Cancer’s copper connections
Dozens of human enzymes incorporate or utilize copper, taking advantage of the metal’s readiness to donate or accept electrons to catalyze key bio chemical reactions. Tumors, however, may be especially dependent on the metal. Copper, for example, promotes angiogenesis, the growth of blood vessels that can feed an expanding tumor, and depleting it may keep cancer in check. Copper also binds an enzyme that enables tumor cells to metastasize and is required for signaling by the mutant BRAF protein, which drives half of melanomas and many other cancers. “Maybe what we’ll find is that particular cancer types are more susceptible to particular copper-dependent processes,” says pharmacologist Donita Brady of Duke University in Durham, North Carolina.