A new study has found that a large percentage of melanomas and certain other types of cancer - including some leukemias and thyroid cancers - are spurred by a mutation in the BRAF gene that relies on a supply of copper. The researchers suggest these cancers might respond to drugs that are already used to block copper absorption in a rare genetic condition.
Christopher M. Counter, professor of Pharmacology and Cancer Biology at Duke University School of Medicine, in Durham, NC, and colleagues write about their findings in Nature.
At least half of melanomas are caused by mutations in the BRAF gene, which normally helps to regulate cell division and differentiation. When mutated, it causes cells to grow out of control.
In their background information, the researchers explain how they already knew that a typical mutation of the BRAF gene activates a chain of events that triggers a cancer-causing pathway called MAPK (short for mitogen-activated protein kinase).
Targeting some of the enzymes that trigger this pathway, together with a drug that inhibits the BRAF mutation, is already showing promise as a treatment for advanced melanoma, they note.
In previous work, the team had already found that copper boosts the effectiveness of one of the enzymes that trigger the pathway that causes BRAF-positive cancers.
Prof. Counter says that "BRAF-positive cancers like melanoma almost hunger for copper."
Starving the pathway of copper reduced tumor growth in mice and human cells
The researchers found if they starved the pathway of copper, it decreased BRAF mutation signals and reduced tumor growth in mice and human cells.
In this new study, the reearchers found if they starved the pathway of copper, it decreased the signals sent out by the BRAF mutation and reduced tumor growth in mice and human cells.
They found the same result with drugs used to treat people with Wilson disease - a rare genetic condition where copper builds up in tissues of the brain, liver, and other parts of the body and causes damage.
They suggest the drugs - which are taken orally - could be redesigned to treat BRAF-positive cancers like melanoma, and perhaps even lung and thyroid cancers.
Duke has already got the go-ahead to proceed with a clinical trial to test copper-reducing drugs in patients with melanoma.
Prof. Counter says, "This is a great example of how basic research moves from the laboratory to the clinic."
Funds from the National Institutes of Health, the Lymphoma Foundation and donations made in the name of Linda Woolfenden, plus other sources, helped to finance the study.
In October 2013, Medical News Today learned how researchers found a new biomarker for melanoma that could help predict whether patients with melanoma harboring mutations in the BRAF gene are likely to respond to treatments that target them.
Written by Catharine Paddock PhD