MORE THAN A THIRD OF PROSTATE CANCER MAY BE TIED TO DNA; A TEST IS POSSIBLE Article from Reuters (Washington), 1st April 2007. By: John Lauerman |
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April 1 (Bloomberg) -- One in three prostate cancers in people of European descent and two of three in blacks have been tied to a specific DNA region in humans, potentially leading to new tests that may, within a year, pinpoint those most at risk.
The research, published today in three studies, was led by scientists at DeCode Genetics Inc., an Icelandic biotech company, Harvard University and the U.S. National Institutes of Health. About 15,000 people were studied in the reports, which linked genetic variations on the eighth human chromosome to prostate cancer, which kills about 27,000 American men a year.
The prostate is a walnut-sized gland that helps make semen. Early testing for the disease can be significant because cancers in the gland often grow slowly, and can be treated with drugs, radiation and surgery if caught early, scientists said.
"We are putting all these discoveries together in a test," said Kari Stefansson, chief executive officer for DeCode, in a March 30 telephone interview. "They'll all be together, probably in the beginning of next year."
Therapy based on the new knowledge will take longer to develop because
scientists still don't know the function of the region studied, Stefansson
said. The three studies of the chromosome region were released today
by the journal Nature Genetics.
Chromosomes are threadlike strands of DNA that exist in the nucleus
of each human cell. Chromosome eight "could be an area that affects
the activity of known cancer genes," said David Reich, an assistant
professor of genetics at Harvard and leader of one of the three studies.
Study in Iceland
Scientists from DeCode, which searches for disease-related genes in
a databank of Iceland's population, linked other areas of the region,
called 8q24, to prostate cancer in previous studies. DeCode will
release more studies in the future that may show that about half
of human prostate cancers are tied to the region in some way, Stefansson
said.
DeCode found the regions by studying about 4,500 people in Iceland using slides made by San Diego-based Illumina Inc. that are dotted with molecules that link to and identify pieces of DNA. The slides, called chips, allow scientists to find tiny DNA variations that occur most frequently in people with specific diseases.
Harvard's Reich, along with scientists across the country, studied about 7,500 American men of black, Hispanic, Japanese, Hawaiian, and European descent with and without prostate cancer. Using a similar technique, they found seven disease-related variations, five of which no one had reported before.
The study also may lead to a new understanding of how prostate cancer
occurs, the researchers said. While 8q24 doesn't have any known effect
on making protein, it may have some control over a relatively nearby
gene called "myc" that has been implicated in cancer, they
said.
"This may be a 'master region' that controls other genes," said
Stephen Chanock, head of the National Cancer Institute's pediatric oncology
branch, who led the third study. "These findings underscore the
complexity of prostate cancer, and the complexity of cancer as a disease."
To contact the reporter on this story: John Lauerman in Boston at jlauerman@bloomberg.net .