BACKGROUND/AIMS: Transforming growth factor beta (TGF-β) plays a major role in tumorigenesis. MicroRNA-181b (miRNA-181b) is a multifaceted miRNA that has been implicated in many cellular processes such as cell fate determination and cellular invasion. This study aimed to confirm the relationship of miRNA-181b and the TGF-β-Smad2/3/4 pathway with the induction of the epithelial-to-mesenchymal transition (EMT) in gastric cancer. METHODS: This study investigated the ability of TGF-β to induce migration by wound healing and transwell invasion assays in human gastric cancer cell lines. miRNA expression was altered using miRNA-181b mimic and inhibitor in the same system. Expression of miRNA-181b, the hypothetical target gene Timp3 and EMT-related markers were analyzed by real-time real-time quantitative RT-PCR. Immunoblotting was used to investigate the levels of phospho-Smad2 and Smad4. Dual-luciferase reporter assays were performed to confirm the direct binding of miRNA-181b to Timp3. RESULTS: miRNA-181b was significantly upregulated in response to TGF-β treatment in gastric cancer cell lines. Overexpression of miR-181b mimic induced an in vitro EMT-like change to a phenotype similar to that following TGF-β treatment alone and was reversed by miRNA-181b inhibitor. Inhibition of TGF-β-Smad2/3 signaling with SD-208 significantly attenuated the upregulation of miRNA-181b. Knockdown of Smad4 in gastric cancer cells strongly attenuated the upregulation of miRNA-181b. Moreover, miR-181b was found to directly target the 3' untranslated region (3'UTR) of Timp3 mRNA affecting TGF-β-induced EMT. CONCLUSIONS: Our results elucidate a novel mechanism through which the TGF-β pathway regulates the EMT of gastric cancer cells by increasing the levels of miRNA-181b to target Timp3 via the Smad2/3/4-dependent pathway. These findings provide insights into the cellular and environmental factors regulating EMT, which may guide future studies on therapeutic strategies targeting these cells.
BACKGROUND/AIMS: Transforming growth factor beta (TGF-β) plays a major role in tumorigenesis. MicroRNA-181b (miRNA-181b) is a multifaceted miRNA that has been implicated in many cellular processes such as cell fate determination and cellular invasion. This study aimed to confirm the relationship of miRNA-181b and the TGF-β-Smad2/3/4 pathway with the induction of the epithelial-to-mesenchymal transition (EMT) in gastric cancer. METHODS: This study investigated the ability of TGF-β to induce migration by wound healing and transwell invasion assays in humangastric cancer cell lines. miRNA expression was altered using miRNA-181b mimic and inhibitor in the same system. Expression of miRNA-181b, the hypothetical target gene Timp3 and EMT-related markers were analyzed by real-time real-time quantitative RT-PCR. Immunoblotting was used to investigate the levels of phospho-Smad2 and Smad4. Dual-luciferase reporter assays were performed to confirm the direct binding of miRNA-181b to Timp3. RESULTS: miRNA-181b was significantly upregulated in response to TGF-β treatment in gastric cancer cell lines. Overexpression of miR-181b mimic induced an in vitro EMT-like change to a phenotype similar to that following TGF-β treatment alone and was reversed by miRNA-181b inhibitor. Inhibition of TGF-β-Smad2/3 signaling with SD-208 significantly attenuated the upregulation of miRNA-181b. Knockdown of Smad4 in gastric cancer cells strongly attenuated the upregulation of miRNA-181b. Moreover, miR-181b was found to directly target the 3' untranslated region (3'UTR) of Timp3 mRNA affecting TGF-β-induced EMT. CONCLUSIONS: Our results elucidate a novel mechanism through which the TGF-β pathway regulates the EMT of gastric cancer cells by increasing the levels of miRNA-181b to target Timp3 via the Smad2/3/4-dependent pathway. These findings provide insights into the cellular and environmental factors regulating EMT, which may guide future studies on therapeutic strategies targeting these cells.
Authors: Jack M Heath; Joan Fernandez Esmerats; Lucky Khambouneheuang; Sandeep Kumar; Rachel Simmons; Hanjoong Jo Journal: Cardiovasc Eng Technol Date: 2017-02-24 Impact factor: 2.495
Authors: Jiaxin Liang; Mengqian Chen; Daniel Hughes; Alexander A Chumanevich; Serena Altilia; Vimala Kaza; Chang-Uk Lim; Hippokratis Kiaris; Karthikeyan Mythreye; Maria Marjorette Pena; Eugenia V Broude; Igor B Roninson Journal: Cancer Res Date: 2018-09-05 Impact factor: 12.701
Authors: Lujun Chen; Jun Feng; Bin Xu; You Zhou; Xiao Zheng; Changping Wu; Jingting Jiang Journal: Cancer Cell Int Date: 2018-09-04 Impact factor: 5.722