A dual PI3K/mTOR inhibitor, PI-103, cooperates with TRAIL in laryngeal squamous carcinoma cells in vitro

Abstract

To investigate the effects of a dual phosphoinosmde-3-kinase (PI3K)/ mammalian target of rapamycin (mTOR) inhibitor, PI-103, cooperating with tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) on the laryngeal squamous carcinoma Hep-2 cells. Hep-2 cells were divided into 7 groups: LY294002 group, Rapamycin group, PI-103 group, LY294002+ TRAIL group, Rapamycin+ TRAIL group, PI-103+ TRAIL group and control group.The cell cycle and apoptosis of Hep-2 cells were assessed by flow cytometry.For PI-103 group, PI-103+ TRAIL group and control group, migration and invasion ability were measured by transwell migration and invasion assay respectively.The expression of relative proteins in apoptosis and PI3K/AKT/mTOR signal pathway was examined by Western blotting. Combination of PI-103 and TRAIL could make cell cycle arrest at S phase (G1: 1.80%±0.30%; G2: 0.00), inhibit cell proliferation, and enhance apoptosis (66.78%±2.93%) (P<0.05). Combination of PI-103 and TRAIL could statistically decrease the migration and invasion number of Hep-2 cells (17.0±3.4, 18.4±5.4) than that of PI-103 group (41.2±3.8, 41.6±4.7). PI-103 could inhibit PI3K/AKT/mTOR signal pathway by decreasing the protein expression of p-AKT and p-4E-BP1.Comparing with the control group, the expression of cysteinyl aspartate specific proteinase (Caspase) 9, 8, 3 were increased while the expression of Cyclin D1, Cyclin E1, p-AKT, p-4E-BP1 were decreased in PI-103 and PI-103+ TRAIL group (P<0.05). Enhanced anti-tumor effects was observed by combination of PI-103 and TRAIL on laryngeal cancer cells in vitro and this combined administration might be a promising strategy for clinical treatment of laryngeal cancer.