1: Nat Cell Biol 2000 Jun;2(6):339-345 Related Articles, Books

Nitric oxide upregulates expression of DNA-PKcs to protect cells from DNA-damaging anti-tumour agents.

Xu W, Liu L, Smith GC, Charles lG

The Wolfson Institute for Biomedical Research, The Cruciform Building, University College London, Gower Street, London WC1E 6BT, UK.

[Record supplied by publisher]

Nitric-oxide synthase (NOS) activity has been detected in many human tumours, although its function is unclear. Here we show that exposure of cells to nitric oxide (NO) results in a 4-5-fold increase in expression of the DNA-dependent protein-kinase catalytic subunit (DNA-PKcs), one of the key enzymes involved in repairing double-stranded DNA breaks. This NO-mediated increase in enzymatically active DNA-PK not only protects cells from the toxic effects of NO, but also provides crossprotection against clinically important DNA-damaging agents, such as X-ray radiation, adriamycin, bleomycin and cisplatin. The NO-mediated increase in DNA-PKcs described here demonstrates the presence of a new and highly effective NO-mediated mechanism for DNA repair.

PMID: 10854324


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