High levels of the imprinted gene pleckstrin homology like domain family A member 2 (PHLDA2) correlate with tumor progression in several malignancies. Here, we investigated the effects of PHDLDA2 expression in CRC through assays of cellular proliferation, invasion, migration, and apoptosis. We also screened for possible mechanisms of action. Our results show that PHLDA2 was upregulated in CRC tissues. Knockdown of PHLDA2 inhibited cellular proliferation, invasion, migration, and epithelial-mesenchymal transition (EMT) in vitro. Knockout of PHLDA2 promoted cellular apoptosis, in part by activating autophagy. PHLDA2 knockout also inhibited tumorigenesis and expression of KI67 protein in vivo. The effects of PHLDA2 on autophagy and EMT were mediated in part via the PI3K/AKT signaling pathway. Taken together, these results suggest that downregulation of PHLDA2 inhibits tumor growth and PI3K, thereby promoting autophagy and inhibiting EMT, in part through the PI3K/AKT/mTOR and PI3K/AKT/GSK-3β signaling pathways.
Keywords: PHLDA2; apoptosis; autophagy; colorectal cancer; tumorigenesis.