WorldWideScience

Sample records for factor egf signaling

  1. Ovarian cancer cell heparan sulfate 6-O-sulfotransferases regulate an angiogenic program induced by heparin-binding epidermal growth factor (EGF)-like growth factor/EGF receptor signaling.

    Science.gov (United States)

    Cole, Claire L; Rushton, Graham; Jayson, Gordon C; Avizienyte, Egle

    2014-04-11

    Heparan sulfate (HS) is a component of cell surface and extracellular matrix proteoglycans that regulates numerous signaling pathways by binding and activating multiple growth factors and chemokines. The amount and pattern of HS sulfation are key determinants for the assembly of the trimolecular, HS-growth factor-receptor, signaling complex. Here we demonstrate that HS 6-O-sulfotransferases 1 and 2 (HS6ST-1 and HS6ST-2), which perform sulfation at 6-O position in glucosamine in HS, impact ovarian cancer angiogenesis through the HS-dependent HB-EGF/EGFR axis that subsequently modulates the expression of multiple angiogenic cytokines. Down-regulation of HS6ST-1 or HS6ST-2 in human ovarian cancer cell lines results in 30-50% reduction in glucosamine 6-O-sulfate levels in HS, impairing HB-EGF-dependent EGFR signaling and diminishing FGF2, IL-6, and IL-8 mRNA and protein levels in cancer cells. These cancer cell-related changes reduce endothelial cell signaling and tubule formation in vitro. In vivo, the development of subcutaneous tumor nodules with reduced 6-O-sulfation is significantly delayed at the initial stages of tumor establishment with further reduction in angiogenesis occurring throughout tumor growth. Our results show that in addition to the critical role that 6-O-sulfate moieties play in angiogenic cytokine activation, HS 6-O-sulfation level, determined by the expression of HS6ST isoforms in ovarian cancer cells, is a major regulator of angiogenic program in ovarian cancer cells impacting HB-EGF signaling and subsequent expression of angiogenic cytokines by cancer cells.

  2. Transgenic Soybean Production of Bioactive Human Epidermal Growth Factor (EGF.

    Directory of Open Access Journals (Sweden)

    Yonghua He

    Full Text Available Necrotizing enterocolitis (NEC is a devastating condition of premature infants that results from the gut microbiome invading immature intestinal tissues. This results in a life-threatening disease that is frequently treated with the surgical removal of diseased and dead tissues. Epidermal growth factor (EGF, typically found in bodily fluids, such as amniotic fluid, salvia and mother's breast milk, is an intestinotrophic growth factor and may reduce the onset of NEC in premature infants. We have produced human EGF in soybean seeds to levels biologically relevant and demonstrated its comparable activity to commercially available EGF. Transgenic soybean seeds expressing a seed-specific codon optimized gene encoding of the human EGF protein with an added ER signal tag at the N' terminal were produced. Seven independent lines were grown to homozygous and found to accumulate a range of 6.7 +/- 3.1 to 129.0 +/- 36.7 μg EGF/g of dry soybean seed. Proteomic and immunoblot analysis indicates that the inserted EGF is the same as the human EGF protein. Phosphorylation and immunohistochemical assays on the EGF receptor in HeLa cells indicate the EGF protein produced in soybean seed is bioactive and comparable to commercially available human EGF. This work demonstrates the feasibility of using soybean seeds as a biofactory to produce therapeutic agents in a soymilk delivery platform.

  3. Non-Ligand-Induced Dimerization is Sufficient to Initiate the Signalling and Endocytosis of EGF Receptor

    OpenAIRE

    Kourouniotis, George; Wang, Yi; Pennock, Steven; Chen, Xinmei; Wang, Zhixiang

    2016-01-01

    The binding of epidermal growth factor (EGF) to EGF receptor (EGFR) stimulates cell mitogenesis and survival through various signalling cascades. EGF also stimulates rapid EGFR endocytosis and its eventual degradation in lysosomes. The immediate events induced by ligand binding include receptor dimerization, activation of intrinsic tyrosine kinase and autophosphorylation. However, in spite of intensified efforts, the results regarding the roles of these events in EGFR signalling and internali...

  4. DEPENDENCE OF PPAR LIGAND-INDUCED MAPK SIGNALING ON EPIDERMAL GROWTH FACTOR RECEPTOR TRANSACTIVATION HEPARIN-BINDING EGF CLEAVAGE MEDIATES ZINC-INDUCED EGF RECEPTOR PHOSPHORYLATION

    Science.gov (United States)

    Peroxisome proliferator-activated receptors (PPARs) are nuclear hormone receptors that function as ligand-activated transcription factors regulating lipid metabolism and homeostasis. In addition to their ability to regulate PPAR-mediated gene transcription, PPARalpha and gamma li...

  5. [Dependence of EGF receptor and STAT factor activation on redox of A431 cells].

    Science.gov (United States)

    Gonchar, I V; Burova, E B; Dorosh, V N; Gamaleĭ, I A; Nikol'skiĭ, N N

    2003-01-01

    Reactive oxygen species (ROS) were established to play an important role in cellular signaling as second messengers by integrating different pathways. Recently, we showed that EGF initiated a rapid tyrosine phosphorylation of both EGF-receptor and STAT factors with simultaneous increase in the intracellular ROS level. Now, we have investigated the effect of intracellular red-ox state on EGF- and H2O2-induced activation of EGF receptor, STAT1 and STAT3. We demonstrated that the pretreatment of A431 cells with antioxidant N-acetyl-L-cysteine (NAC) partly reduced the level of EGF-induced phosphorylation of proteins under investigation. Besides, H2O2-induced activation of EGF receptor, and STAT factors was fully prevented by NAC pretreatment. The inhibition of ROS generation by DPI declined EGF-dependent activation of EGF receptor and STAT factors to basal level. Our results demonstrate the essential role of cellular red-ox status in the modulation of EGF-mediated activation of receptor and STAT factors. We have postulated that EGF-induced ROS generation is a very important initial event promoting physiological activation of EGF receptor and subsequent STAT factor activation.

  6. EGF stimulates the activation of EGF receptors and the selective activation of major signaling pathways during mitosis.

    Science.gov (United States)

    Wee, Ping; Shi, Huaiping; Jiang, Jennifer; Wang, Yuluan; Wang, Zhixiang

    2015-03-01

    Mitosis and epidermal growth factor (EGF) receptor (EGFR) are both targets for cancer therapy. The role of EGFR signaling in mitosis has been rarely studied and poorly understood. The limited studies indicate that the activation of EGFR and downstream signaling pathways is mostly inhibited during mitosis. However, we recently showed that EGFR is phosphorylated in response to EGF stimulation in mitosis. Here we studied EGF-induced EGFR activation and the activation of major signaling pathways downstream of EGFR during mitosis. We showed that EGFR was strongly activated by EGF during mitosis as all the five major tyrosine residues including Y992, Y1045, Y1068, Y1086, and Y1173 were phosphorylated to a level similar to that in the interphase. We further showed that the activated EGFR is able to selectively activate some downstream signaling pathways while avoiding others. Activated EGFR is able to activate PI3K and AKT2, but not AKT1, which may be responsible for the observed effects of EGF against nocodazole-induced cell death. Activated EGFR is also able to activate c-Src, c-Cbl and PLC-γ1 during mitosis. However, activated EGFR is unable to activate ERK1/2 and their downstream substrates RSK and Elk-1. While it activated Ras, EGFR failed to fully activate Raf-1 in mitosis due to the lack of phosphorylation at Y341 and the lack of dephosphorylation at pS259. We conclude that contrary to the dogma, EGFR is activated by EGF during mitosis. Moreover, EGFR-mediated cell signaling is regulated differently from the interphase to specifically serve the needs of the cell in mitosis.

  7. A switch role of Src in the biphasic EGF signaling of ER-negative breast cancer cells.

    Directory of Open Access Journals (Sweden)

    XinTian Zhang

    Full Text Available It is well established that epidermal growth factor (EGF is a potent mitogen in cells expressing EGF receptor (EGFR. However, a body of evidence indicated that the effects of mitogenic EGF signaling exhibit a non-monotonic, or biphasic dose response curve; EGF at low concentrations elicits a mitogenic signaling pathway to stimulate cell proliferation while at high concentrations, EGF inhibits cell growth. However, the molecular mechanism underlying this paradoxical effect of EGF on cell proliferation remains largely unknown. Here, we investigated the molecular mechanisms underlying the biphasic EGF signaling in ER-negative breast cancer MDA-MB-231 and MDA-MB-436 cells, both of which express endogenous EGFR. We found that EGF at low concentrations induced the phosphorylation of the Src-Y416 residue, an event to activate Src, while at high concentrations allowed Src-Y527 phosphorylation that inactivates Src. EGF at 10 ng/ml also induced phosphorylation of the MAPK/ERK and activated cyclin D1 promoter activity through the Src/EGFR/STAT5 pathways but not at a higher concentration (500 ng/ml. Our results thus demonstrated that Src functions as a switch of EGF signaling depending on concentrations of EGF.

  8. Pilose antler peptide protects osteoblasts from inflammatory and oxidative injury through EGF/EGFR signaling.

    Science.gov (United States)

    Chunhui, Yang; Wenjun, Cai; Hui, Wen; Liquan, Sha; Changwei, Zhao; Tianzhu, Zhang; Wenhai, Zhao

    2017-02-16

    Epidermal growth factor (EGF)/EFG receptor (EGFR) signaling plays an important role in the osteoblastogenesis. The potential effects of pilose antler peptide (PAP) on osteoblast cell damages was investigated in our present study through EGF/EGFR signaling. In MC3T3-E1 osteoblastic cells, PAP treatment significantly inhibited the production of inflammatory cytokines by decreasing the levels of serum proinflammatory cytokines interleukin-1β (IL-1β), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α). PAP treatment also alleviated the oxidative responses as indicated by increased activities of catalase (SOD) and decreased levels of malondialdehyde (MDA). EGF inhibition, by siRNA knockdown, almost abolished PAP-induced osteoblast cytoprotection against inflammation and oxidant stress. Further, our results showed that PAP stimulated the nuclear erythroid factor 2-related factor 2 (Nrf2)2/heme oxygenase-1(HO-1) signaling, and inhibited the activation of uclear factor kappa B (NF-κB) pathway in MC3T3-E1 cells. On the other hand, EGF siRNA knockdown inhibited PAP-induced cytoprotection, which decreased the expression of Nrf-2, HO-1 and increased the level of p-NF-κBp65, p-IκBα in MC3T3-E1 cells. Thus, our research demonstrated that PAP protects osteoblasts from inflammatory and oxidative injury through EGF/EGFR signaling.

  9. Epidermal growth factor-like domain-containing protein 7 (EGFL7 enhances EGF receptor-AKT signaling, epithelial-mesenchymal transition, and metastasis of gastric cancer cells.

    Directory of Open Access Journals (Sweden)

    Bai-Hua Luo

    Full Text Available Epidermal growth factor-like domain-containing protein 7 (EGFL7 is upregulated in human epithelial tumors and so is a potential biomarker for malignancy. Indeed, previous studies have shown that high EGFL7 expression promotes infiltration and metastasis of gastric carcinoma. The epithelial-mesenchymal transition (EMT initiates the metastatic cascade and endows cancer cells with invasive and migratory capacity; however, it is not known if EGFL7 promotes metastasis by triggering EMT. We found that EGFL7 was overexpressed in multiple human gastric cancer (GC cell lines and that overexpression promoted cell invasion and migration as revealed by scratch wound and transwell migration assays. Conversely, shRNA-mediated EGFL7 knockdown reduced invasion and migration. Furthermore, EGFL7-overexpressing cells grew into larger tumors and were more likely to metastasize to the liver compared to underexpressing CG cells following subcutaneous injection in mice. EGFL7 overexpression protected GC cell lines against anoikis, providing a plausible mechanism for this enhanced metastatic capacity. In excised human gastric tumors, expression of EGFL7 was positively correlated with expression levels of the mesenchymal marker vimentin and the EMT-associated transcription repressor Snail, and negatively correlated with expression of the epithelial cell marker E-cadherin. In GC cell lines, EGFL7 knockdown reversed morphological signs of EMT and decreased both vimentin and Snail expression. In addition, EGFL7 overexpression promoted EGF receptor (EGFR and protein kinase B (AKT phospho-activation, effects markedly suppressed by the EGFR tyrosine kinase inhibitor AG1478. Moreover, AG1478 also reduced the elevated invasive and migratory capacity of GC cell lines overexpressing EGFL7. Collectively, these results strongly suggest that EGFL7 promotes metastasis by activating EMT through an EGFR-AKT-Snail signaling pathway. Disruption of EGFL7-EGFR-AKT-Snail signaling may a

  10. The roles of EGF and Wnt signaling during patterning of the C. elegans Bγ/δ Equivalence Group

    OpenAIRE

    Sternberg Paul W; Seah Adeline

    2009-01-01

    Abstract Background During development, different signaling pathways interact to specify cell fate by regulating transcription factors necessary for fate specification and morphogenesis. In Caenorhabditis elegans, the EGF-Ras and Wnt signaling pathways have been shown to interact to specify cell fate in three equivalence groups: the vulval precursor cells (VPCs), the hook competence group (HCG) and P11/12. In the VPCs, HCG and P11/12 pair, EGF and Wnt signaling positively regulate different H...

  11. Non-Ligand-Induced Dimerization is Sufficient to Initiate the Signalling and Endocytosis of EGF Receptor

    Directory of Open Access Journals (Sweden)

    George Kourouniotis

    2016-07-01

    Full Text Available The binding of epidermal growth factor (EGF to EGF receptor (EGFR stimulates cell mitogenesis and survival through various signalling cascades. EGF also stimulates rapid EGFR endocytosis and its eventual degradation in lysosomes. The immediate events induced by ligand binding include receptor dimerization, activation of intrinsic tyrosine kinase and autophosphorylation. However, in spite of intensified efforts, the results regarding the roles of these events in EGFR signalling and internalization is still very controversial. In this study, we constructed a chimeric EGFR by replacing its extracellular domain with leucine zipper (LZ and tagged a green fluorescent protein (GFP at its C-terminus. We showed that the chimeric LZ-EGFR-GFP was constitutively dimerized. The LZ-EGFR-GFP dimer autophosphorylated each of its five well-defined C-terminal tyrosine residues as the ligand-induced EGFR dimer does. Phosphorylated LZ-EGFR-GFP was localized to both the plasma membrane and endosomes, suggesting it is capable of endocytosis. We also showed that LZ-EGFR-GFP activated major signalling proteins including Src homology collagen-like (Shc, extracellular signal-regulated kinase (ERK and Akt. Moreover, LZ-EGFR-GFP was able to stimulate cell proliferation. These results indicate that non-ligand induced dimerization is sufficient to activate EGFR and initiate cell signalling and EGFR endocytosis. We conclude that receptor dimerization is a critical event in EGF-induced cell signalling and EGFR endocytosis.

  12. Proliferative response of fibroblasts expressing internalization-deficient epidermal growth factor (EGF) receptors is altered via differential EGF depletion effect.

    Science.gov (United States)

    Reddy, C C; Wells, A; Lauffenburger, D A

    1994-01-01

    We describe experiments comparing the proliferation responses to epidermal growth factor (EGF) by NR6 fibroblasts expressing genetically engineered epidermal growth factor receptors (EGFRs). These cells present either wild-type (WT) EGFR or a cytoplasmic domain-truncated (c'973) EGFR that exhibits a decreased ligand-induced internalization rate constant. In two distinct in vitro proliferation assays, with or without medium replenishment, we measured the specific cell proliferation rate constants and EGF depletion kinetics for both WT and c'973 cells. When EGF depletion is minimized by replenishment, the EGF concentration dependencies of the two cell types are similar, whereas when EGF depletion is not prevented, maximal proliferation of WT cells requires an initial EGF concentration that is approximately 10x that required by c'973 cells. However, when EGF depletion is accounted for, the dependencies of growth rate for the two cell types on the current EGF concentration in both assays are essentially identical. Our results demonstrate that diminished depletion of EGF from the extracellular medium is a major reason for increased mitogenic sensitivity to EGF by cells possessing internalization-deficient receptors.

  13. The expression of the epidermal growth factor (EGF) during odontogenesis:

    OpenAIRE

    Peixoto, Breno C.; Integrated Federal School of Diamantina - MG; dos Santos, Cássio R. R.; Integrated Federal School of Diamantina - MG; Canuto, Conceição E.; Integrated Federal School of Diamantina - MG

    2010-01-01

    The objective of this study was to verify, through the technique of Immunohistochemistry, the expression of theepidermal growth factor (EGF) in the odontogenesis of the first upper molar in Mus musculus mice, relating it tothe microscopic morphologic analysis. The sample consisted of 23 animals, with age from the 13th day of intrauterinelife to the 20th day of postnatal life. The results showed EGF being expressed by several tissues and cellsparticipating of the odontogenesis. However the den...

  14. Tl(I) and Tl(III) alter the expression of EGF-dependent signals and cyclins required for pheochromocytoma (PC12) cell-cycle resumption and progression.

    Science.gov (United States)

    Pino, María T L; Verstraeten, Sandra V

    2015-08-01

    The effects of thallium [Tl(I) and Tl(III)] on the PC12 cell cycle were evaluated without (EGF(-)) or with (EGF(+)) media supplementation with epidermal growth factor (EGF). The following markers of cell-cycle phases were analyzed: cyclin D1 (G1 ); E2F-1, cyclin E and cytosolic p21 (G1 →S transition); nuclear PCNA and cyclin A (S); and cyclin B1 (G2). The amount of cells in each phase and the activation of the signaling cascade triggered by EGF were also analyzed. Tl(I) and Tl(III) (5-100 μM) caused dissimilar effects on PC12 cell proliferation. In EGF(-) cells, Tl(I) increased the expression of G1 →S transition markers and nuclear PCNA, without affecting cyclin A or cyclin B1. In addition to those, cyclin B1 was also increased in EGF(+) cells. In EGF(-) cells, Tl(III) increased the expression of cyclin D1, all the G1→S and S phase markers and cyclin B1. In EGF(+) cells, Tl(III) increased cyclin D1 expression and decreased all the markers of G1 →S transition and the S phase. Even when these cations did not induce the activation of EGF receptor (EGFR) in EGF(-) cells, they promoted the phosphorylation of ERK1/2 and Akt. In the presence of EGF, the cations anticipated EGFR phosphorylation without affecting the kinetics of EGF-dependent ERK1/2 and Akt phosphorylation. Altogether, results indicate that Tl(I) promoted cell proliferation in both EGF(-) and EGF(+) cells. In contrast, Tl(III) promoted the proliferation of EGF(-) cells but delayed it in EGF(+) cells, which may be related to the toxic effects of this cation in PC12 cells. Copyright © 2014 John Wiley & Sons, Ltd.

  15. EGFR signaling downstream of EGF regulates migration, invasion, and MMP secretion of immortalized cells derived from human ameloblastoma.

    Science.gov (United States)

    da Rosa, Marina Rolo Pinheiro; Falcão, Aline Semblano Carreira; Fuzii, Hellen Thais; da Silva Kataoka, Maria Sueli; Ribeiro, André L R; Boccardo, Enrique; de Siqueira, Adriane Sousa; Jaeger, Ruy G; de Jesus Viana Pinheiro, João; de Melo Alves Júnior, Sérgio

    2014-11-01

    Ameloblastoma is an odontogenic tumor characterized by local invasiveness and frequent recurrence. The surrounding stroma, composed of different cell types and extracellular matrix (ECM), may influence ameloblastoma invasive behavior. Furthermore, tumor and stromal cells secrete matrix metalloproteases (MMPs), which, in turn, can modulate the matrix and promote the release of ECM-bound growth factors. Among these growth factors, epidermal growth factor (EGF) and its receptor, EGFR, have already been shown to stimulate MMP synthesis, suggesting that an interdependent mechanism, involving MMP activity and growth factors release, may contribute to tumor invasiveness. The aim of this study was to evaluate the effects of the EGF/EGFR signaling pathway on migration, invasion, and MMP activity, in a primary cell line derived from human ameloblastoma. We established and characterized a primary cell line (AME-1) from a human ameloblastoma sample. This cell line was transduced with human papillomavirus type 16 (HPV16) E6/E7 oncogenes, generating the AME-HPV continuous cell line. EGF, MMP2, and MMP9 expression in ameloblastoma biopsies and in the AME-HPV cell line was analyzed by immunohistochemistry and immunofluorescence, respectively. Migratory activity of EGF-treated AME-HPV cells was investigated using monolayer wound assays and Transwell chambers. EGF-induced invasion was assessed in Boyden chambers coated with Matrigel. Conditioned medium from EGF-treated cells was subjected to zymography. EGFR expression in AME-HPV cells was silenced by small interfering RNA (siRNA), to verify the relationship between this receptor and MMP secretion. Ameloblastoma samples and AME-HPV cells expressed EGF, EGFR, MMP2, and MMP9. AME-HPV cells treated with EGF showed increased rates of migration and invasion, as well as enhanced MMP2 and MMP9 activity. EGFR knockdown decreased MMP2 and MMP9 levels in AME-HPV cells. EGFR signaling downstream of EGF probably regulates migration, invasion

  16. Neuropilin-1-dependent regulation of EGF-receptor signaling.

    Science.gov (United States)

    Rizzolio, Sabrina; Rabinowicz, Noa; Rainero, Elena; Lanzetti, Letizia; Serini, Guido; Norman, Jim; Neufeld, Gera; Tamagnone, Luca

    2012-11-15

    Neuropilin-1 (NRP1) is a coreceptor for multiple extracellular ligands. NRP1 is widely expressed in cancer cells and in advanced human tumors; however, its functional relevance and signaling mechanisms are unclear. Here, we show that NRP1 expression controls viability and proliferation of different cancer cells, independent of its short intracellular tail. We found that the extracellular domain of NRP1 interacts with the EGF receptor (EGFR) and promotes its signaling cascade elicited upon EGF or TGF-α stimulation. Upon NRP1 silencing, the ability of ligand-bound EGFR to cluster on the cell surface, internalize, and activate the downstream AKT pathway is severely impaired. EGFR is frequently activated in human tumors due to overexpression, mutation, or sustained autocrine/paracrine stimulation. Here we show that NRP1-blocking antibodies and NRP1 silencing can counteract ligand-induced EGFR activation in cancer cells. Thus our findings unveil a novel molecular mechanism by which NRP1 can control EGFR signaling and tumor growth.

  17. Phenethyl isothiocyanate suppresses EGF-stimulated SAS human oral squamous carcinoma cell invasion by targeting EGF receptor signaling.

    Science.gov (United States)

    Chen, Hui-Jye; Lin, Chung-Ming; Lee, Chao-Ying; Shih, Nai-Chen; Amagaya, Sakae; Lin, Yung-Chang; Yang, Jai-Sing

    2013-08-01

    Phenethyl isothiocyanate (PEITC) is a natural compound that is involved in chemoprevention as well as inhibition of cell growth and induction of apoptosis in several types of cancer cells. Previous studies have revealed that PEITC suppresses the invasion of AGS gastric and HT-29 colorectal cancer cells. However, the effects of PEITC on the metastasis of SAS oral cancer cells remain to be determined. Our results showed that PEITC treatment inhibited the invasion of EGF-stimulated SAS cells in a concentration-dependent manner, but appeared not to affect the cell viability. The expression and enzymatic activities of matrix metalloprotease-2 (MMP-2) and matrix metalloprotease-9 (MMP-9) were suppressed by PEITC. Concomitantly, we observed an increase in the protein expression of both tissue inhibitor of metalloproteinase-1 (TIMP-1) and -2 (TIMP-2) in treated cells. Furthermore, PEITC treatments decreased the protein phosphorylation of epidermal growth factor receptor (EGFR) and downstream signaling proteins including PDK1, PI3K (p85), AKT, phosphorylated IKK and IκB to inactivate NF-κB for the suppression of MMP-2 and MMP-9 expression. In addition, PEITC can trigger the MAPK signaling pathway through the increase in phosphorylated p38, JNK and ERK in treated cells. Our data indicate that PEITC is able to inhibit the invasion of EGF-stimulated SAS oral cancer cells by targeting EGFR and its downstream signaling molecules and finally lead to the reduced expression and enzymatic activities of both MMP-2 and MMP-9. These results suggest that PEITC is promising for the therapy of oral cancer metastasis.

  18. Modified epidermal growth factor receptor (EGFR-bearing liposomes (MRBLs are sensitive to EGF in solution.

    Directory of Open Access Journals (Sweden)

    Albert Wong

    Full Text Available Cancers often overexpress EGF and other growth factors to promote cell replication and migration. Previous work has not produced targeted drug carriers sensitive to abnormal amounts of growth factors. This work demonstrates that liposomes bearing EGF receptors covalently crosslinked to p-toluic acid or methyl-PEO(4-NHS ester (or, in short, MRBLs exhibit an increased rate of release of encapsulated drug compounds when EGF is present in solution. Furthermore, the modified EGF receptors retain the abilities to form dimers in the presence of EGF and bind specifically to EGF. These results demonstrate that MRBLs are sensitive to EGF in solution and indicate that MRBL-reconstituted modified EGF receptors, in the presence of EGF in solution, form dimers which increase MRBL permeability to encapsulated compounds.

  19. The roles of EGF and Wnt signaling during patterning of the C. elegans Bγ/δ Equivalence Group

    Directory of Open Access Journals (Sweden)

    Sternberg Paul W

    2009-12-01

    Full Text Available Abstract Background During development, different signaling pathways interact to specify cell fate by regulating transcription factors necessary for fate specification and morphogenesis. In Caenorhabditis elegans, the EGF-Ras and Wnt signaling pathways have been shown to interact to specify cell fate in three equivalence groups: the vulval precursor cells (VPCs, the hook competence group (HCG and P11/12. In the VPCs, HCG and P11/12 pair, EGF and Wnt signaling positively regulate different Hox genes, each of which also functions during fate specification. In the male, EGF-Ras signaling is required to specify the Bγ fate within the Bγ/δ equivalence pair, while Notch signaling is required for Bδ fate specification. In addition, TGF-β signaling by dbl-1/dpp controls ceh-13/labial/Hox1 expression in Bγ. Results We show that EGF-Ras signaling is required for Bγ expression of ceh-13/labial/Hox1. The transcription factors lin-1/ETS and lin-31/Forkhead, functioning downstream of the EGF pathway, as well as sur-2/MED23 (a component of the Mediator complex also control ceh-13 expression in Bγ. In addition, our results indicate that lin-44/Wnt, mom-2/Wnt and lin-17/Fz are necessary to maintain the division of Bγ along a longitudinal axis. We also show that dbl-1/dpp acts either in parallel or downstream of EGF pathway to regulate ceh-13/Hox1 expression in Bγ. Lastly, we find that a dbl-1/dpp null mutation did not cause any vulval or P12 defects and did not enhance vulval and P12 defects of reduction-of-function mutations of components of the EGF pathway. Conclusions ceh-13/labial/Hox1 expression in Bγ is regulated by the EGF pathway and downstream factors lin-1/ETS lin-31/Forkhead and sur-2/MED23. Wnt signaling is required for proper Bγ division, perhaps to orient the Bγ mitotic spindle. Our results suggest that dbl-1/dpp is not required for VPC and P12 specification, highlighting another difference among these EGF-dependent equivalence groups.

  20. Lefty blocks a subset of TGFbeta signals by antagonizing EGF-CFC coreceptors.

    Directory of Open Access Journals (Sweden)

    Simon K Cheng

    2004-02-01

    Full Text Available Members of the EGF-CFC family play essential roles in embryonic development and have been implicated in tumorigenesis. The TGFbeta signals Nodal and Vg1/GDF1, but not Activin, require EGF-CFC coreceptors to activate Activin receptors. We report that the TGFbeta signaling antagonist Lefty also acts through an EGF-CFC-dependent mechanism. Lefty inhibits Nodal and Vg1 signaling, but not Activin signaling. Lefty genetically interacts with EGF-CFC proteins and competes with Nodal for binding to these coreceptors. Chimeras between Activin and Nodal or Vg1 identify a 14 amino acid region that confers independence from EGF-CFC coreceptors and resistance to Lefty. These results indicate that coreceptors are targets for both TGFbeta agonists and antagonists and suggest that subtle sequence variations in TGFbeta signals result in greater ligand diversity.

  1. Regulation of EGF receptor signaling by the MARVEL domain-containing protein CKLFSF8.

    Science.gov (United States)

    Jin, Caining; Ding, Peiguo; Wang, Ying; Ma, Dalong

    2005-11-21

    It is known that chemokine-like factor superfamily 8 (CKLFSF8), a member of the CKLF superfamily, has four putative transmembrane regions and a MARVEL domain. Its structure is similar to TM4SF11 (plasmolipin) and widely distributed in normal tissue. However, its function is not yet known. We show here that CKLFSF8 is associated with the epidermal growth factor receptor (EGFR) and that ectopic expression of CKLFSF8 in several cell lines suppresses EGF-induced cell proliferation, whereas knockdown of CKLFSF8 by siRNA promotes cell proliferation. In cells overexpressing CKLFSF8, the initial activation of EGFR was not affected, but subsequent desensitization of EGF-induced signaling occurred rapidly. This attenuation was correlated with an increased rate of receptor endocytosis. In contrast, knockdown of CKLFSF8 by siCKLFSF8 delayed EGFR endocytosis. These results identify CKLFSF8 as a novel regulator of EGF-induced signaling and indicate that the association of EGFR with four transmembrane proteins is critical for EGFR desensitization.

  2. Cardiotoxin III suppresses MDA-MB-231 cell metastasis through the inhibition of EGF/EGFR-mediated signaling pathway.

    Science.gov (United States)

    Tsai, Pei-Chien; Hsieh, Chi-Ying; Chiu, Chien-Chih; Wang, Chih-Kuang; Chang, Long-Sen; Lin, Shinne-Ren

    2012-10-01

    Cardiotoxin III (CTX III), a basic polypeptide isolated from Naja naja atra venom, has been shown to exhibit anticancer activity. Epidermal growth factor (EGF) and its receptor, EGFR, play roles in cancer metastasis in various tumors. We use EGF as a metastatic inducer of MDA-MB-231 cells to investigate the effect of CTX III on cell migration. CTX III inhibited the EGF-induced activation of matrix metalloproteinase-9 (MMP-9), and further suppressed cell invasion and migration without obvious cellular cytotoxicity. CTX III suppressed EGF-induced nuclear factor-kappaB (NF-κB) nuclear translocation and also abrogated the EGF-induced phosphorylation of EGFR, phosphatidylinositol 3-kinase (PI3K)/Akt, and extracellular regulated kinase (ERK)1/2. In addition, CTX III similar to wortmannin (a PI3K inhibitor) and U0126 (an up-stream kinase regulating ERK1/2 inhibitor) attenuated cell migration and invasion induced by EGF. Furthermore, the EGFR inhibitor AG1478 inhibited EGF-induced MMP-9 expression, cell migration and invasion, as well as the activation of ERK1/2 and PI3K/Akt, suggesting that ERK1/2 and PI3K/Akt activation occur downstream of EGFR activation. These findings suggest that CTX III inhibited the EGF-induced invasion and migration of MDA-MB-231 cells via EGFR-dependent PI3K/Akt, ERK1/2, and NF-κB signaling, leading to the down-regulation of MMP-9 expression. These results provide a novel mechanism to explain the role of CTX III as a potent anti-metastatic agent in MDA-MB-231 cells.

  3. Egf Signaling Directs Neoblast Repopulation by Regulating Asymmetric Cell Division in Planarians.

    Science.gov (United States)

    Lei, Kai; Thi-Kim Vu, Hanh; Mohan, Ryan D; McKinney, Sean A; Seidel, Chris W; Alexander, Richard; Gotting, Kirsten; Workman, Jerry L; Sánchez Alvarado, Alejandro

    2016-08-22

    A large population of proliferative stem cells (neoblasts) is required for physiological tissue homeostasis and post-injury regeneration in planarians. Recent studies indicate that survival of a few neoblasts after sublethal irradiation results in the clonal expansion of the surviving stem cells and the eventual restoration of tissue homeostasis and regenerative capacity. However, the precise mechanisms regulating the population dynamics of neoblasts remain largely unknown. Here, we uncovered a central role for epidermal growth factor (EGF) signaling during in vivo neoblast expansion mediated by Smed-egfr-3 (egfr-3) and its putative ligand Smed-neuregulin-7 (nrg-7). Furthermore, the EGF receptor-3 protein localizes asymmetrically on the cytoplasmic membrane of neoblasts, and the ratio of asymmetric to symmetric cell divisions decreases significantly in egfr-3(RNAi) worms. Our results not only provide the first molecular evidence of asymmetric stem cell divisions in planarians, but also demonstrate that EGF signaling likely functions as an essential regulator of neoblast clonal expansion.

  4. EGF induces epithelial-mesenchymal transition through phospho-Smad2/3-Snail signaling pathway in breast cancer cells.

    Science.gov (United States)

    Kim, Jinkyoung; Kong, Jienan; Chang, Hyeyoon; Kim, Hayeon; Kim, Aeree

    2016-12-20

    Epithelial-mesenchymal transition (EMT) can contribute to tumor invasion, metastasis, and resistance to chemotherapy or hormone therapy. EMT may be induced by a variety of growth factors, such as epidermal growth factor (EGF). Most studies regarding EMT have focused on TGF-β-Smads signaling. The mechanism of EGF-induced EMT via activation of the Smad2/3 in breast cancer cells, MCF-7 and MDA-MB-231, remains unclear. The expression levels of Snail, vimentin, and fibronectin were increased by EGF treatment in a time-dependent manner, while the expression level of E-cadherin was decreased. EGF-induced nuclear co-localization of phospho-Smad2/3 and Snail and cancer cell migration were inhibited by pretreatment with an ERK1/2 inhibitor, PD98059 and a phospho-Smad2 inhibitor, SB203580. Knockdown of Smad2/3 expression suppressed EGF-induced expressions of Snail, vimentin, fibronectin, and cancer cell invasion, suggesting an acquisition of the mesenchymal and migratory phenotype in less aggressive MCF-7 cells. Moreover, MDA-MB-231 cells were shown that EGF-induced EMT, and cell invasion through ERK1/2-phospho-Smad2/3-Snail signaling pathway. We have discovered that EGF-stimulated activation of Smad2/3 upregulated several key EMT markers, inhibited E-cadherin expression, promoted EMT, enhanced migration and invasion in MCF-7 and MDA-MB-231 breast cancer cells. Identification of this molecular mechanism may provide new molecular targets for the development of therapies for metastatic breast cancer.

  5. Application of EGFP-EGF fusions to explore mechanism of endocytosis of epidermal growth factor

    Institute of Scientific and Technical Information of China (English)

    Hua JIANG; Jie ZHANG; Bi-zhi SHI; Yu-hong XU; Zong-hai LI; Jian-ren GU

    2007-01-01

    Aim: To develop a simple method for monitoring protein localization of epidermal growth factor (EGF) in living cells. Methods: Enhanced green fluorescent protein (EGFP) was used as an autofluorescent tag to label EGF ligands. SDS-PAGE and Western blot analysis were used to detect the expression of the EGFP-tagged EGF (EGFP-EGF) protein. The cell-binding and internalization activity of EGFP-EGF were analyzed by fluorescence-activated cell sorting (FACS) and confocal micro-scopy. Results: EGFP-EGF protein was expressed in Escherichia coil and purified.A cell-binding assay demonstrated that the EGFP-EGF protein could bind effi-ciently to the cells expressing EGFR. The binding and intemalization of EGFP-EGF can be visualized even at a very low concentration under confocal microscopy.The FACS-based assay for internalization activity indicated the accumulation of internalized EGFP-EGF over time. Furthermore, the results of the competition assay indicated its EGFR binding specificity. Using such a method, it does not need to label EGF with chemicals and avoid light in the experimental process. Conclusion: The fusion protein EGFP-EGF has several characters including high sensitivity, stability and convenience for manipulation, and is a powerful tool for the study of EGF endocytosis.

  6. Structural Basis for Negative Cooperativity in Growth Factor Binding to an EGF Receptor

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-09-27

    Transmembrane signaling by the epidermal growth factor receptor (EGFR) involves ligand-induced dimerization and allosteric regulation of the intracellular tyrosine kinase domain. Crystallographic studies have shown how ligand binding induces dimerization of the EGFR extracellular region but cannot explain the high-affinity and low-affinity classes of cell-surface EGF-binding sites inferred from curved Scatchard plots. From a series of crystal structures of the Drosophila EGFR extracellular region, we show here how Scatchard plot curvature arises from negatively cooperative ligand binding. The first ligand-binding event induces formation of an asymmetric dimer with only one bound ligand. The unoccupied site in this dimer is structurally restrained, leading to reduced affinity for binding of the second ligand, and thus negative cooperativity. Our results explain the cell-surface binding characteristics of EGF receptors and suggest how individual EGFR ligands might stabilize distinct dimeric species with different signaling properties.

  7. Secretion of protein and epidermal growth factor (EGF) by transplanted human pancreas.

    Science.gov (United States)

    Konturek, J W; Buesing, M; Hopt, U T; Stachura, J; Becker, H D; Konturek, S J

    1992-08-01

    Epidermal growth factor (EGF) has been localized in human salivary and Brunner's glands and found to stimulate the proliferation of gastrointestinal and pancreatic tissues in animals, but little is known about EGF in human pancreas. This study was designed to determine the distribution and release of EGF in the pancreas and to assess the secretion of EGF and protein by the transplanted human pancreas. The peroxidase antiperoxidase (PAP) immunocytochemical method with anti-hEGF showed that EGF was restricted mainly to the excretory cells lining pancreatic ducts. The EGF immunoreactivity in the pancreatic tissue averaged about 15 +/- 0.5 micrograms/g of tissue wt. The concentration and output of EGF in the pancreatic juice were, respectively, about 3.4 +/- 0.7 ng/mL and 68 + 12 ng/h in basal secretion collected from the whole pancreatic transplant. A significant increase in EGF release from this transplant started about 2 h after its reperfusion and was accompanied by a parallel increase in protein output. Injection of iv secretion (1 U/kg) resulted in a transient rise in EGF output, probably as a result of washout by increased vol flow, whereas HCCK (1 U/kg) caused more prolonged release of EGF accompanied by a marked stimulation of protein secretion. Ingestion of a mixed meal caused an immediate and sustained increment in EGF output, and protein output showed a more protracted increase, reaching its peak in the second postprandial hour. Fractionation of an extract of pancreatic juice on G-5O Sephadex superfine column revealed that EGF immunoreactivity emerged as a major peak in the same position as authentic human EGF (hEGF).(ABSTRACT TRUNCATED AT 250 WORDS)

  8. The effects of chronic administration of epidermal growth factor (EGF) to rats on the levels of endogenous EGF in the submandibular glands and kidneys

    DEFF Research Database (Denmark)

    Vinter-Jensen, Lars; Jøgensen, P E; Poulsen, Steen Seier;

    1996-01-01

    Epidermal growth factor (EGF) is mainly produced in the submandibular glands (SMG) and in the kidneys. It has recently been reported that EGF-related ligands may induce their own biosynthesis (autoinduction) in vitro. In the present paper, we investigated whether chronic systemic treatment with EGF...... influenced the amount of endogenous EGF in the SMG and kidneys. Eight-week-old female Wistar rats were treated with subcutaneous injections of placebo (n = 16) or human recombinant EGF (150 micrograms/kg per day, n = 8) for 4 weeks. Urine was sampled the last 24 h of the study period. At the time of killing......, the SMG and the kidneys were removed. The SMG was larger in the EGF-treated animals, 229.8 +/- 35.5 (mean +/- SD) mg than in the control animals, 181.7 +/- 18.1 mg (P kidneys were larger in the EGF...

  9. Temporal regulation of EGF signaling networks by the scaffold protein Shc1

    Science.gov (United States)

    Zheng, Yong; Zhang, Cunjie; Croucher, David R.; Soliman, Mohamed A.; St-Denis, Nicole; Pasculescu, Adrian; Taylor, Lorne; Tate, Stephen A.; Hardy, Rod W.; Colwill, Karen; Dai, Anna Yue; Bagshaw, Rick; Dennis, James W.; Gingras, Anne-Claude; Daly, Roger J.; Pawson, Tony

    2016-01-01

    Cell-surface receptors frequently employ scaffold proteins to recruit cytoplasmic targets, but the rationale for this is uncertain. Activated receptor tyrosine kinases, for example, engage scaffolds such as Shc1 that contain phosphotyrosine (pTyr) binding (PTB) domains. Using quantitative mass spectrometry, we find that Shc1 responds to epidermal growth factor (EGF) stimulation through multiple waves of distinct phosphorylation events and protein interactions. Following stimulation, Shc1 rapidly binds a group of proteins that activate pro-mitogenic/survival pathways dependent on recruitment of the Grb2 adaptor to Shc1 pTyr sites. Akt-mediated feedback phosphorylation of Shc1 Ser29 then recruits the Ptpn12 tyrosine phosphatase. This is followed by a sub-network of proteins involved in cytoskeletal reorganization, trafficking and signal termination that binds Shc1 with delayed kinetics, largely through the SgK269 pseudokinase/adaptor protein. Ptpn12 acts as a switch to convert Shc1 from pTyr/Grb2-based signaling to SgK269-mediated pathways that regulate cell invasion and morphogenesis. The Shc1 scaffold therefore directs the temporal flow of signaling information following EGF stimulation. PMID:23846654

  10. Epidermal growth factor (EGF) as a potential targeting agent for delivery of boron to malignant gliomas

    Energy Technology Data Exchange (ETDEWEB)

    Capala, J.; Barth, R.F.; Adams, D.M.; Bailey, M.Q.; Soloway, A.H. [Ohio State Univ., Columbus, OH (United States); Carlsson, J. [Uppsala Univ. (Sweden). Dept. of Radiation Sciences

    1994-12-31

    The majority of high grade gliomas express an amplified epidermal growth factor receptor (EGFR) gene, and this often is associated with an increase in cell surface receptor expression. The rapid internalization and degradation of EGF-EGFR complexes, as well as their high affinity make EGF a potential targeting agent for delivery of {sup 10}B to tumor cells with an amplified number of EGFR. Human glioma cells can expresses as many as 10{sup 5} {minus}10{sup 6} EGF receptors per cell, and if these could be saturated with boronated EGF, then > 10{sup 8} boron atoms would be delivered per cell. Since EGF has a comparatively low molecular weight ({approximately} 6 kD), this has allowed us to construct relatively small bioconjugates containing {approximately} 900 boron atoms per EGF molecule{sup 3}, which also had high affinity for EGFR on tumor cells. In the present study, the feasibility of using EGF receptors as a potential target for therapy of gliomas was investigated by in vivo scintigraphic studies using {sup 131}I{minus} or {sup 99m}{Tc}-labeled EGF in a rat brain tumor model. Our results indicate that intratumorally delivered boron- EGF conjugates might be useful for targeting EGFR on glioma cells if the boron containing moiety of the conjugates persisted intracellularly. Further studies are required, however, to determine if this approach can be used for BNCT of the rat glioma.

  11. The Lipocalin LPR-1 Cooperates with LIN-3/EGF Signaling To Maintain Narrow Tube Integrity in Caenorhabditis elegans.

    Science.gov (United States)

    Pu, Pu; Stone, Craig E; Burdick, Joshua T; Murray, John I; Sundaram, Meera V

    2016-12-30

    Lipocalins are secreted cup-shaped glycoproteins that bind sterols, fatty acids, and other lipophilic molecules. Lipocalins have been implicated in a wide array of processes related to lipophilic cargo transport, sequestration and signaling, and several are used as biomarkers for human disease, but the functions of most lipocalins remain poorly understood. Here we show that the C. elegans lipocalin LPR-1 is required to maintain apical membrane integrity and a continuous lumen in two narrow, unicellular tubes, the excretory duct and pore, during a period of rapid lumen elongation. LPR-1 fusion protein is expressed by the duct and pore and accumulates both intracellularly and in apical extracellular compartments, but it can also function cell non-autonomously when provided from outside of the excretory system. lpr-1 mutant defects can be rescued by increased signaling through the Epidermal growth factor (EGF) - Ras - Extracellular signal regulated kinase (ERK) pathway, which promotes the more elongated duct vs. less elongated pore tube fate. Spatial and temporal rescue experiments indicate that Ras signaling acts within the duct and pore tubes during or prior to cell fate determination to bypass the requirement for LPR-1. lpr-1 mutations did not disrupt LIN-3/EGF-dependent duct fate specification, prevent functioning of any specific LIN-3/EGF isoform, or alter LET-23/EGFR localization, and reduced signaling did not phenocopy or enhance lpr-1 mutant defects. These data suggest that LPR-1 protects lumen integrity through a LIN-3/EGF-independent mechanism, but that increased signaling upregulates some target(s) that can compensate for lpr-1 absence.

  12. Cobalamin deficiency-induced changes of epidermal growth factor (EGF)-receptor expression and EGF levels in rat spinal cord.

    Science.gov (United States)

    Mutti, Elena; Magnaghi, Valerio; Veber, Daniela; Faroni, Alessandro; Pece, Salvatore; Di Fiore, Pier Paolo; Scalabrino, Giuseppe

    2011-02-28

    We investigated the effect of cobalamin (Cbl) deficiency on epidermal growth factor receptor (EGFR) mRNA levels in the spinal cord (SC) and liver of rats made Cbl-deficient (Cbl-D) by means of total gastrectomy or a Cbl-D diet, and simultaneously measured the levels of the epidermal growth factor (EGF). Both methods of inducing Cbl deficiency decreased EGFR expression in the SC and liver. Cbl replacement treatment normalized or nearly so most of the abnormalities in EGFR expression in the totally gastrectomized (TGX) rats at different times. The EGFR-immunostaining intensity decreased in the SC white matter of the Cbl-D rats and significantly increased in that of the TGX, Cbl-treated rats. EGF levels significantly increased in liver of TGX rats and in SC of 4-month TGX rats, and the increases returned to almost normal levels after a postoperative 2-month administration of Cbl to TGX rats. These findings demonstrate that Cbl deficiency dysregulates the EGFR-EGF dyad in these tissues.

  13. Microfluidic generated EGF-gradients induce chemokinesis of transplantable retinal progenitor cells via the JAK/STAT and PI3kinase signaling pathways.

    Directory of Open Access Journals (Sweden)

    Uchenna J Unachukwu

    Full Text Available A growing number of studies are evaluating retinal progenitor cell (RPC transplantation as an approach to repair retinal degeneration and restore visual function. To advance cell-replacement strategies for a practical retinal therapy, it is important to define the molecular and biochemical mechanisms guiding RPC motility. We have analyzed RPC expression of the epidermal growth factor receptor (EGFR and evaluated whether exposure to epidermal growth factor (EGF can coordinate motogenic activity in vitro. Using Boyden chamber analysis as an initial high-throughput screen, we determined that RPC motility was optimally stimulated by EGF concentrations in the range of 20-400 ng/ml, with decreased stimulation at higher concentrations, suggesting concentration-dependence of EGF-induced motility. Using bioinformatics analysis of the EGF ligand in a retina-specific gene network pathway, we predicted a chemotactic function for EGF involving the MAPK and JAK-STAT intracellular signaling pathways. Based on targeted inhibition studies, we show that ligand binding, phosphorylation of EGFR and activation of the intracellular STAT3 and PI3kinase signaling pathways are necessary to drive RPC motility. Using engineered microfluidic devices to generate quantifiable steady-state gradients of EGF coupled with live-cell tracking, we analyzed the dynamics of individual RPC motility. Microfluidic analysis, including center of mass and maximum accumulated distance, revealed that EGF induced motility is chemokinetic with optimal activity observed in response to low concentration gradients. Our combined results show that EGFR expressing RPCs exhibit enhanced chemokinetic motility in the presence of low nanomole levels of EGF. These findings may serve to inform further studies evaluating the extent to which EGFR activity, in response to endogenous ligand, drives motility and migration of RPCs in retinal transplantation paradigms.

  14. Non-linear antigenic regions in epidermal growth factor (EGF) and transforming growth factor alpha (TGF alpha) studied by EGF-TGF alpha chimaeras.

    Science.gov (United States)

    van de Poll, M L; van Rotterdam, W; Gadellaa, M M; Stortelers, C; van Vugt, M J; van Zoelen, E J

    2000-07-01

    With the help of 16 chimaeras between human epidermal growth factor (hEGF) and human transforming growth factor alpha (hTGF alpha), a detailed analysis was performed on the epitope recognized by two polyclonal antibodies raised against hEGF, and one polyclonal antibody raised against hTGF alpha. All three antibodies recognized essentially the same antigenic site, a non-linear and conformation-dependent sequence that is located near the second and fourth disulphide-bonded cysteines and that includes the start of the B-loop beta-sheet. The epitope recognized by the anti-hEGF antibodies was further characterized using 8 chimaeras between hEGF and an EGF-repeat from Drosophila Notch and was found to include Met(21), Ala(30) and Asn(32). All three polyclonal antibodies were able to neutralize the biological activity of the respective growth factor when tested on 32D murine haematopoietic progenitor cells transfected with ErbB-1, indicating that the receptor binding domain is shielded upon binding of the antibody.

  15. Membrane lipids, EGF receptors, and intracellular signals colocalize and are polarized in epithelial cells moving directionally in a physiological electric field.

    Science.gov (United States)

    Zhao, Min; Pu, Jin; Forrester, John V; McCaig, Colin D

    2002-06-01

    Directed cell migration is essential for tissue formation, inflammation, and wound healing. Chemotaxis plays a major role in these situations and is underpinned by asymmetric intracellular signaling. Endogenous electric fields (EFs) are common where cell movement occurs, such as in wound healing, and cells respond to electric field gradients by reorienting and migrating directionally (galvanotaxis/electrotaxis). We show that a physiological EF redistributed both EGF (epidermal growth factor) receptors and detergent-insoluble membrane lipids asymmetrically, leading to cathodal polarization and enhanced activation of the MAP kinase, ERK1/2. This induced leading-edge actin polymerization in directionally migrating mammalian epithelial cells. Inhibiting the EGF receptor-MAP kinase signaling pathway significantly decreased leading edge actin asymmetry and directional migration. We propose a model in which EF-polarized membrane lipid domains and EGF receptors cause asymmetric signaling through MAP kinase, which drives directional cell migration. A comparison is made with the mechanisms underpinning chemotaxis.

  16. EGF up-regulates miR-31 through the C/EBPβ signal cascade in oral carcinoma.

    Directory of Open Access Journals (Sweden)

    Wen-Cheng Lu

    Full Text Available Oral squamous cell carcinoma (OSCC is one of the most prevalent carcinomas worldwide. MicroRNAs (miRNAs are short, non-coding RNAs that regulate gene expression and modulate physiological or pathological processes including OSCC carcinogenesis. miR-31 has been found to be up-regulated in OSCC and to act as an oncogenic miRNA. However, the molecular mechanism underlying miR-31 up-regulation in OSCC is still obscure. The activation of epidermal growth factor receptor (EGFR signaling axis plays key roles in driving oral carcinogenesis. Our screening identified that there is up-regulation of miR-31, miR-181b and miR-222 in OSCC cells following EGF treatment. Subsequent analysis showed that EGF treatment led to AKT activation, which then resulted in miR-31 up-regulation. Moreover, EGF treatment and the AKT activation induced by exogenous expression up-regulated C/EBPβ expression. The miR-31 up-regulation induced by EGF was abrogated by AKT inhibition or by the knockdown of C/EBPβ expression. In OSCC cell subclones stably overexpressing the functional isoform of C/EBPβ, miR-31 expression was up-regulated. Curcumin is a natural ingredient exhibiting anti-cancer potential. It was found that curcumin attenuated AKT activation and the up-regulation of C/EBPβ and miR-31 caused by EGF stimulation in OSCC cells. Lastly, concordance across the expression of EGFR, the expression of C/EBPβ and the expression of miR-31 in OSCC tissues was found. This study describes a novel scenario where the up-regulation of miR-31 expression in OSCC is, at least in part, a consequence of EGFR oncogenic activation. Although the AKT activation and C/EBPβ expression after EGF treatment might not be directly linked, both events are the crucial mediators underlying miR-31 up-regulation in the EGFR signaling axis.

  17. ErbB/EGF signaling and EMT in mammary development and breast cancer.

    Science.gov (United States)

    Hardy, Katharine M; Booth, Brian W; Hendrix, Mary J C; Salomon, David S; Strizzi, Luigi

    2010-06-01

    Activation of the ErbB family of receptor tyrosine kinases via cognate Epidermal Growth Factor (EGF)-like peptide ligands constitutes a major group of related signaling pathways that control proliferation, survival, angiogenesis and metastasis of breast cancer. In this respect, clinical trials with various ErbB receptor blocking antibodies and specific tyrosine kinase inhibitors have proven to be partially efficacious in the treatment of this heterogeneous disease. Induction of an embryonic program of epithelial-to-mesenchymal transition (EMT) in breast cancer, whereupon epithelial tumor cells convert to a more mesenchymal-like phenotype, facilitates the migration, intravasation, and extravasation of tumor cells during metastasis. Breast cancers which exhibit properties of EMT are highly aggressive and resistant to therapy. Activation of ErbB signaling can regulate EMT-associated invasion and migration in normal and malignant mammary epithelial cells, as well as modulating discrete stages of mammary gland development. The purpose of this review is to summarize current information regarding the role of ErbB signaling in aspects of EMT that influence epithelial cell plasticity during mammary gland development and tumorigenesis. How this information may contribute to the improvement of therapeutic approaches in breast cancer will also be addressed.

  18. EGF Receptor-Dependent Mechanism May be Involved in the Tamm–Horsfall Glycoprotein-Enhanced PMN Phagocytosis via Activating Rho Family and MAPK Signaling Pathway

    Directory of Open Access Journals (Sweden)

    Ko-Jen Li

    2014-01-01

    Full Text Available Our previous studies showed that urinary Tamm–Horsfall glycoprotein (THP potently enhanced polymorphonuclear neutrophil (PMN phagocytosis. However, the domain structure(s, signaling pathway and the intracellular events responsible for THP-enhanced PMN phagocytosis remain to be elucidated. THP was purified from normal human urine. The human promyelocytic leukemia cell line HL-60 was induced to differentiate into PMNs by all-trans retinoid acid. Pretreatment with different MAPK and PI3K inhibitors was used to delineate signaling pathways in THP-enhanced PMN phagocytosis. Phosphorylation of molecules responsible for PMN phagocytosis induced by bacterial lipopolysaccharide (LPS, THP, or human recombinant epidermal growth factor (EGF was evaluated by western blot. A p38 MAPK inhibitor, SB203580, effectively inhibited both spontaneous and LPS- and THP-induced PMN phagocytosis. Both THP and LPS enhanced the expression of the Rho family proteins Cdc42 and Rac that may lead to F-actin re-arrangement. Further studies suggested that THP and EGF enhance PMN and differentiated HL-60 cell phagocytosis in a similar pattern. Furthermore, the EGF receptor inhibitor GW2974 significantly suppressed THP- and EGF-enhanced PMN phagocytosis and p38 and ERK1/2 phosphorylation in differentiated HL-60 cells. We conclude that EGF receptor-dependent signaling may be involved in THP-enhanced PMN phagocytosis by activating Rho family and MAP kinase.

  19. Expression and purification of human epidermal growth factor (hEGF fused with GB1

    Directory of Open Access Journals (Sweden)

    Xueming Zheng

    2016-07-01

    Full Text Available Fusion expression is a promising strategy for the production of bioactive peptides in Escherichia coli. In this study, we constructed a new recombinant expression plasmid containing the coding sequence of 56-residue B1 domain of streptococcal protein G (GB1. For easy purification and cleavage of the recombinant proteins, except GB1, an engineered hexahistidine and tobacco etch virus (TEV protease recognition sites were included in the fusion sequence. Next, we cloned the coding sequence of human epidermal growth factor (hEGF into this new plasmid and produced the recombinant hEGF in E. coli. The bioactive hEGF is a 53-amino acid peptide and is stabilized by three intramolecular disulphide bonds. Compared with glutathione S-transferase, thioredoxin and small ubiquitin-related modifier, GB1 greatly improved the expression and solubility of hEGF. Moreover, the recombinant hEGF bound to the nickel nitrilotriacetic acid resin column, was easily cleaved by TEV protease and the free hEGF was released. The results showed that this new plasmid was appropriate for recombinant production of small bioactive peptides, such as hEGF, which contains a high proportion of hydrophobic residues and intramolecular disulphide linkages.

  20. Mouse Oocytes Enable LH-Induced Maturation of the Cumulus-Oocyte Complex via Promoting EGF Receptor-Dependent Signaling

    Science.gov (United States)

    Su, You-Qiang; Sugiura, Koji; Li, Qinglei; Wigglesworth, Karen; Matzuk, Martin M.; Eppig, John J.

    2010-01-01

    LH triggers the maturation of the cumulus-oocyte complex (COC), which is followed by ovulation. These ovarian follicular responses to LH are mediated by epidermal growth factor (EGF)-like growth factors produced by granulosa cells and require the participation of oocyte-derived paracrine factors. However, it is not clear how oocytes coordinate with the EGF receptor (EGFR) signaling to achieve COC maturation. The aim of the present study was to test the hypothesis that oocytes promote the expression of EGFR by cumulus cells, thus enabling them to respond to the LH-induced EGF-like peptides. Egfr mRNA and protein expression were dramatically reduced in cumulus cells of mutant mice deficient in the production of the oocyte-derived paracrine factors growth differentiation factor 9 (GDF9) and bone morphogenetic protein 15 (BMP15). Moreover, microsurgical removal of oocytes from wild-type COCs dramatically reduced expression of Egfr mRNA and protein, and these levels were restored by either coculture with oocytes or treatment with recombinant GDF9 or GDF9 plus recombinant BMP15. Blocking Sma- and Mad-related protein (SMAD)2/3 phosphorylation in vitro inhibited Egfr expression in wild-type COCs and in GDF9-treated wild-type cumulus cells, and conditional deletion of Smad2 and Smad3 genes in granulosa cells in vivo resulted in the reduction of Egfr mRNA in cumulus cells. These results indicate that oocytes promote expression of Egfr in cumulus cells, and a SMAD2/3-dependent pathway is involved in this process. At least two oocyte-derived growth factors, GDF9 and BMP15, are required for EGFR expression by cumulus cells. PMID:20382892

  1. Heparin-binding epidermal growth factor-like growth factor (HB-EGF) and proteolytic processing by a disintegrin and metalloproteinases (ADAM): a regulator of several pathways.

    Science.gov (United States)

    Taylor, S R; Markesbery, M G; Harding, P A

    2014-04-01

    HB-EGF is a member of the EGF family of ligands that is initially synthesized as a membrane-bound growth factor termed, proHB-EGF. The membrane bound proHB-EGF undergoes extensive proteolytic processing by several metalloproteinases capable of stimulating cellular proliferation. Soluble, mature HB-EGF binds to and activates EGF receptors. HB-EGF is a critical molecular component to a number of normal physiological processes including but not limited to tissue injury and wound healing, reproduction, angiogenesis and recently, adipogenesis. Misexpression of HB-EGF is linked to tumor formation and cancer including hepatocellular, pancreatic, gastric, breast, colon and melanoma, gliomas and glioblastomas. HB-EGF is a likely tool for therapeutic approaches to enhance treatment of injuries as well as a target for prevention of several cancers and obesity. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. The EGF signaling pathway influences cell migration and the secretion of metalloproteinases by myoepithelial cells in pleomorphic adenoma.

    Science.gov (United States)

    Navarini, Natalia Festugatto; Araújo, Vera Cavalcanti de; Brown, Amy Louise; Passador-Santos, Fabrício; Souza, Isabela Fernandes de; Napimoga, Marcelo Henrique; Araújo, Ney Soares; Martinez, Elizabeth Ferreira

    2015-01-01

    During tumor development, benign neoplastic cells are influenced by the expression of cytokines, growth factors, and proteases present in the tumor microenvironment. Epidermal growth factor (EGF) is the most studied growth factor and is considered important for cell proliferation and migration. Metalloproteinases (MMPs) are also involved in tumor progression. The present study aimed to analyze the proliferation, viability and migration index of pleomorphic adenoma myoepithelial cells, in addition to the secretion of MMPs with EGF supplementation. Benign myoepithelial cells were cultured with two different EGF doses (5 and 10 ng/ml), and the influence of EGF on cell proliferation and viability, using trypan blue and MTT assays, respectively, after 24, 48, and 72 h, was evaluated. To analyze cellular morphology, hematoxylin-eosin staining and indirect immunofluorescence using the anti-vimentin antibody, was performed. In vitro migration assays were performed in Transwell chambers with an 8-μm pore covered with Matrigel and supplemented with 5 or 10 ng/ml of EGF, after 96 h. After 4 days of cell culture, ELISA was performed to determine the MMP-2 and MMP-13 levels. One-way analysis of variance (ANOVA) with post hoc Tukey test was applied, with a significance level of 0.05. The results revealed that EGF influences myoepithelial cell morphology, without alteration of proliferation and viability. The migration assay showed that EGF increased the mean index from 16 % in the control group to 40 and 76 % for 5 and 10 ng/ml of EGF, respectively. ELISA revealed that when the cells were supplemented with either of the EGF doses, an increase in MMP-2 levels was observed when compared with the control group (C). This study concludes that EGF aids in the production of MMP-2, which favors the dissolution of the basement membrane, contributing to cell migration and tumor progression, hence permitting contact between the myoepithelial cells and stroma.

  3. Epidermal growth factor (EGF)-induced corneal epithelial wound healing through nuclear factor κB subtype-regulated CCCTC binding factor (CTCF) activation.

    Science.gov (United States)

    Wang, Ling; Wu, Xiaolin; Shi, Ting; Lu, Luo

    2013-08-23

    Epidermal growth factor (EGF) plays an important role in corneal epithelial migration and proliferation to improve the wound healing process. This study aimed to understand the role of NFκB in EGF-induced corneal epithelial wound healing through regulation of CTCF activity, which plays important roles in cell motility and migration to promote wound healing. The effect of NFκB p50 on corneal epithelial wound healing was investigated by comparing the eyes of wild-type and p50 knockout mice. We found that there was a significant retardation in corneal epithelial wound healing in the corneas of p50 knockout mice. Wound closure rates were measured in human corneal epithelial cells transfected with an NFκB activation-sensitive CTCF expression construct to demonstrate the effect of human CTCF expression under the control of EGF-induced NFκB activation on wound healing. EGF stimulation activated NFκB, which directly triggered the expression of the exogenous human CTCF in transfected cells and, subsequently, promoted human corneal epithelial cell motility, migration, and wound healing. Overexpression of CTCF in corneal epithelial cells and mouse corneas significantly enhanced the wound healing process. Furthermore, the effect of overexpressing NFκB p50 in corneal epithelial cells on the promotion of wound healing was abolished by knockdown of CTCF with CTCF-specific shRNA. Thus, a direct regulatory relationship between EGF-induced NFκB p50 and CTCF activation affecting corneal epithelial wound healing has been established, indicating that CTCF is, indeed, a NFκB p50-targeted and effective gene product in the core transcriptional network downstream from the growth factor-induced NFκB signaling pathway.

  4. Identification of heparin-binding EGF-like growth factor (HB-EGF as a biomarker for lysophosphatidic acid receptor type 1 (LPA1 activation in human breast and prostate cancers.

    Directory of Open Access Journals (Sweden)

    Marion David

    Full Text Available Lysophosphatidic acid (LPA is a natural bioactive lipid with growth factor-like functions due to activation of a series of six G protein-coupled receptors (LPA₁₋₆. LPA receptor type 1 (LPA₁ signaling influences the pathophysiology of many diseases including cancer, obesity, rheumatoid arthritis, as well as lung, liver and kidney fibrosis. Therefore, LPA₁ is an attractive therapeutic target. However, most mammalian cells co-express multiple LPA receptors whose co-activation impairs the validation of target inhibition in patients because of missing LPA receptor-specific biomarkers. LPA₁ is known to induce IL-6 and IL-8 secretion, as also do LPA₂ and LPA₃. In this work, we first determined the LPA induced early-gene expression profile in three unrelated human cancer cell lines expressing different patterns of LPA receptors (PC3: LPA₁,₂,₆; MDA-MB-231: LPA1,2; MCF-7: LPA₂,₆. Among the set of genes upregulated by LPA only in LPA₁-expressing cells, we validated by QPCR and ELISA that upregulation of heparin-binding EGF-like growth factor (HB-EGF was inhibited by LPA₁-₃ antagonists (Ki16425, Debio0719. Upregulation and downregulation of HB-EGF mRNA was confirmed in vitro in human MDA-B02 breast cancer cells stably overexpressing LPA₁ (MDA-B02/LPA₁ and downregulated for LPA₁ (MDA-B02/shLPA1, respectively. At a clinical level, we quantified the expression of LPA₁ and HB-EGF by QPCR in primary tumors of a cohort of 234 breast cancer patients and found a significantly higher expression of HB-EGF in breast tumors expressing high levels of LPA₁. We also generated human xenograph prostate tumors in mice injected with PC3 cells and found that a five-day treatment with Ki16425 significantly decreased both HB-EGF mRNA expression at the primary tumor site and circulating human HB-EGF concentrations in serum. All together our results demonstrate that HB-EGF is a new and relevant biomarker with potentially high value in

  5. Androgen receptor in Sertoli cells regulates DNA double-strand break repair and chromosomal synapsis of spermatocytes partially through intercellular EGF-EGFR signaling.

    Science.gov (United States)

    Chen, Su-Ren; Hao, Xiao-Xia; Zhang, Yan; Deng, Shou-Long; Wang, Zhi-Peng; Wang, Yu-Qian; Wang, Xiu-Xia; Liu, Yi-Xun

    2016-04-01

    Spermatogenesis does not progress beyond the pachytene stages of meiosis in Sertoli cell-specific AR knockout (SCARKO) mice. However, further evidence of meiotic arrest and underlying paracrine signals in SCARKO testes is still lacking. We utilized co-immunostaining of meiotic surface spreads to examine the key events during meiotic prophase I. SCARKO spermatocytes exhibited a failure in chromosomal synapsis observed by SCP1/SCP3 double-staining and CREST foci quantification. In addition, DNA double-strand breaks (DSBs) were formed but were not repaired in the mutant spermatocytes, as revealed by γ-H2AX staining and DNA-dependent protein kinase (DNA-PK) activity examination. The later stages of DSB repair, such as the accumulation of the RAD51 strand exchange protein and the localization of mismatch repair protein MLH1, were correspondingly altered in SCARKO spermatocytes. Notably, the expression of factors that guide RAD51 loading onto sites of DSBs, including TEX15, BRCA1/2 and PALB2, was severely impaired when either AR was down-regulated or EGF was up-regulated. We observed that some ligands in the epidermal growth factor (EGF) family were over-expressed in SCARKO Sertoli cells and that some receptors in the EGF receptor (EGFR) family were ectopically activated in the mutant spermatocytes. When EGF-EGFR signaling was repressed to approximately normal by the specific inhibitor AG1478 in the cultured SCARKO testis tissues, the arrested meiosis was partially rescued, and functional haploid cells were generated. Based on these data, we propose that AR in Sertoli cells regulates DSB repair and chromosomal synapsis of spermatocytes partially through proper intercellular EGF-EGFR signaling.

  6. Fungiform papilla pattern: EGF regulates inter-papilla lingual epithelium and decreases papilla number by means of PI3K/Akt, MEK/ERK, and p38 MAPK signaling.

    Science.gov (United States)

    Liu, Hong-Xiang; Henson, Bradley S; Zhou, Yanqiu; D'Silva, Nisha J; Mistretta, Charlotte M

    2008-09-01

    Fungiform papillae are epithelial taste organs that form on the tongue, requiring differentiation of papillae and inter-papilla epithelium. We tested roles of epidermal growth factor (EGF) and the receptor EGFR in papilla development. Developmentally, EGF was localized within and between papillae whereas EGFR was progressively restricted to inter-papilla epithelium. In tongue cultures, EGF decreased papillae and increased cell proliferation in inter-papilla epithelium in a concentration-dependent manner, whereas EGFR inhibitor increased and fused papillae. EGF preincubation could over-ride disruption of Shh signaling that ordinarily would effect a doubling of fungiform papillae. With EGF-induced activation of EGFR, we demonstrated phosphorylation in PI3K/Akt, MEK/ERK, and p38 MAPK pathways; with pathway inhibitors (LY294002, U0126, SB203580) the EGF-mediated decrease in papillae was reversed, and synergistic actions were shown. Thus, EGF/EGFR signaling by means of PI3K/Akt, MEK/ERK, and p38 MAPK contributes to epithelial cell proliferation between papillae; this biases against papilla differentiation and reduces numbers of papillae.

  7. Regulated ADAM17-dependent EGF family ligand release by substrate-selecting signaling pathways.

    Science.gov (United States)

    Dang, Michelle; Armbruster, Nicole; Miller, Miles A; Cermeno, Efrain; Hartmann, Monika; Bell, George W; Root, David E; Lauffenburger, Douglas A; Lodish, Harvey F; Herrlich, Andreas

    2013-06-11

    Ectodomain cleavage of cell-surface proteins by A disintegrin and metalloproteinases (ADAMs) is highly regulated, and its dysregulation has been linked to many diseases. ADAM10 and ADAM17 cleave most disease-relevant substrates. Broad-spectrum metalloprotease inhibitors have failed clinically, and targeting the cleavage of a specific substrate has remained impossible. It is therefore necessary to identify signaling intermediates that determine substrate specificity of cleavage. We show here that phorbol ester or angiotensin II-induced proteolytic release of EGF family members may not require a significant increase in ADAM17 protease activity. Rather, inducers activate a signaling pathway using PKC-α and the PKC-regulated protein phosphatase 1 inhibitor 14D that is required for ADAM17 cleavage of TGF-α, heparin-binding EGF, and amphiregulin. A second pathway involving PKC-δ is required for neuregulin (NRG) cleavage, and, indeed, PKC-δ phosphorylation of serine 286 in the NRG cytosolic domain is essential for induced NRG cleavage. Thus, signaling-mediated substrate selection is clearly distinct from regulation of enzyme activity, an important mechanism that offers itself for application in disease.

  8. ErbB-2 blockade and prenyltransferase inhibition alter epidermal growth factor and epidermal growth factor receptor trafficking and enhance (111)In-DTPA-hEGF Auger electron radiation therapy.

    Science.gov (United States)

    Cornelissen, Bart; Darbar, Sonali; Hernandez, Rebecca; Kersemans, Veerle; Tullis, Iain; Barber, Paul R; Smart, Sean; Vojnovic, Borivoj; Reilly, Raymond; Vallis, Katherine A

    2011-05-01

    The intracellular distribution of Auger electron-emitting radiopharmaceuticals is a determinant of cytotoxicity. However, the mechanisms by which these agents are routed through the cell are ill understood. The aim of this study was to investigate how trafficking of (111)In-labeled human epidermal growth factor ((111)In-DTPA-hEGF) relates to that of the EGF receptor (EGFR) and whether coadministration of agents that modulate EGFR signaling alters the efficacy of (111)In-DTPA-hEGF. The spatiotemporal interaction between AlexaFluor488-EGF (AF488-EGF) and Cy3-conjugated anti-EGFR antibody (Cy3-anti-EGFR) was studied in the breast cancer cell line MDA-MB-468 using fluorescence resonance energy transfer and 2-photon fluorescence lifetime imaging. (111)In internalization and nuclear fractionation assays were performed to investigate the effect of the ErbB-2-blocking antibody trastuzumab and a prenyltransferase inhibitor, L-778,123, on the subcellular localization of (111)In-DTPA-hEGF in MDA-MB-468 (1.3 × 10(6) EGFR per cell; ErbB-2 negative) and 231-H2N (0.2 × 10(6) EGFR per cell; 0.4 × 10(5) ErbB-2 per cell) cell lines. The cytotoxicity of (111)In-DTPA-hEGF (0-64 nM) plus trastuzumab (0-50 μg/mL) or L-778,123 (0-22.5 μM) was measured using clonogenic assays in a panel of breast cancer cell lines that express different levels of EGFR and ErB-2. Clonogenic survival data were used to calculate combination indices. Tumor growth inhibition was measured in vivo in 231-H2N xenograft-bearing mice treated with (111)In-DTPA-hEGF plus trastuzumab or L-788,123. Using fluorescence resonance energy transfer, we showed that EGF interacts with EGFR in the cytoplasm and nucleus after internalization of the ligand-receptor complex in MDA-MB-468 cells. Nuclear localization of (111)In-DTPA-hEGF is enhanced by trastuzumab and L-788,123. Trastuzumab and L-788,123 sensitized 231-H2N cells to (111)In-DTPA-hEGF. Nuclear localization and cytotoxicity of (111)In-DTPA-hEGF were significantly

  9. Opposite effects of the p52shc/p46shc and p66shc splicing isoforms on the EGF receptor-MAP kinase-fos signalling pathway

    DEFF Research Database (Denmark)

    Migliaccio, E; Mele, S; Salcini, A E;

    1997-01-01

    66shc expression varies from cell type to cell type. p66shc differs from p52shc/p46shc in its inability to transform mouse fibroblasts in vitro. Like p52shc/p46shc, p66shc is tyrosine-phosphorylated upon epidermal growth factor (EGF) stimulation, binds to activated EGF receptors (EGFRs) and forms...... on the EGFR-MAP kinase and other signalling pathways that control fos promoter activity. Regulation of p66shc expression might, therefore, influence the cellular response to growth factors.......Shc proteins are targets of activated tyrosine kinases and are implicated in the transmission of activation signals to Ras. The p46shc and p52shc isoforms share a C-terminal SH2 domain, a proline- and glycine-rich region (collagen homologous region 1; CH1) and a N-terminal PTB domain. We have...

  10. Surface composition gradients of immobilized cell signaling molecules. Epidermal growth factor on gold

    Energy Technology Data Exchange (ETDEWEB)

    Wang Qian [Department of Chemistry and Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, 600 S. Mathews Ave., Urbana, IL 61801 (United States); Bohn, Paul W. [Department of Chemistry and Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, 600 S. Mathews Ave., Urbana, IL 61801 (United States)]. E-mail: bohn@scs.uiuc.edu

    2006-08-14

    Surface composition gradients of the signaling molecule, epidermal growth factor (EGF), have been prepared by an adaptation of the electrochemical gradient technique. EGF is covalently bound to the reactive component, 11-amino-l-undecanethiol (AUT), in a counterpropagating two-component gradient composed of AUT and poly(ethylene glycol) thiol (PEG) using carbodiimide coupling chemistry. Areas of the surface presenting -NH{sub 2} termination react with succinimidyl esters of solvent-accessible acidic amino acids in EGF, while non-specific protein adsorption is resisted in the PEG regions. The maximum surface coverage of EGF prepared in this manner was determined by surface plasmon resonance reflectometry (SPR) on spatially uniform films to be 20% < {gamma} {sub EGF} < 70% depending on the concentration of the EGF derivatization solution. EGF retains its biological activity with this immobilization process, as verified by culturing human umbilical vein endothelial cell (HUVEC) on an EGF-terminated surface for 24 h. PEG shows good resistance to EGF physical adsorption as demonstrated by both SPR and X-ray photoelectron spectroscopy (XPS). The N / C ratio of EGF gradients, which is characteristic of EGF adsorption, because only the protein contains N, while both protein and PEG contain C, was spatially mapped with XPS. The gradient composition distributions are sigmoidal with lateral distance, with the position of the gradient transition region being readily controlled by adjusting the applied potential window. EGF gradients with variable quantitative surface coverage profiles were generated by varying EGF and AUT concentrations.

  11. The critical role of EGF-β-catenin signaling in the epithelial-mesenchymal transition in human glioblastoma

    Directory of Open Access Journals (Sweden)

    Wang X

    2017-05-01

    Full Text Available Xingqiang Wang, Shanshi Wang, Xiaolong Li, Shigang Jin, Feng Xiong, Xin Wang Department of Neurosurgery, People’s Hospital of Rizhao, Jining Medical University, Rizhao, China Abstract: To date, β-catenin has been reported to be implicated in mediating the epithelial-mesenchymal transition (EMT in a variety of human cancers, which can be triggered by EGF. However, the mechanisms underlying EGF-β-catenin pathway-induced EMT of glioblastoma multiforme (GBM have not been reported previously. In the present study, immunohistochemistry, reverse transcription polymerase chain reaction, and Western blot were applied to investigate the effect of EGF-β-catenin pathway on EMT of GBM. Here, we identified that β-catenin mRNA and protein levels were up-regulated in GBM tissues and four kinds of glioblastoma cell lines, including T98G, A172, U87, and U251 cells, compared with normal brain tissue and astrocytes. In U87 cell line, inhibition of β-catenin by siRNA suppressed EGF-induced proliferation, migration, invasiveness, and the expression of EMT activators (Snail and Slug. In addition, the expression of epithelial markers (E-cadherin was up-regulated and the expression of mesenchymal markers (N-cadherin and MMP9 was down-regulated. Finally, inhibitor of PI3K/Akt signaling pathways inactivated the EGF-β-catenin-induced EMT. In conclusion, β-catenin-EMT pathway induced by EGF is important for GBM progression by the PI3K/Akt pathways. Inhibition of β-catenin leads to suppression of EGF pathway-induced EMT, which provides a new way to treat GBM patients. Keywords: EGF, β-catenin, EMT, GBM

  12. PRMT1-mediated methylation of the EGF receptor regulates signaling and cetuximab response

    KAUST Repository

    Liao, Hsin-Wei

    2015-11-16

    Posttranslational modifications to the intracellular domain of the EGFR are known to regulate EGFR functions; however, modifications to the extracellular domain and their effects remain relatively unexplored. Here, we determined that methylation at R198 and R200 of the EGFR extracellular domain by protein arginine methyltransferase 1 (PRMT1) enhances binding to EGF and subsequent receptor dimerization and signaling activation. In a mouse orthotopic colorectal cancer xenograft model, expression of a methylation-defective EGFR reduced tumor growth. Moreover, increased EGFR methylation sustained signaling activation and cell proliferation in the presence of the therapeutic EGFR monoclonal antibody cetuximab. In colorectal cancer patients, EGFR methylation level also correlated with a higher recurrence rate after cetuximab treatment and reduced overall survival. Together, these data indicate that R198/R200 methylation of the EGFR plays an important role in regulating EGFR functionality and resistance to cetuximab treatment.

  13. The you gene encodes an EGF-CUB protein essential for Hedgehog signaling in zebrafish.

    Directory of Open Access Journals (Sweden)

    Ian G Woods

    2005-03-01

    Full Text Available Hedgehog signaling is required for many aspects of development in vertebrates and invertebrates. Misregulation of the Hedgehog pathway causes developmental abnormalities and has been implicated in certain types of cancer. Large-scale genetic screens in zebrafish have identified a group of mutations, termed you-class mutations, that share common defects in somite shape and in most cases disrupt Hedgehog signaling. These mutant embryos exhibit U-shaped somites characteristic of defects in slow muscle development. In addition, Hedgehog pathway mutations disrupt spinal cord patterning. We report the positional cloning of you, one of the original you-class mutations, and show that it is required for Hedgehog signaling in the development of slow muscle and in the specification of ventral fates in the spinal cord. The you gene encodes a novel protein with conserved EGF and CUB domains and a secretory pathway signal sequence. Epistasis experiments support an extracellular role for You upstream of the Hedgehog response mechanism. Analysis of chimeras indicates that you mutant cells can appropriately respond to Hedgehog signaling in a wild-type environment. Additional chimera analysis indicates that wild-type you gene function is not required in axial Hedgehog-producing cells, suggesting that You is essential for transport or stability of Hedgehog signals in the extracellular environment. Our positional cloning and functional studies demonstrate that You is a novel extracellular component of the Hedgehog pathway in vertebrates.

  14. Systemic treatment with Epidermal Growth Factor (EGF)but not Insulin like Growth Factor (IGF-I) decrease the involution of the Prostate in Castrated Rats

    DEFF Research Database (Denmark)

    Tørring, Niels; Lars, Vinter-Jensen; Sørensen, Flemming Brandt;

    2000-01-01

    Epidermal growth factor (EGF) and insulin-like growth factor I (IGF-I) are strong inducers of proliferation to prostate cells cultured in serum-free medium. Accordingly we wanted to study the growth of the prostate gland in castrated rats after treatment with EGF, IGF-I and testosterone. Castrated...... Wistar rats were treated with growth factors (EGF 35 microg/rat per day; IGF-I 350 microg/rat per day) or testosterone (2 mg/rat per day) for 3 days either immediately after or 10 days after castration. Prostate tissue was examined by stereological and immunohistochemical techniques and by enzyme......-linked immunosorbent assay (ELISA). Treatment with EGF inhibited the involution of the prostate (P prostate involution as compared to castrated controls. EGF treatment significantly increased the endogenous rat EGF in the ventral prostate, but cellular...

  15. TERATOGENIC RESPONSES ARE MODULATED IN MICE LACKING EXPRESSION OF EPIDERMAL GROWTH FACTOR (EGF) AND TRANSFORMING GROWTH FACTOR-ALPHA (TGF)

    Science.gov (United States)

    TITLE:TERATOGENIC RESPONSES ARE MODULATED IN MICE LACKING EXPRESSION OF EPIDERMAL GROWTH FACTOR (EGF) AND TRANSFORMING GROWTH FACTOR-ALPHA (TGF). AUTHORS (ALL): Abbott, Barbara D.1; Best, Deborah S.1; Narotsky, Michael G.1. SPONSOR NAME: None INSTITUTIONS (ALL): 1. Repro Tox ...

  16. TERATOGENIC RESPONSES ARE MODULATED IN MICE LACKING EXPRESSION OF EPIDERMAL GROWTH FACTOR (EGF) AND TRANSFORMING GROWTH FACTOR-ALPHA (TGF)

    Science.gov (United States)

    TITLE:TERATOGENIC RESPONSES ARE MODULATED IN MICE LACKING EXPRESSION OF EPIDERMAL GROWTH FACTOR (EGF) AND TRANSFORMING GROWTH FACTOR-ALPHA (TGF). AUTHORS (ALL): Abbott, Barbara D.1; Best, Deborah S.1; Narotsky, Michael G.1. SPONSOR NAME: None INSTITUTIONS (ALL): 1. Repro Tox ...

  17. Superparamagnetic iron oxide nanoparticles conjugated with epidermal growth factor (SPION–EGF for targeting brain tumors

    Directory of Open Access Journals (Sweden)

    Shevtsov MA

    2014-01-01

    Full Text Available Maxim A Shevtsov,1,2 Boris P Nikolaev,3 Ludmila Y Yakovleva,3 Yaroslav Y Marchenko,3 Anatolii V Dobrodumov,4 Anastasiya L Mikhrina,5 Marina G Martynova,1 Olga A Bystrova,1 Igor V Yakovenko,2 Alexander M Ischenko31Institute of Cytology of the Russian Academy of Sciences (RAS, 2AL Polenov Russian Scientific Research Institute of Neurosurgery, 3Research Institute of Highly Pure Biopreparations, 4Institute of Macromolecular Compounds of the Russian Academy of Sciences (RAS, 5IM Sechenov Institute of Evolutionary Physiology and Biochemistry of the Russian Academy of Sciences (RAS, St Petersburg, RussiaAbstract: Superparamagnetic iron oxide nanoparticles (SPIONs conjugated with recombinant human epidermal growth factor (SPION–EGF were studied as a potential agent for magnetic resonance imaging contrast enhancement of malignant brain tumors. Synthesized conjugates were characterized by transmission electron microscopy, dynamic light scattering, and nuclear magnetic resonance relaxometry. The interaction of SPION–EGF conjugates with cells was analyzed in a C6 glioma cell culture. The distribution of the nanoparticles and their accumulation in tumors were assessed by magnetic resonance imaging in an orthotopic model of C6 gliomas. SPION–EGF nanosuspensions had the properties of a negative contrast agent with high coefficients of relaxation efficiency. In vitro studies of SPION–EGF nanoparticles showed high intracellular incorporation and the absence of a toxic influence on C6 cell viability and proliferation. Intravenous administration of SPION–EGF conjugates in animals provided receptor-mediated targeted delivery across the blood–brain barrier and tumor retention of the nanoparticles; this was more efficient than with unconjugated SPIONs. The accumulation of conjugates in the glioma was revealed as hypotensive zones on T2-weighted images with a twofold reduction in T2 relaxation time in comparison to unconjugated SPIONs (P<0.001. SPION–EGF

  18. Epidermal growth factor (EGF) sustains in vitro primordial follicle viability by enhancing stromal cell proliferation via MAPK and PI3K pathways in the prepubertal, but not adult, cat ovary.

    Science.gov (United States)

    Fujihara, Mayako; Comizzoli, Pierre; Keefer, Carol L; Wildt, David E; Songsasen, Nucharin

    2014-04-01

    This study examined the influences of epidermal growth factor (EGF) and growth differentiation factor 9 (GDF9) on in vitro viability and activation of primordial follicles in the ovarian tissue of prepubertal (age, 8 mo) cats. Ovarian cortical slices were cultured in medium containing EGF and/or GDF9 for 14 days. EGF, but not GDF9, improved (P primordial follicles regardless of age group. We then explored how EGF influenced primordial follicles in the prepubertal donors by coincubation with an inhibitor of EGF receptor (AG1478), mitogen-activated protein kinase (MAPK; U0126), or phosphoinositide 3-kinase (PI3K; LY294002). EGF enhanced (P primordial follicle viability (but without promoting activation) in the prepubertal cat. The mechanism of action is via stimulation of MAPK and PI3K signaling pathways that, in turn, promote ovarian cell proliferation. Particularly intriguing is that the ability of cat ovarian cells to multiply in reaction to EGF is age-dependent and highly responsive in prepubertal females.

  19. EGF receptor signalling is essential for electric-field-directed migration of breast cancer cells.

    Science.gov (United States)

    Pu, Jin; McCaig, Colin D; Cao, Lin; Zhao, Zhiqiang; Segall, Jeffrey E; Zhao, Min

    2007-10-01

    The mechanisms by which cancer cells migrate to metastasise are not fully understood. Breast cancers are accompanied by electrical depolarisation of tumour epithelial cells. The electrical changes can be detected on the skin and are used to differentiate malignant from benign breast tumours. Could the electrical signals play a role in metastasis by promoting tumour cell migration? We report that electric fields stimulate and direct migration of human breast cancer cells. Importantly, these effects were more significant in highly metastatic tumour cells than in low metastatic tumour cells. Electric-field-enhanced directional migration correlates well with the expression level of EGF receptor (EGFR/ErbB1). To confirm this, we transfected low metastatic clone MTC cells with human ErbB1, which significantly increased the electrotactic response. Inhibition of ErbB1 completely abolished the directional response of MTLn3 cells to an electric field. Transfection of MTLn3 cells and MDA-MB-435 cells with expression vectors for ErbB family members ErbB1, ErbB2 and ErbB3 also significantly enhanced EF-induced migration. These results suggest that electric signals might play a role in metastasis of breast cancers by enhancing cell migration through the ErbB-signalling pathway.

  20. Phosphoproteomics identified Endofin, DCBLD2, and KIAA0582 as novel tyrosine phosphorylation targets of EGF signaling and Iressa in human cancer cells

    DEFF Research Database (Denmark)

    Chen, Yunhao; Low, Teck-Yew; Choong, Lee-Yee;

    2007-01-01

    and relatively quantified the tyrosine phosphorylation levels of 21 proteins between control and EGF-treated A431 human cervical cancer cells. Of these, Endofin, DCBLD2, and KIAA0582 were validated to be novel tyrosine-phosphorylation targets of EGF signaling and Iressa, a highly selective inhibitor of EGFR...

  1. Interdependency of EGF and GLP-2 Signaling in Attenuating Mucosal Atrophy in a Mouse Model of Parenteral Nutrition

    DEFF Research Database (Denmark)

    Feng, Yongjia; Demehri, Farok R; Xiao, Weidong

    2017-01-01

    BACKGROUND & AIMS: Total parenteral nutrition (TPN), a crucial treatment for patients who cannot receive enteral nutrition, is associated with mucosal atrophy, barrier dysfunction, and infectious complications. Glucagon-like peptide-2 (GLP-2) and epidermal growth factor (EGF) improve intestinal...... deprived of enteral nutrition. METHODS: Adult C57BL/6J, IEC-Egfr(knock out (KO)) and IEC-pik3r1(KO) mice receiving TPN or enteral nutrition were treated with EGF or GLP-2 alone or in combination with reciprocal receptor inhibitors, GLP-2(3-33) or gefitinib. Jejunum was collected and mucosal atrophy and IEC...

  2. Binding of EGF1 Domain Peptide in Coagulation Factor Ⅶ with Tissue Factor and Its Implications for the Triggering of Coagulation

    Institute of Scientific and Technical Information of China (English)

    梅恒; 胡豫; 王华芳; 石威; 邓君; 郭涛

    2010-01-01

    The binding function of EGF1 domain peptide with tissue factor(TF)and its ability of triggering coagulation were explored.The TF expression model in vitro was established by lipopolysaccha-ride induction.The affinity of EGFP-EGF1 and TF expressing cells was analyzed by fluorescence microscopy and flow cytometry(FCM).The affinity of EGFP-EGF1 and rat soluble TF was quantitated by surface plasmon resonance(SPR).The ability of EGFP-EGF1 in triggering coagulation was tested by prothrombin time assay.The FCM res...

  3. Proteomic analysis of ovarian cancer cells during epithelial-mesenchymal transition (EMT) induced by epidermal growth factor (EGF) reveals mechanisms of cell cycle control.

    Science.gov (United States)

    Grassi, Mariana Lopes; Palma, Camila de Souza; Thomé, Carolina Hassibe; Lanfredi, Guilherme Pauperio; Poersch, Aline; Faça, Vitor Marcel

    2017-01-16

    Epithelial to mesenchymal transition (EMT) is a well-orchestrated process that culminates with loss of epithelial phenotype and gain of a mesenchymal and migratory phenotype. EMT enhances cancer cell invasiveness and drug resistance, favoring metastasis. Dysregulation of transcription factors, signaling pathways, miRNAs and growth factors including EGF, TGF-beta and HGF can trigger EMT. In ovarian cancer, overexpression of the EGFR family is associated with more aggressive clinical behavior. Here, the ovarian adenocarcinoma cell line Caov-3 was induced to EMT with EGF in order to identify specific mechanisms controlled by this process. Caov-3 cells induced to EMT were thoroughly validated and a combination of subcellular proteome enrichment, GEL-LC-MS/MS and SILAC strategy allowed consistent proteome identification and quantitation. Protein network analysis of differentially expressed proteins highlighted regulation of metabolism and cell cycle. Activation of relevant signaling pathways, such as PI3K/Akt/mTOR and Ras/Erk MAPK, in response to EGF-induced EMT was validated. Also, EMT did not affected the proliferation rate of Caov-3 cells, but led to cell cycle arrest in G1 phase regulated by increased levels of p21Waf1/Cip1, independently of p53. Furthermore, a decrease in G1 and G2 checkpoint proteins was observed, supporting the involvement of EGF-induced EMT in cell cycle control. Cancer is a complex multistep process characterized by accumulation of several hallmarks including epithelial to mesenchymal transition (EMT), which promotes cellular and microenvironmental changes resulting in invasion and migration to distant sites, favoring metastasis. EMT can be triggered by different extracellular stimuli, including growth factors such as EGF. In ovarian cancer, the most lethal gynecological cancer, overexpression of the EGFR family is associated with more aggressive clinical behavior, increasing mortality rate caused by metastasis. Our proteomic data, together

  4. Nanoconjugation prolongs endosomal signaling of the epidermal growth factor receptor and enhances apoptosis

    Science.gov (United States)

    Wu, L.; Xu, F.; Reinhard, B. M.

    2016-07-01

    It is becoming increasingly clear that intracellular signaling can be subject to strict spatial control. As the covalent attachment of a signaling ligand to a nanoparticle (NP) impacts ligand-receptor binding, uptake, and trafficking, nanoconjugation provides new opportunities for manipulating intracellular signaling in a controlled fashion. To establish the effect of nanoconjugation on epidermal growth factor (EGF) mediated signaling, we investigate here the intracellular fate of nanoconjugated EGF (NP-EGF) and its bound receptor (EGFR) by quantitative correlated darkfield/fluorescence microscopy and density-based endosomal fractionation. We demonstrate that nanoconjugation prolongs the dwell time of phosphorylated receptors in the early endosomes and that the retention of activated EGFR in the early endosomes is accompanied by an EGF mediated apoptosis at effective concentrations that do not induce apoptosis in the case of free EGF. Overall, these findings indicate nanoconjugation as a rational strategy for modifying signaling that acts by modulating the temporo-spatial distribution of the activated EGF-EGFR ligand-receptor complex.It is becoming increasingly clear that intracellular signaling can be subject to strict spatial control. As the covalent attachment of a signaling ligand to a nanoparticle (NP) impacts ligand-receptor binding, uptake, and trafficking, nanoconjugation provides new opportunities for manipulating intracellular signaling in a controlled fashion. To establish the effect of nanoconjugation on epidermal growth factor (EGF) mediated signaling, we investigate here the intracellular fate of nanoconjugated EGF (NP-EGF) and its bound receptor (EGFR) by quantitative correlated darkfield/fluorescence microscopy and density-based endosomal fractionation. We demonstrate that nanoconjugation prolongs the dwell time of phosphorylated receptors in the early endosomes and that the retention of activated EGFR in the early endosomes is accompanied by an EGF

  5. Gefitinib induces epidermal growth factor receptor dimers which alters the interaction characteristics with ¹²⁵I-EGF.

    Directory of Open Access Journals (Sweden)

    Hanna Björkelund

    Full Text Available The tyrosine kinase inhibitor gefitinib inhibits growth in some tumor types by targeting the epidermal growth factor receptor (EGFR. Previous studies show that the affinity of the EGF-EGFR interaction varies between hosting cell line, and that gefitinib increases the affinity for some cell lines. In this paper, we investigate possible mechanisms behind these observations. Real-time interaction analysis in LigandTracer® Grey revealed that the HER2 dimerization preventing antibody pertuzumab clearly modified the binding of ¹²⁵I-EGF to EGFR on HER2 overexpressing SKOV3 cells in the presence of gefitinib. Pertuzumab did not affect the binding on A431 cells, which express low levels of HER2. Cross-linking measurements showed that gefitinib increased the amount of EGFR dimers 3.0-3.8 times in A431 cells in the absence of EGF. In EGF stimulated SKOV3 cells the amount of EGFR dimers increased 1.8-2.2 times by gefitinib, but this effect was cancelled by pertuzumab. Gefitinib treatment did not alter the number of EGFR or HER2 expressed in tumor cell lines A431, U343, SKOV3 and SKBR3. Real-time binding traces were further analyzed in a novel tool, Interaction Map, which deciphered the different components of the measured interaction and supports EGF binding to multiple binding sites. EGFR and HER2 expression affect the levels of EGFR monomers, homodimers and heterodimers and EGF binds to the various monomeric/dimeric forms of EGFR with unique binding properties. Taken together, we conclude that dimerization explains the varying affinity of EGF-EGFR in different cells, and we propose that gefitinib induces EGFR dimmers, which alters the interaction characteristics with ¹²⁵I-EGF.

  6. Chicken granulosa cells show differential expression of epidermal growth factor (EGF) and luteinizing hormone (LH) receptor messenger RNA and differential responsiveness to EGF and LH dependent upon location of granulosa cells to the germinal disc.

    Science.gov (United States)

    Yao, H H; Bahr, J M

    2001-06-01

    Granulosa cells in the chicken follicle exhibit different phenotypes according to their location relative to the germinal disc (GD). Granulosa cells proximal to the GD (referred to as proximal granulosa cells) are more proliferative, whereas granulosa cells distal to the GD (referred to as distal granulosa cells) are more differentiated. We have shown that epidermal growth factor (EGF) derived from the GD stimulated proliferation of granulosa cells proximal to the GD, whereas extraovarian LH promoted differentiation. We tested the hypothesis that phenotypic differences of granulosa cells are the result of differential responsiveness of granulosa cells to EGF and LH. We found that both granulosa and theca layers of chicken preovulatory follicles expressed mRNA for EGF receptor (EGFr) by polymerase chain reaction (PCR) analysis. However, only the granulosa layer showed differential expression of EGFr and LH receptor (LHr) mRNA. Competitive reverse transcription-PCR revealed that proximal granulosa cells expressed more EGFr mRNA but less LHr mRNA than distal granulosa cells. In addition, proximal granulosa cells proliferated more in response to EGF than their distal counterparts. We further demonstrated that EGF decreased LHr mRNA expression by granulosa cells in a dose-dependent manner, whereas EGF and LH had no effect on EGFr mRNA expression except at one dose of LH (15 ng/ml) that stimulated EGFr mRNA expression. Our findings suggest that EGF derived from the GD influences the phenotypes of granulosa cells. Granulosa cells proximal to the GD exhibit a proliferative phenotype possibly because they are exposed to and are more responsive to GD-derived EGF. Furthermore, GD-derived EGF decreases LHr mRNA expression by proximal granulosa cells and therefore results in less differentiated granulosa cell phenotype. In contrast, granulosa cells distal to the GD are not under the influence of EGF and exhibit a more differentiated phenotype.

  7. Conditional loss of heparin-binding EGF-like growth factor results in enhanced liver fibrosis after bile duct ligation in mice

    Energy Technology Data Exchange (ETDEWEB)

    Takemura, Takayo; Yoshida, Yuichi [Department of Gastroenterology and Hepatology, Osaka University, Graduate School of Medicine, Osaka (Japan); Kiso, Shinichi, E-mail: kiso@gh.med.osaka-u.ac.jp [Department of Gastroenterology and Hepatology, Osaka University, Graduate School of Medicine, Osaka (Japan); Kizu, Takashi; Furuta, Kunimaro; Ezaki, Hisao; Hamano, Mina; Egawa, Mayumi; Chatani, Norihiro; Kamada, Yoshihiro [Department of Gastroenterology and Hepatology, Osaka University, Graduate School of Medicine, Osaka (Japan); Imai, Yasuharu [Department of Gastroenterology, Ikeda Municipal Hospital, Ikeda, Osaka (Japan); Higashiyama, Shigeki [Department of Biochemistry and Molecular Genetics, Ehime University, Graduate School of Medicine and Department of Cell Growth and Tumor Regulation, Proteo-Medicine Research Center (ProMRes), Ehime University, Shitsukawa, Toon, Ehime (Japan); Iwamoto, Ryo; Mekada, Eisuke [Department of Cell Biology, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka (Japan); Takehara, Tetsuo [Department of Gastroenterology and Hepatology, Osaka University, Graduate School of Medicine, Osaka (Japan)

    2013-07-26

    Highlights: •HB-EGF expression was increased during the development of liver fibrosis. •Conditional HB-EGF knockout mouse showed enhanced experimental liver fibrosis. •HB-EGF antagonized TGF-β-induced activation of hepatic stellate cells. •We report a possible protective role of HB-EGF in cholestatic liver fibrosis. -- Abstract: Our aims were to evaluate the involvement of heparin-binding EGF-like growth factor (HB-EGF) in liver fibrogenesis of humans and mice and to elucidate the effect of HB-EGF deficiency on cholestatic liver fibrosis using conditional HB-EGF knockout (KO) mice. We first demonstrated that gene expression of HB-EGF had a positive significant correlation with that of collagen in human fibrotic livers, and was increased in bile duct ligation (BDL)-induced fibrotic livers in mouse. We then generated conditional HB-EGF knockout (KO) mice using the interferon inducible Mx-1 promoter driven Cre recombinase transgene and wild type (WT) and KO mice were subjected to BDL. After BDL, KO mice exhibited enhanced liver fibrosis with increased expression of collagen, compared with WT mice. Finally, we used mouse hepatic stellate cells (HSCs) to examine the role of HB-EGF in the activation of these cells and showed that HB-EGF antagonized TGF-β-induced gene expression of collagen in mouse primary HSCs. Interestingly, HB-EGF did not prevent the TGF-β-induced nuclear accumulation of Smad3, but did lead to stabilization of the Smad transcriptional co-repressor TG-interacting factor. In conclusion, our data suggest a possible protective role of HB-EGF in cholestatic liver fibrosis.

  8. Reduced expression of the epidermal growth factor signaling system in preeclampsia.

    Science.gov (United States)

    Armant, D R; Fritz, R; Kilburn, B A; Kim, Y M; Nien, J K; Maihle, N J; Romero, R; Leach, R E

    2015-03-01

    The epidermal growth factor (EGF) signaling system regulates trophoblast differentiation, and its disruption could contribute to perinatal disease. We hypothesized that this pathway is altered in preeclampsia, a disorder associated with trophoblast apoptosis and failure to invade and remodel the uterine spiral arteries. Six EGF family peptides and a truncated EGF receptor splice variant (p110/EGFR) were examined using immunohistochemistry in the trophoblast of placentas (N = 76) from women with preeclampsia, and compared to placentas from women of similar gestational age (GA) with preterm labor (PTL) or small for gestational age (SGA) fetuses, as well as normal term placentas. EGF, transforming growth factor-α (TGFA), and heparin-binding EGF-like growth factor (HBEGF) were evaluated using ELISA in maternal plasma from another 20 pregnancies with or without preeclampsia. Cell death was evaluated in the HTR-8/SVneo human cytotrophoblast cell line using TUNEL to evaluate the protective effects of EGF peptides. Trophoblast HBEGF, TGFA, and EGF were significantly reduced in preeclampsia compared to PTL and SGA, while p110/EGFR accumulated significantly on the surface of the chorionic villi (p preeclampsia, whereas p110/EGFR, a potential EGF receptor antagonist, is overexpressed. These findings are consistent with the concept that disruption of the EGF signaling system contributes to aberrant trophoblast development associated with preeclampsia. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. Radiation-induced PGE2 sustains human glioma cells growth and survival through EGF signaling.

    Science.gov (United States)

    Brocard, Emeline; Oizel, Kristell; Lalier, Lisenn; Pecqueur, Claire; Paris, François; Vallette, François M; Oliver, Lisa

    2015-03-30

    Glioblastoma Multiforme (GBM) is the most common brain cancer in adults. Radiotherapy (RT) is the most effective post-operative treatment for the patients even though GBM is one of the most radio-resistant tumors. Dead or dying cells within the tumor are thought to promote resistance to treatment through mechanisms that are very poorly understood. We have evaluated the role of Prostaglandin E2 (PGE2), a versatile bioactive lipid, in GBM radio-resistance. We used an in vitro approach using 3D primary cultures derived from representative GBM patients. We show that irradiated glioma cells produced and released PGE2 in important quantities independently of the induction of cell death. We demonstrate that the addition of PGE2 enhances cell survival and proliferation though its ability to trans-activate the Epithelial Growth Factor receptor (EGFR) and to activate β-catenin. Indeed, PGE2 can substitute for EGF to promote primary cultures survival and growth in vitro and the effect is likely to occur though the Prostaglandin E2 receptor EP2.

  10. Radiation-induced PGE2 sustains human glioma cell growth and survival through EGF signaling

    Science.gov (United States)

    Lalier, Lisenn; Pecqueur, Claire; Paris, François; Vallette, François M.; Oliver, Lisa

    2015-01-01

    Glioblastoma Multiforme (GBM) is the most common brain cancer in adults. Radiotherapy (RT) is the most effective post-operative treatment for the patients even though GBM is one of the most radio-resistant tumors. Dead or dying cells within the tumor are thought to promote resistance to treatment through mechanisms that are very poorly understood. We have evaluated the role of Prostaglandin E2 (PGE2), a versatile bioactive lipid, in GBM radio-resistance. We used an in vitro approach using 3D primary cultures derived from representative GBM patients. We show that irradiated glioma cells produced and released PGE2 in important quantities independently of the induction of cell death. We demonstrate that the addition of PGE2 enhances cell survival and proliferation though its ability to trans-activate the Epithelial Growth Factor receptor (EGFR) and to activate β-catenin. Indeed, PGE2 can substitute for EGF to promote primary cultures survival and growth in vitro and the effect is likely to occur though the Prostaglandin E2 receptor EP2. PMID:25749386

  11. Epidermal growth factor promotes proliferation of dermal papilla cells via Notch signaling pathway.

    Science.gov (United States)

    Zhang, Haihua; Nan, Weixiao; Wang, Shiyong; Zhang, Tietao; Si, Huazhe; Wang, Datao; Yang, Fuhe; Li, Guangyu

    2016-08-01

    The effect of epidermal growth factor (EGF) on the development and growth of hair follicle is controversial. In the present study, 2-20 ng/ml EGF promoted the growth of mink hair follicles in vitro, whereas 200 ng/ml EGF inhibited follicle growth. Further, dermal papilla (DP) cells, a group of mesenchymal cells that govern hair follicle development and growth, were isolated and cultured in vitro. Treatment with or forced expression of EGF accelerated proliferation and induced G1/S transition in DP cells. Moreover, EGF upregulated the expression of DP mesenchymal genes, such as alkaline phosphatase (ALP) and insulin-like growth factor (IGF-1), as well as the Notch pathway molecules including Notch1, Jagged1, Hes1 and Hes5. In addition, inhibition of Notch signaling pathway by DAPT significantly reduced the basal and EGF-enhanced proliferation rate, and also suppressed cell cycle progression. We also show that the expression of several follicle-regulatory genes, such as Survivin and Msx2, were upregulated by EGF, and was inhibited by DAPT. In summary, our study demonstrates that the concentration of EGF is critical for the switch between hair follicle growth and inhibition, and EGF promotes DP cell proliferation via Notch signaling pathway.

  12. Epidermal growth factor (EGF) in the gastroprotective and ulcer healing actions of colloidal bismuth subcitrate (De-Nol) in rats.

    Science.gov (United States)

    Konturek, S J; Dembinski, A; Warzecha, Z; Bielanski, W; Brzozowski, T; Drozdowicz, D

    1988-01-01

    Colloidal bismuth subcitrate (CBS; De-Nol) exhibits gastroprotective properties in experimental animals and enhances the healing of chronic gastroduodenal ulcers, but the mechanisms of these actions have not been entirely elucidated. The present study was designed to determine whether epidermal growth factor (EGF), which also has gastroprotective and ulcer healing properties, contributes to the action of De-Nol on the stomach in rats. It was found that De-Nol protects the gastric mucosa against ethanol damage and that this is accompanied by increased mucosal generation of prostaglandins (PG). Removal of the endogenous source of EGF (sialoadenectomy) did not significantly decrease the protective and PG stimulating effects of De-Nol. Pretreatment with exogenous EGF partially protected the stomach against ethanol injury, but did not influence the protective action of De-Nol in sialoadenectomised animals. De-Nol, like EGF given orally, enhanced the healing of chronic gastric and duodenal ulcers induced by serosal acetic acid. De-Nol was found to bind EGF in a pH-dependent manner and to accumulate it in ulcer area. Thus the peptide is available locally in high concentrations to accelerate the re-epithelialisation and tissue repair of the ulcerated mucosa. These ulcer healing effects of De-Nol were reduced by sialoadenectomy and restored in part by oral administration of EGF. We conclude that salivary glands in rats are not essential for the gastroprotection induced by De-Nol, but seem to play an important role in the ulcer healing action of this drug possibly via an EGF mediated mechanism. PMID:3260885

  13. Quantitative analysis of HGF and EGF-dependent phosphotyrosine signaling networks

    DEFF Research Database (Denmark)

    Hammond, Dean E; Hyde, Russell; Kratchmarova, Irina;

    2010-01-01

    549 lung adenocarcinoma cells with EGF or HGF. In total, we obtained quantitative information for 274 proteins, which respond to either or both stimuli by >1.5 fold changes in enrichment, following immuno-precipitation with antiphosphotyrosine antibodies. The data reveal a high degree of overlap...

  14. The homeobox gene mirror links EGF signalling to embryonic dorso-ventral axis formation through notch activation.

    Science.gov (United States)

    Jordan, K C; Clegg, N J; Blasi, J A; Morimoto, A M; Sen, J; Stein, D; McNeill, H; Deng, W M; Tworoger, M; Ruohola-Baker, H

    2000-04-01

    Recent studies in vertebrates and Drosophila melanogaster have revealed that Fringe-mediated activation of the Notch pathway has a role in patterning cell layers during organogenesis. In these processes, a homeobox-containing transcription factor is responsible for spatially regulating fringe (fng) expression and thus directing activation of the Notch pathway along the fng expression border. Here we show that this may be a general mechanism for patterning epithelial cell layers. At three stages in Drosophila oogenesis, mirror (mirr) and fng have complementary expression patterns in the follicle-cell epithelial layer, and at all three stages loss of mirr enlarges, and ectopic expression of mirr restricts, fng expression, with consequences for follicle-cell patterning. These morphological changes are similar to those caused by Notch mutations. Ectopic expression of mirr in the posterior follicle cells induces a stripe of rhomboid (rho) expression and represses pipe (pip), a gene with a role in the establishment of the dorsal-ventral axis, at a distance. Ectopic Notch activation has a similar long-range effect on pip. Our results suggest that Mirror and Notch induce secretion of diffusible morphogens and we have identified TGF-beta (encoded by dpp) as such a molecule in germarium. We also found that mirr expression in dorsal follicle cells is induced by the EGF-receptor (EGFR) pathway and that mirr then represses pip expression in all but the ventral follicle cells, connecting EGFR activation in the dorsal follicle cells to repression of pip in the dorsal and lateral follicle cells. Our results suggest that the differentiation of ventral follicle cells is not a direct consequence of germline signalling, but depends on long-range signals from dorsal follicle cells, and provide a link between early and late events in Drosophila embryonic dorsal-ventral axis formation.

  15. Stimulation of chondrocytes in vitro by gene transfer with plasmids coding for epidermal growth factor (hEGF) and basic fibroblast growth factor (bFGF)

    DEFF Research Database (Denmark)

    Schmal, H; Mehlhorn, A T; Zwingmann, J

    2005-01-01

    Human epidermal growth factor (hEGF) and basic fibroblast growth factor (bFGF) influence critical characteristics of chondrocytes. The effects on metabolism and differentiation were evaluated following transfection using specific plasmids coding for both cytokines. Chondrocytes were isolated from...... of recombinant hEGF and bFGF resulted in a significant increase in cell proliferation and glucosaminoglycan production. Chondrocytes were transfected with vectors coding for either hEGF or bFGF and the production of these proteins was measured in supernatants by ELISA. Expression kinetics showed different...... patterns: hEGF was detectable 2.5 days following transfection and peaked at day 5.5, whereas bFGF-production reached its maximum 1.5 days after transfection, declining thereafter. Chondrocytes endogenously produced significant amounts of bFGF within 5 days following isolation. Proliferation of h...

  16. ErbB1-4-dependent EGF/neuregulin signals and their cross talk in the central nervous system: pathological implications in schizophrenia and Parkinson’s disease

    Directory of Open Access Journals (Sweden)

    Yuriko eIwakura

    2013-02-01

    Full Text Available Ligands for ErbB1-4 receptor tyrosine kinases, such as epidermal growth factor (EGF and neuregulins, regulate brain development and function. Thus, abnormalities in their signaling are implicated in the etiology or pathology of schizophrenia and Parkinson’s disease. Among the ErbB receptors, ErbB1 and ErbB4 are expressed in dopamine and GABA neurons, while ErbB1, 2, and/or 3 are mainly present in oligodendrocytes, astrocytes and their precursors. Thus, deficits in ErbB signaling might contribute to schizophrenia neuropathology stemming from these cell types. By incorporating the latest cancer molecular biology as well as our recent progress, we discuss signal cross talk between the ErbB1-4 subunits and their neurobiological functions in each cell type. The potential contribution of virus-derived cytokines (virokines that mimic EGF and neuregulin-1 in brain diseases are also discussed.

  17. The interaction between epidermal growth factor (EGF) and matrix metalloproteinase induces the development of sweat glands in human fetal skin

    Institute of Scientific and Technical Information of China (English)

    Li Jianfu; Fu Xiaobing; Sheng Zhiyong

    2001-01-01

    Objective:The development of sweat glands is a very complicated biological process involving many factors. In this study, we explore the inter-relationship between epidermal growth factor (EGF),matrix metalloproteinases (MMP-2,MMP-7) and development of sweat glands in human embryos. Furthermore, we hope to elucidate the mechanism(s) underlying the induction of epidermal stem cells into sweat gland cells. Methods:Skin biospies of human embryos obtained from spontaneous abortions at different gestational ages from 11 to 31 weeks were used in this study. The dynamical expression of EGF, MMP-2, MMP-7 and keratin-7 (K7) in developing sweat gland cells or extracellular stroma surrounding the sweat gland cells were examined with S-P immunohistochemical methods.The localization of the cellular sources of MMP-2 and MMP 7 was examined with in situ hybridization. Results:At 14-20 wk of gestation, a gradual increase in EGF immunoreactivity was observed not only in developing sweat gland buds but also in extracellular stroma surrounding the buds,and the expression intensity peaked at 20-22 wk of gesta- tional age. All mRNA-positive buds or cells in developing sweat glands contained corresponding immunoreactive proteins. Positive immunostaining for K7 appeared in early sweat gland buds at 14-16wk of gestation, and from then on, K7 was concentrated in developing sweat gland cords or cells. Conclusions: The morphogenesis of sweat gland in human fetal skin begins at 14-16wk of gestational age, and essentially completes by 24wk. There is a close relationship among EGF,extracellular matrix remodeling and morphogenesis of sweat glands, and EGF is one of the inducers in the development and maturity of sweat gland buds or cells.

  18. Grape seed extract inhibits EGF-induced and constitutively active mitogenic signaling but activates JNK in human prostate carcinoma DU145 cells: possible role in antiproliferation and apoptosis.

    Science.gov (United States)

    Tyagi, Alpana; Agarwal, Rajesh; Agarwal, Chapla

    2003-03-06

    A loss of functional androgen receptor and an enhanced expression of growth factor receptors and associated ligands are causal genetic events in prostate cancer (PCA) progression. These genetic alterations lead to an epigenetic mechanism where a feedback autocrine loop between membrane receptor and ligand (e.g. EGFR-TGFalpha) results in a constitutive activation of MAPK-Elk1-AP1-mediated mitogenic signaling in human PCA at an advanced and androgen-independent stage. We rationalized that inhibiting these epigenetic events could be useful in controlling advanced PCA growth. Recently, we found that grape seed extract (GSE), a dietary supplement rich in flavonoid procyanidins, inhibits advanced and androgen-independent human PCA DU145 cell growth in culture and nude mice. Here, we performed detailed mechanistic studies to define the effect of GSE on EGFR-Shc-MAPK-Elk1-AP1-mediated mitogenic signaling in DU145 cells. Pretreatment of serum-starved cells with GSE resulted in 70% to almost complete inhibition of EGF-induced EGFR activation and 50% to complete inhibition of Shc activation, which corroborated with a comparable decrease in EGF-induced Shc binding to EGFR. Conversely, EGF-induced ERK1/2 phosphorylation was inhibited only by lower doses of GSE; in fact, higher doses showed an increase. Additional studies showed that GSE alone causes a dose- and time-dependent increase in ERK1/2 phosphorylation in starved DU145 cells that is inhibited by an MEK1 inhibitor PD98059. Independent of this increase in ERK1/2 phosphorylation, GSE showed a strong inhibition of ERK1/2 kinase activity to Elk1 in both cellular and cell-free systems. GSE treatment of cells also inhibited both EGF-induced and constitutively active Elk1 phosphorylation and AP1 activation. GSE treatment also showed DNA synthesis inhibition in starved and EGF-stimulated cells as well as loss of cell viability and apoptotic death that was further increased by adding MEK1 inhibitor. Since GSE strongly induced

  19. Minimally invasive colorectal resection is associated with a rapid and sustained decrease in plasma levels of epidermal growth factor (EGF) in the colon cancer setting.

    Science.gov (United States)

    Grieco, Michael J; Shantha Kumara, H M C; Baxter, Raymond; Dujovny, Nadav; Kalady, Matthew F; Cekic, Vesna; Luchtefeld, Martin; Whelan, Richard L

    2010-10-01

    Epidermal growth factor (EGF) stimulates tumor growth directly via tumor cell EGF receptors or indirectly via its proangiogenic effects. This study's purpose was to determine the impact of minimally invasive colorectal resection (MICR) on postoperative (postop) plasma EGF levels in the colorectal cancer (CRC) and benign disease settings and to see if preoperative (PreOp) EGF levels are altered in cancer patients. MICR patients with benign pathology (n = 40) and CRC (n = 48) had blood samples taken PreOp and on postoperative days (POD) 1 and 3. In some patients, late samples were taken between POD7 and POD60; these were bundled into 7-day blocks and considered as single time points. EGF levels were determined by enzyme-linked immunosorbent assay (ELISA) and results were reported as mean ± SD after logarithmic transformation. The Student t test was used (p MICR is associated with a significant decrease in EGF levels early postop in both cancer and benign settings. Unlike the benign group, EGF blood levels in cancer patients remain low during the second postop month. A larger study with more late samples is needed to verify these results. EGF may have value as a tumor marker.

  20. A sensitive enzyme immunoassay for human epidermal growth factor. Determination of hEGF in human serum and urine and pharmacokinetics in mouse.

    Science.gov (United States)

    Hayashi, T; Hashimoto, K; Sakamoto, S

    1989-07-01

    A sensitive enzyme immunoassay for human epidermal growth factor (hEGF) is described. The anti-hEGF antibody was prepared by immunizing rabbits with hEGF, which was synthesized by Escherichia coli using the genetic engineering technique. The present assay system was based on the sandwiching of an antigen between anti-hEGF F(ab')2 precoated on a 96-well polystyrene plate and beta-D-galactosidase-labeled anti-hEGF Fab'. The range of measurable hEGF by this assay was 0.1-100 pg/well. Recoveries of hEGF added to serum and urine ranged between 94 and 108%. The intra- and inter-assay coefficients of variation were less than 6 and 8%, respectively. The results obtained by this assay method correlated well with those obtained by the radioimmunoassay method. By using this assay, the time course of serum hEGF levels in mice after the various administrations were also examined.

  1. Vascular endothelial (VEGF) and epithelial growth factor (EGF) as well as platelet-activating factor (PAF) and receptors are expressed in the early pregnant canine uterus.

    Science.gov (United States)

    Schäfer-Somi, S; Sabitzer, S; Klein, D; Reinbacher, E; Kanca, H; Beceriklisoy, H B; Aksoy, O A; Kucukaslan, I; Macun, H C; Aslan, S

    2013-02-01

    The aim of this study was to investigate the course of expression of platelet-activating factor (PAF), PAF-receptor (PAF-R), epidermal growth factor (EGF), EGF-R, vascular endothelial growth factor (VEGF), VEGF-R1 and VEGF-R2 in uterine tissue during canine pregnancy. For this purpose, 20 bitches were ovariohysterectomized at days 10-12 (n = 10), 18-25 (n = 5) and 28-45 (n = 5) days after mating, respectively. The pre-implantation group was proven pregnant by embryo flushing of the uterus after the operation, the others by sonography. Five embryo negative, that is, non-pregnant, bitches in diestrus (day 10-12) served as controls. Tissue samples from the uterus (placentation sites and horn width, respectively) were excised and snap-frozen in liquid nitrogen after embedding in Tissue Tec(®). Extraction of mRNA for RT-PCR was performed with Tri-Reagent. In the embryos, mRNA from all factors except VEGF was detected. In the course of pregnancy, significantly higher expression of PAF and PAFR as well as VEGF and VEGFR2 during the pre-implantation stage than in all other stages and a strong upregulation of EGF during implantation were characteristic. The course of EGF was in diametrical opposition to the course of the receptor. These results point towards an increased demand for VEGF, EGF and PAF during the earliest stages of canine pregnancy.

  2. An in vivo EGF receptor localization screen in C. elegans Identifies the Ezrin homolog ERM-1 as a temporal regulator of signaling.

    Science.gov (United States)

    Haag, Andrea; Gutierrez, Peter; Bühler, Alessandra; Walser, Michael; Yang, Qiutan; Langouët, Maeva; Kradolfer, David; Fröhli, Erika; Herrmann, Christina J; Hajnal, Alex; Escobar-Restrepo, Juan M

    2014-05-01

    The subcellular localization of the epidermal growth factor receptor (EGFR) in polarized epithelial cells profoundly affects the activity of the intracellular signaling pathways activated after EGF ligand binding. Therefore, changes in EGFR localization and signaling are implicated in various human diseases, including different types of cancer. We have performed the first in vivo EGFR localization screen in an animal model by observing the expression of the EGFR ortholog LET-23 in the vulval epithelium of live C. elegans larvae. After systematically testing all genes known to produce an aberrant vulval phenotype, we have identified 81 genes regulating various aspects of EGFR localization and expression. In particular, we have found that ERM-1, the sole C. elegans Ezrin/Radixin/Moesin homolog, regulates EGFR localization and signaling in the vulval cells. ERM-1 interacts with the EGFR at the basolateral plasma membrane in a complex distinct from the previously identified LIN-2/LIN-7/LIN-10 receptor localization complex. We propose that ERM-1 binds to and sequesters basolateral LET-23 EGFR in an actin-rich inactive membrane compartment to restrict receptor mobility and signaling. In this manner, ERM-1 prevents the immediate activation of the entire pool of LET-23 EGFR and permits the generation of a long-lasting inductive signal. The regulation of receptor localization thus serves to fine-tune the temporal activation of intracellular signaling pathways.

  3. EFFECTS OF EPIDERMAL GROWTH FACTOR (EGF), TRANSFORMING GROWTH FACTOR- (TGF), AND 2,3,7,8-TETRACHLORODIBENZO-P-DIOXIN ON FUSION OF EMBRYONIC PALATES IN SERUM-FREE ORGAN CULTURE USING WILD-TYPE, EGF KNOCKOUT, AND TGF KNOCKOUT MOUSE STRAINS

    Science.gov (United States)

    Backround: 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is teratogenic in mice, producing cleft palate (CP). TCDD exposure disrupts expression of epidermal growth factor (EGF) receptor, EGF, and transforming growth factor- (TGF) in the palate and affects proliferation and different...

  4. Milk fat globule-EGF factor 8 mediates the enhancement of apoptotic cell clearance by glucocorticoids.

    Science.gov (United States)

    Lauber, K; Keppeler, H; Munoz, L E; Koppe, U; Schröder, K; Yamaguchi, H; Krönke, G; Uderhardt, S; Wesselborg, S; Belka, C; Nagata, S; Herrmann, M

    2013-09-01

    The phagocytic clearance of apoptotic cells is essential to prevent chronic inflammation and autoimmunity. The phosphatidylserine-binding protein milk fat globule-EGF factor 8 (MFG-E8) is a major opsonin for apoptotic cells, and MFG-E8(-/-) mice spontaneously develop a lupus-like disease. Similar to human systemic lupus erythematosus (SLE), the murine disease is associated with an impaired clearance of apoptotic cells. SLE is routinely treated with glucocorticoids (GCs), whose anti-inflammatory effects are consentaneously attributed to the transrepression of pro-inflammatory cytokines. Here, we show that the GC-mediated transactivation of MFG-E8 expression and the concomitantly enhanced elimination of apoptotic cells constitute a novel aspect in this context. Patients with chronic inflammation receiving high-dose prednisone therapy displayed substantially increased MFG-E8 mRNA levels in circulating monocytes. MFG-E8 induction was dependent on the GC receptor and several GC response elements within the MFG-E8 promoter. Most intriguingly, the inhibition of MFG-E8 induction by RNA interference or genetic knockout strongly reduced or completely abolished the phagocytosis-enhancing effect of GCs in vitro and in vivo. Thus, MFG-E8-dependent promotion of apoptotic cell clearance is a novel anti-inflammatory facet of GC treatment and renders MFG-E8 a prospective target for future therapeutic interventions in SLE.

  5. Epidermal growth factor (EGF and interleukin (IL-1β synergistically promote ERK1/2-mediated invasive breast ductal cancer cell migration and invasion

    Directory of Open Access Journals (Sweden)

    Ma Liqiang

    2012-10-01

    Full Text Available Abstract Background Patients with invasive breast ductal carcinoma (IBDC with metastasis have a very poor prognosis. Little is known about the synergistic action of growth and inflammatory factors in IBDC metastases. Methods The expression of activated extracellular signal-regulated kinase1/2 (phosphorylated or p-ERK1/2 was analyzed by immunohistochemistry in IBDC tissue samples from 80 cases. BT474 IBDC cell migration and invasion were quantified using the Transwell assay. Matrix metalloproteinase (MMP-9 expression and activity were analyzed by RT-PCR, Western blotting and zymography. Activator protein (AP-1 activity was measured with a luciferase reporter gene assay. The Wilcoxon signed-rank test, Chi-square test, the partition of Chi-square test, independent t-test, and Spearman’s method were used for the statistical analysis. Results Phosphorylated ERK1/2 was detected in 58/80 (72.5% IBDC tissues, and was associated with higher TNM stage and lymph node metastasis, but not patient age or tumor size. Individually, epidermal growth factor (EGF, and interleukin (IL-1β activated ERK1/2, increased cell migration and invasion, MMP-9 expression and activity, AP-1 activation in vitro and the expression of p-ERK1/2 was positively correlated with EGF expression levels, as well as IL-1β, MMP-9 and c-fos in IBDC tissue samples. Co-stimulation with EGF and IL-1β synergistically increased ERK1/2 and AP-1 activation, cell migration and invasion, and MMP-9 expression and activity. Inhibition of ERK1/2 using U0126 or siRNA abolished EGF and/or IL-1β-induced cell migration and invasion in a dose-dependent manner. Conclusion Activated ERK1/2 was associated with higher TNM stage and lymph node metastasis in IBDC. Both in vitro and in vivo studies indicated that ERK-1/2 activation may increase the metastatic ability of IBDC cells. Growth and inflammatory factors synergistically induced IBDC cell migration and invasion via ERK1/2 signaling, AP-1 activation

  6. HEPARIN-BINDING EGF CLEAVAGE MEDIATES ZINC-INDUCED EGF RECEPTOR PHOSPHORYLATION

    Science.gov (United States)

    We have previously shown that exposure to zinc ions can activate epidermal growth factor (EGF) receptor (EGFR) signaling in murine fibroblasts and A431 cells through a mechanism involving Src kinase. While studying the effects of zinc ions in normal human bronchial epithelial cel...

  7. Plasma EGF and cognitive decline in Parkinson's disease and Alzheimer's disease.

    Science.gov (United States)

    Lim, Nicholas S; Swanson, Christine R; Cherng, Hua-Ren; Unger, Travis L; Xie, Sharon X; Weintraub, Daniel; Marek, Ken; Stern, Matthew B; Siderowf, Andrew; Trojanowski, John Q; Chen-Plotkin, Alice S

    2016-05-01

    Cognitive decline occurs in multiple neurodegenerative diseases, including Alzheimer's disease (AD) and Parkinson's disease (PD). Shared underlying mechanisms may exist and manifest as shared biomarker signatures. Previously, we nominated plasma epidermal growth factor (EGF) as a biomarker predicting cognitive decline in patients with established PD. Here, we investigate EGF as a predictive biomarker in prodromal PD, as well as AD. A cohort of PD patients (n = 236) was recruited to replicate our finding that low baseline EGF levels predict future cognitive decline. Additionally, plasma EGF and cognitive outcome measures were obtained from individuals with normal cognition (NC, n = 58), amnestic mild cognitive impairment (AD-MCI, n = 396), and Alzheimer's disease (AD, n = 112) in the Alzheimer's Disease Neuroimaging Initiative (ADNI) cohort to investigate whether low EGF levels correlate with cognitive status and outcome in AD-MCI and AD. Third, plasma EGF and cognitive measures were evaluated in the high-risk asymptomatic Parkinson's Associated Risk Study (PARS) cohort (n = 165) to investigate the association of EGF and cognitive performance in a PD prodromal context. In both PD and AD-MCI, low baseline plasma EGF predicted poorer long-term cognitive outcomes. In asymptomatic individuals at highest risk for developing PD from the PARS cohort, low baseline plasma EGF associated with poorer performance in the visuospatial domain but not in other cognitive domains. Low plasma EGF at baseline predicts cognitive decline in both AD and PD. Evidence for this signal may exist in prodromal stages of both diseases.

  8. Genetic interaction implicates iRhom2 in the regulation of EGF receptor signalling in mice

    Directory of Open Access Journals (Sweden)

    Owen M. Siggs

    2014-11-01

    Full Text Available iRhoms are closely related to rhomboid intramembrane proteases but lack catalytic activity. In mammals iRhoms are known to regulate the trafficking of TACE, the protease that cleaves the membrane bound inflammatory cytokine TNF. We have mapped a spontaneously occurring mouse mutation with a loss of hair phenotype, curly bare (cub, to the Rhbdf2 locus, which encodes the iRhom2 protein. The cub deletion removes the first 268 amino acids of the iRhom2 protein but is not a loss of function. We have also identified a previously reported suppressor of cub, called Mcub (modifier of curly bare, and find it to be a loss of function allele of the amphiregulin gene (Areg. Amphiregulin is an activating ligand of the epidermal growth factor receptor (EGFR that, like TNF, is released by TACE. Our results therefore imply a regulatory link between iRhoms and EGFR signalling in mammals. We have tested the model that the cub mutation leads to iRhom2 hyperactivity and consequently excess TACE processing of amphiregulin and elevated EGFR signalling. Our results do not support this hypothesis: we find that, compared to wild-type cells, cub mutant embryonic fibroblasts release less amphiregulin, and that the cub mutant form of iRhom2 is less able than wild type to bind to TACE and promote its maturation.

  9. A proteomics strategy to elucidate functional protein-protein interactions applied to EGF signaling

    DEFF Research Database (Denmark)

    Blagoev, B.; Kratchmarova, I.; Ong, S.E.

    2003-01-01

    Mass spectrometry-based proteomics can reveal protein-protein interactions on a large scale, but it has been difficult to separate background binding from functionally important interactions and still preserve weak binders. To investigate the epidermal growth factor receptor (EGFR) pathway, we...... and Src homologous and collagen (Shc) protein. We identified 228 proteins, of which 28 were selectively enriched upon stimulation. EGFR and Shc, which interact directly with the bait, had large differential ratios. Many signaling molecules specifically formed complexes with the activated EGFR-Shc, as did...... plectin, epiplakin, cytokeratin networks, histone H3, the glycosylphosphatidylinositol (GPI)-anchored molecule CD59, and two novel proteins. SILAC combined with modification-based affinity purification is a useful approach to detect specific and functional protein-protein interactions....

  10. Influence of epidermal growth factor (EGF) and hydrocortisone on the co-culture of mature adipocytes and endothelial cells for vascularized adipose tissue engineering.

    Science.gov (United States)

    Huber, Birgit; Czaja, Alina Maria; Kluger, Petra Juliane

    2016-05-01

    The composition of vascularized adipose tissue is still an ongoing challenge as no culture medium is available to supply adipocytes and endothelial cells appropriately. Endothelial cell medium is typically supplemented with epidermal growth factor (EGF) as well as hydrocortisone (HC). The effect of EGF on adipocytes is discussed controversially. Some studies say it inhibits adipocyte differentiation while others reported of improved adipocyte lipogenesis. HC is known to have lipolytic activities, which might result in mature adipocyte dedifferentiation. In this study, we evaluated the influence of EGF and HC on the co-culture of endothelial cells and mature adipocytes regarding their cell morphology and functionality. We showed in mono-culture that high levels of HC promoted dedifferentiation and proliferation of mature adipocytes, whereas EGF seemed to have no negative influence. Endothelial cells kept their typical cobblestone morphology and showed a proliferation rate comparable to the control independent of EGF and HC concentration. In co-culture, HC promoted dedifferentiation of mature adipocytes, which was shown by a higher glycerol release. EGF had no negative impact on adipocyte morphology. No negative impact on endothelial cell morphology and functionality could be seen with reduced EGF and HC supplementation in co-culture with mature adipocytes. Taken together, our results demonstrate that reduced levels of HC are needed for co-culturing mature adipocytes and endothelial cells. In co-culture, EGF had no influence on mature adipocytes. Therefore, for the composition of vascularized adipose tissue constructs, the media with low levels of HC and high or low levels of EGF can be used.

  11. Monitoring the cytoskeletal EGF response in live gastric carcinoma cells.

    Directory of Open Access Journals (Sweden)

    Marco Felkl

    Full Text Available Altered cell motility is considered to be a key factor in determining tumor invasion and metastasis. Epidermal growth factor (EGF signaling has been implicated in this process by affecting cytoskeletal organization and dynamics in multiple ways. To sort the temporal and spatial regulation of EGF-dependent cytoskeletal re-organization in relation to a cell's motile behavior time-lapse microscopy was performed on EGF-responsive gastric carcinoma-derived MKN1 cells co-expressing different fluorescently labeled cytoskeletal filaments and focal adhesion components in various combinations. The experiments showed that EGF almost instantaneously induces a considerable increase in membrane ruffling and lamellipodial activity that can be inhibited by Cetuximab EGF receptor antibodies and is not elicited in non-responsive gastric carcinoma Hs746T cells. The transient cell extensions are rich in actin but lack microtubules and keratin intermediate filaments. We show that this EGF-induced increase in membrane motility can be measured by a simple image processing routine. Microtubule plus-ends subsequently invade growing cell extensions, which start to accumulate focal complexes at the lamellipodium-lamellum junction. Such paxillin-positive complexes mature into focal adhesions by tyrosine phosphorylation and recruitment of zyxin. These adhesions then serve as nucleation sites for keratin filaments which are used to enlarge the neighboring peripheral keratin network. Focal adhesions are either disassembled or give rise to stable zyxin-rich fibrillar adhesions which disassemble in the presence of EGF to support formation of new focal adhesion sites in the cell periphery. Taken together the results serve as a basis for modeling the early cytoskeletal EGF response as a tightly coordinated and step-wise process which is relevant for the prediction of the effectiveness of anti-EGF receptor-based tumor therapy.

  12. EGF-mediated EGFR/ERK signaling pathway promotes germinative cell proliferation in Echinococcus multilocularis that contributes to larval growth and development.

    Science.gov (United States)

    Cheng, Zhe; Liu, Fan; Li, Xiu; Dai, Mengya; Wu, Jianjian; Guo, Xinrui; Tian, Huimin; Heng, Zhijie; Lu, Ying; Chai, Xiaoli; Wang, Yanhai

    2017-02-01

    Larvae of the tapeworm E. multilocularis cause alveolar echinococcosis (AE), one of the most lethal helminthic infections in humans. A population of stem cell-like cells, the germinative cells, is considered to drive the larval growth and development within the host. The molecular mechanisms controlling the behavior of germinative cells are largely unknown. Using in vitro cultivation systems we show here that the EGFR/ERK signaling in the parasite can promote germinative cell proliferation in response to addition of human EGF, resulting in stimulated growth and development of the metacestode larvae. Inhibition of the signaling by either the EGFR inhibitors CI-1033 and BIBW2992 or the MEK/ERK inhibitor U0126 impairs germinative cell proliferation and larval growth. These data demonstrate the contribution of EGF-mediated EGFR/ERK signaling to the regulation of germinative cells in E. multilocularis, and suggest the EGFR/ERK signaling as a potential therapeutic target for AE and perhaps other human cestodiasis.

  13. Ectodomain cleavage of the EGF ligands HB-EGF, neuregulin1-beta, and TGF-alpha is specifically triggered by different stimuli and involves different PKC isoenzymes.

    Science.gov (United States)

    Herrlich, Andreas; Klinman, Eva; Fu, Jonathan; Sadegh, Cameron; Lodish, Harvey

    2008-12-01

    Metalloproteinase cleavage of transmembrane proteins (ectodomain cleavage), including the epidermal growth factor (EGF) ligands heparin-binding EGF-like growth factor (HB-EGF), neuregulin (NRG), and transforming growth factor-alpha (TGF-alpha), is important in many cellular signaling pathways and is disregulated in many diseases. It is largely unknown how physiological stimuli of ectodomain cleavage--hypertonic stress, phorbol ester, or activation of G-protein-coupled receptors [e.g., by lysophosphatidic acid (LPA)]--are molecularly connected to metalloproteinase activation. To study this question, we developed a fluorescence-activated cell sorting (FACS)- based assay that measures cleavage of EGF ligands in single living cells. EGF ligands expressed in mouse lung epithelial cells are differentially and specifically cleaved depending on the stimulus. Inhibition of protein kinase C (PKC) isoenzymes or metalloproteinase inhibition by batimastat (BB94) showed that different regulatory signals are used by different stimuli and EGF substrates, suggesting differential effects that act on the substrate, the metalloproteinase, or both. For example, hypertonic stress led to strong cleavage of HB-EGF and NRG but only moderate cleavage of TGF-alpha. HB-EGF, NRG, and TGF-alpha cleavage was not dependent on PKC, and only HB-EGF and NRG cleavage were inhibited by BB94. In contrast, phorbol 12-myristate-13-acetate (TPA) -induced cleavage of HB-EGF, NRG, and TGF-alpha was dependent on PKC and sensitive to BB94 inhibition. LPA led to significant cleavage of only NRG and TGF-alpha and was inhibited by BB94; only LPA-induced NRG cleavage required PKC. Surprisingly, specific inhibition of atypical PKCs zeta and iota [not activated by diacylglycerol (DAG) and calcium] significantly enhanced TPA-induced NRG cleavage. Employed in a high-throughput cloning strategy, our cleavage assay should allow the identification of candidate proteins involved in signal transduction of different

  14. Interaction of a monoclonal antibody against hEGF with a receptor site for EGF

    Energy Technology Data Exchange (ETDEWEB)

    Valente, Sonia; Souto, Beatriz; Balter, Henia; Welling, Mick M.; Roman, Estela; Robles, Ana; Pauwels, Ernest K.J

    1999-11-01

    Epidermal growth factor (EGF) has been detected by radioimmunoassay (RIA) in different body fluids such as serum, amniotic fluid, and urine. Human tumor tissues with EGF receptors (EGF-Rc) may be saturated with EGF, which may be of prognostic value. An RIA was envisaged to measure human epidermal growth factor (hEGF) levels using EGF-Rc as capture agent and a monoclonal antibody anti-hEGF (MAb anti-hEGF) labeled with {sup 125}Iodine as a marker for this binding. The purpose of this work was to study the feasibility of MAb anti-hEGF to detect the receptor binding sites and to investigate the interaction between MAb anti-hEGF and the EGF-Rc. Various binding experiments were performed to study possible interference and interactions in the complex MAb anti-hEGF and the receptor. Affinity constants were determined by means of Scatchard plot analysis to interpret the complex stability challenged with other compounds for a better understanding of the interaction process. Binding constants were of the same order for all the ligands tested separately involving the EGF-Rc, but were significantly higher (t=15.7, p<0.05) for hEGF in its binding to MAb anti-hEGF. It was possible with equilibrium studies and competition experiments to evaluate the interaction of EGF and MAb anti-hEGF with the EGF receptor. This observation makes the MAb anti-hEGF a potential tracer for the quantitation of receptors in vitro, and possibly for the detection of membrane receptors on tumor cells in vivo.

  15. EBP50 inhibits EGF-induced breast cancer cell proliferation by blocking EGFR phosphorylation.

    Science.gov (United States)

    Yao, Wenfang; Feng, Duiping; Bian, Weihua; Yang, Longyan; Li, Yang; Yang, Zhiyu; Xiong, Ying; Zheng, Junfang; Zhai, Renyou; He, Junqi

    2012-11-01

    Ezrin-radixin-moesin-binding phosphoprotein-50 (EBP50) suppresses breast cancer cell proliferation, potentially through its regulatory effect on epidermal growth factor receptor (EGFR) signaling, although the mechanism by which this occurs remains unknown. Thus in our studies, we aimed to determine the effect of EBP50 expression on EGF-induced cell proliferation and activation of EGFR signaling in the breast cancer cell lines, MDA-MB-231 and MCF-7. In MDA-MB-231 cells, which express low levels of EBP50, EBP50 overexpression inhibited EGF-induced cell proliferation, ERK1/2 and AKT phosphorylation. In MCF-7 cells, which express high levels of EBP50, EBP50 knockdown promoted EGF-induced cell proliferation, ERK1/2 and AKT phosphorylation. Knockdown of EBP50 in EBP50-overexpressed MDA-MB-231 cells abrogated the inhibitory effect of EBP50 on EGF-stimulated ERK1/2 phosphorylation and restoration of EBP50 expression in EBP50-knockdown MCF-7 cells rescued the inhibition of EBP50 on EGF-stimulated ERK1/2 phosphorylation, further confirming that the activation of EGF-induced downstream molecules could be specifically inhibited by EBP50 expression. Since EGFR signaling was triggered by EGF ligands via EGFR phosphorylation, we further detected the phosphorylation status of EGFR in the presence or absence of EBP50 expression. Overexpression of EBP50 in MDA-MB-231 cells inhibited EGF-stimulated EGFR phosphorylation, whereas knockdown of EBP50 in MCF-7 cells enhanced EGF-stimulated EGFR phosphorylation. Meanwhile, total expression levels of EGFR were unaffected during EGF stimulation. Taken together, our data shows that EBP50 can suppress EGF-induced proliferation of breast cancer cells by inhibiting EGFR phosphorylation and blocking EGFR downstream signaling in breast cancer cells. These results provide further insight into the molecular mechanism by which EBP50 regulates the development and progression of breast cancer.

  16. Novel multi-targeted ErbB family inhibitor afatinib blocks EGF-induced signaling and induces apoptosis in neuroblastoma.

    Science.gov (United States)

    Mao, Xinfang; Chen, Zhenghu; Zhao, Yanling; Yu, Yang; Guan, Shan; Woodfield, Sarah E; Vasudevan, Sanjeev A; Tao, Ling; Pang, Jonathan C; Lu, Jiaxiong; Zhang, Huiyuan; Zhang, Fuchun; Yang, Jianhua

    2017-01-03

    Neuroblastoma is the most common extracranial solid tumor in children. The ErbB family of proteins is a group of receptor tyrosine kinases that promote the progression of various malignant cancers including neuroblastoma. Thus, targeting them with small molecule inhibitors is a promising strategy for neuroblastoma therapy. In this study, we investigated the anti-tumor effect of afatinib, an irreversible inhibitor of members of the ErbB family, on neuroblastoma. We found that afatinib suppressed the proliferation and colony formation ability of neuroblastoma cell lines in a dose-dependent manner. Afatinib also induced apoptosis and blocked EGF-induced activation of PI3K/AKT/mTOR signaling in all neuroblastoma cell lines tested. In addition, afatinib enhanced doxorubicin-induced cytotoxicity in neuroblastoma cells, including the chemoresistant LA-N-6 cell line. Finally, afatinib exhibited antitumor efficacy in vivo by inducing apoptosis in an orthotopic xenograft neuroblastoma mouse model. Taken together, these results show that afatinib inhibits neuroblastoma growth both in vitro and in vivo by suppressing EGFR-mediated PI3K/AKT/mTOR signaling. Our study supports the idea that EGFR is a potential therapeutic target in neuroblastoma. And targeting ErbB family protein kinases with small molecule inhibitors like afatinib alone or in combination with doxorubicin is a viable option for treating neuroblastoma.

  17. Novel multi-targeted ErbB family inhibitor afatinib blocks EGF-induced signaling and induces apoptosis in neuroblastoma

    Science.gov (United States)

    Mao, Xinfang; Chen, Zhenghu; Zhao, Yanling; Yu, Yang; Guan, Shan; Woodfield, Sarah E.; Vasudevan, Sanjeev A.; Tao, Ling; Pang, Jonathan C.; Lu, Jiaxiong; Zhang, Huiyuan; Zhang, Fuchun; Yang, Jianhua

    2017-01-01

    Neuroblastoma is the most common extracranial solid tumor in children. The ErbB family of proteins is a group of receptor tyrosine kinases that promote the progression of various malignant cancers including neuroblastoma. Thus, targeting them with small molecule inhibitors is a promising strategy for neuroblastoma therapy. In this study, we investigated the anti-tumor effect of afatinib, an irreversible inhibitor of members of the ErbB family, on neuroblastoma. We found that afatinib suppressed the proliferation and colony formation ability of neuroblastoma cell lines in a dose-dependent manner. Afatinib also induced apoptosis and blocked EGF-induced activation of PI3K/AKT/mTOR signaling in all neuroblastoma cell lines tested. In addition, afatinib enhanced doxorubicin-induced cytotoxicity in neuroblastoma cells, including the chemoresistant LA-N-6 cell line. Finally, afatinib exhibited antitumor efficacy in vivo by inducing apoptosis in an orthotopic xenograft neuroblastoma mouse model. Taken together, these results show that afatinib inhibits neuroblastoma growth both in vitro and in vivo by suppressing EGFR-mediated PI3K/AKT/mTOR signaling. Our study supports the idea that EGFR is a potential therapeutic target in neuroblastoma. And targeting ErbB family protein kinases with small molecule inhibitors like afatinib alone or in combination with doxorubicin is a viable option for treating neuroblastoma. PMID:27902463

  18. Regulation of heparin-binding EGF-like growth factor by miR-212 and acquired cetuximab-resistance in head and neck squamous cell carcinoma.

    Directory of Open Access Journals (Sweden)

    Hiromitsu Hatakeyama

    Full Text Available BACKGROUND: We hypothesized that chronic inhibition of epidermal growth factor receptor (EGFR by cetuximab, a monoclonal anti-EGFR antibody, induces up-regulation of its ligands resulting in resistance and that microRNAs (miRs play an important role in the ligand regulation in head and neck squamous cell carcinoma (HNSCC. METHODOLOGY/PRINCIPAL FINDINGS: Genome-wide changes in gene and miR expression were determined in cetuximab-sensitive cell line, SCC1, and its resistant derivative 1Cc8 using DNA microarrays and RT-PCR. The effects of differentially expressed EGFR ligands and miRs were examined by MTS, colony formation, ELISA, and western blot assays. Heparin-binding EGF-like growth factor (HB-EGF and its regulator, miR-212, were differentially expressed with statistical significance when SCC1 and 1Cc8 were compared for gene and miR expression. Stimulation with HB-EGF induced cetuximab resistance in sensitive cell lines. Inhibition of HB-EGF and the addition of miR-212 mimic induced cetuximab sensitivity in resistant cell lines. MicroRNA-212 and HB-EGF expression were inversely correlated in an additional 33 HNSCC and keratinocyte cell lines. Six tumors and 46 plasma samples from HNSCC patients were examined for HB-EGF levels. HB-EGF plasma levels were lower in newly diagnosed HNSCC patients when compared to patients with recurrent disease. CONCLUSIONS/SIGNIFICANCE: Increased expression of HB-EGF due to down-regulation of miR-212 is a possible mechanism of cetuximab resistance. The combination of EGFR ligand inhibitors or miR modulators with cetuximab may improve the clinical outcome of cetuximab therapy in HNSCC.

  19. Fetal antigen 1 (FA1), a circulating member of the epidermal growth factor (EGF) superfamily

    DEFF Research Database (Denmark)

    Jensen, Charlotte Harken; Krogh, T N; Støving, René Klinkby;

    1997-01-01

    We describe an ELISA technique for quantification of fetal antigen 1 (FA1), a glycoprotein belonging to the EGF-superfamily. The ELISA is based on immunospecifically purified polyclonal antibodies and has a dynamic range of 0.7-5.3 ng/ml, intra- and inter-assay C.V.s of less than 3.2% and an aver......We describe an ELISA technique for quantification of fetal antigen 1 (FA1), a glycoprotein belonging to the EGF-superfamily. The ELISA is based on immunospecifically purified polyclonal antibodies and has a dynamic range of 0.7-5.3 ng/ml, intra- and inter-assay C.V.s of less than 3...

  20. The heparin-binding domain of HB-EGF mediates localization to sites of cell-cell contact and prevents HB-EGF proteolytic release

    Energy Technology Data Exchange (ETDEWEB)

    Prince, Robin N.; Schreiter, Eric R.; Zou, Peng; Wiley, H. S.; Ting, Alice Y.; Lee, Richard T.; Lauffenburger, Douglas A.

    2010-07-01

    Heparin-binding EGF-like growth factor (HB-EGF) is a ligand for EGF receptor (EGFR) and possesses the ability to signal in juxtacrine, autocrine and/or paracrine mode, with these alternatives being governed by the degree of proteolytic release of the ligand. Although the spatial range of diffusion of released HB-EGF is restricted by binding heparan-sulfate proteoglycans (HSPGs) in the extracellular matrix and/or cellular glycocalyx, ascertaining mechanisms governing non-released HB-EGF localization is also important for understanding its effects. We have employed a new method for independently tracking the localization of the extracellular EGFlike domain of HB-EGF and the cytoplasmic C-terminus. A striking observation was the absence of the HB-EGF transmembrane proform from the leading edge of COS-7 cells in a wound-closure assay; instead, this protein localized in regions of cell-cell contact. A battery of detailed experiments found that this localization derives from a trans interaction between extracellular HSPGs and the HBEGF heparin-binding domain, and that disruption of this interaction leads to increased release of soluble ligand and a switch in cell phenotype from juxtacrine-induced growth inhibition to autocrine-induced proliferation. Our results indicate that extracellular HSPGs serve to sequester the transmembrane pro-form of HB-EGF at the point of cell-cell contact, and that this plays a role in governing the balance between juxtacrine versus autocrine and paracrine signaling.

  1. A novel taspine derivative, HMQ1611, inhibits breast cancer cell growth via estrogen receptor α and EGF receptor signaling pathways.

    Science.gov (United States)

    Zhan, Yingzhuan; Zhang, Yanmin; Liu, Cuicui; Zhang, Jie; Smith, Wanli W; Wang, Nan; Chen, Yinnan; Zheng, Lei; He, Langchong

    2012-06-01

    Breast cancer is a common cancer with a leading cause of cancer mortality in women. Currently, the chemotherapy for breast cancer is underdeveloped. Here, we report a novel taspine derivative, HMQ1611, which has anticancer effects using in vitro and in vivo breast cancer models. HMQ1611 reduced cancer cell proliferation in four human breast cancer cell lines including MDA-MB-231, SK-BR-3, ZR-75-30, and MCF-7. HMQ1611 more potently reduced growth of estrogen receptor α (ERα)-positive breast cancer cells (ZR-75-30 and MCF-7) than ERα-negative cells (MDA-MB-231 and SK-BR-3). Moreover, HMQ1611 arrested breast cancer cell cycle at S-phase. In vivo tumor xenograft model, treatment of HMQ1611 significantly reduced tumor size and weight compared with vehicles. We also found that HMQ1611 reduced ERα expression and inhibited membrane ERα-mediated mitogen-activated protein kinase (MAPK) signaling following the stimulation of cells with estrogen. Knockdown of ERα by siRNA transfection in ZR-75-30 cells attenuated HMQ1611 effects. In contrast, overexpression of ERα in MDA-MB-231 cells enhanced HMQ1611 effects, suggesting that ERα pathway mediated HMQ1611's inhibition of breast cancer cell growth in ERα-positive breast cancer. HMQ1611 also reduced phosphorylation of EGF receptor (EGFR) and its downstream signaling players extracellular signal-regulated kinase (ERK)1/2 and AKT activation both in ZR-75-30 and MDA-MB-231 cells. These results showed that the novel compound HMQ1611 had anticancer effects, and partially via ERα and/or EGFR signaling pathways, suggesting that HMQ1611 may be a potential novel candidate for human breast cancer intervention.

  2. Effects of in vivo administration of epidermal growth factor (EGF) on uterine contractility, prostaglandin production and timing of parturition in rats.

    Science.gov (United States)

    Ribeiro, M L; Farina, M; Aisemberg, J; Franchi, A

    2003-10-01

    Prostaglandins synthesized by cyclooxygenases elicit uterine contractions during labour. Nitric oxide synthases (NOS) produce nitric oxide (NO), which maintains uterine quiescence during pregnancy. Epidermal growth factor (EGF) interacts with prostaglandins and NO in many biological systems. The aim of this work was to study the effect of the in vivo administration of EGF on uterine contractility, prostaglandin production and timing of parturition in rats. EGF was injected into the uterine lumen of pregnant rats on day 20, 21 or 22 of gestation. Intra-uterine administration of 500 ng EGF on day 21 of gestation delayed parturition for 18 h compared with control rats. Administration of EGF was able to: (i) reduce cyclooxygenase expression in the uterus (determined by western blot analysis) and production of prostaglandins by the uterus (evaluated by conversion of [(14)C]arachidonate to labelled prostaglandins); (ii) decrease prostaglandin concentrations in amniotic fluid (radioimmunoassay); (iii) increase NO production (evaluated by conversion of [(14)C]arginine into [(14)C]citrulline); (iv) increase serum progesterone concentrations to more than control concentrations (Ponset of delivery. This in vivo effect raises the question of whether exogenous EGF plays a role in the initiation of parturition.

  3. Interaction of a monoclonal antibody against hEGF with a receptor site for EGF.

    Science.gov (United States)

    Valente, S; Souto, B; Balter, H; Welling, M M; Román, E; Robles, A; Pauwels, E K

    1999-11-01

    Epidermal growth factor (EGF) has been detected by radioimmunoassay (RIA) in different body fluids such as serum, amniotic fluid, and urine. Human tumor tissues with EGF receptors (EGF-Rc) may be saturated with EGF, which may be of prognostic value. An RIA was envisaged to measure human epidermal growth factor (hEGF) levels using EGF-Rc as capture agent and a monoclonal antibody anti-hEGF (MAb anti-hEGF) labeled with 125Iodine as a marker for this binding. The purpose of this work was to study the feasibility of MAb anti-hEGF to detect the receptor binding sites and to investigate the interaction between MAb anti-hEGF and the EGF-Rc. Various binding experiments were performed to study possible interference and interactions in the complex MAb anti-hEGF and the receptor. Affinity constants were determined by means of Scatchard plot analysis to interpret the complex stability challenged with other compounds for a better understanding of the interaction process. Binding constants were of the same order for all the ligands tested separately involving the EGF-Rc, but were significantly higher (t = 15.7, p anti-hEGF. It was possible with equilibrium studies and competition experiments to evaluate the interaction of EGF and MAb anti-hEGF with the EGF receptor. This observation makes the MAb anti-hEGF a potential tracer for the quantitation of receptors in vitro, and possibly for the detection of membrane receptors on tumor cells in vivo.

  4. Dihydrotestosterone Potentiates EGF-Induced ERK Activation by Inducing SRC in Fetal Lung Fibroblasts

    Science.gov (United States)

    Smith, Susan M.; Murray, Sandy; Pham, Lucia D.; Minoo, Parviz; Nielsen, Heber C.

    2014-01-01

    Lung maturation is regulated by interactions between mesenchymal and epithelial cells, and is delayed by androgens. Fibroblast–Type II cell communications are dependent on extracellular signal-regulated kinases (ERK) 1/2 activation by the ErbB receptor ligands epidermal growth factor (EGF), transforming growth factor (TGF)-α, and neuregulin (Nrg). In other tissues, dihydrotestosterone (DHT) has been shown to activate SRC by a novel nontranscriptional mechanism, which phosphorylates EGF receptors to potentiate EGF-induced ERK1/2 activation. This study sought to determine if DHT potentiates EGFR signaling by a nontranscriptional mechanism. Embryonic day (E)17 fetal lung cells were isolated from dams treated with or without DHT since E12. Cells were exposed to 30 ng/ml DHT for periods of 30 minutes to 3 days before being stimulated with 100 ng/ml EGF, TGF-α, or Nrg for up to 30 minutes. Lysates were immunoblotted for ErbB and SRC pathway signaling intermediates. DHT increased ERK1/2 activation by EGF, TGF-α, and Nrg in fibroblasts and Type II cells. Characterization in fibroblasts showed that potentiation of the EGF pathway was significant after 60 minutes of DHT exposure and persisted in the presence of the translational inhibitor cycloheximide. SRC and EGF receptor phosphorylation was increased by DHT, as was EGF-induced SHC1 phosphorylation and subsequent association with GRB2. Finally, SRC silencing, SRC inhibition with PP2, and overexpression of a dominant-negative SRC each prevented DHT from increasing EGF-induced ERK1/2 phosphorylation. These results suggest that DHT activates SRC to potentiate the signaling pathway leading from the EGF receptor to ERK activation in primary fetal lung fibroblasts. PMID:24484548

  5. Dietary Supplementation of Astragalus Polysaccharides Enhanced Immune Components and Growth Factors EGF and IGF-1 in Sow Colostrum.

    Science.gov (United States)

    Tan, Lunbo; Wei, Ting; Yuan, Anwen; He, Jun; Liu, Jinhui; Xu, Daojun; Yang, Qing

    2017-01-01

    Colostrum is the main external resource providing piglets with nutrients and maternal immune molecules. Astragalus polysaccharides (APS) have been used as immunopotentiators in vitro and several animal models. This study aimed to determine the effects of APS on immune factors in sow colostrum and milk. The sow diet was supplemented with APS one week before the expected delivery date. Colostrum and milk were collected and designated as 0 h- (onset of parturition), 12 h-, and 24 h-colostrum and 36 h-milk postpartum. Samples were measured using porcine immunoglobulin (Ig) G, IgM, classical swine fever virus antibody (CSFV Ab), epidermal growth factor (EGF), and insulin-like growth factor- (IGF-) 1 ELISA Quantitation Kits. Dietary supplementation of APS significantly enhanced the presence of IgG, IgM, EGF, and IGF-1 in 0 h-colostrum (P colostrum and/or milk; and status of some specific vaccination could be determined through using colostrum or early milk in sow.

  6. Dietary Supplementation of Astragalus Polysaccharides Enhanced Immune Components and Growth Factors EGF and IGF-1 in Sow Colostrum

    Science.gov (United States)

    Tan, Lunbo; Wei, Ting; Yuan, Anwen; He, Jun; Liu, Jinhui

    2017-01-01

    Colostrum is the main external resource providing piglets with nutrients and maternal immune molecules. Astragalus polysaccharides (APS) have been used as immunopotentiators in vitro and several animal models. This study aimed to determine the effects of APS on immune factors in sow colostrum and milk. The sow diet was supplemented with APS one week before the expected delivery date. Colostrum and milk were collected and designated as 0 h- (onset of parturition), 12 h-, and 24 h-colostrum and 36 h-milk postpartum. Samples were measured using porcine immunoglobulin (Ig) G, IgM, classical swine fever virus antibody (CSFV Ab), epidermal growth factor (EGF), and insulin-like growth factor- (IGF-) 1 ELISA Quantitation Kits. Dietary supplementation of APS significantly enhanced the presence of IgG, IgM, EGF, and IGF-1 in 0 h-colostrum (P < 0.001). The blocking rates of CSFV Ab were increased in samples from APS-supplemented sow when compared to those from the matched samples without APS treatment. The results indicate that supplement of APS could improve the immune components in sow colostrum and/or milk; and status of some specific vaccination could be determined through using colostrum or early milk in sow. PMID:28164139

  7. Construction of Plant Expression Vector for Recombinant Human Epidermal Growth Factor (hEGF)%重组人表皮生长因子(hEGF)植物表达载体的构建

    Institute of Scientific and Technical Information of China (English)

    武玉永; 刘东东; 信凯; 姚庆收

    2013-01-01

    [Objective] This study aimed to construct plant expression vector for recombinant human epidermal growth factor (hEGF) and further to provide a basis for the expression of hEGF in peanut hairy root system.[Method] According to the hEGF sequence in GenBank,hEGF was synthesized artificially; subsequently,hEGF gene was ligated with green fluorescent protein (GFP) gene,and their ligation product was then amplified with primers flanked with corresponding endonuclease cleavage sites,followed by double digestion by Sal I and EcoR I of the amplified products; next,pRI 101 AN DNA was extracted and digested by both Sal I and EcoR I;susequently,the digestion products of hEGF and GFP ligation fragment by Sal I and EcoR I and the digestion products of pRI 101 AN plasmid DNA by Sal I and EcoR I were ligated,and their ligation product was transformed into Escherichia coil XL10-Gold,followed by extraction of DNA from the recombinants exhibiting green fluorescence,which was then identified by enzymatic digestion and PCR,and the verified recombinant plasmid DNA was named pBZG101.[Result] Human epidermal growth factor gene (hEGF) and green fluorescent protein gene (GFP) were successfully ligated,and their ligation fragment was successfully ligated to pRI 101 AN DNA,finally with the acquirement of the plant expression vector for recombinant human epidermal growth factor-(pBZG101).[Conclusion] The plant expression vector for recombinant human epidermal growth factor-(pBZG101)-was successfully constructed in this study.%[目的]构建重组人表皮生长因子的植物用表达载体,为应用花生毛状根表达系统表达人表皮生长因子(hEGF)奠定基础.[方法]在GenBank中找到hEGF基因序列,并人工合成;将含hEGF基因与绿色荧光蛋白(GFP)的基因连接,用加相应接头的引物扩增得到这2个基因的片段,然后用Sal I和EcoR I的进行双酶切并回收;提取质粒pRI 101 AN DNA,并用Sal I和EcoR I对其进行双酶切并回

  8. The LIN-15A and LIN-56 transcriptional regulators interact to negatively regulate EGF/Ras signaling in Caenorhabditis elegans vulval cell-fate determination.

    Science.gov (United States)

    Davison, Ewa M; Saffer, Adam M; Huang, Linda S; DeModena, John; Sternberg, Paul W; Horvitz, H Robert

    2011-03-01

    The restricted expression of epidermal growth factor (EGF) family ligands is important for proper development and for preventing cancerous growth in mammals. In Caenorhabditis elegans, the class A and B synthetic multivulva (synMuv) genes redundantly repress expression of lin-3 EGF to negatively regulate Ras-mediated vulval development. The class B synMuv genes encode proteins homologous to components of the NuRD and Myb-MuvB/dREAM transcriptional repressor complexes, indicating that they likely silence lin-3 EGF through chromatin remodeling. The two class A synMuv genes cloned thus far, lin-8 and lin-15A, both encode novel proteins. The LIN-8 protein is nuclear. We have characterized the class A synMuv gene lin-56 and found it to encode a novel protein that shares a THAP-like C(2)CH motif with LIN-15A. Both the LIN-56 and LIN-15A proteins localize to nuclei. Wild-type levels of LIN-56 require LIN-15A, and wild-type levels and/or localization of LIN-15A requires LIN-56. Furthermore, LIN-56 and LIN-15A interact in the yeast two-hybrid system. We propose that LIN-56 and LIN-15A associate in a nuclear complex that inhibits vulval specification by repressing lin-3 EGF expression.

  9. Harnessing Novel Secreted Inhibitors of EGF Receptor Signaling for Breast Cancer Treatment

    Science.gov (United States)

    2008-04-01

    and P372S mutants of Argos by secretion from baculovirus-infected Sf9 cells, and used Biacore to assess the binding of these mutated proteins to...generated and amplified according to the manufacturer’s instructions. For protein puri- fication, 1 liter of Sf9 cells were infected with each correspond...infected Spodoptera frugiperda Sf9 cells, using the amino-terminal BiP signal sequence to direct 9 secretion of the protein into the medium. The

  10. Preparation of epidermal growth factor (EGF) conjugated iron oxide nanoparticles and their internalization into colon cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Creixell, Mar [Department of Chemical Engineering, University of Puerto Rico, Mayagueez Campus, P.O. Box 9000, Mayagueez, PR 00681 (Puerto Rico); Department of Electronics, Faculty of Physics, University of Barcelona, Av. Diagonal 647, 08028 Barcelona (Spain); Herrera, Adriana P.; Ayala, Vanessa; Latorre-Esteves, Magda [Department of Chemical Engineering, University of Puerto Rico, Mayagueez Campus, P.O. Box 9000, Mayagueez, PR 00681 (Puerto Rico); Perez-Torres, Marianela [Department of Pharmaceutical Sciences, University of Puerto Rico-Medical Sciences Campus, PO Box 365067, San Juan, PR 00936 (Puerto Rico); Torres-Lugo, Madeline [Department of Chemical Engineering, University of Puerto Rico, Mayagueez Campus, P.O. Box 9000, Mayagueez, PR 00681 (Puerto Rico); Rinaldi, Carlos, E-mail: carlos.rinaldi@upr.ed [Department of Chemical Engineering, University of Puerto Rico, Mayagueez Campus, P.O. Box 9000, Mayagueez, PR 00681 (Puerto Rico)

    2010-08-15

    Epidermal growth factor (EGF) was conjugated with carboxymethyldextran (CMDx) coated iron oxide magnetic nanoparticles using carbodiimide chemistry to obtain magnetic nanoparticles that target the epidermal growth factor receptor (EGFR). Epidermal growth factor modified magnetic nanoparticles were colloidally stable when suspended in biological buffers such as PBS and cell culture media. Both targeted and non-targeted nanoparticles were incubated with CaCo-2 cancer cells, known to overexpress EGFR. Nanoparticle localization within the cell was visualized by confocal laser scanning microscopy and light microscopy using Prussian blue stain. Results showed that targeted magnetic nanoparticles were rapidly accumulated in both flask-shaped small vesicles and large circular endocytic structures. Internalization patterns suggest that both clathrin-dependent and clathrin-independent receptors mediated endocytosis mechanisms are responsible for nanoparticle internalization.

  11. Preparation of epidermal growth factor (EGF) conjugated iron oxide nanoparticles and their internalization into colon cancer cells

    Science.gov (United States)

    Creixell, Mar; Herrera, Adriana P.; Ayala, Vanessa; Latorre-Esteves, Magda; Pérez-Torres, Marianela; Torres-Lugo, Madeline; Rinaldi, Carlos

    2010-08-01

    Epidermal growth factor (EGF) was conjugated with carboxymethyldextran (CMDx) coated iron oxide magnetic nanoparticles using carbodiimide chemistry to obtain magnetic nanoparticles that target the epidermal growth factor receptor (EGFR). Epidermal growth factor modified magnetic nanoparticles were colloidally stable when suspended in biological buffers such as PBS and cell culture media. Both targeted and non-targeted nanoparticles were incubated with CaCo-2 cancer cells, known to overexpress EGFR. Nanoparticle localization within the cell was visualized by confocal laser scanning microscopy and light microscopy using Prussian blue stain. Results showed that targeted magnetic nanoparticles were rapidly accumulated in both flask-shaped small vesicles and large circular endocytic structures. Internalization patterns suggest that both clathrin-dependent and clathrin-independent receptors mediated endocytosis mechanisms are responsible for nanoparticle internalization.

  12. Mobility of tethering factor EEA1 on endosomes is decreased upon stimulation of EGF receptor endocytosis in HeLa cells

    Energy Technology Data Exchange (ETDEWEB)

    Kosheverova, Vera V., E-mail: kosheverova_vera@incras.ru [Institute of Cytology of RAS, 4, Tikhoretsky Ave, St. Petersburg, 194064 (Russian Federation); Kamentseva, Rimma S., E-mail: rkamentseva@yandex.ru [Institute of Cytology of RAS, 4, Tikhoretsky Ave, St. Petersburg, 194064 (Russian Federation); St. Petersburg State University, 7-9, Universitetskaya nab, St. Petersburg, 199034 (Russian Federation); Gonchar, Ilya V., E-mail: ample@mail.ru [Institute of Cytology of RAS, 4, Tikhoretsky Ave, St. Petersburg, 194064 (Russian Federation); Kharchenko, Marianna V., E-mail: mariannakharchenko@gmail.com [Institute of Cytology of RAS, 4, Tikhoretsky Ave, St. Petersburg, 194064 (Russian Federation); Kornilova, Elena S., E-mail: lenkor@mail.cytspb.rssi.ru [Institute of Cytology of RAS, 4, Tikhoretsky Ave, St. Petersburg, 194064 (Russian Federation); St. Petersburg State University, 7-9, Universitetskaya nab, St. Petersburg, 199034 (Russian Federation); Department of Medical Physics, Peter the Great St. Petersburg Polytechnic University, 29, Polytechnicheskaya, St.Petersburg, 195251 (Russian Federation)

    2016-04-22

    Tethering factor EEA1, mediating homotypic fusion of early endosomes, was shown to be localized in membrane-bound state both in serum-deprived and stimulated for EGF receptor endocytosis cells. However, it is not known whether dynamics behavior of EEA1 is affected by EGF stimulation. We investigated EEA1 cytosol-to-membrane exchange rate in interphase HeLa cells by FRAP analysis. The data obtained fitted two-states binding model, with the bulk of membrane-associated EEA1 protein represented by the mobile fraction both in serum-starved and EGF-stimulated cells. Fast recovery state had similar half-times in the two cases: about 1.6 s and 2.8 s, respectively. However, the recovery half-time of slowly cycled EEA1 fraction significantly increased in EGF-stimulated comparing to serum-starved cells (from 21 to 99 s). We suppose that the retardation of EEA1 fluorescence recovery upon EGF-stimulation may be due to the increase of activated Rab5 on endosomal membranes, the growth of the number of tethering events between EEA1-positive vesicles and their clustering. - Highlights: • EEA1 mobility was compared in serum-starved and EGF-stimulated interphase HeLa cells. • FRAP analysis revealed fast and slow components of EEA1 recovery in both cases. • Stimulation of EGFR endocytosis did not affect fast EEA1 turnover. • EGF stimulation significantly increased half-time of slowly exchanged EEA1 fraction.

  13. A proteomics strategy to elucidate functional protein-protein interactions applied to EGF signaling

    DEFF Research Database (Denmark)

    Blagoev, B.; Kratchmarova, I.; Ong, S.E.

    2003-01-01

    Mass spectrometry-based proteomics can reveal protein-protein interactions on a large scale, but it has been difficult to separate background binding from functionally important interactions and still preserve weak binders. To investigate the epidermal growth factor receptor (EGFR) pathway, we...

  14. Mycalamide A Shows Cytotoxic Properties and Prevents EGF-Induced Neoplastic Transformation through Inhibition of Nuclear Factors

    Science.gov (United States)

    Dyshlovoy, Sergey A.; Fedorov, Sergey N.; Kalinovsky, Anatoly I.; Shubina, Larisa K.; Bokemeyer, Carsten; Stonik, Valentin A.; Honecker, Friedemann

    2012-01-01

    Mycalamide A, a marine natural compound previously isolated from sponges, is known as a protein synthesis inhibitor with potent antitumor activity. However, the ability of this compound to prevent malignant transformation of cells has never been examined before. Here, for the first time, we report the isolation of mycalamide A from ascidian Polysincraton sp. as well as investigation of its cancer preventive properties. In murine JB6 Cl41 P+ cells, mycalamide A inhibited epidermal growth factor (EGF)-induced neoplastic transformation, and induced apoptosis at subnanomolar or nanomolar concentrations. The compound inhibited transcriptional activity of the oncogenic nuclear factors AP-1 and NF-κB, a potential mechanism of its cancer preventive properties. Induction of phosphorylation of the kinases MAPK p38, JNK, and ERK was also observed at high concentrations of mycalamide A. The drug shows promising potential for both cancer-prevention and cytotoxic therapy and should be further developed. PMID:22822368

  15. Manipulating the Lateral Diffusion of Surface-Anchored EGF Demonstrates that Receptor Clustering Modulates its Phosphorylation Levels

    Energy Technology Data Exchange (ETDEWEB)

    Stabley, Daniel [Emory University; Retterer, Scott T [ORNL; Marshal, Stephen [Emory University; Salaita, Khalid [Emory University

    2013-01-01

    Upon activation, the epidermal growth factor (EGF) receptor becomes phosphorylated and triggers a vast signaling network that has profound effects on cell growth. The EGF receptor is observed to assemble into clusters after ligand binding and tyrosine kinase autophosphorylation, but the role of these assemblies in the receptor signaling pathway remains unclear. To address this question, we measured the phosphorylation of EGFR when the EGF ligand was anchored onto laterally mobile and immobile surfaces. We found that cells generated clusters of ligand-receptor complex on mobile EGF surfaces, and generated a lower ratio of phosphorylated EGFR to EGF than when compared to immobilized EGF that is unable to cluster. This result was verified by tuning the lateral assembly of ligand-receptor complexes on the surface of living cells using patterned supported lipid bilayers. Nanoscale metal lines fabricated into the supported membrane constrained lipid diffusion and EGF receptor assembly into micron and sub-micron scale corrals. Single cell analysis indicated that clustering impacts EGF receptor activation, and larger clusters (> 1 m2) of ligand-receptor complex generated lower EGF receptor phosphorylation per ligand than smaller assemblies (< 1 m2) in HCC1143 cells that were engaged to ligand-functionalized surfaces. We investigated EGFR clustering by treating cells with compounds that disrupt the cytoskeleton (Latrunculin-B), clathrin-mediated endocytosis (Pitstop2), and inhibit EGFR activation (Gefitinib). These results help elucidate the nature of large-scale EGFR clustering, thus underscoring the general significance of receptor spatial organization in tuning function.

  16. CIMAvax-EGF: A New Therapeutic Vaccine for Advanced Non-Small Cell Lung Cancer Patients

    Science.gov (United States)

    Saavedra, Danay; Crombet, Tania

    2017-01-01

    Lung cancer is the common fatal illness with the highest incidence and mortality globally. Epidermal growth factor receptor overexpression by tumor cells is associated with uncontrolled proliferation, angiogenesis, anti-apoptotic signals, metastization, and invasiveness. CIMAvax-EGF vaccine consists of a chemical conjugate of the EGF with the P64 protein derived from the Meningitis B bacteria and Montanide ISA 51, as adjuvant. The vaccine is projected to induce antibodies against EGF that results in EGF withdrawal. CIMAvax-EGF demonstrated to be safe and immunogenic in advanced non-small cell lung cancer (NSCLC) patients. The efficacy study was an open-label, multicentric Phase III clinical trial, which enrolled 405 advanced NSCLC patients. Patients with proven stage IIIB/IV NSCLC, who had completed four to six cycles of chemotherapy (CTP) were randomized to receive CIMAvax-EGF or best supportive care. CIMAvax-EGF resulted in a significantly larger overall survival in patients receiving at least four doses. High EGF concentration at baseline was a good predictive biomarker of the vaccine activity and a poor prognostic biomarker for the non-treated population. The proportion of CD8+CD28− cells, CD4 cells, and the CD4/CD8 ratio after first-line CTP was also associated with CIMAvax-EGF clinical benefit. After completing the Phase III, a Phase IV trial was done where the vaccine was administered in primary care units. Administering the vaccine at primary care institutions granted better access and treatment compliance. Safety was confirmed. Several clinical trials are currently ongoing to validate EGF as a predictive biomarker of CIMAvax-EGF efficacy.

  17. GEP100/Arf6 is required for epidermal growth factor-induced ERK/Rac1 signaling and cell migration in human hepatoma HepG2 cells.

    Directory of Open Access Journals (Sweden)

    ZhenZhen Hu

    Full Text Available BACKGROUND: Epidermal growth factor (EGF signaling is implicated in the invasion and metastasis of hepatoma cells. However, the signaling pathways for EGF-induced motility of hepatoma cells remain undefined. METHODOLOGY/PRINCIPAL FINDINGS: We found that EGF dose-dependently stimulated the migration of human hepatoma cells HepG2, with the maximal effect at 10 ng/mL. Additionally, EGF increased Arf6 activity, and ectopic expression of Arf6 T27N, a dominant negative Arf6 mutant, largely abolish EGF-induced cell migration. Blocking GEP100 with GEP100 siRNA or GEP100-△PH, a pleckstrin homology (PH domain deletion mutant of GEP100, blocked EGF-induced Arf6 activity and cell migration. EGF also increased ERK and Rac1 activity. Ectopic expression GEP100 siRNA, GEP100-△PH, or Arf6-T27N suppressed EGF-induced ERK and Rac1 activity. Furthermore, blocking ERK signaling with its inhibitor U0126 remarkably inhibited both EGF-induced Rac1 activation as well as cell migration, and ectopic expression of inactive mutant form of Rac1 (Rac1-T17N also largely abolished EGF-induced cell migration. CONCLUSIONS/SIGNIFICANCE: Taken together, this study highlights the function of the PH domain of GEP100 and its regulated Arf6/ERK/Rac1 signaling cascade in EGF-induced hepatoma cell migration. These findings could provide a rationale for designing new therapy based on inhibition of hepatoma metastasis.

  18. Epidermal growth factor (EGF) ligand release by substrate-specific a disintegrin and metalloproteases (ADAMs) involves different protein kinase C (PKC) isoenzymes depending on the stimulus.

    Science.gov (United States)

    Dang, Michelle; Dubbin, Karen; D'Aiello, Antonio; Hartmann, Monika; Lodish, Harvey; Herrlich, Andreas

    2011-05-20

    The dysregulation of EGF family ligand cleavage has severe consequences for the developing as well as the adult organism. Therefore, their production is highly regulated. The limiting step is the ectodomain cleavage of membrane-bound precursors by one of several a disintegrin and metalloprotease (ADAM) metalloproteases, and understanding the regulation of cleavage is an important goal of current research. We have previously reported that in mouse lung epithelial cells, the pro-EGF ligands TGFα, neuregulin 1β (NRG), and heparin-binding EGF are differentially cleaved depending on the cleavage stimulus (Herrlich, A., Klinman, E., Fu, J., Sadegh, C., and Lodish, H. (2008) FASEB J.). In this study in mouse embryonic fibroblasts that lack different ADAMs, we show that induced cleavage of EGF ligands can involve the same substrate-specific metalloprotease but does require different stimulus-dependent signaling pathways. Cleavage was stimulated by phorbol ester (12-O-tetradecanoylphorbol-13-acetate (TPA), a mimic of diacylglycerol and PKC activator), hypertonic stress, lysophosphatidic acid (LPA)-induced G protein-coupled receptor activation, or by ionomycin-induced intracellular calcium release. Although ADAMs showed substrate preference (ADAM17, TGFα and heparin-binding EGF; and ADAM9, NRG), substrate cleavage differed substantially with the stimulus, and cleavage of the same substrate depended on the presence of different, sometimes multiple, PKC isoforms. For instance, classical PKC was required for TPA-induced but not hypertonic stress-induced cleavage of all EGF family ligands. Inhibition of PKCζ enhanced NRG release upon TPA stimulation, but it blocked NRG release in response to hypertonic stress. Our results suggest a model in which substantial regulation of ectodomain cleavage occurs not only on the metalloprotease level but also on the level of the substrate or of a third protein.

  19. Epidermal growth factor signaling induces behavioral quiescence in Caenorhabditis elegans.

    Science.gov (United States)

    Van Buskirk, Cheryl; Sternberg, Paul W

    2007-10-01

    The epidermal growth factor receptor (EGFR)/ErbB receptor tyrosine kinases regulate several aspects of development, including the development of the mammalian nervous system. ErbB signaling also has physiological effects on neuronal function, with influences on synaptic plasticity and daily cycles of activity. However, little is known about the effectors of EGFR activation in neurons. Here we show that EGF signaling has a nondevelopmental effect on behavior in Caenorhabditis elegans. Ectopic expression of the EGF-like ligand LIN-3 at any stage induces a reversible cessation of feeding and locomotion. These effects are mediated by neuronal EGFR (also called LET-23) and phospholipase C-gamma (PLC-gamma), diacylglycerol-binding proteins, and regulators of synaptic vesicle release. Activation of EGFR within a single neuron, ALA, is sufficient to induce a quiescent state. This pathway modulates the cessation of pharyngeal pumping and locomotion that normally occurs during the lethargus period that precedes larval molting. Our results reveal an evolutionarily conserved role for EGF signaling in the regulation of behavioral quiescence.

  20. Growth Factor Mediated Signaling in Pancreatic Pathogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Nandy, Debashis; Mukhopadhyay, Debabrata, E-mail: mukhopadhyay.debabrata@mayo.edu [Department of Biochemistry and Molecular Biology, College of Medicine, Mayo Clinic, 200 First Street SW, Guggenheim 1321C, Rochester, MN 55905 (United States)

    2011-02-24

    Functionally, the pancreas consists of two types of tissues: exocrine and endocrine. Exocrine pancreatic disorders mainly involve acute and chronic pancreatitis. Acute pancreatitis typically is benign, while chronic pancreatitis is considered a risk factor for developing pancreatic cancer. Pancreatic carcinoma is the fourth leading cause of cancer related deaths worldwide. Most pancreatic cancers develop in the exocrine tissues. Endocrine pancreatic tumors are more uncommon, and typically are less aggressive than exocrine tumors. However, the endocrine pancreatic disorder, diabetes, is a dominant cause of morbidity and mortality. Importantly, different growth factors and their receptors play critical roles in pancreatic pathogenesis. Hence, an improved understanding of how various growth factors affect pancreatitis and pancreatic carcinoma is necessary to determine appropriate treatment. This chapter describes the role of different growth factors such as vascular endothelial growth factor (VEGF), insulin-like growth factor (IGF), platelet derived growth factor (PDGF), fibroblast growth factor (FGF), epidermal growth factor (EGF), and transforming growth factor (TGF) in various pancreatic pathophysiologies. Finally, the crosstalk between different growth factor axes and their respective signaling mechanisms, which are involved in pancreatitis and pancreatic carcinoma, are also discussed.

  1. Growth Factor Mediated Signaling in Pancreatic Pathogenesis

    Directory of Open Access Journals (Sweden)

    Debashis Nandy

    2011-02-01

    Full Text Available Functionally, the pancreas consists of two types of tissues: exocrine and endocrine. Exocrine pancreatic disorders mainly involve acute and chronic pancreatitis. Acute pancreatitis typically is benign, while chronic pancreatitis is considered a risk factor for developing pancreatic cancer. Pancreatic carcinoma is the fourth leading cause of cancer related deaths worldwide. Most pancreatic cancers develop in the exocrine tissues. Endocrine pancreatic tumors are more uncommon, and typically are less aggressive than exocrine tumors. However, the endocrine pancreatic disorder, diabetes, is a dominant cause of morbidity and mortality. Importantly, different growth factors and their receptors play critical roles in pancreatic pathogenesis. Hence, an improved understanding of how various growth factors affect pancreatitis and pancreatic carcinoma is necessary to determine appropriate treatment. This chapter describes the role of different growth factors such as vascular endothelial growth factor (VEGF, insulin-like growth factor (IGF, platelet derived growth factor (PDGF, fibroblast growth factor (FGF, epidermal growth factor (EGF, and transforming growth factor (TGF in various pancreatic pathophysiologies. Finally, the crosstalk between different growth factor axes and their respective signaling mechanisms, which are involved in pancreatitis and pancreatic carcinoma, are also discussed.

  2. RETINOIC ACID INDUCTION OF CLEFT PALATE IN EGF AND TGF-ALPHA KNOCKOUT MICE: STAGE SPECIFIC INFLUENCES OF GROWTH FACTOR EXPRESSION

    Science.gov (United States)

    ABBOTT, B. D., LEFFLER, K.E. AND BUCKALEW, A.R, Reproductive Toxicology Division, NHEERL, ORD, US EPA, Research Triangle Park, North Carolina. Retinoic acid induction of cleft palate (CP) in EGF and TGF knockout mice: Stage specific influences of growth factor expression.<...

  3. The anti-tumor effect of cross-reacting material 197, an inhibitor of heparin-binding EGF-like growth factor, in human resistant ovarian cancer

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Xiao-han; Deng, Suo; Li, Meng [Department of Gynecology and Obstetrics, The First Affiliated Hospital of Harbin Medical University, Harbin (China); Lu, Mei-song, E-mail: lumeisong0417@163.com [Department of Gynecology and Obstetrics, The First Affiliated Hospital of Harbin Medical University, Harbin (China)

    2012-06-15

    Highlights: Black-Right-Pointing-Pointer HB-EGF over-expression in A2780/Taxol, A2780/CDDP cells and the matched xenografts. Black-Right-Pointing-Pointer CRM197 induces enhanced apoptosis in A2780/Taxol and A2780/CDDP cells. Black-Right-Pointing-Pointer CRM197 arrests A2780/Taxol and A2780/CDDP cells at G0/G1 phase. Black-Right-Pointing-Pointer CRM197 suppressed the A2780/Taxol and A2780/CDDP growth of xenografts. -- Abstract: Heparin-binding epidermal growth factor-like growth factor (HB-EGF) is a promising target for ovarian cancer therapy. Cross-reacting material 197 (CRM197), a specific HB-EGF inhibitor, has been proven to represent possible chemotherapeutic agent for ovarian cancer. However, the effect of CRM197 on the resistant ovarian carcinoma cells has not been sufficiently elucidated. Here, we found that HB-EGF was over-expressed in a paclitaxel-resistant human ovarian carcinoma cell line (A2780/Taxol) and a cisplatin-resistant cell line (A2780/CDDP), as well as the xenograft mouse tissue samples with these cells. To investigate the possible significance of the HB-EGF over-expression in A2780/Taxol and A2780/CDDP cells, we inhibited HB-EGF expression by CRM197 to investigate the effect of CRM197 treatment on these cells. We observed that CRM197 significantly induced anti-proliferative activity in a dose-dependent manner with the cell-cycle arrest at the G0/G1 phase and enhanced apoptosis in A2780/Taxol and A2780/CDDP cells. The sensitive ovarian carcinoma parental cell line (A2780), A2780/Taxol and A2780/CDDP cells formed tumors in nude mice, and enhanced tumorigenicity was observed in drug-resistant tumors. Furthermore, we observed that CRM197 significantly suppressed the growth of drug-resistant ovarian cancer xenografts in vivo (p < 0.001). These results suggest that CRM197 as an HB-EGF-targeted agent has potent anti-tumor activity in paclitaxel- and cisplatin-resistant ovarian cancer which over-express HB-EGF.

  4. Can signal peptide-CUB-EGF domain-containing protein (SCUBE) levels be a marker of angiogenesis in patients with psoriasis?

    Science.gov (United States)

    Capkin, Arzu Aydın; Demir, Selim; Mentese, Ahmet; Bulut, Çağlar; Ayar, Ahmet

    2017-04-01

    Angiogenesis is an important process being involved in the pathogenesis of psoriasis and promises new potential parameter for diagnosis and screening of treatment. This study investigated the levels of signal peptide-CUB-EGF (epidermal growth factor-like protein) family domain-containing protein (SCUBE) 1 and 3. Potential value as a novel marker of angiogenesis in patients with psoriasis is also evaluated by assessing possible relation of SCUBE-1 and 3 with disease activity in conjunction with vascular endothelial growth factor (VEGF) levels, as an established marker of angiogenesis. Forty-eight patients with psoriasis (aged >18 years) and 48 age- and gender-matched healthy controls were included. Detailed information was obtained through history and physical examination. Psoriasis area and severity index (PASI) scores were calculated. Blood SCUBE 1 and 3, and VEGF levels were measured by enzyme-linked immunosorbent assay. The mean PASI score of the patients was 6.7 ± 4.1. Patients' serum SCUBE 1 and 3 and VEGF levels were significantly higher than those of the controls (P = 0.001). The sensitivity and specificity were calculated as 83 and 62% for the 0.67 ng/ml cut-off level of SCUBE 1, and 63 and 71% for the 2.57 ng/ml cut-off level of SCUBE 3, respectively. A cut-off VEGF level of 310 ng/mL predicted the presence of psoriasis with a sensitivity of 50% and specificity of 77%. The results of this pioneering study indicate that SCUBE protein family appears to have a probable role in the pathogenesis and angiogenesis development in psoriasis and SCUBE 1 and 3 may be novel markers of angiogenesis in psoriasis.

  5. ROS, MAPK/ERK and PKC play distinct roles in EGF-stimulated human corneal cell proliferation and migration.

    Science.gov (United States)

    Huo, Y-N; Chen, W; Zheng, X-X

    2015-11-08

    Cornea is at the outermost surface of eye globe, and it easily receives damage from ultraviolet light exposure, physiology wounding, and infections. It is essential to understand the mechanisms controlling human corneal epithelial (HCE) cell proliferation and wound healing. Epidermal growth factor (EGF) could stimulate cell proliferation and migration in various cell types. Therefore, we investigated the roles and mechanisms of EGF on HCE cell proliferation and migration. CCK-8 kit and wound healing experiment were used to investigate HCE cell proliferation and cell migration, respectively. ROS activity was quantified by DCFDA and flow cytometry. Western blot and Q-PCR were performed to examine protein and RNA levels. EGF could promote HCE cell proliferation and migration in both physiology status and UV irradiation conditions, which is used to mimic the disease condition in human corneal epithelial cells. Interestingly, the promotion effect of EGF on HCE cell proliferation is mainly mediated by activated ROS signaling under disease condition. However, the EGF function is mediated by ROS and MAPK/ERK pathway in EGF-treated corneal epithelial cells in physiology status, in which ROS and MAPK/ERK pathway have no mutual influence on the other signaling pathway in EGF-stimulated corneal epithelial cells. We also revealed that MAPK/ERK pathway instead of ROS mediates EGF-stimulated HCE cell migration. Interestingly, we found that PKC proteins were downregulated by EGF in HCE cells that is partially mediated by ROS signaling, while PKC pathway was not involved in EGF-stimulated corneal cell proliferation and migration. EGF promotes human corneal cell proliferation and migration both in physiology and disease conditions, and ROS, MAPK/ERK and PKC pathways play different roles in these processes.

  6. Latent transforming growth factor β-binding protein-3 and fibulin-1C interact with the extracellular domain of the heparin-binding EGF-like growth factor precursor

    Directory of Open Access Journals (Sweden)

    Eidels Leon

    2002-01-01

    Full Text Available Abstract Background The membrane-bound cell-surface precursor and soluble forms of heparin-binding epidermal growth factor-like growth factor (HB-EGF contribute to many cellular developmental processes. The widespread occurrence of HB-EGF in cell and tissue types has led to observations of its role in such cellular and tissue events as tumor formation, cell migration, extracellular matrix formation, wound healing, and cell adherence. Several studies have reported the involvement of such extracellular matrix proteins as latent transforming growth factor β-binding protein, TGF-β, and fibulin-1 in some of these processes. To determine whether HB-EGF interacts with extracellular matrix proteins we used the extracellular domain of proHB-EGF in a yeast two-hybrid system to screen a monkey kidney cDNA library. cDNA clones containing nucleotide sequences encoding domains of two proteins were obtained and their derived amino acid sequences were evaluated. Results From ≈ 3 × 106 screened monkey cDNA clones, cDNA clones were recovered that contained nucleotide sequences encoding domains of the monkey latent transforming growth factor-β binding protein-3 (MkLTBP-3 and fibulin-1C protein. The amino acid sequence derived from the MkLTBP-3 gene shared 98.6% identity with human LTBP-3 and 86.7% identity with mouse LTBP-3 amino acid sequences. The amino acid sequence derived from the monkey fibulin-1C gene shared 97.2% identity with human fibulin-1C. Yeast two-hybrid screens indicate that LTBP-3 and fibulin-1C interact with proHB-EGF through their calcium-binding EGF-like modules. Conclusions The interactions of the extracellular domain of proHB-EGF with LTBP-3 and fibulin-1C suggest novel functions for HB-EGF between cell and tissue surfaces.

  7. The EGF repeat-specific O-GlcNAc-transferase Eogt interacts with notch signaling and pyrimidine metabolism pathways in Drosophila.

    Directory of Open Access Journals (Sweden)

    Reto Müller

    Full Text Available The O-GlcNAc transferase Eogt modifies EGF repeats in proteins that transit the secretory pathway, including Dumpy and Notch. In this paper, we show that the Notch ligands Delta and Serrate are also substrates of Eogt, that mutation of a putative UDP-GlcNAc binding DXD motif greatly reduces enzyme activity, and that Eogt and the cytoplasmic O-GlcNAc transferase Ogt have distinct substrates in Drosophila larvae. Loss of Eogt is larval lethal and disrupts Dumpy functions, but does not obviously perturb Notch signaling. To identify novel genetic interactions with eogt, we investigated dominant modification of wing blister formation caused by knock-down of eogt. Unexpectedly, heterozygosity for several members of the canonical Notch signaling pathway suppressed wing blister formation. And importantly, extensive genetic interactions with mutants in pyrimidine metabolism were identified. Removal of pyrimidine synthesis alleles suppressed wing blister formation, while removal of uracil catabolism alleles was synthetic lethal with eogt knock-down. Therefore, Eogt may regulate protein functions by O-GlcNAc modification of their EGF repeats, and cellular metabolism by affecting pyrimidine synthesis and catabolism. We propose that eogt knock-down in the wing leads to metabolic and signaling perturbations that increase cytosolic uracil levels, thereby causing wing blister formation.

  8. Genetic variations in EGF and EGFR and glioblastoma outcome

    DEFF Research Database (Denmark)

    Sjöström, Sara; Andersson, Ulrika; Liu, Yanhong

    2010-01-01

    Few prognostic factors have been associated with glioblastoma survival. We analyzed a complete tagging of the epidermal growth factor (EGF) and EGF receptor (EGFR) gene polymorphisms as potential prognostic factors. Thirty tagging single-nucleotide polymorphisms (SNPs) in EGF and 89 tagging SNPs ...

  9. TACC3 is essential for EGF-mediated EMT in cervical cancer.

    Directory of Open Access Journals (Sweden)

    Geun-Hyoung Ha

    Full Text Available The third member of transforming acidic coiled-coil protein (TACC family, TACC3, has been shown to be an important player in the regulation of centrosome/microtubule dynamics during mitosis and found to be deregulated in a variety of human malignancies. Our previous studies have suggested that TACC3 may be involved in cervical cancer progression and chemoresistance, and its overexpression can induce epithelial-mesenchymal transition (EMT by activating the phosphatidylinositol 3-kinase (PI3K/Akt and extracellular signal-regulated protein kinases (ERKs signal transduction pathways. However, the upstream mechanisms of TACC3-mediated EMT and its functional/clinical importance in human cervical cancer remain elusive. Epidermal growth factor (EGF has been shown to be a potent inducer of EMT in cervical cancer and associated with tumor invasion and metastasis. In this study, we found that TACC3 is overexpressed in cervical cancer and can be induced upon EGF stimulation. The induction of TACC3 by EGF is dependent on the tyrosine kinase activity of the EGF receptor (EGFR. Intriguingly, depletion of TACC3 abolishes EGF-mediated EMT, suggesting that TACC3 is required for EGF/EGFR-driven EMT process. Moreover, Snail, a key player in EGF-mediated EMT, is found to be correlated with the expression of TACC3 in cervical cancer. Collectively, our study highlights a novel function for TACC3 in EGF-mediated EMT process and suggests that targeting of TACC3 may be an attractive strategy to treat cervical cancers driven by EGF/EGFR signaling pathways.

  10. Involvement of aquaporin-3 in epidermal growth factor receptor signaling via hydrogen peroxide transport in cancer cells.

    Science.gov (United States)

    Hara-Chikuma, Mariko; Watanabe, Sachiko; Satooka, Hiroki

    2016-03-18

    Aquaporin 3 (AQP3), a water/glycerol channel protein, is capable of transporting hydrogen peroxide (H2O2). Here, we show that AQP3-mediated intracellular H2O2 is involved in epidermal growth factor (EGF)-induced cell signaling and its dependent cell function in the EGF receptor (EGFR)-positive cancer cell lines A431 and H1666. AQP3 knockdown suppressed the transport into the cells of extracellular H2O2 produced in response to EGF in A431 and H1666 cells. EGF-induced Erk and Akt activation, which occurred through SHP2 and/or PTEN modulation, was impaired by AQP3 knockdown. Cell growth and migration induced by EGF stimulation were attenuated in AQP3 knockdown cells compared with those in control cells. Coincidentally, tumor growth of A431 cell xenografts in immunodeficient mice was decreased by AQP3 knockdown. Accordingly, a xenograft with AQP3 knockdown A431 cells significantly enhanced the survival of recipient mice compared with the transplantation with control cells. In addition, AQP3 associated with EGFR and NADPH oxidase 2, which we propose is linked to AQP3 producing a localized increase in intracellular H2O2 to function as a second messenger during EGFR cell signaling. Therefore, our findings suggest that AQP3 is required for EGF-EGFR cell signaling in cancer cells and is a therapeutic target for cancer progression.

  11. Neuropathologic Implication of Peripheral Neuregulin-1 and EGF Signals in Dopaminergic Dysfunction and Behavioral Deficits Relevant to Schizophrenia: Their Target Cells and Time Window

    Directory of Open Access Journals (Sweden)

    Hiroyuki Nawa

    2014-01-01

    Full Text Available Neuregulin-1 and epidermal growth factor (EGF are implicated in the pathogenesis of schizophrenia. To test the developmental hypothesis for schizophrenia, we administered these factors to rodent pups, juveniles, and adults and characterized neurobiological and behavioral consequences. These factors were also provided from their transgenes or infused into the adult brain. Here we summarize previous results from these experiments and discuss those from neuropathological aspects. In the neonatal stage but not the juvenile and adult stages, subcutaneously injected factors penetrated the blood-brain barrier and acted on brain neurons, which later resulted in persistent behavioral and dopaminergic impairments associated with schizophrenia. Neonatally EGF-treated animals exhibited persistent hyperdopaminergic abnormalities in the nigro-pallido-striatal system while neuregulin-1 treatment resulted in dopaminergic deficits in the corticolimbic dopamine system. Effects on GABAergic and glutamatergic systems were transient or limited. Even in the adult stage, intracerebral administration and transgenic expression of these factors produced similar but not identical behavioral impairments, although the effects of intracerebral administration were reversible. These findings suggest that dopaminergic development is highly vulnerable to circulating ErbB ligands in the pre- and perinatal stages. Once maldevelopment of the dopaminergic system is established during early development, dopamine-associating behavioral deficits become irreversible and manifest at postpubertal stages.

  12. Infiltration anesthetic lidocaine inhibits cancer cell invasion by modulating ectodomain shedding of heparin-binding epidermal growth factor-like growth factor (HB-EGF).

    Science.gov (United States)

    Mammoto, Tadanori; Higashiyama, Shigeki; Mukai, Mutsuko; Mammoto, Akiko; Ayaki, Masako; Mashimo, Takashi; Hayashi, Yukio; Kishi, Yoshihiko; Nakamura, Hiroyuki; Akedo, Hitoshi

    2002-09-01

    Although the mechanism is unknown, infiltration anesthetics are believed to have membrane-stabilizing action. We report here that such a most commonly used anesthetic, lidocaine, effectively inhibited the invasive ability of human cancer (HT1080, HOS, and RPMI-7951) cells at concentrations used in surgical operations (5-20 mM). Ectodomain shedding of heparin-binding epidermal growth factor-like growth factor (HB-EGF) from the cell surface plays an important role in invasion by HT1080 cells. Lidocaine reduced the invasion ability of these cells by partly inhibiting the shedding of HB-EGF from the cell surface and modulation of intracellular Ca2+ concentration contributed to this action. The anesthetic action of lidocaine (sodium channel blocking ability) did not contribute to this anti-invasive action. In addition, lidocaine (5-30 mM), infiltrated around the inoculation site, inhibited pulmonary metastases of murine osteosarcoma (LM 8) cells in vivo. These data point to previously unrecognized beneficial actions of lidocaine and suggest that lidocaine might be an ideal infiltration anesthetic for surgical cancer operations.

  13. Royalactin extends lifespan of Caenorhabditis elegans through epidermal growth factor signaling.

    Science.gov (United States)

    Detienne, Giel; De Haes, Wouter; Ernst, Ulrich R; Schoofs, Liliane; Temmerman, Liesbet

    2014-12-01

    Royalactin is a glycoprotein essential for the development of long-lived queen honeybees. Only larvae fed with royal jelly, containing royalactin, develop into queens. Royalactin plays a central role in this process by switching on the epidermal growth factor (EGF) receptor signaling pathway which ultimately leads to epigenetic changes and a long-lived queen phenotype. Recently it was shown that royalactin by itself also extends lifespan in Drosophila melanogaster. Yet, the mechanism by which royalactin promotes longevity remains largely unknown. We set out to characterize the effects of royalactin on Caenorhabditis elegans lifespan, and clarify the possible involvement of EGF signaling in this process. We demonstrate that royalactin extends lifespan of this nematode and that both EGF (LIN-3) and its receptor (LET-23) are essential to this process. To our knowledge, this is the first report of royalactin-mediated lifespan extension in a non-insect species. Additionally, we show that royalactin enhances locomotion in adult nematodes, implying that royalactin also influences healthspan. Our results suggest that royalactin is an important lifespan-extending factor in royal jelly and acts by promoting EGF signaling in C. elegans. Further work will now be needed to clarify which (secondary) signaling pathways are activated by royalactin, and how this ultimately translates into an extended health- and lifespan.

  14. Epidermal growth factor (EGF) fragment-guided anticancer theranostic particles for pH-responsive release of doxorubicin.

    Science.gov (United States)

    Kang, Myun Koo; Mao, Wei; Lee, Jun Bae; Yoo, Hyuk Sang

    2017-03-15

    EGF fragment (EGFfr) and doxorubicin were chemically co-decorated on single magnetic nanoparticles (MNPs) for concomitant cancer targeting and treatment. Magnetic nanoparticles were prepared by the precipitation of ferric chloride hydrates in an ammonia solution and subsequent surface-functionalization with amines. The terminal thiol group of the EGF fragment was first conjugated to surface amines of the MNPs using a heterofunctional crosslinker, and doxorubicin was sequentially conjugated to the MNPs via a hydrazone linker, where the degree of subsitution of the surface amines to EGFfr was varied from 1% to 40%. The decorated doxorubicin showed clear pH-dependency in the release profile, and doxorubicin showed fast release at pH 5.0 in comparison to pH 7.4. The EGF-decorated MNPs were tested for differential cellular uptakes against EGF overexpressing cells (A549), and the uptake levels gradually increased to 10% and saturated, which was quantified by ICP-OES. Internalized doxorubicin was also visualized by confocal microscopy, and A549 cells with EGF-decorated MNPs with EGF decoration showed higher fluorescence intensity of doxorubicin than those with non-decorated MNPs. Anti-cancer activity of the MNPs was compared at various concentrations of doxorubicin and EGFfr. Decoration of EGFfr significantly increased the anti-cancer activity of doxorubicin-incorporated MNPs in A549 cells; however, EGFfr alone did not affect the viability of the cells. Thus, we concluded that MNPs with optimized EGFfr and doxorubicin ratios showed higher targeting and drug payload against EGF receptor overexpressing cancer cells. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Role of the EGF-Related Growth Factor cripto in Murine Mammary Tumorigenesis

    Science.gov (United States)

    2000-10-01

    b, The urogenital region of a, wild-type and b, mutant neonates. system""𔄃 . Here we show that male mice lacking the signalling k, kidney: o, ovary...left lung; (Iv) left ventricle; (ml) medial lobe; (pa) pulmonary artery; (ra) right atrium; (rv) right ventricle; (sp) spleen; (st) stomach; ( tb

  16. Time-dependent changes of levels of endogenous epidermal growth factor in submandibular glands, in kidneys, and in urine in rats during systemic treatment with EGF

    DEFF Research Database (Denmark)

    Vinter-Jensen, Lars; Jørgensen, P E; Thulesen, J

    1998-01-01

    Exogenous EGF influences the levels of endogenous EGF differently in the submandibular glands (SMG) and the kidneys. The aim of the present study was to examine the time-dependent changes in levels of endogenous EGF during 1-4 weeks of EGF treatment....

  17. Regulation of EGF-induced ERK/MAPK Activation and EGFR Internalization by G Protein-coupled Receptor Kinase 2

    Institute of Scientific and Technical Information of China (English)

    Jingxia GAO; Jiali LI; Lan MA

    2005-01-01

    G protein-coupled receptor kinases (GRKs) mediate agonist-induced phosphorylation and desensitization of various G protein-coupled receptors (GPCRs). We investigate the role of GRK2 on epidermal growth factor (EGF) receptor signaling, including EGF-induced extracellular signal-regulated kinase and mitogen-activated protein kinase (ERK/MAPK) activation and EGFR internalization. Immunoprecipitation and immunofluorescence experiments show that EGF stimulates GRK2 binding to EGFR complex and GRK2 translocating from cytoplasm to the plasma membrane in human embryonic kidney 293 cells. Western blotting assay shows that EGF-induced ERK/MAPK phosphorylation increases 1.9-fold, 1.1-fold and 1.5-fold (P<0.05) at time point 30, 60 and 120 min, respectively when the cells were transfected with GRK2,suggesting the regulatory role of GRK2 on EGF-induced ERK/MAPK activation. Flow cytometry experiments show that GRK2 overexpression has no effect on EGF-induced EGFR internalization, however, it increases agonist-induced G protein-coupled δ opioid receptor internalization by approximately 40% (P<0.01). Overall,these data suggest that GRK2 has a regulatory role in EGF-induced ERK/MAPK activation, and that the mechanisms underlying the modulatory role of GRK2 in EGFR and GPCR signaling pathways are somewhat different at least in receptor internalization.

  18. Diacylglycerol kinase counteracts protein kinase C-mediated inactivation of the EGF receptor

    NARCIS (Netherlands)

    Baal, van J.; Widt, de J.; Divecha, N.; Blitterswijk, van W.J.

    2012-01-01

    Epidermal growth factor receptor (EGFR) activation is negatively regulated by protein kinase C (PKC)signaling. Stimulation of A431 cells with EGF, bradykinin or UTP increased EGFR phosphorylation at Thr654 in a PKC-dependent manner. Inhibition of PKC signaling enhanced EGFR activation, as assessed b

  19. 5-Fluorocytosine combined with Fcy-hEGF fusion protein targets EGFR-expressing cancer cells

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-11-16

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

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

    Science.gov (United States)

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

    2014-01-01

    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 transected with NMB receptors. The transactivation of the EGF receptor or the tyrosine phosphorylation of ERK caused by NMB-like peptides was inhibited by AG1478 or gefitinib (tyrosine kinase inhibitors) and NMB receptor antagonist PD168368 but not the GRP receptor antagonist, BW2258U89. The transactivation of the EGF receptor caused by NMB-like peptides was inhibited by GM6001 (matrix metalloprotease inhibitor), PP2 (Src inhibitor), or transforming growth factor (TGF)α antibody. The transactivation of the EGF receptor and the increase in reactive oxygen species caused by NMB-like peptides was inhibited by N-acetylcysteine (NAC) or Tiron. Gefitinib inhibited the proliferation of NCI-H1299 cells and its sensitivity was increased by the addition of PD168368. The results indicate that the NMB receptor regulates EGF receptor transactivation by a mechanism dependent on Src as well as metalloprotease activation and generation of reactive oxygen species. PMID:20388507

  1. ROLES OF EPIDERMAL GROWTH FACTOR (EGF) AND TRANSFORMING GROWTH FACTOR-ALPHA (TGF-A) IN MEDIATION OF DIOXIN (TCDD)-INDUCED DELAYS IN DEVELOPMENT OF THE MOUSE MAMMARY GLAND

    Science.gov (United States)

    Roles of Epidermal Growth Factor (EGF) and Transforming Growth Factor-alpha (TGF-a) in Mediation of Dioxin (TCDD)-Induced Delays in Development of the Mouse Mammary Gland.Suzanne E. Fenton, Barbara Abbott, Lamont Bryant, and Angela Buckalew. U.S. EPA, NHEERL, Reproductive Tox...

  2. Restoration of Circulating MFGE8 (Milk Fat Globule-EGF Factor 8) Attenuates Cardiac Hypertrophy Through Inhibition of Akt Pathway.

    Science.gov (United States)

    Deng, Ke-Qiong; Li, Jing; She, Zhi-Gang; Gong, Jun; Cheng, Wen-Lin; Gong, Fu-Han; Zhu, Xue-Yong; Zhang, Yan; Wang, Zhihua; Li, Hongliang

    2017-10-01

    Cardiac hypertrophy occurs in response to numerous stimuli like neurohumoral stress, pressure overload, infection, and injury, and leads to heart failure. Mfge8 (milk fat globule-EGF factor 8) is a secreted protein involved in various human diseases, but its regulation and function during cardiac hypertrophy remain unexplored. Here, we found that circulating MFGE8 levels declined significantly in failing hearts from patients with dilated cardiomyopathy. Correlation analyses revealed that circulating MFGE8 levels were negatively correlated with the severity of cardiac dysfunction and remodeling in affected patients. Deleting Mfge8 in mice maintained normal heart function at basal level but substantially exacerbated the hypertrophic enlargement of cardiomyocytes, reprogramming of pathological genes, contractile dysfunction, and myocardial fibrosis after aortic banding surgery. In contrast, cardiac-specific Mfge8 overexpression in transgenic mice significantly blunted aortic banding-induced cardiac hypertrophy. Whereas MAPK (mitogen-activated protein kinase) pathways were unaffected in either Mfge8-knockout or Mfge8-overexpressing mice, the activated Akt/PKB (protein kinase B)-Gsk-3β (glycogen synthase kinase-3β)/mTOR (mammalian target of rapamycin) pathway after aortic banding was significantly potentiated by Mfge8 deficiency but suppressed by Mfge8 overexpression. Inhibition of Akt with MK-2206 blocked the prohypertrophic effects of Mfge8 deficiency in angiotensin II-treated neonatal rat cardiomyocytes. Finally, administering a recombinant human MFGE8 in mice in vivo alleviated cardiac hypertrophy induced by aortic banding. Our findings indicate that Mfge8 is an endogenous negative regulator of pathological cardiac hypertrophy and may, thus, have potential both as a novel biomarker and as a therapeutic target for treatment of cardiac hypertrophy. © 2017 American Heart Association, Inc.

  3. Transmembrane signalling at the epidermal growth factor receptor. Positive regulation by the C-terminal phosphotyrosine residues

    DEFF Research Database (Denmark)

    Magni, M; Pandiella, A; Helin, K

    1991-01-01

    in the double and the triple mutants. In the latter mutant, expression of the EGF-receptor-activated lipolytic enzyme phospholipase C gamma was unchanged, whereas its tyrosine phosphorylation induced by the growth factor was lowered to approx. 25% of that in the controls. In all of the cell clones employed...... mutants), intermediate in the dual mutants and almost complete in the triple mutants. Likewise, increases in intracellular Ca2+ concentrations [( Ca2+]i) induced by fibroblast growth factor were approximately the same in all of the clones, whereas those induced by EGF were decreased in the mutants, again...... a positive role in the regulation of transmembrane signalling at the EGF receptor. The stepwise decrease in signal generation observed in single, double and triple point mutants suggest that the role of phosphotyrosine residues is not in the participation in specific amino acid sequences, but rather...

  4. Differences in human skin between the epidermal growth factor receptor distribution detected by EGF binding and monoclonal antibody recognition

    DEFF Research Database (Denmark)

    Green, M R; Couchman, J R

    1985-01-01

    , the eccrine sweat glands, capillary system, and the hair follicle outer root sheath, generally similar in pattern to that previously reported for full-thickness rat skin and human epidermis. The same areas also bound EGF-R1 but in addition the monoclonal antibody recognized a cone of melanin containing...

  5. Accumulation of human EGF in nectar of transformed plants of Nicotiana langsdorffii x N. sanderae and transfer to honey by bees.

    Science.gov (United States)

    Helsper, J P F G; Ruyter-Spira, C P; Kwakman, P H S; Bleeker, W K; Keizer, L C P; Bade, J B; Te Velde, A A; Zaat, S A J; Verbeek, M; Creemers-Molenaar, J

    2011-09-01

    Honey has been used successfully in wound healing for thousands of years. The peptide hormone human epidermal growth factor (hEGF) is also known to have a beneficial effect in various wound healing processes via mechanisms that differ from those for honey. In this study, we show that hEGF can be incorporated into honey via nectar. Plants of Nicotiana langsdorffii x N. sanderae were transformed with the gene for hEGF, equipped with a nectary-targeted promoter and a signal sequence for secretion to nectar. These plants accumulated hEGF in the nectar. The maximum hEGF concentration recorded with ELISA in these plants is 2.5 ng·ml⁻¹. There is a significant linear relationship (Pplants did not allow production of honey from their nectar, we used feeding solutions, spiked with synthetic hEGF, to study transfer of this peptide into honey through bee activity. Transfer of hEGF from a feeding solution to honey by bees occurred with retention of the hEGF concentration and the capacity to induce hEGF-receptor phosphorylation. These observations indicate that plants can function as a production platform for honey containing biologically active peptides, which may enhance wound healing and other biological processes.

  6. Developmental defects in zebrafish for classification of EGF pathway inhibitors

    Energy Technology Data Exchange (ETDEWEB)

    Pruvot, Benoist; Curé, Yoann; Djiotsa, Joachim; Voncken, Audrey; Muller, Marc, E-mail: m.muller@ulg.ac.be

    2014-01-15

    One of the major challenges when testing drug candidates targeted at a specific pathway in whole animals is the discrimination between specific effects and unwanted, off-target effects. Here we used the zebrafish to define several developmental defects caused by impairment of Egf signaling, a major pathway of interest in tumor biology. We inactivated Egf signaling by genetically blocking Egf expression or using specific inhibitors of the Egf receptor function. We show that the combined occurrence of defects in cartilage formation, disturbance of blood flow in the trunk and a decrease of myelin basic protein expression represent good indicators for impairment of Egf signaling. Finally, we present a classification of known tyrosine kinase inhibitors according to their specificity for the Egf pathway. In conclusion, we show that developmental indicators can help to discriminate between specific effects on the target pathway from off-target effects in molecularly targeted drug screening experiments in whole animal systems. - Highlights: • We analyze the functions of Egf signaling on zebrafish development. • Genetic blocking of Egf expression causes cartilage, myelin and circulatory defects. • Chemical inhibition of Egf receptor function causes similar defects. • Developmental defects can reveal the specificity of Egf pathway inhibitors.

  7. Tumor Targeting Using Anti–Epidermal Growth Factor Receptor (ior egf/r3 Immunoconjugate with a Tetraaza Macrocyclic Agent (DO3A-EA

    Directory of Open Access Journals (Sweden)

    Gauri Mishra

    2012-09-01

    Full Text Available Epidermal growth factor receptor (EGFR signaling inhibition represents a highly promising arena for the application of molecularly targeted cancer therapies. EGFR conjugated metal chelates have been proposed as potential imaging agents for cancers that overexpress EGFR receptors. Through improved understanding of EGFR biology in human cancers, there is anticipation that more tumor-selective therapy approaches with diminished collateral normal tissue toxicity can be advanced. We report here on the results with a thermodynamically stable chelate, 1,4,7-tris(carboxymethyl-10-(2-aminoethyl-1,4,7,10-tetraazacyclododecane (DO3A-EA and anti-EGFr (ior egf/r3 conjugate to develop immunospecifc imaging agent. Conjugation and labelling with anti-EGFr was performed using standard procedure and subjected to purification on size exclusion chromatography. The conjugated antibodies were labeled with a specific activity 20-30 mCi/mg of protein. Labeling efficiencies were measured by ascending paper chromatography on ITLC-SG strips. Radiolabeling of the immunoconjugate was found to be 98.5 ± 0.30%. 99mTc-DO3A-EA-EGFr conjugate was studied in athymic mice bearing U-87MG, MDA-MB-468 tumors following intravenous injection. Pharmacokinetic and biodistribution studies confirmed long circulation times (t1/2(fast= 45 min and t1/2(slow=4 hours 40 min and efficient accumulation in tumors. Biodistribution studies in athymic mice grafted with U-87MG human glioblastoma multiforme and Hela human cervical carcinoma tumors revealed significant localization of 99mTc-labeled antibodies conjugate in tumors and reduced accumulation in normal organs. This new chelating agent is promising for immunoscintigraphy since good tumour-to-normal organ contrast could be demonstrated. These properties can be exploited for immunospecifc contrast agents in nuclear medicine and SPECT imaging.

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

    Energy Technology Data Exchange (ETDEWEB)

    Backer, Joseph M.

    2009-07-12

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

  9. EGF-receptor and extracellular matrix changes in mouse pulmonary carcinogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Smith, G.J.; Morris, C.; Leigh, D.; Rhodes, G.C.; Wong, A. (Carcinogenesis Research Unit, School of Pathology, University of New South Wales, Kensington (Australia))

    1991-03-01

    Malignant Balb/c mouse lung cell clones related to alveologenic carcinoma exhibited low levels of epidermal growth factor (EGF) receptor activity compared to nonmalignant cell clones. Immunoprecipitation of cell homogenates and immunohistochemistry on urethane-induced lung tumors suggest that the absence of activity reflects decreased amounts of EGF receptor protein. Low levels of EGF receptor alone cannot cause neoplastic transformation, since a nonneoplastic cell cone, B5D3, exhibited low levels of EGF receptor despite its nontransformed phenotype. The reduced levels of EGF receptor in malignant clones have been mimicked by long-term (12 h) treatment of a nontransformed cell clone with 200 nM phorbol dibutyrate. The detection of mutated ras oncogene in the transformed cell lines, taken together with the EGF receptor findings, suggests that more than one alteration in the signal transduction pathway may be necessary for transformation in alveologenic adenoma and carcinoma cell systems. A further phenotypic feature of transformation, reduced expression of the extracellular matrix proteins fibronectin and laminin, may be mediated at the transcriptional level.

  10. Comparison of solcoseryl and epidermal growth factors (EGF) in healing of chronic gastroduodenal ulcerations and mucosal growth in rats.

    Science.gov (United States)

    Konturek, S J; Brzozowski, T; Dembinski, A; Warzecha, A; Drozdowicz, D

    1988-02-01

    Solcoseryl, a deproteinized extract of calf blood, and EGF, produced by salivary glands, have been shown to enhance the healing of peptic ulcerations, but the mechanism of this effect is unknown. Since both solcoseryl and EGF have been reported to stimulate cell proliferation, we designed the study to compare the ulcer healing and growth promoting actions of these two agents in the same animals. Gastric and duodenal ulcerations were produced by serosal application of 100% acetic acid on an area of 13.8 mm2 of gastric and duodenal wall, respectively. In the control animals, 7 days after ulcer induction, the mean ulcer area was reduced to 7.1 +/- 1.2 mm2 in the stomach, and to 6.1 +/- 0.8 mm2 in the duodenum. After 14 days all ulcers were healed, both in the stomach and duodenum. Oral administration of solcoseryl (10 ml/kg-day) or EGF (30 micrograms/kg-day) for 7 days after ulcer induction resulted in a significant reduction in the ulcer area in the stomach, and to a greater extent in the duodenum. This enhancement of ulcer healing by solcoseryl was accompanied by a significant increase in the weight of the duodenal mucosa and the total contents of DNA and RNA after 7 days of treatment, and in the weight and nucleic acid contents in both the gastric and duodenal mucosa after 14 days of treatment. EGF also increased the weights and the nucleic acid contents in gastric and duodenal mucosa, but this was significant only after 14 days of treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

  11. Association of EGF Receptor and NLRs signaling with Cardiac Inflammation and Fibrosis in Mice Exposed to Fine Particulate Matter.

    Science.gov (United States)

    Jin, Yuefei; Wu, Zhaoke; Wang, Na; Duan, Shuyin; Wu, Yongjun; Wang, Jing; Wu, Weidong; Feng, Feifei

    2016-09-01

    ЄAmbient fine particulate matter (PM2.5 ) could induce cardiovascular diseases (CVD), but the mechanism remains unknown. To investigate the roles of epidermal growth factor receptor (EGFR) and NOD-like receptors (NLRs) in PM2.5 -induced cardiac injury, we set up a BALB/c mice model of PM2.5 -induced cardiac inflammation and fibrosis with intratracheal instillation of PM2.5 suspension (4.0 mg/kg b.w.) for 5 consecutive days (once per day). After exposure, we found that mRNA levels of CXCL1, interleukin (IL)-6, and IL-18 were elevated, but interestingly, mRNA level of NLRP12 was significant decreased in heart tissue from PM2.5 -induced mice compared with those of saline-treated mice using real-time PCR. Protein levels of phospho-EGFR (Tyr1068), phospho-Akt (Thr308), NLRP3, NF-κB-p52/p100, and NF-κB-p65 in heart tissue of PM2.5 -exposed mice were all significantly increased using immunohistochemistry or Western blotting. Therefore, PM2.5 exposure could induce cardiac inflammatory injury in mice, which may be involved with EGFR/Akt signaling, NLRP3, and NLRP12.

  12. Amplification, enhanced expression and possible rearrangement of EGF receptor gene in primary human brain tumours of glial origin.

    Science.gov (United States)

    Libermann, T A; Nusbaum, H R; Razon, N; Kris, R; Lax, I; Soreq, H; Whittle, N; Waterfield, M D; Ullrich, A; Schlessinger, J

    Epidermal growth factor (EGF), through interaction with specific cell surface receptors, generates a pleiotropic response that, by a poorly defined mechanism, can induce proliferation of target cells. Subversion of the EGF mitogenic signal through expression of a truncated receptor may be involved in transformation by the avian erythroblastosis virus (AEV) oncogene v-erb-B, suggesting that similar EGF receptor defects may be found in human neoplasias. Overexpression of EGF receptors has been reported on the epidermoid carcinoma cell line A431, in various primary brain tumours and in squamous carcinomas. In A431 cells the receptor gene is amplified. Here we show that 4 of 10 primary brain tumours of glial origin which express levels of EGF receptors that are higher than normal also have amplified EGF receptor genes. Amplified receptor genes were not detected in the other brain tumours examined. Further analysis of EGF receptor defects may show that such altered expression and amplification is a particular feature of certain human tumours.

  13. Specific N-glycan alterations are coupled in epithelial-mesenchymal transition induced by EGF in GE11 epithelial cells.

    Science.gov (United States)

    Xu, Qingsong; Qu, Chen; Wang, Wenjing; Gu, Jianguo; Du, Yuguang; Song, Linsheng

    2017-02-01

    Epithelial-mesenchymal transition (EMT) is a phenomenon in cancer progression during which cancer cells undergo remarkable alteration acquiring highly invasive property. The aim of this study was to evaluate specific N-glycan alterations during EMT induced by epidermal growth factor (EGF) in GE11 epithelial cells. Herein, we demonstrated that EGF activated epidermal growth factor receptor (EGFR)/Akt/extracellular signal-regulated kinase (ERK) phosphorylation and promoted GE11 cell proliferation. Meanwhile, EGF stimulated the epithelial cells to undergo morphological alteration, destroying cell-cell inter-contact and exhibiting mesenchymal cells higher metastatic potential. A wound-healing assay showed the migratory ability increased 1.5-fold after EGF treatment. Moreover, the relative intensity of N-cadherin versus E-cadherin increased 2.6-fold, and the E-cadherin distribution in cell-cell junctions became jagged and faint after EGF incubation for 72 h. Interestingly, the amounts of bisecting GlcNAc structure were dramatically declined, by contrast, the formation of β1,6 GlcNAc branches on cell surface was upregulated during EMT induced by EGF. To understand the roles of N-glycans in EGF-induced EMT, the cells were stably transfected with N-acetylglucosaminyltransferase III (GnT-III), which catalyzes the bisecting GlcNAc structure formation. As the markers for EMT, EGF-induced E-cadherin decrease and fibronectin increase were delayed in GnT-III-overexpressing cells. Taken together, these results demonstrated that specific N-glycan alterations were coupled in EMT induced by EGF, which might be contributed to diagnosis and therapy of tumor metastasis.

  14. An ultrasensitive sorting mechanism for EGF Receptor Endocytosis

    Directory of Open Access Journals (Sweden)

    Dikic Ivan

    2008-04-01

    Full Text Available Abstract Background The Epidermal Growth Factor (EGF receptor has been shown to internalize via clathrin-independent endocytosis (CIE in a ligand concentration dependent manner. From a modeling point of view, this resembles an ultrasensitive response, which is the ability of signaling networks to suppress a response for low input values and to increase to a pre-defined level for inputs exceeding a certain threshold. Several mechanisms to generate this behaviour have been described theoretically, the underlying assumptions of which, however, have not been experimentally demonstrated for the EGF receptor internalization network. Results Here, we present a mathematical model of receptor sorting into alternative pathways that explains the EGF-concentration dependent response of CIE. The described mechanism involves a saturation effect of the dominant clathrin-dependent endocytosis pathway and implies distinct steady-states into which the system is forced for low vs high EGF stimulations. The model is minimal since no experimentally unjustified reactions or parameter assumptions are imposed. We demonstrate the robustness of the sorting effect for large parameter variations and give an analytic derivation for alternative steady-states that are reached. Further, we describe extensibility of the model to more than two pathways which might play a role in contexts other than receptor internalization. Conclusion Our main result is that a scenario where different endocytosis routes consume the same form of receptor corroborates the observation of a clear-cut, stimulus dependent sorting. This is especially important since a receptor modification discriminating between the pathways has not been found experimentally. The model is not restricted to EGF receptor internalization and might account for ultrasensitivity in other cellular contexts.

  15. EGF Prevents the Neuroendocrine Differentiation of LNCaP Cells Induced By Serum Deprivation: The Modulator Role of P13K/Akt

    Directory of Open Access Journals (Sweden)

    Rosa M. Martín-Orozco

    2007-08-01

    Full Text Available The primary focus of this investigation was to study the relationship between neuroendocrine (NE differentiation, epidermal growth factor (EGF because both have been implicated in the progression of prostate cancer. For this purpose, we used gefitinib, trastuzumab, which are inhibitors of EGF receptor (EGFR, ErbB2, respectively. EGF prevents NE differentiation induced by androgen depletion. This effect is prevented by gefitinib, which blocks the activation of EGFR, ErbB2, stimulation of mitogen-activated protein kinase (MAPK, cell proliferation induced by EGF. Conversely, trastuzumab does not inhibit the effect of EGF on EGFR phosphorylation, MAPK activity, cell proliferation, NE differentiation, although it reduces ErbB2 levels specifically, suggesting that ErbB2 is not necessary to inhibit NE differentiation. Prevention of NE differentiation by EGF is mediated by a MAPK-dependent mechanism, requires constitutive Akt activation. The abrogation of the PI3K/Akt pathway changes the role of EGF from inhibitor to inductor of NE differentiation. We show that EGFR tyrosine kinase, MAPK, PI3K inhibitors inhibit the cell proliferation stimulated by EGF but induce the acquisition of NE phenotype. Altogether, the present data should be borne in mind when designing new clinical schedules for the treatment of prostate cancer, including the use of ErbB receptors, associated signaling pathway inhibitors.

  16. 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

  17. EGF receptor ligands: recent advances [version 1; referees: 3 approved

    Directory of Open Access Journals (Sweden)

    Bhuminder Singh

    2016-09-01

    Full Text Available Seven ligands bind to and activate the mammalian epidermal growth factor (EGF receptor (EGFR/ERBB1/HER1: EGF, transforming growth factor-alpha (TGFA, heparin-binding EGF-like growth factor (HBEGF, betacellulin (BTC, amphiregulin (AREG, epiregulin (EREG, and epigen (EPGN. Of these, EGF, TGFA, HBEGF, and BTC are thought to be high-affinity ligands, whereas AREG, EREG, and EPGN constitute low-affinity ligands. This focused review is meant to highlight recent studies related to actions of the individual EGFR ligands, the interesting biology that has been uncovered, and relevant advances related to ligand interactions with the EGFR.

  18. The statistical mechanics of complex signaling networks: nerve growth factor signaling.

    Science.gov (United States)

    Brown, K S; Hill, C C; Calero, G A; Myers, C R; Lee, K H; Sethna, J P; Cerione, R A

    2004-12-01

    The inherent complexity of cellular signaling networks and their importance to a wide range of cellular functions necessitates the development of modeling methods that can be applied toward making predictions and highlighting the appropriate experiments to test our understanding of how these systems are designed and function. We use methods of statistical mechanics to extract useful predictions for complex cellular signaling networks. A key difficulty with signaling models is that, while significant effort is being made to experimentally measure the rate constants for individual steps in these networks, many of the parameters required to describe their behavior remain unknown or at best represent estimates. To establish the usefulness of our approach, we have applied our methods toward modeling the nerve growth factor (NGF)-induced differentiation of neuronal cells. In particular, we study the actions of NGF and mitogenic epidermal growth factor (EGF) in rat pheochromocytoma (PC12) cells. Through a network of intermediate signaling proteins, each of these growth factors stimulates extracellular regulated kinase (Erk) phosphorylation with distinct dynamical profiles. Using our modeling approach, we are able to predict the influence of specific signaling modules in determining the integrated cellular response to the two growth factors. Our methods also raise some interesting insights into the design and possible evolution of cellular systems, highlighting an inherent property of these systems that we call 'sloppiness.'

  19. EGF and curcumin co-encapsulated nanoparticle/hydrogel system as potent skin regeneration agent

    Directory of Open Access Journals (Sweden)

    Li X

    2016-08-01

    Full Text Available Xiaoling Li,1 Xianlong Ye,2 Jianying Qi,2 Rangrang Fan,1 Xiang Gao,1 Yunzhou Wu,2 Liangxue Zhou,1 Aiping Tong,1 Gang Guo1 1State Key Laboratory of Biotherapy and Cancer Center, Department of Neurosurgery, West China Hospital, Sichuan University and Collaborative Innovation Center for Biotherapy, Chengdu, People’s Republic of China; 2College of Life Science, Northeast Agriculture University, Harbin, People’s Republic of China Abstract: Wound healing is a complex multifactorial process that relies on coordinated signaling molecules to succeed. Epidermal growth factor (EGF is a mitogenic polypeptide that stimulates wound repair; however, precise control over its application is necessary to reduce the side effects and achieve desired therapeutic benefits. Moreover, the extensive oxidative stress during the wound healing process generally inhibits repair of the injured tissues. Topical applications of antioxidants like curcumin (Cur could protect tissues from oxidative damage and significantly improve tissue remodeling. To achieve much accelerated wound healing effects, we designed a novel dual drug co-loaded in situ gel-forming nanoparticle/hydrogel system (EGF-Cur-NP/H which acted not only as a supportive matrix for the regenerative tissue, but also as a sustained drug depot for EGF and Cur. In the established excisional full-thickness wound model, EGF-Cur-NP/H treatment significantly enhanced wound closure through increasing granulation tissue formation, collagen deposition, and angiogenesis, relative to normal saline, nanoparticle/hydrogel (NP/H, Cur-NP/H, and EGF-NP/H treated groups. In conclusion, this study provides a biocompatible in situ gel-forming system for efficient topical application of EGF and Cur in the landscape of tissue repair. Keywords: epidermal growth factor, EGF, curcumin, wound healing, thermosensitive hydrogel, nanoparticles 

  20. Epidermal Growth Factor Signaling towards Proliferation: Modeling and Logic Inference Using Forward and Backward Search.

    Science.gov (United States)

    Riesco, Adrián; Santos-Buitrago, Beatriz; De Las Rivas, Javier; Knapp, Merrill; Santos-García, Gustavo; Talcott, Carolyn

    2017-01-01

    In biological systems, pathways define complex interaction networks where multiple molecular elements are involved in a series of controlled reactions producing responses to specific biomolecular signals. These biosystems are dynamic and there is a need for mathematical and computational methods able to analyze the symbolic elements and the interactions between them and produce adequate readouts of such systems. In this work, we use rewriting logic to analyze the cellular signaling of epidermal growth factor (EGF) and its cell surface receptor (EGFR) in order to induce cellular proliferation. Signaling is initiated by binding the ligand protein EGF to the membrane-bound receptor EGFR so as to trigger a reactions path which have several linked elements through the cell from the membrane till the nucleus. We present two different types of search for analyzing the EGF/proliferation system with the help of Pathway Logic tool, which provides a knowledge-based development environment to carry out the modeling of the signaling. The first one is a standard (forward) search. The second one is a novel approach based on narrowing, which allows us to trace backwards the causes of a given final state. The analysis allows the identification of critical elements that have to be activated to provoke proliferation.

  1. PLC-gamma1 and Rac1 coregulate EGF-induced cytoskeleton remodeling and cell migration.

    Science.gov (United States)

    Li, Siwei; Wang, Qian; Wang, Yi; Chen, Xinmei; Wang, Zhixiang

    2009-06-01

    It is well established that epidermal growth factor (EGF) induces the cytoskeleton reorganization and cell migration through two major signaling cascades: phospholipase C-gamma1 (PLC-gamma1) and Rho GTPases. However, little is known about the cross talk between PLC-gamma1 and Rho GTPases. Here we showed that PLC-gamma1 forms a complex with Rac1 in response to EGF. This interaction is direct and mediated by PLC-gamma1 Src homology 3 (SH3) domain and Rac1 (106)PNTP(109) motif. This interaction is critical for EGF-induced Rac1 activation in vivo, and PLC-gamma1 SH3 domain is actually a potent and specific Rac1 guanine nucleotide exchange factor in vitro. We have also demonstrated that the interaction between PLC-gamma1 SH3 domain and Rac1 play a significant role in EGF-induced F-actin formation and cell migration. We conclude that PLC-gamma1 and Rac1 coregulate EGF-induced cell cytoskeleton remodeling and cell migration by a direct functional interaction.

  2. Multiple platform assessment of the EGF dependent transcriptome by microarray and deep tag sequencing analysis

    Directory of Open Access Journals (Sweden)

    Iraola Susana

    2011-06-01

    Full Text Available Abstract Background Epidermal Growth Factor (EGF is a key regulatory growth factor activating many processes relevant to normal development and disease, affecting cell proliferation and survival. Here we use a combined approach to study the EGF dependent transcriptome of HeLa cells by using multiple long oligonucleotide based microarray platforms (from Agilent, Operon, and Illumina in combination with digital gene expression profiling (DGE with the Illumina Genome Analyzer. Results By applying a procedure for cross-platform data meta-analysis based on RankProd and GlobalAncova tests, we establish a well validated gene set with transcript levels altered after EGF treatment. We use this robust gene list to build higher order networks of gene interaction by interconnecting associated networks, supporting and extending the important role of the EGF signaling pathway in cancer. In addition, we find an entirely new set of genes previously unrelated to the currently accepted EGF associated cellular functions. Conclusions We propose that the use of global genomic cross-validation derived from high content technologies (microarrays or deep sequencing can be used to generate more reliable datasets. This approach should help to improve the confidence of downstream in silico functional inference analyses based on high content data.

  3. Transforming growth factor-β1 induces EMT by the transactivation of epidermal growth factor signaling through HA/CD44 in lung and breast cancer cells.

    Science.gov (United States)

    Li, Lingmei; Qi, Lisha; Liang, Zhijie; Song, Wangzhao; Liu, Yanxue; Wang, Yalei; Sun, Baocun; Zhang, Bin; Cao, Wenfeng

    2015-07-01

    Epithelial-mesenchymal transition (EMT), a process closely related to tumor development, is regulated by a variety of signaling pathways and growth factors, such as transforming growth factor-β1 (TGF-β1) and epidermal growth factor (EGF). Hyaluronan (HA) has been shown to induce EMT through either TGF-β1 or EGF signaling and to be a regulator of the crosstalk between these two pathways in fibroblasts. In this study, in order to clarify whether HA has the same effect in tumor cells, we utilized the lung cancer cell line, A549, and the breast cancer cell line, MCF-7, and found that the effects of stimulation with TGF-β1 were more potent than those of EGF in regulating the expression of EMT-associated proteins and in enhancing cell migration and invasion. In addition, we observed that TGF-β1 activated EGF receptor (EGFR) and its downstream AKT and extracellular signal-regulated kinase (ERK) pathways. Furthermore, we found that TGF-β1 upregulated the expression of hyaluronan synthases (HAS1, HAS2 and HAS3) and promoted the expression of CD44, a cell surface receptor for HA, which interacts with EGFR, resulting in the activation of the downstream AKT and ERK pathways. Conversely, treatment with 4-methylumbelliferone (4-MU; an inhibitor of HAS) prior to stimulation with TGF-β1, inhibited the expression of CD44 and EGFR, abolished the interaction between CD44 and EGFR. Furthermore, the use of shRNA targeting CD44 impaired the expression of EGFR, deactivated the AKT and ERK pathways, reversed EMT and decreased the migration and invasion ability of cells. In conclusion, our data demonstrate that TGF-β1 induces EMT by the transactivation of EGF signaling through HA/CD44 in lung and breast cancer cells.

  4. An Integrated Model of Epidermal Growth Factor Receptor Trafficking and Signal Transduction

    Energy Technology Data Exchange (ETDEWEB)

    Resat, Haluk; Ewald, Jonathan A.; Dixon, David A.; Wiley, H. S.

    2003-08-01

    Endocytic trafficking of many types of receptors can have profound effects on subsequent signaling events. Quantitative models of these processes, however, have usually considered trafficking and signaling independently. Here, we present an integrated model of both the trafficking and signaling pathway of the epidermal growth factor receptor (EGFR) using a probability weighted-dynamic Monte Carlo simulation. Our model consists of hundreds of distinct endocytic compartments and about 13,000 reactions/events that occur over a broad spatio-temporal range. By using a realistic multi-compartment model, we can investigate the distribution of the receptors among cellular compartments as well as their potential signal transduction characteristics. Our new model also allows the incorporation of physio-chemical aspects of ligand-receptor interactions, such as pH-dependent binding in different endosomal compartments. To determine the utility of this approach, we simulated the differential activation of the EGFR by two of its ligands, epidermal growth factor (EGF) and transforming growth factor- alpha (TGF-a). Our simulations predict that when EGFR is activated with TGF-a, receptor activation is biased toward the cell surface whereas EGF produces a signaling bias towards the endosomal compartment. Experiments confirm these predictions from our model and simulations. Our model accurately predicts the kinetics and extent of receptor down-regulation induced by either EGF or TGF-a. Our results suggest that receptor trafficking controls the compartmental bias of signal transduction, rather than simply modulating signal magnitude. Our model provides a new approach to evaluating the complex effect of receptor trafficking on signal transduction. Importantly, the stochastic and compartmental nature of the simulation allows these models to be directly tested by high-throughput approaches, such as quantitative image analysis.

  5. A Phase III Clinical Trial of the Epidermal Growth Factor Vaccine CIMAvax-EGF as Switch Maintenance Therapy in Advanced Non-Small Cell Lung Cancer Patients.

    Science.gov (United States)

    Rodriguez, Pedro C; Popa, Xitllaly; Martínez, Odeth; Mendoza, Silvia; Santiesteban, Eduardo; Crespo, Tatiana; Amador, Rosa M; Fleytas, Ricardo; Acosta, Soraida C; Otero, Yanine; Romero, Gala N; de la Torre, Ana; Cala, Mireysi; Arzuaga, Lina; Vello, Loisel; Reyes, Delmairis; Futiel, Niurka; Sabates, Teresa; Catala, Mauricio; Flores, Yoanna I; Garcia, Beatriz; Viada, Carmen; Lorenzo-Luaces, Patricia; Marrero, Maria A; Alonso, Liuba; Parra, Jenelin; Aguilera, Nadia; Pomares, Yaisel; Sierra, Patricia; Rodríguez, Gryssell; Mazorra, Zaima; Lage, Agustin; Crombet, Tania; Neninger, Elia

    2016-08-01

    EGFR is a well-validated target for patients with non-small cell lung cancer (NSCLC). CIMAvax-EGF is a therapeutic cancer vaccine composed of human recombinant EGF conjugated to a carrier protein and Montanide ISA51 as adjuvant. The vaccine is intended to induce antibodies against self EGFs that block EGF-EGFR interaction. To evaluate overall survival, safety, immunogenicity, and EGF concentration in serum after CIMAvax-EGF, a randomized phase III trial was done in patients with advanced NSCLC. Four to 6 weeks after first-line chemotherapy, 405 patients with stage IIIB/IV NSCLC were randomly assigned to a vaccine group, which received CIMAvax-EGF or a control group, treated with best supportive care. Long-term vaccination was very safe. Most frequent adverse reactions were grade 1 or 2 injection-site pain, fever, vomiting, and headache. Vaccination induced anti-EGF antibodies and decreased serum EGF concentration. In the safety population, median survival time (MST) was 10.83 months in the vaccine arm versus 8.86 months in the control arm. These differences were not significant according the standard log rank (HR, 0.82; P = 0.100), but according a weighted log rank (P = 0.04) that was applied once the nonproportionality of the HR was verified. Survival benefit was significant (HR, 0.77; P = 0.036) in the per-protocol setting (patients receiving at least four vaccine doses): MST was 12.43 months for the vaccine arm versus 9.43 months for the control arm. MST was higher (14.66 months) for vaccinated patients with high EGF concentration at baseline. Switch maintenance with CIMAvax-EGF was well tolerated and significantly increased MST of patients that completed induction vaccination. Baseline EGF concentration predicted survival benefit. Clin Cancer Res; 22(15); 3782-90. ©2016 AACR. ©2016 American Association for Cancer Research.

  6. Correlation between epidermal growth factor (EGF61A/G)gene polymorphism andschizophrenia susceptibility:A Meta analysis%表皮生长因子(EGF61A/G)基因多态性与精神分裂症易感性关系的Meta分析

    Institute of Scientific and Technical Information of China (English)

    何大莉; 曾照芳

    2012-01-01

    目的:评价表皮生长因子(EGF61A/G)基因多态性与精神分裂症易感性的相关性。方法:全面检索PubMext、webofScience、Googl。Scholardatabase、维普、万方数据库,收集EGF61A/G基因多态性与精神分裂症相关性的文献。用Meta分析评价EGF61A/G各基因型(Avs.G、AAVS.GG、AAVS.GA+GG、AA+GAVS.GG)分布在精神分裂病组与对照组中是否有差异。结果:共纳入6篇文献,共有精神分裂症患者1038例,健康对照1190例。Meta分析未发现EGF61A/G基因多态性与精神分裂症具有相关性(Avs.G:OR=0.99,95%CI:0.871.12;AAvs.GG:OR=1.00,95%CI=0.77-1.29;AAVS.GA+GG:OR=0.89,95%CI=0.71—1.11;AA+AGvs.GG:OR=1.07,95%CI=0.0.89—1.28)。结论:本研究未鉴定出EGF61A/G基因多态性与和精神分裂症的相关性。%Objective: To evaluate the correlation between epidermal growth factor(EGF61A/G) gene polymoqohism and schizophrenia susceptibility. Methods: We searched PubMed, Web of Science, Google Scholar database, Weipu, Wanfang database and collected all the publications about the correlation between EGF61A/G polymorphism and schizophrenia susceptibility. Meta analysis was performed for assessing the difference of EGF61A/G genotype distribution (A vs. G,AA vs. GG, AA vs. GA + GG, AA + GA vs. GG)between two groups (schizophrenia group and control group)o Results:A total of 6 studies involving 1038 schizophrenia patients and 1190 healthy controls were included. The meta analysis showed that, there was no significant correlation between EGF61A/G gene polymorphism and schizophrenia susceptibility(A vs.G:OR= 0.99,95% CI = 0.87 - 1.12;AA vs. GG:OR = 1.00,95% CI = 0.77 - 1.29;AA vs. GA + GG: OR =0.89, 95% CI = 0.71 1.11;AA+AG vs. GG:OR = 1.07, 95% CI = 0.89-1.28}. conclusion:This meta analysis didn't demonstrate the correlation between EGF61A/G gene polymorphism and schizophrenia

  7. EGF receptor signaling blocks aryl hydrocarbon receptor-mediated transcription and cell differentiation in human epidermal keratinocytes

    OpenAIRE

    Sutter, Carrie Hayes; Yin, Hong; Li, Yunbo; Mammen, Jennifer S.; Bodreddigari, Sridevi; Stevens, Gaylene; Cole, Judith A; Sutter, Thomas R.

    2009-01-01

    Dioxin is an extremely potent carcinogen. In highly exposed people, the most commonly observed toxicity is chloracne, a pathological response of the skin. Most of the effects of dioxin are attributed to its activation of the aryl hydrocarbon receptor (AHR), a transcription factor that binds to the Ah receptor nuclear translocator (ARNT) to regulate the transcription of numerous genes, including CYP1A1 and CYP1B1. In cultures of normal human epidermal keratinocytes dioxin accelerates cell diff...

  8. Telmisartan Inhibits Cell Proliferation by Blocking Nuclear Translocation of ProHB-EGF C-Terminal Fragment in Colon Cancer Cells

    Science.gov (United States)

    Ozeki, Keiji; Tanida, Satoshi; Morimoto, Chie; Inoue, Yoshimasa; Mizoshita, Tsutomu; Tsukamoto, Hironobu; Shimura, Takaya; Kataoka, Hiromi; Kamiya, Takeshi; Nishiwaki, Eiji; Ishiguro, Hiroshi; Higashiyama, Shigeki; Joh, Takashi

    2013-01-01

    Background & Aims Current treatment target toward advanced colorectal cancers is mainly focused on the epidermal growth factor receptor (EGFR) signaling, but its additive effects with chemotherapy are still limited. A disintegrin and metalloproteinase (ADAM) cleaves the proheparin-binding epidermal growth factor like growth factor (proHB-EGF). And soluble HB-EGF activates EGFR. In parallel, the carboxy-terminal fragment of proHB-EGF (HB-EGF-CTF) translocates into the inner nuclear membrane, and subsequently exerts on the regulation of cell proliferation by binding nuclear promyelocytic leukemia zinc finger (PLZF) protein, a transcriptional repressor, thereby causing its nuclear export. We hypothesized that the inhibition of HB-EGF-CTF nuclear translocation may be a new strategy in preventing cell proliferation. Methods 12-O-tetradecanoylphorbor-13-acetate (TPA) was treated to activate ADAM. Nine-thousand chemical compounds were screened for their efficacies in blocking the binding of HB-EGF-CTF to promyelocytic leukemia zinc finger (PLZF) with Alphascreen system. The obtained candidates were then used to block the binding of HB-EGF-CTF to PLZF in colon cancer cells, HT29 and HCT116. Cell proliferation was investigated with a growth curve assay. The intracellular localization, and association between HB-EGF-CTF and PLZF, was assessed with immunofluorescent staining, and immunoprecipitation and Western blotting, respectively. The effects of obtained candidates on EGFR phosphorylation and on nuclear translocation of HB-EGF-CTF and export of PLZF during the angiotensin II type1 receptor (AT1R) knockdown were also investigated. Results Telmisartan and candesartan were found to be potential candidates. Telmisartan inhibited TPA-induced cell proliferation stronger than candesartan. Telmisartan, but not candesartan blocked the nuclear translocation of HB-EGF-CTF, and binding of HB-EGF-CTF to PLZF, during TPA stimulation. Both telmisartan and candesartan did not inhibit TPA

  9. Odin (ANKS1A modulates EGF receptor recycling and stability.

    Directory of Open Access Journals (Sweden)

    Jiefei Tong

    Full Text Available The ANKS1A gene product, also known as Odin, was first identified as a tyrosine-phosphorylated component of the epidermal growth factor receptor network. Here we show that Odin functions as an effector of EGFR recycling. In EGF-stimulated HEK293 cells tyrosine phosphorylation of Odin was induced prior to EGFR internalization and independent of EGFR-to-ERK signaling. Over-expression of Odin increased EGF-induced EGFR trafficking to recycling endosomes and recycling back to the cell surface, and decreased trafficking to lysosomes and degradation. Conversely, Odin knockdown in both HEK293 and the non-small cell lung carcinoma line RVH6849, which expresses roughly 10-fold more EGF receptors than HEK293, caused decreased EGFR recycling and accelerated trafficking to the lysosome and degradation. By governing the endocytic fate of internalized receptors, Odin may provide a layer of regulation that enables cells to contend with receptor cell densities and ligand concentration gradients that are physiologically and pathologically highly variable.

  10. Epidermal Growth Factor Induces Proliferation of Hair Follicle-Derived Mesenchymal Stem Cells Through Epidermal Growth Factor Receptor-Mediated Activation of ERK and AKT Signaling Pathways Associated with Upregulation of Cyclin D1 and Downregulation of p16.

    Science.gov (United States)

    Bai, Tingting; Liu, Feilin; Zou, Fei; Zhao, Guifang; Jiang, Yixu; Liu, Li; Shi, Jiahong; Hao, Deshun; Zhang, Qi; Zheng, Tong; Zhang, Yingyao; Liu, Mingsheng; Li, Shilun; Qi, Liangchen; Liu, Jin Yu

    2017-01-15

    The maintenance of highly proliferative capacity and full differentiation potential is a necessary step in the initiation of stem cell-based regenerative medicine. Our recent study showed that epidermal growth factor (EGF) significantly enhanced hair follicle-derived mesenchymal stem cell (HF-MSC) proliferation while maintaining the multilineage differentiation potentials. However, the underlying mechanism remains unclear. Herein, we investigated the role of EGF in HF-MSC proliferation. HF-MSCs were isolated and cultured with or without EGF. Immunofluorescence staining, flow cytometry, cytochemistry, and western blotting were used to assess proliferation, cell signaling pathways related to the EGF receptor (EGFR), and cell cycle progression. HF-MSCs exhibited surface markers of mesenchymal stem cells and displayed trilineage differentiation potentials toward adipocytes, chondrocytes, and osteoblasts. EGF significantly increased HF-MSC proliferation as well as EGFR, ERK1/2, and AKT phosphorylation (p-EGFR, p-ERK1/2, and p-AKT) in a time- and dose-dependent manner, but not STAT3 phosphorylation. EGFR inhibitor (AG1478), PI3K-AKT inhibitor (LY294002), ERK inhibitor (U0126), and STAT3 inhibitor (STA-21) significantly blocked EGF-induced HF-MSC proliferation. Moreover, AG1478, LY294002, and U0126 significantly decreased p-EGFR, p-AKT, and p-ERK1/2 expression. EGF shifted HF-MSCs at the G1 phase to the S and G2 phase. Concomitantly, cyclinD1, phosphorylated Rb, and E2F1expression increased, while that of p16 decreased. In conclusion, EGF induces HF-MSC proliferation through the EGFR/ERK and AKT pathways, but not through STAT-3. The G1/S transition was stimulated by upregulation of cyclinD1 and inhibition of p16 expression.

  11. Quetiapine and aripiprazole signal differently to ERK, p90RSK and c-Fos in mouse frontal cortex and striatum: role of the EGF receptor

    OpenAIRE

    Pereira, Avril; Zhang, Betty; Malcolm, Peter; Sugiharto-Winarno, Anthony; Sundram, Suresh

    2014-01-01

    Background Signaling pathways outside dopamine D2 receptor antagonism may govern the variable clinical profile of antipsychotic drugs (APD) in schizophrenia. One postulated mechanism causal to APD action may regulate synaptic plasticity and neuronal connectivity via the extracellular signal-regulated kinase (ERK) cascade that links G-protein coupled receptors (GPCR) and ErbB growth factor signaling, systems disturbed in schizophrenia. This was based upon our finding that the low D2 receptor a...

  12. Shh/Ptch and EGF/ErbB cooperatively regulate branching morphogenesis of fetal mouse submandibular glands.

    Science.gov (United States)

    Mizukoshi, Kenji; Koyama, Noriko; Hayashi, Toru; Zheng, Liguang; Matsuura, Sachiko; Kashimata, Masanori

    2016-04-15

    The hedgehog family includes Sonic hedgehog (Shh), Desert hedgehog, and Indian hedgehog, which are well known as a morphogens that play many important roles during development of numerous organs such as the tongue, pancreas, kidney, cartilage, teeth and salivary glands (SMG). In Shh null mice, abnormal development of the salivary gland is seen after embryonic day 14 (E14). Shh also induced lobule formation and lumen formation in acini-like structures in cultured E14 SMG. In this study, we investigated the relationship between Shh and epidermal growth factor (EGF)/ErbB signaling in developing fetal mouse SMG. Administration of Shh to cultured E13 SMG stimulated branching morphogenesis (BrM) and induced synthesis of mRNAs for EGF ligands and receptors of the ErbB family. Shh also stimulated activation of ErbB signaling system such as ERK1/2. AG1478, a specific inhibitor of ErbB receptors, completely suppressed BrM and activation of EGF/ErbB/ERK1/2 cascade in E13 SMGs cultured with Shh. The expressions of mRNA for Egf in mesenchyme and mRNA for Erbb1, Erbb2 and Erbb3 in epithelium of E13 SMG were specifically induced by administration of Shh. These results show that Shh stimulates BrM of fetal mouse SMG, at least in part, through activation of the EGF/ErbB/ERK1/2 signaling system.

  13. SMAD4 loss enables EGF, TGFβ1 and S100A8/A9 induced activation of critical pathways to invasion in human pancreatic adenocarcinoma cells.

    Science.gov (United States)

    Moz, Stefania; Basso, Daniela; Bozzato, Dania; Galozzi, Paola; Navaglia, Filippo; Negm, Ola H; Arrigoni, Giorgio; Zambon, Carlo-Federico; Padoan, Andrea; Tighe, Paddy; Todd, Ian; Franchin, Cinzia; Pedrazzoli, Sergio; Punzi, Leonardo; Plebani, Mario

    2016-10-25

    Epidermal Growth Factor (EGF) receptor overexpression, KRAS, TP53, CDKN2A and SMAD4 mutations characterize pancreatic ductal adenocarcinoma. This mutational landscape might influence cancer cells response to EGF, Transforming Growth Factor β1 (TGFβ1) and stromal inflammatory calcium binding proteins S100A8/A9. We investigated whether chronic exposure to EGF modifies in a SMAD4-dependent manner pancreatic cancer cell signalling, proliferation and invasion in response to EGF, TGFβ1 and S100A8/A9. BxPC3, homozigously deleted (HD) for SMAD4, and BxPC3-SMAD4+ cells were or not stimulated with EGF (100 ng/mL) for three days. EGF pre-treated and non pretreated cells were stimulated with a single dose of EGF (100 ng/mL), TGFβ1 (0,02 ng/mL), S100A8/A9 (10 nM). Signalling pathways (Reverse Phase Protein Array and western blot), cell migration (Matrigel) and cell proliferation (XTT) were evaluated. SMAD4 HD constitutively activated ERK and Wnt/β-catenin, while inhibiting PI3K/AKT pathways. These effects were antagonized by chronic EGF, which increased p-BAD (anti-apoptotic) in response to combined TGFβ1 and S100A8/A9 stimulation. SMAD4 HD underlied the inhibition of NF-κB and PI3K/AKT in response to TGFβ1 and S100A8/A9, which also induced cell migration. Chronic EGF exposure enhanced cell migration of both BxPC3 and BxPC3-SMAD4+, rendering the cells less sensitive to the other inflammatory stimuli. In conclusion, SMAD4 HD is associated with the constitutive activation of the ERK and Wnt/β-catenin signalling pathways, and favors the EGF-induced activation of multiple signalling pathways critical to cancer proliferation and invasion. TGFβ1 and S100A8/A9 mainly inhibit NF-κB and PI3K/AKT pathways and, when combined, sinergize with EGF in enhancing anti-apoptotic p-BAD in a SMAD4-dependent manner.

  14. Snail regulated by PKC/GSK-3β pathway is crucial for EGF-induced epithelial-mesenchymal transition (EMT) of cancer cells.

    Science.gov (United States)

    Liu, Zong-cai; Chen, Xiao-hui; Song, Hai-xing; Wang, Hong-sheng; Zhang, Ge; Wang, Hao; Chen, Dan-yang; Fang, Rui; Liu, Hao; Cai, Shao-hui; Du, Jun

    2014-11-01

    Cancer metastasis is considered a major challenge in cancer therapy. Recently, epidermal growth factor (EGF)/epidermal growth factor receptor (EGFR) signaling has been shown to induce epithelial-mesenchymal transition (EMT) and thereby to promote cancer metastasis. However, the underlying mechanism has not been fully elucidated. We demonstrate that EGF can induce EMT in human prostate and lung cancer cells and thus promote invasion and migration. EGF-induced EMT has been characterized by the cells acquiring mesenchymal spindle-like morphology and increasing their expression of N-cadherin and fibronectin, with a concomitant decrease of E-cadherin. Both protein and mRNA expression of transcription factor Snail rapidly increases after EGF treatment. The knockdown of Snail significantly attenuates EGF-induced EMT, suggesting that Snail is crucial for this process. To determine the way that Snail is accumulated, we demonstrate (1) that EGF promotes the stability of Snail via inhibiting the activity of glycogen synthase kinase 3 beta (GSK-3β), (2) that protein kinase C (PKC) rather than the phosphatidylinositide 3-kinase (PI3K)/protein kinase B (AKT) signaling pathway is responsible for GSK-3β inhibition and (3) that GSK-3β inhibition promotes the transcription of Snail. Taken together, these results reveal that the PKC/GSK-3β signaling pathway controls both the stability and transcription of Snail, which is crucial for EMT induced by EGF in PC-3 and A549 cells. Our study suggests a novel signaling pathway for Snail regulation and provides a better understanding of growth-factor-induced tumor EMT and metastasis.

  15. Advanced computational biology methods identify molecular switches for malignancy in an EGF mouse model of liver cancer.

    Directory of Open Access Journals (Sweden)

    Philip Stegmaier

    Full Text Available The molecular causes by which the epidermal growth factor receptor tyrosine kinase induces malignant transformation are largely unknown. To better understand EGFs' transforming capacity whole genome scans were applied to a transgenic mouse model of liver cancer and subjected to advanced methods of computational analysis to construct de novo gene regulatory networks based on a combination of sequence analysis and entrained graph-topological algorithms. Here we identified transcription factors, processes, key nodes and molecules to connect as yet unknown interacting partners at the level of protein-DNA interaction. Many of those could be confirmed by electromobility band shift assay at recognition sites of gene specific promoters and by western blotting of nuclear proteins. A novel cellular regulatory circuitry could therefore be proposed that connects cell cycle regulated genes with components of the EGF signaling pathway. Promoter analysis of differentially expressed genes suggested the majority of regulated transcription factors to display specificity to either the pre-tumor or the tumor state. Subsequent search for signal transduction key nodes upstream of the identified transcription factors and their targets suggested the insulin-like growth factor pathway to render the tumor cells independent of EGF receptor activity. Notably, expression of IGF2 in addition to many components of this pathway was highly upregulated in tumors. Together, we propose a switch in autocrine signaling to foster tumor growth that was initially triggered by EGF and demonstrate the knowledge gain form promoter analysis combined with upstream key node identification.

  16. Endoplasmic reticulum (ER stress inducible factor cysteine-rich with EGF-like domains 2 (Creld2 is an important mediator of BMP9-regulated osteogenic differentiation of mesenchymal stem cells.

    Directory of Open Access Journals (Sweden)

    Jiye Zhang

    Full Text Available Mesenchymal stem cells (MSCs are multipotent progenitors that can undergo osteogenic differentiation under proper stimuli. We demonstrated that BMP9 is one of the most osteogenic BMPs. However, the molecular mechanism underlying BMP9-initiated osteogenic signaling in MSCs remains unclear. Through gene expression profiling analysis we identified several candidate mediators of BMP9 osteogenic signaling. Here, we focus on one such signaling mediator and investigate the functional role of cysteine-rich with EGF-like domains 2 (Creld2 in BMP9-initiated osteogenic signaling. Creld2 was originally identified as an ER stress-inducible factor localized in the ER-Golgi apparatus. Our genomewide expression profiling analysis indicates that Creld2 is among the top up-regulated genes in BMP9-stimulated MSCs. We confirm that Creld2 is up-regulated by BMP9 in MSCs. ChIP analysis indicates that Smad1/5/8 directly binds to the Creld2 promoter in a BMP9-dependent fashion. Exogenous expression of Creld2 in MSCs potentiates BMP9-induced early and late osteogenic markers, and matrix mineralization. Conversely, silencing Creld2 expression inhibits BMP9-induced osteogenic differentiation. In vivo stem cell implantation assay reveals that exogenous Creld2 promotes BMP9-induced ectopic bone formation and matrix mineralization, whereas silencing Creld2 expression diminishes BMP9-induced bone formation and matrix mineralization. We further show that Creld2 is localized in ER and the ER stress inducers potentiate BMP9-induced osteogenic differentiation. Our results strongly suggest that Creld2 may be directly regulated by BMP9 and ER stress response may play an important role in regulating osteogenic differentiation.

  17. S100A7-downregulation inhibits epidermal growth factor-induced signaling in breast cancer cells and blocks osteoclast formation.

    Directory of Open Access Journals (Sweden)

    Vikram Paruchuri

    Full Text Available S100A7 is a small calcium binding protein, which has been shown to be differentially expressed in psoriatic skin lesions, as well as in squamous cell tumors of the skin, lung and breast. Although its expression has been correlated to HER+ high-grade tumors and to a high risk of progression, the molecular mechanisms of these S100A7-mediated tumorigenic effects are not well known. Here, we showed for the first time that epidermal growth factor (EGF induces S100A7 expression in both MCF-7 and MDA-MB-468 cell lines. We also observed a decrease in EGF-directed migration in shRNA-downregulated MDA-MB-468 cell lines. Furthermore, our signaling studies revealed that EGF induced simultaneous EGF receptor phosphorylation at Tyr1173 and HER2 phosphorylation at Tyr1248 in S100A7-downregulated cell lines as compared to the vector-transfected controls. In addition, reduced phosphorylation of Src at tyrosine 416 and p-SHP2 at tyrosine 542 was observed in these downregulated cell lines. Further studies revealed that S100A7-downregulated cells had reduced angiogenesis in vivo based on matrigel plug assays. Our results also showed decreased tumor-induced osteoclastic resorption in an intra-tibial bone injection model involving SCID mice. S100A7-downregulated cells had decreased osteoclast number and size as compared to the vector controls, and this decrease was associated with variations in IL-8 expression in in vitro cell cultures. This is a novel report on the role of S100A7 in EGF-induced signaling in breast cancer cells and in osteoclast formation.

  18. Ascofuranone suppresses EGF-induced HIF-1α protein synthesis by inhibition of the Akt/mTOR/p70S6K pathway in MDA-MB-231 breast cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Yun-Jeong; Cho, Hyun-Ji [Research Institute of Biomedical Engineering and Department of Medicine, Catholic University of Daegu School of Medicine, Daegu 705-718 (Korea, Republic of); Magae, Junji [Magae Bioscience Institute, 49-4 Fujimidai, Tsukuba 300-1263 (Japan); Lee, In-Kyu [Department of Internal Medicine, Kyungpook National University School of Medicine, Daegu 700-721 (Korea, Republic of); Park, Keun-Gyu, E-mail: kpark@knu.ac.kr [Department of Internal Medicine, Kyungpook National University School of Medicine, Daegu 700-721 (Korea, Republic of); Chang, Young-Chae, E-mail: ycchang@cu.ac.kr [Research Institute of Biomedical Engineering and Department of Medicine, Catholic University of Daegu School of Medicine, Daegu 705-718 (Korea, Republic of)

    2013-12-15

    Hypoxia-inducible factor (HIF)-1 plays an important role in tumor progression, angiogenesis and metastasis. In this study, we investigated the potential molecular mechanisms underlying the anti-angiogenic effect of ascofuranone, an isoprenoid antibiotic from Ascochyta viciae, in epidermal growth factor (EGF)-1 responsive human breast cancer cells. Ascofuranone significantly and selectively suppressed EGF-induced HIF-1α protein accumulation, whereas it did not affect the expression of HIF-1β. Furthermore, ascofuranone inhibited the transcriptional activation of vascular endothelial growth factor (VEGF) by reducing protein HIF-1α. Mechanistically, we found that the inhibitory effects of ascofuranone on HIF-1α protein expression are associated with the inhibition of synthesis HIF-1α through an EGF-dependent mechanism. In addition, ascofuranone suppressed EGF-induced phosphorylation of Akt/mTOR/p70S6 kinase, but the phosphorylation of ERK/JNK/p38 kinase was not affected by ascofuranone. These results suggest that ascofuranone suppresses EGF-induced HIF-1α protein translation through the inhibition of Akt/mTOR/p70S6 kinase signaling pathways and plays a novel role in the anti-angiogenic action. - Highlights: • Inhibitory effect of ascofuranone on HIF-1α expression is EGF-specific regulation. • Ascofuranone decreases HIF-1α protein synthesis through Akt/mTOR pathways. • Ascofuranone suppresses EGF-induced VEGF production and tumor angiogenesis.

  19. A heparin-modified thermoresponsive surface with heparin-binding epidermal growth factor-like growth factor for maintaining hepatic functions in vitro and harvesting hepatocyte sheets

    Directory of Open Access Journals (Sweden)

    Yoshinori Arisaka

    2016-03-01

    Full Text Available A heparin-modified thermoresponsive surface bound with heparin-binding epidermal growth factor-like growth factor (HB-EGF was designed to allow creation of transferrable and functional hepatocyte sheets. A heparin-modified thermoresponsive surface was prepared by covalently tethering heparin onto poly(N-isopropylacrylamide-co-2-carboxyisopropylacrylamide-grafted tissue culture polystyrene surfaces (Heparin-IC. HB-EGFs were able to stably bind to heparin-IC via affinity interaction. The survival of primary rat hepatocytes was maintained through HB-EGF-bound heparin-IC (HB-EGF/heparin-IC. Moreover, cultured rat primary hepatocytes on HB-EGF/heparin-IC exhibited higher albumin-secretion than hepatocytes cultured on PIPAAm-grafted and collagen-coated surfaces with soluble HB-EGF in the culture medium, regardless of whether soluble EGF was added. These results suggested that HB-EGF/heparin-IC is able to effectively maintain hepatic function via continuous signaling of HB-EGF. After a 4-day cultivation, the cultured hepatocytes on HB-EGF/heparin-IC detached as a cell sheet with fibronectin and HB-EGF only after the temperature was lowered to 20 °C. In addition, higher expression of hepatocyte-specific genes (albumin, hepatocyte nuclear factor 4 alpha, coagulation factor VII, and coagulation factor IX in hepatocyte sheets was detected on HB-EGF/heparin-IC than on a PIPAAm surface with soluble HB-EGF, indicating that HB-EGF/heparin-IC suppressed the dedifferentiation of cultured hepatocytes. Hence, heparin-modified thermoresponsive surfaces bound with HB-EGF facilitate the fabrication of transferrable hepatocyte sheets with intact hepatic functions and have the potential to provide an in vitro culture system using functional hepatocyte sheet tissues, which may serve as an effective hepatocyte-based tissue engineering platform for liver disease treatments.

  20. Multidimensional Strategy for Sensitive Phosphoproteomics Incorporating Protein Prefractionation Combined with SIMAC, HILIC, and TiO(2) Chromatography Applied to Proximal EGF Signaling

    DEFF Research Database (Denmark)

    Engholm-Keller, Kasper; Hansen, Thomas Aarup; Palmisano, Giuseppe;

    2011-01-01

    applied to 400 µg of protein from EGF stimulated HeLa cells. The proteins are separated into membrane and cytoplasmic fractions using sodium carbonate combined with ultracentrifugation. The phosphopeptides were separated into mono-phosphorylated and multi-phosphorylated pools using Sequential elution from...... IMAC (SIMAC) followed by hydrophilic interaction liquid chromatography of the mono- and non-phosphorylated peptides and subsequent titanium dioxide chromatography of the HILIC fractions. This strategy facilitated the identification of >4,700 unique phosphopeptides, while 636 phosphosites were changing...

  1. Tethering of Epidermal Growth Factor (EGF) to Beta Tricalcium Phosphate (βTCP) via Fusion to a High Affinity, Multimeric βTCP-Binding Peptide: Effects on Human Multipotent Stromal Cells/Connective Tissue Progenitors.

    Science.gov (United States)

    Alvarez, Luis M; Rivera, Jaime J; Stockdale, Linda; Saini, Sunil; Lee, Richard T; Griffith, Linda G

    2015-01-01

    Transplantation of freshly-aspirated autologous bone marrow, together with a scaffold, is a promising clinical alternative to harvest and transplantation of autologous bone for treatment of large defects. However, survival proliferation, and osteogenic differentiation of the marrow-resident stem and progenitor cells with osteogenic potential can be limited in large defects by the inflammatory microenvironment. Previous studies using EGF tethered to synthetic polymer substrates have demonstrated that surface-tethered EGF can protect human bone marrow-derived osteogenic stem and progenitor cells from pro-death inflammatory cues and enhance their proliferation without detriment to subsequent osteogenic differentiation. The objective of this study was to identify a facile means of tethering EGF to clinically-relevant βTCP scaffolds and to demonstrate the bioactivity of EGF tethered to βTCP using stimulation of the proliferative response of human bone-marrow derived mesenchymal stem cells (hBMSC) as a phenotypic metric. We used a phage display library and panned against βTCP and composites of βTCP with a degradable polyester biomaterial, together with orthogonal blocking schemes, to identify a 12-amino acid consensus binding peptide sequence, LLADTTHHRPWT, with high affinity for βTCP. When a single copy of this βTCP-binding peptide sequence was fused to EGF via a flexible peptide tether domain and expressed recombinantly in E. coli together with a maltose-binding domain to aid purification, the resulting fusion protein exhibited modest affinity for βTCP. However, a fusion protein containing a linear concatamer containing 10 repeats of the binding motif the resulting fusion protein showed high affinity stable binding to βTCP, with only 25% of the protein released after 7 days at 37oC. The fusion protein was bioactive, as assessed by its abilities to activate kinase signaling pathways downstream of the EGF receptor when presented in soluble form, and to enhance

  2. Tethering of Epidermal Growth Factor (EGF to Beta Tricalcium Phosphate (βTCP via Fusion to a High Affinity, Multimeric βTCP-Binding Peptide: Effects on Human Multipotent Stromal Cells/Connective Tissue Progenitors.

    Directory of Open Access Journals (Sweden)

    Luis M Alvarez

    Full Text Available Transplantation of freshly-aspirated autologous bone marrow, together with a scaffold, is a promising clinical alternative to harvest and transplantation of autologous bone for treatment of large defects. However, survival proliferation, and osteogenic differentiation of the marrow-resident stem and progenitor cells with osteogenic potential can be limited in large defects by the inflammatory microenvironment. Previous studies using EGF tethered to synthetic polymer substrates have demonstrated that surface-tethered EGF can protect human bone marrow-derived osteogenic stem and progenitor cells from pro-death inflammatory cues and enhance their proliferation without detriment to subsequent osteogenic differentiation. The objective of this study was to identify a facile means of tethering EGF to clinically-relevant βTCP scaffolds and to demonstrate the bioactivity of EGF tethered to βTCP using stimulation of the proliferative response of human bone-marrow derived mesenchymal stem cells (hBMSC as a phenotypic metric. We used a phage display library and panned against βTCP and composites of βTCP with a degradable polyester biomaterial, together with orthogonal blocking schemes, to identify a 12-amino acid consensus binding peptide sequence, LLADTTHHRPWT, with high affinity for βTCP. When a single copy of this βTCP-binding peptide sequence was fused to EGF via a flexible peptide tether domain and expressed recombinantly in E. coli together with a maltose-binding domain to aid purification, the resulting fusion protein exhibited modest affinity for βTCP. However, a fusion protein containing a linear concatamer containing 10 repeats of the binding motif the resulting fusion protein showed high affinity stable binding to βTCP, with only 25% of the protein released after 7 days at 37oC. The fusion protein was bioactive, as assessed by its abilities to activate kinase signaling pathways downstream of the EGF receptor when presented in soluble form

  3. Immunohistochemical and quantitative changes in salivary EGF, amylase and haptocorrin following radiotherapy for oral cancer

    DEFF Research Database (Denmark)

    Christensen, M E; Hansen, H S; Poulsen, Steen Seier

    1996-01-01

    Epidermal growth factor (EGF), amylase and haptocorrin are molecules produced in the salivary glands. The aim of the present study was to determine immunohistochemical and quantitative alterations in EGF as compared with haptocorrin and amylase following radiotherapy for oral cancer. Changes...... a reduction in the mitogenic peptide EGF both immunohistochemically and quantitatively following irradiation for oral cancer, results which may contribute to the understanding of the clinical signs of mucositis........ The concentration of EGF in saliva before treatment was significantly higher in patients than in the control group (p oral tumors contribute with EGF to the saliva. In conclusion we have demonstrated...

  4. Targeting EGFR-overexpressed A431 cells with EGF-labeled silica-coated magnetic nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Kralj, Slavko, E-mail: slavko.kralj@ijs.si [Jozef Stefan Institute, Department for Materials Synthesis (Slovenia); Rojnik, Matija; Kos, Janko [University of Ljubljana, Faculty of Pharmacy (Slovenia); Makovec, Darko [Jozef Stefan Institute, Department for Materials Synthesis (Slovenia)

    2013-05-15

    Human epidermal growth-factor receptor (EGFR) has emerged as an attractive target for cancer therapy. In this study, amino- or carboxyl-functionalized silica-coated maghemite nanoparticles were conjugated with epidermal growth-factor (EGF) using five different binding modes: carbodiimide chemistry, two types of homo-bifunctional cross-linking reagents, and electrostatic interactions between the nanoparticles and the EGF. The nanoparticles and their aqueous suspensions were characterized by transmission electron microscopy, zeta-potential measurements and dynamic light scattering. The binding efficiency of the EGF to the nanoparticles was measured by flow cytometry using a specific anti-EGF antibody. The ability of EGF bioconjugates to target the EGF receptors was tested using EGFR over-expressing A431 cells in comparison to EGFR negative HeLa cells. Our results showed that the bioconjugates where the EGF was bonded by carbodiimide chemistry are the most effective for the specific targeting of EGFR-expressing cells in vitro.

  5. Gene expression profiles of some cytokines, growth factors, receptors, and enzymes (GM-CSF, IFNγ, MMP-2, IGF-II, EGF, TGF-β, IGF-IIR) during pregnancy in the cat uterus.

    Science.gov (United States)

    Agaoglu, Ozgecan Korkmaz; Agaoglu, Ali Reha; Guzeloglu, Aydin; Aslan, Selim; Kurar, Ercan; Kayis, Seyit Ali; Schäfer-Somi, Sabine

    2016-03-01

    Early pregnancy is one of the most critical periods of pregnancy, and many factors such as cytokines, enzymes, and members of the immune system have to cooperate in a balanced way. In the present study, the gene expression profiles of factors associated with pregnancy such as EGF, transforming growth factor beta, granulocyte-macrophage colony-stimulating factor, interferon gamma, insulin-like growth factor 2, insulin-like growth factor 2 receptor, and matrix metalloproteinase 2 were analyzed in uterine tissues of female cats. The cats were assigned to five groups: G1 (embryo positive, n = 7; 7th day after mating), G2 (after implantation, n = 7; 20th day after mating), G3 (midgestation, n = 7; 24-25th day after mating), G4 (late gestation, n = 7; 30-45th day after mating), G5 (oocyte group, n = 7; 7th day after estrus). Tissue samples from the uterus and placenta were collected after ovariohysterectomy. Relative messenger RNA levels were determined by real-time polymerase chain reaction. All the factors examined were detected in all tissue samples. In the course of pregnancy, significantly higher expression of EGF and matrix metalloproteinase 2 in G2 than in G1 was observed (P < 0.05). Insulin-like growth factor 2 expression was higher in all groups than in G1 (P < 0.05). Upregulation of EGF during implantation was detected. The expression of interferon gamma was significantly higher in G3 than in G1 (P < 0.05). Transforming growth factor beta and granulocyte-macrophage colony-stimulating factor were constantly expressed in all groups. In conclusion, the expressions of these factors in feline uterine tissue at different stages of pregnancy might indicate that these factors play roles in the development of pregnancy such as trophoblast invasion, vascularization, implantation, and placentation.

  6. Context-Dependent Sensitivity to Mutations Disrupting the Structural Integrity of Individual EGF Repeats in the Mouse Notch Ligand DLL1.

    Science.gov (United States)

    Schuster-Gossler, Karin; Cordes, Ralf; Müller, Julia; Geffers, Insa; Delany-Heiken, Patricia; Taft, Manuel; Preller, Matthias; Gossler, Achim

    2016-03-01

    The highly conserved Notch-signaling pathway mediates cell-to-cell communication and is pivotal for multiple developmental processes and tissue homeostasis in adult organisms. Notch receptors and their ligands are transmembrane proteins with multiple epidermal-growth-factor-like (EGF) repeats in their extracellular domains. In vitro the EGF repeats of mammalian ligands that are essential for Notch activation have been defined. However, in vivo the significance of the structural integrity of each EGF repeat in the ligand ectodomain for ligand function is still unclear. Here, we analyzed the mouse Notch ligand DLL1. We expressed DLL1 proteins with mutations disrupting disulfide bridges in each individual EGF repeat from single-copy transgenes in the HPRT locus of embryonic stem cells. In Notch transactivation assays all mutations impinged on DLL1 function and affected both NOTCH1 and NOTCH2 receptors similarly. An allelic series in mice that carried the same point mutations in endogenous Dll1, generated using a mini-gene strategy, showed that early developmental processes depending on DLL1-mediated NOTCH activation were differently sensitive to mutation of individual EGF repeats in DLL1. Notably, some mutations affected only somite patterning and resulted in vertebral column defects resembling spondylocostal dysostosis. In conclusion, the structural integrity of each individual EGF repeat in the extracellular domain of DLL1 is necessary for full DLL1 activity, and certain mutations in Dll1 might contribute to spondylocostal dysostosis in humans.

  7. Genetic variations in EGF and EGFR and glioblastoma outcome

    DEFF Research Database (Denmark)

    Sjöström, Sara; Andersson, Ulrika; Liu, Yanhong;

    2010-01-01

    Few prognostic factors have been associated with glioblastoma survival. We analyzed a complete tagging of the epidermal growth factor (EGF) and EGF receptor (EGFR) gene polymorphisms as potential prognostic factors. Thirty tagging single-nucleotide polymorphisms (SNPs) in EGF and 89 tagging SNPs...... in EGFR were analyzed for association with survival in 176 glioblastoma cases. Validation analyses were performed for 4 SNPs in a set of 638 glioblastoma patients recruited at The University of Texas M. D. Anderson Cancer Center (MDACC). Three hundred and seventy-four glioblastoma patients aged 50 years...... or older at diagnosis were subanalyzed to enrich for de novo arising glioblastoma. We found 7 SNPs in haplotype 4 in EGF that were associated with prognosis in glioblastoma patients. In EGFR, 4 of 89 SNPs were significantly associated with prognosis but judged as false positives. Four of the significantly...

  8. Nuclear phosphoproteomics analysis reveals that CDK1/2 are involved in EGF-regulated constitutive pre-mRNA splicing in MDA-MB-468 cells.

    Science.gov (United States)

    Chen, Xianwei; Guo, Dan; Zhu, Yinghui; Xian, Feng; Liu, Siqi; Wu, Lin; Lou, Xiaomin

    2016-06-01

    The epidermal growth factor (EGF) receptor (EGFR) pathway is one of the most dysregulated and extensively investigated signaling pathways in human cancers and plays important roles in the regulation of nuclear functions through both cytoplasmic and nuclear EGFR pathways. However, the current understanding of the nuclear phosphorylation responses to activated EGFR pathways remains limited. In the present study, phosphoproteomics analysis revealed the increased phosphorylation of 90 nuclear proteins, primarily involved in RNA processing, pre-mRNA splicing and cell cycle regulation, upon EGF stimulation in MDA-MB-468 cells. Cellular splicing assays of the β-globin (HBB) minigene confirmed that EGF induced constitutive pre-mRNA splicing. Further analysis of phosphoproteomics data identified multiple CDK1/2 substrates in pre-mRNA splicing-related proteins, and both CDK1/2 inhibitors and CDK1/2 knockdowns reduced EGF-regulated pre-mRNA splicing. In conclusion, the results of the present study provide evidence that CDK1/2 participate in the regulation of constitutive pre-mRNA splicing by EGF stimulation in MDA-MB-468 cells. In this study, we successfully carried out a survey of nuclear phosphorylation changes in response to EGF stimulation. The results from the functional category analysis and pre-mRNA splicing assay strongly indicated that EGFR activation increased constitutive pre-mRNA splicing in MDA-MB-468 cells, revealing additional role of EGFR on regulation of mRNA maturation beyond alternative pre-mRNA splicing reported by previous studies. Furthermore, we found that CDK1/2 participated in constitutive pre-mRNA splicing regulation by EGF in MDA-MB-468 cells. Our study provides new knowledge for understanding the regulation of constitutive pre-mRNA splicing by EGF stimulation. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. EGF Functionalized Polymer-Coated Gold Nanoparticles Promote EGF Photostability and EGFR Internalization for Photothermal Therapy

    Science.gov (United States)

    Silva, Catarina Oliveira; Petersen, Steffen B.; Reis, Catarina Pinto; Rijo, Patrícia; Molpeceres, Jesús; Fernandes, Ana Sofia; Gonçalves, Odete; Gomes, Andreia C.; Correia, Isabel; Vorum, Henrik; Neves-Petersen, Maria Teresa

    2016-01-01

    The application of functionalized nanocarriers on photothermal therapy for cancer ablation has wide interest. The success of this application depends on the therapeutic efficiency and biocompatibility of the system, but also on the stability and biorecognition of the conjugated protein. This study aims at investigating the hypothesis that EGF functionalized polymer-coated gold nanoparticles promote EGF photostability and EGFR internalization, making these conjugated particles suitable for photothermal therapy. The conjugated gold nanoparticles (100–200 nm) showed a plasmon absorption band located within the near-infrared range (650–900 nm), optimal for photothermal therapy applications. The effects of temperature, of polymer-coated gold nanoparticles and of UVB light (295nm) on the fluorescence properties of EGF have been investigated with steady-state and time-resolved fluorescence spectroscopy. The fluorescence properties of EGF, including the formation of Trp and Tyr photoproducts, is modulated by temperature and by the intensity of the excitation light. The presence of polymeric-coated gold nanoparticles reduced or even avoided the formation of Trp and Tyr photoproducts when EGF is exposed to UVB light, protecting this way the structure and function of EGF. Cytotoxicity studies of conjugated nanoparticles carried out in normal-like human keratinocytes showed small, concentration dependent decreases in cell viability (0–25%). Moreover, conjugated nanoparticles could activate and induce the internalization of overexpressed Epidermal Growth Factor Receptor in human lung carcinoma cells. In conclusion, the gold nanoparticles conjugated with Epidermal Growth Factor and coated with biopolymers developed in this work, show a potential application for near infrared photothermal therapy, which may efficiently destroy solid tumours, reducing the damage of the healthy tissue. PMID:27788212

  10. The expression of epidermal growth factor (EGF) in hemangioma and vascular malformation%表皮生长因子在血管瘤和血管畸形中的表达

    Institute of Scientific and Technical Information of China (English)

    王毅; 刘振平; 黄世杰; 金明哲; 胡明

    2010-01-01

    Objective To investigate the expression of EGF in hemangioma (HG) and vascular malformation (VM). Methods Between March 1998 and October 2005,92 patients including 72 patients with HG and 20 patients with VM were recruited in this study. Among of them,52 were female,and 40 were male. Patients' age ranged from 40 days to 13 years old with an average age of 1.6 years old. All the samples were collected from the resected tiddues, and were fixed by 10% neutral formaldehyde solution. Ten normal skin samples were taken as controls. H&E stain and immunohistochemical staining of EGF were performed on tissue sections. Results The expression of EGF was significantly increased in HG group, and decreased in VM group (P<0. 001 ). The EGF expression of HG group peaked in the proliferative phase, and decreased gradually in the involuting and involuted phases. The expression of EGF varied directly with the proliferation of vascular endothelial cells in HG patients (P <0. 001 ). Conclusions EGF is related to the proliferation and involution of HG but not VM. EGF promotes the proliferation of HG by affecting the proliferation of vascular endothelial cells.%目的 了解表皮生长因子(epidermal growth factor,EGF)与血管瘤及血管畸形的关系.方法 标本选自1998年3月至2005年10月经手术切除的先天性皮肤血管病变92例患儿,女52例,男40例,年龄为40 d至13岁,平均年龄为1.6岁.组织标本取出后立即浸入10%的中性甲醛溶液中固定,常规石蜡包埋,5μm连续切片,HE染色,同时采用含有正常血管的皮肤标本10例作为对照.采用免疫组织化学方法,对72例血管瘤和20例血管畸形组织切片进行EGF表达的测定.结果 EGF在血管瘤组织中高表达,而在血管畸形组织中低表达(P<0.01).在血管瘤增殖期、退化早期和退化完成期三者之间,EGF的表达存在着差异.在血管瘤中EGF的表达与其内皮细胞的增生程度有关.内皮细胞增生越强,EGF的表达越高(P<0.05).

  11. Smurf1 plays a role in EGF inhibition of BMP2-induced osteogenic differentiation

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hye-Lim; Park, Hyun-Jung; Kwon, Arang [Department of Molecular Genetics, School of Dentistry and Dental Research Institute, Seoul National University, Seoul 110-749 (Korea, Republic of); Baek, Kyunghwa [Department of Pharmacology, College of Dentistry and Research Institute of Oral Science, Gangneung-Wonju National University, Gangneung 210-702, Gangwondo (Korea, Republic of); Woo, Kyung Mi; Ryoo, Hyun-Mo; Kim, Gwan-Shik [Department of Molecular Genetics, School of Dentistry and Dental Research Institute, Seoul National University, Seoul 110-749 (Korea, Republic of); Baek, Jeong-Hwa, E-mail: baekjh@snu.ac.kr [Department of Molecular Genetics, School of Dentistry and Dental Research Institute, Seoul National University, Seoul 110-749 (Korea, Republic of)

    2014-05-01

    It has been demonstrated that epidermal growth factor (EGF) plays a role in supporting the proliferation of bone marrow stromal cells in bone but inhibits their osteogenic differentiation. However, the mechanism underlying EGF inhibition of osteoblast differentiation remains unclear. Smurf1 is an E3 ubiquitin ligase that targets Smad1/5 and Runx2, which are critical transcription factors for bone morphogenetic protein 2 (BMP2)-induced osteoblast differentiation. In this study, we investigated the effect of EGF on the expression of Smurf1, and the role of Smurf1 in EGF inhibition of osteogenic differentiation using C2C12 cells, a murine myoblast cell line. EGF increased Smurf1 expression, which was blocked by inhibiting the activity of either JNK or ERK. Chromatin immunoprecipitation and Smurf1 promoter assays demonstrated that c-Jun and Runx2 play roles in the EGF induction of Smurf1 transcription. EGF suppressed BMP2-induced expression of osteogenic marker genes, which were rescued by Smurf1 knockdown. EGF downregulated the protein levels of Runx2 and Smad1 in a proteasome-dependent manner. EGF decreased the transcriptional activity of Runx2 and Smurf1, which was partially rescued by Smurf1 silencing. Taken together, these results suggest that EGF increases Smurf1 expression via the activation of JNK and ERK and the subsequent binding of c-Jun and Runx2 to the Smurf1 promoter and that Smurf1 mediates the inhibitory effect of EGF on BMP2-induced osteoblast differentiation. - Highlights: • EGF increases the expression level of Smurf1 in mesenchymal precursor cells. • EGF reduces the protein levels and transcriptional activity of Runx2 and Smad1. • EGF suppresses BMP2-induced osteogenic differentiation, which is rescued by Smurf1 knockdown.

  12. Effects of FGF-2 and EGF removal on the differentiationof mouse neural precursor cells

    Directory of Open Access Journals (Sweden)

    Telma T. Schwindt

    2009-09-01

    Full Text Available Cell therapy for neurological disorders has advanced, and neural precursor cells (NPC may become the ideal candidates for neural transplantation in a wide range of diseases. However, additional work has to be done to determine either the ideal culture environment for NPC expansion in vitro, without altering their plasticity, or the FGF-2 and EGF mechanisms of cell signaling in neurospheres growth, survival and differentiation. In this work we evaluated mouse neurospheres cultured with and without FGF-2 and EGF containing medium and showed that those growth factors are responsible for NPC proliferation. It is also demonstrated that endogenous production of growth factors shifts from FGF-2 to IGF-1/PDGFb upon EGF and FGF-2 withdrawal. Mouse NPC cultured in suspension showed different patterns of neuronal localization (core versus shell for both EGF and FGF-2 withdrawal and control groups. Taken together, these results show that EGF and FGF-2 removal play an important role in NPC differentiation and may contribute to a better understanding of mechanisms of NPC differentiation. Our findings suggest that depriving NPC of growth factors prior to grafting might enhance their chance to effectively integrate into the host.As terapias celulares para doenças neurológicas têm avançado e células precursoras neurais (NPC surgem como candidatas ideais para o transplante de células neurais em muitas doenças. No entanto, trabalhos adicionais devem ser feitos para determinar o ambiente de cultivo ideal para a expansão in vitro das NPC, sem alterar sua plasticidade, e os mecanismos de sinalização celular do fator de crescimento epidérmico (EGF e fator de crescimento de fibroblasto 2 (FGF-2 no crescimento, sobrevivência e diferenciação da neuroesfera. Nesse trabalho avaliamosNPCcultivadas na presença e na ausência de FGF-2 e EGF e mostramos que esses fatores de crescimento são responsáveis pela proliferação das NPC. Também foi demonstrado que a

  13. The cell-penetrating peptide domain from human heparin-binding epidermal growth factor-like growth factor (HB-EGF) has anti-inflammatory activity in vitro and in vivo

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jue-Yeon; Seo, Yoo-Na; Park, Hyun-Jung [Research Center, Nano Intelligent Biomedical Engineering Corporation (NIBEC), Seoul (Korea, Republic of); Park, Yoon-Jeong, E-mail: parkyj@snu.ac.kr [Research Center, Nano Intelligent Biomedical Engineering Corporation (NIBEC), Seoul (Korea, Republic of); Department of Dental Regenerative Biotechnology, Dental Research Institute and School of Dentistry, Seoul National University, Seoul (Korea, Republic of); Chung, Chong-Pyoung, E-mail: ccpperio@snu.ac.kr [Research Center, Nano Intelligent Biomedical Engineering Corporation (NIBEC), Seoul (Korea, Republic of); Department of Periodontology, College of Dentistry, Seoul National University, Seoul (Korea, Republic of)

    2012-03-23

    Highlights: Black-Right-Pointing-Pointer HBP sequence identified from HB-EGF has cell penetration activity. Black-Right-Pointing-Pointer HBP inhibits the NF-{kappa}B dependent inflammatory responses. Black-Right-Pointing-Pointer HBP directly blocks phosphorylation and degradation of I{kappa}B{alpha}. Black-Right-Pointing-Pointer HBP inhibits nuclear translocation of NF-{kappa}B p65 subunit. -- Abstract: A heparin-binding peptide (HBP) sequence from human heparin-binding epidermal growth factor-like growth factor (HB-EGF) was identified and was shown to exhibit cell penetration activity. This cell penetration induced an anti-inflammatory reaction in lipopolysaccharide (LPS)-treated RAW 264.7 macrophages. HBP penetrated the cell membrane during the 10 min treatment and reduced the LPS-induced production of nitric oxide (NO), inducible nitric oxide synthase (iNOS), and cytokines (TNF-{alpha} and IL-6) in a concentration-dependent manner. Additionally, HBP inhibited the LPS-induced upregulation of cytokines, including TNF-{alpha} and IL-6, and decreased the interstitial infiltration of polymorphonuclear leukocytes in a lung inflammation model. HBP inhibited NF-{kappa}B-dependent inflammatory responses by directly blocking the phosphorylation and degradation of I{kappa}B{alpha} and by subsequently inhibiting the nuclear translocation of the p65 subunit of NF-{kappa}B. Taken together, this novel HBP may be potentially useful candidate for anti-inflammatory treatments and can be combined with other drugs of interest to transport attached molecules into cells.

  14. Lipid raft localization of epidermal growth factor receptor alters matrix metalloproteinase-1 expression in SiHa cells via the MAPK/ERK signaling pathway

    Science.gov (United States)

    Zhang, Zongfeng; Wang, Lina; Du, Juan; Li, Yuanbo; Yang, Huilun; Li, Chenxi; Li, Hui; Hu, Haiyang

    2016-01-01

    Matrix metalloproteinase-1 (MMP-1) has been identified as an important participant in tumor invasion, metastasis and angiogenesis. The purpose of the present study was to investigate the effects of epidermal growth factor receptor (EGFR) localization to lipid rafts on signaling pathways involved in the regulation of MMP-1 expression in SiHa cells, a cervical cancer cell line. EGFR activation by EGF specifically induced MMP-1 expression at both the messenger RNA and protein levels. Additionally, it was observed that EGFR localized to lipid rafts, and that the redistribution of EGFR induced by lipid raft disruption strengthened EGF-induced MMP-1 expression. MMP-1 induction was blocked by the mitogen-activated protein kinase (MAPK) kinase inhibitors PD98059 and U0126. Our results suggested that lipid rafts provide a platform to inhibit EGFR regulation of MMP-1 in SiHa cells through the MAPK/extracellular signal-regulated kinase signaling pathway.

  15. Lysyl oxidase drives tumour progression by trapping EGF receptors at the cell surface.

    Science.gov (United States)

    Tang, HaoRan; Leung, Leo; Saturno, Grazia; Viros, Amaya; Smith, Duncan; Di Leva, Gianpiero; Morrison, Eamonn; Niculescu-Duvaz, Dan; Lopes, Filipa; Johnson, Louise; Dhomen, Nathalie; Springer, Caroline; Marais, Richard

    2017-04-18

    Lysyl oxidase (LOX) remodels the tumour microenvironment by cross-linking the extracellular matrix. LOX overexpression is associated with poor cancer outcomes. Here, we find that LOX regulates the epidermal growth factor receptor (EGFR) to drive tumour progression. We show that LOX regulates EGFR by suppressing TGFβ1 signalling through the secreted protease HTRA1. This increases the expression of Matrilin2 (MATN2), an EGF-like domain-containing protein that traps EGFR at the cell surface to facilitate its activation by EGF. We describe a pharmacological inhibitor of LOX, CCT365623, which disrupts EGFR cell surface retention and delays the growth of primary and metastatic tumour cells in vivo. Thus, we show that LOX regulates EGFR cell surface retention to drive tumour progression, and we validate the therapeutic potential of inhibiting this pathway with the small molecule inhibitor CCT365623.

  16. Inhibition of EGF Uptake by Nephrotoxic Antisense Drugs In Vitro and Implications for Preclinical Safety Profiling

    Directory of Open Access Journals (Sweden)

    Annie Moisan

    2017-03-01

    Full Text Available Antisense oligonucleotide (AON therapeutics offer new avenues to pursue clinically relevant targets inaccessible with other technologies. Advances in improving AON affinity and stability by incorporation of high affinity nucleotides, such as locked nucleic acids (LNA, have sometimes been stifled by safety liabilities related to their accumulation in the kidney tubule. In an attempt to predict and understand the mechanisms of LNA-AON-induced renal tubular toxicity, we established human cell models that recapitulate in vivo behavior of pre-clinically and clinically unfavorable LNA-AON drug candidates. We identified elevation of extracellular epidermal growth factor (EGF as a robust and sensitive in vitro biomarker of LNA-AON-induced cytotoxicity in human kidney tubule epithelial cells. We report the time-dependent negative regulation of EGF uptake and EGF receptor (EGFR signaling by toxic but not innocuous LNA-AONs and revealed the importance of EGFR signaling in LNA-AON-mediated decrease in cellular activity. The robust EGF-based in vitro safety profiling of LNA-AON drug candidates presented here, together with a better understanding of the underlying molecular mechanisms, constitutes a significant step toward developing safer antisense therapeutics.

  17. Toxicological evaluation of u-hEGF.

    Science.gov (United States)

    Maraschin, R; Bussi, R; Conz, A; Orlando, L; Pirovano, R; Nyska, A

    1995-01-01

    The toxicological evaluation of urinary human epidermal growth factor (u-hEGF) included mutagenicity, single and repeated dose general toxicity, and teratogenicity studies in various animal species. The mutagenic potential of u-hEGF was tested in vitro (Ames test, chromosome aberration in human lymphocytes, unscheduled DNA synthesis in HeLa cells) and in vivo (chromosome aberration in Chinese hamster bone marrow and micronucleus test in rat bone marrow). No mutagenic or clastogenic effects were found. The acute toxicity of u-hEGF was evaluated in mice and rats, using single subcutaneous (sc) or intravenous (i.v.) injection of 15 mg/kg. No toxic effects were observed Four-week i.v. daily administration of u-hEGF at the doses of 0.3, o.9, and 3 mg/kg in the SD rat followed by 2 wk of compound withdrawal induced pronounced and generally dose-related effects (i.e., epithelial hyperplasia) in a wide range of tissues and organs, at all doses. However, these effects were not apparently detrimental to the general health of the rats. The repeated sc administration of u-hEGF to cynomolgus monkeys for 4 wk at the same doses as used in the rat study resulted in lethality after about 7 days of treatment in the 2 higher dose groups or after 14 days at the lowest dose. The main clinical signs observed were gastrointestinal effects, respiratory distress, sedation, marked loss of body weight, and cutaneous desquamation. At histology, hyperplasia of most epithelia was seen in all groups. In addition, atrophy of the ovarian follicles and necrosis of the uterine endometrium were noted. Changes considered secondary to physical distress were atrophy of the hemopoietic and lymphatic system and hepatic steatosis. The embryofetal toxicity and teratogenicity of u-hEGF was tested, using the i.v. route in the SD rat and the i.v. and sc routes in the New Zealand White rabbit. In both species, the compound was administered at the doses of 0, 0.3, 0.9, and 3 mg/kg/day, from day 6 to 15 of

  18. Comparative biodistribution of potential anti-glioblastoma conjugates [111In]DTPA-hEGF and [111In]Bz-DTPA-hEGF in normal mice.

    Science.gov (United States)

    Tolmachev, Vladimir; Orlova, Anna; Wei, Qichun; Bruskin, Alexander; Carlsson, Jörgen; Gedda, Lars

    2004-08-01

    EGF-receptors (EGFR) are overexpressed in gliomas, as well as in tumors of breast, lung, and urinary bladder. For this reason, EGFR may be an attractive target for both visualization and therapy of malignant tumors using radioactive nuclides. Natural ligand of EGFR, epidermal growth factor (EGF) is a small 53-amino-acid protein. Low molecular weight of EGF may enable better intratumoral penetration in comparison to antibodies. [111In]DTPA-EGF was proposed for the targeting of glioblastoma and breast cancer, and its tumor-seeking properties were confirmed in animal studies. The aim of this study was to evaluate how the substitution of heptadentate DTPA for octadentate benzyl-DTPA (Bz-DTPA) effects the biodistribution of indium-labeled human EGF (hEGF) in normal NMRI mice. [111In]DTPA-hEGF and [111In]Bz-DTPA-hEGF, obtained by the coupling of ITC-benzyl-DTPA to hEGF, were injected into the tail vein. At 0.5, 1, 4, and 24 hours postinjection, the animals were sacrificed, and radioactivity in different organs was measured. The blood clearance of both conjugates was fast. The uptake of both conjugates in the liver, spleen, stomach, pancreas, intestines, and submaxillary gland was most likely receptor-mediated. The uptake in a majority of organs was similar. However, indium uptake in the case of [111In]DTPA-hEGF was significantly higher in the kidneys and bones. In conclusion, [111In]Bz-DTPA-hEGF seems to have more favourable in vivo distribution in comparison to [111In]DTPA-hEGF.

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

    DEFF Research Database (Denmark)

    Dengjel, Joern; Akimov, Vyacheslav; Blagoev, Blagoy;

    2007-01-01

    -out by mass spectrometry-based proteomics has allowed exciting views on the very early events in signal transduction. Activation profiles of regulated phosphorylation sites on epidermal growth factor receptor and downstream signal transducers showed different kinetics within the first ten seconds...

  20. Effects of EGF or bFGF on the development of porcine parthenogenetic embryos in vitro

    Institute of Scientific and Technical Information of China (English)

    Ji LIU; Shutang FENG; Dengke PAN; Liguo GONG; Li ZHANG; Yulian MU; Zirong WANG

    2008-01-01

    Epidermal growth factor (EGF) and basic fibroblast growth factor (bFGF) were added into the cul-ture medium in different culturing stages. The effects of EGF or bFGF on the development of porcine partheno-genetic embryos were studied in vitro. The results were as follows: The addition of EGF significantly enhanced the cleavage rate of porcine parthenogenetic embryos (P<0.05). The addition of EGF or bFGF also signifi-cantly enhanced the rate of blastocysts formation of 2-4-cell porcine parthenogenetic embryos (P<0.05). Additionally, the group of bFGF had more numbers of blastocysts and higher rates of blastocysts formation than the groups of EGF and the control. In conclusion, EGF and bFGF were found propitious to the development of porcine parthenogenetic embryos in vitro, and bFGF increased the quality of blastocysts by increasing the total cell number in porcine parthenogenetic embryos.

  1. Synergistic Inhibitory Effects of Cetuximab and Cisplatin on Human Colon Cancer Cell Growth via Inhibition of the ERK-Dependent EGF Receptor Signaling Pathway

    Directory of Open Access Journals (Sweden)

    Dong Ju Son

    2015-01-01

    Full Text Available The purpose of this study was to evaluate the anticancer efficacy of cetuximab combined with cisplatin (combination treatment on colon cancer growth, as well as its underlying action mechanism. Combination treatment synergistically potentiated the effect of cetuximab on cell growth inhibition and apoptosis induction in HCT116 and SW480 cells. Combination treatment further suppressed the expression of the activated form of epidermal growth factor receptor (EGFR and MAP kinase (p-ERK and p-p38 and also significantly inhibited the activity of activator protein-1 (AP-1 and nuclear factor kappa B (NF-κB. Additionally, the expression of cyclooxygenase-2 (COX-2 and interleukin-8 (IL-8 mRNA was significantly reduced by the combination treatment as compared to the expression seen for treatment with cetuximab or cisplatin alone. We found that the synergistic inhibitory effects of cetuximab and cisplatin on AP-1 and NF-κB activation, as well as on cell viability, were reversed by pretreatment with an ERK inhibitor. Results demonstrate that combined treatment with cetuximab and cisplatin exerts synergistic anticancer effects on colon cancer cells and also suggest that the ERK pathway plays a critical role in these effects via the suppression of the EGFR signaling pathway, along with the inhibition of COX-2, IL-8, and AP-1 and NF-κB.

  2. Increased expression of heparin binding EGF (HB-EGF), amphiregulin, TGF alpha and epiregulin in androgen-independent prostate cancer cell lines.

    DEFF Research Database (Denmark)

    Tørring, Niels; Sørensen, Boe Sandahl; Nexø, Ebba

    2000-01-01

    BACKGROUND: The proliferation of androgen-independent prostate cancer cell lines has previously been shown to be influenced by an autocrine loop of the epidermal growth factor (EGF) system. This observation has alerted us to study the expression of ligands and receptors from the EGF-system in pro...

  3. Evolutionary origin of rhizobium Nod factor signaling

    NARCIS (Netherlands)

    Streng, A.; Camp, Op den R.; Bisseling, T.; Geurts, R.

    2011-01-01

    For over two decades now, it is known that the nodule symbiosis between legume plants and nitrogen fixing rhizobium bacteria is set in motion by the bacterial signal molecule named nodulation (Nod) factor.1 Upon Nod factor perception a signaling cascade is activated that is also essential for endomy

  4. Epidermal Growth Factor and Intestinal Barrier Function

    Directory of Open Access Journals (Sweden)

    Xiaopeng Tang

    2016-01-01

    Full Text Available Epidermal growth factor (EGF is a 53-amino acid peptide that plays an important role in regulating cell growth, survival, migration, apoptosis, proliferation, and differentiation. In addition, EGF has been established to be an effective intestinal regulator helping to protect intestinal barrier integrity, which was essential for the absorption of nutrients and health in humans and animals. Several researches have demonstrated that EGF via binding to the EGF receptor and subsequent activation of Ras/MAPK, PI3K/AKT, PLC-γ/PKC, and STATS signal pathways regulates intestinal barrier function. In this review, the relationship between epidermal growth factor and intestinal development and intestinal barrier is described, to provide a better understanding of the effects of EGF on intestine development and health.

  5. Immunohistochemical and quantitative changes in salivary EGF, amylase and haptocorrin following radiotherapy for oral cancer

    DEFF Research Database (Denmark)

    Christensen, M E; Hansen, H S; Poulsen, Steen Seier

    1996-01-01

    Epidermal growth factor (EGF), amylase and haptocorrin are molecules produced in the salivary glands. The aim of the present study was to determine immunohistochemical and quantitative alterations in EGF as compared with haptocorrin and amylase following radiotherapy for oral cancer. Changes...... in the salivary secretion of EGF are of interest because of the importance of EGF in mucosal regeneration. Immunohistochemical studies on normal tissue from parotid and submandibular glands have demonstrated EGF in the serous acini with a tendency to single cell expression in the parotid gland. Amylase has been...... found in the serous acini of both the submandibular and parotid glands. Haptocorrin was localized in the duct system of both glands. In the submandibular glands with radiotherapy induced sialoadenitis only very few acini with weak or no staining for EGF and amylase were demonstrated, while no changes...

  6. Epidermal growth factor and ras regulate gene expression in GH4 pituitary cells by separate, antagonistic signal transduction pathways

    Energy Technology Data Exchange (ETDEWEB)

    Pickett, C.A.; Gutierrez-Hartmann, A. [Univ. of Colorado Health Sciences Center, Denver, CO (United States)

    1995-12-01

    This report discusses the role of the epidermal growth factor (EGF) in promoting activation of the rat prolactin promoter in neuroendocrine cells via a Ras-independent mechanism. It also discusses the role of phosphotransferases in mediating EGF response. 32 refs., 8 figs., 1 tab.

  7. Interaction of the EGF Receptor and the Hippo Pathway in the Diabetic Kidney.

    Science.gov (United States)

    Chen, Jianchun; Harris, Raymond C

    2016-06-01

    Activation of the EGF receptor (EGFR) or the Hippo signaling pathway can control cell proliferation, apoptosis, and differentiation, and the dysregulation of these pathways can contribute to tumorigenesis. Previous studies showed that activation of EGFR signaling in renal epithelial cells can exacerbate diabetic kidney injury. Moreover, EGFR has been implicated in regulating the Hippo signaling pathway in Drosophila; thus, we examined this potential interaction in mammalian diabetic kidney disease. Yes-associated protein (YAP) is a transcriptional regulator regulated by the Hippo signaling pathway. We found YAP protein expression and phosphorylation were upregulated in diabetic mouse renal proximal tubule epithelial cells, which were inhibited in diabetic proximal tubule EGFR-knockout mice (EGFR(ptKO)) or administration of an EGFR tyrosine kinase inhibitor erlotinib. Furthermore, activation of an EGFR-PI3K-Akt-CREB signaling pathway mediated YAP gene expression and YAP nuclear translocation and interaction with the TEA domain (TEAD) transcription factor complex, which led to upregulated expression of two TEAD-dependent genes, the connective tissue growth factor and amphiregulin genes. In a renal proximal tubule cell line, either pharmacologic or genetic inhibition of EGFR, Akt, or CREB blunted YAP expression in response to high-glucose treatment. Additionally, knocking down YAP expression by specific siRNA inhibited cell proliferation in response to high glucose or exogenous EGF. Therefore, these results link the Hippo pathway to EGFR-mediated renal epithelial injury in diabetes. Copyright © 2016 by the American Society of Nephrology.

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

    Science.gov (United States)

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

    2016-06-01

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

  9. Potentiation of growth factor signaling by insulin-like growth factor-binding protein-3 in breast epithelial cells requires sphingosine kinase activity.

    Science.gov (United States)

    Martin, Janet L; Lin, Mike Z; McGowan, Eileen M; Baxter, Robert C

    2009-09-18

    We have investigated the mechanism underlying potentiation of epidermal growth factor receptor (EGFR) and type 1 insulin-like growth factor receptor (IGFR1) signaling by IGF-binding protein-3 (IGFBP-3) in MCF-10A breast epithelial cells, focusing on a possible involvement of the sphingosine kinase (SphK) system. IGFBP-3 potentiated EGF-stimulated EGF receptor activation and DNA synthesis, and this was blocked by inhibitors of SphK activity or small interference RNA-mediated silencing of SphK1, but not SphK2, expression. Similarly, IGFR1 phosphorylation and DNA synthesis stimulated by LR3-IGF-I (an IGF-I analog not bound by IGFBP-3), were enhanced by IGFBP-3, and this was blocked by SphK1 silencing. SphK1 expression and activity were stimulated by IGFBP-3 approximately 2-fold over 24 h. Silencing of sphingosine 1-phosphate receptor 1 (S1P1) or S1P3, but not S1P2, abolished the effect of IGFBP-3 on EGF-stimulated EGFR activation. The effects of IGFBP-3 could be reproduced with exogenous S1P or medium conditioned by cells treated with IGFBP-3, and this was also blocked by inhibition of S1P1 and S1P3. These data indicate that potentiation of growth factor signaling by IGFBP-3 in MCF-10A cells requires SphK1 activity and S1P1/S1P3, suggesting that S1P, the product of SphK activity and ligand for S1P1 and S1P3, is the "missing link" mediating IGF and EGFR transactivation and cell growth stimulation by IGFBP-3.

  10. Evolutionary origin of rhizobium Nod factor signaling.

    Science.gov (United States)

    Streng, Arend; op den Camp, Rik; Bisseling, Ton; Geurts, René

    2011-10-01

    For over two decades now, it is known that the nodule symbiosis between legume plants and nitrogen fixing rhizobium bacteria is set in motion by the bacterial signal molecule named nodulation (Nod) factor. Upon Nod factor perception a signaling cascade is activated that is also essential for endomycorrhizal symbiosis (Fig. 1). This suggests that rhizobium co-opted the evolutionary far more ancient mycorrhizal signaling pathway in order to establish an endosymbiotic interaction with legumes. As arbuscular mycorrhizal fungi of the Glomeromycota phylum can establish a symbiosis with the fast majority of land plants, it is most probable that this signaling cascade is wide spread in plant kingdom. However, Nod factor perception generally is considered to be unique to legumes. Two recent breakthroughs on the evolutionary origin of Rhizobium Nod factor signaling demonstrate that this is not the case. The purification of Nod factor-like molecules excreted by the mycorrhizal fungus Glomus intraradices and the role of the LysM-type Nod factor receptor PaNFP in the non-legume Parasponia andersonii provide novel understanding on the evolution of rhizobial Nod factor signaling.

  11. Troglitazone inhibits cell proliferation by attenuation of epidermal growth factor receptor signaling independent of peroxisome proliferator-activated receptor γ

    Institute of Scientific and Technical Information of China (English)

    Xiaoqi Li; Xuanming Yang; Youli Xu; Xuejun Jiang; Xin Li; Fajun Nan; Hong Tang

    2009-01-01

    Peroxisome proliferator-activated receptors (PPAR) belong to the nuclear hormone receptor superfamily of ligand-dependent transcription factors. Recent results have shown that agonists of PPARy, such as troglitazone (TGZ), can inhibit cell proliferation and promote cell differentiation independent of PPARγ. In the present study, we provide evidence that TGZ may bind directly to EGFR and trigger its signaling and internalization independent of PPARγ. Detailed studies revealed that prolonged incubation with TGZ effectively attenuated EGFR signaling by target-ing the receptor to the endo-lysosomal degradation machinery. Although the extracellular signal-regulated kinase-signaling pathway was transiently activated by TGZ in EGFR overexpressing cancer cells, inhibition of EGF-induced Akt phosphorylation most likely accounted for the growth arrest of tumor cells caused by TGZ at pharmacologically achievable concentrations. Therefore, we have provided a new line of evidence indicating that TGZ inhibits cell pro-liferation by promoting EGFR degradation and attenuating Akt phosphorylation.

  12. Is receptor oligomerization causally linked to activation of the EGF receptor kinase?

    Science.gov (United States)

    Rintoul, D. A.; Spooner, B. S. (Principal Investigator)

    1992-01-01

    Transduction of a signal from an extracellular peptide hormone to produce an intracellular response is often mediated by a cell surface receptor, which is usually a glycoprotein. The secondary intracellular signal(s) generated after hormone binding to the receptor have been intensively studied. The nature of the primary signal generated by ligand binding to the receptor is understood less well in most cases. The particular case of the epidermal growth factor (EGF) receptor is analyzed, and evidence for or against two dissimilar models of primary signal transduction is reviewed. Evidence for the most widely accepted current model is found to be unconvincing. Evidence for the other model is substantial but indirect; a direct test of this model remains to be done.

  13. Gastrointestinal hormones stimulate growth of Foregut Neuroendocrine Tumors by transactivating the EGF receptor.

    Science.gov (United States)

    Di Florio, Alessia; Sancho, Veronica; Moreno, Paola; Delle Fave, Gianfranco; Jensen, Robert T

    2013-03-01

    Foregut neuroendocrine tumors [NETs] usually pursuit a benign course, but some show aggressive behavior. The treatment of patients with advanced NETs is marginally effective and new approaches are needed. In other tumors, transactivation of the EGF receptor (EGFR) by growth factors, gastrointestinal (GI) hormones and lipids can stimulate growth, which has led to new treatments. Recent studies show a direct correlation between NET malignancy and EGFR expression, EGFR inhibition decreases basal NET growth and an autocrine growth effect exerted by GI hormones, for some NETs. To determine if GI hormones can stimulate NET growth by inducing transactivation of EGFR, we examined the ability of EGF, TGFα and various GI hormones to stimulate growth of the human foregut carcinoid,BON, the somatostatinoma QGP-1 and the rat islet tumor,Rin-14B-cell lines. The EGFR tyrosine-kinase inhibitor, AG1478 strongly inhibited EGF and the GI hormones stimulated cell growth, both in BON and QGP-1 cells. In all the three neuroendocrine cell lines studied, we found EGF, TGFα and the other growth-stimulating GI hormones increased Tyr(1068) EGFR phosphorylation. In BON cells, both the GI hormones neurotensin and a bombesin analogue caused a time- and dose-dependent increase in EGFR phosphorylation, which was strongly inhibited by AG1478. Moreover, we found this stimulated phosphorylation was dependent on Src kinases, PKCs, matrix metalloproteinase activation and the generation of reactive oxygen species. These results raise the possibility that disruption of this signaling cascade by either EGFR inhibition alone or combined with receptor antagonists may be a novel therapeutic approach for treatment of foregut NETs/PETs.

  14. Epidermal Growth Factor-dependent Activation of the Extracellular Signal-regulated Kinase Pathway by DJ-1 Protein through Its Direct Binding to c-Raf Protein*

    Science.gov (United States)

    Takahashi-Niki, Kazuko; Kato-Ose, Izumi; Murata, Hiroaki; Maita, Hiroshi; Iguchi-Ariga, Sanae M. M.; Ariga, Hiroyoshi

    2015-01-01

    DJ-1 is an oncogene and also a causative gene for familial Parkinson disease. DJ-1 has various functions, and the oxidative status of cysteine at position 106 (Cys-106) is crucial for determination of the activation level of DJ-1. Although DJ-1 requires activated Ras for its oncogenic activity and although it activates the extracellular signal-regulated kinase (ERK) pathway, a cell growth pathway downstream of Ras, the precise mechanism underlying activation of the ERK pathway by DJ-1 is still not known. In this study, we found that DJ-1 directly bound to the kinase domain of c-Raf but not to Ras and that Cys-106 mutant DJ-1 bound to c-Raf more weakly than did wild-type DJ-1. Co-localization of DJ-1 with c-Raf in the cytoplasm was enhanced in epidermal growth factor (EGF)-treated cells. Knockdown of DJ-1 expression attenuated the phosphorylation level of c-Raf in EGF-treated cells, resulting in reduced activation of MEK and ERK1/2. Although EGF-treated DJ-1 knock-out cells also showed attenuated c-Raf activation, reintroduction of wild-type DJ-1, but not C106S DJ-1, into DJ-1 knock-out cells restored c-Raf activation in a DJ-1 binding activity in a c-Raf-dependent manner. DJ-1 was not responsible for activation of c-Raf in phorbol myristate acetate-treated cells. Furthermore, DJ-1 stimulated self-phosphorylation activity of c-Raf in vitro, but DJ-1 was not a target for Raf kinase. Oxidation of Cys-106 in DJ-1 was not affected by EGF treatment. These findings showed that DJ-1 is a positive regulator of the EGF/Ras/ERK pathway through targeting c-Raf. PMID:26048984

  15. Analysis of epidermal growth factor signaling in nasal mucosa epithelial cell proliferation involved in chronic rhinosinusitis

    Institute of Scientific and Technical Information of China (English)

    Li Yunchuan; Li Lijuan; Wang Tong; Zang Hongrui; An Yunsong; Li Lifeng; Zhang Junyi

    2014-01-01

    Background Aberrant epithelial repair has been observed in chronic rhinosinusitis (CRS) patients; however,the mechanism of epithelial cell repair regulation is unclear.Epidermal growth factor (EGF) plays an important role in regulating epithelial cell repair in lower airway and may be a critical factor in the remodeling processes of CRS.The objective of our research is to evaluate the differences between CRS and normal subjects and between chronic rhinosinusitis without nasal polys (CRSsNP) and chronic rhinosinusitis with nasal polys (CRSwNP) in the regulation of EGF pathways and the regulating proliferative position of classic Ras/Raf/MEK/ERK pathways.Methods We evaluated the proliferation rates of ethmoidal mucosal cells before and after stimulation with EGF,epidermal growth factor receptor (EGFR) kinase inhibitor AG1478,and extracellular signal-regulated kinase 1/2 (ERK1/2) inhibitor PD98059 using MTT assays.We also analyzed the sinonasal epithelial cells collected from control subjects and patients with CRS subtypes CRSsNP and CRSwNP for the expression of ERK1/2,phosphorylated ERK1/2,P21,P15,and P27 using western blotting analyses.Results The proliferation rates of sinonasal epithelial cells before and after EGF stimulation were lower in CRS patients than in the controls.AG1478 or PD98059 inhibitor treatment of control epithelial cells did not result in a significant difference in proliferation.Although,AG1478 and PD98059 inhibited the proliferation of CRS cells,the degree of proliferation inhibition was markedly different in CRSsNP.AG 1478 suppressed the proliferation of CRSwNP epithelial cells,whereas PD98059 had no effect.The ratio of ERK1/2 phosphorylation in CRS cells was lower than that of the control cells.Cyclin-dependent kinase inhibitors were highly expressed in CRS cells compared with that of control cells.ERK1/2 and P27 showed differential expression in CRSsNP and CRSwNP.Conclusions Differences existed in EGF pathways in CRS patients and normal

  16. Construction and Purification of EGF-Linker-TCSKDEL Fusion Proteins%EGF-Linker-TCSKDEL融合蛋白的构建及表达产物的纯化

    Institute of Scientific and Technical Information of China (English)

    李玉萍

    2015-01-01

    目的构建EGF-Linker-TCSKDEL融合蛋白表达载体并纯化目的蛋白。方法以天花粉蛋白基因的改造产物TCSKDEL为毒素,人表皮生长因子EGFR为载体,构建重组免疫毒素EGF-Linker-TCSKDEL。PCR方法扩增EGF-Linker-TCSKDEL基因片段,插入表达载体PET28a中并诱导表达,使用Ni-NTA Agrose亲合层析纯化。结果该融合蛋白以可溶形式表达于大肠杆菌培养上清中,并获得有效纯化。结论成功构建了新型融合蛋白EGF-Linker-TCSKDEL,为其进一步的基础和临床研究奠定基础。%Objective To construct the expression vector of EGF-Linker-TCSKDEL fusion proteins and purify target protein. Methods Recombinant immunotoxin (EGF-Linker-TCSKDEL) was constructed by modified trichosanthin (TCS) with KDEL as toxin and epidermal growth factor (EGF) as a car ier. The DNA fragment of EGF-Linker-TCSKDEL was amplified by using PCR, and the fusion proteins were purified by Ni-NTA Agrose af inity chromatography. Results The fusion protein was expressed in a form of soluble protein and purified ef ectively using af inity chromatography. Conclusion A new EGF-Linker-TCSKDEL fusion proteins was successful y prepared. It laid a foundation of further research in basic and clinical of EGF-Linker-TCSKDEL.

  17. Co-expression of epidermal growth factor-receptor and c-erb B-2 proto-oncogene product in human salivary-gland adenocarcinoma cell line HSG and the implications for HSG cell autocrine growth.

    Science.gov (United States)

    Kyakumoto, S; Kurokawa, R; Hoshino, M; Ota, M

    1994-07-01

    The autonomous proliferation of HSG cells is mediated by an autocrine growth factor, a 46K epidermal growth factor (EGF)-like molecule. The receptor for this molecule was investigated. Immunoprecipitation and immunoblotting revealed the expression of two possible receptor molecules, EGF-R and p185erbB-2, in HSG cells. Northern blotting also revealed the co-expression of 5.6-kb EGF-R mRNA and 4.6-kb c-erb B-2 mRNA. When the purified EGF-like molecule was added to the cultures, EGF-R but not p185erbB-2 was autophosphorylated. These results suggest that, although both EGF-R and p185erbB-2 are co-expressed in HSG cells, the EGF-R is the genuine receptor for the EGF-like molecule. However, there is a possibility that p185erB-2 is involved in the signal transduction system. This possibility was examined by using specific antibodies to human EGF-R (hEGF-R), p185erbB-2, and EGF to inhibit the functions of these molecules. Addition of these three antibodies to the cultures inhibited the growth of HSG cells. The antibodies to EGF-R and p185erbB-2 also caused morphological changes such as disturbances of the plasma membrane, and some cell death. Surprisingly, the effect of the anti-p185erbB-2 antibody on growth inhibition and morphology was stronger than that of the anti-hEGF-R antibody. Thus, p185erB-2 expressed in HSG cells has an important function in the signal transduction of HSG cell growth.

  18. DNA methylation dynamics in the rat EGF gene promoter after partial hepatectomy

    Directory of Open Access Journals (Sweden)

    Deming Li

    2014-06-01

    Full Text Available Epidermal growth factor (EGF, a multifunctional growth factor, is a regulator in a wide variety of physiological processes. EGF plays an important role in the regulation of liver regeneration. This study was aimed at investigating the methylation level of EGF gene throughout liver regeneration. DNA of liver tissue from control rats and partial hepatectomy (PH rats at 10 time points was extracted and a 354 bp fragment including 10 CpG sites from the transcription start was amplified after DNA was modified by sodium bisulfate. The result of sequencing suggested that methylation ratio of four CpG sites was found to be significantly changed when PH group was compared to control group, in particular two of them were extremely striking. mRNA expression of EGF was down-regulated in total during liver regeneration. We think that the rat EGF promoter region is regulated by variation in DNA methylation during liver regeneration.

  19. Temperature dependence of the epidermal growth factor receptor signaling network can be accounted for by a kinetic model.

    Science.gov (United States)

    Moehren, Gisela; Markevich, Nick; Demin, Oleg; Kiyatkin, Anatoly; Goryanin, Igor; Hoek, Jan B; Kholodenko, Boris N

    2002-01-08

    Stimulation of isolated hepatocytes with epidermal growth factor (EGF) causes rapid tyrosine phosphorylation of the EGF receptor (EGFR) and adapter/target proteins, which was monitored with 1 and 2 s resolution at 37, 20, and 4 degrees C. The temporal responses detected for multiple signaling proteins involve both transient and sustained phosphorylation patterns, which change dramatically at low temperatures. To account quantitatively for complex responses, we employed a mechanistic kinetic model of the EGFR pathway, formulated in molecular terms as cascades of protein interactions and phosphorylation and dephosphorylation reactions. Assuming differential temperature dependencies for different reaction groups, such as SH2 and PTB domain-mediated interactions, the EGFR kinase, and the phosphatases, good quantitative agreement was obtained between computer-simulated and measured responses. The kinetic model demonstrates that, for each protein-protein interaction, the dissociation rate constant, k(off), strongly decreases at low temperatures, whereas this decline may or may not be accompanied by a large decrease in the k(on) value. Temperature-induced changes in the maximal activities of the reactions catalyzed by the EGFR kinase were moderate, compared to such changes in the V(max) of the phosphatases. However, strong changes in both the V(max) and K(m) for phosphatases resulted in moderate changes in the V(max)/K(m) ratio, comparable to the corresponding changes in EGFR kinase activity, with a single exception for the receptor phosphatase at 4 degrees C. The model suggests a significant decrease in the rates of the EGF receptor dimerization and its dephosphorylation at 4 degrees C, which can be related to the phase transition in the membrane lipids. A combination of high-resolution experimental monitoring and molecular level kinetic modeling made it possible to quantitatively account for the temperature dependence of the integrative signaling responses.

  20. The expression characteristics and biological significance of bFGF, EGF,TGF-β isoforms and their receptors in skins from fetus and adult

    Institute of Scientific and Technical Information of China (English)

    Chen Wei; Fu Xiaobing; Sun Xiaoqing; Sun Tongzhu; Zhao Zhili; Sheng Zhiyong

    2002-01-01

    To observe the localization and expression characteristics of alpha-smooth muscle actin (AS-MA), basic fibroblast growth factor (bFGF), epidermal growth factor (EGF), transforming growth factor-β(TGF-β) isoforms, and their receptors in fetal and adult skins in order to explore their potential biological significance.Methods: The expression and the distribution of ASMA, bFGF, EGF, TGF-βisoforms, and their receptors were detected with immunohistochemistry and histopathology methods in 36 skin specimens. Among them, 30 specimens belonged to fetuses at different developmental stages and 6 were from adults. Results:Positive immunohistochemical signals of ASMA, bFGF, EGF, and TGF-βisoforms and their receptors could be found in fetal and postnatal skins.These factors were mainly distributed in the cytoplasm and extracellular matrix of epidermal cells, endothelial cells,hair follicle epithelial cells and some fibroblasts. Receptors of these factors were mostly located in the cellular membrane of the above mentioned cells, while protein particles of ASMA could be observed in myofibroblasts and sweat gland cells. Along with ascent in gestational age, the positive cellular rates of bFGF, EGF, TGF-βisoforms, their receptors, and ASMA in skin were elevated progressively. In skins specimens obtained from fetuses of late-trimester (29-31 week gestation) and adult, the positive rates of these proteins were significantly raised in comparison with skin of fetuses of early-trimester. Conclusion: The endogenous bFGF, EGF, three TGF-βisoforms and their receptors might be involved in the development of the skin in embryonic stage and in the cutaneous structure and function,and also wound healing in adult stage. The relative lack of these factors and their receptors might be one reason why the wound of fetus heal by regeneration rather than by scarring.

  1. The Relationships between Polymorphisms in Genes Encoding the Growth Factors TGF-β1, PDGFB, EGF, bFGF and VEGF-A and the Restenosis Process in Patients with Stable Coronary Artery Disease Treated with Bare Metal Stent.

    Directory of Open Access Journals (Sweden)

    Tadeusz Osadnik

    Full Text Available Neointima forming after stent implantation consists of vascular smooth muscle cells (VSMCs in 90%. Growth factors TGF-β1, PDGFB, EGF, bFGF and VEGF-A play an important role in VSMC proliferation and migration to the tunica intima after arterial wall injury. The aim of this paper was an analysis of functional polymorphisms in genes encoding TGF-β1, PDGFB, EGF, bFGF and VEGF-A in relation to in-stent restenosis (ISR.265 patients with a stable coronary artery disease (SCAD hospitalized in our center in the years 2007-2011 were included in the study. All patients underwent stent implantation at admission to the hospital and had another coronary angiography performed due to recurrence of the ailments or a positive result of the test assessing the coronary flow reserve. Angiographically significant ISR was defined as stenosis >50% in the stented coronary artery segment. The patients were divided into two groups-with angiographically significant ISR (n = 53 and without significant ISR (n = 212. Additionally, the assessment of late lumen loss (LLL in vessel was performed. EGF rs4444903 polymorphism was genotyped using the PCR-RFLP method whilst rs1800470 (TGFB1, rs2285094 (PDGFB rs308395 (bFGF and rs699947 (VEGF-A were determined using the TaqMan method.Angiographically significant ISR was significantly less frequently observed in the group of patients with the A/A genotype of rs1800470 polymorphism (TGFB1 versus patients with A/G and G/G genotypes. In the multivariable analysis, LLL was significantly lower in patients with the A/A genotype of rs1800470 (TGFB1 versus those with the A/G and G/G genotypes and higher in patients with the A/A genotype of the VEGF-A polymorphism versus the A/C and C/C genotypes. The C/C genotype of rs2285094 (PDGFB was associated with greater LLL compared to C/T heterozygotes and T/T homozygotes.The polymorphisms rs1800470, rs2285094 and rs6999447 of the TGFB1, PDGFB and VEGF-A genes, respectively, are associated with LLL

  2. TIMP-1 is under regulation of the EGF signaling axis and promotes an aggressive phenotype in KRAS-mutated colorectal cancer cells

    DEFF Research Database (Denmark)

    Tarpgaard, Line S; Ørum-Madsen, Maj Sofie; Christensen, Ib J;

    2016-01-01

    It is now widely accepted that therapeutic antibodies targeting epidermal growth factor receptor (EGFR) can have efficacy in KRAS wild-type advanced colorectal cancer (CRC) patients. What remains to be ascertained is whether a subgroup of KRAS-mutated CRC patients might not also derive benefit from....... The two sets of data, clinical and in vitro, are complementary and support each other, lending strength to our contention that TIMP- 1 plasma levels can identify a subset of patients with KRAS-mutated metastatic CRC that will have benefit from EGFR-inhibition therapy....... EGFR inhibitors. Metalloproteinase inhibitor 1 (TIMP-1) is a pleiotropic factor predictive of survival outcome of CRC patients. Levels of TIMP-1 were measured in pre-treatment plasma samples (n = 426) of metastatic CRC patients randomized to Nordic FLOX (5-fluorouracil and oxaliplatin) +/- cetuximab...

  3. Induction of PD-L1 expression by epidermal growth factor receptor–mediated signaling in esophageal squamous cell carcinoma

    Science.gov (United States)

    Zhang, Wencheng; Pang, Qingsong; Yan, Cihui; Wang, Qifeng; Yang, Jingsong; Yu, Shufei; Liu, Xiao; Yuan, Zhiyong; Wang, Ping; Xiao, Zefen

    2017-01-01

    Purpose The purpose of this study was to investigate the potential effect of activation of epidermal growth factor receptor (EGFR) signaling pathway on the expression of programmed death-ligand 1 (PD-L1) in esophageal squamous cell carcinoma (ESCC) cells with EGFR overexpression. Methods Flow cytometry and Western blot methods were used to assess PD-L1 expression on ESCC cells when EGFR signaling pathway was activated by epidermal growth factor (EGF) with or without EGFR-specific inhibitor AG-1478, and then EGFR signaling array was applied to analyze the potential signaling pathways involved. Results This study found that PD-L1 expression increased significantly in an EGFR-dependent manner by the activation of EGFR signaling and decreased sharply when EGFR signaling was blocked. The upregulated expression of PD-L1 was not associated with EGFR-STAT3 signaling pathway, but may be affected by EGFR–PI3K–AKT, EGFR–Ras–Raf–Erk, and EGR–PLC-γ signaling pathways. Conclusion The expression of PD-L1 can be regulated by EGFR signaling activation in ESCC, which indicates an important role for EGFR-mediated immune escape and potential molecular pathways for EGFR-targeted therapy and immunotherapy.

  4. Treatment with Anti-EGF Ab Ameliorates Experimental Autoimmune Encephalomyelitis via Induction of Neurogenesis and Oligodendrogenesis

    Directory of Open Access Journals (Sweden)

    Yifat Amir-Levy

    2014-01-01

    Full Text Available Background. The neural stem cells (NSCs migrate to the damaged sites in multiple sclerosis (MS and in experimental autoimmune encephalomyelitis (EAE. However, the differentiation into neurons or oligodendrocytes is blocked. Epidermal growth factor (EGF stimulates NSC proliferation and mobilization to demyelinated lesions but also induces astrogenesis and glial scar. Objective. To examine the clinical and histopathological effects of EGF neutralization on EAE. Methods. EAE-induced SJL mice were intravenously treated with either anti-EGF neutralizing antibody (Ab or isotype control or PBS. On day 9 after immunization, 3 mice of each group were daily treated for 9 days with BrdU and then sacrificed for immunohistochemical analysis. Results. Treatment with anti-EGF Ab significantly ameliorated EAE symptoms during the second relapse. Anti-EGF Ab induced a shift from BrdU+GFAP+ NSCs to BrdU+DCX+ neuroblasts in the subventricular zone (SVZ, increased BrdU+NeuN+ neurons in the granular cell layer of the dentate gyrus, and increased BrdU+O4+ oligodendrocytes in the SVZ. There was no change in the inflammatory infiltrates in response to anti-EGF Ab. Conclusions. Therapy with anti-EGF Ab ameliorates EAE via induction of neurogenesis and oligodendrogenesis. No immunosuppressive effect was found. Further investigation is needed to support these notions of beneficial effect of anti-EGF Ab in MS.

  5. TIMP-1 is under regulation of the EGF signaling axis and promotes an aggressive phenotype in KRAS-mutated colorectal cancer cells

    DEFF Research Database (Denmark)

    Tarpgaard, Line S; Ørum-Madsen, Maj Sofie; Christensen, Ib J;

    2016-01-01

    It is now widely accepted that therapeutic antibodies targeting epidermal growth factor receptor (EGFR) can have efficacy in KRAS wild-type advanced colorectal cancer (CRC) patients. What remains to be ascertained is whether a subgroup of KRAS-mutated CRC patients might not also derive benefit fr....... The two sets of data, clinical and in vitro, are complementary and support each other, lending strength to our contention that TIMP- 1 plasma levels can identify a subset of patients with KRAS-mutated metastatic CRC that will have benefit from EGFR-inhibition therapy....

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-09-09

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

  7. MicroRNA miR-24 enhances tumor invasion and metastasis by targeting PTPN9 and PTPRF to promote EGF signaling.

    Science.gov (United States)

    Du, William W; Fang, Ling; Li, Minhui; Yang, Xiangling; Liang, Yaoyun; Peng, Chun; Qian, Wei; O'Malley, Yunxia Q; Askeland, Ryan W; Sugg, Sonia L; Qian, Jun; Lin, Jiang; Jiang, Zide; Yee, Albert J; Sefton, Michael; Deng, Zhaoqun; Shan, Sze Wan; Wang, Chia-Hui; Yang, Burton B

    2013-03-15

    MicroRNAs are known to play regulatory roles in gene expression associated with cancer development. We analyzed levels of the microRNA miR-24 in patients with breast carcinoma and found that miR-24 was higher in breast carcinoma samples than in benign breast tissues. We generated constructs expressing miR-24 and studied its functions using both in vitro and in vivo techniques. We found that the ectopic expression of miR-24 promoted breast cancer cell invasion and migration. In vivo experiments in mice indicated that the expression of miR-24 enhanced tumor growth, invasion into local tissues, metastasis to lung tissues and decreased overall mouse survival. In the miR-24-expressing cells and tumors, EGFR was highly phosphorylated, whereas expression of the phosphatases tyrosine-protein phosphatase non-receptor type 9 (PTPN9) and receptor-type tyrosine-protein phosphatase F (PTPRF) were repressed. We confirmed that miR-24 could directly target both PTPN9 and PTPRF. Consistent with this, we found that the levels of phosphorylated epidermal growth factor receptor (pEGFR) were higher whereas the levels of PTPN9 and PTPRF were lower in the patients with metastatic breast carcinoma. Ectopic expression of PTPN9 and PTPRF decreased pEGFR levels, cell invasion, migration and tumor metastasis. Furthermore, we found that MMP2, MMP11, pErk, and ADAM15 were upregulated, whereas TIMP2 was downregulated; all of which supported the roles of miR-24 in tumor invasion and metastasis. Our results suggest that miR-24 plays a key role in breast cancer invasion and metastasis. miR-24 could potentially be a target for cancer intervention.

  8. THE CONSUMPTION OF ACAI PULP CHANGES THE CONCENTRATIONS OF PLASMINOGEN ACTIVATOR INHIBITOR-1 AND EPIDERMAL GROWTH FACTOR (EGF) IN APPARENTLY HEALTHY WOMEN.

    Science.gov (United States)

    de Sousa Pereira, Izabelle; Moreira Cançado Mascarenhas Pontes, Tereza Cristina; Lima Vieira, Renata Adrielle; de Freitas Folly, Gilce Andrezza; Cacilda Silva, Fernanda; Pereira de Oliveira, Fernando Luiz; Ferreira do Amaral, Joana; Nascimento de Freitas, Renata; Pinheiro Volp, Ana Carolina

    2015-08-01

    Introducción: la obesidad, que se caracteriza por el exceso de adiposidad, se asocia con disfunción endotelial y posible estado inflamatorio con liberación de citoquinas que determinan la función endotelial y pueden desencadenar enfermedades crónicas. El patrón de dieta está asociado con la síntesis de estas citoquinas. Los frutos de el acai, que es rico en flavonoides, tienen un efecto directo y positivo en el control de este proceso inflamatorio a través de los ejercicios de la capacidad antioxidante. Objetivo: evaluar el efecto del consumo de pulpa de acai en los marcadores inflamatorios, las medidas antropométricas, la composición corporal y los parámetros bioquímicos y dietéticos en mujeres sanas. Métodos: cuarenta mujeres fueron divididas en 25 eutróficas y 15 con sobrepeso. Se las adeministró 200 g de pulpa de acai durante 4 semanas. Antes y después de la intervención se evaluaron: medidas antropométricas, composición corporal, marcadores inflamatorios, datos bioquímicos, ingesta dietética y antioxidantes en la dieta. Resultados y discusión: después de la intervención, hubo un aumento significativo de EGF (p = 0,021) y PAI-1 (p = 0,011) en las mujeres con sobrepeso. Por otra parte, en las mujeres eutróficas hubo aumento del peso corporal (p = 0,031), el índice de masa corporal (p = 0,028), el porcentaje de grasa del tronco (p = 0,003) y el espesor del pliegue cutáneo del tríceps (p = 0,046). Sin embargo, el espesor del pliegue cutáneo (p = 0,018) y la grasa corporal total (p = 0,016) se redujeron en las mujeres con sobrepeso. Hubo una reducción de la proteína total (p = 0,049) debida a la disminución de globulina (p = 0,005), pero el estado nutricional se mantuvo en el grupo eutrófico. Conclusión: la ingesta de 200 g de pulpa de acai modula el EGF y PAI-1 de expresión, posiblemente por la modulación del acai en los parámetros de la composición corporal, la dieta, clínicos, bioquímicos e inflamatorios, lo que dio

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

    Science.gov (United States)

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

    2013-05-07

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

  10. Arf6 regulates EGF-induced internalization of E-cadherin in breast cancer cells.

    Science.gov (United States)

    Xu, Rui; Zhang, Yujie; Gu, Luo; Zheng, Jianchao; Cui, Jie; Dong, Jing; Du, Jun

    2015-01-01

    E-cadherin internalization facilitates dissolution of adherens junctions and promotes tumor cell epithelial-mesenchymal transition (EMT) and migration. Our previous results have shown that Arf6 exerts pro-migratory action in breast cancer cells after EGF stimulation. Despite the fact that EGF signaling stimulates EMT of breast cancer cells, the effect of Arf6 on internalization of E-cadherin of breast cancer cells under EGF treatment remains to be determined. Here, we showed that EGF dose-dependently stimulated E-cadherin internalization by MCF-7 cells with the maximal effect at 50 ng/ml. Meanwhile, EGF treatment markedly increased Arf6 activation. Arf6 was involved in complexes of E-cadherin, and more E-cadherin was pulled down with Arf6 when the activity of the latter was increased. Immunoblotting and immunofluorescence assays showed that transfection breast cancer cells with Arf6-T27N or Arf6 siRNA suppressed EGF-induced E-cadherin internalization. Taken together, our study demonstrated that Arf6 activation plays a potential role in EGF-induced E-cadherin internalization, providing new mechanism underlying the effect of Arf6 on promoting breast cancer cell metastasis.

  11. Insulin-Like Growth Factor Receptor Signaling is Necessary for Epidermal Growth Factor Mediated Proliferation of SVZ Neural Precursors Following Neonatal Hypoxia-Ischemia

    Directory of Open Access Journals (Sweden)

    Dhivyaa eAlagappan

    2014-05-01

    Full Text Available In this study we assessed the importance of insulin-like growth factor (IGF and epidermal growth factor (EGF receptor co-signaling for rat neural precursor (NP cell proliferation and self-renewal in the context of a developmental brain injury that is associated with cerebral palsy. Consistent with previous studies, we found that there is an increase in the in vitro growth of subventricular zone (SVZ NPs isolated acutely after cerebral hypoxia-ischemia; however, when cultured in medium that is insufficient to stimulate the IGF type 1 receptor, neurosphere formation and the proliferative capacity of those NPs was severely curtailed. This reduced growth capacity could not be attributed simply to failure to survive. The growth and self-renewal of the NPs could be restored by addition of both IGF-I and IGF-II. Since the size of the neurosphere is predominantly due to cell proliferation we hypothesized that the IGFs were regulating progression through the cell cycle. Analyses of cell cycle progression revealed that IGF-1R activation together with EGFR co-signaling decreased the percentage of cells in G1 and enhanced cell progression into S and G2. This was accompanied by increases in expression of cyclin D1, phosphorylated histone 3 and phosphorylated Rb. Based on these data we conclude that coordinate signaling between the EGF receptor and the IGF type 1 receptor is necessary for the normal proliferation of NPs as well as for their reactive expansion after injury. These data indicate that manipulations that maintain or amplify IGF signaling in the brain during recovery from developmental brain injuries will enhance the production of new brain cells to improve neurological function in children who are at risk for developing cerebral palsy.

  12. Cellular signaling by fibroblast growth factor receptors.

    Science.gov (United States)

    Eswarakumar, V P; Lax, I; Schlessinger, J

    2005-04-01

    The 22 members of the fibroblast growth factor (FGF) family of growth factors mediate their cellular responses by binding to and activating the different isoforms encoded by the four receptor tyrosine kinases (RTKs) designated FGFR1, FGFR2, FGFR3 and FGFR4. Unlike other growth factors, FGFs act in concert with heparin or heparan sulfate proteoglycan (HSPG) to activate FGFRs and to induce the pleiotropic responses that lead to the variety of cellular responses induced by this large family of growth factors. A variety of human skeletal dysplasias have been linked to specific point mutations in FGFR1, FGFR2 and FGFR3 leading to severe impairment in cranial, digital and skeletal development. Gain of function mutations in FGFRs were also identified in a variety of human cancers such as myeloproliferative syndromes, lymphomas, prostate and breast cancers as well as other malignant diseases. The binding of FGF and HSPG to the extracellular ligand domain of FGFR induces receptor dimerization, activation and autophosphorylation of multiple tyrosine residues in the cytoplasmic domain of the receptor molecule. A variety of signaling proteins are phosphorylated in response to FGF stimulation including Shc, phospholipase-Cgamma, STAT1, Gab1 and FRS2alpha leading to stimulation of intracellular signaling pathways that control cell proliferation, cell differentiation, cell migration, cell survival and cell shape. The docking proteins FRS2alpha and FRS2beta are major mediators of the Ras/MAPK and PI-3 kinase/Akt signaling pathways as well as negative feedback mechanisms that fine-tune the signal that is initiated at the cell surface following FGFR stimulation.

  13. Quantitation of multisite EGF receptor phosphorylation using mass spectrometry and a novel normalization approach

    DEFF Research Database (Denmark)

    Erba, Elisabetta Boeri; Matthiesen, Rune; Bunkenborg, Jakob

    2007-01-01

    Using stable isotope labeling and mass spectrometry, we performed a sensitive, quantitative analysis of multiple phosphorylation sites of the epidermal growth factor (EGF) receptor. Phosphopeptide detection efficiency was significantly improved by using the tyrosine phosphatase inhibitor sodium p...

  14. Epidermal growth factor stimulates Rac activation through Src and phosphatidylinositol 3-kinase to promote colonic epithelial cell migration.

    Science.gov (United States)

    Dise, Rebecca S; Frey, Mark R; Whitehead, Robert H; Polk, D Brent

    2008-01-01

    Regulated intestinal epithelial cell migration plays a key role in wound healing and maintenance of a healthy gastrointestinal tract. Epidermal growth factor (EGF) stimulates cell migration and wound closure in intestinal epithelial cells through incompletely understood mechanisms. In this study we investigated the role of the small GTPase Rac in EGF-induced cell migration using an in vitro wound-healing assay. In mouse colonic epithelial (MCE) cell lines, EGF-stimulated wound closure was accompanied by a doubling of the number of cells containing lamellipodial extensions at the wound margin, increased Rac membrane translocation in cells at the wound margin, and rapid Rac activation. Either Rac1 small interfering (si)RNA or a Rac1 inhibitor completely blocked EGF-stimulated wound closure. Whereas EGF failed to activate Rac in colon cells from EGF receptor (EGFR) knockout mice, stable expression of wild-type EGFR restored EGF-stimulated Rac activation and migration. Pharmacological inhibition of either phosphatidylinositol 3-kinase (PI3K) or Src family kinases reduced EGF-stimulated Rac activation. Cotreatment of cells with both inhibitors completely blocked EGF-stimulated Rac activation and localization to the leading edge of cells and lamellipodial extension. Our results present a novel mechanism by which the PI3K and Src signaling cascades cooperate to activate Rac and promote intestinal epithelial cell migration downstream of EGFR.

  15. SynMuv genes redundantly inhibit lin-3/EGF expression to prevent inappropriate vulval induction in C. elegans.

    Science.gov (United States)

    Cui, Mingxue; Chen, Jun; Myers, Toshia R; Hwang, Byung Joon; Sternberg, Paul W; Greenwald, Iva; Han, Min

    2006-05-01

    Activation of EGFR-Ras-MAPK signaling in vulval precursor cells (VPCs) by LIN-3/EGF from the gonad induces vulval development in C. elegans. The prevailing view is that LIN-3 overcomes an "inhibitory signal" from the adjacent hyp7 hypodermal syncytium. This view originated from observations indicating that inactivation of functionally redundant Synthetic Multivulva (SynMuv) genes in hyp7 can activate EGFR-Ras-MAPK signaling in the VPCs. Many SynMuv genes encode transcription and chromatin-associated factors, including the Rb ortholog. Here, we show that the SynMuv A and SynMuv B gene classes are functionally redundant for transcriptional repression of the key target gene, lin-3/EGF, in the hypodermis. These observations necessitate a revision of the concept of "inhibitory signaling." They also underscore the importance of preventing inappropriate cell signaling during development and suggest that derepression of growth factors may be the mechanism by which tumor suppressor genes such as Rb can have cell nonautonomous effects.

  16. Bio-imaging of colorectal cancer models using near infrared labeled epidermal growth factor.

    Directory of Open Access Journals (Sweden)

    Gadi Cohen

    Full Text Available Novel strategies that target the epidermal growth factor receptor (EGFR have led to the clinical development of monoclonal antibodies, which treat metastatic colorectal cancer (mCRC but only subgroups of patients with increased wild type KRAS and EGFR gene copy, respond to these agents. Furthermore, resistance to EGFR blockade inevitably occurred, making future therapy difficult. Novel bio-imaging (BOI methods may assist in quantization of EGFR in mCRC tissue thus complementing the immunohistochemistry methodology, in guiding the future treatment of these patients. The aim of the present study was to explore the usefulness of near infrared-labeled EGF (EGF-NIR for bio-imaging of CRC using in vitro and in vivo orthotopic tumor CRC models and ex vivo human CRC tissues. We describe the preparation and characterization of EGF-NIR and investigate binding, using BOI of a panel of CRC cell culture models resembling heterogeneity of human CRC tissues. EGF-NIR was specifically and selectively bound by EGFR expressing CRC cells, the intensity of EGF-NIR signal to background ratio (SBR reflected EGFR levels, dose-response and time course imaging experiments provided optimal conditions for quantization of EGFR levels by BOI. EGF-NIR imaging of mice with HT-29 orthotopic CRC tumor indicated that EGF-NIR is more slowly cleared from the tumor and the highest SBR between tumor and normal adjacent tissue was achieved two days post-injection. Furthermore, images of dissected tissues demonstrated accumulation of EGF-NIR in the tumor and liver. EGF-NIR specifically and strongly labeled EGFR positive human CRC tissues while adjacent CRC tissue and EGFR negative tissues expressed weak NIR signals. This study emphasizes the use of EGF-NIR for preclinical studies. Combined with other methods, EGF-NIR could provide an additional bio-imaging specific tool in the standardization of measurements of EGFR expression in CRC tissues.

  17. Clinical significance of EGF and EGFR expression changes in cryptorchid boys

    Institute of Scientific and Technical Information of China (English)

    YangGS; LuRK

    2002-01-01

    Aim:To explore the changes of epidermal growth factor (EGF) and epidermal growth factor receptor(EGFR) expressions in cryptorchid children and their clinical significance.Methods:The level of serum EGF was measured by radioimmunoassay (RIA) and the expression of EGFR by immunohistochemistry.Results:(1)The level of serum EGF was significantly lower in cryptorchid children than in normal subjects at age group of 5-9 years (P<0.01) and 10-14 years (P<0.01),(2)The level of EGF was significantly lower in boys with impalpable testis than in those with extracanalicular and intracanalicular testes (P<0.01),(3)The serum EGF level increased significantly 6 months after orchiopexy(P<0.05),(4)The EGFR expression in testicular Leydig's cells was lower in 2-4 year-old boys than in those over 5 years(P<0.05) and (5)the EGFR expression was less positive in the impalpable group and the intracanalicular group than that of the extracanalicular group (P<0.01).Conclusion:The EGF and EGFR expressions may correlate with the age and the position of testes;orchiopexy improves the EGF and EGFR expressions in cryptorchid boys.

  18. Differential effects of EGF and amphiregulin on adhesion molecule expression and migration of colon carcinoma cells.

    Science.gov (United States)

    Solic, N; Davies, D E

    1997-08-01

    Epidermal growth factor (EGF) is a potent morphogen affecting cell shape and motility through regulation of adhesive interactions. We have characterized the morphological effects of EGF on GP2d and GP5d colon carcinoma cell lines and have compared the ability of the heparin-binding EGF receptor ligand amphiregulin (AR) to elicit the same effects. EGF induced a marked epithelial-mesenchymal transition in both cell lines. This effect was evident at 7 pM EGF and was associated with a reduction in cellular adherens junctions and diminished cell-cell contact; it was also associated with an increase in expression of alpha2-integrin as well as enhanced adhesion to the substratum and cell spreading. These changes in adhesion molecule expression were accompanied by enhanced migration on collagen. Blockade of cell growth with mitomycin C did not prevent the EGF-induced morphological change, showing that the mitogenic and morphogenic responses of the GP cells were separable. The phosphatidyl inositol (PI) 3-kinase inhibitor wortmannin inhibited basal proliferation but had no effect on the EGF-induced morphological change, further suggesting that the PI 3-kinase pathway was not involved in the morphogenic response of these cells. Amphiregulin stimulated proliferation of both cell lines, but could only elicit a modest morphological change if used at considerably higher doses or if growth was blocked with mitomycin C. In cells treated with 55 nM AR, alpha2-integrin expression was slightly increased; however, unlike the EGF case, adherens junctions remained intact. These differences in the ability of EGF and amphiregulin to affect cellular adhesion and migration may be significant factors influencing normal and tumor cell behavior.

  19. A Novel NHE1-Centered Signaling Cassette Drives Epidermal Growth Factor Receptor–Dependent Pancreatic Tumor Metastasis and Is a Target for Combination Therapy

    Directory of Open Access Journals (Sweden)

    Rosa Angela Cardone

    2015-02-01

    Full Text Available Pancreatic ductal adenocarcinoma (PDAC is one of the most lethal cancers principally because of early invasion and metastasis. The epidermal growth factor receptor (EGFR is essential for PDAC development even in the presence of Kras, but its inhibition with erlotinib gives only a modest clinical response, making the discovery of novel EGFR targets of critical interest. Here, we revealed by mining a human pancreatic gene expression database that the metastasis promoter Na+/H+ exchanger (NHE1 associates with the EGFR in PDAC. In human PDAC cell lines, we confirmed that NHE1 drives both basal and EGF-stimulated three-dimensional growth and early invasion via invadopodial extracellular matrix digestion. EGF promoted the complexing of EGFR with NHE1 via the scaffolding protein Na+/H+ exchanger regulatory factor 1, engaging EGFR in a negative transregulatory loop that controls the extent and duration of EGFR oncogenic signaling and stimulates NHE1. The specificity of NHE1 for growth or invasion depends on the segregation of the transient EGFR/Na+/H+ exchanger regulatory factor 1/NHE1 signaling complex into dimeric subcomplexes in different lipid raftlike membrane domains. This signaling complex was also found in tumors developed in orthotopic mice. Importantly, the specific NHE1 inhibitor cariporide reduced both three-dimensional growth and invasion independently of PDAC subtype and synergistically sensitized these behaviors to low doses of erlotinib.

  20. Unconventional EGF-induced ERK1/2-mediated Kv1.3 endocytosis.

    Science.gov (United States)

    Martínez-Mármol, Ramón; Comes, Núria; Styrczewska, Katarzyna; Pérez-Verdaguer, Mireia; Vicente, Rubén; Pujadas, Lluís; Soriano, Eduardo; Sorkin, Alexander; Felipe, Antonio

    2016-04-01

    The potassium channel Kv1.3 plays roles in immunity, neuronal development and sensory discrimination. Regulation of Kv1.3 by kinase signaling has been studied. In this context, EGF binds to specific receptors (EGFR) and triggers tyrosine kinase-dependent signaling, which down-regulates Kv1.3 currents. We show that Kv1.3 undergoes EGF-dependent endocytosis. This EGF-mediated mechanism is relevant because is involved in adult neural stem cell fate determination. We demonstrated that changes in Kv1.3 subcellular distribution upon EGFR activation were due to Kv1.3 clathrin-dependent endocytosis, which targets the Kv1.3 channels to the lysosomal degradative pathway. Interestingly, our results further revealed that relevant tyrosines and other interacting motifs, such as PDZ and SH3 domains, were not involved in the EGF-dependent Kv1.3 internalization. However, a new, and yet undescribed mechanism, of ERK1/2-mediated threonine phosphorylation is crucial for the EGF-mediated Kv1.3 endocytosis. Our results demonstrate that EGF triggers the down-regulation of Kv1.3 activity and its expression at the cell surface, which is important for the development and migration of adult neural progenitors.

  1. A novel signaling pathway of tissue kallikrein in promoting keratinocyte migration: Activation of proteinase-activated receptor 1 and epidermal growth factor receptor

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Lin; Chao, Lee [Department of Biochemistry and Molecular Biology, Medical University of South Carolina, 173 Ashley Avenue, Charleston, SC 29425-2211 (United States); Chao, Julie, E-mail: chaoj@musc.edu [Department of Biochemistry and Molecular Biology, Medical University of South Carolina, 173 Ashley Avenue, Charleston, SC 29425-2211 (United States)

    2010-02-01

    Biological functions of tissue kallikrein (TK, KLK1) are mainly mediated by kinin generation and subsequent kinin B2 receptor activation. In this study, we investigated the potential role of TK and its signaling pathways in cultured human keratinocyte migration and in a rat skin wound healing model. Herein, we show that TK promoted cell migration and proliferation in a concentration- and time-dependent manner. Inactive TK or kinin had no significant effect on cell migration. Interestingly, cell migration induced by active TK was not blocked by icatibant or L-NAME, indicating an event independent of kinin B2 receptor and nitric oxide formation. TK's stimulatory effect on cell migration was inhibited by small interfering RNA for proteinase-activated receptor 1 (PAR{sub 1}), and by PAR{sub 1} inhibitor. TK-induced migration was associated with increased phosphorylation of epidermal growth factor receptor (EGFR) and extracellular signal-regulated kinase (ERK), which was blocked by inhibition of protein kinase C (PKC), Src, EGFR and ERK. TK-induced cell migration and EGFR phosphorylation were blocked by metalloproteinase (MMP) inhibitor, heparin, and antibodies against EGFR external domain, heparin-binding EGF-like growth factor (HB-EGF) and amphiregulin (AR). Local application of TK promoted skin wound healing in rats, whereas icatibant and EGFR inhibitor blocked TK's effect. Skin wound healing was further delayed by aprotinin and neutralizing TK antibody. This study demonstrates a novel role of TK in skin wound healing and uncovers new signaling pathways mediated by TK in promoting keratinocyte migration through activation of the PAR{sub 1}-PKC-Src-MMP pathway and HB-EGF/AR shedding-dependent EGFR transactivation.

  2. Decellularized scaffolds containing hyaluronic acid and EGF for promoting the recovery of skin wounds.

    Science.gov (United States)

    Wu, Zhengzheng; Tang, Yan; Fang, Hongdou; Su, Zhongchun; Xu, Bin; Lin, Yongliang; Zhang, Peng; Wei, Xing

    2015-01-01

    There is no effective therapy for the treatment of deep and large area skin wounds. Decellularized scaffolds can be prepared from animal tissues and represent a promising biomaterial for investigation in tissue regeneration studies. In this study, MTT assay showed that epidermal growth factor (EGF) increased NIH3T3 cell proliferation in a bell-shaped dose response, and the maximum cell proliferation was achieved at a concentration of 25 ng/ml. Decellularized scaffolds were prepared from pig peritoneum by a series of physical and chemical treatments. Hyaluronic acid (HA) increased EGF adsorption to the scaffolds. Decellularized scaffolds containing HA sustained the release of EGF compared to no HA. Rabbits contain relatively large skin surface and are less expensive and easy to be taken care, so that a rabbit wound healing model was use in this study. Four full-thickness skin wounds were created in each rabbit for evaluation of the effects of the scaffolds on the skin regeneration. Wounds covered with scaffolds containing either 1 or 3 μg/ml EGF were significantly smaller than with vaseline oil gauzes or with scaffolds alone, and the wounds covered with scaffolds containing 1 μg/ml EGF recovered best among all four wounds. Hematoxylin-Eosin staining confirmed these results by demonstrating that significantly thicker dermis layers were also observed in the wounds covered by the decellularized scaffolds containing HA and either 1 or 3 μg/ml EGF than with vaseline oil gauzes or with scaffolds alone. In addition, the scaffolds containing HA and 1 μg/ml EGF gave thicker dermis layers than HA and 3 μg/ml EGF and showed the regeneration of skin appendages on day 28 post-transplantation. These results demonstrated that decellularized scaffolds containing HA and EGF could provide a promising way for the treatment of human skin injuries.

  3. The Membrane-anchoring Domain of Epidermal Growth Factor Receptor Ligands Dictates Their Ability to Operate in Juxtacrine Mode

    Energy Technology Data Exchange (ETDEWEB)

    Dong, Jianying; Opresko, Lee; Chrisler, William B.; Orr, Galya; Quesenberry, Ryan D.; Lauffenburger, Douglas A.; Wiley, H S.

    2005-06-01

    All ligands of the epidermal growth factor receptor (EGFR) are synthesized as membrane-anchored precursors. Previous work has suggested that some ligands, such as EGF, must be proteolytically released to be active, whereas others, such as heparin binding EGF-like growth factor (HB-EGF) can function while still anchored to the membrane (i.e., juxtacrine signaling). To explore the structural basis for these differences in ligand activity, we engineered a series of membrane-anchored ligands in which the core, receptor-binding domain of EGF was combined with different domains of both EGF and HB-EGF. We found that ligands having the N-terminal extension of EGF could not bind to the EGFR, even when released from the membrane. Ligands lacking an N-terminal extension, but possessing the membrane-anchoring domain of EGF still required proteolytic release for activity, whereas ligands with the membrane anchoring domain of HB-EGF could elicit full biological activity while still membrane anchored. Ligands containing the HB-EGF membrane anchor, but lacking an N-terminal extension, activated EGFR during their transit through the Golgi apparatus . However, cell-mixing experiments and fluorescence resonance energy transfer (FRET) studies showed that juxtacrine signaling typically occurred in trans at the cell surface, at points of cell-cell contact. Our data suggest that the membrane-anchoring domain of ligands selectively controls their ability to participate in juxtacrine signaling and thus, only a subclass of EGFR ligands can act in a juxtacrine mode.

  4. Amplification and overexpression of the EGF receptor gene in primary human glioblastomas.

    Science.gov (United States)

    Libermann, T A; Nusbaum, H R; Razon, N; Kris, R; Lax, I; Soreq, H; Whittle, N; Waterfield, M D; Ullrich, A; Schlessinger, J

    1985-01-01

    The expression of epidermal growth factor (EGF) receptor in brain tumours of glial origin was studied at the protein, mRNA and genomic levels. Four out of 10 glioblastomas that overexpress EGF receptor also have gene amplification. The amplified genes appear to be rearranged, generating an aberrant mRNA in at least one of these tumours. Such receptor defects may be relevant to tumorigenesis of human glioblastomas.

  5. Insulin induces a transcriptional activation of epiregulin, HB-EGF and amphiregulin, by a PI3K-dependent mechanism: identification of a specific insulin-responsive promoter element

    DEFF Research Database (Denmark)

    Ornskov, Dorthe; Nexo, Ebba; Sørensen, Boe Sandahl

    2007-01-01

    Previously we have shown that insulin-stimulation of RT4 bladder cancer cells leads to increased proliferation, which require HER1 activation, and is accompanied by increased mRNA expression of the EGF-ligands heparin-binding EGF-like growth factor (HB-EGF), amphiregulin (AR), and epiregulin (EPI...

  6. Interaction between PGE2 and EGF receptor through MAPKs in mouse embryonic stem cell proliferation.

    Science.gov (United States)

    Yun, S P; Lee, M Y; Ryu, J M; Han, H J

    2009-05-01

    Identifying the small molecules that permit precise regulation of embryonic stem (ES) cell proliferation should further support our understanding of the underlying molecular mechanisms of self renewal. In the present study, we showed that PGE(2) increased [(3)H]-thymidine incorporation in a time and dose dependent manner. In addition, PGE(2) increased the expression of cell cycle regulatory proteins, the percentage of cells in S phase and the total number of cells. PGE(2) obviously increased E-type prostaglandin (EP) receptor 1 mRNA expression level compare to 2, 3, 4 subtypes. EP1 antagonist also blocked PGE(2)-induced cell cycle regulatory protein expression and thymidine incorporation. PGE(2) caused phosphorylation of protein kinase C, Src, epidermal growth factor (EGF) receptor, phosphatidylinositol 3-kinase (PI3K)/Akt phosphorylation, and p44/42 mitogen-activated protein kinase (MAPK), which were blocked by each inhibitors. In conclusion, PGE(2)-stimulated proliferation is mediated by MAPK via EP1 receptor-dependent PKC and EGF receptor-dependent PI3K/Akt signaling pathways in mouse ES cells.

  7. Opposing roles of TGF-β and EGF in the regulation of TRAIL-induced apoptosis in human breast epithelial cells.

    Science.gov (United States)

    Cano-González, Ana; López-Rivas, Abelardo

    2016-08-01

    Transforming growth factor-beta (TGF-β) induces the epithelial to mesenchymal transition (EMT) in breast epithelial cells and plays an important role in mammary morphogenesis and breast cancer. In non-transformed breast epithelial cells TGF-β antagonizes epidermal growth factor (EGF) action and induces growth inhibition. Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) has been reported to participate in lumen formation during morphogenesis of human breast epithelial cells. Our previous work indicated that sensitivity of human breast epithelial cells to TRAIL can be modulated through the activation of the epidermal growth factor receptor-1 (EGFR). Here, we show that TGF-β opposes EGF-mediated sensitization to TRAIL-induced caspase-8 activation and apoptosis in non-transformed breast epithelial cells. Death-inducing signalling complex (DISC) formation by TRAIL was significantly reduced in cells treated with TGF-β. TGF-β treatment activates cytoprotective autophagy and down-regulates TRAIL-R2 expression at the cell surface by promoting the intracellular accumulation of this receptor. Lastly, we demonstrate that EMT is not involved in the inhibitory effect of TGF-β on apoptosis by TRAIL. Together, the data reveal a fine regulation by EGF and TGF-β of sensitivity of human breast epithelial cells to TRAIL which may be relevant during morphogenesis.

  8. Induction of PD-L1 expression by epidermal growth factor receptor–mediated signaling in esophageal squamous cell carcinoma

    Directory of Open Access Journals (Sweden)

    Zhang W

    2017-02-01

    Full Text Available Wencheng Zhang,1 Qingsong Pang,1 Cihui Yan,2 Qifeng Wang,3 Jingsong Yang,3 Shufei Yu,3 Xiao Liu,3 Zhiyong Yuan,1 Ping Wang,1 Zefen Xiao3 1Department of Radiation Oncology, 2Department of Immunology, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center of Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin, People’s Republic of China; 3Department of Radiation Oncology, Cancer Institute and Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People’s Republic of China Purpose: The purpose of this study was to investigate the potential effect of activation of epidermal growth factor receptor (EGFR signaling pathway on the expression of programmed death-ligand 1 (PD-L1 in esophageal squamous cell carcinoma (ESCC cells with EGFR overexpression. Methods: Flow cytometry and Western blot methods were used to assess PD-L1 expression on ESCC cells when EGFR signaling pathway was activated by epidermal growth factor (EGF with or without EGFR-specific inhibitor AG-1478, and then EGFR signaling array was applied to analyze the potential signaling pathways involved. Results: This study found that PD-L1 expression increased significantly in an EGFR-dependent manner by the activation of EGFR signaling and decreased sharply when EGFR signaling was blocked. The upregulated expression of PD-L1 was not associated with EGFR-STAT3 signaling pathway, but may be affected by EGFR–PI3K–AKT, EGFR–Ras–Raf–Erk, and EGR–PLC-γ signaling pathways. Conclusion: The expression of PD-L1 can be regulated by EGFR signaling activation in ESCC, which indicates an important role for EGFR-mediated immune escape and potential molecular pathways for EGFR-targeted therapy and immunotherapy. Keywords: epidermal growth factor receptor, programmed death-ligand 1, esophageal squamous cell carcinoma, immune checkpoint

  9. Relevance of LIF and EGF on Mouse Preimplantation Embryo Development

    Directory of Open Access Journals (Sweden)

    Iraj Amiri

    2008-01-01

    Full Text Available Objective: Recent evidence suggests that Leukemia Inhibitory Factor (LIF, a member ofinterleukin-6 family, has biological actions on preimplantation embryo development. Alsoit is established that Epidermal Growth Factor (EGF, a strong mitosis-promoting agent,improves the preimplantation embryo development by increasing the cell metabolism andproliferation. The purpose of the present study is to investigate the effects of these factors,alone and in combination together, on preimplantation and development of the embryo.Materials and Methods: Six to eight weeks old NMRI mice were super ovulated by injectionof 10IU PMSG and 10IU hCG, then the mated mice were killed 46 hours later. Theiroviducts were flushed, two-cell embryos collected and divided randomly to the four groupsas following: Control, treatment 1 (LIF, treatment 2 (EGF, treatment 3 (LIF+EGF. In eachgroup, the embryos were cultured in an incubator at 37°C with 5% CO2 and 90% humidityfor 72hrs. The state of embryo development was evaluated in 24,36,48,60 and 72hrsfollowing the embryos cultures. By the end of the cultures, cell apoptosis was studiedby the terminal deoxynucleotidyl transferas-mediated dUTP nick end-labeling (TUNELtechnique.Results: Significant difference was detected in the rate of hatching in the LIF and LIF+EGFgroups. This difference was also seen in the rate of blastocyst formation after 36hrs(p<0.05 and in the average of the total cell number (p<0.05 after 72hrs. In comparison tothe apoptotic index, there was no significant difference between the control and treatmentgroups.Conclusion: The findings in this study show a beneficial effect of LIF and EGF on theblastocyst formation, hatching and its total cell numbers in vitro.

  10. Epidermal growth-factor-induced transcript isoform variation drives mammary cell migration.

    Directory of Open Access Journals (Sweden)

    Wolfgang J Köstler

    Full Text Available Signal-induced transcript isoform variation (TIV includes alternative promoter usage as well as alternative splicing and alternative polyadenylation of mRNA. To assess the phenotypic relevance of signal-induced TIV, we employed exon arrays and breast epithelial cells, which migrate in response to the epidermal growth factor (EGF. We show that EGF rapidly--within one hour--induces widespread TIV in a significant fraction of the transcriptome. Importantly, TIV characterizes many genes that display no differential expression upon stimulus. In addition, similar EGF-dependent changes are shared by a panel of mammary cell lines. A functional screen, which utilized isoform-specific siRNA oligonucleotides, indicated that several isoforms play essential, non-redundant roles in EGF-induced mammary cell migration. Taken together, our findings highlight the importance of TIV in the rapid evolvement of a phenotypic response to extracellular signals.

  11. Synergistic Induction of Cyclooxygenase-2 by Transforming Growth Factor-β1 and Epidermal Growth Factor Inhibits Apoptosis in Epithelial Cells

    Directory of Open Access Journals (Sweden)

    Debabrata Saha

    1999-12-01

    Full Text Available Increased expression of cyclooxygenase-2 (COX-2 expression has been observed in several human tumor types and in selected animal and cell culture models of carcinogenesis, including lung cancer. Increased expression of COX-2 and production of prostaglandins appear to provide a survival advantage to transformed cells through the inhibition of apoptosis, increased attachment to extracellular matrix, increased invasiveness, the stimulation of angiogenesis. In the present studies, we found that transforming growth factor β1 (TGF-β1 and epidermal growth factor (EGF synergistically induced the expression of COX-2 and prostaglandin E2 (PGE2 production in mink lung epithelial (Mvi Lu cells. EGF, but not PDGF or IGF-1, was able to inhibit TGF-β1-induced apoptosis in Mvi Lu cells and this effect was blocked by NS-398, a selective inhibitor of COX-2 activity, suggesting a possible role for COX-2 in the anti-apoptosic effect of EGF receptor ligands. The combination of TGF-β1 and EGF also significantly induced COX-2 expression in rat intestinal epithelial (RIE-1 cells and completely prevented sodium butyrate (NaBu-induced apoptosis. The synergistic induction of COX-2 by TGF-β1 and EGF was not observed in R1B-L17 cells, a line derived from Mvi Lu cells that lacks the TGF-β type-I receptor. AG1478, a selective inhibitor of EGF receptor tyrosine kinase activity, completely suppressed the induction of COX-2 expression by either EGF or TGF-β1+EGF. Also, PD98059, a specific inhibitor of MEK/ERK pathway, SB203580, a specific inhibitor of p38 MAPK activity, significantly inhibited the induction of COX-2 in response to combined EGF and TGF-β1. These results suggest an important collaborative interaction of TGF-β1 and EGF signaling in the induction of COX-2 and prostaglandin production in Mv1Lu cells.

  12. Coacervate delivery of HB-EGF accelerates healing of type 2 diabetic wounds.

    Science.gov (United States)

    Johnson, Noah R; Wang, Yadong

    2015-01-01

    Chronic wounds such as diabetic ulcers pose a significant challenge as a number of underlying deficiencies prevent natural healing. In pursuit of a regenerative wound therapy, we developed a heparin-based coacervate delivery system that provides controlled release of heparin-binding epidermal growth factor (EGF)-like growth factor (HB-EGF) within the wound bed. In this study, we used a polygenic type 2 diabetic mouse model to evaluate the capacity of HB-EGF coacervate to overcome the deficiencies of diabetic wound healing. In full-thickness excisional wounds on NONcNZO10 diabetic mice, HB-EGF coacervate enhanced the proliferation and migration of epidermal keratinocytes, leading to accelerated epithelialization. Furthermore, increased collagen deposition within the wound bed led to faster wound contraction and greater wound vascularization. Additionally, in vitro assays demonstrated that HB-EGF released from the coacervate successfully increased migration of diabetic human keratinocytes. The multifunctional role of HB-EGF in the healing process and its enhanced efficacy when delivered by the coacervate make it a promising therapy for diabetic wounds.

  13. Analysis of transforming growth factorβ signaling in chronic rhinosinusitis

    Institute of Scientific and Technical Information of China (English)

    LI Yun-chuan; AN Yun-song; WANG Tong; ZANG Hong-rui

    2013-01-01

    Background It has been reported that there is a significant difference in the local tissue concentration of transforming growth factor (TGF)-β1 between chronic rhinosinusitis without nasal polyps (CRSsNP) and chronic rhinosinusitis without nasal polyps (CRSwNP) patients.TGF-β has been reported to play an important role in regulating epithelial cell repair in lower airway remodeling and may be a critical factor involved in the remodeling process of chronic rhinosinusitis (CRS).Methods Ethmoidal mucosal samples collected from CRS and healthy control patients were analyzed for TGF-β1,TGF-βreceptor Ⅰ,TGF-β receptor Ⅱ,Smad3,phospho-Smad3,Smad7,and Smad anchor for receptor activation by Western blotting analysis.The proliferation of sinonasal epithelial cells at baseline and after TGF-β and/or EGF stimulation was evaluated by the MTT assay.Results In CRSsNP,TGF-β1,TGF-β receptor Ⅰ,TGF-β receptor Ⅱ,and Smad3 protein levels were significantly higher than controls.In CRSwNP,TGF-β1,Smad3,and pSmad3 protein levels were significantly lower than controls.Smad7 protein was significantly higher in CRS than controls.In vitro experiments demonstrated that the baseline proliferation levels of sinonasal epithelial cells were lower in CRS than controls.Conclusions CRSwNP is characterized by a lower level of TGF-signaling compared with the control.In CRSsNP,although the upstream signaling of TGF-β was enhanced,the high Smad7 protein expression may restrain the downstream signaling components (e.g.,pSmad3) and the TGF-β antiproliferative effect on sinonasal epithelium.The difference in the local tissue concentration of TGF-β1 between CRSsNP and CRSwNP patients did not result in significant differences in epithelial proliferation.

  14. Fibroblast growth factor signaling in metabolic regulation

    Directory of Open Access Journals (Sweden)

    Vera eNies

    2016-01-01

    Full Text Available The prevalence of obesity is a growing health problem. Obesity is strongly associated with several comorbidities, such as non-alcoholic fatty liver disease, certain cancers, insulin resistance and type 2 diabetes, which all reduce life expectancy and life quality. Several drugs have been put forward in order to treat these diseases, but many of them have detrimental side effects. The unexpected role of the family of fibroblast growth factors in the regulation of energy metabolism provides new approaches to the treatment of metabolic diseases, and offers a valuable tool to gain more insight into metabolic regulation. The known beneficial effects of FGF19 and FGF21 on metabolism, together with recently discovered similar effects of FGF1 suggest that FGFs and their derivatives carry great potential as novel therapeutics to treat metabolic conditions. To facilitate the development of new therapies with improved targeting and minimal side effects, a better understanding of the molecular mechanism of action of FGFs is needed.In this review we will discuss what is currently known about the physiological roles of FGF signaling in tissues important for metabolic homeostasis. In addition, we will discuss current concepts regarding their pharmacological properties and effector tissues in the context of metabolic disease. Also the recent progress in the development of FGF variants will be reviewed. Our goal is to provide a comprehensive overview of the current concepts and consensuses regarding FGF signaling in metabolic health and disease, and to provide starting points for the development of FGF-based therapies against metabolic conditions.

  15. Comparing the epidermal growth factor interaction with four different cell lines: intriguing effects imply strong dependency of cellular context.

    Directory of Open Access Journals (Sweden)

    Hanna Björkelund

    Full Text Available The interaction of the epidermal growth factor (EGF with its receptor (EGFR is known to be complex, and the common over-expression of EGF receptor family members in a multitude of tumors makes it important to decipher this interaction and the following signaling pathways. We have investigated the affinity and kinetics of (125I-EGF binding to EGFR in four human tumor cell lines, each using four culturing conditions, in real time by use of LigandTracer®.Highly repeatable and precise measurements show that the overall apparent affinity of the (125I-EGF - EGFR interaction is greatly dependent on cell line at normal culturing conditions, ranging from K(D ≈ 200 pM on SKBR3 cells to K(D≈8 nM on A431 cells. The (125I-EGF - EGFR binding curves (irrespective of cell line have strong signs of multiple simultaneous interactions. Furthermore, for the cell lines A431 and SKOV3, gefitinib treatment increases the (125I-EGF - EGFR affinity, in particular when the cells are starved. The (125I-EGF - EGFR interaction on cell line U343 is sensitive to starvation while as on SKBR3 it is insensitive to gefitinib and starvation.The intriguing pattern of the binding characteristics proves that the cellular context is important when deciphering how EGF interacts with EGFR. From a general perspective, care is advisable when generalizing ligand-receptor interaction results across multiple cell-lines.

  16. Polyurethane foam containing rhEGF as a dressing material for healing diabetic wounds: Synthesis, characterization, in vitro and in vivo studies.

    Science.gov (United States)

    Pyun, Do Gi; Choi, Hyun Jun; Yoon, Hyoung Soon; Thambi, Thavasyappan; Lee, Doo Sung

    2015-11-01

    Diabetic wounds are a major health issue associated with diabetes mellitus. To surmount this issue, we developed polyurethane foams (PUFs) incorporating varying amounts of recombinant human epidermal growth factor (rhEGF) (rhEGF-PUFs) as a wound dressing for diabetic wounds. From electron microscopy images, it was found that the pore size of the rhEGF-PUFs surface (the wound contact layer) was less than 100μm, regardless of rhEGF content. The release of rhEGF from the PUFs was evaluated using an enzyme-linked immunosorbent assay. The result showed that the release of rhEGF was time and concentration dependent, i.e., the amount of released rhEGF significantly increased as the immersion time and the rhEGF content of the PUFs increased. In vitro cytotoxicity testing showed that rhEGF-PUFs increased the viability of HaCaT human keratinocytes and CCD986-sk human fibroblasts, which indicated that the incorporated rhEGF maintained its biological activity. In an in vitro scratch wound healing assay, the wound closure rate was faster in CCD986-sk human fibroblasts than in HaCaT human keratinocytes. Finally, the rhEGF-PUFs were evaluated as an in vivo treatment in a full-thickness wound model in diabetized Sprague-Dawley rats. The result indicated that compared with PUFs, rhEGF-PUFs accelerated wound healing by promoting wound contraction, re-epithelialization, collagen deposition and the formation of a skin appendage. These findings demonstrate that rhEGF-PUFs are a promising dressing for diabetic wounds.

  17. Calcium regulation of EGF-induced ERK5 activation: role of Lad1-MEKK2 interaction.

    Directory of Open Access Journals (Sweden)

    Zhong Yao

    Full Text Available The ERK5 cascade is a MAPK pathway that transmits both mitogenic and stress signals, yet its mechanism of activation is not fully understood. Using intracellular calcium modifiers, we found that ERK5 activation by EGF is inhibited both by the depletion and elevation of intracellular calcium levels. This calcium effect was found to occur upstream of MEKK2, which is the MAP3K of the ERK5 cascade. Co-immunoprecipitation revealed that EGF increases MEKK2 binding to the adaptor protein Lad1, and this interaction was reduced by the intracellular calcium modifiers, indicating that a proper calcium concentration is required for the interactions and transmission of EGF signals to ERK5. In vitro binding assays revealed that the proper calcium concentration is required for a direct binding of MEKK2 to Lad1. The binding of these proteins is not affected by c-Src-mediated phosphorylation on Lad1, but slightly affects the Tyr phosphorylation of MEKK2, suggesting that the interaction with Lad1 is necessary for full Tyr phosphorylation of MEKK2. In addition, we found that changes in calcium levels affect the EGF-induced nuclear translocation of MEKK2 and thereby its effect on the nuclear ERK5 activity. Taken together, these findings suggest that calcium is required for EGF-induced ERK5 activation, and this effect is probably mediated by securing proper interaction of MEKK2 with the upstream adaptor protein Lad1.

  18. Combined gene expression and proteomic analysis of EGF induced apoptosis in A431 cells suggests multiple pathways trigger apoptosis.

    Science.gov (United States)

    Alanazi, Ibrahim; Ebrahimie, Esmaeil; Hoffmann, Peter; Adelson, David L

    2013-11-01

    A431 cells, derived from epidermoid carcinoma, overexpress the epidermal growth factor receptor (EGFR) and when treated with a high dose of EGF will undergo apoptosis. We exploited microarray and proteomics techniques and network prediction to study the regulatory mechanisms of EGF-induced apoptosis in A431 cells. We observed significant changes in gene expression in 162 genes, approximately evenly split between pro-apoptotic and anti-apoptotic genes and identified 30 proteins from the proteomic data that had either pro or anti-apoptotic annotation. Our correlation analysis of gene expression and proteome modeled a number of distinct sub-networks that are associated with the onset of apoptosis, allowing us to identify specific pathways and components. These include components of the interferon signalling pathway, and down stream components, including cytokines and suppressors of cytokine signalling. A central component of almost all gene expression sub-networks identified was TP53, which is mutated in A431 cells, and was down regulated. This down regulation of TP53 appeared to be correlated with proteomic sub-networks of cytoskeletal or cell adhesion components that might induce apoptosis by triggering cytochrome C release. Of the only three genes also differentially expressed as proteins, only serpinb1 had a known association with apoptosis. We confirmed that up regulation and cleavage of serpinb1 into L-DNAaseII was correlated with the induction of apoptosis. It is unlikely that a single pathway, but more likely a combination of pathways is needed to trigger EGF induced apoptosis in A431cells.

  19. IL-17E synergizes with EGF and confers in vitro resistance to EGFR-targeted therapies in TNBC cells

    Science.gov (United States)

    Merrouche, Yacine; Fabre, Joseph; Cure, Herve; Garbar, Christian; Fuselier, Camille; Bastid, Jeremy; Antonicelli, Frank; Al-Daccak, Reem; Bensussan, Armand; Giustiniani, Jerome

    2016-01-01

    Estrogen receptor-, progesterone receptor- and HER2-negative breast cancers, also known as triple-negative breast cancers (TNBCs), have poor prognoses and are refractory to current therapeutic agents, including epidermal growth factor receptor (EGFR) inhibitors. Resistance to anti-EGFR therapeutic agents is often associated with sustained kinase phosphorylation, which promotes EGFR activation and translocation to the nucleus and prevents these agents from acting on their targets. The mechanisms underlying this resistance have not been fully elucidated. In addition, the IL-17E receptor is overexpressed in TNBC tumors and is associated with a poor prognosis. We have previously reported that IL-17E promotes TNBC resistance to anti-mitotic therapies. Here, we investigated whether IL-17E promotes TNBC resistance to anti-EGFR therapeutic agents by exploring the link between the IL-17E/IL-17E receptor axis and EGF signaling. We found that IL-17E, similarly to EGF, activates the EGFR in TNBC cells that are resistant to EGFR inhibitors. It also activates the PYK-2, Src and STAT3 kinases, which are essential for EGFR activation and nuclear translocation. IL-17E binds its specific receptor, IL-17RA/IL17RB, on these TNBC cells and synergizes with the EGF signaling pathway, thereby inducing Src-dependent EGFR transactivation and pSTAT3 and pEGFR translocation to the nucleus. Collectively, our data indicate that the IL-17E/IL-17E receptor axis may underlie TNBC resistance to EGFR inhibitors and suggest that inhibiting IL-17E or its receptor in combination with EGFR inhibitor administration may improve TNBC management. PMID:27462789

  20. Egf binding to its receptor triggers a rapid tyrosine phosphorylation of the erbB-2 protein in the mammary tumor cell line SK-BR-3.

    OpenAIRE

    King, C. R.; Borrello, I; Bellot, F; Comoglio, P; Schlessinger, J

    1988-01-01

    The epidermal growth factor receptor (EGF-R) and the erbB-2 proto-oncogene product protein are closely related by their structural homology and their shared enzymatic activity as autophosphorylating tyrosine kinases. We show that in mammary tumor cells (SK-BR-3) EGF causes a rapid increase in tyrosine phosphorylation of the erbB-2 protein. Phosphorylation of erbB-2 does not occur in cells lacking the EGF-R (MDA-MB-453). Phosphorylation of erbB-2 in SK-BR-3 cells is blocked if EGF is prevented...

  1. Basic mechanism leading to stimulation of glycogenolysis by isoproterenol, EGF, elevated extracellular K+ concentrations, or GABA.

    Science.gov (United States)

    Xu, Junnan; Song, Dan; Bai, Qiufang; Cai, Liping; Hertz, Leif; Peng, Liang

    2014-04-01

    Glycogenolysis, in brain parenchyma an astrocyte-specific process, has changed from being envisaged as an emergency procedure to playing central roles during brain response to whisker stimulation, memory formation, astrocytic K(+) uptake and stimulated release of ATP. It is activated by several transmitters and by even very small increases in extracellular K(+) concentration, and to be critically dependent upon an increase in free cytosolic Ca(2+) concentration ([Ca(2+)]i), whereas cAMP plays only a facilitatory role together with increased [Ca(2+)]i. Detailed knowledge about the signaling pathways eliciting glycogenolysis is therefore of interest and was investigated in the present study in well differentiated cultures of mouse astrocytes. The β-adrenergic agonist isoproterenol stimulated glycogenolysis by a β1-adrenergic effect, which initiated a pathway in which cAMP/protein kinase A activated a Gi/Gs shift, leading to Ca(2+)-activated glycogenolysis. Inhibition of this pathway downstream of cAMP but upstream of the Gi/Gs shift abolished the glycogenolysis. However, inhibitors operating downstream of the Ca(2+)-sensitive step, but preventing transactivation-mediated epidermal growth factor (EGF) receptor stimulation, a later step in the activated pathway, also caused inhibition of glycogenolysis. For this reason the effect of EGF was investigated and it was found to be glycogenolytic. Large increases in extracellular K(+) activated glycogenolysis by a nifedipine-inhibited L-channel opening allowing influx of Ca(2+), known to be glycogenolysis-dependent. Small increases (addition of 5 mM KCl) caused a smaller effect by a similarly glycogenolysis-reliant opening of an IP3 receptor-dependent ouabain signaling pathway. The same pathway could be activated by GABA (also in brain slices) due to its depolarizing effect in astrocytes.

  2. Both mitogen-activated protein kinase (MAPK)/extracellular-signal-regulated kinases (ERK) 1/2 and phosphatidylinositide-3-OH kinase (PI3K)/Akt pathways regulate activation of E-twenty-six (ETS)-like transcription factor 1 (Elk-1) in U138 glioblastoma cells.

    Science.gov (United States)

    Mut, Melike; Lule, Sevda; Demir, Ozlem; Kurnaz, Isil Aksan; Vural, Imran

    2012-02-01

    Epidermal growth factor (EGF) and its receptor (EGFR) have been shown to play a significant role in the pathogenesis of glioblastoma. In our study, the EGFR was stimulated with EGF in human U138 glioblastoma cells. We show that the activated mitogen-activated protein kinase (MAPK)/extracellular-signal-regulated kinases (ERK) 1/2 pathway phosphorylated the E twenty-six (ETS)-like transcription factor 1 (Elk-1) mainly at serine 383 residue. Mitogen-activated protein kinase kinase (MEK) 1/2 inhibitor, UO126 and ERK inhibitor II, FR180204 blocked the Elk-1 phosphorylation and activation. The phosphatidylinositide-3-OH kinase (PI3K)/Akt pathway was also involved in the Elk-1 activation. Activation of the Elk-1 led to an increased survival and a proliferative response with the EGF stimulation in the U138 glioblastoma cells. Knocking-down the Elk-1 using an RNA interference technique caused a decrease in survival of the unstimulated U138 glioblastoma cells and also decreased the proliferative response to the EGF stimulation. The Elk-1 transcription factor was important for the survival and proliferation of U138 glioblastoma cells upon the stimulation of EGFR with EGF. The MAPK/ERK1/2 and PI3K/Akt pathways regulated this response via activation of the Elk-1 transcription factor. The Elk-1 may be one of the convergence points for pathways located downstream of EGFR in glioblastoma cells. Utilization of the Elk-1 as a therapeutic target may lead to a novel strategy in treatment of glioblastoma.

  3. E2F1 transcription factor and its impact on growth factor and cytokine signaling.

    Science.gov (United States)

    Ertosun, Mustafa Gokhan; Hapil, Fatma Zehra; Osman Nidai, Ozes

    2016-10-01

    E2F1 is a transcription factor involved in cell cycle regulation and apoptosis. The transactivation capacity of E2F1 is regulated by pRb. In its hypophosphorylated form, pRb binds and inactivates DNA binding and transactivating functions of E2F1. The growth factor stimulation of cells leads to activation of CDKs (cyclin dependent kinases), which in turn phosphorylate Rb and hyperphosphorylated Rb is released from E2F1 or E2F1/DP complex, and free E2F1 can induce transcription of several genes involved in cell cycle entry, induction or inhibition of apoptosis. Thus, growth factors and cytokines generally utilize E2F1 to direct cells to either fate. Furthermore, E2F1 regulates expressions of various cytokines and growth factor receptors, establishing positive or negative feedback mechanisms. This review focuses on the relationship between E2F1 transcription factor and cytokines (IL-1, IL-2, IL-3, IL-6, TGF-beta, G-CSF, LIF), growth factors (EGF, KGF, VEGF, IGF, FGF, PDGF, HGF, NGF), and interferons (IFN-α, IFN-β and IFN-γ).

  4. Epidermal growth factor mediates detachment from and invasion through collagen I and Matrigel in Capan-1 pancreatic cancer cells

    Directory of Open Access Journals (Sweden)

    Kuver Rahul

    2005-03-01

    Full Text Available Abstract Background Pancreatic adenocarcinoma is a highly invasive neoplasm. Epidermal growth factor (EGF and its receptor are over expressed in pancreatic cancer, and expression correlates with invasion and metastasis. We hypothesized that EGF receptor and integrin signalling pathways interact in mediating cellular adhesion and invasion in pancreatic cancer, and that invasiveness correlates temporally with detachment from extracellular matrix. Methods We tested this hypothesis by investigating the role of EGF in mediating adhesion to and invasion through collagen I and Matrigel in the metastatic pancreatic adenocarcinoma cell line Capan-1. Adhesion and invasion were measured using in vitro assays of fluorescently-labeled cells. Adhesion and invasion assays were also performed in the primary pancreatic adenocarcinoma cell line MIA PaCa-2. Results EGF inhibited adhesion to collagen I and Matrigel in Capan-1 cells. The loss of adhesion was reversed by AG825, an inhibitor of erbB2 receptor signalling and by wortmannin, a PI3K inhibitor, but not by the protein synthesis inhibitor cycloheximide. EGF stimulated invasion through collagen I and Matrigel at concentrations and time courses similar to those mediating detachment from these extracellular matrix components. Adhesion to collagen I was different in MIA PaCa-2 cells, with no significant change elicited following EGF treatment, whereas treatment with the EGF family member heregulin-alpha elicited a marked increase in adhesion. Invasion through Matrigel in response to EGF, however, was similar to that observed in Capan-1 cells. Conclusion An inverse relationship exists between adhesion and invasion capabilities in Capan-1 cells but not in MIA PaCa-2 cells. EGF receptor signalling involving the erbB2 and PI3K pathways plays a role in mediating these events in Capan-1 cells.

  5. Wnt and EGF pathways act together to induce C. elegans male hook development.

    Science.gov (United States)

    Yu, Hui; Seah, Adeline; Herman, Michael A; Ferguson, Edwin L; Horvitz, H Robert; Sternberg, Paul W

    2009-03-15

    Comparative studies of vulva development between Caenorhabditis elegans and other nematode species have provided some insight into the evolution of patterning networks. However, molecular genetic details are available only in C. elegans and Pristionchus pacificus. To extend our knowledge on the evolution of patterning networks, we studied the C. elegans male hook competence group (HCG), an equivalence group that has similar developmental origins to the vulval precursor cells (VPCs), which generate the vulva in the hermaphrodite. Similar to VPC fate specification, each HCG cell adopts one of three fates (1 degree, 2 degrees, 3 degrees), and 2 degrees HCG fate specification is mediated by LIN-12/Notch. We show that 2 degrees HCG specification depends on the presence of a cell with the 1 degree fate. We also provide evidence that Wnt signaling via the Frizzled-like Wnt receptor LIN-17 acts to specify the 1 degree and 2 degrees HCG fate. A requirement for EGF signaling during 1 degree fate specification is seen only when LIN-17 activity is compromised. In addition, activation of the EGF pathway decreases dependence on LIN-17 and causes ectopic hook development. Our results suggest that WNT plays a more significant role than EGF signaling in specifying HCG fates, whereas in VPC specification EGF signaling is the major inductive signal. Nonetheless, the overall logic is similar in the VPCs and the HCG: EGF and/or WNT induce a 1 degree lineage, and LIN-12/NOTCH induces a 2 degrees lineage. Wnt signaling is also required for execution of the 1 degree and 2 degrees HCG lineages. lin-17 and bar-1/beta-catenin are preferentially expressed in the presumptive 1 degree cell P11.p. The dynamic subcellular localization of BAR-1-GFP in P11.p is concordant with the timing of HCG fate determination.

  6. EGF-induced EMT and invasiveness in serous borderline ovarian tumor cells: a possible step in the transition to low-grade serous carcinoma cells?

    Directory of Open Access Journals (Sweden)

    Jung-Chien Cheng

    Full Text Available In high-grade ovarian cancer cultures, it has been shown that epidermal growth factor (EGF induces cell invasion by activating an epithelial-mesenchymal transition (EMT. However, the effect of EGF on serous borderline ovarian tumors (SBOT and low-grade serous carcinomas (LGC cell invasion remains unknown. Here, we show that EGF receptor (EGFR was expressed, that EGF treatment increased cell migration and invasion in two cultured SBOT cell lines, SBOT3.1 and SV40 large T antigen-infected SBOT cells (SBOT4-LT, and in two cultured LGC cell lines, MPSC1 and SV40 LT/ST-immortalized LGC cells (ILGC. However, EGF induced down-regulation of E-cadherin and concurrent up-regulation of N-cadherin in SBOT cells but not in LGC cells. In SBOT cells, the expression of the transcriptional repressors of E-cadherin, Snail, Slug and ZEB1 were increased by EGF treatment. Treatment with EGF led to the activation of the downstream ERK1/2 and PI3K/Akt. The MEK1 inhibitor PD98059 diminished the EGF-induced cadherin switch and the up-regulation of Snail, Slug and ZEB1 and the EGF-mediated increase in SBOT cell migration and invasion. The PI3K inhibitor LY294002 had similar effects, but it could not block the EGF-induced up-regulation of N-cadherin and ZEB1. This study demonstrates that EGF induces SBOT cell migration and invasion by activating EMT, which involves the activation of the ERK1/2 and PI3K/Akt pathways and, subsequently, Snail, Slug and ZEB1 expression. Moreover, our results suggest that there are EMT-independent mechanisms that mediate the EGF-induced LGC cell migration and invasion.

  7. Regulation of the BMP Signaling-Responsive Transcriptional Network in the Drosophila Embryo.

    Science.gov (United States)

    Deignan, Lisa; Pinheiro, Marco T; Sutcliffe, Catherine; Saunders, Abbie; Wilcockson, Scott G; Zeef, Leo A H; Donaldson, Ian J; Ashe, Hilary L

    2016-07-01

    The BMP signaling pathway has a conserved role in dorsal-ventral axis patterning during embryonic development. In Drosophila, graded BMP signaling is transduced by the Mad transcription factor and opposed by the Brinker repressor. In this study, using the Drosophila embryo as a model, we combine RNA-seq with Mad and Brinker ChIP-seq to decipher the BMP-responsive transcriptional network underpinning differentiation of the dorsal ectoderm during dorsal-ventral axis patterning. We identify multiple new BMP target genes, including positive and negative regulators of EGF signaling. Manipulation of EGF signaling levels by loss- and gain-of-function studies reveals that EGF signaling negatively regulates embryonic BMP-responsive transcription. Therefore, the BMP gene network has a self-regulating property in that it establishes a balance between its activity and that of the antagonistic EGF signaling pathway to facilitate correct patterning. In terms of BMP-dependent transcription, we identify key roles for the Zelda and Zerknüllt transcription factors in establishing the resulting expression domain, and find widespread binding of insulator proteins to the Mad and Brinker-bound genomic regions. Analysis of embryos lacking the BEAF-32 insulator protein shows reduced transcription of a peak BMP target gene and a reduction in the number of amnioserosa cells, the fate specified by peak BMP signaling. We incorporate our findings into a model for Mad-dependent activation, and discuss its relevance to BMP signal interpretation in vertebrates.

  8. EGF stimulates IClswell by a redistribution of proteins involved in cell volume regulation.

    Science.gov (United States)

    Tamma, Grazia; Dossena, Silvia; Nofziger, Charity; Valenti, Giovanna; Svelto, Maria; Paulmichl, Markus

    2011-01-01

    ICln is a multifunctional protein involved in the generation of chloride currents activated during regulatory volume decrease (RVD) after cell swelling (ICl(swell)). Growth factor receptors play a key role in different cellular processes and epidermal growth factor (EGF) regulates swelling-activated chloride permeability. We set out to investigate if the EGF-induced upregulation of ICl(swell) could be explained by a rearrangement of ICln subcellular distribution and interaction with its molecular partners. NIH-3T3 fibroblasts were serum-deprived for 24 hours and stimulated with EGF (40 ng/ml) for 30 minutes. ICl(swell) activation, ICln distribution and interaction with its molecular partner HSPC038 were assessed by whole cell patch clamp and fluorescence resonance energy transfer (FRET). EGF treatment significantly enhanced the direct molecular interaction between ICln and HSPC038 and also resulted in an increase of ICln and HSPC038 association with the plasma membrane. Importantly, these events are associated with a significant increase of ICl(swell). The present data indicate that EGF might exert its role in the modulation of volume-sensitive chloride currents in part through activation and translocation of ICln and HSPC038 to the plasma membrane. Copyright © 2011 S. Karger AG, Basel.

  9. Serum EGF and NGF levels of patients with brain injury and limb fracture

    Institute of Scientific and Technical Information of China (English)

    Yan-Feng Zhuang; Jie Li

    2013-01-01

    Objective: To explore the expression and sign if icance of human epidermal growth factor (EGF) and nerve growth factor (NGF) in patients with knee osteoarthritis. Methods: RT-PCR and enzyme-linked immunosorbent assay were used to measure the serum EGF and NGF expression levels of patients with limb fracture and brain trauma injurry after 1 d, 3 d, 7 d, 14 d and the relationship between them was analyzed. The level was compared among the simple fracture group, traumatic brain injury group and the normal control group, with 40 cases in each group. Results: The serum NGF levels were significantly different among three groups. Serum NGF, EGF mRNA and protein levels gradually decreased with the increasing injury time in the limb fracture combined with brain injury group, traumatic brain injury group, the simple fracture group and the health control group (P<0.05). Conclusions: The serum of NGF, EGF levels significantly increased when limb fracture combined with brain injury, so EGF and NGF may be involved in the process of fracture healing.

  10. Mechanisms of EGF-induced stimulation of sodium reabsorption by alveolar epithelial cells.

    Science.gov (United States)

    Danto, S I; Borok, Z; Zhang, X L; Lopez, M Z; Patel, P; Crandall, E D; Lubman, R L

    1998-07-01

    We investigated the effects of epidermal growth factor (EGF) on active Na+ absorption by alveolar epithelium. Rat alveolar epithelial cells (AEC) were isolated and cultivated in serum-free medium on tissue culture-treated polycarbonate filters. mRNA for rat epithelial Na+ channel (rENaC) alpha-, beta-, and gamma-subunits and Na+ pump alpha1- and beta1-subunits were detected in day 4 monolayers by Northern analysis and were unchanged in abundance in day 5 monolayers in the absence of EGF. Monolayers cultivated in the presence of EGF (20 ng/ml) for 24 h from day 4 to day 5 showed an increase in both alpha1 and beta1 Na+ pump subunit mRNA but no increase in rENaC subunit mRNA. EGF-treated monolayers showed parallel increases in Na+ pump alpha1- and beta1-subunit protein by immunoblot relative to untreated monolayers. Fixed AEC monolayers demonstrated predominantly membrane-associated immunofluorescent labeling with anti-Na+ pump alpha1- and beta1-subunit antibodies, with increased intensity of cell labeling for both subunits seen at 24 h following exposure to EGF. These changes in Na+ pump mRNA and protein preceded a delayed (>12 h) increase in short-current circuit (measure of active transepithelial Na+ transport) across monolayers treated with EGF compared with untreated monolayers. We conclude that EGF increases active Na+ resorption across AEC monolayers primarily via direct effects on Na+ pump subunit mRNA expression and protein synthesis, leading to increased numbers of functional Na+ pumps in the basolateral membranes.

  11. The TRPM6/EGF pathway is downregulated in a rat model of cisplatin nephrotoxicity.

    Directory of Open Access Journals (Sweden)

    Kristien J Ledeganck

    Full Text Available Cisplatin-induced hypomagnesemia is described in humans and rats, but the underlying mechanisms are still unclear. Recent studies have shown that epidermal growth factor (EGF stimulates Mg(2+ re-absorption in the distal convoluted tubule via the Mg(2+ channel TRPM6. This study investigates the role of TRPM Mg(2+ channels, claudines, and EGF in the Mg(2+ homeostasis in a rat model of cisplatin-induced nephrotoxicity. Wistar rats were given 2.5 mg/kg cisplatin per week for 3 weeks and were euthanized 4 or 9 weeks after the first administration. The cisplatin treatment significantly increased the fractional excretion of Mg(2+. Real-time RT-PCR and/or Western blots were performed to assess the renal expression TRPM6, TRPM7, claudin-16, claudin-19, EGF, EGF receptor (EGFR and EGFR-pathway components. The renal mRNA expression of TRPM6 and EGF showed a significant decrease after cisplatin treatment, while the TRPM7, claudin-16 and EGFR expressions remained stable. The claudin-19 mRNA expression was significantly upregulated after cisplatin treatment. Western blotting confirmed the mRNA expression data for the claudins, but an showed upregulation of EGFR only at week 9. The role of the EGFR pathway, involving Pi3-AKT-Rac1, in cisplatin-induced nephropathy, could not be substantiated in further detail. This study shows that cisplatin treatment results in EGF and TRPM6 downregulation in the rat kidney, causing renal Mg(2+ loss. Our results are in line with the hypothesis that EGF influences the renal expression or activation of TRPM6 and plays a significant role in Mg(2+ loss in medication-induced nephropathy.

  12. EGF-induced apoptosis in A431 cells is dependent on STAT1, but not on STAT3.

    Science.gov (United States)

    Grudinkin, Pavel S; Zenin, Valery V; Kropotov, Andrey V; Dorosh, Viktoria N; Nikolsky, Nikolay N

    2007-10-01

    EGF in high concentrations has a growth-inhibitory effect on human epidermoid carcinoma cells A431. The transcription factor STAT1 is the most probable candidate for mediating this effect. In the present study, we demonstrated a strong reduction of the expression level of STAT1 in EGF-resistant sub-clones of A431 cells. EGF resistance was reversed by introducing wild-type STAT1, but not its Y701F mutant. Moreover, blocking the activity of Src family kinases reduced tyrosine phosphorylation of STAT1 and STAT3 and protected A431 cells from the EGF-induced growth inhibition. To further elucidate roles of STATs in A431 cell growth and survival, clones of A431 cells expressing short hairpin RNA (shRNA) against STAT1 or STAT3 were generated. Neither STAT1 nor STAT3 knockdown exerted any effect on growth rate or apoptotic death of A431 cells in the absence of EGF. However, upon EGF treatment A431 cells with knocked down STAT1 continued to grow and demonstrated a significantly lower level of apoptosis as compared to A431 cells. The knockdown of STAT3 did not alter cell growth or apoptosis. Taken together, our experiments prove the essential role of tyrosine phosphorylated STAT1, but not of STAT3, in EGF-induced apoptosis in A431 cells.

  13. Tunable signal processing through modular control of transcription factor translocation

    Science.gov (United States)

    Hao, Nan; Budnik, Bogdan A.; Gunawardena, Jeremy; O’Shea, Erin K.

    2013-01-01

    Signaling pathways can induce different dynamics of transcription factor (TF) activation. We explored how TFs process signaling inputs to generate diverse dynamic responses. The budding yeast general stress responsive TF Msn2 acted as a tunable signal processor that could track, filter, or integrate signals in an input dependent manner. This tunable signal processing appears to originate from dual regulation of both nuclear import and export by phosphorylation, as mutants with one form of regulation sustained only one signal processing function. Versatile signal processing by Msn2 is crucial for generating distinct dynamic responses to different natural stresses. Our findings reveal how complex signal processing functions are integrated into a single molecule and provide a guide for the design of TFs with “programmable” signal processing functions. PMID:23349292

  14. Tunable signal processing through modular control of transcription factor translocation.

    Science.gov (United States)

    Hao, Nan; Budnik, Bogdan A; Gunawardena, Jeremy; O'Shea, Erin K

    2013-01-25

    Signaling pathways can induce different dynamics of transcription factor (TF) activation. We explored how TFs process signaling inputs to generate diverse dynamic responses. The budding yeast general stress-responsive TF Msn2 acted as a tunable signal processor that could track, filter, or integrate signals in an input-dependent manner. This tunable signal processing appears to originate from dual regulation of both nuclear import and export by phosphorylation, as mutants with one form of regulation sustained only one signal-processing function. Versatile signal processing by Msn2 is crucial for generating distinct dynamic responses to different natural stresses. Our findings reveal how complex signal-processing functions are integrated into a single molecule and provide a guide for the design of TFs with "programmable" signal-processing functions.

  15. Mutant huntingtin regulates EGF receptor fate in non-neuronal cells lacking wild-type protein.

    Science.gov (United States)

    Melone, Mariarosa A B; Calarco, Anna; Petillo, Orsolina; Margarucci, Sabrina; Colucci-D'Amato, Luca; Galderisi, Umberto; Koverech, Guido; Peluso, Gianfranco

    2013-01-01

    Huntingtin (htt) is a scaffold protein localized at the subcellular level and is involved in coordinating the activity of several protein for signaling and intracellular transport. The emerging properties of htt in intracellular trafficking prompted us to study the role of mutant htt (polyQ-htt) in the intracellular fate of epidermal growth factor receptor (EGFR), whose activity seems to be strictly regulated by htt. In particular, to evaluate whether protein trafficking dysfunction occurs in non-neuronal cells in the absence of functional htt, we monitored the EGFR protein in fibroblasts from homozygotic HD patients and their healthy counterpart. We found that polyQ-htt controls EGFR degradation and recycling. Lack of wild-type htt caused alteration of the ubiquitination cycle, formation of EGFR-incorporating high-molecular weight protein aggregates and abnormal EGFR distribution in endosomes of the degradation and recycling pathways after EGF stimulation. PolyQ-htt-induced alteration of EGFR trafficking affected cell migration and proliferation, at least in part, through inhibition of ERK signaling. To our knowledge the data here reported represent the first signaling and phenotypic characterization of polyQ-htt involvement in the modulation of growth factor stimulation in non-neuronal cells.

  16. Cell Type-Specific Activation of AKT and ERK Signaling Pathways by Small Negatively-Charged Magnetic Nanoparticles

    Science.gov (United States)

    Rauch, Jens; Kolch, Walter; Mahmoudi, Morteza

    2012-11-01

    The interaction of nanoparticles (NPs) with living organisms has become a focus of public and scientific debate due to their potential wide applications in biomedicine, but also because of unwanted side effects. Here, we show that superparamagnetic iron oxide NPs (SPIONs) with different surface coatings can differentially affect signal transduction pathways. Using isogenic pairs of breast and colon derived cell lines we found that the stimulation of ERK and AKT signaling pathways by SPIONs is selectively dependent on the cell type and SPION type. In general, cells with Ras mutations respond better than their non-mutant counterparts. Small negatively charged SPIONs (snSPIONs) activated ERK to a similar extent as epidermal growth factor (EGF), and used the same upstream signaling components including activation of the EGF receptor. Importantly, snSPIONs stimulated the proliferation of Ras transformed breast epithelial cells as efficiently as EGF suggesting that NPs can mimic physiological growth factors.

  17. When EGF is offside, magnesium is wasted.

    Science.gov (United States)

    Muallem, Shmuel; Moe, Orson W

    2007-08-01

    Our understanding of magnesium (Mg(2+)) regulation has recently been catapulted forward by the discovery of several disease loci for monogenic disorders of Mg(2+) homeostasis. In this issue of the JCI, Groenestege et al. report that their study of a rare inherited Mg(2+) wasting disorder in consanguineous kindred shows that EGF acts as an autocrine/paracrine magnesiotropic hormone (see the related article beginning on page 2260). EGF stimulates Mg(2+) reabsorption in the renal distal convoluted tubule (DCT) via engagement of its receptor on the basolateral membrane of DCT cells and activation of the Mg(2+) channel TRPM6 (transient receptor potential cation channel, subfamily M, member 6) in the apical membrane. These authors show that a point mutation in pro-EGF retains EGF secretion to the apical but not the basolateral membrane, disrupting this cascade and causing renal Mg(2+) wasting. This work is another seminal example of the power of the study of monogenic disorders in the quest to understand human physiology.

  18. EGF Uptake and Degradation Assay to Determine the Effect of HTLV Regulatory Proteins on the ESCRT-Dependent MVB Pathway.

    Science.gov (United States)

    Murphy, Colin; Sheehy, Noreen

    2017-01-01

    The endosomal sorting complex required for transport (ESCRT) pathway plays key roles in multivesicular bodies (MVBs) formation and lysosomal degradation of membrane receptors, viral budding, and midbody abscission during cytokinesis. The epidermal growth factor receptor (EGFR) is regarded as a prototypical cargo of the MVB/ESCRT pathway and following stimulation by epidermal growth factor (EGF) EGFR/EGF complexes are internalized, sorted into MVBs, and degraded by lysosomes or recycled back to the cell membrane. Here, we describe an assay to analyze the effect of human T-cell leukemia (HTLV) regulatory proteins on the functionality of ESCRT-dependent MVB/lysosomal trafficking of EGFR/EGF complexes. This is performed by direct visualization and quantification of the rate of EGF-Alexa595/EGFR internalization and degradation in HeLa cells expressing HTLV regulatory proteins by immunofluorescence and western blot.

  19. Notch-mediated lateral inhibition regulates proneural wave propagation when combined with EGF-mediated reaction diffusion.

    Science.gov (United States)

    Sato, Makoto; Yasugi, Tetsuo; Minami, Yoshiaki; Miura, Takashi; Nagayama, Masaharu

    2016-08-30

    Notch-mediated lateral inhibition regulates binary cell fate choice, resulting in salt and pepper patterns during various developmental processes. However, how Notch signaling behaves in combination with other signaling systems remains elusive. The wave of differentiation in the Drosophila visual center or "proneural wave" accompanies Notch activity that is propagated without the formation of a salt and pepper pattern, implying that Notch does not form a feedback loop of lateral inhibition during this process. However, mathematical modeling and genetic analysis clearly showed that Notch-mediated lateral inhibition is implemented within the proneural wave. Because partial reduction in EGF signaling causes the formation of the salt and pepper pattern, it is most likely that EGF diffusion cancels salt and pepper pattern formation in silico and in vivo. Moreover, the combination of Notch-mediated lateral inhibition and EGF-mediated reaction diffusion enables a function of Notch signaling that regulates propagation of the wave of differentiation.

  20. 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

  1. Association between EGF +61A/G polymorphism and gastric cancer in Caucasians

    Institute of Scientific and Technical Information of China (English)

    Ana Paula Araújo; Bruno M Costa; Ana L Pinto-Correia; Maria Fragoso; Paula Ferreira; Mário Dinis-Ribeiro; Sandra Costa; Rui M Reis; Rui Medeiros

    2011-01-01

    AIM: To investigate the association between epidermal growth factor (EGF ) +61A/G polymorphism and susceptibility to gastric cancer, through a cross-sectional study. METHODS: Polymerase chain reaction resctriction fragment lenght polymorphism analyses were used to genotype EGF +61 in 207 patients with gastric lesions (162 patients with gastric adenocarcinomas, 45 with atrophy or intestinal metaplasia) and 984 controls. All subjects were Caucasian. RESULTS: Genotype distribution was 23.5% for GG and 76.5% for GA/AA in the control group, 18.4% for GG and 68.6% for GA/AA in the entire group with gastric lesions and 17.9% for GG and 82.1% for GA/AA in the group with gastric adenocarcinoma. No statistically significant associations were found between EGF +61 variants and risk for developing gastric cancer [odds ratios (OR) = 1.41, 95% confidence intervals (CI): 0.90-2.21, P = 0.116]. However, the stratification of individuals by gender revealed that males carrying A alleles (EGF +61A/G or AA) had an increased risk for developing gastric cancer as compared to GG homozygous males (OR = 1.55, 95% CI: 1.05-2.28, P = 0.021). CONCLUSION: In summary, we found that males who were A carriers for EGF +61 had an increased risk for developing gastric cancer. This result may be explained by the suggestion that women secrete less gastric acid than men.

  2. Albumin-stimulated DNA synthesis is mediated by Ca2+/PKC as well as EGF receptor-dependent p44/42 MAPK and NF-kappaB signal pathways in renal proximal tubule cells.

    Science.gov (United States)

    Lee, Yu Jin; Han, Ho Jae

    2008-03-01

    It is now recognized that significant tubular reabsorption of albumin occurs under physiological conditions that may play an important role in maintaining proximal tubular integrity and function. Therefore, this study examined the effect of bovine serum albumin (BSA) on DNA synthesis and its related signal molecules in primary cultured rabbit renal proximal tubule cells (PTCs). BSA increased the level of [(3)H]thymidine incorporation in a dose (> or =3 mg/ml)- and time (> or =3 h)-dependent manner, intracellular Ca(2+) concentration, and the level of protein kinase C (PKC) phosphorylation and stimulated the phosphorylation of the epidermal growth factor receptor (EGFR), which was inhibited by EGTA (extracellular Ca(2+) chelator), 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid acetoxymethyl ester (BAPTA-AM, intracellular Ca(2+) chelator), or PKC inhibitors (staurosporine or bisindolylmaleimide I). In addition, the PKC inhibitors or an EGFR inhibitor (AG-1478) blocked the BSA-induced phosphorylation of p44/42 mitogen-activated protein kinases (MAPKs). BSA also increased the level of nuclear factor-kappaB (NF-kappaB) and inhibitor of NF-kappaB (IkappaB) phosphorylation, which was blocked by staurosporine, AG-1478, or PD-98059 (p44/42 MAPK inhibitor). Inhibition of Ca(2+), PKC, EGFR, p44/42 MAPK, or NF-kappaB signal pathways blocked the BSA-induced incorporation of [(3)H]thymidine. Consequently, the inhibition of Ca(2+), PKC, EGFR, p44/42 MAPKs, or NF-kappaB blocked the BSA-induced increases in cyclin D1, cyclin-dependent kinase (CDK)4, cyclin E, or CDK2 and restored the BSA-induced inhibition of p21(WAF/Cip1) and p27(Kip1) expression. In conclusion, BSA stimulates DNA synthesis that is mediated by Ca(2+)/PKC as well as the EGFR-dependent p44/42 MAPK and NF-kappaB signal pathways in PTCs.

  3. Ultrastructure of Sheep Primordial Follicles Cultured in the Presence of Indol Acetic Acid, EGF, and FSH

    Directory of Open Access Journals (Sweden)

    Evelyn Rabelo Andrade

    2011-01-01

    Full Text Available The aim of this study was to investigate the ultrastructural characteristics of primordial follicles after culturing of sheep ovarian cortical slices in the presence of indol acetic acid (IAA, Epidermal Growth Factor (EGF, and FSH. To evaluate ultrastructure of primordial follicles cultured in MEM (control or in MEM containing IAA, EGF, and FSH, fragments of cultured tissue were processes for transmission electron microscopy. Except in the control, primordial follicles cultured in supplemented media for 6 d were ultrastructurally normal. They had oocyte with intact nucleus and the cytoplasm contained heterogeneous-sized lipid droplets and numerous round or elongated mitochondria with intact parallel cristae were observed. Rough endoplasmic reticulum (RER was rarely found. The granulosa cells cytoplasm contained a great number of mitochondria and abundant RER. In conclusion, the presence of IAA, EGF, and FSH helped to maintain ultrastructural integrity of sheep primordial follicles cultured in vitro.

  4. Effect of EGF on initiation of primordial follicle growth in ovary of newborn rat

    Institute of Scientific and Technical Information of China (English)

    柳海珍; 许复华; 刘以训

    2000-01-01

    The present study was designed to look at the effect of epidermal growth factor (EGF) and tomcie-stimulating hormone (FSH) on initiation of primordial follicle growth and differentiation in the ovary of newborn rat with a sensitive marker of proliferating cell nuclear antigen (PCNA). The results showed that more cuboidal granulosa cells (GC) were found in the ovary two days after injection of EGF. More proliferative GC were observed on D4. No such action of FSH on primordial follicles was demonstrated. Using in situ hybridization, inhibin a mRNA expression in GC was detected from D5, while FSH receptor (FSHR) mRNA expression started from D6 after birth. Both mRNAs increased following further development of the follicles. These results suggest that it is EGF, but not FSH, that may play a certain role in initiation of primordial follicle growth. FSH may be involved in further differentiation and growth of the early developmental follicles.

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

    Directory of Open Access Journals (Sweden)

    Andrzej Kemona

    2010-02-01

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

  6. The role of tyrosine kinase Etk/Bmx in EGF-induced apoptosis of MDA-MB-468 breast cancer cells.

    Science.gov (United States)

    Chen, Kai-Yun; Huang, Li-Ming; Kung, Hsing-Jien; Ann, David K; Shih, Hsiu-Ming

    2004-03-11

    Etk/Bmx, a member of the Tec family of tyrosine kinases, mediates various signaling pathways and confers several cellular functions. In the present study, we have explored the functional role of Etk in mediating EGF-induced apoptosis, using MDA-MB-468 cell line as a model. We first demonstrated that EGF treatment induces Etk tyrosine phosphorylation in both HeLa and MDA-MB-468 cells. Overexpression of Etk by recombinant adenovirus in MDA-MB-468 cells potentiates the extent of EGF-induced cell apoptosis. The observed Etk-enhanced MDA-MB-468 cell apoptosis is associated with the Stat1 activation, as demonstrated by electrophoresis mobility shift assays and reporter gene assays. By contrast, a kinase domain deletion mutant EtkDeltaK, functioning as a dominant-negative mutant, ameliorates EGF-induced Stat1 activation and apoptosis in MDA-MB-468 cells. To explore whether the activated Etk alone is sufficient for inducing apoptosis, a conditionally activated Etk (DeltaEtk-ER), a chimeric fusion protein of PH domain-truncated Etk and ligand-binding domain of estrogen receptor, was introduced into MDA-MB-468 cells. Upon beta-estradiol ligand activation, the DeltaEtk-ER could stimulate Stat1 activity and confer cell apoptosis independent of EGF treatment. Taken together, our findings indicate that Etk is a downstream signaling molecule of EGF receptor and suggest that Etk activation is essential for transducing the EGF-induced apoptotic signaling.

  7. An immunologic approach to induction of epidermal growth factor deficiency

    DEFF Research Database (Denmark)

    Raaberg, Lasse; Nexø, Ebba; Poulsen, Steen Seier;

    1995-01-01

    Epidermal growth factor (EGF) in pharmacologic doses is able to induce growth and development in the fetus and the newborn. To investigate the opposite situation, the effects of insufficient amounts of EGF during development, we wanted to establish an in vivo model with a state of EGF deficiency......(-9) mol/L. The antibodies recognized purified EGF from the submandibular glands (6 kD) and from urine (45 kD) and further native EGF in saliva and urine. The cross-reactivity toward transforming growth factor-alpha was below 3%. Binding of EGF by antibodies inhibited its binding to the EGF...

  8. Cutaneous consequences of inhibiting EGF receptor signaling in vivo: normal hair follicle development, but retarded hair cycle induction and inhibition of adipocyte growth in Egfr(Wa5) mice.

    Science.gov (United States)

    Sugawara, Koji; Schneider, Marlon R; Dahlhoff, Maik; Kloepper, Jennifer E; Paus, Ralf

    2010-03-01

    The epidermal growth factor receptor (EGFR) network is essential for proper development and homeostasis of skin and hair. However, detailed dissection of the role of the EGFR in hair follicle development and cycling have been impaired by the early mortality of EGFR knockout mice. We have studied in Waved-5 mice carrying an antimorphic EGFR allele (Egfr(wa5)), whose product acts as a dominant-negative receptor, whether strongly reduced EGFR signaling impacts on the hair and skin phenotype. Histomorphometry and immunohistochemistry were employed to study hair follicle morphogenesis stages and cycle induction in Waved-5 mice and control littermates during embryonic development and postnatal life. By routine histology and quantitative histomorphometry, no significant abnormalities in the epidermis and in hair follicle morphogenesis were detected, while the initiation of hair follicle cycling was slightly, but significantly retarded. Proliferation and apoptosis of epidermal and hair matrix keratinocytes of Waved-5 mice appeared unaltered. Intriguingly, the thickness of the subcutis and the percentage of proliferating subcutaneous adipocytes were significantly reduced in Waved-5 mice around days P8.5 to P10.5. Although no differences in total body weight gain could be detected, Wa5 mice showed a significant reduction in the percentage of body fat at P8.5. Our results suggest the presence of effective compensatory mechanisms in murine skin in vivo that ensure nearly normal epidermal and hair follicle keratinocyte function despite very low levels of EGFR-mediated signaling. Our unexpected findings of transiently reduced subcutaneous adipose tissue indicate a role for the EGFR in regulating subcutaneous fat. 2009 Japanese Society for Investigative Dermatology. Published by Elsevier Ireland Ltd. All rights reserved.

  9. [177Lu]Bz-DTPA-EGF: Preclinical characterization of a potential radionuclide targeting agent against glioma.

    Science.gov (United States)

    Sundberg, Asa Liljegren; Gedda, Lars; Orlova, Anna; Bruskin, Alexander; Blomquist, Erik; Carlsson, Jörgen; Tolmachev, Vladimir

    2004-04-01

    Patients with glioblastoma multiforme have a poor prognosis due to recurrences originating from spread cells. The use of radionuclide targeting might increase the chance of inactivating single tumor cells with minimal damage to surrounding healthy tissue. As a target, overexpressed epidermal growth factor receptors (EGFR) may be used. A natural ligand to EGFR, the epidermal growth factor (EGF) is an attractive targeting agent due to its low molecular weight (6 kDa) and high affinity for EGFR. 177Lu (T(1/2) = 6.7 days) is a radionuclide well suited for treatment of small tumor cell clusters, since it emits relatively low-energy beta particles. The goal of this study was to prepare and preclinically evaluate both in vitro and in vivo the [177Lu]Bz-DTPA-EGF conjugate. The conjugate was characterized in vitro for its cell-binding properties, and in vivo for its pharmacokinetics and ability to target EGFR. [177Lu]Bz-DTPA-EGF bound to cultured U343 glioblastoma cells with an affinity of 1.9 nM. Interaction with EGFR led to rapid internalization, and more than 70% of the cell-associated radioactivity was internalized after 30 minutes of incubation. The retention of radioactivity was good, with more than 65% of the 177Lu still cell-associated after 2 days. Biodistribution studies of i.v. injected [177Lu]Bz-DTPA-EGF in NMRI mice demonstrated a rapid blood clearance. Most of the radioactivity was found in the liver and kidneys. The liver uptake was receptor-mediated, since it could be significantly reduced by preinjection of unlabeled EGF. In conclusion, [177Lu]Bz-DTPA-EGF seems to be a promising candidate for locoregional treatment of glioblastoma due to its high binding affinity, low molecular weight, and ability to target EGFR in vivo.

  10. ANTIPROLIFERATIVE ACTIVITY OF HUMAN IFN-γ-EGF3 FUSION PROTEIN ARE RELATED TO ITS EGF RECEPTOR COMPETITION

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    The relationship between antiproliferative effect of human IFN-γ-EGF3 fusion protein and the influence of EGF receptor binding activity has been studied on A431 cell line. Antiproliferative activity of human IFN-γ-EGF3 was higher than that of its parent IFN-γ. In the 125 I-EGF receptor competition experiment, the inhibition of EGF receptor binding capacity on the target cells was observed in the treatments of human IFN-γ or IFN-γ-EGF3, but the later was more significant. Our data suggests that the antiproliferative effects by IFN-γ and its fusion protein are closely related to their EGF receptor competitions.

  11. HB-EGF-Promoted Airway Smooth Muscle Cells and Their Progenitor Migration Contribute to Airway Smooth Muscle Remodeling in Asthmatic Mouse.

    Science.gov (United States)

    Wang, Qing; Li, Hequan; Yao, Yinan; Lu, Guohua; Wang, Yuehong; Xia, Dajing; Zhou, Jianying

    2016-03-01

    The airway smooth muscle (ASM) cells' proliferation, migration, and their progenitor's migration are currently regarded as causative factors for ASM remodeling in asthma. Heparin-binding epidermal growth factor (HB-EGF), a potent mitogen and chemotactic factor, could promote ASM cell proliferation through MAPK pathways. In this study, we obtained primary ASM cells and their progenitors from C57BL/6 mice and went on to explore the role of HB-EGF in these cells migration and the underlying mechanisms. We found that recombinant HB-EGF (rHB-EGF) intratracheal instillation accelerated ASM layer thickening in an OVA-induced asthmatic mouse. Modified Boyden chamber assay revealed that rHB-EGF facilitate ASM cell migration in a dose-dependent manner and ASM cells from asthmatic mice had a greater migration ability than that from normal counterparts. rHB-EGF could stimulate the phosphorylation of ERK1/2 and p38 in ASM cells but further migration assay showed that only epidermal growth factor receptor inhibitor (AG1478) or p38 inhibitor (SB203580), but not ERK1/2 inhibitor (PD98059), could inhibit rHB-EGF-mediated ASM cells migration. Actin cytoskeleton experiments exhibited that rHB-EGF could cause actin stress fibers disassembly and focal adhesions formation of ASM cells through the activation of p38. Finally, airway instillation of rHB-EGF promoted the recruitment of bone marrow-derived smooth muscle progenitor cells, which were transferred via caudal vein, migrating into the airway from the circulation. These observations demonstrated that ASM remodeling in asthma might have resulted from HB-EGF-mediated ASM cells and their progenitor cells migration, via p38 MAPK-dependent actin cytoskeleton remodeling.

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

    Directory of Open Access Journals (Sweden)

    Bruno Pereira Carreira

    2014-10-01

    Full Text Available 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 (NSC, and explored possible mechanisms underlying this effect. We investigated which mechanisms are involved in the regulation of NSC proliferation following treatment with an inflammatory stimulus (LPS plus IFN-γ, using a culture system of subventricular zone (SVZ-derived NSC mixed with microglia cells obtained from wild-type mice (iNOS+/+ or from iNOS knockout mice (iNOS-/-. We found an impairment of NSC cell proliferation in iNOS+/+ mixed cultures, which was not observed in iNOS-/- mixed cultures. Furthermore, the increased release of NO by activated iNOS+/+ microglial cells decreased the activation of the ERK/MAPK signaling pathway, which was concomitant with an enhanced nitration of the EGF receptor. Preventing nitrogen reactive species formation with MnTBAP, a scavenger of peroxynitrite, or using the peroxynitrite degradation catalyst FeTMPyP, cell proliferation and ERK signaling were restored to basal levels in iNOS+/+ mixed cultures. Moreover, exposure to the NO donor NOC-18 (100 µM, for 48 h, inhibited SVZ-derived NSC proliferation. Regarding the antiproliferative effect of NO, we found that NOC-18 caused the impairment of signaling through the ERK/MAPK pathway, which may be related to increased nitration of the EGF receptor in NSC. Using MnTBAP nitration was prevented, maintaining ERK signaling, rescuing NSC proliferation. We show that NO from inflammatory origin leads to a decreased function of the EGF receptor, which compromised proliferation of NSC. We also demonstrated that NO-mediated nitration of the EGF receptor caused a decrease in its phosphorylation, thus preventing regular proliferation signaling through the

  13. Molecular mechanism of signaling by tumor necrosis factor

    Institute of Scientific and Technical Information of China (English)

    ZHA; Jikun(查纪坤); SHU; Hongbing(舒红兵)

    2002-01-01

    Tumor necrosis factor (TNF) is an important cytokine with multiple biological effects,including cell growth,differentiation,apoptosis,immune regulation and induction of inflammation. The effects of TNF are mediated by two receptors,TNF-R1 and TNF-R2. The major signal transduction pathways triggered by TNF include those that lead to apoptosis,activation of transcription factor NF-??B and protein kinase JNK. This review will discuss the molecular mechanisms of these signaling pathways.

  14. Combined effect of gefitinib ('Iressa', ZD1839) and targeted radiotherapy with {sup 211}At-EGF

    Energy Technology Data Exchange (ETDEWEB)

    Sundberg, Aasa Liljegren; Orlova, Anna; Gedda, Lars; Tolmachev, Vladimir; Carlsson, Joergen [Division of Biomedical Radiation Sciences, Rudbeck Laboratory, Uppsala University, 751 85, Uppsala (Sweden); Almqvist, Ylva [Division of Radiology, Uppsala University, Uppsala (Sweden); Blomquist, Erik [Division of Oncology, Uppsala University, Uppsala (Sweden); Jensen, Holger J. [Department of Clinical Physiology and Nuclear Medicine, PET and Cyclotron Unit, Rigshospitalet, Copenhagen (Denmark)

    2003-10-01

    The EGFR-TKI (epidermal growth factor receptor tyrosine kinase inhibitor) gefitinib ['Iressa' (trademark of the AstraZeneca group of companies), ZD1839] increases the cellular uptake of radiolabelled epidermal growth factor (EGF). We investigated gefitinib treatment combined with astatine-211 EGF targeting in vitro using two cell lines expressing high levels of EGFR: A431 (sensitive to gefitinib) and U343MGaCl2:1 (resistant to gefitinib). In both cell lines, the uptake of {sup 211}At-EGF was markedly increased by concomitant treatment with gefitinib. Survival was investigated using both a clonogenic survival assay and a cell growth assay. Combined gefitinib and {sup 211}At-EGF treatment reduced the survival of U343 cells 3.5-fold compared with {sup 211}At-EGF alone. In A431 cells, {sup 211}At-EGF treatment resulted in very low survival, but combined treatment with gefitinib increased the survival by about 20-fold. These results indicate that combined treatment with gefitinib might increase the effect of ligand-mediated radionuclide therapy in gefitinib-resistant tumours and decrease the effect of such therapy in gefitinib-sensitive tumours. (orig.)

  15. Ultrastructure of sheep primordial follicles cultured in the presence of indol acetic acid, EGF, and FSH

    DEFF Research Database (Denmark)

    Andrade, Evelyn Rabelo; Hyttel, Poul; Landim-Alvarenga, Fernanda Da Cruz;

    2011-01-01

    The aim of this study was to investigate the ultrastructural characteristics of primordial follicles after culturing of sheep ovarian cortical slices in the presence of indol acetic acid (IAA), Epidermal Growth Factor (EGF), and FSH. To evaluate ultrastructure of primordial follicles cultured...

  16. Association of EGF and LDL receptors with the cytoskeleton of cultured keratinocytes

    NARCIS (Netherlands)

    Pas, M.F.W. te; Ponec, M.; Bergen Henegouwen, P.M.P. van; Lombardi, P.; Havekes, L.M.; Boonstra, J.

    1990-01-01

    In this paper we demonstrate that isolated cytoskeletons of normal keratinocytes cultured under differentiation inducing conditions exhibit a high level of epidermal growth factor (EGF) binding. This binding is approximately 300% higher than the binding of intact cells. In contrast, various squamous

  17. Epidermal Growth Factor and Estrogen Act by Independent Pathways to Additively Promote the Release of the Angiogenic Chemokine CXCL8 by Breast Tumor Cells

    Directory of Open Access Journals (Sweden)

    Karin Haim

    2011-03-01

    Full Text Available The tumor microenvironment contains multiple cancer-supporting factors, whose joint activities promote malignancy. Here, we show that epidermal growth factor (EGF and estrogen upregulate in an additive manner the transcription and the secretion of the angiogenic chemokine CXCL8 (interleukin 8 [IL-8] in breast tumor cells. In view of published findings on cross-regulatory interactions between EGF receptors and estrogen receptors in breast tumor cells, we asked whether the additive effects of EGF and estrogen were due to their ability to (1 induce intracellular cross talk and amplify shared regulatory pathways or (2 act in independent mechanisms, which complement each other. We found that stimulation by EGF alone induced the release of CXCL8 through signaling pathways involving ErbB2, ErbB1, Erk, and phosphoinositide 3-kinase (PI3K. ErbB2 and Erk were also involved in estrogen activities on CXCL8 but to a lower extent than with EGF. However, in the joint stimulatory setup, the addition of estrogen to EGF has led to partial (ErbB2, ErbB1, Erk or complete (PI3K shutoff of the involvement of these activation pathways in CXCL8 up-regulation. Furthermore, when costimulation by EGF + estrogen was applied, the effects of estrogen were channeled to regulation of CXCL8 at the transcription level, acting through the transcription factor estrogen receptor α (ERα. In parallel, in the joint stimulation, EGF acted independently at the transcription level through AP-1, to upregulate CXCL8 expression. The independent activities of EGF and estrogen on CXCL8 transcription reinforce the need to introduce simultaneous targeting of ErbBs and ERα to achieve effective therapy in breast cancer.

  18. Toxicity and therapy of cisplatin-loaded EGF modified mPEG-PLGA-PLL nanoparticles for SKOV3 cancer in mice.

    Science.gov (United States)

    Wang, Yunfei; Liu, Peifeng; Qiu, Lihua; Sun, Ying; Zhu, Mingjie; Gu, Liying; Di, Wen; Duan, Yourong

    2013-05-01

    Construction on the nanoparticles with lower toxicity and specific tumor targeting properties is challenging and requires careful design of composition, size, physicochemical properties tailored for the nanoparticles. Here the epidermal growth factor (EGF) modified methoxy polyethylene glycol-polylactic-co-glycolic acid-polylysine (mPEG-PLGA-PLL) encapsulated cisplatin (CDDP) nanoparticles (CDDP-NPs-EGF) was prepared to for solving the toxicity of CDDP and improving therapeutic efficiency. The remarkable features of CDDP-NPs-EGF are increasing cytotoxicity that attribute to effective cell cycle arrest and high cell apoptosis in vitro. In vivo, the CDDP-NPs-EGF change drug distribution, decrease the nephrotoxicity of CDDP and improve significantly therapeutic efficiency without inducing obvious system toxicity, verifying its key role of the CDDP-NPs-EGF in lowering drug toxicity and enhancing the antitumor efficiency for SKOV3 cancer in mice. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

  19. Dynamic recruitment of protein tyrosine phosphatase PTPD1 to EGF stimulation sites potentiates EGFR activation.

    Directory of Open Access Journals (Sweden)

    Pedro Roda-Navarro

    Full Text Available Balanced activity of protein tyrosine kinases and phosphatases (PTPs controls tyrosine phosphorylation levels and, consequently, is needed to prevent pathologies like cancer. Phosphatase activity is tightly regulated in space and time. Thus, in order to understand how phospho-tyrosine signalling is regulated, the intracellular dynamics of PTPs should be investigated. Here, we have studied the intracellular dynamics of PTPD1, a FERM (four-point-one, ezrin, radixin, moesin domain-containing PTP that is over expressed in cancer cells and potentiates EGFR signalling. Whereas PTPD1 was excluded from E-cadherin rich cell-cell adhesions in epithelial cell monolayers, it diffused from the cytoplasm to those membranes in contact with the extracellular medium. Localisation of PTPD1 at the plasma membrane was mediated by its FERM domain and enabled the formation of EGFR/PTPD1-containing signalling complexes that pre-existed at the plasma membrane before EGF stimulation. PTPD1 and EGFR transiently co-localised at EGF stimulation sites until the formation of macropinosomes containing active species of EGFR. Interference of PTPD1 expression caused a decrease in EGFR phosphorylated species at the periphery of the cell. Presented data suggest that the transient formation of dynamic PTPD1/EGFR signalling complexes strengthens EGF signalling by promoting the spatial propagation of EGFR phosphorylated species.

  20. Molecular mechanisms of the synergy between cysteinyl-leukotrienes and receptor tyrosine kinase growth factors on human bronchial fibroblast proliferation

    Directory of Open Access Journals (Sweden)

    Hajime Yoshisue

    2006-12-01

    Full Text Available We have reported that cysteinyl-leukotrienes (cys-LTs synergise not only with epidermal growth factor (EGF but also with platelet-derived growth factor (PDGF and fibroblast growth factor (FGF to induce mitogenesis in human bronchial fibroblasts. We now describe the molecular mechanisms underlying this synergism. Mitogenesis was assessed by incorporation of [3H]thymidine into DNA and changes in protein phosphorylation by Western blotting. Surprisingly, no CysLT receptor antagonists (MK-571, montelukast, BAY u9773 prevented the synergistic mitogenesis. LTD4 did not cause phosphorylation of EGFR nor did it augment EGF-induced phosphorylation of EGFR, and the synergy between LTD4 and EGF was not blocked by the metalloproteinase inhibitor GM6001 or by an HB-EGF neutralising antibody. The EGFR-selective kinase inhibitor, AG1478, suppressed the synergy by LTD4 and EGF, but had no effect on the synergy with PDGF and FGF. While inhibitors of mitogen-activated protein kinase, phosphatidylinositol 3-kinase and protein kinase C (PKC prevented the synergy, these drugs also inhibited mitogenesis elicited by EGF alone. In contrast, pertussis toxin (PTX efficiently inhibited the potentiating effect of LTD4 on EGF-induced mitogenesis, as well as that provoked by PDGF or FGF, but had no effect on mitogenesis elicited by the growth factors alone. Whereas LTD4 alone did not augment phosphorylation of extracellular signal-regulated kinase (Erk-1/2 and Akt, it increased phosphorylation of PKC in a Gi-dependent manner. Addition of LTD4 prolonged the duration of EGF-induced phosphorylation of Erk-1/2 and Akt, both of which were sensitive to PTX. The effect of cys-LTs involves a PTX-sensitive and PKC-mediated intracellular pathway leading to sustained growth factor-dependent phosphorylation of Erk-1/2 and Akt.

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

    Institute of Scientific and Technical Information of China (English)

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

    2003-01-01

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

  2. A novel strategy for the treatment of chronic wounds based on the topical administration of rhEGF-loaded lipid nanoparticles: In vitro bioactivity and in vivo effectiveness in healing-impaired db/db mice.

    Science.gov (United States)

    Gainza, Garazi; Pastor, Marta; Aguirre, José Javier; Villullas, Silvia; Pedraz, José Luis; Hernandez, Rosa Maria; Igartua, Manoli

    2014-07-10

    Lipid nanoparticles are currently receiving increasing interest because they permit the topical administration of proteins, such as recombinant human epidermal growth factor (rhEGF), in a sustained and effective manner. Because chronic wounds have become a major healthcare burden, the topical administration of rhEGF-loaded lipid nanoparticles, namely solid lipid nanoparticles (SLN) and nanostructured lipid carries (NLC), appears to be an interesting and suitable strategy for the treatment of chronic wounds. Both rhEGF-loaded lipid nanoparticles were prepared through the emulsification-ultrasonication method; however, the NLC-rhEGF preparation did not require the use of any organic solvents. The characterisation of the nanoparticles (NP) revealed that the encapsulation efficiency (EE) of NLC-rhEGF was significantly greater than obtained with SLN-rhEGF. The in vitro experiments demonstrated that gamma sterilisation is a suitable process for the final sterilisation because no loss in activity was observed after the sterilisation process. In addition, the proliferation assays revealed that the bioactivity of the nanoformulations was even higher than that of free rhEGF. Finally, the effectiveness of the rhEGF-loaded lipid nanoparticles was assayed in a full-thickness wound model in db/db mice. The data demonstrated that four topical administrations of SLN-rhEGF and NLC-rhEGF significantly improved healing in terms of wound closure, restoration of the inflammatory process, and re-epithelisation grade. In addition, the data did not reveal any differences in the in vivo effectiveness between the different rhEGF-loaded lipid nanoparticles. Overall, these findings demonstrate the promising potential of rhEGF-loaded lipid nanoparticles, particularly NLC-rhEGF, for the promotion of faster and more effective healing and suggest their future application for the treatment of chronic wounds.

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

    Directory of Open Access Journals (Sweden)

    David E. Heppner

    2016-08-01

    Full Text Available 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.

  4. Fibroblast growth factor signaling during early vertebrate development.

    Science.gov (United States)

    Böttcher, Ralph T; Niehrs, Christof

    2005-02-01

    Fibroblast growth factors (FGFs) have been implicated in diverse cellular processes including apoptosis, cell survival, chemotaxis, cell adhesion, migration, differentiation, and proliferation. This review presents our current understanding on the roles of FGF signaling, the pathways employed, and its regulation. We focus on FGF signaling during early embryonic processes in vertebrates, such as induction and patterning of the three germ layers as well as its function in the control of morphogenetic movements.

  5. Perturbation of EGF-induced MAP kinase activation by TGF-ß1

    Directory of Open Access Journals (Sweden)

    Wenner C.E.

    1999-01-01

    Full Text Available TGF-ß1 regulates both cellular growth and phenotypic plasticity important for maintaining a growth advantage and increased invasiveness in progressively malignant cells. Recent studies indicate that TGF-ß-1 stimulates the conversion of epitheliod to fibroblastoid phenotype which presumably leads to the inactivation of growth-inhibitory effects by TGF-ß1 (Portella et al. (1998 Cell Growth and Differentiation, 9: 393-404. Therefore, the investigation of TGF-ß1 signaling that leads to altered growth and migration may provide novel targets for the prevention of increased cell growth and invasion. Although much attention has been paid to TGF-ß1 responses in epithelial cells, the above studies suggest that examination of signal transduction pathways in fibroblasts are important as well. Data from our laboratory are consistent with the concept that TGF-ß1 can act as a regulatory switch in density-dependent C3H 10T1/2 fibroblasts capable of either promoting or delaying G1 traverse. The regulation of this switch is proposed to occur prior to pRb phosphorylation, namely prior to activation of cyclin-dependent kinases. The current study is concerned with the evaluation of a key cyclin (cyclin D1 which activates cdk4 and p27KIP1 which in turn inhibit cdk2 in the proliferative responses of epidermal growth factor (EGF and platelet-derived growth factor (PDGF and their modulation by TGF-ß1. Although the molecular events that lead to elevation of cyclin D1 are not completely understood, it appears likely that activation of p42/p44MAPK kinases is involved in its transcriptional regulation. TGF-ß1 delayed EGF- or PDGF-induced cyclin D1 expression and blocked the induction of active p42/p44MAPK. The mechanism by which TGF-ß1 induces a block in p42/p44MAPK activation is being examined and the possibility that TGF-ß1 regulates phosphatase activity is being tested.

  6. Enhanced Phosphoproteomic Profiling Workflow For Growth Factor Signaling Analysis

    DEFF Research Database (Denmark)

    Sylvester, Marc; Burbridge, Mike; Leclerc, Gregory;

    2010-01-01

    Background Our understanding of complex signaling networks is still fragmentary. Isolated processes have been studied extensively but cross-talk is omnipresent and precludes intuitive predictions of signaling outcomes. The need for quantitative data on dynamic systems is apparent especially for our...... A549 lung carcinoma cells were used as a model and stimulated with hepatocyte growth factor, epidermal growth factor or fibroblast growth factor. We employed a quick protein digestion workflow with spin filters without using urea. Phosphopeptides in general were enriched by sequential elution from...... transfer dissociation adds confidence in modification site assignment. The workflow is relatively simple but the integration of complementary techniques leads to a deeper insight into cellular signaling networks and the potential pharmacological intervention thereof....

  7. Enhanced Phosphoproteomic Profiling Workflow For Growth Factor Signaling Analysis

    DEFF Research Database (Denmark)

    Sylvester, Marc; Burbridge, Mike; Leclerc, Gregory

    2010-01-01

    understanding of pathological processes. In our study we create and integrate data on phosphorylations that are initiated by several growth factor receptors. We present an approach for quantitative, time-resolved phosphoproteomic profiling that integrates the important contributions by phosphotyrosines. Methods...... A549 lung carcinoma cells were used as a model and stimulated with hepatocyte growth factor, epidermal growth factor or fibroblast growth factor. We employed a quick protein digestion workflow with spin filters without using urea. Phosphopeptides in general were enriched by sequential elution from...... in order to maximize identification of peptides as well as localization of phosphorylation sites. Results and Conclusions The combination of SIMAC with phosphotyrosine enrichment leads to a significant increase in identification of potential signaling events in growth factor receptor signaling networks...

  8. Modulation of the tumor microenvironment and inhibition of EGF/EGFR pathway: novel anti-tumor mechanisms of Cannabidiol in breast cancer.

    Science.gov (United States)

    Elbaz, Mohamad; Nasser, Mohd W; Ravi, Janani; Wani, Nissar A; Ahirwar, Dinesh K; Zhao, Helong; Oghumu, Steve; Satoskar, Abhay R; Shilo, Konstantin; Carson, William E; Ganju, Ramesh K

    2015-04-01

    The anti-tumor role and mechanisms of Cannabidiol (CBD), a non-psychotropic cannabinoid compound, are not well studied especially in triple-negative breast cancer (TNBC). In the present study, we analyzed CBD's anti-tumorigenic activity against highly aggressive breast cancer cell lines including TNBC subtype. We show here -for the first time-that CBD significantly inhibits epidermal growth factor (EGF)-induced proliferation and chemotaxis of breast cancer cells. Further studies revealed that CBD inhibits EGF-induced activation of EGFR, ERK, AKT and NF-kB signaling pathways as well as MMP2 and MMP9 secretion. In addition, we demonstrated that CBD inhibits tumor growth and metastasis in different mouse model systems. Analysis of molecular mechanisms revealed that CBD significantly inhibits the recruitment of tumor-associated macrophages in primary tumor stroma and secondary lung metastases. Similarly, our in vitro studies showed a significant reduction in the number of migrated RAW 264.7 cells towards the conditioned medium of CBD-treated cancer cells. The conditioned medium of CBD-treated cancer cells also showed lower levels of GM-CSF and CCL3 cytokines which are important for macrophage recruitment and activation. In summary, our study shows -for the first time-that CBD inhibits breast cancer growth and metastasis through novel mechanisms by inhibiting EGF/EGFR signaling and modulating the tumor microenvironment. These results also indicate that CBD can be used as a novel therapeutic option to inhibit growth and metastasis of highly aggressive breast cancer subtypes including TNBC, which currently have limited therapeutic options and are associated with poor prognosis and low survival rates.

  9. EGF-modified mPEG-PLGA-PLL nanoparticle for delivering doxorubicin combined with Bcl-2 siRNA as a potential treatment strategy for lung cancer.

    Science.gov (United States)

    Zhang, Xiangyu; Wang, Qi; Qin, Liubing; Fu, Hao; Fang, Yiwei; Han, Baoshan; Duan, Yourong

    2016-10-01

    Nanoparticles (NPs) have been widely used as carriers to deliver siRNA and chemotherapeutic agents. Bcl-2 siRNA has been widely used to induce cancer cell apoptosis, and doxorubicin (Dox) can destroy cancer cells by binding with cancer cell DNA. To investigate the therapeutic effect on lung cancer of simultaneously delivering Dox and Bcl-2-siRNA using epidermal growth factor (EGF) modified monomethoxy (polyethylene glycol)-poly (D, L-lactide-co-glycolide)-poly(L-lysine) (mPEG-PLGA-PLL, PEAL) NPs (EGF-PEAL). EGF-PEAL NPs were characterized with respect to size, zeta potential and morphology. Cytotoxicity and drug (or siRNA) loading capacity of EGF-PEAL NPs were analyzed. Cellular uptake, drug release profile, cell killing effects of Dox and Bcl-2-siRNA-loaded EGF-PEAL NPs were assessed. Biodistribution and therapeutic effects of Dox and Bcl-2-siRNA EGF-PEAL NPs were evaluated in H1299 tumor-bearing mice. EGF-PEAL NPs or PEAL NPs had nearly negligible cytotoxicity toward H1299 cells. Dox and Bcl-2-siRNA gradually released from EGF-PEAL NPs and exhibited sustained release patterns. Dox and Bcl-2-siRNA-loaded NPs were taken up by cells and induced the apoptosis of H1299 cells more effectively than using Dox or Bcl-2 siRNA alone. With the intravenous injection of PEAL NPs into H1299 xenografted mice, we found that combination treatment suppressed lung cancer growth and reduced Bcl-2 expression in tumor tissue, and EGF-PEAL NPs concentrated in lung tumor much more than non-targeted PEAL NPs. We conclude that co-delivery of Dox and Bcl-2-siRNA by tumor-targeted EGF-PEAL NPs could significantly inhibit lung cancer growth.

  10. Pig epidermal growth factor precursor contains segments that are highly conserved among species

    DEFF Research Database (Denmark)

    Jørgensen, P E; Jensen, L.G.; Sørensen, B S

    1998-01-01

    The 53-aa polypeptide epidermal growth factor (EGF) is synthesized as a 1200-aa precursor. The non-EGF part of the precursor is very long compared with EGF, and can therefore be expected to have a biological role of its own. We have sequenced cDNA of the pig EGF precursor and compared a 668-aa se...

  11. Epidermal growth factor in the rat lung

    DEFF Research Database (Denmark)

    Raaberg, Lasse; Poulsen, Steen Seier; Nexø, Ebba

    1991-01-01

    Epidermal Growth Factor (EGF) in pharmacological doses is able to induce precoccious lung maturation in rabbits and sheeps. As EGF is probably acting in a para- or autocrine way, we have searched for EGF in the lungs. We report EGF immunoreactivity to be present in the type II pneumocytes...... of the rat from a couple of days prior to birth and throughout life. Further, we report EGF immunoreactivity to be present in cells in the bronchi and the bronchioles from day 20-21 of gestation and throughout life. G-200 gelchromatography of lung extracts indicates that the EGF-reactive material is a high...... molecular weight form of EGF. Since previous studies have shown that EGF in pharmacological doses is able to promote lung maturation, our results may imply a physiological role for EGF in the lungs....

  12. Fibroblast growth factor (FGF) signaling in development and skeletal diseases.

    Science.gov (United States)

    Teven, Chad M; Farina, Evan M; Rivas, Jane; Reid, Russell R

    2014-12-01

    Fibroblast growth factors (FGF) and their receptors serve many functions in both the developing and adult organism. Humans contain 18 FGF ligands and four FGF receptors (FGFR). FGF ligands are polypeptide growth factors that regulate several developmental processes including cellular proliferation, differentiation, and migration, morphogenesis, and patterning. FGF-FGFR signaling is also critical to the developing axial and craniofacial skeleton. In particular, the signaling cascade has been implicated in intramembranous ossification of cranial bones as well as cranial suture homeostasis. In the adult, FGFs and FGFRs are crucial for tissue repair. FGF signaling generally follows one of three transduction pathways: RAS/MAP kinase, PI3/AKT, or PLCγ. Each pathway likely regulates specific cellular behaviors. Inappropriate expression of FGF and improper activation of FGFRs are associated with various pathologic conditions, unregulated cell growth, and tumorigenesis. Additionally, aberrant signaling has been implicated in many skeletal abnormalities including achondroplasia and craniosynostosis. The biology and mechanisms of the FGF family have been the subject of significant research over the past 30 years. Recently, work has focused on the therapeutic targeting and potential of FGF ligands and their associated receptors. The majority of FGF-related therapy is aimed at age-related disorders. Increased understanding of FGF signaling and biology may reveal additional therapeutic roles, both in utero and postnatally. This review discusses the role of FGF signaling in general physiologic and pathologic embryogenesis and further explores it within the context of skeletal development.

  13. The Smad pathway in transforming growth factorsignaling

    Institute of Scientific and Technical Information of China (English)

    林海燕; 王红梅; 祝诚

    2003-01-01

    The Smad pathway is involved in transforming growth factor-β (TGF-β) signal transduction. The Smad complex binds with the promoter of target gene to modulate gene transcription. Various transcriptional coactivators and corepressors associate directly with Smads for appropriate binding of Smads to target promoters and regulation of Smads transcriptional activities. The ultimate degradation of Smads mediated by the ubiquitin-proteasome pathway (UPP) has been established as a mechanism to shut off the Smad pathway. In addition to the Smad pathway, TGF-β can also activate other signaling pathway such as the MAPK pathway. The cross-talk of the Smad pathway with other signaling pathways constitutes an important mechanism for the regulatory network of TGF-β Signaling.

  14. Fibroblast growth factor signaling in mammalian tooth development.

    Science.gov (United States)

    Li, Chun-Ying; Prochazka, Jan; Goodwin, Alice F; Klein, Ophir D

    2014-01-01

    In this review, we discuss the central role of fibroblast growth factor (FGF) signaling in mammalian tooth development. The FGF family consists of 22 members, most of which bind to four different receptor tyrosine kinases, which in turn signal through a cascade of intracellular proteins. This signaling regulates a number of cellular processes, including proliferation, differentiation, cell adhesion and cell mobility. FGF signaling first becomes important in the presumptive dental epithelium at the initiation stage of tooth development, and subsequently, it controls the invagination of the dental epithelium into the underlying mesenchyme. Later, FGFs are critical in tooth shape formation and differentiation of ameloblasts and odontoblasts, as well as in the development and homeostasis of the stem cell niche that fuels the continuously growing mouse incisor. In addition, FGF signaling is critical in human teeth, as mutations in genes encoding FGF ligands or receptors result in several congenital syndromes characterized by alterations in tooth number, morphology or enamel structure. The parallel roles of FGF signaling in mouse and human tooth development demonstrate the conserved importance of FGF signaling in mammalian odontogenesis.

  15. Nod factor signal transduction in the Rhizobium-legume symbiosis

    NARCIS (Netherlands)

    Limpens, E.H.M.; Bisseling, T.

    2008-01-01

    The symbiotic interaction between Rhizobium bacteria and most legume plants is initiated by the perception of bacterial signal molecules, the nodulation (Nod) factors, at the root hairs of the plant. This induces responses both in the root hairs, leading to infection by the bacteria, as well as at a

  16. Comparison of EGF with VEGF Non-Viral Gene Therapy for Cutaneous Wound Healing of Streptozotocin Diabetic Mice

    Directory of Open Access Journals (Sweden)

    Junghae Ko

    2011-06-01

    Full Text Available BackgroundTo accelerate the healing of diabetic wounds, various kinds of growth factors have been employed. It is the short half-life of administered growth factors in hostile wound beds that have limited wide-spread clinical usage. To overcome this limitation, growth factor gene therapy could be an attractive alternative rather than direct application of factors onto the wound beds. We administered two growth factor DNAs, epidermal growth factor (EGF and vascular endothelial growth factor (VEGF into a cutaneous wound on diabetic mice. We compared the different characteristics of the healing wounds.MethodsStreptozotocin was injected intraperitoneally to induce diabetes into C57BL/6J mice. The ultrasound micro-bubble destruction method with SonoVue as a bubbling agent was used for non-viral gene delivery of EGF828 and VEGF165 DNAs. Each gene was modified for increasing efficacy as FRM-EGF828 or minicircle VEGF165. The degree of neoangiogenesis was assessed using qualitative laser Doppler flowmetry. We compared wound size and histological findings of the skin wounds in each group.ResultsIn both groups, accelerated wound closure was observed in the mice receiving gene therapy compared with non treated diabetic control mice. Blood flow detected by laser doppler flowmetry was better in the VEGF group than in the EGF group. Wound healing rates and histological findings were more accelerated in the EGF gene therapy group than the VEGF group, but were not statistically significant.ConclusionBoth non-viral EGF and VEGF gene therapy administrations could improve the speed and quality of skin wound healing. However, the detailed histological characteristics of the healing wounds were different.

  17. Epidermal growth factor in the rat prostate

    DEFF Research Database (Denmark)

    Tørring, Niels; Jørgensen, P E; Poulsen, Steen Seier;

    1998-01-01

    Epidermal growth factor (EGF) induces proliferation in prostate epithelial and stromal cells in primary culture. This investigation was set up to characterize the time and spatial expression of EGF in the rat prostate.......Epidermal growth factor (EGF) induces proliferation in prostate epithelial and stromal cells in primary culture. This investigation was set up to characterize the time and spatial expression of EGF in the rat prostate....

  18. Beclin 1 regulates growth factor receptor signaling in breast cancer.

    Science.gov (United States)

    Rohatgi, R A; Janusis, J; Leonard, D; Bellvé, K D; Fogarty, K E; Baehrecke, E H; Corvera, S; Shaw, L M

    2015-10-16

    Beclin 1 is a haploinsufficient tumor suppressor that is decreased in many human tumors. The function of beclin 1 in cancer has been attributed primarily to its role in the degradative process of macroautophagy. However, beclin 1 is a core component of the vacuolar protein sorting 34 (Vps34)/class III phosphatidylinositoI-3 kinase (PI3KC3) and Vps15/p150 complex that regulates multiple membrane-trafficking events. In the current study, we describe an alternative mechanism of action for beclin 1 in breast cancer involving its control of growth factor receptor signaling. We identify a specific stage of early endosome maturation that is regulated by beclin 1, the transition of APPL1-containing phosphatidyIinositol 3-phosphate-negative (PI3P(-)) endosomes to PI3P(+) endosomes. Beclin 1 regulates PI3P production in response to growth factor stimulation to control the residency time of growth factor receptors in the PI3P(-)/APPL(+)-signaling-competent compartment. As a result, suppression of BECN1 sustains growth factor-stimulated AKT and ERK activation resulting in increased breast carcinoma cell invasion. In human breast tumors, beclin 1 expression is inversely correlated with AKT and ERK phosphorylation. Our data identify a novel role for beclin 1 in regulating growth factor signaling and reveal a mechanism by which loss of beclin 1 expression would enhance breast cancer progression.

  19. Monosomy of Chromosome 10 Associated With Dysregulation of Epidermal Growth Factor Signaling in Glioblastomas

    Science.gov (United States)

    Yadav, Ajay K.; Renfrow, Jaclyn J.; Scholtens, Denise M.; Xie, Hehuang; Duran, George E.; Bredel, Claudia; Vogel, Hannes; Chandler, James P.; Chakravarti, Arnab; Robe, Pierre A.; Das, Sunit; Scheck, Adrienne C.; Kessler, John A.; Soares, Marcelo B.; Sikic, Branimir I.; Harsh, Griffith R.; Bredel, Markus

    2011-01-01

    Context Glioblastomas—uniformly fatal brain tumors—often have both monosomy of chromosome 10 and gains of the epidermal growth factor receptor (EGFR) gene locus on chromosome 7, an association for which the mechanism is poorly understood. Objectives To assess whether coselection of EGFR gains on 7p12 and monosomy 10 in glioblastomas promotes tumorigenic epidermal growth factor (EGF) signaling through loss of the annexin A7 (ANXA7) gene on 10q21.1–q21.2 and whether ANXA7 acts as a tumor suppressor gene by regulating EGFR in glioblastomas. Design, Setting, and Patients Multidimensional analysis of gene, coding sequence, promoter methylation, messenger RNA (mRNA) transcript, protein data for ANXA7 (and EGFR), and clinical patient data profiles of 543 high-grade gliomas from US medical centers and The Cancer Genome Atlas pilot project (made public 2006–2008; and unpublished, tumors collected 2001–2008). Functional analyses using LN229 and U87 glioblastoma cells. Main Outcome Measures Associations among ANXA7 gene dosage, coding sequence, promoter methylation, mRNA transcript, and protein expression. Effect of ANXA7 haploinsufficiency on EGFR signaling and patient survival. Joint effects of loss of ANXA7 and gain of EGFR expression on tumorigenesis. Results Heterozygous ANXA7 gene deletion is associated with significant loss of ANXA7 mRNA transcript expression (P=1×10−15; linear regression) and a reduction (mean [SEM]) of 91.5% (2.3%) of ANXA7 protein expression compared with ANXA7 wild-type glioblastomas (P=.004; unpaired t test). ANXA7 loss of function stabilizes the EGFR protein (72%–744% increase in EGFR protein abundance) and augments EGFR transforming signaling in glioblastoma cells. ANXA7 haploinsufficiency doubles tumorigenic potential of glioblastoma cells, and combined ANXA7 knockdown and EGFR overexpression promotes tumorigenicity synergistically. The heterozygous loss of ANXA7 in≈75% of glioblastomas in the The Cancer Genome Atlas plus

  20. Involvement of cysteine-rich protein 61 in the epidermal growth factor-induced migration of human anaplastic thyroid cancer cells.

    Science.gov (United States)

    Chin, Li-Han; Hsu, Sung-Po; Zhong, Wen-Bin; Liang, Yu-Chih

    2016-05-01

    Anaplastic thyroid cancer (ATC) is among the most aggressive types of malignant cancer. Epidermal growth factor (EGF) plays a crucial role in the pathogenesis of ATC, and patients with thyroid carcinoma typically exhibit increased cysteine-rich protein 61 (Cyr61). In this study, we found that EGF treatment induced cell migration, stress fiber formation, Cyr61 mRNA and protein expressions, and Cyr61 protein secretion in ATC cells. The recombinant Cyr61 protein significantly induced cell migration; however, inhibition of Cyr61 activity by a Cyr61-specific antibody abrogated EGF-induced cell migration. EGF treatment also affected epithelial-to-mesenchymal transition (EMT)-related marker protein expression, as evidenced by an increase in vimentin and a decrease in E-cadherin expression. Inhibition of Cyr61 expression by Cyr61 siRNA decreased cell migration and reversed the EMT-related marker protein expression. EGF treatment increased the phosphorylation of the extracellular signal-regulated kinase (ERK) and cAMP response element-binding protein (CREB), and finally activated Cyr61 promoter plasmid activity. Our results suggest that Cyr61 is induced by EGF through the ERK/CREB signal pathway and that it plays a crucial role in the migration and invasion of ATC cells; moreover, Cyr61 might be a therapeutic target for metastatic ATC.

  1. Multiple processing of Ig-Hepta/GPR116, a G protein-coupled receptor with immunoglobulin (Ig)-like repeats, and generation of EGF2-like fragment.

    Science.gov (United States)

    Fukuzawa, Taku; Hirose, Shigehisa

    2006-09-01

    Ig-Hepta/GPR116 is a member of the LNB-TM7 subfamily of G protein-coupled receptors (GPCRs), also termed the adhesion GPCRs, whose members have EGF, cadherin, lectin, thrombospondin, or Ig repeats in their long N-terminus. In this study, we established that Ig-Hepta is processed at multiple sites yielding the following four fragments: (i) presequence (amino acid residues 1-24), (ii) proEGF2 (25-223, alpha-fragment), (iii) Ig repeats (224-993, beta-chain), and (iv) TM7 (994-1349, gamma-chain). The proEGF2 region is converted to EGF2 (52-223) by the processing enzyme furin and remains attached to the beta- and gamma-chains. Expression of some mRNA species was affected by the presence of alpha-fragment. These results suggest that the furin-processed alpha-fragment is involved in cellular signaling.

  2. The EGF/CSF-1 Paracrine Invasion Loop Can Be Triggered by Heregulin beta 1 and CXCL12

    NARCIS (Netherlands)

    Hernandez, L.; Smirnova, T.; Kedrin, D.; Wyckoff, J.; Zhu, L.; Stanley, E.R.; Cox, D.G.; Muller, W.J.; Pollard, J.W.; Rooijen, van N.; Segall, J.E.

    2009-01-01

    An important step in the process of metastasis from the primary tumor is invasive spread into the surrounding stroma. Using an in vivo invasion assay, we have previously shown that imposed gradients of epidermal growth factor (EGF) or colony-stimulating factor-1 (CSF-1) can induce invasion through a

  3. Wnt signaling through T-cell factor phosphorylation

    Institute of Scientific and Technical Information of China (English)

    Sergei Y Sokol

    2011-01-01

    Embryonic signaling pathways often lead to a switch from default repression to transcriptional activation of target genes. A major consequence of Wnt signaling is stabilization of p-catenin, which associates with T-cell factors (TCFs) and 'converts' them from repressors into transcriptional activators. The molecular mechanisms responsible for this conversion remain poorly understood. Several studies have reported on the regulation of TCF by phosphorylation,yet its physiological significance has been unclear: in some cases it appears to promote target gene activation, in oth-ers Wnt-dependent transcription is inhibited. This review focuses on recent progress in the understanding of context-dependent post-translational regulation of TCF function by Wnt signaling.

  4. A cross-talk between the androgen receptor and the epidermal growth factor receptor leads to p38MAPK-dependent activation of mTOR and cyclinD1 expression in prostate and lung cancer cells.

    Science.gov (United States)

    Recchia, Anna Grazia; Musti, Anna Maria; Lanzino, Marilena; Panno, Maria Luisa; Turano, Ermanna; Zumpano, Rachele; Belfiore, Antonino; Andò, Sebastiano; Maggiolini, Marcello

    2009-03-01

    In androgen sensitive LNCaP prostate cancer cells, the proliferation induced by the epidermal growth factor (EGF) involves a cross-talk between the EGF receptor (EGFR) and the androgen receptor (AR). In lung cancer the role of the EGF-EGFR transduction pathway has been documented, whereas androgen activity has received less attention. Here we demonstrate that in LNCaP and A549 non-small cell lung cancer (NSCLC), AR and EGFR are required for either 5alpha-dihydrotestosterone (DHT) or EGF-stimulated cell growth. Only EGF activated ERK signaling and up-regulated early gene expression, while DHT triggered the expression of classical AR-responsive genes with the exception of the EGF-induced PSA transcript in A549 cells. DHT and EGF up-regulated cyclinD1 (CD1) at both mRNA and protein levels in A549 cells, while in LNCaP cells each mitogen increased only CD1 protein expression. In both cell contexts, CD1 up-regulation was prevented by selective inhibitors as well as by knock-down of either AR or EGFR and also inhibiting p38MAPK and the mammalian target of rapamycin (mTOR) pathways. Interestingly, p38MAPK and mTOR repression prevented the activation of the mTOR target ribosomal p70S6 kinase induced by DHT and EGF, indicating that p38MAPK acts as an upstream mTOR regulator. In addition, the proliferative effects promoted by both DHT and EGF in LNCaP and A549 cancer cells were no longer observed blocking either p38MAPK or mTOR activity. Hence, our data suggest that p38MAPK-dependent activation of the mTOR/CD1 pathway may represent a mechanism through which AR and EGFR cross-talk contributes to prostate and lung cancer progression.

  5. Cloning of a novel signaling molecule, AMSH-2, that potentiates transforming growth factor β signaling

    Directory of Open Access Journals (Sweden)

    Pandey Akhilesh

    2004-01-01

    Full Text Available Abstract Background Transforming growth factor-βs (TGF-βs, bone morphogenetic proteins (BMPs and activins are important regulators of developmental cell growth and differentiation. Signaling by these factors is mediated chiefly by the Smad family of latent transcription factors. Results There are a large number of uncharacterized cDNA clones that code for novel proteins with homology to known signaling molecules. We have identified a novel molecule from the HUGE database that is related to a previously known molecule, AMSH (associated molecule with the SH3 domain of STAM, an adapter shown to be involved in BMP signaling. Both of these molecules contain a coiled-coil domain located within the amino-terminus region and a JAB (Domain in Jun kinase activation domain binding protein and proteasomal subunits domain at the carboxy-terminus. We show that this novel molecule, which we have designated AMSH-2, is widely expressed and its overexpression potentiates activation of TGF-β-dependent promoters. Coimmunoprecipitation studies indicated that Smad7 and Smad2, but not Smad3 or 4, interact with AMSH-2. We show that overexpression of AMSH-2 decreases the inhibitory effect of Smad7 on TGF-β signaling. Finally, we demonstrate that knocking down AMSH-2 expression by RNA interference decreases the activation of 3TP-lux reporter in response to TGF-β. Conclusions This report implicates AMSH and AMSH-2 as a novel family of molecules that positively regulate the TGF-β signaling pathway. Our results suggest that this effect could be partially explained by AMSH-2 mediated decrease of the action of Smad7 on TGF-β signaling pathway.

  6. La ciclooxigenasa-2 (COX-2 y el factor de crecimiento epidérmico (EFG en lesiones epiteliales orales premalignas Cyclooxygenase-2 (COX-2 and epidermal growth factor (EGF in oral premalignant epithelial lesions

    Directory of Open Access Journals (Sweden)

    S. Díaz Prado

    2009-06-01

    Full Text Available Las lesiones premalignas orales incluyen eritroplasias (manchas rojas y leucoplasias (manchas blancas, las cuales se desarrollan a lo largo de superficies epiteliales. Estas lesiones son considerados marcadores en la "carcinogénesis de campo" ya que pacientes con lesiones premalignas orales pueden desarrollar carcinoma de células escamosas (CCS en el sitio de las lesiones, así como en otros lugares de tracto aerodigestivo superior. Se está haciendo un gran esfuerzo para identificar nuevos biomarcadores SEBs (surrogate endpoint biomarkers para el carcinoma de células escamosas de cabeza y cuello. Los SEBs candidatos para el carcinoma de células escamosas invasivo en el trato aerodigestivo superior deben ser detectables con los cambios moleculares celulares y tisulares que tienen lugar durante la formación del tumor. Entre los diferentes marcadores que se han propuesto hasta la actualidad, la ciclooxigenasa- 2 (COX-2 y el receptor del factor de crecimiento epidérmico (EGFR parecen ser los más prometedores. COX-2 se sobre expresa durante el proceso tumoral, desde hiperplasia temprana a enfermedad metastásica. EGFR también está anormalmente activado en tumores epiteliales, pues las células de casi todas estas neoplasias expresan altos niveles de este receptor, una característica asociada con un peor pronóstico clínico. En este sentido el tracto aerodigestivo superior proporciona un sistema o modelo único para el estudio de CCS y para la investigación de nuevos candidatos SEBs.Oral premalignant lesions include leukoplakia (white patch and erythroplakia (red patch, which develop on epithelial surfaces. These lesions are markers for field cancerization because patients with oral premalignancy can develop squamous cell carcinoma at the site of the lesion(s and at other sites in the upper aerodigestive tract. An effort is being made to identify surrogate endpoint biomarkers (SEBs for head and neck squamous cell carcinoma (HNSCC

  7. Role of 3'-5'-cyclic adenosine monophosphate on the epidermal growth factor dependent survival in mammary epithelial cells.

    Science.gov (United States)

    Grinman, Diego Y; Romorini, Leonardo; Presman, Diego M; Rocha-Viegas, Luciana; Coso, Omar A; Davio, Carlos; Pecci, Adali

    2016-01-01

    Epidermal growth factor (EGF) has been suggested to play a key role in the maintenance of epithelial cell survival during lactation. Previously, we demonstrated that EGF dependent activation of PI3K pathway prevents apoptosis in confluent murine HC11 cells cultured under low nutrient conditions. The EGF protective effect is associated with increased levels of the antiapoptotic protein Bcl-XL. Here, we identify the EGF-dependent mechanism involved in cell survival that converges in the regulation of bcl-X expression by activated CREB. EGF induces Bcl-XL expression through activation of a unique bcl-X promoter, the P1; being not only the PI3K/AKT signaling pathway but also the increase in cAMP levels and the concomitant PKA/CREB activation necessary for both bcl-XL upregulation and apoptosis avoidance. Results presented in this work suggest the existence of a novel connection between the EGF receptor and the adenylate cyclase that would have an impact in preventing apoptosis under low nutrient conditions.

  8. Regulation of Epidermal Growth Factor Receptor Trafficking by Lysine Deacetylase HDAC6

    DEFF Research Database (Denmark)

    Lissanu Deribe, Yonathan; Wild, Philipp; Chandrashaker, Akhila;

    2009-01-01

    Binding of epidermal growth factor (EGF) to its receptor leads to receptor dimerization, assembly of protein complexes, and activation of signaling networks that control key cellular responses. Despite their fundamental role in cell biology, little is known about protein complexes associated...

  9. Does epidermal growth factor play a role in the action of sucralfate?

    DEFF Research Database (Denmark)

    Nexø, Ebba; Poulsen, Steen Seier

    1987-01-01

    the effector system of EGF. We conclude that Sucralfate does not change the binding of EGF to its receptor, but it is able to bind EGF in a pH dependent manner and at pH below 4.5 virtually all EGF is bound to Sucralfate. In vivo studies in rats with acid-induced gastric ulcers show that sucralfate carries EGF......Epidermal growth factor (EGF) is a mitogenic peptide synthesized in the submandibular glands and released in saliva. EGF is able to prevent the development of gastrointestinal ulcers in the rat and to accelerate their healing. The present work was undertaken to examine whether Sucralfate acts via...... to the ulcer, and that EGF is available for a longer period of time (3 hours) when EGF and Sucralfate are is given together than when EGF is given alone....

  10. Blocking Epidermal Growth Factor Receptor Signaling in HTR-8/SVneo First Trimester Trophoblast Cells Results in Dephosphorylation of PKBα/AKT and Induces Apoptosis

    Directory of Open Access Journals (Sweden)

    J. Bolnick

    2011-01-01

    Full Text Available We identified a major peptide signaling target of EGF/EGFR pathway and explored the consequences of blocking or activating this pathway in the first trimester extravillous trophoblast cells, HTR-8/SVneo. A global analysis of protein phosphorylation was undertaken using novel technology (Kinexus Kinetworks that utilizes SDS-polyacrylamide minigel electrophoresis and multi-lane immunoblotting to permit specific and semiquantitative detection of multiple phosphoproteins. Forty-seven protein phosphorylation sites were queried, and the results reported based on relative phosphorylation at each site. EGF- and Iressa-(gefitinib, ZD1839, an inhibitor of EGFR treated HTR-8/SVneo cells were subjected to immunoblotting and flow cytometry to confirm the phosphoprotein screen and to assess the effects of EGF versus Iressa on cell cycle and apoptosis. EGFR mediates the phosphorylation of important signaling proteins, including PKBα/AKT. This pathway is likely to be central to EGFR-mediated trophoblast survival. Furthermore, EGF treatment induces proliferation and inhibits apoptosis, while Iressa induces apoptosis.

  11. Oocyte induction of EGF responsiveness in somatic cells is associated with the acquisition of porcine oocyte developmental competence.

    Science.gov (United States)

    Ritter, Lesley J; Sugimura, Satoshi; Gilchrist, Robert B

    2015-06-01

    Oocytes progressively acquire the competence to support embryo development as oogenesis proceeds with ovarian folliculogenesis. The objectives of this study were to investigate oocyte-secreted factor (OSF) participation in the development of somatic cell epidermal growth factor (EGF) responsiveness associated with oocyte developmental competence. A well-established porcine model was employed using oocytes from small (4 mm) antral follicles, representing low vs moderate developmental competence, respectively. Cumulus-oocyte complexes (COCs) were treated in vitro with inducers of oocyte maturation, and cumulus cell functions and oocyte developmental competence were assessed. COCs from small follicles responded to FSH but, unlike COCs from larger follicles, were incapable of responding to EGF family growth factors known to mediate oocyte maturation in vivo, exhibiting perturbed cumulus expansion and expression of associated transcripts (HAS2 and TNFAIP6). Low and moderate competence COCs expressed equivalent levels of EGF receptor (EGFR) mRNA; however, the former had less total EGFR protein leading to failed activation of phospho-EGFR and phospho-ERK1/2, despite equivalent total ERK1/2 protein levels. Native OSFs from moderate, but not from low, competence oocytes established EGF responsiveness in low competence COCs. Four candidate recombinant OSFs failed to mimic the actions of native OSFs in regulating cumulus expansion. Treatment with OSFs and EGF enhanced oocyte competence but only of the low competence COCs. These data suggest that developmental acquisition by the oocyte of capacity to regulate EGF responsiveness in the oocyte's somatic cells is a major milestone in the oocyte's developmental program and contributes to coordinated oocyte and somatic cell development.

  12. Cooperation of tyrosine kinase receptor TrkB and epidermal growth factor receptor signaling enhances migration and dispersal of lung tumor cells.

    Directory of Open Access Journals (Sweden)

    Rudolf Götz

    Full Text Available TrkB mediates the effects of brain-derived neurotrophic factor (BDNF in neuronal and nonnneuronal cells. Based on recent reports that TrkB can also be transactivated through epidermal growth-factor receptor (EGFR signaling and thus regulates migration of early neurons, we investigated the role of TrkB in migration of lung tumor cells. Early metastasis remains a major challenge in the clinical management of non-small cell lung cancer (NSCLC. TrkB receptor signaling is associated with metastasis and poor patient prognosis in NSCLC. Expression of this receptor in A549 cells and in another adenocarcinoma cell line, NCI-H441, promoted enhanced migratory capacity in wound healing assays in the presence of the TrkB ligand BDNF. Furthermore, TrkB expression in A549 cells potentiated the stimulatory effect of EGF in wound healing and in Boyden chamber migration experiments. Consistent with a potential loss of cell polarity upon TrkB expression, cell dispersal and de-clustering was induced in A549 cells independently of exogeneous BDNF. Morphological transformation involved extensive cytoskeletal changes, reduced E-cadherin expression and suppression of E-cadherin expression on the cell surface in TrkB expressing tumor cells. This function depended on MEK and Akt kinase activity but was independent of Src. These data indicate that TrkB expression in lung adenoma cells is an early step in tumor cell dissemination, and thus could represent a target for therapy development.

  13. Signaling with homeoprotein transcription factors in development and throughout adulthood.

    Science.gov (United States)

    Prochiantz, A

    2013-09-01

    The concept of homeoprotein transduction as a novel signaling pathway has dramatically evolved since it was first proposed in 1991. It is now well established in several biological systems from plants to mammals. In this review, the different steps that have led to this unexpected observation are recalled and the developmental and physiological models that have allowed us (and a few others) to consolidate the original hypothesis are described. Because homeoprotein signaling is active in plants and animals it is proposed that it has predated the separation between animals and plants and is thus very ancient. This may explain why the basic phenomenon of homeoprotein transduction is so minimalist, requiring no specific receptors or transduction pathways beside those offered by mitochondria, organelles present in all eukaryotic cells. Indeed complexity has been added in the course of evolution and the conservation of homeoprotein transduction is discussed in the context of its synergy with bona fide signaling mechanism that may have added robustness to this primitive cell communication device. The same synergy possibly explains why homeoprotein signaling is important both in embryonic development and in adult functions fulfilled by signaling entities (e.g. growth factors) themselves active throughout development and in the adult. The cell biological mechanism of homeoprotein transfer is also discussed. Although it is clear that many questions are still in want of precise answers, it appears that the sequences responsible both for secretion and internalization are in the DNA-binding domain and very highly conserved among most homeoproteins. On this basis, it is proposed that this signaling pathway is likely to imply as many as 200 proteins that participate in a myriad of developmental and physiological pathways.

  14. Differential Roles of Grb2 and AP-2 in p38 MAPK- and EGF-Induced EGFR Internalization

    DEFF Research Database (Denmark)

    Grandal, Michael V; Grøvdal, Lene M; Henriksen, Lasse;

    2012-01-01

    also can induce EGFR endocytosis. This endocytosis lacks many of the characteristics of ligand-induced EGFR endocytosis. We compared the two types of endocytosis with regard to the requirements for proteins in the internalization machinery. Both types of endocytosis require clathrin, but while...... epidermal growth factor (EGF)-induced EGFR internalization also required Grb2, p38 MAPK-induced internalization did not. Interestingly, AP-2 knock down blocked p38 MAPK-induced EGFR internalization, but only mildly affected EGF-induced internalization. In line with this, simultaneously mutating two AP-2...... interaction sites in EGFR affected p38 MAPK-induced internalization much more than EGF-induced EGFR internalization. Thus, it seems that EGFR in the two situations uses different sets of internalization mechanisms....

  15. Use of SLAM and PVRL4 and identification of pro-HB-EGF as cell entry receptors for wild type phocine distemper virus.

    Directory of Open Access Journals (Sweden)

    Mary M Melia

    Full Text Available Signalling lymphocyte activation molecule (SLAM has been identified as an immune cell receptor for the morbilliviruses, measles (MV, canine distemper (CDV, rinderpest and peste des petits ruminants (PPRV viruses, while CD46 is a receptor for vaccine strains of MV. More recently poliovirus like receptor 4 (PVRL4, also known as nectin 4, has been identified as a receptor for MV, CDV and PPRV on the basolateral surface of polarised epithelial cells. PVRL4 is also up-regulated by MV in human brain endothelial cells. Utilisation of PVRL4 as a receptor by phocine distemper virus (PDV remains to be demonstrated as well as confirmation of use of SLAM. We have observed that unlike wild type (wt MV or wtCDV, wtPDV strains replicate in African green monkey kidney Vero cells without prior adaptation, suggesting the use of a further receptor. We therefore examined candidate molecules, glycosaminoglycans (GAG and the tetraspan proteins, integrin β and the membrane bound form of heparin binding epithelial growth factor (proHB-EGF,for receptor usage by wtPDV in Vero cells. We show that wtPDV replicates in Chinese hamster ovary (CHO cells expressing SLAM and PVRL4. Similar wtPDV titres are produced in Vero and VeroSLAM cells but more limited fusion occurs in the latter. Infection of Vero cells was not inhibited by anti-CD46 antibody. Removal/disruption of GAG decreased fusion but not the titre of virus. Treatment with anti-integrin β antibody increased rather than decreased infection of Vero cells by wtPDV. However, infection was inhibited by antibody to HB-EGF and the virus replicated in CHO-proHB-EGF cells, indicating use of this molecule as a receptor. Common use of SLAM and PVRL4 by morbilliviruses increases the possibility of cross-species infection. Lack of a requirement for wtPDV adaptation to Vero cells raises the possibility of usage of proHB-EGF as a receptor in vivo but requires further investigation.

  16. Use of SLAM and PVRL4 and identification of pro-HB-EGF as cell entry receptors for wild type phocine distemper virus.

    Science.gov (United States)

    Melia, Mary M; Earle, John Philip; Abdullah, Haniah; Reaney, Katherine; Tangy, Frederic; Cosby, Sara Louise

    2014-01-01

    Signalling lymphocyte activation molecule (SLAM) has been identified as an immune cell receptor for the morbilliviruses, measles (MV), canine distemper (CDV), rinderpest and peste des petits ruminants (PPRV) viruses, while CD46 is a receptor for vaccine strains of MV. More recently poliovirus like receptor 4 (PVRL4), also known as nectin 4, has been identified as a receptor for MV, CDV and PPRV on the basolateral surface of polarised epithelial cells. PVRL4 is also up-regulated by MV in human brain endothelial cells. Utilisation of PVRL4 as a receptor by phocine distemper virus (PDV) remains to be demonstrated as well as confirmation of use of SLAM. We have observed that unlike wild type (wt) MV or wtCDV, wtPDV strains replicate in African green monkey kidney Vero cells without prior adaptation, suggesting the use of a further receptor. We therefore examined candidate molecules, glycosaminoglycans (GAG) and the tetraspan proteins, integrin β and the membrane bound form of heparin binding epithelial growth factor (proHB-EGF),for receptor usage by wtPDV in Vero cells. We show that wtPDV replicates in Chinese hamster ovary (CHO) cells expressing SLAM and PVRL4. Similar wtPDV titres are produced in Vero and VeroSLAM cells but more limited fusion occurs in the latter. Infection of Vero cells was not inhibited by anti-CD46 antibody. Removal/disruption of GAG decreased fusion but not the titre of virus. Treatment with anti-integrin β antibody increased rather than decreased infection of Vero cells by wtPDV. However, infection was inhibited by antibody to HB-EGF and the virus replicated in CHO-proHB-EGF cells, indicating use of this molecule as a receptor. Common use of SLAM and PVRL4 by morbilliviruses increases the possibility of cross-species infection. Lack of a requirement for wtPDV adaptation to Vero cells raises the possibility of usage of proHB-EGF as a receptor in vivo but requires further investigation.

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

    Science.gov (United States)

    Andresen, Bradley T; Linnoila, Jenny J; Jackson, Edwin K; Romero, Guillermo G

    2003-03-01

    Angiotensin (Ang) II promotes the phosphorylation of extracellular regulated kinase (ERK); however, the mechanisms leading to Ang II-induced ERK phosphorylation are debated. The currently accepted theory involves transactivation of epidermal growth factor receptor (EGFR). We have shown that generation of phosphatidic acid (PA) is required for the recruitment of Raf to membranes and the activation of ERK by multiple agonists, including Ang II. In the present report, we confirm that phospholipase D-dependent generation of PA is required for Ang II-mediated phosphorylation of ERK in Wistar-Kyoto and spontaneously hypertensive rat preglomerular smooth muscle cells (PGSMCs). However, EGF stimulation does not activate phospholipase D or generate PA. These observations indicate that EGF recruits Raf to membranes via a mechanism that does not involve PA, and thus, Ang II-mediated phosphorylation of ERK is partially independent of EGFR-mediated signaling cascades. We hypothesized that phosphoinositide-3-kinase (PI3K) can also act to recruit Raf to membranes; therefore, inhibition of PI3K should inhibit EGF signaling to ERK. Wortmannin, a PI3K inhibitor, inhibited EGF-mediated phosphorylation of ERK (IC50, approximately 14 nmol/L). To examine the role of the EGFR in Ang II-mediated phosphorylation of ERK we utilized 100 nmol/L wortmannin to inhibit EGFR signaling to ERK and T19N RhoA to block Ang II-mediated ERK phosphorylation. Wortmannin treatment inhibited EGF-mediated but not Ang II-mediated phosphorylation of ERK. Furthermore, T19N RhoA inhibited Ang II-mediated ERK phosphorylation, whereas T19N RhoA had significantly less effect on EGF-mediated ERK phosphorylation. We conclude that transactivation of the EGFR is not primarily responsible for Ang II-mediated activation of ERK in PGSMCs.

  18. Hydrogen peroxide sensing, signaling and regulation of transcription factors

    Directory of Open Access Journals (Sweden)

    H. Susana Marinho

    2014-01-01

    Full Text Available The regulatory mechanisms by which hydrogen peroxide (H2O2 modulates the activity of transcription factors in bacteria (OxyR and PerR, lower eukaryotes (Yap1, Maf1, Hsf1 and Msn2/4 and mammalian cells (AP-1, NRF2, CREB, HSF1, HIF-1, TP53, NF-κB, NOTCH, SP1 and SCREB-1 are reviewed. The complexity of regulatory networks increases throughout the phylogenetic tree, reaching a high level of complexity in mammalians. Multiple H2O2 sensors and pathways are triggered converging in the regulation of transcription factors at several levels: (1 synthesis of the transcription factor by upregulating transcription or increasing both mRNA stability and translation; (ii stability of the transcription factor by decreasing its association with the ubiquitin E3 ligase complex or by inhibiting this complex; (iii cytoplasm–nuclear traffic by exposing/masking nuclear localization signals, or by releasing the transcription factor from partners or from membrane anchors; and (iv DNA binding and nuclear transactivation by modulating transcription factor affinity towards DNA, co-activators or repressors, and by targeting specific regions of chromatin to activate individual genes. We also discuss how H2O2 biological specificity results from diverse thiol protein sensors, with different reactivity of their sulfhydryl groups towards H2O2, being activated by different concentrations and times of exposure to H2O2. The specific regulation of local H2O2 concentrations is also crucial and results from H2O2 localized production and removal controlled by signals. Finally, we formulate equations to extract from typical experiments quantitative data concerning H2O2 reactivity with sensor molecules. Rate constants of 140 M−1 s−1 and ≥1.3 × 103 M−1 s−1 were estimated, respectively, for the reaction of H2O2 with KEAP1 and with an unknown target that mediates NRF2 protein synthesis. In conclusion, the multitude of H2O2 targets and mechanisms provides an opportunity for

  19. Science Signaling Podcast for 7 June 2016: Modeling signal integration.

    Science.gov (United States)

    Janes, Kevin A; VanHook, Annalisa M

    2016-06-07

    This Podcast features an interview with Kevin Janes, senior author of a Research Article that appears in the 7 June 2016 issue of Science Signaling, about a statistical modeling method that can extract useful information from complex data sets. Cells exist in very complex environments. They are constantly exposed to growth factors, hormones, nutrients, and many other factors that influence cellular behavior. When cells integrate information from multiple stimuli, the resulting output does not necessarily reflect a simple additive effect of the responses to each individual stimulus. Chitforoushzadeh et al employed a statistical modeling approach that maintained the multidimensional nature of the data to analyze the responses of colonic epithelial cells to various combinations of the proinflammatory cytokine TNF, the growth factor EGF, and insulin. As the model predicted, experiments confirmed that insulin suppressed TNF-induced proinflammatory signaling through a mechanism that involved the transcription factor GATA6.Listen to Podcast. Copyright © 2016, American Association for the Advancement of Science.

  20. Transforming Growth FactorSignaling Pathway Activation in Keratoconus

    Science.gov (United States)

    ENGLER, CHRISTOPH; CHAKRAVARTI, SHUKTI; DOYLE, JEFFERSON; EBERHART, CHARLES G.; MENG, HUAN; STARK, WALTER J.; KELLIHER, CLARE; JUN, ALBERT S.

    2011-01-01

    PURPOSE To assess the presence of transforming growth factor-β (TGFβ) pathway markers in the epithelium of keratoconus patient corneas. DESIGN Retrospective, comparative case series of laboratory specimens. METHODS Immunohistochemistry results for TGFβ2, total TGFβ, mothers against decacentaplegic homolog (Smad) 2, and phosphorylated Smad2 was performed on formalin-fixed, paraffin-embedded sections of keratoconus patient corneas and normal corneas from human autopsy eyes. Keratoconus patient corneas were divided in two groups, depending on their severity based on keratometer readings and pachymetry. Autopsy controls were age-matched with the keratoconus cases. Immunohistochemistry signal quantification was performed using automated software. Real-time reverse-transcriptase polymerase chain reaction was performed on total ribonucleic acid of epithelium of keratoconus patient corneas and autopsy control corneas. RESULTS Immunohistochemistry quantification showed a significant increase in mean signal in the group of severe keratoconus cases compared with normal corneas for TGFβ2 and phosphorylated Smad2 (P keratoconus cases versus the autopsy controls. Reverse-transcriptase polymerase chain reaction exhibited elevated messenger ribonucleic acid levels of Smad2 and TGFβ2 in severe keratoconus corneal epithelium. CONCLUSIONS This work shows increased TGFβ pathway markers in severe keratoconus cases and provides the rationale for investigating TGFβ signaling further in the pathophysiology of keratoconus. PMID:21310385

  1. Epidermal Growth Factor Receptor Cell Survival Signaling Requires Phosphatidylcholine Biosynthesis

    Directory of Open Access Journals (Sweden)

    Matt Crook

    2016-11-01

    Full Text Available Identification of pro-cell survival signaling pathways has implications for cancer, cardiovascular, and neurodegenerative disease. We show that the Caenorhabditis elegans epidermal growth factor receptor LET-23 (LET-23 EGFR has a prosurvival function in counteracting excitotoxicity, and we identify novel molecular players required for this prosurvival signaling. uv1 sensory cells in the C. elegans uterus undergo excitotoxic death in response to activation of the OSM-9/OCR-4 TRPV channel by the endogenous agonist nicotinamide. Activation of LET-23 EGFR can effectively prevent this excitotoxic death. We investigate the roles of signaling pathways known to act downstream of LET-23 EGFR in C. elegans and find that the LET-60 Ras/MAPK pathway, but not the IP3 receptor pathway, is required for efficient LET-23 EGFR activity in its prosurvival function. However, activation of LET-60 Ras/MAPK pathway does not appear to be sufficient to fully mimic LET-23 EGFR activity. We screen for genes that are required for EGFR prosurvival function and uncover a role for phosphatidylcholine biosynthetic enzymes in EGFR prosurvival function. Finally, we show that exogenous application of phosphatidylcholine is sufficient to prevent some deaths in this excitotoxicity model. Our work implicates regulation of lipid synthesis downstream of EGFR in cell survival and death decisions.

  2. Polychlorinated Biphenyls Disrupt Hepatic Epidermal Growth Factor Receptor Signaling.

    Science.gov (United States)

    Hardesty, Josiah E; Wahlang, Banrida; Falkner, K Cameron; Clair, Heather B; Clark, Barbara J; Ceresa, Brian P; Prough, Russell A; Cave, Matthew C

    2016-07-26

    1. Polychlorinated biphenyls (PCBs) are persistent environmental pollutants that disrupt hepatic xenobiotic and intermediary metabolism, leading to metabolic syndrome and nonalcoholic steatohepatitis (NASH). 2. Since phenobarbital indirectly activates Constitutive Androstane Receptor (CAR) by antagonizing growth factor binding to the epidermal growth factor receptor (EGFR), we hypothesised that PCBs may also diminish EGFR signaling. 3. The effects of the PCB mixture Aroclor 1260 on the protein phosphorylation cascade triggered by EGFR activation were determined in murine (in vitro and in vivo) and human models (in vitro). EGFR tyrosine residue phosphorylation was decreased by PCBs in all models tested. 4. The IC50 values for Aroclor 1260 concentrations that decreased Y1173 phosphorylation of EGFR were similar in murine AML-12 and human HepG2 cells (∼2-4 μg/mL). Both dioxin and non-dioxin-like PCB congeners decreased EGFR phosphorylation in cell culture. 5. PCB treatment reduced phosphorylation of downstream EGFR effectors including Akt and mTOR, as well as other phosphoprotein targets including STAT3 and c-RAF in vivo. 6. PCBs diminish EGFR signaling in human and murine hepatocyte models and may dysregulate critical phosphoprotein regulators of energy metabolism and nutrition, providing a new mechanism of action in environmental diseases.

  3. Thyroid hormones regulate fibroblast growth factor receptor signaling during chondrogenesis.

    Science.gov (United States)

    Barnard, Joanna C; Williams, Allan J; Rabier, Bénédicte; Chassande, Olivier; Samarut, Jacques; Cheng, Sheue-Yann; Bassett, J H Duncan; Williams, Graham R

    2005-12-01

    Childhood hypothyroidism causes growth arrest with delayed ossification and growth-plate dysgenesis, whereas thyrotoxicosis accelerates ossification and growth. Thyroid hormone (T(3)) regulates chondrocyte proliferation and is essential for hypertrophic differentiation. Fibroblast growth factors (FGFs) are also important regulators of chondrocyte proliferation and differentiation, and activating mutations of FGF receptor-3 (FGFR3) cause achondroplasia. We investigated the hypothesis that T(3) regulates chondrogenesis via FGFR3 in ATDC5 cells, which undergo a defined program of chondrogenesis. ATDC5 cells expressed two FGFR1, four FGFR2, and one FGFR3 mRNA splice variants throughout chondrogenesis, and expression of each isoform was stimulated by T(3) during the first 6-12 d of culture, when T(3) inhibited proliferation by 50%. FGFR3 expression was also increased in cells treated with T(3) for 21 d, when T(3) induced an earlier onset of hypertrophic differentiation and collagen X expression. FGFR3 expression was reduced in growth plates from T(3) receptor alpha-null mice, which exhibit skeletal hypothyroidism, but was increased in T(3) receptor beta(PV/PV) mice, which display skeletal thyrotoxicosis. These findings indicate that FGFR3 is a T(3)-target gene in chondrocytes. In further experiments, T(3) enhanced FGF2 and FGF18 activation of the MAPK-signaling pathway but inhibited their activation of signal transducer and activator of transcription-1. FGF9 did not activate MAPK or signal transducer and activator of transcription-1 pathways in the absence or presence of T(3). Thus, T(3) exerted differing effects on FGFR activation during chondrogenesis depending on which FGF ligand stimulated the FGFR and which downstream signaling pathway was activated. These studies identify novel interactions between T(3) and FGFs that regulate chondrocyte proliferation and differentiation during chondrogenesis.

  4. Effects of EGF and TGF-alpha on invasion and proteinase expression of uterine cervical adenocarcinoma OMC-4 cells.

    Science.gov (United States)

    Ueda, M; Fujii, H; Yoshizawa, K; Terai, Y; Kumagai, K; Ueki, K; Ueki, M

    Uterine cervical adenocarcinoma typically is an aggressive neoplasm with a propensity for early invasion and dissemination; however, the regulatory mechanism of invasive activity of cervical adenocarcinoma cells has not been fully understood. In this study, biological effects of epidermal growth factor (EGF) and transforming growth factor (TGF)-alpha on invasion and proteinase expression of human cervical adenocarcinoma OMC-4 cells were investigated. Tumor cell migration along a gradient of substratum-bound fibronectin and invasion into the reconstituted basement membrane were stimulated by 0.1-10 nM EGF and TGF-alpha in a concentration-dependent manner. Their effects on tumor cell migration were also confirmed by wound assay. The zymography of tumor-conditioned medium showed that the treatment of OMC-4 cells with EGF and TGF-alpha resulted in the increase of matrix metalloproteinase (MMP)-2 and urokinase-type plasminogen activator (uPA). Matrilysin (MMP-7), also secreted by OMC-4 cells, was not affected by these growth factors. These results suggest that EGF and TGF-alpha act as positive regulators on the invasion of cervical adenocarcinoma cells, which may be associated with their stimulatory effects on tumor cell motility and the induction of type IV collagenase and uPA secreted by tumor cells.

  5. Regulation of macrophage inhibitory factor (MIF) by epidermal growth factor receptor (EGFR) in the MCF10AT model of breast cancer progression.

    Science.gov (United States)

    Lim, Simin; Choong, Lee-Yee; Kuan, Chong Poh; Yunhao, Chen; Lim, Yoon-Pin

    2009-08-01

    Genetic aberration of EGFR is one of the major molecular characteristics of breast cancer. However, the molecular changes associated with EGFR signaling during different stages of breast cancer development have not been studied. In this study, complementary two-dimensional-DIGE and iTRAQ technologies were used to profile the expression level of proteins in 4 isogenic cell lines in the MCF10AT model of breast cancer progression following a time course of EGF stimulation. A total of 80 proteins (67 from iTRAQ, 15 from DIGE, 2 common in both) were identified to be up- or down-regulated by EGF treatment. Following EGF stimulation, the expression level of MIF, a cytokine that has been implicated in many human cancers, was decreased in MCF10A1 normal breast mammary epithelial cells, increased in MCF10AT1k preneoplastic and MCF10CA1h low grade breast cancer cells, but showed no obvious difference in the MCF10CA1a high grade cancer cells. The increase in MIF expression level following EGF treatment could also be observed in A431 cervical cancer cells. EGF-induced increases of MIF expression levels in CA1h breast cancer cells were abrogated when MEK, but not PIK3CA, was knocked down. In addition, silencing of MIF diminished the proliferation of EGF-stimulated CA1h cells when compared to control cells. Taken together, our data suggested an EGFR --> MEK --> MIF proliferative pathway that has never been reported previously and that this pathway "evolves" during disease progression as modeled by the MCF10AT system. Revelation of the novel relationship between MIF and EGF may contribute to an integrated understanding of the roles of these oncogenic factors during breast cancer development.

  6. Real-time studies of the interactions between epidermal growth factor and its receptor during endocytic trafficking.

    Science.gov (United States)

    Martin-Fernandez, M L; Clarke, D T; Tobin, M J; Jones, G R

    2000-09-01

    The interactions of growth factors with cell surface receptors regulate fundamental cell processes, such as growth, differentiation and transformation. Understanding the nature of these interactions at the molecular level is of fundamental importance in cell biology. This is not only from the point of view of basic science, but also because of the repercussions such knowledge might have in understanding the mode of action of drugs in cells. Receptor mediated endocytosis has been implicated in the downregulation of the mitogenic signal. However, no data are thus far available on how growth factor/receptor interactions might control endocytic trafficking. Here we show that information on modes of binding and receptor conformational changes can be obtained using time-resolved fluorescence methods. We have found that fluorescent probes bound to epidermal growth factor (EGF) show dynamic fluorescence quenching when EGF is bound to internalising EGF receptors (EGFR). We propose that this dynamic quenching takes place because EGF-bound probes interact with tryptophan residues in the extracellular domain of the EGF-EGFR complex. Real-time accumulation of fluorescent decays has also allowed us to follow the time course of a conformational change in EGFR occurring during endocytosis, and correlate this information with endosomal trafficking and EGFR recycling.

  7. EGF-induced expansion of migratory cells in the rostral migratory stream.

    Directory of Open Access Journals (Sweden)

    Olle R Lindberg

    Full Text Available The presence of neural stem cells in the adult brain is currently widely accepted and efforts are made to harness the regenerative potential of these cells. The dentate gyrus of the hippocampal formation, and the subventricular zone (SVZ of the anterior lateral ventricles, are considered the main loci of adult neurogenesis. The rostral migratory stream (RMS is the structure funneling SVZ progenitor cells through the forebrain to their final destination in the olfactory bulb. Moreover, extensive proliferation occurs in the RMS. Some evidence suggest the presence of stem cells in the RMS, but these cells are few and possibly of limited differentiation potential. We have recently demonstrated the specific expression of the cytoskeleton linker protein radixin in neuroblasts in the RMS and in oligodendrocyte progenitors throughout the brain. These cell populations are greatly altered after intracerebroventricular infusion of epidermal growth factor (EGF. In the current study we investigate the effect of EGF infusion on the rat RMS. We describe a specific increase of radixin(+/Olig2(+ cells in the RMS. Negative for NG2 and CNPase, these radixin(+/Olig2(+ cells are distinct from typical oligodendrocyte progenitors. The expanded Olig2(+ population responds rapidly to EGF and proliferates after only 24 hours along the entire RMS, suggesting local activation by EGF throughout the RMS rather than migration from the SVZ. In addition, the radixin(+/Olig2(+ progenitors assemble in chains in vivo and migrate in chains in explant cultures, suggesting that they possess migratory properties within the RMS. In summary, these results provide insight into the adaptive capacity of the RMS and point to an additional stem cell source for future brain repair strategies.

  8. Wound dressing composed of hyaluronic acid and collagen containing EGF or bFGF: comparative culture study.

    Science.gov (United States)

    Yu, Akane; Niiyama, Hayato; Kondo, Shinya; Yamamoto, Akiko; Suzuki, Ryusuke; Kuroyanagi, Yoshimitsu

    2013-01-01

    We developed a novel wound dressing composed of a hyaluronic acid (HA) and collagen (Col) spongy sheet containing epidermal growth factor (EGF) or basic fibrolast growth factor (bFGF) by freeze-drying method (EGF-wound dressing or bFGF-wound dressing, respectively). A wound dressing without any growth factor was prepared as a control in a similar manner as above (C-wound dressing). Intermolecular cross-linkage between Col molecules was induced by UV irradiation. The release behavior of free HA from the wound dressing was investigated using a C-wound dressing. The weight of C-wound dressing after 1 day, 3, 5, and 7 days of incubation on top of a Col gel sheet at the air-water interface (wound surface model) was 55, 36, 30, and 19% of the original weight, respectively. Most free HA and a part of Col was released from the cross-linked Col network in the wound dressing during incubation, as the original Col content in the wound dressing was 33%. Next, fibroblast proliferation was assessed in conventional culture medium preconditioned by immersion of a piece of C-, EGF-, or bFGF-wound dressing, i.e. C-conditioned medium, EGF-conditioned medium, or bFGF-conditioned medium. Cell proliferation in C-conditioned medium increased to approximately the same level as that in conventional medium. Cell proliferation in EGF- and bFGF-conditioned medium was 1.9 times and 2.6 times greater than that in conventional medium after 7 days of cultivation, respectively. Finally, cytokine production of fibroblasts was assessed in a wound surface model using a fibroblast-incorporating Col gel sheet (cultured dermal substitute [CDS]). CDS was elevated to the air-medium interface, on which each wound dressing was placed and cultured for 7 days. Fibroblasts in CDS covered with EGF-wound dressing released 3.6 times more vascular endothelial growth factor (VEGF) and 4.6 times more hepatocyte growth factor (HGF) when compared with the C-wound dressing. Fibroblasts in CDS covered with b

  9. Role of extracellular signal-regulated kinase in regulating expression of interleukin 13 in lymphocytes from an asthmatic rat model

    Institute of Scientific and Technical Information of China (English)

    LI Yuan-yuan; LIU Xian-sheng; LIU Chang; XU Yong-jian; XIONG Wei-xing

    2010-01-01

    Background The extracellular signal-regulated kinase (ERK) is widely expressed in mammal cells and involved in airway proliferation and remodeling in asthma. In this study, we intend to explore the role of ERK in the expression of the Th2 cytokine, interleukin 13 (IL-13) in lymphocytes in asthma.Methods Forty Sprague-Dawley rats were randomly divided into two groups: normal control and asthmatic groups. Peripheral blood lymphocytes were isolated and purified from the blood of each rat and divided into five groups: control, asthmatic lymphocytes, asthmatic cells stimulated with ERK activator epidermal growth factor (EGF), or with ERK inhibitor PD98059, or with EGF and PD98059 together. The expression of phosphorylated-ERK (p-ERK) was observed by immunocvtochemical staining, the expression of ERK mRNA was determined by reverse transcriptase-PCR, IL-13 protein in supernatants was measured by ELISA.Results (1) The ERK mRNA level and the percentage of cells with p-ERK in lymphocytes from asthmatic rats were significantly higher than those in normal controls, and were significantly increased by EGF administration. This effect of EGF was significantly inhibited by PD98059 pretreatment. (2) IL-13 protein in supematants of asthmatic lymphocytes was higher than that produced by normal control lymphocytes, and was significantly increased by EGF treatment. This EGF effect was partly blocked by PD98059 pretreatment. (3) There was a significant positive correlation between the percentage of cells with p-ERK in peripheral blood lymphocytes and IL-13 protein in supematants of lymphocytes from asthmatic rats.Conclusions In asthma the ERK expression and activation levels were increased, as was the protein level of IL-13. The ERK signaling pathway may be involved in the increased expression of the Th2 cytokine IL-13 in asthma.

  10. Segment boundaries of the adult rat epididymis limit interstitial signaling by potential paracrine factors and segments lose differential gene expression after efferent duct ligation

    Institute of Scientific and Technical Information of China (English)

    Terry T. Turner; Daniel S. Johnston; Scott A. Jelinsky; Jose L. Tomsig; Joshua N. Finger

    2007-01-01

    The epididymis is divided into caput, corpus and cauda regions, organized into intraregional segments separated by connective tissue septa (CTS). In the adult rat and mouse these segments are highly differentiated. Regulation of these segments is by endocrine, lumicrine and paracrine factors, the relative importance of which remains under investigation. Here, the ability of the CTS to limit signaling in the interstitial compartment is reviewed as is the effect of 15 days of unilateral efferent duct ligation (EDL) on ipsilateral segmental transcriptional profiles. Inter-segmental microperifusions of epidermal growth factor (EGF), vascular endothelial growth factor (VEGFA) and fibroblast growth factor 2 (FGF2) increased phosphorylation of mitogen activated protein kinase (MAPK) in segments 1 and 2 of the rat epididymis and the effects of all factors were limited by the CTS separating the segments. Microarray analysis of segmental gene expression determined the effect of 15 days of unilateral EDL on the transcriptome-wide gene expression of rat segments 1-4. Over 11 000 genes were expressed in each of the four segments and over 2 000 transcripts in segment 1 responded to deprivation of testicular lumicrine factors. Segments 1 and 2 of control tissues were the most transcriptionally different and EDL had its greatest effects there. In the absence of lumicrine factors, all four segments regressed to a transcriptionally undifferentiated state, consistent with the less differentiated histology. Deprivation of lumicrine factors could stimulate an individual gene's expression in some segments yet suppress it in others. Such results reveal a higher complexity of the regulation of rat epididymal segments than that is generally appreciated.

  11. CysLT1 receptor-induced human airway smooth muscle cells proliferation requires ROS generation, EGF receptor transactivation and ERK1/2 phosphorylation

    Directory of Open Access Journals (Sweden)

    Capra Valérie

    2006-03-01

    Full Text Available Abstract Background Cysteine-containing leukotrienes (cysteinyl-LTs are pivotal inflammatory mediators that play important roles in the pathophysiology of asthma, allergic rhinitis, and other inflammatory conditions. In particular, cysteinyl-LTs exert a variety of effects with relevance to the aetiology of asthma such as smooth muscle contraction, eosinophil recruitment, increased microvascular permeability, enhanced mucus secretion and decreased mucus transport and, finally, airway smooth muscle cells (ASMC proliferation. We used human ASMC (HASMC to identify the signal transduction pathway(s of the leukotriene D4 (LTD4-induced DNA synthesis. Methods Proliferation of primary HASMC was measured by [3H]thymidine incorporation. Phosphorylation of EGF receptor (EGF-R and ERK1/2 was assessed with a polyclonal anti-EGF-R or anti-phosphoERKl/2 monoclonal antibody. A Ras pull-down assay kit was used to evaluate Ras activation. The production of reactive oxygen species (ROS was estimated by measuring dichlorodihydrofluorescein (DCF oxidation. Results We demonstrate that in HASMC LTD4-stimulated thymidine incorporation and potentiation of EGF-induced mitogenic signaling mostly depends upon EGF-R transactivation through the stimulation of CysLT1-R. Accordingly, we found that LTD4 stimulation was able to trigger the increase of Ras-GTP and, in turn, to activate ERK1/2. We show here that EGF-R transactivation was sensitive to pertussis toxin (PTX and phosphoinositide 3-kinase (PI3K inhibitors and that it occurred independently from Src activity, despite the observation of a strong impairment of LTD4-induced DNA synthesis following Src inhibition. More interestingly, CysLT1-R stimulation increased the production of ROS and N-acetylcysteine (NAC abolished LTD4-induced EGF-R phosphorylation and thymidine incorporation. Conclusion Collectively, our data demonstrate that in HASMC LTD4 stimulation of a Gi/o coupled CysLT1-R triggers the transactivation of the EGF

  12. CysLT1 receptor-induced human airway smooth muscle cells proliferation requires ROS generation, EGF receptor transactivation and ERK1/2 phosphorylation.

    Science.gov (United States)

    Ravasi, Saula; Citro, Simona; Viviani, Barbara; Capra, Valérie; Rovati, G Enrico

    2006-03-22

    Cysteine-containing leukotrienes (cysteinyl-LTs) are pivotal inflammatory mediators that play important roles in the pathophysiology of asthma, allergic rhinitis, and other inflammatory conditions. In particular, cysteinyl-LTs exert a variety of effects with relevance to the aetiology of asthma such as smooth muscle contraction, eosinophil recruitment, increased microvascular permeability, enhanced mucus secretion and decreased mucus transport and, finally, airway smooth muscle cells (ASMC) proliferation. We used human ASMC (HASMC) to identify the signal transduction pathway(s) of the leukotriene D4 (LTD4)-induced DNA synthesis. Proliferation of primary HASMC was measured by [3H]thymidine incorporation. Phosphorylation of EGF receptor (EGF-R) and ERK1/2 was assessed with a polyclonal anti-EGF-R or anti-phosphoERKl/2 monoclonal antibody. A Ras pull-down assay kit was used to evaluate Ras activation. The production of reactive oxygen species (ROS) was estimated by measuring dichlorodihydrofluorescein (DCF) oxidation. We demonstrate that in HASMC LTD4-stimulated thymidine incorporation and potentiation of EGF-induced mitogenic signaling mostly depends upon EGF-R transactivation through the stimulation of CysLT1-R. Accordingly, we found that LTD4 stimulation was able to trigger the increase of Ras-GTP and, in turn, to activate ERK1/2. We show here that EGF-R transactivation was sensitive to pertussis toxin (PTX) and phosphoinositide 3-kinase (PI3K) inhibitors and that it occurred independently from Src activity, despite the observation of a strong impairment of LTD4-induced DNA synthesis following Src inhibition. More interestingly, CysLT1-R stimulation increased the production of ROS and N-acetylcysteine (NAC) abolished LTD4-induced EGF-R phosphorylation and thymidine incorporation. Collectively, our data demonstrate that in HASMC LTD4 stimulation of a Gi/o coupled CysLT1-R triggers the transactivation of the EGF-R through the intervention of PI3K and ROS. While PI3K

  13. Transcription factors and target genes of pre-TCR signaling.

    Science.gov (United States)

    López-Rodríguez, Cristina; Aramburu, Jose; Berga-Bolaños, Rosa

    2015-06-01

    Almost 30 years ago pioneering work by the laboratories of Harald von Boehmer and Susumo Tonegawa provided the first indications that developing thymocytes could assemble a functional TCRβ chain-containing receptor complex, the pre-TCR, before TCRα expression. The discovery and study of the pre-TCR complex revealed paradigms of signaling pathways in control of cell survival and proliferation, and culminated in the recognition of the multifunctional nature of this receptor. As a receptor integrated in a dynamic developmental process, the pre-TCR must be viewed not only in the light of the biological outcomes it promotes, but also in context with those molecular processes that drive its expression in thymocytes. This review article focuses on transcription factors and target genes activated by the pre-TCR to drive its different outcomes.

  14. Overcoming acquired drug resistance in colorectal cancer cells by targeted delivery of 5-FU with EGF grafted hollow mesoporous silica nanoparticles

    Science.gov (United States)

    Chen, Lijue; She, Xiaodong; Wang, Tao; He, Li; Shigdar, Sarah; Duan, Wei; Kong, Lingxue

    2015-08-01

    Acquired drug resistance (ADR) can be developed in colorectal cancer cells after 5-fluorouracil (5-FU) treatment and diminish the effectiveness of chemotherapy. In this work, acquired 5-FU resistance in the colorectal cancer cell line SW480 was obtained with the up-regulation of dihydropyrimidine dehydrogenase (DPYD) gene expression which can convert 5-FU to its inactive metabolite. To overcome ADR in colorectal cancer, hollow mesoporous silica nanoparticles (HMSNs) grafted with epidermal growth factor (EGF) were used as nanocarriers to deliver 5-FU to colorectal cancer cells with acquired drug resistance. The effect and mechanism of 5-FU loaded EGF grafted HMSNs (EGF-HMSNs-5-FU) in overcoming acquired drug resistance in SW480/ADR cells were studied. The EGF-HMSNs were demonstrated to be specifically internalized in EGFR overexpressed SW480/ADR cells via a receptor-mediated endocytosis and can escape from endo-lysosomes. The EGF-HMSNs-5-FU exhibited much higher cytotoxicity on SW480/ADR cells than HMSNs-5-FU and free 5-FU while the plain HMSNs did not show significant cytotoxicity. The mechanism of EGF-HMSNs-5-FU in overcoming drug resistance in SW480/ADR cells could be attributed to the specific internalization of EGF-HMSNs-5-FU in EGFR overexpressed cells which can lead to high intracellular drug accumulation and cause cell death through S phase arrest.Acquired drug resistance (ADR) can be developed in colorectal cancer cells after 5-fluorouracil (5-FU) treatment and diminish the effectiveness of chemotherapy. In this work, acquired 5-FU resistance in the colorectal cancer cell line SW480 was obtained with the up-regulation of dihydropyrimidine dehydrogenase (DPYD) gene expression which can convert 5-FU to its inactive metabolite. To overcome ADR in colorectal cancer, hollow mesoporous silica nanoparticles (HMSNs) grafted with epidermal growth factor (EGF) were used as nanocarriers to deliver 5-FU to colorectal cancer cells with acquired drug resistance. The

  15. Spatial signalling mediated by the transforming growth factorsignalling pathway during tooth formation.

    Science.gov (United States)

    He, Xin-Yu; Sun, Ke; Xu, Ruo-Shi; Tan, Jia-Li; Pi, Cai-Xia; Wan, Mian; Peng, Yi-Ran; Ye, Ling; Zheng, Li-Wei; Zhou, Xue-Dong

    2016-12-16

    Tooth development relies on sequential and reciprocal interactions between the epithelial and mesenchymal tissues, and it is continuously regulated by a variety of conserved and specific temporal-spatial signalling pathways. It is well known that suspensions of tooth germ cells can form tooth-like structures after losing the positional information provided by the epithelial and mesenchymal tissues. However, the particular stage in which the tooth germ cells start to form tooth-like structures after losing their positional information remains unclear. In this study, we investigated the reassociation of tooth germ cells suspension from different morphological stages during tooth development and the phosphorylation of Smad2/3 in this process. Four tooth morphological stages were designed in this study. The results showed that tooth germ cells formed odontogenic tissue at embryonic day (E) 14.5, which is referred to as the cap stage, and they formed tooth-like structures at E16.5, which is referred to as the early bell stage, and E18.5, which is referred to as the late bell stage. Moreover, the transforming growth factorsignalling pathway might play a role in this process.

  16. Cell model for the study of receptor and regulatory functions of human proHB-EGF

    Directory of Open Access Journals (Sweden)

    N. V. Korotkevych

    2014-08-01

    Full Text Available Developing of new models and approaches, particularly with fluorescent techniques, for investigation of intracellular transport of proHB-EGF and its ligand-receptor complexes is strongly required. In order to create a model for studying proHB-EGF functions the genetic construction pEGFP-N1-proHB-EGF, encoding proHB-EGF-EGFP which is fluorescent-labeled form of proHB-EGF with enhanced green fluorescent protein EGFP in the cytoplasmic terminus of the molecule, was obtained. Eukaryotic cells expressing fusion protein proHB-EGF-EGFP on the cell surface were obtained by transfection with pEGFP-N1-proHB-EGF. Expressed in the Vero cells proHB-EGF-EGFP could bind fluorescent derivative of nontoxic receptor-binding subunit B of diphtheria toxin mCherry-SubB. After stimulation of transfected cells with TPA (12-O-Tetradecanoylphorbol-13-acetate, proHB-EGF-EGFP formed a fluorescentl-labeled C-terminal fragment of the molecule – CTF-EGFP. Thus, the obtained genetic construction pEGFP-N1-proHB-EGF could be helpful in visualization of molecules proHB-EGF and CTF in cells, may open new possibilities for the studying of their functions, such as receptor function of proHB-EGF for diphtheria toxin, intracellular translocation of CTF and provide possibilities for natural proHB-EGF ligands search.

  17. Coagulation factor V mediates inhibition of tissue factor signaling by activated protein C in mice.

    Science.gov (United States)

    Liang, Hai Po H; Kerschen, Edward J; Basu, Sreemanti; Hernandez, Irene; Zogg, Mark; Jia, Shuang; Hessner, Martin J; Toso, Raffaella; Rezaie, Alireza R; Fernández, José A; Camire, Rodney M; Ruf, Wolfram; Griffin, John H; Weiler, Hartmut

    2015-11-19

    The key effector molecule of the natural protein C pathway, activated protein C (aPC), exerts pleiotropic effects on coagulation, fibrinolysis, and inflammation. Coagulation-independent cell signaling by aPC appears to be the predominant mechanism underlying its highly reproducible therapeutic efficacy in most animal models of injury and infection. In this study, using a mouse model of Staphylococcus aureus sepsis, we demonstrate marked disease stage-specific effects of the anticoagulant and cell signaling functions of aPC. aPC resistance of factor (f)V due to the R506Q Leiden mutation protected against detrimental anticoagulant effects of aPC therapy but also abrogated the anti-inflammatory and mortality-reducing effects of the signaling-selective 5A-aPC variant that has minimal anticoagulant function. We found that procofactor V (cleaved by aPC at R506) and protein S were necessary cofactors for the aPC-mediated inhibition of inflammatory tissue-factor signaling. The anti-inflammatory cofactor function of fV involved the same structural features that govern its cofactor function for the anticoagulant effects of aPC, yet its anti-inflammatory activities did not involve proteolysis of activated coagulation factors Va and VIIIa. These findings reveal a novel biological function and mechanism of the protein C pathway in which protein S and the aPC-cleaved form of fV are cofactors for anti-inflammatory cell signaling by aPC in the context of endotoxemia and infection.

  18. EFFECT OF ELECTROACUPUNCTURE OF ZUSANLI ON PLASMA EGF, CGRP AND GASTRIC MUCOSA IN STRESS RATS

    Institute of Scientific and Technical Information of China (English)

    秦明; 黄裕新; 王景杰; 赵保民; 高巍; 王庆莉

    2001-01-01

    Objective: To study the effect of electroacupuncture(EA) of Zusanli (ST 36) on plasma epidermal growth factor (EGF) and celcitonin gene-related peptide (CGRP) levels in stress rats. Methods: 40 Wistar rats were randomly divided into control group (n = 8) which was not given with either stress or EA; stress group (n = 8 ) which was given only with stress stimulation, and EA plus stress group (divided into 3 subgroups 1-d, 3-d and 5-d according to the EA treatment duration 1 day, 3 days and 5 days, with 8 rats being in each subgroup). The restrained-cold stress method was used for making stress animal model. Under light microscope and transmission electron microscope, the structural changes of the gastric mucosa were observed. By radioimmunoassay and Guth methods, plasma EGF and CGRP contents and the related ulcer index (UI) were analyzed. Results: In comparison with control group, plasma EGF of stress group decreased significantly (0.44±0.16 μg/L vs 0.23±0.01 μg/L, P < 0.05) ; while UI increased considerably (1.10±0.40 vs 28.0±4.1, P < 0.01). Compared with stress group, both plasma EGF and plasma CGRP in EA subgroup-1d increased significantly (0.23±0.01 μg/L vs 0.42±0.09 μg/L, P < 0.05; 145.00±6.00 ng/L vs 184.00±22.00 ng/L, P<0.05 respectively) ; while UI lowered obviously (28.00±4.10 vs 19.00±2.30, P<0.01 ). Plasma CGRP content of subgroup-5d increased significantly in comparison with that of subgroup-1d ( 184.00±22.00 ng/L vs 232.00±35.00 ng/L, P<0.01). Compared with EA group, the degrees of necrosis and damages of the mucosal cells and vascular endothelium were more severe in stress group. Conclusion: EA of Zusanli (ST 36) can protect gastric mucosa from injury in stress rats, in which the periphery EGF and CGRP are involved and the regulatory action of EA on plasma CGRP is also related to the treatment duration.

  19. Fibroblast Growth Factors and Epidermal Growth Factor Cooperate with Oocyte-Derived Members of the TGFbeta Superfamily to Regulate Spry2 mRNA Levels in Mouse Cumulus Cells1

    Science.gov (United States)

    Sugiura, Koji; Su, You-Qiang; Li, Qinglei; Wigglesworth, Karen; Matzuk, Martin M.; Eppig, John J.

    2009-01-01

    Mouse oocytes produce members of the transforming growth factor beta (TGFbeta) superfamily, including bone morphogenetic protein 15 (BMP15) and growth differentiation factor 9 (GDF9), as well as fibroblast growth factors (FGFs). These growth factors cooperate to regulate cumulus cell function. To identify potential mechanisms involved in these interactions, the ability of fully grown oocytes to regulate expression of BMP or FGF antagonists in cumulus cells was examined. Oocytes promoted cumulus cell expression of transcripts encoding antagonists to TGFbeta superfamily members, including Grem2, Htra1, Htra3, and Nog mRNAs. In contrast, oocytes suppressed cumulus cell expression of Spry2 mRNA, which encodes a regulator of receptor tyrosine kinase signals, such as FGF and epidermal growth factor (EGF) receptor signals. The regulation of Spry2 mRNA levels in cumulus cells was studied further as a model for analysis of potential mechanisms for cooperativity of FGF/EGF signaling with oocyte-derived members of the TGFbeta superfamily. Oocytes suppressed basal and FGF-stimulated Spry2 mRNA levels in cumulus cells but promoted EGF-stimulated levels. Furthermore, recombinant TGFbeta superfamily proteins, including BMP15 and GDF9, mimicked these effects of oocytes. Elevated expression of Spry2 mRNA in cumulus and mural granulosa cells correlated with human chorionic gonadotropin-induced expression of mRNAs encoding EGF-like peptides. Therefore, oocyte-derived members of the TGFbeta superfamily suppress FGF-stimulated Spry2 mRNA levels before the luteinizing hormone surge but promote Spry2 mRNA levels stimulated by EGF receptor-mediated signals after the surge. PMID:19553596

  20. Preparation and evaluation of (68)Ga-DOTA-hEGF for visualization of EGFR expression in malignant tumors.

    Science.gov (United States)

    Velikyan, Irina; Sundberg, Asa Liljegren; Lindhe, Orjan; Höglund, A Urban; Eriksson, Olof; Werner, Eva; Carlsson, Jorgen; Bergström, Mats; Långström, Bengt; Tolmachev, Vladimir

    2005-11-01

    Detection of epidermal growth factor receptor (EGFR) overexpression in many carcinomas provides important diagnostic information, which can influence patient management. The use of PET may enable such detection in vivo by a noninvasive procedure with high sensitivity. The aim of this study was to develop a method for preparation of a positron-emitting tracer based on a natural ligand to EGFR, the recombinant human epidermal growth factor (hEGF), and to perform a preclinical evaluation of the tracer. DOTA-hEGF (DOTA is 1,4,7,10-tetraazacyclododecane-N,N',N'',N'''-tetraacetic acid) was prepared by coupling of a N-sulfosuccinimide ester of DOTA to hEGF. The conjugate was labeled with a generator-produced positron-emitting nuclide, (68)Ga (half-life = 68 min), using microwave heating. Binding specificity, affinity, internalization, and retention of (68)Ga-DOTA-hEGF was studied in 2 EGFR-expressing cell lines, U343 glioma cells and A431 cervical carcinoma cells. Biodistribution and microPET visualization studies were performed in BALB/c nu/nu mice bearing A431 carcinoma xenografts. A 1-min-long microwave-assisted labeling provided radioactivity incorporation of 77% +/- 4%. Both cell lines demonstrated receptor-specific uptake of the conjugate, rapid internalization of the tracer, and good retention of radioactivity. Binding to both cell lines occurred with high affinity, approximately 2 nmol/L. The biodistribution study demonstrated accumulation of radioactivity in xenografts and in EGFR-expressing organs. The microPET imaging study enabled visualization of tumors and demonstrated quick--within 5 min--localization of radioactivity in tumors. (68)Ga-DOTA-hEGF has potential for imaging EGFR overexpression in tumors.

  1. Chronic treatment with epidermal growth factor causes esophageal epithelial hyperplasia in pigs and rats

    DEFF Research Database (Denmark)

    Juhl, C O; Vinter-Jensen, Lars; Poulsen, Steen Seier;

    1995-01-01

    Epidermal growth factor (EGF) is an important factor for maintaining the esophageal functional integrity. Goettingen minipigs were treated with either placebo or subcutaneous EGF (30 micrograms/kg/day) for four weeks. Wistar rats were treated with either placebo or subcutaneous EGF (150 microgram...

  2. Systemic treatment with epidermal growth factor in pigs induces ductal proliferations in the pancreas

    DEFF Research Database (Denmark)

    Vinter-Jensen, Lars; Juhl, C O; Teglbjaerg, P S;

    1997-01-01

    Epidermal growth factor (EGF), transforming growth factor alpha (TGF-alpha), and the EGF receptor are often overexpressed in chronic pancreatitis and in malignant pancreatic growth. Transgenic mice overexpressing TGF-alpha develop tissue changes in the pancrease resembling changes found in chronic...... pancreatitis. The effects of systemic treatment with EGF on the porcine pancrease were investigated in this study....

  3. Synergism between Hedgehog-GLI and EGFR signaling in Hedgehog-responsive human medulloblastoma cells induces downregulation of canonical Hedgehog-target genes and stabilized expression of GLI1.

    Directory of Open Access Journals (Sweden)

    Frank Götschel

    Full Text Available Aberrant activation of Hedgehog (HH signaling has been identified as a key etiologic factor in many human malignancies. Signal strength, target gene specificity, and oncogenic activity of HH signaling depend profoundly on interactions with other pathways, such as epidermal growth factor receptor-mediated signaling, which has been shown to cooperate with HH/GLI in basal cell carcinoma and pancreatic cancer. Our experimental data demonstrated that the Daoy human medulloblastoma cell line possesses a fully inducible endogenous HH pathway. Treatment of Daoy cells with Sonic HH or Smoothened agonist induced expression of GLI1 protein and simultaneously prevented the processing of GLI3 to its repressor form. To study interactions between HH- and EGF-induced signaling in greater detail, time-resolved measurements were carried out and analyzed at the transcriptomic and proteomic levels. The Daoy cells responded to the HH/EGF co-treatment by downregulating GLI1, PTCH, and HHIP at the transcript level; this was also observed when Amphiregulin (AREG was used instead of EGF. We identified a novel crosstalk mechanism whereby EGFR signaling silences proteins acting as negative regulators of HH signaling, as AKT- and ERK-signaling independent process. EGFR/HH signaling maintained high GLI1 protein levels which contrasted the GLI1 downregulation on the transcript level. Conversely, a high-level synergism was also observed, due to a strong and significant upregulation of numerous canonical EGF-targets with putative tumor-promoting properties such as MMP7, VEGFA, and IL-8. In conclusion, synergistic effects between EGFR and HH signaling can selectively induce a switch from a canonical HH/GLI profile to a modulated specific target gene profile. This suggests that there are more wide-spread, yet context-dependent interactions, between HH/GLI and growth factor receptor signaling in human malignancies.

  4. 人egf基因在突变枯草芽孢杆菌WYBS2001中的转化、分泌表达及其产物功能研究%Transforming and Secreting Expression of Human egf in Mutant Strain WYBS2001 of Bacillas and Its Functions

    Institute of Scientific and Technical Information of China (English)

    王关林; 易庆; 方宏筠

    2003-01-01

    通过紫外线突变诱导获得了对感染致病菌具有显著抑菌作用的枯草芽孢杆菌突变株WYBS2001.采用PCR技术人工合成了175 bp的人表皮生长因子(hEGF)的基因片段,并引入Pst Ⅰ、HindⅢ酶切位点、起始密码子及pUS186载体信号肽序列CTTAGA.经DNA测序分析,合成的片段与人egf基因序列完全一致.然后将其克隆至枯草杆菌分泌型质粒载体pUS186上构建成重组质粒pUSE,并转化枯草杆菌突变菌株WYBS2001,获得转人egf基因的枯草杆菌生态工程菌WYBS2001T.RIA检测结果表明,WYBS2001T阳性工程菌培养的上清液中可检测到hEGF,含量为7.6 ng/ml.如果培养液中添加蛋白酶抑制剂可提高hEGF检测量.通过多代的培养仍然能够稳定地分泌表达hEGF.生物学功能实验表明,分泌的hEGF对人K562体外培养细胞的增殖和生长具有明显生物学活性.对烧伤动物模型的功能性实验观察到,WYBS2001T工程菌制剂对动物的烧伤有明显的治疗作用.该研究表明,微生态基因工程菌有很好的应用前景.%Mutant strain WYBS2001 of B. subtilis with strong anti-pathgenic activity was obtained by mutagenic ultraviolet rays. The gene fragment of Human Epidermal Growth Factor(hegf) of 175 bp was synthesized by PCR and the restriction sites Pst Ⅰ and Hind Ⅲ , original code and the signal sequence CTTAGA of secreting vector pUS186 were induced in the fragment. The DNA sequencing result revealed that the synthesized fragment was identical with that of human egf. Then the biological engineering strain WYBS2001T with human egf was obtained by transforming pUSE which was constructed by cloning egf into the secreting plasmid pUS186, into mutant strain WYBS2001. The result of RIA showed that hEGF can be found in the supernatant of the cultures and its content was 7.6 ng/ml. And the content can be increased if the proteinase inhibitor was added into the medium. After several generations' culturing, WYBS2001T positive

  5. 雌激素剥夺状态下表皮生长因子信号系统在内异症发病中的作用%Role of epidermal growth factor signaling system in the pathogenesis of endometriosis under estrogen deprivation conditions

    Institute of Scientific and Technical Information of China (English)

    王宇全; 尹利荣; 郭蕊萌; 盛威

    2013-01-01

    .030,两组比较,差异无统计学意义(P>0.05).(2)蛋白表达水平:①体外实验中,EGF组p-ERK1/2的蛋白表达水平为0.670±0.020,空白对照组为0.600±0.010,两组比较,差异有统计学意义(P<0.05);EGF+PD98059组为0.610±0.020,与空白对照组比较,差异无统计学意义(P>0.05).②体内实验中,在造模后4、6、8周,去势组和对照组裸鼠腹腔异位病灶中EGF蛋白表达水平分别为(0.530±0.015和0.610±0.015)、(0.400±0.029和0.620±0.018)、(0.560±0.026和0.630±0.021);EGFR蛋白表达水平分别为(0.500±0.030和0.640±0.030)、(0.470±0.020和0.630±0.020)、(0.510±0.030和0.610±0.020);p-ERK1/2蛋白表达水平分别为(0.500±0.020和0.580±0.020)、(0.490±0.020和0.580±0.020)、(0.570±0.020和0.590±0.020);两组在各个时间点EGF、EGFR、p-ERK1/2蛋白表达水平比较,差异均有统计学意义(P<0.01,P<0.01,P<0.05);在造模后10周,去势组和对照组EGF的蛋白表达水平为(0.620±0.020和0.620±0.020),EGFR为(0.610±0.020和0.610±0.020),p-ERK1/2为(0.590±0.010和0.600±0.020),两组比较,差异均无统计学意义(P>0.05).结论 在雌激素剥夺状态下,EGF可以通过激活ERK信号通路,刺激异位子宫内膜细胞的增殖,但需依赖ER的存在;异位子宫内膜病灶中EGF、EGFR、pERK1/2蛋白表达水平的抑制随雌激素剥夺时间的延长而逐渐减弱.%Objective To study the role of epidermal growth factor (EGF),epidermal growth factor receptor(EGFR),extracellular signal-regulated kinase 1/2 (p-ERK1/2) in the pathogenesis of endometriosis under estrogen deprivation conditions.Methods The estrogen was quickly-stripped in medium and the female nude mice were castrated by bilateral oophorectomy to build estrogen deprivation in vitro and in vivo experimental models,respectively.(1) In vitro experiments:according to different treatments the estrogen deprived ectopic endometrial cells were classified into 4 groups:①EGF group:the ectopic

  6. An Endosomal NAADP-Sensitive Two-Pore Ca2+ Channel Regulates ER-Endosome Membrane Contact Sites to Control Growth Factor Signaling

    Directory of Open Access Journals (Sweden)

    Bethan S. Kilpatrick

    2017-02-01

    Full Text Available Membrane contact sites are regions of close apposition between organelles that facilitate information transfer. Here, we reveal an essential role for Ca2+ derived from the endo-lysosomal system in maintaining contact between endosomes and the endoplasmic reticulum (ER. Antagonizing action of the Ca2+-mobilizing messenger NAADP, inhibiting its target endo-lysosomal ion channel, TPC1, and buffering local Ca2+ fluxes all clustered and enlarged late endosomes/lysosomes. We show that TPC1 localizes to ER-endosome contact sites and is required for their formation. Reducing NAADP-dependent contacts delayed EGF receptor de-phosphorylation consistent with close apposition of endocytosed receptors with the ER-localized phosphatase PTP1B. In accord, downstream MAP kinase activation and mobilization of ER Ca2+ stores by EGF were exaggerated upon NAADP blockade. Membrane contact sites between endosomes and the ER thus emerge as Ca2+-dependent hubs for signaling.

  7. Nerve growth factor signaling in prostate health and disease.

    Science.gov (United States)

    Arrighi, Nicola; Bodei, Serena; Zani, Danilo; Simeone, Claudio; Cunico, Sergio Cosciani; Missale, Cristina; Spano, Pierfranco; Sigala, Sandra

    2010-06-01

    The prostate is one of the most abundant sources of nerve growth factor (NGF) in different species, including humans. NGF and its receptors are implicated in the control of prostate cell proliferation and apoptosis and it can either support or suppress cell growth. The co-expression of both NGF receptors, p75(NGFR) and tropomyosin-related kinase A (trkA), represents a crucial condition for the antiproliferative effect of NGF; indeed, p75(NGFR) is progressively lost during prostate tumorigenesis and its disappearance represents a malignancy marker of prostate adenocarcinoma (PCa). Interestingly, a dysregulation of NGF signal transduction was found in a number of human tumors. This review summarizes the current knowledge on the role of NGF and its receptors in prostate and in PCa. Conclusions bring to the hypothesis that the NGF network could be a candidate for future pharmacological manipulation in the PCa therapy: in particular the re-expression of p75(NTR) and/or the negative modulation of trkA could represent a target to induce apoptosis and to reduce proliferation and invasiveness of PCa.

  8. Inhibition of Cdc42 is essential for Mig-6 suppression of cell migration induced by EGF.

    Science.gov (United States)

    Jiang, Xinni; Niu, MengMeng; Chen, Deshi; Chen, Jing; Cao, Yang; Li, Xiaorong; Ying, Haoqiang; Bergholz, Johann; Zhang, Yujun; Xiao, Zhi-Xiong

    2016-08-02

    The adaptor protein Mig-6 is a negative regulator of EGF signaling. It is shown that Mig-6 inhibits cell migration via direct interaction with the ErbB receptors, thereby inhibiting cross-phosphorylation or targeting the receptors for degradation. Mig-6 has also been shown to bind to and inhibit the Rho GTPase Cdc42 to suppress cytoskeletal rearrangement. However, the molecular mechanism(s) by which Mig-6 inhibits cell migration via Cdc42 is still not entirely clear. Here, we show that Mig-6 binding to Cdc42 is necessary and sufficient to inhibit EGF-induced filopodia formation and migration. This binding, mediated by four specific residues (I11, R12, M26, R30) in the Mig-6 CRIB domain, is essential for Mig-6 function. In addition, ectopic expression of Cdc42 reverses Mig-6 inhibition of cell migration. Mig-6 CRIB domain, alone, is sufficient to inhibit cell migration. Conversely, Mig-6 binding to EGFR is dispensable for Mig-6-mediated inhibition of cell migration. Moreover, we found that decreased Mig-6 expression correlates with cancer progression in breast and prostate cancers. Together, our results demonstrate that Mig-6 inhibition of Cdc42 signaling is critical in Mig-6 function to suppress cell migration and that dysregulation of this pathway may play a critical role in cancer development.

  9. Expression of renal distal tubule transporters TRPM6 and NCC in a rat model of cyclosporine nephrotoxicity and effect of EGF treatment.

    Science.gov (United States)

    Ledeganck, Kristien J; Boulet, Gaëlle A; Horvath, Caroline A; Vinckx, Marleen; Bogers, Johannes J; Van Den Bossche, Rita; Verpooten, Gert A; De Winter, Benedicte Y

    2011-09-01

    Renal magnesium (Mg(2+)) and sodium (Na(+)) loss are well-known side effects of cyclosporine (CsA) treatment in humans, but the underlying mechanisms still remain unclear. Recently, it was shown that epidermal growth factor (EGF) stimulates Mg(2+) reabsorption in the distal convoluted tubule (DCT) via TRPM6 (Thébault S, Alexander RT, Tiel Groenestege WM, Hoenderop JG, Bindels RJ. J Am Soc Nephrol 20: 78-85, 2009). In the DCT, the final adjustment of renal sodium excretion is regulated by the thiazide-sensitive Na(+)-Cl(-) cotransporter (NCC), which is activated by the renin-angiotensin-aldosterone system (RAAS). The aim of this study was to gain more insight into the molecular mechanisms of CsA-induced hypomagnesemia and hyponatremia. Therefore, the renal expression of TRPM6, TRPM7, EGF, EGF receptor, claudin-16, claudin-19, and the NCC, and the effect of the RAAS on NCC expression, were analyzed in vivo in a rat model of CsA nephrotoxicity. Also, the effect of EGF administration on these parameters was studied. CsA significantly decreased the renal expression of TRPM6, TRPM7, NCC, and EGF, but not that of claudin-16 and claudin-19. Serum aldosterone was significantly lower in CsA-treated rats. In control rats treated with EGF, an increased renal expression of TRPM6 together with a decreased fractional excretion of Mg(2+) (FE Mg(2+)) was demonstrated. EGF did not show this beneficial effect on TRPM6 and FE Mg(2+) in CsA-treated rats. These data suggest that CsA treatment affects Mg(2+) homeostasis via the downregulation of TRPM6 in the DCT. Furthermore, CsA downregulates the NCC in the DCT, associated with an inactivation of the RAAS, resulting in renal sodium loss.

  10. Modeling invasive breast cancer: growth factors propel progression of HER2-positive premalignant lesions.

    Science.gov (United States)

    Pradeep, C-R; Zeisel, A; Köstler, W J; Lauriola, M; Jacob-Hirsch, J; Haibe-Kains, B; Amariglio, N; Ben-Chetrit, N; Emde, A; Solomonov, I; Neufeld, G; Piccart, M; Sagi, I; Sotiriou, C; Rechavi, G; Domany, E; Desmedt, C; Yarden, Y

    2012-08-01

    The HER2/neu oncogene encodes a receptor-like tyrosine kinase whose overexpression in breast cancer predicts poor prognosis and resistance to conventional therapies. However, the mechanisms underlying aggressiveness of HER2 (human epidermal growth factor receptor 2)-overexpressing tumors remain incompletely understood. Because it assists epidermal growth factor (EGF) and neuregulin receptors, we overexpressed HER2 in MCF10A mammary cells and applied growth factors. HER2-overexpressing cells grown in extracellular matrix formed filled spheroids, which protruded outgrowths upon growth factor stimulation. Our transcriptome analyses imply a two-hit model for invasive growth: HER2-induced proliferation and evasion from anoikis generate filled structures, which are morphologically and transcriptionally analogous to preinvasive patients' lesions. In the second hit, EGF escalates signaling and transcriptional responses leading to invasive growth. Consistent with clinical relevance, a gene expression signature based on the HER2/EGF-activated transcriptional program can predict poorer prognosis of a subgroup of HER2-overexpressing patients. In conclusion, the integration of a three-dimensional cellular model and clinical data attributes progression of HER2-overexpressing lesions to EGF-like growth factors acting in the context of the tumor's microenvironment.

  11. TCDD AND EGF AFFECT MAPK PATHWAY ACTIVATION IN MURINE EMBRYONIC PALATE

    Science.gov (United States)

    Palatal fusion occurs on GD 14-15 in the mouse, accompanied by a decrease in EGF receptor (EGFR) at the medial edge of the palatal shelves. 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) induces cleft palate and maintains EGF and EGF receptor (EGFR) expression levels in the medial ed...

  12. Characterization of ubiquitination dependent dynamics in growth factor receptor signaling by quantitative proteomics

    DEFF Research Database (Denmark)

    Akimov, Vyacheslav; Rigbolt, Kristoffer T G; Nielsen, Mogens M;

    2011-01-01

    ) for selectively decoding ubiquitination-driven processes involved in the regulation of cellular signaling networks. We applied this approach to characterize the temporal dynamics of ubiquitination events accompanying epidermal growth factor receptor (EGFR) signal transduction. We used recombinant UBDs derived...

  13. Autotaxin-mediated lipid signaling intersects with LIF and BMP signaling to promote the naive pluripotency transcription factor program

    Science.gov (United States)

    Kime, Cody; Sakaki-Yumoto, Masayo; Goodrich, Leeanne; Hayashi, Yohei; Sami, Salma; Derynck, Rik; Asahi, Michio; Panning, Barbara; Yamanaka, Shinya; Tomoda, Kiichiro

    2016-01-01

    Developmental signaling molecules are used for cell fate determination, and understanding how their combinatorial effects produce the variety of cell types in multicellular organisms is a key problem in biology. Here, we demonstrate that the combination of leukemia inhibitory factor (LIF), bone morphogenetic protein 4 (BMP4), lysophosphatidic acid (LPA), and ascorbic acid (AA) efficiently converts mouse primed pluripotent stem cells (PSCs) into naive PSCs. Signaling by the lipid LPA through its receptor LPAR1 and downstream effector Rho-associated protein kinase (ROCK) cooperated with LIF signaling to promote this conversion. BMP4, which also stimulates conversion to naive pluripotency, bypassed the need for exogenous LPA by increasing the activity of the extracellular LPA-producing enzyme autotaxin (ATX). We found that LIF and LPA-LPAR1 signaling affect the abundance of signal transducer and activator of transcription 3 (STAT3), which induces a previously unappreciated Kruppel-like factor (KLF)2-KLF4-PR domain 14 (PRDM14) transcription factor circuit key to establish naive pluripotency. AA also affects this transcription factor circuit by controlling PRDM14 expression. Thus, our study reveals that ATX-mediated autocrine lipid signaling promotes naive pluripotency by intersecting with LIF and BMP4 signaling. PMID:27738243

  14. The molecular basis of the cooperation between EGF, FGF and eCB receptors in the regulation of neural stem cell function.

    Science.gov (United States)

    Sütterlin, Philipp; Williams, Emma J; Chambers, David; Saraf, Kathryn; von Schack, David; Reisenberg, Melina; Doherty, Patrick; Williams, Gareth

    2013-01-01

    Adult neurogenesis relies on EGF and FGF receptor (EGFR/FGFR) function and endocannabinoid (eCB) signalling. Here we have used a neural stem cell (NSC) line to determine how these systems cooperate to regulate neurogenesis. The results show the EGFR to be solely responsible for maintaining PI3K activation explaining its dominant role in promoting NSC survival. The EGFR and FGFR synergistically regulate the ERK/MAPK pathway, and this explains the requirement for both for optimal cell proliferation. The eCB receptors did not contribute to activation of the PI3K or ERK/MAPK pathways, highlighting the importance of another major proliferation pathway. The EGFR plays the dominant role in maintaining the transcriptome, with significant changes in the expression of over 3500 transcripts seen within hours of inhibition or activation of this receptor. The FGFR has a more modest effect on transcription with evidence for nodal integration with EGFR signalling at the level of the ERK/MAPK pathway. A common set of transcripts are regulated by the CB1 and CB2 receptors, with cooperation between these receptors and the EGFR apparent in the regulation of a pool of transcripts, most likely representing signal integration downstream from an as yet to be identified node. Finally, a first level molecular analysis of the transcriptional response shows regulation of a number of key growth factors, growth factor receptors and GPCRs to be under the control of the EGFR. Copyright © 2012 Elsevier Inc. All rights reserved.

  15. A mouse model of otitis media identifies HB-EGF as a mediator of inflammation-induced mucosal proliferation.

    Directory of Open Access Journals (Sweden)

    Keigo Suzukawa

    Full Text Available Otitis media is one of the most common pediatric infections. While it is usually treated without difficulty, up to 20% of children may progress to long-term complications that include hearing loss, impaired speech and language development, academic underachievement, and irreversible disease. Hyperplasia of middle ear mucosa contributes to the sequelae of acute otitis media and is of important clinical significance. Understanding the role of growth factors in the mediation of mucosal hyperplasia could lead to the development of new therapeutic interventions for this disease and its sequelae.From a whole genome gene array analysis of mRNA expression during acute otitis media, we identified growth factors with expression kinetics temporally related to hyperplasia. We then tested these factors for their ability to stimulate mucosal epithelial growth in vitro, and determined protein levels and histological distribution in vivo for active factors.From the gene array, we identified seven candidate growth factors with upregulation of mRNA expression kinetics related to mucosal hyperplasia. Of the seven, only HB-EGF (heparin-binding-epidermal growth factor induced significant mucosal epithelial hyperplasia in vitro. Subsequent quantification of HB-EGF protein expression in vivo via Western blot analysis confirmed that the protein is highly expressed from 6 hours to 24 hours after bacterial inoculation, while immunohistochemistry revealed production by middle ear epithelial cells and infiltrating lymphocytes.Our data suggest an active role for HB-EGF in the hyperplasia of the middle ear mucosal epithelium during otitis media. These results imply that therapies targeting HB-EGF could ameliorate mucosal growth during otitis media, and thereby reduce detrimental sequelae of this childhood disease.

  16. Mechanisms for growth factor-induced pituitary tumor transforming gene-1 expression in pituitary folliculostellate TtT/GF cells.

    Science.gov (United States)

    Vlotides, G; Cruz-Soto, M; Rubinek, T; Eigler, T; Auernhammer, C J; Melmed, S

    2006-12-01

    PTTG1, a securin protein, also behaves as a transforming gene and is overexpressed in pituitary tumors. Because pituitary folliculostellate (FS) cells regulate pituitary tumor growth factors by paracrine mechanisms, epidermal growth factor (EGF) receptor (EGFR)-mediated PTTG1 expression and cell proliferation was tested in pituitary FS TtT/GF cells. EGFR ligands caused up to 3-fold induction of Pttg1 mRNA expression, enhanced proliferating cell nuclear antigen, and increased entry of G0/1-arrested cells into S-phase. PTTG binding factor mRNA expression was not altered. EGF-induced Pttg1 expression and cell proliferation was abolished by preincubation of TtT/GF cells with EGFR inhibitors AG1478 and gefitinib. Phosphatidylinositol 3 kinase, protein kinase C, and MAPK, but not c-Jun N-terminal kinase and Janus activating kinase signaling regulated EGF-induced Pttg1, as well as proliferating cell nuclear antigen mRNA expression and entry into S-phase. EGF-induced EGFR and ERK1/2 phosphorylation was followed by rapid MAPK kinase/ERK kinase-dependent activation of Elk-1 and c-Fos. EGF-induced Pttg1 expression peaked at the S-G2 transition and declined thereafter. Pttg1 cell cycle dependency was confirmed by suppression of EGF-induced Pttg1 mRNA by blockade of cells in early S-phase. The results show that PTTG1 and its binding protein PTTG binding factor are expressed in pituitary FS TtT/GF cells. EGFR ligands induce PTTG1 and regulate S-phase, mediated by phosphatidylinositol 3 kinase, protein kinase C, and MAPK pathways. PTTG1 is therefore a target for EGFR-mediated paracrine regulation of pituitary cell growth.

  17. From tyrosine to melanin: Signaling pathways and factors regulating melanogenesis

    Directory of Open Access Journals (Sweden)

    Zuzanna Rzepka

    2016-06-01

    Full Text Available Melanins are natural pigments of skin, hair and eyes and can be classified into two main types: brown to black eumelanin and yellow to reddish-brown pheomelanin. Biosynthesis of melanins takes place in melanosomes, which are specialized cytoplasmic organelles of melanocytes - dendritic cells located in the basal layer of the epidermis, uveal tract of the eye, hair follicles, as well as in the inner ear, central nervous system and heart. Melanogenesis is a multistep process and begins with the conversion of amino acid L-tyrosine to DOPAquinone. The addition of cysteine or glutathione to DOPAquinone leads to the intermediates formation, followed by subsequent transformations and polymerization to the final product, pheomelanin. In the absence of thiol compounds DOPAquinone undergoes an intramolecular cyclization and oxidation to form DOPAchrome, which is then converted to 5,6-dihydroksyindole (DHI or 5,6-dihydroxyindole-2-carboxylic acid (DHICA. Eumelanin is formed by polymerization of DHI and DHICA and their quinones. Regulation of melanogenesis is achieved by physical and biochemical factors. The article presents the intracellular signaling pathways: cAMP/PKA/CREB/MITF cascade, MAP kinases cascade, PLC/DAG/PKCβ cascade and NO/cGMP/PKG cascade, which are involved in the regulation of expression and activity of the melanogenesis-related proteins by ultraviolet radiation and endogenous agents (cytokines, hormones. Activity of the key melanogenic enzyme, tyrosinase, is also affected by pH and temperature. Many pharmacologically active substances are able to inhibit or stimulate melanin biosynthesis, as evidenced by in vitro studies on cultured pigment cells.

  18. Enhanced Antitumor Activity of EGFP-EGF1-Conjugated Nanoparticles by a Multitargeting Strategy.

    Science.gov (United States)

    Zhang, Bo; Jiang, Ting; Ling, Li; Cao, Zhonglian; Zhao, Jingjing; Tuo, Yanyan; She, Xiaojian; Shen, Shun; Jiang, Xinguo; Hu, Yu; Pang, Zhiqing

    2016-04-13

    Tumor stromal cells have been increasingly recognized to interact with tumor parenchyma cells and promote tumor growth. Therefore, we speculated that therapeutics delivery to both parenchyma cells and stromal cells simultaneously might treat a tumor more effectively. Tissue factor (TF) was shown to be extensively located in a tumor and was abundantly sited in both tumor parenchyma cells and stromal cells including neo-vascular cells, tumor-associated fibroblasts, and tumor-associated macrophages, indicating it might function as a favorable target for drug delivery to multiple cell types simultaneously. EGFP-EGF1 is a fusion protein derived from factor VII, the natural ligand of TF. It retains the specific TF binding capability but does not cause coagulation. In the present study, a nanoparticle modified with EGFP-EGF1 (ENP) was constructed as a multitargeting drug delivery system. The protein binding experiment showed EGFP-EGF1 could bind well to A549 tumor cells and other stromal cells including neo-vascular cells, tumor-associated fibroblasts, and tumor-associated macrophages. Compared with unmodified nanoparticles (NP), ENP uptake by A549 cells and those stromal cells was significantly enhanced but inhibited by excessive free EGFP-EGF1. In addition, ENP induced more A549 tumor cell apoptosis than Taxol and NP when paclitaxel (PTX) was loaded. In vivo, ENP accumulated more specially in TF-overexpressed A549 tumors by in vivo imaging, mainly regions unoccupied by factor VII and targeted tumor parenchyma cells as well as different types of stromal cells by immunofluorescence staining. Treatment with PTX-loaded ENP (ENP-PTX) significantly reduced the A549 tumor growth in nude mice while NP-PTX- and Taxol-treated mice had lower response to the therapy. Furthermore, H&E and TUNEL staining revealed that ENP-PTX induced more severe tumor necrosis and more extensive cell apoptosis. Altogether, the present study demonstrated that ENP could target multiple key cell types

  19. Targeting signaling factors for degradation, an emerging mechanism for TRAF functions

    OpenAIRE

    Yang, Xiao-Dong; Sun, Shao-Cong

    2015-01-01

    Tumor necrosis factor receptor (TNFR)-associated factors (TRAFs) form a family of proteins that are best known as signaling adapters of TNFRs. However, emerging evidence suggests that TRAF proteins, particularly TRAF2 and TRAF3, also regulate signal transduction by controlling the fate of intracellular signaling factors. A well-recognized function of TRAF2 and TRAF3 in this aspect is to mediate ubiquitin-dependent degradation of NF-κB-inducing kinase (NIK), an action required for the control ...

  20. Taiwan cobra cardiotoxin III suppresses EGF/EGFR-mediated epithelial-to-mesenchymal transition and invasion of human breast cancer MDA-MB-231 cells.

    Science.gov (United States)

    Tsai, Pei-Chien; Fu, Yaw-Syan; Chang, Long-Sen; Lin, Shinne-Ren

    2016-03-01

    Breast cancer is a highly malignant carcinoma and most deaths of breast cancer are caused by metastasis. The epithelial-to-mesenchymal transition (EMT) has emerged as a pivotal event in the development of the invasive and metastatic potentials of cancer progression. Epidermal growth factor (EGF) and its receptor, EGFR, play roles in cancer metastasis. CTX III, a basic polypeptide isolated from Naja naja atra venom, has been shown to exhibit anticancer activity; however, the effect of CTX III on the EMT of cancer cells remains elusive. CTX III treatment resulted in morphological changes from elongated and spindle shape to rounded and epithelial-like shape, induced upregulation of E-cadherin and concurrent downregulation of N-cadherin and Vimentin protein levels, corresponding to observed decreases in cell migration and invasion. CTX III treatment also decreased the expression of Snail and Twist in EGF-induced MDA-MB-231 cells. Concurrently, CTX III efficiently inhibited the EGFR phosphorylation and downstream activation of phosphatidylinositol 3-kinase (PI3K)/Akt and ERK1/2. The EGFR specific inhibitor AG1478 significantly suppressed ERK1/2 and Akt phosphorylation, cell migration and invasion, as well as the expressional changes associated with EMT markers in EGF-induced MDA-MB-231 cells. CTX III inhibitory effect on EGF-evoked invasion of MDA-MB-231 cells is mediated through suppressing EGF/EGFR activation and EMT process.

  1. The safety and efficacy of EGF-based cream for the prevention of radiotherapy-induced skin injury: results from a multicenter observational study

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Hyun Cheol [Dept.of Radiation Oncology, Seoul National University College of Medicine, Seoul (Korea, Republic of); Ahn, Seung Do [Dept.of Radiation Oncology, Asan Medical Center, Seoul (Korea, Republic of); Choi, Doo Ho [Dept.of Radiation Oncology, Samsung Medical Center, Seoul (Korea, Republic of); Kang, Min Kyu [Dept.of Radiation Oncology, eungnam University College of Medicine, Daegu (Korea, Republic of); Wu, Hong Gyun [Dept.of Radiation Oncology, Chonnam National University Hwasun Hospital, Huasun (Korea, Republic of)

    2014-09-15

    This study was designed to evaluate the efficacy and safety of topically applied recombinant human epidermal growth factor (rhEGF) for the prevention of radiation-induced dermatitis in cancer patients. From December 2010 to April 2012, a total of 1,172 cancer patients who received radiotherapy (RT) of more than 50 Gy were prospectively enrolled and treated with EGF-based cream. An acute skin reaction classified according to the Radiation Therapy Oncology Group 6-point rating scale was the primary end point and we also assessed the occurrence of edema, dry skin, or pruritus. The percentage of radiation dermatitis with maximum grade 0 and grade 1 was 19% and 58% at the time of 50 Gy, and it became 29% and 47% after completion of planned RT. This increment was observed only in breast cancer patients (from 18%/62% to 32%/49%). Adverse events related to the EGF-based cream developed in 49 patients (4%) with mild erythema the most common. Skin toxicity grade >2 was observed in 5% of the patients. Edema, dry skin, and pruritus grade > or =3 developed in 9%, 9%, and 1% of the patients, respectively. Prophylactic use of an EGF-based cream is effective in preventing radiation dermatitis with tolerable toxicity. Further studies comparing EGF cream with other topical agents may be necessary.

  2. Signal and Noise scaling factors in digital holography

    CERN Document Server

    Lesaffre, Max; Atlan, Michael; Gross, Michel

    2013-01-01

    An experimental study on how reconstructed image signal and noise scale with acquisition and reconstruction parameters is proposed. Monte-carlo simulation is performed to emphasize that the measured noise is shot-noise.

  3. Control of MicroRNA-21 expression in colorectal cancer cells by oncogenic epidermal growth factor/Ras signaling and Ets transcription factors.

    Science.gov (United States)

    Kern, Hanna B; Niemeyer, Brian F; Parrish, Janet K; Kerr, Carol A; Yaghi, Nasser K; Prescott, Jason D; Gutierrez-Hartmann, Arthur; Jedlicka, Paul

    2012-08-01

    MicroRNAs (miRs) are important regulators of gene expression in normal physiology and disease, and are widely misexpressed in cancer. A number of studies have identified miR-21 as an important promoter of oncogenesis. However, as is true of most miRs, the mechanisms behind the aberrant expression of miR-21 in cancer are poorly understood. Herein, we examine the regulation of miR-21 expression in colorectal cancer (CRC) cells by the oncogenic epidermal growth factor (EGF)/Ras pathway and by Ets transcription factors, modulators of epithelial oncogenesis that are frequently misexpressed in CRC. We show that EGF/Ras efficiently induces the miR-21 primary transcript, but this does not rapidly and simply translate into higher mature miR-21 levels. Rather, induction of mature miR-21 by constitutive activation of this pathway is slow, is associated with only minimal activation of mitogen-activated protein kinase, and may involve stimulation of post-transcriptional processing by mechanisms other than Dicer stabilization. We further identify Ets transcription factors as modifiers of miR-21 expression in CRC. The effects of Ets factors on miR-21 expression are cell context-dependent, and appear to involve both direct and indirect mechanisms. The Ets factor Pea3 emerges from our studies as a consistent repressor of miR-21 transcription. Overall, our studies identify a complex relationship between oncogenic pathways and steady-state miR-21 levels in CRC, and highlight the need for greater understanding of the control of miR expression in cancer and other disease states.

  4. Caenorhabditis elegans inositol 5-phosphatase homolog negatively regulates inositol 1,4,5-triphosphate signaling in ovulation.

    Science.gov (United States)

    Bui, Yen Kim; Sternberg, Paul W

    2002-05-01

    Ovulation in Caenorhabditis elegans requires inositol 1,4,5-triphosphate (IP(3)) signaling activated by the epidermal growth factor (EGF)-receptor homolog LET-23. We generated a deletion mutant of a type I 5-phosphatase, ipp-5, and found a novel ovulation phenotype whereby the spermatheca hyperextends to engulf two oocytes per ovulation cycle. The temporal and spatial expression of IPP-5 is consistent with its proposed inhibition of IP(3) signaling in the adult spermatheca. ipp-5 acts downstream of let-23, and interacts with let-23-mediated IP(3) signaling pathway genes. We infer that IPP-5 negatively regulates IP(3) signaling to ensure proper spermathecal contraction.

  5. Signal transduction by M3 muscarinic acetylcholine receptor in prostate cancer

    Science.gov (United States)

    GUO, LIQIANG; LIU, YUQIANG; DING, ZHIBO; SUN, WENDONG; YUAN, MINGZHEN

    2016-01-01

    The present study aimed to investigate the potential mechanisms used during signal transduction by M3 muscarinic acetylcholine receptor (CHRM3) in prostate cancer. The microarray datasets of GSE3325, including 5 clinically localized primary prostate cancers and 4 benign prostate tissues, were downloaded from the Gene Expression Omnibus database. The differentially-expressed genes (DEGs) in primary prostate cancer tissues compared with benign controls were screened using the Limma package. Gene Ontology and pathway enrichment analyses were performed using the Database for Annotation Visualization and Integrated Discovery. Next, a protein-protein interaction (PPI) network was constructed. Additionally, microRNAs (miRNAs) associated with DEGs were predicted and miRNA-target DEG analysis was performed using a Web-based Gene Set Analysis Toolkit. Finally, the PPI network and the miRNA-target DEG network were integrated using Cytoscape. In total, 224 DEGs were screened in the prostate cancer tissues, including 113 upregulated and 111 downregulated genes. CHRM3 and epidermal growth factor (EGF) were enriched in the regulation of the actin cytoskeleton. EGF and v-myc avian myelocytomatosis viral oncogene homolog (Myc) were enriched in the mitogen-activated protein kinase (MAPK) signaling pathway. EGF with the highest degree of connectivity was the hub node in the PPI network, and miR-34b could interact with Myc directly in the miRNA-target DEG network. EGF and Myc may exhibit significant roles in the progression of prostate cancer via regulation of the actin cytoskeleton and the MAPK signaling pathway. CHRM3 may activate these two pathways in prostate cancer progression. Thus, these two key factors and pathways may be crucial mechanisms during signal transduction by CHRM3 in prostate cancer. PMID:26870222

  6. Combined Influence of EGF+61G>A and TGFB+869T>C Functional Polymorphisms in Renal Cell Carcinoma Progression and Overall Survival: The Link to Plasma Circulating MiR-7 and MiR-221/222 Expression

    Science.gov (United States)

    Teixeira, Ana L.; Dias, Francisca; Ferreira, Marta; Gomes, Mónica; Santos, Juliana I.; Lobo, Francisco; Maurício, Joaquina; Machado, José Carlos; Medeiros, Rui

    2015-01-01

    The epidermal growth factor (EGF) is responsible for the activation of intracellular signal transducers that act on cell-cycle progression, cell motility, angiogenesis and inhibition of apoptosis. However, cells can block these effects activating opposite signaling pathways, such as the transforming growth factor beta 1 (TGFβ1) pathway. Thus changes in expression levels of EGF and TGFB1 in renal cells might modulate the renal cell carcinoma (RCC) development, in consequence of changes in regulatory elements of signaling networks such as the microRNAs (miRNAs). Our purpose was to investigate the synergic role of EGF+61G>A and TGFB1+869T>C polymorphisms in RCC development. Genetic polymorphisms were studied by allelic discrimination using real-time PCR in 133 RCC patients vs. 443 healthy individuals. The circulating EGF/EGFR-MAPK-related miR-7, miR-221 and miR-222 expression was analyzed by a quantitative real-time PCR in plasma from 22 RCC patients vs. 27 healthy individuals. The intermediate/high genetic proliferation profile patients carriers present a significantly reduced time-to-progression and a higher risk of an early relapse compared with the low genetic proliferation profile carriers (HR = 8.8, P = 0.038) with impact in a lower overall survival (Log rank test, P = 0.047). The RCC patients presented higher circulating expression levels of miR-7 than healthy individuals (6.1-fold increase, P<0.001). Moreover, the intermediate/high genetic proliferation profile carriers present an increase in expression levels of miR-7, miR-221 and miR-222 during the RCC development and this increase is not observed in low genetic proliferation profile (P<0.001, P = 0.004, P<0.001, respectively). The stimulus to angiogenesis, cell-cycle progression and tumoral cells invasion, through activation of EGFR/MAPK signaling pathway in intermediate/high proliferation profile carriers is associated with an early disease progression, resulting in a poor overall survival. We also

  7. Non-linear dimensionality reduction of signaling networks

    Directory of Open Access Journals (Sweden)

    Ivakhno Sergii

    2007-06-01

    Full Text Available Abstract Background Systems wide modeling and analysis of signaling networks is essential for understanding complex cellular behaviors, such as the biphasic responses to different combinations of cytokines and growth factors. For example, tumor necrosis factor (TNF can act as a proapoptotic or prosurvival factor depending on its concentration, the current state of signaling network and the presence of other cytokines. To understand combinatorial regulation in such systems, new computational approaches are required that can take into account non-linear interactions in signaling networks and provide tools for clustering, visualization and predictive modeling. Results Here we extended and applied an unsupervised non-linear dimensionality reduction approach, Isomap, to find clusters of similar treatment conditions in two cell signaling networks: (I apoptosis signaling network in human epithelial cancer cells treated with different combinations of TNF, epidermal growth factor (EGF and insulin and (II combination of signal transduction pathways stimulated by 21 different ligands based on AfCS double ligand screen data. For the analysis of the apoptosis signaling network we used the Cytokine compendium dataset where activity and concentration of 19 intracellular signaling molecules were measured to characterise apoptotic response to TNF, EGF and insulin. By projecting the original 19-dimensional space of intracellular signals into a low-dimensional space, Isomap was able to reconstruct clusters corresponding to different cytokine treatments that were identified with graph-based clustering. In comparison, Principal Component Analysis (PCA and Partial Least Squares – Discriminant analysis (PLS-DA were unable to find biologically meaningful clusters. We also showed that by using Isomap components for supervised classification with k-nearest neighbor (k-NN and quadratic discriminant analysis (QDA, apoptosis intensity can be predicted for different

  8. Bradykinin-mediated cell proliferation depends on transactivation of EGF receptor in corneal fibroblasts.

    Science.gov (United States)

    Cheng, Ching-Yi; Tseng, Hui-Ching; Yang, Chuen-Mao

    2012-04-01

    In previous studies, bradykinin (BK) has been shown to induce cell proliferation through BK B2 receptor (B2R) via p42/p44 MAPK in Statens Seruminstitut Rabbit Corneal Cells (SIRCs). In addition to this pathway, EGFR transactivation pathway has been implicated in linking a variety of G-protein coupled receptors to MAPK cascades. Here, we further investigate whether these transactivation mechanisms participating in BK-induced cell proliferation in SIRCs. Using an immunofluorescence staining and RT-PCR, we initially characterize that SIRCs were corneal fibroblasts and predominantly expressed B2R by BK. Inhibition of p42/p44 MAPK by the inhibitors of Src, EGFR, and Akt or transfection with respective siRNAs prevents BK-induced DNA synthesis in SIRCs. The mechanisms underlying these responses were mediated through phosphorylation of Src and EGFR via the formation of Src/EGFR complex which was attenuated by PP1 and AG1478. Moreover, BK-induced p42/p44 MAPK and Akt activation was mediated through EGFR transactivation, which was diminished by the inhibitors of MMP-2/9 and heparin-binding EGF-like factor (HB-EGF). Finally, increased nuclear translocation of Akt and p42/p44 MAPK turns on early gene expression leading to cell proliferation. These results suggest that BK-induced cell proliferation is mediated through c-Src-dependent transactivation of EGFR via MMP2/9-dependent pro-HB-EGF shedding linking to activation of Akt and p42/p44 MAPK in corneal fibroblasts. Copyright © 2011 Wiley Periodicals, Inc.

  9. Novel antineoplastic isochalcones inhibit the expression of cyclooxygenase 1,2 and EGF in human prostate cancer cell line LNCaP.

    Science.gov (United States)

    Johnson, K P; Rowe, G C; Jackson, B A; D'Agustino, J L; Campbell, P E; Guillory, B O; Williams, M V; Matthews, Q L; McKay, J; Charles, G M; Verret, C R; Deleon, M; Johnson, D E; Cooke, D B

    2001-09-01

    Experiments were conducted to determine the effects of novel anti-neoplastic isochalcones (DJ compounds), on cyclooxyegenase 1 and 2 (COX-1 and COX-2) enzyme expression in androgen receptor dependent human prostate cancer cell line LNCaP. Results from Western blot analysis and cell flow cytometry showed that DJ52 and DJ53 decreased the steady state levels of COX-1 and COX-2 protein levels in a dose dependent manner. In addition, DJ52 and DJ53 decreased the levels of epidermal growth factor (EGF) in LNCaP cells. In this study, we report that novel isochalcones decreased COX-1, COX-2 and EGF levels as well as LNCaP cellular growth in a dose responsive manner. Our findings indicate that relative decreases in COX-1, COX-2 and EGF expressions might serve as indicators of tumor growth inhibition in prostate neoplasms.

  10. Functional cross-talk between angiotensin II and epidermal growth factor receptors in NIH3T3 fibroblasts.

    Science.gov (United States)

    De Paolis, Paola; Porcellini, Antonio; Savoia, Carmine; Lombardi, Alessia; Gigante, Bruna; Frati, Giacomo; Rubattu, Speranza; Musumeci, Beatrice; Volpe, Massimo

    2002-04-01

    The main angiotensin (Ang) II subtype receptors (AT1R and AT2R) are involved in cellular growth processes and exert functionally antagonistic effects. To characterize the mechanisms by which Ang II receptors influence growth, by investigating the interactions between Ang II subtype receptors and epidermal growth factor (EGF) receptors on mitogen-activated protein kinase (MAPK) pathway activation. The experiments were performed using a mouse fibroblast cell line, NIH3T3, by transient co-transfection with rat AT1R or AT2R expression vectors, or both. Extracellular-signal-regulated kinase (ERK)1/2 phosphorylation was analysed by western blot and the ERK activity was evaluated using PathDetect, an in-vivo signal transduction pathway trans-reporting system. Selective Ang II receptor antagonists (losartan for AT1R and PD123319 for AT2R) were used to investigate the contributions of each receptor to the response observed. Our data show that, in this cellular model, both Ang II receptors phosphorylate ERK1/2. However, in the cells expressing AT1R, the EGF-induced MAPK pathway was enhanced in the presence of Ang II in a synergistic fashion. In contrast, a reduction of EGF-induced MAPK activation was observed in the cells expressing AT2R. In cells expressing both Ang II subtype receptors, Ang II promoted an enhancement of EGF-induced MAPK activation. However, in the presence of the AT1R antagonist, losartan, the effect of EGF was reduced. These data indicate the existence of an opposite cross-talk of AT1R and AT2R with EGF receptors, and suggest a complex functional interaction between these pathways in the regulation of cellular growth processes.

  11. FGF-receptor substrate 2 functions as a molecular sensor integrating external regulatory signals into the FGF pathway

    Institute of Scientific and Technical Information of China (English)

    Wenchao Zhou; Xiujing Feng; Yingjie Wu; Johannes Benge; Zhe Zhang; Zhengjun Chen

    2009-01-01

    Fibroblast growth factor (FGF) receptor substrate 2α (FRS2α) is the main mediator of signaling in the FGF path-way. Recent studies have shown that n/itogen-activated protein kinase (MAPK) phosphorylates serine and threonine residues in FRS2, negatively affecting FGF-induced tyrosine phosphorylation (PY) of FRS2. Several kinds of stimuli can induce serine/threonine phosphorylation (PS/T) of FRS2, indicating that FRS2 may be useful for studying cross-talk between growth factor signaling pathways. Here, we report that FGF-induced PY of FRS2 can be attenuated by EGF co-stimulation in PC12cells; this inhibitory effect could be completely reversed by U0126, an inhibitor of MEK. We further identified the ERK1/2-binding motif in FRS2 and generated FRS2-3KL, a mutant lacking MAPK binding and PT upon FGF and/or EGF stimulation. Unlike wild-type (WT) FRS2, FGF-induced PY of FRS2-3KL could not be inhibited by EGF co-stimulation, and FRS2-3KL-expressing PC12 cells exhibited more differentiating potential than FRS2-WT-expressing cells in response to FGF treatment. These results suggest that PSfr of FRS2 mediated by the FRS2-MAPK negative regulatory loop may function as a molecular switch integrating negative regulatory signals from other pathways into FGFR-generated signal transduction.

  12. Specific epidermal growth factor receptor autophosphorylation sites promote mouse colon epithelial cell chemotaxis and restitution.

    Science.gov (United States)

    Yamaoka, Toshimitsu; Frey, Mark R; Dise, Rebecca S; Bernard, Jessica K; Polk, D Brent

    2011-08-01

    Upon ligand binding, epidermal growth factor (EGF) receptor (R) autophosphorylates on COOH-terminal tyrosines, generating docking sites for signaling partners that stimulate proliferation, restitution, and chemotaxis. Specificity for individual EGFR tyrosines in cellular responses has been hypothesized but not well documented. Here we tested the requirement for particular tyrosines, and associated downstream pathways, in mouse colon epithelial cell chemotactic migration. We compared these requirements to those for the phenotypically distinct restitution (wound healing) migration. Wild-type, Y992/1173F, Y1045F, Y1068F, and Y1086F EGFR constructs were expressed in EGFR(-/-) cells; EGF-induced chemotaxis or restitution were determined by Boyden chamber or modified scratch wound assay, respectively. Pharmacological inhibitors of p38, phospholipase C (PLC), Src, MEK, JNK/SAPK, phosphatidylinositol 3-kinase (PI 3-kinase), and protein kinase C (PKC) were used to block EGF-stimulated signaling. Pathway activation was determined by immunoblot analysis. Unlike wild-type EGFR, Y992/1173F and Y1086F EGFR did not stimulate colon epithelial cell chemotaxis toward EGF; Y1045F and Y1068F EGFR partially stimulated chemotaxis. Only wild-type EGFR promoted colonocyte restitution. Inhibition of p38, PLC, and Src, or Grb2 knockdown, blocked chemotaxis; JNK, PI 3-kinase, and PKC inhibitors or c-Cbl knockdown blocked restitution but not chemotaxis. All four EGFR mutants stimulated downstream signaling in response to EGF, but Y992/1173F EGFR was partially defective in PLCγ activation whereas both Y1068F and Y1086F EGFR failed to activate Src. We conclude that specific EGFR tyrosines play key roles in determining cellular responses to ligand. Chemotaxis and restitution, which have different migration phenotypes and physiological consequences, have overlapping but not identical EGFR signaling requirements.

  13. Effect of oral epidermal growth factor on mucosal healing in rats with duodenal ulcer

    Institute of Scientific and Technical Information of China (English)

    Jane CJ Chao; Kuo-Yu Liu; Sheng-Hsuan Chen; Chia-Lang Fang; Chih-Wei Tsao

    2003-01-01

    AIM: To investigate the effect of epidermal growth factor (EGF) on mucosal healing in rats with duodenal ulcer.METHODS: Male Sprague-Dawley rats were randomly divided into sham operation without EGF, sham operation with EGF, duodenal ulcer without EGF, or duodenal ulcer with EGF groups. Additionally, normal rats without operation served as the control group. Duodenal ulcer was induced in rats by 300 mL/L acetic acid. Rats with EGF were orally administered at a dose of 60 μg/kg/day in drinking water on the next day of operation (day 1). Healing of duodenal ulcer was detected by haematoxylin and eosin staining. Cell growth of damaged mucosa was determined by the contents of nucleic acids and proteins. The level of EGF in duodenal mucosa was measured by ELISA.RESULTS: The pathological results showed that duodenal ulcer rats with EGF improved mucosal healing compared with those without EGF after day 5. Duodenal ulcer rats with EGF significantly increased duodenal DNA content compared with those without EGF on day 15 (6.44±0.54mg/g VS 1.45±0.52 mg/g mucosa, P<0.05). Duodenal RNA and protein contents did not differ between duodenal ulcer rats with and without EGF during the experimental period.Sham operation and duodenal ulcer rats with EGF significantly increased duodenal mucosal EGF content compared with those without EGF on day 5 (76.0±13.7 ng/g VS 35.7±12.9ng/g mucosa in sham operation rats, and 68.3±10.9 ng/gVS 28.3±9.2 ng/g mucosa in duodenal ulcer rats, P<0.05).CONCLUSION: Oral EGF can promote mucosal healing of the rats with duodenal ulcer by stimulating mucosal proliferation accompanied by an increase in mucosal EGF content.

  14. NGF and HB-EGF: potential biomarkers that reflect the effects of fesoterodine in patients with overactive bladder syndrome.

    Science.gov (United States)

    Kim, Soo Rim; Moon, Yeo Jung; Kim, Sei Kwang; Bai, Sang Wook

    2015-01-01

    To determine whether levels of nerve growth factor (NGF) and heparin-binding epidermal growth factor-like growth factor (HB-EGF) can be used to objectively assess overactive bladder syndrome (OAB) treatment outcome and to evaluate the effects of fixed-dose fesoterodine on OAB symptoms. This study included 124 participants (62 patients with OAB and 62 controls) in Severance Hospital between 2010 and 2012. In patients with OAB, 4 mg fesoterodine was administered once daily. Repeated evaluations of putative biomarker levels, urine creatinine (Cr) levels, and questionnaire responses, including the Overactive Bladder Symptom Score (OABSS) and the Overactive Bladder Questionnaire (OAB q), were performed from baseline to 16 weeks. Urinary levels of NGF/Cr (OAB: 1.13±0.9 pg/mg; control: 0.5±0.29 pg/mg) and HB-EGF/Cr (OAB: 8.73±6.55 pg/mg; control: 4.45±2.93 pg/mg) were significantly higher in subjects with OAB than in controls (pfesoterodine treatment, urinary NGF/Cr levels (baseline: 1.13±0.08 pg/mg; 16 weeks: 0.60±0.4 pg/mg; p=0.02) and HB-EGF/Cr levels significantly decreased (baseline: 8.73±6.55 pg/mg; 16 weeks: 4.72±2.69 pg/mg; p=0.03, respectively). Both the OABSS and OAB q scores improved (pfesoterodine improved OAB symptoms. Future studies are needed to further examine the significance of urinary NGF and HB-EGF levels as therapeutic markers for OAB.

  15. Induction of epithelial-mesenchymal transition (EMT) in breast cancer cells is calcium signal dependent.

    Science.gov (United States)

    Davis, F M; Azimi, I; Faville, R A; Peters, A A; Jalink, K; Putney, J W; Goodhill, G J; Thompson, E W; Roberts-Thomson, S J; Monteith, G R

    2014-05-01

    Signals from the tumor microenvironment trigger cancer cells to adopt an invasive phenotype through epithelial-mesenchymal transition (EMT). Relatively little is known regarding key signal transduction pathways that serve as cytosolic bridges between cell surface receptors and nuclear transcription factors to induce EMT. A better understanding of these early EMT events may identify potential targets for the control of metastasis. One rapid intracellular signaling pathway that has not yet been explored during EMT induction is calcium. Here we show that stimuli used to induce EMT produce a transient increase in cytosolic calcium levels in human breast cancer cells. Attenuation of the calcium signal by intracellular calcium chelation significantly reduced epidermal growth factor (EGF)- and hypoxia-induced EMT. Intracellular calcium chelation also inhibited EGF-induced activation of signal transducer and activator of transcription 3 (STAT3), while preserving other signal transduction pathways such as Akt and extracellular signal-regulated kinase 1/2 (ERK1/2) phosphorylation. To identify calcium-permeable channels that may regulate EMT induction in breast cancer cells, we performed a targeted siRNA-based screen. We found that transient receptor potential-melastatin-like 7 (TRPM7) channel expression regulated EGF-induced STAT3 phosphorylation and expression of the EMT marker vimentin. Although intracellular calcium chelation almost completely blocked the induction of many EMT markers, including vimentin, Twist and N-cadherin, the effect of TRPM7 silencing was specific for vimentin protein expression and STAT3 phosphorylation. These results indicate that TRPM7 is a partial regulator of EMT in breast cancer cells, and that other calcium-permeable ion channels are also involved in calcium-dependent EMT induction. In summary, this work establishes an important role for the intracellular calcium signal in the induction of EMT in human breast cancer cells. Manipulation of

  16. Regulation of epidermal growth factor receptor signaling during oxidative stress

    NARCIS (Netherlands)

    Wit, Renate de

    2001-01-01

    This thesis described the effects of exposure of cells to oxidative stress,induced by H 2 O 2 ,on the functioning of proteins involved in signal transduction pathways.In addition, H 2 O 2 was chosen as oxidant in order to produce cellular screening assays to measure antioxidant efficacy in preventin

  17. Relationships between cobalamin, epidermal growth factor, and normal prions in the myelin maintenance of central nervous system.

    Science.gov (United States)

    Scalabrino, Giuseppe; Veber, Daniela; Tredici, Giovanni

    2014-10-01

    Cobalamin (Cbl), epidermal growth factor (EGF), and prions (PrPs) are key molecules for myelin maintenance in the central and peripheral nervous systems. Cbl and EGF increase normal prion (PrP(C)) synthesis and PrP(C) levels in rat spinal cord (SC) and elsewhere. Cbl deficiency increases PrP(C) levels in rat SC and cerebrospinal fluid (CSF), and decreases PrP(C)-mRNA levels in rat SC. The administration of anti-octapeptide repeat PrP(C) region antibodies (Abs) to Cbl-deficient (Cbl-D) rats prevents SC myelin lesions and a local increase in tumor necrosis factor (TNF)-α levels, whereas anti-TNF-α Abs prevent SC myelin lesions and the increase in SC and CSF PrP(C) levels. As it is known that both Cbl and EGF regulate SC PrP(C) synthesis independently, and that Cbl regulates SC EGF synthesis, EGF may play both Cbl-independent and Cbl-dependent roles. When Cbl-D rats undergo Cbl replacement therapy, SC PrP(C) levels are similar to those observed in Cbl-D rats. In rat frontal cortex (which is marginally affected by Cbl deficiency in histological terms), Cbl deficiency decreases PrP(C) levels and the increase induced by Cbl replacement leads to their normalization. Increased nerve PrP(C) levels are detected in the myelin lesions of the peripheral neuropathy of Cbl-D rats, and CSF PrP(C) levels are also increased in Cbl-D patients (but not in patients with Cbl-unrelated neurological diseases). Various common steps in the downstream signaling pathway of Cbl, EGF, and PrP(C) underlines the close relationship between the three molecules in keeping myelin normal.

  18. Fetal antigen 1, an EGF multidomain protein in the sex hormone-producing cells of the gonads and the microenvironment of germ cells

    DEFF Research Database (Denmark)

    Jensen, Charlotte Harken; Erb, K; Westergaard, L G

    1999-01-01

    Fetal antigen 1 (FA1), an epidermal growth factor (EGF) multidomain glycoprotein, was investigated in the human reproductive system. Immunohistochemical analysis of the male reproductive system revealed staining for FA1 in the Leydig cells only. Concentrations of FA1 in seminal plasma and serum w...

  19. The correlation between serum epidermal growth factor/testicular epidermal growth factor receptor and spermatogenesis in rat

    Institute of Scientific and Technical Information of China (English)

    Peng Yi-feng; Bao Shi-hua; Xu Dong-liang; Zong Wan; Fang Xiang; Sheng Shi-le; Lu Ling-ming; Xu Guo-xiang; LU Ren-kang

    2004-01-01

    Objective: To investigate the correlation between epidermal growth factor (EGF)/testicular epidermal growth factor receptor (EGF-R) and spermatogenesis in rat.Methods: Forty mature male Spraque-Dauley (SD) rats were randomly assigned to four groups, ten rats in each: sham operation group (SOG), sialoadenectomy group (SG), sialoadeand blood and testes were obtained on the 48th day after the operation. Serum EGF concentrations were determined by radioimmunoassay (RIA), expression of EGF-R in testes was examined by the immunohistochemical method, and the spermatogenesis was pathologically checked.Results:Serum EGF levels in SG-EGFIand SG decreased significantly when compared with those of SOG (P<0.05 and P< 0.01, respectively). The testicular function of spermatogenesis showed a moderate to severe impairment in SG. The expression of EGF-R in Leydig cells decreased in SG (P< 0. 05). The two dosage groups of EGF replacement had different effects.There were no significant differences of EGF-R expression in testicular germ cells, Sertoli cells and Leydig cells in SOG, SG-EGFIand SG-EGFⅡ(P>0.05).Conclusion: EGF may play an important role in the regulation of spermatogenesis. Serum EGF concentration and high expression of EGF-R in Leydig cells have a positive correlation with spermatogenic function of the testes.

  20. From signal to form: Nod factor as a morhogenetic signal molecule to induce symbiotic responses in legume root hairs

    NARCIS (Netherlands)

    Esseling, J.J.

    2004-01-01

    In this thesis, research is presented which contributes to a better understanding of nod factor (NF) induced signalling in Iegume root hairs, leading to a successful symbiosis. We mainly use root hairs of the model Iegume Medicago truncatula ('barrel medic') as an experimental system. In the differe

  1. From signal to form: Nod factor as a morhogenetic signal molecule to induce symbiotic responses in legume root hairs

    NARCIS (Netherlands)

    Esseling, J.J.

    2004-01-01

    In this thesis, research is presented which contributes to a better understanding of nod factor (NF) induced signalling in Iegume root hairs, leading to a successful symbiosis. We mainly use root hairs of the model Iegume Medicago truncatula ('barrel medic') as an experimental system. In the

  2. Wolbachia as an infectious extrinsic factor manipulating host signalling pathways

    Directory of Open Access Journals (Sweden)

    Ilaria eNegri

    2012-01-01

    Full Text Available Wolbachia pipientis is a widespread endosymbiont of filarial nematodes and arthropods. While in worms the symbiosis is obligate, in arthropods Wolbachia induces several reproductive manipulations (i.e. cytoplasmic incompatibility, parthenogenesis, feminization of genetic males and male-killing in order to increase the number of infected females. These various phenotypic effects may be linked to differences in host physiology, and in particular to endocrine-related processes governing growth, development and reproduction. Indeed, a number of evidences links Wolbachia symbiosis to insulin and ecdysteroid signalling, two multilayered pathways known to work antagonistically, jointly or even independently for the regulation of different molecular networks. At present it is not clear whether Wolbachia manipulates one pathway, thus affecting other related metabolic networks, or if it targets both pathways, even interacting at several points in each of them. Interestingly, in view of the interplay between hormone signalling and epigenetic machinery, a direct influence of the infection on hormonal signalling involving ecdysteroids might be achievable through the manipulation of the host’s epigenetic pathways.

  3. Transactivation of epidermal growth factor receptor in vascular and renal systems in rats with experimental hyperleptinemia: role in leptin-induced hypertension.

    Science.gov (United States)

    Jamroz-Wiśniewska, Anna; Wójcicka, Grazyna; Łowicka, Ewelina; Ksiazek, Marta; Bełtowski, Jerzy

    2008-04-15

    We examined the role of epidermal growth factor (EGF) receptor in the pathogenesis of leptin-induced hypertension in the rat. Leptin, administered in increasing doses (0.1-0.5 mg/kg/day) for 10 days, increased phosphorylation levels of non-receptor tyrosine kinase, c-Src, EGF receptor and extracellular signal-regulated kinases (ERK) in aorta and kidney, which was accompanied by the increase in plasma concentration and urinary excretion of isoprostanes and H2O2. Blood pressure and renal Na+,K+-ATPase activity were higher, whereas urinary sodium excretion was lower in animals receiving leptin. The effects of leptin on renal Na+,K+-ATPase, natriuresis and blood pressure were abolished by NADPH oxidase inhibitor, apocynin, Src kinase inhibitor, PP2, EGF receptor inhibitor, AG1478, protein farnesyltransferase inhibitor, manumycin A, and ERK inhibitor, PD98059. In contrast, inhibitors of insulin-like growth factor-1 and platelet-derived growth factor receptors, AG1024 and AG1295, respectively, only slightly reduced ERK phosphorylation and had no effect on blood pressure in rats receiving leptin. These data indicate that: (1) experimental hyperleptinemia is associated with oxidative stress and c-Src-dependent transactivation of the EGF receptor, which stimulates ERK in vascular wall and the kidney, (2) overactivity of EGF receptor-ERK pathway contributes to leptin-induced hypertension by stimulating renal Na+,K+-ATPase and reducing sodium excretion, (3) inhibitors of c-Src, EGF receptor and ERK may be considered as a novel therapy for hypertension associated with hyperleptinemia, e.g. in patients with obesity and metabolic syndrome.

  4. The urinary excretion of epidermal growth factor in the rat is reduced by aprotinin, a proteinase inhibitor

    DEFF Research Database (Denmark)

    Jørgensen, P E; Raaberg, Lasse; Poulsen, Steen Seier

    1990-01-01

    The present study on the rat shows that i.v. administration of the proteinase inhibitor aprotinin reduces the urinary output of immunoreactive epidermal growth factor (EGF) while the amount of immunoreactive EGF in the kidneys is increased. This indicates that the EGF-precursor in the rat kidney ...

  5. Effects of epidermal growth factor on glycolysis in A431 cells.

    Science.gov (United States)

    Baulida, J; Onetti, R; Bassols, A

    1992-03-31

    A431 cells were treated with epidermal growth factor (EGF) to study the mechanism by which this factor accelerates the glycolytic flux. After EGF treatment, fructose-2,6-bisphosphate (Fru-2,6-P2) levels rose up to 2-fold. This change correlated with an increase in phosphofructokinase-2 activity, which was not due to a change in the transcription or translation of the enzyme, neither in the amount of enzyme. PK-C does not appear to be involved in the signalling mechanism since EGF was equally potent in PK-C depleted cells than in control cells. The increase in Fru-2,6-P2 levels was lower and more transient in cells treated with EGF in a calcium-free medium than in the presence of the cation, and it was restored by the addition of calcium to the medium. These results suggest a possible role for calcium-mediated pathways in the control of Fru-2,6-P2 levels in A431 cells.

  6. Clinical development and perspectives of CIMAvax EGF, Cuban vaccine for non-small-cell lung cancer therapy.

    Science.gov (United States)

    Rodríguez, Pedro C; Rodríguez, Gryssell; González, Gisela; Lage, Agustín

    2010-01-01

    Introducción CIMAvax EGF es una vacuna terapéutica contra el cáncer enteramente desarrollada en Cuba y licenciada en el país para su uso en pacientes adultos con cáncer de pulmón de células no pequeñas (CPCNP) en etapas IIIB/IV. La vacuna se basa en la inmunoterapia activa; o sea, manipula la respuesta inmune de un individuo para que genere sus propios anticuerpos efectores (Acs) contra el factor de crecimiento epidérmico (EGF). Objetivo Revisar los estudios clínicos y preclínicos realizados durante el desarrollo de CIMAvax EGF, principalmente los publicados por investigadores cubanos en revistas científicas internacionales arbitradas. Métodos Se efectuó una búsqueda automatizada en PubMed con el uso de las palabras claves “vacuna” y “EGF”, que dio como resultado 17 artículos publicados por autores cubanos entre el 1 de enero de 1994 y el 30 de septiembre del 2009. Se describieron y discutieron los principales resultados, junto con los hallazgos preliminares no publicados aún de un ensayo clínico inicial fase III en ejecución. Resultados Los artículos revisados describen cinco ensayos clínicos fase I/II y uno fase II realizados en Cuba de 1995–2005. Un estudio no controlado de 1995–1996 fue la primera evidencia científicas de la factibilidad de inducir una respuesta inmune contra el EGF autólogo en pacientes con diferentes tumores en etapas avanzadas. Ensayos posteriores controlados y aleatorizados incluyeron pacientes con CPCNP en etapas avanzadas (IIIB/IV). En los ensayos segundo y tercero de fase I/ II, los pacientes inmunizados se diferenciaron en buenos respondedores (BR) y malos respondedores (MR) según las respuestas de anticuerpos contra el EGF y se conformó mayor inmunogenicidad al utilizar el adyuvante Montanide ISA 51 en la formulación vacunal, así como los beneficios del tratamiento de ciclofosfamida a baja dosis 72 horas antes de la primera inmunización. En el cuarto ensayo fase I/II se encontró un aumento de la

  7. WRKY Transcription Factors: Key Components in Abscisic Acid Signaling

    Science.gov (United States)

    2011-01-01

    2008). In cereals, upon imbibing, the embryos of nondormant seeds produce GA. This GA is transported to the aleurone, a thin layer of cells surround- ing...sensing, signaling and transport . Plant Cell Physiol. 51, 1821–1839. Urano, K., Kurihara, Y., Seki, M. and Shinozaki, K. (2010) ‘Omics’ analyses of...galactinol synthase (BhGolS1) promoter. Planta , 230, 1155–1166. Wu, F.-Q., Xin, Q., Cao, Z., Liu, Z.-Q., Du, S.-Y., Mei, C., Zhao, C.-X., Wang, X.-F

  8. Yamanaka factors critically regulate the developmental signaling network in mouse embryonic stem cells

    Institute of Scientific and Technical Information of China (English)

    Xiaosong Liu; Jinyan Huang; Taotao Chen; Ying Wang; Shunmei Xin; Jian Li; Gang Pei; Jiuhong Kang

    2008-01-01

    Yamanaka factors (Oct3/4,Sox2,KIf4,c-Myc) are highly expressed in embryonic stem (ES) cells,and their overexpression can induce pluripotency in both mouse and human somatic cells,indicating that these factors regulate the developmental signaling network necessary for ES cell pluripotency.However,systemic analysis of the signaling pathways regulated by Yamanaka factors has not yet been fully described.In this study,we identified the target promoters of endogenous Yamanaka factors on a whole genome scale using ChIP (chromatin immunoprecipitation)-on-chip in E14.1 mouse ES cells,and we found that these four factors co-occupied 58 promoters.Interestingly,when Oct4 and Sox2 were analyzed as core factors,Kif4 functioned to enhance the core factors for development regulation,whereas c-Myc seemed to play a distinct role in regulating metabolism.The pathway analysis revealed that Yamanaka factors collectively regulate a developmental signaling network composed of 16 developmental signaling pathways,nine of which represent earlier unknown pathways in ES cells,including apoptosis and cellcycle pathways.We further analyzed data from a recent study examining Yamanaka factors in mouse ES cells.Interestingly,this analysis also revealed 16 developmental signaling pathways,of which 14 pathways overlap with the ones revealed by this study,despite that the target genes and the signaling pathways regulated by each individual Yamanaka factor differ significantly between these two datasets.We suggest that Yamanaka factors critically regulate a developmental signaling network composed of approximately a dozen crucial developmental signaling pathways to maintain the pluripotency of ES cells and probably also to induce pluripotent stem cells.

  9. TGFβ loss activates ADAMTS-1-mediated EGF-dependent invasion in a model of esophageal cell invasion

    Energy Technology Data Exchange (ETDEWEB)

    Le Bras, Grégoire F.; Taylor, Chase; Koumangoye, Rainelli B. [Department of Surgery, Vanderbilt University, Nashville, TN (United States); Revetta, Frank [Department of Pathology, Vanderbilt University, Nashville, TN (United States); Loomans, Holli A. [Department of Cancer Biology, Vanderbilt University, Nashville, TN (United States); Andl, Claudia D., E-mail: claudia.andl@vanderbilt.edu [Department of Surgery, Vanderbilt University, Nashville, TN (United States); Department of Cancer Biology, Vanderbilt University, Nashville, TN (United States); Department of Vanderbilt Ingram Cancer Center, Vanderbilt University, Nashville, TN (United States)

    2015-01-01

    The TGFβ signaling pathway is essential to epithelial homeostasis and is often inhibited during progression of esophageal squamous cell carcinoma. Recently, an important role for TGFβ signaling has been described in the crosstalk between epithelial and stromal cells regulating squamous tumor cell invasion in mouse models of head-and-neck squamous cell carcinoma (HNSCC). Loss of TGFβ signaling, in either compartment, leads to HNSCC however, the mechanisms involved are not well understood. Using organotypic reconstruct cultures (OTC) to model the interaction between epithelial and stromal cells that occur in dysplastic lesions, we show that loss of TGFβ signaling promotes an invasive phenotype in both fibroblast and epithelial compartments. Employing immortalized esophageal keratinocytes established to reproduce common mutations of esophageal squamous cell carcinoma, we show that treatment of OTC with inhibitors of TGFβ signaling (A83-01 or SB431542) enhances invasion of epithelial cells into a fibroblast-embedded Matrigel/collagen I matrix. Invasion induced by A83-01 is independent of proliferation but relies on protease activity and expression of ADAMTS-1 and can be altered by matrix density. This invasion was associated with increased expression of pro-inflammatory cytokines, IL1 and EGFR ligands HB-EGF and TGFα. Altering EGF signaling prevented or induced epithelial cell invasion in this model. Loss of expression of the TGFβ target gene ROBO1 suggested that chemorepulsion may regulate keratinocyte invasion. Taken together, our data show increased invasion through inhibition of TGFβ signaling altered epithelial-fibroblasts interactions, repressing markers of activated fibroblasts, and altering integrin-fibronectin interactions. These results suggest that inhibition of TGFβ signaling modulates an array of pathways that combined promote multiple aspects of tumor invasion. - Highlights: • Chemical inhibition of TGFβ signaling advances collective invasion

  10. Transforming growth factor alpha and epidermal growth factor in laryngeal carcinomas demonstrated by immunohistochemistry

    DEFF Research Database (Denmark)

    Christensen, M E; Therkildsen, M H; Poulsen, Steen Seier

    1993-01-01

    Fifteen laryngeal squamous cell carcinomas were investigated for the presence of transforming growth factor alpha (TGF-alpha) and epidermal growth factor (EGF) using immunohistochemical methods. In a recent study the same material was characterized for epidermal growth factor receptors (EGF recep...

  11. Signalling by Transforming Growth Factor Beta Isoforms in Wound Healing and Tissue Regeneration

    Directory of Open Access Journals (Sweden)

    Richard W.D. Gilbert

    2016-06-01

    Full Text Available Transforming growth factor beta (TGFβ signalling is essential for wound healing, including both non-specific scar formation and tissue-specific regeneration. Specific TGFβ isoforms and downstream mediators of canonical and non-canonical signalling play different roles in each of these processes. Here we review the role of TGFβ signalling during tissue repair, with a particular focus on the prototypic isoforms TGFβ1, TGFβ2, and TGFβ3. We begin by introducing TGFβ signalling and then discuss the role of these growth factors and their key downstream signalling mediators in determining the balance between scar formation and tissue regeneration. Next we discuss examples of the pleiotropic roles of TGFβ ligands during cutaneous wound healing and blastema-mediated regeneration, and how inhibition of the canonical signalling pathway (using small molecule inhibitors blocks regeneration. Finally, we review various TGFβ-targeting therapeutic strategies that hold promise for enhancing tissue repair.

  12. Immunoreactive transforming growth factor alpha and epidermal growth factor in oral squamous cell carcinomas

    DEFF Research Database (Denmark)

    Therkildsen, M H; Poulsen, Steen Seier; Bretlau, P

    1993-01-01

    , the cells above the basal cell layer were positive for both TGF-alpha and EGF. The same staining pattern was observed in oral mucosa obtained from healthy persons. In moderately to well differentiated carcinomas, the immunoreactivity was mainly confined to the cytologically more differentiated cells, thus......Forty oral squamous cell carcinomas have been investigated immunohistochemically for the presence of transforming growth factor alpha (TGF-alpha) and epidermal growth factor (EGF). The same cases were recently characterized for the expression of EGF-receptors. TGF-alpha was detected...... with a monoclonal mouse antibody and EGF with polyclonal rabbit antiserum. Thirty-five of the tumours were positive for TGF-alpha and 26 of the tumours for EGF. None of the poorly differentiated tumours was positive for EGF, but they all were for TGF-alpha. In sections including normal differentiated oral mucosa...

  13. EGF stimulates Pit-1 independent transcription of the human prolactin pituitary promoter in human breast cancer SK-BR-3 cells through its proximal AP-1 response element.

    Science.gov (United States)

    Manfroid, Isabelle; Van de Weerdt, Cécile; Baudhuin, Ariane; Martial, Joseph A; Muller, Marc

    2005-01-14

    Normal and neoplastic human mammary gland cells are targets for the proliferative action of prolactin. These cells also synthesize prolactin, thereby inducing an autocrine/paracrine proliferative loop. We present the first extensive analysis of the transcriptional regulation of the human prolactin gene (hPRL) in human mammary tumor cells, SK-BR-3. We show that the pituitary promoter is functional in these cells in the absence of the pituitary-specific factor Pit-1. Expression of exogenous Pit-1 or epidermal growth factor (EGF) treatment stimulates the transfected hPRL pituitary promoter and the endogenous hPRL expression. EGF stimulation is mediated by increased synthesis of c-fos and c-jun, resulting in AP-1 binding to the proximal hPRL pituitary promoter. This regulation involves the EGF receptor, possibly ErbB2 that is highly expressed in SK-BR-3 cells, and a PI3K/JNK pathway. The stimulation of hPRL gene transcription by EGF in mammary cells may include hPRL in a complex regulatory network controlling growth of human mammary cells.

  14. Buccal mucosal ulcer healing effect of rhEGF/Eudispert hv hydrogel.

    Science.gov (United States)

    Park, Jeong Sook; Yoon, Joon Il; Li, Hong; Moon, Dong Cheul; Han, Kun

    2003-08-01

    We have studied the effect of rhEGF on the buccal mucosal ulcer healing. rhEGF was rapidly degraded upon incubation with the hamster buccal mucosal homogenates; The degradation of rhEGF was significantly inhibited by sodium lauryl sulfate (SLS). Eudispert hv hydrogel and Polycarbophil 974P hydrogel were prepared for rhEGF delivery and their mucoadhesiveness was measured by the Instron method. The mucoadhesive force of Eudispert hv was significantly greater than that of Polycarbophil 974P. Moreover, rhEGF in Eudispert hv hydrogel remained stable for about 2 months. To evaluate the ulcer healing effect of rhEGF, the buccal mucosal ulcer was induced in golden hamsters using acetic acid. At 24 h after administration of rhEGF/Eudispert hv hydrogel, the ulcerous area was decreased compared with rhEGF solution and, as a result, the curative ratio was 36.8 +/- 5.68%. By the addition of SLS (0.5%) to Eudispert hv hydrogel, the curative ratio increased 1.5 times. The mechanism of the action was probably due to a combination of protection of the drug against proteases present in mucosa and prolongation of the release of rhEGF from the formulation at the site of action.

  15. Rationale for targeting fibroblast growth factor receptor signaling in breast cancer

    OpenAIRE

    André, Fabrice; Cortés, Javier

    2015-01-01

    Fibroblast growth factor receptor (FGFR) signaling is involved in multiple biological processes, including cell proliferation, survival, differentiation, migration, and apoptosis during embryonic development and adult tissue homeostasis. Given its role in the activation of critical signaling pathways, aberrant FGFR signaling has been implicated in multiple cancer types. A comprehensive search of PubMed and congress abstracts was conducted to identify reports on FGFR pathway components in brea...

  16. Relationship between induction of phosphorylated H2AX and survival in breast cancer cells exposed to 111In-DTPA-hEGF.

    Science.gov (United States)

    Cai, Zhongli; Chen, Zhuo; Bailey, Kristy E; Scollard, Deborah A; Reilly, Raymond M; Vallis, Katherine A

    2008-08-01

    The Auger electron-emitting radiopharmaceutical 111In-diethylenetriaminepentaacetic acid human epidermal growth factor (111In-DTPA-hEGF) binds the epidermal growth factor receptor (EGFR), is internalized, and translocates to the nucleus. The purpose of this study was to investigate the relationship between EGFR expression, DNA damage, and cytotoxicity in cells exposed to 111In-DTPA-hEGF. Breast cancer cell lines with a range of EGFR expression levels were exposed to 111In-DTPA-hEGF or gamma-radiation. The cell lines (followed by number of EGFR per cell in parentheses) were MDA-MB-468 (1.3 x 10(6)), MDA-MB-231 (1.3 x 10(5)), and MCF-7 (1.5 x 10(4)). The proportion of radioactivity partitioning into the nucleus was measured by cell fractionation. DNA double-strand breaks were evaluated using the gamma-H2AX assay. Clonogenic survival assays were used to measure cytotoxicity. All data are presented as mean +/- SD. The amount of 111In-DTPA-hEGF that translocated to the nucleus (in mBq/nucleus) in MDA-MB-468, MDA-MB-231, and MCF-7 cells incubated with 111In-DTPA-hEGF (5.2 MBq/mL, 43 nM) for 20 h was 131 +/- 6, 8.1 +/- 0.1, and 1.1 +/- 0.9, respectively. The number of gamma-H2AX foci per nucleus was 35 +/- 15, 19 +/- 10, and 1.7 +/- 0.3, respectively. A reduction in the surviving fraction (SF) in MDA-MB-468 (0.013 +/- 0.001) and MDA-MB-231 (0.5 +/- 0.1) but not in MCF-7 cells after exposure to 111In-DTPA-hEGF (5.2 MBq/mL, 43 nM) for 20 h has been demonstrated. The SF of MDA-MB-468 cells after exposure to DTPA-EGF (43 nM) and 111In-acetate (5.2 MBq/mL) for 20 h was 0.5 +/- 0.1 and 0.53 +/- 0.05, respectively. MDA-MB-468 was the most sensitive of the cell lines to gamma-irradiation, with an SF after 2 Gy of 0.45 +/- 0.04, compared with 0.7 +/- 0.1 and 0.8 +/- 0.1 for MCF-7 and MDA-MB-231, respectively. The number of gamma-H2AX foci per nucleus in MDA-MB-468 cells correlated with the concentration, specific activity, and incubation time of 111In-DTPA-hEGF. DNA damage caused

  17. Supramolecular Nanofibers Enhance Growth Factor Signaling by Increasing Lipid Raft Mobility.

    Science.gov (United States)

    Newcomb, Christina J; Sur, Shantanu; Lee, Sungsoo S; Yu, Jeong Min; Zhou, Yan; Snead, Malcolm L; Stupp, Samuel I

    2016-05-11

    The nanostructures of self-assembling biomaterials have been previously designed to tune the release of growth factors in order to optimize biological repair and regeneration. We report here on the discovery that weakly cohesive peptide nanostructures in terms of intermolecular hydrogen bonding, when combined with low concentrations of osteogenic growth factor, enhance both BMP-2 and Wnt mediated signaling in myoblasts and bone marrow stromal cells, respectively. Conversely, analogous nanostructures with enhanced levels of internal hydrogen bonding and cohesion lead to an overall reduction in BMP-2 signaling. We propose that the mechanism for enhanced growth factor signaling by the nanostructures is related to their ability to increase diffusion within membrane lipid rafts. The phenomenon reported here could lead to new nanomedicine strategies to mediate growth factor signaling for translational targets.

  18. Supramolecular Nanofibers Enhance Growth Factor Signaling by Increasing Lipid Raft Mobility

    Energy Technology Data Exchange (ETDEWEB)

    Newcomb, Christina J.; Sur, Shantanu; Lee, Sungsoo S.; Yu, Jeong Min; Zhou, Yan; Snead, Malcolm L.; Stupp, Samuel I.

    2016-04-12

    The nanostructures of self-assembling biomaterials have been previously designed to tune the release of growth factors in order to optimize biological repair and regeneration. We report here on the discovery that weakly cohesive peptide nanostructures in terms of intermolecular hydrogen bonding, when combined with low concentrations of osteogenic growth factor, enhance both BMP-2 and Wnt mediated signaling in myoblasts and bone marrow stromal cells, respectively. Conversely, analogous nanostructures with enhanced levels of internal hydrogen bonding and cohesion lead to an overall reduction in BMP-2 signaling. We propose that the mechanism for enhanced growth factor signaling by the nanostructures is related to their ability to increase diffusion within membrane lipid rafts. The phenomenon reported here could lead to new nanomedicine strategies to mediate growth factor signaling for translational targets.

  19. Towards the systematic discovery of signal transduction networks using phosphorylation dynamics data

    Directory of Open Access Journals (Sweden)

    Yachie Nozomu

    2010-05-01

    Full Text Available Abstract Background Phosphorylation is a ubiquitous and fundamental regulatory mechanism that controls signal transduction in living cells. The number of identified phosphoproteins and their phosphosites is rapidly increasing as a result of recent mass spectrometry-based approaches. Results We analyzed time-course phosphoproteome data obtained previously by liquid chromatography mass spectrometry with the stable isotope labeling using amino acids in cell culture (SILAC method. This provides the relative phosphorylation activities of digested peptides at each of five time points after stimulating HeLa cells with epidermal growth factor (EGF. We initially calculated the correlations between the phosphorylation dynamics patterns of every pair of peptides and connected the strongly correlated pairs to construct a network. We found that peptides extracted from the same intracellular fraction (nucleus vs. cytoplasm tended to be close together within this phosphorylation dynamics-based network. The network was then analyzed using graph theory and compared with five known signal-transduction pathways. The dynamics-based network was correlated with known signaling pathways in the NetPath and Phospho.ELM databases, and especially with the EGF receptor (EGFR signaling pathway. Although the phosphorylation patterns of many proteins were drastically changed by the EGF stimulation, our results suggest that only EGFR signaling transduction was both strongly activated and precisely controlled. Conclusions The construction of a phosphorylation dynamics-based network provides a useful overview of condition-specific intracellular signal transduction using quantitative time-course phosphoproteome data under specific experimental conditions. Detailed prediction of signal transduction based on phosphoproteome dynamics remains challenging. However, since the phosphorylation profiles of kinase-substrate pairs on the specific pathway were localized in the dynamics

  20. Cetuximab in combination with anti-human IgG antibodies efficiently down-regulates the EGF receptor by macropinocytosis

    Energy Technology Data Exchange (ETDEWEB)

    Berger, Christian [Department of Pathology, Oslo University Hospital, Rikshospitalet, Post box 4950 Nydalen, 0424 Oslo (Norway); Madshus, Inger Helene [Institute of Pathology, University of Oslo, Rikshospitalet, 0027 Oslo (Norway); Department of Pathology, Oslo University Hospital, Rikshospitalet, Post box 4950 Nydalen, 0424 Oslo (Norway); Stang, Espen, E-mail: espsta@rr-research.no [Department of Pathology, Oslo University Hospital, Rikshospitalet, Post box 4950 Nydalen, 0424 Oslo (Norway)

    2012-12-10

    The monoclonal antibody C225 (Cetuximab) blocks binding of ligand to the epidermal growth factor receptor (EGFR). In addition, it is known that incubation with C225 induces endocytosis of the EGFR. This endocytosis has previously been shown to be increased when C225 is combined with an additional monoclonal anti-EGFR antibody. However, the effects of antibody combinations on EGFR activation, endocytosis, trafficking and degradation have been unclear. By binding a secondary antibody to the C225-EGFR complex, we here demonstrate that a combination of antibodies can efficiently internalize and degrade the EGFR. Although the combination of antibodies activated the EGFR kinase and induced ubiquitination of the EGFR, the kinase activity was not required for internalization of the EGFR. In contrast to EGF-induced EGFR down-regulation, the antibody combination efficiently degraded the EGFR without initiating downstream proliferative signaling. The antibody-induced internalization of EGFR was found not to depend on clathrin and/or dynamin, but depended on actin polymerization, suggesting induction of macropinocytosis. Macropinocytosis may cause internalization of large membrane areas, and this could explain the highly efficient internalization of the EGFR induced by combination of antibodies. -- Highlight: Black-Right-Pointing-Pointer Cetuximab induced endocytosis of EGFR increases upon combination with anti-human IgG. Black-Right-Pointing-Pointer Antibody combination causes internalization of EGFR by macropinocytosis. Black-Right-Pointing-Pointer Antibody-induced internalization of EGFR is independent of EGFR kinase activity. Black-Right-Pointing-Pointer Antibody combination may have a zipper effect and cross-link EGFRs on neighboring cells.

  1. Development of a human epidermal growth factor derivative with EGFR-blocking and depleted biological activities: A comparative in vitro study using EGFR-positive breast cancer cells.

    Science.gov (United States)

    Mehrabi, Masomeh; Mansouri, Kamran; Soleymani, Bijan; Hoseinkhani, Zohreh; Shahlaie, Mohsen; Khodarahmi, Reza

    2017-10-01

    Epidermal growth factor (EGF) is a local growth factor that stimulates cell growth, proliferation, and differentiation by binding to its receptor EGFR. EGF and EGFR are involved in many aspects of the development of carcinomas. Because EGFR has been found to be over-expressed in many tumors of epithelial origin, it is a potential target for antitumor therapy. In this study we designed a mutated form of hEGF (mEGF) with a deletion of four amino acids residues (Gln(43), Tyr(44), Arg(45) and Asp(46)) in order to show importance of Leu spatial location for EGFR binding/activation. Expression vector pET32a(+) and E. Coli, strain Rosetta-gami B (DE3) were used to enhance solubility of the recombinant protein with yielding approximately 10mg/l of cell culture. The purified cleaved hEGF as well as non-cleaved fusion protein were biologically active, which was confirmed by their equal ability to stimulate proliferation of MCF7 cells. The mEGF showed specificity and high affinity for EGFR binding, however binding affinity of mEGF for EGFR was reduced about 11.5 fold compared with that of hEGF. The mEGF effect on the MCF7 cell proliferation had a relatively different outcome; mEGF simulated differential cell growth in a dose dependent manner. On the other hand, in MDA-MB468 cells, hEGF and mEGF induced growth inhibition, which was much more severe for hEGF than that of mEGF. Also, hEGF strongly induced the phosphorylation of EGF receptor in MDA-MB468 cells while mEGF induced poor EGFR phosphorylation. The same observations were also made for migration of cancer cells, especially induction of MDA-MB468 migration by mEGF was significantly lower than that of hEGF, suggesting a connection between tyrosine phosphorylation of EGFR and cell migration. Docking analysis revealed that the binding affinity and the buried surface area of mEGF to EGFR complex are lower than those of hEGF/EGFR. Although theoretical studies confirmed reduction in mEGF-EGFR binding affinity, the data of the

  2. Mechanism of divergent growth factor effects in mesenchymal stem cell differentiation

    DEFF Research Database (Denmark)

    Kratchmarova, Irina; Blagoev, Blagoy; Haack-Sorensen, M.

    2005-01-01

    Closely related signals often lead to very different cellular outcomes. We found that the differentiation of human mesenchymal stem cells into bone-forming cells is stimulated by epidermal growth factor (EGF) but not platelet-derived growth factor (PDGF). We used mass spectrometry-based proteomics...... it as a possible control point. Indeed, chemical inhibition of PI3K in PDGF-stimulated cells removed the differential effect of the two growth factors, bestowing full differentiation effect onto PDGF. Thus, quantitative proteomics can directly compare entire signaling networks and discover critical differences...... capable of changing cell fate....

  3. Epidermal growth factor receptor expression in urinary bladder cancer

    Directory of Open Access Journals (Sweden)

    Dayalu S.L. Naik

    2011-01-01

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

  4. Effects of (-)-Epigallocatechin gallate on some protein factors involved in the epidermal growth factor receptor signaling pathway

    Institute of Scientific and Technical Information of China (English)

    Yinjiu Huang; Ruiqing Xu; Baoan Song; Song Yang; Li Zhao; Shouwei Wua

    2009-01-01

    (-)-Epigallocatechin gallate (EGCG), a major polyphenolic constituent of green tea, can inhibit activity of specific receptor tyrosine kinases (RTKs) and related downstream signal transduction pathways, resulting in the control of unwanted cell proliferation. The epidermal growth factor receptor (EGFR) signaling pathway is one of the most important pathways that regulates growth, survival, proliferation and differentiation in mammalian cells. This review addresses the effects of EGCG on some protein factors involved in the EGFR signaling pathway in a direct or indirect manner. Based on our understanding of the interaction between EGCG and these factors, and based on their structures, EGCG could be used as a lead compound for designing and synthesizing novel drugs with significant biological activity.

  5. [INHIBITORS OF MAP-KINASE PATHWAY U0126 AND PD98059 DIFFERENTLY AFFECT ORGANIZATION OF TUBULIN CYTOSKELETON AFTER STIMULATION OF EGF RECEPTOR ENDOCYTOSIS].

    Science.gov (United States)

    Zlobina, M V; Steblyanko, Yu Yu; Shklyaeva, M A; Kharchenko, V V; Salova, A V; Kornilova, E S

    2015-01-01

    phospho-ERK2 could be detected after 60 min of endocytosis. In both cases, MAP-kinase activation dynamics was significantly different from the control. Our results suggest involvement of EGF-stimulated MAP-kinase pathway in cytoskeleton regulation. At the same time, they demonstrate that the two studied and widely used inhibitors are not equivalent with respect to not only the effect on MAP-kinase activity but also to such interdependent processes such as changes in cytoskeleton organization and signaling receptor' endocytosis.

  6. Binding of sFRP-3 to EGF in the extra-cellular space affects proliferation, differentiation and morphogenetic events regulated by the two molecules.

    Directory of Open Access Journals (Sweden)

    Raffaella Scardigli

    Full Text Available BACKGROUND: sFRP-3 is a soluble antagonist of Wnts, widely expressed in developing embryos. The Wnt gene family comprises cysteine-rich secreted ligands that regulate cell proliferation, differentiation, organogenesis and oncogenesis of different organisms ranging from worms to mammals. In the canonical signal transduction pathway Wnt proteins bind to the extracellular domain of Frizzled receptors and consequently recruit Dishevelled (Dsh to the cell membrane. In addition to Wnt membrane receptors belonging to the Frizzled family, several other molecules have been described which share homology in the CRD domain and lack the putative trans-membrane domain, such as sFRP molecules (soluble Frizzled Related Protein. Among them, sFRP-3 was originally isolated from bovine articular cartilage and also as a component of the Spemann organizer. sFRP-3 blocks Wnt-8 induced axis duplication in Xenopus embryos and binds to the surface of cells expressing a membrane-anchored form of Wnt-1. Injection of sFRP-3 mRNA blocks expression of XMyoD mRNA and leads to embryos with enlarged heads and shortened trunks. METHODOLOGY/PRINCIPAL FINDINGS: Here we report that sFRP-3 specifically blocks EGF-induced fibroblast proliferation and foci formation. Over-expression of sFRP-3 reverts EGF-mediated inhibition of hair follicle development in the mouse ectoderm while its ablation in Xenopus maintains EGF-mediated inhibition of ectoderm differentiation. Conversely, over-expression of EGF reverts the inhibition of somitic myogenesis and axis truncation in Xenopus and mouse embryos caused by sFRP-3. In vitro experiments demonstrated a direct binding of EGF to sFRP-3 both on heparin and on the surface of CHO cells where the molecule had been membrane anchored. CONCLUSIONS/SIGNIFICANCE: sFRP-3 and EGF reciprocally inhibit their effects on cell proliferation, differentiation and morphogenesis and indeed are expressed in contiguous domains of the embryo, suggesting that in

  7. Sulindac metabolites induce proteosomal and lysosomal degradation of the epidermal growth factor receptor.

    Science.gov (United States)

    Pangburn, Heather A; Ahnen, Dennis J; Rice, Pamela L

    2010-04-01

    The epidermal growth factor receptor (EGFR) is a member of the ErbB family of receptor tyrosine kinases. In response to ligand, EGFR is internalized and degraded by the ubiquitin-proteasome/lysosome pathway. We previously reported that metabolites of the nonsteroidal anti-inflammatory drug sulindac downregulate the expression of EGFR and inhibit basal and EGF-induced EGFR signaling through extracellular signal-regulated kinase 1/2. We now have evaluated the mechanisms of sulindac metabolite-induced downregulation of EGFR. EGF-induced downregulation of EGFR occurs within 10 minutes and lasts for 24 hours. By contrast, downregulation of EGFR by sulindac sulfide and sulindac sulfone was first evident at 4 and 24 hours, respectively, with maximal downregulation at 72 hours. Pretreatment with either the lysosomal inhibitor chloroquine or the proteosomal inhibitor MG132 blocked sulindac metabolite-induced downregulation of EGFR. Sulindac metabolites also increased the ubiquitination of EGFR. Whereas sulindac metabolites inhibited phosphorylation of EGFR pY1068, they increased phosphorylation of EGFR pY1045, the docking site where c-Cbl binds, thereby enabling receptor ubiquitination and degradation. Immunofluorescence analysis of EGF and EGFR distribution confirmed the biochemical observations that sulindac metabolites alter EGFR localization and EGFR internalization in a manner similar to that seen with EGF treatment. Expression of ErbB family members HER2 and HER3 was also downregulated by sulindac metabolites. We conclude that downregulation of EGFR expression by sulindac metabolites is mediated via lysosomal and proteosomal degradation that may be due to drug-induced phosphorylation at pY1045 with resultant ubiquitination of EGFR. Thus, sulindac metabolite-induced downregulation of EGFR seems to be mediated through mechanism(s) similar, at least in part, to those involved in EGF-induced downregulation of EGFR.

  8. Functions and Mechanisms of Fibroblast Growth Factor (FGF Signalling in Drosophila melanogaster

    Directory of Open Access Journals (Sweden)

    Hans-Arno J. Müller

    2013-03-01

    Full Text Available Intercellular signalling via growth factors plays an important role in controlling cell differentiation and cell movements during the development of multicellular animals. Fibroblast Growth Factor (FGF signalling induces changes in cellular behaviour allowing cells in the embryo to move, to survive, to divide or to differentiate. Several examples argue that FGF signalling is used in multi-step morphogenetic processes to achieve and maintain a transitional state of the cells required for the control of cell fate. In the genetic model Drosophila melanogaster, FGF signalling via the receptor tyrosine kinases Heartless (Htl and Breathless (Btl is particularly well studied. These FGF receptors affect gene expression, cell shape and cell–cell interactions during mesoderm layer formation, caudal visceral muscle (CVM formation, tracheal morphogenesis and glia differentiation. Here, we will address the current knowledge of the biological functions of FGF signalling in the fly on the tissue, at a cellular and molecular level.

  9. Control of Mammary Differentiation by Ras-Dependent Signal Transduction Pathways

    Science.gov (United States)

    2005-05-01

    include anti-Stat5, sc-835 ( SantaCruz Bio- with EGF reversed the EGF-induced inhibition of the technology, Santa Cruz, CA), anti-phosphoStat5 (Cell...anti-Stat5, sc-835 producible experiment indicated that DIP stimulation ( SantaCruz ), anti-phosphoStat5 (Cell Signaling), anti- in the presence of the

  10. TGF-β and EGF induced HLA-I downregulation is associated with epithelial-mesenchymal transition (EMT) through upregulation of snail in prostate cancer cells.

    Science.gov (United States)

    Chen, Xiao-Hui; Liu, Zong-Cai; Zhang, Ge; Wei, Wei; Wang, Xiao-Xiong; Wang, Hao; Ke, Hong-Peng; Zhang, Fan; Wang, Hong-Sheng; Cai, Shao-Hui; Du, Jun

    2015-05-01

    Human leukocyte antigen class I antigens (HLA-I) is essential in immune response by presenting antigenic peptides to cytotoxic T lymphocytes. Downregulation of HLA-I is observed in primary and metastatic prostate cancers, which facilitates them escape from immune surveillance, thereby promotes prostate cancer progression. In addition, elevated level of growth factors like TGF-β or EGF in microenvironment is related to the prostate cancer deterioration. Thus, we wondered whether TGF-β or EGF was involved in the regulation of HLA-I during the development of prostate cancer cells. In this study, we demonstrated that TGF-β and EGF both downregulated the expression of HLA-I, thereby attenuated the cytotoxic T cell mediated lysis of prostate cancer cells. Next, we revealed that TGF-β and EGF induced downregulation of HLA-I is associated with classical epithelial-mesenchymal transition (EMT) morphological changes and expression profiles. We further illustrated that overexpression of Snail is crucial for HLA-I downregulation and its association with EMT. At last, we discussed that NF-κB/p65 is the plausible target for Snail to induce HLA-I downregulation. Taken together, this is the first evidence to reveal that both TGF-β and EGF can induce HLA-I downregulation which is then proven to be associated with EMT in prostate cancer cells. These discoveries provide a deeper understanding of growth factors induced immune escape and introduce potential therapeutic targets for prostate cancers. Copyright © 2015 Elsevier Ltd. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    Panagiotis A. Konstantinopoulos

    2007-01-01

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

  12. Immunohistochemical Characterization of Three Monoclonal Antibodies Raised against the Epidermal Growth Factor and Its Receptor in Non-Small-Cell Lung Cancer: Their Potential Use in the Selection of Patients for Immunotherapy

    Directory of Open Access Journals (Sweden)

    Charles E. Rengifo

    2013-01-01

    Full Text Available Adequate methods to identify which lung cancer patients are most likely to benefit from the targeted drugs against both epidermal growth factor receptor/epidermal growth factor (EGFR/EGF are needed. For this reason, we evaluated both the tissue reactivity of ior egf/r3 monoclonal antibody (Mab in human lung carcinomas and its biological activity in NCI-H125 cells. Additionally, we assessed the tissue expression of EGF using two Mabs, CB-EGF1 and CB-EGF2. The overexpression of EGFR was detected in 33.33% and 62.71% of small-cell lung carcinoma (SCLC and non-small-cell lung carcinoma (NSCLC, respectively. The ability of ior egf/r3 Mab to bind the extracellular domain of EGFR inhibiting cell proliferation and inducing apoptosis in NCI-H125 cells was also demonstrated. The EGF expression was observed in about 17% and 70% of SCLC and NSCLC, respectively. However, differences in the reactivity of CB-EGF1 and CB-EGF2 were evidenced. A dual expression of EGFR and EGF was observed in 16.67% and 57.63% of SCLC and NSCLC patients, respectively. But, a correlation between them was only obtained in NSCLC. Our results permit to recommend the development of diagnostic kits using ior egf/r3 and/or CB-EGF1 Mabs in order to achieve a better selection of patients to EGFR/EGF-targeting treatment.

  13. Immunohistochemical Characterization of Three Monoclonal Antibodies Raised against the Epidermal Growth Factor and Its Receptor in Non-Small-Cell Lung Cancer: Their Potential Use in the Selection of Patients for Immunotherapy.

    Science.gov (United States)

    Rengifo, Charles E; Blanco, Rancés; Blanco, Damián; Cedeño, Mercedes; Frómeta, Milagros; Calzado, Enrique Rengifo

    2013-01-01

    Adequate methods to identify which lung cancer patients are most likely to benefit from the targeted drugs against both epidermal growth factor receptor/epidermal growth factor (EGFR/EGF) are needed. For this reason, we evaluated both the tissue reactivity of ior egf/r3 monoclonal antibody (Mab) in human lung carcinomas and its biological activity in NCI-H125 cells. Additionally, we assessed the tissue expression of EGF using two Mabs, CB-EGF1 and CB-EGF2. The overexpression of EGFR was detected in 33.33% and 62.71% of small-cell lung carcinoma (SCLC) and non-small-cell lung carcinoma (NSCLC), respectively. The ability of ior egf/r3 Mab to bind the extracellular domain of EGFR inhibiting cell proliferation and inducing apoptosis in NCI-H125 cells was also demonstrated. The EGF expression was observed in about 17% and 70% of SCLC and NSCLC, respectively. However, differences in the reactivity of CB-EGF1 and CB-EGF2 were evidenced. A dual expression of EGFR and EGF was observed in 16.67% and 57.63% of SCLC and NSCLC patients, respectively. But, a correlation between them was only obtained in NSCLC. Our results permit to recommend the development of diagnostic kits using ior egf/r3 and/or CB-EGF1 Mabs in order to achieve a better selection of patients to EGFR/EGF-targeting treatment.

  14. Grb7 and Hax1 may colocalize partially to mitochondria in EGF treated SKBR3 cells and their interaction can affect Caspase3 cleavage of Hax1

    Science.gov (United States)

    Qian, Lei; Bradford, Andrew M.; Cooke, Peter H.; Lyons, Barbara A.

    2017-01-01

    Growth factor receptor bound protein 7 (Grb7) is a signal transducing adaptor protein that mediates specific protein-protein interactions in multiple signaling pathways. Grb7, with Grb10 and Grb14, are members of the Grb7 protein family. The topology of the Grb7 family members contains several protein-binding domains that facilitate the formation of protein complexes and high signal transduction efficiency. Grb7 has been found overexpressed in several types of cancers and cancer cell lines, and is presumed involved in cancer progression through promotion of cell proliferation and migration via interactions with the ErbB2 (HER2) receptor, FAK (focal adhesion kinase), Ras-GTPases, and other signaling partners. We previously reported Grb7 binds to Hax1 (HS1 associated protein X1) isoform 1, an anti-apoptotic protein also involved in cell proliferation and calcium homeostasis. In this study, we confirm the in vitro Grb7/Hax1 interaction is exclusive to these two proteins and their interaction does not depend on Grb7 dimerization state. In addition, we report Grb7 and Hax1 isoform 1 may colocalize partially to mitochondria in EGF treated SKBR3 cells and growth conditions can affect this colocalization. Moreover, Grb7 can affect Caspase3 cleavage of the Hax1 isoform 1 in vitro, and Grb7 expression may slow the Caspase3 cleavage of Hax1 isoform 1 in apoptotic HeLa cells. Finally, Grb7 is shown to increase cell viability in apoptotic HeLa cells in a time dependent manner. Taken together, these discoveries provide clues for the role of a Grb7/Hax1 protein interaction in apoptosis pathways involving Hax1. PMID:26869103

  15. Signals and Cells Involved in Regulating Liver Regeneration

    Directory of Open Access Journals (Sweden)

    Liang-I. Kang

    2012-12-01

    Full Text Available Liver regeneration is a complex phenomenon aimed at maintaining a constant liver mass in the event of injury resulting in loss of hepatic parenchyma. Partial hepatectomy is followed by a series of events involving multiple signaling pathways controlled by mitogenic growth factors (HGF, EGF and their receptors (MET and EGFR. In addition multiple cytokines and other signaling molecules contribute to the orchestration of a signal which drives hepatocytes into DNA synthesis. The other cell types of the liver receive and transmit to hepatocytes complex signals so that, in the end of the regenerative process, complete hepatic tissue is assembled and regeneration is terminated at the proper time and at the right liver size. If hepatocytes fail to participate in this process, the biliary compartment is mobilized to generate populations of progenitor cells which transdifferentiate into hepatocytes and restore liver size.

  16. 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 depend