03/11/02

MDA Stem Cell Workshop Closes With 'to-do' List

Tucson, Ariz., March 11, 2002 — The Muscular Dystrophy Association's international stem cell workshop closed Saturday with the creation of a short, but demanding 'to-do' list for how to bring stem cells into clinical trials for muscular dystrophy.

MDA Stem Cell Workshop Donald S. Wood (left), MDA's Director of Science Technology, and Louis M. Kunkel, of Children's Hospital of Boston, co-chaired MDA's international stem cell workshop March 8-9.

Stem cells — cells that can morph into a variety of cell types — are best known for their role in fetal development, but they're also found in adult tissues.

About three years ago, scientists discovered that stem cells from adult bone marrow could turn into muscle cells, raising hopes that the cells could be used to repair damaged muscles.

At MDA's first stem cell workshop, held in summer 2000, scientists wrestled with understanding the basic biology of bone marrow stem cells. At last weekend's meeting, many of the same scientists joined neurologists and transplant specialists to move past basic science, and explore the potential use of bone marrow transplants to treat the muscular dystrophies.

Friday's sessions were spent bringing everyone up to speed. The transplant specialists described the successful use of bone marrow transplants for treating leukemia and other disorders of the blood and the immune system (both of which are derived from the bone marrow). MDA-funded scientists described efforts to isolate muscle-forming bone marrow cells from healthy animals and transplant them into animals with Duchenne muscular dystrophy — but, in repeated experiments, only a small fraction of the transplanted cells migrated to muscles and made new muscle tissue.

Before a patient receives a bone marrow transplant, the benefits of the procedure have to be weighed against risks of infection and graft-versus-host disease, in which immune cells in the transplant mount a potentially fatal attack against the recipient's body.

In light of negative results from animal experiments, the benefits of bone marrow transplantation for muscular dystrophy are "completely unknown," transplant specialist William Tse of the Dana Farber Cancer Institute in Boston said at the opening of Saturday's sessions.

"There's potential to do more harm than good," agreed workshop organizer Louis Kunkel of Children's Hospital in Boston, who led the first bone marrow transplant experiments on animals with Duchenne in the late 1990s.

At the close of Saturday's sessions, most of the assembled clinicians and scientists came to a consensus that before bone marrow transplantation can enter clinical trials for muscular dystrophy, it must show therapeutic effects in animals with the disease.

Toward that goal, the group proposed:

  • Collaborating to isolate signals from animal tissue that increase the homing of bone marrow stem cells to muscle.

  • Creating a protocol for taking muscle biopsies from people who've received bone marrow transplants for blood or immune disorders (which could reveal conditions under which bone marrow stem cells home to muscle).

  • Setting up repositories for maintaining and distributing laboratory tools and animals used in muscular dystrophy research.

  • Establishing a computerized database for storing information about the growing number of genetic defects known to cause muscular dystrophy in animals and people.

  • Investigating the use of bone marrow stem cells to treat many versions of muscular dystrophy, including limb-girdle MD and congenital MD.