CCCTC-binding factor is essential to the maintenance and quiescence of hematopoietic stem cells in mice

A DNA-binding protein involved in chromosome architecture is essential for maintaining blood-forming stem cells in the bone marrow. Hyoung-Pyo Kim and colleagues from the Yonsei University College of Medicine in Seoul, South Korea, studied genetically engineered mice in which they ould block the expression of the gene encoding CCCTC-binding factor (CTCF) through the injection of a particular drug. In this way, they showed that CTCF, which aids in chromosome organization and folding, is needed for proper bone marrow function. In the absence of CTCF, blood-forming stem cells in the marrow die off in a process that involves the release of damaging free radical molecules. The findings suggest that modulating CTCF levels may aid in therapies that involve these stem cells, such as bone-marrow transplants or anti-leukemia treatments.