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Sample records for cell factor receptor

  1. Soluble and cell surface receptors for tumor necrosis factor

    DEFF Research Database (Denmark)

    Wallach, D; Engelmann, H; Nophar, Y;

    1991-01-01

    Tumor necrosis factor (TNF) initiates its multiple effects on cell function by binding at a high affinity to specific cell surface receptors. Two different molecular species of these receptors, which are expressed differentially in different cells, have been identified. The cDNAs of both receptors...... certain pathological situations. Release of the soluble receptors from the cells seems to occur by proteolytic cleavage of the cell surface forms and appears to be a way of down-regulating the cell response to TNF. Because of their ability to bind TNF, the soluble receptors exert an inhibitory effect on...

  2. Epidermal growth factor receptor expression in canine transitional cell carcinoma

    OpenAIRE

    HANAZONO, Kiwamu; Fukumoto, Shinya; KAWAMURA, Yoshio; ENDO, Yoshifumi; Kadosawa, Tsuyoshi; IWANO, Hidetomo; UCHIDE, Tsuyoshi

    2014-01-01

    Transitional cell carcinoma (TCC), a urinary bladder tumor with high mortality, is encountered commonly in dogs. Whereas overexpression of epidermal growth factor receptor (EGFR) is associated with development of human urinary bladder cancer, information on EGFR expression in canine TCC is lacking. In this study, EGFR protein and mRNA expression in canine normal bladder (n=5), polypoid cystitis (n=5) and TCC (n=25) were examined by immunohistochemistry and real-time polymerase chain reaction....

  3. Tumor necrosis factor receptor superfamily costimulation couples T cell receptor signal strength to thymic regulatory T cell differentiation

    OpenAIRE

    Mahmud, Shawn A.; Manlove, Luke S.; Schmitz, Heather M.; Xing, Yan; Wang, Yanyan; Owen, David L.; Schenkel, Jason M.; Boomer, Jonathan S; Jonathan M Green; Yagita, Hideo; Chi, Hongbo; Hogquist, Kristin A.; Farrar, Michael A.

    2014-01-01

    Regulatory T (Treg) cells express tumor necrosis factor receptor superfamily (TNFRSF) members, but their role in thymic Treg development is undefined. We demonstrate that Treg progenitors highly express the TNFRSF members GITR, OX40, and TNFR2. Expression of these receptors correlates directly with T cell receptor (TCR) signal strength, and requires CD28 and the kinase TAK1. Neutralizing TNFSF ligands markedly reduced Treg development. Conversely, TNFRSF agonists enhanced Treg differentiation...

  4. Cheiradone: a vascular endothelial cell growth factor receptor antagonist

    Directory of Open Access Journals (Sweden)

    Ahmed Nessar

    2008-01-01

    Full Text Available Abstract Background Angiogenesis, the growth of new blood vessels from the pre-existing vasculature is associated with physiological (for example wound healing and pathological conditions (tumour development. Vascular endothelial growth factor (VEGF, fibroblast growth factor-2 (FGF-2 and epidermal growth factor (EGF are the major angiogenic regulators. We have identified a natural product (cheiradone isolated from a Euphorbia species which inhibited in vivo and in vitro VEGF- stimulated angiogenesis but had no effect on FGF-2 or EGF activity. Two primary cultures, bovine aortic and human dermal endothelial cells were used in in vitro (proliferation, wound healing, invasion in Matrigel and tube formation and in vivo (the chick chorioallantoic membrane models of angiogenesis in the presence of growth factors and cheiradone. In all cases, the concentration of cheiradone which caused 50% inhibition (IC50 was determined. The effect of cheiradone on the binding of growth factors to their receptors was also investigated. Results Cheiradone inhibited all stages of VEGF-induced angiogenesis with IC50 values in the range 5.20–7.50 μM but did not inhibit FGF-2 or EGF-induced angiogenesis. It also inhibited VEGF binding to VEGF receptor-1 and 2 with IC50 values of 2.9 and 0.61 μM respectively. Conclusion Cheiradone inhibited VEGF-induced angiogenesis by binding to VEGF receptors -1 and -2 and may be a useful investigative tool to study the specific contribution of VEGF to angiogenesis and may have therapeutic potential.

  5. 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; Poulsen, H S

    1992-01-01

    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...... lung cancer cell lines express the EGF receptor....... 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 of...

  6. Altered expression of epidermal growth factor receptor and estrogen receptor in MCF-7 cells after single and repeated radiation exposures

    International Nuclear Information System (INIS)

    This study focuses on the characterization of expression modulation of two critical growth regulatory genes, estrogen receptor and epidermal growth factor-receptor, in malignant mammary epithelial cells in response to single and repeated ionizing radiation exposures. MCF-7 cells were used for single radiation exposure (2-50 Gy) experiments and MCF-IR-3 cells, generated by exposure to cumulative doses of 60 Gy in 2 Gy fractions, respectively, were used to study the effects of repeated exposures. Steady-state messenger ribonucleic acid levels for estrogen receptor, epidermal growth factor-receptor, and transforming growth factor-α were determined by ribonucleic acid protection experiments. Estrogen receptor and epidermal growth factor-receptor protein expression was quantitated by competitive binding studies with 3H-estradiol and 125I-EGF. MCF-IR-3 cells showed a permanent three-fold down-regulation of the estrogen receptor messenger ribonucleic acid and protein, while epidermal growth factor-receptor was upregulated about nine-fold. Epidermal growth factor-receptor was substantially up-regulated in MCF-7 cells, at both the mRNA and protein levels, within 24 h of a single 2 Gy exposures, while there was a two-fold concomitant increase in transforming growth factor-α messenger ribonucleic acid expression. A decrease in estrogen receptor messenger ribonucleic acid and protein was suggested only after higher doses of single radiation exposures. The inverse expression of estrogen receptor and epidermal growth factor-receptor established for estrogen receptor-positive malignant mammary epithelial cells is maintained in MCF-7 cells after single and repeated exposures, suggesting that radiation acts through common regulatory circuits and may modulate the cellular phenotype. 40 refs., 2 figs., 2 tabs

  7. Expression of epidermal growth factor receptor is an independent prognostic factor for esophageal squamous cell carcinoma

    OpenAIRE

    Wang, Qifeng; Zhu, Hongxia; Xiao, Zefen; Zhang, Wencheng; Liu, Xiao; Zhang, Xun; He, Jie; Kelin SUN; Wang, Lvhua; Xu, Ningzhi

    2013-01-01

    Background The overall survival of patients with esophageal squamous cell carcinoma (ESCC) remains poor. Prognostic predictions in ESCC are usually based on histological assessment of tumor invasion and lymph node metastasis, but a biomarker with better predictive accuracy could be more useful. Because overexpression of epidermal growth factor receptor (EGFR) has been associated with poor prognosis, this study investigated whether EGFR is an independent prognostic factor for overall survival ...

  8. Phosphorylation of insulin-like growth factor I receptor by insulin receptor tyrosine kinase in intact cultured skeletal muscle cells

    International Nuclear Information System (INIS)

    The interaction between insulin and insulin-like growth factor I (IGF I) receptors was examined by determining the ability of each receptor type to phosphorylate tyrosine residues on the other receptor in intact L6 skeletal muscle cells. This was made possible through a sequential immunoprecipitation method with two different antibodies that effectively separated the phosphorylated insulin and IGF I receptors. After incubation of intact L6 cells with various concentrations of insulin or IGF I in the presence of [32P]-orthophosphate, insulin receptors were precipitated with one of two human polyclonal anti-insulin receptor antibodies (B2 or B9). Phosphorylated IGF I receptors remained in solution and were subsequently precipitated by anti-phosphotyrosine antibodies. The identifies of the insulin and IGF I receptor β-subunits in the two immunoprecipitates were confirmed by binding affinity, by phosphopeptide mapping after trypsin digestion, and by the distinct patterns of expression of the two receptors during differentiation. Stimulated phosphorylation of the β-subunit of the insulin receptor correlated with the occupancy of the β-subunit of the insulin receptor by either insulin or IGF I as determined by affinity cross-linking. Similarly, stimulation of phosphorylation of the β-subunit of the IGF I receptor by IGF I correlated with IGF I receptor occupancy. In contrast, insulin stimulated phosphorylation of the β-subunit of the IGF I receptor at hormone concentrations that were associated with significant occupancy of the insulin receptor but negligible IGF I receptor occupancy. These findings indicate that the IGF I receptor can be a substrate for the hormone-activated insulin receptor tyrosine kinase activity in intact L6 skeletal muscle cells

  9. Phosphorylation of insulin-like growth factor I receptor by insulin receptor tyrosine kinase in intact cultured skeletal muscle cells

    Energy Technology Data Exchange (ETDEWEB)

    Beguinot, F.; Smith, R.J.; Kahn, C.R.; Maron, R.; Moses, A.C.; White, M.F.

    1988-05-03

    The interaction between insulin and insulin-like growth factor I (IGF I) receptors was examined by determining the ability of each receptor type to phosphorylate tyrosine residues on the other receptor in intact L6 skeletal muscle cells. This was made possible through a sequential immunoprecipitation method with two different antibodies that effectively separated the phosphorylated insulin and IGF I receptors. After incubation of intact L6 cells with various concentrations of insulin or IGF I in the presence of (/sup 32/P)-orthophosphate, insulin receptors were precipitated with one of two human polyclonal anti-insulin receptor antibodies (B2 or B9). Phosphorylated IGF I receptors remained in solution and were subsequently precipitated by anti-phosphotyrosine antibodies. The identifies of the insulin and IGF I receptor ..beta..-subunits in the two immunoprecipitates were confirmed by binding affinity, by phosphopeptide mapping after trypsin digestion, and by the distinct patterns of expression of the two receptors during differentiation. Stimulated phosphorylation of the ..beta..-subunit of the insulin receptor correlated with the occupancy of the ..beta..-subunit of the insulin receptor by either insulin or IGF I as determined by affinity cross-linking. Similarly, stimulation of phosphorylation of the ..beta..-subunit of the IGF I receptor by IGF I correlated with IGF I receptor occupancy. In contrast, insulin stimulated phosphorylation of the ..beta..-subunit of the IGF I receptor at hormone concentrations that were associated with significant occupancy of the insulin receptor but negligible IGF I receptor occupancy. These findings indicate that the IGF I receptor can be a substrate for the hormone-activated insulin receptor tyrosine kinase activity in intact L6 skeletal muscle cells.

  10. Neural cell adhesion molecule differentially interacts with isoforms of the fibroblast growth factor receptor

    DEFF Research Database (Denmark)

    Christensen, Claus; Berezin, Vladimir; Bock, Elisabeth

    2011-01-01

    The fibroblast growth factor receptor (FGFR) can be activated through direct interactions with various fibroblast growth factors or through a number of cell adhesion molecules, including the neural cell adhesion molecule (NCAM). We produced recombinant proteins comprising the ligand...... the expression pattern of various FGFR isoforms determines the cell context-specific effects of NCAM signaling through FGFR....

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

    International Nuclear Information System (INIS)

    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

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

    International Nuclear Information System (INIS)

    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 [125I]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

  13. Proteomic and phosphoproteomic analysis of signalling by adhesion and growth factor receptors in mammary epithelial cells

    OpenAIRE

    Paul, Nikki

    2014-01-01

    Cell adhesion and communication are essential for tissue morphogenesis and repair in healthy multicellular organisms. However, dysregulation of these processes can drive disease progression in conditions such as cancer. Selective cell adhesion to the extracellular matrix is mediated by integrins, a family of transmembrane receptors that compartmentalise signalling and organise the cytoskeleton. Adhesion receptors provide spatial cues to cells to allow them to respond to growth factor and cyto...

  14. Tumor Necrosis Factor Receptor 2: Its Contribution to Acute Cellular Rejection and Clear Cell Renal Carcinoma

    OpenAIRE

    Jun Wang; Al-Lamki, Rafia S.

    2013-01-01

    Tumor necrosis factor receptor 2 (TNFR2) is a type I transmembrane glycoprotein and one of the two receptors that orchestrate the complex biological functions of tumor necrosis factor (TNF, also designed TNF- α ). Accumulating experimental evidence suggests that TNFR2 plays an important role in renal disorders associated with acute cellular rejection and clear cell renal carcinoma but its exact role in these settings is still not completely understood. This papers reviews the factors that may...

  15. A dual immunocytochemical assay for oestrogen and epidermal growth factor receptors in tumour cell lines

    NARCIS (Netherlands)

    A.K. Sharma (Anisha K.); J.H. Horgan; R.L. McClelland (Robyn); A.G. Douglas-Jones (A.); T. van Agthoven (Ton); L.C.J. Dorssers (Lambert); R.I. Nicholson (R.)

    1994-01-01

    textabstractA new dual immunocytochemical assay for oestrogen receptor (ER) and epidermal growth factor receptor (EGFR) has been developed. It has been tested in a variety of conditions using cell culture lines and the results correlate well with those obtained from single immunocytochemical assays.

  16. The Na+/H+ Exchanger Regulatory Factor Stabilizes Epidermal Growth Factor Receptors at the Cell Surface

    OpenAIRE

    Lazar, Cheri S.; Cresson, Catherine M.; Lauffenburger, Douglas A.; Gill, Gordon N.

    2004-01-01

    Ligand binding to cell surface receptors initiates both signal transduction and endocytosis. Although signaling may continue within the endocytic compartment, down-regulation is the major mechanism that controls the concentration of cell surface receptors, their ability to receive environmental signals, and the ultimate strength of biological signaling. Internalization, recycling, and trafficking of receptor tyrosine kinases (RTKs) within the endosome compartment are each regulated to control...

  17. Amphiregulin enhances regulatory T cell suppressive function via the epidermal growth factor receptor

    OpenAIRE

    Zaiss, Dietmar M.W.; van Loosdregt, Jorg; Gorlani, Andrea; Bekker, Cornelis P.J.; Gröne, Andrea; Sibilia, Maria; van Bergen en Henegouwen, Paul M. P.; Roovers, Rob C.; Coffer, Paul J.; Sijts, Alice J.A.M.

    2013-01-01

    Epidermal growth factor receptor (EGFR) is known to be critically involved in tissue development and homeostasis as well as in the pathogenesis of cancer. Here we showed that Foxp3+ regulatory T (Treg) cells express EGFR under inflammatory conditions. Stimulation with the EGF-like growth factor Amphiregulin (AREG) markedly enhanced Treg cell function in vitro, and in a colitis and tumor vaccination model we showed that AREG was critical for efficient Treg cell function in vivo. In addition, m...

  18. Asymmetric Receptor Contact is Required for Tyrosine Autophosphorylation of Fibroblast Growth Factor Receptor in Living Cells

    Energy Technology Data Exchange (ETDEWEB)

    Bae, J.; Boggon, T; Tomé, F; Mandiyan, V; Lax, I; Schlessinge, J

    2010-01-01

    Tyrosine autophosphorylation of receptor tyrosine kinases plays a critical role in regulation of kinase activity and in recruitment and activation of intracellular signaling pathways. Autophosphorylation is mediated by a sequential and precisely ordered intermolecular (trans) reaction. In this report we present structural and biochemical experiments demonstrating that formation of an asymmetric dimer between activated FGFR1 kinase domains is required for transphosphorylation of FGFR1 in FGF-stimulated cells. Transphosphorylation is mediated by specific asymmetric contacts between the N-lobe of one kinase molecule, which serves as an active enzyme, and specific docking sites on the C-lobe of a second kinase molecule, which serves a substrate. Pathological loss-of-function mutations or oncogenic activating mutations in this interface may hinder or facilitate asymmetric dimer formation and transphosphorylation, respectively. The experiments presented in this report provide the molecular basis underlying the control of transphosphorylation of FGF receptors and other receptor tyrosine kinases.

  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)

    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 [35S] 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. Antisense epidermal growth factor receptor RNA transfection in human glioblastoma cells down-regulates telomerase activity and telomere length

    OpenAIRE

    Tian, X-X; Pang, JC-S; J. Zheng; Chen, J; To, S S T; Ng, H-K

    2002-01-01

    Epidermal growth factor receptor is overexpressed and/or amplified in up to 50% of glioblastomas, suggesting an important role of this gene in glial tumorigenesis and progression. In the present study we demonstrated that epidermal growth factor receptor is involved in regulation of telomerase activity in glioblastoma. Antisense-epidermal growth factor receptor approach was used to inhibit epidermal growth factor receptor expression of glioblastoma U87MG cells. Telomerase activity in antisens...

  1. 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.

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

    International Nuclear Information System (INIS)

    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 × 106 cells mL−1 with a detection limit of 40 cells mL−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 × 105 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

  3. Epidermal growth factor receptor subunit locations determined in hydrated cells with environmental scanning electron microscopy

    OpenAIRE

    Peckys, Diana B.; Jean-Pierre Baudoin; Magdalena Eder; Ulf Werner; Niels de Jonge

    2013-01-01

    Imaging single epidermal growth factor receptors (EGFR) in intact cells is presently limited by the available microscopy methods. Environmental scanning electron microscopy (ESEM) of whole cells in hydrated state in combination with specific labeling with gold nanoparticles was used to localize activated EGFRs in the plasma membranes of COS7 and A549 cells. The use of a scanning transmission electron microscopy (STEM) detector yielded a spatial resolution of 3 nm, sufficient to identify the l...

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

    DEFF Research Database (Denmark)

    Christensen, Claus; Lauridsen, Jes B; Berezin, Vladimir; Bock, Elisabeth; Kiselyov, Vladislav V

    2006-01-01

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

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

    DEFF Research Database (Denmark)

    Harper, Peter; El-Hariry, Iman; Powles, Thomas; Lau, Mike R; Sternberg, Cora N; Ravaud, Alain; von der Maase, Hans; Zantl, Niko; Harper, Peter Mathias; Rolland, Frédéric; Audhuy, Bruno; Barthel, Friederike; Machiels, Jean-Pascal; Patel, Pina; Kreuser, Ernst-Dietrick; Hawkins, Robert E

    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...

  6. Kit receptor dimerization is driven by bivalent binding of stem cell factor.

    Science.gov (United States)

    Lemmon, M A; Pinchasi, D; Zhou, M; Lax, I; Schlessinger, J

    1997-03-01

    Most growth factors and cytokines activate their receptors by inducing dimerization upon binding. We have studied binding of the dimeric cytokine stem cell factor (SCF) to the extracellular domain of its receptor Kit, which is a receptor tyrosine kinase similar to the receptors for platelet-derived growth factor and colony-stimulating factor-1. Calorimetric studies show that one SCF dimer binds simultaneously to two molecules of the Kit extracellular domain. Gel filtration and other methods show that this results in Kit dimerization. It has been proposed that SCF-induced Kit dimerization proceeds via a conformational change that exposes a key receptor dimerization site in the fourth of the five immunoglobulin (Ig)-like domains in Kit. We show that a form of Kit containing just the first three Ig domains (Kit-123) binds to SCF with precisely the same thermodynamic parameters as does Kit-12345. Analytical ultracentrifugation, light scattering, and gel filtration show that Kit-123 dimerizes upon SCF binding in a manner indistinguishable from that seen with Kit-12345. These data argue that the fourth Ig-like domain of Kit is not required for SCF-induced receptor dimerization and provide additional support for a model in which bivalent binding of the SCF dimer provides the driving force for Kit dimerization. PMID:9045650

  7. Receptors for B cell stimulatory factor 2. Quantitation, specificity, distribution, and regulation of their expression

    Energy Technology Data Exchange (ETDEWEB)

    Taga, T.; Kawanishi, Y.; Hardy, R.R.; Hirano, T.; Kishimoto, T.

    1987-10-01

    B cell stimulatory factor 2 receptors (BSF-2-R) were studied using radioiodinated recombinant BSF-2 with a specific activity of 6.16 X 10(13) cpm/g. Kinetic studies showed that binding of /sup 125/I-BSF-2 to CESS cells reached maximum level within 150 min at 0 degrees C. There was a single class of receptors with high affinity (Kd 3.4 X 10(-10) M) on CESS, and the number of receptors was 2700 per cell. Binding of /sup 125/I-BSF-2 to CESS was competitively inhibited by unlabeled BSF-2 but not by IL-1, IL-2, IFN-beta, IFN-gamma, and G-CSF, indicating the presence of the receptors specific for BSF-2. EBV-transformed B lymphoblastoid cell lines (CESS, SKW6-CL4, LCL13, and LCL14) expressed BSF-2-R, whereas Burkitt's lines did not. EBV or EBNA2 did not induce the expression of the receptors on Burkitt's cells. The plasma cell lines (ARH-77 and U266) expressed BSF-2-R, fitting the function of BSF-2 as plasma cell growth factor. Several other cell lines, the histiocytic line U937, the promyelocytic line HL60, the astrocytoma line U373 and the glioblastoma line SK-MG-4, in which BSF-2 was inducible with IL-1 or TPA, displayed BSF-2-R with Kd in the range of 1.3-6.4 X 10(-10) M, suggesting the autocrine mechanism in BSF-2 function. The four T cell lines (CEM, HSB, Jurkat, and OM 1) did not express a detectable number of receptors, but normal resting T cells expressed 100-1000 receptors per cell. BSF-2-R were not present on normal resting B cells but expressed on activated B cells with a Kd of 3.6-5.0 X 10(-10) M, fitting the function of BSF-2, which acts on B cells at the final maturation stage to induce immunoglobulin production.

  8. Proliferative responses and binding properties of hematopoietic cells transfected with low-affinity receptors for leukemia inhibitory factor, oncostatin M, and ciliary neurotrophic factor.

    OpenAIRE

    Gearing, D P; Ziegler, S F; Comeau, M R; Friend, D; Thoma, B; Cosman, D; Park, L.; Mosley, B

    1994-01-01

    Specific low-affinity receptors for leukemia inhibitory factor (LIF), oncostatin M (OSM; gp130), and ciliary neurotrophic factor (CNTF; receptor alpha, CNTFR alpha) may be utilized in various combinations to generate high-affinity binding sites and signal transduction. We have tested the ability of combinations of these receptors to transduce a proliferative signal in BAF-B03 cells. Coexpression of the LIF receptor and gp130 in these cells conferred high-affinity LIF and OSM binding and respo...

  9. Structure of the active core of human stem cell factor and analysis of binding to its receptor Kit

    OpenAIRE

    Jiang, Xuliang; Gurel, Ogan; Mendiaz, Elizabeth A.; Stearns, George W.; Clogston, Christi L.; Lu, Hsieng S; Osslund, Timothy D.; Syed, Rashid S.; Langley, Keith E.; Hendrickson, Wayne A

    2000-01-01

    Stem cell factor (SCF) is an early-acting hematopoietic cytokine that elicits multiple biological effects. SCF is dimeric and occurs in soluble and membrane-bound forms. It transduces signals by ligand- mediated dimerization of its receptor, Kit, which is a receptor tyrosine kinase related to the receptors for platelet-derived growth factor (PDGF), macrophage colony-stimulating factor, Flt-3 ligand and vascular endothelial growth factor (VEGF). All of these have extracellular ligand-binding p...

  10. Gastrin-Releasing Peptide Receptor Mediates Activation of the Epidermal Growth Factor Receptor in Lung Cancer Cells

    Directory of Open Access Journals (Sweden)

    Sufi Mary Thomas

    2005-04-01

    Full Text Available Gastrin-releasing peptide receptor (GRPR and the epidermal growth factor receptor (EGFR are expressed in several cancers including non-small cell lung carcinoma (NSCLC. Here we demonstrate the activation of EGFR by the GRPR ligand, gastrin-releasing peptide (GRP, in NSCLC cells. GRP induced rapid activation of p44/42 MAPK in lung cancer cells through EGFR. GRP-mediated activation of MAPK in NSCLC cells was abrogated by pretreatment with the anti-EGFR-neutralizing antibody, C225. Pretreatment of NSCLC cells with neutralizing antibodies to the EGFR ligands, TGF-α or HB-EGF, also decreased GRP-mediated MAPK activation. On matrix metalloproteinase (MMP inhibition, GRP failed to activate MAPK in NSCLC cells. EGF and GRP both stimulated NSCLC proliferation, and inhibition of either EGFR or GRPR resulted in cell death. Combining a GRPR antagonist with the EGFR tyrosine kinase inhibitor, gefitinib, resulted in additive cytotoxic effects. Additive effects were seen at gefitinib concentrations from 1 to 18μM, encompassing the ID50 values of both gefitinib-sensitive and gefitinib-resistant NSCLC cell lines. Because a major effect of GRPR appears to be promoting the release of EGFR ligand, this study suggests that a greater inhibition of cell proliferation may occur by abrogating EGFR ligand release in consort with inhibition of EGFR.

  11. Autoradiographic localization of epidermal growth factor receptors to all major uterine cell types

    International Nuclear Information System (INIS)

    We have recently studied the structure and function of the uterine epidermal growth factor (EGF) receptor, its hormonal regulation, and its possible role in estrogen-induced uterine DNA synthesis. Since the uterus is composed of multiple cell types, we sought, in the work reported here, to localize EGF binding in this organ by autoradiography. Prior to the actual autoradiography, we performed a companion series of experiments to insure that EGF binding to uterine tissue in situ represented a true receptor interaction. Uteri from immature female rats were incubated in vitro with 125I-EGF at 25 degrees C. Tissue binding was maximal within 120 min and remained constant for at least an additional 120 min. This binding of labeled EGF was largely abolished by excess unlabeled EGF but not by other growth factors, indicating that binding was to specific receptors. The binding of 125I-EGF was saturable and reached a plateau at 4-8 nM; specific binding was half-maximal at 1-2 nM EGF. In situ cross-linking studies revealed that 125I-EGF was bound predominantly to a 170,000 MW EGF receptor similar to that seen in isolated uterine membranes. Incubation of uteri with 125I-EGF followed by autoradiography revealed binding to epithelial cells, stroma, and myometrium. These results provide evidence for the presence of specific EGF receptors in all major uterine cell types of the immature rat

  12. Amphiregulin enhances regulatory T cell-suppressive function via the epidermal growth factor receptor.

    Science.gov (United States)

    Zaiss, Dietmar M W; van Loosdregt, Jorg; Gorlani, Andrea; Bekker, Cornelis P J; Gröne, Andrea; Sibilia, Maria; van Bergen en Henegouwen, Paul M P; Roovers, Rob C; Coffer, Paul J; Sijts, Alice J A M

    2013-02-21

    Epidermal growth factor receptor (EGFR) is known to be critically involved in tissue development and homeostasis as well as in the pathogenesis of cancer. Here we showed that Foxp3(+) regulatory T (Treg) cells express EGFR under inflammatory conditions. Stimulation with the EGF-like growth factor Amphiregulin (AREG) markedly enhanced Treg cell function in vitro, and in a colitis and tumor vaccination model we showed that AREG was critical for efficient Treg cell function in vivo. In addition, mast cell-derived AREG fully restored optimal Treg cell function. These findings reveal EGFR as a component in the regulation of local immune responses and establish a link between mast cells and Treg cells. Targeting of this immune regulatory mechanism may contribute to the therapeutic successes of EGFR-targeting treatments in cancer patients. PMID:23333074

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

    International Nuclear Information System (INIS)

    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

  14. EXPRESSION OF EPIDERMAL GROWTH FACTOR RECEPTOR IN DIFFERENT SALIVARY ADENOID CYSTIC CARCINOMA CELL LINES

    Institute of Scientific and Technical Information of China (English)

    MA Jie; ZONG Zhi-hong; WANG Zhao-yuan

    2005-01-01

    Objective: To investigate the expression of epidermal growth factor receptor, a receptor tyrosine protein kinase, in the subcellular fractions of human salivary adenoid cystic carcinoma cell lines SACC-83 and SACC-LM. Methods: Low metastatic and high metastatic cells of the adenoid cystic carcinoma, SACC-83 and SACC-LM, were cultured. Their subcellular fractions were extracted. The expression of epidermal growth factor receptor was detected with Western blot method, and the results of protein expression were quantitatively analyzed by FluorChem V2.0 software. Results: The results of Western blot analysis indicated that, EGFR expression on the membrane of SACC-83 cells was significantly higher than that of SACC-LM cells, but its expression in cytoplasm was significantly less in the former than the later (P<0.01). In SACC-83 cell line, EGFR was over-expressed in membrane (P<0.01), but in SACC-LM cell line, EGFR was over-expressed in cytoplasm (P<0.01). Conclusion: The results suggest that the obtaining of metastasis ability is related to the high expression of EGFR protein in cytoplasm, so the molecular targeting therapy to EGFR may be an ideal treatment for the invasion and metastasis of salivary adenoid cystic carcinoma.

  15. 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.

  16. Correlation between Grade in Transitional Cell Carcinoma (TCC and Expression of Epidermal Growth Factor Receptor (EGFR

    Directory of Open Access Journals (Sweden)

    MR Jallali Nadoushan

    2007-08-01

    Full Text Available Background: The present study was undertaken to investigate the correlation of Epidermal Growth Factor Receptor (EGFR expression with grade of Transitional Cell Carcinoma (TCC. Methods: Tumor samples of 75 patients from Mostafa Khomaini Hospital with Transitional Cell Carcinoma of the bladder were analyzed by immunohistochemistry for expression of EGFR. In this context, we assigned the bladder tumors a grade accord¬ing WHO classification. Results analyzed for possible correlation with the expression status of the Epidermal Growth Factor Receptor (EGFR. Results: This cross-sectional study showed that all grades of Transitional Cell Carcinoma expressed EGFR, and 14 cases were LMP (18.9% which 10 cases among them had negative cells according EGFR point of view(71.4% and 4 cases had re¬ported positive (28.6%. Thirty five cases were low grade (46.7% which 18 cases among them had reported negative cells (51.4% and 17 cases had positive cells (48.6%. Twenty six cases were high grade (34.7% that 9 cases among them had reported negative cells (34.6%. Seventeen cases had positive cells (65.4%. Mann-Witney test showed relation between grade and expression of EGFR (P<0.05. Conclusions: This study showed that expression of EGFR is correlated with grade of tumor.

  17. Insulin-like growth factor-1 receptor expression in oral squamous cell carcinoma

    OpenAIRE

    Joseph, Boby K.; Sundaram, Devipriyaa B.

    2011-01-01

    Objectives: The Insulin-like growth factor-I receptor (IGF-1R) plays critical roles in cancer development, proliferation, motility and survival. IGF-1R over expression is frequently found in various tumours and is often associated with an aggressive phenotype. Hence, the aim of the present study was to examine the expression of IGF-1R in normal oral mucosa, fibroepithelial polyps, dysplastic oral mucosa and well-differentiated squamous cell carcinomas. Materials and methods: A 3-layered s...

  18. 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.

  19. Nuclear receptor steroidogenic factor 1 directs embryonic stem cells toward the steroidogenic lineage.

    OpenAIRE

    Crawford, P A; Sadovsky, Y.; Milbrandt, J

    1997-01-01

    The orphan nuclear receptor steroidogenic factor 1 (SF-1) is expressed in the adrenal gland and gonads and is an important regulator of the expression of cytochrome P-450 steroidogenic enzymes in cultured cells. Targeted disruption of the SF-1 gene in mice shows that it is a critical participant in the genetic program that promotes the development of urogenital mesoderm into the adrenal gland and gonads. To assess the ability of SF-1 to regulate this differentiation pathway, we ectopically ex...

  20. Characterization of human interleukin-3 receptors on a multi-factor-dependent cell line

    International Nuclear Information System (INIS)

    Recombinant human interleukin-3 (hIL-3) was radioiodinated by Bolton-Hunter method with maintenance of biological activity. Using 125I-hIL-3, hIL-3 receptors were characterized on a multi-factor-dependent cell line TF-1. Equilibrium binding studies revealed the existence of a single class of binding sites (667 +/- 306 sites/cell) with a Kd of 173 +/- 25 pM. Affinity labeling of TF-1 cells with 125I-IL-3 yielded two bands of 150 kDa and 85 kDa, implying molecular weights of 135 kDa and 70 kDa for the hIL-3 receptors

  1. The insulin-like growth factor 1 receptor causes acquired resistance to erlotinib in lung cancer cells with the wild-type epidermal growth factor receptor.

    Science.gov (United States)

    Suda, Kenichi; Mizuuchi, Hiroshi; Sato, Katsuaki; Takemoto, Toshiki; Iwasaki, Takuya; Mitsudomi, Tetsuya

    2014-08-15

    Epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitor (TKI) therapy often provides a dramatic response in lung cancer patients with EGFR mutations. In addition, moderate clinical efficacy of the EGFR-TKI, erlotinib, has been shown in lung cancer patients with the wild-type EGFR. Numerous molecular mechanisms that cause acquired resistance to EGFR-TKIs have been identified in lung cancers with the EGFR mutations; however, few have been reported in lung cancers with the wild-type EGFR. We used H358 lung adenocarcinoma cells lacking EGFR mutations that showed modest sensitivity to erlotinib. The H358 cells acquired resistance to erlotinib via chronic exposure to the drug. The H358 erlotinib-resistant (ER) cells do not have a secondary EGFR mutation, neither MET gene amplification nor PTEN downregulation; these have been identified in lung cancers with the EGFR mutations. From comprehensive screening of receptor tyrosine kinase phosphorylation, we observed increased phosphorylation of insulin-like growth factor 1 receptor (IGF1R) in H358ER cells compared with parental H358 cells. H358ER cells responded to combined therapy with erlotinib and NVP-AEW541, an IGF1R-TKI. Our results indicate that IGF1R activation is a molecular mechanism that confers acquired resistance to erlotinib in lung cancers with the wild-type EGFR. PMID:24458568

  2. 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.

  3. Efficacy of anti-insulin-like growth factor I receptor monoclonal antibody cixutumumab in mesothelioma is highly correlated with insulin growth factor-I receptor sites/cell.

    Science.gov (United States)

    Kalra, Neetu; Zhang, Jingli; Yu, Yunkai; Ho, Mitchell; Merino, Maria; Cao, Liang; Hassan, Raffit

    2012-11-01

    Insulin growth factor-I receptor (IGF-IR) is expressed in mesothelioma and therefore an attractive target for therapy. The antitumor activity of cixutumumab, a humanized monoclonal antibody to IGF-IR, in mesothelioma and relationship to IGF-IR expression was investigated using eight early passage tumor cells obtained from patients, nine established cell lines and an in vivo human mesothelioma tumor xenograft model. Although IGF-IR expression at the mRNA and protein level was present in all mesothelioma cells, using a quantitative ELISA immunoassay, there was considerable variability of IGF-IR expression ranging from 1 to 14 ng/mg of lysate. Using flow cytometry, the number of IGF-IR surface receptors varied from ≈ 2,000 to 50,000 sites/cell. Cells expressing >10,000 sites/cell had greater than 10% growth inhibition when treated with cixutumumab (100 μg/ml). Cixutumumab also induced antibody-dependent cell-mediated toxicity (>10% specific lysis) in cell lines, which had >20,000 IGF-IR sites/cell. Treatment with cixutumumab decreased phosphorylation of IGF-IR, Akt and Erk in cell lines, H226 and H28 having 24,000 and 51,000 IGF-IR sites/cell, respectively, but not in the cell line H2052 with 3,000 IGF-IR sites/cell. In vivo, cixutumumab treatment delayed growth of H226 mesothelioma tumor xenografts in mice and improved the overall survival of these mice compared to mice treated with saline (p < 0.004). Our results demonstrate that the antitumor efficacy of cixutumumab including inhibition of IGF-IR downstream signaling is highly correlated with IGF-IR sites/cell. A phase II clinical trial of cixutumumab is currently ongoing for the treatment of patients with mesothelioma. PMID:22323052

  4. Correlation between hormone dependency and the regulation of epidermal growth factor receptor by tumor promoters in human mammary carcinoma cells

    International Nuclear Information System (INIS)

    The effects of the tumor promoter phorbol 12-tetradecanoate 13-acetate (TPA) on the epidermal growth factor (EGF) receptor levels were investigated in hormone-dependent (MCF-7, T-47-D, and ZR-75-1) and hormone-independent (MDA-MB-231, HBL-100, and BT-20) human mammary carcinoma cell lines. In the absence of TPA, hormone-independent cell lines contained high concentrations of low-affinity EGF receptors, whereas hormone-dependent cell lines exhibited low concentrations of high-affinity receptors. TPA causes a change of the receptor from a high- to the low-affinity state in hormone-dependent cell lines, as well as in the hormone-independent HBL-100, whereas the affinity remained unchanged in MDA-MB-231 and BT-20 cells. Tumor promoters such as TPA or teleocidin inhibited the proliferation of these cell lines at concentrations above 10 μM with the exception of the T-47-D cells. Evaluation of different TPA analogs indicated a positive correlation between the growth-inhibitory effects and their ability to stimulate the subcellular redistribution of protein kinase C activity in MCF-7 cells. These data suggest a protein kinase C-mediated down-regulation of the progesterone receptor concentration and of the EGF receptor affinity, which is supposed to mediate the mitogenic response. Furthermore, these results support the hypothesis that the tumor-derived growth factors induced by estradiol act via the EGF receptor in hormone-dependent mammary carcinoma cells

  5. Suppression of estrogen receptor-alpha transactivation by thyroid transcription factor-2 in breast cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Park, Eunsook; Gong, Eun-Yeung [Hormone Research Center, School of Biological Sciences and Technology, Chonnam National University, Gwangju 500-757 (Korea, Republic of); Romanelli, Maria Grazia [Department of Life and Reproduction Sciences, University of Verona, Strada le Grazie 8, 37134 Verona (Italy); Lee, Keesook, E-mail: klee@chonnam.ac.kr [Hormone Research Center, School of Biological Sciences and Technology, Chonnam National University, Gwangju 500-757 (Korea, Republic of)

    2012-05-11

    Highlights: Black-Right-Pointing-Pointer TTF-2 was expressed in mammary glands and breast cancer cells. Black-Right-Pointing-Pointer TTF-2 repressed ER{alpha} transactivation. Black-Right-Pointing-Pointer TTF-2 inhibited the proliferation of breast cancer cells. -- Abstract: Estrogen receptors (ERs), which mediate estrogen actions, regulate cell growth and differentiation of a variety of normal tissues and hormone-responsive tumors through interaction with cellular factors. In this study, we show that thyroid transcription factor-2 (TTF-2) is expressed in mammary gland and acts as ER{alpha} co-repressor. TTF-2 inhibited ER{alpha} transactivation in a dose-dependent manner in MCF-7 breast cancer cells. In addition, TTF-2 directly bound to and formed a complex with ER{alpha}, colocalizing with ER{alpha} in the nucleus. In MCF-7/TTF-2 stable cell lines, TTF-2 repressed the expression of endogenous ER{alpha} target genes such as pS2 and cyclin D1 by interrupting ER{alpha} binding to target promoters and also significantly decreased cell proliferation. Taken together, these data suggest that TTF-2 may modulate the function of ER{alpha} as a corepressor and play a role in ER-dependent proliferation of mammary cells.

  6. Fibroblast growth factor receptor 3 protein is overexpressed in oral and oropharyngeal squamous cell carcinoma.

    Science.gov (United States)

    Koole, Koos; van Kempen, Pauline M W; Swartz, Justin E; Peeters, Ton; van Diest, Paul J; Koole, Ron; van Es, Robert J J; Willems, Stefan M

    2016-02-01

    Fibroblast growth factor receptor 3 (FGFR3) is a member of the fibroblast growth factor receptor tyrosine kinase family. It has been identified as a promising therapeutic target in multiple types of cancer. We have investigated FGFR3 protein expression and FGFR3 gene copy-numbers in a single well-documented cohort of oral and oropharyngeal squamous cell carcinoma. Tissue microarray sets containing 452 formalin-fixed paraffin-embedded tissues were immunohistochemically stained with an anti-FGFR3 antibody and hybridized with a FGFR3 fluorescence in situ hybridization probe. FGFR3 protein expression was correlated with clinicopathological and survival data, which were retrieved from electronic medical records. FGFR3 mRNA data of 522 head and neck squamous cell carcinoma (HNSCC) were retrieved from The Cancer Genome Atlas (TCGA). Fibroblast growth factor receptor 3 (FGFR3) protein was overexpressed in 48% (89/185) of oral and 59% (124/211) of oropharyngeal squamous cell carcinoma. Overexpression of FGFR3 protein was not related to overall survival or disease-free survival in oral (HR[hazard ratio]: 0.94; 95% CI: 0.64-1.39; P = 0.77, HR: 0.94; 95% CI: 0.65-1.36; P = 0.75) and oropharyngeal squamous cell carcinoma (HR: 1.21; 95% CI: 0.81-1.80; P = 0.36, HR: 0.42; 95% CI: 0.79-1.77; P = 0.42). FGFR3 mRNA was upregulated in 3% (18/522) of HNSCC from the TCGA. The FGFR3 gene was gained in 0.6% (1/179) of oral squamous cell carcinoma but no amplification was found in oral and oropharyngeal squamous cell carcinoma. In conclusion, FGFR3 protein is frequently overexpressed in oral and oropharyngeal squamous cell carcinoma. Therefore, it may serve as a potential therapeutic target for FGFR3-directed therapies in oral and oropharyngeal squamous cell carcinoma. PMID:26711175

  7. AZD9291 in epidermal growth factor receptor inhibitor—resistant non-small-cell lung cancer

    OpenAIRE

    Stinchcombe, Thomas E.

    2016-01-01

    Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) in advanced EGFR mutant non-small cell lung cancer have an objective response rate (ORR) of approximately 60–70% and a median progression free-survival (PFS) of approximately 10-13 months. Studies of tumor biopsies performed after progression on EGFR TKI revealed that 50-60% of EGFR mutant NSCLC developed an EGFR exon 20 T790M mutation as a mechanism of acquired resistance. AZD9291 is a third generation irreversible EGF...

  8. Epidermal growth factor receptor and proliferating cell nuclear antigen in astrocytomas

    Directory of Open Access Journals (Sweden)

    Maiti Arpan

    2008-01-01

    Full Text Available Aims: The involvement of various growth factors, growth factor receptors and proliferative markers in the molecular pathogenesis of astrocytic neoplasms are being studied extensively. Epidermal Growth Factor Receptor (EGFR gene overexpression occurs in nearly 50% of cases of glioblastoma. Since EGFR and proliferating cell nuclear antigen (PCNA are involved in mitogenic signal transduction and cellular proliferation pathway, we have studied the correlation between the expression of EGFR and PCNA labeling index in astrocytic tumors. Materials and Methods: We investigated the immunohistochemical expression of EGFR and PCNA using the appropriate monoclonal antibodies in 40 cases of astrocytic tumors of which 21 cases were glioblastoma, eight cases were Grade III or anaplastic astrocytomas and six cases were Grade II or diffuse astrocytomas and five cases were Grade I or pilocytic astrocytomas. Results: Both the EGFR expression and PCNA labeling index increase with increasing grades of astrocytomas with a significantly high percentage of cells showing positive staining for both EGFR and PCNA in GBM and Grade III astrocytomas compared to Grade II astrocytomas. The expression levels of both EGFR and PCNA were low in Grade I or pilocytic astrocytomas. Conclusions: A significant correlation was found between EGFR overexpression and PCNA labeling index in Grade III and Grade II astrocytomas and glioblastoma. These suggest that the tumor proliferation, at least in higher grades of astrocytomas is dependent in some measure on EGF and EGFR-related signaling pathways.

  9. 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.

  10. Nuclear factor of activated T cells negatively regulates expression of the tumor necrosis factor receptor-related 2 gene in T cells

    OpenAIRE

    Kim, Woon-Ki; Sul, Ok-Ju; Kwak, Jung-Sook; Hur, Hye-Young; Latour, Anne M.; Koller, Beverly H.; Kwon, Byoung S.; Jeong, Choon-Soo

    2010-01-01

    Tumor necrosis factor receptor-related 2 (TR2, HVEM or TNFRSF-14) plays an important role in immune responses, however, the mechanisms regulating its expression are unclear. To understand the control of TR2 gene expression, we studied the upstream region of the gene. Gel supershift assays revealed inducible binding of nuclear factor of activated T cells (NFAT) to a putative NFAT site within the TR2 promoter. Furthermore, cotransfection of a dominant negative NFAT construct, or siRNA for NFAT,...

  11. Effects of recombinant epidermal growth factor receptor antisense adenovirus combined with irradiation on breast cancer cells

    International Nuclear Information System (INIS)

    Objective: To investigate the effects of a recombinant antisense adenovirus for epidermal growth factor receptor (EGFR) combined with irradiation on breast cancer cells. Methods: Human EGFR cDNA fragment was subcloned in the opposite orientation to the cytomegaloviral promoter and inserted into a E1/E3-deleted type 5 adenoviral vector to obtain AdE5 construct which expresses EGFR antisense RNA. Combined with γ-ray irradiation, its effects on clonogenicity and cell cycle phase distribution were studied in a human breast cancer line MDA-MB-23. Results: EGFR protein expression was dramatically inhibited in MDA-MB-231 cells after AdE5 infection. The post-irradiation clonogenicity was reduced by AdE5 in a viral and irradiation dose-dependent manner. Further cytometric analysis showed that AdE5 infection at a MOI of 300 pfu/cell induced a cell cycle progression from radio-resistant G0 + G1 phases to radiosensitive G2 + M phases, resulting in a synergistic effect after combination of these two treatments. Conclusions: The transduction of EGFR antisense RNA by adenoviral vector is effective for antisense strategy targeting EGFR, and increases the cell-killing effect of ionizing radiation on breast cancer cells.(authors)

  12. H4 histamine receptors mediate cell cycle arrest in growth factor-induced murine and human hematopoietic progenitor cells.

    Directory of Open Access Journals (Sweden)

    Anne-France Petit-Bertron

    Full Text Available The most recently characterized H4 histamine receptor (H4R is expressed preferentially in the bone marrow, raising the question of its role during hematopoiesis. Here we show that both murine and human progenitor cell populations express this receptor subtype on transcriptional and protein levels and respond to its agonists by reduced growth factor-induced cell cycle progression that leads to decreased myeloid, erythroid and lymphoid colony formation. H4R activation prevents the induction of cell cycle genes through a cAMP/PKA-dependent pathway that is not associated with apoptosis. It is mediated specifically through H4R signaling since gene silencing or treatment with selective antagonists restores normal cell cycle progression. The arrest of growth factor-induced G1/S transition protects murine and human progenitor cells from the toxicity of the cell cycle-dependent anticancer drug Ara-C in vitro and reduces aplasia in a murine model of chemotherapy. This first evidence for functional H4R expression in hematopoietic progenitors opens new therapeutic perspectives for alleviating hematotoxic side effects of antineoplastic drugs.

  13. Estrogen receptor coregulators and pioneer factors: The orchestrators of mammary gland cell fate and development

    Directory of Open Access Journals (Sweden)

    Bramanandam eManavathi

    2014-08-01

    Full Text Available The 17-beta estradiol (E2, a steroid hormone, which play critical role in various cellular processes such as cell proliferation, differentiation, migration and apoptosis, is essential for reproduction and mammary gland development. E2 actions are mediated by two classical nuclear hormone receptors, estrogen receptor alpha and beta (ERs. The activity of ERs depends on the coordinate activity of ligand binding, posttranslational modification, and importantly their interaction with their partner proteins called ‘coregulators’. Because majority of breast cancers are ERalpha positive and coregulators are proved to be crucial for ER transcriptional activity, an increased interest in the field has led to the identification of a large number of coregulators. In the last decade, gene knockout studies using mouse models provided impetus to our further understanding of the role of these coregulators in mammary gland development. Several coregulators appear to be critical for terminal end bud formation, ductal branching and alveologenesis during mammary gland development. The emerging studies support that, in addition to these coregulators, the other ER partner proteins ‘pioneering factors’ also seems to contribute significantly to E2 signaling and mammary cell fate. This review discusses emerging themes in coregulator- and pioneering factor-mediated action on ER functions, particularly their role in mammary gland cell fate and development.

  14. Expression of ciliary neurotrophic factor (CNTF) and its tripartite receptor complex by cells of the human optic nerve head

    OpenAIRE

    Liu, Xiaochun; Clark, Abbot F.; Wordinger, Robert J.

    2007-01-01

    Purpose Ciliary neurotrophic factor (CNTF) promotes gene expression, cell survival and differentiation in various types of peripheral and central neurons, glia and nonneural cells. The level of CNTF rises rapidly upon injury to neural tissue, suggesting that CNTF exerts its cytoprotective effects after release from cells via mechanisms induced by cell injury. The purpose of this study was to determine if cells in the optic nerve head express CNTF and its tripartite receptor complex. Methods W...

  15. 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)

    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 DMF10% 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

  16. Homeobox A7 increases cell proliferation by up-regulation of epidermal growth factor receptor expression in human granulosa cells

    Directory of Open Access Journals (Sweden)

    Yanase Toshihiko

    2010-06-01

    Full Text Available Abstract Background Homeobox (HOX genes encode transcription factors, which regulate cell proliferation, differentiation, adhesion, and migration. The deregulation of HOX genes is frequently associated with human reproductive system disorders. However, knowledge regarding the role of HOX genes in human granulosa cells is limited. Methods To determine the role of HOXA7 in the regulation and associated mechanisms of cell proliferation in human granulosa cells, HOXA7 and epidermal growth factor receptor (EGFR expressions were examined in primary granulosa cells (hGCs, an immortalized human granulosa cell line, SVOG, and a granulosa tumor cell line, KGN, by real-time PCR and Western blotting. To manipulate the expression of HOXA7, the HOXA7 specific siRNA was used to knockdown HOXA7 in KGN. Conversely, HOXA7 was overexpressed in SVOG by transfection with the pcDNA3.1-HOAX7 vector. Cell proliferation was measured by the MTT assay. Results Our results show that HOXA7 and EGFR were overexpressed in KGN cells compared to hGCs and SVOG cells. Knockdown of HOXA7 in KGN cells significantly decreased cell proliferation and EGFR expression. Overexpression of HOXA7 in SVOG cells significantly promoted cell growth and EGFR expression. Moreover, the EGF-induced KGN proliferation was abrogated, and the activation of downstream signaling was diminished when HOXA7 was knocked down. Overexpression of HOXA7 in SVOG cells had an opposite effect. Conclusions Our present study reveals a novel mechanistic role for HOXA7 in modulating granulosa cell proliferation via the regulation of EGFR. This finding contributes to the knowledge of the pro-proliferation effect of HOXA7 in granulosa cell growth and differentiation.

  17. Deficiency of platelet-derived growth factor receptor-α-positive cells in Hirschsprung's disease colon

    Science.gov (United States)

    O’Donnell, Anne-Marie; Coyle, David; Puri, Prem

    2016-01-01

    AIM: To investigate whether the expression of platelet-derived growth factor receptor-α-positive (PDGFRα+)-cells is altered in Hirschsprung’s disease (HD). METHODS: HD tissue specimens (n = 10) were collected at the time of pull-through surgery, while colonic control samples were obtained at the time of colostomy closure in patients with imperforate anus (n = 10). Immunolabelling of PDGFRα+-cells was visualized using confocal microscopy to assess the distribution of these cells, while Western blot analysis was undertaken to quantify PDGFRα protein expression. RESULTS: Confocal microscopy revealed PDGFRα+-cells within the mucosa, myenteric plexus and smooth muscle in normal controls, with a marked reduction in PDGFRα+-cells in the HD specimens. Western blotting revealed high levels of PDGFRα protein expression in normal controls, while there was a striking decrease in PDGFRα protein expression in the HD colon. CONCLUSION: These findings suggest that the altered distribution of PDGFRα+-cells in both the aganglionic and ganglionic HD bowel may contribute to the motility dysfunction in HD. PMID:27022215

  18. Epidermal growth factor receptor is required for estradiol-stimulated bovine satellite cell proliferation.

    Science.gov (United States)

    Reiter, B C; Kamanga-Sollo, E; Pampusch, M S; White, M E; Dayton, W R

    2014-07-01

    The objective of this study was to assess the role of the epidermal growth factor receptor (EGFR) in estradiol-17β (E2)-stimulated proliferation of cultured bovine satellite cells (BSCs). Treatment of BSC cultures with AG1478 (a specific inhibitor of EGFR tyrosine kinase activity) suppresses E2-stimulated BSC proliferation (P LR3-IGF-1 (an IGF1 analogue that binds normally to the insulin-like growth factor receptor (IGFR)-1 but has little or no affinity for IGF binding proteins) in cultured BSCs (P < 0.05). Even though EGFR siRNA treatment has no effect on IGFR-1β mRNA expression in cultured BSCs, IGFR-1β protein level is substantially reduced in BSCs treated with EGFR siRNA. These data suggest that EGFR silencing results in post-transcriptional modifications that result in decreased IGFR-1β protein levels. Although it is clear that functional EGFR is necessary for E2-stimulated proliferation of BSCs, the role of EGFR is not clear. Transactivation of EGFR may directly stimulate proliferation, or EGFR may function to maintain the level of IGFR-1β which is necessary for E2-stimulated proliferation. It also is possible that the role of EGFR in E2-stimulated BSC proliferation may involve both of these mechanisms. PMID:24906928

  19. Glutamate receptor antagonists and growth factors modulate dentate granule cell neurogenesis in organotypic, rat hippocampal slice cultures

    DEFF Research Database (Denmark)

    Poulsen, Frantz Rom; Blaabjerg, Morten; Montero, Maria;

    2005-01-01

    Generation of dentate granule cells and its modulation by glutamate receptor antagonists, growth factors and pilocarpine-induced seizure-like activity was investigated in rat hippocampal slice cultures derived from 1-week-old rats and grown for 2 weeks. Focussing on the dentate granule cell layer...

  20. 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

  1. Oak ellagitannins suppress the phosphorylation of the epidermal growth factor receptor in human colon carcinoma cells.

    Science.gov (United States)

    Fridrich, Diana; Glabasnia, Arne; Fritz, Jessica; Esselen, Melanie; Pahlke, Gudrun; Hofmann, Thomas; Marko, Doris

    2008-05-14

    The ellagitannins castalagin and vescalagin, and the C-glycosides grandinin and roburin E as well as ellagic acid were found to potently inhibit the growth of human colon carcinoma cells (HT29) in vitro. In a cell-free system these compounds were identified as potent inhibitors of the protein tyrosine kinase activity of the epidermal growth factor receptor (EGFR) with IC 50 values in the low nanomolar range. To address the question of whether the interference with the activity of the isolated EGFR also plays a role within intact cells, effects on the phosphorylation status of the EGFR, as a measure for its activity, were determined in HT29 cells. As exemplified for castalagin and grandinin, both the nonglycosylated and the glycosylated ellagitannins effectively suppressed EGFR phosphorylation, but only at concentrations > or =10 microM, thus, in a concentration range where growth inhibition was observed. These results indicate that the suppression of EGFR-mediated signaling might contribute to the growth inhibitory effects of these compounds present in oak-matured wines and spirits such as whiskey. In contrast, despite substantial growth inhibitory properties, ellagic acid did not significantly affect EGFR phosphorylation in HT29 cells up to 100 microM. PMID:18419129

  2. 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...

  3. The Clinical Significance of the Insulin-Like Growth Factor-1 Receptor Polymorphism in Non-Small-Cell Lung Cancer with Epidermal Growth Factor Receptor Mutation.

    Science.gov (United States)

    Liu, Tu-Chen; Hsieh, Ming-Ju; Liu, Ming-Che; Chiang, Whei-Ling; Tsao, Thomas Chang-Yao; Yang, Shun-Fa

    2016-01-01

    The insulin-like growth factor 1 (IGF1) signaling pathway mediates multiple cancer cell biological processes. IGF1 receptor (IGF1R) expression has been used as a reporter of the clinical significance of non-small-cell lung carcinoma (NSCLC). However, the association between IGF1R genetic variants and the clinical utility of NSCLC positive for epidermal growth factor receptor (EGFR) mutation is not clear. The current study investigated the association between the IGF1R genetic variants, the occurrence of EGFR mutations, and clinicopathological characteristics in NSCLC patients. A total of 452 participants, including 362 adenocarcinoma lung cancer and 90 squamous cell carcinoma lung cancer patients, were selected for analysis of IGF1R genetic variants (rs7166348, rs2229765, and rs8038415) using real-time polymerase chain reaction (PCR)genotyping. The results indicated that GA + AA genotypes of IGF1R rs2229765 were significantly associated with EGFR mutation in female lung adenocarcinoma patients (odds ratio (OR) = 0.39, 95% confidence interval (CI) = 0.17-0.87). Moreover, The GA + AA genotype IGF1R rs2229765 was significantly associated with EGFR L858R mutation (p = 0.02) but not with the exon 19 in-frame deletion. Furthermore, among patients without EGFR mutation, those who have at least one polymorphic A allele of IGF1R rs7166348 have an increased incidence of lymph node metastasis when compared with those patients homozygous for GG (OR, 2.75; 95% CI, 1.20-2.31). Our results showed that IGF1R genetic variants are related to EGFR mutation in female lung adenocarcinoma patients and may be a predictive factor for tumor lymph node metastasis in Taiwanese patients with NSCLC. PMID:27213344

  4. Up-regulation of interleukin 4/B-cell stimulatory factor 1 receptor expression

    International Nuclear Information System (INIS)

    The expression of interleukin 4 (IL-4) receptors on resting T and B lymphocytes was enhanced 4- to 8-fold by IL-4 stimulation of these cells. Other agents such as lipopolysaccharide and anti-IgM for B cells and concanvalain A for T cells also caused increased IL-4 receptor expression, although to a somewhat smaller degree than IL-4. Using a newly developed flow cytometric analysis based on the binding of biotinylated IL-4 and phycoerythrin-streptavidin, it was observed that receptor up-regulation in a T-cell population treated with IL-4 was a feature of the majority of the T cells. Analysis of IL-4 by cross-linkage of 125I-labeled IL-4 to IL-4 receptor with disuccinimidyl suberate indicated that the IL-4 IL-4 receptor complex was the same size in the resting and up-regulated cells, implying that the same receptor species found in resting cells was up-regulated in response IL-4

  5. Epidermal Growth Factor Receptor Mutations and Radiotherapy 
in Non-small Cell Lung Cancer

    Directory of Open Access Journals (Sweden)

    Xing ZHONG

    2013-03-01

    Full Text Available Radiotherapy plays a pivotal role in the treatment for lung cancer. Epidermal growth factor receptor (EGFR mutation in non-small cell lung cancer (NSCLC which predicts tyrosine kinase inhibitor (TKI treatment response may also has effect on radiation response. NSCLC harboring kinase-domain mutations in EGFR exhibits enhanced radio-sensitivity due to dramatically diminished capacity to resolve radiation-induced DSBs (DNA double-strand breaks associating with the inefficiency of EGFR nuclear translocation. Recently, several preliminary clinical studies show certain efficacy of concurrent EGFR tyrosine kinase inhibitors and radiotherapy. However its further response in EGFR-mutated NSCLC is unclear. The correlation between EGFR mutation genotype and the radiotherapy response and clinical outcome is worthy of further study.

  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...... not accurately reveal the EGFR expression. In addition, EGFR expression may also change during chemotherapy. The current study investigates the magnitude of these two issues. MATERIALS AND METHODS: EGFR expression in diagnostic biopsies and resection specimen was compared in 53 NSCLC patients stage T1......-4N0-1M0 treated with surgery without preceding chemotherapy (OP group), and 65 NSCLC patients stage T1-3N0-2M0 (NAC group) treated with preoperative carboplatin and paclitaxel in order to evaluate the discordance of EGFR expression between samples. RESULTS: Discordance between tumors dichotomized...

  7. Modulation of B-cell receptor and microenvironment signaling by a guanine exchange factor in B-cell malignancies

    Institute of Scientific and Technical Information of China (English)

    Wei Liao; Sanjai Sharma

    2016-01-01

    Objective: Chronic lymphocytic leukemia (CLL) and mantle cell lymphoma (MCL) cells over-express a guanine exchange factor (GEF), Rasgrf-1. This GEF increases active Ras as it catalyzes the removal of GDP from Ras so that GTP can bind and activate Ras. This study aims to study the mechanism of action of Rasgrf-1 in B-cell malignancies. Methods: N-terminus truncated Rasgrf-1 variants have a higher GEF activity as compared to the full-length transcript therefore a MCL cell line with stable over-expression of truncated Rasgrf-1 was established. The B-cell receptor (BCR) and chemokine signaling pathways were compared in the Rasgrf-1 over-expressing and a control transfected cell line. Results: Cells over-expressing truncated form of Rasgrf-1 have a higher proliferative rate as compared to control transfected cells. BCR was activated by lower concentrations of anti-IgM antibody in Rasgrf-1 over-expressing cells as compared to control cells indicating that these cells are more sensitive to BCR signaling. BCR signaling also phosphorylates Rasgrf-1 that further increases its GEF function and amplifies BCR signaling. This activation of Rasgrf-1 in over-expressing cells resulted in a higher expression of phospho-ERK, AKT, BTK and PKC-alpha as compared to control cells. Besides BCR, Rasgrf-1 over-expressing cells were also more sensitive to microenvironment stimuli as determined by resistance to apoptosis, chemotaxis and ERK pathway activation. Conclusions: This GEF protein sensitizes B-cells to BCR and chemokine mediated signaling and also upregulates a number of other signaling pathways which promotes growth and survival of these cells.

  8. Trafficking of epidermal growth factor receptor ligands in polarized epithelial cells.

    Science.gov (United States)

    Singh, Bhuminder; Coffey, Robert J

    2014-01-01

    A largely unilamellar epithelial layer lines body cavities and organ ducts such as the digestive tract and kidney tubules. This polarized epithelium is composed of biochemically and functionally separate apical and basolateral surfaces. The epidermal growth factor receptor (EGFR) signaling pathway is a critical regulator of epithelial homeostasis and is perturbed in a number of epithelial disorders. It is underappreciated that in vivo EGFR signaling is most often initiated by cell-surface delivery and processing of one of seven transmembrane ligands, resulting in release of the soluble form that binds EGFR. In polarized epithelial cells, EGFR is restricted largely to the basolateral surface, and apical or basolateral ligand delivery therefore has important biological consequences. In vitro approaches have been used to study the biosynthesis, cell-surface delivery, proteolytic processing, and release of soluble EGFR ligands in polarized epithelial cells. We review these results, discuss their relevance to normal physiology, and demonstrate the pathophysiological consequences of aberrant trafficking. These studies have uncovered a rich diversity of apico-basolateral trafficking mechanisms among the EGFR ligands, provided insights into the pathogenesis of an inherited magnesium-wasting disorder of the kidney (isolated renal hypomagnesemia), and identified a new mode of EGFR ligand signaling via exosomes. PMID:24215440

  9. Microarray Analyses Reveal Marked Differences in Growth Factor and Receptor Expression Between 8-Cell Human Embryos and Pluripotent Stem Cells.

    Science.gov (United States)

    Vlismas, Antonis; Bletsa, Ritsa; Mavrogianni, Despina; Mamali, Georgina; Pergamali, Maria; Dinopoulou, Vasiliki; Partsinevelos, George; Drakakis, Peter; Loutradis, Dimitris; Kiessling, Ann A

    2016-01-15

    Previous microarray analyses of RNAs from 8-cell (8C) human embryos revealed a lack of cell cycle checkpoints and overexpression of core circadian oscillators and cell cycle drivers relative to pluripotent human stem cells [human embryonic stem cells/induced pluripotent stem (hES/iPS)] and fibroblasts, suggesting growth factor independence during early cleavage stages. To explore this possibility, we queried our combined microarray database for expression of 487 growth factors and receptors. Fifty-one gene elements were overdetected on the 8C arrays relative to hES/iPS cells, including 14 detected at least 80-fold higher, which annotated to multiple pathways: six cytokine family (CSF1R, IL2RG, IL3RA, IL4, IL17B, IL23R), four transforming growth factor beta (TGFB) family (BMP6, BMP15, GDF9, ENG), one fibroblast growth factor (FGF) family [FGF14(FH4)], one epidermal growth factor member (GAB1), plus CD36, and CLEC10A. 8C-specific gene elements were enriched (73%) for reported circadian-controlled genes in mouse tissues. High-level detection of CSF1R, ENG, IL23R, and IL3RA specifically on the 8C arrays suggests the embryo plays an active role in blocking immune rejection and is poised for trophectoderm development; robust detection of NRG1, GAB1, -2, GRB7, and FGF14(FHF4) indicates novel roles in early development in addition to their known roles in later development. Forty-four gene elements were underdetected on the 8C arrays, including 11 at least 80-fold under the pluripotent cells: two cytokines (IFITM1, TNFRSF8), five TGFBs (BMP7, LEFTY1, LEFTY2, TDGF1, TDGF3), two FGFs (FGF2, FGF receptor 1), plus ING5, and WNT6. The microarray detection patterns suggest that hES/iPS cells exhibit suppressed circadian competence, underexpression of early differentiation markers, and more robust expression of generic pluripotency genes, in keeping with an artificial state of continual uncommitted cell division. In contrast, gene expression patterns of the 8C embryo suggest that

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

    Science.gov (United States)

    Behdani, Mahdi; Zeinali, Sirous; Karimipour, Morteza; Khanahmad, Hossein; Asadzadeh, Nader; Azadmanesh, Kayhan; Seyed, Negar; Baniahmad, Seyed Farzad; Anbouhi, Mahdi Habibi

    2012-01-01

    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. PMID:23326765

  11. 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.

  12. Degradation of Epidermal Growth Factor Receptor Mediates Dasatinib-Induced Apoptosis in Head and Neck Squamous Cell Carcinoma Cells

    Directory of Open Access Journals (Sweden)

    Yu-Chin Lin

    2012-06-01

    Full Text Available Epidermal growth factor receptor (EGFR is an important oncoprotein that promotes cell growth and proliferation. Dasatinib, a bcr-abl inhibitor, has been approved clinically for the treatment of chronic myeloid leukemia and demonstrated to be effective against solid tumors in vitro through Src inhibition. Here, we disclose that EGFR degradation mediated dasatinib-induced apoptosis in head and neck squamous cell carcinoma (HNSCC cells. HNSCC cells, including Ca9-22, FaDu, HSC3, SAS, SCC-25, and UMSCC1, were treated with dasatinib, and cell viability, apoptosis, and underlying signal transduction were evaluated. Dasatinib exhibited differential sensitivities against HNSCC cells. Growth inhibition and apoptosis were correlated with its inhibition on Akt, Erk, and Bcl-2, irrespective of Src inhibition. Accordingly, we found that down-regulation of EGFR was a determinant of dasatinib sensitivity. Lysosome inhibitor reversed dasatinib-induced EGFR down-regulation, and c-cbl activity was increased by dasatinib, indicating that dasatinib-induced EGFR down-regulation might be through c-cbl-mediated lysosome degradation. Increased EGFR activation by ligand administration rescued cells from dasatinib-induced apoptosis, whereas inhibition of EGFR enhanced its apoptotic effect. Estrogen receptor α (ERα was demonstrated to play a role in Bcl-2 expression, and dasatinib inhibited ERα at the pretranslational level. ERα was associated with EGFR in dasatinib-treated HNSCC cells. Furthermore, the xenograft model showed that dasatinib inhibited HSC3 tumor growth through in vivo down-regulation of EGFR and ERα. In conclusion, degradation of EGFR is a novel mechanism responsible for dasatinib-induced apoptosis in HNSCC cells.

  13. Detecting the epidermal growth factor receptors status in non-small cell lung cancer

    Institute of Scientific and Technical Information of China (English)

    MENG Xue; YU Jin-ming

    2011-01-01

    Non-small cell lung cancer is one of the leading causes of all cancer deaths,but despite years of research,it is still difficult to predict the response and clinical outcome of the disease.In recent years,new treatment strategies targeting the epidermal growth factor receptors (EGFR) have been developed.EGFR is one of the most frequently over expressed proteins in various cancers,including lung cancer,and signaling through this receptor has been known to cause tumor progression as well as resistance to different treatments.Therefore,EGFR has become an attractive target for various treatment strategies.However,it is important to note that not all patients with lung cancer are suitable for targeted treatment,and that patients should be selected for this treatment.Several studies have proven that the status of the EGFR can be both an indicator of suitability for treatment with,and predict the likelihood of response to EGFR targeted therapy.There are many standard techniques to be used for the detection of EGFR.This overview summarizes the ongoing and future investigations to determine the status of the EGFR.

  14. Differential Expression of Insulin-Like Growth Factor-I Receptor on Human Bone Marrow-Derived Mesenchymal Stem Cells Induced by Tumor Necrosis Factor

    OpenAIRE

    Sahraean, Z.; Ayatollahi, M.; Yaghobi, R.; Ziaei, R.

    2014-01-01

    Background: Cell-based therapy has been implicated in the treatment of liver diseases. Mesenchymal stem cells from various sources such as bone marrow are available. These cells are one of the major candidates in cell therapy. The production of insulin-like growth factor-I increases in the regenerating organ. The insulin-like growth factor-I in liver regeneration is effective after binding to insulin-like growth factor-I receptor. Objective: To test our hypothesis that tumor necrosis factor-α...

  15. Deficiency of the B Cell-Activating Factor Receptor Results in Limited CD169+ Macrophage Function during Viral Infection

    OpenAIRE

    Xu, Haifeng C.; Huang, Jun; Khairnar, Vishal; Duhan, Vikas; Pandyra, Aleksandra A; Grusdat, Melanie; Shinde, Prashant; McIlwain, David R.; Maney, Sathish Kumar; Gommerman, Jennifer; Löhning, Max; Ohashi, Pamela S.; Mak, Tak W; Pieper, Kathrin; Sic, Heiko

    2015-01-01

    The B cell-activating factor (BAFF) is critical for B cell development and humoral immunity in mice and humans. While the role of BAFF in B cells has been widely described, its role in innate immunity remains unknown. Using BAFF receptor (BAFFR)-deficient mice, we characterized BAFFR-related innate and adaptive immune functions following infection with vesicular stomatitis virus (VSV) and lymphocytic choriomeningitis virus (LCMV). We identified a critical role for BAFFR signaling in the gener...

  16. Microenvironmental stiffness enhances glioma cell proliferation by stimulating epidermal growth factor receptor signaling.

    Directory of Open Access Journals (Sweden)

    Vaibhavi Umesh

    Full Text Available The aggressive and rapidly lethal brain tumor glioblastoma (GBM is associated with profound tissue stiffening and genomic lesions in key members of the epidermal growth factor receptor (EGFR pathway. Previous studies from our laboratory have shown that increasing microenvironmental stiffness in culture can strongly enhance glioma cell behaviors relevant to tumor progression, including proliferation, yet it has remained unclear whether stiffness and EGFR regulate proliferation through common or independent signaling mechanisms. Here we test the hypothesis that microenvironmental stiffness regulates cell cycle progression and proliferation in GBM tumor cells by altering EGFR-dependent signaling. We began by performing an unbiased reverse phase protein array screen, which revealed that stiffness modulates expression and phosphorylation of a broad range of signals relevant to proliferation, including members of the EGFR pathway. We subsequently found that culturing human GBM tumor cells on progressively stiffer culture substrates both dramatically increases proliferation and facilitates passage through the G1/S checkpoint of the cell cycle, consistent with an EGFR-dependent process. Western Blots showed that increasing microenvironmental stiffness enhances the expression and phosphorylation of EGFR and its downstream effector Akt. Pharmacological loss-of-function studies revealed that the stiffness-sensitivity of proliferation is strongly blunted by inhibition of EGFR, Akt, or PI3 kinase. Finally, we observed that stiffness strongly regulates EGFR clustering, with phosphorylated EGFR condensing into vinculin-positive focal adhesions on stiff substrates and dispersing as microenvironmental stiffness falls to physiological levels. Our findings collectively support a model in which tissue stiffening promotes GBM proliferation by spatially and biochemically amplifying EGFR signaling.

  17. Microenvironmental stiffness enhances glioma cell proliferation by stimulating epidermal growth factor receptor signaling.

    Science.gov (United States)

    Umesh, Vaibhavi; Rape, Andrew D; Ulrich, Theresa A; Kumar, Sanjay

    2014-01-01

    The aggressive and rapidly lethal brain tumor glioblastoma (GBM) is associated with profound tissue stiffening and genomic lesions in key members of the epidermal growth factor receptor (EGFR) pathway. Previous studies from our laboratory have shown that increasing microenvironmental stiffness in culture can strongly enhance glioma cell behaviors relevant to tumor progression, including proliferation, yet it has remained unclear whether stiffness and EGFR regulate proliferation through common or independent signaling mechanisms. Here we test the hypothesis that microenvironmental stiffness regulates cell cycle progression and proliferation in GBM tumor cells by altering EGFR-dependent signaling. We began by performing an unbiased reverse phase protein array screen, which revealed that stiffness modulates expression and phosphorylation of a broad range of signals relevant to proliferation, including members of the EGFR pathway. We subsequently found that culturing human GBM tumor cells on progressively stiffer culture substrates both dramatically increases proliferation and facilitates passage through the G1/S checkpoint of the cell cycle, consistent with an EGFR-dependent process. Western Blots showed that increasing microenvironmental stiffness enhances the expression and phosphorylation of EGFR and its downstream effector Akt. Pharmacological loss-of-function studies revealed that the stiffness-sensitivity of proliferation is strongly blunted by inhibition of EGFR, Akt, or PI3 kinase. Finally, we observed that stiffness strongly regulates EGFR clustering, with phosphorylated EGFR condensing into vinculin-positive focal adhesions on stiff substrates and dispersing as microenvironmental stiffness falls to physiological levels. Our findings collectively support a model in which tissue stiffening promotes GBM proliferation by spatially and biochemically amplifying EGFR signaling. PMID:25000176

  18. Androgen and retinoic acid interaction in LNCaP cells, effects on cell proliferation and expression of retinoic acid receptors and epidermal growth factor receptor

    Directory of Open Access Journals (Sweden)

    Irwin Robert J

    2002-06-01

    Full Text Available Abstract Background Modulation of the expression of retinoic acid receptors (RAR α and γ in adult rat prostate by testosterone (T suggests that RAR signaling events might mediate some of the androgen effects on prostate cells. Method In this study, we examined the interactions between T and retinoic acid (RA in cell growth of human prostate carcinoma cells, LNCaP, and their relationship with the expression of RAR and epidermal growth factor receptor (EGF-R. Results Both T and RA, when administered alone, stimulated 3H-thymidine incorporation in LNCaP cells in a dose-dependent manner; the effect of each agent was reciprocally attenuated by the other agent. Testosterone treatment of LNCaP cells also resulted in dose dependent, biphasic increases in RAR α and γ mRNAs; increases paralleled that of 3H-thymidine incorporation and were attenuated by the presence of 100 nM RA. These results suggest a link between RAR signaling and the effect of T on LNCaP cell growth. Gel electrophoretic mobility shift assays revealed the presence of putative androgen responsive element (ARE in the promoter region of RAR α gene, suggesting that a direct AR-DNA interaction might mediate the effects of T on RAR α gene. Furthermore, treatment of LNCaP cells with 20 nM T resulted in an increase in EGF-R. In contrast, EGF-R was suppressed by 100 nM RA that also suppressed the effect of T. Conclusions Current results demonstrate interactions between T and RA in the expression of RARs and cell growth in LNCaP cells. The presence of putative ARE in the promoter of the RAR α gene suggests that AR-DNA interaction might mediate the effects of T on RAR α gene. The opposite effects of T and RA on the expression of RAR and EGF-R suggest that signal events of these receptors might be involved in the interaction between T and RA in the control of LNCaP cell growth.

  19. Androgen and retinoic acid interaction in LNCaP cells, effects on cell proliferation and expression of retinoic acid receptors and epidermal growth factor receptor

    International Nuclear Information System (INIS)

    Modulation of the expression of retinoic acid receptors (RAR) α and γ in adult rat prostate by testosterone (T) suggests that RAR signaling events might mediate some of the androgen effects on prostate cells. In this study, we examined the interactions between T and retinoic acid (RA) in cell growth of human prostate carcinoma cells, LNCaP, and their relationship with the expression of RAR and epidermal growth factor receptor (EGF-R). Both T and RA, when administered alone, stimulated 3H-thymidine incorporation in LNCaP cells in a dose-dependent manner; the effect of each agent was reciprocally attenuated by the other agent. Testosterone treatment of LNCaP cells also resulted in dose dependent, biphasic increases in RAR α and γ mRNAs; increases paralleled that of 3H-thymidine incorporation and were attenuated by the presence of 100 nM RA. These results suggest a link between RAR signaling and the effect of T on LNCaP cell growth. Gel electrophoretic mobility shift assays revealed the presence of putative androgen responsive element (ARE) in the promoter region of RAR α gene, suggesting that a direct AR-DNA interaction might mediate the effects of T on RAR α gene. Furthermore, treatment of LNCaP cells with 20 nM T resulted in an increase in EGF-R. In contrast, EGF-R was suppressed by 100 nM RA that also suppressed the effect of T. Current results demonstrate interactions between T and RA in the expression of RARs and cell growth in LNCaP cells. The presence of putative ARE in the promoter of the RAR α gene suggests that AR-DNA interaction might mediate the effects of T on RAR α gene. The opposite effects of T and RA on the expression of RAR and EGF-R suggest that signal events of these receptors might be involved in the interaction between T and RA in the control of LNCaP cell growth

  20. 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

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

    OpenAIRE

    Mahdi Behdani; Sirous Zeinali; Morteza Karimipour; Hossein Khanahmad; Nader Asadzadeh; Kayhan Azadmanesh; Negar Seyed; Seyed Farzad Baniahmad; Mahdi Habibi Anbouhi

    2012-01-01

    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 ...

  2. Antiepidermal Growth Factor Receptor Therapy in Squamous Cell Carcinoma of the Head and Neck

    Directory of Open Access Journals (Sweden)

    Walid Shaib

    2012-01-01

    Full Text Available Squamous cell carcinoma of head and neck (SCCHN is the most common neoplasm of the upper aerodigestive tract. In this paper, we attempt to summarize the role and applications of the epidermal growth factor receptor (EGFR inhibitors monoclonal antibodies (moAbs and tyrosine kinase inhibitors (TKIs locally advanced as well as metastatic SCCHN. Targeted therapy in SCCHN is now incorporated in the first-line regimes for advanced disease. Novel targeted agents, including the EGFR antibody, cetuximab, have been approved for use as single agents or in combination with radiation therapy or chemotherapy in treatment of recurrent metastatic or locally advanced SCCHN. Refractory mechanisms that bypass the pathway of EGFR inhibitors activity are identified explaining resistance to targeted therapy. Strategies of cotargeting EGFR and other pathways are under investigation. Examples of targeted therapy being used include mammalian target of rapamycin (mtor inhibitors, antivascular endothelial growth factor (VEGF moAb, and other inhibitors. We will be focusing our paper on the preclinical and clinical aspects of EGFR inhibition in SCCHN and touch upon other targeted therapies in application.

  3. Binding of epidermal growth factor to receptors in preparations of enriched porcine parietal cells and inhibition of aminopyrine uptake

    International Nuclear Information System (INIS)

    Preparations of isolated porcine gastric cells, enriched in parietal cells, were used to study binding of epidermal growth factor (EGF) to receptors and subsequent inhibition of (14C) aminopyrine uptake. EGF in concentrations from 10-10 to 10-7M inhibited aminopyrine uptake stimulated by 10-5M histamine with an IC50 of 3x10-10M. (125)EGF bound in a saturable and specific manner to sites on cells in preparations containing 40-90% parietal cells. Mean apparent dissociation constant for the sites was 1.6x10-9M, with an average number of approximately 20000 sites per cell. Endocytosis of ligand by parietal cells was limited, amounting to 10-20% of bound EGF after 1 h of incubation at 37oC. Occupation of a fraction of the receptors caused a maximal reduction by 40% of aminopyrine uptake in histamine-stimulated cells, suggesting the occurence of spare receptors. The results indicate the existence of specific receptors for EGF on porcine parietal cells exerting a regulatory influence on acid secretion. 28 refs., 3 figs., 1 tab

  4. siRNA epidermal growth factor receptor silencing in U251 glioma cells

    Institute of Scientific and Technical Information of China (English)

    Chunsheng Kang; Zhiyong Zhang; Zhifan Jia; Qiang Huang; Guangxiu Wang; Mingzhe Qiu; Peiyu Pu

    2008-01-01

    BACKGROUND: Dicer, a large multidomain ribonuclease, is responsible for processing double-stranded RNAs (dsRNAs) to 20-bp-long small interfering RNAs (siRNAs), which act as effectors during RNA interference (RNAi). OBJECTIVE: To observe the efficacy of siRNA cocktails generated by recombinant human Dicer on the down-regulation of epidermal growth factor receptor (EGFR) expression in human glioma cells. DESIGN, TIME AND SETTING: The following in vitro experiment was performed at the Department of Neurosurgery, Tianjin Medical University General Hospital and Laboratory of Neuro-Oncology, Tianjin Neurological Institute. MATERIALS: Mini-RNA isolation kit, human placenta complimentary DNA (cDNA) was produced by Tiangen Biotech (Beijing, China), human glioblastoma U251-MG cells were produced by the Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences. METHODS: A PCR product from the human EGFR, which corresponded to the tyrosine kinase domain of the 3'-end fragment, was used as the T7-promotor for in vitro transcription, siRNA cocktails were generated by in vitro dicing of double stranded RNA. A total of 500, 250 and 125 μg siRNA cocktails were transiently transfected into U251 glioma cells through the use of the GeneSilencer. MAIN OUTCOME MEASURE: Expression of EGFR was detected by real-time PCR. RESULTS: The total PCR product of the human EGFR, corresponding to the tyrosine kinase domain, is approximately 680 bp in length. The PCR transcriptants included GCC leader sequences and a T7 promoter sequence, with a fragment of EGFR cDNA at the center. The T7 promoter was prepared for in vitro transcription of dsRNA. After dicing for 24 hours, the 21-nt siRNA cocktails were verified by 4% agarose gel. The difference between threshold cycle of a sample assay and threshold cycle of the corresponding endogenous reference (△ Ct) among parental U251 cells and cells transfected with different doses of siRNA cocktails were determined to be 3.06, 7.35, and 10

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

    International Nuclear Information System (INIS)

    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: → Mechanical stretch augments insulin-induced VSMC proliferation via IGF-1 receptor. → Src/EGFR-mediated ERK and Akt phosphorylation are augmented in stretched VSMCs. → Similar to in vitro experiment, IGF-1 receptor is increased in hypertensive rats. → Results provide possible mechanisms of vascular remodeling in hypertension with DM.

  6. 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.

  7. Molecular phenotype predicts sensitivity of squamous cell carcinoma of the head and neck to epidermal growth factor receptor inhibition

    OpenAIRE

    Young, Natalie R.; LIU Jing; Pierce, Carolyn; Wei, Tai-Fen; Grushko, Tatyana; Olopade, Olufunmilayo I.; Liu, Wanqing; Shen, Christine; Seiwert, Tanguy Y.; Cohen, Ezra E.W.

    2012-01-01

    Despite nearly universal expression of the wild-type epidermal growth factor receptor (EGFR) and reproducible activity of EGFR inhibitors in patients with squamous cell carcinoma of the head and neck (SCCHN), the majority of patients will not have objective responses. The mechanisms of this intrinsic resistance are not well established. We hypothesized that sensitivity to EGFR inhibitors can be predicted based on the inhibitors’ effects on downstream signaling. Cell viability assays were used...

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

    DEFF Research Database (Denmark)

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

    2009-01-01

    elements in neoplastic cells and their microenvironment have recently been and are continuously developed including drugs inhibiting the angiogenic system. Angiogenic factor vascular endothelial growth factor (VEGF) and its receptor vascular endothelial growth factor receptor 2 (VEGFR2) seem to play key...... stained on whole tumour slides. Kaplan-Meier survival curves were generated to evaluate the significance of immunohistochemical VEGF-A and VEGFR2 expression for the prognosis. RESULTS: VEGF-A and VEGFR2 expression was observed in the majority of NSCLC patients. VEGF-A expression showed a correlation to...

  9. Mechanisms involved in PGE2-induced transactivation of the epidermal growth factor receptor in MH1C1 hepatocarcinoma cells

    Directory of Open Access Journals (Sweden)

    Tveteraas Ingun

    2012-09-01

    Full Text Available Abstract Background It is important to understand the mechanisms by which the cells integrate signals from different receptors. Several lines of evidence implicate epidermal growth factor (EGF receptor (EGFR in the pathophysiology of hepatocarcinomas. Data also suggest a role of prostaglandins in some of these tumours, through their receptors of the G protein-coupled receptor (GPCR family. In this study we have investigated mechanisms of interaction between signalling from prostaglandin receptors and EGFR in hepatocarcinoma cells. Methods The rat hepatocarcinoma cell line MH1C1 and normal rat hepatocytes in primary culture were stimulated with EGF or prostaglandin E2 (PGE2 and in some experiments also PGF2α. DNA synthesis was determined by incorporation of radiolabelled thymidine into DNA, phosphorylation of proteins in signalling pathways was assessed by Western blotting, mRNA expression of prostaglandin receptors was determined using qRT-PCR, accumulation of inositol phosphates was measured by incorporation of radiolabelled inositol, and cAMP was determined by radioimmunoassay. Results In the MH1C1 hepatocarcinoma cells, stimulation with PGE2 or PGF2α caused phosphorylation of the EGFR, Akt, and ERK, which could be blocked by the EGFR tyrosine kinase inhibitor gefitinib. This did not occur in primary hepatocytes. qRT-PCR revealed expression of EP1, EP4, and FP receptor mRNA in MH1C1 cells. PGE2 stimulated accumulation of inositol phosphates but not cAMP in these cells, suggesting signalling via PLCβ. While pretreatment with EP1 and EP4 receptor antagonists did not inhibit the effect of PGE2, pretreatment with an FP receptor antagonist blocked the phosphorylation of EGFR, Akt and ERK. Further studies suggested that the PGE2-induced signal was mediated via Ca2+ release and not PKC activation, and that it proceeded through Src and shedding of membrane-bound EGFR ligand precursors by proteinases of the ADAM family. Conclusion The results

  10. Distribution and number of epidermal growth factor receptors in skin is related to epithelial cell growth

    DEFF Research Database (Denmark)

    Green, M R; Basketter, D A; Couchman, J R;

    1983-01-01

    EGF. EGF receptors are detected on the epithelial cells overlying the basement membranes of the epidermis, sebaceous gland, and regions of the hair follicle all of which have proliferative capacity. In marked contrast, tissues which have started to differentiate and lost their growth potential, carry...... in the spatial and temporal control of epithelial proliferation....

  11. 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)

    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

  12. 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.

  13. Identification and characterization of receptors for granulocyte colony-stimulating factor on human placenta and trophoblastic cells

    Energy Technology Data Exchange (ETDEWEB)

    Uzumaki, Hiroya; Okabe, Tetsuro; Sasaki, Norio; Hagiwara, Koichi; Takaku, Fumimaro; Tobita, Masahito; Yasukawa, Kaoru (Univ. of Tokyo, Hongo (Japan)); Ito, Seiga (Kyowa Hakko Kogyo Co., Ltd., Machida, Tokyo (Japan)); Umezawa, Yoshimi (Juntendo Univ. School of Medicine, Hongo, Tokyo (Japan))

    1989-12-01

    Since radioiodination of human granulocyte colony-stimulating factor (G-CSF) is difficult, the authors synthesized a mutein of human G-CSF that retains full biological activity and receptor-binding capacity for at least 2 weeks after radioiodination. Receptors for human G-CSF were characterized in the plasma membrane fraction from the human term placenta (human placental membranes) and trophoblastic cells by using the {sup 125}I-labeled mutein of human G-CSF (KW-2228). The specific binding of {sup 125}I-labeled KW-2228 to placental membranes was pH-dependent, with maximal specific binding at pH 7.8; it increased linearly with protein to 3.7 mg of protein per ml and was both time- and temperature-dependent, with maximal binding at 4{degree}C after a 24-hr incubation. When the authors examined the ability of hematopoietic growth factors to inhibit {sup 125}I-labeled KW-2228 binding, they found that KW-2228 and intact human G-CSF ihibited {sup 125}I-labeled KW-2228 binding, whereas erythropoietin or granulocyte-macrophage colony-stimulating factor did not. Scatchard analysis revealed a single receptor type. The human G-CSF receptors on human placental membranes were shown to consist of two molecular species that could be specifically cross-linked to {sup 125}I-labeled KW-2228. Human trophoblastic cells, T3M-3, also possessed a single receptor for G-CSF. They have identified the receptor for human G-CSF on human placental membranes and trophoblastic cells.

  14. Identification and characterization of receptors for granulocyte colony-stimulating factor on human placenta and trophoblastic cells

    International Nuclear Information System (INIS)

    Since radioiodination of human granulocyte colony-stimulating factor (G-CSF) is difficult, the authors synthesized a mutein of human G-CSF that retains full biological activity and receptor-binding capacity for at least 2 weeks after radioiodination. Receptors for human G-CSF were characterized in the plasma membrane fraction from the human term placenta (human placental membranes) and trophoblastic cells by using the 125I-labeled mutein of human G-CSF (KW-2228). The specific binding of 125I-labeled KW-2228 to placental membranes was pH-dependent, with maximal specific binding at pH 7.8; it increased linearly with protein to 3.7 mg of protein per ml and was both time- and temperature-dependent, with maximal binding at 4 degree C after a 24-hr incubation. When the authors examined the ability of hematopoietic growth factors to inhibit 125I-labeled KW-2228 binding, they found that KW-2228 and intact human G-CSF ihibited 125I-labeled KW-2228 binding, whereas erythropoietin or granulocyte-macrophage colony-stimulating factor did not. Scatchard analysis revealed a single receptor type. The human G-CSF receptors on human placental membranes were shown to consist of two molecular species that could be specifically cross-linked to 125I-labeled KW-2228. Human trophoblastic cells, T3M-3, also possessed a single receptor for G-CSF. They have identified the receptor for human G-CSF on human placental membranes and trophoblastic cells

  15. The stem cell factor/c-kit receptor pathway enhances proliferation and invasion of pancreatic cancer cells

    Directory of Open Access Journals (Sweden)

    Okada Yuji

    2006-10-01

    Full Text Available Abstract Background The transmembrane protein c-kit is a receptor tyrosine kinase (KIT and KIT is expressed in solid tumors and hematological malignancies such as gastrointestinal stromal tumor (GIST, small-cell lung cancer and chronic myelogenous leukemia (CML. KIT plays a critical role in cell proliferation and differentiation and represents a logical therapeutic target in GIST and CML. In pancreatic cancer, c-kit expression has been observed by immunohistochemical techniques. In this study, we examined the influence of c-kit expression on proliferation and invasion using five pancreatic cancer cell lines. In addition, the inhibitory effect of imatinib mesylate on stem cell factor (SCF-induced proliferation and invasion was evaluated. Finally, we also analyzed KIT and SCF expression in pancreatic cancer tissues using immunohistochemistry and correlated the results with clinical features. Results RT-PCR revealed that two pancreatic cancer cell lines, PANC-1 and SW1990, expressed c-kit mRNA. By Western blot analysis, c-kit protein was also present in those lines. In KIT-positive pancreatic cancer cell lines, proliferation and invasion were significantly enhanced by addition of SCF. In contrast, SCF did not enhance proliferation and invasion in the three KIT-negative lines (BxPC-3, Capan-2 and MIA PaCa-2. 5 μM imatinib mesylate significantly inhibited SCF-enhanced proliferation to the same extent compared with the control. Similarly, SCF-enhanced invasive ability was significantly inhibited by 5 μM imatinib mesylate. KIT was expressed in 16 of 42 clinical specimens by immunohistochemistry, and KIT expression was significantly related to venous system invasion. Furthermore, patients expressing both KIT and SCF had a somewhat lower survival. Conclusion Our results demonstrated that the SCF-KIT pathway enhanced the proliferation and invasiveness in KIT-positive pancreatic cancer cell lines and that the enhanced proliferation and invasion were

  16. Label-free and dynamic evaluation of cell-surface epidermal growth factor receptor expression via an electrochemiluminescence cytosensor.

    Science.gov (United States)

    Qiu, Youyi; Wen, Qingqing; Zhang, Lin; Yang, Peihui

    2016-04-01

    A label-free electrochemiluminescence (ECL) cytosensor was developed for dynamically evaluating of epidermal growth factor receptor (EGFR) expression on MCF-7 cancer cells based on the specific recognition of epidermal growth factor (EGF) with its receptor (EGFR). EGF-cytosensor was fabricated by in-situ electro-polymerization of polyaniline as substrate, using CdS quantum dots (CdS QDs) as ECL probe and gold nanoparticles (AuNPs) as a carrier for loading of EGF. AuNPs and CdS QDs were jointly attached on polyaniline surface to provide a sensitive and stable sensing interface, as well as a simple and label-free mode for ECL assay. Electron microscopy, atomic force microscopy (AFM) and electrochemical methods were employed to characterize the multilayer construction process of the sensing interface. The proposed EGF-cytosensor exhibited excellent analytical performance for MCF-7 cancer cells, ranging from 12 to 1.2 × 10(6) cells mL(-1), with a low detection limit of 12 cells mL(-1). Also, it was successfully applied in evaluating EGFR expression of cells surface, which was stimulated by some inhibitors or activator, and the results were confirmed by using flow cytometry and laser scanning confocal microscopy analysis. The proposed ECL cytosensor has potential applications in monitoring the dynamic variation of receptor molecules expression on cell surfaces in response to external stimulation by drugs and screening anti-cancer therapeutic agents. PMID:26838410

  17. Identification and characterization of receptors for granulocyte colony-stimulating factor on human placenta and trophoblastic cells.

    OpenAIRE

    Uzumaki, H; Okabe, T.; Sasaki, N; Hagiwara, K.; Takaku, F; Tobita, M.; Yasukawa, K; Ito, S.; Umezawa, Y.

    1989-01-01

    Since radioiodination of human granulocyte colony-stimulating factor (G-CSF) is difficult, we synthesized a mutein of human G-CSF that retains full biological activity and receptor-binding capacity for at least 2 weeks after radioiodination. Receptors for human G-CSF were characterized in the plasma membrane fraction from the human term placenta (human placental membranes) and trophoblastic cells by using the 125I-labeled mutein of human G-CSF (KW-2228). The specific binding of 125I-labeled K...

  18. Activation of corticotropin releasing factor receptors up regulates collagen production by hepatic stellate cells via promoting p300 expression.

    Science.gov (United States)

    Wang, Changzhen; Yang, Shan; Huang, Jingjing; Chen, Songlin; Li, Yuan; Li, Quanqiang

    2016-05-01

    Liver fibrosis is characterized with the over expression and excessive accumulation of extracellular matrix proteins, including collagens. The causative factors in the over production of collagens are not fully understood. This study aims to test a hypothesis that activation of corticotropin releasing factor receptors up regulates the expression of collagen in hepatic stellate cells. In this study, human hepatic stellate cell line, LX-2 cells were cultured. Expression of collagens by LX-2 cells was assessed by real time RT-PCR, Western blotting. The results showed that, upon exposure to urocortin in the culture, LX-2 cells (a human hepatic stellate cell line) increased the expression of collagen IV (Col4) markedly. The exposure to urocortin also enhanced the levels of pTip60, H3K9, RNA polymerase II and forkhead box protein 3 at the collagen promoter locus as well as increase in the expression of Col4 mRNA and protein in the cells. Blocking p300 efficiently suppressed the urocortin-induced Col4 expression in LX-2 cells and unveiled an apoptosis-inducing effect of urocortin. In conclusion, activation of CRF receptors is capable of enforcing the production of Col4 by LX-2 cells via up regulating the p300 pathway, which may contribute to the development of liver fibrosis. PMID:26756093

  19. Contributions of the Epidermal Growth Factor Receptor to Acquisition of Platinum Resistance in Ovarian Cancer Cells

    OpenAIRE

    Granados, Michaela L.; Hudson, Laurie G.; Samudio-Ruiz, Sabrina L.

    2015-01-01

    Acquisition of platinum resistance following first line platinum/taxane therapy is commonly observed in ovarian cancer patients and prevents clinical effectiveness. There are few options to prevent platinum resistance; however, demethylating agents have been shown to resensitize patients to platinum therapy thereby demonstrating that DNA methylation is a critical contributor to the development of platinum resistance. We previously reported the Epidermal Growth Factor Receptor (EGFR) is a nove...

  20. AZD9291 in epidermal growth factor receptor inhibitor—resistant non-small-cell lung cancer

    Science.gov (United States)

    2016-01-01

    Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) in advanced EGFR mutant non-small cell lung cancer have an objective response rate (ORR) of approximately 60–70% and a median progression free-survival (PFS) of approximately 10-13 months. Studies of tumor biopsies performed after progression on EGFR TKI revealed that 50-60% of EGFR mutant NSCLC developed an EGFR exon 20 T790M mutation as a mechanism of acquired resistance. AZD9291 is a third generation irreversible EGFR TKI with activity against the activating EGFR mutation, the T790M acquired resistance mutation, and relative sparing of the wild-type EGFR. AZD9291 was investigated in a phase I trial with expansion cohorts in patients with disease progression after EGFR TKI. Patients with and without detectable T790M mutations were enrolled in the trial. The ORR in patients with centrally confirmed and without detectable T790M mutations was 61% (95% CI, 52–70%) and 21% (95% CI, 12–34%), respectively. The PFS observed in patients with centrally confirmed and without detectable T790M mutations was 9.6 months (95% CI, 8.3 to not reached) and 2.8 months (95% CI, 2.1–4.3 months), respectively. At the dose for further investigation, 80 mg daily, the rate of all grade 3-5 drug related adverse events was 11%, and the rates of grade 3 diarrhea and rash were 1% and 0%, respectively. The identification of the T790M resistance mutation and the subsequent development of an agent against the mechanism of resistance provide a template for future drug development for acquired resistance to targeted therapy. PMID:26958499

  1. AZD9291 in epidermal growth factor receptor inhibitor-resistant non-small-cell lung cancer.

    Science.gov (United States)

    Stinchcombe, Thomas E

    2016-02-01

    Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) in advanced EGFR mutant non-small cell lung cancer have an objective response rate (ORR) of approximately 60-70% and a median progression free-survival (PFS) of approximately 10-13 months. Studies of tumor biopsies performed after progression on EGFR TKI revealed that 50-60% of EGFR mutant NSCLC developed an EGFR exon 20 T790M mutation as a mechanism of acquired resistance. AZD9291 is a third generation irreversible EGFR TKI with activity against the activating EGFR mutation, the T790M acquired resistance mutation, and relative sparing of the wild-type EGFR. AZD9291 was investigated in a phase I trial with expansion cohorts in patients with disease progression after EGFR TKI. Patients with and without detectable T790M mutations were enrolled in the trial. The ORR in patients with centrally confirmed and without detectable T790M mutations was 61% (95% CI, 52-70%) and 21% (95% CI, 12-34%), respectively. The PFS observed in patients with centrally confirmed and without detectable T790M mutations was 9.6 months (95% CI, 8.3 to not reached) and 2.8 months (95% CI, 2.1-4.3 months), respectively. At the dose for further investigation, 80 mg daily, the rate of all grade 3-5 drug related adverse events was 11%, and the rates of grade 3 diarrhea and rash were 1% and 0%, respectively. The identification of the T790M resistance mutation and the subsequent development of an agent against the mechanism of resistance provide a template for future drug development for acquired resistance to targeted therapy. PMID:26958499

  2. MUC4 potentiates invasion and metastasis of pancreatic cancer cells through stabilization of fibroblast growth factor receptor 1

    OpenAIRE

    Rachagani, Satyanarayana; Muzafar A Macha; Moorthy P Ponnusamy; Haridas, Dhanya; Kaur, Sukhwinder; Jain, Maneesh; Batra, Surinder K.

    2012-01-01

    MUC4 is a type-1 transmembrane mucin differentially expressed in multiple cancers and has previously been shown to potentiate progression and metastasis of pancreatic cancer. In this study, we investigated the molecular mechanisms associated with the MUC4-induced invasion and metastasis in pancreatic cancer. Stable silencing of MUC4 in multiple pancreatic cancer cells resulted in the downregulation of N-cadherin and its interacting partner fibroblast growth factor receptor 1 (FGFR1) through d...

  3. Prognostic impact of epidermal growth factor receptor on clear cell renal cell carcinoma: Does it change with different expression patterns?

    Directory of Open Access Journals (Sweden)

    Duygu Kankaya

    2016-01-01

    Full Text Available Introduction: The aim of this study was to assess whether epidermal growth factor receptor (EGFR overexpression was a significant prognostic factor in clear cell renal cell carcinoma (CRCC and whether its prognostic significance was affected by immunohistochemical expression patterns. Materials and Methods: Immunohistochemistry was performed on 100 cases of CRCC using an antibody against EGFR. Tumors were grouped by nuclear grade (NG as low-NG (NG1, 2 or high NG (NG3, 4, and by pathological stage as localized (pT1, 2, or locally invasive (pT3, 4. Clinical disease was grouped by clinical stage as early stage (stage I, II, or late stage (stage III, IV. Evaluation of the EGFR overexpression was based on cytoplasmic (EGFR Cyt , and membranous (EGFR Mem staining. Results: EGFR Cyt correlated with high NG (P = 0.001, lymphovascular invasion (P = 0.028, regional lymph node involvement (P = 0.027, metastasis (P = 0.001, late stage (P = 0.003, cancer-specific death (P = 0.036, and was a predictor for disease-specific survival (P = 0.012 whereas EGFR Mem correlated with only local invasion (P = 0.021 and perirenal invasion (P = 0.009 and did not show any correlation with cancer-specific death or disease specific survival. Conclusion: Our findings suggest that EGFR overexpression is an important prognostic factor in CRCC, and its prognostic value differs significantly with respect to the location of EGFR immunostaining. This prognostic difference may give direction on the management and treatment of CRCC patients.

  4. Tumor necrosis factor receptor superfamily member 9 is upregulated in the endothelium and tumor cells in melanoma brain metastasis

    Directory of Open Access Journals (Sweden)

    Patrick N Harter

    2014-12-01

    Full Text Available Aim: The cytokine receptor tumor necrosis factor receptor superfamily member 9 (TNFRSF9 is mainly considered to be a co-stimulatory activation marker in hematopoietic cells. Several preclinical models have shown a dramatic beneficial effect of treatment approaches targeting TNFRSF9 with agonistic antibodies. However, preliminary clinical phase I/II studies were stopped after the occurrence of several severe deleterious side effects. In a previous study, it was demonstrated that TNFRSF9 was strongly expressed by reactive astrocytes in primary central nervous system (CNS tumors, but was largely absent from tumor or inflammatory cells. The aim of the present study was to address the cellular source of TNFRSF9 expression in the setting of human melanoma brain metastasis, a highly immunogenic tumor with a prominent tropism to the CNS. Methods: Melanoma brain metastasis was analyzed in a cohort of 78 patients by immunohistochemistry for TNFRSF9 and its expression was correlated with clinicopathological parameters including sex, age, survival, tumor size, number of tumor spots, and BRAF V600E expression status. Results: Tumor necrosis factor receptor superfamily member 9 was frequently expressed independently on both melanoma and endothelial cells. In addition, TNFRSF9 was also present on smooth muscle cells of larger vessels and on a subset of lymphomonocytic tumor infiltrates. No association between TNFRSF9 expression and patient survival or other clinicopathological parameters was seen. Of note, several cases showed a gradual increase in TNFRSF9 expression on tumor cells with increasing distance from blood vessels, an observation that might be linked to hypoxia-driven TNFRSF9 expression in tumor cells. Conclusion: The findings indicate that the cellular source of TNFRSF9 in melanoma brain metastasis largely exceeds the lymphomonocytic pool, and therefore further careful (re- assessment of potential TNFRSF9 functions in cell types other than

  5. MAPKK-dependent growth factor-induced upregulation of P2Y2 receptors in vascular smooth muscle cells

    DEFF Research Database (Denmark)

    Hou, M; Möller, S; Edvinsson, L;

    1999-01-01

    The ATP- and UTP-sensitive P2Y2 receptor which mediates both contractile and mitogenic effects has recently been shown to be upregulated in the synthetic phenotype of the vascular smooth muscle cell (VSMC). Using a competitive RT-PCR we demonstrate that the P2Y2 receptor mRNA is increased by fetal...... calf serum and other growth factors in a MAPKK-dependent way. This was confirmed at the functional level by examining UTP-stimulated release of intracellular Ca2+. Furthermore, the P2Y2 receptor mRNA is positively autoregulated by ATP and the mRNA is rapidly degraded with only 26% remaining after 1 h...

  6. Steroid Receptor Coactivator-3 Regulates Glucose Metabolism in Bladder Cancer Cells through Coactivation of Hypoxia Inducible Factor 1α*

    Science.gov (United States)

    Zhao, Wei; Chang, Cunjie; Cui, Yangyan; Zhao, Xiaozhi; Yang, Jun; Shen, Lan; Zhou, Ji; Hou, Zhibo; Zhang, Zhen; Ye, Changxiao; Hasenmayer, Donald; Perkins, Robert; Huang, Xiaojing; Yao, Xin; Yu, Like; Huang, Ruimin; Zhang, Dianzheng; Guo, Hongqian; Yan, Jun

    2014-01-01

    Cancer cell proliferation is a metabolically demanding process, requiring high glycolysis, which is known as “Warburg effect,” to support anabolic growth. Steroid receptor coactivator-3 (SRC-3), a steroid receptor coactivator, is overexpressed and/or amplified in multiple cancer types, including non-steroid targeted cancers, such as urinary bladder cancer (UBC). However, whether SRC-3 regulates the metabolic reprogramming for cancer cell growth is unknown. Here, we reported that overexpression of SRC-3 accelerated UBC cell growth, accompanied by the increased expression of genes involved in glycolysis. Knockdown of SRC-3 reduced the UBC cell glycolytic rate under hypoxia, decreased tumor growth in nude mice, with reduction of proliferating cell nuclear antigen and lactate dehydrogenase expression levels. We further revealed that SRC-3 could interact with hypoxia inducible factor 1α (HIF1α), which is a key transcription factor required for glycolysis, and coactivate its transcriptional activity. SRC-3 was recruited to the promoters of HIF1α-target genes, such as glut1 and pgk1. The positive correlation of expression levels between SRC-3 and Glut1 proteins was demonstrated in human UBC patient samples. Inhibition of glycolysis through targeting HK2 or LDHA decelerated SRC-3 overexpression-induced cell growth. In summary, overexpression of SRC-3 promoted glycolysis in bladder cancer cells through HIF1α to facilitate tumorigenesis, which may be an intriguing drug target for bladder cancer therapy. PMID:24584933

  7. Lithium, but Not Fluoxetine or the Corticotropin-Releasing Factor Receptor 1 Receptor Antagonist R121919, Increases Cell Proliferation in the Adult Dentate Gyrus

    OpenAIRE

    Hanson, Nicola D; Nemeroff, Charles B.; Owens, Michael J.

    2011-01-01

    Several antidepressant drugs have previously been reported to increase neurogenesis in the dentate gyrus of the hippocampus in laboratory animals. We found no effect of the selective serotonin reuptake inhibitor fluoxetine or the corticotropin-releasing factor receptor 1 antagonist R121919 [3-[6-(dimethylamino)-4-methylpyridin-3-yl]-2,5-dimethyl-N,N-dipropyl-1H-pyrazolo[1,5-a]pyrimidin-8-ium-7-amine] on the rate of cell proliferation or hippocampal brain-derived neurotrophic factor (BDNF) mRN...

  8. Epidermal growth factor receptor signalling in human breast cancer cells operates parallel to estrogen receptor α signalling and results in tamoxifen insensitive proliferation

    International Nuclear Information System (INIS)

    Tamoxifen resistance is a major problem in the treatment of estrogen receptor (ER) α -positive breast cancer patients. Although the mechanisms behind tamoxifen resistance are still not completely understood, clinical data suggests that increased expression of receptor tyrosine kinases is involved. Here, we studied the estrogen and anti-estrogen sensitivity of human breast cancer MCF7 cells that have a moderate, retroviral-mediated, ectopic expression of epidermal growth factor receptor (MCF7-EGFR). Proliferation of MCF7-EGFR and parental cells was induced by 17β-estradiol (E2), epidermal growth factor (EGF) or a combination of these. Inhibition of proliferation under these conditions was investigated with 4-hydroxy-tamoxifen (TAM) or fulvestrant at 10-12 to 10-6 M. Cells were lysed at different time points to determine the phosphorylation status of EGFR, MAPK1/3, AKT and the expression of ERα. Knockdown of target genes was established using smartpool siRNAs. Transcriptomics analysis was done 6 hr after stimulation with growth factors using Affymetrix HG-U133 PM array plates. While proliferation of parental MCF7 cells could only be induced by E2, proliferation of MCF7-EGFR cells could be induced by either E2 or EGF. Treatment with TAM or fulvestrant did significantly inhibit proliferation of MCF7-EGFR cells stimulated with E2 alone. EGF treatment of E2/TAM treated cells led to a marked cell proliferation thereby overruling the anti-estrogen-mediated inhibition of cell proliferation. Under these conditions, TAM however did still inhibit ERα- mediated transcription. While siRNA-mediated knock-down of EGFR inhibited the EGF- driven proliferation under TAM/E2/EGF condition, knock down of ERα did not. The TAM resistant cell proliferation mediated by the conditional EGFR-signaling may be dependent on the PI3K/Akt pathway but not the MEK/MAPK pathway, since a MEK inhibitor (U0126), did not block the proliferation. Transcriptomic analysis under the various E2/TAM

  9. Soluble perlecan domain i enhances vascular endothelial growth factor-165 activity and receptor phosphorylation in human bone marrow endothelial cells

    Directory of Open Access Journals (Sweden)

    Gomes Ronald R

    2010-11-01

    Full Text Available Abstract Background Immobilized recombinant perlecan domain I (PlnDI binds and modulates the activity of heparin-binding growth factors, in vitro. However, activities for PlnDI, in solution, have not been reported. In this study, we assessed the ability of soluble forms to modulate vascular endothelial growth factor-165 (VEGF165 enhanced capillary tube-like formation, and VEGF receptor-2 phosphorylation of human bone marrow endothelial cells, in vitro. Results In solution, PlnDI binds VEGF165 in a heparan sulfate and pH dependent manner. Capillary tube-like formation is enhanced by exogenous PlnDI; however, PlnDI/VEGF165 mixtures combine to enhance formation beyond that stimulated by either PlnDI or VEGF165 alone. PlnDI also stimulates VEGF receptor-2 phosphorylation, and mixtures of PlnDI/VEGF165 reduce the time required for peak VEGF receptor-2 phosphorylation (Tyr-951, and increase Akt phosphorylation. PlnDI binds both immobilized neuropilin-1 and VEGF receptor-2, but has a greater affinity for neuropilin-1. PlnDI binding to neuropilin-1, but not to VEGF receptor-2 is dependent upon the heparan sulfate chains adorning PlnDI. Interestingly, the presence of VEGF165 but not VEGF121 significantly enhances PlnDI binding to Neuropilin-1 and VEGF receptor-2. Conclusions Our observations suggest soluble forms of PlnDI are biologically active. Moreover, PlnDI heparan sulfate chains alone or together with VEGF165 can enhance VEGFR-2 signaling and angiogenic events, in vitro. We propose PlnDI liberated during basement membrane or extracellular matrix turnover may have similar activities, in vivo.

  10. miR-143 suppresses the proliferation of NSCLC cells by inhibiting the epidermal growth factor receptor

    Science.gov (United States)

    Zhang, Hong-Bo; Sun, Li-Chao; Ling, Lan; Cong, Lu-Hong; Lian, Rui

    2016-01-01

    MicroRNAs (miRs) regulate the proliferation and metastasis of numerous cancer cell types. It was previously reported that miR-143 levels were downregulated in non-small cell lung cancer (NSCLC) tissues and cell lines, and that the migration and invasion of NSCLC cells was inhibited upon suppression of cell proliferation and colony formation by the upregulation of miR-143. Epidermal growth factor receptor (EGFR), which is a vital factor in the promotion of cancer cell proliferation and has been investigated as a potential focus in cancer therapy, has been reported to be a possible target of miR-143. The present study aimed to investigate the role of miR-143 in NSCLC using NSCLC cell lines and primary cells from NSCLC patients. NSCLC cells were co-transfected with EGFR and miR-143, and the mRNA and protein expression of EGFR were analyzed. Furthermore, the activity of the transfected cancer cells with regard to colony formation, migration, invasion and apoptosis were evaluated. The levels of miR-143 were decreased in the NSCLC cell lines and primary cells from patients with NSCLC compared with the controls. Following transfection with miR-143, the ability of NSCLC cells to proliferate, form colonies, migrate and invade was inhibited. Similarly, knockdown of EGFR led to the suppression of NSCLC cell proliferation. The mRNA and protein expression levels of EGFR were significantly reduced following miR-143 overexpression, and the level of miR-143 was inversely correlated with that of EGFR in NSCLC cells. The results of the present study demonstrated that miR-143 was able to suppress NSCLC cell proliferation and invasion by inhibiting the effects of EGFR, suggesting that EGFR may be considered a potential target for NSCLC therapy. PMID:27602093

  11. Phenytoin enhances the phosphorylation of epidermal growth factor receptor and fibroblast growth factor receptor in the subventricular zone and promotes the proliferation of neural precursor cells and oligodendrocyte differentiation.

    Science.gov (United States)

    Galvez-Contreras, Alma Y; Gonzalez-Castaneda, Rocio E; Campos-Ordonez, Tania; Luquin, Sonia; Gonzalez-Perez, Oscar

    2016-01-01

    Phenytoin is a widely used antiepileptic drug that induces cell proliferation in several tissues, such as heart, bone, skin, oral mucosa and neural precursors. Some of these effects are mediated via fibroblast growth factor receptor (FGFR) and epidermal growth factor receptor (EGFR). These receptors are strongly expressed in the adult ventricular-subventricular zone (V-SVZ), the main neurogenic niche in the adult brain. The aim of this study was to determine the cell lineage and cell fate of V-SVZ neural progenitors expanded by phenytoin, as well as the effects of this drug on EGFR/FGFR phosphorylation. Male BALB/C mice received 10 mg/kg phenytoin by oral cannula for 30 days. We analysed the proliferation of V-SVZ neural progenitors by immunohistochemistry and western blot. Our findings indicate that phenytoin enhanced twofold the phosphorylation of EGFR and FGFR in the V-SVZ, increased the number of bromodeoxyuridine (BrdU)+/Sox2+ and BrdU+/doublecortin+ cells in the V-SVZ, and expanded the population of Olig2-expressing cells around the lateral ventricles. After phenytoin removal, a large number of BrdU+/Receptor interacting protein (RIP)+ cells were observed in the olfactory bulb. In conclusion, phenytoin enhanced the phosphorylation of FGFR and EGFR, and promoted the expression of neural precursor markers in the V-SVZ. In parallel, the number of oligodendrocytes increased significantly after phenytoin removal. PMID:26370587

  12. 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.; Andersen, J.; Heilmann, C. J.; Muller, Klaus; Andreassen, B U; Pærregaard, A; Michaelsen, K F; Andersen, J; Heilmann, C J; Müller, K

    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, and...

  13. Tensile force on human macrophage cells promotes osteoclastogenesis through receptor activator of nuclear factor κB ligand induction.

    Science.gov (United States)

    Kao, Chia-Tze; Huang, Tsui-Hsien; Fang, Hsin-Yuan; Chen, Yi-Wen; Chien, Chien-Fang; Shie, Ming-You; Yeh, Chia-Hung

    2016-07-01

    Little is known about the effects of tensile forces on osteoclastogenesis by human monocytes in the absence of mechanosensitive cells, including osteoblasts and fibroblasts. In this study we consider the effects of tensile force on osteoclastogenesis in human monocytes. The cells were treated with receptor activator of nuclear factor κB ligand (RANKL) to promote osteoclastogenesis. Then,expression and secretion of cathepsin K were examined. RANKL and the formation of osteoclasts during the osteoclast differentiation process under continual tensile stress were evaluated by Western blot. It was also found that -100 kPa or lower induces RANKL-enhanced tartrate-resistant acid phosphatase activity in a dose-dependent manner. Furthermore, an increased tensile force raises the expression and secretion of cathepsin K elevated by RANKL, and is concurrent with the increase of TNF-receptor-associated factor 6 induction and nuclear factor κB activation. Overall, the current report demonstrates that tensile force reinforces RANKL-induced osteoclastogenesis by retarding osteoclast differentiation. The tensile force is able to modify every cell through dose-dependent in vitro RANKL-mediated osteoclastogenesis, affecting the fusion of preosteoclasts and function of osteoclasts. However, tensile force increased TNF-receptor-associated factor 6 expression. These results are in vitro findings and were obtained under a condition of tensile force. The current results help us to better understand the cellular roles of human macrophage populations in osteoclastogenesis as well as in alveolar bone remodeling when there is tensile stress. PMID:26204845

  14. Retinoic Acid Receptors Control Spermatogonia Cell-Fate and Induce Expression of the SALL4A Transcription Factor.

    Directory of Open Access Journals (Sweden)

    Aurore Gely-Pernot

    2015-10-01

    Full Text Available All-trans retinoic acid (ATRA is instrumental to male germ cell differentiation, but its mechanism of action remains elusive. To address this question, we have analyzed the phenotypes of mice lacking, in spermatogonia, all rexinoid receptors (RXRA, RXRB and RXRG or all ATRA receptors (RARA, RARB and RARG. We demonstrate that the combined ablation of RXRA and RXRB in spermatogonia recapitulates the set of defects observed both upon ablation of RAR in spermatogonia. We also show that ATRA activates RAR and RXR bound to a conserved regulatory region to increase expression of the SALL4A transcription factor in spermatogonia. Our results reveal that this major pluripotency gene is a target of ATRA signaling and that RAR/RXR heterodimers are the functional units driving its expression in spermatogonia. They add to the mechanisms through which ATRA promote expression of the KIT tyrosine kinase receptor to trigger a critical step in spermatogonia differentiation. Importantly, they indicate also that meiosis eventually occurs in the absence of a RAR/RXR pathway within germ cells and suggest that instructing this process is either ATRA-independent or requires an ATRA signal originating from Sertoli cells.

  15. The P2RY2 Receptor Induces Carcinoma Cell Migration and EMT Through Cross-Talk With Epidermal Growth Factor Receptor.

    Science.gov (United States)

    Martínez-Ramírez, A S; Garay, E; García-Carrancá, A; Vázquez-Cuevas, F G

    2016-04-01

    Extracellular nucleotides are signaling elements present in the tumor microenvironment; however, their role in tumor growth is not completely understood. In the present study, we asked whether nucleotides regulate cell migration in ovarian carcinoma-derived cells. We observed that 100 μM UTP induced migration in SKOV-3 cells (1.57 ± 0.08 fold over basal), and RT-PCR showed expression of transcripts for the P2RY2 and P2RY4 receptors. Knockdown of P2RY2 expression in SKOV-3 cells (P2RY2-KD) abolished the UTP-induced migration. The mechanism activated by UTP to induce migration involves transactivation of the epidermal growth factor receptor (EGFR) since we observed that the EGFR kinase inhibitor AG1478 and the PI3K inhibitor Wortmannin inhibit this response (to 0.76 ± 0.23 and 0.46 ± 0.14 relative to the control, respectively). In agreement with these observations, UTP was able to modify the phosphorylation state of the EGFR; likewise, the induction of ERK1/2 phosphorylation promoted by UTP was abolished by a 30-60 min treatment with AG1478. Our data also suggested that the enhanced cell migration involves the epithelium to mesenchymal transition (EMT) process, since a 12 h stimulation of SKOV-3 cells with 100 μM UTP showed an increase in vimentin and SNAIL protein levels (459.8 ± 132.4% over basal for SNAIL). Interestingly, treatment with apyrase (10 U/mL) reduces the migration of control cells and induces a considerable enrichment of E-cadherin in the cell-cell contacts, favoring an epithelial phenotype and strongly suggesting that the nucleotides released by tumor cells and acting through the P2RY2 receptor are potential regulators of invasiveness. J. Cell. Biochem. 117: 1016-1026, 2016. © 2015 Wiley Periodicals, Inc. PMID:26443721

  16. Modulation of estrogen and epidermal growth factor receptors by rosemary extract in breast cancer cells.

    Science.gov (United States)

    González-Vallinas, Margarita; Molina, Susana; Vicente, Gonzalo; Sánchez-Martínez, Ruth; Vargas, Teodoro; García-Risco, Mónica R; Fornari, Tiziana; Reglero, Guillermo; Ramírez de Molina, Ana

    2014-06-01

    Breast cancer is the leading cause of cancer-related mortality among females worldwide, and therefore the development of new therapeutic approaches is still needed. Rosemary (Rosmarinus officinalis L.) extract possesses antitumor properties against tumor cells from several organs, including breast. However, in order to apply it as a complementary therapeutic agent in breast cancer, more information is needed regarding the sensitivity of the different breast tumor subtypes and its effect in combination with the currently used chemotherapy. Here, we analyzed the antitumor activities of a supercritical fluid rosemary extract (SFRE) in different breast cancer cells, and used a genomic approach to explore its effect on the modulation of ER-α and HER2 signaling pathways, the most important mitogen pathways related to breast cancer progression. We found that SFRE exerts antitumor activity against breast cancer cells from different tumor subtypes and the downregulation of ER-α and HER2 receptors by SFRE might be involved in its antitumor effect against estrogen-dependent (ER+) and HER2 overexpressing (HER2+) breast cancer subtypes. Moreover, SFRE significantly enhanced the effect of breast cancer chemotherapy (tamoxifen, trastuzumab, and paclitaxel). Overall, our results support the potential utility of SFRE as a complementary approach in breast cancer therapy. PMID:24615943

  17. Conserved roles of fibroblast growth factor receptor 2 signaling in the regulation of inner cell mass development in bovine blastocysts.

    Science.gov (United States)

    Akizawa, Hiroki; Nagatomo, Hiroaki; Odagiri, Haruka; Kohri, Nanami; Yamauchi, Nobuhiko; Yanagawa, Yojiro; Nagano, Masashi; Takahashi, Masashi; Kawahara, Manabu

    2016-06-01

    A common process during preimplantation mammalian development is blastocyst formation, which utilizes signaling through fibroblast growth factor receptor 2 (FGFR2), yet the mechanisms through which FGFR2 signaling affect preimplantation development in bovine embryos remain incompletely understood. Here, we used RNA-interference to investigate the in vitro development, the frequency of blastomere apoptosis, and the mRNA expression of developmental marker genes in FGF receptor 2-knockdown (FGFR2-KD) bovine embryos. A reduction in FGFR2 mRNA did not affect preimplantation development or the frequency of apoptotic blastomeres, but did enhanced proliferation of the inner cell mass in blastocysts (P cattle. Mol. Reprod. Dev. 83: 516-525, 2016. © 2016 Wiley Periodicals, Inc. PMID:27060901

  18. Growth inhibition of thyroid follicular cell-derived cancers by the opioid growth factor (OGF - opioid growth factor receptor (OGFr axis

    Directory of Open Access Journals (Sweden)

    Donahue Renee N

    2009-10-01

    Full Text Available Abstract Background Carcinoma of the thyroid gland is an uncommon cancer, but the most frequent malignancy of the endocrine system. Most thyroid cancers are derived from the follicular cell. Follicular carcinoma (FTC is considered more malignant than papillary thyroid carcinoma (PTC, and anaplastic thyroid cancer (ATC is one of the most lethal human cancers. Opioid Growth Factor (OGF; chemical term - [Met5]-enkephalin and its receptor, OGFr, form an inhibitory axis regulating cell proliferation. Both the peptide and receptor have been detected in a wide variety of cancers, and OGF is currently used clinically as a biotherapy for some non-thyroid neoplasias. This study addressed the question of whether the OGF-OGFr axis is present and functional in human thyroid follicular cell - derived cancer. Methods Utilizing human ATC (KAT-18, PTC (KTC-1, and FTC (WRO 82-1 cell lines, immunohistochemistry was employed to ascertain the presence and location of OGF and OGFr. The growth characteristics in the presence of OGF or the opioid antagonist naltrexone (NTX, and the specificity of opioid peptides for proliferation of ATC, were established in KAT-18 cells. Dependence on peptide and receptor were investigated using neutralization studies with antibodies and siRNA experiments, respectively. The mechanism of peptide action on DNA synthesis and cell survival was ascertained. The ubiquity of the OGF-OGFr axis in thyroid follicular cell-derived cancer was assessed in KTC-1 (PTC and WRO 82-1 (FTC tumor cells. Results OGF and OGFr were present in KAT-18 cells. Concentrations of 10-6 M OGF inhibited cell replication up to 30%, whereas NTX increased cell growth up to 35% relative to cultures treated with sterile water. OGF treatment reduced cell number by as much as 38% in KAT-18 ATC in a dose-dependent and receptor-mediated manner. OGF antibodies neutralized the inhibitory effects of OGF, and siRNA knockdown of OGFr negated growth inhibition by OGF. Cell survival

  19. The Frequency of Epidermal Growth Factor Receptor Mutation of Nonsmall Cell Lung Cancer according to the Underlying Pulmonary Diseases

    Directory of Open Access Journals (Sweden)

    Kazuhiro Usui

    2011-01-01

    Full Text Available Background. Although epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs are effective in patients with nonsmall cell lung cancer with epidermal growth factor receptor (EGFR mutation, EGFR-TKIs have a risk of inducing fatal interstitial lung disease (ILD. The selection of chemotherapy based on the EGFR mutation status is recommended, however, the frequency of EGFR mutation in patients with ILD and the efficacy and safety of EGFR-TKI in patients with ILD and EGFR mutation are unknown. Methods. We retrospectively reviewed the association of the EGFR mutation status of nonsmall cell lung cancer and pulmonary diseases. Based on high-resolution computed tomography (HRCT performed at diagnosis of lung cancer, patients were categorized into three groups: normal, emphysema, and fibrosis. Results. Of 198 patients with nonsmall cell lung cancer, we identified 52 (26.3% patients with an EGFR mutation. EGFR mutations were identified in 43 (35.2% of 122 patients with normal lungs, 8 (13.6% of 59 with emphysema, and 1 (5.9% of 17 with pulmonary fibrosis. Of the 52 patients with EGFR mutation, 43 patients received gefitinib. One patient with an EGFR mutation and fibrosis developed fatal ILD. There was not a significant difference in median overall survival from gefitinib treatment between never-smokers and smokers (797 days versus not reached; =0.96. Conclusions. Patients with sensitive EGFR mutation and normal lungs may benefit from an EGFR-TKI treatment even if they have smoking history.

  20. Adult mouse subventricular zone stem and progenitor cells are sessile and epidermal growth factor receptor negatively regulates neuroblast migration.

    Directory of Open Access Journals (Sweden)

    Yongsoo Kim

    Full Text Available BACKGROUND: The adult subventricular zone (SVZ contains stem and progenitor cells that generate neuroblasts throughout life. Although it is well accepted that SVZ neuroblasts are migratory, recent evidence suggests their progenitor cells may also exhibit motility. Since stem and progenitor cells are proliferative and multipotential, if they were also able to move would have important implications for SVZ neurogenesis and its potential for repair. METHODOLOGY/PRINCIPAL FINDINGS: We studied whether SVZ stem and/or progenitor cells are motile in transgenic GFP+ slices with two photon time lapse microscopy and post hoc immunohistochemistry. We found that stem and progenitor cells; mGFAP-GFP+ cells, bright nestin-GFP+ cells and Mash1+ cells were stationary in the SVZ and rostral migratory stream (RMS. In our search for motile progenitor cells, we uncovered a population of motile betaIII-tubulin+ neuroblasts that expressed low levels of epidermal growth factor receptor (EGFr. This was intriguing since EGFr drives proliferation in the SVZ and affects migration in other systems. Thus we examined the potential role of EGFr in modulating SVZ migration. Interestingly, EGFr(low neuroblasts moved slower and in more tortuous patterns than EGFr-negative neuroblasts. We next questioned whether EGFr stimulation affects SVZ cell migration by imaging Gad65-GFP+ neuroblasts in the presence of transforming growth factor alpha (TGF-alpha, an EGFr-selective agonist. Indeed, acute exposure to TGF-alpha decreased the percentage of motile cells by approximately 40%. CONCLUSIONS/SIGNIFICANCE: In summary, the present study directly shows that SVZ stem and progenitor cells are static, that EGFr is retained on some neuroblasts, and that EGFr stimulation negatively regulates migration. This result suggests an additional role for EGFr signaling in the SVZ.

  1. The hepatocyte growth factor (HGF)-MET receptor tyrosine kinase signaling pathway: Diverse roles in modulating immune cell functions.

    Science.gov (United States)

    Ilangumaran, Subburaj; Villalobos-Hernandez, Alberto; Bobbala, Diwakar; Ramanathan, Sheela

    2016-06-01

    Hepatocyte growth factor (HGF) signaling via the MET receptor is essential for embryonic development and tissue repair. On the other hand, deregulated MET signaling promotes tumor progression in diverse types of cancers. Even though oncogenic MET signaling remains the major research focus, the HGF-MET axis has also been implicated in diverse aspects of immune cell development and functions. In the presence of other hematopoietic growth factors, HGF promotes the development of erythroid, myeloid and lymphoid lineage cells and thrombocytes. In monocytes and macrophages responding to inflammatory stimuli, induction of autocrine HGF-MET signaling can contribute to tissue repair via stimulating anti-inflammatory cytokine production. HGF-MET signaling can also modulate adaptive immune response by facilitating the migration of Langerhans cells and dendritic cells to draining lymph nodes. However, MET signaling has also been shown to induce tolerogenic dendritic cells in mouse models of graft-versus-host disease and experimental autoimmune encephalomyelitis. HGF-MET axis is also implicated in promoting thymopoiesis and the survival and migration of B lymphocytes. Recent studies have shown that MET signaling induces cardiotropism in activated T lymphocytes. Further understanding of the HGF-MET axis in the immune system would allow its therapeutic manipulation to improve immune cell reconstitution, restore immune homeostasis and to treat immuno-inflammatory diseases. PMID:26822708

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

    International Nuclear Information System (INIS)

    We investigated whether the gene expression of vascular endothelial growth factor (VEGF) and its receptors (VEGFR and neuropilin-1 [NRP-1]) could be specifically regulated during the megakaryocytic differentiation of human thrombopoietin (TPO)-dependent UT-7/TPO cells. Undifferentiated UT-7/TPO cells expressed a functional VEGFR-2, leading to VEGF binding and VEGF165-induced tyrosine phosphorylation, cell proliferation, and apoptosis inhibition. The megakaryocytic differentiation of UT-7/TPO cells on treatment with phorbol myristate acetate (PMA) was accompanied by a marked up-regulation of NRP-1 mRNA and protein expression and by an increase in VEGF-binding activity, which was mainly mediated by VEGFR-2. VEGF165 promoted the formation of complexes containing NRP-1 and VEGFR-2 in undifferentiated UT-7/TPO cells in a dose-dependent manner. Unlike human umbilical vein endothelial cells, PMA-differentiated UT-7/TPO cells exhibited complex formation between NRP-1 and VEGFR-2 even in the absence of VEGF165. These findings suggest that NRP-1-VEGFR-2-complex formation may contribute to effective cellular functions mediated by VEGF165 in megakaryocytic cells.

  3. Influence of baicalin on the expression of receptor activator of nuclear factor-κB ligand and osteoprotegerin in human periodontal ligament cells

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Objective To study the effect of baicalin on the expression of receptor activator of nuclear factor-κB ligand(RANKL)and osteoprotegerin(OPG)in cultured human periodontal ligament(HPDL)cells.Methods Small interfering RNA(siRNA)eukaryotic expression vector targeted transforming growth factor βⅡ receptor(TGF-β RⅡ)was constructed and transfected into T cells.HPDL cells with T cells transfected with siRNA or not were placed in the culture medium that had been added with lipopolysaccharide(LPS)and baicalin.The ob...

  4. Epidermal growth factor (EGF) receptor gene transcription

    International Nuclear Information System (INIS)

    The authors have studied in vitro transcription of the human epidermal growth factor (EGF) receptor proto-oncogene using nuclear extracts of A431 human epidermoid carcinoma cells, which overproduce the EGF receptor. With the in vitro system we found that Sp1 and other trans-acting factors bound to the EGF receptor promoter regions and are required for maximal expression. Fractionation showed that a DEAE-Sepharose fraction (BA) contained a novel factor, which specifically stimulated EGF receptor transcription 5- to 10-fold. The molecular mass of the native form of the factor is about 270-kDa based on its migration on Sephacryl S-300. This factor may activate transcription of the proto-oncogene through a weak or indirect interaction with the DNA template

  5. 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)

    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-Δ12,14-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

  6. Inhibition of invasiveness and expression of epidermal growth factor receptor in human colorectal carcinoma cells induced by retinoic acid

    Institute of Scientific and Technical Information of China (English)

    SUNBAODONG; JINDANSONG

    1995-01-01

    Human amniotic basement membrane (HABM) model and agarose drop explant method were used to investigate the effects of retinoic acid(RA) on the invasive ness and adhesiveness to the basement membrane,and the migration of a highly invasive human colorectal cancer cell line CCL229.Results showed that 5×106 MRA markedly reduced the in vitro invasiveness and adhesiveness to the HABM,and the migration of the CCL229 cells.In addition,to elucidate the relation between expression of epidermal growth factor receptor(EGFR) and the invasiveness of the colorectal carcinoma cells,two well-differentiated,but with different invasiveness colorectal cancer cell lines were compared at mRNA level for expression of EGFR by using EGFR cDNA probe labeled with digoxigenin(DIG). Expression of EGFR was shown to be markedly higher in the highly invassive CCL229 cells than that in the low invasive CX-1 cells.Furthermore,expression of EGFR in RA treated CCL229 cells gradually decreased with time,the level being the lowest on day 6 of the RA treatment.

  7. The Epidermal Growth Factor Receptor Responsive miR-125a Represses Mesenchymal Morphology in Ovarian Cancer Cells

    Directory of Open Access Journals (Sweden)

    Karen D. Cowden Dahl

    2009-11-01

    Full Text Available The epithelial-to-mesenchymal transition (EMT that occurs during embryonic development is recapitulated during tumor metastasis. Important regulators of this process include growth factors, transcription factors, and adhesion molecules. New evidence suggests that microRNA (miRNA activity contributes to metastatic progression and EMT; however, the mechanisms leading to altered miRNA expression during cancer progression remain poorly understood. Importantly, overexpression of the epidermal growth factor receptor (EGFR in ovarian cancer correlates with poor disease outcome and induces EMT in ovarian cancer cells. We report that EGFR signaling leads to transcriptional repression of the miRNA miR-125a through the ETS family transcription factor PEA3. Overexpression of miR-125a induces conversion of highly invasive ovarian cancer cells from a mesenchymal to an epithelial morphology, suggesting miR-125a is a negative regulator of EMT. We identify AT-rich interactive domain 3B (ARID3B as a target of miR-125a and demonstrate that ARID3B is overexpressed in human ovarian cancer. Repression of miR-125a through growth factor signaling represents a novel mechanism for regulating ovarian cancer invasive behavior.

  8. Stromal cell-derived factor-1α (SDF-1α/CXCL12) stimulates ovarian cancer cell growth through the EGF receptor transactivation

    International Nuclear Information System (INIS)

    Ovarian cancer (OC) is the leading cause of death in gynecologic diseases in which there is evidence for a complex chemokine network. Chemokines are a family of proteins that play an important role in tumor progression influencing cell proliferation, angiogenic/angiostatic processes, cell migration and metastasis, and, finally, regulating the immune cells recruitment into the tumor mass. We previously demonstrated that astrocytes and glioblastoma cells express both the chemokine receptor CXCR4 and its ligand stromal cell-derived factor-1 (SDF-1), and that SDF-1α treatment induced cell proliferation, supporting the hypothesis that chemokines may play an important role in tumor cells' growth in vitro. In the present study, we report that CXCR4 and SDF-1 are expressed in OC cell lines. We demonstrate that SDF-1α induces a dose-dependent proliferation in OC cells, by the specific interaction with CXCR4 and a biphasic activation of ERK1/2 and Akt kinases. Our results further indicate that CXCR4 activation induces EGF receptor (EGFR) phosphorylation that in turn was linked to the downstream intracellular kinases activation, ERK1/2 and Akt. In addition, we provide evidence for cytoplasmic tyrosine kinase (c-Src) involvement in the SDF-1/CXCR4-EGFR transactivation. These results suggest a possible important 'cross-talk' between SDF-1/CXCR4 and EGFR intracellular pathways that may link signals of cell proliferation in ovarian cancer

  9. Novel nuclear localization and potential function of insulin-like growth factor-1 receptor/insulin receptor hybrid in corneal epithelial cells.

    Directory of Open Access Journals (Sweden)

    Yu-Chieh Wu

    Full Text Available BACKGROUND: Type I insulin-like growth factor receptor (IGF-1R and insulin receptor (INSR are highly homologous molecules, which can heterodimerize to form an IGF-1R/INSR hybrid (Hybrid-R. The presence and biological significance of the Hybrid-R in human corneal epithelium has not yet been established. In addition, while nuclear localization of IGF-1R was recently reported in cancer cells and human corneal epithelial cells, the function and profile of nuclear IGF-1R is unknown. In this study, we characterized the nuclear localization and function of the Hybrid-R and the role of IGF-1/IGF-1R and Hybrid-R signaling in the human corneal epithelium. METHODOLOGY/PRINCIPLE FINDINGS: IGF-1-mediated signaling and cell growth were examined in a human telomerized corneal epithelial (hTCEpi cell line using co-immunoprecipitation, immunoblotting and cell proliferation assays. The presence of Hybrid-R in hTCEpi and primary cultured human corneal epithelial cells was confirmed by immunofluorescence and reciprocal immunoprecipitation of whole cell lysates. We found that IGF-1 stimulated Akt and promoted cell growth through IGF-1R activation, which was independent of the Hybrid-R. The presence of Hybrid-R, but not IGF-1R/IGF-1R, was detected in nuclear extracts. Knockdown of INSR by small interfering RNA resulted in depletion of the INSR/INSR and preferential formation of Hybrid-R. Chromatin-immunoprecipitation sequencing assay with anti-IGF-1R or anti-INSR was subsequently performed to identify potential genomic targets responsible for critical homeostatic regulatory pathways. CONCLUSION/SIGNIFICANCE: In contrast to previous reports on nuclear localized IGF-1R, this is the first report identifying the nuclear localization of Hybrid-R in an epithelial cell line. The identification of a nuclear Hybrid-R and novel genomic targets suggests that IGF-1R traffics to the nucleus as an IGF-1R/INSR heterotetrameric complex to regulate corneal epithelial homeostatic

  10. Characterization of insulin-like growth factor I and insulin receptors on cultured bovine adrenal fasciculata cells. Role of these peptides on adrenal cell function

    International Nuclear Information System (INIS)

    We have characterized insulin-like growth factor I (IGF-I) and insulin receptors in cultured bovine adrenal cells by binding and cross-linking affinity experiments. At equilibrium the dissociation constant and the number of binding sites per cell for IGF-I were 1.4 +/- (SE) 0.3 x 10(-9) M and 19,200 +/- 2,100, respectively. Under reduction conditions, disuccinimidyl suberate cross-linked [125I]iodo-IGF-I to one receptor complex with an Mr of 125,000. Adrenal cells also contain specific insulin receptors with an apparent dissociation constant (Kd) of 10(-9) M. Under reduction conditions [125I]iodo-insulin binds to one band with an approximate Mr of 125,000. IGF-I and insulin at micromolar concentrations, but not at nanomolar concentrations, slightly stimulated DNA synthesis, but markedly potentiated the mitogenic action of fibroblast growth factor. Adrenal cells cultured in a serum-free medium containing transferrin, ascorbic acid, and insulin (5 micrograms/ml) maintained fairly constant angiotensin-II (A-II) receptor concentration per cell and increased cAMP release on response to ACTH and their steroidogenic response to both ACTH and A-II. When the cells were cultured in the same medium without insulin, the number of A-II receptors significantly decreased to 65% and the increased responsiveness was blunted. Treatment of such cells for 3 days with increasing concentrations of IGF-I (1-100 ng/ml) produced a 2- to 3-fold increase in A-II receptors and enhanced the cAMP response (3- to 4-fold) to ACTH and the steroidogenic response (4- to 6-fold) to ACTH and A-II. These effects were time and dose dependent (ED50 approximately equal to 10(-9) M). Insulin at micromolar concentrations produced an effect similar to that of IGF-I, but at nanomolar concentrations the effect was far less

  11. High-affinity insulin binding to an atypical insulin-like growth factor-I receptor in human breast cancer cells.

    OpenAIRE

    Milazzo, G.; Yip, C. C.; Maddux, B A; Vigneri, R; Goldfine, I D

    1992-01-01

    We studied the nature of insulin receptor binding in MCF-7 breast cancer cells. In both intact cells and solubilized receptor preparations, high-affinity insulin binding was seen. However, unlabeled insulin-like growth factor-I (IGF-I) was five-fold more potent in inhibiting 125I-insulin binding than insulin itself. With monoclonal antibodies to the insulin receptor, 30% of 125I-insulin binding was inhibited. In contrast when alpha-IR3, a monoclonal antibody that recognizes typical IGF-I rece...

  12. Epidermal growth factor receptor inhibition reduces angiogenesis via hypoxia-inducible factor-1α and Notch1 in head neck squamous cell carcinoma.

    Directory of Open Access Journals (Sweden)

    Wei-Ming Wang

    Full Text Available Angiogenesis, a marker of cancer development, affects response to radiotherapy sensibility. This preclinical study aims to understand the receptor tyrosine kinase-mediated angiogenesis in head neck squamous cell carcinoma (HNSCC. The receptor tyrosine kinase activity in a transgenic mouse model of HNSCC was assessed. The anti-tumorigenetic and anti-angiogenetic effects of cetuximab-induced epidermal growth factor receptor (EGFR inhibition were investigated in xenograft and transgenic mouse models of HNSCC. The signaling transduction of Notch1 and hypoxia-inducible factor-1α (HIF-1α was also analyzed. EGFR was overexpressed and activated in the Tgfbr1/Pten deletion (2cKO mouse model of HNSCC. Cetuximab significantly delayed tumor onset by reducing tumor angiogenesis. This drug exerted similar effects on heterotopic xenograft tumors. In the human HNSCC tissue array, increased EGFR expression correlated with increased HIF-1α and micro vessel density. Cetuximab inhibited tumor-induced angiogenesis in vitro and in vivo by significantly downregulating HIF-1α and Notch1. EGFR is involved in the tumor angiogenesis of HNSCC via the HIF-1α and Notch1 pathways. Therefore, targeting EGFR by suppressing hypoxia- and Notch-induced angiogenesis may benefit HNSCC therapy.

  13. Enediyne lidamycin enhances the effect of epidermal growth factor receptor tyrosine kinase inhibitor, gefitinib, in epidermoid carcinoma A431 cells and lung carcinoma H460 cells.

    Science.gov (United States)

    Liu, Hong; Li, Liang; Li, Xing-Qi; Liu, Xiu-Jun; Zhen, Yong-Su

    2009-01-01

    Gefitinib, a low-molecular-weight epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor, is effective in a wide variety of tumor types. Preclinical studies have shown potentiated antitumor efficacies of this agent in combination with chemotherapy or radiotherapy. The antitumor antibiotic lidamycin (LDM) showed extremely potent cytotoxicity in vitro and marked therapeutic effect in vivo. In this report, the cytotoxic and biochemical activity of LDM and gefitinib on human epidermoid carcinoma A431 cells and human large cell lung cancer H460 cells as a single agent or in combination has been evaluated. In the MTT assay, LDM showed much more potent cytotoxicity than gefitinib to both cell lines. A431 cells with a highly EGFR-expressing level were more sensitive to gefitinib than H460 cells, which expressed EGFR at an intermediate level. LDM plus gefitinib showed potentiation of antiproliferative activity and apoptosis induction, which were associated with downregulation of EGFR signaling pathway and nuclear factor-kappa B expression, and the increase of cleaved poly (adenosine diphosphate-ribose) polymerase in the two cell lines, although to a lesser degree in H460 cells. Combined treatment induced G1 phase arrest similar to that of gefitinib alone in A431 cells and intensified G2/M phase accumulation in H460 cells. The above results indicate that LDM potentiates the effects of gefitinib in both gefitinib sensitive and less sensitive cells in association with enhanced inhibition of EGFR-dependent signaling. PMID:19342999

  14. UV-B Radiation Induces Macrophage Migration Inhibitory Factor–Mediated Melanogenesis through Activation of Protease-Activated Receptor-2 and Stem Cell Factor in Keratinocytes

    OpenAIRE

    Enomoto, Akiko; Yoshihisa, Yoko; Yamakoshi, Takako; Ur Rehman, Mati; Norisugi, Osamu; HARA Hiroshi; Matsunaga, Kenji; Makino, Teruhiko; Nishihira, Jun; Shimizu, Tadamichi

    2011-01-01

    UV radiation indirectly regulates melanogenesis in melanocytes through a paracrine regulatory mechanism involving keratinocytes. Protease-activated receptor (PAR)-2 activation induces melanosome transfer by increasing phagocytosis of melanosomes by keratinocytes. This study demonstrated that macrophage migration inhibitory factor (MIF) stimulated PAR-2 expression in human keratinocytes. In addition, we showed that MIF stimulated stem cell factor (SCF) release in keratinocytes; however, MIF ha...

  15. UDP acts as a growth factor for vascular smooth muscle cells by activation of P2Y(6) receptors

    DEFF Research Database (Denmark)

    Hou, Mingyan; Harden, T Kendall; Kuhn, Cynthia M; Baldetorp, Bo; Lazarowski, Eduardo; Pendergast, William; Möller, Sebastian; Edvinsson, Lars; Erlinge, David

    2002-01-01

    Mitogenic effects of the extracellular nucleotides ATP and UTP are mediated by P2Y(1), P2Y(2), and P2Y(4) receptors. However, it has not been possible to examine the highly expressed UDP-sensitive P2Y(6) receptor because of the lack of stable, selective agonists. In rat aorta smooth muscle cells ...

  16. STAT6 Transcription Factor Is a Facilitator of the Nuclear Receptor PPARγ-Regulated Gene Expression in Macrophages and Dendritic Cells

    OpenAIRE

    Szanto, Attila; Balint, Balint L.; Nagy, Zsuzsanna S.; Barta, Endre; Dezso, Balazs; Pap, Attila; Szeles, Lajos; Poliska, Szilard; Oros, Melinda; Ronald M. Evans; Barak, Yaacov; Schwabe, John; Nagy, Laszlo

    2010-01-01

    Summary Peroxisome proliferator-activated receptor γ (PPARγ) is a lipid-activated transcription factor regulating lipid metabolism and inflammatory response in macrophages and dendritic cells (DCs). These immune cells exposed to distinct inflammatory milieu show cell type specification as a result of altered gene expression. We demonstrate here a mechanism how inflammatory molecules modulate PPARγ signaling in distinct subsets of cells. Proinflammatory molecules inhibited whereas interleukin-...

  17. Expression of stem cell factor and its receptor c-Kit during the development of intrahepatic cholangiocarcinoma.

    Science.gov (United States)

    Mansuroglu, Tümen; Ramadori, Pierluigi; Dudás, József; Malik, Ihtzaz; Hammerich, Kristoff; Füzesi, László; Ramadori, Giuliano

    2009-05-01

    Stem cell factor (SCF) and its receptor, c-Kit, constitute an important signal transduction system with proliferative and anti-apoptotic functions. Besides regulating hemopoietic stem cell proliferation and liver regeneration, it has been implicated in the regulation of human malignancies. However, the cellular expression of the SCF-c-Kit gene system in the liver during cholangiocarcinogenesis has not been studied to date. The protein- and mRNA-expression levels of SCF and c-Kit genes were examined in normal rat liver, in isolated normal rat liver cells and in a thioacetamide-induced rat model of intrahepatic cholangiocarcinoma (CC). Immunohistochemical analysis of the normal liver showed that SCF is expressed in the wall of the hepatic artery and in some cells, which were located along the sinusoids, although it was absent from hepatocytes and biliary epithelial cells. The mRNA analysis of isolated normal liver cell populations revealed a co-expression of SCF- and c-Kit-mRNA in sinusoidal endothelial cells and in Kupffer cells, whereas passaged and cultured liver myofibroblasts (MFs) expressed only SCF. Low levels of the SCF- and c-Kit-mRNA expression could be detected in isolated hepatocytes of the normal liver. Immunohistochemical analysis of the CC tissue showed SCF positivity in proliferating biliary cells (CK-19(+)), in macrophages (ED-1(+)) and in MFs (alpha-smooth-muscle-actin, alpha-SMA(+)) of the tumoral microenvironment. c-Kit-positivity could be detected on hepatocytes of the regenerating nodules and on the proliferating bile ducts of CC. Compared with the normal liver tissue, SCF-mRNA from the CC tissue was upregulated up to 20-fold, whereas c-Kit-mRNA was upregulated up to fivefold. These data indicate that several cell populations may become able to express SCF and/or c-Kit during cholangiocarcinogenesis. Therefore, the SCF-c-Kit system may contribute to tumor development, for instance, by inducing proliferation of hepatocytes and of biliary cells

  18. Role of protein kinase C and epidermal growth factor receptor signalling in growth stimulation by neurotensin in colon carcinoma cells

    International Nuclear Information System (INIS)

    Neurotensin has been found to promote colon carcinogenesis in rats and mice, and proliferation of human colon carcinoma cell lines, but the mechanisms involved are not clear. We have examined signalling pathways activated by neurotensin in colorectal and pancreatic carcinoma cells. Colon carcinoma cell lines HCT116 and HT29 and pancreatic adenocarcinoma cell line Panc-1 were cultured and stimulated with neurotensin or epidermal growth factor (EGF). DNA synthesis was determined by incorporation of radiolabelled thymidine into DNA. Levels and phosphorylation of proteins in signalling pathways were assessed by Western blotting. Neurotensin stimulated the phosphorylation of both extracellular signal-regulated kinase (ERK) and Akt in all three cell lines, but apparently did so through different pathways. In Panc-1 cells, neurotensin-induced phosphorylation of ERK, but not Akt, was dependent on protein kinase C (PKC), whereas an inhibitor of the β-isoform of phosphoinositide 3-kinase (PI3K), TGX221, abolished neurotensin-induced Akt phosphorylation in these cells, and there was no evidence of EGF receptor (EGFR) transactivation. In HT29 cells, in contrast, the EGFR tyrosine kinase inhibitor gefitinib blocked neurotensin-stimulated phosphorylation of both ERK and Akt, indicating transactivation of EGFR, independently of PKC. In HCT116 cells, neurotensin induced both a PKC-dependent phosphorylation of ERK and a metalloproteinase-mediated transactivation of EGFR that was associated with a gefitinib-sensitive phosphorylation of the downstream adaptor protein Shc. The activation of Akt was also inhibited by gefitinib, but only partly, suggesting a mechanism in addition to EGFR transactivation. Inhibition of PKC blocked neurotensin-induced DNA synthesis in HCT116 cells. While acting predominantly through PKC in Panc-1 cells and via EGFR transactivation in HT29 cells, neurotensin used both these pathways in HCT116 cells. In these cells, neurotensin-induced activation of ERK

  19. Role of protein kinase C and epidermal growth factor receptor signalling in growth stimulation by neurotensin in colon carcinoma cells

    Directory of Open Access Journals (Sweden)

    Dajani Olav

    2011-10-01

    Full Text Available Abstract Background Neurotensin has been found to promote colon carcinogenesis in rats and mice, and proliferation of human colon carcinoma cell lines, but the mechanisms involved are not clear. We have examined signalling pathways activated by neurotensin in colorectal and pancreatic carcinoma cells. Methods Colon carcinoma cell lines HCT116 and HT29 and pancreatic adenocarcinoma cell line Panc-1 were cultured and stimulated with neurotensin or epidermal growth factor (EGF. DNA synthesis was determined by incorporation of radiolabelled thymidine into DNA. Levels and phosphorylation of proteins in signalling pathways were assessed by Western blotting. Results Neurotensin stimulated the phosphorylation of both extracellular signal-regulated kinase (ERK and Akt in all three cell lines, but apparently did so through different pathways. In Panc-1 cells, neurotensin-induced phosphorylation of ERK, but not Akt, was dependent on protein kinase C (PKC, whereas an inhibitor of the β-isoform of phosphoinositide 3-kinase (PI3K, TGX221, abolished neurotensin-induced Akt phosphorylation in these cells, and there was no evidence of EGF receptor (EGFR transactivation. In HT29 cells, in contrast, the EGFR tyrosine kinase inhibitor gefitinib blocked neurotensin-stimulated phosphorylation of both ERK and Akt, indicating transactivation of EGFR, independently of PKC. In HCT116 cells, neurotensin induced both a PKC-dependent phosphorylation of ERK and a metalloproteinase-mediated transactivation of EGFR that was associated with a gefitinib-sensitive phosphorylation of the downstream adaptor protein Shc. The activation of Akt was also inhibited by gefitinib, but only partly, suggesting a mechanism in addition to EGFR transactivation. Inhibition of PKC blocked neurotensin-induced DNA synthesis in HCT116 cells. Conclusions While acting predominantly through PKC in Panc-1 cells and via EGFR transactivation in HT29 cells, neurotensin used both these pathways in HCT116

  20. Tyrosine kinase activity of a chimeric insulin-like-growth-factor-1 receptor containing the insulin receptor C-terminal domain. Comparison with the tyrosine kinase activities of the insulin and insulin-like-growth-factor-1 receptors using a cell-free system.

    Science.gov (United States)

    Mothe, I; Tartare, S; Kowalski-Chauvel, A; Kaliman, P; Van Obberghen, E; Ballotti, R

    1995-03-15

    In a previous study, we showed that a chimeric insulin-like-growth-factor-1 (IGF-1) receptor, with the beta subunit C-terminal part of the insulin receptor was more efficient in stimulating glycogen synthesis and p44mapk activity compared to the wild-type IFG-1 receptor [Tartare, S., Mothe, I., Kowalski-Chauvel, A., Breittmayer, J.-P., Ballotti, R. & Van Obberghen, E. (1994) J. Biol. Chem. 269, 11449-11455]. These data indicate that the receptor C-terminal domain plays an important role in the transmission of biological effects. To understand the molecular basis of the differences in receptor specificity, we studied the characteristics of insulin, IGF-1 and chimeric receptor tyrosine kinase activities in a cell-free system. We found that, compared to wild-type insulin and IGF-1 receptors, the chimeric receptor showed a decrease in (a) autophosphorylation, (b) tyrosine kinase activity towards insulin receptor substrate-1 and the insulin receptor-(1142-1158)-peptide, and (c) the ability to activate phosphatidylinositol 3-kinase. However, for all the effects measured in a cell-free system, the chimeric receptor displayed an increased response to IGF-1 compared to the native IGF-1 receptor. Concerning the cation dependence of the tyrosine kinase activity, we showed that, at 10 mM Mg2+, the ligand-stimulated phosphorylation of poly(Glu80Tyr20) by both insulin receptor and chimeric receptor was increased by Mn2+. Conversely at 50 mM Mg2+, the chimeric receptor behaved like the IGF-1 receptor, since the presence of Mn2+ decreased the stimulatory effect of IGF-1 on their kinase activity. Furthermore, the Km of the chimeric receptor for ATP was increased compared to the wild-type receptors. These data demonstrate that the replacement of the C-terminal tail of the IGF-1 receptor by that of the insulin receptor has changed the receptor characteristics studied in a cell-free system. Our findings indicate that the C-terminal domain of the insulin receptor beta subunit plays a

  1. Farnesoid X Receptor, through the Binding with Steroidogenic Factor 1-responsive Element, Inhibits Aromatase Expression in Tumor Leydig Cells*

    OpenAIRE

    Catalano, Stefania; Malivindi, Rocco; Giordano, Cinzia; Gu, Guowei; Panza, Salvatore; Bonofiglio, Daniela; Lanzino, Marilena; Sisci, Diego; Panno, Maria Luisa; Andò, Sebastiano

    2009-01-01

    The farnesoid X receptor (FXR) is a member of the nuclear receptor superfamily that regulates bile acid homeostasis. It is expressed in the liver and the gastrointestinal tract, but also in several non-enterohepatic tissues including testis. Recently, FXR was identified as a negative modulator of the androgen-estrogen-converting aromatase enzyme in human breast cancer cells. In the present study we detected the expression of FXR in Leydig normal and tumor cell lines and in rat testes tissue. ...

  2. Transforming growth factor β2 (TGF-β2)-induced connective tissue growth factor (CTGF) expression requires sphingosine 1-phosphate receptor 5 (S1P5) in human mesangial cells

    NARCIS (Netherlands)

    Wünsche, Christin; Koch, Alexander; Goldschmeding, Roel; Schwalm, Stephanie; Meyer Zu Heringdorf, Dagmar; Huwiler, Andrea; Pfeilschifter, Josef

    2015-01-01

    Transforming growth factor β2 (TGF-β2) is well known to stimulate the expression of pro-fibrotic connective tissue growth factor (CTGF) in several cell types including human mesangial cells. The present study demonstrates that TGF-β2 enhances sphingosine 1-phosphate receptor 5 (S1P5) mRNA and protei

  3. The synthetic inhibitor of Fibroblast Growth Factor Receptor PD166866 controls negatively the growth of tumor cells in culture

    Directory of Open Access Journals (Sweden)

    Castelli Mauro

    2009-12-01

    Full Text Available Abstract Background Many experimental data evidence that over-expression of various growth factors cause disorders in cell proliferation. The role of the Fibroblast Growth Factors (FGF in growth control is indisputable: in particular, FGF1 and its tyrosine kinase receptor (FGFR1 act through a very complex network of mechanisms and pathways. In this work we have evaluated the antiproliferative activity effect of PD166866, a synthetic molecule inhibiting the tyrosin kinase action of FGFR1. Methods Cells were routinely grown in Dulbecco Modified Eagle's medium supplemented with newborn serum and a penicillin-streptomycin mixture. Cell viability was evaluated by Mosmann assay and by trypan blue staining. DNA damage was assessed by in situ fluorescent staining with Terminal Deoxynucleotidyl Transferase dUTP nick end labeling (TUNEL assay. Assessment of oxidative stress at membrane level was measured by quantitative analysis of the intra-cellular formation of malonyl-dialdheyde (MDA deriving from the decomposition of poly-unsaturated fatty acids. The expression of Poly-ADP-Ribose-Polymerase (PARP, consequent to DNA fragmentation, was evidenced by immuno-histochemistry utilizing an antibody directed against an N-terminal fragment of the enzyme. Results The bioactivity of the drug was investigated on Hela cells. Cytoxicity was assessed by the Mosmann assay and by vital staining with trypan blue. The target of the molecule is most likely the cell membrane as shown by the significant increase of the intracellular concentration of malonyl-dihaldheyde. The increase of this compound, as a consequence of the treatment with PD166866, is suggestive of membrane lipoperoxidation. The TUNEL assay gave a qualitative, though clear, indication of DNA damage. Furthermore we demonstrate intracellular accumulation of poly-ADP-ribose polymerase I. This enzyme is a sensor of nicks on the DNA strands and this supports the idea that treatment with the drug induces cell

  4. Mn-doped Zinc Sulphide nanocrystals for immunofluorescent labeling of epidermal growth factor receptors on cells and clinical tumor tissues

    Science.gov (United States)

    J, Aswathy; V, Seethalekshmy N.; R, Hiran K.; R, Bindhu M.; K, Manzoor; Nair, Shantikumar V.; Menon, Deepthy

    2014-11-01

    The field of molecular detection and targeted imaging has evolved considerably with the introduction of fluorescent semiconductor nanocrystals. Manganese-doped zinc sulphide nanocrystals (ZnS:Mn NCs), which are widely used in electroluminescent displays, have been explored for the first time for direct immunofluorescent (IF) labeling of clinical tumor tissues. ZnS:Mn NCs developed through a facile wet chemistry route were capped using amino acid cysteine, conjugated to streptavidin and thereafter coupled to biotinylated epidermal growth factor receptor (EGFR) antibody utilizing the streptavidin-biotin linkage. The overall conjugation yielded stable EGFR antibody conjugated ZnS:Mn NCs (EGFR ZnS:Mn NCs) with a hydrodynamic diameter of 65 ± 15 nm, and having an intense orange-red fluorescence emission at 598 nm. Specific labeling of EGF receptors on EGFR+ve A431 cells in a co-culture with EGFR-ve NIH3T3 cells was demonstrated using these nanoprobes. The primary antibody conjugated fluorescent NCs could also clearly delineate EGFR over-expressing cells on clinical tumor tissues processed by formalin fixation as well as cryopreservation with a specificity of 86% and accuracy of 88%, in comparison to immunohistochemistry. Tumor tissues labeled with EGFR ZnS:Mn NCs showed good fluorescence emission when imaged after storage even at 15 months. Thus, ZnS nanobioconjugates with dopant-dependent and stable fluorescence emission show promise as an efficient, target-specific fluorophore that would enable long term IF labeling of any antigen of interest on clinical tissues.

  5. Mn-doped Zinc Sulphide nanocrystals for immunofluorescent labeling of epidermal growth factor receptors on cells and clinical tumor tissues

    International Nuclear Information System (INIS)

    The field of molecular detection and targeted imaging has evolved considerably with the introduction of fluorescent semiconductor nanocrystals. Manganese-doped zinc sulphide nanocrystals (ZnS:Mn NCs), which are widely used in electroluminescent displays, have been explored for the first time for direct immunofluorescent (IF) labeling of clinical tumor tissues. ZnS:Mn NCs developed through a facile wet chemistry route were capped using amino acid cysteine, conjugated to streptavidin and thereafter coupled to biotinylated epidermal growth factor receptor (EGFR) antibody utilizing the streptavidin–biotin linkage. The overall conjugation yielded stable EGFR antibody conjugated ZnS:Mn NCs (EGFR ZnS:Mn NCs) with a hydrodynamic diameter of 65 ± 15 nm, and having an intense orange–red fluorescence emission at 598 nm. Specific labeling of EGF receptors on EGFR+ve A431 cells in a co-culture with EGFR−ve NIH3T3 cells was demonstrated using these nanoprobes. The primary antibody conjugated fluorescent NCs could also clearly delineate EGFR over-expressing cells on clinical tumor tissues processed by formalin fixation as well as cryopreservation with a specificity of 86% and accuracy of 88%, in comparison to immunohistochemistry. Tumor tissues labeled with EGFR ZnS:Mn NCs showed good fluorescence emission when imaged after storage even at 15 months. Thus, ZnS nanobioconjugates with dopant-dependent and stable fluorescence emission show promise as an efficient, target-specific fluorophore that would enable long term IF labeling of any antigen of interest on clinical tissues. (paper)

  6. Basic fibroblast growth factor increases the number of endogenous neural stem cells and inhibits the expression of amino methyl isoxazole propionic acid receptors in amyotrophic lateral sclerosis mice

    Institute of Scientific and Technical Information of China (English)

    Weihui Huang; Dawei Zang; Yi Lu; Ping Jiang

    2012-01-01

    This study aimed to investigate the number of amino methyl isoxazole propionic acid (AMPA) re-ceptors and production of endogenous neural stem cells in the SOD1G93AG1H transgenic mouse model of amyotrophic lateral sclerosis, at postnatal day 60 following administration of basic fibroblast growth factor (FGF-2). A radioligand binding assay and immunohistochemistry were used to estimate the number of AMPA receptors and endogenous neural stem cells respectively. Results showed that the number of AMPA receptors and endogenous neural stem cells in the brain stem and sensorimotor cortex were significantly increased, while motor function was significantly decreased at postnatal days 90 and 120. After administration of FGF-2 into mice, numbers of endogenous neural stem cells increased, while expression of AMPA receptors decreased, whilst motor functions were recovered. At postnatal day 120, the number of AMPA receptors was negatively correlated with the number of endogenous neural stem cells in model mice and FGF-2-treated mice. Our experimental findings indicate that FGF-2 can inhibit AMPA receptors and increase the number of endogenous neural stem cells, thus repairing neural injury in amyotrophic lateral sclerosis mice.

  7. Activation of insulin-like growth factor 1 receptor in patients with non-small cell lung cancer.

    Science.gov (United States)

    Kim, Jin-Soo; Kim, Edward S; Liu, Diane; Lee, J Jack; Behrens, Carmen; Lippman, Scott M; Hong, Waun Ki; Wistuba, Ignacio I; Lee, Euni; Lee, Ho-Young

    2015-06-30

    According to previous reports demonstrating the implication of insulin-like growth factor receptor (IGF-1R) signaling in non-small cell lung cancer (NSCLC), in this study, the potential prognostic values of IGF-1R expression/activation were analyzed. The expression and activation of IGF-1R were evaluated in two tissue microarray (TMA) sets from NSCLC patients (N = 352 for TMA I, and N = 353 for TMA II). Alterations in IGF-1R protein or mRNA expression in NSCLC patients were evaluated using publicly available data from The Cancer Genome Atlas (TCGA). We found that membranous and cytoplasmic IGF-1R expressions were significantly associated with squamous cell carcinoma (SCC) in both of the TMAs. Analysis of the TCGA data revealed increased mRNA levels in NSCLC patients, which was significantly associated with reductions in overall survival (OS) (median survival 26.51 vs. 47.77 months, P = 0.017) and disease-free survival (median survival 17.44 vs. 37.65 months, P = 0.045) only in NSCLC patients with adenocarcinoma (ADC). These data suggest that IGF-1R is activated in patients with NSCLC, particularly those with SCC. IGF-1R mRNA expression is a potential prognostic factor in patients with NSCLC, especially those with ADC. Further studies are warranted to investigate the prognostic value of IGF-1R in NSCLC patients. PMID:25944691

  8. Stem cell factor receptor induces progenitor and natural killer cell-mediated cardiac survival and repair after myocardial infarction

    OpenAIRE

    Ayach, Bilal B.; Yoshimitsu, Makoto; Dawood, Fayez; Sun, Mei; Arab, Sara; Chen, Manyin; HIGUCHI, KOJI; Siatskas, Christopher; Lee, Paul; Lim, Hilda; Zhang, Jane; Cukerman, Eva; Stanford, William L.; Medin, Jeffrey A; Liu, Peter P.

    2006-01-01

    Inappropriate cardiac remodeling and repair after myocardial infarction (MI) predisposes to heart failure. Studies have reported on the potential for lineage negative, steel factor positive (c-kit+) bone marrow-derived hematopoetic stem∕progenitor cells (HSPCs) to repair damaged myocardium through neovascularization and myogenesis. However, the precise contribution of the c-kit signaling pathway to the cardiac repair process has yet to be determined. In this study, we sought to directly eluci...

  9. Hepatocyte growth factor reduces sensitivity to the epidermal growth factor receptor-tyrosine kinase inhibitor, gefitinib, in lung adenocarcinoma cells harboring wild-type EGFR

    Science.gov (United States)

    Yang, Hua; Wang, Rong; Peng, Shunli; Chen, Longhua; Li, Qi; Wang, Wei

    2016-01-01

    Epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) therapy is an option for lung cancers harboring wild-type EGFR when chemotherapeutic reagents have failed. In this study, we found that the EGFR-TKI, gefitinib, modestly suppressed proliferation of the lung cancer cell lines, A549 and H358, which both harbor wild-type EGFR. Treatment with hepatocyte growth factor (HGF) reduced the sensitivity to gefitinib, whereas sensitivity was restored by treatment with an HGF antibody, a MET inhibitor, or depletion of MET but not ErbB3 gene. Moreover, both PI3K/mTOR inhibitors and MEK inhibitors suppressed proliferation of A549 cells, whereas only PI3K/mTOR inhibitors effectively suppressed cell viability of EGFR mutant PC-9 cells. Our findings suggest that HGF reduced the gefitinib sensitivity through MET and downstream PI3K and MAPK pathways. Combined use of EGFR-TKI and MET inhibitors or inhibition of downstream signaling molecules might be a better second or third line choice for a group of patients with advanced lung cancer harboring wild-type EGFR. PMID:26919104

  10. Cigarette smoke and platelet-activating factor receptor dependent adhesion of Streptococcus pneumoniae to lower airway cells

    DEFF Research Database (Denmark)

    Grigg, Jonathan; Walters, Haydn; Sohal, Sukhwinder Singh;

    2012-01-01

    BACKGROUND: Exposure to cigarette smoke (CS) is associated with increased risk of pneumococcal infection. The mechanism for this association is unknown. We recently reported that the particulate matter from urban air simulates platelet-activating factor receptor (PAFR)-dependent adhesion of...... active-smokers by immunostaining. RESULTS: In A549 cells, CSE 1% increased pneumococcal adhesion (p<0.05 vs control), PAFR transcript level (p<0.01), and PAFR expression (p<0.01). Pneumococcal adhesion to A549 cells was attenuated by CV-3988 (p<0.001). CSE 1% stimulated pneumococcal adhesion to BEAS2-B...... cells and HBEpC (p<0.01 vs control). CSE 1% increased PAFR expression in BEAS2-B (p<0.01), and in HBEpC (p<0.05). Lung PAFR transcript level was increased in mice exposed to CS in vivo (p<0.05 vs room air). Active smokers (n=16) had an increased percentage of bronchial epithelium with PAFR...

  11. Characterization of fibroblast growth factor receptor 2 overexpression in the human breast cancer cell line SUM-52PE

    International Nuclear Information System (INIS)

    The fibroblast growth factor receptor (FGFR)2 gene has been shown to be amplified in 5-10% of breast cancer patients. A breast cancer cell line developed in our laboratory, SUM-52PE, was shown to have a 12-fold amplification of the FGFR2 gene, and FGFR2 message was found to be overexpressed 40-fold in SUM-52PE cells as compared with normal human mammary epithelial (HME) cells. Both human breast cancer (HBC) cell lines and HME cells expressed two FGFR2 isoforms, whereas SUM-52PE cells overexpressed those two isoforms, as well as several unique FGFR2 polypeptides. SUM-52PE cells expressed exclusively FGFR2-IIIb isoforms, which are high-affinity receptors for fibroblast growth factor (FGF)-1 and FGF-7. Differences were identified in the expression of the extracellular Ig-like domains, acid box and carboxyl termini, and several variants not previously reported were isolated from these cells. The FGFR family of receptor tyrosine kinases includes four members, all of which are highly alternatively spliced and glycosylated. For FGFR2, alternative splicing of the second half of the third Ig-like domain, involving exons IIIb and IIIc, is a mutually exclusive choice that affects ligand binding specificity and affinity [1,2,3]. It appears that the second half of the third Ig-like domain can dictate high affinity for FGF-2 or keratinocyte growth factor (KGF), whereas affinity for FGF-1 appears to remain the same [3]. Alternative splicing of the carboxyl terminus has been shown to involve at least two different exons that can produce at least three different variants. The C1-type and C2-type carboxyl termini are encoded by the same exon, and have two different splice acceptor sites, whereas the C3-type carboxyl terminus is encoded by a separate exon [4]. The biologic significance of the C1 carboxyl terminus, as compared with the shorter C3 variant found primarily in tumorigenic samples, has been studied in NIH3T3 transfection assays, in which C3 variants were able to produce

  12. Growth suppression by transforming growth factor beta 1 of human small-cell lung cancer cell lines is associated with expression of the type II receptor

    DEFF Research Database (Denmark)

    Nørgaard, P; Damstrup, L; Rygaard, K;

    1994-01-01

    observed in two cell lines expressing only type III receptor and in TGF-beta-r negative cell lines. In two cell lines expressing all three receptor types, growth suppression was accompanied by morphological changes. To evaluate the possible involvement of the retinoblastoma protein (pRb) in mediating the...

  13. Does it make sense to target one tumor cell chemotactic factor or its receptor when several chemotactic axes are involved in metastasis of the same cancer?

    Science.gov (United States)

    Ratajczak, Mariusz Z; Suszynska, Malwina; Kucia, Magda

    2016-12-01

    The major problem with cancer progression and anti-cancer therapy is the inherent ability of cancer cells to migrate and establish distant metastases. This ability to metastasize correlates with the presence in a growing tumor of cells with a more malignant phenotype, which express certain cancer stem cell markers. The propensity of malignant cells to migrate and their resistance to radio-chemotherapy somewhat mimics the properties of normal developmentally early stem cells that migrate during organogenesis in the developing embryo. In the past, several factors, including cell migration-promoting cytokines, chemokines, growth factors, bioactive lipids, extracellular nucleotides, and even H(+) ions, were found to influence the metastasis of cancer cells. This plethora of pro-migratory factors demonstrates the existence of significant redundancy in the chemoattractants for cancer cells. In spite of this obvious fact, significant research effort has been dedicated to demonstrating the crucial involvement of particular pro-metastatic factor-receptor axes and the development of new drugs targeting one receptor or one chemoattractant. Based on our own experience working with a model of metastatic rhabdomyosarcoma as well as the work of others, in this review we conclude that targeting a single receptor-ligand pro-metastatic axis will not effectively prevent metastasis and that we should seek other more effective therapeutic options. PMID:27510263

  14. Profile of differentially expressed genes mediated by the type III epidermal growth factor receptor mutation expressed in a small-cell lung cancer cell line

    DEFF Research Database (Denmark)

    Pedersen, M.W.; Andersen, Thomas Thykjær; Ørntoft, Torben Falck;

    2001-01-01

    understanding of how the EGFRvIII contributes to the malignant phenotype is of major importance for future therapy. The GeneChip Hu6800Set developed by Affymetrix was used to identify changes in gene expression caused by the expression of EGFRvIII. The cell line selected for the study was an EGF receptor...... negative small-cell-lung cancer cell line, GLC3, stably transfected with the EGFRvIII gene in a Tet-On system. By comparison of mRNA levels in EGFRvIII-GLC3 with those of Tet-On-GLC3, it was found that the levels of mRNAs encoding several transcription factors (ATF-3, JunD, and c-Myb), cell adhesion......Previous studies have shown a correlation between expression of the EGF receptor type III mutation (EGFRvIII) and a more malignant phenotype of various cancers including: non-small-cell lung cancer, glioblastoma multiforme, prostate cancer and breast cancer. Thus, a detailed molecular genetic...

  15. Integrative Network Analysis Combined with Quantitative Phosphoproteomics Reveals Transforming Growth Factor-beta Receptor type-2 (TGFBR2) as a Novel Regulator of Glioblastoma Stem Cell Properties.

    Science.gov (United States)

    Narushima, Yuta; Kozuka-Hata, Hiroko; Koyama-Nasu, Ryo; Tsumoto, Kouhei; Inoue, Jun-ichiro; Akiyama, Tetsu; Oyama, Masaaki

    2016-03-01

    Glioblastoma is one of the most malignant brain tumors with poor prognosis and their development and progression are known to be driven by glioblastoma stem cells. Although glioblastoma stem cells lose their cancer stem cell properties during cultivation in serum-containing medium, little is known about the molecular mechanisms regulating signaling alteration in relation to reduction of stem cell-like characteristics. To elucidate the global phosphorylation-related signaling events, we performed a SILAC-based quantitative phosphoproteome analysis of serum-induced dynamics in glioblastoma stem cells established from the tumor tissues of the patient. Among a total of 2876 phosphorylation sites on 1584 proteins identified in our analysis, 732 phosphorylation sites on 419 proteins were regulated through the alteration of stem cell-like characteristics. The integrative computational analyses based on the quantified phosphoproteome data revealed the relevant changes of phosphorylation levels regarding the proteins associated with cytoskeleton reorganization such as Rho family GTPase and Intermediate filament signaling, in addition to transforming growth factorreceptor type-2 (TGFBR2) as a prominent upstream regulator involved in the serum-induced phosphoproteome regulation. The functional association of transforming growth factorreceptor type-2 with stem cell-like properties was experimentally validated through signaling perturbation using the corresponding inhibitors, which indicated that transforming growth factorreceptor type-2 could play an important role as a novel cell fate determinant in glioblastoma stem cell regulation. PMID:26670566

  16. Evaluating the Prevalence of the Epidermal Growth Factor Receptor in Transitional Cell Carcinoma of Bladder and its Relationship With Other Prognostic Factors

    Science.gov (United States)

    Parvin, Mahmoud; Sabet-Rasekh, Parto; Hajian, Parastoo; Mohammadi Torbati, Peyman; Sabet-Rasekh, Parisa; Mirzaei, Hamidreza

    2016-01-01

    Background: The most common malignancy in the urinary system has been bladder cancer and the most predominant histologic subtype has been transitional cell carcinoma (TCC). There were many molecular risk factors, related with poor prognosis. One of these factors was expression of epidermal growth factor receptor (EGFR). Objectives: The aim of this study was to evaluate the prevalence of the epidermal growth factor receptor in transitional cell carcinoma of bladder and its relationship with other prognostic factors. Patients and Methods: This analytic descriptive study has performed with 61 patients with TCC of bladder after radical cystectomy whom have been hospitalized in Labbafinejad hospital in Tehran, Iran between 2007 and 2010. We have used Chi-square and t-test to analyze our data samples. Results: Records of 61 patients have studied. Fifty three of the total samples were positive for EGFR expression (86.9%). Fifty samples of these fifty-three belonged to men and three others were women’s samples (P = 0.46). Among the group with EGFR expression the results were as follows: 25 patients (47.2%) were 60 years old or less and 28 patients (52.8%) were older than 60 (P = 0.023), 16 patients (30.2%) had invasion to lamina properia, and the rest of them had invasion to deeper layers (P = 0.56). For most patients we could not determine the invasion of tumoral cells into the lymph nodes (Nx) (P = 0.067). Thirty four patients (64.2%) had not lymphovascular invasion (P = 0.44) and in forty three of patients (81.1%), perineural invasion have not seen (P = 0.23). Finally, 36 patients (67.9%) were grade 3 (P = 0.27). Conclusions: In this study we have concluded that most patients had EGFR positive expression. Also, except for the age, there was not any significant relation between expression of EGFR and the other prognostic factors such as, gender, invasion of the tumor into the layers, involving the lymph nodes, lymphovascular or perineural invasion, and grading. PMID

  17. Mouse Balb/c3T3 cell mutant with low epidermal growth factor receptor activity: induction of stable anchorage-independent growth by transforming growth factor β

    International Nuclear Information System (INIS)

    A mutant clone (MO-5) was originally isolated as a clone resistant to Na+/K+ ionophoric antibiotic monensin from mouse Balb/c3T3 cells. MO-5 was found to show low receptor-endocytosis activity for epidermal growth factor (EGF):binding activity for EGF in MO-5 was less than one tenth of that in Balb/c3T3. Anchorage-independent growth of MO-5 was compared to that of Balb/c3T3 when assayed by colony formation capacity in soft agar. Coadministration of EGF and TGF-β efficiently enhanced anchorage-independent growth of normal rat kidney (NRK) cells, but neither factor alone was competent to promote the anchorage-independent growth. The frequency of colonies appearing in soft agar of MO-5 or Balb/c3T3 was significantly enhanced by TGF-β while EGF did not further enhance that of MO-5 or Balb/c3T3. Colonies of Balb/c3T3 formed in soft agar in the presence of TGF-β showed low colony formation capacity in soft agar in the absence of TGF-β. Colonies of MO-5 formed by TGF-β in soft agar, however, showed high colony formation capacity in soft agar in the absence of TGF-β. Pretreatment of MO-5 with TGF-β induced secretion of TGF-β-like activity from the cells, while the treatment of Balb/c3T3 did not induce the secretion of a significant amount of TGF-β-like activity. The loss of EGF-receptor activity in the stable expression and maintenance of the transformed phenotype in MO-5 is discussed

  18. Insulin-like growth factors (IGFs) stimulate the release of alpha 1-antichymotrypsin and soluble IGF-II/mannose 6-phosphate receptor from MCF7 breast cancer cells.

    Science.gov (United States)

    Confort, C; Rochefort, H; Vignon, F

    1995-09-01

    The growth of hormone-responsive MCF7 human breast cancer cells is controlled by steroid hormones and growth factors. By metabolic labeling of cells grown in steroid- and growth factor-stripped serum conditions, we show that insulin-like growth factors (IGF-I and IGF-II) increase by approximately 5-fold the release of several proteins including cathepsin D, alpha 1-antichymotrypsin, and soluble forms of the multifunctional IGF-II/mannose 6-phosphate (M6P) receptor. Two soluble forms of IGF-II/M6P receptors were detected, one major (approximately 260 kilodaltons) and one minor (approximately 85 kilodaltons) that probably represents a proteolytic fragment of the larger soluble molecule. IGFs increased receptor release in a dose-dependent fashion with 50-60% of newly synthesized receptor released at 5-10 nM IGFs. The release of IGF-II/M6P receptors correlated with the levels of secreted cathepsin D in different human breast cancer cells or in rats stable transfectants that are constitutively expressing variable levels of human cathepsin D. IGFs had a stronger effect on IGF-II/M6P receptor release, whereas estradiol treatment preferentially enhanced the release of protease and antiprotease. We thus demonstrate that in human breast cancer cells, IGFs not only act as strong mitogens but also regulate release of alpha 1-antichymotrypsin, IGF-II/M6P-soluble receptor, and cathepsin D; three proteins that potentially regulate cell proliferation and/or invasion. PMID:7649082

  19. Soluble Tumor Necrosis Factor Receptor 1 Released by Skin-Derived Mesenchymal Stem Cells Is Critical for Inhibiting Th17 Cell Differentiation.

    Science.gov (United States)

    Ke, Fang; Zhang, Lingyun; Liu, Zhaoyuan; Yan, Sha; Xu, Zhenyao; Bai, Jing; Zhu, Huiyuan; Lou, Fangzhou; Cai, Wei; Sun, Yang; Gao, Yuanyuan; Wang, Hong; Wang, Honglin

    2016-03-01

    T helper 17 (Th17) cells play an important role in multiple sclerosis (MS) and its animal model experimental autoimmune encephalomyelitis (EAE). Th17 cell differentiation from naïve T cells can be induced in vitro by the cytokines transforming growth factor β1 and interleukin-6. However, it remains unclear whether other regulatory factors control the differentiation of Th17 cells. Mesenchymal stem cells (MSCs) have emerged as a promising candidate for inhibiting Th17 cell differentiation and autoimmune diseases. Despite the fact that several molecules have been linked to the immunomodulatory function of MSCs, many other key MSC-secreted regulators that are involved in inhibiting Th17 cell polarization are ill-defined. In this study, we demonstrated that the intraperitoneal administration of skin-derived MSCs (S-MSCs) substantially ameliorated the development of EAE in mice. We found that the proinflammatory cytokine tumor necrosis factor (TNF)-α, a key mediator in the pathophysiology of MS and EAE, was capable of promoting Th17 cell differentiation. Moreover, under inflammatory conditions, we demonstrated that S-MSCs produced high amounts of soluble TNF receptor 1 (sTNFR1), which binds TNF-α and antagonizes its function. Knockdown of sTNFR1 in S-MSCs decreased their inhibitory effect on Th17 cell differentiation ex vivo and in vivo. Thus, our data identified sTNFR1 and its target TNF-α as critical regulators for Th17 cell differentiation, suggesting a previously unrecognized mechanism for MSC therapy in Th17-mediated autoimmune diseases. PMID:26819253

  20. Expression of Epidermal Growth Factor Receptor and the association with Demographic and Prognostic Factors in Patients with Non-small Cell Lung Cancer

    Directory of Open Access Journals (Sweden)

    Reza Basiri

    2015-06-01

    Full Text Available Introduction: Growth, proliferation, survival, and differentiation are the prominent characteristics of cells, which are affected by cancer. Epidermal growth factor receptor (EGFR plays a pivotal role in the effective control of these features. Given the significance of EGFR signaling pathway in non-small cell lung cancer (NSCLC, EGFR expression is influential on these cell characteristics. In this paper, we studied EGFR expression and its association with demographic factors, clinicopathological features, and prognosis of NSCLC patients. Materials and Methods: In this retrospective cohort study which was done during 2009-12 at Ghaem Hospital, Mashhad, Iran. EGFR expression was evaluated in 96 patients with formalin-fixed, paraffin-embedded NSCLC tissues (43 adenocarcinomas, 48 squamous-cell carcinomas, and 5 large-cell carcinomas using immunohistochemistry (IHC. Data analysis was performed by SPSS version 20.0. Results: Out of 96 specimens, approximately 53% were classified as positive for EGFR expression. The study group consisted of 68% (N=65 male and 32% (N=31 female subjects, with the mean age of 61.1±9.03 years. There was no difference between EGFR-positive and EGFR-negative patients in terms of the overall survival rate (P=0.49. In addition, no association was observed between tumor histology and EGFR expression (P=0.08, while EGFR-positive adenocarcinoma (N=28, 29% was more prevalent compared to other subtypes of NSCLC. Moreover, there were no differences between tumor subtypes and the overall survival rate of the patients (P=0.21, and no association was found between EGFR expression and the patients’ demographic factors (e.g. age and gender. Conclusion: The results of this study indicated that EGFR expression could not be a prognostic marker in NSCLC patients; however, it seems that using standardized IHC scoring is likely to yield more reliable data in this regard.

  1. CD40-mediated tumor necrosis factor receptor-associated factor 3 signaling upregulates IL-4-induced germline Cepsilon transcription in a human B cell line.

    Science.gov (United States)

    Basaki, Yuji; Ikizawa, Koichi; Kajiwara, Keiichi; Yanagihara, Yukiyoshi

    2002-09-15

    Induction of germline C epsilon transcription in B cells by IL-4, which is a critical initiating step for IgE class switching, is enhanced by CD40 engagement. Although signaling by CD40 is initiated by the binding of tumor necrosis factor receptor-associated factor (TRAF) family members to its cytoplasmic domain, whether those TRAF family proteins mediate enhancement of germline Cepsilon transcription is not evident. We report here that CD40-induced TRAF3-dependent activation of mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) kinase 1 (MEK1) is involved in the upregulation of IL-4-driven germline C epsilon transcription in a human Burkitt's lymphoma B cell line, DG75. Among the six known TRAF proteins, TRAF2, 3, 5, and 6 associated with CD40 in an unstimulated state, and the levels of these four proteins were unaffected by anti-CD40 stimulation. Antisense oligodeoxynucleotide (ODN) for TRAF3 inhibited CD40-induced activation of MEK1-ERK pathway by decreasing expression of TRAF3 protein, but antisense ODNs for TRAF2, 5, and 6 were ineffective. Furthermore, CD40-mediated enhancement of IL-4-driven germline C epsilon transcription was inhibited by antisense ODN for TRAF3 and by a MEK1 inhibitor, PD98059. These results suggest that in DG75 cells, TRAF3-induced MEK1 activation may be involved in CD40-mediated upregulation of IL-4-driven germline C epsilon transcription. PMID:12220533

  2. Epidermal growth factor-receptor and radiation-induced signal transduction in human mammary and squamous carcinoma cells

    International Nuclear Information System (INIS)

    Purpose/Objective: The growth regulatory gene epidermal growth factor-receptor (EGF-R) and transforming growth factor-α (TGF-α) have been identified as radiation late response genes because of their permanent up-regulation after repeated radiation exposures. The steady-state mRNA levels of the same genes are up-regulated after single radiation exposures in the dose range of 2 - 5 Gy. This identifies EGF-R and TGF-α as genes critical in radiation responses and provides a unique opportunity to study the signal transduction cascade between immediate early and late responses. This study examines the role of protein tyrosine kinase receptors and immediate down-stream events in radiation-induced signal transduction. Material and Methods: For the analyses of EGF-R and TGF-α mRNA induction and EGF-R autophosphorylation MCF-7 mammary and A431 squamous carcinoma cells were grown in full medium without refeeding to 90% confluence within 4 days. EGF-R tyrosine phosphorylation (YP) after EGF exposures up to 60 min was compared to radiation-induced increases in EGF-R YP levels using YP-specific monoclonal antibody (Ab-5) for immune precipitation and immunoblotting with secondary antibodies. The phosphorylation pattern of EGF-R after radiation and EGF exposures was examined after metabolic labeling with 32P-ATP, immune precipitation and HPLC tryptic peptide mapping. The activation of phospholipase-C (PL-C), generating the secondary messengers (IP3) and diacylglycerol, was monitored by quantifying EGF- or radiation-induced IP3 production with a radio-immune assay kit. Results: Under the experimental conditions used, EGF induced dose-dependent 5- to 15-fold increases in autophosphorylation of EGF-R within 5 min of EGF exposure. The increased EGF-R YP levels were short-lived and reversed to less than base line levels within 60 min, most likely due to EGF-R turnover in the plasma membrane. Similar to EGF, single radiation exposures in the 1 to 4 Gy dose range induced an about 3

  3. Pharmacological targeting of the KIT growth factor receptor: a therapeutic consideration for mast cell disorders

    DEFF Research Database (Denmark)

    Jensen, Bettina Margrethe; Akin, C; Gilfillan, A M

    2008-01-01

    activated, accumulation of mast cells in tissues results in mastocytosis. Such dysregulated KIT activation is a manifestation of specific activating point mutations within KIT, with the human D816V mutation considered as a hallmark of human systemic mastocytosis. A number of other activating mutations in...... within these tissues, mast cell activation by antigen may also be amplified by SCF. Thus, KIT inhibitors may have potential application in multiple conditions linked to mast cells including systemic mastocytosis, anaphylaxis, and asthma. In this review, we discuss the role of KIT in the context of mast...

  4. MATRIX METALLOPROTEINS (MMP)-MEDIATED PHOSPHORYLATION OF THE EPIDERMAL GROWTH FACTOR RECEPTOR (EGFR) IN HUMAN AIRWAY EPITHELIAL CELLS (HAEC) EXPOSED TO ZINC (ZN)

    Science.gov (United States)

    Matrix Metalloproteinase (MMP)-Mediated Phosphorylation of The Epidermal Growth Factor Receptor (EGFR) in Human Airway Epithelial Cells (HAEC) Exposed to Zinc (Zn)Weidong Wu, James M. Samet, Robert Silbajoris, Lisa A. Dailey, Lee M. Graves, and Philip A. BrombergCenter fo...

  5. Insulin-like growth factor receptor 1 mRNA expression as a prognostic marker in advanced non-small cell lung cancer

    DEFF Research Database (Denmark)

    Vilmar, Adam; Santoni-Rugiu, Eric; Cillas, Jesus Garcia-Fon;

    2014-01-01

    BACKGROUND: The insulin-like growth factor 1 receptor (IGF1R) has yet to be established as a biomarker in non-small cell lung cancer (NSCLC) but could prove useful in customized chemotherapy. We explored its prognostic value using both quantitative real-time reverse transcriptase polymerase chain...

  6. Tumor Necrosis Factor Receptor 1 Expression Is Upregulated in Dendritic Cells in Patients with Chronic HCV Who Respond to Therapy

    Directory of Open Access Journals (Sweden)

    Raul Cubillas

    2010-01-01

    Full Text Available The present studies assessed the level of tumor necrosis factor receptor (TNFR expression in peripheral blood mononuclear cells (PBMCs subsets from patients with chronic HCV undergoing interferon /ribavirin-based therapy (Ifn/R. Methods. TNFR family member mRNA expression was determined using quantitative real-time PCR assays (RTPCRs in PBMC from 39 HCV+ patients and 21 control HCV− patients. Further subset analysis of HCV + patients (untreated (U, sustained virological responders (SVR, and nonresponders (NR/relapsers (Rel PBMC was performed via staining with anti-CD123, anti-CD33, anti-TNFR1 or via RTPCR for TNFR1 mRNA. Results. A similar level of TNFR1 mRNA in PBMC from untreated HCV+ genotype 1 patients and controls was noted. TNFR1 and TNFR2 mRNA levels in PBMC from HCV+ patients with SVR were statistically different than levels in HCV(− patients. A significant difference was noted between the peak values of TNFR1 of the CD123+ PBMC isolated from SVR and the NR/Rel. Conclusion. Upregulation of TNFR1 expression, occurring in a specific subset of CD123+ dendritic cells, appeared in HCV+ patients with SVR.

  7. Rapamycin Inhibits Lymphatic Endothelial Cell Tube Formation by Downregulating Vascular Endothelial Growth Factor Receptor 3 Protein Expression

    Directory of Open Access Journals (Sweden)

    Yan Luo

    2012-03-01

    Full Text Available Mammalian target of rapamycin (mTOR controls lymphangiogenesis. However, the underlying mechanism is not clear. Here we show that rapamycin suppressed insulin-like growth factor 1 (IGF-1- or fetal bovine serum (FBS-stimulated lymphatic endothelial cell (LEC tube formation, an in vitro model of lymphangiogenesis. Expression of a rapamycin-resistant and kinase-active mTOR (S2035T, mTOR-T, but not a rapamycin-resistant and kinase-dead mTOR (S2035T/D2357E, mTOR-TE, conferred resistance to rapamycin inhibition of LEC tube formation, suggesting that rapamycin inhibition of LEC tube formation is mTOR kinase activity dependent. Also, rapamycin inhibited proliferation and motility in the LECs. Furthermore, we found that rapamycin inhibited protein expression of VEGF receptor 3 (VEGFR-3 by inhibiting protein synthesis and promoting protein degradation of VEGFR-3 in the cells. Down-regulation of VEGFR-3 mimicked the effect of rapamycin, inhibiting IGF-1- or FBS-stimulated tube formation, whereas over-expression of VEGFR-3 conferred high resistance to rapamycin inhibition of LEC tube formation. The results indicate that rapamycin inhibits LEC tube formation at least in part by downregulating VEGFR-3 protein expression.

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

    International Nuclear Information System (INIS)

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

  9. Radiosensitization of epithelial growth factor receptor monoclonal antibody on lung adenocarcinoma cell line SPC-A-1

    International Nuclear Information System (INIS)

    Objective: To explore the radiosensitivity of C225 (cetuximab), an anti-epithelial growth factor receptor monoclonal antibody, which combined with irradiation against lung adenocarcinoma cell line SPC-A-1, and provide theoretical basis for clinical combined treatment in non-small lung cancer. Methods: SPC-A-1 were cultivated in vitro for 6 passages, and the SPC-A-1 in logarithmic growth phase were selected for experiment. The SPC-A-1 were divided into control group (PBS), irradiation group (4 Gy), C225 group (100 nmol ·L-1) and irradiation +C225 group (4 Gy + 100 nmol · L-1). The apoptosis of SPC-A-1 was observed by fluorescence microscope after Hoechst 33258 staining. SPC-A-1 were treated with different doses of 6-MV X-Rays including 0, 2, 4 and 8 Gy alone or together with C225 (100 nmol · L-1), 72 h after irradiation,the cells were divided into irradiation group and experimental group (irradiation + C22), the apototic rate was detected by flow cytometry (FCM). SPC-A-1 were divided into control group (PBS), C225 group (100 nmol · L-1), irradiation group (8 Gy) and irradiation + C225 group (8 Gy + 100 nmol · L-1), 48 h after irradiation, the cell cycle was determined by FCM. Results: After staining by Hoechst 33258, the number of apoptotic cells in irradiation + C225 group was significantly higher than those in irradiation group and C225 group. In apoptosis experiment, the apoptotic rate in experimental group was higher than that in irradiation group (P0+G1 phase was increased in C225 group (P0+G1 and G2+M phrases in irradiation +C225 group was increased (P0+G1 phases and inducing apoptosis. (authors)

  10. Antitumor activity of F90,an epidermal growth factor receptor tyrosine kinase inhibitor,on glioblastoma cell line SHG-44

    Institute of Scientific and Technical Information of China (English)

    LIU Fang-jun; GUI Song-bai; LI Chu-zhong; SUN Ze-lin; ZHANG Ya-zhuo

    2008-01-01

    Background Over-expression of epidermal growth factor receptor (EGFR) is thought to be related to cell proliferation,invasion,metastasis,resistance to chemoradiotherapy and poor prognosis of various human cancers.Forty percent to fifty percent of glioblastoma multiforme (GBM) possess deregulated EGFR,which may contribute to the aggressive and refractory course of GBM.Therefore,blockade of EGFR signal transduction may be a promising treatment strategy for GBM.Methods MIT assay,cell growth curve assay and tumor xenograft model were used to evaluate the antitumor activity of F90 against SHG-44 in vitro and in vivo.Western blot assay was applied to evaluate the expression of p-EGFR,p-ERK1,p-JNK,p-P38,Bcl2 and P53 proteins.Results F90 inhibited the cell proliferation in a dose-dependent manner in vitro.The growth of SHG-44 tumor xenografts was suppressed by F90 at a high dose level (100 mg.kg-1.d-1).Phosphorylation of EGFR and activated downstream signaling proteins,such as ERK1,JNK and P38,were found to be depressed after incubation with F90 for 48 hours in vitro.Down-regulated Bcl2 protein and up-regulated P53 protein were also observed.Conclueions The results demonstrate that F90 is effective in inhibiting the proliferation of SHG-44 cells in vitro and tumor growth in vivo,suggesting that F90 may be a new therapeutic option for treatment of GBM.

  11. Regulation of cyclooxygenase-2 (COX-2) expression in human pancreatic carcinoma cells by the insulin-like growth factor-I receptor (IGF-IR) system

    OpenAIRE

    STOELTZING, OLIVER; Liu, Wenbiao; Fan, Fan; Wagner, Christine; Stengel, Kathrin; Somcio, Ray J.; Reinmuth, Niels; Parikh, Alexander A; Hicklin, Daniel J.; Ellis, Lee M.

    2007-01-01

    Both the insulin-like growth factor-I receptor (IGF-IR) and cyclooxygenase-2 (COX-2) are frequently overexpressed in pancreatic cancer. We hypothesized that IGF-IR is directly involved in induction of COX-2 and sought to investigate signaling pathways mediating this effect. Pancreatic cancer cells (L3.6pl) were stably transfected with a dominant-negative receptor (IGF-IR DN) construct or empty vector (pcDNA). Cells were stimulated with IGF-I to determine activated signaling intermediates and ...

  12. Induction of a B-lymphocyte receptor for a T cell-replacing factor by the crosslinking of surface IgD.

    OpenAIRE

    Yaffe, L J; Finkelman, F D

    1983-01-01

    The observation that anti-immunoglobulin antibodies and T cell-replacing factor (TRF) have a synergistic effect on the stimulation of B lymphocytes to differentiate into antibody-secreting cells suggested to us the possibility that the crosslinking of B-cell surface immunoglobulin by antigen or anti-immunoglobulin antibody might induce the expression of a B-cell receptor for TRF. In order to test this possibility we studied whether spleen cells from mice injected with 400-800 micrograms of an...

  13. Epidermal Growth Factor Receptor and K-RAS status in two cohorts of squamous cell carcinomas

    International Nuclear Information System (INIS)

    With the availability of effective anti-EGFR therapies for various solid malignancies, such as non-cell small lung cancer, colorectal cancer and squamous cell carcinoma of the head and neck, the knowledge of EGFR and K-RAS status becomes clinically important. The aim of this study was to analyse EGFR expression, EGFR gene copy number and EGFR and K-RAS mutations in two cohorts of squamous cell carcinomas, specifically anal canal and tonsil carcinomas. Formalin fixed, paraffin-embedded tissues from anal and tonsil carcinoma were used. EGFR protein expression and EGFR gene copy number were analysed by means of immunohistochemistry and fluorescence in situ hybridisation. The somatic status of the EGFR gene was investigated by PCR using primers specific for exons 18 through 21. For the K-RAS gene, PCR was performed using exon 2 specific primers. EGFR immunoreactivity was present in 36/43 (83.7%) of anal canal and in 20/24 (83.3%) of tonsil squamous cell carcinomas. EGFR amplification was absent in anal canal tumours (0/23), but could be identified in 4 of 24 tonsil tumours. From 38 anal canal specimens, 26 specimens were successfully analysed for exon 18, 30 for exon 19, 34 for exon 20 and 30 for exon 21. No EGFR mutations were found in the investigated samples. Thirty samples were sequenced for K-RAS exon 2 and no mutation was identified. From 24 tonsil specimens, 22 were successfully analysed for exon 18 and all 24 specimens for exon 19, 20 and 21. No EGFR mutations were found. Twenty-two samples were sequenced for K-RAS exon 2 and one mutation c.53C > A was identified. EGFR mutations were absent from squamous cell carcinoma of the anus and tonsils, but EGFR protein expression was detected in the majority of the cases. EGFR amplification was seen in tonsil but not in anal canal carcinomas. In our investigated panel, only one mutation in the K-RAS gene of a tonsil squamous cell carcinoma was identified. This indicates that EGFR and K-RAS mutation analysis is not

  14. Targeting the epidermal growth factor receptor in non-small cell lung cancer cells: the effect of combining RNA interference with tyrosine kinase inhibitors or cetuximab

    Directory of Open Access Journals (Sweden)

    Chen Gang

    2012-03-01

    Full Text Available Abstract Background The epidermal growth factor receptor (EGFR is a validated therapeutic target in non-small cell lung cancer (NSCLC. However, current single agent receptor targeting does not achieve a maximal therapeutic effect, and some mutations confer resistance to current available agents. In the current study we have examined, in different NSCLC cell lines, the combined effect of RNA interference targeting the EGFR mRNA, and inactivation of EGFR signaling using different receptor tyrosine kinase inhibitors (TKIs or a monoclonal antibody cetuximab. Methods NSCLC cells (cell lines HCC827, H292, H358, H1650, and H1975 were transfected with EGFR siRNA and/or treated with the TKIs gefitinib, erlotinib, and afatinib, and/or with the monoclonal antibody cetuximab. The reduction of EGFR mRNA expression was measured by real-time quantitative RT-PCR. The down-regulation of EGFR protein expression was measured by western blot, and the proliferation, viability, caspase3/7 activity, and apoptotic morphology were monitored by spectrophotometry, fluorimetry, and fluorescence microscopy. The combined effect of EGFR siRNA and different drugs was evaluated using a combination index. Results EGFR-specific siRNA strongly inhibited EGFR protein expression almost equally in all cell lines and inhibited cell growth and induced cell apoptosis in all NSCLC cell lines studied, albeit with a different magnitude. The effects on growth obtained with siRNA was strikingly different from the effects obtained with TKIs. The effects of siRNA probably correlate with the overall oncogenic significance of the receptor, which is only partly inhibited by the TKIs. The cells which showed weak response to TKIs, such as the H1975 cell line containing the T790M resistance mutation, were found to be responsive to siRNA knockdown of EGFR, as were cell lines with downstream TKI resistance mutations. The cell line HCC827, harboring an exon 19 deletion mutation, was more than 10-fold

  15. Soluble Tumor Necrosis Factor Receptor: Enbrel (Etanercept) for Subacute Pulmonary Dysfunction Following Allogeneic Stem Cell Transplantation

    OpenAIRE

    Yanik, Gregory A.; Mineishi, Shin; Levine, John E.; Kitko, Carrie L.; White, Eric S.; Vander Lugt, Mark T.; Harris, Andrew C.; Braun, Thomas; Cooke, Kenneth R.

    2011-01-01

    Subacute lung disease, manifested as either obstructive (OLD) or restrictive (RLD) lung dysfunction, is a common complication following allogeneic stem cell transplantation. In each case, therapeutic options are limited, morbidity remains high, and long-term survival is poor. Between 2001 and 2008, 34 patients with noninfectious, obstructive (25) or RLD restrictive lung dysfunction (nine) received etanercept (Enbrel®, Amgen Inc.) 0.4 mg/kg/dose, subcutaneously, twice weekly, for 4 (group A) o...

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

    DEFF Research Database (Denmark)

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

    2008-01-01

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

  17. Inhibition of insulin-like growth factor-1 receptor signaling enhances growth-inhibitory and proapoptotic effects of gefitinib (Iressa) in human breast cancer cells

    OpenAIRE

    Camirand, Anne; Zakikhani, Mahvash; Young, Fiona; Pollak, Michael

    2005-01-01

    Introduction Gefitinib (Iressa, ZD 1839, AstraZeneca) blocks the tyrosine kinase activity of the epidermal growth factor receptor (EGFR) and inhibits proliferation of several human cancer cell types including breast cancer. Phase II clinical trials with gefitinib monotherapy showed an objective response of 9 to 19% in non-small-cell lung cancer patients and less than 10% for breast cancer, and phase III results have indicated no benefit of gefitinib in combination with chemotherapy over chemo...

  18. Rabies Virus Ocular Disease: T-Cell-Dependent Protection Is under the Control of Signaling by the p55 Tumor Necrosis Factor Alpha Receptor, p55TNFR

    OpenAIRE

    Camelo, Serge; Castellanos, Jaime; Lafage, Mireille; Lafon, Monique

    2001-01-01

    Following brain infection, the Challenge Virus Standard strain of rabies virus infects the retina. Rabies virus ocular infection induces the infiltration of neutrophils and predominantly T cells into the eye. The role of tumor necrosis factor alpha (TNF-α)-lymphotoxin signaling in the control of rabies virus ocular infection and inflammatory cell infiltration was assessed using mice lacking the p55 TNF-α receptor (p55TNFR−/− mice). The incidence of ocular disease and the intensity of retinal ...

  19. Complete remission through icotinib treatment in Non-small cell lung cancer epidermal growth factor receptor mutation patient with brain metastasis: A case report

    OpenAIRE

    Wang Tao; Wang Ruimin; Dong Zhouhuan; Liang Naichao; Chang Ping

    2016-01-01

    Brain metastasis (BM) has been universally recognized as a poor prognostic factor in non-small cell lung cancer (NSCLC). Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) have shown efficacy in treating BM with an EGFR mutation. This paper reports a case of BM patient with EGFR-mutated NSCLC. According to the findings, a complete remission (CR) of the BM was achieved by icotinib treatment without conducting a radiotherapy, which was followed by a resection of the prima...

  20. Intermittent hypoxia induces the proliferation of rat vascular smooth muscle cell with the increases in epidermal growth factor family and erbB2 receptor

    Energy Technology Data Exchange (ETDEWEB)

    Kyotani, Yoji, E-mail: cd147@naramed-u.ac.jp [Department of Pharmacology, Nara Medical University School of Medicine, Kashihara 634-8521 (Japan); Department of Pharmacy, Nara Medical University Hospital, Kashihara 634-8522 (Japan); Ota, Hiroyo [Second Department of Internal Medicine, Nara Medical University School of Medicine, Kashihara 634-8522 (Japan); Department of Biochemistry, Nara Medical University School of Medicine, Kashihara 634-8521 (Japan); Itaya-Hironaka, Asako; Yamauchi, Akiyo; Sakuramoto-Tsuchida, Sumiyo [Department of Biochemistry, Nara Medical University School of Medicine, Kashihara 634-8521 (Japan); Zhao, Jing; Ozawa, Kentaro; Nagayama, Kosuke; Ito, Satoyasu [Department of Pharmacology, Nara Medical University School of Medicine, Kashihara 634-8521 (Japan); Takasawa, Shin [Department of Biochemistry, Nara Medical University School of Medicine, Kashihara 634-8521 (Japan); Kimura, Hiroshi [Second Department of Internal Medicine, Nara Medical University School of Medicine, Kashihara 634-8522 (Japan); Uno, Masayuki [Department of Pharmacy, Nara Medical University Hospital, Kashihara 634-8522 (Japan); Yoshizumi, Masanori [Department of Pharmacology, Nara Medical University School of Medicine, Kashihara 634-8521 (Japan)

    2013-11-15

    Obstructive sleep apnea is characterized by intermittent hypoxia (IH), and associated with cardiovascular diseases, such as stroke and heart failure. These cardiovascular diseases have a relation to atherosclerosis marked by the proliferation of vascular smooth muscle cells (VSMCs). In this study, we investigated the influence of IH on cultured rat aortic smooth muscle cell (RASMC). The proliferation of RASMC was significantly increased by IH without changing the level of apoptosis. In order to see what induces RASMC proliferation, we investigated the influence of normoxia (N)-, IH- and sustained hypoxia (SH)-treated cell conditioned media on RASMC proliferation. IH-treated cell conditioned medium significantly increased RASMC proliferation compared with N-treated cell conditioned medium, but SH-treated cell conditioned medium did not. We next investigated the epidermal growth factor (EGF) family as autocrine growth factors. Among the EGF family, we found significant increases in mRNAs for epiregulin (ER), amphiregulin (AR) and neuregulin-1 (NRG1) in IH-treated cells and mature ER in IH-treated cell conditioned medium. We next investigated the changes in erbB family receptors that are receptors for ER, AR and NRG1, and found that erbB2 receptor mRNA and protein expressions were increased by IH, but not by SH. Phosphorylation of erbB2 receptor at Tyr-1248 that mediates intracellular signaling for several physiological effects including cell proliferation was increased by IH, but not by SH. In addition, inhibitor for erbB2 receptor suppressed IH-induced cell proliferation. These results provide the first demonstration that IH induces VSMC proliferation, and suggest that EGF family, such as ER, AR and NRG1, and erbB2 receptor could be involved in the IH-induced VSMC proliferation. - Highlights: ●In vitro system for intermittent hypoxia (IH) and sustained hypoxia (SH). ●IH, but not SH, induces the proliferation of rat vascular smooth muscle cell. ●Epiregulin m

  1. Human GATA-3: a lineage-restricted transcription factor that regulates the expression of the T cell receptor alpha gene.

    OpenAIRE

    Ho, I C; Vorhees, P; Marin, N; Oakley, B K; Tsai, S F; Orkin, S H; Leiden, J. M.

    1991-01-01

    In addition to its role in the recognition of foreign antigens, the T cell receptor (TCR) alpha gene serves as a model system for studies of developmentally-regulated, lineage-specific gene expression in T cells. TCR alpha gene expression is restricted to cells of the TCR alpha/beta+ lineage, and is controlled by a T cell-specific transcriptional enhancer located 4.5 kb 3' to the C alpha gene segment. The TCR alpha enhancer contains four nuclear protein binding sites called T alpha 1-T alpha ...

  2. Association between genetic variations in tumor necrosis factor receptor genes and survival of patients with T-cell lymphoma

    Institute of Scientific and Technical Information of China (English)

    Kan Zhai; Jiang Chang; Chen Wu; Ning Lu; Li-Ming Huang; Tong-Wen Zhang; Dian-Ke Yu; Wen Tan; Dong-Xin Lin

    2012-01-01

    The prognosis of T-cell lymphoma (TCL) has been shown to be associated with the clinical characteristics of patients.However,there is little knowledge of whether genetic variations also affect the prognosis of TCL.This study investigated the associations between single nucleotide polymorphisms (SNPs) in tumor necrosis factor receptor superfamily (TNFRSF) genes and the survival of patients with TCL.A total of 38tag SNPs in 18 TNFRSF genes were genotyped using Sequenom platform in 150 patients with TCL.Kaplan-Meier survival estimates were plotted and significance was assessed using log-rank tests.Cox proportional hazard models were used to analyze each of these 38 SNPs with adjustment for covariates that might influence patient survival,including sex and international prognostic Index score.Hazard ratios (HRs) and their 95% confidence intervals (Cls) were calculated.Among the 38 SNPs tested,3 were significantly associated with the survival of patients with TCL.These SNPs were located at LTβR (rs3759333C>T) and TNFRSF17 (rs2017662C >T and rs2071336C>T).The 5-year survival rates were significantly different among patients carrying different genotypes and the HRs for death between the different genotypes ranged from 0.45 to 2.46.These findings suggest that the SNPs in TNFRSF genes might be important determinants for the survival of TCL patients.

  3. Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitors for Elderly Patients with Advanced Non-Small Cell Lung Cancer

    Directory of Open Access Journals (Sweden)

    A. Zaniboni

    2010-01-01

    Full Text Available Lung cancer is the leading cause of cancer-related mortality in both men and women and approximately 219,440 new cases of nonsmall cell lung cancer (NSCLC were estimated to occur in the USA in 2009, which caused 159,390 NSCLC-related deaths. More than 50% of cases of advanced NSCLC are diagnosed in patients older than age 65, and recent Surveillance Epidemiology and End Results (SEERs data suggest that the median age at diagnosis is 70 years. Until recently, the disease has been undertreated in this patient population, with a perception among many clinicians that elderly patients do not tolerate chemotherapy or radiotherapy. So, single agent chemotherapy is the recommended approach by the ASCO and International Expert Panels in unselected patients. The introduction of novel targeted therapies, such as Epidermal Growth Factor Receptor (EGFR Tyrosine Kinase Inhibitors (TKIs which improved survival versus placebo in patients who had previously failed on chemotherapy, gives clinicians new, effective, and better tolerated options to consider when treating NSCLC in elderly patients. This paper describes the advances of EGFR TKIs for elderly patients with advanced NSCLC.

  4. Epidermal growth factor receptor inhibitors in non-small cell lung cancer: current status and future perspectives

    Directory of Open Access Journals (Sweden)

    Mauro Zükin

    2012-04-01

    Full Text Available Two classes of epidermal growth factor receptor (EGFR inhibitors are currently available for clinical use: tyrosine-kinase inhibitors (TKIs and monoclonal antibodies. The introduction of pharmacological agents that are able to inhibit EGFR represents an important step in the management of patients with advanced non-small cell lung cancer (NSCLC, the leading cause of cancer death worldwide. The use of EGFR inhibitors has not only led to meaningful therapeutic gains for patients, but has also expanded our knowledge about the disease itself, as it is now recognized that activating mutations of EGFR play a pathogenetic role in NSCLC, especially in adenocarcinoma, patients who never smoked or former light smokers, females, and Asian individuals. Patients with NSCLC and one or more of these features are more likely to harbor tumors with EGFR mutations, and hence to respond to TKIs, than individuals without these features. Currently, TKIs are considered by many as the treatment of first choice in both the first- and second-line treatment of patients with clinical or molecular predictors of therapeutic benefit, and chemotherapy is a second option in these cases, especially when activating mutations of EGFR are present. Moreover, TKIs and anti-EGFR antibodies may be used in other settings, and their therapeutic role in NSCLC is clearly expanding. However, despite an initially successful treatment course, patients with advanced NSCLC eventually develop resistance to TKIs; and novel agents that hold promise for the future include irreversible EGFR inhibitors with activity against resistance-conferring EGFR mutations.

  5. Stem cell factor receptor (c-KIT) codon 816 mutations predict development of bilateral testicular germ-cell tumors

    NARCIS (Netherlands)

    L.H.J. Looijenga (Leendert); R.J.H.L.M. van Gurp (Ruud); J.M. Nesland; J.A. Stoop (Hans); A.J.M. Gillis (Ad); C.A. de Gouveia Brazao; E. Olah; J.W. Oosterhuis (Wolter); R.F.A. Weber (Robert); W.J. Kirkels (Wim); G. Lajos; S.D. Fossa (Sophie); H. de Leeuw; M. van Oorschot; M.M. von Lindern (Marieke); T.B. van Dijk (Thamar); P.J.M. Valk (Peter)

    2003-01-01

    textabstractTesticular germ-cell tumors (TGCTs) of adolescents and adults originate from intratubular germ cell neoplasia (ITGCN), which is composed of the malignant counterparts of embryonal germ cells. ITGCN cells are characterized, among others, by the presence of stem cell fact

  6. Glioma-Derived Platelet-Derived Growth Factor-BB Recruits Oligodendrocyte Progenitor Cells via Platelet-Derived Growth Factor Receptor-α and Remodels Cancer Stroma.

    Science.gov (United States)

    Zheng, Yang; Yamamoto, Seiji; Ishii, Yoko; Sang, Yang; Hamashima, Takeru; Van De, Nguyen; Nishizono, Hirofumi; Inoue, Ran; Mori, Hisashi; Sasahara, Masakiyo

    2016-05-01

    Glioma is an aggressive and incurable disease, and is frequently accompanied by augmented platelet-derived growth factor (PDGF) signaling. Overexpression of PDGF-B ligand characterizes a specific subclass of glioblastoma multiforme, but the significance of the ligand remains to be elucidated. For this end, we implanted a glioma-cell line transfected with PDGF-BB-overexpressing vector (GL261-PDGF-BB) or control vector (GL261-vector) into wild-type mouse brain, and examined the effect of glioma-derived PDGF on the tumor microenvironment. The volume of GL261-PDGF-BB rapidly increased compared with GL261-vector. Recruitment of many PDGF receptor (PDGFR)-α and Olig2-positive oligodendrocyte precursor cells and frequent hemorrhages were observed in GL261-PDGF-BB but not in GL261-vector. We then implanted GL261-PDGF-BB into the mouse brain with and without Pdgfra gene inactivation, corresponding to PDGFRα-knockout (KO) and Flox mice, respectively. The recruitment of oligodendrocyte precursor cells was largely suppressed in PDGFRα-KO than in Flox, whereas the volume of GL261-PDGF-BB was comparable between the two genotypes. Frequent hemorrhage and increased IgG-leakage were associated with aberrant vascular structures within the area where many recruited oligodendrocyte precursor cells accumulated in Flox. In contrast, these vascular phenotypes were largely normalized in PDGFRα-KO. Increased matrix metalloproteinase-9 in recruited oligodendrocyte precursor cells and decreased claudin-5 in vasculature may underlie the vascular abnormality. Glioma-derived PDGF-B signal induces cancer stroma characteristically seen in high-grade glioma, and should be therapeutically targeted to improve cancer microenvironment. PMID:26945107

  7. Infliximab therapy balances regulatory T cells, tumour necrosis factor receptor 2 (TNFR2) expression and soluble TNFR2 in sarcoidosis.

    Science.gov (United States)

    Verwoerd, A; Hijdra, D; Vorselaars, A D M; Crommelin, H A; van Moorsel, C H M; Grutters, J C; Claessen, A M E

    2016-08-01

    Sarcoidosis is a systemic granulomatous disease of unknown aetiology that most commonly affects the lungs. Although elevated levels of regulatory T cells (Tregs ) have been reported, the extent to which they play a role in sarcoidosis pathogenesis remains unclear. Tumour necrosis factor (TNF) is thought to be one of the driving forces behind granuloma formation, illustrated by the efficacy of infliximab in severe sarcoidosis. Tregs express TNF receptor 2 (TNFR2) highly. Here, we examined the influence of infliximab therapy on Tregs and (soluble) TNFR2 levels in sarcoidosis, and correlated these with response to therapy. We observed that relative frequencies of Tregs were significantly higher in patients (n = 54) compared to healthy controls (n = 26; median 6·73 versus 4·36%; P Tregs was increased significantly in patients versus controls (99·4 versus 96·2%; P = 0·031), and also in responders to therapy versus non-responders (99·6 versus 97·3%; P = 0·012). Furthermore, baseline soluble TNFR2 (sTNFR2) was higher in responders than in non-responders (mean 174 versus 107 pg/ml; P = 0·015). After treatment, responders showed a significant reduction in sTNFR2 levels in peripheral blood (-44·7 pg/ml; P Treg frequencies and TNFR2 expression on Tregs are increased in sarcoidosis, followed by a decline during infliximab therapy, suggesting a pathophysiological role of this T cell subset. Interestingly, sTNFR2 levels at baseline differed significantly between responders and non-responders, making it a potential marker in predicting which patients might benefit from infliximab. PMID:27158798

  8. Fibroblast growth factor receptor 1 amplification in non-small cell lung cancer by quantitative real-time PCR.

    Directory of Open Access Journals (Sweden)

    Shirish M Gadgeel

    Full Text Available INTRODUCTION: Amplification of the fibroblast growth factor receptor 1 (FGFR1 gene has been described in tumors of non-small-cell lung cancer (NSCLC patients. Prior reports showed conflicting rates of amplification frequency and clinical relevance. MATERIALS AND METHODS: We developed a reliable real-time quantitative PCR assay to assess the frequency of FGFR1 amplification and assessed the optimal cutoff level of amplification for clinical application. RESULTS: In a training cohort of 203 NSCLCs, we established that a 3.5-fold amplification optimally divided patients into groups with different survival rates with a clear threshold level. Those with FGFR1 amplification levels above 3.5-fold had an inferior survival. These data were confirmed in a validation cohort of 142 NSCLC. After adjusting for age, sex, performance status, stage, and histology, patients with FGFR1 amplification levels above 3.5 fold had a hazard ratio of 2.91 (95% CI- 1.14, 7.41; pvalue-0.025 for death in the validation cohort. The rates of FGFR1 amplification using the cutoff level of 3.5 were 5.1% in squamous cell and 4.1% in adenocarcinomas. There was a non-significant trend towards higher amplifications rates in heavy smokers (> 15 pack-years of cigarette consumption as compared to light smokers. DISCUSSION: Our data suggest that a 3.5-fold amplification of FGFR1 is of clinical importance in NSCLC. Our cutpoint analysis showed a clear threshold effect for the impact of FGFR1 amplification on patients' survival, which can be used as an initial guide for patient selection in trials assessing efficacy of novel FGFR inhibitors.

  9. Baseline and Trend of Lymphocyte-to-Monocyte Ratio as Prognostic Factors in Epidermal Growth Factor Receptor Mutant Non-Small Cell Lung Cancer Patients Treated with First-Line Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitors.

    Directory of Open Access Journals (Sweden)

    Yu-Mu Chen

    Full Text Available Patients with early-stage lung cancer who have a high baseline lymphocyte-to-monocyte ratio (LMR have a favorable prognosis. However, the prognostic significance of LMR in patients with advanced-stage EGFR-mutant non-small cell lung cancer (NSCLC receiving first-line epidermal growth factor receptor (EGFR-tyrosine kinase inhibitors (TKIs has not been established. We conducted a retrospective analysis to investigate the influence of LMR on clinical outcomes including progression-free survival (PFS and overall survival (OS in EGFR-mutant patients with NSCLC.Of 1310 lung cancer patients diagnosed between January 2011 and October 2013, 253 patients receiving first-line EGFR-TKIs for EGFR-mutant NSCLC were included. The cut-off values for baseline and the 1-month-to-baseline ratio of LMR (MBR, determined by using receiver operating characteristic curves, were 3.29 and 0.63, respectively. Patients were divided into 3 prognostic groups: high LMR and MBR, high LMR or MBR, and low LMR and MBR.The mean patient age was 65.2 years, and 41% were men. The median PFS and OS were 10.3 and 22.0 months, respectively. The PFS in patients with high LMR and MBR, high LMR or MBR, and low LMR and MBR were 15.4, 7.1, and 2.0 months, respectively (p < 0.001, whereas the OS were 32.6, 13.7, and 5.1 months, respectively (p < 0.001.A combination of baseline and trend of LMR can be used to identify patients with a high mortality risk in EGFR-mutant NSCLC patients receiving first-line EGFR-TKIs.

  10. Effect of The Receptor Activator of Nuclear Factor кB and RANK Ligand on In Vitro Differentiation of Cord Blood CD133+ Hematopoietic Stem Cells to Osteoclasts

    Science.gov (United States)

    Kalantari, Nasim; Abroun, Saeid; Soleimani, Masoud; Kaviani, Saeid; Azad, Mehdi; Eskandari, Fatemeh; Habibi, Hossein

    2016-01-01

    Objective Receptor activator of nuclear factor-kappa B ligand (RANKL) appears to be an osteoclast-activating factor, bearing an important role in the pathogenesis of multiple myeloma. Some studies demonstrated that U-266 myeloma cell line and primary myeloma cells expressed RANK and RANKL. It had been reported that the expression of myeloid and monocytoid markers was increased by co-culturing myeloma cells with hematopoietic stem cells (HSCs). This study also attempted to show the molecular mechanism of RANK and RANKL on differentiation capability of human cord blood HSC to osteoclast, as well as expression of calcitonin receptor (CTR) on cord blood HSC surface. Materials and Methods In this experimental study, CD133+ hematopoietic stem cells were isolated from umbilical cord blood and cultured in the presence of macrophage colony-stimulating factor (M-CSF) and RANKL. Osteoclast differentiation was characterized by using tartrate-resistant acid phosphatase (TRAP) staining, giemsa staining, immunophenotyping, and reverse transcription-polymerase chain reaction (RT-PCR) assay for specific genes. Results Hematopoietic stem cells expressed RANK before and after differentiation into osteoclast. Compared to control group, flow cytometric results showed an increased expression of RANK after differentiation. Expression of CTR mRNA showed TRAP reaction was positive in some differentiated cells, including osteoclast cells. Conclusion Presence of RANKL and M-CSF in bone marrow could induce HSCs differentiation into osteoclast. PMID:27602313

  11. miR-223 enhances the sensitivity of non-small cell lung cancer cells to erlotinib by targeting the insulin-like growth factor-1 receptor.

    Science.gov (United States)

    Zhao, Feng-Yi; Han, Jing; Chen, Xie-Wan; Wang, Jiang; Wang, Xu-Dong; Sun, Jian-Guo; Chen, Zheng-Tang

    2016-07-01

    Lung cancer is the leading cause of cancer-related fatalities worldwide, and non-small cell lung cancer (NSCLC) is the main pathological type. MicroRNAs (miRNAs or miRs) are a class of small non-coding RNAs, which are involved in tumor initiation and progression. miR‑223 is a tumor suppressor miRNA that has been reported in various types of cancer, including lung cancer. In the present study, to characterize the biological behavior of miR‑223 in NSCLC, we established an miR‑223 overexpression model in erlotinib-resistant PC‑9 (PC‑9/ER) cells by infection with lentivirus to induce the overexpression of miR‑223. As a result, miR‑223 enhanced the sensitivity of the PC‑9/ER cells to erlotinib by inducing apoptosis in vitro. Additionally, in vivo experiments were performed using nude mice which were injected with the cancer cells [either the PC‑9 (not resistant), PC‑9/ER, or the PC‑9/ER cells infected with miR‑223)]. We found that the tumor volumes were reduced in the rats injected with the cells infected with miR‑223. To further explore the underlying mechanisms, reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and western blot analysis were used to identify the target molecules of miR‑223. miR‑223 was demonstrated to act as a local regulator of insulin-like growth factor-1 receptor (IGF-1R) in the acquired resistance to tyrosine kinase inhibitors (TKIs). Notably, the οverexpression of IGF-1R in NSCLC was downregulated by miR‑223, and the activation of Akt/S6, the downstream pathway, was also inhibited. The inhibition of IGF-1R by miR‑223 was attenuated by exogenous IGF-1 expression. Therefore, miR‑223 may regulate the acquired resistance of PC‑9/ER cells to erlotinib by targeting the IGF-1R/Akt/S6 signaling pathway. The overexpression of miR‑223 may partially reverse the acquired resistance to epidermal growth factor receptor-TKIs, thus, providing a potential therapeutic strategy for TKI

  12. Fibronectin type III (FN3) modules of the neuronal cell adhesion molecule L1 interact directly with the fibroblast growth factor (FGF) receptor

    DEFF Research Database (Denmark)

    Kulahin, Nikolaj; Li, Shizhong; Hinsby, Anders Mørkeberg;

    2008-01-01

    The neuronal cell adhesion molecule (CAM) L1 promotes axonal outgrowth, presumably through an interaction with the fibroblast growth factor receptor (FGFR). The present study demonstrates a direct interaction between L1 fibronectin type III (FN3) modules I-V and FGFR1 immunoglobulin (Ig) modules II...... receptor phosphorylation, and this resulted in the induction of differentiation of primary neurons, reflected by neurite outgrowth. Furthermore, ATP modulated L1-induced neuronal differentiation and FGFR1 phosphorylation through regulation of the L1-FGFR1 interaction....

  13. Non-small-cell lung cancer cells combat epidermal growth factor receptor tyrosine kinase inhibition through immediate adhesion-related responses

    Directory of Open Access Journals (Sweden)

    Wang HY

    2016-05-01

    Full Text Available Hsian-Yu Wang,1,2 Min-Kung Hsu,3,4 Kai-Hsuan Wang,1 Ching-Ping Tseng,2,4 Feng-Chi Chen,3,4 John T-A Hsu1,4 1Institute of Biotechnology and Pharmaceutical Research, National Health Research Institutes (NHRI, Zhunan, Miaoli County, 2Institute of Molecular Medicine and Bioengineering, National Chiao Tung University (NCTU, Hsinchu, 3Division of Biostatistics and Bioinformatics, Institute of Population Health Sciences, National Health Research Institutes (NHRI, Zhunan, Miaoli County, 4Department of Biological Science and Technology, National Chiao Tung University (NCTU, Hsinchu, Taiwan, Republic of China Background: Epidermal growth factor receptor (EGFR tyrosine kinase inhibitors (TKIs, such as gefitinib, erlotinib, and afatinib, have greatly improved treatment efficacy in non-small cell lung cancer (NSCLC patients with drug-sensitive EGFR mutations. However, in some TKI responders, the benefits of such targeted therapies are limited by the rapid development of resistance, and strategies to overcome this resistance are urgently needed. Studies of drug resistance in cancer cells typically involve long term in vitro induction to obtain stably acquired drug-resistant cells followed by elucidation of resistance mechanisms, but the immediate responses of cancer cells upon drug treatment have been ignored. The aim of this study was to investigate the immediate responses of NSCLC cells upon treatment with EGFR TKIs.Results: Both NSCLC cells, ie, PC9 and H1975, showed immediate enhanced adhesion-related responses as an apoptosis-countering mechanism upon first-time TKI treatment. By gene expression and pathway analysis, adhesion-related pathways were enriched in gefitinib-treated PC9 cells. Pathway inhibition by small-hairpin RNAs or small-molecule drugs revealed that within hours of EGFR TKI treatment, NSCLC cells used adhesion-related responses to combat the drugs. Importantly, we show here that the Src family inhibitor, dasatinib, dramatically inhibits

  14. Antigen and transforming growth factor beta receptors contribute to long term functional and phenotypic heterogeneity of memory CD8 T cells.

    Directory of Open Access Journals (Sweden)

    Yinghong eHu

    2013-08-01

    Full Text Available Pathogen-specific CD8 T cells provide a mechanism for selectively eliminating host cells that are harboring intracellular pathogens. The pathogens are killed when lytic molecules are injected into the cytoplasm of the infected cells and begin an apoptotic cascade. Activated CD8 T cells also release large quantities of proinflammatory cytokines that stimulate other immune cells in the local vicinity. As the alveoli are extraordinarily sensitive to cytokine induced damage, multiple layers of immune regulation limit the activities of immune cells that enter the lungs. These mechanisms include receptor-mediated signaling pathways in CD8 T cells that respond to peptide antigens and transforming growth factor-beta. Both pathways influence the functional and phenotypic properties of long-lived CD8 T cells populations in peripheral and lymphoid tissues.

  15. An active form of Vav1 induces migration of mammary epithelial cells by stimulating secretion of an epidermal growth factor receptor ligand

    Directory of Open Access Journals (Sweden)

    Moores Sheri L

    2006-05-01

    Full Text Available Abstract Background Vav proteins are guanine nucleotide exchange factors (GEF for Rho family GTPases and are activated following engagement of membrane receptors. Overexpression of Vav proteins enhances lamellipodium and ruffle formation, migration, and cell spreading, and augments activation of many downstream signaling proteins like Rac, ERK and Akt. Vav proteins are composed of multiple structural domains that mediate their GEF function and binding interactions with many cellular proteins. In this report we examine the mechanisms responsible for stimulation of cell migration by an activated variant of Vav1 and identify the domains of Vav1 required for this activity. Results We found that expression of an active form of Vav1, Vav1Y3F, in MCF-10A mammary epithelial cells increases cell migration in the absence or presence of EGF. Vav1Y3F was also able to drive Rac1 activation and PAK and ERK phosphorylation in MCF-10A cells in the absence of EGF stimulation. Mutations in the Dbl homology, pleckstrin homology, or cysteine-rich domains of Vav1Y3F abolished Rac1 or ERK activation in the absence of EGF and blocked the migration-promoting activity of Vav1Y3F. In contrast, mutations in the SH2 and C-SH3 domains did not affect Rac activation by Vav1Y3F, but reduced the ability of Vav1Y3F to induce EGF-independent migration and constitutive ERK phosphorylation. EGF-independent migration of MCF-10A cells expressing Vav1Y3F was abolished by treatment of cells with an antibody that prevents ligand binding to the EGF receptor. In addition, conditioned media collected from Vav1Y3F expressing cells stimulated migration of parental MCF-10A cells. Lastly, treatment of cells with the EGF receptor inhibitory antibody blocked the Vav1Y3F-induced, EGF-independent stimulation of ERK phosphorylation, but had no effect on Rac1 activation or PAK phosphorylation. Conclusion Our results indicate that increased migration of active Vav1 expressing cells is dependent on

  16. Influence of baicalin on the expression of receptor activator of nuclear factor-κB ligand and osteoprotegerin in human periodontal ligament cells

    Institute of Scientific and Technical Information of China (English)

    Yue Chen

    2009-01-01

    Objective To study the effect of baicalin on the expression of receptor activator of nuclear factor-κB ligand (RANKL) and osteoprotegerin (OPG) in cultured human periodontal ligament (HPDL) cells. Methods Small interfering RNA (siRNA) eukaryotic expression vector targeted transforming growth factor βⅡ receptor (TGF-β RⅡ) was constructed and transfected into T cells. HPDL cells with T cells transfected with siRNA or not were placed in the culture medium that had been added with lipopolysaccharide (LPS) and baicalin. The obtained solution was divided into six groups according to the components (group Ⅰ: HPDL cells+LPS+T cells transfected with siRNA1+baicalin;group Ⅱ: HPDL cells+LPS+T cells transfected with siRNA1; group Ⅲ: HPDL cells+LPS+T cells+baicalin; group Ⅳ: HPDL cells+LPS+T cells; group Ⅴ: HPDL cells+baicalin; group Ⅵ: HPDL cells) and was cultured for 48 hours. RT-PCR was used to observe the effect of baicalin on the expression of OPG-RANKL in HPDL cells. Results The ratio of RANKL/OPG in group Ⅰ was lower than that in group Ⅱ (P<0.01) and higher than that in group Ⅲ (P<0.01); The ratio of RANKL/OPG in gronp Ⅲ was lower than that in group Ⅳ (P<0.01); the ratio of RANKL/ OPG in group Ⅳ was higher than that in group Ⅵ (P<0.01); the ratio of RANKL/OPG in group Ⅴ was lower than TGF-β signaling transduction plays an important role in the effect of baicalin on the RANKL/OPG ratio in HPDL cells.

  17. SOCIAL DEFEAT STRESS ACTIVATES MEDIAL AMYGDALA CELLS THAT EXPRESS TYPE 2 CORTICOTROPIN-RELEASING FACTOR RECEPTOR mRNA

    OpenAIRE

    FEKETE, É. M.; Y. Zhao; Li, C.; SABINO, V.; Vale, W.W.; ZORRILLA, E. P.

    2009-01-01

    Defeat is a social stressor involving subordination by a threatening conspecific. Type 2 corticotropin-releasing factor receptors (CRF2) are abundant in brain regions implicated in defeat responses and are putative stress-related molecules. The present study sought to determine whether neuroactivation and CRF2 expression co-occurred at brain region or cellular levels following acute defeat. Male “intruder” Wistar rats were placed into the cage of an aggressive “resident” Long-Evans rat (n=6)....

  18. NADPH Oxidase NOX1 Controls Autocrine Growth of Liver Tumor Cells through Up-regulation of the Epidermal Growth Factor Receptor Pathway*

    OpenAIRE

    Sancho, Patricia; Fabregat, Isabel

    2010-01-01

    FaO rat hepatoma cells proliferate in the absence of serum through a mechanism that requires activation of the epidermal growth factor receptor (EGFR) pathway. The aim of this work was to analyze the molecular mechanisms that control EGFR activation in these and other liver tumor cells. Reactive oxygen species production is observed a short time after serum withdrawal in FaO cells, coincident with up-regulation of the NADPH oxidase NOX1. NOX1-targeted knockdown, the use of antioxidants, or ph...

  19. Data on alteration of hormone and growth factor receptor profiles over progressive passages of breast cancer cell lines representing different clinical subtypes.

    Science.gov (United States)

    Nair, Madhumathy G; Desai, Krisha; Prabhu, Jyothi S; Hari, P S; Remacle, Jose; Sridhar, T S

    2016-09-01

    Human breast cancers are a highly heterogeneous group of tumours consisting of several molecular subtypes with a variable profile of hormone, growth factor receptors and cytokeratins [1]. Here, the data shows immunofluorescence profiling of four different cell lines belonging to distinct clinical subtypes of breast cancer. Post revival, the cell lines were passaged in culture and immunophenotyping was done for ER, HER-2, AR and EGFR. Data for the markers from early passage (5th) through passages as late as 25 for the different cell lines is presented. PMID:27508248

  20. The endocytosis of epidermal growth factor in A431 cells: A pH of microenvironment and the dynamics of receptor complex dissociation

    International Nuclear Information System (INIS)

    The endocytosis and intracellular fate of epidermal growth factor (EGF) were studied in A431 cells. After 15-20 min of internalization at 37 degree C, rhodomaine-labeled [125-I] EGF (EGR-Rh) accumulated into large juxtanuclear compartment consisting of closely related vesicles. This structure was shown to be localized in the para-Golgi region. Fluorescein-labeled transferrin (Tr-FITC) was observed in the same region when added to the cell simultaneously with EGF-Rh. Using microscopy spectrofluorometer, the authors determined that the Tr-FITC-containing para-Golgi structures have a pH of 6.1±0.3 while lysosomes containing dextran-fluorescein have a pH of 5.0±0.2. To study the dynamics of EGF-receptor dissociation during endocytosis a mild detergent treatment of living cells was used for extraction of an intracellular receptor-unbound EGF. These results suggest that EGF remains associated with receptors during endocytosis in A431 cells until it is transferred to lysosomes where the pH of the EGF microenvironment is dropped to 5. A prolonged presence of EGF-receptor complexes in the para-Golgi region might be of importance in mitotic signaling

  1. Rapid Detection of the Epidermal Growth Factor Receptor Mutation in Non-Small-Cell Lung Cancer for Analysis of Acquired Resistance Using Molecular Beacons

    OpenAIRE

    Oh, Young-Hee; Kim, Youngwook; Kim, Young-Pil; Seo, Soo-Won; Mitsudomi, Tetsuya; Ahn, Myung-Ju; Park, Keunchil; Kim, Hak-Sung

    2010-01-01

    A secondary mutation (T790M) in epidermal growth factor receptor (EGFR) is a hallmark of acquired resistance to EGFR inhibitors used to treat non-small-cell lung cancer (NSCLC). Therefore, identifying the T790M mutation is crucial to guide treatment decisions. Given that DNA sequencing methods are time-consuming and insensitive, we developed and investigated the feasibility of using molecular beacons for the detection of the T790M mutation in EGFR. A molecular beacon complementary to the regi...

  2. Fermented milk containing Lactobacillus GG alleviated DSS-induced colitis in mice and activated epidermal growth factor receptor and Akt signaling in intestinal epithelial cells

    Directory of Open Access Journals (Sweden)

    Kazutoyo Yoda

    2012-06-01

    Full Text Available Lactobacillus rhamnosus GG was assessed for its ability to alleviate DSS-induced colitis in mice and activate epidermal growth factor receptor and Akt signaling in intestinal epithelial cells. In this study mice were treated with DSS to induce colitis and they were given Lactobacillus GG fermented milk to assess the effect of probiotic on colitis. Lactobacillus GG fermented milk significantly reduced the colitis associated changes suggesting a protective effect against DSS induced colitis.

  3. Fermented milk containing Lactobacillus GG alleviated DSS-induced colitis in mice and activated epidermal growth factor receptor and Akt signaling in intestinal epithelial cells

    OpenAIRE

    Yoda, Kazutoyo; He, Fang; Miyazawa, Kenji; Hiramatsu, Masaru

    2012-01-01

    Lactobacillus rhamnosus GG was assessed for its ability to alleviate DSS-induced colitis in mice and activate epidermal growth factor receptor and Akt signaling in intestinal epithelial cells. In this study mice were treated with DSS to induce colitis and they were given Lactobacillus GG fermented milk to assess the effect of probiotic on colitis. Lactobacillus GG fermented milk significantly reduced the colitis associated changes suggesting a protective effect against DSS induced colitis.Key...

  4. Detection of epidermal growth factor receptor mutations in formalin fixed paraffin embedded biopsies in Malaysian non-small cell lung cancer patients

    OpenAIRE

    Shi Yeen, Tiffany Ng; Pathmanathan, Rajadurai; Shiran, Mohd Sidik; Ahmad Zaid, Fattah Azman; Cheah, Yoke Kqueen

    2013-01-01

    Background Somatic mutations of the epidermal growth factor receptor (EGFR) are reportedly associated with various responses in non-small cell lung cancer (NSCLC) patients receiving the anti-EGFR agents. Detection of the mutation therefore plays an important role in therapeutic decision making. The aim of this study was to detect EGFR mutations in formalin fixed paraffin embedded (FFPE) samples using both Scorpion ARMS and high resolution melt (HRM) assay, and to compare the sensitivity of th...

  5. Toll-like Receptor 3 Regulates Angiogenesis and Apoptosis in Prostate Cancer Cell Lines through Hypoxia-Inducible Factor

    OpenAIRE

    Alessio Paone; Roberta Galli; Chiara Gabellini; Dmitriy Lukashev; Donatella Starace; Agnes Gorlach; Paola De Cesaris; Elio Ziparo; Donatella Del Bufalo; Sitkovsky, Michail V.; Antonio Filippini; Anna Riccioli

    2010-01-01

    Toll-like receptors (TLRs) recognize microbial/viral-derived components that trigger innate immune response and conflicting data implicate TLR agonists in cancer, either as protumor or antitumor agents. We previously demonstrated that TLR3 activation mediated by its agonist poly(I:C) induces antitumor signaling, leading to apoptosis of prostate cancer cells LNCaP and PC3 with much more efficiency in the former than in the second more aggressive line. The transcription factor hypoxia-inducible...

  6. Toll-like Receptor 3 Regulates Angiogenesis and Apoptosis in Prostate Cancer Cell Lines through Hypoxia-Inducible Factor 1α1

    OpenAIRE

    Paone, Alessio; Galli, Roberta; Gabellini, Chiara; Lukashev, Dmitriy; Starace, Donatella; Gorlach, Agnes; Cesaris, Paola; Ziparo, Elio; Del Bufalo, Donatella; Sitkovsky, Michail V.; Filippini, Antonio; Riccioli, Anna

    2010-01-01

    Toll-like receptors (TLRs) recognize microbial/viral-derived components that trigger innate immune response and conflicting data implicate TLR agonists in cancer, either as protumor or antitumor agents. We previously demonstrated that TLR3 activation mediated by its agonist poly(I:C) induces antitumor signaling, leading to apoptosis of prostate cancer cells LNCaP and PC3 with much more efficiency in the former than in the second more aggressive line. The transcription factor hypoxia-inducible...

  7. Nomogram Predicting Clinical Outcomes in Non-small Cell Lung Cancer Patients Treated with Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitors

    OpenAIRE

    Keam, Bhumsuk; Kim, Dong-Wan; Park, Jin Hyun; Lee, Jeong-Ok; Kim, Tae Min; Lee, Se-Hoon; Chung, Doo Hyun; Heo, Dae Seog

    2014-01-01

    Purpose The aim of this study was to develop a pragmatic nomogram for prediction of progressionfree survival (PFS) for the epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) in EGFR mutant non-small cell lung cancer (NSCLC). Materials and Methods A total of 306 recurred or metastatic NSCLC patients with EGFR mutation, who received EGFR TKIs, were enrolled in this study. We developed the nomogram, using a Cox proportional hazard regression model for PFS. Results The median...

  8. Epidermal growth factor receptor expression affects the efficacy of the combined application of saponin and a targeted toxin on human cervical carcinoma cells.

    Science.gov (United States)

    Bachran, Diana; Schneider, Stefanie; Bachran, Christopher; Urban, Romy; Weng, Alexander; Melzig, Matthias F; Hoffmann, Corinna; Kaufmann, Andreas M; Fuchs, Hendrik

    2010-09-01

    Cervical cancer is the second most common cancer in women worldwide. Targeting the epidermal growth factor receptor (EGFR) is a very promising approach since it is overexpressed in about 90% of cervical tumors. Here, we quantified the toxic effect of SE, a targeted toxin consisting of epidermal growth factor (EGF) as targeting moiety and the plant toxin saporin-3, on 3 common human cervical carcinoma cell lines (HeLa, CaSki and SiHa) and recently established lines (PHCC1 and PHCC2) from 2 different individuals. A human melanocytic and a mouse cell line served as negative control. Additionally, we combined SE with saponinum album, a saponin composite from Gypsophila paniculata, which exhibited synergistic properties in previous studies. The cell lines, except for SiHa cells, revealed high sensitivity to SE with 50% cell survival in the range of 5-24.5 nM. The combination with saponin resulted in a remarkable enhancement of cytotoxicity with enhancement factors ranging from 9,000-fold to 2,500,000-fold. The cytotoxicity of SE was clearly target receptor specific since free EGF blocks the effect and saporin-3 alone was considerably less toxic. For all cervical carcinoma cell lines, we evinced a clear correlation between EGFR expression and SE sensitivity. Our data indicate a potential use of targeted toxins for the treatment of cervical cancer. In particular, the combination with saponins is a promising approach since efficacy is drastically improved. PMID:20020492

  9. 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; Moses, H L; Spang-Thomsen, M; Skovgaard Poulsen, H

    cancer (SCLC). The purpose of this study was to examine the cause of absent RII expression in SCLC cell lines. Northern blot analysis showed that RII RNA expression was very weak in 16 of 21 cell lines. To investigate if the absence of RII transcript was due to mutations, we screened the poly-A tract for...... hypermethylation. Southern blot analysis of the RII promoter did not show altered methylation patterns. The restriction endonuclease pattern of the RII gene was altered in two SCLC cell lines when digested with Smal. However, treatment with 5-aza-2'-deoxycytidine did not induce expression of RII mRNA. Our results...

  10. Aromatic hydrocarbon receptor inhibits lysophosphatidic acid-induced vascular endothelial growth factor-A expression in PC-3 prostate cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Pei-Yi; Lin, Yueh-Chien; Lan, Shun-Yan [Institute of Zoology, National Taiwan University, Taipei, Taiwan (China); Huang, Yuan-Li [Department of Biotechnology, Asia University, Taichung, Taiwan (China); Lee, Hsinyu, E-mail: hsinyu@ntu.edu.tw [Institute of Zoology, National Taiwan University, Taipei, Taiwan (China); Department of Life Science, National Taiwan University, Taipei, Taiwan (China)

    2013-08-02

    Highlights: •LPA-induced VEGF-A expression was regulated by HIF-1α and ARNT. •PI3K mediated LPA-induced VEGF-A expression. •AHR signaling inhibited LPA-induced VEGF-A expression in PC-3 cells. -- Abstract: Lysophosphatidic acid (LPA) is a lipid growth factor with multiple biological functions and has been shown to stimulate cancer cell secretion of vascular endothelial growth factor-A (VEGF-A) and trigger angiogenesis. Hypoxia-inducible factor-1 (HIF-1), a heterodimer consisting of HIF-1α and HIF-1β (also known as aromatic hydrocarbon receptor nuclear translocator (ARNT)) subunits, is an important regulator of angiogenesis in prostate cancer (PC) through the enhancement of VEGF-A expression. In this study, we first confirmed the ability of LPA to induce VEGF-A expression in PC-3 cells and then validated that LPA-induced VEGF-A expression was regulated by HIF-1α and ARNT through phosphatidylinositol 3-kinase activation. Aromatic hydrocarbon receptor (AHR), a receptor for dioxin-like compounds, functions as a transcription factor through dimerization with ARNT and was found to inhibit prostate carcinogenesis and vanadate-induced VEGF-A production. Since ARNT is a common dimerization partner of AHR and HIF-1α, we hypothesized that AHR might suppress LPA-induced VEGF-A expression in PC-3 cells by competing with HIF-1α for ARNT. Here we demonstrated that overexpression and ligand activation of AHR inhibited HIF-1-mediated VEGF-A induction by LPA treatment of PC-3 cells. In conclusion, our results suggested that AHR activation may inhibit LPA-induced VEGF-A expression in PC-3 cells by attenuating HIF-1α signaling, and subsequently, suppressing angiogenesis and metastasis of PC. These results suggested that AHR presents a potential therapeutic target for the prevention of PC metastasis.

  11. Epidermal Growth Factor Receptor in Pancreatic Cancer

    International Nuclear Information System (INIS)

    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

  12. Factors associated with early progression of non-small-cell lung cancer treated by epidermal growth factor receptor tyrosine-kinase inhibitors

    International Nuclear Information System (INIS)

    Epidermal growth factor receptor tyrosine-kinase inhibitors (EGFR-TKI) are a therapeutic option as second-line therapy in non-small-cell lung carcinoma (NSCLC), regardless of the EGFR gene status. Identifying patients with early progression during EGFR-TKI treatment will help clinicians to choose the best regimen, TKI or chemotherapy. From a prospective database, all patients treated with gefitinib or erlotinib between 2001 and 2010 were retrospectively reviewed. Patients were classified into two groups according to their tumor response by RECIST after 45 days of treatment, progressive disease (PD) or controlled disease (CD). Two hundred and sixty-eight patients were treated with EGFR-TKI, among whom 239 were classified as PD (n = 75) and CD (n = 164). Median overall survival was 77 days (95% CI 61–109) for PD and 385 days (95% CI 267–481) for CD. Patients with PD were of younger age (P = 0.004) and more frequently current smokers (P = 0.001) had more frequently a performance status ≥2 (P = 0.012), a weight loss ≥10% (P = 0.025), a shorter time since diagnosis (P < 0.0001), a pathological classification as non-otherwise-specified NSCLC (P = 0.01), and the presence of abdominal metastases (P = 0.008). In multivariate analysis, abdominal metastases were the only factor associated with early progression (odds ratio (OR) 2.17, 95% CI [1.12–4.19]; P = 0.021). Wild-type EGFR versus mutated EGFR was associated with early progression. The presence of abdominal metastasis was independently associated with early progression in metastatic NSCLC receiving EGFR-TKI

  13. In vitro invasion of small-cell lung cancer cell lines correlates with expression of epidermal growth factor receptor

    DEFF Research Database (Denmark)

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

    1998-01-01

    Formation of metastasis is a multistep process involving attachment to the basement membrane, local proteolysis and migration into surrounding tissues, lymph or bloodstream. In the present study, we have analysed the correlation between in vitro invasion and presence of the epidermal growth factor...

  14. Expression and function of hematopoiesis-stimulating factor receptors on the GPI− and GPI+ hematopoietic stem cells of patients with paroxysmal nocturnal hemoglobinuria/aplastic anemia syndrome

    Science.gov (United States)

    FU, RONG; DING, SHAO-XUE; LIU, YI; LI, LI-JUAN; LIU, HUI; WANG, HONG-LEI; ZHANG, TIAN; SHAO, ZONG-HONG

    2016-01-01

    Paroxysmal nocturnal hemoglobinuria/aplastic anemia (PNH/AA) syndrome presents a markedly increased population of cells deficient in glycophosphatidylinositol (GPI− cells) and signs of bone marrow failure, which requires treatment with hematopoiesis-stimulating factors, such as granulocyte colony-stimulating factor (G-CSF) and stem cell factor (SCF). However, little is known about the effects of these stimulating factors on GPI− cells. In order to explore the effects of stimulating factors in PNH/AA, G-CSF receptor (CD114) and SCF receptor (CD117) expression levels on GPI+ and GPI− hematopoietic stem cells (HSCs) were measured by flow cytometry (FCM). The mean fluorescence intensity (MFI) values of signal transducer and activator of transcription 5 (STAT5) and phosphorylated (P)-STAT5 were measured in GPI+ and GPI− HSCs by FCM following stimulation with G-CSF or SCF in vitro. The expression levels of CD114 and CD117 on GPI− HSCs were significantly lower (P<0.01) than those on GPI+ HSCs in PNH/AA patients and normal controls. The MFI values of STAT5 in the GPI− and GPI+ HSCs of PNH/AA patients and normal controls were not significantly different. However, the MFI values of P-STAT5 in the GPI− HSCs of PNH/AA patients were significantly lower than those in the GPI+ HSCs of PNH/AA patients and normal controls prior to and following stimulation with G-CSF or SCF (P<0.01). The GPI− HSCs of PNH/AA patients responded poorly to stimulation by hematopoiesis-stimulating factors, which indicates that these factors can be used safely in patients with PNH/AA.

  15. Efficacy of anti-insulin like growth factor I receptor (IGF-IR) monoclonal antibody cixutumumab in mesothelioma is highly correlated with IGF-IR sites/cell

    OpenAIRE

    Kalra, Neetu; Zhang, Jingli; Yu, Yunkai; Ho, Mitchell; Merino, Maria; Cao, Liang; Hassan, Raffit

    2012-01-01

    Insulin growth factor-I receptor (IGF-IR) is expressed in mesothelioma and therefore an attractive target for therapy. The anti-tumor activity of cixutumumab, a humanized monoclonal antibody to IGF-IR, in mesothelioma and relationship to IGF-IR expression was investigated using eight early passage tumor cells obtained from patients, nine established cell lines and an in vivo human mesothelioma tumor xenograft model. Although IGF-IR expression at the mRNA and protein level was present in all m...

  16. Human Induced Pluripotent Stem Cell-Derived Cardiac Progenitor Cells in Phenotypic Screening: A Transforming Growth Factor-β Type 1 Receptor Kinase Inhibitor Induces Efficient Cardiac Differentiation.

    Science.gov (United States)

    Drowley, Lauren; Koonce, Chad; Peel, Samantha; Jonebring, Anna; Plowright, Alleyn T; Kattman, Steven J; Andersson, Henrik; Anson, Blake; Swanson, Bradley J; Wang, Qing-Dong; Brolen, Gabriella

    2016-02-01

    Several progenitor cell populations have been reported to exist in hearts that play a role in cardiac turnover and/or repair. Despite the presence of cardiac stem and progenitor cells within the myocardium, functional repair of the heart after injury is inadequate. Identification of the signaling pathways involved in the expansion and differentiation of cardiac progenitor cells (CPCs) will broaden insight into the fundamental mechanisms playing a role in cardiac homeostasis and disease and might provide strategies for in vivo regenerative therapies. To understand and exploit cardiac ontogeny for drug discovery efforts, we developed an in vitro human induced pluripotent stem cell-derived CPC model system using a highly enriched population of KDR(pos)/CKIT(neg)/NKX2.5(pos) CPCs. Using this model system, these CPCs were capable of generating highly enriched cultures of cardiomyocytes under directed differentiation conditions. In order to facilitate the identification of pathways and targets involved in proliferation and differentiation of resident CPCs, we developed phenotypic screening assays. Screening paradigms for therapeutic applications require a robust, scalable, and consistent methodology. In the present study, we have demonstrated the suitability of these cells for medium to high-throughput screens to assess both proliferation and multilineage differentiation. Using this CPC model system and a small directed compound set, we identified activin-like kinase 5 (transforming growth factor-β type 1 receptor kinase) inhibitors as novel and potent inducers of human CPC differentiation to cardiomyocytes. Significance: Cardiac disease is a leading cause of morbidity and mortality, with no treatment available that can result in functional repair. This study demonstrates how differentiation of induced pluripotent stem cells can be used to identify and isolate cell populations of interest that can translate to the adult human heart. Two separate examples of phenotypic

  17. Glucagon-like Peptide-1 Increases β-Cell Glucose Competence and Proliferation by Translational Induction of Insulin-like Growth Factor-1 Receptor Expression*

    OpenAIRE

    Cornu, Marion; Modi, Honey; Kawamori, Dan; Kulkarni, Rohit N.; Joffraud, Magali; Thorens, Bernard

    2010-01-01

    Glucagon-like peptide-1 (GLP-1) protects β-cells against apoptosis, increases their glucose competence, and induces their proliferation. We previously demonstrated that the anti-apoptotic effect was mediated by an increase in insulin-like growth factor-1 receptor (IGF-1R) expression and signaling, which was dependent on autocrine secretion of insulin-like growth factor 2 (IGF-2). Here, we further investigated how GLP-1 induces IGF-1R expression and whether the IGF-2/IGF-1R autocrine loop is a...

  18. Tyrosine kinase inhibitors for epidermal growth factor receptor gene mutation-positive non-small cell lung cancers: an update for recent advances in therapeutics.

    Science.gov (United States)

    Chung, Clement

    2016-06-01

    The presence of activating gene mutations in the epidermal growth factor receptor of non-small cell lung cancer patients is predictive (improved progression-free survival and improved response rate) when treated with small molecule tyrosine kinase inhibitors such as gefitinib, erlotinib and afatinib. The two most common mutations that account for greater than 85% of all EGFR gene mutations are in-frame deletions in exon 19 (LREA deletions) and substitution in exon 21 (L858R). Exon 18 mutations occur much less frequently at about 4% of all EGFR gene mutations. Together, exon 19 deletion and exon 21 L858R gene substitution are present in about 10% of Caucasian patients and 20-40% of Asian patients with non-small cell lung cancer. T790M gene mutation at exon 20 is associated with acquired resistance to epidermal growth factor receptor tyrosine kinase inhibitors. Early studies showed that activating EGFR gene mutations are most common in patients with adenocarcinoma histology, women, never smokers and those of Asian ethnicity. A recent multi-center phase III trial suggested that frontline epidermal growth factor receptor tyrosine kinase inhibitor therapy with afatinib is associated with improved progression-free survival compared to chemotherapy regardless of race. Moreover, guidelines now suggest EGFR gene mutation testing should be conducted in all patients with lung adenocarcinoma or mixed lung cancers with an adenocarcinoma component, regardless of characteristics such as smoking status, gender or race. The success of targeted therapies in non-small cell lung cancer patients has changed the treatment paradigm in metastatic non-small cell lung cancer. However, despite a durable response of greater than a year, resistance to epidermal growth factor receptor tyrosine kinase inhibitors inevitably occurs. This mini-review describes the clinically relevant EGFR gene mutations and the efficacy/toxicity of small molecule epidermal growth factor receptor tyrosine kinase

  19. Role of nuclear factor of activated T-cells 5 in regulating hypertonic-mediated secretin receptor expression in kidney collecting duct cells.

    Science.gov (United States)

    Chua, Oscar W H; Wong, Kenneth K L; Ko, Ben C; Chung, Sookja K; Chow, Billy K C; Lee, Leo T O

    2016-07-01

    A growing body of evidence suggests that secretin (SCT) is an important element in the osmoregulatory pathway. It is interesting to note that both SCT and its receptor (SCTR) gene are activated upon hyperosmolality in the kidney. However, the precise molecular mechanisms underlying the induction of the SCTR gene expression in response to changes in osmolality have yet to be clarified. Detailed DNA sequence analysis of the promoter regions of the SCTR gene reveals the presence of multiple osmotic response elements (ORE). The ORE is the binding site of a key osmosensitive transactivator, namely, the nuclear factor of activated T-cells 5 (NFAT5). SCTR and NFAT5 are co-expressed in the kidney cortex and medulla collecting duct cells. We therefore hypothesize that NFAT5 is responsible for modulating SCTR expression in hypertonic environments. In this study, we found hypertonicity stimulates the promoter activities and endogenous gene expression of SCTR in mouse kidney cortex collecting duct cells (M1) and inner medulla collecting duct cells (mIMCD3). The overexpression and silencing of NFAT5 further confirmed it to be responsible for the up-regulation of the SCTR gene under hypertonic conditions. A significant increase in the interaction between NFAT5 and the SCTR promoter was also observed following chromatin immunoprecipitation assay. In vivo, osmotic stress up-regulates the SCTR gene in the kidney cortex and medulla of wild-type mice, but does not do so in NFAT5(+/-) animals. Hence, this study provides comprehensive information on how NFAT5 regulates SCTR expression in different osmotic environments. PMID:27080132

  20. Modulation of the tyrosine kinase receptor Ret/glial cell-derived neurotrophic factor (GDNF) signaling: a new player in reproduction induced anterior pituitary plasticity?

    Science.gov (United States)

    Guillou, Anne; Romanò, Nicola; Bonnefont, Xavier; Le Tissier, Paul; Mollard, Patrice; Martin, Agnès O

    2011-02-01

    During gestation, parturition, and lactation, the endocrine axis of the dam must continually adapt to ensure the continual and healthy development of offspring. The anterior pituitary gland, which serves as the endocrine interface between the brain and periphery, undergoes adaptations that contribute to regulation of the reproductive axis. Growth factors and their receptors are potential candidates for intrapituitary and paracrine factors to participate in the functional and anatomical plasticity of the gland. We examined the involvement of the growth factor glial cell-derived neurotrophic factor (GDNF) and its receptor tyrosine kinase rearranged during transfection (Ret) in the physiological functional and anatomical plasticity of the anterior pituitary gland. We found that variations in both expression and subcellular localization of Ret during gestation and lactation are temporally correlated with changes in pituitary gland function. We showed that Ret/GDNF signaling could endorse two different functional roles depending on the physiological status. At the end of lactation and after weaning, Ret was colocalized with markers of apoptosis. We found that Ret could therefore act as a physiological dependence receptor capable of inducing apoptosis in the absence of GDNF. In addition, we identified the follicullostellate cell as a probable source for intrapituitary GDNF and proposed GDNF as a potential physiological modulator of endocrine cell function. During all stages studied, we showed that acute application of GDNF to pituitary slices was able to modulate both positively and negatively intracellular calcium activity. Altogether our results implicate Ret/GDNF as a potent pleiotropic factor able to influence pituitary physiology during a period of high plasticity. PMID:21239429

  1. The siRNA cocktail targeting interleukin 10 receptor and transforming growth factorreceptor on dendritic cells potentiates tumour antigen-specific CD8(+) T cell immunity.

    Science.gov (United States)

    Ahn, Y-H; Hong, S-O; Kim, J H; Noh, K H; Song, K-H; Lee, Y-H; Jeon, J-H; Kim, D-W; Seo, J H; Kim, T W

    2015-07-01

    Dendritic cells (DCs) are promising therapeutic agents in the field of cancer immunotherapy due to their intrinsic immune-priming capacity. The potency of DCs, however, is readily attenuated immediately after their administration in patients as tumours and various immune cells, including DCs, produce various immunosuppressive factors such as interleukin (IL)-10 and transforming growth factor (TGF)-β that hamper the function of DCs. In this study, we used small interfering RNA (siRNA) to silence the expression of endogenous molecules in DCs, which can sense immunosuppressive factors. Among the siRNAs targeting various immunosuppressive molecules, we observed that DCs transfected with siRNA targeting IL-10 receptor alpha (siIL-10RA) initiated the strongest antigen-specific CD8(+) T cell immune responses. The potency of siIL-10RA was enhanced further by combining it with siRNA targeting TGF-β receptor (siTGF-βR), which was the next best option during the screening of this study, or the previously selected immunoadjuvant siRNA targeting phosphatase and tensin homologue deleted on chromosome 10 (PTEN) or Bcl-2-like protein 11 (BIM). In the midst of sorting out the siRNA cocktails, the cocktail of siIL-10RA and siTGF-βR generated the strongest antigen-specific CD8(+) T cell immunity. Concordantly, the knock-down of both IL-10RA and TGF-βR in DCs induced the strongest anti-tumour effects in the TC-1 P0 tumour model, a cervical cancer model expressing the human papillomavirus (HPV)-16 E7 antigen, and even in the immune-resistant TC-1 (P3) tumour model that secretes more IL-10 and TGF-β than the parental tumour cells (TC-1 P0). These results provide the groundwork for future clinical development of the siRNA cocktail-mediated strategy by co-targeting immunosuppressive molecules to enhance the potency of DC-based vaccines. PMID:25753156

  2. Tissue kallikrein induces SH-SY5Y cell proliferation via epidermal growth factor receptor and extracellular signal-regulated kinase1/2 pathway

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Zhengyu [Department of Neurology, Huashan Hospital, State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai 200040 (China); Department of Neurology, Yueyang Hospital of Integrated Traditional Chinese and Western Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai 200437 (China); Yang, Qi; Cui, Mei; Liu, Yanping [Department of Neurology, Huashan Hospital, State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai 200040 (China); Wang, Tao; Zhao, Hong [Department of Neurology, Yueyang Hospital of Integrated Traditional Chinese and Western Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai 200437 (China); Dong, Qiang, E-mail: qiang_dong163@163.com [Department of Neurology, Huashan Hospital, State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai 200040 (China)

    2014-03-28

    Highlights: • TK promotes EGFR phosphorylation in SH-SY5Y cells. • TK activates ERK1/2 and p38 phosphorylation in SH-SY5Y cells. • TK mediates SH-SY5Y cell proliferation via EGFR and ERK1/2 pathway. - Abstract: Tissue kallikrein (TK) is well known to take most of its biological functions through bradykinin receptors. In the present study, we found a novel signaling pathway mediated by TK through epidermal growth factor receptor (EGFR) in human SH-SY5Y cells. We discovered that TK facilitated the activation of EGFR, extracellular signal-regulated kinase (ERK) 1/2 and p38 cascade. Interestingly, not p38 but ERK1/2 phosphorylation was severely compromised in cells depleted of EGFR. Nevertheless, impairment of signaling of ERK1/2 seemed not to be restricted to EGFR phosphorylation. We also observed that TK stimulation could induce SH-SY5Y cell proliferation, which was reduced by EGFR down-regulation or ERK1/2 inhibitor. Overall, our findings provided convincing evidence that TK could mediate cell proliferation via EGFR and ERK1/2 pathway in vitro.

  3. Tissue kallikrein induces SH-SY5Y cell proliferation via epidermal growth factor receptor and extracellular signal-regulated kinase1/2 pathway

    International Nuclear Information System (INIS)

    Highlights: • TK promotes EGFR phosphorylation in SH-SY5Y cells. • TK activates ERK1/2 and p38 phosphorylation in SH-SY5Y cells. • TK mediates SH-SY5Y cell proliferation via EGFR and ERK1/2 pathway. - Abstract: Tissue kallikrein (TK) is well known to take most of its biological functions through bradykinin receptors. In the present study, we found a novel signaling pathway mediated by TK through epidermal growth factor receptor (EGFR) in human SH-SY5Y cells. We discovered that TK facilitated the activation of EGFR, extracellular signal-regulated kinase (ERK) 1/2 and p38 cascade. Interestingly, not p38 but ERK1/2 phosphorylation was severely compromised in cells depleted of EGFR. Nevertheless, impairment of signaling of ERK1/2 seemed not to be restricted to EGFR phosphorylation. We also observed that TK stimulation could induce SH-SY5Y cell proliferation, which was reduced by EGFR down-regulation or ERK1/2 inhibitor. Overall, our findings provided convincing evidence that TK could mediate cell proliferation via EGFR and ERK1/2 pathway in vitro

  4. Bacterial wall products induce downregulation of vascular endothelial growth factor receptors on endothelial cells via a CD14-dependent mechanism: implications for surgical wound healing.

    LENUS (Irish Health Repository)

    Power, C

    2012-02-03

    INTRODUCTION: Vascular endothelial growth factor (VEGF) is a potent mitogenic cytokine which has been identified as the principal polypeptide growth factor influencing endothelial cell (EC) migration and proliferation. Ordered progression of these two processes is an absolute prerequisite for initiating and maintaining the proliferative phase of wound healing. The response of ECs to circulating VEGF is determined by, and directly proportional to, the functional expression of VEGF receptors (KDR\\/Flt-1) on the EC surface membrane. Systemic sepsis and wound contamination due to bacterial infection are associated with significant retardation of the proliferative phase of wound repair. The effects of the Gram-negative bacterial wall components lipopolysaccharide (LPS) and bacterial lipoprotein (BLP) on VEGF receptor function and expression are unknown and may represent an important biological mechanism predisposing to delayed wound healing in the presence of localized or systemic sepsis. MATERIALS AND METHODS: We designed a series of in vitro experiments investigating this phenomenon and its potential implications for infective wound repair. VEGF receptor density on ECs in the presence of LPS and BLP was assessed using flow cytometry. These parameters were assessed in hypoxic conditions as well as in normoxia. The contribution of CD14 was evaluated using recombinant human (rh) CD14. EC proliferation in response to VEGF was quantified in the presence and absence of LPS and BLP. RESULTS: Flow cytometric analysis revealed that LPS and BLP have profoundly repressive effects on VEGF receptor density in normoxic and, more pertinently, hypoxic conditions. The observed downregulation of constitutive and inducible VEGF receptor expression on ECs was not due to any directly cytotoxic effect of LPS and BLP on ECs, as measured by cell viability and apoptosis assays. We identified a pivotal role for soluble\\/serum CD14, a highly specific bacterial wall product receptor, in

  5. Pancreatic adenocarcinoma upregulated factor (PAUF) confers resistance to pancreatic cancer cells against oncolytic parvovirus H-1 infection through IFNA receptor-mediated signaling

    International Nuclear Information System (INIS)

    Pancreatic adenocarcinoma upregulated factor (PAUF), a novel oncogene, plays a crucial role in the development of pancreatic cancer, including its metastasis and proliferation. Therefore, PAUF-expressing pancreatic cancer cells could be important targets for oncolytic virus-mediated treatment. Panc-1 cells expressing PAUF (Panc-PAUF) showed relative resistance to parvovirus H-1 infection compared with Panc-1 cells expressing an empty vector (Panc-Vec). Of interest, expression of type I IFN-α receptor (IFNAR) was higher in Panc-PAUF cells than in Panc-Vec cells. Increased expression of IFNAR in turn increased the activation of Stat1 and Tyk2 in Panc-PAUF cells compared with that in Panc-Vec cells. Suppression of Tyk2 and Stat1, which are important downstream molecules for IFN-α signaling, sensitized pancreatic cancer cells to parvovirus H-1-mediated apoptosis. Further, constitutive suppression of PAUF sensitized Bxpc3 pancreatic cancer cells to parvovirus H-1 infection. Taken together, these results suggested that PAUF conferred resistance to pancreatic cancer cells against oncolytic parvovirus H-1 infection through IFNAR-mediated signaling. - Highlights: • PAUF confers resistance against oncolytic parvovirus H-1 infection. • PAUF enhances the expression of IFNAR in Panc-1 cells. • Increased activation of Tyk2 or Stat1 by PAUF provides resistance to parvovirus H-1-mediated apoptosis. • Constitutive inhibition of PAUF enhances parvovirus H-1-mediated oncolysis of Bxpc3 pancreatic cancer cells

  6. Pancreatic adenocarcinoma upregulated factor (PAUF) confers resistance to pancreatic cancer cells against oncolytic parvovirus H-1 infection through IFNA receptor-mediated signaling

    Energy Technology Data Exchange (ETDEWEB)

    Kaowinn, Sirichat; Cho, Il-Rae; Moon, Jeong; Jun, Seung Won; Kim, Chang Seok [BK21+, Department of Cogno-Mechatronics Engineering, Pusan National University, Busan 609-736 (Korea, Republic of); Kang, Ho Young [Department of Microbiology, Pusan National University, Busan 609-736 (Korea, Republic of); Kim, Manbok [Department of Medical Science, Dankook University College of Medicine, Cheonan 330-714 (Korea, Republic of); Koh, Sang Seok [Department of Biological Sciences, Dong-A University, Busan 604-714 (Korea, Republic of); Chung, Young-Hwa, E-mail: younghc@pusan.ac.kr [BK21+, Department of Cogno-Mechatronics Engineering, Pusan National University, Busan 609-736 (Korea, Republic of)

    2015-04-03

    Pancreatic adenocarcinoma upregulated factor (PAUF), a novel oncogene, plays a crucial role in the development of pancreatic cancer, including its metastasis and proliferation. Therefore, PAUF-expressing pancreatic cancer cells could be important targets for oncolytic virus-mediated treatment. Panc-1 cells expressing PAUF (Panc-PAUF) showed relative resistance to parvovirus H-1 infection compared with Panc-1 cells expressing an empty vector (Panc-Vec). Of interest, expression of type I IFN-α receptor (IFNAR) was higher in Panc-PAUF cells than in Panc-Vec cells. Increased expression of IFNAR in turn increased the activation of Stat1 and Tyk2 in Panc-PAUF cells compared with that in Panc-Vec cells. Suppression of Tyk2 and Stat1, which are important downstream molecules for IFN-α signaling, sensitized pancreatic cancer cells to parvovirus H-1-mediated apoptosis. Further, constitutive suppression of PAUF sensitized Bxpc3 pancreatic cancer cells to parvovirus H-1 infection. Taken together, these results suggested that PAUF conferred resistance to pancreatic cancer cells against oncolytic parvovirus H-1 infection through IFNAR-mediated signaling. - Highlights: • PAUF confers resistance against oncolytic parvovirus H-1 infection. • PAUF enhances the expression of IFNAR in Panc-1 cells. • Increased activation of Tyk2 or Stat1 by PAUF provides resistance to parvovirus H-1-mediated apoptosis. • Constitutive inhibition of PAUF enhances parvovirus H-1-mediated oncolysis of Bxpc3 pancreatic cancer cells.

  7. Hyaluronan suppresses prostate tumor cell proliferation through diminished expression of N-cadherin and aberrant growth factor receptor signaling

    Energy Technology Data Exchange (ETDEWEB)

    Bharadwaj, Alamelu G.; Goodrich, Nathaniel P.; McAtee, Caitlin O.; Haferbier, Katie [Department of Biochemistry, University of Nebraska, Lincoln, NE 68588 (United States); Oakley, Gregory G.; Wahl, James K. [Department of Oral Biology, University of Nebraska College of Dentistry, Lincoln, NE 68588 (United States); Simpson, Melanie A., E-mail: msimpson2@unl.edu [Department of Biochemistry, University of Nebraska, Lincoln, NE 68588 (United States); Eppley Cancer Center, University of Nebraska Medical Center, Omaha, NE 68198 (United States)

    2011-05-01

    Hyaluronan (HA) production has been functionally implicated in prostate tumorigenesis and metastasis. We previously used prostate tumor cells overexpressing the HA synthesizing enzyme HAS3 or the clinically relevant hyaluronidase Hyal1 to show that excess HA production suppresses tumor growth, while HA turnover accelerates spontaneous metastasis from the prostate. Here, we examined pathways responsible for effects of HAS3 and Hyal1 on tumor cell phenotype. Detailed characterization of cell cycle progression revealed that expression of Hyal1 accelerated cell cycle re-entry following synchronization, whereas HAS3 alone delayed entry. Hyal1 expressing cells exhibited a significant reduction in their ability to sustain ERK phosphorylation upon stimulation by growth factors, and in their expression of the cyclin-dependent kinase inhibitor p21. In contrast, HAS3 expressing cells showed prolonged ERK phosphorylation and increased expression of both p21 and p27, in asynchronous and synchronized cultures. Changes in cell cycle regulatory proteins were accompanied by HA-induced suppression of N-cadherin, while E-cadherin expression and {beta}-catenin expression and distribution remained unchanged. Our results are consistent with a model in which excess HA synthesis suppresses cell proliferation by promoting homotypic E-cadherin mediated cell-cell adhesion, consequently signaling to elevate cell cycle inhibitor expression and suppress G1- to S-phase transition.

  8. Hyaluronan suppresses prostate tumor cell proliferation through diminished expression of N-cadherin and aberrant growth factor receptor signaling

    International Nuclear Information System (INIS)

    Hyaluronan (HA) production has been functionally implicated in prostate tumorigenesis and metastasis. We previously used prostate tumor cells overexpressing the HA synthesizing enzyme HAS3 or the clinically relevant hyaluronidase Hyal1 to show that excess HA production suppresses tumor growth, while HA turnover accelerates spontaneous metastasis from the prostate. Here, we examined pathways responsible for effects of HAS3 and Hyal1 on tumor cell phenotype. Detailed characterization of cell cycle progression revealed that expression of Hyal1 accelerated cell cycle re-entry following synchronization, whereas HAS3 alone delayed entry. Hyal1 expressing cells exhibited a significant reduction in their ability to sustain ERK phosphorylation upon stimulation by growth factors, and in their expression of the cyclin-dependent kinase inhibitor p21. In contrast, HAS3 expressing cells showed prolonged ERK phosphorylation and increased expression of both p21 and p27, in asynchronous and synchronized cultures. Changes in cell cycle regulatory proteins were accompanied by HA-induced suppression of N-cadherin, while E-cadherin expression and β-catenin expression and distribution remained unchanged. Our results are consistent with a model in which excess HA synthesis suppresses cell proliferation by promoting homotypic E-cadherin mediated cell-cell adhesion, consequently signaling to elevate cell cycle inhibitor expression and suppress G1- to S-phase transition.

  9. Dexamethasone effects on creatine kinase activity and insulin-like growth factor receptors in cultured muscle cells

    Science.gov (United States)

    Whitson, Peggy A.; Stuart, Charles A.; Huls, M. H.; Sams, Clarence F.; Cintron, Nitza M.

    1989-01-01

    The effect of dexamethasone on the activity of creatine kinase (CK) and the insulin-like growth factor I (IGF-I) binding were investigated using skeletal- and cardiac-muscle-derived cultured cell lines (mouse, C2C12; rat, L6 and H9c2). It was found that, in skeletal muscle cells, dexamethasone treatment during differentiation of skeletal-muscle cells caused dose-dependent increases in CK activity and increases in the degree of myotube formation, whereas cardiac cells (H9c2) exhibited very low CK activity during culture or dexamethasone treatment. Results for IGF-I binding were similar in all three cell lines. The IGF-I binding to dexamethasone-treated cells (50 nM for 24 hr on the day prior to confluence) resulted in an increased number of available binding sites, with no effect on the binding affinities.

  10. EGCG inhibits activation of the insulin-like growth factor-1 receptor in human colon cancer cells

    International Nuclear Information System (INIS)

    The IGF/IGF-1R system, which includes the IGF, IGF-1R, and IGFBPs proteins, plays an important role in the development and growth of colorectal cancer. We previously reported that in the HT29 human colon cancer cell line EGCG, the major biologically active component of green tea, inhibits activation of the RTKs EGFR, HER2, and HER3, and that this is associated with inhibition of multiple downstream signaling pathways. Since IGF-1R is also a RTK, in this study we examined the effects of EGCG on the activity of IGF/IGF-1R system in human colon cancer cells. We found that the colon cancer cell lines Caco2, HT29, SW837, and SW480 express high levels of the IGF-1R receptor, and that both SW837 and SW480 cells display constitutive activation of this receptor. Treatment of SW837 cells with 20 μg/ml of EGCG (the IC50 concentration for growth inhibition) caused within 6 h a decrease in the phosphorylated (i.e., activated) form of the IGF-1R protein. At 12 h, there was a decrease in the levels of both IGF-1 protein and mRNA and within 3-6 h there was an increase in the levels of both IGFBP-3 protein and mRNA. The increased expression of the latter protein was sustained for at least 48 h. When SW837 cells were treated with EGCG for a longer time, i.e., 96 h, a very low concentration (1.0 μg/ml) of EGCG also caused inhibition of activation of IGF-1R, a decrease in the IGF-1 protein, and an increase in the IGFBP-3 protein. EGCG also caused a decrease in the levels of mRNAs that encode MMPs-7 and -9, proteins that proteolyze IGFBP-3. In addition, treatment with EGCG caused a transient increase in the expression of TGF-β2, an inducer of IGFBP-3 expression. These findings expand the roles of EGCG as an inhibitor of critical RTKs involved in cell proliferation, providing further evidence that EGCG and related compounds may be useful in the chemoprevention or treatment of colorectal cancer

  11. Antacid Use and De Novo Brain Metastases in Patients with Epidermal Growth Factor Receptor-Mutant Non-Small Cell Lung Cancer Who Were Treated Using First-Line First-Generation Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitors.

    Directory of Open Access Journals (Sweden)

    Yu-Mu Chen

    Full Text Available Antacid treatments decrease the serum concentrations of first-generation epidermal growth factor receptor (EGFR-tyrosine kinase inhibitors (TKIs, although it is unknown whether antacids affect clinical outcomes. As cerebrospinal fluid concentrations of TKIs are much lower than serum concentrations, we hypothesized that this drug-drug interaction might affect the prognosis of patients with de novo brain metastases.This retrospective study evaluated 269 patients with EGFR-mutant non-small cell lung cancer (NSCLC who had been diagnosed between December 2010 and December 2013, and had been treated using first-line first-generation EGFR-TKIs. Among these patients, we identified patients who concurrently used H2 receptor antagonists (H2RAs and proton pump inhibitors (PPIs as antacids. Patients who exhibited >30% overlap between the use of TKIs and antacids were considered antacid users.Fifty-seven patients (57/269, 21.2% were antacid users, and antacid use did not significantly affect progression-free survival (PFS; no antacids: 11.2 months, H2RAs: 9.4 months, PPIs: 6.7 months; p = 0.234. However, antacid use significantly reduced overall survival (OS; no antacids: 25.0 months, H2RAs: 15.5 months, PPIs: 11.3 months; p = 0.002. Antacid use did not affect PFS for various metastasis sites, although antacid users with de novo brain metastases exhibited significantly shorter OS, compared to non-users (11.8 vs. 16.3 months, respectively; p = 0.041. Antacid use did not significantly affect OS in patients with bone, liver, or pleural metastases.Antacid use reduced OS among patients with EGFR-mutant NSCLC who were treated using first-line first-generation EGFR-TKIs, and especially among patients with de novo brain metastases.

  12. Dopamine receptor regulating factor, DRRF: A zinc finger transcription factor

    OpenAIRE

    Hwang, Cheol Kyu; D'Souza, Ursula M.; Eisch, Amelia J.; Yajima, Shunsuke; Lammers, Claas-Hinrich; Yang, Young; Lee, Sang-Hyeon; Kim, Yong-Man; Nestler, Eric J.; Mouradian, M. Maral

    2001-01-01

    Dopamine receptor genes are under complex transcription control, determining their unique regional distribution in the brain. We describe here a zinc finger type transcription factor, designated dopamine receptor regulating factor (DRRF), which binds to GC and GT boxes in the D1A and D2 dopamine receptor promoters and effectively displaces Sp1 and Sp3 from these sequences. Consequently, DRRF can modulate the activity of these dopamine receptor promoters. Highest DRRF mRNA levels are found in ...

  13. MAST CELLS, MAST/STEM CELL GROWTH FACTOR RECEPTOR (C-KIT/CD117 AND IGE MAY BE INTEGRAL TO THE PATHOGENESIS OF ENDEMIC PEMPHIGUS FOLIACEUS

    Directory of Open Access Journals (Sweden)

    Ana Maria Roselino

    2013-11-01

    Full Text Available Introduction: Pemphigus foliaceus (PF is endemic in some South American countries, especially in Colombia and Brazil; in Brazil, it is also known as fogo selvagem (FS. We aimed to study the presence of mast cells and the expression of the mast/stem cell growth factor receptor (c-kit/CD117 in PF skin biopsies, as well as the role of IgE in the disease pathogenesis. Methods: Forty-four skin biopsies from patients affected by endemic PF (EPF (30 patients from El Bagre, Colombia, and 14 from the northeastern region of São Paulo State, Brazil, 48 control biopsies from Colombian and Brazilian endemic areas, and additional control biopsies from none endemic areas in Colombia and the USA non were studied. Immunohistochemistry (IHC was performed to evaluate skin biopsies with anti-mast cell tryptase (MCT, anti-c-kit and anti-IgE antibodies. We also searched for serum IgE in 30 EPF and 30 non-atopic controls from the El Bagre region via ELISA. In our El Bagre patients and controls, we also searched for IgE in skin samples by direct immunofluorescence. Results: In 100% of the EPF biopsies, MCT, c-kit and IgE were identified with stronger expression relative to control biopsies, especially in the inflammatory infiltrates around upper dermal blood vessels and dermal eccrine glands. IgE staining was positive along the BMZ in some EPF skin samples. The DIF results confirmed a linear deposition of IgE at the BMZ. Increased IgE serum levels were also noted in PF patients relative to controls.. Conclusions: In patients with EPF, the observed increased expression of MCT, c-kit and IgE in lesional skin, associated with higher serum IgE levels may indicate possible IgE participation in the antigenic response.

  14. Simultaneous suppression of epidermal growth factor receptor and c-erbB-2 reverses aneuploidy and malignant phenotype of a human ovarian carcinoma cell line.

    Science.gov (United States)

    Pack, Svetlana D; Alper, Ozgül M; Stromberg, Kurt; Augustus, Meena; Ozdemirli, Metin; Miermont, Anne M; Klus, Greg; Rusin, Marek; Slack, Rebecca; Hacker, Neville F; Ried, Thomas; Szallasi, Zoltan; Alper, Ozge

    2004-02-01

    Coexpression of epidermal growth factor receptor (EGFR) and c-erbB-2 in 47-68% of ovarian cancer cells indicate their strong association with tumor formation. We examined the effects of simultaneous antisense- or immunosuppression of EGFR and c-erbB-2 expression on the invasive phenotype, aneuploidy, and genotype of cultured human ovarian carcinoma cells (NIH:OVCAR-8). We report here that suppression of both EGFR and c-erbB-2 results in regression of aneuploidy and genomic imbalances in NIH:OVCAR-8 cells, restores a more normal phenotype, and results in a more normal gene expression profile. Combined with cytogenetic analysis, our data demonstrate that the regression of aneuploidy is due to the selective apoptosis of double antisense transfected cells with highly abnormal karyotype. PMID:14871800

  15. Extracellular acidification induces connective tissue growth factor production through proton-sensing receptor OGR1 in human airway smooth muscle cells

    International Nuclear Information System (INIS)

    Highlights: → The involvement of extracellular acidification in airway remodeling was investigated. → Extracellular acidification alone induced CTGF production in human ASMCs. → Extracellular acidification enhanced TGF-β-induced CTGF production in human ASMCs. → Proton-sensing receptor OGR1 was involved in acidic pH-stimulated CTGF production. → OGR1 may play an important role in airway remodeling in asthma. -- Abstract: Asthma is characterized by airway inflammation, hyper-responsiveness and remodeling. Extracellular acidification is known to be associated with severe asthma; however, the role of extracellular acidification in airway remodeling remains elusive. In the present study, the effects of acidification on the expression of connective tissue growth factor (CTGF), a critical factor involved in the formation of extracellular matrix proteins and hence airway remodeling, were examined in human airway smooth muscle cells (ASMCs). Acidic pH alone induced a substantial production of CTGF, and enhanced transforming growth factor (TGF)-β-induced CTGF mRNA and protein expression. The extracellular acidic pH-induced effects were inhibited by knockdown of a proton-sensing ovarian cancer G-protein-coupled receptor (OGR1) with its specific small interfering RNA and by addition of the Gq/11 protein-specific inhibitor, YM-254890, or the inositol-1,4,5-trisphosphate (IP3) receptor antagonist, 2-APB. In conclusion, extracellular acidification induces CTGF production through the OGR1/Gq/11 protein and inositol-1,4,5-trisphosphate-induced Ca2+ mobilization in human ASMCs.

  16. Production of two hemopoietic growth factors is differentially regulated in single T lymphocytes activated with an anti-T cell receptor antibody

    DEFF Research Database (Denmark)

    Kelso, A; Owens, T

    1988-01-01

    A method has been developed to measure the production by single activated T lymphocytes of two hemopoietic growth factors, granulocyte-macrophage CSF (GM-CSF) and multipotential CSF (multi-CSF or IL-3). When individual cells of the L3T4 (CD4)+ F23.1+ T cell clone E9.D4 were transferred...... by micromanipulation into wells coated with the monoclonal anti-T cell receptor antibody F23.1, up to 90% of cells produced CSF as detected by CSF-dependent hemopoietic cell lines. Production occurred in the absence of proliferation and did not require the addition of accessory cells or IL-2. Both the frequency of CSF...... in their total CSF titer with a mean value of about 0.05 U/cell. They also varied in their relative production of GM-CSF and multi-CSF. Thus, low producing cells secreted only GM-CSF whereas high producing cells also secreted multi-CSF. The failure of low producing cells to secrete multi-CSF was not genetically...

  17. Pancreatic adenocarcinoma upregulated factor (PAUF) confers resistance to pancreatic cancer cells against oncolytic parvovirus H-1 infection through IFNA receptor-mediated signaling.

    Science.gov (United States)

    Kaowinn, Sirichat; Cho, Il-Rae; Moon, Jeong; Jun, Seung Won; Kim, Chang Seok; Kang, Ho Young; Kim, Manbok; Koh, Sang Seok; Chung, Young-Hwa

    2015-04-01

    Pancreatic adenocarcinoma upregulated factor (PAUF), a novel oncogene, plays a crucial role in the development of pancreatic cancer, including its metastasis and proliferation. Therefore, PAUF-expressing pancreatic cancer cells could be important targets for oncolytic virus-mediated treatment. Panc-1 cells expressing PAUF (Panc-PAUF) showed relative resistance to parvovirus H-1 infection compared with Panc-1 cells expressing an empty vector (Panc-Vec). Of interest, expression of type I IFN-α receptor (IFNAR) was higher in Panc-PAUF cells than in Panc-Vec cells. Increased expression of IFNAR in turn increased the activation of Stat1 and Tyk2 in Panc-PAUF cells compared with that in Panc-Vec cells. Suppression of Tyk2 and Stat1, which are important downstream molecules for IFN-α signaling, sensitized pancreatic cancer cells to parvovirus H-1-mediated apoptosis. Further, constitutive suppression of PAUF sensitized Bxpc3 pancreatic cancer cells to parvovirus H-1 infection. Taken together, these results suggested that PAUF conferred resistance to pancreatic cancer cells against oncolytic parvovirus H-1 infection through IFNAR-mediated signaling. PMID:25727013

  18. A novel receptor – ligand pathway for entry of Francisella tularensis in monocyte-like THP-1 cells: interaction between surface nucleolin and bacterial elongation factor Tu

    Directory of Open Access Journals (Sweden)

    Charbit Alain

    2008-09-01

    Full Text Available Abstract Background Francisella tularensis, the causative agent of tularemia, is one of the most infectious human bacterial pathogens. It is phagocytosed by immune cells, such as monocytes and macrophages. The precise mechanisms that initiate bacterial uptake have not yet been elucidated. Participation of C3, CR3, class A scavenger receptors and mannose receptor in bacterial uptake have been already reported. However, contribution of an additional, as-yet-unidentified receptor for F. tularensis internalization has been suggested. Results We show here that cell-surface expressed nucleolin is a receptor for Francisella tularensis Live Vaccine Strain (LVS and promotes LVS binding and infection of human monocyte-like THP-1 cells. The HB-19 pseudopeptide that binds specifically carboxy-terminal RGG domain of nucleolin inhibits LVS binding and infection of monocyte-like THP-1 cells. In a pull-down assay, elongation factor Tu (EF-Tu, a GTP-binding protein involved in protein translation, usually found in cytoplasm, was recovered among LVS bacterial membrane proteins bound on RGG domain of nucleolin. A specific polyclonal murine antibody was raised against recombinant LVS EF-Tu. By fluorescence and electron microscopy experiments, we found that a fraction of EF-Tu could be detected at the bacterial surface. Anti-EF-Tu antibodies reduced LVS binding to monocyte-like THP-1 cells and impaired infection, even in absence of complement and complement receptors. Interaction between EF-Tu and nucleolin was illustrated by two different pull-down assays using recombinant EF-Tu proteins and either RGG domain of nucleolin or cell solubilized nucleolin. Discussion Altogether, our results demonstrate that the interaction between surface nucleolin and its bacterial ligand EF-Tu plays an important role in Francisella tularensis adhesion and entry process and may therefore facilitate invasion of host tissues. Since phagosomal escape and intra-cytosolic multiplication of

  19. Activation of AMP-activated kinase modulates sensitivity of glioma cells against epidermal growth factor receptor inhibition.

    Science.gov (United States)

    Hartel, Ines; Ronellenfitsch, Michael; Wanka, Christina; Wolking, Stefan; Steinbach, Joachim P; Rieger, Johannes

    2016-07-01

    The epidermal growth factor (EGFR) pathway is frequently activated in glioblastoma but the clinical efficacy of EGFR inhibitors in malignant glioma has been disappointing. The reasons for the failure of the mechanisms of resistance of these inhibitors are unclear, but may involve factors of the tumor microenvironment such as limited glucose availability and hypoxia. It was therefore examined whether glucose and oxygen influenced the response of glioma cells to EGFR inhibition. Decreased levels of glucose and oxygen led to resistance against the EGFR inhibitor PD153035, whereas high glucose amounts and normoxia sensitised glioma cells towards the inhibitor. Low levels of glucose and oxygen stimulated AMP-activated kinase (AMPK) in glioma cells. 2DG, an inhibitor of glycolysis, and the AMPK activator A769662 reduced glucose consumption, induced phosphorylation of AMPK and mimicked the effects of low glucose availability on the toxicity of PD153035. Similarly, 2DG reduced toxicity of imatinib in K562 leukemia cells. In contrast, inhibition of AMPK by compound C or by short-hairpin (sh)-mediated gene suppression increased cell death induced by the EGFR inhibitor and reverted the protective effects of 2DG and A769662. In conclusion, cytotoxicity of EGFR inhibition can be diminished by AMPK activation in glioma cells. These results may provide one explanation for the low activity of EGFR inhibitors in clinical trials and suggest antagonism of AMPK or of AMPK-regulated metabolic alterations as a promising approach to enhance their therapeutic efficacy. PMID:27121290

  20. Leptin facilitates proliferation of hepatic stellate cells through up-regulation of platelet-derived growth factor receptor

    International Nuclear Information System (INIS)

    In the present study, we investigated the effect of leptin on proliferation of hepatic stellate cells (HSCs) in vitro. Proliferation of 3-day cultured rat HSCs was assessed by incorporation of 5-bromo-2'-deoxyuridine (BrdU) into the nuclei. The percentages of BrdU-positive cells were increased in the presence of PDGF-BB (5 ng/ml) for 8 h as expected. Co-incubation with leptin (10-100 nM) potentiates this PDGF-dependent increase in BrdU positive cells in a dose-dependent manner. Messenger RNA for PDGF receptor α and β subunits was increased almost 2- to 3-fold by incubation with leptin for 6 h. Further, pre-incubation with leptin for 6 h enhanced PDGF-induced increases in phospho-p44/42 MAP kinase and phospho-Akt levels in a dose-dependent manner. In the same condition, however, leptin per se did not increase phospho-STAT 3 and phospho-p44/42 MAP kinase levels. Instead, leptin increased phospho-Akt levels in HSCs within 30 min, suggesting that the phosphatidylinositol 3 kinase (PI3K)/Akt pathway is involved in the mechanism by which leptin accelerates the proliferation of HSCs. In conclusion, the present study clearly indicated that leptin potentiates PDGF-dependent proliferative responses of HSCs in vitro

  1. Dominant negative and loss of function mutations of the c-kit (mast/stem cell growth factor receptor) proto-oncogene in human piebaldism

    Energy Technology Data Exchange (ETDEWEB)

    Spritz, R.A.; Giebel, L.B.; Holmes, S.A. (University of Wisconsin, Madison (United States))

    1992-02-01

    Piebaldism is an autosomal dominant disorder of melanocyte development and is characterized by congenital white parches of skin and hair from which melanocytes are completely absent. A similar disorder of the mouse, 'dominant white spotting' (W), results from mutations of the c-kit proto-oncogene, which encodes the cellular tyrosine kinases receptor for the mast/stem cell growth factor. The authors have identified c-kit gene mutations in three patients with piebaldism. A missense substitution (Phe[r arrow]Leu) at codon 584, within the tyrosine kinases domain, is associated with a severe piebald phenotype, whereas two different frameshifts, within codons 561 and 642, are both associated with a variable and relatively mild piebald phenotype. This is consistent with a possible 'dominant negative' effect of missense c-kit polypeptides on the function of the dimeric receptor.

  2. T cell receptor (TCR-transgenic CD8 lymphocytes rendered insensitive to transforming growth factor beta (TGFβ signaling mediate superior tumor regression in an animal model of adoptive cell therapy

    Directory of Open Access Journals (Sweden)

    Quatromoni Jon G

    2012-06-01

    Full Text Available Abstract Tumor antigen-reactive T cells must enter into an immunosuppressive tumor microenvironment, continue to produce cytokine and deliver apoptotic death signals to affect tumor regression. Many tumors produce transforming growth factor beta (TGFβ, which inhibits T cell activation, proliferation and cytotoxicity. In a murine model of adoptive cell therapy, we demonstrate that transgenic Pmel-1 CD8 T cells, rendered insensitive to TGFβ by transduction with a TGFβ dominant negative receptor II (DN, were more effective in mediating regression of established B16 melanoma. Smaller numbers of DN Pmel-1 T cells effectively mediated tumor regression and retained the ability to produce interferon-γ in the tumor microenvironment. These results support efforts to incorporate this DN receptor in clinical trials of adoptive cell therapy for cancer.

  3. Induction of FOXP3 expression in naive human CD4+FOXP3− T cells by T-cell receptor stimulation is transforming growth factor-β–dependent but does not confer a regulatory phenotype

    OpenAIRE

    Tran, Dat. Q.; Ramsey, Heather; Shevach, Ethan M.

    2007-01-01

    Thymic-derived natural T-regulatory cells (nTregs) are important for the induction of self-tolerance and the control of autoimmunity. Murine CD4+CD25−Foxp3− cells can be induced to express Foxp3 after T-cell receptor (TCR) activation in the presence of transforming growth factor β (TGFβ) and are phenotypically similar to nTregs. Some studies have suggested that TCR stimulation of human CD4+CD25− cells results in the induction of transient expression of FOXP3, but that the induced cells lack a...

  4. Insulin-like Growth Factor Receptor 1 mRNA Expression as a Prognostic Marker in Advanced Non-small Cell Lung Cancer

    DEFF Research Database (Denmark)

    Vilmar, Adam; Santoni-Rugiu, Eric; Cillas, Jesus Garcia-Fon;

    2014-01-01

    BACKGROUND: The insulin-like growth factor 1 receptor (IGF1R) has yet to be established as a biomarker in non-small cell lung cancer (NSCLC) but could prove useful in customized chemotherapy. We explored its prognostic value using both quantitative real-time reverse transcriptase polymerase chain......-points. RESULTS: Surgical tissue samples were available from 33 patients deemed inoperable. IGF1R status varied according to histopathology. Patients with tumors positive for IGF1R mRNA expression had a shorter progression-free and overall survival when compared to the negative sub-group (6.1 vs. 7.4 months, p=0...

  5. Research Progress on Resistance Mechanisms of Epidermal Growth Factor Receptor 
Tyrosine Kinase Inhibitors in Non-small Cell Lung Cancer

    Directory of Open Access Journals (Sweden)

    Yuan LI

    2012-02-01

    Full Text Available With a greater understanding of tumor biology, novel molecular-targeted strategies that block cancer progression pathways have been evaluated as a new therapeutic approach for treating non-small cell lung cancer (NSCLC. Epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs, such as gefitinib and erlotinib, show favorable response to EGFR mutant lung cancer in some populations of NSCLC patients. However, the efficacy of EGFR-TKIs is limited by either primary (de novo or acquired resistance after therapy. This review will focus on recently identified mechanisms of primary and acquired resistance to EGFR TKIs and strategies currently being employed to overcome resistance.

  6. Research Progress of Epidermal Growth Factor Receptor and Molecular-Targeted Therapy in Treatment of Non-Small Cell Lung Cancer

    Directory of Open Access Journals (Sweden)

    Xiaoyou Li

    2014-03-01

    Full Text Available Molecular target therapy has become a new approach in the treatment of advanced non-small cell lung cancer (NSCLC. The sensitivity of lung cancer to epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs has been found to be associated with gene mutationss in the tyrosine kinase domain of RGFR. However, not all EGFR gene mutationss are sensitive to EGFR-TKIs. The review was conducted to study the research progress of EGFR mutations and the sensitivity to EGFR-TKIs and the mechanism of resistance of molecular target therapy in NSCLC.

  7. Research Progress of Epidermal Growth Factor Receptor and Molecular-Targeted Therapy in Treatment of Non-Small Cell Lung Cancer

    Institute of Scientific and Technical Information of China (English)

    Li Xiaoyou; Feng Jifeng

    2014-01-01

    Molecular target therapy has become a new approach in the treatment of advanced non-small cell lung cancer (NSCLC). The sensitivity of lung cancer to epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) has been found to be associated with gene mutationss in the tyrosine kinase domain of RGFR. However, not all EGFR gene mutationss are sensitive to EGFR-TKIs. The review was conducted to study the research progress of EGFR mutations and the sensitivity to EGFR-TKIs and the mechanism of resistance of molecular target therapy in NSCLC.

  8. Epidermal Growth Factor Receptor in Prostate Cancer Derived Exosomes

    OpenAIRE

    Geetanjali Kharmate; Elham Hosseini-Beheshti; Josselin Caradec; Mei Yieng Chin; Tomlinson Guns, Emma S.

    2016-01-01

    Exosomes proteins and microRNAs have gained much attention as diagnostic tools and biomarker potential in various malignancies including prostate cancer (PCa). However, the role of exosomes and membrane-associated receptors, particularly epidermal growth factor receptor (EGFR) as mediators of cell proliferation and invasion in PCa progression remains unexplored. EGFR is frequently overexpressed and has been associated with aggressive forms of PCa. While PCa cells and tissues express EGFR, it ...

  9. Therapeutic Strategies for Patients With Metastatic Renal Cell Carcinoma in Whom First-Line Vascular Endothelial Growth Factor Receptor-Directed Therapies Fail.

    Science.gov (United States)

    Malouf, Gabriel G; Flippot, Ronan; Khayat, David

    2016-05-01

    Metastases are present in one third of renal cell carcinomas at diagnosis. The overall survival duration in metastatic renal cell carcinoma is approximately 22 months, which underlines the need for more effective systemic treatments. Therapies on the basis of antiangiogenic agents and inhibitors of the mammalian target of rapamycin have been approved for treatment of metastatic renal cell carcinoma, but only benefits for progression-free survival were demonstrated in the second-line setting. Fortunately, promising treatments are emerging, from new antiangiogenic agents to immune checkpoint inhibitors. For the first time, both an immune checkpoint inhibitor (nivolumab) and a dual inhibitor of the tyrosine kinases c-Met and vascular endothelial growth factor receptor-2 (cabozantinib) have demonstrated improvements in overall survival in the second-line setting. Finding the best sequence for these novel agents will be crucial to improving outcomes in patients with metastatic renal cell carcinoma. This article comprises both a systematic review of the literature and recommendations for second-line therapeutic strategies for patients with metastatic clear cell renal cell carcinoma in whom inhibitors of vascular endothelial growth factor have failed. PMID:27170687

  10. The role of peroxisome proliferator-activated receptor-β/δ in epidermal growth factor-induced HaCaT cell proliferation

    International Nuclear Information System (INIS)

    Epidermal growth factor (EGF) has been shown to be a potent mitogen for epidermal cells both in vitro and in vivo, thus contributing to the development of an organism. It has recently become clear that peroxisome proliferator-activated receptor-β/δ (PPARβ/δ) expression and activation is involved in the cell proliferation. However, little is known about the role of PPARβ/δ in EGF-induced proliferation of HaCaT keratinocytes. In this study, HaCaT cells were cultured in the presence and absence of EGF and we identified that EGF induced an increase of PPARβ/δ mRNA and protein level expression in time-dependent and dose-dependent manner, and AG1487, an EGF receptor (EGFR) special inhibitor, caused attenuation of PPARβ/δ protein expression. Electrophoretic mobility shift assay (EMSA) revealed that EGF significantly increased PPARβ/δ binding activity in HaCaT keratinocytes. Antisense phosphorothioate oligonucleotides (asODNs) against PPARβ/δ caused selectively inhibition of PPARβ/δ protein content induced by EGF and significantly attenuated EGF-mediated cell proliferation. Treatment of the cells with L165041, a specific synthetic ligand for PPARβ/δ, significantly enhanced EGF-mediated cell proliferation. Finally, c-Jun ablation inhibited PPARβ/δ up-regulation induced by EGF, and chromatin immunoprecipitation (ChIP) showed that c-Jun bound to the PPARβ/δ promoter and the binding increased in EGF-stimulated cells. These results demonstrate that EGF induces PPARβ/δ expression in a c-Jun-dependent manner and PPARβ/δ plays a vital role in EGF-stimulated proliferation of HaCaT cells

  11. Effect of vascular endothelial growth factor and its receptor KDR on human airway smooth muscle cells proliferation

    Institute of Scientific and Technical Information of China (English)

    ZOU hui; XU Yong-jian; ZHANG Zhen-xiang

    2005-01-01

    @@ Airway remodeling with inflammatory cell infiltration, epithelial shedding, basement membrane thickening and increased mass of airway smooth muscle (ASM) is an important determinant of bronchial obstruction and hyperresponsiveness in asthma.1,2 Increased ASM mass is by far the most important abnormality responsible for excessive airway narrowing and compliance of the airway wall in asthma.1-3 ASM growth and proliferation in asthma is a complex phenomenon of which the underlying mechanisms are difficult to investigate in vivo. The increased amount of ASM in asthmatics is an indication of abnormal cell proliferation and growth, but little is known regarding the molecular mechanisms and factors that regulate ASM cell proliferation and growth in asthma.

  12. Decreased expression of the mannose 6- phosphate/insulin-like growth factor-II receptor promotes growth of human breast cancer cells

    International Nuclear Information System (INIS)

    Loss or mutation of the mannose 6-phosphate/insulin-like growth factor-II receptor (M6P/IGF2R) has been found in breast cancer. However, whether or not decreased levels of functional M6P/IGF2R directly contribute to the process of carcinogenesis needs to be further verified by functional studies. In this study, using viral and ribozyme strategies we reduced the expression of M6P/IGF2R in human breast cancer cells and then examined the effect on growth and apoptosis of these cells. Our results showed that infection of MCF-7 cells with the adenovirus carrying a ribozyme targeted against the M6P/IGF2R mRNA dramatically reduced the level of transcripts and the functional activity of M6P/IGF2R in these cells. Accordingly, cells treated with the ribozyme exhibited a higher growth rate and a lower apoptotic index than control cells (infected with a control vector). Furthermore, decreased expression of M6P/IGF2R enhanced IGF-II-induced proliferation and reduced cell susceptibility to TNF-induced apoptosis. These results suggest that M6P/IGF2R functions as a growth suppressor and its loss or mutation may contribute to development and progression of cancer. This study also demonstrates that adenoviral delivery of the ribozyme provides a useful tool for investigating the role of M6P/IGF2R in regulation of cell growth

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

    Science.gov (United States)

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

    2014-01-01

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

  14. Epidermal growth factor receptor signalling in human breast cancer cells operates parallel to estrogen receptor α signalling and results in tamoxifen insensitive proliferation.

    NARCIS (Netherlands)

    Moerkens, M.; Zhang, Y.; Wester, L.; Water, van de B.; Meerman, J.H.N.

    2014-01-01

    BACKGROUND Tamoxifen resistance is a major problem in the treatment of estrogen receptor (ER) α -positive breast cancer patients. Although the mechanisms behind tamoxifen resistance are still not completely understood, clinical data suggests that increased expression of receptor tyrosine kinases is

  15. miR-17-5p targets the p300/CBP-associated factor and modulates androgen receptor transcriptional activity in cultured prostate cancer cells

    International Nuclear Information System (INIS)

    Androgen receptor (AR) signalling is critical to the initiation and progression of prostate cancer (PCa). Transcriptional activity of AR involves chromatin recruitment of co-activators, including the p300/CBP-associated factor (PCAF). Distinct miRNA expression profiles have been identified in PCa cells during the development and progression of the disease. Whether miRNAs regulate PCAF expression in PCa cells to regulate AR transcriptional activity is still unclear. Expression of PCAF was investigated in several PCa cell lines by qRT-PCR, Western blot, and immunocytochemistry. The effects of PCAF expression on AR-regulated transcriptional activity and cell growth in PCa cells were determined by chromatin immunoprecipitation, reporter gene construct analysis, and MTS assay. Targeting of PCAF by miR-17-5p was evaluated using the luciferase reporter assay. PCAF was upregulated in several PCa cell lines. Upregulation of PCAF promoted AR transcriptional activation and cell growth in cultured PCa cells. Expression of PCAF in PCa cells was associated with the downregulation of miR-17-5p. Targeting of the 3’-untranslated region of PCAF mRNA by miR-17-5p caused translational suppression and RNA degradation, and, consequently, modulation of AR transcriptional activity in PCa cells. PCAF is upregulated in cultured PCa cells, and upregulation of PCAF is associated with the downregulation of miR-17-5p. Targeting of PCAF by miR-17-5p modulates AR transcriptional activity and cell growth in cultured PCa cells

  16. Comparison of the epidermal growth factor receptor protein expression between primary non-small cell lung cancer and paired lymph node metastases: implications for targeted nuclide radiotherapy

    Directory of Open Access Journals (Sweden)

    Zhang Chen

    2010-01-01

    Full Text Available Abstract Background The knowledge of Epidermal growth factor receptor (EGFR expression in metastases of NSCLC was limited. In receptor-mediated targeted nuclide radiotherapy, tumor cells are killed with delivered radiation and therapeutic efficiency is mainly dependent on the receptor expression. Thus, the level and stability of receptor expression in both primary tumors and corresponding metastases is crucial in the assessment of a receptor as target. The goal of this study was to evaluate whether EGFR is suitable as target for clinical therapy. Methods Expression of EGFR was investigated immunohistochemically in paired samples of lymph node metastases and corresponding NSCLC primary lesions (n = 51. EGFR expression was scored as 0, 1+, 2+ or 3+. Results Positive (1+, 2+ or 3+ EGFR immunostaining was evident in 36 of 47 (76.6% analysed NSCLC primary tumors, and in 78.7% of the corresponding lymph node metastases. When EGFR expression is classified as positive or negative, discordance between the primary tumors and the corresponding metastases was observed in 5 cases (10.6%. EGFR overexpression (2+ or 3+ was found in 53.2% (25/47 of the NSCLC primary tumors and 59.6% of the corresponding metastases. Nine out of the 47 paired samples (19.2% were discordant: Only three patients who had EGFR overexpression in the primary tumors showed EGFR downregulation (0 or 1+ in lymph node metastases, while six patients changed the other way around. Conclusions The EGFR expression in the primary tumor and the corresponding metastasis is discordant in about 10% of the patients. When overexpression is considered, the discordance is observed in about 20% of the cases. However, concerning EGFR overexpression in the primary tumors, similar expression in the metastases could be predicted with a reasonably high probability, which is encouraging for testing of EGFR targeted nuclide radiotherapy.

  17. C1q-tumour necrosis factor-related protein 8 (CTRP8) is a novel interaction partner of relaxin receptor RXFP1 in human brain cancer cells.

    Science.gov (United States)

    Glogowska, Aleksandra; Kunanuvat, Usakorn; Stetefeld, Jörg; Patel, Trushar R; Thanasupawat, Thatchawan; Krcek, Jerry; Weber, Ekkehard; Wong, G William; Del Bigio, Marc R; Hoang-Vu, Cuong; Hombach-Klonisch, Sabine; Klonisch, Thomas

    2013-12-01

    We report a novel ligand-receptor system composed of the leucine-rich G-protein-coupled relaxin receptor, RXFP1, and the C1q-tumour necrosis factor-related protein 8 (CTRP8) in human primary brain cancer, a tumour entity devoid of the classical RXFP1 ligands, RLN1-3. In structural homology studies and computational docking experiments we delineated the N-terminal region of the globular C1q region of CTRP8 and the leucine-rich repeat units 7 and 8 of RXFP1 to mediate this new ligand-receptor interaction. CTRP8 secreted from HEK293T cells, recombinant human (rh) CTRP8, and short synthetic peptides derived from the C1q globular domain of human CTRP8 caused the activation of RXFP1 as determined by elevated intracellular cAMP levels and the induction of a marked pro-migratory phenotype in established glioblastoma (GB) cell lines and primary cells from GB patients. Employing a small competitor peptide, we were able to disrupt the CTRP8-RXFP1-induced increased GB motility. The CTRP8-RXFP1-mediated migration in GB cells involves the activation of PI3K and specific protein kinase C pathways and the increased production/secretion of the potent lysosomal protease cathepsin B (cathB), a known prognostic marker of GB. Specific inhibition of CTRP8-induced cathB activity effectively blocked the ability of primary GB to invade laminin matrices. Finally, co-immunoprecipitation studies revealed the direct interaction of human CTRP8 with RXFP1. Our results support a therapeutic approach in GB aimed at targeting multiple steps of the CTRP8-RXFP1 signalling pathway by a combined inhibitor and peptide-based strategy to block GB dissemination within the brain. PMID:24014093

  18. The ETS domain transcription factor ELK1 directs a critical component of growth signaling by the androgen receptor in prostate cancer cells.

    Science.gov (United States)

    Patki, Mugdha; Chari, Venkatesh; Sivakumaran, Suneethi; Gonit, Mesfin; Trumbly, Robert; Ratnam, Manohar

    2013-04-19

    The androgen receptor (AR) is essential for diverse aspects of prostate development and function. Molecular mechanisms by which prostate cancer (PC) cells redirect AR signaling to genes that primarily support growth are unclear. A systematic search for critical AR-tethering proteins led to ELK1, an ETS transcription factor of the ternary complex factor subfamily. Although genetically redundant, ELK1 was obligatory for AR-dependent growth and clonogenic survival in both hormone-dependent PC and castration-recurrent PC cells but not for AR-negative cell growth. AR required ELK1 to up-regulate a major subset of its target genes that was strongly and primarily enriched for cell growth functions. AR functioned as a coactivator of ELK1 by association through its A/B domain, bypassing the classical mechanism of ELK1 activation by phosphorylation and without inducing ternary complex target genes. The ELK1-AR synergy per se was ligand-independent, although it required ligand for nuclear localization of AR as targeting the AR A/B domain to the nucleus recapitulated the action of hormone; accordingly, Casodex was a poor antagonist of the synergy. ELK3, the closest substitute for ELK1 in structure/function and genome recognition, did not interact with AR. ELK1 thus directs selective and sustained gene induction that is a substantial and critical component of growth signaling by AR in PC cells. The ELK1-AR interaction offers a functionally tumor-selective drug target. PMID:23426362

  19. Silencer of death domains controls cell death through tumour necrosis factor-receptor 1 and caspase-10 in acute lymphoblastic leukemia.

    Directory of Open Access Journals (Sweden)

    Adam Cisterne

    Full Text Available Resistance to apoptosis remains a significant problem in drug resistance and treatment failure in malignant disease. NO-aspirin is a novel drug that has efficacy against a number of solid tumours, and can inhibit Wnt signaling, and although we have shown Wnt signaling to be important for acute lymphoblastic leukemia (ALL cell proliferation and survival inhibition of Wnt signaling does not appear to be involved in the induction of ALL cell death. Treatment of B lineage ALL cell lines and patient ALL cells with NO-aspirin induced rapid apoptotic cell death mediated via the extrinsic death pathway. Apoptosis was dependent on caspase-10 in association with the formation of the death-inducing signaling complex (DISC incorporating pro-caspase-10 and tumor necrosis factor receptor 1 (TNF-R1. There was no measurable increase in TNF-R1 or TNF-α in response to NO-aspirin, suggesting that the process was ligand-independent. Consistent with this, expression of silencer of death domain (SODD was reduced following NO-aspirin exposure and lentiviral mediated shRNA knockdown of SODD suppressed expansion of transduced cells confirming the importance of SODD for ALL cell survival. Considering that SODD and caspase-10 are frequently over-expressed in ALL, interfering with these proteins may provide a new strategy for the treatment of this and potentially other cancers.

  20. Silencer of Death Domains Controls Cell Death through Tumour Necrosis Factor-Receptor 1 and Caspase-10 in Acute Lymphoblastic Leukemia

    Science.gov (United States)

    Khan, Naveed I.; Welschinger, Robert; Basnett, Jordan; Fung, Carina; Rizos, Helen; Bradstock, Kenneth F.; Bendall, Linda J.

    2014-01-01

    Resistance to apoptosis remains a significant problem in drug resistance and treatment failure in malignant disease. NO-aspirin is a novel drug that has efficacy against a number of solid tumours, and can inhibit Wnt signaling, and although we have shown Wnt signaling to be important for acute lymphoblastic leukemia (ALL) cell proliferation and survival inhibition of Wnt signaling does not appear to be involved in the induction of ALL cell death. Treatment of B lineage ALL cell lines and patient ALL cells with NO-aspirin induced rapid apoptotic cell death mediated via the extrinsic death pathway. Apoptosis was dependent on caspase-10 in association with the formation of the death-inducing signaling complex (DISC) incorporating pro-caspase-10 and tumor necrosis factor receptor 1 (TNF-R1). There was no measurable increase in TNF-R1 or TNF-α in response to NO-aspirin, suggesting that the process was ligand-independent. Consistent with this, expression of silencer of death domain (SODD) was reduced following NO-aspirin exposure and lentiviral mediated shRNA knockdown of SODD suppressed expansion of transduced cells confirming the importance of SODD for ALL cell survival. Considering that SODD and caspase-10 are frequently over-expressed in ALL, interfering with these proteins may provide a new strategy for the treatment of this and potentially other cancers. PMID:25061812

  1. Prolonged exposure of colon cancer cells to the epidermal growth factor receptor inhibitor gefitinib (IressaTM) and to the antiangiogenic agent ZD6474: Cytotoxic and biomolecular effects

    Institute of Scientific and Technical Information of China (English)

    Amalia Azzariti; Letizia Porcelli; Jian-Ming Xu; Grazia Maria Simone; Angelo Paradiso

    2006-01-01

    AIM: To analyze the biological effects of prolonged in vitro exposure of HT-29 and LoVo colon cancer cell lines to gefitinib (Iressa TM), an inhibitor of epidermal growth factor receptor (EGFR) activity, and ZD6474, an inhibitor of both KDR and EGFR activities. METHODS: Cells were treated with each drug for up to 2 wk using either a continuous or an intermittent (4 d of drug exposure followed by 3 d of washout each week) schedule.RESULTS: In both cell types, prolonged exposure (up to 14 d) to gefitinib or ZD6474 produced a similar inhibition of cell growth that was persistent and independent of the treatment schedule. The effects on cell growth were associated with a pronounced inhibition of p-EGFR and/ or p-KDR expression. Treatment with gefitinib or ZD6474 also inhibited the expression of EGFR downstream signal molecules, p-Erk1/2 and p-Akt, although the magnitude of these effects varied between treatments and cell lines. Furthermore, expression of the drug resistance-related protein ABCG2 was shown to significantly increase after 14 d of continuous exposure to the two drugs. CONCLUSION: We conclude that long-term exposure of colon cancer cells to gefitinib and ZD6474 does not modify their cytotoxic effects but it might have an effect on sensitivity to classical cytotoxic drugs.

  2. Nexus of signaling and endocytosis in oncogenesis driven by non-small cell lung cancer-associated epidermal growth factor receptor mutants.

    Science.gov (United States)

    Chung, Byung Min; Tom, Eric; Zutshi, Neha; Bielecki, Timothy Alan; Band, Vimla; Band, Hamid

    2014-12-10

    Epidermal growth factor receptor (EGFR) controls a wide range of cellular processes, and aberrant EGFR signaling as a result of receptor overexpression and/or mutation occurs in many types of cancer. Tumor cells in non-small cell lung cancer (NSCLC) patients that harbor EGFR kinase domain mutations exhibit oncogene addiction to mutant EGFR, which confers high sensitivity to tyrosine kinase inhibitors (TKIs). As patients invariably develop resistance to TKIs, it is important to delineate the cell biological basis of mutant EGFR-induced cellular transformation since components of these pathways can serve as alternate therapeutic targets to preempt or overcome resistance. NSCLC-associated EGFR mutants are constitutively-active and induce ligand-independent transformation in nonmalignant cell lines. Emerging data suggest that a number of factors are critical for the mutant EGFR-dependent tumorigenicity, and bypassing the effects of TKIs on these pathways promotes drug resistance. For example, activation of downstream pathways such as Akt, Erk, STAT3 and Src is critical for mutant EGFR-mediated biological processes. It is now well-established that the potency and spatiotemporal features of cellular signaling by receptor tyrosine kinases such as EGFR, as well as the specific pathways activated, is determined by the nature of endocytic traffic pathways through which the active receptors traverse. Recent evidence indicates that NSCLC-associated mutant EGFRs exhibit altered endocytic trafficking and they exhibit reduced Cbl ubiquitin ligase-mediated lysosomal downregulation. More recent work has shown that mutant EGFRs undergo ligand-independent traffic into the endocytic recycling compartment, a behavior that plays a key role in Src pathway activation and oncogenesis. These studies are beginning to delineate the close nexus between signaling and endocytic traffic of EGFR mutants as a key driver of oncogenic processes. Therefore, in this review, we will discuss the links

  3. Transcription factor activity of estrogen receptor α activation upon nonylphenol or bisphenol A treatment enhances the in vitro proliferation, invasion, and migration of neuroblastoma cells

    Science.gov (United States)

    Ma, Hongda; Yao, Yao; Wang, Changli; Zhang, Liyu; Cheng, Long; Wang, Yiren; Wang, Tao; Liang, Erguang; Jia, Hui; Ye, Qinong; Hou, Mingxiao; Feng, Fan

    2016-01-01

    Many kinds of endocrine-disrupting chemicals (EDCs), for example, the environmental estrogens bisphenol A and nonylphenol, may regulate the activity of estrogen receptor α (ERα) and therefore induce potential disruption of normal endocrine function. However, the involvement of EDCs in human cancers, especially in endocrine-related cancer neuroblastoma regulation, is not very clear. In this work, results showed that upon bisphenol A or nonylphenol treatment, the transcription factor activity of ERα was significantly increased in neuroblastoma cell line SH-SY5Y. Bisphenol A and nonylphenol could enhance ERα activity via recruiting it to the target gene promoter. Furthermore, treatment of bisphenol A and nonylphenol enhanced the in vitro proliferation, invasion, and migration ability of neuroblastoma cells. By investigating the role of EDC-induced ERα upregulation, our data extend the understanding of the function of EDCs and further suggest that ERα might be a potential therapeutic target in human neuroblastoma treatment. PMID:27366082

  4. ERas protein is overexpressed and binds to the activated platelet-derived growth factor β receptor in bovine urothelial tumour cells associated with papillomavirus infection.

    Science.gov (United States)

    Russo, Valeria; Roperto, Franco; Esposito, Iolanda; Ceccarelli, Dora Maria; Zizzo, Nicola; Leonardi, Leonardo; Capparelli, Rosanna; Borzacchiello, Giuseppe; Roperto, Sante

    2016-06-01

    Embryonic stem cell-expressed Ras (ERas) encodes a constitutively active form of guanosine triphosphatase (GTPase) that binds to and activates phosphatidylinositol 3 kinase (PI3K), which in turn phosphorylates and activates downstream targets such as Akt. The current study evaluated ERas regulation and expression in papillomavirus-associated urothelial tumours in cattle grazing on lands rich in bracken fern. ERas was found upregulated and overexpressed by PCR, real time PCR and Western blot. Furthermore, protein overexpression was also confirmed by immunohistochemistry. ERas was found to interact physically and colocalise with the activated platelet derived growth factor β receptor (PDGFβR) by coimmunoprecipitation and laser scanning confocal investigations. Phosphorylation of Akt, a downstream effector both of ERas and PDGFβR, appeared to be increased in urothelial tumour cells. Altogether, these data indicate that ERas/PDGFβR complex could play a role in the pathogenesis of bovine papillomavirus-associated bladder neoplasia. PMID:27256024

  5. In Vitro Responsiveness of Glioma Cell Lines to Multimodality Treatment With Radiotherapy, Temozolomide, and Epidermal Growth Factor Receptor Inhibition With Cetuximab

    International Nuclear Information System (INIS)

    Background: The majority of glioblastoma multiforme (GBM) cells express the epidermal growth factor receptor (EGFR). The present study evaluates the combination of temozolomide (TMZ), EGFR inhibition, and radiotherapy (RT) in GBM cell lines. Methods and Materials: Human GBM cell lines U87, LN229, LN18, NCH 82, and NCH 89 were treated with various combinations of TMZ, RT, and the monoclonal EGFR antibody cetuximab. Responsiveness of glioma cells to the combination treatment was measured by clonogenic survival. Results: Overall, double and triple combinations of RT, TMZ, and cetuximab lead to additive cytotoxic effects (independent toxicity). A notable exception was observed for U87 and LN 18 cell lines, where the combination of TMZ and cetuximab showed substantial antagonism. Interestingly, in these two cell lines, the combination of RT with cetuximab resulted in a substantial increase in cell killing over that expected for independent toxicity. The triple combination with RT, cetuximab, and TMZ was nearly able to overcome the antagonism for the TMZ/cetuximab combination in U87, however only marginally in LN18, GBM cell lines. Conclusion: It appears that EGFR expression is not correlated with cytotoxic effects exerted by cetuximab. Combination treatment with TMZ, cetuximab and radiation resulted in independent toxicity in three out of five cell lines evaluated, the antagonistic effect of the TMZ/cetuximab combination in two cell lines could indicate that TMZ preferentially kills cetuximab-resistant cells, suggesting for some cross-talk between toxicity mechanisms. Expression of EGFR was no surrogate marker for responsiveness to cetuximab, alone or in combination with RT and TMZ

  6. Insulin-like growth factor-1 receptor protein expression and gene copy number alterations in non-small cell lung carcinomas.

    Science.gov (United States)

    Tsuta, Koji; Mimae, Takahiro; Nitta, Hiroaki; Yoshida, Akihiko; Maeshima, Akiko M; Asamura, Hisao; Grogan, Thomas M; Furuta, Koh; Tsuda, Hitoshi

    2013-06-01

    Insulin-like growth factor-1 receptor (IGF-1R) is a tyrosine kinase receptor implicated in the pathogenesis of several malignancies and is potentially an attractive target for anticancer treatment. In this study, we included 379 patients who underwent surgical resection (179 diagnosed as having adenocarcinoma [ADC]; 150, squamous cell carcinoma [SCC]; 41, sarcomatoid carcinoma and 9, large cell carcinoma). IGF-1R expression and gene copy number were assessed by immunohistochemistry and bright-field in situ hybridization (BISH), respectively. IGF-1R expression in non-small cell lung carcinoma was observed in 41.4% of samples and was more prevalent in SCC (69.3%) than in ADC (25.1%), large cell carcinoma (33.3%), and sarcomatoid carcinoma (12.2%) (P < .001). Among ADCs, most mucinous ADCs (75%) showed strong membranous staining with the IGF-1R antibody. Compared with protein expression, IGF-1R gene alteration was rare (8.4%). A statistically significant correlation between IGF-1R expression and positive IGF-1R BISH was observed (γ = 0.762, P < .001). IGF-1R-positive tumors were more common in smokers (P = .004), and these tumors were larger (P = .006) than the IGF-1R-negative tumors. IGF-1R BISH positivity was not correlated with any clinicopathologic factor. IGF-1R expression and IGF-1R BISH positivity were not correlated with overall survival. IGF-1R is highly expressed in SCC and mucinous ADC, although copy number alterations in the IGF-1R gene were rare. These findings may have important implications for future anti-IGF-1R therapeutic approaches. PMID:23266446

  7. Inhibition of insulin-like growth factor-1 receptor signaling enhances growth-inhibitory and proapoptotic effects of gefitinib (Iressa) in human breast cancer cells

    International Nuclear Information System (INIS)

    Gefitinib (Iressa, ZD 1839, AstraZeneca) blocks the tyrosine kinase activity of the epidermal growth factor receptor (EGFR) and inhibits proliferation of several human cancer cell types including breast cancer. Phase II clinical trials with gefitinib monotherapy showed an objective response of 9 to 19% in non-small-cell lung cancer patients and less than 10% for breast cancer, and phase III results have indicated no benefit of gefitinib in combination with chemotherapy over chemotherapy alone. In order to improve the antineoplastic activity of gefitinib, we investigated the effects of blocking the signalling of the insulin-like growth factor 1 receptor (IGF-1R), a tyrosine kinase with a crucial role in malignancy that is coexpressed with EGFR in most human primary breast carcinomas. AG1024 (an inhibitor of IGF-1R) was used with gefitinib for treatment of MDA468, MDA231, SK-BR-3, and MCF-7 breast cancer lines, which express similar levels of IGF-1R but varying levels of EGFR. Proliferation assays, apoptosis induction studies, and Western blot analyses were conducted with cells treated with AG1024 and gefitinib as single agents and in combination. Gefitinib and AG1024 reduced proliferation in all lines when used as single agents, and when used in combination revealed an additive-to-synergistic effect on cell growth inhibition. Flow cytometry measurements of cells stained with annexin V-propidium iodide and cells stained for caspase-3 activation indicated that adding an IGF-1R-targeting strategy to gefitinib results in higher levels of apoptosis than are achieved with gefitinib alone. Gefitinib either reduced or completely inhibited p42/p44 Erk kinase phosphorylation, depending on the cell line, while Akt phosphorylation was reduced by a combination of the two agents. Overexpression of IGF-1R in SK-BR-3 cells was sufficient to cause a marked enhancement in gefitinib resistance. These results indicate that IGF-1R signaling reduces the antiproliferative effects of

  8. Novel epidermal growth factor receptor pathway mediates release of human β-defensin 3 from Helicobacter pylori-infected gastric epithelial cells.

    Science.gov (United States)

    Muhammad, Jibran S; Zaidi, Syed F; Zhou, Yue; Sakurai, Hiroaki; Sugiyama, Toshiro

    2016-04-01

    Persistent Helicobacter pylori (H. pylori) infection in hostile gastric mucosa can result in gastric diseases. Helicobacter pylori induces to express antimicrobial peptides from gastric epithelial cells, especially human β-defensin 3 (hBD3), as an innate immune response, and this expression of hBD3 is mediated by epidermal growth factor receptor (EGFR) activation. In this study, we found that phosphorylation of a serine residue of EGFR via transforming growth factor β-activated kinase-1 (TAK1), and subsequent p38α activation is essential for H. pylori-induced hBD3 release from gastric epithelial cells. We showed that this pathway was dependent on H. pylori type IV secretion system and was independent of H. pylori-derived CagA or peptidoglycan. H. pylori infection induced phosphorylation of serine residue of EGFR, and this phosphorylation was followed by internalization of EGFR; consequently, hBD3 was released at an early phase of the infection. In the presence of TAK1 or p38α inhibitors, synthesis of hBD3 was completely inhibited. Similar results were observed in EGFR-, TAK1- or p38α-knockdown cells. However, NOD1 knockdown in gastric epithelial cells did not inhibit hBD3 induction. Our study has firstly demonstrated that this novel EGFR activating pathway functioned to induce hBD3 at an early phase of H. pylori infection. PMID:26733497

  9. Ciliary Neurotrophic Factor Receptor Regulation of Adult Forebrain Neurogenesis

    OpenAIRE

    Lee, Nancy; Batt, Myra K.; Cronier, Brigitte A.; Jackson, Michele C.; Bruno Garza, Jennifer L; Trinh, Dennis S.; Mason, Carter O.; Spearry, Rachel P.; Bhattacharya, Shayon; Robitz, Rachel; Nakafuku, Masato; MacLennan, A. John

    2013-01-01

    Appropriately targeted manipulation of endogenous neural stem progenitor (NSP) cells may contribute to therapies for trauma, stroke, and neurodegenerative disease. A prerequisite to such therapies is a better understanding of the mechanisms regulating adult NSP cells in vivo. Indirect data suggest that endogenous ciliary neurotrophic factor (CNTF) receptor signaling may inhibit neuronal differentiation of NSP cells. We challenged subventricular zone (SVZ) cells in vivo with low concentrations...

  10. Identification of Insulin-Like Growth Factor-I Receptor (IGF-IR Gene Promoter-Binding Proteins in Estrogen Receptor (ER-Positive and ER-Depleted Breast Cancer Cells

    Directory of Open Access Journals (Sweden)

    Rive Sarfstein

    2010-03-01

    Full Text Available The insulin-like growth factor I receptor (IGF-IR has been implicated in the etiology of breast cancer. Overexpression of the IGF-IR gene is a typical feature of most primary breast cancers, whereas low IGF-IR levels are seen at advanced stages. Hence, evaluation of IGF-IR levels might be important for assessing prognosis. In the present study, we employed a proteomic approach based on DNA affinity chromatography followed either by mass spectroscopy (MS or Western blot analysis to identify transcription factors that may associate with the IGF-IR promoter in estrogen receptor (ER-positive and ER-depleted breast cancer cells. A biotinylated IGF-IR promoter fragment was bound to streptavidin magnetic beads and incubated with nuclear extracts of breast cancer cells. IGF-IR promoter-binding proteins were eluted with high salt and analyzed by MS and Western blots. Among the proteins that were found to bind to the IGF-IR promoter we identified zinc finger transcription factors Sp1 and KLF6, ER-, p53, c-jun, and poly (ADP-ribosylation polymerase. Furthermore, chromatin immune-precipitation (ChIP analysis confirmed the direct in vivo binding of some of these transcription factors to IGF-IR promoter DNA. The functional relevance of binding data was assessed by cotransfection experiments with specific expression vectors along with an IGF-IR promoter reporter. In summary, we identified nuclear proteins that are potentially responsible for the differential expression of the IGF-IR gene in ER-positive and ER-depleted breast cancer cells.

  11. Identification of Insulin-Like Growth Factor-I Receptor (IGF-IR) Gene Promoter-Binding Proteins in Estrogen Receptor (ER)-Positive and ER-Depleted Breast Cancer Cells

    International Nuclear Information System (INIS)

    The insulin-like growth factor I receptor (IGF-IR) has been implicated in the etiology of breast cancer. Overexpression of the IGF-IR gene is a typical feature of most primary breast cancers, whereas low IGF-IR levels are seen at advanced stages. Hence, evaluation of IGF-IR levels might be important for assessing prognosis. In the present study, we employed a proteomic approach based on DNA affinity chromatography followed either by mass spectroscopy (MS) or Western blot analysis to identify transcription factors that may associate with the IGF-IR promoter in estrogen receptor (ER)-positive and ER-depleted breast cancer cells. A biotinylated IGF-IR promoter fragment was bound to streptavidin magnetic beads and incubated with nuclear extracts of breast cancer cells. IGF-IR promoter-binding proteins were eluted with high salt and analyzed by MS and Western blots. Among the proteins that were found to bind to the IGF-IR promoter we identified zinc finger transcription factors Sp1 and KLF6, ER-α, p53, c-jun, and poly (ADP-ribosylation) polymerase. Furthermore, chromatin immune-precipitation (ChIP) analysis confirmed the direct in vivo binding of some of these transcription factors to IGF-IR promoter DNA. The functional relevance of binding data was assessed by cotransfection experiments with specific expression vectors along with an IGF-IR promoter reporter. In summary, we identified nuclear proteins that are potentially responsible for the differential expression of the IGF-IR gene in ER-positive and ER-depleted breast cancer cells

  12. The prognostic value of epidermal growth factor receptor is related to tumor differentiation and the overall treatment time of radiotherapy in squamous cell carcinomas of the head and neck

    DEFF Research Database (Denmark)

    Eriksen, Jesper Grau; Steiniche, Torben; Askaa, Jon;

    2004-01-01

    Accelerated repopulation in head-and-neck carcinomas might be related to the expression of proliferative factors such as epidermal growth factor receptor (EGFr). The present study focuses on the prognostic value of EGFr for T-site control and the relation to tumor cell differentiation and overall...

  13. Fibroblast growth factor 2 inhibits up-regulation of bone morphogenic proteins and their receptors during osteoblastic differentiation of human mesenchymal stem cells

    International Nuclear Information System (INIS)

    Highlights: ► FGF modulates BMPs pathway in HMSCs by down-regulating BMP/BMPR expression. ► This effect is mediated by ERK and JNK MAPKs pathways. ► Crosstalk between FGF and BMPs must be taken into account in skeletal bioengineering. ► It must also be considered in the use of recombinant BMPs in orthopedic and spine surgeries. -- Abstract: Understanding the interactions between growth factors and bone morphogenic proteins (BMPs) signaling remains a crucial issue to optimize the use of human mesenchymal stem cells (HMSCs) and BMPs in therapeutic perspectives and bone tissue engineering. BMPs are potent inducers of osteoblastic differentiation. They exert their actions via BMP receptors (BMPR), including BMPR1A, BMPR1B and BMPR2. Fibroblast growth factor 2 (FGF2) is expressed by cells of the osteoblastic lineage, increases their proliferation and is secreted during the healing process of fractures or in surgery bone sites. We hypothesized that FGF2 might influence HMSC osteoblastic differentiation by modulating expressions of BMPs and their receptors. BMP2, BMP4, BMPR1A and mainly BMPR1B expressions were up-regulated during this differentiation. FGF2 inhibited HMSCs osteoblastic differentiation and the up-regulation of BMPs and BMPR. This effect was prevented by inhibiting the ERK or JNK mitogen-activated protein kinases which are known to be activated by FGF2. These data provide a mechanism explaining the inhibitory effect of FGF2 on osteoblastic differentiation of HMSCs. These crosstalks between growth and osteogenic factors should be considered in the use of recombinant BMPs in therapeutic purpose of fracture repair or skeletal bioengineering.

  14. Fibroblast growth factor 2 inhibits up-regulation of bone morphogenic proteins and their receptors during osteoblastic differentiation of human mesenchymal stem cells

    Energy Technology Data Exchange (ETDEWEB)

    Biver, Emmanuel, E-mail: ebiver@yahoo.fr [Physiopathology of Inflammatory Bone Diseases, EA 4490, University Lille North of France, Quai Masset, Bassin Napoleon, BP120, 62327 Boulogne sur Mer (France); Department of Rheumatology, Lille University Hospital, Roger Salengro Hospital, 59037 Lille cedex (France); Service of Bone Diseases, Department of Internal Medicine Specialties, University Hospital of Geneva, CH-1211 Geneva 14 (Switzerland); Soubrier, Anne-Sophie [Physiopathology of Inflammatory Bone Diseases, EA 4490, University Lille North of France, Quai Masset, Bassin Napoleon, BP120, 62327 Boulogne sur Mer (France); Department of Rheumatology, Lille University Hospital, Roger Salengro Hospital, 59037 Lille cedex (France); Thouverey, Cyril [Service of Bone Diseases, Department of Internal Medicine Specialties, University Hospital of Geneva, CH-1211 Geneva 14 (Switzerland); Cortet, Bernard [Physiopathology of Inflammatory Bone Diseases, EA 4490, University Lille North of France, Quai Masset, Bassin Napoleon, BP120, 62327 Boulogne sur Mer (France); Department of Rheumatology, Lille University Hospital, Roger Salengro Hospital, 59037 Lille cedex (France); Broux, Odile [Physiopathology of Inflammatory Bone Diseases, EA 4490, University Lille North of France, Quai Masset, Bassin Napoleon, BP120, 62327 Boulogne sur Mer (France); Caverzasio, Joseph [Service of Bone Diseases, Department of Internal Medicine Specialties, University Hospital of Geneva, CH-1211 Geneva 14 (Switzerland); Hardouin, Pierre [Physiopathology of Inflammatory Bone Diseases, EA 4490, University Lille North of France, Quai Masset, Bassin Napoleon, BP120, 62327 Boulogne sur Mer (France)

    2012-11-02

    Highlights: Black-Right-Pointing-Pointer FGF modulates BMPs pathway in HMSCs by down-regulating BMP/BMPR expression. Black-Right-Pointing-Pointer This effect is mediated by ERK and JNK MAPKs pathways. Black-Right-Pointing-Pointer Crosstalk between FGF and BMPs must be taken into account in skeletal bioengineering. Black-Right-Pointing-Pointer It must also be considered in the use of recombinant BMPs in orthopedic and spine surgeries. -- Abstract: Understanding the interactions between growth factors and bone morphogenic proteins (BMPs) signaling remains a crucial issue to optimize the use of human mesenchymal stem cells (HMSCs) and BMPs in therapeutic perspectives and bone tissue engineering. BMPs are potent inducers of osteoblastic differentiation. They exert their actions via BMP receptors (BMPR), including BMPR1A, BMPR1B and BMPR2. Fibroblast growth factor 2 (FGF2) is expressed by cells of the osteoblastic lineage, increases their proliferation and is secreted during the healing process of fractures or in surgery bone sites. We hypothesized that FGF2 might influence HMSC osteoblastic differentiation by modulating expressions of BMPs and their receptors. BMP2, BMP4, BMPR1A and mainly BMPR1B expressions were up-regulated during this differentiation. FGF2 inhibited HMSCs osteoblastic differentiation and the up-regulation of BMPs and BMPR. This effect was prevented by inhibiting the ERK or JNK mitogen-activated protein kinases which are known to be activated by FGF2. These data provide a mechanism explaining the inhibitory effect of FGF2 on osteoblastic differentiation of HMSCs. These crosstalks between growth and osteogenic factors should be considered in the use of recombinant BMPs in therapeutic purpose of fracture repair or skeletal bioengineering.

  15. Metformin inhibits the proliferation of human prostate cancer PC-3 cells via the downregulation of insulin-like growth factor 1 receptor

    Energy Technology Data Exchange (ETDEWEB)

    Kato, Haruo, E-mail: hal.kato@gunma-u.ac.jp; Sekine, Yoshitaka; Furuya, Yosuke; Miyazawa, Yoshiyuki; Koike, Hidekazu; Suzuki, Kazuhiro

    2015-05-22

    Metformin is a biguanide drug that is widely used for the treatment of type 2 diabetes. Recent studies have shown that metformin inhibits cancer cell proliferation and tumor growth both in vitro and in vivo. The anti-tumor mechanisms of metformin include activation of the AMP-activated protein kinase/mTOR pathway and direct inhibition of insulin/insulin-like growth factor (IGF)-mediated cellular proliferation. However, the anti-tumor mechanism in prostate cancer remains unclear. Because activation of the IGF-1 receptor (IGF-1R) is required for prostate cell proliferation, IGF-1R inhibitors may be of therapeutic value. Accordingly, we examined the effects of metformin on IGF-1R signaling in prostate cancer cells. Metformin significantly inhibited PC-3 cell proliferation, migration, and invasion. IGF-1R mRNA expression decreased significantly after 48 h of treatment, and IGF-1R protein expression decreased in a similar manner. IGF-1R knockdown by siRNA transfection led to inhibited proliferation, migration and invasion of PC-3 cells. IGF-1 activated both ERK1/2 and Akt, but these effects were attenuated by metformin treatment. In addition, intraperitoneal treatment with metformin significantly reduced tumor growth and IGF-1R mRNA expression in PC-3 xenografts. Our results suggest that metformin is a potent inhibitor of the IGF-1/IGF-1R system and may be beneficial in prostate cancer treatment. - Highlights: • Metformin inhibited PC-3 cell proliferation, migration, and invasion. • Metformin decreased IGF-1R mRNA and protein expressions in PC-3 cells. • Metformin inhibited IGF-1 induced ERK and Akt phosphorylations in PC-3 cells. • Metformin treatment inhibited PC-3 cell growth and IGF-1R expression in vivo. • Metformin may be a potent inhibitor of the IGF-1/IGF-1R signaling.

  16. Impaired degradation followed by enhanced recycling of epidermal growth factor receptor caused by hypo-phosphorylation of tyrosine 1045 in RBE cells

    International Nuclear Information System (INIS)

    Since cholangiocarcinoma has a poor prognosis, several epidermal growth factor receptor (EGFR)-targeted therapies with antibody or small molecule inhibitor treatment have been proposed. However, their effect remains limited. The present study sought to understand the molecular genetic characteristics of cholangiocarcinoma related to EGFR, with emphasis on its degradation and recycling. We evaluated EGFR expression and colocalization by immunoblotting and immunofluorescence, cell surface EGFR expression by fluorescence-activated cell sorting (FACS), and EGFR ubiquitination and protein binding by immunoprecipitation in the human cholangiocarcinoma RBE and immortalized cholangiocyte MMNK-1 cell lines. Monensin treatment and Rab11a depletion by siRNA were adopted for inhibition of EGFR recycling. Upon stimulation with EGF, ligand-induced EGFR degradation was impaired and the expression of phospho-tyrosine 1068 and phospho-p44/42 MAPK was sustained in RBE cells as compared with MMNK-1 cells. In RBE cells, the process of EGFR sorting for lysosomal degradation was blocked at the early endosome stage, and non-degradated EGFR was recycled to the cell surface. A disrupted association between EGFR and the E3 ubiquitin ligase c-Cbl, as well as hypo-phosphorylation of EGFR at tyrosine 1045 (Tyr1045), were also observed in RBE cells. In RBE cells, up-regulation of EGFR Tyr1045 phosphorylation is a potentially useful molecular alteration in EGFR-targeted therapy. The combination of molecular-targeted therapy determined by the characteristics of individual EGFR phosphorylation events and EGFR recycling inhibition show promise in future treatments of cholangiocarcinoma

  17. Metformin inhibits the proliferation of human prostate cancer PC-3 cells via the downregulation of insulin-like growth factor 1 receptor

    International Nuclear Information System (INIS)

    Metformin is a biguanide drug that is widely used for the treatment of type 2 diabetes. Recent studies have shown that metformin inhibits cancer cell proliferation and tumor growth both in vitro and in vivo. The anti-tumor mechanisms of metformin include activation of the AMP-activated protein kinase/mTOR pathway and direct inhibition of insulin/insulin-like growth factor (IGF)-mediated cellular proliferation. However, the anti-tumor mechanism in prostate cancer remains unclear. Because activation of the IGF-1 receptor (IGF-1R) is required for prostate cell proliferation, IGF-1R inhibitors may be of therapeutic value. Accordingly, we examined the effects of metformin on IGF-1R signaling in prostate cancer cells. Metformin significantly inhibited PC-3 cell proliferation, migration, and invasion. IGF-1R mRNA expression decreased significantly after 48 h of treatment, and IGF-1R protein expression decreased in a similar manner. IGF-1R knockdown by siRNA transfection led to inhibited proliferation, migration and invasion of PC-3 cells. IGF-1 activated both ERK1/2 and Akt, but these effects were attenuated by metformin treatment. In addition, intraperitoneal treatment with metformin significantly reduced tumor growth and IGF-1R mRNA expression in PC-3 xenografts. Our results suggest that metformin is a potent inhibitor of the IGF-1/IGF-1R system and may be beneficial in prostate cancer treatment. - Highlights: • Metformin inhibited PC-3 cell proliferation, migration, and invasion. • Metformin decreased IGF-1R mRNA and protein expressions in PC-3 cells. • Metformin inhibited IGF-1 induced ERK and Akt phosphorylations in PC-3 cells. • Metformin treatment inhibited PC-3 cell growth and IGF-1R expression in vivo. • Metformin may be a potent inhibitor of the IGF-1/IGF-1R signaling

  18. Toll-like receptor 3 regulates angiogenesis and apoptosis in prostate cancer cell lines through hypoxia-inducible factor 1 alpha.

    Science.gov (United States)

    Paone, Alessio; Galli, Roberta; Gabellini, Chiara; Lukashev, Dmitriy; Starace, Donatella; Gorlach, Agnes; De Cesaris, Paola; Ziparo, Elio; Del Bufalo, Donatella; Sitkovsky, Michail V; Filippini, Antonio; Riccioli, Anna

    2010-07-01

    Toll-like receptors (TLRs) recognize microbial/viral-derived components that trigger innate immune response and conflicting data implicate TLR agonists in cancer, either as protumor or antitumor agents. We previously demonstrated that TLR3 activation mediated by its agonist poly(I:C) induces antitumor signaling, leading to apoptosis of prostate cancer cells LNCaP and PC3 with much more efficiency in the former than in the second more aggressive line. The transcription factor hypoxia-inducible factor 1 (HIF-1) regulates several cellular processes, including apoptosis, in response to hypoxia and to other stimuli also in normoxic conditions. Here we describe a novel protumor machinery triggered by TLR3 activation in PC3 cells consisting of increased expression of the specific I.3 isoform of HIF-1 alpha and nuclear accumulation of HIF-1 complex in normoxia, resulting in reduced apoptosis and in secretion of functional vascular endothelial growth factor (VEGF). Moreover, we report that, in the less aggressive LNCaP cells, TLR3 activation fails to induce nuclear accumulation of HIF-1 alpha. However, the transfection of I.3 isoform of hif-1 alpha in LNCaP cells allows poly(I:C)-induced HIF-1 activation, resulting in apoptosis protection and VEGF secretion. Altogether, our findings demonstrate that differences in the basal level of HIF-1 alpha expression in different prostate cancer cell lines underlie their differential response to TLR3 activation, suggesting a correlation between different stages of malignancy, hypoxic gene expression, and beneficial responsiveness to TLR agonists. PMID:20651983

  19. Toll-like Receptor 3 Regulates Angiogenesis and Apoptosis in Prostate Cancer Cell Lines through Hypoxia-Inducible Factor 1α1

    Science.gov (United States)

    Paone, Alessio; Galli, Roberta; Gabellini, Chiara; Lukashev, Dmitriy; Starace, Donatella; Gorlach, Agnes; De Cesaris, Paola; Ziparo, Elio; Del Bufalo, Donatella; Sitkovsky, Michail V; Filippini, Antonio; Riccioli, Anna

    2010-01-01

    Toll-like receptors (TLRs) recognize microbial/viral-derived components that trigger innate immune response and conflicting data implicate TLR agonists in cancer, either as protumor or antitumor agents. We previously demonstrated that TLR3 activation mediated by its agonist poly(I:C) induces antitumor signaling, leading to apoptosis of prostate cancer cells LNCaP and PC3 with much more efficiency in the former than in the second more aggressive line. The transcription factor hypoxia-inducible factor 1 (HIF-1) regulates several cellular processes, including apoptosis, in response to hypoxia and to other stimuli also in normoxic conditions. Here we describe a novel protumor machinery triggered by TLR3 activation in PC3 cells consisting of increased expression of the specific I.3 isoform of HIF-1α and nuclear accumulation of HIF-1 complex in normoxia, resulting in reduced apoptosis and in secretion of functional vascular endothelial growth factor (VEGF). Moreover, we report that, in the less aggressive LNCaP cells, TLR3 activation fails to induce nuclear accumulation of HIF-1α. However, the transfection of I.3 isoform of hif-1α in LNCaP cells allows poly(I:C)-induced HIF-1 activation, resulting in apoptosis protection and VEGF secretion. Altogether, our findings demonstrate that differences in the basal level of HIF-1α expression in different prostate cancer cell lines underlie their differential response to TLR3 activation, suggesting a correlation between different stages of malignancy, hypoxic gene expression, and beneficial responsiveness to TLR agonists. PMID:20651983

  20. Nuclear receptor co-regulator Kruppel-like factor 9 and prohibitin 2 expression in estrogen-induced epithelial cell proliferation in the mouse uterus

    Science.gov (United States)

    Estrogen, acting through its cognate receptor estrogen receptor-' (ESR1), is a critical regulator of uterine endometrial epithelial proliferation. Although the dynamic communication between endometrial stromal (ST) and epithelial cells is considered to be an important component in this process, key ...

  1. Interleukin 1β, tumor necrosis factor-α and interleukin 6 decreas nuclear thyroid hormone receptor capacity in a liver cell line

    International Nuclear Information System (INIS)

    Many of the acute inflammatory responses in critical illness are mediated by tumor necrosis factor-α (TNTF-α), interleukin 1β (IL-1β) and interleukin 6 (IL-6). Furthermore, these cytokines are involved in mediating the characteristic changes of thyroid function during acute disease known as non-thyroidal illness. In the present studies the authors investigated in vitro whether TNF-α, IL-1β and IL-6 modify nuclear thyroid hormone receptor (TR) capacity and/or affinity. Regulation of TR synthesis was studied in the human hepatoma cell line Hep-G2. Subconfluent cells were incubated with recombinant cytokines in serum-free medium. Nuclear extracts were prepared by high-salt extraction of cell nuclei. Binding assays were performed with [125I]-triiodothyronine; bound and free hormone were separated by filtration. Interleukin 1β decreased TR capacity in a dose-dependent manner. Compared with unstimulated cells, the TR capacity was reduced to 87.9 ± 3.9% after incubation with 0.1, 1.0 and 100 μg/l IL-1β, respectively. Interleukin 6 and TNF-α significantly reduced receptor capacity only at concentrations of 10μg/l or higher and the magnitude of the reduction was lower than with IL-1β. The TR capacity was reduced to 81.2 ± 2.3% and 83.2 ± 6.6% after stimulation with 10μg/l IL-6 or TNF-α, respectively. TR affinity was not altered significantly after stimulation with any of the cytokines. 44 refs., 4 figs

  2. Decreased expression of the mannose 6- phosphate/insulin-like growth factor-II receptor promotes growth of human breast cancer cells

    Directory of Open Access Journals (Sweden)

    Landman Natalie

    2002-07-01

    Full Text Available Abstract Background Loss or mutation of the mannose 6-phosphate/insulin-like growth factor-II receptor (M6P/IGF2R has been found in breast cancer. However, whether or not decreased levels of functional M6P/IGF2R directly contribute to the process of carcinogenesis needs to be further verified by functional studies. Methods In this study, using viral and ribozyme strategies we reduced the expression of M6P/IGF2R in human breast cancer cells and then examined the effect on growth and apoptosis of these cells. Results Our results showed that infection of MCF-7 cells with the adenovirus carrying a ribozyme targeted against the M6P/IGF2R mRNA dramatically reduced the level of transcripts and the functional activity of M6P/IGF2R in these cells. Accordingly, cells treated with the ribozyme exhibited a higher growth rate and a lower apoptotic index than control cells (infected with a control vector. Furthermore, decreased expression of M6P/IGF2R enhanced IGF-II-induced proliferation and reduced cell susceptibility to TNF-induced apoptosis. Conclusions These results suggest that M6P/IGF2R functions as a growth suppressor and its loss or mutation may contribute to development and progression of cancer. This study also demonstrates that adenoviral delivery of the ribozyme provides a useful tool for investigating the role of M6P/IGF2R in regulation of cell growth.

  3. Mutations of the KIT (Mast/Stem cell growth factor receptor) proto-oncogene account for a continuous range of phenotypes in human piebaldism

    Energy Technology Data Exchange (ETDEWEB)

    Spritz, R.A.; Holmes, S.A. (Univ. of Wisconsin, Madison, WI (United States)); Ramesar, R.; Greenberg, J.; Beighton, P.; Curtis, D.

    1992-11-01

    Piebaldism is a rare autosomal dominant disorder of pigmentation, characterized by congenital patches of white skin and hair from which melanocytes are absent. The authors have previously shown that piebaldism can result from missense and frameshift mutations of the KIT proto-oncogene, which encodes the cellular receptor tyrosine kinase for the mast/stem cell growth factor. Here, the authors report two novel KIT mutations associated with human piebaldism. A proximal frameshift is associated with a mild piebald phenotype, and a splice-junction mutation is associated with a highly variable piebald phenotype. They discuss the apparent relationship between the predicted impact of specific KIT mutations on total KIT-dependent signal transduction and the severity of the resultant piebald phenotypes. 35 refs., 5 figs.

  4. Development of epidermal growth factor receptor tyrosine kinase inhibitors against EGFR T790M. Mutation in non small-cell lung carcinoma

    Directory of Open Access Journals (Sweden)

    Wang Yuli

    2016-01-01

    Full Text Available Individualized therapies targeting epidermal growth factor receptor (EGFR mutations show promises for the treatment of non small-cell lung carcinoma (NSCLC. However, disease progression almost invariably occurs 1 year after tyrosine kinase inhibitor (TKI treatment. The most prominent mechanism of acquired resistance involves the secondary EGFR mutation, namely EGFR T790M, which accounts for 50%–60% of resistant tumors. A large amount of studies have focused on the development of effective strategies to treat TKI-resistant EGFR T790M mutation in lung tumors. Novel generations of EGFR inhibitors are producing encouraging results in patients with acquired resistance against EGFR T790M mutation. This review will summarize the novel inhibitors, which might overcome resistance against EGFR T790M mutation.

  5. Epidermal growth factor receptor targeted molecularly therapies of cancers

    International Nuclear Information System (INIS)

    Epidermal growth factor receptor (EGFR) has been known to be a significant factor in the development and growth of many types of cancers. It is now accepted that the EGFR signal transduction net work plays an important role in multiple tumorigenic processes, contributing to cancer cell proliferation, angiogenesis, and metastasis, as well as protection from apoptosis. Recently, EGFR monoclonal antibodies (McAb) and epidermal growth factor receptor-tyrosine kinase (EGFR-TK) inhibitors have been validated as new treatment approach for those EGFR-positive cancers and have shown activity aginst advanced, chemofractory cancers in clinical trials. This article focuses on three EGFR targeted molecularly therapies of cancers. (authors)

  6. T cell factor-1 controls the lifetime of CD4+ CD8+ thymocytes in vivo and distal T cell receptor α-chain rearrangement required for NKT cell development.

    Directory of Open Access Journals (Sweden)

    Archna Sharma

    Full Text Available Natural killer T (NKT cells are a component of innate and adaptive immune systems implicated in immune, autoimmune responses and in the control of obesity and cancer. NKT cells develop from common CD4+ CD8+ double positive (DP thymocyte precursors after the rearrangement and expression of T cell receptor (TCR Vα14-Jα18 gene. Temporal regulation and late appearance of Vα14-Jα18 rearrangement in immature DP thymocytes has been demonstrated. However, the precise control of lifetime of DP thymocytes in vivo that enables distal rearrangements remains incompletely defined. Here we demonstrate that T cell factor (TCF-1, encoded by the Tcf7 gene, is critical for the extended lifetime of DP thymocytes. TCF-1-deficient DP thymocytes fail to undergo TCR Vα14-Jα18 rearrangement and produce significantly fewer NKT cells. Ectopic expression of Bcl-xL permits Vα14-Jα18 rearrangement and rescues NKT cell development. We report that TCF-1 regulates expression of RORγt, which regulates DP thymocyte survival by controlling expression of Bcl-xL. We posit that TCF-1 along with its cofactors controls the lifetime of DP thymocytes in vivo.

  7. GSK1838705A, an insulin-like growth factor-1 receptor/insulin receptor inhibitor, induces apoptosis and reduces viability of docetaxel-resistant prostate cancer cells both in vitro and in vivo

    Directory of Open Access Journals (Sweden)

    Zhou F

    2015-04-01

    Full Text Available Fayou Zhou,1,2 Xianguo Chen,1 Song Fan,1 Sheng Tai,1 Changqin Jiang,1 Yifei Zhang,1 Zongyao Hao,1 Jun Zhou,1 Haoqiang Shi,1 Li Zhang,1 Chaozhao Liang1 1Department of Urology, First Affiliated Hospital of Anhui Medical University, Hefei, 2Department of Urology, Traditional Chinese Medical Hospital of Wuhu City, WuHu, People’s Republic of China Abstract: Prostate cancer is the leading malignancy and the second most common cause of cancer-related death in men. Despite high cure rates with surgery and/or radiation, 30%–40% of patients eventually develop advanced cancer. Docetaxel is one of the most effective and well established chemotherapeutic agents for prostate cancer. However, docetaxel resistance often develops within months. Combination therapies have been proposed to improve the therapeutic efficacy of docetaxel in prostate cancer, and there is an urgent need to identify agents that are effective for treatment of the disease, especially docetaxel-resistant prostate cancer. In this work, we investigated the activity of GSK1838705A, a potent insulin-like growth factor-1 receptor (IGF1R/insulin receptor (IR inhibitor, in prostate cancer, especially docetaxel-resistant prostate cancer. We found that GSK1838705A could effectively reduce the viability of both docetaxel-sensitive and docetaxel-resistant prostate cancer cells. GSK1838705A induced marked apoptosis in docetaxel-resistant cells, and also dramatically inhibited migration of these cells. Further, GSK1838705A significantly inhibited phosphorylation of IGF1R/IR. Importantly, GSK1838705A significantly suppressed docetaxel-resistant PC-3R tumor growth in vivo. This is the first study of GSK1838705A in prostate cancer. Our results indicate that GSK1838705A is a promising compound for the treatment of prostate cancer, especially for those who develop resistance to docetaxel, and might shed new light on treatment for prostate cancer. Keywords: prostate cancer, GSK1838705A, insulin

  8. Gefitinib, an epidermal growth factor receptor blockade agent, shows additional or synergistic effects on the radiosensitivity of esophageal cancer cells in vitro

    International Nuclear Information System (INIS)

    Human esophageal cancers have been shown to express high levels of epidermal growth factor receptor (EGFR) and a relationship between high EGFR expression and local advance, the number of lymph node metastases, life expectancy, and sensitivity to chemo-radiotherapy has been demonstrated. We examined the use of gefitinib, an orally active EGER-selective tyrosine kinase inhibitor, as a new strategy for treatment of esophageal carcinoma. The effects of gefitinib were evaluated in monotherapy and in combination with radiotherapy in human esophageal carcinoma cell lines. Gefitinib produced a dose-dependent inhibition of cellular proliferation in all of the 8 esophageal carcinoma cell lines examined, with IC50 values ranging from 5.7 μM to 36.9 μM. In combination, gefitinib and radiotherapy showed a synergistic effect in 2 human esophageal carcinoma cell lines and an additive effect in 5 cell lines. Western blotting demonstrated that gefitinib blocked activation of the EGFR-extracellular signal-regulated kinase (Erk) pathway and the EGFR-phosphoinositide-3 kinase (PI3K)-Akt pathway after irradiation. These results suggest that further evaluation of EGFR blockade as a treatment for esophageal cancer should be performed, and that radiotherapy combined with EGFR blockade may enhance the response of esophageal carcinoma to therapy. (author)

  9. Toll-like Receptor 3 Regulates Angiogenesis and Apoptosis in Prostate Cancer Cell Lines through Hypoxia-Inducible Factor

    Directory of Open Access Journals (Sweden)

    Alessio Paone

    2010-07-01

    Full Text Available Toll-like receptors (TLRs recognize microbial/viral-derived components that trigger innate immune response and conflicting data implicate TLR agonists in cancer, either as protumor or antitumor agents. We previously demonstrated that TLR3 activation mediated by its agonist poly(I:C induces antitumor signaling, leading to apoptosis of prostate cancer cells LNCaP and PC3 with much more efficiency in the former than in the second more aggressive line. The transcription factor hypoxia-induciblefactor 1 (HIF-1regulates several cellular processes, includingapoptosis, in response to hypoxia and to other stimuli also in normoxic conditions. Here we describe a novel protumor machinery triggered by TLR3 activation in PC3 cells consisting of increased expression of the specific 1.3 isoform of HIF-1α and nuclear accumulation of HIF-1 complex in normoxia, resulting in reduced apoptosis and in secretion of functional vascular endothelial growth factor (VEGF. Moreover, we report that, in the less aggressive LNCaP cells, TLR3 activation fails to induce nuclear accumulation of HIF-1α. However, the transfection of 1.3 isoform of hif-1α in LNCaP cells allows poly(I:CI-induced HIF-1 activation, resulting in apoptosis protection and VEGF secretion. Altogether, our findings demonstrate that differences in the basal level of HIF-1α expression in different prostate cancer cell lines underlie their differential response to TLR3 activation, suggesting a correlation between different stages of malignancy, hypoxic gene expression, and beneficial responsiveness to TLR agonists.

  10. Effects of epidermal growth factor receptor and phosphatase and tensin homologue gene expression on the inhibition of U87MG glioblastoma cell proliferation induced by protein kinase inhibitors.

    Science.gov (United States)

    Xing, Wen-Jing; Zou, Yan; Han, Qing-Lian; Dong, Yu-Cui; Deng, Zhen-Ling; Lv, Xiao-Hong; Jiang, Tao; Ren, Huan

    2013-01-01

    The aim of the present study was to analyse the antiproliferative effects and mechanisms of action of protein kinase inhibitors (PKIs) in human glioblastoma multiforme (GBM) cells with different epidermal growth factor receptor (EGFR) and phosphatase and tensin homologue (PTEN) status. The GBM cell models were established by transfection of plasmids carrying wild-type EGFR, mutated EGFRvIII or PTEN and clonal selection in U87MG cells. Phosphatidylinositol 3-kinase (PI3-K)/AKT pathway-focused gene profiles were examined by real-time polymerase chain reaction-based assays, protein expression was evaluated by western blotting and the antiproliferative effects of PKI treatment were determined by the 3-(4,5-dimethyl-2 thiazoyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay in GBM cells. The cell model with intact PTEN and low EGFR levels was the most sensitive to treatment with the EGFR inhibitor erlotinib, whereas the model with EGFRvIII was the most resistant to treatment with the mitogen-activated protein kinase kinase inhibitor U0126. The dual PI3-K and mammalian target of rapamycin (mTOR) inhibitor PI103 had the most potent antiproliferative effects against all GBM cells tested. Following simultaneous stimulation of AKT and extracellular signal-regulated kinase, rapamycin concentrations > 0.5 nmol/L failed to exhibit a further growth inhibitory effect. Concurrent inhibition of mTOR and ribosomal protein s6 activity may underlie the inhibition of GBM proliferation by PKI. In conclusion, overexpression of EGFR or EGFRvIII, accompanied by a loss of PTEN, contributed to the activation of multiple intracellular signalling pathways in GBM cells. Rigorous examination of biomarkers in tumour tissues before and after treatment may be necessary to determine the efficacy of PKI therapy in patients with GBM. PMID:23110505

  11. Astrocyte Mitogen Inhibitor Related to Epidermal Growth Factor Receptor

    Science.gov (United States)

    Nieto-Sampedro, Manuel

    1988-06-01

    Epidermal growth factor (EGF) is a well-characterized polypeptide hormone with diverse biological activities, including stimulation of astrocyte division. A soluble astrocyte mitogen inhibitor, immunologically related to the EGF receptor, is present in rat brain. Injury to the brain causes a time-dependent reduction in the levels of this inhibitor and the concomitant appearance of EGF receptor on the astrocyte surface. Intracerebral injection of antibody capable of binding the inhibitor caused the appearance of numerous reactive astrocytes. EGF receptor-related inhibitors may play a key role in the control of glial cell division in both normal and injured brain.

  12. Relationship between serum carcinoembryonic antigen level and epidermal growth factor receptor mutations with the influence on the prognosis of non-small-cell lung cancer patients

    Directory of Open Access Journals (Sweden)

    Cai ZX

    2016-06-01

    Full Text Available Zuxun Cai Department of Thoracic Surgery, Henan Provincial Chest Hospital, Zhengzhou City, People’s Republic of China Objective: To investigate the relationship between serum carcinoembryonic antigen (CEA level and epidermal growth factor receptor (EGFR gene mutations in non-small-cell lung cancer (NSCLC patients and to analyze the influence of CEA level on postoperative survival time in lung cancer patients. Methods: A total of 296 patients who were treated in Thoracic Surgery Department of Henan Provincial Chest Hospital from September 2011 to September 2013 were recruited. The level of tumor markers, such as CEA, was determined before the surgery, and EGFR gene mutations were detected after surgery. Thereby, the relationship between tumor makers, including CEA, and EGFR mutation and its influence on prognosis could be investigated. Results: Among 296 patients, the positive rate of EGFR gene mutation was 37.84% (112/296; the mutation occurred more frequently in nonsmokers, adenocarcinoma patients, women, and patients aged <60 years (P<0.05. Both tumor markers and chemosensitivity indicators were related to the profile of EGFR mutations. Elevated squamous cell carcinoma and Cyfra21-1 as well as positively expressed ERCC1 were more common in patients with wild-type EGFR (P<0.05, whereas increased CEA level was observed more frequently in patients with EGFR gene mutation (P=0.012. The positive rate of EGFR gene mutations was higher as the serum CEA level increased, that is, the positive rate in patients with serum CEA level <5, 5–20, and >20 µg/L was 39.81%, 45.32%, and 65.47%, respectively (P=0.004. Logistic regression analysis showed that CEA level was an independent factor in predicting EGFR gene mutations, and serum CEA level was also an independent factor in affecting the prognosis of NSCLC patients, as the overall 2-year survival rate was 73.86% in elevated CEA group and 86.43% in normal group (P<0.01. Conclusion: The prognosis of

  13. The structural insights of stem cell factor receptor (c-Kit interaction with tyrosine phosphatase-2 (Shp-2: An in silico analysis

    Directory of Open Access Journals (Sweden)

    Gurudutta Gangenahalli U

    2010-01-01

    Full Text Available Abstract Background Stem cell factor (SCF receptor c-Kit is recognized as a key signaling molecule, which transduces signals for the proliferation, differentiation and survival of stem cells. Binding of SCF to its receptor triggers transactivation, leading to the recruitment of kinases and phosphatases to the docking platforms of c-Kit catalytic domain. Tyrosine phosphatase-1 (Shp-1 deactivates/attenuates 'Kit' kinase activity. Whereas, Asp816Val mutation in the Kit activation loop transforms kinase domain to a constitutively activated state (switch off-to-on state, in a ligand-independent manner. This phenomenon completely abrogates negative regulation of Shp-1. To predict the possible molecular basis of interaction between c-Kit and Shp-1, we have performed an in silico protein-protein docking study between crystal structure of activated c-Kit (phosphorylated c-Kit and full length crystal structure of Shp-2, a close structural counterpart of Shp-1. Findings Study revealed a stretch of conserved amino acids (Lys818 to Ser821 in the Kit activation domain, which makes decisive H-bonds with N-sh2 and phosphotyrosine binding pocket residues of the phosphatase. These H-bonds may impose an inhibitory steric hindrance to the catalytic domain of c-Kit, there by blocking further interaction of the activation loop molecules with incoming kinases. We have also predicted a phosphotyrosine binding pocket in SH2 domains of Shp-1, which is found to be predominantly closer to a catalytic groove like structure in c-Kit kinase domain. Conclusions This study predicts that crucial hydrogen bonding between N-sh2 domain of Shp-1 and Kit activation loop can modulate the negative regulation of c-Kit kinase by Shp-1. Thus, this finding is expected to play a significant role in designing suitable gain-of-function c-Kit mutants for inducing conditional proliferation of hematopoietic stem cells.

  14. Pregnane and Xenobiotic Receptor gene expression in liver cells is modulated by Ets-1 in synchrony with transcription factors Pax5, LEF-1 and c-jun

    Energy Technology Data Exchange (ETDEWEB)

    Kumari, Sangeeta; Saradhi, Mallampati; Rana, Manjul; Chatterjee, Swagata [Special Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi 110067 (India); Aumercier, Marc [IRI, CNRS USR 3078, Université de Lille-Nord de France, Parc CNRS de la Haute Borne, 50 Avenue de Halley, BP 70478, 59658 Villeneuve d’Ascq Cedex (France); Mukhopadhyay, Gauranga [Special Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi 110067 (India); Tyagi, Rakesh K., E-mail: rktyagi@yahoo.com [Special Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi 110067 (India)

    2015-01-15

    Nuclear receptor PXR is predominantly expressed in liver and intestine. Expression of PXR is observed to be dysregulated in various metabolic disorders indicating its involvement in disease development. However, information available on mechanisms of PXR self-regulation is fragmentary. The present investigation identifies some of the regulatory elements responsible for its tight regulation and low cellular expression. Here, we report that the PXR-promoter is a target for some key transcription factors like PU.1/Ets-1, Pax5, LEF-1 and c-Jun. Interestingly, we observed that PXR-promoter responsiveness to Pax5, LEF-1 and c-Jun, is considerably enhanced by Ets transcription factors (PU.1 and Ets-1). Co-transfection of cells with Ets-1, LEF-1 and c-Jun increased PXR-promoter activity by 5-fold and also induced expression of endogenous human PXR. Site-directed mutagenesis and transfection studies revealed that two Ets binding sites and two of the three LEF binding sites in the PXR-promoter are functional and have a positive effect on PXR transcription. Results suggest that expression of Ets family members, in conjunction with Pax5, LEF-1 and c-Jun, lead to coordinated up-regulation of PXR gene transcription. Insights obtained on the regulation of PXR gene have relevance in offering important cues towards normal functioning as well as development of several metabolic disorders via PXR signaling. - Highlights: • The study identified cis-regulatory elements in the nuclear receptor PXR promoter. • Several trans-acting factors modulating the PXR-promoter have been identified. • PU.1/Ets-1, Pax5, LEF-1, c-Jun, LyF-VI and NF-1 act as modulators of the PXR-promoter. • Ets-1 in conjunction with LEF-1 and c-Jun exhibit 5-fold activation of the PXR-promoter. • Insights into PXR-regulation have relevance in normal and pathological conditions.

  15. Pregnane and Xenobiotic Receptor gene expression in liver cells is modulated by Ets-1 in synchrony with transcription factors Pax5, LEF-1 and c-jun

    International Nuclear Information System (INIS)

    Nuclear receptor PXR is predominantly expressed in liver and intestine. Expression of PXR is observed to be dysregulated in various metabolic disorders indicating its involvement in disease development. However, information available on mechanisms of PXR self-regulation is fragmentary. The present investigation identifies some of the regulatory elements responsible for its tight regulation and low cellular expression. Here, we report that the PXR-promoter is a target for some key transcription factors like PU.1/Ets-1, Pax5, LEF-1 and c-Jun. Interestingly, we observed that PXR-promoter responsiveness to Pax5, LEF-1 and c-Jun, is considerably enhanced by Ets transcription factors (PU.1 and Ets-1). Co-transfection of cells with Ets-1, LEF-1 and c-Jun increased PXR-promoter activity by 5-fold and also induced expression of endogenous human PXR. Site-directed mutagenesis and transfection studies revealed that two Ets binding sites and two of the three LEF binding sites in the PXR-promoter are functional and have a positive effect on PXR transcription. Results suggest that expression of Ets family members, in conjunction with Pax5, LEF-1 and c-Jun, lead to coordinated up-regulation of PXR gene transcription. Insights obtained on the regulation of PXR gene have relevance in offering important cues towards normal functioning as well as development of several metabolic disorders via PXR signaling. - Highlights: • The study identified cis-regulatory elements in the nuclear receptor PXR promoter. • Several trans-acting factors modulating the PXR-promoter have been identified. • PU.1/Ets-1, Pax5, LEF-1, c-Jun, LyF-VI and NF-1 act as modulators of the PXR-promoter. • Ets-1 in conjunction with LEF-1 and c-Jun exhibit 5-fold activation of the PXR-promoter. • Insights into PXR-regulation have relevance in normal and pathological conditions

  16. Stabilization of the bioactivity of tumor necrosis factor by its soluble receptors

    DEFF Research Database (Denmark)

    Aderka, D; Engelmann, H; Maor, Y; Brakebusch, C; Wallach, D

    1992-01-01

    The receptors for tumor necrosis factor (TNF) exist in cell-associated as well as soluble forms, both binding specifically to TNF. Since the soluble forms of TNF receptors (sTNF-Rs) can compete with the cell-associated TNF receptors for TNF, it was suggested that they function as inhibitors of TN...

  17. Oral epidermal growth factor receptor tyrosine kinase inhibitors for the treatment of non-small cell lung cancer: comparative pharmacokinetics and drug-drug interactions.

    Science.gov (United States)

    Peters, Solange; Zimmermann, Stefan; Adjei, Alex A

    2014-09-01

    The development of orally active small molecule inhibitors of the epidermal growth factor receptor (EGFR) has led to new treatment options for non-small cell lung cancer (NSCLC). Patients with activating mutations of the EGFR gene show sensitivity to, and clinical benefit from, treatment with EGFR tyrosine kinase inhibitors (EGFR-TKls). First generation reversible ATP-competitive EGFR-TKls, gefitinib and erlotinib, are effective as first, second-line or maintenance therapy. Despite initial benefit, most patients develop resistance within a year, 50-60% of cases being related to the appearance of a T790M gatekeeper mutation. Newer, irreversible EGFR-TKls - afatinib and dacomitinib - covalently bind to and inhibit multiple receptors in the ErbB family (EGFR, HER2 and HER4). These agents have been mainly evaluated for first-line treatment but also in the setting of acquired resistance to first-generation EGFR-TKls. Afatinib is the first ErbB family blocker approved for patients with NSCLC with activating EGFR mutations; dacomitinib is in late stage clinical development. Mutant-selective EGFR inhibitors (AZD9291, CO-1686, HM61713) that specifically target the T790M resistance mutation are in early development. The EGFR-TKIs differ in their spectrum of target kinases, reversibility of binding to EGFR receptor, pharmacokinetics and potential for drug-drug interactions, as discussed in this review. For the clinician, these differences are relevant in the setting of polymedicated patients with NSCLC, as well as from the perspective of innovative anticancer drug combination strategies. PMID:25027951

  18. Cloning of murine TCF-1, a T cell-specific transcription factor interacting with functional motifs in the CD3-epsilon and T cell receptor alpha enhancers

    OpenAIRE

    1991-01-01

    CD3-epsilon gene expression is confined to the T cell lineage. We have recently identified and cloned a human transcription factor, TCF-1, that binds to a functional element in the T lymphocyte-specific enhancer of CD3-epsilon. In a panel of human cell lines, TCF-1 expression was restricted to T lineage cells. TCF-1 belonged to a novel family of genes that contain the so-called high mobility group 1 (HMG) box. Here we report the cloning of murine TCF-1. Two splice alternatives were identified...

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

    International Nuclear Information System (INIS)

    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

  20. Activation of Cumulus Cell SMAD2/3 and Epidermal Growth Factor Receptor Pathways Are Involved in Porcine Oocyte-Cumulus Cell Expansion and Steroidogenesis

    Czech Academy of Sciences Publication Activity Database

    Nagyová, Eva; Camaioni, A.; Scsuková, S.; Mlynarčíková, A.; Procházka, Radek; Němcová, Lucie; Salustri, A.

    2011-01-01

    Roč. 78, č. 6 (2011), s. 391-402. ISSN 1040-452X R&D Projects: GA ČR GA523/08/0111 Institutional research plan: CEZ:AV0Z50450515 Keywords : MURAL GRANULOSA-CELLS * IN-VITRO MATURATION * PREOVULATORY OVARIAN -FOLLICLES Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.532, year: 2011

  1. Effect of arsenic trioxide on vascular endothelial cell proliferation and expression of vascular endothelial growth factor receptors Flt-1 and KDR in gastric cancer in nude mice

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    AIM: To investigate the effect of arsenic trioxide (As2O3) on expression of vascular endothelial growth factor receptor-1 (VEGFR-1, Flt-1) and VEGFR-2 (KDR) in human gastric tumor cells and proliferation of vascular endothelial cells.METHODS: The solid tumor model was formed in nude mice with the gastric cancer cell line SGC-7901. The animals were treated with As2O3. Microvessel density (MVD) and expression of Flt-1 and KDR were detected by immunofluorescence laser confocal microscopy.SGC-7901 cells were treated respectively by exogenous recombinant human VEGF165 or VEGF165 + As2O3. Cell viability was measured by MTT assay. Cell viability of ECV304 cells was measured by MTT assay, and cell cycle and apoptosis were analyzed using flow cytometry.RESULTS: The tumor growth inhibition was 30.33% and 50.85%, respectively, in mice treated with As2O3 2.5 and 5 mg/kg. MVD was significantly lower in arsenic-treated mice than in the control group. The fluorescence intensity levels of Flt-1 and KDR were significantly less in the arsenic-treated mice than in the control group. VEGF165 may accelerate growth of SGC7901 cells, but As2O3 may disturb the stimulating effect of VEGF165. ECV304 cell growth was suppressed by 76.51%, 71.09% and 61.49% after 48 h treatment with As2O3 at 0.5, 2.5 and 5 μmol/L, respectively. Early apoptosis in the As2O3-treated mice was 2.88-5.1 times higher than that in the controls, and late apoptosis was 1.17-1.67 times higher than that in the controls.CONCLUSION: Our results showed that As2O3 delays tumor growth, inhibits MVD, down-regulates Flt-1 and KDR expression, and disturbs the stimulating effect of VEGF165 on the growth of SGC7901 cells. These results suggest that As2O3 might delay growth of gastric tumors through inhibiting the paracrine and autocrine pathways of VEGF/VEGFRs.

  2. Luteolin decreases IGF-II production and downregulates insulin-like growth factor-I receptor signaling in HT-29 human colon cancer cells

    Directory of Open Access Journals (Sweden)

    Lim Do

    2012-01-01

    Full Text Available Abstract Background Luteolin is a 3',4',5,7-tetrahydroxyflavone found in various fruits and vegetables. We have shown previously that luteolin reduces HT-29 cell growth by inducing apoptosis and cell cycle arrest. The objective of this study was to examine whether luteolin downregulates the insulin-like growth factor-I receptor (IGF-IR signaling pathway in HT-29 cells. Methods In order to assess the effects of luteolin and/or IGF-I on the IGF-IR signaling pathway, cells were cultured with or without 60 μmol/L luteolin and/or 10 nmol/L IGF-I. Cell proliferation, DNA synthesis, and IGF-IR mRNA levels were evaluated by a cell viability assay, [3H]thymidine incorporation assays, and real-time polymerase chain reaction, respectively. Western blot analyses, immunoprecipitation, and in vitro kinase assays were conducted to evaluate the secretion of IGF-II, the protein expression and activation of IGF-IR, and the association of the p85 subunit of phophatidylinositol-3 kinase (PI3K with IGF-IR, the phosphorylation of Akt and extracellular signal-regulated kinase (ERK1/2, and cell division cycle 25c (CDC25c, and PI3K activity. Results Luteolin (0 - 60 μmol/L dose-dependently reduced the IGF-II secretion of HT-29 cells. IGF-I stimulated HT-29 cell growth but did not abrogate luteolin-induced growth inhibition. Luteolin reduced the levels of the IGF-IR precursor protein and IGF-IR transcripts. Luteolin reduced the IGF-I-induced tyrosine phosphorylation of IGF-IR and the association of p85 with IGF-IR. Additionally, luteolin inhibited the activity of PI3K activity as well as the phosphorylation of Akt, ERK1/2, and CDC25c in the presence and absence of IGF-I stimulation. Conclusions The present results demonstrate that luteolin downregulates the activation of the PI3K/Akt and ERK1/2 pathways via a reduction in IGF-IR signaling in HT-29 cells; this may be one of the mechanisms responsible for the observed luteolin-induced apoptosis and cell cycle arrest.

  3. Esculetin attenuates receptor activator of nuclear factor kappa-B ligand-mediated osteoclast differentiation through c-Fos/nuclear factor of activated T-cells c1 signaling pathway

    Energy Technology Data Exchange (ETDEWEB)

    Baek, Jong Min; Park, Sun-Hyang; Cheon, Yoon-Hee; Ahn, Sung-Jun [Department of Anatomy, School of Medicine, Wonkwang University, Iksan, Jeonbuk 570-749 (Korea, Republic of); Lee, Myeung Su [Division of Rheumatology, Department of Internal Medicine, Wonkwang University, Iksan, Jeonbuk 570-749 (Korea, Republic of); Imaging Science-based Lung and Bone Diseases Research Center, Wonkwang University, Iksan, Jeonbuk 570-749 (Korea, Republic of); Institute for Skeletal Disease, Wonkwang University, Iksan, Jeonbuk 570-749 (Korea, Republic of); Oh, Jaemin, E-mail: jmoh@wku.ac.kr [Department of Anatomy, School of Medicine, Wonkwang University, Iksan, Jeonbuk 570-749 (Korea, Republic of); Imaging Science-based Lung and Bone Diseases Research Center, Wonkwang University, Iksan, Jeonbuk 570-749 (Korea, Republic of); Institute for Skeletal Disease, Wonkwang University, Iksan, Jeonbuk 570-749 (Korea, Republic of); Kim, Ju-Young, E-mail: kimjy1014@gmail.com [Imaging Science-based Lung and Bone Diseases Research Center, Wonkwang University, Iksan, Jeonbuk 570-749 (Korea, Republic of)

    2015-05-29

    Esculetin exerts various biological effects on anti-oxidation, anti-tumors, and anti-inflammation. However, the involvement of esculetin in the bone metabolism process, particularly osteoclast differentiation has not yet been investigated. In the present study, we first confirmed the inhibitory effect of esculetin on receptor activator of nuclear factor-κB ligand (RANKL)-induced osteoclast formation. We then revealed the relationship between esculetin and the expression of osteoclast-specific molecules to elucidate its underlying mechanisms. Esculetin interfered with the expression of c-Fos and nuclear factor of activated T cell c1 (NFATc1) both at the mRNA and protein level with no involvement in osteoclast-associated early signaling pathways, suppressing the expression of various transcription factors exclusively expressed in osteoclasts such as tartrate-resistant acid phosphatase (Trap), osteoclast-associated receptor (Oscar), dendritic cell-specific transmembrane protein (Dcstamp), osteoclast stimulatory transmembrane protein (Ocstamp), cathepsin K, αvβ3 integrin, and calcitonin receptor (Ctr). Additionally, esculetin inhibited the formation of filamentous actin (F-actin) ring-positive osteoclasts during osteoclast differentiation. However, the development of F-actin structures and subsequent bone resorbing activity of mature osteoclasts, which are observed in osteoclast/osteoblast co-culture systems were not affected by esculetin. Taken together, our results indicate for the first time that esculetin inhibits RANKL-mediated osteoclastogenesis via direct suppression of c-Fos and NFATc1 expression and exerts an inhibitory effect on actin ring formation during osteoclastogenesis. - Highlights: • We first investigated the effects of esculetin on osteoclast differentiation and function. • Our data demonstrate for the first time that esculetin can suppress osteoclastogenesis in vitro. • Esculetin acts as an inhibitor of c-Fos and NFATc1 activation.

  4. Esculetin attenuates receptor activator of nuclear factor kappa-B ligand-mediated osteoclast differentiation through c-Fos/nuclear factor of activated T-cells c1 signaling pathway

    International Nuclear Information System (INIS)

    Esculetin exerts various biological effects on anti-oxidation, anti-tumors, and anti-inflammation. However, the involvement of esculetin in the bone metabolism process, particularly osteoclast differentiation has not yet been investigated. In the present study, we first confirmed the inhibitory effect of esculetin on receptor activator of nuclear factor-κB ligand (RANKL)-induced osteoclast formation. We then revealed the relationship between esculetin and the expression of osteoclast-specific molecules to elucidate its underlying mechanisms. Esculetin interfered with the expression of c-Fos and nuclear factor of activated T cell c1 (NFATc1) both at the mRNA and protein level with no involvement in osteoclast-associated early signaling pathways, suppressing the expression of various transcription factors exclusively expressed in osteoclasts such as tartrate-resistant acid phosphatase (Trap), osteoclast-associated receptor (Oscar), dendritic cell-specific transmembrane protein (Dcstamp), osteoclast stimulatory transmembrane protein (Ocstamp), cathepsin K, αvβ3 integrin, and calcitonin receptor (Ctr). Additionally, esculetin inhibited the formation of filamentous actin (F-actin) ring-positive osteoclasts during osteoclast differentiation. However, the development of F-actin structures and subsequent bone resorbing activity of mature osteoclasts, which are observed in osteoclast/osteoblast co-culture systems were not affected by esculetin. Taken together, our results indicate for the first time that esculetin inhibits RANKL-mediated osteoclastogenesis via direct suppression of c-Fos and NFATc1 expression and exerts an inhibitory effect on actin ring formation during osteoclastogenesis. - Highlights: • We first investigated the effects of esculetin on osteoclast differentiation and function. • Our data demonstrate for the first time that esculetin can suppress osteoclastogenesis in vitro. • Esculetin acts as an inhibitor of c-Fos and NFATc1 activation.

  5. EXPRESSION OF GROWTH-FACTORS AND GROWTH-FACTOR RECEPTORS IN NORMAL AND TUMOROUS HUMAN THYROID TISSUES

    NARCIS (Netherlands)

    van der Laan, B.F.A.M.; FREEMAN, JL; ASA, SL

    1995-01-01

    A number of growth factors have been implicated as stimuli of thyroid cell proliferation; overexpression of these growth factors and/or their receptors may play a role in the growth of thyroid tumors. To determine if immunohistochemical detection of growth factors and/or their receptors correlates w

  6. Molecular Mechanisms Underlying the Antitumor Activity of 3-Aminopropanamide Irreversible Inhibitors of the Epidermal Growth Factor Receptor in Non–Small Cell Lung Cancer

    Directory of Open Access Journals (Sweden)

    Elena Galvani

    2013-01-01

    Full Text Available Overcoming the emergence of acquired resistance to clinically approved epidermal growth factor receptor (EGFR inhibitors is a major challenge in the treatment of advanced non–small cell lung cancer (NSCLC. The aim of this study was to investigate the effects of a series of novel compounds affecting viability of NSCLC NCI-H1975 cells (carrying the EGFR T790M mutation. The inhibition of the autophosphorylation of EGFR occurred at nanomolar concentrations and both UPR1282 and UPR1268 caused a significant induction of apoptosis. Targeting of EGFR and downstream pathways was confirmed by a peptide substrate array, which highlighted the inhibition of other kinases involved in NSCLC cell aggressive behavior. Accordingly, the drugs inhibited migration (about 30% vs. control, which could be, in part, explained also by the increase of E-cadherin expression. Additionally, we observed a contraction of the volume of H1975 spheroids, associated with the reduction of the cancer stem–like cell hallmark CD133. The activity of UPR1282 was retained in H1975 xenograft models where it determined tumor shrinkage (P < .05 and resulted well tolerated compared to canertinib. Of note, the kinase activity profile of UPR1282 on xenograft tumor tissues showed overlapping results with respect to the activity in H1975 cells, unraveling the inhibition of kinases involved in pivotal proliferation and invasive signaling pathways. In conclusion, UPR1282 and UPR1268 are effective against various processes involved in malignancy transformation and progression and may be promising compounds for the future treatment of gefitinib-resistant NSCLCs.

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

    Directory of Open Access Journals (Sweden)

    Jennifer Lee

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

  8. Development of Nano-Liposomal Formulations of Epidermal Growth Factor Receptor Inhibitors and their Pharmacological Interactions on Drug-Sensitive and Drug-Resistant Cancer Cell Lines

    Science.gov (United States)

    Trummer, Brian J.

    A rapidly expanding understanding of molecular derangements in cancer cell function has led to the development of selective, targeted chemotherapeutic agents. Growth factor signal transduction networks are frequently activated in an aberrant fashion, particularly through the activity of receptor tyrosine kinases (RTK). This has spurred an intensive effort to develop receptor tyrosine kinase inhibitors (RTKI) that are targeted to specific receptors, or receptor subfamilies. Chapter 1 reviews the pharmacology, preclinical, and clinical aspects of RTKIs that target the epidermal growth factor receptor (EGFR). EGFR inhibitors demonstrate significant success at inhibiting phosphorylation-based signaling pathways that promote cancer cell proliferation. Additionally RTKIs have physicochemical and structural characteristics that enable them to function as inhibitors of multi-drug resistance transport proteins. Thus EGFR inhibitors and other RTKIs have both on-target and off-target activities that could be beneficial in cancer therapy. However, these agents exert a number of side effects, some of which arise from their hydrophobic nature and large in vivo volume of distribution. Side effects of the EGFR inhibitor gefitinib include skin rash, severe myelotoxicity when combined with certain chemotherapeutic agents, and impairment of the blood brain barrier to xenobiotics. Weighing the preclinical and clinical observations with the EGFR inhibitors, we developed the primary overall hypothesis of this research: that drug-carrier formulations of RTKIs such as the EGFR inhibitors could be developed based on nanoparticulate liposomal carriers. Theoretically, this carrier strategy would ameliorate toxicity and improve the biodistribution and tumor selectivity of these agents. We hypothesized specifically that liposomal formulations could shift the biodistribution of EGFR inhibitors such as gefitinib away from skin, bone marrow, and the blood brain barrier, and toward solid tumors

  9. Thyroid Hormone Receptor-β (TRβ) Mediates Runt-Related Transcription Factor 2 (Runx2) Expression in Thyroid Cancer Cells: A Novel Signaling Pathway in Thyroid Cancer.

    Science.gov (United States)

    Carr, Frances E; Tai, Phillip W L; Barnum, Michael S; Gillis, Noelle E; Evans, Katherine G; Taber, Thomas H; White, Jeffrey H; Tomczak, Jennifer A; Jaworski, Diane M; Zaidi, Sayyed K; Lian, Jane B; Stein, Janet L; Stein, Gary S

    2016-08-01

    Dysregulation of the thyroid hormone receptor (TR)β is common in human cancers. Restoration of functional TRβ delays tumor progression in models of thyroid and breast cancers implicating TRβ as a tumor suppressor. Conversely, aberrant expression of the runt-related transcription factor 2 (Runx2) is established in the progression and metastasis of thyroid, breast, and other cancers. Silencing of Runx2 diminishes tumor invasive characteristics. With TRβ as a tumor suppressor and Runx2 as a tumor promoter, a compelling question is whether there is a functional relationship between these regulatory factors in thyroid tumorigenesis. Here, we demonstrated that these proteins are reciprocally expressed in normal and malignant thyroid cells; TRβ is high in normal cells, and Runx2 is high in malignant cells. T3 induced a time- and concentration-dependent decrease in Runx2 expression. Silencing of TRβ by small interfering RNA knockdown resulted in a corresponding increase in Runx2 and Runx2-regulated genes, indicating that TRβ levels directly impact Runx2 expression and associated epithelial to mesenchymal transition molecules. TRβ specifically bound to 3 putative thyroid hormone-response element motifs within the Runx2-P1 promoter ((-)105/(+)133) as detected by EMSA and chromatin immunoprecipitation. TRβ suppressed Runx2 transcriptional activities, thus confirming TRβ regulation of Runx2 at functional thyroid hormone-response elements. Significantly, these findings indicate that a ratio of the tumor-suppressor TRβ and tumor-promoting Runx2 may reflect tumor aggression and serve as biomarkers in biopsy tissues. The discovery of this TRβ-Runx2 signaling supports the emerging role of TRβ as a tumor suppressor and reveals a novel pathway for intervention. PMID:27253998

  10. Down-regulation of aryl hydrocarbon receptor-regulated genes by tumor necrosis factor-alpha and lipopolysaccharide in murine hepatoma Hepa 1c1c7 cells.

    Science.gov (United States)

    Gharavi, Negar; El-Kadi, Ayman O S

    2005-03-01

    Although much is known concerning the effects of inflammation and oxidative stress on the cytochrome P450 1A1 (CYP1A1), little is known about the modulation of other aryl hydrocarbon receptor (AHR)-regulated genes such as glutathione-S-transferase Ya (GST Ya) and NAD(P)H:quinone oxidoreductase (QOR) by inflammation. In the present study, the effect of tumor necrosis factor (TNF)-alpha and lipopolysaccharides (LPS) on the constitutive and inducible expression of the AHR-regulated genes cyp1a1, GST Ya, and QOR was determined in murine hepatoma Hepa 1c1c7 (WT), AHR-deficient (C12), and AHR nuclear translocator protein (ARNT)-deficient (C4) cells. We found that both TNF-alpha and LPS strongly repressed the constitutive expression and the beta-naphthoflavone-mediated induction of cyp1a1, GST Ya, and QOR in WT but not in C12 and C4 cells. The induction of GST Ya and QOR activities and mRNA levels by phenolic antioxidant, tert-butylhydroquinone, through the antioxidant response element was not significantly affected by TNF-alpha or LPS. In addition, a significant increase in reactive oxygen species was observed in WT, C12, and C4 cells treated with TNF-alpha or LPS which was completely prevented by tert-butylhydroquinone. These results show that the down-regulation of AHR-regulated genes by TNF-alpha and LPS is dependent on the presence of both heterodimeric transcription factors, AHR and ARNT. Furthermore, reactive oxygen species may be involved in the down-regulation of AHR-regulated genes. PMID:15627257

  11. Gefitinib Radiosensitizes Stem-Like Glioma Cells: Inhibition of Epidermal Growth Factor Receptor-Akt-DNA-PK Signaling, Accompanied by Inhibition of DNA Double-Strand Break Repair

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Khong Bee, E-mail: dmskkb@nccs.com.sg [Brain Tumour Research Laboratory, Division of Medical Sciences, National Cancer Centre Singapore (Singapore); Zhu Congju; Wong Yinling; Gao Qiuhan; Ty, Albert; Wong, Meng Cheong [Brain Tumour Research Laboratory, Division of Medical Sciences, National Cancer Centre Singapore (Singapore)

    2012-05-01

    Purpose: We compared radiosensitivity of brain tumor stem cells (BTSCs) with matched nonstem glioma cells, and determined whether gefitinib enhanced BTSC radiosensitivity by inhibiting epidermal growth factor receptor (EGFR)-Akt-DNA-dependent protein kinase (DNA-PK) signaling, followed by enhanced DNA double-stand breaks (DSBs) and inhibition of DSB repair. Methods and Materials: Radiosensitivity of stem-like gliomaspheres and nonstem glioma cells (obtained at patient neurosurgical resection) were evaluated by clonogenic assays, {gamma}-H{sub 2}AX immunostaining and cell cycle distribution. Survival of irradiated and nonirradiated NOD-SCID mice intracranially implanted with stem-like gliomaspheres were monitored. Glioma cells treated with gefitinib, irradiation, or both were assayed for clonogenic survival, {gamma}-H{sub 2}AX immunostaining, DNA-PKcs expression, and phosphorylation of EGFR and Akt. Results: Stem-like gliomaspheres displayed BTSC characteristics of self-renewal; differentiation into lineages of neurons, oligodendrocytes, and astrocytes; and initiation of glioma growth in NOD-SCID mice. Irradiation dose-dependently reduced clonogenic survival, induced G{sub 2}/M arrest and increased {gamma}-H{sub 2}AX immunostaining of nonstem glioma cells, but not stem-like gliomaspheres. There was no difference in survival of irradiated and nonirradiated mice implanted with stem-like gliomaspheres. The addition of gefitinib significantly inhibited clonogenic survival, increased {gamma}-H{sub 2}AX immunostaining, and reduced DNA-PKcs expression of irradiated stem-like gliomaspheres, without affecting irradiated-nonstem glioma cells. Gefitinib alone, and when combined with irradiation, inhibited phosphorylation of EGFR (Y1068 and Y1045) and Akt (S473) in stem-like gliomaspheres. In nonstem glioma cells, gefitinib alone inhibited EGFR Y1068 phosphorylation, with further inhibition by combined gefitinib and irradiation. Conclusions: Stem-like gliomaspheres are

  12. Gefitinib Radiosensitizes Stem-Like Glioma Cells: Inhibition of Epidermal Growth Factor Receptor-Akt-DNA-PK Signaling, Accompanied by Inhibition of DNA Double-Strand Break Repair

    International Nuclear Information System (INIS)

    Purpose: We compared radiosensitivity of brain tumor stem cells (BTSCs) with matched nonstem glioma cells, and determined whether gefitinib enhanced BTSC radiosensitivity by inhibiting epidermal growth factor receptor (EGFR)–Akt-DNA–dependent protein kinase (DNA-PK) signaling, followed by enhanced DNA double-stand breaks (DSBs) and inhibition of DSB repair. Methods and Materials: Radiosensitivity of stem-like gliomaspheres and nonstem glioma cells (obtained at patient neurosurgical resection) were evaluated by clonogenic assays, γ-H2AX immunostaining and cell cycle distribution. Survival of irradiated and nonirradiated NOD-SCID mice intracranially implanted with stem-like gliomaspheres were monitored. Glioma cells treated with gefitinib, irradiation, or both were assayed for clonogenic survival, γ-H2AX immunostaining, DNA-PKcs expression, and phosphorylation of EGFR and Akt. Results: Stem-like gliomaspheres displayed BTSC characteristics of self-renewal; differentiation into lineages of neurons, oligodendrocytes, and astrocytes; and initiation of glioma growth in NOD-SCID mice. Irradiation dose-dependently reduced clonogenic survival, induced G2/M arrest and increased γ-H2AX immunostaining of nonstem glioma cells, but not stem-like gliomaspheres. There was no difference in survival of irradiated and nonirradiated mice implanted with stem-like gliomaspheres. The addition of gefitinib significantly inhibited clonogenic survival, increased γ-H2AX immunostaining, and reduced DNA-PKcs expression of irradiated stem-like gliomaspheres, without affecting irradiated-nonstem glioma cells. Gefitinib alone, and when combined with irradiation, inhibited phosphorylation of EGFR (Y1068 and Y1045) and Akt (S473) in stem-like gliomaspheres. In nonstem glioma cells, gefitinib alone inhibited EGFR Y1068 phosphorylation, with further inhibition by combined gefitinib and irradiation. Conclusions: Stem-like gliomaspheres are resistant to irradiation-induced cytotoxicity, G2/M

  13. Involvement of transcription factor encoded by the mi locus in the expression of c-kit receptor tyrosine kinase in cultured mast cells of mice.

    Science.gov (United States)

    Tsujimura, T; Morii, E; Nozaki, M; Hashimoto, K; Moriyama, Y; Takebayashi, K; Kondo, T; Kanakura, Y; Kitamura, Y

    1996-08-15

    The mi locus of mice encodes a member of the basic-helix-loop-helix-leucine zipper (bHLH-Zip) protein family of transcription factors (hereafter called MITF). Cultured mast cells of mi/mi genotype (mi/mi CMCs) did not normally respond to stem cell factor (SCF), a ligand for the c-kit receptor tyrosine kinase. The poor response of mi/mi CMCs to SCF was attributed to the deficient expression of c-kit both the mRNA and protein levels. The purpose of the present study is to investigate the effect of MITF on the transcription of the c-kit gene. First, we introduced cDNA encoding normal (+) MITF or mutant (mi) MITF into mi/mi CMCs using the retroviral vector. Overexpression of (+)-MITF but not mi-MITF normalized the expression of the c-kit and the poor response of mi/mi CMCs to SCF, indicating the involvement of (+)-MITF in the c-kit gene transactivation. Second, we analyzed the promoter of the c-kit gene. Three CANNTG motifs recognized by bHLH-Zip-type transcription factors were conserved between the mouse and human c-kit promoters. Among these three CANNTG motifs, only the CACCTG motif (nt -356 to -351) was specifically bound by (+)-MITF. When the luciferase gene under the control of the c-kit promoter was contransfected into NIH/3T3 fibroblasts with cDNA encoding (+)-MITF or mi-MITF, the luciferase activity significantly increased only when (+)-MITF cDNA was cotransfected. The deletion of the promoter region containing the CACCTG motif or the mutation of the CACCTG to CTCCAG abolished the transactivation effect of (+)-MITF, indicating that (+)-MITF transactivated the c-kit gene through the CACCTG motif. When the luciferase gene under the control of the c-kit promoter was introduced into the FMA3 mastocytoma and FEC-P1 myeloid cell lines, remarkable luciferase activity was observed only in FMA3 cells. Thus, the involvement of (+)-MITF in the c-kit transactivation appeared to be specific to the mast cell lineage. PMID:8695840

  14. Dopamine receptor regulating factor, DRRF: a zinc finger transcription factor.

    Science.gov (United States)

    Hwang, C K; D'Souza, U M; Eisch, A J; Yajima, S; Lammers, C H; Yang, Y; Lee, S H; Kim, Y M; Nestler, E J; Mouradian, M M

    2001-06-19

    Dopamine receptor genes are under complex transcription control, determining their unique regional distribution in the brain. We describe here a zinc finger type transcription factor, designated dopamine receptor regulating factor (DRRF), which binds to GC and GT boxes in the D1A and D2 dopamine receptor promoters and effectively displaces Sp1 and Sp3 from these sequences. Consequently, DRRF can modulate the activity of these dopamine receptor promoters. Highest DRRF mRNA levels are found in brain with a specific regional distribution including olfactory bulb and tubercle, nucleus accumbens, striatum, hippocampus, amygdala, and frontal cortex. Many of these brain regions also express abundant levels of various dopamine receptors. In vivo, DRRF itself can be regulated by manipulations of dopaminergic transmission. Mice treated with drugs that increase extracellular striatal dopamine levels (cocaine), block dopamine receptors (haloperidol), or destroy dopamine terminals (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine) show significant alterations in DRRF mRNA. The latter observations provide a basis for dopamine receptor regulation after these manipulations. We conclude that DRRF is important for modulating dopaminergic transmission in the brain. PMID:11390978

  15. Receptor Expression in Rat Skeletal Muscle Cell Cultures

    Science.gov (United States)

    Young, Ronald B.

    1996-01-01

    One on the most persistent problems with long-term space flight is atrophy of skeletal muscles. Skeletal muscle is unique as a tissue in the body in that its ability to undergo atrophy or hypertrophy is controlled exclusively by cues from the extracellular environment. The mechanism of communication between muscle cells and their environment is through a group of membrane-bound and soluble receptors, each of which carries out unique, but often interrelated, functions. The primary receptors include acetyl choline receptors, beta-adrenergic receptors, glucocorticoid receptors, insulin receptors, growth hormone (i.e., somatotropin) receptors, insulin-like growth factor receptors, and steroid receptors. This project has been initiated to develop an integrated approach toward muscle atrophy and hypertrophy that takes into account information on the populations of the entire group of receptors (and their respective hormone concentrations), and it is hypothesized that this information can form the basis for a predictive computer model for muscle atrophy and hypertrophy. The conceptual basis for this project is illustrated in the figure below. The individual receptors are shown as membrane-bound, with the exception of the glucocorticoid receptor which is a soluble intracellular receptor. Each of these receptors has an extracellular signalling component (e.g., innervation, glucocorticoids, epinephrine, etc.), and following the interaction of the extracellular component with the receptor itself, an intracellular signal is generated. Each of these intracellular signals is unique in its own way; however, they are often interrelated.

  16. Neuromedin B receptors regulate EGF receptor tyrosine phosphorylation in lung cancer cells

    OpenAIRE

    Moody, Terry W.; Berna, Marc J.; Mantey, Samuel; Sancho, Veronica; Ridnour, Lisa; Wink, David A.; Chan, Daniel; Giaccone, Giuseppe; Jensen, Robert T.

    2010-01-01

    Neuromedin B (NMB), a member of the bombesin family of peptides, is an autocrine growth factor for many lung cancer cells. The present study investigated the ability of NMB to cause transactivation of the epidermal growth factor (EGF) receptor in lung cancer cells. By Western blot, addition of NMB or related peptides to NCI-H1299 human non-small cell lung cancer (NSCLC) cells, caused phosphorylation of Tyr1068 of the EGF receptor. The signal was amplified using NCI-H1299 cells stably transect...

  17. Activation of Epidermal Growth Factor Receptor/p38/Hypoxia-inducible Factor-1α Is Pivotal for Angiogenesis and Tumorigenesis of Malignantly Transformed Cells Induced by Hexavalent Chromium.

    Science.gov (United States)

    Kim, Donghern; Dai, Jin; Park, Youn-Hee; Fai, Leonard Yenwong; Wang, Lei; Pratheeshkumar, Poyil; Son, Young-Ok; Kondo, Kazuya; Xu, Mei; Luo, Jia; Shi, Xianglin; Zhang, Zhuo

    2016-07-29

    Hexavalent chromium (Cr(VI))-containing compounds are well established environmental carcinogens. Most mechanistic investigations of Cr(VI)-induced carcinogenesis focus on oxidative stress and various cellular responses, leading to malignant cell transformation or the first stage of metal-induced carcinogenesis. The development of malignantly transformed cells into tumors that require angiogenesis is the second stage. This study focuses on the second stage, in particular, the role of EGF receptor (EGFR) signaling in angiogenesis and tumorigenesis of Cr(VI)-transformed cells. Our preliminary studies have shown that EGFR is constitutively activated in Cr(VI)-transformed cells, in lung tissue from Cr(VI)-exposed animals, and in lung tumor tissue from a non-smoking worker occupationally exposed to Cr(VI) for 19 years. Using in vitro and in vivo models, the present study has investigated the role of EGFR in angiogenesis of Cr(VI)-transformed cells. The results show that Cr(VI)-transformed cells are angiogenic. Hypoxia-inducible factor-1α, pro-angiogenic protein matrix metalloproteinase 1, and VEGF are all highly expressed in Cr(VI)-transformed cells, in lung tissue from animals exposed to Cr(VI), and in lung tumor tissue from a non-smoking worker occupationally exposed to Cr(VI) for 19 years. p38 MAPK is also activated in Cr(VI)-transformed cells and in human lung tumor tissue. Inhibition of EGFR reduces p38 MAPK, resulting in decreased expression of hypoxia-inducible factor-1α, metalloproteinase 1, and VEGF, leading to suppressions of angiogenesis and tumorigenesis. Overall, the present study has demonstrated that EGFR plays an important role in angiogenesis and tumorigenesis of Cr(VI)-transformed cells. PMID:27226640

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

    International Nuclear Information System (INIS)

    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

  19. Differential tumor necrosis factor receptor 2-mediated editing of virus-specific CD8+ effector T cells

    OpenAIRE

    Turner, Stephen J.; La Gruta, Nicole L.; Stambas, John; Diaz, Gabriela; Doherty, Peter C.

    2004-01-01

    Much of the CD8+ T cell response in H2b mice with influenza pneumonia is directed at the nucleoprotein366-374 (NP366) and acid polymerase224-233 (PA224) peptides presented by the H2Db MHC class I glycoprotein. These DbNP366- and DbPA224-specific T cell populations are readily analyzed by staining with tetrameric complexes of MHC+ peptide (tetramers) or by cytokine production subsequent to in vitro stimulation with the cognate peptides. The DbPA224-specific CD8+ effector T cells make more tumo...

  20. Epidermal growth factor receptor tyrosine kinase (EGFR-TK) mutation testing in adults with locally advanced or metastatic non-small cell lung cancer : a systematic review and cost-effectiveness analysis

    NARCIS (Netherlands)

    Westwood, Marie; Joore, Manuela; Whiting, Penny; van Asselt, Thea; Ramaekers, Bram; Armstrong, Nigel; Misso, Kate; Severens, Johan; Kleijnen, Jos

    2014-01-01

    BACKGROUND: Non-small cell lung cancer (NSCLC) is the most common form of lung cancer. Some epidermal growth factor receptor tyrosine kinase (EGFR-TK) mutations make tumours responsive to treatment with EGFR-TK inhibitors (EGFR-TKIs) but less responsive to treatment with standard chemotherapy. Patie

  1. The emerging role of epidermal growth factor receptor (EGFR) inhibitors in first-line treatment for patients with advanced non-small cell lung cancer positive for EGFR mutations

    OpenAIRE

    Okamoto, Isamu; Mitsudomi, Tetsuya; Nakagawa, Kazuhiko; Fukuoka, Masahiro

    2010-01-01

    Gefitinib and erlotinib, small-molecule tyrosine kinase inhibitors (TKIs) of the epidermal growth factor receptor (EGFR), were the first molecularly targeted agents to become clinically available for the treatment of non-small cell lung cancer (NSCLC). During the course of their clinical development, it has become clear that the substantial clinical benefit associated with EGFR-TKIs is limited ...

  2. Epidermal growth factor receptor tyrosine kinase (EGFR-TK) mutation testing in adults with locally advanced or metastatic non-small cell lung cancer: A systematic review and cost-effectiveness analysis

    NARCIS (Netherlands)

    M. Westwood (Marie); M.A. Joore (Manuela); P. Whiting (Penny); T. van Asselt (Thea); B.L.T. Ramaekers (Bram); N. Armstrong (Nigel); K. Misso (Kate); J.L. Severens (Hans); J. Kleijnen (Jos)

    2014-01-01

    markdownabstract__Abstract__ Background: Non-small cell lung cancer (NSCLC) is the most common form of lung cancer. Some epidermal growth factor receptor tyrosine kinase (EGFR-TK) mutations make tumours responsive to treatment with EGFR-TK inhibitors (EGFR-TKIs) but less responsive to treatment wit

  3. High expression of CD40 on B-cell precursor acute lymphoblastic leukemia blasts is an independent risk factor associated with improved survival and enhanced capacity to up-regulate the death receptor CD95

    NARCIS (Netherlands)

    A. Troeger (Anja); L. Glouchkova (Ludmila); B. Ackermann (Birgit); G. Escherich (Gabriele); R. Meisel (Roland); H. Hanenberg (Helmut); M.L. den Boer (Monique); R. Pieters (Rob); G.E. Janka-Schaub (Gritta); U. Goebel (Ulrich); H.J. Laws; D. Dilloo (Dagmar)

    2008-01-01

    textabstractCD40 and CD27, members of the tumor necrosis factor receptor (TNFR) family, are critical regulators of lymphocyte growth and differentiation. In B-cell precursor acute lymphoblastic leukemia (BCP-ALL), we prospectively assessed the impact of CD40 and CD27 on outcome in 121 children treat

  4. Genetic variants in epidermal growth factor receptor pathway genes and risk of esophageal squamous cell carcinoma and gastric cancer in a Chinese population.

    Directory of Open Access Journals (Sweden)

    Wen-Qing Li

    Full Text Available The epidermal growth factor receptor (EGFR signaling pathway regulates cell proliferation, differentiation, and survival, and is frequently dysregulated in esophageal and gastric cancers. Few studies have comprehensively examined the association between germline genetic variants in the EGFR pathway and risk of esophageal and gastric cancers. Based on a genome-wide association study in a Han Chinese population, we examined 3443 SNPs in 127 genes in the EGFR pathway for 1942 esophageal squamous cell carcinomas (ESCCs, 1758 gastric cancers (GCs, and 2111 controls. SNP-level analyses were conducted using logistic regression models. We applied the resampling-based adaptive rank truncated product approach to determine the gene- and pathway-level associations. The EGFR pathway was significantly associated with GC risk (P = 2.16×10(-3. Gene-level analyses found 10 genes to be associated with GC, including FYN, MAPK8, MAP2K4, GNAI3, MAP2K1, TLN1, PRLR, PLCG2, RPS6KB2, and PIK3R3 (P<0.05. For ESCC, we did not observe a significant pathway-level association (P = 0.72, but gene-level analyses suggested associations between GNAI3, CHRNE, PAK4, WASL, and ITCH, and ESCC (P<0.05. Our data suggest an association between specific genes in the EGFR signaling pathway and risk of GC and ESCC. Further studies are warranted to validate these associations and to investigate underlying mechanisms.

  5. Squamous cell carcinoma of external auditory canal lacking epidermal growth factor receptor protein overexpression, in an elderly Omani with oculocutaneous albinism treated with palliative radiotherapy

    Science.gov (United States)

    Furrukh, Muhammad; Mufti, Taha; Hamid, Rana Shoaib; Qureshi, Asim

    2014-01-01

    We report a case of squamous cell carcinoma of external auditory canal in an Omani man with oculocutaneous albinism. The disease mimicked inflammatory process revealing positive cultures for various microorganisms during the course of his illness. He was eventually biopsied to rule out atypical infective process or presence of malignancy. He was staged as T4N0M0 and treated with radical doses of palliative radiation therapy which was very well tolerated and resulted in a complete resolution of disease clinically and a major soft tissue response on radiological imaging. Another unique finding was the absence of epidermal growth factor receptor (EGFR) protein overexpression in the tumour specimen. More than 90% of mucosal squamous cell carcinoma (SCC) involving the head and neck region overexpress the EGFR protein in normal skin patients. SCC is the predominant cutaneous malignancy in albinos, and the presence of EGFR protein overexpression in cutaneous SCC is believed to be 56–58% in normal skin patients. The scientific literature is scarce on reporting incidence of EGFR overexpression in either cutaneous or mucosal SCC in albinos, and it remains to be defined whether being albino is the cause for its absence. PMID:24907210

  6. Complete remission through icotinib treatment in Non-small cell lung cancer epidermal growth factor receptor mutation patient with brain metastasis: A case report

    Directory of Open Access Journals (Sweden)

    Wang Tao

    2016-02-01

    Full Text Available Brain metastasis (BM has been universally recognized as a poor prognostic factor in non-small cell lung cancer (NSCLC. Epidermal growth factor receptor (EGFR tyrosine kinase inhibitors (TKIs have shown efficacy in treating BM with an EGFR mutation. This paper reports a case of BM patient with EGFR-mutated NSCLC. According to the findings, a complete remission (CR of the BM was achieved by icotinib treatment without conducting a radiotherapy, which was followed by a resection of the primary lung cancer lesion and lymph nodes. After one-year follow-up, the disease progressed to liver metastasis and liver lesion biopsy showed a T790M mutation. The patient responded well to the combination treatment of AZD9291 and icotinib after the failure of transcatheter arterial chemoembolization (TACE. This case report suggests that icotinib has a sustainable anticancer response to BM and the combination with icotinib and AZD9291 is effective for liver metastasis with T790M.

  7. Radiotherapy for asymptomatic brain metastasis in epidermal growth factor receptor mutant non-small cell lung cancer without prior tyrosine kinase inhibitors treatment: a retrospective clinical study

    International Nuclear Information System (INIS)

    Non-small cell lung cancer (NSCLC) with brain metastasis (BM) harboring an epidermal growth factor receptor (EGFR) mutation shows good response to tyrosine kinase inhibitors (TKIs). This study is to assess the appropriate timing of brain radiotherapy (RT) for asymptomatic BM in EGFR mutant NSCLC patients. There were 628 patients diagnosed with EGFR mutant NSCLC between October 2005 and December 2011. Treatment outcomes had been retrospectively evaluated in 96 patients with asymptomatic BM without prior TKI treatment. 39 patients received first-line brain RT, 23 patients received delayed brain RT, and 34 patients did not receive brain RT. With a median follow-up of 26 months, the 2-year OS was 40.6 %. Univariate analyses revealed that ECOG performance status (p = 0.006), other distant metastases (p = 0.002) and first line systemic treatment (p = 0.032) were significantly associated with overall survival (OS). Multivariate analyses revealed that other sites of distant metastases (p = 0.030) were prognostic factor. The timing of brain RT was not significantly related to OS (p = 0.246). The 2-year BM progression-free survival (PFS) was 26.9 %. Brain RT as first-line therapy failed to demonstrate a significant association with BM PFS (p = 0.643). First-line brain RT failed to improve long-term survival in TKI-naïve EGFR mutant NSCLC patients with asymptomatic BM. Prospective studies are needed to validate these clinical findings

  8. INHIBITION OF PROTEIN TYROSINE PHOSPHATASE ACTIVITY MEDIATES EPIDERMAL GROWTH FACTOR RECEPTOR SIGNALING IN HUMAN AIRWAY EPITHELIAL CELLS

    Science.gov (United States)

    Epidemiological studies have implicated zinc in the toxicity of ambient particulate matter (PM) inhalation. We previously showed that exposure to metal-laden PM inhibits protein tyrosine phosphatase (PTP) activity in human primary bronchial epithelial cells (HAEC) and leads t...

  9. Nitric oxide from inflammatory origin impairs neural stem cell proliferation by inhibiting epidermal growth factor receptor signaling

    OpenAIRE

    Bruno Pereira Carreira; Maria Inês Morte; Ana Isabel Santos; Ana Sofia Lourenço; António Francisco Ambrósio; Carvalho, Caetana M.; Araújo, Inês M.

    2014-01-01

    Neuroinflammation is characterized by activation of microglial cells, followed by production of nitric oxide (NO), which may have different outcomes on neurogenesis, favoring or inhibiting this process. In the present study, we investigated how the inflammatory mediator NO can affect proliferation of neural stem cells (NSCs), and explored possible mechanisms underlying this effect. We investigated which mechanisms are involved in the regulation of NSC proliferation following treatment with an...

  10. Cellular Uptake and Cytotoxic Effect of Epidermal Growth Factor Receptor Targeted and Plitidepsin Loaded Co-Polymeric Polymersomes on Colorectal Cancer Cell Lines.

    Science.gov (United States)

    Goñi-de-Cerio, Felipe; Thevenot, Julie; Oliveira, Hugo; Pérez-Andrés, Encarnación; Berra, Edurne; Masa, Marc; Suárez-Merino, Blanca; Lecommandoux, Sébastien; Heredia, Pedro

    2015-11-01

    Encapsulating chemotherapy drugs in targeted nanodelivery systems is one of the most promising approaches to tackle cancer disease, avoiding side effects of common treatment. In the last decade, several nanocarriers with different nature have been tested, but polypeptide-based copolymers have attracted considerable attention for their biocompatibility, controlled and slow biodegradability as well as their low toxicity. In this work, we synthesized, characterized and evaluated poly(trimethylene carbonate)-bock-poly(L-glutamic acid) derived polymersomes, targeted to epidermal growth factor receptor (EGFR), loaded with plitidepsin and ultimately tested in HT29 and LS174T colorectal cancer cell lines for specificity and efficacy. Furthermore, morphology, physico-chemical properties and plitidepsin loading were carefully investigated. A thorough in vitro cytotoxicity analysis of the unloaded polymersomes was carried out for biocompatibility check, studying viability, cell membrane asymmetry and reactive oxygen species levels. Those cytotoxicity assays showed good biocompatibility for plitidepsin-unloaded polymersomes. Cellular uptake and cytotoxic effect of EGFR targeted and plitidepsin loaded polymersome indicated that colorectal cancer cell lines were.more sensitive to anti-EGFR-drug-loaded than untargeted drug-loaded polymersomes. Also, in both cell lines, the use of untargeted polymersomes greatly reduced plitidepsin cytotoxicity as well as the cellular uptake, indicating that the use of this targeted nanocarrier is a promising approach to tackle colorectal cancer disease and avoid the undesired effects of the usual treatment. Furthermore, in vivo assays support the in vitro conclusions that EGFR targeted polymersomes could be a good drug delivery system. This work provides a proof of concept for the use of encapsulated targeted drugs as future therapeutic treatments for cancer. PMID:26554161

  11. Biomarkers of erlotinib response in non-small cell lung cancer tumors that do not harbor the more common epidermal growth factor receptor mutations

    Science.gov (United States)

    López-Ayllón, Blanca D; de Castro-Carpeño, Javier; Rodriguez, Carlos; Pernía, Olga; de Cáceres, Inmaculada Ibañez; Belda-Iniesta, Cristobal; Perona, Rosario; Sastre, Leandro

    2015-01-01

    Non-small cell lung cancer (NSCLC) represents approximately 85% of all lung cancers, which are the leading cause of cancer-related deaths in the world. Tyrosine kinase inhibitors such as erlotinib represent one therapeutic options presently recommended for tumors produced by activating mutations in the gene coding of epidermal growth factor receptor (EGFR). The aim of this study is the identification of possible biomarkers for tumor sensitivity to erlotinib in the absence of the main EGFR mutations. The erlotinib sensitivity of cells isolated from 41 untreated NSCLC patients was determined and compared with the presence of the more frequent EGFR mutations. Several patients had tumor cells highly sensitive to erlitinib in the absence of the EGFR mutations analyzed. The gene expression profile of 3 erlotinib-sensitive tumors was compared with that of 4 resistant tumors by DNA microarray hybridization. Sixteen genes were expressed at significantly higher levels in the resistant tumors than in the sensitive tumors. The possible correlation between erlotinib sensitivity and the expression of these genes was further analyzed using the data for the NSCLC, breast cancer and colon cancer cell lines of the NCI60 collection. The expression of these genes was correlated with the overall survival of 5 patients treated with erlotinib, according to The Cancer Genome Atlas (TCGA) database. Overlapping groups of 7, 5 and 3 genes, including UGT1A6, TRIB3, MET, MMP7, COL17A1, LCN2 and PTPRZ1, whose expression correlated with erlotinib activity was identified. In particular, low MET expression levels showed the strongest correlation. PMID:26045797

  12. Human epidermal growth factor receptor residue covalently cross-linked to epidermal growth factor

    International Nuclear Information System (INIS)

    An epidermal growth factor (EGF) receptor monoclonal antibody (mAb), mAb LA22, was used to analyze the covalent coupling of human EGF receptors to mouse EGF by the amine-reactive cross-linking agent disuccinimidyl suberate. A soluble Mr 105,000 truncated form of the receptor secreted by A-431 epidermoid carcinoma cells and consisting of the ligand-binding extracellular domain was cross-linked to 125I-labeled EGF. Digestion of this complex with an endoproteinase that specifically cleaves at the COOH side of glutamyl residue released a single radiolabeled glycosylated fragment of Mr18,000 that reacted with mAb LA22. The receptor residue(s) involved in the covalent coupling of rat 125I-labeled transforming growth factor α was similarly localized to this region of the receptor. This receptor interval, which included two glycosylated asparaginyl residues at positions 328 and 337, contained but three amino acid residues that were potentially reactive with disuccinimidyl suberate: Lys-332, Lys-333, and Lys-336. These results indicated that disuccinimidyl suberate cross-linked the NH2 group of EGF residue Asn-1 to the human EGF receptor residue Lys-336. The results further suggest that EGF and transforming growth factor α, two members of the EGF family of peptide growth factors, interact with closely apposed or identical features of the receptor

  13. Biochemical and biological properties of the nerve growth factor receptor

    International Nuclear Information System (INIS)

    We have utilized a monoclonal antibody (192-IgG) to study the rat nerve growth factor receptor. After intraocular injection, 125I-192-IgG was retrogradely transported in sympathetic neuronal axons to the superior cervical ganglion. When the sciatic nerve was ligated to induce the accumulation of axonally transported materials, 192-IgG immunostaining was observed on both sides of the ligature, indicating that NGF receptors are transported in both orthograde and retrograde directions. By using 125I-NGF crosslinking and 192-IgG immunoprecipitation, we detected receptor molecules throughout the rat brain, thereby supporting the hypothesis that NGF is active in the central nervous system. We also discovered that sciatic nerve transection leads to a dramatic increase in the amount of NGF receptor found in the distal portion of the nerve. Immunostaining revealed that all Schwann cells in the distal axotomized nerve were expressing NGF receptors. We examined phosphorylation of NGF receptor in cultured sympathetic neurons and PC12 cells. We also examined pharmacological effects of 192-IgG. Systemic injection of 192-IgG into neonatal rats caused a permanent partial sympathectomy in a dose-dependent manner; a maximum of 50% of the cells were killed

  14. Contribution of Nitric Oxide and Epidermal Growth Factor Receptor in Anti-Metastatic Potential of Paclitaxel in Human Liver Cancer Cell (HebG2)

    International Nuclear Information System (INIS)

    Paclitaxel is a general antineoplastic drug used against different types of experimental and human tumors. Several anti-cancer drugs have been shown to stimulate nitric oxide (NO) production, which has been shown to affect many aspects of tumor biology. Objective: This study was initiated to determine if paclitaxel stimulates NO production in HebG2 cells, and if so, whether NO interferes with the metastatic potential of HebG2 cells and contributes to paclitaxel cytotoxicity. In addition, we sought to determine the relationship between NO production and the expression of epidermal growth factor receptor (EGFR) and matrix metalloproteinases (MMPs) in HebG2 cells. Materials and Methods: The effects of paclitaxel (0.I-1000nM) on surviving fraction, NO production and the expression of EGFR, MMP-2 and MMP-9 were studied in human liver cancer cells (HebG2). Paclitaxel resulted in a significant dose dependent decrease in the surviving fraction of HebG2 cells. A 62% and 86% decrease in the surviving fraction was attained at 10nM and 100nM paclitaxeJ, respectively. PacIitaxel produced a significant increase in NO production, starting from InM. A 64% and 111 % increase in NO production was attained after exposure to 10nM and 100nM of paclitaxel, respectively. In all of the HebG2 cells treated with paclitaxel (1.0-1000nM) mRNA specific for EGFR, MMP-2 and MMP-9 were undetectable. However, untreated HcbG2 cells and those treated with paclitaxel (0.1nM) expressed mRNA specific for these markers. This study suggests that: (I) increased production of NO may contribute to pacIitaxel's cytotoxicity against HebG2 cells, (2) paclitaxel may inhibit tumor metastasis via inhibition of the expression of EGFR and MMPs and (3) an inverse correlation exists between NO production and expression of EGFR and MMPs

  15. Redox-dependent regulation of epidermal growth factor receptor signaling.

    Science.gov (United States)

    Heppner, David E; van der Vliet, Albert

    2016-08-01

    Tyrosine phosphorylation-dependent cell signaling represents a unique feature of multicellular organisms, and is important in regulation of cell differentiation and specialized cell functions. Multicellular organisms also contain a diverse family of NADPH oxidases (NOXs) that have been closely linked with tyrosine kinase-based cell signaling and regulate tyrosine phosphorylation via reversible oxidation of cysteine residues that are highly conserved within many proteins involved in this signaling pathway. An example of redox-regulated tyrosine kinase signaling involves the epidermal growth factor receptor (EGFR), a widely studied receptor system with diverse functions in normal cell biology as well as pathologies associated with oxidative stress such as cancer. The purpose of this Graphical Redox Review is to highlight recently emerged concepts with respect to NOX-dependent regulation of this important signaling pathway. PMID:26722841

  16. Activation of histamine H4 receptors decreases epithelial-to-mesenchymal transition progress by inhibiting transforming growth factor-β1 signalling pathway in non-small cell lung cancer.

    Science.gov (United States)

    Cai, Wen-Ke; Hu, Jing; Li, Teng; Meng, Jing-Ru; Ma, Xue; Yin, Sun-Jun; Zhao, Can-Hu; He, Gong-Hao; Xu, Gui-Li

    2014-04-01

    Previous investigations found that epithelial-to-mesenchymal transition (EMT) was an important character of non-small cell lung cancer (NSCLC) and it was also suggested that histamine H4 receptors may have a role in preventing EMT progress in certain kind of tumours. However, the effect of H4 receptor activation on EMT progress of NSCLC and its potential mechanisms remain unclear. Therefore, we performed both in vitro and in vivo experiments to explore the effects of specific H4 receptor agonist 4-methylhistamine and antagonist JNJ7777120 on EMT progress. We showed the expression of H4 receptors in NSCLC and found that 4-methylhistamine increased the expression of the epithelial marker E-cadherin and decreased the expression of Vimentin, the mesenchymal marker, in both NSCLC cell lines and xenograft NSCLC tumours. Pretreatment with JNJ7777120 or H4 receptor gene silencing decreased while overexpression of H4 receptors facilitated this effect of 4-methylhistamine. Furthermore, we showed that down-regulation of cyclic adenosine monophosphate (cAMP) was the secondary signalling after H4 receptor activation, which in turn resulted in inactivation of transforming growth factor-β1 (TGF-β1) pathway and down-regulation of several important EMT inducing factors such as ZEB1, Snail and Slug. In conclusion, these findings revealed the anti-EMT effect of histamine H4 receptor activation in NSCLC, which provide novel insight into the development mechanism of NSCLC; and H4 receptors may be a new therapeutic target for NSCLC treatment. PMID:24447834

  17. Epidermal growth factor receptor is a possible predictor of sensitivity to chemoradiotherapy in the primary lesion of esophageal squamous cell carcinoma

    International Nuclear Information System (INIS)

    Chemoradiotherapy (CRT) is currently performed for patients with esophageal squamous cell carcinoma (SCC). Some reports have revealed that patients who responded well to CRT had favorable outcomes, whereas poor responders conversely showed a worse prognosis. The aim of this study was to identify molecular markers predicting sensitivity to CRT. We reviewed 62 patients with T3-4, N-any, and M-any esophageal SCC treated with definitive CRT. The regimen comprised protracted 5-fluorouracil infusion and a 2-h infusion of cisplatinum combined with radiation therapy (2 Gy/day) at a total radiation dose of 60 Gy. The expressions of epidermal growth factor receptor (EGFR), vascular endothelial growth factor, cyclin D1, and proliferating cell nuclear antigen were investigated immunohistochemically in biopsy specimens obtained before treatment from all 62 patients. The immunoreactivities were compared with responsiveness to CRT, as evaluated by endoscopy. The complete response rate of the primary tumor estimated by endoscopy was 62% (13/21) in patients in the EGFR-positive group. The difference in the CR rate between EGFR-positive and -negative groups was significant (p=0.037). The immunoreactivities of the other molecular markers did not show a significant correlation with the responsiveness of the primary lesion to CRT. Multiple logistic regression analysis revealed that positive immunostaining for EGFR was significantly correlated with primary CR for CRT in esophageal SCC. Among 62 patients with esophageal SCC, differences in the responsiveness of primary lesions to CRT were correlated with EGFR immunoreactivity assessed in the biopsy specimens. These results suggest that EGFR may help to predict the response of primary sites to definitive CRT in esophageal SCC, although the results should be confirmed in a larger, more homogeneous series. (author)

  18. Selective decrease in cell surface expression and mRNA level of the 55-kDa tumor necrosis factor receptor during differentiation of HL-60 cells into macrophage-like but not granulocyte-like cells

    DEFF Research Database (Denmark)

    Winzen, R; Wallach, D; Engelmann, H;

    1992-01-01

    Expression of the two known receptors for TNF was studied in the promyelocytic leukemia cell line HL-60 before and after differentiation of the cells along the granulocyte lineage (induced by incubation with retinoic acid), or along the macrophage lineage (induced by incubation with the phorbol...

  19. Epidermal growth factor receptor genotype in plasma DNA and outcome of chemotherapy in the Chinese patients with advanced non-small cell lung cancer

    Institute of Scientific and Technical Information of China (English)

    ZHUO Ming-lei; DUAN Jian-chun; WANG Yu-yan; GUO Qing-zhi; LIU Xu-yi; LIU Ning-hong; WANG Jie; WU Mei-na; ZHAO Jun; Sonya Wei Song; BAI Hua; WANG Shu-hang; YANG Lu; AN Tong-tong; WANG Xin

    2011-01-01

    Background The genotype of epidermal growth factor receptor (EGFR) is associated with tyrosine kinase inhibitor and effectiveness of therapy,but its role in cytotoxic chemotherapy is still unknown.Previous studies indicated that certain EGFR mutations were associated with response and progression free survival following platinum based chemotherapy.Our recent studies have identified that EGFR genotypes in the tumour tissues were not associated with response to the first-line chemotherapy in Chinese patients with advanced non-small cell lung cancer (NSCLC).In this study,we investigated associations of EGFR genotypes from plasma of patients with advanced NSCLC and response to first-line chemotherapy and prognosis.Methods We enrolled 145 advanced NSCLC patients who had received first-line chemotherapy in our department.We examined plasma EGFR genotypes for these patients and associations of EGFR mutations with response to chemotherapy and clinical outcomes.Results There were 54 patients with known EGFR mutations and 91 cases of wild types.No significant difference was detected in the response rate to first-line chemotherapy between mutation carriers and wild-type patients (37.0% vs.31.9%).The median survival time and 1-,2-year survival rates were higher in mutation carriers than wild-types (24months vs.18 months,85.7% vs.65.7% and 43.7% vs.25.9%,P=0.047).Clinical stage (IV vs.Ⅲb),response to the first-line chemotherapy (partial vs.no) and EGFR genotype were independent prognostic factors.Conclusion Plasma EGFR mutations in the Chinese patients with advanced NSCLC is not a predictor for the response to first-line chemotherapy,but an independent prognostic factor indicating longer survival.

  20. Radiotherapy and receptor of epidermal growth factor

    International Nuclear Information System (INIS)

    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

  1. Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitors for Elderly Patients with Advanced Non-Small Cell Lung Cancer

    OpenAIRE

    A. Zaniboni; Meriggi, F.

    2010-01-01

    Lung cancer is the leading cause of cancer-related mortality in both men and women and approximately 219,440 new cases of nonsmall cell lung cancer (NSCLC) were estimated to occur in the USA in 2009, which caused 159,390 NSCLC-related deaths. More than 50% of cases of advanced NSCLC are diagnosed in patients older than age 65, and recent Surveillance Epidemiology and End Results (SEERs) data suggest that the median age at diagnosis is 70 years. Until recently, the disease has been undertr...

  2. A lactobacillus rhamnosus GG-derived soluble protein, p40, stimulates ligand release from intestinal epithelial cells to transactivate epidermal growth factor receptor

    Science.gov (United States)

    Protein p40, a Lactobacillus rhamnosus GG (LGG)-derived soluble protein, ameliorates intestinal injury and colitis, reduces apoptosis and preserves barrier function by activation of EGF receptor (EGFR) in intestinal epithelial cells. The aim of this study was to determine the mechanisms by which p40...

  3. The ontogeny of epidermal growth factor receptors during mouse development

    International Nuclear Information System (INIS)

    In an attempt to understand the role(s) of epidermal growth factor (EGF) in vivo during murine development, we have examined the 125I-EGF binding characteristics of EGF-receptors in membrane preparations of tissues from the 12th day of gestation to parturition. Using autoradiography, the earliest time that we could detect EGF-receptors was on trophoblast cells cultured for 3 days as blastocyst outgrowths. Trophoblast eventually forms a large portion of the placenta, where EGF-receptors have long been recognized. We measured the number and affinity of EGF-receptors on tissues dissected from conceptuses from the 12th day of gestation in order to identify a stage when tissues may be most sensitive to EGF. Whereas the number of EGF receptors increases during gestation for all tissues examined, the affinity of the receptors declines for carcass and placenta and remains relatively unchanged for brain and liver. This suggests that EGF may function differently throughout development. Our hypothesis is that EGF (or its embryonic equivalent) initially stimulates proliferation in embryonic cells and then stimulates differentiation as the tissues mature. In the adult, its main role could be to stimulate tissue repair after damage

  4. Molecular mechanism underlying the synergistic interaction between trifluorothymidine and the epidermal growth factor receptor inhibitor erlotinib in human colorectal cancer cell lines

    NARCIS (Netherlands)

    Bijnsdorp, Irene V.; Kruyt, Frank A. E.; Fukushima, Masakazu; Smid, Kees; Gokoel, Shanti; Peters, Godefridus J.

    2010-01-01

    The pyrimidine trifluorothymidine (TFT) inhibits thymidylate synthase (TS) and can be incorporated into the DNA. TFT, as part of TAS-102, is clinically evaluated in phase II studies as an oral chemotherapeutic agent. Erlotinib is a tyrosine kinase inhibitor of the epidermal growth factor receptor (E

  5. Computed Tomography-Guided Core-Needle Biopsy Specimens Demonstrate Epidermal Growth Factor Receptor Mutations in Patients with Non-Small-Cell Lung Cancer

    International Nuclear Information System (INIS)

    Background: Target therapy with a new class of epidermal growth factor receptor (EGFR) inhibitors shows improved clinical response in EGFR gene-mutated lung cancers. Purpose: To evaluate the use of computed tomography (CT)-guided core-needle biopsy specimens for the assessment of EGFR gene mutation in non-small-cell lung cancer (NSCLC). Material and Methods: Seventeen (nine males, eight females) patients with advanced NSCLC were enrolled in this study. All patients underwent CT-guided core-needle biopsy of the lung tumor prior to treatment with the EGFR inhibitor gefitinib. There were no life-threatening complications of biopsy. The specimens were sent fresh-frozen for EGFR mutation analysis and histopathological study. Results: There were 12 (70.6%) EGFR gene mutants and five (29.4%) nonmutants. The objective response rate to gefitinib therapy was 73.3% (11 of 15 patients), with 91.7% (11 of 12 mutants) for the mutant group and 0% for the nonmutant group. Conclusion: CT-guided core-needle biopsy of advanced NSCLC enables the acquisition of sufficient tissue for EGFR gene mutation analysis

  6. Alpha-fetoprotein triggers hepatoma cells escaping from immune surveillance through altering the expression of Fas/FasL and tumor necrosis factor related apoptosis-inducing ligand and its receptor of lymphocytes and liver cancer cells

    Institute of Scientific and Technical Information of China (English)

    Meng-Sen Li; Qiu-Ling Ma; Qian Chen; Xin-Hua Liu; Ping-Feng Li; Guo-Guang Du; Gang Li

    2005-01-01

    AIM: To investigate the mechanism of α-fetoprotein (AFP)in escaping from the host immune surveillance of hepatocellular carcinoma.METHODS: AFP purified from human umbilical blood was administrated into the cultured human lymphoma Jurkat T cell line or hepatoma cell line, Bel7402 in vitro. The expression of tumor necrosis factor related apoptosisinducing ligand (TRAIL) and its receptor (TRAILR) mRNA were analyzed by Northern blot and Western blot wasused to detect the expression of Fas and Fas ligand (FasL)protein.RESULTS: AFP (20 mg/L) could promote the expression of FasL and TRAIL, and inhibit the expression of Fas and TRAILR of Bel7402 cells. For Jurkat cell line, AFP could suppress the expression of FasL and TRAIL, and stimulate the expression of Fas and TRAILR. AFP also could synergize with Bel7402 cells to inhibit the expression of FasL protein and TRAIL mRNA in Jurkat cells. The monoclonal antibody against AFP (anti-AFP) could abolish these functions of AFP.CONCLUSION: AFP is able to promote the expression of FasL and TRAIL in hepatoma cells and enhance the expression of Fas and TRAILR in lymphocytes. These could elicit the escape of hepatocellular carcinoma cells from the host's lymphocytes immune surveillance.

  7. Troy, a tumor necrosis factor receptor family member, interacts with Lgr5 to inhibit Wnt signaling in intestinal stem cells

    Czech Academy of Sciences Publication Activity Database

    Fafílek, Bohumil; Krausová, Michaela; Vojtěchová, Martina; Pospíchalová, Vendula; Tůmová, Lucie; Šloncová, Eva; Huranová, Martina; Stančíková, Jitka; Hlavatá, Adéla; Švec, Jiří; Sedláček, Radislav; Lukšan, O.; Olivierus, M.; Voska, L.; Jirsa, M.; Pačes, Jan; Kolář, Michal; Krivjanská, M.; Klimešová, Klára; Tlaskalová-Hogenová, Helena; Kořínek, Vladimír

    2013-01-01

    Roč. 144, č. 2 (2013), s. 381-391. ISSN 0016-5085 R&D Projects: GA MŠk 2B06077; GA ČR GAP305/11/1780; GA ČR(CZ) GAP304/11/1252; GA ČR(CZ) GD204/09/H058; GA ČR GAP305/10/2143; GA AV ČR KAN200520801 Grant ostatní: MŠMT(CZ) CZ 1.05/1.1.00/02.0109 Institutional support: RVO:68378050 ; RVO:61388971 Keywords : mouse model of colon cancer * β-catenin * TCF * Tnfrsf19 Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 13.926, year: 2013

  8. Activation of microglial cells triggers a release of brain-derived neurotrophic factor (BDNF inducing their proliferation in an adenosine A2A receptor-dependent manner: A2A receptor blockade prevents BDNF release and proliferation of microglia

    Directory of Open Access Journals (Sweden)

    Gomes Catarina

    2013-01-01

    Full Text Available Abstract Background Brain-derived neurotrophic factor (BDNF has been shown to control microglial responses in neuropathic pain. Since adenosine A2A receptors (A2ARs control neuroinflammation, as well as the production and function of BDNF, we tested to see if A2AR controls the microglia-dependent secretion of BDNF and the proliferation of microglial cells, a crucial event in neuroinflammation. Methods Murine N9 microglial cells were challenged with lipopolysaccharide (LPS, 100 ng/mL in the absence or in the presence of the A2AR antagonist, SCH58261 (50 nM, as well as other modulators of A2AR signaling. The BDNF cellular content and secretion were quantified by Western blotting and ELISA, A2AR density was probed by Western blotting and immunocytochemistry and cell proliferation was assessed by BrdU incorporation. Additionally, the A2AR modulation of LPS-driven cell proliferation was also tested in primary cultures of mouse microglia. Results LPS induced time-dependent changes of the intra- and extracellular levels of BDNF and increased microglial proliferation. The maximal LPS-induced BDNF release was time-coincident with an LPS-induced increase of the A2AR density. Notably, removing endogenous extracellular adenosine or blocking A2AR prevented the LPS-mediated increase of both BDNF secretion and proliferation, as well as exogenous BDNF-induced proliferation. Conclusions We conclude that A2AR activation plays a mandatory role controlling the release of BDNF from activated microglia, as well as the autocrine/paracrine proliferative role of BDNF.

  9. Functional erythropoietin receptors on human tumor cells

    International Nuclear Information System (INIS)

    Erythropoietin (EPO) is the principal regulator of red blood cell survival, growth and maturation and has achieved great clinical utility for the correction of anemia associated with renal failure, cancer and chemotherapy, and stem cell transplantation. EPO increasingly is being recognized as a pleiotrophic growth factor, having actions on nonhematopoietic cells as well. Both EPO and erythropoietin receptor (EPO-R) expression have been associated with cells of the endothelium, retina, central nervous system, gastrointestinal tract and female reproductive system. The role of EPO in these nonhematopoietic sites is not thoroughly understood and in some instances may be site-specific. Promotion of angiogenesis and blood vessel integrity, increased cell proliferation, prevention of apoptosis, and protection against ischemic damage in the presence of hypoxia have all been described as possible functions of EPO in one or more of these cell types. On the other hand, EPO-R also have been identified on a variety of tumor cells (while in some cases not on the adjacent normal tissue), and several reports have suggested a role for EPO in the direct stimulation of cancer cell growth in vivo and in vitro. Among those tumor cells on which we and others have identified functional EPO-R are breast and ovarian cancer cells. Additionally, the work presented here describes the first evidence that transformed prostate epithelial cells, prostate cancer cell lines, and both normal and cancerous prostate tissue express EPO-R. All of the EPO-R bearing prostate cell lines tested underwent a significant dose-dependent proliferative response to EPO, and EPO triggered intracellular signaling in the cells as evidenced by protein phosphorylation. The results implicate EPO in the biology of both normal and malignant prostate cells and suggest the need for careful evaluation of the use of recombinant EPO as a therapeutic agent in prostate cancer

  10. 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

    2013-03-01

    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

  11. Soluble forms of tumor necrosis factor receptors (TNF-Rs). The cDNA for the type I TNF-R, cloned using amino acid sequence data of its soluble form, encodes both the cell surface and a soluble form of the receptor

    DEFF Research Database (Denmark)

    Nophar, Y; Kemper, O; Brakebusch, C;

    1990-01-01

    Two proteins which specifically bind tumor necrosis factor (TNF) have recently been isolated from human urine in our laboratory. The two proteins cross-react immunologically with two species of cell surface TNF receptors (TNF-R). Antibodies against one of the two TNF binding proteins (TBPI) were...... that although this receptor can signal the phosphorylation of cellular proteins, it appears from its amino acid sequence to be devoid of intrinsic protein kinase activity. The extracellular domain of the receptor is composed of four internal cysteine-rich repeats, homologous to structures repeated four...

  12. Effects of Antisense Oligodeoxynucleotide to Follicle-stimulating Hormone Receptor on the Expression of Proliferating Cell Nuclear Antigen and Vascular Endothelial Growth Factor in Primary Culture Cells Derived from Human Ovarian Mucinous Cystadenocarcino

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The effects of antisense oligodeoxynucleotide (antisense ODN) to follicle-stimulating hormone receptor (FSHR) and follicle-stimulating hormone (FSH) on the expression of proliferating cell nuclear antigen (PCNA) and vascular endothelial growth factor (VEGF) were studied in primary culture cells derived from human ovarian mucinous cystadenocarcinoma (OMC). The prlmary OMC cells were cultured with the enzyme digestion method, and the expression of pan Keratin protein and FSHR mRNA was detected for identification of the cells. OMC cells were co-cultured with antisense ODN, nonsense ODN and FSH with different concentrations for 48 h and 72 h. The expression of PCNA and VEGF was detected by using SP immunohistochemistry. Compared with that in the control group, the PCNA and VEGF expression was increased obviously in FSH groups (P<0.05 or P< 0.01), while decreased significantly in antisense ODN groups (P<0. 05 or P<0.01) and unchanged in nonsense ODN groups, respectively. Meanwhile, antisense ODN could antagonize the increased expression of PCNA and VEGF caused by FSH significantly (P<0.01). It was suggested that FSH might promotethe development of OMC to some extent. Antisense ODN could inhibit the proliferative activity of OMC cells and the promoting proliferative activity enhanced by FSH.

  13. Angiotensin II-induced Akt activation through the epidermal growth factor receptor in vascular smooth muscle cells is mediated by phospholipid metabolites derived by activation of phospholipase D.

    Science.gov (United States)

    Li, Fang; Malik, Kafait U

    2005-03-01

    Angiotensin II (Ang II) activates cytosolic Ca(2+)-dependent phospholipase A(2) (cPLA(2)), phospholipase D (PLD), p38 mitogen-activated protein kinase (MAPK), epidermal growth factor receptor (EGFR) and Akt in vascular smooth muscle cells (VSMC). This study was conducted to investigate the relationship between Akt activation by Ang II and other signaling molecules in rat VSMC. Ang II-induced Akt phosphorylation was significantly reduced by the PLD inhibitor 1-butanol, but not by its inactive analog 2-butanol, and by brefeldin A, an inhibitor of the PLD cofactor ADP-ribosylation factor, and in cells infected with retrovirus containing PLD(2) siRNA or transfected with PLD(2) antisense but not control LacZ or sense oligonucleotide. Diacylglycerol kinase inhibitor II diminished Ang II-induced and diC8-phosphatidic acid (PA)-increased Akt phosphorylation, suggesting that PLD-dependent Akt activation is mediated by PA. Ang II-induced EGFR phosphorylation was inhibited by 1-butanol and PLD(2) siRNA and also by cPLA(2) siRNA. In addition, the inhibitor of arachidonic acid (AA) metabolism 5,8,11,14-eicosatetraynoic acid (ETYA) reduced both Ang II- and AA-induced EGFR transactivation. Furthermore, ETYA, cPLA(2) antisense, and cPLA(2) siRNA attenuated Ang II-elicited PLD activation. p38 MAPK inhibitor SB202190 [4-(4-flurophenyl)-2-(4-hydroxyphenyl)-5-(4-pyridyl)1H-imidazole] reduced PLD activity and EGFR and Akt phosphorylation elicited by Ang II. Pyrrolidine-1, a cPLA(2) inhibitor, and cPLA(2) siRNA decreased p38 MAPK activity. These data indicate that Ang II-stimulated Akt activity is mediated by cPLA(2)-dependent, p38 MAPK regulated PLD(2) activation and EGFR transactivation. We propose the following scheme of the sequence of events leading to activation of Akt in VSMC by Ang II: Ang II-->cPLA(2)-->AA-->p38 MAPK-->PLD(2)-->PA-->EGFR-->Akt. PMID:15525798

  14. Determination of the exact molecular requirements for type 1 angiotensin receptor epidermal growth factor receptor transactivation and cardiomyocyte hypertrophy.

    Science.gov (United States)

    Smith, Nicola J; Chan, Hsiu-Wen; Qian, Hongwei; Bourne, Allison M; Hannan, Katherine M; Warner, Fiona J; Ritchie, Rebecca H; Pearson, Richard B; Hannan, Ross D; Thomas, Walter G

    2011-05-01

    Major interest surrounds how angiotensin II triggers cardiac hypertrophy via epidermal growth factor receptor transactivation. G protein-mediated transduction, angiotensin type 1 receptor phosphorylation at tyrosine 319, and β-arrestin-dependent scaffolding have been suggested, yet the mechanism remains controversial. We examined these pathways in the most reductionist model of cardiomyocyte growth, neonatal ventricular cardiomyocytes. Analysis with [(32)P]-labeled cardiomyocytes, wild-type and [Y319A] angiotensin type 1 receptor immunoprecipitation and phosphorimaging, phosphopeptide analysis, and antiphosphotyrosine blotting provided no evidence for tyrosine phosphorylation at Y319 or indeed of the receptor, and mutation of Y319 (to A/F) did not prevent either epidermal growth factor receptor transactivation in COS-7 cells or cardiomyocyte hypertrophy. Instead, we demonstrate that transactivation and cardiomyocyte hypertrophy are completely abrogated by loss of G-protein coupling, whereas a constitutively active angiotensin type 1 receptor mutant was sufficient to trigger transactivation and growth in the absence of ligand. These results were supported by the failure of the β-arrestin-biased ligand SII angiotensin II to transactivate epidermal growth factor receptor or promote hypertrophy, whereas a β-arrestin-uncoupled receptor retained these properties. We also found angiotensin II-mediated cardiomyocyte hypertrophy to be attenuated by a disintegrin and metalloprotease inhibition. Thus, G-protein coupling, and not Y319 phosphorylation or β-arrestin scaffolding, is required for epidermal growth factor receptor transactivation and cardiomyocyte hypertrophy via the angiotensin type 1 receptor. PMID:21383310

  15. Expression of GABAergic receptors in mouse taste receptor cells.

    Directory of Open Access Journals (Sweden)

    Margaret R Starostik

    Full Text Available BACKGROUND: Multiple excitatory neurotransmitters have been identified in the mammalian taste transduction, with few studies focused on inhibitory neurotransmitters. Since the synthetic enzyme glutamate decarboxylase (GAD for gamma-aminobutyric acid (GABA is expressed in a subset of mouse taste cells, we hypothesized that other components of the GABA signaling pathway are likely expressed in this system. GABA signaling is initiated by the activation of either ionotropic receptors (GABA(A and GABA(C or metabotropic receptors (GABA(B while it is terminated by the re-uptake of GABA through transporters (GATs. METHODOLOGY/PRINCIPAL FINDINGS: Using reverse transcriptase-PCR (RT-PCR analysis, we investigated the expression of different GABA signaling molecules in the mouse taste system. Taste receptor cells (TRCs in the circumvallate papillae express multiple subunits of the GABA(A and GABA(B receptors as well as multiple GATs. Immunocytochemical analyses examined the distribution of the GABA machinery in the circumvallate papillae. Both GABA(A-and GABA(B- immunoreactivity were detected in the peripheral taste receptor cells. We also used transgenic mice that express green fluorescent protein (GFP in either the Type II taste cells, which can respond to bitter, sweet or umami taste stimuli, or in the Type III GAD67 expressing taste cells. Thus, we were able to identify that GABAergic receptors are expressed in some Type II and Type III taste cells. Mouse GAT4 labeling was concentrated in the cells surrounding the taste buds with a few positively labeled TRCs at the margins of the taste buds. CONCLUSIONS/SIGNIFICANCE: The presence of GABAergic receptors localized on Type II and Type III taste cells suggests that GABA is likely modulating evoked taste responses in the mouse taste bud.

  16. Src-Mediated Cross-Talk between Farnesoid X and Epidermal Growth Factor Receptors Inhibits Human Intestinal Cell Proliferation and Tumorigenesis

    OpenAIRE

    Zhongsheng Peng; Jean-Pierre Raufman; Guofeng Xie

    2012-01-01

    Besides its essential role in controlling bile acid and lipid metabolism, the farnesoid X receptor (FXR) protects against intestinal tumorigenesis by promoting apoptosis and inhibiting cell proliferation. However, the mechanisms underlying these anti-proliferative actions of FXR remain to be elucidated. In the present study, we examined the effects of FXR activation (FXR overexpression and treatment with an FXR agonist GW4064) and inactivation (treatment with FXR siRNA and an FXR antagonist g...

  17. Reduced expression of epidermal growth factor receptor related protein in gastric cancer

    OpenAIRE

    Moon, W. S.; Tarnawski, A S; Chai, J.; Yang, J. T.; Majumdar, A.P.N.

    2005-01-01

    Objectives: The recently cloned epidermal growth factor receptor related protein (ERRP) has been proposed to be a negative regulator of the epidermal growth factor receptor (EGFR). Because of the causal involvement of EGFR and its ligands in gastric cancer growth, we investigated expression of ERRP and cell proliferation in human gastric cancer.

  18. Activity Assay of Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitors in Triple-Negative Breast Cancer Cells Using Peptide-Conjugated Magnetic Beads

    OpenAIRE

    Ghosh, Gargi; Yan, Xiaoliang; Kron, Stephen J.; Palecek, Sean P.

    2013-01-01

    Triple-negative breast cancer (TNBC) is a highly aggressive subtype of breast cancer with limited treatment options. Epidermal growth factor receptor I (EGFR) has emerged as a promising target in TNBC. Limited success of the EGFR kinase inhibiting small molecules in clinical trials may be attributed in part to inaccuracy in identifying EGFR signatures in patient tumors. In light of the absence of a simple correlation between EGFR expression and its degree of activation, a simple and reliable ...

  19. Ligustrazine attenuates oxidative stress-induced activation of hepatic stellate cells by interrupting platelet-derived growth factorreceptor-mediated ERK and p38 pathways

    International Nuclear Information System (INIS)

    Hepatic fibrosis represents a frequent event following chronic insult to trigger wound healing reactions with accumulation of extracellular matrix (ECM) in the liver. Activation of hepatic stellate cells (HSCs) is the pivotal event during liver fibrogenesis. Compelling evidence indicates that oxidative stress is concomitant with liver fibrosis irrespective of the underlying etiology. Natural antioxidant ligustrazine exhibits potent antifibrotic activities, but the mechanisms are poorly understood. Our studies were to investigate the ligustrazine effects on HSC activation stimulated by hydrogen peroxide (H2O2), an in vitro model mimicking the oxidative stress in liver fibrogenesis, and to elucidate the possible mechanisms. Our results demonstrated that H2O2 at 5 μM significantly stimulated HSC proliferation and expression of marker genes of HSC activation; whereas ligustrazine dose-dependently suppressed proliferation and induced apoptosis in H2O2-activated HSCs, and attenuated expression of fibrotic marker genes. Mechanistic investigations revealed that ligustrazine reduced platelet-derived growth factorreceptor (PDGF-βR) expression and blocked the phosphorylation of extracellular regulated protein kinase (ERK) and p38 kinase, two downstream effectors of PDGF-βR. Further molecular evidence suggested that ligustrazine interruption of ERK and p38 pathways was dependent on the blockade of PDGF-βR and might be involved in ligustrazine reduction of fibrotic marker gene expression under H2O2 stimulation. Furthermore, ligustrazine modulated some proteins critical for HSC activation and ECM homeostasis in H2O2-stimulated HSCs. These data collectively indicated that ligustrazine could attenuate HSC activation caused by oxidative stress, providing novel insights into ligustrazine as a therapeutic option for hepatic fibrosis. Highlights: ► Ligustrazine inhibits oxidative stress-induced HSC activation. ► Ligustrazine reduces fibrotic marker genes in HSCs under

  20. Detection of Epidermal Growth Factor Receptor Mutations in Non-small Cell Lung Cancer Tumor Specimens from Various Ways by Denaturing High-performance Liquid Chromatography

    Directory of Open Access Journals (Sweden)

    Siyuan CHEN

    2010-09-01

    Full Text Available Background and objective Epidermal growth factor receptor (EGFR is the most important therapeutic target in non-small cell lung cancer (NSCLC. EGFR mutations may predict responsiveness to tyrosine kinase inhibitors (TKIs. These mutations are commonly identified using direct sequencing, which is considered the gold standard. But direct sequencing is time-consuming and hyposensitive. In addition, this method requires a lot of tumor specimens. Denaturing highperformance liquid chromatography (DHPLC is a rapid automated sensitive and specific method in mutant gene detection. The aim of this study is to evaluate DHPLC as a rapid detection method for EGFR mutations in NSCLC tumor specimens. Methods DHPLC was used to evaluate the accuracy and sensitivity of detection the serial dilutions of mutant and wild type EGFR plasma DNA. Frozen tumor specimens of 83 NSCLC patients from various ways had been included, after DNA extraction and polymerase chain reaction (PCR on EGFR exon 19 and 21, the results from the direct sequencing and DHPLC were compared. Results Mutant plasma DNA can be detected in the serial dilution of 1:100 by DHPLC and 1:10 by direct sequencing respectively. The results from DHPLC showed 22 EGFR mutations were detected in 83 NSCLC patients, and only 19 mutation samples had been conformed by direct sequencing. Moreover, the other 61 samples were deemed as wild type by DHPLC and direct sequencing. The sensitivity and specificity of DHPLC was 100% and 95.13% respectively. The detection of the tumor specimens from CT-guided transthoracic needle lung biopsy, lymph node biopsy and surgical resection all showed high sensitivity and specificity. EGFR mutation has strong correlation with gender and pathologic type, but irrelevant to age and smoking status. Conclusion DHPLC was a precise rapid preliminary screening method for detection of NSCLC EGFR genotype.

  1. Translational Research on Epidermal Growth Factor Receptor Gene Mutations in Targeted Therapy for Patients with Advanced Non-Small Cell Lung Cancer

    Institute of Scientific and Technical Information of China (English)

    WANG Xiao-yan; ZHOU Er-xi

    2015-01-01

    Objective:To explore the significance of epidermal growth factor receptor (EGFR) gene mutations in targeted therapy for patients with advanced non-small cell lung cancer (NSCLC). Methods:One hundred and seventeen patients with advanced NSCLC admitted in Maternal and Child Health Care Center of Zibo City from Jan., 2011 to Jan., 2014 were performed with EGFR gene detection and then divided into 3 groups according to the detecting results. Patients in group A and group B were given oral geiftinib, 250 mg/d while patients in Group C with docetaxel, 75 mg/m2. Chemotherapy for 3 groups was discontinued until severe adverse reactions or disease progression occurred, or continuous treatment was considered to be unfavorable by the doctors, or patients asked for withdrawal from the study. The relationship between clinicopathological features and EGFR mutations were analyzed. The short-term and long-term efifcacy and adverse reactions of 3 groups were observed. Results:Of the 31 cases with EGFR mutations, there were 16 cases (51.6%) of mutations in exon 19, 14 (45.2%) in exon 21 and 2 (6.45%) in exon 18. No EGFR mutation was found in exon 20. EGFR mutations were associated with histological types of tumors and whether patients were smoking. The median follow-up time was 26 months and 62 patients were dead. None of CR was in 3 groups. The disease control rate (DCR) in group A was obviously higher than that in group B (χ2=9.382,P=0.002), which was also higher in group C than that in group B (χ2=4.674,P=0.031). The 1-year survival rate in group A was obviously higher than that in group B and group C (P Conclusion:EGFR mutations are the main indicators for guiding the targeted therapy for patients with advanced NSCLC.

  2. Prospective Study of Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitors Concurrent With Individualized Radiotherapy for Patients With Locally Advanced or Metastatic Non-Small-Cell Lung Cancer

    International Nuclear Information System (INIS)

    Purpose: To establish the safety profile and efficacy of epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) concurrent with individualized radiotherapy (RT) in patients with locally advanced or metastatic non-small-cell lung cancer (NSCLC). Patients and Methods: Between June 2007 and January 2010, 26 patients with Stage III/IV NSCLC were enrolled in this prospective study. These patients were treated with EGFR-TKIs (gefitinib 250 mg or erlotinib 150 mg, oral daily) concurrent with individualized RT with curative intent. The thoracic RT plans were individually designed on the basis of tumor size and normal tissue volume constraints. All patients were assessed for toxicity, and 25 patients were available for efficacy. The primary endpoints were acute toxicity, overall survival, and median survival time. The secondary endpoints included local control rate, time to tumor progression, and progression-free survival (PFS). Results: Median gross tumor volume, mean lung dose, and lung V20 were 56 cm3, 8.6 Gy, and 14%, respectively. Median thoracic radiation dose was 70 Gy at a margin of gross tumor volume (range, 42-82 Gy), and median biological equivalent dose was 105 Gy (range, 60-119 Gy). Acute skin, hematologic, esophageal, and pulmonary toxicities were acceptable and manageable. Severe adverse events included neutropenia (Grade 4, 4%) and thrombocytopenia (Grade 4, 8%), esophagitis (Grade 3, 4%), and pneumonitis (Grade 3, 4%). With a median follow-up of 10.2 months, a local control rate of 96% was achieved for thoracic tumor. Median time to progression, median PFS, and median survival time were 6.3, 10.2, and 21.8 months, respectively. The 1- and 2-year PFS rates were both 42%, and 1-, 2-, and 3-year overall survival rates were 57%, 45%, and 30%, respectively. Conclusion: Concurrent EGFR-TKIs with individualized RT shows a favorable safety profile and promising outcome, therefore serving as a therapeutic option for patients with locally advanced or

  3. Oxytocin receptor ligands induce changes in cytoskeleton in neuroblastoma cells.

    Science.gov (United States)

    Bakos, Jan; Strbak, Vladimir; Paulikova, Helena; Krajnakova, Lucia; Lestanova, Zuzana; Bacova, Zuzana

    2013-07-01

    Aim of the present study was to evaluate effects of ligands of oxytocin receptors on gene expression of neurofilament proteins (nestin and microtubule-associated protein 2 (MAP2)) associated with neuronal differentiation and growth factors (brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF)) related to neuronal growth. Fluorescent staining of F-actin was used to observe morphology of cells. Co-treatment with oxytocin and oxytocin receptor antagonist--atosiban--resulted in significant increase of MAP2 gene expression in SK-N-SH cells. There was no effect of oxytocin on gene expression of growth factors BDNF and NGF. Surprisingly, oxytocin with atosiban significantly increased mRNA levels for both BDNF and NGF. Gene expression of vasopressin receptor (V1aR) significantly decreased in response to vasopressin. Atosiban decreased mRNA levels for oxytocin receptor (OXTR) and V1aR. Oxytocin significantly decreased OXTR and nestin mRNA levels and increased mRNA levels for BDNF and NGF in U-87 MG cells. The densest recruitment of F-actin filaments was observed in apical parts of filopodia in SK-N-SH cells incubated in oxytocin presence. Present data demonstrate complex role of ligands of oxytocin receptors in regulation of gene expression of intermediate filaments and thus, oxytocin might be considered as a growth factor in neuronal type of cells. PMID:23335033

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

    International Nuclear Information System (INIS)

    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

  5. Inhibition of multiple vascular endothelial growth factor receptors (VEGFR) blocks lymph node metastases but inhibition of VEGFR-2 is sufficient to sensitize tumor cells to platinum-based chemotherapeutics

    OpenAIRE

    Sini, Patrizia; Samarzija, Ivana; Baffert, Fabienne; Littlewood-Evans, Amanda; Schnell, Christian; Theuer, Andreas; Christian, Sven; Boos, Anja; Hess-Stumpp, Holger; Foekens, John; Setyono-Han, Buddy; Wood, Jeanette; Hynes, Nancy

    2008-01-01

    textabstractVascular endothelial growth factor receptors (VEGFR) have important roles in cancer, affecting blood and lymphatic vessel functionality as well as tumor cells themselves. We compared the efficacy of a VEGFR tyrosine kinase inhibitor, PTK787/ZK222584 (PTK/ZK), which targets the three VEGFRs, with blocking antibodies directed against VEGFR-2 (DC101) or VEGF-A (Pab85618) in a metastatic melanoma model. Although all inhibitors exerted comparable effects on primary tumor growth, only P...

  6. Suppression of insulin-like growth factor type I receptor by a triple-helix strategy inhibits IGF-I transcription and tumorigenic potential of rat C6 glioblastoma cells

    OpenAIRE

    Rininsland, Frauke; Johnson, Thomas R.; Chernicky, Cheryl L.; Schulze, Ekkehard; Burfeind, Peter; Ilan, Judith; Ilan, Joseph

    1997-01-01

    Homopurine (AG) and homopyrimidine (CT) oligodeoxyribonucleotides predicted to form triple-helical (triplex) structures have been shown to specifically suppress gene expression when supplied to cultured cells. Here we present evidence that homopurine RNA (effector) sequences designed to form a triplex with a homopurine⋅homopyrimidine sequence 3′ to the termination codon of the insulin-like growth factor type I receptor (IGF-IR) structural gene can efficiently suppress IGF-IR gene transcriptio...

  7. The role of the vascular endothelial growth factor/vascular endothelial growth factor receptors axis mediated angiogenesis in curcumin-loaded nanostructured lipid carriers induced human HepG2 cells apoptosis

    Directory of Open Access Journals (Sweden)

    Fengling Wang

    2015-01-01

    Full Text Available Background: Curcumin (diferuloylmethane, the active constituent of turmeric extract has potent anti-cancer properties have been demonstrated in hepatocellular carcinoma (HCC. However, its underlying molecular mechanism of therapeutic effects remains unclear. Vascular endothelial growth factor (VEGF and its receptors (VEGFRs have crucial roles in tumor angiogenesis. Purpose: The goal of this study was to investigate the role of the VEGF/VEGFRs mediated angiogenesis during the proliferation and apoptosis of human HepG2 hepatoma cell line and the effect of curcumin-loaded nanostructured lipid carriers (Cur-NLC. Materials and Methods: The proliferation of HepG2 cells was determined by methyl thiazolyl tetrazolium after exposure to Cur-NLC and native curcumin. Apoptosis was quantified by flow cytometry with annexin V-fluorescein isothiocyanate and propidium iodide staining. Cellular internalization of Cur-NLC was observed by fluorescent microscope. The level of VEGF was detected by enzyme-linked immunosorbent assay kits. The expression of VEGFRs was quantified by Western blotting. Results: Cur-NLC was more effective in inhibiting the proliferation and enhancing the apoptosis of HepG2 cells than native curcumin. Fluorescent microscope analysis showed that HepG2 cells internalized Cur-NLC more effectively than native curcumin. Furthermore, Cur-NLC down-regulated the level of VEGF and the expression of VEGFR-2, but had a slight effect on VEGFR-1. Conclusion: These results clearly demonstrated that Cur-NLC was more effective in anti-cancer activity than the free form of curcumin. These studies demonstrate for the 1 st time that Cur-NLC exerts an antitumor effect on HepG2 cells by modulating VEGF/VEGFRs signaling pathway.

  8. Human Neuroepithelial Cells Express NMDA Receptors

    Directory of Open Access Journals (Sweden)

    Cappell B

    2003-11-01

    Full Text Available Abstract L-glutamate, an excitatory neurotransmitter, binds to both ionotropic and metabotropic glutamate receptors. In certain parts of the brain the BBB contains two normally impermeable barriers: 1 cerebral endothelial barrier and 2 cerebral epithelial barrier. Human cerebral endothelial cells express NMDA receptors; however, to date, human cerebral epithelial cells (neuroepithelial cells have not been shown to express NMDA receptor message or protein. In this study, human hypothalamic sections were examined for NMDA receptors (NMDAR expression via immunohistochemistry and murine neuroepithelial cell line (V1 were examined for NMDAR via RT-PCR and Western analysis. We found that human cerebral epithelium express protein and cultured mouse neuroepithelial cells express both mRNA and protein for the NMDA receptor. These findings may have important consequences for neuroepithelial responses during excitotoxicity and in disease.

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

    International Nuclear Information System (INIS)

    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

  10. Research methods of interactions between cell factors and membrane receptors%细胞因子与膜受体蛋白相互作用的研究方法

    Institute of Scientific and Technical Information of China (English)

    李京敬; 毕引歌; 朱润芝; 兰天; 俞雁

    2011-01-01

    The interaction between cell factors and membrane receptor proteins plays an important role in life activities. Many diseases,such as cancers, autoimmune diseases and metabolic disorders have close relationship with the maladjustment of cell factors. So studying the interaction between cell factors and membrane receptors would be the groundwork for curing the diseases mentioned above. Here we reviewed the methods commonly used in nowadays studies, from directly detecting the combination of receptor and ligand by typical isotope labeling, to testing the downstream signal of biochemical channel, also to biophysical high-throughput testing.%细胞因子与膜受体的相互作用是生命活动中的重要环节.癌症、自身免疫疾病、代谢紊乱等疾病的发生都和细胞因子失调有着密切的关系,研究细胞因子和受体的相互作用成为治疗上述疾病的基石.本文综述了现今常用的研究方法,包括从最经典的同位素标记直接检测受体与配体的结合,到生化通路下游信号检测,再到生物物理高通量检测方法.

  11. Dependence of Wilms tumor cells on signaling through insulin-like growth factor 1 in an orthotopic xenograft model targetable by specific receptor inhibition

    DEFF Research Database (Denmark)

    Bielen, Aleksandra; Box, Gary; Perryman, Lara; Bjerke, Lynn; Popov, Sergey; Jamin, Yann; Jury, Alexa; Valenti, Melanie; Brandon, Alexis de Haven; Martins, Vanessa; Romanet, Vincent; Jeay, Sebastien; Raynaud, Florence I; Hofmann, Francesco; Robinson, Simon P; Eccles, Suzanne A; Jones, Chris

    2012-01-01

    We have previously demonstrated an increased DNA copy number and expression of IGF1R to be associated with poor outcome in Wilms tumors. We have now tested whether inhibiting this receptor may be a useful therapeutic strategy by using a panel of Wilms tumor cell lines. Both genetic and...... pharmacological targeting resulted in inhibition of downstream signaling through PI3 and MAP kinases, G(1) cell cycle arrest, and cell death, with drug efficacy dependent on the levels of phosphorylated IGF1R. These effects were further associated with specific gene expression signatures reflecting pathway...... inhibition, and conferred synergistic chemosensitisation to doxorubicin and topotecan. In the in vivo setting, s.c. xenografts of WiT49 cells resembled malignant rhabdoid tumors rather than Wilms tumors. Treatment with an IGF1R inhibitor (NVP-AEW541) showed no discernable antitumor activity and no downstream...

  12. Phase Ⅰ trial of icotinib, a novel epidermal growth factor receptor tyrosine kinase inhibitor, in Chinese patients with non-small cell lung cancer

    Institute of Scientific and Technical Information of China (English)

    WANG Han-ping; XIAO Yi; ZHANG Li; WANG Yin-xiang; TAN Fen-lai; XIA Ying; REN Guan-jun; HU Pei; JIANG Ji; WANG Meng-zhao

    2011-01-01

    Background The preclinical experiments and studies of congener drugs show icotinib, a new epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor, can specifically bind to the tyrosine kinase domain of the EGFR, block the EGFR related signal, thereby inhibit the growth of tumor cell. The objective of this study was to investigate the safety, tolerability and dose-related biologic effects of icotinib in patients with non-small cell lung cancer (NSCLC) in a Chinese patient population.Methods This was an open-label, phase Ⅰ, dose escalation, safety/tolerability trial of oral icotinib (100 to 400 mg), administered twice per day for 28-continuous-day cycles until disease progression or undue toxiclty.Results Forty patients with stage ⅢB (15%) or Ⅳ (85%) NSCLC were included in the study. They had mainly adenocarcinoma (85%), with a performance status (PS) of 0 (45%) or 1 (55%) and less than half the patients (45%) had histories of smoking and all were pretreated by at least one regimen of chemotherapy. Patients were assigned to three dose levels of 150 mg b.i.d, 200 mg b.i.d, or 125 mg t.i.d. The follow-up periods ranged from 5 to 80 weeks. Adverse events were found in 35% patients, most of which were mild and reversible. The adverse events mainly occurred in the first 4 weeks and included rash (25%), diarrhea, nausea and abdominal distention. One definite interstitial lung disease (ILD) was found in a patient in the dose of 200 mg b.i.d. According to an 8-week assessment, one (2.5%) patient receiving 150 mg gained complete response (CR) that persisted for 44 weeks, seven (17.50%) patients had partial remission (PR), and 18 (45%) patients had stable disease (SD). The objective response including CR+PR was 20%. The median time of progression-free survival for the 40 patients was 20 weeks (range: 12 to 32 weeks). The response was not affected by pathological type, history of smoking, or numbers of previous therapeutic regimens. No relationship between dose

  13. Hypoxia-inducible factor-1α increased the expression of peroxisome proliferator activated receptor α in lung cancer cell A549

    Institute of Scientific and Technical Information of China (English)

    张惠兰; 张珍祥; 徐永健

    2004-01-01

    @@ Hypoxia plays a fundamental role in many pathologic processes. Hypoxia-inducible factor-1 (HIF-1) is a heterodimeric basic helix-loop-helix-per-aryl hydrocarbon receptor ARNT-sim (PAS) domain protein, consisting of α and β subunits and is precisely regulated by cellular oxygen levels.1 The peroxisome proliferator-activated receptors (PPARs) are family nuclear hormone-binding proteins with increasing diverse functions as transcriptional regulators, owning three subtypes (α, β, and γ).2 PPARα plays a critical physiological role as lipid sensors and regulators of proliferation.3 Hypoxia can elicit up-regulation of PPAR-α expression.4 Herein, we report the results of an investigation on the correlation of HIF-1α and PPARα.

  14. CD44 function as a growth factor co-receptor

    Energy Technology Data Exchange (ETDEWEB)

    Chen, L.

    2003-06-01

    CD44 splice variant proteins containing exon v6 encoded sequence have been implicated in tumour metastasis. The work presented in this thesis shows that CD44 isoforms containing exon v6 encoded sequences act as coreceptor for the c-Met receptor, a tyrosine kinase receptor that is involved in growth control and invasive growth. The c-Met receptor and its ligand hepatocyte growth factor (HGF) have also been implicated in tumour metastasis. My results show the cooperation between CD44, HGF and c-Met. A CD44 isoform containing variant exon v6 encoded sequences is strictly required for c-Met activation by HGF/SF in rat and human carcinoma cells. In a non-metastatic cell line BSp73AS cells which only expressed CD44 standard form, HGF can not activate c-Met. Upon transfection with the CD44 bearing v6 encoded sequences, the cells become HGF inducible. Antibodies against two CD44 exon v6-encoded epitopes inhibit autophosphorylation of c-Met. The CD44 isoform is required for the assembly of signalling complex containing at least HGF, c-Met and CD44 v6 bearing isoform. Furthermore, this growth factor co-receptor function could be a more general mechanism. I have investigated the involvement of CD44 isoforms in the signalling by the EGF receptor family. My results show that HB-EGF, EGF and Amphiregulin activate their receptors in a CD44 dependent manner. CD44 v6 specific antibodies can interfere with HB-EGF, EGF and Amphiregulin signalling both at Erk level and at receptor level. (orig.) [German] In der nicht metastasierenden Zelllinie Bsp73 AS, die ausschliesslich die CD44 Standardform exprimiert, fuehrt HGF nicht zur Aktivierung von c-Met. Durch Transfektion mit unterschiedlichen CD44 v6 enthaltenden Isoformen, werden die Zellen HGF-induzierbar. Antikoerper gegen zwei von CD44 Exon v6 kodierte Epitope verhindern die Autophosphorylierung von c-Met. Die CD44 Isoform wird zur Bildung eines Signalkomplexes benoetigt, der zumindest HGF, c-Met und CD44v6 tragende Isoformen

  15. Functional and Physical Interactions among Saccharomyces cerevisiae α-Factor Receptors

    OpenAIRE

    Gehret, Austin U.; Connelly, Sara M.; Dumont, Mark E.

    2012-01-01

    The α-factor receptor Ste2p is a G protein-coupled receptor (GPCR) expressed on the surface of MATa haploid cells of the yeast Saccharomyces cerevisiae. Binding of α-factor to Ste2p results in activation of a heterotrimeric G protein and of the pheromone response pathway. Functional interactions between α-factor receptors, such as dominant-negative effects and recessive behavior of constitutive and hypersensitive mutant receptors, have been reported previously. We show here that dominant-nega...

  16. Activation of microglial cells triggers a release of brain-derived neurotrophic factor (BDNF) inducing their proliferation in an adenosine A2A receptor-dependent manner: A2A receptor blockade prevents BDNF release and proliferation of microglia

    OpenAIRE

    Gomes Catarina; Ferreira Raquel; George Jimmy; Sanches Rui; Rodrigues Diana I; Gonçalves Nélio; Cunha Rodrigo A

    2013-01-01

    Abstract Background Brain-derived neurotrophic factor (BDNF) has been shown to control microglial responses in neuropathic pain. Since adenosine A2A receptors (A2ARs) control neuroinflammation, as well as the production and function of BDNF, we tested to see if A2AR controls the microglia-dependent secretion of BDNF and the proliferation of microglial cells, a crucial event in neuroinflammation. Methods Murine N9 microglial cells were challenged with lipopolysaccharide (LPS, 100 ng/mL) in the...

  17. Profiling epidermal growth factor receptor and heregulin receptor 3 heteromerization using receptor tyrosine kinase heteromer investigation technology.

    Directory of Open Access Journals (Sweden)

    Mohammed Akli Ayoub

    Full Text Available Heteromerization can play an important role in regulating the activation and/or signal transduction of most forms of receptors, including receptor tyrosine kinases (RTKs. The study of receptor heteromerization has evolved extensively with the emergence of resonance energy transfer based approaches such as bioluminescence resonance energy transfer (BRET. Here, we report an adaptation of our Receptor-Heteromer Investigation Technology (Receptor-HIT that has recently been published as the G protein-coupled receptor (GPCR Heteromer Identification Technology (GPCR-HIT. We now demonstrate the utility of this approach for investigating RTK heteromerization by examining the functional interaction between the epidermal growth factor (EGF receptor (EGFR; also known as erbB1/HER1 and heregulin (HRG receptor 3 (HER3; also known as erbB3 in live HEK293FT cells using recruitment of growth factor receptor-bound protein 2 (Grb2 to the activated receptors. We found that EGFR and HER3 heteromerize specifically as demonstrated by HRG inducing a BRET signal between EGFR/Rluc8 and Grb2/Venus only when HER3 was co-expressed. Similarly, EGF stimulation promoted a specific BRET signal between HER3/Rluc8 and Grb2/Venus only when EGFR was co-expressed. Both EGF and HRG effects on Grb2 interaction are dose-dependent, and specifically blocked by EGFR inhibitor AG-1478. Furthermore, truncation of HER3 to remove the putative Grb2 binding sites appears to abolish EGF-induced Grb2 recruitment to the EGFR-HER3 heteromer. Our results support the concept that EGFR interacts with Grb2 in both constitutive and EGF-dependent manners and this interaction is independent of HER3 co-expression. In contrast, HER3-Grb2 interaction requires the heteromerization between EGFR and HER3. These findings clearly indicate the importance of EGFR-HER3 heteromerization in HER3-mediated Grb2-dependent signaling pathways and supports the central role of HER3 in the diversity and regulation of HER

  18. Soy isoflavones increase quinone reductase in hepa-1c1c7 cells via estrogen receptor beta and nuclear factor erythroid 2-related factor 2 binding to the antioxidant response element.

    Science.gov (United States)

    Froyen, Erik B; Steinberg, Francene M

    2011-09-01

    Soy protein and isoflavones (genistein and daidzein) have been demonstrated to increase quinone reductase (QR) activity, protein, and mRNA in animal and cell culture models. However, their mechanism of action has not been completely characterized. Additionally, it has not been determined if equol, a daidzein metabolite, can modulate QR activity and expression. Estrogen receptor beta (ERβ) is thought to be involved in stimulating QR gene transcription by anti-estrogens and phytoestrogens, along with nuclear factor erythroid 2-related factor 2 (Nrf2). This study tested the hypothesis that genistein, daidzein and equol increase quinone reductase activity, protein and mRNA via ERβ and Nrf2 binding to the QR antioxidant response element (ARE). QR expression and activity were determined using TaqMan polymerase chain reaction, protein immunoblots and activity assays. Molecular events were investigated using luciferase reporter gene assays and chromatin immunoprecipitation (ChIP). Hepa-1c1c7 cells were treated with control [0.1% (v:v) dimethyl sulfoxide (DMSO)]; 1 μmol/L β-naphthoflavone (positive control); 5 μmol/L resveratrol (ChIP positive control for ERβ binding) and 1, 5 and 25 μmol/L genistein, daidzein or equol. Treatment durations were 1 h (ChIP), 24 h (mRNA and luciferase assays) and 24 and 48 h (protein and activity). Genistein, daidzein and equol increased QR activity, protein and mRNA, with daidzein and equol having more of an impact at physiologic concentrations (1 and 5 μmol/L) compared to genistein. Furthermore, the study results demonstrate that genistein, daidzein and equol interact with the QR ARE and that daidzein and equol act via both ERβ and Nrf2 binding strongly to the QR ARE. PMID:21167702

  19. Chemokine receptor expression by mast cells.

    Science.gov (United States)

    Juremalm, Mikael; Nilsson, Gunnar

    2005-01-01

    There is a growing interest in the role of chemokines and their receptors in the determination of mast cell tissue localization and how chemokines regulate mast cell function. At least nine chemokine receptors (CXCR1, CXCR2, CXCR3, CXCR4, CX3CR1, CCR1, CCR3, CCR4 and CCR5) have been described to be expressed by human mast cells of different origins. Seven chemokines (CXCL1, CXCL5, CXCL8, CXCL14, CX3CL1, CCL5 and CCL11) have been shown to act on some of these receptors and to induce mast cell migration. Mast cells have a unique expression pattern of CCR3, CXCR1 and CXCR2. These receptors are mainly expressed intracellularly on cytoplasmic membranes. Upon an allergic activation, CCR3 expression is increased on the cell surface and the cell becomes vulnerable for CCL11 treatment. Chemokines do not induce mast cell degranulation but CXCL14 causes secretion of de novo synthesized CXCL8. Because of the expression of CCR3, CCR5 and CXCR4 on mast cell progenitors, these cells are susceptible to HIV infection and mast cells might therefore be a persistent HIV reservoir in AIDS. In this review, we summarize the knowledge about chemokine receptor expression and function on mast cells. PMID:16107768

  20. Systemic CD8+ T cell-mediated tumoricidal effects by intratumoral treatment of oncolytic herpes simplex virus with the agonistic monoclonal antibody for murine glucocorticoid-induced tumor necrosis factor receptor.

    Directory of Open Access Journals (Sweden)

    Mikiya Ishihara

    Full Text Available Oncolytic virotherapy combined with immunomodulators is a novel noninvasive strategy for cancer treatment. In this study, we examined the tumoricidal effects of oncolytic HF10, a naturally occurring mutant of herpes simplex virus type-1, combined with an agonistic DTA-1 monoclonal antibody specific for the glucocorticoid-induced tumor necrosis factor receptor. Two murine tumor models were used to evaluate the therapeutic efficacies of HF10 virotherapy combined with DTA-1. The kinetics and immunological mechanisms of DTA-1 in HF10 infection were examined using flow cytometry and immunohistochemistry. Intratumoral administration of HF10 in combination with DTA-1 at a low dose resulted in a more vigorous attenuation of growth of the untreated contralateral as well as the treated tumors than treatment with either HF10 or DTA-1 alone. An accumulation of CD8(+ T cells, including tumor- and herpes simplex virus type-1-specific populations, and a decrease in the number of CD4(+ Foxp3(+ T regulatory cells were seen in both HF10- and DTA-1-treated tumors. Studies using Fc-digested DTA-1 and Fcγ receptor knockout mice demonstrated the direct participation of DTA-1 in regulatory T cell depletion by antibody-dependent cellular cytotoxicity primarily via macrophages. These results indicated the potential therapeutic efficacy of a glucocorticoid-induced tumor necrosis factor receptor-specific monoclonal antibody in oncolytic virotherapy at local tumor sites.

  1. Bioprocess development for the production of mouse-human chimeric anti-epidermal growth factor receptor vIII antibody C12 by suspension culture of recombinant Chinese hamster ovary cells

    OpenAIRE

    Hu, Suwen; Deng, Lei; Wang, Huamao; Zhuang, Yingping; Chu, Ju; Zhang, Siliang; Li, Zhonghai; Guo, Meijin

    2011-01-01

    The mouse-human chimeric anti-epidermal growth factor receptor vIII (EGFRvIII) antibody C12 is a promising candidate for the diagnosis of hepatocellular carcinoma (HCC). In this study, 3 processes were successfully developed to produce C12 by cultivation of recombinant Chinese hamster ovary (CHO-DG44) cells in serum-free medium. The effect of inoculum density was evaluated in batch cultures of shaker flasks to obtain the optimal inoculum density of 5 × 105 cells/mL. Then, the basic metabolic ...

  2. ZD6474, an inhibitor of vascular endothelial growth factor receptor tyrosine kinase, inhibits growth of experimental lung metastasis and production of malignant pleural effusions in a non-small cell lung cancer model.

    Science.gov (United States)

    Matsumori, Yuka; Yano, Seiji; Goto, Hisatsugu; Nakataki, Emiko; Wedge, Stephen R; Ryan, Anderson J; Sone, Saburo

    2006-01-01

    ZD6474 is a novel, orally active inhibitor of vascular endothelial growth factor receptor-2 (VEGFR-2) tyrosine kinase, with some additional activity against epidermal growth factor receptor (EGFR) tyrosine kinase. The purpose of this study was to determine the potential of ZD6474 in the control of established experimental lung metastasis and pleural effusions produced by human non-small cell lung cancer (NSCLC) cells. PC14PE6 (adenocarcinoma) and H226 (squamous cell carcinoma) cells express high levels of EGFR and only PC14PE6 cells overexpress VEGF. Neither ZD6474 nor the EGFR tyrosine kinase inhibitor gefitinib inhibit proliferation of PC14PE6 or H226 cells in vitro. Both PC14PE6 and H226 cells inoculated intravenously into nude mice induced multiple lung nodules after 5-7 weeks. In addition, PC14PE6 cells produced bloody pleural effusions. Daily oral treatment with ZD6474 did not reduce the number of lung nodules produced by PC14PE6 or H226 cells, but did reduce the lung weight and the size of lung nodules. ZD6474 also inhibited the production of pleural effusions by PC14PE6 cells. Histological analyses of lung lesions revealed that ZD6474 treatment inhibited activation of VEGFR-2 and reduced tumor vascularization and tumor cell proliferation. Therapeutic effects of ZD6474 were considered likely to be due to inhibition of VEGFR-2 tyrosine kinase because gefitinib was inactive in this model. These results indicate that ZD6474, an inhibitor of VEGFR-2, may be useful in controlling the growth of established lung metastasis and pleural effusions by NSCLC. PMID:16783964

  3. Lung-Derived Factors Mediate Breast Cancer Cell Migration through CD44 Receptor-Ligand Interactions in a Novel Ex Vivo System for Analysis of Organ-Specific Soluble Proteins

    Directory of Open Access Journals (Sweden)

    Jenny E. Chu

    2014-02-01

    Full Text Available Breast cancer preferentially metastasizes to lung, lymph node, liver, bone, and brain. However, it is unclear whether properties of cancer cells, properties of organmicroenvironments, or a combination of both is responsible for this observed organ tropism. We hypothesized that breast cancer cells exhibit distinctive migration/growth patterns in organ microenvironments that mirror common clinical sites of breast cancer metastasis and that receptor-ligand interactions between breast cancer cells and soluble organ-derived factors mediate this behavior. Using an ex vivo model system composed of organ-conditionedmedia (CM, human breast cancer cells (MDA-MB-231,MDA-MB-468, SUM149, and SUM159 displayed cell line—specific and organ-specific patterns of migration/proliferation that corresponded to their in vivo metastatic behavior. Notably, exposure to lung-CM increased migration of all cell lines and increased proliferation in two of four lines (P < .05. Several cluster of differentiation (CD 44 ligands including osteopontin (OPN and L-selectin (SELL were identified in lung-CM by protein arrays. Immunodepletion of SELL decreased migration of MDA-MB-231 cells, whereas depletion of OPN decreased both migration and proliferation. Pretreatment of cells with a CD44-blocking antibody abrogated migration effects (P < .05. “Stemlike” breast cancer cells with high aldehyde dehydrogenase and CD44 (ALDHhiCD44+ responded in a distinct chemotacticmanner toward organ-CM, preferentially migrating toward lung-CM through CD44 receptor-ligand interactions (P < .05. In contrast, organ-specific changes in migration were not observed for ALDHlowCD44- cells. Our data suggest that interactions between CD44+ breast cancer cells and soluble factors present in the lung microenvironment may play an important role in determining organotropic metastatic behavior.

  4. Ligustrazine attenuates oxidative stress-induced activation of hepatic stellate cells by interrupting platelet-derived growth factorreceptor-mediated ERK and p38 pathways

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Feng [Department of Clinical Pharmacy, College of Pharmacy, Nanjing University of Chinese Medicine, Nanjing 210029 (China); Ni, Chunyan [Department of Clinical Pharmacy, College of Pharmacy, Nanjing University of Chinese Medicine, Nanjing 210029 (China); The First People' s Hospital of Changzhou, Changzhou 213003 (China); Kong, Desong; Zhang, Xiaoping; Zhu, Xiaojing; Chen, Li [Department of Clinical Pharmacy, College of Pharmacy, Nanjing University of Chinese Medicine, Nanjing 210029 (China); Lu, Yin [Department of Clinical Pharmacy, College of Pharmacy, Nanjing University of Chinese Medicine, Nanjing 210029 (China); Jiangsu Key Laboratory for Pharmacology and Safety Evaluation of Chinese Materia Medica, Nanjing University of Chinese Medicine, Nanjing 210046 (China); National First-Class Key Discipline for Traditional Chinese Medicine of Nanjing University of Chinese Medicine, Nanjing 210046 (China); Zheng, Shizhong, E-mail: nytws@163.com [Department of Clinical Pharmacy, College of Pharmacy, Nanjing University of Chinese Medicine, Nanjing 210029 (China); Jiangsu Key Laboratory for Pharmacology and Safety Evaluation of Chinese Materia Medica, Nanjing University of Chinese Medicine, Nanjing 210046 (China); National First-Class Key Discipline for Traditional Chinese Medicine of Nanjing University of Chinese Medicine, Nanjing 210046 (China)

    2012-11-15

    Hepatic fibrosis represents a frequent event following chronic insult to trigger wound healing reactions with accumulation of extracellular matrix (ECM) in the liver. Activation of hepatic stellate cells (HSCs) is the pivotal event during liver fibrogenesis. Compelling evidence indicates that oxidative stress is concomitant with liver fibrosis irrespective of the underlying etiology. Natural antioxidant ligustrazine exhibits potent antifibrotic activities, but the mechanisms are poorly understood. Our studies were to investigate the ligustrazine effects on HSC activation stimulated by hydrogen peroxide (H{sub 2}O{sub 2}), an in vitro model mimicking the oxidative stress in liver fibrogenesis, and to elucidate the possible mechanisms. Our results demonstrated that H{sub 2}O{sub 2} at 5 μM significantly stimulated HSC proliferation and expression of marker genes of HSC activation; whereas ligustrazine dose-dependently suppressed proliferation and induced apoptosis in H{sub 2}O{sub 2}-activated HSCs, and attenuated expression of fibrotic marker genes. Mechanistic investigations revealed that ligustrazine reduced platelet-derived growth factorreceptor (PDGF-βR) expression and blocked the phosphorylation of extracellular regulated protein kinase (ERK) and p38 kinase, two downstream effectors of PDGF-βR. Further molecular evidence suggested that ligustrazine interruption of ERK and p38 pathways was dependent on the blockade of PDGF-βR and might be involved in ligustrazine reduction of fibrotic marker gene expression under H{sub 2}O{sub 2} stimulation. Furthermore, ligustrazine modulated some proteins critical for HSC activation and ECM homeostasis in H{sub 2}O{sub 2}-stimulated HSCs. These data collectively indicated that ligustrazine could attenuate HSC activation caused by oxidative stress, providing novel insights into ligustrazine as a therapeutic option for hepatic fibrosis. Highlights: ► Ligustrazine inhibits oxidative stress-induced HSC activation.

  5. Plasma fibrinogen levels are associated with epidermal growth factor receptor gene mutation in Chinese patients with non-small cell lung cancer

    Institute of Scientific and Technical Information of China (English)

    Jianfei Zhu; Ling Cai; Haoxian Yang; Yinsheng Wen; Junye Wang; Tiehua Rong; Lanjun Zhang

    2013-01-01

    Objective: The plasma fibrinogen levels had not only been used as an independent prognostic parameter for thepatients with non-small cell lung cancer (NSCLC), but also as a promising biomarker for evaluating the efficacy of chemotherapy. This study aimed to investigate the correlation between the plasma fibrinogen levels and epidermal growth factor receptor (EGFR) gene mutation and clinical-pathological characteristics of Chinese patients with NSCLC. Methods: In this retrospective study, NSCLC specimens collected from 352 patients between November 2009 and November 2011 were selected to detect EGFR gene mutation with real-time polymerase chain reaction (RT-PCR). In these specimens, 308 ones were also detected EGFR gene copy number with fluorescence in situ hybridization (FISH). Coagulation makers were examined prior to the operations. The association between the plasma fibrinogen levels and EGFR gene mutation and clinical-pathological characteristics were analyzed using SPSS 16.0 software. Results: The median pre-operation plasma fibrinogen level was 3.55 g/L (109/352) patients with higher plasma fibrinogen level (> 4.0 g/L). The lower plasma fibrinogen levels correlated significantly with EGFR gene mutations (P < 0.001), the similar result was seen in platelet counts (P = 0.026). A linear correlation was found between the plasma fibrinogen levels and the platelet counts in NSCLC patients (R2 = 0.209, P < 0.001). Pre-operationplasma fibrinogen levels correlated with gender (P < 0.001), smoking status (P < 0.001), and histology (P < 0.001). There weresignificant link between the above clinical-pathological characteristics and EGFR gene mutations. In addition, EGFR gene mutationwas correlated with FISH-positive status (P < 0.001). Moreover, both plasma fibrinogen level (P = 0.024) and the EGFRgene copy number (P = 0.040) had significant relationships with the pathological TNM stage. Conclusion: This study showedthat a significant relevance between plasma fibrinogen

  6. Translational Research on Epidermal Growth Factor Receptor Gene Mutations in Targeted Therapy for Patients with Advanced Non-Small Cell Lung Cancer

    Directory of Open Access Journals (Sweden)

    Xiao-yan WANG

    2015-12-01

    Full Text Available Abstract Objective: To explore the significance of epidermal growth factor receptor (EGFR gene mutations in targeted therapy for patients with advanced non-small cell lung cancer (NSCLC. Methods: One hundred and seventeen patients with advanced NSCLC admitted in Maternal and Child Health Care Center of Zibo City from Jan., 2011 to Jan., 2014 were performed with EGFR gene detection and then divided into 3 groups according to the detecting results. Patients in group A and group B were given oral gefitinib, 250 mg/d while patients in Group C with docetaxel, 75 mg/m2. Chemotherapy for 3 groups was discontinued until severe adverse reactions or disease progression occurred, or continuous treatment was considered to be unfavorable by the doctors, or patients asked for withdrawal from the study. The relationship between clinicopathological features and EGFR mutations were analyzed. The short-term and long-term efficacy and adverse drug reactions of 3 groups were observed. Results: Of the 31 cases with EGFR mutations, there were 16 cases (51.6% of mutations in exon 19, 14 (45.2% in exon 21 and 2 (6.45% in exon 18. No EGFR mutation was found in exon 20. EGFR mutations were associated with histological types of tumors and whether patients were smoking. The median follow-up time was 26 months and 62 patients were dead. None of CR was in 3 groups. The disease control rate (DCR in Group A was obviously higher than that in Group B ( χ 2 =9.382, P=0.002, which was also higher in Group C than that in Group B ( χ 2 =4.674, P=0.031. The 1-year survival rate in Group A was obviously higher than that in group B and group C ( P <0.05, or P<0.01 , which was prominently higher in Group C than that in Group B ( P <0.01 . The median progression-free survival (PFS and median overall survival (OS were the longest in Group A was and the shortest in Group B. The adverse reactions of two kinds of

  7. Effects of luteolin and quercetin, inhibitors of tyrosine kinase, on cell growth and metastasis-associated properties in A431 cells overexpressing epidermal growth factor receptor

    OpenAIRE

    Huang, Y.-T.; Hwang, J -J; Lee, P -P; Ke, F -C; Huang, J. -H.; Huang, C.-J.; Kandaswami, C; Middleton, E.; Lee, M -T

    1999-01-01

    Flavonoids display a wide range of pharmacological properties including anti-inflammatory. Anti-mutagenic, anti-carcinogenic and anti-cancer effects. Here, we evaluated the effects of eight flavonoids on the tumour cell proliferation, cellular protein phosphorylation, and matrix metalloproteinase (MMPs) secretion.Of the flavonoids examined, luteolin (Lu) and quercetin (Qu) were the two most potent agents, and significantly inhibited A431 cell proliferation with IC50 values of 19 and 21 μM, re...

  8. Therapy for acute pancreatitis with platelet-activating factor receptor antagonists

    OpenAIRE

    Chen, Chong; Xia, Shi-hai; Chen, Hong; Li, Xiao-Hong

    2008-01-01

    Acute pancreatitis (AP) causes release of platelet-activating factor (PAF), which induces systemic effects that contribute to circulatory disturbances and multiple organ failure. PAF is a cell surface secretion of bioactive lipid, which could produce physiological and pathological effects by binding to its cell surface receptor called platelet-activating factor receptor (PAF-R). Studies showed that PAF participates in the occurrence and development of AP and administration of platelet-activat...

  9. Epidermal growth factor receptor and KRAS mutations in Brazilian lung cancer patients

    OpenAIRE

    Bacchi, Carlos E.; Heloísa Ciol; Queiroga, Eduardo M.; Benine, Lucimara C.; Silva, Luciana H.; Ojopi, Elida B.

    2012-01-01

    OBJECTIVE: Epidermal growth factor receptor is involved in the pathogenesis of non-small cell lung cancer and has recently emerged as an important target for molecular therapeutics. The KRAS oncogene also plays an important role in the development of lung cancer. The aim of this study was to evaluate the frequency of epidermal growth factor receptor and KRAS mutations in a population of Brazilian patients with non-small cell lung cancer. METHODS: A total of 207 specimens from Brazilian patien...

  10. Epidermal Growth Factor Receptor in Prostate Cancer Derived Exosomes.

    Directory of Open Access Journals (Sweden)

    Geetanjali Kharmate

    Full Text Available Exosomes proteins and microRNAs have gained much attention as diagnostic tools and biomarker potential in various malignancies including prostate cancer (PCa. However, the role of exosomes and membrane-associated receptors, particularly epidermal growth factor receptor (EGFR as mediators of cell proliferation and invasion in PCa progression remains unexplored. EGFR is frequently overexpressed and has been associated with aggressive forms of PCa. While PCa cells and tissues express EGFR, it is unknown whether exosomes derived from PCa cells or PCa patient serum contains EGFR. The aim of this study was to detect and characterize EGFR in exosomes derived from PCa cells, LNCaP xenograft and PCa patient serum. Exosomes were isolated from conditioned media of different PCa cell lines; LNCaP xenograft serum as well as patient plasma/serum by differential centrifugation and ultracentrifugation on a sucrose density gradient. Exosomes were confirmed by electron microscopy, expression of exosomal markers and NanoSight™ analysis. EGFR expression was determined by western blot analysis and ELISA. This study demonstrates that exosomes may easily be derived from PCa cell lines, serum obtained from PCa xenograft bearing mice and clinical samples derived from PCa patients. Presence of exosomal EGFR in PCa patient exosomes may present a novel approach for measuring of the disease state. Our work will allow to build on this finding for future understanding of PCa exosomes and their potential role in PCa progression and as minimal invasive biomarkers for PCa.

  11. Small molecule receptor tyrosine kinase inhibitor of platelet-derived growth factor signaling (SU9518) modifies radiation response in fibroblasts and endothelial cells

    International Nuclear Information System (INIS)

    Several small receptor tyrosine kinase inhibitors (RTKI) have entered clinical cancer trials alone and in combination with radiotherapy or chemotherapy. The inhibitory spectrum of these compounds is often not restricted to a single target. For example Imatinib/Gleevec (primarily a bcr/abl kinase inhibitor) or SU11248 (mainly a VEGFR inhibitor) are also potent inhibitors of PDGFR and other kinases. We showed previously that PDGF signaling inhibition attenuates radiation-induced lung fibrosis in a mouse model. Here we investigate effects of SU9518, a PDGFR inhibitor combined with ionizing radiation in human primary fibroblasts and endothelial cells in vitro, with a view on utilizing RTKI for antifibrotic therapy. Protein levels of PDGFR-α/-β and phosphorylated PDGFR in fibroblasts were analyzed using western and immunocytochemistry assays. Functional proliferation and clonogenic assays were performed (i) to assess PDGFR-mediated survival and proliferation in fibroblasts and endothelial cells after SU9518 (small molecule inhibitor of PDGF receptor tyrosine kinase); (ii) to test the potency und selectivity of the PDGF RTK inhibitor after stimulation with PDGF isoforms (-AB, -AA, -BB) and VEGF+bFGF. In order to simulate in vivo conditions and to understand the role of radiation-induced paracrine PDGF secretion, co-culture models consisting of fibroblasts and endothelial cells were employed. In fibroblasts, radiation markedly activated PDGF signaling as detected by enhanced PDGFR phosphorylation which was potently inhibited by SU9518. In fibroblast clonogenic assay, SU9518 reduced PDGF stimulated fibroblast survival by 57%. Likewise, SU9518 potently inhibited fibroblast and endothelial cell proliferation. In the co-culture model, radiation of endothelial cells and fibroblast cells substantially stimulated proliferation of non irradiated fibroblasts and vice versa. Importantly, the RTK inhibitor significantly inhibited this paracrine radiation-induced fibroblast and

  12. Src-mediated cross-talk between farnesoid X and epidermal growth factor receptors inhibits human intestinal cell proliferation and tumorigenesis.

    Directory of Open Access Journals (Sweden)

    Zhongsheng Peng

    Full Text Available Besides its essential role in controlling bile acid and lipid metabolism, the farnesoid X receptor (FXR protects against intestinal tumorigenesis by promoting apoptosis and inhibiting cell proliferation. However, the mechanisms underlying these anti-proliferative actions of FXR remain to be elucidated. In the present study, we examined the effects of FXR activation (FXR overexpression and treatment with an FXR agonist GW4064 and inactivation (treatment with FXR siRNA and an FXR antagonist guggulsterone on colon cancer cell proliferation in vitro using human colon cancer cell lines (H508, SNU-C4 and HT-29 and in vivo using xenografts in nude mice. Blocking FXR activity with guggulsterone stimulated time- and dose-dependent EGFR (Tyr845 phosphorylation and ERK activation. In contrast, FXR overexpression and activation with GW4064 attenuated cell proliferation by down-regulating EGFR (Tyr845 phosphorylation and ERK activation. Treatment with guggulsterone and GW4064 also caused dose-dependent changes in Src (Tyr416 phosphorylation. In stably-transfected human colon cancer cells, overexpression of FXR reduced EGFR, ERK, Src phosphorylation and cell proliferation, and in nude mice attenuated the growth of human colon cancer xenografts (64% reduction in tumor volume; 47% reduction in tumor weight; both P<0.01. Moreover, guggulsterone-induced EGFR and ERK phosphorylation and cell proliferation were abolished by inhibiting activation of Src, EGFR and MEK. Collectively these data support the novel conclusion that in human colon cancer cells Src-mediated cross-talk between FXR and EGFR modulates ERK phosphorylation, thereby regulating intestinal cell proliferation and tumorigenesis.

  13. Counting NMDA Receptors at the Cell Surface

    Czech Academy of Sciences Publication Activity Database

    Horák, Martin; Suh, Y. H.

    Totowa: Humana Press Inc., 2016, s. 31-44. (Neuromethods. 106). ISBN 978-1-4939-2811-8 R&D Projects: GA ČR(CZ) GA14-02219S Institutional support: RVO:67985823 Keywords : NMDA receptor * ionotropic glutamate receptor * mammalian cell lines * intracellular trafficking * quantitative assay * biotinylation assay * biochemistry Subject RIV: FH - Neurology

  14. Coexpression of Kit and the receptors for erythropoietin, interleukin 6 and GM-CSF on hemopoietic cells

    NARCIS (Netherlands)

    M.O. de Jong (Marg); Y. Westerman (Yvonne); G. Wagemaker (Gerard); A.W. Wognum (Albert)

    1997-01-01

    textabstractThe detection of functional growth factor (GF) receptors on subpopulations of hemopoietic cells may provide a further dissection of immature cell subsets. Since little information is available about coexpression of different GF receptors at the level of sing

  15. Interdependent epidermal growth factor receptor signalling and trafficking.

    Science.gov (United States)

    Jones, Sylwia; Rappoport, Joshua Z

    2014-06-01

    Epidermal growth factor (EGF) receptor (EGFR) signalling regulates diverse cellular functions, promoting cell proliferation, differentiation, migration, cell growth and survival. EGFR signalling is critical during embryogenesis, in particular in epithelial development, and disruption of the EGFR gene results in epithelial immaturity and perinatal death. EGFR signalling also functions during wound healing responses through accelerating wound re-epithelialisation, inducing cell migration, proliferation and angiogenesis. Upregulation of EGFR signalling is often observed in carcinomas and has been shown to promote uncontrolled cell proliferation and metastasis. Therefore aberrant EGFR signalling is a common target for anticancer therapies. Various reports indicate that EGFR signalling primarily occurs at the plasma membrane and EGFR degradation following endocytosis greatly attenuates signalling. Other studies argue that EGFR internalisation is essential for complete activation of downstream signalling cascades and that endosomes can serve as signalling platforms. The aim of this review is to discuss current understanding of intersection between EGFR signalling and trafficking. PMID:24681003

  16. Reassessing ecdysteroidogenic cells from the cell membrane receptors' perspective.

    Science.gov (United States)

    Alexandratos, Alexandros; Moulos, Panagiotis; Nellas, Ioannis; Mavridis, Konstantinos; Dedos, Skarlatos G

    2016-01-01

    Ecdysteroids secreted by the prothoracic gland (PG) cells of insects control the developmental timing of their immature life stages. These cells have been historically considered as carrying out a single function in insects, namely the biochemical conversion of cholesterol to ecdysteroids and their secretion. A growing body of evidence shows that PG cells receive multiple cues during insect development so we tested the hypothesis that they carry out more than just one function in insects. We characterised the molecular nature and developmental profiles of cell membrane receptors in PG cells of Bombyx mori during the final larval stage and determined what receptors decode nutritional, developmental and physiological signals. Through iterative approaches we identified a complex repertoire of cell membrane receptors that are expressed in intricate patterns and activate previously unidentified signal transduction cascades in PG cells. The expression patterns of some of these receptors explain precisely the mechanisms that are known to control ecdysteroidogenesis. However, the presence of receptors for the notch, hedgehog and wingless signalling pathways and the expression of innate immunity-related receptors such as phagocytosis receptors, receptors for microbial ligands and Toll-like receptors call for a re-evaluation of the role these cells play in insects. PMID:26847502

  17. Are different stoichiometries feasible for complexes between lymphotoxin-alpha and tumor necrosis factor receptor 1?

    OpenAIRE

    Mascarenhas Nahren; Kästner Johannes

    2012-01-01

    Abstract Background Tumor necrosis factors, TNF and lymphotoxin-α (LT), are cytokines that bind to two receptors, TNFR1 and TNFR2 (TNF-receptor 1 and 2) to trigger their signaling cascades. The exact mechanism of ligand-induced receptor activation is still unclear. It is generally assumed that three receptors bind to the homotrimeric ligand to trigger a signaling event. Recent evidence, though, has raised doubts if the ligand:receptor stoichiometry should indeed be 3:3 for ligand-induced cell...

  18. Ispaghula (Plantago ovata) seed husk polysaccharides promote proliferation of human epithelial cells (skin keratinocytes and fibroblasts) via enhanced growth factor receptors and energy production.

    Science.gov (United States)

    Deters, A M; Schröder, K R; Smiatek, T; Hensel, Andreas

    2005-01-01

    Endogenous carbohydrates, especially oligo- and polysaccharides, participate in the regulation of a broad range of biological activities, e. g., signal transduction, inflammation, fertilisation, cell-cell-adhesion and act as in vivo markers for the determination of cell types. In the present study, water-soluble (WS) and gel-forming polysaccharides (GF) of ispaghula seed husk (Plantago ovata Forsskal, Plantaginaceae) were characterised as neutral and acidic arabinoxylans and tested under in vitro conditions for regulating activities on cell physiology of human keratinocytes and human primary fibroblasts. Only water-soluble polysaccharides exhibited strong and significant effects on cell physiology of keratinocytes and fibroblasts. Proliferation of cells of the spontaneously immortalised keratinocyte cell line HaCaT was significantly up-regulated in a dose-independent manner. Analysis of activated signal pathways by RNA analysis proved an effect of the acidic arabinoxylan on the expression of keratinocyte growth factor (KGF) in HaCaT cells. Differentiation behaviour of normal human keratinocytes (NHK) determined by involucrin was slightly influenced, due to the enhanced cell proliferation, leading to a cell-cell-mediated indirect induction of early differentiation. WS did not influence late differentiation, as determined by keratin K1 and K10 titres. PMID:15678371

  19. Exploring the mechanism of non-small-cell lung cancer cell lines resistant to epidermal growth factor receptor tyrosine kinase inhibitor

    Directory of Open Access Journals (Sweden)

    Yongkang Yu

    2016-01-01

    Conclusions: The regulatory edges with remarkable changes between HCC827 and ER3, HCC827 and T15.2 included some transcription factors and genes. (e. g., STAT3 and SOX9. STAT3, SOX9, STAT5B, EGR1, and STAT6 might affect the resistance of NSCLC to erlotinib.

  20. Epidermal growth factor receptor in primary human lung cancer

    International Nuclear Information System (INIS)

    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 125I-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

  1. Inhibition of multiple vascular endothelial growth factor receptors (VEGFR) blocks lymph node metastases but inhibition of VEGFR-2 is sufficient to sensitize tumor cells to platinum-based chemotherapeutics.

    Science.gov (United States)

    Sini, Patrizia; Samarzija, Ivana; Baffert, Fabienne; Littlewood-Evans, Amanda; Schnell, Christian; Theuer, Andreas; Christian, Sven; Boos, Anja; Hess-Stumpp, Holger; Foekens, John A; Setyono-Han, Buddy; Wood, Jeanette; Hynes, Nancy E

    2008-03-01

    Vascular endothelial growth factor receptors (VEGFR) have important roles in cancer, affecting blood and lymphatic vessel functionality as well as tumor cells themselves. We compared the efficacy of a VEGFR tyrosine kinase inhibitor, PTK787/ZK222584 (PTK/ZK), which targets the three VEGFRs, with blocking antibodies directed against VEGFR-2 (DC101) or VEGF-A (Pab85618) in a metastatic melanoma model. Although all inhibitors exerted comparable effects on primary tumor growth, only PTK/ZK significantly reduced lymph node metastasis formation. A comparable decrease in lymphatic vessel density following blockade of VEGFR-2 (DC101) or the three VEGFRs (PTK/ZK) was observed in the metastases. However, the functionality of lymphatics surrounding the primary tumor was more significantly disrupted by PTK/ZK, indicating the importance of multiple VEGFRs in the metastatic process. The antimetastatic properties of PTK/ZK were confirmed in a breast carcinoma model. B16/BL6 tumor cells express VEGF ligands and their receptors. Blockade of a VEGFR-1 autocrine loop with PTK/ZK inhibited tumor cell migration. Furthermore, the tumor cells also showed enhanced sensitivity to platinum-based chemotherapy in combination with PTK/ZK, indicating that autocrine VEGFRs are promoting tumor cell migration and survival. In summary, our results suggest that, in addition to blocking angiogenesis, combined inhibition of the three VEGFRs may more efficiently target other aspects of tumor pathophysiology, including lymphatic vessel functionality, tumor cell dissemination, survival pathways, and response to chemotherapeutic compounds. PMID:18316624

  2. Thrombospondin-1 modulates vascular endothelial growth factor activity at the receptor level

    OpenAIRE

    Zhang, Xuefeng; Kazerounian, Shideh; Duquette, Mark; Perruzzi, Carole; Nagy, Janice A.; Dvorak, Harold F.; Parangi, Sareh; Lawler, Jack

    2009-01-01

    Vascular endothelial growth factor (VEGF) is a well-established stimulator of vascular permeability and angiogenesis, whereas thrombospondin-1 (TSP-1) is a potent angiogenic inhibitor. In this study, we have found that the TSP-1 receptors CD36 and β1 integrin associate with the VEGF receptor 2 (VEGFR2). The coclustering of receptors that regulate angiogenesis may provide the endothelial cell with a platform for integration of positive and negative signals in the plane of the membrane. Thus, t...

  3. Effects of alpha-calcitonin gene-related peptide on osteoprotegerin and receptor activator of nuclear factor-κB ligand expression in MG-63 osteoblast-like cells exposed to polyethylene particles

    Directory of Open Access Journals (Sweden)

    Kauther Max D

    2010-11-01

    Full Text Available Abstract Background Recent studies demonstrated an impact of the nervous system on particle-induced osteolysis, the major cause of aseptic loosening of joint replacements. Methods In this study of MG-63 osteoblast-like cells we analyzed the influence of ultra-high molecular weight polyethylene (UHMWPE particles and the neurotransmitter alpha-calcitonin gene-related peptide (CGRP on the osteoprotegerin/receptor activator of nuclear factor-κB ligand/receptor activator of nuclear factorκB (OPG/RANKL/RANK system. MG-63 cells were stimulated by different UHMWPE particle concentrations (1:100, 1:500 and different doses of alpha-CGRP (10-7 M, 10-9 M, 10-11 M. RANKL and OPG mRNA expression and protein levels were measured by RT-PCR and Western blot. Results Increasing particle concentrations caused an up-regulation of RANKL after 72 hours. Alpha-CGRP showed a dose-independent depressive effect on particle-induced expression of RANKL mRNA in both cell-particle ratios. RANKL gene transcripts were significantly (P -7 M lead to an up-regulation of OPG protein. Conclusion In conclusion, a possible osteoprotective influence of the neurotransmitter alpha-CGRP on particle stimulated osteoblast-like cells could be shown. Alpha-CGRP might be important for bone metabolism under conditions of particle-induced osteolysis.

  4. Development of a Quantitative PCR Assay for Detection of Human Insulin-Like Growth Factor Receptor and Insulin Receptor Isoforms.

    Science.gov (United States)

    Flannery, Clare A; Rowzee, Anne M; Choe, Gina H; Saleh, Farrah L; Radford, Caitlin C; Taylor, Hugh S; Wood, Teresa L

    2016-04-01

    The biological activity of insulin and the insulin-like growth factor (IGF) ligands, IGF-I and IGF-II, is based in part on the relative abundance and distribution of their target receptors: the insulin receptor (IR) splice variants A (IR-A) and B (IR-B) and IGF 1 receptor (IGF-1R). However, the relative quantity of all three receptors in human tissues has never been measured together on the same scale. Due to the high homology between insulin receptor (IR)-A and IR-B proteins and lack of antibodies that discern the two IR splice variants, their mRNA sequence is the most reliable means of distinguishing between the receptors. Hence, highly specific primers for IR-A, IR-B, and IGF-1R mRNA were designed to accurately detect all three receptors by quantitative RT-PCR and enable direct quantification of relative receptor expression levels. A standard concentration curve of cDNA from each receptor was performed. Assay specificity was tested using competition assays and postamplification analysis by gel electrophoresis and cloning. Forward and reverse primer concentrations were optimized to ensure equal efficiencies across primer pairs. This assay enables a specific molecular signature of IGF/insulin signaling receptors to be assayed in different tissues, cell types, or cancers. PMID:26862994

  5. Cell death sensitization of leukemia cells by opioid receptor activation

    Science.gov (United States)

    Friesen, Claudia; Roscher, Mareike; Hormann, Inis; Fichtner, Iduna; Alt, Andreas; Hilger, Ralf A.; Debatin, Klaus-Michael; Miltner, Erich

    2013-01-01

    Cyclic AMP (cAMP) regulates a number of cellular processes and modulates cell death induction. cAMP levels are altered upon stimulation of specific G-protein-coupled receptors inhibiting or activating adenylyl cyclases. Opioid receptor stimulation can activate inhibitory Gi-proteins which in turn block adenylyl cyclase activity reducing cAMP. Opioids such as D,L-methadone induce cell death in leukemia cells. However, the mechanism how opioids trigger apoptosis and activate caspases in leukemia cells is not understood. In this study, we demonstrate that downregulation of cAMP induced by opioid receptor activation using the opioid D,L-methadone kills and sensitizes leukemia cells for doxorubicin treatment. Enhancing cAMP levels by blocking opioid-receptor signaling strongly reduced D,L-methadone-induced apoptosis, caspase activation and doxorubicin-sensitivity. Induction of cell death in leukemia cells by activation of opioid receptors using the opioid D,L-methadone depends on critical levels of opioid receptor expression on the cell surface. Doxorubicin increased opioid receptor expression in leukemia cells. In addition, the opioid D,L-methadone increased doxorubicin uptake and decreased doxorubicin efflux in leukemia cells, suggesting that the opioid D,L-methadone as well as doxorubicin mutually increase their cytotoxic potential. Furthermore, we found that opioid receptor activation using D,L-methadone alone or in addition to doxorubicin inhibits tumor growth significantly in vivo. These results demonstrate that opioid receptor activation via triggering the downregulation of cAMP induces apoptosis, activates caspases and sensitizes leukemia cells for doxorubicin treatment. Hence, opioid receptor activation seems to be a promising strategy to improve anticancer therapies. PMID:23633472

  6. HBpF-proBDNF: A New Tool for the Analysis of Pro-Brain Derived Neurotrophic Factor Receptor Signaling and Cell Biology.

    Science.gov (United States)

    Gaub, Perrine; de Léon, Andrès; Gibon, Julien; Soubannier, Vincent; Dorval, Geneviève; Séguéla, Philippe; Barker, Philip A

    2016-01-01

    Neurotrophins activate intracellular signaling pathways necessary for neuronal survival, growth and apoptosis. The most abundant neurotrophin in the adult brain, brain-derived neurotrophic factor (BDNF), is first synthesized as a proBDNF precursor and recent studies have demonstrated that proBDNF can be secreted and that it functions as a ligand for a receptor complex containing p75NTR and sortilin. Activation of proBDNF receptors mediates growth cone collapse, reduces synaptic activity, and facilitates developmental apoptosis of motoneurons but the precise signaling cascades have been difficult to discern. To address this, we have engineered, expressed and purified HBpF-proBDNF, an expression construct containing a 6X-HIS tag, a biotin acceptor peptide (BAP) sequence, a PreScission™ Protease cleavage site and a FLAG-tag attached to the N-terminal part of murine proBDNF. Intact HBpF-proBDNF has activities indistinguishable from its wild-type counterpart and can be used to purify proBDNF signaling complexes or to monitor proBDNF endocytosis and retrograde transport. HBpF-proBDNF will be useful for characterizing proBDNF signaling complexes and for deciphering the role of proBDNF in neuronal development, synapse function and neurodegenerative disease. PMID:26950209

  7. Tyrosine kinase JAK1 is associated with the granulocyte-colony-stimulating factor receptor and both become tyrosine-phosphorylated after receptor activation.

    OpenAIRE

    Nicholson, S. E.; Oates, A. C.; Harpur, A G; Ziemiecki, A; Wilks, A F; Layton, J E

    1994-01-01

    Granulocyte-colony-stimulating factor (G-CSF) stimulates the proliferation and differentiation of cells of the neutrophil lineage by interaction with a specific receptor. Early signal transduction events following G-CSF receptor activation were studied. We detected tyrosine phosphorylation of both the G-CSF receptor and the protein tyrosine kinase JAK1 following G-CSF binding to the human G-CSF receptor. In vitro, the kinase activity of JAK1 was increased by G-CSF stimulation. Coimmunoprecipi...

  8. Interactions of the ubiquitous octamer-binding transcription factor-1 with both the signal transducer and activator of transcription 5 and the glucocorticoid receptor mediate prolactin and glucocorticoid-induced β-casein gene expression in mammary epithelial cells.

    Science.gov (United States)

    Qian, Xi; Zhao, Feng-Qi

    2013-03-01

    Regulation of milk protein gene expression by lactogenic hormones (prolactin and glucocorticoids) provides an attractive model for studying the mechanisms by which protein and steroid hormones synergistically regulate gene expression. β-Casein is one of the major milk proteins and its expression in mammary epithelial cells is stimulated by lactogenic hormones. The signal transducer and activator of transcription 5 and glucocorticoid receptor are essential downstream mediators of prolactin and glucocorticoid signaling, respectively. Previous studies have shown that mutating the octamer-binding site of the β-casein gene proximal promoter dramatically reduces the hormonal induction of the promoter activity. However, little is known about the underlying molecular mechanisms. In this report, we show that lactogenic hormones rapidly induce the binding of octamer-binding transcription factor-1 to the β-casein promoter and this induction is not mediated by either increasing the expression of octamer-binding transcription factor-1 or inducing its translocation to the nucleus. Rather, lactogenic hormones induce physical interactions between the octamer-binding transcription factor-1, signal transducer and activator of transcription 5, and glucocorticoid receptor to form a ternary complex, and these interactions enhance or stabilize the binding of these transcription factors to the promoter. Abolishing these interactions significantly reduces the hormonal induction of β-casein gene transcription. Thus, our study indicates that octamer-binding transcription factor-1 may serve as a master regulator that facilitates the DNA binding of both signal transducer and activator of transcription 5 and glucocorticoid receptor in hormone-induced β-casein expression, and defines a novel mechanism of regulation of tissue-specific gene expression by the ubiquitous octamer-binding transcription factor-1. PMID:23313770

  9. Epidermal Growth Factor Receptor Regulates Aberrant Expression of Insulin-Like Growth Factor-Binding Protein 3

    OpenAIRE

    TAKAOKA, MUNENORI; Harada, Hideki; Andl, Claudia D; Oyama, Kenji; Naomoto, Yoshio; Dempsey, Kelly L.; Klein-Szanto, Andres J.; El-Deiry, Wafik S; GRIMBERG, ADDA; Nakagawa, Hiroshi

    2004-01-01

    Epidermal growth factor receptor (EGFR) is frequently overexpressed in esophageal carcinoma and its precursor lesions. To gain insights into how EGFR overexpression affects cellular functions in primary human esophageal cells, we performed gene expression profiling and identified insulin-like growth factor-binding protein (IGFBP)-3 as the most up-regulated gene. IGFBP-3 regulates cell proliferation through both insulin-like growth factor-dependent and independent mechanisms. We found that IGF...

  10. Angiotensin II-Induced Migration of Vascular Smooth Muscle Cells Is Mediated by p38 Mitogen-Activated Protein Kinase-Activated c-Src Through Spleen Tyrosine Kinase and Epidermal Growth Factor Receptor Transactivation

    OpenAIRE

    Mugabe, Benon E.; Yaghini, Fariborz A.; Song, Chi Young; Buharalioglu, Cuneyt K.; Waters, Christopher M.; Malik, Kafait U.

    2010-01-01

    Angiotensin II (Ang II) stimulates protein synthesis by activating spleen tyrosine kinase (Syk) and DNA synthesis through epidermal growth factor receptor (EGFR) transactivation in vascular smooth muscle cells (VSMCs). This study was conducted to determine whether Syk mediates Ang II-induced migration of aortic VSMCs using a scratch wound approach. Treatment with Ang II (200 nM) for 24 h increased VSMC migration by 1.56 ± 0.14-fold. Ang II-induced VSMC migration and Syk phosphorylation as det...

  11. Isolation of an additional member of the fibroblast growth factor receptor family, FGFR-3

    International Nuclear Information System (INIS)

    The fibroblast growth factors are a family of polypeptide growth factors involved in a variety of activities including mitogenesis, angiogenesis, and wound healing. Fibroblast growth factor receptors (FGFRs) have previously been identified in chicken, mouse, and human and have been shown to contain an extracellular domain with either two or three immunoglobulin-like domains, a transmembrane domain, and a cytoplasmic tyrosine kinase domain. The authors have isolated a human cDNA for another tyrosine kinase receptor that is highly homologous to the previously described FGFR. Expression of this receptor cDNA in COS cells directs the expression of a 125-kDa glycoprotein. They demonstrate that this cDNA encodes a biologically active receptor by showing that human acidic and basic fibroblast growth factors activate this receptor as measured by 45Ca2+ efflux assays. These data establish the existence of an additional member of the FGFR family that they have named FGFR-3

  12. Impact of adjuvant inhibition of vascular endothelial growth factor receptor tyrosine kinases on tumor growth delay and local tumor control after fractionated irradiation in human squamous cell carcinomas in nude mice

    International Nuclear Information System (INIS)

    Purpose: Previous experiments have shown that adjuvant inhibition of the vascular endothelial growth factor receptor after fractionated irradiation prolonged tumor growth delay and may also improve local tumor control. To test the latter hypothesis, local tumor control experiments were performed. Methods and materials: Human FaDu and UT-SCC-14 squamous cell carcinomas were studied in nude mice. The vascular endothelial growth factor receptor tyrosine kinase inhibitor PTK787/ZK222584 (50 mg/kg body weight b.i.d.) was administered for 75 days after irradiation with 30 fractions within 6 weeks. Tumor growth time and tumor control dose 50% (TCD50) were determined and compared to controls (carrier without PTK787/ZK222584). Results: Adjuvant administration of PTK787/ZK222584 significantly prolonged tumor growth time to reach 5 times the volume at start of drug treatment by an average of 11 days (95% confidence interval 0.06;22) in FaDu tumors and 29 days (0.6;58) in UT-SCC-14 tumors. In both tumor models, TCD50 values were not statistically significantly different between the groups treated with PTK787/ZK222584 compared to controls. Conclusions: Long-term inhibition of angiogenesis after radiotherapy significantly reduced the growth rate of local recurrences but did not improve local tumor control. This indicates that recurrences after irradiation depend on vascular endothelial growth factor-driven angiogenesis, but surviving tumor cells retain their clonogenic potential during adjuvant antiangiogenic treatment with PTK787/ZK222584

  13. Expression of Transcription Factors and Nuclear Receptors in Mixed Germ Cell-Sex Cord Stromal Tumor and Related Tumors of the Gonads.

    Science.gov (United States)

    Roth, Lawrence M; Cheng, Liang

    2015-11-01

    In this study, we compare the expression of OCT4, SALL4, and TSPYL1 in mixed germ cell-sex cord stromal tumor (MGC-SCST) of either gonad to that of normal adult testis, classic and spermatocytic seminoma, intratubular germ cell neoplasia, unclassified, gonadoblastoma, and dysgerminoma to determine the entity or entities that most closely resemble MGC-SCST by immunohistochemistry of germ cells. The most useful transcription factor was OCT4. In addition, to its already described value in distinguishing germinoma and embryonal carcinoma from yolk sac tumor and in differentiating classic from spermatocytic seminoma, we found that OCT4 is useful in confirming or ruling out potential malignancy in MGC-SCST of either gonad. Expression of OCT4 in most ovarian MGC-SCSTs resembles that of dysgerminoma, whereas most testicular examples resemble that of spermatocytic seminoma and normal adult testis. Thus, most MGC-SCSTs of the ovary are potentially malignant, and corresponding tumors of the testis are mostly benign; however, exceptions likely can be detected by the use of OCT4, potentially leading to more appropriate clinical management in some cases. SALL4 is an underutilized transcription factor that is useful in distinguishing testicular MGC-SCST from sex cord stromal tumor, unclassified in those neoplasms where the germ cells are sparse or unevenly distributed. Compared with other transcription factors studied, TSPY and its congener TSPYL1 have little value in the assessment of germ cell tumors because of their relatively wide range of expression in normal adult testis and in germ cell tumors. PMID:26107563

  14. Krüppel-like factor 9 regulates cell proliferation and compartmental expression of estrogen and progesterone receptors in the mouse uterine endometrium

    Science.gov (United States)

    The uterine endometrium undergoes dynamic changes in proliferation and differentiation in response to estrogen (E) and progesterone (P) during the estrous cycle and pregnancy. E and P exert their functions through their respective nuclear receptors, estrogen receptor (ESR) and progesterone receptor ...

  15. The effect of Chinese herbal medicine"heche assisted pregnancy recipe"on endometrial estrogen and progesterone receptor, proliferating cell nuclear antigen and vascular endothelial growth factor in the patients with infertility

    Institute of Scientific and Technical Information of China (English)

    刘效群; 阚国英; 彭玉梅; 樊瑞琴; 齐惠敏; 焦妹芬; 李忠; 石彬; 尹桂然; 董锡月

    2003-01-01

    Objectives:To investigate the effect of Chinese herbal medicine"heche assisted preg-nancy recipe (HCAPR)" on estrogen receptor(ER), progesterone receptor (PR), pro-lifierating cell nuclear antigen(PCNA) and vascular endothelial growth factor (VEGF)in endometrium of infertile women.Methods: The S-P immunohistochemical assay was used to observe expression ofER, PR , PCNA and VEGF in late proliferative phase before and after the HCAPR treat-ment.Results: After the treatment, the expression of ER,PR,PCNA and VEGF in nucleiof glandular epithelium and stromal cells was significantly stronger (all P<0. 001) re-spectively than that before treatment , especially the expression of PCNA and VEGF.Conclusions: These results suggest that traditional Chinese medicine HCAPR oftonifying kidney and regulating menstruation increased the synthesis of ER,PR, PCNAand VEGF, which may promote normal growth and development of the endometrium ,improve the micro-environment of the endometrium, and enhance uterine receptivity.The evidence may provide theoretical basis for therapy infertility with Chinese herbalmedicine.

  16. Transitional cell carcinoma express vitamin D receptors

    DEFF Research Database (Denmark)

    Hermann, G G; Andersen, C B

    1997-01-01

    Recently, vitamin D analogues have shown antineoplastic effect in several diseases. Vitamin D analogues exert its effect by interacting with the vitamin D receptor (VDR). Studies of VDR in transitional cell carcinoma (TCC) have not been reported. The purpose of the present study was therefore.......05). Similarly, also tumor grade appeared to be related to the number of cells expressing the receptor. Normal urothlium also expressed VDR but only with low intensity. Our study shows that TCC cells possess the VDR receptor which may make them capable to respond to stimulation with vitamin D, but functional...... studies of vitamin D's effect on TCC cells in vitro are necessary before the efficacy of treatment with vitamin D analogues in TCC can be evaluated in patients....

  17. Involvement of Toll-like receptor 2 and epidermal growth factor receptor signaling in epithelial expression of airway remodeling factors.

    Science.gov (United States)

    Homma, Tetsuya; Kato, Atsushi; Sakashita, Masafumi; Norton, James E; Suh, Lydia A; Carter, Roderick G; Schleimer, Robert P

    2015-04-01

    Staphylococcus aureus (SA) colonization and infection is common, and may promote allergic or inflammatory airway diseases, such as asthma, cystic fibrosis, and chronic rhinosinusitis by interacting with airway epithelial cells. Airway epithelial cells not only comprise a physical barrier, but also play key roles in immune, inflammatory, repair, and remodeling responses upon encounters with pathogens. To elucidate the impact of SA on epithelial-mediated remodeling of allergic airways, we tested the hypothesis that SA can enhance the remodeling process. Normal human bronchial epithelial (NHBE) cells were stimulated with heat-killed SA (HKSA) or transforming growth factor (TGF) α. Cell extracts were collected to measure mRNA (real-time RT-PCR) and signaling molecules (Western blot); supernatants were collected to measure protein (ELISA) after 24 hours of stimulation. Epidermal growth factor receptor (EGFR) signaling inhibition experiments were performed using a specific EGFR kinase inhibitor (AG1478) and TGF-α was blocked with an anti-TGF-α antibody. HKSA induced both mRNA and protein for TGF-α and matrix metalloproteinase (MMP) 1 from NHBE cells by a Toll-like receptor 2-dependent mechanism. Recombinant human TGF-α also induced mRNA and protein for MMP-1 from NHBE cells; anti-TGF-α antibody inhibited HKSA-induced MMP-1, suggesting that endogenous TGF-α mediates the MMP-1 induction by HKSA. HKSA-induced MMP-1 expression was suppressed when a specific EGFR kinase inhibitor was added, suggesting that EGFR signaling was mediating the HKSA-induced MMP-1 release. Exposure or colonization by SA in the airway may enhance the remodeling of tissue through a TGF-α-dependent induction of MMP-1 expression, and may thereby promote remodeling in airway diseases in which SA is implicated, such as asthma and chronic rhinosinusitis. PMID:25180535

  18. Effects of Ginsenoside Rg1 on the Expression of Toll-Like Receptor 3, 4 and Their Signalling Transduction Factors in the NG108-15 Murine Neuroglial Cell Line

    Directory of Open Access Journals (Sweden)

    Bao-Sheng Zhao

    2014-10-01

    Full Text Available As one of the most important components of Panax ginseng, ginsenoside Rg1 has certain anti-aging effects, improving the activity of learning and memory. Studies have showed that ginsenoside Rg1 improves the memory impairment associated with Alzheimer’s disease (AD. In this study, the effects of ginsenoside Rg1 were investigated through the activity of toll-like receptor (TLR 3, TLR4 and their signaling transduction pathways in amyloid β peptide 25–35 (Aβ25–35 induced AD cell model. Thus we investigated several critical components of the TLR pathway. The neuroglial cell line NG108-15 was stimulated with or without Aβ25–35, while different concentrations of ginsenoside Rg1 were administered. After 24 h, tumor necrosis factor-α (TNF-α, interferon-β (IFN-β in cell supernatant and inducible nitric oxide synthase (iNOS in cell lysate supernatant were measured with enzyme-linked immunosorbent assays (ELISAs. The mRNA and protein expression of TLR3, TLR4, nuclear factor kappa B (NF-κB and tumor necrosis factor receptor-associated factor-6 (TRAF-6 were detected by real-time PCR and western blot methods, respectively. The experimental results showed that Aβ25–35 could markedly raise the level of TNF-α, IFN-β and iNOS, and increase the expressions of mRNA and TLR3, TLR4, NF-κB and TRAF-6 protein in the NG108-15 cells. At the same time, the ginsenoside Rg1 significantly reduced the expressions of proteins and mRNA of TLR3, TLR4, NF-κB and TRAF-6, and down-regulated the levels of TNF-α, IFN-β of cell supernatant and iNOS of cell lysate supernatant in a concentration-dependent manner. In conclusion, ginsenoside Rg1 has good activity for suppressing the signaling transduction pathway of TLR3 and TLR4, and decreasing the inflammation factors induced by Aβ25–35 in NG108-15 cells, and this may be the mechanism of ginsenoside Rg1 action in AD treatment, but more studies are needed to identify its specificity.

  19. Exogenous Restoration of TUSC2 Expression Induces Responsiveness to Erlotinib in Wildtype Epidermal Growth Factor Receptor (EGFR Lung Cancer Cells through Context Specific Pathways Resulting in Enhanced Therapeutic Efficacy.

    Directory of Open Access Journals (Sweden)

    Bingbing Dai

    Full Text Available Expression of the tumor suppressor gene TUSC2 is reduced or absent in most lung cancers and is associated with worse overall survival. In this study, we restored TUSC2 gene expression in several wild type EGFR non-small cell lung cancer (NSCLC cell lines resistant to the epidermal growth factor receptor (EGFR tyrosine kinase inhibitor erlotinib and analyzed their sensitivity to erlotinib in vitro and in vivo. A significant inhibition of cell growth and colony formation was observed with TUSC2 transient and stable expression. TUSC2-erlotinib cooperativity in vitro could be reproduced in vivo in subcutaneous tumor growth and lung metastasis formation lung cancer xenograft mouse models. Combination treatment with intravenous TUSC2 nanovesicles and erlotinib synergistically inhibited tumor growth and metastasis, and increased apoptotic activity. High-throughput qRT-PCR array analysis enabling multi-parallel expression profile analysis of eighty six receptor and non-receptor tyrosine kinase genes revealed a significant decrease of FGFR2 expression level, suggesting a potential role of FGFR2 in TUSC2-enhanced sensitivity to erlotinib. Western blots showed inhibition of FGFR2 by TUSC2 transient transfection, and marked increase of PARP, an apoptotic marker, cleavage level after TUSC2-erlotinb combined treatment. Suppression of FGFR2 by AZD4547 or gene knockdown enhanced sensitivity to erlotinib in some but not all tested cell lines. TUSC2 inhibits mTOR activation and the latter cell lines were responsive to the mTOR inhibitor rapamycin combined with erlotinib. These results suggest that TUSC2 restoration in wild type EGFR NSCLC may overcome erlotinib resistance, and identify FGFR2 and mTOR as critical regulators of this activity in varying cellular contexts. The therapeutic activity of TUSC2 could extend the use of erlotinib to lung cancer patients with wildtype EGFR.

  20. Increased expression of fibroblast growth factor receptor 3 in CD34+ BCR-ABL+ cells from patients with chronic myeloid leukemia

    Czech Academy of Sciences Publication Activity Database

    Dvořák, Petr; Dvořáková, D.; Doubek, M.; Faitová, Jitka; Pacholíková, J.; Hampl, Aleš; Mayer, J.

    2003-01-01

    Roč. 17, - (2003), s. 1-8. ISSN 0887-6924 R&D Projects: GA ČR GA301/03/1122; GA MŠk LN00A065 Institutional research plan: CEZ:AV0Z5039906; CEZ:MSM 00065269705; CEZ:VZ432100001 Keywords : CD34+cells, imatinib Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 5.116, year: 2003

  1. Cycloart-24-ene-26-ol-3-one, a New Cycloartane Isolated from Leaves of Aglaia exima Triggers Tumour Necrosis Factor-Receptor 1-Mediated Caspase-Dependent Apoptosis in Colon Cancer Cell Line

    Science.gov (United States)

    Loong, Xe-Min; Cheah, Foo Kit; Supratman, Unang; Litaudon, Marc; Mustafa, Mohd Rais; Awang, Khalijah

    2016-01-01

    Plants in the Meliaceae family are known to possess interesting biological activities, such as antimalaral, antihypertensive and antitumour activities. Previously, our group reported the plant-derived compound cycloart-24-ene-26-ol-3-one isolated from the hexane extracts of Aglaia exima leaves, which shows cytotoxicity towards various cancer cell lines, in particular, colon cancer cell lines. In this report, we further demonstrate that cycloart-24-ene-26-ol-3-one, from here forth known as cycloartane, reduces the viability of the colon cancer cell lines HT-29 and CaCO-2 in a dose- and time-dependent manner. Further elucidation of the compound’s mechanism showed that it binds to tumour necrosis factor-receptor 1 (TNF-R1) leading to the initiation of caspase-8 and, through the activation of Bid, in the activation of caspase-9. This activity causes a reduction in mitochondrial membrane potential (MMP) and the release of cytochrome-C. The activation of caspase-8 and -9 both act to commit the cancer cells to apoptosis through downstream caspase-3/7 activation, PARP cleavage and the lack of NFkB translocation into the nucleus. A molecular docking study showed that the cycloartane binds to the receptor through a hydrophobic interaction with cysteine-96 and hydrogen bonds with lysine-75 and -132. The results show that further development of the cycloartane as an anti-cancer drug is worthwhile. PMID:27070314

  2. High value of the radiobiological parameter Dq correlates to expression of the transforming growth factor beta type II receptor in a panel of small cell lung cancer cell lines

    DEFF Research Database (Denmark)

    Hougaard, S; Krarup, M; Nørgaard, P; Damstrup, L; Spang-Thomsen, M; Poulsen, H S

    1998-01-01

    Our panel of SCLC cell lines have previously been examined for their radiobiological characteristics and sensitivity to treatment with TGF beta 1. In this study we examined the possible correlations between radiobiological parameters and the expression of the TGF beta type II receptor (TGF beta...... role for the repair of radiation induced DNA damage in SCLC....

  3. Epidermal growth factor receptor cooperates with Src family kinases in acquired resistance to cetuximab

    OpenAIRE

    Wheeler, Deric L; Iida, Mari; Kruser, Tim J.; Nechrebecki, Meghan M.; Dunn, Emily F.; Armstrong, Eric A.; Huang, Shyhmin; Harari, Paul M.

    2009-01-01

    The epidermal growth factor receptor (EGFR) is a receptor tyrosine kinase that plays a major role in oncogenesis. Cetuximab is an EGFR-blocking antibody that is FDA approved for use in patients with metastatic colorectal cancer (mCRC) and head and neck squamous cell carcinoma (HNSCC). Although cetuximab has shown strong clinical benefit for a subset of cancer patients, most become refractory to cetuximab therapy. We reported that cetuximab-resistant NSCLC line NCI-H226 cells have increased st...

  4. Expression of basic fibroblast growth factor and its receptor in human pancreatic carcinomas.

    OpenAIRE

    Ohta, T.(Research Center for Nuclear Physics, Osaka University, Ibaraki, Osaka 567-0047, Japan); Yamamoto, M.; Numata, M; Iseki, S.; Tsukioka, Y.; Miyashita, T; Kayahara, M.; Nagakawa, T.; Miyazaki, I.; Nishikawa, K.; Yoshitake, Y

    1995-01-01

    We examined the expression of basic fibroblast growth factor (FGF) and FGF receptor by immunohistochemistry in 32 human pancreatic ductal adenocarcinomas. Mild to marked basic FGF immunoreactivity was noted in 19 (59.4%) of the 32 tumours examined, and 30 (93.3%) of the tumours exhibited a cytoplasmic staining pattern against FGF receptor. The tumours were divided into two groups according to the proportion of positively stained tumour cells: a low expression group (positive cells < 25%) and ...

  5. Regulation of human cardiac KCNQ1/KCNE1 channel by epidermal growth factor receptor kinase

    OpenAIRE

    Dong, MQ; Sun, HY; Tang, Q.; Tse, HF; Lau, CP; Li, GR

    2010-01-01

    The aim of the present study was to investigate whether/how the recombinant human cardiac I Ks could be regulated by epidermal growth factor receptor kinase in HEK 293 cells stably expressing hKCNQ1/hKCNE1 genes using the approaches of perforated patch clamp technique, immunoprecipitation and Western blot analysis. It was found that the broad spectrum isoflavone tyrosine kinase inhibitor genistein and the selective epidermal growth factor receptor kinase inhibitor tyrphostin AG556 suppressed ...

  6. Identification of ciliary neurotrophic factor (CNTF) residues essential for leukemia inhibitory factor receptor binding and generation of CNTF receptor antagonists.

    OpenAIRE

    Di Marco, A; Gloaguen, I; Graziani, R; Paonessa, G; Saggio, I; Hudson, K R; Laufer, R

    1996-01-01

    Ciliary neurotrophic factor (CNTF) drives the sequential assembly of a receptor complex containing the ligand-specific alpha-receptor subunit (CNTFR alpha) and the signal transducers gp130 and leukemia inhibitory factor receptor-beta (LIFR). The D1 structural motif, located at the beginning of the D-helix of human CNTF, contains two amino acid residues, F152 and K155, which are conserved among all cytokines that signal through LIFR. The functional importance of these residues was assessed by ...

  7. Combinatorial-Designed Epidermal Growth Factor Receptor-Targeted Chitosan Nanoparticles for Encapsulation and Delivery of Lipid-Modified Platinum Derivatives in Wild-Type and Resistant Non-Small-Cell Lung Cancer Cells.

    Science.gov (United States)

    Nascimento, Ana Vanessa; Singh, Amit; Bousbaa, Hassan; Ferreira, Domingos; Sarmento, Bruno; Amiji, Mansoor M

    2015-12-01

    Development of efficient and versatile drug delivery platforms to overcome the physical and biological challenges in cancer therapeutics is an area of great interest, and novel materials are actively sought for such applications. Recent strides in polymer science have led to a combinatorial approach for generating a library of materials with different functional identities that can be "mixed and matched" to attain desired characteristics of a delivery vector. We have applied the combinatorial design to chitosan (CS), where the polymer backbone has been modified with polyethylene glycol, epidermal growth factor receptor-binding peptide, and lipid derivatives of varying chain length to encapsulate hydrophobic drugs. Cisplatin, cis-([PtCl2(NH3)2]), is one of the most potent chemotherapy drugs broadly administered for cancer treatment. Cisplatin is a hydrophilic drug, and in order for it to be encapsulated in the developed nanosystems, it was modified with lipids of varying chain length. The library of four CS derivatives and six platinum derivatives was self-assembled in aqueous medium and evaluated for physicochemical characteristics and cytotoxic effects in platinum-sensitive and -resistant lung cancer cells. The results show that the lipid-modified platinate encapsulation into CS nanoparticles significantly improved cellular cytotoxicity of the drug. In this work, we have also reinforced the idea that CS is a multifaceted system that can be as successful in delivering small molecules as it has been as a nucleic acids carrier. PMID:26523837

  8. Epidermal growth factor receptor inhibition in lung cancer: status 2012.

    Science.gov (United States)

    Hirsch, Fred R; Jänne, Pasi A; Eberhardt, Wilfried E; Cappuzzo, Federico; Thatcher, Nick; Pirker, Robert; Choy, Hak; Kim, Edward S; Paz-Ares, Luis; Gandara, David R; Wu, Yi-Long; Ahn, Myung-Ju; Mitsudomi, Tetsuya; Shepherd, Frances A; Mok, Tony S

    2013-03-01

    Lung cancer is the most common cause of cancer deaths. Most patients present with advanced-stage disease, and the prognosis is generally poor. However, with the understanding of lung cancer biology, and development of molecular targeted agents, there have been improvements in treatment outcomes for selected subsets of patients with non-small-cell lung cancer (NSCLC). Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) have demonstrated significantly improved tumor responses and progression-free survival in subsets of patients with advanced NSCLC, particularly those with tumors harboring activating EGFR mutations. Testing for EGFR mutations is a standard procedure for identification of patients who will benefit from first-line EGFR TKIs. For patients with advanced NSCLC and no activating EGFR mutations (EGFR wild-type) or no other driving oncogenes such as ALK-gene rearrangement, chemotherapy is still the standard of care. A new generation of EGFR TKIs, targeting multiple receptors and with irreversible bindings to the receptors, are in clinical trials and have shown encouraging effects. Research on primary and acquired resistant mechanisms to EGFR TKIs are ongoing. Monoclonal antibodies (e.g. cetuximab), in combination with chemotherapy, have demonstrated improved outcomes, particularly for subsets of NSCLC patients, but further validations are needed. Novel monoclonal antibodies are combined with chemotherapy, and randomized comparative studies are ongoing. This review summarizes the current status of EGFR inhibitors in NSCLC in 2012 and some of the major challenges we are facing. PMID:23370315

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

    International Nuclear Information System (INIS)

    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, 125I-epidermal growth factor specific binding, epidermal growth factor receptor protein expression, and 3H-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, 125I-epidermal growth factor specific binding to hepatocytes decreased time-dependently (to 54.1% of normoxia) and was restored to control levels by reoxygenation, although 125I-insulin specific binding was not affected. The decrease in 125I-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/105 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 125I-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 125I-epidermal growth factor binding. (au)

  10. Selenoprotein W controls epidermal growth factor receptor surface expression, activation and degradation via receptor ubiquitination

    Science.gov (United States)

    Epidermal growth factor (EGF) receptor (EGFR) is the founding member of the ErbB family of growth factor receptors that modulate a complex network of intracellular signaling pathways controlling growth, proliferation and differentiation. Selenoprotein W (SEPW1) is a diet-regulated, highly conserved...

  11. Peroxisome Proliferator-Activated Receptor and Vitamin D Receptor Signaling Pathways in Cancer Cells

    International Nuclear Information System (INIS)

    Peroxisome proliferator-activated receptors (PPARs) are members of the superfamily of nuclear hormone receptors, which respond to specific ligands such as polyunsaturated fatty acids by altering gene expression. Three subtypes of this receptor have been discovered, each evolving to achieve different biological functions. Like other nuclear receptors, the transcriptional activity of PPARs is affected not only by ligand-stimulation, but also by cross-talk with other molecules. For example, both PPARs and the RXRs are ligand-activated transcription factors that coordinately regulate gene expression. In addition, PPARs and vitamin D receptor (VDR) signaling pathways regulate a multitude of genes that are of importance for cellular functions including cell proliferation and cell differentiation. Interaction of the PPARs and VDR signaling pathways has been shown at the level of molecular cross-regulation of their transcription factor. A variety of ligands influencing the PPARs and VDR signaling pathways have been shown to reveal chemopreventive potential by mediating tumor suppressive activities in human cancers. Use of these compounds may represent a potential novel strategy to prevent cancers. This review summarizes the roles of the PPARs and the VDR in pathogenesis and progression of cancer

  12. Peroxisome Proliferator-Activated Receptor and Vitamin D Receptor Signaling Pathways in Cancer Cells

    Directory of Open Access Journals (Sweden)

    Yasuko Kitagishi

    2013-10-01

    Full Text Available Peroxisome proliferator-activated receptors (PPARs are members of the superfamily of nuclear hormone receptors, which respond to specific ligands such as polyunsaturated fatty acids by altering gene expression. Three subtypes of this receptor have been discovered, each evolving to achieve different biological functions. Like other nuclear receptors, the transcriptional activity of PPARs is affected not only by ligand-stimulation, but also by cross-talk with other molecules. For example, both PPARs and the RXRs are ligand-activated transcription factors that coordinately regulate gene expression. In addition, PPARs and vitamin D receptor (VDR signaling pathways regulate a multitude of genes that are of importance for cellular functions including cell proliferation and cell differentiation. Interaction of the PPARs and VDR signaling pathways has been shown at the level of molecular cross-regulation of their transcription factor. A variety of ligands influencing the PPARs and VDR signaling pathways have been shown to reveal chemopreventive potential by mediating tumor suppressive activities in human cancers. Use of these compounds may represent a potential novel strategy to prevent cancers. This review summarizes the roles of the PPARs and the VDR in pathogenesis and progression of cancer.

  13. Peroxisome Proliferator-Activated Receptor and Vitamin D Receptor Signaling Pathways in Cancer Cells

    Energy Technology Data Exchange (ETDEWEB)

    Matsuda, Satoru, E-mail: smatsuda@cc.nara-wu.ac.jp; Kitagishi, Yasuko [Department of Food Science and Nutrition, Nara Women’s University, Kita-Uoya Nishimachi, Nara 630-8506 (Japan)

    2013-10-21

    Peroxisome proliferator-activated receptors (PPARs) are members of the superfamily of nuclear hormone receptors, which respond to specific ligands such as polyunsaturated fatty acids by altering gene expression. Three subtypes of this receptor have been discovered, each evolving to achieve different biological functions. Like other nuclear receptors, the transcriptional activity of PPARs is affected not only by ligand-stimulation, but also by cross-talk with other molecules. For example, both PPARs and the RXRs are ligand-activated transcription factors that coordinately regulate gene expression. In addition, PPARs and vitamin D receptor (VDR) signaling pathways regulate a multitude of genes that are of importance for cellular functions including cell proliferation and cell differentiation. Interaction of the PPARs and VDR signaling pathways has been shown at the level of molecular cross-regulation of their transcription factor. A variety of ligands influencing the PPARs and VDR signaling pathways have been shown to reveal chemopreventive potential by mediating tumor suppressive activities in human cancers. Use of these compounds may represent a potential novel strategy to prevent cancers. This review summarizes the roles of the PPARs and the VDR in pathogenesis and progression of cancer.

  14. RNA Interference of Interferon Regulatory Factor-1 Gene Expression in THP-1 Cell Line Leads to Toll-Like Receptor-4 Overexpression/Activation As Well As Up-modulation of Annexin-II

    Directory of Open Access Journals (Sweden)

    Christos I. Maratheftis

    2007-12-01

    Full Text Available Interferon regulatory factor-1 (IRF-1 is a candidate transcription factor for the regulation of the Toll-like receptor-4 (TLR-4 gene. Using a small interfering RNAbased (siRNA process to silence IRF-1 gene expression in the leukemic monocytic cell line THP-1, we investigated whether such a modulation would alter TLR-4 expression and activation status in these cells. The siIRF-1 cells expressed elevated levels of TLR-4 mRNA and protein compared to controls by 90% and 77%, respectively. ICAM.1 protein expression and apoptosis levels were increased by 8.35- and 4.25-fold, respectively. The siIRF-1 cells overexpressed Bax mRNA compared to controls. Proteomic analysis revealed upmodulation of the Annexin-II protein in siIRF-1 THP-1 cells. Myelodysplastic syndrome (MDS patients with an absence of full-length IRF-1 mRNA also overexpressed Annexin-II. It is plausible that this overexpression may lead to the activation of TLR-4 contributing to the increased apoptosis characterizing MDS.

  15. Unimpaired Autoreactive T-Cell Traffic Within the Central Nervous System During Tumor Necrosis Factor Receptor-Mediated inhibition of Experimental Autoimmune Encephalomyelitis

    Science.gov (United States)

    Korner, Heinrich; Goodsall, Anna L.; Lemckert, Frances A.; Scallon, Bernard J.; Ghrayeb, John; Ford, Andrew L.; Sedgwick, Jonathon D.

    1995-11-01

    The critical role of tumor necrosis factor (TNF) as a mediator in autoimmune inflammatory processes is evident from in vivo studies with TNF-blocking agents. However, the mechanisms by which TNF, and possibly also its homologue lymphotoxin α, contributes to development of pathology in rheumatoid arthritis and Crohn disease and in animal models like experimental autoimmune encephalomyelitis is unclear. Possibilities include regulation of vascular adhesion molecules enabling leukocyte movement into tissues or direct cytokine-mediated effector functions such as mediation of tissue damage. Here we show that administration of a TNF receptor (55 kDa)-IgG fusion protein prevented clinical signs of actively induced experimental autoimmune encephalomyelitis. Significantly, the total number of CD4^+ T lymphocytes isolated from the central nervous system of clinically healthy treated versus diseased control animals was comparable. By using a CD45 congenic model of passively transferred experimental autoimmune encephalomyelitis to enable tracking of myelin basic protein-specific effector T lymphocytes, prevention of clinical signs of disease was again demonstrated in treated animals but without quantitative or qualitative impediment to the movement of autoreactive T lymphocytes to and within the central nervous system. Thus, despite the uninterrupted movement of specific T lymphocytes into the target tissue, subsequent disease development was blocked. This provides compelling evidence for a direct effector role of TNF/lymphotoxin α in autoimmune tissue damage.

  16. Tumor Necrosis Factor Receptor-associated Protein 1 (TRAP1) Mutation and TRAP1 Inhibitor Gamitrinib-triphenylphosphonium (G-TPP) Induce a Forkhead Box O (FOXO)-dependent Cell Protective Signal from Mitochondria.

    Science.gov (United States)

    Kim, Hyunjin; Yang, Jinsung; Kim, Min Ju; Choi, Sekyu; Chung, Ju-Ryung; Kim, Jong-Min; Yoo, Young Hyun; Chung, Jongkyeong; Koh, Hyongjong

    2016-01-22

    TRAP1 (tumor necrosis factor receptor-associated protein 1), a mitochondrial Hsp90 family chaperone, has been identified as a critical regulator of cell survival and bioenergetics in tumor cells. To discover novel signaling networks regulated by TRAP1, we generated Drosophila TRAP1 mutants. The mutants successfully developed into adults and produced fertile progeny, showing that TRAP1 is dispensable in development and reproduction. Surprisingly, mutation or knockdown of TRAP1 markedly enhanced Drosophila survival under oxidative stress. Moreover, TRAP1 mutation ameliorated mitochondrial dysfunction and dopaminergic (DA) neuron loss induced by deletion of a familial Parkinson disease gene PINK1 (Pten-induced kinase 1) in Drosophila. Gamitrinib-triphenylphosphonium, a mitochondria-targeted Hsp90 inhibitor that increases cell death in HeLa and MCF7 cells, consistently inhibited cell death induced by oxidative stress and mitochondrial dysfunction induced by PINK1 mutation in mouse embryonic fibroblast cells and DA cell models such as SH-SY5Y and SN4741 cells. Additionally, gamitrinib-triphenylphosphonium also suppressed the defective locomotive activity and DA neuron loss in Drosophila PINK1 null mutants. In further genetic analyses, we showed enhanced expression of Thor, a downstream target gene of transcription factor FOXO, in TRAP1 mutants. Furthermore, deletion of FOXO almost nullified the protective roles of TRAP1 mutation against oxidative stress and PINK1 mutation. These results strongly suggest that inhibition of the mitochondrial chaperone TRAP1 generates a retrograde cell protective signal from mitochondria to the nucleus in a FOXO-dependent manner. PMID:26631731

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

    Science.gov (United States)

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

    1998-01-01

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

  18. Insulin-like growth factor 1 receptor and p38 mitogen-activated protein kinase signals inversely regulate signal transducer and activator of transcription 3 activity to control human dental pulp stem cell quiescence, propagation, and differentiation.

    Science.gov (United States)

    Vandomme, Jerome; Touil, Yasmine; Ostyn, Pauline; Olejnik, Cecile; Flamenco, Pilar; El Machhour, Raja; Segard, Pascaline; Masselot, Bernadette; Bailliez, Yves; Formstecher, Pierre; Polakowska, Renata

    2014-04-15

    Dental pulp stem cells (DPSCs) remain quiescent until activated in response to severe dental pulp damage. Once activated, they exit quiescence and enter regenerative odontogenesis, producing reparative dentin. The factors and signaling molecules that control the quiescence/activation and commitment to differentiation of human DPSCs are not known. In this study, we determined that the inhibition of insulin-like growth factor 1 receptor (IGF-1R) and p38 mitogen-activated protein kinase (p38 MAPK) signaling commonly activates DPSCs and promotes their exit from the G0 phase of the cell cycle as well as from the pyronin Y(low) stem cell compartment. The inhibition of these two pathways, however, inversely determines DPSC fate. In contrast to p38 MAPK inhibitors, IGF-1R inhibitors enhance dental pulp cell sphere-forming capacity and reduce the cells' colony-forming capacity without inducing cell death. The inverse cellular changes initiated by IGF-1R and p38 MAPK inhibitors were accompanied by inverse changes in the levels of active signal transducer and activator of transcription 3 (STAT3) factor, inactive glycogen synthase kinase 3, and matrix extracellular phosphoglycoprotein, a marker of early odontoblast differentiation. Our data suggest that there is cross talk between the IGF-1R and p38 MAPK signaling pathways in DPSCs and that the signals provided by these pathways converge at STAT3 and inversely regulate its activity to maintain quiescence or to promote self-renewal and differentiation of the cells. We propose a working model that explains the possible interactions between IGF-1R and p38 MAPK at the molecular level and describes the cellular consequences of these interactions. This model may inspire further fundamental study and stimulate research on the clinical applications of DPSC in cellular therapy and tissue regeneration. PMID:24266654

  19. Insulin-Like Growth Factor 1 Receptor and p38 Mitogen-Activated Protein Kinase Signals Inversely Regulate Signal Transducer and Activator of Transcription 3 Activity to Control Human Dental Pulp Stem Cell Quiescence, Propagation, and Differentiation

    Science.gov (United States)

    Vandomme, Jerome; Touil, Yasmine; Ostyn, Pauline; Olejnik, Cecile; Flamenco, Pilar; El Machhour, Raja; Segard, Pascaline; Masselot, Bernadette; Bailliez, Yves; Formstecher, Pierre

    2014-01-01

    Dental pulp stem cells (DPSCs) remain quiescent until activated in response to severe dental pulp damage. Once activated, they exit quiescence and enter regenerative odontogenesis, producing reparative dentin. The factors and signaling molecules that control the quiescence/activation and commitment to differentiation of human DPSCs are not known. In this study, we determined that the inhibition of insulin-like growth factor 1 receptor (IGF-1R) and p38 mitogen-activated protein kinase (p38 MAPK) signaling commonly activates DPSCs and promotes their exit from the G0 phase of the cell cycle as well as from the pyronin Ylow stem cell compartment. The inhibition of these two pathways, however, inversely determines DPSC fate. In contrast to p38 MAPK inhibitors, IGF-1R inhibitors enhance dental pulp cell sphere-forming capacity and reduce the cells' colony-forming capacity without inducing cell death. The inverse cellular changes initiated by IGF-1R and p38 MAPK inhibitors were accompanied by inverse changes in the levels of active signal transducer and activator of transcription 3 (STAT3) factor, inactive glycogen synthase kinase 3, and matrix extracellular phosphoglycoprotein, a marker of early odontoblast differentiation. Our data suggest that there is cross talk between the IGF-1R and p38 MAPK signaling pathways in DPSCs and that the signals provided by these pathways converge at STAT3 and inversely regulate its activity to maintain quiescence or to promote self-renewal and differentiation of the cells. We propose a working model that explains the possible interactions between IGF-1R and p38 MAPK at the molecular level and describes the cellular consequences of these interactions. This model may inspire further fundamental study and stimulate research on the clinical applications of DPSC in cellular therapy and tissue regeneration. PMID:24266654

  20. A Comprehensive Nuclear Receptor Network for Breast Cancer Cells

    Directory of Open Access Journals (Sweden)

    Ralf Kittler

    2013-02-01

    Full Text Available In breast cancer, nuclear receptors (NRs play a prominent role in governing gene expression, have prognostic utility, and are therapeutic targets. We built a regulatory map for 24 NRs, six chromatin state markers, and 14 breast-cancer-associated transcription factors (TFs that are expressed in the breast cancer cell line MCF-7. The resulting network reveals a highly interconnected regulatory matrix where extensive crosstalk occurs among NRs and other breast -cancer-associated TFs. We show that large numbers of factors are coordinately bound to highly occupied target regions throughout the genome, and these regions are associated with active chromatin state and hormone-responsive gene expression. This network also provides a framework for stratifying and predicting patient outcomes, and we use it to show that the peroxisome proliferator-activated receptor delta binds to a set of genes also regulated by the retinoic acid receptors and whose expression is associated with poor prognosis in breast cancer.

  1. Insulin-Like Growth Factor-Type 1 Receptor Inhibitor NVP-AEW541 Enhances Radiosensitivity of PTEN Wild-Type but Not PTEN-Deficient Human Prostate Cancer Cells

    International Nuclear Information System (INIS)

    Purpose: During the past decade, many clinical trials with both monoclonal antibodies and small molecules that target the insulin-like growth factor-type 1 receptor (IGF-1R) have been launched. Despite the important role of IGF-1R signaling in radioresistance, studies of such agents in combination with radiotherapy are lagging behind. Therefore, the aim of this study was to investigate the effect of the small molecule IGF-1R kinase inhibitor NVP-AEW541 on the intrinsic radioresistance of prostate cancer cells. Methods and Materials: The effect of NVP-AEW541 on cell proliferation, cell viability, IGF-1R signaling, radiosensitivity, cell cycle distribution, and double strand break repair was determined in three human prostate cancer cell lines (PC3, DU145, 22Rv1). Moreover, the importance of the PTEN pathway status was explored by means of transfection experiments with constitutively active Akt or inactive kinase-dead Akt. Results: NVP-AEW541 inhibited cell proliferation and decreased cell viability in a time-and dose-dependent manner in all three cell lines. Radiosensitization was observed in the PTEN wild-type cell lines DU145 and 22Rv1 but not in the PTEN-deficient PC3 cell line. NVP-AEW541-induced radiosensitization coincided with downregulation of phospho-Akt levels and high levels of residual double strand breaks. The importance of PTEN status in the radiosensitization effect was confirmed by transfection experiments with constitutively active Akt or inactive kinase-dead Akt. Conclusions: NVP-AEW541 enhances the effect of ionizing radiation in PTEN wild-type, but not in PTEN-deficient, prostate cancer cells. Proper patient selection based on the PTEN status of the tumor will be critical to the achievement of optimal results in clinical trials in which the combination of radiotherapy and this IGF-1R inhibitor is being explored.

  2. Vascular endothelial growth factor induces anti‑Müllerian hormone receptor 2 overexpression in ovarian granulosa cells of in vitro fertilization/intracytoplasmic sperm injection patients.

    Science.gov (United States)

    Fang, Yanqiu; Lu, Xiaodan; Liu, Lei; Lin, Xiuying; Sun, Munan; Fu, Jianhua; Xu, Shufen; Tan, Yan

    2016-06-01

    Misregulation of vascular endothelial growth factor A (VEGF‑A) has been implicated in numerous types of ovarian disease, such as polycystic ovarian syndrome, ovarian hyperstimulation syndrome, endometriosis and ovarian cancer. VEGF regulates blood vessel permeability and angiogenesis. In our previous study, VEGF‑regulated gene expression was profiled in the uterus of a transgenic mouse model with repressed VEGF expression, which indicated that VEGF is an important regulator in controlling gene expression in the uterus. The anti‑Müllerian hormone (AMH) is expressed by ovarian granulosa cells (GCs) and acts through its type 2 receptor, AMH receptor 2 (AMHR2). Serum AMH levels are used to predict ovarian reserves and the small antral follicles contribute markedly to the serum AMH level. AMH recruits primordial follicles and inhibits excessive follicular development by follicular stimulating hormone (FSH). However, AMH may be influenced by suppression of gonadotrophin secretion and VEGF inhibition. In the current study, human primary ovarian GCs were isolated from ovarian follicle fluid of in vitro fertilization/intracytoplasmic sperm injection cycles (IVF/ICSI). It was identified that the FSH receptor was consistently expressed in the isolated cells. VEGF‑A treatment stimulated AMHR2 overexpression at the gene and protein levels. In addition, VEGF induced AMHR2 expression on the surface of the isolated GCs from mature follicles. The VEGF treatment was also performed in an ovarian granulosa‑like cell line, KGN. AMH and AMHR2 are co‑expressed in normal GCs; however, as a result of VEGF misregulation, AMHR2 overexpression increases AMH binding, which may attenuate follicular or oocyte maturation. However, the associated function and underlying mechanism requires further investigation. PMID:27109000

  3. Stimulation of glucose uptake by transforming growth factor β: evidence for the requirement of epidermal growth factor-receptor activation

    International Nuclear Information System (INIS)

    Transforming growth factor β (TGF-β), derived from human platelets, stimulates the uptake of 2-deoxyglucose by cultured cell monolayers 2- to 4-fold. Stimulation can be detected as early as 30 min with as little as 0.1 ng of TGF-β per ml and maximal effects can be obtained at 2 hr with 1 ng of the growth factor per ml. TGF-β-induced stimulation of sugar uptake is enhanced by the co-addition of platelet-derived growth factor (10 ng/ml) or epidermal growth factor (EGF, 1 ng/ml). The NR-6 variant of mouse 3T3 cells, which lack EGF receptors, is not stimulated by TGF-β. Antisera to EGF receptors that block 125I-labeled EGF binding also inhibit TGF-β stimulation of 2-deoxyglucose uptake, although 125I-labeled TGF-β binding remains unimpaired. In contrast, antisera to the EGF receptor, which do not block EGF binding, have no measurable effect on the TGF-β-stimulated uptake of 2-deoxyglucose. The authors confirm that the receptor for TGF-β is distinct from the receptor for EGF and the authors conclude that TGF-β stimulation of 2-deoxyglucose uptake requires the co-activation of the EGF receptor kinase system

  4. Molecular cloning and expression of an additional epidermal growth factor receptor-related gene

    International Nuclear Information System (INIS)

    Epidermal growth factor (EGF), transforming growth factor α (TGF-α), and amphiregulin are structurally and functionally related growth regulatory proteins. These secreted polypeptides all bind to the 170-kDa cell-surface EGF receptor, activating its intrinsic kinase activity. However, amphiregulin exhibits different activities than EGF and TGF-α in a number of biological assays. Amphiregulin only partially competes with EGF for binding EGF receptor, and amphiregulin does not induce anchorage-independent growth of normal rat kidney cells (NRK) in the presence of TGF-β. Amphiregulin also appears to abrogate the stimulatory effect of TGF-α on the growth of several aggressive epithelial carcinomas that over-express EGF receptor. These findings suggest that amphiregulin may interact with a separate receptor in certain cell types. Here the authors report the cloning of another member of the human EGF receptor (HER) family of receptor tyrosine kinases, which were named HER3/ERRB3. The cDNA was isolated from a human carcinoma cell line, and its 6-kilobase transcript was identified in various human tissues. They have generated peptide-specific antisera that recognizes the 160-kDa HER3 protein when transiently expressed in COS cells. These reagents will allow us to determine whether HER3 binds amphiregulin or other growth regulatory proteins and what role HER3 protein plays in the regulation of cell growth

  5. An antagonist of the platelet-activating factor receptor inhibits adherence of both nontypeable Haemophilus influenzae and Streptococcus pneumoniae to cultured human bronchial epithelial cells exposed to cigarette smoke

    Directory of Open Access Journals (Sweden)

    Shukla SD

    2016-07-01

    Full Text Available Shakti D Shukla,1,* Rory L Fairbairn,1,* David A Gell,1 Roger D Latham,1 Sukhwinder S Sohal,1,2 Eugene H Walters,1 Ronan F O’Toole11Breathe Well Centre, School of Medicine, Faculty of Health, University of Tasmania, Hobart, TAS, Australia; 2School of Health Sciences, Faculty of Health, University of Tasmania, Launceston, TAS, Australia*These authors contributed equally to this workBackground: COPD is emerging as the third largest cause of human mortality worldwide after heart disease and stroke. Tobacco smoking, the primary risk factor for the development of COPD, induces increased expression of platelet-activating factor receptor (PAFr in the lung epithelium. Nontypeable Haemophilus influenzae (NTHi and Streptococcus pneumoniae adhere to PAFr on the luminal surface of human respiratory tract epithelial cells.Objective: To investigate PAFr as a potential drug target for the prevention of infections caused by the main bacterial drivers of acute exacerbations in COPD patients, NTHi and S. pneumoniae.Methods: Human bronchial epithelial BEAS-2B cells were exposed to cigarette smoke extract (CSE. PAFr expression levels were determined using immunocytochemistry and quantitative polymerase chain reaction. The epithelial cells were challenged with either NTHi or S. pneumoniae labeled with fluorescein isothiocyanate, and bacterial adhesion was measured using immunofluorescence. The effect of a well-evaluated antagonist of PAFr, WEB-2086, on binding of the bacterial pathogens to BEAS-2B cells was then assessed. In silico studies of the tertiary structure of PAFr and the binding pocket for PAF and its antagonist WEB-2086 were undertaken.Results: PAFr expression by bronchial epithelial cells was upregulated by CSE, and significantly associated with increased bacterial adhesion. WEB-2086 reduced the epithelial adhesion by both NTHi and S. pneumoniae to levels observed for non-CSE-exposed cells. Furthermore, it was nontoxic toward the bronchial epithelial

  6. Pulmonary proteases in the cystic fibrosis lung induce interleukin 8 expression from bronchial epithelial cells via a heme/meprin/epidermal growth factor receptor/Toll-like receptor pathway.

    LENUS (Irish Health Repository)

    Cosgrove, Sonya

    2012-02-01

    A high intrapulmonary protease burden is characteristic of cystic fibrosis (CF), and the resulting dysregulation of the protease\\/anti-protease balance has serious implications for inflammation in the CF lung. Because of this inflammation, micro-bleeds can occur releasing hemoglobin into the lung. The aim of this study was to investigate the effect of the protease-rich environment of the CF lung on human hemoglobin and to assess the proinflammatory effect of heme on CF bronchial epithelium. Here, we show that the Pseudomonas proteases (Pseudomonas elastase and alkaline protease) and the neutrophil proteases (neutrophil elastase (NE) and proteinase-3) are capable of almost complete degradation of hemoglobin in vitro but that NE is the predominant protease that cleaves hemoglobin in vivo in CF bronchoalveolar lavage fluid. One of the effects of this is the release of heme, and in this study we show that heme stimulates IL-8 and IL-10 protein production from DeltaF508 CFBE41o(-) bronchial epithelial cells. In addition, heme-induced IL-8 expression utilizes a novel pathway involving meprin, EGF receptor, and MyD88. Meprin levels are elevated in CF cell lines and bronchial brushings, thus adding to the proinflammatory milieu. Interestingly, alpha(1)-antitrypsin, in addition to its ability to neutralize NE and protease-3, can also bind heme and neutralize heme-induced IL-8 from CFBE41o(-) cells. This study illustrates the proinflammatory effects of micro-bleeds in the CF lung, the process by which this occurs, and a potential therapeutic intervention.

  7. Pulmonary Proteases in the Cystic Fibrosis Lung Induce Interleukin 8 Expression from Bronchial Epithelial Cells via a Heme/Meprin/Epidermal Growth Factor Receptor/Toll-like Receptor Pathway.

    LENUS (Irish Health Repository)

    Cosgrove, Sonya

    2011-03-04

    A high intrapulmonary protease burden is characteristic of cystic fibrosis (CF), and the resulting dysregulation of the protease\\/anti-protease balance has serious implications for inflammation in the CF lung. Because of this inflammation, micro-bleeds can occur releasing hemoglobin into the lung. The aim of this study was to investigate the effect of the protease-rich environment of the CF lung on human hemoglobin and to assess the proinflammatory effect of heme on CF bronchial epithelium. Here, we show that the Pseudomonas proteases (Pseudomonas elastase and alkaline protease) and the neutrophil proteases (neutrophil elastase (NE) and proteinase-3) are capable of almost complete degradation of hemoglobin in vitro but that NE is the predominant protease that cleaves hemoglobin in vivo in CF bronchoalveolar lavage fluid. One of the effects of this is the release of heme, and in this study we show that heme stimulates IL-8 and IL-10 protein production from ΔF508 CFBE41o(-) bronchial epithelial cells. In addition, heme-induced IL-8 expression utilizes a novel pathway involving meprin, EGF receptor, and MyD88. Meprin levels are elevated in CF cell lines and bronchial brushings, thus adding to the proinflammatory milieu. Interestingly, α(1)-antitrypsin, in addition to its ability to neutralize NE and protease-3, can also bind heme and neutralize heme-induced IL-8 from CFBE41o(-) cells. This study illustrates the proinflammatory effects of micro-bleeds in the CF lung, the process by which this occurs, and a potential therapeutic intervention.

  8. Dopamine receptor repertoire of human granulosa cells

    Directory of Open Access Journals (Sweden)

    Kunz Lars

    2007-10-01

    Full Text Available Abstract Background High levels of dopamine (DA were described in human ovary and recently evidence for DA receptors in granulosa and luteal cells has been provided, as well. However, neither the full repertoire of ovarian receptors for DA, nor their specific role, is established. Human granulosa cells (GCs derived from women undergoing in vitro fertilization (IVF are an adequate model for endocrine cells of the follicle and the corpus luteum and were therefore employed in an attempt to decipher their DA receptor repertoire and functionality. Methods Cells were obtained from patients undergoing IVF and examined using cDNA-array, RT-PCR, Western blotting and immunocytochemistry. In addition, calcium measurements (with FLUO-4 were employed. Expression of two DA receptors was also examined by in-situ hybridization in rat ovary. Effects of DA on cell viability and cell volume were studied by using an ATP assay and an electronic cell counter system. Results We found members of the two DA receptor families (D1- and D2 -like associated with different signaling pathways in human GCs, namely D1 (as expected and D5 (both are Gs coupled and linked to cAMP increase and D2, D4 (Gi/Gq coupled and linked to IP3/DAG. D3 was not found. The presence of the trophic hormone hCG (10 IU/ml in the culture medium for several days did not alter mRNA (semiquantitative RT-PCR or protein levels (immunocytochemistry/Western blotting of D1,2,4,5 DA receptors. Expression of prototype receptors for the two families, D1 and D2, was furthermore shown in rat granulosa and luteal cells by in situ hybridization. Among the DA receptors found in human GCs, D2 expression was marked both at mRNA and protein levels and it was therefore further studied. Results of additional RT-PCR and Western blots showed two splice variants (D2L, D2S. Irrespective of these variants, D2 proved to be functional, as DA raised intracellular calcium levels. This calcium mobilizing effect of DA was observed

  9. Phosphoinositide 3-kinase/Akt Pathway Mediates Fip1-like1-platelet-derived Growth Factor Receptor α-induced Cell Infiltration and Activation: Possible Molecular Mechanism for the Malignant Phenotype of Chronic Eosinophilic Leukemia

    Directory of Open Access Journals (Sweden)

    Bin Li

    2015-01-01

    Full Text Available The fip1-like1/platelet-derived growth factor receptor-α fusion gene (F/P is responsible for 14-60% cases of hypereosinophilia syndrome (HES, also known as F/P-positive chronic eosinophilic leukemia (F/P(+ CEL. The major pathogenesis of F/P(+ CEL is known to involve migration and activation of mast cells and eosinophils, leading to severe multi-organ dysfunction, but the mechanism was still unclear. Phosphoinositide 3-kinase (PI3K and serine-threonine protein kinase Akt have been reported to be targets of F/P in the F/P-promoted cell proliferation. They are extensively involved in the migration and adhesion of hematopoietic stem/progenitor cells, and also control cell invasion in some leukemias. The PI3K/Akt pathway is involved in eosinophil/neutrophil activation and infiltration; its possible role in regulating F/P induced cytotoxicity and upregulation of A4-integrin in eosinophils, and inducing eosinophil activation through controlling F/P-induced Nuclear factor-kB activity. Akt was recently shown to be stimulated by F/P, synergistically with stem cell factor, resulting in the induction of MCs migration and excessive activation. PI3K/Akt pathway is also a principal mediator of interleukin-5 (IL-5-induced signal transduction promoting eosinophil trafficking and degranulation, whereas IL-5 is a necessary cytokine for F/P-mediated CEL development. We, therefore, propose the hypothesis that the PI3K/Akt pathway might be vital downstream of F/P to induce target cell activation and tissue infiltration, resulting in the malignant phenotype seen in F/P(+ CEL.

  10. The cell surface organisation of the Notch-1 receptor

    OpenAIRE

    Weisshuhn, Philip Christian; Handford, PA; Redfield, C.

    2014-01-01

    The Notch receptor family plays a key role in development and disease. In cancer, Notch can act either as an oncogene or as a tumour suppressor, and possibly as a cancer stem-cell factor. Whereas most research has focused on downstream signalling events, little is known about the cell surface organisation of Notch and its ligands. The extracellular part of Notch consists mainly of 36 epidermal growth factor-like domains (EGF-domains), many of which bind calcium. Studies have shown that tandem...

  11. Secreted phospholipase A2-IIA-induced a phenotype of activated microglia in BV-2 cells requires epidermal growth factor receptor transactivation and proHB-EGF shedding

    Directory of Open Access Journals (Sweden)

    Martín Rubén

    2012-07-01

    Full Text Available Abstract Background Activation of microglia, the primary component of the innate immune response in the brain, is a hallmark of neuroinflammation in neurodegenerative disorders, including Alzheimer’s disease (AD and other pathological conditions such as stroke or CNS infection. In response to a variety of insults, microglial cells produce high levels of inflammatory cytokines that are often involved in neuronal injury, and play an important role in the recognition, engulfment, and clearance of apoptotic cells and/or invading microbes. Secreted phospholipase A2-IIA (sPLA2-IIA, an enzyme that interacts with cells involved in the systemic immune/inflammatory response, has been found up-regulated in the cerebrospinal fluid and brain of AD patients. However, despite several approaches, its functions in mediating CNS inflammation remain unknown. In the present study, the role of sPLA2-IIA was examined by investigating its direct effects on microglial cells. Methods Primary and immortalized microglial cells were stimulated by sPLA2-IIA in order to characterize the cytokine-like actions of the phospholipase. The hallmarks of activated microglia analyzed include: mitogenic response, phagocytic capabilities and induction of inflammatory mediators. In addition, we studied several of the potential molecular mechanisms involved in those events. Results The direct exposure of microglial cells to sPLA2-IIA stimulated, in a time- and dose-dependent manner, their phagocytic and proliferative capabilities. sPLA2-IIA also triggered the synthesis of the inflammatory proteins COX-2 and TNFα. In addition, EGFR phosphorylation and shedding of the membrane-anchored heparin-binding EGF-like growth factor (pro-HB-EGF ectodomain, as well as a rapid activation/phosphorylation of the classical survival proteins ERK, P70S6K and rS6 were induced upon sPLA2-IIA treatment. We further demonstrated that the presence of an EGFR inhibitor (AG1478, a matrix metalloproteinase

  12. In vitro characterization of an iodine-125 labeled anti-epidermal growth factor receptor murine monoclonal antibody (MAB-425) in human high grade glioma cells: Binding, uptake, transport and localization

    International Nuclear Information System (INIS)

    The aim of this study was to determine intracellular accumulation and possible nuclear translocation of 125I-labeled murine monoclonal antibody (MAb) 425 in human high grade glioma cells following internalization of this antibody, a prerequisite for the induction of radiotoxic effects. Four human high grade glioma cell lines known to express epidermal growth factor receptor (EGF-R) and a colorectal carcinoma cell line with negligible EGF-R expression were incubated for various time periods with a saturating concentration of 125I-MAb 425. No measurable intranuclear uptake of radioactivity was detected within an incubation period of less than 6 hr. After an incubation of 24-28 hr, only 0.5-2% of the internalized radioactivity was detected in the nuclear fraction. It may be possible to inhibit 125I-MAb 425 degradation with the addition of chloroquine. Overall, the data indicate that the major portion of the 125I-MAb 425 is degraded following internalization. Inhibition of lysosomal activity results in a significant increase in intracellular, but more importantly, intranuclear accumulation of 125I-MAb 425. Since radioactivity is released from the glioma cells following 125I-MAb 425 internalization, discontinuous gel electrophoresis was performed to determine the nature of the released cell products. The cell supernatants were examined at 0, 24 and 48 hr post incubation to determine the nature of any cell-associated radioactivity released from the cell surface or interior. A protein band corresponding to a molecular weight of 167 kDa was detected in all cell supernatants. Parallel electrophoretic gels were processed for autoradiographic studies in order to indicate corresponding radioactive components. In addition, immunostaining by Western blot with peroxidase-labeled goat anti-mouse antibody was performed to confirm the antibody nature of the protein bands

  13. In vitro characterization of an iodine-125 labeled anti-epidermal growth factor receptor murine monoclonal antibody (MAB-425) in human high grade glioma cells: Binding, uptake, transport and localization

    Energy Technology Data Exchange (ETDEWEB)

    Emrich, J.G.

    1993-01-01

    The aim of this study was to determine intracellular accumulation and possible nuclear translocation of [sup 125]I-labeled murine monoclonal antibody (MAb) 425 in human high grade glioma cells following internalization of this antibody, a prerequisite for the induction of radiotoxic effects. Four human high grade glioma cell lines known to express epidermal growth factor receptor (EGF-R) and a colorectal carcinoma cell line with negligible EGF-R expression were incubated for various time periods with a saturating concentration of [sup 125]I-MAb 425. No measurable intranuclear uptake of radioactivity was detected within an incubation period of less than 6 hr. After an incubation of 24-28 hr, only 0.5-2% of the internalized radioactivity was detected in the nuclear fraction. It may be possible to inhibit [sup 125]I-MAb 425 degradation with the addition of chloroquine. Overall, the data indicate that the major portion of the [sup 125]I-MAb 425 is degraded following internalization. Inhibition of lysosomal activity results in a significant increase in intracellular, but more importantly, intranuclear accumulation of [sup 125]I-MAb 425. Since radioactivity is released from the glioma cells following [sup 125]I-MAb 425 internalization, discontinuous gel electrophoresis was performed to determine the nature of the released cell products. The cell supernatants were examined at 0, 24 and 48 hr post incubation to determine the nature of any cell-associated radioactivity released from the cell surface or interior. A protein band corresponding to a molecular weight of 167 kDa was detected in all cell supernatants. Parallel electrophoretic gels were processed for autoradiographic studies in order to indicate corresponding radioactive components. In addition, immunostaining by Western blot with peroxidase-labeled goat anti-mouse antibody was performed to confirm the antibody nature of the protein bands.

  14. Green Tea Epigallocatechin Gallate Exhibits Anticancer Effect in Human Pancreatic Carcinoma Cells via the Inhibition of Both Focal Adhesion Kinase and Insulin-Like Growth Factor-I Receptor

    Directory of Open Access Journals (Sweden)

    Hoang Anh Vu

    2010-01-01

    Full Text Available The exact molecular mechanism by which epigallocatechin gallate (EGCG suppresses human pancreatic cancer cell proliferation is unclear. We show here that EGCG-treated pancreatic cancer cells AsPC-1 and BxPC-3 decrease cell adhesion ability on micro-pattern dots, accompanied by dephosphorylations of both focal adhesion kinase (FAK and insulin-like growth factor-1 receptor (IGF-1R whereas retained the activations of mitogen-activated protein kinase and mammalian target of rapamycin. The growth of AsPC-1 and BxPC-3 cells can be significantly suppressed by EGCG treatment alone in a dose-dependent manner. At a dose of 100 μM which completely abolishes activations of FAK and IGF-1R, EGCG suppresses more than 50% of cell proliferation without evidence of apoptosis analyzed by PARP cleavage. Finally, the MEK1/2 inhibitor U0126 enhances growth-suppressive effect of EGCG. Our data suggests that blocking FAK and IGF-1R by EGCG could prove valuable for targeted therapy, which can be used in combination with other therapies, for pancreatic cancer.

  15. Tyrosine kinase signalling in breast cancer: Epidermal growth factor receptor - convergence point for signal integration and diversification

    International Nuclear Information System (INIS)

    Cross-communication between different signalling systems is critical for the integration of multiple and changing environmental influences on individual cells. The epidermal growth factor receptor (EGFR) has been identified as a key element in the complex signalling network that is utilized by various classes of cell-surface receptors. This nonclassical mode of signalling system cross-talk, in distinction to receptor activation induced by cognate ligands, has been termed 'signal transactivation'. With the EGFR as the convergence point and distribution focus, this scenario may involve signals emitted by other members of the tyrosine kinase family, cytokine receptors, ion channels, G-protein-coupled receptors and integrins

  16. Hepatic Aryl Hydrocarbon Receptor Attenuates Fibroblast Growth Factor 21 Expression.

    Science.gov (United States)

    Girer, Nathaniel G; Murray, Iain A; Omiecinski, Curtis J; Perdew, Gary H

    2016-07-15

    The Aryl hydrocarbon receptor (AHR) is a ligand-activated transcription factor involved in many physiological processes. Several studies indicate that AHR is also involved in energy homeostasis. Fibroblast growth factor 21 (FGF21) is an important regulator of the fasting and feeding responses. When administered to various genetic and diet-induced mouse models of obesity, FGF21 can attenuate obesity-associated morbidities. Here, we explore the role of AHR in hepatic Fgf21 expression through the use of a conditional, hepatocyte-targeted AHR knock-out mouse model (Cre(Alb)Ahr(Fx/Fx)). Compared with the congenic parental strain (Ahr(Fx/Fx)), non-fasted Cre(Alb)Ahr(Fx/Fx) mice exhibit a 4-fold increase in hepatic Fgf21 expression, as well as elevated expression of the FGF21-target gene Igfbp1 Furthermore, in vivo agonist activation of AHR reduces hepatic Fgf21 expression during a fast. The Fgf21 promoter contains several putative dioxin response elements (DREs). Using EMSA, we demonstrate that the AHR-ARNT heterodimer binds to a specific DRE that overlaps binding sequences for peroxisome proliferator-activated receptor α (PPARα), carbohydrate response element-binding protein (ChREBP), and cAMP response element-binding protein, hepatocyte specific (CREBH). In addition, we reveal that agonist-activated AHR impairs PPARα-, ChREBP-, and CREBH-mediated promoter activity in Hepa-1 cells. Accordingly, agonist treatment in Hepa-1 cells ablates potent ER stress-driven Fgf21 expression, and pre-treatment with AHR antagonist blocks this effect. Finally, we show that pre-treatment of primary human hepatocytes with AHR agonist diminishes PPARα-, glucose-, and ER stress-driven induction of FGF21 expression, indicating the effect is not mouse-specific. Together, our data show that AHR contributes to hepatic energy homeostasis, partly through the regulation of FGF21 expression and signaling. PMID:27226639

  17. 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...... process which appears to involve clustering of these receptors, transduce the signal for response to TNF into the cell's interior....

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

    International Nuclear Information System (INIS)

    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 chromatograph