Faster biological ageing linked to increased cancer risk
An international team of scientists involving researchers from Karolinska Institutet has found new evidence that links faster 'biological' ageing to the risk of developing several age-related diseases – including heart disease, multiple sclerosis and various cancers.
The study involved scientists in 14 centres across 8 countries, working as part of the European ENGAGE consortium. The research is published online in the journal Nature Genetics.
The project studied a feature of chromosomes called telomeres. Telomeres sit on the end of our chromosomes the strands of DNA stored in the nucleus of cells. The telomeres shorten each time a cell divides to make new cells, until they reach a critical short length and the cells enter an inactive state and then die. Therefore telomeres shorten as an individual gets older. But, individuals are born with different telomere lengths and the rate at which they subsequently shorten can also vary. The speed with which telomeres wear down is a measure of 'biological ageing'.
In the current study, the research team measured telomere lengths in over 48,000 individuals and looked at their DNA and identified seven genetic variants that were associated with telomere length. They then asked the question whether these genetic variants also affected risk of various diseases. As DNA cannot be changed by lifestyle or environmental factors, an association of these genetic variants which affect telomere length with a disease also would suggest a causal link between telomere length and that disease.
The scientists found that the variants were indeed linked to risk of several types of cancers including colorectal cancer as well as diseases like multiple sclerosis and celiac disease. Most interestingly, the authors found that in aggregate the seven variants also associated with risk of coronary artery disease which can lead to heart attacks.
ENGAGE stands for European Network for Genetic and Genomic Epidemiology, and is financed by the European Union's 7th Frame programme. The current study was led by scientists at the University of Leicester in the UK. Leader of the Swedish part of the study has been Professor Nancy Pedersen at the Department of Medical Epidemiology and Biostatistics of Karolinska Institutet.
Identification of seven loci affecting mean telomere length and their association with disease.
Nat. Genet. 2013 Apr;45(4):422-7, 427e1-2