GAS1 regulates SF proliferation and apoptosis through the PI3K-Akt pathway. (A) Representative blots demonstrating the expression of GAS1 and proteins associated with the PI3K/Akt pathway and apoptosis (PI3K, p-Akt, total Akt, Cdk2 and Bax) from non-OASFs transfected with siRNA-GAS1, siRNA-NC or cells transfected with siRNA-GAS1 + LY (50 µM) treatment. (B) Representative blots demonstrating the expression of GAS1 and proteins associated with the PI3K/Akt pathway and apoptosis (PI3K, p-Akt, total Akt, Cdk2 and Bax) from non-OASFs transfected with pcDNA-vector or pcDNA-GAS. (C) Quantification of densitometric data and Akt phosphorylation. *P<0.01 and **P<0.001. SF, synovial fibroblasts; OASFs, osteoarthritis synovial fibroblasts; p-Akt, phosphorylated Akt; Cdk2, cyclin-dependent kinase 2; GAS1, growth arrest specific-1; NC, negative control; siRNA, small interfering RNA; LY, LY294002.