A mechanism-based antioxidant approach for the reduction of skin carcinogenesis.


Journal Article

Studies in our laboratories showed that overexpression of manganese superoxide dismutase (MnSOD) reduced tumor incidence in a multistage skin carcinogenesis mouse model. However, reduction of MnSOD by heterozygous knockout of the MnSOD gene (MnSOD KO) did not lead to an increase in tumor incidence, because a reduction of MnSOD enhanced both cell proliferation and apoptosis. The present study extends our previous studies in the MnSOD KO mice and shows that apoptosis in mouse epidermis occurred prior to cell proliferation (6 versus 24 hours) when treated with tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA). To investigate the possibility that a timed administration of SOD following apoptosis but before proliferation may lead to suppression of tumor incidence, we applied a SOD mimetic (MnTE-2-PyP(5+)) 12 hours after each TPA treatment. Biochemical studies showed that MnTE-2-PyP(5+) suppressed the level of protein carbonyls and reduced the activity of activator protein-1 and the level of proliferating cellular nuclear antigen, without reducing the activity of p53 or DNA fragmentation following TPA treatment. Histologic examination confirmed that MnTE-2-PyP(5+) suppressed mitosis without interfering with apoptosis. Remarkably, the incidence and multiplicity of skin tumors were reduced in mice that received MnTE-2-PyP(5+) before cell proliferation. These results show a novel strategy for an antioxidant approach to cancer intervention.

Full Text

Duke Authors

Cited Authors

  • Zhao, Y; Chaiswing, L; Oberley, TD; Batinic-Haberle, I; St Clair, W; Epstein, CJ; St Clair, D

Published Date

  • February 15, 2005

Published In

Volume / Issue

  • 65 / 4

Start / End Page

  • 1401 - 1405

PubMed ID

  • 15735027

Pubmed Central ID

  • 15735027

International Standard Serial Number (ISSN)

  • 0008-5472

Digital Object Identifier (DOI)

  • 10.1158/0008-5472.CAN-04-3334


  • eng

Conference Location

  • United States