Plantamajoside Reduces Gastric Cancer Cell Migration and Invasion by Inhibiting PI3K/AKT and ERK Pathways

Gastric cancer is a common malignancy with a poor survival rate. Plantamajoside, a phenylethanoid glycoside from Plantago asiatica, has been shown to inhibit the progression of many different types of cancer; however, its effect on gastric cancer remains to be explored. To this end, the effect of plantamajoside on the proliferation, apoptosis, stemness, mobility, and invasion of gastric cancer was evaluated by cell survival assay, flow cytometry, colony formation, sphere formation, transwell, and Western blot assays. Also, the potential molecular mechanism was addressed by Western blot assays for the expression of various signal proteins. Plantamajoside reduced cell viability, enhanced apoptosis, reduced cell mobility, and increased invasion of both AGS and HS746T cells in a dose-dependent manner. Plantamajoside also decreased the diameter of the spheroid and the relative expression of octamer-binding transcription factor-4 and the cluster of differentiation 44 proteins in both AGS and HS746T cells. Furthermore, plantamajoside downregulated the relative protein levels of p-PI3K/PI3K, p-AKT/AKT, and p-ERK/ERK in both AGS and HS746T cells.