One of the largest surveys of mutations in human cancers is reported online in Nature Genetics. The study provides a preview of results that may be generated by even larger projects such as The Cancer Genome Atlas, set to begin soon.
Previous attempts at cataloguing mutations in different types of cancer have relied on DNA sequencing, which can be too expensive when applied to a large number of tumors. Levi Garraway and colleagues applied a previously developed technique called mass spectrometric genotyping to identify the frequency and distribution of 238 known mutations in 17 oncogenes in 1,000 tumors. The genotyping approach is more sensitive than the sequencing approach, identifying more mutations, and simultaneously detects mutations in multiple oncogenes in a cost-effective manner.
The authors report that mutations in three of the oncogenes were not found in any of the tumors, while mutations in the other genes were observed in only 30% of the tumors, indicating that many cancer-causing events remain to be discovered. There were relatively few examples where a specific mutation was found more than once, suggesting that mutations occurring at high frequency will be uncommon.
Levi Garraway (Dana-Farber Cancer Institute, Boston, MA, USA)
Abstract available online.
(C) Nature Genetics press release.
Message posted by: Trevor M. D'Souza