WASHINGTON, Oct. 3 (Xinhua) -- U.S. and British researchers said Thursday they have identified a new source of cancer triggers in the little-explored regions of genome previously considered as "junk."
Researchers from the University of Yale, the Wellcome Trust Sanger Institute and other institutions, brought together data from two large-scale genome analysis projects, known as the 1000 Genomes project and the ENCODE project, to study non-coding DNA regions and their relation to disease risk.
Unlike the coding region of the genome where 23,000 protein- coding genes lie, the non-coding region, which makes up 98 percent of our genome, is poorly understood.
The team found that some non-coding DNA regions showed almost the same low levels of variation as protein-coding genes, and called these "ultrasensitive" regions.
Within the ultrasensitive regions, they looked at specific single DNA letters that, when altered, caused the greatest disturbance to many genes, resulting in disease.
They integrated all this information to develop a computer system called FunSeq, which prioritizes genetic variants in the non-coding regions based on their predicted impact on human disease.
The team applied FunSeq to 90 cancer genomes including breast cancer, prostate cancer and brain tumors, and found nearly 100 potential non-coding cancer drivers.
Among the new discoveries was a single DNA letter change that seems to have great impact on the development of breast cancer. The single letter change occurs in an ultrasensitive region central to a network of many related genes, the researchers said.
"Our technique allows scientists to focus in on the most functionally important parts of the non-coding regions of the genome," Professor Mark Gerstein, senior author from the University of Yale said in a statement. "This is not just beneficial for cancer research, but can be extended to other genetic diseases too."
The findings were published in the U.S. journal Science.