title: MiR-424-5p participates in esophageal squamous cell carcinoma invasion and metastasis via SMAD7 pathway mediated EMT.
abstract: BACKGROUND
  ESCC is a life-threatening disease due to invasion and metastasis in the early stage. Great efforts had been made to detect the molecular mechanisms which led to the invasion and metastasis in ESCC. Recent evidence had suggested that deregulation of miR-424-5p took an important role in cancers. However, its role and functional mechanism in ESCC had seldom been elucidated.
  
  
  METHODS
  The expression levels of miR-424-5p were detected in ESCC tissues and cell lines by real-time PCR methods. Then, the invasion, metastasis and proliferation ability of ESCC cell lines transfected with miR-424-5p mimics were analyzed separately by transwell invasion assay, wound healing assay and cell proliferation assay. Finally, the target gene of miR-424-5p was studied and verified by luciferase activity assay. And the role of miR-424-5p in EMT was also investigated by real-time PCR and western blot assay.
  
  
  RESULTS
  We showed that the expression levels of miR-424-5p were decreased both in ESCC tissues and cell lines. Furthermore, the expression levels of miR-424-5p were negatively linked to lymph node metastasis in ESCC tissues. Restoration of miR-424-5p in EC-1 cells by using miR-424-5p mimics could decrease the invasion, metastasis and proliferation of EC-1 cells, indicating its role in inhibition on the invasion and metastasis ability of ESCC cells and tissues. In addition, we demonstrated that SMAD7 was a specific target gene for miR-424-5p by luciferase activity assay and miR-424-5p could not only negatively regulate SMAD7 expression but also participate in EMT via SMAD7, because overexpression of SMAD7 could partly enhance the miR-424-5p anti-EMT function.
  
  
  CONCLUSIONS
  Our results described that miR-424-5p -SMAD7 pathway contributed to ESCC invasion and metastasis and up-regulation of miR-424-5p perhaps provided a strategy for preventing tumor invasion, metastasis.
authors.affiliation: Department of Oncology, the First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052, People's Republic of China.
authors.forename: Feng
authors.initials: F
authors.lastname: Wang
authors.affiliation: Department of Oncology, the First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052, People's Republic of China.
authors.forename: Jun
authors.initials: J
authors.lastname: Wang
authors.affiliation: Department of Microbiology and Immunology, College of Basic Medical Sciences, Zhengzhou University, Zhengzhou, 450052, People's Republic of China.
authors.forename: Xuan
authors.initials: X
authors.lastname: Yang
authors.affiliation: Department of Oncology, the First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052, People's Republic of China.
authors.forename: Danjie
authors.initials: D
authors.lastname: Chen
authors.affiliation: Department of Oncology, the First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052, People's Republic of China. wlx2246@126.com.
authors.forename: Liuxing
authors.initials: L
authors.lastname: Wang
mesh_terms: D020413:3' Untranslated Regions; D001665:Binding Sites; D002294:Carcinoma, Squamous Cell / Q000235:genetics / Q000378:metabolism* / Q000556:secondary; D045744:Cell Line, Tumor; D002465:Cell Movement; D058750:Epithelial-Mesenchymal Transition; D004938:Esophageal Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D000077277:Esophageal Squamous Cell Carcinoma; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008207:Lymphatic Metastasis; D008297:Male; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism*; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D015398:Signal Transduction; D051906:Smad7 Protein / Q000235:genetics / Q000378:metabolism*; D014162:Transfection
chemical_list: D020413:3' Untranslated Regions; C554214:MIRN424 microrna, human; D035683:MicroRNAs; C497806:SMAD7 protein, human; D051906:Smad7 Protein
keywords: Epithelial-mesenchymal transition; Esophageal squamous cell carcinoma; SMAD7; miR-424-5p