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Sample records for receptor igf-1r signaling

  1. Impaired IGF1R signaling in cells expressing longevity-associated human IGF1R alleles

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    Tazearslan, Cagdas; Huang, Jing; Barzilai, Nir; Suh, Yousin

    2011-01-01

    Dampening of insulin/insulin like growth factor-1 (IGF1) signaling results in extension of lifespan in invertebrate as well as murine models. The impact of this evolutionarily conserved pathway on modulation of human lifespan remains unclear. We previously identified two IGF1R mutations (Ala-37-Thr and Arg-407-His) that are enriched in Ashkenazi Jewish centenarians as compared to younger controls and are associated with reduced activity of the IGF1 receptor as measured in immortalized lymphoc...

  2. Compensatory insulin receptor (IR) activation on inhibition of insulin-like growth factor-1 receptor (IGF-1R): rationale for cotargeting IGF-1R and IR in cancer.

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    Buck, Elizabeth; Gokhale, Prafulla C; Koujak, Susan; Brown, Eric; Eyzaguirre, Alexandra; Tao, Nianjun; Rosenfeld-Franklin, Maryland; Lerner, Lorena; Chiu, M Isabel; Wild, Robert; Epstein, David; Pachter, Jonathan A; Miglarese, Mark R

    2010-10-01

    Insulin-like growth factor-1 receptor (IGF-1R) is a receptor tyrosine kinase (RTK) and critical activator of the phosphatidylinositol 3-kinase-AKT pathway. IGF-1R is required for oncogenic transformation and tumorigenesis. These observations have spurred anticancer drug discovery and development efforts for both biological and small-molecule IGF-1R inhibitors. The ability for one RTK to compensate for another to maintain tumor cell viability is emerging as a common resistance mechanism to antitumor agents targeting individual RTKs. As IGF-1R is structurally and functionally related to the insulin receptor (IR), we asked whether IR is tumorigenic and whether IR-AKT signaling contributes to resistance to IGF-1R inhibition. Both IGF-1R and IR(A) are tumorigenic in a mouse mammary tumor model. In human tumor cells coexpressing IGF-1R and IR, bidirectional cross talk was observed following either knockdown of IR expression or treatment with a selective anti-IGF-1R antibody, MAB391. MAB391 treatment resulted in a compensatory increase in phospho-IR, which was associated with resistance to inhibition of IRS1 and AKT. In contrast, treatment with OSI-906, a small-molecule dual inhibitor of IGF-1R/IR, resulted in enhanced reduction in phospho-IRS1/phospho-AKT relative to MAB391. Insulin or IGF-2 activated the IR-AKT pathway and decreased sensitivity to MAB391 but not to OSI-906. In tumor cells with an autocrine IGF-2 loop, both OSI-906 and an anti-IGF-2 antibody reduced phospho-IR/phospho-AKT, whereas MAB391 was ineffective. Finally, OSI-906 showed superior efficacy compared with MAB391 in human tumor xenograft models in which both IGF-1R and IR were phosphorylated. Collectively, these data indicate that cotargeting IGF-1R and IR may provide superior antitumor efficacy compared with targeting IGF-1R alone.

  3. H2O2 attenuates IGF-1R tyrosine phosphorylation and its survival signaling properties in neuronal cells via NR2B containing NMDA receptor.

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    Zeng, Zhiwen; Wang, Dejun; Gaur, Uma; Rifang, Liao; Wang, Haitao; Zheng, Wenhua

    2017-09-12

    Impairment of insulin-like growth factor I (IGF-I) signaling plays an important role in the development of neurodegeneration. In the present study, we investigated the effect of H 2 O 2 on the survival signaling of IGF-1 and its underlying mechanisms in human neuronal cells SH-SY5Y. Our results showed that IGF-1 promoted cell survival and stimulated phosphorylation of IGF-1R as well as its downstream targets like AKT and ERK1/2 in these cells. Meanwhile, these effects of IGF-1 were abolished by H 2 O 2 at 200μM concentration which did not cause any significant toxicity to cells itself in our experiments. Moreover, studies using various glutamate receptor subtype antagonists displayed that N-methyl-D -aspartate (NMDA) receptor antagonist dizocilpine maleate (MK-801) blocked the effects of H 2 O 2 , whereas other glutamate receptor subtype antagonists, such as non-NMDA receptor antagonist 6,7-dinitroquinoxaline-2,3-dione (DNQX), metabolic glutamate receptor antagonists LY341495 and CPCCOEt, had no effect. Further studies revealed that NR2B-containing NMDARs are responsible for these effects as its effects were blocked by pharmacological inhibitor Ro25-698 or specific siRNA for NR2B, but not NR2A. Finally, our data also showed that Ca 2+ influx contributes to the effects of H 2 O 2 . Similar results were obtained in primary cultured cortical neurons. Taken together, the results from the present study suggested that H 2 O 2 attenuated IGF-1R tyrosine phosphorylation and its survival signaling properties via NR2B containing NMDA receptors and Ca 2+ influx in SH-SY5Y cells. Therefore, NMDAR antagonists, especially NR2B-selective ones, combined with IGF-1 may serve as an alternative therapeutic agent for oxidative stress related neurodegenerative disease.

  4. Pancreatic Fibroblasts Stimulate the Motility of Pancreatic Cancer Cells through IGF1/IGF1R Signaling under Hypoxia.

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    Toshiki Hirakawa

    Full Text Available Pancreatic ductal adenocarcinoma (PDAC is characterized by its hypovascularity, with an extremely poor prognosis because of its highly invasive nature. PDAC proliferates with abundant stromal cells, suggesting that its invasive activity might be controlled by intercellular interactions between cancer cells and fibroblasts. Using four PDAC cell lines and two pancreas cancer-associated fibroblasts (CAFs, the expression of insulin-like growth factor-1 (IGF1 and IGF1 receptor (IGF1R was evaluated by RT-PCR, FACScan, western blot, or ELISA. Correlation between IGF1R and the hypoxia marker carbonic anhydrase 9 (CA9 was examined by immunohistochemical staining of 120 pancreatic specimens. The effects of CAFs, IGF1, and IGF1R inhibitors on the motility of cancer cells were examined by wound-healing assay or invasion assay under normoxia (20% O2 and hypoxia (1% O2. IGF1R expression was significantly higher in RWP-1, MiaPaCa-2, and OCUP-AT cells than in Panc-1 cells. Hypoxia increased the expression level of IGF1R in RWP-1, MiaPaCa-2, and OCUP-AT cells. CA9 expression was correlated with IGF1R expression in pancreatic specimens. CAFs produced IGF1 under hypoxia, but PDAC cells did not. A conditioned medium from CAFs, which expressed αSMA, stimulated the migration and invasion ability of MiaPaCa-2, RWP-1, and OCUP-AT cells. The motility of all PDAC cells was greater under hypoxia than under normoxia. The motility-stimulating ability of CAFs was decreased by IGF1R inhibitors. These findings might suggest that pancreas CAFs stimulate the invasion activity of PDAC cells through paracrine IGF1/IGF1R signaling, especially under hypoxia. Therefore the targeting of IGF1R signaling might represent a promising therapeutic approach in IGF1R-dependent PDAC.

  5. Igf1r signaling is indispensable for preimplantation development and is activated via a novel function of E-cadherin.

    Directory of Open Access Journals (Sweden)

    Ivan Bedzhov

    Full Text Available Insulin-like growth factor I receptor (Igf1r signaling controls proliferation, differentiation, growth, and cell survival in many tissues; and its deregulated activity is involved in tumorigenesis. Although important during fetal growth and postnatal life, a function for the Igf pathway during preimplantation development has not been described. We show that abrogating Igf1r signaling with specific inhibitors blocks trophectoderm formation and compromises embryo survival during murine blastocyst formation. In normal embryos total Igf1r is present throughout the membrane, whereas the activated form is found exclusively at cell contact sites, colocalizing with E-cadherin. Using genetic domain switching, we show a requirement for E-cadherin to maintain proper activation of Igf1r. Embryos expressing exclusively a cadherin chimera with N-cadherin extracellular and E-cadherin intracellular domains (NcEc fail to form a trophectoderm and cells die by apoptosis. In contrast, homozygous mutant embryos expressing a reverse-structured chimera (EcNc show trophectoderm survival and blastocoel cavitation, indicating a crucial and non-substitutable role of the E-cadherin ectodomain for these processes. Strikingly, blastocyst formation can be rescued in homozygous NcEc embryos by restoring Igf1r signaling, which enhances cell survival. Hence, perturbation of E-cadherin extracellular integrity, independent of its cell-adhesion function, blocked Igf1r signaling and induced cell death in the trophectoderm. Our results reveal an important and yet undiscovered function of Igf1r during preimplantation development mediated by a unique physical interaction between Igf1r and E-cadherin indispensable for proper receptor activation and anti-apoptotic signaling. We provide novel insights into how ligand-dependent Igf1r activity is additionally gated to sense developmental potential in utero and into a bifunctional role of adhesion molecules in contact formation and signaling.

  6. A chimeric receptor of the insulin-like growth factor receptor type 1 (IGFR1) and a single chain antibody specific to myelin oligodendrocyte glycoprotein activates the IGF1R signalling cascade in CG4 oligodendrocyte progenitors.

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    Annenkov, Alexander; Rigby, Anne; Amor, Sandra; Zhou, Dun; Yousaf, Nasim; Hemmer, Bernhard; Chernajovsky, Yuti

    2011-08-01

    In order to generate neural stem cells with increased ability to survive after transplantation in brain parenchyma we developed a chimeric receptor (ChR) that binds to myelin oligodendrocyte glycoprotein (MOG) via its ectodomain and activates the insulin-like growth factor receptor type 1 ‎‎(IGF1R) signalling cascade. Activation of this pro-survival pathway in response to ligand broadly available in the brain might increase neuroregenerative potential of transplanted precursors. The ChR was produced by fusing a MOG-specific single ‎chain antibody with the extracellular boundary of the IGF1R transmembrane segment. The ChR is expressed on the cellular surface, predominantly as a monomer, and is not N-glycosylated. To show MOG-dependent functionality of the ChR, neuroblastoma cells B104 expressing this ChR were stimulated with monolayers of cells expressing recombinant MOG. The ChR undergoes MOG-dependent tyrosine phosphorylation and homodimerisation. It promotes insulin and IGF-independent growth of the oligodendrocyte progenitor cell line CG4. The proposed mode of the ChR activation is by MOG-induced dimerisation which promotes kinase domain transphosphorylation, by-passing the requirement of conformation changes known to be important for IGF1R activation. Another ChR, which contains a segment of the β-chain ectodomain, was produced in an attempt to recapitulate some of these conformational changes, but proved non-functional. 2011 Elsevier B.V. All rights reserved.

  7. A chimeric receptor of the insulin-like growth factor receptor type 1 (IGFR1) and a single chain antibody specific to myelin oligodendrocyte glycoprotein activates the IGF1R signalling cascade in CG4 oligodendrocyte progenitors

    NARCIS (Netherlands)

    Annenkov, A.; Rigby, A.; Amor, S.; Zhou, D.M.; Yousaf, N.; Hemmer, B.; Chernajovsky, Y.

    2011-01-01

    In order to generate neural stem cells with increased ability to survive after transplantation in brain parenchyma we developed a chimeric receptor (ChR) that binds to myelin oligodendrocyte glycoprotein (MOG) via its ectodomain and activates the insulin-like growth factor receptor type 1 (IGF1R)

  8. Interference of silibinin with IGF-1R signalling pathways protects human epidermoid carcinoma A431 cells from UVB-induced apoptosis

    International Nuclear Information System (INIS)

    Liu, Weiwei; Otkur, Wuxiyar; Li, Lingzhi; Wang, Qiong; He, Hao; Zang, Linghe; Hayashi, Toshihiko; Tashiro, Shin-ichi; Onodera, Satoshi; Xia, Mingyu; Ikejima, Takashi

    2013-01-01

    Highlights: ► Silibinin protects A431 cells from UVB irradiation-induced apoptosis. ► Up-regulation of the IGF-1R-JNK/ERK pathways by UVB induces cell apoptosis. ► Silibinin inhibits IGF-1R pathways to repress caspase-8-mediated apoptosis. -- Abstract: Ultraviolet B (UVB) from sunlight is a major cause of cutaneous lesion. Silibinin, a traditional hepatic protectant, elicits protective effects against UVB-induced cellular damage. In A431 cells, the insulin-like growth factor-1 receptor (IGF-1R) was markedly up-regulated by UVB irradiation. The activation of the IGF-1R signalling pathways contributed to apoptosis of the cells rather than rescuing the cells from death. Up-regulated IGF-1R stimulated downstream mitogen-activated protein kinases (MAPKs), such as c-Jun N-terminal kinases (JNK) and extracellular signal-regulated protein kinases 1/2 (ERK1/2). The subsequent activation of caspase-8 and caspase-3 led to apoptosis. The activation of IGF-1R signalling pathways is the cause of A431 cell death. The pharmacological inhibitors and the small interfering RNA (siRNA) targeting IGF-1R suppressed the downstream activation of JNK/ERK-caspases to help the survival of the UVB-irradiated A431 cells. Indeed, silibinin treatment suppressed the IGF-1R-JNK/ERK pathways and thus protected the cells from UVB-induced apoptosis

  9. The viral G protein-coupled receptor ORF74 unmasks phospholipase C signaling of the receptor tyrosine kinase IGF-1R.

    NARCIS (Netherlands)

    de Munnik, S.M.; van der Lee, R.; Velders, D.M.; van Offenbeek, J.; Smits-de Vries, L.; Leurs, R.; Smit, M.J.; Vischer, H.F.

    2016-01-01

    Kaposi's sarcoma-associated herpesvirus (KSHV) encodes the constitutively active G protein-coupled receptor ORF74, which is expressed on the surface of infected host cells and has been linked to the development of the angioproliferative tumor Kaposi's sarcoma. Furthermore, the insulin-like growth

  10. IGF-1R signaling in chondrocytes modulates growth plate development by interacting with the PTHrP/Ihh pathway.

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    Wang, Yongmei; Cheng, Zhiqiang; Elalieh, Hashem Z; Nakamura, Eiichiro; Nguyen, Minh-Thanh; Mackem, Susan; Clemens, Thomas L; Bikle, Daniel D; Chang, Wenhan

    2011-07-01

    Systemic derangements and perinatal death of generalized insulin-like growth factor 1 (IGF-1) and IGF-1 receptor (IGF-1R) knockout mice preclude definitive assessment of IGF-1R actions in growth-plate (GP) chondrocytes. We generated cartilage-specific Igf1r knockout ((Cart) Igf1r(-/-)) mice to investigate local control of chondrocyte differentiation in the GP by this receptor. These mice died shortly after birth and showed disorganized chondrocyte columns, delayed ossification and vascular invasion, decreased cell proliferation, increased apoptosis, and increased expression of parathyroid hormone-related protein (Pthrp) RNA and protein in their GPs. The increased Pthrp expression in the knockout GPs likely was due to an increase in gene transcription, as determined by the increased activity of a LacZ reporter that was inserted downstream of the endogenous PTHrP promoter and bred into the knockout mice. To circumvent the early death of (Cart) Igf1r(-/-) mice and investigate the role of IGF-1R during postnatal growth, we made tamoxifen (Tam)-inducible, cartilage-specific Igf1r knockout ((TamCart) Igf1r(-/-)) mice. At 2 weeks of age and 7 to 8 days after Tam injection, the (TamCart) Igf1r(-/-) mice showed growth retardation with a disorganized GP, reduced chondrocyte proliferation, decreased type 2 collagen and Indian Hedgehog (Ihh) expression, but increased expression of PTHrP. Consistent with in vivo observations, in vitro knockout of the Igf1r gene by adenoviral expression of Cre recombinase suppressed cell proliferation, promoted apoptosis, and increased Pthrp expression. Our data indicate that the IGF-1R in chondrocytes controls cell growth, survival, and differentiation in embryonic and postnatal GPs in part by suppression of Pthrp expression. Copyright © 2011 American Society for Bone and Mineral Research.

  11. SUMO-modified insulin-like growth factor 1 receptor (IGF-1R) increases cell cycle progression and cell proliferation.

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    Lin, Yingbo; Liu, Hongyu; Waraky, Ahmed; Haglund, Felix; Agarwal, Prasoon; Jernberg-Wiklund, Helena; Warsito, Dudi; Larsson, Olle

    2017-10-01

    Increasing number of studies have shown nuclear localization of the insulin-like growth factor 1 receptor (nIGF-1R) in tumor cells and its links to adverse clinical outcome in various cancers. Any obvious cell physiological roles of nIGF-1R have, however, still not been disclosed. Previously, we reported that IGF-1R translocates to cell nucleus and modulates gene expression by binding to enhancers, provided that the receptor is SUMOylated. In this study, we constructed stable transfectants of wild type IGF1R (WT) and triple-SUMO-site-mutated IGF1R (TSM) using igf1r knockout mouse fibroblasts (R-). Cell clones (R-WT and R-TSM) expressing equal amounts of IGF-1R were selected for experiments. Phosphorylation of IGF-1R, Akt, and Erk upon IGF-1 stimulation was equal in R-WT and R-TSM. WT was confirmed to enter nuclei. TSM did also undergo nuclear translocation, although to a lesser extent. This may be explained by that TSM heterodimerizes with insulin receptor, which is known to translocate to cell nuclei. R-WT proliferated substantially faster than R-TSM, which did not differ significantly from the empty vector control. Upon IGF-1 stimulation G1-S-phase progression of R-WT increased from 12 to 38%, compared to 13 to 20% of R-TSM. The G1-S progression of R-WT correlated with increased expression of cyclin D1, A, and CDK2, as well as downregulation of p27. This suggests that SUMO-IGF-1R affects upstream mechanisms that control and coordinate expression of cell cycle regulators. Further studies to identify such SUMO-IGF-1R dependent mechanisms seem important. © 2017 The Authors. Journal of Cellular Physiology Published by Wiley Periodicals Inc.

  12. Targeted Morphoproteomic Profiling of Ewing's Sarcoma Treated with Insulin-Like Growth Factor 1 Receptor (IGF1R) Inhibitors: Response/Resistance Signatures

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    Subbiah, Vivek; Naing, Aung; Brown, Robert E.; Chen, Helen; Doyle, Laurence; LoRusso, Patricia; Benjamin, Robert; Anderson, Pete; Kurzrock, Razelle

    2011-01-01

    Background Insulin-like growth factor 1 receptor (IGF1R) targeted therapies have resulted in responses in a small number of patients with advanced metastatic Ewing's sarcoma. We performed morphoproteomic profiling to better understand response/resistance mechanisms of Ewing's sarcoma to IGF1R inhibitor-based therapy. Methodology/Principal Findings This pilot study assessed two patients with advanced Ewing's sarcoma treated with IGF1R antibody alone followed by combined IGF1R inhibitor plus mammalian target of rapamycin (mTOR) inhibitor treatment once resistance to single-agent IGF1R inhibitor developed. Immunohistochemical probes were applied to detect p-mTOR (Ser2448), p-Akt (Ser473), p-ERK1/2 (Thr202/Tyr204), nestin, and p-STAT3 (Tyr 705) in the original and recurrent tumor. The initial remarkable radiographic responses to IGF1R-antibody therapy was followed by resistance and then response to combined IGF1R plus mTOR inhibitor therapy in both patients, and then resistance to the combination regimen in one patient. In patient 1, upregulation of p-Akt and p-mTOR in the tumor that relapsed after initial response to IGF1R antibody might explain the resistance that developed, and the subsequent response to combined IGF1R plus mTOR inhibitor therapy. In patient 2, upregulation of mTOR was seen in the primary tumor, perhaps explaining the initial response to the IGF1R and mTOR inhibitor combination, while the resistant tumor that emerged showed activation of the ERK pathway as well. Conclusion/Significance Morphoproteomic analysis revealed that the mTOR pathway was activated in these two patients with advanced Ewing's sarcoma who showed response to combined IGF1R and mTOR inhibition, and the ERK pathway in the patient in whom resistance to this combination emerged. Our pilot results suggests that morphoproteomic assessment of signaling pathway activation in Ewing's sarcoma merits further investigation as a guide to understanding response and resistance signatures. PMID

  13. Overexpression of decorin promoted angiogenesis in diabetic cardiomyopathy via IGF1R-AKT-VEGF signaling.

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    Lai, Jinsheng; Chen, Fuqiong; Chen, Jing; Ruan, Guoran; He, Mengying; Chen, Chen; Tang, Jiarong; Wang, Dao Wen

    2017-03-14

    Microcirculatory dysfunction is believed to play an important role in diabetic cardiomyopathy. The small leucine-rich proteoglycan decorin is generally considered a pro-angiogenic factor. Here, we investigate whether overexpression of decorin ameliorates diabetic cardiomyopathy and its effects on angiogenesis in vivo and in vitro. Diabetes was induced through intraperitoneal injection with streptozotocin combined with a high-fat diet, and decorin was overexpressed via recombinant adeno-associated virus in Wistar rats. Six months later, cardiac function was determined using an echocardiography and cardiac catheter system. The results showed that cardiac function was decreased in diabetic rats and restored by overexpression of decorin. In addition, overexpression of decorin upregulated the expression of VEGF and attenuated the reduction in the cardiac capillary density. In the in vitro study, high glucose induced apoptosis and inhibited the capabilities of tube formation, migration and proliferation, which were all ameliorated by decorin overexpression. Meanwhile, decorin overexpression increased the expression of VEGF and IGF1R, as well as the phosphorylation level of AKT and AP-1. Nonetheless, all of these effects were abolished by pretreatment with the IGF1R antibody or AKT inhibitor. In conclusion, overexpression of decorin ameliorated diabetic cardiomyopathy and promoted angiogenesis through the IGF1R-AKT-VEGF signaling pathway in vivo and in vitro.

  14. Disruption of IGF-1R signaling increases TRAIL-induced apoptosis: A new potential therapy for the treatment of melanoma

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    Karasic, Thomas B.; Hei, Tom K. [Center for Radiological Research, Department of Radiation Oncology, College of Physicians and Surgeons, Columbia University, New York, NY 10032 (United States); Ivanov, Vladimir N., E-mail: vni3@columbia.edu [Center for Radiological Research, Department of Radiation Oncology, College of Physicians and Surgeons, Columbia University, New York, NY 10032 (United States)

    2010-07-15

    Resistance of cancer cells to apoptosis is dependent on a balance of multiple genetic and epigenetic mechanisms, which up-regulate efficacy of the surviving growth factor-receptor signaling pathways and suppress death-receptor signaling pathways. The Insulin-like Growth Factor-1 Receptor (IGF-1R) signaling pathway is highly active in metastatic melanoma cells by mediating downstream activation of PI3K-AKT and MAPK pathways and controlling general cell survival and proliferation. In the present study, we used human melanoma lines with established genotypes that represented different phases of cancer development: radial-growth-phase WM35, vertical-growth-phase WM793, metastatic LU1205 and WM9 [1]. All these lines have normal NRAS. WM35, WM793, LU1205 and WM9 cells have mutated BRAF (V600E). WM35 and WM9 cells express normal PTEN, while in WM793 cells PTEN expression is down-regulated; finally, in LU1205 cells PTEN is inactivated by mutation. Cyclolignan picropodophyllin (PPP), a specific inhibitor of IGF-1R kinase activity, strongly down-regulated the basal levels of AKT activity in WM9 and in WM793 cells, modestly does so in LU1205, but has no effect on AKT activity in the early stage WM35 cells that are deficient in IGF-1R. In addition, PPP partially down-regulated the basal levels of active ERK1/2 in all lines used, highlighting the role of an alternative, non-BRAF pathway in MAPK activation. The final result of PPP treatment was an induction of apoptosis in WM793, WM9 and LU1205 melanoma cells. On the other hand, dose-dependent inhibition of IGF-1R kinase activity by PPP at a relatively narrow dose range (near 500 nM) has different effects on melanoma cells versus normal cells, inducing apoptosis in cancer cells and G2/M arrest of fibroblasts. To further enhance the pro-apoptotic effects of PPP on melanoma cells, we used a combined treatment of TNF-Related Apoptosis-Inducing Ligand (TRAIL) and PPP. This combination substantially increased death by apoptosis for

  15. The strength of small: Improved targeting of Insulin-like Growth Factor-1 Receptor (IGF-1R) with F(ab')2-R1507 fragments in Ewing sarcomas

    NARCIS (Netherlands)

    Fleuren, Emmy D. G.; Versleijen-Jonkers, Yvonne M. H.; Heskamp, Sandra; Roeffen, Melissa H. S.; Bouwman, Wilbert H.; Molkenboer-Kuenen, Janneke D. M.; van Laarhoven, Hanneke W. M.; Oyen, Wim J. G.; Boerman, Otto C.; van der Graaf, Winette T. A.

    2013-01-01

    To investigate whether F(ab')2-fragments of the monoclonal Insulin-like Growth Factor-1 Receptor (IGF-1R) antibody R1507 (F(ab')2-R1507) can successfully target IGF-1R in Ewing sarcomas (ES). BALB/c nude mice were subcutaneously implanted with IGF-1R-expressing human ES xenografts (EW-5 and EW-8)

  16. CD99 triggering induces methuosis of Ewing sarcoma cells through IGF-1R/RAS/Rac1 signaling.

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    Manara, Maria Cristina; Terracciano, Mario; Mancarella, Caterina; Sciandra, Marika; Guerzoni, Clara; Pasello, Michela; Grilli, Andrea; Zini, Nicoletta; Picci, Piero; Colombo, Mario P; Morrione, Andrea; Scotlandi, Katia

    2016-11-29

    CD99 is a cell surface molecule that has emerged as a novel target for Ewing sarcoma (EWS), an aggressive pediatric bone cancer. This report provides the first evidence of methuosis in EWS, a non-apoptotic form of cell death induced by an antibody directed against the CD99 molecule. Upon mAb triggering, CD99 induces an IGF-1R/RAS/Rac1 complex, which is internalized into RAB5-positive endocytic vacuoles. This complex is then dissociated, with the IGF-1R recycling to the cell membrane while CD99 and RAS/Rac1 are sorted into immature LAMP-1-positive vacuoles, whose excessive accumulation provokes methuosis. This process, which is not detected in CD99-expressing normal mesenchymal cells, is inhibited by disruption of the IGF-1R signaling, whereas enhanced by IGF-1 stimulation. Induction of IGF-1R/RAS/Rac1 was also observed in the EWS xenografts that respond to anti-CD99 mAb, further supporting the role of the IGF/RAS/Rac1 axis in the hyperstimulation of macropinocytosis and selective death of EWS cells. Thus, we describe a vulnerability of EWS cells, including those resistant to standard chemotherapy, to a treatment with anti-CD99 mAb, which requires IGF-1R/RAS signaling but bypasses the need for their direct targeting. Overall, we propose CD99 targeting as new opportunity to treat EWS patients resistant to canonical apoptosis-inducing agents.

  17. Role of RBP2-Induced ER and IGF1R-ErbB Signaling in Tamoxifen Resistance in Breast Cancer.

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    Choi, Hee-Joo; Joo, Hyeong-Seok; Won, Hee-Young; Min, Kyueng-Whan; Kim, Hyung-Yong; Son, Taekwon; Oh, Young-Ha; Lee, Jeong-Yeon; Kong, Gu

    2018-04-01

    Despite the benefit of endocrine therapy, acquired resistance during or after treatment still remains a major challenge in estrogen receptor (ER)-positive breast cancer. We investigated the potential role of histone demethylase retinoblastoma-binding protein 2 (RBP2) in endocrine therapy resistance of breast cancer. Survival of breast cancer patients according to RBP2 expression was analyzed in three different breast cancer cohorts including METABRIC (n = 1980) and KM plotter (n = 1764). RBP2-mediated tamoxifen resistance was confirmed by invitro sulforhodamine B (SRB) colorimetric, colony-forming assays, and invivo xenograft models (n = 8 per group). RNA-seq analysis and receptor tyrosine kinase assay were performed to identify the tamoxifen resistance mechanism by RBP2. All statistical tests were two-sided. RBP2 was associated with poor prognosis to tamoxifen therapy in ER-positive breast cancer (P = .04 in HYU cohort, P = .02 in KM plotter, P = .007 in METABRIC, log-rank test). Furthermore, RBP2 expression was elevated in patients with tamoxifen-resistant breast cancer (P = .04, chi-square test). Knockdown of RBP2 conferred tamoxifen sensitivity, whereas overexpression of RBP2 induced tamoxifen resistance invitro and invivo (MCF7 xenograft: tamoxifen-treated control, mean [SD] tumor volume = 70.8 [27.9] mm3, vs tamoxifen-treated RBP2, mean [SD] tumor volume = 387.9 [85.1] mm3, P < .001). Mechanistically, RBP2 cooperated with ER co-activators and corepressors and regulated several tamoxifen resistance-associated genes, including NRIP1, CCND1, and IGFBP4 and IGFBP5. Furthermore, epigenetic silencing of IGFBP4/5 by RBP2-ER-NRIP1-HDAC1 complex led to insulin-like growth factor-1 receptor (IGF1R) activation. RBP2 also increased IGF1R-ErbB crosstalk and subsequent PI3K-AKT activation via demethylase activity-independent ErbB protein stabilization. Combinational treatment with tamoxifen and PI3K inhibitor could overcome RBP2-mediated tamoxifen

  18. Inhibition of EGFR or IGF-1R signaling enhances radiation response in head and neck cancer models but concurrent inhibition has no added benefit

    International Nuclear Information System (INIS)

    Raju, Uma; Molkentine, David P; Valdecanas, David R; Deorukhkar, Amit; Mason, Kathryn A; Buchholz, Thomas A; Meyn, Raymond E; Ang, Kie-Kian; Skinner, Heath

    2015-01-01

    Interaction between the epidermal growth factor receptor (EGFR) and the insulin-like growth factor receptor (IGF-1R) has been well established in many cancer types. We investigated the effects of cetuximab (EGFR antibody) and IMC-A12 (IGF-1R antibody) on the response of head and neck squamous cell carcinoma (HNSCC) to radiation therapy (RT). The effects of cetuximab and IMC-A12 on cell viability and radiosensitivity were determined by clonogenic cell survival assay. Formation of nuclear γ-H2AX and 53BP1 foci was monitored by immunofluorescence. Alterations in target signaling were analyzed by Western blots. In vivo tumor growth delay assay was performed to determine the efficacy of triple therapy with IMC-A12, cetuximab, and RT. In vitro data showed that cetuximab differentially affected the survival and the radiosensitivity of HNSCC cells. Cetuximab suppressed DNA repair that was evident by the prolonged presence of nuclear γ-H2AX and 53BP1 foci. IMC-A12 did not have any effect on the cell survival. However, it increased the radiosensitivity of one of the cell lines. EGFR inhibition increased IGF-1R expression levels and also the association between EGFR and IGF-1R. Addition of IMC-A12 to cetuximab did not increase the radiosensitivity of these cells. Tumor xenografts exhibited enhanced response to RT in the presence of either cetuximab or IMC-A12. Concurrent treatment regimen failed to further enhance the tumor response to cetuximab and/or RT. Taken together our data suggest that concomitant inhibition of both EGFR and IGF-1R pathways did not yield additional therapeutic benefit in overcoming resistance to RT

  19. R1507, an Anti-Insulin-Like Growth Factor-1 Receptor (IGF-1R) Antibody, and EWS/FLI-1 siRNA in Ewing's Sarcoma: Convergence at the IGF/IGFR/Akt Axis

    Science.gov (United States)

    Rodon, Jordi; Sun, Michael; Kuenkele, Klaus-Peter; Parsons, Henrique A.; Trent, Jonathan C.; Kurzrock, Razelle

    2011-01-01

    A subset of patients with Ewing's sarcoma responds to anti-insulin-like growth factor-1 receptor (IGF-1R) antibodies. Mechanisms of sensitivity and resistance are unknown. We investigated whether an anti-IGF-1R antibody acts via a pathway that could also be suppressed by small interfering (si) RNA against the EWS/FLI-1 fusion protein, the hallmark of Ewing's sarcoma. The growth of two Ewing's sarcoma cell lines (TC-32 and TC-71) was inhibited by the fully human anti-IGF-1R antibody, R1507 (clonogenic and MTT assays). TC-32 and TC-71 cells express high levels of IGF-2, while RD-ES and A4573 Ewing's cell lines, which were less responsive to R1507 in our assays, express low or undetectable IGF-2, respectively. TC-71 cells also expressed high levels of IGF-1R, and R1507 decreased steady-state levels of this receptor by internalization/degradation, an effect which was associated with a decrease in p-IGF-1R, p-IRS-1, and p-Akt. EWS/FLI-1 siRNA also decreased p-Akt, due to its ability to increase IGF-BP3 levels and subsequently decrease IGF-1 and IGF-2 levels, thus inhibiting signaling through p-IGF-1R. This inhibition correlated with growth suppression and apoptosis. The attenuation of Akt activation was confirmed in TC-71 and HEK-293 (human embryonic kidney) cells by transfecting them with IGF-1R siRNA. We conclude that antibodies and siRNA to IGF-1R, as well as siRNA to EWS/FLI-1, act via intersecting IGF/IGF-1R signals that suppress a common point in this pathway, namely the phosphorylation of Akt. PMID:22022506

  20. R1507, an anti-insulin-like growth factor-1 receptor (IGF-1R antibody, and EWS/FLI-1 siRNA in Ewing's sarcoma: convergence at the IGF/IGFR/Akt axis.

    Directory of Open Access Journals (Sweden)

    Helen J Huang

    Full Text Available A subset of patients with Ewing's sarcoma responds to anti-insulin-like growth factor-1 receptor (IGF-1R antibodies. Mechanisms of sensitivity and resistance are unknown. We investigated whether an anti-IGF-1R antibody acts via a pathway that could also be suppressed by small interfering (si RNA against the EWS/FLI-1 fusion protein, the hallmark of Ewing's sarcoma. The growth of two Ewing's sarcoma cell lines (TC-32 and TC-71 was inhibited by the fully human anti-IGF-1R antibody, R1507 (clonogenic and MTT assays. TC-32 and TC-71 cells express high levels of IGF-2, while RD-ES and A4573 Ewing's cell lines, which were less responsive to R1507 in our assays, express low or undetectable IGF-2, respectively. TC-71 cells also expressed high levels of IGF-1R, and R1507 decreased steady-state levels of this receptor by internalization/degradation, an effect which was associated with a decrease in p-IGF-1R, p-IRS-1, and p-Akt. EWS/FLI-1 siRNA also decreased p-Akt, due to its ability to increase IGF-BP3 levels and subsequently decrease IGF-1 and IGF-2 levels, thus inhibiting signaling through p-IGF-1R. This inhibition correlated with growth suppression and apoptosis. The attenuation of Akt activation was confirmed in TC-71 and HEK-293 (human embryonic kidney cells by transfecting them with IGF-1R siRNA. We conclude that antibodies and siRNA to IGF-1R, as well as siRNA to EWS/FLI-1, act via intersecting IGF/IGF-1R signals that suppress a common point in this pathway, namely the phosphorylation of Akt.

  1. Overcoming IGF1R/IR Resistance Through Inhibition of MEK Signaling in Colorectal Cancer Models

    Science.gov (United States)

    Flanigan, Sara A.; Pitts, Todd M.; Newton, Timothy P.; Kulikowski, Gillian N.; Tan, Aik Choon; McManus, Martine C.; Spreafico, Anna; Kachaeva, Maria I.; Selby, Heather M.; Tentler, John J.; Eckhardt, S. Gail; Leong, Stephen

    2013-01-01

    Purpose Results from clinical trials involving resistance to molecularly targeted therapies have revealed the importance of rational single agent and combination treatment strategies. In this study, we tested the efficacy of a type 1 insulin-like growth factor receptor (IGF1R)/insulin receptor (IR) tyrosine kinase inhibitor (TKI), OSI-906, in combination with a MEK 1/2 inhibitor based on evidence that the MAPK pathway was upregulated in colorectal cancer (CRC) cell lines that were resistant to OSI-906. Experimental Design The antiproliferative effects of OSI-906 and the MEK 1/2 inhibitor U0126, were analyzed both as single agents and in combination in 13 CRC cell lines in vitro. Apoptosis, downstream effector proteins, and cell cycle were also assessed. Additionally, the efficacy of OSI-906 combined with the MEK 1/2 inhibitor selumetinib (AZD6244, ARRY-142886), was evaluated in vivo using human CRC xenograft models. Results The combination of OSI-906 and U0126 resulted in synergistic effects in 11 out of 13 CRC cell lines tested. This synergy was variably associated with apoptosis or cell cycle arrest in addition to molecular effects on pro-survival pathways. The synergy was also reflected in the in vivo xenograft studies following treatment with the combination of OSI-906 and selumetinib. Conclusions Results from this study demonstrate synergistic antiproliferative effects in response to the combination of OSI-906 with a MEK 1/2 inhibitor in CRC cell line models both in vitro and in vivo, which supports the rational combination of OSI-906 with a MEK inhibitor in patients with CRC. PMID:24045180

  2. Complement component 1, q subcomponent binding protein (C1QBP) in lipid rafts mediates hepatic metastasis of pancreatic cancer by regulating IGF-1/IGF-1R signaling.

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    Shi, Haojun; Fang, Winston; Liu, Minda; Fu, Deliang

    2017-10-01

    Pancreatic cancer shows a remarkable predilection for hepatic metastasis. Complement component 1, q subcomponent binding protein (C1QBP) can mediate growth factor-induced cancer cell chemotaxis and distant metastasis by activation of receptor tyrosine kinases. Coincidentally, insulin-like growth factor-1 (IGF-1) derived from the liver and cancer cells itself has been recognized as a critical inducer of hepatic metastasis. However, the mechanism underlying IGF-1-dependent hepatic metastasis of pancreatic cancer, in which C1QBP may be involved, remains unknown. In the study, we demonstrated a significant association between C1QBP expression and hepatic metastasis in patients with pancreatic cancer. IGF-1 induced the translocation of C1QBP from cytoplasm to lipid rafts and further drove the formation of CD44 variant 6 (CD44v6)/C1QBP complex in pancreatic cancer cells. C1QBP interacting with CD44v6 in lipid rafts promoted phosphorylation of IGF-1R and thus activated downstream PI3K and MAPK signaling pathways which mediated metastatic potential of pancreatic cancer cells including proliferation, apoptosis, invasion, adhesion and energy metabolism. Furthermore, C1QBP knockdown suppressed hepatic metastasis of pancreatic cancer cells in nude mice. We therefore conclude that C1QBP in lipid rafts serves a key regulator of IGF-1/IGF-1R-induced hepatic metastasis from pancreatic cancer. Our findings about C1QBP in lipid rafts provide a novel strategy to block IGF-1/IGF-1R signaling in pancreatic cancer and a reliable premise for more efficient combined modality therapies. © 2017 UICC.

  3. Resveratrol suppresses IGF-1 induced human colon cancer cell proliferation and elevates apoptosis via suppression of IGF-1R/Wnt and activation of p53 signaling pathways

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    Radhakrishnan Sridhar

    2010-05-01

    Full Text Available Abstract Background Obesity is a global phenomenon and is associated with various types of cancer, including colon cancer. There is a growing interest for safe and effective bioactive compounds that suppress the risk for obesity-promoted colon cancer. Resveratrol (trans-3, 4', 5,-trihydroxystilbene, a stilbenoid found in the skin of red grapes and peanuts suppresses many types of cancers by regulating cell proliferation and apoptosis through a variety of mechanisms, however, resveratrol effects on obesity-promoted colon cancer are not clearly established. Methods We investigated the anti-proliferative effects of resveratrol on HT-29 and SW480 human colon cancer cells in the presence and absence of insulin like growth factor-1 (IGF-1; elevated during obesity and elucidated the mechanisms of action using IGF-1R siRNA in HT-29 cells which represents advanced colon carcinogenesis. Results Resveratrol (100-150 μM exhibited anti-proliferative properties in HT-29 cells even after IGF-1 exposure by arresting G0/G1-S phase cell cycle progression through p27 stimulation and cyclin D1 suppression. Treatment with resveratrol suppressed IGF-1R protein levels and concurrently attenuated the downstream Akt/Wnt signaling pathways that play a critical role in cell proliferation. Targeted suppression of IGF-1R using IGF-1R siRNA also affected these signaling pathways in a similar manner. Resveratrol treatment induced apoptosis by activating tumor suppressor p53 protein, whereas IGF-1R siRNA treatment did not affect apoptosis. Our data suggests that resveratrol not only suppresses cell proliferation by inhibiting IGF-1R and its downstream signaling pathways similar to that of IGF-1R siRNA but also enhances apoptosis via activation of the p53 pathway. Conclusions For the first time, we report that resveratrol suppresses colon cancer cell proliferation and elevates apoptosis even in the presence of IGF-1 via suppression of IGF-1R/Akt/Wnt signaling pathways and

  4. Resveratrol suppresses IGF-1 induced human colon cancer cell proliferation and elevates apoptosis via suppression of IGF-1R/Wnt and activation of p53 signaling pathways

    International Nuclear Information System (INIS)

    Vanamala, Jairam; Reddivari, Lavanya; Radhakrishnan, Sridhar; Tarver, Chris

    2010-01-01

    Obesity is a global phenomenon and is associated with various types of cancer, including colon cancer. There is a growing interest for safe and effective bioactive compounds that suppress the risk for obesity-promoted colon cancer. Resveratrol (trans-3, 4', 5,-trihydroxystilbene), a stilbenoid found in the skin of red grapes and peanuts suppresses many types of cancers by regulating cell proliferation and apoptosis through a variety of mechanisms, however, resveratrol effects on obesity-promoted colon cancer are not clearly established. We investigated the anti-proliferative effects of resveratrol on HT-29 and SW480 human colon cancer cells in the presence and absence of insulin like growth factor-1 (IGF-1; elevated during obesity) and elucidated the mechanisms of action using IGF-1R siRNA in HT-29 cells which represents advanced colon carcinogenesis. Resveratrol (100-150 μM) exhibited anti-proliferative properties in HT-29 cells even after IGF-1 exposure by arresting G 0 /G 1 -S phase cell cycle progression through p27 stimulation and cyclin D1 suppression. Treatment with resveratrol suppressed IGF-1R protein levels and concurrently attenuated the downstream Akt/Wnt signaling pathways that play a critical role in cell proliferation. Targeted suppression of IGF-1R using IGF-1R siRNA also affected these signaling pathways in a similar manner. Resveratrol treatment induced apoptosis by activating tumor suppressor p53 protein, whereas IGF-1R siRNA treatment did not affect apoptosis. Our data suggests that resveratrol not only suppresses cell proliferation by inhibiting IGF-1R and its downstream signaling pathways similar to that of IGF-1R siRNA but also enhances apoptosis via activation of the p53 pathway. For the first time, we report that resveratrol suppresses colon cancer cell proliferation and elevates apoptosis even in the presence of IGF-1 via suppression of IGF-1R/Akt/Wnt signaling pathways and activation of p53, suggesting its potential role as a

  5. CD99 triggering induces methuosis of Ewing sarcoma cells through IGF-1R/RAS/Rac1 signaling

    OpenAIRE

    Manara, Maria Cristina; Terracciano, Mario; Mancarella, Caterina; Sciandra, Marika; Guerzoni, Clara; Pasello, Michela; Grilli, Andrea; Zini, Nicoletta; Picci, Piero; Colombo, Mario P.; Morrione, Andrea; Scotlandi, Katia

    2016-01-01

    CD99 is a cell surface molecule that has emerged as a novel target for Ewing sarcoma (EWS), an aggressive pediatric bone cancer. This report provides the first evidence of methuosis in EWS, a non-apoptotic form of cell death induced by an antibody directed against the CD99 molecule. Upon mAb triggering, CD99 induces an IGF-1R/RAS/Rac1 complex, which is internalized into RAB5-positive endocytic vacuoles. This complex is then dissociated, with the IGF-1R recycling to the cell membrane while CD9...

  6. Insulin growth factor-1 receptor (IGF-1R) expression as a prognostic indicator of local recurrence in conservatively treated breast cancer: a case-control study

    International Nuclear Information System (INIS)

    Turner, B.C.; Haffty, B.G.; Carter, D.; Gumbs, A.A.; Naryanan, L.; Baserga, R.; Glazer, P.M.

    1996-01-01

    Purpose: The IGF-1R is a glycoprotein receptor that consists of a heterodimer of two alpha and two beta subunits which are processed from a single precursor transmembrane polypeptide and has been found to be overexpressed in a variety of tumors. IGF-1R has been shown to play a critical role in malignant transformation and to influence apoptosis. We have recently shown in gene transfer studies that overexpression of the IGF-1R confers relative radioresistance on mouse fibroblasts in culture. To test the significance of this finding in a clinical setting, we have sought to determine the prognostic significance of overexpression of IGF-1R with respect to ipsilateral breast tumor recurrence (IBTR) in the conservatively treated breast cancer patient. Materials and Methods: Over 1,000 breast cancer patients treated with conservative surgery followed by radiation therapy to the intact breast served as the patient population for this study. Twenty-five patients with a diagnosis of invasive ductal carcinoma who had an IBTR as the first site of failure comprised the index case population base of this study. Following the identification of 25 patients with IBTR, the breast database was searched for 25 matching control patients who did not have an IBTR. The control patients were matched to the index case with respect to age (within 5 years), menopausal status, approximate date of radiation therapy, primary histology, axillary dissection, nodal status, primary tumor size, estrogen/progesterone receptor (ER/PR) status, and adjuvant chemotherapy/hormonal therapy. Both index cases and the matched control group received radiation therapy to a total dose of 64 Gy to the tumor bed. Following identification of index and control cases, the individual paraffin-embedded blocks (PEB) were evaluated for invasive ductal carcinoma with H and E staining by the pathologist. All PEB were then processed for immunohistochemical staining with a polyclonal antibody to the beta-chain of IGF-1R

  7. Integrated molecular targeting of IGF1R and HER2 surface receptors and destruction of breast cancer cells using single wall carbon nanotubes

    International Nuclear Information System (INIS)

    Shao Ning; Lu Shaoxin; Wickstrom, Eric; Panchapakesan, Balaji

    2007-01-01

    Molecular targeting and photodynamic therapy have shown great potential for selective cancer therapy. We hypothesized that monoclonal antibodies that are specific to the IGF1 receptor and HER2 cell surface antigens could be bound to single wall carbon nanotubes (SWCNT) in order to concentrate SWCNT on breast cancer cells for specific near-infrared phototherapy. SWCNT functionalized with HER2 and IGF1R specific antibodies showed selective attachment to breast cancer cells compared to SWCNT functionalized with non-specific antibodies. After the complexes were attached to specific cancer cells, SWCNT were excited by ∼808 nm infrared photons at ∼800 mW cm -2 for 3 min. Viability after phototherapy was determined by Trypan blue exclusion. Cells incubated with SWCNT/non-specific antibody hybrids were still alive after photo-thermal treatment due to the lack of SWNT binding to the cell membrane. All cancerous cells treated with IGF1R and HER2 specific antibody/SWCNT hybrids and receiving infrared photons showed cell death after the laser excitation. Quantitative analysis demonstrated that all the cells treated with SWCNT/IGF1R and HER2 specific antibody complex were completely destroyed, while more than 80% of the cells with SWCNT/non-specific antibody hybrids remained alive. Following multi-component targeting of IGF1R and HER2 surface receptors, integrated photo-thermal therapy in breast cancer cells led to the complete destruction of cancer cells. Functionalizing SWCNT with antibodies in combination with their intrinsic optical properties can therefore lead to a new class of molecular delivery and cancer therapeutic systems

  8. Gastric cancer: the role of insulin-like growth factor 2 (IGF 2) and its receptors (IGF 1R and M6-P/IGF 2R).

    Science.gov (United States)

    Pavelić, Kresimir; Kolak, Toni; Kapitanović, Sanja; Radosević, Senka; Spaventi, Sime; Kruslin, Bozo; Pavelić, Jasminka

    2003-11-01

    Insulin-like growth factor 2 (IGF 2) appears to be involved in the progression of many tumours. It binds to at least two different types of receptor: IGF type 1 (IGF 1R) and mannose 6-phosphate/IGF type 2 (M6-P/IGF 2R). Ligand binding to IGF 1R provokes mitogenic and anti-apoptotic effects. M6-P/IGF 2R has a tumour suppressor function--it mediates IGF 2 degradation. Mutation of M6-P/IGF 2R causes both diminished growth suppression and augmented growth stimulation. The aim of this study was to investigate the role of IGF 2 and its receptors (IGF 1R and IGF 2R) in human gastric cancer. The expression of IGF 2 and its receptors was measured in order to analyse the possible correlation between the activity of these genes and cell proliferation in two different gastric tumour types: diffuse and intestinal. The effect of IGF 1 receptor blockage on cell proliferation and anchorage-independent cell growth was also examined. Increased expression of IGF 2 and IGF 1R genes (at the mRNA and protein level) was found in gastric cancer when compared with non-tumour tissue. Furthermore, there was a significant difference between IGF 2 expression in the more aggressive diffuse type and that in the intestinal type of gastric cancer. Moreover, the IGF 2 peptide level in the culture media obtained from the diffuse type of cancer cells was significantly higher when compared with the intestinal type. The level of IGF 2 peptide in the conditioned media strongly correlated with [3H]thymidine incorporation and cell proliferation. On the contrary, IGF 2R mRNA expression was much higher in the intestinal type of cancer than in the diffuse type. In addition, IGF 2R protein expression was substantially lower with progression of the diffuse cancer type to a higher stage. The alphaIR3 monoclonal antibody strongly inhibited [3H]thymidine incorporation and decreased the number of colonies in soft agar of cells overexpressing IGF 2. These findings suggest that members of the IGF family are involved

  9. Stress-altered synaptic plasticity and DAMP signaling in the hippocampus-PFC axis; elucidating the significance of IGF-1/IGF-1R/CaMKIIα expression in neural changes associated with a prolonged exposure therapy.

    Science.gov (United States)

    Ogundele, Olalekan M; Ebenezer, Philip J; Lee, Charles C; Francis, Joseph

    2017-06-14

    Traumatic stress patients showed significant improvement in behavior after a prolonged exposure to an unrelated stimulus. This treatment method attempts to promote extinction of the fear memory associated with the initial traumatic experience. However, the subsequent prolonged exposure to such stimulus creates an additional layer of neural stress. Although the mechanism remains unclear, prolonged exposure therapy (PET) likely involves changes in synaptic plasticity, neurotransmitter function and inflammation; especially in parts of the brain concerned with the formation and retrieval of fear memory (Hippocampus and Prefrontal Cortex: PFC). Since certain synaptic proteins are also involved in danger-associated molecular pattern signaling (DAMP), we identified the significance of IGF-1/IGF-1R/CaMKIIα expression as a potential link between the concurrent progression of synaptic and inflammatory changes in stress. Thus, a comparison between IGF-1/IGF-1R/CaMKIIα, synaptic and DAMP proteins in stress and PET may highlight the significance of PET on synaptic morphology and neuronal inflammatory response. In behaviorally characterized Sprague-Dawley rats, there was a significant decline in neural IGF-1 (pIGF-1R expression. These animals showed a significant loss of presynaptic markers (synaptophysin; pIGF-1 (pIGF-1R was recorded in the Stress-PET group (pIGF-1/IGF-1R, an increase in activated hippocampal and cortical microglia was seen in stress (pIGF1/IGF-1R/CaMKIIα. Firstly, we showed a direct relationship between IGF-1/IGF-1R expression, presynaptic function (synaptophysin) and neurotransmitter activity in stress and PET. Secondly, we identified the possible role of CaMKIIα in post-synaptic function and regulation of small ion conductance channels. Lastly, we highlighted some of the possible links between IGF1/IGF-1R/CaMKIIα, the expression of DAMP proteins, Microglia activation, and its implication on synaptic plasticity during stress and PET. Copyright © 2017

  10. IMPACT STUDY: MK-0646 (DALOTUZUMAB, INSULIN GROWTH FACTOR 1 RECEPTOR (IGF-1R ANTIBODY COMBINED WITH PEMETREXED AND CISPLATIN IN STAGE IV METASTATIC NON-SQUAMOUS LUNG CANCER

    Directory of Open Access Journals (Sweden)

    Chao H Huang

    2016-01-01

    Full Text Available Background: Insulin-like growth factor 1 receptor (IGF-1R regulates cell growth, proliferation and apoptosis. Adenocarcinoma and never-smokers have a higher expression of IGF-1R, which is associated with worse overall survival. Dalotuzumab-MK0646 (D is a humanized monoclonal antibody that targets IGF-1R. Pemetrexed (P has higher activity in non-squamous lung cancer (NSQL. We initiated a randomized phase II trial to test the combination of P and Cisplatin (C +/- D in NSQL.Methods: Eligibility criteria: untreated NSQL stage IIIB or IV, ECOG 0 or 1, measurable disease, adequate renal, hepatic and hematologic function, and no other intercurrent illness. P at 500mg/m2 and C at 75mg/m2 IV were given every 3 weeks. D was given at 10mg/kg IV weekly on days 1, 8 and 15 of every 3-week cycle in the experimental group. The patients had a radiographic assessment after every 2 cycles and were treated for a maximum of 6 cycles if there was a response or stable disease. The primary objective of the study was to compare the clinical response rates of PC vs PC+D. Results: From 1/2009 to 2/2011, the study accrued 26 subjects: 16 male and 10 female, with a median age of 59; 14 were treated with PC and 12 were treated with PC+D. We observed 2 partial responses (PR, 7 stable disease (SD, 3 progressive disease (PD, and 2 were not evaluable (NE in the PC arm. In comparison, for the PC+D arm there were: 3 PR, 4 SD, 4 PD and 1 NE. The hematologic toxicity was similar in both groups. There higher incidence of hyperglycemia the experimental group; 4 cases with grade 3 and 1 case with grade 4. Conclusion: PC+D had a similar response rate compared to PC, with a higher rate of hyperglycemia. Identification of responders using predictive markers would be key to continuing the study of D in NSQL.

  11. Targeting the IGF-1R: The Tale of The Tortoise and The Hare

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    Caitrin eCrudden

    2015-04-01

    Full Text Available The insulin-like growth factor type 1 receptor (IGF-1R plays a key role in the development and maintenance of cancer. Since the first links between growth factor receptors and oncogenes were noted over three decades ago, targeting the IGF-1R has been of great interest. This review follows the progress from inception through intense pharmaceutical development, disappointing clinical trials and recent updates to the signaling paradigm. In light of major developments in signaling understanding and activation complexities, we examine reasons for failure of first line targeting approaches. Recent findings include the fact that the IGF-1R can signal in the absence of the ligand, in the absence of kinase activity and utilizes components of the GPCR system. With recognition of the unappreciated complexities that this first wave of targeting approaches encountered, we advocate recognition of IGF-1R as a valid target for cancer treatment and look to future directions, where both research and pharmaceutical strengths can lend themselves to finally unearthing anti-IGF-1R potential.

  12. IDH1R132H Promotes Malignant Transformation of Benign Prostatic Epithelium by Dysregulating MicroRNAs: Involvement of IGF1R-AKT/STAT3 Signaling Pathway

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    Lili Zhang

    2018-02-01

    Full Text Available Risk stratification using molecular features could potentially help distinguish indolent from aggressive prostate cancer (PCa. Mutations in isocitrate dehydrogenase (IDH acquire an abnormal enzymatic activity, resulting in the production of 2-hydroxyglutarate and alterations in cellular metabolism, histone modification, and DNA methylation. Mutant IDH1 has been identified in various human malignancies, and IDH1R132H constituted the vast majority of mutational events of IDH1. Most recent studies suggested that IDH1 mutations define a methylator subtype in PCa. However, the function of IDH1R132H in PCa development and progression is largely unknown. In this study, we showed that the prevalence of IDH1R132H in Chinese PCa patients is 0.6% (2/336. Of note, IDH1R132H-mutant PCa patients lacked other canonical genomic lesions (e.g., ERG rearrangement, PTEN deletion that are common in most other PCa patients. The in vitro experiment suggested that IDH1R132H can promote proliferation of benign prostate epithelial cell RWPE-1 when under the situation of low cytokine. It could also promote migration capacity of RWPE-1 cells. Mechanistically, IDH1R132H was an important regulator of insulin-like growth factor 1receptor (IGF1R by downregulating a set of microRNAs (miR-141-3p, miR-7-5p, miR-223-3p. These microRNAs were repressed by the alteration of epigenetic modification to decrease the enrichment of active marker H3K4me3 or to increase repressive marker H3K27me3 at their promoters. Collectively, we proposed a novel model for an IDH1R132H-microRNAs-IGF1R regulatory axis, which might provide insight into the function of IDH1R132H in PCa development.

  13. Role of IGF-1R in ameliorating apoptosis of GNE deficient cells.

    Science.gov (United States)

    Singh, Reema; Chaudhary, Priyanka; Arya, Ranjana

    2018-05-09

    Sialic acids (SAs) are nine carbon acidic amino sugars, found at the outermost termini of glycoconjugates performing various physiological and pathological functions. SA synthesis is regulated by UDP-GlcNAc 2-epimerase/ManNAc kinase (GNE) that catalyzes rate limiting steps. Mutations in GNE result in rare genetic disorders, GNE myopathy and Sialuria. Recent studies indicate an alternate role of GNE in cell apoptosis and adhesion, besides SA biosynthesis. In the present study, using a HEK cell-based model for GNE myopathy, the role of Insulin-like Growth Factor Receptor (IGF-1R) as cell survival receptor protein was studied to counter the apoptotic effect of non-functional GNE. In the absence of functional GNE, IGF-1R was hyposialylated and transduced a downstream signal upon IGF-1 (IGF-1R ligand) treatment. IGF-1 induced activation of IGF-1R led to AKT (Protein Kinase B) phosphorylation that may phosphorylate BAD (BCL2 Associated Death Promoter) and its dissociation from BCL2 to prevent apoptosis. However, reduced ERK (Extracellular signal-regulated kinases) phosphorylation in GNE deficient cells after IGF-1 treatment suggests downregulation of the ERK pathway. A balance between the ERK and AKT pathways may determine the cell fate towards survival or apoptosis. Our study suggests that IGF-1R activation may rescue apoptotic cell death of GNE deficient cell lines and has potential as therapeutic target.

  14. Sorafenib inhibits tumor growth and vascularization of rhabdomyosarcoma cells by blocking IGF-1R-mediated signaling

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    Wessen Maruwge

    2008-11-01

    Full Text Available Wessen Maruwge1, Pádraig D’Arcy1, Annika Folin1,2, Slavica Brnjic1, Johan Wejde1, Anthony Davis1, Fredrik Erlandsson3, Jonas Bergh1,2, Bertha Brodin11Department of Oncology and Pathology, Karolinska Institutet, Stockholm, Sweden; 2Radiumhemmet, Karolinska University Hospital, Stockholm, Sweden; 3Bayer Pharmaceutical Corporation, SwedenAbstract: The growth of many soft tissue sarcomas is dependent on aberrant growth factor signaling, which promotes their proliferation and motility. With this in mind, we evaluated the effect of sorafenib, a receptor tyrosine kinase inhibitor, on cell growth and apoptosis in sarcoma cell lines of various histological subtypes. We found that sorafenib effectively inhibited cell proliferation in rhabdomyosarcoma, synovial sarcoma and Ewing’s sarcoma with IC50 values <5 µM. Sorafenib effectively induced growth arrest in rhabdomyosarcoma cells, which was concurrent with inhibition of Akt and Erk signaling. Studies of ligand-induced phosphorylation of Erk and Akt in rhabdomyosarcoma cells showed that insulin-like growth factor-1 is a potent activator, which can be blocked by treatment with sorafenib. In vivo sorafenib treatment of rhabdomyosarcoma xenografts had a significant inhibitory effect on tumor growth, which was associated with inhibited vascularization and enhanced necrosis in the adjacent tumor stroma. Our results demonstrate that in vitro and in vivo growth of rhabdomyosarcoma can be suppressed by treatment with sorafenib, and suggests the possibilities of using sorafenib as a potential adjuvant therapy for the treatment of rhabdomyosarcoma.Keywords: soft tissue sarcoma, kinase inhibitors, targeted therapy, vascularization

  15. Role of IGF1R in breast cancer subtypes, stemness, and lineage differentiation

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    Susan M Farabaugh

    2015-04-01

    Full Text Available Insulin-like growth factor (IGF signaling is fundamental for growth and survival. A large body of evidence (laboratory, epidemiological, and clinical implicates the exploitation of this pathway in cancer. Up to 50% of breast tumors express the activated form of the IGF1 receptor (IGF1R. Breast cancers are categorized into subtypes based upon hormone and ERRB2 receptor expression and/or gene expression profiling. Even though IGF1R influences tumorigenic phenotypes and drug resistance across all breast cancer subtypes, it has specific expression and function in each. In some subtypes, IGF1R levels correlate with a favorable prognosis, while in others it is associated with recurrence and poor prognosis, suggesting different actions based upon cellular and molecular contexts. In this review, we examine IGF1R expression and function as it relates to breast cancer subtype and therapy-acquired resistance. Additionally, we discuss the role of IGF1R in stem cell maintenance and lineage differentiation and how these cell fate influences may alter the differentiation potential and cellular composition of breast tumors.

  16. MiR-223 suppresses cell proliferation by targeting IGF-1R.

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    Cheng You Jia

    Full Text Available To study the roles of microRNA-223 (miR-223 in regulation of cell growth, we established a miR-223 over-expression model in HeLa cells infected with miR-223 by Lentivirus pLL3.7 system. We observed in this model that miR-223 significantly suppressed the proliferation, growth rate, colony formation of HeLa cells in vitro, and in vivo tumorigenicity or tumor formation in nude mice. To investigate the mechanisms involved, we scanned and examined the potential and putative target molecules of miR-223 by informatics, quantitative PCR and Western blot, and found that insulin-like growth factor-1 receptor (IGF-1R was the functional target of miR-223 inhibition of cell proliferation. Targeting IGF-1R by miR-223 was not only seen in HeLa cells, but also in leukemia and hepatoma cells. The downstream pathway, Akt/mTOR/p70S6K, to which the signal was mediated by IGF-1R, was inhibited as well. The relative luciferase activity of the reporter containing wild-type 3'UTR(3'untranslated region of IGF-1R was significantly suppressed, but the mutant not. Silence of IGF-1R expression by vector-based short hairpin RNA resulted in the similar inhibition with miR-223. Contrarily, rescued IGF-1R expression in the cells that over-expressed miR-223, reversed the inhibition caused by miR-223 via introducing IGF-1R cDNA that didn't contain the 3'UTR. Meanwhile, we also noted that miR-223 targeted Rasa1, but the downstream molecules mediated by Rasa1 was neither targeted nor regulated. Therefore we believed that IGF-1R was the functional target for miR-223 suppression of cell proliferation and its downstream PI3K/Akt/mTOR/p70S6K pathway suppressed by miR-223 was by targeting IGF-1R.

  17. ERK phosphorylation is predictive of resistance to IGF-1R inhibition in small cell lung cancer.

    Science.gov (United States)

    Zinn, Rebekah L; Gardner, Eric E; Marchionni, Luigi; Murphy, Sara C; Dobromilskaya, Irina; Hann, Christine L; Rudin, Charles M

    2013-06-01

    New therapies are critically needed to improve the outcome for patients with small cell lung cancer (SCLC). Insulin-like growth factor 1 receptor (IGF-1R) inhibition is a potential treatment strategy for SCLC: the IGF-1R pathway is commonly upregulated in SCLC and has been associated with inhibition of apoptosis and stimulation of proliferation through downstream signaling pathways, including phosphatidylinositol-3-kinase-Akt and mitogen-activated protein kinase. To evaluate potential determinants of response to IGF-1R inhibition, we assessed the relative sensitivity of 19 SCLC cell lines to OSI-906, a small molecule inhibitor of IGF-1R, and the closely related insulin receptor. Approximately one third of these cell lines were sensitive to OSI-906, with an IC50 OSI-906. Interestingly, OSI-906 sensitive lines expressed significantly lower levels of baseline phospho-ERK relative to resistant lines (P = 0.006). OSI-906 treatment resulted in dose-dependent inhibition of phospho-IGF-1R and phospho-Akt in both sensitive and resistant cell lines, but induced apoptosis and cell-cycle arrest only in sensitive lines. We tested the in vivo efficacy of OSI-906 using an NCI-H187 xenograft model and two SCLC patient xenografts in mice. OSI-906 treatment resulted in 50% tumor growth inhibition in NCI-H187 and 30% inhibition in the primary patient xenograft models compared with mock-treated animals. Taken together our data support IGF-1R inhibition as a viable treatment strategy for a defined subset of SCLC and suggest that low pretreatment levels of phospho-ERK may be indicative of sensitivity to this therapeutic approach. ©2013 AACR

  18. Role of Ubiquitination in IGF-1 Receptor Signaling and Degradation

    OpenAIRE

    Sehat, Bita; Andersson, Sandra; Vasilcanu, Radu; Girnita, Leonard; Larsson, Olle

    2007-01-01

    BACKGROUND: The insulin-like growth factor 1 receptor (IGF-1R) plays numerous crucial roles in cancer biology. The majority of knowledge on IGF-1R signaling is concerned with its role in the activation of the canonical phosphatidyl inositol-3 kinase (PI3K)/Akt and MAPK/ERK pathways. However, the role of IGF-1R ubiquitination in modulating IGF-1R function is an area of current research. In light of this we sought to determine the relationship between IGF-1R phosphorylation, ubiquitination, and...

  19. Involvement of Igf1r in Bronchiolar Epithelial Regeneration: Role during Repair Kinetics after Selective Club Cell Ablation.

    Directory of Open Access Journals (Sweden)

    Icíar P López

    Full Text Available Regeneration of lung epithelium is vital for maintaining airway function and integrity. An imbalance between epithelial damage and repair is at the basis of numerous chronic lung diseases such as asthma, COPD, pulmonary fibrosis and lung cancer. IGF (Insulin-like Growth Factors signaling has been associated with most of these respiratory pathologies, although their mechanisms of action in this tissue remain poorly understood. Expression profiles analyses of IGF system genes performed in mouse lung support their functional implication in pulmonary ontogeny. Immuno-localization revealed high expression levels of Igf1r (Insulin-like Growth Factor 1 Receptor in lung epithelial cells, alveolar macrophages and smooth muscle. To further understand the role of Igf1r in pulmonary homeostasis, two distinct lung epithelial-specific Igf1r mutant mice were generated and studied. The lack of Igf1r disturbed airway epithelial differentiation in adult mice, and revealed enhanced proliferation and altered morphology in distal airway club cells. During recovery after naphthalene-induced club cell injury, the kinetics of terminal bronchiolar epithelium regeneration was hindered in Igf1r mutants, revealing increased proliferation and delayed differentiation of club and ciliated cells. Amid airway restoration, lungs of Igf1r deficient mice showed increased levels of Igf1, Insr, Igfbp3 and epithelial precursor markers, reduced amounts of Scgb1a1 protein, and alterations in IGF signaling mediators. These results support the role of Igf1r in controlling the kinetics of cell proliferation and differentiation during pulmonary airway epithelial regeneration after injury.

  20. Nuclear translocation of IGF1R by intracellular amphiregulin contributes to the resistance of lung tumour cells to EGFR-TKI.

    Science.gov (United States)

    Guerard, Marie; Robin, Thomas; Perron, Pascal; Hatat, Anne-Sophie; David-Boudet, Laurence; Vanwonterghem, Laetitia; Busser, Benoit; Coll, Jean-Luc; Lantuejoul, Sylvie; Eymin, Beatrice; Hurbin, Amandine; Gazzeri, Sylvie

    2018-04-28

    Many Receptor Tyrosine Kinases translocate from the cell surface to the nucleus in normal and pathological conditions, including cancer. Here we report the nuclear expression of insulin-like growth factor-1 receptor (IGF1R) in primary human lung tumours. Using lung cancer cell lines and lung tumour xenografts, we demonstrate that the epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) gefitinib induces the nuclear accumulation of IGF1R in mucinous lung adenocarcinoma by a mechanism involving the intracellular re-localization of the growth factor amphiregulin. Amphiregulin allows the binding of IGF1R to importin-β1 and promotes its nuclear transport. The nuclear accumulation of IGF1R by amphiregulin induces cell cycle arrest through p21 WAF1/CIP1 upregulation, and prevents the induction of apoptosis in response to gefitinib. These results identify amphiregulin as the first nuclear localization signal-containing protein that interacts with IGF1R and allows its nuclear translocation. Furthermore they indicate that nuclear expression of IGF1R contributes to EGFR-TKI resistance in lung cancer. Copyright © 2018 Elsevier B.V. All rights reserved.

  1. A randomized, phase II study of the anti-insulin-like growth factor receptor type 1 (IGF-1R) monoclonal antibody robatumumab (SCH 717454) in patients with advanced colorectal cancer

    International Nuclear Information System (INIS)

    Lin, Edward H; Lenz, Heinz-Josef; Saleh, Mansoor N; Mackenzie, Mary J; Knost, James A; Pathiraja, Kumudu; Langdon, Ronald B; Yao, Siu-Long; Lu, Brian D

    2014-01-01

    Overexpression of insulin-like growth factor receptor type 1 (IGF-1R) may promote tumor development and progression in some cancer patients. Our objective was to assess tumor uptake of fluorodeoxyglucose by positron-emission tomography in patients with chemotherapy-refractory colorectal cancer treated with an anti-insulin-like growth factor receptor type 1 (anti-IGF-1R) monoclonal antibody, robatumumab. This was a randomized, open-label study with two periods (P1 and P2). Patients were randomized 3:1 into treatment arms R/R and C/R that received, respectively, one cycle of 0.3 mg/kg robatumumab or one or more cycles of second-line chemotherapy in P1, followed in either case by 10 mg/kg robatumumab biweekly in P2. The primary measure of fluorodeoxyglucose uptake was maximum standardized uptake value (SUV max ). The primary endpoint was the proportion of patients in the R/R arm having a mean percent decrease from baseline in SUV max (DiSUV) greater than 20% 12–14 days postdose in P2. Secondary endpoints included Response Evaluation Criteria in Solid Tumors (RECIST)-defined tumor response and pharmacodynamic measures of target engagement. Among 41 patients who were evaluable for the primary endpoint, seven (17%, 95% CI 7%–32%) had DiSUV greater than 20%. Fifty robatumumab-treated patients were evaluable for RECIST-defined tumor response and six (12%) had stable disease lasting greater than or equal to 7 weeks in P2. Pharmacodynamic endpoints indicated target engagement after dosing with 10 mg/kg robatumumab, but not 0.3 mg/kg. The most frequently reported adverse events were fatigue/asthenia, nausea, anorexia, and gastrointestinal disturbances. In this study, few patients with chemotherapy-refractory colorectal cancer appeared to benefit from treatment with the IGF-1R antagonist robatumumab

  2. miR-342-3p suppresses hepatocellular carcinoma proliferation through inhibition of IGF-1R-mediated Warburg effect

    Directory of Open Access Journals (Sweden)

    Liu W

    2018-03-01

    Full Text Available Wenpeng Liu,1,* Lei Kang,2,* Juqiang Han,3 Yadong Wang,1 Chuan Shen,1 Zhifeng Yan,4 Yanhong Tai,5 Caiyan Zhao1 1Department of Infectious Diseases, Third Affiliated Hospital of Hebei Medical University, Shijiazhuang, China; 2Department of Nuclear Medicine, Peking University First Hospital, Beijing, China; 3Institute of Liver Disease, Beijing Military General Hospital, Beijing, China; 4Department of Gynecology and Obstetrics, PLA General Hospital, Beijing, China; 5Department of Pathology, Hospital of PLA, Beijing, China *These authors contributed equally to this work Background: Insulin-like growth factor-1 receptor (IGF-1R is a well-studied oncogenic factor that promotes cell proliferation and energy metabolism and is overexpressed in numerous cancers including hepatocellular carcinoma (HCC. Aerobic glycolysis is a hallmark of cancer, and drugs targeting its regulators, including IGF-1R, are being developed. However, the mechanisms of IGF-1R inhibition and the physiological significance of the IGF-1R inhibitors in cancer cells are unclear. Materials and methods: Cell proliferation was evaluated by cell counting Kit-8 and colony formation assay. Western blot and real-time PCR were accordingly used to detect the relevant proteins, miRNA and gene expression. Luciferase reporter assays were used to illustrate the interaction between miR-342-3p and IGF-1R. The effect of miR-342-3p on glycolysis was determined by glucose uptake, ATP concentration, lactate generation, extracellular acidification rate and oxygen consumption rate assays. In vivo, subcutaneous tumor formation assay and PET were performed in nude mice. Results: In this study, we demonstrate that by directly targeting the 3’-UTR (3’-untranslated regions of IGF-1R, microRNA-342-3p (miR-342-3p suppresses IGF-1R-mediated PI3K/AKT/GLUT1 signaling pathway both in vitro and in vivo. Through suppression of IGF-1R, miR-342-3p dampens glycolysis by decreasing glucose uptake, lactate generation

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

    Science.gov (United States)

    2013-02-01

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

  4. No preclinical rationale for IGF1R directed therapy in chondrosarcoma of bone

    International Nuclear Information System (INIS)

    Peterse, Elisabeth F. P.; Cleven, Arjen H. G.; De Jong, Yvonne; Briaire-de Bruijn, Inge; Fletcher, Jonathan A.; Danen, Erik H. J.; Cleton-Jansen, Anne-Marie; Bovée, Judith V. M. G.

    2016-01-01

    Chondrosarcoma is a malignant cartilage forming bone tumour for which no effective systemic treatment is available. Previous studies illustrate the need for a better understanding of the role of the IGF pathway in chondrosarcoma to determine if it can be a target for therapy, which was therefore explored in this study. Expression of mediators of IGF1R signalling and phosphorylation status of IRS1 was determined in chondrosarcoma cell lines by qRT-PCR and western blot. The effect of activation and inhibition of IGF1R signalling on downstream targets was assessed by western blot. Ten chondrosarcoma cell lines were treated with OSI-906 (IGF1R and IR dual inhibitor) after which cell proliferation and migration were determined by a viability assay and the xCELLigence system, respectively. In addition, four chondrosarcoma cell lines were treated with a combination of doxorubicin and OSI-906. By immunohistochemistry, IGF1R expression levels were determined in tissue microarrays of 187 cartilage tumours and ten paraffin embedded cell lines. Mediators of IGF1R signalling are heterogeneously expressed and phosphorylated IRS1 was detected in 67 % of the tested chondrosarcoma cell lines, suggesting that IGF1R signalling is active in a subset of chondrosarcoma cell lines. In the cell lines with phosphorylated IRS1, inhibition of IGF1R signalling decreased phosphorylated Akt levels and increased IGF1R expression, but it did not influence MAPK or S6 activity. In line with these findings, treatment with IGF1R/IR inhibitors did not impact proliferation or migration in any of the chondrosarcoma cell lines, even upon stimulation with IGF1. Although synergistic effects of IGF1R/IR inhibition with doxorubicin are described for other cancers, our results demonstrate that this was not the case for chondrosarcoma. In addition, we found minimal IGF1R expression in primary tumours in contrast to the high expression detected in chondrosarcoma cell lines, even if both were derived from the

  5. No preclinical rationale for IGF1R directed therapy in chondrosarcoma of bone.

    Science.gov (United States)

    Peterse, Elisabeth F P; Cleven, Arjen H G; De Jong, Yvonne; Briaire-de Bruijn, Inge; Fletcher, Jonathan A; Danen, Erik H J; Cleton-Jansen, Anne-Marie; Bovée, Judith V M G

    2016-07-14

    Chondrosarcoma is a malignant cartilage forming bone tumour for which no effective systemic treatment is available. Previous studies illustrate the need for a better understanding of the role of the IGF pathway in chondrosarcoma to determine if it can be a target for therapy, which was therefore explored in this study. Expression of mediators of IGF1R signalling and phosphorylation status of IRS1 was determined in chondrosarcoma cell lines by qRT-PCR and western blot. The effect of activation and inhibition of IGF1R signalling on downstream targets was assessed by western blot. Ten chondrosarcoma cell lines were treated with OSI-906 (IGF1R and IR dual inhibitor) after which cell proliferation and migration were determined by a viability assay and the xCELLigence system, respectively. In addition, four chondrosarcoma cell lines were treated with a combination of doxorubicin and OSI-906. By immunohistochemistry, IGF1R expression levels were determined in tissue microarrays of 187 cartilage tumours and ten paraffin embedded cell lines. Mediators of IGF1R signalling are heterogeneously expressed and phosphorylated IRS1 was detected in 67 % of the tested chondrosarcoma cell lines, suggesting that IGF1R signalling is active in a subset of chondrosarcoma cell lines. In the cell lines with phosphorylated IRS1, inhibition of IGF1R signalling decreased phosphorylated Akt levels and increased IGF1R expression, but it did not influence MAPK or S6 activity. In line with these findings, treatment with IGF1R/IR inhibitors did not impact proliferation or migration in any of the chondrosarcoma cell lines, even upon stimulation with IGF1. Although synergistic effects of IGF1R/IR inhibition with doxorubicin are described for other cancers, our results demonstrate that this was not the case for chondrosarcoma. In addition, we found minimal IGF1R expression in primary tumours in contrast to the high expression detected in chondrosarcoma cell lines, even if both were derived from the

  6. Reversal of oncogene transformation and suppression of tumor growth by the novel IGF1R kinase inhibitor A-928605

    International Nuclear Information System (INIS)

    Pappano, William N; Sheppard, George S; Donawho, Cherrie; Buchanan, Fritz G; Davidsen, Steven K; Bell, Randy L; Wang, Jieyi; Jung, Paul M; Meulbroek, Jonathan A; Wang, Yi-Chun; Hubbard, Robert D; Zhang, Qian; Grudzien, Meagan M; Soni, Niru B; Johnson, Eric F

    2009-01-01

    The insulin-like growth factor (IGF) axis is an important signaling pathway in the growth and survival of many cell and tissue types. This pathway has also been implicated in many aspects of cancer progression from tumorigenesis to metastasis. The multiple roles of IGF signaling in cancer suggest that inhibition of the pathway might yield clinically effective therapeutics. We describe A-928605, a novel pyrazolo [3,4-d]pyrimidine small molecule inhibitor of the receptor tyrosine kinases (IGF1R and IR) responsible for IGF signal transduction. This compound was first tested for its activity and selectivity via conventional in vitro kinome profiling and cellular IGF1R autophosphorylation. Additionally, cellular selectivity and efficacy of A-928605 were analyzed in an IGF1R oncogene-addicted cell line by proliferation, signaling and microarray studies. Finally, in vivo efficacy of A-928605 was assessed in the oncogene-addicted cell line and in a neuroblastoma model as a single agent as well as in combination with clinically approved therapeutics targeting EGFR in models of pancreatic and non-small cell lung cancers. A-928605 is a selective IGF1R inhibitor that is able to abrogate activation of the pathway both in vitro and in vivo. This novel compound dosed as a single agent is able to produce significant growth inhibition of neuroblastoma xenografts in vivo. A-928605 is also able to provide additive effects when used in combination with clinically approved agents directed against EGFR in non-small cell lung and human pancreatic tumor models. These results suggest that a selective IGF1R inhibitor such as A-928605 may provide a useful clinical therapeutic for IGF pathway affected tumors and warrants further investigation

  7. miR-342-3p suppresses hepatocellular carcinoma proliferation through inhibition of IGF-1R-mediated Warburg effect.

    Science.gov (United States)

    Liu, Wenpeng; Kang, Lei; Han, Juqiang; Wang, Yadong; Shen, Chuan; Yan, Zhifeng; Tai, Yanhong; Zhao, Caiyan

    2018-01-01

    Insulin-like growth factor-1 receptor (IGF-1R) is a well-studied oncogenic factor that promotes cell proliferation and energy metabolism and is overexpressed in numerous cancers including hepatocellular carcinoma (HCC). Aerobic glycolysis is a hallmark of cancer, and drugs targeting its regulators, including IGF-1R, are being developed. However, the mechanisms of IGF-1R inhibition and the physiological significance of the IGF-1R inhibitors in cancer cells are unclear. Cell proliferation was evaluated by cell counting Kit-8 and colony formation assay. Western blot and real-time PCR were accordingly used to detect the relevant proteins, miRNA and gene expression. Luciferase reporter assays were used to illustrate the interaction between miR-342-3p and IGF-1R. The effect of miR-342-3p on glycolysis was determined by glucose uptake, ATP concentration, lactate generation, extracellular acidification rate and oxygen consumption rate assays. In vivo, subcutaneous tumor formation assay and PET were performed in nude mice. In this study, we demonstrate that by directly targeting the 3'-UTR (3'-untranslated regions) of IGF-1R, microRNA-342-3p (miR-342-3p) suppresses IGF-1R-mediated PI3K/AKT/GLUT1 signaling pathway both in vitro and in vivo. Through suppression of IGF-1R, miR-342-3p dampens glycolysis by decreasing glucose uptake, lactate generation, ATP production, and extracellular acidification rate (ECAR), and increasing oxygen consumption rate (OCR) in hepatoma cells. Importantly, glycolysis regulated by miR-342-3p is critical for its regulating HCC growth both in vitro and in vivo. Our findings provide clues regarding the role of miR-342-3p as a tumor suppressor in liver cancer mainly through the inhibition of IGF-1R. Targeting IGF-1R by miR-342-3p could be a potential therapeutic strategy in liver cancer.

  8. A role for IGF-1R-targeted therapies in small-cell lung cancer?

    LENUS (Irish Health Repository)

    Gately, Kathy

    2012-02-01

    BACKGROUND: Small-cell lung cancer (SCLC) is an aggressive disease with a poor prognosis. The insulin-like growth factor-1 receptor (IGF-1R) is an autocrine growth factor and an attractive therapeutic target in many solid tumors, but particularly in lung cancer. PATIENTS AND METHODS: This study examined tumor samples from 23 patients diagnosed with SCLC, 11 resected specimens and 12 nodal biopsies obtained by mediastinoscopy, for expression of IGF-1R using the monoclonal rabbit anti-IGF-1R (clone G11, Ventana Medical Systems, Tucson, AZ) and standard immunohistochemistry (IHC). RESULTS: All 23 tumor samples expressed IGF-1R with a range of stain intensity from weak (1+) to strong (3+). Ten tumors had a score of 3+, 7 tumors 2+, and 6 tumors 1+. Patient survival data were available for all 23 patients. Two patients died < 30 days post biopsy, therefore, the intensity of anti-IGF-1R immunostaining for 21 patients was correlated to survival. Patients with 3+ immunostaining had a poorer prognosis (P = .003). The overall survival of patients who underwent surgical resection was significantly better (median survival not reached) than patients who were not resected (median survival, 7.4 months) (P = .006). CONCLUSION: IGF-1R targeted therapies may have a role in the treatment of SCLC in combination with chemotherapy or as maintenance therapy. Further studies on the clinical benefit of targeting IGF-1R in SCLC are needed.

  9. Optimization of IGF-1R SPECT/CT Imaging Using In-111-Labeled F(ab ')(2) and Fab Fragments of Article the Monoclonal Antibody R1507

    NARCIS (Netherlands)

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

    2012-01-01

    The insulin-like growth factor 1 receptor (IGF-1R) is a potential new target for the treatment of breast cancer. Patients with breast cancer lesions that express IGF-1R may benefit from treatment with anti-IGF-IR antibodies. IGF-1R expression can be visualized using radiolabeled R1507, a monoclonal

  10. Inhibition of tumor growth by targeted anti-EGFR/IGF-1R Nanobullets depends on efficient blocking of cell survival pathways

    NARCIS (Netherlands)

    van der Meel, Roy; Oliveira, Sabrina; Altintas, Isil; Heukers, R.; Pieters, Ebel H.E.; van Bergen en Henegouwen, Paul M.P.; Storm, Gerrit; Hennink, Wim E.; Kok, Robbert J.; Schiffelers, Raymond M.

    2013-01-01

    The clinical efficacy of epidermal growth factor receptor (EGFR)-targeted inhibitors is limited due to resistance mechanisms of the tumor such as activation of compensatory pathways. Crosstalk between EGFR and insulin-like growth factor 1 (IGF-1R) signaling has been frequently described to be

  11. Systemic analysis of different colorectal cancer cell lines and TCGA datasets identified IGF-1R/EGFR-PPAR-CASPASE axis as important indicator for radiotherapy sensitivity.

    Science.gov (United States)

    Chen, Lin; Zhu, Zhe; Gao, Wei; Jiang, Qixin; Yu, Jiangming; Fu, Chuangang

    2017-09-05

    Insulin-like growth factor 1 receptor (IGF-1R) is proved to contribute the development of many types of cancers. But, little is known about its roles in radio-resistance of colorectal cancer (CRC). Here, we demonstrated that low IGF-1R expression value was associated with the better radiotherapy sensitivity of CRC. Besides, through Quantitative Real-time PCR (qRT-PCR), the elevated expression value of epidermal growth factor receptor (EGFR) was observed in CRC cell lines (HT29, RKO) with high radio-sensitivity compared with those with low sensitivity (SW480, LOVO). The irradiation induced apoptosis rates of wild type and EGFR agonist (EGF) or IGF-1R inhibitor (NVP-ADW742) treated HT29 and SW480 cells were quantified by flow cytometry. As a result, the apoptosis rate of EGF and NVP-ADW742 treated HT29 cells was significantly higher than that of those wild type ones, which indicated that high EGFR and low IGF-1R expression level in CRC was associated with the high sensitivity to radiotherapy. We next conducted systemic bioinformatics analysis of genome-wide expression profiles of CRC samples from the Cancer Genome Atlas (TCGA). Differential expression analysis between IGF-1R and EGFR abnormal CRC samples, i.e. CRC samples with higher IGF-1R and lower EGFR expression levels based on their median expression values, and the rest of CRC samples identified potential genes contribute to radiotherapy sensitivity. Functional enrichment of analysis of those differential expression genes (DEGs) in the Database for Annotation, Visualization and Integrated Discovery (DAVID) indicated PPAR signaling pathway as an important pathway for the radio-resistance of CRC. Our study identified the potential biomarkers for the rational selection of radiotherapy for CRC patients. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Chromosome 15 structural abnormalities: effect on IGF1R gene expression and function

    Directory of Open Access Journals (Sweden)

    Rossella Cannarella

    2017-09-01

    Full Text Available Insulin-like growth factor 1 receptor (IGF1R, mapping on the 15q26.3 chromosome, is required for normal embryonic and postnatal growth. The aim of the present study was to evaluate the IGF1R gene expression and function in three unrelated patients with chromosome 15 structural abnormalities. We report two male patients with the smallest 15q26.3 chromosome duplication described so far, and a female patient with ring chromosome 15 syndrome. Patient one, with a 568 kb pure duplication, had overgrowth, developmental delay, mental and psychomotor retardation, obesity, cryptorchidism, borderline low testis volume, severe oligoasthenoteratozoospermia and gynecomastia. We found a 1.8-fold increase in the IGF1R mRNA and a 1.3-fold increase in the IGF1R protein expression (P < 0.05. Patient two, with a 650 kb impure duplication, showed overgrowth, developmental delay, mild mental retardation, precocious puberty, low testicular volume and severe oligoasthenoteratozoospermia. The IGF1R mRNA and protein expression was similar to that of the control. Patient three, with a 46,XX r(15 (p10q26.2 karyotype, displayed intrauterine growth retardation, developmental delay, mental and psychomotor retardation. We found a <0.5-fold decrease in the IGF1R mRNA expression and an undetectable IGF1R activity. After reviewing the previously 96 published cases of chromosome 15q duplication, we found that neurological disorders, congenital cardiac defects, typical facial traits and gonadal abnormalities are the prominent features in patients with chromosome 15q duplication. Interestingly, patients with 15q deletion syndrome display similar features. We speculate that both the increased and decreased IGF1R gene expression may play a role in the etiology of neurological and gonadal disorders.

  13. Crosstalk between TEMs and endothelial cells modulates angiogenesis and metastasis via IGF1-IGF1R signalling in epithelial ovarian cancer.

    Science.gov (United States)

    Wang, Xinjing; Zhu, Qinyi; Lin, Yingying; Wu, Li; Wu, Xiaoli; Wang, Kai; He, Qizhi; Xu, Congjian; Wan, Xiaoping; Wang, Xipeng

    2017-10-24

    Epithelial ovarian cancer (EOC) is the leading cause of death from gynaecologic malignancies and has a poor prognosis due to metastasis. Drugs targeting the angiogenesis pathway significantly improve patient outcome. However, the key factors linking angiogenesis and metastasis have not been elucidated. In this study, we found Tie2 expressing monocytes (CD14 + Tie2 + , TEMs) as key contributors to angiogenesis and metastasis of EOC. Tissue slides were evaluated by immunofluorescence for the presence of total tissue macrophages and TEMs. The correlation between microvascular density (MVD) values and the TEMs number or ratio was calculated in both ovarian cancer tissues and peritoneum. The rate of TEMs in monocytes was evaluated in the peripheral blood of female healthy donors, benign cysts patients, and EOC patients using flow cytometry. The TEMs rate in ascites from EOC patients was also evaluated by flow cytometry. The concentration of Ang2, as the ligand of Tie2, was examined by ELISA in serum samples of EOC patients, benign cysts patients, and ascites samples of EOC patients. The effects of Ang2 on the migration and the cytokine expression of TEMs were further examined. The pro- angiogenesis activity of TEMs via IGF1 was performed in both in vivo and in vitro. And the IGF1 blocking test was performed using neutralising antibody. TEMs were significantly higher in tumour foci, peripheral blood and ascites in EOC patients. The proportion of TEMs among total tissue macrophages was positively correlated with tumour MVD. In vivo animal results showed that TEMs promoted EOC angiogenesis and metastasis. Further functional and mechanisms studies revealed that concentration of angiopoietin 2 (Ang2), a ligand of Tie2, was elevated in EOC ascites which further recruit TEMs in a dose-dependent manner as a powerful chemokine to TEMs. Recruited TEMs promoted endothelial cell function through IGF1-activated downstream signalling. Blocking secreted IGF1 using inhibiting antibody

  14. Elevated insulin-like growth factor 1 receptor signaling induces antiestrogen resistance through the MAPK/ERK and PI3K/Akt signaling routes

    NARCIS (Netherlands)

    Zhang, Y.; Moerkens, M.; Ramaiahgari, S.; Bont, de H.J.G.M.; Price, L.; Meerman, J.H.N.; Water, van de B.

    2011-01-01

    INTRODUCTION: Insulin-like growth factor 1 (IGF-1) receptor (IGF-1R) is phosphorylated in all breast cancer subtypes. Past findings have shown that IGF-1R mediates antiestrogen resistance through cross-talk with estrogen receptor (ER) signaling and via its action upstream of the epidermal growth

  15. Human GH Receptor-IGF-1 Receptor Interaction: Implications for GH Signaling

    Science.gov (United States)

    Gan, Yujun; Buckels, Ashiya; Liu, Ying; Zhang, Yue; Paterson, Andrew J.; Jiang, Jing; Zinn, Kurt R.

    2014-01-01

    GH signaling yields multiple anabolic and metabolic effects. GH binds the transmembrane GH receptor (GHR) to activate the intracellular GHR-associated tyrosine kinase, Janus kinase 2 (JAK2), and downstream signals, including signal transducer and activator of transcription 5 (STAT5) activation and IGF-1 gene expression. Some GH effects are partly mediated by GH-induced IGF-1 via IGF-1 receptor (IGF-1R), a tyrosine kinase receptor. We previously demonstrated in non-human cells that GH causes formation of a GHR-JAK2-IGF-1R complex and that presence of IGF-1R (even without IGF-1 binding) augments proximal GH signaling. In this study, we use human LNCaP prostate cancer cells as a model system to further study the IGF-1R's role in GH signaling. GH promoted JAK2 and GHR tyrosine phosphorylation and STAT5 activation in LNCaP cells. By coimmunoprecipitation and a new split luciferase complementation assay, we find that GH augments GHR/IGF-1R complex formation, which is inhibited by a Fab of an antagonistic anti-GHR monoclonal antibody. Short hairpin RNA-mediated IGF-1R silencing in LNCaP cells reduced GH-induced GHR, JAK2, and STAT5 phosphorylation. Similarly, a soluble IGF-1R extracellular domain fragment (sol IGF-1R) interacts with GHR in response to GH and blunts GH signaling. Sol IGF-1R also markedly inhibits GH-induced IGF-1 gene expression in both LNCaP cells and mouse primary osteoblast cells. On the basis of these and other findings, we propose a model in which IGF-1R augments GH signaling by allowing a putative IGF-1R-associated molecule that regulates GH signaling to access the activated GHR/JAK2 complex and envision sol IGF-1R as a dominant-negative inhibitor of this IGF-1R-mediated augmentation. Physiological implications of this new model are discussed. PMID:25211187

  16. SiRNA-mediated IGF-1R inhibition sensitizes human colon cancer SW480 cells to radiation

    International Nuclear Information System (INIS)

    Yavari, Kamal; Taghikhani, Mohammad; Mesbah-Namin, Seyed A.; Maragheh, Mohammad Ghannadi; Babaei, Mohammad Hosein; Arfaee, Ali Jabbary; Madani, Hossein; Mirzaei, Hamid Reza

    2010-01-01

    Purpose. Insulin like growth factor receptor 1 (IGF-1R) is well-documented to play a key role in radiation response and tumor radiosensitivity, thus offering an attractive clinic drug target to enhance tumor sensitivity to anti-cancer radiotherapy. Material and methods. Human colon carcinoma SW480 cells were transfected with the specific small interference RNA (siRNA) expression vector (pkD-shRNA-IGF-1R-V2) designed to target IGF-1R mRNA. The expression of IGF-1R mRNA and its protein among the transfected and untransfected cells were detected by semi-quantitative RT-PCR and ELISA assay. The changes in cell radiosensitivity were examined by MTT assay. Results. Transfection of mammalian expression vector pkD containing IGF-1R siRNA was shown to reduce IGF-1R mRNA levels by up to 95%. ELISA assay detected a similar inhibition of IGF-1R protein levels in cells transfected with IGF-1R siRNA. SW480 cells transfected with the expression vector for siRNA significantly rendered cells more sensitive to radiation and the highest radiation enhancement ratio was 2.02 ± 0.08. Conclusion. These data provide the first evidence that specific siRNA fragment (pkD-shRNA-IGF-1R-V2) targeting human IGF-1R mRNA is able to enhance colon cancer radiosensitivity. Also results indicated that, combining IGF-1R siRNA and radiation significantly enhances antitumor efficacy compared with either modality alone

  17. Cross-talk between Integrin α6β4 and Insulin-like Growth Factor-1 Receptor (IGF1R) through Direct α6β4 Binding to IGF1 and Subsequent α6β4-IGF1-IGF1R Ternary Complex Formation in Anchorage-independent Conditions*

    OpenAIRE

    Fujita, Masaaki; Ieguchi, Katsuaki; Davari, Parastoo; Yamaji, Satoshi; Taniguchi, Yukimasa; Sekiguchi, Kiyotoshi; Takada, Yoko K.; Takada, Yoshikazu

    2012-01-01

    Background: Integrin αvβ3-extracellular matrix interaction and/or αvβ3 binding to insulin-like growth factor-1 (IGF1; and integrin-IGF1-IGF1 receptor ternary complex formation) is critical for IGF signaling.

  18. TSH-Mediated TNFα Production in Human Fibrocytes Is Inhibited by Teprotumumab, an IGF-1R Antagonist.

    Directory of Open Access Journals (Sweden)

    Hong Chen

    Full Text Available Fibrocytes (FC are bone marrow-derived progenitor cells that are more abundant and infiltrate the thyroid and orbit in Graves orbitopathy (GO. FCs express high levels of thyrotropin receptor (TSHR and insulin-like growth factor-1 receptor (IGF-1R. These receptors are physically and functionally associated, but their role in GO pathogenesis is not fully delineated. Treatment of FCs with thyroid stimulating hormone (TSH or M22 (activating antibody to TSHR induces the production of numerous cytokines, including tumor necrosis factor α (TNFα. Teprotumumab (TMB is a human monoclonal IGF-1R blocking antibody currently in clinical trial for GO and inhibits TSHR-mediated actions in FCs.To characterize the molecular mechanisms underlying TSH-induced TNFα production by FCs, and the role of IGF-1R blockade by TMB.FCs from healthy and GD patients were treated with combinations of TSH, M22, MG132 and AKTi (inhibitors of NF-κB and Akt, respectively, and TMB. TNFα protein production was measured by Luminex and flow cytometry. Messenger RNA expression was quantified by real time PCR.Treatment with TSH/M22 induced TNFα protein and mRNA production by FCs, both of which were reduced when FCs were pretreated with MG132 and AKTi (p<0.0001. TMB decreased TSH-induced TNFα protein production in circulating FCs from mean fluorescent index (MFI value of 2.92 to 1.91, and mRNA expression in cultured FCs from 141- to 52-fold expression (p<0.0001. TMB also decreased M22-induced TNFα protein production from MFI of 1.67 to 1.12, and mRNA expression from 6- to 3-fold expression (p<0.0001.TSH/M22 stimulates FC production of TNFα mRNA and protein. This process involves the transcription factor NF-κB and its regulator Akt. Blocking IGF-1R attenuates TSH/M22-induced TNFα production. This further delineates the interaction of TSHR and IGF1-R signaling pathways. By modulating the proinflammatory properties of FCs such as TNFα production, TMB may be a promising

  19. 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

  20. DNA Methylation Changes in the IGF1R Gene in Birth Weight Discordant Adult Monozygotic Twins

    DEFF Research Database (Denmark)

    Tsai, Pei-Chien; Van Dongen, Jenny; Tan, Qihua

    2015-01-01

    persists into adulthood. To investigate this further, we performed epigenome-wide association analyses of blood DNA methylation using Infinium HumanMethylation450 BeadChip profiles in 71 adult monozygotic (MZ) twin pairs who were extremely discordant for birth weight. A signal mapping to the IGF1R gene (cg...... were not significant. However, a meta-analysis across the four independent samples, in total 216 birth-weight discordant MZ twin pairs, showed a significant positive association between birth weight and DNA methylation differences at IGF1R (random-effects meta-analysis p = .04), and the effect...... was particularly pronounced in older twins (random-effects meta-analysis p = .008, 98 older birth-weight discordant MZ twin pairs). The results suggest that severe intra-uterine growth differences (birth weight discordance >20%) are associated with methylation changes in the IGF1R gene in adulthood, independent...

  1. IGF-I stimulates ERβ and aromatase expression via IGF1R/PI3K/AKT-mediated transcriptional activation in endometriosis.

    Science.gov (United States)

    Zhou, Yan; Zeng, Cheng; Li, Xin; Wu, Pei-Li; Yin, Ling; Yu, Xiao-Lan; Zhou, Ying-Fang; Xue, Qing

    2016-08-01

    Estrogen receptor beta (ERβ, encoded by ESR2 gene) and cytochrome P450 aromatase (encoded by CYP19A1 gene) play critical roles in endometriosis, and the levels of insulin-like growth factor-I (IGF-I) in the peritoneal fluid are significantly higher in patients with endometriosis compared with those in normal women. However, the effects and mechanisms of IGF-I on ERβ and aromatase expression remain to be fully elucidated. In this study, human endometriotic stromal cells (ESCs) and endometrial cells (EMs) derived from ovarian endometriomas and eutopic endometrial tissues. ESCs were cultured with IGF-I, signal pathway inhibitors, and siRNAs. ERβ and aromatase expression were measured by real-time PCR and Western, respectively. The binding of c-Jun and CREB to the ESR2 and CYP19A1 promoters was assessed by chromatin immunoprecipitation assay. Animal experiments were performed in a xenograft mouse model. Levels of IGF-I mRNA in ESCs were markedly higher than those in EMs. IGF-I upregulated ERβ and aromatase expression in ESCs after stimulation of the IGF1R/PI3K/AKT pathway. Following IGF-I treatment, a marked increase in c-Jun and CREB phosphorylation occurred, enhancing binding to the ESR2 and CYP19A1 promoters. An IGF1R inhibitor in vivo reduced IGF-I-induced endometriosis graft growth and ERβ and aromatase expression. In conclusion, this is the first report to describe a mechanistic analysis of ERβ and aromatase expression regulated by IGF-I in ESCs. Moreover, an IGF1R inhibitor impeded ectopic lesion growth in nude mice. These findings suggest that an inhibitor of IGF1R might have therapeutic potential as an antiendometriotic drug. Level of IGF-I mRNA in ESCs is markedly higher than that in EMs. IGF-I up-regulates ERβ and aromatase expression via IGF1R/PI3K/AKT pathway. C-Jun and CREB are recruited to ESR2 or CYP19A1 promoter by IGF-I stimulation. IGF-1R inhibitors in vivo impede the growth of ectopic lesions in nude mice.

  2. IGF1R- and ROR1-Specific CAR T Cells as a Potential Therapy for High Risk Sarcomas.

    Directory of Open Access Journals (Sweden)

    Xin Huang

    Full Text Available Patients with metastatic or recurrent and refractory sarcomas have a dismal prognosis. Therefore, new targeted therapies are urgently needed. This study was designed to evaluate chimeric antigen receptor (CAR T cells targeting the type I insulin-like growth factor receptor (IGF1R or tyrosine kinase-like orphan receptor 1 (ROR1 molecules for their therapeutic potential against sarcomas. Here, we report that IGF1R (15/15 and ROR1 (11/15 were highly expressed in sarcoma cell lines including Ewing sarcoma, osteosarcoma, alveolar or embryonal rhabdomyosarcoma, and fibrosarcoma. IGF1R and ROR1 CAR T cells derived from eight healthy donors using the Sleeping Beauty (SB transposon system were cytotoxic against sarcoma cells and produced high levels of IFN-γ, TNF-α and IL-13 in an antigen-specific manner. IGF1R and ROR1 CAR T cells generated from three sarcoma patients released significant amounts of IFN-γ in response to sarcoma stimulation. The adoptive transfer of IGF1R and ROR1 CAR T cells derived from a sarcoma patient significantly reduced tumor growth in pre-established, systemically disseminated and localized osteosarcoma xenograft models in NSG mice. Infusion of IGF1R and ROR1 CAR T cells also prolonged animal survival in a localized sarcoma model using NOD/scid mice. Our data indicate that both IGF1R and ROR1 can be effectively targeted by SB modified CAR T cells and that such CAR T cells may be useful in the treatment of high risk sarcoma patients.

  3. The impact of IGF-1R expression on the outcomes of patients with breast cancer: a meta-analysis

    Directory of Open Access Journals (Sweden)

    Yan S

    2015-01-01

    Full Text Available Shunchao Yan,1 Xin Jiao,2 Kai Li,1 Wusheng Li,1 Huawei Zou11Department of Oncology, Shengjing Hospital of China Medical University, Shenyang, People’s Republic of China; 2Department of Respiratory Medicine, Shenyang Chest Hospital, Shenyang, People’s Republic of ChinaPurpose: The value of insulin-like growth factor 1 receptor (IGF-1R for predicting survival of patients with breast cancer remains controversial. The purpose of this study was to perform a meta-analysis of the published data to attempt to clarify the impact of IGF-1R.Methods: Studies published between January 1, 1990 and October 1, 2014 were identified using an electronic search to aggregate the available survival results. Studies were included if they reported detecting IGF-1R expression in the primary breast cancer and analyzed patient survival data according to IGF-1R status. The principal outcome measures were hazard ratios (HRs for survival of IGF-1R-positive patients. Combined HRs and 95% confidence intervals (CIs were estimated using fixed- or random-effects models according to between-study heterogeneity.Results: Ten studies, involving 5,406 patients, satisfied our inclusion criteria. Data from five studies provided the impact of IGF-1R on overall survival (OS, three studies the impact on breast cancer-specific survival (BCSS, and seven studies the impact on disease-free survival (DFS. The results of meta-analysis showed that for DFS, membranous IGF-1R positivity was not a significant predictor. The combined HR for OS/BCSS was 0.63 (95% CI: 0.42–0.95, P=0.03, indicating that membranous IGF-1R positivity was a significant predictor of better survival. IGF-1R cytoplasmic positivity was significantly associated with longer DFS and OS/BCSS (combined HR: 0.56, 95% CI: 0.35–0.89, P=0.01; combined HR: 0.55, 95% CI: 0.35–0.85, P=0.008, respectively. The results of subgroup analysis suggested that membranous IGF-1R positivity in hormone-receptor-positive breast cancer was

  4. The impact of IGF-1R expression on the outcomes of patients with breast cancer: a meta-analysis

    Science.gov (United States)

    Yan, Shunchao; Jiao, Xin; Li, Kai; Li, Wusheng; Zou, Huawei

    2015-01-01

    Purpose The value of insulin-like growth factor 1 receptor (IGF-1R) for predicting survival of patients with breast cancer remains controversial. The purpose of this study was to perform a meta-analysis of the published data to attempt to clarify the impact of IGF-1R. Methods Studies published between January 1, 1990 and October 1, 2014 were identified using an electronic search to aggregate the available survival results. Studies were included if they reported detecting IGF-1R expression in the primary breast cancer and analyzed patient survival data according to IGF-1R status. The principal outcome measures were hazard ratios (HRs) for survival of IGF-1R-positive patients. Combined HRs and 95% confidence intervals (CIs) were estimated using fixed- or random-effects models according to between-study heterogeneity. Results Ten studies, involving 5,406 patients, satisfied our inclusion criteria. Data from five studies provided the impact of IGF-1R on overall survival (OS), three studies the impact on breast cancer-specific survival (BCSS), and seven studies the impact on disease-free survival (DFS). The results of meta-analysis showed that for DFS, membranous IGF-1R positivity was not a significant predictor. The combined HR for OS/BCSS was 0.63 (95% CI: 0.42–0.95, P=0.03), indicating that membranous IGF-1R positivity was a significant predictor of better survival. IGF-1R cytoplasmic positivity was significantly associated with longer DFS and OS/BCSS (combined HR: 0.56, 95% CI: 0.35–0.89, P=0.01; combined HR: 0.55, 95% CI: 0.35–0.85, P=0.008, respectively). The results of subgroup analysis suggested that membranous IGF-1R positivity in hormone-receptor-positive breast cancer was correlated with favorable DFS (combined HR: 0.61, 95% CI: 0.41–0.92, P=0.02) and OS/BCSS (combined HR: 0.73, 95% CI: 0.57–0.93, P=0.01). Membranous IGF-1R positivity in triple-negative breast cancer predicted worse DFS (combined HR: 1.86, 95% CI: 1.03–3.34, P=0.04). Membranous

  5. Tumor-targeting magnetic lipoplex delivery of short hairpin RNA suppresses IGF-1R overexpression of lung adenocarcinoma A549 cells in vitro and in vivo.

    Science.gov (United States)

    Wang, Chunmao; Ding, Chao; Kong, Minjian; Dong, Aiqiang; Qian, Jianfang; Jiang, Daming; Shen, Zhonghua

    2011-07-08

    Liposomal magnetofection potentiates gene transfection by applying a magnetic field to concentrate magnetic lipoplexes onto target cells. Magnetic lipoplexes are self-assembling ternary complexes of cationic lipids with plasmid DNA associated with superparamagnetic iron oxide nanoparticles (SPIONs). Type1 insulin-like growth factor receptor (IGF-1R), an important oncogene, is frequently overexpressed in lung cancer and mediates cancer cell proliferation and tumor growth. In this study, we evaluated the transfection efficiency (percentage of transfected cells) and therapeutic potential (potency of IGF-1R knockdown) of liposomal magnetofection of plasmids expressing GFP and shRNAs targeting IGF-1R (pGFPshIGF-1Rs) in A549 cells and in tumor-bearing mice as compared to lipofection using Lipofectamine 2000. Liposomal magnetofection provided a threefold improvement in transgene expression over lipofection and transfected up to 64.1% of A549 cells in vitro. In vitro, IGF-1R specific-shRNA transfected by lipofection inhibited IGF-1R protein by 56.1±6% and by liposomal magnetofection by 85.1±3%. In vivo delivery efficiency of the pGFPshIGF-1R plasmid into the tumor was significantly higher in the liposomal magnetofection group than in the lipofection group. In vivo IGF-1R specific-shRNA by lipofection inhibited IGF-1R protein by an average of 43.8±5.3%; that by liposomal magnetofection inhibited IGF-1R protein by 43.4±5.7%, 56.3±9.6%, and 72.2±6.8%, at 24, 48, and 72 h, respectively, after pGFPshIGF-1R injection. Our findings indicate that liposomal magnetofection may be a promising method that allows the targeting of gene therapy to lung cancer. Copyright © 2011 Elsevier Inc. All rights reserved.

  6. MicroRNA-133a Inhibits Osteosarcoma Cells Proliferation and Invasion via Targeting IGF-1R

    Directory of Open Access Journals (Sweden)

    Guangnan Chen

    2016-02-01

    Full Text Available Background/Aims: MicroRNAs (miRNAs are a class of small noncoding RNAs that regulate gene expression by repressing translation or cleaving RNA transcripts in a sequence-specific manner. Downregulated microRNAs and their roles in cancer development have attracted much attention. A growing body of evidence showed that microRNA-133a (miR-133a has inhibitory effects on cell proliferation, migration, invasion, and metastasis of osteosarcoma. Methods: MiR-133a expression in human osteosarcoma cell lines and human normal osteoblastic cell line hFOB was investigated by real-time PCR (RT-PCR. The role of miR-133a in human osteosarcoma growth and invasion was assessed in cell lines in vitro and in vivo. Then, luciferase reporter assay validated IGF-1R as a downstream and functional target of miR-133a, and functional studies revealed that the anti-tumor effect of miR-133a was probably due to targeting and repressing of IGF-1R expression. Results: MiR-133a was lower expressed in human osteosarcoma cell lines than human normal osteoblastic cell line hFOB and its effect on inhibiting proliferation, invasion and metastasis is mediated by its direct interaction with the IGF-1R. Furthermore, the tumour-suppressive function of miR-133a probably contributed to inhibiting the activation AKT and ERK signaling pathway. Conclusion: MiR-133a suppresses osteosarcoma progression and metastasis by targeting IGF-1R in human osteosarcoma cells, providing a novel candidate prognostic factor and a potential anti-metastasis therapeutic target in osteosarcoma.

  7. Inhibition of p70S6K1 activation by Pdcd4 overcomes the resistance to an IGF-1R/IR inhibitor in colon carcinoma cells

    OpenAIRE

    Zhang, Yan; Wang, Qing; Chen, Li; Yang, Hsin-Sheng

    2015-01-01

    Agents targeting insulin-like growth factor 1 receptor (IGF-1R) are being actively examined in clinical trials. Although there has been some initial success of single agent targeting IGF-1R, attempts in later studies failed due to resistance. This study aimed to understand the effects of programmed cell death 4 (Pdcd4) on the chemosensitivity of the IGF-1R inhibitor, OSI-906, in colorectal cancer (CRC) cells and the mechanism underlying this impact. Using OSI-906 resistant and sensitive CRC c...

  8. Inhibition of IGF1-R overcomes IGFBP7-induced chemotherapy resistance in T-ALL

    International Nuclear Information System (INIS)

    Bartram, Isabelle; Erben, Ulrike; Ortiz-Tanchez, Jutta; Blunert, Katja; Schlee, Cornelia; Neumann, Martin; Heesch, Sandra; Baldus, Claudia D.

    2015-01-01

    T-cell acute lymphoblastic leukemia (T-ALL) is a genetically heterogeneous disease with the need for treatment optimization. Previously, high expression of Insulin-like growth factor binding protein 7 (IGFBP7), a member of the IGF system, was identified as negative prognostic factor in adult T-ALL patients. Since aberrant IGFBP7 expression was observed in a variety of neoplasia and was relevant for prognosis in T-ALL, we investigated the functional role of IGFBP7 in Jurkat and Molt-4 cells as in vitro models for T-ALL. Jurkat and Molt-4 cells were stably transfected with an IGFBP7 over-expression vector or the empty vector as control. Proliferation of the cells was assessed by WST-1 assays and cell cycle status was measured by flow-cytometry after BrDU/7-AAD staining. The effect of IGFBP7 over-expression on sensitivity to cytostatic drugs was determined in AnnexinV/7-AAD assays. IGF1-R protein expression was measured by Western Blot and flow-cytometric analysis. IGF1-R associated gene expression profiles were generated from microarray gene expression data of 86 T-ALL patients from the Microarrays Innovations in Leukemia (MILE) multicenter study. IGFBP7-transfected Jurkat cells proliferated less, leading to a longer survival in a nutrient–limited environment. Both IGFBP7-transfected Jurkat and Molt-4 cells showed an arrest in the G0/G1 cell cycle phase. Furthermore, Jurkat IGFBP7-transfected cells were resistant to vincristine and asparaginase treatment. Surface expression and whole protein measurement of IGF1-R protein expression showed a reduced abundance of the receptor after IGFBP7 transfection in Jurkat cells. Interestingly, combination of the IGF1-R inhibitor NPV-AEW541 restored sensitivity to vincristine in IGFBP7-transfected cells. Additionally, IGF1-R associated GEP revealed an up-regulation of important drivers of T-ALL pathogenesis and regulators of chemo-resistance and apoptosis such as NOTCH1, BCL-2, PRKCI, and TP53. This study revealed a

  9. Tumor-targeting magnetic lipoplex delivery of short hairpin RNA suppresses IGF-1R overexpression of lung adenocarcinoma A549 cells in vitro and in vivo

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Chunmao; Ding, Chao; Kong, Minjian [Department of Cardiothoracic Surgery, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310009 (China); Dong, Aiqiang, E-mail: dr_dongaiqiang@sina.com [Department of Cardiothoracic Surgery, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310009 (China); Qian, Jianfang; Jiang, Daming; Shen, Zhonghua [Department of Cardiothoracic Surgery, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310009 (China)

    2011-07-08

    Highlights: {yields} We compared lipofection with magnetofection about difference of transfection efficiency on delivery a therapeutic gene in vitro and in vivo. {yields} We investigated the difference of shRNA induced by magnetofection and lipofection into A549 cell and subcutaneous tumor to knockdown IGF-1R overexpressed in A549 cell and A549 tumor. {yields} We investigated in vivo shRNA silenced IGF-1R overexpression 24, 48, and 72 h after shRNA intravenous injection into tumor-bearing mice by way of magnetofection and lipofection. {yields} Our results showed that magnetofection could achieve therapeutic gene targeted delivery into special site, which contributed to targeted gene therapy of lung cancers. -- Abstract: Liposomal magnetofection potentiates gene transfection by applying a magnetic field to concentrate magnetic lipoplexes onto target cells. Magnetic lipoplexes are self-assembling ternary complexes of cationic lipids with plasmid DNA associated with superparamagnetic iron oxide nanoparticles (SPIONs). Type1insulin-like growth factor receptor (IGF-1R), an important oncogene, is frequently overexpressed in lung cancer and mediates cancer cell proliferation and tumor growth. In this study, we evaluated the transfection efficiency (percentage of transfected cells) and therapeutic potential (potency of IGF-1R knockdown) of liposomal magnetofection of plasmids expressing GFP and shRNAs targeting IGF-1R (pGFPshIGF-1Rs) in A549 cells and in tumor-bearing mice as compared to lipofection using Lipofectamine 2000. Liposomal magnetofection provided a threefold improvement in transgene expression over lipofection and transfected up to 64.1% of A549 cells in vitro. In vitro, IGF-1R specific-shRNA transfected by lipofection inhibited IGF-1R protein by 56.1 {+-} 6% and by liposomal magnetofection by 85.1 {+-} 3%. In vivo delivery efficiency of the pGFPshIGF-1R plasmid into the tumor was significantly higher in the liposomal magnetofection group than in the

  10. Tumor-targeting magnetic lipoplex delivery of short hairpin RNA suppresses IGF-1R overexpression of lung adenocarcinoma A549 cells in vitro and in vivo

    International Nuclear Information System (INIS)

    Wang, Chunmao; Ding, Chao; Kong, Minjian; Dong, Aiqiang; Qian, Jianfang; Jiang, Daming; Shen, Zhonghua

    2011-01-01

    Highlights: → We compared lipofection with magnetofection about difference of transfection efficiency on delivery a therapeutic gene in vitro and in vivo. → We investigated the difference of shRNA induced by magnetofection and lipofection into A549 cell and subcutaneous tumor to knockdown IGF-1R overexpressed in A549 cell and A549 tumor. → We investigated in vivo shRNA silenced IGF-1R overexpression 24, 48, and 72 h after shRNA intravenous injection into tumor-bearing mice by way of magnetofection and lipofection. → Our results showed that magnetofection could achieve therapeutic gene targeted delivery into special site, which contributed to targeted gene therapy of lung cancers. -- Abstract: Liposomal magnetofection potentiates gene transfection by applying a magnetic field to concentrate magnetic lipoplexes onto target cells. Magnetic lipoplexes are self-assembling ternary complexes of cationic lipids with plasmid DNA associated with superparamagnetic iron oxide nanoparticles (SPIONs). Type1insulin-like growth factor receptor (IGF-1R), an important oncogene, is frequently overexpressed in lung cancer and mediates cancer cell proliferation and tumor growth. In this study, we evaluated the transfection efficiency (percentage of transfected cells) and therapeutic potential (potency of IGF-1R knockdown) of liposomal magnetofection of plasmids expressing GFP and shRNAs targeting IGF-1R (pGFPshIGF-1Rs) in A549 cells and in tumor-bearing mice as compared to lipofection using Lipofectamine 2000. Liposomal magnetofection provided a threefold improvement in transgene expression over lipofection and transfected up to 64.1% of A549 cells in vitro. In vitro, IGF-1R specific-shRNA transfected by lipofection inhibited IGF-1R protein by 56.1 ± 6% and by liposomal magnetofection by 85.1 ± 3%. In vivo delivery efficiency of the pGFPshIGF-1R plasmid into the tumor was significantly higher in the liposomal magnetofection group than in the lipofection group. In vivo IGF-1R

  11. IGF-1/IGF-1R/hsa-let-7c axis regulates the committed differentiation of stem cells from apical papilla

    Science.gov (United States)

    Ma, Shu; Liu, Genxia; Jin, Lin; Pang, Xiyao; Wang, Yanqiu; Wang, Zilu; Yu, Yan; Yu, Jinhua

    2016-01-01

    Insulin-like growth factor-1 (IGF-1) and its receptor IGF-1R play a paramount role in tooth/bone formation while hsa-let-7c actively participates in the osteogenic differentiation of mesenchymal stem cells. However, the interaction between IGF-1/IGF-1R and hsa-let-7c on the committed differentiation of stem cells from apical papilla (SCAPs) remains unclear. In this study, human SCAPs were isolated and treated with IGF-1 and hsa-let-7c over/low-expression viruses. The odonto/osteogenic differentiation of these stem cells and the involvement of mitogen-activated protein kinase (MAPK) pathway were subsequently investigated. Alizarin red staining showed that hsa-let-7c low-expression can significantly promote the mineralization of IGF-1 treated SCAPs, while hsa-let-7c over-expression can decrease the calcium deposition of IGF-1 treated SCAPs. Western blot assay and real-time reverse transcription polymerase chain reaction further demonstrated that the expression of odonto/osteogenic markers (ALP, RUNX2/RUNX2, OSX/OSX, OCN/OCN, COL-I/COL-I, DSPP/DSP, and DMP-1/DMP-1) in IGF-1 treated SCAPs were significantly upregulated in Let-7c-low group. On the contrary, hsa-let-7c over-expression could downregulate the expression of these odonto/osteogenic markers. Moreover, western blot assay showed that the JNK and p38 MAPK signaling pathways were activated in Let-7c-low SCAPs but inhibited in Let-7c-over SCAPs. Together, the IGF-1/IGF-1R/hsa-let-7c axis can control the odonto/osteogenic differentiation of IGF-1-treated SCAPs via the regulation of JNK and p38 MAPK signaling pathways. PMID:27833148

  12. Over-accumulation of nuclear IGF-1 receptor in tumor cells requires elevated expression of the receptor and the SUMO-conjugating enzyme Ubc9

    Energy Technology Data Exchange (ETDEWEB)

    Deng, Hua; Lin, Yingbo; Badin, Margherita; Vasilcanu, Daiana; Stroemberg, Thomas [Department of Oncology and Pathology, The Karolinska Institute, Cancer Center Karolinska, SE-17176 Stockholm (Sweden); Jernberg-Wiklund, Helena [Department of Genetics and Pathology, Rudbeck Laboratory, Uppsala University, Uppsala (Sweden); Sehat, Bita [Department of Oncology and Pathology, The Karolinska Institute, Cancer Center Karolinska, SE-17176 Stockholm (Sweden); Larsson, Olle, E-mail: olle.larsson@ki.se [Department of Oncology and Pathology, The Karolinska Institute, Cancer Center Karolinska, SE-17176 Stockholm (Sweden)

    2011-01-14

    Research highlights: {yields} SUMOylation mediates nuclear translocation of IGF-1R which activates transcription. {yields} Here we show that nuclear IGF-1R over-accumulates in tumor cells. {yields} This requires overexpression of the receptor that is a common feature in tumor cells. {yields} An increased expression of the SUMO ligase Ubc9 seems to be an involved mechanism too. -- Abstract: The insulin-like growth factor 1 receptor (IGF-1R) plays crucial roles in tumor cell growth and is overexpressed in many cancers. IGF-1R's trans-membrane kinase signaling pathways have been well characterized. Very recently, we showed that SUMOylation mediates nuclear translocation of the IGF-1R, and that nuclear IGF-1R (nIGF-1R) binds to enhancer regions and activates transcription. We identified three lysine residues in the {beta}-subunit of the receptor and that mutation of these blocks nuclear translocation and gene activation. Furthermore, accumulation of nIGF-1R was proven strongly dependent on the specific SUMO-conjugating enzyme Ubc9. Here we show that nIGF-1R originates solely from the cell membrane and that phosphorylation of the core tyrosine residues of the receptor kinase is crucial for nuclear accumulation. We also compared the levels of nIGF-1R, measured as nuclear/membrane ratios, in tumor and normal cells. We found that the breast cancer cell line MCF-7 has 13-fold higher amounts of nIGF-1R than breast epithelial cells (IME) which showed only a small amount of nIGF-1R. In comparison, the total expression of IGF-1R was only 3.7- higher in MCF-7. Comparison of several other tumor and normal cell lines showed similar tumor cell over-accumulation of nIGF-1R, exceeding the total receptor expression substantially. Ectopic overexpression (>10-fold) of the receptor increased nIGF-1R in IME cells but not to that high level as in wild type MCF-7. The levels of Ubc9 were higher in all tumor cell lines, compared to the normal cells, and this probably contributes to over

  13. Over-accumulation of nuclear IGF-1 receptor in tumor cells requires elevated expression of the receptor and the SUMO-conjugating enzyme Ubc9

    International Nuclear Information System (INIS)

    Deng, Hua; Lin, Yingbo; Badin, Margherita; Vasilcanu, Daiana; Stroemberg, Thomas; Jernberg-Wiklund, Helena; Sehat, Bita; Larsson, Olle

    2011-01-01

    Research highlights: → SUMOylation mediates nuclear translocation of IGF-1R which activates transcription. → Here we show that nuclear IGF-1R over-accumulates in tumor cells. → This requires overexpression of the receptor that is a common feature in tumor cells. → An increased expression of the SUMO ligase Ubc9 seems to be an involved mechanism too. -- Abstract: The insulin-like growth factor 1 receptor (IGF-1R) plays crucial roles in tumor cell growth and is overexpressed in many cancers. IGF-1R's trans-membrane kinase signaling pathways have been well characterized. Very recently, we showed that SUMOylation mediates nuclear translocation of the IGF-1R, and that nuclear IGF-1R (nIGF-1R) binds to enhancer regions and activates transcription. We identified three lysine residues in the β-subunit of the receptor and that mutation of these blocks nuclear translocation and gene activation. Furthermore, accumulation of nIGF-1R was proven strongly dependent on the specific SUMO-conjugating enzyme Ubc9. Here we show that nIGF-1R originates solely from the cell membrane and that phosphorylation of the core tyrosine residues of the receptor kinase is crucial for nuclear accumulation. We also compared the levels of nIGF-1R, measured as nuclear/membrane ratios, in tumor and normal cells. We found that the breast cancer cell line MCF-7 has 13-fold higher amounts of nIGF-1R than breast epithelial cells (IME) which showed only a small amount of nIGF-1R. In comparison, the total expression of IGF-1R was only 3.7- higher in MCF-7. Comparison of several other tumor and normal cell lines showed similar tumor cell over-accumulation of nIGF-1R, exceeding the total receptor expression substantially. Ectopic overexpression (>10-fold) of the receptor increased nIGF-1R in IME cells but not to that high level as in wild type MCF-7. The levels of Ubc9 were higher in all tumor cell lines, compared to the normal cells, and this probably contributes to over-accumulation of nIGF-1R

  14. IGF-1 receptor haploinsufficiency leads to age-dependent development of metabolic syndrome.

    Science.gov (United States)

    Thakur, Sachin; Garg, Neha; Zhang, Ning; Hussey, Sophie E; Musi, Nicolas; Adamo, Martin L

    2017-05-13

    Individuals born small for gestational age (SGA) are at a higher risk of developing the metabolic syndrome later in life. IGF-1 resistance has been reported in placentae from SGA births and mutations in the Igf1 receptor gene have been reported in several cohorts of SGA subjects. We have used the Igf1r heterozygous (Igf1r +/- ) male mouse as a model to investigate the mechanisms by which Igf1r haploinsufficiency leads to insulin resistance. Despite exhibiting IGF-1 resistance, insulin signaling is enhanced in young Igf1r +/- mice but is attenuated in the muscle of old Igf1r +/- mice. Although smaller than WT (wild type) mice, old-aged Igf1r +/- had increased adiposity and exhibit increased lipogenesis. We hypothesize that IGF-1 resistance initially causes a transient increase in insulin signaling thereby promoting a lipogenic phenotype, which subsequently leads to insulin resistance. Copyright © 2017. Published by Elsevier Inc.

  15. IGF-1R/MDM2 relationship confers enhanced sensitivity to RITA in Ewing sarcoma cells.

    Science.gov (United States)

    Di Conza, Giusy; Buttarelli, Marianna; Monti, Olimpia; Pellegrino, Marsha; Mancini, Francesca; Pontecorvi, Alfredo; Scotlandi, Katia; Moretti, Fabiola

    2012-06-01

    Ewing sarcoma is one of the most frequent bone cancers in adolescence. Although multidisciplinary therapy has improved the survival rate for localized tumors, a critical step is the development of new drugs to improve the long-term outcome of recurrent and metastatic disease and to reduce side effects of conventional therapy. Here, we show that the small molecule reactivation of p53 and induction of tumor cell apoptosis (RITA, NSC652287) is highly effective in reducing growth and tumorigenic potential of Ewing sarcoma cell lines. These effects occur both in the presence of wt-p53 as well as of mutant or truncated forms of p53, or in its absence, suggesting the presence of additional targets in this tumor histotype. Further experiments provided evidence that RITA modulates an important oncogenic mark of these cell lines, insulin-like growth factor receptor 1 (IGF-1R). Particularly, RITA causes downregulation of IGF-1R protein levels. MDM2 degradative activity is involved in this phenomenon. Indeed, inhibition of MDM2 function by genetic or pharmacologic approaches reduces RITA sensitivity of Ewing sarcoma cell lines. Overall, these data suggest that in the cell context of Ewing sarcoma, RITA may adopt additional mechanism of action besides targeting p53, expanding its field of application. Noteworthy, these results envisage the promising utilization of RITA or its derivative as a potential treatment for Ewing sarcomas. ©2012 AACR

  16. Type 1 IGF receptor translocates to the nucleus of human tumor cells

    OpenAIRE

    Aleksic, Tamara; Chitnis, Meenali M.; Perestenko, Olga V.; Gao, Shan; Thomas, Peter H.; Turner, Gareth D.; Protheroe, Andrew S.; Howarth, Mark; Macaulay, Valentine M.

    2010-01-01

    The type 1 insulin-like growth factor receptor (IGF-1R) is a transmembrane glycoprotein comprising two extracellular α subunits and two β subunits with tyrosine kinase activity. The IGF-1R is frequently upregulated in cancers, and signals from the cell surface to promote proliferation and cell survival. Recent attention has focused on the IGF-1R as a target for cancer treatment. Here we report that the nuclei of human tumor cells contain IGF-1R, detectable using multiple antibodies to α- and ...

  17. 18FDG-PET predicts pharmacodynamic response to OSI-906, a dual IGF-1R/IR inhibitor, in preclinical mouse models of lung cancer.

    Science.gov (United States)

    McKinley, Eliot T; Bugaj, Joseph E; Zhao, Ping; Guleryuz, Saffet; Mantis, Christine; Gokhale, Prafulla C; Wild, Robert; Manning, H Charles

    2011-05-15

    To evaluate 2-deoxy-2-[(18)F]fluoro-d-glucose positron emission tomography imaging ((18)FDG-PET) as a predictive, noninvasive, pharmacodynamic (PD) biomarker of response following administration of a small-molecule insulin-like growth factor-1 receptor and insulin receptor (IGF-1R/IR) inhibitor, OSI-906. In vitro uptake studies of (3)H-2-deoxy glucose following OSI-906 exposure were conducted evaluating correlation of dose with inhibition of IGF-1R/IR as well as markers of downstream pathways and glucose metabolism. Similarly, in vivo PD effects were evaluated in human tumor cell line xenografts propagated in athymic nude mice by (18)FDG-PET at 2, 4, and 24 hours following a single treatment of OSI-906 for the correlation of inhibition of receptor targets and downstream markers. Uptake of (3)H-2-deoxy glucose and (18)FDG was significantly diminished following OSI-906 exposure in sensitive tumor cells and subcutaneous xenografts (NCI-H292) but not in an insensitive model lacking IGF-1R expression (NCI-H441). Diminished PD (18)FDG-PET, collected immediately following the initial treatment agreed with inhibition of pIGF-1R/pIR, reduced PI3K (phosphoinositide 3-kinase) and MAPK (mitogen activated protein kinase) pathway activity, and predicted tumor growth arrest as measured by high-resolution ultrasound imaging. (18)FDG-PET seems to serve as a rapid, noninvasive PD marker of IGF-1R/IR inhibition following a single dose of OSI-906 and should be explored clinically as a predictive clinical biomarker in patients undergoing IGF-1R/IR-directed cancer therapy. ©2011 AACR.

  18. IGF-1R and ErbB3/HER3 contribute to enhanced proliferation and carcinogenesis in trastuzumab-resistant ovarian cancer model

    International Nuclear Information System (INIS)

    Jia, Yanhan; Zhang, Yan; Qiao, Chunxia; Liu, Guijun; Zhao, Qing; Zhou, Tingting; Chen, Guojiang; Li, Yali; Feng, Jiannan; Li, Yan; Zhang, Qiuping; Peng, Hui

    2013-01-01

    Highlights: •We established trastuzumab-resistant cell line SKOV3/T. •SKOV3/T enhances proliferation and in vivo carcinogenesis. •IGF-1R and HER3 genes were up-regulated in SKOV3/T based on microarray analysis. •Targeting IGF-1R and/or HER3 inhibited the proliferation of SKOV3/T. •Therapies targeting IGF-1R and HER3 might be effective in ovarian cancer. -- Abstract: Trastuzumab (Herceptin®) has demonstrated clinical potential in several types of HER2-overexpressing human cancers. However, primary and acquired resistance occurs in many HER2-positive patients with regimens. To investigate the possible mechanism of acquired therapeutic resistance to trastuzumab, we have developed a preclinical model of human ovarian cancer cells, SKOV3/T, with the distinctive feature of stronger carcinogenesis. The differences in gene expression between parental and the resistant cells were explored by microarray analysis, of which IGF-1R and HER3 were detected to be key molecules in action. Their correctness was validated by follow-up experiments of RT-PCR, shRNA-mediated knockdown, downstream signal activation, cell cycle distribution and survival. These results suggest that IGF-1R and HER3 differentially regulate trastuzumab resistance and could be promising targets for trastuzumab therapy in ovarian cancer

  19. IGF-1R and ErbB3/HER3 contribute to enhanced proliferation and carcinogenesis in trastuzumab-resistant ovarian cancer model

    Energy Technology Data Exchange (ETDEWEB)

    Jia, Yanhan [Department of Immunology, School of Basic Medical Sciences, Wuhan University, Wuhan, Hubei 430071 (China); Department of Immunology, Institute of Basic Medical Sciences, Beijing 100850 (China); Zhang, Yan [Department of Gynaecology and Obstetrics, PLA General Hospital, Beijing 100853 (China); Qiao, Chunxia; Liu, Guijun [Department of Immunology, Institute of Basic Medical Sciences, Beijing 100850 (China); Zhao, Qing [Department of Immunology, Institute of Basic Medical Sciences, Beijing 100850 (China); Department of Gynaecology and Obstetrics, PLA General Hospital, Beijing 100853 (China); Zhou, Tingting; Chen, Guojiang [Department of Immunology, Institute of Basic Medical Sciences, Beijing 100850 (China); Li, Yali [Department of Gynaecology and Obstetrics, PLA General Hospital, Beijing 100853 (China); Feng, Jiannan; Li, Yan [Department of Immunology, Institute of Basic Medical Sciences, Beijing 100850 (China); Zhang, Qiuping, E-mail: qpzhang@whu.edu.cn [Department of Immunology, School of Basic Medical Sciences, Wuhan University, Wuhan, Hubei 430071 (China); Peng, Hui, E-mail: p_h2002@hotmail.com [Department of Immunology, Institute of Basic Medical Sciences, Beijing 100850 (China); Cardiovascular Drug Research Center, Institute of Health and Environmental Medicine, Beijing 100850 (China)

    2013-07-12

    Highlights: •We established trastuzumab-resistant cell line SKOV3/T. •SKOV3/T enhances proliferation and in vivo carcinogenesis. •IGF-1R and HER3 genes were up-regulated in SKOV3/T based on microarray analysis. •Targeting IGF-1R and/or HER3 inhibited the proliferation of SKOV3/T. •Therapies targeting IGF-1R and HER3 might be effective in ovarian cancer. -- Abstract: Trastuzumab (Herceptin®) has demonstrated clinical potential in several types of HER2-overexpressing human cancers. However, primary and acquired resistance occurs in many HER2-positive patients with regimens. To investigate the possible mechanism of acquired therapeutic resistance to trastuzumab, we have developed a preclinical model of human ovarian cancer cells, SKOV3/T, with the distinctive feature of stronger carcinogenesis. The differences in gene expression between parental and the resistant cells were explored by microarray analysis, of which IGF-1R and HER3 were detected to be key molecules in action. Their correctness was validated by follow-up experiments of RT-PCR, shRNA-mediated knockdown, downstream signal activation, cell cycle distribution and survival. These results suggest that IGF-1R and HER3 differentially regulate trastuzumab resistance and could be promising targets for trastuzumab therapy in ovarian cancer.

  20. Igf1r+/CD34+ immature ICC are putative adult progenitor cells, identified ultrastructurally as fibroblast-like ICC in Ws/Ws rat colon

    DEFF Research Database (Denmark)

    Wang, X Y; Albertí, E; White, E J

    2009-01-01

    by ICC in the wild-type rat colon, suggesting them to be immature ICC. In addition, a marked increase in immunoreactivity for insulin-like growth factor 1 receptor (Igf1r) occurred, co-localized with CD34 but not with c-Kit. A significantly higher number of Igf1r(+)/CD34(+) cells were found in Ws....../Ws compared to wild-type rat colons. These CD34(+)/Igf1r(+) cells in the Ws/Ws colon occupied the same space as FL-ICC. Hence we propose that a subset of immature ICC (FL-ICC) consists of adult progenitor cells. Immunohistochemistry revealed a reduction of neurons positive for neuronal nitric oxide synthase...

  1. Targeting both IGF-1R and mTOR synergistically inhibits growth of renal cell carcinoma in vitro

    International Nuclear Information System (INIS)

    Cardillo, Thomas M; Trisal, Preeti; Arrojo, Roberto; Goldenberg, David M; Chang, Chien-Hsing

    2013-01-01

    Advanced or metastatic renal cell carcinoma (RCC) has a poor prognosis, because it is relatively resistant to conventional chemotherapy or radiotherapy. Treatments with human interferon-α2b alone or in combination with mammalian target of rapamycin (mTOR) inhibitors have led to only a modest improvement in clinical outcome. One observation made with mTOR inhibitors is that carcinomas can overcome these inhibitory effects by activating the insulin-like growth factor-I (IGF-I) signaling pathway. Clinically, there is an association of IGF-I receptor (IGF-IR) expression in RCC and poor long-term patient survival. We have developed a humanized anti-IGF-IR monoclonal antibody, hR1, which binds to RCC, resulting in effective down-regulation of IGF-IR and moderate inhibition of cell proliferation in vitro. In this work, we evaluate the anti-tumor activity of two novel IGF-1R-targeting agents against renal cell carcinoma given alone or in combination with an mTOR inhibitor. hR1 was linked by the DOCK-AND-LOCK™ (DNL™) method to four Fabs of hR1, generating Hex-hR1, or to four molecules of interferon-α2b, generating 1R-2b. Eight human RCC cell lines were screened for IGF-1R expression and sensitivity to treatment with hR1 in vitro. Synergy with an mTOR inhibitor, temsirolimus, was tested in a cell line (ACHN) with low sensitivity to hR1. Hex-hR1 induced the down-regulation of IGF-IR at 10-fold lower concentrations compared to the parental hR1. Sensitivity to growth inhibition mediated by hR1 and Hex-hR1 treatments correlated with IGF-1R expression (higher expression was more sensitive). The potency of 1R-2b to inhibit the in vitro growth of RCC was also demonstrated in two human cell lines, ACHN and 786-O, with EC 50 –values of 63 and 48 pM, respectively. When combined with temsirolimus, a synergistic growth-inhibition with hR1, Hex-hR1, and 1R-2b was observed in ACHN cells at concentrations as low as 10 nM for hR1, 1 nM for Hex-hR1, and 2.6 nM for 1R-2b. Both Hex-hR1

  2. In vitro and in vivo studies of the combination of IGF1R inhibitor figitumumab (CP-751,871) with HER2 inhibitors trastuzumab and neratinib.

    Science.gov (United States)

    Chakraborty, Ashok K; Zerillo, Cynthia; DiGiovanna, Michael P

    2015-08-01

    The insulin-like growth factor I receptor (IGF1R) has been linked to resistance to HER2-directed therapy with trastuzumab (Herceptin). We examined the anti-tumor activity of figitumumab (CP-751,871), a human monoclonal antibody that blocks IGF1R ligand binding, alone and in combination with the therapeutic anti-HER2 antibody trastuzumab and the pan-HER family tyrosine kinase inhibitor neratinib, using in vitro and in vivo breast cancer model systems. In vitro assays of proliferation, apoptosis, and signaling, and in vivo anti-tumor experiments were conducted in HER2-overexpressing (BT474) and HER2-normal (MCF7) models. We find single-agent activity of the HER2-targeting drugs but not figitumumab in the BT474 model, while the reverse is true in the MCF7 model. However, in both models, combining figitumumab with HER2-targeting drugs shows synergistic anti-proliferative and apoptosis-inducing effects, and optimum inhibition of downstream signaling. In murine xenograft models, synergistic anti-tumor effects were observed in the HER2-normal MCF7 model for the combination of figitumumab with trastuzumab, and, in the HER2-overexpressing BT474 model, enhanced anti-tumor effects were observed for the combination of figitumumab with either trastuzumab or neratinib. Analysis of tumor extracts from the in vivo experiments showed evidence of the most optimal inhibition of downstream signaling for the drug combinations over the single-agent therapies. These results suggest promise for such combinations in treating patients with breast cancer, and that, unlike the case for single-agent therapy, the therapeutic effects of such combinations may be independent of expression levels of the individual receptors or the single-agent activity profile.

  3. Targeting non-small cell lung cancer cells by dual inhibition of the insulin receptor and the insulin-like growth factor-1 receptor.

    Directory of Open Access Journals (Sweden)

    Emma E Vincent

    Full Text Available Phase III trials of the anti-insulin-like growth factor-1 receptor (IGF1R antibody figitumumab in non-small cell lung cancer (NSCLC patients have been discontinued owing to lack of survival benefit. We investigated whether inhibition of the highly homologous insulin receptor (IR in addition to the IGF1R would be more effective than inhibition of the IGF1R alone at preventing the proliferation of NSCLC cells. Signalling through IGF1R and IR in the NSCLC cell lines A549 and Hcc193 was stimulated by a combination of IGF1, IGF2 and insulin. It was inhibited by antibodies that block ligand binding, αIR3 (IGF1R and IR47-9 (IR, and by the ATP-competitive small molecule tyrosine kinase inhibitors AZ12253801 and NVPAWD742 which inhibit both IGF1R and IR tyrosine kinases. The effect of inhibitors was determined by an anchorage-independent proliferation assay and by analysis of Akt phosphorylation. In Hcc193 cells the reduction in cell proliferation and Akt phosphorylation due to anti-IGF1R antibody was enhanced by antibody-mediated inhibition of the IR whereas in A549 cells, with a relatively low IR:IGF1R expression ratio, it was not. In each cell line proliferation and Akt phosphorylation were more effectively inhibited by AZ12253801 and NVPAWD742 than by combined αIR3 and IR47-9. When the IGF1R alone is inhibited, unencumbered signalling through the IR can contribute to continued NSCLC cell proliferation. We conclude that small molecule inhibitors targeting both the IR and IGF1R more effectively reduce NSCLC cell proliferation in a manner independent of the IR:IGF1R expression ratio, providing a therapeutic rationale for the treatment of this disease.

  4. MicroRNA-214 Reduces Insulin-like Growth Factor-1 (IGF-1) Receptor Expression and Downstream mTORC1 Signaling in Renal Carcinoma Cells*

    Science.gov (United States)

    Das, Falguni; Dey, Nirmalya; Bera, Amit; Kasinath, Balakuntalam S.; Ghosh-Choudhury, Nandini; Choudhury, Goutam Ghosh

    2016-01-01

    Elevated IGF-1/insulin-like growth factor-1 receptor (IGF-1R) autocrine/paracrine signaling in patients with renal cell carcinoma is associated with poor prognosis of the disease independent of their von Hippel-Lindau (VHL) status. Increased expression of IGF-1R in renal cancer cells correlates with their potency of tumor development and progression. The mechanism by which expression of IGF-1R is increased in renal carcinoma is not known. We report that VHL-deficient and VHL-positive renal cancer cells possess significantly decreased levels of mature, pre-, and pri-miR-214 than normal proximal tubular epithelial cells. We identified an miR-214 recognition element in the 3′UTR of IGF-1R mRNA and confirmed its responsiveness to miR-214. Overexpression of miR-214 decreased the IGF-1R protein levels, resulting in the inhibition of Akt kinase activity in both types of renal cancer cells. IGF-1 provoked phosphorylation and inactivation of PRAS40 in an Akt-dependent manner, leading to the activation of mTORC1 signal transduction to increase phosphorylation of S6 kinase and 4EBP-1. Phosphorylation-deficient mutants of PRAS40 and 4EBP-1 significantly inhibited IGF-1R-driven proliferation of renal cancer cells. Expression of miR-214 suppressed IGF-1R-induced phosphorylation of PRAS40, S6 kinase, and 4EBP-1, indicating inhibition of mTORC1 activity. Finally, miR-214 significantly blocked IGF-1R-forced renal cancer cell proliferation, which was reversed by expression of 3′UTR-less IGF-1R and constitutively active mTORC1. Together, our results identify a reciprocal regulation of IGF-1R levels and miR-214 expression in renal cancer cells independent of VHL status. Our data provide evidence for a novel mechanism for IGF-1R-driven renal cancer cell proliferation involving miR-214 and mTORC1. PMID:27226530

  5. IGF-1R Promotes Symmetric Self-Renewal and Migration of Alkaline Phosphatase+ Germ Stem Cells through HIF-2α-OCT4/CXCR4 Loop under Hypoxia

    Directory of Open Access Journals (Sweden)

    Yung-Che Kuo

    2018-02-01

    Full Text Available Summary: Hypoxia cooperates with endocrine signaling to maintain the symmetric self-renewal proliferation and migration of embryonic germline stem cells (GSCs. However, the lack of an appropriate in vitro cell model has dramatically hindered the understanding of the mechanism underlying this cooperation. Here, using a serum-free system, we demonstrated that hypoxia significantly induced the GSC mesenchymal transition, increased the expression levels of the pluripotent transcription factor OCT4 and migration-associated proteins (SDF-1, CXCR4, IGF-1, and IGF-1R, and activated the cellular expression and translocalization of the CXCR4-downstream proteins ARP3/pFAK. The underlying mechanism involved significant IGF-1/IGF-1R activation of OCT4/CXCR4 expression through HIF-2α regulation. Picropodophyllin-induced inhibition of IGF-1R phosphorylation significantly suppressed hypoxia-induced SDF-1/CXCR4 expression and cell migration. Furthermore, transactivation between IGF-1R and CXCR4 was involved. In summary, we demonstrated that niche hypoxia synergistically cooperates with its associated IGF-1R signaling to regulate the symmetric division (self-renewal proliferation and cell migration of alkaline phosphatase-positive GSCs through HIF-2α-OCT4/CXCR4 during embryogenesis. : In this article, Huang and colleagues demonstrate that niche hypoxia promotes symmetric self-renewal proliferation and migration of PGC-like CD49f+AP+GSCs through IGF-IR regulation. Using a serum-free culture system, the crosstalk between IGF-1R and CXCR4 signaling was discovered. This work demonstrated that embryonic hypoxia synergistically cooperated with IGF-1R signaling to regulate the symmetric self-renewal and migration of PGC-like GSCs through a HIF-2α–OCT4/CXCR4 loop. Keywords: hypoxia, niche, germline stem cells, self-renewal, migration, IGF-1R, HIF-2α, OCT4, SDF-1, CXCR4

  6. Essential role of flotillin-1 palmitoylation in the intracellular localization and signaling function of IGF-1 receptor.

    Science.gov (United States)

    Jang, Donghwan; Kwon, Hayeong; Jeong, Kyuho; Lee, Jaewoong; Pak, Yunbae

    2015-06-01

    Here, we explored flotillin-1-mediated regulation of insulin-like growth factor-1 (IGF-1) signaling. Flotillin-1-deficient cells exhibited a reduction in the activation of IGF-1 receptor (IGF-1R), ERK1/2 and Akt pathways, and the transcriptional activation of Elk-1 and the proliferation in response to IGF-1 were reduced in these cells. We found that IGF-1-independent flotillin-1 palmitoylation at Cys34 in the endoplasmic reticulum (ER) was required for the ER exit and the plasma membrane localization of flotillin-1 and IGF-1R. IGF-1-dependent depalmitoylation and repalmitoylation of flotillin-1 sustained tyrosine kinase activation of the plasma-membrane-targeted IGF-1R. Dysfunction and blocking the turnover of flotillin-1 palmitoylation abrogated cancer cell proliferation after IGF-1R signaling activation. Our data show that flotillin-1 palmitoylation is a new mechanism by which the intracellular localization and activation of IGF-1R are controlled. © 2015. Published by The Company of Biologists Ltd.

  7. miR-139 is up-regulated in osteoarthritis and inhibits chondrocyte proliferation and migration possibly via suppressing EIF4G2 and IGF1R

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Weihua; Zhang, Weikai; Li, Feng; Guo, Fengjing; Chen, Anmin, E-mail: chenanmin6072@126.com

    2016-05-27

    Osteoarthritis (OA) is one of the most progressive articular cartilage erosions. microRNAs (miRNAs) play pivotal roles in OA modulation, but the role of miR-139 in OA remains elusive. This study aims to reveal the effects and possible mechanism of miR-139 in OA and chondrocytes. The levels of miR-139 and its possible targets eukaryotic translation initiation factor 4 gamma 2 (EIF4G2) and insulin-like growth factor 1 receptor (IGF1R) were detected by qRT-PCR in the articular cartilages of 20 OA patients and 20 non-OA patients. Human chondrocyte CHON-001 cells were transfected with miR-139 mimic or inhibitor, as well as the siRNAs of EIF4G2 and IGF1R. Cell viability by MTT assay, proliferation by colony formation assay and migration by Transwell assay were performed. Results showed that miR-139 was up-regulated, while EIF4G2 and IGF1R mRNAs down-regulated in OA cartilages (P < 0.001), and negative correlations existed between the level of miR-139 and EIF4G2 or IGF1R. Overexpression of miR-139 in CHON-001 cells suppressed both mRNA and protein levels of EIF4G2 and IGF1R, and inhibited cell viability, colony formation number and cell migration, while miR-139 inhibitor induced the opposite effects. Knockdown of EIF4G2 or IGF1R in CHON-001 cells reversed the effects of miR-139 inhibitor on cell viability, colony formation and cell migration. These results indicate that miR-139 is capable of inhibiting chondrocyte proliferation and migration, thus being a possible therapeutic target for OA. The mechanism of miR-139 in chondrocytes may be related to its regulation on EIF4G2 and IGF1R.

  8. IGF-1R Regulates the Extracellular Level of Active MMP-2, Pathological Neovascularization, and Functionality in Retinas of OIR Mouse Model.

    Science.gov (United States)

    Lorenc, Valeria E; Subirada Caldarone, Paula V; Paz, María C; Ferrer, Darío G; Luna, José D; Chiabrando, Gustavo A; Sánchez, María C

    2018-02-01

    In ischemic proliferative diseases such as retinopathies, persistent hypoxia leads to the release of numerous neovascular factors that participate in the formation of abnormal vessels and eventually cause blindness. The upregulation and activation of metalloproteinases (MMP-2 and MMP-9) represent a final common pathway in this process. Although many regulators of the neovascular process have been identified, the complete role of the insulin-like growth factor 1 (IGF-1) and its receptor (IGF-1R) appears to be significantly more complex. In this study, we used an oxygen-induced retinopathy (OIR) mouse model as well as an in vitro model of hypoxia to study the role of MMP-2 derived from Müller glial cells (MGCs) and its relation with the IGF-1/IGF-1R system. We demonstrated that MMP-2 protein expression increased in P17 OIR mice, which coincided with the active phase of the neovascular process. Also, glutamine synthetase (GS)-positive cells were also positive for MMP-2, whereas IGF-1R was expressed by GFAP-positive cells, indicating that both proteins were expressed in MGCs. In addition, in the OIR model a single intravitreal injection of the IGF-1R blocking antibody (αIR3) administered at P12 effectively prevented pathologic neovascularization, accelerated physiological revascularization, and improved retinal functionality at P17. Finally, in MGC supernatants, the blocking antibody abolished the IGF-1 effect on active MMP-2 under normoxic and hypoxic conditions without affecting the extracellular levels of pro-MMP-2. These results demonstrate, for the first time, that the IGF-1/IGF-1R system regulates active MMP-2 levels in MGCs, thus contributing to MEC remodeling during the retinal neovascular process.

  9. Inhibition of p70S6K1 Activation by Pdcd4 Overcomes the Resistance to an IGF-1R/IR Inhibitor in Colon Carcinoma Cells.

    Science.gov (United States)

    Zhang, Yan; Wang, Qing; Chen, Li; Yang, Hsin-Sheng

    2015-03-01

    Agents targeting insulin-like growth factor 1 receptor (IGF-1R) are being actively examined in clinical trials. Although there has been some initial success of single-agent targeting IGF-1R, attempts in later studies failed because of resistance. This study aimed to understand the effects of programmed cell death 4 (Pdcd4) on the chemosensitivity of the IGF-1R inhibitor OSI-906 in colorectal cancer cells and the mechanism underlying this impact. Using OSI-906-resistant and -sensitive colorectal cancer cells, we found that the Pdcd4 level directly correlates with cell chemosensitivity to OSI-906. In addition, tumors derived from Pdcd4 knockdown cells resist the growth inhibitory effect of OSI-906 in a colorectal cancer xenograft mouse model. Moreover, Pdcd4 enhances the antiproliferative effect of OSI-906 in resistant cells through suppression of p70S6K1 activation. Knockdown of p70S6K1, but not p70S6K2, significantly increases the chemosensitivity of OSI-906 in cultured colorectal cancer cells. Furthermore, the combination of OSI-906 and PF-4708671, a p70S6K1 inhibitor, efficiently suppresses the growth of OSI-906-resistant colon tumor cells in vitro and in vivo. Taken together, activation of p70S6K1 that is inhibited by Pdcd4 is essential for resistance to the IGF-1R inhibitor in colon tumor cells, and the combinational treatment of OSI-906 and PF-4708671 results in enhanced antiproliferation effects in colorectal cancer cells in vitro and in vivo, providing a novel venue to overcome the resistance to the IGF-1R inhibitor in treating colorectal cancer. ©2015 American Association for Cancer Research.

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

    International Nuclear Information System (INIS)

    Kato, Haruo; Sekine, Yoshitaka; Furuya, Yosuke; Miyazawa, Yoshiyuki; Koike, Hidekazu; Suzuki, Kazuhiro

    2015-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-05-22

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

  12. IGF-1 receptor and IGF binding protein-3 might predict prognosis of patients with resectable pancreatic cancer

    International Nuclear Information System (INIS)

    Hirakawa, Toshiki; Yashiro, Masakazu; Murata, Akihiro; Hirata, Keiichiro; Kimura, Kenjiro; Amano, Ryosuke; Yamada, Nobuya; Nakata, Bunzo; Hirakawa, Kosei

    2013-01-01

    The present study aimed to elucidate the clinicopathologic role of insulin-like growth factor-1 receptor (IGF1R) and IGF binding protein-3 (IGFBP3) in patients with pancreatic cancer. The function of IGFBP3 is controversial, because both inhibition and facilitation of the action of IGF as well as IGF-independent effects have been reported. In this study, IGF1R and IGFBP3 expression was examined, and their potential roles as prognostic markers in patients with pancreatic cancer were evaluated. Clinicopathological features of 122 patients with curatively resected pancreatic cancer were retrospectively reviewed, and expression of IGF1R and IGFBP3 was immunohistochemically analyzed. Expression of IGF1R and IGFBP3 was observed in 50 (41.0%) and 37 (30.3%) patients, respectively. IGF1R expression was significantly associated with histological grade (p = 0.037). IGFBP3 expression had a significant association with tumor location (p = 0.023), and a significant inverse association with venous invasion (p = 0.037). Tumors with IGF1R-positive and IGFBP3-negative expression (n = 32) were significantly frequently Stage II and III (p = 0.011). The prognosis for IGF1R positive patients was significantly poorer than that for IGF1R negative patients (p = 0.0181). IGFBP3 protein expression did not correlate significantly with patient survival. The subset of patients with both positive IGF1R and negative IGFBP3 had worse overall survival (8.8 months versus 12.6 months, respectively, p < 0.001). IGF1R signaling might be associated with tumor aggressiveness, and IGFBP3 might show antiproliferative effects in pancreatic cancer. Both high IGF1R expression and low IGFBP3 expression represent useful prognostic markers for patients with curatively resected pancreatic cancer

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

    Directory of Open Access Journals (Sweden)

    Yu-Chieh Wu

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

  14. Role of IGF-1/IGF-1R in regulation of invasion in DU145 prostate cancer cells

    Directory of Open Access Journals (Sweden)

    Setya Hemani

    2008-07-01

    Full Text Available Abstract Background Prostate cancer progression to androgen independence is the primary cause of mortality by this tumor type. The IGF-1/IGF-1R axis is well known to contribute to prostate cancer initiation, but its contribution to invasiveness and the downstream signalling mechanisms that are involved are unclear at present. Results We examined the invasive response of androgen independent DU145 prostate carcinoma cells to IGF-1 stimulation using Matrigel assays. We then examined the signaling mechanisms and protease activities that are associated with this response. IGF-1 significantly increased the invasive capacity of DU145 cells in vitro, and this increase was inhibited by blocking IGF-1R. We further demonstrated that specific inhibitors of the MAPK and PI3-K pathways decrease IGF-1-mediated invasion. To determine potential molecular mechanisms for this change in invasive capacity, we examined changes in expression and activity of matrix metalloproteinases. We observed that IGF-1 increases the enzymatic activity of MMP-2 and MMP-9 in DU145 cells. These changes in activity are due to differences in expression in the case of MMP-9 but not in the case of MMP-2. This observation is corroborated by the fact that correlated changes of expression in a regulator of MMP-2, TIMP-2, were also seen. Conclusion This work identifies a specific effect of IGF-1 on the invasive capacity of DU145 prostate cancer cells, and furthermore delineates mechanisms that contribute to this effect.

  15. Increased expression of insulin-like growth factor-1 receptor is correlated with worse survival in canine appendicular osteosarcoma.

    Science.gov (United States)

    Maniscalco, Lorella; Iussich, Selina; Morello, Emanuela; Martano, Marina; Gattino, Francesca; Miretti, Silvia; Biolatti, Bartolomeo; Accornero, Paolo; Martignani, Eugenio; Sánchez-Céspedes, Raquel; Buracco, Paolo; De Maria, Raffaella

    2015-08-01

    Insulin-like growth factor 1 receptor (IGF-1R) is a cell membrane receptor widely expressed in tissues and involved in different cancers in humans. IGF-1R expression in human osteosarcoma has been associated with the development of tumour metastasis and with prognosis, and represents an attractive therapeutic target. The goal of this study was to investigate the expression of IGF-1R in canine osteosarcoma tissues and cell lines and assess its role and prognostic value. Samples from 34 dogs were examined by immunohistochemistry for IGF-1R expression. IGF-1R/AKT/MAPK signalling was evaluated by western blot and quantitative polymerase chain reaction in the cell lines. In addition, the in vitro inhibition of IGF-1R with pycropodophillin (PPP) was used to evaluate molecular and biological effects. Immunohistochemical data showed that IGF-1R was expressed in 71% of the analysed osteosarcoma samples and that dogs with higher levels of IGF-IR expression (47% of cases) had decreased survival (P canine osteosarcoma IGF-IR is activated by IGF-1 mostly in a paracrine or endocrine (rather than autocrine) manner, leading to activation of AKT/MAPK signalling. PPP caused p-IGF-1R dephosphorylation with partial blocking of p-MAPK and p-AKT, as well as apoptosis. It was concluded that IGF-1R is expressed and plays a role in canine osteosarcoma and that its expression is correlated with a poor prognosis. As in humans, IGF-1R may represent a good therapeutic target and a prognostic factor for canine osteosarcoma. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. Tumor-targeted Nanobullets: Anti-EGFR nanobody-liposomes loaded with anti-IGF-1R kinase inhibitor for cancer treatment.

    Science.gov (United States)

    van der Meel, Roy; Oliveira, Sabrina; Altintas, Isil; Haselberg, Rob; van der Veeken, Joris; Roovers, Rob C; van Bergen en Henegouwen, Paul M P; Storm, Gert; Hennink, Wim E; Schiffelers, Raymond M; Kok, Robbert J

    2012-04-30

    The epidermal growth factor receptor (EGFR) is a validated target for anti-cancer therapy and several EGFR inhibitors are used in the clinic. Over the years, an increasing number of studies have reported on the crosstalk between EGFR and other receptors that can contribute to accelerated cancer development or even acquisition of resistance to anti-EGFR therapies. Combined targeting of EGFR and insulin-like growth factor 1 receptor (IGF-1R) is a rational strategy to potentiate anti-cancer treatment and possibly retard resistance development. In the present study, we have pursued this by encapsulating the kinase inhibitor AG538 in anti-EGFR nanobody-liposomes. The thus developed dual-active nanobody-liposomes associated with EGFR-(over)expressing cells in an EGFR-specific manner and blocked both EGFR and IGF-1R activation, due to the presence of the EGFR-blocking nanobody EGa1 and the anti-IGF-1R kinase inhibitor AG538 respectively. AG538-loaded nanobody-liposomes induced a strong inhibition of tumor cell proliferation even upon short-term exposure followed by a drug-free wash-out period. Therefore, AG538-loaded nanobody-liposomes are a promising anti-cancer formulation due to efficient intracellular delivery of AG538 in combination with antagonistic and downregulating properties of the EGa1 nanobody-liposomes. Copyright © 2011 Elsevier B.V. All rights reserved.

  17. Oncogenic fusion proteins adopt the insulin-like growth factor signaling pathway.

    Science.gov (United States)

    Werner, Haim; Meisel-Sharon, Shilhav; Bruchim, Ilan

    2018-02-19

    The insulin-like growth factor-1 receptor (IGF1R) has been identified as a potent anti-apoptotic, pro-survival tyrosine kinase-containing receptor. Overexpression of the IGF1R gene constitutes a typical feature of most human cancers. Consistent with these biological roles, cells expressing high levels of IGF1R are expected not to die, a quintessential feature of cancer cells. Tumor specific chromosomal translocations that disrupt the architecture of transcription factors are a common theme in carcinogenesis. Increasing evidence gathered over the past fifteen years demonstrate that this type of genomic rearrangements is common not only among pediatric and hematological malignancies, as classically thought, but may also provide a molecular and cytogenetic foundation for an ever-increasing portion of adult epithelial tumors. In this review article we provide evidence that the mechanism of action of oncogenic fusion proteins associated with both pediatric and adult malignancies involves transactivation of the IGF1R gene, with ensuing increases in IGF1R levels and ligand-mediated receptor phosphorylation. Disrupted transcription factors adopt the IGF1R signaling pathway and elicit their oncogenic activities via activation of this critical regulatory network. Combined targeting of oncogenic fusion proteins along with the IGF1R may constitute a promising therapeutic approach.

  18. IGF-1R Promotes Symmetric Self-Renewal and Migration of Alkaline Phosphatase+ Germ Stem Cells through HIF-2α-OCT4/CXCR4 Loop under Hypoxia.

    Science.gov (United States)

    Kuo, Yung-Che; Au, Heng-Kien; Hsu, Jue-Liang; Wang, Hsiao-Feng; Lee, Chiung-Ju; Peng, Syue-Wei; Lai, Ssu-Chuan; Wu, Yu-Chih; Ho, Hong-Nerng; Huang, Yen-Hua

    2018-02-13

    Hypoxia cooperates with endocrine signaling to maintain the symmetric self-renewal proliferation and migration of embryonic germline stem cells (GSCs). However, the lack of an appropriate in vitro cell model has dramatically hindered the understanding of the mechanism underlying this cooperation. Here, using a serum-free system, we demonstrated that hypoxia significantly induced the GSC mesenchymal transition, increased the expression levels of the pluripotent transcription factor OCT4 and migration-associated proteins (SDF-1, CXCR4, IGF-1, and IGF-1R), and activated the cellular expression and translocalization of the CXCR4-downstream proteins ARP3/pFAK. The underlying mechanism involved significant IGF-1/IGF-1R activation of OCT4/CXCR4 expression through HIF-2α regulation. Picropodophyllin-induced inhibition of IGF-1R phosphorylation significantly suppressed hypoxia-induced SDF-1/CXCR4 expression and cell migration. Furthermore, transactivation between IGF-1R and CXCR4 was involved. In summary, we demonstrated that niche hypoxia synergistically cooperates with its associated IGF-1R signaling to regulate the symmetric division (self-renewal proliferation) and cell migration of alkaline phosphatase-positive GSCs through HIF-2α-OCT4/CXCR4 during embryogenesis. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

  19. miR-598 acts as a tumor suppressor in human gastric cancer by targeting IGF-1R.

    Science.gov (United States)

    Liu, Na; Yang, Hua; Wang, Hong

    2018-01-01

    In recent years, the aberrant expression of miR-598 in tumorigenesis has been demonstrated, as well as the fact that the IGF-1R pathway is also involved in the development of human gastric cancer (GC). The present study aimed to investigate the molecular mechanisms underlying miR-598-regulated IGF-1R expression in human GC. We analyzed the expression of miR-598 and IGF-1R in GC samples and cells, and evaluated the clinical significance of miR-598 and IGF-1R in GC patients. Furthermore, in vitro and in vivo assays were used to investigate the molecular mechanisms of miR-598 and IGF-1R. miR-598 expression was frequently downregulated in GC tissues and cells, and significantly correlated with poor prognosis, vascular invasion, TNM stage, and lymph node metastases as well as IGF-1R expression. The overexpression of miR-598 obviously inhibited cell proliferation, migration, invasion, and induced cell cycle arrest in the G1/S phase, and increased the apoptosis of GC cells. The overexpression of miR-598 also significantly inhibited ERK1/2 and Akt phosphorylation level. In vivo assay validated the inhibitory effect of miR-598 on tumor growth. Further studies showed that miR-598 inhibited IGF-1R protein expression by directly targeting its 3'-UTR. Besides, over-expression of IGF-1R reversed the inhibitory effects of miR-598, while suppression of IGF-1R expression showed inverse effects. miR-598 suppresses GC cell proliferation, migration and invasion by directly targeting IGF-1R expression. Thus, miR-598 may be a useful target for GC patients.

  20. Insulin-like growth factor-1 signaling in renal cell carcinoma

    International Nuclear Information System (INIS)

    Tracz, Adam F.; Szczylik, Cezary; Porta, Camillo; Czarnecka, Anna M.

    2016-01-01

    Renal cell carcinoma (RCC) incidence is highest in highly developed countries and it is the seventh most common neoplasm diagnosed. RCC management include nephrectomy and targeted therapies. Type 1 insulin-like growth factor (IGF-1) pathway plays an important role in cell proliferation and apoptosis resistance. IGF-1 and insulin share overlapping downstream signaling pathways in normal and cancer cells. IGF-1 receptor (IGF1R) stimulation may promote malignant transformation promoting cell proliferation, dedifferentiation and inhibiting apoptosis. Clear cell renal cell carcinoma (ccRCC) patients with IGF1R overexpression have 70 % increased risk of death compared to patients who had tumors without IGF1R expression. IGF1R signaling deregulation may results in p53, WT, BRCA1, VHL loss of function. RCC cells with high expression of IGF1R are more resistant to chemotherapy than cells with low expression. Silencing of IGF1R increase the chemosensitivity of ccRCC cells and the effect is greater in VHL mutated cells. Understanding the role of IGF-1 signaling pathway in RCC may result in development of new targeted therapeutic interventions. First preclinical attempts with anti-IGF-1R monoclonal antibodies or fragment antigen-binding (Fab) fragments alone or in combination with an mTOR inhibitor were shown to inhibit in vitro growth and reduced the number of colonies formed by of RCC cells

  1. Does Metformin affect ER, PR, IGF-1R, β-catenin and PAX-2 expression in women with diabetes mellitus and endometrial cancer?

    Science.gov (United States)

    Markowska, Anna; Pawałowska, Monika; Filas, Violetta; Korski, Konstanty; Gryboś, Marian; Sajdak, Stefan; Olejek, Anita; Bednarek, Wiesława; Spiewankiewicz, Beata; Lubin, Jolanta; Markowska, Janina

    2013-12-05

    Diabetes mellitus, as a risk factor for endometrial cancer (EC), causes an increase in insulin and IGF-1 concentrations in the blood serum. The increase in insulin and IGF-1 are considered mitogenic factors contributory to cancer development. Studies suggest that metformin has preventive activity, decreasing mortality and the risk of neoplasms. Since estrogen (ER), progesterone (PR) and IGF-1 (IGF-1R) receptor expression and β-catenin and PAX-2 mutations are significant in the development of endometrial cancer, it was decided to study these factors in patients with endometrial cancer and type 2 diabetes mellitus (DM2), and to establish the effects of metformin on their expression. The expression of ER, PR, IGF-1R, β-catenin and PAX-2 have been immunohistochemically investigated in 86 type I endometrial cancer specimens. Patients were grouped according to the presence of DM2 and the type of hypoglycemic treatment administered. Comparing EC patients with DM2 and normal glycemic status, we found increased IGF-1R expression in women with DM2. A decrease in ER expression was noted in women with EC and DM2 receiving metformin as compared to women treated with insulin (p = 0.004). There was no statistically significant difference in PR, IGF-1R, β-catenin and PAX-2 expression among women receiving metformin and other hypoglycemic treatment. Although epidemiological studies suggest the beneficial role of metformin in many human cancers, there are still few studies confirming its favorable effect on endometrial cancer. Decreased ER expression in patients receiving metformin needs further research to allow evaluation of its clinical significance.

  2. MVP expression is related to IGF1-R in cervical carcinoma patients treated by radiochemotherapy.

    Science.gov (United States)

    Lloret, Marta; Lara, Pedro Carlos; Bordón, Elisa; Rey, Agustin; Falcón, Orlando; Apolinario, Rosa Maria; Clavo, Bernardino; Ruiz, Ana

    2008-09-01

    To assess the expression of MVP in cervix carcinoma patients treated by radiochemotherapy, its relation to clinical and pathologic prognostic factors and its role in predicting clinical outcome. In addition the relation to IGF-1R expression in this cohort of patients will be explored. Sixty consecutive patients suffering from localized cervix carcinoma were prospectively included in this study from July 1999 to December 2003. Follow-up was closed in November 2007. Patients were staged following the TNM classification. All patients received pelvic radiation (45-64.80 Gy in 1.8-2 Gy fractions) followed brachytherapy and concomitant cisplatin at 40 mg/m(2)/week doses. MVP expression was studied by immunohistochemistry in paraffin-embedded tumour tissue. MVP was expressed in 58 patients (96.7%) and no relation was found with clinicopathological variables. High MVP expression was related to high IGF1-R expression (p=0.023). Complete response after treatment was observed in 50 patients (83.3%). Clinical stage of the disease and clinical response to radiochemotherapy were the most important prognostic factors related to survival. High MVP and IGF-1R tumour expression was strongly related to poor local and regional disease-free survival (p=0.006), distant disease-free survival (p=0.050), disease-free survival (p=0.006), and cause-specific survival (p=0.007) in patients achieving a complete response. MVP and IGF-1R expression were related in clinical cervical tumours and confer reduced long-term local control in patients who achieved clinical complete response to radiochemotherapy.

  3. Impact of IGF-1, IGF-1R, and IGFBP-3 promoter methylation on the risk and prognosis of esophageal carcinoma.

    Science.gov (United States)

    Ye, Peng; Qu, Chang-Fa; Hu, Xue-Lin

    2016-05-01

    The aim of this study is to investigate IGF-1, IGF-1R, and IGFBP-3 methylations in esophageal carcinoma (EC) patients and their relationship with the development and prognosis of EC. This study population consisted of 264 patients (case group) whom EC radical resection was performed and 283 healthy individuals (control group). Methylation-specific PCR (MSP) detected the methylation status of IGF-1, IGF-1R, and IGFBP-3 in the peripheral blood in both groups. The expressions of IGF-1, IGF-1R, and IGFBP-3 in EC and adjacent normal tissues were detected by immunohistochemistry (IHC). The methylation rates of IGF-1, IGF-1R, IGFBP3, and IGF-1 + IGF1R + IGFBP3 in the case group were higher than those in the control group (all P IGF-1, IGF-1R, IGFBP3, and IGF-1 + IGF1R + IGFBP3 IGF-1 among patients of different clinicopathological features (all P IGF-1 and IGF-1R in EC were significantly higher than those in adjacent normal tissues (both P IGF-1 and IGF1R gene promoter methylation was positively correlated with the positive expressions of IGF-1 (r = 0.139, P = 0.024) and IGF-1R (r = 0.135, P = 0.028), while the IGFBP3 methylation was negatively correlated with the positive expression of IGFBP3 (r = -0.133, P = 0.031). The positive expressions of IGF-1, IGF-1R, and IGFBP-3 were related to different clinicopathological features (all P IGF-1, IGF-1R, and IGF-1 + IGF1R + IGFBP3 ; expressions of IGF-1 and IGF-1R protein; infiltration depth; and lymph node metastasis (LNM) were independent factors of EC prognosis. Our study demonstrated that methylation of IGF-1, IGF1R, IGFBP3, and IGF-1 + IGF1R + IGFBP3 was closely linked with the occurrence of EC and patients' clinicopathological features. Besides, the methylation status of the target genes and the expressions of IGF-1 and IGF-1R protein were independent factors of EC prognosis, which could provide a direction for the prognosis and treatment of EC.

  4. Doxorubicin plus the IGF-1R antibody cixutumumab in soft tissue sarcoma: a phase I study using the TITE-CRM model.

    Science.gov (United States)

    Chugh, R; Griffith, K A; Davis, E J; Thomas, D G; Zavala, J D; Metko, G; Brockstein, B; Undevia, S D; Stadler, W M; Schuetze, S M

    2015-07-01

    Insulin-like growth factor receptor (IGF-1R) has been studied as an oncologic target in soft tissue sarcoma (STS), but its role in sarcoma biology is unclear. Anti-IGF-1R antibody cixutumumab demonstrated acceptable toxicity but limited activity as a single agent in STS. We carried out a dose-escalation study of cixutumumab with doxorubicin to evaluate safety and dosing of the combination. Eligible patients with advanced STS were treated with cixutumumab intravenously on days 1/8/15 at one of three dose levels (A: 1 mg/kg, B: 3 mg/kg, C: 6 mg/kg) with doxorubicin at 75 mg/m(2) as a 48 h infusion on day 1 of a 21 day cycle. After six cycles of the combination, patients could receive cixutumumab alone. The Time-to-Event Continual Reassessment Method was used to estimate the probability of dose-limiting toxicity (DLT) and to assign patients to the dose with an estimated probability of DLT≤20%. Between September 2008 and January 2012, 30 patients with advanced STS received a median of six cycles of therapy (range <1-22). Two DLTs were observed, grade 3 mucositis (dose level B) and grade 4 hyperglycemia (dose level C). Grade 2 and 3 reduced left ventricular ejection fraction was seen in three and two patients, respectively. Five partial responses were observed, and estimated progression-free survival was 5.3 months (95% confidence interval 3.0-6.3) in 26 response-assessable patients. Immunohistochemical staining of 11 available tumor samples for IGF-1R and phospho-IGF-1R was not significantly different among responders and non-responders, and serum analysis of select single-nucleotide polymorphisms did not predict for cardiotoxicity. The maximum tolerated dose was doxorubicin 75 mg/m(2) on day 1 and cixitumumab 6 mg/kg on days 1/8/15 of a 21 day cycle. Cardiac toxicity was observed and should be monitored in subsequent studies, which should be considered in STS only if a predictive biomarker of benefit to anti-IGF-1R therapy is identified. Clinical

  5. 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.

  6. Simvastatin inhibits the proliferation of human prostate cancer PC-3 cells via down-regulation of the insulin-like growth factor 1 receptor

    International Nuclear Information System (INIS)

    Sekine, Yoshitaka; Furuya, Yosuke; Nishii, Masahiro; Koike, Hidekazu; Matsui, Hiroshi; Suzuki, Kazuhiro

    2008-01-01

    Recently, statins have been being studied for their proapoptic and antimetastatic effects. However, the exact mechanisms of their anticancer action are still unclear. Dolichyl phosphate is a nonsterol isoprenoid derivative in the mevalonate pathway that affects the expression of the Insulin-like growth factor 1 receptor (IGF-1R). IGF-1R activation is required for prostate cell proliferation; therefore, IGF-1R inhibitory agents may be of preventive and/or therapeutic value. In this study, the effects of simvastatin on IGF-1R signaling in prostate cancer PC-3 cells were examined. Simvastatin suppressed proliferation and induced apoptosis of PC-3, and the expression of IGF-1R was suppressed by simvastatin. Knockdown of IGF-1R by siRNA led to inhibition of proliferation of PC-3. Simvastatin also inhibited IGF-1-induced activation of both ERK and Akt signaling and IGF-1-induced PC-3 cell proliferation. Our results suggest statins are potent inhibitors of the IGF-1/IGF-1R system in prostate cancer cells and may be beneficial in prostate cancer treatment

  7. Serial analysis of resected prostate cancer suggests up-regulation of type 1 IGF receptor with disease progression.

    Science.gov (United States)

    Turney, Benjamin W; Turner, Gareth D H; Brewster, Simon F; Macaulay, Valentine M

    2011-05-01

    • To compare immunostaining protocols using different antibodies for the type 1 insulin-like growth factor receptor (IGF-1R) in channel transurethal resection of the prostate (chTURP) chips, and to investigate how IGF-1R expression varies with time in serial prostate cancer specimens from individual patients. • We studied IGF-1R expression in 44 prostate cancer specimens from 18 patients who had undergone serial chTURP at least 3 months apart. • Retrospective analysis of the hospital notes was undertaken to obtain clinical information, including age, Gleason score, prostate-specific antigen (PSA) level, hormone treatment and metastatic disease status at the time of each operation. • After an optimization process using three commercially-available IGF-1R antibodies, we used two antibodies for semiquantititve immunostaining of serial chTURP chips. • Santa Cruz antibody sc713 gave positive staining in IGF-1R null R- cells, and was not used further. Antibodies from Cell Signaling Technology (Beverly, MA, USA) (CS) and NeoMarkers Inc. (Fremont, CA, USA) (NM) did not stain R- cells and, in prostate tissue, showed staining of the glandular epithelium, with negligible stromal staining. All 44 chTURP samples contained identifiable malignant tissue and, of these, 73% and 64% scored moderately or strongly (score 3 or 4) with the CS and NM antibodies respectively. • There was significant correlation of IGF-1R scores of malignant tissue between the two antibodies (P < 0.001). By contrast, staining of benign glands showed poor correlation between antibodies: CS gave significantly weaker staining than malignant epithelium in the same sections (P < 0.001), whereas NM showed poor discrimination between malignant and benign glands. IGF-1R staining scores generated by the CS antibody were used to analyze the clinical data. • Most patients (six of seven) with falling IGF-1R staining scores were responding to androgen deprivation therapy (confirmed by PSA response

  8. Anticancer effect of genistein on BG-1 ovarian cancer growth induced by 17 β-estradiol or bisphenol A via the suppression of the crosstalk between estrogen receptor alpha and insulin-like growth factor-1 receptor signaling pathways

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Kyung-A; Park, Min-Ah; Kang, Nam-Hee; Yi, Bo-Rim; Hyun, Sang-Hwan; Jeung, Eui-Bae; Choi, Kyung-Chul, E-mail: kchoi@cbu.ac.kr

    2013-11-01

    The interaction between estrogen receptor (ER) and insulin-like growth factor-1 receptor (IGF-1R) signaling pathway plays an important role in proliferation of and resistance to endocrine therapy to estrogen dependent cancers. Estrogen (E2) upregulates the expression of components of IGF-1 system and induces the downstream of mitogenic signaling cascades via phosphorylation of insulin receptor substrate-1 (IRS-1). In the present study, we evaluated the xenoestrogenic effect of bisphenol A (BPA) and antiproliferative activity of genistein (GEN) in accordance with the influence on this crosstalk. BPA was determined to affect this crosstalk by upregulating mRNA expressions of ERα and IGF-1R and inducing phosphorylation of IRS-1 and Akt in protein level in BG-1 ovarian cancer cells as E2 did. In the mouse model xenografted with BG-1 cells, BPA significantly increased a tumor burden of mice and expressions of ERα, pIRS-1, and cyclin D1 in tumor mass compared to vehicle, indicating that BPA induces ovarian cancer growth by promoting the crosstalk between ER and IGF-1R signals. On the other hand, GEN effectively reversed estrogenicity of BPA by reversing mRNA and protein expressions of ERα, IGF-1R, pIRS-1, and pAkt induced by BPA in cellular model and also significantly decreased tumor growth and in vivo expressions of ERα, pIRS-1, and pAkt in xenografted mouse model. Also, GEN was confirmed to have an antiproliferative effect by inducing apoptotic signaling cascades. Taken together, these results suggest that GEN effectively reversed the increased proliferation of BG-1 ovarian cancer by suppressing the crosstalk between ERα and IGF-1R signaling pathways upregulated by BPA or E2.

  9. Anticancer effect of genistein on BG-1 ovarian cancer growth induced by 17 β-estradiol or bisphenol A via the suppression of the crosstalk between estrogen receptor alpha and insulin-like growth factor-1 receptor signaling pathways

    International Nuclear Information System (INIS)

    Hwang, Kyung-A; Park, Min-Ah; Kang, Nam-Hee; Yi, Bo-Rim; Hyun, Sang-Hwan; Jeung, Eui-Bae; Choi, Kyung-Chul

    2013-01-01

    The interaction between estrogen receptor (ER) and insulin-like growth factor-1 receptor (IGF-1R) signaling pathway plays an important role in proliferation of and resistance to endocrine therapy to estrogen dependent cancers. Estrogen (E2) upregulates the expression of components of IGF-1 system and induces the downstream of mitogenic signaling cascades via phosphorylation of insulin receptor substrate-1 (IRS-1). In the present study, we evaluated the xenoestrogenic effect of bisphenol A (BPA) and antiproliferative activity of genistein (GEN) in accordance with the influence on this crosstalk. BPA was determined to affect this crosstalk by upregulating mRNA expressions of ERα and IGF-1R and inducing phosphorylation of IRS-1 and Akt in protein level in BG-1 ovarian cancer cells as E2 did. In the mouse model xenografted with BG-1 cells, BPA significantly increased a tumor burden of mice and expressions of ERα, pIRS-1, and cyclin D1 in tumor mass compared to vehicle, indicating that BPA induces ovarian cancer growth by promoting the crosstalk between ER and IGF-1R signals. On the other hand, GEN effectively reversed estrogenicity of BPA by reversing mRNA and protein expressions of ERα, IGF-1R, pIRS-1, and pAkt induced by BPA in cellular model and also significantly decreased tumor growth and in vivo expressions of ERα, pIRS-1, and pAkt in xenografted mouse model. Also, GEN was confirmed to have an antiproliferative effect by inducing apoptotic signaling cascades. Taken together, these results suggest that GEN effectively reversed the increased proliferation of BG-1 ovarian cancer by suppressing the crosstalk between ERα and IGF-1R signaling pathways upregulated by BPA or E2

  10. Growth inhibition of human pancreatic cancer cells by lipofection mediated IGF-1R antisense oligodeoxynucletides in combination with ionizing radiation

    International Nuclear Information System (INIS)

    Pan Yaozhen; Sun Chengyi; Wang Yuzhi

    2004-01-01

    Objective: To study the growth inhibition of human pancreatic cancer cells (PC-3) by lipofection-mediated and ionizing radiation improving transfection of IGF-1R antisense oligodeoxynucletides (ASON) in vitro. Methods: Colonigenicity of PC-3 cells in vitro after 60 Co γ-radiation was observed for ascertaining their radiosensitivity and optimal radiation dose was selected according to the radiation sensitivity. PC-3 cells were transfected by two ways: 1) by lipofection-mediated IGF-1R ASON combined with ionizing radiation. 2) by lipo-ASON alone without ionizing radiation. Cell growth was assessed by MTT method. The expression of IGF-1R at mRNA level was examined by RT-PCR. Flow cytometry was used to demonstrate apoptotic changes in lipo-ASON-treated cells. Results: The inhibitory efficiency of lipo-ASON combined with ionizing radiation was higher than that without ionizing radiation (P < 0.05). The apoptotic efficiency and the decreased level of IGF-1R at mRNA were significantly improved (P < 0.05). Conclusion: Lipofection-mediated and ionizing radiation-promoted transfection of IGF-1R antisense oligodeoxynucletides (ASON) significantly decreases IGF-1R at mRNA level and induces apoptosis of human pancreatic cancer cells in vitro

  11. Insulin/insulin like growth factors in cancer: new roles for the aryl hydrocarbon receptor, tumor resistance mechanisms and new blocking strategies

    Directory of Open Access Journals (Sweden)

    Travis B Salisbury

    2015-02-01

    Full Text Available The insulin-like growth factor 1 receptor (IGF1R and the insulin receptor (IR are receptor tyrosine kinases (RTKs that are expressed in cancer cells. The results of different studies indicate that tumor proliferation and survival is dependent on the IGF1R and IR, and that their inhibition leads to reductions in proliferation and increases in cell death. Molecular targeting therapies that have been used in solid tumors include: anti-IGF1R antibodies, anti-IGF1/IGF2 antibodies and small molecule inhibitors that suppress IGF1R and IR kinase activity. New advances in the molecular basis of anti-IGF1R blocking antibodies reveal they are biased agonists and promote the binding of IGF1 to integrin β3 receptors in some cancer cells. Our recent reports indicate that pharmacological aryl hydrocarbon receptor (AHR ligands inhibit breast cancer cell responses to IGFs, suggesting that targeting AHR may have benefit in cancers whose proliferation and survival are dependent on insulin/IGF signaling. Novel aspects of IGF1R/IR in cancer, such as biased agonism, integrin β3 signaling, AHR and new therapeutic targeting strategies will be discussed.

  12. Role of the Insulin-Like Growth Factor Type 1 Receptor in the Pathogenesis of Diabetic Encephalopathy

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    Duo Zhang

    2015-01-01

    Full Text Available Defective cognitive function is common in patients with diabetes, suggesting that insulin normally exerts anabolic actions in neuron, namely, diabetic encephalopathy. However, because insulin can cross-activate the insulin-like growth factor type 1 receptor (IGF-1R, which also functions in most of tissues, such as muscle and bone, it has been difficult to establish the direct (IGF-1-independent actions of insulin in the pathogenesis of diabetic encephalopathy. To overcome this problem, we examined insulin signaling and action in primary PC-12 cells engineered for conditional disruption of the IGF-1 receptorIGF-1R. The results showed that the lower glucose metabolism and high expression of IGF-1R occurred in the brain of the DE rat model. The results also showed the defect of IGF-1R could significantly improve the ability of glucose consumption and enhance sensitivity to insulin-induced IR and Akt phosphorylation in PC12 cells. And meanwhile, IGF-1R allele gene knockout (IGF-1Rneo mice treated with HFD/STZ had better cognitive abilities than those of wild mice. Those results indicate that insulin exerts direct anabolic actions in neuron-like cells by activation of its cognate receptor and prove that IGF-1R plays an important role in the pathogenesis of diabetic encephalopathy.

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

    International Nuclear Information System (INIS)

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

    2005-01-01

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

  14. Targeting Insulin-Like Growth Factor 1 Receptor Inhibits Pancreatic Cancer Growth and Metastasis

    Science.gov (United States)

    Subramani, Ramadevi; Lopez-Valdez, Rebecca; Arumugam, Arunkumar; Nandy, Sushmita; Boopalan, Thiyagarajan; Lakshmanaswamy, Rajkumar

    2014-01-01

    Pancreatic cancer is one of the most lethal cancers. Increasing incidence and mortality indicates that there is still much lacking in detection and management of the disease. This is partly due to a lack of specific symptoms during early stages of the disease. Several growth factor receptors have been associated with pancreatic cancer. Here, we have investigated if an RNA interference approach targeted to IGF-IR could be effective and efficient against pancreatic cancer growth and metastasis. For that, we evaluated the effects of IGF-1R inhibition using small interfering RNA (siRNAs) on tumor growth and metastasis in HPAC and PANC-1 pancreatic cancer cell lines. We found that silencing IGF-1R inhibits pancreatic cancer growth and metastasis by blocking key signaling pathways such AKT/PI3K, MAPK, JAK/STAT and EMT. Silencing IGF-1R resulted in an anti-proliferative effect in PANC-1 and HPAC pancreatic cancer cell lines. Matrigel invasion, transwell migration and wound healing assays also revealed a role for IGF-1R in metastatic properties of pancreatic cancer. These results were further confirmed using Western blotting analysis of key intermediates involved in proliferation, epithelial mesenchymal transition, migration, and invasion. In addition, soft agar assays showed that silencing IGF-1R also blocks the colony forming capabilities of pancreatic cancer cells in vitro. Western blots, as well as, flow cytometric analysis revealed the induction of apoptosis in IGF-1R silenced cells. Interestingly, silencing IGF-1R also suppressed the expression of insulin receptor β. All these effects together significantly control pancreatic cancer cell growth and metastasis. To conclude, our results demonstrate the significance of IGF-1R in pancreatic cancer. PMID:24809702

  15. Insulin-like growth factor-1 receptor in mature osteoblasts is required for periosteal bone formation induced by reloading

    Science.gov (United States)

    Kubota, Takuo; Elalieh, Hashem Z.; Saless, Neema; Fong, Chak; Wang, Yongmei; Babey, Muriel; Cheng, Zhiqiang; Bikle, Daniel D.

    2013-11-01

    Skeletal loading and unloading has a pronounced impact on bone remodeling, a process also regulated by insulin-like growth factor-1 (IGF-1) signaling. Skeletal unloading leads to resistance to the anabolic effect of IGF-1, while reloading after unloading restores responsiveness to IGF-1. However, a direct study of the importance of IGF-1 signaling in the skeletal response to mechanical loading remains to be tested. In this study, we assessed the skeletal response of osteoblast-specific Igf-1 receptor deficient (Igf-1r-/-) mice to unloading and reloading. The mice were hindlimb unloaded for 14 days and then reloaded for 16 days. Igf-1r-/- mice displayed smaller cortical bone and diminished periosteal and endosteal bone formation at baseline. Periosteal and endosteal bone formation decreased with unloading in Igf-1r+/+ mice. However, the recovery of periosteal bone formation with reloading was completely inhibited in Igf-1r-/- mice, although reloading-induced endosteal bone formation was not hampered. These changes in bone formation resulted in the abolishment of the expected increase in total cross-sectional area with reloading in Igf-1r-/- mice compared to the control mice. These results suggest that the Igf-1r in mature osteoblasts has a critical role in periosteal bone formation in the skeletal response to mechanical loading.

  16. IGF-1R tyrosine kinase inhibitors and Vitamin K1 enhance the antitumor effects of Regorafenib in HCC cell lines.

    Science.gov (United States)

    Refolo, Maria Grazia; D'Alessandro, Rosalba; Lippolis, Catia; Carella, Nicola; Cavallini, Aldo; Messa, Caterina; Carr, Brian Irving

    2017-11-28

    The recent RESORCE trial showed that treatment with Regorafenib after Sorafenib failure provided a significant improvement in overall survival in HCC patients. Preclinical and clinical trial data showed that Regorafenib is a more potent drug than Sorafenib. In this study we aimed at improving Regorafenib actions and at reducing its toxicity, by targeting parallel pathways or by combination with Vitamins K (VKs). We investigated the effects of Regorafenib administrated at low concentrations and in combination with either VK1 and/or with GSK1838705A or OSI-906, two IGF1-R inhibitors, on HCC cell growth and motility. Our results showed that both IGF1-R inhibitors potentiated the antiproliferative and pro-apoptotic effects of Regorafenib and/or VK1 in HCC cell lines. Moreover we provide evidence that the combined treatment with IG1-R antagonists and Regorafenib (and/or VK1) also caused a significant reduction and depolymerization of actin resulting in synergistic inhibition exerted on cell migration. Thus, simultaneous blocking of MAPK and PI3K/Akt cascades with IGF1-R inhibitors plus Regorafenib could represent a more potent approach for HCC treatment.

  17. Safety, pharmacokinetics, and preliminary activity of the anti-IGF-1R antibody figitumumab (CP-751,871) in patients with sarcoma and Ewing's sarcoma: a phase 1 expansion cohort study.

    Science.gov (United States)

    Olmos, David; Postel-Vinay, Sophie; Molife, L Rhoda; Okuno, Scott H; Schuetze, Scott M; Paccagnella, M Luisa; Batzel, Gretchen N; Yin, Donghua; Pritchard-Jones, Kathryn; Judson, Ian; Worden, Francis P; Gualberto, Antonio; Scurr, Michelle; de Bono, Johann S; Haluska, Paul

    2010-02-01

    Figitumumab is a fully human IgG2 monoclonal antibody targeting the insulin-like growth-factor-1 receptor (IGF-1R). Preclinical data suggest a dependence on insulin-like growth-factor signalling for sarcoma subtypes, including Ewing's sarcoma, and early reports show antitumour activity of IGF-1R-targeting drugs in these diseases. Between January, 2006, and August, 2008, patients with refractory, advanced sarcomas received figitumumab (20 mg/kg) in two single-stage expansion cohorts within a solid-tumour phase 1 trial. The first cohort (n=15) included patients with multiple sarcoma subtypes, age 18 years or older, and the second cohort (n=14) consisted of patients with refractory Ewing's sarcoma, age 9 years or older. The primary endpoint was to assess the safety and tolerability of figitumumab. Secondary endpoints included pharmacokinetic profiling and preliminary antitumour activity (best response by Response Evaluation Criteria in Solid Tumours [RECIST]) in evaluable patients who received at least one dose of medication. This study is registered with ClinicalTrials.gov, number NCT00474760. 29 patients, 16 of whom had Ewing's sarcoma, were enrolled and received a total of 177 cycles of treatment (median 2, mean 6.1, range 1-24). Grade 3 deep venous thrombosis, grade 3 back pain, and grade 3 vomiting were each noted once in individual patients; one patient had grade 3 increases in aspartate aminotransferase and gammaglutamyltransferase concentrations. This patient also had grade 4 increases in alanine aminotransferase concentrations. The only other grade 4 adverse event was raised concentrations of uric acid, noted in one patient. Pharmacokinetics were comparable between patients with sarcoma and those with other solid tumours. 28 patients were assessed for response; two patients, both with Ewing's sarcoma, had objective responses (one complete response and one partial response) and eight patients had disease stabilisation (six with Ewing's sarcoma, one with

  18. Combinational Therapy Enhances the Effects of Anti-IGF-1R mAb Figitumumab to Target Small Cell Lung Cancer.

    Directory of Open Access Journals (Sweden)

    Hongxin Cao

    Full Text Available Small cell lung cancer (SCLC is a recalcitrant malignancy with distinct biologic properties. Antibody targeting therapy has been actively investigated as a new drug modality.We tested the expression of IGF-1R and calculated the survival in 61 SCLC patients. We also evaluated the anti-tumor effects of anti-IGF-1R monoclonal antibody Figitumumab (CP on SCLC, and tried two drug combinations to improve CP therapy.Our clinical data suggested that high IGF-1R expression was correlated with low SCLC patient survival. We then demonstrated the effect of CP was likely through IGF-1R blockage and down-regulation without IGF-1R auto-phosphorylation and PI3K/AKT activation. However, we observed elevated MEK/ERK activation upon CP treatment in SCLC cells, and this MEK/ERK activation was enhanced by ß-arrestin1 knockdown while attenuated by ß-arrestin2 knockdown. We found both MEK/ERK inhibitor and metformin could enhance CP treatment in SCLC cells. We further illustrated the additive effect of metformin was likely through promoting further IGF-1R down-regulation.Our results highlighted the potential of anti-IGF-1R therapy and the adjuvant therapy strategy with either MEK/ERK inhibitor or metformin to target SCLC, warranting further studies.

  19. The Regulatory Mechanism of MLT/MT1 Signaling on the Growth of Antler Mesenchymal Cells

    Directory of Open Access Journals (Sweden)

    Feifei Yang

    2017-10-01

    Full Text Available Melatonin (MLT plays an important role in regulating the physiological cycle of seasonal breeding animals. Melatonin receptor I (MT1 is effectively expressed in the cambium layer of deer antler. However, the function and metabolic mechanism of MLT/MT1 signaling in the mesenchymal cells of sika deer remain to be further elucidated. In this work, we detected the effects of MLT/MT1 signaling on mesenchymal cells proliferation and the interaction between MLT/MT1 and IGF1/IGF1-R signaling. The results show that (1 deer antler mesenchymal cells actually express MT1; (2 exogenous melatonin significantly promotes mesenchymal cells proliferation, while MT1 knock-down significantly impairs the positive effects of melatonin; and (3 melatonin significantly enhanced IGF1/IGF1-R signaling, as both the expression of IGF1 and IGF-1R increased, while MT1 knock-down significantly decreased IGF1-R expression and IGF1 synthesis. In summary, these data verified that MLT/MT1 signaling plays a crucial role in antler mesenchymal proliferation, which may be mediated by IGF1/IGF1-R.

  20. G protein-coupled receptors (GPCRs) That Signal via Protein Kinase A (PKA) Cross-talk at Insulin Receptor Substrate 1 (IRS1) to Activate the phosphatidylinositol 3-kinase (PI3K)/AKT Pathway.

    Science.gov (United States)

    Law, Nathan C; White, Morris F; Hunzicker-Dunn, Mary E

    2016-12-30

    G protein-coupled receptors (GPCRs) activate PI3K/v-AKT thymoma viral oncoprotein (AKT) to regulate many cellular functions that promote cell survival, proliferation, and growth. However, the mechanism by which GPCRs activate PI3K/AKT remains poorly understood. We used ovarian preantral granulosa cells (GCs) to elucidate the mechanism by which the GPCR agonist FSH via PKA activates the PI3K/AKT cascade. Insulin-like growth factor 1 (IGF1) is secreted in an autocrine/paracrine manner by GCs and activates the IGF1 receptor (IGF1R) but, in the absence of FSH, fails to stimulate YXXM phosphorylation of IRS1 (insulin receptor substrate 1) required for PI3K/AKT activation. We show that PKA directly phosphorylates the protein phosphatase 1 (PP1) regulatory subunit myosin phosphatase targeting subunit 1 (MYPT1) to activate PP1 associated with the IGF1R-IRS1 complex. Activated PP1 is sufficient to dephosphorylate at least four IRS1 Ser residues, Ser 318 , Ser 346 , Ser 612 , and Ser 789 , and promotes IRS1 YXXM phosphorylation by the IGF1R to activate the PI3K/AKT cascade. Additional experiments indicate that this mechanism also occurs in breast cancer, thyroid, and preovulatory granulosa cells, suggesting that the PKA-dependent dephosphorylation of IRS1 Ser/Thr residues is a conserved mechanism by which GPCRs signal to activate the PI3K/AKT pathway downstream of the IGF1R. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  1. IGF-1 Receptor Differentially Regulates Spontaneous and Evoked Transmission via Mitochondria at Hippocampal Synapses

    Science.gov (United States)

    Gazit, Neta; Vertkin, Irena; Shapira, Ilana; Helm, Martin; Slomowitz, Edden; Sheiba, Maayan; Mor, Yael; Rizzoli, Silvio; Slutsky, Inna

    2016-01-01

    Summary The insulin-like growth factor-1 receptor (IGF-1R) signaling is a key regulator of lifespan, growth, and development. While reduced IGF-1R signaling delays aging and Alzheimer’s disease progression, whether and how it regulates information processing at central synapses remains elusive. Here, we show that presynaptic IGF-1Rs are basally active, regulating synaptic vesicle release and short-term plasticity in excitatory hippocampal neurons. Acute IGF-1R blockade or transient knockdown suppresses spike-evoked synaptic transmission and presynaptic cytosolic Ca2+ transients, while promoting spontaneous transmission and resting Ca2+ level. This dual effect on transmitter release is mediated by mitochondria that attenuate Ca2+ buffering in the absence of spikes and decrease ATP production during spiking activity. We conclude that the mitochondria, activated by IGF-1R signaling, constitute a critical regulator of information processing in hippocampal neurons by maintaining evoked-to-spontaneous transmission ratio, while constraining synaptic facilitation at high frequencies. Excessive IGF-1R tone may contribute to hippocampal hyperactivity associated with Alzheimer’s disease. Video Abstract PMID:26804996

  2. 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

  3. Kinase inhibitors of the IGF-1R as a potential therapeutic agent for rheumatoid arthritis.

    Science.gov (United States)

    Tsushima, Hiroshi; Morimoto, Shinji; Fujishiro, Maki; Yoshida, Yuko; Hayakawa, Kunihiro; Hirai, Takuya; Miyashita, Tomoko; Ikeda, Keigo; Yamaji, Ken; Takamori, Kenji; Takasaki, Yoshinari; Sekigawa, Iwao; Tamura, Naoto

    2017-08-01

    We have previously shown that the inhibition of connective tissue growth factor (CTGF) is a potential therapeutic strategy against rheumatoid arthritis (RA). CTGF consists of four distinct modules, including the insulin-like growth factor binding protein (IGFBP). In serum, insulin-like growth factors (IGFs) bind IGFBPs, interact with the IGF-1 receptor (IGF-1 R), and regulate anabolic effects and bone metabolism. We investigated the correlation between IGF-1 and the pathogenesis of RA, and the inhibitory effect on osteoclastogenesis and angiogenesis of the small molecular weight kinase inhibitor of the IGF-1 R, NVP-AEW541, against pathogenesis of RA in vitro. Cell proliferation was evaluated by cell count and immunoblotting. The expression of IGF-1 and IGF-1 R was evaluated by RT-PCR. Osteoclastogenesis was evaluated using tartrate-resistant acid phosphatase staining, a bone resorption assay, and osteoclast-specific enzyme production. Angiogenesis was evaluated by a tube formation assay using human umbilical vein endothelial cells (HUVECs). The proliferation of MH7A cells was found to be inhibited in the presence of NVP-AEW541, and the phosphorylation of extracellular signal-regulated kinase (ERK) and Akt was downregulated in MH7A cells. IGF-1 and IGF-1 R mRNA expression levels were upregulated during formation of M-colony stimulating factor (M-CSF) and receptor activator of NF-κB ligand (RANKL)-mediated osteoclast formation. Moreover, osteoclastogenesis was suppressed in the presence of NVP-AEW541. The formation of the tubular network was enhanced by IGF-1, and this effect was neutralized by NVP-ARE541. Our findings suggest that NVP-AEW541 may be utilized as a potential therapeutic agent in the treatment of RA.

  4. Co-targeting the HER and IGF/insulin receptor axis in breast cancer, with triple targeting with endocrine therapy for hormone-sensitive disease.

    Science.gov (United States)

    Chakraborty, Ashok; Hatzis, Christos; DiGiovanna, Michael P

    2017-05-01

    Interactions between HER2, estrogen receptor (ER), and insulin-like growth factor I receptor (IGF1R) are implicated in resistance to monotherapies targeting these receptors. We have previously shown in pre-clinical studies synergistic anti-tumor effects for co-targeting each pairwise combination of HER2, IGF1R, and ER. Strikingly, synergy for HER2/IGF1R targeting occurred not only in a HER2+ model, but also in a HER2-normal model. The purpose of the current study was therefore to determine the generalizability of synergistic anti-tumor effects of co-targeting HER2/IGF1R, the anti-tumor activity of triple-targeting HER2/IGF1R/ER in hormone-dependent cell lines, and the effect of using the multi-targeting drugs neratinib (pan-HER) and BMS-754807 (dual IGF1R/insulin receptor). Proliferation and apoptosis assays were performed in a large panel of cell lines representing varying receptor expression levels. Mechanistic effects were studied using phospho-protein immunoblotting. Analyses of drug interaction effects were performed using linear mixed-effects regression models. Enhanced anti-proliferative effects of HER/IGF-insulin co-targeting were seen in most, though not all, cell lines, including HER2-normal lines. For ER+ lines, triple targeting with inclusion of anti-estrogen generally resulted in the greatest anti-tumor effects. Double or triple targeting generally resulted in marked increases in apoptosis in the sensitive lines. Mechanistic studies demonstrated that the synergy between drugs was correlated with maximal inhibition of Akt and ERK pathway signaling. Dual HER/IGF-insulin targeting, and triple targeting with inclusion of anti-estrogen drugs, shows striking anti-tumor activity across breast cancer types, and drugs with broader receptor specificity may be more effective than single receptor selective drugs, particularly for ER- cells.

  5. Gene Expression of IGF1, IGF1R, and IGFBP3 in Epiretinal Membranes of Patients with Proliferative Diabetic Retinopathy: Preliminary Study

    Directory of Open Access Journals (Sweden)

    Dorota Romaniuk

    2013-01-01

    Full Text Available The molecular mechanism formation of secondary epiretinal membranes (ERMs after proliferative diabetic retinopathy (PDR or primary idiopathic ERMs is still poorly understood. Therefore, the present study focused on the assessment of IGF1, IGF1R, and IGFBP3 mRNA levels in ERMs and PBMCs from patients with PDR. The examined group comprised 6 patients with secondary ERMs after PDR and the control group consisted of 11 patients with idiopathic ERMs. Quantification of IGF1, IGF1R, and IGFBP3 mRNAs was performed by real-time QRT-PCR technique. In ERMs, IGF1 and IGF1R mRNA levels were significantly higher in patients with diabetes compared to control subjects. In PBMCs, there were no statistically significant differences of IGF1, IGF1R, and IGFBP3 expression between diabetic and nondiabetic patients. In conclusion, our study indicated IGF1 and IGF1R differential expression in ERMs, but not in PBMCs, of diabetic and nondiabetic patients, suggesting that these factors can be involved in the pathogenesis or progression of proliferative vitreoretinal disorders. This trial is registered with NCT00841334.

  6. Rufinamide, an antiepileptic drug, improves cognition and increases neurogenesis in the aged gerbil hippocampal dentate gyrus via increasing expressions of IGF-1, IGF-1R and p-CREB.

    Science.gov (United States)

    Chen, Bai Hui; Ahn, Ji Hyeon; Park, Joon Ha; Song, Minah; Kim, Hyunjung; Lee, Tae-Kyeong; Lee, Jae Chul; Kim, Young-Myeong; Hwang, In Koo; Kim, Dae Won; Lee, Choong-Hyun; Yan, Bing Chun; Kang, Il Jun; Won, Moo-Ho

    2018-04-25

    Rufinamide is a novel antiepileptic drug and commonly used in the treatment of Lennox-Gastaut syndrome. In the present study, we investigated effects of rufinamide on cognitive function using passive avoidance test and neurogenesis in the hippocampal dentate gyrus using Ki-67 (a marker for cell proliferation), doublecortin (DCX, a marker for neuroblast) and BrdU/NeuN (markers for newly generated mature neurons) immunohistochemistry in aged gerbils. Aged gerbils (24-month old) were treated with 1 mg/kg and 3 mg/kg rufinamide for 4 weeks. Treatment with 3 mg/kg rufinamide, not 1 mg/kg rufinamide, significantly improved cognitive function and increased neurogenesis, showing that proliferating cells (Ki-67-immunoreactive cells), differentiating neuroblasts (DCX-immunoreactive neuroblasts) and mature neurons (BrdU/NeuN-immunoreactive cells) in the aged dentate gyrus compared with those in the control group. When we examined its mechanisms, rufinamide significantly increased immunoreactivities of insulin-like growth factor-1 (IGF-1), its receptor (IGF-1R), and phosphorylated cAMP response element binding protein (p-CREB). However, rufinamide did not show any increase in immunoreactivities of brain-derived neurotrophic factor and its receptor. Therefore, our results indicate that rufinamide can improve cognitive function and increase neurogenesis in the hippocampus of the aged gerbil via increasing expressions of IGF-1, IGF-1R and p-CREB. Copyright © 2018 Elsevier B.V. All rights reserved.

  7. S-nitrosylation of the IGF-1 receptor disrupts the cell proliferative action of IGF-1.

    Science.gov (United States)

    Okada, Kazushi; Zhu, Bao-Ting

    2017-09-30

    The insulin-like growth factor 1 receptor (IGF-1R) is a disulfide-linked heterotetramer containing two α-subunits and two β-subunits. Earlier studies demonstrate that nitric oxide (NO) can adversely affect IGF-1 action in the central nervous system. It is known that NO can induce S-nitrosylation of the cysteine residues in proteins, thereby partly contributing to the regulation of protein function. In the present study, we sought to determine whether S-nitrosylation of the cysteine residues in IGF-1R is an important post-translational modification that regulates its response to IGF-1. Using cultured SH-SY5Y human neuroblastoma cells as an in vitro model, we found that treatment of cells with S-nitroso-cysteine (SNOC), a NO donor that can nitrosylate the cysteine residues in proteins, induces S-nitrosylation of the β subunit of IGF-1R but not its α-subunit. IGF-1Rβ S-nitrosylation by SNOC is coupled with increased dissociation of the IGF-1R protein complex. In addition, disruption of the IGF-1R function resulting from S-nitrosylation of the IGF-1Rβ subunit is associated with disruption of the phosphoinositide 3-kinase (PI3K) and mitogen-activated protein kinase (MAPK) signaling pathways. Further, we observed that SNOC-induced IGF-1Rβ S-nitrosylation results in a dose-dependent inhibition of cell proliferation and survival. Together, these results suggest that elevated nitrosative stress may result in dysfunction of cellular IGF-1R signaling through S-nitrosylation of the cysteine residues in the IGF-1Rβ subunit, thereby disrupting the downstream PI3K and MAPK signaling functions and ultimately resulting in inhibition of cell proliferation and survival. Copyright © 2017. Published by Elsevier Inc.

  8. IGF-1 Receptor and adhesion signaling: an important axis in determining cancer cell phenotype and therapy resistance.

    Directory of Open Access Journals (Sweden)

    Orla T Cox

    2015-07-01

    Full Text Available IGF-1R expression and activation levels generally cannot be correlated in cancer cells, suggesting that cellular proteins may modulate IGF-1R activity. Strong candidates for such modulation are found in cell-matrix and cell-cell adhesion signaling complexes. Activated IGF-1R is present at focal adhesions, where it can stabilize β1 integrin and participate in signaling complexes that promote invasiveness associated with epithelial mesenchymal transition (EMT, and resistance to therapy. Whether IGF-1R contributes to EMT or to non-invasive tumor growth may be strongly influenced by the degree of ECM engagement and the presence or absence of key proteins in IGF-1R-cell adhesion complexes. One such protein is PDLIM2, which promotes both cell polarization and EMT by regulating the stability of transcription factors including NFκB, STATs and beta catenin. PDLIM2 exhibits tumor suppressor activity, but is also highly expressed in certain invasive cancers. It is likely that distinct adhesion complex proteins modulate IGF-1R signaling during cancer progression or adaptive responses to therapy. Thus, identifying the key modulators will be important for developing effective therapeutic strategies and predictive biomarkers.

  9. IGF-1R mRNA expression is increased in obese children.

    Science.gov (United States)

    Ricco, Rafaela Cristina; Ricco, Rubens Garcia; Queluz, Mariangela Carletti; de Paula, Mariana Teresa Sarti; Atique, Patricia Volpon; Custódio, Rodrigo José; Tourinho Filho, Hugo; Del Roio Liberatori, Raphael; Martinelli, Carlos Eduardo

    2018-04-01

    Obese children are often taller than age-matched subjects. Reports on GH and IGF-I levels in obese individuals are controversial, with normal and reduced GH-IGF-I levels having been reported in this group of patients. Thus, the aim of this study was to analyse insulin-like growth factor type 1 receptor (IGF-IR) mRNA expression in obese children. Forty-seven pre-pubertal children were included in this study: 29 were obese and taller than their target height, and 18 were normal eutrophic controls. Fasting blood samples were collected for IGF-IR mRNA expression in isolated lymphocytes and serum IGF-I, ALS, IGFBP-3, and IGFBP-1 concentration analysis. Relative IGF-IR gene expression (2 -ΔΔCT ) was significantly (P=0.025) higher in obese children (median 1.87) than in controls (1.15). Fourteen of the 29 obese subjects showed 2 -ΔΔCT values greater than or equal to 2, while only 2 individuals in the control group showed values above 2 (P=0.01). Obese children showed significantly (P=0.01) higher IGF-I concentrations than the control group (237ng/ml and 144ng/ml, respectively). Among obese patients, 65.5% had IGF-I values above the 75 percentile of the control group (P=0.02). ALS concentration was significantly (P=0.04) higher in the obese group, while IGFBP-3 levels were similar in obese and control children. IGFBP-1 concentration was lower in obese children, while insulin levels and HOMA-IR index were higher than in controls. The higher IGF-IR mRNA expression observed in obese children, associated with the higher IGF-I and ALS and the lower IGFBP-1 levels, suggest that the higher stature observed in these children may be due to increased IGF-I bioactivity. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Expression of IGF-1R and iNOS in nasal polyps; epithelial cell homeostasis and innate immune mechanisms in pathogenesis of nasal polyposis

    Czech Academy of Sciences Publication Activity Database

    Fundová, P.; Filipovský, T.; Funda, David P.; Hovorka, Ondřej; Holý, R.; Navara, M.; Tlaskalová, Helena

    2008-01-01

    Roč. 53, č. 6 (2008), s. 558-562 ISSN 0015-5632 R&D Projects: GA MZd NR8517 Institutional research plan: CEZ:AV0Z50200510 Keywords : nasal polyposis * igf -1r * inos Subject RIV: EC - Immunology Impact factor: 1.172, year: 2008

  11. MeCP2 silencing of LncRNA H19 controls hepatic stellate cell proliferation by targeting IGF1R

    International Nuclear Information System (INIS)

    Yang, Jing-Jing; Liu, Li-Ping; Tao, Hui; Hu, Wei; Shi, Peng; Deng, Zi-Yu; Li, Jun

    2016-01-01

    Highlights: • H19 plays a key role in HSCs proliferation and fibrosis. • MeCP2/H19 axis involvement in HSCs activation and fibrosis. • MeCP2 negative controls H19 expression in activated HSCs. • Identification of IGF1R as new target of H19 in HSC. - Abstract: Methyl-CpG-binding protein 2 (MeCP2) plays a key role in liver fibrosis. However, the potential mechanism of MeCP2 in liver fibrosis remains unclear. Early reports suggest that LncRNA H19 is important epigenetic regulator with critical roles in cell proliferation, but its role in hepatic fibrosis remains elusive. Sprague-Dawley rats liver fibrosis was generated by 12-weeks treatment with CCl 4 intraperitoneal injection. HSC-T6 cells were used in vitro study. The expression levels of MeCP2, H19, IGF1R, α-SMA, and Col1A1 were estimated by Western blotting, qRT-PCR and Immunohistochemistry. HSC-T6 cells were transfected with MeCP2-siRNA, pEGF-C1-MeCP2, pEX-3-H19, and H19-siRNA. Finally, cell proliferation ability was assessed by the MTT assay. Here, we found that H19 was significantly down-regulated in HSCs and fibrosis tissues, and an opposite pattern is observed for MeCP2 and IGF1R. Silencing of MeCP2 blocked HSCs proliferation. Knockdown of MeCP2 elevated H19 expression in activated HSCs, and over-expression of MeCP2 inhibited H19 expression in activated HSCs. Moreover, we investigated the effect of H19 on IGF1R expression. Overexpression of H19 in HSCs repressed the expression of IGF1R, and an opposite pattern is observed for H19 silenced. In addition, we reported that overexpression of H19 inhibited the TGF-β1-induced proliferation of HSCs. Furthermore, MeCP2 negative regulation of H19 by targeting the protein IGF1R. Taken together, these results demonstrated that MeCP2 silencing of H19 can alter the IGF1R overexpression, thus contributing to HSCs proliferation. These data could suggest the development of combination therapies that target the MeCP2.

  12. Type 1 IGF Receptor Localization in Paediatric Gliomas: Significant Association with WHO Grading and Clinical Outcome.

    Science.gov (United States)

    Clément, Florencia; Martin, Ayelen; Venara, Marcela; de Luján Calcagno, Maria; Mathó, Cecilia; Maglio, Silvana; Lombardi, Mercedes García; Bergadá, Ignacio; Pennisi, Patricia A

    2018-06-01

    Nuclear localization of insulin-like growth factor receptor type 1 (IGF-1R) has been described as adverse prognostic factor in some cancers. We studied the expression and localization of IGF-1R in paediatric patients with gliomas, as well as its association with World Health Organization (WHO) grading and survival. We conducted a single cohort, prospective study of paediatric patients with gliomas. Samples were taken at the time of the initial surgery; IGF-1R expression and localization were characterized by immunohistochemistry (IHC), subcellular fractionation and western blotting. Tumours (47/53) showed positive staining for IGF-1R by IHC. IGF-1R nuclear labelling was observed in 10/47 cases. IGF-1R staining was mostly non-nuclear in low-grade tumours, while IGF-1R nuclear labelling was predominant in high-grade gliomas (p = 0.0001). Survival was significantly longer in patients with gliomas having non-nuclear IGF-1R localization than in patients with nuclear IGF-1R tumours (p = 0.016). In gliomas, IGF-1R nuclear localization was significantly associated with both high-grade tumours and increased risk of death. Based on a prospective design, we provide evidence of a potential usefulness of intracellular localization of IGF-1R as prognostic factor in paediatric patients with gliomas.

  13. IGF-1 receptor inhibition by picropodophyllin in medulloblastoma

    Energy Technology Data Exchange (ETDEWEB)

    Ohshima-Hosoyama, Sachiko; Hosoyama, Tohru; Nelon, Laura D. [Greehey Children' s Cancer Research Institute, University of Texas Health Science Center, San Antonio, TX 78229 (United States); Keller, Charles, E-mail: keller@ohsu.edu [Greehey Children' s Cancer Research Institute, University of Texas Health Science Center, San Antonio, TX 78229 (United States); Department of Pediatrics, University of Texas Health Science Center, San Antonio, TX 78229 (United States); Department of Cellular and Structural Biology, University of Texas Health Science Center, San Antonio, TX 78229 (United States)

    2010-09-03

    Research highlights: {yields} Igf1r is overexpressed and activated in a Sonic Hedgehog driven model of medulloblastoma. {yields} Picropodophyllin targets and abrogates IGF signaling in medulloblastoma. {yields} Picropodophyllin inhibits medulloblastoma tumor cell growth by induction of apoptosis. -- Abstract: The insulin-like growth factor-1 receptor (Igf1r) is a multifunctional membrane-associated tyrosine kinase associated with regulation of transformation, proliferation, differentiation and apoptosis. Increased IGF pathway activity has been reported in human and murine medulloblastoma. Tumors from our genetically-engineered medulloblastoma mouse model over-express Igf1r, and thus this mouse model is a good platform with which to study the role of Igf1r in tumor progression. We hypothesize that inhibition of IGF pathway in medulloblastoma can slow or inhibit tumor growth and metastasis. To test our hypothesis, we tested the role of IGF in tumor growth in vitro by treatment with the tyrosine kinase small molecule inhibitor, picropodophyllin (PPP), which strongly inhibits the IGF pathway. Our results demonstrate that PPP-mediated downregulation of the IGF pathway inhibits mouse tumor cell growth and induces apoptotic cell death in vitro in primary medulloblastoma cultures that are most reflective of tumor cell behavior in vivo.

  14. IGF-1 receptor inhibition by picropodophyllin in medulloblastoma

    International Nuclear Information System (INIS)

    Ohshima-Hosoyama, Sachiko; Hosoyama, Tohru; Nelon, Laura D.; Keller, Charles

    2010-01-01

    Research highlights: → Igf1r is overexpressed and activated in a Sonic Hedgehog driven model of medulloblastoma. → Picropodophyllin targets and abrogates IGF signaling in medulloblastoma. → Picropodophyllin inhibits medulloblastoma tumor cell growth by induction of apoptosis. -- Abstract: The insulin-like growth factor-1 receptor (Igf1r) is a multifunctional membrane-associated tyrosine kinase associated with regulation of transformation, proliferation, differentiation and apoptosis. Increased IGF pathway activity has been reported in human and murine medulloblastoma. Tumors from our genetically-engineered medulloblastoma mouse model over-express Igf1r, and thus this mouse model is a good platform with which to study the role of Igf1r in tumor progression. We hypothesize that inhibition of IGF pathway in medulloblastoma can slow or inhibit tumor growth and metastasis. To test our hypothesis, we tested the role of IGF in tumor growth in vitro by treatment with the tyrosine kinase small molecule inhibitor, picropodophyllin (PPP), which strongly inhibits the IGF pathway. Our results demonstrate that PPP-mediated downregulation of the IGF pathway inhibits mouse tumor cell growth and induces apoptotic cell death in vitro in primary medulloblastoma cultures that are most reflective of tumor cell behavior in vivo.

  15. Upregulation of miR-150* and miR-630 induces apoptosis in pancreatic cancer cells by targeting IGF-1R.

    Directory of Open Access Journals (Sweden)

    Lulu Farhana

    Full Text Available MicroRNAs have been implicated in many critical cellular processes including apoptosis. We have previously found that apoptosis in pancreatic cancer cells was induced by adamantyl retinoid-related (ARR molecule 3-Cl-AHPC. Here we report that 3-Cl-AHPC-dependent apoptosis involves regulating a number of microRNAs including miR-150* and miR-630. 3-Cl-AHPC stimulated miR-150* expression and caused decreased expression of c-Myb and IGF-1R in the pancreatic cancer cells. 3-Cl-AHPC-mediated reduction of c-Myb resulted in diminished binding of c-Myb with IGF-1R and Bcl-2 promoters, thereby causing repression of their transcription and protein expression. Over-expression of miR-150* also resulted in diminished levels of c-Myb and Bcl-2 proteins. Furthermore, the addition of the miRNA inhibitor 2'-O-methylated miR-150 blocked 3-Cl-AHPC-mediated increase in miR-150* levels and abrogated loss of c-Myb protein. Knockdown of c-Myb in PANC-1 cells resulted in enhanced apoptosis both in the presence or absence of 3-Cl-AHPC confirming the anti-apoptotic property of c-Myb. Overexpression of miR-630 also induced apoptosis in the pancreatic cancer cells and inhibited target protein IGF-1R mRNA and protein expression. Together these results implicate key roles for miR-150* and miR-630 and their targeting of IGF-1R to promote apoptosis in pancreatic cancer cells.

  16. The fetal programming effect of prenatal smoking on Igf1r and Igf1 methylation is organ- and sex-specific.

    Science.gov (United States)

    Meyer, Karolin F; Verkaik-Schakel, Rikst Nynke; Timens, Wim; Kobzik, Lester; Plösch, Torsten; Hylkema, Machteld N

    2017-01-01

    The impact of prenatal smoke exposure (PSE) on DNA methylation has been demonstrated in blood samples from children of smoking mothers, but evidence for sex-dependent smoke-induced effects is limited. As the identified differentially methylated genes can be associated with developmental processes, and insulin-like growth factors (IGFs) play a critical role in prenatal tissue growth, we hypothesized that PSE induces fetal programming of Igf1r and Igf1. Using a mouse model of smoking during pregnancy, we show that PSE alters promoter methylation of Igf1r and Igf1 and deregulates their gene expression in lung and liver of fetal (E17.5) and neonatal (D3) mouse offspring. By further comparing female versus male, lung versus liver, or fetal versus neonatal time point, our results demonstrate that CpG site-specific aberrant methylation patterns sex-dependently vary per organ and time point. Moreover, PSE reduces gene expression of Igf1r and Igf1, dependent on organ, sex, and offspring's age. Our results indicate that PSE may be a source of organ-specific rather than general systemic fetal programming. This is exemplified here by gene promoter methylation and mRNA levels of Igf1r and Igf1, together with a sex- and organ-specific naturally established correlation of both parameters that is affected by prenatal smoke exposure. Moreover, the comparison of fetuses with neonates suggests a CpG site-dependent reversibility/persistence of PSE-induced differential methylation patterns.

  17. Gemcitabine-(5'-phosphoramidate)-[anti-IGF-1R]: molecular design, synthetic organic chemistry reactions, and antineoplastic cytotoxic potency in populations of pulmonary adenocarcinoma (A549).

    Science.gov (United States)

    Coyne, Cody P; Narayanan, Lakshmi

    2017-03-01

    One molecular-based approach that increases potency and reduces dose-limited sequela is the implementation of selective 'targeted' delivery strategies for conventional small molecular weight chemotherapeutic agents. Descriptions of the molecular design and organic chemistry reactions that are applicable for synthesis of covalent gemcitabine-monophosphate immunochemotherapeutics have to date not been reported. The covalent immunopharmaceutical, gemcitabine-(5'-phosphoramidate)-[anti-IGF-1R] was synthesized by reacting gemcitabine with a carbodiimide reagent to form a gemcitabine carbodiimide phosphate ester intermediate which was subsequently reacted with imidazole to create amine-reactive gemcitabine-(5'-phosphorylimidazolide) intermediate. Monoclonal anti-IGF-1R immunoglobulin was combined with gemcitabine-(5'-phosphorylimidazolide) resulting in the synthetic formation of gemcitabine-(5'-phosphoramidate)-[anti-IGF-1R]. The gemcitabine molar incorporation index for gemcitabine-(5'-phosphoramidate)-[anti-IGF-R1] was 2.67:1. Cytotoxicity Analysis - dramatic increases in antineoplastic cytotoxicity were observed at and between the gemcitabine-equivalent concentrations of 10 -9  M and 10 -7  M where lethal cancer cell death increased from 0.0% to a 93.1% maximum (100.% to 6.93% residual survival), respectively. Advantages of the organic chemistry reactions in the multistage synthesis scheme for gemcitabine-(5'-phosphoramidate)-[anti-IGF-1R] include their capacity to achieve high chemotherapeutic molar incorporation ratios; option of producing an amine-reactive chemotherapeutic intermediate that can be preserved for future synthesis applications; and non-dedicated organic chemistry reaction scheme that allows substitutions of either or both therapeutic moieties, and molecular delivery platforms. © 2016 The Authors Chemical Biology & Drug Design Published by John Wiley & Sons Ltd.

  18. BCL-2, in combination with MVP and IGF-1R expression, improves prediction of clinical outcome in complete response cervical carcinoma patients treated by radiochemotherapy.

    Science.gov (United States)

    Henríquez-Hernández, Luis Alberto; Lloret, Marta; Pinar, Beatriz; Bordón, Elisa; Rey, Agustín; Lubrano, Amina; Lara, Pedro Carlos

    2011-09-01

    To investigate whether BCL-2 expression would improve MVP/IGF-1R prediction of clinical outcome in cervix carcinoma patients treated by radiochemotherapy, and suggest possible mechanisms behind this effect. Fifty consecutive patients, who achieved complete response to treatment, from a whole series of 60 cases suffering from non-metastatic localized cervical carcinoma, were prospectively included in this study from July 1999 to December 2003. Follow-up was closed in January 2011. All patients received pelvic radiation (45-64.80 Gy in 1.8-2 Gy fractions) with concomitant cisplatin at 40 mg/m2/week doses followed by brachytherapy. Oncoprotein expression was studied by immunohistochemistry in paraffin-embedded tumour tissue. No relation was found between BCL-2 and clinicopathological variables. High MVP/IGF-1R/BCL-2 tumour expression was strongly related to poor local and regional disease-free survival (PMVP, and IGF-1R overexpression were related to poorer clinical outcome in cervical cancer patients who achieved clinical complete response to radiochemotherapy. The NHEJ repair protein Ku70/80 expression could be involved in the regulation of these oncoproteins. Copyright © 2011 Elsevier Inc. All rights reserved.

  19. IGF-1R and Leptin Expression Profile and the Effects of Metformin Treatment on Metabolic and Endocrine Parameters in PCOS Mice

    Directory of Open Access Journals (Sweden)

    Luis Eduardo Prado Correia

    2017-01-01

    Full Text Available We aim to assess the effects of metformin treatment on metabolic and endocrine parameters and genes expression related to the insulin-responsive pathway in polycystic ovary syndrome (PCOS. This study comprises twenty-eight obese mice divided into three metformin-treated groups for seven and twenty days and eight nonobese and nontreated ones. We found a significant decrease in glycemia after metformin treatment at days seven and twenty. However, we did not observe differences in body weight measurement. Histologically, after twenty days we observed follicular development with regression of androgenic effects. Levels of IGF-1R protein expression were low after twenty days of treatment, but LEP proteins showed an overexpression in the ovarian stroma. We assessed the IGF-1R and LEP mRNAs levels; data showed a significant overexpression of LEP after seven days of treatment, while the IGF-1R was downregulated. Metformin therapy seems to exert a beneficial effect on histological and anovulatory features, reducing follicular number and pyknosis formation, possibly involved in the reversion of androgenic stimulus. Expression of IGF-1 and LEPR indicates a relevant role in androgenic features reversion present in PCOS, hormonal equilibrium, body weight regulation, and glucose metabolism, therefore, under phenotype obesity and infertility regulation in this model.

  20. Effective molecular targeting of CDK4/6 and IGF-1R in a rare FUS-ERG fusion CDKN2A-deletion doxorubicin-resistant Ewing's sarcoma patient-derived orthotopic xenograft (PDOX) nude-mouse model.

    Science.gov (United States)

    Murakami, Takashi; Singh, Arun S; Kiyuna, Tasuku; Dry, Sarah M; Li, Yunfeng; James, Aaron W; Igarashi, Kentaro; Kawaguchi, Kei; DeLong, Jonathan C; Zhang, Yong; Hiroshima, Yukihiko; Russell, Tara; Eckardt, Mark A; Yanagawa, Jane; Federman, Noah; Matsuyama, Ryusei; Chishima, Takashi; Tanaka, Kuniya; Bouvet, Michael; Endo, Itaru; Eilber, Fritz C; Hoffman, Robert M

    2016-07-26

    Ewing's sarcoma is a rare and aggressive malignancy. In the present study, tumor from a patient with a Ewing's sarcoma with cyclin-dependent kinase inhibitor 2A/B (CDKN2A/B) loss and FUS-ERG fusion was implanted in the right chest wall of nude mice to establish a patient-derived orthotopic xenograft (PDOX) model. The aim of the present study was to determine efficacy of cyclin-dependent kinase 4/6 (CDK4/6) and insulin-like growth factor-1 receptor (IGF-1R) inhibitors on the Ewing's sarcoma PDOX. The PDOX models were randomized into the following groups when tumor volume reached 50 mm3: G1, untreated control; G2, doxorubicin (DOX) (intraperitoneal (i.p.) injection, weekly, for 2 weeks); G3, CDK4/6 inhibitor (palbociclib, PD0332991, per oral (p.o.), daily, for 14 days); G4, IGF-1R inhibitor (linsitinib, OSI-906, p.o., daily, for 14 days). Tumor growth was significantly suppressed both in G3 (palbociclib) and in G4 (linsitinib) compared to G1 (untreated control) at all measured time points. In contrast, DOX did not inhibit tumor growth at any time point, which is consistent with the failure of DOX to control tumor growth in the patient. The results of the present study demonstrate the power of the PDOX model to identify effective targeted molecular therapy of a recalcitrant DOX-resistant Ewing's sarcoma with specific genetic alterations. The results of this study suggest the potential of PDOX models for individually-tailored, effective targeted therapy for recalcitrant cancer.

  1. The insulin and IGF1 receptor kinase domains are functional dimers in the activated state

    Science.gov (United States)

    Cabail, M. Zulema; Li, Shiqing; Lemmon, Eric; Bowen, Mark E.; Hubbard, Stevan R.; Miller, W. Todd

    2015-03-01

    The insulin receptor (IR) and insulin-like growth factor-1 receptor (IGF1R) are highly related receptor tyrosine kinases with a disulfide-linked homodimeric architecture. Ligand binding to the receptor ectodomain triggers tyrosine autophosphorylation of the cytoplasmic domains, which stimulates catalytic activity and creates recruitment sites for downstream signalling proteins. Whether the two phosphorylated tyrosine kinase domains within the receptor dimer function independently or cooperatively to phosphorylate protein substrates is not known. Here we provide crystallographic, biophysical and biochemical evidence demonstrating that the phosphorylated kinase domains of IR and IGF1R form a specific dimeric arrangement involving an exchange of the juxtamembrane region proximal to the kinase domain. In this dimer, the active position of α-helix C in the kinase N lobe is stabilized, which promotes downstream substrate phosphorylation. These studies afford a novel strategy for the design of small-molecule IR agonists as potential therapeutic agents for type 2 diabetes.

  2. Cooperative ethylene receptor signaling

    OpenAIRE

    Liu, Qian; Wen, Chi-Kuang

    2012-01-01

    The gaseous plant hormone ethylene is perceived by a family of five ethylene receptor members in the dicotyledonous model plant Arabidopsis. Genetic and biochemical studies suggest that the ethylene response is suppressed by ethylene receptor complexes, but the biochemical nature of the receptor signal is unknown. Without appropriate biochemical measures to trace the ethylene receptor signal and quantify the signal strength, the biological significance of the modulation of ethylene responses ...

  3. 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.

  4. Effect of insulin analogues on insulin/IGF1 hybrid receptors: increased activation by glargine but not by its metabolites M1 and M2.

    Directory of Open Access Journals (Sweden)

    Cécile Pierre-Eugene

    Full Text Available BACKGROUND: In diabetic patients, the pharmacokinetics of injected human insulin does not permit optimal control of glycemia. Fast and slow acting insulin analogues have been developed, but they may have adverse properties, such as increased mitogenic or anti-apoptotic signaling. Insulin/IGF1 hybrid receptors (IR/IGF1R, present in most tissues, have been proposed to transmit biological effects close to those of IGF1R. However, the study of hybrid receptors is difficult because of the presence of IR and IGF1R homodimers. Our objective was to perform the first study on the pharmacological properties of the five marketed insulin analogues towards IR/IGF1R hybrids. METHODOLOGY: To study the effect of insulin analogues on IR/IGF1R hybrids, we used our previously developed Bioluminescence Resonance Energy Transfer (BRET assay that permits specific analysis of the pharmacological properties of hybrid receptors. Moreover, we have developed a new, highly sensitive BRET-based assay to monitor phophatidylinositol-3 phosphate (PIP(3 production in living cells. Using this assay, we performed a detailed pharmacological analysis of PIP(3 production induced by IGF1, insulin and insulin analogues in living breast cancer-derived MCF-7 and MDA-MB231 cells. RESULTS: Among the five insulin analogues tested, only glargine stimulated IR/IGF1R hybrids with an EC50 that was significantly lower than insulin and close to that of IGF1. Glargine more efficiently stimulated PIP(3 production in MCF-7 cells but not in MDA-MB231 cells as compared to insulin. In contrast, glargine metabolites M1 and M2 showed lower potency for hybrid receptors stimulation, PIP(3 production, Akt and Erk1/2 phosphorylation and DNA synthesis in MCF-7 cells, compared to insulin. CONCLUSION: Glargine, possibly acting through IR/IGF1R hybrids, displays higher potency, whereas its metabolites M1 and M2 display lower potency than insulin for the stimulation of proliferative/anti-apoptotic pathways in

  5. Dominant negative insulin-like growth factor-1 receptor inhibits neointimal formation through suppression of vascular smooth muscle cell migration and proliferation, and induction of apoptosis

    International Nuclear Information System (INIS)

    Lim, Hyun-Joung; Park, Hyun-Young; Ko, Young-Guk; Lee, Sea-Hyoung; Cho, Seung-Yeon; Lee, Eun Jig; Jameson, J. Larry; Jang, Yangsoo

    2004-01-01

    Blocking of the IGF-1 signaling pathway targeting the IGF-1 receptor (IGF-1R) provides a potential treatment strategy for restenosis. In this study, we have examined the effects of a dominant negative IGF-1R (IGF-1Rt) on primary rat VSMCs in vitro and on injured rat carotid artery in vivo. Ad/IGF-1Rt infection inhibited VSMC migration and proliferation, and it also induced apoptosis by inhibiting phosphorylation of Akt and phosphorylation of ERK1/2. Consistent with the anti-proliferative and apoptotic effects in vitro, the Ad/IGF-1Rt infection markedly reduced neointimal formation in carotid injury model. Ad/IGF-1Rt treated carotid arteries exhibited a suppressed proliferation index, PCNA expression, and also were stained positive for TUNEL assay. These results indicate that a dominant negative IGF-1R has the potential to reduce neointimal formation of injured rats' carotid arteries. The delivery of dominant negative IGF-1R by adenoviral or other vectors may provide a useful strategy for inhibiting restenosis after angioplasty

  6. MSM enhances GH signaling via the Jak2/STAT5b pathway in osteoblast-like cells and osteoblast differentiation through the activation of STAT5b in MSCs.

    Directory of Open Access Journals (Sweden)

    Youn Hee Joung

    Full Text Available Methylsulfonylmethane (MSM is a naturally occurring sulfur compound with well-known anti-oxidant properties and anti-inflammatory activities. But, its effects on bone are unknown. Growth hormone (GH is regulator of bone growth and bone metabolism. GH activates several signaling pathways such as the Janus kinase (Jak/signal transducers and activators of transcription (STAT pathway, thereby regulating expression of genes including insulin-like growth factor (IGF-1. GH exerts effects both directly and via IGF-1, which signals by activating the IGF-1 receptor (IGF-1R. In this study, we investigated the effects of MSM on the GH signaling via the Jak/STAT pathway in osteoblasts and the differentiation of primary bone marrow mesenchymal stem cells (MSCs. MSM was not toxic to osteoblastic cells and MSCs. MSM increased the expression of GH-related proteins including IGF-1R, p-IGF-1R, STAT5b, p-STAT5b, and Jak2 in osteoblastic cells and MSCs. MSM increased IGF-1R and GHR mRNA expression in osteoblastic cells. The expression of MSM-induced IGF-1R and GHR was inhibited by AG490, a Jak2 kinase inhibitor. MSM induced binding of STAT5 to the IGF-1R and increased IGF-1 and IGF-1R promoter activities. Analysis of cell extracts by immunoprecipitation and Western blot showed that MSM enhanced GH-induced activation of Jak2/STAT5b. We found that MSM and GH, separately or in combination, activated GH signaling via the Jak2/STAT5b pathway in UMR-106 cells. Using siRNA analysis, we found that STAT5b plays an essential role in GH signaling activation in C3H10T1/2 cells. Osteogenic marker genes (ALP, ON, OCN, BSP, OSX, and Runx2 were activated by MSM, and siRNA-mediated STAT5b knockdown inhibited MSM-induced expression of osteogenic markers. Furthermore, MSM increased ALP activity and the mineralization of MSCs. Taken together, these results indicated that MSM can promote osteogenic differentiation of MSCs through activation of STAT5b.

  7. Discovery of OSI-906: a selective and orally efficacious dual inhibitor of the IGF-1 receptor and insulin receptor.

    Science.gov (United States)

    Mulvihill, Mark J; Cooke, Andrew; Rosenfeld-Franklin, Maryland; Buck, Elizabeth; Foreman, Ken; Landfair, Darla; O'Connor, Matthew; Pirritt, Caroline; Sun, Yingchaun; Yao, Yan; Arnold, Lee D; Gibson, Neil W; Ji, Qun-Sheng

    2009-09-01

    The IGF-1 receptor (IGF-1R) has been implicated in the promotion of tumorigenesis, metastasis and resistance to cancer therapies. Therefore, this receptor has become a major focus for the development of anticancer agents. Our lead optimization efforts that blended structure-based design and empirical medicinal chemistry led to the discovery of OSI-906, a novel small-molecule dual IGF-1R/insulin receptor (IR) kinase inhibitor. OSI-906 potently and selectively inhibits autophosphorylation of both human IGF-1R and IR, displays in vitro antiproliferative effects in a variety of tumor cell lines and shows robust in vivo anti-tumor efficacy in an IGF-1R-driven xenograft model when administered orally once daily. OSI-906 is a novel, potent, selective and orally bioavailable dual IGF-1R/IR kinase inhibitor with favorable preclinical drug-like properties, which has demonstrated in vivo efficacy in tumor models and is currently in clinical testing.

  8. Haploinsufficiency of the insulin-like growth factor-1 receptor enhances endothelial repair and favorably modifies angiogenic progenitor cell phenotype.

    Science.gov (United States)

    Yuldasheva, Nadira Y; Rashid, Sheikh Tawqeer; Haywood, Natalie J; Cordell, Paul; Mughal, Romana; Viswambharan, Hema; Imrie, Helen; Sukumar, Piruthivi; Cubbon, Richard M; Aziz, Amir; Gage, Matthew; Mbonye, Kamatamu Amanda; Smith, Jessica; Galloway, Stacey; Skromna, Anna; Scott, D Julian A; Kearney, Mark T; Wheatcroft, Stephen B

    2014-09-01

    Defective endothelial regeneration predisposes to adverse arterial remodeling and is thought to contribute to cardiovascular disease in type 2 diabetes mellitus. We recently demonstrated that the type 1 insulin-like growth factor receptor (IGF1R) is a negative regulator of insulin sensitivity and nitric oxide bioavailability. In this report, we examined partial deletion of the IGF1R as a potential strategy to enhance endothelial repair. We assessed endothelial regeneration after wire injury in mice and abundance and function of angiogenic progenitor cells in mice with haploinsufficiency of the IGF1R (IGF1R(+/-)). Endothelial regeneration after arterial injury was accelerated in IGF1R(+/-) mice. Although the yield of angiogenic progenitor cells was lower in IGF1R(+/-) mice, these angiogenic progenitor cells displayed enhanced adhesion, increased secretion of insulin-like growth factor-1, and enhanced angiogenic capacity. To examine the relevance of IGF1R manipulation to cell-based therapy, we transfused IGF1R(+/-) bone marrow-derived CD117(+) cells into wild-type mice. IGF1R(+/-) cells accelerated endothelial regeneration after arterial injury compared with wild-type cells and did not alter atherosclerotic lesion formation. Haploinsufficiency of the IGF1R is associated with accelerated endothelial regeneration in vivo and enhanced tube forming and adhesive potential of angiogenic progenitor cells in vitro. Partial deletion of IGF1R in transfused bone marrow-derived CD117(+) cells enhanced their capacity to promote endothelial regeneration without altering atherosclerosis. Our data suggest that manipulation of the IGF1R could be exploited as novel therapeutic approach to enhance repair of the arterial wall after injury. © 2014 American Heart Association, Inc.

  9. Insulin-like growth factor 1 receptor expression in advanced non-small-cell lung cancer and its impact on overall survival

    Directory of Open Access Journals (Sweden)

    Humar Mojca

    2017-05-01

    Full Text Available The insulin-like growth factor 1 receptor (IGF1R expression has been addressed as a potential prognostic marker in non-small-cell lung cancer (NSCLC in various studies; however, the associations between IGF1R expression and prognosis of advanced NSCLC patients is still controversial. The aim of our observational, cohort study was to evaluate the expression of IGF1R in advanced NSCLC and its prognostic role. A subgroup analysis was performed to address the influence of pre-existing type 2 diabetes mellitus (T2DM status on IGF1R expression and overall survival (OS.

  10. Genetic blockade of insulin-like growth factor-1 receptor via recombinant adenovirus in lung cancer can be enhanced by the histone deacetylase inhibitor, vorinostat.

    Science.gov (United States)

    Park, Mi-Young; Kim, Dal Rae; Eo, Eun Young; Lim, Hyo Jeong; Park, Jong Sun; Cho, Young-Jae; Yoon, Ho-Il; Lee, Jae Ho; Lee, Choon-Taek

    2013-01-01

    Many approaches have been suggested as anti-tumor therapy for targeting insulin-like growth factor 1 receptor (IGF-1R), such as monoclonal antibodies and tyrosine kinase inhibitor. We introduced recombinant adenoviruses expressing antisense, dominant negative or short hairpin RNA to IGF-1R. Moreover, we demonstrated that histone deacetylase inhibitor (vorinostat) can increase the transduction efficiency of adenoviruses by increasing CAR-induced transduction and by enhancing the transcription of the adenoviral transgene. In the present study, we showed that the combination of ad-sh (short hairpin) IGF-1R with vorinostat leads to a synergistic enhancement of IGF-1R blockade. We measured the change in IGF-1R upon cotreatment with vorinostat and ad-shIGF-1R. Changes in transduction efficiency of ad-shIGF-1R were measured by fluorescent microscopy. Changes in apoptotic proportion and cell survival after the cotreatment were measured by the sub-G1 assay and cell counts. The effect of nuclear factor (NF)-κB activation was also measured by NF-κB p65 activation enzyme-linked immunosorbent assay. Drug interactions were analyzed upon cotreatment with ad-shIGF-1R, vorinostat and cisplatin. Combined treatment of ad-shIGF-1R and vorinostat synergistically suppressed the IGF-1R expression in lung cancer cell lines and also increased the transduction efficiency of ad-shIGF-1R. Ad-shIGF-1R and vorinostat cotreatment increased apoptotic cell death and synergistically suppressed cell growth compared to ad-shIGF-1R or vorinostat treatment alone. Vorinostat suppressed NF-κB activation, which was activated by ad-shIGF-1R. Moreover, triple combination of ad-shIGF-1R, vorinostat and cisplatin demonstrated synergistic cytotoxicity on lung cancer cells. Vorinostat enhanced the blocking capability of ad-shIGF-1R. The combined treatment of vorinostat and ad-sh-IGF-1R appears to have promising potential as a new therapeutic approach for lung cancer. Copyright © 2013 John Wiley & Sons, Ltd.

  11. Circulating Insulin-Like Growth Factor I Regulates Its Receptor in the Brain of Male Mice.

    Science.gov (United States)

    Trueba-Saiz, A; Fernandez, A M; Nishijima, T; Mecha, M; Santi, A; Munive, V; Aleman, I Torres

    2017-02-01

    The role of IGF-1 and its receptor (IGF-1R) in brain pathology is still unclear. Thus, either reduction of IGF-IR or treatment with IGF-1, two apparently opposite actions, has proven beneficial in brain diseases such as Alzheimer's dementia. A possible explanation of this discrepancy is that IGF-1 down-regulates brain IGF-1R levels, as previously seen in a mouse Alzheimer's dementia model. We now explored whether under normal conditions IGF-1 modulates its receptor. We first observed that in vitro, IGF-1 reduced IGF-1R mRNA levels in all types of brain cells including neurons, astrocytes, microglia, endothelial cells, and oligodendrocytes. IGF-1 also inhibited its own expression in neurons and brain endothelium. Next, we analyzed the in vivo actions of IGF-1. Because serum IGF-1 can enter the brain, we injected mice with IGF-1 ip. As soon as 1 hour after the injection, decreased hippocampal IGF-1 levels were observed, followed by increased IGF-1 and IGF-1R mRNAs 6 hours later. Because environmental enrichment (EE) stimulates the entrance of serum IGF-1 into the brain, we analyzed whether a physiological entrance of IGF-1 also produced changes in brain IGF-1R. Stimulation of IGF-1R by EE triggered a gradual decrease in hippocampal IGF-1 levels. After 6 hours of EE exposure, IGF-1 levels reached a significant decrease in parallel with increased IGF-1R expression. After longer times, IGF-1R mRNA levels returned to baseline. Thus, under nonpathological conditions, IGF-1 regulates brain IGF-1R. Because baseline IGF-1R levels are rapidly restored, a tight control of brain IGF-1R expression seems to operate under physiological conditions. Copyright © 2017 by the Endocrine Society.

  12. Insulin and IGF1 Receptors Are Essential for XX and XY Gonadal Differentiation and Adrenal Development in Mice

    Science.gov (United States)

    Romero, Yannick; Conne, Béatrice; Truong, Vy; Papaioannou, Marilena D.; Schaad, Olivier; Docquier, Mylène; Herrera, Pedro Luis; Wilhelm, Dagmar; Nef, Serge

    2013-01-01

    Mouse sex determination provides an attractive model to study how regulatory genetic networks and signaling pathways control cell specification and cell fate decisions. This study characterizes in detail the essential role played by the insulin receptor (INSR) and the IGF type I receptor (IGF1R) in adrenogenital development and primary sex determination. Constitutive ablation of insulin/IGF signaling pathway led to reduced proliferation rate of somatic progenitor cells in both XX and XY gonads prior to sex determination together with the downregulation of hundreds of genes associated with the adrenal, testicular, and ovarian genetic programs. These findings indicate that prior to sex determination somatic progenitors in Insr;Igf1r mutant gonads are not lineage primed and thus incapable of upregulating/repressing the male and female genetic programs required for cell fate restriction. In consequence, embryos lacking functional insulin/IGF signaling exhibit (i) complete agenesis of the adrenal cortex, (ii) embryonic XY gonadal sex reversal, with a delay of Sry upregulation and the subsequent failure of the testicular genetic program, and (iii) a delay in ovarian differentiation so that Insr;Igf1r mutant gonads, irrespective of genetic sex, remained in an extended undifferentiated state, before the ovarian differentiation program ultimately is initiated at around E16.5. PMID:23300479

  13. Anti-pancreatic cancer activity of ONC212 involves the unfolded protein response (UPR) and is reduced by IGF1-R and GRP78/BIP.

    Science.gov (United States)

    Lev, Avital; Lulla, Amriti R; Wagner, Jessica; Ralff, Marie D; Kiehl, Joshua B; Zhou, Yan; Benes, Cyril H; Prabhu, Varun V; Oster, Wolfgang; Astsaturov, Igor; Dicker, David T; El-Deiry, Wafik S

    2017-10-10

    Pancreatic cancer is chemo-resistant and metastasizes early with an overall five-year survival of ∼8.2%. First-in-class imipridone ONC201 is a small molecule in clinical trials with anti-cancer activity. ONC212, a fluorinated-ONC201 analogue, shows preclinical efficacy in melanoma and hepatocellular-cancer models. We investigated efficacy of ONC201 and ONC212 against pancreatic cancer cell lines ( N =16 including 9 PDX-cell lines). We demonstrate ONC212 efficacy in 4 in-vivo models including ONC201-resistant tumors. ONC212 is active in pancreatic cancer as single agent or in combination with 5-fluorouracil, irinotecan, oxaliplatin or RTK inhibitor crizotinib. Based on upregulation of pro-survival IGF1-R in some tumors, we found an active combination of ONC212 with inhibitor AG1024, including in vivo . We show a rationale for targeting pancreatic cancer using ONC212 combined with targeting the unfolded-protein response and ER chaperones such as GRP78/BIP. Our results lay the foundation to test imipridones, anti-cancer agents, in pancreatic cancer, that is refractory to most drugs.

  14. Nuclear targeting of IGF-1 receptor in orbital fibroblasts from Graves' disease: apparent role of ADAM17.

    Directory of Open Access Journals (Sweden)

    Neil Hoa

    Full Text Available Insulin-like growth factor-1 receptor (IGF-1R comprises two subunits, including a ligand binding domain on extra- cellular IGF-1Rα and a tyrosine phosphorylation site located on IGF-1Rβ. IGF-1R is over-expressed by orbital fibroblasts in the autoimmune syndrome, Graves' disease (GD. When activated by IGF-1 or GD-derived IgG (GD-IgG, these fibroblasts produce RANTES and IL-16, while those from healthy donors do not. We now report that IGF-1 and GD-IgG provoke IGF-1R accumulation in the cell nucleus of GD fibroblasts where it co-localizes with chromatin. Nuclear IGF-1R is detected with anti-IGF-1Rα-specific mAb and migrates to approximately 110 kDa, consistent with its identity as an IGF-1R fragment. Nuclear IGF-1R migrating as a 200 kDa protein and consistent with an intact receptor was undetectable when probed with either anti-IGF-1Rα or anti-IGF-1Rβ mAbs. Nuclear redistribution of IGF-1R is absent in control orbital fibroblasts. In GD fibroblasts, it can be abolished by an IGF-1R-blocking mAb, 1H7 and by physiological concentrations of glucocorticoids. When cell-surface IGF-1R is cross-linked with (125I IGF-1, (125I-IGF-1/IGF-1R complexes accumulate in the nuclei of GD fibroblasts. This requires active ADAM17, a membrane associated metalloproteinase, and the phosphorylation of IGF-1R. In contrast, virally encoded IGF-1Rα/GFP fusion protein localizes equivalently in nuclei in both control and GD fibroblasts. This result suggests that generation of IGF-1R fragments may limit the accumulation of nuclear IGF-1R. We thus identify a heretofore-unrecognized behavior of IGF-1R that appears limited to GD-derived fibroblasts. Nuclear IGF-1R may play a role in disease pathogenesis.

  15. Nuclear insulin-like growth factor 1 receptor phosphorylates proliferating cell nuclear antigen and rescues stalled replication forks after DNA damage.

    Science.gov (United States)

    Waraky, Ahmed; Lin, Yingbo; Warsito, Dudi; Haglund, Felix; Aleem, Eiman; Larsson, Olle

    2017-11-03

    We have previously shown that the insulin-like growth factor 1 receptor (IGF-1R) translocates to the cell nucleus, where it binds to enhancer-like regions and increases gene transcription. Further studies have demonstrated that nuclear IGF-1R (nIGF-1R) physically and functionally interacts with some nuclear proteins, i.e. the lymphoid enhancer-binding factor 1 (Lef1), histone H3, and Brahma-related gene-1 proteins. In this study, we identified the proliferating cell nuclear antigen (PCNA) as a nIGF-1R-binding partner. PCNA is a pivotal component of the replication fork machinery and a main regulator of the DNA damage tolerance (DDT) pathway. We found that IGF-1R interacts with and phosphorylates PCNA in human embryonic stem cells and other cell lines. In vitro MS analysis of PCNA co-incubated with the IGF-1R kinase indicated tyrosine residues 60, 133, and 250 in PCNA as IGF-1R targets, and PCNA phosphorylation was followed by mono- and polyubiquitination. Co-immunoprecipitation experiments suggested that these ubiquitination events may be mediated by DDT-dependent E2/E3 ligases ( e.g. RAD18 and SHPRH/HLTF). Absence of IGF-1R or mutation of Tyr-60, Tyr-133, or Tyr-250 in PCNA abrogated its ubiquitination. Unlike in cells expressing IGF-1R, externally induced DNA damage in IGF-1R-negative cells caused G 1 cell cycle arrest and S phase fork stalling. Taken together, our results suggest a role of IGF-1R in DDT. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  16. The association of TP53 mutations with the resistance of colorectal carcinoma to the insulin-like growth factor-1 receptor inhibitor picropodophyllin

    International Nuclear Information System (INIS)

    Wang, Quan; Wei, Feng; Lv, Guoyue; Li, Chunsheng; Liu, Tongjun; Hadjipanayis, Costas G; Zhang, Guikai; Hao, Chunhai; Bellail, Anita C

    2013-01-01

    There is growing evidence indicating the insulin-like growth factor 1 receptor (IGF-1R) plays a critical role in the progression of human colorectal carcinomas. IGF-1R is an attractive drug target for the treatment of colon cancer. Picropodophyllin (PPP), of the cyclolignan family, has recently been identified as an IGF-1R inhibitor. The aim of this study is to determine the therapeutic response and mechanism after colorectal carcinoma treatment with PPP. Seven colorectal carcinoma cell lines were treated with PPP. Following treatment, cells were analyzed for growth by a cell viability assay, sub-G1 apoptosis by flow cytometry, caspase cleavage and activation of AKT and extracellular signal-regulated kinase (ERK) by western blot analysis. To examine the in vivo therapeutic efficacy of PPP, mice implanted with human colorectal carcinoma xenografts underwent PPP treatment. PPP treatment blocked the phosphorylation of IGF-1R, AKT and ERK and inhibited the growth of TP53 wild-type but not mutated colorectal carcinoma cell lines. The treatment of PPP also induced apoptosis in TP53 wild-type cells as evident by the presence of sub-G1 cells and the cleavage of caspase-9, caspase-3, DNA fragmentation factor-45 (DFF45), poly (ADP-ribose) polymerase (PARP), and X-linked inhibitor of apoptosis protein (XIAP). The loss of BAD phosphorylation in the PPP-treated TP53 wild type cells further suggested that the treatment induced apoptosis through the BAD-mediated mitochondrial pathway. In contrast, PPP treatment failed to induce the phosphorylation of AKT and ERK and caspase cleavage in TP53 mutated colorectal carcinoma cell lines. Finally, PPP treatment suppressed the growth of xenografts derived from TP53 wild type but not mutated colorectal carcinoma cells. We report the association of TP53 mutations with the resistance of treatment of colorectal carcinoma cells in culture and in a xenograft mouse model with the IGF-1R inhibitor PPP. TP53 mutations often occur in colorectal

  17. Heat shock protein 90-sheltered overexpression of insulin-like growth factor 1 receptor contributes to malignancy of thymic epithelial tumors.

    Science.gov (United States)

    Breinig, Marco; Mayer, Philipp; Harjung, Andreas; Goeppert, Benjamin; Malz, Mona; Penzel, Roland; Neumann, Olaf; Hartmann, Arndt; Dienemann, Hendrik; Giaccone, Giuseppe; Schirmacher, Peter; Kern, Michael André; Chiosis, Gabriela; Rieker, Ralf Joachim

    2011-04-15

    The underlying molecular mechanisms of thymic epithelial malignancies (TEMs) are poorly understood. Consequently, there is a lack of efficacious targeted therapies and patient prognosis remains dismal, particularly for advanced TEMs. We sought to investigate protumorigenic mechanism relevant to this understudied cancer. Recently established cell lines derived from thymic epithelial tumors were used as a model system. The antitumor activity of specific heat shock protein 90 (Hsp90) inhibitors was investigated by an analysis of cell viability, cell cycle, and apoptosis using MTT-assays and flow cytometry. Western blotting was used to investigate the altered expression of Hsp90 clients. Pharmacological inhibitors against select Hsp90 clients, as well as RNAi, were employed to test the relevance of each client independently. Tissue microarray analysis was performed to match the in vitro findings with observations obtained from patient-derived samples. Hsp90 inhibition significantly reduces cell viability of thymic carcinoma cells, induces cell cycle arrest and apoptosis, and blocks invasiveness. Hsp90 inhibition triggers the degradation of multiple oncogenic clients, for example insulin-like growth factor 1 receptor (IGF-1R), CDK4, and the inactivation of PI3K/Akt and RAF/Erk signaling. Mechanistically, the IGF/IGF-1R-signaling axis contributes to the establishment of the antiapoptotic phenotype of thymic cancer cells. Finally, IGF-1R is overexpressed in advanced TEMs. We have unraveled a novel protumorigenic mechanism in TEMs, namely Hsp90-capacitated overexpression of IGF-1R, which confers apoptosis evasion in malignant thymic epithelial cells. Our data indicate that Hsp90 inhibition, which simultaneously blocks multiple cancer hallmarks, represents a therapeutic strategy in TEMs that may merit evaluation in clinical trials. ©2011 AACR.

  18. MicroRNA-133a suppresses multiple oncogenic membrane receptors and cell invasion in non-small cell lung carcinoma.

    Directory of Open Access Journals (Sweden)

    Lu-Kai Wang

    Full Text Available Non-small cell lung cancers (NSCLCs cause high mortality worldwide, and the cancer progression can be activated by several genetic events causing receptor dysregulation, including mutation or amplification. MicroRNAs are a group of small non-coding RNA molecules that function in gene silencing and have emerged as the fine-tuning regulators during cancer progression. MiR-133a is known as a key regulator in skeletal and cardiac myogenesis, and it acts as a tumor suppressor in various cancers. This study demonstrates that miR-133a expression negatively correlates with cell invasiveness in both transformed normal bronchial epithelial cells and lung cancer cell lines. The oncogenic receptors in lung cancer cells, including insulin-like growth factor 1 receptor (IGF-1R, TGF-beta receptor type-1 (TGFBR1, and epidermal growth factor receptor (EGFR, are direct targets of miR-133a. MiR-133a can inhibit cell invasiveness and cell growth through suppressing the expressions of IGF-1R, TGFBR1 and EGFR, which then influences the downstream signaling in lung cancer cell lines. The cell invasive ability is suppressed in IGF-1R- and TGFBR1-repressed cells and this phenomenon is mediated through AKT signaling in highly invasive cell lines. In addition, by using the in vivo animal model, we find that ectopically-expressing miR-133a dramatically suppresses the metastatic ability of lung cancer cells. Accordingly, patients with NSCLCs who have higher expression levels of miR-133a have longer survival rates compared with those who have lower miR-133a expression levels. In summary, we identified the tumor suppressor role of miR-133a in lung cancer outcome prognosis, and we demonstrated that it targets several membrane receptors, which generally produce an activating signaling network during the progression of lung cancer.

  19. Prenatal stress affects insulin-like growth factor-1 (IGF-1) level and IGF-1 receptor phosphorylation in the brain of adult rats.

    Science.gov (United States)

    Basta-Kaim, Agnieszka; Szczesny, Ewa; Glombik, Katarzyna; Stachowicz, Katarzyna; Slusarczyk, Joanna; Nalepa, Irena; Zelek-Molik, Agnieszka; Rafa-Zablocka, Katarzyna; Budziszewska, Boguslawa; Kubera, Marta; Leskiewicz, Monika; Lason, Wladyslaw

    2014-09-01

    It has been shown that stressful events occurring in early life have a powerful influence on the development of the central nervous system. Insulin-like growth factor-1 (IGF-1) promotes the growth, differentiation and survival of both neurons and glial cells and is thought to exert antidepressant-like activity. Thus, it is possible that disturbances in the function of the IGF-1 system may be responsible for disturbances observed over the course of depression. Prenatal stress was used as a valid model of depression. Adult male offspring of control and stressed rat dams were subjected to behavioural testing (forced swim test). The level of IGF-1 in the blood and the expression of IGF-1, IGF-1R, and IRS-1/2 in the hippocampus and frontal cortex using RT-PCR, ELISA and western blotting were measured. In addition the effect of intracerebroventricularly administered IGF-1 and/or the IGF-1R receptor antagonist JB1 in the forced swim test was studied. Prenatally stressed rats showed depressive like behaviour, including increased immobility time as well as decreased mobility and climbing. Intracerebroventricular administration of IGF-1 reversed these effects in stressed animals, whereas concomitant administration of the IGF-1R antagonist JB1 completely blocked the effects. Biochemical analysis of homogenates from the hippocampus and frontal cortex revealed decreases in IGF-1 level and IGF-1R phosphorylation along with disturbances in IRS-1 phosphorylation. These findings reveal that prenatal stress alters IGF-1 signalling, which may contribute to the behavioural changes observed in depression. Copyright © 2014 Elsevier B.V. and ECNP. All rights reserved.

  20. Crosstalk between TEMs and endothelial cells modulates angiogenesis and metastasis via IGF1-IGF1R signalling in epithelial ovarian cancer

    OpenAIRE

    Wang, Xinjing; Zhu, Qinyi; Lin, Yingying; Wu, Li; Wu, Xiaoli; Wang, Kai; He, Qizhi; Xu, Congjian; Wan, Xiaoping; Wang, Xipeng

    2017-01-01

    Background: Epithelial ovarian cancer (EOC) is the leading cause of death from gynaecologic malignancies and has a poor prognosis due to metastasis. Drugs targeting the angiogenesis pathway significantly improve patient outcome. However, the key factors linking angiogenesis and metastasis have not been elucidated. In this study, we found Tie2 expressing monocytes (CD14+Tie2+, TEMs) as key contributors to angiogenesis and metastasis of EOC. Methods: Tissue slides were evaluated by immunofluore...

  1. IGF-1 signaling mediated cell-specific skeletal mechano-transduction.

    Science.gov (United States)

    Tian, Faming; Wang, Yongmei; Bikle, Daniel D

    2018-02-01

    Mechanical loading preserves bone mass and stimulates bone formation, whereas skeletal unloading leads to bone loss. In addition to osteocytes, which are considered the primary sensor of mechanical load, osteoblasts, and bone specific mesenchymal stem cells also are involved. The skeletal response to mechanical signals is a complex process regulated by multiple signaling pathways including that of insulin-like growth factor-1 (IGF-1). Conditional osteocyte deletion of IGF-1 ablates the osteogenic response to mechanical loading. Similarly, osteocyte IGF-1 receptor (IGF-1R) expression is necessary for reloading-induced periosteal bone formation. Transgenic overexpression of IGF-1 in osteoblasts results in enhanced responsiveness to in vivo mechanical loading in mice, a response which is eliminated by osteoblastic conditional disruption of IGF-1 in vivo. Bone marrow derived stem cells (BMSC) from unloaded bone fail to respond to IGF-1 in vitro. IGF-1R is required for the transduction of a mechanical stimulus to downstream effectors, transduction which is lost when the IGF-1R is deleted. Although the molecular mechanisms are not yet fully elucidated, the IGF signaling pathway and its interactions with potentially interlinked signaling cascades involving integrins, the estrogen receptor, and wnt/β-catenin play an important role in regulating adaptive response of cancer bone cells to mechanical stimuli. In this review, we discuss recent advances investigating how IGF-1 and other interlinked molecules and signaling pathways regulate skeletal mechano-transduction involving different bone cells, providing an overview of the IGF-1 signaling mediated cell-specific response to mechanical stimuli. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:576-583, 2018. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  2. Prostaglandin Receptor Signaling in Disease

    Directory of Open Access Journals (Sweden)

    Toshiyuki Matsuoka

    2007-01-01

    Full Text Available Prostanoids, consisting of the prostaglandins (PGs and the thromboxanes (TXs, are a group of lipid mediators formed in response to various stimuli. They include PGD2, PGE2, PGF2α, PGI2, and TXA2. They are released outside of the cells immediately after synthesis, and exert their actions by binding to a G-protein coupled rhodopsin-type receptor on the surface of target cells. There are eight types of the prostanoid receptors conserved in mammals from mouse to human. They are the PGD receptor (DP, four subtypes of the PGE receptor (EP1, EP2, EP3, and EP4, the PGF receptor (FP, PGI receptor (IP, and TXA receptor (TP. Recently, mice deficient in each of these prostanoid receptors were generated and subjected to various experimental models of disease. These studies have revealed the roles of PG receptor signaling in various pathological conditions, and suggest that selective manipulation of the prostanoid receptors may be beneficial in treatment of the pathological conditions. Here we review these recent findings of roles of prostanoid receptor signaling and their therapeutic implications.

  3. Nuclear Receptor Signaling Atlas (NURSA)

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Nuclear Receptor Signaling Atlas (NURSA) is designed to foster the development of a comprehensive understanding of the structure, function, and role in disease...

  4. The Heart Protection Effect of Alcalase Potato Protein Hydrolysate Is through IGF1R-PI3K-Akt Compensatory Reactivation in Aging Rats on High Fat Diets

    Directory of Open Access Journals (Sweden)

    Wei-Syun Hu

    2015-05-01

    Full Text Available The prevalence of obesity is high in older adults. Alcalase potato protein hydrolysate (APPH, a nutraceutical food, might have greater benefits and be more economical than hypolipidemic drugs. In this study, serum lipid profiles and heart protective effects were evaluated in high fat diet (HFD induced hyperlipidemia in aging rats treated with APPH (15, 45 and 75 mg/kg/day and probucol (500 mg/kg/day. APPH treatments reduced serum triacylglycerol (TG, total cholesterol (TC, and low density lipoprotein (LDL levels to the normal levels expressed in the control group. Additionally, the IGF1R-PI3K-Akt survival pathway was reactivated, and Fas-FADD (Fas-associated death domain induced apoptosis was inhibited by APPH treatments (15 and 45 mg/kg/day in HFD aging rat hearts. APPH (75 mg/kg/day rather than probucol (500 mg/kg/day treatment could reduce serum lipids without affecting HDL expression. The heart protective effect of APPH in aging rats with hyperlipidemia was through lowering serum lipids and enhancing the activation of the compensatory IGF1R-PI3K-Akt survival pathway.

  5. The Heart Protection Effect of Alcalase Potato Protein Hydrolysate Is through IGF1R-PI3K-Akt Compensatory Reactivation in Aging Rats on High Fat Diets

    Science.gov (United States)

    Hu, Wei-Syun; Ting, Wei-Jen; Chiang, Wen-Dee; Pai, Peiying; Yeh, Yu-Lan; Chang, Chung-Ho; Lin, Wan-Teng; Huang, Chih-Yang

    2015-01-01

    The prevalence of obesity is high in older adults. Alcalase potato protein hydrolysate (APPH), a nutraceutical food, might have greater benefits and be more economical than hypolipidemic drugs. In this study, serum lipid profiles and heart protective effects were evaluated in high fat diet (HFD) induced hyperlipidemia in aging rats treated with APPH (15, 45 and 75 mg/kg/day) and probucol (500 mg/kg/day). APPH treatments reduced serum triacylglycerol (TG), total cholesterol (TC), and low density lipoprotein (LDL) levels to the normal levels expressed in the control group. Additionally, the IGF1R-PI3K-Akt survival pathway was reactivated, and Fas-FADD (Fas-associated death domain) induced apoptosis was inhibited by APPH treatments (15 and 45 mg/kg/day) in HFD aging rat hearts. APPH (75 mg/kg/day) rather than probucol (500 mg/kg/day) treatment could reduce serum lipids without affecting HDL expression. The heart protective effect of APPH in aging rats with hyperlipidemia was through lowering serum lipids and enhancing the activation of the compensatory IGF1R-PI3K-Akt survival pathway. PMID:25950762

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

    International Nuclear Information System (INIS)

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

    2013-01-01

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

  7. The dog as a naturally-occurring model for insulin-like growth factor type 1 receptor-overexpressing breast cancer: an observational cohort study

    International Nuclear Information System (INIS)

    Jaillardon, Laetitia; Abadie, Jérome; Godard, Tiffanie; Campone, Mario; Loussouarn, Delphine; Siliart, Brigitte; Nguyen, Frédérique

    2015-01-01

    Dogs spontaneously develop invasive mammary carcinoma with a high prevalence of the triple-negative (TN) subtype (lack of ER-Estrogen Receptor and PR-Progesterone Receptor expression, lack of HER2-Human Epidermal Growth Factor Receptor 2 overexpression), making this animal model relevant for investigating new therapeutic pathways. Insulin-like growth factor Type-1 receptor (IGF1R) is frequently overexpressed in primary human breast cancers, with a growing role in the TN phenotype. The purpose of this study was to investigate the Dog as a candidate model for IGF1R-overexpressing mammary carcinoma. 150 bitches with canine mammary carcinoma (CMC) and a known 2-year follow-up were retrospectively included. IGF1R expression was assessed by immunohistochemistry (IHC) using a similar scoring system as for HER2 in breast cancer. The prognostic value of the IGF1R expression was assessed in terms of overall and specific survival as well as disease-free interval (DFI). 47 CMC (31 %) were classified as luminal and 103 (69 %) as triple-negative (TN-CMC). 41 % of CMC overexpressed IGF1R (IHC score 3+) of which 76 % were TN-CMC and 62 % grade III. IGF1R overexpression was associated with aggressive features including lymphovascular invasion, histological grade III, low ER expression and the TN phenotype. Univariate and multivariate analyses revealed that IGF1R overexpression was associated with shorter overall and specific survivals and shorter DFI in TN-CMC. IGF1R overexpression is common and related to a poor outcome in canine invasive mammary carcinoma, particularly in the triple negative subtype, as in human breast cancer. Preclinical studies using the Dog as a spontaneous animal model could be considered to investigate new therapies targeting IGF1R in triple-negative breast cancer. The online version of this article (doi:10.1186/s12885-015-1670-6) contains supplementary material, which is available to authorized users

  8. IGF-1 receptor targeted nanoparticles for image-guided therapy of stroma-rich and drug resistant human cancer.

    Science.gov (United States)

    Zhou, Hongyu; Qian, Weiping; Uckun, Fatih M; Zhou, Zhiyang; Wang, Liya; Wang, Andrew; Mao, Hui; Yang, Lily

    2016-04-17

    Low drug delivery efficiency and drug resistance from highly heterogeneous cancer cells and tumor microenvironment represent major challenges in clinical oncology. Growth factor receptor, IGF-1R, is overexpressed in both human tumor cells and tumor associated stromal cells. The level of IGF-1R expression is further up-regulated in drug resistant tumor cells. We have developed IGF-1R targeted magnetic iron oxide nanoparticles (IONPs) carrying multiple anticancer drugs into human tumors. This IGF-1R targeted theranostic nanoparticle delivery system has an iron core for non-invasive MR imaging, amphiphilic polymer coating to ensure the biocompatibility as well as for drug loading and conjugation of recombinant human IGF-1 as targeting molecules. Chemotherapy drugs, Doxorubicin (Dox), was encapsulated into the polymer coating and/or conjugated to the IONP surface by coupling with the carboxyl groups. The ability of IGF1R targeted theranostic nanoparticles to penetrate tumor stromal barrier and enhance tumor cell killing has been demonstrated in human pancreatic cancer patient tissue derived xenograft (PDX) models. Repeated systemic administrations of those IGF-1R targeted theranostic IONP carrying Dox led to breaking the tumor stromal barrier and improved therapeutic effect. Near infrared (NIR) optical and MR imaging enabled noninvasive monitoring of nanoparticle-drug delivery and therapeutic responses. Our results demonstrated that IGF-1R targeted nanoparticles carrying multiple drugs are promising combination therapy approaches for image-guided therapy of stroma-rich and drug resistant human cancer, such as pancreatic cancer.

  9. IGF-1 receptor targeted nanoparticles for image-guided therapy of stroma-rich and drug resistant human cancer

    Science.gov (United States)

    Zhou, Hongyu; Qian, Weiping; Uckun, Fatih M.; Zhou, Zhiyang; Wang, Liya; Wang, Andrew; Mao, Hui; Yang, Lily

    2016-05-01

    Low drug delivery efficiency and drug resistance from highly heterogeneous cancer cells and tumor microenvironment represent major challenges in clinical oncology. Growth factor receptor, IGF-1R, is overexpressed in both human tumor cells and tumor associated stromal cells. The level of IGF-1R expression is further up-regulated in drug resistant tumor cells. We have developed IGF-1R targeted magnetic iron oxide nanoparticles (IONPs) carrying multiple anticancer drugs into human tumors. This IGF-1R targeted theranostic nanoparticle delivery system has an iron core for non-invasive MR imaging, amphiphilic polymer coating to ensure the biocompatibility as well as for drug loading and conjugation of recombinant human IGF-1 as targeting molecules. Chemotherapy drugs, Doxorubicin (Dox), was encapsulated into the polymer coating and/or conjugated to the IONP surface by coupling with the carboxyl groups. The ability of IGF1R targeted theranostic nanoparticles to penetrate tumor stromal barrier and enhance tumor cell killing has been demonstrated in human pancreatic cancer patient tissue derived xenograft (PDX) models. Repeated systemic administrations of those IGF-1R targeted theranostic IONP carrying Dox led to breaking the tumor stromal barrier and improved therapeutic effect. Near infrared (NIR) optical and MR imaging enabled noninvasive monitoring of nanoparticle-drug delivery and therapeutic responses. Our results demonstrated that IGF-1R targeted nanoparticles carrying multiple drugs are promising combination therapy approaches for image-guided therapy of stroma-rich and drug resistant human cancer, such as pancreatic cancer.

  10. Insulin-like growth factor 1 signaling is essential for mitochondrial biogenesis and mitophagy in cancer cells.

    Science.gov (United States)

    Lyons, Amy; Coleman, Michael; Riis, Sarah; Favre, Cedric; O'Flanagan, Ciara H; Zhdanov, Alexander V; Papkovsky, Dmitri B; Hursting, Stephen D; O'Connor, Rosemary

    2017-10-13

    Mitochondrial activity and metabolic reprogramming influence the phenotype of cancer cells and resistance to targeted therapy. We previously established that an insulin-like growth factor 1 (IGF-1)-inducible mitochondrial UTP carrier (PNC1/SLC25A33) promotes cell growth. This prompted us to investigate whether IGF signaling is essential for mitochondrial maintenance in cancer cells and whether this contributes to therapy resistance. Here we show that IGF-1 stimulates mitochondrial biogenesis in a range of cell lines. In MCF-7 and ZR75.1 breast cancer cells, IGF-1 induces peroxisome proliferator-activated receptor γ coactivator 1β (PGC-1β) and PGC-1α-related coactivator (PRC). Suppression of PGC-1β and PRC with siRNA reverses the effects of IGF-1 and disrupts mitochondrial morphology and membrane potential. IGF-1 also induced expression of the redox regulator nuclear factor-erythroid-derived 2-like 2 (NFE2L2 alias NRF-2). Of note, MCF-7 cells with acquired resistance to an IGF-1 receptor (IGF-1R) tyrosine kinase inhibitor exhibited reduced expression of PGC-1β, PRC, and mitochondrial biogenesis. Interestingly, these cells exhibited mitochondrial dysfunction, indicated by reactive oxygen species expression, reduced expression of the mitophagy mediators BNIP3 and BNIP3L, and impaired mitophagy. In agreement with this, IGF-1 robustly induced BNIP3 accumulation in mitochondria. Other active receptor tyrosine kinases could not compensate for reduced IGF-1R activity in mitochondrial protection, and MCF-7 cells with suppressed IGF-1R activity became highly dependent on glycolysis for survival. We conclude that IGF-1 signaling is essential for sustaining cancer cell viability by stimulating both mitochondrial biogenesis and turnover through BNIP3 induction. This core mitochondrial protective signal is likely to strongly influence responses to therapy and the phenotypic evolution of cancer. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

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

    OpenAIRE

    Yee, Douglas

    2012-01-01

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

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

    DEFF Research Database (Denmark)

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

    2014-01-01

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

  13. Evidence That Graves' Ophthalmopathy Immunoglobulins Do Not Directly Activate IGF-1 Receptors.

    Science.gov (United States)

    Marcus-Samuels, Bernice; Krieger, Christine C; Boutin, Alisa; Kahaly, George J; Neumann, Susanne; Gershengorn, Marvin C

    2018-05-01

    Graves' ophthalmopathy (GO) pathogenesis involves thyrotropin (TSH) receptor (TSHR)-stimulating autoantibodies. Whether there are autoantibodies that directly stimulate insulin-like growth factor 1 receptors (IGF-1Rs), stimulating insulin-like growth factor receptor antibodies (IGFRAbs), remains controversial. This study attempted to determine whether there are stimulating IGFRAbs in patients with GO. Immunoglobulins (Igs) were purified from normal volunteers (NV-Igs) and patients with GO (GO-Igs). The effects of TSH, IGF-1, NV-Igs, and GO-Igs on pAKT and pERK1/2, members of pathways used by IGF-1R and TSHR, were compared in orbital fibroblasts from GO patients (GOFs) and U2OS-TSHR cells overexpressing TSHRs, and U2OS cells that express TSHRs at very low endogenous levels. U2OS-TSHR and U2OS cells were used because GOFs are not easily manipulated using molecular techniques such as transfection, and U2OS cells because they express TSHRs at levels that do not measurably stimulate signaling. Thus, comparing U2OS-TSHR and U2OS cells permits specifically distinguishing signaling mediated by the TSHR and IGF-1R. In GOFs, all GO-Igs stimulated pERK1/2 formation and 69% stimulated pAKT. In U2OS-TSHR cells, 15% of NV-IGs and 83% of GO-Igs stimulated increases in pERK1/2, whereas all NV-Igs and GO-Igs stimulated increases in pAKT. In U2OS cells, 70% of GO-Igs stimulated small increases in pAKT. Knockdown of IGF-1R caused a 65 ± 6.3% decrease in IGF-1-stimulated pAKT but had no effect on GO-Igs stimulation of pAKT. Thus, GO-Igs contain factor(s) that stimulate pAKT formation. However, this factor(s) does not directly activate IGF-1R. Based on the findings analyzing these two signaling pathways, it is concluded there is no evidence of stimulating IGFRAbs in GO patients.

  14. Insulin-like growth factor-1 receptor overexpression is associated with outcome in invasive urothelial carcinoma of urinary bladder: a retrospective study of patients treated using radical cystectomy.

    Science.gov (United States)

    Gonzalez-Roibon, Nilda; Kim, Jenny J; Faraj, Sheila F; Chaux, Alcides; Bezerra, Stephania M; Munari, Enrico; Ellis, Carla; Sharma, Rajni; Keizman, Daniel; Bivalacqua, Trinity J; Schoenberg, Mark; Eisenberger, Mario; Carducci, Michael; Netto, George J

    2014-06-01

    To assess the insulin-like growth factor-1 receptor (IGF1R) expression in urothelial carcinoma (UC) and its prognostic role in relation to clinicopathologic parameters. A total of 100 cases of invasive UC were evaluated using tissue microarrays. Membranous IGF1R staining was evaluated using immunohistochemistry. A scoring method analogous to that of HER2 expression in breast carcinoma was used, and the highest score was assigned in each tumor. IGF1R was considered overexpressed in cases with score≥1. We found IGF1R overexpression in 62% of invasive UC. IGF1R overexpression was associated with race (P=.04) and pT category (P=.03). Median follow-up was 29 months (range, 0.5-212). Progression rate was 60%, and overall mortality and cancer-specific mortality rates were 69% and 51%, respectively. In invasive UC, IGF1R overexpression was significantly associated with overall mortality and cancer-specific mortality (Mantel Cox P=.0002 and P=.006, respectively). IGF1R overexpression was associated with increased hazard ratios (HRs) for overall mortality (HR=2.63, P=.001) and cancer-specific mortality (HR=2.45, P=.01), independently and after adjusting for clinicopathologic features and treatment modalities. We found IGF1R overexpression in 62% of bladder UC. More importantly, IGF1R overexpression was a significant predictor of overall mortality and cancer-specific mortality, suggesting its potential role as a prognosticator in UC of bladder. Copyright © 2014 Elsevier Inc. All rights reserved.

  15. TAM receptor signaling in development.

    Science.gov (United States)

    Burstyn-Cohen, Tal

    2017-01-01

    TYRO3, AXL and MERTK comprise the TAM family of receptor protein tyrosine kinases. Activated by their ligands, protein S (PROS1) and growth-arrest-specific 6 (GAS6), they mediate numerous cellular functions throughout development and adulthood. Expressed by a myriad of cell types and tissues, they have been implicated in homeostatic regulation of the immune, nervous, vascular, bone and reproductive systems. The loss-of-function of TAM signaling in adult tissues culminates in the destruction of tissue homeostasis and diseased states, while TAM gain-of-function in various tumors promotes cancer phenotypes. Combinatorial ligand-receptor interactions may elicit different molecular and cellular responses. Many of the TAM regulatory functions are essentially developmental, taking place both during embryogenesis and postnatally. This review highlights current knowledge on the role of TAM receptors and their ligands during these developmental processes in the immune, nervous, vascular and reproductive systems.

  16. Long-pulse gastric electrical stimulation protects interstitial cells of Cajal in diabetic rats via IGF-1 signaling pathway.

    Science.gov (United States)

    Li, Hai; Chen, Yan; Liu, Shi; Hou, Xiao-Hua

    2016-06-21

    To investigate the effects of different parameters of gastric electrical stimulation (GES) on interstitial cells of Cajal (ICCs) and changes in the insulin-like growth factor 1 (IGF-1) signal pathway in streptozotocin-induced diabetic rats. Male rats were randomized into control, diabetic (DM), diabetic with sham GES (DM + SGES), diabetic with GES1 (5.5 cpm, 100 ms, 4 mA) (DM + GES1), diabetic with GES2 (5.5 cpm, 300 ms, 4 mA) (DM + GES2) and diabetic with GES3 (5.5 cpm, 550 ms, 2 mA) (DM + GES3) groups. The expression levels of c-kit, M-SCF and IGF-1 receptors were evaluated in the gastric antrum using Western blot analysis. The distribution of ICCs was observed using immunolabeling for c-kit, while smooth muscle cells and IGF-1 receptors were identified using α-SMA and IGF-1R antibodies. Serum level of IGF-1 was tested using enzyme-linked immunosorbent assay. Gastric emptying was delayed in the DM group but improved in all GES groups, especially in the GES2 group. The expression levels of c-kit, M-SCF and IGF-1R were decreased in the DM group but increased in all GES groups. More ICCs (c-kit(+)) and smooth muscle cells (α-SMA(+)/IGF-1R(+)) were observed in all GES groups than in the DM group. The average level of IGF-1 in the DM group was markedly decreased, but it was up-regulated in all GES groups, especially in the GES2 group. The results suggest that long-pulse GES promotes the regeneration of ICCs. The IGF-1 signaling pathway might be involved in the mechanism underlying this process, which results in improved gastric emptying.

  17. Plasma and tissue insulin-like growth factor-I receptor (IGF-IR) as a prognostic marker for prostate cancer and anti-IGF-IR agents as novel therapeutic strategy for refractory cases: a review.

    Science.gov (United States)

    Ozkan, Emine Elif

    2011-09-15

    Cancer database analysis indicates that prostate cancer is one of the most seen cancers in men meanwhile composing the leading cause of morbidity and mortality among developed countries. Current available therapies are surgery, radiotherapy and androgene ablation for prostate carcinoma. The response rate is as high nearly 90% however, most of these recur or become refractory and androgene independent (AI). Therefore recent studies intensified on molecular factors playing role on development of prostate carcinoma and novel treatment strategies targetting these factors and their receptors. Insulin-like growth factor-I (IGF-I) and its primary receptor insulin-like growth factor receptor-I (IGF-IR) are among these factors. Biologic functions and role in malign progression are primarily achieved via IGF-IR which is a type 2 tyrosine kinase receptor. IGF-IR plays an important role in mitogenesis, angiogenesis, transformation, apoptosis and cell motility. It also generates intensive proliferative signals leading to carcinogenesis in prostate tissue. So IGF-IR and its associated signalling system have provoked considerable interest over recent years as a novel therapeutic target in cancer. In this paper it is aimed to sum up the lately published literature searching the relation of IGF-IR and prostate cancer in terms of incidence, pathologic features, and prognosis. This is followed by a discussion of the different possible targets within the IGF-1R system, and drugs developed to interact at each target. A systems-based approach is then used to review the in vitro and in vivo data in the published literature of the following compounds targeting IGF-1R components using specific examples: growth hormone releasing hormone antagonists (e.g. JV-1-38), growth hormone receptor antagonists (e.g. pegvisomant), IGF-1R antibodies (e.g. CP-751,871, AVE1642/EM164, IMC-A12, SCH-717454, BIIB022, AMG 479, MK-0646/h7C10), and IGF-1R tyrosine kinase inhibitors (e.g. BMS-536942, BMS-554417

  18. Effects of insulin analogs and glucagon-like peptide-1 receptor agonists on proliferation and cellular energy metabolism in papillary thyroid cancer

    Directory of Open Access Journals (Sweden)

    He L

    2017-11-01

    Full Text Available Liang He,1,* Siliang Zhang,2,* Xiaowen Zhang,3 Rui Liu,2 Haixia Guan,2 Hao Zhang1 1Department of Thyroid Surgery, The First Hospital of China Medical University, Shenyang, Liaoning, 2Department of Endocrinology and Metabolism, The Endocrine Institute and The Liaoning Provincial Key Laboratory of Endocrine Diseases, The First Hospital of China Medical University, Shenyang, Liaoning, 3Department of Endocrinology and Metabolism, Drum Tower Hospital Affiliated to Nanjing University Medical School, Nanjing, People’s Republic of China *These authors contributed equally to this work Purpose: This study was aimed to investigate the expressions of the insulin receptor (IR, insulin-like growth factor receptor (IGF-1R, and glucagon-like peptide-1 receptor (GLP-1R in normal thyroid tissue, papillary thyroid cancer (PTC tissues, and PTC cells, and to examine the possible role of insulin analogs and GLP-1R agonists in cell proliferation and energy metabolism in PTC cells.Methods: The expressions of IR, IGF-1R, and GLP-1R in PTC tissues and PTC cell lines were detected by immunohistochemistry and western blotting, respectively. Cell proliferation was evaluated by the 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide assay. Levels of members of the phosphoinositol-3 kinase/AKT serine/threonine kinase (Akt and mitogen-activated protein kinase/extracellular signal-regulated kinase (Erk signaling pathways were measured by western blotting. Energy metabolism of PTC cell lines was analyzed using a Seahorse Extracellular Flux analyzer.Results: Three receptors could be detected in both PTC tissues and PTC cell lines. Expressions of IGF-1R and GLP-1R were more obvious in PTC than in normal thyroid cells. Neither insulin, four insulin analogs, and two GLP-1R agonists showed significant effects on the proliferation of PTC cells, nor did they influence the levels of Akt/p-Akt and Erk/p-Erk. None of these antidiabetic agents could change the mitochondrial

  19. miR-630 targets IGF1R to regulate response to HER-targeting drugs and overall cancer cell progression in HER2 over-expressing breast cancer.

    Science.gov (United States)

    Corcoran, Claire; Rani, Sweta; Breslin, Susan; Gogarty, Martina; Ghobrial, Irene M; Crown, John; O'Driscoll, Lorraine

    2014-03-24

    While the treatment of HER2 over-expressing breast cancer with recent HER-targeted drugs has been highly effective for some patients, primary (also known as innate) or acquired resistance limits the success of these drugs. microRNAs have potential as diagnostic, prognostic and predictive biomarkers, as well as replacement therapies. Here we investigated the role of microRNA-630 (miR-630) in breast cancer progression and as a predictive biomarker for response to HER-targeting drugs, ultimately yielding potential as a therapeutic approach to add value to these drugs. We investigated the levels of intra- and extracellular miR-630 in cells and conditioned media from breast cancer cell lines with either innate- or acquired- resistance to HER-targeting lapatinib and neratinib, compared to their corresponding drug sensitive cell lines, using qPCR. To support the role of miR-630 in breast cancer, we examined the clinical relevance of this miRNA in breast cancer tumours versus matched peritumours. Transfection of miR-630 mimics and inhibitors was used to manipulate the expression of miR-630 to assess effects on response to HER-targeting drugs (lapatinib, neratinib and afatinib). Other phenotypic changes associated with cellular aggressiveness were evaluated by motility, invasion and anoikis assays. TargetScan prediction software, qPCR, immunoblotting and ELISAs, were used to assess miR-630's regulation of mRNA, proteins and their phosphorylated forms. We established that introducing miR-630 into cells with innate- or acquired- resistance to HER-drugs significantly restored the efficacy of lapatinib, neratinib and afatinib; through a mechanism which we have determined to, at least partly, involve miR-630's regulation of IGF1R. Conversely, we demonstrated that blocking miR-630 induced resistance/insensitivity to these drugs. Cellular motility, invasion, and anoikis were also observed as significantly altered by miR-630 manipulation, whereby introducing miR-630 into cells

  20. Unique expression pattern of the three insulin receptor family members in the rat mammary gland

    DEFF Research Database (Denmark)

    Hvid, Henning; Klopfleisch, Robert; Vienberg, Sara Gry

    2011-01-01

    mammary gland. Using laser micro-dissection, quantitative RT-PCR and immunohistochemistry, we examined the expression of IR (insulin receptor), IGF-1R (IGF-1 receptor), IRR (insulin receptor-related receptor), ERα (estrogen receptor alpha), ERβ (estrogen receptor beta) and PR (progesteron receptor......) in young, virgin, female Sprague-Dawley rats and compared to expression in reference organs. The mammary gland displayed the highest expression of IRR and IGF-1R. In contrast, low expression of IR transcripts was observed in the mammary gland tissue with expression of the IR-A isoform being 5-fold higher...... than the expression of the IR-B. By immunohistochemistry, expression of IR and IGF-1R was detected in all mammary gland epithelial cells. Expression of ERα and PR was comparable between mammary gland and ovary, whereas expression of ERβ was lower in mammary gland than in the ovary. Finally, expression...

  1. Targeting the Insulin-Like Growth Factor 1 Receptor in Ewing's Sarcoma: Reality and Expectations

    Directory of Open Access Journals (Sweden)

    David Olmos

    2011-01-01

    Full Text Available Ewing's sarcoma family of tumours comprises a group of very aggressive diseases that are potentially curable with multimodality treatment. Despite the undoubted success of current treatment, approximately 30% of patients will relapse and ultimately die of disease. The insulin-like growth factor 1 receptor (IGF-1R has been implicated in the genesis, growth, proliferation, and the development of metastatic disease in Ewing's sarcoma. In addition, IGF1-R has been validated, both in vitro and in vivo, as a potential therapeutic target in Ewing's sarcoma. Phase I studies of IGF-1R monoclonal antibodies reported several radiological and clinical responses in Ewing's sarcoma patients, and initial reports of several Phase II studies suggest that about a fourth of the patients would benefit from IGF-1R monoclonal antibodies as single therapy, with approximately 10% of patients achieving objective responses. Furthermore, these therapies are well tolerated, and thus far severe toxicity has been rare. Other studies assessing IGF-1R monoclonal antibodies in combination with traditional cytotoxics or other targeted therapies are expected. Despite, the initial promising results, not all patients benefit from IGF-1R inhibition, and consequently, there is an urgent need for the identification of predictive markers of response.

  2. Targeting the Insulin-Like Growth Factor 1 Receptor in Ewing's Sarcoma: Reality and Expectations

    Science.gov (United States)

    Olmos, David; Martins, Ana Sofia; Jones, Robin L.; Alam, Salma; Scurr, Michelle; Judson, Ian R.

    2011-01-01

    Ewing's sarcoma family of tumours comprises a group of very aggressive diseases that are potentially curable with multimodality treatment. Despite the undoubted success of current treatment, approximately 30% of patients will relapse and ultimately die of disease. The insulin-like growth factor 1 receptor (IGF-1R) has been implicated in the genesis, growth, proliferation, and the development of metastatic disease in Ewing's sarcoma. In addition, IGF1-R has been validated, both in vitro and in vivo, as a potential therapeutic target in Ewing's sarcoma. Phase I studies of IGF-1R monoclonal antibodies reported several radiological and clinical responses in Ewing's sarcoma patients, and initial reports of several Phase II studies suggest that about a fourth of the patients would benefit from IGF-1R monoclonal antibodies as single therapy, with approximately 10% of patients achieving objective responses. Furthermore, these therapies are well tolerated, and thus far severe toxicity has been rare. Other studies assessing IGF-1R monoclonal antibodies in combination with traditional cytotoxics or other targeted therapies are expected. Despite, the initial promising results, not all patients benefit from IGF-1R inhibition, and consequently, there is an urgent need for the identification of predictive markers of response. PMID:21647361

  3. Interaction of single nucleotide polymorphisms in ADRB2, ADRB3, TNF, IL6, IGF1R, LIPC, LEPR, and GHRL with physical activity on the risk of type 2 diabetes mellitus and changes in characteristics of the metabolic syndrome

    DEFF Research Database (Denmark)

    Oskari Kilpeläinen, Tuomas; Lakka, Timo A; Laaksonen, David E

    2008-01-01

    Single nucleotide polymorphisms (SNPs) in the ADRB2, ADRB3, TNF, IL6, IGF1R, LIPC, LEPR, and GHRL genes were associated with the conversion from impaired glucose tolerance (IGT) to type 2 diabetes mellitus (T2D) in the Finnish Diabetes Prevention Study (DPS). In this study, we determined whether...... on the conversion to T2D was found. The Leu72Met (rs696217) polymorphism in GHRL modified the effect of moderate-to-vigorous PA on changes in weight and waist circumference, the -501A/C (rs26802) polymorphism in GHRL modified the effect of total and moderate-to-vigorous PA on change in high-density lipoprotein...... polymorphisms in these genes modified the effect of changes in physical activity (PA) on the risk of T2D in the DPS. Moreover, we assessed whether the polymorphisms modified the effect of changes in PA on changes in measures of body fat, serum lipids, and blood pressure during the first year of the follow...

  4. 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.

  5. MicroRNA-99a inhibits insulin-induced proliferation, migration, dedifferentiation, and rapamycin resistance of vascular smooth muscle cells by inhibiting insulin-like growth factor-1 receptor and mammalian target of rapamycin

    International Nuclear Information System (INIS)

    Zhang, Zi-wei; Guo, Rui-wei; Lv, Jin-lin; Wang, Xian-mei; Ye, Jin-shan; Lu, Ni-hong; Liang, Xing; Yang, Li-xia

    2017-01-01

    Patients with type 2 diabetes mellitus (T2DM) are characterized by insulin resistance and are subsequently at high risk for atherosclerosis. Hyperinsulinemia has been associated with proliferation, migration, and dedifferentiation of vascular smooth muscle cells (VSMCs) during the pathogenesis of atherosclerosis. Moreover, insulin-like growth factor-1 receptor (IGF-1R) and mammalian target of rapamycin (mTOR) have been demonstrated to be the underlying signaling pathways. Recently, microRNA-99a (miR-99a) has been suggested to regulate the phenotypic changes of VSMCs in cancer cells. However, whether it is involved in insulin-induced changes of VSCMs has not been determined. In this study, we found that insulin induced proliferation, migration, and dedifferentiation of mouse VSMCs in a dose-dependent manner. Furthermore, the stimulating effects of high-dose insulin on proliferation, migration, and dedifferentiation of mouse VSMCs were found to be associated with the attenuation of the inhibitory effects of miR-99a on IGF-1R and mTOR signaling activities. Finally, we found that the inducing effect of high-dose insulin on proliferation, migration, and dedifferentiation of VSMCs was partially inhibited by an active mimic of miR-99a. Taken together, these results suggest that miR-99a plays a key regulatory role in the pathogenesis of insulin-induced proliferation, migration, and phenotype conversion of VSMCs at least partly via inhibition of IGF-1R and mTOR signaling. Our results provide evidence that miR-99a may be a novel target for the treatment of hyperinsulinemia-induced atherosclerosis. - Highlights: • Suggesting a new mechanism of insulin-triggered VSMC functions. • Providing a new therapeutic strategies that target atherosclerosis in T2DM patients. • Providing a new strategies that target in-stent restenosis in T2DM patients.

  6. Regulation of the insulin-Akt signaling pathway and glycolysis during dehydration stress in the African clawed frog Xenopus laevis.

    Science.gov (United States)

    Wu, Cheng-Wei; Tessier, Shannon N; Storey, Kenneth B

    2017-12-01

    Estivation is an adaptive stress response utilized by some amphibians during periods of drought in the summer season. In this study, we examine the regulation of the insulin signaling cascade and glycolysis pathway in the African clawed frog Xenopus laevis during the dehydration stress induced state of estivation. We show that in the brain and heart of X. laevis, dehydration reduces the phosphorylation of the insulin growth factor-1 receptor (IGF-1R), and this is followed by similar reductions in the phosphorylation of the Akt and mechanistic target of rapamycin (mTOR) kinase. Interestingly, phosphorylation levels of IGF-1R and mTOR were not affected in the kidney, and phosphorylation levels of P70S6K and the ribosomal S6 protein were elevated during dehydration stress. Animals under estivation are also susceptible to periods of hypoxia, suggesting that glycolysis may also be affected. We observed that protein levels of many glycolytic enzymes remained unchanged during dehydration; however, the hypoxia response factor-1 alpha (HIF-1α) protein was elevated by greater than twofold in the heart during dehydration. Overall, we provide evidence that shows that the insulin signaling pathway in X. laevis is regulated in a tissue-specific manner during dehydration stress and suggests an important role for this signaling cascade in mediating the estivation response.

  7. Androgen Receptor Signaling in Bladder Cancer

    OpenAIRE

    Li, Peng; Chen, Jinbo; Miyamoto, Hiroshi

    2017-01-01

    Emerging preclinical findings have indicated that steroid hormone receptor signaling plays an important role in bladder cancer outgrowth. In particular, androgen-mediated androgen receptor signals have been shown to correlate with the promotion of tumor development and progression, which may clearly explain some sex-specific differences in bladder cancer. This review summarizes and discusses the available data, suggesting the involvement of androgens and/or the androgen receptor pathways in u...

  8. The interleukin-4 receptor: signal transduction by a hematopoietin receptor.

    Science.gov (United States)

    Keegan, A D; Pierce, J H

    1994-02-01

    Over the last several years, the receptors for numerous cytokines have been molecularly characterized. Analysis of their amino acid sequences shows that some of these receptors bear certain motifs in their extracellular domains that define a family of receptors called the Hematopoietin receptor superfamily. Significant advances in characterizing the structure, function, and mechanisms of signal transduction have been made for several members of this family. The purpose of this review is to discuss the recent advances made for one of the family members, the interleukin (IL) 4 receptor. Other receptor systems have recently been reviewed elsewhere. The IL-4 receptor consists of, at the minimum, the cloned 140 kDa IL-4-binding chain with the potential for associating with other chains. The IL-4 receptor transduces its signal by activating a tyrosine kinase that phosphorylates cellular substrates, including the receptor itself, and the 170 kDa substrate called 4PS. Phosphorylated 4PS interacts with the SH2 domain of the enzyme PI-3'-kinase and increases its enzymatic activity. These early events in the IL-4 receptor initiated signaling pathway may trigger a series of signals that will ultimately lead to an IL-4 specific biologic outcome.

  9. IGF-1-induced MMP-11 expression promotes the proliferation and invasion of gastric cancer cells through the JAK1/STAT3 signaling pathway.

    Science.gov (United States)

    Su, Chao; Wang, Wenchang; Wang, Cunchuan

    2018-05-01

    The present study aimed to investigate the association between insulin-like growth factor-1 (IGF-1) and matrix metalloproteinase-11 (MMP-11) expression in gastric cancer (GC) and the underlying mechanisms in SGC-7901 cells. Reverse transcription-quantitative polymerase chain reaction analysis revealed that the expression of IGF-1 and MMP-11 was significantly upregulated in GC tissues compared with normal gastric tissue. Furthermore, IGF-1 significantly and dose-dependently promoted MMP-11. Western blotting revealed that the addition of IGF-1 to SGC-7901 cells led to an evident enhancement in signal transducer and activator of transcription 3 (STAT3), IGF-1R and Janus kinase 1 (JAK1) phosphorylation at 20 and 40 min. A decrease in the extent of the elevated expression of MMP-11 and the enhanced phosphorylation of STAT3, JAK1 and IGF-1 receptor (IGF-1R) induced by IGF-1 in SGC-7901 cells were observed following treatment with NT157 (an IGF-1R inhibitor). Furthermore, piceatannol (a JAK1 inhibitor) or small interfering RNA against STAT3 reduced the extent of the increased expression of MMP-11 induced by IGF-1 in SGC-7901 cells. Piceatannol treatment induced the dose-dependent decline in the enhancement of STAT3 phosphorylation induced by IGF-1, indicating that the JAK1/STAT3 pathway may be implicated in the elevated expression of MMP-11 induced by IGF-1 in SGC-7901 cells. Finally, IGF-1 treatment significantly promoted the proliferation and invasion of SGC-7901 cells, which was inhibited following NT157, piceatannol or si-STAT3 treatment. The present study therefore demonstrated that IGF-1-induced MMP-11 may have facilitated the proliferation and invasion of SGC-7901 cells via the JAK1/STAT3 pathway.

  10. Clinical and functional characterization of a patient carrying a compound heterozygous pericentrin mutation and a heterozygous IGF1 receptor mutation.

    Directory of Open Access Journals (Sweden)

    Eva Müller

    Full Text Available Intrauterine and postnatal longitudinal growth is controlled by a strong genetic component that regulates a complex network of endocrine factors integrating them with cellular proliferation, differentiation and apoptotic processes in target tissues, particularly the growth centers of the long bones. Here we report on a patient born small for gestational age (SGA with severe, proportionate postnatal growth retardation, discreet signs of skeletal dysplasia, microcephaly and moyamoya disease. Initial genetic evaluation revealed a novel heterozygous IGF1R p.Leu1361Arg mutation affecting a highly conserved residue with the insulin-like growth factor type 1 receptor suggestive for a disturbance within the somatotropic axis. However, because the mutation did not co-segregate with the phenotype and functional characterization did not reveal an obvious impairment of the ligand depending major IGF1R signaling capabilities a second-site mutation was assumed. Mutational screening of components of the somatotropic axis, constituents of the IGF signaling system and factors involved in cellular proliferation, which are described or suggested to provoke syndromic dwarfism phenotypes, was performed. Two compound heterozygous PCNT mutations (p.[Arg585X];[Glu1774X] were identified leading to the specification of the diagnosis to MOPD II. These investigations underline the need for careful assessment of all available information to derive a firm diagnosis from a sequence aberration.

  11. Clinical and functional characterization of a patient carrying a compound heterozygous pericentrin mutation and a heterozygous IGF1 receptor mutation.

    Science.gov (United States)

    Müller, Eva; Dunstheimer, Desiree; Klammt, Jürgen; Friebe, Daniela; Kiess, Wieland; Kratzsch, Jürgen; Kruis, Tassilo; Laue, Sandy; Pfäffle, Roland; Wallborn, Tillmann; Heidemann, Peter H

    2012-01-01

    Intrauterine and postnatal longitudinal growth is controlled by a strong genetic component that regulates a complex network of endocrine factors integrating them with cellular proliferation, differentiation and apoptotic processes in target tissues, particularly the growth centers of the long bones. Here we report on a patient born small for gestational age (SGA) with severe, proportionate postnatal growth retardation, discreet signs of skeletal dysplasia, microcephaly and moyamoya disease. Initial genetic evaluation revealed a novel heterozygous IGF1R p.Leu1361Arg mutation affecting a highly conserved residue with the insulin-like growth factor type 1 receptor suggestive for a disturbance within the somatotropic axis. However, because the mutation did not co-segregate with the phenotype and functional characterization did not reveal an obvious impairment of the ligand depending major IGF1R signaling capabilities a second-site mutation was assumed. Mutational screening of components of the somatotropic axis, constituents of the IGF signaling system and factors involved in cellular proliferation, which are described or suggested to provoke syndromic dwarfism phenotypes, was performed. Two compound heterozygous PCNT mutations (p.[Arg585X];[Glu1774X]) were identified leading to the specification of the diagnosis to MOPD II. These investigations underline the need for careful assessment of all available information to derive a firm diagnosis from a sequence aberration.

  12. Muscarinic Receptor Signaling in Colon Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Rosenvinge, Erik C. von, E-mail: evonrose@medicine.umaryland.edu; Raufman, Jean-Pierre [University of Maryland School of Medicine, Division of Gastroenterology & Hepatology, 22 S. Greene Street, N3W62, Baltimore, MD 21201 (United States); Department of Veterans Affairs, VA Maryland Health Care System, 10 North Greene Street, Baltimore, MD 21201 (United States)

    2011-03-02

    According to the adenoma-carcinoma sequence, colon cancer results from accumulating somatic gene mutations; environmental growth factors accelerate and augment this process. For example, diets rich in meat and fat increase fecal bile acids and colon cancer risk. In rodent cancer models, increased fecal bile acids promote colon dysplasia. Conversely, in rodents and in persons with inflammatory bowel disease, low-dose ursodeoxycholic acid treatment alters fecal bile acid composition and attenuates colon neoplasia. In the course of elucidating the mechanism underlying these actions, we discovered that bile acids interact functionally with intestinal muscarinic receptors. The present communication reviews muscarinic receptor expression in normal and neoplastic colon epithelium, the role of autocrine signaling following synthesis and release of acetylcholine from colon cancer cells, post-muscarinic receptor signaling including the role of transactivation of epidermal growth factor receptors and activation of the ERK and PI3K/AKT signaling pathways, the structural biology and metabolism of bile acids and evidence for functional interaction of bile acids with muscarinic receptors on human colon cancer cells. In murine colon cancer models, deficiency of subtype 3 muscarinic receptors attenuates intestinal neoplasia; a proof-of-concept supporting muscarinic receptor signaling as a therapeutic target for colon cancer.

  13. Muscarinic Receptor Signaling in Colon Cancer

    International Nuclear Information System (INIS)

    Rosenvinge, Erik C. von; Raufman, Jean-Pierre

    2011-01-01

    According to the adenoma-carcinoma sequence, colon cancer results from accumulating somatic gene mutations; environmental growth factors accelerate and augment this process. For example, diets rich in meat and fat increase fecal bile acids and colon cancer risk. In rodent cancer models, increased fecal bile acids promote colon dysplasia. Conversely, in rodents and in persons with inflammatory bowel disease, low-dose ursodeoxycholic acid treatment alters fecal bile acid composition and attenuates colon neoplasia. In the course of elucidating the mechanism underlying these actions, we discovered that bile acids interact functionally with intestinal muscarinic receptors. The present communication reviews muscarinic receptor expression in normal and neoplastic colon epithelium, the role of autocrine signaling following synthesis and release of acetylcholine from colon cancer cells, post-muscarinic receptor signaling including the role of transactivation of epidermal growth factor receptors and activation of the ERK and PI3K/AKT signaling pathways, the structural biology and metabolism of bile acids and evidence for functional interaction of bile acids with muscarinic receptors on human colon cancer cells. In murine colon cancer models, deficiency of subtype 3 muscarinic receptors attenuates intestinal neoplasia; a proof-of-concept supporting muscarinic receptor signaling as a therapeutic target for colon cancer

  14. Muscarinic Receptor Signaling in Colon Cancer

    Directory of Open Access Journals (Sweden)

    Jean-Pierre Raufman

    2011-03-01

    Full Text Available According to the adenoma-carcinoma sequence, colon cancer results from accumulating somatic gene mutations; environmental growth factors accelerate and augment this process. For example, diets rich in meat and fat increase fecal bile acids and colon cancer risk. In rodent cancer models, increased fecal bile acids promote colon dysplasia. Conversely, in rodents and in persons with inflammatory bowel disease, low-dose ursodeoxycholic acid treatment alters fecal bile acid composition and attenuates colon neoplasia. In the course of elucidating the mechanism underlying these actions, we discovered that bile acids interact functionally with intestinal muscarinic receptors. The present communication reviews muscarinic receptor expression in normal and neoplastic colon epithelium, the role of autocrine signaling following synthesis and release of acetylcholine from colon cancer cells, post-muscarinic receptor signaling including the role of transactivation of epidermal growth factor receptors and activation of the ERK and PI3K/AKT signaling pathways, the structural biology and metabolism of bile acids and evidence for functional interaction of bile acids with muscarinic receptors on human colon cancer cells. In murine colon cancer models, deficiency of subtype 3 muscarinic receptors attenuates intestinal neoplasia; a proof-of-concept supporting muscarinic receptor signaling as a therapeutic target for colon cancer.

  15. Probing Biased Signaling in Chemokine Receptors

    DEFF Research Database (Denmark)

    Amarandi, Roxana Maria; Hjortø, Gertrud Malene; Rosenkilde, Mette Marie

    2016-01-01

    The chemokine system mediates leukocyte migration during homeostatic and inflammatory processes. Traditionally, it is described as redundant and promiscuous, with a single chemokine ligand binding to different receptors and a single receptor having several ligands. Signaling of chemokine receptors...... of others has been termed signaling bias and can accordingly be grouped into ligand bias, receptor bias, and tissue bias. Bias has so far been broadly overlooked in the process of drug development. The low number of currently approved drugs targeting the chemokine system, as well as the broad range...... of failed clinical trials, reflects the need for a better understanding of the chemokine system. Thus, understanding the character, direction, and consequence of biased signaling in the chemokine system may aid the development of new therapeutics. This review describes experiments to assess G protein...

  16. Erythropoietin Receptor Signaling Is Membrane Raft Dependent

    Science.gov (United States)

    McGraw, Kathy L.; Fuhler, Gwenny M.; Johnson, Joseph O.; Clark, Justine A.; Caceres, Gisela C.; Sokol, Lubomir; List, Alan F.

    2012-01-01

    Upon erythropoietin (Epo) engagement, Epo-receptor (R) homodimerizes to activate JAK2 and Lyn, which phosphorylate STAT5. Although recent investigations have identified key negative regulators of Epo-R signaling, little is known about the role of membrane localization in controlling receptor signal fidelity. Here we show a critical role for membrane raft (MR) microdomains in creation of discrete signaling platforms essential for Epo-R signaling. Treatment of UT7 cells with Epo induced MR assembly and coalescence. Confocal microscopy showed that raft aggregates significantly increased after Epo stimulation (mean, 4.3±1.4(SE) vs. 25.6±3.2 aggregates/cell; p≤0.001), accompanied by a >3-fold increase in cluster size (p≤0.001). Raft fraction immunoblotting showed Epo-R translocation to MR after Epo stimulation and was confirmed by fluorescence microscopy in Epo stimulated UT7 cells and primary erythroid bursts. Receptor recruitment into MR was accompanied by incorporation of JAK2, Lyn, and STAT5 and their activated forms. Raft disruption by cholesterol depletion extinguished Epo induced Jak2, STAT5, Akt and MAPK phosphorylation in UT7 cells and erythroid progenitors. Furthermore, inhibition of the Rho GTPases Rac1 or RhoA blocked receptor recruitment into raft fractions, indicating a role for these GTPases in receptor trafficking. These data establish a critical role for MR in recruitment and assembly of Epo-R and signal intermediates into discrete membrane signaling units. PMID:22509308

  17. Glucocorticoid receptor signaling in health and disease

    Science.gov (United States)

    Kadmiel, Mahita; Cidlowski, John A.

    2013-01-01

    Glucocorticoids are steroid hormones regulated in a circadian and stres-associated manner to maintain various metabolic and homeostatic functions that are necessary for life. Synthetic glucocorticoids are widely prescribed drugs for many conditions including asthma, chronic obstructive pulmonary disease (COPD), and inflammatory disorders of the eye. Research in the last few years has begun to unravel the profound complexity of glucocorticoid signaling and has contributed remarkably to improved therapeutic strategies. Glucocorticoids signal through the glucocorticoid receptor, a member of the superfamily of nuclear receptors, in both genomic and non-genomic ways in almost every tissue in the human body. In this review, we will provide an update on glucocorticoid receptor signaling and highlight the role of GR signaling in physiological and pathophysiological conditions in the major organ systems in the human body. PMID:23953592

  18. Receptor tyrosine kinase signaling: a view from quantitative proteomics

    DEFF Research Database (Denmark)

    Dengjel, Joern; Kratchmarova, Irina; Blagoev, Blagoy

    2009-01-01

    Growth factor receptor signaling via receptor tyrosine kinases (RTKs) is one of the basic cellular communication principals found in all metazoans. Extracellular signals are transferred via membrane spanning receptors into the cytoplasm, reversible tyrosine phosphorylation being the hallmark of all...

  19. IGF1 Receptor Targeted Theranostic Nanoparticles for Targeted and Image-Guided Therapy of Pancreatic Cancer.

    Science.gov (United States)

    Zhou, Hongyu; Qian, Weiping; Uckun, Fatih M; Wang, Liya; Wang, Y Andrew; Chen, Hongyu; Kooby, David; Yu, Qian; Lipowska, Malgorzata; Staley, Charles A; Mao, Hui; Yang, Lily

    2015-08-25

    Overcoming resistance to chemotherapy is a major and unmet medical challenge in the treatment of pancreatic cancer. Poor drug delivery due to stromal barriers in the tumor microenvironment and aggressive tumor biology are additional impediments toward a more successful treatment of pancreatic cancer. In attempts to address these challenges, we developed IGF1 receptor (IGF1R)-directed, multifunctional theranostic nanoparticles for targeted delivery of therapeutic agents into IGF1R-expressing drug-resistant tumor cells and tumor-associated stromal cells. These nanoparticles were prepared by conjugating recombinant human IGF1 to magnetic iron oxide nanoparticles (IONPs) carrying the anthracycline doxorubicin (Dox) as the chemotherapeutic payload. Intravenously administered IGF1-IONPs exhibited excellent tumor targeting and penetration in an orthotopic patient-derived xenograft (PDX) model of pancreatic cancer featuring enriched tumor stroma and heterogeneous cancer cells. IGF1R-targeted therapy using the theranostic IGF1-IONP-Dox significantly inhibited the growth of pancreatic PDX tumors. The effects of the intratumoral nanoparticle delivery and therapeutic responses in the orthotopic pancreatic PDX tumors could be detected by magnetic resonance imaging (MRI) with IONP-induced contrasts. Histological analysis showed that IGF1R-targeted delivery of Dox significantly inhibited cell proliferation and induced apoptotic cell death of pancreatic cancer cells. Therefore, further development of IGF1R-targeted theranostic IONPs and MRI-guided cancer therapy as a precision nanomedicine may provide the basis for more effective treatment of pancreatic cancer.

  20. Expression of insulin-like growth factor-1 and insulin-like growth factor-1 receptors in EL4 lymphoma cells overexpressing growth hormone.

    Science.gov (United States)

    Weigent, Douglas A; Arnold, Robyn E

    2005-03-01

    Almost all of the previous studies with growth hormone (GH) have been done with exogenously supplied GH and, therefore, involve actions of the hormone through its receptor. However, the actions of endogenous or lymphocyte GH are still unclear. In a previous study, we showed that overexpression of GH (GHo) in a lymphoid cell line resulted in protection of the cells to apoptosis mediated by nitric oxide (NO). In the present study, we show that the protection from apoptosis could be transferred to control cells with culture fluids obtained from GHo cells and blocked by antibodies to the insulin-like growth factor-1 (IGF-1) or antibodies to the IGF-1-receptor (IGF-1R). Northern and Western blot analysis detected significantly higher levels of IGF-1 in cells overexpressing GH. An increase in the expression of the IGF-1R in GHo cells was also detected by Western blot analysis, (125)I-IGF-1 binding and analysis of IGF-1R promoter luciferase constructs. Transfection of GHo cells with a dominant negative IGF-1R mutant construct blocked the generation of NO and activation of Akt seen in GHo cells compared to vector alone control EL4 cells. The results suggest that one of the consequences of the overexpression of GH, in cells lacking the GH receptor, is an increase in the expression of IGF-1 and the IGF-1R which mediate the protection of EL4 lymphoma cells from apoptosis.

  1. Androgen Receptor Signaling in Bladder Cancer

    Science.gov (United States)

    Li, Peng; Chen, Jinbo; Miyamoto, Hiroshi

    2017-01-01

    Emerging preclinical findings have indicated that steroid hormone receptor signaling plays an important role in bladder cancer outgrowth. In particular, androgen-mediated androgen receptor signals have been shown to correlate with the promotion of tumor development and progression, which may clearly explain some sex-specific differences in bladder cancer. This review summarizes and discusses the available data, suggesting the involvement of androgens and/or the androgen receptor pathways in urothelial carcinogenesis as well as tumor growth. While the precise mechanisms of the functions of the androgen receptor in urothelial cells remain far from being fully understood, current evidence may offer chemopreventive or therapeutic options, using androgen deprivation therapy, in patients with bladder cancer. PMID:28241422

  2. Androgen Receptor Signaling in Bladder Cancer

    Directory of Open Access Journals (Sweden)

    Peng Li

    2017-02-01

    Full Text Available Emerging preclinical findings have indicated that steroid hormone receptor signaling plays an important role in bladder cancer outgrowth. In particular, androgen-mediated androgen receptor signals have been shown to correlate with the promotion of tumor development and progression, which may clearly explain some sex-specific differences in bladder cancer. This review summarizes and discusses the available data, suggesting the involvement of androgens and/or the androgen receptor pathways in urothelial carcinogenesis as well as tumor growth. While the precise mechanisms of the functions of the androgen receptor in urothelial cells remain far from being fully understood, current evidence may offer chemopreventive or therapeutic options, using androgen deprivation therapy, in patients with bladder cancer.

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

    DEFF Research Database (Denmark)

    Dengjel, Joern; Akimov, Vyacheslav; Blagoev, Blagoy

    2007-01-01

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

  4. Erythropoietin receptor signaling is membrane raft dependent

    NARCIS (Netherlands)

    K.L. McGraw (Kathy); G.M. Fuhler (Gwenny); J.O. Johnson (Joseph); J.A. Clark (Justine); G.C. Caceres (Gisela); L. Sokol (Lubomir); A.F. List (Alan)

    2012-01-01

    textabstractUpon erythropoietin (Epo) engagement, Epo-receptor (R) homodimerizes to activate JAK2 and Lyn, which phosphorylate STAT5. Although recent investigations have identified key negative regulators of Epo-R signaling, little is known about the role of membrane localization in controlling

  5. Synthetic ligands of the elastin receptor induce elastogenesis in human dermal fibroblasts via activation of their IGF-1 receptors.

    Science.gov (United States)

    Qa'aty, Nour; Vincent, Matthew; Wang, Yanting; Wang, Andrew; Mitts, Thomas F; Hinek, Aleksander

    2015-12-01

    We have previously reported that a mixture of peptides obtained after chemical or enzymatic degradation of bovine elastin, induced new elastogenesis in human skin. Now, we investigated the elastogenic potential of synthetic peptides mimicking the elastin-derived, VGVAPG sequence, IGVAPG sequence that we found in the rice bran, and a similar peptide, VGVTAG that we identified in the IGF-1-binding protein-1 (IGFBP-1). We now demonstrate that treatment with each of these xGVxxG peptides (recognizable by the anti-elastin antibody), up-regulated the levels of elastin-encoding mRNA, tropoelastin protein, and the deposition of new elastic fibers in cultures of human dermal fibroblasts and in cultured explants of human skin. Importantly, we found that such induction of new elastogenesis may involve two parallel signaling pathways triggered after activation of IGF-1 receptor. In the first one, the xGVxxG peptides interact with the cell surface elastin receptor, thereby causing the downstream activation of the c-Src kinase and a consequent cross-activation of the adjacent IGF-1R, even in the absence of its principal ligand. In the second pathway their hydrophobic association with the N-terminal domain (VGVTAG) of the serum-derived IGFBP-1 induces conformational changes of this IGF-1 chaperone allowing for the release of its cargo and a consequent ligand-specific phosphorylation of IGF-1R. We present a novel, clinically relevant mechanism in which products of partial degradation of dermal elastin may stimulate production of new elastic fibers by dermal fibroblasts. Our findings particularly encourage the use of biologically safe synthetic xGVxxG peptides for regeneration of the injured or aged human skin. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  6. Tobacco Smoke Exposure Impairs Brain Insulin/IGF Signaling: Potential Co-Factor Role in Neurodegeneration.

    Science.gov (United States)

    Deochand, Chetram; Tong, Ming; Agarwal, Amit R; Cadenas, Enrique; de la Monte, Suzanne M

    2016-01-01

    Human studies suggest tobacco smoking is a risk factor for cognitive impairment and neurodegeneration, including Alzheimer's disease (AD). However, experimental data linking tobacco smoke exposures to underlying mediators of neurodegeneration, including impairments in brain insulin and insulin-like growth factor (IGF) signaling in AD are lacking. This study tests the hypothesis that cigarette smoke (CS) exposures can impair brain insulin/IGF signaling and alter expression of AD-associated proteins. Adult male A/J mice were exposed to air for 8 weeks (A8), CS for 4 or 8 weeks (CS4, CS8), or CS8 followed by 2 weeks recovery (CS8+R). Gene expression was measured by qRT-PCR analysis and proteins were measured by multiplex bead-based or direct binding duplex ELISAs. CS exposure effects on insulin/IGF and insulin receptor substrate (IRS) proteins and phosphorylated proteins were striking compared with the mRNA. The main consequences of CS4 or CS8 exposures were to significantly reduce insulin R, IGF-1R, IRS-1, and tyrosine phosphorylated insulin R and IGF-1R proteins. Paradoxically, these effects were even greater in the CS8+R group. In addition, relative levels of S312-IRS-1, which inhibits downstream signaling, were increased in the CS4, CS8, and CS8+R groups. Correspondingly, CS and CS8+R exposures inhibited expression of proteins and phosphoproteins required for signaling through Akt, PRAS40, and/or p70S6K, increased AβPP-Aβ, and reduced ASPH protein, which is a target of insulin/IGF-1 signaling. Secondhand CS exposures caused molecular and biochemical abnormalities in brain that overlap with the findings in AD, and many of these effects were sustained or worsened despite short-term CS withdrawal.

  7. TAM Receptor Signaling in Immune Homeostasis

    Science.gov (United States)

    Rothlin, Carla V.; Carrera-Silva, Eugenio A.; Bosurgi, Lidia; Ghosh, Sourav

    2015-01-01

    The TAM receptor tyrosine kinases (RTKs)—TYRO3, AXL, and MERTK—together with their cognate agonists GAS6 and PROS1 play an essential role in the resolution of inflammation. Deficiencies in TAM signaling have been associated with chronic inflammatory and autoimmune diseases. Three processes regulated by TAM signaling may contribute, either independently or collectively, to immune homeostasis: the negative regulation of the innate immune response, the phagocytosis of apoptotic cells, and the restoration of vascular integrity. Recent studies have also revealed the function of TAMs in infectious diseases and cancer. Here, we review the important milestones in the discovery of these RTKs and their ligands and the studies that underscore the functional importance of this signaling pathway in physiological immune settings and disease. PMID:25594431

  8. Inositol trisphosphate receptor mediated spatiotemporal calcium signalling.

    Science.gov (United States)

    Miyazaki, S

    1995-04-01

    Spatiotemporal Ca2+ signalling in the cytoplasm is currently understood as an excitation phenomenon by analogy with electrical excitation in the plasma membrane. In many cell types, Ca2+ waves and Ca2+ oscillations are mediated by inositol 1,4,5-trisphosphate (IP3) receptor/Ca2+ channels in the endoplasmic reticulum membrane, with positive feedback between cytosolic Ca2+ and IP3-induced Ca2+ release creating a regenerative process. Remarkable advances have been made in the past year in the analysis of subcellular Ca2+ microdomains using confocal microscopy and of Ca2+ influx pathways that are functionally coupled to IP3-induced Ca2+ release. Ca2+ signals can be conveyed into the nucleus and mitochondria. Ca2+ entry from outside the cell allows repetitive Ca2+ release by providing Ca2+ to refill the endoplasmic reticulum stores, thus giving rise to frequency-encoded Ca2+ signals.

  9. Taste Receptor Signaling-- From Tongues to Lungs

    Science.gov (United States)

    Kinnamon, Sue C.

    2013-01-01

    Taste buds are the transducing endorgans of gustation. Each taste bud comprises 50–100 elongated cells, which extend from the basal lamina to the surface of the tongue, where their apical microvilli encounter taste stimuli in the oral cavity. Salts and acids utilize apically located ion channels for transduction, while bitter, sweet and umami (glutamate) stimuli utilize G protein coupled receptors (GPCRs) and second messenger signaling mechanisms. This review will focus on GPCR signaling mechanisms. Two classes of taste GPCRs have been identified, the T1Rs for sweet and umami (glutamate) stimuli, and the T2Rs for bitter stimuli. These low affinity GPCRs all couple to the same downstream signaling effectors that include Gβγ activation of PLCβ2, IP3-mediated release of Ca2+ from intracellular stores, and Ca2+-dependent activation of the monovalent selective cation channel, TrpM5. These events lead to membrane depolarization, action potentials, and release of ATP as a transmitter to activate gustatory afferents. The Gα subunit, α-gustducin, activates a phosphodiesterase to decrease intracellular cAMP levels, although the precise targets of cAMP have not been identified. With the molecular identification of the taste GPCRs, it has become clear that taste signaling is not limited to taste buds, but occurs in many cell types of the airways. These include solitary chemosensory cells, ciliated epithelial cells, and smooth muscle cells. Bitter receptors are most abundantly expressed in the airways, where they respond to irritating chemicals and promote protective airway reflexes, utilizing the same downstream signaling effectors as taste cells. PMID:21481196

  10. Sex differences and left-right asymmetries in expression of insulin and insulin-like growth factor-1 receptors in developing rat hippocampus.

    Science.gov (United States)

    Hami, Javad; Sadr-Nabavi, Ariane; Sankian, Mojtaba; Haghir, Hossein

    2012-04-01

    Sex differences and laterality of rat hippocampus with respect to insulin-like growth factor-1 receptor (IGF-1R) and insulin receptor (InsR) expression as two important contributors to/regulators of developmental and cognitive functions were examined using real-time PCR and western blot analysis at P0, P7 and P14. Expression of the IGF-1R gene was lowest at P0 in all studied hippocampi. In males, we found the highest expression at P7 in the right hippocampus, and at P14 in the left one. In contrast, the peaked IGF-1R expression occurred at P7 in female hippocampi independent of laterality. Hippocampal InsR expression in males decreased significantly between P0 and P7, followed by a marked upregulation at P14. Conversely, the expression of InsR in females peaked at P7 and then decreased again significantly at P14. We found significant interhemispheric differences in IGF-1R mRNA levels in both male and female hippocampi at different time points. In contrast, we only found significant interhemispheric differences in InsR mRNA expression in P14 male rats, with higher values in the left hippocampus. Interestingly, changes in mRNA expression and in protein levels followed the same developmental pattern, indicating that IGF-1R and InsR transcription is not subject to modulatory effects during the first two weeks of development. These findings indicate that there are prominent interhemispheric and sex differences in IGF-1R and InsR expression in the developing rat hippocampus, suggesting a probable mechanism for the control of gender and laterality differences in development and function of the hippocampus.

  11. Steroid Hormone Receptor Signals as Prognosticators for Urothelial Tumor

    Directory of Open Access Journals (Sweden)

    Hiroki Ide

    2015-01-01

    Full Text Available There is a substantial amount of preclinical or clinical evidence suggesting that steroid hormone receptor-mediated signals play a critical role in urothelial tumorigenesis and tumor progression. These receptors include androgen receptor, estrogen receptors, glucocorticoid receptor, progesterone receptor, vitamin D receptor, retinoid receptors, peroxisome proliferator-activated receptors, and others including orphan receptors. In particular, studies using urothelial cancer tissue specimens have demonstrated that elevated or reduced expression of these receptors as well as alterations of their upstream or downstream pathways correlates with patient outcomes. This review summarizes and discusses available data suggesting that steroid hormone receptors and related signals serve as biomarkers for urothelial carcinoma and are able to predict tumor recurrence or progression.

  12. Proliferative signaling initiated in ACTH receptors

    Directory of Open Access Journals (Sweden)

    C.F.P. Lotfi

    2000-10-01

    Full Text Available This article reviews recent results of studies aiming to elucidate modes of integrating signals initiated in ACTH receptors and FGF2 receptors, within the network system of signal transduction found in Y1 adrenocortical cells. These modes of signal integration should be central to the mechanisms underlying the regulation of the G0->G1->S transition in the adrenal cell cycle. FGF2 elicits a strong mitogenic response in G0/G1-arrested Y1 adrenocortical cells, that includes a rapid and transient activation of extracellular signal-regulated kinases-mitogen-activated protein kinases (ERK-MAPK (2 to 10 min, b transcription activation of c-fos, c-jun and c-myc genes (10 to 30 min, c induction of c-Fos and c-Myc proteins by 1 h and cyclin D1 protein by 5 h, and d onset of DNA synthesis stimulation within 8 h. ACTH, itself a weak mitogen, interacts with FGF2 in a complex manner, blocking the FGF2 mitogenic response during the early and middle G1 phase, keeping ERK-MAPK activation and c-Fos and cyclin D1 induction at maximal levels, but post-transcriptionally inhibiting c-Myc expression. c-Fos and c-Jun proteins are mediators in both the strong and the weak mitogenic responses respectively triggered by FGF2 and ACTH. Induction of c-Fos and stimulation of DNA synthesis by ACTH are independent of PKA and are inhibited by the PKC inhibitor GF109203X. In addition, ACTH is a poor activator of ERK-MAPK, but c-Fos induction and DNA synthesis stimulation by ACTH are strongly inhibited by the inhibitor of MEK1 PD98059.

  13. Antibody-based therapeutics against components of the IGF system

    OpenAIRE

    Feng, Yang; Dimitrov, Dimiter S.

    2012-01-01

    The insulin-like growth factor I (IGF-I) receptor (IGF-1R) is overexpressed in most human neoplasms tested so far. Many tumors in young patients produce high levels of the IGF-1R ligands, IGF-I and IGF-II. Given the complexity of the IGF signaling pathway, its complete inhibition may require combination therapies with antibodies targeting both IGF-1R and IGF-II.

  14. Activation of IGF-1 and insulin signaling pathways ameliorate mitochondrial function and energy metabolism in Huntington's Disease human lymphoblasts.

    Science.gov (United States)

    Naia, Luana; Ferreira, I Luísa; Cunha-Oliveira, Teresa; Duarte, Ana I; Ribeiro, Márcio; Rosenstock, Tatiana R; Laço, Mário N; Ribeiro, Maria J; Oliveira, Catarina R; Saudou, Frédéric; Humbert, Sandrine; Rego, A Cristina

    2015-02-01

    Huntington's disease (HD) is an inherited neurodegenerative disease caused by a polyglutamine repeat expansion in the huntingtin protein. Mitochondrial dysfunction associated with energy failure plays an important role in this untreated pathology. In the present work, we used lymphoblasts obtained from HD patients or unaffected parentally related individuals to study the protective role of insulin-like growth factor 1 (IGF-1) versus insulin (at low nM) on signaling and metabolic and mitochondrial functions. Deregulation of intracellular signaling pathways linked to activation of insulin and IGF-1 receptors (IR,IGF-1R), Akt, and ERK was largely restored by IGF-1 and, at a less extent, by insulin in HD human lymphoblasts. Importantly, both neurotrophic factors stimulated huntingtin phosphorylation at Ser421 in HD cells. IGF-1 and insulin also rescued energy levels in HD peripheral cells, as evaluated by increased ATP and phosphocreatine, and decreased lactate levels. Moreover, IGF-1 effectively ameliorated O2 consumption and mitochondrial membrane potential (Δψm) in HD lymphoblasts, which occurred concomitantly with increased levels of cytochrome c. Indeed, constitutive phosphorylation of huntingtin was able to restore the Δψm in lymphoblasts expressing an abnormal expansion of polyglutamines. HD lymphoblasts further exhibited increased intracellular Ca(2+) levels before and after exposure to hydrogen peroxide (H2O2), and decreased mitochondrial Ca(2+) accumulation, being the later recovered by IGF-1 and insulin in HD lymphoblasts pre-exposed to H2O2. In summary, the data support an important role for IR/IGF-1R mediated activation of signaling pathways and improved mitochondrial and metabolic function in HD human lymphoblasts.

  15. Elevated IGFBP3 levels in diabetic tears: a negative regulator of IGF-1 signaling in the corneal epithelium.

    Science.gov (United States)

    Wu, Yu-Chieh; Buckner, Benjamin R; Zhu, Meifang; Cavanagh, H Dwight; Robertson, Danielle M

    2012-04-01

    To determine the ratio of IGFBP3:IGF-1 in normal and diabetic human tears, and in telomerase-immortalized human corneal epithelial cells (hTCEpi) cultured under elevated glucose conditions and to correlate these changes with total and phosphorylated levels of IGF-1R. Tear samples were collected noninvasively from diabetic subjects and non-diabetic controls; corneal sensitivity was assessed using a Cochet-Bonnet Aesthesiometer. Conditioned media were collected following culture of hTCEpi cells in normal (5 mM) and elevated (25 mM) glucose conditions; mannitol was used as an osmotic control. IGFBP3, IGF-1, and phosphorylated IGF-1R levels were assessed by ELISA. IGFBP3 and IGF-1R mRNA were assessed by real-time polymerase chain reaction (PCR). Total and phosphorylated IGF-1R expression in whole cell lysates was assessed by western blot. There was a 2.8-fold increase in IGFBP3 in diabetic tears compared to non-diabetic controls (P=0.006); IGF-1 levels were not significantly altered. No difference in corneal sensitivity was detected between groups. The concentration of IGFBP3 in tears was independent of IGF-1. Consistent with human tear measurements in vivo, IGFBP3 secretion was increased 2.2 fold (Ptears compared to normal controls blocked phosphorylation of the IGF-1R by IGF-1 (Ptears may attenuate IGF-1R signaling in the diabetic cornea. A long-term increase in IGFBP3 may contribute to epithelial compromise and the pathogenesis of ocular surface complications reported in diabetes. Copyright © 2012 Elsevier Inc. All rights reserved.

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

    Science.gov (United States)

    Yee, Douglas

    2012-07-03

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

  17. Biased and g protein-independent signaling of chemokine receptors

    DEFF Research Database (Denmark)

    Steen, Anne; Larsen, Olav; Thiele, Stefanie

    2014-01-01

    ), different receptors (with the same ligand), or different tissues or cells (for the same ligand-receptor pair). Most often biased signaling is differentiated into G protein-dependent and β-arrestin-dependent signaling. Yet, it may also cover signaling differences within these groups. Moreover, it may...

  18. Essential Function for PDLIM2 in Cell Polarization in Three-Dimensional Cultures by Feedback Regulation of the β1-Integrin–RhoA Signaling Axis

    Directory of Open Access Journals (Sweden)

    Ravi Kiran Deevi

    2014-05-01

    Full Text Available PDLIM2 is a cytoskeletal and nuclear PDZ-LIM domain protein that regulates the stability of Nuclear Factor kappa-B (NFκB and other transcription factors, and is required for polarized cell migration. PDLIM2 expression is suppressed by methylation in different cancers, but is strongly expressed in invasive breast cancer cells that have undergone an Epithelial Mesenchymal Transition (EMT. PDLIM2 is also expressed in non-transformed breast myoepithelial MCF10A cells and here we asked whether it is important for maintaining the polarized, epithelial phenotype of these cells. Suppression of PDLIM2 in MCF10A cells was sufficient to disrupt cell polarization and acini formation with increased proliferation and reduced apoptosis in the luminal space compared to control acini with hollow lumina. Spheroids with suppressed PDLIM2 exhibited increased expression of cell-cell and cell-matrix adhesion proteins including beta 1 (β1 integrin. Interestingly, levels of the Insulin-like growth factor 1 receptor (IGF-1 R and Receptor of activated protein kinase C 1 (RACK1, which scaffolds IGF-1R to β1 integrin, were also increased, indicating a transformed phenotype. Focal Adhesion Kinase (FAK and cofilin phosphorylation, and RhoA Guanosine Triphosphatase (GTPase activity were all enhanced in these spheroids compared to control acini. Importantly, inhibition of either FAK or Rho Kinase (ROCK was sufficient to rescue the polarity defect. We conclude that PDLIM2 expression is essential for feedback regulation of the β1-integrin-RhoA signalling axis and integration of cellular microenvironment signals with gene expression to control the polarity of breast epithelial acini structures. This is a mechanism by which PDLIM2 could mediate tumour suppression in breast epithelium.

  19. Influence of Maternal Undernutrition and Overfeeding on Cardiac Ciliary Neurotrophic Factor Receptor and Ventricular Size in Fetal Sheep

    Science.gov (United States)

    Dong, Feng; Ford, Stephen P.; Nijland, Mark J.; Nathanielsz, Peter W.; Ren, Jun

    2008-01-01

    Intrauterine nutrition status is reported to correlate with risk of cardiovascular diseases in adulthood. Either under- or over-nutrition during early to mid gestation contributes to altered fetal growth and ventricular geometry. This study was designed to examine myocardial expression of ciliary neurotrophic factor receptor α (CTNFRα) and its down-stream mediator signal transducer and activator of transcription 3 (STAT3) on maternal under- or over-nutrition-induced changes in fetal heart weight. Multiparous ewes were fed with 50% (nutrient-restricted, NR), 100% (control) or 150% (overfed, OF) of NRC requirements from 28 to 78 days of gestation (dG; Term 148 dG). Ewes were euthanized on day 78, and the gravid uteri and fetuses recovered. Ventricular protein expression of CTNFRα, STAT3, phosphorylated STAT3, insulin-like growth factor I receptor (IGF-1R) and IGF binding protein 3 (IGFBP3) were quantitated using western blot. Plasma cortisol levels were higher in both NR and OF fetuses whereas plasma IGF-1 levels were lower and higher, in NR and OF fetuses. Fetal weights were reduced by 29.9% in NR ewes and were increased by 22.2% in fetuses from OF ewes compared to control group. Nutrient restriction did not affect fetal heart or ventricular weights whereas overfeeding increased heart and ventricular weights. Protein expression of CTNFRα in fetal ventricular tissue was reduced in OF group whereas STAT3 and pSTAT3 levels were reduced in both NR and OF groups. Expression of IGF-1R and IGFBP3 was unaffected in either NR or OF group. These data suggested that compared with maternal undernutrition, intrauterine overfeeding during early to mid gestation is associated with increases fetal blood concentrations of cortisol and IGF-1 in association with ventricular hypertrophy where reduced expression of CNTFRα and STAT3 may play a role. PMID:17869083

  20. Molecular mechanisms of glucocorticoid receptor signaling

    Directory of Open Access Journals (Sweden)

    Marta Labeur

    2010-10-01

    Full Text Available This review highlights the most recent findings on the molecular mechanisms of the glucocorticoid receptor (GR. Most effects of glucocorticoids are mediated by the intracellular GR which is present in almost every tissue and controls transcriptional activation via direct and indirect mechanisms. Nevertheless the glucocorticoid responses are tissue -and gene- specific. GR associates selectively with corticosteroid ligands produced in the adrenal gland in response to changes of humoral homeostasis. Ligand interaction with GR promotes either GR binding to genomic glucocorticoid response elements, in turn modulating gene transcription, or interaction of GR monomers with other transcription factors activated by other signalling pathways leading to transrepression. The GR regulates a broad spectrum of physiological functions, including cell differentiation, metabolism and inflammatory responses. Thus, disruption or dysregulation of GR function will result in severe impairments in the maintenance of homeostasis and the control of adaptation to stress.

  1. Membrane Trafficking of Death Receptors: Implications on Signalling

    Directory of Open Access Journals (Sweden)

    Wulf Schneider-Brachert

    2013-07-01

    Full Text Available Death receptors were initially recognised as potent inducers of apoptotic cell death and soon ambitious attempts were made to exploit selective ignition of controlled cellular suicide as therapeutic strategy in malignant diseases. However, the complexity of death receptor signalling has increased substantially during recent years. Beyond activation of the apoptotic cascade, involvement in a variety of cellular processes including inflammation, proliferation and immune response was recognised. Mechanistically, these findings raised the question how multipurpose receptors can ensure selective activation of a particular pathway. A growing body of evidence points to an elegant spatiotemporal regulation of composition and assembly of the receptor-associated signalling complex. Upon ligand binding, receptor recruitment in specialized membrane compartments, formation of receptor-ligand clusters and internalisation processes constitute key regulatory elements. In this review, we will summarise the current concepts of death receptor trafficking and its implications on receptor-associated signalling events.

  2. Sweet Taste Receptor Signaling Network: Possible Implication for Cognitive Functioning

    Directory of Open Access Journals (Sweden)

    Menizibeya O. Welcome

    2015-01-01

    Full Text Available Sweet taste receptors are transmembrane protein network specialized in the transmission of information from special “sweet” molecules into the intracellular domain. These receptors can sense the taste of a range of molecules and transmit the information downstream to several acceptors, modulate cell specific functions and metabolism, and mediate cell-to-cell coupling through paracrine mechanism. Recent reports indicate that sweet taste receptors are widely distributed in the body and serves specific function relative to their localization. Due to their pleiotropic signaling properties and multisubstrate ligand affinity, sweet taste receptors are able to cooperatively bind multiple substances and mediate signaling by other receptors. Based on increasing evidence about the role of these receptors in the initiation and control of absorption and metabolism, and the pivotal role of metabolic (glucose regulation in the central nervous system functioning, we propose a possible implication of sweet taste receptor signaling in modulating cognitive functioning.

  3. Branchial expression and localization of the insulin-like growth factor 1 (IGF-1) receptor and changes in plasma IGF-1 and IGF-1 binding protein in striped bass during salinity acclimation

    DEFF Research Database (Denmark)

    Tipsmark, Christian Kølbæk; Madsen, Steffen; Borski, Russell

    2006-01-01

    In euryhaline teleosts the insulin-like growth factor 1 (IGF-1)/growth hormone axis is known to affect salinity tolerance and gill Na,K-ATPase activity. However, virtually nothing is known on expression and cellular localization of the IGF-1 receptor (IGF-1R) in the teleost gill during salinity a...

  4. SOCS proteins in regulation of receptor tyrosine kinase signaling

    DEFF Research Database (Denmark)

    Kazi, Julhash U.; Kabir, Nuzhat N.; Flores Morales, Amilcar

    2014-01-01

    Receptor tyrosine kinases (RTKs) are a family of cell surface receptors that play critical roles in signal transduction from extracellular stimuli. Many in this family of kinases are overexpressed or mutated in human malignancies and thus became an attractive drug target for cancer treatment....... The signaling mediated by RTKs must be tightly regulated by interacting proteins including protein-tyrosine phosphatases and ubiquitin ligases. The suppressors of cytokine signaling (SOCS) family proteins are well-known negative regulators of cytokine receptors signaling consisting of eight structurally similar...

  5. Nuclear Receptor Signaling Atlas: Opening Access to the Biology of Nuclear Receptor Signaling Pathways.

    Science.gov (United States)

    Becnel, Lauren B; Darlington, Yolanda F; Ochsner, Scott A; Easton-Marks, Jeremy R; Watkins, Christopher M; McOwiti, Apollo; Kankanamge, Wasula H; Wise, Michael W; DeHart, Michael; Margolis, Ronald N; McKenna, Neil J

    2015-01-01

    Signaling pathways involving nuclear receptors (NRs), their ligands and coregulators, regulate tissue-specific transcriptomes in diverse processes, including development, metabolism, reproduction, the immune response and neuronal function, as well as in their associated pathologies. The Nuclear Receptor Signaling Atlas (NURSA) is a Consortium focused around a Hub website (www.nursa.org) that annotates and integrates diverse 'omics datasets originating from the published literature and NURSA-funded Data Source Projects (NDSPs). These datasets are then exposed to the scientific community on an Open Access basis through user-friendly data browsing and search interfaces. Here, we describe the redesign of the Hub, version 3.0, to deploy "Web 2.0" technologies and add richer, more diverse content. The Molecule Pages, which aggregate information relevant to NR signaling pathways from myriad external databases, have been enhanced to include resources for basic scientists, such as post-translational modification sites and targeting miRNAs, and for clinicians, such as clinical trials. A portal to NURSA's Open Access, PubMed-indexed journal Nuclear Receptor Signaling has been added to facilitate manuscript submissions. Datasets and information on reagents generated by NDSPs are available, as is information concerning periodic new NDSP funding solicitations. Finally, the new website integrates the Transcriptomine analysis tool, which allows for mining of millions of richly annotated public transcriptomic data points in the field, providing an environment for dataset re-use and citation, bench data validation and hypothesis generation. We anticipate that this new release of the NURSA database will have tangible, long term benefits for both basic and clinical research in this field.

  6. Nuclear Receptor Signaling Atlas: Opening Access to the Biology of Nuclear Receptor Signaling Pathways.

    Directory of Open Access Journals (Sweden)

    Lauren B Becnel

    Full Text Available Signaling pathways involving nuclear receptors (NRs, their ligands and coregulators, regulate tissue-specific transcriptomes in diverse processes, including development, metabolism, reproduction, the immune response and neuronal function, as well as in their associated pathologies. The Nuclear Receptor Signaling Atlas (NURSA is a Consortium focused around a Hub website (www.nursa.org that annotates and integrates diverse 'omics datasets originating from the published literature and NURSA-funded Data Source Projects (NDSPs. These datasets are then exposed to the scientific community on an Open Access basis through user-friendly data browsing and search interfaces. Here, we describe the redesign of the Hub, version 3.0, to deploy "Web 2.0" technologies and add richer, more diverse content. The Molecule Pages, which aggregate information relevant to NR signaling pathways from myriad external databases, have been enhanced to include resources for basic scientists, such as post-translational modification sites and targeting miRNAs, and for clinicians, such as clinical trials. A portal to NURSA's Open Access, PubMed-indexed journal Nuclear Receptor Signaling has been added to facilitate manuscript submissions. Datasets and information on reagents generated by NDSPs are available, as is information concerning periodic new NDSP funding solicitations. Finally, the new website integrates the Transcriptomine analysis tool, which allows for mining of millions of richly annotated public transcriptomic data points in the field, providing an environment for dataset re-use and citation, bench data validation and hypothesis generation. We anticipate that this new release of the NURSA database will have tangible, long term benefits for both basic and clinical research in this field.

  7. The Role of Type I Insulin Like Growth Factor Receptor (IGF-IR) in Adult and Childhood Acute Lymphoblastic Leukemia

    International Nuclear Information System (INIS)

    KAMEL, M.M.; HAMMAM, A.A.; ELHOSEINY, Sh.M.; MOKHLES, A.; MOHSEN, E.

    2008-01-01

    Background: Type 1 insulin like growth factor receptor (IGF-IR) is over expressed in many tumors including hematological cancers. It is a critical signaling molecule for tumor cell proliferation and survival. Data suggest that IGF-IR antibodies can effectively and specifically inhibit cancer cell growth in vitro and in vivo. Blockage of IGF-IR expression could be a promising therapeutic approach for the management of cancer patients. Aim of Work: To characterize the expression pattern of IGF-IR gene in malignant lymphoblasts of children and adults suffering from ALL in relation to clinical features at diagnosis. Patients and Methods: The expression of IGF-IR was analyzed in 60 patients with ALL, 30 childhood ALL (16 newly diagnosed and 14 in complete remission) and 30 adulthood ALL (15 newly diagnosed and 15 in complete remission) together with 20 normal age and sex matched healthy controls using a Real-Time Quantitative Reverse- Transcriptase Polymerase Chain Reaction (RTQ-PCR) to assess the possible relation, association or correlation between IGF-IR expression and ALL clinical and laboratory features at diagnosis. Results: IGF-IR was expressed in all 60 patients with ALL; the expression levels of IGF-IR were significantly higher in newly diagnosed patients than in patients in complete remission (CR) and controls (p<0.001). There were no statistically significant differences in the expression of IGF-IR between patients with different clinical and laboratory features. Conclusion: IGF-1R seems to play a crucial role in patients with ALL since it is expressed in all ALL cases (adulthood and childhood). Therefore, new therapeutic agents targeting IGF-1R may provide a better chance for those patients

  8. 17β-estradiol induces stearoyl-CoA desaturase-1 expression in estrogen receptor-positive breast cancer cells

    International Nuclear Information System (INIS)

    Belkaid, Anissa; Duguay, Sabrina R.; Ouellette, Rodney J.; Surette, Marc E.

    2015-01-01

    To sustain cell growth, cancer cells exhibit an altered metabolism characterized by increased lipogenesis. Stearoyl-CoA desaturase-1 (SCD-1) catalyzes the production of monounsaturated fatty acids that are essential for membrane biogenesis, and is required for cell proliferation in many cancer cell types. Although estrogen is required for the proliferation of many estrogen-sensitive breast carcinoma cells, it is also a repressor of SCD-1 expression in liver and adipose. The current study addresses this apparent paradox by investigating the impact of estrogen on SCD-1 expression in estrogen receptor-α-positive breast carcinoma cell lines. MCF-7 and T47D mammary carcinomas cells and immortalized MCF-10A mammary epithelial cells were hormone-starved then treated or not with 17β-estradiol. SCD-1 activity was assessed by measuring cellular monounsaturated/saturated fatty acid (MUFA/SFA) ratios, and SCD-1 expression was measured by qPCR, immunoblot, and immunofluorescence analyses. The role of SCD-1 in cell proliferation was measured following treatment with the SCD-1 inhibitor A959372 and following SCD-1 silencing using siRNA. The involvement of IGF-1R on SCD-1 expression was measured using the IGF-1R antagonist AG1024. The expression of SREBP-1c, a transcription factor that regulates SCD-1, was measured by qPCR, and by immunoblot analyses. 17β-estradiol significantly induced cell proliferation and SCD-1 activity in MCF-7 and T47D cells but not MCF-10A cells. Accordingly, 17β-estradiol significantly increased SCD-1 mRNA and protein expression in MCF-7 and T47D cells compared to untreated cells. Treatment of MCF-7 cells with 4-OH tamoxifen or siRNA silencing of estrogen receptor-α largely prevented 17β-estradiol-induced SCD-1 expression. 17β-estradiol increased SREBP-1c expression and induced the mature active 60 kDa form of SREBP-1. The selective SCD-1 inhibitor or siRNA silencing of SCD-1 blocked the 17β-estradiol-induced cell proliferation and increase in

  9. Effect Of IGF-1 On Expression Of Gh Receptor, IGF-1, IGF-1 ...

    African Journals Online (AJOL)

    ... and the skin expression of growth hormone receptor (GHR), insulin-like growth factor1 (IGF-1), insulin-like growth factor receptor (IGF- R), KAP3.2 and KAP6-1 mRNA were measured by RT-PCR. The results indicated that IGF-1 could degrade GHR gene expression, have no effect of IGF-1 and IGF-1R gene expression, ...

  10. (igf1/igf1r) with milk production tr

    African Journals Online (AJOL)

    Gosia

    2016-06-15

    Jun 15, 2016 ... fragment length polymorphism (PCR-RFLP) (TaiI and MspI restriction enzymes) and amplification-created restriction site (ACRS) (SnaBI ... is the first association study based on polymorphisms of the primary genes encoding the IGF-1 system in a small herd of .... However, protein content was highest in milk ...

  11. Dynamics of the actin cytoskeleton mediates receptor cross talk: An emerging concept in tuning receptor signaling

    Science.gov (United States)

    Mattila, Pieta K.; Batista, Facundo D.

    2016-01-01

    Recent evidence implicates the actin cytoskeleton in the control of receptor signaling. This may be of particular importance in the context of immune receptors, such as the B cell receptor, where dysregulated signaling can result in autoimmunity and malignancy. Here, we discuss the role of the actin cytoskeleton in controlling receptor compartmentalization, dynamics, and clustering as a means to regulate receptor signaling through controlling the interactions with protein partners. We propose that the actin cytoskeleton is a point of integration for receptor cross talk through modulation of protein dynamics and clustering. We discuss the implication of this cross talk via the cytoskeleton for both ligand-induced and low-level constitutive (tonic) signaling necessary for immune cell survival. PMID:26833785

  12. Role of protein dynamics in transmembrane receptor signalling

    DEFF Research Database (Denmark)

    Wang, Yong; Bugge, Katrine Østergaard; Kragelund, Birthe Brandt

    2018-01-01

    Cells are dependent on transmembrane receptors to communicate and transform chemical and physical signals into intracellular responses. Because receptors transport 'information', conformational changes and protein dynamics play a key mechanistic role. We here review examples where experiment...... to function. Because the receptors function in a heterogeneous environment and need to be able to switch between distinct functional states, they may be particularly sensitive to small perturbations that complicate studies linking dynamics to function....

  13. Investigation on the role of IGF-1 signal transduction in the biological radiation responses

    Energy Technology Data Exchange (ETDEWEB)

    Jung, U Hee; Jo, Sung Kee; Park, Hae Ran; Oh, Soo Jin; Cho, Eun Hee; Eom, Hyun Soo; Ju, Eun Jin

    2009-05-15

    Effects of {gamma}-irradiation on the IGF-1 related gene expressions and activations in various cell lines - Various expression patterns of IGF-1 and IGF-1R following {gamma}-irradiation were observed according to the cell lines - The increased expressions of IGF-1 and IGF-1R were observed in Balb/3T3 and NIH/3T3 cells - Among the IGF-1 downstream signaling molecules, the phosphorylated ERK5 were not changed by {gamma}-irradiation in all three examined cell lines, whereas the phosphorylated p65 were increased by {gamma} -irradiation in all cell lines. The role of IGF-1 and p38 signaling in {gamma}-irradiated mouse embryonic fibroblast (MEF) cells - In MEF cells, IGF-1 signaling molecules were decreased and p21/phosphorylated p38 were increased by {gamma}-irradiation - The experiments with IGF-1R inhibitor (AG1024) and p38 inhibitor (SB203580) revealed that IGF-1 signaling is involved but not essential in radiation-induced cell growth arrest and senescence and that p38 MAP kinase play a important role in this cellular radiation response. The role of IGF-1 and p38 signaling in {gamma}-irradiated mouse fibroblast (NIH/3T3) cell - In NIH/3T3 cells, IGF-1 signaling molecules and p21/phosphorylated p38 were increased by {gamma} -irradiation. - However, the experiments with IGF-1R inhibitor (AG1024) and p38 inhibitor (SB203580) revealed that IGF-1 and p38 signaling do not play a crucial role in radiation-induced cell growth arrest and senescence in NIH/3T3 cells. Effects of {gamma}-irradiation on the expressions and activations on the genes related to the IGF-1 signaling in mouse tissues - In {gamma}-irradiated mice, the increased expressions of IGF-1 and IGF-1R were observed in the lung and kidney at 2 months after irradiation, and in all the tissues examined (lung, liver and kidney) at 6 months after irradiation. - In the lung of {gamma}-irradiated mice at 6 months after irradiation, the increases of IGF-1R, phosphorylated FOXO3a, p65, p38, p21 were observed. - The

  14. Investigation on the role of IGF-1 signal transduction in the biological radiation responses

    International Nuclear Information System (INIS)

    Jung, U Hee; Jo, Sung Kee; Park, Hae Ran; Oh, Soo Jin; Cho, Eun Hee; Eom, Hyun Soo; Ju, Eun Jin

    2009-05-01

    Effects of γ-irradiation on the IGF-1 related gene expressions and activations in various cell lines - Various expression patterns of IGF-1 and IGF-1R following γ-irradiation were observed according to the cell lines - The increased expressions of IGF-1 and IGF-1R were observed in Balb/3T3 and NIH/3T3 cells - Among the IGF-1 downstream signaling molecules, the phosphorylated ERK5 were not changed by γ-irradiation in all three examined cell lines, whereas the phosphorylated p65 were increased by γ -irradiation in all cell lines. The role of IGF-1 and p38 signaling in γ-irradiated mouse embryonic fibroblast (MEF) cells - In MEF cells, IGF-1 signaling molecules were decreased and p21/phosphorylated p38 were increased by γ-irradiation - The experiments with IGF-1R inhibitor (AG1024) and p38 inhibitor (SB203580) revealed that IGF-1 signaling is involved but not essential in radiation-induced cell growth arrest and senescence and that p38 MAP kinase play a important role in this cellular radiation response. The role of IGF-1 and p38 signaling in γ-irradiated mouse fibroblast (NIH/3T3) cell - In NIH/3T3 cells, IGF-1 signaling molecules and p21/phosphorylated p38 were increased by γ -irradiation. - However, the experiments with IGF-1R inhibitor (AG1024) and p38 inhibitor (SB203580) revealed that IGF-1 and p38 signaling do not play a crucial role in radiation-induced cell growth arrest and senescence in NIH/3T3 cells. Effects of γ-irradiation on the expressions and activations on the genes related to the IGF-1 signaling in mouse tissues - In γ-irradiated mice, the increased expressions of IGF-1 and IGF-1R were observed in the lung and kidney at 2 months after irradiation, and in all the tissues examined (lung, liver and kidney) at 6 months after irradiation. - In the lung of γ-irradiated mice at 6 months after irradiation, the increases of IGF-1R, phosphorylated FOXO3a, p65, p38, p21 were observed. - The patterns of altered expressions showed significant

  15. Modulation of β-catenin signaling by glucagon receptor activation.

    Directory of Open Access Journals (Sweden)

    Jiyuan Ke

    Full Text Available The glucagon receptor (GCGR is a member of the class B G protein-coupled receptor family. Activation of GCGR by glucagon leads to increased glucose production by the liver. Thus, glucagon is a key component of glucose homeostasis by counteracting the effect of insulin. In this report, we found that in addition to activation of the classic cAMP/protein kinase A (PKA pathway, activation of GCGR also induced β-catenin stabilization and activated β-catenin-mediated transcription. Activation of β-catenin signaling was PKA-dependent, consistent with previous reports on the parathyroid hormone receptor type 1 (PTH1R and glucagon-like peptide 1 (GLP-1R receptors. Since low-density-lipoprotein receptor-related protein 5 (Lrp5 is an essential co-receptor required for Wnt protein mediated β-catenin signaling, we examined the role of Lrp5 in glucagon-induced β-catenin signaling. Cotransfection with Lrp5 enhanced the glucagon-induced β-catenin stabilization and TCF promoter-mediated transcription. Inhibiting Lrp5/6 function using Dickkopf-1(DKK1 or by expression of the Lrp5 extracellular domain blocked glucagon-induced β-catenin signaling. Furthermore, we showed that Lrp5 physically interacted with GCGR by immunoprecipitation and bioluminescence resonance energy transfer assays. Together, these results reveal an unexpected crosstalk between glucagon and β-catenin signaling, and may help to explain the metabolic phenotypes of Lrp5/6 mutations.

  16. Functionally biased signalling properties of 7TM receptors - opportunities for drug development for the ghrelin receptor

    DEFF Research Database (Denmark)

    Sivertsen, B; Holliday, N; Madsen, A N

    2013-01-01

    UNLABELLED: The ghrelin receptor is a 7 transmembrane (7TM) receptor involved in a variety of physiological functions including growth hormone secretion, increased food intake and fat accumulation as well as modulation of reward and cognitive functions. Because of its important role in metabolism...... and energy expenditure, the ghrelin receptor has become an important therapeutic target for drug design and the development of anti-obesity compounds. However, none of the compounds developed so far have been approved for commercial use. Interestingly, the ghrelin receptor is able to signal through several...... review, we have described how ligands and mutations in the 7TM receptor may bias the receptors to favour either one G-protein over another or to promote G-protein independent signalling pathways rather than G-protein-dependent pathways. For the ghrelin receptor, both agonist and inverse agonists have...

  17. Protein kinase C alpha controls erythropoietin receptor signaling.

    NARCIS (Netherlands)

    M.M. von Lindern (Marieke); M. Parren-Van Amelsvoort (Martine); T.B. van Dijk (Thamar); E. Deiner; B. Löwenberg (Bob); E. van den Akker (Emile); S. van Emst-de Vries (Sjenet); P.J. Willems (Patrick); H. Beug (Hartmut)

    2000-01-01

    textabstractProtein kinase C (PKC) is implied in the activation of multiple targets of erythropoietin (Epo) signaling, but its exact role in Epo receptor (EpoR) signal transduction and in the regulation of erythroid proliferation and differentiation remained elusive. We

  18. Protein kinase C alpha controls erythropoietin receptor signaling

    NARCIS (Netherlands)

    von Lindern, M.; Parren-van Amelsvoort, M.; van Dijk, T.; Deiner, E.; van den Akker, E.; van Emst-de Vries, S.; Willems, P.; Beug, H.; Löwenberg, B.

    2000-01-01

    Protein kinase C (PKC) is implied in the activation of multiple targets of erythropoietin (Epo) signaling, but its exact role in Epo receptor (EpoR) signal transduction and in the regulation of erythroid proliferation and differentiation remained elusive. We analyzed the effect of PKC inhibitors

  19. Cocaine Inhibits Dopamine D2 Receptor Signaling via Sigma-1-D2 Receptor Heteromers

    Science.gov (United States)

    Navarro, Gemma; Moreno, Estefania; Bonaventura, Jordi; Brugarolas, Marc; Farré, Daniel; Aguinaga, David; Mallol, Josefa; Cortés, Antoni; Casadó, Vicent; Lluís, Carmen; Ferre, Sergi

    2013-01-01

    Under normal conditions the brain maintains a delicate balance between inputs of reward seeking controlled by neurons containing the D1-like family of dopamine receptors and inputs of aversion coming from neurons containing the D2-like family of dopamine receptors. Cocaine is able to subvert these balanced inputs by altering the cell signaling of these two pathways such that D1 reward seeking pathway dominates. Here, we provide an explanation at the cellular and biochemical level how cocaine may achieve this. Exploring the effect of cocaine on dopamine D2 receptors function, we present evidence of σ1 receptor molecular and functional interaction with dopamine D2 receptors. Using biophysical, biochemical, and cell biology approaches, we discovered that D2 receptors (the long isoform of the D2 receptor) can complex with σ1 receptors, a result that is specific to D2 receptors, as D3 and D4 receptors did not form heteromers. We demonstrate that the σ1-D2 receptor heteromers consist of higher order oligomers, are found in mouse striatum and that cocaine, by binding to σ1 -D2 receptor heteromers, inhibits downstream signaling in both cultured cells and in mouse striatum. In contrast, in striatum from σ1 knockout animals these complexes are not found and this inhibition is not seen. Taken together, these data illuminate the mechanism by which the initial exposure to cocaine can inhibit signaling via D2 receptor containing neurons, destabilizing the delicate signaling balance influencing drug seeking that emanates from the D1 and D2 receptor containing neurons in the brain. PMID:23637801

  20. Identification of signaling pathways associated with cancer protection in Laron syndrome.

    Science.gov (United States)

    Lapkina-Gendler, Lena; Rotem, Itai; Pasmanik-Chor, Metsada; Gurwitz, David; Sarfstein, Rive; Laron, Zvi; Werner, Haim

    2016-05-01

    The growth hormone (GH)-insulin-like growth factor-1 (IGF1) pathway emerged in recent years as a critical player in cancer biology. Enhanced expression or activation of specific components of the GH-IGF1 axis, including the IGF1 receptor (IGF1R), is consistently associated with a transformed phenotype. Recent epidemiological studies have shown that patients with Laron syndrome (LS), the best-characterized entity among the congenital IGF1 deficiencies, seem to be protected from cancer development. To identify IGF1-dependent genes and signaling pathways associated with cancer protection in LS, we conducted a genome-wide analysis using immortalized lymphoblastoid cells derived from LS patients and healthy controls of the same gender, age range, and ethnic origin. Our analyses identified a collection of genes that are either over- or under-represented in LS-derived lymphoblastoids. Gene differential expression occurs in several gene families, including cell cycle, metabolic control, cytokine-cytokine receptor interaction, Jak-STAT signaling, and PI3K-AKT signaling. Major differences between LS and healthy controls were also noticed in pathways associated with cell cycle distribution, apoptosis, and autophagy. Our results highlight the key role of the GH-IGF1 axis in the initiation and progression of cancer. Furthermore, data are consistent with the concept that homozygous congenital IGF1 deficiency may confer protection against future tumor development. © 2016 Society for Endocrinology.

  1. Interaction of single nucleotide polymorphisms in ADRB2, ADRB3, TNF, IL6, IGF1R, LIPC, LEPR, and GHRL with physical activity on the risk of type 2 diabetes mellitus and changes in characteristics of the metabolic syndrome: The Finnish Diabetes Prevention Study.

    Science.gov (United States)

    Kilpeläinen, Tuomas O; Lakka, Timo A; Laaksonen, David E; Mager, Ursula; Salopuro, Titta; Kubaszek, Agata; Todorova, Boryana; Laukkanen, Olli; Lindström, Jaana; Eriksson, Johan G; Hämäläinen, Helena; Aunola, Sirkka; Ilanne-Parikka, Pirjo; Keinänen-Kiukaanniemi, Sirkka; Tuomilehto, Jaako; Laakso, Markku; Uusitupa, Matti

    2008-03-01

    Single nucleotide polymorphisms (SNPs) in the ADRB2, ADRB3, TNF, IL6, IGF1R, LIPC, LEPR, and GHRL genes were associated with the conversion from impaired glucose tolerance (IGT) to type 2 diabetes mellitus (T2D) in the Finnish Diabetes Prevention Study (DPS). In this study, we determined whether polymorphisms in these genes modified the effect of changes in physical activity (PA) on the risk of T2D in the DPS. Moreover, we assessed whether the polymorphisms modified the effect of changes in PA on changes in measures of body fat, serum lipids, and blood pressure during the first year of the follow-up of the DPS. Overweight subjects with IGT (n = 487) were followed for an average of 4.1 years, and PA was assessed annually with a questionnaire. The interactions of the polymorphisms with changes in total and moderate-to-vigorous PA on the conversion to T2D during the 4.1-year follow-up were assessed using Cox regression with adjustments for the other components of the intervention (dietary changes, weight reduction). Univariate analysis of variance was used to assess interactions on changes in continuous variables during the first year of the follow-up. No interaction between the polymorphisms and PA on the conversion to T2D was found. The Leu72Met (rs696217) polymorphism in GHRL modified the effect of moderate-to-vigorous PA on changes in weight and waist circumference, the -501A/C (rs26802) polymorphism in GHRL modified the effect of total and moderate-to-vigorous PA on change in high-density lipoprotein cholesterol, and the Lys109Arg (rs1137100) polymorphism in LEPR modified the effect of total PA on change in blood pressure. In conclusion, genetic variation may modify the magnitude of the beneficial effects of PA on characteristics of the metabolic syndrome in persons with IGT.

  2. Cysteinyl-Leukotriene Receptors and Cellular Signals

    Directory of Open Access Journals (Sweden)

    G. Enrico Rovati

    2007-01-01

    Full Text Available Cysteinyl-leukotrienes (cysteinyl-LTs exert a range of proinflammatory effects, such as constriction of airways and vascular smooth muscle, increase of endothelial cell permeability leading to plasma exudation and edema, and enhanced mucus secretion. They have proved to be important mediators in asthma, allergic rhinitis, and other inflammatory conditions, including cardiovascular diseases, cancer, atopic dermatitis, and urticaria. The classification into subtypes of the cysteinyl-LT receptors (CysLTRs was based initially on binding and functional data, obtained using the natural agonists and a wide range of antagonists. CysLTRs have proved remarkably resistant to cloning. However, in 1999 and 2000, the CysLT1R and CysLT2R were successfully cloned and both shown to be members of the G-protein coupled receptors (GPCRs superfamily. Molecular cloning has confirmed most of the previous pharmacological characterization and identified distinct expression patterns only partially overlapping. Recombinant CysLTRs couple to the Gq/11 pathway that modulates inositol phospholipids hydrolysis and calcium mobilization, whereas in native systems, they often activate a pertussis toxin-insensitive Gi/o-protein, or are coupled promiscuously to both G-proteins. Interestingly, recent data provide evidence for the existence of an additional receptor subtype that seems to respond to both cysteinyl-LTs and uracil nucleosides, and of an intracellular pool of CysLTRs that may have roles different from those of plasma membrane receptors. Finally, a cross-talk between the cysteinyl-LT and the purine systems is being delineated. This review will summarize recent data derived from studies on the molecular and cellular pharmacology of CysLTRs.

  3. Signal transduction through the IL-4 and insulin receptor families.

    Science.gov (United States)

    Wang, L M; Keegan, A; Frankel, M; Paul, W E; Pierce, J H

    1995-07-01

    Activation of tyrosine kinase-containing receptors and intracellular tyrosine kinases by ligand stimulation is known to be crucial for mediating initial and subsequent events involved in mitogenic signal transduction. Receptors for insulin and insulin-like growth factor 1 (IGF-1) contain cytoplasmic tyrosine kinase domains that undergo autophosphorylation upon ligand stimulation. Activation of these receptors also leads to pronounced and rapid tyrosine phosphorylation of insulin receptor substrate 1 (IRS-1) in cells of connective tissue origin. A related substrate, designated 4PS, is similarly phosphorylated by insulin and IGF-1 stimulation in many hematopoietic cell types. IRS-1 and 4PS possess a number of tyrosine phosphorylation sites that are within motifs that bind specific SH2-containing molecules known to be involved in mitogenic signaling such as PI-3 kinase, SHPTP-2 (Syp) and Grb-2. Thus, they appear to act as docking substrates for a variety of signaling molecules. The majority of hematopoietic cytokines bind to receptors that do not possess intrinsic kinase activity, and these receptors have been collectively termed as members of the hematopoietin receptor superfamily. Despite their lack of tyrosine kinase domains, stimulation of these receptors has been demonstrated to activate intracellular kinases leading to tyrosine phosphorylation of multiple substrates. Recent evidence has demonstrated that activation of different members of the Janus family of tyrosine kinases is involved in mediating tyrosine phosphorylation events by specific cytokines. Stimulation of the interleukin 4 (IL-4) receptor, a member of the hematopoietin receptor superfamily, is thought to result in activation of Jak1, Jak3, and/or Fes tyrosine kinases.(ABSTRACT TRUNCATED AT 250 WORDS)

  4. IGF system targeted therapy: Therapeutic opportunities for ovarian cancer.

    Science.gov (United States)

    Liefers-Visser, J A L; Meijering, R A M; Reyners, A K L; van der Zee, A G J; de Jong, S

    2017-11-01

    The insulin-like growth factor (IGF) system comprises multiple growth factor receptors, including insulin-like growth factor 1 receptor (IGF-1R), insulin receptor (IR) -A and -B. These receptors are activated upon binding to their respective growth factor ligands, IGF-I, IGF-II and insulin, and play an important role in development, maintenance, progression, survival and chemotherapeutic response of ovarian cancer. In many pre-clinical studies anti-IGF-1R/IR targeted strategies proved effective in reducing growth of ovarian cancer models. In addition, anti-IGF-1R targeted strategies potentiated the efficacy of platinum based chemotherapy. Despite the vast amount of encouraging and promising pre-clinical data, anti-IGF-1R/IR targeted strategies lacked efficacy in the clinic. The question is whether targeting the IGF-1R/IR signaling pathway still holds therapeutic potential. In this review we address the complexity of the IGF-1R/IR signaling pathway, including receptor heterodimerization within and outside the IGF system and downstream signaling. Further, we discuss the implications of this complexity on current targeted strategies and indicate therapeutic opportunities for successful targeting of the IGF-1R/IR signaling pathway in ovarian cancer. Multiple-targeted approaches circumventing bidirectional receptor tyrosine kinase (RTK) compensation and prevention of system rewiring are expected to have more therapeutic potential. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

  5. CSF-1 Receptor Signaling in Myeloid Cells

    Science.gov (United States)

    Stanley, E. Richard; Chitu, Violeta

    2014-01-01

    The CSF-1 receptor (CSF-1R) is activated by the homodimeric growth factors colony-stimulating factor-1 (CSF-1) and interleukin-34 (IL-34). It plays important roles in development and in innate immunity by regulating the development of most tissue macrophages and osteoclasts, of Langerhans cells of the skin, of Paneth cells of the small intestine, and of brain microglia. It also regulates the differentiation of neural progenitor cells and controls functions of oocytes and trophoblastic cells in the female reproductive tract. Owing to this broad tissue expression pattern, it plays a central role in neoplastic, inflammatory, and neurological diseases. In this review we summarize the evolution, structure, and regulation of expression of the CSF-1R gene. We review, the structures of CSF-1, IL-34, and the CSF-1R and the mechanism of ligand binding to and activation of the receptor. We further describe the pathways regulating macrophage survival, proliferation, differentiation, and chemotaxis downstream from the CSF-1R. PMID:24890514

  6. 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

  7. Signal Diversity of Receptor for Advanced Glycation End Products.

    Science.gov (United States)

    Sakaguchi, Masakiyo; Kinoshita, Rie; Putranto, Endy Widya; Ruma, I Made Winarsa; Sumardika, I Wayan; Youyi, Chen; Tomonobu, Naoko; Yamamoto, Ken-Ichi; Murata, Hitoshi

    2017-12-01

    The receptor for advanced glycation end products (RAGE) is involved in inflammatory pathogenesis. It functions as a receptor to multiple ligands such as AGEs, HMGB1 and S100 proteins, activating multiple intracellular signaling pathways with each ligand binding. The molecular events by which ligand-activated RAGE controls diverse signaling are not well understood, but some progress was made recently. Accumulating evidence revealed that RAGE has multiple binding partners within the cytoplasm and on the plasma membrane. It was first pointed out in 2008 that RAGE's cytoplasmic tail is able to recruit Diaphanous-1 (Dia-1), resulting in the acquisition of increased cellular motility through Rac1/Cdc42 activation. We also observed that within the cytosol, RAGE's cytoplasmic tail behaves similarly to a Toll-like receptor (TLR4)-TIR domain, interacting with TIRAP and MyD88 adaptor molecules that in turn activate multiple downstream signals. Subsequent studies demonstrated the presence of an alternative adaptor molecule, DAP10, on the plasma membrane. The coupling of RAGE with DAP10 is critical for enhancing the RAGE-mediated survival signal. Interestingly, RAGE interaction on the membrane was not restricted to DAP10 alone. The chemotactic G-protein-coupled receptors (GPCRs) formyl peptide receptors1 and 2 (FPR1 and FPR2) also interacted with RAGE on the plasma membrane. Binding interaction between leukotriene B4 receptor 1 (BLT1) and RAGE was also demonstrated. All of the interactions affected the RAGE signal polarity. These findings indicate that functional interactions between RAGE and various molecules within the cytoplasmic area or on the membrane area coordinately regulate multiple ligand-mediated RAGE responses, leading to typical cellular phenotypes in several pathological settings. Here we review RAGE's signaling diversity, to contribute to the understanding of the elaborate functions of RAGE in physiological and pathological contexts.

  8. Hindbrain ghrelin receptor signaling is sufficient to maintain fasting glucose.

    Directory of Open Access Journals (Sweden)

    Michael M Scott

    Full Text Available The neuronal coordination of metabolic homeostasis requires the integration of hormonal signals with multiple interrelated central neuronal circuits to produce appropriate levels of food intake, energy expenditure and fuel availability. Ghrelin, a peripherally produced peptide hormone, circulates at high concentrations during nutrient scarcity. Ghrelin promotes food intake, an action lost in ghrelin receptor null mice and also helps maintain fasting blood glucose levels, ensuring an adequate supply of nutrients to the central nervous system. To better understand mechanisms of ghrelin action, we have examined the roles of ghrelin receptor (GHSR expression in the mouse hindbrain. Notably, selective hindbrain ghrelin receptor expression was not sufficient to restore ghrelin-stimulated food intake. In contrast, the lowered fasting blood glucose levels observed in ghrelin receptor-deficient mice were returned to wild-type levels by selective re-expression of the ghrelin receptor in the hindbrain. Our results demonstrate the distributed nature of the neurons mediating ghrelin action.

  9. Vitamin D Receptor Signaling and Cancer.

    Science.gov (United States)

    Campbell, Moray J; Trump, Donald L

    2017-12-01

    The vitamin D receptor (VDR) binds the secosteroid hormone 1,25(OH) 2 D 3 with high affinity and regulates gene programs that control a serum calcium levels, as well as cell proliferation and differentiation. A significant focus has been to exploit the VDR in cancer settings. Although preclinical studies have been strongly encouraging, to date clinical trials have delivered equivocal findings that have paused the clinical translation of these compounds. However, it is entirely possible that mining of genomic data will help to refine precisely what are the key anticancer actions of vitamin D compounds and where these can be used most effectively. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

  10. Receptor downregulation and desensitization enhance the information processing ability of signalling receptors

    Directory of Open Access Journals (Sweden)

    Resat Haluk

    2007-11-01

    Full Text Available Abstract Background In addition to initiating signaling events, the activation of cell surface receptors also triggers regulatory processes that restrict the duration of signaling. Acute attenuation of signaling can be accomplished either via ligand-induced internalization of receptors (endocytic downregulation or via ligand-induced receptor desensitization. These phenomena have traditionally been viewed in the context of adaptation wherein the receptor system enters a refractory state in the presence of sustained ligand stimuli and thereby prevents the cell from over-responding to the ligand. Here we use the epidermal growth factor receptor (EGFR and G-protein coupled receptors (GPCR as model systems to respectively examine the effects of downregulation and desensitization on the ability of signaling receptors to decode time-varying ligand stimuli. Results Using a mathematical model, we show that downregulation and desensitization mechanisms can lead to tight and efficient input-output coupling thereby ensuring synchronous processing of ligand inputs. Frequency response analysis indicates that upstream elements of the EGFR and GPCR networks behave like low-pass filters with the system being able to faithfully transduce inputs below a critical frequency. Receptor downregulation and desensitization increase the filter bandwidth thereby enabling the receptor systems to decode inputs in a wider frequency range. Further, system-theoretic analysis reveals that the receptor systems are analogous to classical mechanical over-damped systems. This analogy enables us to metaphorically describe downregulation and desensitization as phenomena that make the systems more resilient in responding to ligand perturbations thereby improving the stability of the system resting state. Conclusion Our findings suggest that in addition to serving as mechanisms for adaptation, receptor downregulation and desensitization can play a critical role in temporal information

  11. The Cannabinoid Receptor CB1 Modulates the Signaling Properties of the Lysophosphatidylinositol Receptor GPR55*

    Science.gov (United States)

    Kargl, Julia; Balenga, Nariman; Parzmair, Gerald P.; Brown, Andrew J.; Heinemann, Akos; Waldhoer, Maria

    2012-01-01

    The G protein-coupled receptor (GPCR) 55 (GPR55) and the cannabinoid receptor 1 (CB1R) are co-expressed in many tissues, predominantly in the central nervous system. Seven transmembrane spanning (7TM) receptors/GPCRs can form homo- and heteromers and initiate distinct signaling pathways. Recently, several synthetic CB1 receptor inverse agonists/antagonists, such as SR141716A, AM251, and AM281, were reported to activate GPR55. Of these, SR141716A was marketed as a promising anti-obesity drug, but was withdrawn from the market because of severe side effects. Here, we tested whether GPR55 and CB1 receptors are capable of (i) forming heteromers and (ii) whether such heteromers could exhibit novel signaling patterns. We show that GPR55 and CB1 receptors alter each others signaling properties in human embryonic kidney (HEK293) cells. We demonstrate that the co-expression of FLAG-CB1 receptors in cells stably expressing HA-GPR55 specifically inhibits GPR55-mediated transcription factor activation, such as nuclear factor of activated T-cells and serum response element, as well as extracellular signal-regulated kinases (ERK1/2) activation. GPR55 and CB1 receptors can form heteromers, but the internalization of both receptors is not affected. In addition, we observe that the presence of GPR55 enhances CB1R-mediated ERK1/2 and nuclear factor of activated T-cell activation. Our data provide the first evidence that GPR55 can form heteromers with another 7TM/GPCR and that this interaction with the CB1 receptor has functional consequences in vitro. The GPR55-CB1R heteromer may play an important physiological and/or pathophysiological role in tissues endogenously co-expressing both receptors. PMID:23161546

  12. 17β-Estradiol-induced cell proliferation requires estrogen receptor (ER) α monoubiquitination.

    Science.gov (United States)

    La Rosa, Piergiorgio; Pesiri, Valeria; Marino, Maria; Acconcia, Filippo

    2011-07-01

    Protein monoubiquitination (monoUbq) (i.e., the attachment of one single ubiquitin to the substrate) is a non-proteolytic reversible modification that controls protein functions. Among other proteins, the estrogen receptor α (ERα), which mediates the pleiotropic effects of the cognate hormone 17β-estradiol (E2), is a monoubiquitinated protein. Although it has been demonstrated that E2 rapidly reduces ERα monoUbq in breast cancer cells, the impact of monoUbq in the regulation of the ERα activities is poorly appreciated. Here, we show that mutation of the ERα monoUbq sites prevents the E2-induced ERα phosphorylation in the serine residue 118 (S118), reduces ERα transcriptional activity, and precludes the ERα-mediated extranuclear activation of signaling pathways (i.e., AKT activation) thus impeding the E2-induced cyclin D1 promoter activation and consequently cell proliferation. In addition, the interference with ERα monoUbq deregulates E2-induced association of ERα to the insulin like growth factor receptor (IGF-1-R). Altogether these data demonstrate an inherent role for monoUbq in ERα signaling and point to the physiological function of ERα monoUbq in the regulation of E2-induced cell proliferation. Copyright © 2011 Elsevier Inc. All rights reserved.

  13. New insights into how trafficking regulates T cell receptor signaling

    Directory of Open Access Journals (Sweden)

    Jieqiong Lou

    2016-07-01

    Full Text Available AbstractThere is emerging evidence that exocytosis plays an important role in regulating T cell receptor (TCR signaling. The trafficking molecules involved in lytic granule (LG secretion in cytotoxic T lymphocytes (CTL have been well studied due to the immune disorder known as familial hemophagocytic lymphohisiocytosis (FHLH. However, the knowledge of trafficking machineries regulating the exocytosis of receptors and signaling molecules remains quite limited. In this review, we summarize the reported trafficking molecules involved in the transport of the TCR and downstream signaling molecules to the cell surface. By combining this information with the known knowledge of LG exocytosis and general exocytic trafficking machinery, we attempt to draw a more complete picture of how the TCR signaling network and exocytic trafficking matrix are interconnected to facilitate T cell activation. This also highlights how membrane compartmentalization facilitates the spatiotemporal organization of cellular responses that are essential for immune functions.

  14. The Janus face of death receptor signalling during tumour immunoediting.

    Directory of Open Access Journals (Sweden)

    Eimear O' Reilly

    2016-10-01

    Full Text Available Cancer immune-surveillance is essential for the inhibition of carcinogenesis. Malignantly transformed cells can be recognised by both the innate and adaptive immune systems through different mechanisms. Immune effector cells induce extrinsic cell death in the identified tumour cells by expressing death ligand cytokines of the tumour necrosis factor ligand family. However, some tumour cells can escape immune elimination and progress. Acquisition of resistance to the death-ligand induced apoptotic pathway can be obtained through cleavage of effector-cell expressed death-ligands into a poorly active form, mutations or silencing of the death receptors or overexpression of decoy receptors and pro-survival proteins. Although the immune system is highly effective in the elimination of malignantly transformed cells, abnormal/ dysfunctional death-ligand signalling curbs its cytotoxicity. Moreover, death receptors can also transmit pro-survival and pro-migratory signals. Consequently, dysfunctional death receptor-mediated apoptosis/necroptosis signalling does not only give a passive resistance against cell death, but actively drives tumour cell motility, invasion and contributes to consequent metastasis. This dual contribution of the death ligand-death receptor signalling in both the early, elimination phase and then in the late, escape phase of the tumour immunoediting process is discussed in this review. Death receptor agonists still hold potential for cancer therapy since they can execute the tumour-eliminating immune-effector function even in the absence of activation of the immune system against the tumour. The opportunities and challenges of developing death receptor agonists into effective cancer therapeutics are also discussed.

  15. Mechanism of inhibition of growth hormone receptor signaling by suppressor of cytokine signaling proteins

    DEFF Research Database (Denmark)

    Hansen, J A; Lindberg, K; Hilton, D J

    1999-01-01

    In this study we have investigated the role of suppressor of cytokine signaling (SOCS) proteins in GH receptor-mediated signaling. GH-induced transcription was inhibited by SOCS-1 and SOCS-3, while SOCS-2 and cytokine inducible SH2-containing protein (CIS) had no effect By using chimeric SOCS pro...

  16. Diverse FGF receptor signaling controls astrocyte specification and proliferation

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Kyungjun [School of Life Sciences, Gwangju Institute of Science and Technology, Oryong-dong, Buk-gu, Gwangju 500-712 (Korea, Republic of); Song, Mi-Ryoung, E-mail: msong@gist.ac.kr [School of Life Sciences, Gwangju Institute of Science and Technology, Oryong-dong, Buk-gu, Gwangju 500-712 (Korea, Republic of); Bioimaging Research Center and Cell Dynamics Research Center, Gwangju Institute of Science and Technology, Oryong-dong, Buk-gu, Gwangju 500-712 (Korea, Republic of)

    2010-05-07

    During CNS development, pluripotency neuronal progenitor cells give rise in succession to neurons and glia. Fibroblast growth factor-2 (FGF-2), a major signal that maintains neural progenitors in the undifferentiated state, is also thought to influence the transition from neurogenesis to gliogenesis. Here we present evidence that FGF receptors and underlying signaling pathways transmit the FGF-2 signals that regulate astrocyte specification aside from its mitogenic activity. Application of FGF-2 to cortical progenitors suppressed neurogenesis whereas treatment with an FGFR antagonist in vitro promoted neurogenesis. Introduction of chimeric FGFRs with mutated tyrosine residues into cortical progenitors and drug treatments to specifically block individual downstream signaling pathways revealed that the overall activity of FGFR rather than individual autophosphorylation sites is important for delivering signals for glial specification. In contrast, a signal for cell proliferation by FGFR was mainly delivered by MAPK pathway. Together our findings indicate that FGFR activity promotes astrocyte specification in the developing CNS.

  17. Diverse FGF receptor signaling controls astrocyte specification and proliferation

    International Nuclear Information System (INIS)

    Kang, Kyungjun; Song, Mi-Ryoung

    2010-01-01

    During CNS development, pluripotency neuronal progenitor cells give rise in succession to neurons and glia. Fibroblast growth factor-2 (FGF-2), a major signal that maintains neural progenitors in the undifferentiated state, is also thought to influence the transition from neurogenesis to gliogenesis. Here we present evidence that FGF receptors and underlying signaling pathways transmit the FGF-2 signals that regulate astrocyte specification aside from its mitogenic activity. Application of FGF-2 to cortical progenitors suppressed neurogenesis whereas treatment with an FGFR antagonist in vitro promoted neurogenesis. Introduction of chimeric FGFRs with mutated tyrosine residues into cortical progenitors and drug treatments to specifically block individual downstream signaling pathways revealed that the overall activity of FGFR rather than individual autophosphorylation sites is important for delivering signals for glial specification. In contrast, a signal for cell proliferation by FGFR was mainly delivered by MAPK pathway. Together our findings indicate that FGFR activity promotes astrocyte specification in the developing CNS.

  18. Signalling through C-type lectin receptors: shaping immune responses

    NARCIS (Netherlands)

    Geijtenbeek, Teunis B. H.; Gringhuis, Sonja I.

    2009-01-01

    C-type lectin receptors (CLRs) expressed by dendritic cells are crucial for tailoring immune responses to pathogens. Following pathogen binding, CLRs trigger distinct signalling pathways that induce the expression of specific cytokines which determine T cell polarization fates. Some CLRs can induce

  19. Role of Estrogen Receptor Signaling in Breast Cancer Metastasis

    International Nuclear Information System (INIS)

    Roy, S.S.; Vadlamudi, R.K.

    2012-01-01

    Metastatic breast cancer is a life-threatening stage of cancer and is the leading cause of death in advanced breast cancer patients. Estrogen signaling and the estrogen receptor (ER) are implicated in breast cancer progression, and the majority of the human breast cancers start out as estrogen dependent. Accumulating evidence suggests that ER signaling is complex, involving coregulatory proteins and extranuclear actions. ER-coregualtory proteins are tightly regulated under normal conditions with miss expression primarily reported in cancer. Deregulation of ER coregualtors or ER extranuclear signaling has potential to promote metastasis in ER-positive breast cancer cells. This review summarizes the emerging role of ER signaling in promoting metastasis of breast cancer cells, discusses the molecular mechanisms by which ER signaling contributes to metastasis, and explores possible therapeutic targets to block ER-driven metastasis

  20. Differential Regulation of Hippocampal IGF-1-Associated Signaling Proteins by Dietary Restriction in Aging Mouse.

    Science.gov (United States)

    Hadem, Ibanylla Kynjai Hynniewta; Sharma, Ramesh

    2017-08-01

    Time-dependent alterations in several biological processes of an organism may be characterized as aging. One of the effects of aging is the decline in cognitive functions. Dietary restriction (DR), an intervention where the consumption of food is lessened but without malnutrition, is a well-established mechanism that has a wide range of important outcomes including improved health span, delayed aging, and extension of lifespan of various species. It also plays a beneficial role in protecting against age-dependent deterioration of cognitive functions, and has neuroprotective properties against neurodegenerative diseases. Insulin-like growth factor (IGF)-1 plays an important role in the regulation of cellular and tissue functions, and relating to the aging process the most important pathway of IGF-1 is the phosphatidylinositol 3-kinase (PI3K) and protein kinase B (Akt/PKB) signaling cascade. Although many have studied the changes in the level of IGF-1 and its effect on neural proliferation, the downstream signaling proteins have not been fully elucidated. Hence in the present investigation, the IGF-1 gene expression and the normal endogenous levels of IGF1R (IGF-1 receptor), PI3K, Akt, pAkt, and pFoxO in the hippocampus of young, adult, and old mice were determined using real-time PCR and Western blot analyses. The effects of DR on these protein levels were also studied. Results showed a decrease in the levels of IGF-1, IGF1R, PI3K, and pAkt, while pFoxO level increased with respect to age. Under DR, these protein levels are maintained in adult mice, but old mice displayed diminished expression levels of these proteins as compared to ad libitum-fed mice. Maintenance of PI3K/Akt pathway results in the phosphorylation of FoxOs, necessary for the enhancement of neural proliferation and survival in adult mice. The down-regulation of IGF-I signaling, as observed in old mice, leads to increasing the activity of FoxO factors that may be important for the neuroprotective

  1. Neurotransmitter receptors as signaling platforms in anterior pituitary cells

    Czech Academy of Sciences Publication Activity Database

    Zemková, Hana; Stojilkovic, S. S.

    2018-01-01

    Roč. 463, C (2018), s. 49-64 ISSN 0303-7207 R&D Projects: GA ČR(CZ) GA16-12695S; GA ČR(CZ) GBP304/12/G069; GA MŠk(CZ) LQ1604; GA MŠk(CZ) ED1.1.00/02.0109 Institutional support: RVO:67985823 Keywords : pituitary * ligand-gated receptor channels * G protein -coupled receptors * neurotransmitters * action potentials * calcium signaling * hormone secretion Subject RIV: FH - Neurology OBOR OECD: Neurosciences (including psychophysiology Impact factor: 3.754, year: 2016

  2. Physiological Signaling and Structure of the HGF Receptor MET

    Directory of Open Access Journals (Sweden)

    Gianluca Baldanzi

    2014-12-01

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

  3. Dual Targeting of the Insulin-Like Growth Factor and Collateral Pathways in Cancer: Combating Drug Resistance

    Energy Technology Data Exchange (ETDEWEB)

    Ludwig, Joseph A., E-mail: jaludwig@mdanderson.org; Lamhamedi-Cherradi, Salah-Eddine [Departments of Sarcoma Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030 (United States); Lee, Ho-Young [Departments of Thoracic Head & Neck Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030 (United States); Naing, Aung [Investigational Cancer Therapeutics, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030 (United States); Benjamin, Robert [Departments of Sarcoma Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030 (United States)

    2011-07-26

    The insulin-like growth factor pathway, regulated by a complex interplay of growth factors, cognate receptors, and binding proteins, is critically important for many of the hallmarks of cancer such as oncogenesis, cell division, growth, and antineoplastic resistance. Naturally, a number of clinical trials have sought to directly abrogate insulin-like growth factor receptor 1 (IGF-1R) function and/or indirectly mitigate its downstream mediators such as mTOR, PI3K, MAPK, and others under the assumption that such therapeutic interventions would provide clinical benefit, demonstrable by impaired tumor growth as well as prolonged progression-free and overall survival for patients. Though a small subset of patients enrolled within phase I or II clinical trials revealed dramatic clinical response to IGF-1R targeted therapies (most using monoclonal antibodies to IGF-1R), in toto, the anticancer effect has been underwhelming and unsustained, as even those with marked clinical responses seem to rapidly acquire resistance to IGF-1R targeted agents when used alone through yet to be identified mechanisms. As the IGF-1R receptor is just one of many that converge upon common intracellular signaling cascades, it is likely that effective IGF-1R targeting must occur in parallel with blockade of redundant signaling paths. Herein, we present the rationale for dual targeting of IGF-1R and other signaling molecules as an effective strategy to combat acquired drug resistance by carcinomas and sarcomas.

  4. Dual Targeting of the Insulin-Like Growth Factor and Collateral Pathways in Cancer: Combating Drug Resistance

    International Nuclear Information System (INIS)

    Ludwig, Joseph A.; Lamhamedi-Cherradi, Salah-Eddine; Lee, Ho-Young; Naing, Aung; Benjamin, Robert

    2011-01-01

    The insulin-like growth factor pathway, regulated by a complex interplay of growth factors, cognate receptors, and binding proteins, is critically important for many of the hallmarks of cancer such as oncogenesis, cell division, growth, and antineoplastic resistance. Naturally, a number of clinical trials have sought to directly abrogate insulin-like growth factor receptor 1 (IGF-1R) function and/or indirectly mitigate its downstream mediators such as mTOR, PI3K, MAPK, and others under the assumption that such therapeutic interventions would provide clinical benefit, demonstrable by impaired tumor growth as well as prolonged progression-free and overall survival for patients. Though a small subset of patients enrolled within phase I or II clinical trials revealed dramatic clinical response to IGF-1R targeted therapies (most using monoclonal antibodies to IGF-1R), in toto, the anticancer effect has been underwhelming and unsustained, as even those with marked clinical responses seem to rapidly acquire resistance to IGF-1R targeted agents when used alone through yet to be identified mechanisms. As the IGF-1R receptor is just one of many that converge upon common intracellular signaling cascades, it is likely that effective IGF-1R targeting must occur in parallel with blockade of redundant signaling paths. Herein, we present the rationale for dual targeting of IGF-1R and other signaling molecules as an effective strategy to combat acquired drug resistance by carcinomas and sarcomas

  5. Dual Targeting of the Insulin-Like Growth Factor and Collateral Pathways in Cancer: Combating Drug Resistance

    Directory of Open Access Journals (Sweden)

    Aung Naing

    2011-07-01

    Full Text Available The insulin-like growth factor pathway, regulated by a complex interplay of growth factors, cognate receptors, and binding proteins, is critically important for many of the hallmarks of cancer such as oncogenesis, cell division, growth, and antineoplastic resistance. Naturally, a number of clinical trials have sought to directly abrogate insulin-like growth factor receptor 1 (IGF-1R function and/or indirectly mitigate its downstream mediators such as mTOR, PI3K, MAPK, and others under the assumption that such therapeutic interventions would provide clinical benefit, demonstrable by impaired tumor growth as well as prolonged progression-free and overall survival for patients. Though a small subset of patients enrolled within phase I or II clinical trials revealed dramatic clinical response to IGF-1R targeted therapies (most using monoclonal antibodies to IGF-1R, in toto, the anticancer effect has been underwhelming and unsustained, as even those with marked clinical responses seem to rapidly acquire resistance to IGF-1R targeted agents when used alone through yet to be identified mechanisms. As the IGF-1R receptor is just one of many that converge upon common intracellular signaling cascades, it is likely that effective IGF-1R targeting must occur in parallel with blockade of redundant signaling paths. Herein, we present the rationale for dual targeting of IGF-1R and other signaling molecules as an effective strategy to combat acquired drug resistance by carcinomas and sarcomas.

  6. CD147 is a signaling receptor for cyclophilin B.

    Science.gov (United States)

    Yurchenko, V; O'Connor, M; Dai, W W; Guo, H; Toole, B; Sherry, B; Bukrinsky, M

    2001-11-09

    Cyclophilins A and B (CyPA and CyPB) are cyclosporin A binding proteins that can be secreted in response to inflammatory stimuli. We recently identified CD147 as a cell-surface receptor for CyPA and demonstrated that CD147 is an essential component in the CyPA-initiated signaling cascade that culminates in ERK activation and chemotaxis. Here we demonstrate that CD147 also serves as a receptor for CyPB. CyPB induced Ca(2+) flux and chemotaxis of CD147-transfected, but not control, CHO cells, and the chemotactic response of primary human neutrophils to CyPB was blocked by antibodies to CD147. These results suggest that CD147 serves as a receptor for extracellular cyclophilins. Copyright 2001 Academic Press.

  7. Nuclear receptor TLX inhibits TGF-β signaling in glioblastoma

    Energy Technology Data Exchange (ETDEWEB)

    Johansson, Erik; Zhai, Qiwei [Sahlgrenska Cancer Center at the Sahlgrenska Academy, University of Gothenburg, Box 425, SE 405 30 Gothenburg (Sweden); Zeng, Zhao-jun [Sahlgrenska Cancer Center at the Sahlgrenska Academy, University of Gothenburg, Box 425, SE 405 30 Gothenburg (Sweden); Molecular Biology Research Center, School of Life Sciences, Central South University, 110, Xiangya Road, Changsha, Hunan 410078 (China); Yoshida, Takeshi [Sahlgrenska Cancer Center at the Sahlgrenska Academy, University of Gothenburg, Box 425, SE 405 30 Gothenburg (Sweden); Funa, Keiko, E-mail: keiko.funa@gu.se [Sahlgrenska Cancer Center at the Sahlgrenska Academy, University of Gothenburg, Box 425, SE 405 30 Gothenburg (Sweden)

    2016-05-01

    TLX (also called NR2E1) is an orphan nuclear receptor that maintains stemness of neuronal stem cells. TLX is highly expressed in the most malignant form of glioma, glioblastoma multiforme (GBM), and is important for the proliferation and maintenance of the stem/progenitor cells of the tumor. Transforming Growth Factor-β (TGF-β) is a cytokine regulating many different cellular processes such as differentiation, migration, adhesion, cell death and proliferation. TGF-β has an important function in cancer where it can work as either a tumor suppressor or oncogene, depending on the cancer type and stage of tumor development. Since glioblastoma often have dysfunctional TGF-β signaling we wanted to find out if there is any interaction between TLX and TGF-β in glioblastoma cells. We demonstrate that knockdown of TLX enhances the canonical TGF-β signaling response in glioblastoma cell lines. TLX physically interacts with and stabilizes Smurf1, which can ubiquitinate and target TGF-β receptor II for degradation, whereas knockdown of TLX leads to stabilization of TGF-β receptor II, increased nuclear translocation of Smad2/3 and enhanced expression of TGF-β target genes. The interaction between TLX and TGF-β may play an important role in the regulation of proliferation and tumor-initiating properties of glioblastoma cells. - Highlights: • TLX knockdown enhances TGF-β dependent Smad signaling in glioblastoma cells • TLX knockdown increases the protein level of TGF-β receptor II. • TLX stabilizes and retains Smurf1 in the cytoplasm. • TLX enhances Smurf1-dependent ubiquitination and degradation of TGF-β receptor II.

  8. Nuclear receptor TLX inhibits TGF-β signaling in glioblastoma

    International Nuclear Information System (INIS)

    Johansson, Erik; Zhai, Qiwei; Zeng, Zhao-jun; Yoshida, Takeshi; Funa, Keiko

    2016-01-01

    TLX (also called NR2E1) is an orphan nuclear receptor that maintains stemness of neuronal stem cells. TLX is highly expressed in the most malignant form of glioma, glioblastoma multiforme (GBM), and is important for the proliferation and maintenance of the stem/progenitor cells of the tumor. Transforming Growth Factor-β (TGF-β) is a cytokine regulating many different cellular processes such as differentiation, migration, adhesion, cell death and proliferation. TGF-β has an important function in cancer where it can work as either a tumor suppressor or oncogene, depending on the cancer type and stage of tumor development. Since glioblastoma often have dysfunctional TGF-β signaling we wanted to find out if there is any interaction between TLX and TGF-β in glioblastoma cells. We demonstrate that knockdown of TLX enhances the canonical TGF-β signaling response in glioblastoma cell lines. TLX physically interacts with and stabilizes Smurf1, which can ubiquitinate and target TGF-β receptor II for degradation, whereas knockdown of TLX leads to stabilization of TGF-β receptor II, increased nuclear translocation of Smad2/3 and enhanced expression of TGF-β target genes. The interaction between TLX and TGF-β may play an important role in the regulation of proliferation and tumor-initiating properties of glioblastoma cells. - Highlights: • TLX knockdown enhances TGF-β dependent Smad signaling in glioblastoma cells • TLX knockdown increases the protein level of TGF-β receptor II. • TLX stabilizes and retains Smurf1 in the cytoplasm. • TLX enhances Smurf1-dependent ubiquitination and degradation of TGF-β receptor II.

  9. The role of insulin receptor signaling in the brain.

    Science.gov (United States)

    Plum, Leona; Schubert, Markus; Brüning, Jens C

    2005-03-01

    The insulin receptor (IR) is expressed in various regions of the developing and adult brain, and its functions have become the focus of recent research. Insulin enters the central nervous system (CNS) through the blood-brain barrier by receptor-mediated transport to regulate food intake, sympathetic activity and peripheral insulin action through the inhibition of hepatic gluconeogenesis and reproductive endocrinology. On a molecular level, some of the effects of insulin converge with those of the leptin signaling machinery at the point of activation of phosphatidylinositol 3-kinase (PI3K), resulting in the regulation of ATP-dependent potassium channels. Furthermore, insulin inhibits neuronal apoptosis via activation of protein kinase B in vitro, and it regulates phosphorylation of tau, metabolism of the amyloid precursor protein and clearance of beta-amyloid from the brain in vivo. These findings indicate that neuronal IR signaling has a direct role in the link between energy homeostasis, reproduction and the development of neurodegenerative diseases.

  10. Assembly of Oligomeric Death Domain Complexes during Toll Receptor Signaling*

    OpenAIRE

    Moncrieffe, Martin C.; Grossmann, J. Günter; Gay, Nicholas J.

    2008-01-01

    The Drosophila Toll receptor is activated by the endogenous protein ligand Spätzle in response to microbial stimuli in immunity and spatial cues during embryonic development. Downstream signaling is mediated by the adaptor proteins Tube, the kinase Pelle, and the Drosophila homologue of myeloid differentiation primary response protein (dMyD88). Here we have characterized heterodimeric (dMyD88-Tube) and heterotrimeric (dMyD88-Tube-Pelle) death domain complexes. We show ...

  11. Clinical significance of proliferation, apoptosis and senescence of nasopharyngeal cells by the simultaneously blocking EGF, IGF-1 receptors and Bcl-xl genes

    International Nuclear Information System (INIS)

    Dai, Guodong; Peng, Tao; Zhou, Xuhong; Zhu, Jun; Kong, Zhihua; Ma, Li; Xiong, Zhi; Yuan, Yulin

    2013-01-01

    Highlight: •Construction of shRNA segments expression vectors is valid by the investigation of RT-PCR for IGF1R, EGFR and Bcl-xl mRNA and protein expression. •Studies have suggested that the vectors in blocking these genes of the growth factor receptors and anti- apoptosis is capable of breaking the balance of tumor growth so that tumor trend apoptosis and senescence. •Simultaneously blocking multiple genes that are abnormally expressed may be more effective in treating cancer cells than silencing a single gene. -- Abstract: Background: In previous work, we constructed short hairpin RNA (shRNA) expression plasmids that targeted human EGF and IGF-1 receptors messenger RNA, respectively, and demonstrated that these vectors could induce apoptosis of human nasopharyngeal cell lines (CNE2) and inhibit ligand-induced pAkt and pErk activation. Method: We have constructed multiple shRNA expression vectors of targeting EGFR, IGF1R and Bcl-xl, which were transfected to the CNE2 cells. The mRNA expression was assessed by RT-PCR. The growth of the cells, cell cycle progression, apoptosis of the cells, senescent tumor cells and the proteins of EGFR, IGF1R and Bcl-xl were analyzed by MTT, flow cytometry, cytochemical therapy or Western blot. Results: In group of simultaneously blocking EGFR, IGF1R and Bcl-xl genes, the mRNA of EGFR, IGF1R and Bcl-xl expression was decreased by (66.66 ± 3.42)%, (73.97 ± 2.83)% and (64.79 ± 2.83)%, and the protein expressions was diminished to (67.69 ± 4.02)%, (74.32 ± 2.30)%, and (60.00 ± 3.34)%, respectively. Meanwhile, the cell apoptosis increased by 65.32 ± 0.18%, 65.16 ± 0.25% and 55.47 ± 0.45%, and senescent cells increased by 1.42 ± 0.15%, 2.26 ± 0.15% and 3.22 ± 0.15% in the second, third and fourth day cultures, respectively. Conclusions: Simultaneously blocking EGFR, IGF1R and Bcl-xl genes is capable of altering the balance between proliferating versus apoptotic and senescent cells in the favor of both of apoptosis and

  12. Clinical significance of proliferation, apoptosis and senescence of nasopharyngeal cells by the simultaneously blocking EGF, IGF-1 receptors and Bcl-xl genes

    Energy Technology Data Exchange (ETDEWEB)

    Dai, Guodong [Anatomy and Embryology, Wuhan University School of Medicine, Wuhan, Hubei 430071 (China); Peng, Tao; Zhou, Xuhong [Department of Otolaryngology-Head and Neck Surgery, Zhongnan Hospital of Wuhan University, Wuhan 430071 (China); Zhu, Jun; Kong, Zhihua; Ma, Li; Xiong, Zhi [Anatomy and Embryology, Wuhan University School of Medicine, Wuhan, Hubei 430071 (China); Yuan, Yulin, E-mail: yuanyulin19620120@126.com [Anatomy and Embryology, Wuhan University School of Medicine, Wuhan, Hubei 430071 (China)

    2013-11-01

    Highlight: •Construction of shRNA segments expression vectors is valid by the investigation of RT-PCR for IGF1R, EGFR and Bcl-xl mRNA and protein expression. •Studies have suggested that the vectors in blocking these genes of the growth factor receptors and anti- apoptosis is capable of breaking the balance of tumor growth so that tumor trend apoptosis and senescence. •Simultaneously blocking multiple genes that are abnormally expressed may be more effective in treating cancer cells than silencing a single gene. -- Abstract: Background: In previous work, we constructed short hairpin RNA (shRNA) expression plasmids that targeted human EGF and IGF-1 receptors messenger RNA, respectively, and demonstrated that these vectors could induce apoptosis of human nasopharyngeal cell lines (CNE2) and inhibit ligand-induced pAkt and pErk activation. Method: We have constructed multiple shRNA expression vectors of targeting EGFR, IGF1R and Bcl-xl, which were transfected to the CNE2 cells. The mRNA expression was assessed by RT-PCR. The growth of the cells, cell cycle progression, apoptosis of the cells, senescent tumor cells and the proteins of EGFR, IGF1R and Bcl-xl were analyzed by MTT, flow cytometry, cytochemical therapy or Western blot. Results: In group of simultaneously blocking EGFR, IGF1R and Bcl-xl genes, the mRNA of EGFR, IGF1R and Bcl-xl expression was decreased by (66.66 ± 3.42)%, (73.97 ± 2.83)% and (64.79 ± 2.83)%, and the protein expressions was diminished to (67.69 ± 4.02)%, (74.32 ± 2.30)%, and (60.00 ± 3.34)%, respectively. Meanwhile, the cell apoptosis increased by 65.32 ± 0.18%, 65.16 ± 0.25% and 55.47 ± 0.45%, and senescent cells increased by 1.42 ± 0.15%, 2.26 ± 0.15% and 3.22 ± 0.15% in the second, third and fourth day cultures, respectively. Conclusions: Simultaneously blocking EGFR, IGF1R and Bcl-xl genes is capable of altering the balance between proliferating versus apoptotic and senescent cells in the favor of both of apoptosis and

  13. Peroxisome Proliferator-Activated Receptor and Vitamin D Receptor Signaling Pathways in Cancer Cells

    Directory of Open Access Journals (Sweden)

    Yasuko Kitagishi

    2013-10-01

    Full Text Available Peroxisome proliferator-activated receptors (PPARs are members of the superfamily of nuclear hormone receptors, which respond to specific ligands such as polyunsaturated fatty acids by altering gene expression. Three subtypes of this receptor have been discovered, each evolving to achieve different biological functions. Like other nuclear receptors, the transcriptional activity of PPARs is affected not only by ligand-stimulation, but also by cross-talk with other molecules. For example, both PPARs and the RXRs are ligand-activated transcription factors that coordinately regulate gene expression. In addition, PPARs and vitamin D receptor (VDR signaling pathways regulate a multitude of genes that are of importance for cellular functions including cell proliferation and cell differentiation. Interaction of the PPARs and VDR signaling pathways has been shown at the level of molecular cross-regulation of their transcription factor. A variety of ligands influencing the PPARs and VDR signaling pathways have been shown to reveal chemopreventive potential by mediating tumor suppressive activities in human cancers. Use of these compounds may represent a potential novel strategy to prevent cancers. This review summarizes the roles of the PPARs and the VDR in pathogenesis and progression of cancer.

  14. Peroxisome Proliferator-Activated Receptor and Vitamin D Receptor Signaling Pathways in Cancer Cells

    Energy Technology Data Exchange (ETDEWEB)

    Matsuda, Satoru, E-mail: smatsuda@cc.nara-wu.ac.jp; Kitagishi, Yasuko [Department of Food Science and Nutrition, Nara Women’s University, Kita-Uoya Nishimachi, Nara 630-8506 (Japan)

    2013-10-21

    Peroxisome proliferator-activated receptors (PPARs) are members of the superfamily of nuclear hormone receptors, which respond to specific ligands such as polyunsaturated fatty acids by altering gene expression. Three subtypes of this receptor have been discovered, each evolving to achieve different biological functions. Like other nuclear receptors, the transcriptional activity of PPARs is affected not only by ligand-stimulation, but also by cross-talk with other molecules. For example, both PPARs and the RXRs are ligand-activated transcription factors that coordinately regulate gene expression. In addition, PPARs and vitamin D receptor (VDR) signaling pathways regulate a multitude of genes that are of importance for cellular functions including cell proliferation and cell differentiation. Interaction of the PPARs and VDR signaling pathways has been shown at the level of molecular cross-regulation of their transcription factor. A variety of ligands influencing the PPARs and VDR signaling pathways have been shown to reveal chemopreventive potential by mediating tumor suppressive activities in human cancers. Use of these compounds may represent a potential novel strategy to prevent cancers. This review summarizes the roles of the PPARs and the VDR in pathogenesis and progression of cancer.

  15. Peroxisome Proliferator-Activated Receptor and Vitamin D Receptor Signaling Pathways in Cancer Cells

    International Nuclear Information System (INIS)

    Matsuda, Satoru; Kitagishi, Yasuko

    2013-01-01

    Peroxisome proliferator-activated receptors (PPARs) are members of the superfamily of nuclear hormone receptors, which respond to specific ligands such as polyunsaturated fatty acids by altering gene expression. Three subtypes of this receptor have been discovered, each evolving to achieve different biological functions. Like other nuclear receptors, the transcriptional activity of PPARs is affected not only by ligand-stimulation, but also by cross-talk with other molecules. For example, both PPARs and the RXRs are ligand-activated transcription factors that coordinately regulate gene expression. In addition, PPARs and vitamin D receptor (VDR) signaling pathways regulate a multitude of genes that are of importance for cellular functions including cell proliferation and cell differentiation. Interaction of the PPARs and VDR signaling pathways has been shown at the level of molecular cross-regulation of their transcription factor. A variety of ligands influencing the PPARs and VDR signaling pathways have been shown to reveal chemopreventive potential by mediating tumor suppressive activities in human cancers. Use of these compounds may represent a potential novel strategy to prevent cancers. This review summarizes the roles of the PPARs and the VDR in pathogenesis and progression of cancer

  16. DMPD: Is HIV infection a TNF receptor signalling-driven disease? [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 18178131 Is HIV infection a TNF receptor signalling-driven disease? Herbein G, Khan... KA. Trends Immunol. 2008 Feb;29(2):61-7. (.png) (.svg) (.html) (.csml) Show Is HIV infection a TNF receptor signalling-driven dise...ase? PubmedID 18178131 Title Is HIV infection a TNF receptor signalling-driven diseas

  17. DMPD: TGF-beta signaling from receptors to the nucleus. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 10611754 TGF-beta signaling from receptors to the nucleus. Roberts AB. Microbes Inf...ect. 1999 Dec;1(15):1265-73. (.png) (.svg) (.html) (.csml) Show TGF-beta signaling from receptors to the nucleus.... PubmedID 10611754 Title TGF-beta signaling from receptors to the nucleus. Authors Roberts AB. Publicat

  18. DMPD: Signals and receptors involved in recruitment of inflammatory cells. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 7744810 Signals and receptors involved in recruitment of inflammatory cells. Ben-Ba...ow Signals and receptors involved in recruitment of inflammatory cells. PubmedID 7744810 Title Signals and receptors involved in recr...uitment of inflammatory cells. Authors Ben-Baruch A, Mic

  19. DMPD: Lysophospholipid receptors: signaling and biology. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 15189145 Lysophospholipid receptors: signaling and biology. Ishii I, Fukushima N, Y...e X, Chun J. Annu Rev Biochem. 2004;73:321-54. (.png) (.svg) (.html) (.csml) Show Lysophospholipid receptors...: signaling and biology. PubmedID 15189145 Title Lysophospholipid receptors: signaling and biology. Authors

  20. 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.

  1. Design principles of nuclear receptor signaling: how complex networking improves signal transduction

    Science.gov (United States)

    Kolodkin, Alexey N; Bruggeman, Frank J; Plant, Nick; Moné, Martijn J; Bakker, Barbara M; Campbell, Moray J; van Leeuwen, Johannes P T M; Carlberg, Carsten; Snoep, Jacky L; Westerhoff, Hans V

    2010-01-01

    The topology of nuclear receptor (NR) signaling is captured in a systems biological graphical notation. This enables us to identify a number of ‘design' aspects of the topology of these networks that might appear unnecessarily complex or even functionally paradoxical. In realistic kinetic models of increasing complexity, calculations show how these features correspond to potentially important design principles, e.g.: (i) cytosolic ‘nuclear' receptor may shuttle signal molecules to the nucleus, (ii) the active export of NRs may ensure that there is sufficient receptor protein to capture ligand at the cytoplasmic membrane, (iii) a three conveyor belts design dissipating GTP-free energy, greatly aids response, (iv) the active export of importins may prevent sequestration of NRs by importins in the nucleus and (v) the unspecific nature of the nuclear pore may ensure signal-flux robustness. In addition, the models developed are suitable for implementation in specific cases of NR-mediated signaling, to predict individual receptor functions and differential sensitivity toward physiological and pharmacological ligands. PMID:21179018

  2. Differential modulation of Beta-adrenergic receptor signaling by trace amine-associated receptor 1 agonists.

    Directory of Open Access Journals (Sweden)

    Gunnar Kleinau

    Full Text Available Trace amine-associated receptors (TAAR are rhodopsin-like G-protein-coupled receptors (GPCR. TAAR are involved in modulation of neuronal, cardiac and vascular functions and they are potentially linked with neurological disorders like schizophrenia and Parkinson's disease. Subtype TAAR1, the best characterized TAAR so far, is promiscuous for a wide set of ligands and is activated by trace amines tyramine (TYR, phenylethylamine (PEA, octopamine (OA, but also by thyronamines, dopamine, and psycho-active drugs. Unfortunately, effects of trace amines on signaling of the two homologous β-adrenergic receptors 1 (ADRB1 and 2 (ADRB2 have not been clarified yet in detail. We, therefore, tested TAAR1 agonists TYR, PEA and OA regarding their effects on ADRB1/2 signaling by co-stimulation studies. Surprisingly, trace amines TYR and PEA are partial allosteric antagonists at ADRB1/2, whereas OA is a partial orthosteric ADRB2-antagonist and ADRB1-agonist. To specify molecular reasons for TAAR1 ligand promiscuity and for observed differences in signaling effects on particular aminergic receptors we compared TAAR, tyramine (TAR octopamine (OAR, ADRB1/2 and dopamine receptors at the structural level. We found especially for TAAR1 that the remarkable ligand promiscuity is likely based on high amino acid similarity in the ligand-binding region compared with further aminergic receptors. On the other hand few TAAR specific properties in the ligand-binding site might determine differences in ligand-induced effects compared to ADRB1/2. Taken together, this study points to molecular details of TAAR1-ligand promiscuity and identified specific trace amines as allosteric or orthosteric ligands of particular β-adrenergic receptor subtypes.

  3. Phosphorylation site dynamics of early T-cell receptor signaling

    DEFF Research Database (Denmark)

    Chylek, Lily A; Akimov, Vyacheslav; Dengjel, Jörn

    2014-01-01

    In adaptive immune responses, T-cell receptor (TCR) signaling impacts multiple cellular processes and results in T-cell differentiation, proliferation, and cytokine production. Although individual protein-protein interactions and phosphorylation events have been studied extensively, we lack...... that diverse dynamic patterns emerge within seconds. We detected phosphorylation dynamics as early as 5 s and observed widespread regulation of key TCR signaling proteins by 30 s. Development of a computational model pointed to the presence of novel regulatory mechanisms controlling phosphorylation of sites...... a systems-level understanding of how these components cooperate to control signaling dynamics, especially during the crucial first seconds of stimulation. Here, we used quantitative proteomics to characterize reshaping of the T-cell phosphoproteome in response to TCR/CD28 co-stimulation, and found...

  4. Tyrosine Phosphorylation in Toll-Like Receptor Signaling

    Science.gov (United States)

    Chattopadhyay, Saurabh; Sen, Ganes C.

    2014-01-01

    There is a wealth of knowledge about how different Ser/Thr protein kinases participate in Toll-like receptor (TLR) signaling. In many cases, we know the identities of the Ser/Thr residues of various components of the TLR-signaling pathways that are phosphorylated, the functional consequences of the phosphorylation and the responsible protein kinases. In contrast, the analysis of Tyr-phosphorylation of TLRs and their signaling proteins is currently incomplete, because several existing analyses are not systematic or they do not rely on robust experimental data. Nevertheless, it is clear that many TLRs require, for signaling, ligand-dependent phosphorylation of specific Tyr residues in their cytoplasmic domains; the list includes TLR2, TLR3, TLR4, TLR5, TLR8 and TLR9. In this article, we discuss the current status of knowledge on the effect of Tyr-phosphorylation of TLRs and their signaling proteins on their biochemical and biological functions, the possible identities of the relevant protein tyrosine kinases (PTKs) and the nature of regulations of PTK-mediated activation of TLR signaling pathways. PMID:25022196

  5. Postoperative ileus involves interleukin-1 receptor signaling in enteric glia.

    Science.gov (United States)

    Stoffels, Burkhard; Hupa, Kristof Johannes; Snoek, Susanne A; van Bree, Sjoerd; Stein, Kathy; Schwandt, Timo; Vilz, Tim O; Lysson, Mariola; Veer, Cornelis Van't; Kummer, Markus P; Hornung, Veit; Kalff, Joerg C; de Jonge, Wouter J; Wehner, Sven

    2014-01-01

    Postoperative ileus (POI) is a common consequence of abdominal surgery that increases the risk of postoperative complications and morbidity. We investigated the cellular mechanisms and immune responses involved in the pathogenesis of POI. We studied a mouse model of POI in which intestinal manipulation leads to inflammation of the muscularis externa and disrupts motility. We used C57BL/6 (control) mice as well as mice deficient in Toll-like receptors (TLRs) and cytokine signaling components (TLR-2(-/-), TLR-4(-/-), TLR-2/4(-/-), MyD88(-/-), MyD88/TLR adaptor molecule 1(-/-), interleukin-1 receptor [IL-1R1](-/-), and interleukin (IL)-18(-/-) mice). Bone marrow transplantation experiments were performed to determine which cytokine receptors and cell types are involved in the pathogenesis of POI. Development of POI did not require TLRs 2, 4, or 9 or MyD88/TLR adaptor molecule 2 but did require MyD88, indicating a role for IL-1R1. IL-1R1(-/-) mice did not develop POI; however, mice deficient in IL-18, which also signals via MyD88, developed POI. Mice given injections of an IL-1 receptor antagonist (anakinra) or antibodies to deplete IL-1α and IL-1β before intestinal manipulation were protected from POI. Induction of POI activated the inflammasome in muscularis externa tissues of C57BL6 mice, and IL-1α and IL-1β were released in ex vivo organ bath cultures. In bone marrow transplantation experiments, the development of POI required activation of IL-1 receptor in nonhematopoietic cells. IL-1R1 was expressed by enteric glial cells in the myenteric plexus layer, and cultured primary enteric glia cells expressed IL-6 and the chemokine monocyte chemotactic protein 1 in response to IL-1β stimulation. Immunohistochemical analysis of human small bowel tissue samples confirmed expression of IL-1R1 in the ganglia of the myenteric plexus. IL-1 signaling, via IL-1R1 and MyD88, is required for development of POI after intestinal manipulation in mice. Agents that interfere with

  6. Assembly of Oligomeric Death Domain Complexes during Toll Receptor Signaling*

    Science.gov (United States)

    Moncrieffe, Martin C.; Grossmann, J. Günter; Gay, Nicholas J.

    2008-01-01

    The Drosophila Toll receptor is activated by the endogenous protein ligand Spätzle in response to microbial stimuli in immunity and spatial cues during embryonic development. Downstream signaling is mediated by the adaptor proteins Tube, the kinase Pelle, and the Drosophila homologue of myeloid differentiation primary response protein (dMyD88). Here we have characterized heterodimeric (dMyD88-Tube) and heterotrimeric (dMyD88-Tube-Pelle) death domain complexes. We show that both the heterodimeric and heterotrimeric complexes form kidney-shaped structures and that Tube is bivalent and has separate high affinity binding sites for dMyD88 and Pelle. Additionally we found no interaction between the isolated death domains of Pelle and dMyD88. These results indicate that the mode of assembly of the heterotrimeric dMyD88-Tube-Pelle complex downstream of the activated Toll receptor is unique. The measured dissociation constants for the interaction between the death domains of dMyD88 and Tube and of Pelle and a preformed dMyD88-Tube complex are used to propose a model of the early postreceptor events in Drosophila Toll receptor signaling. PMID:18829464

  7. Assembly of oligomeric death domain complexes during Toll receptor signaling.

    Science.gov (United States)

    Moncrieffe, Martin C; Grossmann, J Günter; Gay, Nicholas J

    2008-11-28

    The Drosophila Toll receptor is activated by the endogenous protein ligand Spätzle in response to microbial stimuli in immunity and spatial cues during embryonic development. Downstream signaling is mediated by the adaptor proteins Tube, the kinase Pelle, and the Drosophila homologue of myeloid differentiation primary response protein (dMyD88). Here we have characterized heterodimeric (dMyD88-Tube) and heterotrimeric (dMyD88-Tube-Pelle) death domain complexes. We show that both the heterodimeric and heterotrimeric complexes form kidney-shaped structures and that Tube is bivalent and has separate high affinity binding sites for dMyD88 and Pelle. Additionally we found no interaction between the isolated death domains of Pelle and dMyD88. These results indicate that the mode of assembly of the heterotrimeric dMyD88-Tube-Pelle complex downstream of the activated Toll receptor is unique. The measured dissociation constants for the interaction between the death domains of dMyD88 and Tube and of Pelle and a preformed dMyD88-Tube complex are used to propose a model of the early postreceptor events in Drosophila Toll receptor signaling.

  8. Nuclear receptor TLX inhibits TGF-β signaling in glioblastoma.

    Science.gov (United States)

    Johansson, Erik; Zhai, Qiwei; Zeng, Zhao-Jun; Yoshida, Takeshi; Funa, Keiko

    2016-05-01

    TLX (also called NR2E1) is an orphan nuclear receptor that maintains stemness of neuronal stem cells. TLX is highly expressed in the most malignant form of glioma, glioblastoma multiforme (GBM), and is important for the proliferation and maintenance of the stem/progenitor cells of the tumor. Transforming Growth Factor-β (TGF-β) is a cytokine regulating many different cellular processes such as differentiation, migration, adhesion, cell death and proliferation. TGF-β has an important function in cancer where it can work as either a tumor suppressor or oncogene, depending on the cancer type and stage of tumor development. Since glioblastoma often have dysfunctional TGF-β signaling we wanted to find out if there is any interaction between TLX and TGF-β in glioblastoma cells. We demonstrate that knockdown of TLX enhances the canonical TGF-β signaling response in glioblastoma cell lines. TLX physically interacts with and stabilizes Smurf1, which can ubiquitinate and target TGF-β receptor II for degradation, whereas knockdown of TLX leads to stabilization of TGF-β receptor II, increased nuclear translocation of Smad2/3 and enhanced expression of TGF-β target genes. The interaction between TLX and TGF-β may play an important role in the regulation of proliferation and tumor-initiating properties of glioblastoma cells. Copyright © 2016. Published by Elsevier Inc.

  9. Optodynamic simulation of β-adrenergic receptor signalling.

    Science.gov (United States)

    Siuda, Edward R; McCall, Jordan G; Al-Hasani, Ream; Shin, Gunchul; Il Park, Sung; Schmidt, Martin J; Anderson, Sonya L; Planer, William J; Rogers, John A; Bruchas, Michael R

    2015-09-28

    Optogenetics has provided a revolutionary approach to dissecting biological phenomena. However, the generation and use of optically active GPCRs in these contexts is limited and it is unclear how well an opsin-chimera GPCR might mimic endogenous receptor activity. Here we show that a chimeric rhodopsin/β2 adrenergic receptor (opto-β2AR) is similar in dynamics to endogenous β2AR in terms of: cAMP generation, MAP kinase activation and receptor internalization. In addition, we develop and characterize a novel toolset of optically active, functionally selective GPCRs that can bias intracellular signalling cascades towards either G-protein or arrestin-mediated cAMP and MAP kinase pathways. Finally, we show how photoactivation of opto-β2AR in vivo modulates neuronal activity and induces anxiety-like behavioural states in both fiber-tethered and wireless, freely moving animals when expressed in brain regions known to contain β2ARs. These new GPCR approaches enhance the utility of optogenetics and allow for discrete spatiotemporal control of GPCR signalling in vitro and in vivo.

  10. Plant cell surface receptor-mediated signaling - a common theme amid diversity.

    Science.gov (United States)

    He, Yunxia; Zhou, Jinggeng; Shan, Libo; Meng, Xiangzong

    2018-01-29

    Sessile plants employ a diverse array of plasma membrane-bound receptors to perceive endogenous and exogenous signals for regulation of plant growth, development and immunity. These cell surface receptors include receptor-like kinases (RLKs) and receptor-like proteins (RLPs) that harbor different extracellular domains for perception of distinct ligands. Several RLK and RLP signaling pathways converge at the somatic embryogenesis receptor kinases (SERKs), which function as shared co-receptors. A repertoire of receptor-like cytoplasmic kinases (RLCKs) associate with the receptor complexes to relay intracellular signaling. Downstream of the receptor complexes, mitogen-activated protein kinase (MAPK) cascades are among the key signaling modules at which the signals converge, and these cascades regulate diverse cellular and physiological responses through phosphorylation of different downstream substrates. In this Review, we summarize the emerging common theme that underlies cell surface receptor-mediated signaling pathways in Arabidopsis thaliana : the dynamic association of RLKs and RLPs with specific co-receptors and RLCKs for signal transduction. We further discuss how signaling specificities are maintained through modules at which signals converge, with a focus on SERK-mediated receptor signaling. © 2018. Published by The Company of Biologists Ltd.

  11. Negative regulation of Toll-like receptor signalling 

    Directory of Open Access Journals (Sweden)

    Halina Antosz

    2013-04-01

    Full Text Available The mechanism of innate immunity is based on the pattern recognition receptors (PRR that recognize molecular patterns associated with pathogens (PAMPs. Among PRR receptors Toll-like receptors (TLR are distinguished. As a result of contact with pathogens, TLRs activate specific intracellular signaling pathways. It happens through proteins such as adaptor molecules, e.g. MyD88, TIRAP, TRIF, TRAM, and IPS-1, which participate in the cascade activation of kinases (IKK, MAP, RIP-1, TBK-1 as well as transcription factors (NF-κB, AP-1 and regulatory factor (IRF3. The result of this activation is the production of active proinflammatory cytokines, chemokines, interferons and enzymes. The PRR pathways are controlled by extra – and intracellular molecules to prevent overexpression of PRR. They include soluble receptors (sTLR, transmembrane proteins (ST2, SIGIRR, RP105, TRAIL-R and intracellular inhibitors (SOCS-1, SOCS-3, sMyD88, TOLLIP, IRAK-M, SARM, A20, β-arrestin, CYLD, SHP. These molecules maintain the balance between activation and inhibition and ensure balancing of the beneficial and adverse effects of antigen recognition.

  12. IGF-1 Receptor Expression on Circulating Osteoblast Progenitor Cells Predicts Tissue-Based Bone Formation Rate and Response to Teriparatide in Premenopausal Women With Idiopathic Osteoporosis.

    Science.gov (United States)

    Cohen, Adi; Kousteni, Stavroula; Bisikirska, Brygida; Shah, Jayesh G; Manavalan, J Sanil; Recker, Robert R; Lappe, Joan; Dempster, David W; Zhou, Hua; McMahon, Donald J; Bucovsky, Mariana; Kamanda-Kosseh, Mafo; Stubby, Julie; Shane, Elizabeth

    2017-06-01

    We have previously reported that premenopausal women with idiopathic osteoporosis (IOP) have profound microarchitectural deficiencies and heterogeneous bone remodeling. Those with the lowest bone formation rate have higher baseline serum insulin-like growth factor-1 (IGF-1) levels and less robust response to teriparatide. Because IGF-1 stimulates bone formation and is critical for teriparatide action on osteoblasts, these findings suggest a state of IGF-1 resistance in some IOP women. To further investigate the hypothesis that osteoblast and IGF-1-related mechanisms mediate differential responsiveness to teriparatide in IOP, we studied circulating osteoblast progenitor (COP) cells and their IGF-1 receptor (IGF-1R) expression. In premenopausal women with IOP, peripheral blood mononuclear cells (PBMCs) were obtained at baseline (n = 25) and over 24 months of teriparatide treatment (n = 11). Flow cytometry was used to identify and quantify COPs (non-hematopoetic lineage cells expressing osteocalcin and RUNX2) and to quantify IGF-1R expression levels. At baseline, both the percent of PBMCs that were COPs (%COP) and COP cell-surface IGF-1R expression correlated directly with several histomorphometric indices of bone formation in tetracycline-labeled transiliac biopsies. In treated subjects, both %COP and IGF-1R expression increased promptly after teriparatide, returning toward baseline by 18 months. Although neither baseline %COP nor increase in %COP after 3 months predicted the bone mineral density (BMD) response to teriparatide, the percent increase in IGF-1R expression on COPs at 3 months correlated directly with the BMD response to teriparatide. Additionally, lower IGF-1R expression after teriparatide was associated with higher body fat, suggesting links between teriparatide resistance, body composition, and the GH/IGF-1 axis. In conclusion, these assays may be useful to characterize bone remodeling noninvasively and may serve to predict early response to

  13. Metazoan-like signaling in a unicellular receptor tyrosine kinase

    Directory of Open Access Journals (Sweden)

    Schultheiss Kira P

    2013-02-01

    Full Text Available Abstract Background Receptor tyrosine kinases (RTKs are crucial components of signal transduction systems in multicellular animals. Surprisingly, numerous RTKs have been identified in the genomes of unicellular choanoflagellates and other protists. Here, we report the first biochemical study of a unicellular RTK, namely RTKB2 from Monosiga brevicollis. Results We cloned, expressed, and purified the RTKB2 kinase, and showed that it is enzymatically active. The activity of RTKB2 is controlled by autophosphorylation, as in metazoan RTKs. RTKB2 possesses six copies of a unique domain (designated RM2 in its C-terminal tail. An isolated RM2 domain (or a synthetic peptide derived from the RM2 sequence served as a substrate for RTKB2 kinase. When phosphorylated, the RM2 domain bound to the Src homology 2 domain of MbSrc1 from M. brevicollis. NMR structural studies of the RM2 domain indicated that it is disordered in solution. Conclusions Our results are consistent with a model in which RTKB2 activation stimulates receptor autophosphorylation within the RM2 domains. This leads to recruitment of Src-like kinases (and potentially other M. brevicollis proteins and further phosphorylation, which may serve to increase or dampen downstream signals. Thus, crucial features of signal transduction circuitry were established prior to the evolution of metazoans from their unicellular ancestors.

  14. Insulin-like growth factor-1 suppresses the Myostatin signaling pathway during myogenic differentiation

    International Nuclear Information System (INIS)

    Retamales, A.; Zuloaga, R.; Valenzuela, C.A.; Gallardo-Escarate, C.; Molina, A.; Valdés, J.A.

    2015-01-01

    Myogenic differentiation is a complex and well-coordinated process for generating mature skeletal muscle fibers. This event is autocrine/paracrine regulated by growth factors, principally Myostatin (MSTN) and Insulin-like Growth Factor-1 (IGF-1). Myostatin, a member of the transforming growth factor-β superfamily, is a negative regulator of skeletal muscle growth in vertebrates that exerts its inhibitory function by activating Smad transcription factors. In contrast, IGF-1 promotes the differentiation of skeletal myoblasts by activating the PI3K/Akt signaling pathway. This study reports on a novel functional crosstalk between the IGF-1 and MSTN signaling pathways, as mediated through interaction between PI3K/Akt and Smad3. Stimulation of skeletal myoblasts with MSTN resulted in a transient increase in the pSmad3:Smad3 ratio and Smad-dependent transcription. Moreover, MSTN inhibited myod gene expression and myoblast fusion in an Activin receptor-like kinase/Smad3-dependent manner. Preincubation of skeletal myoblasts with IGF-1 blocked MSTN-induced Smad3 activation, promoting myod expression and myoblast differentiation. This inhibitory effect of IGF-1 on the MSTN signaling pathway was dependent on IGF-1 receptor, PI3K, and Akt activities. Finally, immunoprecipitation assay analysis determined that IGF-1 pretreatment increased Akt and Smad3 interaction. These results demonstrate that the IGF-1/PI3K/Akt pathway may inhibit MSTN signaling during myoblast differentiation, providing new insight to existing knowledge on the complex crosstalk between both growth factors. - Highlights: • IGF-1 inhibits Myostatin canonical signaling pathway through IGF-1R/PI3K/Akt pathway. • IGF-1 promotes myoblast differentiation through a direct blocking of Myostatin signaling pathway. • IGF-1 induces the interaction of Akt with Smad3 in skeletal myoblast

  15. Insulin-like growth factor-1 suppresses the Myostatin signaling pathway during myogenic differentiation

    Energy Technology Data Exchange (ETDEWEB)

    Retamales, A.; Zuloaga, R.; Valenzuela, C.A. [Laboratorio de Biotecnología Molecular, Facultad de Ciencias Biológicas, Universidad Andrés Bello, Santiago (Chile); Gallardo-Escarate, C. [Laboratory of Biotechnology and Aquatic Genomics, Universidad de Concepción, Concepción (Chile); Interdisciplinary Center for Aquaculture Research (INCAR), P.O. Box 160-C, Concepción (Chile); Molina, A. [Laboratorio de Biotecnología Molecular, Facultad de Ciencias Biológicas, Universidad Andrés Bello, Santiago (Chile); Interdisciplinary Center for Aquaculture Research (INCAR), P.O. Box 160-C, Concepción (Chile); Valdés, J.A., E-mail: jvaldes@unab.cl [Laboratorio de Biotecnología Molecular, Facultad de Ciencias Biológicas, Universidad Andrés Bello, Santiago (Chile); Interdisciplinary Center for Aquaculture Research (INCAR), P.O. Box 160-C, Concepción (Chile)

    2015-08-21

    Myogenic differentiation is a complex and well-coordinated process for generating mature skeletal muscle fibers. This event is autocrine/paracrine regulated by growth factors, principally Myostatin (MSTN) and Insulin-like Growth Factor-1 (IGF-1). Myostatin, a member of the transforming growth factor-β superfamily, is a negative regulator of skeletal muscle growth in vertebrates that exerts its inhibitory function by activating Smad transcription factors. In contrast, IGF-1 promotes the differentiation of skeletal myoblasts by activating the PI3K/Akt signaling pathway. This study reports on a novel functional crosstalk between the IGF-1 and MSTN signaling pathways, as mediated through interaction between PI3K/Akt and Smad3. Stimulation of skeletal myoblasts with MSTN resulted in a transient increase in the pSmad3:Smad3 ratio and Smad-dependent transcription. Moreover, MSTN inhibited myod gene expression and myoblast fusion in an Activin receptor-like kinase/Smad3-dependent manner. Preincubation of skeletal myoblasts with IGF-1 blocked MSTN-induced Smad3 activation, promoting myod expression and myoblast differentiation. This inhibitory effect of IGF-1 on the MSTN signaling pathway was dependent on IGF-1 receptor, PI3K, and Akt activities. Finally, immunoprecipitation assay analysis determined that IGF-1 pretreatment increased Akt and Smad3 interaction. These results demonstrate that the IGF-1/PI3K/Akt pathway may inhibit MSTN signaling during myoblast differentiation, providing new insight to existing knowledge on the complex crosstalk between both growth factors. - Highlights: • IGF-1 inhibits Myostatin canonical signaling pathway through IGF-1R/PI3K/Akt pathway. • IGF-1 promotes myoblast differentiation through a direct blocking of Myostatin signaling pathway. • IGF-1 induces the interaction of Akt with Smad3 in skeletal myoblast.

  16. Signaling flux redistribution at toll-like receptor pathway junctions.

    Directory of Open Access Journals (Sweden)

    Kumar Selvarajoo

    Full Text Available Various receptors on cell surface recognize specific extracellular molecules and trigger signal transduction altering gene expression in the nucleus. Gain or loss-of-function mutations of one molecule have shown to affect alternative signaling pathways with a poorly understood mechanism. In Toll-like receptor (TLR 4 signaling, which branches into MyD88- and TRAM-dependent pathways upon lipopolysaccharide (LPS stimulation, we investigated the gain or loss-of-function mutations of MyD88. We predict, using a computational model built on the perturbation-response approach and the law of mass conservation, that removal and addition of MyD88 in TLR4 activation, enhances and impairs, respectively, the alternative TRAM-dependent pathway through signaling flux redistribution (SFR at pathway branches. To verify SFR, we treated MyD88-deficient macrophages with LPS and observed enhancement of TRAM-dependent pathway based on increased IRF3 phosphorylation and induction of Cxcl10 and Ifit2. Furthermore, increasing the amount of MyD88 in cultured cells showed decreased TRAM binding to TLR4. Investigating another TLR4 pathway junction, from TRIF to TRAF6, RIP1 and TBK1, the removal of MyD88-dependent TRAF6 increased expression of TRAM-dependent Cxcl10 and Ifit2. Thus, we demonstrate that SFR is a novel mechanism for enhanced activation of alternative pathways when molecules at pathway junctions are removed. Our data suggest that SFR may enlighten hitherto unexplainable intracellular signaling alterations in genetic diseases where gain or loss-of-function mutations are observed.

  17. Crammed signaling motifs in the T-cell receptor.

    Science.gov (United States)

    Borroto, Aldo; Abia, David; Alarcón, Balbino

    2014-09-01

    Although the T cell antigen receptor (TCR) is long known to contain multiple signaling subunits (CD3γ, CD3δ, CD3ɛ and CD3ζ), their role in signal transduction is still not well understood. The presence of at least one immunoreceptor tyrosine-based activation motif (ITAM) in each CD3 subunit has led to the idea that the multiplication of such elements essentially serves to amplify signals. However, the evolutionary conservation of non-ITAM sequences suggests that each CD3 subunit is likely to have specific non-redundant roles at some stage of development or in mature T cell function. The CD3ɛ subunit is paradigmatic because in a relatively short cytoplasmic sequence (∼55 amino acids) it contains several docking sites for proteins involved in intracellular trafficking and signaling, proteins whose relevance in T cell activation is slowly starting to be revealed. In this review we will summarize our current knowledge on the signaling effectors that bind directly to the TCR and we will propose a hierarchy in their response to TCR triggering. Copyright © 2014 Elsevier B.V. All rights reserved.

  18. Kinetics in Signal Transduction Pathways Involving Promiscuous Oligomerizing Receptors Can Be Determined by Receptor Specificity : Apoptosis Induction by TRAIL

    NARCIS (Netherlands)

    Szegezdi, Eva; van der Sloot, Almer M.; Mahalingam, Devalingam; O'Leary, Lynda; Cool, Robbert H.; Munoz, Ines G.; Montoya, Guillermo; Quax, Wim J.; de Jong, Steven; Samali, Afshin; Serrano, Luis

    Here we show by computer modeling that kinetics and outcome of signal transduction in case of hetero-oligomerizing receptors of a promiscuous ligand largely depend on the relative amounts of its receptors. Promiscuous ligands can trigger the formation of nonproductive receptor complexes, which slows

  19. Plant cell wall signalling and receptor-like kinases.

    Science.gov (United States)

    Wolf, Sebastian

    2017-02-15

    Communication between the extracellular matrix and the cell interior is essential for all organisms as intrinsic and extrinsic cues have to be integrated to co-ordinate development, growth, and behaviour. This applies in particular to plants, the growth and shape of which is governed by deposition and remodelling of the cell wall, a rigid, yet dynamic, extracellular network. It is thus generally assumed that cell wall surveillance pathways exist to monitor the state of the wall and, if needed, elicit compensatory responses such as altered expression of cell wall remodelling and biosynthesis genes. Here, I highlight recent advances in the field of cell wall signalling in plants, with emphasis on the role of plasma membrane receptor-like kinase complexes. In addition, possible roles for cell wall-mediated signalling beyond the maintenance of cell wall integrity are discussed. © 2017 The Author(s); published by Portland Press Limited on behalf of the Biochemical Society.

  20. Novel method for the study of receptor Ca2+ signalling exemplified by the NK1 receptor

    DEFF Research Database (Denmark)

    Heding, A; Elling, C E; Schwartz, T W

    2002-01-01

    We have used a novel technology (NovoStar from BMG Labtechnologies) for the study of the Ca2+ signalling of the human tackykinin NK1 (hNK-I receptor). The NovoStar is a microplate reader based on fluorescence and luminescence. The instrument implements a robotic pipettor arm and two microplate...... carriers, typically one for samples and one for cells. The robotic pipettor arm can transfer sample (agonist or antagonist) from the sample plate or other liquid containers to the cell plate, facilitating the study of Ca2+ signalling to such a degree that the instrument can be used for Medium Throughput...

  1. TSH Receptor Signaling Abrogation by a Novel Small Molecule.

    Science.gov (United States)

    Latif, Rauf; Realubit, Ronald B; Karan, Charles; Mezei, Mihaly; Davies, Terry F

    2016-01-01

    Pathological activation of the thyroid-stimulating hormone receptor (TSHR) is caused by thyroid-stimulating antibodies in patients with Graves' disease (GD) or by somatic and rare genomic mutations that enhance constitutive activation of the receptor influencing both G protein and non-G protein signaling. Potential selective small molecule antagonists represent novel therapeutic compounds for abrogation of such abnormal TSHR signaling. In this study, we describe the identification and in vitro characterization of a novel small molecule antagonist by high-throughput screening (HTS). The identification of the TSHR antagonist was performed using a transcription-based TSH-inhibition bioassay. TSHR-expressing CHO cells, which also expressed a luciferase-tagged CRE response element, were optimized using bovine TSH as the activator, in a 384 well plate format, which had a Z score of 0.3-0.6. Using this HTS assay, we screened a diverse library of ~80,000 compounds at a final concentration of 16.7 μM. The selection criteria for a positive hit were based on a mean signal threshold of ≥50% inhibition of control TSH stimulation. The screening resulted in 450 positive hits giving a hit ratio of 0.56%. A secondary confirmation screen against TSH and forskolin - a post receptor activator of adenylyl cyclase - confirmed one TSHR-specific candidate antagonist molecule (named VA-K-14). This lead molecule had an IC 50 of 12.3 μM and a unique chemical structure. A parallel analysis for cell viability indicated that the lead inhibitor was non-cytotoxic at its effective concentrations. In silico docking studies performed using a TSHR transmembrane model showed the hydrophobic contact locations and the possible mode of inhibition of TSHR signaling. Furthermore, this molecule was capable of inhibiting TSHR stimulation by GD patient sera and monoclonal-stimulating TSHR antibodies. In conclusion, we report the identification of a novel small molecule TSHR inhibitor, which has the

  2. DMPD: Modulation of Toll-interleukin 1 receptor mediated signaling. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 15662540 Modulation of Toll-interleukin 1 receptor mediated signaling. Li X, Qin J.... J Mol Med. 2005 Apr;83(4):258-66. Epub 2005 Jan 21. (.png) (.svg) (.html) (.csml) Show Modulation of Toll-i...nterleukin 1 receptor mediated signaling. PubmedID 15662540 Title Modulation of Toll-interleukin 1 receptor

  3. Retinoid receptor signaling and autophagy in acute promyelocytic leukemia

    Energy Technology Data Exchange (ETDEWEB)

    Orfali, Nina [Cork Cancer Research Center, University College Cork, Cork (Ireland); Department of Pharmacology, Weill Cornell Medical College, New York, NY 10065, USA. (United States); McKenna, Sharon L. [Cork Cancer Research Center, University College Cork, Cork (Ireland); Cahill, Mary R. [Department of Hematology, Cork University Hospital, Cork (Ireland); Gudas, Lorraine J., E-mail: ljgudas@med.cornell.edu [Department of Pharmacology, Weill Cornell Medical College, New York, NY 10065, USA. (United States); Mongan, Nigel P., E-mail: nigel.mongan@nottingham.ac.uk [Faculty of Medicine and Health Science, School of Veterinary Medicine and Science, University of Nottingham, LE12 5RD (United Kingdom); Department of Pharmacology, Weill Cornell Medical College, New York, NY 10065, USA. (United States)

    2014-05-15

    Retinoids are a family of signaling molecules derived from vitamin A with well established roles in cellular differentiation. Physiologically active retinoids mediate transcriptional effects on cells through interactions with retinoic acid (RARs) and retinoid-X (RXR) receptors. Chromosomal translocations involving the RARα gene, which lead to impaired retinoid signaling, are implicated in acute promyelocytic leukemia (APL). All-trans-retinoic acid (ATRA), alone and in combination with arsenic trioxide (ATO), restores differentiation in APL cells and promotes degradation of the abnormal oncogenic fusion protein through several proteolytic mechanisms. RARα fusion-protein elimination is emerging as critical to obtaining sustained remission and long-term cure in APL. Autophagy is a degradative cellular pathway involved in protein turnover. Both ATRA and ATO also induce autophagy in APL cells. Enhancing autophagy may therefore be of therapeutic benefit in resistant APL and could broaden the application of differentiation therapy to other cancers. Here we discuss retinoid signaling in hematopoiesis, leukemogenesis, and APL treatment. We highlight autophagy as a potential important regulator in anti-leukemic strategies. - Highlights: • Normal and aberrant retinoid signaling in hematopoiesis and leukemia is reviewed. • We suggest a novel role for RARα in the development of X-RARα gene fusions in APL. • ATRA therapy in APL activates transcription and promotes onco-protein degradation. • Autophagy may be involved in both onco-protein degradation and differentiation. • Pharmacologic autophagy induction may potentiate ATRA's therapeutic effects.

  4. Orphan nuclear receptor TLX regulates astrogenesis by modulating BMP signaling

    Directory of Open Access Journals (Sweden)

    Song eQin

    2014-04-01

    Full Text Available Neural stem cells (NSCs are self-renewing multipotent progenitors that generate both neurons and glia. The precise control of NSC behavior is fundamental to the architecture and function of the central nervous system. We previously demonstrated that the orphan nuclear receptor TLX is required for postnatal NSC activation and neurogenesis in the neurogenic niche. Here, we show that TLX modulates BMP-SMAD signaling to control the timing of postnatal astrogenesis. Genes involved in the BMP signaling pathway, such as Bmp4, Hes1, and Id3, are upregulated in postnatal brains lacking Tlx. Chromatin immunoprecipitation and electrophoretic mobility shift assays reveal that TLX can directly bind the enhancer region of Bmp4. In accordance with elevated BMP signaling, the downstream effectors SMAD1/5/8 are activated by phosphorylation in Tlx mutant mice. Consequently, Tlx mutant brains exhibit an early appearance and increased number of astrocytes with marker expression of glial fibrillary acidic protein (GFAP and S100B. Taken together, these results suggest that TLX tightly controls postnatal astrogenesis through the modulation of BMP-SMAD signaling pathway activity.

  5. Orphan nuclear receptor TLX regulates astrogenesis by modulating BMP signaling.

    Science.gov (United States)

    Qin, Song; Niu, Wenze; Iqbal, Nida; Smith, Derek K; Zhang, Chun-Li

    2014-01-01

    Neural stem cells (NSCs) are self-renewing multipotent progenitors that generate both neurons and glia. The precise control of NSC behavior is fundamental to the architecture and function of the central nervous system. We previously demonstrated that the orphan nuclear receptor TLX is required for postnatal NSC activation and neurogenesis in the neurogenic niche. Here, we show that TLX modulates bone morphogenetic protein (BMP)-SMAD signaling to control the timing of postnatal astrogenesis. Genes involved in the BMP signaling pathway, such as Bmp4, Hes1, and Id3, are upregulated in postnatal brains lacking Tlx. Chromatin immunoprecipitation and electrophoretic mobility shift assays reveal that TLX can directly bind the enhancer region of Bmp4. In accordance with elevated BMP signaling, the downstream effectors SMAD1/5/8 are activated by phosphorylation in Tlx mutant mice. Consequently, Tlx mutant brains exhibit an early appearance and increased number of astrocytes with marker expression of glial fibrillary acidic protein (GFAP) and S100B. Taken together, these results suggest that TLX tightly controls postnatal astrogenesis through the modulation of BMP-SMAD signaling pathway activity.

  6. Retinoid receptor signaling and autophagy in acute promyelocytic leukemia

    International Nuclear Information System (INIS)

    Orfali, Nina; McKenna, Sharon L.; Cahill, Mary R.; Gudas, Lorraine J.; Mongan, Nigel P.

    2014-01-01

    Retinoids are a family of signaling molecules derived from vitamin A with well established roles in cellular differentiation. Physiologically active retinoids mediate transcriptional effects on cells through interactions with retinoic acid (RARs) and retinoid-X (RXR) receptors. Chromosomal translocations involving the RARα gene, which lead to impaired retinoid signaling, are implicated in acute promyelocytic leukemia (APL). All-trans-retinoic acid (ATRA), alone and in combination with arsenic trioxide (ATO), restores differentiation in APL cells and promotes degradation of the abnormal oncogenic fusion protein through several proteolytic mechanisms. RARα fusion-protein elimination is emerging as critical to obtaining sustained remission and long-term cure in APL. Autophagy is a degradative cellular pathway involved in protein turnover. Both ATRA and ATO also induce autophagy in APL cells. Enhancing autophagy may therefore be of therapeutic benefit in resistant APL and could broaden the application of differentiation therapy to other cancers. Here we discuss retinoid signaling in hematopoiesis, leukemogenesis, and APL treatment. We highlight autophagy as a potential important regulator in anti-leukemic strategies. - Highlights: • Normal and aberrant retinoid signaling in hematopoiesis and leukemia is reviewed. • We suggest a novel role for RARα in the development of X-RARα gene fusions in APL. • ATRA therapy in APL activates transcription and promotes onco-protein degradation. • Autophagy may be involved in both onco-protein degradation and differentiation. • Pharmacologic autophagy induction may potentiate ATRA's therapeutic effects

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

    Science.gov (United States)

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

    2012-07-15

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

  8. Exponential signaling gain at the receptor level enhances signal-to-noise ratio in bacterial chemotaxis.

    Directory of Open Access Journals (Sweden)

    Silke Neumann

    Full Text Available Cellular signaling systems show astonishing precision in their response to external stimuli despite strong fluctuations in the molecular components that determine pathway activity. To control the effects of noise on signaling most efficiently, living cells employ compensatory mechanisms that reach from simple negative feedback loops to robustly designed signaling architectures. Here, we report on a novel control mechanism that allows living cells to keep precision in their signaling characteristics - stationary pathway output, response amplitude, and relaxation time - in the presence of strong intracellular perturbations. The concept relies on the surprising fact that for systems showing perfect adaptation an exponential signal amplification at the receptor level suffices to eliminate slowly varying multiplicative noise. To show this mechanism at work in living systems, we quantified the response dynamics of the E. coli chemotaxis network after genetically perturbing the information flux between upstream and downstream signaling components. We give strong evidence that this signaling system results in dynamic invariance of the activated response regulator against multiplicative intracellular noise. We further demonstrate that for environmental conditions, for which precision in chemosensing is crucial, the invariant response behavior results in highest chemotactic efficiency. Our results resolve several puzzling features of the chemotaxis pathway that are widely conserved across prokaryotes but so far could not be attributed any functional role.

  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. Poly(ADP-ribose) polymerase as a novel regulator of 17β-estradiol-induced cell growth through a control of the estrogen receptor/IGF-1 receptor/PDZK1 axis.

    Science.gov (United States)

    Kim, Hogyoung; Tarhuni, Abdelmetalab; Abd Elmageed, Zakaria Y; Boulares, A Hamid

    2015-07-17

    We and others have extensively investigated the role of PARP-1 in cell growth and demise in response to pathophysiological cues. Most of the clinical trials on PARP inhibitors are targeting primarily estrogen receptor (ER) negative cancers with BRCA-deficiency. It is surprising that the role of the enzyme has yet to be investigated in ER-mediated cell growth. It is noteworthy that ER is expressed in the majority of breast cancers. We recently showed that the scaffolding protein PDZK1 is critical for 17β-estradiol (E2)-induced growth of breast cancer cells. We demonstrated that E2-induced PDZK1 expression is indirectly regulated by ER and requires IGF-1 receptor (IGF-1R). The breast cancer cell lines MCF-7 and BT474 were used as ER(+) cell culture models. Thieno[2,3-c]isoquinolin-5-one (TIQ-A) and olaparib (AZD2281) were used as potent inhibitors of PARP. PARP-1 knockdown by shRNA was used to show specificity of the effects to PARP-1. In this study, we aimed to determine the effect of PARP inhibition on estrogen-induced growth of breast cancer cells and examine whether the potential effect is linked to PDZK1 and IGF-1R expression. Our results show that PARP inhibition pharmacologically by TIQ-A or olaparib or by PARP-1 knockdown blocked E2-dependent growth of MCF-7 cells. Such inhibitory effect was also observed in olaparib-treated BT474 cells. The effect of PARP inhibition on cell growth coincided with an efficient reduction in E2-induced PDZK1 expression. This effect was accompanied by a similar decrease in the cell cycle protein cyclin D1. PARP appeared to regulate E2-induced PDZK1 at the mRNA level. Such regulation may be linked to a modulation of IGF-1R as PARP inhibition pharmacologically or by PARP-1 knockdown efficiently reduced E2-induced expression of the receptor at the protein and mRNA levels. Overall, our results show for the first time that PARP regulates E2-mediated cell growth by controlling the ER/IGF-1R/PDZK1 axis. These findings suggest that the

  11. Retinoid receptor signaling and autophagy in acute promyelocytic leukemia.

    LENUS (Irish Health Repository)

    Orfali, Nina

    2014-05-15

    Retinoids are a family of signaling molecules derived from vitamin A with well established roles in cellular differentiation. Physiologically active retinoids mediate transcriptional effects on cells through interactions with retinoic acid (RARs) and retinoid-X (RXR) receptors. Chromosomal translocations involving the RARα gene, which lead to impaired retinoid signaling, are implicated in acute promyelocytic leukemia (APL). All-trans-retinoic acid (ATRA), alone and in combination with arsenic trioxide (ATO), restores differentiation in APL cells and promotes degradation of the abnormal oncogenic fusion protein through several proteolytic mechanisms. RARα fusion-protein elimination is emerging as critical to obtaining sustained remission and long-term cure in APL. Autophagy is a degradative cellular pathway involved in protein turnover. Both ATRA and ATO also induce autophagy in APL cells. Enhancing autophagy may therefore be of therapeutic benefit in resistant APL and could broaden the application of differentiation therapy to other cancers. Here we discuss retinoid signaling in hematopoiesis, leukemogenesis, and APL treatment. We highlight autophagy as a potential important regulator in anti-leukemic strategies.

  12. Significant blockade of multiple receptor tyrosine kinases by MGCD516 (Sitravatinib), a novel small molecule inhibitor, shows potent anti-tumor activity in preclinical models of sarcoma.

    Science.gov (United States)

    Patwardhan, Parag P; Ivy, Kathryn S; Musi, Elgilda; de Stanchina, Elisa; Schwartz, Gary K

    2016-01-26

    Sarcomas are rare but highly aggressive mesenchymal tumors with a median survival of 10-18 months for metastatic disease. Mutation and/or overexpression of many receptor tyrosine kinases (RTKs) including c-Met, PDGFR, c-Kit and IGF1-R drive defective signaling pathways in sarcomas. MGCD516 (Sitravatinib) is a novel small molecule inhibitor targeting multiple RTKs involved in driving sarcoma cell growth. In the present study, we evaluated the efficacy of MGCD516 both in vitro and in mouse xenograft models in vivo. MGCD516 treatment resulted in significant blockade of phosphorylation of potential driver RTKs and induced potent anti-proliferative effects in vitro. Furthermore, MGCD516 treatment of tumor xenografts in vivo resulted in significant suppression of tumor growth. Efficacy of MGCD516 was superior to imatinib and crizotinib, two other well-studied multi-kinase inhibitors with overlapping target specificities, both in vitro and in vivo. This is the first report describing MGCD516 as a potent multi-kinase inhibitor in different models of sarcoma, superior to imatinib and crizotinib. Results from this study showing blockade of multiple driver signaling pathways provides a rationale for further clinical development of MGCD516 for the treatment of patients with soft-tissue sarcoma.

  13. 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

  14. Sex-specific variation in signaling pathways and gene expression patterns in human leukocytes in response to endotoxin and exercise.

    Science.gov (United States)

    Abbasi, Asghar; de Paula Vieira, Rodolfo; Bischof, Felix; Walter, Michael; Movassaghi, Masoud; Berchtold, Nicole C; Niess, Andreas M; Cotman, Carl W; Northoff, Hinnak

    2016-11-10

    While exercise effects on the immune system have received increasing attention in recent years, it remains unclear to what extent gender and fluctuations in sex hormones during menstrual cycle influence immunological responses to exercise. We investigated mRNA changes induced through exhaustive exercise (half-marathon; pre-exercise and post-exercise [30 min, 3 h, 24 h] on whole blood cultures ± lipopolysaccharide [LPS] [1 h]) with a specific focus on sex differences (men vs women in luteal phase) as an extension of our previous study. Inflammation related signaling pathways, TLRs, cytosolic DNA sensing and RIG-I like receptors were differentially activated between sexes in LPS-stimulated cultures. Genes differentially regulated between sexes included TNIP-1, TNIP-3, IL-6, HIVEP1, CXCL3, CCR3, IL-8, and CD69, revealing a bias towards less anti-inflammatory gene regulation in women compared to men. In addition, several genes relevant to brain function (KMO, DDIT4, VEGFA, IGF1R, IGF2R, and FGD4) showed differential activation between sexes. Some of these genes (e.g., KMO in women, DDIT4 in both sexes) potentially constitute neuroprotective mechanisms. These data reveal that the exercise-induced change in gene expression might be gender and menstrual cycle phase dependent.

  15. The transcriptomics of glucocorticoid receptor signaling in developing zebrafish.

    Directory of Open Access Journals (Sweden)

    Dinushan Nesan

    Full Text Available Cortisol is the primary corticosteroid in teleosts that is released in response to stressor activation of the hypothalamus-pituitary-interrenal axis. The target tissue action of this hormone is primarily mediated by the intracellular glucocorticoid receptor (GR, a ligand-bound transcription factor. In developing zebrafish (Danio rerio embryos, GR transcripts and cortisol are maternally deposited into the oocyte prior to fertilization and influence early embryogenesis. To better understand of the molecular mechanisms involved, we investigated changes in the developmental transcriptome prior to hatch, in response to morpholino oligonucleotide knockdown of GR using the Agilent zebrafish microarray platform. A total of 1313 and 836 mRNA transcripts were significantly changed at 24 and 36 hours post fertilization (hpf, respectively. Functional analysis revealed numerous developmental processes under GR regulation, including neurogenesis, eye development, skeletal and cardiac muscle formation. Together, this study underscores a critical role for glucocorticoid signaling in programming molecular events essential for zebrafish development.

  16. Current Views of Toll-Like Receptor Signaling Pathways

    Directory of Open Access Journals (Sweden)

    Masahiro Yamamoto

    2010-01-01

    Full Text Available On microbial invasion, the host immediately evokes innate immune responses. Recent studies have demonstrated that Toll-like receptors (TLRs play crucial roles in innate responses that lead not only to the clearance of pathogens but also to the efficient establishment of acquired immunity by directly detecting molecules from microbes. In terms of intracellular TLR-mediated signaling pathways, cytoplasmic adaptor molecules containing Toll/IL-1R (TIR domains play important roles in inflammatory immune responses through the production of proinflammatory cytokines, nitric oxide, and type I interferon, and upregulation of costimulatory molecules. In this paper, we will describe our current understanding of the relationship between TLRs and their ligands derived from pathogens such as viruses, bacteria, fungi, and parasites. Moreover, we will review the historical and current literature to describe the mechanisms behind TLR-mediated activation of innate immune responses.

  17. Progesterone receptors (PR) mediate STAT actions: PR and prolactin receptor signaling crosstalk in breast cancer models.

    Science.gov (United States)

    Leehy, Katherine A; Truong, Thu H; Mauro, Laura J; Lange, Carol A

    2018-02-01

    Estrogen is the major mitogenic stimulus of mammary gland development during puberty wherein ER signaling acts to induce abundant PR expression. PR signaling, in contrast, is the primary driver of mammary epithelial cell proliferation in adulthood. The high circulating levels of progesterone during pregnancy signal through PR, inducing expression of the prolactin receptor (PRLR). Cooperation between PR and prolactin (PRL) signaling, via regulation of downstream components in the PRL signaling pathway including JAKs and STATs, facilitates the alveolar morphogenesis observed during pregnancy. Indeed, these pathways are fully integrated via activation of shared signaling pathways (i.e. JAKs, MAPKs) as well as by the convergence of PRs and STATs at target genes relevant to both mammary gland biology and breast cancer progression (i.e. proliferation, stem cell outgrowth, tissue cell type heterogeneity). Thus, rather than a single mediator such as ER, transcription factor cascades (ER>PR>STATs) are responsible for rapid proliferative and developmental programming in the normal mammary gland. It is not surprising that these same mediators typify uncontrolled proliferation in a majority of breast cancers, where ER and PR are most often co-expressed and may cooperate to drive malignant tumor progression. This review will primarily focus on the integration of PR and PRL signaling in breast cancer models and the importance of this cross-talk in cancer progression in the context of mammographic density. Components of these PR/PRL signaling pathways could offer alternative drug targets and logical complements to anti-ER or anti-estrogen-based endocrine therapies. Copyright © 2017 Elsevier Ltd. All rights reserved.

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

    Science.gov (United States)

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

    2012-08-03

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

  19. The level of insulin growth factor-1 receptor expression is directly correlated with the tumor uptake of {sup 111}In-IGF-1(E3R) in vivo and the clonogenic survival of breast cancer cells exposed in vitro to trastuzumab (Herceptin)

    Energy Technology Data Exchange (ETDEWEB)

    Cornelissen, Bart; McLarty, Kristin; Kersemans, Veerle [Department of Pharmaceutical Sciences, University of Toronto, Toronto, ON, M5S 3M2 (Canada); Reilly, Raymond M. [Department of Pharmaceutical Sciences, University of Toronto, Toronto, ON, M5S 3M2 (Canada); Department of Medical Imaging, University of Toronto, Toronto, ON, M5S 3M2 (Canada); Toronto General Research Institute, University Health Network Toronto, Toronto, ON, M5S 3M2 (Canada)], E-mail: raymond.reilly@utoronto.ca

    2008-08-15

    Introduction: Our objective was to define the relationships between tumor uptake of [{sup 111}In]-IGF-1 and [{sup 111}In]-IGF-1(E3R), an analogue which does not bind insulin growth factor-1 (IGF-1) binding proteins (i.e., IGFBP-3), and the level of IGF-1 receptor (IGF-1R) expression on human breast cancer (BC) xenografts in athymic mice, as well as the feasibility for tumor imaging. A second objective was to correlate IGF-1R (and HER2 density) with the cytotoxicity of trastuzumab in the absence/presence of IGFBP-3 or the IGF-1R tyrosine kinase inhibitor, AG1024. Methods: The tumor and normal tissue uptake of [{sup 111}In]-IGF-1 and [{sup 111}In]-IGF-1(E3R) were determined at 4 h postinjection in mice implanted subcutaneously with MDA-MB-231, H2N, HR2 or MCF-7/HER2-18 human BC xenografts (8.5x10{sup 4}, 1.4x10{sup 4}, 4.0x10{sup 4} and 1.0x10{sup 5} IGF-1R/cell, respectively). The effect of co-injection of IGF-1 (50 {mu}g) or IGFBP-3 (2 or 25 {mu}g) was studied. The relationship between tumor uptake of [{sup 111}In]-IGF-1(E3R) and IGF-1R density was examined. MicroSPECT/CT imaging was performed on mice with MCF-7/HER2-18 tumors injected with [{sup 111}In]-IGF-1(E3R). The surviving fraction of BC cells exposed to trastuzumab (67.5 {mu}g/ml) in the absence/presence of IGFBP-3 (1 {mu}g/ml) or the IGF-1R kinase inhibitor, AG1024 (1 or 5 {mu}g/ml), was determined. Results: [{sup 111}In]-IGF-1 was specifically taken up by MCF-7/HER2-18 xenografts; tumor uptake was decreased twofold when co-injected with IGF-1 (1.9{+-}0.1 vs. 1.0{+-}0.1 %ID/g). Co-injection of IGBP-3 decreased kidney uptake of [{sup 111}In]-IGF-1 up to twofold and increased circulating radioactivity threefold. There was a strong linear correlation (r{sup 2}=0.99) between the tumor uptake of {sup 111}In-IGF-1(E3R) and IGF-1R density. Tumor uptake ranged from 0.4{+-}0.05 %ID/g for H2N to 2.5{+-}0.5 %ID/g for MCF-7/HER2-18 xenografts. MCF-7/HER2-18 tumors were visualized by microSPECT/CT. Resistance of BC

  20. The level of insulin growth factor-1 receptor expression is directly correlated with the tumor uptake of 111In-IGF-1(E3R) in vivo and the clonogenic survival of breast cancer cells exposed in vitro to trastuzumab (Herceptin)

    International Nuclear Information System (INIS)

    Cornelissen, Bart; McLarty, Kristin; Kersemans, Veerle; Reilly, Raymond M.

    2008-01-01

    Introduction: Our objective was to define the relationships between tumor uptake of [ 111 In]-IGF-1 and [ 111 In]-IGF-1(E3R), an analogue which does not bind insulin growth factor-1 (IGF-1) binding proteins (i.e., IGFBP-3), and the level of IGF-1 receptor (IGF-1R) expression on human breast cancer (BC) xenografts in athymic mice, as well as the feasibility for tumor imaging. A second objective was to correlate IGF-1R (and HER2 density) with the cytotoxicity of trastuzumab in the absence/presence of IGFBP-3 or the IGF-1R tyrosine kinase inhibitor, AG1024. Methods: The tumor and normal tissue uptake of [ 111 In]-IGF-1 and [ 111 In]-IGF-1(E3R) were determined at 4 h postinjection in mice implanted subcutaneously with MDA-MB-231, H2N, HR2 or MCF-7/HER2-18 human BC xenografts (8.5x10 4 , 1.4x10 4 , 4.0x10 4 and 1.0x10 5 IGF-1R/cell, respectively). The effect of co-injection of IGF-1 (50 μg) or IGFBP-3 (2 or 25 μg) was studied. The relationship between tumor uptake of [ 111 In]-IGF-1(E3R) and IGF-1R density was examined. MicroSPECT/CT imaging was performed on mice with MCF-7/HER2-18 tumors injected with [ 111 In]-IGF-1(E3R). The surviving fraction of BC cells exposed to trastuzumab (67.5 μg/ml) in the absence/presence of IGFBP-3 (1 μg/ml) or the IGF-1R kinase inhibitor, AG1024 (1 or 5 μg/ml), was determined. Results: [ 111 In]-IGF-1 was specifically taken up by MCF-7/HER2-18 xenografts; tumor uptake was decreased twofold when co-injected with IGF-1 (1.9±0.1 vs. 1.0±0.1 %ID/g). Co-injection of IGBP-3 decreased kidney uptake of [ 111 In]-IGF-1 up to twofold and increased circulating radioactivity threefold. There was a strong linear correlation (r 2 =0.99) between the tumor uptake of 111 In-IGF-1(E3R) and IGF-1R density. Tumor uptake ranged from 0.4±0.05 %ID/g for H2N to 2.5±0.5 %ID/g for MCF-7/HER2-18 xenografts. MCF-7/HER2-18 tumors were visualized by microSPECT/CT. Resistance of BC cells to trastuzumab was directly associated with IGF-1R expression, despite co

  1. MicroRNA-375 Inhibits Growth and Enhances Radiosensitivity in Oral Squamous Cell Carcinoma by Targeting Insulin Like Growth Factor 1 Receptor

    Directory of Open Access Journals (Sweden)

    Bin Zhang

    2017-08-01

    Full Text Available Background: MicroRNAs (miRNAs have emerged as key players in various human biological processes, including tumorigenesis. Here, we investigated the roles of miR-375 in the pathogenesis of oral squamous cell carcinoma (OSCC. Methods: We performed quantitative real-time PCR (qRT-PCR to detect miR-375 expression in OSCC tissues and corresponding normal oral epithelial tissues and analyze the correlation of miR-375 expression with OSCC metastasis and patient’s survival. Then, the effects of miR-375 expression on proliferation, cell cycle, apoptosis and radiosensitivity in OSCC cells were determined by using MTT, flow cytometry and clonogenic survival assays. A dual-luciferase reporter assay was performed to test whether miR-375 binds to the 3’-untranslated region (3’-UTR of target mRNA. Results: The expression level of miR-375 in OSCC tissues was significantly lower than that in normal oral epithelial tissues, and low miR-375 expression was correlated with higher incidence of lymph node metastasis and poor survival of OSCC patients. Upregulation of miR-375 significantly inhibits growth, induces cell cycle arrest in G0/G1 phase, increases apoptosis and enhances radiosensitivity in OSCC cells. Analysis of luciferase activity demonstrated that miR-375 binds to the 3’-UTR of insulin like growth factor 1 receptor (IGF-1R. Small interfering RNA (shRNA-mediated IGF-1R knockdown mimics the effects of miR-375 upregulation, while overexpression of IGF-1R partially reverses those effects in OSCC cells. Conclusion: It was obviously demonstrated that miRNA-375 inhibits growth and enhances radiosensitivity in OSCC cells by targeting IGF-1R, suggesting that miR-375 may be a potential therapeutic target for OSCC patients.

  2. B cell antigen receptor signaling and internalization are mutually exclusive events.

    Directory of Open Access Journals (Sweden)

    Ping Hou

    2006-07-01

    Full Text Available Engagement of the B cell antigen receptor initiates two concurrent processes, signaling and receptor internalization. While both are required for normal humoral immune responses, the relationship between these two processes is unknown. Herein, we demonstrate that following receptor ligation, a small subpopulation of B cell antigen receptors are inductively phosphorylated and selectively retained at the cell surface where they can serve as scaffolds for the assembly of signaling molecules. In contrast, the larger population of non-phosphorylated receptors is rapidly endocytosed. Each receptor can undergo only one of two mutually exclusive fates because the tyrosine-based motifs that mediate signaling when phosphorylated mediate internalization when not phosphorylated. Mathematical modeling indicates that the observed competition between receptor phosphorylation and internalization enhances signaling responses to low avidity ligands.

  3. Biased signaling of G protein-coupled receptors - From a chemokine receptor CCR7 perspective

    DEFF Research Database (Denmark)

    Jørgensen, Astrid Sissel; Rosenkilde, Mette M; Hjortø, Gertrud M

    2018-01-01

    of CCL21 displays an extraordinarily strong glycosaminoglycan (GAG) binding, CCR7 plays a central role in coordinating the meeting between mature antigen presenting DCs and naïve T-cells which normally takes place in the lymph nodes (LNs). This process is a prerequisite for the initiation of an antigen...... the cell-based immune system is controlled. Bias comes in three forms; ligand-, receptor- and tissue-bias. Biased signaling is increasingly being recognized as playing an important role in contributing to the fine-tuned coordination of immune cell chemotaxis. In the current review we discuss the recent...

  4. The impact of the IGF-1 system of cancer cells on radiation response - An in vitro study.

    Science.gov (United States)

    Venkatachalam, Senthiladipan; Mettler, Esther; Fottner, Christian; Miederer, Matthias; Kaina, Bernd; Weber, Matthias M

    2017-12-01

    Overexpression of the insulin-like growth factor-1 receptor (IGF-1R) is associated with increased cell proliferation, differentiation, transformation, and tumorigenicity. Additionally, signaling involved in the resistance of cancer cells to radiotherapy originates from IGF-1R. The purpose of this study was to investigate the role of the IGF-1 system in the radiation response and further evaluate its effect on the expression of DNA repair pathway genes. To inhibit the IGF-1 system, we stably transfected the Caco-2 cell line to express a kinase-deficient IGF-1R mutant. We then studied the effects of this mutation on cell growth, the response to radiation, and clonogenic survival, as well as using a cell viability assay to examine DNA damage and repair. Finally, we performed immunofluorescence for γ-H2AX to examine double-strand DNA breaks and evaluated the expression of 84 key genes involved in DNA repair with a real-time PCR array. Mutant IGF-1R cells exhibited significantly blunted cell growth and viability, compared to wild-type cells, as well as reduced clonogenic survival after γ-irradiation. However, mutant IGF-1R cells did not show any significant delays in the repair of radiation-induced DNA double-strand breaks. Furthermore, expression of mutant IGF-1R significantly down-regulated the mRNA levels of BRCA2, a major protein involved in homologous recombination DNA repair. These results indicate that blocking the IGF-1R-mediated signaling cascade, through the expression of a kinase-deficient IGF-1R mutant, reduces cell growth and sensitizes cancer cells to ionizing radiation. Therefore, the IGF-1R system could be a potential target to enhance radio-sensitivity and the efficacy of cancer treatments.

  5. Receptor activity-independent recruitment of βarrestin2 reveals specific signalling modes

    Science.gov (United States)

    Terrillon, Sonia; Bouvier, Michel

    2004-01-01

    The roles of βarrestins in regulating G protein coupling and receptor endocytosis following agonist stimulation of G protein-coupled receptors are well characterised. However, their ability to act on their own as direct modulators or activators of signalling remains poorly characterised. Here, βarrestin2 intrinsic signalling properties were assessed by forcing the recruitment of this accessory protein to vasopressin V1a or V2 receptors independently of agonist-promoted activation of the receptors. Such induction of a stable interaction with βarrestin2 initiated receptor endocytosis leading to intracellular accumulation of the βarrestin/receptor complexes. Interestingly, βarrestin2 association to a single receptor protomer was sufficient to elicit receptor dimer internalisation. In addition to recapitulating βarrestin2 classical actions on receptor trafficking, the receptor activity-independent recruitment of βarrestin2 activated the extracellular signal-regulated kinases. In the latter case, recruitment to the receptor itself was not required since kinase activation could be mediated by βarrestin2 translocation to the plasma membrane in the absence of any interacting receptor. These data demonstrate that βarrestin2 can act as a ‘bonafide' signalling molecule even in the absence of activated receptor. PMID:15385966

  6. β1-adrenergic receptor stimulation by agonist Compound 49b restores insulin receptor signal transduction in vivo

    Science.gov (United States)

    Jiang, Youde; Zhang, Qiuhua; Ye, Eun-Ah

    2014-01-01

    Purpose Determine whether Compound 49b treatment ameliorates retinal changes due to the lack of β2-adrenergic receptor signaling. Methods Using retinas from 3-month-old β2-adrenergic receptor-deficient mice, we treated mice with our novel β1-/β2-adrenergic receptor agonist, Compound 49b, to assess the effects of adrenergic agonists acting only on β1-adrenergic receptors due to the absence of β2-adrenergic receptors. Western blotting or enzyme-linked immunosorbent assay (ELISA) analyses were performed for β1- and β2-adrenergic receptors, as well as key insulin resistance proteins, including TNF-α, SOCS3, IRS-1Ser307, and IRTyr960. Analyses were also performed on key anti- and proapoptotic proteins: Akt, Bcl-xL, Bax, and caspase 3. Electroretinogram analyses were conducted to assess functional changes, while histological assessment was conducted for changes in retinal thickness. Results A 2-month treatment of β2-adrenergic receptor-deficient mice with daily eye drops of 1 mM Compound 49b, a novel β1- and β2-adrenergic receptor agonist, reversed the changes in insulin resistance markers (TNF-α and SOCS3) observed in untreated β2-adrenergic receptor-deficient mice, and concomitantly increased morphological integrity (retinal thickness) and functional responses (electroretinogram amplitude). These results suggest that stimulating β1-adrenergic receptors on retinal endothelial cells or Müller cells can compensate for the loss of β2-adrenergic receptor signaling on Müller cells, restore insulin signal transduction, reduce retinal apoptosis, and enhance retinal function. Conclusions Since our previous studies with β1-adrenergic receptor knockout mice confirmed that the reverse also occurs (β2-adrenergic receptor stimulation can compensate for the loss of β1-adrenergic receptor activity), it appears that increased activity in either of these pathways alone is sufficient to block insulin resistance–based retinal cell apoptosis. PMID:24966659

  7. Distinct Phosphorylation Clusters Determine the Signaling Outcome of Free Fatty Acid Receptor 4/G Protein-Coupled Receptor 120

    DEFF Research Database (Denmark)

    Prihandoko, Rudi; Alvarez-Curto, Elisa; Hudson, Brian D

    2016-01-01

    of these phosphoacceptor sites to alanine completely prevented phosphorylation of mFFA4 but did not limit receptor coupling to extracellular signal regulated protein kinase 1 and 2 (ERK1/2) activation. Rather, an inhibitor of Gq/11proteins completely prevented receptor signaling to ERK1/2. By contrast, the recruitment...... activation. These unique observations define differential effects on signaling mediated by phosphorylation at distinct locations. This hallmark feature supports the possibility that the signaling outcome of mFFA4 activation can be determined by the pattern of phosphorylation (phosphorylation barcode...

  8. Receptor density balances signal stimulation and attenuation in membrane-assembled complexes of bacterial chemotaxis signaling proteins

    Science.gov (United States)

    Besschetnova, Tatiana Y.; Montefusco, David J.; Asinas, Abdalin E.; Shrout, Anthony L.; Antommattei, Frances M.; Weis, Robert M.

    2008-01-01

    All cells possess transmembrane signaling systems that function in the environment of the lipid bilayer. In the Escherichia coli chemotaxis pathway, the binding of attractants to a two-dimensional array of receptors and signaling proteins simultaneously inhibits an associated kinase and stimulates receptor methylation—a slower process that restores kinase activity. These two opposing effects lead to robust adaptation toward stimuli through a physical mechanism that is not understood. Here, we provide evidence of a counterbalancing influence exerted by receptor density on kinase stimulation and receptor methylation. Receptor signaling complexes were reconstituted over a range of defined surface concentrations by using a template-directed assembly method, and the kinase and receptor methylation activities were measured. Kinase activity and methylation rates were both found to vary significantly with surface concentration—yet in opposite ways: samples prepared at high surface densities stimulated kinase activity more effectively than low-density samples, whereas lower surface densities produced greater methylation rates than higher densities. FRET experiments demonstrated that the cooperative change in kinase activity coincided with a change in the arrangement of the membrane-associated receptor domains. The counterbalancing influence of density on receptor methylation and kinase stimulation leads naturally to a model for signal regulation that is compatible with the known logic of the E. coli pathway. Density-dependent mechanisms are likely to be general and may operate when two or more membrane-related processes are influenced differently by the two-dimensional concentration of pathway elements. PMID:18711126

  9. Regulation of G protein-coupled receptor signalling: focus on the cardiovascular system and regulator of G protein signalling proteins

    NARCIS (Netherlands)

    Hendriks-Balk, Mariëlle C.; Peters, Stephan L. M.; Michel, Martin C.; Alewijnse, Astrid E.

    2008-01-01

    G protein-coupled receptors (GPCRs) are involved in many biological processes. Therefore, GPCR function is tightly controlled both at receptor level and at the level of signalling components. Well-known mechanisms by which GPCR function can be regulated comprise desensitization/resensitization

  10. ZINC-INDUCED EGF RECEPTOR SIGNALING REQUIRES SRC-MEDIATED PHOSPHORYLATION OF THE EGF RECEPTOR ON TYROSINE 845 (Y845)

    Science.gov (United States)

    ZINC-INDUCED EGF RECEPTOR SIGNALING REQUIRES Src-MEDIATED PHOSPHORYLATION OF THE EGF RECEPTOR ON TYROSINE 845 (Y845)Weidong Wu1, Lee M. Graves2, Gordon N. Gill3 and James M. Samet4 1Center for Environmental Medicine and Lung Biology; 2Department of Pharmacology, University o...

  11. Real-time trafficking and signaling of the glucagon-like peptide-1 receptor

    DEFF Research Database (Denmark)

    Roed, Sarah Noerklit; Wismann, Pernille; Underwood, Christina Rye

    2014-01-01

    The glucagon-like peptide-1 incretin receptor (GLP-1R) of family B G protein-coupled receptors (GPCRs) is a major drug target in type-2-diabetes due to its regulatory effect on post-prandial blood-glucose levels. The mechanism(s) controlling GLP-1R mediated signaling are far from fully understood....... A fundamental mechanism controlling the signaling capacity of GPCRs is the post-endocytic trafficking of receptors between recycling and degradative fates. Here, we combined microscopy with novel real-time assays to monitor both receptor trafficking and signaling in living cells. We find that the human GLP-1R...

  12. The Role of Cgrp-Receptor Component Protein (Rcp in Cgrp-Mediated Signal Transduction

    Directory of Open Access Journals (Sweden)

    M. A. Prado

    2001-01-01

    Full Text Available The calcitonin gene-related peptide (CGRP-receptor component protein (RCP is a 17-kDa intracellular peripheral membrane protein required for signal transduction at CGRP receptors. To determine the role of RCP in CGRP-mediated signal transduction, RCP was depleted from NIH3T3 cells using antisense strategy. Loss of RCP protein correlated with loss of cAMP production by CGRP in the antisense cells. In contrast, loss of RCP had no effect on CGRP-mediated binding; therefore RCP is not acting as a chaperone for the CGRP receptor. Instead, RCP is a novel signal transduction molecule that couples the CGRP receptor to the cellular signal transduction machinery. RCP thus represents a prototype for a new class of signal transduction proteins that are required for regulation of G protein-coupled receptors.

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

    OpenAIRE

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

    2015-01-01

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

  14. Cocaine Disrupts Histamine H3 Receptor Modulation of Dopamine D1 Receptor Signaling: σ1-D1-H3 Receptor Complexes as Key Targets for Reducing Cocaine's Effects

    Science.gov (United States)

    Moreno, Estefanía; Moreno-Delgado, David; Navarro, Gemma; Hoffmann, Hanne M.; Fuentes, Silvia; Rosell-Vilar, Santi; Gasperini, Paola; Rodríguez-Ruiz, Mar; Medrano, Mireia; Mallol, Josefa; Cortés, Antoni; Casadó, Vicent; Lluís, Carme; Ferré, Sergi; Ortiz, Jordi; Canela, Enric

    2014-01-01

    The general effects of cocaine are not well understood at the molecular level. What is known is that the dopamine D1 receptor plays an important role. Here we show that a key mechanism may be cocaine's blockade of the histamine H3 receptor-mediated inhibition of D1 receptor function. This blockade requires the σ1 receptor and occurs upon cocaine binding to σ1-D1-H3 receptor complexes. The cocaine-mediated disruption leaves an uninhibited D1 receptor that activates Gs, freely recruits β-arrestin, increases p-ERK 1/2 levels, and induces cell death when over activated. Using in vitro assays with transfected cells and in ex vivo experiments using both rats acutely treated or self-administered with cocaine along with mice depleted of σ1 receptor, we show that blockade of σ1 receptor by an antagonist restores the protective H3 receptor-mediated brake on D1 receptor signaling and prevents the cell death from elevated D1 receptor signaling. These findings suggest that a combination therapy of σ1R antagonists with H3 receptor agonists could serve to reduce some effects of cocaine. PMID:24599455

  15. Innate immune receptor Toll-like receptor 4 signalling in neuropsychiatric diseases.

    Science.gov (United States)

    García Bueno, B; Caso, J R; Madrigal, J L M; Leza, J C

    2016-05-01

    The innate immunity is a stereotyped first line of defense against pathogens and unspecified damage signals. One of main actors of innate immunity are the Toll-like receptors (TLRs), and one of the better characterized members of this family is TLR-4, that it is mainly activated by Gram-negative bacteria lipopolysaccharide. In brain, TLR-4 organizes innate immune responses against infections or cellular damage, but also possesses other physiological functions. In the last years, some evidences suggest a role of TLR-4 in stress and stress-related neuropsychiatric diseases. Peripheral and brain TLR-4 activation triggers sickness behavior, and its expression is a risk factor of depression. Some elements of the TLR-4 signaling pathway are up-regulated in peripheral samples and brain post-mortem tissue from depressed and suicidal patients. The "leaky gut" hypothesis of neuropsychiatric diseases is based on the existence of an increase of the intestinal permeability which results in bacterial translocation able to activate TLR-4. Enhanced peripheral TLR-4 expression/activity has been described in subjects diagnosed with schizophrenia, bipolar disorder and in autistic children. A role for TLR-4 in drugs abuse has been also proposed. The therapeutic potential of pharmacological/genetic modulation of TLRs signaling pathways in neuropsychiatry is promising, but a great preclinical/clinical scientific effort is still needed. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. SGIP1 alters internalization and modulates signaling of activated cannabinoid receptor 1 in a biased manner

    Czech Academy of Sciences Publication Activity Database

    Hájková, Alena; Techlovská, Šárka; Dvořáková, Michaela; Chambers, Jayne Nicole; Kumpošt, Jiří; Hubálková, Pavla; Prezeau, L.; Blahoš, Jaroslav

    2016-01-01

    Roč. 107, léto (2016), s. 201-214 ISSN 0028-3908 R&D Projects: GA ČR GAP303/12/2408 Institutional support: RVO:68378050 Keywords : Seven transmembrane receptors * G-protein coupled receptors * Cannabinoid receptor 1 * Protein-protein interactions * Bias signaling * Receptor endocytosis Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 5.012, year: 2016

  17. Quercetin suppresses insulin receptor signaling through inhibition of the insulin ligand–receptor binding and therefore impairs cancer cell proliferation

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Feng [Department of Gastroenterology, The Tenth People’s Hospital of Shanghai, Tongji University, Shanghai 200072 (China); Department of Nanomedicine, Houston Methodist Research Institute, Houston, TX 77030 (United States); Yang, Yong, E-mail: yyang@houstonmethodist.org [Department of Nanomedicine, Houston Methodist Research Institute, Houston, TX 77030 (United States); Department of Medicine, Weill Cornell Medical College, New York, NY 10065 (United States)

    2014-10-03

    Graphical abstract: - Highlights: • Quercetin inhibits insulin ligand–receptor interactions. • Quercetin reduces downstream insulin receptor signaling. • Quercetin blocks insulin induced glucose uptake. • Quercetin suppresses insulin stimulated cancer cell proliferation and tumor growth. - Abstract: Although the flavonoid quercetin is known to inhibit activation of insulin receptor signaling, the inhibitory mechanism is largely unknown. In this study, we demonstrate that quercetin suppresses insulin induced dimerization of the insulin receptor (IR) through interfering with ligand–receptor interactions, which reduces the phosphorylation of IR and Akt. This inhibitory effect further inhibits insulin stimulated glucose uptake due to decreased cell membrane translocation of glucose transporter 4 (GLUT4), resulting in impaired cancer cell proliferation. The effect of quercetin in inhibiting tumor growth was also evident in an in vivo model, indicating a potential future application for quercetin in the treatment of cancers.

  18. Quercetin suppresses insulin receptor signaling through inhibition of the insulin ligand–receptor binding and therefore impairs cancer cell proliferation

    International Nuclear Information System (INIS)

    Wang, Feng; Yang, Yong

    2014-01-01

    Graphical abstract: - Highlights: • Quercetin inhibits insulin ligand–receptor interactions. • Quercetin reduces downstream insulin receptor signaling. • Quercetin blocks insulin induced glucose uptake. • Quercetin suppresses insulin stimulated cancer cell proliferation and tumor growth. - Abstract: Although the flavonoid quercetin is known to inhibit activation of insulin receptor signaling, the inhibitory mechanism is largely unknown. In this study, we demonstrate that quercetin suppresses insulin induced dimerization of the insulin receptor (IR) through interfering with ligand–receptor interactions, which reduces the phosphorylation of IR and Akt. This inhibitory effect further inhibits insulin stimulated glucose uptake due to decreased cell membrane translocation of glucose transporter 4 (GLUT4), resulting in impaired cancer cell proliferation. The effect of quercetin in inhibiting tumor growth was also evident in an in vivo model, indicating a potential future application for quercetin in the treatment of cancers

  19. Role of androgen receptor on cyclic mechanical stretch-regulated proliferation of C2C12 myoblasts and its upstream signals: IGF-1-mediated PI3K/Akt and MAPKs pathways.

    Science.gov (United States)

    Ma, Yiming; Fu, Shaoting; Lu, Lin; Wang, Xiaohui

    2017-07-15

    To detect the effects of androgen receptor (AR) on cyclic mechanical stretch-modulated proliferation of C2C12 myoblasts and its pathways: roles of IGF-1, PI3K and MAPK. C2C12 were randomly divided into five groups: un-stretched control, six or 8 h of fifteen percent stretch, and six or 8 h of twenty percent stretch. Cyclic mechanical stretch of C2C12 were completed using a computer-controlled FlexCell Strain Unit. Cell proliferation and IGF-1 concentration in medium were detected by CCK8 and ELISA, respectively. Expressions of AR and IGF-1R, and expressions and activities of PI3K, p38 and ERK1/2 in stretched C2C12 cells were determined by Western blot. ①The proliferation of C2C12 cells, IGF-1 concentration in medium, expressions of AR and IGF-1R, and activities of PI3K, p38 and ERK1/2 were increased by 6 h of fifteen percent stretch, while decreased by twenty percent stretch for six or 8 h ②The fifteen percent stretch-increased proliferation of C2C12 cells was reversed by AR inhibitor, Flutamide. ③The increases of AR expression, activities of PI3K, p38 and ERK1/2 resulted from fifteen percent stretch were attenuated by IGF-1 neutralizing antibody, while twenty percent stretch-induced decreases of the above indicators were enhanced by recombinant IGF-1. ④Specific inhibitors of p38, ERK1/2 and PI3K all decreased the expression of AR in fifteen percent and twenty percent of stretched C2C12 cells. Cyclic mechanical stretch modulated the proliferation of C2C12 cells, which may be attributed to the alterations of AR via IGF-1-PI3K/Akt and IGF-1-MAPK (p38, ERK1/2) pathways in C2C12 cells. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Cell surface receptors for signal transduction and ligand transport: a design principles study.

    Directory of Open Access Journals (Sweden)

    Harish Shankaran

    2007-06-01

    Full Text Available Receptors constitute the interface of cells to their external environment. These molecules bind specific ligands involved in multiple processes, such as signal transduction and nutrient transport. Although a variety of cell surface receptors undergo endocytosis, the systems-level design principles that govern the evolution of receptor trafficking dynamics are far from fully understood. We have constructed a generalized mathematical model of receptor-ligand binding and internalization to understand how receptor internalization dynamics encodes receptor function and regulation. A given signaling or transport receptor system represents a particular implementation of this module with a specific set of kinetic parameters. Parametric analysis of the response of receptor systems to ligand inputs reveals that receptor systems can be characterized as being: i avidity-controlled where the response control depends primarily on the extracellular ligand capture efficiency, ii consumption-controlled where the ability to internalize surface-bound ligand is the primary control parameter, and iii dual-sensitivity where both the avidity and consumption parameters are important. We show that the transferrin and low-density lipoprotein receptors are avidity-controlled, the vitellogenin receptor is consumption-controlled, and the epidermal growth factor receptor is a dual-sensitivity receptor. Significantly, we show that ligand-induced endocytosis is a mechanism to enhance the accuracy of signaling receptors rather than merely serving to attenuate signaling. Our analysis reveals that the location of a receptor system in the avidity-consumption parameter space can be used to understand both its function and its regulation.

  1. Signaling properties and pharmacological analysis of two sulfakinin receptors from the red flour beetle, Tribolium castaneum.

    Directory of Open Access Journals (Sweden)

    Sven Zels

    Full Text Available Sulfakinin is an insect neuropeptide that constitutes an important component of the complex network of hormonal and neural factors that regulate feeding and digestion. The key modulating functions of sulfakinin are mediated by binding and signaling via G-protein coupled receptors. Although a substantial amount of functional data have already been reported on sulfakinins in different insect species, only little information is known regarding the properties of their respective receptors. In this study, we report on the molecular cloning, functional expression and characterization of two sulfakinin receptors in the red flour beetle, Tribolium castaneum. Both receptor open reading frames show extensive sequence similarity with annotated sulfakinin receptors from other insects. Comparison of the sulfakinin receptor sequences with homologous vertebrate cholecystokinin receptors reveals crucial conserved regions for ligand binding and receptor activation. Quantitative reverse transcriptase PCR shows that transcripts of both receptors are primarily expressed in the central nervous system of the beetle. Pharmacological characterization using 29 different peptide ligands clarified the essential requirements for efficient activation of these sulfakinin receptors. Analysis of the signaling pathway in multiple cell lines disclosed that the sulfakinin receptors of T. castaneum can stimulate both the Ca²⁺ and cyclic AMP second messenger pathways. This in depth characterization of two insect sulfakinin receptors may provide useful leads for the further development of receptor ligands with a potential applicability in pest control and crop protection.

  2. Signaling properties and pharmacological analysis of two sulfakinin receptors from the red flour beetle, Tribolium castaneum.

    Science.gov (United States)

    Zels, Sven; Verlinden, Heleen; Dillen, Senne; Vleugels, Rut; Nachman, Ronald J; Vanden Broeck, Jozef

    2014-01-01

    Sulfakinin is an insect neuropeptide that constitutes an important component of the complex network of hormonal and neural factors that regulate feeding and digestion. The key modulating functions of sulfakinin are mediated by binding and signaling via G-protein coupled receptors. Although a substantial amount of functional data have already been reported on sulfakinins in different insect species, only little information is known regarding the properties of their respective receptors. In this study, we report on the molecular cloning, functional expression and characterization of two sulfakinin receptors in the red flour beetle, Tribolium castaneum. Both receptor open reading frames show extensive sequence similarity with annotated sulfakinin receptors from other insects. Comparison of the sulfakinin receptor sequences with homologous vertebrate cholecystokinin receptors reveals crucial conserved regions for ligand binding and receptor activation. Quantitative reverse transcriptase PCR shows that transcripts of both receptors are primarily expressed in the central nervous system of the beetle. Pharmacological characterization using 29 different peptide ligands clarified the essential requirements for efficient activation of these sulfakinin receptors. Analysis of the signaling pathway in multiple cell lines disclosed that the sulfakinin receptors of T. castaneum can stimulate both the Ca²⁺ and cyclic AMP second messenger pathways. This in depth characterization of two insect sulfakinin receptors may provide useful leads for the further development of receptor ligands with a potential applicability in pest control and crop protection.

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

    Directory of Open Access Journals (Sweden)

    Claire J Fenech

    2009-10-01

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

  4. The Role of (BETA)-Catenin in Androgen Receptor Signaling

    National Research Council Canada - National Science Library

    Bhowmick, Neil A

    2006-01-01

    .... Our preliminary data seem indicate stromally derived paracrine Wnt family members activate theepithelial frizzled receptor to enable prostate epithelial survival in an androgen deficient environment...

  5. Binding Mode of Insulin Receptor and Agonist Peptide

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Insulin is a protein hormone secreted by pancreatic β cells. One of its main functions is to keep the balance of glucose inside the body by regulating the absorption and metabolism of glucose in the periphery tissue, as well as the production and storage of hepatic glycogen. The insulin receptor is a transmembrane glycoprotein in which two α subunits with a molecular weight of 135 kD and twoβ subunits with a molecular weight of 95 kD are joined by a disulfide bond to form a β-α-α-β structure. The extracellular α subunit, especially, its three domains near the N-terminal are partially responsible for signal transduction or ligand-binding, as indicated by the experiments. The extracellular α subunits are involved in binding the ligands. The experimental results indicate that the three domains of the N-terminal of the α subunits are the main determinative parts of the insulin receptor to bind the insulin or mimetic peptide.We employed the extracellular domain (PDBID: 1IGR) of the insulin-like growth factor-1 receptor (IGF-1 R ) as the template to simulate and optimize the spatial structures of the three domains in the extracellular domain of the insulin receptor, which includes 468 residues. The work was accomplished by making use of the homology program in the Insight Ⅱ package on an Origin3800 server. The docking calculations of the insulin receptor obtained by homology with hexapeptides were carried out by means of the program Affinity. The analysis indicated that there were hydrogen bonding, and electrostatic and hydrophobic effects in the docking complex of the insulin receptor with hexapeptides.Moreover, we described the spatial orientation of a mimetic peptide with agonist activity in the docking complex. We obtained a rough model of binding of DLAPSQ or STIVYS with the insulin receptor, which provides the powerful theoretical support for designing the minimal insulin mimetic peptide with agonist activity, making it possible to develop oral small

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

    Science.gov (United States)

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

    2013-05-07

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

  7. 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

  8. Testin, a novel binding partner of the calcium-sensing receptor, enhances receptor-mediated Rho-kinase signalling

    International Nuclear Information System (INIS)

    Magno, Aaron L.; Ingley, Evan; Brown, Suzanne J.; Conigrave, Arthur D.; Ratajczak, Thomas; Ward, Bryan K.

    2011-01-01

    Highlights: → A yeast two-hybrid screen revealed testin bound to the calcium-sensing receptor. → The second zinc finger of LIM domain 1 of testin is critical for interaction. → Testin bound to a region of the receptor tail important for cell signalling. → Testin and receptor interaction was confirmed in mammalian (HEK293) cells. → Overexpression of testin enhanced receptor-mediated Rho signalling in HEK293 cells. -- Abstract: The calcium-sensing receptor (CaR) plays an integral role in calcium homeostasis and the regulation of other cellular functions including cell proliferation and cytoskeletal organisation. The multifunctional nature of the CaR is manifested through ligand-dependent stimulation of different signalling pathways that are also regulated by partner binding proteins. Following a yeast two-hybrid library screen using the intracellular tail of the CaR as bait, we identified several novel binding partners including the focal adhesion protein, testin. Testin has not previously been shown to interact with cell surface receptors. The sites of interaction between the CaR and testin were mapped to the membrane proximal region of the receptor tail and the second zinc-finger of LIM domain 1 of testin, the integrity of which was found to be critical for the CaR-testin interaction. The CaR-testin association was confirmed in HEK293 cells by coimmunoprecipitation and confocal microscopy studies. Ectopic expression of testin in HEK293 cells stably expressing the CaR enhanced CaR-stimulated Rho activity but had no effect on CaR-stimulated ERK signalling. These results suggest an interplay between the CaR and testin in the regulation of CaR-mediated Rho signalling with possible effects on the cytoskeleton.

  9. The orphan receptor ALK7 and the Activin receptor ALK4 mediate signaling by Nodal proteins during vertebrate development

    Science.gov (United States)

    Reissmann, Eva; Jörnvall, Henrik; Blokzijl, Andries; Andersson, Olov; Chang, Chenbei; Minchiotti, Gabriella; Persico, M. Graziella; Ibáñez, Carlos F.; Brivanlou, Ali H.

    2001-01-01

    Nodal proteins have crucial roles in mesendoderm formation and left–right patterning during vertebrate development. The molecular mechanisms of signal transduction by Nodal and related ligands, however, are not fully understood. In this paper, we present biochemical and functional evidence that the orphan type I serine/threonine kinase receptor ALK7 acts as a receptor for mouse Nodal and Xenopus Nodal-related 1 (Xnr1). Receptor reconstitution experiments indicate that ALK7 collaborates with ActRIIB to confer responsiveness to Xnr1 and Nodal. Both receptors can independently bind Xnr1. In addition, Cripto, an extracellular protein genetically implicated in Nodal signaling, can independently interact with both Xnr1 and ALK7, and its expression greatly enhances the ability of ALK7 and ActRIIB to respond to Nodal ligands. The Activin receptor ALK4 is also able to mediate Nodal signaling but only in the presence of Cripto, with which it can also interact directly. A constitutively activated form of ALK7 mimics the mesendoderm-inducing activity of Xnr1 in Xenopus embryos, whereas a dominant-negative ALK7 specifically blocks the activities of Nodal and Xnr1 but has little effect on other related ligands. In contrast, a dominant-negative ALK4 blocks all mesoderm-inducing ligands tested, including Nodal, Xnr1, Xnr2, Xnr4, and Activin. In agreement with a role in Nodal signaling, ALK7 mRNA is localized to the ectodermal and organizer regions of Xenopus gastrula embryos and is expressed during early stages of mouse embryonic development. Therefore, our results indicate that both ALK4 and ALK7 can mediate signal transduction by Nodal proteins, although ALK7 appears to be a receptor more specifically dedicated to Nodal signaling. PMID:11485994

  10. Molecular and functional profiling of histamine receptor-mediated calcium ion signals in different cell lines.

    Science.gov (United States)

    Meisenberg, Annika; Kaschuba, Dagmar; Balfanz, Sabine; Jordan, Nadine; Baumann, Arnd

    2015-10-01

    Calcium ions (Ca(2+)) play a pivotal role in cellular physiology. Often Ca(2+)-dependent processes are studied in commonly available cell lines. To induce Ca(2+) signals on demand, cells may need to be equipped with additional proteins. A prominent group of membrane proteins evoking Ca(2+) signals are G-protein coupled receptors (GPCRs). These proteins register external signals such as photons, odorants, and neurotransmitters and convey ligand recognition into cellular responses, one of which is Ca(2+) signaling. To avoid receptor cross-talk or cross-activation with introduced proteins, the repertoire of cell-endogenous receptors must be known. Here we examined the presence of histamine receptors in six cell lines frequently used as hosts to study cellular signaling processes. In a concentration-dependent manner, histamine caused a rise in intracellular Ca(2+) in HeLa, HEK 293, and COS-1 cells. The concentration for half-maximal activation (EC50) was in the low micromolar range. In individual cells, transient Ca(2+) signals and Ca(2+) oscillations were uncovered. The results show that (i) HeLa, HEK 293, and COS-1 cells express sufficient amounts of endogenous receptors to study cellular Ca(2+) signaling processes directly and (ii) these cell lines are suitable for calibrating Ca(2+) biosensors in situ based on histamine receptor evoked responses. Copyright © 2015 Elsevier Inc. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    Inês Gomes Ferreira

    2018-02-01

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

  12. Cross-talk between an activator of nuclear receptors-mediated transcription and the D1 dopamine receptor signaling pathway.

    Science.gov (United States)

    Schmidt, Azriel; Vogel, Robert; Rutledge, Su Jane; Opas, Evan E; Rodan, Gideon A; Friedman, Eitan

    2005-03-01

    Nuclear receptors are transcription factors that usually interact, in a ligand-dependent manner, with specific DNA sequences located within promoters of target genes. The nuclear receptors can also be controlled in a ligand-independent manner via the action of membrane receptors and cellular signaling pathways. 5-Tetradecyloxy-2-furancarboxylic acid (TOFA) was shown to stimulate transcription from the MMTV promoter via chimeric receptors that consist of the DNA binding domain of GR and the ligand binding regions of the PPARbeta or LXRbeta nuclear receptors (GR/PPARbeta and GR/LXRbeta). TOFA and hydroxycholesterols also modulate transcription from NF-kappaB- and AP-1-controlled reporter genes and induce neurite differentiation in PC12 cells. In CV-1 cells that express D(1) dopamine receptors, D(1) dopamine receptor stimulation was found to inhibit TOFA-stimulated transcription from the MMTV promoter that is under the control of chimeric GR/PPARbeta and GR/LXRbeta receptors. Treatment with the D(1) dopamine receptor antagonist, SCH23390, prevented dopamine-mediated suppression of transcription, and by itself increased transcription controlled by GR/LXRbeta. Furthermore, combined treatment of CV-1 cells with TOFA and SCH23390 increased transcription controlled by the GR/LXRbeta chimeric receptor synergistically. The significance of this in vitro synergy was demonstrated in vivo, by the observation that SCH23390 (but not haloperidol)-mediated catalepsy in rats was potentiated by TOFA, thus showing that an agent that mimics the in vitro activities of compounds that activate members of the LXR and PPAR receptor families can influence D1 dopamine receptor elicited responses.

  13. c-kitpos GATA-4 high rat cardiac stem cells foster adult cardiomyocyte survival through IGF-1 paracrine signalling.

    Directory of Open Access Journals (Sweden)

    Nanako Kawaguchi

    2010-12-01

    Full Text Available Resident c-kit positive (c-kitpos cardiac stem cells (CSCs could be considered the most appropriate cell type for myocardial regeneration therapies. However, much is still unknown regarding their biological properties and potential.We produced clones of high and low expressing GATA-4 CSCs from long-term bulk-cultured c-kitpos CSCs isolated from adult rat hearts. When c-kitpos GATA-4 high expressing clonal CSCs (cCSCs were co-cultured with adult rat ventricular cardiomyocytes, we observed increased survival and contractility of the cardiomyocytes, compared to cardiomyocytes cultured alone, co-cultured with fibroblasts or c-kitpos GATA-4 low expressing cCSCs. When analysed by ELISA, the concentration of IGF-1 was significantly increased in the c-kitpos GATA-4 high cCSC/cardiomyocyte co-cultures and there was a significant correlation between IGF-1 concentration and cardiomyocyte survival. We showed the activation of the IGF-1 receptor and its downstream molecular targets in cardiomyocytes co-cultured with c-kitpos GATA-4 high cCSCs but not in cardiomyocytes that were cultured alone, co-cultured with fibroblasts or c-kitpos GATA-4 low cCSCs. Addition of a blocking antibody specific to the IGF-1 receptor inhibited the survival of cardiomyocytes and prevented the activation of its signalling in cardiomyocytes in the c-kitpos GATA-4 high cCSC/cardiomyocyte co-culture system. IGF-1 supplementation or IGF-1 high conditioned medium taken from the co-culture of c-kitpos GATA-4 high cCSCs plus cardiomyocytes did extend the survival and contractility of cardiomyocytes cultured alone and cardiomyocytes co-cultured with c-kitpos GATA-4 low cCSCs.c-kitpos GATA-4 high cCSCs exert a paracrine survival effect on cardiomyocytes through induction of the IGF-1R and signalling pathway.

  14. Receptor protein tyrosine phosphatase alpha enhances rheumatoid synovial fibroblast signaling and promotes arthritis in mice

    NARCIS (Netherlands)

    Stanford, Stephanie M; Svensson, Mattias N D; Sacchetti, Cristiano; Pilo, Caila A; Wu, Dennis J; Kiosses, William B; Hellvard, Annelie; Bergum, Brith; Aleman Muench, German R; Elly, Christian; Liu, Yun-Cai; den Hertog, Jeroen; Elson, Ari; Sap, Jan; Mydel, Piotr; Boyle, David L; Corr, Maripat; Firestein, Gary S; Bottini, Nunzio

    2016-01-01

    OBJECTIVE: During rheumatoid arthritis (RA), fibroblast-like synoviocytes (FLS) critically promote disease pathogenesis by aggressively invading the joint extracellular matrix. The focal adhesion kinase (FAK) signaling pathway is emerging as a contributor to RA FLS anomalous behavior. The receptor

  15. The Role of Stat3 Activation in Androgen Receptor Signaling and Prostate Cancer

    National Research Council Canada - National Science Library

    Gao, Allen C

    2006-01-01

    .... The experiments proposed in this application are based upon the hypothesis that Stat3 activation alters androgen receptor signaling pathways which in turn results in the loss of growth control in prostate cancer cells...

  16. The Role of Stat3 Activation in Androgen Receptor Signaling and Prostate Cancer

    National Research Council Canada - National Science Library

    Gao, Allen

    2004-01-01

    .... The experiments proposed in this application are based upon the hypothesis that stat3 activation alters androgen receptor signaling pathways, that in turn results in the loss of growth control in prostate cancer cells...

  17. The Role of Stat3 Activation in Androgen Receptor Signaling and Prostate Cancer

    National Research Council Canada - National Science Library

    Gao, Allen

    2002-01-01

    .... The experiments proposed in this application are based upon the hypothesis that Stat3 activation alters androgen receptor signaling pathways, that in turn results in the loss of growth control in prostate cancer cells...

  18. The Role of Stat3 Activation in Androgen Receptor Signaling and Prostate Cancer

    National Research Council Canada - National Science Library

    Gao, Allen C

    2005-01-01

    .... The experiments proposed in this application are based upon the hypothesis that Stat3 activation alters androgen receptor signaling pathways, that in turn results in the loss of growth control in prostate cancer cells...

  19. The Role of Stat3 Activation in Androgen Receptor Signaling and Prostate Cancer

    National Research Council Canada - National Science Library

    Gao, Allen

    2003-01-01

    .... The experiments proposed in this application are based upon the hypothesis that Stat3 activation alters androgen receptor signaling pathways, that in turn results in the loss of growth control in prostate cancer cells...

  20. Regulation of EGF Receptor Signaling by Histone Deacetylase 6 (HDAC6)-Mediated Reversible Acetylation

    National Research Council Canada - National Science Library

    Kovacs, Jeffrey J

    2005-01-01

    One of the hallmarks of cancer is uncontrolled cell growth and proliferation. In cells, a group of proteins called growth factor receptors are responsible for responding to the signals that trigger proliferation...

  1. β1-adrenergic receptors activate two distinct signaling pathways in striatal neurons

    Science.gov (United States)

    Meitzen, John; Luoma, Jessie I.; Stern, Christopher M.; Mermelstein, Paul G.

    2010-01-01

    Monoamine action in the dorsal striatum and nucleus accumbens plays essential roles in striatal physiology. Although research often focuses on dopamine and its receptors, norepinephrine and adrenergic receptors are also crucial in regulating striatal function. While noradrenergic neurotransmission has been identified in the striatum, little is known regarding the signaling pathways activated by β-adrenergic receptors in this brain region. Using cultured striatal neurons, we characterized a novel signaling pathway by which activation of β1-adrenergic receptors leads to the rapid phosphorylation of cAMP Response Element Binding Protein (CREB), a transcription-factor implicated as a molecular switch underlying long-term changes in brain function. Norepinephrine-mediated CREB phosphorylation requires β1-adrenergic receptor stimulation of a receptor tyrosine kinase, ultimately leading to the activation of a Ras/Raf/MEK/MAPK/MSK signaling pathway. Activation of β1-adrenergic receptors also induces CRE-dependent transcription and increased c-fos expression. In addition, stimulation of β1-adrenergic receptors produces cAMP production, but surprisingly, β1-adrenergic receptor activation of adenylyl cyclase was not functionally linked to rapid CREB phosphorylation. These findings demonstrate that activation of β1-adrenergic receptors on striatal neurons can stimulate two distinct signaling pathways. These adrenergic actions can produce long-term changes in gene expression, as well as rapidly modulate cellular physiology. By elucidating the mechanisms by which norepinephrine and β1-adrenergic receptor activation affects striatal physiology, we provide the means to more fully understand the role of monoamines in modulating striatal function, specifically how norepinephrine and β1-adrenergic receptors may affect striatal physiology. PMID:21143600

  2. ITAM-like signalling for efficient phagocytosis : The paradigm of the granulocyte receptor CEACAM3

    OpenAIRE

    Pils, Stefan

    2010-01-01

    Human CEACAM3 is a tailor-made receptor of the innate immune system to fight pathogens exploiting epithelial CEACAM-family members for colonisation and invasion of their host. Previous studies established CEACAM3 as the receptor facilitating rapid phagocytosis and elimination of N. gonorrhoeae by human granulocytes. The studies reported here set out to shed light on the evolution of this highly specialised receptor and the associated signalling machinery.CEACAM3 arose from exon shuffling afte...

  3. 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...

  4. The role of Ryk and Ror receptor tyrosine kinases in Wnt signal transduction

    NARCIS (Netherlands)

    Green, J.; Nusse, R.; van Amerongen, R.

    2014-01-01

    Receptor tyrosine kinases of the Ryk and Ror families were initially classified as orphan receptors because their ligands were unknown. They are now known to contain functional extracellular Wnt-binding domains and are implicated in Wnt-signal transduction in multiple species. Although their

  5. PKCζ regulates Notch receptor routing and activity in a Notch signaling-dependent manner

    NARCIS (Netherlands)

    Sjöqvist, M.; Antfolk, D.; Ferraris, S.; Rraklli, V.; Haga, C.; Antila, C.; Mutvei, A.; Imanishi, S.Y.; Holmberg, J.; Jin, S.; Eriksson, J.E.; Lendahl, U.; Sahlgren, C.M.

    Activation of Notch signaling requires intracellular routing of the receptor, but the mechanisms controlling the distinct steps in the routing process is poorly understood. We identify PKCζ as a key regulator of Notch receptor intracellular routing. When PKCζ was inhibited in the developing chick

  6. In vivo characterization of high Basal signaling from the ghrelin receptor

    DEFF Research Database (Denmark)

    Petersen, Pia Steen; Woldbye, David P D; Madsen, Andreas Nygaard

    2009-01-01

    The receptor for the orexigenic peptide, ghrelin, is one of the most constitutively active 7TM receptors known, as demonstrated under in vitro conditions. Change in expression of a constitutively active receptor is associated with change in signaling independent of the endogenous ligand. In the f......The receptor for the orexigenic peptide, ghrelin, is one of the most constitutively active 7TM receptors known, as demonstrated under in vitro conditions. Change in expression of a constitutively active receptor is associated with change in signaling independent of the endogenous ligand....... In the following study, we found that the expression of the ghrelin receptor in the hypothalamus was up-regulated approximately 2-fold in rats both during 48-h fasting and by streptozotocin-induced hyperphagia. In a separate experiment, to probe for the effect of the high basal signaling of the ghrelin receptor...... in vivo, we used intracerebroventricular administration by osmotic pumps of a peptide [D-Arg(1), D-Phe(5), D-Trp(7,9), Leu(11)]-substance P. This peptide selectively displays inverse agonism at the ghrelin receptor as compared with an inactive control peptide with just a single amino acid substitution...

  7. P2X receptor-mediated ATP purinergic signaling in health and disease

    Directory of Open Access Journals (Sweden)

    Jiang LH

    2012-09-01

    Full Text Available Lin-Hua JiangSchool of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds, United KingdomAbstract: Purinergic P2X receptors are plasma membrane proteins present in a wide range of mammalian cells where they act as a cellular sensor, enabling cells to detect and respond to extracellular adenosine triphosphate (ATP, an important signaling molecule. P2X receptors function as ligand-gated Ca2+-permeable cationic channels that open upon ATP binding to elevate intracellular Ca2+ concentrations and cause membrane depolarization. In response to sustained activation, P2X receptors induce formation of a pore permeable to large molecules. P2X receptors also interact with distinct functional proteins and membrane lipids to form specialized signaling complexes. Studies have provided compelling evidence to show that such P2X receptor-mediated ATP-signaling mechanisms determine and regulate a growing number and diversity of important physiological processes, including neurotransmission, muscle contraction, and cytokine release. There is accumulating evidence to support strong causative relationships of altered receptor expression and function with chronic pain, inflammatory diseases, cancers, and other pathologies or diseases. Numerous high throughput screening drug discovery programs and preclinical studies have thus far demonstrated the proof of concepts that the P2X receptors are druggable targets and selective receptor antagonism is a promising therapeutics approach. This review will discuss the recent progress in understanding the mammalian P2X receptors with respect to the ATP-signaling mechanisms, physiological and pathophysiological roles, and development and preclinical studies of receptor antagonists.Keywords: extracellular ATP, ion channel, large pore, signaling complex, chronic pain, inflammatory diseases

  8. Ethylene Regulates Levels of Ethylene Receptor/CTR1 Signaling Complexes in Arabidopsis thaliana*

    Science.gov (United States)

    Shakeel, Samina N.; Gao, Zhiyong; Amir, Madiha; Chen, Yi-Feng; Rai, Muneeza Iqbal; Haq, Noor Ul; Schaller, G. Eric

    2015-01-01

    The plant hormone ethylene is perceived by a five-member family of receptors in Arabidopsis thaliana. The receptors function in conjunction with the Raf-like kinase CTR1 to negatively regulate ethylene signal transduction. CTR1 interacts with multiple members of the receptor family based on co-purification analysis, interacting more strongly with receptors containing a receiver domain. Levels of membrane-associated CTR1 vary in response to ethylene, doing so in a post-transcriptional manner that correlates with ethylene-mediated changes in levels of the ethylene receptors ERS1, ERS2, EIN4, and ETR2. Interactions between CTR1 and the receptor ETR1 protect ETR1 from ethylene-induced turnover. Kinetic and dose-response analyses support a model in which two opposing factors control levels of the ethylene receptor/CTR1 complexes. Ethylene stimulates the production of new complexes largely through transcriptional induction of the receptors. However, ethylene also induces turnover of receptors, such that levels of ethylene receptor/CTR1 complexes decrease at higher ethylene concentrations. Implications of this model for ethylene signaling are discussed. PMID:25814663

  9. Quantitative phosphoproteomics dissection of seven-transmembrane receptor signaling using full and biased agonists

    DEFF Research Database (Denmark)

    Christensen, Gitte L; Kelstrup, Christian D; Lyngsø, Christina

    2010-01-01

    (q)-dependent and -independent AT(1)R signaling. This study provides substantial novel insight into angiotensin II signal transduction and is the first study dissecting the differences between a full agonist and a biased agonist from a 7TMR on a systems-wide scale. Importantly, it reveals a previously unappreciated diversity......Seven-transmembrane receptors (7TMRs) signal through the well described heterotrimeric G proteins but can also activate G protein-independent signaling pathways of which the impact and complexity are less understood. The angiotensin II type 1 receptor (AT(1)R) is a prototypical 7TMR...... and quantity of Galpha(q) protein-independent signaling and uncovers novel signaling pathways. We foresee that the amount and diversity of G protein-independent signaling may be more pronounced than previously recognized for other 7TMRs as well. Quantitative mass spectrometry is a promising tool for evaluation...

  10. Molecular, pharmacological, and signaling properties of octopamine receptors from honeybee (Apis mellifera) brain.

    Science.gov (United States)

    Balfanz, Sabine; Jordan, Nadine; Langenstück, Teresa; Breuer, Johanna; Bergmeier, Vera; Baumann, Arnd

    2014-04-01

    G protein-coupled receptors are important regulators of cellular signaling processes. Within the large family of rhodopsin-like receptors, those binding to biogenic amines form a discrete subgroup. Activation of biogenic amine receptors leads to transient changes of intracellular Ca²⁺-([Ca²⁺](i)) or 3',5'-cyclic adenosine monophosphate ([cAMP](i)) concentrations. Both second messengers modulate cellular signaling processes and thereby contribute to long-lasting behavioral effects in an organism. In vivo pharmacology has helped to reveal the functional effects of different biogenic amines in honeybees. The phenolamine octopamine is an important modulator of behavior. Binding of octopamine to its receptors causes elevation of [Ca²⁺](i) or [cAMP](i). To date, only one honeybee octopamine receptor that induces Ca²⁺ signals has been molecularly and pharmacologically characterized. Here, we examined the pharmacological properties of four additional honeybee octopamine receptors. When heterologously expressed, all receptors induced cAMP production after binding to octopamine with EC₅₀(s) in the nanomolar range. Receptor activity was most efficiently blocked by mianserin, a substance with antidepressant activity in vertebrates. The rank order of inhibitory potency for potential receptor antagonists was very similar on all four honeybee receptors with mianserin > cyproheptadine > metoclopramide > chlorpromazine > phentolamine. The subroot of octopamine receptors activating adenylyl cyclases is the largest that has so far been characterized in arthropods, and it should now be possible to unravel the contribution of individual receptors to the physiology and behavior of honeybees. © 2013 International Society for Neurochemistry.

  11. Recruitment of SHP-1 protein tyrosine phosphatase and signalling by a chimeric T-cell receptor-killer inhibitory receptor

    DEFF Research Database (Denmark)

    Christensen, M D; Geisler, C

    2000-01-01

    Receptors expressing the immunoreceptor tyrosine-based inhibitory motif (ITIM) in their cytoplasmic tail play an important role in the negative regulation of natural killer and B-cell activation. A subpopulation of T cells expresses the ITIM containing killer cell inhibitory receptor (KIR), which...... recognize MHC class I molecules. Following coligation of KIR with an activating receptor, the tyrosine in the ITIM is phosphorylated and the cytoplasmic protein tyrosine phosphatase SHP-1 is recruited to the ITIM via its SH2 domains. It is still not clear how SHP-1 affects T-cell receptor (TCR) signalling...... regarding total protein tyrosine phosphorylation, TCR down-regulation, mobilization of intracellular free calcium, or induction of the activation markers CD69 and CD25....

  12. Lipoprotein receptor LRP1 regulates leptin signaling and energy homeostasis in the adult central nervous system.

    Science.gov (United States)

    Liu, Qiang; Zhang, Juan; Zerbinatti, Celina; Zhan, Yan; Kolber, Benedict J; Herz, Joachim; Muglia, Louis J; Bu, Guojun

    2011-01-11

    Obesity is a growing epidemic characterized by excess fat storage in adipocytes. Although lipoprotein receptors play important roles in lipid uptake, their role in controlling food intake and obesity is not known. Here we show that the lipoprotein receptor LRP1 regulates leptin signaling and energy homeostasis. Conditional deletion of the Lrp1 gene in the brain resulted in an obese phenotype characterized by increased food intake, decreased energy consumption, and decreased leptin signaling. LRP1 directly binds to leptin and the leptin receptor complex and is required for leptin receptor phosphorylation and Stat3 activation. We further showed that deletion of the Lrp1 gene specifically in the hypothalamus by Cre lentivirus injection is sufficient to trigger accelerated weight gain. Together, our results demonstrate that the lipoprotein receptor LRP1, which is critical in lipid metabolism, also regulates food intake and energy homeostasis in the adult central nervous system.

  13. Lipoprotein receptor LRP1 regulates leptin signaling and energy homeostasis in the adult central nervous system.

    Directory of Open Access Journals (Sweden)

    Qiang Liu

    2011-01-01

    Full Text Available Obesity is a growing epidemic characterized by excess fat storage in adipocytes. Although lipoprotein receptors play important roles in lipid uptake, their role in controlling food intake and obesity is not known. Here we show that the lipoprotein receptor LRP1 regulates leptin signaling and energy homeostasis. Conditional deletion of the Lrp1 gene in the brain resulted in an obese phenotype characterized by increased food intake, decreased energy consumption, and decreased leptin signaling. LRP1 directly binds to leptin and the leptin receptor complex and is required for leptin receptor phosphorylation and Stat3 activation. We further showed that deletion of the Lrp1 gene specifically in the hypothalamus by Cre lentivirus injection is sufficient to trigger accelerated weight gain. Together, our results demonstrate that the lipoprotein receptor LRP1, which is critical in lipid metabolism, also regulates food intake and energy homeostasis in the adult central nervous system.

  14. Receptor activity modifying proteins (RAMPs) interact with the VPAC1 receptor: evidence for differential RAMP modulation of multiple signalling pathways

    International Nuclear Information System (INIS)

    Christopoulos, G.; Morfis, M.; Sexton, P.M.; Christopoulos, A.; Laburthe, M.; Couvineau, A.

    2001-01-01

    Full text: Receptor activity modifying proteins (RAMP) constitute a family of three accessory proteins that affect the expression and/or phenotype of the calcitonin receptor (CTR) or CTR-like receptor (CRLR). In this study we screened a range of class II G protein-coupled receptors (PTH1, PTH2, GHRH, VPAC1, VPAC2 receptors) for possible RAMP interactions by measurement of receptor-induced translocation of c-myc tagged RAMP1 or HA tagged RAMP3. Of these, only the VPAC1 receptor caused significant translocation of c-myc-RAMP1 or HA-RAMP3 to the cell surface. Co-transfection of VPAC1 and RAMPs did not alter 125 I-VIP binding and specificity. VPAC1 receptor function was subsequently analyzed through parallel determinations of cAMP accumulation and phosphoinositide (PI) hydrolysis in the presence and absence of each of the three RAMPs. In contrast to CTR-RAMP interaction, where there was an increase in cAMP Pharmacologisand a decrease in PI hydrolysis, VPAC1-RAMP interaction was characterized by a specific increase in agonist-mediated PI hydrolysis when co-transfected with RAMP2. This change was due to an enhancement of Emax with no change in EC 50 value for VIP. No significant change in cAMP accumulation was observed. This is the first demonstration of an interaction of RAMPs with a G protein-coupled receptor outside the CTR family and may suggest a more generalized role for RAMPs in modulating G protein-coupled receptor signaling. Copyright (2001) Australasian Society of Clinical and Experimental Pharmacologists and Toxicologists

  15. ß-Adrenergic Receptor Signaling and Modulation of Long-Term Potentiation in the Mammalian Hippocampus

    Science.gov (United States)

    O'Dell, Thomas J.; Connor, Steven A.; Guglietta, Ryan; Nguyen, Peter V.

    2015-01-01

    Encoding new information in the brain requires changes in synaptic strength. Neuromodulatory transmitters can facilitate synaptic plasticity by modifying the actions and expression of specific signaling cascades, transmitter receptors and their associated signaling complexes, genes, and effector proteins. One critical neuromodulator in the…

  16. MicroRNAs regulate B-cell receptor signaling-induced apoptosis

    NARCIS (Netherlands)

    Kluiver, J. L.; Chen, C-Z

    Apoptosis induced by B-cell receptor (BCR) signaling is critical for antigen-driven selection, a process critical to tolerance and immunity. Here, we examined the roles of microRNAs (miRNAs) in BCR signaling-induced apoptosis using the widely applied WEHI-231 model. Comparison of miRNA levels in

  17. β-Adrenergic receptor signaling and modulation of long-term potentiation in the mammalian hippocampus

    OpenAIRE

    O'Dell, Thomas J.; Connor, Steven A.; Guglietta, Ryan; Nguyen, Peter V.

    2015-01-01

    Encoding new information in the brain requires changes in synaptic strength. Neuromodulatory transmitters can facilitate synaptic plasticity by modifying the actions and expression of specific signaling cascades, transmitter receptors and their associated signaling complexes, genes, and effector proteins. One critical neuromodulator in the mammalian brain is norepinephrine (NE), which regulates multiple brain functions such as attention, perception, arousal, sleep, learning, and memory. The m...

  18. Signaling by purinergic receptors and channels in the pituitary gland

    Czech Academy of Sciences Publication Activity Database

    Stojilkovic, S. S.; He, M. L.; Koshimizu, T.; Balík, A.; Zemková, Hana

    2010-01-01

    Roč. 314, č. 2 (2010), s. 184-191 ISSN 0303-7207 R&D Projects: GA ČR(CZ) GA305/07/0681 Institutional research plan: CEZ:AV0Z50110509 Keywords : purinergic receptors * ATP * anterior pituitary Subject RIV: ED - Physiology Impact factor: 4.119, year: 2010

  19. Pattern-recognition receptors: signaling pathways and dysregulation in canine chronic enteropathies-brief review.

    Science.gov (United States)

    Heilmann, Romy M; Allenspach, Karin

    2017-11-01

    Pattern-recognition receptors (PRRs) are expressed by innate immune cells and recognize pathogen-associated molecular patterns (PAMPs) as well as endogenous damage-associated molecular pattern (DAMP) molecules. With a large potential for synergism or convergence between their signaling pathways, PRRs orchestrate a complex interplay of cellular mediators and transcription factors, and thus play a central role in homeostasis and host defense. Aberrant activation of PRR signaling, mutations of the receptors and/or their downstream signaling molecules, and/or DAMP/PAMP complex-mediated receptor signaling can potentially lead to chronic auto-inflammatory diseases or development of cancer. PRR signaling pathways appear to also present an interesting new avenue for the modulation of inflammatory responses and to serve as potential novel therapeutic targets. Evidence for a dysregulation of the PRR toll-like receptor (TLR)2, TLR4, TLR5, and TLR9, nucleotide-binding oligomerization domain-containing protein (NOD)2, and the receptor of advanced glycation end products (RAGE) exists in dogs with chronic enteropathies. We describe the TLR, NOD2, and RAGE signaling pathways and evaluate the current veterinary literature-in comparison to human medicine-to determine the role of TLRs, NOD2, and RAGE in canine chronic enteropathies.

  20. DMPD: G-protein-coupled receptor expression, function, and signaling in macrophages. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 17456803 G-protein-coupled receptor expression, function, and signaling in macropha...2007 Apr 24. (.png) (.svg) (.html) (.csml) Show G-protein-coupled receptor expression, function, and signali...ng in macrophages. PubmedID 17456803 Title G-protein-coupled receptor expression, function

  1. Intercellular calcium signaling occurs between human osteoblasts and osteoclasts and requires activation of osteoclast P2X7 receptors

    DEFF Research Database (Denmark)

    Jørgensen, Niklas R; Henriksen, Zanne; Sørensen, Ole

    2002-01-01

    that human osteoclasts expressed functional P2Y1 receptors, but, unexpectedly, desensitization of P2Y1 did not block calcium signaling to osteoclasts. We also found that osteoclasts expressed functional P2X7 receptors and showed that pharmacological inhibition of these receptors blocked calcium signaling...

  2. Purinergic receptors have different effects in rat exocrine pancreas. Calcium signals monitored by fura-2 using confocal microscopy

    DEFF Research Database (Denmark)

    Novak, Ivana; Nitschke, Roland; Amstrup, Jan

    2002-01-01

    Pancreatic ducts have several types of purinergic P2 receptors, however, nothing is known about P2 receptors in acini. The aim was to establish whether acini express functional P2 receptors coupled to intracellular Ca2+ signals and to measure the signals ratiometrically in a confocal laser scanning...

  3. Quantitative phosphoproteomics dissection of 7TM receptor signaling using full and biased agonists

    DEFF Research Database (Denmark)

    Christensen, Gitte L; Kelstrup, Christian D; Lyngsø, Christina

    2010-01-01

    only activates the Gaq protein-independent signaling.e quantified more than ten thousand phosphorylation sites of which 1183 were regulated by Angiotensin II or its analogue SII Angiotensin II. 36% of the AT1R regulated phosphorylations were regulated by SII Angiotensin II. Analysis of phosphorylation...... into Angiotensin II signal transduction and is the first study dissecting the differences between a full agonist and a biased agonist from a 7TMR on a systems-wide scale. Importantly, it reveals a previously unappreciated diversity and quantity of Gaq protein-independent signaling and uncovers novel signaling......Seven-transmembrane receptors (7TMRs) signal through the well described heterotrimeric G proteins, but can also activate G protein-independent signaling pathways of which the impact and complexity are less understood. The Angiotensin II type 1 receptor (AT1R) is a prototypical 7TMR and an important...

  4. Plant immune and growth receptors share common signalling components but localise to distinct plasma membrane nanodomains.

    Science.gov (United States)

    Bücherl, Christoph A; Jarsch, Iris K; Schudoma, Christian; Segonzac, Cécile; Mbengue, Malick; Robatzek, Silke; MacLean, Daniel; Ott, Thomas; Zipfel, Cyril

    2017-03-06

    Cell surface receptors govern a multitude of signalling pathways in multicellular organisms. In plants, prominent examples are the receptor kinases FLS2 and BRI1, which activate immunity and steroid-mediated growth, respectively. Intriguingly, despite inducing distinct signalling outputs, both receptors employ common downstream signalling components, which exist in plasma membrane (PM)-localised protein complexes. An important question is thus how these receptor complexes maintain signalling specificity. Live-cell imaging revealed that FLS2 and BRI1 form PM nanoclusters. Using single-particle tracking we could discriminate both cluster populations and we observed spatiotemporal separation between immune and growth signalling platforms. This finding was confirmed by visualising FLS2 and BRI1 within distinct PM nanodomains marked by specific remorin proteins and differential co-localisation with the cytoskeleton. Our results thus suggest that signalling specificity between these pathways may be explained by the spatial separation of FLS2 and BRI1 with their associated signalling components within dedicated PM nanodomains.

  5. Evaluation of Intracellular Signaling Downstream Chimeric Antigen Receptors.

    Directory of Open Access Journals (Sweden)

    Hannah Karlsson

    Full Text Available CD19-targeting CAR T cells have shown potency in clinical trials targeting B cell leukemia. Although mainly second generation (2G CARs carrying CD28 or 4-1BB have been investigated in patients, preclinical studies suggest that third generation (3G CARs with both CD28 and 4-1BB have enhanced capacity. However, little is known about the intracellular signaling pathways downstream of CARs. In the present work, we have analyzed the signaling capacity post antigen stimulation in both 2G and 3G CARs. 3G CAR T cells expanded better than 2G CAR T cells upon repeated stimulation with IL-2 and autologous B cells. An antigen-driven accumulation of CAR+ cells was evident post antigen stimulation. The cytotoxicity of both 2G and 3G CAR T cells was maintained by repeated stimulation. The phosphorylation status of intracellular signaling proteins post antigen stimulation showed that 3G CAR T cells had a higher activation status than 2G. Several proteins involved in signaling downstream the TCR were activated, as were proteins involved in the cell cycle, cell adhesion and exocytosis. In conclusion, 3G CAR T cells had a higher degree of intracellular signaling activity than 2G CARs which may explain the increased proliferative capacity seen in 3G CAR T cells. The study also indicates that there may be other signaling pathways to consider when designing or evaluating new generations of CARs.

  6. Arabidopsis CPR5 regulates ethylene signaling via molecular association with the ETR1 receptor.

    Science.gov (United States)

    Wang, Feifei; Wang, Lijuan; Qiao, Longfei; Chen, Jiacai; Pappa, Maria Belen; Pei, Haixia; Zhang, Tao; Chang, Caren; Dong, Chun-Hai

    2017-11-01

    The plant hormone ethylene plays various functions in plant growth, development and response to environmental stress. Ethylene is perceived by membrane-bound ethylene receptors, and among the homologous receptors in Arabidopsis, the ETR1 ethylene receptor plays a major role. The present study provides evidence demonstrating that Arabidopsis CPR5 functions as a novel ETR1 receptor-interacting protein in regulating ethylene response and signaling. Yeast split ubiquitin assays and bi-fluorescence complementation studies in plant cells indicated that CPR5 directly interacts with the ETR1 receptor. Genetic analyses indicated that mutant alleles of cpr5 can suppress ethylene insensitivity in both etr1-1 and etr1-2, but not in other dominant ethylene receptor mutants. Overexpression of Arabidopsis CPR5 either in transgenic Arabidopsis plants, or ectopically in tobacco, significantly enhanced ethylene sensitivity. These findings indicate that CPR5 plays a critical role in regulating ethylene signaling. CPR5 is localized to endomembrane structures and the nucleus, and is involved in various regulatory pathways, including pathogenesis, leaf senescence, and spontaneous cell death. This study provides evidence for a novel regulatory function played by CPR5 in the ethylene receptor signaling pathway in Arabidopsis. © 2017 Institute of Botany, Chinese Academy of Sciences.

  7. Insulin signaling inhibits the 5-HT2C receptor in choroid plexus via MAP kinase

    Directory of Open Access Journals (Sweden)

    Guan Kunliang

    2003-06-01

    Full Text Available Abstract Background G protein-coupled receptors (GPCRs interact with heterotrimeric GTP-binding proteins (G proteins to modulate acute changes in intracellular messenger levels and ion channel activity. In contrast, long-term changes in cellular growth, proliferation and differentiation are often mediated by tyrosine kinase receptors and certain GPCRs by activation of mitogen-activated protein (MAP kinases. Complex interactions occur between these signaling pathways, but the specific mechanisms of such regulatory events are not well-understood. In particular it is not clear whether GPCRs are modulated by tyrosine kinase receptor-MAP kinase pathways. Results Here we describe tyrosine kinase receptor regulation of a GPCR via MAP kinase. Insulin reduced the activity of the 5-HT2C receptor in choroid plexus cells which was blocked by the MAP kinase kinase (MEK inhibitor, PD 098059. We demonstrate that the inhibitory effect of insulin and insulin-like growth factor type 1 (IGF-1 on the 5-HT2C receptor is dependent on tyrosine kinase, RAS and MAP kinase. The effect may be receptor-specific: insulin had no effect on another GPCR that shares the same G protein signaling pathway as the 5-HT2C receptor. This effect is also direct: activated MAP kinase mimicked the effect of insulin, and removing a putative MAP kinase site from the 5-HT2C receptor abolished the effect of insulin. Conclusion These results show that insulin signaling can inhibit 5-HT2C receptor activity and suggest that MAP kinase may play a direct role in regulating the function of a specific GPCR.

  8. Interplay between TGF-β signaling and receptor tyrosine kinases in tumor development.

    Science.gov (United States)

    Shi, Qiaoni; Chen, Ye-Guang

    2017-10-01

    Transforming growth factor-β (TGF-β) signaling regulates cell proliferation, differentiation, migration and death, and plays a critical role in embryogenesis and tissue homeostasis. Its deregulation results in various diseases including tumor formation. Receptor tyrosine kinases (RTKs), such as epidermal growth factor receptor (EGFR), fibroblast growth factor receptor (FGFR), vascular endothelial growth factor receptor (VEGFR) and platelet-derived growth factor receptor (PDGFR), also play key roles in the development and progression of many types of tumors. It has been realized that TGF-β signaling and RTK pathways interact with each other and their interplay is important for cancer development. They are mutually regulated and cooperatively modulate cell survival and migration, epithelial-mesenchymal transition, and tumor microenvironment to accelerate tumorigenesis and tumor metastasis. RTKs can modulate Smad-dependent transcription or cooperate with TGF-β to potentiate its oncogenic activity, while TGF-β signaling can in turn control RTK signaling by regulating their activities or expression. This review summarizes current understandings of the interplay between TGF-β signaling and RTKs and its influence on tumor development.

  9. A model for the biosynthesis and transport of plasma membrane-associated signaling receptors to the cell surface

    Directory of Open Access Journals (Sweden)

    Sorina Claudia Popescu

    2012-04-01

    Full Text Available Intracellular protein transport is emerging as critical in determining the outcome of receptor-activated signal transduction pathways. In plants, relatively little is known about the nature of the molecular components and mechanisms involved in coordinating receptor synthesis and transport to the cell surface. Recent advances in this field indicate that signaling pathways and intracellular transport machinery converge and coordinate to render receptors competent for signaling at their plasma membrane activity sites. The biogenesis and transport to the cell surface of signaling receptors appears to require both general trafficking and receptor-specific factors. Several molecular determinants, residing or associated with compartments of the secretory pathway and known to influence aspects in receptor biogenesis, are discussed and integrated into a predictive cooperative model for the functional expression of signaling receptors at the plasma membrane.

  10. Association of cannabis use during adolescence, prefrontal CB1 receptor signaling and schizophrenia

    Directory of Open Access Journals (Sweden)

    Adriana eCaballero

    2012-05-01

    Full Text Available The cannabinoid receptor 1 (CB1R is the G-protein coupled receptor responsible for the majority of the endocannabinoid signaling in the human brain. It is widely distributed in the limbic system, basal ganglia, and cerebellum, which are areas responsible for cognition, memory, and motor control. Because of this widespread distribution, it is not surprising that drugs that co-opt CB1R have expected behavioral outcomes consistent with dysregulated signaling from these areas (e.g. memory loss, cognitive deficits, etc. In the context of this review, we present evidence for the role of CB1R signaling in the prefrontal cortex (PFC, an area involved in executive functions, with emphasis on the developmental regulation of CB1R signaling in the acquisition of mature PFC function. We further hypothesize how alterations of CB1R signaling specifically during adolescent maturation might confer liability to psychiatric disorders.

  11. Imaging of persistent cAMP signaling by internalized G protein-coupled receptors.

    Science.gov (United States)

    Calebiro, Davide; Nikolaev, Viacheslav O; Lohse, Martin J

    2010-07-01

    G protein-coupled receptors (GPCRs) are the largest family of plasma membrane receptors. They mediate the effects of several endogenous cues and serve as important pharmacological targets. Although many biochemical events involved in GPCR signaling have been characterized in great detail, little is known about their spatiotemporal dynamics in living cells. The recent advent of optical methods based on fluorescent resonance energy transfer allows, for the first time, to directly monitor GPCR signaling in living cells. Utilizing these methods, it has been recently possible to show that the receptors for two protein/peptide hormones, the TSH and the parathyroid hormone, continue signaling to cAMP after their internalization into endosomes. This type of intracellular signaling is persistent and apparently triggers specific cellular outcomes. Here, we review these recent data and explain the optical methods used for such studies. Based on these findings, we propose a revision of the current model of the GPCR-cAMP signaling pathway to accommodate receptor signaling at endosomes.

  12. Evidence for cooperative signal triggering at the extracellular loops of the TSH receptor.

    Science.gov (United States)

    Kleinau, Gunnar; Jaeschke, Holger; Mueller, Sandra; Raaka, Bruce M; Neumann, Susanne; Paschke, Ralf; Krause, Gerd

    2008-08-01

    The mechanisms governing transition of the thyroid stimulating hormone (TSH) receptor (TSHR) from basal to active conformations are poorly understood. Considering that constitutively activating mutations (CAMs) and inactivating mutations in each of the extracellular loops (ECLs) trigger only partial TSHR activation or inactivation, respectively, we hypothesized that full signaling occurs via multiple extracellular signal propagation events. Therefore, individual CAMs in the extracellular region were combined to create double and triple mutants. In support of our hypothesis, combinations of mutants in the ECLs are in some cases additive, while in others they are even synergistic, with triple mutant I486A/I568V/V656F exhibiting a 70-fold increase in TSH-independent signaling. The proximity but likely different spatial orientation of the residues of activating and inactivating mutations in each ECL supports a dual functionality to facilitate signal induction and conduction, respectively. This is the first report for G-protein coupled receptors, suggesting that multiple and cooperative signal propagating events at all three ECLs are required for full receptor activation. Our findings provide new insights concerning molecular signal transmission from extracellular domains toward the transmembrane helix bundle of the glycoprotein hormone receptors.

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

    Science.gov (United States)

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

    1997-05-23

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

  14. Age-related changes in expression and signaling of TAM receptor inflammatory regulators in monocytes.

    Science.gov (United States)

    Wang, Xiaomei; Malawista, Anna; Qian, Feng; Ramsey, Christine; Allore, Heather G; Montgomery, Ruth R

    2018-02-09

    The multifactorial immune deterioration in aging--termed "inflamm-aging"--is comprised of a state of low-grade, chronic inflammation and complex dysregulation of responses to immune stimulation. The TAM family (Tyro 3, Axl, and Mer) of receptor tyrosine kinases are negative regulators of Toll like receptor-mediated immune responses that broadly inhibit cytokine receptor cascades to inhibit inflammation. Here we demonstrate elevated expression of TAM receptors in monocytes of older adults, and an age-dependent difference in signaling mediator AKT resulting in dysregulated responses to signaling though Mer. Our results may be especially significant in tissue, where levels of Mer are highest, and may present avenues for modulation of chronic tissue inflammation noted in aging.

  15. Recent Advances on the Role of G Protein-Coupled Receptors in Hypoxia-Mediated Signaling

    OpenAIRE

    Lappano, Rosamaria; Rigiracciolo, Damiano; De Marco, Paola; Avino, Silvia; Cappello, Anna Rita; Rosano, Camillo; Maggiolini, Marcello; De Francesco, Ernestina Marianna

    2016-01-01

    G protein-coupled receptors (GPCRs) are cell surface proteins mainly involved in signal transmission; however, they play a role also in several pathophysiological conditions. Chemically heterogeneous molecules like peptides, hormones, lipids, and neurotransmitters activate second messengers and induce several biological responses by binding to these seven transmembrane receptors, which are coupled to heterotrimeric G proteins. Recently, additional molecular mechanisms have been involved in GP...

  16. Signal Transduction of Sphingosine-1-Phosphate G Protein—Coupled Receptors

    Directory of Open Access Journals (Sweden)

    Nicholas Young

    2006-01-01

    Full Text Available Sphingosine-1-phosphate (S1P is a bioactive lipid capable of eliciting dramatic effects in a variety of cell types. Signaling by this molecule is by a family of five G protein—coupled receptors named S1P1–5 that signal through a variety of pathways to regulate cell proliferation, migration, cytoskeletal organization, and differentiation. These receptors are expressed in a wide variety of tissues and cell types, and their cellular effects contribute to important biological and pathological functions of S1P in many processes, including angiogenesis, vascular development, lymphocyte trafficking, and cancer. This review will focus on the current progress in the field of S1P receptor signaling and biology.

  17. Non-genomic actions of aldosterone: From receptors and signals to membrane targets.

    LENUS (Irish Health Repository)

    2012-02-01

    In tissues which express the mineralocorticoid receptor (MR), aldosterone modulates the expression of membrane targets such as the subunits of the epithelial Na(+) channel, in combination with important signalling intermediates such as serum and glucocorticoid-regulated kinase-1. In addition, the rapid \\'non-genomic\\' activation of protein kinases and secondary messenger signalling cascades has also been detected in aldosterone-sensitive tissues of the nephron, distal colon and cardiovascular system. These rapid actions are variously described as being coupled to MR or to an as yet unidentified, membrane-associated aldosterone receptor. The rapidly activated signalling cascades add a level of fine-tuning to the activity of aldosterone-responsive membrane transporters and also modulate the aldosterone-induced changes in gene expression through receptor and transcription factor phosphorylation.

  18. Non-genomic actions of aldosterone: From receptors and signals to membrane targets.

    LENUS (Irish Health Repository)

    Dooley, Ruth

    2011-07-26

    In tissues which express the mineralocorticoid receptor (MR), aldosterone modulates the expression of membrane targets such as the subunits of the epithelial Na(+) channel, in combination with important signalling intermediates such as serum and glucocorticoid-regulated kinase-1. In addition, the rapid \\'non-genomic\\' activation of protein kinases and secondary messenger signalling cascades has also been detected in aldosterone-sensitive tissues of the nephron, distal colon and cardiovascular system. These rapid actions are variously described as being coupled to MR or to an as yet unidentified, membrane-associated aldosterone receptor. The rapidly activated signalling cascades add a level of fine-tuning to the activity of aldosterone-responsive membrane transporters and also modulate the aldosterone-induced changes in gene expression through receptor and transcription factor phosphorylation.

  19. Delineation of the GPRC6A Receptor Signaling Pathways Using a Mammalian Cell Line Stably Expressing the Receptor

    DEFF Research Database (Denmark)

    Jacobsen, Stine Engesgaard; Nørskov-Lauritsen, Lenea; Thomsen, Alex Rojas Bie

    2013-01-01

    receptor has been suggested to couple to multiple G protein classes albeit via indirect methods. Thus, the exact ligand preferences and signaling pathways are yet to be elucidated. In the present study, we generated a Chinese hamster ovary (CHO) cell line that stably expresses mouse GPRC6A. In an effort...... and divalent cations, and for the first time, we conclusively show that these responses are mediated through the Gq pathway. We were not able to confirm previously published data demonstrating Gi- and Gs-mediated signaling; neither could we detect agonistic activity of testosterone and osteocalcin. Generation...... of the stable CHO cell line with robust receptor responsiveness and optimization of the highly sensitive homogeneous time resolved fluorescence technology allow fast assessment of Gq activation without previous manipulations like cotransfection of mutated G proteins. This cell-based assay system for GPRC6A...

  20. Activation of GABAB receptors inhibits protein kinase B /Glycogen Synthase Kinase 3 signaling

    Directory of Open Access Journals (Sweden)

    Lu Frances Fangjia

    2012-11-01

    Full Text Available Abstract Accumulated evidence has suggested that potentiation of cortical GABAergic inhibitory neurotransmission may be a key mechanism in the treatment of schizophrenia. However, the downstream molecular mechanisms related to GABA potentiation remain unexplored. Recent studies have suggested that dopamine D2 receptor antagonists, which are used in the clinical treatment of schizophrenia, modulate protein kinase B (Akt/glycogen synthase kinase (GSK-3 signaling. Here we report that activation of GABAB receptors significantly inhibits Akt/GSK-3 signaling in a β-arrestin-dependent pathway. Agonist stimulation of GABAB receptors enhances the phosphorylation of Akt (Thr-308 and enhances the phosphorylation of GSK-3α (Ser-21/β (Ser-9 in both HEK-293T cells expressing GABAB receptors and rat hippocampal slices. Furthermore, knocking down the expression of β-arrestin2 using siRNA abolishes the GABAB receptor-mediated modulation of GSK-3 signaling. Our data may help to identify potentially novel targets through which GABAB receptor agents may exert therapeutic effects in the treatment of schizophrenia.

  1. Phytomelatonin receptor PMTR1-mediated signaling regulates stomatal closure in Arabidopsis thaliana.

    Science.gov (United States)

    Wei, Jian; Li, Dong-Xu; Zhang, Jia-Rong; Shan, Chi; Rengel, Zed; Song, Zhong-Bang; Chen, Qi

    2018-04-27

    Melatonin has been detected in plants in 1995; however, the function and signaling pathway of this putative phytohormone are largely undetermined due to a lack of knowledge about its receptor. Here, we discovered the first phytomelatonin receptor (CAND2/PMTR1) in Arabidopsis thaliana and found that melatonin governs the receptor-dependent stomatal closure. The application of melatonin induced stomatal closure through the heterotrimeric G protein α subunit-regulated H 2 O 2 and Ca 2+ signals. The Arabidopsis mutant lines lacking AtCand2 that encodes a candidate G protein-coupled receptor were insensitive to melatonin-induced stomatal closure. Accordingly, the melatonin-induced H 2 O 2 production and Ca 2+ influx were completely abolished in cand2. CAND2 is a membrane protein that interacts with GPA1 and the expression of AtCand2 was tightly regulated by melatonin in various organs and guard cells. CAND2 showed saturable and specific 125 I-melatonin binding, with apparent K d (dissociation constant) of 0.73 ± 0.10 nmol/L (r 2  = .99), demonstrating this protein is a phytomelatonin receptor (PMTR1). Our results suggest that the phytomelatonin regulation of stomatal closure is dependent on its receptor CAND2/PMTR1-mediated H 2 O 2 and Ca 2+ signaling transduction cascade. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  2. Quantitative properties and receptor reserve of the IP(3) and calcium branch of G(q)-coupled receptor signaling.

    Science.gov (United States)

    Dickson, Eamonn J; Falkenburger, Björn H; Hille, Bertil

    2013-05-01

    Gq-coupled plasma membrane receptors activate phospholipase C (PLC), which hydrolyzes membrane phosphatidylinositol 4,5-bisphosphate (PIP2) into the second messengers inositol 1,4,5-trisphosphate (IP3) and diacylglycerol (DAG). This leads to calcium release, protein kinase C (PKC) activation, and sometimes PIP2 depletion. To understand mechanisms governing these diverging signals and to determine which of these signals is responsible for the inhibition of KCNQ2/3 (KV7.2/7.3) potassium channels, we monitored levels of PIP2, IP3, and calcium in single living cells. DAG and PKC are monitored in our companion paper (Falkenburger et al. 2013. J. Gen. Physiol. http://dx.doi.org/10.1085/jgp.201210887). The results extend our previous kinetic model of Gq-coupled receptor signaling to IP3 and calcium. We find that activation of low-abundance endogenous P2Y2 receptors by a saturating concentration of uridine 5'-triphosphate (UTP; 100 µM) leads to calcium release but not to PIP2 depletion. Activation of overexpressed M1 muscarinic receptors by 10 µM Oxo-M leads to a similar calcium release but also depletes PIP2. KCNQ2/3 channels are inhibited by Oxo-M (by 85%), but not by UTP (calcium responses can be elicited even after PIP2 was partially depleted by overexpressed inducible phosphatidylinositol 5-phosphatases, suggesting that very low amounts of IP3 suffice to elicit a full calcium release. Hence, weak PLC activation can elicit robust calcium signals without net PIP2 depletion or KCNQ2/3 channel inhibition.

  3. Anxiolytic-Like Effects of Increased Ghrelin Receptor Signaling in the Amygdala

    DEFF Research Database (Denmark)

    Jensen, Morten; Ratner, Cecilia; Rudenko, Olga

    2016-01-01

    BACKGROUND: Besides the well-known effects of ghrelin on adiposity and food intake regulation, the ghrelin system has been shown to regulate aspects of behavior including anxiety and stress. However, the effect of virus-mediated overexpression of the ghrelin receptor in the amygdala has...... not previously been addressed directly. METHOD: First, we examined the acute effect of peripheral ghrelin administration on anxiety- and depression-like behavior using the open field, elevated plus maze, forced swim and tail suspension tests. Next, we examined the effect of peripheral ghrelin administration...... and ghrelin receptor deficiency on stress in a familiar and social environment using the Intellicage system. Importantly, we also used a novel approach to study ghrelin receptor signaling in the brain by overexpressing the ghrelin receptor in the amygdala. We examined the effect of ghrelin receptor...

  4. A single amino acid residue controls Ca2+ signaling by an octopamine receptor from Drosophila melanogaster.

    Science.gov (United States)

    Hoff, Max; Balfanz, Sabine; Ehling, Petra; Gensch, Thomas; Baumann, Arnd

    2011-07-01

    Rhythmic activity of cells and cellular networks plays an important role in physiology. In the nervous system oscillations of electrical activity and/or second messenger concentrations are important to synchronize neuronal activity. At the molecular level, rhythmic activity can be initiated by different routes. We have recently shown that an octopamine-activated G-protein-coupled receptor (GPCR; DmOctα1Rb, CG3856) from Drosophila initiates Ca(2+) oscillations. Here, we have unraveled the molecular basis of cellular Ca(2+) signaling controlled by the DmOctα1Rb receptor using a combination of pharmacological intervention, site-directed mutagenesis, and functional cellular Ca(2+) imaging on heterologously expressed receptors. Phosphorylation of a single amino acid residue in the third intracellular loop of the GPCR by PKC is necessary and sufficient to desensitize the receptor. From its desensitized state, DmOctα1Rb is resensitized by dephosphorylation, and a new Ca(2+) signal occurs on octopamine stimulation. Our findings show that transient changes of the receptor's surface profile have a strong effect on its physiological signaling properties. We expect that the detailed knowledge of DmOctα1Rb-dependent signal transduction fosters the identification of specific drugs that can be used for GPCR-mediated pest control, since octopamine serves important physiological and behavioral functions in arthropods.

  5. Negative Regulation of Receptor Tyrosine Kinase (RTK Signaling: A Developing Field

    Directory of Open Access Journals (Sweden)

    Fernanda Ledda

    2007-01-01

    Full Text Available ophic factors control cellular physiology by activating specific receptor tyrosine kinases (RTKs. While the over activation of RTK signaling pathways is associated with cell growth and cancer, recent findings support the concept that impaired down-regulation or deactivation of RTKs may also be a mechanism involved in tumor formation. Under this perspective, the molecular determinants of RTK signaling inhibition may act as tumor-suppressor genes and have a potential role as tumor markers to monitor and predict disease progression. Here, we review the current understanding of the physiological mechanisms that attenuate RTK signaling and discuss evidence that implicates deregulation of these events in cancer.Abbreviations: BDP1: Brain-derived phosphatase 1; Cbl: Casitas B-lineage lymphoma; CIN-85: Cbl-interacting protein of 85 kDa; DER: Drosophila EGFR; EGFR: Epidermal growth factor receptor; ERK 1/2: Extracellular signal-regulated kinase 1/2; Grb2: Growth factor receptor-bound protein 2; HER2: Human epidermal growth factor receptor 2; LRIG: Leucine-rich repeats and immunoglobulin-like domain 1; MAPK: Mitogen-activated protein kinase; Mig 6: Mitogen-inducible gene 6; PTEN: Phosphatase and tensin homologue; RET: Rearranged in transformation; RTK: Receptor tyrosine kinase. SH2 domain: Src-homology 2 domain; SH3 domain: Src-homology 3 domain; Spry: Sprouty.

  6. Death receptor Fas (CD95) signaling in the central nervous system: tuning neuroplasticity?

    Science.gov (United States)

    Reich, Arno; Spering, Christopher; Schulz, Jörg B

    2008-09-01

    For over a decade, neuroscientific research has focused on processes of apoptosis and its contribution to the pathophysiology of neurological diseases. In the central nervous system, the degree of intrinsic mitochondrial-mediated apoptotic signaling expresses a cell's individual metabolic stress, whereas activation of the extrinsic death receptor-induced cascade is regarded as a sign of imbalanced cellular networks. Under physiological conditions, most neurons possess death receptors without being sensitive to receptor-mediated apoptosis. This paradox raises two questions: what is the evolutionary advantage of expressing potentially harmful proteins? How is their signaling controlled? This review summarizes the functional relevance of FasL-Fas signaling--a quintessential death ligand/receptor system--in different neurological disease models ranging from traumatic, inflammatory and ischemic to neurodegenerative processes. Furthermore, it outlines alternative non-apoptotic Fas signaling, shedding new light on its neuroplastic capacity. Finally, receptor-proximal regulatory proteins are introduced and identified as potential protagonists of disease-modifying neurological therapies.

  7. Molecular Mechanisms of SH2- and PTB-Domain-Containing Proteins in Receptor Tyrosine Kinase Signaling

    Science.gov (United States)

    Wagner, Melany J.; Stacey, Melissa M.; Liu, Bernard A.; Pawson, Tony

    2013-01-01

    Intracellular signaling is mediated by reversible posttranslational modifications (PTMs) that include phosphorylation, ubiquitination, and acetylation, among others. In response to extracellular stimuli such as growth factors, receptor tyrosine kinases (RTKs) typically dimerize and initiate signaling through phosphorylation of their cytoplasmic tails and downstream scaffolds. Signaling effectors are recruited to these phosphotyrosine (pTyr) sites primarily through Src homology 2 (SH2) domains and pTyr-binding (PTB) domains. This review describes how these conserved domains specifically recognize pTyr residues and play a major role in mediating precise downstream signaling events. PMID:24296166

  8. Molecular mechanisms of SH2- and PTB-domain-containing proteins in receptor tyrosine kinase signaling.

    Science.gov (United States)

    Wagner, Melany J; Stacey, Melissa M; Liu, Bernard A; Pawson, Tony

    2013-12-01

    Intracellular signaling is mediated by reversible posttranslational modifications (PTMs) that include phosphorylation, ubiquitination, and acetylation, among others. In response to extracellular stimuli such as growth factors, receptor tyrosine kinases (RTKs) typically dimerize and initiate signaling through phosphorylation of their cytoplasmic tails and downstream scaffolds. Signaling effectors are recruited to these phosphotyrosine (pTyr) sites primarily through Src homology 2 (SH2) domains and pTyr-binding (PTB) domains. This review describes how these conserved domains specifically recognize pTyr residues and play a major role in mediating precise downstream signaling events.

  9. Rapid Phospho-Turnover by Receptor Tyrosine Kinases Impacts Downstream Signaling and Drug Binding

    OpenAIRE

    Kleiman, Laura B.; Maiwald, Thomas; Conzelmann, Holger; Lauffenburger, Douglas A.; Sorger, Peter K.

    2011-01-01

    Epidermal growth factor receptors (ErbB1–4) are oncogenic receptor tyrosine kinases (RTKs) that regulate diverse cellular processes. In this study, we combine measurement and mathematical modeling to quantify phospho-turnover at ErbB receptors in human cells and to determine the consequences for signaling and drug binding. We find that phosphotyrosine residues on ErbB1 have half-lives of a few seconds and therefore turn over 100–1000 times in the course of a typical immediate-early response t...

  10. Heterotrimeric G Protein-coupled Receptor Signaling in Yeast Mating Pheromone Response.

    Science.gov (United States)

    Alvaro, Christopher G; Thorner, Jeremy

    2016-04-08

    The DNAs encoding the receptors that respond to the peptide mating pheromones of the budding yeastSaccharomyces cerevisiaewere isolated in 1985, and were the very first genes for agonist-binding heterotrimeric G protein-coupled receptors (GPCRs) to be cloned in any organism. Now, over 30 years later, this yeast and its receptors continue to provide a pathfinding experimental paradigm for investigating GPCR-initiated signaling and its regulation, as described in this retrospective overview. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  11. Cross-regulation of cytokine signalling: pro-inflammatory cytokines restrict IL-6 signalling through receptor internalisation and degradation.

    Science.gov (United States)

    Radtke, Simone; Wüller, Stefan; Yang, Xiang-ping; Lippok, Barbara E; Mütze, Barbara; Mais, Christine; de Leur, Hildegard Schmitz-Van; Bode, Johannes G; Gaestel, Matthias; Heinrich, Peter C; Behrmann, Iris; Schaper, Fred; Hermanns, Heike M

    2010-03-15

    The inflammatory response involves a complex interplay of different cytokines which act in an auto- or paracrine manner to induce the so-called acute phase response. Cytokines are known to crosstalk on multiple levels, for instance by regulating the mRNA stability of targeted cytokines through activation of the p38-MAPK pathway. In our study we discovered a new mechanism that answers the long-standing question how pro-inflammatory cytokines and environmental stress restrict immediate signalling of interleukin (IL)-6-type cytokines. We show that p38, activated by IL-1beta, TNFalpha or environmental stress, impairs IL-6-induced JAK/STAT signalling through phosphorylation of the common cytokine receptor subunit gp130 and its subsequent internalisation and degradation. We identify MK2 as the kinase that phosphorylates serine 782 in the cytoplasmic part of gp130. Consequently, inhibition of p38 or MK2, deletion of MK2 or mutation of crucial amino acids within the MK2 target site or the di-leucine internalisation motif blocks receptor depletion and restores IL-6-dependent STAT activation as well as gene induction. Hence, a novel negative crosstalk mechanism for cytokine signalling is described, where cytokine receptor turnover is regulated in trans by pro-inflammatory cytokines and stress stimuli to coordinate the inflammatory response.

  12. Normalization of TAM post-receptor signaling reveals a cell invasive signature for Axl tyrosine kinase.

    Science.gov (United States)

    Kimani, Stanley G; Kumar, Sushil; Davra, Viralkumar; Chang, Yun-Juan; Kasikara, Canan; Geng, Ke; Tsou, Wen-I; Wang, Shenyan; Hoque, Mainul; Boháč, Andrej; Lewis-Antes, Anita; De Lorenzo, Mariana S; Kotenko, Sergei V; Birge, Raymond B

    2016-09-06

    Tyro3, Axl, and Mertk (TAMs) are a family of three conserved receptor tyrosine kinases that have pleiotropic roles in innate immunity and homeostasis and when overexpressed in cancer cells can drive tumorigenesis. In the present study, we engineered EGFR/TAM chimeric receptors (EGFR/Tyro3, EGFR/Axl, and EGF/Mertk) with the goals to interrogate post-receptor functions of TAMs, and query whether TAMs have unique or overlapping post-receptor activation profiles. Stable expression of EGFR/TAMs in EGFR-deficient CHO cells afforded robust EGF inducible TAM receptor phosphorylation and activation of downstream signaling. Using a series of unbiased screening approaches, that include kinome-view analysis, phosphor-arrays, RNAseq/GSEA analysis, as well as cell biological and in vivo readouts, we provide evidence that each TAM has unique post-receptor signaling platforms and identify an intrinsic role for Axl that impinges on cell motility and invasion compared to Tyro3 and Mertk. These studies demonstrate that TAM show unique post-receptor signatures that impinge on distinct gene expression profiles and tumorigenic outcomes.

  13. Targeting CB2-GPR55 Receptor Heteromers Modulates Cancer Cell Signaling*

    Science.gov (United States)

    Moreno, Estefanía; Andradas, Clara; Medrano, Mireia; Caffarel, María M.; Pérez-Gómez, Eduardo; Blasco-Benito, Sandra; Gómez-Cañas, María; Pazos, M. Ruth; Irving, Andrew J.; Lluís, Carme; Canela, Enric I.; Fernández-Ruiz, Javier; Guzmán, Manuel; McCormick, Peter J.; Sánchez, Cristina

    2014-01-01

    The G protein-coupled receptors CB2 (CB2R) and GPR55 are overexpressed in cancer cells and human tumors. Because a modulation of GPR55 activity by cannabinoids has been suggested, we analyzed whether this receptor participates in cannabinoid effects on cancer cells. Here we show that CB2R and GPR55 form heteromers in cancer cells, that these structures possess unique signaling properties, and that modulation of these heteromers can modify the antitumoral activity of cannabinoids in vivo. These findings unveil the existence of previously unknown signaling platforms that help explain the complex behavior of cannabinoids and may constitute new targets for therapeutic intervention in oncology. PMID:24942731

  14. Effects of age and insulin-like growth factor-1 on rat neurotrophin receptor expression after nerve injury.

    Science.gov (United States)

    Luo, T David; Alton, Timothy B; Apel, Peter J; Cai, Jiaozhong; Barnwell, Jonathan C; Sonntag, William E; Smith, Thomas L; Li, Zhongyu

    2016-10-01

    Neurotrophin receptors, such as p75(NTR) , direct neuronal response to injury. Insulin-like growth factor-1 receptor (IGF-1R) mediates the increase in p75(NTR) during aging. The aim of this study was to examine the effect of aging and insulin-like growth factor-1 (IGF-1) treatment on recovery after peripheral nerve injury. Young and aged rats underwent tibial nerve transection with either local saline or IGF-1 treatment. Neurotrophin receptor mRNA and protein expression were quantified. Aged rats expressed elevated baseline IGF-1R (34% higher, P = 0.01) and p75(NTR) (68% h