Greater number of cancer genes discovered

More genes are responsible for cancer development than previously thought, it has been claimed today.

Scientists at the Wellcome Trust Sanger Institute carried out the broadest survey yet of the genetics of cancer by sequencing more than 250 million letters of DNA code, covering more than 500 genes and 200 cancers.

Published in the Nature journal, the study shows that the number of mutated genes that ‘drive’ cancer is more than researchers realised before. It also reveals that each cell carries many more ‘passenger’ mutations.

Driver mutations cause the cancer to grow whereas passengers are co-travellers that make no contribution to cancer development.

“The human genome is a vast place and this, our first deep systematic exploration in cancer, has thrown up many surprises”, said Professor Mike Stratton, co-leader of the cancer genome project at the Sanger Institute.

His research team identified possible driver mutations in 120 genes, many of which had not been seen before.

They studied a type of gene called kinases, which they claim sheds light on some of the mutations. The kinases can act as a series of relays, switching on and off in cells to control cell behaviour.

Dr Andy Futreal, another co-leader of the project, said: “For example, we found that a group of kinases involved in the fibroblast growth factor receptor signalling pathway was hit much more than we expected, particularly in colorectal cancers.”

Another of the team’s discoveries was that the mutations carry important coded messages within them and that the type of mutation varies between individual cancers.

“This study vindicates all of the effort that went into the human genome project,” commented Dr Mark Walport, director of the Wellcome Trust. “Understanding the mutations that cause cancer is crucial in order to develop accurately targeted treatments.”

Dr Francis Collins, director of the National Human Genome Research Institute at the National Institutes of Health, said: “The important and interesting data on protein kinases in this report? further encourages the conclusion that a full assault on the cancer genome will yield many opportunities to revolutionise diagnosis and treatment.”