Drugs used to block copper absorption for a rare genetic ondition may find an additional use as a treatment for certain types of cancer, researchers said.
The researchers found that cancers with a mutation in the BRAF gene require copper to promote tumour growth.
These tumours include melanoma, the most dangerous form of skin cancer that kills an estimated 10,000 people in the US a year, according to the National Cancer Institute.
"BRAF-positive cancers like melanoma almost hunger for copper," said Christopher M Counter, professor of Pharmacology & Cancer Biology at Duke University School of Medicine and senior author of the study.
The BRAF gene is involved in regulating cell division and differentiation. When mutated, the gene causes cells to grow out of control.
Using animal models and cells, Counter and colleagues found that when they experimentally inhibited copper uptake by tumours with the BRAF mutation, they could curb tumour growth.
They achieved similar results with drugs used to treat patients with Wilson disease, a genetic disorder in which copper builds up in the tissue, primarily the brain and liver, causing damage.
"Oral drugs used to lower copper levels in Wilson disease could be repurposed to treat BRAF-driven cancers like melanoma, or perhaps even others like thyroid or lung cancer," said Donita C Brady, lead author of the study.
A clinical trial has already been approved at Duke to test the copper-reducing drugs in patients with melanoma.
The study was published in the journal Nature.