DNA double-strand breaks induced in normal human cells during the repair of ultraviolet light damage.
AUTOR(ES)
Bradley, M O
RESUMO
DNA double-strand breaks (DSBs) are formed in normal human IMR-90 cells during repair incubation after 100 and 300 J.m-2 of ultraviolet light. By contrast, no DSBs are formed after exposure to ultraviolet light in human XPA cells (from a patient with xeroderma pigmentosum complementation group A), which are unable to excise pyrimidine dimers. The DSBs are not due to immediate cell death, because all the cells excluded trypan blue at the time of assay and because XPA cells, which are much more sensitive to ultraviolet light than are IMR-90 cells, did not form DSBs after exposure to ultraviolet light. The DSBs do not appear to be due to either DNA synthesis or cellular single-strand endonucleases. We suggest that repair-induced DSBs would be potent lesions that might lead to cytotoxicity, chromosome aberrations, deletion mutations, and perhaps cellular transformation.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=319622Documentos Relacionados
- Molecular recombination and the repair of DNA double-strand breaks in CHO cells.
- In vitro repair of complex unligatable oxidatively induced DNA double-strand breaks by human cell extracts
- Repair of DNA double-strand breaks in Escherichia coli cells requires synthesis of proteins that can be induced by UV light.
- Visualization of Repair of Double-Strand Breaks in the Bacteriophage T7 Genome without Normal DNA Replication
- Multiple Pathways for Repair of DNA Double-Strand Breaks in Mammalian Chromosomes