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Sample records for receptor epidermal growth factor

  1. Epidermal growth factor receptor signaling in tissue

    SciTech Connect

    Shvartsman, Stanislav; Wiley, H. S.; Lauffenburger, Douglas A.

    2004-08-01

    Abstract: A peptide purified from the salivary gland of a mouse was shown few years ago to accelerate incisor eruption and eyelid opening in newborn mice, and was named epidermal growth factor (EGF). The members of this family of peptide growth factors had been identified in numerous physiological and pathological contexts. EGF binds to a cell surface EGF receptor, which induces a biochemical modification (phosphorylation) of the receptor's cytoplasmic tail. There is a growing consensus in the research community that, in addition to cellular and molecular studies, the dynamics of the EGFR network and its operation must be examined in tissues. A key challenge is to integrate the existing molecular and cellular information into a system-level description of the EGFR network at the tissue and organism level. In this paper, the two examples of EGFR signaling in tissues are described, and the recent efforts to model EGFR autocrine loops, which is a predominant mode of EGFR activation in vivo, are summarized.

  2. Epidermal growth factor receptors in the oesophagus.

    PubMed Central

    Jankowski, J; Murphy, S; Coghill, G; Grant, A; Wormsley, K G; Sanders, D S; Kerr, M; Hopwood, D

    1992-01-01

    The quantity and distribution of epidermal growth factor receptors (EGF-R) in oesophageal mucosa was studied in the oesophagus in order to determine its role in oesophageal disease. Fifty five biopsies were taken from different levels of the oesophagus in 25 consecutive patients undergoing endoscopy. Another group of eight patients with histologically proven Barrett's oesophagitis had a biopsy taken from the area of columnar lined oesophagus. A peripheral, membranous pattern was seen predominantly confined to the basal and immediately suprabasal cells in all of the first group of patients. In the superficial cells a few granular cytoplasmic structures were positive. All patients with Barrett's oesophagitis showed EGF-R staining of the surface epithelium. A computerised planimeter was used to determine the proportion of stained areas of squamous cells which were expressed as a percentage of the total area of squamous cells. The difference in the area of cells stained for EGF-R between normal and inflamed oesophageal mucosa (29.5% and 43.1% respectively) was significant (p less than 0.001). Images Figure 1 PMID:1582583

  3. Cutaneous adverse reactions specific to epidermal growth factor receptor inhibitors

    PubMed Central

    Lupu, I; Voiculescu, VM; Bacalbasa, N; Prie, BE; Cojocaru, I; Giurcaneanu, C

    2015-01-01

    Classical antineoplastic therapy is encumbered by extensively studied adverse reactions, most often of systemic nature. The emergence of new generations of anticancer treatments, including epidermal growth factor receptor inhibitors, besides improving the response to treatment and the survival rate, is accompanied by the occurrence of new specific side effects, incompletely studied. These side effects are most often cutaneous (hand foot syndrome, acneiform reactions), and in some cases are extremely severe, requiring dose reduction or drug discontinuation. The prevention of the cutaneous adverse effects and their treatment require a close collaboration between the oncologist and the dermatologist. The occurrence of some of these skin adverse effects may be a favorable prognostic factor for the response to the cancer treatment and the overall survival. Abbreviations: EGFR = epidermal growth factor receptors; EGFRI = epidermal growth factor receptors inhibitors PMID:26361513

  4. Epidermal growth factor receptor inhibitor therapy for recurrent respiratory papillomatosis

    PubMed Central

    Sidman, James D.

    2013-01-01

    The epidermal growth factor pathway has been implicated in various tumors, including human papillomavirus (HPV) lesions such as recurrent respiratory papillomatosis (RRP). Due to the presence of epidermal growth factor receptors in RRP, epidermal growth factor receptor (EGFR) inhibitors have been utilized as adjuvant therapy. This case series examines the response to EGFR inhibitors in RRP. Four patients with life-threatening RRP were treated with EGFR inhibitors. Operative frequency and anatomical Derkay scores were calculated prior to, and following EGFR inhibitor treatment via retrospective chart review. The anatomical Derkay score decreased for all four patients after initiation of EGFR inhibitor therapy. In one patient, the operative frequency increased after switching to an intravenous inhibitor after loss of control with an oral inhibitor. In the other patients there was a greater than 20% decrease in operative frequency in one and a more than doubling in the time between procedures in two.  This study suggests that EGFR inhibitors are a potential adjuvant therapy in RRP and deserve further study in a larger number of patients. PMID:24795806

  5. Coregulation of Epidermal Growth Factor Receptor/Human Epidermal Growth Factor Receptor 2 (HER2) Levels and Locations: Quantitative Analysis of HER2 Overexpression Effects

    SciTech Connect

    Hendriks, Bart S.; Opresko, Lee; Wiley, H. S.; Lauffenburger, Douglas A.

    2003-03-01

    Elevated expression of human epidermal growth factor receptor 2 (HER2) is know to alter cell signalilng and behavioral responses implicated in tumor progression. However, multiple diverse mechanisms may be involved in these overall effects, including signaling by HER2 itself, modulation of signalilng by epidermal growth factor receptor (EGFR) and modification of trafficking dynamics for both EGFR and HER2. Continued....

  6. Epidermal growth factor receptors in the canine antrum

    SciTech Connect

    Zimmerman, R.P.; Gates, T.S.; Boehmer, C.G.; Mantyh, P.W.

    1988-11-01

    In this study we localized receptor binding sites for /sup 125/I-human epidermal growth factor (hEGF) in the antrum of the adult canine stomach. High levels of specific /sup 125/I-hEGF binding sites were observed over the mucosa and muscularis mucosa, whereas specific binding sites were not detectable over the submucosa, external circular and longitudinal muscle or myenteric neurons. These results are in agreement with previous studies which indicated that EGF stimulates the proliferation of cultured epithelial cells and inhibits gastric acid secretion. This suggests that EGF may be a useful therapeutic agent in the healing of gastric ulcers.

  7. Upregulation of epidermal growth factor receptor 4 in oral leukoplakia

    PubMed Central

    Kobayashi, Hiroshi; Kumagai, Kenichi; Gotoh, Akito; Eguchi, Takanori; Yamada, Hiroyuki; Hamada, Yoshiki; Suzuki, Satsuki; Suzuki, Ryuji

    2013-01-01

    In the present study, we investigate the expression profile of the epidermal growth factor receptor family, which comprises EGFR/ErbB1, HER2/ErbB2, HER3/ErbB3 and HER4/ErbB4 in oral leukoplakia (LP). The expression of four epidermal growth factor receptor (EGFR) family genes and their ligands were measured in LP tissues from 14 patients and compared with levels in 10 patients with oral lichen planus (OLP) and normal oral mucosa (NOM) from 14 healthy donors by real-time polymerase chain reaction (PCR) and immunohistochemistry. Synchronous mRNA coexpression of ErbB1, ErbB2, ErbB3 and ErbB4 was detected in LP lesions. Out of the receptors, only ErbB4 mRNA and protein was more highly expressed in LP compared with NOM tissues. These were strongly expressed by epithelial keratinocytes in LP lesions, as shown by immunohistochemistry. Regarding the ligands, the mRNA of Neuregulin2 and 4 were more highly expressed in OLP compared with NOM tissues. Therefore, enhanced ErbB4 on the keratinocytes and synchronous modulation of EGFR family genes may contribute to the pathogenesis and carcinogenesis of LP. PMID:23492901

  8. Overexpression and activation of epidermal growth factor receptor in hemangioblastomas

    PubMed Central

    Chen, Gregory J.; Karajannis, Matthias A.; Newcomb, Elizabeth W.

    2010-01-01

    Hemangioblastomas frequently develop in patients with von Hippel-Lindau (VHL) disease, an autosomal dominant genetic disorder. The tumors are characterized by a dense network of blood capillaries, often in association with cysts. Although activation of receptor tyrosine kinase (RTK) signaling, including epidermal growth factor receptor (EGFR) has been implicated in the development of malignant brain tumors such as high-grade gliomas, little is known about the role of RTK signaling in hemangioblastomas. To address this issue, we examined hemangioblastoma tumor specimens using receptor tyrosine kinase (RTK) activation profiling and immunohistochemistry. Six human hemangioblastomas were analyzed with a phospho-RTK antibody array, revealing EGFR phosphorylation in all tumors. EGFR expression was confirmed by immunohistochemistry in all tumors analyzed and downstream effector pathway activation was demonstrated by positive staining for phospho-AKT. Our findings suggest that, in primary hemangioblastomas, RTK upregulation and signaling predominantly involves EGFR, providing an attractive molecular target for therapeutic intervention. PMID:20730556

  9. The ontogeny of epidermal growth factor receptors during mouse development

    SciTech Connect

    Adamson, E.D.; Meek, J.

    1984-05-01

    In an attempt to understand the role(s) of epidermal growth factor (EGF) in vivo during murine development, we have examined the /sup 125/I-EGF binding characteristics of EGF-receptors in membrane preparations of tissues from the 12th day of gestation to parturition. Using autoradiography, the earliest time that we could detect EGF-receptors was on trophoblast cells cultured for 3 days as blastocyst outgrowths. Trophoblast eventually forms a large portion of the placenta, where EGF-receptors have long been recognized. We measured the number and affinity of EGF-receptors on tissues dissected from conceptuses from the 12th day of gestation in order to identify a stage when tissues may be most sensitive to EGF. Whereas the number of EGF receptors increases during gestation for all tissues examined, the affinity of the receptors declines for carcass and placenta and remains relatively unchanged for brain and liver. This suggests that EGF may function differently throughout development. Our hypothesis is that EGF (or its embryonic equivalent) initially stimulates proliferation in embryonic cells and then stimulates differentiation as the tissues mature. In the adult, its main role could be to stimulate tissue repair after damage.

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

    SciTech Connect

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

    1987-04-01

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

  11. Epidermal growth factor receptor not equal to nerve growth factor.

    PubMed

    Williams, L R

    1989-01-01

    I am perplexed by the authors' complete lack of definition of neurotrophic factors. The agents Butcher and Woolf want to blame are neurite promoting factors, not neurotrophic factors. Treatment of Alzheimer's disease with NGF antagonists might instead exacerbate the death of both basal forebrain neurons and their cortical target neurons, accelerating the progress of dementia.

  12. Clinical experience with monoclonal antibodies to epidermal growth factor receptor.

    PubMed

    Calvo, Emiliano; Rowinsky, Eric K

    2005-03-01

    Recent knowledge about the intermediate steps and final consequences of ligand-dependent epidermal growth factor receptor (EGFR) activation has clearly supported the notion that EGFR plays a fundamental role in regulating the proliferation and survival of malignant neoplasms. Among the rationally designed target-based therapeutics that are being assessed, those targeting EGFR appear to be some of the most clinically relevant. The strategy of using monoclonal antibodies (mAbs) to block ligand binding to the extracellular domain of the EGFR has led to the development of therapeutics that robustly arrest malignant cell proliferation and, in some cases, induce profound tumor regression. The chimeric mAb against EGFR, cetuximab, has already been approved by regulatory agencies worldwide to treat patients with advanced colorectal cancer. Other mAbs against EGFR, particularly panitumumab (ABX-EGF), h-R3, and EMD72000, are in advanced stages of clinical development. PMID:15717942

  13. Patterns of epidermal growth factor receptor amplification in malignant gliomas.

    PubMed Central

    Sauter, G.; Maeda, T.; Waldman, F. M.; Davis, R. L.; Feuerstein, B. G.

    1996-01-01

    Amplification of the gene for epidermal growth factor receptor (EGFR) is a common finding in malignant gliomas. We found that 18 of 29 grade 3 and grade 4 gliomas had EGFR amplification when assayed using fluorescence in situ hybridization. The amplification pattern suggests that the amplicon is contained within double minute chromosomes in most cases. EGFR copy number can differ by 20-fold in amplified cells within a single case. Polysomy 7 occurs frequently in both EGFR-amplified and -unamplified cells. More than one-third of the cases had < or = 10 percent of cells with amplified EGFR, and it is likely that these cases would not have been identified by methods that do not examine DNA on a cell by cell basis. Images Figure 1 PMID:8644846

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

    SciTech Connect

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

    1990-05-01

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

  15. pH sensitivity of epidermal growth factor receptor complexes.

    PubMed

    Nunez, M; Mayo, K H; Starbuck, C; Lauffenburger, D

    1993-03-01

    The association/dissociation binding kinetics of 125I-labeled mouse epidermal growth factor (EGF) to receptors on human fibroblast cells in monolayer culture have been measured at 4 degrees C as a function of extracellular pH from pH 5-9. At pH 8, steady-state total binding is maximal. As pH is lowered to 6.5, total binding monotonically decreases dramatically. It changes further only slightly between pH 6.5 and 5 to about 20% of the maximum binding value. Scatchard binding plots at pH 7.5 and above show the commonly observed concave-upward, non-linear curve; as pH is lowered, this plot becomes much more linear, indicating that the "high affinity" bound receptor population is greatly diminished. Application of our ternary complex binding model [Mayo et al., J Biol Chem 264:17838-17844, 1989], which hypothesizes complexation of the EGF-bound receptor with a cell surface interaction molecule, indicates that pH may have some direct effects on ternary complex formation, but the major effect is on EGF-receptor dissociation. PMID:8501133

  16. Nanoscale Imaging of Epidermal Growth Factor Receptor Clustering

    PubMed Central

    Abulrob, Abedelnasser; Lu, Zhengfang; Baumann, Ewa; Vobornik, Dusan; Taylor, Rod; Stanimirovic, Danica; Johnston, Linda J.

    2010-01-01

    The development of some solid tumors is associated with overexpression of the epidermal growth factor receptor (EGFR) and often correlates with poor prognosis. Near field scanning optical microscopy, a technique with subdiffraction-limited optical resolution, was used to examine the influence of two inhibitors (the chimeric 225 antibody and tyrosine phosphorylation inhibitor AG1478) on the nanoscale clustering of EGFR in HeLa cells. The EGFR is organized in small clusters, average diameter of 150 nm, on the plasma membrane for both control and EGF-treated cells. The numbers of receptors in individual clusters vary from as few as one or two proteins to greater than 100. Both inhibitors yield an increased cluster density and an increase in the fraction of clusters with smaller diameters and fewer receptors. Exposure to AG1478 also decreases the fraction of EGFR that colocalizes with both rafts and caveolae. EGF stimulation results in a significant loss of the full-length EGFR from the plasma membrane with the concomitant appearance of low molecular mass proteolytic products. By contrast, AG1478 reduces the level of EGFR degradation. Changes in receptor clustering provide one mechanism for regulating EGFR signaling and are relevant to the design of strategies for therapeutic interventions based on modulating EGFR signaling. PMID:19959837

  17. Transcriptional down-regulation of epidermal growth factor receptors by nerve growth factor treatment of PC12 cells.

    PubMed

    Shibutani, M; Lazarovici, P; Johnson, A C; Katagiri, Y; Guroff, G

    1998-03-20

    Treatment of PC12 cells with nerve growth factor leads to a decrease in the number of epidermal growth factor receptors on the cell membrane. The mRNA for the epidermal growth factor receptor decreases in a comparable fashion. This decrease appears due to a decrease in the transcription of the epidermal growth factor receptor gene because first, there is no difference in the stability of the epidermal growth factor receptor mRNA, second, newly transcribed epidermal growth factor receptor mRNA is decreased in nerve growth factor-differentiated cells, and third, constructs containing the promoter region of the epidermal growth factor receptor gene are transcribed much less readily in nerve growth factor-differentiated cells than in untreated cells. The decreases in mRNA are not seen in the p140(trk)-deficient variant PC12nnr5 cells nor in cells containing either dominant-negative Ras or dominant-negative Src. Treatment with nerve growth factor also increases the cellular content of GCF2, a putative transcription factor inhibitory for the transcription of the epidermal growth factor receptor gene. The increase in GCF2, like the decrease in the epidermal growth factor receptor mRNA, is not seen in PC12nnr5 cells nor in cells expressing either dominant-negative Ras or dominant-negative Src. The results suggest that nerve growth factor-induced down-regulation of the epidermal growth factor receptor is under transcriptional control, is p140(trk)-, Ras-, and Src-dependent, and may involve transcriptional repression by GCF2.

  18. Epidermal growth factor receptor in adult human dorsal root ganglia.

    PubMed

    Huerta, J J; Diaz-Trelles, R; Naves, F J; Llamosas, M M; Del Valle, M E; Vega, J A

    1996-09-01

    Transforming growth factor-alpha (TGFalpha) enhances neuronal survival and neurite outgrowth in cultured dorsal root ganglia (DRG) sensory neurons. It binds a membrane protein, denominated epidermal growth factor receptor (EGFr). EGFr has been localized in developing and adult human DRG. However, it remains to be elucidated whether all DRG neurons express EGFr or whether differences exist among neuronal subtypes. This study was undertaken to investigate these topics in adult human DRG using immunoblotting, and combined immunohistochemistry and image analysis techniques. A mouse monoclonal antibody (clone F4) mapping within the intracytoplasmic domain of EGFr was used. Immunoblotting revealed two main proteins with estimated molecular masses of approximately/equal to 65 kDa and 170 kDa, and thus consistent with the full-length EGFr. Additional protein bands were also encountered. Light immunohistochemistry revealed specific immunoreactivity (IR) for EGFr-like proteins in most (86%) primary sensory neurons, the intensity of immunostaining being stronger in the small- and intermediate-sized ones. Furthermore, EGFr-like IR was also observed in the satellite glial cells of the ganglia as well as in the intraganglionic and dorsal root Schwann cells. Taken together, our findings demonstrate that EGFr, and other related proteins containing the epitope labeled with the antibody F4, are responsible for the EGFr IR reported in DRG. Furthermore, we demonstrated heterogeneity in the expression of EGFr-like IR in adult human primary sensory neurons, which suggests different responsiveness to their ligands.

  19. The epidermal growth factor receptor pathway in chronic kidney diseases.

    PubMed

    Harskamp, Laura R; Gansevoort, Ron T; van Goor, Harry; Meijer, Esther

    2016-08-01

    The epidermal growth factor receptor (EGFR) pathway has a critical role in renal development, tissue repair and electrolyte handling. Numerous studies have reported an association between dysregulation of this pathway and the initiation and progression of various chronic kidney diseases such as diabetic nephropathy, chronic allograft nephropathy and polycystic kidney disease through the promotion of renal cell proliferation, fibrosis and inflammation. In the oncological setting, compounds that target the EGFR pathway are already in clinical use or have been evaluated in clinical trials; in the renal setting, therapeutic interventions targeting this pathway by decreasing ligand availability with disintegrin and metalloproteinase inhibitors or with ligand-neutralizing antibodies, or by inhibiting receptor activation with tyrosine kinase inhibitors or monoclonal antibodies are only just starting to be explored in animal models of chronic kidney disease and in patients with autosomal dominant polycystic kidney disease. In this Review we focus on the role of the EGFR signalling pathway in the kidney under physiological conditions and during the pathophysiology of chronic kidney diseases and explore the clinical potential of interventions in this pathway to treat chronic renal diseases. PMID:27374915

  20. Epidermal Growth Factor Receptor in Prostate Cancer Derived Exosomes

    PubMed Central

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

    2016-01-01

    Exosomes proteins and microRNAs have gained much attention as diagnostic tools and biomarker potential in various malignancies including prostate cancer (PCa). However, the role of exosomes and membrane-associated receptors, particularly epidermal growth factor receptor (EGFR) as mediators of cell proliferation and invasion in PCa progression remains unexplored. EGFR is frequently overexpressed and has been associated with aggressive forms of PCa. While PCa cells and tissues express EGFR, it is unknown whether exosomes derived from PCa cells or PCa patient serum contains EGFR. The aim of this study was to detect and characterize EGFR in exosomes derived from PCa cells, LNCaP xenograft and PCa patient serum. Exosomes were isolated from conditioned media of different PCa cell lines; LNCaP xenograft serum as well as patient plasma/serum by differential centrifugation and ultracentrifugation on a sucrose density gradient. Exosomes were confirmed by electron microscopy, expression of exosomal markers and NanoSight™ analysis. EGFR expression was determined by western blot analysis and ELISA. This study demonstrates that exosomes may easily be derived from PCa cell lines, serum obtained from PCa xenograft bearing mice and clinical samples derived from PCa patients. Presence of exosomal EGFR in PCa patient exosomes may present a novel approach for measuring of the disease state. Our work will allow to build on this finding for future understanding of PCa exosomes and their potential role in PCa progression and as minimal invasive biomarkers for PCa. PMID:27152724

  1. Anti-Epidermal Growth Factor Receptor Gene Therapy for Glioblastoma

    PubMed Central

    Hicks, Martin J.; Chiuchiolo, Maria J.; Ballon, Douglas; Dyke, Jonathan P.; Aronowitz, Eric; Funato, Kosuke; Tabar, Viviane; Havlicek, David; Fan, Fan; Sondhi, Dolan; Kaminsky, Stephen M.; Crystal, Ronald G.

    2016-01-01

    Glioblastoma multiforme (GBM) is the most common and aggressive primary intracranial brain tumor in adults with a mean survival of 14 to 15 months. Aberrant activation of the epidermal growth factor receptor (EGFR) plays a significant role in GBM progression, with amplification or overexpression of EGFR in 60% of GBM tumors. To target EGFR expressed by GBM, we have developed a strategy to deliver the coding sequence for cetuximab, an anti-EGFR antibody, directly to the CNS using an adeno-associated virus serotype rh.10 gene transfer vector. The data demonstrates that single, local delivery of an anti-EGFR antibody by an AAVrh.10 vector coding for cetuximab (AAVrh.10Cetmab) reduces GBM tumor growth and increases survival in xenograft mouse models of a human GBM EGFR-expressing cell line and patient-derived GBM. AAVrh10.CetMab-treated mice displayed a reduction in cachexia, a significant decrease in tumor volume and a prolonged survival following therapy. Adeno-associated-directed delivery of a gene encoding a therapeutic anti-EGFR monoclonal antibody may be an effective strategy to treat GBM. PMID:27711187

  2. Oncogenic fingerprint of epidermal growth factor receptor pathway and emerging epidermal growth factor receptor blockade resistance in colorectal cancer

    PubMed Central

    Sobani, Zain A; Sawant, Ashwin; Jafri, Mikram; Correa, Amit Keith; Sahin, Ibrahim Halil

    2016-01-01

    Epidermal growth factor receptor (EGFR) has been an attractive target for treatment of epithelial cancers, including colorectal cancer (CRC). Evidence from clinical trials indicates that cetuximab and panitumumab (anti-EGFR monoclonal antibodies) have clinical activity in patients with metastatic CRC. The discovery of intrinsic EGFR blockade resistance in Kirsten RAS (KRAS)-mutant patients led to the restriction of anti-EGFR antibodies to KRAS wild-type patients by Food and Drug Administration and European Medicine Agency. Studies have since focused on the evaluation of biomarkers to identify appropriate patient populations that may benefit from EGFR blockade. Accumulating evidence suggests that patients with mutations in EGFR downstream signaling pathways including KRAS, BRAF, PIK3CA and PTEN could be intrinsically resistant to EGFR blockade. Recent whole genome studies also suggest that dynamic alterations in signaling pathways downstream of EGFR leads to distinct oncogenic signatures and subclones which might have some impact on emerging resistance in KRAS wild-type patients. While anti-EGFR monoclonal antibodies have a clear potential in the management of a subset of patients with metastatic CRC, further studies are warranted to uncover exact mechanisms related to acquired resistance to EGFR blockade. PMID:27777877

  3. Transcription-dependent epidermal growth factor receptor activation by hepatocyte growth factor.

    PubMed

    Reznik, Thomas E; Sang, Yingying; Ma, Yongxian; Abounader, Roger; Rosen, Eliot M; Xia, Shuli; Laterra, John

    2008-01-01

    The mechanisms and biological implications of coordinated receptor tyrosine kinase coactivation remain poorly appreciated. Epidermal growth factor receptor (EGFR) and c-Met are frequently coexpressed in cancers, including those associated with hepatocyte growth factor (HGF) overexpression, such as malignant astrocytoma. In a previous analysis of the HGF-induced transcriptome, we found that two EGFR agonists, transforming growth factor-alpha and heparin-binding epidermal growth factor-like growth factor (HB-EGF), are prominently up-regulated by HGF in human glioma cells. We now report that stimulating human glioblastoma cells with recombinant HGF induces biologically relevant EGFR activation. EGFR phosphorylation at Tyr(845) and Tyr(1068) increased 6 to 24 h after cell stimulation with HGF and temporally coincided with the induction of transforming growth factor-alpha (~5-fold) and HB-EGF (~23-fold) expression. Tyr(845) and Tyr(1068) phosphorylation, in response to HGF, was inhibited by cycloheximide and actinomycin D, consistent with a requirement for DNA transcription and RNA translation. Specifically, blocking HB-EGF binding to EGFR with the antagonist CRM197 inhibited HGF-induced EGFR phosphorylation by 60% to 80% and inhibited HGF-induced S-G(2)-M transition. CRM197 also inhibited HGF-induced anchorage-dependent cell proliferation but had no effect on HGF-mediated cytoprotection. These findings establish that EGFR can be activated with functional consequences by HGF as a result of EGFR ligand expression. This transcription-dependent cross-talk between the HGF receptor c-Met and EGFR expands our understanding of receptor tyrosine kinase signaling networks and may have considerable consequences for oncogenic mechanisms and cancer therapeutics.

  4. Expression of human tyrosine kinase-negative epidermal growth factor receptor amplifies signaling through endogenous murine epidermal growth factor receptor.

    PubMed

    Hack, N; Sue-A-Quan, A; Mills, G B; Skorecki, K L

    1993-12-15

    Recent findings have suggested that certain ligand-dependent responses to EGF may be propagated in a manner that is not dependent on the intrinsic tyrosine kinase activity of the epidermal growth factor receptor (EGF-R, Campos-Gonzalez, R., and Glenney, J. R., Jr. (1992) J. Biol. Chem. 267, 14535-14538) or, alternatively, that these responses may occur through the interaction of the human tyrosine kinase-deficient EGF-R with an as yet unidentified kinase (Selva, E., Raden, D. L., and Davis, R. J. (1993) J. Biol. Chem. 268, 2250-2254). These conclusions represent a significant departure from our current understanding of signal transduction by receptor tyrosine kinases. Therefore we examined the effect of expression of tyrosine kinase-negative human EGF receptor in murine NIH-3T3-2.2 cells on the EGF-dependent phosphorylation of mitogen-activated protein (MAP-2) kinase. In parental cells (NIH-3T3-2.2) that express low levels of endogenous murine EGF-R, there was no demonstrable EGF-dependent coupling to MAP-2 kinase. In NIH-3T3-2.2 cells transfected with tyrosine kinase-negative human EGF-R, there was unexpected EGF-dependent phosphorylation of MAP-2 kinase. Analysis of the tyrosine kinase-negative human EGF-R in these cells revealed significant tyrosine phosphorylation of the EGF-R. A low level of endogenous murine EGF-R present in these cells were also phosphorylated on tyrosine residues and displayed autokinase activity. Similar results were obtained using an unrelated cell line (B82L cells), in which EGF-dependent phosphorylation of MAP-2 kinase was previously attributed to signal propagation through a tyrosine kinase-negative human EGF-R (Campos-Gonzalez, R., and Glenney, J. R., Jr. (1992) J. Biol. Chem. 267, 14535-14538). Taken together, these results suggest that the tyrosine kinase-negative human EGF-R are able to amplify the response to activation of low levels of endogenous murine EGF-R, thus leading to EGF-dependent phosphorylation of MAP-2 kinase in cells

  5. Adverse Reaction to Cetuximab, an Epidermal Growth Factor Receptor Inhibitor.

    PubMed

    Štulhofer Buzina, Daška; Martinac, Ivana; Ledić Drvar, Daniela; Čeović, Romana; Bilić, Ivan; Marinović, Branka

    2016-04-01

    Dear Editor, Inhibition of the epidermal growth factor receptor (EGFR) is a new strategy in treatment of a variety of solid tumors, such as colorectal carcinoma, non-small cell lung cancer, squamous cell carcinoma of the head and neck, and pancreatic cancer (1). Cetuximab is a chimeric human-murine monoclonal antibody against EGFR. Cutaneous side effects are the most common adverse reactions occurring during epidermal growth factor receptor inhibitors (EGFRI) therapy. Papulopustular rash (acne like rash) develop with 80-86% patients receiving cetuximab, while xerosis, eczema, fissures, teleangiectasiae, hyperpigmentations, and nail and hair changes occur less frequently (2). The mechanism underlying these skin changes has not been established and understood. It seems EGFRI alter cell growth and differentiation, leading to impaired stratum corneum and cell apoptosis (3-5). An abdominoperineal resection of the rectal adenocarcinoma (Dukes C) was performed on a 43-year-old female patient. Following surgery, adjuvant chemo-radiotherapy was applied. After two years, the patient suffered a metastatic relapse. Abdominal lymphadenopathy was detected on multi-slice computer tomography (MSCT) images, with an increased value of the carcinoembryonic antigen (CEA) tumor marker (maximal value 57 ng/mL). Hematological and biochemical tests were within normal limits, so first-line chemotherapy with oxaliplatin and a 5-fluorouracil (FOLFOX4) protocol was introduced. A wild type of the KRAS gene was confirmed in tumor tissue (diagnostic prerequisite for the introduction of EGFRI) and cetuximab (250 mg per m2 of body surface) was added to the treatment protocol. The patient responded well to the treatment with confirmed partial regression of the tumor formations. Three months after the patient started using cetuximab, an anti-EGFR monoclonal antibody, the patient presented with a papulopustular eruption in the seborrhoeic areas (Figure 1) and eczematoid reactions on the extremities

  6. Epidermal growth factor receptor distribution in burn wounds. Implications for growth factor-mediated repair.

    PubMed Central

    Wenczak, B A; Lynch, J B; Nanney, L B

    1992-01-01

    Epidermal growth factor (EGF) along with several related peptide growth factors has been shown both in vivo and in vitro to accelerate events associated with epidermal wound repair. EGF and transforming growth factor alpha act by binding to a common EGF receptor tyrosine kinase thereby initiating a series of events which ultimately regulate cell proliferation. This study examined the immunohistochemical localization of EGF receptor (EGF-R) in burn wound margins, adjacent proliferating epithelium, and closely associated sweat ducts, sebaceous glands, and hair follicles. Tissue specimens removed during surgical debridement were obtained from full and partial thickness burn wounds in 32 patients with total body surface area burns ranging from 2 to 88%. In the early postburn period (days 2-4), prominent staining for EGF-R was found in undifferentiated, marginal keratinocytes, adjacent proliferating, hypertrophic epithelium, and both marginal and nonmarginal hair follicles, sweat ducts, and sebaceous glands. During the late postburn period (days 5-16), EGF-R was depleted along leading epithelial margins; however, immunoreactive EGF-R remained intensely positive in the hypertrophic epithelium and all skin appendages. Increased detection of immunoreactive EGF-R and the presence of [125I]EGF binding in the hypertrophic epithelium correlated positively with proliferating cell nuclear antigen distributions. Thus, the presence of EGF-R in the appropriate keratinocyte populations suggests a functional role for this receptor during wound repair. Dynamic modulation in EGF receptor distribution during the temporal sequence of repair provides further evidence that an EGF/transforming growth factor alpha/EGF-R-mediated pathway is activated during human wound repair. Images PMID:1361495

  7. Cell Surface Epidermal Growth Factor Receptors Increase Src and c-Cbl Activity and Receptor Ubiquitylation*

    PubMed Central

    Parks, Eileen E.; Ceresa, Brian P.

    2014-01-01

    There is an established role for the endocytic pathway in regulation of epidermal growth factor receptor (EGFR) signaling to downstream effectors. However, because ligand-mediated EGFR endocytosis utilizes multiple “moving parts,” dissecting the spatial versus temporal contributions has been challenging. Blocking all endocytic trafficking can have unintended effects on other receptors as well as give rise to compensatory mechanisms, both of which impact interpretation of EGFR signaling. To overcome these limitations, we used epidermal growth factor (EGF) conjugated to polystyrene beads (EGF beads). EGF beads simultaneously activate the EGFR while blocking its endocytosis and allow analysis of EGFR signaling from the plasma membrane. Human telomerase immortalized corneal epithelial (hTCEpi) cells were used to model normal epithelial cell biology. In hTCEpi cells, both cell surface and intracellular EGFRs exhibited dose-dependent increases in effector activity after 15 min of ligand stimulation, but only the serine phosphorylation of signal transducer and activator of transcription 3 (STAT3) was statistically significant when accounting for receptor phosphorylation. However, over time with physiological levels of receptor phosphorylation, cell surface receptors produced either enhanced or sustained mitogen-activated protein kinase kinase (MEK), Casitas B-lineage lymphoma (c-Cbl), and the pro-oncogene Src activity. These increases in effector communication by cell surface receptors resulted in an increase in EGFR ubiquitylation with sustained ligand incubation. Together, these data indicate that spatial regulation of EGFR signaling may be an important regulatory mechanism in receptor down-regulation. PMID:25074934

  8. Early signaling dynamics of the epidermal growth factor receptor

    PubMed Central

    Gajadhar, Aaron S.; Swenson, Eric J.; Rothenberg, Daniel A.; Curran, Timothy G.; White, Forest M.

    2016-01-01

    Despite extensive study of the EGF receptor (EGFR) signaling network, the immediate posttranslational changes that occur in response to growth factor stimulation remain poorly characterized; as a result, the biological mechanisms underlying signaling initiation remain obscured. To address this deficiency, we have used a mass spectrometry-based approach to measure system-wide phosphorylation changes throughout the network with 10-s resolution in the 80 s after stimulation in response to a range of eight growth factor concentrations. Significant changes were observed on proteins far downstream in the network as early as 10 s after stimulation, indicating a system capable of transmitting information quickly. Meanwhile, canonical members of the EGFR signaling network fall into clusters with distinct activation patterns. Src homology 2 domain containing transforming protein (Shc) and phosphoinositol 3-kinase (PI3K) phosphorylation levels increase rapidly, but equilibrate within 20 s, whereas proteins such as Grb2-associated binder-1 (Gab1) and SH2-containing tyrosine phosphatase (SHP2) show slower, sustained increases. Proximity ligation assays reveal that Shc and Gab1 phosphorylation patterns are representative of separate timescales for physical association with the receptor. Inhibition of phosphatases with vanadate reveals site-specific regulatory mechanisms and also uncovers primed activating components in the network, including Src family kinases, whose inhibition affects only a subset of proteins within the network. The results presented highlight the complexity of signaling initiation and provide a window into exploring mechanistic hypotheses about receptor tyrosine kinase (RTK) biology. PMID:26929352

  9. Early signaling dynamics of the epidermal growth factor receptor.

    PubMed

    Reddy, Raven J; Gajadhar, Aaron S; Swenson, Eric J; Rothenberg, Daniel A; Curran, Timothy G; White, Forest M

    2016-03-15

    Despite extensive study of the EGF receptor (EGFR) signaling network, the immediate posttranslational changes that occur in response to growth factor stimulation remain poorly characterized; as a result, the biological mechanisms underlying signaling initiation remain obscured. To address this deficiency, we have used a mass spectrometry-based approach to measure system-wide phosphorylation changes throughout the network with 10-s resolution in the 80 s after stimulation in response to a range of eight growth factor concentrations. Significant changes were observed on proteins far downstream in the network as early as 10 s after stimulation, indicating a system capable of transmitting information quickly. Meanwhile, canonical members of the EGFR signaling network fall into clusters with distinct activation patterns. Src homology 2 domain containing transforming protein (Shc) and phosphoinositol 3-kinase (PI3K) phosphorylation levels increase rapidly, but equilibrate within 20 s, whereas proteins such as Grb2-associated binder-1 (Gab1) and SH2-containing tyrosine phosphatase (SHP2) show slower, sustained increases. Proximity ligation assays reveal that Shc and Gab1 phosphorylation patterns are representative of separate timescales for physical association with the receptor. Inhibition of phosphatases with vanadate reveals site-specific regulatory mechanisms and also uncovers primed activating components in the network, including Src family kinases, whose inhibition affects only a subset of proteins within the network. The results presented highlight the complexity of signaling initiation and provide a window into exploring mechanistic hypotheses about receptor tyrosine kinase (RTK) biology. PMID:26929352

  10. Early signaling dynamics of the epidermal growth factor receptor.

    PubMed

    Reddy, Raven J; Gajadhar, Aaron S; Swenson, Eric J; Rothenberg, Daniel A; Curran, Timothy G; White, Forest M

    2016-03-15

    Despite extensive study of the EGF receptor (EGFR) signaling network, the immediate posttranslational changes that occur in response to growth factor stimulation remain poorly characterized; as a result, the biological mechanisms underlying signaling initiation remain obscured. To address this deficiency, we have used a mass spectrometry-based approach to measure system-wide phosphorylation changes throughout the network with 10-s resolution in the 80 s after stimulation in response to a range of eight growth factor concentrations. Significant changes were observed on proteins far downstream in the network as early as 10 s after stimulation, indicating a system capable of transmitting information quickly. Meanwhile, canonical members of the EGFR signaling network fall into clusters with distinct activation patterns. Src homology 2 domain containing transforming protein (Shc) and phosphoinositol 3-kinase (PI3K) phosphorylation levels increase rapidly, but equilibrate within 20 s, whereas proteins such as Grb2-associated binder-1 (Gab1) and SH2-containing tyrosine phosphatase (SHP2) show slower, sustained increases. Proximity ligation assays reveal that Shc and Gab1 phosphorylation patterns are representative of separate timescales for physical association with the receptor. Inhibition of phosphatases with vanadate reveals site-specific regulatory mechanisms and also uncovers primed activating components in the network, including Src family kinases, whose inhibition affects only a subset of proteins within the network. The results presented highlight the complexity of signaling initiation and provide a window into exploring mechanistic hypotheses about receptor tyrosine kinase (RTK) biology.

  11. Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors from the natural origin: a recent perspective.

    PubMed

    Patel, Harun M; Rane, Rajesh; Thapliyal, Neeta; Palkar, Mahesh; Shaikh, Mahamadhanif; Karpoormath, Rajshekhar

    2015-01-01

    Overexpression of epidermal growth factor receptor (EGFR) is seen in a number of human tumors like prostate, colon, breast and ovarian. Their expression is correlated with vascularity and often difficult to diagnose. Though a number of active inhibitors and anticancer drugs against EGFR-tyrosine kinase are known, increase in resistance together with many side effects designate the need for new and improved treatments. Natural products and their analoges have significant contribution in the cancer drug discovery and development process. Therefore in the current review we mainly discuss design, synthesis and structural activity relationship of epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors from the natural origin.

  12. Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors from the natural origin: a recent perspective.

    PubMed

    Patel, Harun M; Rane, Rajesh; Thapliyal, Neeta; Palkar, Mahesh; Shaikh, Mahamadhanif; Karpoormath, Rajshekhar

    2015-01-01

    Overexpression of epidermal growth factor receptor (EGFR) is seen in a number of human tumors like prostate, colon, breast and ovarian. Their expression is correlated with vascularity and often difficult to diagnose. Though a number of active inhibitors and anticancer drugs against EGFR-tyrosine kinase are known, increase in resistance together with many side effects designate the need for new and improved treatments. Natural products and their analoges have significant contribution in the cancer drug discovery and development process. Therefore in the current review we mainly discuss design, synthesis and structural activity relationship of epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors from the natural origin. PMID:25763933

  13. Progesterone receptor subunits are high-affinity substrates for phosphorylation by epidermal growth factor receptor.

    PubMed Central

    Ghosh-Dastidar, P; Coty, W A; Griest, R E; Woo, D D; Fox, C F

    1984-01-01

    Purified preparations of epidermal growth factor (EGF) receptor were used to test hen oviduct progesterone receptor subunits as substrates for phosphorylation catalyzed by EGF receptor. Both the 80-kilodalton (kDa) (A) and the 105-kDa (B) progesterone receptor subunits were phosphorylated in a reaction that required EGF and EGF receptor. No phosphorylation of progesterone receptor subunits was observed in the absence of EGF receptor, even when Ca2+ was substituted for Mg2+ and Mn2+. Phospho amino acid analysis revealed phosphorylation at tyrosine residues, with no phosphorylation detectable at serine or threonine residues. Two-dimensional maps of phosphopeptides generated from phosphorylated 80- or 105-kDa subunits by tryptic digestion revealed similar patterns, with resolution of two major, several minor, and a number of very minor phosphopeptides. The Km of progesterone receptor for phosphorylation by EGF-activated EGF receptor was 100 nM and the Vmax was 2.5 nmol/min per mg of EGF receptor protein at 0 degrees C. The stoichiometry of phosphorylation/hormone binding for progesterone receptor subunits was 0.31 at ice-bath temperature and approximately 1.0 at 22 degrees C. Images PMID:6200881

  14. Inverse regulation of human ERBB2 and epidermal growth factor receptors by tumor necrosis factor alpha.

    PubMed

    Kalthoff, H; Roeder, C; Gieseking, J; Humburg, I; Schmiegel, W

    1993-10-01

    Recombinant human tumor necrosis factor (TNF) alpha decreased the expression of ERBB2 mRNA by stimulating p55 TNF receptors of pancreatic tumor cells. This decrease contrasts with an increase in epidermal growth factor receptor (EGFR) mRNA. Both effects were selectively achieved by TNF-alpha or -beta, whereas interferon alpha or gamma or transforming growth factor beta showed no such effects. The inverse regulatory effects of TNF on ERBB2 and EGFR mRNA levels were evoked by different signaling pathways of p55 TNF receptors. The TNF-mediated ERBB2 mRNA decrease was followed by a reduction in protein. Four of five pancreatic tumor cell lines exhibited this down-regulation. This decrease of ERBB2 is a singular example of a modulation of this growth factor receptor by TNF. Overexpression of ERBB2 has been reported to cause resistance to TNF and other cytotoxic cytokines. In our study we show that the TNF-mediated down-regulation of ERBB2 in pancreatic tumor cells is accompanied by an increase in growth inhibition at low doses of TNF. The simultaneous alteration of the ERBB2/EGFR balance by TNF represents a striking model of cytokine receptor transregulation in the growth control of malignant pancreatic epithelial cells.

  15. Inverse regulation of human ERBB2 and epidermal growth factor receptors by tumor necrosis factor alpha.

    PubMed Central

    Kalthoff, H; Roeder, C; Gieseking, J; Humburg, I; Schmiegel, W

    1993-01-01

    Recombinant human tumor necrosis factor (TNF) alpha decreased the expression of ERBB2 mRNA by stimulating p55 TNF receptors of pancreatic tumor cells. This decrease contrasts with an increase in epidermal growth factor receptor (EGFR) mRNA. Both effects were selectively achieved by TNF-alpha or -beta, whereas interferon alpha or gamma or transforming growth factor beta showed no such effects. The inverse regulatory effects of TNF on ERBB2 and EGFR mRNA levels were evoked by different signaling pathways of p55 TNF receptors. The TNF-mediated ERBB2 mRNA decrease was followed by a reduction in protein. Four of five pancreatic tumor cell lines exhibited this down-regulation. This decrease of ERBB2 is a singular example of a modulation of this growth factor receptor by TNF. Overexpression of ERBB2 has been reported to cause resistance to TNF and other cytotoxic cytokines. In our study we show that the TNF-mediated down-regulation of ERBB2 in pancreatic tumor cells is accompanied by an increase in growth inhibition at low doses of TNF. The simultaneous alteration of the ERBB2/EGFR balance by TNF represents a striking model of cytokine receptor transregulation in the growth control of malignant pancreatic epithelial cells. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 PMID:8105469

  16. MECHANISMS OF ZN-INDUCED SIGNAL INITIATION THROUGH THE EPIDERMAL GROWTH FACTOR RECEPTOR (EGFR)

    EPA Science Inventory

    MECHANISMS OF Zn-INDUCED SIGNAL INITIATION THROUGH THE EPIDERMAL GROWTH FACTOR RECEPTOR (EGFR)
    James M. Samet*, Lee M. Graves? and Weidong Wu?. *Human Studies Division, NHEERL, ORD, Research Triangle Park, NC 27711, and ?Center for Environmental Medicine, University of North C...

  17. Activation of epidermal growth factor receptor by metal-ligand complexes decreases levels of extracellular amyloid beta peptide.

    PubMed

    Price, Katherine A; Filiz, Gulay; Caragounis, Aphrodite; Du, Tai; Laughton, Katrina M; Masters, Colin L; Sharples, Robyn A; Hill, Andrew F; Li, Qiao-Xin; Donnelly, Paul S; Barnham, Kevin J; Crouch, Peter J; White, Anthony R

    2008-01-01

    The epidermal growth factor receptor is a receptor tyrosine kinase expressed in a range of tissues and cell-types. Activation of the epidermal growth factor receptor by a number of ligands induces downstream signalling that modulates critical cell functions including growth, survival and differentiation. Abnormal epidermal growth factor receptor expression and activation is also involved in a number of cancers. In addition to its cognate ligands, the epidermal growth factor receptor can be activated by metals such as zinc (Zn) and copper (Cu). Due to the important role of these metals in a number of diseases including neurodegenerative disorders, therapeutic approaches are being developed based on the use of lipid permeable metal-complexing molecules. While these agents are showing promising results in animal models and clinical trials, little is known about the effects of metal-ligand complexes on cell signalling pathways. In this study, we investigated the effects of clioquinol (CQ)-metal complexes on activation of epidermal growth factor receptor. We show here that CQ-Cu complexes induced potent epidermal growth factor receptor phosphorylation resulting in downstream activation of extracellular signal-regulated kinase. Similar levels of epidermal growth factor receptor activation were observed with alternative lipid permeable metal-ligands including neocuproine and pyrrolidine dithiocarbamate. We found that CQ-Cu complexes induced a significant reduction in the level of extracellular Abeta1-40 in cell culture. Inhibition of epidermal growth factor receptor activation by PD153035 blocked extracellular signal-regulated kinase phosphorylation and restored Abeta1-40 levels. Activation of the epidermal growth factor receptor by CQ-Cu was mediated through up-regulation of src kinase activity by a cognate ligand-independent process involving membrane integrins. These findings provide the first evidence that metal-ligand complexes can activate the epidermal growth

  18. Quantitative in vivo immunohistochemistry of epidermal growth factor receptor using a receptor concentration imaging approach

    PubMed Central

    Samkoe, Kimberley S.; Tichauer, Kenneth M.; Gunn, Jason R.; Wells, Wendy A.; Hasan, Tayyaba; Pogue, Brian W.

    2014-01-01

    As receptor-targeted therapeutics become increasingly used in clinical oncology, the ability to quantify protein expression and pharmacokinetics in vivo is imperative to ensure successful individualized treatment plans. Current standards for receptor analysis are performed on extracted tissues. These measurements are static and often physiologically irrelevant, therefore, only a partial picture of available receptors for drug targeting in vivo is provided. Until recently, in vivo measurements were limited by the inability to separate delivery, binding, and retention effects but this can be circumvented by a dual-tracer approach for referencing the detected signal. We hypothesized that in vivo receptor concentration imaging (RCI) would be superior to ex vivo immunohistochemistry. Using multiple xenograft tumor models with varying epidermal growth factor receptor (EGFR) expression, we determined the EGFR concentration in each model using a novel targeted agent (anti-EGFR affibody-IRDye800CW conjugate) along with a simultaneously delivered reference agent (control affibody-IRDye680RD conjugate). The RCI-calculated in vivo receptor concentration was strongly correlated with ex vivo pathologist-scored immunohistochemistry and computer-quantified ex vivo immunofluorescence. In contrast, no correlation was observed with ex vivo Western blot or in vitro flow cytometry assays. Overall, our results argue that in vivo RCI provides a robust measure of receptor expression equivalent to ex vivo immuno-staining, with implications for use in non-invasive monitoring of therapy or therapeutic guidance during surgery. PMID:25344226

  19. Structure-Activity Relationship of Indole-Tethered Pyrimidine Derivatives that Concurrently Inhibit Epidermal Growth Factor Receptor and Other Angiokinases

    PubMed Central

    Song, Jiho; Yoo, Jakyung; Kwon, Ara; Kim, Doran; Nguyen, Hong Khanh; Lee, Bong-Yong; Suh, Wonhee; Min, Kyung Hoon

    2015-01-01

    Antiangiogenic agents have been widely investigated in combination with standard chemotherapy or targeted cancer agents for better management of advanced cancers. Therapeutic agents that concurrently inhibit epidermal growth factor receptor and other angiokinases could be useful alternatives to combination therapies for epidermal growth factor receptor-dependent cancers. Here, we report the synthesis of an indole derivative of pazopanib using a bioisosteric replacement strategy, which was designated MKP101. MKP101 inhibited not only the epidermal growth factor receptor with an IC50 value of 43 nM but also inhibited angiokinases as potently as pazopanib. In addition, MKP101 effectively inhibited vascular endothelial growth factor-induced endothelial proliferation, tube formation, migration of human umbilical vein endothelial cells and proliferation of HCC827, an epidermal growth factor receptor-addicted cancer cell line. A docking model of MKP101 and the kinase domain of the epidermal growth factor receptor was generated to predict its binding mode, and validated by synthesizing and evaluating MKP101 derivatives. Additionally, a study of structure-activity relationships of indolylamino or indolyloxy pyrimidine analogues derived from MKP101 demonstrated that selectivity for epidermal growth factor receptor and other angiokinases, especially vascular endothelial growth factor receptor 2 depends on the position of substituents on pyrimidine and the type of link between pyrimidine and the indole moiety. We believe that this study could provide a basis for developing angiokinase inhibitors having high affinity for the epidermal growth factor receptor, from the pyrimidine scaffold. PMID:26401847

  20. Engineered epidermal growth factor mutants with faster binding on-rates correlate with enhanced receptor activation

    PubMed Central

    Lahti, Jennifer L.; Lui, Bertrand H.; Beck, Stayce E.; Lee, Stephen S.; Ly, Daphne P.; Longaker, Michael T.; Yang, George P.; Cochran, Jennifer R.

    2011-01-01

    Receptor tyrosine kinases (RTKs) regulate critical cell signaling pathways, yet the properties of their cognate ligands that influence receptor activation are not fully understood. There is great interest in parsing these complex ligand-receptor relationships using engineered proteins with altered binding properties. Here we focus on the interaction between two engineered epidermal growth factor (EGF) mutants and the EGF receptor (EGFR), a model member of the RTK superfamily. We found that EGF mutants with faster kinetic on-rates stimulate increased EGFR activation compared to wild-type EGF. These findings support previous predictions that faster association rates correlate with enhanced receptor activity. PMID:21439278

  1. The F-BAR Protein PACSIN2 Regulates Epidermal Growth Factor Receptor Internalization

    PubMed Central

    de Kreuk, Bart-Jan; Anthony, Eloise C.; Geerts, Dirk; Hordijk, Peter L.

    2012-01-01

    Signaling via growth factor receptors, including the epidermal growth factor (EGF) receptor, is key to various cellular processes, such as proliferation, cell survival, and cell migration. In a variety of human diseases such as cancer, aberrant expression and activation of growth factor receptors can lead to disturbed signaling. Intracellular trafficking is crucial for proper signaling of growth factor receptors. As a result, the level of cell surface expression of growth factor receptors is an important determinant for the outcome of downstream signaling. BAR domain-containing proteins represent an important family of proteins that regulate membrane dynamics. In this study, we identify a novel role for the F-BAR protein PACSIN2 in the regulation of EGF receptor signaling. We show that internalized EGF as well as the (activated) EGF receptor translocated to PACSIN2-positive endosomes. Furthermore, loss of PACSIN2 increased plasma membrane expression of the EGF receptor in resting cells and increased EGF-induced phosphorylation of the EGF receptor. As a consequence, EGF-induced activation of Erk and Akt as well as cell proliferation were enhanced in PACSIN2-depleted cells. In conclusion, this study identifies a novel role for the F-BAR-domain protein PACSIN2 in regulating EGF receptor surface levels and EGF-induced downstream signaling. PMID:23129763

  2. Targeting the Human Epidermal Growth Factor Receptor 2 Pathway in Breast Cancer

    PubMed Central

    Damodaran, Senthilkumar; Olson, Erin M.

    2013-01-01

    The discovery of amplification of human epidermal growth factor receptor 2 (HER2), a member of the epidermal growth factor receptor family, was an important milestone in our understanding of the biology of breast cancers. This heralded the discovery of trastuzumab, a humanized monoclonal antibody targeting HER2. Trastuzumab is the foundation of treatment of HER2-positive breast cancers, demonstrating dramatic responses in patients with metastatic disease. Unfortunately, most tumors will inevitably develop resistance to trastuzumab, necessitating the need for alternate HER2-directed therapeutic approaches. Recent advances in our understanding of the interaction between HER2 and other members of the epidermal growth factor receptor family have led to identification of newer agents, resulting in the expansion of the clinical armamentarium of available agents for the treatment of HER2-positive tumors. In this article, we review the molecular biology of the ERbb receptor family, the use of HER2-targeted agents in early and advanced breast cancer, and the next-generation anti-HER2 agents that are currently in clinical evaluation. PMID:23299030

  3. Altered (/sup 125/I)epidermal growth factor binding and receptor distribution in psoriasis

    SciTech Connect

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

    1986-03-01

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

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

    PubMed

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

    2016-02-01

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

  5. Models for the activation pathway of epidermal growth factor receptor protein-tyrosine kinase

    SciTech Connect

    Campion, S.R.; Niyogi, S.K. )

    1991-03-15

    Activation of the epidermal growth factor (EGF) receptor's intrinsic protein-tyrosine kinase activity, which occurs upon formation of the receptor-ligand complex, is the critical regulatory event affecting the subsequent EGF-dependent cellular responses leading to DNA synthesis and cell proliferation. The molecular mechanism by which EGF-dependent activation of receptor kinase activity takes place is not clearly understood. In this study, the growth factor-dependent activation of the EGF receptor tyrosine kinase was examined in vitro using detergent-solubilized, partially purified GEF receptors from A5431 human epidermoid carcinoma cells. Evaluation of the cooperativity observed in the EGF-dependent activation of soluble receptor tyrosine kinase would suggest a mechanism requiring the binding of the EGF peptide to both ligand binding sites on a receptor dimer to induce full receptor kinase activity. Equations describing potential cooperative kinase activation pathways have been examined. The theoretical system which best simulates the allosteric regulation observed in the experimental kinase activation data is that describing multiple essential activation. In addition, studies using mutant analogs of the EGF peptide ligand appear to confirm the requirement for an essential conformational change in the receptor-ligand complex to activate the receptor kinase activity. Several mutant growth factor analogues are able to occupy the ligand binding sites on the receptor without inducing the fully active receptor conformation.

  6. Inhibited growth of colon cancer carcinomatosis by antibodies to vascular endothelial and epidermal growth factor receptors

    PubMed Central

    Shaheen, R M; Ahmad, S A; Liu, W; Reinmuth, N; Jung, Y D; Tseng, W W; Drazan, K E; Bucana, C D; Hicklin, D J; Ellis, L M

    2001-01-01

    Vascular endothelial growth factor (VEGF) and epidermal growth factor (EGF) regulate colon cancer growth and metastasis. Previous studies utilizing antibodies against the VEGF receptor (DC101) or EGF receptor (C225) have demonstrated independently that these agents can inhibit tumour growth and induce apoptosis in colon cancer in in vivo and in vitro systems. We hypothesized that simultaneous blockade of the VEGF and EGF receptors would enhance the therapy of colon cancer in a mouse model of peritoneal carcinomatosis. Nude mice were given intraperitoneal injection of KM12L4 human colon cancer cells to generate peritoneal metastases. Mice were then randomized into one of four treatment groups: control, anti-VEGFR (DC101), anti-EGFR (C225), or DC101 and C225. Relative to the control group, treatment with DC101 or with DC101+C225 decreased tumour vascularity, growth, proliferation, formation of ascites and increased apoptosis of both tumour cells and endothelial cells. Although C225 therapy did not change any of the above parameters, C225 combined with DC101 led to a significant decrease in tumour vascularity and increases in tumour cell and endothelial cell apoptosis (vs the DC101 group). These findings suggest that DC101 inhibits angiogenesis, endothelial cell survival, and VEGF-mediated ascites formation in a murine model of colon cancer carcinomatosis. The addition of C225 to DC101 appears to lead to a further decrease in angiogenesis and ascites formation. Combination anti-VEGF and anti-EGFR therapy may represent a novel therapeutic strategy for the management of colon peritoneal carcinomatosis. © 2001 Cancer Research Campaign http://www.bjcancer.com PMID:11506500

  7. Expression and localization of epidermal growth factor, transforming growth factor-α and epidermal growth factor receptor in the canine testis

    PubMed Central

    TAMADA, Hiromichi; TAKEMOTO, Kohei; TOMINAGA, Masato; KAWATE, Noritoshi; TAKAHASHI, Masahiro; HATOYA, Shingo; MATSUYAMA, Satoshi; INABA, Toshio; SAWADA, Tsutomu

    2015-01-01

    Gene expression of epidermal growth factor (EGF), transforming growth factor-α (TGF-α) and EGF receptor (EGF-R) and the localization of the corresponding proteins in the canine testis were studied. Levels of mRNA expressions were determined by semiquantitative reverse transcription polymerase chain reaction in the testes of the peripubertal (4–6 months), young adult (3–4 years), advanced adult (7–8 years) and senescent (11–16 years) groups. The EGF-R mRNA level in the testes of the peripubertal group was significantly higher than those in the other groups, whereas there was no difference in EGF and TGF-α mRNA levels among groups. Immunohistochemical stainings for EGF, TGF-α and EGF-R in the testis revealed that immunoreactivity in the seminiferous epithelium and Sertoli cell was weak and nonspecific for the stage of spermatogenesis, and distinct staining was found in Leydig cells. These results suggest that the EGF family of growth factors may be involved in testicular maturation and function in the dog. PMID:26498203

  8. Molecular cloning and expression of an additional epidermal growth factor receptor-related gene.

    PubMed Central

    Plowman, G D; Whitney, G S; Neubauer, M G; Green, J M; McDonald, V L; Todaro, G J; Shoyab, M

    1990-01-01

    Epidermal growth factor (EGF), transforming growth factor alpha (TGF-alpha), and amphiregulin are structurally and functionally related growth regulatory proteins. These secreted polypeptides all bind to the 170-kDa cell-surface EGF receptor, activating its intrinsic kinase activity. However, amphiregulin exhibits different activities than EGF and TGF-alpha in a number of biological assays. Amphiregulin only partially competes with EGF for binding EGF receptor, and amphiregulin does not induce anchorage-independent growth of normal rat kidney cells (NRK) in the presence of TGF-beta. Amphiregulin also appears to abrogate the stimulatory effect of TGF-alpha on the growth of several aggressive epithelial carcinomas that overexpress EGF receptor. These findings suggest that amphiregulin may interact with a separate receptor in certain cell types. Here we report the cloning of another member of the human EGF receptor (HER) family of receptor tyrosine kinases, which we have named "HER3/ERRB3." The cDNA was isolated from a human carcinoma cell line, and its 6-kilobase transcript was identified in various human tissues. We have generated peptide-specific antisera that recognizes the 160-kDa HER3 protein when transiently expressed in COS cells. These reagents will allow us to determine whether HER3 binds amphiregulin or other growth regulatory proteins and what role HER3 protein plays in the regulation of cell growth. Images PMID:2164210

  9. Ectodomain of Coxsackievirus and Adenovirus Receptor Genetically Fused to Epidermal Growth Factor Mediates Adenovirus Targeting to Epidermal Growth Factor Receptor-Positive Cells

    PubMed Central

    Dmitriev, Igor; Kashentseva, Elena; Rogers, Buck E.; Krasnykh, Victor; Curiel, David T.

    2000-01-01

    Human adenovirus (Ad) is extensively used for a variety of gene therapy applications. However, the utility of Ad vectors is limited due to the low efficiency of Ad-mediated gene transfer to target cells expressing marginal levels of the Ad fiber receptor. Therefore, the present generation of Ad vectors could potentially be improved by modification of Ad tropism to target the virus to specific organs and tissues. The fact that coxsackievirus and adenovirus receptor (CAR) does not play any role in virus internalization, but functions merely as the virus attachment site, suggests that the extracellular part of CAR might be utilized to block the receptor recognition site on the Ad fiber knob domain. We proposed to design bispecific fusion proteins formed by a recombinant soluble form of truncated CAR (sCAR) and a targeting ligand. In this study, we derived sCAR genetically fused with human epidermal growth factor (EGF) and investigated its ability to target Ad infection to the EGF receptor (EGFR) overexpressed on cancer cell lines. We have demonstrated that sCAR-EGF protein is capable of binding to Ad virions and directing them to EGFR, thereby achieving targeted delivery of reporter gene. These results show that sCAR-EGF protein possesses the ability to effectively retarget Ad via a non-CAR pathway, with enhancement of gene transfer efficiency. PMID:10888627

  10. Evidence that the epidermal growth factor receptor on host cells confers reovirus infection efficiency.

    PubMed

    Strong, J E; Tang, D; Lee, P W

    1993-11-01

    Reovirus binds to multiple sialoglycoproteins on the host cell surface. In an attempt to probe additional specific determinants that dictate host cell susceptibility to reovirus infection, we found that two mouse cell lines (NR6 and B82) previously shown to express no endogenous epidermal growth factor (EGF) receptors were relatively resistant to reovirus infection, whereas the same cell lines transfected with the gene encoding the EGF receptor manifested significantly higher susceptibility as determined by induction of cytopathic effects, viral protein synthesis, and plaque titration. This enhancement of infection efficiency requires a functional EGF receptor since it was not observed in cells expressing a mutated (kinase-inactive) EGF receptor. The observed difference in infection efficiency is not due to differences in virus binding or internalization. These studies suggest that the reovirus infection process is closely coupled to the EGF receptor-mediated cell signal transduction pathway.

  11. An integrated model of epidermal growth factor receptor trafficking and signal transduction.

    PubMed

    Resat, Haluk; Ewald, Jonathan A; Dixon, David A; Wiley, H Steven

    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 approximately 13,000 reactions/events that occur over a broad spatio-temporal range. By using a realistic multicompartment 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 physiochemical 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-alpha). Our simulations predict that when EGFR is activated with TGF-alpha, receptor activation is biased toward the cell surface whereas EGF produces a signaling bias toward the endosomal compartment. Experiments confirm these predictions from our model and simulations. Our model accurately predicts the kinetics and extent of receptor downregulation induced by either EGF or TGF-alpha. 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. PMID:12885624

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

    SciTech Connect

    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.

  13. Expression of neu protein, epidermal growth factor receptor, and transforming growth factor alpha in breast cancer. Correlation with clinicopathologic parameters.

    PubMed Central

    Lundy, J.; Schuss, A.; Stanick, D.; McCormack, E. S.; Kramer, S.; Sorvillo, J. M.

    1991-01-01

    The major objectives of this study were twofold: to determine 1) if growth factors or growth factor receptors were expressed similarly or differently in a clinically well-characterized group of breast cancer patients and 2) if these phenotypic characteristics were associated with any of the commonly used prognostic parameters. Formalin-fixed paraffin-embedded tumor tissue from 51 node-positive breast cancer patients were analyzed for the expression of neu, epidermal growth factor-receptor (EGF-R), and transforming growth factor alpha (TGF alpha) using immunoperoxidase staining. Positive membranous staining for neu was observed in 15 (29%) tumors. Over-expression of neu was observed in high-grade, estrogen-receptor-negative tumors (P less than 0.05). Epidermal growth factor receptor was expressed in 22 (43%) of the tumors analyzed and found to a greater degree in estrogen-receptor-negative and high-grade tumors (P less than 0.025). A significant correlation between neu and EGF-R expression was also noted. Tumors expressing membranous staining of neu had a greater than 70% chance of expressing EGF-R (P less than 0.01). Expression of TGF alpha was found in 68% of tumors and TGF alpha was detected in grade 1 and 2 tumor to a greater degree than EGF-R. The authors conclude that assaying tumors for these antigens may give additional phenotypic characteristics that can give further insight into the biology of breast cancer. Images Figure 1 Figure 2 Figure 3 PMID:1711294

  14. Epidermal growth factor receptor in breast cancer: storage conditions affecting measurement, and relationship to steroid receptors.

    PubMed

    McLeay, W R; Horsfall, D J; Seshadri, R; Morrison, D A; Saccone, G T

    1992-01-01

    This study investigates the effect of freezing and storage of tissue and subcellular fractions on the measurement of epidermal growth factor receptors (EGF-r); compares competition binding and single saturating dose assays (SSD) for quantitating EGF-r levels; investigates several tissues as potential quality control; and examines the relationship between EGF-r and hormone receptor expression in human breast cancers. Mouse and calf uterine cell membranes were preferred sources of quality control tissue with similar levels of high affinity EGF-r to human breast cancer tissue (less than 150-200 fmol/mg membrane protein). Studies using pooled mouse uterine tissues indicated a loss of 40% in EGF-r activity following a single-20 degrees C freeze/thaw cycle, while a breast cancer tissue showed a 75% loss, independent of storage temperature (liquid nitrogen, -70 degrees C, -20 degrees C). A single freeze/thaw cycle of mouse uterine broken cell pellets (nuclei plus membrane fraction) again indicated a loss of EGF-r irrespective of storage temperature (43% loss at -70 degrees C, 52% loss at -20 degrees C). In most cases irrespective of the tissue type or tissue fraction being stored, the length of storage had little impact on the extent of the loss in activity. A second freeze/thaw cycle of intact tissue, or freezing of broken cell pellets from a previously-frozen tissue, led to a further major or total loss of the remaining EGF-r. Overall these results are commensurate with the published effects of freezing and storage on estrogen receptor measurement. In addition, our studies suggest that the most suitable procedure for assaying frozen breast cancer specimens for EGF-r levels in conjunction with steroid receptor quantitation is to prepare and assay both cytosol and membrane fractions for their respective receptor content without further storage. A concordance of 86% was found in 44 breast cancers assayed for EGF-4 by saturation analysis and SSD. Statistically significant

  15. Redox regulation of epidermal growth factor receptor signaling through cysteine oxidation.

    PubMed

    Truong, Thu H; Carroll, Kate S

    2012-12-18

    Epidermal growth factor receptor (EGFR) exemplifies the family of receptor tyrosine kinases that mediate numerous cellular processes, including growth, proliferation, and differentiation. Moreover, gene amplification and EGFR mutations have been identified in a number of human malignancies, making this receptor an important target for the development of anticancer drugs. In addition to ligand-dependent activation and concomitant tyrosine phosphorylation, EGFR stimulation results in the localized generation of H(2)O(2) by NADPH-dependent oxidases. In turn, H(2)O(2) functions as a secondary messenger to regulate intracellular signaling cascades, largely through the modification of specific cysteine residues within redox-sensitive protein targets, including Cys797 in the EGFR active site. In this review, we highlight recent advances in our understanding of the mechanisms that underlie redox regulation of EGFR signaling and how these discoveries may form the basis for the development of new therapeutic strategies for targeting this and other H(2)O(2)-modulated pathways.

  16. Impact of epidermal growth factor receptor and transforming growth factor-α on hepatitis C virus-induced hepatocarcinogenesis.

    PubMed

    Badawy, Afkar Abdel-Ghany; El-Hindawi, Ali; Hammam, Olfat; Moussa, Mona; Gabal, Samia; Said, Noha

    2015-10-01

    Epidermal growth factor receptor system plays a central hepato-protective and pro-regenerative role in liver. Transforming growth factor-α (TGF-α) is an important autocrine growth regulator of hepatocytes that plays a role in development of hepatocellular carcinoma (HCC) among patients with chronic hepatitis C (CHC). This study was done on 40 core liver biopsies from patients with CHC, 20 liver specimens from HCC cases on top of CHC as well as five normal controls. All were immunohistochemically stained with epidermal growth factor receptor (EGFR) and TGF-α antibodies. Some selected HCC cases were submitted for FISH technique to detect EGFR gene alteration. By immunohistochemistry EGFR and TGF-α were overexpressed in HCC and cirrhotic cases compared to CHC cases without cirrhosis. Also, their expression was stronger in CHC cases with higher grades of activity and stages of fibrosis compared to lower ones. FISH positive results for EGFR were detected in 33.3% of the examined HCC cases. EGFR and TGF-α can be used as predictive markers for activity, fibrosis, and carcinogenesis in CHC patients. Overexpression of EGFR in HCC patients can be promising in selecting those who can get benefit from anti-EGFR target therapy. PMID:26279457

  17. Nanostructured materials detect epidermal growth factor receptor, neuron specific enolase and carcinoembryonic antigen

    NASA Astrophysics Data System (ADS)

    Stefan-van Staden, Raluca-Ioana; Comnea-Stancu, Ionela Raluca; Surdu-Bob, Carmen Cristina; Badulescu, Marius

    2015-09-01

    New nanostructured materials based on thin films of Cu and Ni deposited on textile material (veil), as well as gold nanostructured microspheres were used for the design of new stochastic sensors. The stochastic sensors were able to detect simultaneously a panel of biomarkers comprising epidermal growth factor receptor, neuron specific enolase, and carcinoembryonic antigen from whole blood samples with high reliabilities - recovery tests higher than 97.00%, with a RSD (%) lower than 0.1%. The stochastic sensors had shown high sensitivities and low determination levels for the detection of the proposed panel of biomarkers making early detection of lung cancer possible by fast screening of whole blood.

  18. Targeting epidermal growth factor receptor for head and neck squamous cell carcinoma: still lost in translation?

    PubMed Central

    Chapman, Christopher H.; Saba, Nabil F.

    2016-01-01

    The epidermal growth factor receptor (EGFR) is preferentially expressed in head and neck squamous cell carcinoma (HNSCC), and is a promising therapeutic target. Yet other than cetuximab, no agent targeting EGFR has been approved for this disease, and none has shown benefit over the standard of care. Several randomized trials of antibody and small molecule agents have found no new indication for these agents, despite their initial promise. In this review, we examine the major clinical evidence and discuss potential future developments of translational science in this area, including use of these agents in risk-stratified subgroups, inhibition of downstream/parallel targets, and combination with immunotherapy. PMID:27004227

  19. A novel endothelial cell surface receptor tyrosine kinase with extracellular epidermal growth factor homology domains.

    PubMed Central

    Partanen, J; Armstrong, E; Mäkelä, T P; Korhonen, J; Sandberg, M; Renkonen, R; Knuutila, S; Huebner, K; Alitalo, K

    1992-01-01

    Endothelial cell surfaces play key roles in several important physiological and pathological processes such as blood clotting, angiogenic responses, and inflammation. Here we describe the cloning and characterization of tie, a novel type of human endothelial cell surface receptor tyrosine kinase. The extracellular domain of the predicted tie protein product has an exceptional multidomain structure consisting of a cluster of three epidermal growth factor homology motifs embedded between two immunoglobulinlike loops, which are followed by three fibronectin type III repeats next to the transmembrane region. Additionally, a cDNA form lacking the first of the three epidermal growth factor homology domains was isolated, suggesting that alternative splicing creates different tie-type receptors. Cells transfected with tie cDNA expression vector produce glycosylated polypeptides of 117 kDa which are reactive to antisera raised against the tie carboxy terminus. The tie gene was located in chromosomal region 1p33 to 1p34. Expression of the tie gene appeared to be restricted in some cell lines; large amounts of tie mRNA were detected in endothelial cell lines and in some myeloid leukemia cell lines with erythroid and megakaryoblastoid characteristics. In addition, mRNA in situ studies further indicated the endothelial expression of the tie gene. The tie receptor tyrosine kinase may have evolved for multiple protein-protein interactions, possibly including cell adhesion to the vascular endothelium. Images PMID:1312667

  20. Studying the Stoichiometry of Epidermal Growth Factor Receptor in Intact Cells using Correlative Microscopy.

    PubMed

    Peckys, Diana B; de Jonge, Niels

    2015-09-11

    This protocol describes the labeling of epidermal growth factor receptor (EGFR) on COS7 fibroblast cells, and subsequent correlative fluorescence microscopy and environmental scanning electron microscopy (ESEM) of whole cells in hydrated state. Fluorescent quantum dots (QDs) were coupled to EGFR via a two-step labeling protocol, providing an efficient and specific protein labeling, while avoiding label-induced clustering of the receptor. Fluorescence microscopy provided overview images of the cellular locations of the EGFR. The scanning transmission electron microscopy (STEM) detector was used to detect the QD labels with nanoscale resolution. The resulting correlative images provide data of the cellular EGFR distribution, and the stoichiometry at the single molecular level in the natural context of the hydrated intact cell. ESEM-STEM images revealed the receptor to be present as monomer, as homodimer, and in small clusters. Labeling with two different QDs, i.e., one emitting at 655 nm and at 800 revealed similar characteristic results.

  1. Studying the Stoichiometry of Epidermal Growth Factor Receptor in Intact Cells using Correlative Microscopy

    PubMed Central

    Peckys, Diana B.; de Jonge, Niels

    2015-01-01

    This protocol describes the labeling of epidermal growth factor receptor (EGFR) on COS7 fibroblast cells, and subsequent correlative fluorescence microscopy and environmental scanning electron microscopy (ESEM) of whole cells in hydrated state. Fluorescent quantum dots (QDs) were coupled to EGFR via a two-step labeling protocol, providing an efficient and specific protein labeling, while avoiding label-induced clustering of the receptor. Fluorescence microscopy provided overview images of the cellular locations of the EGFR. The scanning transmission electron microscopy (STEM) detector was used to detect the QD labels with nanoscale resolution. The resulting correlative images provide data of the cellular EGFR distribution, and the stoichiometry at the single molecular level in the natural context of the hydrated intact cell. ESEM-STEM images revealed the receptor to be present as monomer, as homodimer, and in small clusters. Labeling with two different QDs, i.e., one emitting at 655 nm and at 800 revealed similar characteristic results. PMID:26383083

  2. [Epidermal growth factor receptor (EGFR): therapeutic target in the treatment of lung adenocarcinoma].

    PubMed

    Schwab, Richárd; Peták, István; Pintér, Ferenc; Szabó, Edit; Kánya, Melinda; Tamási, Anna; Várkondi, Edit; Almási, Andrea; Szokolóczi, Orsolya; Pápay, Judit; Moldvay, Judit; Kéri, György; Kopper, László

    2005-11-13

    Revolution in biotechnology made possible to identify those gene errors, which via their encoded proteins (mostly kinase enzymes) are key players in tumor development, growth and progression, and could be considered as molecular targets in tumor diagnosis and therapy. Activity of EGFR (epidermal growth factor receptor), an outstanding representative of the regulatory cell surface receptors, can be inhibited by drugs proved for clinical use. In the past year many groups observed that those lung adenocarcinoma cells, which contain activating mutation in the tyrosine kinase domain of EGFR show remarkable sensitivity to anti-EGFR compounds. The basis of the effective therapy is the identification of the mutations. The clinical advantage of EGFR is an example from the coming age of tumor chemotherapy, when the presence of molecular targets will guide the therapeutic choice.

  3. ErbB2 resembles an autoinhibited invertebrate epidermal growth factor receptor

    SciTech Connect

    Alvarado, Diego; Klein, Daryl E.; Lemmon, Mark A.

    2009-09-25

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

  4. Epidermal growth factor binding and receptor distribution in the mouse reproductive tract during development

    SciTech Connect

    Bossert, N.L.; Nelson, K.G.; Ross, K.A.; Takahashi, T.; McLachlan, J.A. )

    1990-11-01

    The ontogeny of the epidermal growth factor (EGF) receptor in the different cell types in the neonatal and immature mouse uterus and vagina was examined. Immunohistochemical examination of prenatal and neonatal reproductive tracts with a polyclonal antibody to the EGF receptor shows immunoreactive EGF receptors as early as Day 13 of gestation. Autoradiographic analysis of tissue sections at 3 to 17 days of age (the day of birth is Day 1) demonstrates that both uterine and vaginal epithelial and stromal cells are capable of binding 125I-labeled EGF. Both the 125I-labeled EGF autoradiography and immunohistochemistry in whole tissue show higher EGF receptor levels in the uterine epithelium than the uterine stroma. The presence of EGF receptors was also confirmed by affinity labeling and Scatchard analysis of isolated uterine cell types at 7 and/or 17 days of age. However, in contrast to the autoradiography and immunohistochemistry data of intact tissue, the affinity labeling and Scatchard data of isolated cells indicate that the uterine stroma contains higher levels of EGF receptor than that of the uterine epithelium. The reason for this discrepancy between the different techniques is, as yet, unknown. Regardless of the differences in the actual numbers of EGF receptors obtained, our data demonstrate that the developing mouse reproductive tract contains immunoreactive EGF receptors that are capable of binding 125I-labeled EGF.

  5. Arsenite and insulin exhibit opposing effects on epidermal growth factor receptor and keratinocyte proliferative potential

    SciTech Connect

    Patterson, Timothy J.; Rice, Robert H. . E-mail: rhrice@ucdavis.edu

    2007-05-15

    Previous work has suggested that arsenic exposure contributes to skin carcinogenesis by preserving the proliferative potential of human epidermal keratinocytes, thereby slowing the exit of putative target stem cells into the differentiation pathway. To find a molecular basis for this action, present work has explored the influence of arsenite on keratinocyte responses to epidermal growth factor (EGF). The ability of cultured keratinocytes to found colonies upon passaging several days after confluence was preserved by arsenite and EGF in an additive fashion, but neither was effective when the receptor tyrosine kinase activity was inhibited. Arsenite prevented the loss of EGF receptor protein and phosphorylation of tyrosine 1173, preserving its capability to signal. The level of nuclear {beta}-catenin was higher in cells treated with arsenite and EGF in parallel to elevated colony forming ability, and expression of a dominant negative {beta}-catenin suppressed the increase in both colony forming ability and yield of putative stem cells induced by arsenite and EGF. As judged by expression of three genes regulated by {beta}-catenin, this transcription factor had substantially higher activity in the arsenite/EGF-treated cells. Trivalent antimony exhibited the same effects as arsenite. A novel finding is that insulin in the medium induced the loss of EGF receptor protein, which was largely prevented by arsenite exposure.

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

    PubMed

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

    2016-02-01

    Skin toxicity is a frequent complication of anti-epidermal growth factor receptor therapy, which can be an obstacle in maintaining the dose intensity and may negatively impact on the clinical outcome of cancer patients. Skin lesions depend on the disruption of the keratinocyte development pathways and no treatment is clearly effective in resolving the cutaneous alterations frequently found during anti-epidermal growth factor receptor therapy. Among systemic treatments, oral tetracycline proved to be useful in preventing skin manifestations. We describe the case of a patient affected by metastatic colorectal cancer, for whom a combination of chemotherapy and cetuximab was used as second-line treatment. The patient developed a symptomatic papulopustular skin rash that disappeared completely after a twice-daily application of a hydrating and moisturizing cream, mainly consisting of a mixture of paraffin, silicone compounds, and macrogol. The marked cutaneous amelioration allowed the patient to continue cetuximab without any further symptoms and was associated with a partial radiological response. PMID:26469836

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

    SciTech Connect

    Harari, Paul M.

    2007-10-01

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

  8. Differential phosphorylation of the progesterone receptor by insulin, epidermal growth factor, and platelet-derived growth factor receptor tyrosine protein kinases.

    PubMed

    Woo, D D; Fay, S P; Griest, R; Coty, W; Goldfine, I; Fox, C F

    1986-01-01

    Purified preparations of insulin, epidermal growth factor (EGF), and platelet-derived growth factor (PDGF) receptors were compared for their abilities to phosphorylate purified hen oviduct progesterone receptors. The specific activities of all three peptide hormone-induced receptor kinases were first defined using a synthetic tridecapeptide tyrosine protein kinase substrate. Next, equivalent ligand-activated activities of the three receptor kinases were tested for their abilities to phosphorylate hen oviduct progesterone receptor. Both the insulin and EGF receptors phosphorylated progesterone receptor at high affinity, exclusively at tyrosine residues and with maximal stoichiometries that were near unity. In contrast, the PDGF receptor did not recognize progesterone receptor as a substrate. Insulin decreased the Km of the insulin receptor for progesterone receptor subunits as substrates, but had no significant effect on Vmax values. On the other hand, EGF increased the Vmax of the EGF receptor for progesterone receptor subunits as substrates. Phosphorylation of progesterone receptor by the insulin and EGF receptor kinases differed in two additional ways. 1) EGF-activated receptor phosphorylated the 80- and 105-kDa progesterone receptor subunits to an equal extent, whereas insulin-activated receptor preferentially phosphorylated the 80-kDa subunit. 2) Phosphopeptide fingerprinting analyses revealed that while insulin and EGF receptors phosphorylated one identical major site on both progesterone receptor subunits, they differed in their specificities for other sites. PMID:3001059

  9. Rotational diffusion of receptors for epidermal growth factor measured by time-resolved phosphorescence depolarization

    NASA Astrophysics Data System (ADS)

    Zidovetzki, Raphael; Johnson, David A.; Arndt-Jovin, Donna J.; Jovin, Thomas M.

    1991-06-01

    The cell surface receptor for epidermal growth factor (EGFR) is one of the most studied integral membrane proteins. The receptor is widely distributed in cells and tissues of mammalian and avian tissues and plays an important role in growth control. Binding of the epidermal growth factor (EGF) to EGFR initiates a complex biological response, which includes self-phosphorylation of the receptor due to an intrinsic tyrosine kinase activity, phosphorylation of other membrane proteins, increased intake of metabolites, and increased proliferation. Complete amino acid sequence of EGFR revealed a high degree of homology with viral oncogenes and allowed tentative identification of an external hormone binding domain, a transmembrane domain, and a cytoplasmic domain that includes tyrosine kinase activity. EGF binding induces rapid aggregation of EGFR, a process which was also observed on other receptor systems. These and other observations led to a hypothesis that microaggregation of EGFR is a necessary prerequisite for the biological response of EGF. A direct approach to study the processes of oligomerization of cell membrane proteins is to measure their mobility under various conditions. The lateral mobility of the EGFR was studied on mouse 3T3 fibroblasts and on A431 cells. However, an examination of the equations for the lateral and rotational diffusion in membranes shows that only rotational diffusion is strongly dependent on the size of the diffusing entity. A method of measuring protein rotational diffusion by time-resolved phosphorescence has proved to be very useful in the analysis of both in vivo and in vitro systems. The authors apply this method to study the mobility of EGFR on living A431 cells and membrane preparations.

  10. Epidermal growth factor receptors on PC12 cells: alteration of binding properties by lectins

    SciTech Connect

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

    1983-01-01

    The PC12 cell line displays cell surface receptors for both nerve growth factor (NGF) and epidermal growth factor (EGF). It has been previously shown that the lectin wheat germ agglutinin (WGA) alters the properties of NGF receptors on these cells. We now report that preincubations with either WGA or concanavalin A (Con A) decrease the binding of /sup 125/I-EGF to PC12 cells by greater than 50%. The inhibition of binding occurred at 37 degrees C and 4 degrees C and could be blocked or reversed by the addition of sugars which bind specifically to WGA or Con A. Scatchard analysis revealed that these lectins decreased binding primarily by lowering the affinity of the receptor and to a lesser extent by decreasing receptor number. Succinylation of Con A (sCon A) produced a derivative that was less effective than the native lectin in decreasing EGF binding; however, addition of an antibody against Con A restored the ability of sCon A to decrease binding. Similar to results obtained with /sup 125/I-NGF binding, WGA but not Con A was found to increase, by severalfold, the proportion of /sup 125/I-EGF binding that is resistant to solubilization by Triton X-100 detergent. A potential association of the EGF receptor with cytoskeletal elements is discussed which could account for such results.

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

    SciTech Connect

    Lin, T.H.; Mukku, V.R.; Verner, G.; Kirkland, J.L.; Stancel, G.M.

    1988-03-01

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

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

    PubMed Central

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

    2013-01-01

    Imaging single epidermal growth factor receptors (EGFR) in intact cells is presently limited by the available microscopy methods. Environmental scanning electron microscopy (ESEM) of whole cells in hydrated state in combination with specific labeling with gold nanoparticles was used to localize activated EGFRs in the plasma membranes of COS7 and A549 cells. The use of a scanning transmission electron microscopy (STEM) detector yielded a spatial resolution of 3 nm, sufficient to identify the locations of individual EGFR dimer subunits. The sizes and distribution of dimers and higher order clusters of EGFRs were determined. The distance between labels bound to dimers amounted to 19 nm, consistent with a molecular model. A fraction of the EGFRs was found in higher order clusters with sizes ranging from 32–56 nm. ESEM can be used for quantitative whole cell screening studies of membrane receptors, and for the study of nanoparticle-cell interactions in general. PMID:24022088

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

    PubMed

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

    2013-01-01

    Imaging single epidermal growth factor receptors (EGFR) in intact cells is presently limited by the available microscopy methods. Environmental scanning electron microscopy (ESEM) of whole cells in hydrated state in combination with specific labeling with gold nanoparticles was used to localize activated EGFRs in the plasma membranes of COS7 and A549 cells. The use of a scanning transmission electron microscopy (STEM) detector yielded a spatial resolution of 3 nm, sufficient to identify the locations of individual EGFR dimer subunits. The sizes and distribution of dimers and higher order clusters of EGFRs were determined. The distance between labels bound to dimers amounted to 19 nm, consistent with a molecular model. A fraction of the EGFRs was found in higher order clusters with sizes ranging from 32-56 nm. ESEM can be used for quantitative whole cell screening studies of membrane receptors, and for the study of nanoparticle-cell interactions in general.

  14. Epidermal Growth Factor Receptor Transactivation: Mechanisms, Pathophysiology, and Potential Therapies in the Cardiovascular System.

    PubMed

    Forrester, Steven J; Kawai, Tatsuo; O'Brien, Shannon; Thomas, Walter; Harris, Raymond C; Eguchi, Satoru

    2016-01-01

    Epidermal growth factor receptor (EGFR) activation impacts the physiology and pathophysiology of the cardiovascular system, and inhibition of EGFR activity is emerging as a potential therapeutic strategy to treat diseases including hypertension, cardiac hypertrophy, renal fibrosis, and abdominal aortic aneurysm. The capacity of G protein-coupled receptor (GPCR) agonists, such as angiotensin II (AngII), to promote EGFR signaling is called transactivation and is well described, yet delineating the molecular processes and functional relevance of this crosstalk has been challenging. Moreover, these critical findings are dispersed among many different fields. The aim of our review is to highlight recent advancements in defining the signaling cascades and downstream consequences of EGFR transactivation in the cardiovascular renal system. We also focus on studies that link EGFR transactivation to animal models of the disease, and we discuss potential therapeutic applications.

  15. Characterization of epidermal growth factor receptors on plasma membranes isolated from rat gastric mucosa

    SciTech Connect

    Hori, R.; Nomura, H.; Iwakawa, S.; Okumura, K. )

    1990-06-01

    The binding of human epidermal growth factor (hEGF), beta-urogastrone, to plasma membranes isolated from rat gastric mucosa was studied to characterize gastric EGF receptors. The binding of ({sup 125}I)hEGF was temperature dependent, reversible, and saturable. A single class of binding sites for EGF with a dissociation constant of 0.42 nM and maximal binding capacity of 42 fmol/mg protein was suggested. There was little change in the binding of ({sup 125}I)hEGF upon addition of peptide hormones (secretin, insulin), antiulcer drugs (cimetidine), or an ulcer-inducing reagent (aspirin). Cross-linking of ({sup 125}I)hEGF to gastric plasma membranes with the use of disuccinimidyl suberate resulted in the labeling of a protein of 150 kDa. These results indicate the presence of EGF receptors on plasma membranes of rat gastric mucosa.

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

    SciTech Connect

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

    1986-08-01

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

  17. Nitric oxide reversibly inhibits the epidermal growth factor receptor tyrosine kinase.

    PubMed Central

    Estrada, C; Gómez, C; Martín-Nieto, J; De Frutos, T; Jiménez, A; Villalobo, A

    1997-01-01

    Although it has been demonstrated that NO inhibits the proliferation of different cell types, the mechanisms of its anti-mitotic action are not well understood. In this work we have studied the possible interaction of NO with the epidermal growth factor receptor (EGFR), using transfected fibroblasts which overexpress the human EGFR. The NO donors S-nitroso-N-acetylpenicillamine (SNAP), 1,1-diethyl-2-hydroxy-2-nitrosohydrazine (DEA-NO) and N-¿4-[1-(3-aminopropyl)-2-hydroxy-2-nitrosohydrazino]butyl¿propane -1, 3-diamine (DETA-NO) inhibited DNA synthesis of fibroblasts growing in the presence of fetal calf serum, epidermal growth factor (EGF) or EGF plus insulin, as assessed by [methyl-3H]thymidine incorporation. Neither 8-bromo-cGMP nor the cGMP-phosphodiesterase inhibitor zaprinast mimicked this effect, suggesting that NO is unlikely to inhibit cell proliferation via a cGMP-dependent pathway. SNAP, DEA-NO and DETA-NO also inhibited the transphosphorylation of the EGFR and its tyrosine kinase activity toward the exogenous substrate poly-l-(Glu-Tyr), as measured in permeabilized cells using [gamma-32P]ATP as phosphate donor. In contrast, 3-[morpholinosydnonimine hydrochloride] (SIN-1), a peroxynitrite-forming compound, did not significantly inhibit either DNA synthesis or the EGFR tyrosine kinase activity. The inhibitory action of DEA-NO on the EGFR tyrosine kinase was prevented by haemoglobin, an NO scavenger, but not by superoxide dismutase, and was reversed by dithiothreitol. The binding of EGF to its receptor was unaffected by DEA-NO. The inhibitory action of DEA-NO on the EGF-dependent transphosphorylation of the receptor was also demonstrated in intact cells by immunoblot analysis using an anti-phosphotyrosine antibody. Taken together, these results suggest that NO, but not peroxynitrite, inhibits in a reversible manner the EGFR tyrosine kinase activity by S-nitrosylation of the receptor. PMID:9291107

  18. Discovery of Novel Human Epidermal Growth Factor Receptor-2 Inhibitors by Structure-based Virtual Screening

    PubMed Central

    Shi, Zheng; Yu, Tian; Sun, Rong; Wang, Shan; Chen, Xiao-Qian; Cheng, Li-Jia; Liu, Rong

    2016-01-01

    Background: Human epidermal growth factor receptor-2 (HER2) is a trans-membrane receptor like protein, and aberrant signaling of HER2 is implicated in many human cancers, such as ovarian cancer, gastric cancer, and prostate cancer, most notably breast cancer. Moreover, it has been in the spotlight in the recent years as a promising new target for therapy of breast cancer. Objective: Since virtual screening has become an integral part of the drug discovery process, it is of great significant to identify novel HER2 inhibitors by structure-based virtual screening. Materials and Methods: In this study, we carried out a series of elegant bioinformatics approaches, such as virtual screening and molecular dynamics (MD) simulations to identify HER2 inhibitors from Food and Drug Administration-approved small molecule drug as potential “new use” drugs. Results: Molecular docking identified top 10 potential drugs which showed spectrum affinity to HER2. Moreover, MD simulations suggested that ZINC08214629 (Nonoxynol-9) and ZINC03830276 (Benzonatate) might exert potential inhibitory effects against HER2-targeted anti-breast cancer therapeutics. Conclusion: Together, our findings may provide successful application of virtual screening studies in the lead discovery process, and suggest that our discovered small molecules could be effective HER2 inhibitor candidates for further study. SUMMARY A series of elegant bioinformatics approaches, including virtual screening and molecular dynamics (MD) simulations were took advantage to identify human epidermal growth factor receptor-2 (HER2) inhibitors. Molecular docking recognized top 10 candidate compounds, which showed spectrum affinity to HER2. Further, MD simulations suggested that ZINC08214629 (Nonoxynol-9) and ZINC03830276 (Benzonatate) in candidate compounds were identified as potential “new use” drugs against HER2-targeted anti-breast cancer therapeutics. Abbreviations used: HER2: Human epidermal growth factor receptor-2

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

    NASA Astrophysics Data System (ADS)

    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

  20. The prognostic value of epidermal growth factor receptor mRNA expression in primary ovarian cancer.

    PubMed Central

    Bartlett, J. M.; Langdon, S. P.; Simpson, B. J.; Stewart, M.; Katsaros, D.; Sismondi, P.; Love, S.; Scott, W. N.; Williams, A. R.; Lessells, A. M.; Macleod, K. G.; Smyth, J. F.; Miller, W. R.

    1996-01-01

    The expression of mRNA for the epidermal growth factor (EGF) receptor, EGF and transforming growth factor alpha (TGF-alpha) was determined in 76 malignant, six borderline and 15 benign primary ovarian tumours using the reverse transcriptase-polymerase chain reaction and related to clinical and pathological parameters. Of the malignant tumours, 70% (53/76) expressed EGF receptor mRNA, 31% (23/75) expressed EGF mRNA and 35% (26/75) expressed TGF-alpha mRNA. For the borderline tumours, four of six (67%) expressed EGF receptor mRNA, 1/6 (17%) expressed TGF-alpha mRNA and none expressed EGF mRNA. Finally, 33% (5/15) of the benign tumours expressed EGF receptor mRNA, whereas 40% (6/15) expressed EGF mRNA and 7% (1/15) expressed TGF-alpha mRNA. The presence of the EGF receptor in malignant tumours was associated with that of TGF-alpha (P = 0.0015) but not with EGF (P = 1.00), whereas there was no relationship between the presence of EGF and TGF-alpha (P = 1.00). EGF receptor mRNA expression was significantly and positively associated with serous histology (P = 0.006) but not with stage or grade. Neither EGF nor TGF-alpha showed any link with histological subtype or stage. The survival of patients with malignant tumours possessing EGF receptor mRNA was significantly reduced compared with that of patients whose tumours were negative (P = 0.030 for all malignant tumours; P = 0.007 for malignant epithelial tumours only). In contrast, neither the expression of TGF-alpha nor EGF was related to survival. These data suggest that the presence of EGF receptor mRNA is associated with poor prognosis in primary ovarian cancer. Images Figure 1 PMID:8562334

  1. The Under-Appreciated Promiscuity of the Epidermal Growth Factor Receptor Family

    PubMed Central

    Kennedy, Sean P.; Hastings, Jordan F.; Han, Jeremy Z. R.; Croucher, David R.

    2016-01-01

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

  2. The Under-Appreciated Promiscuity of the Epidermal Growth Factor Receptor Family.

    PubMed

    Kennedy, Sean P; Hastings, Jordan F; Han, Jeremy Z R; Croucher, David R

    2016-01-01

    Each member of the epidermal growth factor receptor (EGFR) family plays a key role in normal development, homeostasis, and a variety of pathophysiological conditions, most notably in cancer. According to the prevailing dogma, these four receptor tyrosine kinases (RTKs; EGFR, ERBB2, ERBB3, and ERBB4) function exclusively through the formation of homodimers and heterodimers within the EGFR family. These combinatorial receptor interactions are known to generate increased interactome diversity and therefore influence signaling output, subcellular localization and function of the heterodimer. This molecular plasticity is also thought to play a role in the development of resistance toward targeted cancer therapies aimed at these known oncogenes. Interestingly, many studies now challenge this dogma and suggest that the potential for EGFR family receptors to interact with more distantly related RTKs is much greater than currently appreciated. Here we discuss how the promiscuity of these oncogenic receptors may lead to the formation of many unexpected receptor pairings and the significant implications for the efficiency of many targeted cancer therapies. PMID:27597943

  3. The Under-Appreciated Promiscuity of the Epidermal Growth Factor Receptor Family

    PubMed Central

    Kennedy, Sean P.; Hastings, Jordan F.; Han, Jeremy Z. R.; Croucher, David R.

    2016-01-01

    Each member of the epidermal growth factor receptor (EGFR) family plays a key role in normal development, homeostasis, and a variety of pathophysiological conditions, most notably in cancer. According to the prevailing dogma, these four receptor tyrosine kinases (RTKs; EGFR, ERBB2, ERBB3, and ERBB4) function exclusively through the formation of homodimers and heterodimers within the EGFR family. These combinatorial receptor interactions are known to generate increased interactome diversity and therefore influence signaling output, subcellular localization and function of the heterodimer. This molecular plasticity is also thought to play a role in the development of resistance toward targeted cancer therapies aimed at these known oncogenes. Interestingly, many studies now challenge this dogma and suggest that the potential for EGFR family receptors to interact with more distantly related RTKs is much greater than currently appreciated. Here we discuss how the promiscuity of these oncogenic receptors may lead to the formation of many unexpected receptor pairings and the significant implications for the efficiency of many targeted cancer therapies. PMID:27597943

  4. Platelet Derived Growth Factor-B and Human Epidermal Growth Factor Receptor-2 Polymorphisms in Gall Bladder Cancer.

    PubMed

    Mishra, Kumudesh; Behari, Anu; Kapoor, Vinay Kumar; Khan, M Salman; Prakash, Swayam; Agrawal, Suraksha

    2015-01-01

    Gall bladder cancer (GBC) is a gastro-intestinal cancer with high prevalence among north Indian women. Platelet derived growth factor-B (PDGFB) and human epidermal growth factor receptor-2 (HER2) may play roles in the etiology of GBC through the inflammation-hyperplasia-dysplasia-carcinoma pathway. To study the association of PDGFB and HER2 polymorphisms with risk of GBC, 200 cases and 300 controls were considered. PDGFB +286A>G and +1135A>C polymorphisms were investigated with an amplification refractory mutation system and the HER2 Ile655Val polymorphism by restriction fragment length polymorphism. Significant risk associations for PDGFB +286 GG (OR=5.25) and PDGFB +1135 CC (OR=3.19) genotypes were observed for GBC. Gender wise stratification revealed susceptibility for recessive models of PDGFB +1135A>C (OR=3.00) and HER2 Ile655Val (OR=2.52) polymorphisms among female GBC cases. GBC cases with gall stones were predisposed to homozygous +286 GG and +1135 CC genotypes. Significant risk associations were found for ACIle (OR=1.48), GAVal (OR=1.70), GAIle (OR=2.00) haplotypes with GBC cases and GCIle haplotype with female GBC cases (OR=10.37, P=<0.0001). Pair-wise linkage disequilibrium revealed negative associations among variant alleles. On multi-dimensional reduction analysis, a three factor model revealed significant gene-gene interaction for PDGFB +286A>G, PDGFB +1135A>C and HER2 Ile165Val SNPs with GBC. Protein-protein interaction showed significant association of PDGFB and HER2 with the epidermal growth factor receptor signaling pathway. PMID:26320430

  5. Problem-Solving Test: The Role of Ubiquitination in Epidermal Growth Factor Receptor Trafficking

    ERIC Educational Resources Information Center

    Szeberenyi, Jozsef

    2012-01-01

    Terms to be familiar with before you start to solve the test: growth factor signaling, epidermal growth factor, tyrosine protein kinase, tyrosine phosphorylation, ubiquitin, monoubiquitination, polyubiquitination, site-directed mutagenesis, transfection, expression vector, cDNA, immunoprecipitation, SDS-polyacrylamide gel electrophoresis, Western…

  6. Thermodynamic mixing of molecular states of the epidermal growth factor receptor modulates macroscopic ligand binding affinity.

    PubMed Central

    Holbrook, M R; Slakey, L L; Gross, D J

    2000-01-01

    The epidermal growth factor receptor (EGFr), when expressed on the cell surface, has long been known to display two distinct affinities for epidermal growth factor (EGF) binding. In addition, the treatment of cells expressing the EGFr with phorbol esters has been shown to cause a loss of the high-affinity binding capacity of the receptor. In the present study, point mutations that alter acidic or phosphorylation sites have been made in an intracellular domain near Tyr-992 (residues 988-992) of the EGFr. Equilibrium (125)I-EGF binding studies demonstrate that the conversion of Tyr-992 into glutamate induces a 4-fold decrease in the EGFr apparent low-affinity dissociation constant, whereas the mutation of two acidic residues, Asp-988 and Glu-991, or the conversion of Tyr-992 into phenylalanine does not alter EGFr affinity. Phorbol ester treatment of EGFr-expressing Chinese hamster ovary cells results in a loss of high-affinity binding and an increase in the apparent low-affinity dissociation constant of the receptor, similar to the effect of a truncation mutant in which the C-terminal 190 residues are deleted. These results are examined in the context of a new model for regulation of the affinity of the EGFr for EGF in which a cytosolic particle stabilizes the high-affinity conformation of the EGFr and a rapid equilibrium exists between EGFr high-affinity and low-affinity conformations. This model demonstrates that the macroscopic affinities of the EGFr can differ from the affinities of individual EGFr molecules and provides a theoretical framework whereby the measured affinities of the EGFr are modulated by intracellular interactions. PMID:11062062

  7. Epidermal growth factor receptors destined for the nucleus are internalized via a clathrin-dependent pathway

    SciTech Connect

    De Angelis Campos, Ana Carolina; Rodrigues, Michele Angela; Andrade, Carolina de; Miranda de Goes, Alfredo; Nathanson, Michael H.; Gomes, Dawidson A.

    2011-08-26

    Highlights: {yields} EGF and its receptor translocates to the nucleus in liver cells. {yields} Real time imaging shows that EGF moves to the nucleus. {yields} EGF moves with its receptor to the nucleus. {yields} Dynamin and clathrin are necessary for EGFR nuclear translocation. -- Abstract: The epidermal growth factor (EGF) transduces its actions via the EGF receptor (EGFR), which can traffic from the plasma membrane to either the cytoplasm or the nucleus. However, the mechanism by which EGFR reaches the nucleus is unclear. To investigate these questions, liver cells were analyzed by immunoblot of cell fractions, confocal immunofluorescence and real time confocal imaging. Cell fractionation studies showed that EGFR was detectable in the nucleus after EGF stimulation with a peak in nuclear receptor after 10 min. Movement of EGFR to the nucleus was confirmed by confocal immunofluorescence and labeled EGF moved with the receptor to the nucleus. Small interference RNA (siRNA) was used to knockdown clathrin in order to assess the first endocytic steps of EGFR nuclear translocation in liver cells. A mutant dynamin (dynamin K44A) was also used to determine the pathways for this traffic. Movement of labeled EGF or EGFR to the nucleus depended upon dynamin and clathrin. This identifies the pathway that mediates the first steps for EGFR nuclear translocation in liver cells.

  8. Regulation of Epidermal Growth Factor Receptor Signaling by Endocytosis and Intracellular Trafficking

    SciTech Connect

    Burke, Patrick; Schooler, Kevin; Wiley, H S.

    2001-06-01

    Ligand activation of the epidermal growth factor receptor (EGFR) leads to its rapid internalization and eventual delivery to lysosomes. This process is thought to be a mechanism to attenuate signaling, but signals could potentially be generated following endocytosis. To directly evaluate EGFR signaling during receptor trafficking, we developed a technique to rapidly and selectively isolate internalized EGFR and associated molecules using reversibly-biotinylated anti-EGFR antibodies. In addition, we developed antibodies specific to tyrosine-phosphorylated EGFR. Using a combination of fluorescence imaging and affinity precipitation approaches, we evaluated the state of EGFR activation and substrate association during trafficking in epithelial cells. We found that following internalization, EGFR remained active in the early endosomes. However, receptors were inactivated prior to degradation, apparently due to ligand removal from endosomes. Adapter molecules, such as Shc, were associated with EGFR both at the cell surface and within endosomes. Some molecules, such as Grb2, were primarily found associated with surface EGFR, while others, such as Eps8, were only found with intracellular receptors. During the inactivation phase, c-Cbl became EGFR-associated, consistent with its postulated role in receptor attenuation. We conclude that the association of the EGFR with different proteins is compartment-specific . In addition, ligand loss is the proximal cause of EGFR inactivation. Thus, regulated trafficking could potentially influence the pattern as well as the duration of signal transduction.

  9. Non-canonical signaling mode of the epidermal growth factor receptor family

    PubMed Central

    Lee, Heng-Huan; Wang, Ying-Nai; Hung, Mien-Chie

    2015-01-01

    Epidermal growth factor receptor (EGFR) and its family members are key players in both physiological and pathological settings for which they are well recognized as models for investigating the functions and regulations of other membrane receptor tyrosine kinases (RTKs) and serve as therapeutic targets critical to clinical need and fundamental research. The canonical view of the pivotal functions in the EGFR family has been well documented as being an initiator of signaling amplification cascades from the plasma membrane to different subcellular compartments via receptor endocytic trafficking, intermolecular interaction, and kinase-substrate reaction in a temporalspatial manner. However, several lines of evidence have identified non-canonical roles of the EGFR family, acting as a transcriptional factor and a chromatin regulator in the nucleus to regulate gene expression, DNA replication, and DNA damage repair. Moreover, the EGFR family can even exert its impact outside the host cell through exosomal vesicle secretion. The emerging concept of the non-canonical roles of the EGFR family reveals an astonishing and elaborate scheme on the molecular functions of membrane RTKs, offering new insights into the receptor biology as well as the development of comprehensive therapeutic strategies in the future. PMID:26693051

  10. Erlotinib resistance in mouse models of epidermal growth factor receptor-induced lung adenocarcinoma

    PubMed Central

    Politi, Katerina; Fan, Pang-Dian; Shen, Ronglai; Zakowski, Maureen; Varmus, Harold

    2010-01-01

    SUMMARY Seventy-five percent of lung adenocarcinomas with epidermal growth factor receptor (EGFR) mutations respond to treatment with the tyrosine kinase inhibitors (TKIs) gefitinib and erlotinib; however, drug-resistant tumors eventually emerge. In 60% of cases, resistant tumors carry a secondary mutation in EGFR (T790M), amplification of MET, or both. Here, we describe the establishment of erlotinib resistance in lung tumors, which were induced by mutant EGFR, in transgenic mice after multiple cycles of drug treatment; we detect the T790M mutation in five out of 24 tumors or Met amplification in one out of 11 tumors in these mice. This preclinical mouse model, therefore, recapitulates the molecular changes responsible for resistance to TKIs in human tumors and holds promise for the discovery of additional mechanisms of drug resistance in lung cancer. PMID:20007486

  11. Erlotinib resistance in mouse models of epidermal growth factor receptor-induced lung adenocarcinoma.

    PubMed

    Politi, Katerina; Fan, Pang-Dian; Shen, Ronglai; Zakowski, Maureen; Varmus, Harold

    2010-01-01

    Seventy-five percent of lung adenocarcinomas with epidermal growth factor receptor (EGFR) mutations respond to treatment with the tyrosine kinase inhibitors (TKIs) gefitinib and erlotinib; however, drug-resistant tumors eventually emerge. In 60% of cases, resistant tumors carry a secondary mutation in EGFR (T790M), amplification of MET, or both. Here, we describe the establishment of erlotinib resistance in lung tumors, which were induced by mutant EGFR, in transgenic mice after multiple cycles of drug treatment; we detect the T790M mutation in five out of 24 tumors or Met amplification in one out of 11 tumors in these mice. This preclinical mouse model, therefore, recapitulates the molecular changes responsible for resistance to TKIs in human tumors and holds promise for the discovery of additional mechanisms of drug resistance in lung cancer.

  12. Gefitinib in the treatment of nonsmall cell lung cancer with activating epidermal growth factor receptor mutation

    PubMed Central

    Nurwidya, Fariz; Takahashi, Fumiyuki; Takahashi, Kazuhisa

    2016-01-01

    Lung cancer is still the main cause of cancer-related deaths worldwide, with most patients present with advanced disease and poor long-term prognosis. The aim of lung cancer treatment is to slow down the progression of the disease, to relieve the patients from the lung cancer symptoms and whenever possible, to increase the overall survival. The discovery of small molecule targeting tyrosine kinase of epidermal growth factor receptor opens a new way in the management of advanced nonsmall cell lung cancer (NSCLC). This review will discuss several Phase II and III trials evaluated the clinical efficacy of gefitinib as monotherapy in pretreated patients with advanced NSCLC, as well as both monotherapy and combined with chemotherapy in chemotherapy-naive patients. PMID:27433059

  13. A tale of the epidermal growth factor receptor: The quest for structural resolution on cells.

    PubMed

    Tynan, Christopher J; Lo Schiavo, Valentina; Zanetti-Domingues, Laura; Needham, Sarah R; Roberts, Selene K; Hirsch, Michael; Rolfe, Daniel J; Korovesis, Dimitrios; Clarke, David T; Martin-Fernandez, Marisa L

    2016-02-15

    The challenge of determining the architecture and geometry of oligomers of the epidermal growth factor receptor (EGFR) on the cell surface has been approached using a variety of biochemical and biophysical methods. This review is intended to provide a narrative of how key concepts in the field of EGFR research have evolved over the years, from the origins of the prevalent EGFR signalling dimer hypothesis through to the development and implementation of methods that are now challenging the conventional view. The synergy between X-ray crystallography and cellular fluorescence microscopy has become particularly important, precisely because the results from these two methods diverged and highlighted the complexity of the challenge. We illustrate how developments in super-resolution microscopy are now bridging this gap. Exciting times lie ahead where knowledge of the nature of the complexes can assist with the development of a new generation of anti-cancer drugs. PMID:26484734

  14. Epidermal growth factor receptor localized to exosome membranes as a possible biomarker for lung cancer diagnosis.

    PubMed

    Yamashita, T; Kamada, H; Kanasaki, S; Maeda, Y; Nagano, K; Abe, Y; Inoue, M; Yoshioka, Y; Tsutsumi, Y; Katayama, S; Inoue, M; Tsunoda, S

    2013-12-01

    Detection of drug-target proteins and biomarkers that are expressed in cancer tissue has significant potential for both diagnosis and treatment of cancer. However, current immuno-histochemical and cytogenetic analyses of biopsy specimens for pre-operational diagnosis are highly invasive and often difficult to apply to lung cancer patients. The purpose of this study was to evaluate the possible utility of determining epidermal growth factor receptor (EGFR) expression on exosomal membranes using a targeted ELISA with an anti-CD81 antibody as a capture antibody for lung cancer diagnosis. While soluble EGFR (sEGFR) levels in plasma were not remarkably different between lung cancer patients and normal controls, significantly higher exosomal EGFR expression levels were observed in 5/9 cancer cases compared to normal controls. These results suggest that measurement of exosomal protein levels could be useful for in vitro diagnosis, and that exosomal EGFR is a possible biomarker for characterization of lung cancer.

  15. QSAR and 3D QSAR of inhibitors of the epidermal growth factor receptor

    NASA Astrophysics Data System (ADS)

    Pinto-Bazurco, Mariano; Tsakovska, Ivanka; Pajeva, Ilza

    This article reports quantitative structure-activity relationships (QSAR) and 3D QSAR models of 134 structurally diverse inhibitors of the epidermal growth factor receptor (EGFR) tyrosine kinase. Free-Wilson analysis was used to derive the QSAR model. It identified the substituents in aniline, the polycyclic system, and the substituents at the 6- and 7-positions of the polycyclic system as the most important structural features. Comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA) were used in the 3D QSAR modeling. The steric and electrostatic interactions proved the most important for the inhibitory effect. Both QSAR and 3D QSAR models led to consistent results. On the basis of the statistically significant models, new structures were proposed and their inhibitory activities were predicted.

  16. Unique presentations of epidermal growth factor receptor inhibitor-induced papulopustular eruption related to bacterial superinfection.

    PubMed

    Wiznia, Lauren Elyse; Choi, Jennifer Nam

    2013-01-01

    Epidermal growth factor receptor (EGFR) inhibitors have been reported to induce numerous cutaneous side effects, the most notable of which is a papulopustular eruption on the face, scalp, and central chest. The typical presentation consists of inflamed papules, often with pustules, favoring a seborrheic distribution. The pustules of the EGFR inhibitor-induced papulopustular eruption are commonly sterile but bacterial superinfection is not uncommon. We report two unique presentations of the papulopustular eruption that were found to be associated with Staphylococcus aureus superinfection. One patient presented with an abrupt onset of nearly confluent red plaques on the cheeks, forehead, chin, and neck, with innumerable studded pinpoint pustules. The other patient had a long-standing untreated papulopustular eruption on the scalp, which resulted in widespread erythema, large thick plaques of serous crust, pustular exudate, and associated alopecia. Both patients quickly resolved with non-tetracycline oral antibiotics combined with topical steroid treatment. PMID:23552005

  17. Epidermal growth factor receptor numbers in male and female mouse primary hepatocyte cultures.

    PubMed

    Benveniste, R; Danoff, T M; Ilekis, J; Craig, H R

    1988-10-01

    Epidermal growth factor receptors (EGF-R) were measured in adult male and female mouse primary hepatocyte cultures. On culture day 1, female hepatocytes had significantly fewer EGF-R than male hepatocytes (1.3 x 10(4) versus 6.2 x 10(5) per cell). Over the next three days, morphological changes consistent with progressive heptocyte dedifferentiation were observed. During this period, EGF-R numbers progressively increased in female cultures and decreased in male cultures, and by day 4 the sexual difference in EGF-R numbers was obliterated. These results indicate that a relationship exists between the degree of differentiation in hepatocyte cultures and the expression of EGF-R on the cell surface.

  18. Multiple Mechanisms Are Responsible for Transactivation of the Epidermal Growth Factor Receptor in Mammary Epithelial Cells*

    PubMed Central

    Rodland, Karin D.; Bollinger, Nikki; Ippolito, Danielle; Opresko, Lee K.; Coffey, Robert J.; Zangar, Richard; Wiley, H. Steven

    2008-01-01

    The number of distinct signaling pathways that can transactivate the epidermal growth factor receptor (EGFR) in a single cell type is unclear. Using a single strain of human mammary epithelial cells, we found that a wide variety of agonists, such as lysophosphatidic acid (LPA), uridine triphosphate, growth hormone, vascular endothelial growth factor, insulin-like growth factor-1 (IGF-1), and tumor necrosis factor-α, require EGFR activity to induce ERK phosphorylation. In contrast, hepatocyte growth factor can stimulate ERK phosphorylation independent of the EGFR. EGFR transactivation also correlated with an increase in cell proliferation and could be inhibited with metalloprotease inhibitors. However, there were significant differences with respect to transactivation kinetics and sensitivity to different inhibitors. In particular, IGF-1 displayed relatively slow transactivation kinetics and was resistant to inhibition by the selective ADAM-17 inhibitor WAY-022 compared with LPA-induced transactivation. Studies using anti-ligand antibodies showed that IGF-1 transactivation required amphiregulin production, whereas LPA was dependent on multiple ligands. Direct measurement of ligand shedding confirmed that LPA treatment stimulated shedding of multiple EGFR ligands, but paradoxically, IGF-1 had little effect on the shedding rate of any ligand, including amphiregulin. Instead, IGF-1 appeared to work by enhancing EGFR activation of Ras in response to constitutively produced amphiregulin. This enhancement of EGFR signaling was independent of both receptor phosphorylation and PI-3-kinase activity, suggestive of a novel mechanism. Our studies demonstrate that within a single cell type, the EGFR autocrine system can couple multiple signaling pathways to ERK activation and that this modulation of EGFR autocrine signaling can be accomplished at multiple regulatory steps. PMID:18782770

  19. Phosphatidylinositol-4,5-bisphosphate regulates epidermal growth factor receptor activation

    PubMed Central

    Michailidis, Ioannis E.; Rusinova, Radda; Georgakopoulos, Anastasios; Chen, Yibang; Iyengar, Ravi; Robakis, Nikolaos K.; Logothetis, Diomedes E.; Baki, Lia

    2012-01-01

    Phosphatidylinositol-4,5-bisphosphate [PI(4,5)P2 or PIP2] is a direct modulator of a diverse array of proteins in eukaryotic cells. The functional integrity of transmembrane proteins, such as ion channels and transporters, is critically dependent on specific interactions with PIP2 and other phosphoinositides. Here, we report a novel requirement for PIP2 in the activation of the epidermal growth factor receptor (EGFR). Down-regulation of PIP2 levels either via pharmacological inhibition of PI kinase activity, or via manipulation of the levels of the lipid kinase PIP5K1α and the lipid phosphatase synaptojanin, reduced EGFR tyrosine phosphorylation, whereas up-regulation of PIP2 levels via overexpression of PIP5K1α had the opposite effect. A cluster of positively charged residues in the juxtamembrane domain (basic JD) of EGFR is likely to mediate binding of EGFR to PIP2 and PIP2-dependent regulation of EGFR activation. A peptide mimicking the EGFR juxtamembrane domain that was assayed by surface plasmon resonance displayed strong binding to PIP2. Neutralization of positively charged amino acids abolished EGFR/PIP2 interaction in the context of this peptide and down-regulated epidermal growth factor (EGF)-induced EGFR autophosphorylation and EGF-induced EGFR signaling to ion channels in the context of the full-length receptor. These results suggest that EGFR activation and downstream signaling depend on interactions of EGFR with PIP2 and point to the basic JD’s critical involvement in these interactions. The addition of this very different class of membrane proteins to ion channels and transporters suggests that PIP2 may serve as a general modulator of the activity of many diverse eukaryotic transmembrane proteins through their basic JDs. PMID:21107857

  20. Tissue kallikrein mediates neurite outgrowth through epidermal growth factor receptor and flotillin-2 pathway in vitro.

    PubMed

    Lu, Zhengyu; Cui, Mei; Zhao, Hong; Wang, Tao; Shen, Yan; Dong, Qiang

    2014-02-01

    Tissue kallikrein (TK) was previously shown to take most of its biological effects through bradykinin receptors. In this study, we assumed that TK mediated neurite outgrowth was independent of bradykinin receptors. To test the hypothesis, we investigated TK-induced neurite outgrowth and its signaling mechanisms in cultured primary neurons and human SH-SY5Y cells. We found that TK stimulation could increase the number of processes and mean process length of primary neurons, which were blocked by epidermal growth factor receptor (EGFR) inhibitor or down-regulation, small interfering RNA for flotillin-2 and extracellular signal-regulated kinase (ERK) 1/2 inhibitor. Moreover, TK-induced neurite outgrowth was associated with EGFR and ERK1/2 activation, which were inhibited by EGFR antagonist or RNA interference and flotillin-2 knockdown. Interestingly, inhibition of bradykinin receptors had no significant effects on EGFR and ERK1/2 phosphorylation. In the present research, our data also suggested that EGFR and flotillin-2 formed constitutive complex that translocated to around the nuclei in the TK stimulation. In sum, our findings provided evidence that TK could promote neurite outgrowth via EGFR, flotillin-2 and ERK1/2 signaling pathway in vitro. PMID:24211626

  1. Galectin-3 regulates intracellular trafficking of epidermal growth factor receptor through Alix and promotes keratinocyte migration

    PubMed Central

    Liu, Wei; Hsu, Daniel K.; Chen, Huan-Yuan; Yang, Ri-Yao; Carraway, Kermit L.; Isseroff, Roslyn R.; Liu, Fu-Tong

    2012-01-01

    The epidermal growth factor receptor (EGFR)-mediated signaling pathways are important in a variety of cellular processes, including cell migration and wound re-epithelialization. Intracellular trafficking of EGFR is critical for maintaining EGFR surface expression. Galectin-3, a member of an animal lectin family, has been implicated in a number of physiological and pathological processes. Through studies of galectin-3-deficient mice and cells isolated from these mice, we demonstrated that absence of galectin-3 impairs keratinocyte migration and skin wound re-epithelialization. We have linked this pro-migratory function to a crucial role of cytosolic galectin-3 in controlling intracellular trafficking and cell surface expression of EGFR after EGF stimulation. Without galectin-3, the surface levels of EGFR are dramatically reduced and the receptor accumulates diffusely in the cytoplasm. This is associated with reduced rates of both endocytosis and recycling of the receptor. We have provided evidence that this novel function of galectin-3 may be mediated through interaction with its binding partner Alix, which is a protein component of the endosomal sorting complex required for transport (ESCRT) machinery. Our results suggest that galectin-3 is potentially a critical regulator of a number of important cellular responses through its intracellular control of trafficking of cell surface receptors. PMID:22785133

  2. Effect of glucocorticoid on epidermal growth factor receptor in human salivary gland adenocarcinoma cell line HSG.

    PubMed

    Kyakumoto, S; Kurokawa, R; Ota, M

    1990-07-12

    Human salivary gland adenocarcinoma (HSG) cells treated with 10(-6) M triamcinolone acetonide for 48 h exhibited a 1.7- to 2.0-fold increase in [125I]human epidermal growth factor (hEGF) binding capacity as compared with untreated HSG cells. Scatchard analysis of [125I]EGF binding data revealed that the number of binding sites was 83,700 (+/- 29,200) receptors/cell in untreated cells and 160,500 (+/- 35,500) receptors/cell in treated cells. No substantial change in receptor affinity was detected. The dissociation constant of the EGF receptor was 0.78 (+/- 0.26).10(-9) M for untreated cells, whereas it was 0.93 (+/- 0.31).10(-9)M for treated cells. The triamcinolone acetonide-induced increase in [125I]EGF binding capacity was dose-dependent between 10(-9) and 10(-6)M, and maximal binding was observed at 10(-6)M. EGF receptors on HSG cells were affinity-labeled with [125I]EGF by use of the cross-linking reagent disuccinimidyl suberate (DSS). The cross-linked [125I]EGF was 3-4% of the total [125I]EGF bound to HSG cells. The affinity-labeled EGF receptor was detected as a specific 170 kDa band in the autoradiograph after SDS-polyacrylamide gel electrophoresis (SDS-PAGE). Densitometric analysis revealed that triamcinolone acetonide amplified the intensity of this band 2.0-fold over that of the band of untreated cells. EGF receptor synthesis was also measured by immunoprecipitation of [3H]leucine-labeled EGF receptor protein with anti-hEGF receptor monoclonal antibody. Receptor synthesis was increased 1.7- to 1.8-fold when HSG cells were treated with 10(-8)-10(-6)M triamcinolone acetonide for 48 h. When the immunoprecipitated, [35S]methionine-pulse-labeled EGF receptor was analyzed by SDS-PAGE and fluorography, the newly synthesized EGF receptor was detected at the position of 170 kDa; and treatment of HSG cells with triamcinolone acetonide resulted in a 2.0-fold amplification of this 170 kDa band. There was no significant difference in turnover rate of EGF receptor

  3. Epidermal growth factor receptor in the prawn Macrobrachium rosenbergii: function and putative signaling cascade.

    PubMed

    Sharabi, Omri; Ventura, Tomer; Manor, Rivka; Aflalo, Eliahu D; Sagi, Amir

    2013-09-01

    Epidermal growth factor receptors (EGFRs) are highly conserved members of the tyrosine kinase receptor superfamily found in metazoans and plants. In arthropods, EGFRs are vital for the proper development of embryos and of adult limbs, gonads, and eyes as well as affecting body size. In searching for genes involved in the growth and development of our model organism, the decapod crustacean (Macrobrachium rosenbergii), a comprehensive transcript library was established using next-generation sequencing. Using this library, the expression of several genes assigned to the signal transduction pathways mediated by EGFRs was observed, including a transcript encoding M. rosenbergii EGFR (Mr-EGFR), several potential ligands upstream to the receptor, and most of the putative downstream signal transducer genes. The deduced protein encoded by Mr-EGFR, representing the first such receptor reported thus far in crustaceans, shows sequence similarity to other arthropod EGFRs. The M. rosenbergii gene is expressed in most tested tissues. The role of Mr-EGFR was revealed by temporarily silencing the transcript through weekly injections of double-stranded Mr-EGFR RNA. Such treatment resulted in a significant reduction in growth and a delay in the appearance of a male secondary sexual characteristic, namely the appendix masculina. An additional function of Mr-EGFR was revealed with respect to eye development. Although the optic ganglion appeared to have retained its normal morphology, Mr-EGFR-silenced individuals developed abnormal eyes that presented irregular organization of the ommatidia, reflected by unorganized receptor cells occupying large areas of the dioptric portion and by a shortened crystalline tract layer.

  4. A mutant epidermal growth factor receptor common in human glioma confers enhanced tumorigenicity.

    PubMed Central

    Nishikawa, R; Ji, X D; Harmon, R C; Lazar, C S; Gill, G N; Cavenee, W K; Huang, H J

    1994-01-01

    The development and neoplastic progression of human astrocytic tumors appears to result through an accumulation of genetic alterations occurring in a relatively defined order. One such alteration is amplification of the epidermal growth factor receptor (EGFR) gene. This episomal amplification occurs in 40-50% of glioblastomas, which also normally express endogenous receptors. Moreover, a significant fraction of amplified genes are rearranged to specifically eliminate a DNA fragment containing exons 2-7 of the gene, resulting in an in-frame deletion of 801 bp of the coding sequence of the extracellular domain. Here we used retroviral transfer of such a mutant receptor (de 2-7 EGFR) into glioblastoma cells expressing normal endogenous receptors to test whether the mutant receptor was able to augment their growth and malignancy. Western blotting analysis showed that these cells expressed endogenous EGFR of 170 kDa as well as the exogenous de 2-7 EGFR of 140-155 kDa. Although holo-EGFRs were phosphorylated on tyrosine residues only after exposure of the cells to ligand, de 2-7 EGFRs were constitutively phosphorylated. In tissue culture neither addition of EGF nor expression of the mutant EGFR affected the rate of cell growth. However, when cells expressing mutant EGFR were implanted into nude mice subcutaneously or intracerebrally, tumorigenic capacity was greatly enhanced. These results suggest that a tumor-specific alteration of the EGFR plays a significant role in tumor progression perhaps by influencing interactions of tumor cells with their microenvironment in ways not easily assayed in vitro. Images PMID:8052651

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

    PubMed

    Mi, Li-Zhi; Grey, Michael J; Nishida, Noritaka; Walz, Thomas; Lu, Chafen; Springer, Timothy A

    2008-09-30

    Cellular signaling mediated by the epidermal growth factor receptor (EGFR or ErbB) family of receptor tyrosine kinases plays an important role in regulating normal and oncogenic cellular physiology. While structures of isolated EGFR extracellular domains and intracellular protein tyrosine kinase domains have suggested mechanisms for growth factor-mediated receptor dimerization and allosteric kinase domain activation, understanding how the transmembrane and juxtamembrane domains contribute to transmembrane signaling requires structural studies on intact receptor molecules. In this report, recombinant EGFR constructs containing the extracellular, transmembrane, juxtamembrane, and kinase domains are overexpressed and purified from human embryonic kidney 293 cell cultures. The oligomerization state, overall structure, and functional stability of the purified EGF-bound receptor are characterized in detergent micelles and phospholipid bilayers. In the presence of EGF, catalytically active EGFR dimers can be isolated by gel filtration in dodecyl maltoside. Visualization of the dimeric species by negative stain electron microscopy and single particle averaging reveals an overall structure of the extracellular domain that is similar to previously published crystal structures and is consistent with the C-termini of domain IV being juxtaposed against one another as they enter the transmembrane domain. Although detergent-soluble preparations of EGFR are stable as dimers in the presence of EGF, they exhibit differential functional stability in Triton X-100 versus dodecyl maltoside. Furthermore, the kinase activity can be significantly stabilized by reconstituting purified EGF-bound EGFR dimers in phospholipid nanodiscs or vesicles, suggesting that the environment around the hydrophobic transmembrane and amphipathic juxtamembrane domains is important for stabilizing the tyrosine kinase activity in vitro.

  6. Soluble Epidermal Growth Factor Receptors (sEGFRs) in Cancer: Biological Aspects and Clinical Relevance

    PubMed Central

    Maramotti, Sally; Paci, Massimiliano; Manzotti, Gloria; Rapicetta, Cristian; Gugnoni, Mila; Galeone, Carla; Cesario, Alfredo; Lococo, Filippo

    2016-01-01

    The identification of molecules that can reliably detect the presence of a tumor or predict its behavior is one of the biggest challenges of research in cancer biology. Biological fluids are intriguing mediums, containing many molecules that express the individual health status and, accordingly, may be useful in establishing the potential risk of cancer, defining differential diagnosis and prognosis, predicting the response to treatment, and monitoring the disease progression. The existence of circulating soluble growth factor receptors (sGFRs) deriving from their membrane counterparts has stimulated the interest of researchers to investigate the use of such molecules as potential cancer biomarkers. But what are the origins of circulating sGFRs? Are they naturally occurring molecules or tumor-derived products? Among these, the epidermal growth factor receptor (EGFR) is a cell-surface molecule significantly involved in cancer development and progression; it can be processed into biological active soluble isoforms (sEGFR). We have carried out an extensive review of the currently available literature on the sEGFRs and their mechanisms of regulation and biological function, with the intent to clarify the role of these molecules in cancer (and other pathological conditions) and, on the basis of the retrieved evidences, speculate about their potential use in the clinical setting. PMID:27104520

  7. Parabens and Human Epidermal Growth Factor Receptor Ligand Cross-Talk in Breast Cancer Cells

    PubMed Central

    Pan, Shawn; Yuan, Chaoshen; Tagmount, Abderrahmane; Rudel, Ruthann A.; Ackerman, Janet M.; Yaswen, Paul; Vulpe, Chris D.; Leitman, Dale C.

    2015-01-01

    Background: Xenoestrogens are synthetic compounds that mimic endogenous estrogens by binding to and activating estrogen receptors. Exposure to estrogens and to some xenoestrogens has been associated with cell proliferation and an increased risk of breast cancer. Despite evidence of estrogenicity, parabens are among the most widely used xenoestrogens in cosmetics and personal-care products and are generally considered safe. However, previous cell-based studies with parabens do not take into account the signaling cross-talk between estrogen receptor α (ERα) and the human epidermal growth factor receptor (HER) family. Objectives: We investigated the hypothesis that the potency of parabens can be increased with HER ligands, such as heregulin (HRG). Methods: The effects of HER ligands on paraben activation of c-Myc expression and cell proliferation were determined by real-time polymerase chain reaction, Western blots, flow cytometry, and chromatin immunoprecipitation assays in ERα- and HER2-positive human BT-474 breast cancer cells. Results: Butylparaben (BP) and HRG produced a synergistic increase in c-Myc mRNA and protein levels in BT-474 cells. Estrogen receptor antagonists blocked the synergistic increase in c-Myc protein levels. The combination of BP and HRG also stimulated proliferation of BT-474 cells compared with the effects of BP alone. HRG decreased the dose required for BP-mediated stimulation of c-Myc mRNA expression and cell proliferation. HRG caused the phosphorylation of serine 167 in ERα. BP and HRG produced a synergistic increase in ERα recruitment to the c-Myc gene. Conclusion: Our results show that HER ligands enhanced the potency of BP to stimulate oncogene expression and breast cancer cell proliferation in vitro via ERα, suggesting that parabens might be active at exposure levels not previously considered toxicologically relevant from studies testing their effects in isolation. Citation: Pan S, Yuan C, Tagmount A, Rudel RA, Ackerman JM

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

    PubMed

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

    2008-05-14

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

  9. Fluorescence techniques used to measure interactions between hydroxyapatite nanoparticles and epidermal growth factor receptors.

    PubMed

    Kathawala, Mustafa H; Khoo, Stella P K; Sudhaharan, Thankiah; Zhao, Xinxin; Say Chye Loo, Joachim; Ahmed, Sohail; Woei Ng, Kee

    2015-01-01

    The potential applications of nanomaterials in therapeutics are immense and to fully explore this potential, it is important to understand the interaction of nanoparticles with cellular components. To examine the interaction between nanoparticles and cell membrane receptors, this report describes the use of advanced fluorescence techniques to measure interactions between hydroxyapatite (HA) nanoparticles and epidermal growth factor receptors (EGFRs), as a model system. FITC-labelled HA nanoparticles and monomeric red fluorescent protein (mRFP)-conjugated EGFRs expressed in Chinese hamster ovary cells (CHO-K1) were generated and their interaction measured using acceptor photobleaching-fluorescence resonance energy transfer (AP-FRET) and fluorescence lifetime imaging microscopy-fluorescence resonance energy transfer (FLIM-FRET). Results confirmed that hydroxyapatite nanoparticles not only interacted with EGFR but also attenuated downstream EGFR signalling, possibly by hindering normal dimerization of EGFR. Furthermore, the extent of signal attenuation suggested correlation with specific surface area of the nanoparticles, whereby greater specific surface area resulted in greater downstream signal attenuation. This novel demonstration establishes fluorescence techniques as a viable method to study nanoparticle interactions with proteins such as cell surface receptors. The approach described herein can be extended to study interactions between any fluorescently labelled nanoparticle-biomolecule pair.

  10. Immunotoxin Therapies for the Treatment of Epidermal Growth Factor Receptor-Dependent Cancers

    PubMed Central

    Simon, Nathan; FitzGerald, David

    2016-01-01

    Many epithelial cancers rely on enhanced expression of the epidermal growth factor receptor (EGFR) to drive proliferation and survival pathways. Development of therapeutics to target EGFR signaling has been of high importance, and multiple examples have been approved for human use. However, many of the current small molecule or antibody-based therapeutics are of limited effectiveness due to the inevitable development of resistance and toxicity to normal tissues. Recombinant immunotoxins are therapeutic molecules consisting of an antibody or receptor ligand joined to a protein cytotoxin, combining the specific targeting of a cancer-expressed receptor with the potent cell killing of cytotoxic enzymes. Over the decades, many bacterial- or plant-based immunotoxins have been developed with the goal of targeting the broad range of cancers reliant upon EGFR overexpression. Many examples demonstrate excellent anti-cancer properties in preclinical development, and several EGFR-targeted immunotoxins have progressed to human trials. This review summarizes much of the past and current work in the development of immunotoxins for targeting EGFR-driven cancers. PMID:27153091

  11. Enhanced dimerization drives ligand-independent activity of mutant epidermal growth factor receptor in lung cancer

    PubMed Central

    Valley, Christopher C.; Arndt-Jovin, Donna J.; Karedla, Narain; Steinkamp, Mara P.; Chizhik, Alexey I.; Hlavacek, William S.; Wilson, Bridget S.; Lidke, Keith A.; Lidke, Diane S.

    2015-01-01

    Mutations within the epidermal growth factor receptor (EGFR/erbB1/Her1) are often associated with tumorigenesis. In particular, a number of EGFR mutants that demonstrate ligand-independent signaling are common in non–small cell lung cancer (NSCLC), including kinase domain mutations L858R (also called L834R) and exon 19 deletions (e.g., ΔL747-P753insS), which collectively make up nearly 90% of mutations in NSCLC. The molecular mechanisms by which these mutations confer constitutive activity remain unresolved. Using multiple subdiffraction-limit imaging modalities, we reveal the altered receptor structure and interaction kinetics of NSCLC-associated EGFR mutants. We applied two-color single quantum dot tracking to quantify receptor dimerization kinetics on living cells and show that, in contrast to wild-type EGFR, mutants are capable of forming stable, ligand-independent dimers. Two-color superresolution localization microscopy confirmed ligand-independent aggregation of EGFR mutants. Live-cell Förster resonance energy transfer measurements revealed that the L858R kinase mutation alters ectodomain structure such that unliganded mutant EGFR adopts an extended, dimerization-competent conformation. Finally, mutation of the putative dimerization arm confirmed a critical role for ectodomain engagement in ligand-independent signaling. These data support a model in which dysregulated activity of NSCLC-associated kinase mutants is driven by coordinated interactions involving both the kinase and extracellular domains that lead to enhanced dimerization. PMID:26337388

  12. Establishing an Indicator of Hypokalemia in Patients Receiving Anti-Epidermal Growth Factor Receptor Antibodies.

    PubMed

    Yasuda, Masahiro; Tachi, Tomoya; Umeda, Michi; Osawa, Tomohiro; Makino, Teppei; Nagaya, Katsuhiro; Koda, Akihide; Setta, Eriko; Matsui, Koji; Nishina, Takuo; Yamada, Makoto; Goto, Chitoshi; Teramachi, Hitomi

    2016-03-01

    Risk factors for hypokalemia were analyzed in patients who received anti-epidermal growth factor receptor monoclonal antibodies (anti-EGFR MoAbs) at Gifu Municipal Hospital between February 2010 and March 2013. Subjects were 51 patients (27 men and 24 women) with the median age (interquartile range) of 66 (63-72) years. The study period started from the initiation of anti-EGFR MoAbs administration and ended 4 weeks after administration was completed. Patients were categorized into the side effect group if both minimum serum potassium (Min S-K) grade and b grade (pre-treatment S-K grade-Min S-K grade) were B1; otherwise, they were placed into the no side effect group. Univariate analysis for factors to prevent the side effect identified the "concomitant use of hyperkalemia-inducing drugs" to be statistically significant (p=0.010). Multivariate analysis was conducted on factors with a p value of <0.25 in the univariate analysis and on "concomitant use of hyperkalemia-inducing drugs," which was likely to clinically affect S-K decrease, although its p value was >0.25. It showed that "concomitant use of hyperkalemia-inducing drugs" was a significant risk-prevention factor (odds ratio: 0.138, 95% confidence interval[CI]: 0.033-0.581, p=0.007). In conclusion, "concomitant use of hyperkalemia-inducing drugs" is a factor associated with preventing hypokalemia accompanying anti-EGFR MoAbs administration.

  13. Transactivation of Epidermal Growth Factor Receptor by G Protein-Coupled Receptors: Recent Progress, Challenges and Future Research

    PubMed Central

    Wang, Zhixiang

    2016-01-01

    Both G protein-coupled receptors (GPCRs) and receptor-tyrosine kinases (RTKs) regulate large signaling networks, control multiple cell functions and are implicated in many diseases including various cancers. Both of them are also the top therapeutic targets for disease treatment. The discovery of the cross-talk between GPCRs and RTKs connects these two vast signaling networks and complicates the already complicated signaling networks that regulate cell signaling and function. In this review, we focus on the transactivation of epidermal growth factor receptor (EGFR), a subfamily of RTKs, by GPCRs. Since the first report of EGFR transactivation by GPCR, significant progress has been made including the elucidation of the mechanisms underlying the transactivation. Here, we first provide a basic picture for GPCR, EGFR and EGFR transactivation by GPCR. We then discuss the progress made in the last five years and finally provided our view of the future challenge and future researches needed to overcome these challenges. PMID:26771606

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

    SciTech Connect

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

    2008-05-01

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

  15. Epidermal Growth Factor Receptor-Dependent Mutual Amplification between Netrin-1 and the Hepatitis C Virus

    PubMed Central

    Plissonnier, Marie-Laure; Lahlali, Thomas; Michelet, Maud; Lebossé, Fanny; Cottarel, Jessica; Beer, Melanie; Neveu, Grégory; Durantel, David; Bartosch, Birke; Accardi, Rosita; Clément, Sophie; Paradisi, Andrea; Devouassoux-Shisheboran, Mojgan; Einav, Shirit; Mehlen, Patrick; Zoulim, Fabien; Parent, Romain

    2016-01-01

    Hepatitis C virus (HCV) is an oncogenic virus associated with the onset of hepatocellular carcinoma (HCC). The present study investigated the possible link between HCV infection and Netrin-1, a ligand for dependence receptors that sustains tumorigenesis, in particular in inflammation-associated tumors. We show that Netrin-1 expression is significantly elevated in HCV+ liver biopsies compared to hepatitis B virus (HBV+) and uninfected samples. Furthermore, Netrin-1 was upregulated in all histological stages of HCV+ hepatic lesions, from minimal liver fibrosis to cirrhosis and HCC, compared to histologically matched HCV- tissues. Both cirrhosis and HCV contributed to the induction of Netrin-1 expression, whereas anti-HCV treatment resulted in a reduction of Netrin-1 expression. In vitro, HCV increased the level and translation of Netrin-1 in a NS5A-La-related protein 1 (LARP1)-dependent fashion. Knockdown and forced expression experiments identified the receptor uncoordinated receptor-5 (UNC5A) as an antagonist of the Netrin-1 signal, though it did not affect the death of HCV-infected cells. Netrin-1 enhanced infectivity of HCV particles and promoted viral entry by increasing the activation and decreasing the recycling of the epidermal growth factor receptor (EGFR), a protein that is dysregulated in HCC. Netrin-1 and HCV are, therefore, reciprocal inducers in vitro and in patients, as seen from the increase in viral morphogenesis and viral entry, both phenomena converging toward an increase in the level of infectivity of HCV virions. This functional association involving a cancer-related virus and Netrin-1 argues for evaluating the implication of UNC5 receptor ligands in other oncogenic microbial species. PMID:27031829

  16. ADAM binding protein Eve-1 is required for ectodomain shedding of epidermal growth factor receptor ligands.

    PubMed

    Tanaka, Motonari; Nanba, Daisuke; Mori, Seiji; Shiba, Fumio; Ishiguro, Hiroshi; Yoshino, Koichiro; Matsuura, Nariaki; Higashiyama, Shigeki

    2004-10-01

    A disintegrin and metalloproteases (ADAMs) are implicated in the ectodomain shedding of epidermal growth factor receptor (EGFR) ligands in EGFR transactivation. However, the activation mechanisms of ADAMs remain elusive. To analyze the regulatory mechanisms of ADAM activation, we performed yeast two-hybrid screening using the cytoplasmic domain of ADAM12 as bait, and identified a protein that we designated Eve-1. Two cDNAs were cloned and characterized. They encode alternatively spliced isoforms of Eve-1, called Eve-1a and Eve-1b, that have four and five tandem Src homology 3 (SH3) domains in the carboxyl-terminal region, respectively, and seven proline-rich SH3 domain binding motifs in the amino-terminal region. The short forms of Eve-1, Eve-1c and Eve-1d, translated at Met-371 are human counterparts of mouse Sh3d19. Northern blot analysis demonstrated that Eve-1 is abundantly expressed in skeletal muscle and heart. Western blot analysis revealed the dominant production of Eve-1c in human cancer cell lines. Knockdown of Eve-1 by small interfering RNA in HT1080 cells reduced the shedding of proHB-EGF induced by angiotensin II and 12-O-tetradecanoylphorbol-13-acetate, as well as the shedding of pro-transforming growth factor-alpha, promphiregulin, and proepiregulin by 12-O-tetradecanoylphorbol-13-acetate, suggesting that Eve-1 plays a role in positively regulating the activity of ADAMs in the signaling of EGFR-ligand shedding.

  17. Activation of p38 Mitogen-Activated Protein Kinase Promotes Epidermal Growth Factor Receptor Internalization

    PubMed Central

    Vergarajauregui, Silvia; Miguel, Anitza San; Puertollano, Rosa

    2006-01-01

    Endocytic trafficking plays an important role in the regulation of the epidermal growth factor receptor (EGFR). To address if cellular kinases regulate EGFR internalization, we used anisomycin, a potent activator of kinase cascades in mammalian cells, especially the stress-activated mitogen-activated protein (MAP) kinase subtypes. Here, we report that activation of p38 MAP kinase by anisomycin is sufficient to induce internalization of EGFR. Anisomycin and EGF employ different mechanisms to promote EGFR endocytosis as anisomycin-induced internalization does not require tyrosine kinase activity or ubiquitination of the receptor. In addition, anisomycin treatment did not result in delivery and degradation of EGFR at lysosomes. Incubation with a specific inhibitor of p38, or depletion of endogenous p38 by small interfering RNAs, abolished anisomycin-induced internalization of EGFR while having no effect on transferrin endocytosis, indicating that the effect of p38 activation on EGFR endocytosis is specific. Interestingly, inhibition of p38 activation also abolished endocytosis of EGFR induced by UV radiation. Our results reveal a novel role for p38 in the regulation of EGFR endocytosis and suggest that stimulation of EGFR internalization by p38 might represent a general mechanism to prevent generation of proliferative or anti-apoptotic signals under stress conditions. PMID:16683917

  18. Two domains of the epidermal growth factor receptor are involved in cytoskeletal interactions

    SciTech Connect

    Song Wei; Wu Jing; Ge Gaoxiang; Lin Qishui

    2008-06-13

    Epidermal growth factor receptor can interact directly with F-actin through an actin-binding domain. In the present study, a mutant EGFR, lacking a previously identified actin-binding domain (ABD 1), was still able to bind elements of the cytoskeleton. A second EGFR actin-binding domain (ABD 2) was identified in the region of the receptor that includes Tyr-1148 by a yeast two-hybrid assay. GST fusion proteins comprising ABD 1 or ABD 2 bound actin in vitro and competed for actin-binding with the full-length EGFR. EGFR binding to actin was also studied in intact cells using fluorescence resonance energy transfer (FRET). The localization of the EGFR/actin-binding complex changed after EGF stimulation. Fusion proteins containing mutations in ABD1 or ABD2 did not display a FRET signal. The results lead to the conclusion that the interaction between ABD1 and ABD2 and actin during EGF-induced signal transduction, and thus between EGFR and actin, are important in cell activation.

  19. Constitutive asymmetric dimerization drives oncogenic activation of epidermal growth factor receptor carboxyl-terminal deletion mutants

    PubMed Central

    Park, Angela K.J.; Francis, Joshua M.; Park, Woong-Yang; Park, Joon-Oh; Cho, Jeonghee

    2015-01-01

    Genomic alterations targeting the Epidermal Growth Factor Receptor (EGFR) gene have been strongly associated with cancer pathogenesis. The clinical effectiveness of EGFR targeted therapies, including small molecules directed against the kinase domain such as gefitinib, erlotinib and afatinib, have been proven successful in treating non-small cell lung cancer patients with tumors harboring EGFR kinase domain mutations. Recent large-scale genomic studies in glioblastoma and lung cancer have identified an additional class of oncogenic mutations caused by the intragenic deletion of carboxy-terminal coding regions. Here, we report that combinations of exonic deletions of exon 25 to 28 lead to the oncogenic activation of EGF receptor in the absence of ligand and consequent cellular transformation, indicating a significant role of C-terminal domain in modulating EGFR activation. Furthermore, we show that the oncogenic activity of the resulting C-terminal deletion mutants are efficiently inhibited by EGFR-targeted drugs including erlotinib, afatinib, dacomitinib as well as cetuximab, expanding the therapeutic rationale of cancer genome-based EGFR targeted approaches. Finally, in vivo and in vitro preclinical studies demonstrate that constitutive asymmetric dimerization in mutant EGFR is a key mechanism for oncogenic activation and tumorigenesis by C-terminal deletion mutants. Therefore, our data provide compelling evidence for oncogenic activation of C-terminal deletion mutants at the molecular level and we propose that C-terminal deletion status of EGFR can be considered as a potential genomic marker for EGFR-targeted therapy. PMID:25826094

  20. The Influence of Adnectin Binding on the Extracellular Domain of Epidermal Growth Factor Receptor

    NASA Astrophysics Data System (ADS)

    Iacob, Roxana E.; Chen, Guodong; Ahn, Joomi; Houel, Stephane; Wei, Hui; Mo, Jingjie; Tao, Li; Cohen, Daniel; Xie, Dianlin; Lin, Zheng; Morin, Paul E.; Doyle, Michael L.; Tymiak, Adrienne A.; Engen, John R.

    2014-12-01

    The precise and unambiguous elucidation and characterization of interactions between a high affinity recognition entity and its cognate protein provides important insights for the design and development of drugs with optimized properties and efficacy. In oncology, one important target protein has been shown to be the epidermal growth factor receptor (EGFR) through the development of therapeutic anticancer antibodies that are selective inhibitors of EGFR activity. More recently, smaller protein derived from the 10th type III domain of human fibronectin termed an adnectin has also been shown to inhibit EGFR in clinical studies. The mechanism of EGFR inhibition by either an adnectin or an antibody results from specific binding of the high affinity protein to the extracellular portion of EGFR (exEGFR) in a manner that prevents phosphorylation of the intracellular kinase domain of the receptor and thereby blocks intracellular signaling. Here, the structural changes induced upon binding were studied by probing the solution conformations of full length exEGFR alone and bound to a cognate adnectin through hydrogen/deuterium exchange mass spectrometry (HDX MS). The effects of binding in solution were identified and compared with the structure of a bound complex determined by X-ray crystallography.

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

    PubMed

    Faria, Jerusa A Q A; de Andrade, Carolina; Goes, Alfredo M; Rodrigues, Michele A; Gomes, Dawidson A

    2016-09-01

    The epidermal growth factor receptor (EGFR) is activated through binding to specific ligands and generates signals for proliferation, differentiation, migration, and cell survival. Recent data show the role of nuclear EGFR in tumors. Although many EGFR ligands are upregulated in cancers, little is known about their effects on EGFR nuclear translocation. We have compared the effects of six EGFR ligands (EGF, HB-EGF, TGF-α, β-Cellulin, amphiregulin, and epiregulin) on nuclear translocation of EGFR, receptor phosphorylation, migration, and proliferation. Cell fractionation and confocal immunofluorescence detected EGFR in the nucleus after EGF, HB-EGF, TGF-α and β-Cellulin stimulation in a dose-dependent manner. In contrast, amphiregulin and epiregulin did not generate nuclear translocation of EGFR. EGF, HB-EGF, TGF-α and β-Cellulin showed correlations between a higher rate of wound closure and increased phosphorylation of residues in the carboxy-terminus of EGFR, compared to amphiregulin and epiregulin. The data indicate that EGFR is translocated to the nucleus after stimulation with EGF, HB-EGF, TGF-α and β-Cellulin, and that these ligands are related to increased phosphorylation of EGFR tyrosine residues, inducing migration of SkHep-1 cells. PMID:27462018

  2. Physicochemical properties of epidermal growth factor receptor inhibitors and development of a nanoliposomal formulation of gefitinib.

    PubMed

    Trummer, Brian J; Iyer, Vandana; Balu-Iyer, Sathy V; O'Connor, Robert; Straubinger, Robert M

    2012-08-01

    Inhibitors of epidermal growth factor (EGF) receptor (EGFR) tyrosine kinases show efficacy in cancers that are highly addicted to nonmutated EGF signaling, but off-target effects limit therapy. Carrier-based formulations could reduce drug deposition in normal tissues, enhance tumor deposition, and reduce free drug concentrations, thereby reducing the side effects. Therefore, the feasibility of developing nanoliposomal formulations of EGFR inhibitors was investigated. Gefitinib and erlotinib fluorescence was characterized as a tool for formulation development. Peak excitation was 345 nm and peak emission was 385-465 nm, depending upon the environment polarity. Emission was negligible in water but intense in nonpolar solvents, membranes, or bound to serum proteins. Cellular uptake and distribution could also be imaged by fluorescence in drug-resistant tumor spheroids. Gefitinib fluorescence characteristics enabled facile optimization of formulations. Although 4-6 mol % gefitinib could be incorporated in the liposome bilayer, 40-60 mol % could be encapsulated in stable, remote-loaded liposomes consisting of distearoylphosphatidylcholine-polyethylene glycol-distereoylphosphatidylethanolamine-cholesterol (9:1:5 mol:mol:mol). Drug leakage in serum, monitored by fluorescence, was minimal over 24 h at 37°C. The results provide both promising lead formulations as well as novel tools for evaluating new formulations of structurally similar receptor tyrosine kinase inhibitors and their cellular uptake and tissue biodistribution.

  3. Selectivity of phospholipase C phosphorylation by the epidermal growth factor receptor, the insulin receptor, and their cytoplasmic domains.

    PubMed Central

    Nishibe, S; Wahl, M I; Wedegaertner, P B; Kim, J W; Rhee, S G; Carpenter, G; Kim, J J

    1990-01-01

    Phosphatidylinositol-specific phospholipase C isozyme gamma (PLC-gamma, Mr 145,000) is an excellent substrate for the epidermal growth factor (EGF) receptor both in vivo and in vitro. PLC-beta-1, another PLC isozyme, is a poor substrate for the EGF receptor. We examined the relative phosphorylation of PLC-gamma and PLC-beta-1 by the 170-kDa native EGF receptor molecule, the 66-kDa cytoplasmic kinase domain of the EGF receptor (Arg647-Ala1186), the alpha 2 beta 2 native insulin receptor, and the 48-kDa cytoplasmic kinase domain of the insulin receptor beta subunit (Gly947-Ser1343). Similar to the intact EGF receptor, the cytoplasmic kinase domain of the EGF receptor preferentially phosphorylated PLC-gamma. High-performance liquid chromatographic comparison of tryptic phosphopeptides from PLC-gamma phosphorylated by both forms of the EGF receptor kinase indicated similar patterns of multiple tyrosine phosphorylations. These results imply that substrate selectivity, at least in terms of PLC isozymes, is independent of the extracellular ligand-binding and membrane anchor domains of the EGF receptor. In comparison, neither the intact insulin receptor nor the beta-chain kinase domain was able to phosphorylate PLC-gamma to a significant extent. Also, insulin failed to stimulate the phosphorylation of PLC-gamma in NIH 3T3/HIR cells, which overexpress the human insulin receptor. Thus PLC-gamma is not a phosphorylation substrate for the insulin receptor in vitro or in the intact cell. Images PMID:2153302

  4. Human Epidermal Growth Factor Receptor Expression in Colorectal Cancer and Its Relationship with Clinicopathological Characteristics

    PubMed Central

    Torabizadeh, Zhila; Nosrati, Anahita; Tahvildari, Shadi

    2016-01-01

    BACKGROUND Some recent studies reported human epidermal growth factor receptor (HER-2/neu) as a marker that can be used in immunological studies of colorectal carcinoma for predicting the prognosis and the treatment. Therefore, we aimed to investigate the frequency of HER-2 expression in patients with colorectal cancer, and explore the relationship between clinicopathological prognostic factors and its expression based on immunohistochemical analysis. METHODS This study included 50 patients with a histologically proven diagnosis of colorectal carcinoma who received surgery at Imam Khomeini Hospital affiliated to Mazandaran University of Medical Sciences. First, HER-2/neu protein expressions were detected by immunohistochemistry and then the data extracted from recorded files. RESULTS The median age of the patients was 60.2±13.9 years (range: 25-93 years). There was no significant relationship between size of tumor, age, sex, lymph node metastases, distant metastasis, differentiation, and stage of the disease with positive expression of HER-2 in this study. CONCLUSION No significant relationship between expression of HER-2 and clinicopathological prognostic factors was found in our study. Further comprehensive and prospective trial with standard method to evaluate the role of HER-2 expression among patients with colorectal cancer is needed. PMID:26933478

  5. Human Epidermal Growth Factor Receptor Expression in Colorectal Cancer and Its Relationship with Clinicopathological Characteristics.

    PubMed

    Torabizadeh, Zhila; Nosrati, Anahita; Tahvildari, Shadi

    2016-01-01

    BACKGROUND Some recent studies reported human epidermal growth factor receptor (HER-2/neu) as a marker that can be used in immunological studies of colorectal carcinoma for predicting the prognosis and the treatment. Therefore, we aimed to investigate the frequency of HER-2 expression in patients with colorectal cancer, and explore the relationship between clinicopathological prognostic factors and its expression based on immunohistochemical analysis. METHODS This study included 50 patients with a histologically proven diagnosis of colorectal carcinoma who received surgery at Imam Khomeini Hospital affiliated to Mazandaran University of Medical Sciences. First, HER-2/neu protein expressions were detected by immunohistochemistry and then the data extracted from recorded files. RESULTS The median age of the patients was 60.2±13.9 years (range: 25-93 years). There was no significant relationship between size of tumor, age, sex, lymph node metastases, distant metastasis, differentiation, and stage of the disease with positive expression of HER-2 in this study. CONCLUSION No significant relationship between expression of HER-2 and clinicopathological prognostic factors was found in our study. Further comprehensive and prospective trial with standard method to evaluate the role of HER-2 expression among patients with colorectal cancer is needed. PMID:26933478

  6. Direct interaction of avermectin with epidermal growth factor receptor mediates the penetration resistance in Drosophila larvae

    PubMed Central

    Chen, Li-Ping; Wang, Pan; Sun, Ying-Jian; Wu, Yi-Jun

    2016-01-01

    With the widespread use of avermectins (AVMs) for managing parasitic and agricultural pests, the resistance of worms and insects to AVMs has emerged as a serious threat to human health and agriculture worldwide. The reduced penetration of AVMs is one of the main reasons for the development of the resistance to the chemicals. However, the detailed molecular mechanisms remain elusive. Here, we use the larvae of Drosophila melanogaster as the model organism to explore the molecular mechanisms underlying the development of penetration resistance to AVMs. We clearly show that the chitin layer is thickened and the efflux transporter P-glycoprotein (P-gp) is overexpressed in the AVM-resistant larvae epidermis. We reveal that the activation of the transcription factor Relish by the over-activated epidermal growth factor receptor (EGFR)/AKT/ERK pathway induces the overexpression of the chitin synthases DmeCHS1/2 and P-gp in the resistant larvae. Interestingly, we discover for the first time, to the best of our knowledge, that AVM directly interacts with EGFR and leads to the activation of the EGFR/AKT/ERK pathway, which activates the transcription factor Relish and induces the overexpression of DmeCHS1/2 and P-gp. These findings provide new insights into the molecular mechanisms underlying the development of penetration resistance to drugs. PMID:27249340

  7. Epidermal growth factor receptor inhibitor protects against abdominal aortic aneurysm in a mouse model.

    PubMed

    Obama, Takashi; Tsuji, Toshiyuki; Kobayashi, Tomonori; Fukuda, Yamato; Takayanagi, Takehiko; Taro, Yoshinori; Kawai, Tatsuo; Forrester, Steven J; Elliott, Katherine J; Choi, Eric; Daugherty, Alan; Rizzo, Victor; Eguchi, Satoru

    2015-05-01

    Angiotensin II (Ang II) has been implicated in the development of abdominal aortic aneurysm (AAA). In vascular smooth muscle cells (VSMC), Ang II activates epidermal growth factor receptor (EGFR) mediating growth promotion. We hypothesized that inhibition of EGFR prevents Ang II-dependent AAA. C57BL/6 mice were co-treated with Ang II and β-aminopropionitrile (BAPN) to induce AAA with or without treatment with EGFR inhibitor, erlotinib. Without erlotinib, 64.3% of mice were dead due to aortic rupture. All surviving mice had AAA associated with EGFR activation. Erlotinib-treated mice did not die and developed far fewer AAA. The maximum diameters of abdominal aortas were significantly shorter with erlotinib treatment. In contrast, both erlotinib-treated and non-treated mice developed hypertension. The erlotinib treatment of abdominal aorta was associated with lack of EGFR activation, endoplasmic reticulum (ER) stress, oxidative stress, interleukin-6 induction and matrix deposition. EGFR activation in AAA was also observed in humans. In conclusion, EGFR inhibition appears to protect mice from AAA formation induced by Ang II plus BAPN. The mechanism seems to involve suppression of vascular EGFR and ER stress. PMID:25531554

  8. Radiosensitisation of U87MG brain tumours by anti-epidermal growth factor receptor monoclonal antibodies

    PubMed Central

    Diaz Miqueli, A; Rolff, J; Lemm, M; Fichtner, I; Perez, R; Montero, E

    2009-01-01

    As epidermal growth factor receptor (EGFR) has been reported to be a radiation response modulator, HER inhibitors are regarded to act as potential radiosensitisers. Our study examined the role of nimotuzumab and cetuximab both, the two monoclonal antibodies (mAbs) to EGFR, as radiosensitisers in a murine glioma model in vivo. Co-administration of both the antibodies with radiation increased the radiosensitivity of U87MG, resulting in a significant delay of subcutaneous (s.c.) tumour growth. Furthermore, the addition of antibodies to the radiation decreased brain tumour sizes and is inhibited by 40–80% the increased tumour cell invasion provoked by radiotherapy, although promoted tumour cell apoptosis. Whereas nimotuzumab led to a reduction in the size of tumour blood vessels and proliferating cells in s.c. tumours, cetuximab had no significant antiangiogenic nor antiproliferative activity. In contrast, cetuximab induced a more marked inhibition of EGFR downstream signalling compared with nimotuzumab. Moreover, both antibodies reduced the total number of radioresistant CD133+ cancer stem cells (CSCs). These results were encouraging, and showed the superiority of combined treatment of mAbs to EGFR and radiation over each single therapy against glioblastoma multiforme (GBM), confirming the role of these drugs as radiosensitisers in human GBM. In addition, we first showed the ability of mAb specifics against EGFR to target radioresistant glioma CSC, supporting the potential use in patients. PMID:19293809

  9. Inhibition of epidermal growth factor receptor tyrosine kinase ameliorates collagen-induced arthritis.

    PubMed

    Swanson, Christina D; Akama-Garren, Elliot H; Stein, Emily A; Petralia, Jacob D; Ruiz, Pedro J; Edalati, Abdolhossein; Lindstrom, Tamsin M; Robinson, William H

    2012-04-01

    Rheumatoid arthritis (RA) is an autoimmune synovitis characterized by the formation of pannus and the destruction of cartilage and bone in the synovial joints. Although immune cells, which infiltrate the pannus and promote inflammation, play a prominent role in the pathogenesis of RA, other cell types also contribute. Proliferation of synovial fibroblasts, for example, underlies the formation of the pannus, while proliferation of endothelial cells results in neovascularization, which supports the growth of the pannus by supplying it with nutrients and oxygen. The synovial fibroblasts also promote inflammation in the synovium by producing cytokines and chemokines. Finally, osteoclasts cause the destruction of bone. In this study, we show that erlotinib, an inhibitor of the tyrosine kinase epidermal growth factor receptor (EGFR), reduces the severity of established collagen-induced arthritis, a mouse model of RA, and that it does so by targeting synovial fibroblasts, endothelial cells, and osteoclasts. Erlotinib-induced attenuation of autoimmune arthritis was associated with a reduction in number of osteoclasts and blood vessels, and erlotinib inhibited the formation of murine osteoclasts and the proliferation of human endothelial cells in vitro. Erlotinib also inhibited the proliferation and cytokine production of human synovial fibroblasts in vitro. Moreover, EGFR was highly expressed and activated in the synovium of mice with collagen-induced arthritis and patients with RA. Taken together, these findings suggest that EGFR plays a central role in the pathogenesis of RA and that EGFR inhibition may provide benefits in the treatment of RA.

  10. Transcriptional activation of the human epidermal growth factor receptor promoter by human p53.

    PubMed Central

    Ludes-Meyers, J H; Subler, M A; Shivakumar, C V; Munoz, R M; Jiang, P; Bigger, J E; Brown, D R; Deb, S P; Deb, S

    1996-01-01

    The human epidermal growth factor receptor (EGFR) promoter is activated by both wild-type and tumor-derived mutant p53. In this communication, we demonstrate that EGFR promoter sequence requirements for transactivation by wild-type and mutant p53 are different. Transient-expression assays with EGFR promoter deletions identified a wild-type human p53 response element, 5'-AGCTAGACGTCCGGGCAGCCCCCGGCG -3', from positions --265 to --239. Electrophoretic mobility shift analysis and DNase I footprinting assays indicated that wild-type p53 binds sequence specifically to the response element. Using circularly permuted DNA fragments containing the p53-binding site, we show that wild-type p53 binding induces DNA bending at this site. We further show that the EGFR promoter is also activated by tumor-derived p53 mutants p53-143A, p53-175H, p53-248W, p53-273H, and p53-281G. However, the transactivation by mutant p53 does not require the wild-type p53-binding site. The minimal EGFR promoter from positions --104 to --20 which does not contain the wild-type p53-binding site is transactivated by the p53 mutants but not by the wild-type protein, showing a difference in the mechanism of transactivation by wild-type and mutant p53. Transactivation of the EGFR promoter by p53 may represent a novel mechanism of cell growth regulation. PMID:8887630

  11. Epidermal growth factor receptor inhibitor protects against abdominal aortic aneurysm in a mouse model.

    PubMed

    Obama, Takashi; Tsuji, Toshiyuki; Kobayashi, Tomonori; Fukuda, Yamato; Takayanagi, Takehiko; Taro, Yoshinori; Kawai, Tatsuo; Forrester, Steven J; Elliott, Katherine J; Choi, Eric; Daugherty, Alan; Rizzo, Victor; Eguchi, Satoru

    2015-05-01

    Angiotensin II (Ang II) has been implicated in the development of abdominal aortic aneurysm (AAA). In vascular smooth muscle cells (VSMC), Ang II activates epidermal growth factor receptor (EGFR) mediating growth promotion. We hypothesized that inhibition of EGFR prevents Ang II-dependent AAA. C57BL/6 mice were co-treated with Ang II and β-aminopropionitrile (BAPN) to induce AAA with or without treatment with EGFR inhibitor, erlotinib. Without erlotinib, 64.3% of mice were dead due to aortic rupture. All surviving mice had AAA associated with EGFR activation. Erlotinib-treated mice did not die and developed far fewer AAA. The maximum diameters of abdominal aortas were significantly shorter with erlotinib treatment. In contrast, both erlotinib-treated and non-treated mice developed hypertension. The erlotinib treatment of abdominal aorta was associated with lack of EGFR activation, endoplasmic reticulum (ER) stress, oxidative stress, interleukin-6 induction and matrix deposition. EGFR activation in AAA was also observed in humans. In conclusion, EGFR inhibition appears to protect mice from AAA formation induced by Ang II plus BAPN. The mechanism seems to involve suppression of vascular EGFR and ER stress.

  12. Reformulating Tylocrebrine in Epidermal Growth Factor Receptor Targeted Polymeric Nanoparticles Improves Its Therapeutic Index

    PubMed Central

    2015-01-01

    Several promising anticancer drug candidates have been sidelined owing to their poor physicochemical properties or unfavorable pharmacokinetics, resulting in high overall cost of drug discovery and development. Use of alternative formulation strategies that alleviate these issues can help advance new molecules to the clinic at a significantly lower cost. Tylocrebrine is a natural product with potent anticancer activity. Its clinical trial was discontinued following the discovery of severe central nervous system toxicities. To improve the safety and potency of tylocrebrine, we formulated the drug in polymeric nanoparticles targeted to the epidermal growth factor receptor (EGFR) overexpressed on several types of tumors. Through in vitro studies in different cancer cell lines, we found that EGFR targeted nanoparticles were significantly more effective in killing tumor cells than the free drug. In vivo pharmacokinetic studies revealed that encapsulation in nanoparticles resulted in lower brain penetration and enhanced tumor accumulation of the drug. Further, targeted nanoparticles were characterized by significantly enhanced tumor growth inhibitory activity in a mouse xenograft model of epidermoid cancer. These results suggest that the therapeutic index of drugs that were previously considered unusable could be significantly improved by reformulation. Application of novel formulation strategies to previously abandoned drugs provides an opportunity to advance new molecules to the clinic at a lower cost. This can significantly increase the repertoire of treatment options available to cancer patients. PMID:26065924

  13. Gene silencing for epidermal growth factor receptor variant III induces cell-specific cytotoxicity

    PubMed Central

    Yamoutpour, Farnaz; Bodempudi, Vidya; Park, Shay E.; Pan, Weihong; Mauzy, Mary Jean; Kratzke, Robert A.; Dudek, Arkadiusz; Potter, David A.; Woo, Richard A.; O’Rourke, Donald M.; Tindall, Donald J.; Farassati, Faris

    2009-01-01

    Epidermal growth factor receptor variant III (EGFRvIII) is a constitutively active mutant form of EGFR that is expressed in 40% to 50% of gliomas and several other malignancies. Here, we describe the therapeutic effects of silencing EGFRvIII on glioma cell lines in vitro and in vivo. A small interfering RNA molecule against EGFRvIII was introduced into EGFRvIII-expressing glioma cells (U87Δ) by electroporation resulting in complete inhibition of expression of EGFRvIII as early as 48 h post-treatment. During EGFRvIII silencing, a decrease in the proliferation and invasiveness of U87Δ cells was accompanied by an increase in apoptosis (P < 0.05). Notably, EGFRvIII silencing inhibited the signal transduction machinery downstream of EGFRvIII as evidenced by decreases in the activated levels of Ras and extracellular signal-regulated kinase. A lentivirus capable of expressing anti-EGFRvIII short hairpin RNA was also able to achieve progressive silencing of EGFRvIII in U87Δ cells in addition to inhibiting cell proliferation, invasiveness, and colony formation in a significant manner (P < 0.05). Silencing EGFRvIII in U87Δ cultures with this virus reduced the expression of factors involved in epithelial-mesenchymal transition including N-cadherin, β-catenin, Snail, Slug, and paxillin but not E-cadherin. The anti-EGFRvIII lentivirus also affected the cell cycle progression of U87Δ cells with a decrease in G1 and increase in S and G2 fractions. In an in vivo model, tumor growth was completely inhibited in severe combined immunodeficient mice (n = 10) injected s.c. with U87Δ cells treated with the anti-EGFRvIII lentivirus (P = 0.005). We conclude that gene specific silencing of EGFRvIII is a promising strategy for treating cancers that contain this mutated receptor. PMID:19001441

  14. Early growth response-1 suppresses epidermal growth factor receptor-mediated airway hyperresponsiveness and lung remodeling in mice.

    PubMed

    Kramer, Elizabeth L; Mushaben, Elizabeth M; Pastura, Patricia A; Acciani, Thomas H; Deutsch, Gail H; Khurana Hershey, Gurjit K; Korfhagen, Thomas R; Hardie, William D; Whitsett, Jeffrey A; Le Cras, Timothy D

    2009-10-01

    Transforming growth factor (TGF)-alpha and its receptor, the epidermal growth factor receptor, are induced after lung injury and are associated with remodeling in chronic pulmonary diseases, such as pulmonary fibrosis and asthma. Expression of TGF-alpha in the lungs of adult mice causes fibrosis, pleural thickening, and pulmonary hypertension, in addition to increased expression of a transcription factor, early growth response-1 (Egr-1). Egr-1 was increased in airway smooth muscle (ASM) and the vascular adventitia in the lungs of mice conditionally expressing TGF-alpha in airway epithelium (Clara cell secretory protein-rtTA(+/-)/[tetO](7)-TGF-alpha(+/-)). The goal of this study was to determine the role of Egr-1 in TGF-alpha-induced lung disease. To accomplish this, TGF-alpha-transgenic mice were crossed to Egr-1 knockout (Egr-1(ko/ko)) mice. The lack of Egr-1 markedly increased the severity of TGF-alpha-induced pulmonary disease, dramatically enhancing airway muscularization, increasing pulmonary fibrosis, and causing greater airway hyperresponsiveness to methacholine. Smooth muscle hyperplasia, not hypertrophy, caused the ASM thickening in the absence of Egr-1. No detectable increases in pulmonary inflammation were found. In addition to the airway remodeling disease, vascular remodeling and pulmonary hypertension were also more severe in Egr-1(ko/ko) mice. Thus, Egr-1 acts to suppress epidermal growth factor receptor-mediated airway and vascular muscularization, fibrosis, and airway hyperresponsiveness in the absence of inflammation. This provides a unique model to study the processes causing pulmonary fibrosis and ASM thickening without the complicating effects of inflammation.

  15. WT1 suppresses synthesis of the epidermal growth factor receptor and induces apoptosis.

    PubMed Central

    Englert, C; Hou, X; Maheswaran, S; Bennett, P; Ngwu, C; Re, G G; Garvin, A J; Rosner, M R; Haber, D A

    1995-01-01

    The Wilms tumor suppressor gene WT1 encodes a developmentally regulated transcription factor that is mutated in a subset of embryonal tumors. To test its functional properties, we developed osteosarcoma cell lines expressing WT1 under an inducible tetracycline-regulated promoter. Induction of WT1 resulted in programmed cell death. This effect, which was differentially mediated by the alternative splicing variants of WT1, was independent of p53. WT1-mediated apoptosis was associated with reduced synthesis of the epidermal growth factor receptor (EGFR), but not of other postulated WT1-target genes, and it was abrogated by constitutive expression of EGFR. WT1 repressed transcription from the EGFR promoter, binding to two TC-rich repeat sequences. In the developing kidney, EGFR expression in renal precursor cells declined with the onset of WT1 expression. Repression of EGFR and induction of apoptosis by mechanism that may contribute to its critical role in normal kidney development and to the immortalization of tumor cells with inactivated WT1 alleles. Images PMID:7588596

  16. Epidermal Growth Factor Receptor Mutation Enhances Expression of Cadherin-5 in Lung Cancer Cells

    PubMed Central

    Hung, Ming-Szu; Chen, I-Chuan; Lung, Jr-Hau; Lin, Paul-Yann; Li, Ya-Chin; Tsai, Ying-Huang

    2016-01-01

    Epidermal growth factor receptor (EGFR) activation has been shown to play a critical role in tumor angiogenesis. In this study, we investigate the correlation between EGFR mutations and cadherin-5 (CDH5), which is an angiogenic factor, in lung cancer cells. Increased expression CDH5 is observed in lung cancer cells with EGFR mutations. Stable lung cancer cell lines expressing mutant (exon 19 deletion E746-A750, and exon 21 missense mutation L858R) and wild type EGFR genes are established. A significantly higher expression of CDH5 is observed in exon 19 deletion stable lung cancer cells and mouse xenografts. Further studies show that expression of CDH5 is decreased after the inhibition of EGFR and downstream Akt pathways in lung cancer cells with EGFR mutation. In addition, mutant EGFR genes potentiates angiogenesis in lung cancer cells, which is inhibited by CDH5 siRNA, and potentiates migration and invasion in lung cancer cells. Our study shows that mutant EGFR genes are associated with overexpression of CDH5 through increased phosphorylation of EGFR and downstream Akt pathways. Our result may provide an insight into the association of mutant EGFR and CDH5 expression in lung cancer and aid further development of target therapy for NSCLC in the future. PMID:27362942

  17. Epidermal Growth Factor Receptor Mutation Enhances Expression of Cadherin-5 in Lung Cancer Cells.

    PubMed

    Hung, Ming-Szu; Chen, I-Chuan; Lung, Jr-Hau; Lin, Paul-Yann; Li, Ya-Chin; Tsai, Ying-Huang

    2016-01-01

    Epidermal growth factor receptor (EGFR) activation has been shown to play a critical role in tumor angiogenesis. In this study, we investigate the correlation between EGFR mutations and cadherin-5 (CDH5), which is an angiogenic factor, in lung cancer cells. Increased expression CDH5 is observed in lung cancer cells with EGFR mutations. Stable lung cancer cell lines expressing mutant (exon 19 deletion E746-A750, and exon 21 missense mutation L858R) and wild type EGFR genes are established. A significantly higher expression of CDH5 is observed in exon 19 deletion stable lung cancer cells and mouse xenografts. Further studies show that expression of CDH5 is decreased after the inhibition of EGFR and downstream Akt pathways in lung cancer cells with EGFR mutation. In addition, mutant EGFR genes potentiates angiogenesis in lung cancer cells, which is inhibited by CDH5 siRNA, and potentiates migration and invasion in lung cancer cells. Our study shows that mutant EGFR genes are associated with overexpression of CDH5 through increased phosphorylation of EGFR and downstream Akt pathways. Our result may provide an insight into the association of mutant EGFR and CDH5 expression in lung cancer and aid further development of target therapy for NSCLC in the future.

  18. Construction of an immunotoxin by linking a monoclonal antibody against the human epidermal growth factor receptor and a hemolytic toxin.

    PubMed

    Avila, Ana D; Calderón, Carlos F; Pérez, Rita M; Pons, Carmen; Pereda, Celia M; Ortiz, Ana R

    2007-01-01

    Hybrid molecules obtained through conjugation of monoclonal antibodies and toxins constitute an approach under exploration to generate potential agents for the treatment of cancer and other diseases. A frequently employed toxic component in the construction of such immunotoxins is ricin, a plant toxin which inhibits protein synthesis at ribosomal level and so requires to be internalized by the cell. A hemolytic toxin isolated from the sea anemone Stichodactyla helianthus, which is active at the cell membrane level, was linked through a disulfide bond to the anti-epidermal growth factor receptor monoclonal antibody ior egf/r3. The resulting immunotoxin did not exhibit hemolytic activity except under reducing conditions. It was toxic for H125 cells that express the human epidermal growth factor receptor, but non-toxic for U1906 cells that do not express this receptor. PMID:18064354

  19. Epidermal growth factor, transforming growth factor-alpha, and epidermal growth factor receptor expression and localization in the canine endometrium during the estrous cycle and in bitches with pyometra.

    PubMed

    Kida, K; Maezono, Y; Kawate, N; Inaba, T; Hatoya, S; Tamada, H

    2010-01-01

    Gene expression and immunohistochemical localization of epidermal growth factor (EGF), transforming growth factor-alpha (TGF-alpha), and epidermal growth factor receptor (EGF-R) were compared between the endometrium of bitches (Canis familiaris) with pyometra accompanied by cystic endometrial hyperplasia (CEH) and that of healthy bitches at similar stages of the estrous cycle. In normal bitches, endometrial TGF-alpha mRNA levels were highest at proestrus and gradually decreased as the cycle progressed to anestrus. Epidermal growth factor receptor mRNA levels were not significantly affected by the stage of the estrous cycle. Epidermal growth factor mRNA levels were higher at Day 35 of diestrus than at other stages of the estrous cycle (P<0.05). In bitches with pyometra, endometrial TGF-alpha and EGF-R mRNA levels did not differ significantly from those at diestrus in normal bitches, but EGF mRNA levels were lower than those at Day 35 of diestrus in normal bitches (P<0.05). In normal bitches, positive immunohistochemical staining for TGF-alpha, EGF, and EGF-R was mainly present in the glandular and luminal epithelial cells of the endometrium. In contrast, in bitches with pyometra, immunoreactivity for EGF was clearly present in endometrial stromal cells. Inflammatory cells that had infiltrated the endometrial stroma stained strongly for TGF-alpha and EGF-R. Luminal and glandular epithelial cells also stained positive for EGF-R. In conclusion, expression of TGF-alpha by inflammatory cells and a low level of expression and differential localization of EGF may be involved in aberrant growth of endometrial glands and development of CEH. PMID:19853901

  20. Epidermal Growth Factor Receptor in Glioma: Signal Transduction, Neuropathology, Imaging, and Radioresistance1

    PubMed Central

    Hatanpaa, Kimmo J; Burma, Sandeep; Zhao, Dawen; Habib, Amyn A

    2010-01-01

    Aberrant epidermal growth factor receptor (EGFR) signaling is common in cancer. Increased expression of wild type and mutant EGFR is a widespread feature of diverse types of cancer. EGFR signaling in cancer has been the focus of intense investigation for decades primarily for two reasons. First, aberrant EGFR signaling is likely to play an important role in the pathogenesis of cancer, and therefore, the mechanisms of EGFR-mediated oncogenic signaling are of interest. Second, the EGFR signaling system is an attractive target for therapeutic intervention. EGFR gene amplification and overexpression are a particularly striking feature of glioblastoma (GBM), observed in approximately 40% of tumors. GBM is the most common primary malignant tumor of the central nervous system in adults. In approximately 50% of tumors with EGFR amplification, a specific EGFR mutant (EGFRvIII, also known as EGFR type III, de2-7, ΔEGFR) can be detected. This mutant is highly oncogenic and is generated from a deletion of exons 2 to 7 of the EGFR gene, which results in an in-frame deletion of 267 amino acids from the extracellular domain of the receptor. EGFRvIII is unable to bind ligand, and it signals constitutively. Although EGFRvIII has the same signaling domain as the wild type receptor, it seems to generate a distinct set of downstream signals that may contribute to an increased tumorigenicity. In this review, we discuss recent progress in key aspects of EGFR signaling in GBM, focusing on neuropathology, signal transduction, imaging of the EGFR, and the role of the EGFR in mediating resistance to radiation therapy in GBM. PMID:20824044

  1. Immunohistochemical localization of the epidermal growth factor, transforming growth factor alpha, and their receptor in the human mesonephros and metanephros.

    PubMed

    Bernardini, N; Bianchi, F; Lupetti, M; Dolfi, A

    1996-07-01

    The distribution of epidermal growth factor (EGF), transforming growth factor alpha (TGF alpha), and EGF/TGF alpha receptor were studied by means of immunohistochemical methods starting from the very early stages of human embryonic kidney development. Mesonephros and metanephros were examined in order to detect immunoreactive staining in serial sectioned embryos and fetal kidneys. Anti-EGF immunoprecipitates were found in the S-shaped mesonephric vesicles of 6-week old embryos as well as in the mesonephric duct albeit with a lower degree of reactivity. Intense reactivity was observed in the metanephros within the blastemic caps of the same gestational period; the reaction was weaker within the ureteric bud branches. Bowman's capsule, proximal tubules, and collecting ducts were also reactive in the fetal kidney to varying degrees. The distribution of TGF alpha reactivity in the mesonephros was similar to that observed for EGF but with a lower intensity. In contrast, there was no reactivity in the metanephros, at least during the embyronic periods examined. By the 11th week of gestation, an intense reactivity for TGF alpha polipeptide was shown in the fetal kidney at the level of the proximal tubules and Bowman's capsule; distal tubules as well as all urinary structures from the collecting ducts to the pelvis were less reactive. Finally, EGF/TGF alpha receptor reactivity was identified by the 6th week of development, being more intense in the mesonephros at the level of the mesonephric duct cells. In the metanephros, the ureteric bud-derived branches were reactive, whereas most of the blastemic tissue did not stain. By the 11th week, only the collecting ducts and the remaining urinary structures contained reaction products: Reactivity was distributed to the tissues originating from the ureteric bud branching. Taking into account recent advances in knowledge about the biology of growth factors, the hypothesis is proposed that the secretory components (vesicles

  2. A novel epidermal growth factor receptor-signaling platform and its targeted translation in pancreatic cancer.

    PubMed

    Gilmour, Alanna M; Abdulkhalek, Samar; Cheng, Timothy S W; Alghamdi, Farah; Jayanth, Preethi; O'Shea, Leah K; Geen, Olivia; Arvizu, Luis A; Szewczuk, Myron R

    2013-12-01

    Epidermal growth factor (EGF)-induced EGFR tyrosine kinase receptor activation in cancer cell survival responses has become a strategic molecular-targeting clinical therapeutic intent, but the failures of these targeted approaches in the clinical setting demand alternate strategies. Here, we uncover a novel neuraminidase-1 (Neu1) and matrix metalloproteinase-9 (MMP-9) cross-talk in alliance with GPCR neuromedin B, which is essential for EGF-induced receptor activation and cellular signaling. Neu1 and MMP-9 form a complex with EGFR on the cell surface. Tamiflu (oseltamivir phosphate), anti-Neu1 antibodies, broad range MMP inhibitor galardin (GM6001), neuromedin B GPCR specific antagonist BIM-23127, the selective inhibitor of whole heterotrimeric G-protein complex BIM-46174 and MMP-9 specific inhibitor dose-dependently inhibited Neu1 activity associated with EGF stimulated 3T3-hEGFR cells. Tamiflu, anti-Neu1 antibodies and MMP9i attenuated EGFR phosphorylation associated with EGF-stimulated cells. Preclinical data provide the proof-of-evidence for a therapeutic targeting of Neu1 with Tamiflu in impeding human pancreatic cancer growth and metastatic spread in heterotopic xenografts of eGFP-MiaPaCa-2 tumors growing in RAGxCγ double mutant mice. Tamiflu-treated cohort exhibited a reduction of phosphorylation of EGFR-Tyr1173, Stat1-Tyr701, Akt-Thr308, PDGFRα-Tyr754 and NFκBp65-Ser311 but an increase in phospho-Smad2-Ser465/467 and -VEGFR2-Tyr1175 in the tumor lysates from the xenografts of human eGFP-MiaPaCa-2 tumor-bearing mice. The findings identify a novel promising alternate therapeutic treatment of human pancreatic cancer. PMID:23993964

  3. Design and biological activity of epidermal growth factor receptor-targeted peptide doxorubicin conjugate.

    PubMed

    Fan, Mingliang; Yang, Danbo; Liang, Xiaofei; Ao, Junping; Li, Zonghai; Wang, Hongyang; Shi, Bizhi

    2015-03-01

    The nonspecific toxicity of anticancer drug doxorubicin (DOX) toward both tumor and normal cells can result in serious side effects, thereby limiting its clinical applications. In this wok, epidermal growth factor receptor (EGFR) antagonist peptide GE11 was introduced into DOX structure via a disulfide bond which can be cleaved by reduced glutathione (GSH). We have investigated the intracellular delivery and in vitro cytotoxicity of GE11-DOX conjugate and free DOX in high (SMMC-7721) and low (MCF-7) EGFR expressing cancer cell models. GE11-DOX accumulated at higher levels in SMMC-7721 cells than in MCF-7 cells, while the cellular uptake of free DOX was almost the same in both cells. Furthermore, pretreating with anti-EGFR monoclonal antibody reduced intracellular accumulation of GE11-DOX in SMMC-7721, indicating the involvement of EGFR pathway in the transport of conjugate. Our results suggest that GE11-DOX conjugate has the potential to be a therapeutic agent for treating EGFR overexpressing tumor.

  4. The Prognostic and Predictive Role of Epidermal Growth Factor Receptor in Surgical Resected Pancreatic Cancer

    PubMed Central

    Guo, Meng; Luo, Guopei; Liu, Chen; Cheng, He; Lu, Yu; Jin, Kaizhou; Liu, Zuqiang; Long, Jiang; Liu, Liang; Xu, Jin; Huang, Dan; Ni, Quanxing; Yu, Xianjun

    2016-01-01

    The data regarding the prognostic significance of EGFR (epidermal growth factor receptor) expression and adjuvant therapy in patients with resected pancreatic cancer are insufficient. We retrospectively investigated EGFR status in 357 resected PDAC (pancreatic duct adenocarcinoma) patients using tissue immunohistochemistry and validated the possible role of EGFR expression in predicting prognosis. The analysis was based on excluding the multiple confounding parameters. A negative association was found between overall EGFR status and postoperative survival (p = 0.986). Remarkably, adjuvant chemotherapy and radiotherapy were significantly associated with favorable postoperative survival, which prolonged median overall survival (OS) for 5.8 and 10.2 months (p = 0.009 and p = 0.006, respectively). Kaplan–Meier analysis showed that adjuvant chemotherapy correlated with an obvious survival benefit in the EGFR-positive subgroup rather than in the EGFR-negative subgroup. In the subgroup analyses, chemotherapy was highly associated with increased postoperative survival in the EGFR-positive subgroup (p = 0.002), and radiotherapy had a significant survival benefit in the EGFR-negative subgroup (p = 0.029). This study demonstrated that EGFR expression is not correlated with outcome in resected pancreatic cancer patients. Adjuvant chemotherapy and radiotherapy were significantly associated with improved survival in contrary EGFR expressing subgroup. Further studies of EGFR as a potential target for pancreatic cancer treatment are warranted. PMID:27399694

  5. Pertuzumab in human epidermal growth-factor receptor 2-positive breast cancer: clinical and economic considerations

    PubMed Central

    Lamond, Nathan WD; Younis, Tallal

    2014-01-01

    In the absence of specific therapy, the 15%–20% of breast cancers demonstrating human epidermal growth-factor receptor 2 (HER2) protein overexpression and/or gene amplification are characterized by a more aggressive phenotype and poorer prognosis compared to their HER2-negative counterparts. Trastuzumab (Herceptin), the first anti-HER2-targeted therapy, has been associated with improved survival outcomes in HER2-positive breast cancer. However, many patients with early stage disease continue to relapse, and metastatic disease remains incurable. In order to further improve these outcomes, several novel HER2-targeted agents have recently been developed. Pertuzumab (Perjeta), a monoclonal antibody against the HER2 dimerization domain, has also been associated with improved patient outcomes in clinical trials, and has recently been approved in combination with chemotherapy and trastuzumab for neoadjuvant therapy of early stage, HER2-positive breast cancer and first-line treatment of metastatic disease. This review briefly summarizes pertuzumab’s clinical development as well as the published evidence supporting its use, and highlights some of the currently unanswered questions that will influence pertuzumab’s incorporation into clinical practice. PMID:24876795

  6. Interactions of ABCG2 (BCRP) with epidermal growth factor receptor kinase inhibitors developed for molecular imaging.

    PubMed

    Qawasmi, Israa; Shmuel, Miriam; Eyal, Sara

    2014-01-01

    The objective of this study was to investigate in vitro the interactions between novel epidermal growth factor receptor kinase inhibitors (EGFRIs) developed for positron emission tomography (PET) imaging and the major efflux transporter breast cancer resistance protein (BCRP/ABCG2). Seven compounds were evaluated, using the ATPase activity assays and Madin-Darbey canine kidney (MDCK) cells overexpressing BCRP. Five of the tested compounds activated BCRP ATPase to various extent. Overexpression of BCRP conferred resistance to ML04, ML06, methoxy-Br-ML03, and PEG6-ML05 (IC50 values for inhibition of control cell proliferation 2.1 ± 0.6, 2.2 ± 0.7, 1.8 ± 1.2, and 2.8 ± 3.1 μM, respectively, compared to >50 μM in MDCK-BCRP cells). At submicromolar concentrations, none of the EGFRIs significantly inhibited BCRP. Immunoblotting studies indicated that BCRP expression is evident in cell lines utilized for in vivo tumor grafting in small animal PET imaging studies. Thus, the intensity of EGFRIs radioactivity signals previously observed in tumor xenografts reflects an interplay between transporter-mediated distribution of the probe into tumor cells and target binding. Concomitant use of efflux transporter inhibitors may help distinguish between the contribution of efflux transport and EGFR binding to the tissue signal.

  7. Epidermal growth factor receptor expression in different subtypes of oral lichenoid disease

    PubMed Central

    Cortés-Ramírez, Dionisio A.; Rodríguez-Tojo, María J.; Coca-Meneses, Juan C.; Marichalar-Mendia, Xabier

    2014-01-01

    The oral lichenoid disease (OLD) includes different chronic inflammatory processes such as oral lichen planus (OLP) and oral lichenoid lesions (OLL), both entities with controversial diagnosis and malignant potential. Epidermal growth factor receptor (EFGR) is an important oral carcinogenesis biomarker and overexpressed in several oral potentially malignant disorders. Objectives: To analyze the EGFR expression in the OLD to find differences between OLP and OLL, and to correlate it with the main clinical and pathological features. Material and Methods: Forty-four OLD cases were studied and classified according to their clinical (Group C1: only papular lesions / Group C2: papular and other lesions) and histopathological features (Group HT: OLP-typical / Group HC: OLP-compatible) based in previous published criteria. Standard immunohistochemical identification of EGFR protein was performed. Comparative and descriptive statistical analyses were performed. Results: Thirty-five cases (79.5%) showed EGFR overexpression without significant differences between clinical and histopathological groups (p<0.05). Histological groups showed significant differences in the EGFR expression pattern (p=0.016). Conlusions: All OLD samples showed high EGFR expression. The type of clinical lesion was not related with EGFR expression; however, there are differences in the EGFR expression pattern between histological groups that may be related with a different biological profile and malignant risk. Key words:Oral lichenoid disease, oral lichen planus, oral lichenoid lesion, oral carcinogenesis, EGFR. PMID:24880441

  8. KRAS mutational status as a predictor of epidermal growth factor receptor inhibitor efficacy in colorectal cancer.

    PubMed

    Baynes, Roy D; Gansert, Jennifer

    2009-01-01

    Inhibitors of the epidermal growth factor receptor (EGFR) have demonstrated promising potential in the treatment of advanced colorectal cancer. However, a proportion of patients do not respond to therapy with EGFR inhibitors, and therefore, there has been interest in identifying those patients most likely to benefit from therapy with these agents. KRAS, a member of the RAS family of signaling proteins, plays an important role in EGFR-mediated regulation of cellular proliferation and survival. Although there is still some debate regarding the prognostic importance of KRAS mutations in patients with metastatic colorectal cancer, several recent phase 2 and 3 studies have identified the presence of mutations at codons 12 and 13 of KRAS as predictors of poor response to the anti-EGFR monoclonal antibodies panitumumab and cetuximab. Patients with wild-type KRAS were found to have significantly better progression-free survival, overall survival, and/or objective response rate compared with patients harboring KRAS mutations. As a result, there has been growing interest in the development of KRAS mutational status as a biomarker for predicting patient response to EGFR-targeted therapy. Screening colorectal tumors for the absence of KRAS mutations may help identify patients most likely to benefit from anti-EGFR therapies.

  9. Molecular imaging of hepatocellular carcinoma xenografts with epidermal growth factor receptor targeted affibody probes.

    PubMed

    Zhao, Ping; Yang, Xiaoyang; Qi, Shibo; Liu, Hongguang; Jiang, Han; Hoppmann, Susan; Cao, Qizhen; Chua, Mei-Sze; So, Samuel K; Cheng, Zhen

    2013-01-01

    Hepatocellular carcinoma (HCC) is a highly aggressive and lethal cancer. It is typically asymptomatic at the early stage, with only 10%-20% of HCC patients being diagnosed early enough for appropriate surgical treatment. The delayed diagnosis of HCC is associated with limited treatment options and much lower survival rates. Therefore, the early and accurate detection of HCC is crucial to improve its currently dismal prognosis. The epidermal growth factor receptor (EGFR) has been reported to be involved in HCC tumorigenesis and to represent an attractive target for HCC imaging and therapy. In this study, an affibody molecule, Ac-Cys-ZEGFR:1907, targeting the extracellular domain of EGFR, was used for the first time to assess its potential to detect HCC xenografts. By evaluating radio- or fluorescent-labeled Ac-Cys-ZEGFR:1907 as a probe for positron emission tomography (PET) or optical imaging of HCC, subcutaneous EGFR-positive HCC xenografts were found to be successfully imaged by the PET probe. Thus, affibody-based PET imaging of EGFR provides a promising approach for detecting HCC in vivo. PMID:23710458

  10. System theoretical investigation of human epidermal growth factor receptor-mediated signalling

    SciTech Connect

    Zhang, Yi; Shankaran, Harish; Opresko, Lee; Resat, Haluk

    2008-09-01

    The partitioning of biological networks into coupled functional modules is gaining increasing attention in the biological sciences. This approach has the advantage that predicting a system level response does not require a mechanistic description of the internal dynamics of each module. Identification of the input-output characteristics of the network modules and the connectivity between the modules provide the necessary quantitative representation of system dynamics. However, determination of the input-output relationships of the modules is not trivial; it requires the controlled perturbation of module inputs and systematic analysis of experimental data. In this report, we apply a system theoretical analysis approach to derive the causal input-output relationships of the functional module for the human epidermal growth factor receptor (HER) mediated Erk and Akt signaling pathways. Using a library of cell lines expressing varying levels of EGFR and HER2, we show that a transfer function-based representation can be successfully applied to quantitatively characterize information transfer in this system.

  11. Molecular Basis for Redox Activation of Epidermal Growth Factor Receptor Kinase.

    PubMed

    Truong, Thu H; Ung, Peter Man-Un; Palde, Prakash B; Paulsen, Candice E; Schlessinger, Avner; Carroll, Kate S

    2016-07-21

    Epidermal growth factor receptor (EGFR) is a target of signal-derived H2O2, and oxidation of active-site cysteine 797 to sulfenic acid enhances kinase activity. Although a major class of covalent drugs targets C797, nothing is known about its catalytic importance or how S-sulfenylation leads to activation. Here, we report the first detailed functional analysis of C797. In contrast to prior assumptions, mutation of C797 diminishes catalytic efficiency in vitro and cells. The experimentally determined pKa and reactivity of C797 toward H2O2 correspondingly distinguish this residue from the bulk of the cysteinome. Molecular dynamics simulation of reduced versus oxidized EGFR, reinforced by experimental testing, indicates that sulfenylation of C797 allows new electrostatic interactions to be formed with the catalytic loop. Finally, we show that chronic oxidative stress yields an EGFR subpopulation that is refractory to the FDA-approved drug afatinib. Collectively, our data highlight the significance of redox biology to understanding kinase regulation and drug pharmacology. PMID:27427230

  12. Selection of DNA aptamers against epidermal growth factor receptor with high affinity and specificity.

    PubMed

    Wang, Deng-Liang; Song, Yan-Ling; Zhu, Zhi; Li, Xi-Lan; Zou, Yuan; Yang, Hai-Tao; Wang, Jiang-Jie; Yao, Pei-Sen; Pan, Ru-Jun; Yang, Chaoyong James; Kang, De-Zhi

    2014-10-31

    Epidermal growth factor receptor (EGFR/HER1/c-ErbB1), is overexpressed in many solid cancers, such as epidermoid carcinomas, malignant gliomas, etc. EGFR plays roles in proliferation, invasion, angiogenesis and metastasis of malignant cancer cells and is the ideal antigen for clinical applications in cancer detection, imaging and therapy. Aptamers, the output of the systematic evolution of ligands by exponential enrichment (SELEX), are DNA/RNA oligonucleotides which can bind protein and other substances with specificity. RNA aptamers are undesirable due to their instability and high cost of production. Conversely, DNA aptamers have aroused researcher's attention because they are easily synthesized, stable, selective, have high binding affinity and are cost-effective to produce. In this study, we have successfully identified DNA aptamers with high binding affinity and selectivity to EGFR. The aptamer named TuTu22 with Kd 56±7.3nM was chosen from the identified DNA aptamers for further study. Flow cytometry analysis results indicated that the TuTu22 aptamer was able to specifically recognize a variety of cancer cells expressing EGFR but did not bind to the EGFR-negative cells. With all of the aforementioned advantages, the DNA aptamers reported here against cancer biomarker EGFR will facilitate the development of novel targeted cancer detection, imaging and therapy.

  13. Safety experience with IMC-C225, an anti-epidermal growth factor receptor antibody.

    PubMed

    Needle, Michael N

    2002-10-01

    In phase II trials, the anti-epidermal growth factor receptor antibody IMC-C225 did not appear to significantly exacerbate the common toxicities associated with cytotoxic chemotherapy when combined with standard anticancer treatments in patients with colorectal cancer, squamous cell carcinoma of the head and neck, or pancreatic cancer. The most common treatment-related adverse events reported during therapy with IMC-C225 were an acne-like rash and hypersensitivity reactions. The acne-like rash appeared as a sterile, suppurative form of folliculitis, commonly starting on the face, scalp, chest, and upper back. It resolved without scarring once treatment was stopped. Notably, the appearance of acne-like rash, particularly grade 3, was associated with higher treatment responses in patients with refractory colorectal cancer. The hypersensitivity reactions occurred less often than acne-like rash. They responded to standard treatments and were less common after the first dose. In summary, IMC-C225 is generally well tolerated as a single agent and when combined with chemotherapy or radiotherapy and possesses a manageable toxicity profile.

  14. Molecular basis for multimerization in the activation of the epidermal growth factor receptor

    PubMed Central

    Huang, Yongjian; Bharill, Shashank; Karandur, Deepti; Peterson, Sean M; Marita, Morgan; Shi, Xiaojun; Kaliszewski, Megan J; Smith, Adam W; Isacoff, Ehud Y; Kuriyan, John

    2016-01-01

    The epidermal growth factor receptor (EGFR) is activated by dimerization, but activation also generates higher-order multimers, whose nature and function are poorly understood. We have characterized ligand-induced dimerization and multimerization of EGFR using single-molecule analysis, and show that multimerization can be blocked by mutations in a specific region of Domain IV of the extracellular module. These mutations reduce autophosphorylation of the C-terminal tail of EGFR and attenuate phosphorylation of phosphatidyl inositol 3-kinase, which is recruited by EGFR. The catalytic activity of EGFR is switched on through allosteric activation of one kinase domain by another, and we show that if this is restricted to dimers, then sites in the tail that are proximal to the kinase domain are phosphorylated in only one subunit. We propose a structural model for EGFR multimerization through self-association of ligand-bound dimers, in which the majority of kinase domains are activated cooperatively, thereby boosting tail phosphorylation. DOI: http://dx.doi.org/10.7554/eLife.14107.001 PMID:27017828

  15. Autoantibodies to the epidermal growth factor receptor in systemic sclerosis, lupus, and autoimmune mice.

    PubMed

    Planque, Stephanie; Zhou, Yong-Xin; Nishiyama, Yasuhiro; Sinha, Meenal; O'Connor-Mccourt, Maureen; Arnett, Frank C; Paul, Sudhir

    2003-02-01

    Autoantibodies to the recombinant extracellular domain of epidermal growth factor receptor (exEGFR) were detected by ELISA in the serum of Fas-defective old MRL/MpJ/lpr and C3H/HeJ/gld mice, but not young mice from these strains, or nonautoimmune young and old BALB/c, MRL/MpJ/++, and C3H/HeJ/MMTV mice. Compared with control human subjects without autoimmune disease, the frequency of exEGFR-binding autoantibodies was increased in scleroderma (systemic sclerosis) patients and to a lesser extent in lupus patients. Phage autoantibodies (Fv fragments) isolated from a lupus library by selection on a linear epitope of EGFR (residues 294-310) displayed the ability to bind exEGFR. Treatment of EGFR-expressing A431 cells with autoantibodies purified by affinity chromatography on immobilized exEGFR resulted in specific staining of the cells. Short-lived but strong inhibition of cellular DNA synthesis was observed in the presence of the autoantibodies. We concluded that autoantibody responses to EGFR hold the potential of fulfilling a pathogenic role in autoimmune disease.

  16. Dialkoxyquinazolines: Screening Epidermal Growth Factor ReceptorTyrosine Kinase Inhibitors for Potential Tumor Imaging Probes

    SciTech Connect

    VanBrocklin, Henry F.; Lim, John K.; Coffing, Stephanie L.; Hom,Darren L.; Negash, Kitaw; Ono, Michele Y.; Hanrahan, Stephen M.; Taylor,Scott E.; Vanderpoel, Jennifer L.; Slavik, Sarah M.; Morris, Andrew B.; Riese II, David J.

    2005-09-01

    The epidermal growth factor receptor (EGFR), a long-standingdrug development target, is also a desirable target for imaging. Sixteendialkoxyquinazoline analogs, suitable for labeling with positron-emittingisotopes, have been synthesized and evaluated in a battery of in vitroassays to ascertain their chemical and biological properties. Thesecharacteristics provided the basis for the adoption of a selection schemato identify lead molecules for labeling and in vivo evaluation. A newEGFR tyrosine kinase radiometric binding assay revealed that all of thecompounds possessed suitable affinity (IC50 = 0.4 - 51 nM) for the EGFRtyrosine kinase. All of the analogs inhibited ligand-induced EGFRtyrosine phosphorylation (IC50 = 0.8 - 20 nM). The HPLC-estimatedoctanol/water partition coefficients ranged from 2.0-5.5. Four compounds,4-(2'-fluoroanilino)- and 4-(3'-fluoroanilino)-6,7-diethoxyquinazoline aswell as 4-(3'-chloroanilino)- and4-(3'-bromoanilino)-6,7-dimethoxyquinazoline, possess the bestcombination of characteristics that warrant radioisotope labeling andfurther evaluation in tumor-bearing mice.

  17. Role for the epidermal growth factor receptor in chemotherapy-induced alopecia.

    PubMed

    Bichsel, Kyle J; Gogia, Navdeep; Malouff, Timothy; Pena, Zachary; Forney, Eric; Hammiller, Brianna; Watson, Patrice; Hansen, Laura A

    2013-01-01

    Treatment of cancer patients with chemotherapeutics like cyclophosphamide often causes alopecia as a result of premature and aberrant catagen. Because the epidermal growth factor receptor (EGFR) signals anagen hair follicles to enter catagen, we hypothesized that EGFR signaling may be involved in cyclophosphamide-induced alopecia. To test this hypothesis, skin-targeted Egfr mutant mice were generated by crossing floxed Egfr and Keratin 14 promoter-driven Cre recombinase mice. Cyclophosphamide treatment of control mice resulted in alopecia while Egfr mutant skin was resistant to cyclophosphamide-induced alopecia. Egfr mutant skin entered catagen normally, as indicated by dermal papilla condensation and decreased follicular proliferation, but did not progress to telogen as did Egfr wild type follicles. Egfr mutant follicles responded with less proliferation, apoptosis, and fewer p53-positive cells after cyclophosphamide. Treatment of control mice with the EGFR inhibitors erlotinib or gefitinib similarly suppressed alopecia and catagen progression by cyclophosphamide. Secondary analysis of clinical trials utilizing EGFR-targeted therapies and alopecia-inducing chemotherapy also revealed evidence for involvement of EGFR in chemotherapy-induced alopecia. Taken together, our results demonstrated the involvement of EGFR signaling in chemotherapy-induced alopecia, which will help in the design of novel therapeutic regimens to minimize chemotherapy-induced alopecia.

  18. Loss of p53 induces epidermal growth factor receptor promoter activity in normal human keratinocytes

    PubMed Central

    Bheda, A; Creek, KE; Pirisi, L

    2008-01-01

    Overexpression of the epidermal growth factor receptor (EGFR) in human papillomavirus type 16-immortalized human keratinocytes (HKc) is caused by the viral oncoprotein E6, which targets p53 for degradation. We have previously observed that expression of p53 RNAi in normal HKc is associated with an increase in EGFR mRNA and protein. We now report that p53 RNAi induces EGFR promoter activity up to approximately 10-fold in normal HKc, and this effect does not require intact p53 binding sites on the EGFR promoter. Exogenous wild-type p53 inhibits the EGFR promoter at low levels, and activates it at higher concentrations. Yin Yang 1 (YY1), which negatively regulates p53, induces EGFR promoter activity, and this effect is augmented by p53 RNAi. Intact p53 binding sites on the EGFR promoter are not required for activation by YY1. In addition, Sp1 and YY1 synergistically induce the EGFR promoter in normal HKc, indicating that Sp1 may recruit YY1 as a co-activator. Wild-type p53 suppressed Sp1- and YY1-mediated induction of the EGFR promoter. We conclude that acute loss of p53 in normal HKc induces EGFR expression bya mechanism that involves YY1 and Sp1 and does not require p53 binding to the EGFR promoter. PMID:18391986

  19. Epidermal growth factor receptor function is necessary for normal craniofacial development and palate closure.

    PubMed

    Miettinen, P J; Chin, J R; Shum, L; Slavkin, H C; Shuler, C F; Derynck, R; Werb, Z

    1999-05-01

    Craniofacial malformations are among the most frequent congenital birth defects in humans; cleft palate, that is inadequate fusion of the palatal shelves, occurs with an annual incidence of 1 in 700 to 1 in 1,000 live births among individuals of European descent. The secondary palate arises as bilateral outgrowths from the maxillary processes, and its formation depends on the coordinated development of craniofacial structures including the Meckel's cartilage and the mandible. Cleft lip and palate syndromes in humans are associated with polymorphisms in the gene (TGFA) encoding transforming growth factor-alpha (TGF-alpha), an epidermal growth factor receptor (EGFR) ligand made by most epithelia. Here we have characterized craniofacial development in Egfr-deficient (Egfr-/-) mice. Newborn Egfr-/- mice have facial mediolateral defects including narrow, elongated snouts, underdeveloped lower jaw and a high incidence of cleft palate. Palatal shelf explants from Egfr-/- mice fused, but frequently had residual epithelium in the midline. In addition, morphogenesis of Meckel's cartilage was deficient in cultured mandibular processes from Egfr-/- embryos. The secretion of matrix metalloproteinases (MMPs) was diminished in Egfr-/- explants, consistent with the ability of EGF to increase MMP secretion and with the decreased MMP expression caused by inhibition of Egfr signalling in wild-type explants. Accordingly, inactivation of MMPs in wild-type explants phenocopied the defective morphology of Meckel's cartilage seen in Egfr-/- explants. Our results indicate that EGFR signalling is necessary for normal craniofacial development and that its role is mediated in part by its downstream targets, the MMPs, and may explain the genetic correlation of human cleft palate with polymorphisms in TGFA.

  20. Value of epidermal growth factor receptor status compared with growth fraction and other factors for prognosis in early breast cancer.

    PubMed Central

    Gasparini, G.; Bevilacqua, P.; Pozza, F.; Meli, S.; Boracchi, P.; Marubini, E.; Sainsbury, J. R.

    1992-01-01

    The epidermal growth factor receptor (EGFR) is a transmembrane glycoprotein whose expression is important in the regulation of breast cancer cell growth. The relationship between EGFR status (determined by an immunocytochemical assay) and various prognostic factors was investigated in 164 primary breast cancers. Overall 56% of tumours were EGFR-positive and the expression of EGFR was unrelated to axillary node status, tumour size and histological grade; and it was poorly associated with the tumour proliferative activity measured by Ki-67 immuno-cytochemistry. The relapse-free survival (RFS) probability at 3-years was significantly worse for patients with EGFR positive tumours (P = 0.003) and for those whose Ki-67 score was > 7.5% (P = 0.0027), as well as in patients with axillary node involvement (P = 0.01) and with poorly differentiated tumours (P = 0.04). Immunocytochemical determination of EGFR and cell kinetics gave superimposable prognostic information for predicting RFS with odds ratios of 3.51, when evaluated singly. In our series of patients EGFR, Ki-67 and node status retain their prognostic value concerning RFS in multivariate analysis. The 3-year probability of overall survival (OS) was significantly better in node-negative patients (P = 0.04) and was similar in EGFR-positive and negative patients. In conclusion, EGFR status appears to be a significant and independent indicator of recurrence in human breast cancer and the concomitant measurement of the tumour proliferative activity seems to improve the selection of patients with different risks of recurrence. PMID:1419645

  1. Illuminating epidermal growth factor receptor densities on filopodia through plasmon coupling.

    PubMed

    Wang, Jing; Boriskina, Svetlana V; Wang, Hongyun; Reinhard, Björn M

    2011-08-23

    Filopodia have been hypothesized to act as remote sensors of the cell environment, but many details of the sensor function remain unclear. We investigated the distribution of the epidermal growth factor (EGF) receptor (EGFR) density on filopodia and on the dorsal cell membrane of A431 human epidermoid carcinoma cells using a nanoplasmonic enabled imaging tool. We targeted cell surface EGFR with 40 nm diameter Au nanoparticles (NPs) using a high affinity multivalent labeling strategy and determined relative NP binding affinities spatially resolved through plasmon coupling. Distance-dependent near-field interactions between the labels generated a NP density (ρ)-dependent spectral response that facilitated a spatial mapping of the EGFR density distribution on subcellular length scales in an optical microscope in solution. The measured ρ values were significantly higher on filopodia than on the cellular surface, which is indicative of an enrichment of EGFR on filopodia. A detailed characterization of the spatial distribution of the NP immunolabels through scanning electron microscopy (SEM) confirmed the findings of the all-optical plasmon coupling studies and provided additional structural details. The NPs exhibited a preferential association with the sides of the filopodia. We calibrated the ρ-dependent spectral response of the Au immunolabels through correlation of optical spectroscopy and SEM. The experimental dependence of the measured plasmon resonance wavelength (λ(res)) of the interacting immunolabels on ρ was well described by the fit λ(res) = 595.0 nm - 46.36 nm exp(-ρ/51.48) for ρ ≤ 476 NPs/μm(2). The performed correlated spectroscopic/SEM studies pave the way toward quantitative immunolabeling studies of EGFR and other important cell surface receptors in an optical microscope. PMID:21761914

  2. Rapidly activated epidermal growth factor receptor mediates lipopolysaccharide-triggered migration of microglia.

    PubMed

    Qu, Wen-Sheng; Liu, Jun-Li; Li, Chun-Yu; Li, Xiao; Xie, Min-Jie; Wang, Wei; Tian, Dai-Shi

    2015-11-01

    Previous reports have suggested that epidermal growth factor receptor (EGFR) is involved in microglia activation characterized by cell morphology changes, cytokine production and cell migration; and the biochemical regulation of the microglia migration is a potential therapeutic target following CNS inflammatory damages. However, the role of EGFR in microglia motility after inflammatory stimulation remains unknown. In the present study, lipopolysaccharide (LPS) was found to trigger rapid EGFR phosphorylation within 10 min, which was sustained during long-term stimulation in both primary microglial cells and the cultured BV2 microglial cells, furthermore, blocking EGFR phosphorylation by AG1478 significantly attenuated the LPS-induced chemotactic and chemokinetic migration of microglia. In addition, LPS could initiate calcium oscillation in microglia during live-cell recording, however, an intracellular calcium chelator and a selective inhibitor of calcium/calmodulin-dependent protein kinase II, but not an extracellular calcium chelator, remarkably suppressed the LPS-induced EGFR phosphorylation in BV2 microglia cells. As EGFR is not a traditional receptor for LPS, these findings suggest that the rapid phosphorylation of EGFR is attributed to the LPS-triggered intracellular calcium mobilization. By examining the downstream signals of EGFR, we further proved that extracellular signal-regulated kinase (ERK) is essential for EGFR-mediated microglia migration, because ERK inhibition attenuated the chemotactic and chemokinetic migration of microglia that had been induced by either LPS or EGF. Collectively, these results suggest that LPS could trigger the rapid phosphorylation of EGFR and subsequent ERK activation through mobilizing calcium activity, which underlies the microglia migration in an inflammatory condition.

  3. Epidermal Growth Factor and Intestinal Barrier Function.

    PubMed

    Tang, Xiaopeng; Liu, Hu; Yang, Shufen; Li, Zuohua; Zhong, Jinfeng; Fang, Rejun

    2016-01-01

    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. PMID:27524860

  4. Epidermal Growth Factor and Intestinal Barrier Function

    PubMed Central

    Liu, Hu; Yang, Shufen; Li, Zuohua; Zhong, Jinfeng

    2016-01-01

    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. PMID:27524860

  5. Insulin receptor substrate-1 involvement in epidermal growth factor receptor and insulin-like growth factor receptor signalling: implication for Gefitinib ('Iressa') response and resistance.

    PubMed

    Knowlden, Janice M; Jones, Helen E; Barrow, Denise; Gee, Julia M W; Nicholson, Robert I; Hutcheson, Iain R

    2008-09-01

    Classically the insulin receptor substrate-1 (IRS-1) is an essential component of insulin-like growth factor type 1 receptor (IGF-IR) signalling, providing an interface between the receptor and key downstream signalling cascades. Here, however, we show that in tamoxifen-resistant MCF-7 (Tam-R) breast cancer cells, that are highly dependent on epidermal growth factor receptor (EGFR) for growth, IRS-1 can interact with EGFR and be preferentially phosphorylated on tyrosine (Y) 896, a Grb2 binding site. Indeed, phosphorylation of this site is greatly enhanced by exposure of these cells, and other EGFR-positive cell lines, to EGF. Importantly, while IGF-II promotes phosphorylation of IRS-1 on Y612, a PI3-K recruitment site, it has limited effect on Y896 phosphorylation in Tam-R cells. Furthermore, EGF and IGF-II co-treatment, reduces the ability of IGF-II to phosphorylate Y612, whilst maintaining Y896 phosphorylation, suggesting that the EGFR is the dominant recruiter of IRS-1 in this cell line. Significantly, challenge of Tam-R cells with the EGFR-selective tyrosine kinase inhibitor gefitinib, for 7 days, reduces IRS-1/EGFR association and IRS-1 Y896 phosphorylation, while promoting IRS-1/IGF-IR association and IRS-1 Y612 phosphorylation. Furthermore, gefitinib significantly enhances IGF-II-mediated phosphorylation of IRS-1 Y612 and AKT in Tam-R cells. Importantly, induction of this pathway by gefitinib can be abrogated by inhibition/downregulation of the IGF-IR. Our data would therefore suggest a novel association exists between the EGFR and IRS-1 in several EGFR-positive cancer cell lines. This association acts to promote phosphorylation of IRS-1 at Y896 and drive MAPK signalling whilst preventing recruitment of IRS-1 by the IGF-IR and inhibiting signalling via this receptor. Treatment with gefitinib alters the dynamics of this system, promoting IGF-IR signalling, the dominant gefitinib-resistant growth regulatory pathway in Tam-R cells, thus, potentially limiting

  6. Inductive mechanisms limiting response to anti-epidermal growth factor receptor therapy.

    PubMed

    Hutcheson, Iain R; Knowlden, Janice M; Jones, Helen E; Burmi, Rajpal S; McClelland, Richard A; Barrow, Denise; Gee, Julia M W; Nicholson, Robert I

    2006-12-01

    Aberrant epidermal growth factor receptor (EGFR) signalling, a key feature of a variety of human malignancies, can drive a range of mechanisms underlying tumour growth and progression, including increased cell proliferation, angiogenesis, metastasis and decreased apoptosis. Anti-EGFR therapies, as monotherapies and in combination with chemotherapy, have proved effective in inhibiting these processes both in the clinical and in the preclinical settings. However, only a small cohort of patients have derived significant benefit from this therapy, with both de novo and acquired resistance to these agents evident in a number of recent studies. If we are to improve the effectiveness of such targeted therapies, then there is an urgent need to understand the resistance mechanisms. Here, we describe both non-genomic and genomic mechanisms of resistance to the selective EGFR tyrosine kinase inhibitor gefitinib (IRESSA), which we have identified initially in an EGFR-positive tamoxifen-resistant MCF-7 breast cancer cell line, but more recently in other EGFR-positive cancer types. Importantly, we show that gefitinib, in common with anti-hormonal agents, is not a passive bystander in the cellular response to drug treatment, but plays an active role in promoting signalling pathways that serve to limit its anti-tumour activity and maintain the cellular cohort from which acquired resistance can ultimately evolve. These findings indicate that inductive signalling is an important determinant of response to EGFR-targeted therapies and deciphering such pathways may provide us with the opportunity to design more effective strategies to combat resistance mechanisms and improve response to initial therapy.

  7. Graphene Enhances Cellular Proliferation through Activating the Epidermal Growth Factor Receptor.

    PubMed

    Liu, Wei; Sun, Cheng; Liao, Chunyang; Cui, Lin; Li, Haishan; Qu, Guangbo; Yu, Wenlian; Song, Naining; Cui, Yuan; Wang, Zheng; Xie, Wenping; Chen, Huiming; Zhou, Qunfang

    2016-07-27

    Graphene has promising applications in food packaging, water purification, and detective sensors for contamination monitoring. However, the biological effects of graphene are not fully understood. It is necessary to clarify the potential risks of graphene exposure to humans through diverse routes, such as foods. In the present study, graphene, as the model nanomaterial, was used to test its potential effects on the cell proliferation based on multiple representative cell lines, including HepG2, A549, MCF-7, and HeLa cells. Graphene was characterized by Raman spectroscopy, particle size analysis, atomic force microscopy, and transmission electron microscopy. The cellular responses to graphene exposure were evaluated using flow cytometry, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, and alamarBlue assays. Rat cerebral astrocyte cultures, as the non-cancer cells, were used to assess the potential cytotoxicity of graphene as well. The results showed that graphene stimulation enhanced cell proliferation in all tested cell cultures and the highest elevation in cell growth was up to 60%. A western blot assay showed that the expression of epidermal growth factor (EGF) was upregulated upon graphene treatment. The phosphorylation of EGF receptor (EGFR) and the downstream proteins, ShC and extracellular regulating kinase (ERK), were remarkably induced, indicating that the activation of the mitogen-activated protein kinase (MAPK)/ERK signaling pathway was triggered. The activation of PI3 kinase p85 and AKT showed that the PI3K/AKT signaling pathway was also involved in graphene-induced cell proliferation, causing the increase of cell ratios in the G2/M phase. No influences on cell apoptosis were observed in graphene-treated cells when compared to the negative controls, proving the low cytotoxicity of this emerging nanomaterial. The findings in this study revealed the potential cellular biological effect of graphene, which may give useful hints on its biosafety

  8. The epidermal growth factor receptor decreases Stathmin 1 and triggers catagen entry in the mouse.

    PubMed

    Bichsel, Kyle J; Hammiller, Brianna; Trempus, Carol S; Li, Yanhua; Hansen, Laura A

    2016-04-01

    The epidermal growth factor receptor (EGFR) is necessary for normal involution of hair follicles after the growth phase of anagen, although the mechanisms through which it acts are not well understood. In this report, we used transcriptional profiling of microdissected hair follicles from mice with skin-targeted deletion of Egfr to investigate how EGFR activation triggers catagen. Immunofluorescence for phospho-EGFR in mouse skin revealed increased activation of EGFR in follicular keratinocytes at catagen onset. Consistent with other models of EGFR deficiency, mice with skin-targeted deletion of Egfr (Krt14-Cre(+) /Egfr(fl/fl) ) exhibited a delayed and asynchronous catagen entry. Transcriptional profiling at the time of normal catagen onset at post-natal day (P) 17 revealed increased expression of the mitotic regulator Rcc2 in hair follicles lacking EGFR. Rcc2 protein was strongly immunopositive in the nuclei of control follicular keratinocytes at P16 then rapidly decreased until it was undetectable between P18 and 21. In contrast, Rcc2 expression continued in Egfr mutant follicles throughout this period. Proliferation, measured by bromodeoxyuridine incorporation, was also significantly increased in Egfr mutant follicular keratinocytes compared to controls at P18-21. Similarly, Rcc2-regulated mitotic regulator Stathmin 1 was strikingly reduced in control but not Egfr mutant follicles between P17 and P19. Deletion of Stmn1, in turn, accelerated catagen entry associated with premature cessation of proliferation in the hair follicles. These data reveal EGFR suppression of mitotic regulators including Rcc2 and Stathmin 1 as a mechanism for catagen induction in mouse skin.

  9. Selective Targeting of Antibody Conjugated Multifunctional Nanoclusters (Nanoroses) to Epidermal Growth Factor Receptors in Cancer Cells

    PubMed Central

    Ma, Li Leo; Tam, Justina O.; Willsey, Brian W.; Rigdon, Daniel; Ramesh, Rajagopal; Sokolov, Konstantin; Johnston, Keith P.

    2011-01-01

    The ability of smaller than 100 nm antibody (Ab) nanoparticle conjugates to target and modulate the biology of specific cell types may enable major advancements in cellular imaging and therapy in cancer. A key challenge is to load a high degree of targeting, imaging, and therapeutic functionality into small, yet stable particles. A versatile method called thin autocatalytic growth on substrate (TAGs) has been developed in our previous study to form ultra-thin and asymmetric gold coatings on iron oxide nanocluster cores producing exceptional near infrared (NIR) absorbance. AlexaFluor 488 labeled Abs were used to correlate the number of Abs conjugated to iron oxide/gold nanoclusters (nanoroses) with the hydrodynamic size. A transition from sub-monolayer to multilayer aggregates of Abs on the nanorose surface was observed for 54 Abs and an overall particle diameter of ~60 to 65 nm. The hydrodynamic diameter indicated coverage of a monolayer of 54 Abs, in agreement with the prediction of a geometric model, by assuming a circular footprint of 16.9 nm diameter per Ab molecule. The targeting efficacy of nanoclusters conjugated with monoclonal Abs specific for epidermal growth factor receptor (EGFR) was evaluated in A431 cancer cells using dark field microscopy and atomic absorbance spectrometry (AAS) analysis. Intense NIR scattering was achieved from both high uptake of nanoclusters in cells and high intrinsic NIR absorbance of individual nanoclusters. Dual mode imaging with dark field reflectance microscopy and fluorescence microscopy indicates the Abs remained attached to the Au surfaces upon the uptake by the cancer cells. The ability to load intense multifunctionality, specifically strong NIR absorbance, conjugation of an Ab monolayer in addition to a strong r2 MRI contrast that was previously demonstrated in a total particle size of only 63 nm, is an important step forward in development of theranostic agents for combined molecular specific imaging and therapy. PMID

  10. beta-Arrestin mediates beta1-adrenergic receptor-epidermal growth factor receptor interaction and downstream signaling.

    PubMed

    Tilley, Douglas G; Kim, Il-Man; Patel, Priyesh A; Violin, Jonathan D; Rockman, Howard A

    2009-07-24

    beta1-Adrenergic receptor (beta1AR) stimulation confers cardioprotection via beta-arrestin-de pend ent transactivation of epidermal growth factor receptors (EGFRs), however, the precise mechanism for this salutary process is unknown. We tested the hypothesis that the beta1AR and EGFR form a complex that differentially directs intracellular signaling pathways. beta1AR stimulation and EGF ligand can each induce equivalent EGFR phosphorylation, internalization, and downstream activation of ERK1/2, but only EGF ligand causes translocation of activated ERK to the nucleus, whereas beta1AR-stimulated/EGFR-transactivated ERK is restricted to the cytoplasm. beta1AR and EGFR are shown to interact as a receptor complex both in cell culture and endogenously in human heart, an interaction that is selective and undergoes dynamic regulation by ligand stimulation. Although catecholamine stimulation mediates the retention of beta1AR-EGFR interaction throughout receptor internalization, direct EGF ligand stimulation initiates the internalization of EGFR alone. Continued interaction of beta1AR with EGFR following activation is dependent upon C-terminal tail GRK phosphorylation sites of the beta1AR and recruitment of beta-arrestin. These data reveal a new signaling paradigm in which beta-arrestin is required for the maintenance of a beta1AR-EGFR interaction that can direct cytosolic targeting of ERK in response to catecholamine stimulation.

  11. Transient anabolic effects accompany epidermal growth factor receptor signal activation in articular cartilage in vivo

    PubMed Central

    2013-01-01

    Introduction Signals from the epidermal growth factor receptor (EGFR) have typically been considered to provide catabolic activities in articular cartilage, and accordingly have been suggested to have a causal role in osteoarthritis progression. The aim of this study was to determine in vivo roles for endogenous EGFR signal activation in articular cartilage. Methods Transgenic mice with conditional, limb-targeted deletion of the endogenous intracellular EGFR inhibitor Mig-6 were generated using CreLoxP (Mig-6-flox; Prx1Cre) recombination. Histology, histochemical staining and immunohistochemistry were used to confirm activation of EGFR signaling in the articular cartilage and joints, and to analyze phenotypic consequences of Mig-6 loss on articular cartilage morphology, proliferation, expression of progenitor cell markers, presence of chondrocyte hypertrophy and degradation of articular cartilage matrix. Results The articular cartilage of Mig-6-conditional knockout (Mig-6-cko) mice was dramatically and significantly thicker than normal articular cartilage at 6 and 12 weeks of age. Mig-6-cko articular cartilage contained a population of chondrocytes in which EGFR signaling was activated, and which were three to four times more proliferative than normal Mig-6-flox articular chondrocytes. These cells expressed high levels of the master chondrogenic regulatory factor Sox9, as well as high levels of putative progenitor cell markers including superficial zone protein (SZP), growth and differentiation factor-5 (GDF-5) and Notch1. Expression levels were also high for activated β-catenin and the transforming growth factor beta (TGF-β) mediators phospho-Smad2/3 (pSmad2/3). Anabolic effects of EGFR activation in articular cartilage were followed by catabolic events, including matrix degradation, as determined by accumulation of aggrecan cleavage fragments, and onset of hypertrophy as determined by type × collagen expression. By 16 weeks of age, the articular cartilage of

  12. Role of human epidermal growth factor receptor 2 in gastric cancer: Biological and pharmacological aspects

    PubMed Central

    Jørgensen, Jan Trøst

    2014-01-01

    Amplification of the human epidermal growth factor receptor 2 (HER2) gene and overexpression of the HER2 protein is found in 15%-20% of patients with gastric and gastroesophageal junction cancer. The degree of HER2 overexpression and amplification varies with the location of the carcinoma, with higher expression in the gastroesophageal and proximal parts compared to the distal parts of the stomach. Further, HER2 overexpression and amplification also seems to be related to the Lauren histological classification, with higher levels found in the intestinal phenotype compared to the diffuse and mixed types. The prognostic properties of HER2 overexpression and amplification are still under debate, but a large number of studies seem to indicate that HER2 is a negative prognostic factor. The usefulness of HER2 targeted therapy in gastric cancer was demonstrated in the ToGA trial, where HER2-positive patients with advanced gastric and gastroesophageal junction adenocarcinoma were randomized to receive 5-FU/capecitabine and cisplatin, either alone or in combination with trastuzumab. A statically significant gain in overall survival was seen in patients who received the combined treatment of trastuzumab and chemotherapy. Patients with a strong overexpression of the HER2 protein (IHC3+) specifically benefited from the treatment, with a median overall survival of 17.9 mo. As a consequence of the positive results of the ToGA trial, patients with advanced gastric or gastroesophageal junction adenocarcinoma are now routinely tested for HER2. The ToGA trial must be characterized as a landmark in the treatment of gastric cancer and it has paved the way for a number of new HER2 targeted compounds such as pertuzumab, ado-trastuzumab emtansine, lapatinib, afatinib, and dacomitinib, which are currently undergoing phase II and III clinical testing. Overall, this review will discuss the current status of HER2 in gastric and gastroesophageal junction cancer and the future direction in

  13. Epidermal growth factor receptor tyrosine kinase as a target for anticancer therapy.

    PubMed

    Raymond, E; Faivre, S; Armand, J P

    2000-01-01

    Increasing knowledge of the structure and function of the epidermal growth factor receptor (EGFR) subfamily of tyrosine kinases and of their role in the initiation and progression of various cancers has, in recent years, provided the impetus for a substantial research effort aimed at developing new anticancer therapies that target specific components of the EGFR signal transduction pathway. Selective compounds have been developed that target either the extracellular ligand-binding region of the EGFR or the intracellular tyrosine kinase region, resulting in interference with the signalling pathways that modulate mitogenic and other cancer-promoting responses (e.g. cell motility, cell adhesion, invasion and angiogenesis). Potential new anticancer agents that target the extracellular ligand-binding region of the receptor include a number of monoclonal antibodies, immunotoxins and ligand-binding cytotoxic agents. Agents that target the intracellular tyrosine kinase region include small molecule tyrosine kinase inhibitors (TKIs), which act by interfering with ATP binding to the receptor, and various other compounds that act at substrate-binding regions or downstream components of the signalling pathway. Currently, the most advanced of the newer therapies undergoing clinical development are antireceptor monoclonal antibodies (e.g. trastuzumab and cetuximab) and a number of small molecule EGFR-TKIs principally of the quinazoline and pyrazolo-pyrrolo-pyridopyrimidine inhibitor structural classes. The latter group of compounds offers several advantages in cancer chemotherapy, including the possibility of inhibiting specific deregulated pathways in cancer cells while having minimal effects on normal cell function. They also have favourable pharmacokinetic and pharmacodynamic properties and low toxicity, and some TKIs such as the reversible inhibitor ZD1839 ('Iressa') are now undergoing phase II to III clinical trials. In addition, the accumulation of evidence from laboratory

  14. High affinity nanobodies against human epidermal growth factor receptor selected on cells by E. coli display

    PubMed Central

    Salema, Valencio; Mañas, Carmen; Cerdán, Lidia; Piñero-Lambea, Carlos; Marín, Elvira; Roovers, Rob C.; Van Bergen en Henegouwen, Paul M.P.; Fernández, Luis Ángel

    2016-01-01

    ABSTRACT Most therapeutic antibodies (Abs) target cell surface proteins on tumor and immune cells. Cloning of Ab gene libraries in E. coli and their display on bacteriophages is commonly used to select novel therapeutic Abs binding target antigens, either purified or expressed on cells. However, the sticky nature of bacteriophages renders phage display selections on cells challenging. We previously reported an E. coli display system for expression of VHHs (i.e., nanobodies, Nbs) on the surface of bacteria and selection of high-affinity clones by magnetic cell sorting (MACS). Here, we demonstrate that E. coli display is also an attractive method for isolation of Nbs against cell surface antigens, such as the epidermal growth factor receptor (EGFR), upon direct selection and screening of Ab libraries on live cells. We employ a whole cell-based strategy using a VHH library obtained by immunization with human tumor cells over-expressing EGFR (i.e., A431), and selection of bacterial clones bound to murine fibroblast NIH-3T3 cells transfected with human EGFR, after depletion of non-specific clones on untransfected cells. This strategy resulted in the isolation of high-affinity Nbs binding distinct epitopes of EGFR, including Nbs competing with the ligand, EGF, as characterized by flow cytometry of bacteria displaying the Nbs and binding assays with purified Nbs using surface plasmon resonance. Hence, our study demonstrates that E. coli display of VHH libraries and selection on cells enables efficient isolation and characterization of high-affinity Nbs against cell surface antigens. PMID:27472381

  15. EphrinA5 suppresses colon cancer development by negatively regulating epidermal growth factor receptor stability.

    PubMed

    Wang, Tong-Hong; Chang, Junn-Liang; Ho, Jar-Yi; Wu, Hsiao-Chun; Chen, Tse-Ching

    2012-01-01

    Colon cancer is one of the most common human cancers worldwide. Owing to its aggressiveness and lethality, it is necessary to determine the mechanisms regulating the carcinogenesis of colon cancer. EphrinA5 has been reported to act as a putative tumor suppressor in glioma; however, little is known concerning the role of this protein in the context of colon cancer. To elucidate the biological significance of ephrinA5 in colon cancer, we examined ephrinA5 and epidermal growth factor receptor (EGFR) expression profiles in both colon cancer and normal tissues, using immunohistochemistry on a 96-spot tissue microarray. Gain-of-function and loss-of-function experiments were performed on the human colon cancer cell lines SW480 and WiDr to determine the biological effects of ephrinA5 in relation to cell proliferation, survival, and migration. It was found that ephrinA5 mRNA and protein levels were significantly reduced in colon cancer as compared with normal colon tissue specimens. EphrinA5 expression was also negatively associated with tumor differentiation and clinical stage. In colon cancer cell line models, ephrinA5 exerted an inhibitory effect on EGFR by promoting c-Cbl-mediated EGFR ubiquitination and degradation. EphrinA5 did not affect the transcriptional regulation of EGFR mRNA expression in colon cancer cells. Expression of ephrinA5 suppressed colon cancer cell proliferation, migration, and chemotherapeutic resistance. In conclusion, ephrinA5 inhibited colon cancer progression by promoting c-Cbl-mediated EGFR degradation. Our findings identify a novel mechanism that could be utilized to improve the therapeutic efficiency of EGFR-targeting strategies.

  16. Recommendations for Human Epidermal Growth Factor Receptor 2 Testing in Breast Cancer

    PubMed Central

    Wolff, Antonio C.; Hammond, M. Elizabeth H.; Hicks, David G.; Dowsett, Mitch; McShane, Lisa M.; Allison, Kimberly H.; Allred, Donald C.; Bartlett, John M.S.; Bilous, Michael; Fitzgibbons, Patrick; Hanna, Wedad; Jenkins, Robert B.; Mangu, Pamela B.; Paik, Soonmyung; Perez, Edith A.; Press, Michael F.; Spears, Patricia A.; Vance, Gail H.; Viale, Giuseppe; Hayes, Daniel F.

    2014-01-01

    Purpose To update the American Society of Clinical Oncology (ASCO)/College of American Pathologists (CAP) guideline recommendations for human epidermal growth factor receptor 2 (HER2) testing in breast cancer to improve the accuracy of HER2 testing and its utility as a predictive marker in invasive breast cancer. Methods ASCO/CAP convened an Update Committee that included coauthors of the 2007 guideline to conduct a systematic literature review and update recommendations for optimal HER2 testing. Results The Update Committee identified criteria and areas requiring clarification to improve the accuracy of HER2 testing by immunohistochemistry (IHC) or in situ hybridization (ISH). The guideline was reviewed and approved by both organizations. Recommendations The Update Committee recommends that HER2 status (HER2 negative or positive) be determined in all patients with invasive (early stage or recurrence) breast cancer on the basis of one or more HER2 test results (negative, equivocal, or positive). Testing criteria define HER2-positive status when (on observing within an area of tumor that amounts to >10% of contiguous and homogeneous tumor cells) there is evidence of protein overexpression (IHC) or gene amplification (HER2 copy number or HER2/CEP17 ratio by ISH based on counting at least 20 cells within the area). If results are equivocal (revised criteria), reflex testing should be performed using an alternative assay (IHC or ISH). Repeat testing should be considered if results seem discordant with other histopathologic findings. Laboratories should demonstrate high concordance with a validated HER2 test on a sufficiently large and representative set of specimens. Testing must be performed in a laboratory accredited by CAP or another accrediting entity. The Update Committee urges providers and health systems to cooperate to ensure the highest quality testing. PMID:24099077

  17. First in human nanotechnology doxorubicin delivery system to target epidermal growth factor receptors in recurrent glioblastoma.

    PubMed

    Whittle, James R; Lickliter, Jason D; Gan, Hui K; Scott, Andrew M; Simes, John; Solomon, Benjamin J; MacDiarmid, Jennifer A; Brahmbhatt, Himanshu; Rosenthal, Mark A

    2015-12-01

    There are limited treatment options for patients with recurrent glioblastoma (GBM). The EnGeneIC delivery vehicle (EDV) is a novel nanocellular (minicell) compound which packages theoretically effective concentrations of chemotherapeutic drugs that are designed to target tumors via minicell-surface attached bispecific proteins (EnGeneIC, Lane Cove West, NSW, Australia). Epidermal growth factor receptor (EGFR) is overexpressed in 40-50% of patients with GBM and is a promising target for new therapeutics. (V)EDVDox contains doxorubicin (Dox) within the minicells and targets EGFR through Vectibix (V; Amgen Biologicals, Thousand Oaks, CA, USA). We conducted a first in human Phase I study of (V)EDVDox in adults with recurrent GBM expressing EGFR on immunohistochemistry, following standard therapy including radiation and temozolomide, to establish a safe maximum tolerated dose and determine a recommended Phase II dose (RPTD). (V)EDVDox was administered weekly in an 8week cycle, with dose escalation in successive cohorts of patients using a standard 3+3 design. In total, 14 patients were treated at three dose levels, and the RPTD was identified as 5×10(9)(V)EDVDox. Overall (V)EDVDox was well tolerated, with no dose limiting toxicity and no withdrawals from the study due to adverse events. The most common adverse events were nausea, fever, and chills or rigors, experienced in seven, five and five patients, respectively. Transient uncomplicated hypophosphatemia was seen in seven patients and was not dose-related. Our results demonstrate that (V)EDVDox, up to a dose of 5×10(9)(V)EDVDox weekly, is well tolerated in patients with recurrent GBM.

  18. Selection of DNA aptamers against epidermal growth factor receptor with high affinity and specificity

    SciTech Connect

    Wang, Deng-Liang; Song, Yan-Ling; Zhu, Zhi; Li, Xi-Lan; Zou, Yuan; Yang, Hai-Tao; Wang, Jiang-Jie; Yao, Pei-Sen; Pan, Ru-Jun; Yang, Chaoyong James; Kang, De-Zhi

    2014-10-31

    Highlights: • This is the first report of DNA aptamer against EGFR in vitro. • Aptamer can bind targets with high affinity and selectivity. • DNA aptamers are more stable, cheap and efficient than RNA aptamers. • Our selected DNA aptamer against EGFR has high affinity with K{sub d} 56 ± 7.3 nM. • Our selected DNA aptamer against EGFR has high selectivity. - Abstract: Epidermal growth factor receptor (EGFR/HER1/c-ErbB1), is overexpressed in many solid cancers, such as epidermoid carcinomas, malignant gliomas, etc. EGFR plays roles in proliferation, invasion, angiogenesis and metastasis of malignant cancer cells and is the ideal antigen for clinical applications in cancer detection, imaging and therapy. Aptamers, the output of the systematic evolution of ligands by exponential enrichment (SELEX), are DNA/RNA oligonucleotides which can bind protein and other substances with specificity. RNA aptamers are undesirable due to their instability and high cost of production. Conversely, DNA aptamers have aroused researcher’s attention because they are easily synthesized, stable, selective, have high binding affinity and are cost-effective to produce. In this study, we have successfully identified DNA aptamers with high binding affinity and selectivity to EGFR. The aptamer named TuTu22 with K{sub d} 56 ± 7.3 nM was chosen from the identified DNA aptamers for further study. Flow cytometry analysis results indicated that the TuTu22 aptamer was able to specifically recognize a variety of cancer cells expressing EGFR but did not bind to the EGFR-negative cells. With all of the aforementioned advantages, the DNA aptamers reported here against cancer biomarker EGFR will facilitate the development of novel targeted cancer detection, imaging and therapy.

  19. Mechanisms of resistance to anti-epidermal growth factor receptor inhibitors in metastatic colorectal cancer

    PubMed Central

    Sforza, Vincenzo; Martinelli, Erika; Ciardiello, Fortunato; Gambardella, Valentina; Napolitano, Stefania; Martini, Giulia; della Corte, Carminia; Cardone, Claudia; Ferrara, Marianna L; Reginelli, Alfonso; Liguori, Giuseppina; Belli, Giulio; Troiani, Teresa

    2016-01-01

    The prognosis of patients with metastatic colorectal cancer (mCRC) remain poor despite the impressive improvement of treatments observed over the last 20 years that led to an increase in median overall survival from 6 mo, with the only best supportive care, to approximately 30 mo with the introduction of active chemotherapy drugs and targeted agents. The monoclonal antibodies (moAbs) cetuximab and panitumumab, directed against the epidermal growth factor receptor (EGFR), undoubtedly represent a major step forward in the treatment of mCRC, given the relevant efficacy in terms of progression-free survival, overall survival, response rate, and quality of life observed in several phase III clinical trials among different lines of treatment. However, the anti-EGFR moAbs were shown only to be effective in a subset of patients. For instance, KRAS and NRAS mutations have been identified as biomarkers of resistance to these drugs, improving the selection of patients who might derive a benefit from these treatments. Nevertheless, several other alterations might affect the response to these drugs, and unfortunately, even the responders eventually become resistant by developing secondary (or acquired) resistance in approximately 13-18 mo. Several studies highlighted that the landscape of responsible alterations of both primary and acquired resistance to anti-EGFR drugs biochemically converge into MEK-ERK and PIK3CA-AKT pathways. In this review, we describe the currently known mechanisms of primary and acquired resistance to anti-EGFR moAbs together with the various strategies evaluated to prevent, overcame or revert them.

  20. Mechanisms of resistance to anti-epidermal growth factor receptor inhibitors in metastatic colorectal cancer.

    PubMed

    Sforza, Vincenzo; Martinelli, Erika; Ciardiello, Fortunato; Gambardella, Valentina; Napolitano, Stefania; Martini, Giulia; Della Corte, Carminia; Cardone, Claudia; Ferrara, Marianna L; Reginelli, Alfonso; Liguori, Giuseppina; Belli, Giulio; Troiani, Teresa

    2016-07-28

    The prognosis of patients with metastatic colorectal cancer (mCRC) remain poor despite the impressive improvement of treatments observed over the last 20 years that led to an increase in median overall survival from 6 mo, with the only best supportive care, to approximately 30 mo with the introduction of active chemotherapy drugs and targeted agents. The monoclonal antibodies (moAbs) cetuximab and panitumumab, directed against the epidermal growth factor receptor (EGFR), undoubtedly represent a major step forward in the treatment of mCRC, given the relevant efficacy in terms of progression-free survival, overall survival, response rate, and quality of life observed in several phase III clinical trials among different lines of treatment. However, the anti-EGFR moAbs were shown only to be effective in a subset of patients. For instance, KRAS and NRAS mutations have been identified as biomarkers of resistance to these drugs, improving the selection of patients who might derive a benefit from these treatments. Nevertheless, several other alterations might affect the response to these drugs, and unfortunately, even the responders eventually become resistant by developing secondary (or acquired) resistance in approximately 13-18 mo. Several studies highlighted that the landscape of responsible alterations of both primary and acquired resistance to anti-EGFR drugs biochemically converge into MEK-ERK and PIK3CA-AKT pathways. In this review, we describe the currently known mechanisms of primary and acquired resistance to anti-EGFR moAbs together with the various strategies evaluated to prevent, overcame or revert them. PMID:27605871

  1. Human epidermal growth factor receptor 2/neu protein expression in meningiomas: An immunohistochemical study

    PubMed Central

    Telugu, Ramesh Babu; Chowhan, Amit Kumar; Rukmangadha, Nandyala; Patnayak, Rashmi; Phaneendra, Bobbidi Venkata; Prasad, Bodapati Chandra Mowliswara; Reddy, Mandyam Kumaraswamy

    2016-01-01

    Background: Meningiomas are common slow-growing primary central nervous system tumors that arise from the meningothelial cells of the arachnoid and spinal cord. Human epidermal growth factor receptor 2 (HER2) or HER2/neu (also known as c-erbB2) is a 185-kD transmembrane glycoprotein with tyrosine kinase activity expressed in meningiomas and various other tumors. It can be used in targeted therapy for HER2/neu positive meningiomas. Aim: To correlate the expression of HER2/neu protein in meningiomas with gender, location, histological subtypes, and grade. Materials and Methods: It was 3½ years prospective (March 2010–October 2011) and retrospective (May 2008–February 2010) study of histopathologically diagnosed intracranial and intraspinal meningiomas. Clinical details of all the cases were noted from the computerized hospital information system. Immunohistochemistry for HER2/neu protein was performed along with scoring. Statistical analysis was done using Chi-square test to look for any association of HER2/neu with gender, location, grade, and various histological subtypes of meningiomas at 5% level of significance. Results: A total of 100 cases of meningiomas were found during the study period. Of which, 80 were Grade I, 18 were Grade II, and 2 were Grade III meningiomas as per the World Health Organization 2007 criteria. The female-male ratio was 1.9:1 and the mean age was 47.8 years. HER2/neu protein was expressed in 75% of Grade I and 72.2% of Grade II and none of Grade III meningiomas. About 72.7% brain invasive meningiomas showed HER2/neu immunopositivity. Conclusion: HER2/neu protein was expressed in 73% of meningiomas. Statistically significant difference of HER2/neu expression was not seen between females and males of Grade I and Grade II/III meningiomas, intracranial and spinal tumors, Grade I and Grade II/III cases, and various histological subtypes of meningiomas.

  2. Mechanisms of resistance to anti-epidermal growth factor receptor inhibitors in metastatic colorectal cancer.

    PubMed

    Sforza, Vincenzo; Martinelli, Erika; Ciardiello, Fortunato; Gambardella, Valentina; Napolitano, Stefania; Martini, Giulia; Della Corte, Carminia; Cardone, Claudia; Ferrara, Marianna L; Reginelli, Alfonso; Liguori, Giuseppina; Belli, Giulio; Troiani, Teresa

    2016-07-28

    The prognosis of patients with metastatic colorectal cancer (mCRC) remain poor despite the impressive improvement of treatments observed over the last 20 years that led to an increase in median overall survival from 6 mo, with the only best supportive care, to approximately 30 mo with the introduction of active chemotherapy drugs and targeted agents. The monoclonal antibodies (moAbs) cetuximab and panitumumab, directed against the epidermal growth factor receptor (EGFR), undoubtedly represent a major step forward in the treatment of mCRC, given the relevant efficacy in terms of progression-free survival, overall survival, response rate, and quality of life observed in several phase III clinical trials among different lines of treatment. However, the anti-EGFR moAbs were shown only to be effective in a subset of patients. For instance, KRAS and NRAS mutations have been identified as biomarkers of resistance to these drugs, improving the selection of patients who might derive a benefit from these treatments. Nevertheless, several other alterations might affect the response to these drugs, and unfortunately, even the responders eventually become resistant by developing secondary (or acquired) resistance in approximately 13-18 mo. Several studies highlighted that the landscape of responsible alterations of both primary and acquired resistance to anti-EGFR drugs biochemically converge into MEK-ERK and PIK3CA-AKT pathways. In this review, we describe the currently known mechanisms of primary and acquired resistance to anti-EGFR moAbs together with the various strategies evaluated to prevent, overcame or revert them.

  3. Mechanisms of resistance to anti-epidermal growth factor receptor inhibitors in metastatic colorectal cancer

    PubMed Central

    Sforza, Vincenzo; Martinelli, Erika; Ciardiello, Fortunato; Gambardella, Valentina; Napolitano, Stefania; Martini, Giulia; della Corte, Carminia; Cardone, Claudia; Ferrara, Marianna L; Reginelli, Alfonso; Liguori, Giuseppina; Belli, Giulio; Troiani, Teresa

    2016-01-01

    The prognosis of patients with metastatic colorectal cancer (mCRC) remain poor despite the impressive improvement of treatments observed over the last 20 years that led to an increase in median overall survival from 6 mo, with the only best supportive care, to approximately 30 mo with the introduction of active chemotherapy drugs and targeted agents. The monoclonal antibodies (moAbs) cetuximab and panitumumab, directed against the epidermal growth factor receptor (EGFR), undoubtedly represent a major step forward in the treatment of mCRC, given the relevant efficacy in terms of progression-free survival, overall survival, response rate, and quality of life observed in several phase III clinical trials among different lines of treatment. However, the anti-EGFR moAbs were shown only to be effective in a subset of patients. For instance, KRAS and NRAS mutations have been identified as biomarkers of resistance to these drugs, improving the selection of patients who might derive a benefit from these treatments. Nevertheless, several other alterations might affect the response to these drugs, and unfortunately, even the responders eventually become resistant by developing secondary (or acquired) resistance in approximately 13-18 mo. Several studies highlighted that the landscape of responsible alterations of both primary and acquired resistance to anti-EGFR drugs biochemically converge into MEK-ERK and PIK3CA-AKT pathways. In this review, we describe the currently known mechanisms of primary and acquired resistance to anti-EGFR moAbs together with the various strategies evaluated to prevent, overcame or revert them. PMID:27605871

  4. Human epidermal growth factor receptor 2/neu protein expression in meningiomas: An immunohistochemical study

    PubMed Central

    Telugu, Ramesh Babu; Chowhan, Amit Kumar; Rukmangadha, Nandyala; Patnayak, Rashmi; Phaneendra, Bobbidi Venkata; Prasad, Bodapati Chandra Mowliswara; Reddy, Mandyam Kumaraswamy

    2016-01-01

    Background: Meningiomas are common slow-growing primary central nervous system tumors that arise from the meningothelial cells of the arachnoid and spinal cord. Human epidermal growth factor receptor 2 (HER2) or HER2/neu (also known as c-erbB2) is a 185-kD transmembrane glycoprotein with tyrosine kinase activity expressed in meningiomas and various other tumors. It can be used in targeted therapy for HER2/neu positive meningiomas. Aim: To correlate the expression of HER2/neu protein in meningiomas with gender, location, histological subtypes, and grade. Materials and Methods: It was 3½ years prospective (March 2010–October 2011) and retrospective (May 2008–February 2010) study of histopathologically diagnosed intracranial and intraspinal meningiomas. Clinical details of all the cases were noted from the computerized hospital information system. Immunohistochemistry for HER2/neu protein was performed along with scoring. Statistical analysis was done using Chi-square test to look for any association of HER2/neu with gender, location, grade, and various histological subtypes of meningiomas at 5% level of significance. Results: A total of 100 cases of meningiomas were found during the study period. Of which, 80 were Grade I, 18 were Grade II, and 2 were Grade III meningiomas as per the World Health Organization 2007 criteria. The female-male ratio was 1.9:1 and the mean age was 47.8 years. HER2/neu protein was expressed in 75% of Grade I and 72.2% of Grade II and none of Grade III meningiomas. About 72.7% brain invasive meningiomas showed HER2/neu immunopositivity. Conclusion: HER2/neu protein was expressed in 73% of meningiomas. Statistically significant difference of HER2/neu expression was not seen between females and males of Grade I and Grade II/III meningiomas, intracranial and spinal tumors, Grade I and Grade II/III cases, and various histological subtypes of meningiomas. PMID:27695231

  5. Chicken epidermal growth factor (EGF) receptor: cDNA cloning, expression in mouse cells, and differential binding of EGF and transforming growth factor alpha.

    PubMed Central

    Lax, I; Johnson, A; Howk, R; Sap, J; Bellot, F; Winkler, M; Ullrich, A; Vennstrom, B; Schlessinger, J; Givol, D

    1988-01-01

    The primary structure of the chicken epidermal growth factor (EGF) receptor was deduced from the sequence of a cDNA clone containing the complete coding sequence and shown to be highly homologous to the human EGF receptor. NIH-3T3 cells devoid of endogenous EGF receptor were transfected with the appropriate cDNA constructs and shown to express either chicken or human EGF receptors. Like the human EGF receptor, the chicken EGF receptor is a glycoprotein with an apparent molecular weight of 170,000. Murine EGF bound to the chicken receptor with approximately 100-fold lower affinity than to the human receptor molecule. Surprisingly, human transforming growth factor alpha (TGF-alpha) bound equally well or even better to the chicken EGF receptor than to the human EGF receptor. Moreover, TGF-alpha stimulated DNA synthesis 100-fold better than did EGF in NIH 3T3 cells that expressed the chicken EGF receptor. The differential binding and potency of mammalian EGF and TGF-alpha by the avian EGF receptor contrasts with the similar affinities of the mammalian receptor for the two growth factors. Images PMID:3260329

  6. Cross-talk between the calcium-sensing receptor and the epidermal growth factor receptor in Rat-1 fibroblasts

    SciTech Connect

    Tomlins, Scott A.; Bollinger, Nikki; Creim, Jeffrey A.; Rodland, Karin D.

    2005-08-15

    The calcium-sensing receptor (CaR) is a G-protein coupled receptor that is activated by extracellular calcium (Ca2+o). Rat-1 fibroblasts have been shown to proliferate and increase ERK activity in response to elevation of [Ca2+]o, and these responses are dependent on functional CaR expression. In this report, we examined the role of cross-talk between the CaR and the epidermal growth factor receptor (EGFR) in mediating these responses in Rat-1 cells. This report shows that AG1478, a specific inhibitor of the EGFR kinase, significantly inhibits the increase in proliferation induced by elevated Ca2+o. Further, we show that AG1478 acts downstream or separately from G-protein subunit activation of phospholipase C. AG1478 significantly inhibits Ca2+o-stimulated ERK phosphorylation and in vitro kinase activity. A similar inhibition of ERK phosphorylation was observed in response to the inhibitor AG494. In addition, treatment with inhibitors of metalloproteases involved in shedding of membrane anchored EGF family ligands substantially inhibited the increase in ERK activation in response to elevated Ca2+o. This is consistent with the known expression of TGFa by Rat-1 cells. These results indicate that EGFR transactivation is an important component of the CaR mediated response to increased Ca2+o in Rat-1 fibroblasts, and most likely involves CaR-mediated induction of regulated proteolysis and ligand shedding.

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

    PubMed

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

    2014-03-01

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

  8. Developments in epidermal growth factor receptor-targeting therapy for solid tumors: focus on matuzumab (EMD 72000).

    PubMed

    Schiller, Joan H

    2008-02-01

    Expression of epidermal growth factor and its transmembrane receptor (EGFR) stimulates tumor growth. Matuzumab is a humanized anti-EGFR monoclonal antibody that blocks EGFR activation and downstream signaling, inhibits tumor growth, and provides a clinical benefit for some patients. The plasma half-life (6-10 days) and pharmacodynamic activity allow flexible dosing on weekly, every-2-week, and every-3-week schedules. Matuzumab has shown single-agent antitumor activity in heavily pretreated patients with a variety of tumors, with a favorable safety profile. Skin rash is the most common toxicity, but is severe (Grade 3) in < 1 percent. This article describes preclinical and clinical development of matuzumab.

  9. Combined Vascular Endothelial Growth Factor Receptor and Epidermal Growth Factor Receptor (EGFR) Blockade Inhibits Tumor Growth in Xenograft Models of EGFR Inhibitor Resistance

    PubMed Central

    Naumov, George N.; Nilsson, Monique B.; Cascone, Tina; Briggs, Alexandra; Straume, Oddbjorn; Akslen, Lars A.; Lifshits, Eugene; Byers, Lauren Averett; Xu, Li; Wu, Hua-kang; Jänne, Pasi; Kobayashi, Susumu; Halmos, Balazs; Tenen, Daniel; Tang, Xi M.; Engelman, Jeffrey; Yeap, Beow; Folkman, Judah; Johnson, Bruce E.; Heymach, John V.

    2010-01-01

    Purpose The epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKI) gefitinib and erlotinib benefit some non–small cell lung cancer (NSCLC) patients, but most do not respond (primary resistance) and those who initially respond eventually progress (acquired resistance). EGFR TKI resistance is not completely understood and has been associated with certain EGFR and K-RAS mutations and MET amplification. Experimental Design We hypothesized that dual inhibition of the vascular endothelial growth factor (VEGF) and EGFR pathways may overcome primary and acquired resistance. We investigated the VEGF receptor/EGFR TKI vandetanib, and the combination of bevacizumab and erlotinib in vivo using xenograft models of EGFR TKI sensitivity, primary resistance, and three models of acquired resistance, including models with mutated K-RAS and secondary EGFR T790M mutation. Results Vandetanib, gefitinib, and erlotinib had similar profiles of in vitro activity and caused sustained tumor regressions in vivo in the sensitive HCC827 model. In all four resistant models, vandetanib and bevacizumab/erlotinib were significantly more effective than erlotinib or gefitinib alone. Erlotinib resistance was associated with a rise in both host and tumor-derived VEGF but not EGFR secondary mutations in the KRAS mutant-bearing A549 xenografts. Dual inhibition reduced tumor endothelial proliferation compared with VEGF or EGFR blockade alone, suggesting that the enhanced activity of dual inhibition is due at least in part to antiendothelial effects. Conclusion These studies suggest that erlotinib resistance may be associated with a rise in both tumor cell and host stromal VEGF and that combined blockade of the VEGFR and EGFR pathways can abrogate primary or acquired resistance to EGFR TKIs. This approach merits further evaluation in NSCLC patients. PMID:19447865

  10. Epidermal growth factor-like repeats of tenascin-C-induced constriction of cerebral arteries via activation of epidermal growth factor receptors in rats.

    PubMed

    Fujimoto, Masashi; Shiba, Masato; Kawakita, Fumihiro; Liu, Lei; Nakasaki, Asuka; Shimojo, Naoshi; Imanaka-Yoshida, Kyoko; Yoshida, Toshimichi; Suzuki, Hidenori

    2016-07-01

    Tenascin-C (TNC), one of matricellular proteins, has been suggested to be involved in cerebral vasospasm after aneurysmal subarachnoid hemorrhage. However, the mechanisms of how TNC constricts cerebral arteries remain unclear. The aim of this study was to examine if epidermal growth factor (EGF)-like repeats of TNC is involved in TNC-induced constriction of cerebral arteries in rats via EGF receptor (EGFR) activation. Two dosages of recombinant TNC (r-TNC) consisting of the EGF-like repeats was administered intracisternally to healthy rats, and its vasoconstrictor effects were evaluated by neurobehavioral tests and India-ink angiography at 24, 48, and 72 hours after the administration. Western blotting and immunohistochemistry were performed to explore the underlying mechanisms on constricted cerebral arteries after 24 hours. The effects of a selective EGFR tyrosine kinase inhibitor (AG1478) on r-TNC-induced vasoconstriction were evaluated by neurobehavioral tests, India-ink angiography and immunohistochemistry at 24 hours after the administration. A higher dosage of r-TNC induced cerebral arterial constriction more severely, which continued for 48 hours. The effects were associated with the activation of EGFR and extracellular signal-regulated kinase (ERK)1/2 in the smooth muscle cell layer of the constricted cerebral artery, while c-Jun N-terminal kinase and p38 were not activated. AG1478 blocked r-TNC-induced vasoconstrictive effects, as well as activation of EGFR and ERK1/2. These findings demonstrate that TNC induces constriction of cerebral arteries via activation of EGFR and ERK1/2.

  11. Roles of insulinlike growth factor 1 (IGF-1) and the IGF-1 receptor in epidermal growth factor-stimulated growth of 3T3 cells.

    PubMed Central

    Pietrzkowski, Z; Sell, C; Lammers, R; Ullrich, A; Baserga, R

    1992-01-01

    BALB/c3T3 cells are exquisitely growth regulated and require platelet-derived growth factor, epidermal growth factor (EGF), and insulinlike growth factor 1 (IGF-1) for growth. When BALB/c3T3 cells are transfected with plasmids constitutively expressing both EGF and the human IGF-1 receptor mRNAs, the cells are capable of growing in serum-free medium without the addition of any exogenous growth factor. These cells, called p5 cells, can grow for prolonged periods in serum-free medium. BALB/c3T3 cells transfected with only the IGF-1 receptor expression plasmid (p6 cells) do not grow in serum-free medium but do grow if IGF-1 (or insulin in supraphysiological concentrations) is added. p6 cells also grow in response to EGF, confirming that the combination of EGF and an overexpressed IGF-1 receptor is sufficient for the growth of 3T3 cells. We have found that in EGF-stimulated p6 cells there is an increase in the expression of IGF-1 mRNA, that IGF-1 is secreted into the medium, and that the growth of p5 cells and EGF-stimulated p6 cells is inhibited by exposure to antisense oligodeoxynucleotides to IGF-1 receptor RNA. Finally, while cells constitutively expressing both EGF and EGF receptor RNAs grow, albeit modestly, in serum-free medium, their growth is also inhibited by an antisense oligodeoxynucleotide to IGF-1 receptor RNA. In contrast, in cells overexpressing the IGF-1 receptor, IGF-1-mediated cell growth occurs independently of the platelet-derived growth factor and EGF receptors (Z. Pietrzkowski, R. Lammers, G. Carpenter, A. M. Soderquist, M. Limardo, P. D. Phillips, A. Ullrich, and R. Baserga, Cell Growth Differ. 3:199-205, 1992, and this paper). These data indicate that an important role for EGF is participation in the activation of an autocrine loop based on the IGF-1-IGF-1 receptor interaction, which is obligatory for the proliferation of 3T3 cells. Images PMID:1324408

  12. Expression of Human Epidermal Growth Factor Receptor-2 in Resected Rectal Cancer

    PubMed Central

    Meng, Xiangjiao; Huang, Zhaoqin; Di, Jian; Mu, Dianbin; Wang, Yawei; Zhao, Xianguang; Zhao, Hanxi; Zhu, Wanqi; Li, Xiaolin; Kong, Lingling; Xing, Ligang

    2015-01-01

    Abstract The addition of trastuzumab to chemotherapy was demonstrated to be beneficial for advanced human epidermal growth factor receptor-2 (HER-2) positive gastric cancer. However, the HER-2 status of rectal cancer remains uncertain. This study aimed to determine the HER-2 expression in a large multicenter cohort of rectal cancer patients. The clinical and pathological features of 717 patients were retrospectively reviewed. All the patients were diagnosed with primary rectal adenocarcinoma without distant metastasis and took surgery directly without any preoperative anticancer treatment. HER-2 status was assessed on resected samples. A total of 99 cases with IHC3+ and 16 cases with IHC 2+ plus gene amplification were determined as HER-2 positive. 22.6% of HER-2 positive patients had local recurrence, whereas 16.9% of HER-2 negative patients did (P = 0.146). HER-2 positive tumors were more likely to have distant metastasis (P = 0.007). Univariate analysis revealed that pathological tumor stage, pathological node stage, positive margin, and lymphovascular invasion were significantly correlated with 5-year disease-free survival (DFS) and 5-year overall survival (OS). The patients with >10 dissected lymph nodes showed significantly longer OS (P = 0.045) but not DFS (P = 0.054). HER-2 negative patients had significantly better 5-year DFS (P < 0.001) and 5-year OS (P = 0.013) than those of the HER-2 positive patients. In the subgroup analysis for the early rectal cancer and locally advanced rectal cancer, HER-2 was also a poor predictor for survival. Multivariate analysis revealed that HER-2 was an independent prognostic factor for 5-year DFS (hazard ratio [HR] = 1.919, 95% confidence interval [CI] 1.415–2.605, P < 0.001) and for 5-year OS (HR = 1.549, 95% CI 1.097–2.186, P = 0.013). When the treatment was included in the analysis for locally advanced patients, HER-2 was a prognostic factor for 5-year DFS (P = 0.001) but not for

  13. The coordinated functional expression of epidermal growth factor receptor and c-Met in colorectal carcinoma metastasis.

    PubMed

    Herynk, M H; Radinsky, R

    2000-01-01

    The process of metastasis is a highly selective, nonrandom process resulting in the clonal selection of a population of cells that is able to detach from the primary tumor, invade and survive in the circulation, arrest, extravasate, and ultimately survive and proliferate in the secondary organ-specific site. Tumor cell interactions with the microenvironment can profoundly influence the survival and proliferation of the cell at a secondary site. The epidermal growth factor receptor (EGFR) and the hepatocyte growth factor receptor (c-Met) are two such receptor tyrosine kinases (RTKs) that have been causally implicated in colorectal carcinoma (CRC) progression and metastasis. Activation of these RTKs can stimulate a number of specific pathways directly effecting tumor cell migration, survival and proliferation. The aberrant regulation of the RTKs is often noted in advanced CRC and its' liver metastases and can significantly effect the metastatic phenotype of tumor cells.

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

    PubMed

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

    2014-08-15

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

  15. Pharmacological Inhibition of Microsomal Prostaglandin E Synthase-1 Suppresses Epidermal Growth Factor Receptor-Mediated Tumor Growth and Angiogenesis

    PubMed Central

    Bocci, Elena; Coletta, Isabella; Polenzani, Lorenzo; Mangano, Giorgina; Alisi, Maria Alessandra; Cazzolla, Nicola; Giachetti, Antonio; Ziche, Marina; Donnini, Sandra

    2012-01-01

    Background Blockade of Prostaglandin (PG) E2 production via deletion of microsomal Prostaglandin E synthase-1 (mPGES-1) gene reduces tumor cell proliferation in vitro and in vivo on xenograft tumors. So far the therapeutic potential of the pharmacological inhibition of mPGES-1 has not been elucidated. PGE2 promotes epithelial tumor progression via multiple signaling pathways including the epidermal growth factor receptor (EGFR) signaling pathway. Methodology/Principal Findings Here we evaluated the antitumor activity of AF3485, a compound of a novel family of human mPGES-1 inhibitors, in vitro and in vivo, in mice bearing human A431 xenografts overexpressing EGFR. Treatment of the human cell line A431 with interleukin-1beta (IL-1β) increased mPGES-1 expression, PGE2 production and induced EGFR phosphorylation, and vascular endothelial growth factor (VEGF) and fibroblast growth factor-2 (FGF-2) expression. AF3485 reduced PGE2 production, both in quiescent and in cells stimulated by IL-1β. AF3485 abolished IL-1β-induced activation of the EGFR, decreasing VEGF and FGF-2 expression, and tumor-mediated endothelial tube formation. In vivo, in A431 xenograft, AF3485, administered sub-chronically, decreased tumor growth, an effect related to inhibition of EGFR signalling, and to tumor microvessel rarefaction. In fact, we observed a decrease of EGFR phosphorylation, and VEGF and FGF-2 expression in tumours explanted from treated mice. Conclusion Our work demonstrates that the pharmacological inhibition of mPGES-1 reduces squamous carcinoma growth by suppressing PGE2 mediated-EGFR signalling and by impairing tumor associated angiogenesis. These results underscore the potential of mPGES-1 inhibitors as agents capable of controlling tumor growth. PMID:22815767

  16. Anti-epidermal growth factor receptor conjugated mesoporous zinc oxide nanofibers for breast cancer diagnostics.

    PubMed

    Ali, Md Azahar; Mondal, Kunal; Singh, Chandan; Malhotra, Bansi Dhar; Sharma, Ashutosh

    2015-04-28

    We report the fabrication of an efficient, label-free, selective and highly reproducible immunosensor with unprecedented sensitivity (femto-molar) to detect a breast cancer biomarker for early diagnostics. Mesoporous zinc oxide nanofibers (ZnOnFs) are synthesized by electrospinning technique with a fiber diameter in the range of 50-150 nm. Fragments of ZnOnFs are electrophoretically deposited on an indium tin oxide glass substrate and conjugated via covalent or electrostatic interactions with a biomarker (anti-ErbB2; epidermal growth factor receptor 2). Oxygen plasma treatment of the carbon doped ZnOnFs generates functional groups (-COOH, -OH, etc.) that are effective for the conjugation of anti-ErbB2. ZnOnFs without plasma treatment that conjugate via electrostatic interactions were also tested for comparison. Label-free detection of the breast cancer biomarker by this point-of-care device is achieved by an electrochemical impedance technique that has high sensitivity (7.76 kΩ μM(-1)) and can detect 1 fM (4.34 × 10(-5) ng mL(-1)) concentration. The excellent impedimetric response of this immunosensor provides a fast detection (128 s) in a wide detection test range (1.0 fM-0.5 μM). The oxy-plasma treated ZnOnF immunoelectrode shows a higher association constant (404.8 kM(-1) s(-1)) indicating a higher affinity towards the ErbB2 antigen compared to the untreated ZnOnF immunoelectrode (165.6 kM(-1) s(-1)). This sensor is about an order of magnitude more sensitive than the best demonstrated in the literature based on different nanomaterials and about three orders of magnitude better than the ELISA standard for breast cancer biomarker detection. This proposed point-of-care cancer diagnostic offers several advantages, such as higher stability, rapid monitoring, simplicity, cost-effectiveness, etc., and should prove to be useful for the detection of other bio- and cancer markers. PMID:25811908

  17. The status of epidermal growth factor receptor in borderline ovarian tumours.

    PubMed

    Showeil, Rania; Romano, Claudia; Valganon, Mikel; Lambros, Maryou; Trivedi, Pritesh; Van Noorden, Susan; Sriraksa, Ruethairat; El-Kaffash, Dalal; El-Etreby, Nour; Natrajan, Rachael; Foroni, Letizia; Osborne, Richard; El-Bahrawy, Mona

    2016-03-01

    The majority of borderline ovarian tumours (BOTs) behave in a benign fashion, but some may show aggressive behavior. The reason behind this has not been elucidated. The epidermal growth factor receptor (EGFR) is known to contribute to cell survival signals as well as metastatic potential of some tumours. EGFR expression and gene status have not been thoroughly investigated in BOTs as it has in ovarian carcinomas. In this study we explore protein expression as well as gene mutations and amplifications of EGFR in BOTs in comparison to a subset of other epithelial ovarian tumours. We studied 85 tumours, including 61 BOTs, 10 low grade serous carcinomas (LGSCs), 9 high grade serous carcinomas (HGSCs) and 5 benign epithelial tumours. EGFR protein expression was studied using immunohistochemistry. Mutations were investigated by Sanger sequencing exons 18-21 of the tyrosine kinase domain of EGFR. Cases with comparatively higher protein expression were examined for gene amplification by chromogenic in situ hybridization. We also studied the tumours for KRAS and BRAF mutations. Immunohistochemistry results revealed both cytoplasmic and nuclear EGFR expression with variable degrees between tumours. The level of nuclear localization was relatively higher in BOTs and LGSCs as compared to HGSCs or benign tumours. The degree of nuclear expression of BOTs showed no significant difference from that in LGSCs (mean ranks 36.48, 33.05, respectively, p=0.625), but was significantly higher than in HGSCs (mean ranks: 38.88, 12.61 respectively, p< 0.001) and benign tumours (mean ranks: 35.18, 13.00 respectively, p= 0.010). Cytoplasmic expression level was higher in LGSCs. No EGFR gene mutations or amplification were identified, yet different polymorphisms were detected. Five different types of point mutations in the KRAS gene and the V600E BRAF mutation were detected exclusively in BOTs and LGSCs. Our study reports for the first time nuclear localization of EGFR in BOTs. The nuclear

  18. Is there an immunohistochemical technique definitively valid in epidermal growth factor receptor assessment?

    PubMed

    Penault-Llorca, Frédérique; Cayre, Anne; Arnould, Laurent; Bibeau, Frédéric; Bralet, Marie-Pierre; Rochaix, Philippe; Savary, Jacqueline; Sabourin, Jean-Christophe

    2006-12-01

    Immunohistochemistry (IHC) is required for the selection of patients for a monoclonal antibody based targeted treatment with C225 (Erbitux). To validate the usefulness of IHC, the confirmation of assays and scoring systems are mandatory. In an attempt to standardize the immunohistochemical detection of the epidermal growth factor receptor (EGFR), we retrospectively evaluated three commercially available EGFR kits or antibodies and analyzed the discrepancies between the tests in terms of the percentage of positive cells, intensity, cut-off value and fixatives. We extracted 232 paraffin-embedded samples from a metastatic colorectal cancer clinical trial. For all the cases, EGFR expression was assessed with the FDA approved Dako EGFR pharmaDx kit, the Zymed EGFR kit and the Ventana EGFR 3C6 antibody. Different cut-off values were tested, and the intensity was scored 0, 1+, 2+, 3+ following Dako's recommendations. The percentage of positive cases varied from 93 to 75% with a cut-off of value 1% of positive cells, from 80 to 61% with a cut-off of 5% positive cells and from 72% to 48% with a cut-off value of 10%. Both Ventana and Zymed tests were more sensitive than the Dako test (Ventana >Dako; p<10(-7), Zymed >Dako; p=2.10(-6)). No difference was noted between Ventana and Zymed tests (p=0.75). A high concordance was observed for the 3 tests for the evaluation of high intensities. The use of a scoring system combining the percentage of positive cells and intensity was not useful for Zymed and Ventana as the intensity of staining is correlated to the percentage of positive cells: Ventana (p<10(-6)) and Zymed (p<10(-5)). No interaction with staining was identified for any of the fixatives, or with the nature of samples received (i.e. slides vs blocks, biopsies vs surgical specimens). Our data showed a higher percentage of positive cells detected by Ventana and Zymed tests, whatever the cut-off value for positivity. No scoring system showed, to date, its accuracy, and more

  19. Synthetic and natural consensus design for engineering charge within an affibody targeting epidermal growth factor receptor.

    PubMed

    Case, Brett A; Hackel, Benjamin J

    2016-08-01

    Protein ligand charge can impact physiological delivery with charge reduction often benefiting performance. Yet neutralizing mutations can be detrimental to protein function. Herein, three approaches are evaluated to introduce charged-to-neutral mutations of three cations and three anions within an affibody engineered to bind epidermal growth factor receptor. These approaches-combinatorial library sorting or consensus design, based on natural homologs or library-sorted mutants-are used to identify mutations with favorable affinity, stability, and recombinant yield. Consensus design, based on 942 affibody homologs, yielded a mutant of modest function (Kd  = 11 ±4 nM, Tm  = 62°C, and yield = 4.0 ± 0.8 mg/L as compared to 5.3 ± 1.7 nM, 71°C, and 3.5 ± 0.3 mg/L for the parental affibody). Extension of consensus design to 10 additional mutants exhibited varied performance including a substantially improved mutant (Kd  = 6.9 ± 1.4 nM, Tm  = 71°C, and 12.7 ± 0.9 mg/L yield). Sorting a homolog-based combinatorial library of 7 × 10(5) mutants generated a distribution of mutants with lower stability and yield, but did identify one strongly binding variant (Kd  = 1.2 ± 0.3 nM, Tm  = 69°C, and 6.0 ± 0.4 mg/L yield). Synthetic consensus design, based on the amino acid distribution in functional library mutants, yielded higher affinities (P = 0.05) with comparable stabilities and yields. The best of four analyzed clones had Kd  = 1.7 ± 0.5 nM, Tm  = 68°C, and 7.0 ± 0.5 mg/L yield. While all three approaches were effective in creating targeted affibodies with six charged-to-neutral mutations, synthetic consensus design proved to be the most robust. Synthetic consensus design provides a valuable tool for ligand engineering, particularly in the context of charge manipulation. Biotechnol. Bioeng. 2016;113: 1628-1638. © 2016 Wiley Periodicals, Inc.

  20. Yes and Lyn play a role in nuclear translocation of the epidermal growth factor receptor.

    PubMed

    Iida, M; Brand, T M; Campbell, D A; Li, C; Wheeler, D L

    2013-02-01

    The epidermal growth factor receptor (EGFR) is a central regulator of tumor progression in human cancers. Cetuximab is an anti-EGFR antibody that has been approved for use in oncology. Previously we investigated mechanisms of resistance to cetuximab using a model derived from the non-small cell lung cancer line NCI-H226. We demonstrated that cetuximab-resistant clones (Ctx(R)) had increased nuclear localization of the EGFR. This process was mediated by Src family kinases (SFKs), and nuclear EGFR had a role in resistance to cetuximab. To better understand SFK-mediated nuclear translocation of EGFR, we investigated which SFK member(s) controlled this process as well as the EGFR tyrosine residues that are involved. Analyses of mRNA and protein expression indicated upregulation of the SFK members Yes (v-Yes-1 yamaguchi sarcoma viral oncogene) and Lyn (v-yes-1 Yamaguchi sarcoma viral-related oncogene homolog) in all Ctx(R) clones. Further, immunoprecipitation analysis revealed that EGFR interacts with Yes and Lyn in Ctx(R) clones, but not in cetuximab-sensitive (Ctx(S)) parental cells. Using RNAi interference, we found that knockdown of either Yes or Lyn led to loss of EGFR translocation to the nucleus. Conversely, overexpression of Yes or Lyn in low nuclear EGFR-expressing Ctx(S) parental cells led to increased nuclear EGFR. Chromatin immunoprecipitation (ChIP) assays confirmed nuclear EGFR complexes associated with the promoter of the known EGFR target genes B-Myb and iNOS. Further, all Ctx(R) clones exhibited upregulation of B-Myb and iNOS at the mRNA and protein levels. siRNAs directed at Yes or Lyn led to decreased binding of EGFR complexes to the B-Myb and iNOS promoters based on ChIP analyses. SFKs have been shown to phosphorylate EGFR on tyrosines 845 and 1101 (Y845 and Y1101), and mutation of Y1101, but not Y845, impaired nuclear entry of the EGFR. Taken together, our findings demonstrate that Yes and Lyn phosphorylate EGFR at Y1101, which influences EGFR

  1. Affibody-functionalized gold-silica nanoparticles for Raman molecular imaging of the epidermal growth factor receptor.

    PubMed

    Jokerst, Jesse V; Miao, Zheng; Zavaleta, Cristina; Cheng, Zhen; Gambhir, Sanjiv S

    2011-03-01

    The affibody functionalization of fluorescent surface-enhanced Raman scattering gold-silica nanoparticles as multimodal contrast agents for molecular imaging specific to epidermal growth factor receptor (EGFR) is reported. This nanoparticle bioconjugate reports EGFR-positive A431 tumors with a signal nearly 35-fold higher than EGFR-negative MDA-435S tumors. The low-level EGFR expression in adjacent healthy tissue is 7-fold lower than in the positive tumors. Validation via competitive inhibition reduces the signal by a factor of six, and independent measurement of EGFR via flow cytometry correlates at R(2) = 0.92. PMID:21302357

  2. Affibody-Functionalized Gold–Silica Nanoparticles for Raman Molecular Imaging of the Epidermal Growth Factor Receptor

    PubMed Central

    Jokerst, Jesse V.; Miao, Zheng; Zavaleta, Cristina; Cheng, Zhen; Gambhir, Sanjiv S.

    2012-01-01

    The affibody functionalization of fluorescent surface-enhanced Raman scattering gold–silica nanoparticles as multimodal contrast agents for molecular imaging specific to epidermal growth factor receptor (EGFR) is reported. This nanoparticle bioconjugate reports EGFR-positive A431 tumors with a signal nearly 35-fold higher than EGFR-negative MDA-435S tumors. The low-level EGFR expression in adjacent healthy tissue is 7-fold lower than in the positive tumors. Validation via competitive inhibition reduces the signal by a factor of six, and independent measurement of EGFR via flow cytometry correlates at R2 = 0.92. PMID:21302357

  3. An Autopsy Case of Two Distinct, Acquired Drug Resistance Mechanisms in Epidermal Growth Factor Receptor-mutant Lung Adenocarcinoma: Small Cell Carcinoma Transformation and Epidermal Growth Factor Receptor T790M Mutation.

    PubMed

    Furugen, Makoto; Uechi, Kayoko; Hirai, Jun; Aoyama, Hajime; Saio, Masanao; Yoshimi, Naoki; Kinjo, Takeshi; Miyagi, Kazuya; Haranaga, Shusaku; Higa, Futoshi; Tateyama, Masao; Fujita, Jiro

    2015-01-01

    We herein describe the case of a 63-year-old man who died from relapsed epidermal growth factor receptor gene (EGFR) exon 19 deletion lung adenocarcinoma treated with erlotinib. According to the autopsy results, he was confirmed to have small cell carcinoma without the EGFR T790M mutation in his pancreas and left kidney metastatic specimens, while the adenocarcinoma metastatic lesion in his right kidney had the EGFR T790M mutation; both retained the somatic EGFR exon 19 deletion. We herein report an autopsy case of resistance to an EGFR tyrosine kinase inhibitor via small cell carcinoma transformation and the EGFRT790M mutation in separate metastatic organs. PMID:26424310

  4. Niclosamide inhibits epithelial-mesenchymal transition and tumor growth in lapatinib-resistant human epidermal growth factor receptor 2-positive breast cancer.

    PubMed

    Liu, Junjun; Chen, Xiaosong; Ward, Toby; Mao, Yan; Bockhorn, Jessica; Liu, Xiaofei; Wang, Gen; Pegram, Mark; Shen, Kunwei

    2016-02-01

    Acquired resistance to lapatinib, a human epidermal growth factor receptor 2 kinase inhibitor, remains a clinical problem for women with human epidermal growth factor receptor 2-positive advanced breast cancer, as metastasis is commonly observed in these patients. Niclosamide, an anti-helminthic agent, has recently been shown to exhibit cytotoxicity to tumor cells with stem-like characteristics. This study was designed to identify the mechanisms underlying lapatinib resistance and to determine whether niclosamide inhibits lapatinib resistance by reversing epithelial-mesenchymal transition. Here, two human epidermal growth factor receptor 2-positive breast cancer cell lines, SKBR3 and BT474, were exposed to increasing concentrations of lapatinib to establish lapatinib-resistant cultures. Lapatinib-resistant SKBR3 and BT474 cells exhibited up-regulation of the phenotypic epithelial-mesenchymal transition markers Snail, vimentin and α-smooth muscle actin, accompanied by activation of nuclear factor-кB and Src and a concomitant increase in stem cell marker expression (CD44(high)/CD24(low)), compared to naive lapatinib-sensitive SKBR3 and BT474 cells, respectively. Interestingly, niclosamide reversed epithelial-mesenchymal transition, induced apoptosis and inhibited cell growth by perturbing aberrant signaling pathway activation in lapatinib-resistant human epidermal growth factor receptor 2-positive cells. The ability of niclosamide to alleviate stem-like phenotype development and invasion was confirmed. Collectively, our results demonstrate that lapatinib resistance correlates with epithelial-mesenchymal transition and that niclosamide inhibits lapatinib-resistant cell viability and epithelial-mesenchymal transition. These findings suggest a role of niclosamide or derivatives optimized for more favorable bioavailability not only in reversing lapatinib resistance but also in reducing metastatic potential during the treatment of human epidermal growth factor receptor

  5. miR-134 inhibits non-small cell lung cancer growth by targeting the epidermal growth factor receptor.

    PubMed

    Qin, Qin; Wei, Furong; Zhang, Jianbo; Wang, Xingwu; Li, Baosheng

    2016-10-01

    The epidermal growth factor receptor (EGFR) is frequently activated in a wide range of solid tumours and represents an important therapeutic target. MicroRNAs (miRNAs) have recently been recognized as a rational and potential modality for anti-EGFR therapies. However, more EGFR-targeting miRNAs need to be explored. In this study, we identified a novel EGFR-targeting miRNA, miRNA-134 (miR-134), in non-small-cell lung cancer (NSCLC) cell lines. Luciferase assays confirmed that EGFR is a direct target of miR-134. In addition, the overexpression of miR-134 inhibited EGFR-related signaling and suppressed NSCLC cells proliferation by inducing cell cycle arrest and/or apoptosis, suggesting that miR-134 functions as a tumour suppressor in NSCLC. Further mechanistic investigation including RNAi and rescue experiments suggested that the down-regulation of EGFR by miR-134 partially contributes to the antiproliferative role of miR-134. Last, in vivo experiments demonstrated that miR-134 suppressed tumour growth of A549 xenograft in nude mice. Taken together, our findings suggest that miR-134 inhibits non-small cell lung cancer growth by targeting the EGFR.

  6. Cross-linking of epidermal growth factor receptors in intact cells: detection of initial stages of receptor clustering and determination of molecular weight of high-affinity receptors

    SciTech Connect

    Fanger, B.O.; Austin, K.S.; Earp, H.S.; Cidlowski, J.A.

    1986-10-21

    A method was developed to label epidermal growth factor (EGF) receptors with /sup 125/I-EGF in whole cells using chemical cross-linking reagents. Polyacrylamide gel electrophoresis resolved an M/sub r/ approx. 180,000 EGF-receptor complex and larger M/sub r/ greater than or equal to 360,000 aggregates. The formation of the larger complexes was timed and temperature dependent and appeared to represent the initial events of EGF receptor clustering. Alteration of the ratio of /sup 125/I-EGF-labeled high- and low- affinity complexes by competition with unlabeled EGF or by induction of additional high-affinity sites with dexamethasone suggested that both sites were represented by the M/sub r/ approx. 180,000 /sup 125/I-EGF-receptor complexes. Digestion of cells before cross-linking detected a small population of trypsin-resistant M/sub r/ approx. 180,000 receptors, which could represent previously described cryptic and/or high-affinity receptors. Few of the M/sub r/ approx. 360,000 receptors were trypsin resistant. Glucocorticoid induction of high-affinity EGF receptors failed to induce detectable changes in the microclustering of EGF receptors but did result in a 50% increase in EGF-induced receptor phosphorylation in HeLa S/sub 3/ cell membranes at 4/sup 0/C. Thus, glucocorticoids increase high-affinity EGF binding sites, EGF-induced receptor phosphorylation, and cell growth.

  7. Quantitative in vivo immunohistochemistry of epidermal growth factor receptor using a receptor concentration imaging approach.

    PubMed

    Samkoe, Kimberley S; Tichauer, Kenneth M; Gunn, Jason R; Wells, Wendy A; Hasan, Tayyaba; Pogue, Brian W

    2014-12-15

    As receptor-targeted therapeutics become increasingly used in clinical oncology, the ability to quantify protein expression and pharmacokinetics in vivo is imperative to ensure successful individualized treatment plans. Current standards for receptor analysis are performed on extracted tissues. These measurements are static and often physiologically irrelevant; therefore, only a partial picture of available receptors for drug targeting in vivo is provided. Until recently, in vivo measurements were limited by the inability to separate delivery, binding, and retention effects, but this can be circumvented by a dual-tracer approach for referencing the detected signal. We hypothesized that in vivo receptor concentration imaging (RCI) would be superior to ex vivo immunohistochemistry (IHC). Using multiple xenograft tumor models with varying EGFR expression, we determined the EGFR concentration in each model using a novel targeted agent (anti-EGFR affibody-IRDye800CW conjugate) along with a simultaneously delivered reference agent (control affibody-IRDye680RD conjugate). The RCI-calculated in vivo receptor concentration was strongly correlated with ex vivo pathologist-scored IHC and computer-quantified ex vivo immunofluorescence. In contrast, no correlation was observed with ex vivo Western blot analysis or in vitro flow-cytometry assays. Overall, our results argue that in vivo RCI provides a robust measure of receptor expression equivalent to ex vivo immunostaining, with implications for use in noninvasive monitoring of therapy or therapeutic guidance during surgery. PMID:25344226

  8. Epidermal growth factor receptor kinase domain mutations are rare in salivary gland carcinomas

    PubMed Central

    Dahse, R; Driemel, O; Schwarz, S; Dahse, J; Kromeyer-Hauschild, K; Berndt, A; Kosmehl, H

    2009-01-01

    Activating mutations within the epidermal growth factor (EGFR) tyrosine kinase domain identify non-small cell lung cancer patients with improved clinical response to tyrosine kinase inhibitor therapy. Recently, we identified two EGFR mutations in a cohort of 25 salivary gland carcinomas (SGCs) by screening the tumour samples for the both most common hotspot mutations in exons 19 and 21 by allele-specific PCR. Here, we present a comprehensive sequencing analysis of the entire critical EGFR tyrosine kinase domain in 65 SGC of the main histopathological types. We found EGFR mutations in the tyrosine kinase domain to be a rare event in SGCs. No additional mutations other than the two known exon 19 deletions (c.2235_2249del15) in a mucoepidermoid carcinoma and an adenoid cystic carcinoma have been detected. Other putative predictive markers for EGFR-targeted therapy in SGCs might be relevant and should be investigated. PMID:19174819

  9. Dual silencing of insulin-like growth factor-I receptor and epidermal growth factor receptor in colorectal cancer cells is associated with decreased proliferation and enhanced apoptosis.

    PubMed

    Kaulfuss, Silke; Burfeind, Peter; Gaedcke, Jochen; Scharf, Jens-Gerd

    2009-04-01

    Overexpression and activation of tyrosine kinase receptors are common features of colorectal cancer. Using the human colorectal cancer cell lines DLD-1 and Caco-2, we evaluated the role of the insulin-like growth factor-I (IGF-I) receptor (IGF-IR) and epidermal growth factor receptor (EGFR) in cellular functions of these cells. We used the small interfering RNA (siRNA) technology to specifically down-regulate IGF-IR and EGFR expression. Knockdown of IGF-IR and EGFR resulted in inhibition of cell proliferation of DLD-1 and Caco-2 cells. An increased rate of apoptosis was associated with siRNA-mediated silencing of IGF-IR and EGFR as assessed by activation of caspase-3/caspase-7. The combined knockdown of both EGFR and IGF-IR decreased cell proliferation and induced cell apoptosis more effectively than did silencing of either receptor alone. Comparable effects on cell proliferation and apoptosis were observed after single and combinational treatment of cells by the IGF-IR tyrosine kinase inhibitor NVP-AEW541 and/or the EGFR tyrosine kinase inhibitor erlotinib. Combined IGF-IR and EGFR silencing by either siRNAs or tyrosine kinase inhibitors diminished the phosphorylation of downstream signaling pathways AKT and extracellular signal-regulated kinase (ERK)-1/2 more effectively than did the single receptor knockdown. Single IGF-IR knockdown inhibited IGF-I-dependent phosphorylation of AKT but had no effect on IGF-I- or EGF-dependent phosphorylation of ERK1/2, indicating a role of EGFR in ligand-dependent ERK1/2 phosphorylation. The present data show that inhibition of the IGF-IR transduction cascade augments the antipoliferative and proapoptotic effects of EGFR inhibition in colorectal cancer cells. A clinical application of combination therapy targeting both EGFR and IGF-IR could be a promising therapeutic strategy.

  10. Cross-talk between the calcium-sensing receptor and the epidermal growth factor receptor in Rat-1 fibroblasts

    SciTech Connect

    Tomlins, Scott A.; Bolllinger, Nikki; Creim, Jeffrey; Rodland, Karin D. . E-mail: Karin.rodland@pnl.gov

    2005-08-15

    The calcium-sensing receptor (CaR) is a G-protein-coupled receptor that is activated by extracellular calcium (Ca {sub o} {sup 2+}). Rat-1 fibroblasts have been shown to proliferate and increase ERK activity in response to elevation of [Ca{sup 2+}] {sub o}, and these responses are dependent on functional CaR expression. In this report, we examined the role of cross-talk between the CaR and the epidermal growth factor receptor (EGFR) in mediating these responses in Rat-1 cells. This report shows that AG1478, a specific inhibitor of the EGFR kinase, significantly inhibits the increase in proliferation induced by elevated Ca {sub o} {sup 2+}. Furthermore, we show that AG1478 acts downstream or separately from G protein subunit activation of phospholipase C. AG1478 significantly inhibits Ca {sub o} {sup 2+}-stimulated ERK phosphorylation and in vitro kinase activity. A similar inhibition of ERK phosphorylation was observed in response to the inhibitor AG494. In addition, treatment with inhibitors of metalloproteases involved in shedding of membrane anchored EGF family ligands substantially inhibited the increase in ERK activation in response to elevated Ca {sub o} {sup 2+}. This is consistent with the known expression of TGF{alpha} by Rat-1 cells. These results indicate that EGFR transactivation is an important component of the CaR-mediated response to increased Ca {sub o} {sup 2+} in Rat-1 fibroblasts and most likely involves CaR-mediated induction of regulated proteolysis and ligand shedding.

  11. Anti-epidermal growth factor receptor conjugated mesoporous zinc oxide nanofibers for breast cancer diagnostics

    NASA Astrophysics Data System (ADS)

    Ali, Md. Azahar; Mondal, Kunal; Singh, Chandan; Dhar Malhotra, Bansi; Sharma, Ashutosh

    2015-04-01

    We report the fabrication of an efficient, label-free, selective and highly reproducible immunosensor with unprecedented sensitivity (femto-molar) to detect a breast cancer biomarker for early diagnostics. Mesoporous zinc oxide nanofibers (ZnOnFs) are synthesized by electrospinning technique with a fiber diameter in the range of 50-150 nm. Fragments of ZnOnFs are electrophoretically deposited on an indium tin oxide glass substrate and conjugated via covalent or electrostatic interactions with a biomarker (anti-ErbB2; epidermal growth factor receptor 2). Oxygen plasma treatment of the carbon doped ZnOnFs generates functional groups (-COOH, -OH, etc.) that are effective for the conjugation of anti-ErbB2. ZnOnFs without plasma treatment that conjugate via electrostatic interactions were also tested for comparison. Label-free detection of the breast cancer biomarker by this point-of-care device is achieved by an electrochemical impedance technique that has high sensitivity (7.76 kΩ μM-1) and can detect 1 fM (4.34 × 10-5 ng mL-1) concentration. The excellent impedimetric response of this immunosensor provides a fast detection (128 s) in a wide detection test range (1.0 fM-0.5 μM). The oxy-plasma treated ZnOnF immunoelectrode shows a higher association constant (404.8 kM-1 s-1) indicating a higher affinity towards the ErbB2 antigen compared to the untreated ZnOnF immunoelectrode (165.6 kM-1 s-1). This sensor is about an order of magnitude more sensitive than the best demonstrated in the literature based on different nanomaterials and about three orders of magnitude better than the ELISA standard for breast cancer biomarker detection. This proposed point-of-care cancer diagnostic offers several advantages, such as higher stability, rapid monitoring, simplicity, cost-effectiveness, etc., and should prove to be useful for the detection of other bio- and cancer markers.We report the fabrication of an efficient, label-free, selective and highly reproducible immunosensor

  12. Selected Reaction Monitoring (SRM) Analysis of Epidermal Growth Factor Receptor (EGFR) in Formalin Fixed Tumor Tissue

    PubMed Central

    2012-01-01

    Background Analysis of key therapeutic targets such as epidermal growth factor receptor (EGFR) in clinical tissue samples is typically done by immunohistochemistry (IHC) and is only subjectively quantitative through a narrow dynamic range. The development of a standardized, highly-sensitive, linear, and quantitative assay for EGFR for use in patient tumor tissue carries high potential for identifying those patients most likely to benefit from EGFR-targeted therapies. Methods A mass spectrometry-based Selected Reaction Monitoring (SRM) assay for the EGFR protein (EGFR-SRM) was developed utilizing the Liquid Tissue®-SRM technology platform. Tissue culture cells (n = 4) were analyzed by enzyme-linked immunosorbent assay (ELISA) to establish quantitative EGFR levels. Matching formalin fixed cultures were analyzed by the EGFR-SRM assay and benchmarked against immunoassay of the non-fixed cultured cells. Xenograft human tumor tissue (n = 10) of non-small cell lung cancer (NSCLC) origin and NSCLC patient tumor tissue samples (n = 23) were microdissected and the EGFR-SRM assay performed on Liquid Tissue lysates prepared from microdissected tissue. Quantitative curves and linear regression curves for correlation between immunoassay and SRM methodology were developed in Excel. Results The assay was developed for quantitation of a single EGFR tryptic peptide for use in FFPE patient tissue with absolute specificity to uniquely distinguish EGFR from all other proteins including the receptor tyrosine kinases, IGF-1R, cMet, Her2, Her3, and Her4. The assay was analytically validated against a collection of tissue culture cell lines where SRM analysis of the formalin fixed cells accurately reflects EGFR protein levels in matching non-formalin fixed cultures as established by ELISA sandwich immunoassay (R2 = 0.9991). The SRM assay was applied to a collection of FFPE NSCLC xenograft tumors where SRM data range from 305amol/μg to 12,860amol/μg and are consistent

  13. Epidermal growth factor receptor gene polymorphisms are associated with prognostic features of breast cancer

    PubMed Central

    2014-01-01

    Background The epidermal growth factor receptor (EGFR) is differently expressed in breast cancer, and its presence may favor cancer progression. We hypothesized that two EGFR functional polymorphisms, a (CA)n repeat in intron 1, and a single nucleotide polymorphism, R497K, may affect EGFR expression and breast cancer clinical profile. Methods The study population consisted of 508 Brazilian women with unilateral breast cancer, and no distant metastases. Patients were genotyped for the (CA)n and R497K polymorphisms, and the associations between (CA)n polymorphism and EGFR transcript levels (n = 129), or between either polymorphism and histopathological features (n = 505) were evaluated. The REMARK criteria of tumor marker evaluation were followed. Results (CA)n lengths ranged from 14 to 24 repeats, comprehending 11 alleles and 37 genotypes. The most frequent allele was (CA)16 (0.43; 95% CI = 0.40–0.46), which was set as the cut-off length to define the Short allele. Variant (CA)n genotypes had no significant effect in tumoral EGFR mRNA levels, but patients with two (CA)n Long alleles showed lower chances of being negative for progesterone receptor (ORadjusted = 0.42; 95% CI = 0.19–0.91). The evaluation of R497K polymorphism indicated a frequency of 0.21 (95% CI = 0.19 – 0.24) for the variant (Lys) allele. Patients with variant R497K genotypes presented lower proportion of worse lymph node status (pN2 or pN3) when compared to the reference genotype Arg/Arg (ORadjusted = 0.32; 95% CI = 0.17–0.59), which resulted in lower tumor staging (ORadjusted = 0.34; 95% CI = 0.19-0.63), and lower estimated recurrence risk (OR = 0.50; 95% CI = 0.30-0.81). The combined presence of both EGFR polymorphisms (Lys allele of R497K and Long/Long (CA)n) resulted in lower TNM status (ORadjusted = 0.22; 95% CI = 0.07-0.75) and lower ERR (OR = 0.25; 95% CI = 0.09-0.71). When tumors were stratified according to biological

  14. Acquired resistance of non-small cell lung cancer to epidermal growth factor receptor tyrosine kinase inhibitors.

    PubMed

    Nurwidya, Fariz; Takahashi, Fumiyuki; Murakami, Akiko; Kobayashi, Isao; Kato, Motoyasu; Shukuya, Takehito; Tajima, Ken; Shimada, Naoko; Takahashi, Kazuhisa

    2014-03-01

    Activation of epidermal growth factor receptor (EGFR) triggers anti-apoptotic signaling, proliferation, angiogenesis, invasion, metastasis, and drug resistance, which leads to development and progression of human epithelial cancers, including non-small cell lung cancer (NSCLC). Inhibition of EGFR by tyrosine kinase inhibitors such as gefitinib and erlotinib has provided a new hope for the cure of NSCLC patients. However, acquired resistance to gefitinib and erlotinib via EGFR-mutant NSCLC has occurred through various molecular mechanisms such as T790M secondary mutation, MET amplification, hepatocyte growth factor (HGF) overexpression, PTEN downregulation, epithelial-mesenchymal transition (EMT), and other mechanisms. This review will discuss the biology of receptor tyrosine kinase inhibition and focus on the molecular mechanisms of acquired resistance to tyrosine kinase inhibitors of EGFR-mutant NSCLC.

  15. Honokiol inhibits the growth of head and neck squamous cell carcinoma by targeting epidermal growth factor receptor.

    PubMed

    Singh, Tripti; Gupta, Nirzari A; Xu, Su; Prasad, Ram; Velu, Sadanandan E; Katiyar, Santosh K

    2015-08-28

    Here, we report the chemotherapeutic effect of honokiol, a phytochemical from Magnolia plant, on human head and neck squamous cell carcinoma (HNSCC). Treatment of HNSCC cell lines from different sub-sites, SCC-1 (oral cavity), SCC-5 (larynx), OSC-19 (tongue) and FaDu (pharynx) with honokiol inhibited their cell viability, which was associated with the: (i) induction of apoptosis, (ii) correction of dysregulatory cell cycle proteins of G0/G1 phase. Honokiol decreased the expression levels of epidermal growth factor receptor (EGFR), mTOR and their downstream signaling molecules. Treatment of FaDu and SCC-1 cell lines with rapamycin, an inhibitor of mTOR pathway, also reduced cell viability of HNSCC cells. Administration of honokiol by oral gavage (100 mg/kg body weight) significantly (P < 0.01-0.001) inhibited the growth of SCC-1 and FaDu xenografts in athymic nude mice, which was associated with: (i) inhibition of tumor cell proliferation, (ii) induction of apoptosis, (iii) reduced expressions of cyclins and Cdks, and (iv) inhibition of EGFR signaling pathway. Molecular docking analysis of honokiol in EGFR binding site indicated that the chemotherapeutic effect of honokiol against HNSCC is mediated through its firm binding with EGFR, which is better than that of gefitinib, a commonly used drug for HNSCC treatment.

  16. Poor response to gefitinib in lung adenocarcinoma with concomitant epidermal growth factor receptor mutation and anaplastic lymphoma kinase rearrangement.

    PubMed

    Zhou, Jianya; Zheng, Jing; Zhao, Jing; Sheng, Yihong; Ding, Wei; Zhou, Jianying

    2015-03-01

    A patient presenting with concomitant epidermal growth factor receptor (EGFR) mutation and anaplastic lymphoma kinase (ALK) translocation is rare. We report a non-small cell lung cancer (NSCLC) patient with concomitant ALK rearrangement and exon 19 (E746-A750del) EGFR mutation. The ALK rearrangement was confirmed not only in the primary tumor biopsy specimen, but also in the pleural effusion cell block by reverse transcriptase-polymerase chain reaction (RT-PCR), Ventana ALK immunohistochemistry assay, and fluorescence in situ hybridization. No clinical benefit using chemotherapy or EGFR tyrosine kinase inhibitor gefitinib was obtained in this case.

  17. Markers of angiogenesis and epidermal growth factor receptor signalling in patients with pancreatic and gastroesophageal junction cancer.

    PubMed

    Rohrberg, Kristoffer Staal; Skov, Birgit Guldhammer; Lassen, Ulrik; Christensen, Ib Jarle; Høyer-Hansen, Gunilla; Buysschaert, Ian; Pappot, Helle

    2010-01-01

    The epidermal growth factor receptor (EGFR) and angiogenesis are well established targets in anti-cancer therapy. Several targeted anti-cancer therapies are in clinical trials in pancreatic and gastroesophageal (GEJ) cancer. However, many patients do not respond to these targeted therapies and there is therefore an increasing need for biomarkers for selection of patients to these therapies. We investigated the expression of EGFR, vascular endothelial growth factor A (VEGF-A), and VEGF receptor 2 (VEGFR-2) in tumour tissue by immunohistochemistry, and soluble EGFR (sEGFR), soluble VEGFR-2 (sVEGFR-2), basic fibroblast growth factor (bFGF), placental growth factor (PlGF), plasminogen activator inhibitor 1 (PAI-1), and different forms of the urokinase plasminogen activator receptor (uPAR): uPAR (I), uPAR (I-III), and uPAR (I-III)+(II-III) in plasma by quantitative immunoassays in 14 patients with pancreatic and GEJ cancer. We found expression in tumour tissue and the plasma levels to be similar to those found in patients with other tumour types. No correlation was found between the blood levels of soluble receptors and the corresponding tumour tissue levels. We conclude that these markers are present in pancreatic and GEJ cancer patients, and could be investigated further as predictive biomarkers in such patients treated with EGFR or angiogenesis targeted therapies.

  18. Epidermal growth factor receptor expression in radiation-induced dog lung tumors by immunocytochemical localization

    SciTech Connect

    Leung, F.L.; Park, J.F.; Dagle, G.E.

    1993-06-01

    In studies to determine the role of growth factors in radiation-induced lung cancer, epidermal growth factor (EGFR) expression was examined by immunocytochemistry in 51 lung tumors from beagle dogs exposed to inhaled plutonium; 21 of 51 (41%) tumors were positive for EGFR. The traction of tumors positive for EGFR and the histological type of EGFR-positive tumors in the plutonium-exposed dogs were not different from spontaneous dog lung tumors, In which 36% were positive for EGFR. EGFR involvement in Pu-induced lung tumors appeared to be similar to that in spontaneous lung tumors. However, EGFR-positive staining was observed in only 1 of 16 tumors at the three lowest Pu exposure levels, compared to 20 of 35 tumors staining positive at the two highest Pu exposure levels. The results in dogs were in good agreement with the expression of EGFR reported in human non-small cell carcinoma of the lung, suggesting that Pu-induced lung tumors in the dog may be a suitable animal model to investigate the role of EGFR expression in lung carcinogenesis. In humans, EGFR expression in lung tumors has been primarily related to histological tumor types. In individual dogs with multiple primary lung tumors, the tumors were either all EGFR positive or EGFR negative, suggesting that EGFR expression may be related to the response of the individual dog as well as to the histological type of tumor.

  19. The coexpression and prognostic significance of c-MET, fibroblast growth factor receptor 2, and human epidermal growth factor receptor 2 in resected gastric cancer: a retrospective study

    PubMed Central

    Jia, Yong-Xu; Li, Teng-Fei; Zhang, Dan-Dan; Fan, Zong-Min; Fan, Hui-Jie; Yan, Jie; Chen, Li-Juan; Tang, Hong; Qin, Yan-Ru; Li, Xing-Ya

    2016-01-01

    Molecular-targeted therapy against tyrosine kinase receptors (RTKs) plays an important role in gastric cancer (GC) treatment. Understanding the correlation between RTK coexpression could better guide clinical drug use. In the present study, the coexpression status of c-MET, fibroblast growth factor receptor 2 (FGFR2), and human epidermal growth factor receptor 2 (HER2) in human GC and their clinical significance in clinical therapy were explored. Immunohistochemical (IHC) staining, quantitative real-time polymerase chain reaction and fluorescent in situ hybridization were performed in 143 cases of GC who had undergone gastrectomy without preoperative chemoradiotherapy. Their association with clinicopathological features and clinical prognosis was analyzed. The frequencies of c-MET, FGFR2, and HER2 overexpression were 47.6% (68/143), 34.3% (49/143), and 10.5% (15/143), respectively. In the RTK coexpression study, 30.1% of patients (43/143) were positive for only one RTK, 25.8% (37/143) were positive for two RTKs, 3.5% (5/143) had triple-positive status, and 40.6% (58/143) had triple-negative status. In survival analysis, the overexpression of c-MET, FGFR2, and HER2 were significantly associated with overall survival (OS) (P=0.018, 0.004, and 0.049, respectively). In coexpression analysis, patients with triple-positive GC had the poorest OS (P=0.013). In conclusion, RTK coexpression is significantly associated with poor clinical outcome in GC. PMID:27729801

  20. Leptin stimulates endothelin-1 expression via extracellular signal-regulated kinase by epidermal growth factor receptor transactivation in rat aortic smooth muscle cells.

    PubMed

    Chao, Hung-Hsing; Hong, Hong-Jye; Liu, Ju-Chi; Lin, Jia-Wei; Chen, Yen-Ling; Chiu, Wen-Ta; Wu, Chieh-Hsi; Shyu, Kou-Gi; Cheng, Tzu-Hurng

    2007-11-14

    Obesity is a major risk factor for the development of hypertension. Recent studies have suggested that leptin, a 167-amino acid peptide hormone produced by white adipose tissue, is related to the pathogenesis of obesity-related hypertension. However, the signaling mechanisms underlying the effects of leptin remain to be extensively examined. In this study, we found that leptin induced extracellular signal-regulated kinase phosphorylation and endothelin-1 expression in rat aortic smooth muscle cells. Both PD98059 and U0126, inhibitors of the upstream activator of mitogen-activated protein kinase kinase, inhibited augmentation of endothelin-1 expression stimulated with leptin. Leptin induced significant tyrosine phosphorylation of epidermal growth factor receptor, which was significantly attenuated by two inhibitors, an epidermal growth factor receptor tyrosine kinase inhibitor, AG1478, and a broad-spectrum matrix metalloproteinase inhibitor, GM6001. This indicates that the pathway of epidermal growth factor receptor transactivation induced by leptin is dependent on proteolytically released epidermal growth factor receptor ligands. Pretreatment of cells with AG1478 significantly reduced the degree of phosphorylation of extracellular signal-regulated kinase and endothelin-1 expression. Our results reveal that epidermal growth factor receptor transactivation is involved in the leptin signaling pathway in vascular smooth muscle cells, which may be related to the increased risk of hypertension and other cardiovascular diseases in obese subjects. PMID:17678888

  1. Muscarinic Type 3 Receptor Induces Cytoprotective Signaling in Salivary Gland Cells through Epidermal Growth Factor Receptor Transactivation

    PubMed Central

    Kajiya, Mikihito; Ichimonji, Isao; Min, Christine; Zhu, Tongbo; Jin, Jun-O; Yu, Qing; Almazrooa, Soulafa A.; Cha, Seunghee

    2012-01-01

    Muscarinic type 3 receptor (M3R) plays a pivotal role in the induction of glandular fluid secretions. Although M3R is often the target of autoantibodies in Sjögren's syndrome (SjS), chemical agonists for M3R are clinically used to stimulate saliva secretion in patients with SjS. Aside from its activity in promoting glandular fluid secretion, however, it is unclear whether activation of M3R is related to other biological events in SjS. This study aimed to investigate the cytoprotective effect of chemical agonist-mediated M3R activation on apoptosis induced in human salivary gland (HSG) cells. Carbachol (CCh), a muscarinic receptor-specific agonist, abrogated tumor necrosis factor α/interferon γ-induced apoptosis through pathways involving caspase 3/7, but its cytoprotective effect was decreased by a M3R antagonist, a mitogen-activated protein kinase kinase/extracellular signal-regulated kinase (ERK) inhibitor, a phosphatidylinositol 3-kinase/Akt inhibitor, or an epidermal growth factor receptor (EGFR) inhibitor. Ligation of M3R with CCh transactivated EGFR and phosphorylated ERK and Akt, the downstream targets of EGFR. Inhibition of intracellular calcium release or protein kinase C δ, both of which are involved in the cell signaling of M3R-mediated fluid secretion, did not affect CCh-induced ERK or Akt phosphorylation. CCh stimulated Src phosphorylation and binding to EGFR. A Src inhibitor attenuated the CCh/M3R-induced cytoprotective effect and EGFR transactivation cascades. Overall, these results indicated that CCh/M3R induced transactivation of EGFR through Src activation leading to ERK and Akt phosphorylation, which in turn suppressed caspase 3/7-mediated apoptotic signals in HSG cells. This study, for the first time, proposes that CCh-mediated M3R activation can promote not only fluid secretion but also survival of salivary gland cells in the inflammatory context of SjS. PMID:22511543

  2. Vandetanib (ZD6474), a dual inhibitor of vascular endothelial growth factor receptor (VEGFR) and epidermal growth factor receptor (EGFR) tyrosine kinases: current status and future directions.

    PubMed

    Morabito, Alessandro; Piccirillo, Maria Carmela; Falasconi, Fabiano; De Feo, Gianfranco; Del Giudice, Antonia; Bryce, Jane; Di Maio, Massimo; De Maio, Ermelinda; Normanno, Nicola; Perrone, Francesco

    2009-04-01

    Vandetanib is a novel, orally available inhibitor of different intracellular signaling pathways involved in tumor growth, progression, and angiogenesis: vascular endothelial growth factor receptor-2, epidermal growth factor receptor, and REarranged during Transfection tyrosine kinase activity. Phase I clinical trials have shown that vandetanib is well tolerated as a single agent at daily doses < or =300 mg. In the phase II setting, negative results were observed with vandetanib in small cell lung cancer, metastatic breast cancer, and multiple myeloma. In contrast, three randomized phase II studies showed that vandetanib prolonged the progression-free survival (PFS) time of patients with non-small cell lung cancer (NSCLC) as a single agent when compared with gefitinib or when added to chemotherapy. Rash, diarrhea, hypertension, fatigue, and asymptomatic QTc prolongation were the most common adverse events. Antitumor activity was also observed in medullary thyroid cancer. Four randomized phase III clinical trials in NSCLC are exploring the efficacy of vandetanib in combination with docetaxel, the Zactima in cOmbination with Docetaxel In non-small cell lung Cancer (ZODIAC) trial, or with pemetrexed, the Zactima Efficacy with Alimta in Lung cancer (ZEAL) trial, or as a single agent, the Zactima Efficacy when Studied versus Tarceva (ZEST) and the Zactima Efficacy trial for NSCLC Patients with History of EGFR-TKI chemo-Resistance (ZEPHYR) trials. Based on a press release by the sponsor of these trials, the PFS time was longer with vandetanib in the ZODIAC and ZEAL trials; the ZEST trial was negative for its primary superiority analysis, but was successful according to a preplanned noninferiority analysis of PFS. Ongoing phase II and III clinical trials will better define the appropriate schedule, the optimal setting of evaluation, and the safety of long-term use of vandetanib.

  3. Vandetanib (ZD6474), a dual inhibitor of vascular endothelial growth factor receptor (VEGFR) and epidermal growth factor receptor (EGFR) tyrosine kinases: current status and future directions.

    PubMed

    Morabito, Alessandro; Piccirillo, Maria Carmela; Falasconi, Fabiano; De Feo, Gianfranco; Del Giudice, Antonia; Bryce, Jane; Di Maio, Massimo; De Maio, Ermelinda; Normanno, Nicola; Perrone, Francesco

    2009-04-01

    Vandetanib is a novel, orally available inhibitor of different intracellular signaling pathways involved in tumor growth, progression, and angiogenesis: vascular endothelial growth factor receptor-2, epidermal growth factor receptor, and REarranged during Transfection tyrosine kinase activity. Phase I clinical trials have shown that vandetanib is well tolerated as a single agent at daily doses < or =300 mg. In the phase II setting, negative results were observed with vandetanib in small cell lung cancer, metastatic breast cancer, and multiple myeloma. In contrast, three randomized phase II studies showed that vandetanib prolonged the progression-free survival (PFS) time of patients with non-small cell lung cancer (NSCLC) as a single agent when compared with gefitinib or when added to chemotherapy. Rash, diarrhea, hypertension, fatigue, and asymptomatic QTc prolongation were the most common adverse events. Antitumor activity was also observed in medullary thyroid cancer. Four randomized phase III clinical trials in NSCLC are exploring the efficacy of vandetanib in combination with docetaxel, the Zactima in cOmbination with Docetaxel In non-small cell lung Cancer (ZODIAC) trial, or with pemetrexed, the Zactima Efficacy with Alimta in Lung cancer (ZEAL) trial, or as a single agent, the Zactima Efficacy when Studied versus Tarceva (ZEST) and the Zactima Efficacy trial for NSCLC Patients with History of EGFR-TKI chemo-Resistance (ZEPHYR) trials. Based on a press release by the sponsor of these trials, the PFS time was longer with vandetanib in the ZODIAC and ZEAL trials; the ZEST trial was negative for its primary superiority analysis, but was successful according to a preplanned noninferiority analysis of PFS. Ongoing phase II and III clinical trials will better define the appropriate schedule, the optimal setting of evaluation, and the safety of long-term use of vandetanib. PMID:19349511

  4. Human epidermal growth factor receptor 2 positive (HER2+) metastatic breast cancer: how the latest results are improving therapeutic options

    PubMed Central

    Jiang, Hanfang; Rugo, Hope S.

    2015-01-01

    Human epidermal growth factor receptor 2 positive (HER2+) metastatic breast cancer (MBC) remains an incurable disease, and approximately 25% of patients with HER2+ early breast cancer still relapse after adjuvant trastuzumab-based treatment. HER2 is a validated therapeutic target that remains relevant throughout the disease process. Recently, a number of novel HER2 targeted agents have become available, including lapatinib (a small molecule tyrosine kinase inhibitor of both HER2 and the epidermal growth factor receptor), pertuzumab (a new anti-HER2 monoclonal antibody) and ado-trastuzumab emtansine (T-DM1, a novel antibody–drug conjugate), which provide additional treatment options for patients with HER2+ MBC. The latest clinical trials have demonstrated improved outcome with treatment including pertuzumab or T-DM1 compared with standard HER2 targeted therapy. Here we review the clinical development of approved and investigational targeted agents for the treatment of HER2+ MBC, summarize the latest results of important clinical trials supporting use of these agents in the treatment of HER2+ MBC, and discuss how these results impact therapeutic options in clinical practice. PMID:26557900

  5. The Mitogenic Potential of Heparin-Binding Epidermal Growth Factor in the Human Endometrium Is Mediated by the Epidermal Growth Factor Receptor and Is Modulated by Tumor Necrosis Factor

    PubMed Central

    CHOBOTOVA, KATYA; MUCHMORE, MARY-ELIZABETH; CARVER, JANET; YOO, HYUNG-J; MANEK, SANJIV; GULLICK, WILLIAM J.; BARLOW, DAVID H.; MARDON, HELEN J.

    2006-01-01

    Heparin-binding epidermal growth factor (HB-EGF), a member of the epidermal growth factor (EGF) family, is implicated in a variety of biological processes, including reproduction. Previous studies describe increased levels of HB-EGF in the human endometrium during the midsecretory stage of the menstrual cycle, suggesting a function for HB-EGF in implantation of the human blastocyst. Here we have investigated the expression and function of the soluble and transmembrane forms of HB-EGF in the human endometrium. We show that the expression of the transmembrane form of HB-EGF in the human endometrium is modulated according to the stage of the menstrual cycle. We present data demonstrating that both the soluble and transmembrane forms of HB-EGF induce DNA synthesis in human endometrial stromal cells. Furthermore, TNFα has a cooperative effect on HB-EGF, EGF, TGFα, and betacellulin-induced DNA synthesis in stromal cells, suggesting roles for the EGF family and TNFα in regeneration and maturation of human endometrium. Induction of DNA synthesis by HB-EGF and its modulation by TNFα in endometrial stromal cells are mediated by the EGF receptor and not the HB-EGF receptor ErbB4. Our data suggest key functions for HB-EGF, TNFα, and the EGF receptor in endometrial maturation, via autocrine/paracrine and juxtacrine pathways, in preparation for embryo implantation. PMID:12466384

  6. Platelet-activating factor induces ovine fetal pulmonary venous smooth muscle cell proliferation: role of epidermal growth factor receptor transactivation.

    PubMed

    Zhou, Weilin; Ibe, Basil O; Raj, J Usha

    2007-06-01

    We have previously reported that platelet-activating factor (PAF) is present in very high levels in the ovine fetal lung and circulation and that PAF serves as an important physiological vasoconstrictor of the pulmonary circulation in utero. However, it is not known whether PAF stimulates pulmonary vascular smooth muscle cell (SMC) proliferation. In this study, we used ovine fetal pulmonary venous SMCs as our model system to study the effects and mechanisms of action of PAF on SMC proliferation. We found that PAF induced SMC proliferation in a dose-dependent manner. PAF also stimulated activation of both ERK and p38 but not c-Jun NH(2) terminal kinase (JNK) mitogen-activated protein (MAP) kinase pathways. PAF (10 nM) induced phosphorylation of epidermal growth factor receptor (EGFR). Specific inhibition of EGFR by AG-1478 and by the expression of a dominant-negative EGFR mutant in SMCs attenuated PAF-stimulated cell proliferation. Inhibition of heparin-binding EGF-like growth factor (HB-EGF) release by CRM-197 and inhibition of matrix metalloproteinases (MMP) by GM-6001 abolished PAF-induced MAP kinase activation and cell proliferation. Increased alkaline phosphatase (AP) activity after PAF treatment in AP-HB-EGF fusion construct-transfected SMCs indicated that PAF induced the release of HB-EGF within 1 min. Gelatin zymography data showed that PAF stimulated MMP-2 activity and MMP-9 activity within 1 min. These results suggest that PAF promotes pulmonary vascular SMC proliferation via transactivation of EGFR through MMP activation and HB-EGF, resulting in p38 and ERK activation and that EGFR transactivation is essential for the mitogenic effect of PAF in pulmonary venous SMC. PMID:17322418

  7. Characterization of the expression and clinical features of epidermal growth factor receptor and vascular endothelial growth factor receptor-2 in esophageal carcinoma

    PubMed Central

    NIYAZ, MADINIYAT; ANWER, JURAT; LIU, HUI; ZHANG, LIWEI; SHAYHEDIN, ILYAR; AWUT, IDIRIS

    2015-01-01

    The present study aimed to understand the expression characteristics of epidermal growth factor receptor (EGFR) and vascular endothelial growth factor receptor-2 (VEGFR-2) in individuals of Uygur, Han and Kazak ethnicity with esophageal carcinoma in Xinjiang (China) and their interrelation analysis, and to investigate the expression differences in these genes between esophageal carcinoma and pericarcinoma tissue samples, and between the three ethnic groups. The expression levels of EGFR and VEGFR-2 from 119 pairs of esophageal carcinoma tissue and corresponding pericarcinoma tissue from Uygur, Han and Kazak patients with esophageal carcinoma were detected by immunohistochemistry following surgical resection, and an additional five carcinoma in situ specimens were also tested. The relative expression was analyzed among the ethnic groups and clinicopathological parameters. The positive rate of EGFR in esophageal carcinoma tissue from patients of Uygur, Han and Kazak heritage was 70.73, 68.42 and 67.5%, respectively. For VEGFR-2 the positive rate was 73.17, 68.42 and 67.5%, respectively. No significant difference was detected in their expression between the three ethnic groups (P>0.05); however, EGFR and VEGFR-2 overexpression were correlated with lymph node metastasis (P<0.05). VEGF expression was also correlated with the expression of VEGFR-2 in esophageal carcinoma tissues. EGFR was positive in carcinoma in situ samples, while VEGFR-2 was negative. The overexpression of EGFR is therefore an early event and may have a significant role in the progression of esophageal carcinoma pathogenesis. EGFR overexpression may correlate with the expression of VEGFR-2 in esophageal cancer. These results may aid the early diagnosis of esophageal cancer, and the development of individual target treatment in the future. PMID:26788193

  8. [Epidermic growth factor receptor (EGFR) in glioblastomas: the mechanism of tumorigenesis and its role as a therapeutic target].

    PubMed

    Zahonero, Cristina; Sepúlveda, Juan M; Sánchez-Gómez, Pilar

    2015-07-16

    A glioblastoma is a primary brain tumour that is very aggressive and resistant to conventional treatment with chemo- or radiotherapy. Given that epidermic growth factor receptor (EGFR) is altered in 50% of glioblastomas, it is currently one of the most promising therapeutic targets in this kind of tumour. Yet, inhibitors of the kinase activity of EGFR have yielded poor results in clinical trials with patients with glioblastomas. In this review we analyse the function of EGFR in glioblastomas and outline the therapeutic approaches aimed against this receptor in this kind of tumour. This sort of analysis could be a starting point for improving the design of future therapies for glioblastomas, based on inhibiting the EGFR function.

  9. Human Epidermal Growth Factor Receptor Family-Targeted Therapies in the Treatment of HER2-Overexpressing Breast Cancer

    PubMed Central

    Eroglu, Zeynep; Tagawa, Tomoko

    2014-01-01

    Breast cancer characterized by overexpression of human epidermal growth factor receptor 2 (HER2) has been associated with more aggressive disease progression and a poorer prognosis. Although an improved understanding of breast cancer pathogenesis and the role of HER2 signaling has resulted in significant survival improvements in the past 20 years, resistance to HER2-targeted therapy remains a concern. A number of strategies to prevent or overcome resistance to HER2-targeted therapy in breast cancer are being evaluated. This article provides a comprehensive review of (a) the role of HER2 signaling in breast cancer pathogenesis, (b) potential receptor and downstream therapeutic targets in breast cancer to overcome resistance to HER2-targeted therapy, and (c) clinical trials evaluating agents targeting one or more members of the HER family and/or downstream pathways for the treatment of breast cancer, with a focus on metastatic disease. PMID:24436312

  10. Prediction of Inhibitory Activity of Epidermal Growth Factor Receptor Inhibitors Using Grid Search-Projection Pursuit Regression Method

    PubMed Central

    Du, Hongying; Hu, Zhide; Bazzoli, Andrea; Zhang, Yang

    2011-01-01

    The epidermal growth factor receptor (EGFR) protein tyrosine kinase (PTK) is an important protein target for anti-tumor drug discovery. To identify potential EGFR inhibitors, we conducted a quantitative structure–activity relationship (QSAR) study on the inhibitory activity of a series of quinazoline derivatives against EGFR tyrosine kinase. Two 2D-QSAR models were developed based on the best multi-linear regression (BMLR) and grid-search assisted projection pursuit regression (GS-PPR) methods. The results demonstrate that the inhibitory activity of quinazoline derivatives is strongly correlated with their polarizability, activation energy, mass distribution, connectivity, and branching information. Although the present investigation focused on EGFR, the approach provides a general avenue in the structure-based drug development of different protein receptor inhibitors. PMID:21811593

  11. Baseline, Trend, and Normalization of Carcinoembryonic Antigen as Prognostic Factors in Epidermal Growth Factor Receptor-Mutant Nonsmall Cell Lung Cancer Patients Treated With First-Line Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitors

    PubMed Central

    Chen, Yu-Mu; Lai, Chien-Hao; Chang, Huang-Chih; Chao, Tung-Ying; Tseng, Chia-Cheng; Fang, Wen-Feng; Wang, Chin-Chou; Chung, Yu-Hsiu; Huang, Kuo-Tung; Chen, Hung-Cheng; Chang, Ya-Chun; Lin, Meng-Chih

    2015-01-01

    Abstract Among epidermal growth factor receptor (EGFR) mutation status unknown nonsmall cell lung cancer (NSCLC) patients, those with higher carcinoembryonic antigen (CEA) level are more likely to response to EGFR-tyrosine kinase inhibitors (TKIs) because they tend to have mutant epidermal growth factor receptor (EGFR). However, patients with higher CEA also have more tumor burden. With the above paradoxical evidence, it is prudent to understand the prognostic significance of baseline CEA in patients with EGFR-mutant NSCLC treated with first-line EGFR-TKIs. The clinical significance of the trend in CEA after treatment and the impact of CEA normalization during EGFR-TKI therapy are also unknown and potentially important. A total of 241 patients who received first-line EGFR-TKIs were included. As to baseline CEA, patients were divided into normal, low, and high baseline CEA by cut point determined by receiver operating characteristic curves. As to CEA responses, patients were divided into 3 groups accordingly to their amount of CEA change after taking TKIs. In group A, 1-month follow-up CEA level decreased more than 35% with nadir CEA normalization; in group B, 1-month follow-up CEA level decreased more than 35% without nadir CEA normalization; and in group C, 1-month follow-up CEA level decreased less than 35% or increased. Patients with higher baseline CEA levels had shorter progression-free survival (PFS) and overall survival (OS) (CEA > 32 vs 5–32 vs <5 ng/mL, PFS = 8.8 vs 11.3 vs 14.4 months, respectively, P < 0.001; OS = 17.8 vs 22.0 vs 27.9 months, respectively, P = 0.01). For trend and CEA normalization in groups A, B, and C, PFS was 14.3, 10.6, and 7.1 months, respectively (P < 0.001); OS was 29.7, 20.0, and 16.2 months, respectively (P < 0.001). Baseline, trend, and normalization of CEA levels are potential prognostic markers for patients with EGFR-mutant advanced NSCLC treated with first line EGFR-TKIs. PMID:26683939

  12. Epidermal growth factor receptor-dependent stimulation of amphiregulin expression in androgen-stimulated human prostate cancer cells.

    PubMed Central

    Sehgal, I; Bailey, J; Hitzemann, K; Pittelkow, M R; Maihle, N J

    1994-01-01

    Amphiregulin is a heparin-binding epidermal growth factor (EGF)-related peptide that binds to the EGF receptor (EGF-R) with high affinity. In this study, we report a role for amphiregulin in androgen-stimulated regulation of prostate cancer cell growth. Androgen is known to enhance EGF-R expression in the androgen-sensitive LNCaP human prostate carcinoma cell line, and it has been suggested that androgenic stimuli may regulate proliferation, in part, through autocrine mechanisms involving the EGF-R. In this study, we demonstrate that LNCaP cells express amphiregulin mRNA and peptide and that this expression is elevated by androgenic stimulation. We also show that ligand-dependent EGF-R stimulation induces amphiregulin expression and that androgenic effects on amphiregulin synthesis are mediated through this EGF-R pathway. Parallel studies using the estrogen-responsive breast carcinoma cell line, MCF-7, suggest that regulation of amphiregulin by estrogen may also be mediated via an EGF-R pathway. In addition, heparin treatment of LNCaP cells inhibits androgen-stimulated cell growth further suggesting that amphiregulin can mediate androgen-stimulated LNCaP proliferation. Together, these results implicate an androgen-regulated autocrine loop composed of amphiregulin and its receptor in prostate cancer cell growth and suggest that the mechanism of steroid hormone regulation of amphiregulin synthesis may occur through androgen upregulation of the EGF-R and subsequent receptor-dependent pathways. Images PMID:8049525

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

    PubMed Central

    Russo, Anthony J

    2014-01-01

    BACKGROUND One in 88 children in the US is thought to have one of the autism spectrum disorders (ASDs). ASDs are characterized by social impairments and communication problems. Growth factors and their receptors may play a role in the etiology of ASDs. Research has shown that epidermal growth factor receptor (EGFR) activation is associated with nerve cell development and repair. This study was designed to measure plasma levels of EGFR in autistic children and correlate these levels with its ligand, epidermal growth factor, other related putative biomarkers such as hepatocyte growth factor (HGF), the ligand for MET (MNNG HOS transforming gene) receptor, as well as the symptom severity of 19 different behavioral symptoms. SUBJECTS AND METHODS Plasma EGFR concentration was measured in 33 autistic children and 34 age- and gender-similar neurotypical controls, using an enzyme-linked immunosorbent assay. Plasma EGFR levels were compared to putative biomarkers known to be associated with EGFR and MET and severity levels of 19 autism-related symptoms. RESULTS We found plasma EGFR levels significantly higher in autistic children, when compared to neurotypical controls. EGFR levels correlated with HGF and high-mobility group protein B1 (HMGB1) levels, but not other tested putative biomarkers, and EGFR levels correlated significantly with severity of expressive language, conversational language, focus/attention, hyperactivity, eye contact, and sound sensitivity deficiencies. CONCLUSIONS These results suggest a relationship between increased plasma EGFR levels and designated symptom severity in autistic children. A strong correlation between plasma EGFR and HGF and HMGB1 suggests that increased EGFR levels may be associated with the HGF/Met signaling pathway, as well as inflammation. PMID:25249767

  14. Simultaneous blockade of the epidermal growth factor receptor/mammalian target of rapamycin pathway by epidermal growth factor receptor inhibitors and rapamycin results in reduced cell growth and survival in biliary tract cancer cells.

    PubMed

    Herberger, Beata; Berger, Walter; Puhalla, Harald; Schmid, Katharina; Novak, Sabine; Brandstetter, Anita; Pirker, Christine; Gruenberger, Thomas; Filipits, Martin

    2009-06-01

    The prognosis of patients with biliary tract adenocarcinomas (BTA) is still poor due to lack of effective systemic treatment options. Knowledge of the molecular mechanisms involved in the pathogenesis of this disease is of importance for the development of new treatment strategies. We determined the expression of epidermal growth factor receptor (EGFR) and activated mammalian target of rapamycin (p-mTOR) in paraffin-embedded surgical specimens of BTA (n = 89) by immunohistochemistry. Overall survival was analyzed with Cox models adjusted for clinical and pathologic factors. Combined EGFR/p-mTOR expression was significantly associated with relapse-free survival [adjusted hazard ratio for relapse, 2.20; 95% confidence interval (95% CI), 1.45-3.33; P < 0.001] and overall survival (adjusted hazard ratio for death, 2.32; 95% CI, 1.50-3.58; P < 0.001) of the patients. The effect of the EGFR inhibitors erlotinib or cetuximab and the mTOR inhibitor rapamycin on growth and survival of five BTA cell lines was tested in short-term 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assays and long-term colony formation assays. Simultaneous blockade of EGFR and mTOR in biliary tract cancer cell lines results in a synergistic inhibition of both phosphatidylinositol-3-kinase and mitogen-activated protein kinase pathways, leading to reduced cell growth and survival. These results suggest that combined targeted therapy with EGFR and mTOR inhibitors may potentially benefit patients with BTAs and should be further evaluated in clinical trials.

  15. Epidermal growth factor, oestrogen and progesterone receptor expression in primary ovarian cancer: correlation with clinical outcome and response to chemotherapy.

    PubMed Central

    Scambia, G.; Benedetti-Panici, P.; Ferrandina, G.; Distefano, M.; Salerno, G.; Romanini, M. E.; Fagotti, A.; Mancuso, S.

    1995-01-01

    The expression of epidermal growth factor receptor (EGFR), oestrogen receptor (ER) and progesterone receptor (PR) was assayed by a radioreceptor method in 117 primary ovarian cancers. EGFR was not significantly related to any of the clinicopathological parameters examined. In patients with stage II-IV disease who underwent second-look surgery after primary chemotherapy, a significant correlation between high EGFR levels and poor response to chemotherapy was demonstrated (P = 0.031). Moreover, post-operative residual tumour showed an independent role in predicting chemotherapy response (P = 0.0007) and EGFR status showed a borderline significance (P = 0.052) in the multivariate analysis. No correlation between steroid hormone receptors and clinicopathological parameters was observed. Whereas a significant relationship was shown between EGFR positivity and a shorter overall survival (OS) (P = 0.0022) and progression-free survival (PFS) (P = 0.0033), patient survival was not related to steroid hormone receptor status. Among the parameters tested only stage, ascites and EGFR status retained an independent prognostic value in the multivariate analysis. PMID:7640219

  16. The Role of Epidermal Growth Factor-Like Module Containing Mucin-Like Hormone Receptor 2 in Human Cancers

    PubMed Central

    Safaee, Michael; Ivan, Michael E.; Oh, Michael C.; Oh, Taemin; Sayegh, Eli T.; Kaur, Gurvinder; Sun, Matthew Z.; Bloch, Orin; Parsa, Andrew T.

    2014-01-01

    G-protein coupled receptors (GPCRs) are among the most diverse and ubiquitous proteins in all of biology. The epidermal growth factor-seven span transmembrane (EGF-TM7) subfamily of adhesion GPCRs is a small subset whose members are mainly expressed on the surface of leukocytes. The EGF domains on the N-terminus add significant size to these receptors and they are considered to be among the largest members of the TM7 family. Although not all of their ligands or downstream targets have been identified, there is evidence implicating the EGF-TM7 family diverse processes such as cell adhesion, migration, inflammation, and autoimmune disease. Recent studies have identified expression of EGF-TM7 family members on human neoplasms including those of the thyroid, stomach, colon, and brain. Their presence on these tissues is not surprising given the ubiquity of GPCRs, but because their functional significance and pathways are not completely understood, they are of tremendous clinical and scientific interest. Current evidence suggests that expression of certain EGF-TM7 receptors is correlated with tumor grade, confers a more invasive phenotype, and increases the likelihood of metastatic disease. In this review, we will discuss the structure, function, and regulation of these receptors. We also describe the expression of these receptors in human cancers and explore their potential mechanistic significance. PMID:25992231

  17. Epidermal growth factor receptor kinase substrate 8 promotes the metastasis of cervical cancer via the epithelial-mesenchymal transition

    PubMed Central

    Li, Qian; Bao, Wei; Fan, Qiong; Shi, Wen-Jing; Li, Zhu-Nan; Xu, Ying; Wu, Dan

    2016-01-01

    Epidermal growth factor receptor pathway substrate 8 (Eps8) has been identified as a novel substrate for epidermal growth factor receptor (EGFR) kinase and is involved in EGFR-mediated signaling pathways correlated with tumorigenesis, proliferation and metastasis in various cancer types. However, the precise role of Eps8 in cervical cancer metastasis remains to be elucidated. Immunohistochemistry revealed that Eps8 was significantly increased in cervical cancer specimens compared with squamous intraepithelial lesion and normal cervical tissues. Additionally, it was revealed that Eps8 expression not only correlated with cervical cancer progression, but also exhibited a close correlation with the epithelial-mesenchymal transition (EMT) markers, E-cadherin and vimentin. Furthermore, the present study focused predominantly on the EMT-associated role of Eps8 in the EMT, migration and invasion of cervical cancer cells. Eps8-short hairpin (sh) RNA was transfected into HeLa and SiHa cells to deplete its expression, and reverse transcription-quantitative polymerase chain reaction and western blot analyses were performed to confirm Eps8-knockdown and to investigate the influence of Eps8 on EMT markers. The present findings have revealed that Eps8 silencing led to the upregulation of the epithelial marker E-cadherin, while expression of the mesenchymal marker vimentin and the transcription factor snail was decreased at both mRNA and protein expression levels. Transwell cell migration and Matrigel invasion assays showed that downregulation of Eps8 significantly inhibited cell migration and invasion of HeLa and SiHa cells. Taken together, these results suggested that Eps8 promotes cervical cancer metastasis by orchestrating the EMT. PMID:27573546

  18. Tumor necrosis factor alpha induces the expression of transforming growth factor alpha and the epidermal growth factor receptor in human pancreatic cancer cells.

    PubMed Central

    Schmiegel, W; Roeder, C; Schmielau, J; Rodeck, U; Kalthoff, H

    1993-01-01

    Recombinant human tumor necrosis factor (TNF)-alpha increased the expression of epidermal growth factor receptor (EGFR) mRNA and protein in all of six human pancreatic carcinoma cell lines tested. In addition, TNF-alpha increased the expression of an EGFR ligand, transforming growth factor (TGF)-alpha, at the mRNA and protein level in all cell lines. Increased expression of EGFR protein was associated with elevated steady-state EGFR mRNA levels. Nuclear run-on analysis showed that increase in EGFR mRNA was due to an increased rate of transcription. Induction of EGFR mRNA expression by TNF-alpha was abrogated by cycloheximide but occurred independently of TNF-alpha-induced production of TGF-alpha protein. Protein kinase A or Gi-type guanine nucleotide-binding proteins were not involved in this process as assessed by using appropriate stimulators and inhibitors of these signal transduction pathways. By contrast, staurosporine, an inhibitor of protein kinase C, partially inhibited, and 4-bromophenacyl bromide, a phospholipase inhibitor, completely inhibited TNF-alpha-dependent EGFR mRNA expression. The phospholipase C-specific inhibitor tricyclodecan-9-yl xanthogenate did not alter TNF-alpha-dependent EGFR mRNA expression, suggesting that phospholipase A2 is involved in the modulation of EGFR expression by TNF-alpha. The simultaneous induction of a ligand/receptor system by TNF-alpha suggests that this cytokine modulates autocrine growth-regulatory pathways in pancreatic cancer cells. Images PMID:8430098

  19. The linear C-terminal regions of epidermal growth factor (EGF) and transforming growth factor-alpha bind to different epitopes on the human EGF receptor.

    PubMed Central

    Lenferink, A E; De Roos, A D; Van Vugt, M J; Van de Poll, M L; Van Zoelen, E J

    1998-01-01

    Epidermal growth factor (EGF) and transforming growth factor-alpha (TGFalpha) bind with similar affinities in a competitive fashion to the human EGF receptor, and basically induce similar mitogenic responses. In spite of the fact that EGF and TGFalpha are structurally alike, it is still not clear if the two growth factors bind the receptor in an identical manner. The observation that the 13A9 antibody blocks binding of TGFalpha, but not that of EGF, to the human EGF receptor [Winkler, O'Connor, Winget and Fendly (1989) Biochemistry 28, 6373-6378] suggests that their binding characteristics are not identical. In the present study we have made use of a set of EGF/TGFalpha chimaeric molecules to show that the 13A9 antibody blocks receptor binding of ligands with TGFalpha sequences, but not of ligands with EGF sequences, in their C-terminal linear regions. Using HaCaT human keratinocyte cells in culture, it was determined that ligands that are able to bind the EGF receptor in the presence of 13A9 are also able to induce calcium release from intracellular stores in these cells, indicating that these ligands have the ability to activate the EGF receptor in the presence of the antibody. From these data it is concluded that the flexible C-terminal linear domains of EGF and TGFalpha bind to separate sequences on the EGF receptor, such that the binding domain of TGFalpha, but not that of EGF, overlaps with the binding epitope of the 13A9 antibody. PMID:9806896

  20. Milk Epidermal Growth Factor and Gut Protection

    PubMed Central

    Dvorak, Bohuslav

    2010-01-01

    Maternal milk is a complex fluid with multifunctional roles within the developing gastrointestinal tract. Epidermal growth factor (EGF) and heparin-binding EGF-like growth factor (HB-EGF) are members of the family of EGF-related peptides. Biological actions of these growth factors are mediated via interaction with the EGF-receptor (EGF-R). In the early postnatal period, breast milk is the major source of EGF for the developing intestinal mucosa. HB-EGF is also detected in breast milk, but in concentrations 2 to 3 times lower than EGF. Under normal physiological conditions, the intestinal epithelium undergoes a continuing process of cell proliferation, differentiation and maturation. EGF plays an important role in these processes. In pathophysiologic situations, EGF contributes to epithelial protection from injury and post-injury mucosal repair. Necrotizing enterocolitis (NEC) is a devastating disease affecting prematurely born infants. The pathogenesis of NEC is not known and there is no effective treatment for this disease. In an experimental NEC model, oral administration of a physiological dose of EGF significantly reduces the incidence and severity of NEC. HB-EGF provides similar protection against NEC, but only when pharmacological doses are used. Further studies are necessary before EGF can be introduced as an efficient therapeutic approach of intestinal injury. PMID:20105663

  1. Liver-intestine cadherin induction by epidermal growth factor receptor is associated with intestinal differentiation of gastric cancer.

    PubMed

    Sakamoto, Naoya; Oue, Naohide; Sentani, Kazuhiro; Anami, Katsuhiro; Uraoka, Naohiro; Naito, Yutaka; Oo, Htoo Zarni; Hinoi, Takao; Ohdan, Hideki; Yanagihara, Kazuyoshi; Aoyagi, Kazuhiko; Sasaki, Hiroki; Yasui, Wataru

    2012-09-01

    Gastric cancer (GC) is one of the most common malignancies worldwide. The epidermal growth factor receptor (EGFR) molecule is very important in GC progression. To examine the correlation between EGFR and GC-related genes, we analyzed gene expression profiles of HT-29 cells treated with EGFR ligands and identified six genes upregulated by epidermal growth factor (EGF) and transforming growth factor (TGF)-α treatment. Among these, we focused on cadherin 17 (CDH17) encoding liver-intestine cadherin (LI-cadherin). Expression of LI-cadherin was induced by both EGF and TGF-α, as detected by quantitative RT-PCR and Western blot analysis. A luciferase assay showed that LI-cadherin promoter activity was enhanced by EGF or TGF-α in both HT-29 cells and MKN-74 GC cells. Immunohistochemical analysis of 152 GC cases showed that out of 58 LI-cadherin-positive cases, 24 (41%) cases were also positive for EGFR, whereas out of 94 LI-cadherin-negative cases, only 9 (10%) cases were positive for EGFR (P < 0.0001). Double-immunofluorescence staining revealed that EGFR and LI-cadherin were coexpressed. Significant correlation was found between LI-cadherin expression and advanced T grade and N grade. Both EGFR and LI-cadherin expression were more frequently found in GC cases with an intestinal mucin phenotype than in cases with a gastric mucin phenotype. These results indicate that, in addition to the known intestinal transcription factor caudal type homeobox 2, EGFR activation induces LI-cadherin expression and participates in intestinal differentiation of GC.

  2. Epidermal growth factor receptor-targeted lipid nanoparticles retain self-assembled nanostructures and provide high specificity.

    PubMed

    Zhai, Jiali; Scoble, Judith A; Li, Nan; Lovrecz, George; Waddington, Lynne J; Tran, Nhiem; Muir, Benjamin W; Coia, Gregory; Kirby, Nigel; Drummond, Calum J; Mulet, Xavier

    2015-02-21

    Next generation drug delivery utilising nanoparticles incorporates active targeting to specific sites. In this work, we combined targeting with the inherent advantages of self-assembled lipid nanoparticles containing internal nano-structures. Epidermal growth factor receptor (EGFR)-targeting, PEGylated lipid nanoparticles using phytantriol and 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-PEG-maleimide amphiphiles were created. The self-assembled lipid nanoparticles presented here have internal lyotropic liquid crystalline nano-structures, verified by synchrotron small angle X-ray scattering and cryo-transmission electron microscopy, that offer the potential of high drug loading and enhanced cell penetration. Anti-EGFR Fab' fragments were conjugated to the surface of nanoparticles via a maleimide-thiol reaction at a high conjugation efficiency and retained specificity following conjugation to the nanoparticles. The conjugated nanoparticles were demonstrated to have high affinity for an EGFR target in a ligand binding assay.

  3. Mechanisms of Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitor Resistance and Strategies to Overcome Resistance in Lung Adenocarcinoma

    PubMed Central

    Chang, Yoon Soo; Choi, Chang-Min

    2016-01-01

    Somatic mutations that lead to hyperactivation of epidermal growth factor receptor (EGFR) signaling are detected in approximately 50% of lung adenocarcinoma in people from the Far East population and tyrosine kinase inhibitors are now the standard first line treatment for advanced disease. They have led to a doubling of progression-free survival and an increase in overall survival by more than 2 years. However, emergence of resistant clones has become the primary cause for treatment failure, and has created a new challenge in the daily management of patients with EGFR mutations. Identification of mechanisms leading to inhibitor resistance has led to new therapeutic modalities, some of which have now been adapted for patients with unsuccessful tyrosine kinase inhibitor treatment. In this review, we describe mechanisms of tyrosine kinase inhibitor resistance and the available strategies to overcoming resistance. PMID:27790276

  4. In vivo fluorescence imaging of hepatocellular carcinoma xenograft using near-infrared labeled epidermal growth factor receptor (EGFR) peptide

    PubMed Central

    Li, Z.; Zhou, Q.; Zhou, J.; Duan, X.; Zhu, J.; Wang, T. D.

    2016-01-01

    Minimally-invasive surgery of hepatocellular carcinoma (HCC) can be limited by poor tumor visualization with white light. We demonstrate systemic administration of a Cy5.5-labeled peptide specific for epidermal growth factor receptor (EGFR) to target HCC in vivo in a mouse xenograft model. We attached a compact imaging module to the proximal end of a medical laparoscope to collect near-infrared fluorescence and reflectance images concurrently at 15 frames/sec. We measured a mean target-to-background ratio of 2.99 ± 0.22 from 13 surgically exposed subcutaneous human HCC tumors in vivo in 5 mice. This integrated imaging methodology is promising to guide laparoscopic resection of HCC.

  5. In vivo fluorescence imaging of hepatocellular carcinoma xenograft using near-infrared labeled epidermal growth factor receptor (EGFR) peptide

    PubMed Central

    Li, Z.; Zhou, Q.; Zhou, J.; Duan, X.; Zhu, J.; Wang, T. D.

    2016-01-01

    Minimally-invasive surgery of hepatocellular carcinoma (HCC) can be limited by poor tumor visualization with white light. We demonstrate systemic administration of a Cy5.5-labeled peptide specific for epidermal growth factor receptor (EGFR) to target HCC in vivo in a mouse xenograft model. We attached a compact imaging module to the proximal end of a medical laparoscope to collect near-infrared fluorescence and reflectance images concurrently at 15 frames/sec. We measured a mean target-to-background ratio of 2.99 ± 0.22 from 13 surgically exposed subcutaneous human HCC tumors in vivo in 5 mice. This integrated imaging methodology is promising to guide laparoscopic resection of HCC. PMID:27699089

  6. Production of biologically active IgG hinge-tag soluble epidermal growth factor receptors (ErbB).

    PubMed

    Otani, Takayuki; Hashizume, Toshihiro; Nagaoka, Tadahiro; Fukuda, Tomoko; Tang, Careen K; Salomon, David S; Seno, Masaharu

    2010-03-01

    The extracellular domains (ECD) of epidermal growth factor receptors, ErbB1, 2, 3 and 4, were designed as soluble dimeric forms. Each ECD was fused to a short hinge region derived from IgG, such that the stable dimer could be formed with disulfide bridges. This hinge-tagged design minimized the molecular weight to approximately 50% of the conventional Fc-fusion design without an Fc domain of IgG. The refolded dimers could be easily analyzed and characterized by SDS-PAGE. Hinge-tagged soluble ErbBs demonstrated significant affinity for betacellulin and heregulin. The IgG hinge-tag should be a simple method to design soluble dimers that would be useful for high throughput screening of ligands, antagonists or derivatives.

  7. Multiple Mechanisms are Responsible for Transactivation of the Epidermal Growth Factor Receptor in Mammary Epithelial Cells

    SciTech Connect

    Rodland, Karin D.; Bollinger, Nikki; Ippolito, Danielle L.; Opresko, Lee; Coffey, Robert J.; Zangar, Richard C.; Wiley, H. S.

    2008-11-14

    REVIEW ENTIRE DOCUMENT AT: https://pnlweb.pnl.gov/projects/bsd/ERICA%20Manuscripts%20for%20Review/KD%20Rodland%20D7E80/HMEC_transactivation_ms01_15+Figs.pdf ABSTRACT: Using a single nontransformed strain of human mammary epithelial cells, we found that the ability of multiple growth factors and cytokines to induce ERK phosphorylation was dependent on EGFR activity. These included lysophosphatidic acid (LPA), uridine triphosphate, growth hormone, vascular endothelial growth factor, insulin-like growth factor-1 (IGF-1), and tumor necrosis factoralpha. In contrast, hepatocyte growth factor could stimulate ERK phosphorylation independent of EGFR activity...

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

    PubMed Central

    Roos, W; Fabbro, D; Küng, W; Costa, S D; Eppenberger, U

    1986-01-01

    The effects of the tumor promoter phorbol 12-tetradecanoate 13-acetate (TPA) on the epidermal growth factor (EGF) receptor levels were investigated in hormone-dependent (MCF-7, T-47-D, and ZR-75-1) and hormone-independent (MDA-MB-231, HBL-100, and BT-20) human mammary carcinoma cell lines. In the absence of TPA, hormone-independent cell lines contained high concentrations of low-affinity EGF receptors (apparent Kd = 8 X 10(-10) M), whereas hormone-dependent cell lines exhibited low concentrations of high-affinity receptors (apparent Kd = 1 X 10(-10) M). TPA causes a change of the receptor from a high- to the low-affinity state in hormone-dependent cell lines (MCF-7, T-47-D, and ZR-75-1), as well as in the hormone-independent HBL-100, whereas the affinity remained unchanged in MDA-MB-231 and BT-20 cells. In addition, progesterone receptor levels are decreased after TPA treatment in the hormone-dependent cell lines MCF-7, T-47-D, and ZR-75-1, whereas the estrogen receptor levels remained unchanged. Tumor promoters such as TPA or teleocidin inhibited the proliferation of these cell lines at concentrations above 10 microM with the exception of the T-47-D cells. The most sensitive cell line towards growth inhibition by tumor promoter was the hormone-dependent MCF-7 cell line. Evaluation of different TPA analogs indicated a positive correlation between the growth-inhibitory effects and their ability to stimulate the subcellular redistribution of protein kinase C activity in MCF-7 cells. These data suggest a protein kinase C-mediated down-regulation of the progesterone receptor concentration and of the EGF receptor affinity, which is supposed to mediate the mitogenic response. Furthermore, these results support the hypothesis that the tumor-derived growth factors induced by estradiol act via the EGF receptor in hormone-dependent mammary carcinoma cells. PMID:3006036

  9. Five enzymes of the glycolytic pathway serve as substrates for purified epidermal-growth-factor-receptor kinase.

    PubMed Central

    Reiss, N; Kanety, H; Schlessinger, J

    1986-01-01

    Several enzymes of the glycolytic pathway are phosphorylated in vitro and in vivo by retroviral transforming protein kinases. These substrates include the enzymes phosphoglycerate mutase (PGM), enolase and lactate dehydrogenase (LDH). Here we show that purified EGF (epidermal growth factor)-receptor kinase phosphorylates the enzymes PGM and enolase and also the key regulatory enzymes of the glycolytic pathway, phosphofructokinase and glyceraldehyde-3-phosphate dehydrogenase (GAPDH), in an EGF-dependent manner. Stoichiometry of phosphate incorporation into GAPDH (calculated from native Mr) is the highest, reaching approximately 1. LDH and other enzymes of the glycolytic pathway are not phosphorylated by the purified EGF-receptor kinase. These enzymes are phosphorylated under native conditions, and the Km values of EGF-receptor kinase for their phosphorylation are close to the physiological concentrations of these enzymes in the cell. EGF stimulates the reaction by 2-5-fold by increasing the Vmax. without affecting the Km of this process. Phosphorylation is rapid at 22 degrees C and at higher temperatures. However, unlike the self-phosphorylation of EGF-receptor, which occurs at 4 degrees C, the glycolytic enzymes are poorly phosphorylated at this temperature. Some enzymes, in particular enolase, increase the receptor Km for ATP in the autophosphorylation process and thus may act as competitive inhibitors of EGF-receptor self-phosphorylation. On the basis of the Km values of EGF receptor for the substrate enzymes and for ATP in the phosphorylation reaction, these enzymes may also be substrates in vivo for the EGF-receptor kinase. Images Fig. 1. Fig. 2. Fig. 3. Fig. 5. Fig. 6. PMID:3030270

  10. Epidermal growth factor receptor-targeted lipid nanoparticles retain self-assembled nanostructures and provide high specificity

    NASA Astrophysics Data System (ADS)

    Zhai, Jiali; Scoble, Judith A.; Li, Nan; Lovrecz, George; Waddington, Lynne J.; Tran, Nhiem; Muir, Benjamin W.; Coia, Gregory; Kirby, Nigel; Drummond, Calum J.; Mulet, Xavier

    2015-02-01

    Next generation drug delivery utilising nanoparticles incorporates active targeting to specific sites. In this work, we combined targeting with the inherent advantages of self-assembled lipid nanoparticles containing internal nano-structures. Epidermal growth factor receptor (EGFR)-targeting, PEGylated lipid nanoparticles using phytantriol and 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-PEG-maleimide amphiphiles were created. The self-assembled lipid nanoparticles presented here have internal lyotropic liquid crystalline nano-structures, verified by synchrotron small angle X-ray scattering and cryo-transmission electron microscopy, that offer the potential of high drug loading and enhanced cell penetration. Anti-EGFR Fab' fragments were conjugated to the surface of nanoparticles via a maleimide-thiol reaction at a high conjugation efficiency and retained specificity following conjugation to the nanoparticles. The conjugated nanoparticles were demonstrated to have high affinity for an EGFR target in a ligand binding assay.Next generation drug delivery utilising nanoparticles incorporates active targeting to specific sites. In this work, we combined targeting with the inherent advantages of self-assembled lipid nanoparticles containing internal nano-structures. Epidermal growth factor receptor (EGFR)-targeting, PEGylated lipid nanoparticles using phytantriol and 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-PEG-maleimide amphiphiles were created. The self-assembled lipid nanoparticles presented here have internal lyotropic liquid crystalline nano-structures, verified by synchrotron small angle X-ray scattering and cryo-transmission electron microscopy, that offer the potential of high drug loading and enhanced cell penetration. Anti-EGFR Fab' fragments were conjugated to the surface of nanoparticles via a maleimide-thiol reaction at a high conjugation efficiency and retained specificity following conjugation to the nanoparticles. The conjugated nanoparticles

  11. Involvement of epidermal growth factor receptor-linked signaling responses in Pseudomonas fluorescens-infected alveolar epithelial cells.

    PubMed

    Choi, Hye Jin; Seo, Chan Hee; Park, Seong Hwan; Yang, Hyun; Do, Kee Hun; Kim, Juil; Kim, Hyung-Kab; Chung, Duk-Hwa; Ahn, Jung Hoon; Moon, Yuseok

    2011-05-01

    Pseudomonas fluorescens is an opportunistic indoor pathogen that can cause severe airway proinflammatory responses. Pulmonary epithelium, like other mucosal epithelial linings of the body, constitutes the first line of defense against airway microbial pathogens. Mucosal epithelial cells can be a sentinel of pathogenic bacteria via stimulation of specific cell surface receptors, including the epidermal growth factor receptor (EGFR) and Toll-like receptor (TLR). This study addressed the involvement of EGFR in airway epithelial pathogenesis by P. fluorescens. Human A549 pneumocytes showed prolonged production of proinflammatory interleukin-8 (IL-8) in response to infection with P. fluorescens, which was via the nuclear factor-kappa B (NF-κB) signaling pathway. Production of proinflammatory cytokine IL-8 was not mediated by P. fluorescens lipopolysaccharide, a representative TLR4 agonist, but was mediated through EGFR-linked signals activated by the opportunistic bacteria. Moreover, EGFR signals were involved in NF-κB signal-mediated production of proinflammatory cytokines. Along with persistent NF-κB activation, P. fluorescens enhanced the EGFR phosphorylation and subsequent activation of downstream mediators, including protein kinase B or extracellular-signal-regulated kinases 1/2. Blocking of EGFR-linked signals increased epithelial susceptibility to pathogen-induced epithelial cell death, suggesting protective roles of EGFR signals. Thus, airway epithelial exposure to P. fluorescens can trigger antiapoptotic responses via EGFR and proinflammatory responses via TLR4-independent NF-κB signaling pathway in human pneumocytes.

  12. Althaea rosea Cavanil and Plantago major L. suppress neoplastic cell transformation through the inhibition of epidermal growth factor receptor kinase.

    PubMed

    Choi, Eun-Sun; Cho, Sung-Dae; Shin, Ji-Ae; Kwon, Ki Han; Cho, Nam-Pyo; Shim, Jung-Hyun

    2012-10-01

    For thousands of years in Asia, Althaea rosea Cavanil (ARC) and Plantago major L. (PML) have been used as powerful non-toxic therapeutic agents that inhibit inflammation. However, the anticancer mechanisms and molecular targets of ARC and PML are poorly understood, particularly in epidermal growth factor (EGF)-induced neoplastic cell transformation. The aim of this study was to evaluate the chemopreventive effects and mechanisms of the methanol extracts from ARC (MARC) and PML (MPML) in EGF-induced neoplastic cell transformation of JB6 P+ mouse epidermal cells using an MTS assay, anchorage-independent cell transformation assay and western blotting. Our results showed that MARC and MPML significantly suppressed neoplastic cell transformation by inhibiting the kinase activity of the EGF receptor (EGFR). The activation of EGFR by EGF was suppressed by MARC and MPML treatment in EGFR(+/+) cells, but not in EGFR(-/-) cells. In addition, MARC and MPML inhibited EGF-induced cell proliferation in EGFR-expressing murine embryonic fibroblasts (EGFR(+/+)). These results strongly indicate that EGFR targeting by MARC and MPML may be a good strategy for chemopreventive or chemotherapeutic applications. PMID:22767187

  13. Althaea rosea Cavanil and Plantago major L. suppress neoplastic cell transformation through the inhibition of epidermal growth factor receptor kinase.

    PubMed

    Choi, Eun-Sun; Cho, Sung-Dae; Shin, Ji-Ae; Kwon, Ki Han; Cho, Nam-Pyo; Shim, Jung-Hyun

    2012-10-01

    For thousands of years in Asia, Althaea rosea Cavanil (ARC) and Plantago major L. (PML) have been used as powerful non-toxic therapeutic agents that inhibit inflammation. However, the anticancer mechanisms and molecular targets of ARC and PML are poorly understood, particularly in epidermal growth factor (EGF)-induced neoplastic cell transformation. The aim of this study was to evaluate the chemopreventive effects and mechanisms of the methanol extracts from ARC (MARC) and PML (MPML) in EGF-induced neoplastic cell transformation of JB6 P+ mouse epidermal cells using an MTS assay, anchorage-independent cell transformation assay and western blotting. Our results showed that MARC and MPML significantly suppressed neoplastic cell transformation by inhibiting the kinase activity of the EGF receptor (EGFR). The activation of EGFR by EGF was suppressed by MARC and MPML treatment in EGFR(+/+) cells, but not in EGFR(-/-) cells. In addition, MARC and MPML inhibited EGF-induced cell proliferation in EGFR-expressing murine embryonic fibroblasts (EGFR(+/+)). These results strongly indicate that EGFR targeting by MARC and MPML may be a good strategy for chemopreventive or chemotherapeutic applications.

  14. Cricket body size is altered by systemic RNAi against insulin signaling components and epidermal growth factor receptor.

    PubMed

    Dabour, Noha; Bando, Tetsuya; Nakamura, Taro; Miyawaki, Katsuyuki; Mito, Taro; Ohuchi, Hideyo; Noji, Sumihare

    2011-09-01

    A long-standing problem of developmental biology is how body size is determined. In Drosophila melanogaster, the insulin/insulin-like growth factor (I/IGF) and target of rapamycin (TOR) signaling pathways play important roles in this process. However, the detailed mechanisms by which insect body growth is regulated are not known. Therefore, we have attempted to utilize systemic nymphal RNA interference (nyRNAi) to knockdown expression of insulin signaling components including Insulin receptor (InR), Insulin receptor substrate (chico), Phosphatase and tensin homologue (Pten), Target of rapamycin (Tor), RPS6-p70-protein kinase (S6k), Forkhead box O (FoxO) and Epidermal growth factor receptor (Egfr) and observed the effects on body size in the Gryllus bimaculatus cricket. We found that crickets treated with double-stranded RNA (dsRNA) against Gryllus InR, chico, Tor, S6k and Egfr displayed smaller body sizes, while Gryllus FoxO nyRNAi-ed crickets exhibited larger than normal body sizes. Furthermore, RNAi against Gryllus chico and Tor displayed slow growth and RNAi against Gryllus chico displayed longer lifespan than control crickets. Since no significant difference in ability of food uptake was observed between the Gryllus chico(nyRNAi) nymphs and controls, we conclude that the adult cricket body size can be altered by knockdown of expressions of Gryllus InR, chico, Tor, S6k, FoxO and Egfr by systemic RNAi. Our results suggest that the cricket is a promising model to study mechanisms underlying controls of body size and life span with RNAi methods. PMID:21777227

  15. Improved tumor-to-organ ratios of a novel 67Ga-human epidermal growth factor radionuclide conjugate with preadministered antiepidermal growth factor receptor affibody molecules.

    PubMed

    Sandström, Karl; Haylock, Anna-Karin; Velikyan, Irina; Spiegelberg, Diana; Kareem, Heewa; Tolmachev, Vladimir; Lundqvist, Hans; Nestor, Marika

    2011-10-01

    The overexpression of the epidermal growth factor receptor (EGFR) in head and neck squamous cell carcinoma (HNSCC) is associated with poor prognosis. Targeted nuclear imaging of the EGFR expression could improve the diagnostics in patients with HNSCC. However, the high expression of EGFR in normal organs may conceal the tumor uptake and therefore limit the use. This study assesses the biodistribution of a novel human epidermal growth factor (hEGF) radionuclide conjugate after preinjection with anti-EGFR affibody molecules. hEGF was conjugated with p-SCN-Bn-NOTA and labeled with (67)Ga. The biodistribution of [(67)Ga]Ga-NOTA-Bn-NCS-hEGF in nude mice with EGFR-expressing xenografts was evaluated either alone or 45 minutes after preinjection with one of the anti-EGFR affibody molecules Z(EGFR:1907), (Z(EGFR:1907))(2), or (Z(EGFR:955))(2). The novel radioimmunoconjugate, [(67)Ga]Ga-NOTA-Bn-NCS-hEGF, demonstrated high stability in vitro and specific binding to hEGF in vitro and in vivo. Preinjection with anti-EGFR affibody molecules improved the tumor-to-organ ratio in the liver, salivary glands, and colon. Overall, the dimeric high-affinity affibody molecule (Z(EGFR:1907))(2) exhibited the best results. These findings show that preblocking with an anti-EGFR affibody molecule is a promising tool that could improve the outcome of radionuclide-based imaging of EGFR-expressing tumors. PMID:21834651

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

    EPA Science Inventory

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

  17. SRC-DEPENDENT PHOSPHORYLATION OF THE EPIDERMAL GROWTH FACTOR RECEPTOR ON TYROSINE 845 IS REQUIRED FOR ZINC-INDUCED RAS ACTIVATION

    EPA Science Inventory

    Src-dependent Phosphorylation of the Epidermal Growth Factor Receptor on Tyrosine 845 Is Required for Zinc-induced Ras Activation
    Weidong Wu 1 , Lee M. Graves 2 , Gordon N. Gill 3 , Sarah J. Parsons 4 , and James M. Samet 5
    1 Center for Environmental Medicine and Lung Biolo...

  18. Carboxy-terminal truncations of epidermal growth factor (EGF) receptor affect diverse EGF-induced cellular responses.

    PubMed

    Li, W; Hack, N; Margolis, B; Ullrich, A; Skorecki, K; Schlessinger, J

    1991-08-01

    The binding of epidermal growth factor (EGF) to its receptor induces tyrosine phosphorylation of phospholipase C gamma (PLC gamma), which appears to be necessary for its activation leading to phosphatidyl inositol (PI) hydrolysis. Moreover, EGF-receptor (EGF-R) activation and autophosphorylation results in binding of PLC gamma to the tyrosine phosphorylated carboxy-terminus of the receptor. To gain further insights into the mechanisms and interactions regulating these processes, we have analyzed transfected NIH-3T3 cells expressing two EGF-R carboxy-terminal deletion mutants (CD63 and CD126) with reduced capacity to stimulate PI hydrolysis, Ca2+ rises, and DNA synthesis. In fact, the CD126 mutant lacking 126 carboxy-terminal amino acids, including four tyrosine autophosphorylation sites, was unable to stimulate PI hydrolysis or Ca2+ rise in response to EGF. Surprisingly, EGF binding to the cell lines expressing CD63 or CD126 mutants was followed by similar stimulation of tyrosine phosphorylation of PLC gamma. Our results suggest that although necessary, tyrosine phosphorylation of PLC gamma may not be sufficient for stimulation and PI hydrolysis. It is clear, however, that the carboxy-terminal region of EGF-R is involved in regulation of interactions with cellular targets and therefore plays a crucial role in postreceptor signaling pathways.

  19. Alix/AIP1 antagonizes epidermal growth factor receptor downregulation by the Cbl-SETA/CIN85 complex.

    PubMed

    Schmidt, Mirko H H; Hoeller, Daniela; Yu, Jiuhong; Furnari, Frank B; Cavenee, Webster K; Dikic, Ivan; Bögler, Oliver

    2004-10-01

    The assembly of the Cbl-SETA/CIN85-endophilin complex at the C terminus of the epidermal growth factor receptor (EGFR) following ligand activation mediates its internalization and ubiquitination. We found that the SETA/CIN85-interacting protein Alix/AIP1, which also binds endophilins, modulates this complex. Alix was found to associate indirectly with EGFR, regardless of its activation state, and with DeltaEGFR, which signals at low intensity and does not bind Cbls or SETA/CIN85. In agreement with this, Alix interaction did not occur via SETA/CIN85. However, SETA/CIN85 and Alix were capable of mutually promoting their interaction with the EGFR. Increasing the level of Alix weakened the interaction between SETA/CIN85 and Cbl and reduced the tyrosine phosphorylation of c-Cbl and the level of ubiquitination of EGFR, SETA/CIN85, and Cbls. This antagonism of the Cbl-SETA/CIN85 complex by Alix was reflected in its diminution of EGFR internalization. In agreement with this, small interfering RNA-mediated knockdown of Alix promoted EGFR internalization and downregulation. It has been suggested that SETA/CIN85 promotes receptor internalization by recruiting endophilins. However, Alix was also capable of increasing the level of endophilin associated with EGFR, implying that this is not sufficient to promote receptor internalization. We propose that Alix inhibits EGFR internalization by attenuating the interaction between Cbl and SETA/CIN85 and by inhibiting Cbl-mediated ubiquitination of the EGFR.

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

    PubMed Central

    Alagappan, Dhivyaa; Ziegler, Amber N.; Chidambaram, Shravanthi; Min, Jungsoo; Wood, Teresa L.; Levison, Steven W.

    2014-01-01

    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 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. PMID:24904523

  1. Biomarkers for predicting the efficacy of anti-epidermal growth factor receptor antibody in the treatment of colorectal cancer.

    PubMed

    Okada, Yasuyuki; Miyamoto, Hiroshi; Goji, Takahiro; Takayama, Tetsuji

    2014-01-01

    Anti-epidermal growth factor receptor (EGFR) antibodies have been widely utilized as a standard treatment for metastatic colorectal cancer (CRC). Anti-EGFR antibodies bind competitively to EGFRs to inhibit receptor activation and subsequent signal transduction of the RAS/RAF/MEK pathway and PI3K/AKT pathway. By inhibiting EGFR-mediated signal transduction, anti-EGFR antibodies inhibit cell growth, invasion, metastasis and angiogenesis, and they induce apoptosis. The IgG1-type antibody cetuximab is also capable of inducing antibody-dependent cellular cytotoxicity. Several studies have shown that KRAS mutation is a useful biomarker for predicting the efficacy of anti-EGFR agents, and the major guidelines for the treatment of CRC recommend the use of anti-EGFR antibody only for the cancers with wild-type KRAS. Alterations of other genes, including BRAF, NRAS, PTEN and AKT, and EGFR expression/gene copy number have also been reported to be candidate biomarkers for predicting the efficacy of anti-EGFR agents. The predictive values of these biomarkers are still controversial and further investigations are required.

  2. (−)-Epigallocatechin gallate causes internalization of the epidermal growth factor receptor in human colon cancer cells

    PubMed Central

    Adachi, Seiji; Nagao, Tomokazu; To, Satoshi; Joe, Andrew K.; Shimizu, Masahito; Matsushima-Nishiwaki, Rie; Kozawa, Osamu; Moriwaki, Hisataka; Maxfield, Frederick R.; Weinstein, I.Bernard

    2008-01-01

    We recently found that the inhibitory effect of (−)-epigallocatechin gallate (EGCG) on epidermal growth factor (EGF) binding to the epidermal growth factor receptor (EGFR) is associated with alterations in lipid organization in the plasma membrane of colon cancer cells. Since changes in lipid organizations are thought to play a role in the trafficking of several membrane proteins, in this study we examined the effects of EGCG on cellular localization of the EGFR in SW480 cells. Treatment of the cells for 30 min with as little as 1 μg/ml of EGCG caused a decrease in cell surface-associated EGFRs and this was associated with internalization of EGFRs into endosomal vesicles. Similar effects were seen with a green fluorescent protein (GFP)–EGFR fusion protein. As expected, the EGFR protein was phosphorylated at tyrosine residues, ubiquitinated and partially degraded when the cells were treated with EGF, but treatment with EGCG caused none of these effects. The loss of EGFRs from the cell surface induced by treating the cells with EGF for 30 min persisted for at least 2 h. However, the loss of EGFRs from the cell surface induced by temporary exposure to EGCG was partially restored within 1–2 h. These studies provide the first evidence that EGCG can induce internalization of EGFRs into endosomes, which can recycle back to the cell surface. This sequestrating of inactivated EGFRs into endosomes may explain, at least in part, the ability of EGCG to inhibit activation of the EGFR and thereby exert anticancer effects. PMID:18586691

  3. Nanobiophotonics for molecular imaging of cancer: Au- and Ag-based Epidermal Growth Factor receptor (EGFR) specific nanoprobes

    NASA Astrophysics Data System (ADS)

    Lucas, Leanne J.; Hewitt, Kevin C.

    2012-03-01

    Our aim is to create and validate a novel SERS-based nanoprobe for optical imaging of the epidermal growth factor receptor (EGFR). Gold and silver nanoparticles (Au/AgNPs) of various sizes were synthesized and coupled to epidermal growth factor (EGF) via a short ligand, α-lipoic acid (206 g/mol), which binds strongly to both Au and Ag nanoparticles via its disulfide end group. We used carbodiimide chemistry to couple EGF to α-lipoic acid. These nanoprobes were tested for binding affinity using Enzyme Linked ImmunoSorbent Assay (ELISA) and, in-vitro, using EGFRoverexpressing A431 cells. The nanoprobes show excellent EGFR-specific binding. Time of Flight Mass Spectrometry demonstrate the carbodiimide based linking of the carboxylic acid end-group of α-lipoic acid to one or more of the three (terminal, or 2 lysine) amine groups on EGF. ELISA confirms that the linked EGF is active by itself, and following conjugation with gold or silver nanoparticles. Compared with bare nanoparticles, UV-Vis spectroscopy of Ag-based nanoprobes exhibit significant plasmon red-shift, while there was no discernable shift for Au-based ones. Dark field microscopy shows abundant uptake by EGFR overexpressing A431 cells, and serves to further confirm the excellent binding affinity. Nanoprobe internalization and consequent aggregation is thought to be the basis of enhanced light scattering in the dark field images, supporting the notion that these nanoprobes should provide excellent SERS signals at all nanoprobe sizes. In summary, novel EGFR-specific nanoprobes have been synthesized and validated by standard assay and in cell culture for use as SERS optical imaging probes.

  4. Coarse-grained molecular simulation of epidermal growth factor receptor protein tyrosine kinase multi-site self-phosphorylation.

    PubMed

    Koland, John G

    2014-01-01

    Upon the ligand-dependent dimerization of the epidermal growth factor receptor (EGFR), the intrinsic protein tyrosine kinase (PTK) activity of one receptor monomer is activated, and the dimeric receptor undergoes self-phosphorylation at any of eight candidate phosphorylation sites (P-sites) in either of the two C-terminal (CT) domains. While the structures of the extracellular ligand binding and intracellular PTK domains are known, that of the ∼225-amino acid CT domain is not, presumably because it is disordered. Receptor phosphorylation on CT domain P-sites is critical in signaling because of the binding of specific signaling effector molecules to individual phosphorylated P-sites. To investigate how the combination of conventional substrate recognition and the unique topological factors involved in the CT domain self-phosphorylation reaction lead to selectivity in P-site phosphorylation, we performed coarse-grained molecular simulations of the P-site/catalytic site binding reactions that precede EGFR self-phosphorylation events. Our results indicate that self-phosphorylation of the dimeric EGFR, although generally believed to occur in trans, may well occur with a similar efficiency in cis, with the P-sites of both receptor monomers being phosphorylated to a similar extent. An exception was the case of the most kinase-proximal P-site-992, the catalytic site binding of which occurred exclusively in cis via an intramolecular reaction. We discovered that the in cis interaction of P-site-992 with the catalytic site was facilitated by a cleft between the N-terminal and C-terminal lobes of the PTK domain that allows the short CT domain sequence tethering P-site-992 to the PTK core to reach the catalytic site. Our work provides several new mechanistic insights into the EGFR self-phosphorylation reaction, and demonstrates the potential of coarse-grained molecular simulation approaches for investigating the complexities of self-phosphorylation in molecules such as EGFR

  5. Epidermal growth factor and growth in vivo

    SciTech Connect

    Rhodes, J.A.

    1986-01-01

    Epidermal growth factor (EGF) causes a dose-dependent thickening of the epidermis in suckling mice. The cellular mechanisms underlying this thickening were analyzed by measuring the effect of EGF on the cell-cycle. Neonatal mice were given daily injections of either 2ug EGF/g body weight/day or an equivalent volume of saline, and on the seventh day received a single injection of /sup 3/H-thymidine. At various times the mice were perfused with fixative; 1um sections of skin were stained with a modification of Harris' hematoxylin and were autoradiographed. The sections were analyzed using three methods based on the dependence on time after injection of /sup 3/H-thymidine of: frequency of labelled mitoses, labelling index, and reciprocal grains/nucleus. It was found that EGF caused a two-fold increase in the cell production rate. The effect of exogenous EGF on the morphology of gastric mucosa and incisors of suckling mice was also studied. The gastric mucosa appeared thicker in EGF-treated animals, but the effect was not statistically significant. In contrast to its effect on epidermis and gastric mucosa, EGF caused a significant, dose-dependent decrease in the size of the incisors. Because the mouse submandibular salivary gland is the major source of EGF the effect of sialoadenectomy on female reproductive functions was examined. Ablation of the submandibular gland had no effect on: length of estrus cycle, ability of the female to produce litters, length of the gestation period, litter size, and weight of the litter at birth. There was also no effect on survival of the offspring or on age at which the eyelids separated.

  6. A Structural Model for the Membrane-Bound Form of the Juxtamembrane Domain of the Epidermal Growth Factor Receptor.

    SciTech Connect

    Choowongkomon, Kiattawee; Carlin, Cathleen R.; Sonnichsen, Frank D.

    2005-06-24

    The epidermal growth factor receptor (EGFR) is a member of the receptor tyrosine kinase family involved in the regulation of cellular proliferation and differentiation. Its juxtamembrane domain (JX), the region located between the transmembrane and kinase domains, plays important roles in receptor trafficking. Two sorting signals, a PXXP motif and a 658LL659 motif, are responsible for basolateral sorting in polarized epithelial cells, and a 679LL680 motif targets the ligand-activated receptor for lysosomal degradation. To understand the regulation of these signals, we characterized the structural properties of recombinant JX domain in aqueous solution and in dodecylphosphocholine (DPC) detergent. JX is inherently unstructured in aqueous solution, albeit a nascent helix encompasses the lysosomal sorting signal. In DPC micelles, structures derived from NMR data showed three amphipathic, helical segments. A large, internally inconsistent group of long range nuclear Overhauser effects suggest a close proximity of the helices, and the presence of significant conformational averaging. Models were determined for the average JX conformation using restraints representing the translational restriction due to micelle-surface adsorption, and the helix orientations were determined from residual dipolar couplings. Two equivalent average structural models were obtained that differ only in the relative orientation between first and second helices. In these models, the 658LL659 and 679LL680 motifs are located in the first and second helices and face the micelle surface, whereas the PXXP motif is located in a flexible helix-connecting region. The data suggest that the activity of these signals may be regulated by their membrane association and restricted accessibility in the intact receptor.

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

    PubMed

    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.

  8. Wounding Sheets of Epithelial Cells Activates the Epidermal Growth Factor Receptor through Distinct Short- and Long-Range Mechanisms

    PubMed Central

    Block, Ethan R.

    2008-01-01

    Wounding epithelia induces activation of the epidermal growth factor receptor (EGFR), which is absolutely required for induction of motility. ATP is released from cells after wounding; it binds to purinergic receptors on the cell surface, and the EGFR is subsequently activated. Exogenous ATP activates phospholipase D, and we show here that ATP activates the EGFR through the phospholipase D2 isoform. The EGFR is activated in cells far (>0.3 cm) from wounds, which is mediated by diffusion of extracellular ATP because activation at a distance from wounds is abrogated by eliminating ATP in the medium with apyrase. In sharp contrast, activation of the EGFR near wounds is not sensitive to apyrase. Time-lapse microscopy revealed that cells exhibit increased motilities near edges of wounds; this increase in motility is not sensitive to apyrase, and apyrase does not detectably inhibit healing of wounds in epithelial sheets. This novel ATP/PLD2-independent pathway activates the EGFR by a transactivation process through ligand release, and it involves signaling by a member of the Src family of kinases. We conclude that wounding activates two distinct signaling pathways that induce EGFR activation and promote healing of wounds in epithelial cells. One pathway signals at a distance from wounds through release of ATP, and another pathway acts locally and is independent on ATP signaling. PMID:18799627

  9. UNC50 Prompts G1/S Transition and Proliferation in HCC by Regulation of Epidermal Growth Factor Receptor Trafficking

    PubMed Central

    Jiang, Songmin; Cao, Lihuan; Yu, Long

    2015-01-01

    Background UNC50 has long been recognized as a Golgi apparatus protein in yeast, and is involved in nicotinic receptor trafficking in Caenorhabditis elegans, but little is known about UNC50 gene function in human biology despite it being conserved from yeast to high eukaryotes. Objectives We investigated the relation between UNC50 and human hepatocellular carcinoma (HCC) and the potential mechanisms underlying HCC development. Methods UNC50 mRNA expression patterns in 12 HCC and adjacent non-cancerous tissues determined using northern blotting were confirmed by real-time PCR in another 44 paired tissues. Microarray experiments were used to screen for global effects of UNC50 knockdown in the Hep3B cell line, and were confirmed by real-time PCR, western blotting, flow cytometry, and tetrazolium assay in both UNC50 overexpression and knockdown Hep3B cells. Results UNC50 expression levels were upregulated in HCC tissues in comparison with the adjacent non-cancerous tissues. UNC50 knockdown reduced mRNA levels of the downstream targets of the epidermal growth factor receptor (EGFR) pathway: cyclin D1 (CCND1), EGF, matrix metalloproteinase-7 (MMP7), aldose reductase-like 1 (AKR1B10), cell surface–associated mucin 1 (MUC1), and gastrin (GAST). Moreover, UNC50 influenced EGF, inducing cell cycle entry by affecting cell surface EGFR amounts. Conclusions UNC50 may plays some roles in HCC progression by affecting the EGFR pathway. PMID:25738771

  10. Phage display selection of Affibody molecules with specific binding to the extracellular domain of the epidermal growth factor receptor.

    PubMed

    Friedman, M; Nordberg, E; Höidén-Guthenberg, I; Brismar, H; Adams, G P; Nilsson, F Y; Carlsson, J; Ståhl, S

    2007-04-01

    Affibody molecules specific for the epidermal growth factor receptor (EGFR) have been selected by phage display technology from a combinatorial protein library based on the 58-residue, protein A-derived Z domain. EGFR is overexpressed in various malignancies and is frequently associated with poor patient prognosis, and the information provided by targeting this receptor could facilitate both patient diagnostics and treatment. Three selected Affibody variants were shown to selectively bind to the extracellular domain of EGFR (EGFR-ECD). Kinetic biosensor analysis revealed that the three monomeric Affibody molecules bound with similar affinity, ranging from 130 to 185 nM. Head-to-tail dimers of the Affibody molecules were compared for their binding to recombinant EGFR-ECD in biosensor analysis and in human epithelial cancer A431 cells. Although the dimeric Affibody variants were found to bind in a range of 25-50 nM affinities in biosensor analysis, they were found to be low nanomolar binders in the cellular assays. Competition assays using radiolabeled Affibody dimers confirmed specific EGFR-binding and demonstrated that the three Affibody molecules competed for the same epitope. Immunofluorescence microscopy demonstrated that the selected Affibody dimers were initially binding to EGFR at the cell surface of A431, and confocal microscopy analysis showed that the Affibody dimers could thereafter be internalized. The potential use of the described Affibody molecules as targeting agents for radionuclide based imaging applications in various carcinomas is discussed. PMID:17452435

  11. Evidence for epidermal growth factor receptor as negative-feedback control in aldosterone-induced Na+ reabsorption.

    PubMed

    Grossmann, Claudia; Freudinger, Ruth; Mildenberger, Sigrid; Krug, Alexander W; Gekle, Michael

    2004-06-01

    Aldosterone enhances Na(+) reabsorption via epithelial Na(+) channels (ENaC). Aldosterone also stimulates the protein kinase ERK1/2- and the epidermal growth factor (EGF) receptor (EGFR)-signaling pathway. Yet EGF and ERK1/2 are known inhibitors of ENaC-mediated Na(+) reabsorption. In the present study, using the well-established Madin-Darby canine kidney C7 cell line, we tested the hypothesis that EGFR represents a negative-feedback control for chronic aldosterone-induced Na(+) reabsorption [amiloride-inhibitable short-circuit current (I(sc))]. Mineralocorticoid receptor expression was confirmed by RT-PCR and Western blot analysis. Aldosterone enhanced ERK1/2 phosphorylation in an EGFR-dependent way. Furthermore, aldosterone stimulated EGFR expression. Aldosterone (10 nmol/l) induced a small transient increase in I(sc) under control conditions. Inhibition of ERK1/2 phosphorylation with U-0126 (10 micromol/l) stimulated I(sc), indicating constitutive ENaC inhibition. Aldosterone exerted a significantly larger effect in the presence of U-0126 than without U-0126. EGF (10 microg/l) inhibited I(sc), whereas inhibition of EGFR kinase by tyrphostin AG-1478 (100 nmol/l) enhanced I(sc). Aldosterone was more effective in the presence of AG-1478 than without AG-1478. In summary, we propose that the EGFR-signaling cascade can serve as a negative-feedback control to limit the effect of aldosterone-induced Na(+) reabsorption. PMID:14749256

  12. The Epidermal Growth Factor Receptor Is Involved in Angiotensin II But Not Aldosterone/Salt-Induced Cardiac Remodelling

    PubMed Central

    Griol-Charhbili, Violaine; Escoubet, Brigitte; Sadoshima, Junichi; Farman, Nicolette; Jaisser, Frederic

    2012-01-01

    Experimental and clinical studies have shown that aldosterone/mineralocorticoid receptor (MR) activation has deleterious effects in the cardiovascular system; however, the signalling pathways involved in the pathophysiological effects of aldosterone/MR in vivo are not fully understood. Several in vitro studies suggest that Epidermal Growth Factor Receptor (EGFR) plays a role in the cardiovascular effects of aldosterone. This hypothesis remains to be demonstrated in vivo. To investigate this question, we analyzed the molecular and functional consequences of aldosterone exposure in a transgenic mouse model with constitutive cardiomyocyte-specific overexpression of a mutant EGFR acting as a dominant negative protein (DN-EGFR). As previously reported, Angiotensin II-mediated cardiac remodelling was prevented in DN-EGFR mice. However, when chronic MR activation was induced by aldosterone-salt-uninephrectomy, cardiac hypertrophy was similar between control littermates and DN-EGFR. In the same way, mRNA expression of markers of cardiac remodelling such as ANF, BNF or β-Myosin Heavy Chain as well as Collagen 1a and 3a was similarly induced in DN-EGFR mice and their CT littermates. Our findings confirm the role of EGFR in AngII mediated cardiac hypertrophy, and highlight that EGFR is not involved in vivo in the damaging effects of aldosterone on cardiac function and remodelling. PMID:22291909

  13. Active macropinocytosis induction by stimulation of epidermal growth factor receptor and oncogenic Ras expression potentiates cellular uptake efficacy of exosomes

    PubMed Central

    Nakase, Ikuhiko; Kobayashi, Nahoko Bailey; Takatani-Nakase, Tomoka; Yoshida, Tetsuhiko

    2015-01-01

    Exosomes are approximately 100-nm vesicles that consist of a lipid bilayer of cellular membranes secreted in large quantities from various types of normal and disease-related cells. Endocytosis has been reported as a major pathway for the cellular uptake of exosomes; however, the detailed mechanisms of their cellular uptake are still unknown. Here, we demonstrate the active induction of macropinocytosis (accompanied by actin reorganisation, ruffling of plasma membrane, and engulfment of large volumes of extracellular fluid) by stimulation of cancer-related receptors and show that the epidermal growth factor (EGF) receptor significantly enhances the cellular uptake of exosomes. We also demonstrate that oncogenic K-Ras-expressing MIA PaCa-2 cells exhibit intensive macropinocytosis that actively transports extracellular exosomes into the cells compared with wild-type K-Ras-expressing BxPC-3 cells. Furthermore, encapsulation of the ribosome-inactivating protein saporin with EGF in exosomes using our simple electroporation method produces superior cytotoxicity via the enhanced cellular uptake of exosomes. Our findings contribute to the biological, pharmaceutical, and medical research fields in terms of understanding the macropinocytosis-mediated cellular uptake of exosomes with applications for exosomal delivery systems. PMID:26036864

  14. Active macropinocytosis induction by stimulation of epidermal growth factor receptor and oncogenic Ras expression potentiates cellular uptake efficacy of exosomes.

    PubMed

    Nakase, Ikuhiko; Kobayashi, Nahoko Bailey; Takatani-Nakase, Tomoka; Yoshida, Tetsuhiko

    2015-06-03

    Exosomes are approximately 100-nm vesicles that consist of a lipid bilayer of cellular membranes secreted in large quantities from various types of normal and disease-related cells. Endocytosis has been reported as a major pathway for the cellular uptake of exosomes; however, the detailed mechanisms of their cellular uptake are still unknown. Here, we demonstrate the active induction of macropinocytosis (accompanied by actin reorganisation, ruffling of plasma membrane, and engulfment of large volumes of extracellular fluid) by stimulation of cancer-related receptors and show that the epidermal growth factor (EGF) receptor significantly enhances the cellular uptake of exosomes. We also demonstrate that oncogenic K-Ras-expressing MIA PaCa-2 cells exhibit intensive macropinocytosis that actively transports extracellular exosomes into the cells compared with wild-type K-Ras-expressing BxPC-3 cells. Furthermore, encapsulation of the ribosome-inactivating protein saporin with EGF in exosomes using our simple electroporation method produces superior cytotoxicity via the enhanced cellular uptake of exosomes. Our findings contribute to the biological, pharmaceutical, and medical research fields in terms of understanding the macropinocytosis-mediated cellular uptake of exosomes with applications for exosomal delivery systems.

  15. Heparin-Binding Epidermal Growth Factor and Its Receptors Mediate Decidualization and Potentiate Survival of Human Endometrial Stromal Cells

    PubMed Central

    Chobotova, Katya; Karpovich, Natalia; Carver, Janet; Manek, Sanjiv; Gullick, William J.; Barlow, David H.; Mardon, Helen J.

    2006-01-01

    Heparin-binding epidermal growth factor (HB-EGF) has pleiotropic biological functions in many tissues, including those of the female reproductive tract. It facilitates embryo development and mediates implantation and is thought to have a function in endometrial receptivity and maturation. The mature HB-EGF molecule manifests its activity as either a soluble factor (sol-HB-EGF) or a transmembrane precursor (tm-HB-EGF) and can bind two receptors, EGFR and ErbB4/HER4. In this study, we identify factors that modulate expression of HB-EGF, EGFR, and ErbB4 in endometrial stromal cells in vitro. We demonstrate that levels of sol- and tm-HB-EGF, EGFR, and ErbB4 are increased by cAMP, a potent inducer of decidualization of the endometrial stroma. We also show that production of sol- and tm-HB-EGF is differentially modulated by TNFα and TGFβ. Our data suggest that HB-EGF has a function in endometrial maturation in mediating decidualization and attenuating TNFα- and TGFβ-induced apoptosis of endometrial stromal cells. PMID:15562026

  16. Antiestrogen fulvestrant enhances the antiproliferative effects of epidermal growth factor receptor inhibitors in human non-small cell lung cancer

    PubMed Central

    Garon, Edward B.; Pietras, Richard J.; Finn, Richard S.; Kamranpour, Naeimeh; Pitts, Sharon; Márquez-Garbán, Diana C.; Desai, Amrita J.; Dering, Judy; Hosmer, Wylie; von Euw, Erika M.; Dubinett, Steven M.; Slamon, Dennis J.

    2012-01-01

    Introduction Estrogen receptor (ER) signaling and its interaction with epidermal growth factor receptor (EGFR) is a potential therapeutic target in non-small cell lung cancer (NSCLC). To explore cross-communication between ER and EGFR, we have correlated ER pathway gene and protein expression profiles and examined effects of antiestrogens with or without EGFR inhibitors in preclinical models of human NSCLC. Methods We evaluated 54 NSCLC cell lines for growth inhibition with EGFR inhibitors, antiestrogen treatment or the combination. Each line was evaluated for baseline ER pathway protein expression. The majority were also evaluated for baseline ER pathway gene expression. Human NSCLC xenografts were evaluated for effects of inhibition of each pathway either individually or in combination. Results The specific antiestrogen fulvestrant has modest single agent activity in vitro, but in many lines fulvestrant adds to effects of EGFR inhibitors, including synergy in the EGFR mutant, erlotinib-resistant H1975 line. ERα, ERβ, progesterone receptor (PR)-A, PR-B and aromatase proteins are expressed in all lines to varying degrees, with trends towards lower aromatase in more sensitive cell lines. Sensitivity to fulvestrant correlates with greater baseline ERα gene expression. Tumor stability is achieved in human tumor xenografts with either fulvestrant or EGFR inhibitors, but tumors regress significantly when both pathways are inhibited. Conclusions These data provide a rationale for further investigation of the antitumor activity of combined therapy with antiestrogen and anti-EGFR agents in the clinic. Future work should also evaluate dual ER and EGFR inhibition in the setting of secondary resistance to EGFR inhibition. PMID:23399957

  17. Cellular and Tumor Radiosensitivity is Correlated to Epidermal Growth Factor Receptor Protein Expression Level in Tumors Without EGFR Amplification;Epidermal growth factor receptor; Radiotherapy; Squamous cell carcinoma; Biomarker; Local tumor control

    SciTech Connect

    Kasten-Pisula, Ulla; Saker, Jarob; Eicheler, Wolfgang; Krause, Mechthild; Yaromina, Ala; Meyer-Staeckling, Soenke; Scherkl, Benjamin; Kriegs, Malte; Brandt, Burkhard; Grenman, Reidar; Petersen, Cordula; Baumann, Michael; Dikomey, Ekkehard

    2011-07-15

    Purpose: There is conflicting evidence for whether the expression of epidermal growth factor receptor in human tumors can be used as a marker of radioresponse. Therefore, this association was studied in a systematic manner using squamous cell carcinoma (SCC) cell lines grown as cell cultures and xenografts. Methods and Materials: The study was performed with 24 tumor cell lines of different tumor types, including 10 SCC lines, which were also investigated as xenografts on nude mice. Egfr gene dose and the length of CA-repeats in intron 1 were determined by polymerase chain reaction, protein expression in vitro by Western blot and in vivo by enzyme-linked immunosorbent assay, and radiosensitivity in vitro by colony formation. Data were correlated with previously published tumor control dose 50% data after fractionated irradiation of xenografts of the 10 SCC. Results: EGFR protein expression varies considerably, with most tumor cell lines showing moderate and only few showing pronounced upregulation. EGFR upregulation could only be attributed to massive gene amplification in the latter. In the case of little or no amplification, in vitro EGFR expression correlated with both cellular and tumor radioresponse. In vivo EGFR expression did not show this correlation. Conclusions: Local tumor control after the fractionated irradiation of tumors with little or no gene amplification seems to be dependent on in vitro EGFR via its effect on cellular radiosensitivity.

  18. Epidermal growth factor receptor tyrosine kinase inhibitors as initial therapy for non-small cell lung cancer: focus on epidermal growth factor receptor mutation testing and mutation-positive patients.

    PubMed

    Roengvoraphoj, Monic; Tsongalis, Gregory J; Dragnev, Konstantin H; Rigas, James R

    2013-12-01

    Activation of the epidermal growth factor receptor (EGFR) pathway has been implicated in tumorigenesis in non-small cell lung cancer (NSCLC), the most common type of lung cancer. As a result, EGFR has become a key focus for the development of personalized therapy, with several molecular biomarkers having been investigated as potential predictors of response with EGFR tyrosine kinase inhibitors (TKIs) in NSCLC (e.g., EGFR expression, EGFR gene copy gain, and EGFR mutations). Of these, activating mutations in EGFR have thus far given the most consistent results based on the available evidence from preclinical studies and clinical trials. In an attempt to identify patients who are most likely to benefit from treatment with EGFR TKIs, EGFR mutation testing is being increasingly utilized in clinical practice. Currently in the United States, no EGFR TKI or accompanying mutational test is approved for the identification and first-line treatment of patients with advanced NSCLC. However, the first-generation EGFR TKIs, erlotinib and gefitinib, as well as investigational ErbB family TKIs and EGFR mutation testing methods are being evaluated in this setting. This review will discuss EGFR mutation testing as a biomarker of response to EGFR TKIs and the evolution of EGFR mutational analysis in NSCLC. Completed and ongoing clinical trials evaluating currently available or investigational EGFR TKIs as first-line therapy in molecularly and clinically selected patients with NSCLC, with a focus on trials in patients whose tumors have EGFR mutations, will also be reviewed.

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

    SciTech Connect

    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.

  20. IMC-C225, an anti-epidermal growth factor receptor monoclonal antibody for treatment of head and neck cancer.

    PubMed

    Herbst, Roy S; Hong, Waun Ki

    2002-10-01

    Squamous cell carcinoma of the head and neck remains a clinical challenge because of the high rate of locoregional disease recurrence. The importance of the epidermal growth factor receptor (EGFR) in the development and progression of many solid tumors, including squamous cell carcinoma of the head and neck, is well understood; increased expression is associated with enhanced tumor invasiveness, resistance to chemotherapy, and a lower patient survival rate. Several approaches have been developed to achieve EGFR blockade as an anticancer treatment strategy, including the anti-EGFR monoclonal antibody IMC-C225, which competitively binds to the extracellular receptor site and prevents binding by the natural EGFR ligands EGF and transforming growth factor-alpha. Preclinical studies to evaluate IMC-225 in human cancer cell lines in vitro and human tumor xenografts in vivo have shown its potent antitumor activity. Clinical efficacy of IMC-C225 appears to involve multiple mechanisms, including inhibition of cell cycle progression, induction of apoptosis, inhibition of angiogenesis, inhibition of metastasis, and enhancement of the response to chemotherapy and radiation therapy. Phase I studies of IMC-C225 combined with chemotherapy or radiation showed promising response rates in patients with recurrent or refractory squamous cell carcinoma of the head and neck. Phase II and III trials to examine the efficacy and safety of these combinations are currently underway. To date, IMC-C225 has been well tolerated, with skin rashes and allergic reactions being the most clinically important adverse events reported. IMC-C225 displays dose-dependent elimination characteristics and a half-life of approximately 7 days. Current recommendations for dosing include a 400 mg/m(2) loading dose, followed by weekly infusions at 250 mg/m(2).

  1. Epidermal Growth Factor Receptor Expression As Prognostic Marker in Patients With Anal Carcinoma Treated With Concurrent Chemoradiation Therapy

    SciTech Connect

    Fraunholz, Ingeborg; Falk, Stefan

    2013-08-01

    Purpose: To investigate the prognostic value of epidermal growth factor receptor (EGFR) expression in pretreatment tumor biopsy specimens of patients with anal cancer treated with concurrent 5-fluorouracil and mitomycin C-based chemoradiation therapy (CRT). Methods and Materials: Immunohistochemical staining for EGFR was performed in pretreatment biopsy specimens of 103 patients with anal carcinoma. EGFR expression was correlated with clinical and histopathologic characteristics and with clinical endpoints, including local failure-free survival (LFFS), colostomy-free survival (CFS), distant metastases-free survival (DMFS), cancer-specific survival (CSS), and overall survival (OS). Results: EGFR staining intensity was absent in 3%, weak in 23%, intermediate in 36% and intense in 38% of the patients. In univariate analysis, the level of EGFR staining was significantly correlated with CSS (absent/weak vs intermediate/intense expression: 5-year CSS, 70% vs 86%, P=.03). As a trend, this was also observed for DMFS (70% vs 86%, P=.06) and LFFS (70% vs 87%, P=.16). In multivariate analysis, N stage, tumor differentiation, and patients’ sex were independent prognostic factors for CSS, whereas EGFR expression only reached borderline significance (hazard ratio 2.75; P=.08). Conclusion: Our results suggest that elevated levels of pretreatment EGFR expression could be correlated with favorable clinical outcome in anal cancer patients treated with CRT. Further studies are warranted to elucidate how EGFR is involved in the response to CRT.

  2. Colon cancer and the epidermal growth factor receptor: Current treatment paradigms, the importance of diet, and the role of chemoprevention

    PubMed Central

    Pabla, Baldeep; Bissonnette, Marc; Konda, Vani J

    2015-01-01

    Colorectal cancer represents the third most common and the second deadliest type of cancer for both men and women in the United States claiming over 50000 lives in 2014. The 5-year survival rate for patients diagnosed with metastatic colon and rectal cancer is < 15%. Early detection and more effective treatments are urgently needed to reduce morbidity and mortality of patients afflicted with this disease. Here we will review the risk factors and current treatment paradigms for colorectal cancer, with an emphasis on the role of chemoprevention as they relate to epidermal growth factor receptor (EGFR) blockade. We will discuss how various EGFR ligands are upregulated in the presence of Western diets high in saturated and N-6 polyunsaturated fats. We will also outline the various mechanisms of EGFR inhibition that are induced by naturally occurring chemopreventative agents such as ginseng, green tea, and curcumin. Finally, we will discuss the current role of targeted chemotherapy in colon cancer and outline the limitations of our current treatment options, describing mechanisms of resistance and escape. PMID:26468449

  3. Local Epidermal Growth Factor Receptor Signaling Mediates the Systemic Pathogenic Effects of Staphylococcus aureus Toxic Shock Syndrome

    PubMed Central

    Gillman, Aaron N.; Stach, Christopher S.; Schlievert, Patrick M.; Peterson, Marnie L.

    2016-01-01

    Secreted factors of Staphylococcus aureus can activate host signaling from the epidermal growth factor receptor (EGFR). The superantigen toxic shock syndrome toxin-1 (TSST-1) contributes to mucosal cytokine production through a disintegrin and metalloproteinase (ADAM)-mediated shedding of EGFR ligands and subsequent EGFR activation. The secreted hemolysin, α-toxin, can also induce EGFR signaling and directly interacts with ADAM10, a sheddase of EGFR ligands. The current work explores the role of EGFR signaling in menstrual toxic shock syndrome (mTSS), a disease mediated by TSST-1. The data presented show that TSST-1 and α-toxin induce ADAM- and EGFR-dependent cytokine production from human vaginal epithelial cells. TSST-1 and α-toxin also induce cytokine production from an ex vivo porcine vaginal mucosa (PVM) model. EGFR signaling is responsible for the majority of IL-8 production from PVM in response to secreted toxins and live S. aureus. Finally, data are presented demonstrating that inhibition of EGFR signaling with the EGFR-specific tyrosine kinase inhibitor AG1478 significantly increases survival in a rabbit model of mTSS. These data indicate that EGFR signaling is critical for progression of an S. aureus exotoxin-mediated disease and may represent an attractive host target for therapeutics. PMID:27414801

  4. Expression and Prognostic Significance of Human Epidermal Growth Factor Receptors 1 and 3 in Gastric and Esophageal Adenocarcinoma

    PubMed Central

    Hedner, Charlotta; Borg, David; Nodin, Björn; Karnevi, Emelie; Jirström, Karin; Eberhard, Jakob

    2016-01-01

    Background Gastric and esophageal adenocarcinomas are major global cancer burdens. These cancer forms are characterized by a poor prognosis and a modest response to chemo- radio- and targeted treatment. Hence there is an obvious need for further enhanced diagnostic and treatment strategies. The aim of this study was to examine the expression and prognostic impact of human epidermal growth factor receptor 1 (HER1/EGFR) and 3 (HER3), as well as the occurrence of EGFR and KRAS mutations in gastric and esophageal adenocarcinoma. Methods Immunohistochemical expression of EGFR and HER3 was analysed in all primary tumours and a subset of lymph node metastases in a consecutive cohort of 174 patients with adenocarcinoma of the stomach, cardia and esophagus. The anti-HER3 antibody used was validated by siRNA-mediated knockdown, immunohistochemistry and quantitative real-time PCR. EGFR and KRAS mutation status was analysed by pyrosequencing tecchnology. Results and Discussion High EGFR expression was an independent risk factor for shorter overall survival (OS), whereas high HER3 expression was associated with a borderline significant trend towards a longer OS. KRAS mutations were present in only 4% of the tumours and had no prognostic impact. All tumours were EGFR wild-type. These findings contribute to the ongoing efforts to decide on the potential clinical value of different HERs and druggable mutations in gastric and esophageal adenocarcinomas, and attention is drawn to the need for more standardised investigational methods. PMID:26844548

  5. Human epidermal growth factor receptor 2 testing in gastric cancer: Recommendations of an Asia-Pacific Task Force

    PubMed Central

    Kim, Kyoung-Mee; Bilous, Michael; Chu, Kent-Man; Kim, Beom-Su; Kim, Woo-Ho; Park, Young Soo; Ryu, Min-Hee; Sheng, Weiqi; Wang, John; Chao, Yee; Ying, Jianming; Zhang, Sheng

    2014-01-01

    Human epidermal growth factor receptor 2 (HER2) testing in gastric and gastroesophageal junction cancer is an evolving area in clinical practice that has particular relevance to Asia-Pacific countries, which face a high incidence of these diseases. A growing body of evidence demonstrates that HER2-targeted therapy improves survival for patients with HER2-positive advanced disease, and drives the need for high-quality testing procedures to identify patients who will respond to treatment. However, various factors challenge day-to-day testing of gastric specimens in these countries, to a degree greater than that observed for breast specimens. Recommendations for HER2 testing of gastric cancer specimens were published as a result of the Trastuzumab for Gastric Cancer (ToGA) trial. The guidelines proposed in this manuscript build on these recommendations and emphasize local testing environments, particularly in Asia-Pacific countries. A multidisciplinary task force comprising experts from Asia-Pacific who actively work and provide education in the area was convened to assess the applicability of existing recommendations in the Asia-Pacific region. The resulting recommendations reported here highlight and clarify aspects of testing that are of particular relevance to the region, and notably emphasize multidisciplinary collaborations to optimize HER2 testing quality. PMID:25227602

  6. Expression of epidermal growth factor receptor in the preimplantation uterus and blastocyst of the western spotted skunk.

    PubMed

    Paria, B C; Das, S K; Mead, R A; Dey, S K

    1994-08-01

    The western spotted skunk is unique in that its blastocysts undergo a 180-220-day period of arrested development before implantation. We investigated the potential role of epidermal growth factor (EGF)-related growth factors in regulating uterine and embryonic development in this species by studying the status of EGF receptor (EGF-R) in these tissues during delayed implantation and resumption of embryonic development. The cell-specific distribution of EGF binding sites and the expression of EGF-R mRNA were assayed by autoradiography and Northern blot analysis, respectively. The size of EGF-R was determined by affinity cross-linking studies, and its bioactivity was examined by determining EGF-dependent subcellular protein tyrosine kinase (PTK) activity. EGF binding sites were localized in the uterine luminal and glandular epithelium, endometrial stroma, myometrium, and blood vessels during both stages of pregnancy. As examined by Northern blot hybridization, a cRNA probe specific to mouse EGF-R hybridized to poly(A)+ RNA of skunk uteri. Transcripts similar to those of mouse uterine EGF-R were identified. [125I]-EGF was cross-linked to a 170-kDa protein both in the uterus and in blastocysts collected during the delayed implantation and periimplantation periods. However, EGF-induced PTK activity was significantly elevated above background levels during the period of renewed embryonic development, but not during arrested embryonic development. The results suggest that EGF-related growth factors may play an important role in regulating embryonic development in this species and that a change in the number and/or functional status of the EGF-R may be a prerequisite for blastocyst activation and implantation in the spotted skunk.

  7. αPIX Is a Trafficking Regulator that Balances Recycling and Degradation of the Epidermal Growth Factor Receptor

    PubMed Central

    Kortüm, Fanny; Harms, Frederike Leonie; Hennighausen, Natascha; Rosenberger, Georg

    2015-01-01

    Endosomal sorting is an essential control mechanism for signaling through the epidermal growth factor receptor (EGFR). We report here that the guanine nucleotide exchange factor αPIX, which modulates the activity of Rho-GTPases, is a potent bimodal regulator of EGFR trafficking. αPIX interacts with the E3 ubiquitin ligase c-Cbl, an enzyme that attaches ubiquitin to EGFR, thereby labelling this tyrosine kinase receptor for lysosomal degradation. We show that EGF stimulation induces αPIX::c-Cbl complex formation. Simultaneously, αPIX and c-Cbl protein levels decrease, which depends on both αPIX binding to c-Cbl and c-Cbl ubiquitin ligase activity. Through interaction αPIX sequesters c-Cbl from EGFR and this results in reduced EGFR ubiquitination and decreased EGFR degradation upon EGF treatment. However, quantitatively more decisive for cellular EGFR distribution than impaired EGFR degradation is a strong stimulating effect of αPIX on EGFR recycling to the cell surface. This function depends on the GIT binding domain of αPIX but not on interaction with c-Cbl or αPIX exchange activity. In summary, our data demonstrate a previously unappreciated function of αPIX as a strong promoter of EGFR recycling. We suggest that the novel recycling regulator αPIX and the degradation factor c-Cbl closely cooperate in the regulation of EGFR trafficking: uncomplexed αPIX and c-Cbl mediate a positive and a negative feedback on EGFR signaling, respectively; αPIX::c-Cbl complex formation, however, results in mutual inhibition, which may reflect a stable condition in the homeostasis of EGF-induced signal flow. PMID:26177020

  8. αPIX Is a Trafficking Regulator that Balances Recycling and Degradation of the Epidermal Growth Factor Receptor.

    PubMed

    Kortüm, Fanny; Harms, Frederike Leonie; Hennighausen, Natascha; Rosenberger, Georg

    2015-01-01

    Endosomal sorting is an essential control mechanism for signaling through the epidermal growth factor receptor (EGFR). We report here that the guanine nucleotide exchange factor αPIX, which modulates the activity of Rho-GTPases, is a potent bimodal regulator of EGFR trafficking. αPIX interacts with the E3 ubiquitin ligase c-Cbl, an enzyme that attaches ubiquitin to EGFR, thereby labelling this tyrosine kinase receptor for lysosomal degradation. We show that EGF stimulation induces αPIX::c-Cbl complex formation. Simultaneously, αPIX and c-Cbl protein levels decrease, which depends on both αPIX binding to c-Cbl and c-Cbl ubiquitin ligase activity. Through interaction αPIX sequesters c-Cbl from EGFR and this results in reduced EGFR ubiquitination and decreased EGFR degradation upon EGF treatment. However, quantitatively more decisive for cellular EGFR distribution than impaired EGFR degradation is a strong stimulating effect of αPIX on EGFR recycling to the cell surface. This function depends on the GIT binding domain of αPIX but not on interaction with c-Cbl or αPIX exchange activity. In summary, our data demonstrate a previously unappreciated function of αPIX as a strong promoter of EGFR recycling. We suggest that the novel recycling regulator αPIX and the degradation factor c-Cbl closely cooperate in the regulation of EGFR trafficking: uncomplexed αPIX and c-Cbl mediate a positive and a negative feedback on EGFR signaling, respectively; αPIX::c-Cbl complex formation, however, results in mutual inhibition, which may reflect a stable condition in the homeostasis of EGF-induced signal flow.

  9. IL-13 and Epidermal Growth Factor Receptor Have Critical but Distinct Roles in Epithelial Cell Mucin Production

    PubMed Central

    Zhen, Guohua; Park, Sung Woo; Nguyenvu, Louis T.; Rodriguez, Madeleine W.; Barbeau, Rebecca; Paquet, Agnes C.; Erle, David J.

    2007-01-01

    Overproduction of mucus is a central feature of asthma. The cytokine, IL-13, epidermal growth factor receptor (EGFR), and transcription factor, FOXA2, have each been implicated in mucus production, but the mechanistic relationships between these molecules are not yet well understood. To address this, we established a primary normal human bronchial epithelial cell culture system with IL-13–induced mucus production and gene transcript expression changes similar to those seen in vivo in mice. IL-13 did not stimulate release of the EGFR ligand, transforming growth factor (TGF)-α. However, there was constitutive release of TGF-α from normal human bronchial epithelial cells, and inhibition of TGF-α or EGFR reduced both constitutive and IL-13–induced mucin production. Microarray analysis revealed that IL-13 and the EGFR pathway appear to have almost completely independent effects on transcript expression. IL-13 induced a relatively small set of transcripts, including several novel transcripts that might play a role in pathogenesis of allergic airway disease. In contrast, EGFR activity had extensive effects, including altered expression of many transcripts associated with cell metabolism, survival, transcription, and differentiation. One of the few common effects of IL-13 and EGFR signaling was decreased expression of FOXA2, which is known to prevent mucus production. We conclude that the IL-13 and EGFR pathways make critical but quite distinct contributions to gene regulation in airway epithelial cells, and that both pathways affect expression of the key transcription factor, FOXA2, a known regulator of mucus production. PMID:16980555

  10. Impact of palbociclib combinations on treatment of advanced estrogen receptor-positive/human epidermal growth factor 2-negative breast cancer

    PubMed Central

    Boér, Katalin

    2016-01-01

    Breast cancer is a heterogeneous disease with multiple subgroups based on clinical and molecular characteristics. For the largest subgroup of breast cancers, hormone receptor-positive/human epidermal growth factor 2 (HER2)-negative tumors, hormone treatment is the mainstay of therapy and is likely to result in significant improvement in disease outcomes. However, some of these cancers demonstrate de novo or acquired resistance to endocrine therapy. Despite intensive research to develop new strategies to enhance the efficacy of currently available treatment options for hormone receptor-positive breast cancer, progress has been slow, and there were few advances for a period of 10 years. In 2012, a new molecularly targeted therapeutic strategy, inhibition of mammalian target of rapamycin with everolimus, was introduced into clinical practice. Everolimus, in combination with a steroidal aromatase inhibitor, exemestane, resulted in an increase in progression-free survival, but not overall survival in patients with estrogen receptor (ER)+ve advanced disease who had progressed on hormone therapy. In 2015, the first cyclin-dependent kinases 4/6 (CDK4/6) inhibitor, palbociclib, received accelerated US Food and Drug Administration approval for use in combination with letrozole for the treatment of postmenopausal ER+ve/HER2−ve advanced breast cancer as initial, endocrine-based therapy. The addition of palbociclib to endocrine therapy resulted in longer progression-free survival than letrozole alone. One year later, palbociclib received a new indication, use in combination with fulvestrant, in both premenopausal and postmenopausal females with advanced breast cancer of the same subtype with disease progression following endocrine therapy. Adding palbociclib to fulvestrant resulted in a significantly increased median progression-free survival compared to fulvestrant monotherapy. These new combination regimens of palbociclib with endocrine agents represent an important

  11. NEU1 Sialidase Expressed in Human Airway Epithelia Regulates Epidermal Growth Factor Receptor (EGFR) and MUC1 Protein Signaling*

    PubMed Central

    Lillehoj, Erik P.; Hyun, Sang Won; Feng, Chiguang; Zhang, Lei; Liu, Anguo; Guang, Wei; Nguyen, Chinh; Luzina, Irina G.; Atamas, Sergei P.; Passaniti, Antonino; Twaddell, William S.; Puché, Adam C.; Wang, Lai-Xi; Cross, Alan S.; Goldblum, Simeon E.

    2012-01-01

    Epithelial cells (ECs) lining the airways provide a protective barrier between the external environment and the internal host milieu. These same airway epithelia express receptors that respond to danger signals and initiate repair programs. Because the sialylation state of a receptor can influence its function and is dictated in part by sialidase activity, we asked whether airway epithelia express catalytically active sialidase(s). Human primary small airway and A549 ECs expressed NEU1 sialidase at the mRNA and protein levels, and NEU1 accounted for >70% of EC sialidase activity. Blotting with Maackia amurensis and peanut agglutinin lectins established epidermal growth factor receptor (EGFR) and MUC1 as in vivo substrates for NEU1. NEU1 associated with EGFR and MUC1, and NEU1-EGFR association was regulated by EGF stimulation. NEU1 overexpression diminished EGF-stimulated EGFR Tyr-1068 autophosphorylation by up to 44% but enhanced MUC1-dependent Pseudomonas aeruginosa adhesion by 1.6–1.7-fold and flagellin-stimulated ERK1/2 activation by 1.7–1.9-fold. In contrast, NEU1 depletion increased EGFR activation (1.5-fold) and diminished MUC1-mediated bacterial adhesion (38–56%) and signaling (73%). These data indicate for the first time that human airway epithelia express catalytically active NEU1 sialidase that regulates EGFR- and MUC1-dependent signaling and bacterial adhesion. NEU1 catalytic activity may offer an additional level of regulation over the airway epithelial response to ligands, pathogens, and injurious stimuli. PMID:22247545

  12. Quantification of epidermal growth factor receptor expression level and binding kinetics on cell surfaces by surface plasmon resonance imaging.

    PubMed

    Zhang, Fenni; Wang, Shaopeng; Yin, Linliang; Yang, Yunze; Guan, Yan; Wang, Wei; Xu, Han; Tao, Nongjian

    2015-10-01

    Epidermal growth factor receptor (EGFR, also known as ErbB-1 or HER-1) is a membrane bound protein that has been associated with a variety of solid tumors and the control of cell survival, proliferation, and metabolism. Quantification of the EGFR expression level in cell membranes and the interaction kinetics with drugs are thus important for cancer diagnosis and treatment. Here we report mapping of the distribution and interaction kinetics of EGFR in their native environment with the surface plasmon resonance imaging (SPRi) technique. The monoclonal anti-EGFR antibody was used as a model drug in this study. The binding of the antibody to EGFR overexpressed A431 cells was monitored in real time, which was found to follow the first-order kinetics with an association rate constant (ka) and dissociation rate constant (kd) of (2.7 ± 0.6) × 10(5) M(-1) s(-1) and (1.4 ± 0.5) × 10(-4) s(-1), respectively. The dissociation constant (KD) was determined to be 0.53 ± 0.26 nM with up to seven-fold variation among different individual A431 cells. In addition, the averaged A431 cell surface EGFR density was found to be 636/μm(2) with an estimation of 5 × 10(5) EGFR per cell. Additional measurement also revealed that different EGFR positive cell lines (A431, HeLa, and A549) show receptor density dependent anti-EGFR binding kinetics. The results demonstrate that SPRi is a valuable tool for direct quantification of membrane protein expression level and ligand binding kinetics at single cell resolution. Our findings show that the local environment affects the drug-receptor interactions, and in situ measurement of membrane protein binding kinetics is important.

  13. Axl mediates acquired resistance of head and neck cancer cells to the epidermal growth factor receptor inhibitor erlotinib.

    PubMed

    Giles, Keith M; Kalinowski, Felicity C; Candy, Patrick A; Epis, Michael R; Zhang, Priscilla M; Redfern, Andrew D; Stuart, Lisa M; Goodall, Gregory J; Leedman, Peter J

    2013-11-01

    Elevated expression and activity of the epidermal growth factor receptor (EGFR) is associated with development and progression of head and neck cancer (HNC) and a poor prognosis. Clinical trials with EGFR tyrosine kinase inhibitors (e.g., erlotinib) have been disappointing in HNC. To investigate the mechanisms mediating resistance to these agents, we developed an HNC cell line (HN5-ER) with acquired erlotinib resistance. In contrast to parental HN5 HNC cells, HN5-ER cells exhibited an epithelial-mesenchymal (EMT) phenotype with increased migratory potential, reduced E-cadherin and epithelial-associated microRNAs (miRNA), and elevated vimentin expression. Phosphorylated receptor tyrosine kinase profiling identified Axl activation in HN5-ER cells. Growth and migration of HN5-ER cells were blocked with a specific Axl inhibitor, R428, and R428 resensitized HN5-ER cells to erlotinib. Microarray analysis of HN5-ER cells confirmed the EMT phenotype associated with acquired erlotinib resistance, and identified activation of gene expression associated with cell migration and inflammation pathways. Moreover, increased expression and secretion of interleukin (IL)-6 and IL-8 in HN5-ER cells suggested a role for inflammatory cytokine signaling in EMT and erlotinib resistance. Expression of the tumor suppressor miR-34a was reduced in HN5-ER cells and increasing its expression abrogated Axl expression and reversed erlotinib resistance. Finally, analysis of 302 HNC patients revealed that high tumor Axl mRNA expression was associated with poorer survival (HR = 1.66, P = 0.007). In summary, our results identify Axl as a key mediator of acquired erlotinib resistance in HNC and suggest that therapeutic inhibition of Axl by small molecule drugs or specific miRNAs might overcome anti-EGFR therapy resistance. PMID:24026012

  14. Proteasome inhibition blocks ligand-induced dynamic processing and internalization of epidermal growth factor receptor via altered receptor ubiquitination and phosphorylation.

    PubMed

    Kesarwala, Aparna H; Samrakandi, Mustapha M; Piwnica-Worms, David

    2009-02-01

    Epidermal growth factor (EGF) receptor (EGFR), a member of the EGF superfamily of receptor tyrosine kinases, is a critical regulator of cell growth and an important target for single agent and combination anticancer therapeutics. To further investigate the dynamics of ligand-induced EGFR processing and regulation noninvasively, we developed a chimeric EGFR-firefly luciferase (FLuc) fusion reporter to directly monitor processing of EGFR in real-time. In a stable HeLa cell line expressing the reporter at physiologically relevant levels, bioluminescence imaging continuously monitored reporter dynamics, correlating with the ligand-induced response of endogenous EGFR as determined by Western blot, subcellular localization of an EGFR-green fluorescent protein (GFP) fusion protein, and validated pharmacologic responses. The signaling competency of the reporter was confirmed by gene rescue experiments in EGFR-null cells. Bioluminescence analysis further showed that proteasome inhibition with bortezomib or MG132 attenuated overall ligand-induced degradation of EGFR. In cells expressing EGFR-GFP, pretreatment with proteasome inhibitors trapped essentially all of the receptor at the cell membrane both before and after ligand-induced activation with EGF. Furthermore, proteasome inhibition enhanced receptor ubiquitination in both the basal and ligand-activated states as well as delayed the processing of ligand-activated phosphorylation of the receptor, kinetically correlating with attenuated receptor degradation. These observations point to a potential mechanism for the synergistic therapeutic effects of combination EGFR- and proteasome-targeted therapies.

  15. Human epidermal growth factor receptor 2 expression in urothelial carcinoma of the renal pelvis: correlation with clinicopathologic parameters.

    PubMed

    Ehsani, Laleh; Osunkoya, Adeboye O

    2014-01-01

    The significance of human epidermal growth factor receptor 2 (HER2) overexpression in breast cancer is well established, and these patients are subsequently treated with Trastuzumab. Although HER2 expression in urothelial carcinoma of the urinary bladder has also been recently characterized, it has not been well studied in urothelial carcinoma of the renal pelvis. We investigated the relationship between HER2 overexpression in urothelial carcinoma of the renal pelvis and clinicopathologic parameters. Forty six cases were identified. HER2 overexpression was present in 34/46 (74%) cases. Mean patient age with HER2 overexpression was 68 years (range: 42-87 years). There was a male predominance with 28/34 (82%) patients. High grade urothelial carcinoma was present in 32/34 (94%) cases and 2/34 (6%) cases had low grade urothelial carcinoma. Pathologic staging was as follows; 9/34 (26%) cases were pTa, 10/34 (29%) cases were pT1, 2/34 (6%) cases were pT2, 12/34 (35%) cases were pT3, and 1/34 (3%) cases was pT4. An inverted growth pattern was present in 23/46 (50%) cases. HER2 overexpression was present in 15/23 (65%) cases of urothelial carcinoma with an inverted growth pattern. Our study showed that HER2 overexpression is more common in male patients with high grade urothelial carcinoma, especially those with an inverted growth pattern. It is highly conceivable that patients with urothelial carcinoma of the renal pelvis may be further stratified based on HER2 overexpression, and may also be potential candidates for Trastuzumab therapy in the neoadjuvant or adjuvant setting. PMID:24966967

  16. MicroRNA-27a functions as a tumor suppressor in renal cell carcinoma by targeting epidermal growth factor receptor

    PubMed Central

    LI, YUEYAN; LI, JIE; SUN, XIAOLEI; CHEN, JIACUN; SUN, XIAOQING; ZHENG, JUNNIAN; CHEN, RENFU

    2016-01-01

    Numerous studies have suggested that microRNAs (miRNAs) are vital in the development of various types of human cancers, including renal cell carcinoma (RCC), and the regulation of tumor progression and invasion. However, the effect of miRNA-27a (miR-27a) on the tumorigenesis of RCC is unclear. The aim of the present study was to investigate the function of miR-27a and identify its possible target genes in RCC cells. In the present study, cell proliferation, migration and invasion and the percentage of apoptotic cells were detected by methylthiazol tetrazolium assays, Annexin V analysis, wound-healing assays and Transwell invasion assays. Western blot analysis was performed to validate the protein expression level and assess whether the epidermal growth factor receptor (EGFR) was a target gene of miR-27a. A tumor xenograft animal model was used to detect the role of miR-27a on RCC cell growth in vivo. The present study demonstrated that miR-27a significantly suppressed human RCC 786-O cell proliferation and induced cell apoptosis. Restoration of miR-27 also resulted in 786-O cell migration and invasion inhibition. Furthermore, upregulated miR-27a attenuated RCC tumor growth in the tumor xenograft animal model. The present results suggested that miR-27a functions as a tumor suppressor in RCC. The western blot analysis assay revealed that EGFR was a novel target of miR-27a. The growth suppression of RCC cells was attributed partly to the downregulation of the cell cycle by ERFR inhibition. The present findings may aid in the understanding of the molecular mechanism of miR-27a in the tumorigenesis of RCC, and may provide novel diagnostic and therapeutic options for RCC. PMID:27313769

  17. Enhanced Human Epidermal Growth Factor Receptor 2 Degradation in Breast Cancer Cells by Lysosome-Targeting Gold Nanoconstructs.

    PubMed

    Lee, Hyojin; Dam, Duncan Hieu M; Ha, Ji Won; Yue, Jun; Odom, Teri W

    2015-10-27

    This paper describes how gold nanoparticle nanoconstructs can enhance anticancer effects of lysosomal targeting aptamers in breast cancer cells. Nanoconstructs consisting of anti-HER2 aptamer (human epidermal growth factor receptor 2, HApt) densely grafted on gold nanostars (AuNS) first targeted HER2 and then were internalized via HER2-mediated endocytosis. As incubation time increased, the nanoconstruct complexes were found in vesicular structures, starting from early endosomes to lysosomes as visualized by confocal fluorescence and differential interference contrast microscopy. Within the target organelle, lysosomes, HER2 was degraded by enzymes at low pH, which resulted in apoptosis. At specific time points related to the doubling time of the cancer cells, we found that accumulation of HER2-HApt-AuNS complexes in lysosomes, lysosomal activity, and lysosomal degradation of HER2 were positively correlated. Increased HER2 degradation by HApt-AuNS triggered cell death and cell cycle arrest in the G0/G1 phase inhibition of cell proliferation. This work shows how a perceived disadvantage of nanoparticle-based therapeutics-the inability of nanoconstructs to escape from vesicles and thus induce a biological response-can be overcome by both targeting lysosomes and exploiting lysosomal degradation of the biomarkers.

  18. The inhibition of epidermal growth factor receptor signaling by hexagonal selenium nanoparticles modified by SiRNA.

    PubMed

    Kamrani Moghaddam, L; Ramezani Paschepari, S; Zaimy, M A; Abdalaian, A; Jebali, A

    2016-09-01

    The aim of this study was to investigate the effect of hexagonal selenium nanoparticles modified by SiRNA (HSNM-SiRNA) to inhibit epidermal growth factor receptor (EGFR) signaling in Human non-small-cell lung cancer (NSCLC). After synthesis, HSNM-SiRNA and HSNs were separately exposed to NSCLC cell lines (A549, H1299, H520, and H1975), and incubated for 6 h at 37 °C. Next, the expression of NFKB, MYC, STAT, ELK1, and GAPDH was evaluated by western blot and real-time PCR. The percentage of apoptotic cells and cell cycle progression were measured when exposed to HSNM-SiRNA and HSNs. Both western blot and real-time PCR results showed that HSNM-SiRNA could down-regulate the expression of all EGFR signaling genes. The percentage of apoptotic cells was significantly increased in all cell lines when exposed to HSNM-SiRNA (P>0.05). HSNM-SiRNA in A549 and H1299 cells significantly increased the proportion of cells in G1/G0 phase and significantly decreased the proportion of cells in S phase. PMID:27608774

  19. Novel diphenylamine 2,4'-dicarboxamide based azoles as potential epidermal growth factor receptor inhibitors: synthesis and biological activity.

    PubMed

    Abou-Seri, Sahar Mahmoud; Farag, Nahla Ahmed; Hassan, Ghaneya Sayed

    2011-01-01

    Several hybrid molecules of diphenylamine-2,4'-dicarboxamide with various azolidinones and related heterocyclic rings have been synthesized and explored as epidermal growth factor receptor (EGFR) kinase inhibitors. Most of them displayed promising in vitro tyrosine kinase inhibition as well as potent cellular antiproliferative activity in the EGFR over-expressing breast cancer cell line (MCF-7). Compounds 12b and 13b that exhibited the highest inhibition in the kinase assay (89, 81% inhibition at 10 μM, respectively), showed potent antiproliferative effect against MCF-7 tumor cell line (IC(50) 1.04, 0.91 μM respectively). Molecular docking studies revealed that these compounds can bind to ATP binding site of the EGFR kinase domain and were involved in H-bonding with Met 793, in analogy to the known EGFR tyrosine kinase inhibitors. Moreover, compounds 15a-c possessed profound antitumor activity (IC(50) 0.59-0.73 μM) and significant EGFR-TK inhibition, making them of particular interest. In summary, the newly synthesized compounds provide promising new lead for the future design and development of anticancer agents of potential EGFR-TK inhibitory activity.

  20. Evaluation of a novel saliva‐based epidermal growth factor receptor mutation detection for lung cancer: A pilot study

    PubMed Central

    Pu, Dan; Liang, Hao; Wei, Fang; Akin, David; Feng, Ziding; Yan, QingXiang; Li, Yin; Zhen, Yan; Xu, Lin; Dong, Gaochao; Wan, Huajing; Dong, Jingsi; Qiu, Xiaoming; Qin, Changlong; Zhu, Daxing; Wang, Xi; Sun, Tong; Zhang, Wenbiao; Li, Canjun; Tang, Xiaojun; Qiao, Youlin

    2016-01-01

    Background This article describes a pilot study evaluating a novel liquid biopsy system for non‐small cell lung cancer (NSCLC) patients. The electric field‐induced release and measurement (EFIRM) method utilizes an electrochemical biosensor for detecting oncogenic mutations in biofluids. Methods Saliva and plasma of 17 patients were collected from three cancer centers prior to and after surgical resection. The EFIRM method was then applied to the collected samples to assay for exon 19 deletion and p.L858 mutations. EFIRM results were compared with cobas results of exon 19 deletion and p.L858 mutation detection in cancer tissues. Results The EFIRM method was found to detect exon 19 deletion with an area under the curve (AUC) of 1.0 in both saliva and plasma samples in lung cancer patients. For L858R mutation detection, the AUC of saliva was 1.0, while the AUC of plasma was 0.98. Strong correlations were also found between presurgery and post‐surgery samples for both saliva (0.86 for exon 19 and 0.98 for L858R) and plasma (0.73 for exon 19 and 0.94 for L858R). Conclusion Our study demonstrates the feasibility of utilizing EFIRM to rapidly, non‐invasively, and conveniently detect epidermal growth factor receptor mutations in the saliva of patients with NSCLC, with results corresponding perfectly with the results of cobas tissue genotyping. PMID:27385985

  1. Icotinib combined whole brain radiotherapy for patients with brain metastasis from lung adenocarcinoma harboring epidermal growth factor receptor mutation

    PubMed Central

    Li, Jin-Rui; Zhang, Ye

    2016-01-01

    Background The brain is a metastatic organ that is most prone to lung adenocarcinoma (LAC). However, the prognosis of patients with brain metastasis remains very poor. In this study, we evaluated the efficacy of icotinib plus whole brain radiation therapy (WBRT) for treating patients with brain metastasis from epidermal growth factor receptor (EGFR)-mutated LAC. Methods All patients received standard WBRT administered to the whole brain in 30 Gy in 10 daily fractions. Each patient was also instructed to take 125 mg icotinib thrice per day beginning from the first day of the WBRT. After completing the WBRT, maintenance icotinib was administered until the disease progressed or intolerable adverse effects were observed. Cranial progression-free survival (CPFS) and overall survival (OS) times were the primary endpoints. Results A total of 43 patients were enrolled in this study. Two patients (4.7%) presented a complete response (CR), whereas 20 patients (46.5%) presented a partial response (PR). The median CPFS and OS times were 11.0 and 15.0 months, respectively. The one-year CPFS rate was 40.0% for the patients harboring EGFR exon 19 deletion and 16.7% for the patients with EGFR exon 21 L858R (P=0.027). Conclusions The concurrent administration of icotinib and WBRT exhibited favorable effects on the patients with brain metastasis. EGFR exon 19 deletion was predictive of a long CPFS following icotinib plus WBRT. PMID:27499937

  2. MIIP accelerates epidermal growth factor receptor protein turnover and attenuates proliferation in non-small cell lung cancer

    PubMed Central

    Wen, Jing; Fu, Jianhua; Ling, Yihong; Zhang, Wei

    2016-01-01

    The migration and invasion inhibitory protein (MIIP) has been discovered recently to have inhibitory functions in cell proliferation and migration. Overexpression of MIIP reduced the intracellular steady-state level of epidermal growth factor receptor (EGFR) protein in lung cancer cells with no effect on EGFR mRNA expression compared to that in the control cells. This MIIP-promoted EGFR protein degradation was reversed by proteasome and lysosome inhibitors, suggesting the involvement of both proteasomal and lysosomal pathways in this degradation. This finding was further validated by pulse-chase experiments using 35S-methionine metabolic labeling. We found that MIIP accelerates EGFR protein turnover via proteasomal degradation in the endoplasmic reticulum and then via the lysosomal pathway after its entry into endocytic trafficking. MIIP-stimulated downregulation of EGFR inhibits downstream activation of Ras and blocks the MEK signal transduction pathway, resulting in inhibition of cell proliferation. The negative correlation between MIIP and EGFR protein expression was validated in lung adenocarcinoma samples. Furthermore, the higher MIIP protein expression predicts a better overall survival of Stage IA-IIIA lung adenocarcinoma patients who underwent radical surgery. These findings reveal a new mechanism by which MIIP inhibits cell proliferation. PMID:26824318

  3. Human epidermal growth factor receptor 2 overexpression in breast cancer of patients with anti-Yo--associated paraneoplastic cerebellar degeneration.

    PubMed

    Rojas-Marcos, Iñigo; Picard, Geraldine; Chinchón, David; Gelpi, Ellen; Psimaras, Dimitri; Giometto, Bruno; Delattre, J Y; Honnorat, J; Graus, F

    2012-04-01

    Isolated case reports suggest that breast tumors from patients with paraneoplastic cerebellar degeneration (PCD) and Yo antibodies overexpress human epidermal growth factor receptor 2 (HER2). HER2 overexpression is present in 15%-25% of breast cancers and is associated with poor prognosis. We retrospectively analyzed the status of HER2 in breast tumors of 27 patients with anti-Yo-associated PCD to evaluate whether HER2 overexpression in this group of patients is higher than expected. In addition, we analyzed HER2 status of 19 breast tumors from patients with paraneoplastic neurological syndromes and Ri antibodies to see whether HER2 was specifically related to anti-Yo-associated PCD. We also assessed cdr2 expression (the onconeural antigen recognized by Yo antibodies) in 21 HER2-positive breast tumors from patients without paraneoplastic neurological syndromes. HER2 was overexpressed in 26 patients (96.3%) with anti-Yo-associated PCD but only in 2 patients (10.5%) with paraneoplastic neurological syndromes associated with Ri antibodies (P< .0001). Only 5 (23.8%) of the 21 HER2-positive breast tumors showed cdr2 immunoreactivity. This study shows a very high frequency of HER2 overexpression in breast cancers in patients with anti-Yo-associated PCD but not in those from patients with Ri antibodies. Although the expression of cdr2 onconeural antigen is not high in HER2-positive breast cancers, HER2 overexpression seems to be an important requirement to develop an anti-Yo-associated PCD.

  4. Epidermal growth factor receptor tyrosine kinase inhibitors with conventional chemotherapy for the treatment of non-small cell lung cancer

    PubMed Central

    Gao, Yuan; Song, PingPing; Li, Hui; Guo, HongBo; Jia, Hui; Zhang, BaiJiang

    2016-01-01

    We report a Chinese male patient with advanced stage lung squamous cell carcinoma who developed brain metastases after responding to treatment comprising six cycles of conventional chemotherapy with docetaxel and cisplatin. The patient was then treated with oral erlotinib (150 mg/day) and whole-brain radiation therapy followed by four cycles of docetaxel and carboplatin chemotherapy. The patient then received gefitinib (250 mg/day) as a maintenance therapy until the end of the follow-up period. In this patient, progression-free survival, defined as the interval from the initiation of first-line chemotherapy to the cessation of erlotinib due to progressive disease or death from any cause, was 3 months. Overall survival, defined as the interval from the initiation of first-line chemotherapy to death from any cause, was 75 months. Erlotinib was well tolerated in combination with whole-brain radiation therapy and a favorable objective response rate was observed. Furthermore, targeted drug treatment warrants consideration in patients with a negative epidermal growth factor receptor mutation status and male patients with a history of smoking. PMID:26719713

  5. Epidermal growth factor receptor mutation in adenocarcinoma lung in a North Indian population: Prevalence and relation with different clinical variables

    PubMed Central

    Kasana, Basharat Ahmad; Dar, Waseem Raja; Aziz, Sheikh Aijaz; Lone, Abdul Rashid; Sofi, Najeeb Ullah; Dar, Imtiyaz Ahmad; Latief, Muzamil; Arshad, Faheem; Hussain, Moomin; Hussain, Mir

    2016-01-01

    Introduction: Lung cancer is one of the most common causes of cancer deaths worldwide. Adenocarcinoma is taking over squamous cell lung cancer as the predominant histological subtype. Several cytotoxic drugs are available for the treatment of lung cancer, but side effects limit their use. Recently, targeted therapies for cancers have come into clinical practice. Aims and Objectives: To determine the prevalence of epidermal growth factor receptor (EGFR) mutation in adenocarcinoma lung in a North Indian population and its relation with different clinical variables. Materials and Methods: A total of 57 patients who met inclusion criteria were recruited into the study. Relevant history, clinical examination and investigations were done. EGFR mutation was done in all patients. Results: A total of twenty patients tested positive for EGFR mutation. EGFR was more frequently detected in female patients (53.8%), while as only 19.4% of the male patients expressed EGFR mutation, which was statistically very significant (P = 0.007). EGFR mutation was more frequently detected in nonsmokers (52%) as compared to smokers (21.9%) which also was statistically significant (P value of 0.018). EGFR mutation was more common in Stage III and IV adenocarcinomas (48%) as compared to Stage I and II (21.4%) which was statistically significant (P value 0.034). Conclusion: EGFR mutation should be routinely done in all patients of adenocarcinoma lung particularly non-smoker females with Stage III and IV disease. PMID:27688613

  6. Sensitivity and kinase activity of epidermal growth factor receptor (EGFR) exon 19 and others to EGFR-tyrosine kinase inhibitors.

    PubMed

    Furuyama, Kazuto; Harada, Taishi; Iwama, Eiji; Shiraishi, Yoshimasa; Okamura, Kyoko; Ijichi, Kayo; Fujii, Akiko; Ota, Keiichi; Wang, Shuo; Li, Heyan; Takayama, Koichi; Giaccone, Giuseppe; Nakanishi, Yoichi

    2013-05-01

    The presence of epidermal growth factor receptor (EGFR) somatic mutations in non-small-cell lung cancer patients is associated with response to treatment with EGFR-tyrosine kinase inhibitors, such as gefitinib and erlotinib. More than 100 mutations in the kinase domain of EGFR have been identified. In particular there are many variations of deletion mutations in exon 19. In this study, using yellow fluorescent protein-tagged fragments of the EGFR intracellular domain, we examined the differences in sensitivity to gefitinib, erlotinib and afatinib between several exon 19 mutants and other common EGFR mutations. We also used serum of patients undergoing treatment with EGFR-tyrosine kinase inhibitors in this system. In addition, we examined the relative kinase activity of these mutants by measuring relative fluorescent intensity after immunofluorescence staining. We found that both sensitivity to EGFR-tyrosine kinase inhibitors and relative kinase activity differed among several EGFR mutations found in the same region of the kinase domain. This study underscores the importance of reporting the clinical outcome of treatment in relation to different EGFR mutations.

  7. The next generation of epidermal growth factor receptor tyrosine kinase inhibitors in the treatment of lung cancer.

    PubMed

    Steuer, Conor E; Khuri, Fadlo R; Ramalingam, Suresh S

    2015-04-15

    The discovery of "driver" genomic alterations in patients with non-small cell lung cancer (NSCLC) has dramatically changed the field of thoracic oncology in recent years. The best understood of these molecular drivers are those involving the epidermal growth factor receptor (EGFR), which when aberrantly activated are integral to the development of a subset of NSCLC tumors. First-generation and second-generation tyrosine kinase inhibitors (TKIs) specific to the activated EGFR have shown significant efficacy and have brought about the era of targeted therapy for NSCLC. The most common resistance mechanism is a threonine-to-methionine substitution (T790M) in exon 20 of the EGFR gene. Although the previous standard of care in patients with EGFR-mutated NSCLC that progressed on initial TKI therapy was chemotherapy, third-generation EGFR TKIs have now been developed and have yielded promising results for this population of patients with NSCLC. This article reviews the emerging data regarding third-generation agents in the treatment of patients with advanced NSCLC.

  8. UBE4B Protein Couples Ubiquitination and Sorting Machineries to Enable Epidermal Growth Factor Receptor (EGFR) Degradation*

    PubMed Central

    Sirisaengtaksin, Natalie; Gireud, Monica; Yan, Qing; Kubota, Yoshihisa; Meza, Denisse; Waymire, Jack C.; Zage, Peter E.; Bean, Andrew J.

    2014-01-01

    The signaling of plasma membrane proteins is tuned by internalization and sorting in the endocytic pathway prior to recycling or degradation in lysosomes. Ubiquitin modification allows recognition and association of cargo with endosomally associated protein complexes, enabling sorting of proteins to be degraded from those to be recycled. The mechanism that provides coordination between the cellular machineries that mediate ubiquitination and endosomal sorting is unknown. We report that the ubiquitin ligase UBE4B is recruited to endosomes in response to epidermal growth factor receptor (EGFR) activation by binding to Hrs, a key component of endosomal sorting complex required for transport (ESCRT) 0. We identify the EGFR as a substrate for UBE4B, establish UBE4B as a regulator of EGFR degradation, and describe a mechanism by which UBE4B regulates endosomal sorting, affecting cellular levels of the EGFR and its downstream signaling. We propose a model in which the coordinated action of UBE4B, ESCRT-0, and the deubiquitinating enzyme USP8 enable the endosomal sorting and lysosomal degradation of the EGFR. PMID:24344129

  9. Targeting of epidermal growth factor receptor (EGFR)-expressing tumor cells with sterically stabilized affibody liposomes (SAL).

    PubMed

    Beuttler, Julia; Rothdiener, Miriam; Müller, Dafne; Frejd, Fredrik Y; Kontermann, Roland E

    2009-06-01

    Affibody molecules are small and stable antigen-binding molecules derived from the B domain of protein A. We applied a bivalent, high-affinity epidermal growth factor receptor (EGFR)-specific affibody molecule for the generation of targeted PEGylated liposomes. These sterically stabilized affibody liposomes (SAL) were produced by chemical coupling of the cysteine-modified affibody molecule to maleimide-PEG(2000)-DSPE and subsequent insertion into PEGylated liposomes. These SAL showed strong and selective binding to EGFR-expressing tumor cell lines. Binding was dependent on the amount of inserted affibody molecule-lipid conjugates and could be blocked by soluble EGF. Approximately 30% of binding activity was still retained after 6 days of incubation in human plasma at 37 degrees C. Binding of SAL to cells led to efficient internalization of the liposomes. Using mitoxantrone-loaded liposomes, we observed for SAL, compared to untargeted liposomes, an enhanced cytotoxicity toward EGFR-expressing cells. In summary, we show that SAL can be easily prepared from affibody molecules and thus may be suitable for the development of carrier systems for targeted delivery of drugs. PMID:19435362

  10. Patterns of epidermal growth factor receptor mutation in non-small-cell lung cancers in the Gulf region

    PubMed Central

    JAZIEH, ABDUL RAHMAN; JAAFAR, HASAN; JALOUDI, MOHAMMED; MUSTAFA, RASHA SALEH; RASUL, KAKIL; ZEKRI, JAMAL; BAMEFLEH, HANAA; GASMELSEED, AHMED

    2015-01-01

    The aim of the present study was to determine the prevalence of epidermal growth factor receptor mutations (EGFRmut) in the Gulf region (GR) and its correlation with demographic and clinical characteristics. A multisite retrospective study was conducted, including institutions from Saudi Arabia, the United Arab Emirates and Qatar. All consecutive patients with non-small-cell lung cancer tested for EGFRmut were eligible. Data collected included demographic information, disease characteristics and EGFR test results. Data on 230 patients were obtained. The median age of the patients was 61 years (range, 26–87 years); 169 patients (69.83%) were male and 204 (88.7%) were Arab. The histological subtype was adenocarcinoma in 191 (83.4%) and squamous cell carcinoma in 21 cases (9.17%). Overall, EGFRmut were detected in 66 patients (28.7%), with a prevalence of 32.46% in adenocarcinoma. No squamous cell carcinomas were found to harbor EGFRmut. The univariate and multivariate analyses revealed that female gender, non-smoking status and adenocarcinoma subtype were significant predictors for EGFRmut. There was no difference between Arabs and non-Arabs. In conclusion, to the best of our knowledge, this is the first multisite study to report the prevalence of EGFRmut in the GR population, which was found to be higher compared with that in Western, but lower compared with that in Far Eastern populations. Studies evaluating the efficacy of targeted therapy in this population are underway. PMID:26807249

  11. Human Epidermal Growth Factor Receptor 2 (HER2/neu) in Salivary Gland Carcinomas: A Review of Literature

    PubMed Central

    Alotaibi, Abdullah Mislat; Alqarni, Mohammed Ali; Alnobi, Abdelrahman

    2015-01-01

    The aim of our study is to assess the relation of human epidermal growth factor receptor 2 or HER2/neu with the development of salivary gland carcinomas and use of Herceptin in the treatment of these cancers. A literature search was conducted using MEDLINE accessed via the National Library of Medicine PubMed interface searching for articles from 1994 up to 2014 relating to the existence of HER-2 protein and gene in salivary gland carcinomas and HER2/neu targeted therapy, written in English language. Almost all the studies in literature reported a frequent over expression and amplification of HER2/nue in salivary duct carcinomas (SDC) compared to other salivary gland cancers. Herceptin given as a monotherapy was not effective. The data on Herceptin combined chemotherapy are potentially promising but inadequate to evaluate drug activity, as patients also received a variety of cytotoxic agents. Therefore, Herceptin contribution to tumour response outcomes could not be precisely determined and the total number of cases is not sufficient. It is recommended that further work involves a large series of HER2/neu positive salivary gland cancers (randomized control trial) treated with chemotherapy with and without Herceptin. This might need multi-institutional cooperation. PMID:25859537

  12. Aptamer-conjugated gold nanorod for photothermal ablation of epidermal growth factor receptor-overexpressed epithelial cancer

    NASA Astrophysics Data System (ADS)

    Choi, Jihye; Park, Yeonji; Choi, Eun Bi; Kim, Hyun-Ouk; Kim, Dong Joo; Hong, Yoochan; Ryu, Sung-Ho; Lee, Jung Hwan; Suh, Jin-Suck; Yang, Jaemoon; Huh, Yong-Min; Haam, Seungjoo

    2014-05-01

    Biomarker-specific photothermal nanoparticles that can efficiently sense markers that are overexpressed in distinguished adenocarcinomas have attracted much interest in an aspect of efficacy increase of cancer treatment. We demonstrated a promising prospect of a smart photothermal therapy agent employing anti-epidermal growth factor receptor aptamer (AptEGFR)-conjugated polyethylene glycol (PEG) layted gold nanorods (AptEGFR-PGNRs). The cetyltrimethylammonium bromide bilayer on GNRs was replaced with heterobifunctional PEG (COOH-PEG-SH) not only to serve as a biocompatible stabilizer and but also to conjugate Apt. Subsequently, to direct photothermal therapy agent toward epithelial cancer cells, the carboxylated PEGylated GNRs (PGNRs) were further functionalized with Apt using carbodiimide chemistry. Then, to assess the potential as biomarker-specific photothermal therapy agent of synthesized Apt-PGNRs, the optical properties, biocompatibility, colloidal stability, binding affinity, and epicellial cancer cell killing efficacy in vitro/in vivo under near-infrared laser irradiation were investigated. As a result, Apt-PGNRs exhibit excellent tumor targeting ability and feasibility of effective photothermal ablation cancer therapy.

  13. Association of epidermal growth factor receptor gene amplification with loss of chromosome 10 in human glioblastoma multiforme.

    PubMed

    von Deimling, A; Louis, D N; von Ammon, K; Petersen, I; Hoell, T; Chung, R Y; Martuza, R L; Schoenfeld, D A; Yaşargil, M G; Wiestler, O D

    1992-08-01

    Although the loss of tumor suppressor genes and the activation of oncogenes have been established as two of the fundamental mechanisms of tumorigenesis in human cancer, little is known about the possible interactions between these two mechanisms. Loss of genetic material on chromosome 10 and amplification of the epidermal growth factor receptor (EGFR) gene are the most frequently reported genetic abnormalities in glioblastoma multiforme. In order to examine a possible correlation between these two genetic aberrations, the authors studied 106 gliomas (58 glioblastomas, 14 anaplastic astrocytomas, five astrocytomas, nine pilocytic astrocytomas, seven mixed gliomas, six oligodendrogliomas, two ependymomas, one subependymoma, one subependymal giant-cell astrocytoma, and three gangliogliomas) with Southern blot analysis for loss of heterozygosity on both arms of chromosome 10 and for amplification of the EGFR gene. Both the loss of genetic material on chromosome 10 and EGFR gene amplification were restricted to the glioblastomas. Of the 58 glioblastoma patients, 72% showed loss of chromosome 10 and 38% showed EGFR gene amplification. The remaining 28% had neither loss of chromosome 10 nor EGFR gene amplification. Without exception, the glioblastomas that exhibited EGFR gene amplification had also lost genetic material on chromosome 10 (p less than 0.001). This invariable association suggests a relationship between the two genetic events. Moreover, the presence of 15 cases of glioblastoma with loss of chromosome 10 but without EGFR gene amplification may further imply that the loss of a tumor suppressor gene (or genes) on chromosome 10 precedes EGFR gene amplification in glioblastoma tumorigenesis.

  14. Miliary never-smoking adenocarcinoma of the lung: strong association with epidermal growth factor receptor exon 19 deletion.

    PubMed

    Laack, Eckart; Simon, Ronald; Regier, Marc; Andritzky, Birte; Tennstedt, Pierre; Habermann, Christian; Verth, Christoph Zur; Thöm, Ina; Grob, Tobias; Sauter, Guido; Bokemeyer, Carsten

    2011-01-01

    Miliary pattern of pulmonary metastases is a rarity in patients with lung cancer. We report five cases of patients with a never-smoking adenocarcinoma of the lung with such a pattern of metastases. In the tumor cells of all five patients, epidermal growth factor receptor (EGFR) mutation gene sequencing identified a deletion in exon 19 of the EGFR gene, and all five patients had a dramatic response to EGFR tyrosine kinase inhibitors. No echinoderm microtubule-associated protein-like 4 (EML4)-anaplastic lymphoma kinase (ALK) translocation was detected. We believe that the miliary never-soking adenocarcinoma of the lung is a distinct clinically relevant subgroup of the never-smoking non-small cell lung cancer. Physician should recognize this subgroup of patients with lung cancer when facing a picture of miliary pulmonary metastases in chest x-ray or computed tomography scan in patients with a history of never smoking and consider upfront therapy with EGFR tyrosine kinase inhibitors. PMID:21178715

  15. Epidermal growth factor receptor plays a role in the regulation of liver and plasma lipid levels in adult male mice.

    PubMed

    Scheving, Lawrence A; Zhang, Xiuqi; Garcia, Oscar A; Wang, Rebecca F; Stevenson, Mary C; Threadgill, David W; Russell, William E

    2014-03-01

    Dsk5 mice have a gain of function in the epidermal growth factor receptor (EGFR), caused by a point mutation in the kinase domain. We analyzed the effect of this mutation on liver size, histology, and composition. We found that the livers of 12-wk-old male Dsk5 heterozygotes (+/Dsk5) were 62% heavier compared with those of wild-type controls (+/+). The livers of the +/Dsk5 mice compared with +/+ mice had larger hepatocytes with prominent, polyploid nuclei and showed modestly increased cell proliferation indices in both hepatocytes and nonparenchymal cells. An analysis of total protein, DNA, and RNA (expressed relative to liver weight) revealed no differences between the mutant and wild-type mice. However, the livers of the +/Dsk5 mice had more cholesterol but less phospholipid and fatty acid. Circulating cholesterol levels were twice as high in adult male +/Dsk5 mice but not in postweaned young male or female mice. The elevated total plasma cholesterol resulted mainly from an increase in low-density lipoprotein (LDL). The +/Dsk5 adult mouse liver expressed markedly reduced protein levels of LDL receptor, no change in proprotein convertase subtilisin/kexin type 9, and a markedly increased fatty acid synthase and 3-hydroxy-3-methyl-glutaryl-CoA reductase. Increased expression of transcription factors associated with enhanced cholesterol synthesis was also observed. Together, these findings suggest that the EGFR may play a regulatory role in hepatocyte proliferation and lipid metabolism in adult male mice, explaining why elevated levels of EGF or EGF-like peptides have been positively correlated to increased cholesterol levels in human studies.

  16. Epidermal growth factor receptor plays a role in the regulation of liver and plasma lipid levels in adult male mice.

    PubMed

    Scheving, Lawrence A; Zhang, Xiuqi; Garcia, Oscar A; Wang, Rebecca F; Stevenson, Mary C; Threadgill, David W; Russell, William E

    2014-03-01

    Dsk5 mice have a gain of function in the epidermal growth factor receptor (EGFR), caused by a point mutation in the kinase domain. We analyzed the effect of this mutation on liver size, histology, and composition. We found that the livers of 12-wk-old male Dsk5 heterozygotes (+/Dsk5) were 62% heavier compared with those of wild-type controls (+/+). The livers of the +/Dsk5 mice compared with +/+ mice had larger hepatocytes with prominent, polyploid nuclei and showed modestly increased cell proliferation indices in both hepatocytes and nonparenchymal cells. An analysis of total protein, DNA, and RNA (expressed relative to liver weight) revealed no differences between the mutant and wild-type mice. However, the livers of the +/Dsk5 mice had more cholesterol but less phospholipid and fatty acid. Circulating cholesterol levels were twice as high in adult male +/Dsk5 mice but not in postweaned young male or female mice. The elevated total plasma cholesterol resulted mainly from an increase in low-density lipoprotein (LDL). The +/Dsk5 adult mouse liver expressed markedly reduced protein levels of LDL receptor, no change in proprotein convertase subtilisin/kexin type 9, and a markedly increased fatty acid synthase and 3-hydroxy-3-methyl-glutaryl-CoA reductase. Increased expression of transcription factors associated with enhanced cholesterol synthesis was also observed. Together, these findings suggest that the EGFR may play a regulatory role in hepatocyte proliferation and lipid metabolism in adult male mice, explaining why elevated levels of EGF or EGF-like peptides have been positively correlated to increased cholesterol levels in human studies. PMID:24407590

  17. Epidermal growth factor receptor plays a role in the regulation of liver and plasma lipid levels in adult male mice

    PubMed Central

    Zhang, Xiuqi; Garcia, Oscar A.; Wang, Rebecca F.; Stevenson, Mary C.; Threadgill, David W.; Russell, William E.

    2014-01-01

    Dsk5 mice have a gain of function in the epidermal growth factor receptor (EGFR), caused by a point mutation in the kinase domain. We analyzed the effect of this mutation on liver size, histology, and composition. We found that the livers of 12-wk-old male Dsk5 heterozygotes (+/Dsk5) were 62% heavier compared with those of wild-type controls (+/+). The livers of the +/Dsk5 mice compared with +/+ mice had larger hepatocytes with prominent, polyploid nuclei and showed modestly increased cell proliferation indices in both hepatocytes and nonparenchymal cells. An analysis of total protein, DNA, and RNA (expressed relative to liver weight) revealed no differences between the mutant and wild-type mice. However, the livers of the +/Dsk5 mice had more cholesterol but less phospholipid and fatty acid. Circulating cholesterol levels were twice as high in adult male +/Dsk5 mice but not in postweaned young male or female mice. The elevated total plasma cholesterol resulted mainly from an increase in low-density lipoprotein (LDL). The +/Dsk5 adult mouse liver expressed markedly reduced protein levels of LDL receptor, no change in proprotein convertase subtilisin/kexin type 9, and a markedly increased fatty acid synthase and 3-hydroxy-3-methyl-glutaryl-CoA reductase. Increased expression of transcription factors associated with enhanced cholesterol synthesis was also observed. Together, these findings suggest that the EGFR may play a regulatory role in hepatocyte proliferation and lipid metabolism in adult male mice, explaining why elevated levels of EGF or EGF-like peptides have been positively correlated to increased cholesterol levels in human studies. PMID:24407590

  18. Differential regulation of epidermal growth factor receptor by hydrogen peroxide and flagellin in cultured lung alveolar epithelial cells.

    PubMed

    Nishi, Hiroyuki; Maeda, Noriko; Izumi, Shunsuke; Higa-Nakamine, Sayomi; Toku, Seikichi; Kakinohana, Manabu; Sugahara, Kazuhiro; Yamamoto, Hideyuki

    2015-02-01

    In previous studies, we found that stimulation of Toll-like receptor 5 (TLR5) by flagellin induced the activation of mitogen-activated protein kinase (MAPK)-activated protein kinase-2 (MAPKAPK-2) through activation of the p38 MAPK pathway in cultured alveolar epithelial A549 cells. Our studies strongly suggested that MAPKAPK-2 phosphorylated epidermal growth factor receptor (EGFR) at Ser1047. It has been reported that phosphorylation of Ser1047 after treatment with tumor necrosis factor α (TNFα) induced the internalization of EGFR. In the present study, we first found that treatment of A549 cells with hydrogen peroxide induced the activation of MAPKAPK-2 and phosphorylation of EGFR at Ser1047 within 30 min. This was different from flagellin treatment because hydrogen peroxide treatment induced the phosphorylation of EGFR at Tyr1173 as well as Ser1047, indicating the activation of EGFR. We also found that KN93, an inhibitor of CaM kinase II, inhibited the hydrogen peroxide-induced phosphorylation of EGFR at Ser1047 through inhibition of the activation of the p38 MAPK pathway. Furthermore, we examined the internalization of EGFR by three different methods. Flow cytometry with an antibody against the extracellular domain of EGFR and biotinylation of cell surface proteins revealed that flagellin, but not hydrogen peroxide, decreased the amount of cell-surface EGFR. In addition, activation of extracellular signal-regulated kinase by EGF treatment was reduced by flagellin pre-treatment. These results strongly suggested that hydrogen peroxide activated the p38 MAPK pathway via activation of CaM kinase II and that flagellin and hydrogen peroxide regulate the functions of EGFR by different mechanisms.

  19. Targeting Cancer Stem Cell Plasticity Through Modulation of Epidermal Growth Factor and Insulin-Like Growth Factor Receptor Signaling in Head and Neck Squamous Cell Cancer

    PubMed Central

    Leong, Hui Sun; Chong, Fui Teen; Sew, Pui Hoon; Lau, Dawn P.; Wong, Bernice H.; Teh, Bin-Tean

    2014-01-01

    Emerging data suggest that cancer stem cells (CSCs) exist in equilibrium with differentiated cells and that stochastic transitions between these states can account for tumor heterogeneity and drug resistance. The aim of this study was to establish an in vitro system that recapitulates stem cell plasticity in head and neck squamous cell cancers (HNSCCs) and identify the factors that play a role in the maintenance and repopulation of CSCs. Tumor spheres were established using patient-derived cell lines via anchorage-independent cell culture techniques. These tumor spheres were found to have higher aldehyde dehydrogenase (ALD) cell fractions and increased expression of Kruppel-like factor 4, SRY (sex determining region Y)-box 2, and Nanog and were resistant to γ-radiation, 5-fluorouracil, cisplatin, and etoposide treatment compared with monolayer culture cells. Monolayer cultures were subject to single cell cloning to generate clones with high and low ALD fractions. ALDHigh clones showed higher expression of stem cell and epithelial-mesenchymal transition markers compared with ALDLow clones. ALD fractions, representing stem cell fractions, fluctuated with serial passaging, equilibrating at a level specific to each cell line, and could be augmented by the addition of epidermal growth factor (EGF) and/or insulin. ALDHigh clones showed increased EGF receptor (EGFR) and insulin-like growth factor-1 receptor (IGF-1R) phosphorylation, with increased activation of downstream pathways compared with ALDLow clones. Importantly, blocking these pathways using specific inhibitors against EGFR and IGF-1R reduced stem cell fractions drastically. Taken together, these results show that HNSCC CSCs exhibit plasticity, with the maintenance of the stem cell fraction dependent on the EGFR and IGF-1R pathways and potentially amenable to targeted therapeutics. PMID:25024430

  20. Immunohistochemical localization of transforming growth factor-alpha and epidermal growth factor-receptor in the mesonephros and metanephros of the chicken.

    PubMed

    Díaz-Ruiz, C; Pérez-Tomás, R; Culleré, X; Domingo, J

    1993-01-01

    Transforming growth factor-alpha (TGF-alpha) is a polypeptide related to epidermal growth factor (EGF). Both bind to EGF-receptor (EGF-R) to carry out their function in a variety of tissues and cell lines. Several studies have shown their presence in mammalian kidney, however, nothing has to date been stated concerning their existence in avian kidney. Expression of TGF-alpha and EGF-R is reported here for the first time during the development of the chicken kidney. Using immunohistochemical techniques, we identified a TGF-alpha (but not EGF) in mesonephric distal tubule cells from day 8 to day 20 of embryonic development and in metanephric distal tubule cells from day 14 of embryonic development to the adult. The histochemical characteristics of these cells and their histological localization suggest that they may be the "principal cells" of the distal tubules. Similarly, EGF-R was found in mesonephric proximal tubule cells from day 7 to day 18 of embryonic development and in metanephric proximal tubule cells from day 13 of embryonic development up to adult stages. The coexistence of both TGF-alpha and EGF-R from the onset of development of mesonephros and metanephros supports their possible role in mechanisms of proliferation and differentiation of the cells of these organs.

  1. MEK-ERK Pathway Modulation Ameliorates Pulmonary Fibrosis Associated with Epidermal Growth Factor Receptor Activation

    PubMed Central

    Madala, Satish K.; Schmidt, Stephanie; Davidson, Cynthia; Ikegami, Machiko; Wert, Susan

    2012-01-01

    Pulmonary fibrosis remains a significant public health burden with no proven therapies. The mitogen-activated protein kinase (MAPK)/MAPK kinase (MEK)/extracellular signal–regulated kinase (ERK) signaling cascade is a major pathway controlling cellular processes associated with fibrogenesis, including growth, proliferation, and survival. Activation of the MAPK/ERK pathway is detected in the lungs of human fibrosis samples; however, the effect of modulating the pathway in vivo is unknown. Overexpression of transforming growth factor (TGF)-α in the lung epithelium of transgenic mice causes a progressive pulmonary fibrosis associated with increased MEK/ERK activation localized primarily in mesenchymal cells. To determine the role of the MEK pathway in the induction of TGF-α–induced lung fibrosis, TGF-α was overexpressed for 4 weeks while mice were simultaneously treated with the specific MEK inhibitor, ARRY-142886 (ARRY). Treatment with ARRY prevented increases in lung cell proliferation and total lung collagen, attenuated production of extracellular matrix genes, and protected mice from changes in lung function. ARRY administered as a rescue treatment after fibrosis was already established inhibited fibrosis progression, as assessed by lung histology, changes in body weights, extracellular matrix gene expression, and lung mechanics. These findings demonstrate that MEK inhibition prevents progression of established fibrosis in the TGF-α model, and provides proof of concept of targeting the MEK pathway in fibrotic lung disease. PMID:22021337

  2. Treatment challenges for community oncologists treating postmenopausal women with endocrine-resistant, hormone receptor-positive, human epidermal growth factor receptor 2-negative advanced breast cancer

    PubMed Central

    Gradishar, William J

    2016-01-01

    Community-based oncologists are faced with challenges and opportunities when delivering quality patient care, including high patient volumes and diminished resources; however, there may be the potential to deliver increased patient education and subsequently improve outcomes. This review discusses the treatment of postmenopausal women with endocrine-resistant, hormone receptor-positive, human epidermal growth factor receptor 2- negative advanced breast cancer in order to illustrate considerations in the provision of pertinent quality education in the treatment of these patients and the management of therapy-related adverse events. An overview of endocrine-resistant breast cancer and subsequent treatment challenges is also provided. Approved treatment options for endocrine-resistant breast cancer include hormonal therapies and mammalian target of rapamycin inhibitors. Compounds under clinical investigation are also discussed. PMID:27468248

  3. Treatment challenges for community oncologists treating postmenopausal women with endocrine-resistant, hormone receptor-positive, human epidermal growth factor receptor 2-negative advanced breast cancer.

    PubMed

    Gradishar, William J

    2016-01-01

    Community-based oncologists are faced with challenges and opportunities when delivering quality patient care, including high patient volumes and diminished resources; however, there may be the potential to deliver increased patient education and subsequently improve outcomes. This review discusses the treatment of postmenopausal women with endocrine-resistant, hormone receptor-positive, human epidermal growth factor receptor 2- negative advanced breast cancer in order to illustrate considerations in the provision of pertinent quality education in the treatment of these patients and the management of therapy-related adverse events. An overview of endocrine-resistant breast cancer and subsequent treatment challenges is also provided. Approved treatment options for endocrine-resistant breast cancer include hormonal therapies and mammalian target of rapamycin inhibitors. Compounds under clinical investigation are also discussed. PMID:27468248

  4. Association between serum ligands and the skin toxicity of anti-epidermal growth factor receptor antibody in metastatic colorectal cancer.

    PubMed

    Takahashi, Naoki; Yamada, Yasuhide; Furuta, Koh; Nagashima, Kengo; Kubo, Akiko; Sasaki, Yusuke; Shoji, Hirokazu; Honma, Yoshitaka; Iwasa, Satoru; Okita, Natsuko; Takashima, Atsuo; Kato, Ken; Hamaguchi, Tetsuya; Shimada, Yasuhiro

    2015-05-01

    Skin toxicity is a known clinical signature used to predict the prognosis of anti-epidermal growth factor receptor (EGFR) antibody treatment in metastatic colorectal cancer (mCRC). There are no biological markers to predict skin toxicity before anti-EGFR antibody treatment in mCRC patients. Between August 2008 and August 2011, pretreatment serum samples were obtained from KRAS wild-type (WT) patients who received anti-EGFR antibody treatment. Serum levels of ligands were measured by ELISA. A total of 103 KRAS WT patients were enrolled in the study. Progression-free survival and overall survival of patients with a high grade (grade 2-3) of skin toxicity were significantly longer than those with a low grade (grade 0-1) of skin toxicity (median progression-free survival, 6.4 months vs 2.4 months, P < 0.001; median overall survival, 14.6 months vs 7.1 months, P = 0.006). There were significant differences in distribution of serum levels of epiregulin (EREG), amphiregulin (AREG), and hepatocyte growth factor (HGF) between groups of low/high grade of skin toxicity (P < 0.048, P < 0.012, P < 0.012, respectively). In addition, serum levels of HGF, EREG, and AREG were inversely proportional to grades of skin toxicity as determined by the Cochran-Armitage test (P = 0.019, P = 0.047, P = 0.021, respectively). Our study indicated that serum levels such as HGF, EREG, and AREG may be significant markers to predict the grade of skin toxicity and the prognosis of anti-EGFR antibody treatment, which contribute to improvement of the management of skin toxicity and survival time in mCRC patients.

  5. A Role for the Epidermal Growth Factor Receptor Signaling in Development of Intestinal Serrated Polyps in Mice and Humans

    PubMed Central

    Bongers, Gerold; Muniz, Luciana R.; Pacer, Michelle E.; Iuga, Alina C.; Thirunarayanan, Nanthakumar; Slinger, Erik; Smit, Martine J.; Reddy, E. Premkumar; Mayer, Lloyd; Furtado, Glaucia C.; Harpaz, Noam; Lira, Sergio A.

    2012-01-01

    Background & Aims Epithelial cancers can be initiated by activating mutations in components of the mitogen-activated protein kinase (MAPK) signaling pathway such as BRAF, KRAS, or epidermal growth factor receptor (EGFR). Human intestinal serrated polyps are a heterogeneous group of benign lesions, but some progress to colorectal cancer. Tumors that arise from these polyps frequently contain activating mutations in BRAF or KRAS, but little is known about the role of EGFR activation in their development. Methods Polyp samples were obtained from adults during screening colonoscopies at Mount Sinai Hospital in New York. We measured levels of EGFR protein and phosphorylation in human serrated polyps by immunohistochemical and immunoblot analyses. We generated transgenic mice that express the ligand for EGFR, HB-EGF, in the intestine. Results EGFR and the extracellular-regulated kinases (ERK)1/2 were phosphorylated in serrated areas of human hyperplastic polyps (HPPs), sessile serrated adenomas, and traditional serrated adenomas. EGFR and ERK1/2 were phosphorylated in the absence of KRAS or BRAF activating mutations in a subset of HPP. Transgenic expression of the EGFR ligand HB-EGF in the intestines of mice promoted development of small cecal serrated polyps. Mice that expressed a combination of HB-EGF and US28 (a constitutively active, G-protein–coupled receptor that increases processing of HB-EGF from the membrane) rapidly developed large cecal serrated polyps. These polyps were similar to HPPs and had increased phosphorylation of EGFR and ERK1/2 within the serrated epithelium. Administration of pharmacologic inhibitors of EGFR or MAP kinase to these transgenic mice significantly reduced polyp development. Conclusions Activation of EGFR signaling in the intestine of mice promotes development of serrated polyps. EGFR signaling is also activated in human HPPs, sessile serrated adenomas, and traditional serrated adenomas. PMID:22643351

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

    NASA Astrophysics Data System (ADS)

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

    2014-11-01

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

  7. PET imaging of epidermal growth factor receptor expression in tumours using 89Zr-labelled ZEGFR:2377 affibody molecules

    PubMed Central

    GAROUSI, JAVAD; ANDERSSON, KEN G.; MITRAN, BOGDAN; PICHL, MARIE-LOUISE; STÅHL, STEFAN; ORLOVA, ANNA; LÖFBLOM, JOHN; TOLMACHEV, VLADIMIR

    2016-01-01

    Epidermal growth factor receptor (EGFR) is a transmembrane tyrosine kinase receptor, which is overexpressed in many types of cancer. The use of EGFR-targeting monoclonal antibodies and tyrosine-kinase inhibitors improves significantly survival of patients with colorectal, non-small cell lung cancer and head and neck squamous cell carcinoma. Detection of EGFR overexpression provides important prognostic and predictive information influencing management of the patients. The use of radionuclide molecular imaging would enable non-invasive repeatable determination of EGFR expression in disseminated cancer. Moreover, positron emission tomography (PET) would provide superior sensitivity and quantitation accuracy in EGFR expression imaging. Affibody molecules are a new type of imaging probes, providing high contrast in molecular imaging. In the present study, an EGFR-binding affibody molecule (ZEGFR:2377) was site-specifically conjugated with a deferoxamine (DFO) chelator and labelled under mild conditions (room temperature and neutral pH) with a positron-emitting radionuclide 89Zr. The 89Zr-DFO-ZEGFR:2377 tracer demonstrated specific high affinity (160±60 pM) binding to EGFR-expressing A431 epidermoid carcinoma cell line. In mice bearing A431 xenografts, 89Zr-DFO-ZEGFR:2377 demonstrated specific uptake in tumours and EGFR-expressing tissues. The tracer provided tumour uptake of 2.6±0.5% ID/g and tumour-to-blood ratio of 3.7±0.6 at 24 h after injection. 89Zr-DFO-ZEGFR:2377 provides higher tumour-to-organ ratios than anti-EGFR antibody 89Zr-DFO-cetuximab at 48 h after injection. EGFR-expressing tumours were clearly visualized by microPET using 89Zr-DFO-ZEGFR:2377 at both 3 and 24 h after injection. In conclusion, 89Zr-DFO-ZEGFR:2377 is a potential probe for PET imaging of EGFR-expression in vivo. PMID:26847636

  8. Directed evolution to low nanomolar affinity of a tumor-targeting epidermal growth factor receptor-binding affibody molecule.

    PubMed

    Friedman, Mikaela; Orlova, Anna; Johansson, Eva; Eriksson, Tove L J; Höidén-Guthenberg, Ingmarie; Tolmachev, Vladimir; Nilsson, Fredrik Y; Ståhl, Stefan

    2008-03-01

    The epidermal growth factor receptor 1 (EGFR) is overexpressed in various malignancies and is associated with a poor patient prognosis. A small, receptor-specific, high-affinity imaging agent would be a useful tool in diagnosing malignant tumors and in deciding upon treatment and assessing the response to treatment. We describe here the affinity maturation procedure for the generation of Affibody molecules binding with high affinity and specificity to EGFR. A library for affinity maturation was constructed by rerandomization of selected positions after the alignment of first-generation binding variants. New binders were selected with phage display technology, using a single oligonucleotide in a single-library effort, and the best second-generation binders had an approximately 30-fold improvement in affinity (K(d)=5-10 nM) for the soluble extracellular domain of EGFR in biospecific interaction analysis using Biacore. The dissociation equilibrium constant, K(d), was also determined for the Affibody with highest affinity using EGFR-expressing A431 cells in flow cytometric analysis (K(d)=2.8 nM). A retained high specificity for EGFR was verified by a dot blot assay showing staining only of EGFR proteins among a panel of serum proteins and other EGFR family member proteins (HER2, HER3, and HER4). The EGFR-binding Affibody molecules were radiolabeled with indium-111, showing specific binding to EGFR-expressing A431 cells and successful targeting of the A431 tumor xenografts with 4-6% injected activity per gram accumulated in the tumor 4 h postinjection. PMID:18207161

  9. PET imaging of epidermal growth factor receptor expression in tumours using 89Zr-labelled ZEGFR:2377 affibody molecules.

    PubMed

    Garousi, Javad; Andersson, Ken G; Mitran, Bogdan; Pichl, Marie-Louise; Ståhl, Stefan; Orlova, Anna; Löfblom, John; Tolmachev, Vladimir

    2016-04-01

    Epidermal growth factor receptor (EGFR) is a transmembrane tyrosine kinase receptor, which is overexpressed in many types of cancer. The use of EGFR-targeting monoclonal antibodies and tyrosine-kinase inhibitors improves significantly survival of patients with colorectal, non-small cell lung cancer and head and neck squamous cell carcinoma. Detection of EGFR overexpression provides important prognostic and predictive information influencing management of the patients. The use of radionuclide molecular imaging would enable non-invasive repeatable determination of EGFR expression in disseminated cancer. Moreover, positron emission tomography (PET) would provide superior sensitivity and quantitation accuracy in EGFR expression imaging. Affibody molecules are a new type of imaging probes, providing high contrast in molecular imaging. In the present study, an EGFR-binding affibody molecule (ZEGFR:2377) was site-specifically conjugated with a deferoxamine (DFO) chelator and labelled under mild conditions (room temperature and neutral pH) with a positron-emitting radionuclide (89)Zr. The (89)Zr-DFO-ZEGFR:2377 tracer demonstrated specific high affinity (160 ± 60 pM) binding to EGFR-expressing A431 epidermoid carcinoma cell line. In mice bearing A431 xenografts, (89)Zr-DFO-ZEGFR:2377 demonstrated specific uptake in tumours and EGFR-expressing tissues. The tracer provided tumour uptake of 2.6 ± 0.5% ID/g and tumour-to-blood ratio of 3.7 ± 0.6 at 24 h after injection. (89)Zr-DFO-ZEGFR:2377 provides higher tumour-to-organ ratios than anti-EGFR antibody (89)Zr-DFO-cetuximab at 48 h after injection. EGFR‑expressing tumours were clearly visualized by microPET using (89)Zr-DFO-ZEGFR:2377 at both 3 and 24 h after injection. In conclusion, 8(9)Zr-DFO-ZEGFR:2377 is a potential probe for PET imaging of EGFR-expression in vivo. PMID:26847636

  10. IMC-C225, an anti-epidermal growth factor receptor monoclonal antibody, for treatment of head and neck cancer.

    PubMed

    Herbst, R S; Kim, E S; Harari, P M

    2001-07-01

    Squamous cell carcinoma (SCC) of the head and neck (H&N) remains a clinical challenge due to its high rate of locoregional disease recurrence. The importance of the epidermal growth factor receptor (EGFR) in the development and progression of many solid tumours (including SCC of the H&N) is well understood; increased expression is associated with enhanced tumour invasion, resistance to chemotherapy and decreased patient survival. Several approaches have been developed to achieve EGFR blockade as an anticancer treatment strategy, including an anti-EGFR monoclonal antibody (mAb), IMC-C225, which competitively binds to the extracellular receptor site to prevent binding by natural EGFR ligands (EGF and TGF-alpha). Preclinical studies evaluating this chimeric mAb in human cancer cell lines in vitro and human tumour xenografts in vivo have demonstrated its potent antitumour activity. The clinical efficacy of IMC-C225 appears to involve multiple anticancer mechanisms, including inhibition of cell cycle progression, induction of apoptosis, anti-angiogenesis, inhibition of metastasis and its ability to enhance the response to chemotherapy and radiation therapy. Phase I studies of IMC-C225 combined with chemotherapy or radiation for SCC of the H&N demonstrate excellent response rates in patients with recurrent or refractory disease. Phase II and III trials examining the efficacy and safety of these combinations are currently underway. To date, IMC-C225 has been well-tolerated, with skin rashes and allergic reactions being the most clinically important adverse events reported. IMC-C225 displays dose-dependent elimination characteristics and a half-life of approximately 7 days. Current recommendations for dosing include a 400 mg/m2 loading dose, followed by weekly infusions of 250 mg/m2.

  11. Association between vascular-poor area of primary tumors and epidermal growth factor receptor gene status in advanced lung adenocarcinoma.

    PubMed

    Togashi, Yosuke; Masago, Katsuhiro; Kubo, Takeshi; Fujimoto, Daichi; Sakamori, Yuichi; Nagai, Hiroki; Kim, Young Hak; Togashi, Kaori; Mishima, Michiaki

    2012-12-01

    Mutation of the epidermal growth factor receptor gene (EGFR mutation) is a very important marker in the treatment for non-small cell lung cancer. Since signaling from this receptor induces tumor-associated angiogenesis, we hypothesized that lung cancers with EGFR mutations tend to develop locally with increased angiogenesis. Thus, the association between vascular-poor area of primary tumors and EGFR status was retrospectively investigated in advanced lung adenocarcinomas. To assess vascular-poor area, contrast-enhanced computed tomography scans taken before initial treatment for lung cancer were analyzed, together with primary tumor location (peripheral or central) and size. We analyzed 178 patients with advanced lung adenocarcinoma. EGFR mutations were detected in 95 of the 178 patients (53.4 %). EGFR mutation was found to be significantly related to women (P = 0.0070), never-smokers (P < 0.0001), and tumors without vascular-poor area (P < 0.0001). Based on a multivariate analysis, presence of EGFR mutations was independently associated with never-smokers (P = 0.0046), lack of vascular-poor area (P = 0.0001), and tumor size >30 mm (P = 0.0080). EGFR mutations were found in 41 of 51 never-smokers without vascular-poor area (80.4 %), 19 of 36 never-smokers with vascular-poor area (52.8 %), 19 of 37 current or former-smokers without vascular-poor area (51.4 %), and 16 of 54 current or former-smokers with vascular-poor area (29.6 %). This study showed an association between vascular-poor area of primary tumors and EGFR status. As a consequence, evaluation using a combination of smoking status and vascular-poor area allows us to predict presence of EGFR mutations at a high frequency.

  12. Breast milk protects against the development of necrotizing enterocolitis through inhibition of Toll Like Receptor 4 in the intestinal epithelium via activation of the epidermal growth factor receptor

    PubMed Central

    Good, Misty; Sodhi, Chhinder P.; Egan, Charlotte E.; Afrazi, Amin; Jia, Hongpeng; Yamaguchi, Yukihiro; Lu, Peng; Branca, Maria F.; Ma, Congrong; Prindle, Thomas; Mielo, Samantha; Pompa, Anthony; Hodzic, Zerina; Ozolek, John A.; Hackam, David J.

    2015-01-01

    Breast milk is the most effective strategy to protect infants against necrotizing enterocolitis (NEC), a devastating disease which is characterized by severe intestinal necrosis. Previous studies have demonstrated that the lipopolysaccharide receptor toll-like receptor 4 (TLR4) plays a critical role in NEC development via deleterious effects on mucosal injury and repair. We now hypothesize that breast milk protects against NEC by inhibiting TLR4 within the intestinal epithelium, and sought to determine the mechanisms involved. Breast milk protected against NEC and reduced TLR4 signaling in wild-type neonatal mice, but not in mice lacking the epidermal growth factor receptor (EGFR), while selective removal of EGF from breast milk reduced its protective properties, indicating that breast milk inhibits NEC and attenuates TLR4 signaling via EGF/EGFR activation. Over-expression of TLR4 in the intestinal epithelium reversed the protective effects of breast milk. The protective effects of breast milk occurred via inhibition of enterocyte apoptosis and restoration of enterocyte proliferation. Importantly, in IEC-6 enterocytes, breast milk inhibited TLR4 signaling via inhibition of GSK3β. Taken together, these findings offer mechanistic insights into the protective role for breast milk in NEC, and support a link between growth factor and innate immune receptors in NEC pathogenesis. PMID:25899687

  13. Epidermal Growth Factor Receptor and Transforming Growth Factor-β Signaling Contributes to Variation for Wing Shape in Drosophila melanogaster

    PubMed Central

    Dworkin, Ian; Gibson, Greg

    2006-01-01

    Wing development in Drosophila is a common model system for the dissection of genetic networks and their roles during development. In particular, the RTK and TGF-β regulatory networks appear to be involved with numerous aspects of wing development, including patterning, cell determination, growth, proliferation, and survival in the developing imaginal wing disc. However, little is known as to how subtle changes in the function of these genes may contribute to quantitative variation for wing shape, per se. In this study 50 insertional mutations, representing 43 loci in the RTK, Hedgehog, TGF-β pathways, and their genetically interacting factors were used to study the role of these networks on wing shape. To concurrently examine how genetic background modulates the effects of the mutation, each insertion was introgressed into two wild-type genetic backgrounds. Using geometric morphometric methods, it is shown that the majority of these mutations have profound effects on shape but not size of the wing when measured as heterozygotes. To examine the relationships between how each mutation affects wing shape hierarchical clustering was used. Unlike previous observations of environmental canalization, these mutations did not generally increase within-line variation relative to their wild-type counterparts. These results provide an entry point into the genetics of wing shape and are discussed within the framework of the dissection of complex phenotypes. PMID:16648592

  14. The Mediator Kinase Module Restrains Epidermal Growth Factor Receptor Signaling and Represses Vulval Cell Fate Specification in Caenorhabditis elegans.

    PubMed

    Grants, Jennifer M; Ying, Lisa T L; Yoda, Akinori; You, Charlotte C; Okano, Hideyuki; Sawa, Hitoshi; Taubert, Stefan

    2016-02-01

    Cell signaling pathways that control proliferation and determine cell fates are tightly regulated to prevent developmental anomalies and cancer. Transcription factors and coregulators are important effectors of signaling pathway output, as they regulate downstream gene programs. In Caenorhabditis elegans, several subunits of the Mediator transcriptional coregulator complex promote or inhibit vulva development, but pertinent mechanisms are poorly defined. Here, we show that Mediator's dissociable cyclin dependent kinase 8 (CDK8) module (CKM), consisting of cdk-8, cic-1/Cyclin C, mdt-12/dpy-22, and mdt-13/let-19, is required to inhibit ectopic vulval cell fates downstream of the epidermal growth factor receptor (EGFR)-Ras-extracellular signal-regulated kinase (ERK) pathway. cdk-8 inhibits ectopic vulva formation by acting downstream of mpk-1/ERK, cell autonomously in vulval cells, and in a kinase-dependent manner. We also provide evidence that the CKM acts as a corepressor for the Ets-family transcription factor LIN-1, as cdk-8 promotes transcriptional repression by LIN-1. In addition, we find that CKM mutation alters Mediator subunit requirements in vulva development: the mdt-23/sur-2 subunit, which is required for vulva development in wild-type worms, is dispensable for ectopic vulva formation in CKM mutants, which instead display hallmarks of unrestrained Mediator tail module activity. We propose a model whereby the CKM controls EGFR-Ras-ERK transcriptional output by corepressing LIN-1 and by fine tuning Mediator specificity, thus balancing transcriptional repression vs. activation in a critical developmental signaling pathway. Collectively, these data offer an explanation for CKM repression of EGFR signaling output and ectopic vulva formation and provide the first evidence of Mediator CKM-tail module subunit crosstalk in animals. PMID:26715664

  15. Tyrosine dephosphorylation enhances the therapeutic target activity of epidermal growth factor receptor (EGFR) by disrupting its interaction with estrogen receptor (ER).

    PubMed

    Ma, Shao; Yin, Ning; Qi, Xiaomei; Pfister, Sandra L; Zhang, Mei-Jie; Ma, Rong; Chen, Guan

    2015-05-30

    Protein-protein interactions can increase or decrease its therapeutic target activity and the determining factors involved, however, are largely unknown. Here, we report that tyrosine-dephosphorylation of epidermal growth factor receptor (EGFR) increases its therapeutic target activity by disrupting its interaction with estrogen receptor (ER). Protein tyrosine phosphatase H1 (PTPH1) dephosphorylates the tyrosine kinase EGFR, disrupts its interaction with the nuclear receptor ER, and increases breast cancer sensitivity to small molecule tyrosine kinase inhibitors (TKIs). These effects require PTPH1 catalytic activity and its interaction with EGFR, suggesting that the phosphatase may increase the sensitivity by dephosphorylating EGFR leading to its dissociation with ER. Consistent with this notion, a nuclear-localization defective ER has a higher EGFR-binding activity and confers the resistance to TKI-induced growth inhibition. Additional analysis show that PTPH1 stabilizes EGFR, stimulates the membranous EGFR accumulation, and enhances the growth-inhibitory activity of a combination therapy of TKIs with an anti-estrogen. Since EGFR and ER both are substrates for PTPH1 in vitro and in intact cells, these results indicate that an inhibitory EGFR-ER protein complex can be switched off through a competitive enzyme-substrate binding. Our results would have important implications for the treatment of breast cancer with targeted therapeutics.

  16. Tyrosine dephosphorylation enhances the therapeutic target activity of epidermal growth factor receptor (EGFR) by disrupting its interaction with estrogen receptor (ER)

    PubMed Central

    Ma, Shao; Yin, Ning; Qi, Xiaomei; Pfister, Sandra L.; Zhang, Mei-Jie; Ma, Rong; Chen, Guan

    2015-01-01

    Protein-protein interactions can increase or decrease its therapeutic target activity and the determining factors involved, however, are largely unknown. Here, we report that tyrosine-dephosphorylation of epidermal growth factor receptor (EGFR) increases its therapeutic target activity by disrupting its interaction with estrogen receptor (ER). Protein tyrosine phosphatase H1 (PTPH1) dephosphorylates the tyrosine kinase EGFR, disrupts its interaction with the nuclear receptor ER, and increases breast cancer sensitivity to small molecule tyrosine kinase inhibitors (TKIs). These effects require PTPH1 catalytic activity and its interaction with EGFR, suggesting that the phosphatase may increase the sensitivity by dephosphorylating EGFR leading to its dissociation with ER. Consistent with this notion, a nuclear-localization defective ER has a higher EGFR-binding activity and confers the resistance to TKI-induced growth inhibition. Additional analysis show that PTPH1 stabilizes EGFR, stimulates the membranous EGFR accumulation, and enhances the growth-inhibitory activity of a combination therapy of TKIs with an anti-estrogen. Since EGFR and ER both are substrates for PTPH1 in vitro and in intact cells, these results indicate that an inhibitory EGFR-ER protein complex can be switched off through a competitive enzyme-substrate binding. Our results would have important implications for the treatment of breast cancer with targeted therapeutics. PMID:26079946

  17. Disconnecting the Yin and Yang Relation of Epidermal Growth Factor Receptor (EGFR)-Mediated Delivery: A Fully Synthetic, EGFR-Targeted Gene Transfer System Avoiding Receptor Activation

    PubMed Central

    Schäfer, A.; Pahnke, A.; Schaffert, D.; van Weerden, W.M.; de Ridder, C.M.A.; Rödl, W.; Vetter, A.; Spitzweg, C.; Kraaij, R.; Wagner, E.

    2011-01-01

    Abstract The epidermal growth factor receptor (EGFR) is upregulated within a high percentage of solid tumors and hence is an attractive target for tumor-targeted therapies including gene therapy. The natural EGFR ligand epidermal growth factor (EGF) has been used for this purpose, despite the risk of mitogenic effects due to EGFR activation. We have developed a fully synthetic, EGFR-targeted gene delivery system based on PEGylated linear polyethylenimine (LPEI), allowing evaluation of different EGFR-binding peptides in terms of transfection efficiency and EGFR activation. Peptide sequences directly derived from the human EGF molecule enhanced transfection efficiency with concomitant EGFR activation. Only the EGFR-binding peptide GE11, which has been identified by phage display technique, showed specific enhancement of transfection on EGFR-overexpressing tumor cells including glioblastoma and hepatoma, but without EGFR activation. EGFR targeting led to high levels of cell association of fluorescently labeled polyplexes after only 30 min of incubation. EGF pretreatment of cells induced enhanced cellular internalization of all polyplex types tested, pointing at generally enhanced macropinocytosis. EGF polyplexes diminished cell surface expression of EGFR for up to 4 hr, whereas GE11 polyplexes did not. In a clinically relevant orthotopic prostate cancer model, intratumorally injected GE11 polyplexes were superior in inducing transgene expression when compared with untargeted polyplexes. PMID:21644815

  18. Excessive Reversal of Epidermal Growth Factor Receptor and Ephrin Signaling Following Tracheal Occlusion in Rabbit Model of Congenital Diaphragmatic Hernia

    PubMed Central

    Varisco, Brian M; Sbragia, Lourenco; Chen, Jing; Scorletti, Federico; Joshi, Rashika; Wong, Hector R; Lopes-Figueira, Rebeca; Oria, Marc; Peiro, Jose

    2016-01-01

    Congenital diaphragmatic hernia (CDH) causes severe pulmonary hypoplasia from herniation of abdominal contents into the thorax. Tracheal occlusion (TO) for human CDH improves survival, but morbidity and mortality remain high, and we do not fully understand the cellular pathways and processes most severely impacted by CDH and TO. We created a left diaphragmatic hernia (DH) in rabbit fetuses with subsequent TO and collected left lung sections for NextGen mRNA sequencing. DH, TO and DHTO fetuses had comparable body and organ growth to control except for lower lung weights in DH (p < 0.05). Of 13,687 expressed genes, DHTO had 687 differentially expressed genes compared with DH, but no other group-group comparison had more than 10. Considering genes in combination, many of the genes reduced in DH were more highly expressed in DHTO than in control. Benchmarking fetal rabbit lung gene expression to published lung development data, both DH and DHTO lungs were more highly correlated with the gene expression of immature lung. DNA synthesis was upregulated in DHTO compared with DH and ribosome and protein synthesis pathways were downregulated. DH reduced total and epithelial cell proliferation by half and two-thirds respectively, and DHTO increased proliferation by 2.5 and 3.4-fold respectively. Signaling pathways downregulated by DH and upregulated in DHTO were epidermal growth factor receptor signaling, ephrin signaling and cell migration; however, levels of ephrin and EGFR signaling in DHTO exceeded that of control. Identification and inhibition of the ligands responsible for this dysregulated signaling could improve lung development in CDH. PMID:27452320

  19. Development of an affinity-matured humanized anti-epidermal growth factor receptor antibody for cancer immunotherapy.

    PubMed

    Nakanishi, Takeshi; Maru, Takamitsu; Tahara, Kazuhiro; Sanada, Hideaki; Umetsu, Mitsuo; Asano, Ryutaro; Kumagai, Izumi

    2013-02-01

    We showed previously that humanization of 528, a murine anti-epidermal growth factor receptor (EGFR) antibody, causes reduced affinity for its target. Here, to improve the affinity of the humanized antibody for use in cancer immunotherapy, we constructed phage display libraries focused on the complementarity-determining regions (CDRs) of the antibody and carried out affinity selection. Two-step selections using libraries constructed in a stepwise manner enabled a 32-fold affinity enhancement of humanized 528 (h528). Thermodynamic analysis of the interactions between the variable domain fragment of h528 (h528Fv) mutants and the soluble extracellular domain of EGFR indicated that the h528Fv mutants obtained from the first selection showed a large increase in negative enthalpy change due to binding, resulting in affinity enhancement. Furthermore, mutants from the second selection showed a decrease in entropy loss, which led to further affinity maturation. These results suggest that a single mutation in the heavy chain variable domain (i.e. Tyr(52) to Trp) enthalpically contributed for overcoming the energetic barrier to the antigen-antibody interaction, which was a major hurdle for the in vitro affinity maturation of h528. We reported previously that the humanized bispecific diabody hEx3 Db, which targets EGFR and CD3, shows strong anti-tumor activity. hEx3 Db mutants, in which the variable domains of h528 were replaced with those of the affinity-enhanced mutants, were prepared and characterized. In a growth inhibition assay of tumor cells, the hEx3 Db mutants showed stronger anti-tumor activity than that of hEx3 Db, suggesting that affinity enhancement of h528Fv enhances the anti-tumor activity of the bispecific diabody. PMID:23118340

  20. Attribution to Heterogeneous Risk Factors for Breast Cancer Subtypes Based on Hormone Receptor and Human Epidermal Growth Factor 2 Receptor Expression in Korea.

    PubMed

    Park, Boyoung; Choi, Ji-Yeob; Sung, Ho Kyung; Ahn, Choonghyun; Hwang, Yunji; Jang, Jieun; Lee, Juyeon; Kim, Heewon; Shin, Hai-Rim; Park, Sohee; Han, Wonshik; Noh, Dong-Young; Yoo, Keun-Young; Kang, Daehee; Park, Sue K

    2016-04-01

    We conducted a heterogeneous risk assessment of breast cancer based on the hormone receptor (HR) and human epidermal growth factor receptor 2 (HER2) calculating the risks and population-based attributable fractions (PAFs) for modifiable and nonmodifiable factors.Using matched case-control study design from the Seoul Breast Cancer Study and the national prevalence of exposure, the risks and PAFs for modifiable and nonmodifiable factors were estimated for total breast cancers and subtypes.The attribution to modifiable factors was different for each subtype (luminal A, PAF = 61.4% [95% confidence interval, CI = 54.3%-69.8%]; luminal B, 21.4% [95% CI = 18.6-24.9%]; HER2-overexpression, 59.4% [95% CI = 47.8%-74.3%], and triple negative tumors [TNs], 27.1% [95% CI = 22.9%-32.4%)], and the attribution to the modifiable factors for the luminal A and HER2-overexpression subtypes was higher than that of the luminal B and TN subtypes (P heterogeneity  ≤  0.001). The contribution of modifiable reproductive factors to luminal A type in premenopausal women was higher than that of the other subtypes (18.2% for luminal A; 3.1%, 8.1%, and -3.1% for luminal B, HER2-overexpression, and TN subtypes, respectively; P heterogeneity  ≤  0.001). Physical activity had the highest impact preventing 32.6% of luminal A, 14.5% of luminal B, 38.0% of HER2-overexpression, and 26.9% of TN subtypes (P heterogeneity = 0.014). Total reproductive factors were also heterogeneously attributed to each breast cancer subtype (luminal A, 65.4%; luminal B, 24.1%; HER2-overexpression, 57.9%, and TN subtypes, -3.1%; P heterogeneity  ≤  0.001).Each pathological subtype of breast cancer by HRs and HER2 status may be associated with heterogeneous risk factors and their attributable risk, suggesting a different etiology. The luminal B and TN subtypes seemed to be less preventable despite intervention for alleged risk factors, even though physical activity had a high

  1. Attribution to Heterogeneous Risk Factors for Breast Cancer Subtypes Based on Hormone Receptor and Human Epidermal Growth Factor 2 Receptor Expression in Korea

    PubMed Central

    Park, Boyoung; Choi, Ji-Yeob; Sung, Ho Kyung; Ahn, Choonghyun; Hwang, Yunji; Jang, Jieun; Lee, Juyeon; Kim, Heewon; Shin, Hai-Rim; Park, Sohee; Han, Wonshik; Noh, Dong-Young; Yoo, Keun-Young; Kang, Daehee; Park, Sue K.

    2016-01-01

    Abstract We conducted a heterogeneous risk assessment of breast cancer based on the hormone receptor (HR) and human epidermal growth factor receptor 2 (HER2) calculating the risks and population-based attributable fractions (PAFs) for modifiable and nonmodifiable factors. Using matched case–control study design from the Seoul Breast Cancer Study and the national prevalence of exposure, the risks and PAFs for modifiable and nonmodifiable factors were estimated for total breast cancers and subtypes. The attribution to modifiable factors was different for each subtype (luminal A, PAF = 61.4% [95% confidence interval, CI = 54.3%–69.8%]; luminal B, 21.4% [95% CI = 18.6–24.9%]; HER2-overexpression, 59.4% [95% CI = 47.8%–74.3%], and triple negative tumors [TNs], 27.1% [95% CI = 22.9%–32.4%)], and the attribution to the modifiable factors for the luminal A and HER2-overexpression subtypes was higher than that of the luminal B and TN subtypes (P heterogeneity ≤ 0.001). The contribution of modifiable reproductive factors to luminal A type in premenopausal women was higher than that of the other subtypes (18.2% for luminal A; 3.1%, 8.1%, and −3.1% for luminal B, HER2-overexpression, and TN subtypes, respectively; P heterogeneity ≤ 0.001). Physical activity had the highest impact preventing 32.6% of luminal A, 14.5% of luminal B, 38.0% of HER2-overexpression, and 26.9% of TN subtypes (P heterogeneity = 0.014). Total reproductive factors were also heterogeneously attributed to each breast cancer subtype (luminal A, 65.4%; luminal B, 24.1%; HER2-overexpression, 57.9%, and TN subtypes, −3.1%; P heterogeneity ≤ 0.001). Each pathological subtype of breast cancer by HRs and HER2 status may be associated with heterogeneous risk factors and their attributable risk, suggesting a different etiology. The luminal B and TN subtypes seemed to be less preventable despite intervention for alleged risk factors, even though physical

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

    PubMed

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

    2012-01-01

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

  3. Upregulation of retinoic acid receptor-beta by the epidermal growth factor-receptor inhibitor PD153035 is not mediated by blockade of ErbB pathways.

    PubMed

    Grunt, Thomas W; Tomek, Katharina; Wagner, Renate; Puckmair, Klaudia; Kainz, Birgit; Rünzler, Dominik; Gaiger, Alexander; Köhler, Gottfried; Zielinski, Christoph C

    2007-06-01

    Inhibiting epidermal growth factor-receptor (ErbB-1) represents a powerful anticancer strategy. Activation of retinoid pathways is also in development for cancer treatment. Retinoic acid receptor-beta-the tumor suppressor and main retinoid mediator--is silenced in many tumors. The ErbB-1 inhibitor PD153035 cooperates with retinoic acid during growth inhibition and induces retinoic acid receptor-beta suggesting that ErbB-1 controls retinoic acid receptor-beta. However, here we demonstrate that ErbB pathways are not involved in PD153035-mediated retinoic acid receptor-beta-upregulation. PD153035 inhibits ErbB-1-phosphorylation, whereas its derivative EBE-A22 is inactive. Yet both inhibit cell growth and upregulate retinoic acid receptor-beta in ErbB-1-overexpressing (MDA-MB-468), moderately expressing (OVCAR-3), ErbB-1-negative (MDA-MB-453) or ErbB-negative cells (CEM, Jurkat). Both bind DNA, whereas the closely related ErbB-1 inhibitors AG1478 and ZD1839, which are inactive on retinoic acid receptor-beta, do not significantly bind DNA. None of the other ErbB-1/ErbB-2 inhibitors tested (RG-14620, LFM-A12, AG879, AG825) affect retinoic acid receptor-beta. PD153035 decreases methylation of the retinoic acid receptor-beta2 promoter. In OVCAR-3, it stimulates dislodgement of histone deacetylase 1 from the promoter and acetylation of histones H3 and H4. Consequently, PD153035 facilitates recruitment of RNA polymerase II to the promoter and stimulates transcriptional activity. Moreover, PD153035 increases the retinoic acid receptor-beta mRNA half-life. No other retinoid receptor, nor estrogen receptor-alpha, nor RASSF1A is upregulated by PD153035. Thus PD153035 induces retinoic acid receptor-beta by ErbB-independent transcriptional and post-transcriptional mechanisms. This report highlights a triple action for an ErbB-1 inhibitor (ErbB-1 inhibition, DNA intercalation, retinoic acid receptor-beta-induction). Such multitargeting drugs bear great potential for cancer

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed Central

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

    2016-01-01

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

  6. Fluorogen activating protein-affibody probes: modular, no-wash measurement of epidermal growth factor receptors.

    PubMed

    Wang, Yi; Telmer, Cheryl A; Schmidt, Brigitte F; Franke, Josef D; Ort, Stephan; Arndt-Jovin, Donna J; Bruchez, Marcel P

    2015-01-21

    Fluorescence is essential for dynamic live cell imaging, and affinity reagents are required for quantification of endogenous proteins. Various fluorescent dyes can report on different aspects of biological trafficking, but must be independently conjugated to affinity reagents and characterized for specific biological readouts. Here we present the characterization of a new modular platform for small anti-EGFR affinity probes for studying rapid changes in receptor pools. A protein domain (FAP dL5**) that binds to malachite-green (MG) derivatives for fluorescence activation was expressed as a recombinant fusion to one or two copies of the compact EGFR binding affibody ZEGFR:1907. This is a recombinant and fluorogenic labeling reagent for native EGFR molecules. In vitro fluorescence assays demonstrated that the binding of these dyes to the FAP-affibody fusions produced thousand-fold fluorescence enhancements, with high binding affinity and fast association rates. Flow cytometry assays and fluorescence microscopy demonstrated that these probes label endogenous EGFR on A431 cells without disruption of EGFR function, and low nanomolar surface Kd values were observed with the double-ZEGFR:1907 constructs. The application of light-harvesting fluorogens (dyedrons) significantly improved the detected fluorescence signal. Altering the order of addition of the ligand, probe, and dyes allowed differentiation between surface and endocytotic pools of receptors to reveal the rapid dynamics of endocytic trafficking. Therefore, FAP/affibody coupling provides a new approach to construct compact and modular affinity probes that label endogenous proteins on living cells and can be used for studying rapid changes in receptor pools involved in trafficking. PMID:25490520

  7. Fluorogen Activating Protein–Affibody Probes: Modular, No-Wash Measurement of Epidermal Growth Factor Receptors

    PubMed Central

    2015-01-01

    Fluorescence is essential for dynamic live cell imaging, and affinity reagents are required for quantification of endogenous proteins. Various fluorescent dyes can report on different aspects of biological trafficking, but must be independently conjugated to affinity reagents and characterized for specific biological readouts. Here we present the characterization of a new modular platform for small anti-EGFR affinity probes for studying rapid changes in receptor pools. A protein domain (FAP dL5**) that binds to malachite-green (MG) derivatives for fluorescence activation was expressed as a recombinant fusion to one or two copies of the compact EGFR binding affibody ZEGFR:1907. This is a recombinant and fluorogenic labeling reagent for native EGFR molecules. In vitro fluorescence assays demonstrated that the binding of these dyes to the FAP–affibody fusions produced thousand-fold fluorescence enhancements, with high binding affinity and fast association rates. Flow cytometry assays and fluorescence microscopy demonstrated that these probes label endogenous EGFR on A431 cells without disruption of EGFR function, and low nanomolar surface Kd values were observed with the double-ZEGFR:1907 constructs. The application of light-harvesting fluorogens (dyedrons) significantly improved the detected fluorescence signal. Altering the order of addition of the ligand, probe, and dyes allowed differentiation between surface and endocytotic pools of receptors to reveal the rapid dynamics of endocytic trafficking. Therefore, FAP/affibody coupling provides a new approach to construct compact and modular affinity probes that label endogenous proteins on living cells and can be used for studying rapid changes in receptor pools involved in trafficking. PMID:25490520

  8. Significance of Epidermal Growth Factor Receptor in the Radiation Resistance of Glioblastoma Tumors

    NASA Astrophysics Data System (ADS)

    Petrás, Miklós; Lajtos, Tamás; Pintye, Éva; Feuerstein, Burt G.; Szöllősi, János; Vereb, György

    2008-12-01

    In the United States, a dramatically increased incidence and mortality of brain tumors have been observed over the past decades. Of the ˜44 thousand new cases of primary malignant and benign brain tumors diagnosed per year, high grade astrocytomas or multiform glioblastomas show particularly bad prognosis in spite of therapeutic developments. Current management of multiform glioblastoma includes the most extensive surgical resection possible, followed by adjuvant radio- and chemotherapy. However, treatment is frequently hampered by decreased radiosensitivity of the tumor. Recent studies revealed that subpopulations of glioblastoma cells show amplified checkpoint activation of the cell cycle upon ionizing radiation, which induces overactivation of DNA repair processes and leads to maintained proliferation rate as well as clinically observed radioresistance and recurrence of the tumor over time. In addition, overexpression of some transmembrane receptors has also been implicated in radioresistance. However, the role of the overexpressed proteins can only be interpreted reliably if their multi-faceted molecular interactions are properly characterized. Thus, based on recent evidence for the functional crosstalk between certain cell adhesion molecules and receptor tyrosine kinases, we have examined the molecular interactions of the receptor tyrosine kinase EGFR and the cell adhesion molecule β1-integrin using flow cytometric and microscopic fluorescence resosnance energy transfer (FRET) measurements on two cellular model systems showing similar expression patterns to low and high grade astrocytomas. On the one hand, U251 glioblastoma clones established by introducing varying amounts of extra chromosome 7 into the cells, and on the other hand stable, high and low EGFR expressing transfenctant U251 NCI sublines were investigated. The results revealed that increased EGFR and β1-integrin expression levels correlate with stronger EGFR—β1-integrin heteroassociation

  9. Anti-synthetic peptide antibody reacting at the fusion junction of deletion-mutant epidermal growth factor receptors in human glioblastoma

    SciTech Connect

    Humphrey, P.A.; Zalutsky, M.R.; Fuller, G.N.; Archer, G.E.; Friedman, H.S.; Kwatra, M.M.; Bigner, S.H.; Bigner, D.D. ); Wong, A.J. ); Vogelstein, B. )

    1990-06-01

    The authors have investigated human gliomas that amplify and rearrange the epidermal growth factor receptor gene, with generation of an in-frame deletion mutation of 802 nucleotides in the external domain. This in-frame deletion mutation generates a local amino acid sequence at the fusion junction of what normally were distant polypeptide sequences in the intact epidermal growth factor receptor. This 14-amino acid peptide was chemically synthesized, coupled to keyhole limpet hemocyanin, and used as an immunogen in rabbits. The elicited antibody reacted specifically with the fusion peptide in ELISA. The anti-fusion junction peptide antibody was purified by passage of the antiserum over a peptide affinity column with acidic elution. The purified antibody selectively bound the glioma deletion mutant as compared to the intact epidermal growth factor receptor as assessed by immunocytochemistry, immunofluorescence, immunoprecipitation with gel electrophoresis, and binding experiments using radioiodinated antibody. These data indicate that it is feasible to generate site-specific anti-peptide antibodies that are highly selective for mutant proteins in human tumors. The anti-peptide antibody described here, and other mutation site-specific antibodies, should be ideal candidates for tumor immunoimaging and immunotherapy.

  10. Epidermal growth factor receptor activation by diesel particles is mediated by tyrosine phosphatase inhibition

    SciTech Connect

    Tal, Tamara L.; Bromberg, Philip A.; Kim, Yumee; Samet, James M.

    2008-12-15

    Exposure to particulate matter (PM) is associated with increased cardiopulmonary morbidity and mortality. Diesel exhaust particles (DEP) are a major component of ambient PM and may contribute to PM-induced pulmonary inflammation. Proinflammatory signaling is mediated by phosphorylation-dependent signaling pathways whose activation is opposed by the activity of protein tyrosine phosphatases (PTPases) which thereby function to maintain signaling quiescence. PTPases contain an invariant catalytic cysteine that is susceptible to electrophilic attack. DEP contain electrophilic oxy-organic compounds that may contribute to the oxidant effects of PM. Therefore, we hypothesized that exposure to DEP impairs PTPase activity allowing for unopposed basal kinase activity. Here we report that exposure to 30 {mu}g/cm{sup 2} DEP for 4 h induces differential activation of signaling in primary cultures of human airway epithelial cells (HAEC), a primary target cell in PM inhalation. In-gel kinase activity assay of HAEC exposed to DEPs of low (L-DEP), intermediate (I-DEP) or high (H-DEP) organic content showed differential activation of intracellular kinases. Exposure to these DEP also induced varying levels of phosphorylation of the receptor tyrosine kinase EGFR in a manner that requires EGFR kinase activity but does not involve receptor dimerization. We demonstrate that treatment with DEP results in an impairment of total and EGFR-directed PTPase activity in HAEC with a potency that is independent of the organic content of these particles. These data show that DEP-induced EGFR phosphorylation in HAEC is the result of a loss of PTPase activities which normally function to dephosphorylate EGFR in opposition to baseline EGFR kinase activity.

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

    PubMed

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

    2014-06-01

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

  12. The epidermal growth factor receptors as biological targets in penile cancer.

    PubMed

    Di Lorenzo, Giuseppe; Buonerba, Carlo; Ferro, Matteo; Calderoni, Giuseppe; Bozza, Giovanni; Federico, Piera; Tedesco, Beatrice; Ruggieri, Vitalba; Aieta, Michele

    2015-04-01

    Penile cancer is a rare disease, with an incidence that is higher in less developed countries and is in the range of 1 - 10 per 100000 men worldwide. Early diagnosis is essential for cure, as 5 year cancer-specific survival is 90 - 100 % in patients with intraepithelial neoplasms and in those with low-grade superficial tumors without lymphovascular invasion, but it drops to 30% in men with multiple mobile or bilateral inguinal lymph nodes. The EGFR family plays a major role in penile cancer biology, with distinct receptors being involved in HPV-positive and -negative tumors. A number of anti-EGFR agents were used in penile cancer patients outside the context of a clinical trial, mainly as a salvage treatment after failure of first-line chemotherapy. A total of 28 patients received anti-EGFR monoclonal antibodies, with 50% of them showing a response to treatment, and a median PFS of ∼ 3 months. The rarity of the disease poses great challenge in terms of education and awareness of the general population, planning of preventive measures on a large scale, as well as conduction of prospective trials and approval of high-cost biological therapy. PMID:25496291

  13. Mechanisms for kinase-mediated dimerization of the epidermal growth factor receptor.

    PubMed

    Lu, Chafen; Mi, Li-Zhi; Schürpf, Thomas; Walz, Thomas; Springer, Timothy A

    2012-11-01

    We study a mechanism by which dimerization of the EGF receptor (EGFR) cytoplasmic domain is transmitted to the ectodomain. Therapeutic and other small molecule antagonists to the kinase domain that stabilize its active conformation, but not those that stabilize an inactive conformation, stabilize ectodomain dimerization. Inhibitor-induced dimerization requires an asymmetric kinase domain interface associated with activation. EGF and kinase inhibitors stimulate formation of identical dimer interfaces in the EGFR transmembrane domain, as shown by disulfide cross-linking. Disulfide cross-linking at an interface in domain IV in the ectodomain was also stimulated similarly; however, EGF but not inhibitors stimulated cross-linking in domain II. Inhibitors similarly induced noncovalent dimerization in nearly full-length, detergent-solubilized EGFR as shown by gel filtration. EGFR ectodomain deletion resulted in spontaneous dimerization, whereas deletion of exons 2-7, in which extracellular domains III and IV are retained, did not. In EM, kinase inhibitor-induced dimers lacked any well defined orientation between the ectodomain monomers. Fab of the therapeutic antibody cetuximab to domain III confirmed a variable position and orientation of this domain in inhibitor-induced dimers but suggested that the C termini of domain IV of the two monomers were in close proximity, consistent with dimerization in the transmembrane domains. The results provide insights into the relative energetics of intracellular and extracellular dimerization in EGFR and have significance for physiologic dimerization through the asymmetric kinase interface, bidirectional signal transmission in EGFR, and mechanism of action of therapeutics.

  14. ImmunoPET and biodistribution with human epidermal growth factor receptor 3 targeting antibody ⁸⁹Zr-RG7116.

    PubMed

    Terwisscha van Scheltinga, Anton G T; Lub-de Hooge, Marjolijn N; Abiraj, Keelara; Schröder, Carolien P; Pot, Linda; Bossenmaier, Birgit; Thomas, Marlene; Hölzlwimmer, Gabriele; Friess, Thomas; Kosterink, Jos G W; de Vries, Elisabeth G E

    2014-01-01

    The humanized monoclonal antibody with high affinity for the human epidermal growth factor receptor (HER) 3, RG7116, is a glycoengineered, IgG1 class antibody. By labeling RG7116 with zirconium-89 ((89)Zr) we aimed to visualize in vivo HER3 expression and study the biodistribution of this antibody in human tumor-bearing mice. Biodistribution of (89)Zr-RG7116 was studied in subcutaneously xenografted FaDu tumor cells (HER3-positive). Dose-dependency of (89)Zr-RG7116 organ distribution and specific tumor uptake was assessed by administering doses ranging from 0.05 to 10 mg/kg RG7116 to SCID/Beige mice. Biodistribution was analyzed at 24 and 144 h after injection. MicroPET imaging was performed at 1, 3, and 6 days after injection of 1.0 mg/kg (89)Zr-RG7116 in the FaDu, H441, QG-56 and Calu-1 xenografts with varying HER3 expression. The excised tumors were analyzed for HER3 expression. Biodistribution analyses showed a dose- and time-dependent (89)Zr-RG7116 tumor uptake in FaDu tumors. The highest tumor uptake of (89)Zr-RG7116 was observed in the 0.05 mg/kg dose group with 27.5%ID/g at 144 h after tracer injection. MicroPET imaging revealed specific tumor uptake of (89)Zr-RG7116 in FaDu and H441 models with an increase in tumor uptake over time. Biodistribution data was consistent with the microPET findings in FaDu, H441, QG56 and Calu-1 xenografts, which correlated with HER3 expression levels. In conclusion, (89)Zr-RG7116 specifically accumulates in HER3 expressing tumors. PET imaging with this tracer provides real-time non-invasive information about RG7116 distribution, tumor targeting and tumor HER3 expression levels.

  15. Prognostic Impact of Epidermal Growth Factor Receptor Overexpression in Patients with Cervical Cancer: A Meta-Analysis

    PubMed Central

    Huang, Miao-Ling; Qin, Qing-Feng; Chen, Qing; Fang, Kun; Wang, Ping-Ling

    2016-01-01

    Clinical trials have provided conflicting results regarding whether epidermal growth factor receptor (EGFR) overexpression predicts poor survival in cervical cancer patients. In this study, we perform a meta-analysis of the association between EGFR expression and survival in cervical cancer patients. We searched clinical studies in the Medline, PubMed, Embase, and Web of Science databases. A total of 22 studies with 2,505 patients were included, and pooled hazard ratios (HRs) with 95% confidence intervals (CIs) were calculated for each study. Heterogeneity was assessed using Higgins I2 to select a Mantel-Haenszel fixed effects model (I2 ≤50%) or a DerSimonian-Laird random effects model (I2 ≥50%). High EGFR levels predicted poor overall survival (OS) (HR: 1.40, 95% CI: 1.10–1.78) and disease-free survival (DFS) (HR: 1.84, 95% CI: 1.51–2.24). Stratified analyses showed that EGFR overexpression was significantly related to poor DFS in patients treated with chemoradiation or surgery. Moreover, the pooled odds ratios (ORs) revealed associations between EGFR expression and clinicopathological features, such as lymph node metastasis (OR: 1.72, 95% CI: 1.23–2.40) and tumor size ≥4 cm (OR: 1.64, 95% CI: 1.20–2.23). This meta-analysis demonstrates that EGFR overexpression is closely associated with reduced survival in patients with cervical cancer. These results may facilitate the individualized management of clinical decisions for anti-EGFR therapies in cervical cancer patients. PMID:27438047

  16. Expression and clinical significance of P53, O6-methylguanine-dna methyltransferase and epidermal growth factor receptor in glioma.

    PubMed

    Fu, X R; Sun, Z C; Chang, Y

    2015-01-01

    Glioma is a serious life-threatening disease, the pathogenesis of which remains to be investigated. The objective of the present investigation was to explore the expression and clinical significance of tumor suppressor gene (P53), O6-methylguanine-DNA methyltransferase (MGMT) and epidermal growth factor receptor (EGFR) in glioma. Immunohistochemical staining was applied to study the clinical characteristics of 40 samples from glioma patients, detect the expression of and analyse the relationship between P53, MGMT and EGFR and glioma. The results demonstrated that the positive expression rate of P53 was 47.5% in 40 cases of glioma samples, of which the expression of P53 in the high grade glioma was higher than that of the low grade samples (P < 0.05); the positive expression rate of MGMT was 37.5%, but there was no significant significance of MGMT expression between the high grade glioma and the low grade glioma (P < 0.05); the positive expression rate of EGFR was 55%, of which the expression of EGFR of the high grade glioma was higher than that of the low grade glioma (P < 0.05). There was no significant difference in the expressions of P53, MGMT and EGFR in the glioma patients of different ages, gender and with different tumor sizes. The expressions of P53 and MGMT were negatively correlated (P < 0.05). The expressions of P53 and EGFR were positively correlated (P < 0.05). In conclusion, P53, EGFR and MGMT could play a role in the occurrence, development and deterioration of glioma. PMID:26753647

  17. Role of epidermal growth factor receptor and endoplasmic reticulum stress in vascular remodeling induced by angiotensin II.

    PubMed

    Takayanagi, Takehiko; Kawai, Tatsuo; Forrester, Steven J; Obama, Takashi; Tsuji, Toshiyuki; Fukuda, Yamato; Elliott, Katherine J; Tilley, Douglas G; Davisson, Robin L; Park, Joon-Young; Eguchi, Satoru

    2015-06-01

    The mechanisms by which angiotensin II (AngII) elevates blood pressure and enhances end-organ damage seem to be distinct. However, the signal transduction cascade by which AngII specifically mediates vascular remodeling such as medial hypertrophy and perivascular fibrosis remains incomplete. We have previously shown that AngII-induced epidermal growth factor receptor (EGFR) transactivation is mediated by disintegrin and metalloproteinase domain 17 (ADAM17), and that this signaling is required for vascular smooth muscle cell hypertrophy but not for contractile signaling in response to AngII. Recent studies have implicated endoplasmic reticulum (ER) stress in hypertension. Interestingly, EGFR is capable of inducing ER stress. The aim of this study was to test the hypothesis that activation of EGFR and ER stress are critical components required for vascular remodeling but not hypertension induced by AngII. Mice were infused with AngII for 2 weeks with or without treatment of EGFR inhibitor, erlotinib, or ER chaperone, 4-phenylbutyrate. AngII infusion induced vascular medial hypertrophy in the heart, kidney and aorta, and perivascular fibrosis in heart and kidney, cardiac hypertrophy, and hypertension. Treatment with erlotinib as well as 4-phenylbutyrate attenuated vascular remodeling and cardiac hypertrophy but not hypertension. In addition, AngII infusion enhanced ADAM17 expression, EGFR activation, and ER/oxidative stress in the vasculature, which were diminished in both erlotinib-treated and 4-phenylbutyrate-treated mice. ADAM17 induction and EGFR activation by AngII in vascular cells were also prevented by inhibition of EGFR or ER stress. In conclusion, AngII induces vascular remodeling by EGFR activation and ER stress via a signaling mechanism involving ADAM17 induction independent of hypertension.

  18. Prediction of response to chemoradiation in rectal cancer by a gene polymorphism in the epidermal growth factor receptor promoter region

    SciTech Connect

    Spindler, Karen-Lise Garm . E-mail: kalgsp@vgs.vejleamt.dk; Nielsen, Jens Nederby; Lindebjerg, Jan; Brandslund, Ivan; Jakobsen, Anders

    2006-10-01

    Purpose: Epidermal growth factor receptor (EGFR) has been associated with radioresistance in solid tumors. Recently a polymorphism in the Sp1 recognition site of the EGFR promoter region was identified. The present study investigated the predictive value of this polymorphism for the outcome of chemoradiation in locally advanced rectal cancer. Methods and Materials: The study included 77 patients with locally advanced T3 rectal tumors. Treatment consisted of preoperative radiation therapy at a total tumor dose of 65 Gy and concomitant chemotherapy with Uftoral. Blood samples from 63 patients were evaluated for Sp1 -216 G/T polymorphism by polymerase chain reaction analysis. Forty-eight primary tumor biopsies were available for EGFR immunostaining. Patients underwent surgery 8 weeks after treatment. Pathologic response evaluation was performed according to the tumor regression grade (TRG) system. Results: Forty-nine percent had major response (TRG1-2) and 51% moderate response (TRG 3-4) to chemoradiation. The rates of major response were 34% (10/29) in GG homozygote patients compared with 65% (22/34) in patients with T containing variants (p = 0.023). Fifty-eight percent of biopsies were positive for EGFR expression (28/48). The major response rates with regard to EGFR immunostaining were not significantly different. EGFR-positive tumors were found in 83% of the GG homozygote patients compared with 38% of patients with TT or GT variants (p = 0.008). Conclusions: There was a significant correlation between EGFR Sp1 -216 G/T polymorphism and treatment response to chemoradiation in locally advanced rectal cancer. Further investigations of a second set of patient and other treatment schedules are warranted.

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

    PubMed Central

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

    1998-01-01

    Formation of metastasis is a multistep process involving attachment to the basement membrane, local proteolysis and migration into surrounding tissues, lymph or bloodstream. In the present study, we have analysed the correlation between in vitro invasion and presence of the epidermal growth factor receptor (EGFR) in a panel of 21 small-cell lung cancer (SCLC) cell lines. We have previously reported that ten of these cell lines expressed EGFR protein detected by radioreceptor and affinity labelling assays. In 11 small-cell lung cancer (SCLC) cell lines, EGFR mRNA was detected by Northern blot analysis. In vitro invasion in a Boyden chamber assay was found in all EGFR-positive cell lines, whereas no invasion was detected in the EGFR-negative cell lines. Quantification of the in vitro invasion in 12 selected SCLC cell lines demonstrated that, in the EGFR-positive cell lines, between 5% and 16% of the cells added to the upper chamber were able to traverse the Matrigel membrane. Expression of several matrix metalloproteases (MMP), of tissue inhibitor of MMP (TIMP) and of cathepsin B was evaluated by immunoprecipitation, Western blot analysis and reverse transcriptase polymerase chain reaction (RT-PCR). However, in vitro invasive SCLC cell lines could not be distinguished from non-invasive cell lines based on the expression pattern of these molecules. In six SCLC cell lines, in vitro invasion was also determined in the presence of the EGFR-neutralizing monoclonal antibody mAb528. The addition of this antibody resulted in a significant reduction of the in vitro invasion in three selected EGFR-positive cell lines. Our results show that only EGFR-positive SCLC cell lines had the in vitro invasive phenotype, and it is therefore suggested that the EGFR might play an important role for the invasion potential of SCLC cell lines. Images Figure 1 Figure 3 Figure 4 PMID:9744504

  20. Immune-Modulation by Epidermal Growth Factor Receptor Inhibitors: Implication on Anti-Tumor Immunity in Lung Cancer

    PubMed Central

    Herrmann, Amanda C.; Bernatchez, Chantale; Haymaker, Cara; Molldrem, Jeffrey J.; Hong, Waun Ki; Perez-Soler, Roman

    2016-01-01

    Skin toxicity is the most common toxicity caused by Epidermal Growth Factor Receptor (EGFR) inhibitors, and has been associated with clinical efficacy. As EGFR inhibitors enhance the expression of antigen presenting molecules in affected skin keratinocytes, they may concurrently facilitate neo-antigen presentation in lung cancer tumor cells contributing to anti-tumor immunity. Here, we investigated the modulatory effect of the EGFR inhibitor, erlotinib on antigen presenting molecules and PD-L1, prominent immune checkpoint protein, of skin keratinocytes and lung cancer cell lines to delineate the link between EGFR signaling pathway inhibition and potential anti-tumor immunity. Erlotinib up-regulated MHC-I and MHC-II proteins on IFNγ treated keratinocytes but abrogated IFNγ-induced expression of PD-L1, suggesting the potential role of infiltrating autoreactive T cells in the damage of keratinocytes in affected skin. Interestingly, the surface expression of MHC-I, MHC-II, and PD-L1 was up-regulated in response to IFNγ more often in lung cancer cell lines sensitive to erlotinib, but only expression of PD-L1 was inhibited by erlotinib. Further, erlotinib significantly increased T cell mediated cytotoxicity on lung cancer cells. Lastly, the analysis of gene expression dataset of 186 lung cancer cell lines from Cancer Cell Line Encyclopedia demonstrated that overexpression of PD-L1 was associated with sensitivity to erlotinib and higher expression of genes related to antigen presenting pathways and IFNγ signaling pathway. Our findings suggest that the EGFR inhibitors can facilitate anti-tumor adaptive immune responses by breaking tolerance especially in EGFR driven lung cancer that are associated with overexpression of PD-L1 and genes related to antigen presentation and inflammation. PMID:27467256

  1. Cost-Effectiveness of Pertuzumab in Human Epidermal Growth Factor Receptor 2–Positive Metastatic Breast Cancer

    PubMed Central

    Qian, Yushen; Pollom, Erqi L.; King, Martin T.; Dudley, Sara A.; Shaffer, Jenny L.; Chang, Daniel T.; Gibbs, Iris C.; Goldhaber-Fiebert, Jeremy D.; Horst, Kathleen C.

    2016-01-01

    Purpose The Clinical Evaluation of Pertuzumab and Trastuzumab (CLEOPATRA) study showed a 15.7-month survival benefit with the addition of pertuzumab to docetaxel and trastuzumab (THP) as first-line treatment for patients with human epidermal growth factor receptor 2 (HER2) –overexpressing metastatic breast cancer. We performed a cost-effectiveness analysis to assess the value of adding pertuzumab. Patient and Methods We developed a decision-analytic Markov model to evaluate the cost effectiveness of docetaxel plus trastuzumab (TH) with or without pertuzumab in US patients with metastatic breast cancer. The model followed patients weekly over their remaining lifetimes. Health states included stable disease, progressing disease, hospice, and death. Transition probabilities were based on the CLEOPATRA study. Costs reflected the 2014 Medicare rates. Health state utilities were the same as those used in other recent cost-effectiveness studies of trastuzumab and pertuzumab. Outcomes included health benefits expressed as discounted quality-adjusted life-years (QALYs), costs in US dollars, and cost effectiveness expressed as an incremental cost-effectiveness ratio. One- and multiway deterministic and probabilistic sensitivity analyses explored the effects of specific assumptions. Results Modeled median survival was 39.4 months for TH and 56.9 months for THP. The addition of pertuzumab resulted in an additional 1.81 life-years gained, or 0.62 QALYs, at a cost of $472,668 per QALY gained. Deterministic sensitivity analysis showed that THP is unlikely to be cost effective even under the most favorable assumptions, and probabilistic sensitivity analysis predicted 0% chance of cost effectiveness at a willingness to pay of $100,000 per QALY gained. Conclusion THP in patients with metastatic HER2-positive breast cancer is unlikely to be cost effective in the United States. PMID:26351332

  2. Immune-Modulation by Epidermal Growth Factor Receptor Inhibitors: Implication on Anti-Tumor Immunity in Lung Cancer.

    PubMed

    Im, Jin S; Herrmann, Amanda C; Bernatchez, Chantale; Haymaker, Cara; Molldrem, Jeffrey J; Hong, Waun Ki; Perez-Soler, Roman

    2016-01-01

    Skin toxicity is the most common toxicity caused by Epidermal Growth Factor Receptor (EGFR) inhibitors, and has been associated with clinical efficacy. As EGFR inhibitors enhance the expression of antigen presenting molecules in affected skin keratinocytes, they may concurrently facilitate neo-antigen presentation in lung cancer tumor cells contributing to anti-tumor immunity. Here, we investigated the modulatory effect of the EGFR inhibitor, erlotinib on antigen presenting molecules and PD-L1, prominent immune checkpoint protein, of skin keratinocytes and lung cancer cell lines to delineate the link between EGFR signaling pathway inhibition and potential anti-tumor immunity. Erlotinib up-regulated MHC-I and MHC-II proteins on IFNγ treated keratinocytes but abrogated IFNγ-induced expression of PD-L1, suggesting the potential role of infiltrating autoreactive T cells in the damage of keratinocytes in affected skin. Interestingly, the surface expression of MHC-I, MHC-II, and PD-L1 was up-regulated in response to IFNγ more often in lung cancer cell lines sensitive to erlotinib, but only expression of PD-L1 was inhibited by erlotinib. Further, erlotinib significantly increased T cell mediated cytotoxicity on lung cancer cells. Lastly, the analysis of gene expression dataset of 186 lung cancer cell lines from Cancer Cell Line Encyclopedia demonstrated that overexpression of PD-L1 was associated with sensitivity to erlotinib and higher expression of genes related to antigen presenting pathways and IFNγ signaling pathway. Our findings suggest that the EGFR inhibitors can facilitate anti-tumor adaptive immune responses by breaking tolerance especially in EGFR driven lung cancer that are associated with overexpression of PD-L1 and genes related to antigen presentation and inflammation. PMID:27467256

  3. Radiosensitivity enhancement of radioresistant glioblastoma by epidermal growth factor receptor antibody-conjugated iron-oxide nanoparticles

    PubMed Central

    Bouras, Alexandros; Kaluzova, Milota; Hadjipanayis, Costas G.

    2015-01-01

    The epidermal growth factor receptor deletion variant EGFRvIII is known to be expressed in a subset of patients with glioblastoma (GBM) tumors that enhances tumorigenicity and also accounts for radiation and chemotherapy resistance. Targeting the EGFRvIII deletion mutant may lead to improved GBM therapy and better patient prognosis. Multifunctional magnetic nanoparticles serve as a potential clinical tool that can provide cancer cell targeted drug delivery, imaging, and therapy. Our previous studies have shown that an EGFRvIII-specific antibody and cetuximab (an EGFR- and EGFRvIII-specific antibody), when bioconjugated to IONPs (EGFRvIII-IONPs or cetuximab-IONPs respectively), can simultaneously provide sensitive cancer cell detection by magnetic resonance imaging (MRI) and targeted therapy of experimental GBM. In this study, we investigated whether cetuximab-IONPs can additionally allow for the radiosensitivity enhancement of GBM. Cetuximab-IONPs were used in combination with single (10Gy x 1) or multiple fractions (10Gy x 2) of ionizing radiation (IR) for radiosensitization of EGFRvIII-overexpressing human GBM cells in vitro and in vivo after convection-enhanced delivery (CED). A significant GBM antitumor effect was observed in vitro after treatment with cetuximab-IONPs and subsequent single or fractionated IR. A significant increase in overall survival of nude mice implanted with human GBM xenografts was found after treatment by cetuximab-IONP CED and subsequent fractionated IR. Increased DNA double strands breaks (DSBs), as well as increased reactive oxygen species (ROS) formation, were felt to represent the mediators of the observed radiosensitization effect with the combination therapy of IR and cetuximab-IONPs treatment. PMID:25981803

  4. Analysis of p53 mutation and epidermal growth factor receptor amplification in recurrent gliomas with malignant progression

    SciTech Connect

    Reifenberger, J.; Ring, G.U.; Gies, U.

    1996-07-01

    Genomic alterations and expression of the p53 tumor suppressor gene and the epidermal growth factor receptor gene (EGFR) were investigated in 22 patients with primary World Health Organization (WHO) grade II gliomas that on recurrence had progressed to malignant gliomas of WHO grades III or IV. Mutations of the p53 gene (exons 5 to 8) were found in 12 of 22 primary tumors (10 of 13 astrocytomas, 1 of 7 oligodendrogliomas, 1 of 2 oligoastrocytomas). In each of these cases identical p53 mutations were present in the respective malignant recurrences. In all instances in which the p53 mutation was associated with p53 protein accumulation (10 of 12 cases), the percentage of p53 immunopositive tumor cells had increased from the primary to the recurrent tumor. None of the primary low-grade and none of the recurrent high-grade tumors (7 anaplastic astrocytomas, 10 anaplastic oligodendrogliomas, 4 anaplastic oligoastrocytomas, and 5 glioblastomas) showed evidence of EGFR gene amplification. Our results thus demonstrate that p53 is mutated in a high fraction of low-grade astrocytomas with progression to anaplastic astrocytomas and glioblastomas and that progression in such cases is frequently associated with an increase in the fraction of p53 immunopositive tumor cells. The general absence of EGFR amplification in our tumor series supports the hypothesis that the significance of p53 mutation and EGFR amplification may be different in glioblastomas that developed by progression from low-grade astrocytomas (secondary glioblastomas) compared to glioblastomas that developed rapidly in a de novo manner without a history of previous low-grade tumor (primary glioblastomas). 54 refs., 3 figs., 1 tab.

  5. Intercalated chemotherapy and erlotinib for non-small cell lung cancer (NSCLC) with activating epidermal growth factor receptor (EGFR) mutations

    PubMed Central

    Zwitter, Matjaz; Rajer, Mirjana; Stanic, Karmen; Vrankar, Martina; Doma, Andrej; Cuderman, Anka; Grmek, Marko; Kern, Izidor; Kovac, Viljem

    2016-01-01

    ABSTRACT Among attempts to delay development of resistance to tyrosine kinase inhibitors (TKIs) in patients with advanced non-small cell lung cancer (NSCLC) with activating mutations of epidermal growth factor receptor (EGFR), intercalated therapy has not been properly evaluated. In a phase II trial, 38 patients with EGFR mutated NSCLC in advanced stage were treated with 4 to 6 3-weekly cycles of intercalated schedule with gemcitabine (1250 mg/m2, days 1 and 4), cisplatin (75 mg/m2, day 2) and erlotinib (150 mg, days 5 – 15), followed by continuous erlotinib as maintenance. In addition to standard radiologic evaluation according to RECIST, PET/CT was done prior to treatment and at 6 months, using PERCIST as a method for assessment of response. The primary endpoint was progression-free survival (PFS). In general, tolerance to treatment was good, even among 8 patients with performance status 2–3 and 13 patients with brain metastases; grade 4 toxicity included 2 cases of neutropenia and 4 thrombo-embolic events. Complete response (CR) or partial response (PR) were seen in 15 (39.5%) and 17 (44.7%) cases, respectively. All cases of CR were confirmed also by PET/CT. Median PFS was 23.4 months and median overall survival (OS) was 38.3  months. After a median follow-up of 35 months, 8 patients are still in CR and on maintenance erlotinib. In conclusion, intercalated treatment for treatment-naive patients with EGFR activating mutations leads to excellent response rate and prolonged PFS and survival. Comparison of the intercalated schedule to monotherapy with TKIs in a randomized trial is warranted. PMID:27261103

  6. ImmunoPET and biodistribution with human epidermal growth factor receptor 3 targeting antibody 89Zr-RG7116

    PubMed Central

    Terwisscha van Scheltinga, Anton GT; Lub-de Hooge, Marjolijn N; Abiraj, Keelara; Schröder, Carolien P; Pot, Linda; Bossenmaier, Birgit; Thomas, Marlene; Hölzlwimmer, Gabriele; Friess, Thomas; Kosterink, Jos GW; de Vries, Elisabeth GE

    2014-01-01

    The humanized monoclonal antibody with high affinity for the human epidermal growth factor receptor (HER) 3, RG7116, is a glycoengineered, IgG1 class antibody. By labeling RG7116 with zirconium-89 (89Zr) we aimed to visualize in vivo HER3 expression and study the biodistribution of this antibody in human tumor-bearing mice. Biodistribution of 89Zr-RG7116 was studied in subcutaneously xenografted FaDu tumor cells (HER3-positive). Dose-dependency of 89Zr-RG7116 organ distribution and specific tumor uptake was assessed by administering doses ranging from 0.05 to 10 mg/kg RG7116 to SCID/Beige mice. Biodistribution was analyzed at 24 and 144 h after injection. MicroPET imaging was performed at 1, 3, and 6 days after injection of 1.0 mg/kg 89Zr-RG7116 in the FaDu, H441, QG-56 and Calu-1 xenografts with varying HER3 expression. The excised tumors were analyzed for HER3 expression. Biodistribution analyses showed a dose- and time-dependent 89Zr-RG7116 tumor uptake in FaDu tumors. The highest tumor uptake of 89Zr-RG7116 was observed in the 0.05 mg/kg dose group with 27.5%ID/g at 144 h after tracer injection. MicroPET imaging revealed specific tumor uptake of 89Zr-RG7116 in FaDu and H441 models with an increase in tumor uptake over time. Biodistribution data was consistent with the microPET findings in FaDu, H441, QG56 and Calu-1 xenografts, which correlated with HER3 expression levels. In conclusion, 89Zr-RG7116 specifically accumulates in HER3 expressing tumors. PET imaging with this tracer provides real-time non-invasive information about RG7116 distribution, tumor targeting and tumor HER3 expression levels. PMID:24870719

  7. Prognostic Impact of Epidermal Growth Factor Receptor Overexpression in Patients with Cervical Cancer: A Meta-Analysis.

    PubMed

    Tian, Wei-Jie; Huang, Miao-Ling; Qin, Qing-Feng; Chen, Qing; Fang, Kun; Wang, Ping-Ling

    2016-01-01

    Clinical trials have provided conflicting results regarding whether epidermal growth factor receptor (EGFR) overexpression predicts poor survival in cervical cancer patients. In this study, we perform a meta-analysis of the association between EGFR expression and survival in cervical cancer patients. We searched clinical studies in the Medline, PubMed, Embase, and Web of Science databases. A total of 22 studies with 2,505 patients were included, and pooled hazard ratios (HRs) with 95% confidence intervals (CIs) were calculated for each study. Heterogeneity was assessed using Higgins I2 to select a Mantel-Haenszel fixed effects model (I2 ≤50%) or a DerSimonian-Laird random effects model (I2 ≥50%). High EGFR levels predicted poor overall survival (OS) (HR: 1.40, 95% CI: 1.10-1.78) and disease-free survival (DFS) (HR: 1.84, 95% CI: 1.51-2.24). Stratified analyses showed that EGFR overexpression was significantly related to poor DFS in patients treated with chemoradiation or surgery. Moreover, the pooled odds ratios (ORs) revealed associations between EGFR expression and clinicopathological features, such as lymph node metastasis (OR: 1.72, 95% CI: 1.23-2.40) and tumor size ≥4 cm (OR: 1.64, 95% CI: 1.20-2.23). This meta-analysis demonstrates that EGFR overexpression is closely associated with reduced survival in patients with cervical cancer. These results may facilitate the individualized management of clinical decisions for anti-EGFR therapies in cervical cancer patients. PMID:27438047

  8. A sensitive and practical method to detect the T790M mutation in the epidermal growth factor receptor

    PubMed Central

    ZHAO, JING; FENG, HUA-HUA; ZHAO, JIN-YIN; LIU, LI-CHENG; XIE, FEI-FEI; XU, YAN; CHEN, MIN-JIANG; ZHONG, WEI; LI, LONG-YUN; WANG, HAN-PING; ZHANG, LI; XIAO, YI; CHEN, WEI-JUN; WANG, MENG-ZHAO

    2016-01-01

    The current study aimed to develop a method to rapidly, sensitively and practically screen for the epidermal growth factor receptor (EGFR) T790M mutation. This method combines an allele-specific competitive blocker (ACB) with a TaqMan quantitative polymerase chain reaction (PCR) amplification refractory mutation system (ARMS) in a one-step reaction. Using a mimic of a human genomic DNA panel containing serially diluted mutant alleles, the performance efficacy of this method was assessed. Using this method, the EGFR T790M mutation was detected in tyrosine kinase inhibitor (TKI)-naïve samples obtained from 27 non-small cell lung cancer (NSCLC) patients with EGFR-activating mutations. The association between de novo T790M mutations and the clinical benefit of EGFR-TKI treatment was also analysed. The sensitivity of this method was as low as 0.01%. In the samples from the 27 NSCLC patients, this method identified 6 mutant patients (22.2%), which was higher than the detection rate with scorpion ARMS (0.0%). No clinical variables were associated with the occurrence of a de novo T790M mutation. The median progression-free survival time in the TKI-naïve patients with a T790M mutation was shorter that that of patients without the mutation, but the difference was not significant (3.2 vs. 19.5 months, respectively; P=0.256). The median overall survival time in the groups with or without T790M mutation also did not significantly differ (10 vs. 20 months, respectively; P=0.689). Overall, the ACB-ARMS PCR method could be useful for detecting the EGFR T790M mutation in clinical samples that contain only a small number of mutant alleles. The clinical significance of a de novo T790M mutation should be further investigated. PMID:27073519

  9. Intraoperative fluorescence delineation of head and neck cancer with a fluorescent anti-epidermal growth factor receptor nanobody.

    PubMed

    van Driel, P B A A; van der Vorst, J R; Verbeek, F P R; Oliveira, S; Snoeks, T J A; Keereweer, S; Chan, B; Boonstra, M C; Frangioni, J V; van Bergen en Henegouwen, P M P; Vahrmeijer, A L; Lowik, C W G M

    2014-06-01

    Intraoperative near-infrared (NIR) fluorescence imaging is a technology with high potential to provide the surgeon with real-time visualization of tumors during surgery. Our study explores the feasibility for clinical translation of an epidermal growth factor receptor (EGFR)-targeting nanobody for intraoperative imaging and resection of orthotopic tongue tumors and cervical lymph node metastases. The anti-EGFR nanobody 7D12 and the negative control nanobody R2 were conjugated to the NIR fluorophore IRDye800CW (7D12-800CW and R2-800CW). Orthotopic tongue tumors were induced in nude mice using the OSC-19-luc2-cGFP cell line. Tumor-bearing mice were injected with 25 µg 7D12-800CW, R2-800CW or 11 µg 800CW. Subsequently, other mice were injected with 50 or 75 µg of 7D12-800CW. The FLARE imaging system and the IVIS spectrum were used to identify, delineate and resect the primary tumor and cervical lymph node metastases. All tumors could be clearly identified using 7D12-800CW. A significantly higher tumor-to-background ratio (TBR) was observed in mice injected with 7D12-800CW compared to mice injected with R2-800CW and 800CW. The highest average TBR (2.00 ± 0.34 and 2.72 ± 0.17 for FLARE and IVIS spectrum, respectively) was observed 24 hr after administration of the EGFR-specific nanobody. After injection of 75 µg 7D12-800CW cervical lymph node metastases could be clearly detected. Orthotopic tongue tumors and cervical lymph node metastases in a mouse model were clearly identified intraoperatively using a recently developed fluorescent EGFR-targeting nanobody. Translation of this approach to the clinic would potentially improve the rate of radical surgical resections.

  10. 18F-FDG PET/CT for Monitoring Treatment Responses to the Epidermal Growth Factor Receptor Inhibitor Erlotinib

    PubMed Central

    Walter, Franziska; Garon, Edward B.; Reckamp, Karen L.; Figlin, Robert; Phelps, Michael E.; Weber, Wolfgang A.; Czernin, Johannes; Allen-Auerbach, Martin S.

    2016-01-01

    Response rates of unselected non–small cell lung cancer (NSCLC) patients to the epidermal growth factor receptor inhibitor erlotinib are low and range from 10% to 20%. Early response assessments are needed to avoid costs and side effects of inefficient treatments. Here we determined whether early changes in tumor uptake of 18F-FDG can predict progression-free and overall survival in NSCLC patients who are treated with erlotinib. Methods Twenty-two patients (6 men, 16 women; mean age ± SD, 64 ± 13 y) with stage III or stage IV NSCLC who received erlotinib treatment were enrolled prospectively. 18F-FDG PET/CT was performed before the initiation of treatment (n = 22), after 2 wk (n = 22), and after 78 ± 21 d (n = 11). Tumor maximum standardized uptake values were measured for a maximum of 5 lesions for each patient. Tumor responses were classified using modified PET Response Criteria in Solid Tumors (use of maximum standardized uptake values). Median overall survival by Kaplan–Meier analysis was compared between groups using a log-rank test. Results The overall median time to progression was 52 d (95% confidence interval, 47–57 d). The overall median survival time was 131 d (95% confidence interval, 0–351 d). Patients with progressive metabolic disease on early follow-up PET showed a significantly shorter time to progression (47 vs. 119 d; P < 0.001) and overall survival (87 vs. 828 d; P = 0.01) than patients classified as having stable metabolic disease or partial or complete metabolic response. Conclusion These data suggest that 18F-FDG PET/CT performed early after the start of erlotinib treatment can help to identify patients who benefit from this targeted therapy. PMID:22045706

  11. Ado-Trastuzumab Emtansine Targets Hepatocytes Via Human Epidermal Growth Factor Receptor 2 to Induce Hepatotoxicity.

    PubMed

    Yan, Haoheng; Endo, Yukinori; Shen, Yi; Rotstein, David; Dokmanovic, Milos; Mohan, Nishant; Mukhopadhyay, Partha; Gao, Bin; Pacher, Pal; Wu, Wen Jin

    2016-03-01

    Ado-trastuzumab emtansine (T-DM1) is an antibody-drug conjugate (ADC) approved for the treatment of HER2-positive metastatic breast cancer. It consists of trastuzumab, a humanized mAb directed against HER2, and a microtubule inhibitor, DM1, conjugated to trastuzumab via a thioether linker. Hepatotoxicity is one of the serious adverse events associated with T-DM1 therapy. Mechanisms underlying T-DM1-induced hepatotoxicity remain elusive. Here, we use hepatocytes and mouse models to investigate the mechanisms of T-DM1-induced hepatotoxicity. We show that T-DM1 is internalized upon binding to cell surface HER2 and is colocalized with LAMP1, resulting in DM1-associated cytotoxicity, including disorganized microtubules, nuclear fragmentation/multiple nuclei, and cell growth inhibition. We further demonstrate that T-DM1 treatment significantly increases the serum levels of aspartate aminotransferase, alanine aminotransferase, and lactate dehydrogenase in mice and induces inflammation and necrosis in liver tissues, and that T-DM1-induced hepatotoxicity is dose dependent. Moreover, the gene expression of TNFα in liver tissues is significantly increased in mice treated with T-DM1 as compared with those treated with trastuzumab or vehicle. We propose that T-DM1-induced upregulation of TNFα enhances the liver injury that may be initially caused by DM1-mediated intracellular damage. Our proposal is underscored by the fact that T-DM1 induces the outer mitochondrial membrane rupture, a typical morphologic change in the mitochondrial-dependent apoptosis, and mitochondrial membrane potential dysfunction. Our work provides mechanistic insights into T-DM1-induced hepatotoxicity, which may yield novel strategies to manage liver injury induced by T-DM1 or other ADCs. PMID:26712117

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

    PubMed

    Chung, Clement

    2016-06-01

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

  13. PTEN mutation and epidermal growth factor receptor activation regulate vascular endothelial growth factor (VEGF) mRNA expression in human glioblastoma cells by transactivating the proximal VEGF promoter.

    PubMed

    Pore, Nabendu; Liu, Shuang; Haas-Kogan, Daphne A; O'Rourke, Donald M; Maity, Amit

    2003-01-01

    Our previous work showed that, compared with parental U87MG human glioblastoma cells, vascular endothelial growth factor (VEGF) mRNA levels are decreased in U87/T691, a derivative line in which epidermal growth factor receptor (EGFR) signaling is inhibited by introduction of a truncated p185(Neu) protein (A. Maity et al., Cancer Res., 60: 5879-5886, 2000). The effect of EGFR activation on VEGF was mediated at the level of transcription via a phosphatidylinositol 3'-kinase (PI3K)-dependent pathway. In the current study we investigated the effect of PTEN, a negative regulator of PI3K signaling commonly mutated in glioblastoma cells, on VEGF expression. Several glioblastoma cell lines containing mutant PTEN, including U87MG, U87/T691, and U251MG, were infected with adenovirus expressing wild-type PTEN. This led to a decrease in the levels of both VEGF mRNA and phosphorylated Akt, a marker for PI3K activation. Treatment of U87MG cells with LY294002, a PI3K inhibitor, or cotransfection with a vector expressing wild-type PTEN decreased VEGF promoter activity using reporters containing either 1.5 kb of the promoter or a fragment extending from -88 to +54 bp. Activity of the -88/+54 VEGF promoter was down-regulated by dominant negative Akt and up-regulated by constitutively active myristoylated Akt. Introduction of wild-type PTEN and pharmacological inhibition of EGFR decreased VEGF mRNA expression and VEGF promoter activity in U87MG cells to a greater extent that did either manipulation by itself. Therefore, in human glioblastoma cells, PTEN mutation can cooperate with EGFR activation to increase VEGF mRNA levels by transcriptionally up-regulating the proximal VEGF promoter via the PI3K/Akt pathway.

  14. From bench to bedside: what do we know about Hormone Receptor-positive and Human Epidermal Growth Factor Receptor 2-positive breast cancer?

    PubMed Central

    Wu, Victoria Shang; Kanaya, Noriko; Lo, Chiao; Mortimer, Joanne; Chen, Shiuan

    2015-01-01

    Breast cancer is a heterogeneous disease. Thanks to extensive efforts from research scientists and clinicians, treatment for breast cancer has advanced into the era of targeted medicine. With the use of several well-established biomarkers, such as hormone receptors (HRs) (i.e. estrogen receptor [ER] and progesterone receptor [PgR]) and Human Epidermal Growth Factor Receptor-2 (HER2), breast cancer patients can be categorized into multiple subgroups with specific targeted treatment strategies. Although therapeutic strategies for HR-positive (HR+) HER2-negative (HER2−) breast cancer and HR-negative (HR−) HER2-positive (HER2+) breast cancer are well-defined, HR+ HER2+ breast cancer is still an overlooked subgroup without tailored therapeutic options. In this review, we have summarized the molecular characteristics, etiology, preclinical tools and therapeutic options for HR+ HER2+ breast cancer. We hope to raise the attention of both the research and the medical community on HR+ HER2+ breast cancer, and to advance patient care for this subtype of disease. PMID:25998416

  15. Epidermal Growth Factor Receptor Transactivation Is Required for Mitogen-Activated Protein Kinase Activation by Muscarinic Acetylcholine Receptors in HaCaT Keratinocytes

    PubMed Central

    Ockenga, Wymke; Kühne, Sina; Bocksberger, Simone; Banning, Antje; Tikkanen, Ritva

    2014-01-01

    Non-neuronal acetylcholine plays a substantial role in the human skin by influencing adhesion, migration, proliferation and differentiation of keratinocytes. These processes are regulated by the Mitogen-Activated Protein (MAP) kinase cascade. Here we show that in HaCaT keratinocytes all five muscarinic receptor subtypes are expressed, but M1 and M3 are the subtypes involved in mitogenic signaling. Stimulation with the cholinergic agonist carbachol leads to activation of the MAP kinase extracellular signal regulated kinase, together with the protein kinase Akt. The activation is fully dependent on the transactivation of the epidermal growth factor receptor (EGFR), which even appears to be the sole pathway for the muscarinic receptors to facilitate MAP kinase activation in HaCaT cells. The transactivation pathway involves a triple-membrane-passing process, based on activation of matrix metalloproteases, and extracellular ligand release; whereas phosphatidylinositol 3-kinase, Src family kinases or protein kinase C do not appear to be involved in MAP kinase activation. Furthermore, phosphorylation, ubiquitination and endocytosis of the EGF receptor after cholinergic transactivation are different from that induced by a direct stimulation with EGF, suggesting that ligands other than EGF itself mediate the cholinergic transactivation. PMID:25421240

  16. From bench to bedside: What do we know about hormone receptor-positive and human epidermal growth factor receptor 2-positive breast cancer?

    PubMed

    Wu, Victoria Shang; Kanaya, Noriko; Lo, Chiao; Mortimer, Joanne; Chen, Shiuan

    2015-09-01

    Breast cancer is a heterogeneous disease. Thanks to extensive efforts from research scientists and clinicians, treatment for breast cancer has advanced into the era of targeted medicine. With the use of several well-established biomarkers, such as hormone receptors (HRs) (i.e., estrogen receptor [ER] and progesterone receptor [PgR]) and human epidermal growth factor receptor-2 (HER2), breast cancer patients can be categorized into multiple subgroups with specific targeted treatment strategies. Although therapeutic strategies for HR-positive (HR+) HER2-negative (HER2-) breast cancer and HR-negative (HR-) HER2-positive (HER2+) breast cancer are well-defined, HR+ HER2+ breast cancer is still an overlooked subgroup without tailored therapeutic options. In this review, we have summarized the molecular characteristics, etiology, preclinical tools and therapeutic options for HR+ HER2+ breast cancer. We hope to raise the attention of both the research and the medical community on HR+ HER2+ breast cancer, and to advance patient care for this subtype of disease.

  17. Photodynamic treatment of epithelial tissue derived from patients with endometrial cancer: a contribution to the role of laminin and epidermal growth factor receptor in photodynamic therapy

    NASA Astrophysics Data System (ADS)

    Ziolkowski, Piotr P.; Symonowicz, Krzysztof; Osiecka, Beata J.; Rabczynski, Jerzy; Gerber, Jerzy

    1999-07-01

    Photodynamic therapy (PDT) was used to treat endometrial G1 cancer tissue derived from patients who had undergone a total hysterectomy and bilateral salpingo-oophorectomy. After surgical treatment the cancerous tissue was kept in a medium containing Dulbecco solution, fetal calf serum, and antibiotics. The tissue was then exposed to hematoporphyrin derivative (0.1 mg/l) and 24 h later exposed to light (total light dose--18 J/sq cm). Necrosis depth was evaluated 24 h later using a light microscope. In order to assess the possible role of the basal membrane component laminin, as well as epidermal growth factor receptor susceptibility to PDT, immunohistochemical studies were carried out. Additionally, nucleolar organizer regions evaluation was performed. Our experiment confirmed that PDT results in the necrosis in the treated endometrial cancer, while not affecting the laminin in the cancerous tissue. In contrast, PDT strongly affects the epidermal growth factor receptor and nucleolar organizer regions in cancer cells. We suggest that laminin may contribute to the prevention of cancer dissemination in the cases where PDT has to be repeated, and that after PDT the cells become less susceptible to a mitogen, like, e.g., epidermal growth factor.

  18. Serum IgE, tumor epidermal growth factor receptor expression, and inherited polymorphisms associated with glioma survival.

    PubMed

    Wrensch, Margaret; Wiencke, John K; Wiemels, Joe; Miike, Rei; Patoka, Joe; Moghadassi, Michelle; McMillan, Alex; Kelsey, Karl T; Aldape, Kenneth; Lamborn, Kathleen R; Parsa, Andrew T; Sison, Jennette D; Prados, Michael D

    2006-04-15

    In population-based glioma patients, we examined survival in relation to potentially pertinent constitutive polymorphisms, serologic factors, and tumor genetic and protein alterations in epidermal growth factor receptor (EGFR), MDM2, and TP53. Subjects were newly diagnosed adults residing in the San Francisco Bay Surveillance Epidemiology and End Results Area during 1991 to 1994 and 1997 to 1999 with central neuropathology review (n = 873). Subjects provided blood for serologic studies of IgE and IgG to four herpes viruses and constitutive specimens for genotyping 22 polymorphisms in 13 genes (n = 471). We obtained 595 of 697 astrocytic tumors for marker studies. We determined treatments, vital status, and other factors using registry, interview, medical record, and active follow-up data. Cox regressions for survival were adjusted for age, gender, ethnicity, study series, resection versus biopsy only, radiation, and chemotherapy. Using a stringent P < 0.001, glioma survival was associated with ERCC1 C8092A [hazard ratio (HR), 0.72; 95% confidence limits (95% CL), 0.60-0.86; P = 0.0004] and GSTT1 deletion (HR, 1.64; 95% CL, 1.25-2.16; P = 0.0004); glioblastoma patients with elevated IgE had 9 months longer survival than those with normal or borderline IgE levels (HR, 0.62; 95% CL, 0.47-0.82; P = 0.0007), and EGFR expression in anaplastic astrocytoma was associated with nearly 3-fold poorer survival (HR, 2.97; 95% CL, 1.70-5.19; P = 0.0001). Based on our and others' findings, we recommend further studies to (a) understand relationships of elevated IgE levels and other immunologic factors with improved glioblastoma survival potentially relevant to immunologic therapies and (b) determine which inherited ERCC1 variants or other variants in the 19q13.3 region influence survival. We also suggest that tumor EGFR expression be incorporated into clinical evaluation of anaplastic astrocytoma patients.

  19. Investigation of the Dimerization of Proteins from the Epidermal Growth Factor Receptor Family by Single Wavelength Fluorescence Cross-Correlation Spectroscopy

    PubMed Central

    Liu, Ping; Sudhaharan, Thankiah; Koh, Rosita M. L.; Hwang, Ling C.; Ahmed, Sohail; Maruyama, Ichiro N.; Wohland, Thorsten

    2007-01-01

    Single wavelength fluorescence cross-correlation spectroscopy (SW-FCCS), introduced to study biomolecular interactions, has recently been reported to monitor enzyme activity by using a newly developed fluorescent protein variant together with cyan fluorescent protein. Here, for the first time to our knowledge, SW-FCCS is applied to detect interactions between membrane receptors in vivo by using the widely used enhanced green fluorescent protein and monomeric red fluorescent protein. The biological system studied here is the epidermal growth factor/ErbB receptor family, which plays pivotal roles in the development of organisms ranging from worms to humans. It is widely thought that a ligand binds to the monomeric form of the receptor and induces its dimeric form for activation. By using SW-FCCS and Förster resonance energy transfer, we show that the epidermal growth factor receptor and ErbB2 have preformed homo- and heterodimeric structures on the cell surface and quantitation of dimer fractions is performed by SW-FCCS. These receptors are major targets of anti-cancer drug development, and the receptors' homo- and heterodimeric structures are relevant for such developments. PMID:17468161

  20. Bystander killing effect of DS-8201a, a novel anti-human epidermal growth factor receptor 2 antibody-drug conjugate, in tumors with human epidermal growth factor receptor 2 heterogeneity.

    PubMed

    Ogitani, Yusuke; Hagihara, Katsunobu; Oitate, Masataka; Naito, Hiroyuki; Agatsuma, Toshinori

    2016-07-01

    Antibody-drug conjugates deliver anticancer agents selectively and efficiently to tumor tissue and have significant antitumor efficacy with a wide therapeutic window. DS-8201a is a human epidermal growth factor receptor 2 (HER2)-targeting antibody-drug conjugate prepared using a novel linker-payload system with a potent topoisomerase I inhibitor, exatecan derivative (DX-8951 derivative, DXd). It was effective against trastuzumab emtansine (T-DM1)-insensitive patient-derived xenograft models with both high and low HER2 expression. In this study, the bystander killing effect of DS-8201a was evaluated and compared with that of T-DM1. We confirmed that the payload of DS-8201a, DXd (1), was highly membrane-permeable whereas that of T-DM1, Lys-SMCC-DM1, had a low level of permeability. Under a coculture condition of HER2-positive KPL-4 cells and negative MDA-MB-468 cells in vitro, DS-8201a killed both cells, whereas T-DM1 and an antibody-drug conjugate with a low permeable payload, anti-HER2-DXd (2), did not. In vivo evaluation was carried out using mice inoculated with a mixture of HER2-positive NCI-N87 cells and HER2-negative MDA-MB-468-Luc cells by using an in vivo imaging system. In vivo, DS-8201a reduced the luciferase signal of the mice, indicating suppression of the MDA-MB-468-Luc population; however, T-DM1 and anti-HER2-DXd (2) did not. Furthermore, it was confirmed that DS-8201a was not effective against MDA-MB-468-Luc tumors inoculated at the opposite side of the NCI-N87 tumor, suggesting that the bystander killing effect of DS-8201a is observed only in cells neighboring HER2-positive cells, indicating low concern in terms of systemic toxicity. These results indicated that DS-8201a has a potent bystander effect due to a highly membrane-permeable payload and is beneficial in treating tumors with HER2 heterogeneity that are unresponsive to T-DM1. PMID:27166974

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

    SciTech Connect

    Gao, Lin; Chao, Lee; Chao, Julie

    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. Prognostic implications of p53 protein, epidermal growth factor receptor, and Ki-67 labelling in brain tumours.

    PubMed Central

    Jaros, E.; Perry, R. H.; Adam, L.; Kelly, P. J.; Crawford, P. J.; Kalbag, R. M.; Mendelow, A. D.; Sengupta, R. P.; Pearson, A. D.

    1992-01-01

    The expression of p53 protein, epidermal growth factor receptor (EGFR), and Ki-67 nuclear antigen was examined by immunohistochemistry in biopsies of 16 types of human brain tumours, including 43 astrocytomas. P53 protein, almost certainly its mutant form, was expressed in seven of the 16, and EGFR in 11 of the 16 types of tumours. In astrocytomas both the proportion of tumours which expressed p53 or EGFR increased with grade of malignancy as did the mean Ki-67 labelling index (LI): p53-0% in grade 1, 17% in grade 2, 38% in grade 3, 65% in grade 4; EGFR-0% in grade 1, 33% in grade 2, 85% in grade 3, 95% in grade 4; mean Ki-67 L1-1.1% in grades 1 and 2, 8.3% in grade 3, and 13.4% in grade 4. Astrocytomas which expressed p53 or EGFR had a significantly higher Ki-67 LI at P less than 0.05 (11.8% and 10.7%, resp.) than those that did not (6.2% or 4.1%, resp.). Patients with astrocytomas expressing p53 or EGFR had a significantly reduced survival (P = 0.035 and P = 0.007, resp.): only 11% of the p53 + ve and 13% of the EGFR + ve patients were alive at 100 weeks following diagnosis compared to 36% of p53-ve or 60% of EGFR-ve patients. Patients with Ki-67 LI greater than 5% had a reduced survival (P less than 0.0001)--none survived beyond 86 weeks following diagnosis, whilst 63% of patients with less than 5% positive cells were still alive at 100 weeks. The univariate analysis showed that in astrocytomas expression of p53 mutants, EGFR protein, and Ki-67 greater than 5% are associated with malignant progression and poor prognosis. The multivariate analysis revealed that only tumour grade and Ki-67LI were independent prognostic factors for survival. Images Figure 2 Figure 3 Figure 4 Figure 6 Figure 7 Figure 9 PMID:1503912

  3. Oligomerization of epidermal growth factor receptors on A431 cells studied by time-resolved fluorescence imaging microscopy. A stereochemical model for tyrosine kinase receptor activation

    PubMed Central

    1995-01-01

    The aggregation states of the epidermal growth factor receptor (EGFR) on single A431 human epidermoid carcinoma cells were assessed with two new techniques for determining fluorescence resonance energy transfer: donor photobleaching fluorescence resonance energy transfer (pbFRET) microscopy and fluorescence lifetime imaging microscopy (FLIM). Fluorescein-(donor) and rhodamine-(acceptor) labeled EGF were bound to the cells and the extent of oligomerization was monitored by the spatially resolved FRET efficiency as a function of the donor/acceptor ratio and treatment conditions. An average FRET efficiency of 5% was determined after a low temperature (4 degrees C) incubation with the fluorescent EGF analogs for 40 min. A subsequent elevation of the temperature for 5 min caused a substantial increase of the average FRET efficiency to 14% at 20 degrees C and 31% at 37 degrees C. In the context of a two-state (monomer/dimer) model for the EGFR, these FRET efficiencies were consistent with minimal average receptor dimerizations of 13, 36, and 69% at 4, 20, and 37 degrees C, respectively. A431 cells were pretreated with the monoclonal antibody mAb 2E9 that specifically blocks EGF binding to the predominant population of low affinity EGFR (15). The average FRET efficiency increased dramatically to 28% at 4 degrees C, indicative of a minimal receptor dimerization of 65% for the subpopulation of high affinity receptors. These results are in accordance with prior studies indicating that binding of EGF leads to a fast and temperature- dependent microclustering of EGFR, but suggest in addition that the high affinity functional subclass of receptors on quiescent A431 cells are present in a predimerized or oligomerized state. We propose that the transmission of the external ligand-binding signal to the cytoplasmic domain is effected by a concerted relative rotational rearrangement of the monomeric units comprising the dimeric receptor, thereby potentiating a mutual activation of

  4. The DNA replication licensing factor miniature chromosome maintenance 7 is essential for RNA splicing of epidermal growth factor receptor, c-Met, and platelet-derived growth factor receptor.

    PubMed

    Chen, Zhang-Hui; Yu, Yan P; Michalopoulos, George; Nelson, Joel; Luo, Jian-Hua

    2015-01-16

    Miniature chromosome maintenance 7 (MCM7) is an essential component of DNA replication licensing complex. Recent studies indicate that MCM7 is amplified and overexpressed in a variety of human malignancies. In this report, we show that MCM7 binds SF3B3. The binding motif is located in the N terminus (amino acids 221-248) of MCM7. Knockdown of MCM7 or SF3B3 significantly increased unspliced RNA of epidermal growth factor receptor, platelet-derived growth factor receptor, and c-Met. A dramatic drop of reporter gene expression of the oxytocin exon 1-intron-exon 2-EGFP construct was also identified in SF3B3 and MCM7 knockdown PC3 and DU145 cells. The MCM7 or SF3B3 depleted cell extract failed to splice reporter RNA in in vitro RNA splicing analyses. Knockdown of SF3B3 and MCM7 leads to an increase of cell death of both PC3 and DU145 cells. Such cell death induction is partially rescued by expressing spliced c-Met. To our knowledge, this is the first report suggesting that MCM7 is a critical RNA splicing factor, thus giving significant new insight into the oncogenic activity of this protein.

  5. Epidermal growth factor receptor and B7-H3 expression in esophageal squamous tissues correlate to patient prognosis

    PubMed Central

    Song, Jianxiang; Shi, Woda; Zhang, Yajun; Sun, Mingzhong; Liang, Xiaodong; Zheng, Shiying

    2016-01-01

    Biomarkers that can serve as diagnostic and prognostic indicators of esophageal squamous cell carcinoma (ESCC) are urgently needed to help improve patient outcomes. Here, the expression of epidermal growth factor receptor (EGFR) and costimulatory molecule B7-H3, both of which have been implicated in tumor onset and progression in certain tumors, was investigated in relation to the clinical characteristics and survival outcomes of patients with ESCC. ESCC tissue samples were analyzed for 100 patients. Tumor and patient characteristics were recorded. Tissues were investigated for EGFR and B7-H3 staining by immunohistochemistry. Patients were followed for up to 96 months to determine overall survival (OS) and progression-free survival (PFS). High expression for EGFR (68.0%) and B7-H3 (66.0%) was observed in the majority of cases. High expression of either EGFR or B7-H3 was correlated with tumor invasion depth and clinical stage (P<0.05). Further, high expression of either EGFR or B7-H3 was correlated with worse survival outcomes. The estimated OS (38.1 months) and PFS (13.4 months) of patients with high expression of EGFR were lower than those of patients with low expression (69.3 and 68.1 months, P<0.05). The estimated OS (31.1 months) and PFS (13.1 months) of patients with high expression of B7-H3 were also lower than those of patients with low expression (69.3 and 66.6 months, P<0.05). Indeed, Cox multiple regression showed that OS and PFS were correlated with EGFR (relative risk =1.853, 1.875, respectively) and B7-H3 (relative risk =1.886, 2.061, respectively) (all P<0.05) expression level. Thus, EGFR and B7-H3 are highly expressed in tumor tissues of patients with ESCC. Their expression levels are correlated with tumor severity and survival, and therefore these may be viable biomarkers to aid in prognosis determination. PMID:27785073

  6. Monoclonal antibody-conjugated superparamagnetic iron oxide nanoparticles for imaging of epidermal growth factor receptor-targeted cells and gliomas.

    PubMed

    Mu, Ketao; Zhang, Shun; Ai, Tao; Jiang, Jingjing; Yao, Yihao; Jiang, Lingyu; Zhou, Qing; Xiang, Hongbing; Zhu, Yanhong; Yang, Xiangliang; Zhu, Wenzhen

    2015-01-01

    The objective of this study was to successfully synthesize epidermal growth factor receptor monoclonal antibody-conjugated superparamagnetic iron oxide nanoparticles (EGFRmAb-SPIONs) and explore their biocompatibility and potential applications as a targeted magnetic resonance imaging (MRI) contrast agent for the EGFR-specific detection of brain glioma in vivo. After conjugation of EGFRmAb with SPIONs, the magnetic characteristics of EGFRmAb-SPIONs were investigated. Thereafter, the targeting abilities of EGFRmAb-SPIONs with MRI were qualitatively and quantitatively assessed in EGFR-positive C6 glioma cells in vitro and in a Wistar rat model bearing C6 glioma in vivo. Furthermore, the preliminary biocompatibility and toxicity of EGFRmAb-SPIONs were evaluated in normal rats through hematology assays and histopathologic analyses. Statistical analysis was performed using one-way analysis of variance and Student t-test, with a significance level of p < .05. From the results of EGFRmAb-SPION characterizations, the average particle size was 10.21 nm and the hydrodynamic diameter was 161.5 ± 2.12 nm. The saturation magnetization was 55 emu/g·Fe, and T2 relaxivity was 92.73 s-1mM-1 in distilled water. The preferential accumulation of the EGFRmAb-SPIONs within glioma and subsequent MRI contrast enhancement were demonstrated both in vitro in C6 cells and in vivo in rats bearing C6 glioma. After intravenous administration of EGFRmAb-SPIONs, T2-weighted MRI of the rat model with brain glioma exhibited an apparent hypointense region within glioma from 2 to 48 hours. The maximal image contrast was reached at 24 hours, where the signal intensity decreased and the R2 value increased by 30% compared to baseline. However, T2-weighted imaging of the rat model administered with SPIONs showed no visible signal changes within the tumor over the same time period. Moreover, no evident toxicities in vitro and in vivo with EGFRmAb-SPIONs were clearly identified based on the laboratory

  7. Pertuzumab for the treatment of patients with human epidermal growth factor receptor 2-positive breast cancer in Japan

    PubMed Central

    OSAKO, TOMOFUMI; NISHIMURA, REIKI; NISHIYAMA, YASUYUKI; FUJISUE, MAMIKO

    2015-01-01

    Pertuzumab, a novel anti-human epidermal growth factor receptor 2 (HER2) agent, is effective for metastatic HER2-positive breast cancer when used in combination with taxane and trastuzumab. The aim of the present study was to describe the use of pertuzumab in Japan. A phase I clinical trial of pertuzumab for HER2-positive metastatic breast cancer was first conducted in the United States in 2001 (study ID no. TOC2297g) and for HER2-positive solid cancers in Japan in 2004 (study ID no. JO17076). However, Japanese patients were not enrolled in a global phase II trial for metastatic breast cancer (study ID no. BO17929) and no phase II trial of pertuzumab for Japanese patients has yet been conducted. A phase III trial on pertuzumab for metastatic breast cancer (CLEOPATRA study), which included 53 Japanese patients, revealed that pertuzumab significantly prolonged progression-free and overall survival. However, the superiority of the pertuzumab group was not verified in the subgroup analysis of Japanese patients, which was not a preplanned analysis. Therefore, a postmarketing clinical trial for Japanese patients with HER2-positive metastatic breast cancer (COMACHI study) was initiated in November, 2013, to investigate the clinical effectiveness of pertuzumab in Japanese patients. As of December, 2014, global trials on pertuzumab in the metastatic and adjuvant settings are currently ongoing. These trials included Japanese patients with HER2-positive breast cancer. Pertuzumab was approved in Japan in August, 2013 due to the positive findings of the CLEOPATRA study. Unlike the United States and Europe, the Japanes Pharmaceutical and Medical Devices Agency approved the administration of pertuzumab as second- or later-line treatment for HER2-positive metastatic breast cancer, as well as first-line treatment. Furthermore, pertuzumab may be used in combination with other chemotherapeutic agents, with the exception of docetaxel. The approval of the expanded use of pertuzumab is

  8. Small-animal PET imaging of human epidermal growth factor receptor positive tumor with a 64Cu labeled affibody protein.

    PubMed

    Miao, Zheng; Ren, Gang; Liu, Hongguang; Jiang, Lei; Cheng, Zhen

    2010-05-19

    Epidermal growth factor receptor (EGFR) has become an attractive target for cancer molecular imaging and therapy. Affibody proteins against EGFR have been reported, and thus, we were interested in evaluating their potential for positron emission tomography (PET) imaging of EGFR positive cancer. An Affibody analogue (Ac-Cys-Z(EGFR:1907)) binding to EGFR was made through conventional solid phase peptide synthesis. The purified protein was site-specifically coupled with the 1,4,7,10-tetraazacyclododecane-1,4,7-tris-aceticacid-10-maleimidethylacetamide (maleimido-mono-amide-DOTA) to produce the bioconjugate, DOTA-Z(EGFR:1907). (64)Cu labeled probe (64)Cu-DOTA-Z(EGFR:1907) displayed a moderate specific activity (5-8 MBq/nmol, 22-35 microCi/microg). Cell uptake assays by pre-incubating without or with 300 times excess unlabeled Ac-Cys-Z(EGFR:1907) showed high EGFR-specific uptake (20% applied activity at 0.5 h) in A431 epidermoid carcinoma cancer cells. The affinity (K(D)) of (64)Cu-DOTA-Z(EGFR:1907) as tested by cell saturation analysis was 20 nM. The serum stability test showed excellent stability of the probe with >95% intact after 4 h of incubation in mouse serum. In vivo small-animal PET imaging showed fast tumor targeting, high tumor accumulation (approximately 10% ID/g at 1 h p.i.), and good tumor-to-normal tissue contrast of (64)Cu-DOTA-Z(EGFR:1907) spiked with a wide dose range of Ac-Cys-Z(EGFR:1907). Bio-distribution studies further demonstrated that the probe had high tumor, blood, liver, and kidney uptakes, while blood radioactivity concentration dropped dramatically at increased spiking doses. Co-injection of the probe with 500 microg of Ac-Cys-Z(EGFR:1907) for blocking significantly reduced the tumor uptake. Thus, (64)Cu-DOTA-Z(EGFR:1907) showed potential as a high tumor contrast EGFR PET imaging reagent. The probe spiked with 50 microg of Ac-Cys-Z(EGFR:1907) improved tumor imaging contrast which may have important clinical applications. PMID:20402512

  9. Epidermal growth factor (EGF) promotes phosphorylation at threonine-654 of the EGF receptor: possible role of protein kinase C in homologous regulation of the EGF receptor

    SciTech Connect

    Whiteley, B.; Glaser, L.

    1986-10-01

    Treatment of cells with tumor-promoting phorbol diesters, which causes activation of protein kinase C, leads to phosphorylation of the epidermal growth factor (EGF) receptor at threonine-654. Addition of phorbol diesters to intact cells causes inhibition of the EGF-induced tyrosine-protein kinase activity of the EGF receptor and it has been suggested that this effect of phorbol diesters is mediated by the phosphorylation of the receptor by protein kinase C. The authors measured the activity of protein kinase C in A431 cells by determining the incorporation of (/sup 32/P)phosphate into peptides containing threonine-654 obtained by trypsin digestion of EGF receptors. After 3 h of exposure to serum-free medium, A431 cells had no detectable protein kinase C activity. Addition of EGF to these cells resulted in (/sup 32/P) incorporation into threonine-654 as well as into tyrosine residues. This indicates that EGF promotes the activation of protein kinase C in A431 cells. The phophorylation of threonine-654 induced by EGF was maximal after only 5 min of EGF addition and the (/sup 32/P) incorporation into threonine-654 reached 50% of the (/sup 32/P) in a tyrosine-containing peptide. This indicates that a significant percentage of the total EGF receptors are phosphorylated by protein kinase C. A variety of external stimuli activate Na/sup +//H/sup +/ exchange, including EGF, phorbol diesters, and hypertonicity. To ascertain whether activation of protein kinase C is an intracellular common effector of all of these systems, the authors measured the activity of protein kinase C after exposure of A431 cells to hyperosmotic conditions and observed no effect on phosphorylation of threonine-654, therefore, activation of Na/sup +//H/sup +/ exchange by hypertonic medium is independent of protein kinase C activity.

  10. Oxidative inhibition of receptor-type protein-tyrosine phosphatase kappa by ultraviolet irradiation activates epidermal growth factor receptor in human keratinocytes.

    PubMed

    Xu, Yiru; Shao, Yuan; Voorhees, John J; Fisher, Gary J

    2006-09-15

    Ultraviolet (UV) irradiation rapidly increases tyrosine phosphorylation (i.e. activates) of epidermal growth factor receptors (EGFR) in human skin. EGFR-dependent signaling pathways drive increased expression of matrix metalloproteinases, whose actions fragment collagen and elastin fibers, the primary structural protein components in skin connective tissue. Connective tissue fragmentation, which results from chronic exposure to solar UV irradiation, is a major determinant of premature skin aging (photoaging). UV irradiation generates reactive oxygen species, which readily react with conserved cysteine residues in the active site of protein-tyrosine phosphatases (PTP). We report here that EGFR activation by UV irradiation results from oxidative inhibition of receptor type PTP-kappa (RPTP-kappa). RPTP-kappa directly counters intrinsic EGFR tyrosine kinase activity, thereby maintaining EGFR in an inactive state. Reversible, oxidative inactivation of RPTP-kappa activity by UV irradiation shifts the kinase-phosphatase balance in favor of EGFR activation. These data delineate a novel mechanism of EGFR regulation and identify RPTP-kappa as a key molecular target for antioxidant protection against skin aging.

  11. Epidermal growth factor, from gene organization to bedside

    PubMed Central

    Zeng, Fenghua; Harris, Raymond C.

    2014-01-01

    In 1962, epidermal growth factor (EGF) was discovered by Dr. Stanley Cohen while studying nerve growth factor (NGF). It was soon recognized that EGF is the prototypical member of a family of peptide growth factors that activate the EGF receptors, and that the EGF/EGF receptor signaling pathway plays important roles in proliferation, differentiation and migration of a variety of cell types, especially in epithelial cells. After the basic characterization of EGF function in the first decade or so after its discovery, the studies related to EGF and its signaling pathway have extended to a broad range of investigations concerning its biological and pathophysiological roles in development and in human diseases. In this review, we briefly describe the gene organization and tissue distribution of EGF, with emphasis on its biological and pathological roles in human diseases. PMID:24513230

  12. Androgen Receptor Expression in Prostate Cancer Cells Is Suppressed by Activation of Epidermal Growth Factor Receptor and ErbB2

    PubMed Central

    Cai, Changmeng; Portnoy, David C.; Wang, Hongyun; Jiang, Xinnong; Chen, Shaoyong; Balk, Steven P.

    2016-01-01

    Prostate cancers (PCa) that relapse after androgen deprivation therapies [castration-resistant PCa (CRPC)] express high levels of androgen receptor (AR) and androgen-regulated genes, and evidence from several groups indicates that ErbB family receptor tyrosine kinases [epidermal growth factor (EGF) receptor (EGFR) and ErbB2] may contribute to enhancing this AR activity. We found that activation of these kinases with EGF and heregulin-β1 rapidly (within 8 hours) decreased expression of endogenous AR and androgen-regulated PSA in LNCaP PCa cells. AR expression was similarly decreased in LAPC4 and C4-2 cells, but not in the CWR22Rv1 PCa cell line. The rapid decrease in AR was not due to increased AR protein degradation and was not blocked by phosphatidylinositol 3-kinase (LY294002) or MEK (UO126) inhibitors. Significantly, AR mRNA levels in LNCaP cells were markedly decreased by EGF and heregulin-β1, and experiments with actinomycin D to block new mRNA synthesis showed that AR mRNA degradation was increased. AR mRNA levels were still markedly decreased by EGF and heregulin-β1 in LNCaP cells adapted to growth in androgen-depleted medium, although AR protein levels did not decline due to increased AR protein stability. These findings show that EGFR and ErbB2 can negatively regulate AR mRNA and may provide an approach to suppress AR expression in CRPC. PMID:19491261

  13. Assessment of Hormone Receptor and Human Epidermal Growth Factor Receptor 2 Status in Breast Carcinoma Using Thin-Prep Cytology Fine Needle Aspiration Cytology FISH Experience From China

    PubMed Central

    Zhang, Zhihui; Yuan, Peng; Guo, Huiqin; Zhao, Linlin; Ying, Jianming; Wang, Mingrong; Zhao, Huan; Pan, Qinjing; Xu, Binghe

    2015-01-01

    Abstract Estrogen receptor (ER) and progesterone receptor (PR) overexpression can be used to predict patient prognosis in breast cancer (BC). Human epidermal growth factor receptor 2 (HER2) is a reliable predictive marker in invasive breast cancer (IBC). Thin-Prep (TP) specimens are commonly utilized for immunocytochemistry (ICC) in fine needle aspiration cytology (FNAC). Thus, we sought to investigate if the incorporation of molecular diagnosis performed on TP-processed specimens is applicable in clinical practice. Hormone receptors (HRs) and HER2 immunocytochemistry was performed on 542 primary breast cancer FNAC specimens using the TP method. One hundred fourteen HER2 fluorescence in situ hybridization (FISH) analyses were performed on HER2 ICC 2+ FNAC specimens and the corresponding tissue samples. HRs results of TP slides and those of formalin-fixed paraffin-embedded (FFPE) slides were correlated well for ER (concordance rate = 93.3%, kappa value = 0.85) and PR (concordance rate = 88.6%, kappa value = 0.75). HER2 results for the TP slides and those of the matched FFPE slides also correlated well (concordance rate = 80.0%, kappa value = 0.62). The specificity of HER2 was 97.3%; however, the sensitivity was only 67.1%. Cytological specimens and histological samples showed a strong correlation (concordance rate = 99.1%, kappa value = 0.98) while being used to evaluate HER2 gene amplification. FNAC is a minimally invasive technique that can be used as an alternative method to collect tissue especially in cases where an excisional or core biopsy is difficult to obtain, or when recurrence is present. The results of ICC HRs in FNAC TP specimens may be used instead, but HER2 assessment may not be reliable enough for clinical use. FISH testing is necessary in this setting. PMID:26091472

  14. Epidermal growth factor receptor (EGFR) signaling requires a specific endoplasmic reticulum thioredoxin for the post-translational control of receptor presentation to the cell surface.

    PubMed

    Dong, Aiwen; Wodziak, Dariusz; Lowe, Anson W

    2015-03-27

    The epidermal growth factor receptor (EGFR) is a well characterized receptor-tyrosine kinase that functions in development and serves a vital role in many human cancers. Understanding EGFR regulatory mechanisms, and hence approaches for clinical intervention, has focused on ligand-receptor interactions and tyrosine kinase activity. Here, we show using the NCI-H460 lung and A431 epidermoid human cancer cell lines that EGFR binding to anterior gradient homolog 2 (AGR2) in the endoplasmic reticulum is required for receptor delivery to the plasma membrane and thus EGFR signaling. Reduced AGR2 protein levels or mutation of an essential cysteine in the active site result in decreased cell surface EGFR and a concomitant decrease in signaling as reflected by AREG, EGR1, and FOS expression. Similar to previously described EGFR nulls, an AGR2 null also resulted in embryonic lethality. Consistent with its role in regulating EGFR-mediated signaling, AGR2 expression is also enhanced in many human cancers and promotes the transformed phenotype. Furthermore, EGFR-mediated signaling in NCI-H460 cells, which are resistant to the tyrosine kinase inhibitor AG1478, is also disrupted with reduced AGR2 expression. The results provide insights into why cancer prognosis or response to therapy often does not correlate with EGFR protein or RNA levels because they do not reflect delivery to the cell surface where signaling is initiated. AGR2, therefore, represents a novel post-translational regulator of EGFR-mediated signaling and a promising target for treating human cancers.

  15. 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.

    PubMed

    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 ( < 0.05) protein synthesis rates and decreased ( < 0.05) protein degradation rates when compared to control cultures. Treatment of fused BSC cultures with 10 n TBA in the presence of inhibitors for GPCR, MMP2/9, hbEGF, EGFR, erbB2, or IGF-1R suppressed ( < 0.05) TBA-mediated increases in protein synthesis rate. Alternatively, inhibition of GPCR, MMP2/9, hbEGF, EGFR, erbB2, or IGF-1R in the presence of 10 n TBA each had no ( > 0.05) effect on TBA-mediated decreases in protein degradation. However, inhibition of both EGFR and erbB2 in the presence of 10 n TBA resulted in decreased ( < 0.05) ability of TBA to decrease protein degradation rate. Additionally, fused BSC cultures treated with 10 n

  16. 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.

    PubMed

    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 ( < 0.05) protein synthesis rates and decreased ( < 0.05) protein degradation rates when compared to control cultures. Treatment of fused BSC cultures with 10 n TBA in the presence of inhibitors for GPCR, MMP2/9, hbEGF, EGFR, erbB2, or IGF-1R suppressed ( < 0.05) TBA-mediated increases in protein synthesis rate. Alternatively, inhibition of GPCR, MMP2/9, hbEGF, EGFR, erbB2, or IGF-1R in the presence of 10 n TBA each had no ( > 0.05) effect on TBA-mediated decreases in protein degradation. However, inhibition of both EGFR and erbB2 in the presence of 10 n TBA resulted in decreased ( < 0.05) ability of TBA to decrease protein degradation rate. Additionally, fused BSC cultures treated with 10 n

  17. Epidermal growth factor (urogastrone) in human tissues.

    PubMed

    Hirata, Y; Orth, D N

    1979-04-01

    Human epidermal growth factor (hEGF), which stimulates the growth of a variety of tissues, was first isolated from mouse submandibular glands, but is also excreted in large amounts (about 50 micrograms/day) in human urine and is probably identical to human beta-urogastrone (hUG), a potent inhibitor of stimulated gastric acid secretion. However, the primary tissue source of hEGF/hUG is as yet unknown. The hEGF/hUG in homogenates of human salivary glands and a wide variety of other endocrine and nonendocrine tissues was extracted by Amberlite CG-50 cation exchange chromatography and immune affinity chromatography using the immunoglobulin fraction of rabbit anti-hEGF serum covalently bound to agarose. The extracts were subjected to homologous hEGF RIA. Immunoreactive hEGF was found in extracts of adult submandibular gland, thyroid gland, duodenum, jejunum, and kidney, but not in several fetal tissues. The tissue immunoreactive hEGF was similar to standard hEGF in terms of immunoreactivity and elution from Sephadex G-50 Fine resin, but its concentrations were very low (1.3-5.5 ng/g wet tissue). Thus, it is not certain that these tissues represent the only source of the large amounts of hEGF/hUG that appear to be filtered by the kidneys each day.

  18. Plumbagin Ameliorates CCl4-Induced Hepatic Fibrosis in Rats via the Epidermal Growth Factor Receptor Signaling Pathway

    PubMed Central

    Chen, Si; Chen, Yi; Chen, Bi; Cai, Yi-jing; Zou, Zhuo-lin; Wang, Jin-guo; Lin, Zhuo; Wang, Xiao-dong; Fu, Li-yun; Hu, Yao-ren; Chen, Yong-ping; Chen, Da-zhi

    2015-01-01

    Epidermal growth factor (EGF) and its signaling molecules, EGFreceptor (EGFR) and signal transducer and activator of transcription factor 3 (STAT3), have been considered to play a role in liver fibrosis and cirrhosis. Plumbagin (PL) is an extracted component from the plant and has been used to treat different kinds of cancer. However, its role in regulation of EGFR and STAT3 during liver fibrosis has not been investigated. In this study, the effects of PL on the regulation of EGFR and STAT3 were investigated in carbon tetrachloride (CCl4) induced liver fibrosis and hepatic stellate cells (HSC-T6). PL significantly attenuated liver injury and fibrosis in CCl4 treated rats. At concentrations of 2 to 6 μM, PL did not induce significant cytotoxicity of HSC-T6 cells. Moreover, PL reduced phosphorylation of EGFR and STAT3 in both fibrotic liver and heparin-binding EGF-like growth factor (HB-EGF) treated HSC-T6 cells. Furthermore, PL reduced the expression of α-SMA, EGFR, and STAT3 in both fibrotic liver and HB-EGF treated HSC-T6 cells. In conclusion, plumbagin could ameliorate the development of hepatic fibrosis through its downregulation of EGFR and STAT3 in the liver, especially in hepatic stellate cells. PMID:26550019

  19. Epitope mapping of epidermal growth factor receptor (EGFR) monoclonal antibody and induction of growth-inhibitory polyclonal antibodies by vaccination with EGFR mimotope.

    PubMed

    Navari, Mohsen; Zare, Mehrak; Javanmardi, Masoud; Asadi-Ghalehni, Majid; Modjtahedi, Helmout; Rasaee, Mohammad Javed

    2014-10-01

    One of the proposed approaches in cancer therapy is to induce and direct the patient's own immune system against cancer cells. In this study, we determined the epitope mapping of the rat anti-human epidermal growth factor receptor (EGFR) monoclonal antibody ICR-62 using a phage display of random peptide library and identified a 12 amino acids peptide, which was recognized as a mimotope. The peptide was synthesized and conjugated to bovine serum albumin (BSA) as carrier protein (P-BSA). We have shown that ICR-62 can react specifically with P-BSA as well as native EGFR. Two rabbits were immunized either by BSA or P-BSA and the rabbits IgGs were purified and examined for binding to the antigens, mimotope and the EGFR protein purified from the EGFR overexpressing A431 cell line. We showed that the rabbit IgG generated against the mimotope is capable of inhibiting the growth of A431 cells by 15%, but does not have any effect on the growth of EGFR-negative MDA-MB-453 cell line in vitro. Our results support the need for further investigations on the potential of vaccination with either mimotope of the EGFR or epitope displayed on the surface of phage particles for use in active immunotherapy of cancer.

  20. Neoadjuvant and adjuvant epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) therapy for lung cancer

    PubMed Central

    Zhai, Haoran; Zhong, Wenzhao; Yang, Xuening

    2015-01-01

    The Lung Adjuvant Cisplatin Evaluation (LACE) meta-analysis and the meta-analysis of individual participant data reported by non-small cell lung cancer (NSCLC) Meta-analysis Collaborative Group in neo-adjuvant setting validated respectively that adjuvant and neoadjuvant chemotherapy would significantly improve overall survival (OS) and recurrence-free survival for resectable NSCLC. However, chemotherapy has reached a therapeutic plateau. It has been confirmed that epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) targeting therapy provides a dramatic response to patients with advanced EGFR-mutation positive NSCLC. Researchers have paid more attention to exploring applications of TKIs to early resectable NSCLCs. Several studies on adjuvant TKI treatment concluded its safety and feasibility. But there existed certain limitations of these studies as inference factors to interpret data accurately: the BR19 study recruited patients among which almost 52% had stage IB and only 15 (3.0%, 15/503) had been confirmed with EGFR-mutant type; retrospective studies performed at Memorial Sloan Kettering Cancer Center (MSKCC) selected EGFR mutant-type NSCLC patients but couldn’t avoid inherent defects inside retrospective researches; the RADIANT study revised endpoints from targeting at EGFR immunohistochemistry (IHC)+ and/or fluorescence in situ hybridization (FISH)+ mutation to only EGFR IHC+ mutation, leading to selective bias; despite that the SELECT study validated efficacy of adjuvant TKI and second round of TKI after resistance occurred, a single-arm clinical trial is not that persuasive in the absence of comparison with chemotherapy. Taking all these limitations into account, CTONG1104 in China and IMPACT in Japan have been conducted and recruiting patients to offer higher level of evidences to explore efficacy of preoperative TKI therapy for early resectable EGFR mutation positive NSCLC patients (confirmed by pathological results of tumor tissue or

  1. Dual Inhibition of Epidermal Growth Factor Receptor and Insulin-like Growth Factor Receptor I Reduces Angiogenesis and Tumor Growth in Cutaneous Squamous Cell Carcinoma

    PubMed Central

    Galer, Chad E.; Corey, Christina L.; Wang, Zhuoying; Younes, Maher N.; Gomez-Rivera, Fernando; Jasser, Samar A.; Ludwig, Dale L.; El-Naggar, Adel K.; Weber, Randal S.; Myers, Jeffrey N.

    2010-01-01

    Purpose Cutaneous squamous cell carcinoma (CSCC) is the second most common non-melanoma skin cancer. The majority of the ~250,000 cases occurring annually in the United States are small, non-aggressive, and cured by excision alone. However, a subset of these tumors which are defined by poorly differentiated histology, large tumor size, invasion of adjacent structures and/or regional metastases can prove resistant to treatment despite adjuvant radiotherapy and have increased risk of recurrence and nodal metastasis. Novel therapeutic approaches are necessary to improve outcomes for patients with aggressive CSCC. Experimental Design We analyzed the effect of targeted therapy on the growth and survival of CSCC cell lines using an anti-IGF-IR antibody, A12, alone or in combination with an anti-EGF-R antibody, cetuximab, both in vitro and in vivo in an athymic nude mouse model of CSCC. Results Treatment with A12 and cetuximab inhibited the signaling pathways of IGF-IR and EGFR and inhibited proliferation and induced apoptosis of SCC cell lines in vitro. Immunohistochemical staining revealed decreased proliferating cell nuclear antigen (PCNA) and microvessel density (MVD) as well as increased apoptosis within the treated tumor xenografts. In addition, the administration of A12, alone or in combination with cetuximab inhibited the growth of tumors by 51% and 92% respectively, and significantly enhanced survival in the nude mouse model of CSCC (p = 0.044 and p < 0.001 respectively). Conclusions These data suggest that dual treatment with monoclonal antibodies to the EGFR and IGF-IR may be therapeutically useful in the treatment of CSCC. PMID:20848439

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

    PubMed Central

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

    2016-01-01

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

  3. [Epidermal growth factor, innovation and safety].

    PubMed

    Esquirol Caussa, Jordi; Herrero Vila, Elisabeth

    2015-10-01

    Bioidentical recombinant human epidermal growth factor (rhEGF) is available in concentrations and purity suitable for therapeutic use in long time stable formulations. Beneficial effects in several skin pathologies and lesions have been reported (traumatic and surgical wound healing, laser induced wounds, abnormal scars, keloids, radiation or chemotherapy induced dermatitis, post inflammatory hyperpigmentation or for skin aging damage repairing) and also may be considered for the treatment of several oropharingeal and high gastroesophageal tract mucosa diseases (mouth sores, pharyngeal fistulas, ulcers), and several corneal or conjunctive mucosa lesions. rhEGF has not shown any important side or collateral effects in humans or in laboratory experimentation animals, showing optimal tolerability and safety with continuous use for months. Compounding gives advantages of versatility, individualization, personalization, molecular stability, safety and effectiveness in ideal conditions, showing good tissue penetration, both on intact skin and skin lesions that expose the lower planes to the surface. rhEGF compounds can be considered for prevention or as a treatment of diverse skin and mucosa diseases and conditions through compounding preparations.

  4. Activation of Epidermal Growth Factor Receptor in Macrophages Mediates Feedback Inhibition of M2 Polarization and Gastrointestinal Tumor Cell Growth.

    PubMed

    Zhao, Gang; Liu, Liping; Peek, Richard M; Hao, Xishan; Polk, D Brent; Li, Hui; Yan, Fang

    2016-09-23

    EGF receptor (EGFR) in tumor cells serves as a tumor promoter. However, information about EGFR activation in macrophages in regulating M2 polarization and tumor development is limited. This study aimed to investigate the effects of EGFR activation in macrophages on M2 polarization and development of gastrointestinal tumors. IL-4, a cytokine to elicit M2 polarization, stimulated release of an EGFR ligand, HB-EGF, and transactivation and down-regulation of EGFR in Raw 264.7 cells and peritoneal macrophages from WT mice. Knockdown of HB-EGF in macrophages inhibited EGFR transactivation by IL-4. IL-4-stimulated STAT6 activation, Arg1 and YM1 gene expression, and HB-EGF production were further enhanced by inhibition of EGFR activity in Raw 264.7 cells using an EGFR kinase inhibitor and in peritoneal macrophages from Egfr(wa5) mice with kinase inactive EGFR and by knockdown of EGFR in peritoneal macrophages from Egfr(fl/fl) LysM-Cre mice with myeloid cell-specific EGFR deletion. Chitin induced a higher level of M2 polarization in peritoneal macrophages in Egfr(fl/fl) LysM-Cre mice than that in Egfr(fl/fl) mice. Accordingly, IL-4-conditioned medium stimulated growth and epithelial-to-mesenchymal transition in gastric epithelial and colonic tumor cells, which were suppressed by that from Raw 264.7 cells with HB-EGF knockdown but promoted by that from Egfr(wa5) and Egfr(fl/fl) LysM-Cre peritoneal macrophages. Clinical assessment revealed that the number of macrophages with EGFR expression became less, indicating decreased inhibitory effects on M2 polarization, in late stage of human gastric cancers. Thus, IL-4-stimulated HB-EGF-dependent transactivation of EGFR in macrophages may mediate inhibitory feedback for M2 polarization and HB-EGF production, thereby inhibiting gastrointestinal tumor growth.

  5. Ganoderma tsugae extract inhibits expression of epidermal growth factor receptor and angiogenesis in human epidermoid carcinoma cells: In vitro and in vivo.

    PubMed

    Hsu, Shih-Chung; Ou, Chien-Chih; Chuang, Tzu-Chao; Li, Jhy-Wei; Lee, Yi-Jen; Wang, Vinchi; Liu, Jah-Yao; Chen, Chin-Shiang; Lin, Song-Chow; Kao, Ming-Ching

    2009-08-18

    We examined the anti-angiogenic effects of Ganoderma tsugae methanol extract (GTME) on human epidermoid carcinoma A-431 cells. Our data indicate that GTME inhibits the expression of epidermal growth factor receptor (EGFR) and vascular endothelial growth factor (VEGF) in vitro and in vivo, and also inhibits the capillary tube formation of human umbilical vein endothelial cells (HUVECs). We also show that the suppression of VEGF expression by GTME can be restored by treatment with EGF. These results suggest that GTME inhibits VEGF expression via the suppression of EGFR expression, resulting in the downregulation of VEGF secretion from epidermoid carcinoma A-431 cells. These findings reveal a novel role for G. tsugae in inhibiting EGFR and VEGF expression, which are important for tumor angiogenesis and growth. Thus, GTME may provide a potential therapeutic approach for anti-tumor treatment. PMID:19332363

  6. Assessment of epidermal growth factor receptor mutation/copy number and K-ras mutation in esophageal cancer

    PubMed Central

    Guo, Kang; Wang, Wu-Ping; Jiang, Tao; Wang, Ju-Zheng; Chen, Zhao; Li, Yong; Zhou, Yong-An; Li, Xiao-Fei

    2016-01-01

    Background The molecular status of epidermal growth factor receptor (EGFR) in esophageal cancer has not been well elucidated. The purpose of the study was to investigate the prevalence of EGFR and K-ras mutation, and EGFR gene copy number status as well as its association with clinicopathologic characteristics, and also to identify the prognostic value of EGFR gene copy number in esophageal cancer. Methods EGFR mutation in exon 19/exon 21 and K-ras mutation in codon 12/codon 13 were detected by real-time PCR method, while EGFR gene copy number status was analyzed by fluorescent in situ hybridization (FISH). EGFR gene amplification and high polysomy were defined as high EGFR gene copy number status (FISH-positive), and all else were defined as low EGFR gene copy number status (FISH-negative). The relationship between EGFR gene copy number status and clinicpathologic characteristics was analyzed. Kaplan-Meier method and Cox proportional hazards regression model were employed to evaluate the effects of EGFR gene copy number status on the patients’ survival. Results A total of 57 esophageal squamous cell carcinoma (ESCC) patients and 9 esophageal adenocarcinoma (EADC) patients were enrolled in the study. EGFR mutation was identified in one patient who was diagnosed as ESCC with stage IIIC disease. K-ras mutation was identified in one patient who was diagnosed as EADC. In all, 34 of 66 (51.5%) samples were detected as FISH-positive, which includes 30 ESCC and 4 EADC tumor samples. The correlation analysis showed that FISH-positive was significantly associated with the tumor stage (P=0.019) and lymph node metastasis (P=0.005) in esophageal cancer patients, and FISH-positive was also significantly associated with the tumor stage (P=0.007) and lymph node metastasis (P=0.008) in ESCC patients. Cox regression analysis showed that high EGFR gene copy number was not a significant predictor of a poor outcome for esophageal cancer patients (P=0.251) or for ESCC patients (P=0

  7. Receptor-binding, biodistribution, and metabolism studies of 64Cu-DOTA-cetuximab, a PET-imaging agent for epidermal growth-factor receptor-positive tumors.

    PubMed

    Ping Li, Wen; Meyer, Laura A; Capretto, David A; Sherman, Christopher D; Anderson, Carolyn J

    2008-04-01

    The epidermal growth-factor receptor (EGFR) and its ligands have been recognized as critical factors in the pathophysiology of tumorigenesis. Overexpression of the EGFR plays a significant role in the tumor progression of a wide variety of solid human cancers. Therefore, the EGFR represents an attractive target for the design of novel diagnostic and therapeutic agents for cancer. Cetuximab (C225, Erbitux) was the first monoclonal antibody targeted against the ligand-binding site of EGFR approved by the Food and Drug Administration for the treatment of patients with EGFR-expressing, metastatic colorectal carcinoma, although clinical trials showed variability in the response to this treatment. The aim of this study involved using cetuximab to design a positron emission tomography (PET) agent to image the overexpression of EGFR in tumors. Cetuximab was conjugated with the chelator, DOTA, for radiolabeling with the positron-emitter, 64Cu (T(1/2) = 12.7 hours). 64Cu-DOTA-cetuximab showed high binding affinity to EGFR-positive A431 cells (K(D) of 0.28 nM). Both biodistribution and microPET imaging studies with 64Cu-DOTA-cetuximab demonstrated greater uptake at 24 hours postinjection in EGFR-positive A431 tumors (18.49% +/- 6.50% injected dose per gram [ID/g]), compared to EGFR-negative MDA-MB-435 tumors (2.60% +/- 0.35% ID/g). A431 tumor uptake at 24 hours was blocked with unlabeled cetuximab (10.69% +/- 2.72% ID/g), suggesting that the tumor uptake was receptor mediated. Metabolism experiments in vivo showed that 64Cu-DOTA-cetuximab was relatively stable in the blood of tumor-bearing mice; however, there was significant metabolism in the liver and tumors. 64Cu-DOTA-cetuximab is a potential agent for imaging EGFR-positive tumors in humans.

  8. Id-1 expression induces androgen-independent prostate cancer cell growth through activation of epidermal growth factor receptor (EGF-R).

    PubMed

    Ling, Ming-Tat; Wang, Xianghong; Lee, Davy T; Tam, P C; Tsao, Sai-Wah; Wong, Yong-Chuan

    2004-04-01

    The failure of prostate cancer treatment is largely due to the development of androgen independence, since the androgen depletion therapy remains the front-line option for this cancer. Previously, we reported that over-expression of the helix-loop-helix protein Id-1 was associated with progression of prostate cancer and ectopic expression of Id-1 induced serum-independent proliferation in prostate cancer cells. In the present study, we investigated if exogenous Id-1 expression in the androgen sensitive LNCaP cells had any effect on androgen-dependent cell growth and studied the molecular mechanisms involved. Using stable Id-1 transfectants, we found that expression of Id-1 was able to reduce androgen-stimulated growth and S phase fraction of the cell cycle in LNCaP cells, indicating that Id-1 may be involved in the development of androgen independence in these cells. The Id-1-induced androgen-independent prostate cancer cell growth was correlated with up-regulation of EGF-R (epidermal growth factor-receptor) and PSA (prostate specific antigen) expression, as confirmed by western blotting analysis and luciferase assays. In contrast, down-regulation of Id-1 in androgen-independent DU145 cells by its antisense oligonucleotides resulted in suppression of EGF-R expression at both transcriptional and protein levels. In addition, the results from immunohistochemistry study showed that Id-1 expression was significantly elevated in hormone refractory prostate cancer tissues when compared with the hormone-dependent tumours. Our results suggest that up-regulation of Id-1 in prostate cancer cells may be one of the mechanisms responsible for developing androgen independence and this process may be regulated through induction of EGF-R expression. Inactivation of Id-1 may provide a potential therapeutic strategy leading to inhibition of androgen-independent prostate cancer cell growth.

  9. Transactivation of epidermal growth factor receptor in vascular and renal systems in rats with experimental hyperleptinemia: role in leptin-induced hypertension.

    PubMed

    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.

  10. Activated Protein C Enhances Human Keratinocyte Barrier Integrity via Sequential Activation of Epidermal Growth Factor Receptor and Tie2*

    PubMed Central

    Xue, Meilang; Chow, Shu-Oi; Dervish, Suat; Chan, Yee-Ka Agnes; Julovi, Sohel M.; Jackson, Christopher J.

    2011-01-01

    Keratinocytes play a critical role in maintaining epidermal barrier function. Activated protein C (APC), a natural anticoagulant with anti-inflammatory and endothelial barrier protective properties, significantly increased the barrier impedance of keratinocyte monolayers, measured by electric cell substrate impedance sensing and FITC-dextran flux. In response to APC, Tie2, a tyrosine kinase receptor, was rapidly activated within 30 min, and relocated to cell-cell contacts. APC also increased junction proteins zona occludens, claudin-1 and VE-cadherin. Inhibition of Tie2 by its peptide inhibitor or small interfering RNA abolished the barrier protective effect of APC. Interestingly, APC did not activate Tie2 through its major ligand, angiopoietin-1, but instead acted by binding to endothelial protein C receptor, cleaving protease-activated receptor-1 and transactivating EGF receptor. Furthermore, when activation of Akt, but not ERK, was inhibited, the barrier protective effect of APC on keratinocytes was abolished. Thus, APC activates Tie2, via a mechanism requiring, in sequential order, the receptors, endothelial protein C receptor, protease-activated receptor-1, and EGF receptor, which selectively enhances the PI3K/Akt signaling to enhance junctional complexes and reduce keratinocyte permeability. PMID:21173154

  11. Activation of the human keratinocyte B1 bradykinin receptor induces expression and secretion of metalloproteases 2 and 9 by transactivation of epidermal growth factor receptor.

    PubMed

    Matus, Carola E; Ehrenfeld, Pamela; Pavicic, Francisca; González, Carlos B; Concha, Miguel; Bhoola, Kanti D; Burgos, Rafael A; Figueroa, Carlos D

    2016-09-01

    The B1 bradykinin receptor (BDKRB1) is a component of the kinin cascade localized in the human skin. Some of the effects produced by stimulation of BDKRB1 depend on transactivation of epidermal growth factor receptor (EGFR), but the mechanisms involved in this process have not been clarified yet. The primary purpose of this study was to determine the effect of a BDKRB1 agonist on wound healing in a mouse model and the migration and secretion of metalloproteases 2 and 9 from human HaCaT keratinocytes and delineate the signalling pathways that triggered their secretion. Although stimulation of BDKRB1 induces weak chemotactic migration of keratinocytes and wound closure in an in vitro scratch-wound assay, the BDKRB1 agonist improved wound closure in a mouse model. BDKRB1 stimulation triggers synthesis and secretion of both metalloproteases, effects that depend on the activity of EGFR and subsequent phosphorylation of ERK1/2 and p38 mitogen-activated protein kinases and PI3K/Akt. In the mouse model, immunoreactivity for both gelatinases was concentrated around wound borders. EGFR transactivation by BDKRB1 agonist involves Src kinases family and ADAM17. In addition to extracellular matrix degradation, metalloproteases 2 and 9 regulate cell migration and differentiation, cell functions that are associated with the role of BDKRB1 in keratinocyte differentiation. Considering that BDKRB1 is up-regulated by inflammation and/or by cytokines that are abundant in the inflammatory milieu, more stable BDKRB1 agonists may be of therapeutic value to modulate wound healing.

  12. The renin-angiotensin system mediates epidermal growth factor receptor-vitamin D receptor cross-talk in colitis-associated colon cancer

    PubMed Central

    Sadiq, Farhana; Almoghrabi, Anas; Mustafi, Devkumar; Kreisheh, Maggi; Sundaramurthy, Sumana; Liu, Weicheng; Konda, Vani J.; Pekow, Joel; Khare, Sharad; Hart, John; Joseph, Loren; Wyrwicz, Alice; Karczmar, Gregory S.; Li, Yan Chun; Bissonnette, Marc

    2014-01-01

    Purpose We previously showed that epidermal growth factor receptor (EGFR) promotes tumorigenesis in the azoxymethane/dextran sulfate sodium (AOM/DSS) model, whereas vitamin D (VD) suppresses tumorigenesis. EGFR-vitamin D receptor (VDR) interactions, however, are incompletely understood. VD inhibits the renin-angiotensin system (RAS), whereas RAS can activate EGFR. We aimed to elucidate EGFR-VDR cross-talk in colorectal carcinogenesis. Experimental Design To examine VDR-RAS interactions, we treated Vdr+/+ and Vdr/− mice with AOM/DSS. Effects of VDR on RAS and EGFR were examined by Westerns, immunostaining and real time PCR. We also examined the effect of vitamin D3 on colonic RAS in Vdr+/+ mice. EGFR regulation of VDR was examined in hypomorphic EgfrWaved2 (Wa2) and Egfrwildtype mice. Ang II-induced EGFR activation was studied in cell culture. Results Vdr deletion significantly increased tumorigenesis, activated EGFR and βcatenin signaling and increased colonic RAS components: including renin and angiotensin II. Dietary VD3 supplementation suppressed colonic renin. Renin was increased in human colon cancers. In studies in vitro, Ang II activated EGFR and stimulated colon cancer cell proliferation by an EGFR-mediated mechanism. Ang II also activated macrophages and colonic fibroblasts. Compared to tumors from EgfrWaved2 mice, tumors from Egfrwildtype mice showed up-regulated Snail1, a suppressor of VDR, and down-regulated VDR. Conclusions VDR suppresses the colonic RAS cascade, limits EGFR signals and inhibits colitis-associated tumorigenesis, whereas EGFR increases Snail1 and down-regulates VDR in colonic tumors. Taken together, these results uncover a RAS-dependent mechanism mediating EGFR and VDR cross-talk in colon cancer. PMID:25212605

  13. Ultraviolet B-induced activated protein-1 activation does not require epidermal growth factor receptor but is blocked by a dominant negative PKClambda/iota.

    PubMed

    Huang, C; Ma, W y; Bowden, G T; Dong, Z

    1996-12-01

    The exposure of mammalian cells to UV irradiation leads to the activation of transcription factors such as activated protein-1 (AP-1) and NFkappaB. It is postulated that epidermal growth factor (EGF) receptor, but not protein kinase C (PKC), is the major membrane mediator in UV-induced signal transduction. Since UVB is responsible for most of the carcinogenic effects of sun exposure, we investigated the role of EGF receptors and PKC in UVB-induced AP-1 activation. Our results indicated that while the down-regulation of novel PKC (nPKC) and conventional PKC (cPKC) by pretreatment of cells with 12-O-tetradecanoyl phorbol-13-acetate cannot block UVB-induced AP-1 activity, it can block 12-O-tetradecanoyl phorbol-13-acetate-induced AP-1 activity. Further, the dominant negative mutant PKClambda/iota blocked UVB-induced AP-1 activity in all doses and time courses studied. In contrast, UVB-induced AP-1 activity from cells devoid of EGF receptor (B82) was not significantly different from that of the stable transfectants with a kinase-deficient EGF receptor (B82M721) or those with a wild-type EGF receptor (B82L) at all UVB irradiation doses and time courses studied. All of this evidence indicated that aPKC, but not EGF receptor, is involved in UVB-induced AP-1 activation. PMID:8940130

  14. Cell-free synthesis of functional human epidermal growth factor receptor: Investigation of ligand-independent dimerization in Sf21 microsomal membranes using non-canonical amino acids

    PubMed Central

    Quast, Robert B.; Ballion, Biljana; Stech, Marlitt; Sonnabend, Andrei; Varga, Balázs R.; Wüstenhagen, Doreen A.; Kele, Péter; Schiller, Stefan M.; Kubick, Stefan

    2016-01-01

    Cell-free protein synthesis systems represent versatile tools for the synthesis and modification of human membrane proteins. In particular, eukaryotic cell-free systems provide a promising platform for their structural and functional characterization. Here, we present the cell-free synthesis of functional human epidermal growth factor receptor and its vIII deletion mutant in a microsome-containing system derived from cultured Sf21 cells. We provide evidence for embedment of cell-free synthesized receptors into microsomal membranes and asparagine-linked glycosylation. Using the cricket paralysis virus internal ribosome entry site and a repetitive synthesis approach enrichment of receptors inside the microsomal fractions was facilitated thereby providing analytical amounts of functional protein. Receptor tyrosine kinase activation was demonstrated by monitoring receptor phosphorylation. Furthermore, an orthogonal cell-free translation system that provides the site-directed incorporation of p-azido-L-phenylalanine is characterized and applied to investigate receptor dimerization in the absence of a ligand by photo-affinity cross-linking. Finally, incorporated azides are used to generate stable covalently linked receptor dimers by strain-promoted cycloaddition using a novel linker system. PMID:27670253

  15. Antihuman epidermal growth factor receptor