The VEGFA-Induced MAPK-AKT/PTEN/TGFβ Signal Pathway Enhances Progression and MDR in Gastric Cancer

Background/Objectives: Gastric cancer (GC) is a globally frequent cancer, in particular leading in mortality caused by digestive tract cancers in China. Vascular endothelial growth factor A (VEGFA) is excessively expressed in cancers including GC; its involvement in GC development, particularly in multidrug resistance (MDR), and the signal route it affects in GC remain unknown. To explore the roles VEGFA plays during progression and MDR formation in GC, we studied its function in a VEGFA-deleted GC cell platform. Methods: We initially assessed the importance of VEGFA in GC and MDR using database analysis. Then, using CCK8, wound healing, transwell, scanning electron microscopy, immunofluorescence, flow cytometry, and other techniques, the alterations in tumor malignancy-connected cell behaviors and microstructures were photographed and evaluated in a VEGFA-gene-deleted GC cell line (VEGFA−/−SGC7901). Finally, the mechanism of VEGFA in GC progression and MDR was examined by Western blot. Results: Database analysis revealed a strong correlation between high VEGFA expression and a poor prognosis for GC. The results showed that VEGFA deletion reduced GC cell proliferation and motility and altered microstructures important for motility, such as the depolymerized cytoskeleton. VEGFA deletion inhibited the growth of pseudopodia/filopodia and suppressed the epithelial–mesenchymal transition (EMT). The occurrence of MDR is induced by overactivation of the MAPK-AKT and TGFβ signaling pathways, while PTEN inhibits these pathways. Conclusions: All findings suggested that VEGFA acts as a cancer enhancer and MDR inducer in GC via the MAPK-AKT/PTEN/TGFβ signal pathway.