PABPC1 Silencing Inhibits Gastric Cancer Cell Proliferation, Metastasis, and EMT Via the PI3K/AKT Pathway.

[UNLABELLED] Gastric cancer is associated with high morbidity and mortality rates and seriously threatens human life. Our research aimed to explore the effects of poly (A) binding protein cytoplasmic 1 (PABPC1) on gastric cancer cells and elucidate the underlying mechanisms.

[METHODS] PABPC1 levels in gastric cancer cell lines were assessed by western blotting and RT-qPCR. Cell viability, apoptosis, invasion, and migration were analyzed using MTT assay, flow cytometry, wound healing assay, and transwell assay, respectively. The levels of apoptosis-related proteins (caspase 3 and cleaved-caspase 3) were determined using the caspase 3 vitality test kit and western blotting. The levels of epithelial-to-mesenchymal transition-related genes (E-cadherin and N-cadherin) in AGS and MGC803 cells were analyzed using western blotting and RT-qPCR. The phosphatidylinositol 3-kinase (PI3K)/AKT pathway was examined using western blot analysis.

[RESULTS] PABPC1 expression was enhanced in gastric cancer cells, especially in AGS and MGC803 cells. Our findings indicate that PABPC1 knockdown by siRNA inhibited PABPC1 expression, repressed gastric cancer cell growth, promoted apoptosis, and enhanced cleaved-caspase 3 expression. Functional assays revealed that PABPC1-siRNA blocked the migration and invasion of gastric cancer cells, dramatically promoted E-cadherin expression, and reduced N-cadherin levels. We also found decreased p-PI3K and p-AKT expression, along with decreased p-PI3K/PI3K and p-AKT/AKT in PABPC1-siRNA-treated gastric cancer cells.

[CONCLUSION] PABPC1 silencing in gastric cancer cells inhibited cell proliferation, metastasis, and epithelial-to-mesenchymal transition, partly by repressing the PI3K/AKT signaling pathway activation. This may provide a theoretical basis for gastric cancer therapeutics.