SANTA CRUZ, CA--Researchers at the University of California, Santa Cruz, have identified a key molecule for establishing blood stem cells in their niche within the bone marrow. The findings, reported in the January issue of Cell Stem Cell, may lead to improvements in the safety and efficiency of bone marrow transplants.
Bone marrow transplants are a type of stem cell therapy used to treat cancers such as lymphoma and leukemia and other blood-related diseases. In a bone marrow transplant, the "active ingredients" are hematopoietic stem cells, which live in the bone marrow and give rise to all the different kinds of mature blood cells. The new study shows that hematopoietic stem cells use a molecule called Robo4 to anchor themselves in the bone marrow.
"Robo4 is a rare molecule that is found only in hematopoietic stem cells and in the endothelial cells of blood vessels," said Camilla Forsberg, an assistant professor of biomolecular engineering in the Baskin School of Engineering at UC Santa Cruz. After earlier work in her lab showed that Robo4 is specific for hematopoietic stem cells, Forsberg set out to discover how it functions.
The discovery that the cells need Robo4 to stay in the bone marrow has potential therapeutic implications. An increasingly common alternative to traditional bone marrow transplants (which require anesthesia for the bone marrow extraction) involves harvesting hematopoietic stem cells from the blood. Repeated injections of drugs are needed to get the stem cells to leave the bone marrow and enter the bloodstream so that they can be collected with a blood draw. A drug that blocks Robo4 could be a safer and more effective way to do this, Forsberg said.
"If we can get specific and efficient inhibition of Robo4, we might be able to mobilize the hematopoietic stem cells to the blood more efficiently," she said. "We're already working on that in the second phase of the project."
Robo4 acts a
|Contact: Tim Stephens|
University of California - Santa Cruz