Gefitinib accumulation in glioblastoma tissue.
Therapeutic agents for brain tumors confront multiple physical and metabolic hurdles. These include the blood brain barrier (BBB), vascular and interstitial barriers, clearing by MDR1 and other ABC transporter proteins, and drug catabolism. Here, we report an accumulation of gefitinib in glioblastoma (GBM) tissue to over a dozen times plasma levels, and propose that some mechanisms converge to achieve such accumulation: (1) small molecular size of gefitinib facilitates access by diffusion; (2) its high water solubility enables thermodynamic retention inside malignant cells; and (3) low CYP3A4 activity in GBM tissue, the main enzyme for gefitinib catabolism, prevents metabolic elimination. Our data confirm the capacity of gefitinib to accumulate in solid human tumors in vivo.
Department of Oncology, Zurich University Hospital, Zürich, Switzerland. silvia.hofer@usz.ch
Silvia
S
Hofer
Karl
K
Frei
Hans Peter
HP
Rutz
D000970:Antineoplastic Agents / Q000627:therapeutic use; D001932:Brain Neoplasms / Q000188:drug therapy / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D051544:Cytochrome P-450 CYP3A; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism; D066246:ErbB Receptors / Q000037:antagonists & inhibitors; D000077156:Gefitinib; D005909:Glioblastoma / Q000188:drug therapy / Q000378:metabolism*; D006801:Humans; D013058:Mass Spectrometry; D011799:Quinazolines / Q000378:metabolism* / Q000627:therapeutic use
D000970:Antineoplastic Agents; D011799:Quinazolines; D003577:Cytochrome P-450 Enzyme System; D051544:Cytochrome P-450 CYP3A; C510163:CYP3A4 protein, human; D066246:ErbB Receptors; D000077156:Gefitinib