Overexpression of BRCA1 attenuates the sensitivity of PC9 cells to gefitinib.

Gefitinib is an orally active antitumor agent which inhibits uncontrolled cell proliferation by interrupting epidermal growth factor receptor (EGFR) signaling pathways. Various in vitro and in vivo studies have revealed that the upregulated expression of breast cancer susceptibility gene 1 (BRCA1) is associated with chemoresistance and reduced survival following chemotherapies. In this study, a gefitinib-highly-sensitive cell line, PC-9, was used to investigate the effect of BRCA1 expression on the sensitivity of PC-9 cells to gefitinib.