Celastrus orbiculatus Extract Inhibits the Epithelial-Mesenchymal Transition Process by Transforming Growth Factor-β Signaling Pathway in Gastric Cancer

Background: Gastric cancer is the fifth most common tumor and has the third-highest mortality rate among various malignant tumors, and the survival rate of patients is low. Celastrus orbiculatus extract (COE) has been shown to inhibit the activity of a variety of tumors. In this study, we examined the inhibition of the epithelial-mesenchymal transition (EMT) process in gastric cancer cells by COE through the transforming growth factor-β (TGF-β) signaling pathway. Methods: COE was first diluted to various concentrations and then used to treat SGC-7901, BGC-823, MGC-803, and AGS cells. Cell proliferation was assessed by an MTT (thiazole blue) assay. Transwell assays were used to assess cell invasion and migration. The high-content imaging technology was used to further observe the effects of the drug on cell invasion and migration. Western blotting was used to assess the effects of the drug on the expression of EMT and Smad2/3 signaling pathway-related proteins. Results: We found that COE inhibited the migration and invasion of AGS gastric cancer cells in a dose-dependent manner. Consequently, COE decreased the expression of EMT-related proteins and proteins related to the Smad2/3 signaling pathway in gastric cancer cells, inhibiting the migration and invasion of gastric cancer cells, and this effect occurred through the TGF-β signaling pathway. Conclusion: We investigated that COE could inhibit the proliferation of gastric cancer cells and inhibit invasion and metastasis by inhibiting the EMT process at the molecular level and its effect on the TGF-β signaling pathway.