Effect of inhibition of Akt phosphorylation on apoptosis of non-small cell lung cancer H1299 cells with wild type EGFR and KRAS induced by tumor necrosis factor related apoptosis inducing ligand / 肿瘤研究与临床

ABSTRACT

Objective To explore the effect of inhibiting Akt phosphorylation on tumor necrosis factor related apoptosis inducing ligand (TRAIL)-induced apoptosis of human non-small cell lung cancer (NSCLC) H1299 cells with wild type EGFR and KRAS.Methods The TRAIL-induced apoptosis was examined by the Annexin V-FITC/PI.The expressions of TRAIL-activated Akt phosphorylation and p-Akt were measured by Western blot.After cells were treated with LY294002, an inhibitor of PI3K-Akt pathway, Annexin V-FITC/PI and Western blot were used to analyze the alteration of TRAIL-induced apoptosis and Akt phosphorylation, respectively.Results H1299 cells were not sensitive to TRAIL-induced apoptosis.When TRAIL concentration was 100 ng/ml, the apoptosis rate of the test group was significantly higher than that of the control group [(15.06±1.29) ％ vs (3.56±0.50) ％, t =66.953, P =0.000].When TRAIL concentration was 500 ng/ml, the difference was not statistically significant compared with apoptosis rate of 100 ng/ml TRAIL group [(18.65±2.09) ％ vs (15.06±1.29) ％, t =2.423, P =0.136].The expression level of Akt phosphorylation in H1299 cells was increased by TRAIL in a time-dependent way.When cells were pretreated with LY294002, TRAIL-induced Akt phosphorylation was suppressed to baseline level.At the same time, the apoptosis rate in LY294002-treated group was significantly higher than that in TRAIL group [(41.65±4.62) ％ vs (15.82±0.61) ％, t =39.028, P =0.001].Conclusions TRAIL-induced Akt phosphorylation can antagonize TRAIL-induced apoptosis.Inhibition of Akt phosphorylation can significantly enhance the sensitivity of NSCLC H1299 cells with wild type EGFR and KRAS to TRAIL-induced apoptosis.