogene tyrosine kinase) (c-Met) - Neofelis nebulosa (Clouded leopard) 4.00E-21 ...

  18. UniProt search blastx result: AK287970 [KOME

    Lifescience Database Archive (English)

    Full Text Available C 2.7.10.1) (HGF receptor) (Scatter factor receptor) (SF receptor) (HGF/SF receptor) (Met proto-oncogene tyrosine kinase) (c-Met) - Neofelis nebulosa (Clouded leopard) 3.00E-20 ...

  19. Cytotoxic activity of Justicia spicigera is inhibited by bcl-2 proto-oncogene and induces apoptosis in a cell cycle dependent fashion.

    Science.gov (United States)

    Cáceres-Cortés, J R; Cantú-Garza, F A; Mendoza-Mata, M T; Chavez-González, M A; Ramos-Mandujano, G; Zambrano-Ramírez, I R

    2001-12-01

    Identification of organic compounds from plants is of clinical significance because of the effect that they might have in patients with haematopoietic disorders. We studied the effect of the plant extract Justicia spicigera (Acanthaceae) in different haematopoietic cells: human leukaemic cell lines, umbilical cord blood cells, and mouse bone marrow cells. By examining colony formation and performing the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) assay it was shown that the plant extract of Justicia spicigera contains cytotoxic factors for leukaemic cells and has no proliferative activity on normal haematopoietic progenitor cells. Our results show that this plant extract induces apoptosis in the human leukaemia cell line TF-1, but not in the bcl-2 transfectant cell line TB-1. Similar results were obtained using a haemopoietic cell line 32D and 32DBcl2. The cultures of umbilical cord blood cells and mouse bone marrow that contain granulocyte-macrophage colony-stimulating factor (GM-CSF) do not proliferate or become terminally differentiated in the presence of the infusion of Justicia spicigera. GM-CSF that acts by abrogating programmed cell death is not sufficient to inhibit the apoptotic stimulus in TF-1 and 32D cells. Moreover mouse fibroblasts (3T3) and two cervical carcinoma cell lines CALO and INBL, undergo apoptosis in the presence of different concentrations of an infusion from the plant. Our data show that there is a strong correlation between the cytotoxic effect and cell proliferation. Together, these results indicate that the plant infusion of Justicia spicigera does not contain any haematopoietic activity, induces apoptosis inhibited by bcl-2 and is linked to cell proliferation. Copyright 2001 John Wiley & Sons, Ltd.

  20. Targeting Self-Binding Peptides as a Novel Strategy To Regulate Protein Activity and Function: A Case Study on the Proto-oncogene Tyrosine Protein Kinase c-Src.

    Science.gov (United States)

    Bai, Zhengya; Hou, Shasha; Zhang, Shilei; Li, Zhongyan; Zhou, Peng

    2017-04-24

    Previously, we have reported a new biomolecular phenomenon spanning between protein folding and binding, termed as self-binding peptides (SBPs), where a short peptide segment in monomeric protein functions as a molecular switch by dynamically binding to/unbinding from its cognate domain in the monomer (Yang et al. J. Chem. Inf. 2015, 55, 329-342). Here, we attempt to raise the SBP as a new class of druggable targets to regulate the biological activity and function of proteins. A case study was performed on the proto-oncogene nonreceptor tyrosine kinase, c-Src, which contains two SBPs that bind separately to SH3 and SH2 domains of the kinase. State-of-the-art molecular dynamics (MD) simulations and post binding energetics analysis revealed that disrupting the kinase-intramolecular interactions of SH3 and SH2 domains with their cognate SBP ligands can result in totally different effects on the structural dynamics of c-Src kinase architecture; targeting the SH2 domain unlocks the autoinhibitory form of the kinase-this is very similar to the pTyr527 dephosphorylation that functionally activates the kinase, whereas targeting the SH3 domain can only release the domain from the tightly packed kinase but has a moderate effect on the kinase activity. Subsequently, based on the cognate SBP sequence we computationally designed a number of SH2-binding phosphopeptides using a motif grafting strategy. Fluorescence polarization (FP) assay observed that most of the designed phosphopeptides have higher binding affinity to SH2 domain as compared to the native SBP segment (K d = 53 nM). Kinase assay identified a typical dose-response relationship of phosphopeptides against kinase activation, substantiating that disruption of SH2-SBP interaction can mimic c-Src dephosphorylation and activate the kinase. Two rationally designed phosphopeptides, namely EPQpYEEIEN and EPQpYEELEN, were determined as strong binders of SH2 domain (K d = 8.3 and 15 nM, respectively) and potent activators of

  1. Detección de una mutación no estándar en el Proto-oncogen RET por mutagénesis dirigida Detection of a non-standard mutation in the ret protoncogene by site directed mutagenesis

    Directory of Open Access Journals (Sweden)

    Sebastián Real

    2005-03-01

    Full Text Available El síndrome de MEN2A es una enfermedad autosómica dominante que se caracteriza por el desarrollo de cáncer medular de tiroides, feocromocitoma e hiperplasia de paratiroides. Mutaciones en el ret proto-oncogén se asocian con MEN2A, con una penetrancia cercana al 100%. El gen se encuentra en el cromosoma 10q11.2 y codifica para una proteína transmembrana con función de receptor del tipo tirosina quinasa. Mutaciones que afectan el dominio extracelular de la proteína estimulan la dimerización espontánea del receptor y un aumento de la actividad de tirosina quinasa basal. El codón 634 codifica para una cisteína, y es considerado un sitio hot-spot por encontrarse mutado en el 85% de las familias con MEN2A. Para este sitio, nuestro grupo desarrolló en 2002 una metodología de detección indirecta y económica. Ante una familia sospechada de MEN2A, se aplicó esta estrategia, que reveló un codón 634 sano. Por posterior secuenciación se confirmó que el paciente índice portaba una mutación en el codón 611. Se desarrolló una nueva estrategia familia-específica por PCR mutagénica, que permitió diagnosticar en nuestro país a todos los integrantes de la familia con costos accesibles. Un niño en el cual se halló la mutación, fue tiroidectomizado preventivamente, y a la fecha goza de buena salud. De esta manera, combinando la estrategia de detección de mutaciones en el sitio hot-spot y un posterior diseño de otra metodología familia-específica se pudo diagnosticar e intervenir preventivamente a la familia, sin enviar todas las muestras al extranjero.MEN2A is an autosomic dominant disease, characterized by medullary thyroid cancer, pheochromocytoma and parathyroid hyperplasia. Mutations in the ret proto-oncogene are associated with this disease, with almost 100% of pennetrance. The gene, situated on chromosome 10q11.2, codes for a transmembrane protein with a tirosinkinase-like receptor function. Mutations that affect its

  2. Increased Level of Phosphorylated ShcA Measured by Chemiluminescence-Linked Immunoassay Is a Predictor of Good Prognosis in Primary Breast Cancer Expressing Low Levels of Estrogen Receptor

    Directory of Open Access Journals (Sweden)

    Serenella Eppenberger-Castori

    2010-03-01

    Full Text Available The SH2 domain-containing adaptor protein ShcA is a proto-oncogene involved in growth factor receptor signaling. The role of phosphorylated ShcA is to link receptor tyrosine kinases with the SH2-containing adaptor protein Grb2, thus facilitating signal transduction from receptor tyrosine kinases to Ras, leading to MAPK activation. The present study was designed to investigate the prognostic significance of phosphorylated ShcA in primary breast cancer and its association in the interactions between the ER and ErbB2 pathways. Using a two-site chemiluminescence-linked immunosorbent assay, we detected the quantitative expression levels of total tyrosine- and threonine-phosphorylated ShcA in cytosol fractions obtained from fresh frozen tissue samples of 153 selected primary breast cancer patients. ShcA phosphorylation was not associated with nodal status, estrogen receptor (ER status or grading. High levels of both tyrosine (pYShcA and serine (pSShcA phosphorylated ShcA correlated with good prognosis (p < 0.01, with respect to both disease-free (DFS and overall survival (OS. In addition, pShcA levels were found to correlate with threonine-phosphorylated ErbB2 and inversely with phosphorylated Akt (pAkt, as well as ErbB2 and ER expression levels. Our findings demonstrate that ShcA activation in primary breast cancer patients correlates with low levels of ER, and is associated with good prognosis.

  3. Increased Level of Phosphorylated ShcA Measured by Chemiluminescence-Linked Immunoassay Is a Predictor of Good Prognosis in Primary Breast Cancer Expressing Low Levels of Estrogen Receptor

    International Nuclear Information System (INIS)

    Cicenas, Jonas; Küng, Willy; Eppenberger, Urs; Eppenberger-Castori, Serenella

    2010-01-01

    The SH2 domain-containing adaptor protein ShcA is a proto-oncogene involved in growth factor receptor signaling. The role of phosphorylated ShcA is to link receptor tyrosine kinases with the SH2-containing adaptor protein Grb2, thus facilitating signal transduction from receptor tyrosine kinases to Ras, leading to MAPK activation. The present study was designed to investigate the prognostic significance of phosphorylated ShcA in primary breast cancer and its association in the interactions between the ER and ErbB2 pathways. Using a two-site chemiluminescence-linked immunosorbent assay, we detected the quantitative expression levels of total tyrosine- and threonine-phosphorylated ShcA in cytosol fractions obtained from fresh frozen tissue samples of 153 selected primary breast cancer patients. ShcA phosphorylation was not associated with nodal status, estrogen receptor (ER) status or grading. High levels of both tyrosine (pYShcA) and serine (pSShcA) phosphorylated ShcA correlated with good prognosis (p < 0.01), with respect to both disease-free (DFS) and overall survival (OS). In addition, pShcA levels were found to correlate with threonine-phosphorylated ErbB2 and inversely with phosphorylated Akt (pAkt), as well as ErbB2 and ER expression levels. Our findings demonstrate that ShcA activation in primary breast cancer patients correlates with low levels of ER, and is associated with good prognosis

  4. Fibroblast growth factor receptors in breast cancer.

    Science.gov (United States)

    Wang, Shuwei; Ding, Zhongyang

    2017-05-01

    Fibroblast growth factor receptors are growth factor receptor tyrosine kinases, exerting their roles in embryogenesis, tissue homeostasis, and development of breast cancer. Recent genetic studies have identified some subtypes of fibroblast growth factor receptors as strong genetic loci associated with breast cancer. In this article, we review the recent epidemiological findings and experiment results of fibroblast growth factor receptors in breast cancer. First, we summarized the structure and physiological function of fibroblast growth factor receptors in humans. Then, we discussed the common genetic variations in fibroblast growth factor receptors that affect breast cancer risk. In addition, we also introduced the potential roles of each fibroblast growth factor receptors isoform in breast cancer. Finally, we explored the potential therapeutics targeting fibroblast growth factor receptors for breast cancer. Based on the biological mechanisms of fibroblast growth factor receptors leading to the pathogenesis in breast cancer, targeting fibroblast growth factor receptors may provide new opportunities for breast cancer therapeutic strategies.

  5. Expression of Truncated Neurokinin-1 Receptor in Childhood Neuroblastoma is Independent of Tumor Biology and Stage.

    Science.gov (United States)

    Pohl, Alexandra; Kappler, Roland; Mühling, Jakob; VON Schweinitz, Dietrich; Berger, Michael

    2017-11-01

    Neuroblastoma is an embryonal malignancy arising from the aberrant growth of neural crest progenitor cells of the sympathetic nervous system. The tachykinin receptor 1 (TACR1) - substance P complex is associated with tumoral angiogenesis and cell proliferation in a variety of cancer types. Inhibition of TACR1 was recently described to impede growth of NB cell lines. However, the relevance of TACR1 in clinical settings is unknown. We investigated gene expression levels of full-length and truncated TACR1 in 59 neuroblastomas and correlated these data with the patients' clinical parameters such as outcome, metastasis, International Neuroblastoma Staging System (INSS) status, MYCN proto-oncogene, bHLH transcription factor (MYCN) status, gender and age. Our results indicated that TACR1 is ubiquitously expressed in neuroblastoma but expression levels are independent of clinical parameters. Our data suggest that TACR1 might serve as a potent anticancer target in a large variety of patients with neuroblastoma, independent of tumor biology and clinical stage. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

  6. Interleukin-1/toll-like receptor-induced nuclear factor kappa B signaling participates in intima hyperplasia after carotid artery balloon injury in goto-kakizaki rats: a potential target therapy pathway.

    Directory of Open Access Journals (Sweden)

    Xiaotian Zhang

    Full Text Available The value of restenosis after percutaneous coronary intervention (PCI is recognized worldwide, especially for diabetic patients. Interleukin-1/Toll-like receptor (IL-1/TLR signaling is involved in innate and adaptive immune responses, but whether and how the IL-1/TLR-induced nuclear factor kappa B (NFκB pathway plays key roles in intimal formation is unclear. The underlying mechanism of intima hyperplasia was investigated with a model of carotid balloon injury in Goto-Kakizaki (GK and Wistar rats and with lipopolysaccharide-stimulated macrophages. Elastic-van Gieson staining showed the medial area peakedon Day 3 post-injury and decreased by Day 7 post-injury in both GK and Wistar rats. The N/M at Day 7 in GK rats was significantly higher than in Wistar rats (p<0.001. The percent of 5-ethynyl-2'-deoxyuridine (EdU staining-positive cells on Day 3 post-injury was greater than seen on Day 7 post-injury in GK and Wistar rats. The percent of EdU-positive cells on Days 3 and 7 post-injury in Wistar rats was less than that found in GK rats (p<0.01; p<0.05. NFκBp65 immunostaining had increased by Day 7 post-injury. Agilent Whole Genome Oligo Microarray verified that the IL-1/TLR-induced NFκB pathway was activated by carotid balloon injury. TLR4, IL-1 receptor associated kinase, inhibitors α of NFκB, human antigen R, c-Myc (Proto-Oncogene Proteins, EGF-like module-containing mucin-like hormone receptor-like 1 and Interleukin-6 were up-regulated or down-regulated according to immunochemistry, quantitative real-time PCR, Western blotting and Enzyme linked immunosorbent assay. Overall, we conclude that the IL-1/TLR-induced NFκB pathway participates in the intimal hyperplasia after carotid injury in GK and Wistar rats and that GK rats respond more intensely to the inflammation than Wistar rats.

  7. Suppression of bcr-abl synthesis by siRNAs or tyrosine kinase activity by Glivec alters different oncogenes, apoptotic/antiapoptotic genes and cell proliferation factors (microarray study).

    Science.gov (United States)

    Zhelev, Zhivko; Bakalova, Rumiana; Ohba, Hideki; Ewis, Ashraf; Ishikawa, Mitsuru; Shinohara, Yasuo; Baba, Yoshinobu

    2004-07-16

    Short 21-mer double-stranded/small-interfering RNAs (ds/siRNAs) were designed to target bcr-abl mRNA in chronic myelogenous leukemia. The ds/siRNAs were transfected into bcr-abl-positive K-562 (derived from blast crisis chronic myelogenous leukemia), using lipofectamine. Penetrating of ds/siRNAs into the cells was detected by fluorescent confocal microscopy, using fluorescein-labeled ds/siRNAs. The cells were treated with mix of three siRNA sequences (3 x 60 nM) during 6 days with three repetitive transfections. The siRNA-treatment was accompanied with significant reduction of bcr-abl mRNA, p210, protein tyrosine kinase activity and cell proliferation index. Treatment of cells with Glivec (during 8 days with four repetitive doses, 180 nM single dose) resulted in analogous reduction of cell proliferation activity, stronger suppression of protein tyrosine kinase activity, and very low reduction of p210. siRNA-mix and Glivec did not affect significantly the viability of normal lymphocytes. Microarray analysis of siRNA- and Glivec-treated K-562 cells demonstrated that both pathways of bcr-abl suppression were accompanied with overexpression and suppression of many different oncogenes, apoptotic/antiapoptotic and cell proliferation factors. The following genes of interest were found to decrease in relatively equal degree in both siRNA- and Glivec-treated cells: Bcd orf1 and orf2 proto-oncogene, chromatin-specific transcription elongation factor FACT 140-kDa subunit mRNA, gene encoding splicing factor SF1, and mRNA for Tec protein tyrosine kinase. siRNA-mix and Glivec provoked overexpression of the following common genes: c-jun proto-oncogene, protein kinase C-alpha, pvt-1 oncogene homologue (myc activator), interleukin-6, 1-8D gene from interferon-inducible gene family, tumor necrosis factor receptor superfamily (10b), and STAT-induced STAT inhibitor.

  8. The proto-oncogene product p120CBL and the adaptor proteins CRKL and c-CRK link c-ABL, p190BCR/ABL and p210BCR/ABL to the phosphatidylinositol-3' kinase pathway.

    Science.gov (United States)

    Sattler, M; Salgia, R; Okuda, K; Uemura, N; Durstin, M A; Pisick, E; Xu, G; Li, J L; Prasad, K V; Griffin, J D

    1996-02-15

    Chronic myelogenous leukemia (CML) and some acute lymphoblastic leukemias (ALL) are caused by the t(9;22) chromosome translocation, which produces the constitutively activated BCR/ABL tyrosine kinase. When introduced into factor dependent hematopoietic cell lines, BCR/ABL induces the tyrosine phosphorylation of many cellular proteins. One prominent BCR/ABL substrate is p120CBL, the cellular homolog of the v-Cbl oncoprotein. In an effort to understand the possible contribution of p120CBL to transformation by BCR/ABL, we looked for cellular proteins which associate with p120CBL in hematopoietic cell lines transformed by BCR/ABL. In addition to p210BCR/ABL and c-ABL, p120CBL coprecipitated with an 85 kDa phosphoprotein, which was identified as the p85 subunit of PI3K. Anti-p120CBL immunoprecipitates from BCR/ABL-transformed, but not from untransformed, cell lines contained PI3K lipid kinase activity. Interestingly, the adaptor proteins CRKL and c-CRK were also found in these complexes. In vitro binding studies indicated that the SH2 domains of CRKL and c-CRK bound directly to p120CBL, while the SH3 domains of c-CRK and CRKL bound to BCR/ABL and c-ABL. The N-terminal and the C-terminal SH2 and the SH3 domain of p85PI3K bound directly in vitro to p120CBL. The ABL-SH2, but not ABL-SH3, could also bind to p120CBL. These data suggest that BCR/ABL may induce the formation of multimeric complexes of signaling proteins which include p120CBL, PI3K, c-CRK or CRKL, c-ABL and BCR/ABL itself.

  9. Utilization of circular dichroism and electrospray ionization mass spectrometry to understand the formation and conversion of G-quadruplex DNA at the human c-myb proto-oncogene.

    Science.gov (United States)

    Fu, Hengqing; Yang, Pengfei; Hai, Jinhui; Li, Huihui

    2018-10-05

    G-quadruplex DNAs are involved in a number of key biological processes, including gene expression, transcription, and apoptosis. The c-myb oncogene contains a number of GGA repeats in its promoter which forms G-quadruplex, thus it could be used as a target in cancer therapeutics. Several in-vitro studies have used Circular Dichroism (CD) spectroscopy or electrospray ionization mass spectrometry (ESI-MS) to demonstrate formation and stability of G-quadruplex DNA structure in the promoter region of human c-myb oncogene. The factors affecting the c-myb G-quadruplex structures were investigated, such as cations (i.e. K + , NH 4 + and Na + ) and co-solutes (methanol and polyethylene glycol). The results indicated that the presence of cations and co-solutes could change the G-quadruplex structural population and promote its thermodynamic stabilization as indicated by CD melting curves. It indicated that the co-solutes preferentially stabilize the c-myb G-quadruplex structure containing both homo- and hetero-stacking. In addition, protopine was demonstrated as a binder of c-myb G-quadruplex as screened from a library of natural alkaloids using ESI-MS method. CD spectra showed that it could selectively stabilize the c-myb G-quadruplex structure compared to other six G-quadruplexes from tumor-related G-rich sequences and the duplex DNAs (both long and short-chain ones). The binding of protopine could induce the change in the G-quadruplex structural populations. Therefore, protopine with its high binding specificity could be considered as a precursor for the design of drugs to target and regulate c-myb oncogene transcription. Copyright © 2018 Elsevier B.V. All rights reserved.

  10. Characteristics of the mouse genomic histamine H1 receptor gene

    Energy Technology Data Exchange (ETDEWEB)

    Inoue, Isao; Taniuchi, Ichiro; Kitamura, Daisuke [Kyushu Univ., Fukuoka (Japan)] [and others

    1996-08-15

    We report here the molecular cloning of a mouse histamine H1 receptor gene. The protein deduced from the nucleotide sequence is composed of 488 amino acid residues with characteristic properties of GTP binding protein-coupled receptors. Our results suggest that the mouse histamine H1 receptor gene is a single locus, and no related sequences were detected. Interspecific backcross analysis indicated that the mouse histamine H1 receptor gene (Hrh1) is located in the central region of mouse Chromosome 6 linked to microphthalmia (Mitfmi), ras-related fibrosarcoma oncogene 1 (Raf1), and ret proto-oncogene (Ret) in a region of homology with human chromosome 3p. 12 refs., 3 figs.

  11. The potential roles of hepatocyte growth factor (HGF-MET pathway inhibitors in cancer treatment

    Directory of Open Access Journals (Sweden)

    Parikh RA

    2014-06-01

    Full Text Available Rahul A Parikh,1 Peng Wang,2 Jan H Beumer,3 Edward Chu,1 Leonard J Appleman11Division of Hematology-Oncology, University of Pittsburgh School of Medicine, Cancer Therapeutics Program, University of Pittsburgh Cancer Institute, Pittsburgh, PA, USA; 2Division of Medical Oncology, University of Kentucky College of Medicine, Markey Cancer Center, Lexington, KY, USA; 3University of Pittsburgh School of Pharmacy, Cancer Therapeutics Program, University of Pittsburgh Cancer Institute, Pittsburgh, PA, USAAbstract: MET is located on chromosome 7q31 and is a proto-oncogene that encodes for hepatocyte growth factor (HGF receptor, a member of the receptor tyrosine kinase (RTK family. HGF, also known as scatter factor (SF, is the only known ligand for MET. MET is a master regulator of cell growth and division (mitogenesis, mobility (motogenesis, and differentiation (morphogenesis; it plays an important role in normal development and tissue regeneration. The HGF-MET axis is frequently dysregulated in cancer by MET gene amplification, translocation, and mutation, or by MET or HGF protein overexpression. MET dysregulation is associated with an increased propensity for metastatic disease and poor overall prognosis across multiple tumor types. Targeting the dysregulated HGF-MET pathway is an area of active research; a number of monoclonal antibodies to HGF and MET, as well as small molecule inhibitors of MET, are under development. This review summarizes the key biological features of the HGF-MET axis, its dysregulation in cancer, and the therapeutic agents targeting the HGF-MET axis, which are in development.Keywords: MET inhibitor, HGF inhibitor, cancer

  12. Growth hormone-releasing factor induces c-fos expression in cultured primary pituitary cells

    DEFF Research Database (Denmark)

    Billestrup, Nils; Mitchell, R L; Vale, W

    1987-01-01

    GH-releasing factor (GRF) and somatostatin regulates the secretion and biosynthesis of GH as well as the proliferation of GH-producing cells. In order to further characterize the mitogenic effect of GRF, we studied the expression of the proto-oncogene c-fos in primary pituitary cells. Maximal...... induction of c-fos mRNA was observed 20-60 min after stimulation with 5 nM GRF, returning to basal levels after 2 h. Somatostatin-14 (5 nM) partially inhibited the GRF induced c-fos expression. Forskolin and phorbol 12, 13 dibutyrate induced c-fos gene in cultured primary pituitary cells with similar...

  13. Predictive value of EGFR overexpression and gene amplification on icotinib efficacy in patients with advanced esophageal squamous cell carcinoma.

    NARCIS (Netherlands)

    Wang, X.; Niu, H.; Fan, Q.; Lu, P.; Ma, C.; Liu, W.; Liu, Y.; Li, W.; Hu, S.; Ling, Y.; Guo, L.; Ying, J.; Huang, J.

    2016-01-01

    This study aimed to search for a molecular marker for targeted epithelial growth factor receptor (EGFR) inhibitor Icotinib by analyzing protein expression and amplification of EGFR proto-oncogene in esophageal squamous cell carcinoma (ESCC) patients.Immunohistochemistry and fluorescence in situ

  14. Pattern of hormone receptors and human epidermal growth factor ...

    African Journals Online (AJOL)

    Introduction: Breast cancer is the most common cancer among women globally. With immunohistochemistry (IHC), breast cancer is classified into four groups based on IHC profile of estrogen receptor (ER)/progesterone receptor (PR) and human epidermal growth factor receptor 2 (HER2/neu) expression, positive (+) and/or ...

  15. Molecular analysis of the nerve growth factor receptor

    International Nuclear Information System (INIS)

    Hempstead, B.; Patil, N.; Olson, K.; Chao, M.

    1988-01-01

    An essential molecule in the translocation of information by nerve growth factor (NGF) to responsive cells is the cell-surface receptor for NGF. This paper presents information on the genomic structure of the NGF receptor gene, NGF receptor models, and transfection of NGF receptors. Equilibrium binding of [ 125 I]NGF to cells reveals two distinct affinity states for the NGF receptor. The human NGF receptor gene is a single-copy gene, consisting of six exons that span 23 kb. The receptor gene is capable of being transferred to fibroblast cells from human genomic DNA and expressed at high levels. The constitutive nature of the receptor promoter sequence is a partial explanation of why this tissue-specific gene is expressed efficiently in a variety of nonneuronal cells after genomic gene transfer. The two kinetic forms of the NGF receptor appear to be encoded by the same protein, which is the product of a single gene

  16. Interaction of epidermal growth factor receptors with the cytoskeleton is related to receptor clustering

    NARCIS (Netherlands)

    van Belzen, N.; Spaargaren, M.; Verkleij, A. J.; Boonstra, J.

    1990-01-01

    Recently it has been established that cytoskeleton-associated epidermal growth factor (EGF) receptors are predominantly of the high-affinity class and that EGF induces a recruitment of low-affinity receptors to the cytoskeleton. The nature of this EGF-induced receptor-cytoskeleton interaction,

  17. Urokinase-type plasminogen activator receptor (uPAR), tissue factor (TF) and epidermal growth factor receptor (EGFR)

    DEFF Research Database (Denmark)

    Christensen, Anders; Kiss, Katalin; Lelkaitis, Giedrius

    2017-01-01

    Background: Tumor-specific biomarkers are a prerequisite for the development of targeted imaging and therapy in oral squamous cell carcinoma (OSCC). urokinase-type Plasminogen Activator Receptor (uPAR), Tissue Factor (TF) and Epidermal Growth Factor Receptor (EGFR) are three biomarkers that exhib...... with a reduced survival. uPAR seems to be a prognostic biomarker in oral cancer....

  18. Radiotherapy and receptor of epidermal growth factor

    International Nuclear Information System (INIS)

    Deberne, M.

    2009-01-01

    The expression level of the receptor of the epidermal growth factor is in correlation with the tumor cells radiosensitivity. An overexpression of the E.G.F.R. is often present in the bronchi cancer, epidermoid carcinomas of the O.R.L. sphere, esophagus, uterine cervix, and anal duct but also in the rectum cancers and glioblastomas. At the clinical level, the E.G.F.R. expression is in correlation with an unfavourable prognosis after radiotherapy in numerous tumoral localizations. In the rectum cancers it is an independent prognosis factor found in multifactorial analysis: increase of the rate of nodes and local recurrence when the E.G.F.R. is over expressed. In the uterine cervix cancers, the survival is is negatively affected in multifactorial analysis by the E.G.F.R. membranes expression level. At the therapy level, the development of anti E.G.F.R. targeted therapies (tyrosine kinase inhibitors and monoclonal antibodies) opens a new therapy field at radio-sensitivity potentiality. The irradiation makes an activation of the E.G.F.R. way that would be partially responsible of the post irradiation tumoral repopulation. This activation leads the phosphorylation of the PI3 kinase ways and M.A.P. kinase ones, then the Akt protein one that acts an apoptotic modulator part. It has been shown that blocking the E.G.F.R. way acts on three levels: accumulation of ells in phase G1, reduction of the cell repair and increasing of apoptosis. he inhibition of post irradiation action of the E.G.F.R. signal way is a factor explaining the ionizing radiation - anti E.G.F.R. synergy. The preclinical data suggest that the E.G.F.R. blocking by the monoclonal antibodies is more important than the use of tyrosine kinase inhibitors. A first positive randomized study with the cetuximab, published in 2006 in the epidermoid carcinomas of the O.R.L. sphere lead to its authorization on the market with the radiotherapy for this localization. The use of cetuximab in other indication with or in

  19. Steroid hormone and epidermal growth factor receptors in meningiomas.

    Science.gov (United States)

    Horsfall, D J; Goldsmith, K G; Ricciardelli, C; Skinner, J M; Tilley, W D; Marshall, V R

    1989-11-01

    A prospective study of steroid hormone and epidermal growth factor receptor expression in 57 meningiomas is presented. Scatchard analysis of radioligand binding identified 20% of meningiomas as expressing classical oestrogen receptors (ER) at levels below that normally accepted for positivity, the remainder being negative. ER could not be visualized in any meningioma using immunocytochemistry. Alternatively, 74% of meningiomas demonstrated the presence of progesterone receptors (PR) by Scatchard analysis, the specificity of which could not be attributed to glucocorticoid or androgen receptors. Confirmation of classical PR presence was determined by immunocytochemical staining. The presence of epidermal growth factor receptor (EGFR) was demonstrated in 100% of meningiomas using immunocytochemical staining. These data are reviewed in the context of previously reported results and are discussed in relation to the potential for medical therapy as an adjunct to surgery.

  20. Andrographolide regulates epidermal growth factor receptor and transferrin receptor trafficking in epidermoid carcinoma (A-431) cells

    Science.gov (United States)

    Tan, Y; Chiow, KH; Huang, D; Wong, SH

    2010-01-01

    Background and purpose: Andrographolide is the active component of Andrographis paniculata, a plant used in both Indian and Chinese traditional medicine, and it has been demonstrated to induce apoptosis in different cancer cell lines. However, not much is known about how it may affect the key receptors implicated in cancer. Knowledge of how andrographolide affects receptor trafficking will allow us to better understand new mechanisms by which andrographolide may cause death in cancer cells. Experimental approach: We utilized the well-characterized epidermal growth factor receptor (EGFR) and transferrin receptor (TfR) expressed in epidermoid carcinoma (A-431) cells as a model to study the effect of andrographolide on receptor trafficking. Receptor distribution, the total number of receptors and surface receptors were analysed by immunofluorescence, Western blot as well as flow-cytometry respectively. Key results: Andrographolide treatment inhibited cell growth, down-regulated EGFRs on the cell surface and affected the degradation of EGFRs and TfRs. The EGFR was internalized into the cell at an increased rate, and accumulated in a compartment that co-localizes with the lysosomal-associated membrane protein in the late endosomes. Conclusion and implications: This study sheds light on how andrographolide may affect receptor trafficking by inhibiting receptor movement from the late endosomes to lysosomes. The down-regulation of EGFR from the cell surface also indicates a new mechanism by which andrographolide may induce cancer cell death. PMID:20233216

  1. Signal transduction by the platelet-derived growth factor receptor

    International Nuclear Information System (INIS)

    Williams, L.T.; Escobedo, J.A.; Keating, M.T.; Coughlin, S.R.

    1988-01-01

    The mitogenic effects of platelet-derived growth factor (PDGF) are mediated by the PDGF receptor. The mouse PDGF receptor was recently purified on the basis of its ability to become tyrosine phosphorylated in response to the A-B human platelet form of PDGF, and the receptor amino acid sequence was determined from a full-length cDNA clone. Both the human and mouse receptor cDNA sequences have been expressed in Chinese hamster ovary fibroblast (CHO) cells that normally lack PDGF receptors. This paper summarizes recent results using this system to study signal transduction by the PDGF receptor. Some of the findings show that the KI domain of the PDGF receptor plays an important role in the stimulation of DNA synthesis by PDGF. Surprisingly, the kinase insert region is not essential for PDGF stimulation of PtdIns turnover, pH change, increase in cellular calcium, and receptor autophosphorylation. In addition, PDGF stimulates a conformational change in the receptor

  2. Novel Drosophila receptor that binds multiple growth factors

    International Nuclear Information System (INIS)

    Rosner, M.R.; Thompson, K.L.; Garcia, V.; Decker, S.J.

    1986-01-01

    The authors have recently reported the identification of a novel growth factor receptor from Drosophila cell cultures that has dual binding specificity for both insulin and epidermal growth factor (EGF). This 100 kDa protein is also antigenically related to the cytoplasmic region of the mammalian EGF receptor-tyrosine kinase. They now report that this protein binds to mammalian nerve growth factor and human transforming growth factor alpha as well as insulin and EGF with apparent dissociation constants ranging from 10 -6 to 10 -8 M. The 100 kDa protein can be affinity-labeled with these 125 I-labeled growth factors after immunoprecipitation with anti-EGF receptor antiserum. These four growth factors appear to share a common binding site, as evidenced by their ability to block affinity labelling by 125 I-insulin. No significant binding to the 100 kDa protein was observed with platelet-derived growth factor, transforming growth factor beta, or glucagon. The 100 kDa Drosophila protein has a unique ligand-binding spectrum with no direct counterpart in mammalian cells and may represent an evolutionary precursor of the mammalian receptors for these growth factors

  3. Assembly and activation of neurotrophic factor receptor complexes.

    Science.gov (United States)

    Simi, Anastasia; Ibáñez, Carlos F

    2010-04-01

    Neurotrophic factors play important roles in the development and function of both neuronal and glial elements of the central and peripheral nervous systems. Their functional diversity is in part based on their ability to interact with alternative complexes of receptor molecules. This review focuses on our current understanding of the mechanisms that govern the assembly and activation of neurotrophic factor receptor complexes. The realization that many, if not the majority, of these complexes exist in a preassembled form at the plasma membrane has forced the revision of classical ligand-mediated oligomerization models, and led to the discovery of novel mechanisms of receptor activation and generation of signaling diversity which are likely to be shared by many different classes of receptors.

  4. Topical administration of adrenergic receptor pharmaceutics and nerve growth factor

    Directory of Open Access Journals (Sweden)

    Jena J Steinle

    2010-06-01

    Full Text Available Jena J SteinleDepartments of Ophthalmology and Anatomy and Neurobiology, Hamilton Eye Institute, University of Tennessee Health Science Center, Memphis, TN 38163, USAAbstract: Topical application of nerve growth factor (NGF and adrenergic receptor pharmaceutics are currently in use for corneal ulcers and glaucoma. A recent interest in the neuroprotective abilities of NGF has led to a renewed interest in NGF as a therapeutic for retinal and choroidal diseases. NGF can promote cell proliferation through actions of the TrkA receptor or promote apoptosis through receptor p75NTR. This understanding has led to novel interest in the role of NGF for diseases of the posterior eye. The role of β-adrenergic receptor agonists and antagonists for treatments of glaucoma, diabetic retinopathy, and their potential mechanisms of action, are still under investigation. This review discusses the current knowledge and applications of topical NGF and adrenergic receptor drugs for ocular disease.Keywords: NGF, β-adrenergic receptor agents, α-adrenergic receptor agents, retina, cornea, glaucoma

  5. A germline RET proto-oncogene mutation in multiple members of an ...

    African Journals Online (AJOL)

    Makia Marafie

    2016-09-17

    Sep 17, 2016 ... The Egyptian Journal of Medical Human Genetics (2017) 18, 193–197. HOSTED BY ... been reported in 85% of tested individuals, nearly 50% of them are amino acid .... [1] Krampitz GW, Norton JA. RET gene mutations ...

  6. Characterization of LAF-4, a Putative Proto-Oncogene Involved in the Development of Breast Cancer

    National Research Council Canada - National Science Library

    Andrulis, Irene

    2001-01-01

    The long range goal of our research is to identify genes involved in the early stages of breast cancer development, specifically genes involved in the transition from hyperplasia to ductal carcinoma in-situ (DCIS...

  7. Direct regulation of the Akt proto-oncogene product by phosphatidylinositol-3,4-bisphosphate.

    Science.gov (United States)

    Franke, T F; Kaplan, D R; Cantley, L C; Toker, A

    1997-01-31

    The regulation of the serine-threonine kinase Akt by lipid products of phosphoinositide 3-kinase (PI 3-kinase) was investigated. Akt activity was found to correlate with the amount of phosphatidylinositol-3,4-bisphosphate (PtdIns-3,4-P2) in vivo, and synthetic PtdIns-3,4-P2 activated Akt both in vitro and in vivo. Binding of PtdIns-3,4-P2 occurred within the Akt pleckstrin homology (PH) domain and facilitated dimerization of Akt. Akt mutated in the PH domain was not activated by PI 3-kinase in vivo or by PtdIns-3, 4-P2 in vitro, and it was impaired in binding to PtdIns-3,4-P2. Examination of the binding to other phosphoinositides revealed that they bound to the Akt PH domain with much lower affinity than did PtdIns-3,4-P2 and failed to increase Akt activity. Thus, Akt is apparently regulated by the direct interaction of PtdIns-3,4-P2 with the Akt PH domain.

  8. Functional Analysis of the Proto-oncogenes Septin9 and Nras

    DEFF Research Database (Denmark)

    Lassen, Louise Berkhoudt

    filaments. Both SEPT7 and SEPT9 containing filaments were intensified under hypoxia in wild type cells compared to non-hypoxic cells despite their transcriptional downregulation. Due to earlier finding of Sept9 as a frequent integration site in T-cell lymphomas induced by retrovirus, the function of Sept9...... the murine leukemia virus Akv 1-99 in either sense or antisense direction. In addition a floxed PGK/Tn5 neomycin cassette was inserted. Expression analysis of Nras within knock in was used to study the effect of the LTR. If inserted before the endogenous promoter, the LTR in the antisense direction was found...... of Nras caused early postnatal lethality of the homozygous mice. A thorough analysis revealed that the homozygous mice suffered from granulocytosis and T-cell expansion within the spleen. The increased population of granulocytes was mainly immature, and subsequently a decrease of monocytes was found...

  9. Insulin and insulin-like growth factor receptors and responses

    International Nuclear Information System (INIS)

    Roth, R.A.; Steele-Perkins, G.; Hari, J.; Stover, C.; Pierce, S.; Turner, J.; Edman, J.C.; Rutter, W.J.

    1988-01-01

    Insulin is a member of a family of structurally related hormones with diverse physiological functions. In humans, the best-characterized members of this family include insulin, insulin-like growth factor (IGF)-I, and IGF-II. Each of these three polypeptide hormones has its own distinct receptor. The structures of each of these receptors have now been deduced from analyses of isolated cDNA clones. To study further the responses mediated through these three different receptors, the authors have been studying cells expressing the proteins encoded by these three cDNAs. The isolated cDNAs have been transfected into Chinese hamster ovary (CHO) cells, and the resulting transfected cell lines have been characterized as to the ligand-binding activities and signal-transducing activities of the expressed proteins

  10. Distribution of corticotropin-releasing factor receptors in primate brain

    International Nuclear Information System (INIS)

    Millan, M.A.; Jacobowitz, D.M.; Hauger, R.L.; Catt, K.J.; Aguilera, G.

    1986-01-01

    The distribution and properties of receptors for corticotropin-releasing factor (CRF) were analyzed in the brain of cynomolgus monkeys. Binding of [ 125 I]tyrosine-labeled ovine CRF to frontal cortex and amygdala membrane-rich fractions was saturable, specific, and time- and temperature-dependent, reaching equilibrium in 30 min at 23 0 C. Scatchard analysis of the binding data indicated one class of high-affinity sites with a K/sub d/ of 1 nM and a concentration of 125 fmol/mg. As in the rat pituitary and brain, CRF receptors in monkey cerebral cortex and amygdala were coupled to adenylate cyclase. Autoradiographic analysis of specific CRF binding in brain sections revealed that the receptors were widely distributed in the cerebral cortex and limbic system. Receptor density was highest in the pars tuberalis of the pituitary and throughout the cerebral cortex, specifically in the prefrontal, frontal, orbital, cingulate, insular, and temporal areas, and in the cerebellar cortex. A low binding density was present in the superior colliculus, locus coeruleus, substantia gelatinosa, preoptic area, septal area, and bed nucleus of the stria terminalis. These data demonstrate that receptors for CRF are present within the primate brain at areas related to the central control of visceral function and behavior, suggesting that brain CRF may serve as a neurotransmitter in the coordination of endocrine and neural mechanisms involved in the response to stress

  11. Platelet-derived growth factor receptors in the human central nervous system : autoradiographic distribution and receptor densities in multiple sclerosis

    NARCIS (Netherlands)

    De Keyser, J; Wilczak, N

    1997-01-01

    Platelet derived growth factor (PDGF) receptors were studied in postmortem adult human brain and cervical spinal cord using autoradiography with human recombinant I-125-PDGF-BB. PDGF-BB binds to the three different dimers of PDGF receptors (alpha alpha, alpha beta and beta beta) PDGF receptors were

  12. Epidermal growth factor receptor expression in urinary bladder cancer

    Directory of Open Access Journals (Sweden)

    Dayalu S.L. Naik

    2011-01-01

    Full Text Available Objective : To evaluate the expression pattern of epidermal growth factor receptor (EGFR in urinary bladder cancer and its association with human epidermal growth factor receptor 2 (HER2, epidermal growth factor (EGF, interleukin-6 (IL-6, and high risk human papilloma virus (HPV types 16 and 18. Materials and Methods : Thirty cases of urothelial carcinoma were analyzed. EGFR, HER2, EGF, and IL-6 expressions in the tissue were evaluated by immunohistochemical staining. For HPV, DNA from tissue samples was extracted and detection of HPV was done by PCR technique. Furthermore, evaluation of different intracellular molecules associated with EGFR signaling pathways was performed by the western blot method using lysates from various cells and tissues. Results : In this study, the frequencies of immunopositivity for EGFR, HER2, EGF, and IL-6 were 23%, 60%, 47%, and 80%, respectively. No cases were positive for HPV-18, whereas HPV-16 was detected in 10% cases. Overall, expression of EGFR did not show any statistically significant association with the studied parameters. However, among male patients, a significant association was found only between EGFR and HER2. Conclusions : Overexpression of EGFR and/or HER2, two important members of the same family of growth factor receptors, was observed in a considerable proportion of cases. Precise knowledge in this subject would be helpful to formulate a rational treatment strategy in patients with urinary bladder cancer.

  13. Topical administration of adrenergic receptor pharmaceutics and nerve growth factor

    OpenAIRE

    Steinle, Jena

    2010-01-01

    Jena J SteinleDepartments of Ophthalmology and Anatomy and Neurobiology, Hamilton Eye Institute, University of Tennessee Health Science Center, Memphis, TN 38163, USAAbstract: Topical application of nerve growth factor (NGF) and adrenergic receptor pharmaceutics are currently in use for corneal ulcers and glaucoma. A recent interest in the neuroprotective abilities of NGF has led to a renewed interest in NGF as a therapeutic for retinal and choroidal diseases. NGF can promote cell proliferati...

  14. Multiple autophosphorylation sites of the epidermal growth factor receptor are essential for receptor kinase activity and internalization. Contrasting significance of tyrosine 992 in the native and truncated receptors

    DEFF Research Database (Denmark)

    Sorkin, A; Helin, K; Waters, C M

    1992-01-01

    The role of epidermal growth factor (EGF) receptor autophosphorylation sites in the regulation of receptor functions has been studied using cells transfected with mutant EGF receptors. Simultaneous point mutation of 4 tyrosines (Y1068, Y1086, Y1148, Y1173) to phenylalanine, as well as removal of ...

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

    NARCIS (Netherlands)

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

    2013-01-01

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

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

    International Nuclear Information System (INIS)

    Berasain, Carmen; Latasa, María Ujue; Urtasun, Raquel; Goñi, Saioa; Elizalde, María; Garcia-Irigoyen, Oihane; Azcona, María; Prieto, Jesús; Ávila, Matías A.

    2011-01-01

    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

  17. Epidermal growth factor receptor in primary human lung cancer

    International Nuclear Information System (INIS)

    Yu Xueyan; Hu Guoqiang; Tian Keli; Wang Mingyun

    1996-01-01

    Cell membranes were prepared from 12 human lung cancers for the study of the expression of epidermal growth factor receptors (EGFR). EGFR concentration was estimated by ligand binding studies using 125 I-radiolabeled EGF. The dissociation constants of the high affinity sites were identical, 1.48 nmol and 1.1 nmol in cancer and normal lung tissues, the EGFR contents were higher in lung cancer tissues (range: 2.25 to 19.39 pmol·g -1 membrane protein) than that in normal tissues from the same patients (range: 0.72 to 7.43 pmol·g -1 membrane protein). These results suggest that EGF and its receptor may play a role in the regulatory mechanisms in the control of lung cellular growth and tumor promotion

  18. Tyrosine 769 of the keratinocyte growth factor receptor is required for receptor signaling but not endocytosis

    International Nuclear Information System (INIS)

    Ceridono, Mara; Belleudi, Francesca; Ceccarelli, Simona; Torrisi, Maria Rosaria

    2005-01-01

    Keratinocyte growth factor receptor (KGFR) is a receptor tyrosine kinase expressed on epithelial cells which belongs to the family of fibroblast growth factor receptors (FGFRs). Following ligand binding, KGFR is rapidly autophosphorylated on specific tyrosine residues in the intracellular domain, recruits substrate proteins, and is rapidly internalized by clathrin-mediated endocytosis. The role of different autophosphorylation sites in FGFRs, and in particular the role of the tyrosine 766 in FGFR1, first identified as PLCγ binding site, has been extensively studied. We analyzed here the possible role of the tyrosine 769 in KGFR, corresponding to tyrosine 766 in FGFR1, in the regulation of KGFR signal transduction and MAPK activation as well as in the control of the endocytic process of KGFR. A mutant KGFR in which tyrosine 769 was substituted by phenylalanine was generated and transfected in NIH3T3 and HeLa cells. Our results indicate that tyrosine 769 is required for the binding to KGFR and tyrosine phosphorylation of PLCγ as well as for the full activation of MAPKs and for cell proliferation through the regulation of FRS2 tyrosine phosphorylation, suggesting that this residue represents a key regulator of KGFR signal transduction. Our data also show that tyrosine 769 is not involved in the regulation of the endocytic process of KGFR

  19. Epidermal growth factor and its receptors in human pancreatic carcinoma

    International Nuclear Information System (INIS)

    Chen, Y.F.; Pan, G.Z.; Hou, X.; Liu, T.H.; Chen, J.; Yanaihara, C.; Yanaihara, N.

    1990-01-01

    The role of epidermal growth factor (EGF) in oncogenesis and progression of malignant tumors is a subject of vast interest. In this study, radioimmunoassay and radioreceptor assay of EGF were established. EGF contents in malignant and benign pancreatic tumors, in normal pancreas tissue, and in culture media of a human pancreatic carcinoma cell line were determined. EGF receptor binding studies were performed. It was shown that EGF contents in pancreatic carcinomas were significantly higher than those in normal pancreas or benign pancreatic tumors. EGF was also detected in the culture medium of a pancreatic carcinoma cell line. The binding of 125I-EGF to the pancreatic carcinoma cells was time and temperature dependent, reversible, competitive, and specific. Scatchard analysis showed that the dissociation constant of EGF receptor was 2.1 X 10(-9) M, number of binding sites was 1.3 X 10(5) cell. These results indicate that there is an over-expression of EGF/EGF receptors in pancreatic carcinomas, and that an autocrine regulatory mechanism may exist in the growth-promoting effect of EGF on tumor cells

  20. Expression of epidermal growth factor receptors in human endometrial carcinoma

    DEFF Research Database (Denmark)

    Nyholm, H C; Nielsen, Anette Lynge; Ottesen, B

    1993-01-01

    Little data exist on the expression of epidermal growth factor receptors (EGF-Rs) in human endometrial cancer. EGF-R status was studied in 65 patients with endometrial carcinomas and in 26 women with nonmalignant postmenopausal endometria, either inactive/atrophic endometrium or adenomatous...... hyperplasia. EGF-R was identified on frozen tissue sections by means of an indirect immunoperoxidase technique with a monoclonal antibody against the external domain of the EGF-R. Seventy-one percent of the carcinomas expressed positive EGF-R immunoreactivity. In general, staining was most prominent...

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

    DEFF Research Database (Denmark)

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

    1997-01-01

    The epidermal growth factor receptor (EGFR) is a growth factor receptor that induces cell differentiation and proliferation upon activation through the binding of one of its ligands. The receptor is located at the cell surface, where the binding of a ligand activates a tyrosine kinase in the intr...... aspects of therapeutic targeting of EGFR....

  2. Changing the insulin receptor to possess insulin-like growth factor I ligand specificity

    International Nuclear Information System (INIS)

    Andersen, A.S.; Kjeldsen, T.; Wiberg, F.C.; Christensen, P.M.; Rasmussen, J.S.; Norris, K.; Moeller, K.B.; Moeller, N.P.H.

    1990-01-01

    To examine the role of the N-terminal part of the insulin-like growth factor I (IGF-I) receptor and insulin receptor in determining ligand specificity, the authors prepared an expression vector encoding a hybrid receptor where exon 1 (encoding the signal peptide and seven amino acids of the α-subunit), exon 2, and exon 3 of the insulin receptor were replaced with the corresponding IGF-I receptor cDNA (938 nucleotides). To allow direct quantitative comparison of the binding capabilities of this hybrid receptor with those of the human IGF-I receptor and the insulin receptor, all three receptors were expressed in baby hamster kidney (BHK) cells as soluble molecules and partially purified before characterization. The hybrid IGF-I/insulin receptor bound IGF-I with an affinity comparable to that of the wild-type IGF-I receptor. In contrast, the hybrid receptor no longer displayed high-affinity binding of insulin. These results directly demonstrate that it is possible to change the specificity of the insulin receptor to that of the IGF-I receptor and, furthermore, that the binding specificity for IGF-I is encoded within the nucleotide sequence from 135 to 938 of the IGF-I receptor cDNA. Since the hybrid receptor only bound insulin with low affinity, the insulin binding region is likely to be located within exons 2 and 3 of the insulin receptor

  3. Expression of nerve growth factor and its receptor, tyrosine kinase receptor A, in rooster testes.

    Science.gov (United States)

    Ma, Wei; Wang, Chunqiang; Su, Yuhong; Tian, Yumin; Zhu, Hongyan

    2015-10-01

    Nerve growth factor (NGF), which is required for the survival and differentiation of the nervous system, is also thought to play an important role in the development of mammalian reproductive tissues. To explore the function of NGF in the male reproductive system of non-mammalian animals, we determined the presence of NGF and its receptor, tyrosine kinase receptor A (TrkA), in rooster testes and investigated the regulation of NGF and TrkA expression by follicle-stimulating hormone (FSH). The mRNA and protein levels of NGF and TrkA in 6-week-old rooster testes were lower than those in 12-, 16- or 20-week age groups; levels were highest in the 16-week group. Immunohistochemistry showed that NGF and TrkA were both detected in spermatogonia, spermatocytes and spermatids. NGF immunoreactivity was observed in Leydig cells and strong TrkA signals were present in Sertoli cells. Meanwhile, FSH increased TrkA transcript levels in rooster testes in a dose-dependent manner. We present novel evidence for the developmental and FSH-regulated expression of the NGF/TrkA system, and our findings suggest that the NGF/TrkA system may play a prominent role in chicken spermatogenesis. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. Personalized Radiation Oncology: Epidermal Growth Factor Receptor and Other Receptor Tyrosine Kinase Inhibitors.

    Science.gov (United States)

    Higgins, Geoff S; Krause, Mechthild; McKenna, W Gillies; Baumann, Michael

    Molecular biomarkers are currently evaluated in preclinical and clinical studies in order to establish predictors for treatment decisions in radiation oncology. The receptor tyrosine kinases (RTK) are described in the following text. Among them, the most data are available for the epidermal growth factor receptor (EGFR) that plays a major role for prognosis of patients after radiotherapy, but seems also to be involved in mechanisms of radioresistance, specifically in repopulation of tumour cells between radiotherapy fractions. Monoclonal antibodies against the EGFR improve locoregional tumour control and survival when applied during radiotherapy, however, the effects are heterogeneous and biomarkers for patient selection are warranted. Also other RTK´s such as c-Met and IGF-1R seem to play important roles in tumour radioresistance. Beside the potential to select patients for molecular targeting approaches combined with radiotherapy, studies are also needed to evluate radiotherapy adaptation approaches for selected patients, i.e. adaptation of radiation dose, or, more sophisticated, of target volumes.

  5. Nerve growth factor receptor immunostaining suggests an extrinsic origin for hypertrophic nerves in Hirschsprung's disease.

    OpenAIRE

    Kobayashi, H; O'Briain, D S; Puri, P

    1994-01-01

    The expression of nerve growth factor receptor in colon from 20 patients with Hirshsprung's disease and 10 controls was studied immunohistochemically. The myenteric and submucous plexuses in the ganglionic bowel and hypertrophic nerve trunks in the aganglionic bowel displayed strong expression of nerve growth factor receptor. The most important finding was the identical localisation of nerve growth factor receptor immunoreactivity on the perineurium of both hypertrophic nerve trunks in Hirshs...

  6. Antibody-induced dimerization activates the epidermal growth factor receptor tyrosine kinase

    NARCIS (Netherlands)

    Spaargaren, M.; Defize, L. H.; Boonstra, J.; de Laat, S. W.

    1991-01-01

    The relationship between epidermal growth factor receptor (EGF-R) protein tyrosine kinase activation and ligand-induced receptor dimerization was investigated using several bivalent anti-EGF-R antibodies directed against various receptor epitopes. In A431 membrane preparations and permeabilized

  7. Arctigenin induced gallbladder cancer senescence through modulating epidermal growth factor receptor pathway.

    Science.gov (United States)

    Zhang, Mingdi; Cai, Shizhong; Zuo, Bin; Gong, Wei; Tang, Zhaohui; Zhou, Di; Weng, Mingzhe; Qin, Yiyu; Wang, Shouhua; Liu, Jun; Ma, Fei; Quan, Zhiwei

    2017-05-01

    Gallbladder cancer has poor prognosis and limited therapeutic options. Arctigenin, a representative dibenzylbutyrolactone lignan, occurs in a variety of plants. However, the molecular mechanisms involved in the antitumor effect of arctigenin on gallbladder cancer have not been fully elucidated. The expression levels of epidermal growth factor receptor were examined in 100 matched pairs of gallbladder cancer tissues. A positive correlation between high epidermal growth factor receptor expression levels and poor prognosis was observed in gallbladder cancer tissues. Pharmacological inhibition or inhibition via RNA interference of epidermal growth factor receptor induced cellular senescence in gallbladder cancer cells. The antitumor effect of arctigenin on gallbladder cancer cells was primarily achieved by inducing cellular senescence. In gallbladder cancer cells treated with arctigenin, the expression level of epidermal growth factor receptor significantly decreased. The analysis of the activity of the kinases downstream of epidermal growth factor receptor revealed that the RAF-MEK-ERK signaling pathway was significantly inhibited. Furthermore, the cellular senescence induced by arctigenin could be reverted by pcDNA-epidermal growth factor receptor. Arctigenin also potently inhibited the growth of tumor xenografts, which was accompanied by the downregulation of epidermal growth factor receptor and induction of senescence. This study demonstrates arctigenin could induce cellular senescence in gallbladder cancer through the modulation of epidermal growth factor receptor pathway. These data identify epidermal growth factor receptor as a key regulator in arctigenin-induced gallbladder cancer senescence.

  8. Developmental regulation of human truncated nerve growth factor receptor

    Energy Technology Data Exchange (ETDEWEB)

    DiStefano, P.S.; Clagett-Dame, M.; Chelsea, D.M.; Loy, R. (Abbott Laboratories, Abbott Park, IL (USA))

    1991-01-01

    Monoclonal antibodies (designated XIF1 and IIIG5) recognizing distinct epitopes of the human truncated nerve growth factor receptor (NGF-Rt) were used in a two-site radiometric immunosorbent assay to monitor levels of NGF-Rt in human urine as a function of age. Urine samples were collected from 70 neurologically normal subjects ranging in age from 1 month to 68 years. By using this sensitive two-site radiometric immunosorbent assay, NGF-Rt levels were found to be highest in urine from 1-month old subjects. By 2.5 months, NGF-Rt values were half of those seen at 1 month and decreased more gradually between 0.5 and 15 years. Between 15 and 68 years, urine NGF-Rt levels were relatively constant at 5% of 1-month values. No evidence for diurnal variation of adult NGF-Rt was apparent. Pregnant women in their third trimester showed significantly elevated urine NGF-Rt values compared with age-matched normals. Affinity labeling of NGF-Rt with 125I-NGF followed by immunoprecipitation with ME20.4-IgG and gel autoradiography indicated that neonatal urine contained high amounts of truncated receptor (Mr = 50 kd); decreasingly lower amounts of NGF-Rt were observed on gel autoradiograms with development, indicating that the two-site radiometric immunosorbent assay correlated well with the affinity labeling technique for measuring NGF-Rt. NGF-Rt in urines from 1-month-old and 36-year-old subjects showed no differences in affinities for NGF or for the monoclonal antibody IIIG5. These data show that NGF-Rt is developmentally regulated in human urine, and are discussed in relation to the development and maturation of the peripheral nervous system.

  9. Developmental regulation of human truncated nerve growth factor receptor

    International Nuclear Information System (INIS)

    DiStefano, P.S.; Clagett-Dame, M.; Chelsea, D.M.; Loy, R.

    1991-01-01

    Monoclonal antibodies (designated XIF1 and IIIG5) recognizing distinct epitopes of the human truncated nerve growth factor receptor (NGF-Rt) were used in a two-site radiometric immunosorbent assay to monitor levels of NGF-Rt in human urine as a function of age. Urine samples were collected from 70 neurologically normal subjects ranging in age from 1 month to 68 years. By using this sensitive two-site radiometric immunosorbent assay, NGF-Rt levels were found to be highest in urine from 1-month old subjects. By 2.5 months, NGF-Rt values were half of those seen at 1 month and decreased more gradually between 0.5 and 15 years. Between 15 and 68 years, urine NGF-Rt levels were relatively constant at 5% of 1-month values. No evidence for diurnal variation of adult NGF-Rt was apparent. Pregnant women in their third trimester showed significantly elevated urine NGF-Rt values compared with age-matched normals. Affinity labeling of NGF-Rt with 125I-NGF followed by immunoprecipitation with ME20.4-IgG and gel autoradiography indicated that neonatal urine contained high amounts of truncated receptor (Mr = 50 kd); decreasingly lower amounts of NGF-Rt were observed on gel autoradiograms with development, indicating that the two-site radiometric immunosorbent assay correlated well with the affinity labeling technique for measuring NGF-Rt. NGF-Rt in urines from 1-month-old and 36-year-old subjects showed no differences in affinities for NGF or for the monoclonal antibody IIIG5. These data show that NGF-Rt is developmentally regulated in human urine, and are discussed in relation to the development and maturation of the peripheral nervous system

  10. Analysis of receptor signaling pathways by mass spectrometry: identification of vav-2 as a substrate of the epidermal and platelet-derived growth factor receptors

    DEFF Research Database (Denmark)

    Pandey, A; Podtelejnikov, A V; Blagoev, B

    2000-01-01

    Oligomerization of receptor protein tyrosine kinases such as the epidermal growth factor receptor (EGFR) by their cognate ligands leads to activation of the receptor. Transphosphorylation of the receptor subunits is followed by the recruitment of signaling molecules containing src homology 2 (SH2...

  11. Development of real-time reverse transcription polymerase chain reaction assays to quantify insulin-like growth factor receptor and insulin receptor expression in equine tissue

    Directory of Open Access Journals (Sweden)

    Stephen B. Hughes

    2013-08-01

    Full Text Available The insulin-like growth factor system (insulin-like growth factor 1, insulin-like growth factor 2, insulin-like growth factor 1 receptor, insulin-like growth factor 2 receptor and six insulin-like growth factor-binding proteins and insulin are essential to muscle metabolism and most aspects of male and female reproduction. Insulin-like growth factor and insulin play important roles in the regulation of cell growth, differentiation and the maintenance of cell differentiation in mammals. In order to better understand the local factors that regulate equine physiology, such as muscle metabolism and reproduction (e.g., germ cell development and fertilisation, real-time reverse transcription polymerase chain reaction assays for quantification of equine insulin-like growth factor 1 receptor and insulin receptor messenger ribonucleic acid were developed. The assays were sensitive: 192 copies/µLand 891 copies/µL for insulin-like growth factor 1 receptor, messenger ribonucleic acid and insulin receptor respectively (95%limit of detection, and efficient: 1.01 for the insulin-like growth factor 1 receptor assay and 0.95 for the insulin receptor assay. The assays had a broad linear range of detection (seven logs for insulin-like growth factor 1 receptor and six logs for insulin receptor. This allowed for analysis of very small amounts of messenger ribonucleic acid. Low concentrations of both insulin-like growth factor 1 receptor and insulin receptor messenger ribonucleic acid were detected in endometrium, lung and spleen samples, whilst high concentrations were detected in heart, muscle and kidney samples, this was most likely due to the high level of glucose metabolism and glucose utilisation by these tissues. The assays developed for insulin-like growth factor 1 receptor and insulin receptor messenger ribonucleic acid expression have been shown to work on equine tissue and will contribute to the understanding of insulin and insulin-like growth factor 1

  12. Glycosylation as a Main Regulator of Growth and Death Factor Receptors Signaling

    Directory of Open Access Journals (Sweden)

    Inês Gomes Ferreira

    2018-02-01

    Full Text Available Glycosylation is a very frequent and functionally important post-translational protein modification that undergoes profound changes in cancer. Growth and death factor receptors and plasma membrane glycoproteins, which upon activation by extracellular ligands trigger a signal transduction cascade, are targets of several molecular anti-cancer drugs. In this review, we provide a thorough picture of the mechanisms bywhich glycosylation affects the activity of growth and death factor receptors in normal and pathological conditions. Glycosylation affects receptor activity through three non-mutually exclusive basic mechanisms: (1 by directly regulating intracellular transport, ligand binding, oligomerization and signaling of receptors; (2 through the binding of receptor carbohydrate structures to galectins, forming a lattice thatregulates receptor turnover on the plasma membrane; and (3 by receptor interaction with gangliosides inside membrane microdomains. Some carbohydrate chains, for example core fucose and β1,6-branching, exert a stimulatory effect on all receptors, while other structures exert opposite effects on different receptors or in different cellular contexts. In light of the crucial role played by glycosylation in the regulation of receptor activity, the development of next-generation drugs targeting glyco-epitopes of growth factor receptors should be considered a therapeutically interesting goal.

  13. Epidermal growth factor receptor mutation in gastric cancer.

    Science.gov (United States)

    Liu, Zhimin; Liu, Lina; Li, Mei; Wang, Zhaohui; Feng, Lu; Zhang, Qiuping; Cheng, Shihua; Lu, Shen

    2011-04-01

    Epidermal growth factor receptor (EGFR) and Kirsten-RAS (KRAS) mutations have been identified as predictors of response to EGFR tyrosine kinase inhibitors (TKIs) in non-small cell lung cancer. We aimed to screen the mutations of both genes in gastric carcinoma to detect the suitability of EGFR TKIs for patients with gastric carcinoma. We screened EGFR mutation in exons 19-21 and KRAS mutation in exon 2 in 58 gastric adenocarcinomas from China using high resolution melting analysis (HRMA). Positive samples were confirmed by DNA sequencing. Three EGFR missense mutations (5.2%) and 22 single nucleotide polymorphisms (SNP, Q787Q, 37.9%) were identified. To our knowledge, we report for the first time three mutation patterns of EGFR, Y801C, L858R and G863D, in gastric carcinoma. Two samples with EGFR mutation were mucinous adenocarcinoma. These three samples were collected from male patients aged over 75 years old. The frequency of KRAS mutation was 10.3% (6/58). The exclusiveness of EGFR and KRAS mutations was proven for the first time in gastric cancer. Gastric carcinoma of the mucinous adenocarcinoma type collected from older male patients may harbour EGFR mutations. The small subset of gastric adenocarcinoma patients may respond to EGFR TKIs.

  14. Association of coatomer proteins with the beta-receptor for platelet-derived growth factor

    DEFF Research Database (Denmark)

    Hansen, Klaus; Rönnstrand, L; Rorsman, C

    1997-01-01

    The nonreceptor tyrosine kinase Src binds to and is activated by the beta-receptor for platelet-derived growth factor (PDGF). The interaction leads to Src phosphorylation of Tyr934 in the kinase domain of the receptor. In the course of the functional characterization of this phosphorylation, we...... of intracellular vesicle transport. In order to explore the functional significance of the interaction between alpha- and beta'-COP and the PDGF receptor, a receptor mutant was made in which the conserved histidine residue 928 was mutated to an alanine residue. The mutant receptor, which was unable to bind alpha...

  15. The Pseudo signal peptide of the corticotropin-releasing factor receptor type 2A prevents receptor oligomerization.

    Science.gov (United States)

    Teichmann, Anke; Rutz, Claudia; Kreuchwig, Annika; Krause, Gerd; Wiesner, Burkhard; Schülein, Ralf

    2012-08-03

    N-terminal signal peptides mediate the interaction of native proteins with the translocon complex of the endoplasmic reticulum membrane and are cleaved off during early protein biogenesis. The corticotropin-releasing factor receptor type 2a (CRF(2(a))R) possesses an N-terminal pseudo signal peptide, which represents a so far unique domain within the large protein family of G protein-coupled receptors (GPCRs). In contrast to a conventional signal peptide, the pseudo signal peptide remains uncleaved and consequently forms a hydrophobic extension at the N terminus of the receptor. The functional consequence of the presence of the pseudo signal peptide is not understood. Here, we have analyzed the significance of this domain for receptor dimerization/oligomerization in detail. To this end, we took the CRF(2(a))R and the homologous corticotropin-releasing factor receptor type 1 (CRF(1)R) possessing a conventional cleaved signal peptide and conducted signal peptide exchange experiments. Using single cell and single molecule imaging methods (fluorescence resonance energy transfer and fluorescence cross-correlation spectroscopy, respectively) as well as biochemical experiments, we obtained two novel findings; we could show that (i) the CRF(2(a))R is expressed exclusively as a monomer, and (ii) the presence of the pseudo signal peptide prevents its oligomerization. Thus, we have identified a novel functional domain within the GPCR protein family, which plays a role in receptor oligomerization and which may be useful to study the functional significance of this process in general.

  16. A transcription factor active on the epidermal growth factor receptor gene

    International Nuclear Information System (INIS)

    Kageyama, R.; Merlino, G.T.; Pastan, I.

    1988-01-01

    The authors have developed an in vitro transcription system for the epidermal growth factor receptor (EGFR) oncogene by using nuclear extracts of A431 human epidermoid carcinoma cells, which overproduce EGFR. They found that a nuclear factor, termed EGFR-specific transcription factor (ETF), specifically stimulated EGFR transcription by 5- to 10-fold. In this report, ETF, purified by using sequence-specific oligonucleotide affinity chromatography, is shown by renaturing material eluted from a NaDodSO 4 /polyacrylamide gel to be a protein with a molecular mass of 120 kDa. ETF binds to the promoter region, as measured by DNase I footprinting and gel-mobility-shift assays, and specifically stimulates the transcription of the EGFR gene in a reconstituted in vitro transcription system. These results suggest that ETF could play a role in the overexpression of the cellular oncogene EGFR

  17. Phenobarbital indirectly activates the constitutive active androstane receptor (CAR) by inhibition of epidermal growth factor receptor signaling.

    Science.gov (United States)

    Mutoh, Shingo; Sobhany, Mack; Moore, Rick; Perera, Lalith; Pedersen, Lee; Sueyoshi, Tatsuya; Negishi, Masahiko

    2013-05-07

    Phenobarbital is a central nervous system depressant that also indirectly activates nuclear receptor constitutive active androstane receptor (CAR), which promotes drug and energy metabolism, as well as cell growth (and death), in the liver. We found that phenobarbital activated CAR by inhibiting epidermal growth factor receptor (EGFR) signaling. Phenobarbital bound to EGFR and potently inhibited the binding of EGF, which prevented the activation of EGFR. This abrogation of EGFR signaling induced the dephosphorylation of receptor for activated C kinase 1 (RACK1) at Tyr(52), which then promoted the dephosphorylation of CAR at Thr(38) by the catalytic core subunit of protein phosphatase 2A. The findings demonstrated that the phenobarbital-induced mechanism of CAR dephosphorylation and activation is mediated through its direct interaction with and inhibition of EGFR.

  18. Host factors that modify Plasmodium falciparum adhesion to endothelial receptors.

    Science.gov (United States)

    Mahamar, Almahamoudou; Attaher, Oumar; Swihart, Bruce; Barry, Amadou; Diarra, Bacary S; Kanoute, Moussa B; Cisse, Kadidia B; Dembele, Adama B; Keita, Sekouba; Gamain, Benoît; Gaoussou, Santara; Issiaka, Djibrilla; Dicko, Alassane; Duffy, Patrick E; Fried, Michal

    2017-10-24

    P. falciparum virulence is related to adhesion and sequestration of infected erythrocytes (IE) in deep vascular beds, but the endothelial receptors involved in severe malaria remain unclear. In the largest ever study of clinical isolates, we surveyed adhesion of freshly collected IE from children under 5 years of age in Mali to identify novel vascular receptors, and examined the effects of host age, hemoglobin type, blood group and severe malaria on levels of IE adhesion to a panel of endothelial receptors. Several novel molecules, including integrin α3β1, VE-cadherin, ICAM-2, junctional adhesion molecule-B (JAM-B), laminin, and cellular fibronectin, supported binding of IE from children. Severe malaria was not significantly associated with levels of IE adhesion to any of the 19 receptors. Hemoglobin AC, which reduces severe malaria risk, reduced IE binding to the receptors CD36 and integrin α5β1, while hemoglobin AS did not modify IE adhesion to any receptors. Blood groups A, AB and B significantly reduced IE binding to ICAM-1. Severe malaria risk varies with age, but age significantly impacted the level of IE binding to only a few receptors: IE binding to JAM-B decreased with age, while binding to CD36 and integrin α5β1 significantly increased with age.

  19. Targeting fibroblast growth factor receptor signaling inhibits prostate cancer progression.

    Science.gov (United States)

    Feng, Shu; Shao, Longjiang; Yu, Wendong; Gavine, Paul; Ittmann, Michael

    2012-07-15

    Extensive correlative studies in human prostate cancer as well as studies in vitro and in mouse models indicate that fibroblast growth factor receptor (FGFR) signaling plays an important role in prostate cancer progression. In this study, we used a probe compound for an FGFR inhibitor, which potently inhibits FGFR-1-3 and significantly inhibits FGFR-4. The purpose of this study is to determine whether targeting FGFR signaling from all four FGFRs will have in vitro activities consistent with inhibition of tumor progression and will inhibit tumor progression in vivo. Effects of AZ8010 on FGFR signaling and invasion were analyzed using immortalized normal prostate epithelial (PNT1a) cells and PNT1a overexpressing FGFR-1 or FGFR-4. The effect of AZ8010 on invasion and proliferation in vitro was also evaluated in prostate cancer cell lines. Finally, the impact of AZ8010 on tumor progression in vivo was evaluated using a VCaP xenograft model. AZ8010 completely inhibits FGFR-1 and significantly inhibits FGFR-4 signaling at 100 nmol/L, which is an achievable in vivo concentration. This results in marked inhibition of extracellular signal-regulated kinase (ERK) phosphorylation and invasion in PNT1a cells expressing FGFR-1 and FGFR-4 and all prostate cancer cell lines tested. Treatment in vivo completely inhibited VCaP tumor growth and significantly inhibited angiogenesis and proliferation and increased cell death in treated tumors. This was associated with marked inhibition of ERK phosphorylation in treated tumors. Targeting FGFR signaling is a promising new approach to treating aggressive prostate cancer.

  20. Human corpus luteum: presence of epidermal growth factor receptors and binding characteristics

    International Nuclear Information System (INIS)

    Ayyagari, R.R.; Khan-Dawood, F.S.

    1987-01-01

    Epidermal growth factor receptors are present in many reproductive tissues but have not been demonstrated in the human corpus luteum. To determine the presence of epidermal growth factor receptors and its binding characteristics, we carried out studies on the plasma cell membrane fraction of seven human corpora lutea (days 16 to 25) of the menstrual cycle. Specific epidermal growth factor receptors were present in human corpus luteum. Insulin, nerve growth factor, and human chorionic gonadotropin did not competitively displace epidermal growth factor binding. The optimal conditions for corpus luteum-epidermal growth factor receptor binding were found to be incubation for 2 hours at 4 degrees C with 500 micrograms plasma membrane protein and 140 femtomol 125 I-epidermal growth factor per incubate. The number (mean +/- SEM) of epidermal growth factor binding sites was 12.34 +/- 2.99 X 10(-19) mol/micrograms protein; the dissociation constant was 2.26 +/- 0.56 X 10(-9) mol/L; the association constant was 0.59 +/- 0.12 X 10(9) L/mol. In two regressing corpora lutea obtained on days 2 and 3 of the menstrual cycle, there was no detectable specific epidermal growth factor receptor binding activity. Similarly no epidermal growth factor receptor binding activity could be detected in ovarian stromal tissue. Our findings demonstrate that specific receptors for epidermal growth factor are present in the human corpus luteum. The physiologic significance of epidermal growth factor receptors in human corpus luteum is unknown, but epidermal growth factor may be involved in intragonadal regulation of luteal function

  1. Napsin A and Thyroid Transcription Factor-1-Positive Cerebellar Tumor with Epidermal Growth Factor Receptor Mutation

    Directory of Open Access Journals (Sweden)

    Taiji Kuwata

    2011-12-01

    Full Text Available We present a very rare case of cerebellar metastasis of unknown origin, in which a primary lung adenocarcinoma was diagnosed by pathological examination of a cerebellar metastatic tumor, using immunohistochemical markers and epidermal growth factor receptor (EGFR mutation of primary lung cancer. A 69-year-old woman was admitted to our hospital because of a hemorrhagic cerebellar tumor and multiple small brain tumors. She underwent cerebellar tumor resection. On pathological examination, the tumor was diagnosed as adenocarcinoma. However, the primary tumor site was unidentifiable even with several imaging inspections. On immunohistochemical analysis, the resected tumor was positive for napsin A and thyroid transcription factor-1. In addition, an EGFR mutation was detected in the tumor. Therefore, primary lung cancer was diagnosed and the patient was started on gefitinib (250 mg/day therapy.

  2. Oxygen dependency of epidermal growth factor receptor binding and DNA synthesis of rat hepatocytes

    International Nuclear Information System (INIS)

    Hirose, Tetsuro; Terajima, Hiroaki; Yamauchi, Akira

    1997-01-01

    Background/Aims: Changes in oxygen availability modulate replicative responses in several cell types, but the effects on hepatocyte replication remain unclear. We have studied the effects of transient nonlethal hypoxia on epidermal growth factor receptor binding and epidermal growth factor-induced DNA synthesis of rat hepatocytes. Methods: Lactate dehydrogenase activity in culture supernatant, intracellular adenosine triphosphate content, 125 I-epidermal growth factor specific binding, epidermal growth factor receptor protein expression, and 3 H-thymidine incorporation were compared between hepatocytes cultured in hypoxia and normoxia. Results: Hypoxia up to 3 h caused no significant increase in lactate dehydrogenase activity in the culture supernatant, while intracellular adenosine triphosphate content decreased time-dependently and was restored to normoxic levels by reoxygenation (nonlethal hypoxia). Concomitantly, 125 I-epidermal growth factor specific binding to hepatocytes decreased time-dependently (to 54.1% of normoxia) and was restored to control levels by reoxygenation, although 125 I-insulin specific binding was not affected. The decrease in 125 I-epidermal growth factor specific binding was explained by the decrease in the number or available epidermal growth factor receptors (21.37±3.08 to 12.16±1.42 fmol/10 5 cells), while the dissociation constant of the receptor was not affected. The change in the number of available receptors was not considered to be due to receptor degradation-resynthesis, since immuno-detection of the epidermal growth factor receptor revealed that the receptor protein expression did not change during hypoxia and reoxygenation, and since neither actinomycin D nor cycloheximide affected the recovery of 125 I-epidermal growth factor binding by reoxygenation. Inhibition of epidermal growth factor-induced DNA synthesis after hypoxia (to 75.4% of normoxia by 3 h hypoxia) paralleled the decrease in 125 I-epidermal growth factor binding

  3. Hepatocyte and keratinocyte growth factors and their receptors in human lung emphysema

    Directory of Open Access Journals (Sweden)

    Marchal Joëlle

    2005-10-01

    Full Text Available Abstract Background Hepatocyte and keratinocyte growth factors are key growth factors in the process of alveolar repair. We hypothesized that excessive alveolar destruction observed in lung emphysema involves impaired expression of hepatocyte and keratinocyte growth factors or their respective receptors, c-met and keratinocyte growth factor receptor. The aim of our study was to compare the expression of hepatocyte and keratinocyte growth factors and their receptors in lung samples from 3 groups of patients: emphysema; smokers without emphysema and non-smokers without emphysema. Methods Hepatocyte and keratinocyte growth factor proteins were analysed by immunoassay and western blot; mRNA expression was measured by real time quantitative polymerase chain reaction. Results Hepatocyte and keratinocyte growth factors, c-met and keratinocyte growth factor receptor mRNA levels were similar in emphysema and non-emphysema patients. Hepatocyte growth factor mRNA correlated negatively with FEV1 and the FEV1/FVC ratio both in emphysema patients and in smokers with or without emphysema. Hepatocyte and keratinocyte growth factor protein concentrations were similar in all patients' groups. Conclusion The expression of hepatocyte and keratinocyte growth factors and their receptors is preserved in patients with lung emphysema as compared to patients without emphysema. Hepatocyte growth factor mRNA correlates with the severity of airflow obstruction in smokers.

  4. Receptores do factor estimulante de colónias de macrófagos do robalo

    OpenAIRE

    Oliveira, Márcio Adriano Guiomar de

    2010-01-01

    O receptor do factor estimulante de colónias de macrófagos, também conhecido como receptor do factor estimulante de colónias-1 (CSF1R), é um receptor de um factor de crescimento hematopoiético que é especificamente expresso em células do sistema fagocítico-mononuclear e desempenha um papel essencial no desenvolvimento e regulação destas células. O CSF1R já foi descrito em vários mamíferos e a sua biologia tem sido exaustivamente caracterizada nestes vertebrados mas o conheci...

  5. Multistep change in epidermal growth factor receptors during spontaneous neoplastic progression in Chinese hamster embryo fibroblasts

    International Nuclear Information System (INIS)

    Wakshull, E.; Kraemer, P.M.; Wharton, W.

    1985-01-01

    Whole Chinese hamster embryo lineages have been shown to undergo multistep spontaneous neoplastic progression during serial passage in culture. The authors have studied the binding, internalization, and degradation of 125 I-labeled epidermal growth factor at four different stages of transformation. The whole Chinese hamster embryo cells lost cell surface epidermal growth factor receptors gradually during the course of neoplastic progression until only 10% of the receptor number present in the early-passage cells (precrisis) were retained in the late-passage cells (tumorigenic). No differences in internalization rates, chloroquine sensitivity, or ability to degrade hormone between the various passage levels were seen. No evidence for the presence in conditioned medium of transforming growth factors which might mask or down-regulate epidermal growth factor receptor was obtained. These results suggest that a reduction in cell surface epidermal growth factor receptor might be an early event during spontaneous transformation in whole Chinese hamster embryo cells

  6. Targeting of TAM Receptors Ameliorates Fibrotic Mechanisms in Idiopathic Pulmonary Fibrosis.

    Science.gov (United States)

    Espindola, Milena S; Habiel, David M; Narayanan, Rohan; Jones, Isabelle; Coelho, Ana L; Murray, Lynne A; Jiang, Dianhua; Noble, Paul W; Hogaboam, Cory M

    2018-06-01

    Idiopathic pulmonary fibrosis (IPF) is characterized by aberrant lung remodeling, which progressively abolishes lung function in an RTK (receptor tyrosine kinase)-dependent manner. Gas6 (growth arrest-specific 6) ligand, Tyro3 (TYRO3 protein tyrosine kinase 3), and Axl (anexelekto) RTK expression and activity are increased in IPF. To determine if targeting these RTK pathways would inhibit fibroblast activation and the development of pulmonary fibrosis. Quantitative genomic, proteomic, and functional analyses were used to determine Gas6/TAM (Tyro3, Axl, and Mertk [MER proto-oncogene, tyrosine kinase]) RTK expression and activation in tissues and fibroblasts from normal and IPF lungs. The profibrotic impact of these RTK pathways were also examined in bleomycin-induced pulmonary fibrosis and in SCID/Bg mice that developed pulmonary fibrosis after the intravenous administration of primary IPF fibroblasts. Gas6, Axl, and Tyro3 were increased in both rapidly and slowly progressive IPF compared with normal lung samples and fibroblasts. Targeting these pathways with either specific antibodies directed at Gas6 or Axl, or with small-molecule TAM inhibitors indicated that the small molecule-mediated targeting approach was more efficacious in both in vitro and in vivo studies. Specifically, the TAM receptor inhibitor R428 (also known as BGB324) significantly inhibited the synthetic, migratory, and proliferative properties of IPF fibroblasts compared with the other Gas6/TAM receptor targeting agents. Finally, loss of Gas6 expression decreased lung fibrotic responses to bleomycin and treatment with R428 inhibited pulmonary fibrosis in humanized SCID/Bg mice. Gas6/TAM receptor activity contributes to the activation of pulmonary fibroblasts in IPF, suggesting that targeting this RTK pathway might be an effective antifibrotic strategy in this disease.

  7. Hierarchical classification strategy for Phenotype extraction from epidermal growth factor receptor endocytosis screening

    NARCIS (Netherlands)

    L. Cao (Lu); M. Graauw (Marjo de); K. Yan (Kuan); L.C.J. Winkel (Leah C.J.); F.J. Verbeek (Fons)

    2016-01-01

    textabstractBackground: Endocytosis is regarded as a mechanism of attenuating the epidermal growth factor receptor (EGFR) signaling and of receptor degradation. There is increasing evidence becoming available showing that breast cancer progression is associated with a defect in EGFR endocytosis. In

  8. Targeting of the tumor necrosis factor receptor superfamily for cancer immunotherapy

    NARCIS (Netherlands)

    Bremer, Edwin

    2013-01-01

    The tumor necrosis factor (TNF) ligand and cognate TNF receptor superfamilies constitute an important regulatory axis that is pivotal for immune homeostasis and correct execution of immune responses. TNF ligands and receptors are involved in diverse biological processes ranging from the selective

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

    International Nuclear Information System (INIS)

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

    2010-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Kellermeier Silvia

    2010-06-01

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

  11. Sulindac metabolites inhibit epidermal growth factor receptor activation and expression

    Directory of Open Access Journals (Sweden)

    Ahnen Dennis

    2005-01-01

    Full Text Available Abstract Background Regular use of nonsteroidal anti-inflammatory drugs (NSAIDs is associated with a decreased mortality from colorectal cancer (CRC. NSAIDs induce apoptotic cell death in colon cancer cells in vitro and inhibit growth of neoplastic colonic mucosa in vivo however, the biochemical mechanisms required for these growth inhibitory effects are not well defined. We previously reported that metabolites of the NSAID sulindac downregulate extracellular-signal regulated kinase 1/2 (ERK1/2 signaling and that this effect is both necessary and sufficient for the apoptotic effects of these drugs. The goal of this project was to specifically test the hypothesis that sulindac metabolites block activation and/or expression of the epidermal growth factor (EGF receptor (EGFR. Methods HT29 human colon cancer cells were treated with EGF, alone, or in the presence of sulindac sulfide or sulindac sulfone. Cells lysates were assayed by immunoblotting for phosphorylated EGFR (pEGFR, pY1068, total EGFR, phosphorylated ERK1/2 (pERK1/2, total ERK1/2, activated caspase-3, and α-tubulin. Results EGF treatment rapidly induced phosphorylation of both EGFR and ERK1/2 in HT29 colon cancer cells. Pretreatment with sulindac metabolites for 24 h blocked EGF-induced phosphorylation of both EGFR and ERK1/2 and decreased total EGFR protein expression. Under basal conditions, downregulation of pEGFR and total EGFR was detected as early as 12 h following sulindac sulfide treatment and persisted through at least 48 h. Sulindac sulfone induced downregulation of pEGFR and total EGFR was detected as early as 1 h and 24 h, respectively, following drug treatment, and persisted through at least 72 h. EGFR downregulation by sulindac metabolites was observed in three different CRC cell lines, occurred prior to the observed downregulation of pERK1/2 and induction of apoptosis by these drugs, and was not dependent of caspase activation. Conclusion These results suggest that

  12. Regulation of insulin-like growth factor I receptors on vascular smooth muscle cells by growth factors and phorbol esters.

    Science.gov (United States)

    Ververis, J J; Ku, L; Delafontaine, P

    1993-06-01

    Insulin-like growth factor I (IGF I) is an important mitogen for vascular smooth muscle cells. To characterize regulation of vascular IGF I receptors, we performed radioligand displacement experiments using rat aortic smooth muscle cells (RASMs). Serum deprivation for 48 hours caused a 40% decrease in IGF I receptor number. Exposure of quiescent RASMs to platelet-derived growth factor (PDGF), fibroblast growth factor (FGF), or angiotensin II (Ang II) caused a 1.5-2.0-fold increase in IGF I receptors per cell. After FGF exposure, there was a marked increase in the mitogenic response to IGF I. IGF I downregulated its receptors in the presence of platelet-poor plasma. Stimulation of protein kinase C (PKC) by exposure of quiescent RASMs to phorbol 12-myristate 13-acetate caused a biphasic response in IGF I binding; there was a 42% decrease in receptor number at 45 minutes and a 238% increase at 24 hours. To determine the role of PKC in growth factor-induced regulation of IGF I receptors, we downregulated PKC by exposing RASMs to phorbol 12,13-dibutyrate (PDBu) for 48 hours. PDGF- and FGF- but not Ang II-mediated upregulation of IGF I receptors was completely inhibited in PDBu-treated cells. Thus, acute PKC activation by phorbol esters inhibits IGF I binding, whereas chronic PKC activation increases IGF I binding. PDGF and FGF but not Ang II regulate vascular IGF I receptors through a PKC-dependent pathway. These data provide new insights into the regulation of vascular smooth muscle cell IGF I receptors in vitro and are of potential importance in characterizing vascular proliferative responses in vivo.

  13. EphA2 is a functional receptor for the growth factor progranulin.

    Science.gov (United States)

    Neill, Thomas; Buraschi, Simone; Goyal, Atul; Sharpe, Catherine; Natkanski, Elizabeth; Schaefer, Liliana; Morrione, Andrea; Iozzo, Renato V

    2016-12-05

    Although the growth factor progranulin was discovered more than two decades ago, the functional receptor remains elusive. Here, we discovered that EphA2, a member of the large family of Ephrin receptor tyrosine kinases, is a functional signaling receptor for progranulin. Recombinant progranulin bound with high affinity to EphA2 in both solid phase and solution. Interaction of progranulin with EphA2 caused prolonged activation of the receptor, downstream stimulation of mitogen-activated protein kinase and Akt, and promotion of capillary morphogenesis. Furthermore, we found an autoregulatory mechanism of progranulin whereby a feed-forward loop occurred in an EphA2-dependent manner that was independent of the endocytic receptor sortilin. The discovery of a functional signaling receptor for progranulin offers a new avenue for understanding the underlying mode of action of progranulin in cancer progression, tumor angiogenesis, and perhaps neurodegenerative diseases. © 2016 Neill et al.

  14. Signal transduction by growth factor receptors: signaling in an instant

    DEFF Research Database (Denmark)

    Dengjel, Joern; Akimov, Vyacheslav; Blagoev, Blagoy

    2007-01-01

    Phosphorylation-based signaling events happening within the first minute of receptor stimulation have so far only been analyzed by classical cell biological approaches like live-cell microscopy. The development of a quench flow system with a time resolution of one second coupled to a read...

  15. Tumor necrosis factor receptor- associated factor 6 (TRAF6) regulation of development, function, and homeostasis of the immune system.

    Science.gov (United States)

    Walsh, Matthew C; Lee, JangEun; Choi, Yongwon

    2015-07-01

    Tumor necrosis factor receptor (TNFR)-associated factor 6 (TRAF6) is an adapter protein that mediates a wide array of protein-protein interactions via its TRAF domain and a RING finger domain that possesses non-conventional E3 ubiquitin ligase activity. First identified nearly two decades ago as a mediator of interleukin-1 receptor (IL-1R)-mediated activation of NFκB, TRAF6 has since been identified as an actor downstream of multiple receptor families with immunoregulatory functions, including members of the TNFR superfamily, the Toll-like receptor (TLR) family, tumor growth factorreceptors (TGFβR), and T-cell receptor (TCR). In addition to NFκB, TRAF6 may also direct activation of mitogen-activated protein kinase (MAPK), phosphoinositide 3-kinase (PI3K), and interferon regulatory factor pathways. In the context of the immune system, TRAF6-mediated signals have proven critical for the development, homeostasis, and/or activation of B cells, T cells, and myeloid cells, including macrophages, dendritic cells, and osteoclasts, as well as for organogenesis of thymic and secondary lymphoid tissues. In multiple cellular contexts, TRAF6 function is essential not only for proper activation of the immune system but also for maintaining immune tolerance, and more recent work has begun to identify mechanisms of contextual specificity for TRAF6, involving both regulatory protein interactions, and messenger RNA regulation by microRNAs. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  16. Tumor necrosis factor receptor associated factor 6 (TRAF6) regulation of development, function, and homeostasis of the immune system

    Science.gov (United States)

    Walsh, Matthew C.; Lee, JangEun; Choi, Yongwon

    2016-01-01

    Summary Tumor necrosis factor receptor (TNFR)-associated factor 6 (TRAF6) is an adaptor protein that mediates a wide array of protein-protein interactions via its TRAF domain and a RING finger domain that possesses non-conventional E3 ubiquitin ligase activity. First identified nearly two decades ago as a mediator of IL-1 receptor (IL-1R)-mediated activation of NFκB, TRAF6 has since been identified as an actor downstream of multiple receptor families with immunoregulatory functions, including members of the TNFR superfamily, the toll-like receptor (TLR) family, tumor growth factorreceptors (TGFβR), and T cell receptor (TCR). In addition to NFκB, TRAF6 may also direct activation of mitogen-activated protein kinase (MAPK), phosphoinositide 3-kinase (PI3K), and interferon regulatory factor (IRF) pathways. In the context of the immune system, TRAF6-mediated signals have proven critical for the development, homeostasis, and/or activation of B cells, T cells, and myeloid cells, including macrophages, dendritic cells, and osteoclasts, as well as for organogenesis of thymic and secondary lymphoid tissues. In multiple cellular contexts, TRAF6 function is essential not only for proper activation of the immune system, but also for maintaining immune tolerance, and more recent works have begun to identify mechanisms of contextual specificity for TRAF6, involving both regulatory protein interactions, and messenger RNA regulation by microRNAs. PMID:26085208

  17. SH2 domains of the p85 alpha subunit of phosphatidylinositol 3-kinase regulate binding to growth factor receptors.

    Science.gov (United States)

    McGlade, C J; Ellis, C; Reedijk, M; Anderson, D; Mbamalu, G; Reith, A D; Panayotou, G; End, P; Bernstein, A; Kazlauskas, A

    1992-01-01

    The binding of cytoplasmic signaling proteins such as phospholipase C-gamma 1 and Ras GTPase-activating protein to autophosphorylated growth factor receptors is directed by their noncatalytic Src homology region 2 (SH2) domains. The p85 alpha regulatory subunit of phosphatidylinositol (PI) 3-kinase, which associates with several receptor protein-tyrosine kinases, also contains two SH2 domains. Both p85 alpha SH2 domains, when expressed individually as fusion proteins in bacteria, bound stably to the activated beta receptor for platelet-derived growth factor (PDGF). Complex formation required PDGF stimulation and was dependent on receptor tyrosine kinase activity. The bacterial p85 alpha SH2 domains recognized activated beta PDGF receptor which had been immobilized on a filter, indicating that SH2 domains contact autophosphorylated receptors directly. Several receptor tyrosine kinases within the PDGF receptor subfamily, including the colony-stimulating factor 1 receptor and the Steel factor receptor (Kit), also associate with PI 3-kinase in vivo. Bacterially expressed SH2 domains derived from the p85 alpha subunit of PI 3-kinase bound in vitro to the activated colony-stimulating factor 1 receptor and to Kit. We infer that the SH2 domains of p85 alpha bind to high-affinity sites on these receptors, whose creation is dependent on receptor autophosphorylation. The SH2 domains of p85 are therefore primarily responsible for the binding of PI 3-kinase to activated growth factor receptors. Images PMID:1372092

  18. Convergence and divergence of tumor-suppressor and proto-oncogenes in chimpanzee from human chromosome 17

    Energy Technology Data Exchange (ETDEWEB)

    Verma, R.S.; Ramesh, K.H. [Long Island College Hospital, Brooklyn, NY (United States)

    1994-09-01

    Due to the emergence of molecular technology, the phylogenetic evolution of the human genome via apes has become a saltatory even. In the present investigation, cosmid probes for P53, Charcot-Marie-Tooth [CMTIA], HER-2/NEU and myeloperoxidase [MPO] were used. Probes mapping to these genetic loci are well-defined on human chromosome 17 [HSA 17]. We localized these genes on chimpanzee [Pan troglodyte] chromosomes by FISH technique employing two different cell lines. Our results indicate that chimpanzee chromosome 19 [PTR 19] differs from HSA 17 by a pericentric inversion. The P53 gene assigned to HSA 17p13.1 is localized on PTR 19p15 and the MPO sequence of HSA 17q21.3-23 hybridized to PTR 19q23. Perplexing enough, HER-2/NEU assigned to HSA 17q11.2 localized to PTR 19p12. Obviously, there is convergence of P53 and MPO regions and distinctive divergence of HER-2/NEU and CMT1A regions of human and chimpanzee. This investigation has demonstrated the pronounced genetic shuffling which occurred during the origin of HSA 17. Molecular markers should serve as evolutionary punctuations in defining the precise sequence of genetic events that led to the evolution of other chromosomes whose genomic synteny, although similar, have surprisingly evolved through different mechanisms.

  19. Analysis of nucleo-cytoplasmic shuttling of the proto-oncogene SET/I2PP2A

    NARCIS (Netherlands)

    Lam, B. Daniel; Anthony, Eloise C.; Hordijk, Peter L.

    2012-01-01

    SET/I2PP2A is a nuclear protein that was initially identified as an oncogene in human undifferentiated acute myeloid leukemia, fused to the nuclear porin Nup-214. In addition, SET is a potent inhibitior of the phosphatase PP2A. Previously, we proposed a model in which the small GTPase Rac1 recruits

  20. The proto-oncogene KRAS and BRAF profiles and some clinical characteristics in colorectal cancer in the Turkish population.

    Science.gov (United States)

    Ozen, Filiz; Ozdemir, Semra; Zemheri, Ebru; Hacimuto, Gizem; Silan, Fatma; Ozdemir, Ozturk

    2013-02-01

    The aim of the current study was to investigate the prevalence and predictive significance of the KRAS and BRAF mutations in Turkish patients with colorectal cancer (CRC). Totally, 53 fresh tumoral tissue specimens were investigated in patients with CRC. All specimens were obtained during routine surgery of patients who were histopathologically diagnosed and genotyped for common KRAS and BRAF point mutations. After DNA extraction, the target mutations were analyzed using the AutoGenomics INFINITI(®) assay, and some samples were confirmed by quantitative real-time polymerase chain reaction fluorescence melting curve analyses. KRAS mutations were found in 26 (49.05%) CRC samples. Twenty-seven samples (50.95%) had wild-type profiles for KRAS codon 12, 13, and 61 in the current cohort. In 17 (65.38%) samples, codon 12; in 7 (26.93%) samples, codon 13; and in 2 (7.69%) samples, codon 61 were found to be mutated, particularly in grade 2 of tumoral tissues. No point mutation was detected in BRAF codon Val600Glu for the studied CRC patients. Our study, based on a representative collection of human CRC tumors, indicates that KRAS gene mutations were detected in 49.05% of the samples, and the most frequent mutation was in the G12D codon. Results also showed that codons 12 and 13 of KRAS are relatively frequently without BRAF mutation in a CRC cohort from the Turkish population.

  1. Increase of tumor necrosis factor receptor 1 expression in women with unexplained early spontaneous abortion

    Institute of Scientific and Technical Information of China (English)

    YAN Chun-fang; YU Xue-wen; JIN Hui; LI Xu

    2004-01-01

    To investigate membrane tumor necrosis factor receptor 1 protein expression level in decidua andconcentration of soluble tumor necrosis factor receptor 1 in serum in women with unexplained early spontaneous abortion,threatened abortion, and compare the levels with healthy pregnant women. Methods: Thirty-seven women with unexplainedearly spontaneous abortion, 27 women with threatened abortion, and 34 healthy pregnant women undergoing artificial abortionof pregnancy at 6 - 10 weeks of gestation were selected. Decidual samples were collected when women were undergoing arti-ficial abortion, and blood samples were collected at the same time. The level of membrane tumor necrosis factor receptor 1 indecidua was detected by flow cytometer, and the concentration of soluble tumor necrosis factor receptor 1 in sera was mea-sured with an enzyme-linked immunosorbent assay. Results: The ercentages of membrane tumor necrosis factor receptor 1positive decidual cells were 16.42 ± 7.10 Mean ± SD for women with unexplained early spontaneous abortion and 13.14 ±6.30 for healthy pregnant women ( P < 0.05). Serum oncentration of soluble tumor necrosis factor receptor 1 was signifi-cantly higher in women with unexplained early spontaneous abortion than in healthy pregnant women and in women withthreatened abortion, and no difference was found between healthy pregnant women and women with threatened abortion.Conclusion: Women with unexplained early spontaneous abortion present significantly higher expression of tumor necrosisfactor receptor 1 than healthy pregnant women, suggesting that over-expression of tumor necrosis factor receptor 1 may cont-ribute to the development of early spontaneous abortion.

  2. Immunoautoradiographic analysis of epidermal growth factor receptors: a sensitive method for the in situ identification of receptor proteins and for studying receptor specificity

    International Nuclear Information System (INIS)

    Fernandez-Pol, J.A.

    1982-01-01

    The use of an immunoautoradiographic system for the detection and analysis of epidermal growth factor (EGF) receptors in human epidermoid carcinoma A-431 cells is reported. By utilizing this technique, the interaction between EGF and its membrane receptor in A-431 cells can be rapidly visualized. The procedure is simple, rapid, and very sensitive, and it provides conclusive evidence that the 150K dalton protein is the receptor fo EGF in A-431 cells. In summary, the immunoautoradiographic procedure brings to the analysis of hormone rceptor proteins the power that the radioimmunoassay technique has brought to the analysis of hormones. Thus, this assay system is potentially applicable in a wide spectrum in many fields of nuclear medicine and biology

  3. Altered [125I]epidermal growth factor binding and receptor distribution in psoriasis

    International Nuclear Information System (INIS)

    Nanney, L.B.; Stoscheck, C.M.; Magid, M.; King, L.E. Jr.

    1986-01-01

    Stimulation of growth and differentiation of human epidermis by epidermal growth factor (EGF) is mediated by its binding to specific receptors. Whether EGF receptors primarily mediate cell division or differentiation in hyperproliferative disease such as psoriasis vulgaris is unclear. To study the pathogenesis of psoriasis, 4-mm2 punch biopsy specimens of normal, uninvolved, and involved psoriatic skin were assayed for EGF receptors by autoradiographic, immunohistochemical, and biochemical methods. Using autoradiographic and immunohistochemical methods, basal keratinocytes were found to contain the greatest number of EGF binding sites and immunoreactive receptors as compared to the upper layers of the epidermis in both normal epidermis and psoriatic skin. No EGF receptor differences between normal and psoriatic epidermis were observed in this layer. In the upper layers of the epidermis, a 2-fold increase in EGF binding capacity was observed in psoriatic skin as compared with normal thin or thick skin. Biochemical methods indicated that [ 125 I]EGF binding was increased in psoriatic epidermis as compared with similar thickness normal epidermis when measured on a protein basis. Epidermal growth factor was shown to increase phosphorylation of the EGF receptor in skin. EGF receptors retained in the nonmitotic stratum spinosum and parakeratotic stratum corneum may reflect the incomplete, abnormal differentiation that occurs in active psoriatic lesions. Alternatively, retained EGF receptors may play a direct role in inhibiting cellular differentiation in the suprabasal layers

  4. Hormonal receptors and vascular endothelial growth factor in juvenile nasopharyngeal angiofibroma: immunohistochemical and tissue microarray analysis.

    Science.gov (United States)

    Liu, Zhuofu; Wang, Jingjing; Wang, Huan; Wang, Dehui; Hu, Li; Liu, Quan; Sun, Xicai

    2015-01-01

    This work demonstrated that juvenile nasopharyngeal angiofibromas (JNAs) express high levels of hormone receptors and vascular endothelial growth factor (VEGF) compared with normal nasal mucosa. The interaction between hormone receptors and VEGF may be involved in the initiation and growth of JNA. JNA is a rare benign tumor that occurs almost exclusively in male adolescents. Although generally regarded as a hormone-dependent tumor, this has not been proven in previous studies. The aim of this study was to investigate the role of hormone receptors in JNA and the relationship with clinical characteristics. Standard immunohistochemical microarray analysis was performed on 70 JNA samples and 10 turbinate tissue samples. Specific antibodies for androgen receptor (AR), estrogen receptor-α (ER-α), estrogen receptor-β (ER-β), progesterone receptor (PR), and VEGF were examined, and the relationships of receptor expression with age, tumor stage, and bleeding were evaluated. RESULTS showed that JNA expressed ER-α (92.9%), ER-β (91.4%), AR (65.7%), PR (12.8%), and VEGF (95.7%) at different levels. High level of VEGF was linked to elevated ER-α and ER-β. There was no significant relationship between hormonal receptors and age at diagnosis, tumor stage or bleeding. However, overexpression of ER-α was found to be an indicator of poor prognosis (p = 0.031).

  5. Insulin-like growth factor-II receptors in cultured rat hepatocytes: regulation by cell density

    International Nuclear Information System (INIS)

    Scott, C.D.; Baxter, R.C.

    1987-01-01

    Insulin-like growth factor-II (IGF-II) receptors in primary cultures of adult rat hepatocytes were characterized and their regulation by cell density examined. In hepatocytes cultured at 5 X 10(5) cells per 3.8 cm2 plate [ 125 I]IGF-II bound to specific, high affinity receptors (Ka = 4.4 +/- 0.5 X 10(9) l/mol). Less than 1% cross-reactivity by IGF-I and no cross-reactivity by insulin were observed. IGF-II binding increased when cells were permeabilized with 0.01% digitonin, suggesting the presence of an intracellular receptor pool. Determined by Scatchard analysis and by polyacrylamide gel electrophoresis after affinity labeling, the higher binding was due solely to an increase in binding sites present on 220 kDa type II IGF receptors. In hepatocytes cultured at low densities, the number of cell surface receptors increased markedly, from 10-20,000 receptors per cell at a culture density of 6 X 10(5) cells/well to 70-80,000 receptors per cell at 0.38 X 10(5) cells/well. The increase was not due simply to the exposure of receptors from the intracellular pool, as a density-related increase in receptors was also seen in cells permeabilized with digitonin. There was no evidence that IGF binding proteins, either secreted by hepatocytes or present in fetal calf serum, had any effect on the measurement of receptor concentration or affinity. We conclude that rat hepatocytes in primary culture contain specific IGF-II receptors and that both cell surface and intracellular receptors are regulated by cell density

  6. Molecular and functional characterization of pigeon (Columba livia) tumor necrosis factor receptor-associated factor 3.

    Science.gov (United States)

    Zhou, Yingying; Kang, Xilong; Xiong, Dan; Zhu, Shanshan; Zheng, Huijuan; Xu, Ying; Guo, Yaxin; Pan, Zhiming; Jiao, Xinan

    2017-04-01

    Tumor necrosis factor receptor-associated factor 3 (TRAF3) plays a key antiviral role by promoting type I interferon production. We cloned the pigeon TRAF3 gene (PiTRAF3) according to its predicted mRNA sequence to investigate its function. The 1704-bp full-length open reading frame encodes a 567-amino acid protein. One Ring finger, two TRAF-type Zinc fingers, one Coiled coil, and one MATH domain were inferred. RT-PCR showed that PiTRAF3 was expressed in all tissues, with relatively weak expression in the heart and liver. In HEK293T cells, over-expression of wild-type, △Ring, △Zinc finger, and △Coiled coil PiTRAF3, but not a △MATH form, significantly increased IFN-β promoter activity. Zinc finger and Coiled coil domains were essential for NF-κB activation. In chicken HD11 cells, PiTRAF3 increased IFN-β promoter activity and four domains were all contributing. R848 stimulation of pigeon peripheral blood mononuclear cells and splenocytes significantly increased expression of PiTRAF3 and the inflammatory cytokine genes CCL5, IL-8, and IL-10. These data demonstrate TRAF3's innate immune function and improve understanding of its involvement in poultry antiviral defense. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Distinct phosphotyrosines on a growth factor receptor bind to specific molecules that mediate different signaling pathways.

    Science.gov (United States)

    Fantl, W J; Escobedo, J A; Martin, G A; Turck, C W; del Rosario, M; McCormick, F; Williams, L T

    1992-05-01

    The receptor for platelet-derived growth factor (PDGF) binds two proteins containing SH2 domains, GTPase activating protein (GAP) and phosphatidylinositol 3-kinase (PI3-kinase). The sites on the receptor that mediate this interaction were identified by using phosphotyrosine-containing peptides representing receptor sequences to block specifically binding of either PI3-kinase or GAP. These results suggested that PI3-kinase binds two phosphotyrosine residues, each located in a 5 aa motif with an essential methionine at the fourth position C-terminal to the tyrosine. Point mutations at these sites caused a selective elimination of PI3-kinase binding and loss of PDGF-stimulated DNA synthesis. Mutation of the binding site for GAP prevented the receptor from associating with or phosphorylating GAP, but had no effect on PI3-kinase binding and little effect on DNA synthesis. Therefore, GAP and PI3-kinase interact with the receptor by binding to different phosphotyrosine-containing sequence motifs.

  8. Internalization mechanisms of the epidermal growth factor receptor after activation with different ligands.

    Directory of Open Access Journals (Sweden)

    Lasse Henriksen

    Full Text Available The epidermal growth factor receptor (EGFR regulates normal growth and differentiation, but dysregulation of the receptor or one of the EGFR ligands is involved in the pathogenesis of many cancers. There are eight ligands for EGFR, however most of the research into trafficking of the receptor after ligand activation focuses on the effect of epidermal growth factor (EGF and transforming growth factor-α (TGF-α. For a long time it was believed that clathrin-mediated endocytosis was the major pathway for internalization of the receptor, but recent work suggests that different pathways exist. Here we show that clathrin ablation completely inhibits internalization of EGF- and TGF-α-stimulated receptor, however the inhibition of receptor internalization in cells treated with heparin-binding EGF-like growth factor (HB-EGF or betacellulin (BTC was only partial. In contrast, clathrin knockdown fully inhibits EGFR degradation after all ligands tested. Furthermore, inhibition of dynamin function blocked EGFR internalization after stimulation with all ligands. Knocking out a number of clathrin-independent dynamin-dependent pathways of internalization had no effect on the ligand-induced endocytosis of the EGFR. We suggest that EGF and TGF-α lead to EGFR endocytosis mainly via the clathrin-mediated pathway. Furthermore, we suggest that HB-EGF and BTC also lead to EGFR endocytosis via a clathrin-mediated pathway, but can additionally use an unidentified internalization pathway or better recruit the small amount of clathrin remaining after clathrin knockdown.

  9. Internalization Mechanisms of the Epidermal Growth Factor Receptor after Activation with Different Ligands

    Science.gov (United States)

    Henriksen, Lasse; Grandal, Michael Vibo; Knudsen, Stine Louise Jeppe; van Deurs, Bo; Grøvdal, Lene Melsæther

    2013-01-01

    The epidermal growth factor receptor (EGFR) regulates normal growth and differentiation, but dysregulation of the receptor or one of the EGFR ligands is involved in the pathogenesis of many cancers. There are eight ligands for EGFR, however most of the research into trafficking of the receptor after ligand activation focuses on the effect of epidermal growth factor (EGF) and transforming growth factor-α (TGF-α). For a long time it was believed that clathrin-mediated endocytosis was the major pathway for internalization of the receptor, but recent work suggests that different pathways exist. Here we show that clathrin ablation completely inhibits internalization of EGF- and TGF-α-stimulated receptor, however the inhibition of receptor internalization in cells treated with heparin-binding EGF-like growth factor (HB-EGF) or betacellulin (BTC) was only partial. In contrast, clathrin knockdown fully inhibits EGFR degradation after all ligands tested. Furthermore, inhibition of dynamin function blocked EGFR internalization after stimulation with all ligands. Knocking out a number of clathrin-independent dynamin-dependent pathways of internalization had no effect on the ligand-induced endocytosis of the EGFR. We suggest that EGF and TGF-α lead to EGFR endocytosis mainly via the clathrin-mediated pathway. Furthermore, we suggest that HB-EGF and BTC also lead to EGFR endocytosis via a clathrin-mediated pathway, but can additionally use an unidentified internalization pathway or better recruit the small amount of clathrin remaining after clathrin knockdown. PMID:23472148

  10. Growth factor receptors as molecular targets for cancer diagnosis and therapy

    International Nuclear Information System (INIS)

    Zalutsky, M. R.

    1997-01-01

    Growth factor receptors are of great interest as molecular targets for the diagnosis and treatment of cancer. Growth factor receptors are frequently over expressed on malignant cell populations since many cellular oncogenes encode either growth factors of their receptors. The wild-type epidermal growth factor receptor has a molecular weight of 170 kD and is over expressed on gliomas, bladder tumors, squamous cells carcinomas and breast carcinomas. Another growth factor oncogene, c-erb B-2, encodes a 185-kD glycoprotein found on the surface of gliomas, breast and ovarian cancers as well as other carcinomas of epithelial origin. In addition to causing over expression, oncogenic transformation also can result in genomic re-arrangements. An important example from the perspective of targeting is EGFRvIII, a deletion mutant which lacks amino acids 6-273 in the extracellular domain of the epiderma growth factor receptor. The EGFRvIII molecule (145 kD) may be of great value for targeting because it appears to be tumor-specific. Antibodies have been developed with specific reactivity with these growth factor receptors. Since these antibodies are internalized into the cell after receptor binding, it is necessary to use radiolabeling methods which residualize the radioactivity in the tumor cell after intracellular catabolism. To investigate this problem they have evaluated the effect of radioiodination method on the in vitro an in vivo properties of an anti-EGFRvIII antibody. Methods studied were Iodogen, tyramine-cellobiose, and N-succinimidyl 5-iodo-3-pyridine-carboxylate with the last offering optimal localization in a human xenograft model

  11. Epidermal growth factor receptor: an independent predictor of survival in astrocytic tumors given definitive irradiation

    International Nuclear Information System (INIS)

    An Zhu; Shaeffer, James; Leslie, Susan; Kolm, Paul; El-Mahdi, Anas M.

    1996-01-01

    Purpose: To determine whether the expression of epidermal growth factor receptor (EGFR) protein was predictive of patient survival independently of other prognostic factors in astrocytic tumors. Methods and Materials: Epidermal growth factor receptor protein expression was investigated immunohistochemically in formalin-fixed, paraffin-embedded surgical specimens of 55 glioblastoma multiforme, 14 anaplastic astrocytoma, and 2 astrocytomas given definitive irradiation. We evaluated the relationship of EGFR protein expression and tumor grade, histologic features, age at diagnosis, sex, patient survival, and recurrence-free survival. Results: The percentage of tumor cells which were EGFR positive related to reduced survival by Cox regression analysis in both univariate (p = 0.0424) and multivariate analysis (p = 0.0016). Epidermal growth factor receptor positivity was the only 1 of 11 clinical and histological variables associated with decreased recurrence-free survival by either univariate (p = 0.0353) or multivariate (p = 0.0182) analysis. Epidermal growth factor receptor protein expression was not related to patient age, sex, or histologic features. Conclusion: Epidermal growth factor receptor positivity was a significant and independent prognostic indicator for overall survival and recurrence-free survival for irradiated patients with astrocytic gliomas

  12. Inhibition of the release of soluble tumor necrosis factor receptors in experimental endotoxemia by an anti-tumor necrosis factor-alpha antibody

    NARCIS (Netherlands)

    Jansen, J.; van der Poll, T.; Levi, M. [=Marcel M.; ten Cate, H.; Gallati, H.; ten Cate, J. W.; van Deventer, S. J.

    1995-01-01

    The role of tumor necrosis factor-alpha in the shedding of soluble tumor necrosis factor receptors in endotoxemia was investigated. The appearance of the soluble tumor necrosis factor receptors was assessed in four healthy volunteers following an intravenous injection of tumor necrosis factor-alpha

  13. Embryonic expression of the transforming growth factor beta ligand and receptor genes in chicken.

    Science.gov (United States)

    Cooley, James R; Yatskievych, Tatiana A; Antin, Parker B

    2014-03-01

    Transforming growth factor-beta (TGFβ) signaling regulates a myriad of biological processes during embryogenesis, in the adult, and during the manifestation of disease. TGFβ signaling is propagated through one of three TGFβ ligands interacting with Type I and Type II receptors, and Type III co-receptors. Although TGFβ signaling is regulated partly by the combinatorial expression patterns of TGFβ receptors and ligands, a comprehensive gene expression analysis has not been published. Here we report the embryonic mRNA expression patterns in chicken embryos of the canonical TGFβ ligands (TGFB1, TGFB2, and TGFB3) and receptors (TGFBR1, TGFBR2, TGFBR3), plus the Activin A receptor, type 1 (ACVR1) and co receptor Endoglin (ENG) that also transduce TGFβ signaling. TGFB ligands and receptors show dynamic and frequently overlapping expression patterns in numerous embryonic cell layers and structures. Integrating expression information identifies combinations of ligands and receptors that are involved in specific developmental processes including somitogenesis, cardiogenesis and vasculogenesis. Copyright © 2013 Wiley Periodicals, Inc.

  14. ATAR, a novel tumor necrosis factor receptor family member, signals through TRAF2 and TRAF5.

    Science.gov (United States)

    Hsu, H; Solovyev, I; Colombero, A; Elliott, R; Kelley, M; Boyle, W J

    1997-05-23

    Members of tumor necrosis factor receptor (TNFR) family signal largely through interactions with death domain proteins and TRAF proteins. Here we report the identification of a novel TNFR family member ATAR. Human and mouse ATAR contain 283 and 276 amino acids, respectively, making them the shortest known members of the TNFR superfamily. The receptor is expressed mainly in spleen, thymus, bone marrow, lung, and small intestine. The intracellular domains of human and mouse ATAR share only 25% identity, yet both interact with TRAF5 and TRAF2. This TRAF interaction domain resides at the C-terminal 20 amino acids. Like most other TRAF-interacting receptors, overexpression of ATAR activates the transcription factor NF-kappaB. Co-expression of ATAR with TRAF5, but not TRAF2, results in synergistic activation of NF-kappaB, suggesting potentially different roles for TRAF2 and TRAF5 in post-receptor signaling.

  15. The development of epidermal growth factor receptor molecular imaging in cancer

    International Nuclear Information System (INIS)

    Zhou Xiaoliang; Wang Hao; Shi Peiji; Liu Jianfeng; Meng Aimin

    2013-01-01

    In vivo epidermal growth factor receptor (EGFR) targeted therapy has great potential for cancer diagnosis and the evaluation of curative effects. Enhancement of EGFR-targeted therapy needs a reliable quantitative molecular imaging method which could enable monitoring of receptor drug binding and receptor occupancy in vivo, and identification of the mutation in EGFR. PET or SPECT is the most advanced molecular imaging technology of non-invasively selecting responders, predicting therapeutic outcome and monitoring EGFR-targeted treatment. This review analyzed the present situation and research progress of molecular imaging agents. (authors)

  16. Functional and structural stability of the epidermal growth factor receptor in detergent micelles and phospholipid nanodiscs

    DEFF Research Database (Denmark)

    Mi, Li-Zhi; Grey, Michael J; Nishida, Noritaka

    2008-01-01

    Cellular signaling mediated by the epidermal growth factor receptor (EGFR or ErbB) family of receptor tyrosine kinases plays an important role in regulating normal and oncogenic cellular physiology. While structures of isolated EGFR extracellular domains and intracellular protein tyrosine kinase...... differential functional stability in Triton X-100 versus dodecyl maltoside. Furthermore, the kinase activity can be significantly stabilized by reconstituting purified EGF-bound EGFR dimers in phospholipid nanodiscs or vesicles, suggesting that the environment around the hydrophobic transmembrane...

  17. Expression of platelet-derived growth factor and its receptors in proliferative disorders of fibroblastic origin.

    OpenAIRE

    Smits, A.; Funa, K.; Vassbotn, F. S.; Beausang-Linder, M.; af Ekenstam, F.; Heldin, C. H.; Westermark, B.; Nistér, M.

    1992-01-01

    Platelet-derived growth factor (PDGF) is known to stimulate the proliferation of connective tissue-derived cells in vitro. Less is known about its functions in vivo, and the role of PDGF in the development of human tumors has not been clarified. The authors have investigated the occurrence of PDGF and PDGF receptors in a series of proliferative disorders of fibroblastic origin using immunohistochemical and in situ hybridization techniques. High expression of PDGF beta-receptor mRNA and protei...

  18. A receptor model for urban aerosols based on oblique factor analysis

    DEFF Research Database (Denmark)

    Keiding, Kristian; Sørensen, Morten S.; Pind, Niels

    1987-01-01

    A procedure is outlined for the construction of receptor models of urban aerosols, based on factor analysis. The advantage of the procedure is that the covariation of source impacts is included in the construction of the models. The results are compared with results obtained by other receptor......-modelling procedures. It was found that procedures based on correlating sources were physically sound as well as in mutual agreement. Procedures based on non-correlating sources were found to generate physically obscure models....

  19. Targeting the epidermal growth factor receptor in solid tumor malignancies

    DEFF Research Database (Denmark)

    Nedergaard, Mette K; Hedegaard, Chris J; Poulsen, Hans S

    2012-01-01

    been proposed as valid targets in many cancer therapy settings. Different strategies have been developed in order to either inhibit EGFR/EGFRvIII activity or to ablate EGFR/EGFRvIII-positive tumor cells. Drugs that inhibit these receptors include monoclonal antibodies (mAbs) that bind...... to the extracellular part of EGFR, blocking the binding sites for the EGFR ligands, and intracellular tyrosine kinase inhibitors (TKIs) that block the ATP binding site of the tyrosine kinase domain. Besides an EGFRvIII-targeted vaccine, conjugated anti-EGFR mAbs have been used in different settings to deliver lethal...... agents to the EGFR/EGFRvIII-positive cells; among these are radio-labelled mAbs and immunotoxins. This article reviews the current status and efficacy of EGFR/EGFRvIII-targeted therapies....

  20. Aberrant status and clinicopathologic characteristic associations of 11 target genes in 1,321 Chinese patients with lung adenocarcinoma.

    Science.gov (United States)

    Zhao, Mengnan; Zhan, Cheng; Li, Ming; Yang, Xiaodong; Yang, Xinyu; Zhang, Yong; Lin, Miao; Xia, Yifeng; Feng, Mingxiang; Wang, Qun

    2018-01-01

    The aberrant status of target genes and their associations with clinicopathologic characteristics are still unclear in primary lung adenocarcinoma. The common mutations and translocations of nine target genes were evaluated in 1,247 specimens of surgically-resected primary lung adenocarcinoma. Immunohistochemistry was used to analyze the expressions of programmed death-1 (PD-1)/programmed death-ligand 1 (PD-L1) in 731 specimens. The frequency of the aberrations and their associations with clinicopathologic characteristics were analyzed. Overall, 952 (76.3%) of 1,247 patients harbored at least one target mutation or translocation: epidermal growth factor receptor ( EGFR ) (729, 58.5%), v-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog ( KRAS ) (83, 6.7%), human epidermal growth factor receptor 2 ( HER2 ) (82, 6.6%), anaplastic lymphoma kinase ( ALK) (23, 1.8%), phosphoinositide-3-kinase catalytic alpha polypeptide ( PIK3CA ) (20, 1.6%), Ret proto-oncogene RET (15, 1.2%), ROS proto-oncogene 1 receptor tyrosine kinase ( ROS1 ) (12, 1.0%), B-raf proto-oncogene ( BRAF ) (9, 0.7%), neuroblastoma RAS viral (v-ras) oncogene homolog ( NRAS ) (3, 0.2%). Fourteen (1.9%) of 731 patients were PD-1 positive and 95 (13.0%) were PD-L1 positive in tumor cells. In men and smokers, there were more frequent KRAS mutations (both Ppatients, while HER2 (Ppatients with EGFR mutations (all Ppatients with primary lung adenocarcinoma harbored target gene aberrations. The frequency of each alteration differed in patients depending on clinicopathologic characteristics.

  1. Mechanisms of integrin-vascular endothelial growth factor receptor cross-activation in angiogenesis.

    Science.gov (United States)

    Mahabeleshwar, Ganapati H; Feng, Weiyi; Reddy, Kumar; Plow, Edward F; Byzova, Tatiana V

    2007-09-14

    The functional responses of endothelial cells are dependent on signaling from peptide growth factors and the cellular adhesion receptors, integrins. These include cell adhesion, migration, and proliferation, which, in turn, are essential for more complex processes such as formation of the endothelial tube network during angiogenesis. This study identifies the molecular requirements for the cross-activation between beta3 integrin and tyrosine kinase receptor 2 for vascular endothelial growth factor (VEGF) receptor (VEGFR-2) on endothelium. The relationship between VEGFR-2 and beta3 integrin appears to be synergistic, because VEGFR-2 activation induces beta3 integrin tyrosine phosphorylation, which, in turn, is crucial for VEGF-induced tyrosine phosphorylation of VEGFR-2. We demonstrate here that adhesion- and growth factor-induced beta3 integrin tyrosine phosphorylation are directly mediated by c-Src. VEGF-stimulated recruitment and activation of c-Src and subsequent beta3 integrin tyrosine phosphorylation are critical for interaction between VEGFR-2 and beta3 integrin. Moreover, c-Src mediates growth factor-induced beta3 integrin activation, ligand binding, beta3 integrin-dependent cell adhesion, directional migration of endothelial cells, and initiation of angiogenic programming in endothelial cells. Thus, the present study determines the molecular mechanisms and consequences of the synergism between 2 cell surface receptor systems, growth factor receptor and integrins, and opens new avenues for the development of pro- and antiangiogenic strategies.

  2. Interactions between Type III receptor tyrosine phosphatases and growth factor receptor tyrosine kinases regulate tracheal tube formation in Drosophila

    Directory of Open Access Journals (Sweden)

    Mili Jeon

    2012-04-01

    The respiratory (tracheal system of the Drosophila melanogaster larva is an intricate branched network of air-filled tubes. Its developmental logic is similar in some ways to that of the vertebrate vascular system. We previously described a unique embryonic tracheal tubulogenesis phenotype caused by loss of both of the Type III receptor tyrosine phosphatases (RPTPs, Ptp4E and Ptp10D. In Ptp4E Ptp10D double mutants, the linear tubes in unicellular and terminal tracheal branches are converted into bubble-like cysts that incorporate apical cell surface markers. This tube geometry phenotype is modulated by changes in the activity or expression of the epidermal growth factor receptor (Egfr tyrosine kinase (TK. Ptp10D physically interacts with Egfr. Here we demonstrate that the Ptp4E Ptp10D phenotype is the consequence of the loss of negative regulation by the RPTPs of three growth factor receptor TKs: Egfr, Breathless and Pvr. Reducing the activity of any of the three kinases by tracheal expression of dominant-negative mutants suppresses cyst formation. By competing dominant-negative and constitutively active kinase mutants against each other, we show that the three RTKs have partially interchangeable activities, so that increasing the activity of one kinase can compensate for the effects of reducing the activity of another. This implies that SH2-domain downstream effectors that are required for the phenotype are likely to be able to interact with phosphotyrosine sites on all three receptor TKs. We also show that the phenotype involves increases in signaling through the MAP kinase and Rho GTPase pathways.

  3. Molecular Imaging and Precision Medicine in Head and Neck Cancer.

    Science.gov (United States)

    Mena, Esther; Thippsandra, Shwetha; Yanamadala, Anusha; Redy, Siddaling; Pattanayak, Puskar; Subramaniam, Rathan M

    2017-01-01

    The concept of using tumor genomic profiling information has revolutionized personalized cancer treatment. Head and neck (HN) cancer management is being influenced by recent discoveries of activating mutations in epidermal growth factor receptor and related targeted therapies with tyrosine kinase inhibitors, targeted therapies for Kristen Rat Sarcoma, and MET proto-oncogenes. Molecular imaging using PET plays an important role in assessing the biologic behavior of HN cancer with the goal of delivering individualized cancer treatment. This review summarizes recent genomic discoveries in HN cancer and their implications for functional PET imaging in assessing response to targeted therapies, and drug resistance mechanisms. Copyright © 2016 Elsevier Inc. All rights reserved.

  4. The aryl hydrocarbon receptor (AHR) transcription factor regulates megakaryocytic polyploidization.

    Science.gov (United States)

    Lindsey, Stephan; Papoutsakis, Eleftherios T

    2011-02-01

    We propose that the aryl hydrocarbon receptor (AHR) is a novel transcriptional regulator of megakaryopoietic polyploidization. Functional evidence was obtained that AHR impacts in vivo megakaryocytic differentiation and maturation; compared to wild-type mice, AHR-null mice had lower platelet counts, fewer numbers of newly synthesized platelets, increased bleeding times and lower-ploidy megakaryocytes (Mks). AHR mRNA increased 3·6-fold during ex vivo megakaryocytic differentiation, but reduced or remained constant during parallel isogenic granulocytic or erythroid differentiation. We interrogated the role of AHR in megakaryopoiesis using a validated Mk model of megakaryopoiesis, the human megakaryoblastic leukaemia CHRF cell line. Upon CHRF Mk differentiation, AHR mRNA and protein levels increased, AHR protein shifted from the cytoplasm to the nucleus and AHR binding to its consensus DNA binding sequence increased. Protein and mRNA levels of the AHR transcriptional target HES1 also increased. Mk differentiation of CHRF cells where AHR or HES1 was knocked-down using RNAi resulted in lower ploidy distributions and cells that were incapable of reaching ploidy classes ≥16n. AHR knockdown also resulted in increased DNA synthesis of lower ploidy cells, without impacting apoptosis. Together, these data support a role for AHR in Mk polyploidization and in vivo platelet function, and warrant further detailed investigations. © 2011 Blackwell Publishing Ltd.

  5. Internalization mechanisms of the epidermal growth factor receptor after activation with different ligands

    DEFF Research Database (Denmark)

    Henriksen, Lasse; Grandal, Michael Vibo; Knudsen, Stine Louise Jeppe

    2013-01-01

    after ligand activation focuses on the effect of epidermal growth factor (EGF) and transforming growth factor-α (TGF-α). For a long time it was believed that clathrin-mediated endocytosis was the major pathway for internalization of the receptor, but recent work suggests that different pathways exist....... Here we show that clathrin ablation completely inhibits internalization of EGF- and TGF-α-stimulated receptor, however the inhibition of receptor internalization in cells treated with heparin-binding EGF-like growth factor (HB-EGF) or betacellulin (BTC) was only partial. In contrast, clathrin knockdown...... fully inhibits EGFR degradation after all ligands tested. Furthermore, inhibition of dynamin function blocked EGFR internalization after stimulation with all ligands. Knocking out a number of clathrin-independent dynamin-dependent pathways of internalization had no effect on the ligand...

  6. Soluble tumor necrosis factor receptor-1 in preterm infants with chronic lung disease.

    Science.gov (United States)

    Sato, Miho; Mori, Masaaki; Nishimaki, Shigeru; An, Hiromi; Naruto, Takuya; Sugai, Toshiyuki; Shima, Yoshio; Seki, Kazuo; Yokota, Shumpei

    2010-04-01

    It is clear that inflammation plays an important role in developing chronic lung disease in preterm infants. The purpose of the present study is to investigate changes of serum soluble tumor necrosis factor receptor-1 levels over time in infants with chronic lung disease. The serum levels of soluble tumor necrosis factor receptor-1 were measured after delivery, and at 7, 14, 21 and 28 days of age in 10 infants with chronic lung disease and in 18 infants without chronic lung disease. The serum level of soluble tumor necrosis factor receptor-1 was significantly higher in infants with chronic lung disease than in infants without chronic lung disease after delivery. The differences between these two groups remained up to 28 days of age. Prenatal inflammation with persistence into postnatal inflammation may be involved in the onset of chronic lung disease.

  7. Identification of a second putative receptor of platelet activating factor on human polymorphonuclear leukocytes

    International Nuclear Information System (INIS)

    Hwang, S.B.

    1987-01-01

    Due to multiple molecular species of platelet activating factor (PAF) and the existence of high affinity binding sites in a variety of cells and tissues, possible existence of PAF receptor subtypes has been suggested. This report shows differences between specific PAF receptors on human leukocytes and platelets. Human PMN leukocyte membranes showed high affinity binding sites for PAF with an equilibrium dissociation constant (Kd) of 4.7 (+/- 1.4) x 10 -10 M. The maximal number (B/sub max/) of receptor sites was estimated to be 3.13 (+/- 1.4) x 10 -13 mol/mg protein. They compared the relative potencies of several PAF agonists and receptor antagonists between human platelet and human leukocyte membranes. One antagonist (Ono-6240) was found to be 8 times less potent at inhibiting the [ 3 H]PAF specific receptor binding to human leukocytes than to human platelets. Mg 2+ , Ca 2+ and K + ions potentiated the [ 3 H]PAF specific binding in both systems. Na + ions inhibited the [ 3 H]PAF specific binding to human platelets but showed no effects in human leukocytes. K + ions decreased the Mg 2+ -potentiated [ 3 H]PAF binding in human leukocytes but showed no effects in human platelets. These results suggest that the PAF specific receptors in human leukocytes are different structurally and possibly functionally from the receptors identified in human platelets

  8. Expression of the epidermal growth factor receptor in human small cell lung cancer cell lines

    DEFF Research Database (Denmark)

    Damstrup, L; Rygaard, K; Spang-Thomsen, M

    1992-01-01

    of EGF receptor mRNA in all 10 cell lines that were found to be EGF receptor-positive and in one cell line that was found to be EGF receptor-negative in the radioreceptor assay and affinity labeling. Our results provide, for the first time, evidence that a large proportion of a broad panel of small cell......Epidermal growth factor (EGF) receptor expression was evaluated in a panel of 21 small cell lung cancer cell lines with radioreceptor assay, affinity labeling, and Northern blotting. We found high-affinity receptors to be expressed in 10 cell lines. Scatchard analysis of the binding data...... demonstrated that the cells bound between 3 and 52 fmol/mg protein with a KD ranging from 0.5 x 10(-10) to 2.7 x 10(-10) M. EGF binding to the receptor was confirmed by affinity-labeling EGF to the EGF receptor. The cross-linked complex had a M(r) of 170,000-180,000. Northern blotting showed the expression...

  9. Ric-8A, a Gα protein guanine nucleotide exchange factor potentiates taste receptor signaling

    Directory of Open Access Journals (Sweden)

    Claire J Fenech

    2009-10-01

    Full Text Available Taste receptors for sweet, bitter and umami tastants are G-protein coupled receptors (GPCRs. While much effort has been devoted to understanding G-protein-receptor interactions and identifying the components of the signalling cascade downstream of these receptors, at the level of the G-protein the modulation of receptor signal transduction remains relatively unexplored. In this regard a taste-specific regulator of G-protein signaling (RGS, RGS21, has recently been identified. To study whether guanine nucleotide exchange factors (GEFs are involved in the transduction of the signal downstream of the taste GPCRs we investigated the expression of Ric-8A and Ric-8B in mouse taste cells and their interaction with G-protein subunits found in taste buds. Mammalian Ric-8 proteins were initially identified as potent GEFs for a range of Gα subunits and Ric-8B has recently been shown to amplify olfactory signal transduction. We find that both Ric-8A and Ric-8B are expressed in a large portion of taste bud cells and that most of these cells contain IP3R-3 a marker for sweet, umami and bitter taste receptor cells. Ric-8A interacts with Gα-gustducin and Gαi2 through which it amplifies the signal transduction of hTas2R16, a receptor for bitter compounds. Overall, these findings are consistent with a role for Ric-8 in mammalian taste signal transduction.

  10. ErbB2 resembles an autoinhibited invertebrate epidermal growth factor receptor

    Energy Technology Data Exchange (ETDEWEB)

    Alvarado, Diego; Klein, Daryl E.; Lemmon, Mark A.; (UPENN-MED)

    2009-09-25

    The orphan receptor tyrosine kinase ErbB2 (also known as HER2 or Neu) transforms cells when overexpressed, and it is an important therapeutic target in human cancer. Structural studies have suggested that the oncogenic (and ligand-independent) signalling properties of ErbB2 result from the absence of a key intramolecular 'tether' in the extracellular region that autoinhibits other human ErbB receptors, including the epidermal growth factor (EGF) receptor. Although ErbB2 is unique among the four human ErbB receptors, here we show that it is the closest structural relative of the single EGF receptor family member in Drosophila melanogaster (dEGFR). Genetic and biochemical data show that dEGFR is tightly regulated by growth factor ligands, yet a crystal structure shows that it, too, lacks the intramolecular tether seen in human EGFR, ErbB3 and ErbB4. Instead, a distinct set of autoinhibitory interdomain interactions hold unliganded dEGFR in an inactive state. All of these interactions are maintained (and even extended) in ErbB2, arguing against the suggestion that ErbB2 lacks autoinhibition. We therefore suggest that normal and pathogenic ErbB2 signalling may be regulated by ligands in the same way as dEGFR. Our findings have important implications for ErbB2 regulation in human cancer, and for developing therapeutic approaches that target novel aspects of this orphan receptor.

  11. Peptides derived from specific interaction sites of the fibroblast growth factor 2 - FGF receptor complexes induce receptor activation and signaling

    DEFF Research Database (Denmark)

    Manfè, Valentina; Kochoyan, Artur; Bock, Elisabeth

    2010-01-01

    J. Neurochem. (2010) 10.1111/j.1471-4159.2010.06718.x Abstract Basic fibroblast growth factor (FGF2, bFGF) is the most extensively studied member of the FGF family and is involved in neurogenesis, differentiation, neuroprotection, and synaptic plasticity in the CNS. FGF2 executes its pleiotropic...... biologic actions by binding, dimerizing, and activating FGF receptors (FGFRs). The present study reports the physiologic impact of various FGF2-FGFR1 contact sites employing three different synthetic peptides, termed canofins, designed based on structural analysis of the interactions between FGF2 and FGFR1...

  12. Thyroid hormone and retinoic acid nuclear receptors: specific ligand-activated transcription factors

    International Nuclear Information System (INIS)

    Brtko, J.

    1998-01-01

    Transcriptional regulation by both the thyroid hormone and the vitamin A-derived 'retinoid hormones' is a critical component in controlling many aspects of higher vertebrate development and metabolism. Their functions are mediated by nuclear receptors, which comprise a large super-family of ligand-inducible transcription factors. Both the thyroid hormone and the retinoids are involved in a complex arrangement of physiological and development responses in many tissues of higher vertebrates. The functions of 3,5,3'-triiodothyronine (T 3 ), the thyromimetically active metabolite of thyroxine as well as all-trans retinoic acid, the biologically active vitamin A metabolite are mediated by nuclear receptor proteins that are members of the steroid/thyroid/retinoid hormone receptor family. The functions of all members of the receptor super family are discussed. (authors)

  13. Inactivation of the transforming growth factor beta type II receptor in human small cell lung cancer cell lines

    DEFF Research Database (Denmark)

    Hougaard, S; Nørgaard, P; Abrahamsen, N

    1999-01-01

    Transforming growth factor beta (TGF-beta) exerts a growth inhibitory effect on many cell types through binding to two types of receptors, the type I and II receptors. Resistance to TGF-beta due to lack of type II receptor (RII) has been described in some cancer types including small cell lung...

  14. Type-I Insulin-Like Growth Factor Receptor (IGF1R)-Estrogen Receptor (ER) Crosstalk Contributes to Antiestrogen Therapy Resistance in Breast Cancer Cells

    Science.gov (United States)

    2013-02-01

    vitro have downregulated J GF1R making antibodies directed agai nst th is receptor ineffective. Inhlbition of IH may be necessary to manage ...monoclonal antibody to insulin-like growth factor receptor 1. J Clin Oncol 2009;27:580Q-7. 31. Drury s. Detre s. Leary A, Salter J, Reis-Filho J

  15. Up-regulation of proproliferative genes and the ligand/receptor pair placental growth factor and vascular endothelial growth factor receptor 1 in hepatitis C cirrhosis.

    Science.gov (United States)

    Huang, Xiao X; McCaughan, Geoffrey W; Shackel, Nicholas A; Gorrell, Mark D

    2007-09-01

    Cirrhosis can lead to hepatocellular carcinoma (HCC). Non-diseased liver and hepatitis C virus (HCV)-associated cirrhosis with or without HCC were compared. Proliferation pathway genes, immune response genes and oncogenes were analysed by a quantitative real-time reverse transcriptase-polymerase chain reaction (RT-PCR) and immunostaining. Real-time RT-PCR showed up-regulation of genes in HCV cirrhosis including the proliferation-associated genes bone morphogenetic protein 3 (BMP3), placental growth factor 3 (PGF3), vascular endothelial growth factor receptor 1 (VEGFR1) and soluble VEGFR1, the oncogene FYN, and the immune response-associated genes toll-like receptor 9 (TLR9) and natural killer cell transcript 4 (NK4). Expressions of TLR2 and the oncogenes B-cell CLL/lymphoma 9 (BCL9) and PIM2 were decreased in HCV cirrhosis. In addition, PIM2 and TLR2 were increased in HCV cirrhosis with HCC compared with HCV cirrhosis. The ligand/receptor pair PGF and VEGFR1 was intensely expressed by the portal tract vascular endothelium. VEGFR1 was expressed in reactive biliary epithelial structures in fibrotic septum and in some stellate cells and macrophages. PGF and VEGFR1 may have an important role in the pathogenesis of the neovascular response in cirrhosis.

  16. Characterization of receptors for recombinant human tumor necrosis factor-alpha from human placental membranes

    International Nuclear Information System (INIS)

    Aiyer, R.A.; Aggarwal, B.B.

    1990-01-01

    High affinity receptors for recombinant human tumor necrosis factor-alpha (rhTNF-alpha) were identified on membranes prepared from full term human placenta. Highly purified rhTNF-alpha iodinated by the iodogen method was found to bind placental membranes in a displaceable manner with an approximate dissociation constant (KD) of 1.9 nM. The membrane bound TNF-alpha receptor could be solubilized by several detergents with optimum extraction being obtained with 1% Triton X-100. The binding of 125I-rhTNF-alpha to the solubilized receptor was found to be time and temperature dependent, yielding maximum binding within 1 h, 24 h and 48 h at 37 degrees C, 24 degrees C and 4 degrees C, respectively. However, the maximum binding obtainable at 4 degrees C was only 40% of that at 37 degrees C. The binding 125I-rhTNF-alpha to solubilized placental membrane extracts was displaceable by unlabeled rhTNF-alpha, but not by a related protein recombinant human tumor necrosis factor-beta (rhTNF-beta; previously called lymphotoxin). This is similar to the behavior of TNF-alpha receptors derived from detergent-solubilized cell extracts, although on intact cells, both rhTNF-alpha and rhTNF-beta bind with equal affinity to TNF receptors. The Scatchard analysis of the binding data of the solubilized receptor revealed high affinity binding sites with a KD of approximately 0.5 nM and a receptor concentration of about 1 pmole/mg protein. Gel filtration of the solubilized receptor-ligand complexes on Sephacryl S-300 revealed two different peaks of radioactivity at approximate molecular masses of 50,000 Da and 400,000 Da. The 400,000 dalton peak corresponded to the receptor-ligand complex. Overall, our results suggest that high affinity receptors for TNF-alpha are present on human placental membranes and provide evidence that these receptors may be different from that of rhTNF-beta

  17. Insulin-like growth factor-II (IGF II) receptor from rat brain is of lower apparent molecular weight than the IGF II receptor from rat liver

    International Nuclear Information System (INIS)

    McElduff, A.; Poronnik, P.; Baxter, R.C.

    1987-01-01

    The binding subunits of the insulin and insulin-like growth factor-I (IGF I) receptors from rat brain are of lower molecular weight than the corresponding receptor in rat liver, possibly due to variations in sialic acid content. We have compared the IGF II receptor from rat brain and rat liver. The brain receptor is of smaller apparent mol wt (about 10 K) on sodium dodecyl sulfate polyacrylamide gel electrophoresis. This size difference is independent of ligand binding as it persists in iodinated and specifically immunoprecipitated receptors. From studies of wheat germ agglutinin binding and the effect of neuraminidase on receptor mobility, we conclude that this difference is not simply due to variations in sialic acid content. Treatment with endoglycosidase F results in reduction in the molecular size of both liver and brain receptors and after this treatment the aglycoreceptors are of similar size. We conclude that in rat brain tissue the IGF II receptor like the binding subunits of the insulin and IGF I receptors is of lower molecular size than the corresponding receptors in rat liver. This difference is due to differences in N-linked glycosylation

  18. Self-phosphorylation of epidermal growth factor receptor: evidence for a model of intermolecular allosteric activation

    International Nuclear Information System (INIS)

    Yarden, Y.; Schlessinger, J.

    1987-01-01

    The membrane receptor for epidermal growth factor (EGF) is a 170,000 dalton glycoprotein composed of an extracellular EGF-binding domain and a cytoplasmic kinase domain connected by a stretch of 23 amino acids traversing the plasma membrane. The binding of EGF to the extracellular domain activates the cytoplasmic kinase function even in highly purified preparations of EGF receptor, suggesting that the activation occurs exclusively within the EGF receptor moiety. Conceivably, kinase activation may require the transfer of a conformational change through the single transmembrane region from the ligand binding domain to the cytoplasmic kinase region. Alternatively, ligand-induced receptor-receptor interactions may activate the kinase and thus bypass this requirement. Both mechanisms were contrasted by employing independent experimental approaches. On the basis of these results, an allosteric aggregation model is formulated for the activation of the cytoplasmic kinase function of the receptor by EGF. This model may be relevant to the mechanism by which the mitogenic signal of EGF is transferred across the membrane

  19. Sperm Impairment by Sperm Agglutinating Factor Isolated from Escherichia coli: Receptor Specific Interactions

    Directory of Open Access Journals (Sweden)

    Kiranjeet Kaur

    2013-01-01

    Full Text Available In an earlier work done in our laboratory, we have been able to isolate a sperm agglutinating strain of Escherichia coli from the semen sample of a male attending infertility clinic. Further, factor responsible for sperm agglutination (SAF was isolated and purified, and, using SAF as a tool, corresponding SAF binding receptor from human spermatozoa has been purified. Characterization of SAF and SAF binding receptor using MALDI-TOF showed homology to glutamate decarboxylase and MHC class I molecule, respectively. Coincubation of SAF with spermatozoa not only resulted in spermagglutination but could also compromise other sperm parameters, namely, Mg2+ dependent ATPase activity and apoptosis. Intravaginal administration of SAF could lead to infertility in Balb/c mice. SAF induced impairment of sperm parameters, and infertility was observed to be due to interaction of SAF with sperm surface receptor component as, when purified receptor was introduced, receptor completely inhibited all the detrimental effects induced by SAF. From these results, it could be concluded that interaction of SAF with spermatozoa is receptor mediated.

  20. The under-appreciated promiscuity of the epidermal growth factor receptor family.

    Directory of Open Access Journals (Sweden)

    Sean P Kennedy

    2016-08-01

    Full Text Available Each member of the epidermal growth factor receptor (EGFR family plays a key role in normal development, homeostasis and a variety of pathophysiological conditions, most notably in cancer. According to the prevailing dogma, these four receptor tyrosine kinases (RTKs; EGFR, ERBB2, ERBB3 and ERBB4 function exclusively through the formation of homodimers and heterodimers within the EGFR family. These combinatorial receptor interactions are known to generate increased interactome diversity and therefore influence signalling output, subcellular localization and function of the heterodimer. This molecular plasticity is also thought to play a role in the development of resistance towards targeted cancer therapies aimed at these known oncogenes. Interestingly, many studies now challenge this dogma and suggest that the potential for EGFR family receptors to interact with more distantly related RTKs is much greater than currently appreciated. Here we discuss how the promiscuity of these oncogenic receptors may lead to the formation of many unexpected receptor pairings and the significant implications for the efficiency of many targeted cancer therapies.

  1. Association of nerve growth factor receptors with the triton X-100 cytoskeleton of PC12 cells

    International Nuclear Information System (INIS)

    Vale, R.D.; Ignatius, M.J.; Shooter, E.M.

    1985-01-01

    Triton X-100 solubilizes membranes of PC12 cells and leaves behind a nucleus and an array of cytoskeletal filaments. Nerve growth factor (NGF) receptors are associated with this Triton X-100-insoluble residue. Two classes of NGF receptors are found on PC12 cells which display rapid and slow dissociating kinetics. Although rapidly dissociating binding is predominant (greater than 75%) in intact cells, the majority of binding to the Triton X-100 cytoskeleton is slowly dissociating (greater than 75%). Rapidly dissociating NGF binding on intact cells can be converted to a slowly dissociating form by the plant lectin wheat germ agglutinin (WGA). This lectin also increases the number of receptors which associate with the Triton X-100 cytoskeleton by more than 10-fold. 125 I-NGF bound to receptors can be visualized by light microscopy autoradiography in Triton X-100-insoluble residues of cell bodies, as well as growth cones and neurites. The WGA-induced association with the cytoskeleton, however, is not specific for the NGF receptor. Concentrations of WGA which change the Triton X-100 solubility of membrane glycoproteins are similar to those required to alter the kinetic state of the NGF receptor. Both events may be related to the crossbridging of cell surface proteins induced by this multivalent lectin

  2. Design and Synthesis of Benzimidazoles As Novel Corticotropin-Releasing Factor 1 Receptor Antagonists.

    Science.gov (United States)

    Mochizuki, Michiyo; Kori, Masakuni; Kobayashi, Katsumi; Yano, Takahiko; Sako, Yuu; Tanaka, Maiko; Kanzaki, Naoyuki; Gyorkos, Albert C; Corrette, Christopher P; Cho, Suk Young; Pratt, Scott A; Aso, Kazuyoshi

    2016-03-24

    Benzazole derivatives with a flexible aryl group bonded through a one-atom linker as a new scaffold for a corticotropin-releasing factor 1 (CRF1) receptor antagonist were designed, synthesized, and evaluated. We expected that structural diversity could be expanded beyond that of reported CRF1 receptor antagonists. In a structure-activity relationship study, 4-chloro-N(2)-(4-chloro-2-methoxy-6-methylphenyl)-1-methyl-N(7),N(7)-dipropyl-1H-benzimidazole-2,7-diamine 29g had the most potent binding activity against a human CRF1 receptor and the antagonistic activity (IC50 = 9.5 and 88 nM, respectively) without concerns regarding cytotoxicity at 30 μM. Potent CRF1 receptor-binding activity in brain in an ex vivo test and suppression of stress-induced activation of the hypothalamus-pituitary-adrenocortical (HPA) axis were also observed at 138 μmol/kg of compound 29g after oral administration in mice. Thus, the newly designed benzimidazole 29g showed in vivo CRF1 receptor antagonistic activity and good brain penetration, indicating that it is a promising lead for CRF1 receptor antagonist drug discovery research.

  3. Characterization of cell-surface receptors for monoclonal-nonspecific suppressor factor (MNSF)

    International Nuclear Information System (INIS)

    Nakamura, M.; Ogawa, H.; Tsunematsu, T.

    1990-01-01

    Monoclonal-nonspecific suppressor factor (MNSF) is a lymphokine derived from murine T cell hybridoma. The target tissues are both LPS-stimulated B cells and Con A-stimulated T cells. Since the action of MNSF may be mediated by its binding to specific cell surface receptors, we characterized the mode of this binding. The purified MNSF was labeled with 125 I, using the Bolton-Hunter reagent. The labeled MNSF bound specifically to a single class of receptor (300 receptors per cell) on mitogen-stimulated murine B cells or T cells with an affinity of 16 pM at 24 degrees C, in the presence of sodium azide. Competitive experiments showed that MNSF bound to the specific receptor and that the binding was not shared with IL2, IFN-gamma, and TNF. Various cell types were surveyed for the capacity to specifically bind 125 I-MNSF. 125 I-MNSF bound to MOPC-31C (a murine plasmacytoma line) and to EL4 (a murine T lymphoma line). The presence of specific binding correlates with the capacity of the cells to respond to MNSF. These data support the view that like other polypeptide hormones, the action of MNSF is mediated by specific cell surface membrane receptor protein. Identification of these receptors will provide insight into the apparently diverse activities of MNSF

  4. Soluble receptors for tumor necrosis factor as markers of disease activity in visceral leishmaniasis

    NARCIS (Netherlands)

    Zijlstra, E. E.; van der Poll, T.; Mevissen, M.

    1995-01-01

    Serum concentrations of soluble receptors for tumor necrosis factor (sTNFRs) were measured before and after antimony therapy in 25 Sudanese patients with active visceral leishmaniasis (VL). Both sTNFR types I and II were significantly elevated in patients with VL compared with healthy controls from

  5. Brain-derived neurotrophic factor in human subjects with function-altering melanocortin-4 receptor variants

    Science.gov (United States)

    In rodents, hypothalamic brain-derived neurotrophic factor (BDNF) expression appears to be regulated by melanocortin-4 receptor (MC4R) activity. The impact of MC4R genetic variation on circulating BDNF in humans is unknown. The objective of this study is to compare BDNF concentrations of subjects wi...

  6. Changes in epidermal growth factor receptor expression during chemotherapy in non-small cell lung cancer

    DEFF Research Database (Denmark)

    Jakobsen, Jan Nyrop; Santoni-Rugiu, Eric; Sørensen, Jens Benn

    2014-01-01

    BACKGROUND: Antibodies targeting epidermal growth factor receptor (EGFR), such as cetuximab, may potentially improve outcome in non-small cell lung cancer (NSCLC) patients with high EGFR expression. The EGFR expression may be heterogeneously distributed within tumors, and small biopsies may thus...

  7. Amplification of epidermal growth factor receptor gene in renal cell carcinoma

    DEFF Research Database (Denmark)

    El-Hariry, Iman; Powles, Thomas; Lau, Mike R

    2010-01-01

    Expression of epidermal growth factor receptor (EGFR) may be of prognostic value in renal cell cancer (RCC). Gene amplification of EGFR was investigated in a cohort of 315 patients with advanced RCC from a previously reported randomised study. Using fluorescent in situ hybridisation, only 2...

  8. Localization and functional roles of corticotropin-releasing factor receptor type 2 in the cerebellum

    NARCIS (Netherlands)

    Gounko, Natalia V.; Gramsbergen, Albert; van der Want, Johannes J. L.

    The corticotropin-releasing factor (CRF) type 2 receptor has three splice variants alpha, beta, and gamma. In the rodent brain only CRF-R2 alpha is present. In the cerebellum, CRF-R2 alpha has two different isoforms: a full-length form (fl) and truncated (tr). Both forms CRF-R2 have a unique

  9. Orphan nuclear receptor TR4 and fibroblast growth factor 1 in metabolism

    NARCIS (Netherlands)

    Liu, Weilin

    2016-01-01

    Metabolic homeostasis is achieved, in part, through the coordinated activities of members of the Nuclear Receptor (NR) family, a superfamily of ligand-modulated transcription factors (TFs) that mediate responses to a wide range of lipophilic signaling molecules including lipids, steroids, retinoids,

  10. Cell-Cell Adhesion and Insulin-Like Growth Factor I Receptor in Breast Cancer

    National Research Council Canada - National Science Library

    Bartucci, Monica

    2001-01-01

    .... Our goal was to study the role of the insulin-like growth factor I receptor (IGF-IR) in breast cancer. The IGF-IR is a multifunctional tyrosine kinase that has been recently implicated in breast tumor development and progression...

  11. Cloning of the DNA-binding subunit of human nuclear factor κB: The level of its mRNA is strongly regulated by phorbol ester or tumor necrosis factor α

    International Nuclear Information System (INIS)

    Meyer, R.; Hatada, E.N.; Bartsch, C.; Scheidereit, C.; Hohmann, H.P.; Haiker, M.; Roethlisberger, U.; Lahm, H.W.; Schlaeger, E.J.; van Loon, A.P.G.M.

    1991-01-01

    The DNA binding subunit of nuclear factor κB (NF-κB), a B-cell protein that interacts with the immunoglobulin κ light-chain gene enhancer, has been purified from nuclei of human HL-60 cells stimulated with tumor necrosis factor α (TNFα), and internal peptide sequences were obtained. Overlapping cDNA clones were isolated and sequenced. The encoded open reading frame of about 105 kDa contained at its N-terminal half all six tryptic peptide sequences, suggesting that the 51-kDa NF-κB protein is processed from a 105-kDa precursor. An in vitro synthesized protein containing most of the N-terminal half of the open reading frame bound specifically to an NF-κB binding site. This region also showed high homology to a domain shared by the Drosophila dorsal gene and the avian and mammalian rel (proto)oncogene products. The level of the 3.8-kilobase mRNA was strongly increased after stimulation with TNFα or phorbol ester. Thus, both factors not only activate NF-κB protein, as described previously, but also induce expression of the gene encoding the DNA-binding subunit of NF-κB

  12. Loss of connective tissue growth factor as an unfavorable prognosis factor activates miR-18b by PI3K/AKT/C-Jun and C-Myc and promotes cell growth in nasopharyngeal carcinoma.

    Science.gov (United States)

    Yu, X; Zhen, Y; Yang, H; Wang, H; Zhou, Y; Wang, E; Marincola, F M; Mai, C; Chen, Y; Wei, H; Song, Y; Lyu, X; Ye, Y; Cai, L; Wu, Q; Zhao, M; Hua, S; Fu, Q; Zhang, Y; Yao, K; Liu, Z; Li, X; Fang, W

    2013-05-16

    Connective tissue growth factor (CTGF) has different roles in different types of cancer. However, the involvement and molecular basis of CTGF in tumor progression and prognosis of human nasopharyngeal carcinoma (NPC) have almost never been reported. In this study, we observed that downregulated CTGF expression was significantly associated with NPC progression and poor prognosis. Knockdown of CTGF markedly elevated the ability of cell proliferation in vivo and in vitro. Subsequently, we discovered that the reduction of CTGF increased the expression of miR-18b, an oncomir-promoting cell proliferation. Further, we discovered that attenuated CTGF-mediated upregulation of miR-18b was dependent on the increased binding of transcription factors Jun proto-oncogene (C-Jun) and v-Myc myelocytomatosis viral oncogene homolog (C-Myc) to miR-18b promoter region via phosphoinositide 3-kinase (PI3K)/AKT pathway. Finally, we further found that miR-18b directly suppressed the expression of CTGF in NPC. In clinical fresh specimens, miR-18b was widely overexpressed and inversely correlated with CTGF expression in NPC. Our studies are the first to demonstrate that reduced CTGF as an unfavorable prognosis factor mediates the activation of miR-18b, an oncomir directly suppresses CTGF expression, by PI3K/AKT/C-Jun and C-Myc and promotes cell growth of NPC.

  13. Palliation of bone cancer pain by antagonists of platelet-activating factor receptors.

    Directory of Open Access Journals (Sweden)

    Katsuya Morita

    Full Text Available Bone cancer pain is the most severe among cancer pain and is often resistant to current analgesics. Thus, the development of novel analgesics effective at treating bone cancer pain are desired. Platelet-activating factor (PAF receptor antagonists were recently demonstrated to have effective pain relieving effects on neuropathic pain in several animal models. The present study examined the pain relieving effect of PAF receptor antagonists on bone cancer pain using the femur bone cancer (FBC model in mice. Animals were injected with osteolytic NCTC2472 cells into the tibia, and subsequently the effects of PAF receptor antagonists on pain behaviors were evaluated. Chemical structurally different type of antagonists, TCV-309, BN 50739 and WEB 2086 ameliorated the allodynia and improved pain behaviors such as guarding behavior and limb-use abnormalities in FBC model mice. The pain relieving effects of these antagonists were achieved with low doses and were long lasting. Blockade of spinal PAF receptors by intrathecal injection of TCV-309 and WEB 2086 or knockdown of the expression of spinal PAF receptor protein by intrathecal transfer of PAF receptor siRNA also produced a pain relieving effect. The amount of an inducible PAF synthesis enzyme, lysophosphatidylcholine acyltransferase 2 (LPCAT2 protein significantly increased in the spinal cord after transplantation of NCTC 2472 tumor cells into mouse tibia. The combination of morphine with PAF receptor antagonists develops marked enhancement of the analgesic effect against bone cancer pain without affecting morphine-induced constipation. Repeated administration of TCV-309 suppressed the appearance of pain behaviors and prolonged survival of FBC mice. The present results suggest that PAF receptor antagonists in combination with, or without, opioids may represent a new strategy for the treatment of persistent bone cancer pain and improve the quality of life of patients.

  14. Neomycin is a platelet-derived growth factor (PDGF) antagonist that allows discrimination of PDGF alpha- and beta-receptor signals in cells expressing both receptor types.

    Science.gov (United States)

    Vassbotn, F S; Ostman, A; Siegbahn, A; Holmsen, H; Heldin, C H

    1992-08-05

    The aminoglycoside neomycin has recently been found to affect certain platelet-derived growth factor (PDGF) responses in C3H/10T1/2 C18 fibroblasts. Using porcine aortic endothelial cells transfected with PDGF alpha- or beta-receptors, we explored the possibility that neomycin interferes with the interaction between the different PDGF isoforms and their receptors. We found that neomycin (5 mM) inhibited the binding of 125I-PDGF-BB to the alpha-receptor with only partial effect on the binding of 125I-PDGF-AA; in contrast, the binding of 125I-PDGF-BB to the beta-receptor was not affected by the aminoglycoside. Scatchard analyses showed that neomycin (5 mM) decreased the number of binding sites for PDGF-BB on alpha-receptor-expressing cells by 87%. Together with cross-competition studies with 125I-labeled PDGF homodimers, the effect of neomycin indicates that PDGF-AA and PDGF-BB bind to both common and unique structures on the PDGF alpha-receptor. Neomycin specifically inhibited the autophosphorylation of the alpha-receptor by PDGF-BB, with less effect on the phosphorylation induced by PDGF-AA and no effect on the phosphorylation of the beta-receptor by PDGF-BB. Thus, neomycin is a PDGF isoform- and receptor-specific antagonist that provides a possibility to compare the signal transduction pathways of alpha- and beta-receptors in cells expressing both receptor types. This approach was used to show that activation of PDGF beta-receptors by PDGF-BB mediated a chemotactic response in human fibroblasts, whereas activation of alpha-receptors by the same ligand inhibited chemotaxis.

  15. Linking γ-aminobutyric acid A receptor to epidermal growth factor receptor pathways activation in human prostate cancer.

    Science.gov (United States)

    Wu, Weijuan; Yang, Qing; Fung, Kar-Ming; Humphreys, Mitchell R; Brame, Lacy S; Cao, Amy; Fang, Yu-Ting; Shih, Pin-Tsen; Kropp, Bradley P; Lin, Hsueh-Kung

    2014-03-05

    Neuroendocrine (NE) differentiation has been attributed to the progression of castration-resistant prostate cancer (CRPC). Growth factor pathways including the epidermal growth factor receptor (EGFR) signaling have been implicated in the development of NE features and progression to a castration-resistant phenotype. However, upstream molecules that regulate the growth factor pathway remain largely unknown. Using androgen-insensitive bone metastasis PC-3 cells and androgen-sensitive lymph node metastasis LNCaP cells derived from human prostate cancer (PCa) patients, we demonstrated that γ-aminobutyric acid A receptor (GABA(A)R) ligand (GABA) and agonist (isoguvacine) stimulate cell proliferation, enhance EGF family members expression, and activate EGFR and a downstream signaling molecule, Src, in both PC-3 and LNCaP cells. Inclusion of a GABA(A)R antagonist, picrotoxin, or an EGFR tyrosine kinase inhibitor, Gefitinib (ZD1839 or Iressa), blocked isoguvacine and GABA-stimulated cell growth, trans-phospohorylation of EGFR, and tyrosyl phosphorylation of Src in both PCa cell lines. Spatial distributions of GABAAR α₁ and phosphorylated Src (Tyr416) were studied in human prostate tissues by immunohistochemistry. In contrast to extremely low or absence of GABA(A)R α₁-positive immunoreactivity in normal prostate epithelium, elevated GABA(A)R α₁ immunoreactivity was detected in prostate carcinomatous glands. Similarly, immunoreactivity of phospho-Src (Tyr416) was specifically localized and limited to the nucleoli of all invasive prostate carcinoma cells, but negative in normal tissues. Strong GABAAR α₁ immunoreactivity was spatially adjacent to the neoplastic glands where strong phospho-Src (Tyr416)-positive immunoreactivity was demonstrated, but not in adjacent to normal glands. These results suggest that the GABA signaling is linked to the EGFR pathway and may work through autocrine or paracine mechanism to promote CRPC progression. Copyright © 2013 Elsevier

  16. The Transcription Factor c-Maf Promotes the Differentiation of Follicular Helper T Cells

    Directory of Open Access Journals (Sweden)

    Fabienne Andris

    2017-04-01

    Full Text Available Follicular helper T cells (Tfh have been identified as the primary cell subpopulation regulating B cell responses in germinal centers, thus supporting high-affinity antibody production. Among the transcription factors orchestrating Tfh cell differentiation and function, the role played by the proto-oncogene c-Maf remains poorly characterized. We report herein that selective loss of c-Maf expression in the T cell compartment results in defective development of Tfh cells in response to both antigen/adjuvant vaccinations and commensal intestinal bacteria. Accordingly, c-Maf expression in T cells was essential for the development and high-affinity antibody secretion in vaccinated animals. c-Maf was expressed early, concomitantly to BCL6, in Tfh cell precursors and found to regulate Tfh fate in a cell-autonomous fashion. Altogether, our findings reveal a novel, non-redundant, function for c-Maf in the differentiation of Tfh cells and the regulation of humoral immune responses to T-cell-dependent antigens.

  17. Wnt signalling via the epidermal growth factor receptor: a role in breast cancer?

    International Nuclear Information System (INIS)

    Musgrove, Elizabeth A

    2004-01-01

    Recent data have suggested the epidermal-growth-factor receptor (EGFR) as a point of convergence for several different classes of receptor. Civenni and colleagues have now demonstrated crosstalk between Wnt signalling and the EGFR, showing that in breast epithelial cells Wnts activate downstream targets of the EGFR, including cyclin D1. Given the role of members of these pathways in the aetiology of breast cancer and as markers of outcome and potential therapeutic targets in breast cancer, this observation has a number of potential implications important for both the basic biology of breast cancer and the clinical management of the disease

  18. The diminished expression of proangiogenic growth factors and their receptors in gastric ulcers of cirrhotic patients.

    Science.gov (United States)

    Luo, Jiing-Chyuan; Peng, Yen-Ling; Hou, Ming-Chih; Huang, Kuang-Wei; Huang, Hui-Chun; Wang, Ying-Wen; Lin, Han-Chieh; Lee, Fa-Yauh; Lu, Ching-Liang

    2013-01-01

    The pathogenesis of the higher occurrence of peptic ulcer disease in cirrhotic patients is complex. Platelets can stimulate angiogenesis and promote gastric ulcer healing. We compared the expressions of proangiogenic growth factors and their receptors in the gastric ulcer margin between cirrhotic patients with thrombocytopenia and those of non-cirrhotic patients to elucidate possible mechanisms. Eligible cirrhotic patients (n = 55) and non-cirrhotic patients (n = 55) who had gastric ulcers were enrolled. Mucosa from the gastric ulcer margin and non-ulcer areas were sampled and the mRNA expressions of the proangiogenic growth factors (vascular endothelial growth factor [VEGF], platelet derived growth factor [PDGF], basic fibroblast growth factor [bFGF]) and their receptors (VEGFR1, VEGFR2, PDGFRA, PDGFRB, FGFR1, FGFR2) were measured and compared. Platelet count and the expressions of these growth factors and their receptors were correlated with each other. The two groups were comparable in terms of gender, ulcer size and infection rate of Helicobacter pylori. However, the cirrhotic group were younger in age, had a lower platelet count than those in the non-cirrhotic group (pexpressions of PDGFB, VEGFR2, FGFR1, and FGFR2 in gastric ulcer margin when compared with those of the non-cirrhotic patients (pexpressions of PDGFB and VEGFR2, FGFR1, and FGFR2 were well correlated with the degree of thrombocytopenia in these cirrhotic patients (ρ>0.5, pimplied that diminished activity of proangiogenic factors and their receptors may contribute to the pathogenesis of gastric ulcers in cirrhotic patients.

  19. Two signaling molecules share a phosphotyrosine-containing binding site in the platelet-derived growth factor receptor.

    Science.gov (United States)

    Nishimura, R; Li, W; Kashishian, A; Mondino, A; Zhou, M; Cooper, J; Schlessinger, J

    1993-11-01

    Autophosphorylation sites of growth factor receptors with tyrosine kinase activity function as specific binding sites for Src homology 2 (SH2) domains of signaling molecules. This interaction appears to be a crucial step in a mechanism by which receptor tyrosine kinases relay signals to downstream signaling pathways. Nck is a widely expressed protein consisting exclusively of SH2 and SH3 domains, the overexpression of which causes cell transformation. It has been shown that various growth factors stimulate the phosphorylation of Nck and its association with autophosphorylated growth factor receptors. A panel of platelet-derived growth factor (PDGF) receptor mutations at tyrosine residues has been used to identify the Nck binding site. Here we show that mutation at Tyr-751 of the PDGF beta-receptor eliminates Nck binding both in vitro and in living cells. Moreover, the Y751F PDGF receptor mutant failed to mediate PDGF-stimulated phosphorylation of Nck in intact cells. A phosphorylated Tyr-751 is also required for binding of phosphatidylinositol-3 kinase to the PDGF receptor. Hence, the SH2 domains of p85 and Nck share a binding site in the PDGF receptor. Competition experiments with different phosphopeptides derived from the PDGF receptor suggest that binding of Nck and p85 is influenced by different residues around Tyr-751. Thus, a single tyrosine autophosphorylation site is able to link the PDGF receptor to two distinct SH2 domain-containing signaling molecules.

  20. Characterization of a receptor for human monocyte-derived neutrophil chemotactic factor/interleukin-8

    International Nuclear Information System (INIS)

    Grob, P.M.; David, E.; Warren, T.C.; DeLeon, R.P.; Farina, P.R.; Homon, C.A.

    1990-01-01

    Monocyte-derived neutrophil chemotactic factor/interleukin-8 (MDNCF/IL-8) is an 8,000-dalton protein produced by monocytes which exhibits activity as a chemoattractant for neutrophils with maximal activity achieved at a concentration of 50 ng/ml. This polypeptide has been iodinated by chloramine-T methodology (350 Ci/mM), and specific receptors for MDNCF/IL-8 have been detected on human neutrophils, U937 cells, THP-1 cells, and dimethyl sulfoxide-differentiated HL-60 cells. The binding of MDNCF/IL-8 to human neutrophils is not inhibited by interleukin-1 alpha, tumor necrosis factor-alpha, insulin, or epidermal growth factor. In addition, chemoattractants such as C5a, fMet-Leu-Phe, leukotriene B4, and platelet-activating factor fail to inhibit binding, suggesting that MDNCF/IL-8 utilizes a unique receptor. The receptor for MDNCF/IL-8 is apparently glycosylated since ligand binding is inhibited by the presence of wheat germ agglutinin, a lectin with a binding specificity for N-acetylglucosamine and neuraminic acid. Steady state binding experiments indicate Kd values of 4 and 0.5 nM and receptor numbers of 75,000 and 7,400 for human neutrophils and differentiated HL-60 cells, respectively. 125I-MDNCF/IL-8 bound to human neutrophils is rapidly internalized and subsequently released from cells as trichloroacetic acid-soluble radioactivity. Affinity labeling experiments suggest that the human neutrophil MDNCF/IL-8 receptor exhibits a mass of approximately 58,000 daltons

  1. Structural basis for receptor recognition of vitamin-B(12)-intrinsic factor complexes

    DEFF Research Database (Denmark)

    Andersen, Christian Brix Folsted; Madsen, Mette; Storm, Tina

    2010-01-01

    Cobalamin (Cbl, vitamin B(12)) is a bacterial organic compound and an essential coenzyme in mammals, which take it up from the diet. This occurs by the combined action of the gastric intrinsic factor (IF) and the ileal endocytic cubam receptor formed by the 460-kilodalton (kDa) protein cubilin...... and the 45-kDa transmembrane protein amnionless. Loss of function of any of these proteins ultimately leads to Cbl deficiency in man. Here we present the crystal structure of the complex between IF-Cbl and the cubilin IF-Cbl-binding-region (CUB(5-8)) determined at 3.3 A resolution. The structure provides...... of how Cbl indirectly induces ligand-receptor coupling. Finally, the comparison of Ca(2+)-binding CUB domains and the low-density lipoprotein (LDL) receptor-type A modules suggests that the electrostatic pairing of a basic ligand arginine/lysine residue with Ca(2+)-coordinating acidic aspartates...

  2. FTZ-Factor1 and Fushi tarazu interact via conserved nuclear receptor and coactivator motifs

    Science.gov (United States)

    Schwartz, Carol J.E.; Sampson, Heidi M.; Hlousek, Daniela; Percival-Smith, Anthony; Copeland, John W.R.; Simmonds, Andrew J.; Krause, Henry M.

    2001-01-01

    To activate transcription, most nuclear receptor proteins require coactivators that bind to their ligand-binding domains (LBDs). The Drosophila FTZ-Factor1 (FTZ-F1) protein is a conserved member of the nuclear receptor superfamily, but was previously thought to lack an AF2 motif, a motif that is required for ligand and coactivator binding. Here we show that FTZ-F1 does have an AF2 motif and that it is required to bind a coactivator, the homeodomain-containing protein Fushi tarazu (FTZ). We also show that FTZ contains an AF2-interacting nuclear receptor box, the first to be found in a homeodomain protein. Both interaction motifs are shown to be necessary for physical interactions in vitro and for functional interactions in developing embryos. These unexpected findings have important implications for the conserved homologs of the two proteins. PMID:11157757

  3. Characterization of the epidermal growth factor receptor associated with cytoskeletons of A431 cells

    International Nuclear Information System (INIS)

    Roy, L.M.; Gittinger, C.K.; Landreth, G.E.

    1989-01-01

    Epidermal growth factor receptors (EGF-R) have been shown to be associated with the detergent-insoluble cytoskeleton of A431 cells, where they retained both a functional ligand-binding domain and tyrosine kinase activity. In the present study we have characterized the tyrosine kinase and ligand binding activities of this cytoskeletally associated EGF-R. The tyrosine kinase activity of the cytoskeletally associated EGF-R was stimulated by EGF treatment of intact cells as evidenced by increased autophosphorylation and phosphorylation of the exogenous substrate angiotensin II (AII). The kinetic behavior of the EGF-R associated with cytoskeletons of EGF-treated cells was similar to that of purified receptors. The stimulation of the receptor kinase activity required EGF treatment of intact cells prior to Triton extraction. If cytoskeletons were prepared from untreated cells and then incubated with EGF, there was no stimulation of the detergent-insoluble receptor kinase activity, indicating that the immobilized receptor was unable to undergo EGF-stimulated activation. Comparison of peptide maps from soluble and cytoskeletally associated EGF-R revealed qualitatively similar patterns; however, they are distinguished by a prominent 46 kD band in digests of the cytoskeletal EGF-R. Saturable binding of 125I-EGF to A431 cytoskeletons prepared from adherent and suspended cells demonstrated the presence of specific receptors on the cytoskeleton. High-affinity EGF-R were preferentially retained upon detergent extraction of adherent cells, whereas both low- and high-affinity receptors were solubilized from the cytoskeletons of suspended cells. Suspension of cells resulted in the solubilization of an additional 15% of the EGF-R to that solubilized in adherent cells, indicating that EGF-R can reversibly associate with the structural elements of the cell

  4. Expression of platelet-derived growth factor and its receptors in proliferative disorders of fibroblastic origin.

    Science.gov (United States)

    Smits, A; Funa, K; Vassbotn, F S; Beausang-Linder, M; af Ekenstam, F; Heldin, C H; Westermark, B; Nistér, M

    1992-03-01

    Platelet-derived growth factor (PDGF) is known to stimulate the proliferation of connective tissue-derived cells in vitro. Less is known about its functions in vivo, and the role of PDGF in the development of human tumors has not been clarified. The authors have investigated the occurrence of PDGF and PDGF receptors in a series of proliferative disorders of fibroblastic origin using immunohistochemical and in situ hybridization techniques. High expression of PDGF beta-receptor mRNA and protein was found in the malignant tumors, and also in some benign lesions, such as dermatofibroma. In all these cases, benign as well as malignant, the PDGF B-chain mRNA, and less clearly, the PDGF A-chain mRNA, were coexpressed with the beta-receptor. In contrast, high expression of PDGF alpha-receptor mRNA was only found in fully malignant lesions, i.e., malignant fibrous histiocytoma. These data indicate that an autocrine growth stimulation via the PDGF beta-receptor could occur in an early phase of tumorigenesis, and may be a necessary but insufficient event for the progression into fully malignant human connective tissue lesions.

  5. A Plant Immune Receptor Detects Pathogen Effectors that Target WRKY Transcription Factors.

    Science.gov (United States)

    Sarris, Panagiotis F; Duxbury, Zane; Huh, Sung Un; Ma, Yan; Segonzac, Cécile; Sklenar, Jan; Derbyshire, Paul; Cevik, Volkan; Rallapalli, Ghanasyam; Saucet, Simon B; Wirthmueller, Lennart; Menke, Frank L H; Sohn, Kee Hoon; Jones, Jonathan D G

    2015-05-21

    Defense against pathogens in multicellular eukaryotes depends on intracellular immune receptors, yet surveillance by these receptors is poorly understood. Several plant nucleotide-binding, leucine-rich repeat (NB-LRR) immune receptors carry fusions with other protein domains. The Arabidopsis RRS1-R NB-LRR protein carries a C-terminal WRKY DNA binding domain and forms a receptor complex with RPS4, another NB-LRR protein. This complex detects the bacterial effectors AvrRps4 or PopP2 and then activates defense. Both bacterial proteins interact with the RRS1 WRKY domain, and PopP2 acetylates lysines to block DNA binding. PopP2 and AvrRps4 interact with other WRKY domain-containing proteins, suggesting these effectors interfere with WRKY transcription factor-dependent defense, and RPS4/RRS1 has integrated a "decoy" domain that enables detection of effectors that target WRKY proteins. We propose that NB-LRR receptor pairs, one member of which carries an additional protein domain, enable perception of pathogen effectors whose function is to target that domain. Copyright © 2015 Elsevier Inc. All rights reserved.

  6. Insulin-like growth factor II: complexity of biosynthesis and receptor binding

    DEFF Research Database (Denmark)

    Gammeltoft, S; Christiansen, Jan; Nielsen, F C

    1991-01-01

    Insulin-like growth factor II (IGF-II) belongs to the insulin family of peptides and acts as a growth factor in many fetal tissues and tumors. The gene expression of IGF-II is initiated at three different promoters which gives rise to multiple transcripts. In a human rhabdomyosarcoma cell line......, Man-6-P induces cellular responses. We have studied rat brain neuronal precursor cells where Man-6-P acted as a mitogen suggesting that phosphomannosylated proteins may act as growth factors via the Man-6-P/IGF-II receptor. In conclusion, the gene expression and mechanism of action of IGF-II is very...

  7. Role of tissue factor and protease-activated receptors in a mouse model of endotoxemia.

    Science.gov (United States)

    Pawlinski, Rafal; Pedersen, Brian; Schabbauer, Gernot; Tencati, Michael; Holscher, Todd; Boisvert, William; Andrade-Gordon, Patricia; Frank, Rolf Dario; Mackman, Nigel

    2004-02-15

    Sepsis is associated with a systemic activation of coagulation and an excessive inflammatory response. Anticoagulants have been shown to inhibit both coagulation and inflammation in sepsis. In this study, we used both genetic and pharmacologic approaches to analyze the role of tissue factor and protease-activated receptors in coagulation and inflammation in a mouse endotoxemia model. We used mice expressing low levels of the procoagulant molecule, tissue factor (TF), to analyze the effects of TF deficiency either in all tissues or selectively in hematopoietic cells. Low TF mice had reduced coagulation, inflammation, and mortality compared with control mice. Similarly, a deficiency of TF expression by hematopoietic cells reduced lipopolysaccharide (LPS)-induced coagulation, inflammation, and mortality. Inhibition of the down-stream coagulation protease, thrombin, reduced fibrin deposition and prolonged survival without affecting inflammation. Deficiency of either protease activated receptor-1 (PAR-1) or protease activated receptor-2 (PAR-2) alone did not affect inflammation or survival. However, a combination of thrombin inhibition and PAR-2 deficiency reduced inflammation and mortality. These data demonstrate that hematopoietic cells are the major pathologic site of TF expression during endotoxemia and suggest that multiple protease-activated receptors mediate crosstalk between coagulation and inflammation.

  8. Emerging growth factor receptor antagonists for the treatment of renal cell carcinoma.

    Science.gov (United States)

    Zahoor, Haris; Rini, Brian I

    2016-12-01

    The landscape of systemic treatment for metastatic renal cell carcinoma (RCC) has dramatically changed with the introduction of targeted agents including vascular endothelial growth factor (VEGF) inhibitors. Recently, multiple new agents including growth factor receptor antagonists and a checkpoint inhibitor were approved for the treatment of refractory metastatic RCC based on encouraging benefit shown in clinical trials. Areas covered: The background and biological rationale of existing treatment options including a brief discussion of clinical trials which led to their approval, is presented. This is followed by reviewing the limitations of these therapeutic options, medical need to develop new treatments and major goals of ongoing research. We then discuss two recently approved growth factor receptor antagonists i.e. cabozantinib and lenvatinib, and a recently approved checkpoint inhibitor, nivolumab, and issues pertaining to drug development, and future directions in treatment of metastatic RCC. Expert opinion: Recently approved growth factor receptor antagonists have shown encouraging survival benefit but associated drug toxicity is a major issue. Nivolumab, a programmed death 1 (PD-1) checkpoint inhibitor, has similarly shown survival benefit and is well tolerated. With multiple options now available in this patient population, the right sequence of these agents remains to be determined.

  9. Cognitive disorder and changes in cholinergic receptors, N-methyl-D aspartate receptors, neural cell adhesion molecule, and brain-derived neurotrophic factor following brain injury

    Institute of Scientific and Technical Information of China (English)

    Weiliang Zhao; Dezhi Kang; Yuanxiang Lin

    2008-01-01

    BACKGROUND: Learning and memory damage is one of the most permanent and the severest symptoms of traumatic brain injury; it can seriously influence the normal life and work of patients. Some research has demonstrated that cognitive disorder is closely related to nicotine cholinergic receptors, N-methyl-D aspartate receptors, neural cell adhesion molecule, and brain-derived neurotrophic factor. OBJECTIVE: To summarize the cognitive disorder and changes in nicotine cholinergic receptors, N-methyl-D aspartate receptors, neural cell adhesion molecule, and brain-derived neurotrophic factor following brain injury. RETRIEVAL STRATEGY: A computer-based online search was conducted in PUBMED for English language publications containing the key words "brain injured, cognitive handicap, acetylcholine, N-methyl-D aspartate receptors, neural cell adhesion molecule, brain-derived neurotrophic factor" from January 2000 to December 2007. There were 44 papers in total. Inclusion criteria: ① articles about changes in nicotine cholinergic receptors, N-methyl-D aspartate receptors, neural cell adhesion molecule, and brain-derived neurotrophic factor following brain injury; ② articles in the same researching circle published in authoritative journals or recently published. Exclusion criteria: duplicated articles.LITERATURE EVALUATION: References were mainly derived from research on changes in these four factors following brain injury. The 20 included papers were clinical or basic experimental studies. DATA SYNTHESIS: After craniocerebral injury, changes in these four factors in brain were similar to those during recovery from cognitive disorder, to a certain degree. Some data have indicated that activation of nicotine cholinergic receptors, N-methyl-D aspartate receptors, neural cell adhesion molecule, and brain-derived neurotrophic factor could greatly improve cognitive disorder following brain injury. However, there are still a lot of questions remaining; for example, how do these

  10. Cloning and expression of a cDNA coding for the human platelet-derived growth factor receptor: Evidence for more than one receptor class

    International Nuclear Information System (INIS)

    Gronwald, R.G.K.; Grant, F.J.; Haldeman, B.A.; Hart, C.E.; O'Hara, P.J.; Hagen, F.S.; Ross, R.; Bowen-Pope, D.F.; Murray, M.J.

    1988-01-01

    The complete nucleotide sequence of a cDNA encoding the human platelet-derived growth factor (PDGF) receptor is presented. The cDNA contains an open reading frame that codes for a protein of 1106 amino acids. Comparison to the mouse PDGF receptor reveals an overall amino acid sequence identity of 86%. This sequence identity rises to 98% in the cytoplasmic split tyrosine kinase domain. RNA blot hybridization analysis of poly(A) + RNA from human dermal fibroblasts detects a major and a minor transcript using the cDNA as a probe. Baby hamster kidney cells, transfected with an expression vector containing the receptor cDNA, express an ∼ 190-kDa cell surface protein that is recognized by an anti-human PDGF receptor antibody. The recombinant PDGF receptor is functional in the transfected baby hamster kidney cells as demonstrated by ligand-induced phosphorylation of the receptor. Binding properties of the recombinant PDGF receptor were also assessed with pure preparations of BB and AB isoforms of PDGF. Unlike human dermal fibroblasts, which bind both isoforms with high affinity, the transfected baby hamster kidney cells bind only the BB isoform of PDGF with high affinity. This observation is consistent with the existence of more than one PDGF receptor class

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

    DEFF Research Database (Denmark)

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

    2013-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Allison L Speer

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

  13. Optimal experimental design in an epidermal growth factor receptor signalling and down-regulation model.

    Science.gov (United States)

    Casey, F P; Baird, D; Feng, Q; Gutenkunst, R N; Waterfall, J J; Myers, C R; Brown, K S; Cerione, R A; Sethna, J P

    2007-05-01

    We apply the methods of optimal experimental design to a differential equation model for epidermal growth factor receptor signalling, trafficking and down-regulation. The model incorporates the role of a recently discovered protein complex made up of the E3 ubiquitin ligase, Cbl, the guanine exchange factor (GEF), Cool-1 (beta -Pix) and the Rho family G protein Cdc42. The complex has been suggested to be important in disrupting receptor down-regulation. We demonstrate that the model interactions can accurately reproduce the experimental observations, that they can be used to make predictions with accompanying uncertainties, and that we can apply ideas of optimal experimental design to suggest new experiments that reduce the uncertainty on unmeasurable components of the system.

  14. Anti-epidermal growth factor receptor skin toxicity: a matter of topical hydration.

    Science.gov (United States)

    Ferrari, Daris; Codecà, Carla; Bocci, Barbara; Crepaldi, Francesca; Violati, Martina; Viale, Giulia; Careri, Carmela; Caldiera, Sarah; Bordin, Veronica; Luciani, Andrea; Zonato, Sabrina; Cassinelli, Gabriela; Foa, Paolo

    2016-02-01

    Skin toxicity is a frequent complication of anti-epidermal growth factor receptor therapy, which can be an obstacle in maintaining the dose intensity and may negatively impact on the clinical outcome of cancer patients. Skin lesions depend on the disruption of the keratinocyte development pathways and no treatment is clearly effective in resolving the cutaneous alterations frequently found during anti-epidermal growth factor receptor therapy. Among systemic treatments, oral tetracycline proved to be useful in preventing skin manifestations. We describe the case of a patient affected by metastatic colorectal cancer, for whom a combination of chemotherapy and cetuximab was used as second-line treatment. The patient developed a symptomatic papulopustular skin rash that disappeared completely after a twice-daily application of a hydrating and moisturizing cream, mainly consisting of a mixture of paraffin, silicone compounds, and macrogol. The marked cutaneous amelioration allowed the patient to continue cetuximab without any further symptoms and was associated with a partial radiological response.

  15. Insulin-Insulin-like Growth Factors Hybrids as Molecular Probes of Hormone:Receptor Binding Specificity

    Czech Academy of Sciences Publication Activity Database

    Křížková, Květoslava; Chrudinová, Martina; Povalová, Anna; Selicharová, Irena; Collinsová, Michaela; Vaněk, Václav; Brzozowski, A. M.; Jiráček, Jiří; Žáková, Lenka

    2016-01-01

    Roč. 55, č. 21 (2016), s. 2903-2913 ISSN 0006-2960 R&D Projects: GA ČR GA15-19018S Institutional support: RVO:61388963 Keywords : alanine scanning mutagenesis * high-affinity binding * type 1 IGF receptor Subject RIV: CE - Biochemistry Impact factor: 2.938, year: 2016 http://pubs.acs.org/doi/pdf/10.1021/acs.biochem.6b00140

  16. Insulin-like Growth Factor Receptor Inhibitors: Baby or the Bathwater?

    OpenAIRE

    Yee, Douglas

    2012-01-01

    The success of targeted therapies for cancer is undisputed; strong preclinical evidence has resulted in the approval of several new agents for cancer treatment. The type I insulin-like growth factor receptor (IGF1R) appeared to be one of these promising new targets. Substantial population and preclinical data have all pointed toward this pathway as an important regulator of tumor cell biology. Although early results from clinical trials that targeted the IGF1R showed some evidence of response...

  17. Optimal Therapeutic Strategy for Non-small Cell Lung Cancer with Mutated Epidermal Growth Factor Receptor

    Directory of Open Access Journals (Sweden)

    Zhong SHI

    2015-02-01

    Full Text Available Although epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs have been widely used in non-small cell lung cancer (NSCLC patients, it is still controversial about how to combine EGFR-TKI with chemotherapy and other targeted drugs. We have made a summary on the current therapeutic models of EGFR-TKI combined with chemotherapy/bevacizumab in this review and aimed to find the optimal therapeutic strategy for NSCLC patients with EGFR mutation.

  18. Signaling by Kit protein-tyrosine kinase--the stem cell factor receptor.

    Science.gov (United States)

    Roskoski, Robert

    2005-11-11

    Signaling by stem cell factor and Kit, its receptor, plays important roles in gametogenesis, hematopoiesis, mast cell development and function, and melanogenesis. Moreover, human and mouse embryonic stem cells express Kit transcripts. Stem cell factor exists as both a soluble and a membrane-bound glycoprotein while Kit is a receptor protein-tyrosine kinase. The complete absence of stem cell factor or Kit is lethal. Deficiencies of either produce defects in red and white blood cell production, hypopigmentation, and sterility. Gain-of-function mutations of Kit are associated with several human neoplasms including acute myelogenous leukemia, gastrointestinal stromal tumors, and mastocytomas. Kit consists of an extracellular domain, a transmembrane segment, a juxtamembrane segment, and a protein kinase domain that contains an insert of about 80 amino acid residues. Binding of stem cell factor to Kit results in receptor dimerization and activation of protein kinase activity. The activated receptor becomes autophosphorylated at tyrosine residues that serve as docking sites for signal transduction molecules containing SH2 domains. The adaptor protein APS, Src family kinases, and Shp2 tyrosyl phosphatase bind to phosphotyrosine 568. Shp1 tyrosyl phosphatase and the adaptor protein Shc bind to phosphotyrosine 570. C-terminal Src kinase homologous kinase and the adaptor Shc bind to both phosphotyrosines 568 and 570. These residues occur in the juxtamembrane segment of Kit. Three residues in the kinase insert domain are phosphorylated and attract the adaptor protein Grb2 (Tyr703), phosphatidylinositol 3-kinase (Tyr721), and phospholipase Cgamma (Tyr730). Phosphotyrosine 900 in the distal kinase domain binds phosphatidylinositol 3-kinase which in turn binds the adaptor protein Crk. Phosphotyrosine 936, also in the distal kinase domain, binds the adaptor proteins APS, Grb2, and Grb7. Kit has the potential to participate in multiple signal transduction pathways as a result of

  19. A sensitive electrochemiluminescence cytosensor for quantitative evaluation of epidermal growth factor receptor expressed on cell surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Yanjuan; Zhang, Shaolian; Wen, Qingqing; Huang, Hongxing; Yang, Peihui, E-mail: typh@jnu.edu.cn

    2015-06-30

    Highlights: • EGF-cytosensor was used for evaluating EGFR expression level on cell surfaces. • CdSQDs and EGF were coated on magnetic beads (MBs) for ECL-probe. • Good sensitivity was achieved due to the signal amplification of ECL-probe. - Abstract: A sensitive electrochemiluminescence (ECL) strategy for evaluating the epidermal growth factor receptor (EGFR) expression level on cell surfaces was designed by integrating the specific recognition of EGFR expressed on MCF-7 cell surfaces with an epidermal growth factor (EGF)-funtionalized CdS quantum dots (CdSQDs)-capped magnetic bead (MB) probe. The high sensitivity of ECL probe of EGF-funtionalized CdSQD-capped-MB was used for competitive recognition with EGFR expressed on cell surfaces with recombinant EGFR protein. The changes of ECL intensity depended on both the cell number and the expression level of EGFR receptor on cell surfaces. A wide linear response to cells ranging from 80 to 4 × 10{sup 6} cells mL{sup −1} with a detection limit of 40 cells mL{sup −1} was obtained. The EGF-cytosensor was used to evaluate EGFR expression levels on MCF-7 cells, and the average number of EGFR receptor on single MCF-7 cells was 1.35 × 10{sup 5} with the relative standard deviation of 4.3%. This strategy was further used for in-situ and real-time evaluating EGFR receptor expressed on cell surfaces in response to drugs stimulation at different concentration and incubation time. The proposed method provided potential applications in the detection of receptors on cancer cells and anticancer drugs screening.

  20. Hepatocyte growth factor enhances death receptor-induced apoptosis by up-regulating DR5

    International Nuclear Information System (INIS)

    Li, Yang; Fan, Xing; Goodwin, C Rory; Laterra, John; Xia, Shuli

    2008-01-01

    Hepatocyte growth factor (HGF) and its receptor c-MET are commonly expressed in malignant gliomas and embryonic neuroectodermal tumors including medulloblastoma and appear to play an important role in the growth and dissemination of these malignancies. Dependent on cell context and the involvement of specific downstream effectors, both pro- and anti-apoptotic effects of HGF have been reported. Human medulloblastoma cells were treated with HGF for 24–72 hours followed by death receptor ligand TRAIL (Tumor necrosis factor-related apoptosis-inducing ligand) for 24 hours. Cell death was measured by MTT and Annexin-V/PI flow cytometric analysis. Changes in expression levels of targets of interest were measured by Northern blot analysis, quantitative reverse transcription-PCR, Western blot analysis as well as immunoprecipitation. In this study, we show that HGF promotes medulloblastoma cell death induced by TRAIL. TRAIL alone triggered apoptosis in DAOY cells and death was enhanced by pre-treating the cells with HGF for 24–72 h prior to the addition of TRAIL. HGF (100 ng/ml) enhanced TRAIL (10 ng/ml) induced cell death by 36% (P < 0.001). No cell death was associated with HGF alone. Treating cells with PHA-665752, a specific c-Met receptor tyrosine kinase inhibitor, significantly abrogated the enhancement of TRAIL-induced cell death by HGF, indicating that its death promoting effect requires activation of its canonical receptor tyrosine kinase. Cell death induced by TRAIL+HGF was predominately apoptotic involving both extrinsic and intrinsic pathways as evidenced by the increased activation of caspase-3, 8, 9. Promotion of apoptosis by HGF occurred via the increased expression of the death receptor DR5 and enhanced formation of death-inducing signal complexes (DISC). Taken together, these and previous findings indicate that HGF:c-Met pathway either promotes or inhibits medulloblastoma cell death via pathway and context specific mechanisms

  1. Identification of fibroblast growth factor receptor 3 (FGFR3 as a protein receptor for botulinum neurotoxin serotype A (BoNT/A.

    Directory of Open Access Journals (Sweden)

    Birgitte P S Jacky

    Full Text Available Botulinum neurotoxin serotype A (BoNT/A causes transient muscle paralysis by entering motor nerve terminals (MNTs where it cleaves the SNARE protein Synaptosomal-associated protein 25 (SNAP25206 to yield SNAP25197. Cleavage of SNAP25 results in blockage of synaptic vesicle fusion and inhibition of the release of acetylcholine. The specific uptake of BoNT/A into pre-synaptic nerve terminals is a tightly controlled multistep process, involving a combination of high and low affinity receptors. Interestingly, the C-terminal binding domain region of BoNT/A, HC/A, is homologous to fibroblast growth factors (FGFs, making it a possible ligand for Fibroblast Growth Factor Receptors (FGFRs. Here we present data supporting the identification of Fibroblast Growth Factor Receptor 3 (FGFR3 as a high affinity receptor for BoNT/A in neuronal cells. HC/A binds with high affinity to the two extra-cellular loops of FGFR3 and acts similar to an agonist ligand for FGFR3, resulting in phosphorylation of the receptor. Native ligands for FGFR3; FGF1, FGF2, and FGF9 compete for binding to FGFR3 and block BoNT/A cellular uptake. These findings show that FGFR3 plays a pivotal role in the specific uptake of BoNT/A across the cell membrane being part of a larger receptor complex involving ganglioside- and protein-protein interactions.

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

    Science.gov (United States)

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

    2016-01-01

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

  3. Selective binding and oligomerization of the murine granulocyte colony-stimulating factor receptor by a low molecular weight, nonpeptidyl ligand.

    Science.gov (United States)

    Doyle, Michael L; Tian, Shin-Shay; Miller, Stephen G; Kessler, Linda; Baker, Audrey E; Brigham-Burke, Michael R; Dillon, Susan B; Duffy, Kevin J; Keenan, Richard M; Lehr, Ruth; Rosen, Jon; Schneeweis, Lumelle A; Trill, John; Young, Peter R; Luengo, Juan I; Lamb, Peter

    2003-03-14

    Granulocyte colony-stimulating factor regulates neutrophil production by binding to a specific receptor, the granulocyte colony-stimulating factor receptor, expressed on cells of the granulocytic lineage. Recombinant forms of granulocyte colony-stimulating factor are used clinically to treat neutropenias. As part of an effort to develop granulocyte colony-stimulating factor mimics with the potential for oral bioavailability, we previously identified a nonpeptidyl small molecule (SB-247464) that selectively activates murine granulocyte colony-stimulating factor signal transduction pathways and promotes neutrophil formation in vivo. To elucidate the mechanism of action of SB-247464, a series of cell-based and biochemical assays were performed. The activity of SB-247464 is strictly dependent on the presence of zinc ions. Titration microcalorimetry experiments using a soluble murine granulocyte colony-stimulating factor receptor construct show that SB-247464 binds to the extracellular domain of the receptor in a zinc ion-dependent manner. Analytical ultracentrifugation studies demonstrate that SB-247464 induces self-association of the N-terminal three-domain fragment in a manner that is consistent with dimerization. SB-247464 induces internalization of granulocyte colony-stimulating factor receptor on intact cells, consistent with a mechanism involving receptor oligomerization. These data show that small nonpeptidyl compounds are capable of selectively binding and inducing productive oligomerization of cytokine receptors.

  4. Thyroid hormone regulation of epidermal growth factor receptor levels in mouse mammary glands

    International Nuclear Information System (INIS)

    Vonderhaar, B.K.; Tang, E.; Lyster, R.R.; Nascimento, M.C.

    1986-01-01

    The specific binding of iodinated epidermal growth factor ([ 125 I]iodo-EGF) to membranes prepared from the mammary glands and spontaneous breast tumors of euthyroid and hypothyroid mice was measured in order to determine whether thyroid hormones regulate the EGF receptor levels in vivo. Membranes from hypothyroid mammary glands of mice at various developmental ages bound 50-65% less EGF than those of age-matched euthyroid controls. Treatment of hypothyroid mice with L-T4 before killing restored binding to the euthyroid control level. Spontaneous breast tumors arising in hypothyroid mice also bound 30-40% less EGF than tumors from euthyroid animals even after in vitro desaturation of the membranes of endogenous growth factors with 3 M MgCl2 treatment. The decrease in binding in hypothyroid membranes was due to a decrease in the number of binding sites, not to a change in affinity of the growth factor for its receptor, as determined by Scatchard analysis of the binding data. Both euthyroid and hypothyroid membranes bound EGF primarily to a single class of high affinity sites [dissociation constant (Kd) = 0.7-1.8 nM]. Euthyroid membranes bound 28.4 +/- (SE) 0.6 fmol/mg protein, whereas hypothyroid membranes bound 15.5 +/- 1.0 fmol/mg protein. These data indicate that EGF receptor levels in normal mammary glands and spontaneous breast tumors in mice are subject to regulation by thyroid status

  5. Regulation of platelet activating factor receptor coupled phosphoinositide-specific phospholipase C activity

    International Nuclear Information System (INIS)

    Morrison, W.J.

    1988-01-01

    The major objectives of this study were two-fold. The first was to establish whether binding of platelet activating factor (PAF) to its receptor was integral to the stimulation of polyphosphoinositide-specific phospholipase C (PLC) in rabbit platelets. The second was to determine regulatory features of this receptor-coupled mechanism. [ 3 H]PAF binding demonstrated two binding sites, a high affinity site with a inhibitory constant (Ki) of 2.65 nM and a low affinity site with a Ki of 0.80 μM. PAF receptor coupled activation of phosphoinositide-specific PLC was studied in platelets which were made refractory, by short term pretreatments, to either PAF or thrombin. Saponin-permeabilized rabbit platelets continue to regulate the mechanism(s) coupling PAF receptors to PLC stimulation. However, TRPγS and GDPβS, which affect guanine nucleotide regulatory protein functions, were unable to modulate the PLC activity to any appreciable extent as compared to PAF. The possible involvement of protein kinase C (PKC) activation in regulating PAF-stimulated PLC activity was studied in rabbit platelets pretreated with staurosporine followed by pretreatments with PAF or phorbol 12-myristate 13-acetate (PMA)

  6. Structural analysis of the receptors for granulocyte colony-stimulating factor on neutrophils

    International Nuclear Information System (INIS)

    Hanazono, Y.; Hosoi, T.; Kuwaki, T.; Matsuki, S.; Miyazono, K.; Miyagawa, K.; Takaku, F.

    1990-01-01

    We investigated granulocyte colony-stimulating factor (G-CSF) receptors on neutrophils from three patients with chronic myelogenous leukemia (CML) in the chronic phase, in comparison with four normal volunteers. Because we experienced some difficulties in radioiodinating intact recombinant human G-CSF, we developed a new derivative of human G-CSF termed YPY-G-CSF. It was easy to iodinate this protein using the lactoperoxidase method because of two additional tyrosine residues, and its radioactivity was higher than that previously reported. The biological activity of YPY-G-CSF as G-CSF was fully retained. Scatchard analysis demonstrated that CML neutrophils had a single class of binding sites (1400 +/- 685/cell) with a dissociation constant (Kd) of 245 +/- 66 pM. The number of sites and Kd value of CML neutrophils were not significantly different from those of normal neutrophils (p greater than 0.9). Cross-linking studies revealed two specifically labeled bands of [125I]YPY-G-CSF-receptor complexes with apparent molecular masses of 160 and 110 kd on both normal and CML neutrophils. This is the first report describing two receptor proteins on neutrophils. According to the analyses of the proteolytic process of these cross-linked complexes and proteolytic mapping, we assume that alternative splicing or processing from a single gene may generate two distinct receptor proteins that bind specifically to G-CSF but have different fates in intracellular metabolism

  7. Targeting of liposomes to cells bearing nerve growth factor receptors mediated by biotinylated NGF

    International Nuclear Information System (INIS)

    Rosenberg, M.B.

    1986-01-01

    Previous studies of liposome targeting have concentrated on immunological systems, the use of ligand-receptor interactions has received little attention. The protein hormone beta-nerve growth factor (NGF) was modified by biotinylation via carboxyl group substitution (C-bio-NGF) under reaction conditions that yielded an average of 3 biotin additions per NGF subunit. NGF was also biotinylated through amino group substitution to produce derivatives with ratios of 1, 2 and 4 biotin moieties per NGF subunit (N-bio-NGF). These derivatives were compared with native NGF for their ability to compete with 125 I-NGF for binding to NGF receptors on rat pheochromocytoma (PC 12) cells at 4 0 C. C-bio-NGF was as effective as native NGF in binding to NGF receptors, while N-bio-NGF containing 1 biotin per NGF subunit was only 28% as active in binding as native NGF. C-bio-NGF, but not N-bio-NGF, mediated the specific binding of 125 I-streptavidin to PC12 cells. Biocytin-NGF, a derivative of C-bio-NGF with an extended spacer chain, was also synthesized and retained full biological and receptor binding activities. C-bio-NGF and biocytin-NGF were as effective as native NGF in a bioassay involving induction of neurite outgrowth from PC12 cells

  8. Molecular Recognition of Corticotropin releasing Factor by Its G protein-coupled Receptor CRFR1

    Energy Technology Data Exchange (ETDEWEB)

    Pioszak, Augen A.; Parker, Naomi R.; Suino-Powell, Kelly; Xu, H. Eric (Van Andel)

    2009-01-15

    The bimolecular interaction between corticotropin-releasing factor (CRF), a neuropeptide, and its type 1 receptor (CRFR1), a class B G-protein-coupled receptor (GPCR), is crucial for activation of the hypothalamic-pituitary-adrenal axis in response to stress, and has been a target of intense drug design for the treatment of anxiety, depression, and related disorders. As a class B GPCR, CRFR1 contains an N-terminal extracellular domain (ECD) that provides the primary ligand binding determinants. Here we present three crystal structures of the human CRFR1 ECD, one in a ligand-free form and two in distinct CRF-bound states. The CRFR1 ECD adopts the alpha-beta-betaalpha fold observed for other class B GPCR ECDs, but the N-terminal alpha-helix is significantly shorter and does not contact CRF. CRF adopts a continuous alpha-helix that docks in a hydrophobic surface of the ECD that is distinct from the peptide-binding site of other class B GPCRs, thereby providing a basis for the specificity of ligand recognition between CRFR1 and other class B GPCRs. The binding of CRF is accompanied by clamp-like conformational changes of two loops of the receptor that anchor the CRF C terminus, including the C-terminal amide group. These structural studies provide a molecular framework for understanding peptide binding and specificity by the CRF receptors as well as a template for designing potent and selective CRFR1 antagonists for therapeutic applications.

  9. Imbalance of tumor necrosis factor receptors during progression in bovine leukemia virus infection

    International Nuclear Information System (INIS)

    Konnai, Satoru; Usui, Tatsufumi; Ikeda, Manabu; Kohara, Junko; Hirata, Toh-ichi; Okada, Kosuke; Ohashi, Kazuhiko; Onuma, Misao

    2005-01-01

    Previously, we found an up-regulation of tumor necrosis factor alpha (TNF)-α and an imbalance of TNF receptors in sheep experimentally infected with bovine leukemia virus (BLV). In order to investigate the different TNF-α-induced responses, in this study we examined the TNF-α-induced proliferative response and the expression levels of two distinct TNF receptors on peripheral blood mononuclear cells (PBMC) derived from BLV-uninfected cattle and BLV-infected cattle that were aleukemic (AL) or had persistent lymphocytosis (PL). The proliferative response of PBMC isolated from those cattle with PL in the presence of recombinant bovine TNF-α (rTNF-α) was significantly higher than those from AL cattle and uninfected cattle and the cells from PL cattle expressed significantly higher mRNA levels of TNF receptor type II (TNF-RII) than those from AL and BLV-uninfected cattle. No difference was found in TNF-RI mRNA levels. Most cells expressing TNF-RII in PL cattle were CD5 + or sIgM + cells and these cells showed resistance to TNF-α-induced apoptosis. Additionally, there were significant positive correlations between the changes in provirus load and TNF-RII mRNA levels, and TNF-α-induced proliferation and TNF-RII mRNA levels. These data suggest that imbalance in the expression of TNF receptors could at least in part contribute to the progression of lymphocytosis in BLV infection

  10. Expression of transforming growth factor alpha and epidermal growth factor receptor in rat lung neoplasms induced by plutonium-239

    International Nuclear Information System (INIS)

    Stegelmeier, B.L.; Gillett, N.A.; Hahn, F.F.; Kelly, G.; Rebar, A.H.

    1994-01-01

    Ninety-two rat lung proliferative lesions and neoplasms induced by inhaled 239 PuO 2 were evaluated for aberrant expression of transforming growth factor alpha (TGF-α) and epidermal growth factor receptor (EGFR). Expression of TGF-α protein, measured by immunohistochemistry, was higher in 94% of the squamous cell carcinomas and 87% of the foci of alveolar epithelial squamous metaplasia than that exhibited by the normal-appearing, adjacent lung parenchyma. In contrast, only 20% of adenocarcinomas and foci of epithelial hyperplasia expressed elevated levels of TGF-α. Many neoplasms expressing TGF-α also expressed excessive levels of EGFR mRNA. Southern and DNA slot blot analyses showed that the elevated EGFR expression was not due to amplification of the EGFR gene. These data suggest that increased amounts of TGF-α were early alterations in the progression of plutonium-induced squamous cell carcinoma, and these increases may occur in parallel with overexpression of the receptor for this growth factor. Together, these alterations create a potential autocrine loop for sustaining clonal expansion of cells initiated by high-LET radiation. 44 refs., 4 figs., 1 tab

  11. Tissue factor is an angiogenic-specific receptor for factor VII-targeted immunotherapy and photodynamic therapy.

    Science.gov (United States)

    Hu, Zhiwei; Cheng, Jijun; Xu, Jie; Ruf, Wolfram; Lockwood, Charles J

    2017-02-01

    Identification of target molecules specific for angiogenic vascular endothelial cells (VEC), the inner layer of pathological neovasculature, is critical for discovery and development of neovascular-targeting therapy for angiogenesis-dependent human diseases, notably cancer, macular degeneration and endometriosis, in which vascular endothelial growth factor (VEGF) plays a central pathophysiological role. Using VEGF-stimulated vascular endothelial cells (VECs) isolated from microvessels, venous and arterial blood vessels as in vitro angiogenic models and unstimulated VECs as a quiescent VEC model, we examined the expression of tissue factor (TF), a membrane-bound receptor on the angiogenic VEC models compared with quiescent VEC controls. We found that TF is specifically expressed on angiogenic VECs in a time-dependent manner in microvessels, venous and arterial vessels. TF-targeted therapeutic agents, including factor VII (fVII)-IgG1 Fc and fVII-conjugated photosensitizer, can selectively bind angiogenic VECs, but not the quiescent VECs. Moreover, fVII-targeted photodynamic therapy can selectively and completely eradicate angiogenic VECs. We conclude that TF is an angiogenic-specific receptor and the target molecule for fVII-targeted therapeutics. This study supports clinical trials of TF-targeted therapeutics for the treatment of angiogenesis-dependent diseases such as cancer, macular degeneration and endometriosis.

  12. Design and characteristics of cytotoxic fibroblast growth factor 1 conjugate for fibroblast growth factor receptor-targeted cancer therapy

    Directory of Open Access Journals (Sweden)

    Szlachcic A

    2016-08-01

    Full Text Available Anna Szlachcic, Malgorzata Zakrzewska, Michal Lobocki, Piotr Jakimowicz, Jacek Otlewski Department of Protein Engineering, Faculty of Biotechnology, University of Wroclaw, Wroclaw, Poland Abstract: Fibroblast growth factor receptors (FGFRs are attractive candidate cancer therapy targets as they are overexpressed in multiple types of tumors, such as breast, prostate, bladder, and lung cancer. In this study, a natural ligand of FGFR, an engineered variant of fibroblast growth factor 1 (FGF1V, was conjugated to a potent cytotoxic drug, monomethyl auristatin E (MMAE, and used as a targeting agent for cancer cells overexpressing FGFRs, similar to antibodies in antibody–drug conjugates. The FGF1V–valine–citrulline–MMAE conjugate showed a favorable stability profile, bound FGFRs on the cell surface specifically, and efficiently released the drug (MMAE upon cleavage by the lysosomal protease cathepsin B. Importantly, the conjugate showed a prominent cytotoxic effect toward cell lines expressing FGFR. FGF1V–vcMMAE was highly cytotoxic at concentrations even an order of magnitude lower than those found for free MMAE. This effect was FGFR-specific as cells lacking FGFR did not show any increased mortality. Keywords: fibroblast growth factor 1, FGF receptor, targeted cancer therapy, cytotoxic conjugates, FGFR-dependent cancer, MMAE, auristatin

  13. Antibody-induced activation of the epidermal growth factor receptor tyrosine kinase requires the presence of detergent

    NARCIS (Netherlands)

    Spaargaren, M.; Defize, L. H.; de Laat, S. W.; Boonstra, J.

    1990-01-01

    Activation of the epidermal growth factor receptor (EGF-R) tyrosine kinase was investigated in membrane preparations as well as intact A431 cells, using anti-EGF-R antibodies directed against extra- and intracellular receptor domains. In vitro assay conditions were mimicked on whole cells by a mild

  14. Blockade of epidermal growth factor receptors chemosensitizes breast cancer cells through up-regulation of Bnip3L

    NARCIS (Netherlands)

    Real, PJ; Benito, A; Cuevas, J; Berciano, MT; de Juan, A; Coffer, P; Gomez-Roman, J; Lafarga, M; Lopez-Vega, JM; Fernandez-Luna, JL

    2005-01-01

    Epidermal growth factor receptor-1 (EGFR) and EGFR-2 (HER2) have become major targets for cancer treatment. Blocking antibodies and small-molecule inhibitors are being used to silence the activity of these receptors in different tumors with varying efficacy. Thus, a better knowledge on the signaling

  15. Prognostic factors in advanced breast cancer: Race and receptor status are significant after development of metastasis.

    Science.gov (United States)

    Ren, Zhiyong; Li, Yufeng; Shen, Tiansheng; Hameed, Omar; Siegal, Gene P; Wei, Shi

    2016-01-01

    Prognostic factors are well established in early-stage breast cancer (BC), but less well-defined in advanced disease. We analyzed 323 BC patients who had distant relapse during follow-up from 1997 to 2010 to determine the significant clinicopathologic factors predicting survival outcomes. By univariate analysis, race, tumor grade, estrogen and progesterone receptors (ER/PR) and HER2 status were significantly associated with overall survival (OS) and post-metastasis survival (PMS). Applying a Cox regression model revealed that all these factors remained significant for PMS, while race, tumor grade and HER2 were independent factors for OS. Tumor grade was the only significant factor for metastasis-free survival by univariate and multivariate analyses. Our findings demonstrated that being Caucasian, hormonal receptor positive (HR+) and HER2 positive (HER2+) were all associated with a decreased hazard of death and that patients with HR+/HER2+ tumors had superior outcomes to those with HR+/HER2- disease. Further, PR status held a prognostic value over ER, thus reflecting the biologic mechanism of the importance of the functional ER pathway and the heterogeneity in the response to endocrine therapy. These observations indicate that the patients' genetic makeup and the intrinsic nature of the tumor principally govern BC progression and prognosticate the long-term outcomes in advanced disease. Copyright © 2015 Elsevier GmbH. All rights reserved.

  16. Differential role of tumor necrosis factor receptors in mouse brain inflammatory responses in cryolesion brain injury

    DEFF Research Database (Denmark)

    Quintana, Albert; Giralt, Mercedes; Rojas, Santiago

    2005-01-01

    Tumor necrosis factor-alpha (TNF-alpha) is one of the mediators dramatically increased after traumatic brain injury that leads to the activation, proliferation, and hypertrophy of mononuclear, phagocytic cells and gliosis. Eventually, TNF-alpha can induce both apoptosis and necrosis via intracell......Tumor necrosis factor-alpha (TNF-alpha) is one of the mediators dramatically increased after traumatic brain injury that leads to the activation, proliferation, and hypertrophy of mononuclear, phagocytic cells and gliosis. Eventually, TNF-alpha can induce both apoptosis and necrosis via...... intracellular signaling. This cytokine exerts its functions via interaction with two receptors: type-1 receptor (TNFR1) and type-2 receptor (TNFR2). In this work, the inflammatory response after a freeze injury (cryolesion) in the cortex was studied in wild-type (WT) animals and in mice lacking TNFR1 (TNFR1 KO...... signaling also affected the expression of apoptosis/cell death-related genes (Fas, Rip, p53), matrix metalloproteinases (MMP3, MMP9, MMP12), and their inhibitors (TIMP1), suggesting a role of TNFR1 in extracellular matrix remodeling after injury. However, GDNF, NGF, and BDNF expression were not affected...

  17. Expression, purification, and characterization of a diabody against the most important angiogenesis cell receptor: Vascular endothelial growth factor receptor 2

    Directory of Open Access Journals (Sweden)

    Mahdi Behdani

    2012-01-01

    Full Text Available Antibodies and their derivative fragments have long been used as tools in a variety of applications, in fundamental research work, biotechnology, diagnosis, and therapy. Camels produce single heavy-chain antibodies (VHH in addition to usual antibodies. These minimal-sized binders are very robust and bind the antigen with high affinity in a monomeric state. Vascular endothelial growth factor recepror-2 (VEGFR2 is an important tumor-associated receptor that blockade of its signaling can lead to the inhibition of neovascularization and tumor metastasis. Here, we describe the construction, expression, and purification VEGFR2-specific Diabody. Two variable fragments of a same camel anti-VEGFR2 antibody were linked together by the upper hinge segment of antibody to make a diabody. We showed the ability of diabody to recognition of VEGFR2 on the cell surface by FACS. Diabodies can be produced in the low-cost prokaryotic expression system, so they are suitable molecules for diagnostic and therapeutic issues.

  18. Purification of rat intestinal receptor for intrinsic factor-vitamin B12 complex

    International Nuclear Information System (INIS)

    Yamada, Shoji; Itaya, Harutaka; Nakazawa, Osamu; Fukuda, Morimichi.

    1977-01-01

    The intrinsic factor (IF) in a rat gastric mucosal extract was bound efficiently to vitamin B 12 -sepharose without significant change in its nature to produce IF-vitamin B 12 -sepharose. The purification of the intestinal receptor for the IF-vitamin B 12 complex was performed by the affinity chromatography using the IF-vitamin B 12 -sepharose as the affinity adsorbent. As a result of admixing the gastric mucosal extract sample with B 12 -sepharose while stirring for 4 hours, the adsorption was performed without any break through. Further, it was recognized that the B 12 -bound protein purified by the affinity chromatography using B 12 -sepharose was not much changed as compared with that before purification. Furthermore, it was recognized that IF-B 12 -sepharose was able to be made by binding IF with B 12 -sepharose which was made by coupling B 12 with the market-available AH-sepharose. The IF-B 12 -sepharose was washed with buffer solution, and then was loaded with the small intestine mucosal extract. Thereafter, the receptor was eluted by making di-valent cation inert with the buffer solution. After the removal of EDTA in the eluted solution by dialysis, the activity of the receptor was measured. 48.5% of the receptor activity loaded was recovered by the elution with EDTA. The specific activity of the receptor represented by the final amount of B 12 (pg)/the amount of protein (mg) in the purified substance was 335 folds of the original activity. (Iwakiri, K.)

  19. Platelet activating factor receptor binding plays a critical role in jet fuel-induced immune suppression

    International Nuclear Information System (INIS)

    Ramos, Gerardo; Kazimi, Nasser; Nghiem, Dat X.; Walterscheid, Jeffrey P.; Ullrich, Stephen E.

    2004-01-01

    Applying military jet fuel (JP-8) or commercial jet fuel (Jet-A) to the skin of mice suppresses the immune response in a dose-dependant manner. The release of biological response modifiers, particularly prostaglandin E 2 (PGE 2 ), is a critical step in activating immune suppression. Previous studies have shown that injecting selective cyclooxygenase-2 inhibitors into jet fuel-treated mice blocks immune suppression. Because the inflammatory phospholipid mediator, platelet-activating factor (PAF), up-regulates cyclooxygenase-2 production and PGE 2 synthesis by keratinocytes, we tested the hypothesis that PAF-receptor binding plays a role in jet fuel-induced immune suppression. Treating keratinocyte cultures with PAF and/or jet fuel (JP-8 and Jet-A) stimulates PGE 2 secretion. Jet fuel-induced PGE 2 production was suppressed by treating the keratinocytes with specific PAF-receptor antagonists. Injecting mice with PAF, or treating the skin of the mice with JP-8, or Jet-A, induced immune suppression. Jet fuel-induced immune suppression was blocked when the jet fuel-treated mice were injected with PAF-receptor antagonists before treatment. Jet fuel treatment has been reported to activate oxidative stress and treating the mice with anti-oxidants (Vitamins C, or E or beta-hydroxy toluene), before jet fuel application, interfered with immune suppression. These findings confirm previous studies showing that PAF-receptor binding can modulate immune function. Furthermore, they suggest that PAF-receptor binding may be an early event in the induction of immune suppression by immunotoxic environmental agents that target the skin

  20. Flow cytometric detection of growth factor receptors in autografts and analysis of growth factor concentrations in autologous stem cell transplantation: possible significance for platelet recovery

    DEFF Research Database (Denmark)

    Schiødt, I; Jensen, Charlotte Harken; Kjaersgaard, E

    2000-01-01

    In order to improve prediction of hematopoietic recovery, we conducted a pilot study, analyzing the significance of growth factor receptor expression in autografts as well as endogenous growth factor levels in blood before, during and after stem cell transplantation. Three early acting (stem cell......-CSF receptor positive, CD34+ progenitor cells were measured by flow cytometry in the leukapheresis product used for transplantation in a subgroup of 15 patients (NHL, n = 8, MM, n = 7). Three factors were identified as having a significant impact on platelet recovery. First, the level of Tpo in blood...... at the time of the nadir (day +7). Second, the percentage of re-infused thrombopoietin receptor positive progenitors and finally, the percentage of Flt3 receptor positive progenitors. On the other hand, none of the analyzed factors significantly predicted myeloid or erythroid recovery. These findings need...

  1. A Premature Termination of Human Epidermal Growth Factor Receptor Transcription in Escherichia coli

    Directory of Open Access Journals (Sweden)

    Jihene Elloumi-Mseddi

    2014-01-01

    Full Text Available Our success in producing an active epidermal growth factor receptor (EGFR tyrosine kinase in Escherichia coli encouraged us to express the full-length receptor in the same host. Despite its large size, we were successful at producing the full-length EGFR protein fused to glutathione S-transferase (GST that was detected by Western blot analysis. Moreover, we obtained a majoritarian truncated GST-EGFR form detectable by gel electrophoresis and Western blot. This truncated protein was purified and confirmed by MALDI-TOF/TOF analysis to belong to the N-terminal extracellular region of the EGFR fused to GST. Northern blot analysis showed two transcripts suggesting the occurrence of a transcriptional arrest.

  2. Recent Advances of Colony-Stimulating Factor-1 Receptor (CSF-1R) Kinase and Its Inhibitors.

    Science.gov (United States)

    El-Gamal, Mohammed I; Al-Ameen, Shahad K; Al-Koumi, Dania M; Hamad, Mawadda G; Jalal, Nouran A; Oh, Chang-Hyun

    2018-01-17

    Colony stimulation factor-1 receptor (CSF-1R), which is also known as FMS kinase, plays an important role in initiating inflammatory, cancer, and bone disorders when it is overstimulated by its ligand, CSF-1. Innate immunity, as well as macrophage differentiation and survival, are regulated by the stimulation of the CSF-1R. Another ligand, interlukin-34 (IL-34), was recently reported to activate the CSF-1R receptor in a different manner. The relationship between CSF-1R and microglia has been reviewed. Both CSF-1 antibodies and small molecule CSF-1R kinase inhibitors have now been tested in animal models and in humans. In this Perspective, we discuss the role of CSF-1 and IL-34 in producing cancer, bone disorders, and inflammation. We also review the newly discovered and improved small molecule kinase inhibitors and monoclonal antibodies that have shown potent activity toward CSF-1R, reported from 2012 until 2017.

  3. Mactosylceramide Prevents Glial Cell Overgrowth by Inhibiting Insulin and Fibroblast Growth Factor Receptor Signaling

    DEFF Research Database (Denmark)

    Gerdøe-Kristensen, Stine; Lund, Viktor K; Wandall, Hans H

    2017-01-01

    , in which the mannosyltransferase Egghead controls conversion of glucosylceramide (GlcCer) to mactosylceramide (MacCer). Lack of elongated GSL in egghead (egh) mutants causes overgrowth of subperineurial glia (SPG), largely due to aberrant activation of phosphatidylinositol 3-kinase (PI3K). However, to what...... of the Drosophila Insulin Receptor (InR) and the FGFR homolog Heartless (Htl) in wild type SPG, and is suppressed by inhibiting Htl and InR activity in egh. Knockdown of GlcCer synthase in the SPG fails to suppress glial overgrowth in egh nerves, and slightly promotes overgrowth in wild type, suggesting that RTK...... hyperactivation is caused by absence of MacCer and not by GlcCer accumulation. We conclude that an early product in GSL biosynthesis, MacCer, prevents inappropriate activation of Insulin and Fibroblast Growth Factor Receptors in Drosophila glia. This article is protected by copyright. All rights reserved....

  4. Detection and Quantification of Vascular Endothelial Growth Factor Receptor Tyrosine Kinases in Primary Human Endothelial Cells.

    Science.gov (United States)

    Fearnley, Gareth W; Wheatcroft, Stephen B; Ponnambalam, Sreenivasan

    2015-01-01

    Proteins differ widely in their pattern of expression depending on organism, tissue, and regulation in response to changing conditions. In the mammalian vasculature, the endothelium responds to vascular endothelial growth factors (VEGFs) via membrane-bound receptor tyrosine kinases (VEGFRs) to modulate many aspects of vascular physiology including vasculogenesis, angiogenesis, and blood pressure. Studies on VEGFR biology are thus dependent on detecting expression levels in different cell types and evaluating how changes in protein levels correlate with changing conditions including circulating VEGF levels. Here, we present a robust immunoblot-based protocol for detecting and quantifying VEGFRs in human endothelial cells. Using internal and external standards, we can rapidly evaluate receptor copy number and assess how this is altered in response to the cellular environment.

  5. Receptors for insulin-like growth factors I and II: autoradiographic localization in rat brain and comparison to receptors for insulin

    International Nuclear Information System (INIS)

    Lesniak, M.A.; Hill, J.M.; Kiess, W.; Rojeski, M.; Pert, C.B.; Roth, J.

    1988-01-01

    Receptors for insulin-like growth factor I (IGF-I) in rat brain were visualized using autoradiography with [125I]IGF-I. The binding of the labeled peptide was competed for fully by high concentrations of unlabeled IGF-I. At intermediate concentrations of unlabeled peptide the binding of [125I]IGF-I was competed for by unlabeled IGF-I more effectively than by IGF-II or insulin, which is typical of receptors for IGF-I. Essentially every brain section shows specific binding of IGF-I, and the pattern of binding of IGF-I to its receptors correlated well with the cytoarchitectonic structures. In parallel studies we showed that [125I]IGF-II was bound to tissue sections of rat brain and that the binding was competed for by an excess of unlabeled IGF-II. However, intermediate concentrations of unlabeled peptides gave inconclusive results. To confirm that the binding of [125I]IGF-II was to IGF-II receptors, we showed that antibodies specific for the IGF-II receptor inhibited the binding of labeled IGF-II. Furthermore, the binding of the antibody to regions of the brain section, visualized by the application of [125I]protein-A, gave patterns indistinguishable from those obtained with [125I]IGF-II alone. Again, the binding was very widely distributed throughout the central nervous system, and the patterns of distribution corresponded well to the underlying neural structures. Densitometric analysis of the receptors enabled us to compare the distribution of IGF-I receptors with that of IGF-II receptors as well as retrospectively with that of insulin receptors

  6. receptores

    Directory of Open Access Journals (Sweden)

    Salete Regina Daronco Benetti

    2006-01-01

    Full Text Available Se trata de un estudio etnográfico, que tuvo lo objetivo de interpretar el sistema de conocimiento y del significado atribuidos a la sangre referente a la transfusión sanguínea por los donadores y receptores de un banco de sangre. Para la colecta de las informaciones se observaron los participantes y la entrevista etnográfica se realizó el análisis de dominio, taxonómicos y temáticos. Los dominios culturales fueron: la sangre es vida: fuente de vida y alimento valioso; creencias religiosas: fuentes simbólicas de apoyos; donación sanguínea: un gesto colaborador que exige cuidarse, gratifica y trae felicidad; donación sanguínea: fuente simbólica de inseguridad; estar enfermo es una condición para realizar transfusión sanguínea; transfusión sanguínea: esperanza de vida; Creencias populares: transfusión sanguínea como riesgo para la salud; donadores de sangre: personas benditas; donar y recibir sangre: como significado de felicidad. Temática: “líquido precioso que origina, sostiene, modifica la vida, provoca miedo e inseguridad”.

  7. Advanced Research of Fibroblast Growth Factor Receptor 
in Non-small Cell Lung Cancer

    Directory of Open Access Journals (Sweden)

    Dan PU

    2013-11-01

    Full Text Available Lung cancer is severely threatening human health. In recent years, the treatment for lung adenocarcinoma has made a great progress, targeted therapy has been widely applied in clinic, and benefits amount of patients. However, in squamous cell lung cancer, the incidence of epidermal growth factor receptor (EGFR gene mutant and ALK fusion gene are low,and targeted therapy like Tarceva and crizotinib, can hardly work. Since the fibroblast growth factors (fibroblast growth factor, FGF pathway is considered to be related to tumor cell proliferation, metastasis and angiogenesis, more and more researches proved the amplification of fibroblast growth factor receptor (FGFR in squamous cell lung cancer. Experiments in vivo and in vitro found that blocking FGF pathway could reduce the proliferation of tumor cells and inhibit metastasis. The FGF pathway might be a new target for treatment of squamous cell lung cancer. This article reviews the effect of FGFR in tumorigenesis,as well as the prospect as a therapeutic target in non-small cell lung cancer.

  8. Stimulation of LDL receptor activity in Hep-G2 cells by a serum factor(s)

    International Nuclear Information System (INIS)

    Ellsworth, J.L.; Brown, C.; Cooper, A.D.

    1988-01-01

    The regulation of low-density lipoprotein (LDL) receptor activity in the human hepatoma cell line Hep-G2 by serum components was examined. Incubation of dense monolayers of Hep-G2 cells with fresh medium containing 10% fetal calf serum (FM) produced a time-dependent increase in LDL receptor activity. Uptake and degradation of 125I-LDL was stimulated two- to four-fold, as compared with that of Hep-G2 cells cultured in the same media in which they had been grown to confluence (CM); the maximal 125I-LDL uptake plus degradation increased from 0.2 microgram/mg cell protein/4 h to 0.8 microgram/mg cell protein/4 h. In addition, a two-fold increase in cell surface binding of 125I-LDL to Hep-G2 cells was observed when binding was measured at 4 degrees C. There was no change in the apparent Kd. The stimulation of LDL receptor activity was suppressed in a concentration-dependent manner by the addition of cholesterol, as LDL, to the cell medium. In contrast to the stimulation of LDL receptor activity, FM did not affect the uptake or degradation of 125I-asialoorosomucoid. Addition of FM increased the protein content per dish, and DNA synthesis was stimulated approximately five-fold, as measured by [3H]thymidine incorporation into DNA; however, the cell number did not change. Cellular cholesterol biosynthesis was also stimulated by FM; [14C]acetate incorporation into unesterified and esterified cholesterol was increased approximately five-fold. Incubation of Hep-G2 cells with high-density lipoproteins (200 micrograms protein/ml) or albumin (8.0 mg/ml) in the absence of the serum factor did not significantly increase the total processed 125I-LDL. Stimulation of LDL receptor activity was dependent on a heat-stable, nondialyzable serum component that eluted in the inclusion volume of a Sephadex G-75 column

  9. Cloning of human tumor necrosis factor (TNF) receptor cDNA and expression of recombinant soluble TNF-binding protein

    International Nuclear Information System (INIS)

    Gray, P.W.; Barrett, K.; Chantry, D.; Turner, M.; Feldmann, M.

    1990-01-01

    The cDNA for one of the receptors for human tumor necrosis factor (TNF) has been isolated. This cDNA encodes a protein of 455 amino acids that is divided into an extracellular domain of 171 residues and a cytoplasmic domain of 221 residues. The extracellular domain has been engineered for expression in mammalian cells, and this recombinant derivative binds TNFα with high affinity and inhibits its cytotoxic activity in vitro. The TNF receptor exhibits similarity with a family of cell surface proteins that includes the nerve growth factor receptor, the human B-cell surface antigen CD40, and the rat T-cell surface antigen OX40. The TNF receptor contains four cysteine-rich subdomains in the extracellular portion. Mammalian cells transfected with the entire TNF receptor cDNA bind radiolabeled TNFα with an affinity of 2.5 x 10 -9 M. This binding can be competitively inhibited with unlabeled TNFα or lymphotoxin (TNFβ)

  10. Novel targeted approaches to treating biliary tract cancer: the dual epidermal growth factor receptor and ErbB-2 tyrosine kinase inhibitor NVP-AEE788 is more efficient than the epidermal growth factor receptor inhibitors gefitinib and erlotinib.

    Science.gov (United States)

    Wiedmann, Marcus; Feisthammel, Jürgen; Blüthner, Thilo; Tannapfel, Andrea; Kamenz, Thomas; Kluge, Annett; Mössner, Joachim; Caca, Karel

    2006-08-01

    Aberrant activation of the epidermal growth factor receptor is frequently observed in neoplasia, notably in tumors of epithelial origin. Attempts to treat such tumors with epidermal growth factor receptor antagonists resulted in remarkable success in recent studies. Little is known, however, about the efficacy of this therapy in biliary tract cancer. Protein expression of epidermal growth factor receptor, ErbB-2, and vascular endothelial growth factor receptor-2 was assessed in seven human biliary tract cancer cell lines by immunoblotting. In addition, histological sections from 19 patients with extrahepatic cholangiocarcinoma were analyzed for epidermal growth factor receptor, ErbB-2 and vascular endothelial growth factor receptor-2 expression by immunohistochemistry. Moreover, we sequenced the cDNA products representing the entire epidermal growth factor receptor coding region of the seven cell lines, and searched for genomic epidermal growth factor receptor amplifications and polysomy by fluorescence in-situ hybridization. Cell growth inhibition by gefitinib erlotinib and NVP-AEE788 was studied in vitro by automated cell counting. In addition, the anti-tumoral effect of erlotinib and NVP-AEE788 was studied in a chimeric mouse model. The anti-tumoral drug mechanism in this model was assessed by MIB-1 antibody staining, terminal deoxynucleotidyl transfer-mediated dUTP nick end-labelling assay, von Willebrand factor staining, and immunoblotting for p-p42/44 (p-Erk1/2, p-MAPK) and p-AKT. Immunoblotting revealed expression of epidermal growth factor receptor, ErbB-2, and vascular endothelial growth factor receptor-2 in all biliary tract cancer cell lines. EGFR was detectable in six of 19 (32%) extrahepatic human cholangiocarcinoma tissue samples, ErbB-2 in 16 of 19 (84%), and vascular endothelial growth factor receptor-2 in nine of 19 (47%). Neither epidermal growth factor receptor mutations nor amplifications or polysomy were found in the seven biliary tract cancer

  11. Adenovirus E4-ORF1 Dysregulates Epidermal Growth Factor and Insulin/Insulin-Like Growth Factor Receptors To Mediate Constitutive Myc Expression

    OpenAIRE

    Kong, Kathleen; Kumar, Manish; Taruishi, Midori; Javier, Ronald T.

    2015-01-01

    The E4-ORF1 protein encoded by human adenovirus stimulates viral replication in human epithelial cells by binding and activating cellular phosphatidylinositol 3-kinase (PI3K) at the plasma membrane and cellular Myc in the nucleus. In this study, we showed that E4-ORF1 hijacks the tyrosine kinase activities of cellular epidermal growth factor receptor (EGFR) and insulin receptor (InsR)/insulin-like growth factor receptor 1 (IGF1R), as well as the lipid kinase activity of PI3K, to mediate const...

  12. Mammary tumors that become independent of the type I insulin-like growth factor receptor express elevated levels of platelet-derived growth factor receptors

    Directory of Open Access Journals (Sweden)

    Campbell Craig I

    2011-11-01

    Full Text Available Abstract Background Targeted therapies are becoming an essential part of breast cancer treatment and agents targeting the type I insulin-like growth factor receptor (IGF-IR are currently being investigated in clinical trials. One of the limitations of targeted therapies is the development of resistant variants and these variants typically present with unique gene expression patterns and characteristics compared to the original tumor. Results MTB-IGFIR transgenic mice, with inducible overexpression of the IGF-IR were used to model mammary tumors that develop resistance to IGF-IR targeting agents. IGF-IR independent mammary tumors, previously shown to possess characteristics associated with EMT, were found to express elevated levels of PDGFRα and PDGFRβ. Furthermore, these receptors were shown to be inversely expressed with the IGF-IR in this model. Using cell lines derived from IGF-IR-independent mammary tumors (from MTB-IGFIR mice, it was demonstrated that PDGFRα and to a lesser extent PDGFRβ was important for cell migration and invasion as RNAi knockdown of PDGFRα alone or PDGFRα and PDGFRβ in combination, significantly decreased tumor cell migration in Boyden chamber assays and suppressed cell migration in scratch wound assays. Somewhat surprisingly, concomitant knockdown of PDGFRα and PDGFRβ resulted in a modest increase in cell proliferation and a decrease in apoptosis. Conclusion During IGF-IR independence, PDGFRs are upregulated and function to enhance tumor cell motility. These results demonstrate a novel interaction between the IGF-IR and PDGFRs and highlight an important, therapeutically relevant pathway, for tumor cell migration and invasion.

  13. Self-renewal of human embryonic stem cells requires insulin-like growth factor-1 receptor and ERBB2 receptor signaling

    Science.gov (United States)

    Wang, Linlin; Schulz, Thomas C.; Sherrer, Eric S.; Dauphin, Derek S.; Shin, Soojung; Nelson, Angelique M.; Ware, Carol B.; Zhan, Mei; Song, Chao-Zhong; Chen, Xiaoji; Brimble, Sandii N.; McLean, Amanda; Galeano, Maria J.; Uhl, Elizabeth W.; D'Amour, Kevin A.; Chesnut, Jonathan D.; Rao, Mahendra S.

    2007-01-01

    Despite progress in developing defined conditions for human embryonic stem cell (hESC) cultures, little is known about the cell-surface receptors that are activated under conditions supportive of hESC self-renewal. A simultaneous interrogation of 42 receptor tyrosine kinases (RTKs) in hESCs following stimulation with mouse embryonic fibroblast (MEF) conditioned medium (CM) revealed rapid and prominent tyrosine phosphorylation of insulin receptor (IR) and insulin-like growth factor-1 receptor (IGF1R); less prominent tyrosine phosphorylation of epidermal growth factor receptor (EGFR) family members, including ERBB2 and ERBB3; and trace phosphorylation of fibroblast growth factor receptors. Intense IGF1R and IR phosphorylation occurred in the absence of MEF conditioning (NCM) and was attributable to high concentrations of insulin in the proprietary KnockOut Serum Replacer (KSR). Inhibition of IGF1R using a blocking antibody or lentivirus-delivered shRNA reduced hESC self-renewal and promoted differentiation, while disruption of ERBB2 signaling with the selective inhibitor AG825 severely inhibited hESC proliferation and promoted apoptosis. A simple defined medium containing an IGF1 analog, heregulin-1β (a ligand for ERBB2/ERBB3), fibroblast growth factor-2 (FGF2), and activin A supported long-term growth of multiple hESC lines. These studies identify previously unappreciated RTKs that support hESC proliferation and self-renewal, and provide a rationally designed medium for the growth and maintenance of pluripotent hESCs. PMID:17761519

  14. Involvement of macrophage migration inhibitory factor and its receptor (CD74) in human breast cancer.

    Science.gov (United States)

    Richard, Vincent; Kindt, Nadège; Decaestecker, Christine; Gabius, Hans-Joachim; Laurent, Guy; Noël, Jean-Christophe; Saussez, Sven

    2014-08-01

    Macrophage migration inhibitory factor (MIF) and its receptor CD74 appear to be involved in tumorigenesis. We evaluated, by immunohistochemical staining, the tissue expression and distribution of MIF and CD74 in serial sections of human invasive breast cancer tumor specimens. The serum MIF level was also determined in breast cancer patients. We showed a significant increase in serum MIF average levels in breast cancer patients compared to healthy individuals. MIF tissue expression, quantified by a modified Allred score, was strongly increased in carcinoma compared to tumor-free specimens, in the cancer cells and in the peritumoral stroma, with fibroblasts the most intensely stained. We did not find any significant correlation with histoprognostic factors, except for a significant inverse correlation between tumor size and MIF stromal positivity. CD74 staining was heterogeneous and significantly decreased in cancer cells but increased in the surrounding stroma, namely in lymphocytes, macrophages and vessel endothelium. There was no significant variation according to classical histoprognostic factors, except that CD74 stromal expression was significantly correlated with triple-negative receptor (TRN) status and the absence of estrogen receptors. In conclusion, our data support the concept of a functional role of MIF in human breast cancer. In addition to auto- and paracrine effects on cancer cells, MIF could contribute to shape the tumor microenvironment leading to immunomodulation and angiogenesis. Interfering with MIF effects in breast tumors in a therapeutic perspective remains an attractive but complex challenge. Level of co-expression of MIF and CD74 could be a surrogate marker for efficacy of anti-angiogenic drugs, particularly in TRN breast cancer tumor.

  15. Tumor necrosis factor receptor-associated factor 6 (TRAF6) participates in anti-lipopolysaccharide factors (ALFs) gene expression in mud crab.

    Science.gov (United States)

    Sun, Wan-Wei; Zhang, Xin-Xu; Wan, Wei-Song; Wang, Shu-Qi; Wen, Xiao-Bo; Zheng, Huai-Ping; Zhang, Yue-Ling; Li, Sheng-Kang

    2017-02-01

    Tumor necrosis factor receptor-associated factor 6 (TRAF6) is a key cytoplasm signal adaptor that mediates signals activated by tumor necrosis factor receptor (TNFR) superfamily and the Interleukin-1 receptor/Toll-like receptor (IL-1/TLR) superfamily. The full-length 2492 bp TRAF6 (Sp-TRAF6) from Scylla paramamosain contains 1800 bp of open reading frame (ORF) encoding 598 amino acids, including an N-terminal RING-type zinc finger, two TRAF-type zinc fingers and a conserved C-terminal meprin and TRAF homology (MATH) domain. Multiple alignment analysis shows that the putative amino acid sequence of Sp-TRAf6 has highest identity of 88% with Pt-TRAF6 from Portunus trituberculatus, while the similarity of Sp-TRAF6 with other crustacean sequences was 54-55%. RT-PCR analysis indicated that Sp-TRAF6 transcripts were predominantly expressed in the hepatopancreas and stomach, whereas it was barely detected in the heart and hemocytes in our study. Moreover, Sp-TRAF6 transcripts were significantly up-regulated after Vibrio parahemolyticus and LPS challenges. RNA interference assay was carried out used by siRNA to investigate the genes expression patterns regulated by Sp-TRAF6. The qRT-PCR results showed that silencing Sp-TRAF6 gene could inhibit SpALF1, SpALF2, SpALF5 and SpALF6 expression in hemocytes, while inhibit SpALF1, SpALF3, SpALF4, SpALF5 and SpALF6 expression in hepatopancreas. Taken together, the acute-phase response to immune challenges and the inhibition of SpALFs gene expression indicate that Sp-TRAF6 plays an important role in host defense against pathogen invasions via regulation of ALF gene expression in S. paramamosain. Copyright © 2016. Published by Elsevier Ltd.

  16. A chemokine-binding domain in the tumor necrosis factor receptor from variola (smallpox) virus.

    Science.gov (United States)

    Alejo, Alí; Ruiz-Argüello, M Begoña; Ho, Yin; Smith, Vincent P; Saraiva, Margarida; Alcami, Antonio

    2006-04-11

    Variola virus (VaV) is the causative agent of smallpox, one of the most devastating diseases encountered by man, that was eradicated in 1980. The deliberate release of VaV would have catastrophic consequences on global public health. However, the mechanisms that contribute to smallpox pathogenesis are poorly understood at the molecular level. The ability of viruses to evade the host defense mechanisms is an important determinant of viral pathogenesis. Here we show that the tumor necrosis factor receptor (TNFR) homologue CrmB encoded by VaV functions not only as a soluble decoy TNFR but also as a highly specific binding protein for several chemokines that mediate recruitment of immune cells to mucosal surfaces and the skin, sites of virus entry and viral replication at late stages of smallpox. CrmB binds chemokines through its C-terminal domain, which is unrelated to TNFRs, was named smallpox virus-encoded chemokine receptor (SECRET) domain and uncovers a family of poxvirus chemokine inhibitors. An active SECRET domain was found in another viral TNFR (CrmD) and three secreted proteins encoded by orthopoxviruses. These findings identify a previously undescribed chemokine-binding and inhibitory domain unrelated to host chemokine receptors and a mechanism of immune modulation in VaV that may influence smallpox pathogenesis.

  17. Orexin–Corticotropin-Releasing Factor Receptor Heteromers in the Ventral Tegmental Area as Targets for Cocaine

    Science.gov (United States)

    Navarro, Gemma; Quiroz, César; Moreno-Delgado, David; Sierakowiak, Adam; McDowell, Kimberly; Moreno, Estefanía; Rea, William; Cai, Ning-Sheng; Aguinaga, David; Howell, Lesley A.; Hausch, Felix; Cortés, Antonio; Mallol, Josefa; Casadó, Vicent; Lluís, Carme; Canela, Enric I.

    2015-01-01

    Release of the neuropeptides corticotropin-releasing factor (CRF) and orexin-A in the ventral tegmental area (VTA) play an important role in stress-induced cocaine-seeking behavior. We provide evidence for pharmacologically significant interactions between CRF and orexin-A that depend on oligomerization of CRF1 receptor (CRF1R) and orexin OX1 receptors (OX1R). CRF1R–OX1R heteromers are the conduits of a negative crosstalk between orexin-A and CRF as demonstrated in transfected cells and rat VTA, in which they significantly modulate dendritic dopamine release. The cocaine target σ1 receptor (σ1R) also associates with the CRF1R–OX1R heteromer. Cocaine binding to the σ1R–CRF1R–OX1R complex promotes a long-term disruption of the orexin-A–CRF negative crosstalk. Through this mechanism, cocaine sensitizes VTA cells to the excitatory effects of both CRF and orexin-A, thus providing a mechanism by which stress induces cocaine seeking. PMID:25926444

  18. Orexin-corticotropin-releasing factor receptor heteromers in the ventral tegmental area as targets for cocaine.

    Science.gov (United States)

    Navarro, Gemma; Quiroz, César; Moreno-Delgado, David; Sierakowiak, Adam; McDowell, Kimberly; Moreno, Estefanía; Rea, William; Cai, Ning-Sheng; Aguinaga, David; Howell, Lesley A; Hausch, Felix; Cortés, Antonio; Mallol, Josefa; Casadó, Vicent; Lluís, Carme; Canela, Enric I; Ferré, Sergi; McCormick, Peter J

    2015-04-29

    Release of the neuropeptides corticotropin-releasing factor (CRF) and orexin-A in the ventral tegmental area (VTA) play an important role in stress-induced cocaine-seeking behavior. We provide evidence for pharmacologically significant interactions between CRF and orexin-A that depend on oligomerization of CRF1 receptor (CRF1R) and orexin OX1 receptors (OX1R). CRF1R-OX1R heteromers are the conduits of a negative crosstalk between orexin-A and CRF as demonstrated in transfected cells and rat VTA, in which they significantly modulate dendritic dopamine release. The cocaine target σ1 receptor (σ1R) also associates with the CRF1R-OX1R heteromer. Cocaine binding to the σ1R-CRF1R-OX1R complex promotes a long-term disruption of the orexin-A-CRF negative crosstalk. Through this mechanism, cocaine sensitizes VTA cells to the excitatory effects of both CRF and orexin-A, thus providing a mechanism by which stress induces cocaine seeking. Copyright © 2015 the authors 0270-6474/15/356639-15$15.00/0.

  19. Receptors for insulin-like growth factor II (IGF-II) in the rat kidney glomerulus

    International Nuclear Information System (INIS)

    Haskell, J.F.; Pillion, D.J.; Meezan, E.

    1986-01-01

    Renal glomeruli were isolated by a technique involving renal perfusion with a solution containing magnetic iron oxide particles, followed by homogenization, sieving and isolation over a strong magnet. Isolated glomeruli were treated with 1% Triton X-100 to solubilize plasma membrane components while insoluble basement membrane components were removed by centrifugation. [ 125 I]Insulin-like growth factor-II (IGF-II) binding to this preparation was competitively inhibited by increasing amounts of unlabelled IGF-II, with 50% inhibition of binding observed at an IGF-II concentration of 1 ng/ml. [ 125 I]IGF-II was covalently cross-linked to its receptor with disuccinimidyl suberate in two tissues known to contain IGF-II receptors, the rat chondrosarcoma chondrocyte and the rat kidney tubule, as well as in rat renal glomeruli. In all three cases, a specific high-molecular weight (Mr = 255,000) band could be identified on autoradiograms of dodecyl sulfate polyacrylamide gels. These results indicate that the rat glomerulus contains a high-affinity receptor for IGF-II. This finding is consistent with the hypothesis that IGF-II plays a role in glomerular growth and differentiation

  20. Nuclear functions and subcellular trafficking mechanisms of the epidermal growth factor receptor family

    Science.gov (United States)

    2012-01-01

    Accumulating evidence suggests that various diseases, including many types of cancer, result from alteration of subcellular protein localization and compartmentalization. Therefore, it is worthwhile to expand our knowledge in subcellular trafficking of proteins, such as epidermal growth factor receptor (EGFR) and ErbB-2 of the receptor tyrosine kinases, which are highly expressed and activated in human malignancies and frequently correlated with poor prognosis. The well-characterized trafficking of cell surface EGFR is routed, via endocytosis and endosomal sorting, to either the lysosomes for degradation or back to the plasma membrane for recycling. A novel nuclear mode of EGFR signaling pathway has been gradually deciphered in which EGFR is shuttled from the cell surface to the nucleus after endocytosis, and there, it acts as a transcriptional regulator, transmits signals, and is involved in multiple biological functions, including cell proliferation, tumor progression, DNA repair and replication, and chemo- and radio-resistance. Internalized EGFR can also be transported from the cell surface to several intracellular compartments, such as the Golgi apparatus, the endoplasmic reticulum, and the mitochondria, in addition to the nucleus. In this review, we will summarize the functions of nuclear EGFR family and the potential pathways by which EGFR is trafficked from the cell surface to a variety of cellular organelles. A better understanding of the molecular mechanism of EGFR trafficking will shed light on both the receptor biology and potential therapeutic targets of anti-EGFR therapies for clinical application. PMID:22520625

  1. Specific, high affinity receptors for insulin-like growth factor II in the rat kidney glomerulus

    International Nuclear Information System (INIS)

    Haskell, J.F.; Pillion, D.J.; Meezan, E.

    1988-01-01

    Rat renal glomeruli were isolated by a technique involving kidney perfusion with a solution containing magnetic iron oxide particles, followed by homogenization, sieving, and concentration over a strong magnet. Isolated glomeruli were treated with 1% Triton X-100 to solubilize plasma membrane components, while insoluble basement membrane components were removed by centrifugation. [ 125 I]Insulin-like growth factor II (IGF-II) binding to this preparation was competitively inhibited by increasing amounts of unlabeled IGF-II, with 50% inhibition at an IGF-II concentration of 1 ng/ml. [ 125 I]IGF-II was covalently cross-linked with disuccinimidyl suberate to its receptor in rat renal glomeruli and a specific high mol wt (255,000) band could be identified on autoradiograms of dodecyl sulfate-polyacrylamide gels. [ 125 I]IGF-II binding and cross-linking to this band was inhibited by a polyclonal antibody against the type II IGF receptor. These results demonstrate for the first time that the isolated rat renal glomerulus contains a high affinity receptor for IGF-II

  2. A chemokine-binding domain in the tumor necrosis factor receptor from variola (smallpox) virus

    Science.gov (United States)

    Alejo, Alí; Ruiz-Argüello, M. Begoña; Ho, Yin; Smith, Vincent P.; Saraiva, Margarida; Alcami, Antonio

    2006-01-01

    Variola virus (VaV) is the causative agent of smallpox, one of the most devastating diseases encountered by man, that was eradicated in 1980. The deliberate release of VaV would have catastrophic consequences on global public health. However, the mechanisms that contribute to smallpox pathogenesis are poorly understood at the molecular level. The ability of viruses to evade the host defense mechanisms is an important determinant of viral pathogenesis. Here we show that the tumor necrosis factor receptor (TNFR) homologue CrmB encoded by VaV functions not only as a soluble decoy TNFR but also as a highly specific binding protein for several chemokines that mediate recruitment of immune cells to mucosal surfaces and the skin, sites of virus entry and viral replication at late stages of smallpox. CrmB binds chemokines through its C-terminal domain, which is unrelated to TNFRs, was named smallpox virus-encoded chemokine receptor (SECRET) domain and uncovers a family of poxvirus chemokine inhibitors. An active SECRET domain was found in another viral TNFR (CrmD) and three secreted proteins encoded by orthopoxviruses. These findings identify a previously undescribed chemokine-binding and inhibitory domain unrelated to host chemokine receptors and a mechanism of immune modulation in VaV that may influence smallpox pathogenesis. PMID:16581912

  3. Receptor activator of nuclear factor kappa B ligand and osteoprotegerin levels in gingival crevicular fluid

    Science.gov (United States)

    Sarlati, Fatemeh; Sattari, Mandana; Razzaghi, Shilan; Nasiri, Malihe

    2012-01-01

    Background: Osteoclastogenesis is coordinated by the interaction of three members of the tumor necrosis factor (TNF) superfamily: Osteoprotegerin (OPG)/receptor activator of nuclear factor kappa B ligand (RANKL)/receptor activator of nuclear factor kappa B (RANK). The aim of this study was to investigate RANKL and OPG levels, and their relative ratio in gingival crevicular fluid (GCF) of patients with chronic and aggressive periodontitis, as well as healthy controls. Materials and Methods: In this analytical study, GCF was obtained from healthy (n = 10), mild chronic periodontitis (n = 18), moderate chronic periodontitis (n = 18), severe chronic periodontitis (n = 20), and generalized aggressive periodontitis (n = 20) subjects. RANKL and OPG concentrations were measured by enzyme-linked immunosorbent assay. Statistical tests used were Kruskal–Wallis test, Mann–Whitney U rank sum test, and Spearman's rank correlation analysis. The level of statistical significance was set at P chronic periodontitis (mild, moderate, severe), and aggressive periodontitis (P = 0.41). There was statistically significant correlation between the concentration of sRANKL and Clinical Attachment Level (CAL) in moderate chronic periodontitis patients (R = 0.48, P = 0.04). There was also negative correlation between OPG concentration and CAL in moderate chronic periodontitis patients, although not significant (R = −0.13). Conclusion: RANKL was prominent in periodontitis sites, especially in moderate periodontitis patients, whereas OPG was not detectable in some diseased sites with bleeding on probing, supporting the role of these two molecules in the bone loss developed in this disease. PMID:23559954

  4. Involvement of growth factors and their receptors in radon-induced rat lung tumors

    International Nuclear Information System (INIS)

    Leung, F.C.; Dagle, G.E.; Cross, F.T.

    1992-01-01

    In this paper we examine the role of growth factors (GF) and their receptors (GFR) in radon-induced rat lung tumors. Inhalation exposure of radon and its daughters induced lung tumors in rats, but the molecule/cellular mechanisms are not known. Recent evidence suggests that GF/GFR play a critical role in the growth and development of lung cancer in humans and animals. We have developed immunocytochemical methods for identifying sites of production and action of GF/GFR at the cellular level; for example, the avidin-biotin horseradish peroxidase technique. In radon-induced rat epidermoid carcinomas, epidermal growth factor (EGF), EGF-receptors (EGF-R), transforming growth factor alpha (TGF-α), and bombesin were found to be abnormally expressed. These abnormal expressions, mainly associated with epidermoid carcinomas of the lung, were not found in any other lung tumor types. Our data suggest that EGF, EGF-R, TGF-α, and bombesin are involved in radon oncogenesis in rat lungs, especially in epidermoid carcinomas, possibly through the autocrine/paracrine pathway

  5. Eps15 is recruited to the plasma membrane upon epidermal growth factor receptor activation and localizes to components of the endocytic pathway during receptor internalization

    DEFF Research Database (Denmark)

    Torrisi, M R; Lotti, L V; Belleudi, F

    1999-01-01

    Eps15 is a substrate for the tyrosine kinase of the epidermal growth factor receptor (EGFR) and is characterized by the presence of a novel protein:protein interaction domain, the EH domain. Eps15 also stably binds the clathrin adaptor protein complex AP-2. Previous work demonstrated an essential...

  6. Divergent effects of insulin-like growth factor-1 receptor expression on prognosis of estrogen receptor positive versus triple negative invasive ductal breast carcinoma

    NARCIS (Netherlands)

    Hartog, Hermien; Horlings, Hugo M; van der Vegt, Bert; Kreike, Bas; Ajouaou, Abderrahim; van de Vijver, Marc J; Boezen, Hendrika; de Bock, Geertruida H; van der Graaf, Wilhelmina; Wesseling, Jelle

    2011-01-01

    The insulin-like growth factor type 1 receptor (IGF1R) is involved in progression of breast cancer and resistance to systemic treatment. Targeting IGF1R signaling may, therefore, be beneficial in systemic treatment. We report the effect of IGF1R expression on prognosis in invasive ductal breast

  7. P55 tumour necrosis factor receptor in bone marrow-derived cells promotes atherosclerosis development in low-density lipoprotein receptor knock-out mice

    NARCIS (Netherlands)

    Xanthoulea, Sofia; Gijbels, Marion J. J.; van der Made, Ingeborg; Mujcic, Hilda; Thelen, Melanie; Vergouwe, Monique N.; Ambagts, Matheus H. C.; Hofker, Marten H.; de Winther, Menno P. J.

    2008-01-01

    Tumour necrosis factor (TNF) is a pivotal pro-inflammatory cytokine with a clear pathogenic role in many chronic inflammatory diseases, and p55 TNF receptor (TNFR) mediates the majority of TNF responses. The aim of the current study was to investigate the role of p55 TNFR expression in bone

  8. The aryl hydrocarbon receptor and estrogen receptor alpha differentially modulate nuclear factor erythroid-2-related factor 2 transactivation in MCF-7 breast cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Lo, Raymond; Matthews, Jason, E-mail: jason.matthews@utoronto.ca

    2013-07-15

    Nuclear factor erythroid-2-related factor 2 (NRF2; NFE2L2) plays an important role in mediating cellular protection against reactive oxygen species. NRF2 signaling is positively modulated by the aryl hydrocarbon receptor (AHR) but inhibited by estrogen receptor alpha (ERα). In this study we investigated the crosstalk among NRF2, AHR and ERα in MCF-7 breast cancer cells treated with the NRF2 activator sulforaphane (SFN), a dual AHR and ERα activator, 3,3′-diindolylmethane (DIM), 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) or 17β-estradiol (E2). SFN-dependent increases in NADPH-dependent oxidoreductase 1 (NQO1) and heme oxygenase I (HMOX1) mRNA levels were significantly reduced after co-treatment with E2. E2-dependent repression of NQO1 and HMOX1 was associated with increased ERα but reduced p300 recruitment and reduced histone H3 acetylation at both genes. In contrast, DIM + SFN or TCDD + SFN induced NQO1 and HMOX1 mRNA expression to levels higher than SFN alone, which was prevented by RNAi-mediated knockdown of AHR. DIM + SFN but not TCDD + SFN also induced recruitment of ERα to NQO1 and HMOX1. However, the presence of AHR at NQO1 and HMOX1 restored p300 recruitment and histone H3 acetylation, thereby reversing the ERα-dependent repression of NRF2. Taken together, our study provides further evidence of functional interplay among NRF2, AHR and ERα signaling pathways through altered p300 recruitment to NRF2-regulated target genes. - Highlights: • We examined crosstalk among ERα, AHR, and NRF2 in MCF-7 breast cancer cells. • AHR enhanced the mRNA expression levels of two NRF2 target genes – HMOX1 and NQO1. • ERα repressed HMOX1 and NQO1 expression via decreased histone acetylation. • AHR prevented ERα-dependent repression of HMOX1 and NQO1.

  9. Lack of Evidence for a Direct Interaction of Progranulin and Tumor Necrosis Factor Receptor-1 and Tumor Necrosis Factor Receptor-2 From Cellular Binding Studies

    Directory of Open Access Journals (Sweden)

    Isabell Lang

    2018-04-01

    Full Text Available Progranulin (PGRN is a secreted anti-inflammatory protein which can be processed by neutrophil proteases to various granulins. It has been reported that at least a significant portion of the anti-inflammatory effects of PGRN is due to direct high affinity binding to tumor necrosis factor receptor-1 (TNFR1 and TNFR2 and inhibition of tumor necrosis factor (TNF-induced TNFR1/2 signaling. Two studies failed to reproduce the interaction of TNFR1 and TNFR2 with PGRN, but follow up reports speculated that this was due to varying experimental circumstances and/or the use of PGRN from different sources. However, even under consideration of these speculations, there is still a striking discrepancy in the literature between the concentrations of PGRN needed to inhibit TNF signaling and the concentrations required to block TNF binding to TNFR1 and TNFR2. While signaling events induced by 0.2–2 nM of TNF have been efficiently inhibited by low, near to equimolar concentrations (0.5–2.5 nM of PGRN in various studies, the reported inhibitory effects of PGRN on TNF-binding to TNFR1/2 required a huge excess of PGRN (100–1,000-fold. Therefore, we investigated the effect of PGRN on TNF binding to TNFR1 and TNFR2 in highly sensitive cellular binding studies. Unlabeled TNF inhibited >95% of the specific binding of a Gaussia princeps luciferase (GpL fusion protein of TNF to TNFR1 and TNFR2 and blocked binding of soluble GpL fusion proteins of TNFR1 and TNFR2 to membrane TNF expressing cells to >95%, too. Purified PGRN, however, showed in both assays no effect on TNF–TNFR1/2 interaction even when applied in huge excess. To rule out that tags and purification- or storage-related effects compromise the potential ability of PGRN to bind TNF receptors, we directly co-expressed PGRN, and as control TNF, in TNFR1- and TNFR2-expressing cells and looked for binding of GpL-TNF. While expression of TNF strongly inhibited binding of GpL-TNF to TNFR1/2, co

  10. The aryl hydrocarbon receptor and estrogen receptor alpha differentially modulate nuclear factor erythroid-2-related factor 2 transactivation in MCF-7 breast cancer cells

    International Nuclear Information System (INIS)

    Lo, Raymond; Matthews, Jason

    2013-01-01

    Nuclear factor erythroid-2-related factor 2 (NRF2; NFE2L2) plays an important role in mediating cellular protection against reactive oxygen species. NRF2 signaling is positively modulated by the aryl hydrocarbon receptor (AHR) but inhibited by estrogen receptor alpha (ERα). In this study we investigated the crosstalk among NRF2, AHR and ERα in MCF-7 breast cancer cells treated with the NRF2 activator sulforaphane (SFN), a dual AHR and ERα activator, 3,3′-diindolylmethane (DIM), 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) or 17β-estradiol (E2). SFN-dependent increases in NADPH-dependent oxidoreductase 1 (NQO1) and heme oxygenase I (HMOX1) mRNA levels were significantly reduced after co-treatment with E2. E2-dependent repression of NQO1 and HMOX1 was associated with increased ERα but reduced p300 recruitment and reduced histone H3 acetylation at both genes. In contrast, DIM + SFN or TCDD + SFN induced NQO1 and HMOX1 mRNA expression to levels higher than SFN alone, which was prevented by RNAi-mediated knockdown of AHR. DIM + SFN but not TCDD + SFN also induced recruitment of ERα to NQO1 and HMOX1. However, the presence of AHR at NQO1 and HMOX1 restored p300 recruitment and histone H3 acetylation, thereby reversing the ERα-dependent repression of NRF2. Taken together, our study provides further evidence of functional interplay among NRF2, AHR and ERα signaling pathways through altered p300 recruitment to NRF2-regulated target genes. - Highlights: • We examined crosstalk among ERα, AHR, and NRF2 in MCF-7 breast cancer cells. • AHR enhanced the mRNA expression levels of two NRF2 target genes – HMOX1 and NQO1. • ERα repressed HMOX1 and NQO1 expression via decreased histone acetylation. • AHR prevented ERα-dependent repression of HMOX1 and NQO1.

  11. Co-inhibition of epidermal growth factor receptor and insulin-like growth factor receptor 1 enhances radiosensitivity in human breast cancer cells

    International Nuclear Information System (INIS)

    Li, Ping; Veldwijk, Marlon R; Zhang, Qing; Li, Zhao-bin; Xu, Wen-cai; Fu, Shen

    2013-01-01

    Over-expression of epidermal growth factor receptor (EGFR) or insulin-like growth factor-1 receptor (IGF-1R) have been shown to closely correlate with radioresistance of breast cancer cells. This study aimed to investigate the impact of co-inhibition of EGFR and IGF-1R on the radiosensitivity of two breast cancer cells with different profiles of EGFR and IGF-1R expression. The MCF-7 (EGFR +/−, IGF-1R +++) and MDA-MB-468 (EGFR +++, IGF-1R +++) breast cancer cell lines were used. Radiosensitizing effects were determined by colony formation assay. Apoptosis and cell cycle distribution were measured by flow cytometry. Phospho-Akt and phospho-Erk1/2 were quantified by western blot. In vivo studies were conducted using MDA-MB-468 cells xenografted in nu/nu mice. In MDA-MB-468 cells, the inhibition of IGF-1R upregulated the p-EGFR expression. Either EGFR (AG1478) or IGF-1R inhibitor (AG1024) radiosensitized MDA-MB-468 cells. In MCF-7 cells, radiosensitivity was enhanced by AG1024, but not by AG1478. Synergistical radiosensitizing effect was observed by co-inhibition of EGFR and IGF-1R only in MDA-MB-468 cells with a DMF 10% of 1.90. The co-inhibition plus irradiation significantly induced more apoptosis and arrested the cells at G0/G1 phase in MDA-MB-468 cells. Only co-inhibition of EGFR and IGF-1R synergistically diminished the expression of p-Akt and p-Erk1/2 in MDA-MB-468 cells. In vivo studies further verified the radiosensitizing effects by co-inhibition of both pathways in a MDA-MB-468 xenograft model. Our data suggested that co-inhibition of EGFR and IGF-1R synergistically radiosensitized breast cancer cells with both EGFR and IGF-1R high expression. The approach may have an important therapeutic implication in the treatment of breast cancer patients with high expression of EGFR and IGF-1R

  12. Regulation of the ligand-dependent activation of the epidermal growth factor receptor by calmodulin

    DEFF Research Database (Denmark)

    Li, Hongbing; Panina, Svetlana; Kaur, Amandeep

    2012-01-01

    Calmodulin (CaM) is the major component of calcium signaling pathways mediating the action of various effectors. Transient increases in the intracellular calcium level triggered by a variety of stimuli lead to the formation of Ca2+/CaM complexes, which interact with and activate target proteins....... In the present study the role of Ca2+/CaM in the regulation of the ligand-dependent activation of the epidermal growth factor receptor (EGFR) has been examined in living cells. We show that addition of different cell permeable CaM antagonists to cultured cells or loading cells with a Ca2+ chelator inhibited...

  13. Strong association of epidermal growth factor receptor status with breast cancer FDG uptake

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Joohee; Moon, Seung Hwan; Hyun, Seung Hyup; Cho, Young Seok; Choi, Joon Young; Kim, Byung-Tae; Lee, Kyung-Han [Sungkyunkwan University School of Medicine, Department of Nuclear Medicine, Samsung Medical Center, Seoul (Korea, Republic of); Lee, Eun Jeong [Seoul Medical Center, Department of Nuclear Medicine, Seoul (Korea, Republic of); Kim, Seokhwi [Sungkyunkwan University School of Medicine, Department of Pathology, Samsung Medical Center, Seoul (Korea, Republic of)

    2017-08-15

    Imaging tumor FDG uptake could complement breast cancer biomarkers of risk and treatment response. Although breast cancer FDG uptake is reputedly influenced by major biomarker states, the role of epidermal growth factor receptor (EGFR) expression remains largely unexplored. This is a retrospective study that included 499 patients with primary breast cancer at initial presentation. Tumor FDG uptake was measured on pretreatment PET/CT as maximum standardized uptake value (SUVmax), and biomarkers were assessed by immunohistochemistry of tumor tissue. Regression analysis was performed for predictors of high tumor FDG uptake (SUVmax ≥ 8.6). SUVmax was higher in ER- (36.5%; 11.2 ± 6.0 vs. 8.3 ± 5.3), PR- (42.3%; 10.9 ± 6.0 vs. 8.2 ± 5.2), and triple-negative tumors (19.8%; 12.0 ± 6.9 vs. 8.7 ± 5.2; all p < 0.0001). EGFR expression (28.5%) was more frequent in ER-, PR-, triple-negative, cytokeratin 5/6 (CK5/6) + and mutant P53 (mP53) + tumors (all p < 0.0001). EGFR+ was associated with higher SUVmax among all tumors (11.9 ± 6.0 vs. 8.3 ± 5.3), ER- tumors (p < 0.0001), PR- and + tumors (p < 0.0001 and 0.027), hormone receptor- and + tumors (p < 0.0001 and 0.004), human epidermal growth factor receptor 2 (HER2)- and + tumors (p < 0.0001 and 0.006), non-triple negative tumors (p < 0.0001), CK5/6- and + tumors (p = 0.021 and <0.0001), and mP53- and + tumors (p < 0.0001 and 0.008). Tumors had high FDG uptake in 73.2% of EGFR+ and 40.6% of EGFR- tumors. On regression analysis, significant multivariate predictors of high tumor FDG uptake were large size, EGFR+ and CK5/6+ for the entire subjects, and EGFR+ and CK5/6+ for ER- and hormone receptor negative subgroups. High FDG uptake was able to sub-stratify EGFR+ tumors that were more likely to be ER- and CK5/6+, and EGFR- tumors more likely to be mP53 +. Primary breast tumor FDG uptake is strongly influenced by EGFR status beyond that by other major biomarkers including hormone receptor and HER2 status, and EGFR

  14. Rab GTPases Regulate Endothelial Cell Protein C Receptor-Mediated Endocytosis and Trafficking of Factor VIIa

    Science.gov (United States)

    Nayak, Ramesh C.; Keshava, Shiva; Esmon, Charles T.; Pendurthi, Usha R.; Rao, L. Vijaya Mohan

    2013-01-01

    Recent studies have established that factor VIIa (FVIIa) binds to the endothelial cell protein C receptor (EPCR). FVIIa binding to EPCR may promote the endocytosis of this receptor/ligand complex. Rab GTPases are known to play a crucial role in the endocytic and exocytic pathways of receptors or receptor/ligand complexes. The present study was undertaken to investigate the role of Rab GTPases in the intracellular trafficking of EPCR and FVIIa. CHO-EPCR cells and human umbilical vein endothelial cells (HUVEC) were transduced with recombinant adenoviral vectors to express wild-type, constitutively active, or dominant negative mutant of various Rab GTPases. Cells were exposed to FVIIa conjugated with AF488 fluorescent probe (AF488-FVIIa), and intracellular trafficking of FVIIa, EPCR, and Rab proteins was evaluated by immunofluorescence confocal microscopy. In cells expressing wild-type or constitutively active Rab4A, internalized AF488-FVIIa accumulated in early/sorting endosomes and its entry into the recycling endosomal compartment (REC) was inhibited. Expression of constitutively active Rab5A induced large endosomal structures beneath the plasma membrane where EPCR and FVIIa accumulated. Dominant negative Rab5A inhibited the endocytosis of EPCR-FVIIa. Expression of constitutively active Rab11 resulted in retention of accumulated AF488-FVIIa in the REC, whereas expression of a dominant negative form of Rab11 led to accumulation of internalized FVIIa in the cytoplasm and prevented entry of internalized FVIIa into the REC. Expression of dominant negative Rab11 also inhibited the transport of FVIIa across the endothelium. Overall our data show that Rab GTPases regulate the internalization and intracellular trafficking of EPCR-FVIIa. PMID:23555015

  15. Expression of Vascular Endothelial Growth Factor Receptors in Benign Vascular Lesions of the Orbit: A Case Series.

    Science.gov (United States)

    Atchison, Elizabeth A; Garrity, James A; Castillo, Francisco; Engman, Steven J; Couch, Steven M; Salomão, Diva R

    2016-01-01

    Vascular lesions of the orbit, although not malignant, can cause morbidity because of their location near critical structures in the orbit. For the same reason, they can be challenging to remove surgically. Anti-vascular endothelial growth factor (VEGF) drugs are increasingly being used to treat diseases with prominent angiogenesis. Our study aimed to determine to what extent VEGF receptors and their subtypes are expressed on selected vascular lesions of the orbit. Retrospective case series of all orbital vascular lesions removed by one of the authors (JAG) at the Mayo Clinic. A total of 52 patients who underwent removal of vascular orbital lesions. The pathology specimens from the patients were retrieved, their pathologic diagnosis was confirmed, demographic and clinical information were gathered, and sections from vascular tumors were stained with vascular endothelial growth factor receptor (VEGFR), vascular endothelial growth factor receptor type 1 (VEGFR1), vascular endothelial growth factor receptor type 2 (VEGFR2), and vascular endothelial growth factor receptor type 3 (VEGFR3). The existence and pattern of staining with VEGF and its subtypes on these lesions. There were 28 specimens of venous malformations, 4 capillary hemangiomas, 7 lymphatic malformations, and 6 lymphaticovenous malformations. All samples stained with VEGF, 55% stained with VEGFR1, 98% stained with VEGFR2, and 96% stained with VEGFR3. Most (94%) of the VEGFR2 staining was diffuse. Most orbital vascular lesions express VEGF receptors, which may suggest a future target for nonsurgical treatment. Copyright © 2016 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

  16. Adenosine inhibits neutrophil vascular endothelial growth factor release and transendothelial migration via A2B receptor activation.

    LENUS (Irish Health Repository)

    Wakai, A

    2012-02-03

    The effects of adenosine on neutrophil (polymorphonuclear neutrophils; PMN)-directed changes in vascular permeability are poorly characterized. This study investigated whether adenosine modulates activated PMN vascular endothelial growth factor (vascular permeability factor; VEGF) release and transendothelial migration. PMN activated with tumour necrosis factor-alpha (TNF-alpha, 10 ng\\/mL) were incubated with adenosine and its receptor-specific analogues. Culture supernatants were assayed for VEGF. PMN transendothelial migration across human umbilical vein endothelial cell (HUVEC) monolayers was assessed in vitro. Adhesion molecule receptor expression was assessed flow cytometrically. Adenosine and some of its receptor-specific analogues dose-dependently inhibited activated PMN VEGF release. The rank order of potency was consistent with the affinity profile of human A2B receptors. The inhibitory effect of adenosine was reversed by 3,7-dimethyl-1-propargylxanthine, an A2 receptor antagonist. Adenosine (100 microM) or the A2B receptor agonist 5\\'-N-ethylcarboxamidoadenosine (NECA, 100 microM) significantly reduced PMN transendothelial migration. However, expression of activated PMN beta2 integrins and HUVEC ICAM-1 were not significantly altered by adenosine or NECA. Adenosine attenuates human PMN VEGF release and transendothelial migration via the A2B receptor. This provides a novel target for the modulation of PMN-directed vascular hyperpermeability in conditions such as the capillary leak syndrome.

  17. Fibroblast growth factor 21, fibroblast growth factor receptor 1, and β-Klotho expression in bovine growth hormone transgenic and growth hormone receptor knockout mice.

    Science.gov (United States)

    Brooks, Nicole E; Hjortebjerg, Rikke; Henry, Brooke E; List, Edward O; Kopchick, John J; Berryman, Darlene E

    Although growth hormone (GH) and fibroblast growth factor 21 (FGF21) have a reported relationship, FGF21 and its receptor, fibroblast growth factor receptor 1 (FGFR1) and cofactor β-Klotho (KLB), have not been analyzed in chronic states of altered GH action. The objective of this study was to quantify circulating FGF21 and tissue specific expression of Fgf21, Fgfr1, and Klb in mice with modified GH action. Based on previous studies, we hypothesized that bovine GH transgenic (bGH) mice will be FGF21 resistant and GH receptor knockout (GHR-/-) mice will have normal FGF21 action. Seven-month-old male bGH mice (n=9) and wild type (WT) controls (n=10), and GHR-/- mice (n=8) and WT controls (n=8) were used for all measurements. Body composition was determined before dissection, and tissue weights were measured at the time of dissection. Serum FGF21 levels were evaluated by ELISA. Expression of Fgf21, Fgfr1, and Klb mRNA in white adipose tissue (AT), brown AT, and liver were evaluated by reverse transcription quantitative PCR. As expected, bGH mice had increased body weight (p=3.70E -8 ) but decreased percent fat mass (p=4.87E -4 ). Likewise, GHR-/- mice had decreased body weight (p=1.78E -10 ) but increased percent fat mass (p=1.52E -9 ), due to increased size of the subcutaneous AT depot when normalized to body weight (p=1.60E -10 ). Serum FGF21 levels were significantly elevated in bGH mice (p=0.041) and unchanged in GHR-/- mice (p=0.88). Expression of Fgf21, Fgfr1, and Klb mRNA in white AT and liver were downregulated or unchanged in both bGH and GHR-/- mice. The only exception was Fgf21 expression in brown AT of GHR-/-, which trended toward increased expression (p=0.075). In accordance with our hypothesis, we provide evidence that circulating FGF21 is increased in bGH animals, but remains unchanged in GHR-/- mice. Downregulation or no change in Fgf21, Fgfr1, and Klb expression are seen in white AT, brown AT, and liver of bGH and GHR-/- mice when compared to their

  18. Europium-labeled epidermal growth factor and neurotensin: novel probes for receptor-binding studies.

    Science.gov (United States)

    Mazor, Ohad; Hillairet de Boisferon, Marc; Lombet, Alain; Gruaz-Guyon, Anne; Gayer, Batya; Skrzydelsky, Delphine; Kohen, Fortune; Forgez, Patricia; Scherz, Avigdor; Rostene, William; Salomon, Yoram

    2002-02-01

    We investigated the possibility of labeling two biologically active peptides, epidermal growth factor (EGF) and neurotensin (NT), with europium (Eu)-diethylenetriaminepentaacetic acid. More specifically, we tested them as probes in studying receptor binding using time-resolved fluorescence of Eu3+. The relatively simple synthesis yields ligands with acceptable binding characteristics similar to isotopically labeled derivatives. The binding affinity (Kd) of labeled Eu-EGF to human A431 epidermal carcinoid cells was 3.6 +/- 1.2 nM, similar to the reported Kd values of EGF, whereas the Kd of Eu-NT to human HT29 colon cancer cells (7.4 +/- 0.5 nM) or to Chinese hamster ovary (CHO) cells transfected with the high-affinity NT receptor (CHO-NT1) were about 10-fold higher than the Kd values of NT. The bioactivity of the Eu-labeled EGF as determined by stimulation of cultured murine D1 hematopoietic cell proliferation was nearly the same as that obtained with native EGF. The maximal stimulation of Ca2+ influx with NT and Eu-NT in CHO-NT1 cells was similar, but the respective K0.5 values were 20 pM and 1 nM, corresponding to differences in the binding affinities previously described. The results of these studies indicate that Eu labeling of peptide hormones and growth factor molecules ranging from 10(3) to 10(5) Da can be conveniently accomplished. Importantly, the Eu-labeled products are stable for approximately 2 years and are completely safe for laboratory use compared to the biohazardous radioligands. Thus, Eu-labeled peptides present an attractive alternative for commonly used radiolabeled ligands in biological studies in general and in receptor assays in particular.

  19. Fibroblast growth factor receptor 4 regulates tumor invasion by coupling fibroblast growth factor signaling to extracellular matrix degradation

    DEFF Research Database (Denmark)

    Sugiyama, Nami; Varjosalo, Markku; Meller, Pipsa

    2010-01-01

    /stroma border and tumor invasion front. The strongest overall coexpression was found in prostate carcinoma. Studies with cultured prostate carcinoma cell lines showed that the FGFR4-R388 variant, which has previously been associated with poor cancer prognosis, increased MT1-MMP-dependent collagen invasion......Aberrant expression and polymorphism of fibroblast growth factor receptor 4 (FGFR4) has been linked to tumor progression and anticancer drug resistance. We describe here a novel mechanism of tumor progression by matrix degradation involving epithelial-to-mesenchymal transition in response...... to membrane-type 1 matrix metalloproteinase (MT1-MMP, MMP-14) induction at the edge of tumors expressing the FGFR4-R388 risk variant. Both FGFR4 and MT1-MMP were upregulated in tissue biopsies from several human cancer types including breast adenocarcinomas, where they were partially coexpressed at the tumor...

  20. Development of epidermal growth factor receptor targeted therapy in pancreatic cancer.

    Science.gov (United States)

    Qing, Liu; Qing, Wang

    2018-02-01

    The epidermal growth factor receptor (EGFR) family are a series of important cancer therapeutic targets involved in cancer biology. These genes play an important role in tumor biological characteristics including angiogenesis, cell survival, invasion and glucose metabolism. In recent years, progresses have been achieved upon the cellular and molecular biological characteristics of EGFR and its role in cancer development based on the study of tumor specimens and experimental animal model. EGFR(HER1/ErbB) is overexpressed in over sixty percent of triple-negative breast cancers and occurs in pancreatic, bladder, lung and head-and-neck cancers. Up to now, EGFR inhibitors have been applied in various of cancer, such as lung, breast, bladder and head and neck cancers etc., in which the combination of EGFR inhibitors plus chemotherapeutic agents is now seen as the standard of care for advanced/metastatic pancreatic cancer. For these reasons, EGFR inhibitors and their therapeutic effect for pancreatic cancer is becoming the focus in Laboratory and clinical research. In this paper, research progress of the development of epidermal growth factor receptor targeted therapy in pancreatic cancer is introduced.

  1. Therapies based on inhibitors of the epidermal growth factor receptor: enclosing the future

    International Nuclear Information System (INIS)

    Diaz, Arlhee; Lage, Agustin

    2007-01-01

    The Epidermal Growth Factor Receptor (EGFR) is considered an important target for rational drug design due to its key role in numerous tumors. Potential contribution of EGFR-related signaling pathways to promote tumorigenic processes, including cell proliferation, angiogenesis, and resistance to apoptosis has been well established. Two classes of anti-EGFR agents in late-stage clinical testing include monoclonal antibodies against extracellular EGFR domain (Cetuximab, Nimotuzumab) and small molecules tyrosine kinase inhibitors, which inhibit the receptor enzyme activity (Gefitinib, Erlotinib). A considerable body of evidence has emerged since its introduction in the treatment of cancer patients. However, important questions such as reliable surrogate markers to predict response to the treatment, or optimal sequence and combination of these agents with conventional therapies remain to be addressed. Identify and validate predictive factors to select patients likely to respond to EGFR inhibitors, such as mutations that confer resistance versus those associated with sensitivity is required. A better understanding of molecular mechanisms associated with antitumor activity will useful to predict the interaction of these agents with other therapies in order to avoid antagonisms or overlapping effects resulting in no adding effects. Finally, the benefits derived from EGFR inhibitors as first-line therapy in selected populations, and the optimal doses and ways to delivery to the tumor site resulting in optimal target modulation should be established by the ongoing investigation. (Author)

  2. Early clinical development of epidermal growth factor receptor targeted therapy in breast cancer

    Science.gov (United States)

    Matsuda, Naoko; Lim, Bora; Wang, Xiaoping; Ueno, Naoto T.

    2018-01-01

    Introduction Epidermal growth factor receptor (EGFR) targeted treatment has been evaluated but has not shown a clear clinical benefit for breast cancer. This review article aims to consider the knowledge of the biological background of EGFR pathways in dissecting clinical studies of EGFR targeted treatment in breast cancer. Areas covered This review focuses on the role of the EGFR pathway and the investigational drugs that target EGFR for breast cancer. Expert opinion Recent studies have indicated that EGFR targeted therapy for breast cancer has some promising effects for patients with triple-negative breast cancer, basal-like breast cancer, and inflammatory breast cancer. However, predictive and prognostic biomarkers for EGFR targeted therapy have not been identified. The overexpression or amplification of EGFR itself may not be the true factor of induction of the canonical pathway as an oncogenic driver of breast cancer. Instead, downstream, non-canonical pathways related to EGFR may contribute to some aspects of the biological behavior of breast cancer; therefore, the blockade of the receptor could result in sufficient suppression of downstream pathways to inhibit the aggressive behavior of breast cancer. Mechanistic studies to investigate the dynamic interaction between the EGFR pathway and non-canonical pathways are warranted. PMID:28271910

  3. Recurrent exposure to nicotine differentiates human bronchial epithelial cells via epidermal growth factor receptor activation

    International Nuclear Information System (INIS)

    Martinez-Garcia, Eva; Irigoyen, Marta; Anso, Elena; Martinez-Irujo, Juan Jose; Rouzaut, Ana

    2008-01-01

    Cigarette smoking is the major preventable cause of lung cancer in developed countries. Nicotine (3-(1-methyl-2-pyrrolidinyl)-pyridine) is one of the major alkaloids present in tobacco. Besides its addictive properties, its effects have been described in panoply of cell types. In fact, recent studies have shown that nicotine behaves as a tumor promoter in transformed epithelial cells. This research focuses on the effects of acute repetitive nicotine exposure on normal human bronchial epithelial cells (NHBE cells). Here we show that treatment of NHBE cells with recurrent doses of nicotine up to 500 μM triggered cell differentiation towards a neuronal-like phenotype: cells emitted filopodia and expressed neuronal markers such as neuronal cell adhesion molecule, neurofilament-M and the transcription factors neuronal N and Pax-3. We also demonstrate that nicotine treatment induced NF-kB translocation to the nucleus, phosphorylation of the epidermal growth factor receptor (EGFR), and accumulation of heparin binding-EGF in the extracellular medium. Moreover, addition of AG1478, an inhibitor of EGFR tyrosine phosphorylation, or cetuximab, a monoclonal antibody that precludes ligand binding to the same receptor, prevented cell differentiation by nicotine. Lastly, we show that differentiated cells increased their adhesion to the extracellular matrix and their protease activity. Given that several lung pathologies are strongly related to tobacco consumption, these results may help to better understand the damaging consequences of nicotine exposure

  4. Stepwise Progress in Epidermal Growth Factor Receptor/Radiation Studies for Head and Neck Cancer

    International Nuclear Information System (INIS)

    Harari, Paul M.

    2007-01-01

    The U.S. Food and Drug Administration approval of four new epidermal growth factor receptor (EGFR) inhibitors for cancer therapy (cetuximab, panitumumab, gefitinib, and erlotinib) over the last 3 years is a remarkable milestone in oncology. Indeed, molecular inhibition of EGFR signaling represents one of the most promising current arenas for the development of molecular-targeted cancer therapies. Epidermal growth factor receptor inhibitors from both the monoclonal antibody and tyrosine kinase inhibitor class have demonstrated clinical activity in the treatment of a broad spectrum of common human malignancies. For the discipline of radiation oncology, the 2006 report of a phase III trial demonstrating a survival advantage for advanced head and neck cancer patients with the addition of weekly cetuximab during a 7-week course of radiation is particularly gratifying. Indeed, this is the first phase III trial to confirm a survival advantage with the addition of a molecular-targeted agent to radiation. Furthermore, this result seems to have been achieved with only a modest increment in overall treatment toxicity and with very high compliance to the prescribed treatment regimen. Nevertheless, much remains to be learned regarding the rational integration of EGFR inhibitors into cancer treatment regimens, as well as methods to optimize the selection of patients most likely to benefit from EGFR inhibitor strategies

  5. Early clinical development of epidermal growth factor receptor targeted therapy in breast cancer.

    Science.gov (United States)

    Matsuda, Naoko; Lim, Bora; Wang, Xiaoping; Ueno, Naoto T

    2017-04-01

    Epidermal growth factor receptor (EGFR) targeted treatment has been evaluated but has not shown a clear clinical benefit for breast cancer. This review article aims to consider the knowledge of the biological background of EGFR pathways in dissecting clinical studies of EGFR targeted treatment in breast cancer. Areas covered: This review focuses on the role of the EGFR pathway and the investigational drugs that target EGFR for breast cancer. Expert opinion: Recent studies have indicated that EGFR targeted therapy for breast cancer has some promising effects for patients with triple-negative breast cancer, basal-like breast cancer, and inflammatory breast cancer. However, predictive and prognostic biomarkers for EGFR targeted therapy have not been identified. The overexpression or amplification of EGFR itself may not be the true factor of induction of the canonical pathway as an oncogenic driver of breast cancer. Instead, downstream, non-canonical pathways related to EGFR may contribute to some aspects of the biological behavior of breast cancer; therefore, the blockade of the receptor could result in sufficient suppression of downstream pathways to inhibit the aggressive behavior of breast cancer. Mechanistic studies to investigate the dynamic interaction between the EGFR pathway and non-canonical pathways are warranted.

  6. Physiological epidermal growth factor concentrations activate high affinity receptors to elicit calcium oscillations.

    Directory of Open Access Journals (Sweden)

    Béatrice Marquèze-Pouey

    Full Text Available Signaling mediated by the epidermal growth factor (EGF is crucial in tissue development, homeostasis and tumorigenesis. EGF is mitogenic at picomolar concentrations and is known to bind its receptor on high affinity binding sites depending of the oligomerization state of the receptor (monomer or dimer. In spite of these observations, the cellular response induced by EGF has been mainly characterized for nanomolar concentrations of the growth factor, and a clear definition of the cellular response to circulating (picomolar concentrations is still lacking. We investigated Ca2+ signaling, an early event in EGF responses, in response to picomolar doses in COS-7 cells where the monomer/dimer equilibrium is unaltered by the synthesis of exogenous EGFR. Using the fluo5F Ca2+ indicator, we found that picomolar concentrations of EGF induced in 50% of the cells a robust oscillatory Ca2+ signal quantitatively similar to the Ca2+ signal induced by nanomolar concentrations. However, responses to nanomolar and picomolar concentrations differed in their underlying mechanisms as the picomolar EGF response involved essentially plasma membrane Ca2+ channels that are not activated by internal Ca2+ store depletion, while the nanomolar EGF response involved internal Ca2+ release. Moreover, while the picomolar EGF response was modulated by charybdotoxin-sensitive K+ channels, the nanomolar response was insensitive to the blockade of these ion channels.

  7. Physiological epidermal growth factor concentrations activate high affinity receptors to elicit calcium oscillations.

    Science.gov (United States)

    Marquèze-Pouey, Béatrice; Mailfert, Sébastien; Rouger, Vincent; Goaillard, Jean-Marc; Marguet, Didier

    2014-01-01

    Signaling mediated by the epidermal growth factor (EGF) is crucial in tissue development, homeostasis and tumorigenesis. EGF is mitogenic at picomolar concentrations and is known to bind its receptor on high affinity binding sites depending of the oligomerization state of the receptor (monomer or dimer). In spite of these observations, the cellular response induced by EGF has been mainly characterized for nanomolar concentrations of the growth factor, and a clear definition of the cellular response to circulating (picomolar) concentrations is still lacking. We investigated Ca2+ signaling, an early event in EGF responses, in response to picomolar doses in COS-7 cells where the monomer/dimer equilibrium is unaltered by the synthesis of exogenous EGFR. Using the fluo5F Ca2+ indicator, we found that picomolar concentrations of EGF induced in 50% of the cells a robust oscillatory Ca2+ signal quantitatively similar to the Ca2+ signal induced by nanomolar concentrations. However, responses to nanomolar and picomolar concentrations differed in their underlying mechanisms as the picomolar EGF response involved essentially plasma membrane Ca2+ channels that are not activated by internal Ca2+ store depletion, while the nanomolar EGF response involved internal Ca2+ release. Moreover, while the picomolar EGF response was modulated by charybdotoxin-sensitive K+ channels, the nanomolar response was insensitive to the blockade of these ion channels.

  8. Insulin-like growth factor receptor inhibitors: baby or the bathwater?

    Science.gov (United States)

    Yee, Douglas

    2012-07-03

    The success of targeted therapies for cancer is undisputed; strong preclinical evidence has resulted in the approval of several new agents for cancer treatment. The type I insulin-like growth factor receptor (IGF1R) appeared to be one of these promising new targets. Substantial population and preclinical data have all pointed toward this pathway as an important regulator of tumor cell biology. Although early results from clinical trials that targeted the IGF1R showed some evidence of response, larger randomized phase III trials have not shown clear clinical benefit of targeting this pathway in combination with conventional strategies. These disappointing results have resulted in the discontinuation of several anti-IGF1R programs. However, the conduct of these trials has brought to the forefront several important factors that need to be considered in the conduct of future clinical trials. The need to develop biomarkers, a clearer understanding of insulin receptor function, and defining rational combination regimens all require further consideration. In this commentary, the current state of IGF1R inhibitors in cancer therapy is reviewed.

  9. Inhibition of fibroblast growth factor receptor 3-dependent lung adenocarcinoma with a human monoclonal antibody

    Directory of Open Access Journals (Sweden)

    Yongjun Yin

    2016-05-01

    Full Text Available Activating mutations in fibroblast growth factor receptor 3 (FGFR3 have been identified in multiple types of human cancer and in congenital birth defects. In human lung cancer, fibroblast growth factor 9 (FGF9, a high-affinity ligand for FGFR3, is overexpressed in 10% of primary resected non-small cell lung cancer (NSCLC specimens. Furthermore, in a mouse model where FGF9 can be induced in lung epithelial cells, epithelial proliferation and ensuing tumorigenesis is dependent on FGFR3. To develop new customized therapies for cancers that are dependent on FGFR3 activation, we have used this mouse model to evaluate a human monoclonal antibody (D11 with specificity for the extracellular ligand-binding domain of FGFR3, that recognizes both human and mouse forms of the receptor. Here, we show that D11 effectively inhibits signaling through FGFR3 in vitro, inhibits the growth of FGFR3-dependent FGF9-induced lung adenocarcinoma in mice, and reduces tumor-associated morbidity. Given the potency of FGF9 in this mouse model and the absolute requirement for signaling through FGFR3, this study validates the D11 antibody as a potentially useful and effective reagent for treating human cancers or other pathologies that are dependent on activation of FGFR3.

  10. Immunohistochemical detection of epidermal growth factor receptor in radiation-induced lung tumors in Beagle dogs

    Energy Technology Data Exchange (ETDEWEB)

    Gillett, N A; Haley, P J; Hahn, F F

    1988-12-01

    Increased levels of epidermal growth factor receptor have been reported in a variety of tumors, including pulmonary squamous cell carcinomas in man. The purpose of this study was to determine if increased levels of epidermal growth factor (EGFR) were present in lung tumors from Beagle dogs that had been exposed to {sup 239}PuO{sub 2}- Using immunohistochemical techniques, sections from 17 lung tumors were examined for the presence of EGFR. Seven of the tumors were strongly positive for EGFR; the remainder of the tumors and the normal lung sections were negative. The positive immunostaining could not be correlated with the histologic phenotype of the tumors. Work is in progress to determine the level of EGFR in preneoplastic, proliferative epithelial foci in the Iung. (author)

  11. Sex, Receptors and Attachment: A Review of Individual Factors Influencing Response to Oxytocin

    Directory of Open Access Journals (Sweden)

    Kai S Macdonald

    2013-01-01

    Full Text Available As discussed in the larger review in this special issue (MacDonald and Feifel, intranasal oxytocin (IN OT is demonstrating a growing potential as a therapeutic agent in psychiatry. Importantly, research suggests that a variety of individual factors may influence a person’s response to OT. In this mini-review, I provides a review of three: (1 sex and hormonal status; (2 genetic variation in aspects of the OT system (i.e. OT receptors; and (3 attachment history. Each of these factors will be important to monitor as we strive to develop a richer understanding of OT's role in human development, brain-based disease, and the potential for individualized, OT-targeted treatments.

  12. Mechanical stretch augments insulin-induced vascular smooth muscle cell proliferation by insulin-like growth factor-1 receptor

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Gang [Department of Pharmacology, Faculty of Medicine, Kagawa University, Kagawa (Japan); Department of Anesthesiology, First Affiliated Hospital of China Medical University, Shenyang (China); Hitomi, Hirofumi, E-mail: hitomi@kms.ac.jp [Department of Pharmacology, Faculty of Medicine, Kagawa University, Kagawa (Japan); Hosomi, Naohisa [Department of Cardiorenal and Cerebrovascular Medicine, Faculty of Medicine, Kagawa University, Kagawa (Japan); Lei, Bai; Nakano, Daisuke [Department of Pharmacology, Faculty of Medicine, Kagawa University, Kagawa (Japan); Deguchi, Kazushi; Mori, Hirohito; Masaki, Tsutomu [Department of Gastroenterology and Neurology, Faculty of Medicine, Kagawa University, Kagawa (Japan); Ma, Hong [Department of Anesthesiology, First Affiliated Hospital of China Medical University, Shenyang (China); Griendling, Kathy K. [Department of Medicine, Division of Cardiology, Emory University School of Medicine, Atlanta, GA (United States); Nishiyama, Akira [Department of Pharmacology, Faculty of Medicine, Kagawa University, Kagawa (Japan)

    2011-10-15

    Insulin resistance and hypertension have been implicated in the pathogenesis of cardiovascular disease; however, little is known about the roles of insulin and mechanical force in vascular smooth muscle cell (VSMC) remodeling. We investigated the contribution of mechanical stretch to insulin-induced VSMC proliferation. Thymidine incorporation was stimulated by insulin in stretched VSMCs, but not in un-stretched VSMCs. Insulin increased 2-deoxy-glucose incorporation in both stretched and un-stretched VSMCs. Mechanical stretch augmented insulin-induced extracellular signal-regulated kinase (ERK) and Akt phosphorylation. Inhibitors of epidermal growth factor (EGF) receptor tyrosine kinase and Src attenuated insulin-induced ERK and Akt phosphorylation, as well as thymidine incorporation, whereas 2-deoxy-glucose incorporation was not affected by these inhibitors. Moreover, stretch augmented insulin-like growth factor (IGF)-1 receptor expression, although it did not alter the expression of insulin receptor and insulin receptor substrate-1. Insulin-induced ERK and Akt activation, and thymidine incorporation were inhibited by siRNA for the IGF-1 receptor. Mechanical stretch augments insulin-induced VSMC proliferation via upregulation of IGF-1 receptor, and downstream Src/EGF receptor-mediated ERK and Akt activation. Similar to in vitro experiment, IGF-1 receptor expression was also augmented in hypertensive rats. These results provide a basis for clarifying the molecular mechanisms of vascular remodeling in hypertensive patients with hyperinsulinemia. -- Highlights: {yields} Mechanical stretch augments insulin-induced VSMC proliferation via IGF-1 receptor. {yields} Src/EGFR-mediated ERK and Akt phosphorylation are augmented in stretched VSMCs. {yields} Similar to in vitro experiment, IGF-1 receptor is increased in hypertensive rats. {yields} Results provide possible mechanisms of vascular remodeling in hypertension with DM.

  13. Potent and long-acting corticotropin releasing factor (CRF) receptor 2 selective peptide competitive antagonists.

    Science.gov (United States)

    Rivier, J; Gulyas, J; Kirby, D; Low, W; Perrin, M H; Kunitake, K; DiGruccio, M; Vaughan, J; Reubi, J C; Waser, B; Koerber, S C; Martinez, V; Wang, L; Taché, Y; Vale, W

    2002-10-10

    We present evidence that members of the corticotropin releasing factor (CRF) family assume distinct structures when interacting with the CRF(1) and CRF(2) receptors. Predictive methods, physicochemical measurements, and structure-activity relationship studies have suggested that CRF, its family members, and competitive antagonists such as astressin [cyclo(30-33)[DPhe(12),Nle(21),Glu(30),Lys(33),Nle(38)]hCRF((12-41))] assume an alpha-helical conformation when interacting with their receptors. We had shown that alpha-helical CRF((9-41)) and sauvagine showed some selectivity for CRF receptors other than that responsible for ACTH secretion(1) and later for CRF2.(2) More recently, we suggested the possibility of a helix-turn-helix motif around a turn encompassing residues 30-33(3) that would confer high affinity for both CRF(1) and CRF(2)(2,4) in agonists and antagonists of all members of the CRF family.(3) On the other hand, the substitutions that conferred ca. 100-fold CRF(2) selectivity to the antagonist antisauvagine-30 [[DPhe(11),His(12)]sauvagine((11-40))] did not confer such property to the corresponding N-terminally extended agonists. We find here that a Glu(32)-Lys(35) side chain to side chain covalent lactam constraint in hCRF and the corresponding Glu(31)-Lys(34) side chain to side chain covalent lactam constraint in sauvagine yield potent ligands that are selective for CRF(2). Additionally, we introduced deletions and substitutions known to increase duration of action to yield antagonists such as cyclo(31-34)[DPhe(11),His(12),C(alpha)MeLeu(13,39),Nle(17),Glu(31),Lys(34)]Ac-sauvagine((8-40)) (astressin(2)-B) with CRF(2) selectivities greater than 100-fold. CRF receptor autoradiography was performed in rat tissue known to express CRF(2) and CRF(1) in order to confirm that astressin(2)-B could indeed bind to established CRF(2) but not CRF(1) receptor-expressing tissues. Extended duration of action of astressin(2)-B vs that of antisauvagine-30 is demonstrated in

  14. Coagulation factor VII is regulated by androgen receptor in breast cancer.

    Science.gov (United States)

    Naderi, Ali

    2015-02-01

    Androgen receptor (AR) is widely expressed in breast cancer; however, there is limited information on the key molecular functions and gene targets of AR in this disease. In this study, gene expression data from a cohort of 52 breast cancer cell lines was analyzed to identify a network of AR co-expressed genes. A total of 300 genes, which were significantly enriched for cell cycle and metabolic functions, showed absolute correlation coefficients (|CC|) of more than 0.5 with AR expression across the dataset. In this network, a subset of 35 "AR-signature" genes were highly co-expressed with AR (|CC|>0.6) that included transcriptional regulators PATZ1, NFATC4, and SPDEF. Furthermore, gene encoding coagulation factor VII (F7) demonstrated the closest expression pattern with AR (CC=0.716) in the dataset and factor VII protein expression was significantly associated to that of AR in a cohort of 209 breast tumors. Moreover, functional studies demonstrated that AR activation results in the induction of factor VII expression at both transcript and protein levels and AR directly binds to a proximal region of F7 promoter in breast cancer cells. Importantly, AR activation in breast cancer cells induced endogenous factor VII activity to convert factor X to Xa in conjunction with tissue factor. In summary, F7 is a novel AR target gene and AR activation regulates the ectopic expression and activity of factor VII in breast cancer cells. These findings have functional implications in the pathobiology of thromboembolic events and regulation of factor VII/tissue factor signaling in breast cancer. Copyright © 2014 Elsevier Inc. All rights reserved.

  15. MiR-125a TNF receptor-associated factor 6 to inhibit osteoclastogenesis

    International Nuclear Information System (INIS)

    Guo, Li-Juan; Liao, Lan; Yang, Li; Li, Yu; Jiang, Tie-Jian

    2014-01-01

    MicroRNAs (miRNAs) play important roles in osteoclastogenesis and bone resorption. In the present study, we found that miR-125a was dramatically down-regulated during macrophage colony stimulating factor (M-CSF) and receptor activator of nuclear factor-κB ligand (RANKL) induced osteoclastogenesis of circulating CD14+ peripheral blood mononuclear cells (PBMCs). Overexpression of miR-125a in CD14+ PBMCs inhibited osteoclastogenesis, while inhibition of miR-125a promoted osteoclastogenesis. TNF receptor-associated factor 6 (TRAF6), a transduction factor for RANKL/RANK/NFATc1 signal, was confirmed to be a target of miR-125a. EMSA and ChIP assays confirmed that NFATc1 bound to the promoter of the miR-125a. Overexpression of NFATc1 inhibited miR-125a transcription, and block of NFATc1 expression attenuated RANKL-regulated miR-125a transcription. Here, we reported that miR-125a played a biological function in osteoclastogenesis through a novel TRAF6/ NFATc1/miR-125a regulatory feedback loop. It suggests that regulation of miR-125a expression may be a potential strategy for ameliorating metabolic disease. - Highlights: • MiR-125a was significantly down-regulated in osteoclastogenesis of CD14+ PBMCs. • MiR-125a inhibited osteoclast differentiation by targeting TRAF6. • NFATc1 inhibited miR-125a transciption by binding to the promoter of miR-125a. • TRAF6/NFATc1 and miR-125a form a regulatory feedback loop in osteoclastogenesis

  16. The SRC homology 2 domain of Rin1 mediates its binding to the epidermal growth factor receptor and regulates receptor endocytosis.

    Science.gov (United States)

    Barbieri, M Alejandro; Kong, Chen; Chen, Pin-I; Horazdovsky, Bruce F; Stahl, Philip D

    2003-08-22

    Activated epidermal growth factor receptors (EGFRs) recruit intracellular proteins that mediate receptor signaling and endocytic trafficking. Rin1, a multifunctional protein, has been shown to regulate EGFR internalization (1). Here we show that EGF stimulation induces a specific, rapid, and transient membrane recruitment of Rin1 and that recruitment is dependent on the Src homology 2 (SH2) domain of Rin1. Immunoprecipitation of EGFR is accompanied by co-immunoprecipitation of Rin1 in a time- and ligand-dependent manner. Association of Rin1 and specifically the SH2 domain of Rin1 with the EGFR was dependent on tyrosine phosphorylation of the intracellular domain of the EGFR. The recruitment of Rin1, observed by light microscopy, indicated that although initially cytosolic, Rin1 was recruited to both plasma membrane and endosomes following EGF addition. Moreover, the expression of the SH2 domain of Rin1 substantially impaired the internalization of EGF without affecting internalization of transferrin. Finally, we found that Rin1 co-immunoprecipitated with a number of tyrosine kinase receptors but not with cargo endocytic receptors. These results indicate that Rin1 provides a link via its SH2 domain between activated tyrosine kinase receptors and the endocytic pathway through the recruitment and activation of Rab5a.

  17. Nature and regulation of the receptors for insulin-like growth factors

    International Nuclear Information System (INIS)

    Rechler, M.M.; Nissley, S.P.

    1985-01-01

    Two subtypes of IGF receptors have been identified. Type I IGF receptors have a Mr greater than 300,000 and are composed of disulfide-linked 130,000-dalton (alpha) and approximately 90,000-dalton (beta) subunits. Type I receptors preferentially bind IGF-I but also bind IGF-II and, more weakly, insulin. Type II IGF receptors consist of a 250,000-dalton protein that contains internal disulfide bonds but is not linked to other membrane components. Type II receptors bind IGF-II with higher affinity than IGF-I. They do not interact with even very high concentrations of insulin. Type I IGF receptors and insulin receptors are homologous structures. Type II IGF receptors do not appear to be homologous to type I receptors. Type II receptors do not appear to be downregulated. Insulin acutely upregulates type II IGF receptors in intact rat adipose cells by effecting a redistribution of receptors cycling between a large intracellular pool and the plasma membrane. Insulin and the IGFs elicit the same biological responses, either by cross-reacting with one of the receptors for the heterologous ligand or by concurrent activation of convergent effector pathways by binding to the homologous receptor. Which mechanism is utilized appears to depend more on the tissue than on the biological response. Insulin desensitizes rat hepatoma cells to the actions of insulin and IGFs, mediated by both insulin and IGF receptors, by mechanisms distal to hormone binding and possibly common to IGF and insulin effector pathways

  18. Direct demonstration of rapid insulin-like growth factor II receptor internalization and recycling in rat adipocytes. Insulin stimulates 125I-insulin-like growth factor II degradation by modulating the IGF-II receptor recycling process

    International Nuclear Information System (INIS)

    Oka, Y.; Rozek, L.M.; Czech, M.P.

    1985-01-01

    The photoactive insulin-like growth factor (IGF)-II analogue 4-azidobenzoyl- 125 I-IGF-II was synthesized and used to label specifically and covalently the Mr = 250,000 Type II IGF receptor. When rat adipocytes are irradiated after a 10-min incubation with 4-azidobenzoyl- 125 I-IGF-II at 10 degrees C and immediately homogenized, most of the labeled IGF-II receptors are associated with the plasma membrane fraction, indicating that receptors accessible to the labeling reagent at low temperature are on the cell surface. However, when the photolabeled cells are incubated at 37 degrees C for various times before homogenization, labeled IGF-II receptors are rapidly internalized with a half-time of 3.5 min as evidenced by a loss from the plasma membrane fraction and a concomitant appearance in the low density microsome fraction. The steady state level of cell surface IGF-II receptors in the presence or absence of IGF-II remains constant under these conditions, demonstrating that IGF-II receptors rapidly recycle back to the cell surface at the same rate as receptor internalization. Using the above methodology, it is shown that acute insulin action: 1) increases the steady state number of cell surface IGF-II receptors; 2) increases the number of ligand-bound IGF-II receptors that are internalized per unit of time; and 3) increases the rate of cellular 125 I-IGF-II degradation by a process that is blocked by anti-IGF-II receptor antibody

  19. Two signaling molecules share a phosphotyrosine-containing binding site in the platelet-derived growth factor receptor.

    OpenAIRE

    Nishimura, R; Li, W; Kashishian, A; Mondino, A; Zhou, M; Cooper, J; Schlessinger, J

    1993-01-01

    Autophosphorylation sites of growth factor receptors with tyrosine kinase activity function as specific binding sites for Src homology 2 (SH2) domains of signaling molecules. This interaction appears to be a crucial step in a mechanism by which receptor tyrosine kinases relay signals to downstream signaling pathways. Nck is a widely expressed protein consisting exclusively of SH2 and SH3 domains, the overexpression of which causes cell transformation. It has been shown that various growth fac...

  20. Functional variation in the arginine vasopressin 2 receptor as a modifier of human plasma von Willebrand factor levels

    DEFF Research Database (Denmark)

    Nossent, Anne Yaël; Robben, J H; Deen, P M T

    2010-01-01

    SUMMARY OBJECTIVES: Stimulation of arginine vasopressin 2 receptor (V2R) with arginine vasopressin (AVP) results in a rise in von Willebrand factor (VWF) and factor VIII plasma levels. We hypothesized that gain-of-function variations in the V2R gene (AVPR2) would lead to higher plasma levels of V...

  1. Expression and Regulation of Corticotropin-Releasing Factor Receptor Type 2 beta in Developing and Mature Mouse Skeletal Muscle

    NARCIS (Netherlands)

    Kuperman, Yael; Issler, Orna; Vaughan, Joan; Bilezikjian, Louise; Vale, Wylie; Chen, Alon

    Corticotropin-releasing factor receptor type 2 (CRFR2) is highly expressed in skeletal muscle (SM) tissue where it is suggested to inhibit interactions between insulin signaling pathway components affecting whole-body glucose homeostasis. However, little is known about factors regulating SM CRFR2

  2. Expression of receptors for putative anabolic growth factors in human intervertebral disc: implications for repair and regeneration of the disc.

    Science.gov (United States)

    Le Maitre, Christine L; Richardson, Stephen M A; Baird, Pauline; Freemont, Anthony J; Hoyland, Judith A

    2005-12-01

    Low back pain (LBP) is a common, debilitating and economically important disorder. Current evidence implicates loss of intervertebral disc (IVD) matrix consequent upon 'degeneration' as a major cause of LBP. Degeneration of the IVD involves increases in degradative enzymes and decreases in the extracellular matrix (ECM) component in a process that is controlled by a range of cytokines and growth factors. Studies have suggested using anabolic growth factors to regenerate the normal matrix of the IVD, hence restoring disc height and reversing degenerative disc disease. However, for such therapies to be successful it is vital that the target cells (i.e. the disc cells) express the appropriate receptors. This immunohistochemical study has for the first time investigated the expression and localization of four potentially beneficial growth factor receptors (i.e. TGFbetaRII, BMPRII, FGFR3 and IGFRI) in non-degenerate and degenerate human IVDs. Receptor expression was quantified across regions of the normal and degenerate disc and showed that cells of the nucleus pulposus (NP) and inner annulus fibrosus (IAF) expressed significantly higher levels of the four growth factor receptors investigated. There were no significant differences between the four growth factor expression in non-degenerate and degenerate biopsies. However, expression of TGFbetaRII, FGFR3 and IGFRI, but not BMP RII, were observed in the ingrowing blood vessels that characterize part of the disease aetiology. In conclusion, this study has demonstrated the expression of the four growth factor receptors at similar levels in the chondrocyte-like cells of the NP and IAF in both non-degenerate and degenerate discs, implicating a role in normal disc homeostasis and suggesting that the application of these growth factors to the degenerate human IVD would stimulate matrix production. However, the expression of some of the growth factor receptors on ingrowing blood vessels might be problematic in a therapeutic

  3. NF-κB Protects NKT Cells from Tumor Necrosis Factor Receptor 1-induced Death.

    Science.gov (United States)

    Kumar, Amrendra; Gordy, Laura E; Bezbradica, Jelena S; Stanic, Aleksandar K; Hill, Timothy M; Boothby, Mark R; Van Kaer, Luc; Joyce, Sebastian

    2017-11-15

    Semi-invariant natural killer T (NKT) cells are innate-like lymphocytes with immunoregulatory properties. NKT cell survival during development requires signal processing by activated RelA/NF-κB. Nonetheless, the upstream signal(s) integrated by NF-κB in developing NKT cells remains incompletely defined. We show that the introgression of Bcl-x L -coding Bcl2l1 transgene into NF-κB signalling-deficient IκBΔN transgenic mouse rescues NKT cell development and differentiation in this mouse model. We reasoned that NF-κB activation was protecting developing NKT cells from death signals emanating either from high affinity agonist recognition by the T cell receptor (TCR) or from a death receptor, such as tumor necrosis factor receptor 1 (TNFR1) or Fas. Surprisingly, the single and combined deficiency in PKC-θ or CARMA-1-the two signal transducers at the NKT TCR proximal signalling node-only partially recapitulated the NKT cell deficiency observed in IκBΔN tg mouse. Accordingly, introgression of the Bcl2l1 transgene into PKC-θ null mouse failed to rescue NKT cell development. Instead, TNFR1-deficiency, but not the Fas-deficiency, rescued NKT cell development in IκBΔN tg mice. Consistent with this finding, treatment of thymocytes with an antagonist of the inhibitor of κB kinase -which blocks downstream NF-κB activation- sensitized NKT cells to TNF-α-induced cell death in vitro. Hence, we conclude that signal integration by NF-κB protects developing NKT cells from death signals emanating from TNFR1, but not from the NKT TCR or Fas.

  4. Effect of corticotropin-releasing factor receptor antagonist on psychologically suppressed masculine sexual behavior in rats.

    Science.gov (United States)

    Miwa, Yoshiji; Nagase, Keiko; Oyama, Nobuyuki; Akino, Hironobu; Yokoyama, Osamu

    2011-03-01

    Corticotropin-releasing factor (CRF) coordinates various responses of the body to stress, and CRF receptors are important targets of treatment for stress-related disorders. To investigate the effect of a nonselective CRF receptor antagonist, astressin, on suppression of masculine sexual behavior by psychological stress in rats. First, we investigated the influence of psychological stress, induced 2 hours per day for three consecutive days, on sexual behavior. Then, rats were divided into 4 groups: a control group, an astressin administration group (A), a psychological stress loading group (PS), and a psychological stress loading and astressin administration group (PS + A). The rats were exposed to sham or psychological stress for three consecutive days. After the last stress loading, the rats were injected with vehicle or astressin, and their sexual behavior was observed. We also measured serum levels of adrenocorticotropic hormone (ACTH). The effects of astressin on sexual behavior and serum levels of ACTH in rats affected by psychological stress were determined. Sexual behavior was reduced after psychological stress loading. The PS rats had significantly longer mount, intromission, and ejaculation latencies and lower ejaculation frequency than did the control, A, and PS + A rats. The intromission latency and ejaculation frequency in the PS + A rats did not achieve the level observed in the controls. There was no significant difference in these parameters between the control and A rats. Serum ACTH levels were significantly lower in PS + A rats than in PS rats. Psychologically suppressed masculine sexual behavior could be partially recovered with astressin administration in rats. These data provide a rationale for the further study of CRF receptor antagonists as novel agents for treating psychological sexual disorders. © 2010 International Society for Sexual Medicine.

  5. Characterization of germ cell-specific expression of the orphan nuclear receptor, germ cell nuclear factor.

    Science.gov (United States)

    Katz, D; Niederberger, C; Slaughter, G R; Cooney, A J

    1997-10-01

    Nuclear receptors, such as those for androgens, estrogens, and progesterones, control many reproductive processes. Proteins with structures similar to these receptors, but for which ligands have not yet been identified, have been termed orphan nuclear receptors. One of these orphans, germ cell nuclear factor (GCNF), has been shown to be germ cell specific in the adult and, therefore, may also participate in the regulation of reproductive functions. In this paper, we examine more closely the expression patterns of GCNF in germ cells to begin to define spatio-temporal domains of its activity. In situ hybridization showed that GCNF messenger RNA (mRNA) is lacking in the testis of hypogonadal mutant mice, which lack developed spermatids, but is present in the wild-type testis. Thus, GCNF is, indeed, germ cell specific in the adult male. Quantitation of the specific in situ hybridization signal in wild-type testis reveals that GCNF mRNA is most abundant in stage VII round spermatids. Similarly, Northern analysis and specific in situ hybridization show that GCNF expression first occurs in testis of 20-day-old mice, when round spermatids first emerge. Therefore, in the male, GCNF expression occurs postmeiotically and may participate in the morphological changes of the maturing spermatids. In contrast, female expression of GCNF is shown in growing oocytes that have not completed the first meiotic division. Thus, GCNF in the female is expressed before the completion of meiosis. Finally, the nature of the two different mRNAs that hybridize to the GCNF complementary DNA was studied. Although both messages contain the DNA binding domain, only the larger message is recognized by a probe from the extreme 3' untranslated region. In situ hybridization with these differential probes demonstrates that both messages are present in growing oocytes. In addition, the coding region and portions of the 3' untranslated region of the GCNF complementary DNA are conserved in the rat.

  6. Oncogenic role of fibroblast growth factor receptor 3 in tumorigenesis of urinary bladder cancer.

    Science.gov (United States)

    Pandith, Arshad A; Shah, Zafar A; Siddiqi, Mushtaq A

    2013-05-01

    Bladder cancer is the second most common genitourinary tumor and constitutes a very heterogeneous disease. Molecular and pathologic studies suggest that low-grade noninvasive and high-grade invasive urothelial cell carcinoma (UCC) arise via distinct pathways. Low-grade noninvasive UCC represent the majority of tumors at presentation. A high proportion of patients with low-grade UCC develop recurrences but usually with no progression to invasive disease. At presentation, a majority of the bladder tumors (70%-80%) are low-grade noninvasive (pTa). Several genetic changes may occur in bladder cancer, but activating mutations in the fibroblast growth factor receptor 3 (FGFR3) genes are the most common and most specific genetic abnormality in bladder cancer. Interestingly, these mutations are associated with bladder tumors of low stage and grade, which makes the FGFR3 mutation the first marker that can be used for diagnosis of noninvasive bladder tumors. Since the first report of FGFR3 involvement in bladder tumors, numerous studies have been conducted to understand its function and thereby confirm the oncogenic role of this receptor particularly in noninvasive groups. Efforts are on to exploit this receptor as a therapeutic target, which holds much promise in the treatment of bladder cancer, particularly low-grade noninvasive tumors. Further studies need to explore the potential use of FGFR3 mutations in bladder cancer diagnosis, prognosis, and in surveillance of patients with bladder cancer. This review focuses on the role of FGFR3 in bladder tumors in the backdrop of various studies published. Copyright © 2013 Elsevier Inc. All rights reserved.

  7. The epidermal growth factor receptor as a target for gastrointestinal cancer therapy.

    Science.gov (United States)

    Tedesco, Karen L; Lockhart, A Craig; Berlin, Jordan D

    2004-10-01

    The epidermal growth factor receptor (EGFR) is a member of the family of transmembrane protein kinase receptors known as the erbB or HER receptor family. When activated, EGFR phosphorylates and activates other intracellular proteins that affect cell signaling pathways, cellular proliferation, control of apoptosis and angiogenesis. EGFR signaling is best thought of as a network of activating and inactivating proteins with EGFR as the entry point into the network. EGFR overexpression occurs in most GI malignancies and while data are not entirely consistent, EGFR overexpression often confers a poor prognosis in those GI malignancies that have been studied. It often correlates with poorly differentiated histology, more advanced stage and other known poor prognostic markers. The EGFR is a tempting target because of its presence and overexpression on so many tumor types. However, downstream of the EGFR are several proteins that may be activated without EGFR thus allowing blockade to be overcome. Therefore, while blocking the activity of the EGFR protein appears to be a promising anticancer strategy, a simplistic strategy of blocking only EGFR is likely to only impact a minority of patients. It is time for the laboratory and clinical researchers to work closely together to develop this treatment strategy, moving back and forth from clinical to laboratory to best understand how to block this network effectively enough to produce a broader antitumor effect. While multiple methods of targeting the EGFR pathway are under development, including the inhibition of downstream proteins, only two modalities have entered clinical trials in GI malignancies: small molecule inhibitors of the intracellular kinase domain of EGFR and antibodies designed to block the extracellular ligand-binding domain of EGFR. EGFR inhibitors are still experimental in every GI malignancy with the notable exception of cetuximab that is approved for second or third-line therapy of metastatic colorectal

  8. Targeting the epidermal growth factor receptor in radiotherapy: radiobiological mechanisms, preclinical and clinical results

    International Nuclear Information System (INIS)

    Baumann, Michael; Krause, Mechthild

    2004-01-01

    Background and purpose: Inhibition of the epidermal growth factor receptor (EGFR) is a fastly developing field in preclinical and clinical cancer research. This review presents the current status of knowledge and discusses radiobiological mechanisms which may underly the efficacy of EGFR inhibitors combined with irradiation. Materials and methods: Preclinical and clinical results on combined targeting of the EGFR and irradiation from the literature and from this laboratory are reviewed. Focus is given to the radiobiological rationale of this approach and to endpoints of experimental radiotherapy. Results: Overexpression of the EGFR is associated with decreased local tumour control after radiotherapy, especially when the overall treatment time is long. Inhibition of the EGFR either alone or in combination with irradiation decreases the growth rate of tumours expressing this receptor. Preclinical data provide proof-of-principle that local tumour control may be improved by combining irradiation with C225 mAb. In a randomised phase III clinical trial, simultaneous irradiation and treatment with the EGFR antibody Cetuximab (Erbitux[reg]; C225) in head and neck cancer patients resulted in significantly improved locoregional tumour control and survival compared to curative irradiation alone. Acute skin reactions increased in the experimental arm. The underlying mechanisms of enhanced radiation effects of combined EGFR inhibition with irradiation and of the partly conflicting results in different studies are poorly understood. There is increasing evidence, that important intertumoral heterogeneity in the response to EGFR inhibition alone and combined with irradiation exists, which appears to be at least partly dependent on specific mutations of the receptor as well as of molecules that are involved in the intracellular signal transduction pathway. Conclusions and outlook: Further investigations at all levels of the translational research chain exploring the mechanisms of

  9. Amphiregulin triggered epidermal growth factor receptor activation confers in vivo crizotinib-resistance of EML4-ALK lung cancer and circumvention by epidermal growth factor receptor inhibitors.

    Science.gov (United States)

    Taniguchi, Hirokazu; Takeuchi, Shinji; Fukuda, Koji; Nakagawa, Takayuki; Arai, Sachiko; Nanjo, Shigeki; Yamada, Tadaaki; Yamaguchi, Hiroyuki; Mukae, Hiroshi; Yano, Seiji

    2017-01-01

    Crizotinib, a first-generation anaplastic lymphoma kinase (ALK) tyrosine-kinase inhibitor, is known to be effective against echinoderm microtubule-associated protein-like 4 (EML4)-ALK-positive non-small cell lung cancers. Nonetheless, the tumors subsequently become resistant to crizotinib and recur in almost every case. The mechanism of the acquired resistance needs to be deciphered. In this study, we established crizotinib-resistant cells (A925LPE3-CR) via long-term administration of crizotinib to a mouse model of pleural carcinomatous effusions; this model involved implantation of the A925LPE3 cell line, which harbors the EML4-ALK gene rearrangement. The resistant cells did not have the secondary ALK mutations frequently occurring in crizotinib-resistant cells, and these cells were cross-resistant to alectinib and ceritinib as well. In cell clone #2, which is one of the clones of A925LPE3-CR, crizotinib sensitivity was restored via the inhibition of epidermal growth factor receptor (EGFR) by means of an EGFR tyrosine-kinase inhibitor (erlotinib) or an anti-EGFR antibody (cetuximab) in vitro and in the murine xenograft model. Cell clone #2 did not have an EGFR mutation, but the expression of amphiregulin (AREG), one of EGFR ligands, was significantly increased. A knockdown of AREG with small interfering RNAs restored the sensitivity to crizotinib. These data suggest that overexpression of EGFR ligands such as AREG can cause resistance to crizotinib, and that inhibition of EGFR signaling may be a promising strategy to overcome crizotinib resistance in EML4-ALK lung cancer. © 2016 The Authors. Cancer Science published by John Wiley & Sons Australia, Ltd on behalf of Japanese Cancer Association.

  10. Fibroblast growth factor receptor 4 (FGFR4) and fibroblast growth factor 19 (FGF19) autocrine enhance breast cancer cells survival.

    Science.gov (United States)

    Tiong, Kai Hung; Tan, Boon Shing; Choo, Heng Lungh; Chung, Felicia Fei-Lei; Hii, Ling-Wei; Tan, Si Hoey; Khor, Nelson Tze Woei; Wong, Shew Fung; See, Sze-Jia; Tan, Yuen-Fen; Rosli, Rozita; Cheong, Soon-Keng; Leong, Chee-Onn

    2016-09-06

    Basal-like breast cancer is an aggressive tumor subtype with poor prognosis. The discovery of underlying mechanisms mediating tumor cell survival, and the development of novel agents to target these pathways, is a priority for patients with basal-like breast cancer. From a functional screen to identify key drivers of basal-like breast cancer cell growth, we identified fibroblast growth factor receptor 4 (FGFR4) as a potential mediator of cell survival. We found that FGFR4 mediates cancer cell survival predominantly via activation of PI3K/AKT. Importantly, a subset of basal-like breast cancer cells also secrete fibroblast growth factor 19 (FGF19), a canonical ligand specific for FGFR4. siRNA-mediated silencing of FGF19 or neutralization of extracellular FGF19 by anti-FGF19 antibody (1A6) decreases AKT phosphorylation, suppresses cancer cell growth and enhances doxorubicin sensitivity only in the FGFR4+/FGF19+ breast cancer cells. Consistently, FGFR4/FGF19 co-expression was also observed in 82 out of 287 (28.6%) primary breast tumors, and their expression is strongly associated with AKT phosphorylation, Ki-67 staining, higher tumor stage and basal-like phenotype. In summary, our results demonstrated the presence of an FGFR4/FGF19 autocrine signaling that mediates the survival of a subset of basal-like breast cancer cells and suggest that inactivation of this autocrine loop may potentially serve as a novel therapeutic intervention for future treatment of breast cancers.

  11. Association of Polymorphisms in Connective Tissue Growth Factor and Epidermal Growth Factor Receptor Genes With Human Longevity.

    Science.gov (United States)

    Donlon, Timothy A; Morris, Brian J; He, Qimei; Chen, Randi; Masaki, Kamal H; Allsopp, Richard C; Willcox, D Craig; Tranah, Gregory J; Parimi, Neeta; Evans, Daniel S; Flachsbart, Friederike; Nebel, Almut; Kim, Duk-Hwan; Park, Joobae; Willcox, Bradley J

    2017-08-01

    Growth pathways play key roles in longevity. The present study tested single-nucleotide polymorphisms (SNPs) in the connective tissue growth factor gene (CTGF) and the epidermal growth factor receptor gene (EGFR) for association with longevity. Comparison of allele and genotype frequencies of 12 CTGF SNPs and 41 EGFR SNPs between 440 American men of Japanese ancestry aged ≥95 years and 374 men of average life span revealed association with longevity at the p cases, consistent with heterozygote advantage in living to extreme old age. No associations of the most significant SNPs were observed in whites or Koreans. In conclusion, the present findings indicate that genetic variation in CTGF and EGFR may contribute to the attainment of extreme old age in Japanese. More research is needed to confirm that genetic variation in CTGF and EGFR contributes to the attainment of extreme old age across human populations. © The Author 2016. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  12. Binding characteristics of brain-derived neurotrophic factor to its receptors on neurons from the chick embryo

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez-Tebar, A.; Barde, Y.A.

    1988-09-01

    Brain-derived neurotrophic factor (BDNF), a protein known to support the survival of embryonic sensory neurons and retinal ganglion cells, was derivatized with 125I-Bolton-Hunter reagent and obtained in a biologically active, radioactive form (125I-BDNF). Using dorsal root ganglion neurons from chick embryos at 9 d of development, the basic physicochemical parameters of the binding of 125I-BDNF with its receptors were established. Two different classes of receptors were found, with dissociation constants of 1.7 x 10(-11) M (high-affinity receptors) and 1.3 x 10(-9) M (low-affinity receptors). Unlabeled BDNF competed with 125I-BDNF for binding to the high-affinity receptors with an inhibition constant essentially identical to the dissociation constant of the labeled protein: 1.2 x 10(-11) M. The association and dissociation rates from both types of receptors were also determined, and the dissociation constants calculated from these kinetic experiments were found to correspond to the results obtained from steady-state binding. The number of high-affinity receptors (a few hundred per cell soma) was 15 times lower than that of low-affinity receptors. No high-affinity receptors were found on sympathetic neurons, known not to respond to BDNF, although specific binding of 125I-BDNF to these cells was detected at a high concentration of the radioligand. These results are discussed and compared with those obtained with nerve growth factor on the same neuronal populations.

  13. Binding characteristics of brain-derived neurotrophic factor to its receptors on neurons from the chick embryo

    International Nuclear Information System (INIS)

    Rodriguez-Tebar, A.; Barde, Y.A.

    1988-01-01

    Brain-derived neurotrophic factor (BDNF), a protein known to support the survival of embryonic sensory neurons and retinal ganglion cells, was derivatized with 125I-Bolton-Hunter reagent and obtained in a biologically active, radioactive form (125I-BDNF). Using dorsal root ganglion neurons from chick embryos at 9 d of development, the basic physicochemical parameters of the binding of 125I-BDNF with its receptors were established. Two different classes of receptors were found, with dissociation constants of 1.7 x 10(-11) M (high-affinity receptors) and 1.3 x 10(-9) M (low-affinity receptors). Unlabeled BDNF competed with 125I-BDNF for binding to the high-affinity receptors with an inhibition constant essentially identical to the dissociation constant of the labeled protein: 1.2 x 10(-11) M. The association and dissociation rates from both types of receptors were also determined, and the dissociation constants calculated from these kinetic experiments were found to correspond to the results obtained from steady-state binding. The number of high-affinity receptors (a few hundred per cell soma) was 15 times lower than that of low-affinity receptors. No high-affinity receptors were found on sympathetic neurons, known not to respond to BDNF, although specific binding of 125I-BDNF to these cells was detected at a high concentration of the radioligand. These results are discussed and compared with those obtained with nerve growth factor on the same neuronal populations

  14. The RNA binding protein HuR differentially regulates unique subsets of mRNAs in estrogen receptor negative and estrogen receptor positive breast cancer

    Directory of Open Access Journals (Sweden)

    Chen Jing

    2010-04-01

    Full Text Available Abstract Background The discordance between steady-state levels of mRNAs and protein has been attributed to posttranscriptional control mechanisms affecting mRNA stability and translation. Traditional methods of genome wide microarray analysis, profiling steady-state levels of mRNA, may miss important mRNA targets owing to significant posttranscriptional gene regulation by RNA binding proteins (RBPs. Methods The ribonomic approach, utilizing RNA immunoprecipitation hybridized to microarray (RIP-Chip, provides global identification of putative endogenous mRNA targets of different RBPs. HuR is an RBP that binds to the AU-rich elements (ARE of labile mRNAs, such as proto-oncogenes, facilitating their translation into protein. HuR has been shown to play a role in cancer progression and elevated levels of cytoplasmic HuR directly correlate with increased invasiveness and poor prognosis for many cancers, including those of the breast. HuR has been described to control genes in several of the acquired capabilities of cancer and has been hypothesized to be a tumor-maintenance gene, allowing for cancers to proliferate once they are established. Results We used HuR RIP-Chip as a comprehensive and systematic method to survey breast cancer target genes in both MCF-7 (estrogen receptor positive, ER+ and MDA-MB-231 (estrogen receptor negative, ER- breast cancer cell lines. We identified unique subsets of HuR-associated mRNAs found individually or in both cell types. Two novel HuR targets, CD9 and CALM2 mRNAs, were identified and validated by quantitative RT-PCR and biotin pull-down analysis. Conclusion This is the first report of a side-by-side genome-wide comparison of HuR-associated targets in wild type ER+ and ER- breast cancer. We found distinct, differentially expressed subsets of cancer related genes in ER+ and ER- breast cancer cell lines, and noted that the differential regulation of two cancer-related genes by HuR was contingent upon the cellular

  15. Increased expression of protease-activated receptor 4 and Trefoil factor 2 in human colorectal cancer.

    Directory of Open Access Journals (Sweden)

    Guoyu Yu

    Full Text Available Protease-activated receptor 4 (PAR4, a member of G-protein coupled receptors family, was recently reported to exhibit decreased expression in gastric cancer and esophageal squamous cancer, yet increased expression during the progression of prostate cancer. Trefoil factor 2 (TFF2, a small peptide constitutively expressed in the gastric mucosa, plays a protective role in restitution of gastric mucosa. Altered TFF2 expression was also related to the development of gastrointestinal cancer. TFF2 has been verified to promote cell migration via PAR4, but the roles of PAR4 and TFF2 in the progress of colorectal cancer are still unknown. In this study, the expression level of PAR4 and TFF2 in colorectal cancer tissues was measured using real-time PCR (n = 38, western blotting (n=38 and tissue microarrays (n = 66. The mRNA and protein expression levels of PAR4 and TFF2 were remarkably increased in colorectal cancer compared with matched noncancerous tissues, especially in positive lymph node and poorly differentiated cancers. The colorectal carcinoma cell LoVo showed an increased response to TFF2 as assessed by cell invasion upon PAR4 expression. However, after intervention of PAR4 expression, PAR4 positive colorectal carcinoma cell HT-29 was less responsive to TFF2 in cell invasion. Genomic bisulfite sequencing showed the hypomethylation of PAR4 promoter in colorectal cancer tissues and the hypermethylation in the normal mucosa that suggested the low methylation of promoter was correlated to the increased PAR4 expression. Taken together, the results demonstrated that the up-regulated expression of PAR4 and TFF2 frequently occurs in colorectal cancer tissues, and that overexpression of PAR4 may be resulted from promoter hypomethylation. While TFF2 promotes invasion activity of LoVo cells overexpressing PAR4, and this effect was significantly decreased when PAR4 was knockdowned in HT-29 cells. Our findings will be helpful in further investigations into the

  16. Emerging role of epidermal growth factor receptor inhibition in therapy for advanced malignancy: focus on NSCLC

    International Nuclear Information System (INIS)

    Langer, Corey J.

    2004-01-01

    Combination chemotherapy regimens have emerged as the standard approach in advanced non-small-cell lung cancer. Meta-analyses have demonstrated a 2-month increase in median survival after platinum-based therapy vs. best supportive care, and an absolute 10% improvement in the 1-year survival rate. Just as importantly, cytotoxic therapy has produced benefits in symptom control and quality of life. Newer agents, including the taxanes, vinorelbine, gemcitabine, and irinotecan, have expanded our therapeutic options in the treatment of advanced non-small-cell lung cancer. Despite their contributions, we have reached a therapeutic plateau, with response rates seldom exceeding 30-40% in cooperative group studies and 1-year survival rates stable between 30% and 40%. It is doubtful that substituting one agent for another in various combinations will lead to any further improvement in these rates. The thrust of current research has focused on targeted therapy, and epidermal growth factor receptor inhibition is one of the most promising clinical strategies. Epidermal growth factor receptor inhibitors currently under investigation include the small molecules gefitinib (Iressa, ZD1839) and erlotinib (Tarceva, OSI-774), as well as monoclonal antibodies such as cetuximab (IMC-225, Erbitux). Agents that have only begun to undergo clinical evaluation include CI-1033, an irreversible pan-erbB tyrosine kinase inhibitor, and PKI166 and GW572016, both examples of dual kinase inhibitors (inhibiting epidermal growth factor receptor and Her2). Preclinical models have demonstrated synergy for all these agents in combination with either chemotherapy or radiotherapy, leading to great enthusiasm regarding their ultimate contribution to lung cancer therapy. However, serious clinical challenges persist. These include the identification of the optimal dose(s); the proper integration of these agents into popular, established cytotoxic regimens; and the selection of the optimal setting(s) in which

  17. Pluripotency factors and Polycomb Group proteins repress aryl hydrocarbon receptor expression in murine embryonic stem cells

    Directory of Open Access Journals (Sweden)

    Chia-I Ko

    2014-01-01

    Full Text Available The aryl hydrocarbon receptor (AHR is a transcription factor and environmental sensor that regulates expression of genes involved in drug-metabolism and cell cycle regulation. Chromatin immunoprecipitation analyses, Ahr ablation in mice and studies with orthologous genes in invertebrates suggest that AHR may also play a significant role in embryonic development. To address this hypothesis, we studied the regulation of Ahr expression in mouse embryonic stem cells and their differentiated progeny. In ES cells, interactions between OCT3/4, NANOG, SOX2 and Polycomb Group proteins at the Ahr promoter repress AHR expression, which can also be repressed by ectopic expression of reprogramming factors in hepatoma cells. In ES cells, unproductive RNA polymerase II binds at the Ahr transcription start site and drives the synthesis of short abortive transcripts. Activation of Ahr expression during differentiation follows from reversal of repressive marks in Ahr promoter chromatin, release of pluripotency factors and PcG proteins, binding of Sp factors, establishment of histone marks of open chromatin, and engagement of active RNAPII to drive full-length RNA transcript elongation. Our results suggest that reversible Ahr repression in ES cells holds the gene poised for expression and allows for a quick switch to activation during embryonic development.

  18. Insulin and insulin-like growth factor receptors in the brain: physiological and pathological aspects.

    Science.gov (United States)

    Werner, Haim; LeRoith, Derek

    2014-12-01

    The involvement of insulin, the insulin-like growth factors (IGF1, IGF2) and their receptors in central nervous system development and function has been the focus of scientific interest for more than 30 years. The insulin-like peptides, both locally-produced proteins as well as those transported from the circulation into the brain via the blood-brain barrier, are involved in a myriad of biological activities. These actions include, among others, neuronal survival, neurogenes, angiogenesis, excitatory and inhibitory neurotransmission, regulation of food intake, and cognition. In recent years, a linkage between brain insulin/IGF1 and certain neuropathologies has been identified. Epidemiological studies have demonstrated a correlation between diabetes (mainly type 2) and Alzheimer׳s disease. In addition, an aberrant decline in IGF1 values was suggested to play a role in the development of Alzheimer׳s disease. The present review focuses on the expression and function of insulin, IGFs and their receptors in the brain in physiological and pathological conditions. Copyright © 2014 Elsevier B.V. and ECNP. All rights reserved.

  19. DNA homologous recombination factor SFR1 physically and functionally interacts with estrogen receptor alpha.

    Directory of Open Access Journals (Sweden)

    Yuxin Feng

    Full Text Available Estrogen receptor alpha (ERα, a ligand-dependent transcription factor, mediates the expression of its target genes by interacting with corepressors and coactivators. Since the first cloning of SRC1, more than 280 nuclear receptor cofactors have been identified, which orchestrate target gene transcription. Aberrant activity of ER or its accessory proteins results in a number of diseases including breast cancer. Here we identified SFR1, a protein involved in DNA homologous recombination, as a novel binding partner of ERα. Initially isolated in a yeast two-hybrid screen, the interaction of SFR1 and ERα was confirmed in vivo by immunoprecipitation and mammalian one-hybrid assays. SFR1 co-localized with ERα in the nucleus, potentiated ER's ligand-dependent and ligand-independent transcriptional activity, and occupied the ER binding sites of its target gene promoters. Knockdown of SFR1 diminished ER's transcriptional activity. Manipulating SFR1 expression by knockdown and overexpression revealed a role for SFR1 in ER-dependent and -independent cancer cell proliferation. SFR1 differs from SRC1 by the lack of an intrinsic activation function. Taken together, we propose that SFR1 is a novel transcriptional modulator for ERα and a potential target in breast cancer therapy.

  20. The transcription factor ERG increases expression of neurotransmitter receptors on prostate cancer cells

    International Nuclear Information System (INIS)

    Kissick, Haydn T.; On, Seung T.; Dunn, Laura K.; Sanda, Martin G.; Asara, John M.; Pellegrini, Kathryn L.; Noel, Jonathan K.; Arredouani, Mohamed S.

    2015-01-01

    The TMPRSS2-ERG gene fusion occurs in about half of prostate cancer (PCa) cases and results in overexpression of the transcription factor ERG. Overexpression of ERG has many effects on cellular function. However, how these changes enhance cell growth and promote tumor development is unclear. To investigate the role of ERG, LNCaP and PC3 cells were transfected with ERG and gene expression and metabolic profile were analyzed. Our data show that expression of ERG induces overexpression of many nicotinicacetylcholine receptors (nAChRs). In addition, metabolic profiling by LC-MS/MS revealed elevated production of several neurotransmitters in cells expressing ERG. Consistently, treatment of ERG-expressing cells with nicotine induced elevated calcium influx, GSK3β (Ser9) phosphorylation and cell proliferation. Finally, we show that PCa patientswho are smokers have larger tumors if their tumors are TMPRSS2-ERG gene fusion positive. Collectively, our data suggest that ERG sensitizes prostate tumor cells to neurotransmitter receptor agonists like nicotine. The online version of this article (doi:10.1186/s12885-015-1612-3) contains supplementary material, which is available to authorized users

  1. Characterization of the receptors for mycobacterial cord factor in Guinea pig.

    Directory of Open Access Journals (Sweden)

    Kenji Toyonaga

    Full Text Available Guinea pig is a widely used animal for research and development of tuberculosis vaccines, since its pathological disease process is similar to that present in humans. We have previously reported that two C-type lectin receptors, Mincle (macrophage inducible C-type lectin, also called Clec4e and MCL (macrophage C-type lectin, also called Clec4d, recognize the mycobacterial cord factor, trehalose-6,6'-dimycolate (TDM. Here, we characterized the function of the guinea pig homologue of Mincle (gpMincle and MCL (gpMCL. gpMincle directly bound to TDM and transduced an activating signal through ITAM-bearing adaptor molecule, FcRγ. Whereas, gpMCL lacked C-terminus and failed to bind to TDM. mRNA expression of gpMincle was detected in the spleen, lymph nodes and peritoneal macrophages and it was strongly up-regulated upon stimulation of zymosan and TDM. The surface expression of gpMincle was detected on activated macrophages by a newly established monoclonal antibody that also possesses a blocking activity. This antibody potently suppressed TNF production in BCG-infected macrophages. Collectively, gpMincle is the TDM receptor in the guinea pig and TDM-Mincle axis is involved in host immune responses against mycobacteria.

  2. Characterization of the receptors for mycobacterial cord factor in Guinea pig.

    Science.gov (United States)

    Toyonaga, Kenji; Miyake, Yasunobu; Yamasaki, Sho

    2014-01-01

    Guinea pig is a widely used animal for research and development of tuberculosis vaccines, since its pathological disease process is similar to that present in humans. We have previously reported that two C-type lectin receptors, Mincle (macrophage inducible C-type lectin, also called Clec4e) and MCL (macrophage C-type lectin, also called Clec4d), recognize the mycobacterial cord factor, trehalose-6,6'-dimycolate (TDM). Here, we characterized the function of the guinea pig homologue of Mincle (gpMincle) and MCL (gpMCL). gpMincle directly bound to TDM and transduced an activating signal through ITAM-bearing adaptor molecule, FcRγ. Whereas, gpMCL lacked C-terminus and failed to bind to TDM. mRNA expression of gpMincle was detected in the spleen, lymph nodes and peritoneal macrophages and it was strongly up-regulated upon stimulation of zymosan and TDM. The surface expression of gpMincle was detected on activated macrophages by a newly established monoclonal antibody that also possesses a blocking activity. This antibody potently suppressed TNF production in BCG-infected macrophages. Collectively, gpMincle is the TDM receptor in the guinea pig and TDM-Mincle axis is involved in host immune responses against mycobacteria.

  3. Regulation of granulocyte colony-stimulating factor receptor-mediated granulocytic differentiation by C-mannosylation.

    Science.gov (United States)

    Otani, Kei; Niwa, Yuki; Suzuki, Takehiro; Sato, Natsumi; Sasazawa, Yukiko; Dohmae, Naoshi; Simizu, Siro

    2018-04-06

    Granulocyte colony-stimulating factor (G-CSF) receptor (G-CSFR) is a type I cytokine receptor which is involved in hematopoietic cell maturation. G-CSFR has three putative C-mannosylation sites at W253, W318, and W446; however, it is not elucidated whether G-CSFR is C-mannosylated or not. In this study, we first demonstrated that G-CSFR was C-mannosylated at only W318. We also revealed that C-mannosylation of G-CSFR affects G-CSF-dependent downstream signaling through changing ligand binding capability but not cell surface localization. Moreover, C-mannosylation of G-CSFR was functional and regulated granulocytic differentiation in myeloid 32D cells. In conclusion, we found that G-CSFR is C-mannosylated at W318 and that this C-mannosylation has role(s) for myeloid cell differentiation through regulating downstream signaling. Copyright © 2018 Elsevier Inc. All rights reserved.

  4. Targeting Epidermal Growth Factor Receptor-Related Signaling Pathways in Pancreatic Cancer.

    Science.gov (United States)

    Philip, Philip A; Lutz, Manfred P

    2015-10-01

    Pancreatic cancer is aggressive, chemoresistant, and characterized by complex and poorly understood molecular biology. The epidermal growth factor receptor (EGFR) pathway is frequently activated in pancreatic cancer; therefore, it is a rational target for new treatments. However, the EGFR tyrosine kinase inhibitor erlotinib is currently the only targeted therapy to demonstrate a very modest survival benefit when added to gemcitabine in the treatment of patients with advanced pancreatic cancer. There is no molecular biomarker to predict the outcome of erlotinib treatment, although rash may be predictive of improved survival; EGFR expression does not predict the biologic activity of anti-EGFR drugs in pancreatic cancer, and no EGFR mutations are identified as enabling the selection of patients likely to benefit from treatment. Here, we review clinical studies of EGFR-targeted therapies in combination with conventional cytotoxic regimens or multitargeted strategies in advanced pancreatic cancer, as well as research directed at molecules downstream of EGFR as alternatives or adjuncts to receptor targeting. Limitations of preclinical models, patient selection, and trial design, as well as the complex mechanisms underlying resistance to EGFR-targeted agents, are discussed. Future clinical trials must incorporate translational research end points to aid patient selection and circumvent resistance to EGFR inhibitors.

  5. Epidermal growth factor receptor coexpression modulates susceptibility to Herceptin in HER2/neu overexpressing breast cancer cells via specific erbB-receptor interaction and activation

    International Nuclear Information System (INIS)

    Diermeier, Simone; Horvath, Gabor; Knuechel-Clarke, Ruth; Hofstaedter, Ferdinand; Szoellosi, Janos; Brockhoff, Gero

    2005-01-01

    Background: Growth factors and Herceptin specifically and differentially modulate cell proliferation of tumor cells. However, the mechanism of action on erbB-receptor level is incompletely understood. We evaluated Herceptin's capacity to modulate erbB-receptor activation and interaction on the cell surface level and thereby potentially impair cell proliferation of HER2/neu (c-erbB2) overexpressing breast cancer cells, both in the presence and absence of relevant growth factors. Methods: BT474 and SK-BR-3 breast cancer cell lines were treated with Epidermal Growth Factor (EGF), Heregulin, and with Herceptin in different combinations. Kinetics of cell proliferation were evaluated flow cytometrically based on BrdU-labeling. Fluorescence Resonance Energy Transfer, ELISAs and phosphorylation site specific Western Blotting was performed to investigate erbB-receptor interaction and activation. Results: EGF induced EGFR/EGFR and EGFR/c-erbB2 interactions correlate with stimulation of cell proliferation in BT474 cells. Both homo- and heterodimerization are considerably less pronounced in SK-BR-3 cells and heterointeraction is additionally reduced by EGF treatment, causing inhibition of cell proliferation. Heregulin stimulates cell proliferation extensively in both cell lines. Herceptin drives BT474 cells more efficiently into quiescence than it does with SK-BR-3 cells and thereby blocks cell cycle progress. In SK-BR-3 Herceptin treatment causes c-erbB2 phosphorylation of Y877 and Y1248, EGF induces Y877 and Y1112 phosphorylation. The Y1112 phosphorylation site, activated by EGF in SK-BR-3 cell, is bypassed in BT474. In addition the inhibitory capacity of Herceptin on BT474 and SK-BR-3 cell proliferation depends on the presence and absence of growth factors to a various extent. Conclusion: The growth inhibitory effect of Herceptin on c-erbB2 overexpressing breast cancer cells is considerably modulated by EGFR coexpression and consequently EGFR/c-erbB2 homo- and

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

    LENUS (Irish Health Repository)

    Gleeson, Eimear M

    2013-07-19

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

  7. Increased Eps15 homology domain 1 and RAB11FIP3 expression regulate breast cancer progression via promoting epithelial growth factor receptor recycling.

    Science.gov (United States)

    Tong, Dandan; Liang, Ya-Nan; Stepanova, A A; Liu, Yu; Li, Xiaobo; Wang, Letian; Zhang, Fengmin; Vasilyeva, N V

    2017-02-01

    Recent research indicates that the C-terminal Eps15 homology domain 1 is associated with epithelial growth factor receptor-mediated endocytosis recycling in non-small-cell lung cancer. The aim of this study was to determine the clinical significance of Eps15 homology domain 1 gene expression in relation to phosphorylation of epithelial growth factor receptor expression in patients with breast cancer. Primary breast cancer samples from 306 patients were analyzed for Eps15 homology domain 1, RAB11FIP3, and phosphorylation of epithelial growth factor receptor expression via immunohistochemistry. The clinical significance was assessed via a multivariate Cox regression analysis, Kaplan-Meier curves, and the log-rank test. Eps15 homology domain 1 and phosphorylation of epithelial growth factor receptor were upregulated in 60.46% (185/306) and 53.92% (165/306) of tumor tissues, respectively, as assessed by immunohistochemistry. The statistical correlation analysis indicated that Eps15 homology domain 1 overexpression was positively correlated with the increases in phosphorylation of epithelial growth factor receptor ( r = 0.242, p breast cancer for the overall survival in the total, chemotherapy, and human epidermal growth factor receptor 2 (-) groups. However, the use of combined expression of Eps15 homology domain 1 and phosphorylation of epithelial growth factor receptor markers is more effective for the disease-free survival in the overall population, chemotherapy, and human epidermal growth factor receptor 2 (-) groups. Moreover, the combined markers are also significant prognostic markers of breast cancer in the human epidermal growth factor receptor 2 (+), estrogen receptor (+), and estrogen receptor (-) groups. Eps15 homology domain 1 has a tumor suppressor function, and the combined marker of Eps15 homology domain 1/phosphorylation of epithelial growth factor receptor expression was identified as a better prognostic marker in breast cancer diagnosis

  8. Single-domain antibodies that compete with the natural ligand fibroblast growth factor block the internalization of the fibroblast growth factor receptor 1

    Energy Technology Data Exchange (ETDEWEB)

    Veggiani, Gianluca; Ossolengo, Giuseppe; Aliprandi, Marisa; Cavallaro, Ugo [IFOM-IEO Campus, Via Adamello 16, 20139 Milano (Italy); Marco, Ario de, E-mail: ario.demarco@ung.si [IFOM-IEO Campus, Via Adamello 16, 20139 Milano (Italy); Dept. Environmental Sciences, University of Nova Gorica (UNG), Vipavska 13, P.O. Box 301-SI-5000, Rozna Dolina, Nova Gorica (Slovenia)

    2011-05-20

    Highlights: {yields} Recombinant antibodies for FGFR1 were isolated from a llama naive library in VHH format. {yields} These antibodies compete with the natural ligand FGF-2 for the same epitope on FGFR1. {yields} The antibody competition inhibits the FGF-2-dependent internalization of FGFR1. -- Abstract: Single-domain antibodies in VHH format specific for fibroblast growth factor receptor 1 (FGFR1) were isolated from a phage-display llama naive library. In particular, phage elution in the presence of the natural receptor ligand fibroblast growth factor (FGF) allowed for the identification of recombinant antibodies that compete with FGF for the same region on the receptor surface. These antibodies posses a relatively low affinity for FGFR1 and were never identified when unspecific elution conditions favoring highly affine binders were applied to panning procedures. Two populations of competitive antibodies were identified that labeled specifically the receptor-expressing cells in immunofluorescence and recognize distinct epitopes. Antibodies from both populations effectively prevented FGF-dependent internalization and nuclear accumulation of the receptor in cultured cells. This achievement indicates that these antibodies have a capacity to modulate the receptor physiology and, therefore, constitute powerful reagents for basic research and a potential lead for therapeutic applications.

  9. Single-domain antibodies that compete with the natural ligand fibroblast growth factor block the internalization of the fibroblast growth factor receptor 1

    International Nuclear Information System (INIS)

    Veggiani, Gianluca; Ossolengo, Giuseppe; Aliprandi, Marisa; Cavallaro, Ugo; Marco, Ario de

    2011-01-01

    Highlights: → Recombinant antibodies for FGFR1 were isolated from a llama naive library in VHH format. → These antibodies compete with the natural ligand FGF-2 for the same epitope on FGFR1. → The antibody competition inhibits the FGF-2-dependent internalization of FGFR1. -- Abstract: Single-domain antibodies in VHH format specific for fibroblast growth factor receptor 1 (FGFR1) were isolated from a phage-display llama naive library. In particular, phage elution in the presence of the natural receptor ligand fibroblast growth factor (FGF) allowed for the identification of recombinant antibodies that compete with FGF for the same region on the receptor surface. These antibodies posses a relatively low affinity for FGFR1 and were never identified when unspecific elution conditions favoring highly affine binders were applied to panning procedures. Two populations of competitive antibodies were identified that labeled specifically the receptor-expressing cells in immunofluorescence and recognize distinct epitopes. Antibodies from both populations effectively prevented FGF-dependent internalization and nuclear accumulation of the receptor in cultured cells. This achievement indicates that these antibodies have a capacity to modulate the receptor physiology and, therefore, constitute powerful reagents for basic research and a potential lead for therapeutic applications.

  10. Aberrant Receptor Internalization and Enhanced FRS2-dependent Signaling Contribute to the Transforming Activity of the Fibroblast Growth Factor Receptor 2 IIIb C3 Isoform*

    OpenAIRE

    Cha, Jiyoung Y.; Maddileti, Savitri; Mitin, Natalia; Harden, T. Kendall; Der, Channing J.

    2009-01-01

    Alternative splice variants of fibroblast growth factor receptor 2 (FGFR2) IIIb, designated C1, C2, and C3, possess progressive reduction in their cytoplasmic carboxyl termini (822, 788, and 769 residues, respectively), with preferential expression of the C2 and C3 isoforms in human cancers. We determined that the progressive deletion of carboxyl-terminal sequences correlated with increasing transforming potency. The highly transforming C3 variant lacks five tyrosine r...

  11. 99m Tc-anti-epidermal growth factor receptor nanobody for tumor imaging.

    Science.gov (United States)

    Piramoon, Majid; Hosseinimehr, Seyed Jalal; Omidfar, Kobra; Noaparast, Zohreh; Abedi, Seyed Mohammad

    2017-04-01

    Nanobodies are important biomolecules for tumor targeting. In this study, we synthesized and labeled anti-epidermal growth factor receptor (EGFR) nanobody OA-cb6 with 99m Tc(CO) 3 + and evaluated its characteristics for targeting the EGFR in the A431 human epidermal carcinoma cell line. Nanobody radiolabeling was achieved with high yield and radiochemical purity, and the radioconjugate was stable. Biodistribution results in nude mice exhibited a favorable tumor-to-muscle ratio at 4-hr postinjection, and tumor location was visualized at 4 hr after injection of radiolabeled nanobody. Our result showed that the OA-cb6- 99m Tc-tricarbonyl radiolabeled nanobody is a promising radiolabeled biomolecule for tumor imaging in cancers with high EGFR overexpression. © 2016 John Wiley & Sons A/S.

  12. No evidence for a role of the serotonin 4 receptor in five-factor personality traits

    DEFF Research Database (Denmark)

    Stenbæk, Dea Siggaard; Dam, Vibeke Høyrup; Fisher, Patrick MacDonald

    2017-01-01

    Serotonin (5-HT) brain architecture appears to be implicated in normal personality traits as supported by genetic associations and studies using molecular brain imaging. However, so far, no studies have addressed potential contributions to variation in normal personality traits from in vivo...... serotonin 4 receptor (5-HT4R) brain availability, which has recently become possible to image with Positron Emission Tomography (PET). This is particularly relevant since availability of 5-HT4R has been shown to adapt to synaptic levels of 5-HT and thus offers information about serotonergic tone...... in the healthy brain. In 69 healthy participants (18 females), the associations between personality traits assessed with the five-factor NEO Personality Inventory-Revised (NEO PI-R) and regional cerebral 5-HT4R binding in neocortex, amygdala, hippocampus, and anterior cingulate cortex (ACC) were investigated...

  13. Urokinase plasminogen activator receptor on invasive cancer cells: A prognostic factor in distal gastric adenocarcinoma

    DEFF Research Database (Denmark)

    Alpizar, Warner Enrique Alpizar; Christensen, Ib Jarle; Santoni-Rugiu, Eric

    2012-01-01

    Gastric cancer is the second cancer causing death worldwide. The five-year survival for this malignancy is below 25% and few parameters have shown an impact on the prognosis of the disease. The receptor for urokinase plasminogen activator (uPAR) is involved in extracellular matrix degradation...... by mediating cell surface associated plasminogen activation, and its presence on gastric cancer cells is linked to micrometastasis and poor prognosis. Using immunohistochemistry, the prognostic significance of uPAR was evaluated in tissue samples from a retrospective series of 95 gastric cancer patients. u...... association between the expression of uPAR on tumor cells in the peripheral invasion zone and overall survival of gastric cancer patients (HR = 2.16; 95% CI: 1.13-4.14; p = 0.02). Multivariate analysis showed that uPAR immunoreactivity in cancer cells at the invasive front is an independent prognostic factor...

  14. Vascular Endothelial Growth Factor Receptor 3 Controls Neural Stem Cell Activation in Mice and Humans

    Directory of Open Access Journals (Sweden)

    Jinah Han

    2015-02-01

    Full Text Available Neural stem cells (NSCs continuously produce new neurons within the adult mammalian hippocampus. NSCs are typically quiescent but activated to self-renew or differentiate into neural progenitor cells. The molecular mechanisms of NSC activation remain poorly understood. Here, we show that adult hippocampal NSCs express vascular endothelial growth factor receptor (VEGFR 3 and its ligand VEGF-C, which activates quiescent NSCs to enter the cell cycle and generate progenitor cells. Hippocampal NSC activation and neurogenesis are impaired by conditional deletion of Vegfr3 in NSCs. Functionally, this is associated with compromised NSC activation in response to VEGF-C and physical activity. In NSCs derived from human embryonic stem cells (hESCs, VEGF-C/VEGFR3 mediates intracellular activation of AKT and ERK pathways that control cell fate and proliferation. These findings identify VEGF-C/VEGFR3 signaling as a specific regulator of NSC activation and neurogenesis in mammals.

  15. Molecular interactions between chondroitin-dermatan sulfate and growth factors/receptors/matrix proteins.

    Science.gov (United States)

    Mizumoto, Shuji; Yamada, Shuhei; Sugahara, Kazuyuki

    2015-10-01

    Recent functional studies on chondroitin sulfate-dermatan sulfate (CS-DS) demonstrated its indispensable roles in various biological events including brain development and cancer. CS-DS proteoglycans exert their physiological activity through interactions with specific proteins including growth factors, cell surface receptors, and matrix proteins. The characterization of these interactions is essential for regulating the biological functions of CS-DS proteoglycans. Although amino acid sequences on the bioactive proteins required for these interactions have already been elucidated, the specific saccharide sequences involved in the binding of CS-DS to target proteins have not yet been sufficiently identified. In this review, recent findings are described on the interaction between CS-DS and some proteins which are especially involved in the central nervous system and cancer development/metastasis. Copyright © 2015. Published by Elsevier Ltd.

  16. Upregulation of vascular endothelial growth factor receptor-1 contributes to sevoflurane preconditioning–mediated cardioprotection

    Directory of Open Access Journals (Sweden)

    Qian B

    2018-04-01

    Full Text Available Bin Qian,1 Yang Yang,2 Yusheng Yao,3 Yanling Liao,3 Ying Lin3 1Department of Anesthesiology, People’s Hospital Affiliated to Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian, China; 2Department of Anesthesiology, West China Hospital, Sichuan University, Chengdu, Sichuan, China; 3Department of Anesthesiology, The Shengli Clinical Medical College, Fujian Medical University, Fuzhou, Fujian, China Purpose: Sevoflurane preconditioning (SPC can provide myocardial protective effects similar to ischemic preconditioning. However, the exact mechanism of SPC remains unclear. Previous studies indicate that vascular endothelial growth factor receptor 1 (VEGFR-1 is involved in ischemic preconditioning-mediated cardioprotection. This study was designed to determine the significance of VEGFR-1 signaling in SPC-mediated cardioprotection.Materials and methods: Myocardial ischemia–reperfusion (I/R rat model was established using the Langendorff isolated heart perfusion apparatus. Additionally, after 15 min of baseline equilibration, the isolated hearts were pretreated with 2.5% sevoflurane, 2.5% sevoflurane+MF1 10 µmol/L, or 2.5% sevoflurane+placental growth factor 10 µmol/L, and then subjected to 30 min of global ischemia and 120 min of reperfusion. The changes in hemodynamic parameters, myocardial infarct size, and the levels of creatine kinase-MB, lactate dehydrogenase, cardiac troponin-I, tumor necrosis factor-α, and interleukin 6 in the myocardium were evaluated.Results: Compared to the I/R group, pretreatment with 2.5% sevoflurane significantly improved the cardiac function, limited myocardial infarct size, reduced cardiac enzyme release, upregulated VEGFR-1 expression, and decreased inflammation. In addition, the selective VEGFR-1 agonist, placental growth factor, did not enhance the cardioprotection and anti-inflammation effects of sevoflurane, while the specific VEGFR-1 inhibitor, MF1, completely reversed these effects

  17. Mechanisms of Inhibition of the Epidermal Growth Factor Receptor: Implications for Novel Anti-Cancer Therapies

    National Research Council Canada - National Science Library

    Klein, Daryl E

    2005-01-01

    .... No secreted or extracellular ErbB receptor inhibitors have been reported in mammals. However, two natural inhibitors of the highly homologous Drosophila EGF receptor are found in Drosophila melanogaster...

  18. Epidermal Growth Factor Receptor Activating Mutations in Squamous Histology of Lung Cancer Patients of Southern Bulgaria

    Directory of Open Access Journals (Sweden)

    Genova Silvia N.

    2015-12-01

    Full Text Available There is only limited data on the prevalence of epidermal growth factor receptor (EGFR activating mutations in squamous cell carcinomas and adenosquamous carcinomas of the lung in patients of the Southern Bulgarian region and the efficacy of EGFR tyrosine kinase inhibitors. AIM: Previous reports for Bulgarian population showed high incidence of EGFR mutations in the squamous cell carcinomas, so we set the goal to investigate their frequency in Southern Bulgaria, after precise immunohistochemical verification of lung cancers. MATERIALS AND METHODS: Two hundred and thirty-six lung carcinomas were included in this prospective study. All biopsies were initially analysed with p63, TTF1, Napsin A, CK7, CK34βE12, synaptophysin, CK20 and CDX2. Two hundred and twenty-five non-small cell lung carcinomas were studied with real-time PCR technology to assess the status of the EGFR gene. RESULTS: We detected 132 adenocarcinomas (58.7%, 89 squamous cell carcinomas (39.2%, 4 adenosquamous carcinomas (1.8%, 9 large cell neuroendocrine carcinomas (3.8% and 2 metastatic colorectal adenocarcinomas (0.8%. Activating mutations in the EGF receptor had 3 out of 89 squamous cell carcinomas (3.37%. We have established mutations in L858R, deletion in exon 19 and rare mutation in S7681. One out of four adenosquamous carcinomas had a point mutation in the L858R (25%. CONCLUSIONS: The frequency of EGFR mutations we found in lung squamous cell carcinomas in a Southern Bulgarian region is lower than that in European countries. Ethnic diversity in the region does not play role of an independent predictive factor in terms of mutation frequency.

  19. Retinal hypoxia induces vascular endothelial growth factor through induction of estrogen-related receptor γ

    Energy Technology Data Exchange (ETDEWEB)

    Do, Ji Yeon; Choi, Young Keun [Leading-edge Research Center for Drug Discovery and Development for Diabetes and Metabolic Disease, Kyungpook National University School of Medicine, Kyungpook National University, Daegu (Korea, Republic of); Kook, Hyun [Department of Pharmacology, Chonnam National University Medical School, Gwangju (Korea, Republic of); Suk, Kyoungho [Department of Pharmacology, Brain Science & Engineering Institute, Kyungpook National University School of Medicine, Daegu (Korea, Republic of); Lee, In-Kyu [Leading-edge Research Center for Drug Discovery and Development for Diabetes and Metabolic Disease, Kyungpook National University School of Medicine, Kyungpook National University, Daegu (Korea, Republic of); Division of Endocrinology and Metabolism, Department of Internal Medicine, Research Institute of Aging and Metabolism, Kyungpook National University School of Medicine, Daegu (Korea, Republic of); Park, Dong Ho, E-mail: sarasate2222@gmail.com [Department of Ophthalmology, Kyungpook National University School of Medicine, Daegu (Korea, Republic of)

    2015-05-01

    Ischemic retinopathies causing overexpression of pro-angiogenic factors, including vascular endothelial growth factor (VEGF), are the most common cause of blindness. Thus, understanding the pathophysiology of targetable pathways that regulate retinal VEGF is of great interest. A conserved binding site for estrogen-related receptor γ (ERRγ) has been identified in the promoter of the Vegfa gene. ERRγ is a constitutively active orphan nuclear receptor and its expression is increased by hypoxic stimuli in metabolically active tissues. This study evaluated the role of ERRγ in the ischemic retina and the anti-VEGF potential of GSK5182, a selective inverse agonist of ERRγ. In an oxygen-induced retinopathy (OIR) mouse model, immunohistochemistry showed significantly increased ERRγ expression in the ganglion cell layer at postnatal day (P) 17. In a ganglion cell line (RGC-5), mRNA and protein levels of ERRγ were increased by desferrioxamine treatment and hypoxic conditions (1% O{sub 2}). Transient transfection of RGC-5 cells revealed that ERRγ regulated Vegfa expression and this was inhibited by GSK5182. Intravitreal injection of GSK5182 into the OIR model at P14 inhibited retinal Vegfa mRNA expression at P17. GSK5182 suppresses hypoxia-induced VEGF expression via ERRγ; therefore, ERRγ could be a treatment target for ischemic retinopathies. - Highlights: • OIR mice exhibited increased ERRγ expression in the ganglion cell layer. • Hypoxia-induced ERRγ expression was observed in retinal ganglion cells. • ERRγ overexpression increased VEGFA expression in retinal ganglion cells. • An ERRγ inverse agonist suppressed VEGFA expression in retinal ganglion cells. • Intravitreal injection of an ERRγ inverse agonist suppressed VEGFA in OIR mice.

  20. Molecular Cloning and Characterization of Growth Factor Receptor Bound-Protein in Clonorchis sinensis

    Science.gov (United States)

    Bai, Xuelian; Lee, Ji-Yun; Kim, Tae Im; Dai, Fuhong; Lee, Tae-Jin; Hong, Sung-Jong

    2014-01-01

    Background Clonorchis sinensis causes clonorchiasis, a potentially serious disease. Growth factor receptor-bound protein 2 (Grb2) is a cytosolic protein conserved among animals and plays roles in cellular functions such as meiosis, organogenesis and energy metabolism. In the present study, we report first molecular characters of growth factor receptor bound-protein (CsGrb2) from C. sinensis as counter part of Grb2 from animals and its possible functions in development and organogenesis of C. sinensis. Methodology/Principal Findings A CsGrb2 cDNA clone retrieved from the C. sinensis transcriptome encoded a polypeptide with a SH3-SH2-SH3 structure. Recombinant CsGrb2 was bacterially produced and purified to homogeneity. Native CsGrb2 with estimated molecular weight was identified from C. sinensis adult extract by western blotting using a mouse immune serum to recombinant CsGrb2. CsGrb2 transcripts was more abundant in the metacercariae than in the adults. Immunohistochemical staining showed that CsGrb2 was localized to the suckers, mesenchymal tissues, sperms in seminal receptacle and ovary in the adults, and abundantly expressed in most organs of the metacercariae. Recombinant CsGrb2 was evaluated to be little useful as a serodiagnostic reagent for C. sinesis human infections. Conclusion Grb2 protein found in C. sinensis was conserved among animals and suggested to play a role in the organogenesis, energy metabolism and mitotic spermatogenesis of C. sinensis. These findings from C. sinensis provide wider understanding on diverse function of Grb2 in lower animals such as platyhelminths. PMID:24454892

  1. Molecular cloning and characterization of growth factor receptor bound-protein in Clonorchis sinensis.

    Directory of Open Access Journals (Sweden)

    Xuelian Bai

    Full Text Available BACKGROUND: Clonorchis sinensis causes clonorchiasis, a potentially serious disease. Growth factor receptor-bound protein 2 (Grb2 is a cytosolic protein conserved among animals and plays roles in cellular functions such as meiosis, organogenesis and energy metabolism. In the present study, we report first molecular characters of growth factor receptor bound-protein (CsGrb2 from C. sinensis as counter part of Grb2 from animals and its possible functions in development and organogenesis of C. sinensis. METHODOLOGY/PRINCIPAL FINDINGS: A CsGrb2 cDNA clone retrieved from the C. sinensis transcriptome encoded a polypeptide with a SH3-SH2-SH3 structure. Recombinant CsGrb2 was bacterially produced and purified to homogeneity. Native CsGrb2 with estimated molecular weight was identified from C. sinensis adult extract by western blotting using a mouse immune serum to recombinant CsGrb2. CsGrb2 transcripts was more abundant in the metacercariae than in the adults. Immunohistochemical staining showed that CsGrb2 was localized to the suckers, mesenchymal tissues, sperms in seminal receptacle and ovary in the adults, and abundantly expressed in most organs of the metacercariae. Recombinant CsGrb2 was evaluated to be little useful as a serodiagnostic reagent for C. sinesis human infections. CONCLUSION: Grb2 protein found in C. sinensis was conserved among animals and suggested to play a role in the organogenesis, energy metabolism and mitotic spermatogenesis of C. sinensis. These findings from C. sinensis provide wider understanding on diverse function of Grb2 in lower animals such as platyhelminths.

  2. Inhibition of fibroblast growth factor receptor with AZD4547 mitigates juvenile nasopharyngeal angiofibroma.

    Science.gov (United States)

    Le, Tran; New, Jacob; Jones, Joel W; Usman, Shireen; Yalamanchali, Sreeya; Tawfik, Ossama; Hoover, Larry; Bruegger, Dan E; Thomas, Sufi Mary

    2017-10-01

    Juvenile nasopharyngeal angiofibroma (JNA) is a benign tumor that presents in adolescent males. Although surgical excision is the mainstay of treatment, recurrences complicate treatment. There is a need to develop less invasive approaches for management. JNA tumors are composed of fibroblasts and vascular endothelial cells. We identified fibroblast growth factor receptor (FGFR) and vascular endothelial growth factor (VEGF) expression in JNA-derived fibroblasts. FGFR influences fibroblast proliferation and VEGF is necessary for angiogenesis. We hypothesized that targeting FGFR would mitigate JNA fibroblast proliferation, invasion, and migration, and that targeting the VEGF receptor would attenuate endothelial tubule formation. After informed consent, fibroblasts from JNA explants of 3 patients were isolated. Fibroblasts were treated with FGFR inhibitor AZD4547, 0 to 25 μg/mL for 72 hours and proliferation was quantified using CyQuant assay. Migration and invasion of JNA were assessed using 24-hour transwell assays with subsequent fixation and quantification. Mitigation of FGFR and downstream signaling was evaluated by immunoblotting. Tubule formation was assessed in human umbilical vein endothelial cells (HUVECs) treated with vehicle control (dimethylsulfoxide [DMSO]) or semaxanib (SU5416) as well as in serum-free media (SFM) or JNA conditioned media (CM). Tubule length was compared between treatment groups. Compared to control, AZD4547 inhibited JNA fibroblast proliferation, migration, and invasion through inhibition of FGFR and downstream signaling, specifically phosphorylation of - p44/42 mitogen activated protein kinase (p44/42 MAPK). JNA fibroblast CM significantly increased HUVEC tubule formation (p = 0.0039). AZD4547 effectively mitigates FGFR signaling and decreases JNA fibroblast proliferation, migration, and invasion. SU5416 attenuated JNA fibroblast-induced tubule formation. AZD4547 may have therapeutic potential in the treatment of JNA. © 2017 ARS

  3. Retinal hypoxia induces vascular endothelial growth factor through induction of estrogen-related receptor γ

    International Nuclear Information System (INIS)

    Do, Ji Yeon; Choi, Young Keun; Kook, Hyun; Suk, Kyoungho; Lee, In-Kyu; Park, Dong Ho

    2015-01-01

    Ischemic retinopathies causing overexpression of pro-angiogenic factors, including vascular endothelial growth factor (VEGF), are the most common cause of blindness. Thus, understanding the pathophysiology of targetable pathways that regulate retinal VEGF is of great interest. A conserved binding site for estrogen-related receptor γ (ERRγ) has been identified in the promoter of the Vegfa gene. ERRγ is a constitutively active orphan nuclear receptor and its expression is increased by hypoxic stimuli in metabolically active tissues. This study evaluated the role of ERRγ in the ischemic retina and the anti-VEGF potential of GSK5182, a selective inverse agonist of ERRγ. In an oxygen-induced retinopathy (OIR) mouse model, immunohistochemistry showed significantly increased ERRγ expression in the ganglion cell layer at postnatal day (P) 17. In a ganglion cell line (RGC-5), mRNA and protein levels of ERRγ were increased by desferrioxamine treatment and hypoxic conditions (1% O 2 ). Transient transfection of RGC-5 cells revealed that ERRγ regulated Vegfa expression and this was inhibited by GSK5182. Intravitreal injection of GSK5182 into the OIR model at P14 inhibited retinal Vegfa mRNA expression at P17. GSK5182 suppresses hypoxia-induced VEGF expression via ERRγ; therefore, ERRγ could be a treatment target for ischemic retinopathies. - Highlights: • OIR mice exhibited increased ERRγ expression in the ganglion cell layer. • Hypoxia-induced ERRγ expression was observed in retinal ganglion cells. • ERRγ overexpression increased VEGFA expression in retinal ganglion cells. • An ERRγ inverse agonist suppressed VEGFA expression in retinal ganglion cells. • Intravitreal injection of an ERRγ inverse agonist suppressed VEGFA in OIR mice

  4. Stage specific requirement of platelet-derived growth factor receptor-α in embryonic development.

    Directory of Open Access Journals (Sweden)

    Chen Qian

    Full Text Available Platelet-derived growth factor receptor alpha (PDGFRα is a cell-surface receptor tyrosine kinase for platelet-derived growth factors. Correct timing and level of Pdgfra expression is crucial for embryo development, and deletion of Pdgfra caused developmental defects of multiple endoderm and mesoderm derived structures, resulting in a complex phenotypes including orofacial cleft, spina bifida, rib deformities, and omphalocele in mice. However, it is not clear if deletion of Pdgfra at different embryonic stages differentially affects these structures.To address the temporal requirement of Pdgfra in embryonic development.We have deleted the Pdgfra in Pdgfra-expressing tissues at different embryonic stages in mice, examined and quantified the developmental anomalies.Current study showed that (i conditional deletion of Pdgfra at different embryonic days (between E7.5 and E10.5 resulted in orofacial cleft, spina bifida, rib cage deformities, and omphalocele, and (ii the day of Pdgfra deletion influenced the combinations, incidence and severities of these anomalies. Deletion of Pdgfra caused apoptosis of Pdgfra-expressing tissues, and developmental defects of their derivatives.Orofacial cleft, spina bifida and omphalocele are among the commonest skeletal and abdominal wall defects of newborns, but their genetic etiologies are largely unknown. The remarkable resemblance of our conditional Pdgfra knockout embryos to theses human congenital anomalies, suggesting that dysregulated PDGFRA expression could cause these anomalies in human. Future work should aim at defining (a the regulatory elements for the expression of the human PDGFRA during embryonic development, and (b if mutations / sequence variations of these regulatory elements cause these anomalies.

  5. Epidermal growth factor treatment of A431 cells alters the binding capacity and electrophoretic mobility of the cytoskeletally associated epidermal growth factor receptor

    International Nuclear Information System (INIS)

    Roy, L.M.; Gittinger, C.K.; Landreth, G.E.

    1991-01-01

    Epidermal growth factor receptor interacts with structural elements of A431 cells and remains associated with the cytoskeleton following extraction with nonionic detergents. Extraction of cells with 0.15% Triton X-100 resulted in detection of only approximately 40% of the EGF binding sites on the cytoskeleton. If the cells were exposed to EGF prior to extraction, approximately twofold higher levels of low-affinity EGF binding sites were detected. The difference in number of EGF binding sites was not a consequence of differences in numbers of EGF receptors associated with the cytoskeleton; equal amounts of 35S-labeled receptor were immunoprecipitated from the cytoskeletons of both control and EGF-treated cells. The effect of EGF pretreatment on binding activity was coincident with a change in the mobility of the receptor from a doublet of Mr approximately 160-180 kDa to a single sharp band at 180 kDa. The alteration in receptor mobility was not a simple consequence of receptor phosphorylation in that the alteration was not reversed by alkaline phosphatase treatment, nor was the shift produced by treatment of the cells with phorbol ester. The two EGF receptor species demonstrated differential susceptibility to V8 proteinase digestion. The EGF-induced 180 kDa species was preferentially digested by the proteinase relative to the 160 kDa species, indicating that EGF binding results in a conformational change in the receptor. The EGF-mediated preservation of binding activity and altered conformation may be related to receptor oligomerization

  6. Structure and function of the Juxta membrane domain of the human epidermal growth factor receptor by NMR spectroscopy

    International Nuclear Information System (INIS)

    Choowongkomon, Kiattawee; Carlin, Cathleen; Sonnichsen, Frank D.

    2005-10-01

    The epidermal growth factor receptor (EGFR) is a member of the receptor tyrosine kinase family involved in the regulation of cellular proliferation and differentiation. Its juxta membrane domain (JX), the region located between the transmembrane and kinase domains, plays important roles in receptor trafficking since both basolateral sorting in polarized epithelial cells and lysosomal sorting signals are identified in this region. In order to understand the regulation of these signals, we characterized the structural properties of recombinant JX domain in dodecyl phosphocholine detergent (DPC) by nuclear magnetic resonance (NMR) spectroscopy. In DPC micelles, structures derived from NMR data showed three amphipathic, helical segments. Two equivalent average structural models on the surface of micelles were obtained that differ only in the relative orientation between the first and second helices. Our data suggests that the activity of sorting signals may be regulated by their membrane association and restricted accessibility in the intact receptor

  7. Transmembrane signalling at the epidermal growth factor receptor. Positive regulation by the C-terminal phosphotyrosine residues

    DEFF Research Database (Denmark)

    Magni, M; Pandiella, A; Helin, K

    1991-01-01

    a positive role in the regulation of transmembrane signalling at the EGF receptor. The stepwise decrease in signal generation observed in single, double and triple point mutants suggest that the role of phosphotyrosine residues is not in the participation in specific amino acid sequences, but rather...... in the double and the triple mutants. In the latter mutant, expression of the EGF-receptor-activated lipolytic enzyme phospholipase C gamma was unchanged, whereas its tyrosine phosphorylation induced by the growth factor was lowered to approx. 25% of that in the controls. In all of the cell clones employed......, the accumulation of inositol phosphates induced by treatment with fetal calf serum varied only slightly, whereas the same effect induced by EGF was consistently lowered in those lines expressing mutated receptors. This decrease was moderate for those receptors missing only the distal tyrosine (point and deletion...

  8. Frequency of Epidermal Growth Factor Receptor Mutation in Smokers with Lung Cancer Without Pulmonary Emphysema.

    Science.gov (United States)

    Takeda, Kenichi; Yamasaki, Akira; Igishi, Tadashi; Kawasaki, Yuji; Ito-Nishii, Shizuka; Izumi, Hiroki; Sakamoto, Tomohiro; Touge, Hirokazu; Kodani, Masahiro; Makino, Haruhiko; Yanai, Masaaki; Tanaka, Natsumi; Matsumoto, Shingo; Araki, Kunio; Nakamura, Hiroshige; Shimizu, Eiji

    2017-02-01

    Chronic obstructive pulmonary disease is a smoking-related disease, and is categorized into the emphysema and airway dominant phenotypes. We examined the relationship between emphysematous changes and epidermal growth factor receptor (EGFR) mutation status in patients with lung adenocarcinoma. The medical records for 250 patients with lung adenocarcinoma were retrospectively reviewed. All patients were categorized into the emphysema or non-emphysema group. Wild-type EGFR was detected in 136 (54%) and mutant EGFR in 48 (19%). Emphysematous changes were observed in 87 (36%) patients. EGFR mutation was highly frequent in the non-emphysema group (p=0.0014). Multivariate logistic regression analysis showed that emphysema was an independent risk factor for reduced frequency of EGFR mutation (Odds Ratio=3.47, p=0.005). Our data showed a relationship between emphysematous changes and EGFR mutation status. There might be mutually exclusive genetic risk factors for carcinogenesis and development of emphysematous changes. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

  9. Tumor necrosis factor-alpha induces activation of coagulation and fibrinolysis in baboons through an exclusive effect on the p55 receptor

    NARCIS (Netherlands)

    van der Poll, T.; Jansen, P. M.; van Zee, K. J.; Welborn, M. B.; de Jong, I.; Hack, C. E.; Loetscher, H.; Lesslauer, W.; Lowry, S. F.; Moldawer, L. L.

    1996-01-01

    Tumor necrosis factor-alpha (TNF-alpha) can bind to two distinct transmembrane receptors, the p55 and p75 TNF receptors. We compared the capability of two mutant TNF proteins with exclusive affinity for the p55 or p75 TNF receptor with that of wild type TNF, to activate the hemostatic mechanism in

  10. From bench to bedside: What do we know about hormone receptor-positive and human epidermal growth factor receptor 2-positive breast cancer?

    Science.gov (United States)

    Wu, Victoria Shang; Kanaya, Noriko; Lo, Chiao; Mortimer, Joanne; Chen, Shiuan

    2015-09-01

    Breast cancer is a heterogeneous disease. Thanks to extensive efforts from research scientists and clinicians, treatment for breast cancer has advanced into the era of targeted medicine. With the use of several well-established biomarkers, such as hormone receptors (HRs) (i.e., estrogen receptor [ER] and progesterone receptor [PgR]) and human epidermal growth factor receptor-2 (HER2), breast cancer patients can be categorized into multiple subgroups with specific targeted treatment strategies. Although therapeutic strategies for HR-positive (HR+) HER2-negative (HER2-) breast cancer and HR-negative (HR-) HER2-positive (HER2+) breast cancer are well-defined, HR+ HER2+ breast cancer is still an overlooked subgroup without tailored therapeutic options. In this review, we have summarized the molecular characteristics, etiology, preclinical tools and therapeutic options for HR+ HER2+ breast cancer. We hope to raise the attention of both the research and the medical community on HR+ HER2+ breast cancer, and to advance patient care for this subtype of disease. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Diagnostic values of vascular endothelial growth factor and epidermal growth factor receptor for benign and malignant hydrothorax.

    Science.gov (United States)

    Gu, Yan; Zhang, Min; Li, Guo-Hua; Gao, Jun-Zhen; Guo, Liping; Qiao, Xiao-Juan; Wang, Li-Hong; He, Lan; Wang, Mei-Ling; Yan, Li; Fu, Xiu-Hua

    2015-02-05

    Hydrothorax, as one of the common complications of malignant tumors, still cannot be sensitively detected in clinical practice, thus requiring a sensitive, specific method for diagnosis. The aim of this study was to analyze the correlation between levels of vascular endothelial growth factor (VEGF) and epidermal growth factor receptor (EGFR) in patients with benign and malignant hydrothorax. The contents of VEGF in the pleural effusion and serum of the patients with malignant pleural effusion (n = 35) and benign pleural effusion (n = 30) were detected by double antibody sandwich enzyme linked immunosorbent assay. The gene copy number level of EGFR in pleural effusion was detected by fluorescence in situ hybridization (FISH). The points with the highest sensitivity and specificity were selected as the critical values to calculate the diagnostic value of the VEGF in pleural effusion and serum, and EGFR gene copy number in pleural effusion. The contents of VEGF in pleural effusion and serum of patients with malignant hydrothorax were (384.91 ± 120.18), and (129.62 ± 46.35) ng/L, respectively, which were significantly higher than those of the patients with benign hydrothorax (207.97 ± 64.04), (63.49 ± 24.58) ng/L (P benign and malignant hydrothorax. The sensitivity and specificity of serum were 74.3% and 96.7%, respectively (the boundary value was 99.21 ng/L) for diagnosing benign and malignant hydrothorax. The diagnostic efficiencies of EGFR and VEGF in hydrothorax were similar. There was a significant correlation between EGFR and VEGF in hydrothorax (P benign and malignant pleural effusions, which contributed to differential diagnosis results of benign and malignant pleural effusions. It is feasible to detect the gene copy number of the pleural effusion cell mass EGFR by FISH technique. Joint detection can improve the diagnostic sensitivity.

  12. Analysis of the epidermal growth factor receptor specific transcriptome: effect of receptor expression level and an activating mutation

    DEFF Research Database (Denmark)

    Pedersen, Mikkel W; Pedersen, Nina; Damstrup, Lars

    2005-01-01

    moderately expressed or overexpressed at an in-itself transforming level. These changes were compared to those induced by the naturally occurring constitutively active variant EGFRvIII. This study provides novel insight on the activities and mechanisms of EGFRvIII and EGFR mediated transformation, as genes...... by interferons. Expression of this module was absent in the EGFRvIII-expressing cell line and the parental cell line. Treatment with the specific EGFR inhibitor AG1478 indicated that the regulations were primary, receptor-mediated events. Furthermore, activation of this module correlated with activation of STAT1...

  13. Tyrosine dephosphorylation enhances the therapeutic target activity of epidermal growth factor receptor (EGFR) by disrupting its interaction with estrogen receptor (ER).

    Science.gov (United States)

    Ma, Shao; Yin, Ning; Qi, Xiaomei; Pfister, Sandra L; Zhang, Mei-Jie; Ma, Rong; Chen, Guan

    2015-05-30

    Protein-protein interactions can increase or decrease its therapeutic target activity and the determining factors involved, however, are largely unknown. Here, we report that tyrosine-dephosphorylation of epidermal growth factor receptor (EGFR) increases its therapeutic target activity by disrupting its interaction with estrogen receptor (ER). Protein tyrosine phosphatase H1 (PTPH1) dephosphorylates the tyrosine kinase EGFR, disrupts its interaction with the nuclear receptor ER, and increases breast cancer sensitivity to small molecule tyrosine kinase inhibitors (TKIs). These effects require PTPH1 catalytic activity and its interaction with EGFR, suggesting that the phosphatase may increase the sensitivity by dephosphorylating EGFR leading to its dissociation with ER. Consistent with this notion, a nuclear-localization defective ER has a higher EGFR-binding activity and confers the resistance to TKI-induced growth inhibition. Additional analysis show that PTPH1 stabilizes EGFR, stimulates the membranous EGFR accumulation, and enhances the growth-inhibitory activity of a combination therapy of TKIs with an anti-estrogen. Since EGFR and ER both are substrates for PTPH1 in vitro and in intact cells, these results indicate that an inhibitory EGFR-ER protein complex can be switched off through a competitive enzyme-substrate binding. Our results would have important implications for the treatment of breast cancer with targeted therapeutics.

  14. Identification and Functional Characterisation of Nod Factor Receptor (NFR) Paralogs in Lotus japonicus

    DEFF Research Database (Denmark)

    Vestergaard, Gitte; Radutoiu, Elena Simona; Stougaard, Jens

    an important missing link in plant-bacterial communication. This picture changed with the cloning of LysM-domain containing receptor-like kinases (LysM-RLKs) in different legume species. In Lotus japonicus, two LysM-RLKs, Nod Factor Receptor 1 (NFR1) and Nod Factor Receptor 5 (NFR5), are believed to bind Nod...... using the sequences of NFR1 and NFR5. Microsattelite markers were developed from each TAC clone containing the LysM-RLK, permitting us to locate the genes on a genetic map of Lotus japonicus. In order to get more insight into the function of these genes an inverse genetic approach using RNAi has been...

  15. Systemic factors related to soluble (prorenin receptor in plasma of patients with proliferative diabetic retinopathy.

    Directory of Open Access Journals (Sweden)

    Keitaro Hase

    Full Text Available (Prorenin receptor [(PRR], a new component of the tissue renin-angiotensin system (RAS, plays a crucial role in inflammation and angiogenesis in the eye, thus contributing to the development of proliferative diabetic retinopathy (PDR. In this study, we investigated systemic factors related to plasma levels of soluble form of (PRR [s(PRR] in patients with PDR. Twenty type II diabetic patients with PDR and 20 age-matched, non-diabetic patients with idiopathic macular diseases were enrolled, and plasma levels of various molecules were measured by enzyme-linked immunosorbent assays. Human retinal microvascular endothelial cells were stimulated with several diabetes-related conditions to evaluate changes in gene expression using real-time quantitative PCR. Of various systemic parameters examined, the PDR patients had significantly higher blood sugar and serum creatinine levels than non-diabetic controls. Protein levels of s(PRR, prorenin, tumor necrosis factor (TNF-α, complement factor D (CFD, and leucine-rich α-2-glycoprotein 1 (LRG1 significantly increased in the plasma of PDR subjects as compared to non-diabetes, with positive correlations detected between s(PRR and these inflammatory molecules but not prorenin. Estimated glomerular filtration rate and serum creatinine were also correlated with plasma s(PRR, but not prorenin, levels. Among the inflammatory molecules correlated with s(PRR in the plasma, TNF-α, but not CFD or LRG1, application to retinal endothelial cells upregulated the mRNA expression of (PRR but not prorenin, while stimulation with high glucose enhanced both (PRR and prorenin expression. These findings suggested close relationships between plasma s(PRR and diabetes-induced factors including chronic inflammation, renal dysfunction, and hyperglycemia in patients with PDR.

  16. Matrix metalloproteinase-3, vitamin D receptor gene polymorphisms, and occupational risk factors in lumbar disc degeneration.

    Science.gov (United States)

    Zawilla, N H; Darweesh, H; Mansour, N; Helal, S; Taha, F M; Awadallah, M; El Shazly, R

    2014-06-01

    Lumbar disc degeneration (LDD) is a process that begins early in life, contributing to the development of low back pain. LDD is a consequence of a variety of factors, and its etiology remains poorly understood. Objectives to investigate occupational and genetic risk factors inducing lumbar disc degeneration, and to evaluate the possible association of genetic polymorphisms of matrix metalloproteinase 3 (MMP-3) and vitamin D receptor (VDR) with the severity of LDD in an Egyptian population. A case control study involving 84 LDD and 60 controls was carried out. Five types of work related factors were investigated by questionnaire, complete neurological examination for all subjects and MRI for the cases. Polymerase chain reaction and restriction fragment length polymorphism methods were applied to detect polymorphisms in MMP-3 Promoter (-1,171 6A/5A) (rs 731236) and VDR-Apa (rs 35068180). We found that family history, back injury, smoking, high level of sitting, bending/twisting, physical workload, lifting, whole body vibration, mutant allele 5A of MMP-3 and mutant allele T of VDR were significantly associated with LDD (OR = 2.9, 3.1, 2.1, 11.1, 15.9, 11.7, 8.2, 12.6, 2.5 and 3.1 respectively, p < 0.05). Cases that carry allele 5A and/or allele T were associated with LDD severity. LDD is closely associated in occurrence and severity with occupational, environmental risk factors and susceptibility genes namely MMP-3, and VDR (ApaI). This study throws light on the importance of screening for early detection of susceptible individuals and disease prevention.

  17. Expression of tumor necrosis factor-alpha and receptor I(P55in pterygium

    Directory of Open Access Journals (Sweden)

    Bing Wu

    2014-06-01

    Full Text Available AIM:To observe the expression of tumor necrosis factor- alpha(TNF-αand its receptor I(P55in different pterygium and discuss the role of TNF-α and receptor I(P55in pterygium.METHODS: Immunohistochemistical staining method(PVwas adopted to detect the expression of TNF-α and receptor I in pterygium(72 eyesand para-pterygium conjunctival tissue(30 eyes. The relationship between the expression and clinical-pathological parameters was also analyzed. RESULTS: The positive rates of TNF-α were 65.3%(47/72, 26.7%(8/30in pterygium and para-pterygium conjunctival tissue. The positive expression of TNF-α had statistic difference between the two groups(χ2=12.706, Pχ2=13.875, Pχ2=6.547, P=0.011. There had no statistically significance of the expression intensity between the two groups(F=1.288, P=0.393; the positive rate in advanced pterygium group was higher than quiescent pterygium group(χ2=4.082, P=0.043. The expression intensity had no statistically significance between the two groups(F=0.489, P=0.708. The positive rate of P55 in recurrent pterygium group was higher than primary pterygium group(χ2=9.907, P=0.002. There had no statistically significance of the two group's expression intensity(F=1.175, P=0.424; the positive rate in advanced pterygium group was higher than in quiescent pterygium group(χ2=11.140, P=0.001. The expression intensity had no statistically significance between the two groups(F=0.665, P=0.621. CONCLUSION:The expression of TNF-α and P55 are changing according to the development of clinical staging and onset. The expression of TNF-α and P55 may be related to clinical classification, staging and patient's working conditions of pterygium. There has no significant difference expression intensity of TNF-α and P55 in clinical staging and onset of pterygium.

  18. Vascular endothelial growth factor receptor-3 directly interacts with phosphatidylinositol 3-kinase to regulate lymphangiogenesis.

    Directory of Open Access Journals (Sweden)

    Sanja Coso

    Full Text Available BACKGROUND: Dysfunctional lymphatic vessel formation has been implicated in a number of pathological conditions including cancer metastasis, lymphedema, and impaired wound healing. The vascular endothelial growth factor (VEGF family is a major regulator of lymphatic endothelial cell (LEC function and lymphangiogenesis. Indeed, dissemination of malignant cells into the regional lymph nodes, a common occurrence in many cancers, is stimulated by VEGF family members. This effect is generally considered to be mediated via VEGFR-2 and VEGFR-3. However, the role of specific receptors and their downstream signaling pathways is not well understood. METHODS AND RESULTS: Here we delineate the VEGF-C/VEGF receptor (VEGFR-3 signaling pathway in LECs and show that VEGF-C induces activation of PI3K/Akt and MEK/Erk. Furthermore, activation of PI3K/Akt by VEGF-C/VEGFR-3 resulted in phosphorylation of P70S6K, eNOS, PLCγ1, and Erk1/2. Importantly, a direct interaction between PI3K and VEGFR-3 in LECs was demonstrated both in vitro and in clinical cancer specimens. This interaction was strongly associated with the presence of lymph node metastases in primary small cell carcinoma of the lung in clinical specimens. Blocking PI3K activity abolished VEGF-C-stimulated LEC tube formation and migration. CONCLUSIONS: Our findings demonstrate that specific VEGFR-3 signaling pathways are activated in LECs by VEGF-C. The importance of PI3K in VEGF-C/VEGFR-3-mediated lymphangiogenesis provides a potential therapeutic target for the inhibition of lymphatic metastasis.

  19. Targeting Insulin-Like Growth Factor 1 Receptor Inhibits Pancreatic Cancer Growth and Metastasis

    Science.gov (United States)

    Subramani, Ramadevi; Lopez-Valdez, Rebecca; Arumugam, Arunkumar; Nandy, Sushmita; Boopalan, Thiyagarajan; Lakshmanaswamy, Rajkumar

    2014-01-01

    Pancreatic cancer is one of the most lethal cancers. Increasing incidence and mortality indicates that there is still much lacking in detection and management of the disease. This is partly due to a lack of specific symptoms during early stages of the disease. Several growth factor receptors have been associated with pancreatic cancer. Here, we have investigated if an RNA interference approach targeted to IGF-IR could be effective and efficient against pancreatic cancer growth and metastasis. For that, we evaluated the effects of IGF-1R inhibition using small interfering RNA (siRNAs) on tumor growth and metastasis in HPAC and PANC-1 pancreatic cancer cell lines. We found that silencing IGF-1R inhibits pancreatic cancer growth and metastasis by blocking key signaling pathways such AKT/PI3K, MAPK, JAK/STAT and EMT. Silencing IGF-1R resulted in an anti-proliferative effect in PANC-1 and HPAC pancreatic cancer cell lines. Matrigel invasion, transwell migration and wound healing assays also revealed a role for IGF-1R in metastatic properties of pancreatic cancer. These results were further confirmed using Western blotting analysis of key intermediates involved in proliferation, epithelial mesenchymal transition, migration, and invasion. In addition, soft agar assays showed that silencing IGF-1R also blocks the colony forming capabilities of pancreatic cancer cells in vitro. Western blots, as well as, flow cytometric analysis revealed the induction of apoptosis in IGF-1R silenced cells. Interestingly, silencing IGF-1R also suppressed the expression of insulin receptor β. All these effects together significantly control pancreatic cancer cell growth and metastasis. To conclude, our results demonstrate the significance of IGF-1R in pancreatic cancer. PMID:24809702

  20. Osteoblast-specific transcription factor Osterix increases vitamin D receptor gene expression in osteoblasts.

    Directory of Open Access Journals (Sweden)

    Chi Zhang

    Full Text Available Osterix (Osx is an osteoblast-specific transcription factor required for osteoblast differentiation from mesenchymal stem cells. In Osx knock-out mice, no bone formation occurs. The vitamin D receptor (VDR is a member of the nuclear hormone receptor superfamily that regulates target gene transcription to ensure appropriate control of calcium homeostasis and bone development. Here, we provide several lines of evidence that show that the VDR gene is a target for transcriptional regulation by Osx in osteoblasts. For example, calvaria obtained from Osx-null embryos displayed dramatic reductions in VDR expression compared to wild-type calvaria. Stable overexpression of Osx stimulated VDR expression in C2C12 mesenchymal cells. Inhibition of Osx expression by siRNA led to downregulation of VDR. In contrast, Osx levels remained unchanged in osteoblasts in VDR-null mice. Mechanistic approaches using transient transfection assays showed that Osx directly activated a 1 kb fragment of the VDR promoter in a dose-dependent manner. To define the region of the VDR promoter that was responsive to Osx, a series of VDR promoter deletion mutants were examined and the minimal Osx-responsive region was refined to the proximal 120 bp of the VDR promoter. Additional point mutants were used to identify two GC-rich regions that were responsible for VDR promoter activation by Osx. Chromatin immunoprecipitation assays demonstrated that endogenous Osx was associated with the native VDR promoter in primary osteoblasts in vivo. Cumulatively, these data strongly support a direct regulatory role for Osx in VDR gene expression. They further provide new insight into potential mechanisms and pathways that Osx controls in osteoblasts and during the process of osteoblastic cell differentiation.

  1. The pluripotency factor Nanog is directly upregulated by the androgen receptor in prostate cancer cells.

    Science.gov (United States)

    Kregel, Steven; Szmulewitz, Russell Z; Vander Griend, Donald J

    2014-11-01

    The Androgen Receptor (AR) is a nuclear hormone receptor that functions as a critical oncogene in all stages of prostate cancer progression, including progression to castration-resistance following androgen-deprivation therapy. Thus, identifying and targeting critical AR-regulated genes is one potential method to block castration-resistant cancer proliferation. Of particular importance are transcription factors that regulate stem cell pluripotency; many of these genes are emerging as critical oncogenes in numerous tumor cell types. Of these, Nanog has been previously shown to increase the self-renewal and stem-like properties of prostate cancer cells. Thus, we hypothesized that Nanog is a candidate AR target gene that may impart castration-resistance. We modulated AR signaling in LNCaP prostate cancer cells and assayed for Nanog expression. Direct AR binding to the NANOG promoter was tested using AR Chromatin Immunoprecipation (ChIP) and analyses of publically available AR ChIP-sequencing data-sets. Nanog over-expressing cells were analyzed for cell growth and cytotoxicity in response to the AR antagonist enzalutamide and the microtubule stabilizing agent docetaxel. AR signaling upregulates Nanog mRNA and protein. AR binds directly to the NANOG promoter, and was not identified within 75 kb of the NANOGP8 pseudogene, suggesting the NANOG gene locus was preferentially activated. Nanog overexpression in LNCaP cells increases overall growth, but does not increase resistance to enzalutamide or docetaxel. Nanog is a novel oncogenic AR target gene in prostate cancer cells, and stable expression of Nanog increases proliferation and growth of prostate cancer cells, but not resistance to enzalutamide or docetaxel. © 2014 Wiley Periodicals, Inc.

  2. Insulin like growth factor 2 regulation of aryl hydrocarbon receptor in MCF-7 breast cancer cells

    International Nuclear Information System (INIS)

    Tomblin, Justin K.; Salisbury, Travis B.

    2014-01-01

    Highlights: •IGF-2 stimulates concurrent increases in AHR and CCND1 expression. •IGF-2 promotes the binding of AHR to the endogenous cyclin D1 promoter. •AHR knockdown inhibits IGF-2 stimulated increases in CCND1 mRNA and protein. •AHR knockdown inhibits IGF-2 stimulated increases in MCF-7 proliferation. -- Abstract: Insulin like growth factor (IGF)-1 and IGF-2 stimulate normal growth, development and breast cancer cell proliferation. Cyclin D1 (CCND1) promotes cell cycle by inhibiting retinoblastoma protein (RB1). The aryl hydrocarbon receptor (AHR) is a major xenobiotic receptor that also regulates cell cycle. The purpose of this study was to investigate whether IGF-2 promotes MCF-7 breast cancer proliferation by inducing AHR. Western blot and quantitative real time PCR (Q-PCR) analysis revealed that IGF-2 induced an approximately 2-fold increase (P < .001) in the expression of AHR and CCND1. Chromatin immunoprecipitation (ChIP), followed by Q-PCR indicated that IGF-2 promoted (P < .001) a 7-fold increase in AHR binding on the CCND1 promoter. AHR knockdown significantly (P < .001) inhibited IGF-2 stimulated increases in CCND1 mRNA and protein. AHR knockdown cells were less (P < .001) responsive to the proliferative effects of IGF-2 than control cells. Collectively, our findings have revealed a new regulatory mechanism by which IGF-2 induction of AHR promotes the expression of CCND1 and the proliferation of MCF-7 cells. This previously uncharacterized pathway could be important for the proliferation of IGF responsive cancer cells that also express AHR

  3. Insulin like growth factor 2 regulation of aryl hydrocarbon receptor in MCF-7 breast cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Tomblin, Justin K.; Salisbury, Travis B., E-mail: salisburyt@marshall.edu

    2014-01-17

    Highlights: •IGF-2 stimulates concurrent increases in AHR and CCND1 expression. •IGF-2 promotes the binding of AHR to the endogenous cyclin D1 promoter. •AHR knockdown inhibits IGF-2 stimulated increases in CCND1 mRNA and protein. •AHR knockdown inhibits IGF-2 stimulated increases in MCF-7 proliferation. -- Abstract: Insulin like growth factor (IGF)-1 and IGF-2 stimulate normal growth, development and breast cancer cell proliferation. Cyclin D1 (CCND1) promotes cell cycle by inhibiting retinoblastoma protein (RB1). The aryl hydrocarbon receptor (AHR) is a major xenobiotic receptor that also regulates cell cycle. The purpose of this study was to investigate whether IGF-2 promotes MCF-7 breast cancer proliferation by inducing AHR. Western blot and quantitative real time PCR (Q-PCR) analysis revealed that IGF-2 induced an approximately 2-fold increase (P < .001) in the expression of AHR and CCND1. Chromatin immunoprecipitation (ChIP), followed by Q-PCR indicated that IGF-2 promoted (P < .001) a 7-fold increase in AHR binding on the CCND1 promoter. AHR knockdown significantly (P < .001) inhibited IGF-2 stimulated increases in CCND1 mRNA and protein. AHR knockdown cells were less (P < .001) responsive to the proliferative effects of IGF-2 than control cells. Collectively, our findings have revealed a new regulatory mechanism by which IGF-2 induction of AHR promotes the expression of CCND1 and the proliferation of MCF-7 cells. This previously uncharacterized pathway could be important for the proliferation of IGF responsive cancer cells that also express AHR.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-09-09

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

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

    International Nuclear Information System (INIS)

    Faria, Jerusa A.Q.A.; Andrade, Carolina de; Goes, Alfredo M.; Rodrigues, Michele A.; Gomes, Dawidson A.

    2016-01-01

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

  6. Comparative Biochemical and Functional Analysis of Viral and Human Secreted Tumor Necrosis Factor (TNF) Decoy Receptors*

    Science.gov (United States)

    Pontejo, Sergio M.; Alejo, Ali; Alcami, Antonio

    2015-01-01

    The blockade of tumor necrosis factor (TNF) by etanercept, a soluble version of the human TNF receptor 2 (hTNFR2), is a well established strategy to inhibit adverse TNF-mediated inflammatory responses in the clinic. A similar strategy is employed by poxviruses, encoding four viral TNF decoy receptor homologues (vTNFRs) named cytokine response modifier B (CrmB), CrmC, CrmD, and CrmE. These vTNFRs are differentially expressed by poxviral species, suggesting distinct immunomodulatory properties. Whereas the human variola virus and mouse ectromelia virus encode one vTNFR, the broad host range cowpox virus encodes all vTNFRs. We report the first comprehensive study of the functional and binding properties of these four vTNFRs, providing an explanation for their expression profile among different poxviruses. In addition, the vTNFRs activities were compared with the hTNFR2 used in the clinic. Interestingly, CrmB from variola virus, the causative agent of smallpox, is the most potent TNFR of those tested here including hTNFR2. Furthermore, we demonstrate a new immunomodulatory activity of vTNFRs, showing that CrmB and CrmD also inhibit the activity of lymphotoxin β. Similarly, we report for the first time that the hTNFR2 blocks the biological activity of lymphotoxin β. The characterization of vTNFRs optimized during virus-host evolution to modulate the host immune response provides relevant information about their potential role in pathogenesis and may be used to improve anti-inflammatory therapies based on soluble decoy TNFRs. PMID:25940088

  7. Comparative Biochemical and Functional Analysis of Viral and Human Secreted Tumor Necrosis Factor (TNF) Decoy Receptors.

    Science.gov (United States)

    Pontejo, Sergio M; Alejo, Ali; Alcami, Antonio

    2015-06-26

    The blockade of tumor necrosis factor (TNF) by etanercept, a soluble version of the human TNF receptor 2 (hTNFR2), is a well established strategy to inhibit adverse TNF-mediated inflammatory responses in the clinic. A similar strategy is employed by poxviruses, encoding four viral TNF decoy receptor homologues (vTNFRs) named cytokine response modifier B (CrmB), CrmC, CrmD, and CrmE. These vTNFRs are differentially expressed by poxviral species, suggesting distinct immunomodulatory properties. Whereas the human variola virus and mouse ectromelia virus encode one vTNFR, the broad host range cowpox virus encodes all vTNFRs. We report the first comprehensive study of the functional and binding properties of these four vTNFRs, providing an explanation for their expression profile among different poxviruses. In addition, the vTNFRs activities were compared with the hTNFR2 used in the clinic. Interestingly, CrmB from variola virus, the causative agent of smallpox, is the most potent TNFR of those tested here including hTNFR2. Furthermore, we demonstrate a new immunomodulatory activity of vTNFRs, showing that CrmB and CrmD also inhibit the activity of lymphotoxin β. Similarly, we report for the first time that the hTNFR2 blocks the biological activity of lymphotoxin β. The characterization of vTNFRs optimized during virus-host evolution to modulate the host immune response provides relevant information about their potential role in pathogenesis and may be used to improve anti-inflammatory therapies based on soluble decoy TNFRs. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  8. Normal epidermal growth factor receptor signaling is dispensable for bone anabolic effects of parathyroid hormone.

    Science.gov (United States)

    Schneider, Marlon R; Dahlhoff, Maik; Andrukhova, Olena; Grill, Jessica; Glösmann, Martin; Schüler, Christiane; Weber, Karin; Wolf, Eckhard; Erben, Reinhold G

    2012-01-01

    Although the bone anabolic properties of intermittent parathyroid hormone (PTH) have long been employed in the treatment of osteoporosis, the molecular mechanisms behind this action remain largely unknown. Previous studies showed that PTH increases the expression and the activity of epidermal growth factor receptor (EGFR) in osteoblasts, and activation of ERK1/2 by PTH in osteoblasts was demonstrated to induce the proteolytical release of EGFR ligands and EGFR transactivation. However, conclusive evidence for an important role of the EGFR system in mediating the anabolic actions of intermittent PTH on bone in vivo is lacking. Here, we evaluated the effects of intermittent PTH on bone in Waved-5 (Wa5) mice which carry an antimorphic Egfr allele whose product acts as a dominant negative receptor. Heterozygous Wa5 females and control littermates received a subcutaneous injection of PTH (80 μg/kg) or buffer on 5 days per week for 4 weeks. Wa5 mice had slightly lower total bone mineral density (BMD), but normal cancellous bone volume and turnover in the distal femoral metaphysis. The presence of the antimorphic Egfr allele neither influenced the PTH-induced increase in serum osteocalcin nor the increases in distal femoral BMD, cortical thickness, cancellous bone volume, and cancellous bone formation rate. Similarly, the PTH-induced rise in lumbar vertebral BMD was unchanged in Wa5 relative to wild-type mice. Wa5-derived osteoblasts showed considerably lower basal extracellular signal-regulated kinase 1/2 (ERK1/2) activation as compared to control osteoblasts. Whereas activation of ERK1/2 by the EGFR ligand amphiregulin was largely blocked in Wa5 osteoblasts, treatment with PTH induced ERK1/2 activation comparable to that observed in control osteoblasts, relative to baseline levels. Our data indicate that impairment of EGFR signaling does not affect the anabolic action of intermittent PTH on cancellous and cortical bone. Copyright © 2011. Published by Elsevier Inc.

  9. Human epidermal growth factor receptor2 expression in unresectable gastric cancers: Relationship with CT characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jeong Sub [Dept. of Radiology, Jeju National University Hospital, Jeju (Korea, Republic of); Kim, Se Hyung; Im, Seock Ah; Kim, Min A; Han, Joon Koo [Seoul National University Hospital, Seoul (Korea, Republic of)

    2017-09-15

    To retrospectively analyze the qualitative CT features that correlate with human epidermal growth factor receptor 2 (HER2)-expression in pathologically-proven gastric cancers. A total of 181 patients with pathologically-proven unresectable gastric cancers with HER2-expression (HER2-positive [n = 32] and negative [n = 149]) were included. CT features of primary gastric and metastatic tumors were reviewed. The prevalence of each CT finding was compared in both groups. Thereafter, binary logistic regression determined the most significant differential CT features. Clinical outcomes were compared using Kaplan-Meier method. HER2-postive cancers showed lower clinical T stage (21.9% vs. 8.1%; p = 0.015), hyperattenuation on portal phase (62.5% vs. 30.9%; p = 0.003), and was more frequently metastasized to the liver (62.5% vs. 32.2%; p = 0.001), than HER2-negative cancers. On binary regression analysis, hyperattenuation of the tumor (odds ratio [OR], 4.68; p < 0.001) and hepatic metastasis (OR, 4.43; p = 0.001) were significant independent factors that predict HER2-positive cancers. Median survival of HER2-positive cancers (13.7 months) was significantly longer than HER2-negative cancers (9.6 months) (p = 0.035). HER2-positive gastric cancers show less-advanced T stage, hyperattenuation on the portal phase, and frequently metastasize to the liver, as compared to HER2-negative cancers.

  10. Optical Molecular Imaging of Epidermal Growth Factor Receptor Expression to Improve Detection of Oral Neoplasia

    Directory of Open Access Journals (Sweden)

    Nitin Nitin

    2009-06-01

    Full Text Available Background: The development of noninvasive molecular imaging approaches has the potential to improve management of cancer. Methods: In this study, we demonstrate the potential of noninvasive topical delivery of an epidermal growth factor-Alexa 647 (EGF-Alexa 647 conjugate to image changes in epidermal growth factor receptor expression associated with oral neoplasia. We report a series of preclinical analyses to evaluate the optical contrast achieved after topical delivery of EGF-Alexa 647 in a variety of model systems, including cells, three-dimensional tissue cultures, and intact human tissue specimens using wide-field and high-resolution fluorescence imaging. Data were collected from 17 different oral cancer patients: eight pairs of normal and abnormal biopsies and nine resected tumors were examined. Results: The EGF-dye conjugate can be uniformly delivered throughout the oral epithelium with a penetration depth exceeding 500 µm and incubation time of less than 30 minutes. After EGF-Alexa 647 incubation, the presence of oral neoplasia is associated with a 1.5- to 6.9-fold increase in fluorescence contrast compared with grossly normal mucosa from the same patient with both wide-field and high-resolution fluorescence imaging. Conclusions: Results illustrate the potential of EGF-targeted fluorescent agents for in vivo molecular imaging, a technique that may aid in the diagnosis and characterization of oral neoplasia and allow real-time detection of tumor margins.

  11. Involvement of Corticotropin-Releasing Factor and Receptors in Immune Cells in Irritable Bowel Syndrome

    Directory of Open Access Journals (Sweden)

    Mahanand Chatoo

    2018-02-01

    Full Text Available Irritable bowel syndrome (IBS is a common functional gastrointestinal disorder defined by ROME IV criteria as pain in the lower abdominal region, which is associated with altered bowel habit or defecation. The underlying mechanism of IBS is not completely understood. IBS seems to be a product of interactions between various factors with genetics, dietary/intestinal microbiota, low-grade inflammation, and stress playing a key role in the pathogenesis of this disease. The crosstalk between the immune system and stress in IBS mechanism is increasingly recognized. Corticotropin-releasing factor (CRF, a major mediator in the stress response, is involved in altered function in GI, including inflammatory processes, colonic transit time, contractile activity, defecation pattern, pain threshold, mucosal secretory function, and barrier functions. This mini review focuses on the recently establish local GI-CRF system, its involvement in modulating the immune response in IBS, and summarizes current IBS animal models and mapping of CRF, CRFR1, and CRFR2 expression in colon tissues. CRF and receptors might be a key molecule involving the immune and movement function via brain–gut axis in IBS.

  12. Relationship between serum response factor and androgen receptor in prostate cancer.

    Science.gov (United States)

    Prencipe, Maria; O'Neill, Amanda; O'Hurley, Gillian; Nguyen, Lan K; Fabre, Aurelie; Bjartell, Anders; Gallagher, William M; Morrissey, Colm; Kay, Elaine W; Watson, R William

    2015-11-01

    Serum response factor (SRF) is an important transcription factor in castrate-resistant prostate cancer (CRPC). Since CRPC is associated with androgen receptor (AR) hypersensitivity, we investigated the relationship between SRF and AR. Transcriptional activity was assessed by luciferase assay. Cell proliferation was measured by MTT and flow cytometry. Protein expression in patients was assessed by immunohistochemistry. To investigate AR involvement in SRF response to androgen, AR expression was down-regulated using siRNA. This resulted in the abrogation of SRF induction post-DHT. Moreover, DHT stimulation failed to induce SRF transcriptional activity in AR-negative PC346 DCC cells, which was only restored following AR over-expression. Next, SRF expression was down-regulated by siRNA, resulting in AR increased transcriptional activity in castrate-resistant LNCaP Abl cells but not in the parental LNCaP. This negative feedback loop in the resistant cells was confirmed by immunohistochemistry which showed a negative correlation between AR and SRF expression in CRPC bone metastases and a positive correlation in androgen-naïve prostatectomies. Cell proliferation was next assessed following SRF inhibition, demonstrating that SRF inhibition is more effective than AR inhibition in castrate-resistant cells. Our data support SRF as a promising therapeutic target in combination with current treatments. © 2015 Wiley Periodicals, Inc.

  13. Human epidermal growth factor receptor2 expression in unresectable gastric cancers: Relationship with CT characteristics

    International Nuclear Information System (INIS)

    Lee, Jeong Sub; Kim, Se Hyung; Im, Seock Ah; Kim, Min A; Han, Joon Koo

    2017-01-01

    To retrospectively analyze the qualitative CT features that correlate with human epidermal growth factor receptor 2 (HER2)-expression in pathologically-proven gastric cancers. A total of 181 patients with pathologically-proven unresectable gastric cancers with HER2-expression (HER2-positive [n = 32] and negative [n = 149]) were included. CT features of primary gastric and metastatic tumors were reviewed. The prevalence of each CT finding was compared in both groups. Thereafter, binary logistic regression determined the most significant differential CT features. Clinical outcomes were compared using Kaplan-Meier method. HER2-postive cancers showed lower clinical T stage (21.9% vs. 8.1%; p = 0.015), hyperattenuation on portal phase (62.5% vs. 30.9%; p = 0.003), and was more frequently metastasized to the liver (62.5% vs. 32.2%; p = 0.001), than HER2-negative cancers. On binary regression analysis, hyperattenuation of the tumor (odds ratio [OR], 4.68; p < 0.001) and hepatic metastasis (OR, 4.43; p = 0.001) were significant independent factors that predict HER2-positive cancers. Median survival of HER2-positive cancers (13.7 months) was significantly longer than HER2-negative cancers (9.6 months) (p = 0.035). HER2-positive gastric cancers show less-advanced T stage, hyperattenuation on the portal phase, and frequently metastasize to the liver, as compared to HER2-negative cancers

  14. Fibroblast growth factor receptor 4 polymorphism is associated with liver cirrhosis in hepatocarcinoma.

    Directory of Open Access Journals (Sweden)

    Ming-Jen Sheu

    Full Text Available Fibroblast growth factor receptor 4 (FGFR4 polymorphisms are positively correlated with tumor progression in numerous malignant tumors. However, the association between FGFR4 genetic variants and the risk of hepatocellular carcinoma (HCC has not yet been determined. In this study, we investigated the potential associations of FGFR4 single nucleotide polymorphisms (SNPs with HCC susceptibility and its clinicopathological characteristics.Four SNPs in FGFR4 (rs1966265, rs351855, rs2011077, and rs7708357 were analyzed among 884 participants, including 595 controls and 289 patients with HCC. The samples were further analyzed to clarify the associations between these gene polymorphisms and the risk of HCC, and the impact of these SNPs on the susceptibility and clinicopathological characteristics of HCC. After adjusting for other covariants, HCC patients who carrying at least one A genotype (GA and AA at rs351855 were observed to have a higher risk of liver cirrhosis compared with those carrying the wild-type genotype (GG (OR: 2.113, 95% CI: 1.188-3.831. Moreover, the patients with at least one A genotype were particularly showed a high level of alpha-fetoprotein (AFP.Our findings suggest that genetic polymorphism in FGFR4 rs351855 may be associated with the risk of HCC coupled with liver cirrhosis and may markedly increase the AFP level in Taiwanese patients with HCC. In addition, this is the first study that evaluated the risk factors associated with FGFR4 polymorphism variants in Taiwanese patients with HCC.

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

    International Nuclear Information System (INIS)

    Gradishar, William J

    2016-01-01

    Community-based oncologists are faced with challenges and opportunities when delivering quality patient care, including high patient volumes and diminished resources; however, there may be the potential to deliver increased patient education and subsequently improve outcomes. This review discusses the treatment of postmenopausal women with endocrine-resistant, hormone receptor-positive, human epidermal growth factor receptor 2- negative advanced breast cancer in order to illustrate considerations in the provision of pertinent quality education in the treatment of these patients and the management of therapy-related adverse events. An overview of endocrine-resistant breast cancer and subsequent treatment challenges is also provided. Approved treatment options for endocrine-resistant breast cancer include hormonal therapies and mammalian target of rapamycin inhibitors. Compounds under clinical investigation are also discussed

  16. Nutrition, anthropometry, gastrointestinal dysfunction, and circulating levels of tumour necrosis factor alpha receptor I and interleukin-1 receptor antagonist in children during stem cell transplantation

    DEFF Research Database (Denmark)

    Andreassen, B. U.; Pærregaard, Anders; Michaelsen, Kim F.

    2008-01-01

    To evaluate anthropometry, nutrition and gastrointestinal dysfunction, and to characterize the relation between these parameters and the inflammatory activity evaluated by plasma levels of soluble tumour necrosis factor alpha receptor I (sTNFRI) and interleukin-1 receptor antagonist (IL-1Ra) levels...... during stem cell transplantation (SCT) in children. Clinical assessments and blood sampling were performed on days -3, 0, +7, +15 and +31 in eight children undergoing SCT. Energy intake, anthropometry, gastrointestinal dysfunction (WHO toxicity score) and sTNFRI and IL-1Ra were evaluated. The energy...... intake was below recommended levels. There was a loss of lean body mass (arm muscle area)(median, 2031 mm(2) (day -3) vs 1477 mm(2) (day 31); p = 0.04), and of fat mass (arm fat area) (791 mm(2) (day -3) vs 648 mm(2) (day +31); p = 0.04). sTNFRI was elevated throughout the course of transplantation...

  17. Structural analogs of human insulin-like growth factor I with reduced affinity for serum binding proteins and the type 2 insulin-like growth factor receptor

    International Nuclear Information System (INIS)

    Bayne, M.L.; Applebaum, J.; Chicchi, G.G.; Hayes, N.S.; Green, B.G.; Cascieri, M.A.

    1988-01-01

    Four structural analogs of human insulin-like growth factor I (hIGF-I) have been prepared by site-directed mutagenesis of a synthetic IGF-I gene and subsequent expression and purification of the mutant protein from the conditioned media of transformed yeast. [Phe -1 , Val 1 , Asn 2 , Gln 3 , His 4 , Ser 8 , His 9 , Glu 12 , Tyr 15 , Leu 16 ]IGF-I (B-chain mutant), in which the first 16 amino acids of hIGF-I were replaced with the first 17 amino acids of the B-chain of insulin, has >1000-, 100-, and 2-fold reduced potency for human serum binding proteins, the rat liver type 2 IGF receptor, and the human placental type 1 IGF receptor, respectively. The B-chain mutant also has 4-fold increased affinity for the human placental insulin receptor. [Gln 3 , Ala 4 ] IGF-I has 4-fold reduced affinity for human serum binding proteins, but is equipotent to hIGF-I at the types 1 and 2 IGF and insulin receptors. [Tyr 15 , Leu 16 ] IGH-I has 4-fold reduced affinity for human serum binding proteins and 10-fold increased affinity for the insulin receptor. The peptide in which these four-point mutations are combined, [Gln 3 , Ala 4 , Tyr 15 ,Leu 16 ]IGF-I, has 600-fold reduced affinity for the serum binding proteins. All four of these mutants stimulate DNA synthesis in the rat vascular smooth muscle cell line A10 with potencies reflecting their potency at the type 1 IGF receptor. These studies identify some of the domains of hIGF-I which are responsible for maintaining high affinity binding with the serum binding protein and the type 2 IGF receptor. In addition, These peptides will be useful in defining the role of the type 2 IGF receptor and serum binding proteins in the physiological actions of hIGF-I

  18. Tumor necrosis factor α sensitizes spinal cord TRPV1 receptors to the endogenous agonist N-oleoyldopamine

    Directory of Open Access Journals (Sweden)

    Spicarova Diana

    2010-08-01

    Full Text Available Abstract Modulation of synaptic transmission in the spinal cord dorsal horn is thought to be involved in the development and maintenance of different pathological pain states. The proinflamatory cytokine, tumor necrosis factor α (TNFα, is an established pain modulator in both the peripheral and the central nervous system. Up-regulation of TNFα and its receptors (TNFR in dorsal root ganglion (DRG cells and in the spinal cord has been shown to play an important role in neuropathic and inflammatory pain conditions. Transient receptor potential vanilloid 1 (TRPV1 receptors are known as molecular integrators of nociceptive stimuli in the periphery, but their role on the spinal endings of nociceptive DRG neurons is unclear. The endogenous TRPV1 receptor agonist N-oleoyldopamine (OLDA was shown previously to activate spinal TRPV1 receptors. In our experiments the possible influence of TNFα on presynaptic spinal cord TRPV1 receptor function was investigated. Using the patch-clamp technique, miniature excitatory postsynaptic currents (mEPSCs were recorded in superficial dorsal horn neurons in acute slices after incubation with 60 nM TNFα. A population of dorsal horn neurons with capsaicin sensitive primary afferent input recorded after the TNFα pretreatment had a basal mEPSC frequency of 1.35 ± 0.20 Hz (n = 13, which was significantly higher when compared to a similar population of neurons in control slices (0.76 ± 0.08 Hz; n = 53; P

  19. Cell-cell adhesion mediated by binding of membrane-anchored transforming growth factor α to epidermal growth factor receptors promotes cell proliferation

    International Nuclear Information System (INIS)

    Anklesaria, P.; Greenberger, J.S.; Teixido, J.; Laiho, M.; Massague, J.; Pierce, J.H.

    1990-01-01

    The precursor for transforming growth factor α, pro-TGF-α, is a cell surface glycoprotein that can establish contact with epidermal growth factor (EGF) receptors on adjacent cells. To examine whether the pro-TGF-α/EGF receptor pair can simultaneously mediate cell adhesion and promote cell proliferation, the authors have expressed pro-TGF-α in a bone marrow stromal cell line labeled with [ 35 S] cysteine. Expression of pro-TGF-α allows these cells to support long-term attachment of an EGF/interleukin-3-dependent hematopoietic progenitor cell line that expresses EGF receptors but is unable to adhere to normal stroma. This interaction is inhibited by soluble EGF receptor ligands. Further, the hematopoietic progenitor cells replicate their DNA while they are attached to the stromal cell layer and become foci of sustained cell proliferation. Thus, pro-TGF-α and the EGF receptor can function as mediators of intercellular adhesion and this interaction may promote a mitogenic response. They propose the term juxtacrine to designate this form of stimulation between adjacent cells

  20. Expression of transcription factor Pokemon in non-small cell lung cancer and its clinical significance.

    Science.gov (United States)

    Zhao, Zhi-hong; Wang, Sheng-fa; Yu, Liang; Wang, Ju; Chang, Hao; Yan, Wei-li; Fu, Kai; Zhang, Jian

    2008-03-05

    Transcription factor Pokemon, a central regulation gene of the important tumor suppressor ARF gene, exerted its activity by acting upstream of many tumor-suppressing genes and proto-oncogenes. Its expression in non-small cell lung cancer (NSCLC) and its clinical significance remains unclear. The aim of this study was to investigate the expression of Pokemon in NSCLC and to explore its correlation with the clinical pathological characteristics and its influence on patients' prognosis. Fifty-five cases of NSCLC were involved in this study. The expression of Pokemon in the tumor tissue, the corresponding tumor adjacent tissue and the surrounding tissue was detected via reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting, with the aim of investigating the correlation between the expression of Pokemon in tumor tissue of NSCLC and its clinical pathological characteristics. Moreover, a prognostic analysis was carried out based upon the immunohistochemical (IHC) detection of the expression of Pokemon gene in archival tumor specimens (5 years ago) of 62 cases of NSCLC. Statistical significance of the expression of Pokemon mRNA and protein was determined in the tumor tissue, the tumor adjacent tissue and the surrounding tissue (PPokemon was determined not to be associated with the patients' sex, age, smoking condition, tumor differentiation degree, histology and lymph node metastasis condition. However, its relationship with TNM staging was established (PPokemon expression was significantly higher than that of those with positive Pokemon expression (P=0.004), therefore, the expression of Pokemon is believed to be an independent factor affecting prognosis (P=0.034). Pokemon was over-expressed in NSCLC tissue and the expression of Pokemon might be of clinical significance in non-small cell lung cancer prognostic evaluation.

  1. Radiotherapy and receptor of epidermal growth factor; Radiotherapie et recepteur de l'Epidermal Growth Factor

    Energy Technology Data Exchange (ETDEWEB)

    Deberne, M. [Institut Gustave-Roussy, 94 - Villejuif (France)

    2009-10-15

    The expression level of the receptor of the epidermal growth factor is in correlation with the tumor cells radiosensitivity. An overexpression of the E.G.F.R. is often present in the bronchi cancer, epidermoid carcinomas of the O.R.L. sphere, esophagus, uterine cervix, and anal duct but also in the rectum cancers and glioblastomas. At the clinical level, the E.G.F.R. expression is in correlation with an unfavourable prognosis after radiotherapy in numerous tumoral localizations. In the rectum cancers it is an independent prognosis factor found in multifactorial analysis: increase of the rate of nodes and local recurrence when the E.G.F.R. is over expressed. In the uterine cervix cancers, the survival is is negatively affected in multifactorial analysis by the E.G.F.R. membranes expression level. At the therapy level, the development of anti E.G.F.R. targeted therapies (tyrosine kinase inhibitors and monoclonal antibodies) opens a new therapy field at radio-sensitivity potentiality. The irradiation makes an activation of the E.G.F.R. way that would be partially responsible of the post irradiation tumoral repopulation. This activation leads the phosphorylation of the PI3 kinase ways and M.A.P. kinase ones, then the Akt protein one that acts an apoptotic modulator part. It has been shown that blocking the E.G.F.R. way acts on three levels: accumulation of ells in phase G1, reduction of the cell repair and increasing of apoptosis. he inhibition of post irradiation action of the E.G.F.R. signal way is a factor explaining the ionizing radiation - anti E.G.F.R. synergy. The preclinical data suggest that the E.G.F.R. blocking by the monoclonal antibodies is more important than the use of tyrosine kinase inhibitors. A first positive randomized study with the cetuximab, published in 2006 in the epidermoid carcinomas of the O.R.L. sphere lead to its authorization on the market with the radiotherapy for this localization. The use of cetuximab in other indication with or in

  2. Intraoperative fluorescence delineation of head and neck cancer with a fluorescent Anti-epidermal growth factor receptor nanobody

    NARCIS (Netherlands)

    Van Driel, P.B.A.A.; Van Der Vorst, J.R.; Verbeek, F.P.R.; Oliveira, S.|info:eu-repo/dai/nl/304841455; Snoeks, T.J.A.; Keereweer, S.; Chan, B.; Boonstra, M.C.; Frangioni, J.V.; Van Bergen En Henegouwen, P.M.P.|info:eu-repo/dai/nl/071919481; Vahrmeijer, A.L.; Lowik, C.W.G.M.

    2014-01-01

    Intraoperative near-infrared (NIR) fluorescence imaging is a technology with high potential to provide the surgeon with real-time visualization of tumors during surgery. Our study explores the feasibility for clinical translation of an epidermal growth factor receptor (EGFR)-targeting nanobody for

  3. Resveratrol prevents angiotensin II-induced hypertrophy of vascular smooth muscle cells through the transactivation of growth factor receptors.

    Science.gov (United States)

    Hossain, Ekhtear; Anand-Srivastava, Madhu B

    2017-08-01

    We previously showed that augmented levels of endogenous angiotensin II (AngII) contribute to vascular smooth muscle cell (VSMC) hypertrophy through the transactivation of growth factor receptors in spontaneously hypertensive rats. Resveratrol (RV), a polyphenolic component of red wine, has also been shown to attenuate AngII-evoked VSMC hypertrophy; however, the molecular mechanism mediating this response is obscure. The present study was therefore undertaken to examine whether RV could prevent AngII-induced VSMC hypertrophy through the transactivation of growth factor receptor and associated signaling pathways. AngII treatment of VSMC enhanced the protein synthesis that was attenuated towards control levels by RV pretreatment as well as by the inhibitors of NADPH oxidase, c-Src, and growth factor receptors. Furthermore, RV pretreatment also inhibited enhanced levels of superoxide anion, NADPH oxidase activity, increased expression of NADPH oxidase subunits, and phosphorylation of c-Src, EGF-R, PDGE-R, ERK1/2, and AKT1/2. In conclusion, these results indicate that RV attenuates AngII-induced VSMC hypertrophy through the inhibition of enhanced oxidative stress and activation of c-Src, growth factor receptors, and MAPK/AKT signaling. We suggest that RV could be used as a therapeutic agent in the treatment of vascular complications associated with hypertension and hypertrophy.

  4. Radiolabeled cetuximab: dose optimization for epidermal growth factor receptor imaging in a head-and-neck squamous cell carcinoma model

    NARCIS (Netherlands)

    Hoeben, B.A.W.; Molkenboer-Kuenen, J.D.M.; Oyen, W.J.G.; Peeters, W.J.M.; Kaanders, J.H.A.M.; Bussink, J.; Boerman, O.C.

    2011-01-01

    Noninvasive imaging of the epidermal growth factor receptor (EGFR) in head-and-neck squamous cell carcinoma could be of value to select patients for EGFR-targeted therapy. We assessed dose optimization of (111) Indium-DTPA-cetuximab ((111) In-cetuximab) for EGFR imaging in a head-and-neck squamous

  5. Limited human epidermal growth factor receptor 2 discordance in metastatic breast cancer patients treated with trastuzumab, a population based study

    NARCIS (Netherlands)

    van Rooijen, J.M.; de Munck, L.; de Graaf, J.C.; Siesling, Sabine; de Vries, Erik G.; Boers, J.E.

    2014-01-01

    Background Accurate assessment of the human epidermal growth factor receptor 2 (HER2) in breast cancer is essential for proper treatment decisions. HER2 positivity confirmation rates in breast cancer trials by central testing pathology laboratories were reported to be approximately 85%. The aim of

  6. Molecular cloning and functional characterization of the human platelet-derived growth factor alpha receptor gene promoter

    NARCIS (Netherlands)

    Afink, G. B.; Nistér, M.; Stassen, B. H.; Joosten, P. H.; Rademakers, P. J.; Bongcam-Rudloff, E.; van Zoelen, E. J.; Mosselman, S.

    1995-01-01

    Expression of the platelet-derived growth factor alpha receptor (PDGF alpha R) is strictly regulated during mammalian development and tumorigenesis. The molecular mechanisms involved in the specific regulation of PDGF alpha R expression are unknown, but transcriptional regulation of the PDGF alpha R

  7. Positive fibroblast growth factor receptor 3 immunoreactivity is associated with low-grade non-invasive urothelial bladder cancer

    NARCIS (Netherlands)

    C. Poyet (Cédric); T. Hermanns (Thomas); Q. Zhong (Qing); E. Drescher (Eva); D. Eberli (Daniel); M. Burger (Maximilian); F. Hofstaedter (Ferdinand); A. Hartmann (Arndt); R. Stöhr (Robert); E.C. Zwarthoff (Ellen); T. Sulser (Tullio); P.J. Wild (Peter J.)

    2015-01-01

    textabstractIn addition to conventional clinicopathological parameters, molecular markers are also required in order to predict the course of disease in patients with urothelial bladder cancer (BC). Little is known about fibroblast growth factor receptor 3 (FGFR3) immunoreactivity and the clinical

  8. Limited human epidermal growth factor receptor 2 discordance in metastatic breast cancer patients treated with trastuzumab, a population based study

    NARCIS (Netherlands)

    van Rooijen, J. M.; de Munck, L.; de Graaf, J. C.; Siesling, S.; de Vries, E. G.; Boers, J. E.

    Background: Accurate assessment of the human epidermal growth factor receptor 2 (HER2) in breast cancer is essential for proper treatment decisions. HER2 positivity confirmation rates in breast cancer trials by central testing pathology laboratories were reported to be approximately 85%. The aim of

  9. Primary cilia and coordination of receptor tyrosine kinase (RTK) and transforming growth factor β (TGF-β) signaling

    DEFF Research Database (Denmark)

    Christensen, Søren Tvorup; Morthorst, Stine Kjær; Mogensen, Johanne Bay

    2017-01-01

    are at the root of a pleiotropic group of diseases and syndromic disorders called ciliopathies. In this review, we present an overview of primary cilia-mediated regulation of receptor tyrosine kinase (RTK) and transforming growth factor β (TGF-β) signaling. Further, we discuss how defects in the coordination...

  10. A nomogram for predicting pathological complete response in patients with human epidermal growth factor receptor 2 negative breast cancer

    International Nuclear Information System (INIS)

    Jin, Xi; Jiang, Yi-Zhou; Chen, Sheng; Yu, Ke-Da; Ma, Ding; Sun, Wei; Shao, Zhi-Min; Di, Gen-Hong

    2016-01-01

    The response to neoadjuvant chemotherapy has been proven to predict long-term clinical benefits for patients. Our research is to construct a nomogram to predict pathological complete response of human epidermal growth factor receptor 2 negative breast cancer patients. We enrolled 815 patients who received neoadjuvant chemotherapy from 2003 to 2015 and divided them into a training set and a validation set. Univariate logistic regression was performed to screen for predictors and construct the nomogram; multivariate logistic regression was performed to identify independent predictors. After performing the univariate logistic regression analysis in the training set, tumor size, hormone receptor status, regimens of neoadjuvant chemotherapy and cycles of neoadjuvant chemotherapy were the final predictors for the construction of the nomogram. The multivariate logistic regression analysis demonstrated that T4 status, hormone receptor status and receiving regimen of paclitaxel and carboplatin were independent predictors of pathological complete response. The area under the receiver operating characteristic curve of the training set and the validation set was 0.779 and 0.701, respectively. We constructed and validated a nomogram to predict pathological complete response in human epidermal growth factor receptor 2 negative breast cancer patients. We also identified tumor size, hormone receptor status and paclitaxel and carboplatin regimen as independent predictors of pathological complete response. The online version of this article (doi:10.1186/s12885-016-2652-z) contains supplementary material, which is available to authorized users

  11. Cloning of Human Tumor Necrosis Factor (TNF) Receptor cDNA and Expression of Recombinant Soluble TNF-Binding Protein

    Science.gov (United States)

    Gray, Patrick W.; Barrett, Kathy; Chantry, David; Turner, Martin; Feldmann, Marc

    1990-10-01

    The cDNA for one of the receptors for human tumor necrosis factor (TNF) has been isolated. This cDNA encodes a protein of 455 amino acids that is divided into an extracellular domain of 171 residues and a cytoplasmic domain of 221 residues. The extracellular domain has been engineered for expression in mammalian cells, and this recombinant derivative binds TNFα with high affinity and inhibits its cytotoxic activity in vitro. The TNF receptor exhibits similarity with a family of cell surface proteins that includes the nerve growth factor receptor, the human B-cell surface antigen CD40, and the rat T-cell surface antigen OX40. The TNF receptor contains four cysteine-rich subdomains in the extra-cellular portion. Mammalian cells transfected with the entire TNF receptor cDNA bind radiolabeled TNFα with an affinity of 2.5 x 10-9 M. This binding can be competitively inhibited with unlabeled TNFα or lymphotoxin (TNFβ).

  12. Decreased numbers of chemotactic factor receptors in chronic neutropenia with defective chemotaxis: spontaneous recovery from the neutrophil abnormalities during early childhood

    International Nuclear Information System (INIS)

    Yasui, K.; Yamazaki, M.; Miyagawa, Y.; Komiyama, A.; Akabane, T.

    1987-01-01

    Childhood chronic neutropenia with decreased numbers of chemotactic factor receptors as well as defective chemotaxis was first demonstrated in an 8-month-old girl. Chemotactic factor receptors on neutrophils were assayed using tritiated N-formyl-methionyl-leucyl-phenylalanine ( 3 H-FMLP). The patient's neutrophils had decreased numbers of the receptors: numbers of the receptors were 20,000 (less than 3 SD) as compared with those of control cells of 52,000 +/- 6000 (mean +/- SD) (n = 10). The neutropenia disappeared spontaneously by 28 months of age parallel with the improvement of chemotaxis and increase in numbers of chemotactic factor receptors. These results demonstrate a transient decrease of neutrophil chemotactic factor receptors as one of the pathophysiological bases of a transient defect of neutrophil chemotaxis in this disorder

  13. Experimental diabetes increases insulin-like growth factor I and II receptor concentration and gene expression in kidney

    International Nuclear Information System (INIS)

    Werner, H.; Shen-Orr, Z.; Stannard, B.; Burguera, B.; Roberts, C.T. Jr.; LeRoith, D.

    1990-01-01

    Insulinlike growth factor I (IGF-I) is a mitogenic hormone with important regulatory roles in growth and development. One of the target organs for IGF-I action is the kidney, which synthesizes abundant IGF-I receptors and IGF-I itself. To study the involvement of IGF-I and the IGF-I receptor in the development of nephropathy, one of the major complications of diabetes mellitus, we measured the expression of these genes in the kidney and in other tissues of the streptozocin-induced diabetic rat. The binding of 125I-labeled IGF-I to crude membranes was measured in the same tissues. We observed a 2.5-fold increase in the steady-state level of IGF-I-receptor mRNA in the diabetic kidney, which was accompanied by a 2.3-fold increase in IGF-I binding. In addition to this increase in IGF-I binding to the IGF-I receptor, there was also binding to a lower-molecular-weight material that may represent an IGF-binding protein. No change was detected in the level of IGF-I-peptide mRNA. Similarly, IGF-II-receptor mRNA levels and IGF-II binding were significantly increased in the diabetic kidney. IGF-I- and IGF-II-receptor mRNA levels and IGF-I and IGF-II binding returned to control values after insulin treatment. Because the IGF-I receptor is able to transduce mitogenic signals on activation of its tyrosine kinase domain, we hypothesize that, among other factors, high levels of receptor in the diabetic kidney may also be involved in the development of diabetic nephropathy. Increased IGF-II-receptor expression in the diabetic kidney may be important for the intracellular transport and packaging of lysosomal enzymes, although a role for this receptor in signal transduction cannot be excluded. Finally, the possible role of IGF-binding proteins requires further study

  14. Reproductive factors and risk of hormone receptor positive and negative breast cancer: a cohort study

    International Nuclear Information System (INIS)

    Ritte, Rebecca; Grote, Verena; Boeing, Heiner; Aleksandrova, Krasimira; Trichopoulou, Antonia; Lagiou, Pagona; Trichopoulos, Dimitrios; Palli, Domenico; Berrino, Franco; Mattiello, Amalia; Tumino, Rosario; Tikk, Kaja; Sacerdote, Carlotta; Quirós, José Ramón; Buckland, Genevieve; Molina-Montes, Esther; Chirlaque, María-Dolores; Ardanaz, Eva; Amiano, Pilar; Bueno-de-Mesquita, H Bas; Gils, Carla H van; Peeters, Petra HM; Lukanova, Annekatrin; Wareham, Nick; Khaw, Kay-Tee; Key, Timothy J; Travis, Ruth C; Weiderpass, Elisabete; Dumeaux, Vanessa; Lund, Eliv; Sund, Malin; Andersson, Anne; Romieu, Isabelle; Tjønneland, Anne; Rinaldi, Sabina; Vineis, Paulo; Merritt, Melissa A; Riboli, Elio; Kaaks, Rudolf; Olsen, Anja; Overvad, Kim; Dossus, Laure; Fournier, Agnès; Clavel-Chapelon, Françoise

    2013-01-01

    The association of reproductive factors with hormone receptor (HR)-negative breast tumors remains uncertain. Within the EPIC cohort, Cox proportional hazards models were used to describe the relationships of reproductive factors (menarcheal age, time between menarche and first pregnancy, parity, number of children, age at first and last pregnancies, time since last full-term childbirth, breastfeeding, age at menopause, ever having an abortion and use of oral contraceptives [OC]) with risk of ER-PR- (n = 998) and ER+PR+ (n = 3,567) breast tumors. A later first full-term childbirth was associated with increased risk of ER+PR+ tumors but not with risk of ER-PR- tumors (≥35 vs. ≤19 years HR: 1.47 [95% CI 1.15-1.88] p trend < 0.001 for ER+PR+ tumors; ≥35 vs. ≤19 years HR: 0.93 [95% CI 0.53-1.65] p trend = 0.96 for ER-PR- tumors; P het = 0.03). The risk associations of menarcheal age, and time period between menarche and first full-term childbirth with ER-PR-tumors were in the similar direction with risk of ER+PR+ tumors (p het = 0.50), although weaker in magnitude and statistically only borderline significant. Other parity related factors such as ever a full-term birth, number of births, age- and time since last birth were associated only with ER+PR+ malignancies, however no statistical heterogeneity between breast cancer subtypes was observed. Breastfeeding and OC use were generally not associated with breast cancer subtype risk. Our study provides possible evidence that age at menarche, and time between menarche and first full-term childbirth may be associated with the etiology of both HR-negative and HR-positive malignancies, although the associations with HR-negative breast cancer were only borderline significant

  15. Human Epidermal Growth Factor Receptor 2 Overexpression in Micropapillary and Other Variants of Urothelial Carcinoma.

    Science.gov (United States)

    Behzatoğlu, Kemal; Yörükoğlu, Kutsal; Demir, Hale; Bal, Nebil

    2016-06-21

    Human epidermal growth factor receptor 2 (HER2) protein overexpression or gene amplification has been shown in urothelial bladder cancer. This could be helpful when using targeted anti-HER2 therapy on these tumors. To evaluate HER2 immunohistochemical expression in conventional urothelial carcinoma (UC), in situ UC, and UC variants primarily in micropapillary urothelial carcinoma (MPUC). The study evaluated 60 MPUC cases; 25 invasive, 20 low-grade noninvasive, and 10 high-grade noninvasive UC cases; 8 in situ UC cases; and 69 UC variant cases. The immunohistochemistry staining was scored according to recommendations of the American Society of Clinical Oncology/College of American Pathologists 2013 HER2 test guideline established for breast cancer and only 3+ staining was considered HER2 overexpression. HER2 overexpression was determined by 3+ staining. 34 of 60 MPUC cases (56%) showed HER2 overexpression (3+ staining). We observed 3+ staining HER2 overexpression in nine of 25 conventional invasive UC cases (36%), four of eight in situ UC cases (50%), and three of six lipid cell variant cases (50%). 3+ staining HER2 overexpression was not seen in eight glandular, six small cell, and five sarcomatoid variant cases. HER2 overexpression was negative in the 20 low-grade noninvasive UC cases but positive in two of the 10 high-grade noninvasive UC cases (20%). We observed HER2 overexpression most commonly in MPUC cases. We also found HER2 overexpression in conventional invasive and in situ UC cases. Pure in situ UC and conventional invasive UC, especially MPUC, could be candidate tumors for treatment with anti-HER2 antibody (trastuzumab therapy). Targeted therapy has a limited place in treatment of bladder cancer. In this study, human epidermal growth factor receptor 2 (HER2) overexpression in bladder carcinomas was evaluated in a large number of cases. Anti-HER2 therapy could be used in bladder cancers, as in breast and gastric cancers. Copyright © 2016 European

  16. DNA repair in the c-myc proto-oncogene locus: Possible involvement in susceptibility or resistance to plasmacytoma induction in BALB/c mice

    International Nuclear Information System (INIS)

    Beecham, E.J.; Mushinski, J.F.; Shacter, E.; Potter, M.; Bohr, V.A.

    1991-01-01

    This report describes an unexpected difference in the efficiency of removal of UV-induced DNA damage in the c-myc locus in splenic B lymphoblasts from two inbred strains of mice. In cells from plasmacytoma-resistant DBA/2N mice, 35% of UV-induced damage in the regulatory and 5' flank of c-myc is removed by 12 h. However, in cells from plasmacytoma-susceptible BALB/cAn mice, damage is not removed from this region. In the protein-encoding region and 3' flank of c-myc as well as in two dihydrofolate reductase gene fragments, UV damage is repaired with similar efficiency in B lymphoblasts from both strains of mice. Furthermore, in the protein-encoding portion and 3' flank of c-myc, damage is selectively removed from only the transcribed strand. No repair is detected in the nontranscribed strand. In contrast, DNA repair in the 5' flank of c-myc is not strand specific; in DNA from DBA/2N cells, UV damage is rapidly removed from both the transcribed and nontranscribed strands. In BALB/cAn cells no repair was detected in either strand in the 5'flank, consistent with the results with double-stranded, nick-translated probes to this region of c-myc. In addition to the repair studies, we have detected post-UV-damage formation: in most of the genes studied, we find that additional T4 endonuclease-sensitive sites are formed in the DNA 2 h after irradiation. Our findings provide new insights into the details of gene-specific and strand-specific DNA repair and suggest that there may be close links between DNA repair and B-cell neoplastic development

  17. Investigating the Role of Cooperative Interactions Between the neu Proto-oncogene and the Other erbB Family Members in Rat Mammary Carcinogenesis

    National Research Council Canada - National Science Library

    Gould, Michael

    1998-01-01

    .... To date, all three lines show a low incidence of spontaneous mammary tumorigenesis. The vast majority of tumors that have arisen in the oldest line appear after one year of age and are fibroadenomas...

  18. Non-covalent interactions of the carcinogen (+)-anti-BPDE with exon 1 of the human K-ras proto-oncogene

    Science.gov (United States)

    Rodriguez, Jorge H.; Deligkaris, Christos

    2013-03-01

    Investigating the complementary, but different, effects of physical (non-covalent) and chemical (covalent) mutagen-DNA and carcinogen-DNA interactions is important for understanding possible mechanisms of development and prevention of mutagenesis and carcinogenesis. A highly mutagenic and carcinogenic metabolite of the polycyclic aromatic hydrocarbon benzo[ α]pyrene, namely (+)-anti-BPDE, is known to undergo both physical and chemical complexation with DNA. The major covalent adduct, a promutagenic, is known to be an external (+)-trans-anti-BPDE-N2-dGuanosine configuration whose origins are not fully understood. Thus, it is desirable to study the mechanisms of external non-covalent BPDE-DNA binding and their possible relationships to external covalent trans adduct formation. We present a detailed codon-by-codon computational study of the non-covalent interactions of (+)-anti-BPDE with DNA which explains and correctly predicts preferential (+)-anti-BPDE binding at minor groove guanosines. Due to its relevance to carcinogenesis, the interaction of (+)-anti-BPDE with exon 1 of the human K-ras gene has been studied in detail. Present address: Department of Physics, Drury University

  19. Significance of epidermal growth factor receptor signaling for acquisition of meiotic and developmental competence in mammalian oocytes

    Czech Academy of Sciences Publication Activity Database

    Procházka, Radek; Blaha, Milan; Němcová, Lucie

    2017-01-01

    Roč. 97, č. 4 (2017), s. 537-549 ISSN 0006-3363 R&D Projects: GA MZe(CZ) QJ1510138; GA MŠk EF15_003/0000460 Institutional support: RVO:67985904 Keywords : amphiregulin * cumulus cells * epidermal growth factor receptor Subject RIV: EB - Genetics ; Molecular Biology OBOR OECD: Reproductive biology (medical aspects to be 3) Impact factor: 3.432, year: 2016

  20. Enhancement of insulin-like growth factor 2 receptors in glioblastoma

    International Nuclear Information System (INIS)

    Sara, V.; Prisell, Per; Sjoegren, Barbro; Enberg, Goesta

    1986-01-01

    The somatomedins (IGF-1/IGF-2) are a family of growth-promoting hormones which have been identified in the human central nervous system where their specific receptors are distributed. The present study identified somatomedin receptors in glioblastoma and compared them with those found in normal brain. A significant enhancement in the binding of 125 1-IGF-2 but not 125 1-IGF-1 to glioblastoma membranes was found. A fourfold increase in IGF-2 receptor concentration was observed. These findings indicate enhanced expression of the IGF-2 receptor in glioblastoma. (author)

  1. Enhancement of insulin-like growth factor 2 receptors in glioblastoma

    Energy Technology Data Exchange (ETDEWEB)

    Sara, V; Prisell, P; Sjoegren, B; Persson, L; Boethius, J; Enberg, G

    1986-09-01

    The somatomedins (IGF-1/IGF-2) are a family of growth-promoting hormones which have been identified in the human central nervous system where their specific receptors are distributed. The present study identified somatomedin receptors in glioblastoma and compared them with those found in normal brain. A significant enhancement in the binding of /sup 125/1-IGF-2 but not /sup 125/1-IGF-1 to glioblastoma membranes was found. A fourfold increase in IGF-2 receptor concentration was observed. These findings indicate enhanced expression of the IGF-2 receptor in glioblastoma. 14 refs.

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

    Directory of Open Access Journals (Sweden)

    Takamitsu Sasaki

    2007-12-01

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

  3. Antibodies to a soluble form of a tumor necrosis factor (TNF) receptor have TNF-like activity

    DEFF Research Database (Denmark)

    Engelmann, H; Holtmann, H; Brakebusch, C

    1990-01-01

    Immunological cross-reactivity between tumor necrosis factor (TNF) binding proteins which are present in human urine (designated TBPI and TBPII) and two molecular species of the cell surface receptors for TNF is demonstrated. The two TNF receptors are shown to be immunologically distinct, to differ....... These antibodies are cytotoxic to cells which are sensitive to TNF toxicity, induce resistance to TNF toxicity, enhance the incorporation of thymidine into normal fibroblasts, inhibit the growth of chlamydiae, and induce the synthesis of prostaglandin E2. Monovalent F(ab) fragments of the polyclonal antibodies...

  4. Overexpression of Insulin-like Growth Factor-1 Receptor Is Associated With Penile Cancer Progression.

    Science.gov (United States)

    Ball, Mark W; Bezerra, Stephania M; Chaux, Alcides; Faraj, Sheila F; Gonzalez-Roibon, Nilda; Munari, Enrico; Sharma, Rajni; Bivalacqua, Trinity J; Netto, George J; Burnett, Arthur L

    2016-06-01

    To evaluate insulin-like growth factor-1 receptor (IGF1R) expression in penile cancer and its association with oncologic outcomes. Tissue microarrays were constructed from 53 patients treated at our institution. Expression of IGF1R was evaluated using a Her2-like scoring system. Overexpression was defined as 1+ or greater membranous staining. Association of IGF1R expression with pathologic features was assessed with comparative statistics, and association with local recurrence, progression to nodal or distance metastases, or death was assessed with Kaplan-Meier survival analysis and Cox proportional hazard regression models. Overall, IGF1R overexpression was seen in 33 (62%) cases. With a median follow-up of 27.8 months, IGF1R overexpression was associated with inferior progression-free survival (PFS) (P  =  .003). In a multivariable model controlling for grade, T stage, perineural invasion, and lymphovascular invasion, IGF1R expression was independently associated with disease progression (hazard ratio 2.3, 95% confidence interval 1.1-5.1, P  =  .03. Comparing patients without IGF1R overexpression to those with overexpression, 5-year PFS was 94.1% vs 45.8%. IGF1R overexpression was associated with inferior PFS in penile cancer. Drugs that target IGF1R and downstream messengers may have a therapeutic benefit in patients that exhibit IGF1R overexpression. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. Critical role of tumor necrosis factor receptor 1 in the pathogenesis of pulmonary emphysema in mice.

    Science.gov (United States)

    Fujita, Masaki; Ouchi, Hiroshi; Ikegame, Satoshi; Harada, Eiji; Matsumoto, Takemasa; Uchino, Junji; Nakanishi, Yoichi; Watanabe, Kentaro

    2016-01-01

    COPD is a major cause of chronic morbidity and mortality throughout the world. Although tumor necrosis factor-α (TNF-α) has a critical role in the development of COPD, the role of different TNF receptors (TNFRs) in pulmonary emphysema has not been resolved. We aimed to clarify the role of TNFRs in the development of pulmonary emphysema. TNF-α transgenic mice, a murine model of COPD in which the mice spontaneously develop emphysema with a large increase in lung volume and pulmonary hypertension, were crossed with either TNFR1-deficient mice or TNFR2-deficient mice. After 6 months, the gross appearance of the lung, lung histology, and pulmonary and cardiac physiology were determined. In addition, the relationship between apoptosis and emphysema was investigated. Pulmonary emphysema-like changes disappeared with deletion of TNFR1. However, slight improvements were attained with deletion of TNFR2. Apoptotic cells in the interstitium of the lung were observed in TNF-α transgenic mice. The apoptotic signals through TNFR1 appear critical for the pathogenesis of pulmonary emphysema. In contrast, the inflammatory process has a less important role for the development of emphysema.

  6. Dialkoxyquinazolines: Screening Epidermal Growth Factor ReceptorTyrosine Kinase Inhibitors for Potential Tumor Imaging Probes

    Energy Technology Data Exchange (ETDEWEB)

    VanBrocklin, Henry F.; Lim, John K.; Coffing, Stephanie L.; Hom,Darren L.; Negash, Kitaw; Ono, Michele Y.; Hanrahan, Stephen M.; Taylor,Scott E.; Vanderpoel, Jennifer L.; Slavik, Sarah M.; Morris, Andrew B.; Riese II, David J.

    2005-09-01

    The epidermal growth factor receptor (EGFR), a long-standingdrug development target, is also a desirable target for imaging. Sixteendialkoxyquinazoline analogs, suitable for labeling with positron-emittingisotopes, have been synthesized and evaluated in a battery of in vitroassays to ascertain their chemical and biological properties. Thesecharacteristics provided the basis for the adoption of a selection schemato identify lead molecules for labeling and in vivo evaluation. A newEGFR tyrosine kinase radiometric binding assay revealed that all of thecompounds possessed suitable affinity (IC50 = 0.4 - 51 nM) for the EGFRtyrosine kinase. All of the analogs inhibited ligand-induced EGFRtyrosine phosphorylation (IC50 = 0.8 - 20 nM). The HPLC-estimatedoctanol/water partition coefficients ranged from 2.0-5.5. Four compounds,4-(2'-fluoroanilino)- and 4-(3'-fluoroanilino)-6,7-diethoxyquinazoline aswell as 4-(3'-chloroanilino)- and4-(3'-bromoanilino)-6,7-dimethoxyquinazoline, possess the bestcombination of characteristics that warrant radioisotope labeling andfurther evaluation in tumor-bearing mice.

  7. Leukemia inhibitory factor promote trophoblast invasion via urokinase-type plasminogen activator receptor in preeclampsia.

    Science.gov (United States)

    Zheng, Qin; Dai, Kuixing; Cui, Xinyuan; Yu, Ming; Yang, Xuesong; Yan, Bin; Liu, Shuai; Yan, Qiu

    2016-05-01

    Preeclampsia is a pregnancy-related syndrome which can cause perinatal mortality and morbidity. Inadequate invasion by trophoblast cells may lead to poor perfusion of the placenta, even result in preeclampsia. Understanding the molecular mechanisms underlying placentation facilitates the better intervention of preeclampsia. Urokinase-type plasminogen activator receptor (uPAR) is involved in the physiological and pathological processes. Leukemia inhibitory factor (LIF) is an important regulator in the establishment of pregnancy. However, the expression of uPAR in preeclamptic patients and its relationship with LIF remains unclear. In the current study, we found that the level of uPAR was relatively lower in the placentas from preeclamptic patients as compared with normal pregnant women. LIF promoted trophoblast cell outgrowth by upregulating uPAR in an explants culture, and LIF also enhanced migration and invasion potential through uPAR in trophoblast JAR and JEG-3 cell lines, and with increased gelatinolytic activities of matrix metalloproteinase 2 (MMP-2). The effect of LIF and uPAR on trophoblast migration and invasion was mediated by PI3K/AKT signaling pathway. Our data indicates the roles of LIF in promoting trophoblast migration and invasion through uPAR and suggest that abnormal expression of uPAR might be associated with the etiology of preeclampsia. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  8. Receptor activator of nuclear factor kappa B (RANK as a determinant of peri-implantitis

    Directory of Open Access Journals (Sweden)

    Rakić Mia

    2013-01-01

    Full Text Available Background/Aim. Peri-implantitis presents inflammatory process that affects soft and hard supporting tissues of osseointegrated implant based on inflammatory osteoclastogenesis. The aim of this study was to investigate whether receptor activator of nuclear factor kappa B (RANK concentrations in peri-implant crevicular fluid could be associated with clinical parameters that reflect inflammatory nature of peri-implantitis. Methods. The study included 67 patients, 22 with diagnosed peri-implantitis, 22 persons with healthy peri-implant tissues and 23 patients with periodontitis. Clinical parameters from each patient were recorded and samples of peri-implant/gingival crevicular fluid were collected for the enzyme-linked immunosorbent assay (ELISA analysis. Results. RANK concentration was significantly increased in samples from the patients with periimplantitis when compared to healthy implants (p < 0.0001, where the average levels were 9 times higher. At the same time RANK concentration was significantly higher in periimplantitis than in periodontitis sites (p < 0.0001. In implant patients pocket depths and bleeding on probing values were positively associated with high RANK concentrations (p < 0.0001. Conclusion. These results revealed association of increased RANK concentration in samples of periimplant/ gingival crevicular fluid with peri-implant inflammation and suggests that RANK could be a pathologic determinant of peri-implantitis, thereby a potential parameter in assessment of peri-implant tissue inflammation and a potential target in designing treatment strategies.

  9. Inhibitors of the epidermal growth factor receptor in apple juice extract.

    Science.gov (United States)

    Kern, Melanie; Tjaden, Zeina; Ngiewih, Yufanyi; Puppel, Nicole; Will, Frank; Dietrich, Helmut; Pahlke, Gudrun; Marko, Doris

    2005-04-01

    The polyphenol-rich extract of a consumer-relevant apple juice blend was found to potently inhibit the growth of the human colon cancer cell line HT29 in vitro. The epidermal growth factor receptor (EGFR) and its subsequent signaling cascade play an important role in the regulation of cell proliferation in HT29 cells. The protein tyrosine kinase activity of an EGFR preparation was effectively inhibited by the polyphenol-rich apple juice extract. Treatment of intact cells with this extract resulted in the suppression of the subsequent mitogen-activated protein kinase cascade. Amongst the so far identified apple juice constituents, the proanthocyanidins B1 and B2 as well as quercetin-3-glc (isoquercitrin) and quercetin-3-gal (hyperoside) were found to possess substantial EGFR-inhibitory properties. However, as to be expected from the final concentration of these potential EGFR inhibitors in the original polyphenol-rich extract, a synthetic mixture of the apple juice constituents identified and available so far, including both proanthocyanidins and the quercetin glycosides, showed only marginal inhibitory effects on the EGFR. These results permit the assumption that yet unknown constituents contribute substantially to the potent EGFR-inhibitory properties of polyphenol-rich apple juice extract. In summary, the polyphenol composition of apple juice possesses promising growth-inhibitory properties, affecting proliferation-associated signaling cascades in colon tumor cells.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  11. Expression of granulocyte colony-stimulating factor receptor correlates with prognosis in oral and mesopharyngeal carcinoma.

    Science.gov (United States)

    Tsuzuki, H; Fujieda, S; Sunaga, H; Noda, I; Saito, H

    1998-02-15

    Granulocyte colony-stimulating factor receptors (G-CSFRs) have been observed on the surface of not only hematopoietic cells but also several cancer cells. The stimulation of G-CSF has been demonstrated to induce proliferation and activation of G-CSFR-positive cells. In this study, we investigated the expression of G-CSFR on the surface of tumor cells and G-CSF production in oral and mesopharyngeal squamous cell carcinoma (SCC) by an immunohistochemical approach. Of 58 oral and mesopharyngeal SCCs, 31 cases (53.4%) and 36 cases (62.1%) were positive for G-CSFR and G-CSF, respectively. There was no association between G-CSFR expression and G-CSF staining. In the group positive for G-CSFR expression, relapse was significantly more likely after primary treatment (P = 0.0069), whereas there was no association between G-CSFR expression and age, sex, tumor size, lymph node metastasis, and clinical stage. Also, the G-CSFR-positive groups had a significantly lower disease-free and overall survival rate than the G-CSFR-negative groups (P = 0.0172 and 0.0188, respectively). However, none of the clinical markers correlated significantly with G-CSF staining, nor did the status of G-CSF production influence the overall survival. The results imply that assessment of G-CSFR may prove valuable in selecting patients with oral and mesopharyngeal SCC for aggressive therapy.

  12. Epidermal growth factor receptor expression in different subtypes of oral lichenoid disease.

    Science.gov (United States)

    Cortés-Ramírez, Dionisio-Alejandro; Rodríguez-Tojo, María-Jose; Coca-Meneses, Juan-Carlos; Marichalar-Mendia, Xabier; Aguirre-Urizar, José-Manuel

    2014-09-01

    The oral lichenoid disease (OLD) includes different chronic inflammatory processes such as oral lichen planus (OLP) and oral lichenoid lesions (OLL), both entities with controversial diagnosis and malignant potential. Epidermal growth factor receptor (EFGR) is an important oral carcinogenesis biomarker and overexpressed in several oral potentially malignant disorders. To analyze the EGFR expression in the OLD to find differences between OLP and OLL, and to correlate it with the main clinical and pathological features. Forty-four OLD cases were studied and classified according to their clinical (Group C1: only papular lesions / Group C2: papular and other lesions) and histopathological features (Group HT: OLP-typical / Group HC: OLP-compatible) based in previous published criteria. Standard immunohistochemical identification of EGFR protein was performed. Comparative and descriptive statistical analyses were performed. Thirty-five cases (79.5%) showed EGFR overexpression without significant differences between clinical and histopathological groups (p<0.05). Histological groups showed significant differences in the EGFR expression pattern (p=0.016). Conlusions: All OLD samples showed high EGFR expression. The type of clinical lesion was not related with EGFR expression; however, there are differences in the EGFR expression pattern between histological groups that may be related with a different biological profile and malignant risk.

  13. Involvement of Fibroblast Growth Factor Receptor Genes in Benign Prostate Hyperplasia in a Korean Population

    Directory of Open Access Journals (Sweden)

    Hae Jeong Park

    2013-01-01

    Full Text Available Fibroblast growth factors (FGFs and their receptors (FGFRs have been implicated in prostate growth and are overexpressed in benign prostatic hyperplasia (BPH. In this study, we investigated whether single nucleotide polymorphisms (SNPs of the FGFR genes (FGFR1 and FGFR2 were associated with BPH and its clinical phenotypes in a population of Korean men. We genotyped four SNPs in the exons of FGFR1 and FGFR2 (rs13317 in FGFR1; rs755793, rs1047100, and rs3135831 in FGFR2 using direct sequencing in 218 BPH patients and 213 control subjects. No SNPs of FGFR1 or FGFR2 genes were associated with BPH. However, analysis according to clinical phenotypes showed that rs1047100 of FGFR2 was associated with prostate volume in BPH in the dominant model (GA/AA versus GG, P = 0.010. In addition, a significant association was observed between rs13317 of FGFR1 and international prostate symptom score (IPSS in the additive (TC versus CC versus TT, P = 0.0022 and dominant models (TC/CC versus TT, P = 0.005. Allele frequency analysis also showed significant association between rs13317 and IPSS (P = 0.005. These results suggested that FGFR genes could be related to progression of BPH.

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

    International Nuclear Information System (INIS)

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

    2014-01-01

    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

  15. Systemic Hypoxia Changes the Organ-Specific Distribution of Vascular Endothelial Growth Factor and Its Receptors

    Science.gov (United States)

    Marti, Hugo H.; Risau, Werner

    1998-12-01

    Vascular endothelial growth factor (VEGF) plays a key role in physiological blood vessel formation and pathological angiogenesis such as tumor growth and ischemic diseases. Hypoxia is a potent inducer of VEGF in vitro. Here we demonstrate that VEGF is induced in vivo by exposing mice to systemic hypoxia. VEGF induction was highest in brain, but also occurred in kidney, testis, lung, heart, and liver. In situ hybridization analysis revealed that a distinct subset of cells within a given organ, such as glial cells and neurons in brain, tubular cells in kidney, and Sertoli cells in testis, responded to the hypoxic stimulus with an increase in VEGF expression. Surprisingly, however, other cells at sites of constitutive VEGF expression in normal adult tissues, such as epithelial cells in the choroid plexus and kidney glomeruli, decreased VEGF expression in response to the hypoxic stimulus. Furthermore, in addition to VEGF itself, expression of VEGF receptor-1 (VEGFR-1), but not VEGFR-2, was induced by hypoxia in endothelial cells of lung, heart, brain, kidney, and liver. VEGF itself was never found to be up-regulated in endothelial cells under hypoxic conditions, consistent with its paracrine action during normoxia. Our results show that the response to hypoxia in vivo is differentially regulated at the level of specific cell types or layers in certain organs. In these tissues, up- or down-regulation of VEGF and VEGFR-1 during hypoxia may influence their oxygenation after angiogenesis or modulate vascular permeability.

  16. Selection of DNA aptamers against epidermal growth factor receptor with high affinity and specificity.

    Science.gov (United States)

    Wang, Deng-Liang; Song, Yan-Ling; Zhu, Zhi; Li, Xi-Lan; Zou, Yuan; Yang, Hai-Tao; Wang, Jiang-Jie; Yao, Pei-Sen; Pan, Ru-Jun; Yang, Chaoyong James; Kang, De-Zhi

    2014-10-31

    Epidermal growth factor receptor (EGFR/HER1/c-ErbB1), is overexpressed in many solid cancers, such as epidermoid carcinomas, malignant gliomas, etc. EGFR plays roles in proliferation, invasion, angiogenesis and metastasis of malignant cancer cells and is the ideal antigen for clinical applications in cancer detection, imaging and therapy. Aptamers, the output of the systematic evolution of ligands by exponential enrichment (SELEX), are DNA/RNA oligonucleotides which can bind protein and other substances with specificity. RNA aptamers are undesirable due to their instability and high cost of production. Conversely, DNA aptamers have aroused researcher's attention because they are easily synthesized, stable, selective, have high binding affinity and are cost-effective to produce. In this study, we have successfully identified DNA aptamers with high binding affinity and selectivity to EGFR. The aptamer named TuTu22 with Kd 56±7.3nM was chosen from the identified DNA aptamers for further study. Flow cytometry analysis results indicated that the TuTu22 aptamer was able to specifically recognize a variety of cancer cells expressing EGFR but did not bind to the EGFR-negative cells. With all of the aforementioned advantages, the DNA aptamers reported here against cancer biomarker EGFR will facilitate the development of novel targeted cancer detection, imaging and therapy. Copyright © 2014 Elsevier Inc. All rights reserved.

  17. Optimization of 1H-indazol-3-amine derivatives as potent fibroblast growth factor receptor inhibitors.

    Science.gov (United States)

    Cui, Jing; Peng, Xia; Gao, Dingding; Dai, Yang; Ai, Jing; Li, Yingxia

    2017-08-15

    Fibroblast growth factor receptor (FGFR) is a potential target for cancer therapy because of its critical role in promoting cancer formation and progression. In a continuing effort to improve the cellular activity of hit compound 7r bearing an indazole scaffold, which was previously discovered by our group, several compounds harnessing fluorine substituents were designed, synthesized and biological evaluated. Besides, the region extended out to the ATP binding pocket toward solvent was also explored. Among them, compound 2a containing 2,6-difluoro-3-methoxyphenyl residue exhibited the most potent activities (FGFR1: less than 4.1nM, FGFR2: 2.0±0.8nM). More importantly, compound 2a showed an improved antiproliferative effect against KG1 cell lines and SNU16 cell lines with IC 50 values of 25.3±4.6nM and 77.4±6.2nM respectively. Copyright © 2017. Published by Elsevier Ltd.

  18. Catalase reverses tumorigenicity in a malignant cell line by an epidermal growth factor receptor pathway.

    Science.gov (United States)

    Finch, Joanne S; Tome, Margaret E; Kwei, Kevin A; Bowden, G Tim

    2006-03-01

    We have used a keratinocyte in vivo/in vitro cell model to test the hypothesis that hydrogen peroxide acts as a signaling molecule, contributing to proliferation and tumorigenesis. A cell line, 6M90, that produces squamous cell carcinoma (SCC), has high levels of ROS and low levels of catalase. A new cell line, MTOC2, generated from parental 6M90 cells by introduction of a Tet-responsive catalase transgene, effectively expressed higher peroxisomal catalase. Increased catalase expression diminished constitutive ROS and enhanced viability after treatment with hydrogen peroxide. Protein tyrosine phosphatase activity was higher in the MTOC2 cells with high catalase, consistent with detection of a lower level of phosphorylation at tyrosine 1068 of the epidermal growth factor receptor (EGF-R). Transcription of downstream c-fos, AP-1 transactivation and cell proliferation were higher in the low catalase cells. An EGF-R inhibitor, AG1478, blocks the higher AP-1 transactivation and cell proliferation of the low catalase 6M90 cells. Tumorigenesis in SCID mice was greatly diminished in the high catalase cells. Our data suggest that hydrogen peroxide functions as a signaling molecule that can modulate activity of a protein tyrosine phosphatase/(s) resulting in phosphorylation of tryrosine/(s) on the EGF-R. Therefore, catalase acts as a tumor-suppressor gene in part by decreasing EGF-R signaling.

  19. Molecular Imaging of Hepatocellular Carcinoma Xenografts with Epidermal Growth Factor Receptor Targeted Affibody Probes

    Directory of Open Access Journals (Sweden)

    Ping Zhao

    2013-01-01

    Full Text Available Hepatocellular carcinoma (HCC is a highly aggressive and lethal cancer. It is typically asymptomatic at the early stage, with only 10%–20% of HCC patients being diagnosed early enough for appropriate surgical treatment. The delayed diagnosis of HCC is associated with limited treatment options and much lower survival rates. Therefore, the early and accurate detection of HCC is crucial to improve its currently dismal prognosis. The epidermal growth factor receptor (EGFR has been reported to be involved in HCC tumorigenesis and to represent an attractive target for HCC imaging and therapy. In this study, an affibody molecule, Ac-Cys-ZEGFR:1907, targeting the extracellular domain of EGFR, was used for the first time to assess its potential to detect HCC xenografts. By evaluating radio- or fluorescent-labeled Ac-Cys-ZEGFR:1907 as a probe for positron emission tomography (PET or optical imaging of HCC, subcutaneous EGFR-positive HCC xenografts were found to be successfully imaged by the PET probe. Thus, affibody-based PET imaging of EGFR provides a promising approach for detecting HCC in vivo.

  20. Epidermal Growth Factor Receptor Is Related to Poor Survival in Glioblastomas: Single-Institution Experience

    Science.gov (United States)

    Choi, Youngmin; Lee, Hyung-Sik; Hur, Won-Joo; Sung, Ki-Han; Kim, Ki-Uk; Choi, Sun-Seob; Kim, Su-Jin; Kim, Dae-Cheol

    2013-01-01

    Purpose There are conflicting results surrounding the prognostic significance of epidermal growth factor receptor (EGFR) status in glioblastoma (GBM) patients. Accordingly, we attempted to assess the influence of EGFR expression on the survival of GBM patients receiving postoperative radiotherapy. Materials and Methods Thirty three GBM patients who had received surgery and postoperative radiotherapy at our institute, between March 1997 and February 2006, were included. The evaluation of EGFR expression with immunohistochemistry was available for 30 patients. Kaplan-Meier survival analysis and Cox regression were used for statistical analysis. Results EGFR was expressed in 23 patients (76.7%), and not expressed in seven (23.3%). Survival in EGFR expressing GBM patients was significantly less than that in non-expressing patients (median survival: 12.5 versus 17.5 months, p=0.013). Patients who received more than 60 Gy showed improved survival over those who received up to 60 Gy (median survival: 17.0 versus 9.0 months, p=0.000). Negative EGFR expression and a higher radiation dose were significantly correlated with improved survival on multivariate analysis. Survival rates showed no differences according to age, sex, and surgical extent. Conclusion The expression of EGFR demonstrated a significantly deleterious effect on the survival of GBM patients. Therefore, approaches targeting EGFR should be considered in potential treatment methods for GBM patients, in addition to current management strategies. PMID:23225805

  1. Radiogenomic correlation in lung adenocarcinoma with epidermal growth factor receptor mutations: Imaging features and histological subtypes

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Su Jin [Seoul National University Bundang Hospital, Department of Radiology, Seongnam-si, Gyeonggi-do (Korea, Republic of); Hanyang University, Department of Radiology, School of Medicine, Seoul (Korea, Republic of); Kim, Tae Jung [Seoul National University Bundang Hospital, Department of Radiology, Seongnam-si, Gyeonggi-do (Korea, Republic of); Samsung Medical Center, Department of Radiology, Seoul (Korea, Republic of); Choi, Yo Won [Hanyang University, Department of Radiology, School of Medicine, Seoul (Korea, Republic of); Park, Jeong-Soo [Dankook Universicity, Department of Biochemistry, College of Medicine, Cheonan (Korea, Republic of); Chung, Jin-Haeng [Seoul National University Bundang Hospital, Department of Pathology, Seongnam-si, Gyeonggi-do (Korea, Republic of); Lee, Kyung Won [Seoul National University Bundang Hospital, Department of Radiology, Seongnam-si, Gyeonggi-do (Korea, Republic of)

    2016-10-15

    To correlate imaging features of resected lung adenocarcinoma with epidermal growth factor receptor (EGFR) mutation and the IASLC/ATS/ERS classification histological subtypes. In 250 consecutive patients with resected lung adenocarcinoma, EGFR mutation status was correlated with demographics, imaging features including ground-glass opacity (GGO) proportion and the IASLC/ATS/ERS classification histological subtypes. EGFR mutations were significantly more frequent in women (54.5 % vs. 38.1 %, p = 0.011) and in never-smokers (54.7 % vs. 35.3 %, p = 0.003). GGO proportion was significantly higher in tumours with EGFR mutation than in those without (30.3 ± 33.8 % vs. 19.0 ± 29.3 %, p = 0.005). EGFR mutation was significantly more frequent in tumours with GGO ≥ 50 % and tumours with any GGO (p = 0.026 and 0.008, respectively). Adenocarcinomas with exon 19 or 21 mutation showed significantly higher GGO proportion than that in EGFR wild-type tumours (p = 0.009 and 0.029, respectively). Absence of GGO was an independent predictor of negative EGFR mutation (odds ratio, 1.81; 95 % confidence interval, 1.16-3.04; p = 0.018). GGO proportion in adenocarcinomas with EGFR mutation was significantly higher than that in EGFR wild-type tumours, and the absence of GGO on CT was an independent predictor of negative EGFR mutation. (orig.)

  2. Dialkoxyquinazolines: Screening Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitors for Potential Tumor Imaging Probes

    International Nuclear Information System (INIS)

    VanBrocklin, Henry F.; Lim, John K.; Coffing, Stephanie L.; Hom, Darren L.; Negash, Kitaw; Ono, Michele Y.; Hanrahan, Stephen M.; Taylor, Scott E.; Vanderpoel, Jennifer L.; Slavik, Sarah M.; Morris, Andrew B.; Riese II, David J.

    2005-01-01

    The epidermal growth factor receptor (EGFR), a long-standing drug development target, is also a desirable target for imaging. Sixteen dialkoxyquinazoline analogs, suitable for labeling with positron-emitting isotopes, have been synthesized and evaluated in a battery of in vitro assays to ascertain their chemical and biological properties. These characteristics provided the basis for the adoption of a selection schema to identify lead molecules for labeling and in vivo evaluation. A newEGFR tyrosine kinase radiometric binding assay revealed that all of the compounds possessed suitable affinity (IC50 = 0.4 - 51 nM) for the EGFR tyrosine kinase. All of the analogs inhibited ligand-induced EGFR tyrosine phosphorylation (IC50 = 0.8 - 20 nM). The HPLC-estimated octanol/water partition coefficients ranged from 2.0-5.5. Four compounds,4-(2'-fluoroanilino)- and 4-(3'-fluoroanilino)-6,7-diethoxyquinazoline as well as 4-(3'-chloroanilino)- and4-(3'-bromoanilino)-6,7-dimethoxyquinazoline, possess the best combination of characteristics that warrant radioisotope labeling and further evaluation in tumor-bearing mice

  3. Prognostic significance of epidermal growth factor receptor (EGFR) over expression in urothelial carcinoma of urinary bladder.

    Science.gov (United States)

    Hashmi, Atif Ali; Hussain, Zubaida Fida; Irfan, Muhammad; Khan, Erum Yousuf; Faridi, Naveen; Naqvi, Hanna; Khan, Amir; Edhi, Muhammad Muzzammil

    2018-06-07

    Epidermal growth factor receptor (EGFR) has been shown to have abnormal expression in many human cancers and is considered as a marker of poor prognosis. Frequency of over expression in bladder cancer has not been studied in our population; therefore we aimed to evaluate the frequency and prognostic significance of EGFR immunohistochemical expression in locoregional population. We performed EGFR immunohistochemistry on 126 cases of bladder cancer and association of EGFR expression with tumor grade, lamina propria invasion, deep muscle invasion and recurrence of disease was evaluated. High EGFR expression was noted in 26.2% (33 cases), 15.1% (19 cases) and 58.7% (74 cases) revealed low and no EGFR expression respectively. Significant association of EGFR expression was noted with tumor grade, lamina propria invasion, deep muscle invasion and recurrence status while no significant association was seen with age, gender and overall survival. Kaplan- Meier curves revealed significant association of EGFR expression with recurrence while no significant association was seen with overall survival. Significant association of EGFR overexpression with tumor grade, muscularis propria invasion and recurrence signifies its prognostic value; therefore EGFR can be used as a prognostic biomarker in Urothelial bladder carcinoma.

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

    Directory of Open Access Journals (Sweden)

    Jeffrey C Lee

    2006-12-01

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

  5. Global Developmental Gene Programing Involves a Nuclear Form of Fibroblast Growth Factor Receptor-1 (FGFR1.

    Directory of Open Access Journals (Sweden)

    Christopher Terranova

    Full Text Available Genetic studies have placed the Fgfr1 gene at the top of major ontogenic pathways that enable gastrulation, tissue development and organogenesis. Using genome-wide sequencing and loss and gain of function experiments the present investigation reveals a mechanism that underlies global and direct gene regulation by the nuclear form of FGFR1, ensuring that pluripotent Embryonic Stem Cells differentiate into Neuronal Cells in response to Retinoic Acid. Nuclear FGFR1, both alone and with its partner nuclear receptors RXR and Nur77, targets thousands of active genes and controls the expression of pluripotency, homeobox, neuronal and mesodermal genes. Nuclear FGFR1 targets genes in developmental pathways represented by Wnt/β-catenin, CREB, BMP, the cell cycle and cancer-related TP53 pathway, neuroectodermal and mesodermal programing networks, axonal growth and synaptic plasticity pathways. Nuclear FGFR1 targets the consensus sequences of transcription factors known to engage CREB-binding protein, a common coregulator of transcription and established binding partner of nuclear FGFR1. This investigation reveals the role of nuclear FGFR1 as a global genomic programmer of cell, neural and muscle development.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-03-15

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

  7. Platelet-activating factor receptor agonists mediate xeroderma pigmentosum A photosensitivity.

    Science.gov (United States)

    Yao, Yongxue; Harrison, Kathleen A; Al-Hassani, Mohammed; Murphy, Robert C; Rezania, Samin; Konger, Raymond L; Travers, Jeffrey B

    2012-03-16

    To date, oxidized glycerophosphocholines (Ox-GPCs) with platelet-activating factor (PAF) activity produced non-enzymatically have not been definitively demonstrated to mediate any known disease processes. Here we provide evidence that these Ox-GPCs play a pivotal role in the photosensitivity associated with the deficiency of the DNA repair protein xeroderma pigmentosum type A (XPA). It should be noted that XPA-deficient cells are known to have decreased antioxidant defenses. These studies demonstrate that treatment of human XPA-deficient fibroblasts with the pro-oxidative stressor ultraviolet B (UVB) radiation resulted in increased reactive oxygen species and PAF receptor (PAF-R) agonistic activity in comparison with gene-corrected cells. The UVB irradiation-generated PAF-R agonists were inhibited by antioxidants. UVB irradiation of XPA-deficient (Xpa-/-) mice also resulted in increased PAF-R agonistic activity and skin inflammation in comparison with control mice. The increased UVB irradiation-mediated skin inflammation and TNF-α production in Xpa-/- mice were blocked by systemic antioxidants and by PAF-R antagonists. Structural characterization of PAF-R-stimulating activity in UVB-irradiated XPA-deficient fibroblasts using mass spectrometry revealed increased levels of sn-2 short-chain Ox-GPCs along with native PAF. These studies support a critical role for PAF-R agonistic Ox-GPCs in the pathophysiology of XPA photosensitivity.

  8. Humanized versus murine anti-human epidermal growth factor receptor monoclonal antibodies for immunoscintigraphic studies

    Energy Technology Data Exchange (ETDEWEB)

    Morales, Alejo A. Morales; Duconge, Jorge; Alvarez-Ruiz, Daniel; Becquer-Viart, Maria de Los Angeles; Nunez-Gandolff, Gilda; Fernandez, Eduardo; Caballero-Torres, Idania; Iznaga-Escobar, Normando

    2000-02-01

    The anti-human epidermal growth factor receptor (EGF-R) humanized antibody h-R3 (IgG{sub 1}), which binds to an extracellular domain of EGF-R, was used to evaluate the biodistribution on nude mice xenografted with A431 epidermoid carcinoma cell line. Results are compared with its murine version ior egf/r3 monoclonal antibody (mAb). Twenty-one athymic female 4NMRI nu/nu mice were injected intravenously with 10 {mu}g/100 {mu}Ci of {sup 99m}Tc-labeled mAbs. The mAb ior C5 that recognizes an antigen expressed preferentially on the surface of malignant and cytoplasm of normal colorectal cells was used as negative control. Immunoreactivity of {sup 99m}Tc-labeled mAbs was measured by enzyme linked immunosorbent assay on A431 cell line and the immunoreactive fractions determined by Lindmo method. Among all organs significant accumulation was found in tumor (6.14{+-}2.50 %ID/g, 5.06{+-}2.61 %ID/g for murine and humanized mAbs, respectively) 4 h after injection. The immunoreactive fractions were found to be 0.88 and 0.81 for murine and humanized mAb, respectively. Thus, we expect better results using the humanized mAb h-R3 for diagnostic immunoscintigraphy.

  9. Humanized versus murine anti-human epidermal growth factor receptor monoclonal antibodies for immunoscintigraphic studies

    International Nuclear Information System (INIS)

    Morales, Alejo A. Morales; Duconge, Jorge; Alvarez-Ruiz, Daniel; Becquer-Viart, Maria de Los Angeles; Nunez-Gandolff, Gilda; Fernandez, Eduardo; Caballero-Torres, Idania; Iznaga-Escobar, Normando

    2000-01-01

    The anti-human epidermal growth factor receptor (EGF-R) humanized antibody h-R3 (IgG 1 ), which binds to an extracellular domain of EGF-R, was used to evaluate the biodistribution on nude mice xenografted with A431 epidermoid carcinoma cell line. Results are compared with its murine version ior egf/r3 monoclonal antibody (mAb). Twenty-one athymic female 4NMRI nu/nu mice were injected intravenously with 10 μg/100 μCi of 99m Tc-labeled mAbs. The mAb ior C5 that recognizes an antigen expressed preferentially on the surface of malignant and cytoplasm of normal colorectal cells was used as negative control. Immunoreactivity of 99m Tc-labeled mAbs was measured by enzyme linked immunosorbent assay on A431 cell line and the immunoreactive fractions determined by Lindmo method. Among all organs significant accumulation was found in tumor (6.14±2.50 %ID/g, 5.06±2.61 %ID/g for murine and humanized mAbs, respectively) 4 h after injection. The immunoreactive fractions were found to be 0.88 and 0.81 for murine and humanized mAb, respectively. Thus, we expect better results using the humanized mAb h-R3 for diagnostic immunoscintigraphy

  10. Biologic effects of platelet-derived growth factor receptor α blockade in uterine cancer.

    Science.gov (United States)

    Roh, Ju-Won; Huang, Jie; Hu, Wei; Yang, XiaoYun; Jennings, Nicholas B; Sehgal, Vasudha; Sohn, Bo Hwa; Han, Hee Dong; Lee, Sun Joo; Thanapprapasr, Duangmani; Bottsford-Miller, Justin; Zand, Behrouz; Dalton, Heather J; Previs, Rebecca A; Davis, Ashley N; Matsuo, Koji; Lee, Ju-Seog; Ram, Prahlad; Coleman, Robert L; Sood, Anil K

    2014-05-15

    Platelet-derived growth factor receptor α (PDGFRα) expression is frequently observed in many kinds of cancer and is a candidate for therapeutic targeting. This preclinical study evaluated the biologic significance of PDGFRα and PDGFRα blockade (using a fully humanized monoclonal antibody, 3G3) in uterine cancer. Expression of PDGFRα was examined in uterine cancer clinical samples and cell lines, and biologic effects of PDGFRα inhibition were evaluated using in vitro (cell viability, apoptosis, and invasion) and in vivo (orthotopic) models of uterine cancer. PDGFRα was highly expressed and activated in uterine cancer samples and cell lines. Treatment with 3G3 resulted in substantial inhibition of PDGFRα phosphorylation and of downstream signaling molecules AKT and mitogen-activated protein kinase (MAPK). Cell viability and invasive potential of uterine cancer cells were also inhibited by 3G3 treatment. In orthotopic mouse models of uterine cancer, 3G3 monotherapy had significant antitumor effects in the PDGFRα-positive models (Hec-1A, Ishikawa, Spec-2) but not in the PDGFRα-negative model (OVCA432). Greater therapeutic effects were observed for 3G3 in combination with chemotherapy than for either drug alone in the PDGFRα-positive models. The antitumor effects of therapy were related to increased apoptosis and decreased proliferation and angiogenesis. These findings identify PDGFRα as an attractive target for therapeutic development in uterine cancer. ©2014 American Association for Cancer Research.

  11. Targeting the Insulin-Like Growth Factor 1 Receptor in Ewing's Sarcoma: Reality and Expectations

    Directory of Open Access Journals (Sweden)

    David Olmos

    2011-01-01

    Full Text Available Ewing's sarcoma family of tumours comprises a group of very aggressive diseases that are potentially curable with multimodality treatment. Despite the undoubted success of current treatment, approximately 30% of patients will relapse and ultimately die of disease. The insulin-like growth factor 1 receptor (IGF-1R has been implicated in the genesis, growth, proliferation, and the development of metastatic disease in Ewing's sarcoma. In addition, IGF1-R has been validated, both in vitro and in vivo, as a potential therapeutic target in Ewing's sarcoma. Phase I studies of IGF-1R monoclonal antibodies reported several radiological and clinical responses in Ewing's sarcoma patients, and initial reports of several Phase II studies suggest that about a fourth of the patients would benefit from IGF-1R monoclonal antibodies as single therapy, with approximately 10% of patients achieving objective responses. Furthermore, these therapies are well tolerated, and thus far severe toxicity has been rare. Other studies assessing IGF-1R monoclonal antibodies in combination with traditional cytotoxics or other targeted therapies are expected. Despite, the initial promising results, not all patients benefit from IGF-1R inhibition, and consequently, there is an urgent need for the identification of predictive markers of response.

  12. Targeting the Insulin-Like Growth Factor 1 Receptor in Ewing's Sarcoma: Reality and Expectations

    Science.gov (United States)

    Olmos, David; Martins, Ana Sofia; Jones, Robin L.; Alam, Salma; Scurr, Michelle; Judson, Ian R.

    2011-01-01

    Ewing's sarcoma family of tumours comprises a group of very aggressive diseases that are potentially curable with multimodality treatment. Despite the undoubted success of current treatment, approximately 30% of patients will relapse and ultimately die of disease. The insulin-like growth factor 1 receptor (IGF-1R) has been implicated in the genesis, growth, proliferation, and the development of metastatic disease in Ewing's sarcoma. In addition, IGF1-R has been validated, both in vitro and in vivo, as a potential therapeutic target in Ewing's sarcoma. Phase I studies of IGF-1R monoclonal antibodies reported several radiological and clinical responses in Ewing's sarcoma patients, and initial reports of several Phase II studies suggest that about a fourth of the patients would benefit from IGF-1R monoclonal antibodies as single therapy, with approximately 10% of patients achieving objective responses. Furthermore, these therapies are well tolerated, and thus far severe toxicity has been rare. Other studies assessing IGF-1R monoclonal antibodies in combination with traditional cytotoxics or other targeted therapies are expected. Despite, the initial promising results, not all patients benefit from IGF-1R inhibition, and consequently, there is an urgent need for the identification of predictive markers of response. PMID:21647361

  13. Tumor necrosis factor-alpha and its receptors in epithelial ovarian cancer.

    Directory of Open Access Journals (Sweden)

    Jacek Nikliński

    2010-05-01

    Full Text Available The aim of the present study was to characterize the expression pattern of tumor necrosis factor (TNF-alpha and its receptors (TNF-Rs in the epithelial ovarian cancer (EOC and compare these results with the outcome of 126 patients. Presence of TNF-alpha, TNFR-1 and TNFR-2 were studied by Western blotting and immunohistochemistry. The proportion of samples positive for TNF-alpha and TNF-R2 was higher in epithelial ovarian cancer patients than in benign ovarian diseases (p<0.001 and p=0.016, respectively. Immunostaining intensity of TNF-R2 were correlated with tumor stage (p<0.001 and with reduced mean survival time (MST (p=0.002. The results of the present study suggested that tissue expression of TNF-R2 in epithelial ovarian cancer was correlated with the highest risk of cancer progression. Thus, the clinical value of activated TNF system in epithelial ovarian cancer needs to be further investigated.

  14. Aberrant Receptor Internalization and Enhanced FRS2-dependent Signaling Contribute to the Transforming Activity of the Fibroblast Growth Factor Receptor 2 IIIb C3 Isoform*

    Science.gov (United States)

    Cha, Jiyoung Y.; Maddileti, Savitri; Mitin, Natalia; Harden, T. Kendall; Der, Channing J.

    2009-01-01

    Alternative splice variants of fibroblast growth factor receptor 2 (FGFR2) IIIb, designated C1, C2, and C3, possess progressive reduction in their cytoplasmic carboxyl termini (822, 788, and 769 residues, respectively), with preferential expression of the C2 and C3 isoforms in human cancers. We determined that the progressive deletion of carboxyl-terminal sequences correlated with increasing transforming potency. The highly transforming C3 variant lacks five tyrosine residues present in C1, and we determined that the loss of Tyr-770 alone enhanced FGFR2 IIIb C1 transforming activity. Because Tyr-770 may compose a putative YXXL sorting motif, we hypothesized that loss of Tyr-770 in the 770YXXL motif may cause disruption of FGFR2 IIIb C1 internalization and enhance transforming activity. Surprisingly, we found that mutation of Leu-773 but not Tyr-770 impaired receptor internalization and increased receptor stability and activation. Interestingly, concurrent mutations of Tyr-770 and Leu-773 caused 2-fold higher transforming activity than caused by the Y770F or L773A single mutations, suggesting loss of Tyr and Leu residues of the 770YXXL773 motif enhances FGFR2 IIIb transforming activity by distinct mechanisms. We also determined that loss of Tyr-770 caused persistent activation of FRS2 by enhancing FRS2 binding to FGFR2 IIIb. Furthermore, we found that FRS2 binding to FGFR2 IIIb is required for increased FRS2 tyrosine phosphorylation and enhanced transforming activity by Y770F mutation. Our data support a dual mechanism where deletion of the 770YXXL773 motif promotes FGFR2 IIIb C3 transforming activity by causing aberrant receptor recycling and stability and persistent FRS2-dependent signaling. PMID:19103595

  15. Expression of factors and key components associated with the PI3K signaling pathway in colon cancer.

    Science.gov (United States)

    Chen, Hua; Gao, Junyi; Du, Zhenhua; Zhang, Xuequn; Yang, Fei; Gao, Wei

    2018-04-01

    The pathophysiology of colorectal cancer (CRC) has not been fully elucidated. The dysregulation of the phosphatidylinositol 3-kinase (PI3K) signaling pathway frequently contributes to the tumorigenesis and progression of human cancer. The aim of the present study was to explore the expression and clinical significance of a number of associated factors and key components of the PI3K signaling pathway, including phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit α (p110α), phosphorylated protein kinase B (p-Akt) Ser473, p-mammalian target of rapamycin (mTOR) Ser2448, cyclin D1, cyclin dependent kinase (CDK)4, RELA proto-oncogene, nuclear factor-κβ subunit (p65), Ras and extracellular signal-regulated kinase (ERK)1/2 in human CRC. The expression of target proteins was detected using immunohistochemistry (IHC) in 65 CRC cases and 15 colonic adenoma cases. The association between the expression of target proteins and clinical pathological parameters was analyzed using a χ 2 test. IHC results revealed that the expression of all target proteins was significantly increased in CRC tissues compared with in colonic adenoma tissues (P0.05). Cyclin D1, CDK4 and Ras were revealed to be expressed significantly higher in poorly differentiated CRC compared with moderately differentiated CRC (Pcancer tissues with lymph node metastasis compared with cancer tissues without lymph node metastasis (P<0.05). These results suggest that the target proteins may all participate in the tumorigenesis of CRC. Furthermore, cyclin D1, CDK4, Ras, p65 and ERK1/2 may be important in the progression of CRC. The results of the present study may provide novel predictive factors and therapeutic targets for CRC.

  16. The expression of receptors for estrogen and epithelial growth factor in the male rabbit prostate and prostatic urethra following castration

    DEFF Research Database (Denmark)

    Bødker, A; Balslev, E; Iversen, H G

    1997-01-01

    In the lower urinary tract of the male rabbit, estrogen receptors (ERs) are restricted to the urethra and the prostatic stroma. At present, the function of ERs in these tissues is not known. Epithelial growth factor (EGF) stimulates proliferation of epidermal and epithelial tissues, and several...... were included as controls. In the control group, ERs were found in the urothelial lining and lamina propria of the prostatic urethra, and in the prostatic stroma. EGF receptors were demonstrated in the epithelial lining of the prostatic urethra and the glandular epithelium of the prostate. Following...... castration, the expression of ERs, assessed as the increase in the number of positively stained specimens, increased significantly in the lamina propria of the prostatic urethra and the prostatic stroma. EGF receptor expression increased significantly in the epithelial lining of the prostatic urethra...

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

    Directory of Open Access Journals (Sweden)

    Hartley Judith

    2007-04-01

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

  18. Differences in human skin between the epidermal growth factor receptor distribution detected by EGF binding and monoclonal antibody recognition

    DEFF Research Database (Denmark)

    Green, M R; Couchman, J R

    1985-01-01

    , the eccrine sweat glands, capillary system, and the hair follicle outer root sheath, generally similar in pattern to that previously reported for full-thickness rat skin and human epidermis. The same areas also bound EGF-R1 but in addition the monoclonal antibody recognized a cone of melanin containing......Two methods have been used to examine epidermal growth factor (EGF) receptor distribution in human scalp and foreskin. The first employed [125I]EGF viable explants and autoradiography to determine the EGF binding pattern while the second used a monoclonal antibody to the human EGF receptor to map...... whether EGF-R1 could recognize molecules unrelated to the EGF receptor, the EGF binding and EGF-R1 recognition profiles were compared on cultures of SVK14 cells, a SV40 transformed human keratinocyte cell line. EGF binding and EGF-R1 monoclonal antibody distribution on these cells was found to be similar...

  19. Insulin-like growth factor type-1 receptor down-regulation associated with dwarfism in Holstein calves.

    Science.gov (United States)

    Blum, J W; Elsasser, T H; Greger, D L; Wittenberg, S; de Vries, F; Distl, O

    2007-10-01

    Perturbations in endocrine functions can impact normal growth. Endocrine traits were studied in three dwarf calves exhibiting retarded but proportionate growth and four phenotypically normal half-siblings, sired by the same bull, and four unrelated control calves. Plasma 3,5,3'-triiodothyronine and thyroxine concentrations in dwarfs and half-siblings were in the physiological range and responded normally to injected thyroid-releasing hormone. Plasma glucagon concentrations were different (dwarfs, controls>half-siblings; Pcontrols, Pcontrols, P=0.08). Responses of GH to xylazine and to a GH-releasing-factor analogue were similar in dwarfs and half-siblings. Relative gene expression of IGF-1, IGF-2, GH receptor (GHR), insulin receptor, IGF-1 type-1 and -2 receptors (IGF-1R, IGF-2R), and IGF binding proteins were measured in liver and anconeus muscle. GHR mRNA levels were different in liver (dwarfsdwarfism in studied calves.

  20. Retrospective study of adjuvant icotinib in postoperative lung cancer patients harboring epidermal growth factor receptor mutations.

    Science.gov (United States)

    Yao, Shuyang; Zhi, Xiuyi; Wang, Ruotian; Qian, Kun; Hu, Mu; Zhang, Yi

    2016-09-01

    Epidermal growth factor receptor (EGFR) mutations occur in about 50% of Asian patients with non-small cell lung cancer (NSCLC). Patients with advanced NSCLC and EGFR mutations derive clinical benefit from treatment with EGFR-tyrosine kinase inhibitors (TKIs). This study assessed the efficacy and safety of adjuvant icotinib without chemotherapy in EGFR-mutated NSCLC patients undergoing resection of stage IB-IIIA. Our retrospective study enrolled 20 patients treated with icotinib as adjuvant therapy. Survival factors were evaluated by univariate and Cox regression analysis. The median follow-up time was 30 months (range 24-41). At the data cut-off, five patients (25%) had recurrence or metastasis and one patient had died of the disease. The two-year disease-free survival (DFS) rate was 85%. No recurrence occurred in the high-risk stage IB subgroup during the follow-up period. In univariate analysis, the micropapillary pattern had a statistically significant effect on DFS ( P = 0.040). Multivariate logistic regression analysis showed that there was no independent predictor. Drug related adverse events (AEs) occurred in nine patients (45.0%). The most common AEs were skin-related events and diarrhea, but were relatively mild. No grade 3 AEs or occurrences of intolerable toxicity were observed. Icotinib as adjuvant therapy is effective in patients harboring EGFR mutations after complete resection, with an acceptable AE profile. Further trials with larger sample sizes might confirm the efficiency of adjuvant TKI in selected patients. © 2016 The Authors. Thoracic Cancer published by China Lung Oncology Group and John Wiley & Sons Australia, Ltd.

  1. Correlation between 18F Fluorodeoxyglucose uptake and epidermal growth factor receptor mutations in advanced lung cancer

    International Nuclear Information System (INIS)

    Choi, Yun Jung; Cho, Byoung Chul; Jeong, Youg Hyu; Seo, Hyo Jung; Kim, Hyun Jeong; Cho, Arthur; Lee, Jae Hoon; Yun, Mi Jin; Jeon, Tae Joo; Lee, Jong Doo; Kang, Won Jun

    2012-01-01

    Mutations in the epidermal growth factor receptor (EGFR)gene have been identified as potential targets for the treatment and prognostic factors for non small cell lung cancer (NSCLC). We assessed the correlation between fluorodeoxyglucose (FDG) uptake and EGFR mutations, as well as their prognostic implications. A total of 163 patients with pathologically confirmed NSCLC were enrolled (99 males and 64 females; median age, 60 years). All patients underwent FDG positron emission tomography before treatment, and genetic studies of EGFR mutations were performed. The maximum standardized uptake value (SUVmax)of the primary lung cancer was measured and normalized with regard to liver uptake. The SUVmax between the wild type and EGFR mutant groups was compared. Survival was evaluated according to SUVmax and EGFR mutation status. EGFR mutations were found in 57 patients (60.8%). The SUVmax tended to be higher in wild type than mutant tumors, but was not significantly different (11.1±5.7 vs. 9.8±4.4, P=0.103). The SUVmax was significantly lower in patients with an exon 19 mutation than in those with either an exon 21 mutation or wild type (P=0.003 and 0.009, respectively). The EGFR mutation showed prolonged overall survival (OS) compared to wild type tumors (P=0.004). There was no significant difference in survival according to SUVmax. Both OS and progression free survival of patients with a mutation in exon 19 were significant longer than in patients with wild type tumors. In patients with NSCLC, a mutation in exon 19 was associated with a lower SUVmax and is a reliable predictor for good survival

  2. Soluble N-ethylmaleimide-sensitive factor attachment protein receptors required during Trypanosoma cruzi parasitophorous vacuole development.

    Science.gov (United States)

    Cueto, Juan Agustín; Vanrell, María Cristina; Salassa, Betiana Nebaí; Nola, Sébastien; Galli, Thierry; Colombo, María Isabel; Romano, Patricia Silvia

    2017-06-01

    Trypanosoma cruzi, the etiologic agent of Chagas disease, is an obligate intracellular parasite that exploits different host vesicular pathways to invade the target cells. Vesicular and target soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs) are key proteins of the intracellular membrane fusion machinery. During the early times of T. cruzi infection, several vesicles are attracted to the parasite contact sites in the plasma membrane. Fusion of these vesicles promotes the formation of the parasitic vacuole and parasite entry. In this work, we study the requirement and the nature of SNAREs involved in the fusion events that take place during T. cruzi infection. Our results show that inhibition of N-ethylmaleimide-sensitive factor protein, a protein required for SNARE complex disassembly, impairs T. cruzi infection. Both TI-VAMP/VAMP7 and cellubrevin/VAMP3, two v-SNAREs of the endocytic and exocytic pathways, are specifically recruited to the parasitophorous vacuole membrane in a synchronized manner but, although VAMP3 is acquired earlier than VAMP7, impairment of VAMP3 by tetanus neurotoxin fails to reduce T. cruzi infection. In contrast, reduction of VAMP7 activity by expression of VAMP7's longin domain, depletion by small interfering RNA or knockout, significantly decreases T. cruzi infection susceptibility as a result of a minor acquisition of lysosomal components to the parasitic vacuole. In addition, overexpression of the VAMP7 partner Vti1b increases the infection, whereas expression of a KIF5 kinesin mutant reduces VAMP7 recruitment to vacuole and, concomitantly, T. cruzi infection. Altogether, these data support a key role of TI-VAMP/VAMP7 in the fusion events that culminate in the T. cruzi parasitophorous vacuole development. © 2016 John Wiley & Sons Ltd.

  3. Covalent Targeting of Fibroblast Growth Factor Receptor Inhibits Metastatic Breast Cancer.

    Science.gov (United States)

    Brown, Wells S; Tan, Li; Smith, Andrew; Gray, Nathanael S; Wendt, Michael K

    2016-09-01

    Therapeutic targeting of late-stage breast cancer is limited by an inadequate understanding of how tumor cell signaling evolves during metastatic progression and by the currently available small molecule inhibitors capable of targeting these processes. Herein, we demonstrate that both β3 integrin and fibroblast growth factor receptor-1 (FGFR1) are part of an epithelial-mesenchymal transition (EMT) program that is required to facilitate metastatic outgrowth in response to fibroblast growth factor-2 (FGF2). Mechanistically, β3 integrin physically disrupts an interaction between FGFR1 and E-cadherin, leading to a dramatic redistribution of FGFR1 subcellular localization, enhanced FGF2 signaling and increased three-dimensional (3D) outgrowth of metastatic breast cancer cells. This ability of β3 integrin to drive FGFR signaling requires the enzymatic activity of focal adhesion kinase (FAK). Consistent with these mechanistic data, we demonstrate that FGFR, β3 integrin, and FAK constitute a molecular signature capable of predicting decreased survival of patients with the basal-like subtype of breast cancer. Importantly, covalent targeting of a conserved cysteine in the P-loop of FGFR1-4 with our newly developed small molecule, FIIN-4, more effectively blocks 3D metastatic outgrowth as compared with currently available FGFR inhibitors. In vivo application of FIIN-4 potently inhibited the growth of metastatic, patient-derived breast cancer xenografts and murine-derived metastases growing within the pulmonary microenvironment. Overall, the current studies demonstrate that FGFR1 works in concert with other EMT effector molecules to drive aberrant downstream signaling, and that these events can be effectively targeted using our novel therapeutics for the treatment of the most aggressive forms of breast cancer. Mol Cancer Ther; 15(9); 2096-106. ©2016 AACR. ©2016 American Association for Cancer Research.

  4. Effects of epidermal growth factor receptor kinase inhibition on radiation response in canine osteosarcoma cells.

    Science.gov (United States)

    Mantovani, Fernanda B; Morrison, Jodi A; Mutsaers, Anthony J

    2016-05-31

    Radiation therapy is a palliative treatment modality for canine osteosarcoma, with transient improvement in analgesia observed in many cases. However there is room for improvement in outcome for these patients. It is possible that the addition of sensitizing agents may increase tumor response to radiation therapy and prolong quality of life. Epidermal growth factor receptor (EGFR) expression has been documented in canine osteosarcoma and higher EGFR levels have been correlated to a worse prognosis. However, effects of EGFR inhibition on radiation responsiveness in canine osteosarcoma have not been previously characterized. This study examined the effects of the small molecule EGFR inhibitor erlotinib on canine osteosarcoma radiation responses, target and downstream protein expression in vitro. Additionally, to assess the potential impact of treatment on tumor angiogenesis, vascular endothelial growth factor (VEGF) levels in conditioned media were measured. Erlotinib as a single agent reduced clonogenic survival in two canine osteosarcoma cell lines and enhanced the impact of radiation in one out of three cell lines investigated. In cell viability assays, erlotinib enhanced radiation effects and demonstrated single agent effects. Erlotinib did not alter total levels of EGFR, nor inhibit downstream protein kinase B (PKB/Akt) activation. On the contrary, erlotinib treatment increased phosphorylated Akt in these osteosarcoma cell lines. VEGF levels in conditioned media increased after erlotinib treatment as a single agent and in combination with radiation in two out of three cell lines investigated. However, VEGF levels decreased with erlotinib treatment in the third cell line. Erlotinib treatment promoted modest enhancement of radiation effects in canine osteosarcoma cells, and possessed activity as a single agent in some cell lines, indicating a potential role for EGFR inhibition in the treatment of a subset of osteosarcoma patients. The relative radioresistance of

  5. Soluble tumor necrosis factor receptor-I in preterm infants with chorioamnionitis.

    Science.gov (United States)

    Sato, Miho; Nishimaki, Shigeru; An, Hiromi; Shima, Yoshio; Naruto, Takuya; Sugai, Toshiyuki; Iwasaki, Shiho; Seki, Kazuo; Imagawa, Tomoyuki; Mori, Masaaki; Yokota, Shumpei

    2009-04-01

    The aim of our study was (i) to determine whether chorioamnionitis (CAM) is associated with an elevated soluble tumor necrosis factor receptor I (sTNFR-I) level and (ii) to examine the time course of the concentration of sTNFR-I in preterm infants after birth. We measured sTNFR-I levels in the cord blood of 112 preterm infants (gestational age < or =34 weeks), and those in peripheral blood of 30 preterm infants on days 7, 14, 21 and 28. The median value for the sTNFR-I was significantly elevated in 33 infants with CAM at stage 3 (4618 pg/mL) compared with the 52 infants without CAM (2866 pg/mL), or the 13 infants with CAM at stage 1 (3638 pg/mL) and the 14 infants at stage 2 (3242 pg/mL). The severity of CAM is an independent factor for the elevation of cord blood sTNFR-I. The sTNFR-I level on day 0 was significantly higher in eight infants with CAM at stage 3 than in the 22 infants without CAM or with CAM at stage 1 and 2; however there were no significant differences on days 7, 14, 21 and 28. The serum level of sTNFR-I showed a significant gradual decline with time. We suggest that there is an association between elevated sTNFR-I levels in cord blood and maternal CAM, and this elevation may reflect the fetal inflammation. However the elevation of sTNFR-I could not persist postnatally for a long time.

  6. Epidermal growth factor receptor signaling mediates aldosterone-induced profibrotic responses in kidney

    Energy Technology Data Exchange (ETDEWEB)

    Sheng, Lili; Yang, Min; Ding, Wei [Department of Nephrology, Shanghai Fifth People' s Hospital, Fudan University, Shanghai 200240 (China); Zhang, Minmin [Department of Nephrology, Shanghai Huashan Hospital, Fudan University, Shanghai 200240 (China); Niu, Jianying [Department of Nephrology, Shanghai Fifth People' s Hospital, Fudan University, Shanghai 200240 (China); Qiao, Zhongdong [School of Life Science and Biotechnology, Shanghai Jiaotong University, Shanghai 200240 (China); Gu, Yong, E-mail: yonggu@vip.163.com [Department of Nephrology, Shanghai Fifth People' s Hospital, Fudan University, Shanghai 200240 (China); Department of Nephrology, Shanghai Huashan Hospital, Fudan University, Shanghai 200240 (China)

    2016-08-01

    Aldosterone has been recognized as a risk factor for the development of chronic kidney disease (CKD). Studies have indicated that enhanced activation of epidermal growth factor receptor (EGFR) is associated with the development and progression of renal fibrosis. But if EGFR is involved in aldosterone-induced renal fibrosis is less investigated. In the present study, we examined the effect of erlotinib, an inhibitor of EGFR tyrosine kinase activity, on the progression of aldosterone-induced renal profibrotic responses in a murine model underwent uninephrectomy. Erlotinib-treated rats exhibited relieved structural lesion comparing with rats treated with aldosterone alone, as characterized by glomerular hypertrophy, mesangial cell proliferation and expansion. Also, erlotinib inhibited the expression of TGF-β, α-SMA and mesangial matrix proteins such as collagen Ⅳ and fibronectin. In cultured mesangial cells, inhibition of EGFR also abrogated aldosterone-induced expression of extracellular matrix proteins, cell proliferation and migration. We also demonstrated that aldosterone induced the phosphorylation of EGFR through generation of ROS. And the activation of EGFR resulted in the phosphorylation of ERK1/2, leading to the activation of profibrotic pathways. Taken together, we concluded that aldosterone-mediated tissue fibrosis relies on ROS induced EGFR/ERK activation, highlighting EGFR as a potential therapeutic target for modulating renal fibrosis. - Highlights: • EGFR was involved in aldosterone-induced renal profibrotic responses. • Aldosterone-induced EGFR activation was mediated by MR-dependent ROS generation. • EGFR activated the MAPK/ERK1/2 signaling to promote renal fibrosis.

  7. Sigma-1 receptor chaperone and brain-derived neurotrophic factor: emerging links between cardiovascular disease and depression.

    Science.gov (United States)

    Hashimoto, Kenji

    2013-01-01

    Epidemiological studies have demonstrated a close relationship between depression and cardiovascular disease (CVD). Although it is known that the central nervous system (CNS) contributes to this relationship, the detailed mechanisms involved in this process remain unclear. Recent studies suggest that the endoplasmic reticulum (ER) molecular chaperone sigma-1 receptor and brain-derived neurotrophic factor (BDNF) play a role in the pathophysiology of CVD and depression. Several meta-analysis studies have showed that levels of BDNF in the blood of patients with major depressive disorder (MDD) are lower than normal controls, indicating that blood BDNF might be a biomarker for depression. Furthermore, blood levels of BDNF in patients with CVD are also lower than normal controls. A recent study using conditional BDNF knock-out mice in animal models of myocardial infarction highlighted the role of CNS-mediated mechanisms in the cardioprotective effects of BDNF. In addition, a recent study shows that decreased levels of sigma-1 receptor in the mouse brain contribute to the association between heart failure and depression. Moreover, sigma-1 receptor agonists, including the endogenous neurosteroid dehydroepiandosterone (DHEA) and the selective serotonin reuptake inhibitor (SSRI) fluvoxamine, show potent cardioprotective and antidepressive effects in rodents, via sigma-1 receptor stimulation. Interestingly, agonist activation of sigma-1 receptors increased the secretion of mature BDNF from its precursor proBDNF via chaperone activity in the ER. Given the role of ER stress in the pathophysiology of CVD and MDD, the author will discuss the potential link between sigma-1 receptors and BDNF-TrkB pathway in the pathophysiology of these two diseases. Finally, the author will make a case for potent sigma-1 receptor agonists and TrkB agonists as new potential therapeutic drugs for depressive patients with CVD. Copyright © 2012 Elsevier Ltd. All rights reserved.

  8. Quantitative assessment of fibroblast growth factor receptor 1 expression in neurons and glia

    Directory of Open Access Journals (Sweden)

    Lisha Choubey

    2017-04-01

    Full Text Available Background Fibroblast growth factors (FGFs and their receptors (FGFRs have numerous functions in the developing and adult central nervous system (CNS. For example, the FGFR1 receptor is important for proliferation and fate specification of radial glial cells in the cortex and hippocampus, oligodendrocyte proliferation and regeneration, midline glia morphology and soma translocation, Bergmann glia morphology, and cerebellar morphogenesis. In addition, FGFR1 signaling in astrocytes is required for postnatal maturation of interneurons expressing parvalbumin (PV. FGFR1 is implicated in synapse formation in the hippocampus, and alterations in the expression of Fgfr1 and its ligand, Fgf2 accompany major depression. Understanding which cell types express Fgfr1 during development may elucidate its roles in normal development of the brain as well as illuminate possible causes of certain neuropsychiatric disorders. Methods Here, we used a BAC transgenic reporter line to trace Fgfr1 expression in the developing postnatal murine CNS. The specific transgenic line employed was created by the GENSAT project, tgFGFR1-EGFPGP338Gsat, and includes a gene encoding enhanced green fluorescent protein (EGFP under the regulation of the Fgfr1 promoter, to trace Fgfr1 expression in the developing CNS. Unbiased stereological counts were performed for several cell types in the cortex and hippocampus. Results This model reveals that Fgfr1 is primarily expressed in glial cells, in both astrocytes and oligodendrocytes, along with some neurons. Dual labeling experiments indicate that the proportion of GFP+ (Fgfr1+ cells that are also GFAP+ increases from postnatal day 7 (P7 to 1 month, illuminating dynamic changes in Fgfr1 expression during postnatal development of the cortex. In postnatal neurogenic areas, GFP expression was also observed in SOX2, doublecortin (DCX, and brain lipid-binding protein (BLBP expressing cells. Fgfr1 is also highly expressed in DCX positive cells of

  9. Alterations in epidermal growth factor receptors 1 and 2 in esophageal squamous cell carcinomas

    International Nuclear Information System (INIS)

    Gonzaga, Isabela Martins; Andreollo, Nelson Adami; Simão, Tatiana Almeida de; Pinto, Luis Felipe Ribeiro; Soares-Lima, Sheila Coelho; Santos, Paulo Thiago Souza de; Blanco, Tania Cristina Moita; Reis, Bruno Souza Bianchi de; Quintella, Danielle Carvalho; Oliveira, Ivanir Martins de; Faria, Paulo Antonio Silvestre de; Kruel, Cleber Dario Pinto

    2012-01-01

    Esophageal squamous cell carcinoma (ESCC) shows a 5-year survival rate below 10%, demonstrating the urgency in improving its treatment. Alterations in epidermal growth factor receptors are closely related to malignancy transformation in a number of tumors and recent successful targeted therapies have been directed to these molecules. Therefore, in this study, we analyzed the expression of EGFR and HER2 and evaluated EGFR mutation profile as well as the presence of mutations in hotspots of KRAS and BRAF in ESCC patients. We performed RT-qPCR, immunohistochemistry and Fluorescent in situ hybridization to determine EGFR and HER2 expression in ESCC patients, and direct sequencing and PCR-RFLP for mutations and polymorphism analysis. Our results showed an increased EGFR mRNA expression in tumors compared to surrounding tissue (p <0.05), with 11% of the cases presenting at least a four-fold difference between tumor and paired adjacent mucosa. EGFR protein overexpression was present only in 4% of the cases. The median expression of HER2 mRNA was not different between tumors and adjacent mucosa. Still, 7% of the tumors presented at least a 25-fold higher expression of this gene when compared to its paired counterpart. Immunohistochemical analysis revealed that 21% of the tumors were positive for HER2 (scores 2+ and 3+), although only 3+ tumors presented amplification of this gene. Mutation analysis for EGFR (exons 18-21), KRAS (codons 12 and 13) and BRAF (V600E) showed no mutations in any of the hotspots of these genes in almost 100 patients analyzed. EGFR presented synonymous polymorphisms at codon 836 (C>T) in 2.1% of the patients, and at codon 787 (G>A) in 79.2% of the cases. This last polymorphism was also evaluated in 304 healthy controls, which presented a similar frequency (73.7%) in comparison with ESCC patients. The absence of mutations of EGFR, KRAS and BRAF as well as the overexpression of EGFR and HER2 in less than 10% of the patients suggest that this

  10. Revisiting the role of hCG: new regulation of the angiogenic factor EG-VEGF and its receptors.

    Science.gov (United States)

    Brouillet, S; Hoffmann, P; Chauvet, S; Salomon, A; Chamboredon, S; Sergent, F; Benharouga, M; Feige, J J; Alfaidy, N

    2012-05-01

    Endocrine gland-derived vascular endothelial growth factor (EG-VEGF) is an angiogenic factor reported to be specific for endocrine tissues, including the placenta. Its biological activity is mediated via two G protein-coupled receptors, prokineticin receptor 1 (PROKR1) and prokineticin receptor 2 (PROKR2). We have recently shown that (i) EG-VEGF expression peaks between the 8th and 11th weeks of gestation, (ii) its mRNA and protein levels are up-regulated by hypoxia, (iii) EG-VEGF is a negative regulator of trophoblast invasion and (iv) its circulating levels are increased in preeclampsia (PE), the most threatening pathology of pregnancy. Here, we investigated the regulation of the expression of EG-VEGF and its receptors by hCG, a key pregnancy hormone that is also deregulated in PE. During the first trimester of pregnancy, hCG and EG-VEGF exhibit the same pattern of expression, suggesting that EG-VEGF is potentially regulated by hCG. Both placental explants (PEX) and primary cultures of trophoblasts from the first trimester of pregnancy were used to investigate this hypothesis. Our results show that (i) LHCGR, the hCG receptor, is expressed both in cyto- and syncytiotrophoblasts, (ii) hCG increases EG-VEGF, PROKR1 and PROKR2 mRNA and protein expression in a dose- and time-dependent manner, (iii) hCG increases the release of EG-VEGF from PEX conditioned media, (iv) hCG effects are transcriptional and post-transcriptional and (v) the hCG effects are mediated by cAMP via cAMP response elements present in the EG-VEGF promoter region. Altogether, these results demonstrate a new role for hCG in the regulation of EG-VEGF and its receptors, an emerging regulatory system in placental development.

  11. Expression and autoregulation of transforming growth factor beta receptor mRNA in small-cell lung cancer cell lines

    DEFF Research Database (Denmark)

    Nørgaard, P; Spang-Thomsen, M; Poulsen, H S

    1996-01-01

    In small-cell lung cancer cell lines resistance to growth inhibition by transforming growth factor (TGF)-beta 1, was previously shown to correlate with lack of TGF-beta receptor I (RI) and II (RII) proteins. To further investigate the role of these receptors, the expression of mRNA for RI, RII...... and beta-glycan (RIII) was examined. The results showed that loss of RII mRNA correlated with TGF-beta 1 resistance. In contrast, RI-and beta-glycan mRNA was expressed by all cell lines, including those lacking expression of these proteins. According to Southern blot analysis, the loss of type II m......RNA was not due to gross structural changes in the gene. The effect of TGF-beta 1 on expression of TGF-beta receptor mRNA (receptor autoregulation) was examined by quantitative Northern blotting in four cell lines with different expression of TGF-beta receptor proteins. In two cell lines expressing all three TGF...

  12. Affinity purification of human granulocyte macrophage colony-stimulating factor receptor alpha-chain. Demonstration of binding by photoaffinity labeling

    International Nuclear Information System (INIS)

    Chiba, S.; Shibuya, K.; Miyazono, K.; Tojo, A.; Oka, Y.; Miyagawa, K.; Takaku, F.

    1990-01-01

    The human granulocyte macrophage colony-stimulating factor (GM-CSF) receptor alpha-chain, a low affinity component of the receptor, was solubilized and affinity-purified from human placenta using biotinylated GM-CSF. Scatchard analysis of 125 I-GM-CSF binding to the placental membrane extract disclosed that the GM-CSF receptor had a dissociation constant (Kd) of 0.5-0.8 nM, corresponding to the Kd value of the GM-CSF receptor alpha-chain on the intact placental membrane. Affinity labeling of the solubilized protein using a photoreactive cross-linking agent, N-hydroxysuccinimidyl-4-azidobenzoate (HSAB), demonstrated a single specific band of 70-95 kDa representing a ligand-receptor complex. Approximately 2 g of the placental membrane extract was subjected to a biotinylated GM-CSF-fixed streptavidin-agarose column, resulting in a single major band at 70 kDa on a silver-stained sodium dodecyl sulfate gel. The radioiodination for the purified material disclosed that the purified protein had an approximate molecular mass of 70 kDa and a pI of 6.6. Binding activity of the purified material was demonstrated by photoaffinity labeling using HSAB- 125 I-GM-CSF, producing a similar specific band at 70-95 kDa as was demonstrated for the crude protein

  13. The phosphatidylinositol-3 kinase pathway is not essential for insulin-like growth factor I receptor-mediated clonogenic radioresistance

    International Nuclear Information System (INIS)

    Yu, Dong; Watanabe, Hiroshi; Shibuya, Hitoshi; Miura, Masahiko

    2002-01-01

    The insulin-like growth factor I receptor (IGF-IR) is known to induce clonogenic radioresistance in cells following ionizing irradiation. To explore the downstream signaling pathways, we focused on the phosphatidylinositol-3 kinase (PI3-K) pathway, which is thought to be the primary cell survival signal originating from the receptor. For this purpose, R- cells deficient in the endogenous IGF-IR were used as a recipient of the human IGF-IR with or without mutations at potential PI3-K activation sites: NPXY 950 and Y 1316 XXM. Mutats with double mutation at Y950/Y1316 exhibited not abrogated, but reduced activation of insulin receptor substance-1 (IRS-1), PI3-K, and Akt upon IGF-I stimulation. However, the mutants had the same clonogenic radioresistance as cells with wild type (WT) receptors. Neither wortmannin nor LY294002, specific inhibitors of PI3-K, affected the radioresistance of cells with WT receptors at concentrations specific for PI3-K. Collectively, these results indicate that the PI3-K pathway is not essential for IGF-IR-mediated clonogenic radioresistance. (author)

  14. A chimeric receptor of the insulin-like growth factor receptor type 1 (IGFR1) and a single chain antibody specific to myelin oligodendrocyte glycoprotein activates the IGF1R signalling cascade in CG4 oligodendrocyte progenitors

    NARCIS (Netherlands)

    Annenkov, A.; Rigby, A.; Amor, S.; Zhou, D.M.; Yousaf, N.; Hemmer, B.; Chernajovsky, Y.

    2011-01-01

    In order to generate neural stem cells with increased ability to survive after transplantation in brain parenchyma we developed a chimeric receptor (ChR) that binds to myelin oligodendrocyte glycoprotein (MOG) via its ectodomain and activates the insulin-like growth factor receptor type 1 (IGF1R)

  15. 15-Deoxy-Δ12,14-prostaglandin J2 and thiazolidinediones transactivate epidermal growth factor and platelet-derived growth factor receptors in vascular smooth muscle cells

    International Nuclear Information System (INIS)

    Ichiki, Toshihiro; Tokunou, Tomotake; Fukuyama, Kae; Iino, Naoko; Masuda, Satoko; Takeshita, Akira

    2004-01-01

    Proliferation of vascular smooth muscle cells (VSMCs) is induced by various mitogens through activation of extracellular signal-regulated protein kinase (ERK) pathway. We recently reported that peroxisome proliferator-activated receptor (PPAR)γ activators such as 15-deoxy-Δ 12,14 -prostaglandin J2 (15-d-PGJ2) and thiazolidinediones (TZDs) activated MEK/ERK pathway through phosphatidylinositol 3-kinase (PI3-K) and induced proliferation of VSMCs. However, the precise mechanisms of PPARγ activators-induced activation of PI3-K/ERK pathway have not been determined. We examined whether transactivation of growth factor receptor is involved in this process. Stimulation of VSMCs with 15-d-PGJ2 or TZDs for 15 min induced phosphorylation of ERK1/2 and Akt. 15-d-PGJ2- or TZDs-induced phosphorylation of ERK1/2 and Akt was inhibited by AG1478, an inhibitor of epidermal growth factor receptor (EGF-R) as well as AG1295, an inhibitor of platelet derived growth factor receptor (PDGF-R). 15-d-PGJ2-induced phosphorylation of both EGF-R and PDGF-R. GM6001, a matrix metalloproteinase inhibitor, and PP2, a Src family protein kinase inhibitor, suppressed 15-d-PGJ2- and TZDs-induced phosphorylation of EGF-R and PDGFβ-R as well as activation of ERK1/2 and Akt. PDGFβ-R was co-immunoprecipitated with EGF-R, regardless of the presence or absence of 15-d-PGJ2. These data suggest that 15-d-PGJ2 and TZDs activate PI3-K/ERK pathway through Src family kinase- and matrix metalloproteinase-dependent transactivation of EGF-R and PDGF-R. Both receptors seemed to associate constitutively. This novel signaling mechanisms may contribute to diverse biological functions of PPARγ activators

  16. ALTERED EXPRESSION OF SURFACE RECEPTORS AT EA.HY926 ENDOTHELIAL CELL LINE INDUCED WITH PLACENTAL SECRETORY FACTORS

    Directory of Open Access Journals (Sweden)

    O. I. Stepanova

    2012-01-01

    Full Text Available Abstract. Placental cell populations produce a great variety of angiogenic factors and cytokines than control angiogenesis in placenta. Functional regulation of endothelial cells proceeds via modulation of endothelial cell receptors for endogenous angiogenic and apoptotic signals. Endothelial phenotype alteration during normal pregnancy and in cases of preclampsia is not well understood. The goal of this investigation was to evaluate altered expression of angiogenic and cytokine receptors at EA.hy926 endothelial cells under the influence of placental tissue supernatants. Normal placental tissue supernatants from 1st and 3rd trimesters, and pre-eclamptic placental tissue supernatants (3rd trimester stimulated angiogenic and cytokine receptors expression by the cultured endothelial cells, as compared with their background expression. Tissue supernatants from placental samples of 3rd trimester caused a decreased expression of angiogenic and cytokine receptors by endothelial cells, thus reflecting maturation of placental vascular system at these terms. Supernatants from preeclamptic placental tissue induced an increase of CD119 expression, in comparison with normal placental supernatants from the 3rd trimester. This finding suggests that IFNγ may be a factor of endothelial activation in pre-eclampsia. The study was supported by grants ГК №02.740.11.0711, НШ-3594.2010.7., and МД-150.2011.7.

  17. Co-ordinate regulation of growth factor receptors and lipid phosphate phosphatase-1 controls cell activation by exogenous lysophosphatidate.

    Science.gov (United States)

    Pilquil, C; Ling, Z C; Singh, I; Buri, K; Zhang, Q X; Brindley, D N

    2001-11-01

    The serum-derived lipid growth factors, lysophosphatidate (LPA) and sphingosine 1-phosphate (S1P), activate cells selectively through different members of a family of endothelial differentiation gene (EDG) receptors. Activation of EDG receptors by LPA and S1P provides a variety of signalling cascades depending upon the G-protein coupling of the different EDG receptors. This leads to chemotactic and mitogenic responses, which are important in wound healing. For example, LPA stimulates fibroblast division and S1P stimulates the chemotaxis and division of endothelial cells leading to angiogenesis. Counteracting these effects of LPA and S1P, are the actions of lipid phosphate phosphatases (LPP, or phosphatidate phosphohydrolases, Type 2). The isoform LPP-1 is expressed in the plasma membrane with its active site outside the cell. This enzyme is responsible for 'ecto-phosphatase' activity leading to the degradation of exogenous lipid phosphate mediators, particularly LPA. Expression of LPP-1 decreases cell activation by exogenous LPA. The mechanism for this is controversial and several mechanisms have been proposed. Evidence will be presented that the LPPs cross-talk with EDG and other growth factor receptors, thus, regulating the responses of the cells to lipid phosphate mediators of signal transduction.

  18. Transcription Factor KLF5 Binds a Cyclin E1 Polymorphic Intronic Enhancer to Confer Increased Bladder Cancer Risk

    Science.gov (United States)

    Pattison, Jillian M.; Posternak, Valeriya; Cole, Michael D.

    2016-01-01

    It is well established that environmental toxins, such as exposure to arsenic, are risk factors in the development of urinary bladder cancer, yet recent genome-wide association studies (GWAS) provide compelling evidence that there is a strong genetic component associated with disease predisposition. A single nucleotide polymorphism (SNP), rs8102137, was identified on chromosome 19q12, residing 6 kb upstream of the important cell cycle regulator and proto-oncogene, Cyclin E1 (CCNE1). However, the functional role of this variant in bladder cancer predisposition has been unclear since it lies within a non-coding region of the genome. Here, it is demonstrated that bladder cancer cells heterozygous for this SNP exhibit biased allelic expression of CCNE1 with 1.5-fold more transcription occurring from the risk allele. Furthermore, using chromatin immunoprecipitation assays, a novel enhancer element was identified within the first intron of CCNE1 that binds Kruppel-like Factor 5 (KLF5), a known transcriptional activator in bladder cancer. Moreover, the data reveal that the presence of rs200996365, a SNP in high linkage disequilibrium with rs8102137 residing in the center of a KLF5 motif, alters KLF5 binding to this genomic region. Through luciferase assays and CRISPR-Cas9 genome editing, a novel polymorphic intronic regulatory element controlling CCNE1 transcription is characterized. These studies uncover how a cancer-associated polymorphism mechanistically contributes to an increased predisposition for bladder cancer development. Implications A polymorphic KLF5 binding site near the CCNE1 gene explains genetic risk identified through genome wide association studies. PMID:27514407

  19. Keratin 17 is overexpressed and predicts poor survival in estrogen receptor-negative/human epidermal growth factor receptor-2-negative breast cancer.

    Science.gov (United States)

    Merkin, Ross D; Vanner, Elizabeth A; Romeiser, Jamie L; Shroyer, A Laurie W; Escobar-Hoyos, Luisa F; Li, Jinyu; Powers, Robert S; Burke, Stephanie; Shroyer, Kenneth R

    2017-04-01

    Clinicopathological features of breast cancer have limited accuracy to predict survival. By immunohistochemistry (IHC), keratin 17 (K17) expression has been correlated with triple-negative status (estrogen receptor [ER]/progesterone receptor/human epidermal growth factor receptor-2 [HER2] negative) and decreased survival, but K17 messenger RNA (mRNA) expression has not been evaluated in breast cancer. K17 is a potential prognostic cancer biomarker, targeting p27, and driving cell cycle progression. This study compared K17 protein and mRNA expression to ER/progesterone receptor/HER2 receptor status and event-free survival. K17 IHC was performed on 164 invasive breast cancers and K17 mRNA was evaluated in 1097 breast cancers. The mRNA status of other keratins (16/14/9) was evaluated in 113 ER - /HER2 - ductal carcinomas. IHC demonstrated intense cytoplasmic and membranous K17 localization in myoepithelial cells of benign ducts and lobules and tumor cells of ductal carcinoma in situ. In ductal carcinomas, K17 protein was detected in most triple-negative tumors (28/34, 82%), some non-triple-negative tumors (52/112, 46%), but never in lobular carcinomas (0/15). In ductal carcinomas, high K17 mRNA was associated with reduced 5-year event-free survival in advanced tumor stage (n = 149, hazard ratio [HR] = 3.68, P = .018), and large (n = 73, HR = 3.95, P = .047), triple-negative (n = 103, HR = 2.73, P = .073), and ER - /HER2 - (n = 113, HR = 2.99, P = .049) tumors. There were significant correlations among keratins 17, 16, 14, and 9 mRNA levels suggesting these keratins (all encoded on chromosome 17) could be coordinately expressed in breast cancer. Thus, K17 is expressed in a subset of triple-negative breast cancers, and is a marker of poor prognosis in patients with advanced stage and ER - /HER2 - breast cancer. Copyright © 2016 Elsevier Inc. All rights reserved.

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

    Science.gov (United States)

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

    2011-12-01

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

  1. Differential expression of growth factor receptors and membrane-bound tumor markers for imaging in male and female breast cancer.

    Directory of Open Access Journals (Sweden)

    Jeroen F Vermeulen

    Full Text Available INTRODUCTION: Male breast cancer accounts for 0.5-1% of all breast cancers and is generally diagnosed at higher stage than female breast cancers and therefore might benefit from earlier detection and targeted therapy. Except for HER2 and EGFR, little is known about expression of growth factor receptors in male breast cancer. We therefore investigated expression profiles of growth factor receptors and membrane-bound tumor markers in male breast cancer and gynecomastia, in comparison with female breast cancer. METHODS: Tissue microarrays containing 133 male breast cancer and 32 gynecomastia cases were stained by immunohistochemistry for a panel of membrane-bound targets and compared with data on 266 female breast cancers. RESULTS: Growth factor receptors were variably expressed in 4.5% (MET up to 38.5% (IGF1-R of male breast cancers. Compared to female breast cancer, IGF1-R and carbonic anhydrase 12 (CAXII were more frequently and CD44v6, MET and FGFR2 less frequently expressed in male breast cancer. Expression of EGFR, HER2, CAIX, and GLUT1 was not significantly different between male and female breast cancer. Further, 48.1% of male breast cancers expressed at least one and 18.0% expressed multiple growth factor receptors. Since individual membrane receptors are expressed in only half of male breast cancers, a panel of membrane markers will be required for molecular imaging strategies to reach sensitivity. A potential panel of markers for molecular imaging, consisting of EGFR, IGF1-R, FGFR2, CD44v6, CAXII, GLUT1, and CD44v6 was positive in 77% of male breast cancers, comparable to female breast cancers. CONCLUSIONS: Expression patterns of growth factor receptors and hypoxia membrane proteins in male breast cancer are different from female breast cancer. For molecular imaging strategies, a putative panel consisting of markers for EGFR, IGF1-R, FGFR2, GLUT1, CAXII, CD44v6 was positive in 77% of cases and might be considered for development of

  2. New factors influencing G protein coupled receptors’ system ...

    African Journals Online (AJOL)

    Abdelaziz Ghanemi

    2012-11-24

    Nov 24, 2012 ... including those related to structure/activity relationship (some aspects have ..... caveolae, whereas G(i) and G(s) target lipid rafts by default. Mol .... classification of receptors for 5-hydroxytryptamine (Serotonin). Pharmacol Rev ...

  3. The Estrogen Receptor and Its Variants as Risk Factors in Breast Cancer

    National Research Council Canada - National Science Library

    Murph, Leigh

    2001-01-01

    The overall goal of this research is to understand how the estrogen receptor (ER) signal transduction pathway is altered during breast tumorigenesis and if altered ER signal transduction increases the risk of developing breast cancer...

  4. Polyethylene Glycol Mediated Colorectal Cancer Chemoprevention: Roles of Epidermal Growth Factor Receptor and Snail

    Science.gov (United States)

    Wali, Ramesh K.; Kunte, Dhananjay P.; Koetsier, Jennifer L.; Bissonnette, Marc; Roy, Hemant K.

    2008-01-01

    Polyethylene glycol (PEG) is a clinically widely used agent with profound chemopreventive properties in experimental colon carcinogenesis. We previously reported that Snail/β-catenin signaling may mediate the suppression of epithelial proliferation by PEG, although the upstream events remain unclear. We report herein the role of epidermal growth factor receptor (EGFR), a known mediator of Snail and overepressed in ~80% of human colorectal cancers (CRC), on PEG-mediated anti-proliferative and hence anti-neoplastic effects in azoxymethane (AOM)-rats and HT-29 colon cancer cells. AOM-rats were randomized to either standard diet or one with 10% PEG 3350 and euthanized 8 weeks later. The colonic samples were subjected to immunohistochemical or Western blot analyses. PEG decreased mucosal EGFR by 60% (pPEG effects were obtained in HT-29 cells. PEG suppressed EGFR protein via lysosmal degradation with no change in mRNA levels. To show that EGFR antagonism per se was responsible for the antiproliferative effect, we inhibited EGFR by either pre-treating cells with gefitinib or stably transfecting with EGFR-shRNA and measured the effect of PEG on proliferation. In either case PEG effect was blunted suggesting a vital role of EGFR. Flow cytometric analysis revealed that EGFR-shRNA cells, besides having reduced membrane EGFR also expressed low Snail levels (40%), corroborating a strong association. Furthermore, in EGFR silenced cells PEG effect on EGFR or Snail was muted, similar to that on proliferation. In conclusion, we show that EGFR is the proximate membrane signaling molecule through which PEG initiates antiproliferative activity with Snail/β-catenin pathway playing the central intermediary function. PMID:18790788

  5. Polyethylene glycol-mediated colorectal cancer chemoprevention: roles of epidermal growth factor receptor and Snail.

    Science.gov (United States)

    Wali, Ramesh K; Kunte, Dhananjay P; Koetsier, Jennifer L; Bissonnette, Marc; Roy, Hemant K

    2008-09-01

    Polyethylene glycol (PEG) is a clinically widely used agent with profound chemopreventive properties in experimental colon carcinogenesis. We reported previously that Snail/beta-catenin signaling may mediate the suppression of epithelial proliferation by PEG, although the upstream events remain unclear. We report herein the role of epidermal growth factor receptor (EGFR), a known mediator of Snail and overexpressed in approximately 80% of human colorectal cancers, on PEG-mediated antiproliferative and hence antineoplastic effects in azoxymethane (AOM) rats and HT-29 colon cancer cells. AOM rats were randomized to either standard diet or one with 10% PEG-3350 and euthanized 8 weeks later. The colonic samples were subjected to immunohistochemical or Western blot analyses. PEG decreased mucosal EGFR by 60% (P PEG effects were obtained in HT-29 cells. PEG suppressed EGFR protein via lysosmal degradation with no change in mRNA levels. To show that EGFR antagonism per se was responsible for the antiproliferative effect, we inhibited EGFR by either pretreating cells with gefitinib or stably transfecting with EGFR-short hairpin RNA and measured the effect of PEG on proliferation. In either case, PEG effect was blunted, suggesting a vital role of EGFR. Flow cytometric analysis revealed that EGFR-short hairpin RNA cells, besides having reduced membrane EGFR, also expressed low Snail levels (40%), corroborating a strong association. Furthermore, in EGFR silenced cells, PEG effect on EGFR or Snail was muted, similar to that on proliferation. In conclusion, we show that EGFR is the proximate membrane signaling molecule through which PEG initiates antiproliferative activity with Snail/beta-catenin pathway playing the central intermediary function.

  6. Divergent epidermal growth factor receptor mutation patterns between smokers and non-smokers with lung adenocarcinoma.

    Science.gov (United States)

    Tseng, Jeng-Sen; Wang, Chih-Liang; Yang, Tsung-Ying; Chen, Chih-Yi; Yang, Cheng-Ta; Chen, Kun-Chieh; Hsu, Kuo-Hsuan; Tsai, Chi-Ren; Chang, Gee-Chen

    2015-12-01

    Smoking status is an important determinant of the prevalence of epidermal growth factor receptor (EGFR) mutations in lung cancer patients. However, it is unclear whether smoking status could also influence the spectrum of EGFR mutations. We enrolled patients with lung adenocarcinoma from three medical centers in Taiwan. EGFR mutations were assessed by Sanger direct sequencing. The objective of this study was to evaluate the influence of smoking status on both the frequency and patterns of EGFR mutations. From 2001 to 2013, a total of 1175 patients with lung adenocarcinoma were enrolled for EGFR mutation analysis. The overall EGFR mutation rate was 59.6%, which was significantly higher in females than males (69.1% vs. 49.8%) and in non-smokers than current/former smokers (73.8% vs. 29.8%) (both Psmokers expressed L858R mutation less frequently (35.2% vs. 50.2%, P=0.005) and exon 19 deletions more frequently (52.8% vs 38.8%, P=0.008) than non-smokers. Smokers and non-smokers also had divergent exon 19 deletions subtypes (Del E746-A750 82.5% vs. 57.6%, respectively, Psmokers were associated with a higher rate of complex mutations than non-smokers (34.2% vs. 8.4%, P<0.001). Our results suggested that smoking status could influence not only the frequency but also the spectrum of EGFR mutations. These findings provide a clue for further investigation of EGFR mutagenesis. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  7. Radiolabeled pertuzumab for imaging of human epidermal growth factor receptor 2 expression in ovarian cancer

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Dawei [Shenzhen University, Guangdong Key Laboratory for Biomedical Measurements and Ultrasound Imaging, School of Biomedical Engineering, Shenzhen (China); University of Wisconsin - Madison, Department of Radiology, Madison, WI (United States); Im, Hyung-Jun [University of Wisconsin - Madison, Department of Radiology, Madison, WI (United States); Seoul National University, Graduate School of Convergence Science and Technology, Seoul (Korea, Republic of); Sun, Haiyan; Cho, Steve Y. [University of Wisconsin - Madison, Department of Radiology, Madison, WI (United States); Valdovinos, Hector F.; England, Christopher G.; Ehlerding, Emily B.; Nickles, Robert J. [University of Wisconsin - Madison, Department of Medical Physics, Madison, WI (United States); Lee, Dong Soo [Seoul National University, Graduate School of Convergence Science and Technology, Seoul (Korea, Republic of); Huang, Peng [Shenzhen University, Guangdong Key Laboratory for Biomedical Measurements and Ultrasound Imaging, School of Biomedical Engineering, Shenzhen (China); Cai, Weibo [University of Wisconsin - Madison, Department of Radiology, Madison, WI (United States); University of Wisconsin - Madison, Department of Medical Physics, Madison, WI (United States); University of Wisconsin Carbone Cancer Center, Madison, WI (United States)

    2017-08-15

    Human epidermal growth factor receptor 2 (HER2) is over-expressed in over 30% of ovarian cancer cases, playing an essential role in tumorigenesis and metastasis. Non-invasive imaging of HER2 is of great interest for physicians as a mean to better detect and monitor the progression of ovarian cancer. In this study, HER2 was assessed as a biomarker for ovarian cancer imaging using {sup 64}Cu-labeled pertuzumab for immu