title: Interleukin-8 production in response to tumor necrosis factor-alpha by cholesteatoma keratinocytes in cell culture.
abstract: OBJECTIVE
  Keratinocytes harvested from acquired cholesteatoma and grown in cell culture will demonstrate increased interleukin-8 (IL-8) production in response to tumor necrosis factor (TNF)-alpha as compared with a control keratinocyte cell line. Immunohistochemical studies have identified IL-8 and TNF-alpha, mediators of bony destruction, in tissue samples of cholesteatoma. TNF-alpha stimulates IL-8 production in healthy epidermal keratinocyte cell lines. It is not known whether TNF-alpha stimulates IL-8 production in cultured cholesteatoma keratinocytes.
  
  
  METHODS
  Prospective controlled tissue culture experiment.
  
  
  METHODS
  Tissue from an acquired cholesteatoma was dissociated and grown in keratinocyte serum-free media for 8 weeks. Cholesteatoma keratinocytes and a control cell line of skin epidermal keratinocytes were treated with TNF-alpha. Conditioned media were harvested; production of IL-8 was measured by enzyme-linked immunosorbent assay, and cell counts were performed.
  
  
  RESULTS
  At a zero concentration of TNF-alpha, mean production of IL-8 by cholesteatoma keratinocytes was 39,809 pg/mL/24hr/1 × 10(6) cells versus 1,907 pg/mL/24hr/1 × 10(6) cells from skin epidermal keratinocytes, a statistically significant difference (P < .05). The cholesteatoma keratinocytes showed a 2.1-fold increase in response to 2 pg/mL of TNF-alpha and a 2.44-fold increase in response to 20 pg/mL of TNF-alpha. The skin epidermal keratinocyte cell line demonstrated a 1.07- and 1.13-fold increase to respective concentrations of TNF-alpha.
  
  
  CONCLUSIONS
  Cholesteatoma keratinocytes appear to retain cell signaling characteristics in vitro that distinguish them from skin epidermal keratinocytes. This finding may indicate that cholesteatoma keratinocytes undergo a change in behavior in vivo that is preserved after the cells are removed from the inflammatory environment of the middle ear.
authors.affiliation: Department of Otolaryngology, University of Minnesota, Minneapolis, Minnesota 55455-0392, USA. hilt0054@umn.edu
authors.forename: Christopher W
authors.initials: CW
authors.lastname: Hilton
authors.forename: Frank G
authors.initials: FG
authors.lastname: Ondrey
authors.forename: Beverley R
authors.initials: BR
authors.lastname: Wuertz
authors.forename: Samuel C
authors.initials: SC
authors.lastname: Levine
mesh_terms: D000328:Adult; D002478:Cells, Cultured; D002781:Cholesteatoma / Q000378:metabolism*; D004817:Epidermis / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D016209:Interleukin-8 / Q000096:biosynthesis*; D015603:Keratinocytes / Q000378:metabolism*; D008297:Male; D011446:Prospective Studies; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*
chemical_list: D016209:Interleukin-8; D014409:Tumor Necrosis Factor-alpha