Monday, September 22, 2014
The genes that are involved in preserving youth and warding off ageing surprisingly could also be involved in the deadliest skin cancer, melanoma, according to an international team of researchers.
They have discovered that the genes that control the length of our telomeres, which are the “caps” on the end of our chromosomes that protect them from environmental damage from things like exposure to sunlight or cigarette smoke, could be a factor in melanoma susceptability.
Longer telomeres are usually associated with longevity while shorter ones are associated with ageing and conditions such as cancers and heart disease, but now it seems that longer telomeres actually increase the risk of melanoma.
“For the first time, we have established that the genes controlling the length of these telomeres play a part in the risk of developing melanoma,” said lead author Dr Mark Iles, from the University of Leeds in the UK.
The researchers compared 11,108 melanoma cases with 13,933 controls from Australia, Europe, Israel and the US and looked at seven known or suspected genetic variations.
The 25 percent of the sample who had the longest telomeres were found to have a 30 percent greater risk of developing melanoma compared to the quarter with the shortest telomeres.
It is the largest study ever conducted that traces the genetic basis of telomere length in melanoma.
Professor Graham Mann, chair of the University of Sydney Cancer Research Network and co-author of the study, told ninemsn that it sounds surprising given keeping our telomeres long is usually seen as a good thing.
“But cancer cells try to keep their telomeres long because they try to keep surviving and multiplying longer than they should — they have mechanisms to keep extending their telomeres,” he said.
“This new data is about people’s individual capacity to keep telomeres long, which is controlled by several genes. It suggests that people who tend to have longer telomeres have a small increase in melanoma risk compared to other people. It could be because the developing melanoma cells have a slightly easier time keeping their telomeres long in people with this tendency.”
The researchers are continuing their work to determine the cause for the link.
“More research is needed to better understand the relationship between melanoma and telomeres, but learning more about how an individual's genetic telomere profile influences their risk of developing melanoma may help us,” Dr Iles said.
“It will improve our understanding of melanoma biology and gives us a target towards developing potential treatments as well as potentially helping shape advice on what behavioural changes people might make.”
The study was published in the Journal of the National Cancer Institute.
Author: Kimberly Gillan. Approving editor: Wade O'Leary.