Figure 3.

Schematic representation of proliferating cell with activated PI3K/AKT/mTOR pathway. The ribosomal S6 protein is phosphorylated (+p) when the PI3K/AKT/mTOR pathway is activated, resulting in translation and degradation of GAS5 by the NMD pathway. Downregulation of GAS5 causes an increase in c-Myc protein, thereby facilitating cell cycle progression via inducing activation of cyclin-CDK complexes. PTEN, a tumor suppressor protein, blocks the PI3K/AKT/mTOR signaling pathway by dephosphorylating (−p) PIP3.