Betulonic Acid, as One of the Active Components of the Celastrus orbiculatus Extract, Inhibits the Invasion and Metastasis of Gastric Cancer Cells by Mediating Cytoskeleton Rearrangement In Vitro.

Zewen Chu,Xinyi Feng,Yuanyuan Luo,Miao Zhu,Haibo Wang,Yanqing Liu,Tengyang Ni

doi:10.3390/molecules27031025

Abstract

Gastric cancer is a type of malignant tumor that seriously threatens human life and health. Invasion and metastasis present difficulties in the treatment of gastric cancer, and the remodeling of the tumor cytoskeleton plays an important role in mediating the ability of tumor cells to achieve invasion and metastasis. Previous experimental results suggest that Celastrus orbiculatus extract can regulate cytoskeletal remodeling in gastric cancer, but the active component has not been determined. Betulonic acid, as an effective component of COE, inhibits the invasion and metastasis of gastric cancer cells by regulating cytoskeletal remodeling in vitro; its specific mechanisms have been studied here. After betulonic acid was dissolved, it was diluted to various working concentrations in RPMI-1640 medium and added to AGS, HGC-27 and GES-1 cell lines. Cell viability was assessed by CCK-8 and colony formation assays. Cytoskeleton staining was used to detect changes in cytoskeleton morphology. Functional assays including wound healing assays and transwell assays were used to detect the invasion and migration of cells. The effect of betulonic acid on cell invasion and migration was clearly and precisely observed by high-content imaging technology. Western blotting was used to detect the regulation of matrix metalloproteinase-related proteins and epithelial–mesenchymal transformation-related proteins. We found that betulonic acid inhibited the migration and invasion of gastric cancer cells. Therefore, betulonic acid inhibits the invasion and metastasis of gastric cancer cells by mediating cytoskeletal remodeling and regulating epithelial mesenchymal transformation.

Highlights

The CCK-8 assay showed that AGS and HGC-27 cells treated with betulonic acid showed concentration- and time-dependent inhibition compared with the control group (Figure 1B,C)
In order to exclude the toxic effects of betulonic acid on the cells, the AGS and HGC-27 cells were treated with low concentrations of betulonic acid (20, 40 and 80 μM) for 24 h in the following experiments to investigate the inhibitory effects of betulonic acid on AGS and HGC-27 cell viability
In order to study the inhibition of betulonic acid on the cytoskeletal remodeling of gastric cancer cells, we conducted cytoskeletal staining experiments; the results showed that the cytoskeletal staining was deeper in the control group, and more pseudopodia were formed around the cells

Summary

Introduction

The invasion and metastasis of GC cells require a series of changes in biological characteristics, including epithelial–mesenchymal transformation (EMT), pseudopodia formation, and the secretion of invasion and metastasis-related factors and enzymes. The remodeling of the tumor cytoskeleton plays an important role in mediating the invasion and metastasis ability of tumor cells [2,3]. Tumor cytoskeleton remodeling refers to the re-disassembly and assembly of fibrous and spherical microfilaments in the cytoskeleton during the movement of tumor cells, forming a new cytoskeleton structure and changing its morphology (including the formation of pseudopodia), making tumor cells able to migrate [4,5]. Tumor cells transform from epithelial cell morphology to mesenchymal cell morphology by remodeling their cytoskeleton, and at the same time, remodeling their skeleton at the cell edge, forming polar lamellar and filamentous pseudopodia structures. The part of the pseudopodia in contact with the matrix is enriched with relevant adhesion molecules such as FAK, etc

Results

Discussion

Conclusion