BCR/ABL-mediated leukemogenesis requires the activity of the small GTP-binding protein Rac
AUTOR(ES)
Skorski, Tomasz
FONTE
The National Academy of Sciences
RESUMO
The phenotype of hematopoietic cells transformed by the BCR/ABL oncoprotein of the Philadelphia chromosome is characterized by growth factor-independent proliferation, reduced susceptibility to apoptosis, and altered adhesion and motility. The mechanisms underlying this phenotype are not fully understood, but there is evidence that some of the properties of BCR/ABL-expressing cells are dependent on the activation of downstream effector molecules such as RAS, PI-3k, and bcl-2. We show here that the small GTP-binding protein Rac is activated by BCR/ABL in a tyrosine kinase-dependent manner. Upon transfection with a vector carrying the dominant-negative N17Rac, BCR/ABL-expressing myeloid precursor 32Dcl3 cells retained the resistance to growth factor deprivation-induced apoptosis but showed a decrease in proliferative potential in the absence of interleukin-3 (IL-3) and markedly reduced invasive properties. Moreover, compared with BCR/ABL-expressing cells, fewer BCR/ABL plus N17Rac double transfectants were capable of homing to bone marrow and spleen. Consistent with these findings, survival of SCID mice injected with the BCR/ABL plus N17Rac double transfectants was markedly prolonged as compared with that of mice injected with BCR/ABL-expressing cells. Together, these data support the important role of a Rac-dependent pathway(s) controlling motility in BCR/ABL-mediated leukemogenesis.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=21730Documentos Relacionados
- Mas Oncogene Signaling and Transformation Require the Small GTP-Binding Protein Rac
- The small GTP-binding protein Rac is a regulator of cell death in plants
- Molecular cloning of Ian4: a BCR/ABL-induced gene that encodes an outer membrane mitochondrial protein with GTP-binding activity
- Abr and Bcr are multifunctional regulators of the Rho GTP-binding protein family.
- The small GTP-binding protein rab4 is associated with early endosomes.