Abstract
Nonspecific chromosomal aberrations (CAs) are analyzed by microscopic scoring of metaphase nuclei and they include fragmented, missing, or fused chromosomal segments which may not be clonally expanded but remain in lymphocytes for their life-time. CAs are a marker of cancer risk and many specific CAs are believed to be causative events in malignant transformation.
However, it has recently been realized that, instead of direct DNA damage, mechanisms associated with telomere biology are important contributors to formation of CAs, preferentially of CSA type. In this study, we measured relative telomere length (RTL) in lymphocytes of healthy volunteers whose CAs have been quantified and classified as either CSA or CTA.
The median RTL was 1.28 for 48 subjects showing no CAs, and 1.19 for 47 individuals with a total of more than 2 CAs (P=0.03). Further decreased median RTL (1.12) was recorded in 68 individuals with CSAs (P=0.001).
These results, together with similar data by Li et al. (2013), provide strong evidence that telomere biology contributes to CA formation, particularly of the CSA type, in healthy individuals and that direct genotoxic mechanisms are not the only causal pathways.