Publication: Blocking ERK1/2 signaling impairs TGF-β1 tumor promoting function but enhances its tumor suppressing role in intrahepatic cholangiocarcinoma cells
Issued Date
2017
Resource Type
Language
eng
Rights
Mahidol University
Rights Holder(s)
BioMed Central
Bibliographic Citation
Cancer Cell International. Vol. 17(2017),85
Suggested Citation
Phaijit Sritananuwat, Natthaporn Sueangoen, Parichut Thummarati, Kittiya Islam, Tuangporn Suthiphongchai Blocking ERK1/2 signaling impairs TGF-β1 tumor promoting function but enhances its tumor suppressing role in intrahepatic cholangiocarcinoma cells. Cancer Cell International. Vol. 17(2017),85. doi:10.1186/s12935-017-0454-2 Retrieved from: https://repository.li.mahidol.ac.th/handle/20.500.14594/17223
Research Projects
Organizational Units
Authors
Journal Issue
Thesis
Title
Blocking ERK1/2 signaling impairs TGF-β1 tumor promoting function but enhances its tumor suppressing role in intrahepatic cholangiocarcinoma cells
Abstract
Background: Transforming growth factor-β (TGF-β) plays a paradoxical role in cancer: it suppresses proliferation at
early stages but promotes metastasis at late stages. This cytokine is upregulated in cholangiocarcinoma and is implicated
in cholangiocarcinoma invasion and metastasis. Here we investigated the roles of non-Smad pathway (ERK1/2)
and Smad in TGF-β tumor promoting and suppressing activities in intrahepatic cholangiocarcinoma (ICC) cells.
Methods: TGF-β1 efects on proliferation, invasion and migration of ICC cells, KKU-M213 and/or HuCCA-1, were
investigated using MTT, colony formation, in vitro Transwell and wound healing assays. Levels of mRNAs and proteins/
phospho-proteins were measured by quantitative (q)RT-PCR and Western blotting respectively. E-cadherin localization
was examined by immunofuorescence and secreted MMP-9 activity was assayed by gelatin zymography. The role of
ERK1/2 signaling was evaluated by treating cells with TGF-β1 in combination with MEK1/2 inhibitor U0126, and that of
Smad2/3 and Slug using siSmad2/3- and siSlug-transfected cells.
Results: h-TGF-β1 enhanced KKU-M213 cell invasion and migration and induced epithelial-mesenchymal transition
as shown by an increase in vimentin, Slug and secreted MMP-9 levels and by a change in E-cadherin localization
from membrane to cytosol, while retaining the cytokine’s ability to attenuate cell proliferation. h-TGF-β1 stimulated
Smad2/3 and ERK1/2 phosphorylation, and the MEK1/2 inhibitor U0126 attenuated TGF-β1-induced KKU-M213 cell
invasion and MMP-9 production but moderately enhanced the cytokine growth inhibitory activity. The latter efect
was more noticeable in HuCCA-1 cells, which resisted TGF-β-anti-proliferative activity. Smad2/3 knock-down suppressed
TGF-β1 ability to induce ERK1/2 phosphorylation, Slug expression and cell invasion, whereas Slug knockdown
suppressed cell invasion and vimentin expression but marginally afected ERK1/2 activation and MMP-9 secretion.
These results indicate that TGF-β1 activated ERK1/2 through Smad2/3 but not Slug pathway, and that ERK1/2
enhanced TGF-β1 tumor promoting but repressed its tumor suppressing functions.
Conclusions: Inhibiting ERK1/2 activation attenuates TGF-β1 tumor promoting efect (invasion) but retains its tumor
suppressing role, thereby highlighting the importance of ERK1/2 in resolving the TGF-β paradox switch.