title: Semaphorin7A Promotion of Tumoral Growth and Metastasis in Human Oral Cancer by Regulation of G1 Cell Cycle and Matrix Metalloproteases: Possible Contribution to Tumoral Angiogenesis.
abstract: BACKGROUND
  Semaphorins (SEMAs) consist of a large family of secreted and membrane-anchored proteins that are important in neuronal pathfinding and axon guidance in selected areas of the developing nervous system. Of them, SEMA7A has been reported to have a chemotactic activity in neurogenesis and to be an immunomodulator; however, little is known about the relevance of SEMA7A in the behaviors of oral squamous cell carcinoma (OSCC).
  
  
  METHODS
  We evaluated SEMA7A expression in OSCC-derived cell lines and primary OSCC samples using quantitative reverse transcriptase-polymerase chain reaction, immunoblotting, and semiquantitative immunohistochemistry (sq-IHC). In addition, SEMA7A knockdown cells (shSEMA7A cells) were used for functional experiments, including cellular proliferation, invasiveness, and migration assays. We also analyzed the clinical correlation between SEMA7A status and clinical behaviors in patients with OSCC.
  
  
  RESULTS
  SEMA7A mRNA and protein were up-regulated significantly (P<0.05) in OSCC-derived cell lines compared with human normal oral keratinocytes. The shSEMA7A cells showed decreased cellular growth by cell-cycle arrest at the G1 phase, resulting from up-regulation of cyclin-dependent kinase inhibitors (p21Cip1 and p27Kip1) and down-regulation of cyclins (cyclin D1, cyclin E) and cyclin-dependent kinases (CDK2, CDK4, and CDK6); and decreased invasiveness and migration activities by reduced secretion of matrix metalloproteases (MMPs) (MMP-2, proMMP-2, pro-MMP-9), and expression of membrane type 1- MMP (MT1-MMP). We also found inactivation of the extracellular regulated kinase 1/2 and AKT pathways, an upstream molecule of cell-cycle arrest at the G1 phase, and reduced secretion of MMPs in shSEMA7A cells. sq-IHC showed that SEMA7A expression in the primary OSCCs was significantly (P = 0.001) greater than that in normal counterparts and was correlated with primary tumoral size (P = 0.0254) and regional lymph node metastasis (P = 0.0002).
  
  
  CONCLUSIONS
  Our data provide evidence for an essential role of SEMA7A in tumoral growth and metastasis in OSCC and indicated that SEMA7A may play a potential diagnostic/therapeutic target for use in patients with OSCC.
authors.affiliation: Department of Oral Science, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba, 260-8670, Japan.
authors.forename: Tomoaki
authors.initials: T
authors.lastname: Saito
authors.affiliation: Department of Dentistry and Oral-Maxillofacial Surgery, Chiba University Hospital, 1-8-1 Inohana, Chuo-ku, Chiba, 260-8670, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Kasamatsu
authors.affiliation: Division of Oral Surgery and Oral Implant Center, Funabashi Central Hospital, 6-13-10 Kaijin, Funabashi, Chiba, 273-8556, Japan.
authors.forename: Katsunori
authors.initials: K
authors.lastname: Ogawara
authors.affiliation: Department of Oral Science, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba, 260-8670, Japan.
authors.forename: Isao
authors.initials: I
authors.lastname: Miyamoto
authors.affiliation: Department of Molecular Virology, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba, 260-8670, Japan.
authors.forename: Kengo
authors.initials: K
authors.lastname: Saito
authors.affiliation: Division of Oral Surgery, Chiba Rosai Hospital, 2-16 Tatsumidaihigashi, Ichihara, Chiba, 290-0003, Japan.
authors.forename: Manabu
authors.initials: M
authors.lastname: Iyoda
authors.affiliation: Department of Environmental Health Science, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba, 260-8670, Japan.
authors.forename: Takane
authors.initials: T
authors.lastname: Suzuki
authors.affiliation: Department of Dentistry and Oral-Maxillofacial Surgery, Chiba University Hospital, 1-8-1 Inohana, Chuo-ku, Chiba, 260-8670, Japan.
authors.forename: Yosuke
authors.initials: Y
authors.lastname: Endo-Sakamoto
authors.affiliation: Department of Clinical Oncology, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba, 260-8670, Japan.
authors.forename: Masashi
authors.initials: M
authors.lastname: Shiiba
authors.affiliation: Department of Oral Science, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba, 260-8670, Japan; Department of Dentistry and Oral-Maxillofacial Surgery, Chiba University Hospital, 1-8-1 Inohana, Chuo-ku, Chiba, 260-8670, Japan.
authors.forename: Hideki
authors.initials: H
authors.lastname: Tanzawa
authors.affiliation: Department of Oral Science, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba, 260-8670, Japan; Department of Dentistry and Oral-Maxillofacial Surgery, Chiba University Hospital, 1-8-1 Inohana, Chuo-ku, Chiba, 260-8670, Japan.
authors.forename: Katsuhiro
authors.initials: K
authors.lastname: Uzawa
mesh_terms: D002294:Carcinoma, Squamous Cell / Q000235:genetics / Q000473:pathology; D059447:Cell Cycle Checkpoints / Q000235:genetics; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000235:genetics; D049109:Cell Proliferation / Q000235:genetics*; D019938:Cyclin D1 / Q000235:genetics; D019927:Cyclin E / Q000235:genetics; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000235:genetics; D050760:Cyclin-Dependent Kinase Inhibitor p27 / Q000235:genetics; D018844:Cyclin-Dependent Kinases / Q000235:genetics; D015536:Down-Regulation / Q000235:genetics; D016193:G1 Phase / Q000235:genetics*; D006801:Humans; D020935:MAP Kinase Signaling System / Q000235:genetics; D020782:Matrix Metalloproteinases / Q000235:genetics*; D009062:Mouth Neoplasms / Q000235:genetics* / Q000473:pathology; D009361:Neoplasm Invasiveness / Q000235:genetics / Q000473:pathology; D009362:Neoplasm Metastasis / Q000235:genetics* / Q000473:pathology; D009389:Neovascularization, Pathologic / Q000235:genetics* / Q000473:pathology; D051057:Proto-Oncogene Proteins c-akt / Q000235:genetics; D039961:Semaphorins / Q000235:genetics*; D015854:Up-Regulation / Q000235:genetics
chemical_list: D019927:Cyclin E; D050759:Cyclin-Dependent Kinase Inhibitor p21; D039961:Semaphorins; D019938:Cyclin D1; D050760:Cyclin-Dependent Kinase Inhibitor p27; D051057:Proto-Oncogene Proteins c-akt; D018844:Cyclin-Dependent Kinases; D020782:Matrix Metalloproteinases