A new study of mutations in cancer genomes shows how researchers can begin to distinguish the 'driver' mutations that push cells towards cancer from the 'passenger' mutations that are a by-product of cancer cell development. The study also shows that at least one in nine genes can be removed without killing human cells.
Many cancer genomes are riddled with mutations. The vast majority of these are likely to be passengers mutations that don't contribute to the development of cancer but have occurred during the growth of the cancer while a small minority are the critical drivers. The challenge of efficiently picking out the guilty drivers in the huge identification parade presented by the set of abnormalities found in a cancer genome is yet to be fully answered.
"It is essential that we can distinguish the drivers from the passengers because knowing the driver mutations and hence the critical genes they are in leads to understanding of the cellular processes that have been subverted in cancers and hence to new drugs," explains Professor Mike Stratton, senior author on the study from the Wellcome Trust Sanger Institute. "Our study provides one example of how researchers can sift through the large numbers of a particular type of mutation present in cancer genomes in order to distinguish drivers from passengers."
One class of cancer gene called a tumour suppressor gene inhibits tumour formation, acting as a brake on the process. This type of gene has to be inactivated in or deleted from the genome of the cancer cell in order to release the brake, allowing cancer to develop. The process that inactivates a tumour suppressor gene often involves deletion of both copies of the gene in the cancer (one copy originally inherited from the mother and one from the father). Therefore, in the past finding regions in which both copies of a gene are removed in many cancer cases has proven to be a fruitful way of pinpointing the location of new tumou
|Contact: Don Powell|
Wellcome Trust Sanger Institute