In vitro anticancer activity of PI3K alpha selective inhibitor BYL719 in head and neck cancer.

The purpose of the present study was to explore the antiproliferative effect of BYL719, a specific inhibitor for phosphatidylinositol 3-kinase (PI3K) p110α, in human head and neck cancer cell lines, as a single agent or in combination with the irreversible EGFR tyrosine kinase inhibitor, dacomitinib. Six head and neck cancer cell lines consisting of two PIK3CA mutant cell lines, SNU-1076 and Detroit562, and four PIK3CA wild-type cell lines, SNU-1066, SNU-1041, FaDu and SCC25, were analyzed. The PIK3CA-mutant cell lines were more sensitive to BYL719 than the PIK3CA wild-type cell lines. Following BYL719 treatment, all PIK3CA wild-type cell lines, except for the SNU-1066 cell line, exhibited higher IC50 values compared to the PIK3CA mutant cell lines. Administration of BYL719 induced cell cycle G0/G1 arrest and resulted in increased apoptosis in a dose-dependant manner. Furthermore, the administration of BYL719 reduced the level of p-mTOR, p-AKT and p-S6 expression indicating the down-regulation of downstream signaling. BYL719, a PI3K alpha selective blocker, could be a promising factor in the treatment of head and neck cancer either as a single agent or in combination with dacomitinib.