miR-544a induces epithelial-mesenchymal transition through the activation of WNT signaling pathway in gastric cancer.
The epithelial-mesenchymal transition (EMT) contributes to cancer progression, as well as the development of normal organs, wound healing and organ fibrosis. We established a cell-based reporter system for identifying EMT-inducing microRNAs (miRNAs) with a gastric cancer (GC) cell line, MKN1, transfected with a reporter construct containing a promoter sequence of VIM in the 5' upstream region of the TurboRFP reporter gene. Function-based screening using this reporter system was performed with a 328-miRNA library, and resulted in the identification miR-544a as an EMT-inducing miRNA. Although miR-544a is already known to be involved in the regulation of CDH1, the mechanism by which EMT occurs remains poorly understood. Herein, we demonstrated that overexpression of miR-544a induces VIM, SNAI1 and ZEB1 expression, and reduces CDH1 expression, resulting in an EMT phenotype. In addition, we found that CDH1 and AXIN2, which are related to the degradation and the translocation of β-catenin, are direct targets of miR-544a. Subsequently, the reduction of CDH1 and AXIN2 by miR-544a induced the nuclear import of β-catenin, suggesting that miR-544a may activate the WNT signaling pathway through the stabilization of β-catenin in nucleus. Our findings raise the possibility that inhibition of miR-544a may be a therapeutic target of metastatic GC.
Department of Molecular Cytogenetics, Medical Research Institute, Department of Surgical Oncology and.
Yoshimitsu
Y
Yanaka
Department of Molecular Cytogenetics, Medical Research Institute.
Tomoki
T
Muramatsu
Department of Surgical Oncology and.
Hiroyuki
H
Uetake
Department of Molecular Cytogenetics, Medical Research Institute, Bioresource Research Center, Graduate School, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8510, Japan, Department of Dental Pharmacology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama 700-8525, Japan and.
Ken-ichi
K
Kozaki
Department of Molecular Cytogenetics, Medical Research Institute, Bioresource Research Center, Graduate School, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8510, Japan, Hard Tissue Genome Research Center, Graduate School, Tokyo Medical and Dental University, Tokyo 113-8510, Japan johinaz.cgen@mri.tmd.ac.jp.
Johji
J
Inazawa
D021581:Active Transport, Cell Nucleus; D015703:Antigens, CD; D060466:Axin Protein / Q000235:genetics / Q000378:metabolism; D001483:Base Sequence; D001665:Binding Sites; D015820:Cadherins / Q000235:genetics / Q000378:metabolism; D045744:Cell Line, Tumor; D002465:Cell Movement; D058750:Epithelial-Mesenchymal Transition / Q000235:genetics*; D015972:Gene Expression Regulation, Neoplastic; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism; D006801:Humans; D035683:MicroRNAs / Q000502:physiology*; D055550:Protein Stability; D000071250:Snail Family Transcription Factors; D013274:Stomach Neoplasms / Q000235:genetics / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D060449:Wnt Signaling Pathway; D000071799:Zinc Finger E-box-Binding Homeobox 1; D051176:beta Catenin / Q000378:metabolism
C491761:AXIN2 protein, human; D015703:Antigens, CD; D060466:Axin Protein; C513384:CDH1 protein, human; C495270:CTNNB1 protein, human; D015820:Cadherins; D018398:Homeodomain Proteins; C582640:MIRN544 microRNA, human; D035683:MicroRNAs; C000604407:SNAI1 protein, human; D000071250:Snail Family Transcription Factors; D014157:Transcription Factors; C486307:ZEB1 protein, human; D000071799:Zinc Finger E-box-Binding Homeobox 1; D051176:beta Catenin