Role of PI3K/Akt signaling pathway in propofol-induced invasion of human liver cancer cell line HepG2

Abstract

Objective To evaluate the role of phosphatidylinositol 3-kinase(PI3K)/serine-threonine kinase(Akt)signaling pathway in propofol-induced invasion of human liver cancer cell line HepG2. Methods HepG2 cells were cultured in RPMI 1640 medium supplemented with 10% fetal bovine serum in a 5% CO2 incubator at 37 ℃.HepG2 cells at the logarithmic growth phase were divided into 6 groups(n=18 each)using a random number table: control group(group C), propofol group(group P), PI3K/Akt signaling pathway agonist IGF-1 group(group IGF), PI3K/Akt signaling pathway inhibitor LY294002 group(group LY), IGF-1 plus propofol group(group IGF+ P)and LY294002 plus propofol group(group LY + P). Propofol 120 μg/ml was added in group P. IGF-1 10 nmol/L was added in group IGF.LY294002 10 μmol was added in group LY.In group IGF+ P, 10 nmol/L IGF-1 was added, cells were incubated for 24 h, and then 120 μg/ml propofol was added.In group LY + P, 10 μmol LY294002 was added, cells were incubated for 24 h, and then 120 μg/ml propofol was added.The invasion of cells was measured by Transwell invasion assay at 24 h of incubation.The expression of PI3K and Akt mRNA in cells was determined by real-time polymerase chain reaction.The expression of Akt, PI3K and phosphorylated Akt(p-Akt)was detected by using Western blot. Results Compared with group C, the invasive cell count was significantly reduced, the expression of PI3K protein and mRNA was down-regulated, p-Akt/Akt ratio was decreased, and the expression of Akt mRNA was down-regulated in P, P+ IGF, LY and P+ LY groups, and the invasive cell count was significantly increased, the expression of PI3K protein and mRNA was up-regulated, p-Akt/Akt ratio was increased, and the expression of Akt mRNA was up-regulated in group IGF(P<0.05). Compared with group P, the invasive cell count was significantly increased, the expression of PI3K protein and mRNA was up-regulated, p-Akt/Akt ratio was increased, and the expression of Akt mRNA was up-regulated in group P+ IGF, and the invasive cell count was significantly reduced, the expression of PI3K protein and mRNA was down-regulated, p-Akt/Akt ratio was decreased, and the expression of Akt mRNA was down-regulated in group P+ LY(P<0.05). The invasive cell count was significantly reduced, the expression of PI3K protein and mRNA was down-regulated, p-Akt/Akt ratio was decreased, and the expression of Akt mRNA was down-regulated in group P+ IGF as compared with group IGF(P<0.05)and in group P+ LY as compared with group LY(P<0.05). Conclusion The mechanism by which propofol inhibits invasion of HepG2 cells is related to inhibiting activation of PI3K/Akt signaling pathways. Key words: Propofol; Cell line, tumor; Neoplasm invasiveness; 1-Phosphatidylinositol 3-kinase; Protein-serine-threonine kinases