title: Tumor necrosis factor alpha stimulates invasion of Src-activated intestinal cells.
abstract: OBJECTIVE
  Src activation is correlated with progression of colorectal cancer (CRC). CRCs accompanied by ulcerative colitis, chronic inflammation in the colon, often have elevated Src activity, and ulcerative colitis-related CRCs are more likely to become invasive, whereas Ras activation is rarely associated with this disease. The aim of this study was to investigate the effects of a proinflammatory cytokine, tumor necrosis factor alpha (TNF-alpha), on the invasive properties of epithelial cells constitutively expressing activated Ras or Src.
  
  
  METHODS
  A cell line derived from intestinal epithelia was transfected with a v-src- or v-H-ras-expressing vector. The effect of TNF-alpha on morphologic changes in colonies cultured in soft agar was determined. Src protein kinase activity, peroxide production, E-cadherin expression levels, and the phosphorylation status of beta-catenin and E-cadherin were determined. The invasive potential of these cells was determined by measuring cell motility and using an in vitro invasion assay.
  
  
  RESULTS
  TNF-alpha altered the colony morphology of src-, but not ras-expressing cells. TNF-alpha increased peroxide production, leading to Src protein expression as well as Src activity in src transfectants. Activation of Src by TNF-alpha led to reduced E-cadherin levels and enhanced invasion of src transfectants. Pyrrolidine dithiocarbamate and herbimycin A inhibited these effects.
  
  
  CONCLUSIONS
  These results indicate that Src kinase activation enhances the response of epithelial cells to TNF-alpha leading to increased invasion through mechanisms that involve production of reactive oxygen intermediates.
authors.affiliation: Graduate School of Medicine, Department of Internal Medicine and Therapeutics, Faculty of Medicine, Osaka University, Japan.
authors.forename: Naoki
authors.initials: N
authors.lastname: Kawai
authors.forename: Shingo
authors.initials: S
authors.lastname: Tsuji
authors.forename: Masahiko
authors.initials: M
authors.lastname: Tsujii
authors.forename: Toshifumi
authors.initials: T
authors.lastname: Ito
authors.forename: Masakazu
authors.initials: M
authors.lastname: Yasumaru
authors.forename: Yoshimi
authors.initials: Y
authors.lastname: Kakiuchi
authors.forename: Arata
authors.initials: A
authors.lastname: Kimura
authors.forename: Masato
authors.initials: M
authors.lastname: Komori
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Sasaki
authors.forename: Norio
authors.initials: N
authors.lastname: Hayashi
authors.forename: Sunao
authors.initials: S
authors.lastname: Kawano
authors.forename: Raymond
authors.initials: R
authors.lastname: Dubois
authors.forename: Masatsugu
authors.initials: M
authors.lastname: Hori
mesh_terms: D000362:Agar; D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology*; D000975:Antioxidants / Q000494:pharmacology; D015820:Cadherins / Q000378:metabolism; D002461:Cell Line, Transformed; D002465:Cell Movement / Q000502:physiology*; D003598:Cytoskeletal Proteins / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000378:metabolism; D007413:Intestinal Mucosa / Q000166:cytology; D009361:Neoplasm Invasiveness / Q000503:physiopathology; D015689:Oncogene Protein p21(ras) / Q000235:genetics / Q000378:metabolism; D015688:Oncogene Protein pp60(v-src) / Q000235:genetics / Q000378:metabolism*; D018384:Oxidative Stress / Q000187:drug effects / Q000502:physiology; D019000:Phosphotyrosine / Q000378:metabolism; D011759:Pyrrolidines / Q000494:pharmacology; D051381:Rats; D013859:Thiocarbamates / Q000494:pharmacology; D015534:Trans-Activators; D014162:Transfection; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*; D014443:Tyrosine / Q000378:metabolism; D051176:beta Catenin
chemical_list: D000970:Antineoplastic Agents; D000975:Antioxidants; D015820:Cadherins; C495268:Ctnnb1 protein, rat; D003598:Cytoskeletal Proteins; D011759:Pyrrolidines; D013859:Thiocarbamates; D015534:Trans-Activators; D014409:Tumor Necrosis Factor-alpha; D051176:beta Catenin; D019000:Phosphotyrosine; C020972:pyrrolidine dithiocarbamic acid; D014443:Tyrosine; D000362:Agar; D006861:Hydrogen Peroxide; D015688:Oncogene Protein pp60(v-src); D015689:Oncogene Protein p21(ras)