Relationship between uptake of a radioiodinated quinazoline derivative and radiosensitivity in non-small cell lung cancer

The aim of this study was to determine whether the uptake of radioiodinated 6-(3-morpholinopropoxy)-7-ethoxy-4-(3'-iodophenoxy) quinazoline ([(125)I]PYK) could predict the response of non-small cell lung cancer (NSCLC) cells to radiotherapy in vitro. Four NSCLC cell lines, PC9, HCC827, A549, and H1975 were used. Cells were irradiated with doses ranging from 2 Gy to 8 Gy and/or exposed to 1 μM gefitinib. The effects of radiation and gefitinib were assessed by the CCK-8 assay and confirmed by reverse transcription-polymerase chain reaction and immunoflorescence microscopy. The uptake of [(125)I]PYK was determined by incubating cells with a tracer. The cell cycle was assessed by flow cytometry. The expression of EGFR was measured by western blotting. The results obtained revealed that the uptake of [(125)I]PYK was higher in PC9 and HCC827 cells than in A549 and H1975 cells. PC9 cells and HCC827 cells were also more radiosensitive than A549 and H1975 cells. The gefitinib pretreatment reduced the S phase fraction and enhanced radiation effects in PC9 and HCC827 cells. These results indicate that the uptake of [(125)I]PYK is related to the effects of radiation in NSCLC cells. Radioiodinated PYK may be useful in predicting the response of NSCLC in patients to radiotherapy.