Cell That Can Grow Replacement Tissue Isolated by Researchers
Researchers have isolated from adult bone marrow a master cell that can be directed to grow bone or cartilage, a laboratory feat that experts call a major step toward learning to make replacement parts for ailing or aged bodies.
The researchers at Osiris Therapeutics in Baltimore report in the journal Science that they isolated a single cell, called a mesenchymal stem cell, and then grew it into a colony of more than a million cells that could be induced to produce bone, cartilage or fat.
Other experts in the rapidly expanding field of stem cell research applauded the achievement.
“The fact that they can [isolate] a precursor cell like that and direct it to produce specific cell types is quite an advance,” said Dr. James A. Thomson of the University of Wisconsin, a noted pioneer in stem cell research. “It may be that such cells can eventually be used for therapy, and that would be quite exciting.”
Stem cells are the body’s building blocks. Some, such as pluripotent stem cells, come only from embryos, and many people oppose their use in research.
Other stem cells, such as the mesenchymal cells used by Osiris, are produced in adults.
But only the pluripotent stem cells from embryos are thought to be capable of growing into any tissue in the body. The mesenchymal stem cells are the parent lines for bone, cartilage, fat, tendon and muscle.
The Osiris work helps move stem cell research from the laboratory toward the clinic, said Dr. David J. Anderson, a Howard Hughes Medical Institute stem cell researcher at Caltech.
It’s very likely that researchers will eventually be able to inject specific types of cells into patients, which then would grow into replacement bone, tendon or muscle, said Dr. Mark F. Pittenger, who led the Osiris research.
Laboratory research on animals is already underway, and human studies may be possible in three years, he said.
If the technique proves successful, researchers predict, precursor cells for bone could be used to replace tissue lost to cancer, osteoporosis, injury or dental disease.
Research in rabbits and dogs already has shown that gaps in leg bone caused by surgery, such as for cancer, can be filled in with tissue grown in the body from stem cells.
