Oussama Karroum1, Julie Kengen1,
1Louvrain Drug Research Institute, Biomedical Magnetic Resonance Group, Universite Catholique de Louvain, Brussels, Belgium; 2Louvrain Drug Research Institute, Pharmacokinetics, Metabolism, Nutrition, & Toxicology Group, Universite Catholique de Louvain; 3IREC, Pole of Pharmacology & Therapeutics, Universite Catholique de Louvain; 4IREC, Molecular Imaging & Radiotherapy, Universite Catholique de Louvain
The effects of different MAPKinase inhibitors (Sorafenib, Gefitinib, FTS, and PD-0325901) were monitored in FSaII experimental mouse tumors. In vivo EPR oximetry (L-band) showed an increase in tumor pO2 for all MAPK inhibitors and allowed the identification of a window of reoxygenation, which was further exploited for improving radiation response. The increase in tumor oxygenation was shown to be the result of two major factors: (i) an increase in blood flow for sorafenib only and, (ii) a decrease in oxygen consumption for all MAPK inhibitors, as measured ex vivo using X-band EPR oximetry.