A new finding has led to the development of a new chemical compound that can accelerate this process (called stem cell mobilization) in mice - which could eventually lead to more efficient stem cell harvesting for human use.
The researchers, from the Cincinnati Children's Hospital Medical Center and the University of Cincinnati (UC), studied the migration of mouse stem cells to better understand how adult cells move into the bone marrow during stem cell transplants - or can be directed into the blood stream, where they can be more easily harvested for use in transplant procedures.
The team, led by Jose Cancelas, MD, PhD, and David Williams, MD, found that a group of proteins known as the RAC GTPase family plays a significant role in regulating the location and movement of stem cells in bone marrow.
Dr. Cancelas, lead author of the report, is director of research at UC's Hoxworth Blood Center. Dr. Williams, the senior author, heads experimental hematology at Cincinnati Children's.
The researchers discovered that by inhibiting RAC GTPase activity in mice, they were able to "instruct" stem cells to move from their home in the bone marrow and into the blood stream, where they can easily be collected. They achieved this using a drug, developed by Cincinnati Children's faculty member Yi Zheng, PhD, known as NSC23766.
Their findings are reported in the Aug. 6 edition of the scientific journal Nature Medicine.
Scientists have long known that bone marrow stem cells regenerate blood cells. Recent research has also suggested that these cells may help repair damage in other organs, such as the heart and brain.
Injected during transplants procedures, stem cells migrate to a specific location in the bone marrow, where they reestablish the mechanism of blood formation.
"Our findings demonstrate that RAC GTPase proteins are essential for injected stem cells to migrate into the correct location in the bone marrow," said Dr. Williams.
Researching the location of and the factors involved in stem cell regeneration is important to the development of new therapeutic tools in stem cell therapy, said Dr. Cancelas, lead author of the report.
"We wanted to know why stem cells are located in specific pockets of the bone marrow," he said, "and how can they be mobilized to move into the blood stream for easier collection."