Assessment of epidermal growth factor receptor status in glioblastomas

A B S T R A C T Objective(s): O ur previous study showed that a newly designed tracer radioiodinated 6‐(3‐morpholinopropoxy)‐7‐ethoxy‐4‐(3'‐ iodophenoxy)quinazoline ([125I]PYK) is promising for the evaluation of the epidermal growth factor receptor (EGFR) status and prediction of gefitinib treatment of non‐small cell lung cancer. EGFR is over‐expressed and mutated also in glioblastoma. In the present study, the expressions and mutation of EGFR were tested with [ 125 I] PYK in glioblastoma in vitro and in vivo to determine whether this could be used to predict the sensitivity of glioblastoma to gefitinib treatment. Methods: Glioblastoma cell lines with different expression of EGFR were tested. Growth inhibition of cell lines by gefitinib was assessed by the 3‐(4, 5‐dimethylthiazol‐2‐yl)‐2, 5‐ diphenyltetrazolium bromide (MTT) colorimetric assay. Uptake levels of [ 125 I]PYK were evaluated in cell lines in vitro. Tumor targeting of [ 125 I]PYK was examined by a biodistribution study and