Fig. 6

FAT4 regulates autophagy and the EMT by regulating the level of PI3K. a-c The levels of various factors in cells transduced with a target gene or negative control and treated with either the PI3K inhibitor wortmannin or the PI3K activator 740Y-P were examined by western blotting. The treatment of FAT4-overexpressing cells with 740Y-P increased the expression of PI3K, p-AKT, mTOR, β-catenin and p-GSK-3β but decreased the expression of GSK-3β. In these cells, the LC3-II/LC3-I ratio, which is used as an autophagy marker, was reduced, and P62 expression was increased; these changes result in the inhibition of autophagy. The treatment of sh-FAT4 SW480 cells with the PI3K inhibitor wortmannin reduced the expression of PI3K, p-AKT, mTOR, β-catenin and p-GSK-3β, increased the expression of GSK-3β and LC3-II/LC3-I ratio, and decreased the expression of P62. *P < 0.05, as determined by Student’s t-test