Unpacking neurofibromatosis

Unpacking neurofibromatosis

National foundation turns to UF tumor expert

By Doug Bennett

A University of Florida Health researcher who specializes in studying tumors that form on nerve tissue now has a new way to probe deeper into the genetic disorder.

Margaret “Peggy” Wallace, Ph.D., a professor in the UF College of Medicine’s department of molecular genetics and microbiology, is developing cell lines that will help advance neurofibromatosis research. A two-year, $250,000 award from the Children’s Tumor Foundation is funding the work.

Neurofibromatosis has three forms, all of them involving progressive formation of benign Schwann cell tumors throughout life. Schwann cells typically form the protective myelin sheath that covers nerves. Genetic abnormalities cause these cells to form slow-growing tumors on the sheath. The tumors may lead to problems that range from cosmetic to life-threatening. While the tumors are usually benign, they can also kill some patients by becoming malignant or destroying adjacent organs and tissues.

The three forms of neurofibromatosis — neurofibromatosis 1, neurofibromatosis 2, and schwannomatosis — affect more than 2 million people worldwide, according to the Children’s
Tumor Foundation.

“When these cells do go awry, they start growing in and through the nerve fibers, causing everything to enlarge,” Wallace said.

There is no cure for the tumors, but treatment typically involves removing the ones that are causing problems. This treatment is unsatisfactory and poses a dilemma: Removing all of a tumor ruins the attached nerve but leaving part of the tumor behind to preserve nerve function can allow it to grow back.  About 10 to 15 percent of neurofibromatosis 1 tumors become cancerous. Treating neurofibromatosis 2 sometimes means removing auditory nerve tumors, which can lead to deafness. Schwannomatosis can cause severe, debilitating pain and neurological problems. Drug therapies to stop or prevent tumor growth are desperately needed, but that requires more knowledge about these growths.
Research into the trio of disorders has been hindered by a lack of tumor tissues and pure tumor cell lines to study, according to Wallace.

“Without sufficient material to study, we don’t have as many clues about what’s going wrong in these tumors,” she said.

Having tumors from different people is also important in order to learn how they can vary, and to develop a range of therapies specific to different tumor types, Wallace said.

That’s where the foundation’s funding comes into play. The Children’s Tumor Foundation’s financial support is helping Wallace’s lab to receive tumor tissues after a patient’s death and develop cell lines for neurofibromatosis research. Harvesting the tumor tissue is challenging and urgent work: It has to be done quickly using specialized techniques. The cells are then processed immediately in tissue culture. Even then, there’s no guarantee that the cells will live on in the lab.

After the foundation developed a nationwide system for collecting neurofibromatosis samples on short notice, it turned to UF because of Wallace’s experience with culturing neurofibromatosis tumor cells and recent progress in immortalizing cell lines.

The foundation contract, which began in July, has led to several donations from patients with neurofibromatosis 1 and a patient with schwannomatosis. Wallace’s laboratory is using the tumor samples to establish cell cultures. Her lab is now working on developing them into a permanent cell lines for research – something that would be a relatively unique scientific resource. Ultimately, the Children’s Tumor Foundation will make the cell lines available to other researchers. That could help accelerate the pace of advances that lead to treatments for neurofibromatosis tumors, she said.

Not all samples have to be collected after death, and Wallace said those involved in studying the disease are looking for ways to remind patients that they can help by arranging to donate tissue samples before they have surgery on their tumors.

“We just need more chances to get tissue to determine what’s going on with these tumors,” she said.
For Wallace, it’s not just about the scientific success that would come with cracking the genetic code that causes the tumors. She knows a number of people who had neurofibromatosis and eventually died from the disorder.

“I feel a personal commitment to work toward developing effective therapies and fulfilling these legacies as fast as possible for the sake of those who still suffer from these conditions,” she said.