Celastrus Orbiculatus Extract Suppresses Migration and Invasion of Gastric Cancer by Inhibiting Prohibitin and c-Raf/ERK Signaling Pathway

Background and Objective: The traditional Chinese medicine herb Celastrus Orbiculatus is a folk medicinal plant that has been used in various diseases. The ethyl acetate extract of Celastrus orbiculatus (COE) was reported to show significant anti-tumor effects. Prohibitin (PHB), an evolutionarily-conserved protein has been found to be over-expressed in Gastric Cancer (GC) and be closely related with tumor malignancy. In this study the effects of COE and small interfering RNA (siRNA)-mediated silencing of PHB gene expression on the migration and invasion of GC was investigated. Materials and Methods: The effects of COE on the expression of PHB in MGC-803 GC cells were evaluated by Western Blots. Small interfering RNA (siRNA)sequences targeting PHB were transfected into the MGC-803 cell line.The effect of COE on PHB silenced GC cell viability was examined using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The effects of COE and siRNA-mediated silencing of PHB gene expression on invasion and migration of GC and protein expression of tumor cells were analyzed by wound-healing assay, trans well assay and Western Blots, respectively. Results: It was found that COE reduced PHB expression in MGC-803 cells. In addition, invasion and migration of GC was significantly decreased upon PHB silencing. Gene silencing of PHB increased E-cadherin expression, decreased N-cadherin,Vimentin expression and inhibited c-Raf/ERKsignaling pathway. Moreover, COE effectively inhibited GC invasion and migration, EMT and c-Raf/ERK signaling pathway of PHB silenced MGC-803 cells in a dose-dependent manner. Conclusion: The COE inhibits migration and invasion probably via suppressing PHB expression,which correlates with c-Raf/ERK signal pathway inhibition in MGC-803 cells.