Toronto, December 24th (IANS): Researchers at the University of Calgary have for the first time discovered seven DNA fingerprints or patterns that define human cancer risk and provide new insights into disease risk for generations.
Lifestyle or, in other words, “bad habits” is one of the textbook explanations why some people are at higher risk of cancer.
But not all smokers get lung cancer, and not all people who eat cheeseburgers get colon cancer, and “other factors” must play a role.
“This discovery rewrites the textbook’s explanation that cancer occurs because of human behavior, combined with some bad luck to involve the genome,” said University of Calgary scientist Dr. Edwin Wang.
“We believe that a baby is born with a germline genome pattern and won’t change, and that pattern is associated with a lower or higher risk of cancer,” he said in an article published in Science Advances.
The germline represents the cells that make up our children and the DNA that is passed on from parents to children.
It is the first time that scientists have described these highly specialized biological patterns for cancer risk.
Wang found that the DNA fingerprints could be divided into subgroups with different survival rates.
One of the seven germ lines offers protection against cancer and the other six germ lines show a higher cancer risk.
“It is interesting that one of these germlines protects against the development of cancer and is a common feature in our genome analysis,” noted Wang, a professor in the CSM Department of Biochemistry and Molecular Biology.
“We know that there are people who can smoke and have unhealthy lifestyles but never get cancer. This discovery could explain this phenomenon.”
For this research, Wang performed a massive systematic analysis of more than 26,000 germline genomes from individuals, about 10,000 people with cancer and the rest without.
The samples include 22 different cancers, including the lung, pancreas, bladder, breast, brain, stomach, thyroid, and bone, and a dozen more.
The control group of people without cancer included genomically sequenced groups from Sweden, England and Canada.
The huge amounts of data have been shredded by machine learning.
Wang said that between five and 10 percent of cancers are caused by specific gene mutations.
Think breast cancer and the inherited genes BRCA1 and BRCA2, a gene mutation made widely known by actress Angelina Jolie.
“We found that a DNA fingerprint in the germline genome of cancer patients was enriched ten to a hundred times, suggesting that it is a universally heritable trait that encodes cancer risk,” noted the scientist.
The research also found that another DNA fingerprint was highly enriched in cancer patients who were also tobacco smokers, suggesting that smokers with such a DNA fingerprint are at greater risk of cancer.
“I hope that more studies will be done to expand this work so that it can eventually be put into practice, so that doctors can educate patients about their cancer risk and take precautions to ensure healthy lives,” Wang said.