title: Tumor reoxygenation following administration of the EGFR inhibitor, gefitinib, in experimental tumors.
abstract: It is well recognized that tumor hypoxia is a critical determinant for response to therapy. The effect of an EGFR inhibitor/gefitinib (Iressa®) on tumor oxygenation was monitored daily using in vivo EPR (electron paramagnetic resonance) oximetry on TLT and FSaII tumor models. An increase in pO2 was shown at a dose of 45 mg/kg i.p. (n = 4/group/tumor model). This allowed the identification of a window of reoxygenation in both tumor models (with a maximum between 15 and 20 mmHg after 2 days of treatment). The increase in tumor oxygenation was shown to be the result of a decrease in oxygen consumption. This is the first report on the effect of gefitinib on oxygen consumption by tumor cells and subsequent increase in tumor oxygenation in vivo.
authors.affiliation: Biomedical Magnetic Resonance Group, Louvain Drug Research Institute, Université catholique de Louvain, Av.Mounier 73.40, 1200, Brussels, Belgium.
authors.forename: Oussama
authors.initials: O
authors.lastname: Karroum
authors.affiliation: Biomedical Magnetic Resonance Group, Louvain Drug Research Institute, Université catholique de Louvain, Av.Mounier 73.40, 1200, Brussels, Belgium.
authors.forename: Julie
authors.initials: J
authors.lastname: Kengen
authors.affiliation: Pole of Molecular Imaging, Radiotherapy and Oncology, Université catholique de Louvain, Brussels, Belgium.
authors.forename: Vincent
authors.initials: V
authors.lastname: Grégoire
authors.affiliation: Biomedical Magnetic Resonance Group, Louvain Drug Research Institute, Université catholique de Louvain, Av.Mounier 73.40, 1200, Brussels, Belgium.
authors.forename: Bernard
authors.initials: B
authors.lastname: Gallez
authors.affiliation: Biomedical Magnetic Resonance Group, Louvain Drug Research Institute, Université catholique de Louvain, Av.Mounier 73.40, 1200, Brussels, Belgium. Benedicte.jordan@uclouvain.be.
authors.forename: Bénédicte F
authors.initials: BF
authors.lastname: Jordan
mesh_terms: D000818:Animals; D015687:Cell Hypoxia / Q000187:drug effects / Q000502:physiology; D004578:Electron Spin Resonance Spectroscopy / Q000379:methods; D066246:ErbB Receptors / Q000037:antagonists & inhibitors* / Q000378:metabolism; D005354:Fibrosarcoma / Q000188:drug therapy / Q000378:metabolism; D000077156:Gefitinib; D008114:Liver Neoplasms, Experimental / Q000188:drug therapy* / Q000378:metabolism; D051379:Mice; D008809:Mice, Inbred C3H; D010092:Oximetry / Q000379:methods; D010100:Oxygen / Q000378:metabolism*; D010101:Oxygen Consumption / Q000187:drug effects* / Q000502:physiology; D011799:Quinazolines / Q000494:pharmacology*
chemical_list: D011799:Quinazolines; D066246:ErbB Receptors; D000077156:Gefitinib; D010100:Oxygen