title: SHP2 tyrosine phosphatase stimulates CEBPA gene expression to mediate cytokine-dependent granulopoiesis.
abstract: G-CSF signals contribute to granulocyte lineage specification. We previously found that G-CSF induces SHP2 tyrosine phosphorylation and that chemical inhibition of SHP1/SHP2 reduces CFU-G and prevents G-CSF but not M-CSF activation of ERK. We now find that SHP2 shRNA knockdown in the 32Dcl3 granulocytic line reduces ERK activation, diminishes CEBPA protein and RNA expression and promoter histone acetylation, and inhibits granulopoiesis. Exogenous, shRNA-resistant SHP2 rescues these effects of SHP2 knockdown, exogenous C/EBPα rescues granulocytic markers, and exogenous RUNX1 rescues C/EBPα. 32Dcl3 lines with knockdown of ERK1 and ERK2 retain normal levels of C/EBPα and differentiate normally in G-CSF despite also having reduced proliferation. SHP2 knockdown reduces CEBPA levels in lineage-negative murine marrow cells cultured in TPO, Flt3 ligand, and SCF, without affecting the rate of cell expansion. On transfer to IL-3, IL-6, and SCF to induce myelopoiesis, levels of granulocytic RNAs are reduced and monocyte-specific RNAs are increased by SHP2 knockdown, and there is a reduction in the percentage of CFU-G that form in methylcellulose and of granulocytes that develop in liquid culture. In summary, SHP2 is required for induction of C/EBPα expression and granulopoiesis in response to G-CSF or other cytokines independent of SHP2-mediated ERK activation.
authors: Division of Pediatric Oncology, Johns Hopkins University, Baltimore, MD, USA.
authors: Li
authors: L
authors: Zhang
authors: Alan D
authors: AD
authors: Friedman
mesh_terms: D000818:Animals; D001483:Base Sequence; D022762:CCAAT-Enhancer-Binding Proteins / Q000235:genetics*; D002460:Cell Line; D003114:Colony-Forming Units Assay; D050676:Core Binding Factor Alpha 2 Subunit / Q000494:pharmacology; D016207:Cytokines / Q000494:pharmacology; D005260:Female; D015870:Gene Expression; D055785:Gene Knockdown Techniques; D016179:Granulocyte Colony-Stimulating Factor / Q000494:pharmacology; D006098:Granulocytes / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D020935:MAP Kinase Signaling System; D051379:Mice; D008810:Mice, Inbred C57BL; D038042:Myelopoiesis / Q000187:drug effects / Q000235:genetics* / Q000502:physiology*; D054592:Protein Tyrosine Phosphatase, Non-Receptor Type 11 / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism* / Q000494:pharmacology; D034741:RNA, Small Interfering / Q000235:genetics; D011994:Recombinant Proteins
chemical_list: D022762:CCAAT-Enhancer-Binding Proteins; C530718:CEBPA protein, mouse; D050676:Core Binding Factor Alpha 2 Subunit; D016207:Cytokines; D034741:RNA, Small Interfering; D011994:Recombinant Proteins; C493726:Runx1 protein, mouse; D016179:Granulocyte Colony-Stimulating Factor; D054592:Protein Tyrosine Phosphatase, Non-Receptor Type 11; C516725:Ptpn11 protein, mouse