Published in the Dec. 15 online edition of the Proceedings of the National Academies of Science, the work upsets current thinking that transplanted stem cells find a habitable niche, settle in for the long haul and begin producing new blood cells. Instead, the newly transplanted cells drift throughout the body, nestling in one of a few homes where their populations subsequently wax and wane until some finally flourish.
Researchers said the procedure used to follow the injected cells' movements could one day help scientists hone their techniques for transplanting bone-marrow stem cells in humans and optimize therapies for cancer and immunodeficiencies. Developing these types of new stem cell-based treatments for cancer is among the primary goals of Stanford's Institute for Cancer/Stem Cell Biology and Medicine.
Yu-An Cao, PhD, a research associate and first author of the paper, said that until now injecting bone-marrow stem cells into a patient was like injecting them into a black box. "We didn't know where those cells were going," he said. Watching the fates of these cells after transplantation had raised more questions than it answered. He said in testing a new protocol, they now can watch to see whether the cells proliferate more quickly or if the patterns of inhabitation are altered.
"We are really curious about what is happening," Cao said. "We want to know why the process is so dynamic with unpredictable fates for the initial stem cell foci. There's no obvious reason for the stem cells to leave what appears
Contact: Mitzi Baker
Stanford University Medical Center