Essential role for Ptpn11 in survival of hematopoietic stem and progenitor cells

Cancer Biology Program, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, USA.
Blood (Impact Factor: 10.45). 02/2011; 117(16):4253-61. DOI: 10.1182/blood-2010-11-319517
Source: PubMed


Src homology 2 domain-containing phosphatase 2 (Shp2), encoded by Ptpn11, is a member of the nonreceptor protein-tyrosine phosphatase family, and functions in cell survival, proliferation, migration, and differentiation in many tissues. Here we report that loss of Ptpn11 in murine hematopoietic cells leads to bone marrow aplasia and lethality. Mutant mice show rapid loss of hematopoietic stem cells (HSCs) and immature progenitors of all hematopoietic lineages in a gene dosage-dependent and cell-autonomous manner. Ptpn11-deficient HSCs and progenitors undergo apoptosis concomitant with increased Noxa expression. Mutant HSCs/progenitors also show defective Erk and Akt activation in response to stem cell factor and diminished thrombopoietin-evoked Erk activation. Activated Kras alleviates the Ptpn11 requirement for colony formation by progenitors and cytokine/growth factor responsiveness of HSCs, indicating that Ras is functionally downstream of Shp2 in these cells. Thus, Shp2 plays a critical role in controlling the survival and maintenance of HSCs and immature progenitors in vivo.

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    • "However, their effects are non-autonomous and are rather due to their interaction with the bone marrow microenvironment (Himburg et al., 2012; Quarmyne et al., 2015). SHP2 and PRL2 are both intra-cytoplasmic phosphatases and have been shown to increase HSC self-renewal as opposed to STS1/STS2 (Chan et al., 2011; Kobayashi et al., 2014; Zhu et al., 2011). None of the phosphatases (SHP2, PRL2, "
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    ABSTRACT: FLT3 and c-KIT are crucial regulators of hematopoietic stem and progenitor cells. We investigated the role of STS1 and STS2 on FLT3 and c-KIT phosphorylation, activity, and function in normal and stress-induced hematopoiesis. STS1/STS2-deficient mice show a profound expansion of multipotent progenitor and lymphoid primed multipotent progenitor cells with elevated colony-forming capacity. Although long-term hematopoietic stem cells are not increased in numbers, lack of STS1 and STS2 significantly promotes long-term repopulation activity, demonstrating a pivotal role of STS1/STS2 in regulating hematopoietic stem and progenitor cell fitness. Biochemical analysis identified STS1/STS2 as direct phosphatases of FLT3 and c-KIT. Loss of STS1/STS2 induces hyperphosphorylation of FLT3, enhances AKT signaling, and confers a strong proliferative advantage. Therefore, our study reveals that STS1 and STS2 may serve as novel pharmaceutical targets to improve hematopoietic recovery after bone marrow transplantation.
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    • "Deletion of a conditional allele of Ptpn11 in murine hematopoietic cells causes profound bone marrow (BM) aplasia, rapid loss of hematopoietic stem cells (HSC) and multi-lineage progenitors, pancytopenia and early lethality [5], [6]. Conversely, expression of leukemogenic alleles of Ptpn11, such as Ptpn11D61Y [7] or Ptpn11E76K [8], in the hematopoietic compartment results in a fatal myeloproliferative neoplasm (MPN), featuring leukocytosis, anemia and hepatosplenomegaly. "
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    ABSTRACT: Src homology 2 (SH2) domain-containing phosphatase 2 (SHP2), encoded by PTPN11, regulates signaling networks and cell fate in many tissues. Expression of oncogenic PTPN11 in the hematopoietic compartment causes myeloproliferative neoplasm (MPN) in humans and mice. However, the stage-specific effect(s) of mutant Ptpn11 on erythroid development have remained unknown. We found that expression of an activated, leukemogenic Ptpn11 allele, Ptpn11D61Y, specifically in the erythroid lineage causes dyserythropoiesis in mice. Ptpn11D61Y progenitors produce excess cKIT+CD71+Ter119- cells and aberrant numbers of cKITl°CD71+ erythroblasts. Mutant erythroblasts show elevated activation of ERK, AKT and STAT3 in response to EPO stimulation, and MEK inhibitor treatment blocks Ptpn11D61Y-evoked erythroid hyperproliferation in vitro. Thus, the expression of oncogenic Ptpn11 causes dyserythropoiesis in a cell-autonomous manner in vivo.
    Full-text · Article · Oct 2014 · PLoS ONE
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    • "SHP2 expression levels are elevated in AML and are related to the hyperproliferative capacity and the degree of differentiation of primary leukemia cells (8). Animal models lacking SHP2 expression in hematopoietic tissues presented peripheral blood and bone marrow cytopenia (9,10), in addition to increased apoptosis and a reduced quiescence and repopulation capacity of hematopoietic stem cells (10). SHP2 knockdown in normal human cord blood CD34+ cells strongly inhibited cell survival, proliferation, and differentiation in response to growth factor stimuli (11). "
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