title: The protective effect of amifostine on ultraviolet B-exposed xeroderma pigmentosum mice.
abstract: BACKGROUND
  Amifostine is a pharmaceutical agent that is used clinically to counteract the side-effects of chemotherapy and radiotherapy. It acts as a free radical scavenger that protects against harmful DNA cross-linking. The purpose of this study was to determine the effect of amifostine on the development of skin cancer in xeroderma pigmentosum (XP) mice exposed to ultraviolet B radiation (UVB).
  
  
  METHODS
  Twenty-five XP mice were equally divided into five groups. Group 1 (control) received no amifostine and no UVB exposure. Group 2 also received no amifostine, but was exposed to UVB at a dose of 200 mJ/cm(2) every other day. The remaining groups were subjected to the same irradiation, but were given amifostine at a dose of 50 mg/kg (group 3), 100 mg/kg (group 4), or 200 mg/kg (group 5) immediately prior to each exposure.
  
  
  RESULTS
  No tumours were seen in the control group. The animals in group 2 (no amifostine) developed squamous cell carcinoma (SCC) at 3.5-4.5 months (mean 3.9 months). Groups 3 and 4 (low- and medium-dose amifostine) developed SCC at 4.0-7.0 months (mean 5.3 months), representing a statistically significant delay in tumour presentation (p = 0.04). An even greater delay was seen in group 5 (high-dose amifostine), which developed SCC at 7.0-9.0 months (mean 8.5 months, p < 0.001 versus groups 3 and 4). Ocular keratitis developed in all animals except the unexposed controls and the high-dose treatment group.
  
  
  CONCLUSIONS
  Treatment with amifostine significantly delays the onset of skin cancer and prevents ocular keratitis in UVB-exposed XP mice.
authors.affiliation: Division of Plastic Surgery, University of Missouri, One Hospital Dr, Columbia, MO, USA.
authors.forename: Sl
authors.initials: S
authors.lastname: Henry
authors.forename: D
authors.initials: D
authors.lastname: Christiansen
authors.forename: Fr
authors.initials: F
authors.lastname: Kazmier
authors.forename: Cl
authors.initials: C
authors.lastname: Besch-Williford
authors.forename: Mj
authors.initials: M
authors.lastname: Concannon