- Posted Sunday May 18, 2008
Genome-wide study rapidly scans DNA for clues, narrows search
Phoenix, Arizona and Queensland, Australia -- It has long been
known that prolonged exposure to the suns harmful UV rays can lead
to Melanoma, the deadliest form of skin cancer. An unanswered
question, however, is why some people are more likely to develop
melanoma than others. Despite years of research and clinical
development, melanoma incidences continue to rise around the world.
According to the National Cancer Institute, the percentage of
people in the United States who develop melanoma each year has more
than doubled in the past 30 years.
Results published today from a study led by researchers from The Translational Genomic Research Institute (TGen) in Phoenix, Arizona and The Queensland Institute of Medical Research (QIMR), Queensland, Australia, however, may yet change these statistics. The team is close to discovering a new gene that could help explain variation in melanoma risk.
In a report appearing in an Advance Online Publication (AOP) of the journal Nature Genetics, the researchers and their colleagues identify a region on chromosome 20 (20q11.22) that influences a person's risk of developing melanoma.
According to Dr Kevin Brown, TGen Investigator and the paper's co-first author, compared to other genetic research focusing on familial (or inherited) cases of melanoma, this finding holds implications for the general population
"We're closing in on genetic variants which cause 16 percent of the population to be at nearly double the increased risk of developing the disease. In public health terms, this finding is highly significant," Dr. Brown said.
The researchers narrowed the gene location through a genome-wide association study - a first in melanoma research. Genome-wide studies involve rapidly scanning DNA of many people to find genetic variations associated with a particular disease. After identifying new genetic associations, researchers can use the information to develop better strategies to detect, treat and prevent the disease.
"The aim of our work is to identify and understand the genetic factors influencing melanoma so we can better predict risk estimates," said QIMR's Dr. Stuart MacGregor, co-first author on the study. "This in turn, means people will be better informed and can take the right precautions to avoid developing this increasingly common cancer."
How The Study Works
A genome-wide association study involves scanning the DNA from two sets of individuals: those with a particular disease (cases) and those of similar individuals without the disease (controls). The DNA of each sample then undergoes examination for strategically selected markers of genetic variation, called single nucleotide polymorphisms, or SNPs. If certain genetic variations are found to be significantly more frequent in people with the disease compared to people without disease, those variations are said to be "associated" with the disease. The associated genetic variations can serve as roadmaps to the region of the human genome where the disease-causing gene resides.
The study - whose data collection began 20 years ago - involved more than 4,000 Australian samples (2,019 cases and 2,105 controls) and was a joint project between Australian, American and European research groups.
According to the National Cancer Institute's on-line booklet, What You Need to Know About Melanoma, melanoma is a form of cancer that begins in melanocytes (cells that make the pigment melanin). It may begin in a mole (skin melanoma), but can also begin in other pigmented tissues, such as in the eye or in the intestines.
Melanoma is the most serious type of cancer of the skin. Each year in the United States, more than 64,800 people learn they have melanoma and approximately 8,400 will die from the disease. The disease is particularly prevalent in the Southwest, particularly Arizona, where the incidence rate is double the national average and is becoming more common every year.
Funding for Dr. Browns lab was provided by Melanoma Research Foundation (MRF) Research Grant Program, whose purpose is to support promising medical research that will further the goal of developing an effective treatment and possible cure of malignant melanoma, while encouraging scientists and clinicians to join in this mission. The Foundation funds both junior and senior researchers. In both grant programs, emphasis will be placed on projects that explore innovative approaches to understanding melanoma and its treatment. Both basic and clinical research projects will be considered.
"Each year, we receive grant requests from some of the best and brightest melanoma researchers in the world," said Linda Pilkington, Executive Director, Melanoma Research Foundation. "The research conducted by scientists like Dr. Brown gives melanoma patients the hope they need and deserve - hopefully one day leading to a cure for this deadly disease."
The Translational Genomics Research Institute (TGen) is a non-profit 501(c)(3) organization dedicated to conducting groundbreaking research with life changing results. Research at TGen is focused on helping patients with diseases such as cancer, neurological disorders and diabetes. TGen is on the cutting edge of translational research where investigators are able to unravel the genetic components of common and complex diseases. Working with collaborators in the scientific and medical communities, TGen believes it can make a substantial contribution to the efficiency and effectiveness of the translational process. TGen's vision is of a world where an understanding of genomic variation can be rapidly translated in a manner tailored to individual patients.
Established in 1945 by the Queensland Government, The Queensland Institute of Medical Research (QIMR) is one of the largest medical research institutes in the southern hemisphere, and is recognised worldwide for the quality of its research. Originally established to further the study of tropical diseases in North Queensland, QIMR has, over its 60 years' history, broadened its scope to include the immunological, biological and molecular basis of a wide range of infectious diseases, cancers and other disorders. QIMR has also built a strong research stream in epidemiology, the study of the environmental, lifestyle and genetic factors that contribute to disease incidence among populations.
About the Melanoma Research Foundation
The Melanoma Research Foundation (MRF) is the largest private, national organization devoted to melanoma in the United States. The Foundation is committed to the support of medical research in finding effective treatments and eventually a cure for melanoma. The Foundation also educates patients and physicians about prevention, diagnosis and treatment of melanoma, while acting as an advocate for the melanoma community to raise awareness of this disease and the need for a cure. The MRF Web site is the premiere source for melanoma information seekers. More information is available at www.melanoma.org.
Phone: (602) 343-8423
E-mail: [email protected]
Felipe Beltran, QIMR Media Relations Officer
Phone: (07) 3362 0291
E-mail: [email protected]
Heather R. Huhman
Phone: (202) 742-5259
E-mail: [email protected]