Reduction of ultraviolet light-induced DNA damage in human colon cancer cells treated with a lactoferrin-derived peptide
Author
Summary, in English
Treatment of Caco-2 cells with the peptide lactoferricin(4-14), results in reduction of the growth rate by prolongation of the S phase of the cell cycle. Lactoferricin(1-25) is formed in the gut by cleavage from lactoferrin and the bioactive amino acids are found within lactoferricin(4-14). Our hypothesis is that the reduction of the rate of S phase progression may result in increased DNA repair. To test this hypothesis, Caco-2 cells were subjected to UV light that caused DNA lesions and then the cells were grown in the absence or presence of 2.0 mu M lactoferricin(4-14). Evaluation of DNA strand breaks using the comet assay showed that lactoferricin(4-14) treatment indeed resulted in a reduction of comets showing damaged DNA. In the search for a mechanism, we have investigated the levels of several proteins involved in cell cycle regulation, DNA replication, and apoptosis using Western blot. Lactoferricin(4-14) treatment resulted in an increased expression of flap endonuclease-1 pointing to increased DNA synthesis activity. Lactoferricin(4-14) treatment decreased the expression of the proapoptotic protein B-cell lymphoma 2-associated X protein (or Bax), indicating decreased cell death. As we have found previously, lactoferricin(4-14) treatment reduced the expression of cyclin E involved in the G(1)/S transition. Immunofluorescence microscopy showed that a lower gamma-H2AX expression in lactoferricin(4-14)-treated cells, pointing to more efficient DNA repair. Thus, altogether our data show that lactoferricin(4-14) treatment has beneficial effects.
Department/s
- Department of Food Technology, Engineering and Nutrition
- Functional zoology
Publishing year
2012
Language
English
Pages
5552-5560
Publication/Series
Journal of Dairy Science
Volume
95
Issue
10
Document type
Journal article
Publisher
American Dairy Science Association
Topic
- Food Engineering
- Zoology
Keywords
- DNA strand break
- DNA repair
- comet assay
- lactoferricin(4-14)
Status
Published
ISBN/ISSN/Other
- ISSN: 1525-3198