U. Cincinnati researchers discover efficient stem cell harvesting technique

CINCINNATI—University of Cin-cinnati scientists have discovered how blood-regenerating stem cells move from bone marrow into the blood stream. This finding, in turn, has led to the development of a new chemical compound that can accelerate the process of stem cell mobilization in mice—a technique that could eventually lead to more efficient stem cell harvesting for human use and potential therapeutics.

The findings, which appeared in the Aug. 6 issue of Nature Medicine, are also interesting because they involve the harvesting of adult stem cells rather than the use of embryonic stems cells, thus sidestepping controversial issues surrounding stem cell research.

The University of Cincinnati team, led by Dr. Jose Cancelas and Dr. David Williams, 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.

They found 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 be collected more easily. They achieved this by using a drug known as NSC23766, which was developed by Dr. Yi Zheng, a faculty member at Cincinnati Children's Hospital Medical Center, where Williams heads up the experimental hematology program.

While scientists already knew bone marrow stem cells could regenerate blood cells, recent research has also suggested that such cells can aid in repairing damage in other organs, such as the heart and brain, the university reports. Researching the location of stem cells and the factors involved in stem cell regeneration are important to the development of new therapeutic tools in stem cell therapy, says Cancelas.

Moving from the mouse model to the human model could take a while, though, and there are no specific target dates or milestones for human applications. Even so, at least two pharmaceutical companies have expressed interest in bringing to market a drug that would aid in adult stem cell collection, Cancelas reports.