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Sample records for growth factor-b receptors

  1. Association assessment of platelet derived growth factor B gene ...

    African Journals Online (AJOL)

    Shayesteh Rezayani

    2017-04-21

    Apr 21, 2017 ... Background: Coronary artery disease (CAD) is the most frequent cause of morbidity and mortality in the world and it is known as a multifactorial disorder which is influenced by both genetic and environmental factors. Based on different assays, the platelet derived growth factor B (PDGF-B) gene is shown to ...

  2. Association assessment of platelet derived growth factor B gene ...

    African Journals Online (AJOL)

    Background: Coronary artery disease (CAD) is the most frequent cause of morbidity and mortality in the world and it is known as a multifactorial disorder which is influenced by both genetic and environmental factors. Based on different assays, the platelet derived growth factor B (PDGF-B) gene is shown to be amongst the ...

  3. serum transforming growth factor b1 and prostate

    African Journals Online (AJOL)

    rum marker for prostate cancer, its low speci- ficity for the detection of prostate cancer, es- pecially in the grey zone of PSA, is a problem1. Therefore, more effective tumor markers for prostate cancer are being sought. A potential candidate marker is the transforming growth factor beta (TGF-B). TGF-l31 has gained con-.

  4. Placenta growth factor and vascular endothelial growth factor B expression in the hypoxic lung

    LENUS (Irish Health Repository)

    Sands, Michelle

    2011-01-25

    Abstract Background Chronic alveolar hypoxia, due to residence at high altitude or chronic obstructive lung diseases, leads to pulmonary hypertension, which may be further complicated by right heart failure, increasing morbidity and mortality. In the non-diseased lung, angiogenesis occurs in chronic hypoxia and may act in a protective, adaptive manner. To date, little is known about the behaviour of individual vascular endothelial growth factor (VEGF) family ligands in hypoxia-induced pulmonary angiogenesis. The aim of this study was to examine the expression of placenta growth factor (PlGF) and VEGFB during the development of hypoxic pulmonary angiogenesis and their functional effects on the pulmonary endothelium. Methods Male Sprague Dawley rats were exposed to conditions of normoxia (21% O2) or hypoxia (10% O2) for 1-21 days. Stereological analysis of vascular structure, real-time PCR analysis of vascular endothelial growth factor A (VEGFA), VEGFB, placenta growth factor (PlGF), VEGF receptor 1 (VEGFR1) and VEGFR2, immunohistochemistry and western blots were completed. The effects of VEGF ligands on human pulmonary microvascular endothelial cells were determined using a wound-healing assay. Results Typical vascular remodelling and angiogenesis were observed in the hypoxic lung. PlGF and VEGFB mRNA expression were significantly increased in the hypoxic lung. Immunohistochemical analysis showed reduced expression of VEGFB protein in hypoxia although PlGF protein was unchanged. The expression of VEGFA mRNA and protein was unchanged. In vitro PlGF at high concentration mimicked the wound-healing actions of VEGFA on pulmonary microvascular endothelial monolayers. Low concentrations of PlGF potentiated the wound-healing actions of VEGFA while higher concentrations of PlGF were without this effect. VEGFB inhibited the wound-healing actions of VEGFA while VEGFB and PlGF together were mutually antagonistic. Conclusions VEGFB and PlGF can either inhibit or potentiate the

  5. Placenta growth factor and vascular endothelial growth factor B expression in the hypoxic lung

    Directory of Open Access Journals (Sweden)

    McLoughlin Paul

    2011-01-01

    Full Text Available Abstract Background Chronic alveolar hypoxia, due to residence at high altitude or chronic obstructive lung diseases, leads to pulmonary hypertension, which may be further complicated by right heart failure, increasing morbidity and mortality. In the non-diseased lung, angiogenesis occurs in chronic hypoxia and may act in a protective, adaptive manner. To date, little is known about the behaviour of individual vascular endothelial growth factor (VEGF family ligands in hypoxia-induced pulmonary angiogenesis. The aim of this study was to examine the expression of placenta growth factor (PlGF and VEGFB during the development of hypoxic pulmonary angiogenesis and their functional effects on the pulmonary endothelium. Methods Male Sprague Dawley rats were exposed to conditions of normoxia (21% O2 or hypoxia (10% O2 for 1-21 days. Stereological analysis of vascular structure, real-time PCR analysis of vascular endothelial growth factor A (VEGFA, VEGFB, placenta growth factor (PlGF, VEGF receptor 1 (VEGFR1 and VEGFR2, immunohistochemistry and western blots were completed. The effects of VEGF ligands on human pulmonary microvascular endothelial cells were determined using a wound-healing assay. Results Typical vascular remodelling and angiogenesis were observed in the hypoxic lung. PlGF and VEGFB mRNA expression were significantly increased in the hypoxic lung. Immunohistochemical analysis showed reduced expression of VEGFB protein in hypoxia although PlGF protein was unchanged. The expression of VEGFA mRNA and protein was unchanged. In vitro PlGF at high concentration mimicked the wound-healing actions of VEGFA on pulmonary microvascular endothelial monolayers. Low concentrations of PlGF potentiated the wound-healing actions of VEGFA while higher concentrations of PlGF were without this effect. VEGFB inhibited the wound-healing actions of VEGFA while VEGFB and PlGF together were mutually antagonistic. Conclusions VEGFB and PlGF can either inhibit or

  6. [The process of heme synthesis in bone marrow mesenchymal stem cells cultured under fibroblast growth factor bFGF and hypoxic conditions].

    Science.gov (United States)

    Poleshko, A G; Lobanok, E S; Mezhevikina, L M; Fesenko, E E; Volotkovskiĭ, I D

    2014-01-01

    It was demonstrated that fibroblast growth factor bFGF influences the process of heme synthesis, the proliferation activity and viability of bone marrow mesenchymal stem cells in culture under hypoxic conditions. The addition of fibroblast growth factor bFGF (7 ng/ml) to the medium under above conditions led to the accumulation of aminolevulinic acid--an early porphyrin and heme precursor, an increase in CD 71 expression--a transferrin receptor, and also a decrease in porphyrin pigments and heme contents--a late precursor and end products of heme synthesis, respectively. It was found that cultivation of the cells under hypoxic conditions and bFGF is an optimum to maintain high viability and proliferation capacity of the mesenchymal stem cells.

  7. Clinical efficacy of basic fibroblast growth factor (bFGF) for diabetic ulcer.

    Science.gov (United States)

    UCHI, Hiroshi; IGARASHI, Atsuyuki; URABE, Kazunori; KOGA, Tetsuya; NAKAYAMA, Juichiro; KAWAMORI, Ryuzo; TAMAKI, Kunihiko; HIRAKATA, Hideki; OHURA, Takehiko; FURUE, Masutaka

    2009-01-01

    Basic fibroblast growth factor (bFGF) has been shown to promote wound healing. The present trial evaluated the clinical efficacy of bFGF for diabetic ulcer, a type of refractory skin ulcer, and the dose-response relationship. This was designed as a randomized, double-blind, dose-ranging, placebo-controlled trial. A total of 150 patients with non-ischaemic diabetic ulcers measuring 900 mm2 or less were randomized into a placebo group (n = 51), a 0.001% bFGF group (n = 49) and a 0.01% bFGF group (n = 50), and 148 of these patients received treatment for 8 weeks or less. The efficacy evaluation was carried out on 139 patients who met the protocol in this trial. The primary outcome was the percentage of patients showing 75% or greater reductions in the area of ulcer. The area of ulcer decreased by 75% or more in 57.5% (27/47), 72.3% (34/47), and 82.2% (37/45) in the placebo, 0.001% bFGF and 0.01% bFGF groups, respectively, and differences were significant between the 0.01% bFGF and placebo groups (p = 0.025). The cure rate was 46.8% (22/47), 57.4% (27/47), and 66.7% (30/45) in the placebo, 0.001% bFGF and 0.01% bFGF groups, respectively. The findings obtained in this trial showed wound healing accelerating effects of bFGF on diabetic ulcers.

  8. Increased susceptibility to atrial fibrillation secondary to atrial fibrosis in transgenic goats expressing transforming growth factor - B1

    Science.gov (United States)

    Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia in people with significant morbidity and mortality. There is a strong association between atrial fibrosis and AF. Transforming growth factor B1 (TGF-B1) is an essential mediator of atrial fibrosis in animal models and human pat...

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

    DEFF Research Database (Denmark)

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

    2005-01-01

    Human epidermal growth factor (hEGF) and basic fibroblast growth factor (bFGF) influence critical characteristics of chondrocytes. The effects on metabolism and differentiation were evaluated following transfection using specific plasmids coding for both cytokines. Chondrocytes were isolated from...

  10. Genomic growth hormone, growth hormone receptor and ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-07-20

    Jul 20, 2009 ... Genomic growth hormone, growth hormone receptor and transforming growth factor β-3 gene polymorphism in breeder hens of Mazandaran native fowls. Babak Enayati and Ghodrat Rahimi-Mianji*. Laboratory for Molecular Genetics and Animal Biotechnology, Department of Animal Sciences, Faculty of ...

  11. Peroxisome proliferator-activated receptor gamma recruits the positive transcription elongation factor b complex to activate transcription and promote adipogenesis

    DEFF Research Database (Denmark)

    Iankova, Irena; Petersen, Rasmus K; Annicotte, Jean-Sébastien

    2006-01-01

    Positive transcription elongation factor b (P-TEFb) phosphorylates the C-terminal domain of RNA polymerase II, facilitating transcriptional elongation. In addition to its participation in general transcription, P-TEFb is recruited to specific promoters by some transcription factors such as c-Myc...

  12. Comparison of human dermal fibroblasts (HDFs) growth rate in culture media supplemented with or without basic fibroblast growth factor (bFGF).

    Science.gov (United States)

    Abdian, Narges; Ghasemi-Dehkordi, Payam; Hashemzadeh-Chaleshtori, Morteza; Ganji-Arjenaki, Mahbobe; Doosti, Abbas; Amiri, Beheshteh

    2015-12-01

    Basic fibroblast growth factor (bFGF or FGF-2) is a member of the FGF family secreted by different kinds of cells like HDFs and it is an important nutritional factor for cell growth and differentiation. The HDFs release bFGF in culture media at very low. The present study aims to investigate the HDFs growth rate in culture media supplemented either with or without bFGF. In brief, HDFs were isolated from human foreskin sample and were cultured in vitro in media containing bFGF and lack of this factor. The cells growth rate was calculated by trypan blue. The karyotyping was performed using G-banding to investigate the chromosomal abnormality of HDFs in both groups. Total RNA of each groups were extracted and cDNA samples were synthesized then, real-time Q-PCR was used to measure the expression level of p27kip1 and cyclin D1 genes normalized to internal control gene (GAPDH). The karyotype analysis showed that HDFs cultured in media or without bFGF had normal karyotype (46 chromosomes, XY) and chromosomal abnormalities were not observed. The cell growth rates in both groups were normal with proliferated exponentially but the slope of growth curve in HDFs cultured in media containing bFGF was increased. Karyotyp test showed that bFGF does not affect on cytogenetic stability of cells. The survey of p27kip1 and cyclin D1 genes by real-time Q-PCR showed that the expression level of these genes were up-regulated when adding bFGF in culture media (p culture media with growth factor like bFGF could enhance the proliferation and differentiation capacity of cells and improve cells growth rate. Similarly, fibroblast growth factors did not induce any chromosomal abnormality in cells. Furthermore, in HDFs cultured in bFGF supplemented media, the p27kip1 and cyclin D1 genes were up-regulated and suggesting an important role for bFGF in cell-cycle regulation and progression and fibroblast division stimulation. It also suggests that the effects of bFGF on different cell types with

  13. Experimental data for insulin-like growth factor-1 (IGF-1) and basic fibroblast growth factor (bFGF) in prevention of radiation myelopathy

    International Nuclear Information System (INIS)

    Nieder, C.; Price, R.E.; Rivera, B.; Andratschke, N.; Kian Ang, K.

    2002-01-01

    Background: Current models of radiation myelopathy provide a rationale for growth factor-based prevention strategies. Thus, we tested whether insulin-like growth factor-1 (IGF-1) and basic fibroblast growth factor (bFGF) alone or in combination modulate radiation tolerance of the rat cervical spinal cord. Materials and Methods: The cervical spinal cord of 68 adult Fisher F344 rats received a total dose of 30-36 Gy, given as a single fraction of 16 Gy followed by a second radiation dose of 14-20 Gy. Continuous intrathecal infusion of bFGF (44 rats) or saline (24 rats) into the cisterna magna was given concomitantly. A further experiment included 14 additional rats which were treated with subcutaneous injection of IGF-1 parallel to irradiation with a total dose of 34 Gy or 36 Gy. 20 rats received combined treatment, i.e. intrathecal infusion of bFGF plus subcutaneous injection of IGF-1, starting 24 hours before irradiation (total dose 33 Gy or 36 Gy) for a total of 4 days. Animals were followed until myelopathy developed or for a maximum of 12 months. Histopathologic examinations were performed post mortem. Results: Treatment with bFGF alone or IGF-1 alone increased the median time to myelopathy significantly. In the 36-Gy group, after combination treatment a comparable prolongation of latency was seen. Moreover, rats treated with 33 Gy and combined bFGF plus IGF-1 showed a significantly reduced risk of myelopathy, too (p = 0.0015). (orig.) [de

  14. The impact of hyperbaric oxygen therapy on serological values of vascular endothelial growth factor (VEGF and basic fibroblast growth factor (bFGF

    Directory of Open Access Journals (Sweden)

    Ziebura Thomas

    2010-12-01

    Full Text Available Abstract Background Hyperbaric oxygen (HBO therapy is an effective adjunct treatment for ischemic disorders such as chronic infection or chronic wounds. It combines hyperoxic effects with the stimulating potential of post-therapeutic reactive hypoxia. As its crucial effects, stimulation of fibroblast growth, induction of collagen synthesis and the initiation of angiogenesis are discussed. Angiogenesis is a multistage process resulting in the growth of blood vessels. It includes degradation of extracellular matrix, proliferation and migration of different cell populations and finally formation of new vessel structures. This complex chain of procedures is orchestrated by different cytokines and growth factors. Crucial mediators of angiogenesis are basic fibroblast growth factor (bFGF and vascular endothelial growth factor (VEGF; their in-vivo function is still not fully understood. Methods Forty-three patients suffering from sudden sensorineural hearing loss or tinnitus were treated with HBO. The therapy included 10 sessions of 90 minutes each, one session a day. Serological levels of bFGF and VEGF were assessed by enzyme-linked immunosorbent assays performed according to the manufacturer's instructions on day 1, 2, 5 and 10 of HBO therapy and were compared to mean values of the control group, related to the patient's age and sex, and their development observed over the ten days of HBO. Results There was no sex- or age dependency of bFGF observed in the present study, whereas under HBO our results showed a significant mitigation of the bFGF concentration. In the present data, there was no connection between the VEGF concentration and the patients' ages. Women showed significantly higher levels of VEGF. There was no significant change of VEGF concentration or the VEGF/bFGF ratio during HBO. All scored results varied within the range of standard values as described in the current literature. Conclusions A significant effect of HBO on serum

  15. Pathway of Toll-like receptor 7/B cell activating factor/B cell activating factor receptor plays a role in immune thrombocytopenia in vivo.

    Directory of Open Access Journals (Sweden)

    Qing Yang

    Full Text Available Immune thrombocytopenia (ITP is an autoimmune disorder characterized by anti-platelet autoantibody-mediated platelet destruction. Antigen-presenting cell (APC dysfunction is considered to play crucial roles in ITP. However, how APC affects autoreactive B cells in ITP is still unknown. Using a mouse model of immune thrombocytopenia, we demonstrated an increase in levels of TLR7 in splenic mononuclear cells (SMCs. Using both TLR7 agonist and TLR7 silencing lentivirus, we found stimulation of TLR7 decreased platelet counts and increased levels of platelet-associated IgG (PAIgG in ITP mice, which correlates TLR7 with platelet destruction by autoantibodies. Levels of serum BAFF increased significantly in ITP mice and stimulation of TLR7 promoted secretion of BAFF. Among the three BAFF receptors, only BAFF receptor (BAFF-R increased in ITP mice. However, activation of TLR7 showed no effect on the expression of BAFF receptors. These findings indicate that upregulation of TLR7 may augment BAFF secretion by APC and through ligation of BAFF-R promote autoreactive B cell survival and thus anti-platelet autoantibody production. The pathway of TLR7/BAFF/BAFF-R provides us with an explanation of how activation of APC affects autoantibody production by B cells in ITP and thus might provide a reasonable therapeutic strategy for ITP.

  16. Effect of local administration of platelet-derived growth factor B on functional recovery of peripheral nerve regeneration: A sciatic nerve transection model.

    Science.gov (United States)

    Golzadeh, Atefeh; Mohammadi, Rahim

    2016-01-01

    Effects of platelet-derived growth factor B (PDGF-B) on peripheral nerve regeneration was studied using a rat sciatic nerve transection model. Forty-five male, white Wistar rats were divided into three experimental groups (n = 15), randomly: Normal control group (NC), silicon group (SIL), and PDGF-B treated group (SIL/PDGF). In NC group, left sciatic nerve was exposed through a gluteal muscle incision and after homeostasis muscle was sutured. In the SIL group, the left sciatic nerve was exposed in the same way and transected proximal to tibio-peroneal bifurcation leaving a 10-mm gap. Proximal and distal stumps were each inserted into a silicone conduit and filled with 10 μL phosphate buffered solution. In SIL/PDGF group, the silicon conduit was filled with 10 μL PDGF-B (0.5 ng/mL). Each group was subdivided into three subgroups of five and were studied in 4, 8, 12 weeks after surgery. Behavioral testing, sciatic nerve functional study, gastrocnemius muscle mass, and histomorphometric studies showed earlier regeneration of axons in SIL/PDGF than in SIL group (P recovery and may have clinical implications for the surgical management of patients after facial nerve transection.

  17. Safflower Extract and Aceglutamide Injection Promoting Recovery of Peripheral Innervations via Vascular Endothelial Growth Factor-B Signaling in Diabetic Mice.

    Science.gov (United States)

    Li, Dan; Chen, You-Gang; Zhang, Cui-Juan; Tian, Jing; Li, Xia

    2017-12-05

    Safflower extract and aceglutamide (SA) has been used clinically for the treatment of cerebrovascular diseases such as cerebral embolism, hemorrhage, and mental deterioration. This study aimed to investigate the effect and mechanism of SA injection in the recovery of peripheral innervations of diabetic mice. The C57BL/6 male mice were divided into four groups: normal control group (n = 44), diabetic group (n = 44), diabetic + SA group (diabetic mice treated with SA injection, n = 44), and diabetic + SA + vascular endothelial growth factor receptor (VEGFR)1-BL group (diabetic mice treated with SA injection and VEGFR 1 blocking antibody n = 24). The streptozotocin-induced diabetic mice model and injured peripheral nerve mice model were built. The mice with injured peripheral nerves were intraperitonealy administered with SA injection for successive 21 days. The corneal sensitivity, number of corneal nerve fibers, and contents of vascular endothelial growth factor (VEGF)-B and various neurotrophic factors such as nerve growth factor (NGF) and glial cell line-derived neurotrophic factor (GDNF) in corneal tissue of four groups were observed. The diabetic group showed decreased number of corneal nerve fibers, compared with the control group (P = 0.002). And compared with the diabetic group, the diabetic + SA group showed a significant increase in the number of nerve fibers (P = 0.024) and the contents of VEGF-B, NGF, and GDNF in the cornea (all P < 0.05). However, when the diabetic mice were treated with the blocking antibodies specialized for VEGF-B receptor, the neutralization of VEGFR-1 completely abolished the increased expression of NGF and GDNF stimulated by SA injection. SA injection could reduce the nerve injury caused by diabetic peripheral neuropathy, and its protective effect might be associated with the promotion of the expressions of VEGF-B, NGF, and GDNF.

  18. Growth hormone receptor gene expression in puberty.

    Science.gov (United States)

    Pagani, S; Meazza, C; Gertosio, C; Bozzola, E; Bozzola, M

    2015-07-01

    The mechanisms regulating the synergic effect of growth hormone and other hormones during pubertal spurt are not completely clarified. We enrolled 64 females of Caucasian origin and normal height including 22 prepubertal girls, 26 pubertal girls, and 16 adults to evaluate the role of Growth Hormone/Insulin-like growth factor-I axis (GH/IGF-I) during the pubertal period. In these subjects both serum IGF-I and growth hormone binding protein levels, as well as quantitative growth hormone receptor (GHR) gene expression were evaluated in peripheral lymphocytes of all individuals by real-time PCR. Our results showed significantly lower IGF-I levels in women (148±10 ng/ml) and prepubertal girls (166.34±18.85 ng/ml) compared to pubertal girls (441.95±29.42 ng/ml; p<0.0001). Serum GHBP levels were significantly higher in prepubertal (127.02±20.76 ng/ml) compared to pubertal girls (16.63±2.97 ng/ml; p=0.0001) and adult women (19.95±6.65 ng/ml; p=0.0003). We also found higher GHR gene expression levels in pubertal girls [174.73±80.22 ag (growth hormone receptor)/5×10(5) ag (glyceraldehyde 3-phosphate dehydrogenase)] compared with other groups of subjects [women: 42.52±7.66 ag (growth hormone receptor)/5×10(5) ag (glyceraldehyde 3-phosphate dehydrogenase); prepubertal girls: 58.45±0.18.12 ag (growth hormone receptor)/5×10(5) ag (glyceraldehyde 3-phosphate dehydrogenase)], but the difference did not reach statistical significance. These results suggest that sexual hormones could positively influence GHR action, during the pubertal period, in a dual mode, that is, increasing GHR mRNA production and reducing GHR cleavage leading to GHBP variations. © Georg Thieme Verlag KG Stuttgart · New York.

  19. Epidermal growth factor receptor signaling in tissue

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    African Journals Online (AJOL)

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

  1. Molecular analysis of the nerve growth factor receptor

    International Nuclear Information System (INIS)

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

    1988-01-01

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

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

    NARCIS (Netherlands)

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

    1990-01-01

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

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

    Science.gov (United States)

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

    2013-01-01

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

  4. COMPARATIVE STUDY OF TOPICAL MOMETASONE FUROATE 0.1%, TOPICAL 0.03% TACROLIMUS, TOPICAL BASIC FIBROBLAST GROWTH FACTOR (bFGF IN CHILDHOOD VITILIGO

    Directory of Open Access Journals (Sweden)

    Kavitha S. B

    2017-08-01

    Full Text Available BACKGROUND Vitiligo, the commonest of all pigmentary disorders, is an idiopathic, acquired cutaneous achromia, characterised by circumscribed, chalky white macules. It may also involve the pigment epithelium of the eyes, the inner ear and the leptomeninges. Although, vitiligo can begin at any age, it develops before the age of 20 years in 50% of the patients and before the age of 10 years in 25% of patients. MATERIALS AND METHODS The study was conducted for a period of one year with 6 months active intervention. A group of 60 consecutive children attending the outpatient Department of Dermatology were included in this study. The same patients were acting as controls. RESULTS Grade 4 response was seen in 12 cases (60% who were on mometasone (VV-20%, focal-30%, segmental-10%, in 10 cases (50% on tacrolimus (VV-20%, focal-30% and in 4 cases (20% on bFGF (focal. Lesions on the face and neck showed grade 4 response in 16 cases (mometasone-8, tacrolimus-6 and bFGF-2, extremities in 6 cases. On the whole grade, 4 response was observed more with mometasone (60% followed by tacrolimus (50%. Grade 3 response was observed with bFGF (30%. CONCLUSION Topical mometasone was very effective among the 3 drugs used in childhood vitiligo showing grade 4 repigmentation in all types of vitiligo except mucosal vitiligo. Tacrolimus proved almost as effective as mometasone to restore skin colour in lesions of vitiligo in children. Because it does not produce atrophy or other adverse effects, tacrolimus may be very useful for younger patients, and for sensitive areas of the skin such as eyelids, it should be considered in other skin disorders currently treated with topical steroids for prolonged periods. Topical basic fibroblast growth factor though less effective than mometasone and tacrolimus, but can be tried as initial therapy in resistant cases such as segmental vitiligo as initial therapy of small vitiligo patches when physicians may not like to initiate high risk

  5. Novel Drosophila receptor that binds multiple growth factors

    International Nuclear Information System (INIS)

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

    1986-01-01

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

  6. Epiphyseal growth plate growth hormone receptor signaling is decreased in chronic kidney disease-related growth retardation.

    Science.gov (United States)

    Troib, Ariel; Landau, Daniel; Kachko, Leonid; Rabkin, Ralph; Segev, Yael

    2013-11-01

    Linear growth retardation in children with chronic kidney disease (CKD) has been ascribed to insensitivity to growth hormone. This resistance state has been attributed to impaired growth hormone signaling through the JAK2/STAT5 pathway in liver and skeletal muscle leading to reduced insulin-like growth factor-I (IGF-I). Here we determine whether systemic and growth plate alterations in growth hormone signaling contribute to CKD-induced linear growth retardation using partially nephrectomized and pair-fed control 20-day-old rats. Serum growth hormone did not change in rats with CKD, yet serum IGF-I levels were decreased and growth retarded. The tibial growth plate hypertrophic zone was wider and vascularization at the primary ossification center was reduced in CKD. This was associated with a decrease in growth plate vascular endothelial growth factor (VEGF) mRNA and immunostainable VEGF and IGF-I levels. Growth plate growth hormone receptor and STAT5 protein levels were unchanged, while JAK2 was reduced. Despite comparable growth hormone and growth hormone receptor levels in CKD and control rats, relative STAT5 phosphorylation was significantly depressed in CKD. Of note, the mRNA of SOCS2, an inhibitor of growth hormone signaling, was increased. Thus, linear growth impairment in CKD can in part be explained by impaired long bone growth plate growth hormone receptor signaling through the JAK2/STAT5 pathway, an abnormality that may be caused by an increase in SOCS2 expression.

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

    Science.gov (United States)

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

    2010-01-01

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

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

    Science.gov (United States)

    Tan, Y; Chiow, K H; Huang, D; Wong, S H

    2010-04-01

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

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

    International Nuclear Information System (INIS)

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

    1988-01-01

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

  10. Astrocyte Mitogen Inhibitor Related to Epidermal Growth Factor Receptor

    Science.gov (United States)

    Nieto-Sampedro, Manuel

    1988-06-01

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

  11. Vascular endothelial growth factor ( VEGF ) receptor expression ...

    African Journals Online (AJOL)

    Background: Colorectal carcinoma (CRC) is the seventh-most common malignancy and is the main cause of death in Iraq. The incidence of this cancer has increased sharply after the invasion of Iraq in 2003. Aim: To estimate immunohistochemical expression of vascular endothelial growth factor (VEGF) in CRC in relation ...

  12. Growth hormone receptor deficiency (Laron syndrome) in black ...

    African Journals Online (AJOL)

    Non-Caucasians with growth honnone receptor (GHR) deficiency/Lamn syndrome among the .... 4,3 cm (-2,4 SOS for bone age 8,5 years at age 12); the girl's height at age 7 years was 77,5 cm (-8,0 SOS, height ... of serum incubated with '25I-labelled human growth hormone and expressed as relative specific binding ...

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

    NARCIS (Netherlands)

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

    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

  14. Growth hormone receptor deficiency (Laron syndrome) in black ...

    African Journals Online (AJOL)

    Non-Caucasians with growth honnone receptor (GHR) deficiency/Lamn syndrome among the approximately 180 recognised cases are rare, and include a Japanese and 3 African Americans. Black African siblings, a brother and a sister seen initially at 11 years 9 months and 5 years 6 months of age respectively were -7,4 ...

  15. Epidermal growth factor receptor: Target for delivery and silencing

    NARCIS (Netherlands)

    Santos Oliveira, S.|info:eu-repo/dai/nl/304841455

    2008-01-01

    Epidermal growth factor receptor in cancer therapy Recently, cancer research has been able to identify molecular targets that are specific for (or highly expressed by) cancer cells. These molecular targets serve as models for the development of rationally designed anticancer drugs that target

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

    DEFF Research Database (Denmark)

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

    1983-01-01

    markedly with age. This decrease in receptor number is similar in trend to the known drop in basal cell [3H]thymidine labelling index which occurs over the same time period. The data suggest that the distribution of EGF receptors and EGF cell surface receptor number in skin are important in the spatial......, and keratinisation when injected into neonatal mice (S. Cohen and G.A. Elliott, 1963, J. Invest. Dermatol, 40, 1-5). We have determined the distribution of the available receptors for epidermal growth factor in rat skin using autoradiography following incubation of explants with 125I-labelled mouse EGF. EGF...... receptors are detected on the epithelial cells overlying the basement membranes of the epidermis, sebaceous gland, and regions of the hair follicle all of which have proliferative capacity. In marked contrast, tissues which have started to differentiate and lost their growth potential, carry either...

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

    Directory of Open Access Journals (Sweden)

    Jena J Steinle

    2010-06-01

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

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

    NARCIS (Netherlands)

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

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

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

    NARCIS (Netherlands)

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

    2013-01-01

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

  20. Epidermal growth factor receptor expression in urinary bladder cancer

    Directory of Open Access Journals (Sweden)

    Dayalu S.L. Naik

    2011-01-01

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

  1. Delineation of atypical insulin receptors from classical insulin and type I insulin-like growth factor receptors in human placenta.

    OpenAIRE

    Jonas, H A; Cox, A J; Harrison, L C

    1989-01-01

    Insulin-like growth factor (IGF)-binding sites copurifying with human placental insulin receptors during insulin-affinity chromatography consist of two immunologically distinct populations. One reacts with monoclonal antibody alpha IR-3, but not with antibodies to the insulin receptor, and represents Type I IGF receptors; the other reacts only with antibodies to the insulin receptor and is precipitated with a polyclonal receptor antibody (B-10) after labelling with 125I-multiplication-stimula...

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

    International Nuclear Information System (INIS)

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

    1988-01-01

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

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

    NARCIS (Netherlands)

    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

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

    Directory of Open Access Journals (Sweden)

    Ahmed Nessar

    2008-01-01

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

  5. Expression of functional growth hormone receptor in a mouse L cell line infected with recombinant vaccinia virus

    NARCIS (Netherlands)

    Strous, G J; van Kerkhof, P; Verheijen, C; Rossen, J W; Liou, W; Slot, J W; Roelen, C A; Schwartz, A L

    The growth hormone receptor is a member of a large family of receptors including the receptors for prolactin and interleukins. Upon binding to one molecule of growth hormone two growth hormone receptor polypeptides dimerize. We have expressed the rabbit growth hormone receptor DNA in transfected

  6. The Growth Hormone Receptor: Mechanism of Receptor Activation, Cell Signaling, and Physiological Aspects

    Directory of Open Access Journals (Sweden)

    Farhad Dehkhoda

    2018-02-01

    Full Text Available The growth hormone receptor (GHR, although most well known for regulating growth, has many other important biological functions including regulating metabolism and controlling physiological processes related to the hepatobiliary, cardiovascular, renal, gastrointestinal, and reproductive systems. In addition, growth hormone signaling is an important regulator of aging and plays a significant role in cancer development. Growth hormone activates the Janus kinase (JAK–signal transducer and activator of transcription (STAT signaling pathway, and recent studies have provided a new understanding of the mechanism of JAK2 activation by growth hormone binding to its receptor. JAK2 activation is required for growth hormone-mediated activation of STAT1, STAT3, and STAT5, and the negative regulation of JAK–STAT signaling comprises an important step in the control of this signaling pathway. The GHR also activates the Src family kinase signaling pathway independent of JAK2. This review covers the molecular mechanisms of GHR activation and signal transduction as well as the physiological consequences of growth hormone signaling.

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

    DEFF Research Database (Denmark)

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

    1983-01-01

    receptors are detected on the epithelial cells overlying the basement membranes of the epidermis, sebaceous gland, and regions of the hair follicle all of which have proliferative capacity. In marked contrast, tissues which have started to differentiate and lost their growth potential, carry either......Epidermal growth factor (EGF), a low-molecular-weight polypeptide (G. Carpenter and S. Cohen, 1979, Annu. Rev. Biochem. 48, 193-216), stimulates the proliferation and keratinisation of cultured embryonic epidermis (S. Cohen, 1965, Dev. Biol. 12, 394-407) and promotes epidermal growth, thickening......, and keratinisation when injected into neonatal mice (S. Cohen and G.A. Elliott, 1963, J. Invest. Dermatol, 40, 1-5). We have determined the distribution of the available receptors for epidermal growth factor in rat skin using autoradiography following incubation of explants with 125I-labelled mouse EGF. EGF...

  8. Studies on Platelet-Derived Growth Factor Beta-Receptor and Hepatocyte Growth Factor Receptor c-met in Paracrine Interactions in Human Breast Cancer

    Science.gov (United States)

    1996-09-01

    specific expression, and transforming submandibular gland . Growth Factors 1994, 10:145- activity of the mouse met proto-oncogene. Cell Growth 151...Derived Growth Factor Beta-Receptor and Hepatocyte Growth Factor Receptor c-met in Paracrine Interactions in Human Breast Cancer PRINCIPAL INVESTIGATOR...Interactions in Human Breast DAMDI7-94-J-4407 Cancer 6. AUTHOR(S) Bruce E. Elliott, Ph.D. 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) 8. PERFORMING

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

    Science.gov (United States)

    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

  10. Protein-tyrosine phosphatase H1 controls growth hormone receptor signaling and systemic growth.

    Science.gov (United States)

    Pilecka, Iwona; Patrignani, Claudia; Pescini, Rosanna; Curchod, Marie-Laure; Perrin, Dominique; Xue, Yingzi; Yasenchak, Jason; Clark, Ann; Magnone, Maria Chiara; Zaratin, Paola; Valenzuela, David; Rommel, Christian; Hooft van Huijsduijnen, Rob

    2007-11-30

    Several protein-tyrosine phosphatases (PTPs) have been implicated in the control of growth hormone receptor (GHR) signaling, but none have been shown to affect growth in vivo. We have applied a battery of molecular and cellular approaches to test a family-wide panel of PTPs for interference with GHR signaling. Among the subset of PTPs that showed activity in multiple readouts, we selected PTP-H1/PTPN3 for further in vivo studies and found that mice lacking the PTP-H1 catalytic domain show significantly enhanced growth over their wild type littermates. In addition, PTP-H1 mutant animals had enhanced plasma and liver mRNA expression of insulin-like growth factor 1, as well as increased bone density and mineral content. These observations point to a controlling role for PTP-H1 in modulating GHR signaling and systemic growth through insulin-like growth factor 1 secretion.

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

    DEFF Research Database (Denmark)

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

    2012-01-01

    to the extracellular part of EGFR, blocking the binding sites for the EGFR ligands, and intracellular tyrosine kinase inhibitors (TKIs) that block the ATP binding site of the tyrosine kinase domain. Besides an EGFRvIII-targeted vaccine, conjugated anti-EGFR mAbs have been used in different settings to deliver lethal......The epidermal growth factor receptor (EGFR) is over-expressed, as well as mutated, in many types of cancers. In particular, the EGFR variant type III mutant (EGFRvIII) has attracted much attention as it is frequently and exclusively found on many tumor cells, and hence both EGFR and EGFRvIII have...... been proposed as valid targets in many cancer therapy settings. Different strategies have been developed in order to either inhibit EGFR/EGFRvIII activity or to ablate EGFR/EGFRvIII-positive tumor cells. Drugs that inhibit these receptors include monoclonal antibodies (mAbs) that bind...

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

    DEFF Research Database (Denmark)

    Dengjel, Joern; Akimov, Vyacheslav; Blagoev, Blagoy

    2007-01-01

    -out by mass spectrometry-based proteomics has allowed exciting views on the very early events in signal transduction. Activation profiles of regulated phosphorylation sites on epidermal growth factor receptor and downstream signal transducers showed different kinetics within the first ten seconds......Phosphorylation-based signaling events happening within the first minute of receptor stimulation have so far only been analyzed by classical cell biological approaches like live-cell microscopy. The development of a quench flow system with a time resolution of one second coupled to a read...... of stimulation. This new technique opens the perspectives for accurate analysis of rapid cellular processes and will help to establish models describing signal initiation at the plasma membrane....

  13. Ligand Receptor-Mediated Regulation of Growth in Plants.

    Science.gov (United States)

    Haruta, Miyoshi; Sussman, Michael R

    2017-01-01

    Growth and development of multicellular organisms are coordinately regulated by various signaling pathways involving the communication of inter- and intracellular components. To form the appropriate body patterns, cellular growth and development are modulated by either stimulating or inhibiting these pathways. Hormones and second messengers help to mediate the initiation and/or interaction of the various signaling pathways in all complex multicellular eukaryotes. In plants, hormones include small organic molecules, as well as larger peptides and small proteins, which, as in animals, act as ligands and interact with receptor proteins to trigger rapid biochemical changes and induce the intracellular transcriptional and long-term physiological responses. During the past two decades, the availability of genetic and genomic resources in the model plant species, Arabidopsis thaliana, has greatly helped in the discovery of plant hormone receptors and the components of signal transduction pathways and mechanisms used by these immobile but highly complex organisms. Recently, it has been shown that two of the most important plant hormones, auxin and abscisic acid (ABA), act through signaling pathways that have not yet been recognized in animals. For example, auxins stimulate cell elongation by bringing negatively acting transcriptional repressor proteins to the proteasome to be degraded, thus unleashing the gene expression program required for increasing cell size. The "dormancy" inducing hormone, ABA, binds to soluble receptor proteins and inhibits a specific class of protein phosphatases (PP2C), which activates phosphorylation signaling leading to transcriptional changes needed for the desiccation of the seeds prior to entering dormancy. While these two hormone receptors have no known animal counterparts, there are also many similarities between animal and plant signaling pathways. For example, in plants, the largest single gene family in the genome is the protein kinase

  14. Growth hormone-dependent phosphorylation of tyrosine 333 and/or 338 of the growth hormone receptor

    DEFF Research Database (Denmark)

    VanderKuur, J A; Wang, X; Zhang, L

    1995-01-01

    Many signaling pathways initiated by ligands that activate receptor tyrosine kinases have been shown to involve the binding of SH2 domain-containing proteins to specific phosphorylated tyrosines in the receptor. Although the receptor for growth hormone (GH) does not contain intrinsic tyrosine...

  15. Ghrelin and the growth hormone secretagogue receptor in growth and development.

    Science.gov (United States)

    Chanoine, J-P; De Waele, K; Walia, P

    2009-04-01

    The pancreas is a major source of ghrelin in the perinatal period, whereas gastric production progressively increases after birth. Loss of function of the genes for ghrelin or for the constitutively activated growth hormone secretagogue receptor (GHSR) does not affect birth weight and early postnatal growth. However, ghrl(-/-) or ghsr(-/-) mice fed a high fat diet starting soon after weaning are resistant to diet-induced obesity, suggesting that ghrelin affects the maturation of the metabolic axes involved in energy balance. In addition, animal and human studies suggest that GHSR plays a physiological role in linear growth. In mice, absence of the GHSR gene is associated with lower insulin-like growth factor 1 concentrations and lower body mass in adult animals, independently of food intake. In humans, a mutation of the GHSR gene that impairs the constitutive activity of the receptor was found in two families with short stature. Administration of acylated ghrelin to rat pups directly does not affect weight gain. In contrast, administration of ghrelin to pregnant or lactating rats results in greater fetal weight and postnatal weight gain, respectively, suggesting that maternal ghrelin may stimulate perinatal growth. These data point toward a physiological role for ghrelin and GHSR in growth and/or in the maturation of hormonal systems involved in the regulation of energy balance.

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

    International Nuclear Information System (INIS)

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

    2005-01-01

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

  17. The F-BAR protein PACSIN2 regulates epidermal growth factor receptor internalization

    NARCIS (Netherlands)

    B.J. de Kreuk (Bart-Jan); E.C. Anthony (Eloise); D. Geertss (Dirk); P.L. Hordijk (Peter )

    2012-01-01

    textabstractSignaling 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

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

    Science.gov (United States)

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

    2017-05-01

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

  19. Growth hormone action in rat insulinoma cells expressing truncated growth hormone receptors

    DEFF Research Database (Denmark)

    Møldrup, Annette; Allevato, G; Dyrberg, Thomas

    1991-01-01

    Transfection of the insulin-producing rat islet tumor cell line RIN-5AH with a full length cDNA of the rat hepatic growth hormone (GH) receptor (GH-R1-638) augments the GH-responsive insulin synthesis in these cells. Using this functional system we analyzed the effect of COOH-terminal truncation...... of the GH receptor. Two mutated cDNAs encoding truncated GH receptors, GH-R1-294 and GH-R1-454, respectively, were generated by site-directed mutagenesis and transfected into the RIN cells. Both receptor mutants were expressed on the cell surface and displayed normal GH binding affinity. Whereas GH-R1......-638 had a molecular mass of about 110 kDa, GH-R1-294 and GH-R1-454 showed molecular masses of 49 and 80 kDa, respectively. Cells expressing GH-R1-454 internalized GH to a similar extent as cells transfected with the full length receptor and the parent cell line, but GH-R1-294-expressing cells showed...

  20. Growth hormone receptors in cultured adipocytes: a model to study receptor regulation.

    Science.gov (United States)

    Roupas, P; Herington, A C

    1986-09-01

    Acutely isolated rat adipocytes have been maintained in primary culture for several days and the effects of culture on the kinetics of 125I-human growth hormone (hGH) binding to adipocytes have been determined. A marked increase (500-1000%) in specific binding of 125I-hGH was observed over the first 3 days of culture--acutely isolated adipocytes (5.5 +/- 1.4%, mean +/- SE, n = 47) compared to 3-day cultured adipocytes (48 +/- 7%, mean +/- SE, n = 8). Specific binding of 125I-hGH to both acutely isolated and cultured adipocytes was dependent on incubation time and temperature (equilibrium being reached in 1 h at 37 degrees C and 2 h at 22 degrees C). Binding was reversible (t1/2 approximately 1.5 h). Scatchard analysis revealed linear plots and showed that the increase in binding during culture was due to an increase in the number of receptors per cell (approximately 20 000 to approximately 170 000) with little or no change in binding affinity (Ka approximately 1 X 10(9) M-1). Cycloheximide inhibited the increase in binding sites during culture suggesting a requirement for de novo protein synthesis. Addition of unlabelled hGH to the culture medium resulted in a marked down-regulation of the GH receptor by 2 days. The GH-induced decrease in receptor number was to due to receptor occupancy by exogenously added GH. The studies to date indicate that the cultured rat adipocyte should provide a useful model for a comprehensive study of the cellular mechanisms and dynamics of GH receptor regulation.

  1. P2X7R suppression promotes glioma growth through epidermal growth factor receptor signal pathway.

    Science.gov (United States)

    Fang, Jingqin; Chen, Xiao; Zhang, Letian; Chen, Jinhua; Liang, Yi; Li, Xue; Xiang, Jianbo; Wang, Lili; Guo, Guangkuo; Zhang, Bo; Zhang, Weiguo

    2013-06-01

    P2X7 receptor (P2X7R) has been shown to mediate an anticancer effect via apoptosis in different types of cancer. However, whether P2X7R exerts a promoting or suppressive effect on brain glioma is still a controversial issue and its underlying mechanism remains unknown. We showed here that P2X7R suppression exerted a pro-growth effect on glioma through directly promoting cells proliferation and pro-angiogenesis, which was associated with epidermal growth factor receptor (EGFR) signaling. The P2X7R was markedly downregulated by cells exposure to the P2X7R antagonist, brilliant blue G (BBG), moreover, the cells proliferation was enhanced in a dose-dependent manner and the expression of EGFR or p-EGFR protein was significantly upregulated. By constructing C6 cells with reduced expression of P2X7R using shRNA, we also demonstrated strong upregulation in cells proliferation and EGFR/p-EGFR expression. However, this effect of BBG was reversed in the presence of gefitinib or suramin. Magnetic resonance imaging and computed tomography perfusion showed that the BBG or P2X7R shRNA promoted the tumor growth by about 40% and 50%, respectively, and significantly increased angiogenesis. Nissl and Ki-67 staining also confirmed that BBG or P2X7R shRNA notably increased the tumor growth. More importantly, either BBG or P2X7R shRNA could markedly upregulated the expression of EGFR, p-EGFR, HIF-1α and VEGF in glioma cells. In conclusion, P2X7R suppression exerts a promoting effect on glioma growth, which is likely to be related to upregulated EGFR, HIF-1α and VEGF expression. These findings provide important clues to the molecular basis of anticancer effect of targeting purinergic receptors. Copyright © 2013 Elsevier Ltd. All rights reserved.

  2. Establishment of canine hemangiosarcoma xenograft models expressing endothelial growth factors, their receptors, and angiogenesis-associated homeobox genes

    International Nuclear Information System (INIS)

    Kodama, Atsushi; Yanai, Tokuma; Sakai, Hiroki; Matsuura, Satoko; Murakami, Mami; Murai, Atsuko; Mori, Takashi; Maruo, Kouji; Kimura, Tohru; Masegi, Toshiaki

    2009-01-01

    Human hemangiosarcoma (HSA) tends to have a poor prognosis; its tumorigenesis has not been elucidated, as there is a dearth of HSA clinical specimens and no experimental model for HSA. However, the incidence of spontaneous HSA is relatively high in canines; therefore, canine HSA has been useful in the study of human HSA. Recently, the production of angiogenic growth factors and their receptors in human and canine HSA has been reported. Moreover, the growth-factor environment of HSA is very similar to that of pathophysiological angiogenesis, which some homeobox genes regulate in the transcription of angiogenic molecules. In the present study, we established 6 xenograft canine HSA tumors and detected the expression of growth factors, their receptors, and angiogenic homeobox genes. Six primary canine HSAs were xenografted to nude mice subcutaneously and serially transplanted. Subsequently, the expressions of vascular endothelial growth factor (VEGF)-A, basic fibroblast growth factors (bFGF), flt-1 and flk-1 (receptors of VEGF-A), FGFR-1, and angiogenic homeobox genes HoxA9, HoxB3, HoxB7, HoxD3, Pbx1, and Meis1 were investigated in original and xenograft tumors by histopathology, immunostaining, and reverse transcription polymerase chain reaction (RT-PCR), using canine-specific primer sets. Histopathologically, xenograft tumors comprised a proliferation of neoplastic cells that were varied in shape, from spindle-shaped and polygonal to ovoid; some vascular-like structures and vascular clefts of channels were observed, similar to those in the original tumors. The expression of endothelial markers (CD31 and vWF) was detected in xenograft tumors by immunohistochemistry and RT-PCR. Moreover, the expression of VEGF-A, bFGF, flt-1, flk-1, FGFR-1, HoxA9, HoxB3, HoxB7, HoxD3, Pbx1, and Meis1 was detected in xenograft tumors. Interestingly, expressions of bFGF tended to be higher in 3 of the xenograft HSA tumors than in the other tumors. We established 6 xenograft canine HSA

  3. Establishment of canine hemangiosarcoma xenograft models expressing endothelial growth factors, their receptors, and angiogenesis-associated homeobox genes

    Directory of Open Access Journals (Sweden)

    Maruo Kouji

    2009-10-01

    Full Text Available Abstract Background Human hemangiosarcoma (HSA tends to have a poor prognosis; its tumorigenesis has not been elucidated, as there is a dearth of HSA clinical specimens and no experimental model for HSA. However, the incidence of spontaneous HSA is relatively high in canines; therefore, canine HSA has been useful in the study of human HSA. Recently, the production of angiogenic growth factors and their receptors in human and canine HSA has been reported. Moreover, the growth-factor environment of HSA is very similar to that of pathophysiological angiogenesis, which some homeobox genes regulate in the transcription of angiogenic molecules. In the present study, we established 6 xenograft canine HSA tumors and detected the expression of growth factors, their receptors, and angiogenic homeobox genes. Methods Six primary canine HSAs were xenografted to nude mice subcutaneously and serially transplanted. Subsequently, the expressions of vascular endothelial growth factor (VEGF-A, basic fibroblast growth factors (bFGF, flt-1 and flk-1 (receptors of VEGF-A, FGFR-1, and angiogenic homeobox genes HoxA9, HoxB3, HoxB7, HoxD3, Pbx1, and Meis1 were investigated in original and xenograft tumors by histopathology, immunostaining, and reverse transcription polymerase chain reaction (RT-PCR, using canine-specific primer sets. Results Histopathologically, xenograft tumors comprised a proliferation of neoplastic cells that were varied in shape, from spindle-shaped and polygonal to ovoid; some vascular-like structures and vascular clefts of channels were observed, similar to those in the original tumors. The expression of endothelial markers (CD31 and vWF was detected in xenograft tumors by immunohistochemistry and RT-PCR. Moreover, the expression of VEGF-A, bFGF, flt-1, flk-1, FGFR-1, HoxA9, HoxB3, HoxB7, HoxD3, Pbx1, and Meis1 was detected in xenograft tumors. Interestingly, expressions of bFGF tended to be higher in 3 of the xenograft HSA tumors than in the

  4. Establishment of canine hemangiosarcoma xenograft models expressing endothelial growth factors, their receptors, and angiogenesis-associated homeobox genes

    Science.gov (United States)

    2009-01-01

    Background Human hemangiosarcoma (HSA) tends to have a poor prognosis; its tumorigenesis has not been elucidated, as there is a dearth of HSA clinical specimens and no experimental model for HSA. However, the incidence of spontaneous HSA is relatively high in canines; therefore, canine HSA has been useful in the study of human HSA. Recently, the production of angiogenic growth factors and their receptors in human and canine HSA has been reported. Moreover, the growth-factor environment of HSA is very similar to that of pathophysiological angiogenesis, which some homeobox genes regulate in the transcription of angiogenic molecules. In the present study, we established 6 xenograft canine HSA tumors and detected the expression of growth factors, their receptors, and angiogenic homeobox genes. Methods Six primary canine HSAs were xenografted to nude mice subcutaneously and serially transplanted. Subsequently, the expressions of vascular endothelial growth factor (VEGF)-A, basic fibroblast growth factors (bFGF), flt-1 and flk-1 (receptors of VEGF-A), FGFR-1, and angiogenic homeobox genes HoxA9, HoxB3, HoxB7, HoxD3, Pbx1, and Meis1 were investigated in original and xenograft tumors by histopathology, immunostaining, and reverse transcription polymerase chain reaction (RT-PCR), using canine-specific primer sets. Results Histopathologically, xenograft tumors comprised a proliferation of neoplastic cells that were varied in shape, from spindle-shaped and polygonal to ovoid; some vascular-like structures and vascular clefts of channels were observed, similar to those in the original tumors. The expression of endothelial markers (CD31 and vWF) was detected in xenograft tumors by immunohistochemistry and RT-PCR. Moreover, the expression of VEGF-A, bFGF, flt-1, flk-1, FGFR-1, HoxA9, HoxB3, HoxB7, HoxD3, Pbx1, and Meis1 was detected in xenograft tumors. Interestingly, expressions of bFGF tended to be higher in 3 of the xenograft HSA tumors than in the other tumors. Conclusion We

  5. Postnatal Tendon Growth and Remodeling Requires Platelet-Derived Growth Factor Receptor Signaling.

    Science.gov (United States)

    Sugg, Kristoffer B; Markworth, James F; Disser, Nathaniel P; Rizzi, Andrew M; Talarek, Jeffrey R; Sarver, Dylan C; Brooks, Susan V; Mendias, Christopher L

    2017-12-13

    Platelet-derived growth factor receptor (PDGFR) signaling plays an important role in the fundamental biological activities of many cells that compose musculoskeletal tissues. However, little is known about the role of PDGFR signaling during tendon growth and remodeling in adult animals. Using the hindlimb synergist ablation model of tendon growth, our objectives were to determine the role of PDGFR signaling in the adaptation of tendons subjected to a mechanical growth stimulus, as well as to investigate the biological mechanisms behind this response. We demonstrate that both PDGFRs, PDGFRα and PDGFRβ, are expressed in tendon fibroblasts, and that the inhibition of PDGFR signaling suppresses the normal growth of tendon tissue in response to mechanical growth cues due to defects in fibroblast proliferation and migration. We also identify that membrane type-1 matrix metalloproteinase (MT1-MMP) as an essential proteinase for the migration of tendon fibroblasts through their extracellular matrix. Furthermore, we report that MT1-MMP translation is regulated by PI3K/Akt signaling , while ERK1/2 controls post-translational trafficking of MT1-MMP to the plasma membrane of tendon fibroblasts. Taken together, these findings demonstrate that PDGFR signaling is necessary for postnatal tendon growth and remodeling, and that MT1-MMP is a critical mediator of tendon fibroblast migration and a potential target for the treatment of tendon injuries and diseases.

  6. Hepatic receptors for homologous growth hormone in the eel

    International Nuclear Information System (INIS)

    Hirano, T.

    1991-01-01

    The specific binding of 125I-labeled eel growth hormone (eGH) to liver membranes of the eel was examined. The specific binding to the 10,000g pellet was greater than that to the 600g pellet. The specific binding was linear up to about 100 mg fresh tissue, and was saturable with increasing amounts of membrane. The specific binding was pH-, temperature-, and time-dependent, with the optimum pH at 7.4, and greater specific binding was obtained at 15 and 25 degrees than at 35 degrees. Scatchard analysis of liver binding gave an association constant of 1.1 x 10(9) M-1 and a capacity of 105 fmol/mg protein. The receptor preparation was highly specific for GHs. Natural and recombinant eel GHs as well as recombinant salmon GH competed equally with 125I-eGH for the receptor sites of the 10,000g liver membrane. Ovine GH was more potent in displacing the labeled eGH than the homologous eel hormone. Tilapia GH and ovine prolactin (PRL) were needed in greater amounts (40 times) than eGH to displace the labeled eGH. Salmon and tilapia PRLs were still less potent (500 times) than eGH. There was no displacement with eel PRL. No significant change in the specific binding was seen 1 week after hypophysectomy, whereas injection of eGH into the hypophysectomized eel caused a significant reduction after 24 hr. The binding to the membrane fractions from gills, kidney, muscle, intestine, and brain was low and exclusively nonspecific, indicating the presence of specific GH receptors predominantly in the liver

  7. Growth hormone receptor expression and function in pituitary adenomas

    DEFF Research Database (Denmark)

    Clausen, Lene R; Kristiansen, Mikkel T; Rasmussen, Lars M

    2004-01-01

    OBJECTIVE AND DESIGN: Hypopituitarism, in particular GH deficiency, is prevalent in patients with clinically nonfunctioning pituitary adenomas (NFPAs) both before and after surgery. The factors regulating the growth of pituitary adenomas in general and residual tumour tissue in particular...... are not fully characterized, and the effect of GH and IGF-I on human pituitary cell proliferation has not previously been reported. In NFPA tissue from 14 patients we evaluated GH receptor (GHR) expression and signal transduction, and the effect of GH and IGF-I exposure on cell proliferation and hormone...... of transcription 5) phosphorylation was measured by Western blot analysis as an index of GHR signalling; cell proliferation was evaluated by [H3]-thymidine incorporation and glycoprotein hormone production analysed by radioimmunoassay (RIA). RESULTS: All adenomas investigated expressed the GHR...

  8. Argos inhibits epidermal growth factor receptor signalling by ligand sequestration.

    Science.gov (United States)

    Klein, Daryl E; Nappi, Valerie M; Reeves, Gregory T; Shvartsman, Stanislav Y; Lemmon, Mark A

    2004-08-26

    The epidermal growth factor receptor (EGFR) has critical functions in development and in many human cancers. During development, the spatial extent of EGFR signalling is regulated by feedback loops comprising both well-understood activators and less well-characterized inhibitors. In Drosophila melanogaster the secreted protein Argos functions as the only known extracellular inhibitor of EGFR, with clearly identified roles in multiple stages of development. Argos is only expressed when the Drosophila EGFR (DER) is activated at high levels, and downregulates further DER signalling. Although there is ample genetic evidence that Argos inhibits DER activation, the biochemical mechanism has not been established. Here we show that Argos inhibits DER signalling without interacting directly with the receptor, but instead by sequestering the DER-activating ligand Spitz. Argos binds tightly to the EGF motif of Spitz and forms a 1:1 (Spitz:Argos) complex that does not bind DER in vitro or at the cell surface. Our results provide an insight into the mechanism of Argos function, and suggest new strategies for EGFR inhibitor design.

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

    DEFF Research Database (Denmark)

    Christensen, Claus; Berezin, Vladimir; Bock, Elisabeth

    2011-01-01

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

  10. The presence of the d3-growth hormone receptor polymorphism is negatively associated with fetal growth but positively associated with postnatal growth in healthy subjects

    DEFF Research Database (Denmark)

    Jensen, Rikke Beck; Vielwerth, Signe; Larsen, Torben Kjeldgaard

    2007-01-01

    A common polymorphism in the GH receptor (GHR) gene has been linked to increased growth response in GH-treated patients. No former study has focused on the association to prenatal growth.......A common polymorphism in the GH receptor (GHR) gene has been linked to increased growth response in GH-treated patients. No former study has focused on the association to prenatal growth....

  11. Fibroblast growth factor receptor 3 effects on proliferation and telomerase activity in sheep growth plate chondrocytes

    Directory of Open Access Journals (Sweden)

    Smith Logan B

    2012-12-01

    Full Text Available Abstract Background Fibroblast growth factor receptor 3 (FGFR3 inhibits growth-plate chondrocyte proliferation and limits bone elongation. Gain-of-function FGFR3 mutations cause dwarfism, reduced telomerase activity and shorter telomeres in growth plate chondroyctes suggesting that FGFR3 reduces proliferative capacity, inhibits telomerase, and enhances senescence. Thyroid hormone (T3 plays a role in cellular maturation of growth plate chondrocytes and a known target of T3 is FGFR3. The present study addressed whether reduced FGFR3 expression enhanced telomerase activity, mRNA expression of telomerase reverse transcriptase (TERT and RNA component of telomerase (TR, and chondrocyte proliferation, and whether the stimulation of FGFR3 by T3 evoked the opposite response. Results Sheep growth-plate proliferative zone chondrocytes were cultured and transfected with siRNA to reduce FGFR3 expression; FGFR3 siRNA reduced chondrocyte FGFR3 mRNA and protein resulting in greater proliferation and increased TERT mRNA expression and telomerase activity (p 3 significantly enhanced FGFR3 mRNA and protein expression and reduced telomerase activity (p 3 at the growth plate may be partially mediated through the FGFR3 pathway. Conclusions The results suggest that FGFR3 inhibits chondrocyte proliferation by down-regulating TERT expression and reducing telomerase activity indicating an important role for telomerase in sustaining chondrocyte proliferative capacity during bone elongation.

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

    Science.gov (United States)

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

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

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

    International Nuclear Information System (INIS)

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

    1990-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Andersen, A.S.; Kjeldsen, T.; Wiberg, F.C.; Christensen, P.M.; Rasmussen, J.S.; Norris, K.; Moeller, K.B.; Moeller, N.P.H. (Biopharmaceuticals Div., Bagsvaerd (Denmark))

    1990-08-14

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

  15. Bone growth and turnover in progesterone receptor knockout mice.

    Energy Technology Data Exchange (ETDEWEB)

    Rickard, David J.; Iwaniec, Urszula T.; Evans, Glenda; Hefferan, Theresa E.; Hunter, Jaime C.; Waters, Katrina M.; Lydon, John P.; O' Malley, Bert W.; Khosla, Sundeep; Spelsberg, Thomas C.; Turner, Russell T.

    2008-05-01

    The role of progesterone receptor (PR) signaling in skeletal metabolism is controversial. To address whether signaling through the PR is necessary for normal bone growth and turnover, we performed histomorphometric and mCT analyses of bone from homozygous female PR knockout (PRKO) mice at 6, 12, and 26 weeks of age. These mice possess a null mutation of the PR locus, which blocks the gene expression of A and B isoforms of PR. Body weight gain, uterine weight gain and tibia longitudinal bone growth was normal in PRKO mice. In contrast, total and cortical bone mass were increased in long bones of post-pubertal (12 and 26-week-old) PRKO mice, whereas cancellous bone mass was normal in the tibia but increased in the humerus. The striking 57% decrease in cancellous bone from the proximal tibia metaphysis which occurred between 6 and 26 weeks in WT mice was abolished in PRKO mice. The improved bone balance in aging PRKO mice was associated with elevated bone formation and a tendency toward reduced osteoclast perimeter. Taken together, these findings suggest that PR signaling in mice attenuates the accumulation of cortical bone mass during adolescence and is required for early age-related loss of cancellous bone.

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

    International Nuclear Information System (INIS)

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

    2010-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Stephen B. Hughes

    2013-08-01

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

  18. Epidermal growth factor receptor (EGFR) involvement in successful growth hormone (GH) signaling in GH transduction defect.

    Science.gov (United States)

    Kostopoulou, Eirini; Rojas-Gil, Andrea Paola; Karvela, Alexia; Spiliotis, Bessie E

    2017-02-01

    Growth hormone (GH) transduction defect (GHTD) is a growth disorder with impaired signal transducer and activator of transcription 3 (STAT3) phosphorylation mediated by overexpression of cytokine-inducible SH2-containing protein (CIS), which causes increased growth hormone receptor (GHR) degradation. This study investigated the role of epidermal growth factor (EGF) in the restoration of normal GH signaling in GHTD. Protein expression, cellular localization and physical contact of proteins of the GH and EGF signaling pathways were studied by Western immunoblotting, immunofluorescence and co-immunoprecipitation, respectively. These were performed in fibroblasts of one GHTD patient (P) and one control child (C) at the basal state and after induction with human GH (hGH) 200 μg/L (GH200), either with or without silencing of CIS mRNA, and after induction with hGH 1000 μg/L (GH1000) or 50 ng/mL EGF. The membrane availability of the EGF receptor (EGFR) and the activated EGFR (pEGFR) was increased in P only after simultaneous GH200 and silencing of CIS mRNA or with GH1000, whereas this occurred in C after GH200 alone. After EGF induction, the membrane localization of GHR, STAT3 and that of EGFR were increased in P more than in C. In conclusion, in GHTD, the EGFR seems to participate in successful GH signaling, but induction of GHTD fibroblasts with a higher dose of hGH is needed. The EGF/EGFR pathway, in contrast to the GH/GHR pathway, seems to function normally in P and is more primed compared to C. The involvement of the EGFR in successful GH signaling may explain the catch-up growth seen in the Ps when exogenous hGH is administered.

  19. Absence of serum growth hormone binding protein in patients with growth hormone receptor deficiency (Laron dwarfism)

    International Nuclear Information System (INIS)

    Daughaday, W.H.; Trivedi, B.

    1987-01-01

    It has recently been recognized that human serum contains a protein that specifically binds human growth hormone (hGH). This protein has the same restricted specificity for hGH as the membrane-bound GH receptor. To determine whether the GH-binding protein is a derivative of, or otherwise related to, the GH receptor, the authors have examined the serum of three patients with Laron-type dwarfism, a condition in which GH refractoriness has been attributed to a defect in the GH receptor. The binding of 125 I-labeled hGH incubated with serum has been measured after gel filtration of the serum through an Ultrogel AcA 44 minicolumn. Results are expressed as percent of specifically bound 125 I-hGH and as specific binding relative to that of a reference serum after correction is made for endogenous GH. The mean +/- SEM of specific binding of sera from eight normal adults (26-46 years of age) was 21.6 +/- 0.45%, and the relative specific binding was 101.1 +/- 8.6%. Sera from 11 normal children had lower specific binding of 12.5 +/- 1.95% and relative specific binding of 56.6 +/- 9.1%. Sera from three children with Laron-type dwarfism lacked any demonstrable GH binding, whereas sera from 10 other children with other types of nonpituitary short stature had normal relative specific binding. They suggest that the serum GH-binding protein is a soluble derivative of the GH receptor. Measurement of the serum GH-binding protein may permit recognition of other abnormalities of the GH receptor

  20. Inhibition of fibroblasts reduced head and neck cancer growth by targeting fibroblast growth factor receptor.

    Science.gov (United States)

    Sweeny, Larissa; Liu, Zhiyong; Lancaster, William; Hart, Justin; Hartman, Yolanda E; Rosenthal, Eben L

    2012-07-01

    Head and neck squamous cell carcinoma (HNSCC) is a complex disease process involving interactions with carcinoma-associated fibroblasts and endothelial cells. We further investigated these relationships by suppressing stromal cell growth through the inhibition of fibroblast growth factor receptor (FGFR). Preclinical investigation. HNSCC cell lines (FADU, OSC19, Cal27, SCC1, SCC5, SCC22A), fibroblast (HS27), and endothelial cells (human umbilical vascular endothelial cell) were cultured individually or in coculture. Proliferation was assessed following treatment with a range of physiologic concentrations of FGFR inhibitor PD173074. Mice bearing established HNSCC xenografts were treated with PD173074 (12 mg/kg), and tumor histology was analyzed for stromal composition, proliferation (Ki67 staining), and apoptosis (TUNEL [terminal deoxynucleotidyl transferase dUTP nick end labeling] staining). In vitro, inhibition of FGFR with PD173074 dramatically reduced proliferation of fibroblasts and endothelial cells compared to untreated controls. However, HNSCC cell proliferation was not affected by inhibition of FGFR. When cocultured with fibroblasts, HNSCC cells proliferation increased by 15% to 80% (P fibroblast-enhanced tumor cell growth was suppressed by FGFR inhibition. Additionally, treatment of mice bearing HNSCC xenografts with PD173074 resulted in significant growth inhibition (P < .001). Additionally, those tumors from mice treated with PD173074 had a smaller stromal component, decreased proliferation, and increased apoptosis. Targeting the FGFR pathway in head and neck cancer acts through the stromal components to decrease HNSCC growth in vivo and in vitro. Copyright © 2012 The American Laryngological, Rhinological, and Otological Society, Inc.

  1. A peptide antagonist of the ErbB1 receptor inhibits receptor activation, tumor cell growth and migration in vitro and xenograft tumor growth in vivo

    DEFF Research Database (Denmark)

    Xu, Ruodan; Povlsen, Gro Klitgaard; Soroka, Vladislav

    2010-01-01

    The epidermal growth factor family of receptor tyrosine kinases (ErbBs) plays essential roles in tumorigenesis and cancer disease progression, and therefore has become an attractive target for structure-based drug design. ErbB receptors are activated by ligand-induced homo- and heterodimerization......B1 phosphorylation, cell growth, and migration in two human tumor cell lines, A549 and HN5, expressing moderate and high ErbB1 levels, respectively. Furthermore, we show that Inherbin3 inhibits tumor growth in vivo and induces apoptosis in a tumor xenograft model employing the human non-small cell...... lung cancer cell line A549. The Inherbin3 peptide may be a useful tool for investigating the mechanisms of ErbB receptor homo- and heterodimerization. Moreover, the here described biological effects of Inherbin3 suggest that peptide-based targeting of ErbB receptor dimerization is a promising anti...

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

    Science.gov (United States)

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

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

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

    International Nuclear Information System (INIS)

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

    1987-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Marchal Joëlle

    2005-10-01

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

  5. Growth hormone receptor/binding protein: physiology and function.

    Science.gov (United States)

    Herington, A C; Ymer, S I; Stevenson, J L; Roupas, P

    1994-07-01

    Soluble truncated forms of the growth hormone receptor (GHR) are present in the circulation of many species and are also produced by many tissues/cell types. The major high-affinity forms of these GH-binding proteins (GHBP) are derived by alternative splicing of GHR mRNA in rodents, but probably by proteolytic cleavage in other species. Questions still remain with respect to the origins, native molecular form(s), physiology, and function of the GHBPs, however. The observation that GH induces dimerization of the soluble GHBP and membrane GHR, and that dimerization of GHR appears to be critical for GH bioactivity suggests that the presentation of GH to target cells, in an unbound form or as a monomeric or dimeric complex with GHBP, may have significant implications for the ability of GH to activate specific postreceptor signaling pathways (tyrosine kinase, protein kinase C, G-protein pathways) known to be utilized by GH for its diverse biological effects. This minireview addresses some of these aspects and highlights several new questions which have arisen as a result of recent advances in our understanding of the structure, function, and signaling mechanisms of the membrane bound GHR.

  6. Growth hormone receptor/binding protein: Physiology and function

    Energy Technology Data Exchange (ETDEWEB)

    Herington, A.C.; Ymer, S.I.; Stevenson, J.L.; Roupas, P. [Royal Children`s Hospital, Melbourne (Australia)

    1994-12-31

    Soluble truncated forms of the growth hormone receptor (GHR) are present in the circulation of many species and are also produced by many tissues/cell types. The major high-affinity forms of these GH-binding proteins (GHBP) are derived by alternative splicing of GHR mRNA in rodents, but probably by proteolytic cleavage in other species. Questions still remain with respect to the origins, native molecular forms(s), physiology, and function of the GHBPs, however. The observation that GH induces dimerization of the soluble GHBP and a membrane GHR, and that dimerization of GHR appears to be critical for GH bioactivity suggests that the presentation of GH to target cells, in an unbound form or as a monomeric or dimeric complex with GHBP, may have significant implications for the ability of GH to activate specific postreceptor signaling pathways (tyrosine kinase, protein kinase C, G-protein pathways) known to be utilized by GH for its diverse biological effects. This minireview addresses some of these aspects and highlights several new questions which have arisen as a result of recent advances in our understanding of the structure, function, and signaling mechanisms of the membrane bound GHR. 43 refs.

  7. Signaling of ghrelin and its functional receptor, the growth hormone secretagogue receptor, promote tumor growth in glioblastomas.

    Science.gov (United States)

    Okada, Yousuke; Sugita, Yasuo; Ohshima, Koichi; Morioka, Motohiro; Komaki, Satoru; Miyoshi, Junko; Abe, Hideyuki

    2016-12-01

    Ghrelin is a 28-amino-acid peptide that is the endogenous ligand for the pituitary growth hormone secretagogue receptor (GHS-R). Ghrelin is mainly produced from the stomach, but it is also expressed by various other tissues, including the CNS under normal conditions. Physiologically, ghrelin regulates appetite, gut motility, and GH release from the anterior pituitary, as well as cardiovascular and immune systems. Recent studies also indicate that ghrelin and GHS-R may play an important autocrine/paracrine role in neoplastic conditions. In order to clarify the role of ghrelin/GHS-R in gliomas, the present study assessed the expression of ghrelin and its functional receptor, GHS-R1a, in 39 glioblastomas (GBs), 13 anaplastic astrocytomas (AAs) and 11 diffuse astrocytomas (DAs) using immunohistochemical analyses. Immunohistochemical staining was evaluated as follows: no staining; 1+, 0-10% positive cells; 2+, 10-50% positive cells; 3+, >50% positive cells. Ghrelin expression was detected in 52 of 63 cases of which 38, 13 and one were scored as 3+, 2+ and 1+, respectively. GHS-R1a expression was detected in 45 of 63 cases of which 29, 15 and one were scored as 3+, 2+ and 1+, respectively. Ghrelin immunoreactivity was observed in 38 of 39 GBs, 12 of 13 AAs and two of 11 DAs. GHS-R1a immunoreactivity was observed in 39 of 39 GBs, five of 13 AAs, and one of 11 DAs. AAs and GBs showed moderate or strong immunostaining of ghrelin/GHS-R1a in the tumor cells and in proliferating microvessels. Patients were classified into lower to moderate-score, and high-score ghrelin/GHS-R categories according to the principal component and cluster analyses. Multivariate analysis of overall survival indicated that there was a significant difference (P = 0.0001) in the survival rate between these two groups. The combined results indicated that expression of the ghrelin/GHS-R1a axis increases the growth of AAs and GBs through an autocrine/paracrine mechanism. © 2016 Japanese Society of

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

    DEFF Research Database (Denmark)

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

    2000-01-01

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

  9. Bevacizumab reduces tumor targeting of antiepidermal growth factor and anti-insulin-like growth factor 1 receptor antibodies

    NARCIS (Netherlands)

    Heskamp, Sandra; Boerman, Otto C.; Molkenboer-Kuenen, Janneke D. M.; Oyen, Wim J. G.; van der Graaf, Winette T. A.; van Laarhoven, Hanneke W. M.

    2013-01-01

    Bevacizumab (antivascular endothelial growth factor [anti-VEGF]) and cetuximab (antiepidermal growth factor receptor [anti-EGFR]) are approved antibodies for treatment of cancer. However, in advanced colorectal cancer, the combination fails to improve survival. As the reason for the lack of activity

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

    International Nuclear Information System (INIS)

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

    1985-01-01

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

  11. Identification of growth hormone receptor in plexiform neurofibromas of patients with neurofibromatosis type 1

    Directory of Open Access Journals (Sweden)

    Karin Soares Gonçalves Cunha

    2008-01-01

    Full Text Available OBJECTIVE: The aim of this study was to investigate the presence of growth hormone receptor in plexiform neurofibromas of neurofibromatosis type 1 patients. INTRODUCTION: The development of multiple neurofibromas is one of the major features of neurofibromatosis type 1. Since neurofibromas commonly grow during periods of hormonal change, especially during puberty and pregnancy, it has been suggested that hormones may influence neurofibromatosis type 1 neurofibromas. A recent study showed that the majority of localized neurofibromas from neurofibromatosis type 1 patients have growth hormone receptor. METHODS: Growth hormone receptor expression was investigated in 5 plexiform neurofibromas using immunohistochemistry. RESULTS: Four of the 5 plexiform neurofibromas were immunopositive for growth hormone receptor. CONCLUSION: This study suggests that growth hormone may influence the development of plexiform neurofibromas in patients with neurofibromatosis type 1.

  12. Nicotine acts on growth plate chondrocytes to delay skeletal growth through the alpha7 neuronal nicotinic acetylcholine receptor.

    Directory of Open Access Journals (Sweden)

    Atsuo Kawakita

    Full Text Available BACKGROUND: Cigarette smoking adversely affects endochondral ossification during the course of skeletal growth. Among a plethora of cigarette chemicals, nicotine is one of the primary candidate compounds responsible for the cause of smoking-induced delayed skeletal growth. However, the possible mechanism of delayed skeletal growth caused by nicotine remains unclarified. In the last decade, localization of neuronal nicotinic acetylcholine receptor (nAChR, a specific receptor of nicotine, has been widely detected in non-excitable cells. Therefore, we hypothesized that nicotine affect growth plate chondrocytes directly and specifically through nAChR to delay skeletal growth. METHODOLOGY/PRINCIPAL FINDINGS: We investigated the effect of nicotine on human growth plate chondrocytes, a major component of endochondral ossification. The chondrocytes were derived from extra human fingers. Nicotine inhibited matrix synthesis and hypertrophic differentiation in human growth plate chondrocytes in suspension culture in a concentration-dependent manner. Both human and murine growth plate chondrocytes expressed alpha7 nAChR, which constitutes functional homopentameric receptors. Methyllycaconitine (MLA, a specific antagonist of alpha7 nAChR, reversed the inhibition of matrix synthesis and functional calcium signal by nicotine in human growth plate chondrocytes in vitro. To study the effect of nicotine on growth plate in vivo, ovulation-controlled pregnant alpha7 nAChR +/- mice were given drinking water with or without nicotine during pregnancy, and skeletal growth of their fetuses was observed. Maternal nicotine exposure resulted in delayed skeletal growth of alpha7 nAChR +/+ fetuses but not in alpha7 nAChR -/- fetuses, implying that skeletal growth retardation by nicotine is specifically mediated via fetal alpha7 nAChR. CONCLUSIONS/SIGNIFICANCE: These results suggest that nicotine, from cigarette smoking, acts directly on growth plate chondrocytes to decrease

  13. Agonists of fibroblast growth factor receptor induce neurite outgrowth and survival of cerebellar granule neurons

    DEFF Research Database (Denmark)

    Li, Shizhong; Christensen, Claus; Køhler, Lene B

    2009-01-01

    Fibroblast growth factor receptor (FGFR) signaling is pivotal in the regulation of neurogenesis, neuronal differentiation and survival, and synaptic plasticity both during development and in adulthood. In order to develop low molecular weight agonists of FGFR, seven peptides, termed hexafins...

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

    DEFF Research Database (Denmark)

    Hansen, Klaus; Rönnstrand, L; Rorsman, C

    1997-01-01

    The nonreceptor tyrosine kinase Src binds to and is activated by the beta-receptor for platelet-derived growth factor (PDGF). The interaction leads to Src phosphorylation of Tyr934 in the kinase domain of the receptor. In the course of the functional characterization of this phosphorylation, we...

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

    NARCIS (Netherlands)

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

    1994-01-01

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

  16. Identification of intracellular domains in the growth hormone receptor involved in signal transduction

    DEFF Research Database (Denmark)

    Billestrup, N; Allevato, G; Norstedt, G

    1994-01-01

    The growth hormone (GH) receptor belongs to the GH/prolactin/cytokine super-family of receptors. The signal transduction mechanism utilized by this class of receptors remains largely unknown. In order to identify functional domains in the intracellular region of the GH receptor we generated...... a number of GH receptor mutants and analyzed their function after transfection into various cell lines. A truncated GH receptor missing 184 amino acids at the C-terminus was unable to mediate GH effects on transcription of the Spi 2.1 and insulin genes. However, this mutant was fully active in mediating GH...... as well as metabolic effects. These results indicate that the intracellular part of the GH receptor can be divided into at least three functional domains: (i) for transcriptional activity, two domains are involved, one located in the C-terminal 184 amino acids and the other in the proline-rich domain; (ii...

  17. Enhancement of insulin-like growth factor 2 receptors in glioblastoma

    International Nuclear Information System (INIS)

    Sara, V.; Prisell, Per; Sjoegren, Barbro; Enberg, Goesta

    1986-01-01

    The somatomedins (IGF-1/IGF-2) are a family of growth-promoting hormones which have been identified in the human central nervous system where their specific receptors are distributed. The present study identified somatomedin receptors in glioblastoma and compared them with those found in normal brain. A significant enhancement in the binding of 125 1-IGF-2 but not 125 1-IGF-1 to glioblastoma membranes was found. A fourfold increase in IGF-2 receptor concentration was observed. These findings indicate enhanced expression of the IGF-2 receptor in glioblastoma. (author)

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

    International Nuclear Information System (INIS)

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

    1986-01-01

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

  19. E-cadherin homophilic ligation inhibits cell growth and epidermal growth factor receptor signaling independently of other cell interactions

    DEFF Research Database (Denmark)

    Perrais, Michaël; Chen, Xiao; Perez-Moreno, Mirna

    2007-01-01

    growth inhibitory signals. To address this question, we have selectively formed E-cadherin homophilic bonds at the cell surface of isolated epithelial cells by using functionally active recombinant E-cadherin protein attached to microspheres. We find that E-cadherin ligation alone reduces the frequency...... of cells entering the S phase, demonstrating that E-cadherin ligation directly transduces growth inhibitory signals. E-cadherin binding to beta-catenin is required for cell growth inhibition, but beta-catenin/T-cell factor transcriptional activity is not involved in growth inhibition resulting from...... homophilic binding. Neither E-cadherin binding to p120-catenin nor beta-catenin binding to alpha-catenin, and thereby the actin cytoskeleton, is required for growth inhibition. E-cadherin ligation also inhibits epidermal growth factor (EGF) receptor-mediated growth signaling by a beta...

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

    Science.gov (United States)

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

    2013-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Lasse Henriksen

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

  2. Defects in articular cartilage metabolism and early arthritis in fibroblast growth factor receptor 3 deficient mice

    NARCIS (Netherlands)

    Valverde-Franco, G.; Binette, J.S.; Li, W.; Wang, H.; Chai, S.; Laflamme, F.; Tran-Khanh, N.; Quenneville, E.; Meijers, T.; Poole, A.R.; Mort, J.S.; Buschmann, M.D.; Henderson, J.E.

    2006-01-01

    Fibroblast growth factor (FGF) receptor 3 has been identified as a key regulator of endochondral bone development and of post-natal bone metabolism through its action on growth plate chondrocytes and osteoblasts, respectively. It has also been shown to promote chondrogenesis and cartilage production

  3. A new role of growth hormone and insulin growth factor receptor type 1 in neonatal inflammatory nociception

    Directory of Open Access Journals (Sweden)

    Alfredo Manzano-García

    2017-08-01

    Full Text Available Abstract. Growth hormone (GH and insulin growth factor 1 (IGF1 are implicated in nociceptive processing; it has been reported that the latter participates in neonatal inflammatory nociception. In the target article, the authors propose that local inflammation evoked by carrageenan administration in mice produces a decrease in the local GH levels and an increment of IGF1 receptors type 1 expression, this produces behavioral nociception and peripheral sensitization that can be prevented by GH systemic administration pretreatment.

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

    DEFF Research Database (Denmark)

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

    1992-01-01

    Epidermal growth factor (EGF) receptor expression was evaluated in a panel of 21 small cell lung cancer cell lines with radioreceptor assay, affinity labeling, and Northern blotting. We found high-affinity receptors to be expressed in 10 cell lines. Scatchard analysis of the binding data...... lung cancer cell lines express the EGF receptor....... of EGF receptor mRNA in all 10 cell lines that were found to be EGF receptor-positive and in one cell line that was found to be EGF receptor-negative in the radioreceptor assay and affinity labeling. Our results provide, for the first time, evidence that a large proportion of a broad panel of small cell...

  5. Rat insulinoma cells express both a 115-kDa growth hormone receptor and a 95-kDa prolactin receptor structurally related to the hepatic receptors

    DEFF Research Database (Denmark)

    Møldrup, Annette; Billestrup, N; Nielsen, Jens Høiriis

    1990-01-01

    Insulin-producing rat islet RIN-5AH tumor cells express multiple binding sites for human growth hormone (hGH). The effect of rat growth hormone (rGH), rat prolactin (rPRL), and human placental lactogen (hPL) on the binding of 125I-labeled hGH (125I-hGH) to RIN-5AH cells revealed the presence...... of both lactogen and somatogen receptor populations. Covalent cross-linking of 125I-hGH, 125I-rGH, and 125I-rPRL to the RIN cells identified a 115-kDa somatogen receptor protein that binds hGH and rGH but not rPRL and hPL, and a 95-kDa lactogen receptor protein that binds hGH, rPRL, and hPL but not r...

  6. Interaction of the αβ dimers of the insulin-like growth factor I receptor required for receptor autophosphorylation

    International Nuclear Information System (INIS)

    Tollesfsen, S.E.; Stoszek, R.M.; Thompson, K.

    1991-01-01

    The authors have recently found that association of the two αβ dimers of the insulin-like growth factor I (IGF I) receptor is required for formation of a high-affinity binding site for IGF I. To determine the structural requirements for IGF I activated kinase activity, they have examined the effect of dissociation of the two αβ dimers of the IGF I receptor on β subunit autophosphorylation. The αβ dimers formed after treatment with 2 mM dithiothreitol (DTT) at pH 8.75 for 5 min were separated from IGF I receptor remaining as tetramers after DTT treatment by fast protein liquid chromatography on a Superose 6 gel filtration column. Purification of the αβ dimers was confirmed by Western blot analysis using 125 I-labeled αIR-3, a monoclonal antibody to the IGF I receptor. Autophosphorylation of the IGF I receptor (αβ) 2 tetramer, treated without DTT or remaining after DTT treatment, is stimulated 1.6-2.9-fold by IGF I. In contrast, autophosporylation of the αβ dimers incubated in the presence or absence of IGF I (100 ng/mL) does not occur. Both IGF I receptor dimers and tetramers exhibit similar kinase activities using the synthetic substrate Arg-Arg-Leu-Ile-Glu-Asp-Ala-Glu-Tyr-Ala-Ala-Arg-Gly, indicating that the failure to detect autophosphorylation of the IGF I receptor dimers does not result from inactivation of the kinase by DTT treatment. They conclude that autophosphorylation of the IGF I receptor depends upon the interaction of the two αβ dimers

  7. Introduction of exogenous growth hormone receptors augments growth hormone-responsive insulin biosynthesis in rat insulinoma cells

    International Nuclear Information System (INIS)

    Billestrup, N.; Moeldrup, A.; Serup, P.; Nielsen, J.H.; Mathews, L.S.; Norstedt, G.

    1990-01-01

    The stimulation of insulin biosynthesis in the pancreatic insulinoma cell line RIN5-AH by growth hormone (GH) is initiated by GH binding to specific receptors. To determine whether the recently cloned rat hepatic GH receptor is able to mediate the insulinotropic effect of GH, the authors have transfected a GH receptor cDNA under the transcriptional control of the human metallothionein promoter into RIN5-AH cells. The transfected cells were found to exhibit an increased expression of GH receptors and to contain a specific GH receptor mRNA that was not expressed in the parent cell line. The expression of GH receptors in one clone (1.24) selected for detailed analysis was increased 2.6-fold compared to untransfected cells. The increased GH receptor expression was accompanied by an increased responsiveness to GH. Thus, the maximal GH-stimulated increase of insulin biosynthesis was 4.1-fold in 1.24 cells compared to 1.9-fold in the nontransfected RIN5-AH cells. The expression of the transfected receptor was stimulated 1.6- and 2.3-fold when cells were cultured in the presence of 25 or 50 μM Zn 2+ was associated with an increased magnitude of GH-stimulated insulin biosynthesis. A close stoichiometric relationship between the level of receptor expression and the level of GH-stimulated insulin biosynthesis was observed. They conclude from these results that the hepatic GH receptor is able to mediate the effect of GH on insulin biosynthesis in RIN5-AH cells

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

    DEFF Research Database (Denmark)

    Sugiyama, Nami; Varjosalo, Markku; Meller, Pipsa

    2010-01-01

    Aberrant expression and polymorphism of fibroblast growth factor receptor 4 (FGFR4) has been linked to tumor progression and anticancer drug resistance. We describe here a novel mechanism of tumor progression by matrix degradation involving epithelial-to-mesenchymal transition in response...

  9. Determination of vascular endothelial- and fibroblast- growth factor receptors in a mouse fibrosarcoma tumor model following photodynamic therapy

    International Nuclear Information System (INIS)

    Ziolkowski, P.; Osieka, B.J.; Symonwicz, K.; Chmielwski, P.; Latos-Grazynski, L.; Bronowicz, A.

    2004-01-01

    The role of angiogenic molecules, like vascular endothelial growth factor and fibroblast growth factor in tumor angio genesis was well confirmed. Photodynamic therapy action is, to very high degree, based on tumor vasculature damage. Therefore, it seemed to be important to evaluate growth factor receptors after photodynamic therapy. The extent of receptor expression was studied by immuno-histochemical method. In this study, vascular endothelial growth factor receptor and fibroblast growth factor receptor have been evaluated at different time points after photodynamic therapy of tumor- bearing BALB/c mice. Two sensitizer: hematoporphyrin derivative and 21, 23-dithia porphyrin were given intraperitoneally in doses: 1.25, 2.5 and 5.0 mg/kg followed by light irradiation at total doses: 50 and 100 J/sq.cm 24 hours later. The number of vascular endothelial growth factor and receptor and fibroblast growth factor in control samples did not exceed 40 per one vessel, whereas after photodynamic therapy, a significant decrease in the number of both receptors was observed. No differences between hematoporphyrin derivative and dithia porphyrin- photodynamic therapy in anti- receptor activities were observed (p<0.001 for vascular endothelial growth factor and p<0.002 for receptor and fibroblast growth factor ). The observed decrease in vascular endothelial growth factor and receptor and fibroblast growth factor amount confirms that after photodynamic therapy, some proteins are inactivated and such a decrease may influence photodynamic therapy effectiveness

  10. Evolutionary aspects of growth hormones and prolactins and their receptors

    International Nuclear Information System (INIS)

    Tarpey, J.F.

    1986-01-01

    The interactions of GH's, PRL's and PL's with receptors for GH and PRL were examined from a comparative and evolutionary viewpoint. The binding of 125 I-bGH to membrane preparations from liver of representatives of the major classes of non-mammalian vertebrates was also studied. Only hepatic membranes from sturgeon and Gillichthys had significant bGH binding and were further characterized and compared with male rabbit liver membranes in terms of time, temperature, pH, and membrane concentration to optimize binding conditions. The binding of several members of the GH, PRL, PL family of hormones to GH receptors from liver of sturgeon, Gillichthys, rabbit, mouse and rat was investigated. in terms of hormonal specificity, the mammalian receptors and the sturgeon binding sites were similar, while Gillichthys receptors had a different pattern of hormonal specificity. The binding of 125 I-oPRL to renal membranes of the turtle, Pseudemys scripta elegans, was characterized and compared to PRL binding sites of kidney membranes of the bullfrog, Rana catesbeiana, and the tiger salamander, Ambystoma tigrinum

  11. Human epidermal growth factor receptor (HER 2)/neu expression ...

    African Journals Online (AJOL)

    use

    2011-11-23

    Nov 23, 2011 ... receptor (HER 2)/neu and its clinical significance in colorectal cancer, in this study, clinicopathological data and paraffin-embedded specimen .... Correlation between the HER 2/neu protein expression, amplication and clinicopathologic feature in 192 colorectal cancer. Variable. HER2 protein expression. P.

  12. Pumpkin seed extract: Cell growth inhibition of hyperplastic and cancer cells, independent of steroid hormone receptors.

    Science.gov (United States)

    Medjakovic, Svjetlana; Hobiger, Stefanie; Ardjomand-Woelkart, Karin; Bucar, Franz; Jungbauer, Alois

    2016-04-01

    Pumpkin seeds have been known in folk medicine as remedy for kidney, bladder and prostate disorders since centuries. Nevertheless, pumpkin research provides insufficient data to back up traditional beliefs of ethnomedical practice. The bioactivity of a hydro-ethanolic extract of pumpkin seeds from the Styrian pumpkin, Cucurbita pepo L. subsp. pepo var. styriaca, was investigated. As pumpkin seed extracts are standardized to cucurbitin, this compound was also tested. Transactivational activity was evaluated for human androgen receptor, estrogen receptor and progesterone receptor with in vitro yeast assays. Cell viability tests with prostate cancer cells, breast cancer cells, colorectal adenocarcinoma cells and a hyperplastic cell line from benign prostate hyperplasia tissue were performed. As model for non-hyperplastic cells, effects on cell viability were tested with a human dermal fibroblast cell line (HDF-5). No transactivational activity was found for human androgen receptor, estrogen receptor and progesterone receptor, for both, extract and cucurbitin. A cell growth inhibition of ~40-50% was observed for all cell lines, with the exception of HDF-5, which showed with ~20% much lower cell growth inhibition. Given the receptor status of some cell lines, a steroid-hormone receptor independent growth inhibiting effect can be assumed. The cell growth inhibition for fast growing cells together with the cell growth inhibition of prostate-, breast- and colon cancer cells corroborates the ethnomedical use of pumpkin seeds for a treatment of benign prostate hyperplasia. Moreover, due to the lack of androgenic activity, pumpkin seed applications can be regarded as safe for the prostate. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  13. Pentadecapeptide BPC 157 Enhances the Growth Hormone Receptor Expression in Tendon Fibroblasts

    Directory of Open Access Journals (Sweden)

    Chung-Hsun Chang

    2014-11-01

    Full Text Available BPC 157, a pentadecapeptide derived from human gastric juice, has been demonstrated to promote the healing of different tissues, including skin, muscle, bone, ligament and tendon in many animal studies. However, the underlying mechanism has not been fully clarified. The present study aimed to explore the effect of BPC 157 on tendon fibroblasts isolated from Achilles tendon of male Sprague-Dawley rat. From the result of cDNA microarray analysis, growth hormone receptor was revealed as one of the most abundantly up-regulated genes in tendon fibroblasts by BPC 157. BPC 157 dose- and time-dependently increased the expression of growth hormone receptor in tendon fibroblasts at both the mRNA and protein levels as measured by RT/real-time PCR and Western blot, respectively. The addition of growth hormone to BPC 157-treated tendon fibroblasts dose- and time-dependently increased the cell proliferation as determined by MTT assay and PCNA expression by RT/real-time PCR. Janus kinase 2, the downstream signal pathway of growth hormone receptor, was activated time-dependently by stimulating the BPC 157-treated tendon fibroblasts with growth hormone. In conclusion, the BPC 157-induced increase of growth hormone receptor in tendon fibroblasts may potentiate the proliferation-promoting effect of growth hormone and contribute to the healing of tendon.

  14. Peran Transforming Growth Factor-B1 pada Penyakit Ginjal

    Directory of Open Access Journals (Sweden)

    Partini Pudjiastuti Trihono

    2016-11-01

    merupakan sitokin multipoten yang disekresi oleh berbagai sel dalam tubuh. Sitokin TGF- E1 mempunyai kapasitas untuk mengaktivasi fibroblas interstisial, menginduksi apoptosis (yang menyebabkan sel intrinsik ginjal hilang, digantikan dengan jaringan fibrotik, dan diferensiasi sel tubulus menjadi miofibroblas, sehingga terjadi pembentukan jaringan parut ginjal. Jumlah (TGF-E1 di daerah tubulo-interstisial berkorelasi dengan derajat inflamasi interstisial dan atrofi tubulus. Keterlibatan TGF-E1 pada pembentukan jaringan parut ginjal juga melalui peningkatan sintesis matriks ekstra selular. Diketahui bahwa TGF-E1 berperan dalam progresivitas penyakit ginjal. Kadar TGF-E1 di dalam urin kasus glomerulonefritis dengan proteinuria berat, sangat meningkat, dan kadarnya sebanding dengan derajat proteinuria. Peran TGF-E1 dalam progresivitas penyakit ginjal juga melalui terjadinya hipertensi. Angiotensin II sebagai hasil aktivasi sistim renin-angiotensin menstimulasi produksi TGF-E1. Inhibitor enzim konvertase (ACEI dan atau antagonis reseptor angiotensin II terbukti dapat menurunkan proteinuria dan produksi TGF-E1, sehingga kedua obat tersebut dikenal mempunyai efek reno-proteksi.

  15. Prolactin receptor, growth hormone receptor, and putative somatolactin receptor in Mozambique tilapia: tissue specific expression and differential regulation by salinity and fasting.

    Science.gov (United States)

    Pierce, A L; Fox, B K; Davis, L K; Visitacion, N; Kitahashi, T; Hirano, T; Grau, E G

    2007-01-01

    In fish, pituitary growth hormone family peptide hormones (growth hormone, GH; prolactin, PRL; somatolactin, SL) regulate essential physiological functions including osmoregulation, growth, and metabolism. Teleost GH family hormones have both differential and overlapping effects, which are mediated by plasma membrane receptors. A PRL receptor (PRLR) and two putative GH receptors (GHR1 and GHR2) have been identified in several teleost species. Recent phylogenetic analyses and binding studies suggest that GHR1 is a receptor for SL. However, no studies have compared the tissue distribution and physiological regulation of all three receptors. We sequenced GHR2 from the liver of the Mozambique tilapia (Oreochromis mossambicus), developed quantitative real-time PCR assays for the three receptors, and assessed their tissue distribution and regulation by salinity and fasting. PRLR was highly expressed in the gill, kidney, and intestine, consistent with the osmoregulatory functions of PRL. PRLR expression was very low in the liver. GHR2 was most highly expressed in the muscle, followed by heart, testis, and liver, consistent with this being a GH receptor with functions in growth and metabolism. GHR1 was most highly expressed in fat, liver, and muscle, suggesting a metabolic function. GHR1 expression was also high in skin, consistent with a function of SL in chromatophore regulation. These findings support the hypothesis that GHR1 is a receptor for SL. In a comparison of freshwater (FW)- and seawater (SW)-adapted tilapia, plasma PRL was strongly elevated in FW, whereas plasma GH was slightly elevated in SW. PRLR expression was reduced in the gill in SW, consistent with PRL's function in freshwater adaptation. GHR2 was elevated in the kidney in FW, and correlated negatively with plasma GH, whereas GHR1 was elevated in the gill in SW. Plasma IGF-I, but not GH, was reduced by 4 weeks of fasting. Transcript levels of GHR1 and GHR2 were elevated by fasting in the muscle. However

  16. Expression of somatostatin, dopamine, progesterone and growth hormone receptor mRNA in canine cortisol-secreting adrenocortical tumours

    NARCIS (Netherlands)

    Kool, Miriam M J; Galac, Sara; van der Helm, Noortje; Spandauw, Catharina G; Kooistra, Hans S; Mol, Jan A

    2015-01-01

    Cortisol-secreting adrenocortical tumours (AT) in dogs are characterised by uncontrolled growth and excessive cortisol secretion. Dysregulated hormone receptor expression might be involved in tumour growth and hypersecretion of cortisol. The relative mRNA expression of growth hormone receptor,

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

    International Nuclear Information System (INIS)

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

    1996-01-01

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

  18. Epidermal growth factor receptor immunohistochemistry: new opportunities in metastatic colorectal cancer.

    Science.gov (United States)

    Hutchinson, Ryan A; Adams, Richard A; McArt, Darragh G; Salto-Tellez, Manuel; Jasani, Bharat; Hamilton, Peter W

    2015-07-07

    The treatment of cancer is becoming more precise, targeting specific oncogenic drivers with targeted molecular therapies. The epidermal growth factor receptor has been found to be over-expressed in a multitude of solid tumours. Immunohistochemistry is widely used in the fields of diagnostic and personalised medicine to localise and visualise disease specific proteins. To date the clinical utility of epidermal growth factor receptor immunohistochemistry in determining monoclonal antibody efficacy has remained somewhat inconclusive. The lack of an agreed reproducible scoring criteria for epidermal growth factor receptor immunohistochemistry has, in various clinical trials yielded conflicting results as to the use of epidermal growth factor receptor immunohistochemistry assay as a companion diagnostic. This has resulted in this test being removed from the licence for the drug panitumumab and not performed in clinical practice for cetuximab. In this review we explore the reasons behind this with a particular emphasis on colorectal cancer, and to suggest a way of resolving the situation through improving the precision of epidermal growth factor receptor immunohistochemistry with quantitative image analysis of digitised images complemented with companion molecular morphological techniques such as in situ hybridisation and section based gene mutation analysis.

  19. On the use of cells or membranes for receptor binding: growth hormone secretagogues.

    Science.gov (United States)

    Pinyot, A; Nikolovski, Z; Bosch, J; Segura, J; Gutiérrez-Gallego, R

    2010-04-15

    Receptor binding techniques have been widely used in different biochemical applications, with isolated membranes being the most used receptor preparation in this type of assays. In this study, intact cells were compared with isolated membranes as receptor support for radioligand receptor binding assay. The growth hormone secretagogue receptor 1a (GHSR-1a) expressed in human embryonic kidney 293 (HEK293) cells was used as a model of G-protein-coupled receptors. Differences between using intact cells in suspension and using isolated membranes were evaluated for different aspects of the receptor binding assay: total binding variations while both receptor preparations remain on ice, modifications in incubation conditions, saturation, and competition using different agonists. Intact cells are more prone to variability. Although under optimized settings both preparations were equivalent, the K(d) value for intact cells was three times higher than that using isolated membranes. However, no significant differences were observed in competition assays obtaining practically identical K(i) values for all ligands tested. For the GHSR-1a, isolated membranes are the better choice if particular incubation conditions are required (less variability), whereas intact cells yield easy, fast, and physiological conditions for receptor binding assays. Copyright 2010 Elsevier Inc. All rights reserved.

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

    Science.gov (United States)

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

    1992-05-01

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

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

    DEFF Research Database (Denmark)

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

    2013-01-01

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

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

    International Nuclear Information System (INIS)

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

    1987-01-01

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

  3. Intracellular processing of growth hormone receptors by adipocytes in primary culture.

    Science.gov (United States)

    Roupas, P; Herington, A C

    1988-05-01

    Rat adipocytes in primary culture have been used to study the intracellular processing of growth hormone (GH) receptors. Pretreatment of adipocytes with 20 micrograms/ml cycloheximide resulted in a rapid decline (t1/2 approximately 45 min) of the 125I-human growth hormone (hGH) binding capacity of the cells. This decline occurred at a faster rate in the presence of extracellular unlabeled hGH (400 ng/ml) and was not due to receptor occupancy. These data suggest that GH receptors turn over rapidly and constitutively on the plasma membrane and in the absence of protein synthesis are not replaced. Dissociation of GH-receptor complexes was shown not to occur at pH 5.5, the pH encountered in the acidic pre-lysosomal compartments (endosomes) where intracellular dissociation of many hormone-receptor complexes takes place. These data, together, suggest that the majority of GH receptors are not recycled but instead suffer the same fate as the majority of GH, i.e. degradation. To determine the rate of appearance of GH receptors at the cell surface, adipocytes were first treated with trypsin and then incubated at 37 degrees C to permit incorporation of any available GH receptors into the plasma membrane. Binding of 125I-hGH recovered to pre-trypsin levels by 2 h. This recovery was completely blocked by concomitant treatment with monensin, cytochalasin B, colchicine and 2,4-dinitrophenol. NH4Cl had no effect on receptor recovery. These data suggest that once GH receptors are synthesized in the rough endoplasmic reticulum, they travel via the Golgi apparatus to the plasma membrane (by processes involving both microfilaments and microtubules) and are then inserted into the plasma membrane in an energy-dependent step.

  4. Relationship between initial treatment effect of recombinant human growth hormone and exon 3 polymorphism of growth hormone receptor in Chinese children with growth hormone deficiency

    OpenAIRE

    Zheng, Zhangqian; Cao, Lingfeng; Pei, Zhou; Zhi, Dijing; Zhao, Zhuhui; Xi, Li; Cheng, Ruoqian; Luo, Feihong

    2015-01-01

    The aim of this study is to investigate the frequency distribution of exon 3 deleted (d3-GHR) genetic polymorphism of growth hormone receptor (GHR) in growth hormone deficient (GHD) Chinese children and to explore the correlation between the growth promoting effects of recombinant human growth hormone (rhGH) and exon 3 genetic polymorphism of GHR in GHD children. In this study, 111 GHD (excluded small for gestational age) children were treated with rhGH (0.20 mg/kg/week) for six months. The b...

  5. Two-tiered control of epithelial growth and autophagy by the insulin receptor and the ret-like receptor, stitcher.

    Directory of Open Access Journals (Sweden)

    Fergal O'Farrell

    2013-07-01

    Full Text Available Body size in Drosophila larvae, like in other animals, is controlled by nutrition. Nutrient restriction leads to catabolic responses in the majority of tissues, but the Drosophila mitotic imaginal discs continue growing. The nature of these differential control mechanisms that spare distinct tissues from starvation are poorly understood. Here, we reveal that the Ret-like receptor tyrosine kinase (RTK, Stitcher (Stit, is required for cell growth and proliferation through the PI3K-I/TORC1 pathway in the Drosophila wing disc. Both Stit and insulin receptor (InR signaling activate PI3K-I and drive cellular proliferation and tissue growth. However, whereas optimal growth requires signaling from both InR and Stit, catabolic changes manifested by autophagy only occur when both signaling pathways are compromised. The combined activities of Stit and InR in ectodermal epithelial tissues provide an RTK-mediated, two-tiered reaction threshold to varying nutritional conditions that promote epithelial organ growth even at low levels of InR signaling.

  6. Missense mutations in the growth hormone receptor dimerization region in Laron syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Berg, M.A.; Francke, U. [Howard Hughes Medical Institute, Stanford, CA (United States)]|[Univ. of Stanford, CA (United States); Geffner, M.E.; Bersch, N. [Univ. of California, Los Angeles, CA (United States)] [and others

    1994-09-01

    Laron syndrome (LS) is an autosomal recessively inherited condition characterized by insensitivity to endogenous and exogenous GH. Affected individuals have severe episodes and other characteristic features. GH receptor gene mutations are present in all affected individuals in whom molecular studies have been reported. The GH receptor is a plasma membrane-spanning protein in which the extracellular domain binds circulating GH and the intracellular domain interacts with the JAK-2 kinase and possibly other intracellular signaling molecules. GH receptor dimerization occurs on GH binding and is thought to be required for normal signal transduction. We have studied the GH receptor genes of four unrelated individuals affected with LS from the United States, Italy, Saudi Arabia, and India. We have identified four different missense mutations that alter consecutive amino acids 152 to 155 in or near the dimerization domain of the GH receptor. One of these mutations, D152H, has been reported previously in Asian LS patients and, in in vitro studies, the mutant receptor was unable to dimerize. This report increases to over 20 the number of different GH receptor gene mutations that have been reported in LS patients and defines the first apparent mutational {open_quotes}hotspot{close_quotes} region in this gene. This cluster of mutations in patients with classic LS phenotype provides additional in vivo evidence that receptor dimerization plays an important role in signaling GH`s growth promoting and metabolic effects. Further in vitro studies of the mutations in this region are in progress.

  7. Molecular and biochemical analyses of platelet-derived growth factor receptor (PDGFR) B, PDGFRA, and KIT receptors in chordomas.

    Science.gov (United States)

    Tamborini, Elena; Miselli, Francesca; Negri, Tiziana; Lagonigro, M Stefania; Staurengo, Samantha; Dagrada, Gian Paolo; Stacchiotti, Silvia; Pastore, Elisa; Gronchi, Alessandro; Perrone, Federica; Carbone, Antonino; Pierotti, Marco A; Casali, Paolo G; Pilotti, Silvana

    2006-12-01

    We have previously shown the presence of an activated platelet-derived growth factor (PDGF) receptor (PDGFR) B and its ligand PDGFB in a limited number of patients with clinical and radiological responses to imatinib mesylate treatment. This article describes the results of comprehensive molecular/biochemical analyses of the three receptors targeted by the drug (PDGFRB, PDGFRA, and KIT) in a series of 31 chordoma patients. The presence and activation status of PDGFRB, PDGFRA, and KIT receptors were investigated by means of immunoprecipitation and Western blot analyses complemented by immunohistochemistry, their expression level was analyzed by means of real-time PCR, and the occurrence of activating point mutations was investigated by means of cDNA sequencing. The PDGFB, PDGFA, and stem cell factor cognate ligands were investigated by reverse transcription-PCR, and gene status was assessed by fluorescence in situ hybridization. The results show that PDGFRB was highly expressed and phosphorylated, whereas PDGFRA and KIT were less expressed but phosphorylated and thus activated. These findings, together with the absence of gain-of-function mutations and the presence of the cognate ligands, strongly support the hypothesis that the activation mechanism is the autocrine/paracrine loop. No role seems to be played by gene amplification. In the light of our findings, the clinical benefit observed in chordoma patients treated with imatinib seems to be attributable to the switching off of all three receptors.

  8. β-Arrestin Mediates β1-Adrenergic Receptor-Epidermal Growth Factor Receptor Interaction and Downstream Signaling*

    Science.gov (United States)

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

    2009-01-01

    β1-Adrenergic receptor (β1AR) stimulation confers cardioprotection via β-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 β1AR and EGFR form a complex that differentially directs intracellular signaling pathways. β1AR stimulation and EGF ligand can each induce equivalent EGFR phos pho ryl a tion, internalization, and downstream activation of ERK1/2, but only EGF ligand causes translocation of activated ERK to the nucleus, whereas β1AR-stimulated/EGFR-transactivated ERK is restricted to the cytoplasm. β1AR 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 β1AR-EGFR interaction throughout receptor internalization, direct EGF ligand stimulation initiates the internalization of EGFR alone. Continued interaction of β1AR with EGFR following activation is dependent upon C-terminal tail GRK phos pho ryl a tion sites of the β1AR and recruitment of β-arrestin. These data reveal a new signaling paradigm in which β-arrestin is required for the maintenance of a β1AR-EGFR interaction that can direct cytosolic targeting of ERK in response to catecholamine stimulation. PMID:19509284

  9. Human epidermal growth factor receptor 2, epidermal growth factor receptor, and c-MET overexpression and survival in biliary tract cancer: A meta-analysis.

    Science.gov (United States)

    Zhou, Wei; Jiang, Congqing; Zhan, Nan; Lv, Xiaoguang; Fan, Lifang; Ninu, Maskey

    2018-01-01

    Tyrosine kinase growth factor receptors (TKGFRs) play an important role in the progression of cancer. A variety of studies have investigated the clinicopathologic correlation of these receptors and their influences on patient survival in different types of cancer. As the members of TKGFRs, the biomarkers c-MET, epidermal growth factor receptor (EGFR), and human epidermal growth factor receptor 2 (HER-2) have been extensively investigated in biliary tract cancer (BTC). However, their prognostic value is still controversial. Our study aimed to evaluate the prognostic significance of the three markers in BTC patients based on the published studies. The correlation between high expression of these markers and clinical parameters or overall survival (OS) has been assumed in this paper. Including PubMed, EMBASE, China National Knowledge Infrastructure, and Springer, a comprehensive search for the related literature published in Chinese and English has been done. Finally, 31 studies were selected in our research. Surprisingly, the meta-analysis indicated that HER-2 high expression was not correlated with age, gender, primary tumor, tumor node metastasis (TNM) stage, lymph node status, and differentiation. We also found that EGFR high expression was not associated with the parameters, such as age, gender, TNM stage, differentiation, or lymph node status. c-MET high-expression was not associated with age, differentiation, gender, TNM stage, or lymph node status. In addition, our study showed that HER-2, EGFR, and c-MET high expression had an adverse influence on OS in BTC, the pooled hazard ratio for HER-2, EGFR, and c-MET was statistically significant. The present meta-analysis indicated that EGFR and HER-2 high expression have little impact on OS in patients with BTC while c-MET high expression influenced OS in patients with BTC to a large extent. However, c-MET, EGFR, and HER-2 expression did not show any correlation with those clinical parameters. c-MET may be a

  10. Impaired hair growth and wound healing in mice lacking thyroid hormone receptors.

    Science.gov (United States)

    Contreras-Jurado, Constanza; García-Serrano, Laura; Martínez-Fernández, Mónica; Ruiz-Llorente, Lidia; Paramio, Jesus M; Aranda, Ana

    2014-01-01

    Both clinical and experimental observations show that the skin is affected by the thyroidal status. In hypothyroid patients the epidermis is thin and alopecia is common, indicating that thyroidal status might influence not only skin proliferation but also hair growth. We demonstrate here that the thyroid hormone receptors (TRs) mediate these effects of the thyroid hormones on the skin. Mice lacking TRα1 and TRβ (the main thyroid hormone binding isoforms) display impaired hair cycling associated to a decrease in follicular hair cell proliferation. This was also observed in hypothyroid mice, indicating the important role of the hormone-bound receptors in hair growth. In contrast, the individual deletion of either TRα1 or TRβ did not impair hair cycling, revealing an overlapping or compensatory role of the receptors in follicular cell proliferation. In support of the role of the receptors in hair growth, TRα1/TRβ-deficient mice developed alopecia after serial depilation. These mice also presented a wound-healing defect, with retarded re-epithelialization and wound gaping, associated to impaired keratinocyte proliferation. These results reinforce the idea that the thyroid hormone nuclear receptors play an important role on skin homeostasis and suggest that they could be targets for the treatment of cutaneous pathologies.

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

    International Nuclear Information System (INIS)

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

    1985-01-01

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

  12. ErbB2 resembles an autoinhibited invertebrate epidermal growth factor receptor

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-09-25

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

  13. Requirement of tyrosine residues 333 and 338 of the growth hormone (GH) receptor for selected GH-stimulated function

    DEFF Research Database (Denmark)

    Lobie, P E; Allevato, G; Norstedt, G

    1995-01-01

    We have examined the involvement of tyrosine residues 333 and 338 of the growth hormone (GH) receptor in the cellular response to GH. Stable Chinese hamster ovary (CHO) cell clones expressing a receptor with tyrosine residues at position 333 and 338 of the receptor substituted for phenylalanine (...

  14. Lack of the type III epidermal growth factor receptor mutation in colorectal cancer

    DEFF Research Database (Denmark)

    Spindler, Karen-Lise Garm; Olsen, Dorte A.; Nielsen, Jens Nederby

    2006-01-01

    BACKGROUND: Epidermal growth factor receptor (EGFR) analysis by traditional immunohistochemistry does not provide clinicians with a reliable tool for the selection of patients to EGFR-targeted treatment in colorectal cancer (CRC). Alternative methods and further understanding of the EGFR signalin...

  15. Imaging Diagnostic and Therapeutic Targets : Human Epidermal Growth Factor Receptor 2

    NARCIS (Netherlands)

    Gebhart, Geraldine; Flamen, Patrick; Vries, de Elisabeth G. E.; Jhaveri, Komal; Wimana, Zena

    2016-01-01

    Since the approval of trastuzumab, a humanized monoclonal antibody against the extracellular domain of human epidermal growth factor receptor 2 (HER2), 3 other HER2-targeting agents have gained regulatory approval: lapatinib, pertuzumab, and trastuzumab-emtansine. These agents have revolutionized

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

    DEFF Research Database (Denmark)

    Christensen, Claus; Lauridsen, Jes B; Berezin, Vladimir

    2006-01-01

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

  17. Nectin-1 binds and signals through the fibroblast growth factor receptor

    DEFF Research Database (Denmark)

    Bojesen, Kirsten Borup; Clausen, Ole; Rohde, Kristian

    2012-01-01

    protein and induced neurite outgrowth in primary cultures of hippocampal and cerebellar granule neurons, an effect abolished by treatment with the fibroblast growth factor receptor (FGFR) inhibitor SU5402, or by transfection with a dominant-negative FGFR1 construct. We showed by surface plasmon resonance...

  18. Immunomodulator CD200 promotes neurotrophic activity by interacting with and activating the fibroblast growth factor receptor

    DEFF Research Database (Denmark)

    Pankratova, Stanislava; Björnsdóttir, Halla; Christensen, Claus

    2016-01-01

    in the suppression of microglia activation. We for the first time demonstrated that CD200 can interact with and transduce signaling through activation of the fibroblast growth factor receptor (FGFR), thereby inducing neuritogenesis and promoting neuronal survival in primary neurons. CD200-induced FGFR...

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

    DEFF Research Database (Denmark)

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

    2010-01-01

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

  20. Cytoplasmic sequences of the growth hormone receptor necessary for signal transduction

    DEFF Research Database (Denmark)

    Goujon, L; Allevato, G; Simonin, G

    1994-01-01

    To study structure-function relationships of the growth hormone (GH) receptor (GHR), two functional systems have been developed. CHO cells were transiently cotransfected with the cDNA encoding the full-length rat GHR and with a construct consisting of the 5' flanking region of one of two GH...

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

    DEFF Research Database (Denmark)

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

    2008-01-01

    KIT is a member of the tyrosine kinase family of growth factor receptors which is expressed on a variety of haematopoietic cells including mast cells. Stem cell factor (SCF)-dependent activation of KIT is critical for mast cell homeostasis and function. However, when KIT is inappropriately activa...

  2. Domains of the growth hormone receptor required for association and activation of JAK2 tyrosine kinase

    DEFF Research Database (Denmark)

    VanderKuur, J A; Wang, X; Zhang, L

    1994-01-01

    Growth hormone (GH) has recently been shown to activate the GH receptor (GHR)-associated tyrosine kinase JAK2. In the present study, regions of the GHR required for JAK2 association with GHR were identified. GH-dependent JAK2 association with GHR was detected in Chinese hamster ovary (CHO) cells...

  3. The growth-defense pivot: Crisis management in plants mediated by LRR-RK surface receptors

    Science.gov (United States)

    Belkhadir, Youssef; Yang, Li; Hetzel, Jonathan; Dangl, Jeffery L.; Chory, Joanne

    2014-01-01

    Plants must adapt to their environment and require mechanisms for sensing their surroundings and responding appropriately. An expanded family of greater than 200 leucine-rich repeat receptor kinases (LRR-RKs) transduces fluctuating and often contradictory signals from the environment into changes in nuclear gene expression. Two LRR-RKs, BRASSINOSTEROID INSENSITIVE 1 (BRI1), a steroid receptor, and FLAGELLIN-SENSITIVE 2 (FLS2), an innate immune receptor that recognizes bacterial flagellin, act cooperatively to partition necessary growth-defense tradeoffs. BRI1 and FLS2 share common signaling components and slightly different activation mechanisms. BRI1 and FLS2 are paradigms for understanding signaling mechanisms of LRR-containing receptors in plants. PMID:25089011

  4. Human neural progenitors express functional lysophospholipid receptors that regulate cell growth and morphology

    Directory of Open Access Journals (Sweden)

    Callihan Phillip

    2008-12-01

    Full Text Available Abstract Background Lysophospholipids regulate the morphology and growth of neurons, neural cell lines, and neural progenitors. A stable human neural progenitor cell line is not currently available in which to study the role of lysophospholipids in human neural development. We recently established a stable, adherent human embryonic stem cell-derived neuroepithelial (hES-NEP cell line which recapitulates morphological and phenotypic features of neural progenitor cells isolated from fetal tissue. The goal of this study was to determine if hES-NEP cells express functional lysophospholipid receptors, and if activation of these receptors mediates cellular responses critical for neural development. Results Our results demonstrate that Lysophosphatidic Acid (LPA and Sphingosine-1-phosphate (S1P receptors are functionally expressed in hES-NEP cells and are coupled to multiple cellular signaling pathways. We have shown that transcript levels for S1P1 receptor increased significantly in the transition from embryonic stem cell to hES-NEP. hES-NEP cells express LPA and S1P receptors coupled to Gi/o G-proteins that inhibit adenylyl cyclase and to Gq-like phospholipase C activity. LPA and S1P also induce p44/42 ERK MAP kinase phosphorylation in these cells and stimulate cell proliferation via Gi/o coupled receptors in an Epidermal Growth Factor Receptor (EGFR- and ERK-dependent pathway. In contrast, LPA and S1P stimulate transient cell rounding and aggregation that is independent of EGFR and ERK, but dependent on the Rho effector p160 ROCK. Conclusion Thus, lysophospholipids regulate neural progenitor growth and morphology through distinct mechanisms. These findings establish human ES cell-derived NEP cells as a model system for studying the role of lysophospholipids in neural progenitors.

  5. The nerve growth factor and its receptors in airway inflammatory diseases.

    Science.gov (United States)

    Freund-Michel, V; Frossard, N

    2008-01-01

    The nerve growth factor (NGF) belongs to the neurotrophin family and induces its effects through activation of 2 distinct receptor types: the tropomyosin-related kinase A (TrkA) receptor, carrying an intrinsic tyrosine kinase activity in its intracellular domain, and the receptor p75 for neurotrophins (p75NTR), belonging to the death receptor family. Through activation of its TrkA receptor, NGF activates signalling pathways, including phospholipase Cgamma (PLCgamma), phosphatidyl-inositol 3-kinase (PI3K), the small G protein Ras, and mitogen-activated protein kinases (MAPK). Through its p75NTR receptor, NGF activates proapoptotic signalling pathways including the MAPK c-Jun N-terminal kinase (JNK), ceramides, and the small G protein Rac, but also activates pathways promoting cell survival through the transcription factor nuclear factor-kappaB (NF-kappaB). NGF was first described by Rita Levi-Montalcini and collaborators as an important factor involved in nerve differentiation and survival. Another role for NGF has since been established in inflammation, in particular of the airways, with increased NGF levels in chronic inflammatory diseases. In this review, we will first describe NGF structure and synthesis and NGF receptors and their signalling pathways. We will then provide information about NGF in the airways, describing its expression and regulation, as well as pointing out its potential role in inflammation, hyperresponsiveness, and remodelling process observed in airway inflammatory diseases, in particular in asthma.

  6. Growth hormone maintains its own receptors in rat adipocytes.

    Science.gov (United States)

    Grichting, G; Goodman, H M

    1986-08-01

    Hypophysectomy decreased the capacity of adipocytes isolated from epididymal fat to bind [125I]human GH [( 125I]hGH) specifically without changing the apparent affinity for hGH. Specific binding of hGH by adipocytes of both normal and hypophysectomized rats appeared saturated when incubated with 75-80 ng/ml or higher concentrations of GH regardless of whether binding was studied for 2 h at 37 C or for 16 h at 0 C. Maximum binding of hGH by normal adipocytes was approximately 0.45 ng/10(6) cells, and that by adipocytes of hypophysectomized rats ranged from 0.15-0.25 ng/10(6) cells. In cells of both normal and hypophysectomized rats, only 25-30% of the hormone specifically bound at 37 was removed by digestion with trypsin, and about 75% was displaced by incubation with 5 M magnesium chloride, suggesting that these adipocytes internalized a significant fraction of bound hormone and that hypophysectomy did not alter the extent of internalization. Previously bound hormone was lost from normal adipocytes with a half-time of about 32 min and from adipocytes of hypophysectomized rats with a half-time of about 45 min, suggesting that hypophysectomy slowed the rate of processing bound hormone. To determine which pituitary hormone(s) might be required to maintain GH binding, we measured the binding of [125I]hGH at 3 or 30 ng/ml by fat cells prepared from hypophysectomized rats after various treatment regimens. Administration of bovine GH ip at a dose of 10 micrograms/rat every 4 h for 24 h doubled the binding of [125I]hGH by adipocytes prepared 4 h after the last injection. Similar results were obtained in fat cells examined 4 h after only one injection of 60 micrograms bovine GH to rats hypophysectomized 2-4 weeks previously. When binding was measured 16-24 h after GH administration, there was no apparent effect on restoration of binding even after treatment with 100 micrograms GH/day for up to 6 days, suggesting that the effects of GH in maintaining receptor number are

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

    DEFF Research Database (Denmark)

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

    1991-01-01

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

  8. Positron emission mammography: correlation of estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2 status and 18F-FDG.

    Science.gov (United States)

    Wang, Carolyn L; MacDonald, Lawrence R; Rogers, James V; Aravkin, Aleksandr; Haseley, David R; Beatty, J David

    2011-08-01

    The study objective was to assess the correlation between (18)F-FDG uptake values on positron emission mammography (PEM), expressed as maximum uptake value and lesion-to-background ratio, and receptor status (i.e., estrogen receptor [ER], progesterone receptor [PR], and human epidermal growth factor receptor 2 [HER2]), tumor histology, and tumor grade. We also evaluated for the correlation between maximum uptake value on PEM and maximum uptake value on a whole-body PET/CT. We retrospectively reviewed our database for patients with newly diagnosed breast cancer who were referred for PEM between June 2007 and September 2009. A subset of patients also underwent a whole-body PET/CT scan. The original pathology reports were reviewed to establish the histologic type, grade, and receptor status. The study involved 98 patients with 100 lesions. ER-negative tumors and PR-negative tumors had significantly higher mean lesion-to-background ratio than did their respective receptor-positive tumors (p = 0.02). Triple-negative tumors (i.e., ER-negative, PR-negative, and HER2-negative tumors) had statistically higher mean lesion-to-background ratio than did ER-positive PR-positive HER2-negative tumors (p = 0.04). Infiltrating ductal carcinomas had significantly higher PEM FDG uptake values than did infiltrating lobular carcinomas (p = 0.02-0.04). Breast tumors with higher histologic grade also had significantly higher PEM FDG uptake values than did those with lower grade (p = 0.03 and p PEM uptake values. This study shows a correlation between PEM FDG uptake values and the prognostic factors that have been shown to predict breast cancer survival.

  9. The SOCS2 Ubiquitin Ligase Complex Regulates Growth Hormone Receptor Levels

    DEFF Research Database (Denmark)

    Vesterlund, Mattias; Zadjali, Fahad; Persson, Torbjörn

    2011-01-01

    Growth Hormone is essential for the regulation of growth and the homeostatic control of intermediary metabolism. GH actions are mediated by the Growth Hormone Receptor; a member of the cytokine receptor super family that signals chiefly through the JAK2/STAT5 pathway. Target tissue responsiveness......, a phenotype that is dependent on endogenous GH secretion. SOCS2 is a GH-stimulated, STAT5b-regulated gene that acts in a negative feedback loop to downregulate GHR signalling. Since the biochemical basis for these actions is poorly understood, we studied the molecular function of SOCS2. We demonstrated...... of SOCS2 in in vitro experiments. We showed that SOCS2 regulates cellular GHR levels through direct ubiquitination and in a proteasomally dependent manner. We also confirmed the importance of the SOCS-box for the proper function of SOCS2. Finally, we identified two phosphotyrosine residues in the GHR...

  10. The ligand specificities of the insulin receptor and the insulin-like growth factor I receptor reside in different regions of a common binding site

    Energy Technology Data Exchange (ETDEWEB)

    Kjeldsen, T.; Andersen, A.S.; Wiberg, F.C.; Rasmussen, J.S.; Schaeffer, L.; Balschmidt, P.; Moller, K.B.; Moller, N.P.H. (Novo Nordisk, Bagsvaerd (Denmark))

    1991-05-15

    To identify the region(s) of the insulin receptor and the insulin-like growth factor I (IGF-I) receptor responsible for ligand specificity (high-affinity binding), expression vectors encoding soluble chimeric insulin/IGF-I receptors were prepared. The chimeric receptors were expressed in mammalian cells and partially purified. Binding studies revealed that a construct comprising an IGF-I receptor in which the 68 N-terminal amino acids of the insulin receptor {alpha}-subunit had replaced the equivalent IGF-I receptor segment displayed a markedly increased affinity for insulin. In contrast, the corresponding IGF-I receptor sequence is not critical for high-affinity IGF-I binding. It is shown that part of the cysteine-rich domain determines IGF-I specificity. The authors have previously shown that exchanging exons 1, 2, and 3 of the insulin receptor with the corresponding IGF-I receptor sequence results in loss of high affinity for insulin and gain of high affinity for IGF-I. Consequently, it is suggested that the ligand specificities of the two receptors (i.e., the sequences that discriminate between insulin and IGF-I) reside in different regions of a binding site with common features present in both receptors.

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

    International Nuclear Information System (INIS)

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

    2005-01-01

    The calcium-sensing receptor (CaR) is a G-protein-coupled receptor that is activated by extracellular calcium (Ca o 2+ ). Rat-1 fibroblasts have been shown to proliferate and increase ERK activity in response to elevation of [Ca 2+ ] 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 o 2+ . Furthermore, we show that AG1478 acts downstream or separately from G protein subunit activation of phospholipase C. AG1478 significantly inhibits Ca o 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 o 2+ . This is consistent with the known expression of TGFα by Rat-1 cells. These results indicate that EGFR transactivation is an important component of the CaR-mediated response to increased Ca o 2+ in Rat-1 fibroblasts and most likely involves CaR-mediated induction of regulated proteolysis and ligand shedding

  12. Regulation of endocrine and paracrine sources of insulin-like growth factors and growth hormone receptor during compensatory growth in hybrid striped bass (Morone chrysops x Morone saxatilis)

    DEFF Research Database (Denmark)

    Picha, Matthew E; Turano, Marc J; Tipsmark, Christian K

    2008-01-01

    Compensatory growth (CG) is a period of growth acceleration that exceeds normal rates after animals are alleviated of certain growth-stunting conditions. In hybrid striped bass (HSB, Morone chrysops x M. saxatilis), 3 weeks of complete feed restriction results in a catabolic state that, when...... relieved, renders a subsequent phase of CG. The catabolic state was characterized by depressed levels of hepatic Type I and II GH receptor (Ghr1, Ghr2) and insulin-like growth factor-I (Igf-I) mRNA, along with considerable decreases in plasma IGF-I. The state of catabolism also resulted in significant...... declines in hepatic Igf-II mRNA and in circulating 40kDa IGF binding protein (IGFBP). Skeletal muscle expression of Ghr2 mRNA was significantly increased. Upon realimentation, specific growth rates (SGR) were significantly higher than sized-matched controls, indicating a period of CG. Hepatic Ghr1, Ghr2...

  13. Epidermal growth factor receptor structural alterations in gastric cancer

    International Nuclear Information System (INIS)

    Moutinho, Cátia; Mateus, Ana R; Milanezi, Fernanda; Carneiro, Fátima; Seruca, Raquel; Suriano, Gianpaolo

    2008-01-01

    EGFR overexpression has been described in many human tumours including gastric cancer. In NSCLC patients somatic EGFR mutations, within the kinase domain of the protein, as well as gene amplification were associated with a good clinical response to EGFR inhibitors. In gastric tumours data concerning structural alterations of EGFR remains controversial. Given its possible therapeutic relevance, we aimed to determine the frequency and type of structural alterations of the EGFR gene in a series of primary gastric carcinomas. Direct sequencing of the kinase domain of the EGFR gene was performed in a series of 77 primary gastric carcinomas. FISH analysis was performed in 30 cases. Association studies between EGFR alterations and the clinical pathological features of the tumours were performed. Within the 77 primary gastric carcinomas we found two EGFR somatic mutations and several EGFR polymorphisms in exon 20. Six different intronic sequence variants of EGFR were also found. Four gastric carcinomas showed balanced polysomy or EGFR gene amplification. We verified that gastric carcinoma with alterations of EGFR (somatic mutations or copy number variation) showed a significant increase of tumour size (p = 0.0094) in comparison to wild-type EGFR carcinomas. We demonstrate that EGFR structural alterations are rare in gastric carcinoma, but whenever present, it leads to tumour growth. We considered that searching for EGFR alterations in gastric cancer is likely to be clinically important in order to identify patients susceptible to respond to tyrosine kinase inhibitors

  14. Hispolon inhibits the growth of estrogen receptor positive human breast cancer cells through modulation of estrogen receptor alpha

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Eun Hyang; Jang, Soon Young; Cho, In-Hye [Department of Pharmacy, Graduate School, Kyung Hee University, 26 Kyungheedae-ro, Dongdaemun-gu, Seoul 130-701 (Korea, Republic of); Hong, Darong [Department of Life and Nanopharmaceutical Science, Graduate School, Kyung Hee University, 26 Kyungheedae-ro, Dongdaemun-gu, Seoul 130-701 (Korea, Republic of); Jung, Bom; Park, Min-Ju [Department of Pharmacy, Graduate School, Kyung Hee University, 26 Kyungheedae-ro, Dongdaemun-gu, Seoul 130-701 (Korea, Republic of); Kim, Jong-Ho, E-mail: jonghokim@khu.ac.kr [Department of Pharmacy, Graduate School, Kyung Hee University, 26 Kyungheedae-ro, Dongdaemun-gu, Seoul 130-701 (Korea, Republic of)

    2015-08-07

    Human estrogen receptor α (ERα) is a nuclear transcription factor that is a major therapeutic target in breast cancer. The transcriptional activity of ERα is regulated by certain estrogen-receptor modulators. Hispolon, isolated from Phellinus linteus, a traditional medicinal mushroom called Sanghwang in Korea, has been used to treat various pathologies, such as inflammation, gastroenteric disorders, lymphatic diseases, and cancers. In this latter context, Hispolon has been reported to exhibit therapeutic efficacy against various cancer cells, including melanoma, leukemia, hepatocarcinoma, bladder cancer, and gastric cancer cells. However, ERα regulation by Hispolon has not been reported. In this study, we investigated the effects of Hispolon on the growth of breast cancer cells. We found that Hispolon decreased expression of ERα at both mRNA and the protein levels in MCF7 and T47D human breast cancer cells. Luciferase reporter assays showed that Hispolon decreased the transcriptional activity of ERα. Hispolon treatment also inhibited expression of the ERα target gene pS2. We propose that Hispolon, an anticancer drug extracted from natural sources, inhibits cell growth through modulation of ERα in estrogen-positive breast cancer cells and is a candidate for use in human breast cancer chemotherapy. - Highlights: • Hispolon decreased ERα expression at both mRNA and protein levels. • Hispolon decreased ERα transcriptional activity. • Hispolon treatment inhibited expression of ERα target gene pS2. • Shikonin is a candidate chemotherapeutic target in the treatment of human breast cancer.

  15. The role of endogenous epidermal growth factor receptor ligands in mediating corneal epithelial homeostasis.

    Science.gov (United States)

    Peterson, Joanne L; Phelps, Eric D; Doll, Mark A; Schaal, Shlomit; Ceresa, Brian P

    2014-05-01

    To provide a comprehensive study of the biological role and therapeutic potential of six endogenous epidermal growth factor receptor (EGFR) ligands in corneal epithelial homeostasis. Kinetic analysis and dose response curves were performed by using in vitro and in vivo wound-healing assays. Biochemical assays were used to determine receptor expression and activity. Human tears were collected and quantitatively analyzed by multianalyte profiling for endogenous EGFR ligands. Epidermal growth factor receptor ligands improved wound closure and activated EGFR, but betacellulin (BTC) was the most efficacious promoter of wound healing in vitro. In contrast, only epidermal growth factor (EGF) promoted wound healing in vivo. Human tears from 25 healthy individuals showed EGFR ligands at these average concentrations: EGF at 2053 ± 312.4 pg/mL, BTC at 207 ± 39.4 pg/mL, heparin-binding EGF at 44 ± 5.8 pg/mL, amphiregulin at 509 ± 28.8 pg/mL, transforming growth factor-α at 84 ± 19 pg/mL, and epiregulin at 52 ± 15 pg/mL. Under unwounded conditions, only EGF was present at concentrations near the ligand's Kd for the receptor, indicating it is the primary mediator of corneal epithelial homeostasis. Other ligands were present but at concentrations 11- to 7500-fold less their Kd, preventing significant ligand binding. Further, the high levels of EGF and its predicted binding preclude receptor occupancy by exogenous ligand and can explain the discrepancy between the in vitro and in vivo data. Therefore, therapeutic use of EGFR ligands may be unpredictable and impractical.

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

    International Nuclear Information System (INIS)

    Musgrove, Elizabeth A

    2004-01-01

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

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

    DEFF Research Database (Denmark)

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

    2017-01-01

    Receptor Tyrosine Kinase (RTK) signaling controls key aspects of cellular differentiation, proliferation, survival, metabolism, and migration. Deregulated RTK signaling also underlies many cancers. Glycosphingolipids (GSL) are essential elements of the plasma membrane. By affecting clustering...... hyperactivation is caused by absence of MacCer and not by GlcCer accumulation. We conclude that an early product in GSL biosynthesis, MacCer, prevents inappropriate activation of Insulin and Fibroblast Growth Factor Receptors in Drosophila glia. This article is protected by copyright. All rights reserved....

  18. Autoinhibition of the insulin-like growth factor I receptor by the juxtamembrane region.

    Science.gov (United States)

    Craddock, Barbara P; Cotter, Christopher; Miller, W Todd

    2007-07-10

    The juxtamembrane (JM) regions of several receptor tyrosine kinases are involved in autoinhibitory interactions that maintain the low basal activity of the receptors; mutations can give rise to constitutive kinase activity and signaling. In this report, we show that the JM region of the human insulin-like growth factor I receptor (IGF1R) plays a role in kinase regulation. We mutated JM residues that were conserved in this subfamily of receptor tyrosine kinases, and expressed and purified the cytoplasmic domains using the Sf9/baculovirus system. We show that a kinase-proximal mutation (Y957F) and (to a lesser extent) a mutation in the central part of the JM region (N947A) increase the autophosphorylation activity of the kinase. Steady-state kinetic measurements show the mutations cause an increase in V(max) for phosphorylation of peptide substrates. When the holoreceptors were expressed in fibroblasts derived from IGF1R-deficient mice, the Y957F mutation led to a large increase in basal and in IGF1-stimulated receptor autophosphorylation. Together, these data demonstrate that the JM region of IGF1R plays an important role in limiting the basal activity of the receptor.

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

    Directory of Open Access Journals (Sweden)

    Sean P Kennedy

    2016-08-01

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

  20. Polymorphism of growth hormone receptor (GHR gene in Holstein Friesian dairy cattle

    Directory of Open Access Journals (Sweden)

    Restu Misrianti

    2011-12-01

    Full Text Available Growth hormone gene have a critical role in the regulation of lactation, mammary gland development and growth process through its interaction with a specific receptor. Growth hormone (GH is an anabolic hormone which is synthesized and secreted by somatotrop cell in pituitary anterior lobe, and interacts with a specific receptor on the surface of the target cells. Growth hormone receptor (GHR has been suggested as candidate gene for traits related to milk production in Bovidae. The purpose of this study was to identify genetic polymorphism of the Growth Hormone Receptor (GHR genes in Holstein Friesian (HF cattle. Total of 353 blood samples were collected from five populations belonging to Cikole Dairy Cattle Breeding Station (BPPT-SP Cikole (88 samples, Pasir Kemis (95 samples, Cilumber (98 samples, Cipelang Livestock Embryo Center (BET Cipelang (40 samples, Singosari National Artificial Insemination Centre (BBIB Singosari (32 samples and 17 frozen semen samples from Lembang Artificial Insemination Center (BIB Lembang. Genomic DNAs were extracted by a standard phenol-chloroform protocol and amplified by a polymerase chain reaction (PCR techniques then PCR products were genotyped by the Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP methods. There were two allele dan three genotypes were found namely: allele A and G, Genotype AA, AG and GG repectively. Allele A frequency (0.70-0.82 relatively higher than allele G frequency (0.18-0.30. Chi square test show that on group of BET Cipelang, BIB Lembang and BBIB Singosari population were not significantly different (0.00-0.93, while on group of BET Cipelang, BIB Lembang dan BBIB Singosari population were significantly different (6.02-11.13. Degree of observed heterozygosity (Ho ranged from 0.13-0.42 and expected heterozygosity (He ranged from 0.29-0.42.

  1. Fibroblast Growth Factor 10-Fibroblast Growth Factor Receptor 2b Mediated Signaling Is Not Required for Adult Glandular Stomach Homeostasis

    Science.gov (United States)

    Sala, Frederic G.; Ford, Henri R.; Bellusci, Saverio; Grikscheit, Tracy C.

    2012-01-01

    The signaling pathways that are essential for gastric organogenesis have been studied in some detail; however, those that regulate the maintenance of the gastric epithelium during adult homeostasis remain unclear. In this study, we investigated the role of Fibroblast growth factor 10 (FGF10) and its main receptor, Fibroblast growth factor receptor 2b (FGFR2b), in adult glandular stomach homeostasis. We first showed that mouse adult glandular stomach expressed Fgf10, its receptors, Fgfr1b and Fgfr2b, and most of the other FGFR2b ligands (Fgf1, Fgf7, Fgf22) except for Fgf3 and Fgf20. Fgf10 expression was mesenchymal whereas FGFR1 and FGFR2 expression were mostly epithelial. Studying double transgenic mice that allow inducible overexpression of Fgf10 in adult mice, we showed that Fgf10 overexpression in normal adult glandular stomach increased epithelial proliferation, drove mucous neck cell differentiation, and reduced parietal and chief cell differentiation. Although a similar phenotype can be associated with the development of metaplasia, we found that Fgf10 overexpression for a short duration does not cause metaplasia. Finally, investigating double transgenic mice that allow the expression of a soluble form of Fgfr2b, FGF10's main receptor, which acts as a dominant negative, we found no significant changes in gastric epithelial proliferation or differentiation in the mutants. Our work provides evidence, for the first time, that the FGF10-FGFR2b signaling pathway is not required for epithelial proliferation and differentiation during adult glandular stomach homeostasis. PMID:23133671

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

    Directory of Open Access Journals (Sweden)

    Allison L Speer

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

  3. PTK787/ZK222584, an inhibitor of vascular endothelial growth factor receptor tyrosine kinases, decreases glioma growth and vascularization.

    Science.gov (United States)

    Goldbrunner, Roland H; Bendszus, Martin; Wood, Jeanette; Kiderlen, Michael; Sasaki, Masato; Tonn, Jörg-Christian

    2004-08-01

    The aim of this study was to test the efficacy of PTK787/ZK222584, an inhibitor of vascular endothelial growth factor (VEGF) receptor tyrosine kinases, on VEGF-dependent glioma vascularization and growth. C6 rat glioma cells were transfected with VEGF(164) in a sense (V(+)) or antisense (V(-)) direction. Spheroids generated from V(+) or V(-) cells were implanted orthotopically into 60 rat brains. Expression of VEGF and fetal liver kinase-1 (VEGF receptor 2) was assessed immunohistochemically. Animals with V(+) gliomas received orally administered PTK787/ZK222584 on postoperative Day (POD) 1 to 12 or POD 7 to 12. Untreated animals served as negative controls, and animals with V(-) gliomas served as positive controls. Growth and vascularization were evaluated by magnetic resonance imaging and immunohistochemistry. Flk-1 expression was positive within tumor vessels in V(+) gliomas, whereas all C6 clones were negative for fetal liver kinase-1 in vitro. Early (POD 1-12) and delayed (POD 7-12) application of PTK787/ZK222584 in V(+) glioma-bearing animals resulted in a significant reduction of tumor size (71% and 36%, P new tool in malignant glioma therapy.

  4. Growth hormone signaling in human T47D breast cancer cells: potential role for a growth hormone receptor-prolactin receptor complex.

    Science.gov (United States)

    Xu, Jie; Zhang, Yue; Berry, Philip A; Jiang, Jing; Lobie, Peter E; Langenheim, John F; Chen, Wen Y; Frank, Stuart J

    2011-04-01

    GH receptor (GHR) and prolactin (PRL) receptor (PRLR) are structurally similar cytokine receptor superfamily members that are highly conserved among species. GH has growth-promoting and metabolic effects in various tissues in vertebrates, including humans. PRL is essential for regulation of lactation in mammals. Recent studies indicate that breast tissue bears GHR and PRLR and that both GH and PRL may impact development or behavior of breast cancer cells. An important facet of human GH (hGH) and human PRL (hPRL) biology is that although hPRL interacts only with hPRLR, hGH binds well to both hGHR and hPRLR. Presently, we investigated potential signaling effects of both hormones in the estrogen receptor- and progesterone receptor-positive human T47D breast cancer cell line. We found that this cell type expresses ample GHR and PRLR and responds well to both hGH and hPRL, as evidenced by activation of the Janus kinase 2/signal transducer and activator of transcription 5 pathway. Immunoprecipitation studies revealed specific GHR-PRLR association in these cells that was acutely enhanced by GH treatment. Although GH caused formation of disulfide-linked and chemically cross-linked GHR dimers in T47D cells, GH preferentially induced tyrosine phosphorylation of PRLR rather than GHR. Notably, both a GHR-specific ligand antagonist (B2036) and a GHR-specific antagonist monoclonal antibody (anti-GHR(ext-mAb)) failed to inhibit GH-induced signal transducer and activator of transcription 5 activation. In contrast, although the non-GHR-specific GH antagonist (G120R) and the PRL antagonist (G129R) individually only partially inhibited GH-induced activation, combined treatment with these two antagonists conferred greater inhibition than either alone. These data indicate that endogenous GHR and PRLR associate (possibly as a GHR-PRLR heterodimer) in human breast cancer cells and that GH signaling in these cells is largely mediated by the PRLR in the context of both PRLR-PRLR homodimers

  5. Prevalence of Epidermal Growth Factor Receptor Mutations in Patients with Non-Small Cell Lung Cancer in Turkish Population.

    Science.gov (United States)

    Güler Tezel, Gaye; Şener, Ebru; Aydın, Çisel; Önder, Sevgen

    2017-12-01

    Epidermal growth factor receptor mutation analysis in non-small cell lung cancer is important for selecting patients who will receive treatment with tyrosine kinase inhibitors. In this study, we aimed to investigate the prevalence of epidermal growth factor receptor mutations and mutation patterns in the Turkish population. We retrospectively reviewed molecular pathology reports of 959 cases with lung cancer analysed for epidermal growth factor receptor mutations. We analysed all four epidermal growth factor receptor exon mutations using a real-time polymerase chain reaction platform. In this study, the epidermal growth factor receptor mutation rate in the Turkish population was 16.7% (160 of 959). The epidermal growth factor receptor mutation frequency was significantly higher in women (37.1%, n=96) than in men (9.1%, n=64) (pmutation rate was higher in the adenocarcinoma histologic type (pmutations were older than those without mutations (p=0.003). The most frequent mutations were exon 19 deletions (48.8%, 78/160) and exon 21 L858R point mutations (38.1.1%, 61/160). We also detected compound mutation patterns in three cases (1.9%). The prevalence of epidermal growth factor receptor mutations in the Turkish population was slightly higher than that in the Caucasian population and lower than that in the East Asian population. The results of this study may provide guidance in personalized therapy of non-small cell lung cancer in the Turkish population.

  6. Growth hormone (GH)-independent dimerization of GH receptor by a leucine zipper results in constitutive activation

    DEFF Research Database (Denmark)

    Behncken, S N; Billestrup, Nils; Brown, R

    2000-01-01

    Growth hormone initiates signaling by inducing homodimerization of two GH receptors. Here, we have sought to determine whether constitutively active receptor can be created in the absence of the extracellular domain by substituting it with high affinity leucine zippers to create dimers of the gro......Growth hormone initiates signaling by inducing homodimerization of two GH receptors. Here, we have sought to determine whether constitutively active receptor can be created in the absence of the extracellular domain by substituting it with high affinity leucine zippers to create dimers...

  7. Epidermal growth factor receptor and cancer: control of oncogenic signalling by endocytosis

    DEFF Research Database (Denmark)

    Grandal, Michael Vibo; Madshus, I.H.

    2008-01-01

    The epidermal growth factor receptor (EGFR) and other members of the EGFR/ErbB receptor family of receptor tyrosine kinases (RTKs) are important regulators of proliferation, angiogenesis, migration, tumorigenesis and metastasis. Overexpression, mutations, deletions and production of autocrine...... has been described, lysosomal degradation upon ligand-induced endocytosis seems to play the major role in EGFR down-regulation. Preclinical and clinical data have demonstrated that EGFR is a central player in cancer, especially in carcinomas, some brain tumours and in non-small cell lung cancer....... Such studies have further validated EGFR as an important molecular target in cancer treatment. This review focuses on mechanisms involved in ligand-induced EGFR activation and endocytic down-regulation. A better understanding of EGFR biology should allow development of more tumour-selective therapeutic...

  8. GLP-1/Exendin-4 induces β-cell proliferation via the epidermal growth factor receptor.

    Science.gov (United States)

    Fusco, Joseph; Xiao, Xiangwei; Prasadan, Krishna; Sheng, Qingfeng; Chen, Congde; Ming, Yung-Ching; Gittes, George

    2017-08-22

    Exendin-4 is a long acting glucagon-like peptide 1 (GLP-1) analogue that is an agonist for the GLP-1 receptor, a G-protein coupled receptor (GPCR). Exendin-4 is used to clinically improve glucose tolerance in diabetic patients due to its ability to enhance insulin secretion. In rodents, and possibly in humans, exendin-4 can stimulate β-cell proliferation. The exact mechanism of action to induce β-cell proliferation is not well understood. Here, using a β-cell specific epidermal growth factor receptor (EGFR) null mouse, we show that exendin-4 induced an increase in proliferation and β-cell mass through EGFR. Thus, our study sheds light on the role of EGFR signaling in the effects of exendin-4 on the control of blood glucose metabolism and β-cell mass.

  9. Cardio-oncology Related to Heart Failure: Epidermal Growth Factor Receptor Target-Based Therapy.

    Science.gov (United States)

    Kenigsberg, Benjamin; Jain, Varun; Barac, Ana

    2017-04-01

    Cancer therapy targeting the epidermal growth factor receptor (EGFR)/erythroblastic leukemia viral oncogene B (ErbB)/human EGFR receptor (HER) family of tyrosine kinases has been successfully used in treatment of several malignancies. The ErbB pathways play a role in the maintenance of cardiac homeostasis. This article summarizes current knowledge about EGFR/ErbB/HER receptor-targeted cancer therapeutics focusing on their cardiotoxicity profiles, molecular mechanisms, and implications in clinical cardio-oncology. The article discusses challenges in predicting, monitoring, and treating cardiac dysfunction and heart failure associated with ErbB-targeted cancer therapeutics and highlights opportunities for researchers and clinical investigators. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. Morpholino-Mediated Isoform Modulation of Vascular Endothelial Growth Factor Receptor-2 (VEGFR2) Reduces Colon Cancer Xenograft Growth

    Energy Technology Data Exchange (ETDEWEB)

    Stagg, Brian C., E-mail: briancstagg@gmail.com; Uehara, Hironori; Lambert, Nathan; Rai, Ruju; Gupta, Isha; Radmall, Bryce; Bates, Taylor; Ambati, Balamurali K. [John A Moran Eye Center, University of Utah, Salt Lake City, UT, 65 Mario Capecchi Drive, Salt Lake City, UT 84132 (United States)

    2014-11-26

    Angiogenesis plays a key role in tumor growth. Vascular endothelial growth factor (VEGF) is a pro-angiogenic that is involved in tumor angiogenesis. When VEGF binds to membrane-bound vascular endothelial growth factor receptor 2 (mVEGFR2), it promotes angiogenesis. Through alternative polyadenylation, VEGFR2 is also expressed in a soluble form (sVEGFR2). sVEGFR2 sequesters VEGF and is therefore anti-angiogenic. The aim of this study was to show that treatment with a previously developed and reported antisense morpholino oligomer that shifts expression from mVEGFR2 to sVEGFR2 would lead to reduced tumor vascularization and growth in a murine colon cancer xenograft model. Xenografts were generated by implanting human HCT-116 colon cancer cells into the flanks of NMRI nu/nu mice. Treatment with the therapeutic morpholino reduced both tumor growth and tumor vascularization. Because the HCT-116 cells used for the experiments did not express VEGFR2 and because the treatment morpholino targeted mouse rather than human VEGFR2, it is likely that treatment morpholino was acting on the mouse endothelial cells rather than directly on the tumor cells.

  11. Successful human epidermal growth receptor 2-targeted therapy beyond disease progression for extramammary Paget's disease.

    Science.gov (United States)

    Watanabe, Satomi; Takeda, Masayuki; Takahama, Takayuki; Iwasa, Tsutomu; Tsurutani, Junji; Tanizaki, Junko; Shimizu, Toshio; Sakai, Kazuko; Wada, Yoshitaka; Isogai, Noritaka; Nishio, Kazuto; Nakagawa, Kazuhiko

    2016-06-01

    Extramammary Paget's disease is a malignant intraepithelial carcinoma, which constitutes less than 1 % of all vulvar malignancies. Surgical resection is the first treatment of choice and standard chemotherapy has not been established for advanced or recurrent disease. Experimental and clinical studies have identified human epidermal growth receptor 2 as a potential therapeutic target. A 63-year-old male was referred for recurrent extramammary Paget's disease after surgery. Human epidermal growth receptor 2 was shown to be overexpressed and amplified by immunohistochemical analysis and fluorescence in situ hybridization analysis, respectively. After two cycles of trastuzumab monotherapy, all lymph node metastases decreased in size. However, he experienced recurrence in the lymph nodes during the seven courses of trastuzumab. As a subsequent treatment, trastuzumab was administered in combination with docetaxel and pertuzumab; clinical response was sustained for 12 months without significant adverse events.

  12. Differential Role of Insulin/IGF-1 Receptor Signaling in Muscle Growth and Glucose Homeostasis

    Directory of Open Access Journals (Sweden)

    Brian T. O’Neill

    2015-05-01

    Full Text Available Insulin and insulin-like growth factor 1 (IGF-1 are major regulators of muscle protein and glucose homeostasis. To determine how these pathways interact, we generated mice with muscle-specific knockout of IGF-1 receptor (IGF1R and insulin receptor (IR. These MIGIRKO mice showed >60% decrease in muscle mass. Despite a complete lack of insulin/IGF-1 signaling in muscle, MIGIRKO mice displayed normal glucose and insulin tolerance. Indeed, MIGIRKO mice showed fasting hypoglycemia and increased basal glucose uptake. This was secondary to decreased TBC1D1 resulting in increased Glut4 and Glut1 membrane localization. Interestingly, overexpression of a dominant-negative IGF1R in muscle induced glucose intolerance in MIGIRKO animals. Thus, loss of insulin/IGF-1 signaling impairs muscle growth, but not whole-body glucose tolerance due to increased membrane localization of glucose transporters. Nonetheless, presence of a dominant-negative receptor, even in the absence of functional IR/IGF1R, induces glucose intolerance, indicating that interactions between these receptors and other proteins in muscle can impair glucose homeostasis.

  13. The nuclear receptor DAF-12 regulates nutrient metabolism and reproductive growth in nematodes.

    Directory of Open Access Journals (Sweden)

    Zhu Wang

    2015-03-01

    Full Text Available Appropriate nutrient response is essential for growth and reproduction. Under favorable nutrient conditions, the C. elegans nuclear receptor DAF-12 is activated by dafachronic acids, hormones that commit larvae to reproductive growth. Here, we report that in addition to its well-studied role in controlling developmental gene expression, the DAF-12 endocrine system governs expression of a gene network that stimulates the aerobic catabolism of fatty acids. Thus, activation of the DAF-12 transcriptome coordinately mobilizes energy stores to permit reproductive growth. DAF-12 regulation of this metabolic gene network is conserved in the human parasite, Strongyloides stercoralis, and inhibition of specific steps in this network blocks reproductive growth in both of the nematodes. Our study provides a molecular understanding for metabolic adaptation of nematodes to their environment, and suggests a new therapeutic strategy for treating parasitic diseases.

  14. Exon 3-deleted and full-length growth hormone receptor polymorphism frequencies in an Iranian population

    OpenAIRE

    Palizban, A.A.; Radmansorry, M.; Bozorgzad, M.

    2014-01-01

    The functional role of the exon 3 growth hormone receptor (d3GHR) polymorphism in human and its distributions in different populations is not clearly understood. The presence of full length growth hormone (flGHR) is the most important in metabolic risk factors. The aim of this study was to define the frequency distribution of d3GHR/full-length GHR in an Iranian population. The presence of the d3GHR polymorphism in healthy volunteers blood DNA (n=80, male=30 and female=50) was assessed by PCR ...

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

    Directory of Open Access Journals (Sweden)

    Zhong SHI

    2015-02-01

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

  16. Seminal Plasma Proteins as Androgen Receptor Coregulators Promote Prostate Cancer Growth

    Science.gov (United States)

    2014-10-01

    the presence of zinc was found to induce androgen-mediated PSA expression in AR-positive prostate cancer cells. Reportable Outcomes Ishiguro ...prostatectomy. Hum Pathol 43: 6 1991–2000, 2012. Appendix Ishiguro H, Izumi K, Zheng Y, Kashiwagi E, Kawahara T, Miyamoto H: Semenogelin I promotes...PROSTATE CANCER CELL GROWTH VIA FUNCTIONING AS AN ANDROGEN RECEPTOR COACTIVATOR AND PROTECTING AGAINST ZINC CYTOTOXICITY Hitoshi Ishiguro *, Baltimore

  17. NMR backbone assignments of the tyrosine kinase domain of human fibroblast growth factor receptor 1.

    Science.gov (United States)

    Vajpai, Navratna; Schott, Anne-Kathrin; Vogtherr, Martin; Breeze, Alexander L

    2014-04-01

    Members of the fibroblast growth factor receptor tyrosine kinase family (FGFR1-4) play an important role in many signalling cascades. Although tightly regulated, aberrant activity of these enzymes may lead to, or become features of, disease pathologies including cancer. FGFR isoforms have been the subject of drug discovery programmes, with a number of kinase-domain inhibitors in pre-clinical and clinical development. Here, we present the first (83% complete) backbone resonance assignments of apo-FGFR1 kinase.

  18. Conditional expression of constitutively active estrogen receptor α in chondrocytes impairs longitudinal bone growth in mice

    International Nuclear Information System (INIS)

    Ikeda, Kazuhiro; Tsukui, Tohru; Imazawa, Yukiko; Horie-Inoue, Kuniko; Inoue, Satoshi

    2012-01-01

    Highlights: ► Conditional transgenic mice expressing constitutively active estrogen receptor α (caERα) in chondrocytes were developed. ► Expression of caERα in chondrocytes impaired longitudinal bone growth in mice. ► caERα affects chondrocyte proliferation and differentiation. ► This mouse model is useful for understanding the physiological role of ERαin vivo. -- Abstract: Estrogen plays important roles in the regulation of chondrocyte proliferation and differentiation, which are essential steps for longitudinal bone growth; however, the mechanisms of estrogen action on chondrocytes have not been fully elucidated. In the present study, we generated conditional transgenic mice, designated as caERα ColII , expressing constitutively active mutant estrogen receptor (ER) α in chondrocytes, using the chondrocyte-specific type II collagen promoter-driven Cre transgenic mice. caERα ColII mice showed retardation in longitudinal growth, with short bone lengths. BrdU labeling showed reduced proliferation of hypertrophic chondrocytes in the proliferating layer of the growth plate of tibia in caERα ColII mice. In situ hybridization analysis of type X collagen revealed that the maturation of hypertrophic chondrocytes was impaired in caERα ColII mice. These results suggest that ERα is a critical regulator of chondrocyte proliferation and maturation during skeletal development, mediating longitudinal bone growth in vivo.

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

    International Nuclear Information System (INIS)

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

    1989-01-01

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

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

    International Nuclear Information System (INIS)

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

    1986-01-01

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

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

    International Nuclear Information System (INIS)

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

    1987-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Sufi Mary Thomas

    2005-04-01

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

  3. Mammographic features of calcifications in DCIS: correlation with oestrogen receptor and human epidermal growth factor receptor 2 status

    Energy Technology Data Exchange (ETDEWEB)

    Bae, Min Sun; Moon, Woo Kyung; Chang, Jung Min; Cho, Nariya [Seoul National University College of Medicine, Department of Radiology, Seoul (Korea, Republic of); Park, So Yeon; Won, Jae-Kyung; Jeon, Yoon-Kyung; Park, In Ae [Seoul National University College of Medicine, Department of Pathology, Seoul (Korea, Republic of); Moon, Hyeong-Gon; Han, Wonshik [Seoul National University College of Medicine, Department of Surgery, Seoul (Korea, Republic of)

    2013-08-15

    This study investigated the correlation of oestrogen receptor (ER) and human epidermal growth factor receptor 2 (HER2) status with the probability of malignancy (POM) of mammographic calcifications in ductal carcinoma in situ (DCIS). A total of 101 women (age range, 27-83 years) with pure DCIS that presented as mammographic calcifications were included. Three radiologists independently reviewed mammograms according to the BI-RADS lexicon and provided 100-point POM scores and a BI-RADS category. ER, HER2 and breast cancer subtypes were determined using immunohistochemistry (IHC) and fluorescence in situ hybridisation. Pairwise correlations between POM and IHC biomarker scores were calculated, and mammographic features were compared between breast cancer subtypes. HER2 level positively correlated with the POM score (P < 0.0001) and BI-RADS category (P < 0.0001), and ER level inversely correlated with the POM score (P < 0.013) and BI-RADS category (P < 0.010). Fine linear branching (P = 0.004) and segmental (P = 0.014) calcifications were significantly associated with HER2-positive cancers, and clustered calcifications were more frequently observed in ER-positive cancers (P = 0.014). HER2 status in DCIS correlated positively with the POM of mammographic calcifications, as determined by radiologists on the basis of the BI-RADS lexicon. (orig.)

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

    Science.gov (United States)

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

    2006-08-01

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

  5. Growth hormone (GH)-independent dimerization of GH receptor by a leucine zipper results in constitutive activation

    DEFF Research Database (Denmark)

    Behncken, S N; Billestrup, Nils; Brown, R

    2000-01-01

    Growth hormone initiates signaling by inducing homodimerization of two GH receptors. Here, we have sought to determine whether constitutively active receptor can be created in the absence of the extracellular domain by substituting it with high affinity leucine zippers to create dimers of the gro......Growth hormone initiates signaling by inducing homodimerization of two GH receptors. Here, we have sought to determine whether constitutively active receptor can be created in the absence of the extracellular domain by substituting it with high affinity leucine zippers to create dimers...... of the growth hormone receptor (GHR) signaling domain. The entire extracellular domain of the GHR was replaced by the hemagglutinin-tagged zipper sequence of either the c-Fos or c-Jun transcription factor (termed Fos-GHR and Jun-GHR, respectively). Transient transfection of Fos-GHR or Jun-GHR resulted...

  6. Regulation of insulin-like growth factor II receptors by growth hormone and insulin in rat adipocytes

    International Nuclear Information System (INIS)

    Loennroth, P.; Assmundsson, K.; Eden, S.; Enberg, G.; Gause, I.; Hall, K.; Smith, U.

    1987-01-01

    The acute and long-term effects of growth hormone (GH) on the binding of insulin-like growth factor II (IGF-II) were evaluated in adipose cells from hypophysectomized rats given replacement therapy with thyroxine and hydrocortisone and in cells from their sham-operated littermates. After the cells were incubated with insulin and/or GH, the recycling of 125 I-labeled IGF-II receptors was metabolically inhibited by treating the cells with KCN. IGF-II binding was 100 +/- 20% higher in cells from GH-deficient animals when compared with sham-operated controls. These GH-deficient cells also showed an increased sensitivity for insulin as compared with control cells (the EC 50 for insulin was 0.06 ng/ml in GH-deficient cells and 0.3 ng/ml in control cells.). However, the maximal incremental effect of insulin on IGH-II binding was reduced ≅ 27% by hypophysectomy. GH added to the incubation medium increased the number of IGF-II binding sites by 100 +/- 18% in cells from hypophysectomized animals. This increase was rapidly induced, but the time course was slower than that for the stimulatory effect of insulin. Half-maximal effect of GH on IGF-II binding was obtained at ≅ 30 ng/ml. Thus, GH added in vitro exerted a rapid insulin-like effect on the number of IGH-II receptors. GH also appears to play a regulating role for maintaining the cellular number of IGH-II receptors and, in addition, modulates the stimulatory effect of insulin on IGF-II binding

  7. Effect of β-nerve growth factor on differentiation of endothelial ...

    African Journals Online (AJOL)

    Enzyme-linked immunosorbent assay (ELISA) was conducted to detect the levels of vascular endothelial growth factor (VEGF), von Willebrand factor (vWF) and basic fibroblast growth factor (bFGF) in different rat EPC culture solutions. Western blot was performed to determine the expression of tyrosine kinase receptor A ...

  8. Growth Factor Receptors and Apoptosis Regulators: Signaling Pathways, Prognosis, Chemosensitivity and Treatment Outcomes of Breast Cancer

    Directory of Open Access Journals (Sweden)

    Siddik Sarkar

    2009-01-01

    Full Text Available Biomarkers of breast cancer are necessary for prognosis and prediction to chemotherapy. Prognostic biomarkers provide information regarding outcome irrespective of therapy, while predictive biomarkers provide information regarding response to therapy. Candidate prognostic biomarkers for breast cancers are growth factor receptors, steroid receptors, Ki-67, cyclins, urokinase plasminogen activator, p53, p21, pro- and anti-apoptotic factors, BRCA1 and BRCA2. But currently, the predictive markers are Estrogen and Progesterone receptors responding to endocrine therapy, and HER-2 responding to herceptin. But there are numerous breast cancer cases, where tamoxifen is ineffective even after estrogen receptor positivity. This lead to search of new prognostic and predictive markers and the number of potential markers is constantly increasing due to proteomics and genomics studies. However, most biomarkers individually have poor sensitivity or specificity, or other clinical value. It can be resolved by studying various biomarkers simultaneously, which will help in better prognosis and increasing sensitivity for chemotherapeutic agents. This review is focusing on growth factor receptors, apoptosis markers, signaling cascades, and their correlation with other associated biomarkers in breast cancers. As our knowledge regarding molecular biomarkers for breast cancer increases, prognostic indices will be developed that combine the predictive power of individual molecular biomarkers with specific clinical and pathologic factors. Rigorous comparison of these existing as well as emerging markers with current treatment selection is likely to see an escalation in an era of personalized medicines to ensure the breast cancer patients receive optimal treatment. This will also solve the treatment modalities and complications related to chemotherapeutic regimens.

  9. Transforming growth factor betas and their signaling receptors in human hepatocellular carcinoma.

    Science.gov (United States)

    Abou-Shady, M; Baer, H U; Friess, H; Berberat, P; Zimmermann, A; Graber, H; Gold, L I; Korc, M; Büchler, M W

    1999-03-01

    Transforming growth factor betas (TGF-betas) are multifunctional polypeptides that have been suggested to influence tumor growth. They mediate their functions via specific cell surface receptors (type I ALK5 and type II TGF-beta receptors). The aim of this study was to analyze the roles of the three TGF-betas and their signaling receptors in human hepatocellular carcinoma (HCC). HCC tissue samples were obtained from 18 patients undergoing partial liver resection. Normal liver tissues from 7 females and 3 males served as controls. The tissues for histological analysis were fixed in Bouin's solution and paraffin embedded. For RNA analysis, freshly obtained tissue samples were snap frozen in liquid nitrogen and stored at -80 degrees C until used. Northern blot analysis was used in normal liver and HCC to examine the expression of TGF-beta1, -beta2, -beta3 and their receptors: type I ALK5 (TbetaR-I ALK5), type II (TbetaR-II), and type III (TbetaR-III). Immunohistochemistry was performed to localize the corresponding proteins. All three TGF-betas demonstrated a marked mRNA overexpression in HCC in comparison with normal controls, whereas the levels of all three TGF-beta receptors showed no significant changes. Intense TGF-beta1, TGF-beta2, and TGF-beta3 immunostaining was found in hepatocellular carcinoma cells and in the perineoplastic stroma with immunohistochemistry, whereas no or mild immunostaining was present in the normal liver. For TbetaR-I ALK5 and TbetaR-II, the immunostaining in both HCC and normal liver was mild to moderate, with a slightly higher intensity in the normal tissues. The upregulation of TGF-betas in HCC suggests an important role for these isoforms in hepatic carcinogenesis and tumor progression. Moreover, the localization of the immunoreactivity in both malignant hepatocytes and stromal cells suggests that TGF-betas act via autocrine and paracrine pathways in this neoplasm.

  10. Leptin Antagonizes Peroxisome Proliferator-Activated Receptor-γ Signaling in Growth Plate Chondrocytes

    Directory of Open Access Journals (Sweden)

    Lai Wang

    2012-01-01

    Full Text Available Leptin is an obesity-associated cytokine-like hormone encoded by the ob gene. Recent studies reveal that leptin promotes proliferation and differentiation of chondrocytes, suggesting a peripheral role of leptin in regulating growth plate function. Peroxisome proliferator-activated receptor-γ (PPARγ is a transcriptional regulator of adipogenesis. Locally, PPARγ negatively regulates chondrogenic differentiation and terminal differentiation in the growth plate. The aim of this study was to test the hypothesis that leptin may suppress the inhibitory effects of PPARγ on growth plate chondrocytes. Chondrocytes were collected from distal femoral growth plates of newborn rats and were cultured in monolayer or cell pellets in the presence or absence of leptin and the PPARγ agonist ciglitazone. The results show that leptin attenuates the suppressive effects of PPARγ on chondrogenic differentiation and T3-mediated chondrocyte hypertrophy. Leptin treatment also leads to a mild downregulation of PPAR mRNA expression and a significant MAPK/ERK-dependent PPARγ phosphorylation at serine 112/82. Blocking MAPK/ERK function with PD98059 confirmed that leptin antagonizes PPARγ function in growth plate chondrocytes through the MAPK/ERK signaling pathway. Furthermore, leptin signaling in growth plate cells is also negatively modulated by activation of PPARγ, implying that these two signaling pathways are mutually regulated in growth plate chondrocytes.

  11. Distribution of epidermal growth factor receptors in rat tissues during embryonic skin development, hair formation, and the adult hair growth cycle

    DEFF Research Database (Denmark)

    Green, M R; Couchman, J R

    1984-01-01

    on the binding distribution of [125I]EGF, representing the tissue localization of available EGF receptors, during embryonic rat skin development including hair follicle formation and the adult hair growth cycle. At 16 days embryonic development a relatively low receptor density is seen over all the epidermal......In a previous study on neonatal rat skin (Green MR, Basketter DA, Couchman JR, Rees DA: Dev Biol 100:506-512, 1983) a close positive correlation was found between epidermal growth factor (EGF) receptor tissue distribution and areas of potential epithelial cell proliferation. We now report...... condensates marking the first stage of hair follicle development. This restricted and temporary loss of EGF receptors above these specialized mesenchymal condensates implies a role for the EGF receptor and possibly EGF or an EGF-like ligand in stimulating the epithelial downgrowth required for hair follicle...

  12. Opioid and nicotine receptors affect growth regulation of human lung cancer cell lines

    International Nuclear Information System (INIS)

    Maneckjee, R.; Minna, J.D.

    1990-01-01

    Using specific radioactively-labeled ligands, the authors find that lung cancer cell lines of diverse histologic types express multiple, high-affinity membrane receptors for μ, δ, and κ opioid agonists and for nicotine and α-bungarotoxin. These receptors are biologically active because cAMP levels decreased in lung cancer cells after opioid and nicotine application. Nicotine at concentrations found in the blood of smokers had no effect on in vitro lung cancer cell growth, whereas μ, δ, and κ opioid agonists at low concentrations inhibited lung cancer growth in vitro. They also found that lung cancer cells expressed various combinations of immunoreactive opioid peptides (β-endorphin, enkephalin, or dynorphin), suggesting the participation of opioids in a negative autocrine loop or tumor-suppressing system. Due to the almost universal exposure of patients with lung cancer to nicotine, they tested whether nicotine affected the response of lung cancer cell growth to opioids and found that nicotine at concentrations of 100-200 nM partially or totally reversed opioid-induced growth inhibition in 9/14 lung cancer cell lines. These in vitro results for lung cancer cells suggest that opioids could function as part of a tumor suppressor system and that nicotine can function to circumvent this system in the pathogenesis of lung cancer

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

    Directory of Open Access Journals (Sweden)

    Dan PU

    2013-11-01

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

  14. Opioid and nicotine receptors affect growth regulation of human lung cancer cell lines

    Energy Technology Data Exchange (ETDEWEB)

    Maneckjee, R.; Minna, J.D. (National Cancer Institute-Navy Medical Oncology Branch, Bethesda, MD (USA) Uniformed Services Univ. of the Health Sciences, Bethesda, MD (USA))

    1990-05-01

    Using specific radioactively-labeled ligands, the authors find that lung cancer cell lines of diverse histologic types express multiple, high-affinity membrane receptors for {mu}, {delta}, and {kappa} opioid agonists and for nicotine and {alpha}-bungarotoxin. These receptors are biologically active because cAMP levels decreased in lung cancer cells after opioid and nicotine application. Nicotine at concentrations found in the blood of smokers had no effect on in vitro lung cancer cell growth, whereas {mu}, {delta}, and {kappa} opioid agonists at low concentrations inhibited lung cancer growth in vitro. They also found that lung cancer cells expressed various combinations of immunoreactive opioid peptides ({beta}-endorphin, enkephalin, or dynorphin), suggesting the participation of opioids in a negative autocrine loop or tumor-suppressing system. Due to the almost universal exposure of patients with lung cancer to nicotine, they tested whether nicotine affected the response of lung cancer cell growth to opioids and found that nicotine at concentrations of 100-200 nM partially or totally reversed opioid-induced growth inhibition in 9/14 lung cancer cell lines. These in vitro results for lung cancer cells suggest that opioids could function as part of a tumor suppressor system and that nicotine can function to circumvent this system in the pathogenesis of lung cancer.

  15. Transferrin receptor regulates pancreatic cancer growth by modulating mitochondrial respiration and ROS generation

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Seung Min, E-mail: smjeong@catholic.ac.kr [Department of Biochemistry, College of Medicine, The Catholic University of Korea, Seoul 137-701 (Korea, Republic of); Institute for Aging and Metabolic Diseases, College of Medicine, The Catholic University of Korea, Seoul 137-701 (Korea, Republic of); Hwang, Sunsook; Seong, Rho Hyun [School of Biological Sciences and Institute of Molecular Biology and Genetics, Seoul National University, Seoul 151-742 (Korea, Republic of)

    2016-03-11

    The transferrin receptor (TfR1) is upregulated in malignant cells and its expression is associated with cancer progression. Because of its pre-eminent role in cell proliferation, TfR1 has been an important target for the development of cancer therapy. Although TfR1 is highly expressed in pancreatic cancers, what it carries out in these refractory cancers remains poorly understood. Here we report that TfR1 supports mitochondrial respiration and ROS production in human pancreatic ductal adenocarcinoma (PDAC) cells, which is required for their tumorigenic growth. Elevated TfR1 expression in PDAC cells contributes to oxidative phosphorylation, which allows for the generation of ROS. Importantly, mitochondrial-derived ROS are essential for PDAC growth. However, exogenous iron supplement cannot rescue the defects caused by TfR1 knockdown. Moreover, we found that TfR1 expression determines PDAC cells sensitivity to oxidative stress. Together, our findings reveal that TfR1 can contribute to the mitochondrial respiration and ROS production, which have essential roles in growth and survival of pancreatic cancer. - Highlights: • Pancreatic ductal adenocarcinoma (PDAC) exhibits an elevated transferrin receptor (TfR1) expression in comparison with non-transformed pancreatic cells. • TfR1 is required for PDAC growth by regulating mitochondrial respiration and ROS production. • TfR1 functions as a determinant of cell viability to oxidative stress in PDAC cells.

  16. Growth hormone, interferon-gamma, and leukemia inhibitory factor promoted tyrosyl phosphorylation of insulin receptor substrate-1

    DEFF Research Database (Denmark)

    Argetsinger, L S; Hsu, G W; Myers, M G

    1995-01-01

    The identification of JAK2 as a growth hormone (GH) receptor-associated, GH-activated tyrosine kinase has established tyrosyl phosphorylation as a signaling mechanism for GH. In the present study, GH is shown to stimulate tyrosyl phosphorylation of insulin receptor substrate 1 (IRS-1), the princi...... characterized insulin-like metabolic effects of GH observed in a variety of cell types....

  17. Overexpression of the tomato pollen receptor kinase LePRK1 rewires pollen tube growth to a blebbling mode

    Science.gov (United States)

    The tubular growth of a pollen tube cell is crucial for the sexual reproduction of flowering plants. LePRK1 is a pollen-specific and plasma membrane–localized receptor-like kinase from tomato (Solanum lycopersicum). LePRK1 interacts with another receptor, LePRK2, and with KINASE PARTNER PROTEIN (KPP...

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

    NARCIS (Netherlands)

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

    1990-01-01

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

  19. Requirement of tyrosine residues 333 and 338 of the growth hormone (GH) receptor for selected GH-stimulated function

    DEFF Research Database (Denmark)

    Lobie, P E; Allevato, G; Norstedt, G

    1995-01-01

    We have examined the involvement of tyrosine residues 333 and 338 of the growth hormone (GH) receptor in the cellular response to GH. Stable Chinese hamster ovary (CHO) cell clones expressing a receptor with tyrosine residues at position 333 and 338 of the receptor substituted for phenylalanine...... (CHO-GHR1-638 Y333F, Y338F) were generated by cDNA transfection. Compared with the wild type receptor the Y333F,Y338F mutant possessed normal high affinity ligand binding, hormone internalization, and ligand-induced receptor down-regulation. GH activation of mitogen-associated protein kinase was also...... similar in CHO clones expressing similar wild type and Y333F,Y338F receptor number. However, two GH-regulated cellular events (lipogenesis, and protein synthesis) were deficient in the tyrosine substituted receptor. In contrast, transcriptional regulation by GH (as evidenced by chloramphenicol...

  20. The effect of testosterone on androgen receptors and human penile growth.

    Science.gov (United States)

    Baskin, L S; Sutherland, R S; DiSandro, M J; Hayward, S W; Lipschutz, J; Cunha, G R

    1997-09-01

    Recent rat studies suggest that early exposure to exogenous testosterone accelerates the loss of androgen receptors and compromises eventual penile length. In humans we hypothesize that down regulation of the androgen receptor is not the mechanism that stops penile growth. To test this hypothesis we investigated the effects of androgen deprivation and supplementation on the developing human penis. A total of 15 normal human fetal penises at 7 to 19 weeks of gestation (mean plus or minus standard deviation 12 +/- 4.5) was divided in half sagittally. Specimens were grafted beneath the renal capsule of male athymic nude mice or nude rats. Three groups of host animals were prepared, including 10 with no testosterone that were castrated at grafting, 15 with testosterone and 5 with super testosterone in which 50 mg. testosterone propionate pellets were implanted subcutaneously at grafting. Each fetal penile specimen was its own control, since half was implanted into an intact animal and the other into a castrated or super testosterone host. Six weeks after grafting the specimens were analyzed for gross size (length), histology and expression of androgen receptors. All human fetal penile specimens grew from the nadir size and appeared as white exophytic growths on the surface of the host kidneys. Normal grafts were larger than castrate specimens (mean 6.9 +/- 2.1 versus 3.9 +/- 2.1 mm., p = 0.014). Mean length of the super testosterone specimens (7.3 +/- 2.3 mm.) was not significantly greater than that of normal specimens (p = 0.797). Histological analysis revealed that all specimens were composed of viable penile tissue. Cellular density of the castrate penises was approximately 2 times greater than that of the normal and super testosterone specimens (40.6 +/- 5.9 versus 25.1 +/- 2.8 cells per cm.2, p > 0.001), as calculated on enlarged micrographs. Supraphysiological doses of testosterone did not change the histology compared to controls. Immunohistochemical

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

    DEFF Research Database (Denmark)

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

    2000-01-01

    In order to improve prediction of hematopoietic recovery, we conducted a pilot study, analyzing the significance of growth factor receptor expression in autografts as well as endogenous growth factor levels in blood before, during and after stem cell transplantation. Three early acting (stem cell...

  2. Distribution of epidermal growth factor receptors in rat tissues during embryonic skin development, hair formation, and the adult hair growth cycle

    DEFF Research Database (Denmark)

    Green, M R; Couchman, J R

    1984-01-01

    condensates marking the first stage of hair follicle development. This restricted and temporary loss of EGF receptors above these specialized mesenchymal condensates implies a role for the EGF receptor and possibly EGF or an EGF-like ligand in stimulating the epithelial downgrowth required for hair follicle...... on the binding distribution of [125I]EGF, representing the tissue localization of available EGF receptors, during embryonic rat skin development including hair follicle formation and the adult hair growth cycle. At 16 days embryonic development a relatively low receptor density is seen over all the epidermal...... development. In the anagen hair bulb, receptors for EGF are detected over the outer root sheath and the epithelial cell layers at the base of the follicle and show a correlation with the areas of epithelial proliferation in the hair bulb. During the catagen and telogen phases of the hair cycle, receptors...

  3. Prognostic role of fibroblast growth factor receptor 2 in human solid tumors: A systematic review and meta-analysis.

    Science.gov (United States)

    Liu, Gang; Xiong, Disheng; Xiao, Rui; Huang, Zhengjie

    2017-06-01

    In the past decades, the oncogenic role of fibroblast growth factor receptor 2 has been demonstrated in a number of cancer types. However, studies have reported contradictory findings concerning the correlation between fibroblast growth factor receptor 2 expression and prognosis in solid tumors. To address this discrepancy, we performed a meta-analysis with 18 published studies (2975 patients) retrieved from PubMed, EMBASE, and Web of science. Data were extracted and computed into odds ratios. The results showed that fibroblast growth factor receptor 2 overexpression was significantly associated with decreased 3-year overall survival (odds ratio = 1.93, 95% confidence interval: 1.30-2.85, p = 0.001) and 5-year overall survival (odds ratio = 1.62, 95% confidence interval: 1.07-2.44, p = 0.02) in patients with solid tumors. Subgroup analysis revealed that high fibroblast growth factor receptor 2 expression was also associated with poor prognosis of gastric cancer, hepatocellular carcinoma, and esophageal cancer, but not correlated with pancreatic cancer. In conclusion, fibroblast growth factor receptor 2 overexpression is correlated with decreased survival in most solid tumors, suggesting that the expression status of fibroblast growth factor receptor 2 is a valuable prognostic biomarker and a novel therapeutic target in human solid tumors.

  4. Growth of a progesterone receptor-positive meningioma in a female patient with congenital adrenal hyperplasia.

    Science.gov (United States)

    O'Shea, T; Crowley, R K; Farrell, M; MacNally, S; Govender, P; Feeney, J; Gibney, J; Sherlock, M

    2016-01-01

    Meningioma growth has been previously described in patients receiving oestrogen/progestogen therapy. We describe the clinical, radiological, biochemical and pathologic findings in a 45-year-old woman with congenital adrenal hyperplasia secondary to a defect in the 21-hydroxylase enzyme who had chronic poor adherence to glucocorticoid therapy with consequent virilisation. The patient presented with a frontal headache and marked right-sided proptosis. Laboratory findings demonstrated androgen excess with a testosterone of 18.1 nmol/L (0-1.5 nmol) and 17-Hydroxyprogesterone >180 nmol/L (transsexual patients undergoing therapy with high-dose oestrogen and progestogens. Progesterone receptor positivity has been described previously in meningiomas. 17-Hydroxyprogesterone is elevated in CAH and has affinity and biological activity at the progesterone receptor. Therefore, we hypothesise that patients who have long-standing increased adrenal androgen precursor concentrations may be at risk of meningioma growth. Patients with long-standing CAH (particularly if not optimally controlled) may present with other complications, which may be related to long-standing elevated androgen or decreased glucocorticoid levels.Chronic poor control of CAH is associated with adrenal myelolipoma and adrenal rest tissue tumours.Meningiomas are sensitive to endocrine stimuli including progesterone, oestrogen and androgens as they express the relevant receptors.

  5. G Protein-Coupled Estrogen Receptor-Selective Ligands Modulate Endometrial Tumor Growth

    Directory of Open Access Journals (Sweden)

    Whitney K. Petrie

    2013-01-01

    Full Text Available Endometrial carcinoma is the most common cancer of the female reproductive tract. GPER/GPR30 is a 7-transmembrane spanning G protein-coupled receptor that has been identified as the third estrogen receptor, in addition to ERα and ERβ. High GPER expression is predictive of poor survival in endometrial and ovarian cancer, but despite this, the estrogen-mediated signaling pathways and specific estrogen receptors involved in endometrial cancer remain unclear. Here, employing ERα-negative Hec50 endometrial cancer cells, we demonstrate that GPER mediates estrogen-stimulated activation of ERK and PI3K via matrix metalloproteinase activation and subsequent transactivation of the EGFR and that ER-targeted therapeutic agents (4-hydroxytamoxifen, ICI182,780/fulvestrant, and Raloxifene, the phytoestrogen genistein, and the “ERα-selective” agonist propylpyrazole triol also function as GPER agonists. Furthermore, xenograft tumors of Hec50 cells yield enhanced growth with G-1 and estrogen, the latter being inhibited by GPER-selective pharmacologic antagonism with G36. These results have important implications with respect to the use of putatively ER-selective ligands and particularly for the widespread long-term use of “ER-targeted” therapeutics. Moreover, our findings shed light on the potential mechanisms of SERM/SERD side effects reported in many clinical studies. Finally, our results provide the first demonstration that pharmacological inhibition of GPER activity in vivo prevents estrogen-mediated tumor growth.

  6. Altered metabolism of growth hormone receptor mutant mice: a combined NMR metabonomics and microarray study.

    Directory of Open Access Journals (Sweden)

    Horst Joachim Schirra

    Full Text Available BACKGROUND: Growth hormone is an important regulator of post-natal growth and metabolism. We have investigated the metabolic consequences of altered growth hormone signalling in mutant mice that have truncations at position 569 and 391 of the intracellular domain of the growth hormone receptor, and thus exhibit either low (around 30% maximum or no growth hormone-dependent STAT5 signalling respectively. These mutations result in altered liver metabolism, obesity and insulin resistance. METHODOLOGY/PRINCIPAL FINDINGS: The analysis of metabolic changes was performed using microarray analysis of liver tissue and NMR metabonomics of urine and liver tissue. Data were analyzed using multivariate statistics and Gene Ontology tools. The metabolic profiles characteristic for each of the two mutant groups and wild-type mice were identified with NMR metabonomics. We found decreased urinary levels of taurine, citrate and 2-oxoglutarate, and increased levels of trimethylamine, creatine and creatinine when compared to wild-type mice. These results indicate significant changes in lipid and choline metabolism, and were coupled with increased fat deposition, leading to obesity. The microarray analysis identified changes in expression of metabolic enzymes correlating with alterations in metabolite concentration both in urine and liver. Similarity of mutant 569 to the wild-type was seen in young mice, but the pattern of metabolites shifted to that of the 391 mutant as the 569 mice became obese after six months age. CONCLUSIONS/SIGNIFICANCE: The metabonomic observations were consistent with the parallel analysis of gene expression and pathway mapping using microarray data, identifying metabolites and gene transcripts involved in hepatic metabolism, especially for taurine, choline and creatinine metabolism. The systems biology approach applied in this study provides a coherent picture of metabolic changes resulting from impaired STAT5 signalling by the growth hormone

  7. Independent signaling by Drosophila insulin receptor for axon guidance and growth

    Directory of Open Access Journals (Sweden)

    Caroline Rita Li

    2014-01-01

    Full Text Available The Drosophila insulin receptor (DInR regulates a diverse array of biological processes including growth, axon guidance, and sugar homeostasis. Growth regulation by DInR is mediated by Chico, the Drosophila homolog of vertebrate insulin-receptor-substrate proteins IRS1-4. In contrast, DInR regulation of photoreceptor axon guidance in the developing visual system is mediated by the SH2-SH3 domain adaptor protein Dreadlocks (Dock. In vitro studies by others identified five NPXY motifs, one in the juxtamembrane region and four in the signaling C-terminal tail (C-tail, important for interaction with Chico. Here we used yeast two-hybrid assays to identify regions in the DInR C-tail that interact with Dock. These Dock-binding sites were in separate portions of the C-tail from the previously identified Chico-binding sites. To test whether these sites are required for growth or axon guidance in whole animals, a panel of DInR proteins, in which the putative Chico and Dock interaction sites had been mutated individually or in combination, were tested for their ability to rescue viability, growth, and axon guidance defects of dinr mutant flies. Sites required for viability were identified. Unexpectedly, mutation of both putative Dock binding sites, either individually or in combination, did not lead to defects in photoreceptor axon guidance. Thus, either sites also required for viability are necessary for DInR function in axon guidance and/or there is redundancy built into the DInR/Dock interaction such that Dock is able to interact with multiple regions of DInR. We also found that simultaneous mutation of all 5 NPXY motifs implicated in Chico interaction drastically decreased growth in both male and female adult flies. Mutation of these 5 NPXY motifs did not affect photoreceptor axon guidance, showing that different sites within DInR control growth and axon guidance.

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

    Directory of Open Access Journals (Sweden)

    Birgitte P S Jacky

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

  9. Platelet-Derived Growth Factor-Receptor α Strongly Inhibits Melanoma Growth In Vitro and In Vivo

    Directory of Open Access Journals (Sweden)

    Debora Faraone

    2009-08-01

    Full Text Available Cutaneous melanoma is the most aggressive skin cancer; it is highly metastatic and responds poorly to current therapies. The expression of platelet-derived growth factor receptors (PDGF-Rs is reported to be reduced in metastatic melanoma compared with benign nevi or normal skin; we then hypothesized that PDGF-Rα may control growth of melanoma cells. We show here that melanoma cells overexpressing PDGF-Rα respond to serum with a significantly lower proliferation compared with that of controls. Apoptosis, cell cycle arrest, pRb dephosphorylation, and DNA synthesis inhibition were also observed in cells overexpressing PDGF-Rα. Proliferation was rescued by PDGF-Rα inhibitors, allowing to exclude nonspecific toxic effects and indicating that PDGF-Rα mediates autocrine antiproliferation signals in melanoma cells. Accordingly, PDGF-Rα was found to mediate staurosporine cytotoxicity. A protein array-based analysis of the mitogen-activated protein kinase pathway revealed that melanoma cells overexpressing PDGF-Rα show a strong reduction of c-Jun phosphorylated in serine 63 and of protein phosphatase 2A/Bα and a marked increase of p38γ, mitogen-activated protein kinase kinase 3, and signal regulatory protein α1 protein expression. In a mouse model of primary melanoma growth, infection with the Ad-vector overexpressing PDGF-Rα reached a significant 70% inhibition of primary melanoma growth (P < .001 and a similar inhibition of tumor angiogenesis. All together, these data demonstrate that PDGF-Rα strongly impairs melanoma growth likely through autocrine mechanisms and indicate a novel endogenous mechanism involved in melanoma control.

  10. Involvement of platelet-derived growth factor ligands and receptors in tumorigenesis.

    Science.gov (United States)

    Heldin, C-H; Lennartsson, J; Westermark, B

    2018-01-01

    Platelet-derived growth factor (PDGF) isoforms and their receptors have important roles during embryogenesis, particularly in the development of various mesenchymal cell types in different organs. In the adult, PDGF stimulates wound healing and regulates tissue homeostasis. However, overactivity of PDGF signalling is associated with malignancies and other diseases characterized by excessive cell proliferation, such as fibrotic conditions and atherosclerosis. In certain tumours, genetic or epigenetic alterations of the genes for PDGF ligands and receptors drive tumour cell proliferation and survival. Examples include the rare skin tumour dermatofibrosarcoma protuberance, which is driven by autocrine PDGF stimulation due to translocation of a PDGF gene, and certain gastrointestinal stromal tumours and leukaemias, which are driven by constitute activation of PDGF receptors due to point mutations and formation of fusion proteins of the receptors, respectively. Moreover, PDGF stimulates cells in tumour stroma and promotes angiogenesis as well as the development of cancer-associated fibroblasts, both of which promote tumour progression. Inhibitors of PDGF signalling may thus be of clinical usefulness in the treatment of certain tumours. © 2017 The Association for the Publication of the Journal of Internal Medicine.

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

    Science.gov (United States)

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

    2007-01-01

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

  12. Association of Polymorphisms in Connective Tissue Growth Factor and Epidermal Growth Factor Receptor Genes With Human Longevity.

    Science.gov (United States)

    Donlon, Timothy A; Morris, Brian J; He, Qimei; Chen, Randi; Masaki, Kamal H; Allsopp, Richard C; Willcox, D Craig; Tranah, Gregory J; Parimi, Neeta; Evans, Daniel S; Flachsbart, Friederike; Nebel, Almut; Kim, Duk-Hwan; Park, Joobae; Willcox, Bradley J

    2017-08-01

    Growth pathways play key roles in longevity. The present study tested single-nucleotide polymorphisms (SNPs) in the connective tissue growth factor gene (CTGF) and the epidermal growth factor receptor gene (EGFR) for association with longevity. Comparison of allele and genotype frequencies of 12 CTGF SNPs and 41 EGFR SNPs between 440 American men of Japanese ancestry aged ≥95 years and 374 men of average life span revealed association with longevity at the p cases, consistent with heterozygote advantage in living to extreme old age. No associations of the most significant SNPs were observed in whites or Koreans. In conclusion, the present findings indicate that genetic variation in CTGF and EGFR may contribute to the attainment of extreme old age in Japanese. More research is needed to confirm that genetic variation in CTGF and EGFR contributes to the attainment of extreme old age across human populations. © The Author 2016. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  13. Complex Relationship between Ligand Binding and Dimerization in the Epidermal Growth Factor Receptor

    Directory of Open Access Journals (Sweden)

    Nicholas J. Bessman

    2014-11-01

    Full Text Available The epidermal growth factor receptor (EGFR plays pivotal roles in development and is mutated or overexpressed in several cancers. Despite recent advances, the complex allosteric regulation of EGFR remains incompletely understood. Through efforts to understand why the negative cooperativity observed for intact EGFR is lost in studies of its isolated extracellular region (ECR, we uncovered unexpected relationships between ligand binding and receptor dimerization. The two processes appear to compete. Surprisingly, dimerization does not enhance ligand binding (although ligand binding promotes dimerization. We further show that simply forcing EGFR ECRs into preformed dimers without ligand yields ill-defined, heterogeneous structures. Finally, we demonstrate that extracellular EGFR-activating mutations in glioblastoma enhance ligand-binding affinity without directly promoting EGFR dimerization, suggesting that these oncogenic mutations alter the allosteric linkage between dimerization and ligand binding. Our findings have important implications for understanding how EGFR and its relatives are activated by specific ligands and pathological mutations.

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

    Directory of Open Access Journals (Sweden)

    Jihene Elloumi-Mseddi

    2014-01-01

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

  15. Treatment related changes of the serum epidermal growth factor receptor in advanced colorectal cancer

    DEFF Research Database (Denmark)

    Spindler, K G; Aalund Olsen, Dorte; Brandslund, I

    2009-01-01

    e22096 Background: The epidermal growth factor receptor (EGFR) is an established target for therapy in colorectal cancer. The extracellular domain of the receptor is shed into circulation and detectable by ELISA. We investigated the changes in sEGFR levels during preoperative chemoradiation (CRT......) in rectal cancer patients and third-line treatment with cetuximab and irinotecan (CETIRI) in advanced disease, to elucidate the predictive or prognostic value in these settings. METHODS: We included 126 healthy controls and 118 patients with chemorefractory mCRC treated with cetuximab (initial 400/m(2) mg...... significant differences between the median pre-treatment sEGFR levels in controls, rectal cancer and mCRC (58 ng/ml(56-59 95% C-I), 53 ng/ml(51-55 95% C-I) and 51 ng/ml(49-53 95% C-I), respectively, ptreatment values during CETIRI (p

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

    Science.gov (United States)

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

    2015-01-01

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

  17. [Clinical significance of tumor content of epidermal growth factor receptor in breast cancer].

    Science.gov (United States)

    Mulero, M; Fernández Raigoso, P; Vázquez, J; Lamelas, M L; Corte, D; Allende, M T; Rodríguez, J C; Vizoso, F

    2003-11-01

    To determine the content of epidermal growth factor receptor (EGFR) using a radioligand method in breast cancer and to analyze the relationship between the EGFR levels and the characteristics of patients and tumors. Prognostic significance was also analyzed. EGFR was measured by a single point radioligand assay in 265 invasive breast carcinomas tissues. In addition, estrogen and progesterone receptors (ER and PR) were measured by enzymatic immunoassays. We analyze the relationship of EGFR levels with the different clinico-pathologic parameters. EGFR levels in breast carcinomas varied widely (0.1 to 403) with a median at 4 fmol/mg prot. The significantly higher concentrations of EGFR were detected in patients under 60 years old (p = 0.042), undifferentiated tumors (p = 0.04), and carcinomas with negative ER and PR (p aggresive characteristics of the tumor.

  18. Methylthioadenosine phosphorylase and activated insulin-like growth factor-1 receptor/insulin receptor: potential therapeutic targets in chordoma.

    Science.gov (United States)

    Sommer, Josh; Itani, Doha M; Homlar, Kelly C; Keedy, Vicki L; Halpern, Jennifer L; Holt, Ginger E; Schwartz, Herbert S; Coffin, Cheryl M; Kelley, Michael J; Cates, Justin M M

    2010-04-01

    Currently there is no effective chemotherapy for chordoma. Recent studies report co-expression of insulin-like growth factor-1 receptor (IGF1R) and its cognate ligand in chordoma, but it is unknown whether this receptor tyrosine kinase is activated in these tumours. Additionally, genetic studies have confirmed frequent deletions of chromosome 9p in chordomas, which encompasses the cyclin-dependent kinase inhibitor 2A (CDKN2A) locus. Another gene in this region, methylthioadenosine phosphorylase (MTAP), is an essential enzyme of the purine salvage pathway and has therapeutic relevance because MTAP-deficient cells are particularly sensitive to inhibitors of de novo purine synthesis. We investigated whether these pathways might be potential therapeutic targets for chordoma. Paraffin-embedded tissue samples from 30 chordomas were analysed by immunohistochemistry for expression of the phosphorylated isoforms of IGF1R or the insulin receptor (pIGF1R/pIR) and selected downstream signalling molecules, including BCL2-associated agonist of cell death protein (BAD). Expression of CDKN2A and MTAP proteins was also assessed. Skeletal chondrosarcomas, benign notochordal cell tumours, and fetal notochord were studied for comparison. Phosphorylated IGF1R/IR was detected in 41% of chordomas, together with activated downstream signalling molecules, and pIGF1R/pIR was absent in benign notochordal cell tumours and fetal notochord. Thirty-nine per cent of chordomas were negative for MTAP immunoreactivity. Patients with pIGF1R/pIR-positive tumours showed significantly decreased median disease-free survival in multivariate survival analysis (p = 0.036), whereas phosphorylation of BAD at serine-99 was found to be associated with a favourable prognosis (p = 0.002). Approximately 40% of chordomas demonstrate evidence of activation of the IGF1R/IR signalling pathway or loss of a key enzyme in the purine salvage pathway. Aberrant signalling cascades and disrupted metabolic pathways such as

  19. Genomic organization of the mouse fibroblast growth factor receptor 3 (Fgfr3) gene

    Energy Technology Data Exchange (ETDEWEB)

    Perez-Castro, A.V.; Wilson, J.; Altherr, M.R. [Los Alamos National Lab., NM (United States)

    1995-11-20

    The fibroblast growth factor receptor 3 (Fgfr3) protein is a tyrosine kinase receptor involved in the signal transduction of various fibroblast growth factors. Recent studies suggest its important role in normal development. In humans, mutation in Fgfr3 is responsible for growth disorders such as achondroplasia, hypoachondroplasia, and thanatophoric dysplasia. Here, we report the complete genomic organization of the mouse Fgfr3 gene. The murine gene spans approximately 15 kb and consists of 19 exons and 18 introns. One major and one minor transcription initiation site were identified. Position +1 is located 614 nucleotides upstream from the ATG initiation codon. The translation initiation and termination sites are located in exons 2 and 19, respectively. Five Sp1 sites, two AP2 sites, one Zeste site, and one Krox 24 site were observed in the 5{prime}-flanking region. The Fgfr3 promoter appears to be contained within a CpG island and, as is common in genes having multiple Sp1-binding sites, lacks a TATA box. 35 refs., 3 figs., 1 tab.

  20. The nuclear receptor DHR3 modulates dS6 kinase-dependent growth in Drosophila.

    Directory of Open Access Journals (Sweden)

    Jacques Montagne

    2010-05-01

    Full Text Available S6 kinases (S6Ks act to integrate nutrient and insulin signaling pathways and, as such, function as positive effectors in cell growth and organismal development. However, they also have been shown to play a key role in limiting insulin signaling and in mediating the autophagic response. To identify novel regulators of S6K signaling, we have used a Drosophila-based, sensitized, gain-of-function genetic screen. Unexpectedly, one of the strongest enhancers to emerge from this screen was the nuclear receptor (NR, Drosophila hormone receptor 3 (DHR3, a critical constituent in the coordination of Drosophila metamorphosis. Here we demonstrate that DHR3, through dS6K, also acts to regulate cell-autonomous growth. Moreover, we show that the ligand-binding domain (LBD of DHR3 is essential for mediating this response. Consistent with these findings, we have identified an endogenous DHR3 isoform that lacks the DBD. These results provide the first molecular link between the dS6K pathway, critical in controlling nutrient-dependent growth, and that of DHR3, a major mediator of ecdysone signaling, which, acting together, coordinate metamorphosis.

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

    Directory of Open Access Journals (Sweden)

    Donahue Renee N

    2009-10-01

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

  2. Acetylcholine elongates neuronal growth cone filopodia via activation of nicotinic acetylcholine receptors.

    Science.gov (United States)

    Zhong, Lei Ray; Estes, Stephen; Artinian, Liana; Rehder, Vincent

    2013-07-01

    In addition to acting as a classical neurotransmitter in synaptic transmission, acetylcholine (ACh) has been shown to play a role in axonal growth and growth cone guidance. What is not well understood is how ACh acts on growth cones to affect growth cone filopodia, structures known to be important for neuronal pathfinding. We addressed this question using an identified neuron (B5) from the buccal ganglion of the pond snail Helisoma trivolvis in cell culture. ACh treatment caused pronounced filopodial elongation within minutes, an effect that required calcium influx and resulted in the elevation of the intracellular calcium concentration ([Ca]i ). Whole-cell patch clamp recordings showed that ACh caused a reduction in input resistance, a depolarization of the membrane potential, and an increase in firing frequency in B5 neurons. These effects were mediated via the activation of nicotinic acetylcholine receptors (nAChRs), as the nAChR agonist dimethylphenylpiperazinium (DMPP) mimicked the effects of ACh on filopodial elongation, [Ca]i elevation, and changes in electrical activity. Moreover, the nAChR antagonist tubucurarine blocked all DMPP-induced effects. Lastly, ACh acted locally at the growth cone, because growth cones that were physically isolated from their parent neuron responded to ACh by filopodial elongation with a similar time course as growth cones that remained connected to their parent neuron. Our data revealed a critical role for ACh as a modulator of growth cone filopodial dynamics. ACh signaling was mediated via nAChRs and resulted in Ca influx, which, in turn, caused filopodial elongation. Copyright © 2013 Wiley Periodicals, Inc.

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

    Directory of Open Access Journals (Sweden)

    Campbell Craig I

    2011-11-01

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

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

    Science.gov (United States)

    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.

  5. Role of epidermal growth factor receptor activation in regulating mucin synthesis

    Directory of Open Access Journals (Sweden)

    Nadel Jay A

    2001-02-01

    Full Text Available Abstract Healthy individuals have few goblet cells in their airways, but in patients with hypersecretory diseases goblet-cell upregulation results in mucus hypersecretion, airway plugging, and death. Multiple stimuli produce hypersecretion via epidermal growth factor receptor (EGFR expression and activation, causing goblet-cell metaplasia from Clara cells by a process of cell differentiation. These cells are also believed to be the cells of origin of non-small-cell lung cancer, but this occurs via cell multiplication. The mechanisms that determine which pathway is chosen are critical but largely unknown. Although no effective therapy exists for hypersecretion at present, the EGFR cascade suggests methods for effective therapeutic intervention.

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

    DEFF Research Database (Denmark)

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

    1992-01-01

    for cells expressing kinase-negative receptor (A721). Moreover, tyrosine kinase activity of the Dc-123F receptor toward phospholipase C-gamma 1, compared to wild-type receptor, was reduced by 90%. Taken together, these results show that EGF receptor lacking five autophosphorylation sites functions similar...

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

    Directory of Open Access Journals (Sweden)

    Mahdi Behdani

    2012-01-01

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

  8. Growth and gene expression are predominantly controlled by distinct regions of the human IL-4 receptor.

    Science.gov (United States)

    Ryan, J J; McReynolds, L J; Keegan, A; Wang, L H; Garfein, E; Rothman, P; Nelms, K; Paul, W E

    1996-02-01

    IL-4 causes hematopoietic cells to proliferate and express a series of genes, including CD23. We examined whether IL-4-mediated growth, as measured by 4PS phosphorylation, and gene induction were similarly controlled. Studies of M12.4.1 cells expressing human IL-4R truncation mutants indicated that the region between amino acids 557-657 is necessary for full gene expression, which correlated with Stat6 DNA binding activity. This region was not required for 4PS phosphorylation. Tyrosine-to-phenylalanine mutations in the interval between amino acids 557-657 revealed that as long as one tyrosine remained unmutated, CD23 was fully induced. When all three tyrosines were mutated, the receptor was unable to induce CD23. The results indicate that growth regulation and gene expression are principally controlled by distinct regions of IL-4R.

  9. The Epidermal Growth Factor Receptor Is a Regulator of Epidermal Complement Component Expression and Complement Activation

    DEFF Research Database (Denmark)

    Abu-Humaidan, Anas H A; Ananthoju, Nageshwar; Mohanty, Tirthankar

    2014-01-01

    The complement system is activated in response to tissue injury. During wound healing, complement activation seems beneficial in acute wounds but may be detrimental in chronic wounds. We found that the epidermal expression of many complement components was only increased to a minor extent in skin...... wounds in vivo and in cultured keratinocytes after exposure to supernatant from stimulated mononuclear cells. In contrast, the epidermal expression of complement components was downregulated in ex vivo injured skin lacking the stimulation from infiltrating inflammatory cells but with intact injury......-induced epidermal growth factor receptor (EGFR)-mediated growth factor response. In cultured primary keratinocytes, stimulation with the potent EGFR ligand, TGF-α, yielded a significant downregulation of complement component expression. Indeed, EGFR inhibition significantly enhanced the induction of complement...

  10. Growth hormone-specific induction of the nuclear localization of porcine growth hormone receptor in porcine hepatocytes.

    Science.gov (United States)

    Lan, H N; Hong, P; Li, R N; Shan, A S; Zheng, X

    2017-10-01

    The phenomenon of nuclear translocation of growth hormone receptor (GHR) in human, rat, and fish has been reported. To date, this phenomenon has not been described in a domestic animal (such as pig). In addition, the molecular mechanisms of GHR nuclear translocation have not been thoroughly elucidated. To this end, porcine hepatocytes were isolated and used as a cell model. We observed that porcine growth hormone (pGH) can induce porcine GHR's nuclear localization in porcine hepatocytes. Subsequently, the dynamics of pGH-induced pGHR's nuclear localization were analyzed and demonstrated that pGHR's nuclear localization occurs in a time-dependent manner. Next, we explored the mechanism of pGHR nuclear localization using different pGHR ligands, and we demonstrated that pGHR's nuclear translocation is GH(s)-dependent. We also observed that pGHR translocates into cell nuclei in a pGH dimerization-dependent fashion, whereas further experiments indicated that IMPα/β is involved in the nuclear translocation of the pGH-pGHR dimer. The pGH-pGHR dimer may form a pGH-GHR-JAK2 multiple complex in cell nuclei, which would suggest that similar to its function in the cell membrane, the nuclear-localized pGH-pGHR dimer might still have the ability to signal. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. Mutation of the SHP-2 binding site in growth hormone (GH) receptor prolongs GH-promoted tyrosyl phosphorylation of GH receptor, JAK2, and STAT5B

    DEFF Research Database (Denmark)

    Stofega, M R; Herrington, J; Billestrup, Nils

    2000-01-01

    Binding of GH to GH receptor (GHR) rapidly and transiently activates multiple signal transduction pathways that contribute to the growth-promoting and metabolic effects of GH. While the events that initiate GH signal transduction, such as activation of the Janus tyrosine kinase JAK2, are beginnin...

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

    NARCIS (Netherlands)

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

    2011-01-01

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

  13. Function of insulin-like growth factor 1 receptor in cancer resistance to chemotherapy.

    Science.gov (United States)

    Yuan, Jingsheng; Yin, Zhijie; Tao, Kaixiong; Wang, Guobing; Gao, Jinbo

    2018-01-01

    Drug resistance is a primary cause of chemotherapeutic failure; however, how this resistance develops is complex. A comprehensive understanding of chemotherapeutic resistance mechanisms may aid in identifying more effective drugs and improve the survival rates of patients with cancer. Insulin-like growth factor 1 receptor (IGF1R), a member of the insulin receptor family, has been extensively assessed for biological activity, and its putative contribution to tumor cell development and progression. Furthermore, researchers have attended to drugs that target IGF1R since IGF1R functions as a membrane receptor. However, how IGF1R participates in chemotherapeutic resistance remains unclear. Therefore, the present study described the IGF1R gene and its associated signaling pathways, and offered details of IGF1R-induced tumor chemoresistance associated with promoting cell proliferation, inhibition of apoptosis, regulation of ATP-binding cassette transporter proteins and interactions with the extracellular matrix. The present study offered additional explanations for tumor chemotherapy resistance and provided a theoretical basis of IGF1R and its downstream pathways for future possible chemotherapy treatment options.

  14. The Role of Vascular Endothelial Growth Factor Receptor-1 Signaling in the Recovery from Ischemia.

    Science.gov (United States)

    Amano, Hideki; Kato, Shintaro; Ito, Yoshiya; Eshima, Koji; Ogawa, Fumihiro; Takahashi, Ryo; Sekiguchi, Kazuki; Tamaki, Hideaki; Sakagami, Hiroyuki; Shibuya, Masabumi; Majima, Masataka

    2015-01-01

    Vascular endothelial growth factor (VEGF) is one of the most potent angiogenesis stimulators. VEGF binds to VEGF receptor 1 (VEGFR1), inducing angiogenesis through the receptor's tyrosine kinase domain (TK), but the mechanism is not well understood. We investigated the role of VEGFR1 tyrosine kinase signaling in angiogenesis using the ischemic hind limb model. Relative to control mice, blood flow recovery was significantly impaired in mice treated with VEGFA-neutralizing antibody. VEGFR1 tyrosine kinase knockout mice (TK-/-) had delayed blood flow recovery from ischemia and impaired angiogenesis, and this phenotype was unaffected by treatment with a VEGFR2 inhibitor. Compared to wild type mice (WT), TK-/- mice had no change in the plasma level of VEGF, but the plasma levels of stromal-derived cell factor 1 (SDF-1) and stem cell factor, as well as the bone marrow (BM) level of pro-matrix metalloproteinase-9 (pro-MMP-9), were significantly reduced. The recruitment of cells expressing VEGFR1 and C-X-C chemokine receptor type 4 (CXCR4) into peripheral blood and ischemic muscles was also suppressed. Furthermore, WT transplanted with TK-/- BM significantly impaired blood flow recovery more than WT transplanted with WT BM. These results suggest that VEGFR1-TK signaling facilitates angiogenesis by recruiting CXCR4+VEGFR1+ cells from BM.

  15. Thrombospondin-1 modulates vascular endothelial growth factor activity at the receptor level.

    Science.gov (United States)

    Zhang, Xuefeng; Kazerounian, Shideh; Duquette, Mark; Perruzzi, Carole; Nagy, Janice A; Dvorak, Harold F; Parangi, Sareh; Lawler, Jack

    2009-10-01

    Vascular endothelial growth factor (VEGF) is a well-established stimulator of vascular permeability and angiogenesis, whereas thrombospondin-1 (TSP-1) is a potent angiogenic inhibitor. In this study, we have found that the TSP-1 receptors CD36 and beta1 integrin associate with the VEGF receptor 2 (VEGFR2). The coclustering of receptors that regulate angiogenesis may provide the endothelial cell with a platform for integration of positive and negative signals in the plane of the membrane. Thus, this complex may represent a molecular switch that regulates angiogenesis and determines endothelial cell behavior. In this context, physiological levels of TSP-1 appear to support VEGFR2 function on both the cellular and tissue level, because phosphorylation of VEGFR2 and vascular permeability in response to VEGF are decreased in TSP-1-null mice and isolated endothelial cells. A therapeutic agent based on the antiangiogenic domain of TSP-1, designated 3TSR (for three TSP-1 type 1 repeats), has significant antiangiogenic and antitumor efficacy. Systemic treatment of wild-type mice with 3TSR significantly decreased VEGF-induced permeability. Consistent with this result, VEGF-stimulated phosphorylation of VEGFR2 was also significantly decreased in lung extracts from 3TSR-treated mice. Moreover, 3TSR significantly decreased VEGF-stimulated VEGFR2 phosphorylation in human dermal microvascular endothelial cells in culture. Taken together, the results indicate that TSP-1 and 3TSR modulate the function of VEGFR2.

  16. Vascular endothelial growth factor receptor-1 contributes to resistance to anti-epidermal growth factor receptor drugs in human cancer cells.

    Science.gov (United States)

    Bianco, Roberto; Rosa, Roberta; Damiano, Vincenzo; Daniele, Gennaro; Gelardi, Teresa; Garofalo, Sonia; Tarallo, Valeria; De Falco, Sandro; Melisi, Davide; Benelli, Roberto; Albini, Adriana; Ryan, Anderson; Ciardiello, Fortunato; Tortora, Giampaolo

    2008-08-15

    The resistance to selective EGFR inhibitors involves the activation of alternative signaling pathways, and Akt activation and VEGF induction have been described in EGFR inhibitor-resistant tumors. Combined inhibition of EGFR and other signaling proteins has become a successful therapeutic approach, stimulating the search for further determinants of resistance as basis for novel therapeutic strategies. We established human cancer cell lines with various degrees of EGFR expression and sensitivity to EGFR inhibitors and analyzed signal transducers under the control of EGFR-dependent and EGFR-independent pathways. Multitargeted inhibitor vandetanib (ZD6474) inhibited the growth and the phosphorylation of Akt and its effector p70S6 kinase in both wild-type and EGFR inhibitor-resistant human colon, prostate, and breast cancer cells. We found that the resistant cell lines exhibit, as common feature, VEGFR-1/Flt-1 overexpression, increased secretion of VEGF and placental growth factor, and augmented migration capabilities and that vandetanib is able to antagonize them. Accordingly, a new kinase assay revealed that in addition to VEGF receptor (VEGFR)-2, RET, and EGFR, vandetanib efficiently inhibits also VEGFR-1. The contribution of VEGFR-1 to the resistant phenotype was further supported by the demonstration that VEGFR-1 silencing in resistant cells restored sensitivity to anti-EGFR drugs and impaired migration capabilities, whereas exogenous VEGFR-1 overexpression in wild-type cells conferred resistance to these agents. This study shows that VEGFR-1 contributes to anti-EGFR drug resistance in different human cancer cells. Moreover, vandetanib inhibits VEGFR-1 activation, cell proliferation, and migration, suggesting its potential utility in patients resistant to EGFR inhibitors.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-08-15

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

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

    Science.gov (United States)

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

    2016-05-01

    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. We investigated the hypothesis that the potency of parabens can be increased with HER ligands, such as heregulin (HRG). 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. 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. 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. Pan S, Yuan C, Tagmount A, Rudel RA, Ackerman JM, Yaswen P, Vulpe CD, Leitman DC. 2016. Parabens and human epidermal

  19. Expression of somatostatin, dopamine, progesterone and growth hormone receptor mRNA in canine cortisol-secreting adrenocortical tumours.

    Science.gov (United States)

    Kool, Miriam M J; Galac, Sara; van der Helm, Noortje; Spandauw, Catharina G; Kooistra, Hans S; Mol, Jan A

    2015-10-01

    Cortisol-secreting adrenocortical tumours (AT) in dogs are characterised by uncontrolled growth and excessive cortisol secretion. Dysregulated hormone receptor expression might be involved in tumour growth and hypersecretion of cortisol. The relative mRNA expression of growth hormone receptor, progesterone receptor, somatostatin receptors (SSTR1-3) and dopamine receptors (DRD1-2 and DRD5) was evaluated in 36 canine ATs and 15 adrenal glands obtained from healthy dogs. Compared with normal adrenal tissue, DRD2 mRNA expression was relatively lower in carcinomas, while SSTR1 mRNA expression was lower in both adenomas and carcinomas. Both of these features might contribute to loss of inhibition of tumour growth and upregulation of cortisol secretion. In canine ATs that had recurred within 30 months of surgical adrenalectomy, a marked increase in expression of DRD1 mRNA was observed. Targeting of specific hormone receptors, expressed by ATs, might be exploited for therapy. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Hormones, receptors, and growth in hyperplastic enlarged lobular units: early potential precursors of breast cancer.

    Science.gov (United States)

    Lee, Sangjun; Mohsin, Syed K; Mao, Sufeng; Hilsenbeck, Susan G; Medina, Dan; Allred, D Craig

    2006-01-01

    The hyperplastic enlarged lobular unit (HELU) is a common alteration in adult female human breast and is the earliest histologically identifiable lesion with premalignant potential. Growth and differentiation in normal epithelium are regulated by estrogen and progesterone, whose effects are mediated through estrogen receptor (ER)-alpha and progesterone receptor (PR). We assessed correlations between growth (proliferation and apoptosis), endogenous hormone levels (using age as a surrogate for menopausal/estrogen status), and ER-alpha/PR expression in HELUs versus adjacent normal terminal duct lobular units (TDLUs) to gain insight into potentially premalignant hyperplasia. Proliferation (Ki67 antigen), ER-alpha, and PR were assessed by immunohistochemistry, apoptosis using the TUNEL (terminal transferase-mediated dUTP nick end-labeling) assay, and nuclear colocalization of ER-alpha and Ki67 by dual-labeled immunofluorescence in HELUs and adjacent TDLUs (n = 100-584, depending on the factor) from 324 breasts. All factors were quantified under direct microscopic visualization. ER-alpha/PR expression was semiquantified by estimating the proportion of positive cells (0 = none, 1 = or 2/3). Ki67, TUNEL, and colocalization of ER-alpha and Ki67 were scored by absolute counting (%positive). ER-alpha and PR expression were significantly elevated in HELUs versus adjacent TLDUs (average score: 4.5 versus 3.1 and 3.5 versus 2.1; P apoptosis was significantly lower in HELUs versus TDLUs (average 0.61% versus 0.22%; P breast cancer.

  1. Fibroblast growth factor receptor-2 mutation analysis in human prostate cancer.

    Science.gov (United States)

    Mehta, P; Robson, C N; Neal, D E; Leung, H Y

    2000-10-01

    To assess whether mutations in the hot-spots of the fibroblast growth factor (FGF) receptor-2 gene (FGFR2, exons encoding the IIIa, IIIb, IIIc and transmembrane domain, TMD) are associated with the development of prostate cancer, as the IIIb variant is the specific receptor for FGF7/KGF, an androgen-inducible paracrine factor regulating prostatic growth. Materials and methods Single-strand conformational polymorphism-polymerase chain reaction (SSCP-PCR) and cycle-sequencing analysis were used to screen FGFR2 mutations in 30 patients with prostate cancer; corresponding blood samples were analysed from 11 of the patients. The human prostate cell lines, LNCaP, PC3, DU145, PNT1A and PNT1B were also examined. In addition, 10 foci of invasive cancer from three patients who underwent radical prostatectomy were also assessed. Positive controls containing FGFR2 mutations (Crouzon disease and Pfieffer syndrome) were confirmed by SSCP-PCR and sequencing. Analysis of all prostate tumour samples and prostate-derived cell lines revealed no polymorphisms or mutations in the IIIa, IIIb, IIIc and TMD regions of FGFR2. FGFR2 mutations in the-FGF binding domain and the TMD are not frequent events in human prostate cancer.

  2. Maternal endotoxin-induced fetal growth restriction in rats: Fetal responses in toll-like receptor

    Directory of Open Access Journals (Sweden)

    Banun Kusumawardani

    2012-09-01

    Full Text Available Background: Porphyromonas gingivalis as a major etiology of periodontal disease can produce virulence factor, lipopolysaccharide/LPS, which is expected to play a role in the intrauterine fetal growth. Trophoblast at the maternal-fetal interface actively participates in response to infection through the expression of a family of natural immune receptors, toll-like receptor (TLR. Purpose: the aims of study were to identify endotoxin concentration in maternal blood serum of Porphyromonas gingivalis-infected pregnant rats, to characterize the TLR-4 expression in trophoblast cells, and to determine its effect on fetal growth. Methods: Female rats were infected with live-Porphyromonas gingivalis at concentration of 2 x 109 cells/ml into subgingival sulcus area of the maxillary first molar before and/or during pregnancy. They were sacrified on 14th and 20th gestational day. Fetuses were evaluated for weight and length. Endotoxin was detected by limulus amebocyte lysate assay in the maternal blood serum. The TLR-4 expression in trophoblast cells was detected by immunohistochemistry. Physiological epidermal growth factor concentrations activate high affinity receptors to elicit calcium oscillations.

    Directory of Open Access Journals (Sweden)

    Béatrice Marquèze-Pouey

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

  3. Distinct roles for classical nuclear import receptors in the growth of multinucleated muscle cells.

    Science.gov (United States)

    Hall, Monica N; Griffin, Christine A; Simionescu, Adriana; Corbett, Anita H; Pavlath, Grace K

    2011-09-01

    Proper muscle function is dependent on spatial and temporal control of gene expression in myofibers. Myofibers are multinucleated cells that are formed, repaired and maintained by the process of myogenesis in which progenitor myoblasts proliferate, differentiate and fuse. Gene expression is dependent upon proteins that require facilitated nuclear import, however little is known about the regulation of nucleocytoplasmic transport during the formation of myofibers. We analyzed the role of karyopherin alpha (KPNA), a key classical nuclear import receptor, during myogenesis. We established that five karyopherin alpha paralogs are expressed by primary mouse myoblasts in vitro and that their steady-state levels increase in multinucleated myotubes, suggesting a global increase in demand for classical nuclear import during myogenesis. We used siRNA-mediated knockdown to identify paralog-specific roles for KPNA1 and KPNA2 during myogenesis. KPNA1 knockdown increased myoblast proliferation, whereas KPNA2 knockdown decreased proliferation. In contrast, no proliferation defect was observed with KPNA4 knockdown. Only knockdown of KPNA2 decreased myotube growth. These results identify distinct pathways involved in myoblast proliferation and myotube growth that rely on specific nuclear import receptors suggesting that regulation of classical nuclear import pathways likely plays a critical role in controlling gene expression in skeletal muscle. Copyright © 2011 Elsevier Inc. All rights reserved.

  4. Distinct roles for classical nuclear import receptors in the growth of multinucleated muscle cells☆

    Science.gov (United States)

    Hall, Monica N.; Griffin, Christine A.; Simionescu, Adriana; Corbett, Anita H.; Pavlath, Grace K.

    2011-01-01

    Proper muscle function is dependent on spatial and temporal control of gene expression in myofibers. Myofibers are multinucleated cells that are formed, repaired and maintained by the process of myogenesis in which progenitor myoblasts proliferate, differentiate and fuse. Gene expression is dependent upon proteins that require facilitated nuclear import, however little is known about the regulation of nucleocytoplasmic transport during the formation of myofibers. We analyzed the role of karyopherin alpha (KPNA), a key classical nuclear import receptor, during myogenesis. We established that five karyopherin alpha paralogs are expressed by primary mouse myoblasts in vitro and that their steady-state levels increase in multinucleated myotubes, suggesting a global increase in demand for classical nuclear import during myogenesis. We used siRNA-mediated knockdown to identify paralog-specific roles for KPNA1 and KPNA2 during myogenesis. KPNA1 knockdown increased myoblast proliferation, whereas KPNA2 knockdown decreased proliferation. In contrast, no proliferation defect was observed with KPNA4 knockdown. Only knockdown of KPNA2 decreased myotube growth. These results identify distinct pathways involved in myoblast proliferation and myotube growth that rely on specific nuclear import receptors suggesting that regulation of classical nuclear import pathways likely plays a critical role in controlling gene expression in skeletal muscle. PMID:21741962

  5. Suppression of estrogen receptor transcriptional activity by connective tissue growth factor.

    Directory of Open Access Journals (Sweden)

    Long Cheng

    Full Text Available Secreted growth factors have been shown to stimulate the transcriptional activity of estrogen receptors (ER that are responsible for many biological processes. However, whether these growth factors physically interact with ER remains unclear. Here, we show for the first time that connective tissue growth factor (CTGF physically and functionally associates with ER. CTGF interacted with ER both in vitro and in vivo. CTGF interacted with ER DNA-binding domain. ER interaction region in CTGF was mapped to the thrombospondin type I repeat, a cell attachment motif. Overexpression of CTGF inhibited ER transcriptional activity as well as the expression of estrogen-responsive genes, including pS2 and cathepsin D. Reduction of endogenous CTGF with CTGF small interfering RNA enhanced ER transcriptional activity. The interaction between CTGF and ER is required for the repression of estrogen-responsive transcription by CTGF. Moreover, CTGF reduced ER protein expression, whereas the CTGF mutant that did not repress ER transcriptional activity also did not alter ER protein levels. The results suggested the transcriptional regulation of estrogen signaling through interaction between CTGF and ER, and thus may provide a novel mechanism by which cross-talk between secreted growth factor and ER signaling pathways occurs.

  6. Brain IGF-1 receptors control mammalian growth and lifespan through a neuroendocrine mechanism.

    Directory of Open Access Journals (Sweden)

    Laurent Kappeler

    2008-10-01

    Full Text Available Mutations that decrease insulin-like growth factor (IGF and growth hormone signaling limit body size and prolong lifespan in mice. In vertebrates, these somatotropic hormones are controlled by the neuroendocrine brain. Hormone-like regulations discovered in nematodes and flies suggest that IGF signals in the nervous system can determine lifespan, but it is unknown whether this applies to higher organisms. Using conditional mutagenesis in the mouse, we show that brain IGF receptors (IGF-1R efficiently regulate somatotropic development. Partial inactivation of IGF-1R in the embryonic brain selectively inhibited GH and IGF-I pathways after birth. This caused growth retardation, smaller adult size, and metabolic alterations, and led to delayed mortality and longer mean lifespan. Thus, early changes in neuroendocrine development can durably modify the life trajectory in mammals. The underlying mechanism appears to be an adaptive plasticity of somatotropic functions allowing individuals to decelerate growth and preserve resources, and thereby improve fitness in challenging environments. Our results also suggest that tonic somatotropic signaling entails the risk of shortened lifespan.

  7. Reciprocal Regulation of the TOR Kinase and ABA Receptor Balances Plant Growth and Stress Response.

    Science.gov (United States)

    Wang, Pengcheng; Zhao, Yang; Li, Zhongpeng; Hsu, Chuan-Chih; Liu, Xue; Fu, Liwen; Hou, Yueh-Ju; Du, Yanyan; Xie, Shaojun; Zhang, Chunguang; Gao, Jinghui; Cao, Minjie; Huang, Xiaosan; Zhu, Yingfang; Tang, Kai; Wang, Xingang; Tao, W Andy; Xiong, Yan; Zhu, Jian-Kang

    2018-01-04

    As sessile organisms, plants must adapt to variations in the environment. Environmental stress triggers various responses, including growth inhibition, mediated by the plant hormone abscisic acid (ABA). The mechanisms that integrate stress responses with growth are poorly understood. Here, we discovered that the Target of Rapamycin (TOR) kinase phosphorylates PYL ABA receptors at a conserved serine residue to prevent activation of the stress response in unstressed plants. This phosphorylation disrupts PYL association with ABA and with PP2C phosphatase effectors, leading to inactivation of SnRK2 kinases. Under stress, ABA-activated SnRK2s phosphorylate Raptor, a component of the TOR complex, triggering TOR complex dissociation and inhibition. Thus, TOR signaling represses ABA signaling and stress responses in unstressed conditions, whereas ABA signaling represses TOR signaling and growth during times of stress. Plants utilize this conserved phospho-regulatory feedback mechanism to optimize the balance of growth and stress responses. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Canine fibroblast growth factor receptor 3 sequence is conserved across dogs of divergent skeletal size

    Directory of Open Access Journals (Sweden)

    Grossman Deborah I

    2008-10-01

    Full Text Available Abstract Background Fibroblast growth factor receptor 3 (FGFR3 is expressed in the growth plate of endochondral bones and serves as a negative regulator of linear bone elongation. Activating mutations severely limit bone growth, resulting in dwarfism, while inactivating mutations significantly enhance bone elongation and overall skeletal size. Domesticated dogs exhibit the greatest skeletal size diversity of any species and, given the regulatory role of FGFR3 on growth plate proliferation, we asked whether sequence differences in FGFR3 could account for some of the size differences. Methods All exons, the promoter region, and 60 bp of the 3' flanking region of the canine FGFR3 gene were sequenced for nine different dog breeds representing a spectrum of skeletal size. The resultant sequences were compared to the reference Boxer genome sequence. Results There was no variation in sequence for any FGFR3 exons, promoter region, or 3' flanking sequence across all breeds evaluated. Conclusion The results suggest that, regardless of domestication selection pressure to develop breeds having extreme differences in skeletal size, the FGFR3 gene is conserved. This implies a critical role for this gene in normal skeletal integrity and indicates that other genes account for size variability in dogs.

  9. Targeting receptor for advanced glycation end products (RAGE) expression induces apoptosis and inhibits prostate tumor growth

    International Nuclear Information System (INIS)

    Elangovan, Indira; Thirugnanam, Sivasakthivel; Chen, Aoshuang; Zheng, Guoxing; Bosland, Maarten C.; Kajdacsy-Balla, André; Gnanasekar, Munirathinam

    2012-01-01

    Highlights: ► Targeting RAGE by RNAi induces apoptosis in prostate cancer cells. ► Silencing RAGE expression abrogates rHMGB1 mediated cell proliferation. ► Down regulation of RAGE by RNAi inhibits PSA secretion of prostate cancer cells. ► Knock down of RAGE abrogates prostate tumor growth in vivo. ► Disruption of RAGE expression in prostate tumor activates death receptors. -- Abstract: Expression of receptor for advanced glycation end products (RAGE) plays a key role in the progression of prostate cancer. However, the therapeutic potential of targeting RAGE expression in prostate cancer is not yet evaluated. Therefore in this study, we have investigated the effects of silencing the expression of RAGE by RNAi approach both in vitro and in vivo. The results of this study showed that down regulation of RAGE expression by RNAi inhibited the cell proliferation of androgen-dependent (LNCaP) and androgen-independent (DU-145) prostate cancer cells. Furthermore, targeting RAGE expression resulted in apoptotic elimination of these prostate cancer cells by activation of caspase-8 and caspase-3 death signaling. Of note, the levels of prostate specific antigen (PSA) were also reduced in LNCaP cells transfected with RAGE RNAi constructs. Importantly, the RAGE RNAi constructs when administered in nude mice bearing prostate tumors, inhibited the tumor growth by targeting the expression of RAGE, and its physiological ligand, HMGB1 and by up regulating death receptors DR4 and DR5 expression. Collectively, the results of this study for the first time show that targeting RAGE by RNAi may be a promising alternative therapeutic strategy for treating prostate cancer.

  10. Targeting the epidermal growth factor receptor in radiotherapy: radiobiological mechanisms, preclinical and clinical results

    International Nuclear Information System (INIS)

    Baumann, Michael; Krause, Mechthild

    2004-01-01

    Background and purpose: Inhibition of the epidermal growth factor receptor (EGFR) is a fastly developing field in preclinical and clinical cancer research. This review presents the current status of knowledge and discusses radiobiological mechanisms which may underly the efficacy of EGFR inhibitors combined with irradiation. Materials and methods: Preclinical and clinical results on combined targeting of the EGFR and irradiation from the literature and from this laboratory are reviewed. Focus is given to the radiobiological rationale of this approach and to endpoints of experimental radiotherapy. Results: Overexpression of the EGFR is associated with decreased local tumour control after radiotherapy, especially when the overall treatment time is long. Inhibition of the EGFR either alone or in combination with irradiation decreases the growth rate of tumours expressing this receptor. Preclinical data provide proof-of-principle that local tumour control may be improved by combining irradiation with C225 mAb. In a randomised phase III clinical trial, simultaneous irradiation and treatment with the EGFR antibody Cetuximab (Erbitux[reg]; C225) in head and neck cancer patients resulted in significantly improved locoregional tumour control and survival compared to curative irradiation alone. Acute skin reactions increased in the experimental arm. The underlying mechanisms of enhanced radiation effects of combined EGFR inhibition with irradiation and of the partly conflicting results in different studies are poorly understood. There is increasing evidence, that important intertumoral heterogeneity in the response to EGFR inhibition alone and combined with irradiation exists, which appears to be at least partly dependent on specific mutations of the receptor as well as of molecules that are involved in the intracellular signal transduction pathway. Conclusions and outlook: Further investigations at all levels of the translational research chain exploring the mechanisms of

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

    DEFF Research Database (Denmark)

    Bonnesen, Barbara; Pappot, Helle; Holmstav, Julie

    2009-01-01

    elements in neoplastic cells and their microenvironment have recently been and are continuously developed including drugs inhibiting the angiogenic system. Angiogenic factor vascular endothelial growth factor (VEGF) and its receptor vascular endothelial growth factor receptor 2 (VEGFR2) seem to play key......BACKGROUND: The majority of patients with non-small cell lung cancer (NSCLC) are diagnosed with advanced inoperable disease. While treatment with conventional chemotherapy has improved during the last decade the 5 years survival is still modest. Novel drugs, which selectively target aberrant...

  12. C-terminal truncated forms of Met, the hepatocyte growth factor receptor.

    Science.gov (United States)

    Prat, M; Crepaldi, T; Gandino, L; Giordano, S; Longati, P; Comoglio, P

    1991-12-01

    The MET proto-oncogene encodes a transmembrane tyrosine kinase of 190 kDa (p190MET), which has recently been identified as the receptor for hepatocyte growth factor/scatter factor. p190MET is a heterodimer composed of two disulfide-linked chains of 50 kDa (p50 alpha) and 145 kDa (p145 beta). We have produced four different monoclonal antibodies that are specific for the extracellular domain of the Met receptor. These antibodies immunoprecipitate with p190MET two additional Met proteins of 140 and 130 kDa. The first protein (p140MET) is membrane bound and is composed of an alpha chain (p50 alpha) and an 85-kDa C-terminal truncated beta chain (p85 beta). The second protein (p130MET) is released in the culture supernatant and consists of an alpha chain (p50 alpha) and a 75-kDa C-terminal truncated beta chain (p75 beta). Both truncated forms lack the tyrosine kinase domain. p140MET and p130MET are consistently detected in vivo, together with p190MET, in different cell lines or their culture supernatants. p140MET is preferentially localized at the cell surface, where it is present in roughly half the amount of p190MET. The two C-terminal truncated forms of the Met receptor are also found in stable transfectants expressing the full-length MET cDNA, thus showing that they originate from posttranslational proteolysis. This process is regulated by protein kinase C activation. Together, these data suggest that the production of the C-terminal truncated Met forms may have a physiological role in modulating the Met receptor function.

  13. Enhancement by histamine of vascular endothelial growth factor production in granulation tissue via H2 receptors

    Science.gov (United States)

    Ghosh, Ajoy Kumar; Hirasawa, Noriyasu; Ohuchi, Kazuo

    2001-01-01

    Roles of histamine in the production of vascular endothelial growth factor (VEGF) in the carrageenin-induced granulation tissue in rats were analysed in vitro and in vivo.Incubation of the minced granulation tissue in the presence of histamine (1 and 10 μM) increased the content of VEGF protein in the conditioned medium in a time- and concentration-dependent manner. The levels of VEGF mRNA in the minced granulation tissue were also increased by histamine in a concentration-dependent manner.The increase in the content of VEGF protein in the conditioned medium by histamine (10 μM) was suppressed by the H2 receptor antagonist cimetidine (IC50 0.37 μM), but not by the H1 receptor antagonist pyrilamine maleate, the H3 receptor antagonist thioperamide or the cyclo-oxygenase inhibitor indomethacin.The histamine-induced increase in the content of VEGF protein in the conditioned medium was inhibited by the cyclic AMP antagonist Rp-cAMP (IC50 6.8 μM), and the protein kinase A inhibitor H-89 (IC50 12.5 μM), but not by the protein kinase C inhibitors Ro 31-8425 and calphostin C or the tyrosine kinase inhibitor genistein.Simultaneous injection of cimetidine (400 μg) and indomethacin (100 μg) into the air pouch of rats additively reduced the carrageenin-induced increase in VEGF protein levels and angiogenesis in the granulation tissue as assessed by using carmine dye.These findings indicate that histamine has an activity to induce VEGF production in the granulation tissue via the H2 receptor-cyclic AMP-protein kinase A pathway and augments angiogenesis in the granulation tissue. PMID:11724747

  14. A study to correlate histopathology, biochemical marker and immunohistochemical expression of sex-steroid receptors in prostatic growth.

    Science.gov (United States)

    Naskar, Sukla; Kundu, Soumya Kanti; Bhattacharyya, Nirmal Kumar; Bhattacharyya, Pranab Kumar; Kundu, Anup Kumar

    2014-01-01

    Prostate gland is a fibromusculoglandular structure situated at the neck of urinary bladder. So, enlargement or growth of prostate due to nodular hyperplasia (NHP) or prostatic intraepithelial neoplasia (PIN) or adenocarcinoma may give rise to bladder outlet obstruction. Malignant growth i.e., PIN or adenocarcinoma cases are associated with increased blood level of prostate-specific antigen (PSA) and increased expression of different sex-steroid receptors because the growth is dependent on the interactions of androgen, progesterone and estrogen. The aim of our study is to correlate the histopathology, PSA levels and expression of different sex-steroid receptors by immunohistochemistry in different prostatic growth lesions. Among the total 50 cases received, inclusive of transurethral resection of prostate (TURP), transrectal ultrasound-guided biopsy and radical prostatectomy, 34 cases were diagnosed as NHP, 4 cases as PIN and 12 cases as adenocarcinoma histopathologically. Serum PSA values above 10 ng/ml were seen in 2 cases of PIN and 11 cases of adenocarcinoma and none of NHP. Estrogen receptor (ER) () expressions were negative in all cases. Progesterone receptor (PR) expressions were strongly positive in 35% cases of both NHP and adenocarcinoma, whereas androgen receptor (AR) expressions were strong among all cases of adenocarcinoma and only in four cases of NHP. By observing these findings it can be suggested that antiandrogen and antiprogesterone therapy simultaneously will do better than antiandrogen alone in treating prostatic growth lesions.

  15. Independent signaling by Drosophila insulin receptor for axon guidance and growth.

    Science.gov (United States)

    Li, Caroline R; Guo, Dongyu; Pick, Leslie

    2013-01-01

    The Drosophila insulin receptor (DInR) regulates a diverse array of biological processes including growth, axon guidance, and sugar homeostasis. Growth regulation by DInR is mediated by Chico, the Drosophila homolog of vertebrate insulin receptor substrate proteins IRS1-4. In contrast, DInR regulation of photoreceptor axon guidance in the developing visual system is mediated by the SH2-SH3 domain adaptor protein Dreadlocks (Dock). In vitro studies by others identified five NPXY motifs, one in the juxtamembrane region and four in the signaling C-terminal tail (C-tail), important for interaction with Chico. Here we used yeast two-hybrid assays to identify regions in the DInR C-tail that interact with Dock. These Dock binding sites were in separate portions of the C-tail from the previously identified Chico binding sites. To test whether these sites are required for growth or axon guidance in whole animals, a panel of DInR proteins, in which the putative Chico and Dock interaction sites had been mutated individually or in combination, were tested for their ability to rescue viability, growth and axon guidance defects of dinr mutant flies. Sites required for viability were identified. Unexpectedly, mutation of both putative Dock binding sites, either individually or in combination, did not lead to defects in photoreceptor axon guidance. Thus, either sites also required for viability are necessary for DInR function in axon guidance and/or there is redundancy built into the DInR/Dock interaction such that Dock is able to interact with multiple regions of DInR. We also found that simultaneous mutation of all five NPXY motifs implicated in Chico interaction drastically decreased growth in both male and female adult flies. These animals resembled chico mutants, supporting the notion that DInR interacts directly with Chico in vivo to control body size. Mutation of these five NPXY motifs did not affect photoreceptor axon guidance, segregating the roles of DInR in the

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

    International Nuclear Information System (INIS)

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

    1988-01-01

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

  17. miR-29a suppresses MCF-7 cell growth by downregulating tumor necrosis factor receptor 1.

    Science.gov (United States)

    Zhao, Yiling; Yang, Fenghua; Li, Wenyuan; Xu, Chunyan; Li, Li; Chen, Lifei; Liu, Yancui; Sun, Ping

    2017-02-01

    Tumor necrosis factor receptor 1 is the main receptor mediating many tumor necrosis factor-alpha-induced cellular events. Some studies have shown that tumor necrosis factor receptor 1 promotes tumorigenesis by activating nuclear factor-kappa B signaling pathway, while other studies have confirmed that tumor necrosis factor receptor 1 plays an inhibitory role in tumors growth by inducing apoptosis in breast cancer. Therefore, the function of tumor necrosis factor receptor 1 in breast cancer requires clarification. In this study, we first found that tumor necrosis factor receptor 1 was significantly increased in human breast cancer tissues and cell lines, and knockdown of tumor necrosis factor receptor 1 by small interfering RNA inhibited cell proliferation by arresting the cell cycle and inducing apoptosis. In addition, miR-29a was predicted as a regulator of tumor necrosis factor receptor 1 by TargetScan and was shown to be inversely correlated with tumor necrosis factor receptor 1 expression in human breast cancer tissues and cell lines. Luciferase reporter assay further confirmed that miR-29a negatively regulated tumor necrosis factor receptor 1 expression by binding to the 3' untranslated region. In our functional study, miR-29a overexpression remarkably suppressed cell proliferation and colony formation, arrested the cell cycle, and induced apoptosis in MCF-7 cell. Furthermore, in combination with tumor necrosis factor receptor 1 transfection, miR-29a significantly reversed the oncogenic role caused by tumor necrosis factor receptor 1 in MCF-7 cell. In addition, we demonstrated that miR-29a suppressed MCF-7 cell growth by inactivating the nuclear factor-kappa B signaling pathway and by decreasing cyclinD1 and Bcl-2/Bax protein levels. Taken together, our results suggest that miR-29a is an important regulator of tumor necrosis factor receptor 1 expression in breast cancer and functions as a tumor suppressor by targeting tumor necrosis factor receptor 1 to

  18. Expression and functional role of orphan receptor GPR158 in prostate cancer growth and progression.

    Directory of Open Access Journals (Sweden)

    Nitin Patel

    Full Text Available Prostate cancer (PCa is the second-leading cause of cancer-related mortality, after lung cancer, in men from developed countries. In its early stages, primary tumor growth is dependent on androgens, thus generally can be controlled by androgen deprivation therapy (ADT. Eventually however, the disease progresses to castration-resistant prostate cancer (CRPC, a lethal form in need of more effective treatments. G-protein coupled receptors (GPCRs comprise a large clan of cell surface proteins that have been implicated as therapeutic targets in PCa growth and progression. The findings reported here provide intriguing evidence of a role for the newly characterized glutamate family member GPR158 in PCa growth and progression. We found that GPR158 promotes PCa cell proliferation independent of androgen receptor (AR functionality and that this requires its localization in the nucleus of the cell. This suggests that GPR158 acts by mechanisms different from other GPCRs. GPR158 expression is stimulated by androgens and GPR158 stimulates AR expression, implying a potential to sensitize tumors to low androgen conditions during ADT via a positive feedback loop. Further, we found GPR158 expression correlates with a neuroendocrine (NE differentiation phenotype and promotes anchorage-independent colony formation implying a role for GPR158 in therapeutic progression and tumor formation. GPR158 expression was increased at the invading front of prostate tumors that formed in the genetically defined conditional Pten knockout mouse model, and co-localized with elevated AR expression in the cell nucleus. Kaplan-Meier analysis on a dataset from the Memorial Sloan Kettering cancer genome portal showed that increased GPR158 expression in tumors is associated with lower disease-free survival. Our findings strongly suggest that pharmaceuticals targeting GPR158 activities could represent a novel and innovative approach to the prevention and management of CRPC.

  19. The SOCS2 ubiquitin ligase complex regulates growth hormone receptor levels.

    Directory of Open Access Journals (Sweden)

    Mattias Vesterlund

    Full Text Available Growth Hormone is essential for the regulation of growth and the homeostatic control of intermediary metabolism. GH actions are mediated by the Growth Hormone Receptor; a member of the cytokine receptor super family that signals chiefly through the JAK2/STAT5 pathway. Target tissue responsiveness to GH is under regulatory control to avoid excessive and off-target effects upon GHR activation. The suppressor of cytokine signalling 2 (SOCS is a key regulator of GHR sensitivity. This is clearly shown in mice where the SOCS2 gene has been inactivated, which show 30-40% increase in body length, a phenotype that is dependent on endogenous GH secretion. SOCS2 is a GH-stimulated, STAT5b-regulated gene that acts in a negative feedback loop to downregulate GHR signalling. Since the biochemical basis for these actions is poorly understood, we studied the molecular function of SOCS2. We demonstrated that SOCS2 is part of a multimeric complex with intrinsic ubiquitin ligase activity. Mutational analysis shows that the interaction with Elongin B/C controls SOCS2 protein turnover and affects its molecular activity. Increased GHR levels were observed in livers from SOCS2⁻/⁻ mice and in the absence of SOCS2 in in vitro experiments. We showed that SOCS2 regulates cellular GHR levels through direct ubiquitination and in a proteasomally dependent manner. We also confirmed the importance of the SOCS-box for the proper function of SOCS2. Finally, we identified two phosphotyrosine residues in the GHR to be responsible for the interaction with SOCS2, but only Y487 to account for the effects of SOCS2. The demonstration that SOCS2 is an ubiquitin ligase for the GHR unveils the molecular basis for its physiological actions.

  1. Single-domain antibodies that compete with the natural ligand fibroblast growth factor block the internalization of the fibroblast growth factor receptor 1

    International Nuclear Information System (INIS)

    Highlights: → Recombinant antibodies for FGFR1 were isolated from a llama naive library in VHH format. → These antibodies compete with the natural ligand FGF-2 for the same epitope on FGFR1. → The antibody competition inhibits the FGF-2-dependent internalization of FGFR1. -- Abstract: Single-domain antibodies in VHH format specific for fibroblast growth factor receptor 1 (FGFR1) were isolated from a phage-display llama naive library. In particular, phage elution in the presence of the natural receptor ligand fibroblast growth factor (FGF) allowed for the identification of recombinant antibodies that compete with FGF for the same region on the receptor surface. These antibodies posses a relatively low affinity for FGFR1 and were never identified when unspecific elution conditions favoring highly affine binders were applied to panning procedures. Two populations of competitive antibodies were identified that labeled specifically the receptor-expressing cells in immunofluorescence and recognize distinct epitopes. Antibodies from both populations effectively prevented FGF-dependent internalization and nuclear accumulation of the receptor in cultured cells. This achievement indicates that these antibodies have a capacity to modulate the receptor physiology and, therefore, constitute powerful reagents for basic research and a potential lead for therapeutic applications.

  2. Single-domain antibodies that compete with the natural ligand fibroblast growth factor block the internalization of the fibroblast growth factor receptor 1

    Energy Technology Data Exchange (ETDEWEB)

    Veggiani, Gianluca; Ossolengo, Giuseppe; Aliprandi, Marisa; Cavallaro, Ugo [IFOM-IEO Campus, Via Adamello 16, 20139 Milano (Italy); Marco, Ario de, E-mail: ario.demarco@ung.si [IFOM-IEO Campus, Via Adamello 16, 20139 Milano (Italy); Dept. Environmental Sciences, University of Nova Gorica (UNG), Vipavska 13, P.O. Box 301-SI-5000, Rozna Dolina, Nova Gorica (Slovenia)

    2011-05-20

    Highlights: {yields} Recombinant antibodies for FGFR1 were isolated from a llama naive library in VHH format. {yields} These antibodies compete with the natural ligand FGF-2 for the same epitope on FGFR1. {yields} The antibody competition inhibits the FGF-2-dependent internalization of FGFR1. -- Abstract: Single-domain antibodies in VHH format specific for fibroblast growth factor receptor 1 (FGFR1) were isolated from a phage-display llama naive library. In particular, phage elution in the presence of the natural receptor ligand fibroblast growth factor (FGF) allowed for the identification of recombinant antibodies that compete with FGF for the same region on the receptor surface. These antibodies posses a relatively low affinity for FGFR1 and were never identified when unspecific elution conditions favoring highly affine binders were applied to panning procedures. Two populations of competitive antibodies were identified that labeled specifically the receptor-expressing cells in immunofluorescence and recognize distinct epitopes. Antibodies from both populations effectively prevented FGF-dependent internalization and nuclear accumulation of the receptor in cultured cells. This achievement indicates that these antibodies have a capacity to modulate the receptor physiology and, therefore, constitute powerful reagents for basic research and a potential lead for therapeutic applications.

  3. Growth Hormone Secretagogue Receptor (GHS-R1a) Knockout Mice Exhibit Improved Spatial Memory and Deficits in Contextual Memory

    OpenAIRE

    Albarran-Zeckler, Rosie G.; Brantley, Alicia Faruzzi; Smith, Roy G.

    2012-01-01

    Although the hormone ghrelin is best known for its stimulatory effect on appetite and regulation of growth hormone release, it is also reported to have beneficial effects on learning and memory formation in mice. Nevertheless, controversy exists about whether endogenous ghrelin acts on its receptors in extra-hypothalamic areas of the brain. The ghrelin receptor (GHS-R1a) is co-expressed in neurons that express dopamine receptor type-1 (DRD1a) and type-2 (DRD2), and we have shown that a subset...

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

    International Nuclear Information System (INIS)

    Liu, Gang; Hitomi, Hirofumi; Hosomi, Naohisa; Lei, Bai; Nakano, Daisuke; Deguchi, Kazushi; Mori, Hirohito; Masaki, Tsutomu; Ma, Hong; Griendling, Kathy K.; Nishiyama, Akira

    2011-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-10-15

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

  6. Selective Endothelin-B Receptor Stimulation Increases Vascular Endothelial Growth Factor in the Rat Brain during Postnatal Development.

    Science.gov (United States)

    Leonard, M G; Prazad, P; Puppala, B; Gulati, A

    2015-11-01

    Endothelin, vascular endothelial growth factor and nerve growth factor play important roles in development of the central nervous system. ET(B) receptors have been shown to promote neurovascular remodeling in the adult ischemic brain through an increase in VEGF and NGF. It is possible that ET(B) receptors may be involved in postnatal development of the brain through VEGF and NGF. In the present study, the brains of male rat pups on postnatal days 1, 7, 14 and 28 were analyzed for expression of ET(B) receptors, VEGF and NGF. In order to determine the effect of ET(B) receptor stimulation, a separate group of pups were administered saline or ET(B) receptor agonist, IRL-1620, on day 21, and their brains were analyzed on day 28. The intensity of ET(B) receptor and VEGF staining in the vasculature as well as the number of blood vessels of normal pups increased with age and was significantly higher on postnatal day 14 compared to day 1 and day 7. In contrast, both ET(B) and NGF staining intensity in the cortex and subventricular zones decreased (Pbrain (Pdevelopment of the CNS and selective stimulation of ET(B) receptors enhances VEGF but not NGF in the postnatal rat brain. © Georg Thieme Verlag KG Stuttgart · New York.

  7. Emerging role of epidermal growth factor receptor inhibition in therapy for advanced malignancy: focus on NSCLC

    International Nuclear Information System (INIS)

    Langer, Corey J.

    2004-01-01

    Combination chemotherapy regimens have emerged as the standard approach in advanced non-small-cell lung cancer. Meta-analyses have demonstrated a 2-month increase in median survival after platinum-based therapy vs. best supportive care, and an absolute 10% improvement in the 1-year survival rate. Just as importantly, cytotoxic therapy has produced benefits in symptom control and quality of life. Newer agents, including the taxanes, vinorelbine, gemcitabine, and irinotecan, have expanded our therapeutic options in the treatment of advanced non-small-cell lung cancer. Despite their contributions, we have reached a therapeutic plateau, with response rates seldom exceeding 30-40% in cooperative group studies and 1-year survival rates stable between 30% and 40%. It is doubtful that substituting one agent for another in various combinations will lead to any further improvement in these rates. The thrust of current research has focused on targeted therapy, and epidermal growth factor receptor inhibition is one of the most promising clinical strategies. Epidermal growth factor receptor inhibitors currently under investigation include the small molecules gefitinib (Iressa, ZD1839) and erlotinib (Tarceva, OSI-774), as well as monoclonal antibodies such as cetuximab (IMC-225, Erbitux). Agents that have only begun to undergo clinical evaluation include CI-1033, an irreversible pan-erbB tyrosine kinase inhibitor, and PKI166 and GW572016, both examples of dual kinase inhibitors (inhibiting epidermal growth factor receptor and Her2). Preclinical models have demonstrated synergy for all these agents in combination with either chemotherapy or radiotherapy, leading to great enthusiasm regarding their ultimate contribution to lung cancer therapy. However, serious clinical challenges persist. These include the identification of the optimal dose(s); the proper integration of these agents into popular, established cytotoxic regimens; and the selection of the optimal setting(s) in which

  8. Androgen Receptors Expression in Pituitary of Male Viscacha in relation to Growth and Reproductive Cycle

    Directory of Open Access Journals (Sweden)

    Verónica Palmira Filippa

    2015-01-01

    Full Text Available The aim of this work was to study the androgen receptors (AR expression in pituitary pars distalis (PD of male viscachas in relation to growth and reproductive cycle. AR were detected by immunocytochemistry and quantified by image analysis. Pituitary glands from fetus, immature, prepubertal, and adult viscachas during their reproductive cycle were used. In the fetal PD, the immunoreactivity (ir was mainly cytoplasmic. In immature and prepubertal animals, AR-ir was cytoplasmic (ARc-ir and nuclear (ARn-ir in medial region. In adult animals, ARn-ir cells were numerous at caudal end. AR regionalization varied between the PD zones in relation to growth. In immature animals, the ARn-ir increased whereas the cytoplasmic expression decreased in relation to the fetal glands. The percentage of ARc-ir cells increased in prepubertal animals whereas the nuclear AR expression was predominant in adult viscachas. The AR expression changed in adults, showing minimum percentage in the gonadal regression period. The variation of nuclear AR expression was directly related with testosterone concentration. These results demonstrated variations in the immunostaining pattern, regionalization, and number of AR-ir cells throughout development, growth, and reproductive cycle, suggesting the involvement of AR in the regulation of the pituitary activity of male viscacha.

  9. Testosterone regulates keratin 33B expression in rat penis growth through androgen receptor signaling.

    Science.gov (United States)

    Ma, Yan-Min; Wu, Kai-Jie; Dang, Qiang; Shi, Qi; Gao, Yang; Guo, Peng; Xu, Shan; Wang, Xin-Yang; He, Da-Lin; Gong, Yong-Guang

    2014-01-01

    Androgen therapy is the mainstay of treatment for the hypogonadotropic hypogonadal micropenis because it obviously enhances penis growth in prepubescent microphallic patients. However, the molecular mechanisms of androgen treatment leading to penis growth are still largely unknown. To clarify this well-known phenomenon, we successfully generated a castrated male Sprague Dawley rat model at puberty followed by testosterone administration. Interestingly, compared with the control group, testosterone treatment stimulated a dose-dependent increase of penis weight, length, and width in castrated rats accompanied with a dramatic recovery of the pathological changes of the penis. Mechanistically, testosterone administration substantially increased the expression of androgen receptor (AR) protein. Increased AR protein in the penis could subsequently initiate transcription of its target genes, including keratin 33B (Krt33b). Importantly, we demonstrated that KRT33B is generally expressed in the rat penis and that most KRT33B expression is cytoplasmic. Furthermore, AR could directly modulate its expression by binding to a putative androgen response element sequence of the Krt33b promoter. Overall, this study reveals a novel mechanism facilitating penis growth after testosterone treatment in precastrated prepubescent animals, in which androgen enhances the expression of AR protein as well as its target genes, such as Krt33b.

  10. Testosterone regulates keratin 33B expression in rat penis growth through androgen receptor signaling

    Directory of Open Access Journals (Sweden)

    Yan-Min Ma

    2014-12-01

    Full Text Available Androgen therapy is the mainstay of treatment for the hypogonadotropic hypogonadal micropenis because it obviously enhances penis growth in prepubescent microphallic patients. However, the molecular mechanisms of androgen treatment leading to penis growth are still largely unknown. To clarify this well-known phenomenon, we successfully generated a castrated male Sprague Dawley rat model at puberty followed by testosterone administration. Interestingly, compared with the control group, testosterone treatment stimulated a dose-dependent increase of penis weight, length, and width in castrated rats accompanied with a dramatic recovery of the pathological changes of the penis. Mechanistically, testosterone administration substantially increased the expression of androgen receptor (AR protein. Increased AR protein in the penis could subsequently initiate transcription of its target genes, including keratin 33B (Krt33b. Importantly, we demonstrated that KRT33B is generally expressed in the rat penis and that most KRT33B expression is cytoplasmic. Furthermore, AR could directly modulate its expression by binding to a putative androgen response element sequence of the Krt33b promoter. Overall, this study reveals a novel mechanism facilitating penis growth after testosterone treatment in precastrated prepubescent animals, in which androgen enhances the expression of AR protein as well as its target genes, such as Krt33b.

  11. Amphiregulin triggered epidermal growth factor receptor activation confers in vivo crizotinib-resistance of EML4-ALK lung cancer and circumvention by epidermal growth factor receptor inhibitors.

    Science.gov (United States)

    Taniguchi, Hirokazu; Takeuchi, Shinji; Fukuda, Koji; Nakagawa, Takayuki; Arai, Sachiko; Nanjo, Shigeki; Yamada, Tadaaki; Yamaguchi, Hiroyuki; Mukae, Hiroshi; Yano, Seiji

    2017-01-01

    Crizotinib, a first-generation anaplastic lymphoma kinase (ALK) tyrosine-kinase inhibitor, is known to be effective against echinoderm microtubule-associated protein-like 4 (EML4)-ALK-positive non-small cell lung cancers. Nonetheless, the tumors subsequently become resistant to crizotinib and recur in almost every case. The mechanism of the acquired resistance needs to be deciphered. In this study, we established crizotinib-resistant cells (A925LPE3-CR) via long-term administration of crizotinib to a mouse model of pleural carcinomatous effusions; this model involved implantation of the A925LPE3 cell line, which harbors the EML4-ALK gene rearrangement. The resistant cells did not have the secondary ALK mutations frequently occurring in crizotinib-resistant cells, and these cells were cross-resistant to alectinib and ceritinib as well. In cell clone #2, which is one of the clones of A925LPE3-CR, crizotinib sensitivity was restored via the inhibition of epidermal growth factor receptor (EGFR) by means of an EGFR tyrosine-kinase inhibitor (erlotinib) or an anti-EGFR antibody (cetuximab) in vitro and in the murine xenograft model. Cell clone #2 did not have an EGFR mutation, but the expression of amphiregulin (AREG), one of EGFR ligands, was significantly increased. A knockdown of AREG with small interfering RNAs restored the sensitivity to crizotinib. These data suggest that overexpression of EGFR ligands such as AREG can cause resistance to crizotinib, and that inhibition of EGFR signaling may be a promising strategy to overcome crizotinib resistance in EML4-ALK lung cancer. © 2016 The Authors. Cancer Science published by John Wiley & Sons Australia, Ltd on behalf of Japanese Cancer Association.

  12. Growth hormone receptor C-terminal domains required for growth hormone-induced intracellular free Ca2+ oscillations and gene transcription

    DEFF Research Database (Denmark)

    Billestrup, N; Bouchelouche, P; Allevato, G

    1995-01-01

    The biological effects of growth hormone (GH) are initiated by its binding to the GH receptor (GHR) followed by association and activation of the tyrosine kinase JAK2. Here we report that GH can stimulate an increase in intracellular free Ca2+ concentration ([Ca2+]i) in cells expressing wild-type...

  13. Competitive RT-PCR Strategy for Quantitative Evaluation of the Expression of Tilapia (Oreochromis niloticus) Growth Hormone Receptor Type I

    Science.gov (United States)

    2009-01-01

    Quantization of gene expression requires that an accurate measurement of a specific transcript is made. In this paper, a quantitative reverse transcription-polymerase chain reaction (RT-PCR) by competition for tilapia growth hormone receptor type I is designed and validated. This experimental procedure was used to determine the abundance of growth hormone receptor type I transcript in different tilapia tissues. The results obtained with this developed competitive RT-PCR were similar to real-time PCR results reported recently. This protocol provides a reliable alternative, but less expensive than real-time PCR to quantify specific genes. PMID:19495916

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

    Directory of Open Access Journals (Sweden)

    Castelli Mauro

    2009-12-01

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

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

    Science.gov (United States)

    Tedesco, Karen L; Lockhart, A Craig; Berlin, Jordan D

    2004-10-01

    The epidermal growth factor receptor (EGFR) is a member of the family of transmembrane protein kinase receptors known as the erbB or HER receptor family. When activated, EGFR phosphorylates and activates other intracellular proteins that affect cell signaling pathways, cellular proliferation, control of apoptosis and angiogenesis. EGFR signaling is best thought of as a network of activating and inactivating proteins with EGFR as the entry point into the network. EGFR overexpression occurs in most GI malignancies and while data are not entirely consistent, EGFR overexpression often confers a poor prognosis in those GI malignancies that have been studied. It often correlates with poorly differentiated histology, more advanced stage and other known poor prognostic markers. The EGFR is a tempting target because of its presence and overexpression on so many tumor types. However, downstream of the EGFR are several proteins that may be activated without EGFR thus allowing blockade to be overcome. Therefore, while blocking the activity of the EGFR protein appears to be a promising anticancer strategy, a simplistic strategy of blocking only EGFR is likely to only impact a minority of patients. It is time for the laboratory and clinical researchers to work closely together to develop this treatment strategy, moving back and forth from clinical to laboratory to best understand how to block this network effectively enough to produce a broader antitumor effect. While multiple methods of targeting the EGFR pathway are under development, including the inhibition of downstream proteins, only two modalities have entered clinical trials in GI malignancies: small molecule inhibitors of the intracellular kinase domain of EGFR and antibodies designed to block the extracellular ligand-binding domain of EGFR. EGFR inhibitors are still experimental in every GI malignancy with the notable exception of cetuximab that is approved for second or third-line therapy of metastatic colorectal

  16. Endocrine Parameters and Phenotypes of the Growth Hormone Receptor Gene Disrupted (GHR−/−) Mouse

    Science.gov (United States)

    List, Edward O.; Sackmann-Sala, Lucila; Berryman, Darlene E.; Funk, Kevin; Kelder, Bruce; Gosney, Elahu S.; Okada, Shigeru; Ding, Juan; Cruz-Topete, Diana

    2011-01-01

    Disruption of the GH receptor (GHR) gene eliminates GH-induced intracellular signaling and, thus, its biological actions. Therefore, the GHR gene disrupted mouse (GHR−/−) has been and is a valuable tool for helping to define various parameters of GH physiology. Since its creation in 1995, this mouse strain has been used by our laboratory and others for numerous studies ranging from growth to aging. Some of the most notable discoveries are their extreme insulin sensitivity in the presence of obesity. Also, the animals have an extended lifespan, which has generated a large number of investigations into the roles of GH and IGF-I in the aging process. This review summarizes the many results derived from the GHR−/− mice. We have attempted to present the findings in the context of current knowledge regarding GH action and, where applicable, to discuss how these mice compare to GH insensitivity syndrome in humans. PMID:21123740

  17. Mutation of the KIT (mast/stem cell growth factor receptor) protooncogene in human piebaldism

    Energy Technology Data Exchange (ETDEWEB)

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

    1991-10-01

    Piebaldism is an autosomal dominant genetic disorder characterized by congenital patches of skin and hair from which melanocytes are completely absent. A similar disorder of mouse, dominant white spotting (W), results from mutations of the c-Kit protooncogene, which encodes the receptor for mast/stem cell growth factor. The authors identified a KIT gene mutation in a proband with classic autosomal dominant piebaldism. This mutation results in a Gly {yields} Arg substitution at codon 664, within the tyrosine kinase domain. This substitution was not seen in any normal individuals and was completely linked to the piebald phenotype in the proband's family. Piebaldism in this family thus appears to be the human homologue to dominant white spotting (W) of the mouse.

  18. Expression of epithelial growth factor receptor in oral epithelial dysplastic lesions.

    Science.gov (United States)

    Rajeswari, Manickam Rajakili Chockalingam; Saraswathi, Thillai Rajasekaran

    2012-05-01

    The aim of the study was to assess the expression of epithelial growth factor receptor (EGFR) in normal oral mucosa and varying grades of oral epithelial dysplasia (OED) and to correlate these findings, with clinicopathologic features and findings on routine hematoxylin and eosin-stained (H and E) sections. Twenty-nine formalin-fixed, paraffin-embedded blocks of various grades of OED and 10 normal mucosa were stained with routine H and E and immunostained with EGFR by avidin-biotin method. The results showed a significant increase in the staining reactions in varying grades of dysplasia as compared with normal mucosa. EGFR can be considered as an early marker of a cell proliferation and maturation as well as early marker of epithelial dysplasia and onset of cancer in oral dysplasia. However, further studies with a larger sample size and continuous followup is suggested to determine its role and significance precisely.

  19. Lack of the type III epidermal growth factor receptor mutation in colorectal cancer

    DEFF Research Database (Denmark)

    Spindler, Karen-Lise Garm; Olsen, Dorte A.; Nielsen, Jens Nederby

    2006-01-01

    BACKGROUND: Epidermal growth factor receptor (EGFR) analysis by traditional immunohistochemistry does not provide clinicians with a reliable tool for the selection of patients to EGFR-targeted treatment in colorectal cancer (CRC). Alternative methods and further understanding of the EGFR signaling...... therapy. The aim of the present study was to investigate the presence of EGFRvIII in CRC by PCR and protein analysis. MATERIALS AND METHODS: The study included 79 colorectal cancer patients for PCR analysis and 50 patients for protein analysis by Western blots, in two different laboratories. RESULTS......: No type III mutations were detected in our material. CONCLUSION: The EGFRvIII mutations are rare in colorectal adenocarcinomas and overall probability does not appear to contribute to the malignant phenotype of this disease....

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

    Science.gov (United States)

    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. Copyright © 2015 Elsevier Inc. All rights reserved.

  1. Epidermal growth factor receptor is a preferred target for treating amyloid-β-induced memory loss.

    Science.gov (United States)

    Wang, Lei; Chiang, Hsueh-Cheng; Wu, Wenjuan; Liang, Bin; Xie, Zuolei; Yao, Xinsheng; Ma, Weiwei; Du, Shuwen; Zhong, Yi

    2012-10-09

    Current understanding of amyloid-β (Aβ) metabolism and toxicity provides an extensive list of potential targets for developing drugs for treating Alzheimer's disease. We took two independent approaches, including synaptic-plasticity-based analysis and behavioral screening of synthetic compounds, for identifying single compounds that are capable of rescuing the Aβ-induced memory loss in both transgenic fruit fly and transgenic mouse models. Two clinically available drugs and three synthetic compounds not only showed positive effects in behavioral tests but also antagonized the Aβ oligomers-induced activation of the epidermal growth factor receptor (EGFR). Such surprising converging outcomes from two parallel approaches lead us to conclude that EGFR is a preferred target for treating Aβ-induced memory loss.

  2. Transforming growth factor β receptor 1 is a new candidate prognostic biomarker after acute myocardial infarction

    Directory of Open Access Journals (Sweden)

    Devaux Yvan

    2011-12-01

    Full Text Available Abstract Background Prediction of left ventricular (LV remodeling after acute myocardial infarction (MI is clinically important and would benefit from the discovery of new biomarkers. Methods Blood samples were obtained upon admission in patients with acute ST-elevation MI who underwent primary percutaneous coronary intervention. Messenger RNA was extracted from whole blood cells. LV function was evaluated by echocardiography at 4-months. Results In a test cohort of 32 MI patients, integrated analysis of microarrays with a network of protein-protein interactions identified subgroups of genes which predicted LV dysfunction (ejection fraction ≤ 40% with areas under the receiver operating characteristic curve (AUC above 0.80. Candidate genes included transforming growth factor beta receptor 1 (TGFBR1. In a validation cohort of 115 MI patients, TGBFR1 was up-regulated in patients with LV dysfunction (P Conclusions We identified TGFBR1 as a new candidate prognostic biomarker after acute MI.

  3. Anticipating and managing the cutaneous side effects of epidermal growth factor receptor inhibitors.

    Science.gov (United States)

    Sinclair, Rod

    2014-03-01

    Epidermal growth factor receptor inhibitor (EGFRi) therapy for tumor suppression produces significant cutaneous toxicity that may necessitate dose reduction or treatment cessation. This manuscript aims to describe the skin toxicity associated with these agents and equip oncologists with the tools to best manage these patients. A literature review of skin toxicity associated with EGFRi was conducted by a clinical dermatologist experienced in the management of these patients and a management strategy developed for EGFRi skin toxicity The sequence of development of EGFRi cutaneous toxicity is predictable. Many skin side effects can be ameliorated by prophylactic therapy. Management of established skin toxicity is complex and needs to be continued throughout the period of EGFRi drug treatment. Early referral to a dermatologist experienced in the management of these patients is recommended. © 2014 Wiley Publishing Asia Pty Ltd.

  4. 99m Tc-anti-epidermal growth factor receptor nanobody for tumor imaging.

    Science.gov (United States)

    Piramoon, Majid; Hosseinimehr, Seyed Jalal; Omidfar, Kobra; Noaparast, Zohreh; Abedi, Seyed Mohammad

    2017-04-01

    Nanobodies are important biomolecules for tumor targeting. In this study, we synthesized and labeled anti-epidermal growth factor receptor (EGFR) nanobody OA-cb6 with 99m Tc(CO) 3 + and evaluated its characteristics for targeting the EGFR in the A431 human epidermal carcinoma cell line. Nanobody radiolabeling was achieved with high yield and radiochemical purity, and the radioconjugate was stable. Biodistribution results in nude mice exhibited a favorable tumor-to-muscle ratio at 4-hr postinjection, and tumor location was visualized at 4 hr after injection of radiolabeled nanobody. Our result showed that the OA-cb6- 99m Tc-tricarbonyl radiolabeled nanobody is a promising radiolabeled biomolecule for tumor imaging in cancers with high EGFR overexpression. © 2016 John Wiley & Sons A/S.

  5. Vascular Endothelial Growth Factor Receptor 3 Controls Neural Stem Cell Activation in Mice and Humans

    Directory of Open Access Journals (Sweden)

    Jinah Han

    2015-02-01

    Full Text Available Neural stem cells (NSCs continuously produce new neurons within the adult mammalian hippocampus. NSCs are typically quiescent but activated to self-renew or differentiate into neural progenitor cells. The molecular mechanisms of NSC activation remain poorly understood. Here, we show that adult hippocampal NSCs express vascular endothelial growth factor receptor (VEGFR 3 and its ligand VEGF-C, which activates quiescent NSCs to enter the cell cycle and generate progenitor cells. Hippocampal NSC activation and neurogenesis are impaired by conditional deletion of Vegfr3 in NSCs. Functionally, this is associated with compromised NSC activation in response to VEGF-C and physical activity. In NSCs derived from human embryonic stem cells (hESCs, VEGF-C/VEGFR3 mediates intracellular activation of AKT and ERK pathways that control cell fate and proliferation. These findings identify VEGF-C/VEGFR3 signaling as a specific regulator of NSC activation and neurogenesis in mammals.

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

    International Nuclear Information System (INIS)

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

    2008-01-01

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

  7. Multimodular biosensors reveal a novel platform for activation of G proteins by growth factor receptors.

    Science.gov (United States)

    Midde, Krishna K; Aznar, Nicolas; Laederich, Melanie B; Ma, Gary S; Kunkel, Maya T; Newton, Alexandra C; Ghosh, Pradipta

    2015-03-03

    Environmental cues are transmitted to the interior of the cell via a complex network of signaling hubs. Receptor tyrosine kinases (RTKs) and trimeric G proteins are two such major signaling hubs in eukaryotes. Conventionally, canonical signal transduction via trimeric G proteins is thought to be triggered exclusively by G protein-coupled receptors. Here we used molecular engineering to develop modular fluorescent biosensors that exploit the remarkable specificity of bimolecular recognition, i.e., of both G proteins and RTKs, and reveal the workings of a novel platform for activation of G proteins by RTKs in single living cells. Comprised of the unique modular makeup of guanidine exchange factor Gα-interacting vesicle-associated protein (GIV)/girdin, a guanidine exchange factor that links G proteins to a variety of RTKs, these biosensors provide direct evidence that RTK-GIV-Gαi ternary complexes are formed in living cells and that Gαi is transactivated within minutes after growth factor stimulation at the plasma membrane. Thus, GIV-derived biosensors provide a versatile strategy for visualizing, monitoring, and manipulating the dynamic association of Gαi with RTKs for noncanonical transactivation of G proteins in cells and illuminate a fundamental signaling event regulated by GIV during diverse cellular processes and pathophysiologic states.

  8. Insulin and insulin-like growth factor receptors in the brain: physiological and pathological aspects.

    Science.gov (United States)

    Werner, Haim; LeRoith, Derek

    2014-12-01

    The involvement of insulin, the insulin-like growth factors (IGF1, IGF2) and their receptors in central nervous system development and function has been the focus of scientific interest for more than 30 years. The insulin-like peptides, both locally-produced proteins as well as those transported from the circulation into the brain via the blood-brain barrier, are involved in a myriad of biological activities. These actions include, among others, neuronal survival, neurogenes, angiogenesis, excitatory and inhibitory neurotransmission, regulation of food intake, and cognition. In recent years, a linkage between brain insulin/IGF1 and certain neuropathologies has been identified. Epidemiological studies have demonstrated a correlation between diabetes (mainly type 2) and Alzheimer׳s disease. In addition, an aberrant decline in IGF1 values was suggested to play a role in the development of Alzheimer׳s disease. The present review focuses on the expression and function of insulin, IGFs and their receptors in the brain in physiological and pathological conditions. Copyright © 2014 Elsevier B.V. and ECNP. All rights reserved.

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

    International Nuclear Information System (INIS)

    Diaz, Arlhee; Lage, Agustin

    2007-01-01

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

  10. Pertuzumab: Unprecedented benefit in human epidermal growth factor receptor 2-positive breast cancer

    Directory of Open Access Journals (Sweden)

    Amit Rauthan

    2015-01-01

    Full Text Available Human epidermal growth factor receptor 2 (HER2-positive breast cancer is a more aggressive subtype of breast cancer and targeting the HER2 receptor has proven effective in improving the prognosis of these patients. Pertuzumab, a recombinant humanized monoclonal antibody and the first in a class of HER2 dimerization inhibitors approved for treating HER2+ breast cancer. It blocks ligand-dependent heterodimerization and ligand-independent homodimerization of HER2 with other HER members. When used in combination with trastuzumab and taxane, pertuzumab complements the action of trastuzumab and results in a comprehensive blockade of HER2 signaling pathway. This review article traces the development of pertuzumab from concept to its current use in HER2+ breast cancer treatment. A search of Medical Literature Published since 2007 was performed in PubMed using the keywords "pertuzumab," "HER2+ breast cancer," "HER2 targeted therapy," "metastatic breast cancer," and in search engines for ongoing trials with pertuzumab and incidence of cancer and breast cancer in India. A total of 35 publications and abstracts from the American Society of Clinical Oncology were selected for this review. Pertuzumab is approved in combination with trastuzumab and docetaxel for the treatment of patients with HER2+ metastatic BC, who have not received prior anti-HER2 therapy or chemotherapy for metastatic disease. The dual HER2 blockade of pertuzumab and trastuzumab is now accepted worldwide as a standard of care by various guidelines.

  11. Alterations in epidermal growth factor receptors 1 and 2 in esophageal squamous cell carcinomas.

    Science.gov (United States)

    Gonzaga, Isabela Martins; Soares-Lima, Sheila Coelho; de Santos, Paulo Thiago Souza; Blanco, Tania Cristina Moita; de Reis, Bruno Souza Bianchi; Quintella, Danielle Carvalho; de Oliveira, Ivanir Martins; de Faria, Paulo Antonio Silvestre; Kruel, Cleber Dario Pinto; Andreollo, Nelson Adami; de Simão, Tatiana Almeida; Pinto, Luis Felipe Ribeiro

    2012-12-04

    Esophageal squamous cell carcinoma (ESCC) shows a 5-year survival rate below 10%, demonstrating the urgency in improving its treatment. Alterations in epidermal growth factor receptors are closely related to malignancy transformation in a number of tumors and recent successful targeted therapies have been directed to these molecules. Therefore, in this study, we analyzed the expression of EGFR and HER2 and evaluated EGFR mutation profile as well as the presence of mutations in hotspots of KRAS and BRAF in ESCC patients. We performed RT-qPCR, immunohistochemistry and Fluorescent in situ hybridization to determine EGFR and HER2 expression in ESCC patients, and direct sequencing and PCR-RFLP for mutations and polymorphism analysis. Our results showed an increased EGFR mRNA expression in tumors compared to surrounding tissue (p T) in 2.1% of the patients, and at codon 787 (G>A) in 79.2% of the cases. This last polymorphism was also evaluated in 304 healthy controls, which presented a similar frequency (73.7%) in comparison with ESCC patients. The absence of mutations of EGFR, KRAS and BRAF as well as the overexpression of EGFR and HER2 in less than 10% of the patients suggest that this signaling pathway is altered in only a small proportion of patients with ESCC. HER receptors target therapies may have the potential to be effective in only a minor fraction of patients with ESCC.

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

    Directory of Open Access Journals (Sweden)

    Devipriyaa B. Sundaram

    2011-12-01

    Full Text Available Objectives: The Insulin-like growth factor-I receptor (IGF-1R plays critical roles in cancer development, proliferation, motility and survival. IGF-1R over expression is frequently found in various tumours and is often associated with an aggressive phenotype. Hence, the aim of the present study was to examine the expression of IGF-1R in normal oral mucosa, fibroepithelial polyps, dysplastic oral mucosa and well-differentiated squamous cell carcinomas.Materials and methods: A 3-layered streptavidin peroxidase immunohistochemical method was used to detect the expression of IGF-1R in normal oral mucosa, fibroepithelial polyps, dysplastic oral mucosa and well-differentiated squamous cell carcinomas.Results: All squamous cell carcinomas (15 out of 15 patients showed intense immunoreactivity for IGF-1R. Moderate immunoreactivity was seen in dysplastic oral lesions (12 out of 12 lesions with positive staining in the prickle cell layer. The staining distribution in the benign lesions (14 out of 14 lesions was weaker and similar to that seen in normal oral mucosa (10 out of 10 samples when compared to squamous cell carcinomas and dysplastic lesions.Conclusions: Our results demonstrate increased IGF-1 receptor expression in oral squamous cell carcinomas which suggests that IGF-1 may have an important role in the development of oral cancer. J Clin Exp Invest 2011; 2 (4: 354-361

  13. Mechanism for activation of mutated epidermal growth factor receptors in lung cancer.

    Science.gov (United States)

    Red Brewer, Monica; Yun, Cai-Hong; Lai, Darson; Lemmon, Mark A; Eck, Michael J; Pao, William

    2013-09-17

    The initiation of epidermal growth factor receptor (EGFR) kinase activity proceeds via an asymmetric dimerization mechanism in which a "donor" tyrosine kinase domain (TKD) contacts an "acceptor" TKD, leading to its activation. In the context of a ligand-induced dimer, identical wild-type EGFR TKDs are thought to assume the donor or acceptor roles in a random manner. Here, we present biochemical reconstitution data demonstrating that activated EGFR mutants found in lung cancer preferentially assume the acceptor role when coexpressed with WT EGFR. Mutated EGFRs show enhanced association with WT EGFR, leading to hyperphosphorylation of the WT counterpart. Mutated EGFRs also hyperphosphorylate the related erythroblastic leukemia viral oncogene (ErbB) family member, ErbB-2, in a similar manner. This directional "superacceptor activity" is particularly pronounced in the drug-resistant L834R/T766M mutant. A 4-Å crystal structure of this mutant in the active conformation reveals an asymmetric dimer interface that is essentially the same as that in WT EGFR. Asymmetric dimer formation induces an allosteric conformational change in the acceptor subunit. Thus, superacceptor activity likely arises simply from a lower energetic cost associated with this conformational change in the mutant EGFR compared with WT, rather than from any structural alteration that impairs the donor role of the mutant. Collectively, these findings define a previously unrecognized mode of mutant-specific intermolecular regulation for ErbB receptors, knowledge of which could potentially be exploited for therapeutic benefit.

  14. The origin of the p.E180 growth hormone receptor gene mutation.

    Science.gov (United States)

    Ostrer, Harry

    2016-06-01

    Laron syndrome, an autosomal recessive condition of extreme short stature, is caused by the absence or dysfunction of the growth hormone receptor. A recurrent mutation in the GHR gene, p.E180, did not alter the encoded amino acid, but activated a cryptic splice acceptor resulting in a receptor protein with an 8-amino acid deletion in the extracellular domain. This mutation has been observed among Sephardic Jews and among individuals in Ecuador, Brazil and Chile, most notably in a large genetic isolate in Loja, Ecuador. A common origin has been postulated based on a shared genetic background of markers flanking this mutation, suggesting that the Lojanos (and others) may have Sephardic (Converso) Jewish ancestry. Analysis of the population structure of Lojanos based on genome-wide analysis demonstrated European, Sephardic Jewish and Native American ancestry in this group. X-autosomal comparison and monoallelic Y chromosomal and mitochondrial genetic analysis demonstrated gender-biased admixture between Native American women and European and Sephardic Jewish men. These findings are compatible with the co-occurrence of the Inquisition and the colonization of the Americas, including Converso Jews escaping the Inquisition in the Iberian Peninsula. Although not found among Lojanos, Converso Jews also brought founder mutations to contemporary Hispanic and Latino populations in the BRCA1 (c.68_69delAG) and BLM (c.2207_2212delATCTGAinsTAGATTC) genes. Copyright © 2015 Elsevier Ltd. All rights reserved.

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

    Science.gov (United States)

    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.

  16. Heterodimerization of wild-type and mutant fibroblast growth factor receptors in cell-derived vesicles

    Science.gov (United States)

    Hristova, Kalina; Del Piccolo, Nuala; Sarabipour, Sarvenaz

    The activity of receptor tyrosine kinases (RTKs) is controlled through their lateral dimerization in the plasma membrane. RTKs are believed to form both homodimers and heterodimers, and the different dimers are believed to play unique roles in cell signaling. However, RTK heterodimers remain poorly characterized, as compared to homodimers, due to limitations in current experimental methods. Here, we develop a Förster Resonance Energy Transfer (FRET)-based methodology to assess the thermodynamics of hetero-interactions in the plasma membrane. To demonstrate the utility of the methodology, we use it to study the hetero-interactions between three Fibroblast Growth Factor Receptors - FGFR1, FGFR2, and FGFR3 - in the absence of ligand. Our results show that all possible FGFR heterodimers form, suggesting that the biological roles of FGFR heterodimers may be as significant as the homodimer roles. We further investigate the effect of two pathogenic point mutations in FGFR3 (A391E and G380R) on heterodimerization. We show that each of these mutations stabilize most of the heterodimers, with the largest effects observed for FGFR3 wild-type/mutant heterodimers. We thus demonstrate that the methodology presented here can yield new knowledge about RTK interactions and can further our understanding of signal transduction across the plasma membrane..

  17. Prognostic value of insulin- like growth factor-I receptor expression in renal cell carcinoma

    Directory of Open Access Journals (Sweden)

    Sichani Mehrdad

    2010-01-01

    Full Text Available The Insulin-Like growth factor-I receptor (IGF-IR, a tyrosine-kinas receptor over expressed in many tumor cell lines and in some human tumors, plays a critical role in trans-formation, tumorigenicity and metastasis. The aim of the present study is to investigate the role of IGF-IR expression as a prognostic factor in RCC. This study was conducted in a historical cohort of 82 patients who had RCC treated with radical nephrectomy from 1994 to 2005. Specimens were reevaluated with regard to histological subtype, nuclear grade, stage and IGF-IR expression. The IGF-IR stain was semi- quantitatively evaluated using the Allred score system. Kaplan-Meier analysis demonstrated a significant positive correlation between Fuhrman nuclear grade and IGF-IR Allred score (P< 0.0001. Survival in patients with score IGF-I ≤ 4 was 90.21 month and in patients with score IGF-1R> 4 was 33.39 month (P Value < 0.0001. Cox regression analysis in-dicated that expression of IGF-IR is a prognostic factor in patients with RCC (P Value < 0.0001, odds Ratio = 2.38. In conclusion, a statistically significant correlation was demonstrated between IGF-IR expression and Fuhrman nuclear grading and survival in patients with RCC. In stage-by-stage and grade-by-grade analysis; however, it seems that we cannot consider IGF-IR as an inde-pendent prognostic factor.

  18. Prognostic value of insulin- like growth factor-I receptor expression in renal cell carcinoma.

    Science.gov (United States)

    Sichani, Mehrdad Mohammadi; Yazdi, Fateme Sarreshtedar; Moghaddam, Noushin Afshar; Chehrei, Ali; Kabiri, Mahmud; Naeimi, Amin; Taheri, Diana

    2010-01-01

    The insulin-like growth factor-I receptor (IGF-IR), a tyrosine kinase receptor over expressed in many tumor cell lines and in some human tumors, plays a critical role in transformation, tumorigenicity and metastasis. The aim of the present study is to investigate the role of IGF-IR expression as a prognostic factor in RCC. This study was conducted in a historical cohort of 82 patients who had RCC treated with radical nephrectomy from 1994 to 2005. Specimens were reevaluated with regard to histological subtype, nuclear grade, stage and IGF-IR expression. The IGF-IR stain was semi-quantitatively evaluated using the Allred score system. Kaplan-Meier analysis demonstrated a significant positive correlation between Fuhrman nuclear grade and IGF-IR Allred score (P 4 was 33.39 month (P Value < 0.0001). Cox regression analysis indicated that expression of IGF-IR is a prognostic factor in patients with RCC (P Value < 0.0001, odds Ratio = 2.38). In conclusion, a statistically significant correlation was demonstrated between IGF-IR expression and Fuhrman nuclear grading and survival in patients with RCC. In stage-by-stage and grade-by-grade analysis; however, it seems that we cannot consider IGF-IR as an independent prognostic factor.

  19. Lateral septum growth hormone secretagogue receptor affects food intake and motivation for sucrose reinforcement.

    Science.gov (United States)

    Terrill, Sarah J; Wall, Kaylee D; Medina, Nelson D; Maske, Calyn B; Williams, Diana L

    2018-03-28

    The hormone ghrelin promotes eating and is widely considered to be a hunger signal. Ghrelin receptors, growth hormone secretagogue receptors (GHSRs), are found in a number of specific regions throughout the brain, including the lateral septum (LS), an area not traditionally associated with the control of feeding. Here we investigated whether GHSRs in the LS play a role in the control of food intake. We examined the feeding effects of ghrelin and the GHSR antagonists ([D-Lys3]-GHRP-6 and JMV 2959), at doses subthreshold for effect when delivered to the lateral ventricle. Intra-LS ghrelin significantly increased chow intake during the mid-light phase, suggesting that pharmacologic activation of LS GHSRs promotes feeding. Conversely, GHSR antagonist delivered to the LS shortly before dark onset significantly reduced chow intake. These data support the hypothesis that exogenous and endogenous stimulation of GHSRs in the LS influence feeding. Ghrelin is known to affect motivation for food, and the dorsal subdivision of LS (dLS) has been shown to play a role in motivation. Thus, we investigated the role of dLS GHSRs in motivation for food reward by examining operant responding for sucrose on a progressive ratio (PR) schedule. Intra-dLS ghrelin increased PR responding for sucrose, while blockade of LS GHSRs did not affect responding in either a fed or fasted state. Together these findings for the first time substantiate the LS as a site of action for ghrelin signaling in the control of food intake.

  20. Brain Structure and Function Associated with Younger Adults in Growth Hormone Receptor-Deficient Humans.

    Science.gov (United States)

    Nashiro, Kaoru; Guevara-Aguirre, Jaime; Braskie, Meredith N; Hafzalla, George W; Velasco, Rico; Balasubramanian, Priya; Wei, Min; Thompson, Paul M; Mather, Mara; Nelson, Marvin D; Guevara, Alexandra; Teran, Enrique; Longo, Valter D

    2017-02-15

    Growth hormone receptor deficiency (GHRD) results in short stature, enhanced insulin sensitivity, and low circulating levels of insulin and insulin-like growth factor 1 (IGF-1). Previous studies in mice and humans suggested that GHRD has protective effects against age-related diseases, including cancer and diabetes. Whereas GHRD mice show improved age-dependent cognitive performance, the effect of GHRD on human cognition remains unknown. Using MRI, we compared brain structure, function, and connectivity between 13 people with GHRD and 12 unaffected relatives. We assessed differences in white matter microstructural integrity, hippocampal volume, subregional volumes, and cortical thickness and surface area of selected regions. We also evaluated brain activity at rest and during a hippocampal-dependent pattern separation task. The GHRD group had larger surface areas in several frontal and cingulate regions and showed trends toward larger dentate gyrus and CA1 regions of the hippocampus. They had lower mean diffusivity in the genu of the corpus callosum and the anterior thalamic tracts. The GHRD group showed enhanced cognitive performance and greater task-related activation in frontal, parietal, and hippocampal regions compared with controls. Furthermore, they had greater functional synchronicity of activity between the precuneus and the rest of the default mode network at rest. The results suggest that, compared with controls, GHRD subjects have brain structure and function that are more consistent with those observed in younger adults reported in previous studies. Further investigation may lead to improved understanding of underlying mechanisms and could contribute to the identification of treatments for age-related cognitive deficits. SIGNIFICANCE STATEMENT People and mice with growth hormone receptor deficiency (GHRD or Laron syndrome) are protected against age-related diseases including cancer and diabetes. However, in humans, it is unknown whether cognitive

  1. Epidermal Growth Factor Receptor activation promotes ADA3 acetylation through the AKT-p300 pathway.

    Science.gov (United States)

    Srivastava, Shashank; Mohibi, Shakur; Mirza, Sameer; Band, Hamid; Band, Vimla

    2017-08-18

    The ADA3 (Alteration/Deficiency in Activation 3) protein is an essential adaptor component of several Lysine Acetyltransferase (KAT) complexes involved in chromatin modifications. Previously, we and others have demonstrated a crucial role of ADA3 in cell cycle progression and in maintenance of genomic stability. Recently, we have shown that acetylation of ADA3 is key to its role in cell cycle progression. Here, we demonstrate that AKT activation downstream of Epidermal Growth Factor Receptor (EGFR) family proteins stimulation leads to phosphorylation of p300, which in turn promotes the acetylation of ADA3. Inhibition of upstream receptor tyrosine kinases (RTKs), HER1 (EGFR)/HER2 by lapatinib and the accompanying reduction of phospho-AKT levels led to a decrease in p300 phosphorylation and ADA3 protein levels. The p300/PCAF inhibitor garcinol also destabilized the ADA3 protein in a proteasome-dependent manner and an ADA3 mutant with K→R mutations exhibited a marked increase in half-life, consistent with opposite role of acetylation and ubiquitination of ADA3 on shared lysine residues. ADA3 knockdown led to cell cycle inhibitory effects, as well as apoptosis similar to those induced by lapatinib treatment of HER2+ breast cancer cells, as seen by accumulation of CDK inhibitor p27, reduction in mitotic marker pH3(S10), and a decrease in the S-phase marker PCNA, as well as the appearance of cleaved PARP. Taken together our results reveal a novel RTK-AKT-p300-ADA3 signaling pathway involved in growth factor-induced cell cycle progression.

  2. Epidermal growth factor receptor mutation in combination with expression of MIG6 alters gefitinib sensitivity

    Directory of Open Access Journals (Sweden)

    Tanaka Hiroshi

    2011-02-01

    Full Text Available Abstract Background Epidermal growth factor receptor (EGFR signaling plays an important role in the regulation of cell proliferation, survival, metastasis, and invasion in various tumors. Earlier studies showed that the EGFR is frequently overexpressed in non-small-cell lung cancer (NSCLC and EGFR mutations at specific amino acid residues in the kinase domain induce altered responsiveness to gefitinib, a small molecule EGFR tyrosine kinase inhibitor. However, the mechanism underlying the drug response modulated by EGFR mutation is still largely unknown. To elucidate drug response in EGFR signal transduction pathway in which complex dynamics of multiple molecules involved, a systematic approach is necessary. In this paper, we performed experimental and computational analyses to clarify the underlying mechanism of EGFR signaling and cell-specific gefitinib responsiveness in three H1299-derived NSCLC cell lines; H1299 wild type (H1299WT, H1299 with an overexpressed wild type EGFR (H1299EGFR-WT, and H1299 with an overexpressed mutant EGFR L858R (H1299L858R; gefitinib sensitive mutant. Results We predicted and experimentally verified that Mig6, which is a known negative regulator of EGFR and specifically expressed in H1299L858R cells, synergized with gefitinib to suppress cellular growth. Computational analyses indicated that this inhibitory effect is amplified at the phosphorylation/dephosphorylation steps of MEK and ERK. Conclusions Thus, we showed that L858R receptor mutation in combination with expression of its negative regulator, Mig6, alters signaling outcomes and results in variable drug sensitivity.

  3. Stage specific requirement of platelet-derived growth factor receptor-α in embryonic development.

    Science.gov (United States)

    Qian, Chen; Wong, Carol Wing Yan; Wu, Zhongluan; He, Qiuming; Xia, Huimin; Tam, Paul Kwong Hang; Wong, Kenneth Kak Yuen; Lui, Vincent Chi Hang

    2017-01-01

    Platelet-derived growth factor receptor alpha (PDGFRα) is a cell-surface receptor tyrosine kinase for platelet-derived growth factors. Correct timing and level of Pdgfra expression is crucial for embryo development, and deletion of Pdgfra caused developmental defects of multiple endoderm and mesoderm derived structures, resulting in a complex phenotypes including orofacial cleft, spina bifida, rib deformities, and omphalocele in mice. However, it is not clear if deletion of Pdgfra at different embryonic stages differentially affects these structures. To address the temporal requirement of Pdgfra in embryonic development. We have deleted the Pdgfra in Pdgfra-expressing tissues at different embryonic stages in mice, examined and quantified the developmental anomalies. Current study showed that (i) conditional deletion of Pdgfra at different embryonic days (between E7.5 and E10.5) resulted in orofacial cleft, spina bifida, rib cage deformities, and omphalocele, and (ii) the day of Pdgfra deletion influenced the combinations, incidence and severities of these anomalies. Deletion of Pdgfra caused apoptosis of Pdgfra-expressing tissues, and developmental defects of their derivatives. Orofacial cleft, spina bifida and omphalocele are among the commonest skeletal and abdominal wall defects of newborns, but their genetic etiologies are largely unknown. The remarkable resemblance of our conditional Pdgfra knockout embryos to theses human congenital anomalies, suggesting that dysregulated PDGFRA expression could cause these anomalies in human. Future work should aim at defining (a) the regulatory elements for the expression of the human PDGFRA during embryonic development, and (b) if mutations / sequence variations of these regulatory elements cause these anomalies.

  4. Estrogen Receptor β Agonists Differentially Affect the Growth of Human Melanoma Cell Lines.

    Directory of Open Access Journals (Sweden)

    Monica Marzagalli

    Full Text Available Cutaneous melanoma is an aggressive malignancy; its incidence is increasing worldwide and its prognosis remains poor. Clinical observations indicate that estrogen receptor β (ERβ is expressed in melanoma tissues and its expression decreases with tumor progression, suggesting its tumor suppressive function. These experiments were performed to investigate the effects of ERβ activation on melanoma cell growth.Protein expression was analyzed by Western blot and immunofluorescence assays. Cell proliferation was assessed by counting the cells by hemocytometer. ERβ transcriptional activity was evaluated by gene reporter assay. Global DNA methylation was analyzed by restriction enzyme assay and ERβ isoforms were identified by qRT-PCR. We demonstrated that ERβ is expressed in a panel of human melanoma cell lines (BLM, WM115, A375, WM1552. In BLM (NRAS-mutant cells, ERβ agonists significantly and specifically inhibited cell proliferation. ERβ activation triggered its cytoplasmic-to-nuclear translocation and transcriptional activity. Moreover, the antiproliferative activity of ERβ agonists was associated with an altered expression of G1-S transition-related proteins. In these cells, global DNA was found to be hypomethylated when compared to normal melanocytes; this DNA hypomethylation status was reverted by ERβ activation. ERβ agonists also decreased the proliferation of WM115 (BRAF V600D-mutant cells, while they failed to reduce the growth of A375 and WM1552 (BRAF V600E-mutant cells. Finally, we could observe that ERβ isoforms are expressed at different levels in the various cell lines. Specific oncogenic mutations or differential expression of receptor isoforms might be responsible for the different responses of cell lines to ERβ agonists.Our results demonstrate that ERβ is expressed in melanoma cell lines and that ERβ agonists differentially regulate the proliferation of these cells. These data confirm the notion that melanoma is a

  5. Effects of radiation on the epidermal growth factor receptor pathway in the heart.

    Science.gov (United States)

    Sridharan, Vijayalakshmi; Sharma, Sunil K; Moros, Eduardo G; Corry, Peter M; Tripathi, Preeti; Lieblong, Benjamin J; Guha, Chandan; Hauer-Jensen, Martin; Boerma, Marjan

    2013-07-01

    Radiation-induced heart disease (RIHD) is a serious side-effect of thoracic radiotherapy. The epidermal growth factor receptor (EGFR) pathway is essential for the function and survival of cardiomyocytes. Hence, agents that target the EGFR pathway are cardiotoxic. Tocotrienols protect from radiation injury, but may also enhance the therapeutic effects of EGFR pathway inhibitors in cancer treatment. This study investigated the effects of local irradiation on the EGFR pathway in the heart and tests whether tocotrienols may modify radiation-induced changes in this pathway. Male Sprague-Dawley rats received image-guided localized heart irradiation with 21 Gy. Twenty four hours before irradiation, rats received a single dose of tocotrienol-enriched formulation or vehicle by oral gavage. At time points from 2 h to 9 months after irradiation, left ventricular expression of EGFR pathway mediators was studied. Irradiation caused a decrease in the expression of epidermal growth factor (EGF) and neuregulin-1 (Nrg-1) mRNA from 6 h up to 10 weeks, followed by an upregulation of these ligands and the receptor erythroblastic leukemia viral oncogene homolog (ErbB)4 at 6 months. In addition, the upregulation of Nrg-1 was statistically significant up to 9 months after irradiation. A long-term upregulation of ErbB2 protein did not coincide with changes in transcription or post-translational interaction with the chaperone heat shock protein 90 (HSP90). Pretreatment with tocotrienols prevented radiation-induced changes at 2 weeks. Local heart irradiation causes long-term changes in the EGFR pathway. Studies have to address how radiation may interact with cardiotoxic effects of EGFR inhibitors.

  6. Quantitative super-resolution single molecule microscopy dataset of YFP-tagged growth factor receptors.

    Science.gov (United States)

    Lukeš, Tomáš; Pospíšil, Jakub; Fliegel, Karel; Lasser, Theo; Hagen, Guy M

    2018-01-19

    Super-resolution single molecule localization microscopy (SMLM) is a method for achieving resolution beyond the classical limit in optical microscopes (approx. 200 nm laterally). Yellow fluorescent protein (YFP) has been used for super-resolution single molecule localization microscopy, but less frequently than other fluorescent probes. Working with YFP in SMLM is a challenge because a lower number of photons are emitted per molecule compared to organic dyes which are more commonly used. Publically available experimental data can facilitate development of new data analysis algorithms. Four complete, freely available single molecule super-resolution microscopy datasets on YFP-tagged growth factor receptors expressed in a human cell line are presented including both raw and analyzed data. We report methods for sample preparation, for data acquisition, and for data analysis, as well as examples of the acquired images. We also analyzed the SMLM data sets using a different method: super-resolution optical fluctuation imaging (SOFI). The two modes of analysis offer complementary information about the sample. A fifth single molecule super-resolution microscopy dataset acquired with the dye Alexa 532 is included for comparison purposes. This dataset has potential for extensive reuse. Complete raw data from SMLM experiments has typically not been published. The YFP data exhibits low signal to noise ratios, making data analysis a challenge. These data sets will be useful to investigators developing their own algorithms for SMLM, SOFI, and related methods. The data will also be useful for researchers investigating growth factor receptors such as ErbB3. © The Author(s) 2018. Published by Oxford University Press.

  7. Insulin like growth factor 2 regulation of aryl hydrocarbon receptor in MCF-7 breast cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Tomblin, Justin K.; Salisbury, Travis B., E-mail: salisburyt@marshall.edu

    2014-01-17

    Highlights: •IGF-2 stimulates concurrent increases in AHR and CCND1 expression. •IGF-2 promotes the binding of AHR to the endogenous cyclin D1 promoter. •AHR knockdown inhibits IGF-2 stimulated increases in CCND1 mRNA and protein. •AHR knockdown inhibits IGF-2 stimulated increases in MCF-7 proliferation. -- Abstract: Insulin like growth factor (IGF)-1 and IGF-2 stimulate normal growth, development and breast cancer cell proliferation. Cyclin D1 (CCND1) promotes cell cycle by inhibiting retinoblastoma protein (RB1). The aryl hydrocarbon receptor (AHR) is a major xenobiotic receptor that also regulates cell cycle. The purpose of this study was to investigate whether IGF-2 promotes MCF-7 breast cancer proliferation by inducing AHR. Western blot and quantitative real time PCR (Q-PCR) analysis revealed that IGF-2 induced an approximately 2-fold increase (P < .001) in the expression of AHR and CCND1. Chromatin immunoprecipitation (ChIP), followed by Q-PCR indicated that IGF-2 promoted (P < .001) a 7-fold increase in AHR binding on the CCND1 promoter. AHR knockdown significantly (P < .001) inhibited IGF-2 stimulated increases in CCND1 mRNA and protein. AHR knockdown cells were less (P < .001) responsive to the proliferative effects of IGF-2 than control cells. Collectively, our findings have revealed a new regulatory mechanism by which IGF-2 induction of AHR promotes the expression of CCND1 and the proliferation of MCF-7 cells. This previously uncharacterized pathway could be important for the proliferation of IGF responsive cancer cells that also express AHR.

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

    Science.gov (United States)

    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

    2008-11-01

    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 (U87Delta) 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 U87Delta 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 U87Delta cells in addition to inhibiting cell proliferation, invasiveness, and colony formation in a significant manner (P < 0.05). Silencing EGFRvIII in U87Delta cultures with this virus reduced the expression of factors involved in epithelial-mesenchymal transition including N-cadherin, beta-catenin, Snail, Slug, and paxillin but not E-cadherin. The anti-EGFRvIII lentivirus also affected the cell cycle progression of U87Delta cells with a decrease in G(1) and increase in S and G(2) fractions. In an in vivo model, tumor growth was completely inhibited in severe combined immunodeficient mice (n = 10) injected s.c. with U87Delta 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.

  9. Signal interaction of Hedgehog/GLI and epidermal growth factor receptor signaling in cancer development

    International Nuclear Information System (INIS)

    Eberl, M.

    2012-01-01

    The subject of this PhD thesis is based on the cooperation of Hedgehog (HH)/GLI with epidermal growth factor receptor (EGFR) signaling synergistically promoting oncogenic transformation and cancer growth. In previous studies we have demonstrated that the HH/GLI and EGFR signaling pathways interact synergistically resulting not only in selective induction of HH/GLI-EGFR target genes, but also in the onset of oncogenic transformation and tumor formation (Kasper, Schnidar et al. 2006; Schnidar, Eberl et al. 2009). However, the molecular key mediators acting downstream of HH/GLI and EGFR signal cooperation were largely unknown and the in vivo evidence for the therapeutic relevance of HH/GLI and EGFR signal cooperation in HH-associated cancers was lacking. During my PhD thesis I could demonstrate that the integration of EGFR and HH/GLI signaling involves activation of RAS/MEK/ERK and JUN/AP1 signaling in response to EGFR activation. Furthermore I succeeded in identifying genes, including stem cell- (SOX2, SOX9), tumor growth- (JUN, TGFA, FGF19) and metastasis-associated genes (SPP1/osteopontin, CXCR4) that showed synergistic transcriptional activation by HH/GLI-EGFR signal integration. Importantly, I could demonstrate that these genes arrange themselves within a stable interdependent signaling network, which is required for in vivo growth of basal cell carcinoma (BCC) and tumor-initiating pancreatic cancer cells. These data validate EGFR signaling as additional drug target in HH/GLI driven cancers and provide new therapeutic strategies based on combined targeting of cooperative HH/GLI-EGFR signaling and selected downstream target genes (Eberl, Klingler et al. 2012). (author) [de

  10. Differential expression of the insulin-like growth factor receptor among early breast cancer subtypes.

    Directory of Open Access Journals (Sweden)

    Giannis Mountzios

    Full Text Available INTRODUCTION: We sought to determine the level of protein expression of the critical components of the insulin-like growth factor receptor (IGFR pathway and to evaluate their prognostic significance across the different early breast cancer subtypes. PATIENTS AND METHODS: Archival tumor tissue from 1,021 women with early, node positive breast cancer, who were prospectively evaluated within two randomized clinical trials, was used to construct tissue microarrays that were stained for hormone receptors (HR, Ki67, HER2, epidermal growth factor receptor (EGFR and cytokeratins 5/6, to classify tumors into five immunophenotypical subgroups. Immunohistochemical (IHC expression of IGF1R-alpha and beta subunits, IGF2R and IGF-binding protein 2 (IGFBP2 was assessed using the immunoreactive score (IRS. Repeated internal cross-validation was performed to examine the statistical validity of the cut off points for all biomarkers. RESULTS: After a median follow-up time of 105.4 months, overall 370 women (36.2% had relapsed and 270 (26.4% had died. Tumors expressing IGF1R-alpha above the median IRS were significantly more frequently HR positive (luminal A+B+HER2, as compared to HER2-enriched and triple negative ones (p<0.001 for both comparisons. IGF2R was overexpressed significantly more frequently in HR negative tumors (p = 0.001 and had an inverse correlation with all other biomarkers. Patients with luminal A and B tumors with high IGF1R-alpha and negative EGFR expression (N = 190 had significantly higher 4-year survival rates, as compared to the rest (log-rank p = 0.046, as did patients with luminal A and B tumors with high IGF1R-alpha and low IGF2R expression, as compared to the rest (N = 91, (log-rank p = 0.035. After adjustment for significant variables, patients in the latter group had a relative 45% reduction in the risk of death, as compared to the rest (p = 0.035. CONCLUSION: Aberrant expression of components of the IGF1R

  11. Epidermal growth factor treatment of A431 cells alters the binding capacity and electrophoretic mobility of the cytoskeletally associated epidermal growth factor receptor

    International Nuclear Information System (INIS)

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

    1991-01-01

    Epidermal growth factor receptor interacts with structural elements of A431 cells and remains associated with the cytoskeleton following extraction with nonionic detergents. Extraction of cells with 0.15% Triton X-100 resulted in detection of only approximately 40% of the EGF binding sites on the cytoskeleton. If the cells were exposed to EGF prior to extraction, approximately twofold higher levels of low-affinity EGF binding sites were detected. The difference in number of EGF binding sites was not a consequence of differences in numbers of EGF receptors associated with the cytoskeleton; equal amounts of 35S-labeled receptor were immunoprecipitated from the cytoskeletons of both control and EGF-treated cells. The effect of EGF pretreatment on binding activity was coincident with a change in the mobility of the receptor from a doublet of Mr approximately 160-180 kDa to a single sharp band at 180 kDa. The alteration in receptor mobility was not a simple consequence of receptor phosphorylation in that the alteration was not reversed by alkaline phosphatase treatment, nor was the shift produced by treatment of the cells with phorbol ester. The two EGF receptor species demonstrated differential susceptibility to V8 proteinase digestion. The EGF-induced 180 kDa species was preferentially digested by the proteinase relative to the 160 kDa species, indicating that EGF binding results in a conformational change in the receptor. The EGF-mediated preservation of binding activity and altered conformation may be related to receptor oligomerization

  12. Identification of tyrosine residues in the intracellular domain of the growth hormone receptor required for transcriptional signaling and Stat5 activation

    DEFF Research Database (Denmark)

    Hansen, L. H.; Wang, X.; Kopchick, J J

    1996-01-01

    The binding of growth hormone (GH) to its receptor results in its dimerization followed by activation of Jak2 kinase and tyrosine phosphorylation of the GH receptor itself, as well as Jak2 and the transcription factors Stat1, -3, and -5. In order to study the role of GH receptor tyrosine phosphor...

  13. Evidence for association of the cloned liver growth hormone receptor with a tyrosine kinase

    DEFF Research Database (Denmark)

    Wang, X; Uhler, M D; Billestrup, N

    1992-01-01

    at low levels in the COS-7 cells. To test whether a higher level of GH receptor phosphorylation would be observed when the GH receptor was expressed in a different cell line, GH receptor cDNAs were stably transfected into mouse L and CHO cells, which have few or no endogenous GH receptors, and RIN5-AH...... cells, which do express endogenous GH receptors. In vivo tyrosyl phosphorylation of the cloned GH receptor in mouse L cells and in vitro phosphorylation of the cloned GH receptor in both L and CHO cells were higher than in transfected COS-7 cells but still substantially lower than in untransfected 3T3-F...

  14. Intra-uterine Growth Restriction Downregulates the Hepatic Toll Like Receptor-4 Expression and Function

    Directory of Open Access Journals (Sweden)

    Ozlem Equils

    2005-01-01

    Full Text Available Maternal starvation is a significant cause of intrauterine growth restriction (IUGR in the world and increases the risk of infection in the neonate. We examined the effect of maternal starvation on Toll like receptor (TLR4 expression in hepatic, splenic and intestinal tissues obtained from the adult IUGR offspring of prenatal calorie restricted rats. The hepatic TLR4 protein concentration was undetectable in the IUGR rats that had restricted milk intake during the suckling period (SM/SP; n = 4, p < 0.05 as compared to the normal growth controls (CM/CP; n=4, and access to ad lib milk intake during the sucking period partially corrected the hepatic TLR4 expression (SM/CP; n = 4. IUGR had no effect on the splenic (n = 4 or intestinal (n = 4 TLR4 mRNA levels. In the liver, IUGR led to a 20% increase in baseline tumor necrosis factor (TNF-α mRNA expression ( p < 0.03 and a 70% increase in interleukin-1β (IL-1β mRNA expression ( p < 0.008 as compared to the control rats (CM/CP; n = 7. LPS-induced hepatic TNF-α release was significantly higher in SM/SP as compared to CM/CP. We propose that IUGR dysregulates TLR4 expression and function in the offspring, which may help explain the increased risk of Gram-negative sepsis and inflammatory diseases in this population.

  15. Systemic Hypoxia Changes the Organ-Specific Distribution of Vascular Endothelial Growth Factor and Its Receptors

    Science.gov (United States)

    Marti, Hugo H.; Risau, Werner

    1998-12-01

    Vascular endothelial growth factor (VEGF) plays a key role in physiological blood vessel formation and pathological angiogenesis such as tumor growth and ischemic diseases. Hypoxia is a potent inducer of VEGF in vitro. Here we demonstrate that VEGF is induced in vivo by exposing mice to systemic hypoxia. VEGF induction was highest in brain, but also occurred in kidney, testis, lung, heart, and liver. In situ hybridization analysis revealed that a distinct subset of cells within a given organ, such as glial cells and neurons in brain, tubular cells in kidney, and Sertoli cells in testis, responded to the hypoxic stimulus with an increase in VEGF expression. Surprisingly, however, other cells at sites of constitutive VEGF expression in normal adult tissues, such as epithelial cells in the choroid plexus and kidney glomeruli, decreased VEGF expression in response to the hypoxic stimulus. Furthermore, in addition to VEGF itself, expression of VEGF receptor-1 (VEGFR-1), but not VEGFR-2, was induced by hypoxia in endothelial cells of lung, heart, brain, kidney, and liver. VEGF itself was never found to be up-regulated in endothelial cells under hypoxic conditions, consistent with its paracrine action during normoxia. Our results show that the response to hypoxia in vivo is differentially regulated at the level of specific cell types or layers in certain organs. In these tissues, up- or down-regulation of VEGF and VEGFR-1 during hypoxia may influence their oxygenation after angiogenesis or modulate vascular permeability.

  16. IQGAP1 Protein Binds Human Epidermal Growth Factor Receptor 2 (HER2) and Modulates Trastuzumab Resistance*

    Science.gov (United States)

    White, Colin D.; Li, Zhigang; Dillon, Deborah A.; Sacks, David B.

    2011-01-01

    Human epidermal growth factor receptor 2 (HER2) is overexpressed in 20–25% of breast cancers. Increased HER2 expression is an adverse prognostic factor and correlates with decreased patient survival. HER2-positive (HER2(+)) breast cancer is treated with trastuzumab. Unfortunately, some patients are intrinsically refractory to therapy, and many who do respond initially become resistant within 1 year. Understanding the molecular mechanisms underlying HER2 signaling and trastuzumab resistance is essential to reduce breast cancer mortality. IQGAP1 is a ubiquitously expressed scaffold protein that contains multiple protein interaction domains. By regulating its binding partners IQGAP1 integrates signaling pathways, several of which contribute to breast tumorigenesis. We show here that IQGAP1 is overexpressed in HER2(+) breast cancer tissue and binds directly to HER2. Knockdown of IQGAP1 decreases HER2 expression, phosphorylation, signaling, and HER2-stimulated cell proliferation, effects that are all reversed by reconstituting cells with IQGAP1. Reducing IQGAP1 up-regulates p27, and blocking this increase attenuates the growth inhibitory effects of IQGAP1 knockdown. Importantly, IQGAP1 is overexpressed in trastuzumab-resistant breast epithelial cells, and reducing IQGAP1 both augments the inhibitory effects of trastuzumab and restores trastuzumab sensitivity to trastuzumab-resistant SkBR3 cells. These data suggest that inhibiting IQGAP1 function may represent a rational strategy for treating HER2(+) breast carcinoma. PMID:21724847

  17. The melatonin-MT1 receptor axis modulates tumor growth in PTEN-mutated gliomas.

    Science.gov (United States)

    Ma, Huihui; Wang, Zhen; Hu, Lei; Zhang, Shangrong; Zhao, Chenggang; Yang, Haoran; Wang, Hongzhi; Fang, Zhiyou; Wu, Lijun; Chen, Xueran

    2018-02-19

    More than 40% of glioma patients have tumors that harbor PTEN (phosphatase and tensin homologue deleted on chromosome ten) mutations; this disease is associated with poor therapeutic resistance and outcome. Such mutations are linked to increased cell survival and growth, decreased apoptosis, and drug resistance; thus, new therapeutic strategies focusing on inhibiting glioma tumorigenesis and progression are urgently needed. Melatonin, an indolamine produced and secreted predominantly by the pineal gland, mediates a variety of physiological functions and possesses antioxidant and antitumor properties. Here, we analyzed the relationship between PTEN and the inhibitory effect of melatonin in primary human glioma cells and cultured glioma cell lines. The results showed that melatonin can inhibit glioma cell growth both in culture and in vivo. This inhibition was associated with PTEN levels, which significantly correlated with the expression level of MT1 in patients. In fact, c-fos-mediated MT1 was shown to be a key modulator of the effect of melatonin on gliomas that harbor wild type PTEN. Taken together, these data suggest that melatonin-MT1 receptor complexes represent a potential target for the treatment of glioma. Copyright © 2018 Elsevier Inc. All rights reserved.

  18. Citrus pectin: characterization and inhibitory effect on fibroblast growth factor-receptor interaction.

    Science.gov (United States)

    Liu, Y; Ahmad, H; Luo, Y; Gardiner, D T; Gunasekera, R S; McKeehan, W L; Patil, B S

    2001-06-01

    This study was undertaken to characterize the pectin from four citrus species and to determine their in vitro inhibitory activities on the binding of fibroblast growth factor (FGF) to the FGF receptor (FGFR). Pectin from various parts of lemon, grapefruit, tangerine, and orange were isolated and characterized. Tangerine had the highest pectin content among the four citrus species. Segment membrane contained as much as or more pectin than flavedo/albedo. Anhydrogalacturonic content was highest in pectin from segment membrane of tangerine and flavedo/albedo of grapefruit. Lemon pectin contained the highest methoxyl content (MC), and grapefruit contained the largest proportion of lower molecular weight (lemon was the most potent inhibitor. The inhibition activity was significantly correlated with sugar content, MC, and size of pectin. Kinetic studies revealed a competitive nature of pectin inhibition with the heparin, a crucial component of the FGF signal transduction process. The observation that the heparin-dependent biological activity of FGF signal transduction is antagonized by citrus pectin should be further investigated for the use of these pectins as anti-growth factor agents for potential health benefits.

  19. Involvement of Fibroblast Growth Factor Receptor Genes in Benign Prostate Hyperplasia in a Korean Population

    Directory of Open Access Journals (Sweden)

    Hae Jeong Park

    2013-01-01

    Full Text Available Fibroblast growth factors (FGFs and their receptors (FGFRs have been implicated in prostate growth and are overexpressed in benign prostatic hyperplasia (BPH. In this study, we investigated whether single nucleotide polymorphisms (SNPs of the FGFR genes (FGFR1 and FGFR2 were associated with BPH and its clinical phenotypes in a population of Korean men. We genotyped four SNPs in the exons of FGFR1 and FGFR2 (rs13317 in FGFR1; rs755793, rs1047100, and rs3135831 in FGFR2 using direct sequencing in 218 BPH patients and 213 control subjects. No SNPs of FGFR1 or FGFR2 genes were associated with BPH. However, analysis according to clinical phenotypes showed that rs1047100 of FGFR2 was associated with prostate volume in BPH in the dominant model (GA/AA versus GG, P = 0.010. In addition, a significant association was observed between rs13317 of FGFR1 and international prostate symptom score (IPSS in the additive (TC versus CC versus TT, P = 0.0022 and dominant models (TC/CC versus TT, P = 0.005. Allele frequency analysis also showed significant association between rs13317 and IPSS (P = 0.005. These results suggested that FGFR genes could be related to progression of BPH.

  20. Growth suppression of Leydig TM3 cells mediated by aryl hydrocarbon receptor

    International Nuclear Information System (INIS)

    Iseki, Minoru; Ikuta, Togo; Kobayashi, Tetsuya; Kawajiri, Kaname

    2005-01-01

    Exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin induces developmental toxicity in reproductive organs. To elucidate the function of AhR, we generated stable transformants of TM3 cells overexpressing wild-type aryl hydrocarbon receptor (AhR) or its mutants which carried mutations in nuclear localization signal or nuclear export signal. In the presence of 3-methylcholanthrene (MC), proliferation of the cells transfected with wild-type AhR was completely suppressed, whereas cells expressing AhR mutants proliferated in a manner equivalent to control TM3 cells, suggesting AhR-dependent growth inhibition. The suppression was associated with up-regulation of cyclin-dependent kinase inhibitor p21 Cip1 , which was abolished by pretreatment with actinomycin D. A p38 MAPK specific inhibitor, SB203580, blocked the increase of p21 Cip1 mRNA in response to MC. Treatment with indigo, another AhR ligand, failed to increase of p21 Cip1 mRNA, although up-regulation of mRNA for CYP1A1 was observed. These data suggest AhR in Leydig cells mediates growth inhibition by inducing p21 Cip1

  1. Optical Molecular Imaging of Epidermal Growth Factor Receptor Expression to Improve Detection of Oral Neoplasia

    Directory of Open Access Journals (Sweden)

    Nitin Nitin

    2009-06-01

    Full Text Available Background: The development of noninvasive molecular imaging approaches has the potential to improve management of cancer. Methods: In this study, we demonstrate the potential of noninvasive topical delivery of an epidermal growth factor-Alexa 647 (EGF-Alexa 647 conjugate to image changes in epidermal growth factor receptor expression associated with oral neoplasia. We report a series of preclinical analyses to evaluate the optical contrast achieved after topical delivery of EGF-Alexa 647 in a variety of model systems, including cells, three-dimensional tissue cultures, and intact human tissue specimens using wide-field and high-resolution fluorescence imaging. Data were collected from 17 different oral cancer patients: eight pairs of normal and abnormal biopsies and nine resected tumors were examined. Results: The EGF-dye conjugate can be uniformly delivered throughout the oral epithelium with a penetration depth exceeding 500 µm and incubation time of less than 30 minutes. After EGF-Alexa 647 incubation, the presence of oral neoplasia is associated with a 1.5- to 6.9-fold increase in fluorescence contrast compared with grossly normal mucosa from the same patient with both wide-field and high-resolution fluorescence imaging. Conclusions: Results illustrate the potential of EGF-targeted fluorescent agents for in vivo molecular imaging, a technique that may aid in the diagnosis and characterization of oral neoplasia and allow real-time detection of tumor margins.

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

    DEFF Research Database (Denmark)

    Hougaard, S; Nørgaard, P; Abrahamsen, N

    1999-01-01

    Transforming growth factor beta (TGF-beta) exerts a growth inhibitory effect on many cell types through binding to two types of receptors, the type I and II receptors. Resistance to TGF-beta due to lack of type II receptor (RII) has been described in some cancer types including small cell lung...... cancer (SCLC). The purpose of this study was to examine the cause of absent RII expression in SCLC cell lines. Northern blot analysis showed that RII RNA expression was very weak in 16 of 21 cell lines. To investigate if the absence of RII transcript was due to mutations, we screened the poly-A tract...... for mutations, but no mutations were detected. Additional screening for mutations of the RII gene revealed a GG to TT base substitution in one cell line, which did not express RII. This mutation generates a stop codon resulting in predicted synthesis of a truncated RII of 219 amino acids. The nature...

  3. Neurite outgrowth induced by a synthetic peptide ligand of neural cell adhesion molecule requires fibroblast growth factor receptor activation

    DEFF Research Database (Denmark)

    Rønn, L C; Doherty, P; Holm, A

    2000-01-01

    The neural cell adhesion molecule NCAM is involved in axonal outgrowth and target recognition in the developing nervous system. In vitro, NCAM-NCAM binding has been shown to induce neurite outgrowth, presumably through an activation of fibroblast growth factor receptors (FGFRs). We have recently...

  4. Growth hormone preferentially induces the rapid, transient expression of SOCS-3, a novel inhibitor of cytokine receptor signaling

    DEFF Research Database (Denmark)

    Adams, T E; Hansen, J A; Starr, R

    1998-01-01

    Four members (SOCS-1, SOCS-2, SOCS-3, and CIS) of a family of cytokine-inducible, negative regulators of cytokine receptor signaling have recently been identified. To address whether any of these genes are induced in response to growth hormone (GH), serum-starved 3T3-F442A fibroblasts were incuba...

  5. MELATONIN-INDUCED SUPPRESSION OF PC12 CELL GROWTH IS MEDIATED BY ITS GI COUPLED TRANSMEMBRANE RECEPTORS. (R826248)

    Science.gov (United States)

    The effects of pertussis toxin, an uncoupler of Gi protein from adenylate cyclase, and luzindole, a competitive inhibitor of melatonin receptor binding, were examined for their ability to inhibit melatonin-induced suppression of PC12 cell growth. Both agents inhibited the mela...

  6. Resveratrol prevents angiotensin II-induced hypertrophy of vascular smooth muscle cells through the transactivation of growth factor receptors.

    Science.gov (United States)

    Hossain, Ekhtear; Anand-Srivastava, Madhu B

    2017-08-01

    We previously showed that augmented levels of endogenous angiotensin II (AngII) contribute to vascular smooth muscle cell (VSMC) hypertrophy through the transactivation of growth factor receptors in spontaneously hypertensive rats. Resveratrol (RV), a polyphenolic component of red wine, has also been shown to attenuate AngII-evoked VSMC hypertrophy; however, the molecular mechanism mediating this response is obscure. The present study was therefore undertaken to examine whether RV could prevent AngII-induced VSMC hypertrophy through the transactivation of growth factor receptor and associated signaling pathways. AngII treatment of VSMC enhanced the protein synthesis that was attenuated towards control levels by RV pretreatment as well as by the inhibitors of NADPH oxidase, c-Src, and growth factor receptors. Furthermore, RV pretreatment also inhibited enhanced levels of superoxide anion, NADPH oxidase activity, increased expression of NADPH oxidase subunits, and phosphorylation of c-Src, EGF-R, PDGE-R, ERK1/2, and AKT1/2. In conclusion, these results indicate that RV attenuates AngII-induced VSMC hypertrophy through the inhibition of enhanced oxidative stress and activation of c-Src, growth factor receptors, and MAPK/AKT signaling. We suggest that RV could be used as a therapeutic agent in the treatment of vascular complications associated with hypertension and hypertrophy.

  7. Elucidation of the mechanism of the regulatory function of the Ig1 module of the fibroblast growth factor receptor 1

    DEFF Research Database (Denmark)

    Kiselyov, Vladislav; Kochoyan, Artur; Poulsen, Flemming

    2006-01-01

    The extracellular part of the fibroblast growth factor (FGF) receptor (FGFR) consists of up to three Ig modules (Ig1-Ig3), in which the Ig2 and Ig3 modules determine affinity and specificity for FGF and heparin. The FGFR isoforms lacking the Ig1 module have higher affinity for FGF and heparin than...

  8. Plant lectin can target receptors containing sialic acid, exemplified by podoplanin, to inhibit transformed cell growth and migration.

    Directory of Open Access Journals (Sweden)

    Jhon Alberto Ochoa-Alvarez

    Full Text Available Cancer is a leading cause of death of men and women worldwide. Tumor cell motility contributes to metastatic invasion that causes the vast majority of cancer deaths. Extracellular receptors modified by α2,3-sialic acids that promote this motility can serve as ideal chemotherapeutic targets. For example, the extracellular domain of the mucin receptor podoplanin (PDPN is highly O-glycosylated with α2,3-sialic acid linked to galactose. PDPN is activated by endogenous ligands to induce tumor cell motility and metastasis. Dietary lectins that target proteins containing α2,3-sialic acid inhibit tumor cell growth. However, anti-cancer lectins that have been examined thus far target receptors that have not been identified. We report here that a lectin from the seeds of Maackia amurensis (MASL with affinity for O-linked carbohydrate chains containing sialic acid targets PDPN to inhibit transformed cell growth and motility at nanomolar concentrations. Interestingly, the biological activity of this lectin survives gastrointestinal proteolysis and enters the cardiovascular system to inhibit melanoma cell growth, migration, and tumorigenesis. These studies demonstrate how lectins may be used to help develop dietary agents that target specific receptors to combat malignant cell growth.

  9. Primary cilia and coordination of receptor tyrosine kinase (RTK) and transforming growth factor β (TGF-β) signaling

    DEFF Research Database (Denmark)

    Christensen, Søren Tvorup; Morthorst, Stine Kjær; Mogensen, Johanne Bay

    2017-01-01

    are at the root of a pleiotropic group of diseases and syndromic disorders called ciliopathies. In this review, we present an overview of primary cilia-mediated regulation of receptor tyrosine kinase (RTK) and transforming growth factor β (TGF-β) signaling. Further, we discuss how defects in the coordination...

  10. Molecular cloning and functional characterization of the human platelet-derived growth factor alpha receptor gene promoter

    NARCIS (Netherlands)

    Afink, G. B.; Nistér, M.; Stassen, B. H.; Joosten, P. H.; Rademakers, P. J.; Bongcam-Rudloff, E.; van Zoelen, E. J.; Mosselman, S.

    1995-01-01

    Expression of the platelet-derived growth factor alpha receptor (PDGF alpha R) is strictly regulated during mammalian development and tumorigenesis. The molecular mechanisms involved in the specific regulation of PDGF alpha R expression are unknown, but transcriptional regulation of the PDGF alpha R

  11. Magnesium wasting associated with epidermal-growth-factor receptor-targeting antibodies in colorectal cancer: a prospective study.

    NARCIS (Netherlands)

    Tejpar, S.; Piessevaux, H.; Claes, K.; Piront, P.; Hoenderop, J.G.J.; Verslype, C.; Cutsem, E. van

    2007-01-01

    BACKGROUND: Preliminary evidence suggests that magnesium wasting occurs in patients who are treated with epidermal-growth-factor receptor (EGFR)-targeting antibodies for colorectal cancer. The mechanism of this side-effect is unknown, and if all or a subset of patients are affected is also unclear.

  12. Intraoperative fluorescence delineation of head and neck cancer with a fluorescent Anti-epidermal growth factor receptor nanobody

    NARCIS (Netherlands)

    Van Driel, P.B.A.A.; Van Der Vorst, J.R.; Verbeek, F.P.R.; Oliveira, S.|info:eu-repo/dai/nl/304841455; Snoeks, T.J.A.; Keereweer, S.; Chan, B.; Boonstra, M.C.; Frangioni, J.V.; Van Bergen En Henegouwen, P.M.P.|info:eu-repo/dai/nl/071919481; Vahrmeijer, A.L.; Lowik, C.W.G.M.

    2014-01-01

    Intraoperative near-infrared (NIR) fluorescence imaging is a technology with high potential to provide the surgeon with real-time visualization of tumors during surgery. Our study explores the feasibility for clinical translation of an epidermal growth factor receptor (EGFR)-targeting nanobody for

  13. Limited human epidermal growth factor receptor 2 discordance in metastatic breast cancer patients treated with trastuzumab, a population based study

    NARCIS (Netherlands)

    van Rooijen, J.M.; de Munck, L.; de Graaf, J.C.; Siesling, Sabine; de Vries, Erik G.; Boers, J.E.

    2014-01-01

    Background Accurate assessment of the human epidermal growth factor receptor 2 (HER2) in breast cancer is essential for proper treatment decisions. HER2 positivity confirmation rates in breast cancer trials by central testing pathology laboratories were reported to be approximately 85%. The aim of

  14. Limited human epidermal growth factor receptor 2 discordance in metastatic breast cancer patients treated with trastuzumab, a population based study

    NARCIS (Netherlands)

    van Rooijen, J. M.; de Munck, L.; de Graaf, J. C.; Siesling, S.; de Vries, E. G.; Boers, J. E.

    Background: Accurate assessment of the human epidermal growth factor receptor 2 (HER2) in breast cancer is essential for proper treatment decisions. HER2 positivity confirmation rates in breast cancer trials by central testing pathology laboratories were reported to be approximately 85%. The aim of

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

    DEFF Research Database (Denmark)

    Green, M R; Couchman, J R

    1985-01-01

    Two methods have been used to examine epidermal growth factor (EGF) receptor distribution in human scalp and foreskin. The first employed [125I]EGF viable explants and autoradiography to determine the EGF binding pattern while the second used a monoclonal antibody to the human EGF receptor to map...... the distribution on frozen skin sections of an extracellular epitope on the EGF receptor. The [125I]EGF binding experiments showed accessible, unoccupied EGF receptors to be present on the epidermal basal cells (with reduced binding to spinous cells), the basal cells of the hair shaft and sebaceous gland......, the eccrine sweat glands, capillary system, and the hair follicle outer root sheath, generally similar in pattern to that previously reported for full-thickness rat skin and human epidermis. The same areas also bound EGF-R1 but in addition the monoclonal antibody recognized a cone of melanin containing...

  16. Structure and function of the Juxta membrane domain of the human epidermal growth factor receptor by NMR spectroscopy

    International Nuclear Information System (INIS)

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

    2005-10-01

    The epidermal growth factor receptor (EGFR) is a member of the receptor tyrosine kinase family involved in the regulation of cellular proliferation and differentiation. Its juxta membrane domain (JX), the region located between the transmembrane and kinase domains, plays important roles in receptor trafficking since both basolateral sorting in polarized epithelial cells and lysosomal sorting signals are identified in this region. In order to understand the regulation of these signals, we characterized the structural properties of recombinant JX domain in dodecyl phosphocholine detergent (DPC) by nuclear magnetic resonance (NMR) spectroscopy. In DPC micelles, structures derived from NMR data showed three amphipathic, helical segments. Two equivalent average structural models on the surface of micelles were obtained that differ only in the relative orientation between the first and second helices. Our data suggests that the activity of sorting signals may be regulated by their membrane association and restricted accessibility in the intact receptor

  17. Thyroid hormone receptor binds to a site in the rat growth hormone promoter required for induction by thyroid hormone

    International Nuclear Information System (INIS)

    Koenig, R.J.; Brent, G.A.; Warne, R.L.; Larsen, P.R.; Moore, D.D.

    1987-01-01

    Transcription of the rat growth hormone (rGH) gene in pituitary cells is increased by addition of thyroid hormone (T3). This induction is dependent on the presence of specific sequences just upstream of the rGH promoter. The authors have partially purified T3 receptor from rat liver and examined its interaction with these rGH sequences. They show here that T3 receptor binds specifically to a site just upstream of the basal rGH promoter. This binding site includes two copies of a 7-base-pair direct repeat, the centers of which are separated by 10 base pairs. Deletions that specifically remove the T3 receptor binding site drastically reduce response to T3 in transient transfection experiments. These results demonstrate that T3 receptor can recognize specific DNA sequences and suggest that it can act directly as a positive transcriptional regulatory factor

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

    LENUS (Irish Health Repository)

    Wakai, A

    2012-02-03

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

  19. Exon 3-deleted and full-length growth hormone receptor polymorphism frequencies in an Iranian population.

    Science.gov (United States)

    Palizban, A A; Radmansorry, M; Bozorgzad, M

    2014-01-01

    The functional role of the exon 3 growth hormone receptor (d3GHR) polymorphism in human and its distributions in different populations is not clearly understood. The presence of full length growth hormone (flGHR) is the most important in metabolic risk factors. The aim of this study was to define the frequency distribution of d3GHR/full-length GHR in an Iranian population. The presence of the d3GHR polymorphism in healthy volunteers blood DNA (n=80, male=30 and female=50) was assessed by PCR using specific primers. The 935-bp and 592-bp fragments indicate the presence of the flGHR and the exon3 deletion of GHR, respectively. The distribution of the GHR genotypes in this study were 31.4% (n=24) for fl/flGHR, 49.7 % (n=41) for fl/d3GHR, and 19.0 % (n=15) for d3/d3GHR. Frequencies of fl allele and d3 allele were 55.4% and 44.4% within whole population, respectively. There was no difference in allels frequencies of GHR in male (fl=0.583, d3=0.417) and female (fl=0.540, d3=0.460) when compared with whole population. The results showed that the frequency of d3/d3GHR isoform was significantly lower than that of the fl/flGHR and d3/flGHR. The frequencies of GHR polymorphisms were likely consistent with previous reports. Our finding is also consistant with Mexican population. The advantage of existence of the d3/d3 rather than fl/flGHR polymorphisms in individuals and in correlation with diseases opens new insights for GH and insilin-like-growth factor-1 (IGF-I) axis.

  20. Estrogenic compounds decrease growth hormone receptor abundance and alter osmoregulation in Atlantic salmon

    Science.gov (United States)

    Lerner, Darren T.; Sheridan, Mark A.; McCormick, Stephen D.

    2012-01-01

    Exposure of Atlantic salmon smolts to estrogenic compounds is shown to compromise several aspects of smolt development. We sought to determine the underlying endocrine mechanisms of estrogen impacts on the growth hormone (GH)/insulin-like growth factor I (IGF-I) axis. Smolts in freshwater (FW) were either injected 3 times over 10 days with 2 μg g−1 17β-estradiol (E2) or 150 μg g−1 4-nonylphenol (NP). Seawater (SW)-acclimated fish received intraperitoneal implants of 30 μg g−1 E2 over two weeks. Treatment with these estrogenic compounds increased hepatosomatic index and total plasma calcium. E2 and NP reduced maximum growth hormone binding by 30–60% in hepatic and branchial membranes in FW and SW, but did not alter the dissociation constant. E2 and NP treatment decreased plasma levels of IGF-I levels in both FW and SW. In FW E2 and NP decreased plasma GH whereas in SW plasma GH increased after E2 treatment. Compared to controls, plasma chloride concentrations of E2-treated fish were decreased 5.5 mM in FW and increased 10.5 mM in SW. There was no effect of NP or E2 on gill sodium–potassium adenosine triphosphatase (Na+/K+-ATPase) activity in FW smolts, whereas E2 treatment in SW reduced gill Na+/K+-ATPase activity and altered the number and size of ionocytes. Our data indicate that E2 downregulates the GH/IGF-I-axis and SW tolerance which may be part of its normal function for reproduction and movement into FW. We conclude that the mechanism of endocrine disruption of smolt development by NP is in part through alteration of the GH/IGF-I axis via reduced GH receptor abundance.

  1. Norgestrel and gestodene stimulate breast cancer cell growth through an oestrogen receptor mediated mechanism.

    Science.gov (United States)

    Catherino, W. H.; Jeng, M. H.; Jordan, V. C.

    1993-01-01

    There is great concern over the long-term influence of oral contraceptives on the development of breast cancer in women. Oestrogens are known to stimulate the growth of human breast cancer cells, and this laboratory has previously reported (Jeng & Jordan, 1991) that the 19-norprogestin norethindrone could stimulate the proliferation of MCF-7 human breast cancer cells. We studied the influence of the 19-norprogestins norgestrel and gestodene compared to a 'non' 19-norprogestin medroxyprogesterone acetate (MPA) on MCF-7 cell proliferation. The 19-norprogestins stimulated proliferation at a concentration of 10(-8) M, while MPA could not stimulate proliferation at concentrations as great as 3 x 10(-6) M. The stimulatory activity of the 19-norprogestins could be blocked by the antioestrogen ICI 164,384, but not by the antiprogestin RU486. Transfection studies with the reporter plasmids containing an oestrogen response element or progesterone response element (vitERE-CAT, pS2ERE-CAT, and PRE15-CAT) were performed to determine the intracellular action of norgestrel and gestodene. The 19-norprogestins stimulated the vitERE-CAT activity maximally at 10(-6) M, and this stimulation was inhibited by the addition of ICI 164,384. MPA did not stimulate vitERE-CAT activity. A single base pair alteration in the palindromic sequence of vitERE (resulting in the pS2ERE) led to a dramatic decrease in CAT expression by the 19-norprogestins, suggesting that the progestin activity required specific response element base sequencing. PRE15-CAT activity was stimulated by norgestrel, gestodene and MPA at concentrations well below growth stimulatory activity. This stimulation could be blocked by RU486. These studies suggest that the 19-norprogestins norgestrel and gestodene stimulate MCF-7 breast cancer cell growth by activating the oestrogen receptor. PMID:8494728

  2. Estrogen receptor β ligation inhibits Hodgkin lymphoma growth by inducing autophagy

    Science.gov (United States)

    Locatelli, Silvia L.; Ciarlo, Laura; Careddu, Giuseppa; Patrizio, Mario; Ascione, Barbara; Tinari, Antonella; Carlo-Stella, Carmelo; Malorni, Walter; Matarrese, Paola; Ortona, Elena

    2017-01-01

    Although Hodgkin lymphoma (HL) is curable with current therapy, at least 20% of patients relapse or fail to make complete remission. In addition, patients who achieve long-term disease-free survival frequently undergo infertility, secondary malignancies, and cardiac failure, which are related to chemotherapeutic agents and radiation therapies. Hence, new therapeutic strategies able to counteract the HL disease in this important patient population are still a matter of study. Estrogens, in particular 17β-estradiol (E2), have been suggested to play a role in lymphoma cell homeostasis by estrogen receptors (ER) β activation. On these bases, we investigated whether the ligation of ERβ by a selective agonist, the 2,3-bis(4-hydroxyphenyl)-propionitrile (DPN), could impact HL tumor growth. We found that DPN-mediated ERβ activation led to a reduction of in vitro cell proliferation and cell cycle progression by inducing autophagy. In nonobese diabetic/severe combined immunodeficient (NOD/SCID) mice engrafted with HL cells, ERβ activation by DPN was able to reduce lymphoma growth up to 60% and this associated with the induction of tumor cell autophagy. Molecular characterization of ERβ-induced autophagy revealed an overexpression of damage-regulated autophagy modulator 2 (DRAM2) molecule, whose role in autophagy modulation is still debated. After ERβ activation, both DRAM2 and protein 1 light chain 3 (LC3), a key actor in the autophagosome formation, strictly interacted each other and localized at mitochondrial level. Altogether these results suggest that targeting ERβ with selective agonists might affect HL cell proliferation and tumor growth via a mechanism that brings into play DRAM2-dependent autophagic cascade. PMID:28052027

  3. Growth hormone-dependent phosphorylation of tyrosine 333 and/or 338 of the growth hormone receptor

    DEFF Research Database (Denmark)

    VanderKuur, J A; Wang, X; Zhang, L

    1995-01-01

    and a reduction of GH-dependent phosphorylation of the full-length receptor. Consistent with Tyr333 and/or Tyr338 serving as substrates of JAK2, these substitutions resulted in a loss of tyrosyl phosphorylation of truncated receptor in an in vitro kinase assay using substantially purified GH.GHR.JAK2 complexes...

  4. Growth hormone receptor (GHR) gene polymorphism and scoliosis in Prader-Willi syndrome.

    Science.gov (United States)

    Butler, Merlin G; Hossain, Waheeda; Hassan, Maaz; Manzardo, Ann M

    2018-04-01

    A growth hormone receptor (GHR) gene polymorphism impacts sensitivity to endogenous and exogenous growth hormone (GH) to moderate growth and development. Increased sensitivity may accelerate spinal growth and contribute to scoliosis, particularly in GH-deficient and treated populations such as Prader-Willi syndrome (PWS). Therefore, we examined the relationship between GHR genotype and scoliosis (case and control) in PWS cohorts. We utilized a case-control design in a study of 73 subjects (34M; 39F) with genetically confirmed PWS in 32 individuals previously diagnosed with moderate to severe scoliosis (mean age=16.9±10.2years; age range of 1 to 41years) and 41 adults with no evidence of scoliosis (mean age=30.8±9.7years; age range of 18 to 56years). The GHR gene polymorphism was determined using PCR specific primers to capture the two recognized GHR gene fragment sizes [i.e., full length (fl) or exon 3 deletions (d3)]. Twenty-three (72%) of the 32 case subjects with scoliosis required surgical correction with an approximately equal balance for gender and PWS genetic subtype among cases and 41 control subjects without scoliosis. The GHR d3/d3 genotype was identified in N=2 of 8 (25%) cases with scoliosis and the d3/fl genotype was identified in N=11 of 25 (44%) cases with scoliosis but the distribution difference did not statistically differ. The GHR fl/fl genotype was correlated with a significantly faster rate and heavier weight gain among case subjects. Our examination of demographic and genetic markers associated with scoliosis and surgical repair in PWS found no evidence to support differences in gender, PWS genetic subtype or GHR d3 allele distributions among the case vs control groups. Those with fl/fl alleles were heavier than those with d3/d3 or d3/fl genotypes and warrant further study with a larger sample size and possibly to include other vulnerable populations requiring growth hormone treatment. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Effect of angiotensin II type 1 receptor blocker and angiotensin converting enzyme inhibitor on the intraocular growth factors and their receptors in streptozotocin-induced diabetic rats

    Directory of Open Access Journals (Sweden)

    Ik Soo Byon

    2017-06-01

    Full Text Available AIM: To investigate the effect of angiotensin II type 1 receptor blocker (ARB and angiotensin converting enzyme inhibitor (ACEI on intraocular growth factors and their receptors in streptozotocin-induced diabetic rats. METHODS: Forty Sprague-Dawley rats were divided into 4 groups: control, diabetes mellitus (DM, candesartan-treated DM, and enalapril-treated DM (each group, n=10. After the induction of DM by streptozotocin, candesartan [ARB, 5 mg/(kg·d] and enalapril [ACEI, 10 mg/(kg·d] were administered to rats orally for 4wk. Vascular endothelial growth factor (VEGF and angiotensin II (Ang II concentrations in the vitreous were measured using enzyme-linked immunosorbent assays, and VEGF receptor 2 and angiotensin II type 1 receptor (AT1R levels were assessed at week 4 by Western blotting. RESULTS: Vitreous Ang II levels were significantly higher in the DM group and candesartan-treated DM group than in the control (P=0.04 and 0.005, respectively. Vitreous AT1R increased significantly in DM compared to the other three groups (P<0.007. Candesartan-treated DM rats showed higher vitreal AT1R concentration than the enalapril-treated DM group and control (P<0.001 and P=0.005, respectively. No difference in vitreous Ang II and AT1R concentration was found between the enalapril-treated DM group and control. VEGF and its receptor were below the minimum detection limit in all 4 groups. CONCLUSION: Increased Ang II and AT1R in the hyperglycemic state indicate activated the intraocular renin-angiotensin system, which is inhibited more effectively by systemic ACEI than systemic ARB.

  6. Role of Epidermal Growth Factor Receptors and Their Ligands in Normal Mammary Epithelial and Breast Cancer Cells

    Science.gov (United States)

    1997-07-01

    Birkedal-Hansen H 1993 Interleukin-1 3 and transforming growth factor-u,/epidermal growth factor induce expression of 56 Darcy, Kathleen M. Mr 95,000...Ellis I 0, Blamey R W 1994 Epidermal growth factor receptor expression in breast cancer: association with response to endocrine therapy. Breast Cancer...Distribution Statement 2. Point of contact for this request is Ms. Judy Pawlus at DSN 343-7322 or email: judy pawlus@ftdetrck-ccmail.army.mil. FOR THE COMMANDER: PHYLTS AM.RINEHART Deputy Chief of Staff for Information Management

  7. Retinal hypoxia induces vascular endothelial growth factor through induction of estrogen-related receptor γ

    Energy Technology Data Exchange (ETDEWEB)

    Do, Ji Yeon; Choi, Young Keun [Leading-edge Research Center for Drug Discovery and Development for Diabetes and Metabolic Disease, Kyungpook National University School of Medicine, Kyungpook National University, Daegu (Korea, Republic of); Kook, Hyun [Department of Pharmacology, Chonnam National University Medical School, Gwangju (Korea, Republic of); Suk, Kyoungho [Department of Pharmacology, Brain Science & Engineering Institute, Kyungpook National University School of Medicine, Daegu (Korea, Republic of); Lee, In-Kyu [Leading-edge Research Center for Drug Discovery and Development for Diabetes and Metabolic Disease, Kyungpook National University School of Medicine, Kyungpook National University, Daegu (Korea, Republic of); Division of Endocrinology and Metabolism, Department of Internal Medicine, Research Institute of Aging and Metabolism, Kyungpook National University School of Medicine, Daegu (Korea, Republic of); Park, Dong Ho, E-mail: sarasate2222@gmail.com [Department of Ophthalmology, Kyungpook National University School of Medicine, Daegu (Korea, Republic of)

    2015-05-01

    Ischemic retinopathies causing overexpression of pro-angiogenic factors, including vascular endothelial growth factor (VEGF), are the most common cause of blindness. Thus, understanding the pathophysiology of targetable pathways that regulate retinal VEGF is of great interest. A conserved binding site for estrogen-related receptor γ (ERRγ) has been identified in the promoter of the Vegfa gene. ERRγ is a constitutively active orphan nuclear receptor and its expression is increased by hypoxic stimuli in metabolically active tissues. This study evaluated the role of ERRγ in the ischemic retina and the anti-VEGF potential of GSK5182, a selective inverse agonist of ERRγ. In an oxygen-induced retinopathy (OIR) mouse model, immunohistochemistry showed significantly increased ERRγ expression in the ganglion cell layer at postnatal day (P) 17. In a ganglion cell line (RGC-5), mRNA and protein levels of ERRγ were increased by desferrioxamine treatment and hypoxic conditions (1% O{sub 2}). Transient transfection of RGC-5 cells revealed that ERRγ regulated Vegfa expression and this was inhibited by GSK5182. Intravitreal injection of GSK5182 into the OIR model at P14 inhibited retinal Vegfa mRNA expression at P17. GSK5182 suppresses hypoxia-induced VEGF expression via ERRγ; therefore, ERRγ could be a treatment target for ischemic retinopathies. - Highlights: • OIR mice exhibited increased ERRγ expression in the ganglion cell layer. • Hypoxia-induced ERRγ expression was observed in retinal ganglion cells. • ERRγ overexpression increased VEGFA expression in retinal ganglion cells. • An ERRγ inverse agonist suppressed VEGFA expression in retinal ganglion cells. • Intravitreal injection of an ERRγ inverse agonist suppressed VEGFA in OIR mice.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-09-09

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

  9. Vascular endothelial growth factor receptor-3 directly interacts with phosphatidylinositol 3-kinase to regulate lymphangiogenesis.

    Directory of Open Access Journals (Sweden)

    Sanja Coso

    Full Text Available BACKGROUND: Dysfunctional lymphatic vessel formation has been implicated in a number of pathological conditions including cancer metastasis, lymphedema, and impaired wound healing. The vascular endothelial growth factor (VEGF family is a major regulator of lymphatic endothelial cell (LEC function and lymphangiogenesis. Indeed, dissemination of malignant cells into the regional lymph nodes, a common occurrence in many cancers, is stimulated by VEGF family members. This effect is generally considered to be mediated via VEGFR-2 and VEGFR-3. However, the role of specific receptors and their downstream signaling pathways is not well understood. METHODS AND RESULTS: Here we delineate the VEGF-C/VEGF receptor (VEGFR-3 signaling pathway in LECs and show that VEGF-C induces activation of PI3K/Akt and MEK/Erk. Furthermore, activation of PI3K/Akt by VEGF-C/VEGFR-3 resulted in phosphorylation of P70S6K, eNOS, PLCγ1, and Erk1/2. Importantly, a direct interaction between PI3K and VEGFR-3 in LECs was demonstrated both in vitro and in clinical cancer specimens. This interaction was strongly associated with the presence of lymph node metastases in primary small cell carcinoma of the lung in clinical specimens. Blocking PI3K activity abolished VEGF-C-stimulated LEC tube formation and migration. CONCLUSIONS: Our findings demonstrate that specific VEGFR-3 signaling pathways are activated in LECs by VEGF-C. The importance of PI3K in VEGF-C/VEGFR-3-mediated lymphangiogenesis provides a potential therapeutic target for the inhibition of lymphatic metastasis.

  10. Characterization of pituitary growth hormone and its receptor in the green iguana (Iguana iguana).

    Science.gov (United States)

    Ávila-Mendoza, José; Carranza, Martha; Pérez-Rueda, Ernesto; Luna, Maricela; Arámburo, Carlos

    2014-07-01

    Pituitary growth hormone (GH) has been studied in most vertebrate groups; however, only a few studies have been carried out in reptiles. Little is known about pituitary hormones in the order Squamata, to which the green iguana (gi) belongs. In this work, we characterized the hypophysis of Iguana iguana morphologically. The somatotrophs (round cells of 7.6-10 μm containing 250- to 300-nm secretory granules where the giGH is stored) were found, by immunohistochemistry and in situ hybridization, exclusively in the caudal lobe of the pars distalis, whereas the lactotrophs were distributed only in the rostral lobe. A pituitary giGH-like protein was obtained by immuno-affinity chromatography employing a heterologous antibody against chicken GH. giGH showed molecular heterogeneity (22, 44, and 88 kDa by SDS-PAGE/Western blot under non-reducing conditions and at least four charge variants (pIs 6.2, 6.5, 6.9, 7.4) by isoelectric focusing. The pituitary giGH cDNA (1016 bp), amplified by PCR and RACE, encodes a pre-hormone of 218 aa, of which 190 aa correspond to the mature protein and 28 aa to the signal peptide. The giGH receptor cDNA was also partially sequenced. Phylogenetic analyses of the amino acid sequences of giGH and giGHR homologs in vertebrates suggest a parallel evolution and functional relationship between the GH and its receptor. Copyright © 2014 Elsevier Inc. All rights reserved.

  11. Molecular basis for the Kallmann syndrome-linked fibroblast growth factor receptor mutation

    Energy Technology Data Exchange (ETDEWEB)

    Thurman, Ryan D.; Kathir, Karuppanan Muthusamy; Rajalingam, Dakshinamurthy [Department of Chemistry and Biochemistry, University of Arkansas, Fayetteville, AR 72701 (United States); Kumar, Thallapuranam K. Suresh, E-mail: sthalla@uark.edu [Department of Chemistry and Biochemistry, University of Arkansas, Fayetteville, AR 72701 (United States)

    2012-08-31

    Highlights: Black-Right-Pointing-Pointer The structural basis of the Kallmann syndrome is elucidated. Black-Right-Pointing-Pointer Kallmann syndrome mutation (A168S) induces a subtle conformational change(s). Black-Right-Pointing-Pointer Structural interactions mediated by beta-sheet G are most perturbed. Black-Right-Pointing-Pointer Ligand (FGF)-receptor interaction(s) is completely abolished by Kallmann mutation. Black-Right-Pointing-Pointer Kallmann mutation directly affects the FGF signaling process. -- Abstract: Kallmann syndrome (KS) is a developmental disease that expresses in patients as hypogonadotropic hypogonadism and anosmia. KS is commonly associated with mutations in the extracellular D2 domain of the fibroblast growth factor receptor (FGFR). In this study, for the first time, the molecular basis for the FGFR associated KS mutation (A168S) is elucidated using a variety of biophysical experiments, including multidimensional NMR spectroscopy. Secondary and tertiary structural analysis using far UV circular dichroism, fluorescence and limited trypsin digestion assays suggest that the KS mutation induces subtle tertiary structure change in the D2 domain of FGFR. Results of isothermal titration calorimetry experiments show the KS mutation causes a 10-fold decrease in heparin binding affinity and also a complete loss in ligand (FGF-1) binding. {sup 1}H-{sup 15}N chemical perturbation data suggest that complete loss in the ligand (FGF) binding affinity is triggered by a subtle conformational change that disrupts crucial structural interactions in both the heparin and the FGF binding sites in the D2 domain of FGFR. The novel findings reported in this study are expected to provide valuable clues toward a complete understanding of the other genetic diseases linked to mutations in the FGFR.

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

    International Nuclear Information System (INIS)

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

    2016-01-01

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

  13. The role of epidermal growth factor receptor in chordoma pathogenesis: a potential therapeutic target.

    Science.gov (United States)

    Shalaby, Asem; Presneau, Nadège; Ye, Hongtao; Halai, Dina; Berisha, Fitim; Idowu, Bernadine; Leithner, Andreas; Liegl, Bernadette; Briggs, Timothy R W; Bacsi, Krisztian; Kindblom, Lars-Gunnar; Athanasou, Nicholas; Amary, Maria Fernanda; Hogendoorn, Pancras C W; Tirabosco, Roberto; Flanagan, Adrienne M

    2011-02-01

    Chordoma, the molecular hallmark of which is T (brachyury), is a rare malignant bone tumour with a high risk of local recurrence and a tumour from which metastatic disease is a common late event. Currently, there is no effective drug therapy for treating chordomas, although there is evidence that some patients respond to the empirical use of epidermal growth factor receptor (EGFR) antagonists. The aim of this study was to determine the role of EGFR in the pathogenesis of chordoma. Paraffin-embedded material from 173 chordomas from 160 patients [sacro-coccygeal (n = 94), skull-based (n = 50), and mobile spine (n = 16)] was analysed by immunohistochemistry and revealed total EGFR expression in 69% of cases analysed. Of 147 informative chordomas analysed by FISH, 38% revealed high-level EGFR polysomy, 4% high-level polysomy with focal amplification, 18% low-level polysomy, and 39% disomy. Phospho-receptor tyrosine kinase array membranes showed EGFR activation in the chordoma cell line U-CH1 and all of the three chordomas analysed. Direct sequencing of EGFR (exons 18-21), KRAS, NRAS, HRAS (exons 2, 3), and BRAF (exons 11, 15) using DNA from 62 chordomas failed to reveal mutations. PTEN expression was absent by immunohistochemistry in 19 of 147 (13%) analysed chordomas, only one of which revealed high-level polysomy of EGFR. The EGFR inhibitor tyrphostin (AG 1478) markedly inhibited proliferation of the chordoma cell line U-CH1 in vitro and diminished EGFR phosphorylation in a dose-dependant manner, a finding supported by inhibition of phosphorylated Erk1/2. p-Akt was suppressed to a much lesser degree in these experiments. There was no reduction of T as assessed by western blotting. These data implicate aberrant EGFR signalling in the pathogenesis of chordoma. This study provides a strategy for patient stratification for treatment with EGFR antagonists. Copyright © 2010 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

  14. Normal epidermal growth factor receptor signaling is dispensable for bone anabolic effects of parathyroid hormone.

    Science.gov (United States)

    Schneider, Marlon R; Dahlhoff, Maik; Andrukhova, Olena; Grill, Jessica; Glösmann, Martin; Schüler, Christiane; Weber, Karin; Wolf, Eckhard; Erben, Reinhold G

    2012-01-01

    Although the bone anabolic properties of intermittent parathyroid hormone (PTH) have long been employed in the treatment of osteoporosis, the molecular mechanisms behind this action remain largely unknown. Previous studies showed that PTH increases the expression and the activity of epidermal growth factor receptor (EGFR) in osteoblasts, and activation of ERK1/2 by PTH in osteoblasts was demonstrated to induce the proteolytical release of EGFR ligands and EGFR transactivation. However, conclusive evidence for an important role of the EGFR system in mediating the anabolic actions of intermittent PTH on bone in vivo is lacking. Here, we evaluated the effects of intermittent PTH on bone in Waved-5 (Wa5) mice which carry an antimorphic Egfr allele whose product acts as a dominant negative receptor. Heterozygous Wa5 females and control littermates received a subcutaneous injection of PTH (80 μg/kg) or buffer on 5 days per week for 4 weeks. Wa5 mice had slightly lower total bone mineral density (BMD), but normal cancellous bone volume and turnover in the distal femoral metaphysis. The presence of the antimorphic Egfr allele neither influenced the PTH-induced increase in serum osteocalcin nor the increases in distal femoral BMD, cortical thickness, cancellous bone volume, and cancellous bone formation rate. Similarly, the PTH-induced rise in lumbar vertebral BMD was unchanged in Wa5 relative to wild-type mice. Wa5-derived osteoblasts showed considerably lower basal extracellular signal-regulated kinase 1/2 (ERK1/2) activation as compared to control osteoblasts. Whereas activation of ERK1/2 by the EGFR ligand amphiregulin was largely blocked in Wa5 osteoblasts, treatment with PTH induced ERK1/2 activation comparable to that observed in control osteoblasts, relative to baseline levels. Our data indicate that impairment of EGFR signaling does not affect the anabolic action of intermittent PTH on cancellous and cortical bone. Copyright © 2011. Published by Elsevier Inc.

  15. Epidermal growth factor receptor amplification does not have prognostic significance in patients with glioblastoma multiforme

    International Nuclear Information System (INIS)

    Quan, Aimee L.; Barnett, Gene H.; Lee, S.-Y.; Vogelbaum, Michael A.; Toms, Steven A.; Staugaitis, Susan M.; Prayson, Richard A.; Peereboom, David M.; Stevens, Glen H.J.; Cohen, Bruce H.; Suh, John H.

    2005-01-01

    Purpose: There have been conflicting reports in the literature regarding the prognostic significance of epidermal growth factor receptor (EGFR) amplification in patients with glioblastoma multiforme (GBM). The purpose of this study is to determine the prognostic significance of EGFR amplification in patients with GBM treated at Cleveland Clinic Foundation. Methods and Materials: A retrospective review of GBM patients treated with surgery at Cleveland Clinic Foundation was performed. Amplification of EGFR was evaluated with fluorescence in situ hybridization in a total of 107 patients diagnosed between December 1995 and May 2003. In addition to EGFR status, various prognostic factors were evaluated to determine the factors that influenced survival and radiographic response rate. The median follow-up was 9 months. Results: The overall median survival was 9.8 months, with a 1-year survival of 40%. Of the 107 patients in whom EGFR status was evaluated, 36 (33.6%) were found to have EGFR amplification. On multivariate analysis, median survival was found to be significantly improved for patients with age <60 (12.6 months vs. 8 months, p = 0.0061), patients with Karnofsky Performance Status ≥70 (12.1 months vs. 4.4 months, p < 0.0001), patients who had undergone subtotal resection or gross total resection (11.1 months vs. 4.1 months, p = 0.002), and patients who received a radiation dose ≥60 Gy compared with no radiation (12.7 months vs. 3 months, p < 0.0001). There was no association of EGFR amplification with survival. When stratified by age (<60 vs. ≥60), EGFR status still did not reach statistical significance in predicting for survival. For the 81 patients who had radiographic follow-up, the 1-year overall local control was 14%. On univariate analysis, only treatment with radiation (<60 Gy vs. ≥60 Gy vs. no radiation, p = 0.03) was found to predict for improved local control. Treatment with radiation did not remain statistically significant on multivariate

  16. Human Epidermal Growth Factor Receptor 2 Overexpression in Micropapillary and Other Variants of Urothelial Carcinoma.

    Science.gov (United States)

    Behzatoğlu, Kemal; Yörükoğlu, Kutsal; Demir, Hale; Bal, Nebil

    2016-06-21

    Human epidermal growth factor receptor 2 (HER2) protein overexpression or gene amplification has been shown in urothelial bladder cancer. This could be helpful when using targeted anti-HER2 therapy on these tumors. To evaluate HER2 immunohistochemical expression in conventional urothelial carcinoma (UC), in situ UC, and UC variants primarily in micropapillary urothelial carcinoma (MPUC). The study evaluated 60 MPUC cases; 25 invasive, 20 low-grade noninvasive, and 10 high-grade noninvasive UC cases; 8 in situ UC cases; and 69 UC variant cases. The immunohistochemistry staining was scored according to recommendations of the American Society of Clinical Oncology/College of American Pathologists 2013 HER2 test guideline established for breast cancer and only 3+ staining was considered HER2 overexpression. HER2 overexpression was determined by 3+ staining. 34 of 60 MPUC cases (56%) showed HER2 overexpression (3+ staining). We observed 3+ staining HER2 overexpression in nine of 25 conventional invasive UC cases (36%), four of eight in situ UC cases (50%), and three of six lipid cell variant cases (50%). 3+ staining HER2 overexpression was not seen in eight glandular, six small cell, and five sarcomatoid variant cases. HER2 overexpression was negative in the 20 low-grade noninvasive UC cases but positive in two of the 10 high-grade noninvasive UC cases (20%). We observed HER2 overexpression most commonly in MPUC cases. We also found HER2 overexpression in conventional invasive and in situ UC cases. Pure in situ UC and conventional invasive UC, especially MPUC, could be candidate tumors for treatment with anti-HER2 antibody (trastuzumab therapy). Targeted therapy has a limited place in treatment of bladder cancer. In this study, human epidermal growth factor receptor 2 (HER2) overexpression in bladder carcinomas was evaluated in a large number of cases. Anti-HER2 therapy could be used in bladder cancers, as in breast and gastric cancers. Copyright © 2016 European

  17. Expression and autoregulation of transforming growth factor beta receptor mRNA in small-cell lung cancer cell lines

    DEFF Research Database (Denmark)

    Nørgaard, P; Spang-Thomsen, M; Poulsen, H S

    1996-01-01

    In small-cell lung cancer cell lines resistance to growth inhibition by transforming growth factor (TGF)-beta 1, was previously shown to correlate with lack of TGF-beta receptor I (RI) and II (RII) proteins. To further investigate the role of these receptors, the expression of mRNA for RI, RII...... and beta-glycan (RIII) was examined. The results showed that loss of RII mRNA correlated with TGF-beta 1 resistance. In contrast, RI-and beta-glycan mRNA was expressed by all cell lines, including those lacking expression of these proteins. According to Southern blot analysis, the loss of type II m......RNA was not due to gross structural changes in the gene. The effect of TGF-beta 1 on expression of TGF-beta receptor mRNA (receptor autoregulation) was examined by quantitative Northern blotting in four cell lines with different expression of TGF-beta receptor proteins. In two cell lines expressing all three TGF...

  18. Microbial patterns signaling via Toll-like receptors 2 and 5 contribute to epithelial repair, growth and survival.

    Directory of Open Access Journals (Sweden)

    Renat Shaykhiev

    Full Text Available Epithelial cells (ECs continuously interact with microorganisms and detect their presence via different pattern-recognition receptors (PRRs including Toll-like receptors (TLRs. Ligation of epithelial TLRs by pathogens is usually associated with the induction of pro-inflammatory mediators and antimicrobial factors. In this study, using human airway ECs as a model, we found that detection of microbial patterns via epithelial TLRs directly regulates tissue homeostasis. Staphylococcus aureus (S. aureus and microbial patterns signaling via TLR2 and TLR5 induce a set of non-immune epithelial responses including cell migration, wound repair, proliferation, and survival of primary and cancerous ECs. Using small interfering RNA (siRNA gene targeting, receptor-tyrosine kinase microarray and inhibition studies, we determined that TLR and the epidermal growth factor receptor (EGFR mediate the stimulating effect of microbial patterns on epithelial repair. Microbial patterns signaling via Toll-like receptors 2 and 5 contribute to epithelial repair, growth and survival. This effect is independent of hematopoietic and other cells as well as inflammatory cytokines suggesting that epithelia are able to regulate their integrity in an autonomous non-inflammatory manner by sensing microbes directly via TLRs.

  19. Mechanisms of Inhibition of the Epidermal Growth Factor Receptor: Implications for Novel Anti-Cancer Therapies

    National Research Council Canada - National Science Library

    Klein, Daryl E

    2005-01-01

    .... No secreted or extracellular ErbB receptor inhibitors have been reported in mammals. However, two natural inhibitors of the highly homologous Drosophila EGF receptor are found in Drosophila melanogaster...

  20. Radiotherapy and receptor of epidermal growth factor; Radiotherapie et recepteur de l'Epidermal Growth Factor

    Energy Technology Data Exchange (ETDEWEB)

    Deberne, M. [Institut Gustave-Roussy, 94 - Villejuif (France)

    2009-10-15

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

  1. Epidermal Growth Factor Receptor Transactivation Is Required for Mitogen-Activated Protein Kinase Activation by Muscarinic Acetylcholine Receptors in HaCaT Keratinocytes

    Directory of Open Access Journals (Sweden)

    Wymke Ockenga

    2014-11-01

    Full Text Available 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.

  2. Dopamine receptor antagonist thioridazine inhibits tumor growth in a murine breast cancer model.

    Science.gov (United States)

    Yin, Tao; He, Sisi; Shen, Guobo; Ye, Tinghong; Guo, Fuchun; Wang, Yongsheng

    2015-09-01

    Neuropsychological factors have been shown to influence tumor progression and therapeutic response. The present study investigated the effect of the dopamine receptor antagonist thioridazine on murine breast cancer. The anti‑tumor efficacy of thioridazine was assessed using a murine breast cancer model. Cell apoptosis and proliferation were analyzed in vitro using flow cytometry (FCM) and the MTT assay, respectively. Western blot analysis was performed to assess Akt, phosphorylated (p)‑Akt, signal transducer and activator of transcription (STAT) 3, p‑STAT3 and p‑p65 in tumor cells following treatment with thioridazine. The Ki67 index and the number of terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL)‑positive apoptotic cells were assessed in the tumor sections. Thioridazine was found to reduce tumor growth, inhibit tumor cell proliferation and induce apoptosis in a dose‑ and time‑dependent manner in vitro. Thioridazine was also found to markedly inhibit tumor proliferation and induce tumor cell apoptosis in vivo as shown by the lower Ki67 index and increase in TUNEL‑positive cells. In addition, thioridazine was observed to inhibit the activation of the canonical nuclear factor κ‑light‑chain‑enhancer of activated B cells pathway and exert anti‑tumor effects by remodeling the tumor stroma, as well as inhibit angiogenesis in the tumor microenvironment. In conclusion, thioridazine was found to significantly inhibit breast tumor growth and the potential for thioridazine to be used in cancer therapy may be re‑evaluated and investigated in clinical settings.

  3. Kinetic analysis of platelet-derived growth factor receptor/phosphoinositide 3-kinase/Akt signaling in fibroblasts.

    Science.gov (United States)

    Park, Chang Shin; Schneider, Ian C; Haugh, Jason M

    2003-09-26

    Isoforms of the serine-threonine kinase Akt coordinate multiple cell survival pathways in response to stimuli such as platelet-derived growth factor (PDGF). Activation of Akt is a multistep process, which relies on the production of 3'-phosphorylated phosphoinositide (PI) lipids by PI 3-kinases. To quantitatively assess the kinetics of PDGF receptor/PI 3-kinase/Akt signaling in fibroblasts, a systematic study of this pathway was performed, and a mechanistic mathematical model that describes its operation was formulated. We find that PDGF receptor phosphorylation exhibits positive cooperativity with respect to PDGF concentration, and its kinetics are quantitatively consistent with a mechanism in which receptor dimerization is initially mediated by the association of two 1:1 PDGF/PDGF receptor complexes. Receptor phosphorylation is transient at high concentrations of PDGF, consistent with the loss of activated receptors upon endocytosis. By comparison, Akt activation responds to lower PDGF concentrations and exhibits more sustained kinetics. Further analysis and modeling suggest that the pathway is saturated at the level of PI 3-kinase activation, and that the p110alpha catalytic subunit of PI 3-kinase contributes most to PDGF-stimulated 3'-PI production. Thus, at high concentrations of PDGF the kinetics of 3'-PI production are limited by the turnover rate of these lipids, while the Akt response is additionally influenced by the rate of Akt deactivation.

  4. The growth hormone receptor polymorphism in patients with acromegaly: relationship to BMI and glucose metabolism.

    Science.gov (United States)

    Turgut, Sebahat; Akın, Fulya; Ayada, Ceylan; Topsakal, Senay; Yerlikaya, Emrah; Turgut, Günfer

    2012-09-01

    The aim of this study was to investigate association between the frequencies of Growth Hormone receptor (d3GHR) gene polymorphisms and some clinical parameters of acromegalic patients. Total of 35 acromegalic patients were enrolled to study. The d3GHR polymorphism was identified by using polymerase chain reaction from peripheral blood samples. The levels of systolic and diastolic blood pressure, BMI, fasting plasma glucose (FPG), Fasting insulin, HOMA-IR, IGF-I, GH, IGFBP3, triglyceride, HDL and LDL cholesterol concentrations were evaluated. The frequencies of d3GHR genotypes were found as follows; 5 (14.3%) subjects had d3/d3, 11 (31.4%) had d3/fl and 19 (54.3%) had fl/fl in patients. The prevalence of the d3 and fl alleles was 30 and 70%, respectively. Systolic blood pressure, fasting insulin and HOMA-IR was found significantly increased in homozygote d3GHR genotype group compared to d3/fl subjects (P d3GHR gene polymorphism may affect BMI, systolic blood pressure and insulin regulation. At the same time we can say homozygote d3GHR genotype and d3 allele carriers may have more risk than other genotypes for high BMI.

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

    International Nuclear Information System (INIS)

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

    2014-01-01

    Lung cancer leads cancer-related mortality worldwide. Non-small-cell lung cancer (NSCLC), the most prevalent subtype of this recalcitrant cancer, is usually diagnosed at advanced stages, and available systemic therapies are mostly palliative. The probing of the NSCLC kinome has identified numerous nonoverlapping driver genomic events, including epidermal growth factor receptor (EGFR) gene mutations. This review provides a synopsis of preclinical and clinical data on EGFR mutated NSCLC and EGFR tyrosine kinase inhibitors (TKIs). Classic somatic EGFR kinase domain mutations (such as L858R and exon 19 deletions) make tumors addicted to their signaling cascades and generate a therapeutic window for the use of ATP-mimetic EGFR TKIs. The latter inhibit these kinases and their downstream effectors, and induce apoptosis in preclinical models. The aforementioned EGFR mutations are stout predictors of response and augmentation of progression-free survival when gefitinib, erlotinib, and afatinib are used for patients with advanced NSCLC. The benefits associated with these EGFR TKIs are limited by the mechanisms of tumor resistance, such as the gatekeeper EGFR-T790M mutation, and bypass activation of signaling cascades. Ongoing preclinical efforts for treating resistance have started to translate into patient care (including clinical trials of the covalent EGFR-T790M TKIs AZD9291 and CO-1686) and hold promise to further boost the median survival of patients with EGFR mutated NSCLC

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

    Science.gov (United States)

    Cortés-Ramírez, Dionisio-Alejandro; Rodríguez-Tojo, María-Jose; Coca-Meneses, Juan-Carlos; Marichalar-Mendia, Xabier; Aguirre-Urizar, José-Manuel

    2014-09-01

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

  7. Role for the Epidermal Growth Factor Receptor in Chemotherapy-Induced Alopecia

    Science.gov (United States)

    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. PMID:23894460

  8. Altered expression of keratinocyte growth factor and its receptor in psoriasis.

    Science.gov (United States)

    Finch, P W; Murphy, F; Cardinale, I; Krueger, J G

    1997-12-01

    One of the biological characteristics of psoriasis is excessive flaking of the skin. This is directly related to the marked hyperplasia of epidermal keratinocytes and to incomplete epidermal differentiation. Keratinocyte growth factor (KGF), a potent mitogen for human keratinocytes, is expressed by stromal cells. Alterations in the KGF signaling pathway might account for the epidermal hyperplasia associated with psoriasis. To test this hypothesis, we investigated the expression of KGF and its receptor (KGFR) in psoriasis tissue. KGF and KGFR mRNA levels were found to be frequently elevated in psoriatic skin specimens as compared with normal skin. Increased KGF transcript expression was localized to the dermal layer of the involved skin specimen using in situ hybridization. In contrast, KGFR transcript and protein expression was localized to the basal layer of keratinocytes in normal skin and to the basal and suprabasal layers of the psoriatic epidermis, coincident with the expanded proliferative keratinocyte pool. To identify molecules that might regulate KGFR expression we investigated the effects of various pharmacological agents and cytokines on KGFR synthesis by keratinocytes. Phorbol ester, interleukin-6, interferon-gamma, and ultraviolet B (UVB) treatment all led to substantial down-regulation of KGFR expression. The down-regulation of KGFR synthesis by UVB suggests a possible mechanism for the antiproliferative action of this agent in the treatment of psoriasis. Taken together, these results suggest that increased KGFR-mediated signaling in keratinocytes in the lesional epidermis might account in part for the epidermal hyperplasia in psoriasis.

  9. Platelet-derived growth factor receptors (PDGFRs) fusion genes involvement in hematological malignancies.

    Science.gov (United States)

    Appiah-Kubi, Kwaku; Lan, Ting; Wang, Ying; Qian, Hai; Wu, Min; Yao, Xiaoyuan; Wu, Yan; Chen, Yongchang

    2017-01-01

    To investigate oncogenic platelet-derived growth factor receptor(PDGFR) fusion genes involvement in hematological malignancies, the advances in the PDGFR fusion genes diagnosis and development of PDGFR fusions inhibitors. Literature search was done using terms "PDGFR and Fusion" or "PDGFR and Myeloid neoplasm" or 'PDGFR and Lymphoid neoplasm' or "PDGFR Fusion Diagnosis" or "PDGFR Fusion Targets" in databases including PubMed, ASCO.org, and Medscape. Out of the 36 fusions detected, ETV6(TEL)-PDGFRB and FIP1L1-PDGFRA fusions were frequently detected, 33 are as a result of chromosomal translocation, FIP1L1-PDGFRA and EBF1-PDGFRB are the result of chromosomal deletion and CDK5RAP2- PDGFRΑ is the result of chromosomal insertion. Seven of the 34 rare fusions have detectable reciprocals. RNA aptamers are promising therapeutic target of PDGFRs and diagnostic tools of PDGFRs fusion genes. Also, PDGFRs have variable prospective therapeutic strategies including small molecules, RNA aptamers, and interference therapeutics as well as development of adaptor protein Lnk mimetic drugs. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  10. Evaluation of growth hormone (GH) action in mice: discovery of GH receptor antagonists and clinical indications.

    Science.gov (United States)

    Kopchick, John J; List, Edward O; Kelder, Bruce; Gosney, Elahu S; Berryman, Darlene E

    2014-04-05

    The discovery of a growth hormone receptor antagonist (GHA) was initially established via expression of mutated GH genes in transgenic mice. Following this discovery, development of the compound resulted in a drug termed pegvisomant, which has been approved for use in patients with acromegaly. Pegvisomant treatment in a dose dependent manner results in normalization of IGF-1 levels in most patients. Thus, it is a very efficacious and safe drug. Since the GH/IGF-1 axis has been implicated in the progression of several types of cancers, many have suggested the use of pegvisomant as an anti-cancer therapeutic. In this manuscript, we will review the use of mouse strains that possess elevated or depressed levels of GH action for unraveling many of GH actions. Additionally, we will describe experiments in which the GHA was discovered, review results of pegvisomant's preclinical and clinical trials, and provide data suggesting pegvisomant's therapeutic value in selected types of cancer. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  11. Catalase reverses tumorigenicity in a malignant cell line by an epidermal growth factor receptor pathway.

    Science.gov (United States)

    Finch, Joanne S; Tome, Margaret E; Kwei, Kevin A; Bowden, G Tim

    2006-03-01

    We have used a keratinocyte in vivo/in vitro cell model to test the hypothesis that hydrogen peroxide acts as a signaling molecule, contributing to proliferation and tumorigenesis. A cell line, 6M90, that produces squamous cell carcinoma (SCC), has high levels of ROS and low levels of catalase. A new cell line, MTOC2, generated from parental 6M90 cells by introduction of a Tet-responsive catalase transgene, effectively expressed higher peroxisomal catalase. Increased catalase expression diminished constitutive ROS and enhanced viability after treatment with hydrogen peroxide. Protein tyrosine phosphatase activity was higher in the MTOC2 cells with high catalase, consistent with detection of a lower level of phosphorylation at tyrosine 1068 of the epidermal growth factor receptor (EGF-R). Transcription of downstream c-fos, AP-1 transactivation and cell proliferation were higher in the low catalase cells. An EGF-R inhibitor, AG1478, blocks the higher AP-1 transactivation and cell proliferation of the low catalase 6M90 cells. Tumorigenesis in SCID mice was greatly diminished in the high catalase cells. Our data suggest that hydrogen peroxide functions as a signaling molecule that can modulate activity of a protein tyrosine phosphatase/(s) resulting in phosphorylation of tryrosine/(s) on the EGF-R. Therefore, catalase acts as a tumor-suppressor gene in part by decreasing EGF-R signaling.

  12. Insulin-like growth factor 1 receptor regulates hypothermia during calorie restriction.

    Science.gov (United States)

    Cintron-Colon, Rigo; Sanchez-Alavez, Manuel; Nguyen, William; Mori, Simone; Gonzalez-Rivera, Ruben; Lien, Tiffany; Bartfai, Tamas; Aïd, Saba; François, Jean-Christophe; Holzenberger, Martin; Conti, Bruno

    2017-09-05

    When food resources are scarce, endothermic animals can lower core body temperature (T b ). This phenomenon is believed to be part of an adaptive mechanism that may have evolved to conserve energy until more food becomes available. Here, we found in the mouse that the insulin-like growth factor 1 receptor (IGF-1R) controls this response in the central nervous system. Pharmacological or genetic inhibition of IGF-1R enhanced the reduction of temperature and of energy expenditure during calorie restriction. Full blockade of IGF-1R affected female and male mice similarly. In contrast, genetic IGF-1R dosage was effective only in females, where it also induced transient and estrus-specific hypothermia in animals fed ad libitum. These effects were regulated in the brain, as only central, not peripheral, pharmacological activation of IGF-1R prevented hypothermia during calorie restriction. Targeted IGF-1R knockout selectively in forebrain neurons revealed that IGF signaling also modulates calorie restriction-dependent T b regulation in regions rostral of the canonical hypothalamic nuclei involved in controlling body temperature. In aggregate, these data identify central IGF-1R as a mediator of the integration of nutrient and temperature homeostasis. They also show that calorie restriction, IGF-1R signaling, and body temperature, three of the main regulators of metabolism, aging, and longevity, are components of the same pathway.

  13. Development of novel epidermal growth receptor-based radiopharmaceuticals: Imaging agents for breast cancer

    International Nuclear Information System (INIS)

    Van Brocklin, Henry F.

    2001-01-01

    The goal of this research was to develop epidermal growth factor receptor (EGFR) nuclear medicine breast cancer imaging agents. Our approach was to synthesize small molecule inhibitors of the EGFR tyrosine kinase (tk) suitable for labeling with single photon or positron-emitting radioisotopes and evaluate the imaging potential of these new molecules.We have synthesized and fully characterized 22 quinazoline compounds. All compounds inhibit EGFR tk phosphorylation activity in the nanomolar range. All compounds tested exhibited specificity for the EGFR tk versus the ErbB2 and ErbB4 tyrosine kinases. A radiometric binding assay using an iodine-125 labeled quinazoline was developed to determine the affinity of the quinazolines for the EGFR tk ATP binding site. The affinities ranged from 0.4-51 nM. The octanol/water partition coefficients (Log P; lipophilicity) of the new compounds ranged from 2.2-5.5. Six compounds have been labeled with fluorine-18. Biodistribution in EGFR overexpressing tumor bearing mice demonstrated tumor uptake but highlighted delivery and metabolism issues. The 2-fluoro quinazoline was not metabolized in an in vitro hepatocyte study. From this work a breadth of agent characteristics was created establishing the foundation for future research toward the optimal EGFR imaging agent

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

    Directory of Open Access Journals (Sweden)

    Lamond NW

    2014-05-01

    Full Text Available Nathan WD Lamond, Tallal YounisDepartment of Medicine, Dalhousie University at the Queen Elizabeth II Health Sciences Centre, Halifax, NS, CanadaAbstract: 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.Keywords: HER2/neu, clinical trials, drug development, novel therapies, targeted anticancer therapy

  15. Resistance to Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitors in Non-Small Cell Lung Cancer.

    Science.gov (United States)

    Hammerman, Peter S; Jänne, Pasi A; Johnson, Bruce E

    2009-12-15

    Gefitinib and erlotinib are ATP competitive inhibitors of the epidermal growth factor receptor (EGFR) tyrosine kinase and are approved around the world for the treatment of patients with non-small cell lung cancer (NSCLC). Somatic mutations in the EGFR are found in 10 to 40% of patients with NSCLC. Patients with sensitizing somatic mutations of EGFR treated with gefitinib or erlotinib have an initial clinical response of 60 to 80%, approximately twice as high as the responses associated with the administration of conventional platinum-based chemotherapy. However, the efficacy of EGFR tyrosine kinase inhibitors (TKI) is limited by either primary (de novo) or acquired resistance after therapy and investigations to define the mechanisms of resistance are active areas of ongoing preclinical and clinical studies. Primary resistance is typically caused by other somatic mutations in genes such as KRAS, which also have an impact on the EGFR signaling pathway or by mutations in the EGFR gene that are not associated with sensitivity to EGFR-TKIs. Two established mechanisms of acquired resistance are caused by additional mutations in the EGFR gene acquired during the course of treatment that change the protein-coding sequence or by amplification of another oncogene signaling pathway driven by the MET oncogene. This review focuses on characterized mechanisms of resistance to the EGFR TKIs and efforts to overcome the problem of resistance aimed at improving the therapy of patients with NSCLC. (Clin Cancer Res 2009;15(24):7502-9).

  16. Strategies to overcome resistance to epidermal growth factor receptor monoclonal antibody therapy in metastatic colorectal cancer.

    Science.gov (United States)

    Jeong, Woo-Jeong; Cha, Pu-Hyeon; Choi, Kang-Yell

    2014-08-07

    Administration of monoclonal antibodies (mAbs) against epidermal growth factor receptor (EGFR) such as cetuximab and panitumumab in combination with conventional chemotherapy substantially prolongs survival of patients with metastatic colorectal cancer (mCRC). However, the efficacy of these mAbs is limited due to genetic variation among patients, in particular K-ras mutations. The discovery of K-ras mutation as a predictor of non-responsiveness to EGFR mAb therapy has caused a major change in the treatment of mCRC. Drugs that inhibit transformation caused by oncogenic alterations of Ras and its downstream components such as BRAF, MEK and AKT seem to be promising cancer therapeutics as single agents or when given with EGFR inhibitors. Although multiple therapeutic strategies to overcome EGFR mAb-resistance are under investigation, our understanding of their mode of action is limited. Rational drug development based on stringent preclinical data, biomarker validation, and proper selection of patients is of paramount importance in the treatment of mCRC. In this review, we will discuss diverse approaches to overcome the problem of resistance to existing anti-EGFR therapies and potential future directions for cancer therapies related to the mutational status of genes associated with EGFR-Ras-ERK and PI3K signalings.

  17. Epidermal Growth Factor Receptor Inconsistency by Immunohistochemistry Method Using Different Monoclonal Antibodies in Colorectal Cancer Patients.

    Science.gov (United States)

    Fan, Chi-Chen; Wang, Tao-Yeuan; Kung, Chien-Min

    2015-01-01

    Targeted therapy is typically used to treat colorectal cancer (CRC). The epidermal growth factor receptor (EGFR) was recognized as a potential therapeutic target. Does the EGFR protein express consistently using different monoclonal antibodies in clinics? One hundred and sixty-four patients (mean age 61.80 ± 12.78 years) who suffered from CRC were selected at Mackay Memorial Hospital in Taiwan. Formalin-fixed and paraffin-embedded tissue sections from all patients were tested simultaneously using two commercial antibodies, Dako-EGFR (mouse monoclonal anti-EGFR clone 2-18C9, pharmDx) and NCL-EGFR (NCL-EGFR-384, Novocastra) monoclonal antibodies, to study the commutability or equality of the qualities of EGFR expression by standard immunohistochemistry (IHC) procedures. The EGFR expressions that were obtained by IHC staining using different monoclonal antibodies with Dako-EGFR (46.95%) and NCL-EGFR (32.32%) were fairly concordant. Although IHC is a convenient and feasible method for detecting the expression of EGFR, it yields controversial staining results concerning EGFR expression using various commercial antibodies in a CRC tumor section.

  18. Fibroblast growth factor receptor 4 polymorphism is associated with liver cirrhosis in hepatocarcinoma.

    Directory of Open Access Journals (Sweden)

    Ming-Jen Sheu

    Full Text Available Fibroblast growth factor receptor 4 (FGFR4 polymorphisms are positively correlated with tumor progression in numerous malignant tumors. However, the association between FGFR4 genetic variants and the risk of hepatocellular carcinoma (HCC has not yet been determined. In this study, we investigated the potential associations of FGFR4 single nucleotide polymorphisms (SNPs with HCC susceptibility and its clinicopathological characteristics.Four SNPs in FGFR4 (rs1966265, rs351855, rs2011077, and rs7708357 were analyzed among 884 participants, including 595 controls and 289 patients with HCC. The samples were further analyzed to clarify the associations between these gene polymorphisms and the risk of HCC, and the impact of these SNPs on the susceptibility and clinicopathological characteristics of HCC. After adjusting for other covariants, HCC patients who carrying at least one A genotype (GA and AA at rs351855 were observed to have a higher risk of liver cirrhosis compared with those carrying the wild-type genotype (GG (OR: 2.113, 95% CI: 1.188-3.831. Moreover, the patients with at least one A genotype were particularly showed a high level of alpha-fetoprotein (AFP.Our findings suggest that genetic polymorphism in FGFR4 rs351855 may be associated with the risk of HCC coupled with liver cirrhosis and may markedly increase the AFP level in Taiwanese patients with HCC. In addition, this is the first study that evaluated the risk factors associated with FGFR4 polymorphism variants in Taiwanese patients with HCC.

  19. Frequency of Epidermal Growth Factor Receptor Mutation in Smokers with Lung Cancer Without Pulmonary Emphysema.

    Science.gov (United States)

    Takeda, Kenichi; Yamasaki, Akira; Igishi, Tadashi; Kawasaki, Yuji; Ito-Nishii, Shizuka; Izumi, Hiroki; Sakamoto, Tomohiro; Touge, Hirokazu; Kodani, Masahiro; Makino, Haruhiko; Yanai, Masaaki; Tanaka, Natsumi; Matsumoto, Shingo; Araki, Kunio; Nakamura, Hiroshige; Shimizu, Eiji

    2017-02-01

    Chronic obstructive pulmonary disease is a smoking-related disease, and is categorized into the emphysema and airway dominant phenotypes. We examined the relationship between emphysematous changes and epidermal growth factor receptor (EGFR) mutation status in patients with lung adenocarcinoma. The medical records for 250 patients with lung adenocarcinoma were retrospectively reviewed. All patients were categorized into the emphysema or non-emphysema group. Wild-type EGFR was detected in 136 (54%) and mutant EGFR in 48 (19%). Emphysematous changes were observed in 87 (36%) patients. EGFR mutation was highly frequent in the non-emphysema group (p=0.0014). Multivariate logistic regression analysis showed that emphysema was an independent risk factor for reduced frequency of EGFR mutation (Odds Ratio=3.47, p=0.005). Our data showed a relationship between emphysematous changes and EGFR mutation status. There might be mutually exclusive genetic risk factors for carcinogenesis and development of emphysematous changes. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

  20. Exploring adjuvant epidermal growth factor receptor inhibition in non-small cell lung cancer.

    Science.gov (United States)

    Stella, Giulia M; Piloni, Davide

    2017-06-01

    Lung cancer is among the most important causes of death worldwide. Despite the relevant progresses in the personalized approach to lung cancer, patients' survival is still poor. Only a minor fraction of patients can be addressed to surgery for radical tumor removal. Adjuvant chemotherapy is currently recommended for resected stages II and III patients although it is known that it can modestly contribute to survival prolongation. A better identification of molecular markers, predictive of adjuvant chemo response is now mandatory, in order to reduce useless toxicities and identify those patients who could really benefit. Here we present and analyze a recent paper by Huang et al. aimed at evaluating the prognostic role of epidermal growth factor receptor (EGFR) activation in adjuvant setting in order to determine whether the administration of EGFR tyrosine-kinase inhibitors could improve the outcomes of patients affected by NSCLC undergoing complete resection. Moreover we provide an exhaustive literature revision that could be helpful for a proper management of that small cohort of EGFR-mutated resected NSCLC.

  1. Blockade of Vascular Endothelial Growth Factor Receptor 1 Prevents Inflammation and Vascular Leakage in Diabetic Retinopathy

    Directory of Open Access Journals (Sweden)

    Jianbo He

    2015-01-01

    Full Text Available Diabetic retinopathy (DR is a leading cause of blindness in working age adults. The objective of this study is to investigate the effects of vascular endothelial growth factor receptor 1 (VEGFR1 blockade on the complications of DR. Experimental models of diabetes were induced with streptozotocin (STZ treatment or Insulin2 gene mutation (Akita in mice. Protein expression and localization were examined by western blots (WB and immunofluorescence (IF. mRNA expression was quantified by PCR array and real-time PCR. The activity of VEGFR1 signaling was blocked by a neutralizing antibody called MF1. Vascular leakage was evaluated by measuring the leakage of [3H]-mannitol tracer into the retina and the IF staining of albumin. VEGFR1 blockade significantly inhibited diabetes-related vascular leakage, leukocytes-endothelial cell (EC adhesion (or retinal leukostasis, expression of intercellular adhesion molecule- (ICAM- 1 protein, abnormal localization and degeneration of the tight junction protein zonula occludens- (ZO- 1, and the cell adhesion protein vascular endothelial (VE cadherin. In addition, VEGFR1 blockade interfered with the gene expression of 10 new cytokines and chemokines: cxcl10, il10, ccl8, il1f6, cxcl15, ccl4, il13, ccl6, casp1, and ccr5. These results suggest that VEGFR1 mediates complications of DR and targeting this signaling pathway represents a potential therapeutic strategy for the prevention and treatment of DR.

  2. Growth hormone activity in mitochondria depends on GH receptor Box 1 and involves caveolar pathway targeting

    International Nuclear Information System (INIS)

    Perret-Vivancos, Cecile; Abbate, Aude; Ardail, Dominique; Raccurt, Mireille; Usson, Yves; Lobie, Peter E.; Morel, Gerard

    2006-01-01

    Growth hormone (GH) binding to its receptor (GHR) initiates GH-dependent signal transduction and internalization pathways to generate the biological effects. The precise role and way of action of GH on mitochondrial function are not yet fully understood. We show here that GH can stimulate cellular oxygen consumption in CHO cells transfected with cDNA coding for the full-length GHR. By using different GHR cDNA constructs, we succeeded in determining the different parts of the GHR implicated in the mitochondrial response to GH. Polarography and two-photon excitation fluorescence microscopy analysis showed that the Box 1 of the GHR intracellular domain was required for an activation of the mitochondrial respiration in response to a GH exposure. However, confocal laser scanning microscopy demonstrated that cells lacking the GHR Box 1 could efficiently internalize the hormone. We demonstrated that internalization mediated either by clathrin-coated pits or by caveolae was able to regulate GH mitochondrial effect: these two pathways are both essential to obtain the GH stimulatory action on mitochondrial function. Moreover, electron microscopic and biochemical approaches allowed us to identify the caveolar pathway as essential for targeting GH and GHR to mitochondria

  3. Human epidermal growth factor receptor2 expression in unresectable gastric cancers: Relationship with CT characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jeong Sub [Dept. of Radiology, Jeju National University Hospital, Jeju (Korea, Republic of); Kim, Se Hyung; Im, Seock Ah; Kim, Min A; Han, Joon Koo [Seoul National University Hospital, Seoul (Korea, Republic of)

    2017-09-15

    To retrospectively analyze the qualitative CT features that correlate with human epidermal growth factor receptor 2 (HER2)-expression in pathologically-proven gastric cancers. A total of 181 patients with pathologically-proven unresectable gastric cancers with HER2-expression (HER2-positive [n = 32] and negative [n = 149]) were included. CT features of primary gastric and metastatic tumors were reviewed. The prevalence of each CT finding was compared in both groups. Thereafter, binary logistic regression determined the most significant differential CT features. Clinical outcomes were compared using Kaplan-Meier method. HER2-postive cancers showed lower clinical T stage (21.9% vs. 8.1%; p = 0.015), hyperattenuation on portal phase (62.5% vs. 30.9%; p = 0.003), and was more frequently metastasized to the liver (62.5% vs. 32.2%; p = 0.001), than HER2-negative cancers. On binary regression analysis, hyperattenuation of the tumor (odds ratio [OR], 4.68; p < 0.001) and hepatic metastasis (OR, 4.43; p = 0.001) were significant independent factors that predict HER2-positive cancers. Median survival of HER2-positive cancers (13.7 months) was significantly longer than HER2-negative cancers (9.6 months) (p = 0.035). HER2-positive gastric cancers show less-advanced T stage, hyperattenuation on the portal phase, and frequently metastasize to the liver, as compared to HER2-negative cancers.

  4. Global Developmental Gene Programing Involves a Nuclear Form of Fibroblast Growth Factor Receptor-1 (FGFR1.

    Directory of Open Access Journals (Sweden)

    Christopher Terranova

    Full Text Available Genetic studies have placed the Fgfr1 gene at the top of major ontogenic pathways that enable gastrulation, tissue development and organogenesis. Using genome-wide sequencing and loss and gain of function experiments the present investigation reveals a mechanism that underlies global and direct gene regulation by the nuclear form of FGFR1, ensuring that pluripotent Embryonic Stem Cells differentiate into Neuronal Cells in response to Retinoic Acid. Nuclear FGFR1, both alone and with its partner nuclear receptors RXR and Nur77, targets thousands of active genes and controls the expression of pluripotency, homeobox, neuronal and mesodermal genes. Nuclear FGFR1 targets genes in developmental pathways represented by Wnt/β-catenin, CREB, BMP, the cell cycle and cancer-related TP53 pathway, neuroectodermal and mesodermal programing networks, axonal growth and synaptic plasticity pathways. Nuclear FGFR1 targets the consensus sequences of transcription factors known to engage CREB-binding protein, a common coregulator of transcription and established binding partner of nuclear FGFR1. This investigation reveals the role of nuclear FGFR1 as a global genomic programmer of cell, neural and muscle development.

  5. The incidence and management of cutaneous adverse events of the epidermal growth factor receptor inhibitors

    Directory of Open Access Journals (Sweden)

    Witold Owczarek

    2017-10-01

    Full Text Available Overexpression of the epidermal growth factor receptor (EGFR is found in many cancers, including those of the head and neck area, non-small-cell lung cancer, and colorectal, cervical, prostate, breast, ovary, stomach, and pancreatic cancer. The EGFR inhibitors are used at present in the treatment of such cancers. Skin lesions that develop during and after cancer treatment may be due to specific cytostatics, molecular-targeted drugs, radiation therapy, complementary therapy, or the cancer itself, and hence knowledge is essential to distinguish between them. The mechanism through which skin toxicity arises during treatment with EGFR inhibitors is not well known, but seems to be due to the modification of the RAS/RAF/MEK/ERK signal path associated with its activation, which results in the similarity between the adverse effects of EGFR inhibitors and the treatment of melanoma with BRAF and MEK inhibitors. The most common side effects are pruritus, xerosis, papulopustular rash, hand-foot skin reaction, alopecia and dystrophy of the hair, and paronychia. This work presents options for prevention and suggestions for managing these adverse events, which are of importance in the care of patients undergoing oncological treatment.

  6. Radiogenomic correlation in lung adenocarcinoma with epidermal growth factor receptor mutations: Imaging features and histological subtypes

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Su Jin [Seoul National University Bundang Hospital, Department of Radiology, Seongnam-si, Gyeonggi-do (Korea, Republic of); Hanyang University, Department of Radiology, School of Medicine, Seoul (Korea, Republic of); Kim, Tae Jung [Seoul National University Bundang Hospital, Department of Radiology, Seongnam-si, Gyeonggi-do (Korea, Republic of); Samsung Medical Center, Department of Radiology, Seoul (Korea, Republic of); Choi, Yo Won [Hanyang University, Department of Radiology, School of Medicine, Seoul (Korea, Republic of); Park, Jeong-Soo [Dankook Universicity, Department of Biochemistry, College of Medicine, Cheonan (Korea, Republic of); Chung, Jin-Haeng [Seoul National University Bundang Hospital, Department of Pathology, Seongnam-si, Gyeonggi-do (Korea, Republic of); Lee, Kyung Won [Seoul National University Bundang Hospital, Department of Radiology, Seongnam-si, Gyeonggi-do (Korea, Republic of)

    2016-10-15

    To correlate imaging features of resected lung adenocarcinoma with epidermal growth factor receptor (EGFR) mutation and the IASLC/ATS/ERS classification histological subtypes. In 250 consecutive patients with resected lung adenocarcinoma, EGFR mutation status was correlated with demographics, imaging features including ground-glass opacity (GGO) proportion and the IASLC/ATS/ERS classification histological subtypes. EGFR mutations were significantly more frequent in women (54.5 % vs. 38.1 %, p = 0.011) and in never-smokers (54.7 % vs. 35.3 %, p = 0.003). GGO proportion was significantly higher in tumours with EGFR mutation than in those without (30.3 ± 33.8 % vs. 19.0 ± 29.3 %, p = 0.005). EGFR mutation was significantly more frequent in tumours with GGO ≥ 50 % and tumours with any GGO (p = 0.026 and 0.008, respectively). Adenocarcinomas with exon 19 or 21 mutation showed significantly higher GGO proportion than that in EGFR wild-type tumours (p = 0.009 and 0.029, respectively). Absence of GGO was an independent predictor of negative EGFR mutation (odds ratio, 1.81; 95 % confidence interval, 1.16-3.04; p = 0.018). GGO proportion in adenocarcinomas with EGFR mutation was significantly higher than that in EGFR wild-type tumours, and the absence of GGO on CT was an independent predictor of negative EGFR mutation. (orig.)

  7. Dialkoxyquinazolines: Screening Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitors for Potential Tumor Imaging Probes

    International Nuclear Information System (INIS)

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

    2005-01-01

    The epidermal growth factor receptor (EGFR), a long-standing drug development target, is also a desirable target for imaging. Sixteen dialkoxyquinazoline analogs, suitable for labeling with positron-emitting isotopes, have been synthesized and evaluated in a battery of in vitro assays to ascertain their chemical and biological properties. These characteristics provided the basis for the adoption of a selection schema to identify lead molecules for labeling and in vivo evaluation. A newEGFR tyrosine kinase radiometric binding assay revealed that all of the compounds possessed suitable affinity (IC50 = 0.4 - 51 nM) for the EGFR tyrosine kinase. All of the analogs inhibited ligand-induced EGFR tyrosine phosphorylation (IC50 = 0.8 - 20 nM). The HPLC-estimated octanol/water partition coefficients ranged from 2.0-5.5. Four compounds,4-(2'-fluoroanilino)- and 4-(3'-fluoroanilino)-6,7-diethoxyquinazoline as well as 4-(3'-chloroanilino)- and4-(3'-bromoanilino)-6,7-dimethoxyquinazoline, possess the best combination of characteristics that warrant radioisotope labeling and further evaluation in tumor-bearing mice

  8. Overexpression of Insulin-like Growth Factor-1 Receptor Is Associated With Penile Cancer Progression.

    Science.gov (United States)

    Ball, Mark W; Bezerra, Stephania M; Chaux, Alcides; Faraj, Sheila F; Gonzalez-Roibon, Nilda; Munari, Enrico; Sharma, Rajni; Bivalacqua, Trinity J; Netto, George J; Burnett, Arthur L

    2016-06-01

    To evaluate insulin-like growth factor-1 receptor (IGF1R) expression in penile cancer and its association with oncologic outcomes. Tissue microarrays were constructed from 53 patients treated at our institution. Expression of IGF1R was evaluated using a Her2-like scoring system. Overexpression was defined as 1+ or greater membranous staining. Association of IGF1R expression with pathologic features was assessed with comparative statistics, and association with local recurrence, progression to nodal or distance metastases, or death was assessed with Kaplan-Meier survival analysis and Cox proportional hazard regression models. Overall, IGF1R overexpression was seen in 33 (62%) cases. With a median follow-up of 27.8 months, IGF1R overexpression was associated with inferior progression-free survival (PFS) (P  =  .003). In a multivariable model controlling for grade, T stage, perineural invasion, and lymphovascular invasion, IGF1R expression was independently associated with disease progression (hazard ratio 2.3, 95% confidence interval 1.1-5.1, P  =  .03. Comparing patients without IGF1R overexpression to those with overexpression, 5-year PFS was 94.1% vs 45.8%. IGF1R overexpression was associated with inferior PFS in penile cancer. Drugs that target IGF1R and downstream messengers may have a therapeutic benefit in patients that exhibit IGF1R overexpression. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. Genetic dissection of epidermal growth factor receptor signaling during luteinizing hormone-induced oocyte maturation.

    Directory of Open Access Journals (Sweden)

    Minnie Hsieh

    Full Text Available Recent evidence that luteinizing hormone (LH stimulation of ovulatory follicles causes transactivation of the epidermal growth factor receptor (EGFR has provided insights into the mechanisms of ovulation. However, the complete array of signals that promote oocyte reentry into the meiotic cell cycle in the follicle are still incompletely understood. To elucidate the signaling downstream of EGFR involved in oocyte maturation, we have investigated the LH responses in granulosa cells with targeted ablation of EGFR. Oocyte maturation and ovulation is disrupted when EGFR expression is progressively reduced. In granulosa cells from mice with either global or granulosa cell-specific disruption of EGFR signaling, LH-induced phosphorylation of MAPK3/1, p38MAPK, and connexin-43 is impaired. Although the LH-induced decrease in cGMP is EGFR-dependent in wild type follicles, LH still induces a decrease in cGMP in Egfr(delta/f Cyp19-Cre follicles. Thus compensatory mechanisms appear activated in the mutant. Spatial propagation of the LH signal in the follicle also is dependent on the EGF network, and likely is important for the control of signaling to the oocyte. Thus, multiple signals and redundant pathways contribute to regulating oocyte reentry into the cell cycle.

  10. Optimization of 1H-indazol-3-amine derivatives as potent fibroblast growth factor receptor inhibitors.

    Science.gov (United States)

    Cui, Jing; Peng, Xia; Gao, Dingding; Dai, Yang; Ai, Jing; Li, Yingxia

    2017-08-15

    Fibroblast growth factor receptor (FGFR) is a potential target for cancer therapy because of its critical role in promoting cancer formation and progression. In a continuing effort to improve the cellular activity of hit compound 7r bearing an indazole scaffold, which was previously discovered by our group, several compounds harnessing fluorine substituents were designed, synthesized and biological evaluated. Besides, the region extended out to the ATP binding pocket toward solvent was also explored. Among them, compound 2a containing 2,6-difluoro-3-methoxyphenyl residue exhibited the most potent activities (FGFR1: less than 4.1nM, FGFR2: 2.0±0.8nM). More importantly, compound 2a showed an improved antiproliferative effect against KG1 cell lines and SNU16 cell lines with IC 50 values of 25.3±4.6nM and 77.4±6.2nM respectively. Copyright © 2017. Published by Elsevier Ltd.

  11. Brain metastasis in human epidermal growth factor receptor 2-positive breast cancer: from biology to treatment

    Energy Technology Data Exchange (ETDEWEB)

    Koo, Tae Ryool [Dept. of Radiation Oncology, Hallym University Chuncheon Sacred Heart Hospital, Chuncheon (Korea, Republic of); Kim, In Ah [Dept. of Radiation Oncology, Seoul National University Bundang Hospital, Seongnam (Korea, Republic of)

    2016-03-15

    Overexpression of human epidermal growth factor receptor 2 (HER2) is found in about 20% of breast cancer patients. With treatment using trastuzumab, an anti-HER2 monoclonal antibody, systemic control is improved. Nonetheless, the incidence of brain metastasis does not be improved, rather seems to be increased in HER2-positive breast cancer. The mainstay treatment for brain metastases is radiotherapy. According to the number of metastatic lesions and performance status of patients, radiosurgery or whole brain radiotherapy can be performed. The concurrent use of a radiosensitizer further improves intracranial control. Due to its large molecular weight, trastuzumab has a limited ability to cross the blood-brain barrier. However, small tyrosine kinase inhibitors such as lapatinib, has been noted to be a promising agent that can be used as a radiosensitizer to affect HER2-positive breast cancer. This review will outline general management of brain metastases and will focus on preclinical findings regarding the radiosensitizing effect of small molecule HER2 targeting agents.

  12. Global Developmental Gene Programing Involves a Nuclear Form of Fibroblast Growth Factor Receptor-1 (FGFR1).

    Science.gov (United States)

    Terranova, Christopher; Narla, Sridhar T; Lee, Yu-Wei; Bard, Jonathan; Parikh, Abhirath; Stachowiak, Ewa K; Tzanakakis, Emmanuel S; Buck, Michael J; Birkaya, Barbara; Stachowiak, Michal K

    2015-01-01

    Genetic studies have placed the Fgfr1 gene at the top of major ontogenic pathways that enable gastrulation, tissue development and organogenesis. Using genome-wide sequencing and loss and gain of function experiments the present investigation reveals a mechanism that underlies global and direct gene regulation by the nuclear form of FGFR1, ensuring that pluripotent Embryonic Stem Cells differentiate into Neuronal Cells in response to Retinoic Acid. Nuclear FGFR1, both alone and with its partner nuclear receptors RXR and Nur77, targets thousands of active genes and controls the expression of pluripotency, homeobox, neuronal and mesodermal genes. Nuclear FGFR1 targets genes in developmental pathways represented by Wnt/β-catenin, CREB, BMP, the cell cycle and cancer-related TP53 pathway, neuroectodermal and mesodermal programing networks, axonal growth and synaptic plasticity pathways. Nuclear FGFR1 targets the consensus sequences of transcription factors known to engage CREB-binding protein, a common coregulator of transcription and established binding partner of nuclear FGFR1. This investigation reveals the role of nuclear FGFR1 as a global genomic programmer of cell, neural and muscle development.

  13. Biologic effects of platelet-derived growth factor receptor α blockade in uterine cancer.

    Science.gov (United States)

    Roh, Ju-Won; Huang, Jie; Hu, Wei; Yang, XiaoYun; Jennings, Nicholas B; Sehgal, Vasudha; Sohn, Bo Hwa; Han, Hee Dong; Lee, Sun Joo; Thanapprapasr, Duangmani; Bottsford-Miller, Justin; Zand, Behrouz; Dalton, Heather J; Previs, Rebecca A; Davis, Ashley N; Matsuo, Koji; Lee, Ju-Seog; Ram, Prahlad; Coleman, Robert L; Sood, Anil K

    2014-05-15

    Platelet-derived growth factor receptor α (PDGFRα) expression is frequently observed in many kinds of cancer and is a candidate for therapeutic targeting. This preclinical study evaluated the biologic significance of PDGFRα and PDGFRα blockade (using a fully humanized monoclonal antibody, 3G3) in uterine cancer. Expression of PDGFRα was examined in uterine cancer clinical samples and cell lines, and biologic effects of PDGFRα inhibition were evaluated using in vitro (cell viability, apoptosis, and invasion) and in vivo (orthotopic) models of uterine cancer. PDGFRα was highly expressed and activated in uterine cancer samples and cell lines. Treatment with 3G3 resulted in substantial inhibition of PDGFRα phosphorylation and of downstream signaling molecules AKT and mitogen-activated protein kinase (MAPK). Cell viability and invasive potential of uterine cancer cells were also inhibited by 3G3 treatment. In orthotopic mouse models of uterine cancer, 3G3 monotherapy had significant antitumor effects in the PDGFRα-positive models (Hec-1A, Ishikawa, Spec-2) but not in the PDGFRα-negative model (OVCA432). Greater therapeutic effects were observed for 3G3 in combination with chemotherapy than for either drug alone in the PDGFRα-positive models. The antitumor effects of therapy were related to increased apoptosis and decreased proliferation and angiogenesis. These findings identify PDGFRα as an attractive target for therapeutic development in uterine cancer. ©2014 American Association for Cancer Research.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2005-09-01

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

  15. Significance of Phosphorylated Epidermal Growth Factor Receptor and Its Signal Transducers in Human Soft Tissue Sarcoma

    Directory of Open Access Journals (Sweden)

    Jia-Lin Yang

    2017-05-01

    Full Text Available Previous studies have shown that total epidermal growth factor receptor (EGFR protein is highly expressed in soft tissue sarcoma (STS. We aimed to investigate the significance of phosphorylated-EGFR (pEGFR and its activated-downstream signal transducers in STS tissue samples. A tissue microarray comprising 87 STS samples was assessed for total EGFR, pEGFR and its phosphorylated signal transducers and expression was correlated with clinicopathlogical parameters including patient outcome. Although the expression of total EGFR was significantly associated with adverse STS histologic grade (p = 0.004 and clinical stage (p = 0.012 similar to pEGFR, phosphorylated protein kinase B (pAkt and phosphorylated extracellular signal regulated kinase (pERK, it is not a prognostic factor for survival. By contrast, the expression of pEGFR is an independent factor for cancer specific survival, while pERK is an independent prognostic factor for both overall and cancer specific survival in STS (p < 0.05, Cox proportional hazard model and log-rank test in addition to the recognised factors of tumour grade and clinical stage. pERK and pEGFR are new independent prognostic factors for overall and/or cancer specific survival in STS. The expression of EGFR/pEGFR, and their associated downstream signal transducers, was associated with STS progression, suggesting that EGFR downstream signalling pathways may jointly support STS cell survival.

  16. A novel monoclonal antibody targeting coxsackie virus and adenovirus receptor inhibits tumor growth in vivo.

    Science.gov (United States)

    Kawada, Manabu; Inoue, Hiroyuki; Kajikawa, Masunori; Sugiura, Masahito; Sakamoto, Shuichi; Urano, Sakiko; Karasawa, Chigusa; Usami, Ihomi; Futakuchi, Mitsuru; Masuda, Tohru

    2017-01-11

    To create a new anti-tumor antibody, we conducted signal sequence trap by retrovirus-meditated expression method and identified coxsackie virus and adenovirus receptor (CXADR) as an appropriate target. We developed monoclonal antibodies against human CXADR and found that one antibody (6G10A) significantly inhibited the growth of subcutaneous as well as orthotopic xenografts of human prostate cancer cells in vivo. Furthermore, 6G10A also inhibited other cancer xenografts expressing CXADR, such as pancreatic and colorectal cancer cells. Knockdown and overexpression of CXADR confirmed the dependence of its anti-tumor activity on CXADR expression. Our studies of its action demonstrated that 6G10A exerted its anti-tumor activity primarily through both antibody-dependent cellular cytotoxicity and complement-dependent cytotoxicity. Moreover, 6G10A reacted with human tumor tissues, such as prostate, lung, and brain, each of which express CXADR. Although we need further evaluation of its reactivity and safety in human tissues, our results show that a novel anti-CXADR antibody may be a feasible candidate for cancer immunotherapy.

  17. Seminal Plasma Proteins as Androgen Receptor Corregulators Promote Prostate Cancer Growth

    Science.gov (United States)

    2016-12-01

    that SgI did not interact with other steroid hormone receptors, including estrogen receptors and glucocorticoid receptor, and did not significantly...estrogen receptor-β, or glucocorticoid receptor. Figure 6. Co-precipitation of AR and SgI. Cell lysates from 293T transfected with pSG5-AR and pSG5-SgI...results suggest that SgI may require not only zinc, as in the case of its physi- ological action [12-16], but also AR to function as a modulator of

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

    DEFF Research Database (Denmark)

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

    1999-01-01

    role for eps15 in receptor-mediated endocytosis. In this study we show that, upon activation of the EGFR kinase, eps15 undergoes dramatic relocalization consisting of 1) initial relocalization to the plasma membrane and 2) subsequent colocalization with the EGFR in various intracellular compartments......Eps15 is a substrate for the tyrosine kinase of the epidermal growth factor receptor (EGFR) and is characterized by the presence of a novel protein:protein interaction domain, the EH domain. Eps15 also stably binds the clathrin adaptor protein complex AP-2. Previous work demonstrated an essential......, suggesting sustained phosphorylation in endocytic compartments. Our results are consistent with a model in which eps15 undergoes cycles of association:dissociation with membranes and suggest multiple roles for this protein in the endocytic pathway....

  19. Experimental diabetes increases insulin-like growth factor I and II receptor concentration and gene expression in kidney

    International Nuclear Information System (INIS)

    Werner, H.; Shen-Orr, Z.; Stannard, B.; Burguera, B.; Roberts, C.T. Jr.; LeRoith, D.

    1990-01-01

    Insulinlike growth factor I (IGF-I) is a mitogenic hormone with important regulatory roles in growth and development. One of the target organs for IGF-I action is the kidney, which synthesizes abundant IGF-I receptors and IGF-I itself. To study the involvement of IGF-I and the IGF-I receptor in the development of nephropathy, one of the major complications of diabetes mellitus, we measured the expression of these genes in the kidney and in other tissues of the streptozocin-induced diabetic rat. The binding of 125I-labeled IGF-I to crude membranes was measured in the same tissues. We observed a 2.5-fold increase in the steady-state level of IGF-I-receptor mRNA in the diabetic kidney, which was accompanied by a 2.3-fold increase in IGF-I binding. In addition to this increase in IGF-I binding to the IGF-I receptor, there was also binding to a lower-molecular-weight material that may represent an IGF-binding protein. No change was detected in the level of IGF-I-peptide mRNA. Similarly, IGF-II-receptor mRNA levels and IGF-II binding were significantly increased in the diabetic kidney. IGF-I- and IGF-II-receptor mRNA levels and IGF-I and IGF-II binding returned to control values after insulin treatment. Because the IGF-I receptor is able to transduce mitogenic signals on activation of its tyrosine kinase domain, we hypothesize that, among other factors, high levels of receptor in the diabetic kidney may also be involved in the development of diabetic nephropathy. Increased IGF-II-receptor expression in the diabetic kidney may be important for the intracellular transport and packaging of lysosomal enzymes, although a role for this receptor in signal transduction cannot be excluded. Finally, the possible role of IGF-binding proteins requires further study

  20. Pleiotropic Stromal Effects of Vascular Endothelial Growth Factor Receptor 2 Antibody Therapy in Renal Cell Carcinoma Models

    Directory of Open Access Journals (Sweden)

    Inga J. Duignan

    2011-01-01

    Full Text Available The benefits of inhibiting vascular endothelial growth factor (VEGF signaling in cancer patients are predominantly attributed to effects on tumor endothelial cells. Targeting non–endothelial stromal cells to further impact tumor cell growth and survival is being pursued through the inhibition of additional growth factor pathways important for the survival and/or proliferation of these cells. However, recent data suggest that VEGF receptor (VEGFR–specific inhibitors may target lymphatic vessels and pericytes in addition to blood vessels. Here, in fact, we demonstrate that DC101 (40 mg/kg, thrice a week, an antibody specific to murine VEGFR2, significantly reduces all three of these stromal components in subcutaneous (SKRC-29 and orthotopic (786-O-LP models of renal cell carcinoma (RCC established in nu/nu athymic mice. Sunitinib (40 mg/kg, once daily, a receptor tyrosine kinase inhibitor of VEGFR2 and other growth factor receptors, also caused significant loss of tumor blood vessels in RCC models but had weaker effects than DC101 on pericytes and lymphatic vessels. In combination, sunitinib did not significantly add to the effects of DC101 on tumor blood vessels, lymphatic vessels, or pericytes. Nevertheless, sunitinib increased the effect of DC101 on tumor burden in the SKRC-29 model, perhaps related to its broader specificity. Our data have important implications for combination therapy design, supporting the conclusion that targeting VEGFR2 alone in RCC has the potential to have pleiotropic effects on tumor stroma.

  1. Pleiotropic Stromal Effects of Vascular Endothelial Growth Factor Receptor 2 Antibody Therapy in Renal Cell Carcinoma Models1

    Science.gov (United States)

    Duignan, Inga J; Corcoran, Erik; Pennello, Anthony; Plym, Mary Jane; Amatulli, Michael; Claros, Nidia; Iacolina, Michelle; Youssoufian, Hagop; Witte, Larry; Samakoglu, Selda; Schwartz, Jonathan; Surguladze, David; Tonra, James R

    2011-01-01

    The benefits of inhibiting vascular endothelial growth factor (VEGF) signaling in cancer patients are predominantly attributed to effects on tumor endothelial cells. Targeting non-endothelial stromal cells to further impact tumor cell growth and survival is being pursued through the inhibition of additional growth factor pathways important for the survival and/or proliferation of these cells. However, recent data suggest that VEGF receptor (VEGFR)-specific inhibitors may target lymphatic vessels and pericytes in addition to blood vessels. Here, in fact, we demonstrate that DC101 (40 mg/kg, thrice a week), an antibody specific to murine VEGFR2, significantly reduces all three of these stromal components in subcutaneous (SKRC-29) and orthotopic (786-O-LP) models of renal cell carcinoma (RCC) established in nu/nu athymic mice. Sunitinib (40 mg/kg, once daily), a receptor tyrosine kinase inhibitor of VEGFR2 and other growth factor receptors, also caused significant loss of tumor blood vessels in RCC models but had weaker effects than DC101 on pericytes and lymphatic vessels. In combination, sunitinib did not significantly add to the effects of DC101 on tumor blood vessels, lymphatic vessels, or pericytes. Nevertheless, sunitinib increased the effect of DC101 on tumor burden in the SKRC-29 model, perhaps related to its broader specificity. Our data have important implications for combination therapy design, supporting the conclusion that targeting VEGFR2 alone in RCC has the potential to have pleiotropic effects on tumor stroma. PMID:21245940

  2. Andrographolide inhibits growth of acute promyelocytic leukaemia cells by inducing retinoic acid receptor-independent cell differentiation and apoptosis.

    Science.gov (United States)

    Manikam, Shiamala D; Manikam, Shiamala T; Stanslas, Johnson

    2009-01-01

    The growth inhibiting potential of andrographolide was evaluated in three acute promyelocytic leukaemia cell line models (HL-60, NB4 and all-trans retinoic acid (ATRA)-resistant NB4-R2). In elucidating the mechanisms of growth inhibition, a special emphasis was placed on assessing the induction of differentiation and apoptosis by andrographolide in the primary acute promyelocytic leukaemia NB4 cells. The compound was 2- and 3-fold more active in inhibiting the growth of HL-60 and NB4-R2 cells compared with NB4 cells, respectively. At IC50 (concentration at which growth of 50% of the cells (compared with medium only treated control cells) is inhibited; 4.5 microM) the compound exhibited strong cell-differentiating activity in NB4 cells, similar to ATRA (IC50 1.5 microM). In the presence of a pure retinoic acid receptor antagonist AGN193109, the growth inhibition of NB4 cells by ATRA was reversed, whereas the activity of andrographolide was not affected. This clearly suggested that andrographolide's cell differentiating activity to induce growth inhibition of NB4 cells most likely occurred via a retinoic acid receptor-independent pathway. At higher concentration (2xIC50), andrographolide was an efficient inducer of apoptosis in NB4 cells. Taken together, these results suggest andrographolide and its derivatives, apparently with a novel cell differentiating mechanism and with ability to induce apoptosis, might be beneficial in the treatment of primary and ATRA-resistant acute promyelocytic leukaemia.

  3. Internalization and down-regulation of the human epidermal growth factor receptor are regulated by the carboxyl-terminal tyrosines

    DEFF Research Database (Denmark)

    Helin, K; Beguinot, L

    1991-01-01

    The C terminus of the epidermal growth factor receptor (EGF-R) contains three tyrosines (Y1068, Y1148, and Y1173) which correspond to the major autophosphorylation sites. To investigate the role of the tyrosines in internalization and down-regulation of the EGF-R, mutational analysis was performed......-R in response to EGF showing a half-life of about 1 h. Degradation of the triple point mutant, however, was impaired and resulted in a half-life of 4 h in the presence of EGF. EGF-dependent down-regulation of surface receptors was decreased in the triple point mutant EGF-R as was internalization and degradation...... of EGF. The specific rate of internalization of the triple point mutant was reduced. By contrast, intracellular processing of ligand previously internalized at 20 degrees C was similar between wild type and mutant receptors. Taken together the data indicate that the delay in degradation observed in cells...

  4. Screening of the transcriptional regulatory regions of vascular endothelial growth factor receptor 2 (VEGFR2 in amyotrophic lateral sclerosis

    Directory of Open Access Journals (Sweden)

    Hartley Judith

    2007-04-01

    Full Text Available Abstract Background Vascular endothelial growth factor (VEGF has neurotrophic activity which is mediated by its main agonist receptor, VEGFR2. Dysregulation of VEGF causes motor neurone degeneration in a mouse model of amyotrophic lateral sclerosis (ALS, and expression of VEGFR2 is reduced in motor neurones and spinal cord of patients with ALS. Methods We have screened the promoter region and 4 exonic regions of functional significance of the VEGFR2 gene in a UK population of patients with ALS, for mutations and polymorphisms that may affect expression or function of this VEGF receptor. Results No mutations were identified in the VEGFR2 gene. We found no association between polymorphisms in the regulatory regions of the VEGFR2 gene and ALS. Conclusion Mechanisms other than genetic variation may downregulate expression or function of the VEGFR2 receptor in patients with ALS.

  5. The expression of receptors for estrogen and epithelial growth factor in the male rabbit prostate and prostatic urethra following castration

    DEFF Research Database (Denmark)

    Bødker, A; Balslev, E; Iversen, H G

    1997-01-01

    In the lower urinary tract of the male rabbit, estrogen receptors (ERs) are restricted to the urethra and the prostatic stroma. At present, the function of ERs in these tissues is not known. Epithelial growth factor (EGF) stimulates proliferation of epidermal and epithelial tissues, and several...... were included as controls. In the control group, ERs were found in the urothelial lining and lamina propria of the prostatic urethra, and in the prostatic stroma. EGF receptors were demonstrated in the epithelial lining of the prostatic urethra and the glandular epithelium of the prostate. Following...... castration, the expression of ERs, assessed as the increase in the number of positively stained specimens, increased significantly in the lamina propria of the prostatic urethra and the prostatic stroma. EGF receptor expression increased significantly in the epithelial lining of the prostatic urethra...

  6. GnRH receptor activation competes at a low level with growth signaling in stably transfected human breast cell lines

    International Nuclear Information System (INIS)

    Morgan, Kevin; Meyer, Colette; Miller, Nicola; Sims, Andrew H; Cagnan, Ilgin; Faratian, Dana; Harrison, David J; Millar, Robert P; Langdon, Simon P

    2011-01-01

    Gonadotrophin releasing hormone (GnRH) analogs lower estrogen levels in pre-menopausal breast cancer patients. GnRH receptor (GnRH-R) activation also directly inhibits the growth of certain cells. The applicability of GnRH anti-proliferation to breast cancer was therefore analyzed. GnRH-R expression in 298 primary breast cancer samples was measured by quantitative immunofluorescence. Levels of functional GnRH-R in breast-derived cell lines were assessed using 125 I-ligand binding and stimulation of 3 H-inositol phosphate production. Elevated levels of GnRH-R were stably expressed in cells by transfection. Effects of receptor activation on in vitro cell growth were investigated in comparison with IGF-I and EGF receptor inhibition, and correlated with intracellular signaling using western blotting. GnRH-R immunoscoring was highest in hormone receptor (triple) negative and grade 3 breast tumors. However prior to transfection, functional endogenous GnRH-R were undetectable in four commonly studied breast cancer cell lines (MCF-7, ZR-75-1, T47D and MDA-MB-231). After transfection with GnRH-R, high levels of cell surface GnRH-R were detected in SVCT and MDA-MB-231 clones while low-moderate levels of GnRH-R occurred in MCF-7 clones and ZR-75-1 clones. MCF-7 sub-clones with high levels of GnRH-R were isolated following hygromycin phosphotransferase transfection. High level cell surface GnRH-R enabled induction of high levels of 3 H-inositol phosphate and modest growth-inhibition in SVCT cells. In contrast, growth of MCF-7, ZR-75-1 or MDA-MB-231 clones was unaffected by GnRH-R activation. Cell growth was inhibited by IGF-I or EGF receptor inhibitors. IGF-I receptor inhibitor lowered levels of p-ERK1/2 in MCF-7 clones. Washout of IGF-I receptor inhibitor resulted in transient hyper-elevation of p-ERK1/2, but co-addition of GnRH-R agonist did not alter the dynamics of ERK1/2 re-phosphorylation. Breast cancers exhibit a range of GnRH-R immunostaining, with higher levels of

  7. Sphingosine-1-Phosphate Receptor-1 Selective Agonist Enhances Collateral Growth and Protects against Subsequent Stroke.

    Directory of Open Access Journals (Sweden)

    Masahiko Ichijo

    Full Text Available Collateral growth after acute occlusion of an intracranial artery is triggered by increasing shear stress in preexisting collateral pathways. Recently, sphingosine-1-phosphate receptor-1 (S1PR1 on endothelial cells was reported to be essential in sensing fluid shear stress. Here, we evaluated the expression of S1PR1 in the hypoperfused mouse brain and investigated the effect of a selective S1PR1 agonist on leptomeningeal collateral growth and subsequent ischemic damage after focal ischemia.In C57Bl/6 mice (n = 133 subjected to unilateral common carotid occlusion (CCAO and sham surgery. The first series examined the time course of collateral growth, cell proliferation, and S1PR1 expression in the leptomeningeal arteries after CCAO. The second series examined the relationship between pharmacological regulation of S1PR1 and collateral growth of leptomeningeal anastomoses. Animals were randomly assigned to one of the following groups: LtCCAO and daily intraperitoneal (i.p. injection for 7 days of an S1PR1 selective agonist (SEW2871, 5 mg/kg/day; sham surgery and daily i.p. injection for 7 days of SEW2871 after surgery; LtCCAO and daily i.p. injection for 7 days of SEW2871 and an S1PR1 inverse agonist (VPC23019, 0.5 mg/kg; LtCCAO and daily i.p. injection of DMSO for 7 days after surgery; and sham surgery and daily i.p. injection of DMSO for 7 days. Leptomeningeal anastomoses were visualized 14 days after LtCCAO by latex perfusion method, and a set of animals underwent subsequent permanent middle cerebral artery occlusion (pMCAO 7 days after the treatment termination. Neurological functions 1 hour, 1, 4, and 7 days and infarction volume 7 days after pMCAO were evaluated.In parallel with the increase in S1PR1 mRNA levels, S1PR1 expression colocalized with endothelial cell markers in the leptomeningeal arteries, increased markedly on the side of the CCAO, and peaked 7 days after CCAO. Mitotic cell numbers in the leptomeningeal arteries increased after

  8. Quantitative assessment of fibroblast growth factor receptor 1 expression in neurons and glia

    Directory of Open Access Journals (Sweden)

    Lisha Choubey

    2017-04-01

    Full Text Available Background Fibroblast growth factors (FGFs and their receptors (FGFRs have numerous functions in the developing and adult central nervous system (CNS. For example, the FGFR1 receptor is important for proliferation and fate specification of radial glial cells in the cortex and hippocampus, oligodendrocyte proliferation and regeneration, midline glia morphology and soma translocation, Bergmann glia morphology, and cerebellar morphogenesis. In addition, FGFR1 signaling in astrocytes is required for postnatal maturation of interneurons expressing parvalbumin (PV. FGFR1 is implicated in synapse formation in the hippocampus, and alterations in the expression of Fgfr1 and its ligand, Fgf2 accompany major depression. Understanding which cell types express Fgfr1 during development may elucidate its roles in normal development of the brain as well as illuminate possible causes of certain neuropsychiatric disorders. Methods Here, we used a BAC transgenic reporter line to trace Fgfr1 expression in the developing postnatal murine CNS. The specific transgenic line employed was created by the GENSAT project, tgFGFR1-EGFPGP338Gsat, and includes a gene encoding enhanced green fluorescent protein (EGFP under the regulation of the Fgfr1 promoter, to trace Fgfr1 expression in the developing CNS. Unbiased stereological counts were performed for several cell types in the cortex and hippocampus. Results This model reveals that Fgfr1 is primarily expressed in glial cells, in both astrocytes and oligodendrocytes, along with some neurons. Dual labeling experiments indicate that the proportion of GFP+ (Fgfr1+ cells that are also GFAP+ increases from postnatal day 7 (P7 to 1 month, illuminating dynamic changes in Fgfr1 expression during postnatal development of the cortex. In postnatal neurogenic areas, GFP expression was also observed in SOX2, doublecortin (DCX, and brain lipid-binding protein (BLBP expressing cells. Fgfr1 is also highly expressed in DCX positive cells of

  9. Alterations in epidermal growth factor receptors 1 and 2 in esophageal squamous cell carcinomas

    Directory of Open Access Journals (Sweden)

    Gonzaga Isabela Martins

    2012-12-01

    Full Text Available Abstract Background Esophageal squamous cell carcinoma (ESCC shows a 5-year survival rate below 10%, demonstrating the urgency in improving its treatment. Alterations in epidermal growth factor receptors are closely related to malignancy transformation in a number of tumors and recent successful targeted therapies have been directed to these molecules. Therefore, in this study, we analyzed the expression of EGFR and HER2 and evaluated EGFR mutation profile as well as the presence of mutations in hotspots of KRAS and BRAF in ESCC patients. Methods We performed RT-qPCR, immunohistochemistry and Fluorescent in situ hybridization to determine EGFR and HER2 expression in ESCC patients, and direct sequencing and PCR-RFLP for mutations and polymorphism analysis. Results Our results showed an increased EGFR mRNA expression in tumors compared to surrounding tissue (p HER2 mRNA was not different between tumors and adjacent mucosa. Still, 7% of the tumors presented at least a 25-fold higher expression of this gene when compared to its paired counterpart. Immunohistochemical analysis revealed that 21% of the tumors were positive for HER2 (scores 2+ and 3+, although only 3+ tumors presented amplification of this gene. Mutation analysis for EGFR (exons 18-21, KRAS (codons 12 and 13 and BRAF (V600E showed no mutations in any of the hotspots of these genes in almost 100 patients analyzed. EGFR presented synonymous polymorphisms at codon 836 (C>T in 2.1% of the patients, and at codon 787 (G>A in 79.2% of the cases. This last polymorphism was also evaluated in 304 healthy controls, which presented a similar frequency (73.7% in comparison with ESCC patients. The absence of mutations of EGFR, KRAS and BRAF as well as the overexpression of EGFR and HER2 in less than 10% of the patients suggest that this signaling pathway is altered in only a small proportion of patients with ESCC. Conclusion HER receptors target therapies may have the potential to be effective in

  10. Transforming growth factor-betas and their signaling receptors are coexpressed in Crohn's disease.

    Science.gov (United States)

    di Mola, F F; Friess, H; Scheuren, A; Di Sebastiano, P; Graber, H; Egger, B; Zimmermann, A; Korc, M; Büchler, M W

    1999-01-01

    To evaluate mechanisms that contribute to tissue repair and tissue remodeling in Crohn's disease (CD). Transforming growth factor-betas (TGF-betas) are involved in different chronic inflammatory disorders. They function by binding to two receptors, type I (TbetaR-I) subtype ALK5 and type II (TbetaR-II), which are concomitantly required for signal transduction. Tissues were obtained from 18 patients with CD (10 female patients, 8 male patients, median age 38.7 years [range 16 to 58 years]) undergoing surgery because of CD-related complications. Tissue samples of 18 healthy organ donors (10 female subjects, 8 male subjects, median age 50.3 years [range 15 to 65 years]) served as controls. The expression and localization of TGF-beta1, TGF-beta2, TGF-beta3, TbetaR-IALK5, TbetaR-II, and TbetaR-III were studied by Northern blot analysis, in situ hybridization, and immunohistochemistry. On Northern blot analysis, 94% of the CD samples exhibited enhanced TGF-beta1, TGF-beta3, and TbetaR-II mRNA expression compared with controls. TGF-beta2 was increased in 72%, TbetaR-IALK5 in 72%, and TbetaR-III in 82% of the patients with CD. On in situ hybridization and immunohistochemical analysis, TGF-beta1, TbetaR-IALK5, and TbetaR-II were seen to be colocalized in the lamina propria cells and in the lymphocytes closest to the luminal surface, but also in the remaining epithelial cells, and in fibroblasts of CD tissue samples. The concomitant overexpression of TGF-betas and their signaling receptors in CD points to a potential role of these regulatory molecules in the pathophysiology of CD. Activation of TGF-beta-mediated pathways might promote the repair of mucosal injury by enhancing the process of reepithelization, but might also contribute to extracellular matrix generation and subsequently to intramural fibrosis and intestinal obstruction.

  11. Differential expression of growth factor receptors and membrane-bound tumor markers for imaging in male and female breast cancer.

    Directory of Open Access Journals (Sweden)

    Jeroen F Vermeulen

    Full Text Available INTRODUCTION: Male breast cancer accounts for 0.5-1% of all breast cancers and is generally diagnosed at higher stage than female breast cancers and therefore might benefit from earlier detection and targeted therapy. Except for HER2 and EGFR, little is known about expression of growth factor receptors in male breast cancer. We therefore investigated expression profiles of growth factor receptors and membrane-bound tumor markers in male breast cancer and gynecomastia, in comparison with female breast cancer. METHODS: Tissue microarrays containing 133 male breast cancer and 32 gynecomastia cases were stained by immunohistochemistry for a panel of membrane-bound targets and compared with data on 266 female breast cancers. RESULTS: Growth factor receptors were variably expressed in 4.5% (MET up to 38.5% (IGF1-R of male breast cancers. Compared to female breast cancer, IGF1-R and carbonic anhydrase 12 (CAXII were more frequently and CD44v6, MET and FGFR2 less frequently expressed in male breast cancer. Expression of EGFR, HER2, CAIX, and GLUT1 was not significantly different between male and female breast cancer. Further, 48.1% of male breast cancers expressed at least one and 18.0% expressed multiple growth factor receptors. Since individual membrane receptors are expressed in only half of male breast cancers, a panel of membrane markers will be required for molecular imaging strategies to reach sensitivity. A potential panel of markers for molecular imaging, consisting of EGFR, IGF1-R, FGFR2, CD44v6, CAXII, GLUT1, and CD44v6 was positive in 77% of male breast cancers, comparable to female breast cancers. CONCLUSIONS: Expression patterns of growth factor receptors and hypoxia membrane proteins in male breast cancer are different from female breast cancer. For molecular imaging strategies, a putative panel consisting of markers for EGFR, IGF1-R, FGFR2, GLUT1, CAXII, CD44v6 was positive in 77% of cases and might be considered for development of

  12. 20-Aminosteroids as a novel class of selective and complete androgen receptor antagonists and inhibitors of prostate cancer cell growth.

    Science.gov (United States)

    Fousteris, Manolis A; Schubert, Undine; Roell, Daniela; Roediger, Julia; Bailis, Nikolaos; Nikolaropoulos, Sotiris S; Baniahmad, Aria; Giannis, Athanassios

    2010-10-01

    Here, the synthesis and the evaluation of novel 20-aminosteroids on androgen receptor (AR) activity is reported. Compounds 11 and 18 of the series inhibit both the wild type and the T877A mutant AR-mediated transactivation indicating AR antagonistic function. Interestingly, minor structural changes such as stereoisomers of the amino lactame moiety exhibit preferences for antagonism among wild type and mutant AR. Other tested nuclear receptors are only weakly or not affected. In line with this, the prostate cancer cell growth of androgen-dependent but not of cancer cells lacking expression of the AR is inhibited. Further, the expression of the prostate specific antigen used as a diagnostic marker is also repressed. Finally steroid 18 enhances cellular senescence that might explain in part the growth inhibition mediated by this derivative. Steroids 11 and 18 are the first steroids that act as complete AR antagonists and exhibit AR specificity. Copyright © 2010 Elsevier Ltd. All rights reserved.

  13. Neutralization of IL-8 prevents the induction of dermatologic adverse events associated with the inhibition of epidermal growth factor receptor

    DEFF Research Database (Denmark)

    Bangsgaard, Nannie; Houtkamp, Mischa; Schuurhuis, Danita H

    2012-01-01

    Epidermal growth factor receptor (EGFR) inhibitors are widely used in the treatment of cancer. EGFR-targeted treatment is known to be associated with a high incidence of dermatological adverse reactions, including papulopustular rash, which can be dose-limiting and may affect compliance to treatm......Epidermal growth factor receptor (EGFR) inhibitors are widely used in the treatment of cancer. EGFR-targeted treatment is known to be associated with a high incidence of dermatological adverse reactions, including papulopustular rash, which can be dose-limiting and may affect compliance...... repeat dose treatment with HuMab-10F8, a neutralizing human antibody against IL-8, reduced the rash. Inhibition of IL-8 can therefore ameliorate dermatological adverse events induced by treatment with EGFR inhibitors....

  14. Co-ordinate regulation of growth factor receptors and lipid phosphate phosphatase-1 controls cell activation by exogenous lysophosphatidate.

    Science.gov (United States)

    Pilquil, C; Ling, Z C; Singh, I; Buri, K; Zhang, Q X; Brindley, D N

    2001-11-01

    The serum-derived lipid growth factors, lysophosphatidate (LPA) and sphingosine 1-phosphate (S1P), activate cells selectively through different members of a family of endothelial differentiation gene (EDG) receptors. Activation of EDG receptors by LPA and S1P provides a variety of signalling cascades depending upon the G-protein coupling of the different EDG receptors. This leads to chemotactic and mitogenic responses, which are important in wound healing. For example, LPA stimulates fibroblast division and S1P stimulates the chemotaxis and division of endothelial cells leading to angiogenesis. Counteracting these effects of LPA and S1P, are the actions of lipid phosphate phosphatases (LPP, or phosphatidate phosphohydrolases, Type 2). The isoform LPP-1 is expressed in the plasma membrane with its active site outside the cell. This enzyme is responsible for 'ecto-phosphatase' activity leading to the degradation of exogenous lipid phosphate mediators, particularly LPA. Expression of LPP-1 decreases cell activation by exogenous LPA. The mechanism for this is controversial and several mechanisms have been proposed. Evidence will be presented that the LPPs cross-talk with EDG and other growth factor receptors, thus, regulating the responses of the cells to lipid phosphate mediators of signal transduction.

  15. Analysis of the epidermal growth factor receptor specific transcriptome: effect of receptor expression level and an activating mutation

    DEFF Research Database (Denmark)

    Pedersen, Mikkel W; Pedersen, Nina; Damstrup, Lars

    2005-01-01

    moderately expressed or overexpressed at an in-itself transforming level. These changes were compared to those induced by the naturally occurring constitutively active variant EGFRvIII. This study provides novel insight on the activities and mechanisms of EGFRvIII and EGFR mediated transformation, as genes...... by interferons. Expression of this module was absent in the EGFRvIII-expressing cell line and the parental cell line. Treatment with the specific EGFR inhibitor AG1478 indicated that the regulations were primary, receptor-mediated events. Furthermore, activation of this module correlated with activation of STAT1...

  16. Phosphorylated hepatocyte growth factor receptor/c-Met is associated with tumor growth and prognosis in patients with bladder cancer: correlation with matrix metalloproteinase-2 and -7 and E-cadherin.

    Science.gov (United States)

    Miyata, Yasuyoshi; Sagara, Yuji; Kanda, Shigeru; Hayashi, Tomayoshi; Kanetake, Hiroshi

    2009-04-01

    Hepatocyte growth factor receptor/c-Met is associated with malignant aggressiveness and survival in various cancers including bladder cancer. Although phosphorylation of hepatocyte growth factor receptor/c-Met is essential for its function, the pathologic significance of phosphorylated hepatocyte growth factor receptor/c-Met in bladder cancer remains elusive. We investigated the clinical significance of its expression, and its correlation with cancer cell progression-related molecules. The expression levels of 2 tyrosine residues of hepatocyte growth factor receptor/c-Met (pY1234/1235 and pY1349) were examined immunohistochemically in 133 specimens with nonmetastatic bladder cancer. We also investigated their correlation with matrix metalloproteinase-1, -2, -7, and -14; urokinase-type plasminogen activator; E-cadherin; CD44 standard, variant 3, and variant 6; and vascular endothelial growth factor. Expression of phosphorylated hepatocyte growth factor receptor/c-Met was detected in cancer cells, but was rare in normal urothelial cells. Although hepatocyte growth factor receptor/c-Met, pY1234/1235 hepatocyte growth factor receptor/c-Met, and pY1349 hepatocyte growth factor receptor/c-Met were associated with pT stage, multivariate analysis identified pY1349 hepatocyte growth factor receptor/c-met expression only as a significant factor for high pT stage. Expression of pY1349 hepatocyte growth factor receptor/c-Met was a marker of metastasis and (P = .001) and cause-specific survival (P = .003). Expressions of matrix metalloproteinase-2, matrix metalloproteinase-7, and E-cadherin correlated with pY1349 hepatocyte growth factor receptor/c-Met expression. Our results demonstrated that pY1349 hepatocyte growth factor receptor/c-Met plays an important role in tumor development, and its expression is a significant predictor of metastasis and survival of patients with bladder cancer. The results suggest that these activities are mediated, at least in part, by matrix

  17. Association between the Growth Hormone Receptor Exon 3 Polymorphism and Metabolic Factors in Korean Patients with Acromegaly

    OpenAIRE

    Park, Hye Yoon; Hwang, In Ryang; Seo, Jung Bum; Kim, Su Won; Seo, Hyun Ae; Lee, In Kyu; Kim, Jung Guk

    2015-01-01

    Background This study investigated the association between the frequency of growth hormone receptor (GHR) exon 3 polymorphism (exon 3 deletion; d3-GHR) and metabolic factors in patients with acromegaly in Korea. Methods DNA was extracted from the peripheral blood of 30 unrelated patients with acromegaly. GHR genotypes were evaluated by polymerase chain reaction and correlated with demographic data and laboratory parameters. Results No patient had the d3/d3 genotype, while four (13.3%) had the...

  18. Epidermal growth factor receptor (EGFR) mutations in non-small cell lung cancer (NSCLC) of Yunnan in southwestern China

    OpenAIRE

    Zhou, Yongchun; Yang, Yanlong; Yang, Chenggang; Chen, Yunlan; Yang, Changshao; Du, Yaxi; Zhao, Guangqiang; Ye, Lianhua; Huang, Yunchao

    2017-01-01

    To investigate the Epidermal Growth Factor Receptor (EGFR) mutation status in non-small cell lung cancer (NSCLC) in Yunnan province in southwestern China, we detected EGFR mutation by Amplification Refractory Mutation System (ARMS) polymerase chain reaction (PCR) using DNA samples from 447 pathologically confirmed NSCLC specimens (175 tissue, 256 plasma and 16 cytologic samples). The relationship between EGFR mutations and demographic and clinical factors were further explored. Subgroup analy...

  19. Immunogenicity and safety of xenogeneic vascular endothelial growth factor receptor-2 DNA vaccination in mice and dogs

    OpenAIRE

    Denies, Sofie; Cicchelero, Laetitia; Polis, Ingeborgh; Sanders, Niek N.

    2016-01-01

    Vascular endothelial growth factor receptor-2 (VEGFR-2) is an attractive target in oncology due to its crucial role in angiogenesis. In this study a DNA vaccine coding for human VEGFR-2 was evaluated in healthy mice and dogs, administered by intradermal injection and electroporation. In mice, three doses and vaccination schedules were evaluated. Cellular immune responses were measured by intracellular IFN-gamma staining and a cytotoxicity assay and antibodies by ELISA. Safety was assessed by ...

  20. Significance of epidermal growth factor receptor signaling for acquisition of meiotic and developmental competence in mammalian oocytes

    Czech Academy of Sciences Publication Activity Database

    Procházka, Radek; Blaha, Milan; Němcová, Lucie

    2017-01-01

    Roč. 97, č. 4 (2017), s. 537-549 ISSN 0006-3363 R&D Projects: GA MZe(CZ) QJ1510138; GA MŠk EF15_003/0000460 Institutional support: RVO:67985904 Keywords : amphiregulin * cumulus cells * epidermal growth factor receptor Subject RIV: EB - Genetics ; Molecular Biology OBOR OECD: Reproductive biology (medical aspects to be 3) Impact factor: 3.432, year: 2016

  1. Chimeric Monoclonal Antibody Cetuximab Targeting Epidermal Growth Factor-Receptor in Advanced Non-Melanoma Skin Cancer

    OpenAIRE

    Uwe Wollina; Georgi Tchernev; Torello Lotti

    2017-01-01

    BACKGROUND: Non-melanoma skin cancer (NMSC) is the most common malignancy in humans. Targeted therapy with monoclonal antibody cetuximab is an option in case of advanced tumor or metastasis. AIM: We present and update of the use of cetuximab in NMSC searching PUBMED 2011-2017. METHODS: The monoclonal antibody cetuximab against epidermal growth factor receptor (EGFR) has been investigated for its use in NMSC during the years 2011 to 2017 by a PUBMED research using the following items: ...

  2. Epidermal growth factor-receptor interaction in rat pheochromocytoma (PC12) and human epidermoid A431 cells: Biochemical and ultrastructural studies

    NARCIS (Netherlands)

    Laat, S.W. de; Boonstra, J.; Mummery, C.L.; Defize, L.; Leunissen, J.; Verkleij, A.J.

    1984-01-01

    Pheochromocytoma cells (clone PC12) have specific plasmamembrane receptors for both epidermal growth factor (EGF) and nerve growth factor (NGF). These growth factors have however, opposite biological effects in PC12 cells; EGF acts mitogenically, while NGF induces differentiation and causes

  3. α5-GABAA receptors negatively regulate MYC-amplified medulloblastoma growth

    OpenAIRE

    Sengupta, Soma; Weeraratne, Shyamal Dilhan; Sun, Hongyu; Phallen, Jillian; Rallapalli, Sundari K.; Teider, Natalia; Kosaras, Bela; Amani, Vladimir; Pierre-Francois, Jessica; Tang, Yujie; Nguyen, Brian; Yu, Furong; Schubert, Simone; Balansay, Brianna; Mathios, Dimitris

    2013-01-01

    Neural tumors often express neurotransmitter receptors as markers of their developmental lineage. Although these receptors have been well characterized in electrophysiological, developmental and pharmacological settings, their importance in the maintenance and progression of brain tumors, and importantly, the effect of their targeting in brain cancers remains obscure. Here, we demonstrate high levels of GABR5, which encodes the α-subunit of the GABAA receptor complex, in aggressive MYC-driven...

  4. Receptor-like kinases as surface regulators for RAC/ROP-mediated pollen tube growth and interaction with the pistil

    Science.gov (United States)

    Zou, Yanjiao; Aggarwal, Mini; Zheng, Wen-Guang; Wu, Hen-Ming; Cheung, Alice Y.

    2011-01-01

    Background RAC/ROPs are RHO-type GTPases and are known to play diverse signalling roles in plants. Cytoplasmic RAC/ROPs are recruited to the cell membrane and activated in response to extracellular signals perceived and mediated by cell surface-located signalling assemblies, transducing the signals to regulate cellular processes. More than any other cell types in plants, pollen tubes depend on continuous interactions with an extracellular environment produced by their surrounding tissues as they grow within the female organ pistil to deliver sperm to the female gametophyte for fertilization. Scope We review studies on pollen tube growth that provide compelling evidence indicating that RAC/ROPs are crucial for regulating the cellular processes that underlie the polarized cell growth process. Efforts to identify cell surface regulators that mediate extracellular signals also point to RAC/ROPs being the molecular switches targeted by growth-regulating female factors for modulation to mediate pollination and fertilization. We discuss a large volume of work spanning more than two decades on a family of pollen-specific receptor kinases and some recent studies on members of the FERONIA family of receptor-like kinases (RLKs). Significance The research described shows the crucial roles that two RLK families play in transducing signals from growth regulatory factors to the RAC/ROP switch at the pollen tube apex to mediate and target pollen tube growth to the female gametophyte and signal its disintegration to achieve fertilization once inside the female chamber. PMID:22476487

  5. Insulin-like growth factors in endometrioid adenocarcinoma: Correlation with clinico-pathological features and estrogen receptor expression

    International Nuclear Information System (INIS)

    Liang, Yuan-Jiao; Hao, Qun; Zhang, Hui-Ming; Wu, Yuan-Zhe; Wang, Jian-Dong

    2012-01-01

    Endometrial carcinoma is a common malignancy of female genital tract. Insulin-like growth factor is known to elicit estrogen-induced mitogenic activity and anti-apoptotic effect in endometrial tissues. The retrospective study investigated the expression of insulin-like growth factors, estrogen receptors and their associations in endometrioid adenocarcinoma (EAC) from 80 EAC patients in immunohistochemistry, and 58 EAC patients and 42 control patients in quantitative RT-PCR. The Pearson correlation analysis was used to analyze their correlations with clinic-pathological parameters. Our results showed that insulin-like growth factor-1 and insulin-like growth factor-2 mRNA levels were higher in tumor tissues and tumor-adjacent tissues than those in control cells, and were inversely correlated with the malignancy of the tumor with a positive correlation with ERα and ERβ expression. Insulin-like growth factor-1R protein expression was correlated with clinical stage, and insulin-like growth factor-2R protein expression was inversely correlated with histological grade. Insulin-like growth factor system plays an important role in estrogen-induced endometrial carcinogenesis, and overexpression of insulin-like growth factor-1R in the advanced endometrioid adenocarcinoma is not estrogen-dependent

  6. A potential role for lamellar insulin-like growth factor-1 receptor in the pathogenesis of hyperinsulinaemic laminitis.

    Science.gov (United States)

    de Laat, Melody A; Pollitt, Christopher C; Kyaw-Tanner, Myat T; McGowan, Catherine M; Sillence, Martin N

    2013-08-01

    The reason why a sustained high concentration of insulin induces laminitis in horses remains unclear. Cell proliferation occurs in the lamellae during insulin-induced laminitis and in other species high concentrations of insulin can activate receptors for the powerful cell mitogen, insulin-like growth factor (IGF)-1. The first aim of this study was to determine if IGF-1 receptors (IGF-1R) are activated in the hoof during insulin-induced laminitis. Gene expression for IGF-1R and the insulin receptor (InsR) was measured using qRT-PCR, in lamellar tissue from control horses and from horses undergoing a prolonged euglycaemic, hyperinsulinaemic clamp (p-EHC), during the mid-developmental (24h) and acute (46 h) phases of insulin-induced laminitis. Gene expression for both receptors was decreased 13-32-fold (Plaminitis. Targeting this receptor may provide insights into the pathogenesis or identify a novel therapy for hyperinsulinaemic laminitis. Copyright © 2013 Elsevier Ltd. All rights reserved.

  7. The phosphatidylinositol-3 kinase pathway is not essential for insulin-like growth factor I receptor-mediated clonogenic radioresistance

    International Nuclear Information System (INIS)

    Yu, Dong; Watanabe, Hiroshi; Shibuya, Hitoshi; Miura, Masahiko

    2002-01-01

    The insulin-like growth factor I receptor (IGF-IR) is known to induce clonogenic radioresistance in cells following ionizing irradiation. To explore the downstream signaling pathways, we focused on the phosphatidylinositol-3 kinase (PI3-K) pathway, which is thought to be the primary cell survival signal originating from the receptor. For this purpose, R- cells deficient in the endogenous IGF-IR were used as a recipient of the human IGF-IR with or without mutations at potential PI3-K activation sites: NPXY 950 and Y 1316 XXM. Mutats with double mutation at Y950/Y1316 exhibited not abrogated, but reduced activation of insulin receptor substance-1 (IRS-1), PI3-K, and Akt upon IGF-I stimulation. However, the mutants had the same clonogenic radioresistance as cells with wild type (WT) receptors. Neither wortmannin nor LY294002, specific inhibitors of PI3-K, affected the radioresistance of cells with WT receptors at concentrations specific for PI3-K. Collectively, these results indicate that the PI3-K pathway is not essential for IGF-IR-mediated clonogenic radioresistance. (author)

  8. Modes of Action and Functions of ERECTA-family Receptor-like Kinases in Plant Organ Growth and Development

    Energy Technology Data Exchange (ETDEWEB)

    TORII, Keiko U.

    2012-05-01

    Higher plants constitute the central resource for renewable lignocellulose biomass that can supplement for the world's depleting stores of fossil fuels. As such, understanding the molecular and genetic mechanisms of plant organ growth will provide key knowledge and genetic resources that enables manipulation of plant biomass feedstock for better growth and productivity. The goal of this proposal is to understand how cell proliferation and growth are coordinated during aboveground organ morphogenesis, and how cell-cell signaling mediated by a family of receptor kinases coordinates plant organogenesis. The well-established model plant Arabidopsis thaliana is used for our research to facilitate rapid progress. Specifically, we focus on how ERECTA-family leucine-rich repeat receptor kinases (LRR-RLKs) interact in a synergistic manner to promote organogenesis and pattern formation in Arabidopsis. This project was highly successful, resulted in fourteen publications including nine peer-reviewed original research articles. One provisional US patent has been filed through this DOE funding. We have addressed the critical roles for a family of receptor kinases in coordinating proliferation and differentiation of plants, and we successfully elucidated the downstream targets of this signaling pathway in specifying stomatal patterning.

  9. Smoking-associated lung cancer prevention by blockade of the beta-adrenergic receptor-mediated insulin-like growth factor receptor activation.

    Science.gov (United States)

    Min, Hye-Young; Boo, Hye-Jin; Lee, Ho Jin; Jang, Hyun-Ji; Yun, Hye Jeong; Hwang, Su Jung; Smith, John Kendal; Lee, Hyo-Jong; Lee, Ho-Young

    2016-10-25

    Activation of receptor tyrosine kinases (RTKs) is associated with carcinogenesis, but its contribution to smoking-associated lung carcinogenesis is poorly understood. Here we show that a tobacco-specific carcinogen 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK)-induced insulin-like growth factor 1 receptor (IGF-1R) activation via β-adrenergic receptor (β-AR) is crucial for smoking-associated lung carcinogenesis. Treatment with NNK stimulated the IGF-1R signaling pathway in a time- and dose-dependent manner, which was suppressed by pharmacological or genomic blockade of β-AR and the downstream signaling including a Gβγ subunit of β-AR and phospholipase C (PLC). Consistently, β-AR agonists led to increased IGF-1R phosphorylation. The increase in IGF2 transcription via β-AR, signal transducer and activator of transcription 3 (STAT3), and nuclear factor-kappa B (NF-κB) was associated with NNK-induced IGF-1R activation. Finally, treatment with β-AR antagonists suppressed the acquisition of transformed phenotypes in lung epithelial cells and lung tumor formation in mice. These results suggest that blocking β-AR-mediated IGF-1R activation can be an effective strategy for lung cancer prevention in smokers.

  10. Cooperation of tyrosine kinase receptor TrkB and epidermal growth factor receptor signaling enhances migration and dispersal of lung tumor cells.

    Directory of Open Access Journals (Sweden)

    Rudolf Götz

    Full Text Available TrkB mediates the effects of brain-derived neurotrophic factor (BDNF in neuronal and nonnneuronal cells. Based on recent reports that TrkB can also be transactivated through epidermal growth-factor receptor (EGFR signaling and thus regulates migration of early neurons, we investigated the role of TrkB in migration of lung tumor cells. Early metastasis remains a major challenge in the clinical management of non-small cell lung cancer (NSCLC. TrkB receptor signaling is associated with metastasis and poor patient prognosis in NSCLC. Expression of this receptor in A549 cells and in another adenocarcinoma cell line, NCI-H441, promoted enhanced migratory capacity in wound healing assays in the presence of the TrkB ligand BDNF. Furthermore, TrkB expression in A549 cells potentiated the stimulatory effect of EGF in wound healing and in Boyden chamber migration experiments. Consistent with a potential loss of cell polarity upon TrkB expression, cell dispersal and de-clustering was induced in A549 cells independently of exogeneous BDNF. Morphological transformation involved extensive cytoskeletal changes, reduced E-cadherin expression and suppression of E-cadherin expression on the cell surface in TrkB expressing tumor cells. This function depended on MEK and Akt kinase activity but was independent of Src. These data indicate that TrkB expression in lung adenoma cells is an early step in tumor cell dissemination, and thus could represent a target for therapy development.

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

    DEFF Research Database (Denmark)

    Manfè, Valentina; Kochoyan, Artur; Bock, Elisabeth

    2010-01-01

    J. Neurochem. (2010) 10.1111/j.1471-4159.2010.06718.x Abstract Basic fibroblast growth factor (FGF2, bFGF) is the most extensively studied member of the FGF family and is involved in neurogenesis, differentiation, neuroprotection, and synaptic plasticity in the CNS. FGF2 executes its pleiotropic...

  12. d3-Growth hormone receptor polymorphism in acromegaly: effects on metabolic phenotype.

    Science.gov (United States)

    Montefusco, Laura; Filopanti, Marcello; Ronchi, Cristina L; Olgiati, Luca; La-Porta, Carmen; Losa, Marco; Epaminonda, Paolo; Coletti, Francesca; Beck-Peccoz, Paolo; Spada, Anna; Lania, Andrea G; Arosio, Maura

    2010-05-01

    A common polymorphic variant of the growth hormone receptor (GHR) is because of genomic deletion of exon 3 and has been linked with increased responsiveness to exogenous GH. The impact of this polymorphism in acromegaly, a disease characterized by endogenous excess of GH and partial loss of IGF-I feedback on tumoural GH secretion, is not clear. The aim of this study was to investigate possible influences of d3GHR on the GH/IGF-I relationship and metabolic parameters in acromegaly. Retrospective study on 76 acromegalic patients. Genotype analysis was carried out on leucocyte DNA by multiplex PCR assay. Clinical, hormonal and biochemical parameters at diagnosis were collected from patients' medical records. Forty-two patients (55.3%) were homozygotes for the allele encoding the full-length GHR (fl/flGHR), 27 patients were heterozygotes (fl/d3) and seven homozygotes (d3/d3) for the genomic deletion of exon 3. Heterozygotes and homozygotes for the d3 allele were considered together (d3GHR) and compared with fl/flGHR patients. d3GHR and fl/flGHR patients showed no difference in GH and IGF-I levels or in the relationship between these two parameters. Patients bearing d3GHR had a lower body mass index (BMI) than patients bearing fl/flGHR (25.8 +/- 2.1 vs. 28.1 +/- 4.8 kg/m(2), P d3GHR patients had a normal glucose tolerance (66.7%vs. 56.3%, P d3GHR allele, and not BMI or age, was a significant negative predictor of insulin levels 120 min after oral glucose load (beta = -80.8, P d3GHR is functionally different from the fl/fl variant mostly for the effects on body weight regulation and on glucose metabolism.

  13. Microenvironmental Stiffness Enhances Glioma Cell Proliferation by Stimulating Epidermal Growth Factor Receptor Signaling

    Science.gov (United States)

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

    2014-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Vaibhavi Umesh

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

  15. Increased hepatic expression of insulin-like growth factor-I receptor in chronic hepatitis C

    Science.gov (United States)

    Stefano, José Tadeu; Corrêa-Giannella, Maria Lúcia; Ribeiro, Cristiane Maria Freitas; Alves, Venâncio Avancini Ferreira; Massarollo, Paulo Celso Bosco; Machado, Marcel Cerqueira Cesar; Giannella-Neto, Daniel

    2006-01-01

    AIM: Although increased insulin-like growth factor-I receptor (IGF-IR) gene expression has been reported in hepatocellular carcinoma, studies assessing IGF-IR in chronic hepatitis C (CHC) and cirrhosis are scarce. We therefore aimed to evaluate IGF-IR and IGF-I mRNA expression in liver from patient with CHC. METHODS: IGF-IR and IGF-I mRNA content were determined by semi-quantitative RT-PCR and IGF-IR protein expression was determined by immunohisto-chemistry in hepatic tissue obtained from patients with CHC before (34 patients) and after (10 patients) therapy with interferon-α and ribavirin. RESULTS: An increase of IGF-IR mRNA content was observed in hepatic tissue obtained from all CHC patients as well as from 6 cadaveric liver donors following orthopic transplantation (an attempt to evaluate normal livers) in comparison to normal liver, while no relevant modifications were detected in IGF-I mRNA content. The immunohistochemical results showed that the raise in IGF-IR mRNA content was related both to ductular reaction and to increased IGF-IR expression in hepatocytes. A decrease in IGF-IR mRNA content was observed in patients who achieved sustained virological response after therapy, suggesting an improvement in hepatic damage. CONCLUSION: The up-regulation of IGF-IR expression in hepatocytes of patients with CHC could constitute an attempt to stimulate hepatocyte regeneration. Considering that liver is the organ with the highest levels of IGF-I, our finding of increased IGF-IR expression after both acute and chronic hepatic damage highlights the need for additional studies to elucidate the role of IGF-I in liver regeneration. PMID:16804965

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

    International Nuclear Information System (INIS)

    This study explores whether meningioma expresses epidermal growth factor receptor (EGFR) and determines if there is a correlation between the WHO grade of this tumor and the degree of EGFR expression. Following institutional review board approval, 113 meningioma specimens from 89 patients were chosen. Of these, 85 were used for final analysis. After a blinded review, immunohistochemical stains for EGFR were performed. Staining intensity (SI) was scored on a scale 0-3 (from no staining to strong staining). Staining percentage of immunoreactive cells (SP) was scored 1-5 (from the least to the maximum percent of the specimen staining). Immunohistochemical score (IHS) was calculated as the product of SI and SP. Eighty-five samples of meningioma were classified in accordance with World Health Organization (WHO) criteria: benign 57/85 (67%), atypical 23/85 (27%), and malignant 5/85 (6%). The majority of samples demonstrated a moderate SI for EGFR. IHS for EGFR demonstrated a significant association between SI and histopathologic subtype. Also, there was a correlation between the SP and histopathologic subtype (p = 0.029). A significant association was determined when the benign and the atypical samples were compared to the malignant with respect to the SP (p = 0.009). While there was a range of the IHS for the benign and the atypical histologic subtypes, malignant tumors exhibited the lowest score and were statistically different from the benign and the atypical specimens (p < 0.001). To our knowledge, this represents the largest series of meningioma samples analyzed for EGFR expression reported in the literature. EGFR expression is greatest in benign meningiomas and may serve a potential target for therapeutic intervention with selective EGFR inhibitors

  17. Insulin receptors mediate growth effects in cultured fetal neurons. I. Rapid stimulation of protein synthesis

    International Nuclear Information System (INIS)

    Heidenreich, K.A.; Toledo, S.P.

    1989-01-01

    In this study we have examined the effects of insulin on protein synthesis in cultured fetal chick neurons. Protein synthesis was monitored by measuring the incorporation of [3H]leucine (3H-leu) into trichloroacetic acid (TCA)-precipitable protein. Upon addition of 3H-leu, there was a 5-min lag before radioactivity occurred in protein. During this period cell-associated radioactivity reached equilibrium and was totally recovered in the TCA-soluble fraction. After 5 min, the incorporation of 3H-leu into protein was linear for 2 h and was inhibited (98%) by the inclusion of 10 micrograms/ml cycloheximide. After 24 h of serum deprivation, insulin increased 3H-leu incorporation into protein by approximately 2-fold. The stimulation of protein synthesis by insulin was dose dependent (ED50 = 70 pM) and seen within 30 min. Proinsulin was approximately 10-fold less potent than insulin on a molar basis in stimulating neuronal protein synthesis. Insulin had no effect on the TCA-soluble fraction of 3H-leu at any time and did not influence the uptake of [3H]aminoisobutyric acid into neurons. The isotope ratio of 3H-leu/14C-leu in the leucyl tRNA pool was the same in control and insulin-treated neurons. Analysis of newly synthesized proteins by sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed that insulin uniformly increased the incorporation of 14C-leu into all of the resolved neuronal proteins. We conclude from these data that (1) insulin rapidly stimulates overall protein synthesis in fetal neurons independent of amino acid uptake and aminoacyl tRNA precursor pools; (2) stimulation of protein synthesis is mediated by the brain subtype of insulin receptor; and (3) insulin is potentially an important in vivo growth factor for fetal central nervous system neurons

  18. Human blood-brain barrier insulin-like growth factor receptor

    International Nuclear Information System (INIS)

    Duffy, K.R.; Pardridge, W.M.; Rosenfeld, R.G.

    1988-01-01

    Insulin-like growth factor (IGF)-1 and IGF-2, may be important regulatory molecules in the CNS. Possible origins of IGFs in brain include either de novo synthesis or transport of circulating IGFs from blood into brain via receptor mediated transcytosis mechanisms at the brain capillary endothelial wall, ie, the blood-brain barrier (BBB). In the present studies, isolated human brain capillaries are used as an in vitro model system of the human BBB and the characteristics of IGF-1 or IGF-2 binding to this preparation were assessed. The total binding of IGF-2 at 37 degrees C exceeded 130% per mg protein and was threefold greater than the total binding for IGF-1. However, at 37 degrees C nonsaturable binding equaled total binding, suggesting that endocytosis is rate limiting at physiologic temperatures. Binding studies performed at 4 degrees C slowed endocytosis to a greater extent than membrane binding, and specific binding of either IGF-1 or IGF-2 was detectable. Scatchard plots for either peptide were linear and the molar dissociation constant of IGF-1 and IGF-2 binding was 2.1 +/- 0.4 and 1.1 +/- 0.1 nmol/L, respectively. Superphysiologic concentrations of porcine insulin inhibited the binding of both IGF-1 (ED50 = 2 micrograms/mL) and IGF-2 (ED50 = 0.5 microgram/mL). Affinity cross linking of 125 I-IGF-1, 125 I-IGF-2, and 125 I-insulin to isolated human brain capillaries was performed using disuccinimidylsuberate (DSS). These studies revealed a 141 kd binding site for both IGF-1 and IGF-2, and a 133 kd binding site for insulin

  19. Disruption of growth hormone receptor prevents calorie restriction from improving insulin action and longevity.

    Directory of Open Access Journals (Sweden)

    Michael S Bonkowski

    Full Text Available Most mutations that delay aging and prolong lifespan in the mouse are related to somatotropic and/or insulin signaling. Calorie restriction (CR is the only intervention that reliably increases mouse longevity. There is considerable phenotypic overlap between long-lived mutant mice and normal mice on chronic CR. Therefore, we investigated the interactive effects of CR and targeted disruption or knock out of the growth hormone receptor (GHRKO in mice on longevity and the insulin signaling cascade. Every other day feeding corresponds to a mild (i.e. 15% CR which increased median lifespan in normal mice but not in GHRKO mice corroborating our previous findings on the effects of moderate (30% CR on the longevity of these animals. To determine why insulin sensitivity improves in normal but not GHRKO mice in response to 30% CR, we conducted insulin stimulation experiments after one year of CR. In normal mice, CR increased the insulin stimulated activation of the insulin signaling cascade (IR/IRS/PI3K/AKT in liver and muscle. Livers of GHRKO mice responded to insulin by increased activation of the early steps of insulin signaling, which was dissipated by altered PI3K subunit abundance which putatively inhibited AKT activation. In the muscle of GHRKO mice, there was elevated downstream activation of the insulin signaling cascade (IRS/PI3K/AKT in the absence of elevated IR activation. Further, we found a major reduction of inhibitory Ser phosphorylation of IRS-1 seen exclusively in GHRKO muscle which may underpin their elevated insulin sensitivity. Chronic CR failed to further modify the alterations in insulin signaling in GHRKO mice as compared to normal mice, likely explaining or contributing to the absence of CR effects on insulin sensitivity and longevity in these long-lived mice.

  20. Transforming growth factor beta receptor II polymorphisms are associated with Kawasaki disease

    Directory of Open Access Journals (Sweden)

    Yu Mi Choi

    2012-01-01

    Full Text Available Purpose : Transforming growth factor beta receptor 2 (TGFBR2 is a tumor suppressor gene that plays a role in the differentiation of striated cells and remodeling of coronary arteries. Single nucleotide polymorphisms (SNPs of this gene are associated with Marfan syndrome and sudden death in patients with coronary artery disease. Cardiovascular remodeling and T cell activation of TGFBR2 gene suggest that the TGFBR2 gene SNPs are related to the pathogenesis of Kawasaki disease (KD and coronary artery lesion (CAL. Methods : The subjects were 105 patients with KD and 500 healthy adults as controls. Mean age of KD group was 32 months age and 26.6% of those had CAL. We selected TGFBR2 gene SNPs from serum and performed direct sequencing. Results : The sequences of the eleven SNPs in the TGFBR2 gene were compared between the KD group and controls. Three SNPs (rs1495592, rs6550004, rs795430 were associated with development of KD (P=0.019, P=0.026, P=0.016, respectively. One SNP (rs1495592 was associated with CAL in KD group (P=0.022. Conclusion : Eleven SNPs in TGFBR2 gene were identified at that time the genome wide association. But, with the change of the data base, only six SNPs remained associated with the TGFBR2 gene. One of the six SNPs (rs6550004 was associated with development of KD. One SNP associated with CAL (rs1495592 was disassociated from the TGFBR2 gene. The other five SNPs were not functionally identified, but these SNPs are notable because the data base is changing. Further studies involving larger group of patients with KD are needed.

  1. Type I Insulin-like Growth Factor Receptor Induces Pulmonary Tumorigenesis

    Directory of Open Access Journals (Sweden)

    Nicolle M. Linnerth

    2009-07-01

    Full Text Available Despite the type I insulin-like growth factor receptor (IGF-IR being highly expressed in more than 80% of human lung tumors, a transgenic model of IGF-IR overexpression in the lung has not been created. We produced two novel transgenic mouse models in which IGF-IR is overexpressed in either lung type II alveolar cells (surfactant protein C [SPC]-IGFIR or Clara cells (CCSP-IGFIR in a doxycycline-inducible manner. Overexpression of IGF-IR in either cell type caused multifocal adenomatous alveolar hyperplasia with papillary and solid adenomas. These tumors expressed thyroid transcription factor 1 and Kruppel-like factor 5 in most tumor cells. Similar to our previous work with lung tumors that developed in the mouse mammary tumor virus-IGF-II transgenic mice, the lung tumors that develop in the SPC-IGFIR and CCSP-IGFIR transgenic mice expressed high levels of the cyclic adenosine monophosphate response element binding protein that was localized primarily to the nucleus. Although elevated IGF-IR expression can initiate lung tumor development, tumors can become independent of IGF-IR signaling as IGF-IR down-regulation in established tumors produced tumor regression in some, but not all, of the tumors. These findings implicate IGF-IR as an important initiator of lung tumorigenesis and suggest that the SPC-IGFIR and CCSP-IGFIR transgenic mice can be used to further our understanding of human lung cancer and the role IGF-IR plays in this disease.

  2. Epidermal growth factor receptor signaling mediates aldosterone-induced profibrotic responses in kidney

    Energy Technology Data Exchange (ETDEWEB)

    Sheng, Lili; Yang, Min; Ding, Wei [Department of Nephrology, Shanghai Fifth People' s Hospital, Fudan University, Shanghai 200240 (China); Zhang, Minmin [Department of Nephrology, Shanghai Huashan Hospital, Fudan University, Shanghai 200240 (China); Niu, Jianying [Department of Nephrology, Shanghai Fifth People' s Hospital, Fudan University, Shanghai 200240 (China); Qiao, Zhongdong [School of Life Science and Biotechnology, Shanghai Jiaotong University, Shanghai 200240 (China); Gu, Yong, E-mail: yonggu@vip.163.com [Department of Nephrology, Shanghai Fifth People' s Hospital, Fudan University, Shanghai 200240 (China); Department of Nephrology, Shanghai Huashan Hospital, Fudan University, Shanghai 200240 (China)

    2016-08-01

    Aldosterone has been recognized as a risk factor for the development of chronic kidney disease (CKD). Studies have indicated that enhanced activation of epidermal growth factor receptor (EGFR) is associated with the development and progression of renal fibrosis. But if EGFR is involved in aldosterone-induced renal fibrosis is less investigated. In the present study, we examined the effect of erlotinib, an inhibitor of EGFR tyrosine kinase activity, on the progression of aldosterone-induced renal profibrotic responses in a murine model underwent uninephrectomy. Erlotinib-treated rats exhibited relieved structural lesion comparing with rats treated with aldosterone alone, as characterized by glomerular hypertrophy, mesangial cell proliferation and expansion. Also, erlotinib inhibited the expression of TGF-β, α-SMA and mesangial matrix proteins such as collagen Ⅳ and fibronectin. In cultured mesangial cells, inhibition of EGFR also abrogated aldosterone-induced expression of extracellular matrix proteins, cell proliferation and migration. We also demonstrated that aldosterone induced the phosphorylation of EGFR through generation of ROS. And the activation of EGFR resulted in the phosphorylation of ERK1/2, leading to the activation of profibrotic pathways. Taken together, we concluded that aldosterone-mediated tissue fibrosis relies on ROS induced EGFR/ERK activation, highlighting EGFR as a potential therapeutic target for modulating renal fibrosis. - Highlights: • EGFR was involved in aldosterone-induced renal profibrotic responses. • Aldosterone-induced EGFR activation was mediated by MR-dependent ROS generation. • EGFR activated the MAPK/ERK1/2 signaling to promote renal fibrosis.

  3. The prognostic impact of epidermal growth factor receptor in patients with metastatic gastric cancer

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    Atmaca Akin

    2012-11-01

    Full Text Available Abstract Background The epidermal growth factor receptor (EGFR is a potential target of anticancer therapy in gastric cancer. However, its prognostic role in metastatic gastric or gastroesophageal junction (GE cancer has not been established yet. Methods EGFR status was analyzed by immunohistochemistry (IHC in paraffin-embedded samples from 357 patients who received chemotherapy in 4 first-line trials. Automated RNA extraction from paraffin and RT-quantitative PCR were additionally used to evaluate EGFR mRNA expression in 130 patients. Results EGFR protein expression (any grade and overexpression (3+ were observed in 43% and 11% of patients, respectively. EGFR positivity correlated with intestinal type histology (p = 0.05, but not with other clinicopathologic characteristics. Median follow-up was 18.2 months. Median overall survival (OS was similar in patients with EGFR positive vs. those with EGFR negative tumors, regardless whether positivity was defined as ≥1+ (10.6 vs. 10.9 months, p = 0.463 or as 3+ (8.6 vs. 10.8 months, p = 0.377. The multivariate analysis indicated that EGFR status is not an independent prognostic factor (hazard ratio 0.85, 0.56 to 1.12, p = 0.247. There were also no significant differences in overall survival when patients were categorized according to median (p = 0.116 or quartile (p = 0.767 distribution of EGFR mRNA gene expression. Similar distributions of progression-free survival according to EGFR status were observed. Conclusions Unlike different cancer types where EGFR-positive disease is associated with an adverse prognostic value, EGFR positivity is not prognostic of patient outcome in metastatic gastric or GE cancer.

  4. A new PET tracer specific for vascular endothelial growth factor receptor

    International Nuclear Information System (INIS)

    Wang, Hui; Cai, Weibo; Chen, Kai; Li, Zi-Bo; Kashefi, Amir; He, Lina; Chen, Xiaoyuan

    2007-01-01

    Noninvasive positron emission tomography (PET) imaging of vascular endothelial growth factor receptor 2 (VEGFR-2) expression could be a valuable tool for evaluation of patients with a variety of malignancies, and particularly for monitoring those undergoing antiangiogenic therapies that block VEGF/VEGFR-2 function. The aim of this study was to develop a VEGFR-2-specific PET tracer. The D63AE64AE67A mutant of VEGF 121 (VEGF DEE ) was generated by recombinant DNA technology. VEGF 121 and VEGF DEE were purified and conjugated with DOTA for 64 Cu labeling. The DOTA conjugates were tested in vitro for VEGFR-2 specificity and functional activity. In vivo tumor targeting efficacy and pharmacokinetics of 64 Cu-labeled VEGF 121 and VEGF DEE were compared using an orthotopic 4T1 murine breast tumor model. Blocking experiments, biodistribution studies, and immunofluorescence staining were carried out to confirm the noninvasive imaging results. Cell binding assay demonstrated that VEGF DEE had about 20-fold lower VEGFR-1 binding affinity and only slightly lower VEGFR-2 binding affinity as compared with VEGF 121 . MicroPET imaging studies revealed that both 64 Cu-DOTA-VEGF 121 and 64 Cu-DOTA-VEGF DEE had rapid and prominent activity accumulation in VEGFR-2-expressing 4T1 tumors. The renal uptake of 64 Cu-DOTA-VEGF DEE was significantly lower than that of 64 Cu-DOTA-VEGF 121 as rodent kidneys expressed high levels of VEGFR-1 based on immunofluorescence staining. Blocking experiments and biodistribution studies confirmed the VEGFR specificity of 64 Cu-DOTA-VEGF DEE . We have developed a VEGFR-2-specific PET tracer, 64 Cu-DOTA-VEGF DEE . It has comparable tumor targeting efficacy to 64 Cu-DOTA-VEGF 121 but much reduced renal toxicity. This tracer may be translated into the clinic for imaging tumor angiogenesis and monitoring antiangiogenic treatment efficacy. (orig.)

  5. Radiolabeled pertuzumab for imaging of human epidermal growth factor receptor 2 expression in ovarian cancer

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Dawei [Shenzhen University, Guangdong Key Laboratory for Biomedical Measurements and Ultrasound Imaging, School of Biomedical Engineering, Shenzhen (China); University of Wisconsin - Madison, Department of Radiology, Madison, WI (United States); Im, Hyung-Jun [University of Wisconsin - Madison, Department of Radiology, Madison, WI (United States); Seoul National University, Graduate School of Convergence Science and Technology, Seoul (Korea, Republic of); Sun, Haiyan; Cho, Steve Y. [University of Wisconsin - Madison, Department of Radiology, Madison, WI (United States); Valdovinos, Hector F.; England, Christopher G.; Ehlerding, Emily B.; Nickles, Robert J. [University of Wisconsin - Madison, Department of Medical Physics, Madison, WI (United States); Lee, Dong Soo [Seoul National University, Graduate School of Convergence Science and Technology, Seoul (Korea, Republic of); Huang, Peng [Shenzhen University, Guangdong Key Laboratory for Biomedical Measurements and Ultrasound Imaging, School of Biomedical Engineering, Shenzhen (China); Cai, Weibo [University of Wisconsin - Madison, Department of Radiology, Madison, WI (United States); University of Wisconsin - Madison, Department of Medical Physics, Madison, WI (United States); University of Wisconsin Carbone Cancer Center, Madison, WI (United States)

    2017-08-15

    Human epidermal growth factor receptor 2 (HER2) is over-expressed in over 30% of ovarian cancer cases, playing an essential role in tumorigenesis and metastasis. Non-invasive imaging of HER2 is of great interest for physicians as a mean to better detect and monitor the progression of ovarian cancer. In this study, HER2 was assessed as a biomarker for ovarian cancer imaging using {sup 64}Cu-labeled pertuzumab for immunoPET imaging. HER2 expression and binding were examined in three ovarian cancer cell lines (SKOV3, OVCAR3, Caov3) using in vitro techniques, including western blot and saturation binding assays. PET imaging and biodistribution studies in subcutaneous models of ovarian cancer were performed for non-invasive in vivo evaluation of HER2 expression. Additionally, orthotopic models were employed to further validate the imaging capability of {sup 64}Cu-NOTA-pertuzumab. HER2 expression was highest in SKOV3 cells, while OVCAR3 and Caov3 displayed lower HER2 expression. {sup 64}Cu-NOTA-pertuzumab showed high specificity for HER2 (K{sub a} = 3.1 ± 0.6 nM) in SKOV3. In subcutaneous tumors, PET imaging revealed tumor uptake of 41.8 ± 3.8, 10.5 ± 3.9, and 12.1 ± 2.3%ID/g at 48 h post-injection for SKOV3, OVCAR3, and Caov3, respectively (n = 3). In orthotopic models, PET imaging with {sup 64}Cu-NOTA-pertuzumab allowed for rapid and clear delineation of both primary and small peritoneal metastases in HER2-expressing ovarian cancer. {sup 64}Cu-NOTA-pertuzumab is an effective PET tracer for the non-invasive imaging of HER2 expression in vivo, rendering it a potential tracer for treatment monitoring and improved patient stratification. (orig.)

  6. Epidermal growth factor receptor mutations in lung adenocarcinoma in Malaysian patients.

    Science.gov (United States)

    Liam, Chong-Kin; Wahid, Mohamed Ibrahim A; Rajadurai, Pathmanathan; Cheah, Yoke-Kqueen; Ng, Tiffany Shi-Yeen

    2013-06-01

    Despite available data from other Asian countries, the prevalence of epidermal growth factor receptor (EGFR) mutations among lung adenocarcinoma patients has not been reported in Malaysia. This study sought to determine the frequency of EGFR mutations among multiethnic Malaysian patients diagnosed with lung adenocarcinoma. Demographic and clinical information of patients whose lung adenocarcinoma biopsy specimens were submitted for EGFR mutation testing at Sime Darby Medical Center from 2009 to 2011 were analyzed. EGFR mutations at exons 18, 19, 20, and 21 were detected either through bidirectional sequencing or real-time polymerase chain reaction. Among 812 patients in the study, 49% were female, 63.7% were ethnic Chinese, 29.4% Malay, 4.8% Indian, and 2.1% other ethnic groups. Mutations were present in the tumors of 321 patients (39.5%), with mutations at exons 19 (23.5%) and 21 (14.9%) being the most common. Mutations were significantly more frequent among women than in men (52.5% versus 27.8%, p < 0.001). Although mutations were more common among Chinese (40.8%) compared with Malay (37.2%) or Indian (33.3%) patients, the difference was not statistically significant (p = 0.591). Of 211 patients with smoking history records, never-smokers had a higher mutation rate compared with ever-smokers (54.8% versus 20.7%, p < 0.001). EGFR mutations were present in 39.5% of patients. Mutations were more common in women and never-smokers with no differences in mutation frequency between different ethnicities. Because of the high mutation rates, reflex testing for EGFR mutation should be a routine practice for advanced lung adenocarcinoma patients in Malaysia.

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

    Directory of Open Access Journals (Sweden)

    Perry Arie

    2010-05-01

    Full Text Available Abstract Purpose This study explores whether meningioma expresses epidermal growth factor receptor (EGFR and determines if there is a correlation between the WHO grade of this tumor and the degree of EGFR expression. Methods Following institutional review board approval, 113 meningioma specimens from 89 patients were chosen. Of these, 85 were used for final analysis. After a blinded review, immunohistochemical stains for EGFR were performed. Staining intensity (SI was scored on a scale 0-3 (from no staining to strong staining. Staining percentage of immunoreactive cells (SP was scored 1-5 (from the least to the maximum percent of the specimen staining. Immunohistochemical score (IHS was calculated as the product of SI and SP. Results Eighty-five samples of meningioma were classified in accordance with World Health Organization (WHO criteria: benign 57/85 (67%, atypical 23/85 (27%, and malignant 5/85 (6%. The majority of samples demonstrated a moderate SI for EGFR. IHS for EGFR demonstrated a significant association between SI and histopathologic subtype. Also, there was a correlation between the SP and histopathologic subtype (p = 0.029. A significant association was determined when the benign and the atypical samples were compared to the malignant with respect to the SP (p = 0.009. While there was a range of the IHS for the benign and the atypical histologic subtypes, malignant tumors exhibited the lowest score and were statistically different from the benign and the atypical specimens (p Conclusions To our knowledge, this represents the largest series of meningioma samples analyzed for EGFR expression reported in the literature. EGFR expression is greatest in benign meningiomas and may serve a potential target for therapeutic intervention with selective EGFR inhibitors.

  8. Relationship between activation of epidermal growth factor receptor and cell dissociation in pancreatic cancer.

    Science.gov (United States)

    Tan, Xiaodong; Egami, Hiroshi; Ishikawa, Shinji; Nakagawa, Masahide; Ishiko, Takatoshi; Kamohara, Hidenobu; Hirota, Masahiko; Ogawa, Michio

    2004-11-01

    In our previous investigations, mitogen-activated protein kinase kinase 2 (MEK2)/extracellular signal-regulated kinase 2 (ERK2) signaling pathway was found to be correlated with the cell dissociation induced by dissociation factor (DF) in pancreatic cancer cells. In this study, the expressions of epidermal growth factor receptor (EGFR), phosphorylated EGFR (p-EGFR), and its downstream kinases MEK1/2 and ERK1/2, were analyzed to clarify the regulatory mechanism of cell dissociation in pancreatic cancer cells. Two hamster (PC-1.0 and PC-1) and two human (AsPC-1 and Capan-2) pancreatic cancer cell lines were used. Immunocytochemical study was performed using anti-EGFR, p-EGFR, phosphorylated MEK1/2 (p-MEK1/2), and phosphorylated ERK1/2 (p-ERK1/2) antibodies. DF-treatment markedly induced the expressions of EGFR, p-EGFR, p-MEK1/2, p-ERK1/2, as well as the dissociation of cell colonies in PC-1 and Capan-2 cells. In contrast, AG1478 (an EGFR inhibitor) treatment significantly induced the cell aggregation in PC-1.0 and AsPC-1 cells which usually grew as single cells, but strongly suppressed the expressions of EGFR, p-EGFR, p-MEK1/2, and p-ERK1/2. These observations demonstrate that activation of EGFR is closely involved in cell dissociation in pancreatic cancer through activating MEK/ERK signaling pathway.

  9. Altered transmission of maternal angiotensin II receptor haplotypes in fetal growth restriction.

    Science.gov (United States)

    Tower, Clare; Chappell, Sally; Acharya, Meera; Crane, Richard; Szolin, Stephanie; Symonds, Lyneth; Chevins, Helen; Kalsheker, Noor; Baker, Philip; Morgan, Linda

    2006-02-01

    Fetal growth restriction (FGR) predisposes to significant short- and long-term health problems. Epidemiological studies have suggested a role for inherited factors in its pathogenesis. The angiotensin II receptor genes, AGTR1 and AGTR2, are candidate genes because they mediate processes that are important for placentation. This study investigated AGTR1 and AGTR2 haplotypes and genotypes in FGR. A total of 107 families (father, mother, and baby) with FGR, and 101 families with normal pregnancies were genotyped at five sites in AGTR1 and six sites across AGTR2. All of the participants were white western Europeans. FGR was identified antenatally by ultrasound scans and confirmed postnatally by correcting the birth weight centile for gestation, infant sex, maternal height, weight, and parity. Fetal genes were investigated using transmission disequilibrium testing (TDT), and a case-control comparison of maternal haplotypes was conducted. FGR was associated with maternal (but not paternal) transmission of the AGTR1 haplotype (GenBank AF245699.1) g.4955T, g.5052T, g.5245C, g.5612A, and haplotype g.4955T, g.5052T, g.5245T, g.5612A. Haplotype g.4955A, g.5052G, g.5245T, g.5612G was undertransmitted (P = 0.002). TDT of the AGTR1 genotype showed undertransmission of maternal AGTR1 genotypes g.4955T>A (odds ratio (OR), 0.34 (95% confidence interval (CI), 0.14-0.86); P = 0.02), g.5052T>G (OR, 0.18 (0.06-0.48); PG (OR, 0.21 (0.08-0.55); P 0.10). This is the first study to show distortion of transmission of maternal AGTR1 haplotypes in FGR, which suggests that this gene plays a role in FGR. In particular, maternal-fetal gene sharing may be an important factor. 2006 Wiley-Liss, Inc.

  10. Correlation of human epidermal growth factor receptor protein expression and colorectal cancer.

    Science.gov (United States)

    Yang, Wen-Juan; Shen, Xing-Jie; Ma, Xiao-Xia; Tan, Zhi-Gang; Song, Yan; Guo, Yi-Tong; Yuan, Mei

    2015-07-28

    To investigate the correlation between human epidermal growth factor receptor (HER-2) protein expression and colorectal cancer (CRC) using a case-control study and meta-analysis. Tumor tissue specimens from 162 CRC patients were selected for the case group. Fifty cases were randomly selected, and normal CRC tissue at least 10 cm away from the tumor margins of these cases was used to generate the control group. The expression of the HER-2 protein in the 162 CRC tissue samples and the 50 adjacent normal mucosa tissue samples was detected via immunohistochemistry. The experimental data were analyzed using SPSS 18.0 software, and R software version 3.1.0 was utilized for further verification. The expression of HER-2 protein in the 162 CRC tissue samples was significantly higher than in the normal tissue specimens. The data showed that the expression of HER-2 in CRC was related to the Dukes' stage, the depth of invasion and lymph node metastasis. The HER-2-positive patients had lower 3- and 5-year OS rates than the HER-2-negative patients, but there was no significant difference. However, there was a statistically significant difference in the 3- and 5-year disease-free survival (DFS) rates of HER-2-positive and HER-2-negative patients. The results of the meta-analysis showed that the expression of HER-2 in CRC patients was statistically significantly increased over that of healthy people. The 3-year DFS rate in HER-2-positive patients was markedly lower than that in HER-2-negative patients. Down-regulation of HER-2 expression might be a dependable strategy for CRC therapy.

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

    Science.gov (United States)

    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. © 2011 The Authors. Development, Growth & Differentiation © 2011 Japanese Society of Developmental Biologists.

  12. Unsaturated fatty acids prevent desensitization of the human growth hormone secretagogue receptor by blocking its internalization

    NARCIS (Netherlands)

    P.J.D. Delhanty (Patric); A. Kerkwijk (Anke); M. Huisman (Martijn); B. van de Zande (Bedette); M. Verhoef-Post (Miriam); C. Gauna (Carlotta); L.J. Hofland (Leo); A.P.N. Themmen (Axel); A-J. van der Lely (Aart-Jan)

    2010-01-01

    textabstractThe composition of the plasma membrane affects the responsiveness of cells to metabolically important hormones such as insulin and vasoactive intestinal peptide. Ghrelin is a metabolically regulated hormone that activates the G protein-coupled receptor GH secretagogue receptor type 1a

  13. A growth hormone receptor SNP promotes lung cancer by impairment of SOCS2-mediated degradation

    DEFF Research Database (Denmark)

    Chhabra, Y.; Wong, H. Y.; Nikolajsen, Louise Fletcher

    2018-01-01

    binding to the GHR is impaired by a threonine substitution at Pro 495. This results in decreased internalisation and degradation of the receptor evident in TIRF microscopy and by measurement of mature (surface) receptor expression. Mutational analysis showed that the residue at position 495 impairs SOCS2...

  14. The ABA receptor PYL8 promotes lateral root growth by enhancing MYB77-dependent transcription of auxin-responsive genes.

    Science.gov (United States)

    Zhao, Yang; Xing, Lu; Wang, Xingang; Hou, Yueh-Ju; Gao, Jinghui; Wang, Pengcheng; Duan, Cheng-Guo; Zhu, Xiaohong; Zhu, Jian-Kang

    2014-06-03

    The phytohormone abscisic acid (ABA) regulates plant growth, development, and abiotic stress responses. ABA signaling is mediated by a group of receptors known as the PYR1/PYL/RCAR family, which includes the pyrabactin resistance 1-like protein PYL8. Under stress conditions, ABA signaling activates SnRK2 protein kinases to inhibit lateral root growth after emergence from the primary root. However, even in the case of persistent stress, lateral root growth eventually recovers from inhibition. We showed that PYL8 is required for the recovery of lateral root growth, following inhibition by ABA. PYL8 directly interacted with the transcription factors MYB77, MYB44, and MYB73. The interaction of PYL8 and MYB77 increased the binding of MYB77 to its target MBSI motif in the promoters of multiple auxin-responsive genes. Compared to wild-type seedlings, the lateral root growth of pyl8 mutant seedlings and myb77 mutant seedlings was more sensitive to inhibition by ABA. The recovery of lateral root growth was delayed in pyl8 mutant seedlings in the presence of ABA, and the defect was rescued by exposing pyl8 mutant seedlings to the auxin IAA (3-indoleacetic acid). Thus, PYL8 promotes lateral root growth independently of the core ABA-SnRK2 signaling pathway by enhancing the activities of MYB77 and its paralogs, MYB44 and MYB73, to augment auxin signaling. Copyright © 2014, American Association for the Advancement of Science.

  15. ERECTA-family receptor kinase genes redundantly prevent premature progression of secondary growth in the Arabidopsis hypocotyl.

    Science.gov (United States)

    Ikematsu, Shuka; Tasaka, Masao; Torii, Keiko U; Uchida, Naoyuki

    2017-03-01

    Secondary growth is driven by continuous cell proliferation and differentiation of the cambium that acts as vascular stem cells, producing xylem and phloem to expand vascular tissues laterally. During secondary growth of hypocotyls in Arabidopsis thaliana, the xylem undergoes a drastic phase transition from a parenchyma-producing phase to a fiber-producing phase at the appropriate time. However, it remains to be fully elucidated how progression of secondary growth is properly controlled. We focused on phenotypes of hypocotyl vasculatures caused by double mutation in ERECTA (ER) and ER-LIKE1 (ERL1) receptor-kinase genes to elucidate their roles in secondary growth. ER and ERL1 redundantly suppressed excessive radial growth of the hypocotyl vasculature during secondary growth. ER and ERL1 also prevented premature initiation of the fiber differentiation process mediated by the NAC SECONDARY WALL THICKENING PROMOTING FACTORs in the hypocotyl xylem. Upon floral transition, the hypocotyl xylem gained a competency to respond to GA in a BREVIPEDICELLUS-dependent manner, which was a prerequisite for fiber differentiation. However, even after the floral transition, ER and ERL1 prevented precocious initiation of the GA-mediated fiber formation. Collectively, our findings reveal that ER and ERL1 redundantly prevent premature progression of sequential events in secondary growth. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

  16. Epidermal growth factor receptor expression in laryngeal cancer predicts the effect of hypoxia modification as an additive to accelerated radiotherapy in a randomised controlled trial

    NARCIS (Netherlands)

    Nijkamp, Monique M.; Span, Paul N.; Terhaard, Christiaan H. J.; Doornaert, Patricia A. H.; Langendijk, Johannes A.; van den Ende, Piet L. A.; de Jong, Martin; van der Kogel, Albert J.; Bussink, Johan; Kaanders, Johannes H. A. M.

    2013-01-01

    Accelerated radiotherapy (AR) improves the poor prognosis associated with epidermal growth factor receptor (EGFR) overexpression frequently seen in head and neck carcinomas. Combining AR with carbogen and nicotinamide (ARCON) counteracts enhanced tumour cell proliferation-and hypoxia-related

  17. Epidermal growth factor receptor expression in laryngeal cancer predicts the effect of hypoxia modification as an additive to accelerated radiotherapy in a randomised controlled trial

    NARCIS (Netherlands)

    Nijkamp, M.M.; Span, P.N.; Terhaard, C.H.J.; Doornaert, P.A.; Langendijk, J.A.; Ende, P.L. van den; Jong, M de; Kogel, A.J. van der; Bussink, J.; Kaanders, J.H.A.M.

    2013-01-01

    Accelerated radiotherapy (AR) improves the poor prognosis associated with epidermal growth factor receptor (EGFR) overexpression frequently seen in head and neck carcinomas. Combining AR with carbogen and nicotinamide (ARCON) counteracts enhanced tumour cell proliferation- and hypoxia-related

  18. receptores

    Directory of Open Access Journals (Sweden)

    Salete Regina Daronco Benetti

    2006-01-01

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

  19. Expression of nerve growth factor and its receptors in the uterus of rabbits: functional involvement in prostaglandin synthesis.

    Science.gov (United States)

    Maranesi, M; Parillo, F; Leonardi, L; Rebollar, P G; Alonso, B; Petrucci, L; Gobbetti, A; Boiti, C; Arruda-Alencar, J; Moura, A; Zerani, M

    2016-07-01

    The aim of the present study was to evaluate: (1) the presence of nerve growth factor (NGF), neurotrophic tyrosine kinase receptor 1 (NTRK1), and nerve growth factor receptor (NGFR) in the rabbit uterus; and (2) the in vitro effects of NGF on PGF2α and PGE2 synthesis and on the PGE2-9-ketoreductase (PGE2-9-K) activity by the rabbit uterus. Nerve growth factor, NTRK1, and NGFR were immunolocalized in the luminal and glandular epithelium and stroma cells of the endometrium. reverse transcriptase polymerase chain reaction indicated the presence of messenger RNA for NGF, NTRK1, and NGFR in the uterus. Nerve growth factor increased (P uterus. NGF/NTRK1 increases PGF2α and PGE2 productions by upregulating NOS and PGE2-9-K activities, whereas NGF/NGFR augments only PGF2α secretion, through an intracellular mechanism that is still unknown. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. Hypoxia and prostaglandin E receptor 4 signalling pathways synergise to promote endometrial adenocarcinoma cell proliferation and tumour growth.

    Science.gov (United States)

    Catalano, Rob D; Wilson, Martin R; Boddy, Sheila C; McKinlay, Andrew T M; Sales, Kurt J; Jabbour, Henry N

    2011-05-12

    The prostaglandin endoperoxide synthase (PTGS) pathway is a potent driver of tumour development in humans by enhancing the biosynthesis and signalling of prostaglandin (PG) E(2). PTGS2 expression and PGE(2) biosynthesis is elevated in endometrial adenocarcinoma, however the mechanism whereby PTGS and PGE(2) regulate endometrial tumour growth is unknown. Here we investigated (a) the expression profile of the PGE synthase enzymes (PTGES, PTGES-2, PTGES-3) and PGE receptors (PTGER1-4) in endometrial adenocarcinomas compared with normal endometrium and (b) the role of PTGER4 in endometrial tumorigenesis in vivo. We found elevated expression of PTGES2 and PTGER4 and suppression of PTGER1 and PTGER3 in endometrial adenocarcinomas compared with normal endometrium. Using WT Ishikawa endometrial adenocarcinoma cells and Ishikawa cells stably transfected with the full length PTGER4 cDNA (PTGER4 cells) xenografted in the dorsal flanks of nude mice, we show that PTGER4 rapidly and significantly enhances tumour growth rate. Coincident with enhanced PTGER4-mediated tumour growth we found elevated expression of PTGS2 in PTGER4 xenografts compared with WT xenografts. Furthermore we found that the augmented growth rate of the PTGER4 xenografts was not due to enhanced angiogenesis, but regulated by an increased proliferation index and hypoxia. In vitro, we found that PGE(2) and hypoxia independently induce expression of PTGER4 indicating two independent pathways regulating prostanoid receptor expression. Finally we have shown that PGE(2) and hypoxia synergise to promote cellular proliferation of endometrial adenocarcinoma cells.

  1. A single amino acid substitution is sufficient to modify the mitogenic properties of the epidermal growth factor receptor to resemble that of gp185erbB-2

    DEFF Research Database (Denmark)

    Di Fiore, P P; Helin, K; Kraus, M H

    1992-01-01

    The epidermal growth factor (EGF) receptor (EGFR) and the erbB-2 gene product, gp185erbB-2, exhibit distinct abilities to stimulate mitogenesis in different target cells. By using chimeric molecules between these two receptors, we have previously shown that their intracellular juxtamembrane regio...

  2. Rat insulinoma cells express both a 115-kDa growth hormone receptor and a 95-kDa prolactin receptor structurally related to the hepatic receptors

    DEFF Research Database (Denmark)

    Møldrup, Annette; Billestrup, N; Nielsen, Jens Høiriis

    1990-01-01

    Insulin-producing rat islet RIN-5AH tumor cells express multiple binding sites for human growth hormone (hGH). The effect of rat growth hormone (rGH), rat prolactin (rPRL), and human placental lactogen (hPL) on the binding of 125I-labeled hGH (125I-hGH) to RIN-5AH cells revealed the presence...

  3. [Differences in dynamics of insulin and insulin-like growth I (IGF-I) receptors internalization in isolated rat hepatocytes].

    Science.gov (United States)

    Kolychev, A P; Ternovskaya, E E; Arsenieva, A V; Shapkina, E V

    2013-01-01

    Insulin and IGF-I are two related peptides performing in the mammalian body functionally different roles of the metabolic and growth hormones, respectively. Internalization of the insulin-receptor complex (IRC) is the most important chain of mechanism of the action of hormone. To elucidate differences in the main stages of internalization of the two related hormones, the internalization dynamics of 125I-insulin and 125I-IGF-I was traced in isolated rat hepatocytes at 37 and 12 degrees C. There were established marked differences in the process of internalization of labeled hormones, which is stimulated by insulin and IGF-I. At 37 degrees C the insulin-stimulated internalization, unlike the process initiated by IGF-I, did not reach the maximal level for 1 h of incubation. However, essential differences in the internalization course of these two related peptide were obvious at the temperature of 12 degrees C. The internalization level of insulin receptors at 12 degrees C decreased by one third in spite of a significant increase of the insulin receptor binding on the hepatocytes plasma membrane. At 12 degrees C a slight decrease of the proportion of intracellular 125I-IGF-I correlated with a decrease in the 125I-IGF-I binding to receptors on the cell membrane. Internalization of IGF-I receptors was not affected by low temperature, as neither its level, nor the rate changed at 12 degrees C. The paradoxical decrease of the insulin-stimulated internalization at low temperature seems to represent a peculiar "inhibition mechanism" of immersion of IRC into the cell, which leads to accumulation of the complexes on the cell surface and possibly to a readjustment of the insulin biological activity. The resistance of internalization of the IGF-I receptor to cold seems to be related to the more ancient origin of this mechanism in the poikilothermal vertebrates.

  4. Functional properties of an isolated αβ heterodimeric human placenta insulin-like growth factor 1 receptor complex

    International Nuclear Information System (INIS)

    Feltz, S.M.; Swanson, M.L.; Wemmie, J.A.; Pessin, J.E.

    1988-01-01

    Treatment of human placenta membranes at pH 8.5 in the presence of 2.0 mM dithiothreitol (DTT) for 5 min, followed by the simultaneous removal of the DTT and pH adjustment of pH 7.6, resulted in the formation of a functional αβ heterodimeric insulin-like growth factor 1 (IGF-1) receptor complex from the native α 2 β 2 heterotetrameric disulfide-linked state. The membrane-bound αβ heterodimeric complex displayed similar curvilinear 125 I-IGF-1 equilibrium binding compared to the α 2 β 2 heterotetrameric complex. 125 I-IGF-1 binding to both the isolated α 2 β 2 heterotetrameric and αβ heterodimeric complexes demonstrated a marked straightening of the Scatchard plots, compared to the placenta membrane-bound IGF-1 receptors, with a 2-fold increase in the high-affinity binding component. IGF-1 stimulation of IGF-1 receptor autophosphorylation indicated that the ligand-dependent activation of αβ heterodimeric protein kinase activity occurred concomitant with the reassociation into a covalent α 2 β 2 heterotetrameric state. These data demonstrate that (i) a combination of alkaline pH and DTT treatment of human placenta membranes results in the formation of an αβ heterodimeric IGF-1 receptor complex, (ii) unlike the insulin receptor, high-affinity homogeneous IGF-1 binding occurs in both the α 2 β 2 heterotetrameric and αβ heterodimeric complexes, and (iii) IGF-1-dependent autophosphorylation of the αβ heterodimeric IGF-1 receptor complex correlates wit an IGF-1 dependent covalent reassociation into an α 2 β 2 heterotetrameric disulfide-linked state

  5. Modelling of the disulphide-swapped isomer of human insulin-like growth factor-1: implications for receptor binding.

    Science.gov (United States)

    Gill, R; Verma, C; Wallach, B; Ursø, B; Pitts, J; Wollmer, A; De Meyts, P; Wood, S

    1999-04-01

    Insulin-like growth factor-1 (IGF-1) is a serum protein which unexpectedly folds to yield two stable tertiary structures with different disulphide connectivities; native IGF-1 [18-61,6-48,47-52] and IGF-1 swap [18-61,6-47, 48-52]. Here we demonstrate in detail the biological properties of recombinant human native IGF-1 and IGF-1 swap secreted from Saccharomyces cerevisiae. IGF-1 swap had a approximately 30 fold loss in affinity for the IGF-1 receptor overexpressed on BHK cells compared with native IGF-1. The parallel increase in dose required to induce negative cooperativity together with the parallel loss in mitogenicity in NIH 3T3 cells implies that disruption of the IGF-1 receptor binding interaction rather than restriction of a post-binding conformational change is responsible for the reduction in biological activity of IGF-1 swap. Interestingly, the affinity of IGF-1 swap for the insulin receptor was approximately 200 fold lower than that of native IGF-1 indicating that the binding surface complementary to the insulin receptor (or the ability to attain it) is disturbed to a greater extent than that to the IGF-1 receptor. A 1.0 ns high-temperature molecular dynamics study of the local energy landscape of IGF-1 swap resulted in uncoiling of the first A-region alpha-helix and a rearrangement in the relative orientation of the A- and B-regions. The model of IGF-1 swap is structurally homologous to the NMR structure of insulin swap and CD spectra consistent with the model are presented. However, in the model of IGF-1 swap the C-region has filled the space where the first A-region alpha-helix has uncoiled and this may be hindering interaction of Val44 with the second insulin receptor binding pocket.

  6. Activation of the kinin B1 receptor attenuates melanoma tumor growth and metastasis.

    Directory of Open Access Journals (Sweden)

    Patricia Dillenburg-Pilla

    Full Text Available Melanoma is a very aggressive tumor that does not respond well to standard therapeutic approaches, such as radio- and chemotherapies. Furthermore, acquiring the ability to metastasize in melanoma and many other tumor types is directly related to incurable disease. The B1 kinin receptor participates in a variety of cancer-related pathophysiological events, such as inflammation and angiogenesis. Therefore, we investigated whether this G protein-coupled receptor plays a role in tumor progression. We used a murine melanoma cell line that expresses the kinin B1 receptor and does not express the kinin B2 receptor to investigate the precise contribution of activation of the B1 receptor in tumor progression and correlated events using various in vitro and in vivo approaches. Activation of the kinin B1 receptor in the absence of B2 receptor inhibits cell migration in vitro and decreases tumor formation in vivo. Moreover, tumors formed from cells stimulated with B1-specific agonist showed several features of decreased aggressiveness, such as smaller size and infiltration of inflammatory cells within the tumor area, higher levels of pro-inflammatory cytokines implicated in the host anti-tumor immune response, lower number of cells undergoing mitosis, a poorer vascular network, no signs of invasion of surrounding tissues or metastasis and increased animal survival. Our findings reveal that activation of the kinin B1 receptor has a host protective role during murine melanoma tumor progression, suggesting that the B1 receptor could be a new anti-tumor GPCR and provide new opportunities for therapeutic targeting.

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

    Directory of Open Access Journals (Sweden)

    Hembrough Todd

    2012-05-01

    Full Text Available Abstract Background Analysis of key therapeutic targets such as epidermal growth factor receptor (EGFR in clinical tissue samples is typically done by immunohistochemistry (IHC and is only subjectively quantitative through a narrow dynamic range. The development of a standardized, highly-sensitive, linear, and quantitative assay for EGFR for use in patient tumor tissue carries high potential for identifying those patients most likely to benefit from EGFR-targeted therapies. Methods A mass 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

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

    Directory of Open Access Journals (Sweden)

    John G Koland

    2014-01-01

    Full Text Available 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

  9. Role of receptors for epidermal growth factor and insulin-like growth factors I and II in the differentiation of rat mammary glands from lactogenesis I to lactogenesis II.

    Science.gov (United States)

    Bussmann, L E; Bussmann, I M; Charreau, E H

    1996-07-01

    In addition to ovarian steroids and lactogenic hormones from the placenta and pituitary, growth factors control the growth and differentiation of mammary glands. Lactogenesis II at the end of pregnancy is under the control of progesterone. Ovariectomy results in a significant decrease in the number of receptors for epidermal growth factor (EGF) and insulin-like growth factor I (IGF-I) and an increase in IGF-II binding sites in mammary gland acini of rats, without affecting the affinity for their respective ligand. Although concentrations of EGF, IGF-I and IGF-II receptors are regulated by oestradiol and progesterone, replacement treatment with ovarian steroids after ovariectomy showed that receptor concentrations do not mediate the restraint on lactogenesis. Progesterone treatment, which inhibits the onset of lactogenesis II, did not restore EGF receptor concentrations to control values, and the presence of oestradiol was required to reverse the effect of ovariectomy. Oestradiol, which potentiates the effect of ovariectomy on milk synthesis, increases IGF-I receptor concentrations. IGF-II receptor concentrations, after the different steroid treatments, were consistent with the steroid effect on milk synthesis. The changes observed in the concentrations of these growth factor receptors at the onset of mammary gland secretion are not considered to affect the progesterone block to lactogenesis II, but rather are a consequence of the shift of the hormonal and, hence, physiological status of the gland.

  10. Growth hormone secretagogue receptor (GHS-R1a) knockout mice exhibit improved spatial memory and deficits in contextual memory.

    Science.gov (United States)

    Albarran-Zeckler, Rosie G; Brantley, Alicia Faruzzi; Smith, Roy G

    2012-06-15

    Although the hormone ghrelin is best known for its stimulatory effect on appetite and regulation of growth hormone release, it is also reported to have beneficial effects on learning and memory formation in mice. Nevertheless, controversy exists about whether endogenous ghrelin acts on its receptors in extra-hypothalamic areas of the brain. The ghrelin receptor (GHS-R1a) is co-expressed in neurons that express dopamine receptor type-1 (DRD1a) and type-2 (DRD2), and we have shown that a subset of GHS-R1a, which are not occupied by the agonist (apo-GHSR1a), heterodimerize with these two receptors to regulate dopamine signaling in vitro and in vivo. To determine the consequences of ghsr ablation on brain function, congenic ghsr -/- mice on the C57BL6/J background were subjected to a battery of behavioral tests. We show that the ghsr -/- mice exhibit normal balance, movement, coordination, and pain sensation, outperform ghsr +/+ mice in the Morris water maze, but show deficits in contextual fear conditioning. Copyright © 2012 Elsevier B.V. All rights reserved.

  11. Cell cycle phase-specific surface expression of nerve growth factor receptors TrkA and p75(NTR).

    Science.gov (United States)

    Urdiales, J L; Becker, E; Andrieu, M; Thomas, A; Jullien, J; van Grunsven, L A; Menut, S; Evan, G I; Martín-Zanca, D; Rudkin, B B

    1998-09-01

    Expression of the nerve growth factor (NGF) receptors TrkA and p75(NTR) was found to vary at the surface of PC12 cells in a cell cycle phase-specific manner. This was evidenced by using flow cytometric and microscopic analysis of cell populations labeled with antibodies to the extracellular domains of both receptors. Differential expression of these receptors also was evidenced by biotinylation of surface proteins and Western analysis, using antibodies specific for the extracellular domains of TrkA and p75(NTR). TrkA is expressed most strongly at the cell surface in M and early G1 phases, whereas p75(NTR) is expressed mainly in late G1, S, and G2 phases. This expression reflects the molecular and cellular responses to NGF in specific phases of the cell cycle; in the G1 phase NGF elicits both the anti-mitogenic effect, i.e., inhibition of the G1 to S transition, and the differentiation response whereas a survival effect is provoked elsewhere in the cell cycle. A model is proposed relating these responses to the surface expression of the two receptors. These observations open the way for novel approaches to the investigation of the mechanism of NGF signal transduction.

  12. Common mutations in the fibroblast growth factor receptor 3 (FGFR 3) gene account for achondroplasia, hypochondroplasia, and thanatophoric dwarfism

    Energy Technology Data Exchange (ETDEWEB)

    Bonaventure, J.; Rousseau, F.; Legeai-Mallet, L.; LeMerrer, M.; Munnich, A.; Maroteaux, P. [INSERM, Paris (France)

    1996-05-03

    The mapping of the achondroplasia locus to the short arm of chromosome 4 and the subsequent identification of a recurrent missense mutation (G380R) in the fibroblast growth factor receptor 3 (FGFR-3) gene has been followed by the detection of common FGFR-3 mutations in two clinically related disorders: thanatophoric dwarfism (types I and II) and hypochondroplasia. The relative clinical homogeneity of achondroplasia was substantiated by demonstration of its genetic homogeneity as more than 98% of all patients hitherto reported exhibit mutations in the transmembrane receptor domain. Although most hypochondroplasia cases were accounted for by a recurrent missense substitution (N540K) in the first tyrosine kinase (TK 1) domain of the receptor, a significant proportion (40%) of our patients did not harbor the N540K mutation and three hypochondroplasia families were not linked to the FGFR-3 locus, thus supporting clinical heterogeneity of this condition. In thanatophoric dwarfism (TD), a recurrent FGFR-3 mutation located in the second tyrosine kinase (TK 2) domain of the receptor was originally detected in 100% of TD II cases; in our series, seven distinct mutations in three different protein domains were identified in 25 of 26 TD I patients, suggesting that TD, like achondroplasia, is a genetically homogenous skeletal disorder. 31 refs., 4 figs., 2 tabs.

  13. Structural and functional divergence of growth hormone-releasing hormone receptors in early sarcopterygians: lungfish and Xenopus.

    Directory of Open Access Journals (Sweden)

    Janice K V Tam

    Full Text Available The evolutionary trajectories of growth hormone-releasing hormone (GHRH receptor remain enigmatic since the discovery of physiologically functional GHRH-GHRH receptor (GHRHR in non-mammalian vertebrates in 2007. Interestingly, subsequent studies have described the identification of a GHRHR(2 in chicken in addition to the GHRHR and the closely related paralogous receptor, PACAP-related peptide (PRP receptor (PRPR. In this article, we provide information, for the first time, on the GHRHR in sarcopterygian fish and amphibians by the cloning and characterization of GHRHRs from lungfish (P. dolloi and X. laevis. Sequence alignment and phylogenetic analyses demonstrated structural resemblance of lungfish GHRHR to their mammalian orthologs, while the X. laevis GHRHR showed the highest homology to GHRHR(2 in zebrafish and chicken. Functionally, lungfish GHRHR displayed high affinity towards GHRH in triggering intracellular cAMP and calcium accumulation, while X. laevis GHRHR(2 was able to react with both endogenous GHRH and PRP. Tissue distribution analyses showed that both lungfish GHRHR and X. laevis GHRHR(2 had the highest expression in brain, and interestingly, X. laevis(GHRHR2 also had high abundance in the reproductive organs. These findings, together with previous reports, suggest that early in the Sarcopterygii lineage, GHRHR and PRPR have already established diverged and specific affinities towards their cognate ligands. GHRHR(2, which has only been found in xenopus, zebrafish and chicken hitherto, accommodates both GHRH and PRP.

  14. [Methodology comparison and influence factors analysis of epidermal growth factor receptor mutation detection].

    Science.gov (United States)

    Qian, Xiaoyan; Wang, Shuai; Shen, Yinchen; Wu, Di; Zhang, Zhishang; Feng, Yun; Han, Xiaohong; Shi, Yuankai

    2015-01-13

    To compare two different methods in detecting epidermal growth factor receptor (EGFR) mutation status of non-small cell lung cancer (NSCLC) , and investing the influences of different conserving methods in DNA quantity, quality and detecting results of formalin-fixed paraffin embedded (FFPE) tissue samples. One hundred and fifty FFPE samples of advanced NSCLC were collected in Cancer Institute/Hospital, Chinese Academy of Medical Sciences from November 2010 to August 2011. Both scorpions amplification refractory mutation system (scorpions ARMS) and direct sequencing were used to detect EGFR mutation in exon 18, 19, 20 and 21, together analyzed the differences between these two methods. Samples with inconsistent results were collected clinical treatment and survival information for further analysis. Extracted DNA from 30 FFPE samples and conserved at -20 °C for 3 years, meanwhile the same 30 FFPE samples DNA were extracted after conserving for 3 years. The DNA quantity, quality and testing results of the two conserving methods were compared. The detection success rate of Scorpions ARMS (100%) was higher than direct sequencing (87.3%), with statistical significance ( χ(2) = 20.28, P < 0.05). The con