Effect of PDK1 on biological characteristics of lung cancer A549 cells / 中国病理生理杂志

ABSTRACT

AIM:To investigate the effects of 3-phosphoinositide-dependent protein-1(PDK1)on the biologi-cal characteristics of non-small-cell lung cancer cell line A549 and the underlying mechanisms.METHODS:The expres-sion levels of PDK1 in lung normal epithelial cell line BEAS-2B and different lung cancer cell lines H 460, SPCA1 and A549 were determined by Western blot and real-time PCR.Small interfering RNA was used to down-regulated PDK1 ex-pression in the A549 cells,and then cell viability and apoptosis were measured by CCK-8 assay and flow cytometry,respec-tively.The expression of cell cycle-and apoptosis-related molecules at protein level and the activation of Akt /FoxO1 path-way were measured by Western blot.Insulin-like growth factor-1(IGF-1,one of the most potent Akt activators)was used to evaluate the interaction between PDK 1 and Akt/FoxO1 pathway.RESULTS:Compared with lung normal epithelial cell line BEAS-2B,PDK1 expression in the lung cancer cell lines was obviously increased(P<0.05).Knockdown of PDK1 suppressed cell viability and cell cycle,but promoted the apoptosis of the A 549 cells.The results of Western blot showed that the protein levels of cyclin D1,CDK4,p-Rb,Bcl-2,p-Akt and cytoplasmic p-FoxO1 were significantly decreased after knockdown of PDK1,with increases in the protein levels of P27, cleaved caspase-3 and nuclear FoxO1.Pre-incubation with IGF-1 partly reversed the effect of PDK1 knockdown on Akt/FoxO1 pathway and increased the viability of A 549 cells. CONCLUSION:In human non-small-cell lung cancer A549 cells,knockdown of PDK1 suppresses cell viability and pro-motes cell apoptosis by regulating the expression of cell cycle-and apoptosis-related molecules via Akt/FoxO1 pathway, suggesting that PDK1 may be a potential target for diagnosis and theatment of lung cancer.