1351
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Stengel A, Wang L, Taché Y. Stress-related alterations of acyl and desacyl ghrelin circulating levels: mechanisms and functional implications. Peptides 2011; 32:2208-17. [PMID: 21782868 PMCID: PMC3220774 DOI: 10.1016/j.peptides.2011.07.002] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/20/2011] [Revised: 07/04/2011] [Accepted: 07/05/2011] [Indexed: 12/11/2022]
Abstract
Ghrelin is the only known peripherally produced and centrally acting peptide hormone that stimulates food intake and digestive functions. Ghrelin circulates as acylated and desacylated forms and recently the acylating enzyme, ghrelin-O-acyltransferase (GOAT) and the de-acylating enzyme, thioesterase 1/lysophospholipase 1 have been identified adding new layers of complexity to the regulation of ghrelin. Stress is known to alter gastrointestinal motility and food intake and was recently shown to modify circulating ghrelin and GOAT levels with differential responses related to the type of stressors including a reduction induced by physical stressors (abdominal surgery and immunological/endotoxin injection, exercise) and elevation by metabolic (cold exposure, acute fasting and caloric restriction) and psychological stressors. However, the pathways underlying the alterations of ghrelin under these various stress conditions are still largely to be defined and may relate to stress-associated autonomic changes. There is evidence that alterations of circulating ghrelin may contribute to the neuroendocrine and behavioral responses along with sustaining the energetic requirement needed upon repeated exposure to stressors. A better understanding of these mechanisms will allow targeting components of ghrelin signaling that may improve food intake and gastric motility alterations induced by stress.
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Affiliation(s)
- Andreas Stengel
- CURE: Digestive Diseases Research Center, David Geffen School of Medicine, University of California Los Angeles and Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, CA 90073, United States.
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1352
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Ma J, Sun Q, Mi R, Zhang H. Avian influenza A virus H5N1 causes autophagy-mediated cell death through suppression of mTOR signaling. J Genet Genomics 2011; 38:533-7. [PMID: 22133684 DOI: 10.1016/j.jgg.2011.10.002] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2011] [Revised: 10/12/2011] [Accepted: 10/13/2011] [Indexed: 12/13/2022]
Abstract
Of the few avian influenza viruses that have crossed the species barrier to infect humans, the highly pathogenic influenza A (H5N1) strain has claimed the lives of more than half of the infected patients. With largely unknown mechanism of lung injury by H5N1 infection, acute respiratory distress syndrome (ARDS) is the major cause of death among the victims. Here we present the fact that H5N1 caused autophagic cell death through suppression of mTOR signaling. Inhibition of autophagy, either by depletion of autophagy gene Beclin1 or by autophagy inhibitor 3-methyladenine (3-MA), significantly reduced H5N1 mediated cell death. We suggest that autophagic cell death may contribute to the development of ARDS in H5N1 influenza patients and inhibition of autophagy could therefore become a novel strategy for the treatment of H5N1 infection.
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Affiliation(s)
- Jianhui Ma
- Department of Physiology and Pathophysiology, State Key Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences and School of Basic Medicine, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing
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1353
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Shin DH, Min HY, El-Naggar AK, Lippman SM, Glisson B, Lee HY. Akt/mTOR counteract the antitumor activities of cixutumumab, an anti-insulin-like growth factor I receptor monoclonal antibody. Mol Cancer Ther 2011; 10:2437-48. [PMID: 21980128 DOI: 10.1158/1535-7163.mct-11-0235] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Recent reports have shown limited anticancer therapeutic efficacy of insulin-like growth factor receptor (IGF-1R)-targeted monoclonal antibodies (mAb), but the resistance mechanisms have not been completely identified. Because cooperation between epidermal growth factor receptor (EGFR) and IGF-IR could cause resistance to inhibitors of individual receptor tyrosine kinases, we investigated the involvement of EGFR signaling in resistance to IGF-1R mAb and the underlying mechanisms of action. Most head and neck squamous cell carcinoma (HNSCC) tissues had coexpression of total and phosphorylated IGF-1R and EGFR at high levels compared with paired adjacent normal tissues. Treatment with cixutumumab (IMC-A12), a fully humanized IgG1 mAb, induced activation of Akt and mTOR, resulting in de novo synthesis of EGFR, Akt1, and survivin proteins and activation of the EGFR pathway in cixutumumab-resistant HNSCC and non-small cell lung cancer (NSCLC) cells. Targeting mTOR and EGFR pathways by treatment with rapamycin and cetuximab (an anti-EGFR mAb), respectively, prevented cixutumumab-induced expression of EGFR, Akt, and survivin and induced synergistic antitumor effects in vitro and in vivo. These data show that resistance to IGF-1R inhibition by mAbs is associated with Akt/mTOR-directed enhanced synthesis of EGFR, Akt1, and survivin. Our findings suggest that Akt/mTOR might be effective targets to overcome the resistance to IGF-1R mAbs in HNSCC and NSCLC.
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MESH Headings
- Animals
- Antibodies, Monoclonal/pharmacology
- Antibodies, Monoclonal/therapeutic use
- Antibodies, Monoclonal, Humanized
- Carcinoma, Non-Small-Cell Lung/drug therapy
- Carcinoma, Non-Small-Cell Lung/genetics
- Carcinoma, Non-Small-Cell Lung/metabolism
- Carcinoma, Squamous Cell/drug therapy
- Carcinoma, Squamous Cell/genetics
- Carcinoma, Squamous Cell/metabolism
- Drug Antagonism
- Drug Resistance, Neoplasm/genetics
- Head and Neck Neoplasms/drug therapy
- Head and Neck Neoplasms/genetics
- Head and Neck Neoplasms/metabolism
- Humans
- Lung Neoplasms/drug therapy
- Lung Neoplasms/genetics
- Lung Neoplasms/metabolism
- Mice
- Mice, Nude
- Proto-Oncogene Proteins c-akt/genetics
- Proto-Oncogene Proteins c-akt/metabolism
- Proto-Oncogene Proteins c-akt/physiology
- Receptor, IGF Type 1/antagonists & inhibitors
- Receptor, IGF Type 1/immunology
- Squamous Cell Carcinoma of Head and Neck
- TOR Serine-Threonine Kinases/genetics
- TOR Serine-Threonine Kinases/metabolism
- TOR Serine-Threonine Kinases/physiology
- Tumor Cells, Cultured
- Xenograft Model Antitumor Assays
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Affiliation(s)
- Dong Hoon Shin
- Department of Thoracic/Head and Neck Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
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1354
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Velazquez-Garcia S, Valle S, Rosa TC, Takane KK, Demirci C, Alvarez-Perez JC, Mellado-Gil JM, Ernst S, Scott DK, Vasavada RC, Alonso LC, Garcia-Ocaña A. Activation of protein kinase C-ζ in pancreatic β-cells in vivo improves glucose tolerance and induces β-cell expansion via mTOR activation. Diabetes 2011; 60:2546-59. [PMID: 21911744 PMCID: PMC3178296 DOI: 10.2337/db10-1783] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
OBJECTIVE PKC-ζ activation is a key signaling event for growth factor-induced β-cell replication in vitro. However, the effect of direct PKC-ζ activation in the β-cell in vivo is unknown. In this study, we examined the effects of PKC-ζ activation in β-cell expansion and function in vivo in mice and the mechanisms associated with these effects. RESEARCH DESIGN AND METHODS We characterized glucose homeostasis and β-cell phenotype of transgenic (TG) mice with constitutive activation of PKC-ζ in the β-cell. We also analyzed the expression and regulation of signaling pathways, G1/S cell cycle molecules, and β-cell functional markers in TG and wild-type mouse islets. RESULTS TG mice displayed increased plasma insulin, improved glucose tolerance, and enhanced insulin secretion with concomitant upregulation of islet insulin and glucokinase expression. In addition, TG mice displayed increased β-cell proliferation, size, and mass compared with wild-type littermates. The increase in β-cell proliferation was associated with upregulation of cyclins D1, D2, D3, and A and downregulation of p21. Phosphorylation of D-cyclins, known to initiate their rapid degradation, was reduced in TG mouse islets. Phosphorylation/inactivation of GSK-3β and phosphorylation/activation of mTOR, critical regulators of D-cyclin expression and β-cell proliferation, were enhanced in TG mouse islets, without changes in Akt phosphorylation status. Rapamycin treatment in vivo eliminated the increases in β-cell proliferation, size, and mass; the upregulation of cyclins Ds and A in TG mice; and the improvement in glucose tolerance-identifying mTOR as a novel downstream mediator of PKC-ζ-induced β-cell replication and expansion in vivo. CONCLUSIONS PKC:-ζ, through mTOR activation, modifies the expression pattern of β-cell cycle molecules leading to increased β-cell replication and mass with a concomitant enhancement in β-cell function. Approaches to enhance PKC-ζ activity may be of value as a therapeutic strategy for the treatment of diabetes.
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Affiliation(s)
- Silvia Velazquez-Garcia
- Department of Medicine, Division of Endocrinology and Metabolism, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Shelley Valle
- Department of Medicine, Division of Endocrinology and Metabolism, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Taylor C. Rosa
- Department of Medicine, Division of Endocrinology and Metabolism, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Karen K. Takane
- Department of Medicine, Division of Endocrinology and Metabolism, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Cem Demirci
- Department of Pediatrics, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Juan C. Alvarez-Perez
- Department of Medicine, Division of Endocrinology and Metabolism, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Jose M. Mellado-Gil
- Department of Medicine, Division of Endocrinology and Metabolism, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Sara Ernst
- Department of Medicine, Division of Endocrinology and Metabolism, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Donald K. Scott
- Department of Medicine, Division of Endocrinology and Metabolism, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Rupangi C. Vasavada
- Department of Medicine, Division of Endocrinology and Metabolism, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Laura C. Alonso
- Department of Medicine, Division of Endocrinology and Metabolism, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Adolfo Garcia-Ocaña
- Department of Medicine, Division of Endocrinology and Metabolism, University of Pittsburgh, Pittsburgh, Pennsylvania
- Corresponding author: Adolfo Garcia-Ocaña,
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1355
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Lemaître V, Dabo AJ, D'Armiento J. Cigarette smoke components induce matrix metalloproteinase-1 in aortic endothelial cells through inhibition of mTOR signaling. Toxicol Sci 2011; 123:542-9. [PMID: 21742783 PMCID: PMC3179676 DOI: 10.1093/toxsci/kfr181] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2011] [Accepted: 06/27/2011] [Indexed: 01/04/2023] Open
Abstract
Smoking is a major risk factor for heart disease, but the molecular effects of cigarette smoke on vascular cells are poorly understood. In this study, we demonstrate that matrix metalloproteinase-1 (MMP-1), a collagenase expressed in atherosclerosis and aneurysms but not in the normal vessel wall, is induced in the aortic endothelium of rabbits exposed to cigarette smoke. In vitro cigarette smoke extract (CSE) and one of its components, acrolein, inhibit the mammalian target of rapamycin (mTOR)/p70S6K pathway in human endothelial cells, and chemical inhibition of this pathway by rapamycin resulted in elevated MMP-1. Moreover, the tissue inhibitor of metalloproteases-3 (TIMP-3), a major regulator of angiogenesis, is significantly downregulated in aortic endothelial cells treated with CSE, acrolein, or rapamycin. These data indicate that inhibition of mTOR by cigarette smoke components is a key event in the modulation of endothelial MMP-1 and TIMP-3 expression. Our study suggests that circulating smoke components, including acrolein, contribute to vascular diseases through enhanced MMP-1 and decreased TIMP-3 secretion in the endothelium, potentially leading to impaired angiogenesis, matrix disruption, and vessel injury.
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Affiliation(s)
| | | | - Jeanine D'Armiento
- Division of Molecular Medicine, Department of Medicine, Columbia University College of Physicians and Surgeons, New York, New York 10032
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1356
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Hutz JE, Manning WA, Province MA, McLeod HL. Genomewide analysis of inherited variation associated with phosphorylation of PI3K/AKT/mTOR signaling proteins. PLoS One 2011; 6:e24873. [PMID: 21949775 PMCID: PMC3176272 DOI: 10.1371/journal.pone.0024873] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2011] [Accepted: 08/19/2011] [Indexed: 02/03/2023] Open
Abstract
While there exists a wealth of information about genetic influences on gene expression, less is known about how inherited variation influences the expression and post-translational modifications of proteins, especially those involved in intracellular signaling. The PI3K/AKT/mTOR signaling pathway contains several such proteins that have been implicated in a number of diseases, including a variety of cancers and some psychiatric disorders. To assess whether the activation of this pathway is influenced by genetic factors, we measured phosphorylated and total levels of three key proteins in the pathway (AKT1, p70S6K, 4E-BP1) by ELISA in 122 lymphoblastoid cell lines from 14 families. Interestingly, the phenotypes with the highest proportion of genetic influence were the ratios of phosphorylated to total protein for two of the pathway members: AKT1 and p70S6K. Genomewide linkage analysis suggested several loci of interest for these phenotypes, including a linkage peak for the AKT1 phenotype that contained the AKT1 gene on chromosome 14. Linkage peaks for the phosphorylated:total protein ratios of AKT1 and p70S6K also overlapped on chromosome 3. We selected and genotyped candidate genes from under the linkage peaks, and several statistically significant associations were found. One polymorphism in HSP90AA1 was associated with the ratio of phosphorylated to total AKT1, and polymorphisms in RAF1 and GRM7 were associated with the ratio of phosphorylated to total p70S6K. These findings, representing the first genomewide search for variants influencing human protein phosphorylation, provide useful information about the PI3K/AKT/mTOR pathway and serve as a valuable proof of concept for studies integrating human genomics and proteomics.
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Affiliation(s)
- Janna E. Hutz
- Institute for Pharmacogenomics and Individualized Therapy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
- Division of Statistical Genomics, Washington University in St. Louis, St. Louis, Missouri, United States of America
| | - W. Aaron Manning
- Institute for Pharmacogenomics and Individualized Therapy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Michael A. Province
- Division of Statistical Genomics, Washington University in St. Louis, St. Louis, Missouri, United States of America
| | - Howard L. McLeod
- Institute for Pharmacogenomics and Individualized Therapy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
- * E-mail:
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1357
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Vazquez-Martin A, Cufí S, Oliveras-Ferraros C, Menendez JA. Raptor, a positive regulatory subunit of mTOR complex 1, is a novel phosphoprotein of the rDNA transcription machinery in nucleoli and chromosomal nucleolus organizer regions (NORs). Cell Cycle 2011; 10:3140-52. [PMID: 21900751 DOI: 10.4161/cc.10.18.17376] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Raptor is the key scaffolding protein that recruits mTOR substrates to rapamycin-sensitive mTOR complex 1 (mTORC1), a molecular integrator of mitogenic and nutrient/energy environmental inputs into protein translation and cell growth. Although Raptor phosphorylation on various sites is pivotal in the regulation of mTORC1 activity, it remains to be elucidated whether site-specific phosphorylation differentially distributes Raptor to unique subcellular compartments. When exploring the spatiotemporal cell cycle dynamics of six different phospho (P)-Raptor isoforms (Thr ( 706) , Ser ( 722) , Ser ( 863) , Ser ( 792) and Ser ( 877) ), a number of remarkable events differentially defined a topological resetting of P-RaptorThr706 on interphasic and mitotic chromosomes. In interphase nuclei, P-Raptor (Thr706) co-localized with fibrillarin, a component of the nucleolar small nuclear ribonucleoprotein particle, as well as with RNA polymerase I, the enzyme that transcribes nucleolar rRNA. Upon Actinomycin D-induced nucleolar segregation and disaggregation, P-RaptorThr706 was excluded from the nucleolus to accumulate at discrete nucleoplasmic bodies. During mitosis, CDK1 inhibition-induced premature assembly of nucleoli relocated fibrillarin to the surrounding regions of chromosomal-associated P-Raptor (Thr706) , suggesting that a subpopulation of mitotic P-Raptor (Thr706) remained targeted at chromosomal loops of rDNA or nuclear organizer regions (NORs). At the end of mitosis and cytokinesis, when reassembly of incipient nucleoli begins upon NORs activation of rDNA transcription, fibrillarin spatially reorganized with P-Raptor (Thr706) to give rise to daughter nucleoli. Treatment with IGF1 exclusively hyperactivated nuclear P-Raptor (Ser706) and concomitantly promoted Ser ( 2481) autophosphorylation of mTOR, which monitors mTORC1-associated catalytic activity. Nucleolar- and NOR-associated P-Raptor (Ser706) may physically link mTORC1 signaling to ever-growing nucleolus plurifunctionality including ribosome biogenesis, cell stress sensor and cell cycle/aging control.
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MESH Headings
- Adaptor Proteins, Signal Transducing/genetics
- Adaptor Proteins, Signal Transducing/metabolism
- Benzimidazoles/pharmacology
- Cell Cycle Proteins/antagonists & inhibitors
- Cell Cycle Proteins/metabolism
- Cell Nucleolus/drug effects
- Cell Nucleolus/genetics
- Cell Nucleolus/metabolism
- Centrosome/metabolism
- Chromosomal Proteins, Non-Histone/genetics
- Chromosomal Proteins, Non-Histone/metabolism
- Chromosomes, Human/genetics
- Chromosomes, Human/metabolism
- Cytokinesis
- DNA, Ribosomal/genetics
- DNA, Ribosomal/metabolism
- Dactinomycin/pharmacology
- Female
- Fluorescent Antibody Technique
- HeLa Cells
- Humans
- Interphase
- Mechanistic Target of Rapamycin Complex 1
- Microscopy, Confocal
- Mitosis
- Multiprotein Complexes
- Nucleolus Organizer Region/genetics
- Nucleolus Organizer Region/metabolism
- Phosphorylation
- Protein Isoforms/genetics
- Protein Isoforms/metabolism
- Protein Serine-Threonine Kinases/antagonists & inhibitors
- Protein Serine-Threonine Kinases/metabolism
- Proteins/genetics
- Proteins/metabolism
- Proto-Oncogene Proteins/antagonists & inhibitors
- Proto-Oncogene Proteins/metabolism
- Regulatory-Associated Protein of mTOR
- TOR Serine-Threonine Kinases/genetics
- TOR Serine-Threonine Kinases/metabolism
- Thiophenes/pharmacology
- Transcription, Genetic
- Transcriptional Activation
- Polo-Like Kinase 1
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Affiliation(s)
- Alejandro Vazquez-Martin
- Unit of Translational Research, Catalan Institute of Oncology-Girona, Girona Biomedical Research Institute, Girona, Spain
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1358
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Xie X, Ghadimi MPH, Young ED, Belousov R, Zhu QS, Liu J, Lopez G, Colombo C, Peng T, Reynoso D, Hornick JL, Lazar AJ, Lev D. Combining EGFR and mTOR blockade for the treatment of epithelioid sarcoma. Clin Cancer Res 2011; 17:5901-12. [PMID: 21821699 PMCID: PMC3176924 DOI: 10.1158/1078-0432.ccr-11-0660] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
PURPOSE Molecular deregulations underlying epithelioid sarcoma (ES) progression are poorly understood yet critically needed to develop new therapies. Epidermal growth factor receptor (EGFR) is overexpressed in ES; using preclinical models, we examined the ES EGFR role and assessed anti-ES EGFR blockade effects, alone and with mTOR inhibition. EXPERIMENTAL DESIGN EGFR and mTOR expression/activation was examined via tissue microarray (n = 27 human ES specimens; immunohistochemistry) and in human ES cell lines (Western blot and quantitative reverse transcriptase PCR). Cell proliferation, survival, migration, and invasion effects of EGFR and mTOR activation treated with erlotinib (anti-EGFR small-molecule inhibitor) alone and combined with rapamycin were assessed in cell culture assays. In vivo growth effects of erlotinib alone or with rapamycin were evaluated using severe combined immunodeficient mouse ES xenograft models. RESULTS EGFR was expressed and activated in ES specimens and cell lines. EGFR activation increased ES cell proliferation, motility, and invasion and induced cyclin D1, matrix metalloproteinase (MMP) 2, and MMP9 expression. EGFR blockade inhibited these processes and caused significant cytostatic ES growth inhibition in vivo. mTOR pathway activation at varying levels was identified in all tissue microarray-evaluable ES tissues; 88% of samples had no or reduced PTEN expression. Similarly, both ES cell lines showed enhanced mTOR activity; VAESBJ cells exhibited constitutive mTOR activation uncoupled from EGFR signaling. Most importantly, combined erlotinib/rapamycin resulted in synergistic anti-ES effects in vitro and induced superior tumor growth inhibition in vivo versus single agent administration. CONCLUSIONS EGFR and mTOR signaling pathways are deregulated in ES. Preclinical ES model-derived insights suggest that combined inhibition of these targets might be beneficial, supporting evaluations in clinical trials.
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Affiliation(s)
- Xianbiao Xie
- Department of Surgical Oncology, Adult Sarcoma Research Center, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
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1359
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Kye MJ, Neveu P, Lee YS, Zhou M, Steen JA, Sahin M, Kosik KS, Silva AJ. NMDA mediated contextual conditioning changes miRNA expression. PLoS One 2011; 6:e24682. [PMID: 21931811 PMCID: PMC3171446 DOI: 10.1371/journal.pone.0024682] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2011] [Accepted: 08/15/2011] [Indexed: 11/18/2022] Open
Abstract
We measured the expression of 187 miRNAs using quantitative real time PCR in the hippocampal CA1 region of contextually conditioned mice and cultured embryonic rat hippocampal neurons after neuronal stimulation with either NMDA or bicuculline. Many of the changes in miRNA expression after these three types of stimulation were similar. Surprisingly, the expression level of half of the 187 measured miRNAs was changed in response to contextual conditioning in an NMDA receptor-dependent manner. Genes that control miRNA biogenesis and components of the RISC also exhibited activity induced expression changes and are likely to contribute to the widespread changes in the miRNA profile. The widespread changes in miRNA expression are consistent with the finding that genes up-regulated by contextual conditioning have longer 3′ UTRs and more predicted binding sites for miRNAs. Among the miRNAs that changed their expression after contextual conditioning, several inhibit inhibitors of the mTOR pathway. These findings point to a role for miRNAs in learning and memory that includes mTOR-dependent modulation of protein synthesis.
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Affiliation(s)
- Min Jeong Kye
- Neuroscience Research Institute, University of California Santa Barbara, Santa Barbara, California, United States of America
- Department of Molecular, Cellular and Developmental Biology, University of California Santa Barbara, Santa Barbara, California, United States of America
- The F.M. Kirby Neurobiology Center, Department of Neurology, Children's Hospital Boston, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Pierre Neveu
- Neuroscience Research Institute, University of California Santa Barbara, Santa Barbara, California, United States of America
- Kavli Institute for Theoretical Physics, University of California Santa Barbara, Santa Barbara, California, United States of America
| | - Yong-Seok Lee
- Departments of Neurobiology, Psychiatry and Psychology, Brain Research Institute, Integrative Center for Learning and Memory, David Geffen School of Medicine at University of California Los Angeles, Los Angeles, California, United States of America
| | - Miou Zhou
- Departments of Neurobiology, Psychiatry and Psychology, Brain Research Institute, Integrative Center for Learning and Memory, David Geffen School of Medicine at University of California Los Angeles, Los Angeles, California, United States of America
| | - Judith A. Steen
- The F.M. Kirby Neurobiology Center, Department of Neurology, Children's Hospital Boston, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Mustafa Sahin
- The F.M. Kirby Neurobiology Center, Department of Neurology, Children's Hospital Boston, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Kenneth S. Kosik
- Neuroscience Research Institute, University of California Santa Barbara, Santa Barbara, California, United States of America
- Department of Molecular, Cellular and Developmental Biology, University of California Santa Barbara, Santa Barbara, California, United States of America
- * E-mail:
| | - Alcino J. Silva
- Departments of Neurobiology, Psychiatry and Psychology, Brain Research Institute, Integrative Center for Learning and Memory, David Geffen School of Medicine at University of California Los Angeles, Los Angeles, California, United States of America
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1360
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Gazzaneo MC, Orellana RA, Suryawan A, Tuckow AP, Kimball SR, Wilson FA, Nguyen HV, Torrazza RM, Fiorotto ML, Davis TA. Differential regulation of protein synthesis and mTOR signaling in skeletal muscle and visceral tissues of neonatal pigs after a meal. Pediatr Res 2011; 70:253-60. [PMID: 21654549 PMCID: PMC3152601 DOI: 10.1203/pdr.0b013e3182276cfa] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Protein synthesis (PS) increases after a meal in neonates, but the time course of the changes in PS in different tissues after a meal is unknown. We aimed to evaluate the changes in tissue PS, mammalian target of rapamycin complex 1 (mTORC1) activation, and proportion of ribosomal protein (rp) mRNAs in polysomes over 4 h after a bolus meal in neonatal pigs (n = 6/group; 5- to 7-d-old). The results show a more sustained increase in PS in glycolytic compared with mixed fiber type muscles and no changes in oxidative muscles. PS increased in liver, jejunum, and pancreas but not in kidney and heart. Feeding did not affect AMP-activated protein kinase or RAS-related GTP binding B activation. Phosphorylation of tuberous sclerosis complex 2, proline-rich Akt substrate of 40 kD, mTOR, eukaryotic initiation factor 4E binding protein, and rp S6 kinase 1 increased in all tissues after feeding. The proportion of mRNAs encoding rp S4 and S8 in liver polysomes increased within 30 min postfeeding. These results suggest that feeding stimulates mTORC1 signaling in muscle and viscera, but mTORC1 activation alone is not sufficient to stimulate PS in all tissues.
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Affiliation(s)
- María C Gazzaneo
- Department of Pediatrics, United States Department of Agriculture/Agriculture Research Service, Children's Nutrition Research Center, Baylor College of Medicine, Houston, Texas 77030, USA
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1361
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Bröer A, Juelich T, Vanslambrouck JM, Tietze N, Solomon PS, Holst J, Bailey CG, Rasko JEJ, Bröer S. Impaired nutrient signaling and body weight control in a Na+ neutral amino acid cotransporter (Slc6a19)-deficient mouse. J Biol Chem 2011; 286:26638-51. [PMID: 21636576 PMCID: PMC3143628 DOI: 10.1074/jbc.m111.241323] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2011] [Revised: 06/01/2011] [Indexed: 01/11/2023] Open
Abstract
Amino acid uptake in the intestine and kidney is mediated by a variety of amino acid transporters. To understand the role of epithelial neutral amino acid uptake in whole body homeostasis, we analyzed mice lacking the apical broad-spectrum neutral (0) amino acid transporter B(0)AT1 (Slc6a19). A general neutral aminoaciduria was observed similar to human Hartnup disorder which is caused by mutations in SLC6A19. Na(+)-dependent uptake of neutral amino acids into the intestine and renal brush-border membrane vesicles was abolished. No compensatory increase of peptide transport or other neutral amino acid transporters was detected. Mice lacking B(0)AT1 showed a reduced body weight. When adapted to a standard 20% protein diet, B(0)AT1-deficient mice lost body weight rapidly on diets containing 6 or 40% protein. Secretion of insulin in response to food ingestion after fasting was blunted. In the intestine, amino acid signaling to the mammalian target of rapamycin (mTOR) pathway was reduced, whereas the GCN2/ATF4 stress response pathway was activated, indicating amino acid deprivation in epithelial cells. The results demonstrate that epithelial amino acid uptake is essential for optimal growth and body weight regulation.
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Affiliation(s)
- Angelika Bröer
- Research School of Biology, Australian National University, Canberra, Australian Capital Territory 0200, Australia.
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1362
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Plano D, Ibáñez E, Calvo A, Palop JA, Sanmartín C. Novel library of selenocompounds as kinase modulators. Molecules 2011; 16:6349-64. [PMID: 21796074 PMCID: PMC6264252 DOI: 10.3390/molecules16086349] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2011] [Revised: 07/20/2011] [Accepted: 07/22/2011] [Indexed: 12/30/2022] Open
Abstract
Although the causes of cancer lie in mutations or epigenic changes at the genetic level, their molecular manifestation is the dysfunction of biochemical pathways at the protein level. The 518 protein kinases encoded by the human genome play a central role in various diseases, a fact that has encouraged extensive investigations on their biological function and three dimensional structures. Selenium (Se) is an important nutritional trace element involved in different physiological functions with antioxidative, antitumoral and chemopreventive properties. The mechanisms of action for selenocompounds as anticancer agents are not fully understood, but kinase modulation seems to be a possible pathway. Various organosulfur compounds have shown antitumoral and kinase inhibition effects but, in many cases, the replacement of sulfur by selenium improves the antitumoral effect of compounds. Although Se atom possesses a larger atomic volume and nucleophilic character than sulfur, Se can also formed interactions with aminoacids of the catalytic centers of proteins. So, we propose a novel chemical library that includes organoselenium compounds as kinase modulators. In this study thirteen selenocompounds have been evaluated at a concentration of 3 or 10 µM in a 24 kinase panel using a Caliper LabChip 3000 Drug Discover Platform. Several receptor (EGFR, IGFR1, FGFR1…) and non-receptor (Abl) kinases have been selected, as well as serine/threonine/lipid kinases (AurA, Akt, CDKs, MAPKs…) implicated in main cancer pathways: cell cycle regulation, signal transduction, angiogenesis regulation among them. The obtained results showed that two compounds presented inhibition values higher than 50% in at least four kinases and seven derivatives selectively inhibited one or two kinases. Furthermore, three compounds selectively activated IGF-1R kinase with values ranging from −98% to −211%. In conclusion, we propose that the replacement of sulfur by selenium seems to be a potential and useful strategy in the search of novel chemical compound libraries against cancer as kinase modulators.
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Affiliation(s)
- Daniel Plano
- Department of Organic and Pharmaceutical Chemistry, University of Navarra, Irunlarrea, 1, Pamplona E-31008, Spain
| | - Elena Ibáñez
- Department of Organic and Pharmaceutical Chemistry, University of Navarra, Irunlarrea, 1, Pamplona E-31008, Spain
| | - Alfonso Calvo
- Oncology Division, Center for Applied Medical Research, CIMA, University of Navarra, Pío XII, 53, Pamplona E-31008, Spain
| | - Juan Antonio Palop
- Department of Organic and Pharmaceutical Chemistry, University of Navarra, Irunlarrea, 1, Pamplona E-31008, Spain
| | - Carmen Sanmartín
- Department of Organic and Pharmaceutical Chemistry, University of Navarra, Irunlarrea, 1, Pamplona E-31008, Spain
- Author to whom correspondence should be addressed;
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1363
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Karlsson E, Waltersson MA, Bostner J, Pérez-Tenorio G, Olsson B, Hallbeck AL, Stål O. High-resolution genomic analysis of the 11q13 amplicon in breast cancers identifies synergy with 8p12 amplification, involving the mTOR targets S6K2 and 4EBP1. Genes Chromosomes Cancer 2011; 50:775-87. [PMID: 21748818 DOI: 10.1002/gcc.20900] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2010] [Accepted: 06/06/2011] [Indexed: 11/07/2022] Open
Abstract
The chromosomal region 11q13 is amplified in 15-20% of breast cancers; an event not only associated with estrogen receptor (ER) expression but also implicated in resistance to endocrine therapy. Coamplifications of the 11q13 and 8p12 regions are common, suggesting synergy between the amplicons. The aim was to identify candidate oncogenes in the 11q13 region based on recurrent amplification patterns and correlations to mRNA expression levels. Furthermore, the 11q13/8p12 coamplification and its prognostic value, was evaluated at the DNA and the mRNA levels. Affymetrix 250K NspI arrays were used for whole-genome screening of DNA copy number changes in 29 breast tumors. To identify amplicon cores at 11q13 and 8p12, genomic identification of significant targets in cancer (GISTIC) was applied. The mRNA expression levels of candidate oncogenes in the amplicons [RAD9A, RPS6KB2 (S6K2), CCND1, FGF19, FGF4, FGF3, PAK1, GAB2 (11q13); EIF4EBP1 (4EBP1), PPAPDC1B, and FGFR1 (8p12)] were evaluated using real-time PCR. Resulting data revealed three main amplification cores at 11q13. ER expression was associated with the central 11q13 amplification core, encompassing CCND1, whereas 8p12 amplification/gene expression correlated to S6K2 in a proximal 11q13 core. Amplification of 8p12 and high expression of 4EBP1 or FGFR1 was associated with a poor outcome in the group. In conclusion, single nucleotide polymorphism arrays have enabled mapping of the 11q13 amplicon in breast tumors with high resolution. A proximal 11q13 core including S6K2 was identified as involved in the coamplification/coexpression with 8p12, suggesting synergy between the mTOR targets S6K2 and 4EBP1 in breast cancer development and progression.
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MESH Headings
- Adaptor Proteins, Signal Transducing/genetics
- Biomarkers, Tumor/genetics
- Breast Neoplasms/diagnosis
- Breast Neoplasms/genetics
- Breast Neoplasms/mortality
- Breast Neoplasms/pathology
- Cell Cycle Proteins
- Chromosome Mapping
- Chromosomes, Human, Pair 11/chemistry
- Chromosomes, Human, Pair 11/genetics
- Chromosomes, Human, Pair 8/chemistry
- Chromosomes, Human, Pair 8/genetics
- Female
- Gene Amplification
- Gene Expression
- Genome, Human
- Genome-Wide Association Study
- Genomics/methods
- Humans
- Oligonucleotide Array Sequence Analysis
- Phosphoproteins/genetics
- Polymorphism, Single Nucleotide
- Prognosis
- Real-Time Polymerase Chain Reaction
- Ribosomal Protein S6 Kinases, 70-kDa/genetics
- Survival Analysis
- TOR Serine-Threonine Kinases/genetics
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Affiliation(s)
- Elin Karlsson
- Department of Clinical and Experimental Medicine, Division of Oncology, Faculty of Health Sciences, Linköping University, Linköping, Sweden.
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1364
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Sebert SP, Dellschaft NS, Chan LLY, Street H, Henry M, Francois C, Sharma V, Fainberg HP, Patel N, Roda J, Keisler D, Budge H, Symonds ME. Maternal nutrient restriction during late gestation and early postnatal growth in sheep differentially reset the control of energy metabolism in the gastric mucosa. Endocrinology 2011; 152:2816-26. [PMID: 21558318 PMCID: PMC3192420 DOI: 10.1210/en.2011-0169] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Fetal growth restriction followed by accelerated postnatal growth contributes to impaired metabolic function in adulthood. The extent to which these outcomes may be mediated centrally within the hypothalamus, as opposed to in the periphery within the digestive tract, remains unknown. In a sheep model, we achieved intrauterine growth restriction experimentally by maternal nutrient restriction (R) that involved a 40% reduction in food intake through late gestation. R offspring were then either reared singly to accelerate postnatal growth (RA) or as twins and compared with controls also reared singly. From weaning, all offspring were maintained indoors until adulthood. A reduced litter size accelerated postnatal growth for only the first month of lactation. Independently from postnatal weight gain and later fat mass, R animals developed insulin resistance as adults. However, restricted accelerated offspring compared with both the control accelerated and restricted restricted offspring ate less and had higher fasting plasma leptin as adults, an adaptation which was accompanied by changes in energy sensing and cell proliferation within the abomasum. Additionally, although fetal restriction down-regulated gene expression of mammalian target of rapamycin and carnitine palmitoyltransferase 1-dependent pathways in the abomasum, RA offspring compensated for this by exhibiting greater activity of AMP-activated kinase-dependent pathways. This study demonstrates a role for perinatal nutrition in the peripheral control of food intake and in energy sensing in the gastric mucosal and emphasizes the importance of diet in early life in regulating energy metabolism during adulthood.
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Affiliation(s)
- S P Sebert
- Academic Child Health, School of Clinical Sciences, University Hospital, University of Nottingham, Nottingham, NG7 2UH United Kingdom
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1365
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Honda M, Takehana K, Sakai A, Tagata Y, Shirasaki T, Nishitani S, Muramatsu T, Yamashita T, Nakamoto Y, Mizukoshi E, Sakai Y, Yamashita T, Nakamura M, Shimakami T, Yi M, Lemon SM, Suzuki T, Wakita T, Kaneko S. Malnutrition impairs interferon signaling through mTOR and FoxO pathways in patients with chronic hepatitis C. Gastroenterology 2011; 141:128-40, 140.e1-2. [PMID: 21458454 DOI: 10.1053/j.gastro.2011.03.051] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/19/2010] [Revised: 02/21/2011] [Accepted: 03/18/2011] [Indexed: 01/22/2023]
Abstract
BACKGROUND & AIMS Patients with advanced chronic hepatitis C (CH-C) often are malnourished, but the effects of malnutrition on interferon (IFN) signaling and response to treatment have not been determined. We assessed the importance of the nutritional state of the liver on IFN signaling and treatment response. METHODS We studied data from 168 patients with CH-C who were treated with the combination of pegylated-IFN and ribavirin. Plasma concentrations of amino acids were measured by mass spectrometry. Liver gene expression profiles were obtained from 91 patients. Huh-7 cells were used to evaluate the IFN signaling pathway, mammalian target of rapamycin complex 1 (mTORC1), and forkhead box O (FoxO). Antiviral signaling induced by branched-chain amino acids (BCAAs) was determined using the in vitro hepatitis C virus replication system. RESULTS Multivariate logistic regression analysis showed that Fischer's ratio was associated significantly with nonresponders, independent of interleukin-28B polymorphisms or the histologic stage of the liver. Fischer's ratio was correlated inversely with the expression of BCAA transaminase 1, and was affected by hepatic mTORC1 signaling. IFN stimulation was impaired substantially in Huh-7 cells grown in medium that was low in amino acid concentration, through repressed mTORC1 signaling, and increased Socs3 expression, which was regulated by Foxo3a. BCAA could restore impaired IFN signaling and inhibit hepatitis C virus replication under conditions of malnutrition. CONCLUSIONS Malnutrition impaired IFN signaling by inhibiting mTORC1 and activating Socs3 signaling through Foxo3a. Increasing BCAAs to up-regulate IFN signaling might be used as a new therapeutic approach for patients with advanced CH-C.
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Affiliation(s)
- Masao Honda
- Department of Gastroenterology, Kanazawa University Graduate School of Medicine, Kanazawa, Japan
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1366
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Rapa I, Saggiorato E, Giachino D, Palestini N, Orlandi F, Papotti M, Volante M. Mammalian target of rapamycin pathway activation is associated to RET mutation status in medullary thyroid carcinoma. J Clin Endocrinol Metab 2011; 96:2146-53. [PMID: 21543427 DOI: 10.1210/jc.2010-2655] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
CONTEXT The genetic pathways involved in medullary thyroid carcinomas (MTC), except for RET mutations, are largely unknown, as is the detailed mapping of proteins activated as a consequence of RET tyrosine kinase phosphorylation. OBJECTIVE The present study was designed to screen for the presence of mutations in other genes downstream to RET activation and to detect the activation patterns of a panel of intracellular regulators of cell growth. DESIGN Forty-nine cases of MTC were analyzed for mutations in RET, BRAF, N-, H-, and K-RAS, and phosphatidylinositol-3 (PI3) kinase genes. Immunohistochemical analysis was performed using antibodies against several intracellular transducers. The effect of mammalian target of rapamycin (mTOR) inhibition was assessed in vitro onto TT cells by means of methyl thiazolyl tetrazolium and Western blot assays. RESULTS BRAF, K-, H-, and N-RAS, and PI3 kinase mutations were absent in all cases examined. Germline RET mutations were detected in 20% of cases overall, whereas somatic RET mutations represented 53% of sporadic tumors. RET mutational status was associated to age, presence of multifocal tumors, and nodal status, but not disease outcome. Protein expression of markers investigated was highly heterogeneous, with a strong association between phospho-mTOR, phospho-AKT, and phospho-p70S6K, positively correlated to the presence of germline RET mutations. Moreover, selective mTOR inhibition affected cell proliferation of RET-mutant TT cells. CONCLUSIONS Taken together, our findings indicate that mTOR intracellular signaling pathway is functionally activated in MTC with a preferential expression in cases with germline RET mutations; genes downstream to RET tyrosine kinase such as BRAF, RAS isoforms, and PI3 kinase are not mutated in MTC.
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Affiliation(s)
- Ida Rapa
- Department of Clinical and Biological Sciences, University of Turin, San Luigi Hospital, 10043 Orbassano, Turin, Italy
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1367
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Cheung LWT, Hennessy BT, Li J, Yu S, Myers AP, Djordjevic B, Lu Y, Stemke-Hale K, Dyer MD, Zhang F, Ju Z, Cantley LC, Scherer SE, Liang H, Lu KH, Broaddus RR, Mills GB. High frequency of PIK3R1 and PIK3R2 mutations in endometrial cancer elucidates a novel mechanism for regulation of PTEN protein stability. Cancer Discov 2011; 1:170-85. [PMID: 21984976 DOI: 10.1158/2159-8290.cd-11-0039] [Citation(s) in RCA: 350] [Impact Index Per Article: 26.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
We demonstrate that phosphatidylinositol 3-kinase (PI3K) pathway aberrations occur in >80% of endometrioid endometrial cancers, with coordinate mutations of multiple PI3K pathway members being more common than predicted by chance. PIK3R1 (p85α) mutations occur at a higher rate in endometrial cancer than in any other tumor lineage, and PIK3R2 (p85β), not previously demonstrated to be a cancer gene, is also frequently mutated. The dominant activation event in the PI3K pathway appears to be PTEN protein loss. However, in tumors with retained PTEN protein, PI3K pathway mutations phenocopy PTEN loss, resulting in pathway activation. KRAS mutations are common in endometrioid tumors activating independent events from PI3K pathway aberrations. Multiple PIK3R1 and PIK3R2 mutations demonstrate gain of function, including disruption of a novel mechanism of pathway regulation wherein p85α dimers bind and stabilize PTEN. Taken together, the PI3K pathway represents a critical driver of endometrial cancer pathogenesis and a novel therapeutic target.
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Affiliation(s)
- Lydia W T Cheung
- Department of Systems Biology, University of Texas MD Anderson Cancer Center, Houston, TX 77054-1942.
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1368
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Abstract
The mammalian target of rapamycin (mTOR) is an intracellular serine/threonine kinase that exists as a downstream component of numerous signaling pathways. The activation of mTOR results in the production of proteins involved in cell metabolism, growth, proliferation, and angiogenesis. Aberrant activation of mTOR signaling has been identified in a number of cancers, and targeted inhibition of mTOR has been successful in achieving tumor responses, prolonging progression-free survival, and increasing overall survival in various oncologic patient populations. In particular, persistent activation of mTOR signaling has been identified in cell lines and patient samples with leukemias, Hodgkin's lymphoma (HL), non-Hodgkin's lymphoma (NHL), multiple myeloma (MM), and Waldenström's macroglobulinemia (WM). In vitro and preclinical studies using agents that inhibit mTOR signaling have demonstrated cytostatic and cytotoxic effects in these hematologic malignancies, suggesting that mTOR is a rational target for therapy in these disease states. In addition, the combination of mTOR inhibitors with traditional therapies may help to overcome the development of resistance and may improve response rates over those seen with established regimens through synergistic or additive effects. Inhibitors of mTOR signaling currently are being investigated in clinical trials of hematologic malignancies as single agents and as components of combination regimens. Thus far, promising results have been seen with the application of mTOR inhibitors as single agents in patients with relapsed or refractory leukemia, HL, NHL, MM, and WM.
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Affiliation(s)
- Anas Younes
- Department of Lymphoma/Myeloma, M.D. Anderson Cancer Center, Houston, Texas 77030, USA.
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1369
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Xiang T, Jia Y, Sherris D, Li S, Wang H, Lu D, Yang Q. Targeting the Akt/mTOR pathway in Brca1-deficient cancers. Oncogene 2011; 30:2443-50. [PMID: 21242970 PMCID: PMC3107712 DOI: 10.1038/onc.2010.603] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2010] [Revised: 11/23/2010] [Accepted: 11/23/2010] [Indexed: 02/07/2023]
Abstract
The breast cancer susceptibility gene 1 (Brca1) has a key role in both hereditary and sporadic mammary tumorigenesis. However, the reasons why Brca1-deficiency leads to the development of cancer are not clearly understood. Activation of Akt kinase is one of the most common molecular alterations associated with human malignancy. Increased Akt kinase activity has been reported in most breast cancers. We previously found that downregulation of Brca1 expression or mutations of the Brca1 gene activate the Akt oncogenic pathway. To further investigate the role of Brca1/Akt in tumorigenesis, we analyzed Brca1/Akt expression in human breast cancer samples and found that reduced expression of Brca1 was highly correlated with increased phosphorylation of Akt. Consistent with the clinical data, knockdown of Akt1 by short-hairpin RNA inhibited cellular proliferation of Brca1 mutant cells. Importantly, depletion of Akt1 significantly reduced tumor formation induced by Brca1-deficiency in mice. The third generation inhibitor of mammalian target of rapamycin (mTOR), Palomid 529, significantly suppressed Brca1-deficient tumor growth in mice through inhibition of both Akt and mTOR signaling. Our results indicate that activation of Akt is involved in Brca1-deficiency mediated tumorigenesis and that the mTOR pathway can be used as a novel target for treatment of Brca1-deficient cancers.
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MESH Headings
- Animals
- BRCA1 Protein/deficiency
- BRCA1 Protein/genetics
- Benzopyrans/pharmacology
- Blotting, Western
- Breast Neoplasms/genetics
- Breast Neoplasms/metabolism
- Breast Neoplasms/pathology
- Cell Line, Tumor
- Cells, Cultured
- Embryo, Mammalian/cytology
- Female
- Fibroblasts/metabolism
- Humans
- Immunohistochemistry
- Mammary Neoplasms, Experimental/drug therapy
- Mammary Neoplasms, Experimental/genetics
- Mammary Neoplasms, Experimental/pathology
- Mice
- Mice, Inbred NOD
- Mice, Knockout
- Mice, SCID
- Middle Aged
- Mutation
- Proto-Oncogene Proteins c-akt/genetics
- Proto-Oncogene Proteins c-akt/metabolism
- RNA Interference
- Signal Transduction
- TOR Serine-Threonine Kinases/genetics
- TOR Serine-Threonine Kinases/metabolism
- Tumor Burden/drug effects
- Xenograft Model Antitumor Assays
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Affiliation(s)
- T Xiang
- Department of Radiation Oncology, Washington University School of Medicine, St Louis, MO, USA
| | - Y Jia
- Department of Radiation Oncology, Washington University School of Medicine, St Louis, MO, USA
| | - D Sherris
- Paloma Pharmaceuticals, Jamaica Plain, MA, USA
| | - S Li
- Department of Medicine and Siteman Cancer Center, Washington University School of Medicine, St Louis, MO, USA
| | - H Wang
- Department of Pathology and Laboratory Medicine, Cedars-Sinai Medical Center, St Louis, MO, USA
| | - D Lu
- Department of Pathology and Immunology, Washington University School of Medicine, St Louis, MO, USA
| | - Q Yang
- Department of Radiation Oncology, Washington University School of Medicine, St Louis, MO, USA
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1370
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Liu MY, Hou GQ, Zhang Y, Bei WJ, Yan AH. [Effects of mTOR siRNA on mTOR/p70S6K signaling pathway in esophageal squamous cell carcinoma cells and the growth of transplanted tumor in nude mice]. Zhonghua Zhong Liu Za Zhi 2011; 33:334-339. [PMID: 21875460] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
OBJECTIVE To investigate the effects of mTOR siRNA on mTOR-p70S6K signaling pathway in esophageal squamous cell carcinoma (ESCC) cells in vitro,and growth and apoptosis in transplanted tumor in nude mice. METHODS mTOR siRNA was transfected into ESCC cell line EC9706 cells. The expressions of factors of the mTOR/p70S6K signaling pathway were detected by RT-PCR and Western blot. DNA contents and cell apoptosis were determined by flow cytometry, and cell proliferation was measured by CCK-8 assay. The effects of mTOR siRNA on the transplanted tumor growth were assessed in nude mice. RESULTS The levels of mTOR and p-p70S6K were significantly decreased (P < 0.05) while the level of p70S6K was increased (P < 0.05) in the cells transfected with mTOR siRNA, compared with that in untransfected cells and cells transfected with control siRNA. After being interfered by mTOR siRNA, the number of apoptotic cells was increased, cell proliferation became slower and cell cycle was arrested in G(1) phase compared with that in control cells. Also, mTOR siRNA inhibited the growth of transplanted tumor in vivo. CONCLUSIONS mTOR siRNA can effectively interfere in mTOR-p70S6K signaling pathway, induce cell apoptosis and inhibit cell proliferation and tumor growth, suggesting that mTOR-p70S6K signaling pathway plays an important role in the carcinogenesis and development of esophageal squamous cell carcinoma.
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Affiliation(s)
- Ming-yue Liu
- Department of Oncology, People's Hospital of Henan Province, Zhengzhou 450003, China
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1371
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Parthasarathy R, Palli SR. Molecular analysis of nutritional and hormonal regulation of female reproduction in the red flour beetle, Tribolium castaneum. Insect Biochem Mol Biol 2011; 41:294-305. [PMID: 21288489 PMCID: PMC3066291 DOI: 10.1016/j.ibmb.2011.01.006] [Citation(s) in RCA: 93] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2010] [Revised: 01/17/2011] [Accepted: 01/20/2011] [Indexed: 05/24/2023]
Abstract
Female reproduction includes maturation of oocytes and the synthesis of yolk proteins (vitellogenin, Vg) in the fat body and their deposition into the oocytes. Our recent studies showed that juvenile hormone (JH) regulates Vg synthesis and 20-hydroxyecdysone (20E) regulates oocyte maturation in the red flour beetle (Tribolium castaneum). Here, we report on the role of nutritional signaling on vitellogenesis and oogenesis. Comparison of gene expression between fed and starved beetles by microarray analysis showed the up-regulation of genes involved in energy homeostasis and down-regulation of genes involved in egg production in the starved beetles. The RNA interference (RNAi) aided knock-down in the expression of genes involved in insulin and TOR signaling pathways showed that both these signaling pathways play key roles in Vg synthesis and oocyte maturation. Starvation of female beetles resulted in a block in Vg synthesis but not in the progression of primary oocyte development to the resting stage. Feeding after starvation induced Vg synthesis and the progression of primary oocytes from the resting stage to the mature stage. However, in the beetles where JH or 20E synthesis or action was blocked by RNAi, both Vg synthesis and oocyte maturation were affected suggesting that both these hormones (JH and 20E) and nutritional signaling and their cross-talk regulate vitellogenesis and oogenesis.
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Affiliation(s)
| | - Subba R. Palli
- Corresponding Author: Phone: 859 257 4962, Fax: 859 323 1120,
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1372
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Galan-Moya EM, Le Guelte A, Fernandes EL, Thirant C, Dwyer J, Bidere N, Couraud PO, Scott MGH, Junier MP, Chneiweiss H, Gavard J. Secreted factors from brain endothelial cells maintain glioblastoma stem-like cell expansion through the mTOR pathway. EMBO Rep 2011; 12:470-6. [PMID: 21460795 PMCID: PMC3090013 DOI: 10.1038/embor.2011.39] [Citation(s) in RCA: 104] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2010] [Revised: 02/11/2011] [Accepted: 02/15/2011] [Indexed: 01/15/2023] Open
Abstract
Glioma stem-cells are associated with the brain vasculature. However, the way in which this vascular niche regulates stem-cell renewal and fate remains unclear. Here, we show that factors emanating from brain endothelial cells positively control the expansion of long-term glioblastoma stem-like cells. We find that both pharmacological inhibition of and RNA interference with the mammalian target of rapamycin (mTOR) pathway reduce their spheroid growth. Conversely, the endothelial secretome is sufficient to promote this mTOR-dependent survival. Thus, interfering with endothelial signals might present opportunities to identify treatments that selectively target malignant stem-cell niches.
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Affiliation(s)
- Eva Maria Galan-Moya
- INSERM U1016, Institut Cochin, 22 rue Mechain, 75014 Paris
- CNRS, UMR 8104, 22 rue Mechain, 75014 Paris
- Université Paris Descartes, 12 rue de l'Ecole de Medecine, 75006 Paris
| | - Armelle Le Guelte
- INSERM U1016, Institut Cochin, 22 rue Mechain, 75014 Paris
- CNRS, UMR 8104, 22 rue Mechain, 75014 Paris
- Université Paris Descartes, 12 rue de l'Ecole de Medecine, 75006 Paris
| | - Evelyne Lima Fernandes
- INSERM U1016, Institut Cochin, 22 rue Mechain, 75014 Paris
- CNRS, UMR 8104, 22 rue Mechain, 75014 Paris
- Université Paris Descartes, 12 rue de l'Ecole de Medecine, 75006 Paris
| | - Cécile Thirant
- Université Paris Descartes, 12 rue de l'Ecole de Medecine, 75006 Paris
- INSERM UMR 894, 2 ter rue d'Alesia, 75014 Paris, France
| | - Julie Dwyer
- INSERM U1016, Institut Cochin, 22 rue Mechain, 75014 Paris
- CNRS, UMR 8104, 22 rue Mechain, 75014 Paris
- Université Paris Descartes, 12 rue de l'Ecole de Medecine, 75006 Paris
| | - Nicolas Bidere
- INSERM U1014, 14 avenue Paul Vaillant Couturier, 94800, Villejuif France
| | - Pierre-Olivier Couraud
- INSERM U1016, Institut Cochin, 22 rue Mechain, 75014 Paris
- CNRS, UMR 8104, 22 rue Mechain, 75014 Paris
- Université Paris Descartes, 12 rue de l'Ecole de Medecine, 75006 Paris
| | - Mark G H Scott
- INSERM U1016, Institut Cochin, 22 rue Mechain, 75014 Paris
- CNRS, UMR 8104, 22 rue Mechain, 75014 Paris
- Université Paris Descartes, 12 rue de l'Ecole de Medecine, 75006 Paris
| | - Marie-Pierre Junier
- Université Paris Descartes, 12 rue de l'Ecole de Medecine, 75006 Paris
- INSERM UMR 894, 2 ter rue d'Alesia, 75014 Paris, France
| | - Hervé Chneiweiss
- Université Paris Descartes, 12 rue de l'Ecole de Medecine, 75006 Paris
- INSERM UMR 894, 2 ter rue d'Alesia, 75014 Paris, France
| | - Julie Gavard
- INSERM U1016, Institut Cochin, 22 rue Mechain, 75014 Paris
- CNRS, UMR 8104, 22 rue Mechain, 75014 Paris
- Université Paris Descartes, 12 rue de l'Ecole de Medecine, 75006 Paris
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1373
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Abstract
Head and neck squamous cell carcinoma (HNSCC), a significant cause of cancer deaths worldwide, has multiple stepwise malignant evolutions. Mammalian target of rapamycin (mTOR) plays a critical role in tumor development, invasion, metastasis and angiogenesis that impact local recurrence and survival. mTOR can also act as a biomarker for personalized adjuvant therapy. In in vivo and in vitro studies, mTOR inhibitor suppresses tumor growth and sensitizes HNSCC to radiation, cytotoxic agents and epidermoid growth factor receptor inhibitors. We have reviewed the pathogenesis of HNSCC, mTOR pathway, mTOR inhibitor and the role of mTOR in HNSCC.
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Affiliation(s)
- Yu-Min Liao
- Division of Hematology and Oncology, Department of Internal Medicine, China Medical University Hospital, Taichung, 404, Taiwan
| | - Charles Kim
- Department of Molecular Pharmacology, Beckman Research Institute, City of Hope Comprehensive Cancer, Duarte, CA 91010, USA
| | - Yun Yen
- Department of Molecular Pharmacology, Beckman Research Institute, City of Hope Comprehensive Cancer, Duarte, CA 91010, USA
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1374
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El Wakil A, Doghman M, Latre De Late P, Zambetti GP, Figueiredo BC, Lalli E. Genetics and genomics of childhood adrenocortical tumors. Mol Cell Endocrinol 2011; 336:169-73. [PMID: 21094206 DOI: 10.1016/j.mce.2010.11.008] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/23/2010] [Revised: 11/10/2010] [Accepted: 11/11/2010] [Indexed: 12/18/2022]
Abstract
Adrenocortical tumors in children are usually diagnosed because of signs of virilization and their prognosis is poor. They possess several distinct pathological features compared to adrenocortical tumors in adults and have an exceptional prevalence in southern Brazil, where they are nearly invariably linked to the presence of a germline specific TP53 (R337H) mutation. Other important factors in childhood adrenocortical tumor pathogenesis are overexpression of the Steroidogenic Factor-1 transcription factor and imprinting defects in the 11p15 genomic region, causing overexpression of Insulin-like Growth Factor-2. Genomic studies have revealed the prognostic relevance of the expression of some Major Histocompatibility Complex genes and the deregulation of the Insulin-like Growth Factor/mammalian Target Of Rapamycin pathway by microRNAs in these tumors. Our hope is that these findings will constitute the basis for the development of novel therapies that will be more active against these tumors and less toxic for the patients.
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Affiliation(s)
- Abeer El Wakil
- Institut de Pharmacologie Moléculaire et Cellulaire, CNRS UMR 6097, France
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1375
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Elgendy M, Sheridan C, Brumatti G, Martin SJ. Oncogenic Ras-induced expression of Noxa and Beclin-1 promotes autophagic cell death and limits clonogenic survival. Mol Cell 2011; 42:23-35. [PMID: 21353614 DOI: 10.1016/j.molcel.2011.02.009] [Citation(s) in RCA: 329] [Impact Index Per Article: 25.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2010] [Revised: 12/14/2010] [Accepted: 02/02/2011] [Indexed: 12/17/2022]
Abstract
Deregulated oncogenes such as MYC and RAS are typically insufficient to transform cells on their own due to the activation of pathways that restrain proliferation. Previous studies have shown that oncogenic H-Ras can induce proliferative arrest or senescence, depending on the cellular context. Here, we show that deregulated H-Ras activity can also lead to caspase-independent cell death with features of autophagy. Ras-induced autophagy was associated with upregulation of the BH3-only protein Noxa as well as the autophagy regulator Beclin-1. Silencing of Noxa or Beclin-1 expression reduced Ras-induced autophagy and increased clonogenic survival. Ras-induced cell death was also inhibited by coexpression of Bcl-2 family members that inhibit Beclin-1 function. Ras-induced autophagy was associated with Noxa-mediated displacement of the Bcl-2 family member, Mcl-1, from Beclin-1. Thus, Ras-induced expression of Noxa and Beclin-1 promotes autophagic cell death, which represents a mechanism to limit the oncogenic potential of deregulated Ras signals.
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Affiliation(s)
- Mohamed Elgendy
- Molecular Cell Biology Laboratory, Department of Genetics, The Smurfit Institute, Trinity College, Dublin 2, Ireland
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1376
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Caccamo A, Maldonado MA, Majumder S, Medina DX, Holbein W, Magrí A, Oddo S. Naturally secreted amyloid-beta increases mammalian target of rapamycin (mTOR) activity via a PRAS40-mediated mechanism. J Biol Chem 2011; 286:8924-32. [PMID: 21266573 PMCID: PMC3058958 DOI: 10.1074/jbc.m110.180638] [Citation(s) in RCA: 128] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2010] [Revised: 01/17/2011] [Indexed: 12/31/2022] Open
Abstract
Reducing the mammalian target of rapamycin (mTOR) activity increases lifespan and health span in a variety of organisms. Alterations in protein homeostasis and mTOR activity and signaling have been reported in several neurodegenerative disorders, including Alzheimer disease (AD); however, the causes of such deregulations remain elusive. Here, we show that mTOR activity and signaling are increased in cell lines stably transfected with mutant amyloid precursor protein (APP) and in brains of 3xTg-AD mice, an animal model of AD. In addition, we show that in the 3xTg-AD mice, mTOR activity can be reduced to wild type levels by genetically preventing Aβ accumulation. Similarly, intrahippocampal injections of an anti-Aβ antibody reduced Aβ levels and normalized mTOR activity, indicating that high Aβ levels are necessary for mTOR hyperactivity in 3xTg-AD mice. We also show that the intrahippocampal injection of naturally secreted Aβ is sufficient to increase mTOR signaling in the brains of wild type mice. The mechanism behind the Aβ-induced mTOR hyperactivity is mediated by the proline-rich Akt substrate 40 (PRAS40) as we show that the activation of PRAS40 plays a key role in the Aβ-induced mTOR hyperactivity. Taken together, our data show that Aβ accumulation, which has been suggested to be the culprit of AD pathogenesis, causes mTOR hyperactivity by regulating PRAS40 phosphorylation. These data further indicate that the mTOR pathway is one of the pathways by which Aβ exerts its toxicity and further support the idea that reducing mTOR signaling in AD may be a valid therapeutic approach.
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Affiliation(s)
- Antonella Caccamo
- From the Department of Physiology and
- the Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center, San Antonio, Texas 78229-3900
| | - Monica A. Maldonado
- From the Department of Physiology and
- the Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center, San Antonio, Texas 78229-3900
| | - Smita Majumder
- From the Department of Physiology and
- the Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center, San Antonio, Texas 78229-3900
| | - David X. Medina
- From the Department of Physiology and
- the Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center, San Antonio, Texas 78229-3900
| | | | - Andrea Magrí
- From the Department of Physiology and
- the Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center, San Antonio, Texas 78229-3900
| | - Salvatore Oddo
- From the Department of Physiology and
- the Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center, San Antonio, Texas 78229-3900
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1377
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Rosario FJ, Jansson N, Kanai Y, Prasad PD, Powell TL, Jansson T. Maternal protein restriction in the rat inhibits placental insulin, mTOR, and STAT3 signaling and down-regulates placental amino acid transporters. Endocrinology 2011; 152:1119-29. [PMID: 21285325 PMCID: PMC3858644 DOI: 10.1210/en.2010-1153] [Citation(s) in RCA: 133] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The mechanisms underlying reduced fetal growth in response to maternal protein restriction are not well established. Maternal levels of insulin, IGF-I, and leptin are decreased in rats fed a low protein (LP) diet. Because these hormones stimulate placental amino acid transporters in vitro, we hypothesized that maternal protein restriction inhibits placental leptin, insulin/IGF-I, and mammalian target of rapamycin signaling and down-regulates the expression and activity of placental amino acid transporters. Pregnant rats were fed either an isocaloric low protein (LP, 4% protein) or control diet (18% protein) and studied at gestational day (GD)15, GD19, or GD21 (term 23). At GD19 and GD21, placental expression of phosphorylated eukaryotic initiation factor 4E binding protein 1 (Thr-36/46 or Thr-70) and phosphorylated S6 ribosomal protein (Ser-235/236) was decreased in the LP group. In addition, placental expression of phosphorylated S6 kinase 1 (Thr-389), phosphorylated Akt (Thr-308), and phosphorylated signal transducer and activator of transcription 3 (Tyr-705) was reduced at GD21. In microvillous plasma membranes (MVM) isolated from placentas of LP animals, protein expression of the sodium-coupled neutral amino acid transporter (SNAT)2 and the large neutral amino acid transporters 1 and 2 was reduced at GD19 and GD21. MVM SNAT1 protein expression was reduced at GD21 in LP rats. SNAT4 and 4F2 heavy chain expression in MVM was unaltered. System A and L amino acid transporter activity was decreased in MVM from LP animals at GD19 and GD21. In conclusion, maternal protein restriction inhibits placental insulin, mammalian target of rapamycin signaling, and signal transducer and activator of transcription 3 signaling, which is associated with a down-regulation of placental amino acid transporters. We speculate that maternal endocrine and metabolic control of placental nutrient transport reduces fetal growth in response to protein restriction.
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Affiliation(s)
- Fredrick J Rosario
- Center for Pregnancy and Newborn Research, Department of Obstetrics and Gynecology, University of Texas Health Science Center San Antonio, Mail Code 7836, 7703 Floyd Curl Drive, San Antonio, Texas 78229-3900, USA
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1378
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Howell JJ, Manning BD. mTOR couples cellular nutrient sensing to organismal metabolic homeostasis. Trends Endocrinol Metab 2011; 22:94-102. [PMID: 21269838 PMCID: PMC3744367 DOI: 10.1016/j.tem.2010.12.003] [Citation(s) in RCA: 246] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/19/2010] [Revised: 12/21/2010] [Accepted: 12/29/2010] [Indexed: 02/08/2023]
Abstract
The mammalian target of rapamycin complex 1 (mTORC1) has the ability to sense a variety of essential nutrients and respond by altering cellular metabolic processes. Hence, this protein kinase complex is poised to influence adaptive changes to nutrient fluctuations toward the maintenance of whole-body metabolic homeostasis. Defects in mTORC1 regulation, arising from either physiological or genetic conditions, are believed to contribute to the metabolic dysfunction underlying a variety of human diseases, including type 2 diabetes. We are just now beginning to gain insights into the complex tissue-specific functions of mTORC1. In this review, we detail the current knowledge of the physiological functions of mTORC1 in controlling systemic metabolism, with a focus on advances obtained through genetic mouse models.
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Affiliation(s)
| | - Brendan D. Manning
- Correspondence to: 665 Huntington Ave., SPH2-117, Boston, MA 02115, Phone: 617 432-5614, Fax: 617 432-5236,
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1379
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Campa D, Hüsing A, Stein A, Dostal L, Boeing H, Pischon T, Tjønneland A, Roswall N, Overvad K, Østergaard JN, Rodríguez L, Sala N, Sánchez MJ, Larrañaga N, Huerta JM, Barricarte A, Khaw KT, Wareham N, Travis RC, Allen NE, Lagiou P, Trichopoulou A, Trichopoulos D, Palli D, Sieri S, Tumino R, Sacerdote C, van Kranen H, Bueno-de-Mesquita HB, Hallmans G, Johansson M, Romieu I, Jenab M, Cox DG, Siddiq A, Riboli E, Canzian F, Kaaks R. Genetic variability of the mTOR pathway and prostate cancer risk in the European Prospective Investigation on Cancer (EPIC). PLoS One 2011; 6:e16914. [PMID: 21373201 PMCID: PMC3044148 DOI: 10.1371/journal.pone.0016914] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2010] [Accepted: 01/01/2011] [Indexed: 01/12/2023] Open
Abstract
The mTOR (mammalian target of rapamycin) signal transduction pathway integrates various signals, regulating ribosome biogenesis and protein synthesis as a function of available energy and amino acids, and assuring an appropriate coupling of cellular proliferation with increases in cell size. In addition, recent evidence has pointed to an interplay between the mTOR and p53 pathways. We investigated the genetic variability of 67 key genes in the mTOR pathway and in genes of the p53 pathway which interact with mTOR. We tested the association of 1,084 tagging SNPs with prostate cancer risk in a study of 815 prostate cancer cases and 1,266 controls nested within the European Prospective Investigation into Cancer and Nutrition (EPIC). We chose the SNPs (n = 11) with the strongest association with risk (p<0.01) and sought to replicate their association in an additional series of 838 prostate cancer cases and 943 controls from EPIC. In the joint analysis of first and second phase two SNPs of the PRKCI gene showed an association with risk of prostate cancer (ORallele = 0.85, 95% CI 0.78–0.94, p = 1.3×10−3 for rs546950 and ORallele = 0.84, 95% CI 0.76–0.93, p = 5.6×10−4 for rs4955720). We confirmed this in a meta-analysis using as replication set the data from the second phase of our study jointly with the first phase of the Cancer Genetic Markers of Susceptibility (CGEMS) project. In conclusion, we found an association with prostate cancer risk for two SNPs belonging to PRKCI, a gene which is frequently overexpressed in various neoplasms, including prostate cancer.
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Affiliation(s)
- Daniele Campa
- German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Anika Hüsing
- German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Angelika Stein
- German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Lucie Dostal
- German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Heiner Boeing
- Department of Epidemiology, Deutsches Institut für Ernährungsforschung, Potsdam-Rehbrücke, Germany
| | - Tobias Pischon
- Department of Epidemiology, Deutsches Institut für Ernährungsforschung, Potsdam-Rehbrücke, Germany
| | - Anne Tjønneland
- The Danish Cancer Society, Institute of Cancer Epidemiology, Copenhagen, Denmark
| | - Nina Roswall
- The Danish Cancer Society, Institute of Cancer Epidemiology, Copenhagen, Denmark
| | - Kim Overvad
- Department of Cardiology, Center for Cardiovascular Research, Aalborg Hospital, Aarhus University Hospital, Aalborg, Denmark
- Department of Epidemiology, School of Public Health, Aarhus University, Denmark
| | - Jane Nautrup Østergaard
- Department of Cardiology, Center for Cardiovascular Research, Aalborg Hospital, Aarhus University Hospital, Aalborg, Denmark
- Department of Epidemiology, School of Public Health, Aarhus University, Denmark
| | - Laudina Rodríguez
- Public Health and Participation Directorate, Health and Health Care Services Council, Asturias, Spain
| | - Núria Sala
- Catalan Institute of Oncology (ICO) - IDIBELL, Barcelona, Spain
| | - Maria-José Sánchez
- Andalusian School of Public Health, Granada, Spain
- Consortium for Biomedical Research in Epidemiology and Public Health (CIBERESP), Madrid, Spain
| | - Nerea Larrañaga
- Consortium for Biomedical Research in Epidemiology and Public Health (CIBERESP), Madrid, Spain
- Public Health Department of Gipuzkoa, Basque Government, Gipuzkoa, Spain
| | - José María Huerta
- Consortium for Biomedical Research in Epidemiology and Public Health (CIBERESP), Madrid, Spain
- Department of Epidemiology, Murcia Regional Health Authority, Murcia, Spain
| | - Aurelio Barricarte
- Consortium for Biomedical Research in Epidemiology and Public Health (CIBERESP), Madrid, Spain
- Navarre Public Health Institute, Pamplona, Spain
| | - Kay-Tee Khaw
- University of Cambridge School of Clinical Medicine, Cambridge, United Kingdom
| | | | - Ruth C. Travis
- Cancer Epidemiology Unit, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, United Kingdom
| | - Naomi E. Allen
- Cancer Epidemiology Unit, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, United Kingdom
| | - Pagona Lagiou
- WHO Collaborating Center for Food and Nutrition Policies, Department of Hygiene, Epidemiology and Medical Statistics, University of Athens Medical School, Athens, Greece
- Department of Epidemiology, Harvard School of Public Health, Boston MA, USA
| | - Antonia Trichopoulou
- WHO Collaborating Center for Food and Nutrition Policies, Department of Hygiene, Epidemiology and Medical Statistics, University of Athens Medical School, Athens, Greece
- Hellenic Health Foundation, Athens, Greece
| | - Dimitrios Trichopoulos
- Department of Epidemiology, Harvard School of Public Health, Boston MA, USA
- Bureau of Epidemiologic Research, Academy of Athens, Athens, Greece
| | - Domenico Palli
- Molecular and Nutritional Epidemiology Unit, Cancer Research and Prevention Institute – ISPO, Florence, Italy
| | - Sabina Sieri
- Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy
| | - Rosario Tumino
- Cancer Registry and Histopathology Unit, “Civile - M.P.Arezzo” Hospital, ASP 7, Ragusa, Italy
| | - Carlotta Sacerdote
- Center for Cancer Prevention (CPO-Piemonte), Turin, Italy
- Human Genetic Foundation (HuGeF), Turin, Italy
| | - Henk van Kranen
- Centre for Nutrition and Health (CVG), National Institute for Public Health and the Environment, Bilthoven, The Netherlands
| | - H. Bas Bueno-de-Mesquita
- Centre for Nutrition and Health (CVG), National Institute for Public Health and the Environment, Bilthoven, The Netherlands
| | - Göran Hallmans
- Dept of Public Health and Clinical Medicine, Umeå University, Umeå, Sweden
| | - Mattias Johansson
- Dept of Public Health and Clinical Medicine, Umeå University, Umeå, Sweden
- International Agency for Research on Cancer, Lyon, France
| | | | - Mazda Jenab
- International Agency for Research on Cancer, Lyon, France
| | - David G. Cox
- Imperial College, London, United Kingdom
- INSERM U590, Centre Léon Bérard, Lyon France
| | | | | | | | - Rudolf Kaaks
- German Cancer Research Center (DKFZ), Heidelberg, Germany
- * E-mail:
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1380
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Abstract
Tuberous sclerosis (TSC) is a genetic disorder caused by heterozygous mutations in the TSC1 or TSC2 genes and is associated with autism spectrum disorders (ASD) in 20-60% of cases. In addition, altered TSC/mTOR signaling is emerging as a feature common to a subset of ASD. Recent findings, in animal models, show that restoration of the underlying molecular defect can improve neurological dysfunction in several of these models, even if treatment is initiated in adult animals, suggesting that pathophysiological processes in the mature brain contribute significantly to the overall neurological phenotype in these models. These findings suggest that windows for therapeutic intervention in ASD could be wider than thought previously.
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Affiliation(s)
- Dan Ehninger
- DZNE, German Center for Neurodegenerative Diseases, Ludwig-Erhard-Allee 2, 53175 Bonn, Germany,
| | - Alcino J. Silva
- University of California – Los Angeles, Departments of Neurobiology, Psychiatry & Biobehavioral Sciences, Psychology and the Brain Research Institute, 695 Charles E. Young Dr South, Los Angeles, CA 90095, USA,
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1381
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Oldham S. Obesity and nutrient sensing TOR pathway in flies and vertebrates: Functional conservation of genetic mechanisms. Trends Endocrinol Metab 2011; 22:45-52. [PMID: 21216618 PMCID: PMC3035994 DOI: 10.1016/j.tem.2010.11.002] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/09/2010] [Revised: 11/12/2010] [Accepted: 11/15/2010] [Indexed: 12/19/2022]
Abstract
The global prevalence of obesity has grown to epidemic proportions, and 400 million people are now considered to be obese. Excessive accumulation of dietary lipids (obesity) is a known risk factor for the development of deleterious metabolic conditions and has been strongly linked to the progression of heart disease and type 2 diabetes. Investigating the origin and effects of high-fat diet (HFD)-induced obesity and its genetic mediators is an important step in understanding the mechanisms that contribute to obesity. However, the mechanisms that underlie HFD pathophysiology have yet to be elucidated fully. Here we describe recent work in a Drosophila model to investigate the origin and genetic mechanisms that could underlie HFD-induced obesity, type 2 diabetes and cardiac dysfunction.
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Affiliation(s)
- Sean Oldham
- Sanford-Burnham Medical Research Institute, 10901 North Torrey Pines Road, La Jolla, CA 92037, USA.
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1382
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Banerjee S, Gianino SM, Gao F, Christians U, Gutmann DH. Interpreting mammalian target of rapamycin and cell growth inhibition in a genetically engineered mouse model of Nf1-deficient astrocytes. Mol Cancer Ther 2011; 10:279-91. [PMID: 21216928 DOI: 10.1158/1535-7163.mct-10-0654] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The identification of mammalian target of rapamycin (mTOR) as a major mediator of neurofibromatosis-1 (NF1) tumor growth has led to the initiation of clinical trials using rapamycin analogs. Previous studies from our laboratory have shown that durable responses to rapamycin treatment in a genetically engineered mouse model of Nf1 optic glioma require 20 mg/kg/day, whereas only transient tumor growth suppression was observed with 5 mg/kg/day rapamycin despite complete silencing of ribosomal S6 activity. To gain clinically relevant insights into the mechanism underlying this dose-dependent effect, we used Nf1-deficient glial cells in vitro and in vivo. First, there was an exponential relationship between blood and brain rapamycin levels. Second, we show that currently used biomarkers of mTOR pathway inhibition (phospho-S6, phospho-4EBP1, phospho-STAT3, and Jagged-1 levels) and tumor proliferation (Ki67) do not accurately reflect mTOR target inhibition or Nf1-deficient glial growth suppression. Third, the incomplete suppression of Nf1-deficient glial cell proliferation in vivo following 5 mg/kg/day rapamycin treatment reflects mTOR-mediated AKT activation, such that combined 5 mg/kg/day rapamycin and PI3-kinase (PI3K) inhibition or dual PI3K/mTOR inhibition recapitulates the growth suppressive effects of 20 mg/kg/day rapamycin. These new findings argue for the identification of more accurate biomarkers for rapamycin treatment response and provide reference preclinical data for comparing human rapamycin levels with target effects in the brain.
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Affiliation(s)
- Sutapa Banerjee
- Department of Neurology, Washington University School of Medicine, Box 8111, 660 South Euclid Avenue, St. Louis, MO 63110, USA
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1383
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Roy SG, Raikhel AS. The small GTPase Rheb is a key component linking amino acid signaling and TOR in the nutritional pathway that controls mosquito egg development. Insect Biochem Mol Biol 2011; 41:62-9. [PMID: 21035549 PMCID: PMC3022117 DOI: 10.1016/j.ibmb.2010.10.001] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2010] [Revised: 10/04/2010] [Accepted: 10/12/2010] [Indexed: 05/12/2023]
Abstract
Mosquitoes transmit numerous devastating human diseases because they require blood feeding for egg development. Previously, we have shown that the nutritional Target-of-Rapamycin (TOR) pathway mediates blood-meal activation of mosquito reproductive cycles. Blood-derived amino acid (AA) signaling through the nutrient-sensitive TOR kinase is critical for the transcriptional activation of the major yolk protein precursor (YPP) gene, vitellogenin (Vg), initiation of vitellogenesis and egg development. In this study, we provide in vitro and in vivo evidence that the Rheb GTPase (Ras Homologue Enriched in Brain), which is an upstream activator of TOR, is required for AA-mediated activation of the TOR pathway in the fat body of the mosquito Aedes aegypti. Using RNA interference (RNAi) methods, we showed that Rheb was indispensable in AA-induced phosphorylation of S6 kinase, a key downstream substrate of TOR activation. Rheb RNAi depletion resulted in significant downregulation of Vg transcription and translation in the mosquito fat body, which was monitored in vivo after blood meal or in vitro organ culture after AA stimulation. Egg development was severely hindered in mosquitoes with a Rheb RNAi depletion background. This study represents a notable step in deciphering molecular pathways controlling reproduction of this important vector of human diseases.
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Affiliation(s)
- Saurabh G. Roy
- Graduate Program in Cell, Molecular and Developmental Biology, Department of Entomology, and the Institute for Integrative Genome Biology, University of California, Riverside, CA 92521
| | - Alexander S. Raikhel
- Corresponding author. Tel.: +1 951 827 2129; Fax: +1 951 827 2130, (A.S. Raikhel)
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1384
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Affiliation(s)
- Dean A Fennell
- Centre for Cancer Research and Cell Biology, Queen's University Belfast, Belfast, BT9 7BL, Northern Ireland, UK.
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1385
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Pu X, Hildebrandt MA, Lu C, Lin J, Stewart DJ, Ye Y, Gu J, Spitz MR, Wu X. PI3K/PTEN/AKT/mTOR pathway genetic variation predicts toxicity and distant progression in lung cancer patients receiving platinum-based chemotherapy. Lung Cancer 2011; 71:82-8. [PMID: 20447721 PMCID: PMC2952281 DOI: 10.1016/j.lungcan.2010.04.008] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2009] [Revised: 02/08/2010] [Accepted: 04/03/2010] [Indexed: 11/18/2022]
Abstract
Non-small cell lung cancer (NSCLC) is still the leading cause of cancer-related deaths. The effect of the PI3K/PTEN/AKT/mTOR signaling pathway on cancer treatment, including NSCLC, has been well documented. In this study, we analyzed associations between genetic variations within this pathway and clinical outcomes following platinum-based chemotherapy in 168 patients with stage IIIB (wet) or stage IV NSCLC. Sixteen tagging SNPs in five core genes (PIK3CA, PTEN, AKT1, AKT2, and FRAP1) of this pathway and identified SNPs associated with development of toxicity and disease progression. We observed significantly increased toxicity for patients with PIK3CA:rs2699887 (OR: 3.86, 95% CI: 1.08-13.82). In contrast, a SNP in PTEN was associated with significantly reduced risk for chemotherapeutic toxicity (OR: 0.44, 95% CI: 0.20-0.95). We identified three SNPs in AKT1 resulting in significantly decreased risks of distant progression in patients carrying at least one variant allele with HRs of 0.66 (95% CI: 0.45-0.97), 0.52 (95% CI: 0.35-0.77), and 0.62 (95% CI: 0.42-0.91) for rs3803304, rs2498804, and rs1130214, respectively. Furthermore, these same variants conferred nearly 2-fold increased progression-free survival times. The current study provides evidence that genetic variations within the PI3K/PTEN/AKT/mTOR signaling pathway are associated with variation in clinical outcomes of NSCLC patients. With further validation, our findings may provide additional biomarkers for customized treatment of platinum-based chemotherapy for NSCLC.
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Affiliation(s)
- Xia Pu
- Departments of Epidemiology, The University of Texas M. D. Anderson Cancer Center, Houston, TX
| | | | - Charles Lu
- Thoracic/Head and Neck Medical Oncology, The University of Texas M. D. Anderson Cancer Center, Houston, TX
| | - Jie Lin
- Departments of Epidemiology, The University of Texas M. D. Anderson Cancer Center, Houston, TX
| | - David J. Stewart
- Thoracic/Head and Neck Medical Oncology, The University of Texas M. D. Anderson Cancer Center, Houston, TX
| | - Yuanqing Ye
- Departments of Epidemiology, The University of Texas M. D. Anderson Cancer Center, Houston, TX
| | - Jian Gu
- Departments of Epidemiology, The University of Texas M. D. Anderson Cancer Center, Houston, TX
| | - Margaret R. Spitz
- Departments of Epidemiology, The University of Texas M. D. Anderson Cancer Center, Houston, TX
| | - Xifeng Wu
- Departments of Epidemiology, The University of Texas M. D. Anderson Cancer Center, Houston, TX
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1386
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Velazquez-Arellano A, Ortega-Cuellar D, Hernandez-Mendoza A, Moreno-Arriola E. A heuristic model for paradoxical effects of biotin starvation on carbon metabolism genes in the presence of abundant glucose. Mol Genet Metab 2011; 102:69-77. [PMID: 20869286 DOI: 10.1016/j.ymgme.2010.08.021] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/04/2010] [Revised: 08/25/2010] [Accepted: 08/26/2010] [Indexed: 11/17/2022]
Abstract
We recently showed that in biotin starvation in yeast Saccharomyces cerevisiae, nematode Caenorhabditis elegans and rat Rattus norvegicus, despite abundant glucose provision, the expression of genes for glucose utilization and lipogenesis were lowered, and for fatty acid β-oxidation and gluconeogenesis were raised, and glycolytic/fermentative flow was reduced. This work explored the mechanisms of these results. We show that they are associated with ATP deficit and activation of the energy stress sensor AMP kinase (AMPK; Snf1 in yeast). Analysis of microarray results revealed extensive changes of transcripts for signal transduction pathways and transcription factors AMPK, SREBP-1c, ChREBP, NAMPT, PGC-1α, mTORC1 in rat, and their homologs in worm. In yeast the altered factor transcripts were Adr1, Cat8, Sip4, Mig1, HXK2, and Rgt1. The insulin pathway was negatively enriched (in rat and worm), whereas the adiponectins and JAK/STAT pathways were increased (present only in the rat; they activate AMPK). Together, all these changes explain the effects of biotin starvation on glucose utilization, energy status and carbon metabolism gene expression in a coherent manner across three phylogenetically distant eukaryotes and may have clinical significance in humans, since the effects are reminiscent of insulin resistance. We propose a general model for integrating these results in regulatory circuitries, according to the biology of each species, based on impaired anaplerosis due to pyruvate carboxylase deficiency, that have a basic underlying logic. In a preliminary test in yeast, aspartate corrects all the alterations produced by biotin starvation.
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Affiliation(s)
- Antonio Velazquez-Arellano
- Unidad de Genética de la Nutrición, Instituto de Investigaciones Biomédicas de la Universidad Nacional Autónoma de México, Mexico.
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1387
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Cui L, Ren Y, Yin H, Wang Y, Li D, Liu M, Zhu Y, Lin W, Tang XD, Gui Y, Zheng XL. Increased expression of tuberin in human uterine leiomyoma. Fertil Steril 2010; 95:1805-8. [PMID: 21145542 DOI: 10.1016/j.fertnstert.2010.11.028] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2010] [Revised: 09/21/2010] [Accepted: 11/09/2010] [Indexed: 01/05/2023]
Abstract
Female Eker rats harboring an insertional deletion in one copy of the tuberous sclerosis complex 2 (Tsc2) gene develop uterine leiomyoma, but the underlying mechanism of human uterine leiomyoma is not completely understood. To examine whether down-regulation of tuberin, a TSC2 gene product, is present in human uterine leiomyoma, we analyzed leiomyoma and matched myometrium tissues from 22 Chinese patients with Western blotting and real-time polymerase chain reaction analyses, and found that the expression of tuberin was significantly increased in leiomyoma tissues compared with matched myometrium tissues with inhibition of both the mammalian target of rapacmycin pathway and mitogen-activated protein kinase pathways.
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Affiliation(s)
- Lihua Cui
- Department of Biochemistry and Molecular Biology, Nankai University School of Medicine, Tianjin, People's Republic of China
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1388
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Abstract
Target of rapamycin (TOR), a member of the phosphatidylinositol kinase-related kinase family, plays a critical role in the regulation of growth, metabolism, development and survival, at both the cellular and the organismal levels. Two paralogous Tor genes, BmTor1 and BmTor2, were identified as a pair of inverted repeats in the genome of the silkworm Bombyx mori. The synteny of BmTor1 and CG8360 indicates that BmTor1 is the orthologue while BmTor2 is a duplicate. Analyses of the two BmTor genes at both the nucleotide and amino acid levels reveal that they are evolutionally and structurally conserved. The two BmTor genes had similar expression patterns of tissue distribution with highest levels in the nervous system, and nearly identical developmental change profiles with maximal levels during the 4(th) -larval-moulting and the larval-pupal transition stages. Furthermore, both BmTor genes were up-regulated by either starvation or the moulting hormone 20-hydroxyecdysone (20E), while BmTor2 was more sensitive to both treatments than BmTor1. For the first time, we have identified two copies of the Tor gene in a higher eukaryote, which are induced by starvation and 20E during the larval moulting and the larval-pupal transition stage.
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Affiliation(s)
- S Zhou
- Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
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1389
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Xu G, Li Y, An W, Zhao J, Xiang X, Ding L, Li Z, Guan Y, Wang X, Tang C, Zhu Y, Wang N, Li X, Mulholland M, Zhang W. Regulation of gastric hormones by systemic rapamycin. Peptides 2010; 31:2185-92. [PMID: 20804797 PMCID: PMC2995266 DOI: 10.1016/j.peptides.2010.08.018] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/18/2010] [Revised: 08/20/2010] [Accepted: 08/20/2010] [Indexed: 12/29/2022]
Abstract
The mammalian target of rapamycin (mTOR), an evolutionarily conserved serine-threonine kinase, is an intracellular fuel sensor critical for cellular energy homeostasis. Gastrointestinal endocrine cells play a vital role in the regulation of energy balance by secreting hormones that inform the brain about energy supply. Here we showed the localization of mTOR signaling molecules in more than 90% of gastric ghrelin cells and 36±3% of gastrin cells, while no somatostatin-positive cell showed phospho-S6K1 immunoreactivity. Inhibition of mTOR significantly stimulated expression of gastric ghrelin mRNA and protein, and the concentration of plasma ghrelin (2.06±0.34 ng/ml vs. 12.53±3.9 ng/ml, p<0.05), inhibited gastrin synthesis and secretion (75.01±6.71 pg/ml vs. 54.04±3.65 pg/ml, p<0.05), but had no effect on somatostatin production (165.2±25.07 pg/ml vs. 178.9±29.14 pg/ml, p=0.73). Gastric mTOR is a gastric sensor whose activity is linked to the differential regulation of gastric hormone production and release.
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Affiliation(s)
- Geyang Xu
- Department of Physiology and Pathophysiology, Peking University Health Science Center, Beijing 100191, China
| | - Yin Li
- Department of Physiology and Pathophysiology, Peking University Health Science Center, Beijing 100191, China
| | - Wenjiao An
- Department of Physiology and Pathophysiology, Peking University Health Science Center, Beijing 100191, China
| | - Jing Zhao
- Department of Physiology and Pathophysiology, Peking University Health Science Center, Beijing 100191, China
| | - Xinxin Xiang
- Department of Physiology and Pathophysiology, Peking University Health Science Center, Beijing 100191, China
| | - Li Ding
- Department of Physiology and Pathophysiology, Peking University Health Science Center, Beijing 100191, China
| | - Ziru Li
- Department of Physiology and Pathophysiology, Peking University Health Science Center, Beijing 100191, China
| | - Youfei Guan
- Department of Physiology and Pathophysiology, Peking University Health Science Center, Beijing 100191, China
| | - Xian Wang
- Department of Physiology and Pathophysiology, Peking University Health Science Center, Beijing 100191, China
| | - Chaoshu Tang
- Department of Physiology and Pathophysiology, Peking University Health Science Center, Beijing 100191, China
| | - Yi Zhu
- Department of Physiology and Pathophysiology, Peking University Health Science Center, Beijing 100191, China
| | - Nanping Wang
- Department of Physiology and Pathophysiology, Peking University Health Science Center, Beijing 100191, China
| | - Xiaoying Li
- Shanghai Institute of Endocrinology and Metabolism and Chinese-French Laboratory of Genomics and Life Sciences, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai 200025, China
| | - Michael Mulholland
- Department of Surgery, University of Michigan Medical Center, Ann Arbor, MI 48109-0346, USA
- Corresponding author: Weizhen Zhang, Department of Physiology and Pathophysiology, Peking University Health Science Center, Beijing 100191, China, Tel: 0086-10-82802183; Fax: 0086-10-82802183; Or Michael W. Mulholland, Department of Surgery, University of Michigan Medical Center, Ann Arbor, MI 48109-0346, USA, Tel: 734-936-3236;
| | - Weizhen Zhang
- Department of Physiology and Pathophysiology, Peking University Health Science Center, Beijing 100191, China
- Department of Surgery, University of Michigan Medical Center, Ann Arbor, MI 48109-0346, USA
- Corresponding author: Weizhen Zhang, Department of Physiology and Pathophysiology, Peking University Health Science Center, Beijing 100191, China, Tel: 0086-10-82802183; Fax: 0086-10-82802183; Or Michael W. Mulholland, Department of Surgery, University of Michigan Medical Center, Ann Arbor, MI 48109-0346, USA, Tel: 734-936-3236;
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1390
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Zhang Y, Zhang HM, Shi Y, Lustgarten M, Li Y, Qi W, Zhang BX, Van Remmen H. Loss of manganese superoxide dismutase leads to abnormal growth and signal transduction in mouse embryonic fibroblasts. Free Radic Biol Med 2010; 49:1255-62. [PMID: 20638473 PMCID: PMC3418666 DOI: 10.1016/j.freeradbiomed.2010.07.006] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2010] [Revised: 06/18/2010] [Accepted: 07/09/2010] [Indexed: 10/19/2022]
Abstract
Manganese superoxide dismutase (MnSOD) in the mitochondria plays an important role in cellular defense against oxidative damage. Homozygous MnSOD knockout (Sod2(-/-)) mice are neonatal lethal, indicating the essential role of MnSOD in early development. To investigate the potential cellular abnormalities underlying the aborted development of Sod2(-/-) mice, we examined the growth of isolated mouse embryonic fibroblasts (MEFs) from Sod2(-/-) mice. We found that the proliferation of Sod2(-/-) MEFs was significantly decreased compared with wild-type MEFs despite the absence of morphological differences. The Sod2(-/-) MEFs produced less cellular ATP, had lower O(2) consumption, generated more superoxide, and expressed less Prdx3 protein. Furthermore, the loss of MnSOD dramatically altered several markers involved in cell proliferation and growth, including decreased growth stimulatory function of mTOR signaling and enhanced growth inhibitory function of GSK-3β signaling. Interestingly, the G-protein-coupled receptor-mediated intracellular Ca(2+) signal transduction was also severely suppressed in Sod2(-/-) MEFs. Finally, the ratio of microtubule-associated protein light chain 3 (LC3)-II/LC3-I, an index of autophagic activity, was increased in Sod2(-/-) MEFs, consistent with a reduction in mTOR signal transduction. These data demonstrate that MnSOD deficiency results in alterations in several key signaling pathways, which may contribute to the lethal phenotype of Sod2(-/-) mice.
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Affiliation(s)
- Yiqiang Zhang
- Department of Physiology, University of Texas Health Science Center at San Antonio, San Antonio, Texas 78229
- Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center at San Antonio, San Antonio, Texas 78229
- South Texas Veterans Health Care System, San Antonio, Texas 78229
| | - Hong-Mei Zhang
- Department of Medicine, University of Texas Health Science Center at San Antonio, San Antonio, Texas 78229
| | - Yun Shi
- Department of Physiology, University of Texas Health Science Center at San Antonio, San Antonio, Texas 78229
| | - Michael Lustgarten
- Department of Physiology, University of Texas Health Science Center at San Antonio, San Antonio, Texas 78229
| | - Yan Li
- Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center at San Antonio, San Antonio, Texas 78229
| | - Wenbo Qi
- Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center at San Antonio, San Antonio, Texas 78229
| | - Bin-Xian Zhang
- Department of Medicine, University of Texas Health Science Center at San Antonio, San Antonio, Texas 78229
| | - Holly Van Remmen
- Department of Physiology, University of Texas Health Science Center at San Antonio, San Antonio, Texas 78229
- Department of Cellular and Structural Biology, University of Texas Health Science Center at San Antonio, San Antonio, Texas 78229
- Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center at San Antonio, San Antonio, Texas 78229
- South Texas Veterans Health Care System, San Antonio, Texas 78229
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1391
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Noh HS, Shin IW, Ha JH, Hah YS, Baek SM, Kim DR. Propofol protects the autophagic cell death induced by the ischemia/reperfusion injury in rats. Mol Cells 2010; 30:455-60. [PMID: 20821058 DOI: 10.1007/s10059-010-0130-z] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2010] [Revised: 07/20/2010] [Accepted: 07/29/2010] [Indexed: 10/19/2022] Open
Abstract
Autophagy has been implicated in cardiac cell death during ischemia/reperfusion (I/R). In this study we investigated how propofol, an antioxidant widely used for anesthesia, affects the autophagic cell death induced by the myocardial I/R injury. The infarction size in the myocardium was dramatically reduced in rats treated with propofol during I/R compared with untreated rats. A large number of autophagic vacuoles were observed in the cardiomyocytes of I/R-injured rats but rarely in I/R-injured rats treated with propofol. While LC3-II formation, an autophagy marker, was up-regulated in the I/R-injured myocardium, it was significantly down-regulated in the myocardial tissues of I/R-injured and propofol-treated rats. Moreover, propofol inhibited the I/R-induced expression of Beclin-1, and it accelerated phosphorylation of mTOR during I/R and Beclin-1/Bcl-2 interaction in cells, which indicates that it facilitates the inhibitory pathway of autophagy. These data suggest that propofol protects the autophagic cell death induced by the myocardial I/R injury.
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Affiliation(s)
- Hae Sook Noh
- Department of Biochemistry, Gyeongsang National University School of Medicine, Jinju, 660-751, Korea
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1392
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Pöllänen E, Ronkainen PHA, Horttanainen M, Takala T, Puolakka J, Suominen H, Sipilä S, Kovanen V. Effects of combined hormone replacement therapy or its effective agents on the IGF-1 pathway in skeletal muscle. Growth Horm IGF Res 2010; 20:372-379. [PMID: 20724185 DOI: 10.1016/j.ghir.2010.07.003] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/24/2010] [Revised: 06/30/2010] [Accepted: 07/21/2010] [Indexed: 01/14/2023]
Abstract
OBJECTIVES To investigate the effects of combined hormone replacement therapy (HRT) and its effective agents on the IGF-1 signaling pathway. DESIGN AND METHODS To examine the effects of HRT on skeletal muscle in vivo, we utilized pre- and post-intervention samples from a randomized double blinded trial with 50-57-year-old women. The intervention included the year-long use of either HRT preparation (2 mg 17β-estradiol, E₂; 1mg norethisterone acetate, NETA, n=10) or placebo (CO, n=9). Microarray technology and quantitative PCR (qPCR) were used to study the expression of insulin-like growth factor I (IGF-1) and its splice variants as well as IGF-1 receptor, Akt1, mTOR, FOXO1, FOXO3, atrogin, estrogen receptors and androgen receptor in muscle samples. Serum concentrations of IGF-1, E(2) and testosterone were measured. C2C12 myotubes were fed with E₂ or NETA followed by analyzing the expression of essentially the same gene transcripts as in human samples by qPCR and phosphorylation of Akt and mTOR by Western blotting. RESULTS The gene expression of IGF-1 and its splice variant, IGF-1Ec (also known as the mechano growth factor or MGF), mTOR, FOXO3, and AR was up-regulated among the HRT users compared to the CO (P<0.05), while Akt1 was down-regulated (P<0.05). The change in the level of IGF-1Ec transcript correlated positively with muscle size at post-intervention (r=0.5, P<0.05). In C2C12 myotubes, no statistically significant effects of either E₂ or NETA at the level of gene transcripts studied were identified. The amount of phosphorylated Akt appeared to respond to NETA, albeit the response was not statistically significant. Phosphorylation of mTOR did not respond to either of the treatments. CONCLUSION Year-long postmenopausal HRT was found to affect the expression of the genes along the IGF-1 signaling cascade reflecting the higher muscle mass compared to the CO women. By using cell culture model we were, however, unable to confirm the possible differential role of E₂ and NETA. It appears that the synchronous presence of both effective agents of the HRT or the presence of yet unidentified microenvironmental factors providing proper paracrine signals naturally existing in the intact muscle tissue is critical for appropriate signaling via sex steroid-IGF-1 axis to occur.
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MESH Headings
- Estradiol/blood
- Estradiol/therapeutic use
- Estrogen Replacement Therapy
- Female
- Forkhead Box Protein O1
- Forkhead Box Protein O3
- Forkhead Transcription Factors/biosynthesis
- Forkhead Transcription Factors/genetics
- Humans
- Insulin-Like Growth Factor I/analysis
- Insulin-Like Growth Factor I/biosynthesis
- Insulin-Like Growth Factor I/genetics
- Middle Aged
- Muscle Fibers, Skeletal/chemistry
- Muscle Fibers, Skeletal/drug effects
- Muscle Proteins/biosynthesis
- Muscle Proteins/genetics
- Muscle, Skeletal/chemistry
- Muscle, Skeletal/drug effects
- Norethindrone/analogs & derivatives
- Norethindrone/therapeutic use
- Norethindrone Acetate
- Protein Isoforms/biosynthesis
- Protein Isoforms/genetics
- Proto-Oncogene Proteins c-akt/biosynthesis
- Proto-Oncogene Proteins c-akt/genetics
- Randomized Controlled Trials as Topic
- Receptor, IGF Type 1/biosynthesis
- Receptor, IGF Type 1/genetics
- Receptors, Androgen/biosynthesis
- Receptors, Androgen/genetics
- Receptors, Estrogen/biosynthesis
- Receptors, Estrogen/genetics
- SKP Cullin F-Box Protein Ligases/biosynthesis
- SKP Cullin F-Box Protein Ligases/genetics
- TOR Serine-Threonine Kinases/biosynthesis
- TOR Serine-Threonine Kinases/genetics
- Testosterone/blood
- Transcription, Genetic/drug effects
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Affiliation(s)
- Eija Pöllänen
- Gerontology Research Centre, University of Jyväskylä, P.O. Box 35, FIN-40014 University of Jyväskylä, Jyväskylä, Finland
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1393
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Boyd KD, Walker BA, Wardell CP, Ross FM, Gregory WM, Davies FE, Morgan GJ. High expression levels of the mammalian target of rapamycin inhibitor DEPTOR are predictive of response to thalidomide in myeloma. Leuk Lymphoma 2010; 51:2126-9. [PMID: 20858096 DOI: 10.3109/10428194.2010.509893] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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1394
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Ma T, Hoeffer CA, Capetillo-Zarate E, Yu F, Wong H, Lin MT, Tampellini D, Klann E, Blitzer RD, Gouras GK. Dysregulation of the mTOR pathway mediates impairment of synaptic plasticity in a mouse model of Alzheimer's disease. PLoS One 2010; 5. [PMID: 20862226 PMCID: PMC2942840 DOI: 10.1371/journal.pone.0012845] [Citation(s) in RCA: 178] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2010] [Accepted: 08/16/2010] [Indexed: 01/22/2023] Open
Abstract
Background The mammalian target of rapamycin (mTOR) is an evolutionarily conserved Ser/Thr protein kinase that plays a pivotal role in multiple fundamental biological processes, including synaptic plasticity. We explored the relationship between the mTOR pathway and β-amyloid (Aβ)-induced synaptic dysfunction, which is considered to be critical in the pathogenesis of Alzheimer's disease (AD). Methodology/Principal Findings We provide evidence that inhibition of mTOR signaling correlates with impairment in synaptic plasticity in hippocampal slices from an AD mouse model and in wild-type slices exposed to exogenous Aβ1-42. Importantly, by up-regulating mTOR signaling, glycogen synthase kinase 3 (GSK3) inhibitors rescued LTP in the AD mouse model, and genetic deletion of FK506-binding protein 12 (FKBP12) prevented Aβ-induced impairment in long-term potentiation (LTP). In addition, confocal microscopy demonstrated co-localization of intraneuronal Aβ42 with mTOR. Conclusions/Significance These data support the notion that the mTOR pathway modulates Aβ-related synaptic dysfunction in AD.
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Affiliation(s)
- Tao Ma
- Department of Neurology and Neuroscience, Weill Cornell Medical College, New York, New York, United States of America
| | - Charles A. Hoeffer
- Center for Neural Science, New York University, New York, New York, United States of America
| | - Estibaliz Capetillo-Zarate
- Department of Neurology and Neuroscience, Weill Cornell Medical College, New York, New York, United States of America
| | - Fangmin Yu
- Department of Neurology and Neuroscience, Weill Cornell Medical College, New York, New York, United States of America
| | - Helen Wong
- Center for Neural Science, New York University, New York, New York, United States of America
| | - Michael T. Lin
- Department of Neurology and Neuroscience, Weill Cornell Medical College, New York, New York, United States of America
| | - Davide Tampellini
- Department of Neurology and Neuroscience, Weill Cornell Medical College, New York, New York, United States of America
| | - Eric Klann
- Center for Neural Science, New York University, New York, New York, United States of America
| | - Robert D. Blitzer
- Department of Pharmacology and Systems Therapeutics, Mount Sinai School of Medicine, New York, New York, United States of America
| | - Gunnar K. Gouras
- Department of Neurology and Neuroscience, Weill Cornell Medical College, New York, New York, United States of America
- Rockefeller University, New York, New York, United States of America
- * E-mail:
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1395
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Zheng W, Shi D, Ji X, Han Y, Liao Q. [Antiproliferation of cardamonin associated with mRNA expression of mTOR, Raptor and Rictor]. Zhongguo Zhong Yao Za Zhi 2010; 35:2318-2323. [PMID: 21137347] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
OBJECTIVE To investigate the antiproliferation effect of cardamonin (CAR) and its possible mechanisms on human umbilical artery smooth muscle cells (HUASMCs) cultured in the mimicking insulin resistance (IR) medium. METHOD Proliferation of HUASMCs was assayed by MTT method. The mRNA expression of mTOR, Raptor and Rictor was detected by a real-time PCR. The expression content was calculated by Livak method using internal control of beta-actin. RESULT The proliferation of HUASMCs cultured in the mimicking IR medium was significantly increased. Both in normal and mimic IR culture medium, cells proliferation was inhibited by CAR (1 x 10(-5), 1 x 10(-4) mol x L(-1)). Pretreated with PD98059 and LY294002, cell proliferation induced by phosphatidic acid (PA) was inhibited, and the mRNA expression of mTOR, Raptor and Rictor was significantly decreased by CAR in the mimic IR medium. CONCLUSION It is implicated that antiproliferation of CAR is involved in mRNA expression decrease of mTOR and its relative protein Raptor and Rictor.
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Affiliation(s)
- Wei Zheng
- Department of Pharmacy, Fuzhou General Hospital of Nanjing Military Command, Fuzhou 350025, China.
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1396
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Suganya R, Chen SL, Lu KH. Target of rapamycin in the oriental fruit fly Bactrocera dorsalis (Hendel): its cloning and effect on yolk protein expression. Arch Insect Biochem Physiol 2010; 75:45-56. [PMID: 20734415 DOI: 10.1002/arch.20383] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Target of rapamycin (TOR), a serine/threonine protein kinase, is involved in regulating a number of growth and developmental processes of an organism, including yolk protein synthesis in insects. In this study, TOR gene was isolated, designated BdTOR (GenBank accession no. FJ167395), from the oriental fruit fly Bactrocera dorsalis (Hendel). Quantitative RT-PCR showed a higher expression of BdTOR in the pupa than in other developmental stages, as well as in ovary than in the fat body. Downregulation of BdTOR activity by rapamycin treatment and RNA interference (RNAi) in vivo resulted in a significant reduction in yolk protein transcripts in both fat body and ovary, with a substantial reduction in ovary size. However, an unexpected increase in the expression of yolk protein gene was observed in adult ovary 9 days after rapamycin treatment. Taken together, the results suggest the involvement of BdTOR in the regulation of yolk protein synthesis in B. dorsalis.
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Affiliation(s)
- R Suganya
- Department of Entomology, National Chung Hsing University, Taichung, Taiwan, Republic of China
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1397
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Kumar D, Konkimalla S, Yadav A, Sataranatarajan K, Kasinath BS, Chander PN, Singhal PC. HIV-associated nephropathy: role of mammalian target of rapamycin pathway. Am J Pathol 2010; 177:813-21. [PMID: 20581056 PMCID: PMC2913356 DOI: 10.2353/ajpath.2010.100131] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 04/16/2010] [Indexed: 12/22/2022]
Abstract
Both glomerular and tubular lesions are characterized by a proliferative phenotype in HIV-associated nephropathy. We hypothesized that mammalian target of rapamycin (mTOR) contributes to the development of the HIVAN phenotype. Both glomerular and tubular epithelial cells showed enhanced expression of phospho (p)-mTOR in HIV-1 transgenic mice (Tgs). In addition, renal tissues of transgenic mice (RT-Tg) showed enhanced phosphorylation of p70S6 kinase and an associated diminished phosphorylation of eEF2. Moreover, RT-Tgs showed enhanced phosphorylation of 4EBP1 and eIF4B; these findings indicated activation of the mTOR pathway in RT-Tgs. To test our hypothesis, age- and sex-matched control mice and Tgs were administered either saline or rapamycin (an inhibitor of the mTOR pathway) for 4 weeks. Tgs receiving rapamycin not only showed inhibition of the mTOR-associated downstream signaling but also displayed attenuated renal lesions. RT-Tgs showed enhanced expression of hypoxia-inducible factor-alpha and also displayed increased expression of vascular endothelial growth factor; on the other hand, rapamycin inhibited RT-Tg expression of both hypoxia-inducible factor-alpha and vascular endothelial growth factor. We conclude that the mTOR pathway contributes to the HIVAN phenotype and that inhibition of the mTOR pathway can be used as a therapeutic strategy to alter the course of HIVAN.
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Affiliation(s)
- Dileep Kumar
- Department of Immunology, Feinstein Institute for Medical Research, Manhasset, New York, USA
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1398
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Abstract
Neurofibromatosis type 1 (NF-1) and tuberous sclerosis complex (TSC) are two familial syndromes known as phakomatoses that may be associated with endocrine tumours. These hereditary cutaneous conditions affect the central nervous system and are characterised by the development of hamartomas. Over the past 20 years, there have been major advances in our understanding of the molecular basis of these diseases. Both NF-1 and TSC are disorders of unregulated progression through the cell cycle, in which causative genes behave as tumour suppressor genes. The pathogenesis of these familial syndromes is linked by the shared regulation of a common pathway, the protein kinase mammalian target of rapamycin (mTOR). Additional related disorders that also converge on the mTOR pathway include Peutz-Jeghers syndrome and Cowden syndrome. All of these inherited cancer syndromes are associated with characteristic skin findings that offer a clue to their recognition and treatment. The discovery of mTOR inhibitors has led to a possible new therapeutic modality for patients with endocrine tumours as part of these familial syndromes.
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Affiliation(s)
- Maya B Lodish
- Section on Endocrinology Genetics, Program on Developmental Endocrinology Genetics, Eunice Kennedy Shriver National Institute of Child Health and Paediatric Endocrinology Inter-Institute Training Program, National Institutes of Health, Bethesda, MD 20892, USA.
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1399
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Vozianov AF, Butenko AK, Zak KP. [Task-orientated therapy (target-therapy) directed to patients with renal cell carcinoma]. Lik Sprava 2010:3-11. [PMID: 21268291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Two main ways playing a cardinal role in the pathogenesis of metastatic renal cell carcinoma (mRCC) have been identified in recent years, they are following: 1) a way of the mutation of a gene suppressor VHL (Van-Hippel-Lindau), stimulating various types of tyrosine-kinases participating in the development of tumors; 2) mTOR way, where ramapycyn plays a leading role, which effect proliferation and angiogenesis of mRCC. This discovery enabled the development of a new generation of highly effective medications for target-therapy of mRCCC--tyrosine-kinases inhibitors (VEGFR-1, VEGFR-2, VEGFR-3, PDGFR-alpha/PDGFR-beta, Raf-kinases, etc.) sunitimab, sorafenib, pazopanib, axitinib, etc. and mTOR inhibitors--everolimus and temsirolimus as well as monoclonal neutralising antibody VEGF (bevasizumab). The review is devoted to the analysis of antitumor activity, patient tolerance and side effect of these preparations in the system therapy of patients with mRCC.
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1400
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Zhou H, Huang XY, Yang T, Wang T, Xu D, Wen FQ. [Effect and mechanism of LY294002 on growth of fibrosarcoma cell line HT1080]. Sichuan Da Xue Xue Bao Yi Xue Ban 2010; 41:20-23. [PMID: 20369463] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
OBJECTIVE To investigate the effect and mechanism of LY294002 on growth of fibrosarcoma cell line HT1080. METHODS The proliferation inhibitory rate of HT1080 cells treated by LY294002 at doses of 5, 10, 25, 50, 100 micromol/L for 12 and 24 h, respectively, was evaluated using SunBio Am-Blue method. HT1080 cells were divided into two groups, that is, A and B. The A group was control group without treatment. The B group received LY294002 (100 micromol/L) for 24 h. The changes of cell morphology and quantity were observed by phase contrast microscope. The apoptosis rate of HT1080 cells was detected by flow cytometry. And the protein expression of p-Akt and p-mTOR in HT1080 cells were detected by Western Blotting. RESULTS The proliferation of HT1080 cells was inhibited in time- and dose- dependent manner by LY294002. After the treatment of 100 micromol/L LY294002 for 24 h, the growth of HT1080 cell line was remarkably inhibited by LY294002. The rate of apoptosis increased. And the protein expression of p-Akt (0.23 +/- 0.01) and p-mTOR (0.32 +/- 0.06) in LY294002 group was lower than p-Akt (0.63 +/- 0.02) and p-mTOR (0.71 +/- 0.02) in control group (P<0. 01). CONCLUSION LY294002 can inhibit the growth of HT1080 cells through PI3K-mTOR pathway. PI3K-mTOR pathway presents an appealing therapeutic target on fibrosarcoma.
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Affiliation(s)
- Hong Zhou
- Department of Respiratory Medicine, West China Hospital, Sichuan University, Chengdu 610041, China
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