Canine, human genes spur drive to find brain cancer cure

Canine and human genes are spurring the researchers' drive to find a cure for brain cancer.

Pinpointing genes involved in human brain cancer can be like looking for a needle in a haystack, and sometimes the needle you find may not be the right one.

By comparing human and canine genomes, researchers have discovered that a gene believed to be involved in meningiomas -- tumours that affect the thin covering of the human brain -- may not be the key to tumour formation as previously thought, and they've narrowed the search for the real culprit.

Meningiomas are intracranial tumours, meaning that they do not grow within brain tissue itself, but in the space between the brain and the skull.

In humans, they are associated with genetic defects of large segments of chromosomes, which makes isolating the specific genes involved extremely difficult.

Humans suffering from meningioma frequently lose one copy of almost the entire length of human chromosome 22. This chromosome is made of almost 50 million base pairs of DNA that code for more than 500 genes.

"The dog has been man's best friend for centuries, and now the genome of the dog could well be man's next best friend," says Matthew Breen, professor of genomics at North Carolina State University (NCSU).

"With so much genetic material to consider, one can see why figuring out which genes play a key role in meningiomas is extremely difficult," says Breen, according to a NCSU release.

"By looking at tumours seen in both humans and dogs we have a simple way to narrow the search: we compare the affected areas of a human chromosome with related areas on dog chromosomes.

"This works because dogs and humans are genetically similar and both get the same kinds of cancers. While we share much of our genetic material, the DNA of a dog is organised differently to our own and this makes it possible to isolate smaller 'shared' regions of genetic data rather than looking at an entire chromosome," concluded Breen.

Last updated on Jul 8^th, 2009 at 12:02 pm IST--IANS