Research: dna deletions and cancer

10 March 2005

In the largest ever study of cancer-linked DNA deletions, researchers at the Wellcome Trust Sanger Institute and colleagues have identified 131 regions of the human genome that do not contain known cancer genes but that are lost in cancer cells.

All cancers are associated with abnormalities in DNA sequences, such as mutations in genes involved in cell division or growth control, or deletions of such genes on both copies of a chromosome (a process called homozygous deletion).

As part of the Cancer Genome Project at the Sanger Institute, researchers studied 636 cancer cell lines – cells taken from a variety of tumours and grown in culture. Some of the 281 deletions identified affected known cancer genes or 'fragile sites' in the genome. But 178 deletions, which clustered in 131 regions, did not overlap with known cancer genes.

Surprisingly, the deleted regions contain rather few genes. This suggests either that loss of many genes is not conducive to cancer development or that these 'gene-poor' regions may be more susceptible to deletion in cancer cells.

External links

• A survey of homozygous deletions in human cancer genomes (Research paper, Cox C et al.)
• The Cancer Genome Project (Wellcome Trust Sanger Institute website)