Harvard Medical School researchers have identified a DNA segment on chromosome 8 that is a major risk factor for prostate cancer, especially in African American men. The paper appears in the August 21 electronic edition of the Proceedings of the National Academy of Sciences (also see PNAS's news tip below).
"This paper identifies a genetic risk factor that about doubles the likelihood of prostate cancer in younger African American men," says principal investigator David Reich, PhD, Harvard Medical School assistant professor of genetics with the HMS Department of Genetics and the Broad Institute. "This finding may explain why younger African Americans have an increased risk for prostate cancer than do other populations--and may also explain why this increased risk in African Americans attenuates with older age."
"This is one of the first genetic risk factors found that is responsible for an appreciable fraction of sporadic prostate cancer cases, particularly for the African American population," says lead author Matthew Freedman, Harvard Medical School instructor of medicine at the Dana-Farber Cancer Institute and the Broad Institute "Interestingly, we found that this region also confers risk for prostate cancer for diverse ethnic groups. The actual gene, however, remains to be identified."
The researchers used their newly developed method of "admixture mapping" to screen through the genome in African Americans (who have both African and European ancestry), searching for the segments where individuals with disease have more of one ancestry than the average. The key epidemiological fact is that prostate cancer occurs approximately 1.6-fold times more often in African Americans than in other populations. This prompted the hypothesis that there is a genetic risk factor for prostate cancer that occurs at higher frequency in African than in other populations, and that can be found by searching for a region where the proportion of African ancestry is higher than the genome average.
Reich, Freedman and their colleagues studied 1,597 African Americans with prostate cancer. They found a section of the genome in the patients that had much more than the average proportion of African ancestry, rising from 78 percent to about 85 percent. The risk factor is localized to a tiny fraction (about a thousandth) of the genome, a section on chromosome 8 containing just 9 genes.
A particularly exciting aspect of this work is that in May a separate research team also identified a genetic variant occurring within the same region, which increases risk for prostate cancer. The study by Reich and colleagues makes two additional advances. One important result is that the genetic risk factor is more important for individuals with younger age. Second, they show that the specific genetic variant reported in the earlier paper can explain only at most a small fraction of the increased risk to African Americans. Thus, major unidentified risk factors remain to be found.
Press Tip from the Proceedings of the National Academy of SciencesPress Summary:
John Lacey | EurekAlert!
During HIV infection, antibody can block B cells from fighting pathogens
14.08.2018 | NIH/National Institute of Allergy and Infectious Diseases
First study on physical properties of giant cancer cells may inform new treatments
14.08.2018 | Brown University
Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.
When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...
Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.
Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....
Proteins must be folded correctly to fulfill their molecular functions in cells. Molecular assistants called chaperones help proteins exploit their inbuilt folding potential and reach the correct three-dimensional structure. Researchers at the Max Planck Institute of Biochemistry (MPIB) have demonstrated that actin, the most abundant protein in higher developed cells, does not have the inbuilt potential to fold and instead requires special assistance to fold into its active state. The chaperone TRiC uses a previously undescribed mechanism to perform actin folding. The study was recently published in the journal Cell.
Actin is the most abundant protein in highly developed cells and has diverse functions in processes like cell stabilization, cell division and muscle...
Scientists have discovered that the electrical resistance of a copper-oxide compound depends on the magnetic field in a very unusual way -- a finding that could help direct the search for materials that can perfectly conduct electricity at room temperatur
What happens when really powerful magnets--capable of producing magnetic fields nearly two million times stronger than Earth's--are applied to materials that...
The quality of materials often depends on the manufacturing process. In casting and welding, for example, the rate at which melts solidify and the resulting microstructure of the alloy is important. With metallic foams as well, it depends on exactly how the foaming process takes place. To understand these processes fully requires fast sensing capability. The fastest 3D tomographic images to date have now been achieved at the BESSY II X-ray source operated by the Helmholtz-Zentrum Berlin.
Dr. Francisco Garcia-Moreno and his team have designed a turntable that rotates ultra-stably about its axis at a constant rotational speed. This really depends...
08.08.2018 | Event News
27.07.2018 | Event News
25.07.2018 | Event News
14.08.2018 | Information Technology
14.08.2018 | Life Sciences
14.08.2018 | Life Sciences