title: Defective differentiation of myeloid and plasmacytoid dendritic cells in advanced cancer patients is not normalized by tyrosine kinase inhibition of the vascular endothelial growth factor receptor.
abstract: Tumor-derived vascular endothelial growth factor (VEGF) has previously been identified as a causative factor in the disturbed differentiation of myeloid dendritic cells (DC) in advanced cancer patients. Here, we investigated the potential of vascular endothelial growth factor receptor (VEGFR) tyrosine kinase (TK) inhibition to overcome this defective DC differentiation. To this end, peripheral blood DC (PBDC) precursor and subset frequencies were measured in 13 patients with advanced cancer before and after treatment with AZD2171, a TK inhibitor (TKI) of VEGFR, coadministered with gefitinib, and an epidermal growth factor receptor (EGFR) TKI. Of note, not only myeloid DC but also plasmacytoid DC frequencies were significantly reduced in the blood of the cancer patients prior to treatment, as compared to healthy controls. Moreover, besides an accumulated population of immature myeloid cells (ImC), a population of myeloid suppressor cells (MSC) was significantly increased. Upon systemic VEGFR TK inhibition, DC frequencies did not increase, whereas the rate of circulating MSC showed a slight, but not significant, decrease. In conclusion, TK inhibition of VEGFR with AZD2171 does not restore the defective PBDC differentiation observed in advanced cancer patients.
authors.affiliation: Department of Medical Oncology, VU University Medical Center, De Boelelaan 1117, 1081 HV Amsterdam, The Netherlands. h.vancruijsen@vumc.nl
authors.forename: H
authors.initials: H
authors.lastname: van Cruijsen
authors.forename: K
authors.initials: K
authors.lastname: Hoekman
authors.forename: A G M
authors.initials: AG
authors.lastname: Stam
authors.forename: A J M
authors.initials: AJ
authors.lastname: van den Eertwegh
authors.forename: B C
authors.initials: BC
authors.lastname: Kuenen
authors.forename: R J
authors.initials: RJ
authors.lastname: Scheper
authors.forename: G
authors.initials: G
authors.lastname: Giaccone
authors.forename: T D
authors.initials: TD
authors.lastname: de Gruijl
mesh_terms: D000328:Adult; D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols; D002454:Cell Differentiation / Q000187:drug effects*; D003713:Dendritic Cells / Q000166:cytology / Q000187:drug effects* / Q000276:immunology; D005260:Female; D005434:Flow Cytometry; D000077156:Gefitinib; D006801:Humans; D008297:Male; D008875:Middle Aged; D022423:Myeloid Cells / Q000166:cytology / Q000187:drug effects / Q000276:immunology; D009369:Neoplasms / Q000188:drug therapy*; D047428:Protein Kinase Inhibitors / Q000627:therapeutic use*; D011799:Quinazolines / Q000008:administration & dosage / Q000627:therapeutic use*; D040262:Receptors, Vascular Endothelial Growth Factor / Q000037:antagonists & inhibitors / Q000097:blood / Q000187:drug effects*; D007211:Indoles
chemical_list: D000077156:Gefitinib; D047428:Protein Kinase Inhibitors; D011799:Quinazolines; D040262:Receptors, Vascular Endothelial Growth Factor; C500926:cediranib; D007211:Indoles