ESC reverses epithelial mesenchymal transition induced by transforming growth factor-β via inhibition of Smad signal pathway in HepG2 liver cancer cells.

Xiao-Ni Liu,De-Xi Chen,Xiao-Xin Zhu,Shuang Wang,Ya-Jie Wang,Qing Yang

doi:10.1186/s12935-015-0265-2

Abstract

BackgroundEpithelial mesenchymal transition (EMT) mediated by TGF-β pays an important role in malignant tumor acquired abilities of migration and invasion. Our previous study showed that the extract of Stellera chamaejasme L. (ESC) was against proliferation of a variety of tumor cells, but there were no studies in the effects of ESC on EMT in tumor cells. In this study, TGF-β was adopted to induce EMT in HepG2 cells and the influence of ESC on EMT was observed.MethodsMTT assay was used to observe the cell viability. Wound healing assay and transwell assay were used to observe the migration and invasion activities. Western blot and immunofluorescence methods were used to observe the expression of proteins.ResultsWe found that HepG2 cells induced by TGF-β showed mesenchymal morphology, down-regulation of epithelial marker E-cadherin and up-regulation of mesenchymal marker Vimentin, indicating that TGF-β could mediate epithelial mesenchymal induction in HepG2 cells. ESC could reverse the mesenchymal morphology and regulate expressions of marker proteins in HepG2 induced by TGF-β and significantly inhibit TGF-β induced HepG2 cell migration and invasion. We further found that ESC could also significantly depress Smad2 phosphorylation and nuclear translocation, and ESC had coordination with SB432542, a specific inhibitor of TβRI kinases.ConclusionsThese results suggested that the ESC could reverse epithelial mesenchymal transition induced by TGF-β via inhibition Smad2 signaling pathway.

Highlights

Epithelial mesenchymal transition (EMT) mediated by TGF-β pays an important role in malignant tumor acquired abilities of migration and invasion
TGF-β decreased the E-cadherin and induced the Vimentin expression in HepG2 cells (Fig. 1b, c). These results suggested that TGF-β could induce EMT in HepG2 cells
HepG2 cells were pretreated with 5 μg/mL extract of Stellera chamaejasme L. (ESC) for different hours (1–4 h) prior to 5 ng/mL TGF-β stimulation, the time-dependent effects of ESC were showed (Fig. 4c). These results suggested that ESC reversed marker proteins changes of EMT induced by TGF-β in HepG2 cells

Summary

Introduction

Epithelial mesenchymal transition (EMT) mediated by TGF-β pays an important role in malignant tumor acquired abilities of migration and invasion. It is found that epithelial mesenchymal transition (EMT) is an important biological process for malignant tumor cells to obtain migratory and invasive. Smad and Smad associate with the shared partner Smad and the complexes accumulate in the nucleus where they regulate the expression of TGF-β target genes through cooperative interactions with transcriptional partners, which is process of the classical Smad-dependent signaling pathway that TGF-β induced [5, 6]. Many studies showed that a variety of Stellera chamaejasme L. extracts or monomers had anti-tumor activities and could induce apoptosis of tumor cells [7,8,9,10]. We further observed the effects of ESC on TGF-β-mediated EMT and classical Smad-dependent signaling pathway in HepG2 liver cancer cells

Methods

Results

Conclusion