p21-activated kinase 4 promotes proliferation, migration, and invasion of human gastric cancer cells

Background/Aim: p21-activated kinase 4 (PAK4) overexpression has been observed in many cancers, including metastatic gastric cancer (GC). However, the precise role of PAK4 in GC remains unclarified. The aim of this study was to elucidate the role of PAK4 in GC development and progression. Methods: PAK4 was knocked down in MKN-28 cells using RNA interference (RNAi). Stable transfection of MKN-45 cells with PAK4 vector was used in overexpression experiments. PAK4 mRNA and protein levels were detected by qPCR and Western blot. PAK4 influence on cell proliferation, clone formation, migration, and invasion were evaluated. Results: PAK4 downregulation inhibited cell growth, clonogenicity, migration, and invasion, while PAK4 overexpression resulted in increased cell proliferation, migration, and invasion. Moreover, PAK4 regulated activation of the c-Src/EGFR/cyclin D1 and MEK-1/ERK1/2/MMP2 pathways. Conclusion: PAK4 overexpression promotes proliferation, migration, and invasion of GC cells and thus its down-regulation might be used as new strategy for GC treatment.