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Nayak RC, Hegde S, Althoff MJ, Wellendorf AM, Mohmoud F, Perentesis J, Reina-Campos M, Reynaud D, Zheng Y, Diaz-Meco MT, Moscat J, Cancelas JA. The signaling axis atypical protein kinase C λ/ι-Satb2 mediates leukemic transformation of B-cell progenitors. Nat Commun 2019; 10:46. [PMID: 30610188 PMCID: PMC6320370 DOI: 10.1038/s41467-018-07846-y] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2017] [Accepted: 11/21/2018] [Indexed: 01/01/2023] Open
Abstract
Epigenetically regulated transcriptional plasticity has been proposed as a mechanism of differentiation arrest and resistance to therapy. BCR-ABL leukemias result from leukemic stem cell/progenitor transformation and represent an opportunity to identify epigenetic progress contributing to lineage leukemogenesis. Primary human and murine BCR-ABL+ leukemic progenitors have increased activation of Cdc42 and the downstream atypical protein kinase C (aPKC). While the isoform aPKCζ behaves as a leukemic suppressor, aPKCλ/ι is critically required for oncogenic progenitor proliferation, survival, and B-cell differentiation arrest, but not for normal B-cell lineage differentiation. In vitro and in vivo B-cell transformation by BCR-ABL requires the downregulation of key genes in the B-cell differentiation program through an aPKC λ/ι-Erk dependent Etv5/Satb2 chromatin repressive signaling complex. Genetic or pharmacological targeting of aPKC impairs human oncogenic addicted leukemias. Therefore, the aPKCλ/ι-SATB2 signaling cascade is required for leukemic BCR-ABL+ B-cell progenitor transformation and is amenable to non-tyrosine kinase inhibition. The upstream pathways regulating leukemic transcriptional plasticity for differentiation arrest and resistance to therapy are unclear. Here the authors show that aPKC λ/ι-controls leukemic B-cell precursor differentiation arrest trough RAC/MEK/ERK/SATB2 epigenetic repression
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Affiliation(s)
- R C Nayak
- Division of Experimental Hematology, Cancer and Blood Diseases Institute, Cincinnati Children's Hospital Medical Center, 3333 Burnet Ave., Cincinnati, OH, 45229, USA
| | - S Hegde
- Division of Experimental Hematology, Cancer and Blood Diseases Institute, Cincinnati Children's Hospital Medical Center, 3333 Burnet Ave., Cincinnati, OH, 45229, USA.,Hoxworth Blood Center, University of Cincinnati, 3130 Highland Ave., Cincinnati, OH, 45267, USA
| | - M J Althoff
- Division of Experimental Hematology, Cancer and Blood Diseases Institute, Cincinnati Children's Hospital Medical Center, 3333 Burnet Ave., Cincinnati, OH, 45229, USA.,Hoxworth Blood Center, University of Cincinnati, 3130 Highland Ave., Cincinnati, OH, 45267, USA.,Graduate Program of Cancer & Cell Biology, University of Cincinnati College of Medicine, Cincinnati, OH, 45267, USA
| | - A M Wellendorf
- Division of Experimental Hematology, Cancer and Blood Diseases Institute, Cincinnati Children's Hospital Medical Center, 3333 Burnet Ave., Cincinnati, OH, 45229, USA
| | - F Mohmoud
- Graduate Program of Cancer & Cell Biology, University of Cincinnati College of Medicine, Cincinnati, OH, 45267, USA
| | - J Perentesis
- Division of Oncology, Cancer and Blood Diseases Institute, Cincinnati Children's Hospital Medical Center, 3333 Burnet Ave., Cincinnati, OH, 45229, USA
| | - M Reina-Campos
- Cancer Metabolism and Signaling Networks Program, Sanford Burnham Prebys Medical Discovery Institute, 10901 North Torrey Pines Road, La Jolla, CA, 92037, USA
| | - D Reynaud
- Division of Experimental Hematology, Cancer and Blood Diseases Institute, Cincinnati Children's Hospital Medical Center, 3333 Burnet Ave., Cincinnati, OH, 45229, USA
| | - Y Zheng
- Division of Experimental Hematology, Cancer and Blood Diseases Institute, Cincinnati Children's Hospital Medical Center, 3333 Burnet Ave., Cincinnati, OH, 45229, USA
| | - M T Diaz-Meco
- Cancer Metabolism and Signaling Networks Program, Sanford Burnham Prebys Medical Discovery Institute, 10901 North Torrey Pines Road, La Jolla, CA, 92037, USA
| | - J Moscat
- Cancer Metabolism and Signaling Networks Program, Sanford Burnham Prebys Medical Discovery Institute, 10901 North Torrey Pines Road, La Jolla, CA, 92037, USA
| | - J A Cancelas
- Division of Experimental Hematology, Cancer and Blood Diseases Institute, Cincinnati Children's Hospital Medical Center, 3333 Burnet Ave., Cincinnati, OH, 45229, USA. .,Hoxworth Blood Center, University of Cincinnati, 3130 Highland Ave., Cincinnati, OH, 45267, USA. .,Graduate Program of Cancer & Cell Biology, University of Cincinnati College of Medicine, Cincinnati, OH, 45267, USA.
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Ma D, Fang Q, Wang P, Gao R, Wu W, Lu T, Cao L, Hu X, Wang J. Induction of heme oxygenase-1 by Na+-H+ exchanger 1 protein plays a crucial role in imatinib-resistant chronic myeloid leukemia cells. J Biol Chem 2015; 290:12558-71. [PMID: 25802333 DOI: 10.1074/jbc.m114.626960] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2014] [Indexed: 12/18/2022] Open
Abstract
Resistance toward imatinib (IM) and other BCR/ABL tyrosine kinase inhibitors remains troublesome in the treatment of advanced stage chronic myeloid leukemia (CML). The aim of this study was to estimate the reversal effects of down-regulation of Na(+)/H(+) exchanger 1 (NHE1) on the chemoresistance of BCR-ABL-positive leukemia patients' cells and cell lines. After treatment with the specific NHE1 inhibitor cariporide to decrease intracellular pH (pHi), the heme oxygenase-1 (HO-1) levels of the K562R cell line and cells from IM-insensitive CML patients decreased. HO-1, as a Bcr/Abl-dependent survival molecule in CML cells, is important for the resistance to tyrosine kinase inhibitors in patients with newly diagnosed CML or IM-resistant CML. Silencing PKC-β and Nrf-2 or treatment with inhibitors of p38 pathways obviously blocked NHE1-induced HO-1 expression. Furthermore, treatment with HO-1 or p38 inhibitor plus IM increased the apoptosis of the K562R cell line and IM-insensitive CML patients' cells. Inhibiting HO-1 enhanced the activation of caspase-3 and poly(ADP-ribose) polymerase-1. Hence, the results support the anti-apoptotic role of HO-1 induced by NHE1 in the K562R cell line and IM-insensitive CML patients and provide a mechanism by which inducing HO-1 expression via the PKC-β/p38-MAPK pathway may promote tumor resistance to oxidative stress.
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Affiliation(s)
- Dan Ma
- From the Department of Hematology, Affiliated Hospital of Guiyang Medical University, Guiyang 550004, China, Department of Pharmacy, Affiliated BaiYun Hospital of Guiyang Medical University, Guiyang 550014, China
| | - Qin Fang
- Department of Pharmacy, Affiliated BaiYun Hospital of Guiyang Medical University, Guiyang 550014, China, Department of Pharmacy, Affiliated Hospital of Guiyang Medical University, Guiyang 550004, China, and
| | - Ping Wang
- From the Department of Hematology, Affiliated Hospital of Guiyang Medical University, Guiyang 550004, China, Guizhou Province Hematopoietic Stem Cell Transplantation Center and Key Laboratory of Hematological Disease Diagnostic and Treatment Centre, Guiyang 550004, China
| | - Rui Gao
- From the Department of Hematology, Affiliated Hospital of Guiyang Medical University, Guiyang 550004, China, Guizhou Province Hematopoietic Stem Cell Transplantation Center and Key Laboratory of Hematological Disease Diagnostic and Treatment Centre, Guiyang 550004, China
| | - Weibing Wu
- From the Department of Hematology, Affiliated Hospital of Guiyang Medical University, Guiyang 550004, China, Guizhou Province Hematopoietic Stem Cell Transplantation Center and Key Laboratory of Hematological Disease Diagnostic and Treatment Centre, Guiyang 550004, China
| | - Tangsheng Lu
- School of Pharmacy, Guiyang Medical University, Guiyang 550004, China
| | - Lu Cao
- School of Pharmacy, Guiyang Medical University, Guiyang 550004, China
| | - Xiuying Hu
- From the Department of Hematology, Affiliated Hospital of Guiyang Medical University, Guiyang 550004, China, Guizhou Province Hematopoietic Stem Cell Transplantation Center and Key Laboratory of Hematological Disease Diagnostic and Treatment Centre, Guiyang 550004, China
| | - Jishi Wang
- From the Department of Hematology, Affiliated Hospital of Guiyang Medical University, Guiyang 550004, China, Guizhou Province Hematopoietic Stem Cell Transplantation Center and Key Laboratory of Hematological Disease Diagnostic and Treatment Centre, Guiyang 550004, China,
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Ruvolo PP, Zhou L, Watt JC, Ruvolo VR, Burks JK, Jiffar T, Kornblau S, Konopleva M, Andreeff M. Targeting PKC-mediated signal transduction pathways using enzastaurin to promote apoptosis in acute myeloid leukemia-derived cell lines and blast cells. J Cell Biochem 2011; 112:1696-707. [PMID: 21360576 PMCID: PMC3394435 DOI: 10.1002/jcb.23090] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Recent studies in acute myeloid leukemia (AML) suggest activation of pro-proliferative signaling cascades including those mediated by protein kinase C (PKC) represent a poor prognostic factor for patients. The classical PKC isoforms α and β generally support survival signaling and have emerged as important targets for anti-cancer therapy. Enzastaurin is a PKC β inhibitor and is in clinical trials for lymphomas, gliomas, and lung cancer. Presently, it is not known if enzastaurin could be effective against AML. In the current study, we found that high dose enzastaurin was found to promote apoptosis in the AML-derived cell lines and in blast cells from AML patients. The mechanism of cell death, however, likely does not involve PKC β as another PKC β inhibitor was not toxic to AML cell lines and did not promote enzastaurin-induced cell killing. While enzastaurin is fairly specific for PKC β, the agent can inhibit other PKC isoforms at higher concentrations. Enzastaurin was effective at inhibiting PKC α phosphorylation and membrane localization in the AML cell lines and suppressed phosphorylation of BCL2. Furthermore, enzastaurin suppressed activation of ERK (which can be activated by PKC α). Analysis of the serine/threonine phosphorylation profile in HL60 cells after enzastaurin treatment revealed that the drug inhibits the phosphorylation of a distinct set of proteins while promoting phosphorylation of another set of proteins. This suggests the drug may regulate multiple signaling pathways. Taken together, these findings suggest that enzastaurin could be effective in the therapy of AML.
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Affiliation(s)
- Peter P. Ruvolo
- Department of Leukemia, The University of Texas MD Anderson Cancer Center, Houston, Texas
- Division of Signal Transduction and Apoptosis, University of Minnesota Hormel Institute, Austin, Minnesota
| | - Liran Zhou
- Department of Leukemia, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Julie C. Watt
- Department of Leukemia, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Vivian R. Ruvolo
- Department of Leukemia, The University of Texas MD Anderson Cancer Center, Houston, Texas
- Division of Signal Transduction and Apoptosis, University of Minnesota Hormel Institute, Austin, Minnesota
| | - Jared K. Burks
- Department of Leukemia, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Tilahun Jiffar
- Division of Signal Transduction and Apoptosis, University of Minnesota Hormel Institute, Austin, Minnesota
| | - Steven Kornblau
- Department of Leukemia, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Marina Konopleva
- Department of Leukemia, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Michael Andreeff
- Department of Leukemia, The University of Texas MD Anderson Cancer Center, Houston, Texas
- Department of Stem Cell Transplantation, The University of Texas MD Anderson Cancer Center, Houston, Texas
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BMS-214662 induces mitochondrial apoptosis in chronic myeloid leukemia (CML) stem/progenitor cells, including CD34+38- cells, through activation of protein kinase Cbeta. Blood 2009; 114:4186-96. [PMID: 19738029 DOI: 10.1182/blood-2009-05-219550] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Chronic myeloid leukemia (CML) is a hematopoietic stem cell disorder maintained by cancer stem cells. To target this population, we investigated the mechanism of action of BMS-214662, developed as a farnesyl transferase inhibitor (FTI) and unique in inducing apoptosis in these cells. By contrast, a related congener and equally effective FTI, BMS-225975 does not induce apoptosis, indicating a novel mechanism of action. BMS-214662 significantly and selectively induced apoptosis in primitive CD34(+)38(-) CML compared with normal cells. Apoptosis proceeded via the intrinsic pathway: Bax conformational changes, loss of mitochondrial membrane potential, generation of reactive oxygen species, release of cytochrome c, and caspase-9/3 activation were noted. Up-regulation of protein kinase Cbeta (PKCbeta), down-regulation of E2F1, and phosphorylation of cyclin A-associated cyclin-dependent kinase 2 preceded these changes. Cotreatment of CML CD34(+) and CD34(+)38(-) cells with PKC modulators, bryostatin-1, or hispidin markedly decreased these early events and the subsequent apoptosis. None of these events was elicited by BMS-214662 in normal CD34(+) cells or by BMS-225975 in CML CD34(+) cells. These data suggest that BMS-214662 selectively elicits a latent apoptotic pathway in CML stem cells that is initiated by up-regulation of PKCbeta and mediated by Bax activation, providing a molecular framework for development of novel therapeutics.
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Role of PKCβ in hepatocellular carcinoma cells migration and invasion in vitro: a potential therapeutic target. Clin Exp Metastasis 2008; 26:189-95. [DOI: 10.1007/s10585-008-9230-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2008] [Accepted: 11/26/2008] [Indexed: 02/01/2023]
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Pierce A, Carney L, Hamza HG, Griffiths JR, Zhang L, Whetton BA, Gonzalez Sanchez MB, Tamura T, Sternberg D, Whetton AD. THOC5 spliceosome protein: a target for leukaemogenic tyrosine kinases that affects inositol lipid turnover. Br J Haematol 2008; 141:641-50. [PMID: 18373705 DOI: 10.1111/j.1365-2141.2008.07090.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The fusion protein TEL/PDGFRB is associated with chronic myelomonocytic leukaemia and has intrinsic tyrosine kinase activity. The effects of TEL/PDGFRB were assessed using the multipotent haemopoietic cell line FDCP-Mix. In the absence of growth factors, TEL/PDGFRB expression increased survival that was associated with elevated levels of phosphatidylinositol 3,4,5 trisphosphate (PIP3). Whilst TEL/PDGFRB had subtle effects on the growth factor requirements it had a profound effect on differentiation. The cells became refractory to cytokine-stimulated development, showing limited maturation but failing to produce fully mature cells. We have previously identified the spliceosome protein THOC5 as a target in macrophage colony-stimulating factor signalling and a protein involved in the regulation of transcription factor expression. TEL/PDGFRB expression increased the expression and phosphorylation of THOC5. Elevated expression of THOC5 increased PIP3 levels and decreased apoptosis. Mass spectrometry was used to identify a site for TEL/PDGFRB-mediated phosphorylation on THOC5, which was shown to be a target for a number of other leukaemogenic tyrosine kinases. Thus, THOC5 is a novel target for modulation of signal transduction with a potential role in leukaemogenesis.
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Affiliation(s)
- Andrew Pierce
- Stem Cell and Leukaemia Proteomics Laboratory, Faculty of Medical and Human Sciences, University of Manchester, Manchester, UK
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Redig AJ, Platanias LC. The protein kinase C (PKC) family of proteins in cytokine signaling in hematopoiesis. J Interferon Cytokine Res 2007; 27:623-36. [PMID: 17784814 DOI: 10.1089/jir.2007.0007] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The members of the protein kinase C (PKC) family of proteins play important roles in signaling for various growth factors, cytokines, and hormones. Extensive work over the years has led to the identification of three major groups of PKC isoforms. These include the classic PKCs (PKCalpha, PKCbeta(I), PKCbeta(II), PKCgamma), the novel PKCs (PKCdelta, PKCepsilon, PKCeta, PKCmu, PKCtheta), and the atypical PKCs (PKCzeta, PKCiota/lambda). All these PKC subtypes have been shown to participate in the generation of signals for important cellular processes and to mediate diverse and, in some cases, opposing biologic responses. There is emerging evidence that these kinases also play key functional roles in the regulation of cell growth, apoptosis, and differentiation of hematopoietic cells. In this review, both the engagement of the various PKC members in cytokine and growth factor signaling and their role in the regulation of hematopoiesis are discussed.
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Affiliation(s)
- Amanda J Redig
- Robert H. Lurie Comprehensive Cancer Center and Division of Hematology-Oncology, Northwestern University Medical School, 300 East Superior Street, Chicago, IL 60611, USA
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Lothstein L, Savranskaya L, Sweatman TW. N-Benzyladriamycin-14-valerate (AD 198) cytotoxicty circumvents Bcr-Abl anti-apoptotic signaling in human leukemia cells and also potentiates imatinib cytotoxicity. Leuk Res 2006; 31:1085-95. [PMID: 17187856 DOI: 10.1016/j.leukres.2006.11.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2006] [Revised: 10/26/2006] [Accepted: 11/12/2006] [Indexed: 01/08/2023]
Abstract
Bcr-Abl activity in chronic myelogenous leukemia (CML) results in dysregulated cell proliferation and resistance against multiple cytotoxic agents due to the constitutive activation of proliferative signaling pathways. Currently, the most effective treatment of CML is the inhibition of Bcr-Abl activity by imatinib mesylate (Gleevec). Imatinib efficacy is limited by development of resistance through either expression of Bcr-Abl variants that bind imatinib less avidly, increased expression of Bcr-Abl, or expression of multidrug transport proteins. N-Benzyladriamycin-14-valerate (AD 198) is a novel antitumor PKC activating agent that triggers rapid apoptosis through PKC-delta activation and mitochondrial depolarization in a manner that is unaffected by Bcl-2 expression. We demonstrate that Bcr-Abl expression does not confer resistance to AD 198. Further, AD 198 rapidly induces Erk1/2 and STAT5 phosphorylation prior to cytochrome c release from mitochondria, indicating that proliferative pathways are active even as drug-treated cells undergo apoptosis. At sub-cytotoxic doses, AD 198 and its cellular metabolite, N-benzyladriamycin (AD 288) sensitize CML cells to imatinib through a supra-additive reduction in the level of Bcr-Abl protein expression. These results suggest that AD 198 is an effective treatment for CML both in combination with imatinib and alone against imatinib-resistant CML cells.
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Affiliation(s)
- Leonard Lothstein
- Department of Pharmacology and The UT Cancer Institute, The University of Tennessee Health Science Center, Memphis, TN 38163, USA.
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Martelli AM, Evangelisti C, Nyakern M, Manzoli FA. Nuclear protein kinase C. Biochim Biophys Acta Mol Cell Biol Lipids 2006; 1761:542-51. [PMID: 16574477 DOI: 10.1016/j.bbalip.2006.02.009] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2005] [Accepted: 02/16/2006] [Indexed: 11/20/2022]
Abstract
Protein kinase C (PKC) isozymes constitute a family of ubiquitous phosphotransferases which act as key transducers in many agonist-induced signaling cascades. To date, at least 11 different PKC isotypes have been identified and are believed to play distinct regulatory roles. PKC isoforms are physiologically activated by a number of lipid cofactors. PKC is thought to reside in the cytoplasm in an inactive conformation and to translocate to the plasma membrane or cytoplasmic organelles upon cell activation by different stimuli. However, a sizable body of evidence collected over the last 20 years has shown PKC to be capable of translocating to the nucleus. Furthermore, PKC isoforms are resident within the nucleus. Studies from independent laboratories have to led to the identification of quite a few nuclear proteins which are PKC substrates and to the characterization of nuclear PKC-binding proteins which may be critical for finely tuning PKC function in this cell microenvironment. Several lines of evidence suggest that nuclear PKC isozymes are involved in the regulation of biological processes as important as cell proliferation and differentiation, gene expression, neoplastic transformation, and apoptosis. In this review, we shall highlight the most intriguing and updated findings about the functions of nuclear PKC isozymes.
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Affiliation(s)
- Alberto M Martelli
- Dipartimento di Scienze Anatomiche Umane e Fisiopatologia dell'Apparato Locomotore, Sezione di Anatomia Umana, Cell Signalling Laboratory, Università di Bologna, 40126 Bologna, Italy.
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Vichalkovski A, Baltensperger K, Thomann D, Porzig H. Two different pathways link G-protein-coupled receptors with tyrosine kinases for the modulation of growth and survival in human hematopoietic progenitor cells. Cell Signal 2005; 17:447-59. [PMID: 15601623 DOI: 10.1016/j.cellsig.2004.09.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2004] [Accepted: 09/08/2004] [Indexed: 01/28/2023]
Abstract
The G-protein-coupled receptor agonists CXCL12 (SDF-1, a chemokine) and thrombin showed opposite effects on growth and survival of multipotent and erythroid human hematopoietic progenitor cells. CXCL12 promoted growth in multipotent cells by activating the RhoA-Rho kinase pathway. Its effect was largely blocked by Y-27632, a specific inhibitor of Rho kinase, and by clostridial toxin B, a specific inhibitor of Rho family proteins. Rho activation required a G(i)-mediated stimulation of tyrosine kinases, which was blocked by PP2 and tyrphostin AG 490, inhibitors of Src and Jak type kinases, respectively. By contrast, in erythroid cells, inhibitors of Src family and c-Abl tyrosine kinases (tyrphostin AG 82, PP2, imatinib) enhanced protein kinase C (PKC)-dependent cell growth and antagonized thrombin-promoted apoptosis by specifically stimulating PKCbeta activity. The PKC activating phorbol ester PMA (a growth factor in erythroid cells) induced the activation of Lyn and c-Abl tyrosine kinases, thus establishing a feedback inhibition of PKCbeta. Hence, developmental stage-specific crosstalk between PKC subtypes and tyrosine kinases appear to determine whether growth and survival of hematopoietic cells are promoted or inhibited by G-protein-coupled receptor agonists.
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Affiliation(s)
- Anton Vichalkovski
- Department of Pharmacology, University of Bern, Friedbuehlstrasse 49, CH-3010 Bern, Switzerland
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