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Effect of 2-arachidonoylglycerol on myosin light chain phosphorylation and platelet activation: The role of phosphatidylinositol 3 kinase/AKT pathway. Biochimie 2014; 105:182-91. [DOI: 10.1016/j.biochi.2014.07.014] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2014] [Accepted: 07/14/2014] [Indexed: 11/22/2022]
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202
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Westin JR. Status of PI3K/Akt/mTOR pathway inhibitors in lymphoma. CLINICAL LYMPHOMA, MYELOMA & LEUKEMIA 2014; 14:335-42. [PMID: 24650973 PMCID: PMC4125533 DOI: 10.1016/j.clml.2014.01.007] [Citation(s) in RCA: 72] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2013] [Revised: 01/21/2014] [Accepted: 01/23/2014] [Indexed: 02/07/2023]
Abstract
The phosphatidylinositol-3-kinase (PI3K) pathway is well known to regulate a wide variety of essential cellular functions, including glucose metabolism, translational regulation of protein synthesis, cell proliferation, apoptosis, and survival. Aberrations in the PI3K pathway are among the most frequently observed in cancer, and include amplifications, rearrangements, mutations, and loss of regulators. As a net result of these anomalies, the PI3K pathway is activated in many malignancies, including in Hodgkin and non-Hodgkin lymphomas, and yields a competitive growth and survival advantage, increased metastatic ability, and resistance to conventional therapy. Numerous inhibitors targeting various nodes in the PI3K pathway are undergoing clinical development, and their current status in lymphoma will be the focus of this review.
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Affiliation(s)
- Jason R Westin
- Division of Cancer Medicine, Department of Lymphoma and Myeloma, University of Texas M.D. Anderson Cancer Center, Houston, TX.
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203
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Phosphoinositide 3-kinase β mediates microvascular endothelial repair of thrombotic microangiopathy. Blood 2014; 124:2142-9. [DOI: 10.1182/blood-2014-02-557975] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Key Points
Endothelial PI3Kβ is not required in the quiescent vasculature, but PI3Kβ loss confers sensitivity for thrombotic microangiopathy. PI3Kβ activity is required for endothelial angiogenic differentiation and microvascular repair.
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204
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Győri D, Csete D, Benkő S, Kulkarni S, Mandl P, Dobó-Nagy C, Vanhaesebroeck B, Stephens L, Hawkins PT, Mócsai A. The phosphoinositide 3-kinase isoform PI3Kβ regulates osteoclast-mediated bone resorption in humans and mice. Arthritis Rheumatol 2014; 66:2210-21. [PMID: 24719382 PMCID: PMC4314683 DOI: 10.1002/art.38660] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2013] [Accepted: 04/03/2014] [Indexed: 11/23/2022]
Abstract
Objective While phosphoinositide 3-kinases (PI3Ks) are involved in various intracellular signal transduction processes, the specific functions of the different PI3K isoforms are poorly understood. We have previously shown that the PI3Kβ isoform is required for arthritis development in the K/BxN serum–transfer model. Since osteoclasts play a critical role in pathologic bone loss during inflammatory arthritis and other diseases, we undertook this study to test the role of PI3Kβ in osteoclast development and function using a combined genetic and pharmacologic approach. Methods The role of PI3Kβ in primary human and murine osteoclast cultures was tested with the PI3Kβ-selective inhibitor TGX221 and by using PI3Kβ−/− mice. The trabecular bone architecture of PI3Kβ−/− mice was evaluated using micro–computed tomography and histomorphometric analyses. Results The expression of PI3Kβ was strongly and specifically up-regulated during in vitro osteoclast differentiation. In vitro development of large multinucleated osteoclasts from human or murine progenitors and their resorption capacity were strongly reduced by the PI3Kβ inhibitor TGX221 or by the genetic deficiency of PI3Kβ. This was likely due to defective cytoskeletal reorganization and vesicular trafficking, since PI3Kβ−/− mouse multinucleated cells failed to form actin rings and retained intracellular acidic vesicles and cathepsin K. In contrast, osteoclast-specific gene expression and the survival and apoptosis of osteoclasts were not affected. PI3Kβ−/− mice had significantly increased trabecular bone volume and showed abnormal osteoclast morphology with defective resorption pit formation. Conclusion PI3Kβ plays an important role in osteoclast development and function and is required for in vivo bone homeostasis.
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Affiliation(s)
- Dávid Győri
- Semmelweis University School of Medicine, and MTA-SE "Lendület" Inflammation Physiology Research Group of the Hungarian Academy of Sciences and Semmelweis University, Budapest, Hungary
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205
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Hosseinzadeh Z, Schmid E, Shumilina E, Laufer S, Borst O, Gawaz M, Lang F. Effect of TGFβ on Na+/K+ ATPase activity in megakaryocytes. Biochem Biophys Res Commun 2014; 452:537-41. [DOI: 10.1016/j.bbrc.2014.08.093] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2014] [Accepted: 08/20/2014] [Indexed: 11/26/2022]
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206
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Joshi S, Singh AR, Zulcic M, Durden DL. A macrophage-dominant PI3K isoform controls hypoxia-induced HIF1α and HIF2α stability and tumor growth, angiogenesis, and metastasis. Mol Cancer Res 2014; 12:1520-31. [PMID: 25103499 DOI: 10.1158/1541-7786.mcr-13-0682] [Citation(s) in RCA: 99] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
UNLABELLED Tumor growth, progression, and response to the hypoxic tumor microenvironment involve the action of hypoxia-inducible transcription factors, HIF1 and HIF2. HIF is a heterodimeric transcription factor containing an inducible HIFα subunit and a constitutively expressed HIFβ subunit. The signaling pathways operational in macrophages regulating hypoxia-induced HIFα stabilization remain the subject of intense investigation. Here, it was discovered that the PTEN/PI3K/AKT signaling axis controls hypoxia-induced HIF1α (HIF1A) and HIF2α (EPAS1) stability in macrophages. Using genetic mouse models and pan-PI3K as well as isoform-specific inhibitors, inhibition of the PI3K/AKT pathway blocked the accumulation of HIFα protein and its primary transcriptional target VEGF in response to hypoxia. Moreover, blocking the PI3K/AKT signaling axis promoted the hypoxic degradation of HIFα via the 26S proteasome. Mechanistically, a macrophage-dominant PI3K isoform (p110γ) directed tumor growth, angiogenesis, metastasis, and the HIFα/VEGF axis. Moreover, a pan-PI3K inhibitor (SF1126) blocked tumor-induced angiogenesis and inhibited VEGF and other proangiogenic factors secreted by macrophages. These data define a novel molecular mechanism by which PTEN/PI3K/AKT regulates the proteasome-dependent stability of HIFα under hypoxic conditions, a signaling pathway in macrophages that controls tumor-induced angiogenesis and metastasis. IMPLICATIONS This study indicates that PI3K inhibitors are excellent candidates for the treatment of cancers where macrophages promote tumor progression.
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Affiliation(s)
- Shweta Joshi
- UCSD Department of Pediatrics, Moores Cancer Center, University of California, La Jolla, California
| | - Alok R Singh
- UCSD Department of Pediatrics, Moores Cancer Center, University of California, La Jolla, California
| | - Muamera Zulcic
- UCSD Department of Pediatrics, Moores Cancer Center, University of California, La Jolla, California
| | - Donald L Durden
- UCSD Department of Pediatrics, Moores Cancer Center, University of California, La Jolla, California. Division of Pediatric Hematology-Oncology, UCSD Rady Children's Hospital, San Diego, California. SignalRx Pharmaceuticals, San Diego, California.
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207
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Giordanetto F, Barlaam B, Berglund S, Edman K, Karlsson O, Lindberg J, Nylander S, Inghardt T. Discovery of 9-(1-phenoxyethyl)-2-morpholino-4-oxo-pyrido[1,2-a]pyrimidine-7-carboxamides as oral PI3Kβ inhibitors, useful as antiplatelet agents. Bioorg Med Chem Lett 2014; 24:3936-43. [DOI: 10.1016/j.bmcl.2014.07.007] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2014] [Revised: 07/01/2014] [Accepted: 07/02/2014] [Indexed: 12/15/2022]
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208
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Discovery of 9-(1-anilinoethyl)-2-morpholino-4-oxo-pyrido[1,2-a]pyrimidine-7-carboxamides as PI3Kβ/δ inhibitors for the treatment of PTEN-deficient tumours. Bioorg Med Chem Lett 2014; 24:3928-35. [DOI: 10.1016/j.bmcl.2014.06.040] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2014] [Revised: 06/11/2014] [Accepted: 06/13/2014] [Indexed: 12/14/2022]
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Joshi S, Singh AR, Durden DL. MDM2 regulates hypoxic hypoxia-inducible factor 1α stability in an E3 ligase, proteasome, and PTEN-phosphatidylinositol 3-kinase-AKT-dependent manner. J Biol Chem 2014; 289:22785-22797. [PMID: 24982421 DOI: 10.1074/jbc.m114.587493] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Hypoxia-inducible factor 1 (HIF1) is a heterodimeric transcription factor containing an inducibly expressed HIF1α subunit and a constitutively expressed HIF1β subunit. Under hypoxic conditions, the HIF1α subunit accumulates because of a decrease in the rate of proteolytic degradation, and the resulting HIF1α-HIF1β heterodimers undergo post-translational modifications that promote transactivation. Previous reports suggest that amplified signaling through PI3K enhances HIF1-dependent gene expression; however, its role is controversial, and the mechanism is unclear. Using genetically engineered PTEN-deficient cell lines, we demonstrate that PTEN specifically inhibited the accumulation of HIF1α in response to hypoxia. Furthermore, we report that in glioblastoma cell lines, inhibition of PI3K pathway, using pan as well as isoform-specific PI3K inhibitors SF1126, PF4691502, BEZ-235, GDC0941, and TGX221 blocked the induction of HIF1α protein and its targets vascular endothelial growth factor, HK1, and GLUT1 mRNA in response to hypoxia. Herein, we describe the first evidence that HIF1α can be degraded under hypoxic conditions via the 26 S proteasome and that MDM2 is the E3 ligase that induces the hypoxic degradation of HIF1α. Moreover, the action of MDM2 on HIF1α under hypoxia occurs in the cytoplasm and is controlled by the PTEN-PI3K-AKT signaling axis. These data strongly suggest a new role for PTEN in the regulation of HIF1α and importantly that PI3K-AKT activation is required for the hypoxic stabilization of HIF1α and that hypoxia alone is not sufficient to render HIF1α resistant to proteasomal cleavage and degradation. Moreover, these findings suggest new therapeutic considerations for PI3K and/or AKT inhibitors for cancer therapeutics.
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Affiliation(s)
- Shweta Joshi
- Department of Pediatrics, Moores Cancer Center, UC San Diego Health System, La Jolla, California 92093 and
| | - Alok R Singh
- Department of Pediatrics, Moores Cancer Center, UC San Diego Health System, La Jolla, California 92093 and
| | - Donald L Durden
- Department of Pediatrics, Moores Cancer Center, UC San Diego Health System, La Jolla, California 92093 and; University of California at San Diego Rady Children's Hospital, San Diego, California 92123.
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210
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Lewerenz J, Baxter P, Kassubek R, Albrecht P, Van Liefferinge J, Westhoff MA, Halatsch ME, Karpel-Massler G, Meakin PJ, Hayes JD, Aronica E, Smolders I, Ludolph AC, Methner A, Conrad M, Massie A, Hardingham GE, Maher P. Phosphoinositide 3-kinases upregulate system xc(-) via eukaryotic initiation factor 2α and activating transcription factor 4 - A pathway active in glioblastomas and epilepsy. Antioxid Redox Signal 2014; 20:2907-22. [PMID: 24219064 PMCID: PMC4038988 DOI: 10.1089/ars.2013.5455] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2013] [Revised: 10/25/2013] [Accepted: 11/12/2013] [Indexed: 01/08/2023]
Abstract
AIMS Phosphoinositide 3-kinases (PI3Ks) relay growth factor signaling and mediate cytoprotection and cell growth. The cystine/glutamate antiporter system xc(-) imports cystine while exporting glutamate, thereby promoting glutathione synthesis while increasing extracellular cerebral glutamate. The aim of this study was to analyze the pathway through which growth factor and PI3K signaling induce the cystine/glutamate antiporter system xc(-) and to demonstrate its biological significance for neuroprotection, cell growth, and epilepsy. RESULTS PI3Ks induce system xc(-) through glycogen synthase kinase 3β (GSK-3β) inhibition, general control non-derepressible-2-mediated eukaryotic initiation factor 2α phosphorylation, and the subsequent translational up-regulation of activating transcription factor 4. This pathway is essential for PI3Ks to modulate oxidative stress resistance of nerve cells and insulin-induced growth in fibroblasts. Moreover, the pathway is active in human glioblastoma cells. In addition, it is induced in primary cortical neurons in response to robust neuronal activity and in hippocampi from patients with temporal lobe epilepsy. INNOVATION Our findings further extend the concepts of how growth factors and PI3Ks induce neuroprotection and cell growth by adding a new branch to the signaling network downstream of GSK-3β, which, ultimately, leads to the induction of the cystine/glutamate antiporter system xc(-). Importantly, the induction of this pathway by neuronal activity and in epileptic hippocampi points to a potential role in epilepsy. CONCLUSION PI3K-regulated system xc(-) activity is not only involved in the stress resistance of neuronal cells and in cell growth by increasing the cysteine supply and glutathione synthesis, but also plays a role in the pathophysiology of tumor- and non-tumor-associated epilepsy by up-regulating extracellular cerebral glutamate.
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Affiliation(s)
- Jan Lewerenz
- Department of Neurology, Ulm University, Ulm, Germany
| | - Paul Baxter
- Center for Integrative Physiology, University of Edinburgh, Edinburgh, Scotland, United Kingdom
| | | | - Philipp Albrecht
- Department of Neurology, Medical Faculty, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
| | - Joeri Van Liefferinge
- Pharmaceutical Chemistry and Drug Analysis, Center for Neurosciences, Vrije Universiteit Brussel, Brussels, Belgium
| | | | | | | | - Paul J. Meakin
- Medical Research Institute, University of Dundee, Ninewells Hospital and Medical School, Dundee, Scotland, United Kingdom
| | - John D. Hayes
- Medical Research Institute, University of Dundee, Ninewells Hospital and Medical School, Dundee, Scotland, United Kingdom
| | - Eleonora Aronica
- Department of (Neuro)Pathology, Academic Medical Center, and Swammerdam Institute for Life Sciences, Center for Neuroscience, University of Amsterdam, Amsterdam, The Netherlands
- SEIN—Stichting Epilepsie Instellingen Nederland, Heemstede, The Netherlands
| | - Ilse Smolders
- Pharmaceutical Chemistry and Drug Analysis, Center for Neurosciences, Vrije Universiteit Brussel, Brussels, Belgium
| | | | - Axel Methner
- Focus Program Translational Neuroscience (FTN), Rhine Main Neuroscience Network (rmn), Department of Neurology, Johannes Gutenberg University Medical Center Mainz, Mainz, Germany
| | - Marcus Conrad
- Institute of Developmental Genetics, Helmholtz Zentrum München, Neuherberg, Germany
| | - Ann Massie
- Pharmaceutical Biotechnology and Molecular Biology, Center for Neurosciences, Vrije Universiteit Brussel, Brussels, Belgium
| | - Giles E. Hardingham
- Center for Integrative Physiology, University of Edinburgh, Edinburgh, Scotland, United Kingdom
| | - Pamela Maher
- Cellular Neurobiology Laboratory, Salk Institute for Biological Studies, La Jolla, California
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211
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Effects of novel isoform-selective phosphoinositide 3-kinase inhibitors on natural killer cell function. PLoS One 2014; 9:e99486. [PMID: 24915189 PMCID: PMC4051752 DOI: 10.1371/journal.pone.0099486] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2013] [Accepted: 05/15/2014] [Indexed: 01/23/2023] Open
Abstract
Phosphoinositide 3-kinases (PI3Ks) are promising targets for therapeutic development in cancer. The class I PI3K isoform p110α has received considerable attention in oncology because the gene encoding p110α (PIK3CA) is frequently mutated in human cancer. However, little is known about the function of p110α in lymphocyte populations that modulate tumorigenesis. We used recently developed investigational inhibitors to compare the function of p110α and other isoforms in natural killer (NK) cells, a key cell type for immunosurveillance and tumor immunotherapy. Inhibitors of all class I isoforms (pan-PI3K) significantly impaired NK cell-mediated cytotoxicity and antibody-dependent cellular cytotoxicity against tumor cells, whereas p110α-selective inhibitors had no effect. In NK cells stimulated through NKG2D, p110α inhibition modestly reduced PI3K signaling output as measured by AKT phosphorylation. Production of IFN-γ and NK cell-derived chemokines was blocked by a pan-PI3K inhibitor and partially reduced by a p110δinhibitor, with lesser effects of p110α inhibitors. Oral administration of mice with MLN1117, a p110α inhibitor in oncology clinical trials, had negligible effects on NK subset maturation or terminal subset commitment. Collectively, these results support the targeting of PIK3CA mutant tumors with selective p110α inhibitors to preserve NK cell function.
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212
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Blair TA, Moore SF, Williams CM, Poole AW, Vanhaesebroeck B, Hers I. Phosphoinositide 3-kinases p110α and p110β have differential roles in insulin-like growth factor-1-mediated Akt phosphorylation and platelet priming. Arterioscler Thromb Vasc Biol 2014; 34:1681-8. [PMID: 24903091 DOI: 10.1161/atvbaha.114.303954] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
OBJECTIVE Platelet hyperactivity is a contributing factor in the pathogenesis of cardiovascular disease and can be induced by elevated levels of circulating growth factors, such as insulin-like growth factor-1 (IGF-1). IGF-1 is a primer that cannot stimulate platelet activation by itself, but in combination with physiological stimuli can potentiate platelet functional responses via a phosphoinositide 3-kinase-dependent mechanism. In this study, we explored the role of the phosphoinositide 3-kinase p110α isoform in IGF-1-mediated enhancement of platelet function. APPROACH AND RESULTS Using a platelet-specific p110α knockout murine model, we demonstrate that genetic deletion, similar to pharmacological inactivation of p110α, did not affect proteinase-activated receptor 4 signaling to Akt/protein kinase B but significantly reduced IGF-1-mediated Akt phosphorylation. The p110β inhibitor TGX-221 abolished IGF-1-induced Akt phosphorylation in p110α-deficient platelets, demonstrating that both p110α and p110β contribute to IGF-1-mediated Akt phosphorylation. Genetic deletion of p110α had no effect on IGF-1-mediated increases in thrombus formation on collagen and enhancement of proteinase-activated receptor 4-mediated integrin activation and α-granule secretion. In contrast, pharmacological inhibition of p110α blocked IGF-1-mediated potentiation of integrin activation and α-granule secretion. Functional enhancement by IGF-1 in p110α knockout samples was lost after TGX-221 treatment, suggesting that p110β drives priming in the absence of the p110α isoform. CONCLUSIONS Together, these results demonstrate that both p110α and p110β are involved in Akt signaling by IGF-1, but that it is the p110α isoform that is responsible for IGF-1-mediated potentiation of platelet function.
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Affiliation(s)
- Thomas A Blair
- From the School of Physiology and Pharmacology, University of Bristol, Bristol, United Kingdom (T.A.B., S.F.M., C.M.W., A.W.P., I.H.); and Research Department of Oncology, UCL Cancer Institute, University College London, London, United Kingdom (B.V.)
| | - Samantha F Moore
- From the School of Physiology and Pharmacology, University of Bristol, Bristol, United Kingdom (T.A.B., S.F.M., C.M.W., A.W.P., I.H.); and Research Department of Oncology, UCL Cancer Institute, University College London, London, United Kingdom (B.V.)
| | - Christopher M Williams
- From the School of Physiology and Pharmacology, University of Bristol, Bristol, United Kingdom (T.A.B., S.F.M., C.M.W., A.W.P., I.H.); and Research Department of Oncology, UCL Cancer Institute, University College London, London, United Kingdom (B.V.)
| | - Alastair W Poole
- From the School of Physiology and Pharmacology, University of Bristol, Bristol, United Kingdom (T.A.B., S.F.M., C.M.W., A.W.P., I.H.); and Research Department of Oncology, UCL Cancer Institute, University College London, London, United Kingdom (B.V.)
| | - Bart Vanhaesebroeck
- From the School of Physiology and Pharmacology, University of Bristol, Bristol, United Kingdom (T.A.B., S.F.M., C.M.W., A.W.P., I.H.); and Research Department of Oncology, UCL Cancer Institute, University College London, London, United Kingdom (B.V.)
| | - Ingeborg Hers
- From the School of Physiology and Pharmacology, University of Bristol, Bristol, United Kingdom (T.A.B., S.F.M., C.M.W., A.W.P., I.H.); and Research Department of Oncology, UCL Cancer Institute, University College London, London, United Kingdom (B.V.).
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213
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Larive RM, Moriggi G, Menacho-Márquez M, Cañamero M, de Álava E, Alarcón B, Dosil M, Bustelo XR. Contribution of the R-Ras2 GTP-binding protein to primary breast tumorigenesis and late-stage metastatic disease. Nat Commun 2014; 5:3881. [PMID: 24826867 DOI: 10.1038/ncomms4881] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2014] [Accepted: 04/14/2014] [Indexed: 02/07/2023] Open
Abstract
R-Ras2 is a transforming GTPase that shares downstream effectors with Ras subfamily proteins. However, little information exists about the function of this protein in tumorigenesis and its signalling overlap with classical Ras GTPases. Here we show, by combining loss- and gain-of-function studies in breast cancer cells, mammary epithelial cells and mouse models, that endogenous R-Ras2 has a role in both primary breast tumorigenesis and the late metastatic steps of cancer cells in the lung parenchyma. R-Ras2 drives tumorigenesis in a phosphatidylinostiol-3 kinase (PI3K)-dependent and signalling autonomous manner. By contrast, its prometastatic role requires other priming oncogenic signals and the engagement of several downstream elements. R-Ras2 function is required even in cancer cells exhibiting constitutive activation of classical Ras proteins, indicating that these GTPases are not functionally redundant. Our results also suggest that application of long-term R-Ras2 therapies will result in the development of compensatory mechanisms in breast tumours.
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Affiliation(s)
- Romain M Larive
- 1] Centro de Investigación del Cáncer, Consejo Superior de Investigaciones Científicas (CSIC)-University of Salamanca, Campus Unamuno s/n, 37007 Salamanca, Spain [2] Instituto de Biología Molecular y Celular del Cáncer, Consejo Superior de Investigaciones Científicas (CSIC)-University of Salamanca, Campus Unamuno s/n, 37007 Salamanca, Spain [3]
| | - Giulia Moriggi
- 1] Centro de Investigación del Cáncer, Consejo Superior de Investigaciones Científicas (CSIC)-University of Salamanca, Campus Unamuno s/n, 37007 Salamanca, Spain [2] Instituto de Biología Molecular y Celular del Cáncer, Consejo Superior de Investigaciones Científicas (CSIC)-University of Salamanca, Campus Unamuno s/n, 37007 Salamanca, Spain
| | - Mauricio Menacho-Márquez
- 1] Centro de Investigación del Cáncer, Consejo Superior de Investigaciones Científicas (CSIC)-University of Salamanca, Campus Unamuno s/n, 37007 Salamanca, Spain [2] Instituto de Biología Molecular y Celular del Cáncer, Consejo Superior de Investigaciones Científicas (CSIC)-University of Salamanca, Campus Unamuno s/n, 37007 Salamanca, Spain
| | - Marta Cañamero
- Centro Nacional de Investigaciones Oncológicas (CNIO), 3 Fernández Almagro Street, 28029 Madrid, Spain
| | - Enrique de Álava
- 1] Centro de Investigación del Cáncer, Consejo Superior de Investigaciones Científicas (CSIC)-University of Salamanca, Campus Unamuno s/n, 37007 Salamanca, Spain [2] Instituto de Biología Molecular y Celular del Cáncer, Consejo Superior de Investigaciones Científicas (CSIC)-University of Salamanca, Campus Unamuno s/n, 37007 Salamanca, Spain [3] Hospital Universitario Virgen del Rocío, Manuel Suriot Avenue, 41013 Sevilla, Spain
| | - Balbino Alarcón
- Centro de Biología Molecular "Severo Ochoa", CSIC-Madrid Autonomous University, 1 Nicolás Cabrera Street, 28049 Madrid, Spain
| | - Mercedes Dosil
- 1] Centro de Investigación del Cáncer, Consejo Superior de Investigaciones Científicas (CSIC)-University of Salamanca, Campus Unamuno s/n, 37007 Salamanca, Spain [2] Instituto de Biología Molecular y Celular del Cáncer, Consejo Superior de Investigaciones Científicas (CSIC)-University of Salamanca, Campus Unamuno s/n, 37007 Salamanca, Spain [3] Departamento de Bioquímica y Biología Molecular, University of Salamanca, Campus Unamuno s/n, 37007 Salamanca, Spain
| | - Xosé R Bustelo
- 1] Centro de Investigación del Cáncer, Consejo Superior de Investigaciones Científicas (CSIC)-University of Salamanca, Campus Unamuno s/n, 37007 Salamanca, Spain [2] Instituto de Biología Molecular y Celular del Cáncer, Consejo Superior de Investigaciones Científicas (CSIC)-University of Salamanca, Campus Unamuno s/n, 37007 Salamanca, Spain
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Nehmé R, Nehmé H, Saurat T, de-Tauzia ML, Buron F, Lafite P, Verrelle P, Chautard E, Morin P, Routier S, Bénédetti H. New in-capillary electrophoretic kinase assays to evaluate inhibitors of the PI3k/Akt/mTOR signaling pathway. Anal Bioanal Chem 2014; 406:3743-54. [PMID: 24817345 DOI: 10.1007/s00216-014-7790-z] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2014] [Accepted: 03/24/2014] [Indexed: 01/15/2023]
Abstract
Human kinases are one of the most promising targets for cancer therapy. Methods able to measure the effects of drugs on these cell agents remain crucial for biologists and medicinal chemists. The current work therefore sought to develop an in-capillary enzymatic assay based on capillary electrophoresis (CE) to evaluate the inhibition of phosphatidylinositol-3-kinase (PI3K), protein kinase B (Akt), and the mammalian target of rapamycin (mTOR). These kinases belong to the same signaling pathway PI3K/Akt/mTOR. For this proposal, the capillary was used as a nanoreactor in which a few nanoliters of the kinase, its substrate, adenosine triphosphate (ATP), and the potent inhibitor were separately injected. A transverse diffusion of laminar flow profiles (TDLFP) approach was employed to mix the reactants. Adenosine diphosphate (ADP ) was detected online at 254 nm. The CE assay was first developed on the α isoform of PI3K. It was compared to five commercial kits frequently used to assess kinase inhibition, based on time-resolved fluorescence resonance energy transfer (TR-FRET) and bioluminescence. Each assay was evaluated in terms of sensitivity (S/B), reproducibility (Z'), and variability (r (2)). This CE method was easily extended to assay the inhibition of the β, γ, and δ isoforms of PI3K, and of the other kinases of the pathway, Akt1 and mTOR, since it is based on in-capillary mixing by TDLFP and on ADP quantification by simple UV absorption. This work shows for the first time the evaluation of inhibitors of the kinases of the PI3K/Akt/mTOR pathway using a common in-capillary CE assay. Several inhibitors with a wide range of affinity toward these enzymes were tested.
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Affiliation(s)
- Reine Nehmé
- Institut de Chimie Organique et Analytique (ICOA), CNRS FR 2708, UMR 7311, Université d'Orléans, Orléans, France,
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Abstract
Class I PI3Ks are composed of four catalytic subunit variants (p110α, p110β, p110δ and p110γ). The PI3K pathway is among the most frequently activated pathways in many diseases, and has emerged as an attractive target for drug development, in particular for the treatment of many human cancers including breast, prostate, ovarian, gastric, colon and hepatocellular cancers. One of the challenges in the discovery of drugs that target kinases is designing small-molecule inhibitors that are sufficiently selective to minimize off-target activity and reduce the risk of potential toxicity. This review explores the current landscape of PI3K-selective inhibitor development and highlights recent advances in achieving selectivity for PI3Ks over other protein kinases, with an emphasis on available structural information.
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216
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Höland K, Boller D, Hagel C, Dolski S, Treszl A, Pardo OE, Ćwiek P, Salm F, Leni Z, Shepherd PR, Styp-Rekowska B, Djonov V, von Bueren AO, Frei K, Arcaro A. Targeting class IA PI3K isoforms selectively impairs cell growth, survival, and migration in glioblastoma. PLoS One 2014; 9:e94132. [PMID: 24718026 PMCID: PMC3981776 DOI: 10.1371/journal.pone.0094132] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2013] [Accepted: 03/13/2014] [Indexed: 12/13/2022] Open
Abstract
The phosphoinositide 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) pathway is frequently activated in human cancer and plays a crucial role in glioblastoma biology. We were interested in gaining further insight into the potential of targeting PI3K isoforms as a novel anti-tumor approach in glioblastoma. Consistent expression of the PI3K catalytic isoform PI3K p110α was detected in a panel of glioblastoma patient samples. In contrast, PI3K p110β expression was only rarely detected in glioblastoma patient samples. The expression of a module comprising the epidermal growth factor receptor (EGFR)/PI3K p110α/phosphorylated ribosomal S6 protein (p-S6) was correlated with shorter patient survival. Inhibition of PI3K p110α activity impaired the anchorage-dependent growth of glioblastoma cells and induced tumor regression in vivo. Inhibition of PI3K p110α or PI3K p110β also led to impaired anchorage-independent growth, a decreased migratory capacity of glioblastoma cells, and reduced the activation of the Akt/mTOR pathway. These effects were selective, because targeting of PI3K p110δ did not result in a comparable impairment of glioblastoma tumorigenic properties. Together, our data reveal that drugs targeting PI3K p110α can reduce growth in a subset of glioblastoma tumors characterized by the expression of EGFR/PI3K p110α/p-S6.
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Affiliation(s)
- Katrin Höland
- Department of Clinical Research, University of Bern, Bern, Switzerland
| | - Danielle Boller
- Division of Clinical Chemistry and Biochemistry, University Children’s Hospital Zurich, Zurich, Switzerland
| | - Christian Hagel
- Institute of Neuropathology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Silvia Dolski
- Department of Neurosurgery, University Hospital Zurich, Zurich, Switzerland
| | - András Treszl
- Department of Medical Biometry and Epidemiology, Center for Experimental Medicine, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Olivier E. Pardo
- Department of Surgery and Cancer, Imperial College London, London, United Kingdom
| | - Paulina Ćwiek
- Department of Clinical Research, University of Bern, Bern, Switzerland
| | - Fabiana Salm
- Department of Clinical Research, University of Bern, Bern, Switzerland
| | - Zaira Leni
- Department of Clinical Research, University of Bern, Bern, Switzerland
| | - Peter R. Shepherd
- Department of Molecular Medicine and Pathology, University of Auckland, Auckland, New Zealand
| | | | | | - André O. von Bueren
- Division of Pediatric Hematology and Oncology, Department of Pediatrics and Adolescent Medicine, University Medical Center Goettingen, Goettingen, Germany
| | - Karl Frei
- Department of Neurosurgery, University Hospital Zurich, Zurich, Switzerland
| | - Alexandre Arcaro
- Department of Clinical Research, University of Bern, Bern, Switzerland
- Division of Clinical Chemistry and Biochemistry, University Children’s Hospital Zurich, Zurich, Switzerland
- * E-mail:
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217
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O'Donnell VB, Murphy RC, Watson SP. Platelet lipidomics: modern day perspective on lipid discovery and characterization in platelets. Circ Res 2014; 114:1185-203. [PMID: 24677238 PMCID: PMC4021279 DOI: 10.1161/circresaha.114.301597] [Citation(s) in RCA: 110] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Lipids are diverse families of biomolecules that perform essential structural and signaling roles in platelets. Their formation and metabolism are tightly controlled by enzymes and signal transduction pathways, and their dysregulation leads to significant defects in platelet function and disease. Platelet activation is associated with significant changes to membrane lipids, and formation of diverse bioactive lipids plays essential roles in hemostasis. In recent years, new generation mass spectrometry analysis of lipids (termed lipidomics) has begun to alter our understanding of how these molecules participate in key cellular processes. Although the application of lipidomics to platelet biology is still in its infancy, seminal earlier studies have shaped our knowledge of how lipids regulate key aspects of platelet biology, including aggregation, shape change, coagulation, and degranulation, as well as how lipids generated by platelets influence other cells, such as leukocytes and the vascular wall, and thus how they regulate hemostasis, vascular integrity, and inflammation, as well as contribute to pathologies, including arterial/deep vein thrombosis and atherosclerosis. This review will provide a brief historical perspective on the characterization of lipids in platelets, then an overview of the new generation lipidomic approaches, their recent application to platelet biology, and future perspectives for research in this area. The major platelet-regulatory lipid families, their formation, metabolism, and their role in health and disease, will be summarized.
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Affiliation(s)
- Valerie B O'Donnell
- From the Institute of Infection and Immunity, School of Medicine, Cardiff University, Cardiff, United Kingdom (V.B.O'D.); Department of Pharmacology, University of Colorado at Denver, Aurora (R.C.M.); and Birmingham Platelet Group, Centre for Cardiovascular Sciences, Institute of Biomedical Research, College of Medical and Dental Sciences, Birmingham, United Kingdom (S.P.W.)
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218
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Bai T, Yang Y, Wu YL, Jiang S, Lee JJ, Lian LH, Nan JX. Thymoquinone alleviates thioacetamide-induced hepatic fibrosis and inflammation by activating LKB1-AMPK signaling pathway in mice. Int Immunopharmacol 2014; 19:351-7. [PMID: 24560906 DOI: 10.1016/j.intimp.2014.02.006] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2013] [Revised: 02/03/2014] [Accepted: 02/05/2014] [Indexed: 02/07/2023]
Abstract
The current study was conducted to investigate the anti-fibrotic effect and its possible underlying mechanisms of thymoquinone (TQ) against hepatic fibrosis in vivo. TQ is the major active compound derived from the medicinal Nigella sativa. Liver fibrosis was induced in male Kunming mice by intraperitoneal injections of thioacetamide (TAA, 200 mg/kg). Mice were treated concurrently with TAA alone or TAA plus TQ (20 mg/kg or 40 mg/kg) given daily by oral gavage. Our data demonstrated that TQ treatment obviously reversed liver tissue damage compared with TAA alone group, characterized by less inflammatory infiltration and accumulation of extracellular matrix (ECM) proteins. TQ significantly attenuated TAA-induced liver fibrosis, accompanied by reduced protein and mRNA expression of α-smooth muscle actin (α-SMA), collagen-І and tissue inhibitor of metalloproteinase-1 (TIMP-1). TQ downregulated the expression of toll-like receptor 4 (TLR4) and remarkably decreased proinflammatory cytokine levels as well. TQ also significantly inhibited phosphatidylinositol 3-kinase (PI3K) phosphorylation. Furthermore, TQ enhanced the phosphorylation adenosine monophosphate-activated protein kinase (AMPK) and liver kinase B (LKB)-1. In conclusion, TQ may reduce ECM accumulation, and it may be at least regulated by phosphorylation of AMPK signaling pathways, suggesting that TQ may be a potential candidate for the therapy of hepatic fibrosis.
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Affiliation(s)
- Ting Bai
- Key Laboratory for Natural Resource of Changbai Mountain & Functional Molecules, Ministry of Education, College of Pharmacy, Yanbian University, Yanji 133002, Jilin Province, China
| | - Yong Yang
- Key Laboratory for Natural Resource of Changbai Mountain & Functional Molecules, Ministry of Education, College of Pharmacy, Yanbian University, Yanji 133002, Jilin Province, China
| | - Yan-Ling Wu
- Key Laboratory for Natural Resource of Changbai Mountain & Functional Molecules, Ministry of Education, College of Pharmacy, Yanbian University, Yanji 133002, Jilin Province, China
| | - Shuang Jiang
- Key Laboratory for Natural Resource of Changbai Mountain & Functional Molecules, Ministry of Education, College of Pharmacy, Yanbian University, Yanji 133002, Jilin Province, China
| | - Jung Joon Lee
- Key Laboratory for Natural Resource of Changbai Mountain & Functional Molecules, Ministry of Education, College of Pharmacy, Yanbian University, Yanji 133002, Jilin Province, China
| | - Li-Hua Lian
- Key Laboratory for Natural Resource of Changbai Mountain & Functional Molecules, Ministry of Education, College of Pharmacy, Yanbian University, Yanji 133002, Jilin Province, China.
| | - Ji-Xing Nan
- Key Laboratory for Natural Resource of Changbai Mountain & Functional Molecules, Ministry of Education, College of Pharmacy, Yanbian University, Yanji 133002, Jilin Province, China.
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219
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Saurat T, Buron F, Rodrigues N, de Tauzia ML, Colliandre L, Bourg S, Bonnet P, Guillaumet G, Akssira M, Corlu A, Guillouzo C, Berthier P, Rio P, Jourdan ML, Bénédetti H, Routier S. Design, Synthesis, and Biological Activity of Pyridopyrimidine Scaffolds as Novel PI3K/mTOR Dual Inhibitors. J Med Chem 2014; 57:613-31. [DOI: 10.1021/jm401138v] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Thibault Saurat
- Institut
de Chimie Organique et Analytique, Université d’Orléans, UMR CNRS 7311, Rue de Chartres, BP 6759, 45067 OrléansCedex
2, France
- Centre de Biophysique Moléculaire, CNRS Orléans, Rue Charles Sadron, 45071 Orléans, France
| | - Frédéric Buron
- Institut
de Chimie Organique et Analytique, Université d’Orléans, UMR CNRS 7311, Rue de Chartres, BP 6759, 45067 OrléansCedex
2, France
| | - Nuno Rodrigues
- Institut
de Chimie Organique et Analytique, Université d’Orléans, UMR CNRS 7311, Rue de Chartres, BP 6759, 45067 OrléansCedex
2, France
| | | | - Lionel Colliandre
- Institut
de Chimie Organique et Analytique, Université d’Orléans, UMR CNRS 7311, Rue de Chartres, BP 6759, 45067 OrléansCedex
2, France
| | - Stéphane Bourg
- Institut
de Chimie Organique et Analytique, Université d’Orléans, UMR CNRS 7311, Rue de Chartres, BP 6759, 45067 OrléansCedex
2, France
- Centre de Biophysique Moléculaire, CNRS Orléans, Rue Charles Sadron, 45071 Orléans, France
| | - Pascal Bonnet
- Institut
de Chimie Organique et Analytique, Université d’Orléans, UMR CNRS 7311, Rue de Chartres, BP 6759, 45067 OrléansCedex
2, France
| | - Gérald Guillaumet
- Institut
de Chimie Organique et Analytique, Université d’Orléans, UMR CNRS 7311, Rue de Chartres, BP 6759, 45067 OrléansCedex
2, France
| | - Mohamed Akssira
- Équipe de Chimie Bioorganique & Analytique, URAC 22, Université Hassan II Mohammedia-Casablanca, BP 146, 28800 Mohammedia, Morocco
| | - Anne Corlu
- Hôpital
de Pontchaillou, Université de Rennes 1, INSERM, UMR-991, 65033 Rennes Cedex, France
| | - Christiane Guillouzo
- Hôpital
de Pontchaillou, Université de Rennes 1, INSERM, UMR-991, 65033 Rennes Cedex, France
| | - Pauline Berthier
- Faculté
de Médecine, Centre Hospitalier Universitaire (CHU) Tours, INSERM U1069, 10 Boulevard Tonnellé, 37032 Tours Cedex, France
| | - Pascale Rio
- Faculté
de Médecine, Centre Hospitalier Universitaire (CHU) Tours, INSERM U1069, 10 Boulevard Tonnellé, 37032 Tours Cedex, France
| | - Marie-Lise Jourdan
- Faculté
de Médecine, Centre Hospitalier Universitaire (CHU) Tours, INSERM U1069, 10 Boulevard Tonnellé, 37032 Tours Cedex, France
| | - Hélène Bénédetti
- Centre de Biophysique Moléculaire, CNRS Orléans, Rue Charles Sadron, 45071 Orléans, France
| | - Sylvain Routier
- Institut
de Chimie Organique et Analytique, Université d’Orléans, UMR CNRS 7311, Rue de Chartres, BP 6759, 45067 OrléansCedex
2, France
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220
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Certal V, Carry JC, Halley F, Virone-Oddos A, Thompson F, Filoche-Rommé B, El-Ahmad Y, Karlsson A, Charrier V, Delorme C, Rak A, Abecassis PY, Amara C, Vincent L, Bonnevaux H, Nicolas JP, Mathieu M, Bertrand T, Marquette JP, Michot N, Benard T, Perrin MA, Lemaitre O, Guerif S, Perron S, Monget S, Gruss-Leleu F, Doerflinger G, Guizani H, Brollo M, Delbarre L, Bertin L, Richepin P, Loyau V, Garcia-Echeverria C, Lengauer C, Schio L. Discovery and Optimization of Pyrimidone Indoline Amide PI3Kβ Inhibitors for the Treatment of Phosphatase and Tensin Homologue (PTEN)-Deficient Cancers. J Med Chem 2014; 57:903-20. [DOI: 10.1021/jm401642q] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Victor Certal
- Oncology Drug Discovery, §Structure Design Informatics,
and Structural Biology, #Drug Disposition and Safety (DSAR), †Protein Production,⊥Pharmaceutical Sciences, ∥Analytical Sciences, Sanofi, 13, quai Jules Guesde, 94403 Vitry-sur-Seine, France
| | - Jean-Christophe Carry
- Oncology Drug Discovery, §Structure Design Informatics,
and Structural Biology, #Drug Disposition and Safety (DSAR), †Protein Production,⊥Pharmaceutical Sciences, ∥Analytical Sciences, Sanofi, 13, quai Jules Guesde, 94403 Vitry-sur-Seine, France
| | - Frank Halley
- Oncology Drug Discovery, §Structure Design Informatics,
and Structural Biology, #Drug Disposition and Safety (DSAR), †Protein Production,⊥Pharmaceutical Sciences, ∥Analytical Sciences, Sanofi, 13, quai Jules Guesde, 94403 Vitry-sur-Seine, France
| | - Angela Virone-Oddos
- Oncology Drug Discovery, §Structure Design Informatics,
and Structural Biology, #Drug Disposition and Safety (DSAR), †Protein Production,⊥Pharmaceutical Sciences, ∥Analytical Sciences, Sanofi, 13, quai Jules Guesde, 94403 Vitry-sur-Seine, France
| | - Fabienne Thompson
- Oncology Drug Discovery, §Structure Design Informatics,
and Structural Biology, #Drug Disposition and Safety (DSAR), †Protein Production,⊥Pharmaceutical Sciences, ∥Analytical Sciences, Sanofi, 13, quai Jules Guesde, 94403 Vitry-sur-Seine, France
| | - Bruno Filoche-Rommé
- Oncology Drug Discovery, §Structure Design Informatics,
and Structural Biology, #Drug Disposition and Safety (DSAR), †Protein Production,⊥Pharmaceutical Sciences, ∥Analytical Sciences, Sanofi, 13, quai Jules Guesde, 94403 Vitry-sur-Seine, France
| | - Youssef El-Ahmad
- Oncology Drug Discovery, §Structure Design Informatics,
and Structural Biology, #Drug Disposition and Safety (DSAR), †Protein Production,⊥Pharmaceutical Sciences, ∥Analytical Sciences, Sanofi, 13, quai Jules Guesde, 94403 Vitry-sur-Seine, France
| | - Andreas Karlsson
- Oncology Drug Discovery, §Structure Design Informatics,
and Structural Biology, #Drug Disposition and Safety (DSAR), †Protein Production,⊥Pharmaceutical Sciences, ∥Analytical Sciences, Sanofi, 13, quai Jules Guesde, 94403 Vitry-sur-Seine, France
| | - Véronique Charrier
- Oncology Drug Discovery, §Structure Design Informatics,
and Structural Biology, #Drug Disposition and Safety (DSAR), †Protein Production,⊥Pharmaceutical Sciences, ∥Analytical Sciences, Sanofi, 13, quai Jules Guesde, 94403 Vitry-sur-Seine, France
| | - Cécile Delorme
- Oncology Drug Discovery, §Structure Design Informatics,
and Structural Biology, #Drug Disposition and Safety (DSAR), †Protein Production,⊥Pharmaceutical Sciences, ∥Analytical Sciences, Sanofi, 13, quai Jules Guesde, 94403 Vitry-sur-Seine, France
| | - Alexey Rak
- Oncology Drug Discovery, §Structure Design Informatics,
and Structural Biology, #Drug Disposition and Safety (DSAR), †Protein Production,⊥Pharmaceutical Sciences, ∥Analytical Sciences, Sanofi, 13, quai Jules Guesde, 94403 Vitry-sur-Seine, France
| | - Pierre-Yves Abecassis
- Oncology Drug Discovery, §Structure Design Informatics,
and Structural Biology, #Drug Disposition and Safety (DSAR), †Protein Production,⊥Pharmaceutical Sciences, ∥Analytical Sciences, Sanofi, 13, quai Jules Guesde, 94403 Vitry-sur-Seine, France
| | - Céline Amara
- Oncology Drug Discovery, §Structure Design Informatics,
and Structural Biology, #Drug Disposition and Safety (DSAR), †Protein Production,⊥Pharmaceutical Sciences, ∥Analytical Sciences, Sanofi, 13, quai Jules Guesde, 94403 Vitry-sur-Seine, France
| | - Loïc Vincent
- Oncology Drug Discovery, §Structure Design Informatics,
and Structural Biology, #Drug Disposition and Safety (DSAR), †Protein Production,⊥Pharmaceutical Sciences, ∥Analytical Sciences, Sanofi, 13, quai Jules Guesde, 94403 Vitry-sur-Seine, France
| | - Hélène Bonnevaux
- Oncology Drug Discovery, §Structure Design Informatics,
and Structural Biology, #Drug Disposition and Safety (DSAR), †Protein Production,⊥Pharmaceutical Sciences, ∥Analytical Sciences, Sanofi, 13, quai Jules Guesde, 94403 Vitry-sur-Seine, France
| | - Jean-Paul Nicolas
- Oncology Drug Discovery, §Structure Design Informatics,
and Structural Biology, #Drug Disposition and Safety (DSAR), †Protein Production,⊥Pharmaceutical Sciences, ∥Analytical Sciences, Sanofi, 13, quai Jules Guesde, 94403 Vitry-sur-Seine, France
| | - Magali Mathieu
- Oncology Drug Discovery, §Structure Design Informatics,
and Structural Biology, #Drug Disposition and Safety (DSAR), †Protein Production,⊥Pharmaceutical Sciences, ∥Analytical Sciences, Sanofi, 13, quai Jules Guesde, 94403 Vitry-sur-Seine, France
| | - Thomas Bertrand
- Oncology Drug Discovery, §Structure Design Informatics,
and Structural Biology, #Drug Disposition and Safety (DSAR), †Protein Production,⊥Pharmaceutical Sciences, ∥Analytical Sciences, Sanofi, 13, quai Jules Guesde, 94403 Vitry-sur-Seine, France
| | - Jean-Pierre Marquette
- Oncology Drug Discovery, §Structure Design Informatics,
and Structural Biology, #Drug Disposition and Safety (DSAR), †Protein Production,⊥Pharmaceutical Sciences, ∥Analytical Sciences, Sanofi, 13, quai Jules Guesde, 94403 Vitry-sur-Seine, France
| | - Nadine Michot
- Oncology Drug Discovery, §Structure Design Informatics,
and Structural Biology, #Drug Disposition and Safety (DSAR), †Protein Production,⊥Pharmaceutical Sciences, ∥Analytical Sciences, Sanofi, 13, quai Jules Guesde, 94403 Vitry-sur-Seine, France
| | - Tsiala Benard
- Oncology Drug Discovery, §Structure Design Informatics,
and Structural Biology, #Drug Disposition and Safety (DSAR), †Protein Production,⊥Pharmaceutical Sciences, ∥Analytical Sciences, Sanofi, 13, quai Jules Guesde, 94403 Vitry-sur-Seine, France
| | - Marc-Antoine Perrin
- Oncology Drug Discovery, §Structure Design Informatics,
and Structural Biology, #Drug Disposition and Safety (DSAR), †Protein Production,⊥Pharmaceutical Sciences, ∥Analytical Sciences, Sanofi, 13, quai Jules Guesde, 94403 Vitry-sur-Seine, France
| | - Olivier Lemaitre
- Oncology Drug Discovery, §Structure Design Informatics,
and Structural Biology, #Drug Disposition and Safety (DSAR), †Protein Production,⊥Pharmaceutical Sciences, ∥Analytical Sciences, Sanofi, 13, quai Jules Guesde, 94403 Vitry-sur-Seine, France
| | - Stephane Guerif
- Oncology Drug Discovery, §Structure Design Informatics,
and Structural Biology, #Drug Disposition and Safety (DSAR), †Protein Production,⊥Pharmaceutical Sciences, ∥Analytical Sciences, Sanofi, 13, quai Jules Guesde, 94403 Vitry-sur-Seine, France
| | - Sébastien Perron
- Oncology Drug Discovery, §Structure Design Informatics,
and Structural Biology, #Drug Disposition and Safety (DSAR), †Protein Production,⊥Pharmaceutical Sciences, ∥Analytical Sciences, Sanofi, 13, quai Jules Guesde, 94403 Vitry-sur-Seine, France
| | - Sylvie Monget
- Oncology Drug Discovery, §Structure Design Informatics,
and Structural Biology, #Drug Disposition and Safety (DSAR), †Protein Production,⊥Pharmaceutical Sciences, ∥Analytical Sciences, Sanofi, 13, quai Jules Guesde, 94403 Vitry-sur-Seine, France
| | - Florence Gruss-Leleu
- Oncology Drug Discovery, §Structure Design Informatics,
and Structural Biology, #Drug Disposition and Safety (DSAR), †Protein Production,⊥Pharmaceutical Sciences, ∥Analytical Sciences, Sanofi, 13, quai Jules Guesde, 94403 Vitry-sur-Seine, France
| | - Gilles Doerflinger
- Oncology Drug Discovery, §Structure Design Informatics,
and Structural Biology, #Drug Disposition and Safety (DSAR), †Protein Production,⊥Pharmaceutical Sciences, ∥Analytical Sciences, Sanofi, 13, quai Jules Guesde, 94403 Vitry-sur-Seine, France
| | - Houlfa Guizani
- Oncology Drug Discovery, §Structure Design Informatics,
and Structural Biology, #Drug Disposition and Safety (DSAR), †Protein Production,⊥Pharmaceutical Sciences, ∥Analytical Sciences, Sanofi, 13, quai Jules Guesde, 94403 Vitry-sur-Seine, France
| | - Maurice Brollo
- Oncology Drug Discovery, §Structure Design Informatics,
and Structural Biology, #Drug Disposition and Safety (DSAR), †Protein Production,⊥Pharmaceutical Sciences, ∥Analytical Sciences, Sanofi, 13, quai Jules Guesde, 94403 Vitry-sur-Seine, France
| | - Laurence Delbarre
- Oncology Drug Discovery, §Structure Design Informatics,
and Structural Biology, #Drug Disposition and Safety (DSAR), †Protein Production,⊥Pharmaceutical Sciences, ∥Analytical Sciences, Sanofi, 13, quai Jules Guesde, 94403 Vitry-sur-Seine, France
| | - Luc Bertin
- Oncology Drug Discovery, §Structure Design Informatics,
and Structural Biology, #Drug Disposition and Safety (DSAR), †Protein Production,⊥Pharmaceutical Sciences, ∥Analytical Sciences, Sanofi, 13, quai Jules Guesde, 94403 Vitry-sur-Seine, France
| | - Patrick Richepin
- Oncology Drug Discovery, §Structure Design Informatics,
and Structural Biology, #Drug Disposition and Safety (DSAR), †Protein Production,⊥Pharmaceutical Sciences, ∥Analytical Sciences, Sanofi, 13, quai Jules Guesde, 94403 Vitry-sur-Seine, France
| | - Véronique Loyau
- Oncology Drug Discovery, §Structure Design Informatics,
and Structural Biology, #Drug Disposition and Safety (DSAR), †Protein Production,⊥Pharmaceutical Sciences, ∥Analytical Sciences, Sanofi, 13, quai Jules Guesde, 94403 Vitry-sur-Seine, France
| | - Carlos Garcia-Echeverria
- Oncology Drug Discovery, §Structure Design Informatics,
and Structural Biology, #Drug Disposition and Safety (DSAR), †Protein Production,⊥Pharmaceutical Sciences, ∥Analytical Sciences, Sanofi, 13, quai Jules Guesde, 94403 Vitry-sur-Seine, France
| | - Christoph Lengauer
- Oncology Drug Discovery, §Structure Design Informatics,
and Structural Biology, #Drug Disposition and Safety (DSAR), †Protein Production,⊥Pharmaceutical Sciences, ∥Analytical Sciences, Sanofi, 13, quai Jules Guesde, 94403 Vitry-sur-Seine, France
| | - Laurent Schio
- Oncology Drug Discovery, §Structure Design Informatics,
and Structural Biology, #Drug Disposition and Safety (DSAR), †Protein Production,⊥Pharmaceutical Sciences, ∥Analytical Sciences, Sanofi, 13, quai Jules Guesde, 94403 Vitry-sur-Seine, France
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221
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Abstract
Akt is a Ser-Thr kinase with pleiotropic effects on cell survival, growth and metabolism. Recent evidence from gene-deletion studies in mice, and analysis of human platelets treated with Akt inhibitors, suggest that Akt regulates platelet activation, with potential consequences for thrombosis. Akt activation is regulated by the level of phosphoinositide 3-phosphates, and proteins that regulate concentrations of this lipid also regulate Akt activation and platelet function. Although the effectors through which Akt contributes to platelet activation are not definitively known, several candidates are discussed, including endothelial nitric oxide synthase, glycogen synthase kinase 3β, phosphodiesterase 3A and the integrin β(3) tail. Selective inhibitors of Akt isoforms or of proteins that contribute to its activation, such as individual PI3K isoforms, may make attractive targets for antithrombotic therapy. This review summarizes the current literature describing Akt activity and its regulation in platelets, including speculation regarding the future of Akt or its regulatory pathways as targets for the development of antithrombotic therapies.
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Affiliation(s)
- Donna S Woulfe
- Thomas Jefferson University, Philadelphia, PA 19107, USA Tel.: +1 215 503 5152
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222
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Hughan SC, Spring CM, Schoenwaelder SM, Sturgeon S, Alwis I, Yuan Y, McFadyen JD, Westein E, Goddard D, Ono A, Yamanashi Y, Nesbitt WS, Jackson SP. Dok-2 adaptor protein regulates the shear-dependent adhesive function of platelet integrin αIIbβ3 in mice. J Biol Chem 2014; 289:5051-60. [PMID: 24385425 DOI: 10.1074/jbc.m113.520148] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
The Dok proteins are a family of adaptor molecules that have a well defined role in regulating cellular migration, immune responses, and tumor progression. Previous studies have demonstrated that Doks-1 to 3 are expressed in platelets and that Dok-2 is tyrosine-phosphorylated downstream of integrin αIIbβ3, raising the possibility that it participates in integrin αIIbβ3 outside-in signaling. We demonstrate that Dok-2 in platelets is primarily phosphorylated by Lyn kinase. Moreover, deficiency of Dok-2 leads to dysregulated integrin αIIbβ3-dependent cytosolic calcium flux and phosphatidylinositol(3,4)P2 accumulation. Although agonist-induced integrin αIIbβ3 affinity regulation was unaltered in Dok-2(-/-) platelets, Dok-2 deficiency was associated with a shear-dependent increase in integrin αIIbβ3 adhesive function, resulting in enhanced platelet-fibrinogen and platelet-platelet adhesive interactions under flow. This increase in adhesion was restricted to discoid platelets and involved the shear-dependent regulation of membrane tethers. Dok-2 deficiency was associated with an increased rate of platelet aggregate formation on thrombogenic surfaces, leading to accelerated thrombus growth in vivo. Overall, this study defines an important role for Dok-2 in regulating biomechanical adhesive function of discoid platelets. Moreover, they define a previously unrecognized prothrombotic mechanism that is not detected by conventional platelet function assays.
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Affiliation(s)
- Sascha C Hughan
- From the Australian Centre for Blood Diseases, Faculty of Medicine, Nursing, and Health Sciences, Monash University, Alfred Medical Research and Education Precinct, Commercial Road, Melbourne, Victoria 3004
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223
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Abstract
Class I phosphoinositide 3-kinases (PI3Ks) are lipid kinases that regulate multiple biological functions such as cell growth, proliferation, migration, and survival. Class I PI3Ks consist of four kinases isoforms. Over the past years many studies have documented that each isoform of PI3K plays specific biological functions in different cell types. Accumulating evidence indicates that activation of PI3K signaling is deregulated in human disease, including cancer. A major pharmaceutical effort has gone into developing PI3K inhibitors that hit multiple or individual PI3K isoforms, which are currently used in early and late-phase clinical trials. In this chapter we describe an in vitro PI3K assay that may be helpful in verifying which tumor cells have increased PI3K activity and thus may be targeted with inhibitors of PI3K.
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Affiliation(s)
- Antonio Bilancio
- Dipartimento di Biochimica, Biofisica e Patologia Generale, II Università di Napoli, Via L. De Crecchio 7, 80138, Naples, Italy,
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224
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Laurent PA, Severin S, Gratacap MP, Payrastre B. Class I PI 3-kinases signaling in platelet activation and thrombosis: PDK1/Akt/GSK3 axis and impact of PTEN and SHIP1. Adv Biol Regul 2014; 54:162-174. [PMID: 24095650 DOI: 10.1016/j.jbior.2013.09.006] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2013] [Revised: 09/05/2013] [Accepted: 09/06/2013] [Indexed: 06/02/2023]
Abstract
Class I phosphoinositide 3-kinases (PI3K) have been extensively studied in different models these last years and several isoforms are now promising drug targets to treat cancer and immune diseases. Blood platelets are non-nucleated cells critical for hemostasis and strongly involved in arterial thrombosis, a leading cause of death worldwide. Besides their role in hemostasis and thrombosis, platelets provide an interesting model to characterize the implication of the different isoforms of PI3K in signaling. They are specialized for regulated adhesion, particularly under high shear stress conditions found in arteries and use highly regulated signaling mechanisms to form and stabilize a thrombus. In this review we will highlight the role of class I PI3K in these processes and the pertinence of targeting them in the context of antithrombotic strategies but also the potential consequences on the bleeding risk of inhibiting the PI3K signaling in cancer therapy. The implication of upstream regulators of the most important isoforms of PI3K in platelets and their downstream effectors such as protein kinase B (PKB or Akt) and its target glycogen synthase kinase 3 (GSK3) will be discussed as well as the impact of PTEN and SHIP phosphatases as modulators of this pathway.
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Affiliation(s)
| | - Sonia Severin
- Inserm U1048, I2MC and Université Paul Sabatier, 31024 Toulouse Cedex 03, France
| | | | - Bernard Payrastre
- Inserm U1048, I2MC and Université Paul Sabatier, 31024 Toulouse Cedex 03, France; CHU de Toulouse, Laboratoire d'Hématologie, 31059 Toulouse Cedex 03, France.
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225
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Yanamandra M, Kole L, Giri A, Mitra S. Development of phosphocellulose paper-based screening of inhibitors of lipid kinases: case study with PI3Kβ. Anal Biochem 2013; 449:132-8. [PMID: 24380788 DOI: 10.1016/j.ab.2013.12.029] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2013] [Revised: 12/18/2013] [Accepted: 12/20/2013] [Indexed: 10/25/2022]
Abstract
The phosphatidylinositol 3-kinases (PI3Ks) are lipid kinases that regulate the cellular signal transduction pathways involved in cell growth, proliferation, survival, apoptosis, and adhesion. Deregulation of these pathways are common in oncogenesis, and they are known to be altered in other metabolic disorders as well. Despite its huge potential as an attractive target in these diseases, there is an unmet need for the development of a successful inhibitor. Unlike protein kinase inhibitors, screening for lipid kinase inhibitors has been challenging. Here we report, for the first time, the development of a radioactive lipid kinase screening platform using a phosphocellulose plate that involves transfer of radiolabeled [γ-(32)P]ATP to phosphatidylinositol 4,5-phosphate forming phosphatidylinositol 3,4,5-phosphate, captured on the phosphocellulose plate. Enzyme kinetics and inhibitory properties were established in the plate format using standard inhibitors, such as LY294002, TGX-221, and wortmannin, having different potencies toward PI3K isoforms. ATP and lipid apparent Km for both were determined and IC50 values generated that matched the historical data. Here we report the use of a phosphocellulose plate for a lipid kinase assay (PI3Kβ as the target) as an excellent platform for the identification of novel chemical entities in PI3K drug discovery.
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Affiliation(s)
- Mahesh Yanamandra
- Biology Division, GVK Biosciences Pvt. Ltd., Hyderabad 500076, Andhra Pradesh, India; Centre for Biotechnology, Institute of Science and Technology, Jawaharlal Nehru Technological University Hyderabad, 500085 Hyderabad, Andhra Pradesh, India
| | - Labanyamoy Kole
- VINS BIO, Kothur Mandal, Mahaboobnagar District 509325, Andhra Pradesh, India
| | - Archana Giri
- Centre for Biotechnology, Institute of Science and Technology, Jawaharlal Nehru Technological University Hyderabad, 500085 Hyderabad, Andhra Pradesh, India
| | - Sayan Mitra
- Biology Division, GVK Biosciences Pvt. Ltd., Hyderabad 500076, Andhra Pradesh, India.
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226
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Abstract
Platelets play a role in cancer by acting as a dynamic reservoir of effectors that facilitate tumor vascularization, growth, and metastasis. However, little information is available about the mechanism of tumor cell-induced platelet secretion (TCIPS) or the molecular machinery by which effector molecules are released from platelets. Here we demonstrate that tumor cells directly induce platelet secretion. Preincubation of platelets with human colon cancer (Caco-2), prostate cancer (PC3M-luc), or breast cancer cells (MDA-MB-231;MCF-7) resulted in a marked dose-dependent secretion of dense granules. Importantly, TCIPS preceded aggregation which always displayed a characteristic lag time. We investigated the role of platelet receptors and downstream molecules in TCIPS. The most potent modulators of TCIPS were the pharmacologic antagonists of Syk kinase, phospholipase C and protein kinase C, all downstream mediators of the immunoreceptor tyrosine-based activation motif (ITAM) cascade in platelets. Supporting this, we demonstrated a central role for the immune Fcγ receptor IIa (FcγRIIa) in mediating platelet-tumor cell cross-talk. In conclusion, we demonstrate that cancer cells can promote platelet dense-granule secretion, which is required to augment platelet aggregation. In addition, we show a novel essential role for FcγRIIa in prostate cancer cell-induced platelet activation opening the opportunity to develop novel antimetastatic therapies.
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227
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Winkler DG, Faia KL, DiNitto JP, Ali JA, White KF, Brophy EE, Pink MM, Proctor JL, Lussier J, Martin CM, Hoyt JG, Tillotson B, Murphy EL, Lim AR, Thomas BD, Macdougall JR, Ren P, Liu Y, Li LS, Jessen KA, Fritz CC, Dunbar JL, Porter JR, Rommel C, Palombella VJ, Changelian PS, Kutok JL. PI3K-δ and PI3K-γ inhibition by IPI-145 abrogates immune responses and suppresses activity in autoimmune and inflammatory disease models. ACTA ACUST UNITED AC 2013; 20:1364-74. [PMID: 24211136 DOI: 10.1016/j.chembiol.2013.09.017] [Citation(s) in RCA: 202] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2013] [Revised: 09/06/2013] [Accepted: 09/18/2013] [Indexed: 12/21/2022]
Abstract
Phosphoinositide-3 kinase (PI3K)-δ and PI3K-γ are preferentially expressed in immune cells, and inhibitors targeting these isoforms are hypothesized to have anti-inflammatory activity by affecting the adaptive and innate immune response. We report on a potent oral PI3K-δ and PI3K-γ inhibitor (IPI-145) and characterize this compound in biochemical, cellular, and in vivo assays. These studies demonstrate that IPI-145 exerts profound effects on adaptive and innate immunity by inhibiting B and T cell proliferation, blocking neutrophil migration, and inhibiting basophil activation. We explored the therapeutic value of combined PI3K-δ and PI3K-γ blockade, and IPI-145 showed potent activity in collagen-induced arthritis, ovalbumin-induced asthma, and systemic lupus erythematosus rodent models. These findings support the hypothesis that inhibition of immune function can be achieved through PI3K-δ and PI3K-γ blockade, potentially leading to significant therapeutic effects in multiple inflammatory, autoimmune, and hematologic diseases.
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228
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McFadyen JD, Jackson SP. Differentiating haemostasis from thrombosis for therapeutic benefit. Thromb Haemost 2013; 110:859-67. [PMID: 23945664 DOI: 10.1160/th13-05-0379] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2013] [Accepted: 07/18/2013] [Indexed: 12/27/2022]
Abstract
The central role of platelets in the formation of the primary haemostatic plug as well as in the development of arterial thrombosis is well defined. In general, the molecular events underpinning these processes are broadly similar. Whilst it has long been known that disturbances in blood flow, changes in platelet reactivity and enhanced coagulation reactions facilitate pathological thrombus formation, the precise details underlying these events remain incompletely understood. Intravital microscopy studies have highlighted the dynamic and heterogeneous nature of thrombus development and demonstrated that there are considerable spatiotemporal differences in the activation states of platelets within a forming thrombus. In this review we will consider the factors regulating the activation state of platelets in a developing thrombus and discuss how specific prothrombotic factors may influence this process, leading to excessive thrombus propagation. We will also discuss some potentially novel therapeutic approaches that may reduce excess thrombus development whilst minimising bleeding risk.
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Affiliation(s)
- J D McFadyen
- Shaun P. Jackson, Australian Centre for Blood Diseases, Alfred Medical Research and Education Precinct (AMREP), 6th level Burnet Tower, 89 Commercial Rd, Melbourne, Victoria 3004, Australia, Tel.: +613 9903 0131, Fax: +613 9903 0228, E-mail:
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229
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Ryu SY, Kim S. Evaluation of CK2 inhibitor (E)-3-(2,3,4,5-tetrabromophenyl)acrylic acid (TBCA) in regulation of platelet function. Eur J Pharmacol 2013; 720:391-400. [DOI: 10.1016/j.ejphar.2013.09.064] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2013] [Revised: 09/10/2013] [Accepted: 09/22/2013] [Indexed: 11/25/2022]
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230
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Shugg RPP, Thomson A, Tanabe N, Kashishian A, Steiner BH, Puri KD, Pereverzev A, Lannutti BJ, Jirik FR, Dixon SJ, Sims SM. Effects of isoform-selective phosphatidylinositol 3-kinase inhibitors on osteoclasts: actions on cytoskeletal organization, survival, and resorption. J Biol Chem 2013; 288:35346-57. [PMID: 24133210 DOI: 10.1074/jbc.m113.507525] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Phosphatidylinositol 3-kinases (PI3K) participate in numerous signaling pathways, and control distinct biological functions. Studies using pan-PI3K inhibitors suggest roles for PI3K in osteoclasts, but little is known about specific PI3K isoforms in these cells. Our objective was to determine effects of isoform-selective PI3K inhibitors on osteoclasts. The following inhibitors were investigated (targets in parentheses): wortmannin and LY294002 (pan-p110), PIK75 (α), GDC0941 (α, δ), TGX221 (β), AS252424 (γ), and IC87114 (δ). In addition, we characterized a new potent and selective PI3Kδ inhibitor, GS-9820, and explored roles of PI3K isoforms in regulating osteoclast function. Osteoclasts were isolated from long bones of neonatal rats and rabbits. Wortmannin, LY294002, GDC0941, IC87114, and GS-9820 induced a dramatic retraction of osteoclasts within 15-20 min to 65-75% of the initial area. In contrast, there was no significant retraction in response to vehicle, PIK75, TGX221, or AS252424. Moreover, wortmannin and GS-9820, but not PIK75 or TGX221, disrupted actin belts. We examined effects of PI3K inhibitors on osteoclast survival. Whereas PIK75, TGX221, and GS-9820 had no significant effect on basal survival, all blocked RANKL-stimulated survival. When studied on resorbable substrates, osteoclastic resorption was suppressed by wortmannin and inhibitors of PI3Kβ and PI3Kδ, but not other isoforms. These data are consistent with a critical role for PI3Kδ in regulating osteoclast cytoskeleton and resorptive activity. In contrast, multiple PI3K isoforms contribute to the control of osteoclast survival. Thus, the PI3Kδ isoform, which is predominantly expressed in cells of hematopoietic origin, is an attractive target for anti-resorptive therapeutics.
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Affiliation(s)
- Ryan P P Shugg
- From the Department of Physiology and Pharmacology, Schulich School of Medicine & Dentistry, Western University, London, Ontario N6A 5C1, Canada
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231
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Lang F, Münzer P, Gawaz M, Borst O. Regulation of STIM1/Orai1-dependent Ca2+ signalling in platelets. Thromb Haemost 2013; 110:925-30. [PMID: 23846758 DOI: 10.1160/th13-02-0176] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2013] [Accepted: 05/19/2013] [Indexed: 01/20/2023]
Abstract
Platelet secretion and aggregation as well as thrombus formation of blood platelets critically depend on increase of cytosolic Ca2+ concentration ([Ca2+]i) mainly resulting from intracellular Ca2+ release followed by store operated Ca2+ entry (SOCE) through Ca2+ release activated channels (CRAC). SOCE is in part accomplished by the pore forming unit Orai and its regulator stromal interaction molecule (STIM). Orai1 and STIM1 transcription is stimulated by NF-κB (nuclear factor kappa B). Serum- and glucocorticoid-inducible kinase 1 (SGK1) up-regulates NF-κB-activity in megakaryocytes and thus Orai1-expression and SOCE in platelets. SGK1 is thus a powerful regulator of platelet Ca2+-signalling and thrombus formation and presumably participates in the regulation of platelet activation by a variety of hormones as well as clinical conditions (e.g. type 2 diabetes or metabolic syndrome) associated with platelet hyperaggregability and increased risk of thromboocclusive events. SOCE in platelets is further regulated by scaffolding protein Homer and chaperone protein cyclophilin A (CyPA). Additional potential regulators of Orai1/STIM1 and thus SOCE in platelets include AMP activated kinase (AMPK), protein kinase A (PKA), reactive oxygen species, lipid rafts, pH and mitochondrial Ca2+ buffering. Future studies are required defining the significance of those mechanisms for platelet Orai1 abundance and function, for SOCE into platelets and for platelet function in cardiovascular diseases.
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Affiliation(s)
- F Lang
- Florian Lang, MD, Department of Physiology, University of Tübingen, Gmelinstr. 5, 72076 Tübingen, Germany, Tel.: +49 7071 29 72194, Fax: +49 7071 29 5618, E-mail:
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232
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Kolic J, Spigelman AF, Plummer G, Leung E, Hajmrle C, Kin T, Shapiro AMJ, Manning Fox JE, MacDonald PE. Distinct and opposing roles for the phosphatidylinositol 3-OH kinase catalytic subunits p110α and p110β in the regulation of insulin secretion from rodent and human beta cells. Diabetologia 2013; 56:1339-49. [PMID: 23568272 DOI: 10.1007/s00125-013-2882-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2012] [Accepted: 02/18/2013] [Indexed: 02/07/2023]
Abstract
AIMS/HYPOTHESIS Phosphatidylinositol 3-OH kinases (PI3Ks) regulate beta cell mass, gene transcription, and function, although the contribution of the specific isoforms is unknown. As reduced type 1A PI3K signalling is thought to contribute to impaired insulin secretion, we investigated the role of the type 1A PI3K catalytic subunits α and β (p110α and -β) in insulin granule recruitment and exocytosis in rodent and human islets. METHODS The p110α and p110β subunits were inhibited pharmacologically or by small hairpin (sh)RNA-mediated knockdown, and were directly infused or overexpressed in mouse and human islets, beta cells and INS-1 832/13 cells. Glucose-stimulated insulin secretion (GSIS), single-cell exocytosis, Ca(2+) signalling, plasma membrane granule localisation, and actin density were monitored. RESULTS Inhibition or knockdown of p110α increased GSIS. This was not due to altered Ca(2+) responses, depolymerisation of cortical actin or increased cortical granule density, but to enhanced Ca(2+)-dependent exocytosis. Intracellular infusion of recombinant PI3Kα (p110α/p85β) blocked exocytosis. Conversely, knockdown (but not pharmacological inhibition) of p110β blunted GSIS, reduced cortical granule density and impaired exocytosis. Exocytosis was rescued by direct intracellular infusion of recombinant PI3Kβ (p110β/p85β) even when p110β catalytic activity was inhibited. Conversely, both the wild-type p110β and a catalytically inactive mutant directly facilitated exocytosis. CONCLUSIONS/INTERPRETATION Type 1A PI3K isoforms have distinct and opposing roles in the acute regulation of insulin secretion. While p110α acts as a negative regulator of beta cell exocytosis and insulin secretion, p110β is a positive regulator of insulin secretion through a mechanism separate from its catalytic activity.
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Affiliation(s)
- J Kolic
- Department of Pharmacology, University of Alberta, Edmonton, AB, Canada T6G 2E1
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233
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Fritsch R, de Krijger I, Fritsch K, George R, Reason B, Kumar M, Diefenbacher M, Stamp G, Downward J. RAS and RHO families of GTPases directly regulate distinct phosphoinositide 3-kinase isoforms. Cell 2013; 153:1050-63. [PMID: 23706742 PMCID: PMC3690480 DOI: 10.1016/j.cell.2013.04.031] [Citation(s) in RCA: 220] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2012] [Revised: 03/25/2013] [Accepted: 04/08/2013] [Indexed: 12/31/2022]
Abstract
RAS proteins are important direct activators of p110α, p110γ, and p110δ type I phosphoinositide 3-kinases (PI3Ks), interacting via an amino-terminal RAS-binding domain (RBD). Here, we investigate the regulation of the ubiquitous p110β isoform of PI3K, implicated in G-protein-coupled receptor (GPCR) signaling, PTEN-loss-driven cancers, and thrombocyte function. Unexpectedly, RAS is unable to interact with p110β, but instead RAC1 and CDC42 from the RHO subfamily of small GTPases bind and activate p110β via its RBD. In fibroblasts, GPCRs couple to PI3K through Dock180/Elmo1-mediated RAC activation and subsequent interaction with p110β. Cells from mice carrying mutations in the p110β RBD show reduced PI3K activity and defective chemotaxis, and these mice are resistant to experimental lung fibrosis. These findings revise our understanding of the regulation of type I PI3K by showing that both RAS and RHO family GTPases directly regulate distinct ubiquitous PI3K isoforms and that RAC activates p110β downstream of GPCRs.
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Affiliation(s)
- Ralph Fritsch
- Signal Transduction Laboratory, Cancer Research UK London Research Institute, 44 Lincoln’s Inn Fields, London WC2A 3LY, UK
| | - Inge de Krijger
- Signal Transduction Laboratory, Cancer Research UK London Research Institute, 44 Lincoln’s Inn Fields, London WC2A 3LY, UK
| | - Kornelia Fritsch
- Experimental Histopathology Laboratory, Cancer Research UK London Research Institute, 44 Lincoln’s Inn Fields, London WC2A 3LY, UK
| | - Roger George
- Protein Purification Facility, Cancer Research UK London Research Institute, 44 Lincoln’s Inn Fields, London WC2A 3LY, UK
| | - Beth Reason
- Signal Transduction Laboratory, Cancer Research UK London Research Institute, 44 Lincoln’s Inn Fields, London WC2A 3LY, UK
| | - Madhu S. Kumar
- Signal Transduction Laboratory, Cancer Research UK London Research Institute, 44 Lincoln’s Inn Fields, London WC2A 3LY, UK
| | - Markus Diefenbacher
- Mammalian Genetics Laboratory, Cancer Research UK London Research Institute, 44 Lincoln’s Inn Fields, London WC2A 3LY, UK
| | - Gordon Stamp
- Experimental Histopathology Laboratory, Cancer Research UK London Research Institute, 44 Lincoln’s Inn Fields, London WC2A 3LY, UK
| | - Julian Downward
- Signal Transduction Laboratory, Cancer Research UK London Research Institute, 44 Lincoln’s Inn Fields, London WC2A 3LY, UK
- Lung Cancer Group, Division of Cancer Biology, The Institute of Cancer Research, 237 Fulham Road, London SW3 6JB, UK
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234
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Xie Y, Abel PW, Kirui JK, Deng C, Sharma P, Wolff DW, Toews ML, Tu Y. Identification of upregulated phosphoinositide 3-kinase γ as a target to suppress breast cancer cell migration and invasion. Biochem Pharmacol 2013; 85:1454-62. [PMID: 23500535 PMCID: PMC3637857 DOI: 10.1016/j.bcp.2013.03.001] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2013] [Revised: 02/28/2013] [Accepted: 03/01/2013] [Indexed: 12/31/2022]
Abstract
Metastasis is the major cause of breast cancer mortality. We recently reported that aberrant G-protein coupled receptor (GPCR) signaling promotes breast cancer metastasis by enhancing cancer cell migration and invasion. Phosphatidylinositol 3-kinase γ (PI3Kγ) is specifically activated by GPCRs. The goal of the present study was to determine the role of PI3Kγ in breast cancer cell migration and invasion. Immunohistochemical staining showed that the expression of PI3Kγ protein was significantly increased in invasive human breast carcinoma when compared to adjacent benign breast tissue or ductal carcinoma in situ. PI3Kγ was also detected in metastatic breast cancer cells, but not in normal breast epithelial cell line or in non-metastatic breast cancer cells. In contrast, PI3K isoforms α, β and δ were ubiquitously expressed in these cell lines. Overexpression of recombinant PI3Kγ enhanced the metastatic ability of non-metastatic breast cancer cells. Conversely, migration and invasion of metastatic breast cancer cells were inhibited by a PI3Kγ inhibitor or by siRNA knockdown of PI3Kγ but not by inhibitors or siRNAs of PI3Kα or PI3Kβ. Lamellipodia formation is a key step in cancer metastasis, and PI3Kγ blockade disrupted lamellipodia formation induced by the activation of GPCRs such as CXC chemokine receptor 4 and protease-activated receptor 1, but not by the epidermal growth factor tyrosine kinase receptor. Taken together, these results indicate that upregulated PI3Kγ conveys the metastatic signal initiated by GPCRs in breast cancer cells, and suggest that PI3Kγ may be a novel therapeutic target for development of chemotherapeutic agents to prevent breast cancer metastasis.
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MESH Headings
- Breast Neoplasms/enzymology
- Breast Neoplasms/genetics
- Breast Neoplasms/pathology
- Carcinoma, Ductal/enzymology
- Carcinoma, Ductal/genetics
- Carcinoma, Ductal/pathology
- Cell Line, Tumor
- Cell Movement/drug effects
- Cell Movement/genetics
- Class Ib Phosphatidylinositol 3-Kinase/genetics
- Class Ib Phosphatidylinositol 3-Kinase/metabolism
- Diffusion Chambers, Culture
- Epithelial Cells/cytology
- Female
- Gene Expression Regulation, Neoplastic/drug effects
- Humans
- Neoplasm Invasiveness/genetics
- Neoplasm Invasiveness/pathology
- Phosphoinositide-3 Kinase Inhibitors
- Protein Kinase Inhibitors/pharmacology
- Pseudopodia/drug effects
- Pseudopodia/pathology
- RNA, Small Interfering/genetics
- Receptor, PAR-1/genetics
- Receptor, PAR-1/metabolism
- Receptors, CXCR4/genetics
- Receptors, CXCR4/metabolism
- Signal Transduction/drug effects
- Transfection
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Affiliation(s)
- Yan Xie
- Creighton University School of Medicine, Department of Pharmacology, Omaha, NE 68178
| | - Peter W. Abel
- Creighton University School of Medicine, Department of Pharmacology, Omaha, NE 68178
| | - Joseph K. Kirui
- Creighton University School of Medicine, Department of Pharmacology, Omaha, NE 68178
| | | | | | - Dennis W. Wolff
- Creighton University School of Medicine, Department of Pharmacology, Omaha, NE 68178
| | - Myron L. Toews
- University of Nebraska Medical Center, Department of Pharmacology and Experimental Neuroscience, Omaha, NE 68198
| | - Yaping Tu
- Creighton University School of Medicine, Department of Pharmacology, Omaha, NE 68178
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235
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Jiang L, Xu C, Yu S, Liu P, Luo D, Zhou Q, Gao C, Hu H. A critical role of thrombin/PAR-1 in ADP-induced platelet secretion and the second wave of aggregation. J Thromb Haemost 2013; 11:930-40. [PMID: 23406164 DOI: 10.1111/jth.12168] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2012] [Accepted: 02/03/2013] [Indexed: 01/08/2023]
Abstract
BACKGROUND The stable or second wave of platelet aggregation often observed in ADP-stimulated platelet-rich plasma (PRP) with an artificially lowered extracellular calcium level has been attributed to enhanced thromboxane A2 (TXA2 ) generation and inhibition of ectonucleotidase activity. However, the role of thrombin in ADP-induced platelet secretion and the second wave of aggregation is unknown. OBJECTIVES AND METHODS We employed aggregometry, flow cytometry, immunoblotting and ELISA to determine whether and how thrombin participates in ADP-induced platelet secretion and the second wave of aggregation. RESULTS ADP induces a phosphoinositide 3-kinase (PI3K) pathway-dependent thrombin generation, presumably resulting from the cleavage of αII b β3 -associated prothrombin. Generated thrombin subsequently activates protease-activated receptor-1 (PAR-1) and mediates dense granule secretion and the second wave of platelet aggregation in ADP-stimulated citrated PRP. Thus, ADP-induced dense granule secretion and the second wave of platelet aggregation in PRP were similarly and non-additively blocked by thrombin inhibitor hirudin, PAR-1 antagonist SCH-79797 or PI3K inhibitor wortmannin. Moreover, ADP stimulation caused the dissociation of prothrombin from αII b β3 and an increased plasma thrombin level; both were prevented by wortmannin. Furthermore, the wortmannin-inhibited second wave of platelet aggregation by ADP was restored by a subaggregation concentration of PAR-1 activating peptide SFLLRN. Blocking TXA2 production with indomethacin or restoring extracellular calcium to physiological concentration did not influence this thrombin/PAR-1 dependence. CONCLUSIONS A PI3K-dependent thrombin generation and the resultant PAR-1 activation serve as an indispensable mechanism to relay the platelet activation process induced by ADP.
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Affiliation(s)
- L Jiang
- Department of Pathology and Pathophysiology, Zhejiang University School of Medicine, Hangzhou
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236
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Zheng Z, Miller MS, Jennings IG, Thompson PE. Mechanisms of PI3Kβ-selective inhibition revealed by reciprocal mutagenesis. ACS Chem Biol 2013; 8:679-83. [PMID: 23360067 DOI: 10.1021/cb300666s] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The p110β isoform of PI3 kinase (PI3Kβ) has been implicated in pathological disorders such as thrombosis and cancer and a number of PI3Kβ-selective inhibitors have recently progressed into clinical studies. Although crystallography studies identify a binding site conformation favored by the inhibitors, no specific interaction explains the observed selectivity. Using site-directed mutagenesis we have identified a specific tyrosine residue of the binding site Y778 that dictates the ability of the PI3Kβ isoform to bind these inhibitors. When mutated to isoleucine, PI3Kβ has reduced ability to present a specific cryptic binding site into which a range of reported PI3Kβ inhibitors can bind, and conversely when tyrosine is introduced into the same position in PI3Kα, the same inhibitors gain potency. The results provide a cogent explanation for the selectivity profiles displayed by these PI3K inhibitors and maybe others as well.
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Affiliation(s)
- Zhaohua Zheng
- Medicinal Chemistry, Monash Institute of Pharmaceutical
Sciences, Monash University, 381 Royal
Parade, Parkville 3052, Australia
| | - Michelle S. Miller
- Medicinal Chemistry, Monash Institute of Pharmaceutical
Sciences, Monash University, 381 Royal
Parade, Parkville 3052, Australia
| | - Ian G. Jennings
- Medicinal Chemistry, Monash Institute of Pharmaceutical
Sciences, Monash University, 381 Royal
Parade, Parkville 3052, Australia
| | - Philip E. Thompson
- Medicinal Chemistry, Monash Institute of Pharmaceutical
Sciences, Monash University, 381 Royal
Parade, Parkville 3052, Australia
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237
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CXCL12-Mediated Murine Neural Progenitor Cell Movement Requires PI3Kβ Activation. Mol Neurobiol 2013; 48:217-31. [DOI: 10.1007/s12035-013-8451-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2012] [Accepted: 03/25/2013] [Indexed: 11/26/2022]
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Novellasdemunt L, Tato I, Navarro-Sabate A, Ruiz-Meana M, Méndez-Lucas A, Perales JC, Garcia-Dorado D, Ventura F, Bartrons R, Rosa JL. Akt-dependent activation of the heart 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase (PFKFB2) isoenzyme by amino acids. J Biol Chem 2013; 288:10640-51. [PMID: 23457334 PMCID: PMC3624444 DOI: 10.1074/jbc.m113.455998] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2013] [Revised: 03/01/2013] [Indexed: 02/03/2023] Open
Abstract
Reciprocal regulation of metabolism and signaling allows cells to modulate their activity in accordance with their metabolic resources. Thus, amino acids could activate signal transduction pathways that control cell metabolism. To test this hypothesis, we analyzed the effect of amino acids on fructose-2,6-bisphosphate (Fru-2,6-P2) metabolism. We demonstrate that amino acids increase Fru-2,6-P2 concentration in HeLa and in MCF7 human cells. In conjunction with this, 6-phosphofructo-2-kinase activity, glucose uptake, and lactate concentration were increased. These data correlate with the specific phosphorylation of heart 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase (PFKFB2) isoenzyme at Ser-483. This activation was mediated by the PI3K and p38 signaling pathways. Furthermore, Akt inactivation blocked PFKFB2 phosphorylation and Fru-2,6-P2 production, thereby suggesting that the above signaling pathways converge at Akt kinase. In accordance with these results, kinase assays showed that amino acid-activated Akt phosphorylated PFKFB2 at Ser-483 and that knockdown experiments confirmed that the increase in Fru-2,6-P2 concentration induced by amino acids was due to PFKFB2. In addition, similar effects on Fru-2,6-P2 metabolism were observed in freshly isolated rat cardiomyocytes treated with amino acids, which indicates that these effects are not restricted to human cancer cells. In these cardiomyocytes, the glucose consumption and the production of lactate and ATP suggest an increase of glycolytic flux. Taken together, these results demonstrate that amino acids stimulate Fru-2,6-P2 synthesis by Akt-dependent PFKFB2 phosphorylation and activation and show how signaling and metabolism are inextricably linked.
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Affiliation(s)
- Laura Novellasdemunt
- From the Departament de Ciències Fisiològiques II, Campus de Bellvitge, Institut d'Investigació Biomèdica de Bellvitge (IDIBELL), Universitat de Barcelona, L'Hospitalet de Llobregat, Barcelona 08907, Spain and
| | - Irantzu Tato
- From the Departament de Ciències Fisiològiques II, Campus de Bellvitge, Institut d'Investigació Biomèdica de Bellvitge (IDIBELL), Universitat de Barcelona, L'Hospitalet de Llobregat, Barcelona 08907, Spain and
| | - Aurea Navarro-Sabate
- From the Departament de Ciències Fisiològiques II, Campus de Bellvitge, Institut d'Investigació Biomèdica de Bellvitge (IDIBELL), Universitat de Barcelona, L'Hospitalet de Llobregat, Barcelona 08907, Spain and
| | - Marisol Ruiz-Meana
- the Laboratory of Experimental Cardiology, Vall d'Hebron University Hospital and Research Institute, Universitat Autònoma de Barcelona, Barcelona 08035, Spain
| | - Andrés Méndez-Lucas
- From the Departament de Ciències Fisiològiques II, Campus de Bellvitge, Institut d'Investigació Biomèdica de Bellvitge (IDIBELL), Universitat de Barcelona, L'Hospitalet de Llobregat, Barcelona 08907, Spain and
| | - Jose Carlos Perales
- From the Departament de Ciències Fisiològiques II, Campus de Bellvitge, Institut d'Investigació Biomèdica de Bellvitge (IDIBELL), Universitat de Barcelona, L'Hospitalet de Llobregat, Barcelona 08907, Spain and
| | - David Garcia-Dorado
- the Laboratory of Experimental Cardiology, Vall d'Hebron University Hospital and Research Institute, Universitat Autònoma de Barcelona, Barcelona 08035, Spain
| | - Francesc Ventura
- From the Departament de Ciències Fisiològiques II, Campus de Bellvitge, Institut d'Investigació Biomèdica de Bellvitge (IDIBELL), Universitat de Barcelona, L'Hospitalet de Llobregat, Barcelona 08907, Spain and
| | - Ramon Bartrons
- From the Departament de Ciències Fisiològiques II, Campus de Bellvitge, Institut d'Investigació Biomèdica de Bellvitge (IDIBELL), Universitat de Barcelona, L'Hospitalet de Llobregat, Barcelona 08907, Spain and
| | - Jose Luis Rosa
- From the Departament de Ciències Fisiològiques II, Campus de Bellvitge, Institut d'Investigació Biomèdica de Bellvitge (IDIBELL), Universitat de Barcelona, L'Hospitalet de Llobregat, Barcelona 08907, Spain and
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239
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Brass LF, Tomaiuolo M, Stalker TJ. Harnessing the platelet signaling network to produce an optimal hemostatic response. Hematol Oncol Clin North Am 2013; 27:381-409. [PMID: 23714305 DOI: 10.1016/j.hoc.2013.02.002] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Once released into the circulation by megakaryocytes, circulating platelets can undergo rapid activation at sites of vascular injury and resist unwarranted activation, which can lead to heart attacks and strokes. Historically, the signaling mechanisms underlying the regulation of platelet activation have been approached as a collection of individual pathways unique to agonist. This review takes a different approach, casting platelet activation as the product of a signaling network, in which activating and restraining mechanisms interact in a flexible network that regulates platelet adhesiveness, cohesion between platelets, granule secretion, and the formation of a stable hemostatic thrombus.
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Affiliation(s)
- Lawrence F Brass
- Department of Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA.
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240
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Schmidt EM, Schmid E, Münzer P, Hermann A, Eyrich AK, Russo A, Walker B, Gu S, vom Hagen JM, Faggio C, Schaller M, Föller M, Schöls L, Gawaz M, Borst O, Storch A, Stournaras C, Lang F. Chorein sensitivity of cytoskeletal organization and degranulation of platelets. FASEB J 2013; 27:2799-806. [PMID: 23568775 DOI: 10.1096/fj.13-229286] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Chorea-acanthocytosis (ChAc), a lethal disease caused by defective chorein, is characterized by neurodegeneration and erythrocyte acanthocytosis. The functional significance of chorein in other cell types remained ill-defined. The present study revealed chorein expression in blood platelets. As compared to platelets from healthy volunteers, platelets from patients with ChAc displayed a 47% increased globular/filamentous actin ratio, indicating actin depolymerization. Moreover, phosphoinositide-3-kinase subunit p85 phosphorylation, p21 protein-activated kinase (PAK1) phosphorylation, as well as vesicle-associated membrane protein 8 (VAMP8) expression were significantly reduced in platelets from patients with ChAc (by 17, 22, and 39%, respectively) and in megakaryocytic (MEG-01) cells following chorein silencing (by 16, 54, and 11%, respectively). Activation-induced platelet secretion from dense granules (ATP release) and α granules (P-selectin exposure) were significantly less (by 55% after stimulation with 1 μg/ml CRP and by 33% after stimulation with 5 μM TRAP, respectively) in ChAc platelets than in control platelets. Furthermore, platelet aggregation following stimulation with different platelet agonists was significantly impaired. These observations reveal a completely novel function of chorein, i.e., regulation of secretion and aggregation of blood platelets.
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Affiliation(s)
- Eva-Maria Schmidt
- Department of Physiology, University of Tübingen, Gmelinstrasse 5, 72076 Tübingen, Germany
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241
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Riaz A, Ilan N, Vlodavsky I, Li JP, Johansson S. Characterization of heparanase-induced phosphatidylinositol 3-kinase-AKT activation and its integrin dependence. J Biol Chem 2013; 288:12366-75. [PMID: 23504323 DOI: 10.1074/jbc.m112.435172] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Heparanase functions as a heparan sulfate-degrading enzyme and as a ligand for an unidentified signaling receptor(s). Here, several reactions involved in the activation of the PI3K-AKT pathway by latent heparanase were characterized. Protein suppression using specific siRNAs revealed that heparanase-induced phosphorylation of AKT at Ser-473 was RICTOR-mTOR-dependent, whereas ILK and PAK1/2 were dispensable. p110α was the PI3K catalytic isoform preferred by heparanase for AKT activation and cell proliferation because the p110α inhibitor YM024 blocked these processes. Heparanase-induced AKT phosphorylation was low in mouse embryonic fibroblast cells expressing a RAS interaction-defective p110α compared with wild type cells, indicating that RAS has an important role in the PI3K-AKT activation. The response to heparanase was also inefficient in suspension cultures of several cell lines, suggesting a requirement of integrins in this pathway. Adhesion via either αVβ3 or α5β1 promoted heparanase-induced AKT phosphorylation, and a stronger effect was seen when both integrins were engaged. Simultaneous inhibition of FAK and PYK2 using a chemical inhibitor, or suppression of their expression, inhibited heparanase-induced AKT activation and cell proliferation. Stimulation of cells with heparanase enhanced their resistance against oxidative stress- or growth factor starvation-induced apoptosis. These results demonstrate that there is an intimate cross-talk between the heparanase receptor(s) and integrins during induction of the prosurvival PI3K-AKT pathway by heparanase.
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Affiliation(s)
- Anjum Riaz
- Department of Medical Biochemistry and Microbiology, Uppsala University, 75123 Uppsala, Sweden
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242
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Lin H. Isoform Selective PI3K-beta Inhibitors. CHINESE J CHEM 2013. [DOI: 10.1002/cjoc.201300030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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243
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Abstract
PI3Ks are signaling enzymes engaged by different types of membrane receptors and activated in cardiovascular diseases such as hypertension, atherosclerosis, thrombosis and heart failure. Studies performed on genetically modified animals have provided proof-of-concept that general or isoform-specific blockade of these enzymes can modify disease development and progression. Hence, therapeutic inhibition of PI3Ks with novel pharmacological compounds constitutes a promising area of drug development. In particular, inhibitors of PI3Ks have the potential to reduce blood pressure, restrain the development of atherosclerosis and/or stabilize atherosclerotic plaques, blunt platelet aggregation, prevent left ventricular remodeling and preserve myocardial contractility in heart failure. This review summarizes the rationale of PI3K inhibition in the most prevalent cardiovascular diseases, and the available data on the therapeutic effects of PI3K inhibitors in their preclinical models. Implications for future drug development and human therapy are also discussed.
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244
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Tzenaki N, Papakonstanti EA. p110δ PI3 kinase pathway: emerging roles in cancer. Front Oncol 2013; 3:40. [PMID: 23459844 PMCID: PMC3585436 DOI: 10.3389/fonc.2013.00040] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2012] [Accepted: 02/12/2013] [Indexed: 12/11/2022] Open
Abstract
Class IA PI3Ks consists of three isoforms of the p110 catalytic subunit designated p110α, p110β, and p110δ which are encoded by three separate genes. Gain-of-function mutations on PIK3CA gene encoding for p110α isoform have been detected in a wide variety of human cancers whereas no somatic mutations of genes encoding for p110β or p110δ have been reported. Unlike p110α and p110β which are ubiquitously expressed, p110δ is highly enriched in leukocytes and thus the p110δ PI3K pathway has attracted more attention for its involvement in immune disorders. However, findings have been accumulated showing that the p110δ PI3K plays a seminal role in the development and progression of some hematologic malignancies. A wealth of knowledge has come from studies showing the central role of p110δ PI3K in B-cell functions and B-cell malignancies. Further data have documented that wild-type p110δ becomes oncogenic when overexpressed in cell culture models and that p110δ is the predominant isoform expressed in some human solid tumor cells playing a prominent role in these cells. Genetic inactivation of p110δ in mice models and highly-selective inhibitors of p110δ have demonstrated an important role of this isoform in differentiation, growth, survival, motility, and morphology with the inositol phosphatase PTEN to play a critical role in p110δ signaling. In this review, we summarize our understanding of the p110δ PI3K signaling pathway in hematopoietic cells and malignancies, we highlight the evidence showing the oncogenic potential of p110δ in cells of non-hematopoietic origin and we discuss perspectives for potential novel roles of p110δ PI3K in cancer.
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Affiliation(s)
- Niki Tzenaki
- Department of Biochemistry, School of Medicine, University of Crete Heraklion, Greece
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245
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Abstract
The effects of phosphoinositide-dependent protein kinase 1 (PDK1), a master kinase in the phosphoinositide 3-kinase/Akt pathway, on platelet activation are unknown. Accordingly, platelet-specific PDK1-deficient mice were characterized to elucidate the platelet-related function(s) of PDK1. We found that PDK1 deficiency caused mild thrombocytopenia. The aggregation of PDK1(-/-) platelets was diminished in response to low levels of thrombin, U46619, and adenosine 5'-diphosphate. Further results demonstrated that PDK1 regulates thrombin-induced platelet activation by affecting αIIbβ3-mediated outside-in signaling. This result provided an explanation for the diminished spreading of PDK1(-/-) platelets on immobilized fibrinogen (Fg) and the decreased rate of clot retraction in platelet-rich plasma (PRP) containing PDK1(-/-) platelets. PDK1 deficiency diminished agonist-induced Akt Ser473 phosphorylation and thoroughly abolished Akt Thr308 and Gsk3β Ser9 phosphorylation in response to agonist treatment and platelet spreading, respectively. A Gsk3β inhibitor fully restored the aggregation of PDK1(-/-) platelets in response to low levels of thrombin, normal spreading of PDK1(-/-) platelets on Fg, and normal clot retraction in PRP containing PDK1(-/-) platelets. Those results indicated that Gsk3β is one of the major downstream effectors of PDK1 in thrombin-induced platelet activation and αIIbβ3-mediated outside-in signaling. In addition, in vivo data demonstrated that PDK1 is an important regulator in arterial thrombosis formation.
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246
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Chuang WY, Kung PH, Kuo CY, Wu CC. Sulforaphane prevents human platelet aggregation through inhibiting the phosphatidylinositol 3-kinase/Akt pathway. Thromb Haemost 2013; 109:1120-30. [PMID: 23426129 DOI: 10.1160/th12-09-0636] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2012] [Accepted: 01/23/2013] [Indexed: 01/05/2023]
Abstract
Sulforaphane, a dietary isothiocyanate found in cruciferous vegetables, has been shown to exert beneficial effects in animal models of cardiovascular diseases. However, its effect on platelet aggregation, which is a critical factor in arterial thrombosis, is still unclear. In the present study, we show that sulforaphane inhibited human platelet aggregation caused by different receptor agonists, including collagen, U46619 (a thromboxane A2 mimic), protease-activated receptor 1 agonist peptide (PAR1-AP), and an ADP P2Y12 receptor agonist. Moreover, sulforaphane significantly reduced thrombus formation on a collagen-coated surface under whole blood flow conditions. In exploring the underlying mechanism, we found that sulforaphane specifically prevented phosphatidylinositol 3-kinase (PI3K)/Akt signalling, without markedly affecting other signlaling pathways involved in platelet aggregation, such as protein kinase C activation, calcium mobilisation, and protein tyrosine phosphorylation. Although sulforaphane did not directly inhibit the catalytic activity of PI3K, it caused ubiquitination of the regulatory p85 subunit of PI3K, and prevented PI3K translocation to membranes. In addition, sulforaphane caused ubiquitination and degradation of phosphoinositide-dependent kinase 1 (PDK1), which is required for Akt activation. Therefore, sulforaphane is able to inhibit the PI3K/Akt pathway at two distinct sites. In conclusion, we have demonstrated that sulforaphane prevented platelet aggregation and reduced thrombus formation in flow conditions; our data also support that the inhibition of the PI3K/Akt pathway by sulforaphane contributes it antiplatelet effects.
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Affiliation(s)
- Wen-Ying Chuang
- Graduate Institute of Natural Products, Kaohsiung Medical University, Kaohsiung, Taiwan
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247
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Foster JG, Blunt MD, Carter E, Ward SG. Inhibition of PI3K signaling spurs new therapeutic opportunities in inflammatory/autoimmune diseases and hematological malignancies. Pharmacol Rev 2013; 64:1027-54. [PMID: 23023033 DOI: 10.1124/pr.110.004051] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
The phosphoinositide 3-kinase/mammalian target of rapamycin/protein kinase B (PI3K/mTOR/Akt) signaling pathway is central to a plethora of cellular mechanisms in a wide variety of cells including leukocytes. Perturbation of this signaling cascade is implicated in inflammatory and autoimmune disorders as well as hematological malignancies. Proteins within the PI3K/mTOR/Akt pathway therefore represent attractive targets for therapeutic intervention. There has been a remarkable evolution of PI3K inhibitors in the past 20 years from the early chemical tool compounds to drugs that are showing promise as anticancer agents in clinical trials. The use of animal models and pharmacological tools has expanded our knowledge about the contribution of individual class I PI3K isoforms to immune cell function. In addition, class II and III PI3K isoforms are emerging as nonredundant regulators of immune cell signaling revealing potentially novel targets for disease treatment. Further complexity is added to the PI3K/mTOR/Akt pathway by a number of novel signaling inputs and feedback mechanisms. These can present either caveats or opportunities for novel drug targets. Here, we consider recent advances in 1) our understanding of the contribution of individual PI3K isoforms to immune cell function and their relevance to inflammatory/autoimmune diseases as well as lymphoma and 2) development of small molecules with which to inhibit the PI3K pathway. We also consider whether manipulating other proximal elements of the PI3K signaling cascade (such as class II and III PI3Ks or lipid phosphatases) are likely to be successful in fighting off different immune diseases.
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Affiliation(s)
- John G Foster
- Inflammatory Cell Biology Laboratory, Department of Pharmacy and Pharmacology, University of Bath, Claverton Down, Bath, UK.
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248
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Pinson JA, Zheng Z, Miller MS, Chalmers DK, Jennings IG, Thompson PE. L-Aminoacyl-triazine derivatives are isoform-selective PI3Kβ inhibitors that target non-conserved Asp862 of PI3Kβ. ACS Med Chem Lett 2013; 4:206-210. [PMID: 23795239 DOI: 10.1021/ml300336j] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
A series of aminoacyl-triazine derivatives based upon the pan-PI3K inhibitor ZSTK474 were identified as potent and isoform selective inhibitors of PI3Kβ. The compounds showed selectivity based upon stereochemistry with L-amino acyl derivatives preferring PI3Kβ while their D-congeners favoured PI3Kδ. The mechanistic basis of this inhibition was studied using site-directed mutants. One Asp residue, D862 was identified as a critical participant in binding to the PI3Kβ-selective inhibitors distinguishing this class from other reported PI3Kβ-selective inhibitors. The compounds show strong inhibition of cellular Akt phosphorylation and growth of PTEN-deficient MD-MBA-468 cells.
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Affiliation(s)
- Jo-Anne Pinson
- Medicinal Chemistry, Monash
Institute of Pharmaceutical Sciences, Monash University, 381 Royal
Parade, Parkville 3052 Australia
| | - Zhaohua Zheng
- Medicinal Chemistry, Monash
Institute of Pharmaceutical Sciences, Monash University, 381 Royal
Parade, Parkville 3052 Australia
| | - Michelle S. Miller
- Medicinal Chemistry, Monash
Institute of Pharmaceutical Sciences, Monash University, 381 Royal
Parade, Parkville 3052 Australia
| | - David K. Chalmers
- Medicinal Chemistry, Monash
Institute of Pharmaceutical Sciences, Monash University, 381 Royal
Parade, Parkville 3052 Australia
| | - Ian G. Jennings
- Medicinal Chemistry, Monash
Institute of Pharmaceutical Sciences, Monash University, 381 Royal
Parade, Parkville 3052 Australia
| | - Philip E. Thompson
- Medicinal Chemistry, Monash
Institute of Pharmaceutical Sciences, Monash University, 381 Royal
Parade, Parkville 3052 Australia
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249
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Novel approaches to inhibitor design for the p110β phosphoinositide 3-kinase. Trends Pharmacol Sci 2013; 34:149-53. [PMID: 23411347 DOI: 10.1016/j.tips.2012.12.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2012] [Revised: 12/17/2012] [Accepted: 12/18/2012] [Indexed: 12/31/2022]
Abstract
Phosphoinositide (PI) 3-kinases are essential regulators of cellular proliferation, survival, metabolism, and motility that are frequently dysregulated in human disease. The design of inhibitors to target the PI 3-kinase/mTOR pathway is a major area of investigation by both academic laboratories and the pharmaceutical industry. This review focuses on the Class IA PI 3-kinase p110β, which plays a unique role in thrombogenesis and in the growth of tumors with deletion or loss-of-function mutation of the Phosphatase and Tensin Homolog (PTEN) lipid phosphatase. Several p110β-selective inhibitors that target the ATP-binding site in the kinase domain have been identified. However, recent discoveries regarding the regulatory mechanisms that control p110β activity suggest alternative strategies by which to disrupt signaling by this PI 3-kinase isoform. This review summarizes the current status of p110β-specific inhibitors and discusses how these new insights into p110 regulation might be used to devise novel pharmacological inhibitors.
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250
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Nacht M, Qiao L, Sheets MP, St Martin T, Labenski M, Mazdiyasni H, Karp R, Zhu Z, Chaturvedi P, Bhavsar D, Niu D, Westlin W, Petter RC, Medikonda AP, Singh J. Discovery of a potent and isoform-selective targeted covalent inhibitor of the lipid kinase PI3Kα. J Med Chem 2013; 56:712-21. [PMID: 23360348 DOI: 10.1021/jm3008745] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
PI3Kα has been identified as an oncogene in human tumors. By use of rational drug design, a targeted covalent inhibitor 3 (CNX-1351) was created that potently and specifically inhibits PI3Kα. We demonstrate, using mass spectrometry and X-ray crystallography, that the selective inhibitor covalently modifies PI3Kα on cysteine 862 (C862), an amino acid unique to the α isoform, and that PI3Kβ, -γ, and -δ are not covalently modified. 3 is able to potently (EC(50) < 100 nM) and specifically inhibit signaling in PI3Kα-dependent cancer cell lines, and this leads to a potent antiproliferative effect (GI(50) < 100 nM). A covalent probe, 8 (CNX-1220), which selectively bonds to PI3Kα, was used to investigate the duration of occupancy of 3 with PI3Kα in vivo. This is the first report of a PI3Kα-selective inhibitor, and these data demonstrate the biological impact of selectively targeting PI3Kα.
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Affiliation(s)
- Mariana Nacht
- Celgene Avilomics Research, 45 Wiggins Avenue, Bedford, Massachusetts 01730, USA.
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