title: Anti-vascular endothelial growth factor treatment in combination with chemotherapy delays hematopoietic recovery due to decreased proliferation of bone marrow hematopoietic progenitor cells.
abstract: BACKGROUND
  Targeting of cancer by chemotherapy in combination with anti-vascular endothelial growth factor (VEGF) therapy has demonstrated not only the clinical efficacy but also a higher risk of serious hematologic complications including neutropenia. The purpose of the study was to elucidate the molecular mechanisms responsible for the development of neutropenia during the combination treatment.
  
  
  METHODS
  Mouse model and in vitro studies were undertaken to determine the effect of interference with VEGF signaling by VEGF-specific agents or a multitargeted VEGF receptor (VEGFR) tyrosine kinase inhibitor on proliferation of hematopoietic progenitor cell (HPC) and repopulation of the hematopoietic compartment after myeloablation.
  
  
  RESULTS
  The studies demonstrated that blockage of VEGFR1 or VEGFR2 signaling decreased HPC proliferation and impaired repopulation of the hematopoietic compartment after myelosuppression by slowing the progression of HPC through the cell cycle. The combination of cytotoxic drugs and VEGFR tyrosine kinase inhibitor had an additive inhibitory effect and decreased proliferation of HPC significantly stronger than either agent alone.
  
  
  CONCLUSIONS
  Signaling through both VEGFR1 and VEGFR2 is required for normal reconstitution of the hematopoietic compartment after cytotoxic chemotherapy.
authors.affiliation: Division of Hematology/Oncology, Department of Medicine, Vanderbilt-Ingram Cancer Center, Vanderbilt University, 220 Pierce Avenue, Nashville, TN 37232, USA.
authors.forename: Sergey V
authors.initials: SV
authors.lastname: Novitskiy
authors.forename: Ildiko
authors.initials: I
authors.lastname: Csiki
authors.forename: Yuhui
authors.initials: Y
authors.lastname: Huang
authors.forename: David H
authors.initials: DH
authors.lastname: Johnson
authors.forename: Eva M
authors.initials: EM
authors.lastname: Harth
authors.forename: David P
authors.initials: DP
authors.lastname: Carbone
authors.forename: Mikhail M
authors.initials: MM
authors.lastname: Dikov
mesh_terms: D020533:Angiogenesis Inhibitors / Q000627:therapeutic use*; D000818:Animals; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D015153:Blotting, Western; D001853:Bone Marrow / Q000187:drug effects*; D002453:Cell Cycle / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects*; D005260:Female; D005434:Flow Cytometry; D005472:Fluorouracil / Q000008:administration & dosage; D006412:Hematopoietic Stem Cells / Q000378:metabolism / Q000473:pathology*; D006413:Hematopoietic System / Q000187:drug effects* / Q000502:physiology; D007211:Indoles / Q000008:administration & dosage; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008817:Mice, Mutant Strains; D011758:Pyrroles / Q000008:administration & dosage; D015398:Signal Transduction / Q000187:drug effects; D015996:Survival Rate; D016896:Treatment Outcome; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism; D040281:Vascular Endothelial Growth Factor Receptor-1 / Q000037:antagonists & inhibitors*; D040301:Vascular Endothelial Growth Factor Receptor-2 / Q000037:antagonists & inhibitors*
chemical_list: D020533:Angiogenesis Inhibitors; D007211:Indoles; D011758:Pyrroles; D042461:Vascular Endothelial Growth Factor A; C116890:Semaxinib; D040281:Vascular Endothelial Growth Factor Receptor-1; D040301:Vascular Endothelial Growth Factor Receptor-2; D005472:Fluorouracil