Yiqi Huayu Jiedu Decoction Inhibits the Invasion and Metastasis of Gastric Cancer Cells through TGF-β/Smad Pathway

Abstract

Background. Yiqi Huayu Jiedu Decoction (YHJD) can obviously improve the quality of life of those patients with gastric cancer and prolong their survival. Methods. In vitro experiments, we observe YHJD's effect on the cells' proliferation by MTT assay. Cell adhesion assay, wound-healing assay, and Transwell invasion assay serve to detect its influence on cells' adhesion, migration, and invasion, respectively. Inhibitor (10 μM/L of SB431542) and activator (10 ng/mL of TGF-β) of TGF-β/Smad pathway were used to estimate whether YHJD's impact on the biological behavior of gastric cancer cells was related to TGF-β/Smad pathway. In in vivo studies, YHJD was administered to the nude mice transplanted with gastric cancer to observe its effect on the tumor. Western blotting and immunohistochemical assay were used to test relevant cytokines of TGF-β/Smad pathway and epithelial-mesenchymal transition (EMT) in MGC-803 cells and the tumor bearing nude mice. Results. YHJD inhibited proliferation, adhesion, migration, and invasion of MGC-803 gastric cancer cells in vitro. In in vivo studies, YHJD reduced the volume of the transplanted tumors. It also enhanced the expression of E-cadherin and decreased the levels of N-cadherin, TGF-β, Snail, and Slug in both MGC-803 cells and the transplanted tumor by western blot assay. The immunohistochemical assay revealed that YHJD raised E-cadherin in the tumors of the mice; on the contrary, the expression of N-cadherin, Twist, vimentin, TGF-βR I, p-Smad2, p-Smad3, Snail, and Slug reduced. Conclusion. YHJD can effectively inhibit the invasion and metastasis of gastric cancer cells. The mechanism may be related to TGF-β/Smad pathway.