Heavy Metal in Melanoma

Several lines of evidence have suggested that matrix metalloproteinases (MMPs) play a role in cancer formation. For instance, mice deficient in the MMP8 protein appear to develop tumors more readily than other mice. The MMP gene family is large. To determine whether these genes are altered in melanoma, investigators performed a mutational analysis in 32 patients with melanoma.

The researchers identified somatic mutations in 23% of the melanoma tumors. Five mutations in one of the most commonly mutated genes, MMP8, reduced MMP enzyme activity. Expression of wild-type or mutant MMP8 did not affect the growth rate of immortalized melanocytes in tissue culture. However, expression of normal MMP8 substantially inhibited two features of cancer cel…