Targeted antizyme expression in the skin of transgenic mice reduces tumor promoter induction of ornithine decarboxylase and decreases sensitivity to chemical carcinogenesis.
Journal
  Cancer research.
Citation
  Cancer Res. 61(16):6073-81
Publication date
  2001 Aug 15
Authors
  Feith DJ
Shantz LM
Pegg AE
Investigators
  Anthony E. Pegg
Lisa Shantz
Grant agencies
  National Cancer Institute
National Institute of General Medical Sciences
Grants
  NCI CA-18138
NCI CA-82768
NIGMS GM-26290
MeSH headings
  Ornithine Decarboxylase
Protein Biosynthesis
Skin
Skin Neoplasms
MeSH qualifiers
  antagonists & inhibitors
metabolism
enzymology
prevention & control
Abstract
  To directly evaluate the role of increased ornithine decarboxylase (ODC) and polyamines in mouse skin carcinogenesis, we used bovine keratin 5 (K5) and keratin 6 (K6) promoter elements to direct the expression of antizyme (AZ) to specific skin cell populations. AZ is a multifunctional regulator of polyamine metabolism that inhibits ODC activity, stimulates ODC degradation, and suppresses polyamine uptake. K5-AZ mice treated with 12-O-tetradecanoylphorbol-13-acetate (TPA) at 0 and 24 h exhibit increases in epidermal and dermal ODC activity that are reduced in magnitude. K6-AZ mice treated similarly do not show any increased ODC activity or protein after a second application due to TPA-induced expression of AZ protein. Epidermal and dermal polyamine content, particularly spermidine, is reduced in untreated K5-AZ mice and TPA-treated K5-AZ and K6-AZ mice. Susceptibility to 7,12-dimethylbenz(a)anthracene/TPA carcinogenesis was also investigated for two K6-AZ transgenic lines [K6-AZ(52) and K6-AZ(18)] and a single K5-AZ line. K6-AZ(52) mice had a substantial delay in tumor onset and a >80% reduction in tumor multiplicity compared with normal littermates. K6-AZ(18) and K5-AZ mice also developed fewer papillomas than littermate controls (35% and 50%, respectively), and the combination of these lines to produce double transgenic animals yielded an additive decrease (70%) in tumor multiplicity. These mice demonstrate for the first time that AZ suppresses tumor growth in an animal cancer model and provide a valuable model system to evaluate the role of ODC and polyamines in skin tumorigenesis.
Medline ID
  21397951