1st genome map of advanced prostate cancers reveals genetic 'hypermutation'




Tue, 27 Sep 2011: 

Washington, Sept 27 (ANI): Researchers at Fred Hutchinson Cancer Research Centre and the University of Washington have conducted the first comprehensive assessment of every gene in the genome of advanced, lethal prostate cancer.


Until now, the genetic composition of such tumours had been poorly defined.<> 

In the process, they have discovered a number of potential key drivers - recurrent genetic mistakes - common to advanced prostate cancer that may contribute to disease progression.


The researchers also have identified several instances of genetic "hypermutation," a gross excess of single-letter DNA "spelling errors" that could cause the cancer to become resistant to therapies commonly used to slow the progression of advanced prostate cancer, such as androgen-blocking drugs and surgical castration.


"The most interesting finding to come out of our DNA sequencing project was the discovery of three aggressive tumour types that had 10 times the number of mutations compared to the other advanced prostate cancers we studied," said Peter S. Nelson, M.D., a member of the Hutchinson Centre's Human Biology Division.


"That was very surprising and unusual. We don't know the cause of these hypermutated tumours, but the frequency of the mutations suggests these tumours might evolve very rapidly to develop resistance to therapies," he stated.


The discovery of these genetic mutations should provide clues that illuminate why some prostate cancers are lethal, and potentially could be used to develop screening tests for early detection or drug targets to slow or halt cancer growth, Nelson added.


The findings were reported in the Proceedings of the National Academy of Sciences Early Edition, Sept. 26. (ANI)