Defective homing is associated with altered Cdc42 activity in cells from patients with Fanconi anemia group A.
Previous studies showed that Fanconi anemia (FA) murine stem cells have defective reconstitution after bone marrow (BM) transplantation. The mechanism underlying this defect is not known. Here, we report defective homing of FA patient BM progenitors transplanted into mouse models. Using cells from patients carrying mutations in FA complementation group A (FA-A), we show that when transplanted into nonobese diabetic/severe combined immunodeficiency (NOD/SCID) recipient mice, FA-A BM cells exhibited impaired homing activity. FA-A cells also showed defects in both cell-cell and cell-matrix adhesion. Complementation of FA-A deficiency by reexpression of FANCA readily restored adhesion of FA-A cells. A significant decrease in the activity of the Rho GTPase Cdc42 was found associated with these defective functions in patient-derived cells, and expression of a constitutively active Cdc42 mutant was able to rescue the adhesion defect of FA-A cells. These results provide the first evidence that FA proteins influence human BM progenitor homing and adhesion via the small GTPase Cdc42-regulated signaling pathway.
Division of Experimental Hematology, Cincinnati Children's Research Foundation and Fanconi Anemia Comprehensive Care Center, Cincinnati Children's Hospital Medical Center, OH 45229, USA.
Xiaoling
X
Zhang
Xun
X
Shang
Fukun
F
Guo
Kim
K
Murphy
Michelle
M
Kirby
Patrick
P
Kelly
Lilith
L
Reeves
Franklin O
FO
Smith
David A
DA
Williams
Yi
Y
Zheng
Qishen
Q
Pang
D000293:Adolescent; D000328:Adult; D000818:Animals; D001854:Bone Marrow Cells / Q000378:metabolism* / Q000473:pathology; D016026:Bone Marrow Transplantation; D016022:Case-Control Studies; D002448:Cell Adhesion; D002465:Cell Movement; D002648:Child; D003114:Colony-Forming Units Assay; D005199:Fanconi Anemia / Q000378:metabolism* / Q000473:pathology; D006412:Hematopoietic Stem Cells / Q000378:metabolism / Q000473:pathology; D006801:Humans; D051379:Mice; D016688:Mice, Inbred NOD; D016513:Mice, SCID; D014183:Transplantation, Heterologous; D020764:cdc42 GTP-Binding Protein / Q000378:metabolism*
D020764:cdc42 GTP-Binding Protein