title: Halofuginone inhibits phosphorylation of SMAD-2 reducing angiogenesis and leukemia burden in an acute promyelocytic leukemia mouse model.
abstract: BACKGROUND
  Halofuginone (HF) is a low-molecular-weight alkaloid that has been demonstrated to interfere with Metalloproteinase-2 (MMP-2) and Tumor Growth Factor-β (TGF-β) function and, to present antiangiogenic, antiproliferative and proapoptotic properties in several solid tumor models. Based on the fact that high levels of Vascular Endothelial Growth Factor (VEGF) and increased angiogenesis have been described in acute myeloid leukemia and associated with disease progression, we studied the in vivo effects of HF using an Acute Promyelocytic Leukemia (APL) mouse model.
  
  
  METHODS
  NOD/SCID mice were transplanted with leukemic cells from hCG-PML/RARA transgenic mice (TM) and treated with HF 150 μg/kg/day for 21 days. The leukemic infiltration and the percentage of VEGF+ cells were evaluated by morphology and flow cytometry. The effect of HF on the gene expression of several pro- and antiangiogenic factors, phosphorylation of SMAD2 and VEGF secretion was assessed in vitro using NB4 and HUVEC cells.
  
  
  RESULTS
  HF treatment resulted in hematological remission with decreased accumulation of immature cell and lower amounts of VEGF in BM of leukemic mice. In vitro, HF modulated gene expression of several pro- and antiangiogenic factors, reduced VEGF secretion and phosphorylation of SMAD2, blocking TGF-β-signaling.
  
  
  CONCLUSIONS
  Taken together, our results demonstrate that HF inhibits SMAD2 signaling and reduces leukemia growth and angiogenesis.
authors.affiliation: Hematology and Oncology Divisions of the Department of Internal Medicine, Medical School of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, 14049900, Brazil. patricia_aas@yahoo.com.br.
authors.forename: Patricia A
authors.initials: PA
authors.lastname: Assis
authors.affiliation: Hematology and Oncology Divisions of the Department of Internal Medicine, Medical School of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, 14049900, Brazil. lorenafigdo@yahoo.com.br.
authors.forename: Lorena L
authors.initials: LL
authors.lastname: De Figueiredo-Pontes
authors.affiliation: Hematology and Oncology Divisions of the Department of Internal Medicine, Medical School of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, 14049900, Brazil. asglima@hotmail.com.
authors.forename: Ana Silvia G
authors.initials: AS
authors.lastname: Lima
authors.affiliation: Hematology and Oncology Divisions of the Department of Internal Medicine, Medical School of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, 14049900, Brazil. vitor.leao.vleao@gmail.com.
authors.forename: Vitor
authors.initials: V
authors.lastname: Leão
authors.affiliation: Hematology and Oncology Divisions of the Department of Internal Medicine, Medical School of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, 14049900, Brazil. larissa_candidoa@usp.br.
authors.forename: Larissa A
authors.initials: LA
authors.lastname: Cândido
authors.affiliation: Hematology and Oncology Divisions of the Department of Internal Medicine, Medical School of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, 14049900, Brazil. cpintao@hotmail.com.
authors.forename: Carolina T
authors.initials: CT
authors.lastname: Pintão
authors.affiliation: Hematology and Oncology Divisions of the Department of Internal Medicine, Medical School of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, 14049900, Brazil. aglairbg@hotmail.com.
authors.forename: Aglair B
authors.initials: AB
authors.lastname: Garcia
authors.affiliation: Pathology Department, Medical School of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, 14049900, Brazil. fchahud@fmrp.usp.br.
authors.forename: Fabiano P
authors.initials: FP
authors.lastname: Saggioro
authors.affiliation: Hematology and Oncology Divisions of the Department of Internal Medicine, Medical School of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, 14049900, Brazil. panepucci@hemocentro.fmrp.usp.br.
authors.forename: Rodrigo A
authors.initials: RA
authors.lastname: Panepucci
authors.affiliation: Pathology Department, Medical School of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, 14049900, Brazil. fchahud@fmrp.usp.br.
authors.forename: Fernando
authors.initials: F
authors.lastname: Chahud
authors.affiliation: Hematology Division and Cord Blood Bank, Chaim Sheba Medical Center, Tel Aviv University, Tel Hashomer, 6997801, Israel. arnon.nagler@sheba.health.gov.il.
authors.forename: Arnon
authors.initials: A
authors.lastname: Nagler
authors.affiliation: Hematology and Oncology Divisions of the Department of Internal Medicine, Medical School of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, 14049900, Brazil. rpfalcao@fmrp.usp.br.
authors.forename: Roberto P
authors.initials: RP
authors.lastname: Falcão
authors.affiliation: Hematology and Oncology Divisions of the Department of Internal Medicine, Medical School of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, 14049900, Brazil. emrego@hcrp.fmrp.usp.br.
authors.forename: Eduardo M
authors.initials: EM
authors.lastname: Rego
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D006801:Humans; D016130:Immunophenotyping; D015473:Leukemia, Promyelocytic, Acute / Q000378:metabolism*; D051379:Mice; D016688:Mice, Inbred NOD; D016513:Mice, SCID; D008822:Mice, Transgenic; D009389:Neovascularization, Pathologic; D010766:Phosphorylation; D010880:Piperidines / Q000378:metabolism*; D052999:Quinazolinones / Q000378:metabolism*; D051899:Smad2 Protein / Q000235:genetics* / Q000378:metabolism; D014407:Tumor Cells, Cultured
chemical_list: D010880:Piperidines; D052999:Quinazolinones; C497782:SMAD2 protein, human; D051899:Smad2 Protein; C010176:halofuginone