Scientists identify normal gene driving the growth and survival of melanoma cells

Dana-Farber’s Levi Garraway, M.D., Ph.D., and William Sellers, M.D., the paper’s first and senior authors, and their colleagues reported their findings in the July 7, 2005 issue of the journal Nature.

The researchers used single nucleotide polymorphism (SNP) array technology, which focuses on the building blocks of individual genes, to identify regions of chromosomes where genes were either left out or multiplied over and over – mistakes that are often associated with cancer.

When they checked the treatment outcomes of the patients from whom they took tumor samples, researchers found poorer five- year survival rates among patients whose metasases contained the overcopied or “amplified” MITF gene.

Abnormal amplification of the MITF gene was found to be associated with other genetic changes as well. They included mutations in a gene, BRAF, previously found in melanoma cells, and silencing of p16, a “tumor-suppressor” gene that normally keeps cells from dividing too rapidly and causing cancer.

Aside from its clinical potential, the scientists say the finding advances the understanding of cancer: It highlights that while MITF normally regulates the development of the skin’s pigment- producing cells, too much MITF spurs these melanocytes to grow malignant.