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ABSTRACT: Background
Tumor hypoxia-induced epithelial-mesenchymal transition (EMT) is critical in promoting cancer metastasis. We recently discovered a novel microtubule inhibitor, MPT0B098, that employs a novel antitumor mechanism. It destabilizes hypoxia-inducible factor (HIF)-1? mRNA by blocking the function of human antigen R. Thus, we proposed that MPT0B098 modulates hypoxia-induced EMT.Methods
In vitro IC50 values were determined through the methylene blue dye assay. To investigate molecular events, reverse transcriptase-polymerase chain reaction, Western blotting, immunofluorescence staining, and wound healing assay were employed.Results
MPT0B098 significantly inhibited HIF-1? expression, epithelial-to-mesenchymal morphology changes, and migratory ability in the human head and neck squamous cell carcinoma cell line OEC-M1. Furthermore, after MPT0B098 treatment, the expression of two mesenchymal markers, vimentin and N-cadherin, was downregulated under hypoxic conditions. Moreover, MPT0B098 suppressed hypoxia-induced EMT in part by inhibiting EMT-activating transcription factors, Twist and SNAI2/Slug. In addition, the inhibition of hypoxia-induced F-actin rearrangement and focal adhesion kinase phosphorylation may have contributed to suppression of EMT by MPT0B098in OEC-M1 cells. MPT0B098 significantly inhibited transforming growth factor(TGF)-?-induced phosphorylation of receptor-associated Smad2/3 by downregulating TGF-? mRNA and protein expression.Conclusions
Taken together, this study provides a novel insight into the role of MPT0B098 in inhibiting hypoxia-induced EMT, suggesting its potential use for treating head and neck cancers.
SUBMITTER: Tsai IT
PROVIDER: S-EPMC5875002 | biostudies-literature | 2018 Mar
REPOSITORIES: biostudies-literature
Tsai I-Ting IT Kuo Ching-Chuan CC Liou Jing-Ping JP Chang Jang-Yang JY
Journal of biomedical science 20180328 1
<h4>Background</h4>Tumor hypoxia-induced epithelial-mesenchymal transition (EMT) is critical in promoting cancer metastasis. We recently discovered a novel microtubule inhibitor, MPT0B098, that employs a novel antitumor mechanism. It destabilizes hypoxia-inducible factor (HIF)-1α mRNA by blocking the function of human antigen R. Thus, we proposed that MPT0B098 modulates hypoxia-induced EMT.<h4>Methods</h4>In vitro IC<sub>50</sub> values were determined through the methylene blue dye assay. To in ...[more]