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Wang P, Laster K, Jia X, Dong Z, Liu K. Targeting CRAF kinase in anti-cancer therapy: progress and opportunities. Mol Cancer 2023; 22:208. [PMID: 38111008 PMCID: PMC10726672 DOI: 10.1186/s12943-023-01903-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Accepted: 11/16/2023] [Indexed: 12/20/2023] Open
Abstract
The RAS/mitogen-activated protein kinase (MAPK) signaling cascade is commonly dysregulated in human malignancies by processes driven by RAS or RAF oncogenes. Among the members of the RAF kinase family, CRAF plays an important role in the RAS-MAPK signaling pathway, as well as in the progression of cancer. Recent research has provided evidence implicating the role of CRAF in the physiological regulation and the resistance to BRAF inhibitors through MAPK-dependent and MAPK-independent mechanisms. Nevertheless, the effectiveness of solely targeting CRAF kinase activity remains controversial. Moreover, the kinase-independent function of CRAF may be essential for lung cancers with KRAS mutations. It is imperative to develop strategies to enhance efficacy and minimize toxicity in tumors driven by RAS or RAF oncogenes. The review investigates CRAF alterations observed in cancers and unravels the distinct roles of CRAF in cancers propelled by diverse oncogenes. This review also seeks to summarize CRAF-interacting proteins and delineate CRAF's regulation across various cancer hallmarks. Additionally, we discuss recent advances in pan-RAF inhibitors and their combination with other therapeutic approaches to improve treatment outcomes and minimize adverse effects in patients with RAF/RAS-mutant tumors. By providing a comprehensive understanding of the multifaceted role of CRAF in cancers and highlighting the latest developments in RAF inhibitor therapies, we endeavor to identify synergistic targets and elucidate resistance pathways, setting the stage for more robust and safer combination strategies for cancer treatment.
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Affiliation(s)
- Penglei Wang
- Department of Pathophysiology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, 450000, China
- Tianjian Laboratory for Advanced Biomedical Sciences, Zhengzhou, 450052, Henan, China
- China-US (Henan) Hormel Cancer Institute, Zhengzhou, 450000, China
| | - Kyle Laster
- China-US (Henan) Hormel Cancer Institute, Zhengzhou, 450000, China
| | - Xuechao Jia
- Department of Pathophysiology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, 450000, China
- Tianjian Laboratory for Advanced Biomedical Sciences, Zhengzhou, 450052, Henan, China
- China-US (Henan) Hormel Cancer Institute, Zhengzhou, 450000, China
| | - Zigang Dong
- Department of Pathophysiology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, 450000, China.
- Tianjian Laboratory for Advanced Biomedical Sciences, Zhengzhou, 450052, Henan, China.
- China-US (Henan) Hormel Cancer Institute, Zhengzhou, 450000, China.
- Department of Pathophysiology, School of Basic Medical Sciences, China-US (Henan) Hormel Cancer Institute, AMS, College of Medicine, Zhengzhou University, 100 Kexue Avenue, Zhengzhou, 450001, Henan, China.
| | - Kangdong Liu
- Department of Pathophysiology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, 450000, China.
- Tianjian Laboratory for Advanced Biomedical Sciences, Zhengzhou, 450052, Henan, China.
- China-US (Henan) Hormel Cancer Institute, Zhengzhou, 450000, China.
- Department of Pathophysiology, School of Basic Medical Sciences, China-US (Henan) Hormel Cancer Institute, AMS, College of Medicine, Zhengzhou University, 100 Kexue Avenue, Zhengzhou, 450001, Henan, China.
- Basic Medicine Sciences Research Center, Academy of Medical Sciences, Zhengzhou University, Zhengzhou, 450052, Henan, China.
- State Key Laboratory of Esophageal Cancer Prevention and Treatment, Zhengzhou University, Zhengzhou, 450000, Henan, China.
- Provincial Cooperative Innovation Center for Cancer Chemoprevention, Zhengzhou University, Zhengzhou, 450000, Henan, China.
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Enomoto A, Fukasawa T, Terunuma H, Nakagawa K, Yoshizaki A, Sato S, Miyagawa K. Decrease in MAP3Ks expression enhances the cell death caused by hyperthermia. Int J Hyperthermia 2022; 39:200-208. [PMID: 35042442 DOI: 10.1080/02656736.2021.2024281] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
PURPOSE Hyperthermia is a promising anticancer treatment modality. However, the molecular mechanism underlying the thermal sensitivity of tumor cells is largely unknown. The aim of this study was to clarify how biochemical changes triggered by heat stimulate antitumor activity. METHODS AND MATERIALS The expression levels of various MAPK members in HeLa cells with or without hyperthermia were evaluated by western blotting and RT-PCR. The intracellular Ca2+ concentration [Ca2+]i was monitored by digital imaging using CaTM-2 AM. An in vitro cleavage assay was used to determine whether calcium-dependent protease calpain cleaves MAPK components. Cell proliferation and clonogenicity were assessed in the absence or presence of siRNAs targeting MAPK members. RESULTS Hyperthermia decreased the levels of MAP3K TAK1, RAF1 and MEKK2 but not of the downstream MAP2K and MAPK members. The hyperthermia-induced degradation of TAK1 and MEKK2 was rescued by either the proteasome inhibitor MG132 or the calpain inhibitor ALLN; however, RAF1 was not affected by the inhibitors. Heat induced down regulation of RAF1. Hyperthermia increased [Ca2+]i and calpain I expression. The calcium ionophore A23187 decreased TAK1 and MEKK2 levels. An in vitro cleavage assay demonstrated that TAK1 and MEKK2 are calpain I substrates. Knockdown of TAK1, RAF1 and MEKK2 suppressed cell proliferation and clonogenicity. CONCLUSIONS Hyperthermia decreased the levels of MAP3K TAK1, RAF1 and MEKK2, without reduction of the downstream components in the MAP3K-MAP2K-MAPK cascade, by a calpain-dependent degradation pathway or transcriptional regulation. TAK1, RAF1 and/or MEKK2 play crucial roles in cell proliferation and clonogenicity and are potential molecular targets for hyperthermia.
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Affiliation(s)
- Atsushi Enomoto
- Laboratory of Molecular Radiology, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Takemichi Fukasawa
- Laboratory of Molecular Radiology, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.,Department of Dermatology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | | | - Keiichi Nakagawa
- Comprehensive Radiation Oncology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Ayumi Yoshizaki
- Department of Dermatology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Shinichi Sato
- Department of Dermatology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Kiyoshi Miyagawa
- Laboratory of Molecular Radiology, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
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Lambrou GI, Adamaki M, Hatziagapiou K, Vlahopoulos S. Gene Expression and Resistance to Glucocorticoid-Induced Apoptosis in Acute Lymphoblastic Leukemia: A Brief Review and Update. Curr Drug Res Rev 2021; 12:131-149. [PMID: 32077838 DOI: 10.2174/2589977512666200220122650] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Revised: 12/29/2019] [Accepted: 01/23/2020] [Indexed: 01/18/2023]
Abstract
BACKGROUND Resistance to glucocorticoid (GC)-induced apoptosis in Acute Lymphoblastic Leukemia (ALL), is considered one of the major prognostic factors for the disease. Prednisolone is a corticosteroid and one of the most important agents in the treatment of acute lymphoblastic leukemia. The mechanics of GC resistance are largely unknown and intense ongoing research focuses on this topic. AIM The aim of the present study is to review some aspects of GC resistance in ALL, and in particular of Prednisolone, with emphasis on previous and present knowledge on gene expression and signaling pathways playing a role in the phenomenon. METHODS An electronic literature search was conducted by the authors from 1994 to June 2019. Original articles and systematic reviews selected, and the titles and abstracts of papers screened to determine whether they met the eligibility criteria, and full texts of the selected articles were retrieved. RESULTS Identification of gene targets responsible for glucocorticoid resistance may allow discovery of drugs, which in combination with glucocorticoids may increase the effectiveness of anti-leukemia therapies. The inherent plasticity of clinically evolving cancer justifies approaches to characterize and prevent undesirable activation of early oncogenic pathways. CONCLUSION Study of the pattern of intracellular signal pathway activation by anticancer drugs can lead to development of efficient treatment strategies by reducing detrimental secondary effects.
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Affiliation(s)
- George I Lambrou
- First Department of Pediatrics, National and Kapodistrian University of Athens, Choremeio Research Laboratory, Athens, Greece
| | - Maria Adamaki
- First Department of Pediatrics, National and Kapodistrian University of Athens, Choremeio Research Laboratory, Athens, Greece
| | - Kyriaki Hatziagapiou
- First Department of Pediatrics, National and Kapodistrian University of Athens, Choremeio Research Laboratory, Athens, Greece
| | - Spiros Vlahopoulos
- First Department of Pediatrics, National and Kapodistrian University of Athens, Choremeio Research Laboratory, Athens, Greece
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Aravindan S, Ramraj S, Kandasamy K, Thirugnanasambandan SS, Somasundaram DB, Herman TS, Aravindan N. Hormophysa triquerta polyphenol, an elixir that deters CXCR4- and COX2-dependent dissemination destiny of treatment-resistant pancreatic cancer cells. Oncotarget 2017; 8:5717-5734. [PMID: 27974694 PMCID: PMC5351584 DOI: 10.18632/oncotarget.13900] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2016] [Accepted: 11/23/2016] [Indexed: 12/20/2022] Open
Abstract
Therapy-resistant pancreatic cancer (PC) cells play a crucial role in tumor relapse, recurrence, and metastasis. Recently, we showed the anti-PC potential of an array of seaweed polyphenols and identified efficient drug deliverables. Herein, we investigated the benefit of one such deliverable, Hormophysa triquerta polyphenol (HT-EA), in regulating the dissemination physiognomy of therapy-resistant PC cells in vitro,and residual PC in vivo. Human PC cells exposed to ionizing radiation (IR), with/without HT-EA pre-treatment were examined for the alterations in the tumor invasion/metastasis (TIM) transcriptome (93 genes, QPCR-profiling). Utilizing a mouse model of residual PC, we investigated the benefit of HT-EA in the translation regulation of crucial TIM targets (TMA-IHC). Radiation activated 30, 50, 15, and 38 TIM molecules in surviving Panc-1, Panc-3.27, BxPC3, and MiaPaCa-2 cells. Of these, 15, 44, 12, and 26 molecules were suppressed with HT-EA pre-treatment. CXCR4 and COX2 exhibited cell-line-independent increases after IR, and was completely suppressed with HT-EA, across all PC cells. HT-EA treatment resulted in translational repression of IR-induced CXCR4, COX2, β-catenin, MMP9, Ki-67, BAPX, PhPT-1, MEGF10, and GRB10 in residual PC. Muting CXCR4 or COX2 regulated the migration/invasion potential of IR-surviving cells, while forced expression of CXCR4 or COX2 significantly increased migration/invasion capabilities of PC cells. Further, treatment with HT-EA significantly inhibited IR-induced and CXCR4/COX2 forced expression-induced PC cell migration/invasion. This study (i) documents the TIM blueprint in therapy-resistant PC cells, (ii) defines the role of CXCR4 and COX2 in induced metastatic potential, and (iii) recognizes the potential of HT-EA in deterring the CXCR4/COX2-dependent dissemination destiny of therapy-resistant residual PC cells.
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Affiliation(s)
- Sheeja Aravindan
- Department of Marine Sciences, Center of Advanced Study in Marine Biology, Annamalai University, Parangipettai, TN, India
- Stephenson Cancer Center, Oklahoma City, OK, USA
| | - Satishkumar Ramraj
- Department of Radiation Oncology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Kathiresan Kandasamy
- Department of Marine Sciences, Center of Advanced Study in Marine Biology, Annamalai University, Parangipettai, TN, India
| | | | - Dinesh Babu Somasundaram
- Department of Radiation Oncology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Terence S. Herman
- Stephenson Cancer Center, Oklahoma City, OK, USA
- Department of Radiation Oncology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Natarajan Aravindan
- Department of Radiation Oncology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
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Kai M, Niinuma T, Kitajima H, Yamamoto E, Harada T, Aoki H, Maruyama R, Toyota M, Sasaki Y, Sugai T, Tokino T, Nakase H, Suzuki H. TET1 Depletion Induces Aberrant CpG Methylation in Colorectal Cancer Cells. PLoS One 2016; 11:e0168281. [PMID: 27977763 PMCID: PMC5158030 DOI: 10.1371/journal.pone.0168281] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Accepted: 11/29/2016] [Indexed: 01/02/2023] Open
Abstract
Aberrant DNA methylation is commonly observed in colorectal cancer (CRC), but the underlying mechanism is not fully understood. 5-hydroxymethylcytosine levels and TET1 expression are both reduced in CRC, while epigenetic silencing of TET1 is reportedly associated with the CpG island methylator phenotype. In the present study, we aimed to clarify the relationship between loss of TET1 and aberrant DNA methylation in CRC. Stable TET1 knockdown clones were established using Colo320DM cells, which express high levels of TET1, and HCT116 cells, which express TET1 at a level similar to that in normal colonic tissue. Infinium HumanMethylation450 BeadChip assays revealed increased levels of 5-methylcytosine at more than 10,000 CpG sites in TET1-depleted Colo320DM cells. Changes in DNA methylation were observed at various positions within the genome, including promoters, gene bodies and intergenic regions, and the altered methylation affected expression of a subset of genes. By contrast, TET1 knockdown did not significantly affect DNA methylation in HCT116 cells. However, TET1 depletion was associated with attenuated effects of 5-aza-2’-deoxycytidine on gene expression profiles in both cell lines. These results suggest that loss of TET1 may induce aberrant DNA methylation and may attenuate the effect of 5-aza-2’-deoxycytidine in CRC cells.
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Affiliation(s)
- Masahiro Kai
- Department of Molecular Biology, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Takeshi Niinuma
- Department of Molecular Biology, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Hiroshi Kitajima
- Department of Molecular Biology, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Eiichiro Yamamoto
- Department of Molecular Biology, Sapporo Medical University School of Medicine, Sapporo, Japan
- Department of Gastroenterology and Hepatology, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Taku Harada
- Department of Molecular Biology, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Hironori Aoki
- Department of Molecular Biology, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Reo Maruyama
- Department of Molecular Biology, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Mutsumi Toyota
- Department of Molecular Biology, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Yasushi Sasaki
- Medical Genome Science, Research Institute for Frontier Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Tamotsu Sugai
- Department of Molecular Diagnostic Pathology, Iwate Medical University, Morioka, Japan
| | - Takashi Tokino
- Medical Genome Science, Research Institute for Frontier Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Hiroshi Nakase
- Department of Gastroenterology and Hepatology, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Hiromu Suzuki
- Department of Molecular Biology, Sapporo Medical University School of Medicine, Sapporo, Japan
- * E-mail:
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Reddy MA, Das S, Zhuo C, Jin W, Wang M, Lanting L, Natarajan R. Regulation of Vascular Smooth Muscle Cell Dysfunction Under Diabetic Conditions by miR-504. Arterioscler Thromb Vasc Biol 2016; 36:864-73. [PMID: 26941017 DOI: 10.1161/atvbaha.115.306770] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Accepted: 02/09/2016] [Indexed: 12/14/2022]
Abstract
OBJECTIVE Diabetes mellitus accelerates proatherogenic and proinflammatory phenotype of vascular smooth muscle cell (VSMC) associated with vascular complications. Evidence shows that microRNAs (miRNAs) play key roles in VSMC functions, but their role under diabetic conditions is unclear. We profiled miRNAs in VSMC from diabetic mice and examined their role in VSMC dysfunction. APPROACH AND RESULTS High throughput small RNA-sequencing identified 135 differentially expressed miRNAs in VSMC from type 2 diabetic db/db mice (db/dbVSMC) versus nondiabetic db/+ mice. Several of these miRNAs were known to regulate VSMC functions. We further focused on miR-504, because it was highly upregulated in db/dbVSMC, and its function in VSMC is unknown. miR-504 and its host gene Fgf13 were significantly increased in db/dbVSMC and in aortas from db/db mice. Bioinformatics analysis predicted that miR-504 targets including signaling adaptor Grb10 and transcription factor Egr2 could regulate growth factor signaling. We experimentally validated Grb10 and Egr2 as novel targets of miR-504. Overexpression of miR-504 in VSMC inhibited contractile genes and enhanced extracellular signal-regulated kinase 1/2 activation, proliferation, and migration. These effects were blocked by miR-504 inhibitors. Grb10 knockdown mimicked miR-504 functions and increased inflammatory genes. Egr2 knockdown-inhibited anti-inflammatory Socs1 and increased proinflammatory genes. Furthermore, high glucose and palmitic acid upregulated miR-504 and inflammatory genes, but downregulated Grb10. CONCLUSIONS Diabetes mellitus misregulates several miRNAs including miR-504 that can promote VSMC dysfunction. Because changes in many of these miRNAs are sustained in diabetic VSMC even after in vitro culture, they may be involved in metabolic memory of vascular complications. Targeting such mechanisms could offer novel therapeutic strategies for diabetic complications.
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Affiliation(s)
- Marpadga A Reddy
- From the Department of Diabetes Complications and Metabolism, Beckman Research Institute of City of Hope, Duarte, CA
| | - Sadhan Das
- From the Department of Diabetes Complications and Metabolism, Beckman Research Institute of City of Hope, Duarte, CA
| | - Chen Zhuo
- From the Department of Diabetes Complications and Metabolism, Beckman Research Institute of City of Hope, Duarte, CA
| | - Wen Jin
- From the Department of Diabetes Complications and Metabolism, Beckman Research Institute of City of Hope, Duarte, CA
| | - Mei Wang
- From the Department of Diabetes Complications and Metabolism, Beckman Research Institute of City of Hope, Duarte, CA
| | - Linda Lanting
- From the Department of Diabetes Complications and Metabolism, Beckman Research Institute of City of Hope, Duarte, CA
| | - Rama Natarajan
- From the Department of Diabetes Complications and Metabolism, Beckman Research Institute of City of Hope, Duarte, CA.
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Mukhopadhyay A, Ravikumar G, Dwarkanath P, Meraaj H, Thomas A, Crasta J, Thomas T, Kurpad A, Sridhar T. Placental expression of the insulin receptor binding protein GRB10: Relation to human fetoplacental growth and fetal gender. Placenta 2015; 36:1225-30. [DOI: 10.1016/j.placenta.2015.09.006] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Revised: 08/13/2015] [Accepted: 09/08/2015] [Indexed: 11/27/2022]
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Keogh K, Kenny DA, Kelly AK, Waters SM. Insulin secretion and signaling in response to dietary restriction and subsequent re-alimentation in cattle. Physiol Genomics 2015; 47:344-54. [PMID: 26015430 DOI: 10.1152/physiolgenomics.00002.2015] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Accepted: 05/22/2015] [Indexed: 01/04/2023] Open
Abstract
The objectives of this study were to examine systemic insulin response to a glucose tolerance test (GTT) and transcript abundance of genes of the insulin signaling pathway in skeletal muscle, during both dietary restriction and re-alimentation-induced compensatory growth. Holstein Friesian bulls were blocked to one of two groups: 1) restricted feed allowance for 125 days (period 1) (RES, n = 15) followed by ad libitum feeding for 55 days (period 2) or 2) ad libitum access to feed throughout (periods 1 and 2) (ADLIB, n = 15). On days 90 and 36 of periods 1 and 2, respectively, a GTT was performed. M. longissimus dorsi biopsies were harvested from all bulls on days 120 and 15 of periods 1 and 2, respectively, and RNA-Seq analysis was performed. RES displayed a lower growth rate during period 1 (RES: 0.6 kg/day, ADLIB: 1.9 kg/day; P < 0.001), subsequently gaining more during re-alimentation (RES: 2.5 kg/day, ADLIB: 1.4 kg/day; P < 0.001). Systemic insulin response to glucose administration was lower in RES in period 1 (P < 0.001) with no difference observed during period 2. The insulin signaling pathway in M. longissimus dorsi was enriched (P < 0.05) in response to dietary restriction but not during re-alimentation (P > 0.05). Genes differentially expressed in the insulin signaling pathway suggested a greater sensitivity to insulin in skeletal muscle, with pleiotropic effects of insulin signaling interrupted during dietary restriction. Collectively, these results indicate increased sensitivity to glucose clearance and skeletal muscle insulin signaling during dietary restriction; however, no overall role for insulin was apparent in expressing compensatory growth.
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Affiliation(s)
- Kate Keogh
- Animal and Bioscience Research Department, Animal and Grassland Research and Innovation Centre, Teagasc, Dunsany, County Meath, Ireland; and UCD School of Agriculture and Food Science, Belfield, Dublin, Ireland
| | - David A Kenny
- Animal and Bioscience Research Department, Animal and Grassland Research and Innovation Centre, Teagasc, Dunsany, County Meath, Ireland; and
| | - Alan K Kelly
- UCD School of Agriculture and Food Science, Belfield, Dublin, Ireland
| | - Sinéad M Waters
- Animal and Bioscience Research Department, Animal and Grassland Research and Innovation Centre, Teagasc, Dunsany, County Meath, Ireland; and
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Grb10 is involved in BCR-ABL-positive leukemia in mice. Leukemia 2014; 29:858-68. [DOI: 10.1038/leu.2014.283] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2014] [Revised: 08/14/2014] [Accepted: 09/05/2014] [Indexed: 11/08/2022]
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Fantauzzo KA, Soriano P. PI3K-mediated PDGFRα signaling regulates survival and proliferation in skeletal development through p53-dependent intracellular pathways. Genes Dev 2014; 28:1005-17. [PMID: 24788519 PMCID: PMC4018488 DOI: 10.1101/gad.238709.114] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
PI3K is the main downstream effector of PDGFRα signaling during murine skeletal development. Fantauzzo et al. discovered skeletal defects in embryos in which PDGFRα is unable to bind PI3K. They identified 56 proteins that are phosphorylated by Akt downstream from PI3K-mediated PDGFRα signaling. Several of these proteins, including Ybox1, mediate cell survival through regulation of p53. These findings identify p53 as a novel effector downstream from PI3K-engaged PDGFRα signaling that regulates survival and proliferation during skeletal development in vivo. Previous studies have identified phosphatidylinositol 3-kinase (PI3K) as the main downstream effector of PDGFRα signaling during murine skeletal development. Autophosphorylation mutant knock-in embryos in which PDGFRα is unable to bind PI3K (PdgfraPI3K/PI3K) exhibit skeletal defects affecting the palatal shelves, shoulder girdle, vertebrae, and sternum. To identify proteins phosphorylated by Akt downstream from PI3K-mediated PDGFRα signaling, we immunoprecipitated Akt phosphorylation substrates from PDGF-AA-treated primary mouse embryonic palatal mesenchyme (MEPM) lysates and analyzed the peptides by nanoliquid chromatography coupled to tandem mass spectrometry (nano-LC-MS/MS). Our analysis generated a list of 56 proteins, including 10 that regulate cell survival and proliferation. We demonstrate that MEPM cell survival is impaired in the presence of a PI3K inhibitor and that PdgfraPI3K/PI3K-derived MEPMs do not proliferate in response to PDGF-AA treatment. Several of the identified Akt phosphorylation targets, including Ybox1, mediate cell survival through regulation of p53. We show that Ybox1 binds both the Trp53 promoter and the p53 protein and that expression of Trp53 is significantly decreased upon PDGF-AA treatment in MEPMs. Finally, we demonstrate that introduction of a Trp53-null allele attenuates the vertebral defects found in PdgfraPI3K/PI3K neonates. Our findings identify p53 as a novel effector downstream from PI3K-engaged PDGFRα signaling that regulates survival and proliferation during skeletal development in vivo.
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Affiliation(s)
- Katherine A Fantauzzo
- Department of Developmental and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA
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Kusne Y, Goldberg EL, Parker SS, Hapak SM, Maskaykina IY, Chew WM, Limesand KH, Brooks HL, Price TJ, Sanai N, Nikolich-Zugich J, Ghosh S. Contrasting effects of chronic, systemic treatment with mTOR inhibitors rapamycin and metformin on adult neural progenitors in mice. AGE (DORDRECHT, NETHERLANDS) 2014; 36:199-212. [PMID: 23949159 PMCID: PMC3889877 DOI: 10.1007/s11357-013-9572-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2013] [Accepted: 07/08/2013] [Indexed: 06/02/2023]
Abstract
The chronic and systemic administration of rapamycin extends life span in mammals. Rapamycin is a pharmacological inhibitor of mTOR. Metformin also inhibits mTOR signaling but by activating the upstream kinase AMPK. Here we report the effects of chronic and systemic administration of the two mTOR inhibitors, rapamycin and metformin, on adult neural stem cells of the subventricular region and the dendate gyrus of the mouse hippocampus. While rapamycin decreased the number of neural progenitors, metformin-mediated inhibition of mTOR had no such effect. Adult-born neurons are considered important for cognitive and behavioral health, and may contribute to improved health span. Our results demonstrate that distinct approaches of inhibiting mTOR signaling can have significantly different effects on organ function. These results underscore the importance of screening individual mTOR inhibitors on different organs and physiological processes for potential adverse effects that may compromise health span.
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Affiliation(s)
- Yael Kusne
- />Neuroscience Graduate Program, Arizona State University, Phoenix, AZ 85287 USA
| | - Emily L. Goldberg
- />Department of Immunobiology, The University of Arizona, Tucson, AZ 85724 USA
- />Department of Nutritional Sciences, The University of Arizona, Tucson, AZ 85721 USA
| | - Sara S. Parker
- />Department of Cellular and Molecular Medicine, The University of Arizona, Tucson, AZ 85724 USA
| | - Sophie M. Hapak
- />Department of Cellular and Molecular Medicine, The University of Arizona, Tucson, AZ 85724 USA
| | - Irina Y. Maskaykina
- />Department of Cellular and Molecular Medicine, The University of Arizona, Tucson, AZ 85724 USA
| | | | - Kirsten H. Limesand
- />Department of Nutritional Sciences, The University of Arizona, Tucson, AZ 85721 USA
| | - Heddwen L. Brooks
- />Department of Physiology, University of Arizona, Tucson, AZ 85724 USA
| | - Theodore J. Price
- />Department of Pharmacology, University of Arizona, Tucson, AZ 85724 USA
| | - Nader Sanai
- />Neuroscience Graduate Program, Arizona State University, Phoenix, AZ 85287 USA
- />Barrow Brain Tumor Research Center, Barrow Neurological Institute, Phoenix, AZ 85013 USA
| | | | - Sourav Ghosh
- />Neuroscience Graduate Program, Arizona State University, Phoenix, AZ 85287 USA
- />Department of Cellular and Molecular Medicine, The University of Arizona, Tucson, AZ 85724 USA
- />Arizona Cancer Center, Tucson, AZ 85724 USA
- />Barrow Brain Tumor Research Center, Barrow Neurological Institute, Phoenix, AZ 85013 USA
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Kabir NN, Kazi JU. Grb10 is a dual regulator of receptor tyrosine kinase signaling. Mol Biol Rep 2014; 41:1985-92. [PMID: 24420853 DOI: 10.1007/s11033-014-3046-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2013] [Accepted: 01/04/2014] [Indexed: 10/25/2022]
Abstract
The adaptor protein Grb10 is a close homolog of Grb7 and Grb14. These proteins are characterized by an N-terminal proline-rich region, a Ras-GTPase binding domain, a PH domain, an SH2 domain and a BPS domain in between the PH and SH2 domains. Human Grb10 gene encodes three splice variants. These variants show differences in functionality. Grb10 associates with multiple proteins including tyrosine kinases in a tyrosine phosphorylation dependent or independent manner. Association with multiple proteins allows Grb10 to regulate different signaling pathways resulting in different biological consequences.
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Affiliation(s)
- Nuzhat N Kabir
- Laboratory of Computational Biochemistry, KN Biomedical Research Institute, Bagura Road, Barisal, Bangladesh
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Desbuquois B, Carré N, Burnol AF. Regulation of insulin and type 1 insulin-like growth factor signaling and action by the Grb10/14 and SH2B1/B2 adaptor proteins. FEBS J 2013. [PMID: 23190452 DOI: 10.1111/febs.12080] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The effects of insulin and type 1 insulin-like growth factor (IGF-1) on metabolism, growth and survival are mediated by their association with specific receptor tyrosine kinases, which results in both receptor and substrate phosphorylation. Phosphotyrosine residues on receptors and substrates provide docking sites for signaling proteins containing SH2 (Src homology 2) domains, including molecular adaptors. This review focuses on the regulation of insulin/IGF-1 signaling and action by two adaptor families with a similar domain organization: the growth factor receptor-bound proteins Grb7/10/14 and the SH2B proteins. Both Grb10/14 and SH2B1/B2 associate with the activation loop of insulin/IGF-1 receptors through their SH2 domains, but association of Grb10/14 also involves their unique BPS domain. Consistent with Grb14 binding as a pseudosubstrate to the kinase active site, insulin/IGF-induced activation of receptors and downstream signaling pathways in cultured cells is inhibited by Grb10/14 adaptors, but is potentiated by SH2B1/B2 adaptors. Accordingly, Grb10 and Grb14 knockout mice show improved insulin/IGF sensitivity in vivo, and, for Grb10, overgrowth and increased skeketal muscle and pancreatic β-cell mass. Conversely, SH2B1-depleted mice display insulin and IGF-1 resistance, with peripheral depletion leading to reduced adiposity and neuronal depletion leading to obesity through associated leptin resistance. Grb10/14 and SH2B1 adaptors also modulate insulin/IGF-1 action by interacting with signaling components downstream of receptors and exert several tissue-specific effects. The identification of Grb10/14 and SH2B1 as physiological regulators of insulin signaling and action, together with observations that variants at their gene loci are associated with obesity and/or insulin resistance, highlight them as potential therapeutic targets for these conditions.
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Affiliation(s)
- Bernard Desbuquois
- Institut Cochin, Départment d'Endocrinologie, Métabolisme et Cancer, Université Paris-Descartes, Institut National de la Santé et de la Recherche Médicale, Unité 1016, et Centre National de la Recherche Scientifique, Unité Mixte de Recherche, Paris, France
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Singh M, Martinez AR, Govindaraju S, Lee BS. HuR inhibits apoptosis by amplifying Akt signaling through a positive feedback loop. J Cell Physiol 2012; 228:182-9. [PMID: 22674407 DOI: 10.1002/jcp.24120] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Human antigen R (HuR) is a post-transcriptional regulator of gene expression that plays a key role in stabilizing mRNAs during cellular stress, leading to enhanced survival. HuR expression is tightly regulated through multiple transcription and post-transcriptional controls. Although HuR is known to stabilize a subset of mRNAs involved in cell survival, its role in the survival pathway of PI3-kinase/Akt signaling is unclear. Here, we show that in renal proximal tubule cells, HuR performs a central role in cell survival by amplifying Akt signaling in a positive feedback loop. Key to this feedback loop is HuR-mediated stabilization of mRNA encoding Grb10, an adaptor protein whose expression is critical for Akt activation. Stimulation of Akt by interaction with Grb10 then activates NF-κB, which further enhances HuR mRNA and protein expression. This feedback loop is active in unstressed cells, but its effects are increased during stress. Therefore, this study demonstrates a central role for HuR in Akt signaling and reveals a mechanism by which modest changes in HuR levels below or above normal may be amplified, potentially resulting in cell death or cellular transformation.
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Affiliation(s)
- Mamata Singh
- Department of Physiology and Cell Biology, The Ohio State University College of Medicine, Columbus, Ohio, USA
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FLT3 signals via the adapter protein Grb10 and overexpression of Grb10 leads to aberrant cell proliferation in acute myeloid leukemia. Mol Oncol 2012; 7:402-18. [PMID: 23246379 DOI: 10.1016/j.molonc.2012.11.003] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2012] [Accepted: 11/22/2012] [Indexed: 01/17/2023] Open
Abstract
The adaptor protein Grb10 plays important roles in mitogenic signaling. However, its roles in acute myeloid leukemia (AML) are predominantly unknown. Here we describe the role of Grb10 in FLT3-ITD-mediated AML. We observed that Grb10 physically associates with FLT3 in response to FLT3-ligand (FL) stimulation through FLT3 phospho-tyrosine 572 and 793 residues and constitutively associates with oncogenic FLT3-ITD. Furthermore endogenous Grb10-FLT3 association was observed in OCI-AML-5 cells. Grb10 expression did not alter FLT3 receptor activation or stability in Ba/F3-FLT3 cells. However, expression of Grb10 enhanced FL-induced Akt phosphorylation without affecting Erk or p38 phosphorylation in Ba/F3-FLT3-WT and Ba/F3-FLT3-ITD. Selective Grb10 depletion reduced Akt phosphorylation in Ba/F3-FLT3-WT and OCI-AML-5 cells. Grb10 transduces signal from FLT3 by direct interaction with p85 and Ba/F3-FLT3-ITD cells expressing Grb10 exhibits higher STAT5 activation. Grb10 regulates the cell cycle by increasing cell population in S-phase. Expression of Grb10 furthermore resulted in an increased proliferation and survival of Ba/F3-FLT3-ITD cells as well as increased colony formation in semisolid culture. Grb10 expression was significantly increased in AML patients compared to healthy controls and was also elevated in patients carrying FLT3-ITD mutants. The elevated Grb10 expression partially correlated to relapse as well as to poor prognosis. These results suggest that Grb10 binds to both normal and oncogenic FLT3 and induces PI3K-Akt and STAT5 signaling pathways resulting in an enhanced proliferation, survival and colony formation of hematopoietic cells.
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Abstract
This review is focusing on a critical mediator of embryonic and postnatal development with multiple implications in inflammation, neoplasia, and other pathological situations in brain and peripheral tissues. These morphogenetic guidance and dependence processes are involved in several malignancies targeting the epithelial and immune systems including the progression of human colorectal cancers. We consider the most important findings and their impact on basic, translational, and clinical cancer research. Expected information can bring new cues for innovative, efficient, and safe strategies of personalized medicine based on molecular markers, protagonists, signaling networks, and effectors inherent to the Netrin axis in pathophysiological states.
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Doiron B, Hu W, Norton L, DeFronzo RA. Lentivirus shRNA Grb10 targeting the pancreas induces apoptosis and improved glucose tolerance due to decreased plasma glucagon levels. Diabetologia 2012; 55:719-28. [PMID: 22222503 DOI: 10.1007/s00125-011-2414-z] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2011] [Accepted: 11/24/2011] [Indexed: 01/09/2023]
Abstract
AIMS/HYPOTHESIS The physiological significance of growth factor receptor-bound protein-10 (GRB10) in the pancreas is unclear. We hypothesised that GRB10 is involved in pancreatic apoptosis, as GRB10 binds with a family of cell-survival-related proteins implicated in apoptosis. METHODS Lentiviral vector small hairpin RNA (shRNA) targeting Grb10 was injected in vivo via an intraductal pancreatic route to target pancreatic tissues in adult mice, which were studied 2 weeks post-injection. RESULTS Using the TUNEL assay, we demonstrated for the first time that in vivo injection of lentivirus shRNA Grb10 directly into the adult mouse pancreas induced apoptosis in both exocrine and endocrine (alpha and beta) cells. This effect was more pronounced in alpha cells. Levels of the pro-apoptotic protein BCL2-interacting mediator of cell death (BIM) in islets was higher in lentivirus shRNA Grb10 than in lentivirus shRNA scramble mice. In the apoptotic pathway, BIM initiates apoptosis signalling, leading to activation of the caspase cascade. We propose that, when complexed with GRB10, BIM is inactive. On activation by stress signalling or, in the present study, following injection of lentivirus shRNA Grb10 into pancreas, BIM becomes unbound from GRB10 and activates the caspase cascade. Indeed, caspase-3 activity in islets was higher in the experimental than in the control group. Apoptosis induced by shRNA Grb10 resulted in a 34% decrease in fasting plasma glucagon. Mice injected with shRNA Grb10 had improved glucose tolerance despite reduced insulin secretion compared with shRNA scramble control mice. CONCLUSIONS/INTERPRETATION GRB10 is critically involved in alpha cell survival and, as a result, plays an important role in regulating basal glucagon secretion and glucose tolerance in adult mice.
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Affiliation(s)
- B Doiron
- Diabetes Division, University of Texas Health Science Center at San Antonio, Mail Code 7886, 7703 Floyd Curl Drive, San Antonio, TX 78299, USA.
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Polzien L, Baljuls A, Albrecht M, Hekman M, Rapp UR. BAD contributes to RAF-mediated proliferation and cooperates with B-RAF-V600E in cancer signaling. J Biol Chem 2011; 286:17934-44. [PMID: 21317286 DOI: 10.1074/jbc.m110.177345] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
BAD (Bcl-2 antagonist of cell death) belongs to the proapoptotic BH3-only subfamily of Bcl-2 proteins. Physiological activity of BAD is highly controlled by phosphorylation. To further analyze the regulation of BAD function, we investigated the role of recently identified phosphorylation sites on BAD-mediated apoptosis. We found that in contrast to the N-terminal phosphorylation sites, the serines 124 and 134 act in an antiapoptotic manner because the replacement by alanine led to enhanced cell death. Our results further indicate that RAF kinases represent, besides PAK1, BAD serine 134 phosphorylating kinases. Importantly, in the presence of wild type BAD, co-expression of survival kinases, such as RAF and PAK1, leads to a strongly increased proliferation, whereas substitution of serine 134 by alanine abolishes this process. Furthermore, we identified BAD serine 134 to be strongly involved in survival signaling of B-RAF-V600E-containing tumor cells and found that phosphorylation of BAD at this residue is critical for efficient proliferation in these cells. Collectively, our findings provide new insights into the regulation of BAD function by phosphorylation and its role in cancer signaling.
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Affiliation(s)
- Lisa Polzien
- Department of Microbiology, Biocenter, University of Würzburg, 97074 Würzburg, Germany.
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Aurisicchio L, Ciliberto G. Patented cancer vaccines: the promising leads. Expert Opin Ther Pat 2010; 20:647-60. [DOI: 10.1517/13543771003720483] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Polzien L, Baljuls A, Rennefahrt UEE, Fischer A, Schmitz W, Zahedi RP, Sickmann A, Metz R, Albert S, Benz R, Hekman M, Rapp UR. Identification of novel in vivo phosphorylation sites of the human proapoptotic protein BAD: pore-forming activity of BAD is regulated by phosphorylation. J Biol Chem 2009; 284:28004-28020. [PMID: 19667065 DOI: 10.1074/jbc.m109.010702] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
BAD is a proapoptotic member of the Bcl-2 protein family that is regulated by phosphorylation in response to survival factors. Although much attention has been devoted to the identification of phosphorylation sites in murine BAD, little data are available with respect to phosphorylation of human BAD protein. Using mass spectrometry, we identified here besides the established phosphorylation sites at serines 75, 99, and 118 several novel in vivo phosphorylation sites within human BAD (serines 25, 32/34, 97, and 124). Furthermore, we investigated the quantitative contribution of BAD targeting kinases in phosphorylating serine residues 75, 99, and 118. Our results indicate that RAF kinases represent, besides protein kinase A, PAK, and Akt/protein kinase B, in vivo BAD-phosphorylating kinases. RAF-induced phosphorylation of BAD was reduced to control levels using the RAF inhibitor BAY 43-9006. This phosphorylation was not prevented by MEK inhibitors. Consistently, expression of constitutively active RAF suppressed apoptosis induced by BAD and the inhibition of colony formation caused by BAD could be prevented by RAF. In addition, using the surface plasmon resonance technique, we analyzed the direct consequences of BAD phosphorylation by RAF with respect to association with 14-3-3 and Bcl-2/Bcl-X(L) proteins. Phosphorylation of BAD by active RAF promotes 14-3-3 protein association, in which the phosphoserine 99 represented the major binding site. Finally, we show here that BAD forms channels in planar bilayer membranes in vitro. This pore-forming capacity was dependent on phosphorylation status and interaction with 14-3-3 proteins. Collectively, our findings provide new insights into the regulation of BAD function by phosphorylation.
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Affiliation(s)
- Lisa Polzien
- Institute for Medical Radiation and Cell Research, University of Wuerzburg, 97078 Wuerzburg
| | - Angela Baljuls
- Institute for Medical Radiation and Cell Research, University of Wuerzburg, 97078 Wuerzburg
| | - Ulrike E E Rennefahrt
- Institute for Medical Radiation and Cell Research, University of Wuerzburg, 97078 Wuerzburg
| | - Andreas Fischer
- Institute for Medical Radiation and Cell Research, University of Wuerzburg, 97078 Wuerzburg
| | - Werner Schmitz
- Institute of Physiological Chemistry, University of Wuerzburg, 97078 Wuerzburg
| | - Rene P Zahedi
- Institute for Analytical Sciences, Department of Bioanalytics, 44139 Dortmund
| | - Albert Sickmann
- Institute for Analytical Sciences, Department of Bioanalytics, 44139 Dortmund; Medical Proteome Center, Ruhr University of Bochum, 44801 Bochum, Germany
| | - Renate Metz
- Institute for Medical Radiation and Cell Research, University of Wuerzburg, 97078 Wuerzburg
| | - Stefan Albert
- Julius-von-Sachs Institute for Biosciences, University of Wuerzburg, 97078 Wuerzburg
| | - Roland Benz
- Institute of Biotechnology, University of Wuerzburg, 97078 Wuerzburg
| | - Mirko Hekman
- Institute for Medical Radiation and Cell Research, University of Wuerzburg, 97078 Wuerzburg
| | - Ulf R Rapp
- Institute for Medical Radiation and Cell Research, University of Wuerzburg, 97078 Wuerzburg.
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Akerlund M, Carmignac V, Schéele S, Durbeej M. Laminin alpha1 domains LG4-5 are essential for the complete differentiation of visceral endoderm. Cell Tissue Res 2009; 338:129-37. [PMID: 19657675 DOI: 10.1007/s00441-009-0845-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2008] [Accepted: 07/10/2009] [Indexed: 02/03/2023]
Abstract
The heterotrimeric basement membrane protein laminin-111 is essential for early mouse embryogenesis. Its beta1 and gamma1 chains are crucial for endoderm differentiation and for the formation of basement membranes, whereas alpha1 chain null mice only lack the extraembryonic Reichert's membrane. Nevertheless, mice deficient in the cell-binding alpha1 globular domains 4-5 (LG4-5) have a more severe phenotype than animals devoid of the whole alpha1 chain, as these domains are required for the formation of a polarized ectoderm. However, the influence of the alpha1LG4-5 domains on endoderm differentiation is unclear. We have used microarray analysis to compare the expression profiles of normal and alpha1LG4-5-deficient embryoid bodies and show that genes encoding secreted plasma proteins and proteins involved in endocytosis are reduced in alpha1LG4-5-deficient embryoid bodies, indicating incomplete differentiation of the visceral endoderm. Moreover, mice lacking alpha1LG4-5 display endoderm disorganization and a defective expression of the endoderm marker Dab2. We hypothesize that alpha1LG4-5 domains provide an autocrine signal necessary for the complete differentiation of a functional visceral endoderm and vital signals for the polarization of the epiblast.
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Affiliation(s)
- Mikael Akerlund
- Department of Experimental Medical Science, Lund University, BMC B12, 221 84, Lund, Sweden.
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Taniai E, Kawai M, Dewa Y, Nishimura J, Harada T, Saegusa Y, Matsumoto S, Takahashi M, Mitsumori K, Shibutani M. Crosstalk between PTEN/Akt2 and TGFβ signaling involving EGF receptor down-regulation during the tumor promotion process from the early stage in a rat two-stage hepatocarcinogenesis model. Cancer Sci 2009; 100:813-20. [DOI: 10.1111/j.1349-7006.2009.01120.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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Craig EA, Stevens MV, Vaillancourt RR, Camenisch TD. MAP3Ks as central regulators of cell fate during development. Dev Dyn 2009; 237:3102-14. [PMID: 18855897 DOI: 10.1002/dvdy.21750] [Citation(s) in RCA: 96] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
The cytoplasmic serine/threonine kinases transduce extracellular signals into regulatory events that impact cellular responses. The induction of one kinase triggers the activation of several downstream kinases, leading to the regulation of transcription factors to affect gene function. This arrangement allows for the kinase cascade to be amplified, and integrated according to the cellular context. An upstream mitogen or growth factor signal initiates a module of three kinases: a mitogen-activated protein (MAP) kinase kinase kinase (MAPKKK; e.g., Raf) that phosphorylates and activates a MAP kinase kinase (MAPKK; e.g., MEK) and finally activation of MAP kinase (MAPK; e.g., ERK). Thus, this MAP3K-MAP2K-MAPK module represents critical effectors that regulate extracellular stimuli into cellular responses, such as differentiation, proliferation, and apoptosis all of which function during development. There are 21 characterized MAP3Ks that activate known MAP2Ks, and they function in many aspects of developmental biology. This review summarizes known transduction routes linked to each MAP3K and highlights mouse models that provide clues to their physiological functions. This perspective reveals that some of these MAP3K effectors may have redundant functions, and also serve as unique nexus depending on the context of the signaling pathway.
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Affiliation(s)
- Evisabel A Craig
- Department of Pharmacology and Toxicology, College of Pharmacy, University of Arizona, Tucson, Arizona, USA
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Deng Y, Zhang M, Riedel H. Mitogenic roles of Gab1 and Grb10 as direct cellular partners in the regulation of MAP kinase signaling. J Cell Biochem 2008; 105:1172-82. [DOI: 10.1002/jcb.21829] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Fueller J, Becker M, Sienerth AR, Fischer A, Hotz C, Galmiche A. C-RAF activation promotes BAD poly-ubiquitylation and turn-over by the proteasome. Biochem Biophys Res Commun 2008; 370:552-6. [PMID: 18402774 DOI: 10.1016/j.bbrc.2008.03.141] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2008] [Accepted: 03/18/2008] [Indexed: 11/28/2022]
Abstract
BAD, a member of the BCL2 family, exhibits an original mode of regulation by phosphorylation. In the present report, we examine the role of the kinase C-RAF in this process. We show that the inducible activation of C-RAF promotes the rapid phosphorylation of BAD on Serine-112 (Ser-75 in the human protein), through a cascade involving the kinases MEK and RSK. Our findings reveal a new aspect of the regulation of BAD protein and its control by the RAF pathway: we find that C-RAF activation promotes BAD poly-ubiquitylation in a phosphorylation-dependent fashion, and increases the turn-over of this protein through proteasomal degradation.
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Affiliation(s)
- Jochen Fueller
- Institut für Medizinische Strahlenkunde und Zellforschung (MSZ), University of Würzburg, Versbacher Strasse 5, D-97078, Würzburg, Germany
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Immunity to Growth Factor Receptor–Bound Protein 10, a Signal Transduction Molecule, Inhibits the Growth of Breast Cancer in Mice. Cancer Res 2008; 68:2463-70. [DOI: 10.1158/0008-5472.can-07-5685] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Autocrine induction of invasion and metastasis by tumor-associated trypsin inhibitor in human colon cancer cells. Oncogene 2008; 27:4024-33. [DOI: 10.1038/onc.2008.42] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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