Bowel cancers reshuffle their genetic pack to cheat treatment

Bowel cancer cells missing one of three genes can rapidly reshuffle their genetic 'pack of cards' – the chromosomes that hold the cell's genetic information. This reshuffling has been previously shown to render tumours more resistant to treatment.

New research, published today in the journal Nature, shows that this genetic 'card trick' can be caused by the deletion of three genes found on one particular chromosome, a region known as '18q'.

Loss of this region is well-known in bowel cancer and the new findings help shed light on the role it plays.

Normal human cells have 46 chromosomes, each of which is a long string of DNA. But in certain bowel cancers, this number can change over time - a process called chromosomal instability. This makes the cells in a tumour incredibly diverse, and helps it become resistant to treatment. Patients whose bowel cancer cells contain particularly unstable chromosomes are known to do worse.

Lead author professor Charles Swanton (UCL Cancer Institute and Cancer Research UK's London Research Institute) says, ''Recent work from our lab and other groups has shown that the genetic landscape within a cancer is very complex, fundamentally changing our understanding of the disease.

"Too much instability prevents cancer cells from being able to function, ultimately stopping them from working normally and causing them to die. We're looking for ways to target this process and tip cancer cells over the edge," says professor Swanton.