Open AccessPAR2 Inhibition Enhanced the Sensitivity of Colorectal Cancer Cells to 5-FU and Reduced EMT Signaling
Author(s) -
Qiuying Quan,
Fengyun Zhong,
Xinwei Wang,
Kai Chen,
Linxin Guo
Publication year - 2019
Publication title -
oncology research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.267
H-Index - 57
eISSN - 1555-3906
pISSN - 0965-0407
DOI - 10.3727/096504018x15442985680348
Subject(s) - epithelial–mesenchymal transition , in vivo , signal transduction , transfection , cancer research , viability assay , apoptosis , cell growth , transforming growth factor , cell culture , cell , receptor , biology , chemistry , downregulation and upregulation , microbiology and biotechnology , biochemistry , genetics , gene
The aim of this study was to investigate the underlying mechanisms that transforming growth factor-β (TGF-β)-mediated epithelial-to-mesenchymal transition (EMT) in tumor cells contributes to 5-FU resistance. A series of experiments involving cell viability and caspase activity analyses, siRNA transfection, RNA isolation, and quantitative-PCR (qPCR) assay, cell migration analysis, Western blotting analysis of total protein and membrane protein were performed in this study. Mouse xenograft model was used to determine the effect of the PAR2 inhibitor in vivo. In this study, we found that protease-activated receptor 2 (PAR2) induction in 5-FU therapy is correlated with TGF-β-mediated EMT and apoptosis resistance. PAR2 and TGF-β were both activated in response to 5-FU treatment in vivo and in vitro, and whereas TGF-β inhibition sensitized CRC cells to 5-FU and suppressed cell migration, PAR2 activation eliminated the effect of TGF-β inhibition. Conversely, siRNA-mediated PAR2 depletion or PAR2 inhibition with a specific inhibitor produced a similar phenotype as TGF-β signal inhibition: 5-FU sensitization and cell migration suppression. Moreover, the results of xenograft experiments indicated that the PAR2 inhibitor can enhance cell killing by 5-FU in vivo and suppress EMT signaling. Our results reveal that the TGF-β effects require the coordinating action of PAR2, suggesting that PAR2 inhibition could be a new therapeutic strategy to combat 5-FU resistance in CRC.