This
press release (HT: medGadget)
from King's College tips us off to an article in the journal, Cancer
Epidemiology Biomarkers & Prevention.
This is something that news sites picked up on.
Specifically, the authors reported a relationship between the
number of moles a person has, and the length of their telomeres.
Telomere shortening is thought to be an indicator
of aging. Nevus Size and Number Are Associated with Telomere Length and Represent Potential Markers of a Decreased Senescence In vivo
Veronique Bataille, Bernet S. Kato, Mario Falchi, Jeffrey Gardner, Masayuki Kimura, Marko Lens, Ursula Perks, Ana M. Valdes, Dot C. Bennett, Abraham Aviv and Tim D. Spector
Cancer Epidemiology Biomarkers & Prevention
doi: 10.1158/1055-9965.EPI-07-0152 16, 1499-1502, July 1, 2007
Nevus counts represent one of the strongest risk factors for melanoma. They appear in childhood and adolescence and involute from middle age onwards. Recent evidence has shown that nevus cells undergo oncogene-induced senescence involving the p16/retinoblastoma pathway. However, telomere length also influences senescence in proliferative somatic cells and varies between individuals. This study explores whether telomere length measured in white cells is associated with nevus count and size in 1,897 Caucasian women ages 18 to 79 years. Total body nevus counts were positively correlated with white cell telomere length (mean, 7.09 kbp; range, 5.09-9.37) after adjustment for age (P = 0.0001). Age-adjusted telomere length was also associated with nevus count for nevi above 5 mm in diameter (P = 0.04). Subjects in the top category for nevus count had an average age-adjusted telomere length 150 bp longer than those in the lowest category. The positive correlation between white cell telomere length and nevi number and size may reflect an increased replicative potential (reduced senescence) in individuals with longer telomeres, which may not be melanocyte specific. Understanding mechanisms influencing the induction and involution of nevi will not only help in understanding the pathophysiology of melanoma but should also shed light on the complex relationship between aging and cancer. (Cancer Epidemiol Biomarkers Prev 2007;16(7):1499–502)
Moles usually appear in when a person is young,
then become smaller and disappear with age. The study suggests that the longer telomeres may cause the moles to persist longer, because the cells retain their ability to replicate.
One way to look at it would be to say that as the cells in the mole grow old and die, cells in the rest of your body are growing old and dying. If the moles last longer, then other body tissues are lasting longer.
Telomeres are specialized DNA-protein complexes that cap the end of eukaryotic chromosomes and are essential for maintaining genome stability and integrity... Shortening of telomeres occurs naturally with successive divisions in somatic cells, whereas in the germ-line and most cancer cells, high telomerase activity allows cells to maintain long telomeres and avoid senescence.
The authors of the study are careful to avoid drawing any broad conclusions from this, in part because they only studied women, and all of them were from the UK. They add that some studies have shown a relationship between telomere shortening and cancer, while others have not.
