Hematopoiesis is regulated by growth factors and cytokines, many of which signal via protein- tyrosine kinases (PTKs). Abnormal PTKs cause myeloproliferative disorders (MPD) and/or leukemia; e.g., leukemia-associated translocations that encode fusion-PTKs (e.g. Bcr/Abl, Tel-Jak2), or point mutations in PTKs, such as the V617F mutation in Jak2 found in many adult MPDs. Protein-tyrosine phosphatases (PTPs) also regulate tyrosyl phosphorylation. Their roles are less well understood, and until recently, PTP mutations had not been identified in MPD/leukemia. The long range goal of this research is to understand the function of the SH2-containing PTP Shp2 (PTPn11) and its binding protein, Gab2, in normal hematopoiesis and disease. Earlier work established that Shp2 in required for cytokine-evoked Ras/Erk pathway activation. More recently, mutations in Shp2, similar to """"""""activated mutants"""""""" we generated earlier, were identified in human disease. Germ-line Shp2 mutations cause Noonan syndrome, (NS) an autosomal dominant disorder featuring developmental defects and increased risk of MPD, especially juvenile myelomonocytic leukemia (JMML). Somatic Shp2 mutations are found in JMML and other leukemias. JMML cases without Shp2 mutation have activated Ras or loss-of-function Nf1 mutations, consistent with Shp2's role in regulating Ras, but the biochemical and biological consequences of disease-associated Shp2 mutations was unclear. During the current funding period, we generated and characterized mouse models for NS and JMML. Our results suggested that leukemia-associated Shp2 mutants are strong hypermorphs that cause MPD by enhancing IL3/GMCSF signaling, whereas NS alleles are weaker hypermorphs. However, the extent to which the intrinsic properties of an Shp2 mutation determine disease phenotype, as opposed to genetic modifiers and/or cooperating alleles remains unclear. The target cell in which leukemogenic Shp2 acts remains unidentified, and the precise mechanism by which leukemogenic Shp2 mutants enhance IL3/GMCSF signaling remains unknown. In Preliminary Studies, we have developed a new, unique """"""""knock-in"""""""" model for the leukemogenic mutant D61Y and an allelic series of other disease- associated Shp2 knock-in mutants. We will use these models to delineate the effect of leukemogenic and NS mutants, expressed under endogenous promoter control, on hematopoiesis and hematopoietic cell signaling, to identify the target cell(s) for Shp2-evoked MPD, and to assess the relative contribution of disease gene, modifier loci, and secondary events to MPD development. Very recent data indicate that leukemogenic Shp2 mutants act by enhancing Jak2 activation, suggesting a shared molecular pathway between childhood and adult MPD. We also will determine the mechanisms and consequences of Jak2 hyperactivation, and test whether Shp2 mutations may also play a role in adult MPD. ? ? ?

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Project (R01)
Project #
2R01CA114945-09A2
Application #
7145301
Study Section
Special Emphasis Panel (ZRG1-ONC-U (90))
Program Officer
Mufson, R Allan
Project Start
1996-03-15
Project End
2011-05-31
Budget Start
2006-07-01
Budget End
2007-05-31
Support Year
9
Fiscal Year
2006
Total Cost
$394,842
Indirect Cost
Name
Beth Israel Deaconess Medical Center
Department
Type
DUNS #
071723621
City
Boston
State
MA
Country
United States
Zip Code
02215
Wang, Lijun; Iorio, Caterina; Yan, Kevin et al. (2018) A ERK/RSK-mediated negative feedback loop regulates M-CSF-evoked PI3K/AKT activation in macrophages. FASEB J 32:875-887
Usenko, Tatiana; Chan, Gordon; Torlakovic, Emina et al. (2014) Leukemogenic Ptpn11 allele causes defective erythropoiesis in mice. PLoS One 9:e109682
Johnson, Dylan J; Pao, Lily I; Dhanji, Salim et al. (2013) Shp1 regulates T cell homeostasis by limiting IL-4 signals. J Exp Med 210:1419-31
Chan, Gordon; Gu, Shengqing; Neel, Benjamin G (2013) Erk1 and Erk2 are required for maintenance of hematopoietic stem cells and adult hematopoiesis. Blood 121:3594-8
Abram, Clare L; Roberge, Gray L; Pao, Lily I et al. (2013) Distinct roles for neutrophils and dendritic cells in inflammation and autoimmunity in motheaten mice. Immunity 38:489-501
Alenghat, Francis J; Baca, Quentin J; Rubin, Nooreen T et al. (2012) Macrophages require Skap2 and Sirp? for integrin-stimulated cytoskeletal rearrangement. J Cell Sci 125:5535-45
Futami, Muneyoshi; Zhu, Quan-Sheng; Whichard, Zakary L et al. (2011) G-CSF receptor activation of the Src kinase Lyn is mediated by Gab2 recruitment of the Shp2 phosphatase. Blood 118:1077-86
Chan, Gordon; Cheung, Laurene S; Yang, Wentian et al. (2011) Essential role for Ptpn11 in survival of hematopoietic stem and progenitor cells. Blood 117:4253-61
Xu, Dan; Wang, Siying; Yu, Wen-Mei et al. (2010) A germline gain-of-function mutation in Ptpn11 (Shp-2) phosphatase induces myeloproliferative disease by aberrant activation of hematopoietic stem cells. Blood 116:3611-21
Araki, Toshiyuki; Chan, Gordon; Newbigging, Susan et al. (2009) Noonan syndrome cardiac defects are caused by PTPN11 acting in endocardium to enhance endocardial-mesenchymal transformation. Proc Natl Acad Sci U S A 106:4736-41

Showing the most recent 10 out of 13 publications