Breast cancer may use similar tools to a word processing computer programme to wreak havoc in the body, a study suggests.
The discovery could lead to new drugs to fight breast cancer
Scientists have discovered that the disease "cuts and pastes" genes to create dangerous new combinations of DNA.
They believe this process, known as chromosome rearrangement, plays a key role in spreading the disease.
The discovery could help in the development of new drugs to fight breast cancer.
Scientists at the Hutchison MRC Research Centre at the University of Cambridge and the Institut Paoli-Calmettes in Marseilles tested the impact of breast cancer on key genes.
They labelled genes with brightly coloured fluorescent dye to enable them to track them more easily.
They discovered that a gene called heregulin had been cut from a chromosome and in its place another piece of DNA had been pasted in.
They found the rearrangement in cells from five different breast tumours and two pancreatic tumours.
The scientists said this type of chromosome rearrangement may help to spread cancer.
In healthy tissue, heregulin plays an important role in encouraging cells to grow and divide.
Cutting and pasting the gene to a new position may make it over-active, or make it active in the wrong kind of cell, sending the growth of cancer cells spiralling out of control.
It could also lead to the creation of a hybrid gene, with powerful cancer-causing properties.
"What we've found is that in breast cancer the rearrangement of chromosomes isn't random, but that a particular rearrangement happens over and over again, suggesting that it plays a key role in the development of the disease," said Dr Paul Edwards of the Hutchison MRC Research Centre.
"Moving bits of gene around can cause real problems. Understanding how our genes can be mixed around during the development of cancer is crucial if we are to identify new targets for anti-cancer drugs."
Professor Robert Souhami, director of clinical research at Cancer Research UK, which funded the study, said the discovery could help in the development of new drugs.
"If a genetic fault happens again and again in cancer, it's an indication that the fault is making a real contribution to the disease's development," he said.
"Identifying such cancer-causing errors, and working out how they might be contributing to cancer, is an exciting area of research that may bring us new targets for anti-cancer drugs."
The study is published in the journal Genes, Chromosomes and Cancer.