Research on the efficacy of Celastrus Orbiculatus in suppressing TGF-β1-induced epithelial-mesenchymal transition by inhibiting HSP27 and TNF-α-induced NF-κ B/Snail signaling pathway in human gastric adenocarcinoma

BMC Complement Altern Med. 2014 Nov 5;14:433. doi: 10.1186/1472-6882-14-433.

Abstract

Background: Celastrus orbiculatus has been used as a folk medicine in China for the treatment of many diseases. In the laboratory, the ethyl acetate extract of Celastrus orbiculatus (COE) displays a wide range of anticancer functions. However, the inhibition of the metastasis mechanism of COE in gastric cancer cells has not been investigated so far.

Methods: The present study was undertaken to determine if the anti-metastasis effect of COE was involved in inhibiting of epithelial-mesenchymal transition (EMT) of human gastric adenocarcinoma SGC-7901 cells. In vitro, a well-established experimental EMT model involving transforming growth factor β1 (TGF-β1) was applied. Viability, invasion and migration, protein and mRNA expression of tumor cells were analyzed by MTT assay, transwell assay, western blot and real-time PCR, respectively. The molecular targets of COE in SGC-7901 cells were investigated by two-dimensional gel electrophoresis (2-DE) and MALDI-TOF-TOF mass spectrometer. Overexpression of heat shock protein 27 (HSP27) was performed by transfected with the recombinant retroviral expression plasmid. In vivo, the anti-metastasis mechanisms of COE in the peritoneal gastric cancer xenograft model was explored and the effect was tested.

Results: The non-cytostatic concentrations of COE effectively inhibited TGF-β1 induced EMT process in SGC-7901 cells, which is characterized by prevented morphological changes, increased E-cadherin expression and decreased Vimentin, N-cadherin expression. Moreover, COE inhibited invasion and migration induced by TGF-β1. Using a comparative proteomics approach, four proteins were identified as differently expressed, with HSP27 protein being one of the most significantly down-regulated proteins induced by COE. Moreover, the activation of nuclear factor κB (NF-κB)/Snail signaling pathway induced by tumor necrosis factor-α (TNF-α) was also attenuated under the pretreatment of COE. Interestingly, overexpression of HSP27 significantly decreases the inhibitory effect of COE on EMT and the NF-κB/Snail pathway. Furthermore, COE significantly reduced the number of peritoneal metastatic nodules in the peritoneal gastric cancer xenograft model.

Conclusions: Taken together, these results suggest that COE inhibits the EMT by suppressing the expression of HSP27, correlating with inhibition of NF-κB/Snail signal pathways in SGC-7901 cells. Based on these results, COE may be considered a novel anti-cancer agent for the treatment of metastasis in gastric cancer.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenocarcinoma / drug therapy
  • Adenocarcinoma / genetics
  • Adenocarcinoma / metabolism*
  • Adenocarcinoma / physiopathology
  • Animals
  • Antineoplastic Agents, Phytogenic / administration & dosage*
  • Cadherins / metabolism
  • Celastrus / chemistry*
  • Cell Line, Tumor
  • Cell Movement / drug effects
  • Drugs, Chinese Herbal / administration & dosage*
  • Epithelial-Mesenchymal Transition / drug effects*
  • Gene Expression Regulation, Neoplastic / drug effects
  • HSP27 Heat-Shock Proteins / genetics
  • HSP27 Heat-Shock Proteins / metabolism
  • Humans
  • Male
  • Mice
  • Mice, Nude
  • NF-kappa B / genetics
  • NF-kappa B / metabolism
  • Signal Transduction / drug effects*
  • Snail Family Transcription Factors
  • Stomach Neoplasms / drug therapy
  • Stomach Neoplasms / genetics
  • Stomach Neoplasms / metabolism*
  • Stomach Neoplasms / physiopathology
  • Transcription Factors / genetics
  • Transcription Factors / metabolism
  • Transforming Growth Factor beta1 / genetics
  • Transforming Growth Factor beta1 / metabolism*
  • Tumor Necrosis Factor-alpha / genetics
  • Tumor Necrosis Factor-alpha / metabolism

Substances

  • Antineoplastic Agents, Phytogenic
  • Cadherins
  • Drugs, Chinese Herbal
  • HSP27 Heat-Shock Proteins
  • NF-kappa B
  • Snail Family Transcription Factors
  • Transcription Factors
  • Transforming Growth Factor beta1
  • Tumor Necrosis Factor-alpha