Study Discovers Gene Responsible For Rare Brain Tumor

In a breakthrough finding, researchers have discovered a key gene that is responsible for causing a type of rare brain tumor that has devastating impact on life.

The mutated gene 'BRAF' was discovered by a team of scientists from Dana-Dana-Farber/Boston Children's Cancer and Blood Disorders Center, Massachusetts General Hospital, and the Broad Institute of MIT and Harvard.

During the study, the researchers noticed the presence of BRAF in all samples of tumors called papillary craniopharyngiomas.

Occurring mainly in adults, papillary craniopharyngiomas develop in the base of the brain, near the pituitary gland, hypothalamus and optic nerves. Less than 100,000 people fall victim to this type of tumor. The tumor that affects kids is called adamantinomatous and no clinical drugs are available to treat this.

Carniopharyngiomas are slow growing tumosr. Even though they don't metastasize they trigger severe complications that include headache, visual impairment, hormonal imbalance, short height and obesity. Removing the tumor completely without affecting other structures is very difficult. In most cases the tumors recur.

"From a clinical perspective, identifying the BRAF mutation in the papillary tumors is really wonderful, because we have drugs that get into the brain and inhibit this pathway," said Sandro Santagata, MD, PhD, a co-senior author of the paper. "Previously, there were no medical treatments-only surgery and radiation-and now we may be able to go from this discovery right to a well-established drug therapy."

On analyzing the whole-exome DNA sequencing of 15 craniopharyngiomas, the investigators noticed that a single mutated BRAF gene alone caused 95 percent of the tumors. 

"We were really surprised to find that something as simple as a BRAF mutation by itself, rather than multiple mutations, is what drives these tumors," Santagata concluded.

'BRAF' can currently be treated only with repeated surgeries and radiation. But researchers hope that certain targeted drugs that are already in use to cure other types of tumors can help treat this rare tumor.

Currently, BRAF inhibitors are used to treat mutated malignant melanoma. The team plans on designing a clinical trial to investigate the effectiveness of a BRAF inhibitor in those suffering from papillary carniopharyngiomas.