title: JunB promotes cell invasion, migration and distant metastasis of head and neck squamous cell carcinoma.
abstract: BACKGROUND
  While treatment failure in cases of head and neck squamous cell carcinoma (HNSCC) frequently takes the form of locoregional recurrences and distant metastasis, our understanding of the mechanisms of metastasis in HNSCC is limited. We initially performed the upstream and key nodes analysis together with whole gene microarray analysis characterized by distant metastatic potential in vivo with HNSCC cell lines and identified JunB, a member of the activator protein-1 (AP-1) family, as a key molecule in the regulation of the pathways related to distant metastasis in HNSCC. We have therefore tested the hypothesis that JunB plays a crucial role in distant metastasis in HNSCC.
  
  
  METHODS
  To study the role of JunB on metastatic potential of HNSCC, small interfering RNA (siRNA)-mediated knockdown and clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (cas9) system (CRISPR/Cas9)-mediated knockout of JunB in HNSCC cells were established and the abilities of cell invasion and migration in vitro were examined. The efficacy of knockout of JunB was also examined using an experimental lung metastatic mouse model of HNSCC. In addition, to study if the role of JunB in HNSCC cell migration and invasiveness is related to epithelial-to-mesenchymal transition (EMT), cell morphology and expression of mesenchymal or epithelial marker on siRNA mediated JunB knockdown in HNSCC cells were examined with or without TGF-β stimulation.
  
  
  RESULTS
  siRNA knockdown and sgRNA knockout of JunB in metastatic HNSCC cells significantly suppressed both cell invasion and migration in vitro. In addition, the knockout of JunB in metastatic HNSCC cells significantly repressed the incidence of lung metastases and prolonged the survival in vivo. However, we did not observe any change in cell morphology with the down-regulation of mesenchymal markers and up-regulation of epithelial markers in response to siRNA-mediated JunB knockdown in HNSCC cells.
  
  
  CONCLUSIONS
  These results suggested that JunB could play an important role in promoting cell invasion, migration and distant metastasis in HNSCC via pathways other than EMT and that the down-regulation of JunB may become an effective strategy for patients with invasive HNSCC.
authors.affiliation: Department of Biology and Function in Head and Neck, Yokohama City University Graduate School of Medicine, Yokohama, Japan. hhyaku@yokohama-cu.ac.jp.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Hyakusoku
authors.affiliation: Department of Biology and Function in Head and Neck, Yokohama City University Graduate School of Medicine, Yokohama, Japan. dsano@yokohama-cu.ac.jp.|Department of Otorhinolaryngology - Head and Neck Surgery, Yokohama City University, School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama, 236-0004, Japan. dsano@yokohama-cu.ac.jp.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Sano
authors.affiliation: Department of Biology and Function in Head and Neck, Yokohama City University Graduate School of Medicine, Yokohama, Japan. htk98@yokohama-cu.ac.jp.|Department of Otorhinolaryngology - Head and Neck Surgery, Yokohama City University, School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama, 236-0004, Japan. htk98@yokohama-cu.ac.jp.
authors.forename: Hideaki
authors.initials: H
authors.lastname: Takahashi
authors.affiliation: Department of Biology and Function in Head and Neck, Yokohama City University Graduate School of Medicine, Yokohama, Japan. t146065d@yokohama-cu.ac.jp.
authors.forename: Takashi
authors.initials: T
authors.lastname: Hatano
authors.affiliation: Department of Biology and Function in Head and Neck, Yokohama City University Graduate School of Medicine, Yokohama, Japan. t146012g@yokohama-cu.ac.jp.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Isono
authors.affiliation: Department of Biology and Function in Head and Neck, Yokohama City University Graduate School of Medicine, Yokohama, Japan. t146047g@yokohama-cu.ac.jp.
authors.forename: Shoko
authors.initials: S
authors.lastname: Shimada
authors.affiliation: Department of Urology, Yokohama City University Graduate School of Medicine, Yokohama, Japan. t116008e@yokohama-cu.ac.jp.
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Ito
authors.affiliation: Department of Head and Neck Surgery, The University of Texas M. D. Anderson Cancer Center, Houston, Texas, USA. jmyers@mdanderson.org.
authors.forename: Jeffrey N
authors.initials: JN
authors.lastname: Myers
authors.affiliation: Department of Biology and Function in Head and Neck, Yokohama City University Graduate School of Medicine, Yokohama, Japan. noridate@yokohama-cu.ac.jp.|Department of Otorhinolaryngology - Head and Neck Surgery, Yokohama City University, School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama, 236-0004, Japan. noridate@yokohama-cu.ac.jp.
authors.forename: Nobuhiko
authors.initials: N
authors.lastname: Oridate
mesh_terms: D000818:Animals; D002294:Carcinoma, Squamous Cell / Q000378:metabolism / Q000473:pathology*; D045744:Cell Line, Tumor; D002465:Cell Movement; D058750:Epithelial-Mesenchymal Transition; D006258:Head and Neck Neoplasms / Q000378:metabolism / Q000473:pathology*; D006801:Humans; D008175:Lung Neoplasms / Q000378:metabolism* / Q000556:secondary*; D051379:Mice; D009361:Neoplasm Invasiveness; D009368:Neoplasm Transplantation; D014157:Transcription Factors / Q000378:metabolism*
chemical_list: C581727:JunB protein, human; D014157:Transcription Factors