Gene Link

Change in gene leads
to 70 percent of melanoma cases

Scientists have determined that a spontaneous change in a certain gene is involved in 70 percent of cases of melanoma, the deadliest form of skin cancer, which kills nearly 40,000 people a year worldwide.

Experts say the finding might lead to more effective drugs for melanoma, which accounts for just 11 percent of skin cancer, but is hard to treat once it has spread. It accounts for almost all deaths from skin cancer.

The discovery, published Sunday in the online version of the journal Nature, is the first fruit of the Cancer Genome Project, a spinoff of the international Human Genome Project being run by researchers at the Wellcome Trust Sanger Institute in Cambridge, England.

Cancer is the disease that lends itself best to an analysis of the human genome because all cancers are a disease of DNA, said Mike Stratton, head of the Cancer Genome Project, which aims to identify which of the 30,000 human genes are involved in cancer.

Mutations can be acquired either when DNA is damaged by such toxins as radiation, chemicals or viruses, or when mistakes are made before cell division.

Experts estimate it takes about 25 years from the first gene mutation for a tumor to appear in an adult.

"With the human DNA sequence now available to us, we have started the lengthy and daunting task of trawling through the vast tracts of genome, gene by gene, to see if we can find the abnormal genes that drive cells to behave as cancers," said Dr. Andy Futreal of the Cancer Genome Project