Bone Marrow Failure |
1 Division of Experimental Hematology, Cincinnati Childrens Hospital Research Foundation, Cincinnati;
2 College of Medicine, University of Cincinnati, Cincinnati and
3 Hoxworth Blood Center, University of Cincinnati, USA
Correspondence: Jose A. Cancelas, Division of Experimental Hematology, Cincinnati Childrens Hospital Med. Center and Research Division, Hoxworth Blood Center, University of Cincinnati Medical Center, Cincinnati, OH, USA. E-mail:jose.cancelas{at}chmcc.org
Fanconi anemia is a severe bone marrow failure syndrome resulting from inactivating mutations of Fanconi anemia pathway genes. Gene and cell therapy trials using hematopoietic stem cells and progenitors have been hampered by poor mobilization of HSC to peripheral blood in response to G-CSF. Using a murine model of Fanconi anemia (Fanca–/– mice), we found that the Fanca deficiency was associated with a profound defect in hematopoietic stem cells and progenitors mobilization in response to G-CSF in absence of bone marrow failure, which correlates with the findings of clinical trials in Fanconi anemia patients. This mobilization defect was overcome by co-administration of the Rac inhibitor NSC23766, suggesting that Rac signaling is implicated in the retention of Fanca–/– hematopoietic stem cells and progenitors in the bone marrow. In view of these data, we propose that targeting Rac signaling may enhance G-CSF-induced HSC mobilization in Fanconi anemia.
Key words: Fanconi anemia, mobilization, Rho GTPase, NSC23766, hematopoietic stem cells.