Tumor Survey--Cancer Genes Cataloged.

Good background info for cancer research.

Tumour survey unearths wealth of mutants
Cataloguing cancer genes may pay dividends.
Helen Pearson

A hunt through thousands of human genes has turned up nearly 200 that are altered in breast and colon cancer. These genes might be useful for diagnosing cancer or as new targets for drugs.

The findings suggest that a US$1.5-billion initiative funded by the US government to decode the 'cancer genome' could throw up useful leads — and goes some way towards appeasing the project's critics.

Cancer arises when cells rack up mutations in a number of their genes, and begin to divide uncontrollably. Researchers have already identified some of the genes involved in this process by cherry-picking promising candidates — but there are thought to be many, many more.

In the latest study, researchers searched for culprits by determining the genetic sequence of some 13,000 genes found in 11 breast tumours and 11 colorectal tumours that had been preserved for study. They then looked for differences in the genes between cancerous and normal tissues, and cross-checked the result with an additional bank of tumours from 24 breast or colorectal cancers.

The trawl unearthed a total of 189 genes that were mutated in the tumours and are suspected to be a cause of cancer; the majority of these had not been implicated in cancer before.

Fickle enemy

The study confirms that cancer is a fiendishly fickle enemy. The team found that breast and colon tumours harbour almost completely different mutations — in fact, only two mutated genes were shared between them. Cancers in other tissues might also be driven by a different spectrum of mutations.

In addition, the team found that no two tumours are exactly alike. All in all, the researchers estimate that a typical breast tumour carries mutations in more than 100 genes. Some 20 of these might be involved in causing the cancer, they say. Less than half of these are likely to be found in another breast tumour. The study is published in Science1.

SOURCE- Nature.com