title: MiR-206 functions as a tumor suppressor and directly targets K-Ras in human oral squamous cell carcinoma.
abstract: OBJECTIVE
  MicroRNA-206 (miR-206) has been proven to be downregulated in many human malignancies and is correlated with tumor progression. However, the roles of miR-206 and its related molecular mechanisms in oral squamous cell carcinoma (OSCC) are still unclear. Thus, the aim of this study was to explore the effects of miR-206 in OSCC tumorigenesis and development.
  
  
  METHODS
  Quantitative real-time polymerase chain reaction was used to detect miR-206 expression in OSCC cell lines and primary tumor tissues. The association of miR-206 expression with clinicopathological factors and prognosis was also analyzed. In addition, the effects of miR-206 on the biological behavior of OSCC cells were investigated. Lastly, the potential regulatory function of miR-206 on K-Ras expression was confirmed.
  
  
  RESULTS
  MiR-206 expression was significantly downregulated in OSCC tissue samples and cell lines (both P<0.001). Decreased miR-206 expression was significantly associated with advanced tumor node metastasis (TNM) stage, advanced T classifications (ie, size and/or extent of the primary tumor), positive N classification (ie, spread to regional lymph nodes), and shorter overall survival. In addition, upregulation of miR-206 in Tca8113 cells was able to reduce cell proliferation, invasion, and migration and promote cell apoptosis in vitro. Further, K-Ras was confirmed as a direct target of miR-206 by using luciferase reporter assay.
  
  
  CONCLUSIONS
  These findings indicate that miR-206 may act as a tumor suppressor in OSCC and could serve as a novel therapeutic agent for miR-based therapy.
authors.affiliation: Department of Orthodontics, School and Hospital of Stomatology, Wenzhou Medical University, Wenzhou, People's Republic of China.
authors.forename: Feiou
authors.initials: F
authors.lastname: Lin
authors.affiliation: Department of Pedodontics, School and Hospital of Stomatology, Wenzhou Medical University, Wenzhou, People's Republic of China.
authors.forename: Linjie
authors.initials: L
authors.lastname: Yao
authors.affiliation: Department of Oral and Maxillofacial Surgery, School and Hospital of Stomatology, Wenzhou Medical University, Wenzhou, People's Republic of China.
authors.forename: Jin
authors.initials: J
authors.lastname: Xiao
authors.affiliation: Department of Oral and Maxillofacial Surgery, School and Hospital of Stomatology, Wenzhou Medical University, Wenzhou, People's Republic of China.
authors.forename: DengFeng
authors.initials: D
authors.lastname: Liu
authors.affiliation: Department of Orthodontics, School and Hospital of Stomatology, Wenzhou Medical University, Wenzhou, People's Republic of China.
authors.forename: Zhenyu
authors.initials: Z
authors.lastname: Ni
keywords: apoptosis; invasion; miR-206; oral squamous cell carcinoma; prognosis; proliferation