------ Research Unlocks Genetic Secret of Skin Cancer's Spread

By Jeff Donn
　　The Associated Press
　　Two research teams have identified genes that appear to make skin cancer spread, raising the prospect of quicker diagnosis and better treatments for the most dangerous tumors.
　　The two groups separately analyzed a type of cancer known as melanoma. Each study identified a set of genes that are active in highly invasive growths. Some genes were common to both studies.
　　“For 100 years we’ve looked at melanomas through the lens of a microscope and wondered how tumors that looked so similar can act so different. Now we’ve used the lens of genetics,”?said Jeffrey Trent, a senior researcher at the National Human Genome Research Institute in Bethesda, Md.
　　Both groups used a technique called gene expression profiling. Glass slides holding thousands of bits of DNA are exposed to genetic material from tumor cells. Byproducts of the cells?genes stick to the DNA on the slide. The technique tells which genes are switched on in the tumor cells and how active they are.
　　Trent’s team found up to 200 genes associated with highly invasive melanoma cells.
　　The second study group, led by scientists at the Massachusetts Institute of Technology, narrowed down their invasive set of genes to just 32.
　　They went on to test one of them, known as RhoC, in mice to check if it can make melanomas more invasive. They found that the most benign melanomas became 50 times more invasive with the active gene, MIT cell biologist Richard Hynes said. Highly invasive growths became 80 percent less so when the gene was blocked.
　　The findings were being published Thursday in the journal Nature.
　　Hynes said such work will help lead to genetic tests that could identify which patients are most at risk, and help researchers identify new targets for therapies focusing on the most malignant tumors.

　　(From ABCNEWS.com)