Scientists at deCODE genetics and colleagues from the US and ten European countries announced a long-awaited first in cancer research: the discovery of common single-letter variations in the human genome (SNPs) linked to susceptibility not of one, but several different types of cancer, including those of lung, bladder, prostate, skin and cervix.
Over the past two years, deCODE has led a wave of discoveries by scientists around the world of common SNPs conferring risk of many major types of cancer. Yet without exception, these SNPs have been linked to cancer of only one or at most two tissue types or organs. The SNPs published, located near each other on chromosome 5p15, may therefore help to tag major biological mechanisms underlying cancer suseptibility more generally. The paper, entitled "Sequence variants at the TERT-CLPTM1L locus associate with many cancer types," is published in the online edition of Nature Genetics at www.nature.com/ng, and will appear in an upcoming print edition of the journal, according to a deCODE press release.
"Today's findings demonstrate the power of using genetics to advance our understanding of the biology of cancer and to discover new strategies for assessing and reducing risk. Our next task is to discover how these SNPs affect susceptibility. One plausible, but as yet unproven, explanation is that these variants provide a genetic background that determines how our bodies respond to environmental risk factors. A thread connecting these different cancer types is that most have important known environmental risk factors and all tend to arise in the tissue layers directly exposed to the environment," said Kari Stefansson, CEO of deCODE and senior author on the paper.
Kari continued, "One of the SNPs we have discovered is in a gene involved in determining the length of the telomeres, or the tail ends of chromosomes. Shorter telomeres have recently been linked to risk of certain cancers, and telomeres are known to become shorter with the accumulation of environmental insults over time. These findings may point us towards a means of addressing these risks by altering our lifestyle or by helping to identify targets for new drugs. We are integrating the SNPs into deCODEme, and into our deCODEme Cancer Scan launched."