title: MicroRNA-26b regulates cancer proliferation migration and cell cycle transition by suppressing TRAF5 in esophageal squamous cell carcinoma.
abstract: BACKGROUND
  MicroRNAs have been identified to play important role in the development of human esophageal squamous carcinoma (ESCC). In this study, we examined the regulatory effects of microRNA-26b (miR-26b) on ESCC proliferation, cell-cycle transition and migration.
  
  
  METHODS
  Expressions of miR-26a and miR-2bb were analyzed in 8 ESCC cell lines, and 27 human ESCC tissues and paired adjacent non-tumor tissues. MiR-26a and miR-26b were either upregulated or downregulated in ESCC cell lines TE-1 and Kyse140 cells. Their effects on ESCC in vitro growth, cell-cycle transition and migration were analyzed by proliferation assay, cell-cycle assay and invasion assay, respectively. The association of miR-26b and its downstream target gene, tumor necrosis factor receptor-associated factor 5 (TRAF5), was analyzed by luciferase reporter assay and qRT-PCR. TRAF5 was downregulated in TE-1 and Kyse140 cells to analyze its direct effect on miR-26b downregulation induced ESCC inhibition.
  
  
  RESULTS
  MiR-26b expression was aberrantly upregulated in ESCC cell lines and human ESCC tissues, whereas miR-26a expression was unchanged. In TE-1 and Kyse140 cells, miR-26b downregulation had tumor-suppressive effect, whereas miR-26b downregulation or miR-26a upregulation/downregulation had no significant effect, on ESCC proliferation, cell-cycle transition and migration. TRAF5 is confirmed to be the downstream target of miR-26b in ESCC. SiRNA-mediated TRAF5 downregulation inversely regulated the inhibition of miR-26b downregulation on ESCC proliferation, cell-cycle transition and migration.
  
  
  CONCLUSIONS
  our study demonstrates that miR-26b downregulation, through the inverse regulation on TRAF5, had tumor-suppressive effect on human ESCC.
authors.affiliation: Department of Thoracic Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology 1277 Jie Fang Avenue, Wuhan 430022, China.
authors.forename: Zhuo
authors.initials: Z
authors.lastname: Chen
authors.affiliation: Department of Thoracic Surgery, The Central Hospital of Wuhan, Tongji Medical College of Huazhong University of Science and Technology Wuhan 430030, China.
authors.forename: Liang
authors.initials: L
authors.lastname: Zhao
authors.affiliation: Department of Thoracic Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology 1277 Jie Fang Avenue, Wuhan 430022, China.
authors.forename: Feng
authors.initials: F
authors.lastname: Zhao
authors.affiliation: Department of Thoracic Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology 1277 Jie Fang Avenue, Wuhan 430022, China.
authors.forename: Guanghai
authors.initials: G
authors.lastname: Yang
authors.affiliation: Department of Thoracic Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology 1277 Jie Fang Avenue, Wuhan 430022, China.
authors.forename: Jianjun
authors.initials: J
authors.lastname: Wang
keywords: Esophageal squamous carcinoma; TRAF5; miR-26a; miR-26b; migration; proliferation