title: Downregulation of miR-200a induces EMT phenotypes and CSC-like signatures through targeting the β-catenin pathway in hepatic oval cells.
abstract: Hepatocellular carcinoma (HCC) can be derived from malignant transformed adult hepatic progenitor cells. However, the regulatory factors and molecular mechanisms underlying the process are not well defined. Our previous microRNA (miRNA) microarray analysis revealed a significant decrease of miR-200a level in F344 rat HCC side population (SP) fraction cells versus their normal counterparts. In the present study, we further investigated the effect of miR-200a on hepatic oval cell (HOC) phenotypes. We first confirmed downregulated miR-200a levels in rat hepatoma cells compared with WB-F344 cells. Next, by lentivirus-mediated loss-of-function studies, we showed that stable knockdown of miR-200a confers a mesenchymal phenotype to WB-F344 cells, including an elongated cell morphology, enhanced cell migration ability and expression of epithelial mesenchymal transition (EMT)-representative markers. Concomitantly, several cancer stem cell (CSC)-like traits appeared in these cells, which exhibit enhanced spheroid-forming capacity, express putative hepatic CSC markers and display superior resistance to chemotherapeutic drugs in vitro. Furthermore, bioinformatics analysis, luciferase assays and western blot analysis identified β-catenin (CTNNB1) as a direct and functional target of miR-200a. Knockdown of miR-200a partially activated Wnt/β-catenin signaling, and silencing of β-catenin functionally attenuated anti-miR-200a effects in vitro in WB-F344 cells. At length, in vivo xenograft assay demonstrated the acquisition of tumorigenicity of WB-F344 cells after miR-200a siliencing. Collectively, our findings indicate that miR-200a may function as an important regulatory factor in neoplastic transition of HOCs by targeting the β-catenin pathway.
authors.affiliation: Department of Hepatobiliary Surgery, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi, People's Republic of China.
authors.forename: Jie
authors.initials: J
authors.lastname: Liu
authors.forename: Bai
authors.initials: B
authors.lastname: Ruan
authors.forename: Nan
authors.initials: N
authors.lastname: You
authors.forename: Qike
authors.initials: Q
authors.lastname: Huang
authors.forename: Weihui
authors.initials: W
authors.lastname: Liu
authors.forename: Zheng
authors.initials: Z
authors.lastname: Dang
authors.forename: Weihua
authors.initials: W
authors.lastname: Xu
authors.forename: Ti
authors.initials: T
authors.lastname: Zhou
authors.forename: Ru
authors.initials: R
authors.lastname: Ji
authors.forename: Yang
authors.initials: Y
authors.lastname: Cao
authors.forename: Xia
authors.initials: X
authors.lastname: Li
authors.forename: Desheng
authors.initials: D
authors.lastname: Wang
authors.forename: Kaishan
authors.initials: K
authors.lastname: Tao
authors.forename: Kefeng
authors.initials: K
authors.lastname: Dou
mesh_terms: D000818:Animals; D017209:Apoptosis; D006528:Carcinoma, Hepatocellular / Q000235:genetics* / Q000473:pathology; D002460:Cell Line; D045744:Cell Line, Tumor; D002465:Cell Movement; D049109:Cell Proliferation; D058750:Epithelial-Mesenchymal Transition / Q000235:genetics* / Q000502:physiology; D022781:Hepatocytes / Q000378:metabolism / Q000473:pathology; D008113:Liver Neoplasms / Q000235:genetics* / Q000473:pathology; D008297:Male; D051379:Mice; D008819:Mice, Nude; D035683:MicroRNAs / Q000235:genetics / Q000502:physiology*; D051381:Rats; D051176:beta Catenin / Q000235:genetics / Q000378:metabolism*
chemical_list: D035683:MicroRNAs; D051176:beta Catenin