A systematic effort to test every human gene for connections to cancer has landed a catch earlier than expected. While still testing their strategies and equipment for analyzing DNA, scientists have identified a gene that could play a role in many cases of malignant melanoma, the most deadly form of skin cancer.
The discovery is the first success of the Cancer Genome Project, a venture financed by the Wellcome Trust, a British foundation, and led by investigators at the Sanger Institute in Hinxton, England. The suspicious gene, BRAF, was examined early in the project because the protein it encodes participates in a cascade of cell-growth signals that are frequently perturbed in cancer cells.
In the June 27 Nature, the researchers report that six out of the nine melanoma-tumor samples they examined contained mutations in BRAF. More than 50 percent of the laboratory melanoma cell lines they tested also had mutations in the gene. The investigators found BRAF mutations in a range of other human cancers, although the gene alterations weren’t as frequent.
Most of the mutations in BRAF alter its protein so that it continuously prods cells with a growth signal. Agents that inhibit the protein might therefore be potential cancer drugs.