Different DNA-PKcs functions in the repair of radiation-induced and spontaneous DSBs within interstitial telomeric sequences.

Interstitial telomeric sequences (ITSs) in hamster cells are hot spots for spontaneous and induced chromosome aberrations (CAs). Most data on ITS instability to date have been obtained in DNA repair-proficient cells. The classical non-homologous end joining repair pathway (C-NHEJ), which is the principal double strand break (DSB) repair mechanism in mammalian cells, is thought to restore the morphologically correct chromosome structure.

'Desperate house genes': the dramatic example of hypoxia.

Background: Microenvironmental conditions in normal or tumour tissues and cell lines may interfere on further biological analysis. To evaluate transcript variations carefully, it is common to use stable housekeeping genes (HKG) to normalise quantitative microarrays or real-time polymerase chain reaction results. However, recent studies argue that HKG fluctuate according to tissues and treatments.

ATR contributes to telomere maintenance in human cells.

Telomere maintenance is essential to preserve genomic stability and involves several telomere-specific proteins as well as DNA replication and repair proteins. The kinase ATR, which has a crucial function in maintaining genome integrity from yeast to human, has been shown to be involved in telomere maintenance in several eukaryotic organisms, including yeast, Arabidopsis and Drosophila. However, its role in telomere maintenance in mammals remains poorly explored.

Sequence-driven telomeric chromatin structure.

Interstitial (also called internal or intrachromosomal) telomeric sequences (ITS) are found in many organisms.(1) In hamsters, CHO cells show long (up to several Mbp) ITS(2) (Fig. 1A) which are over involved in spontaneous or radiation induced chromosome aberrations.