Expression of vascular endothelial growth factor receptor 3 and Tie1 tyrosine kinase receptor on acute leukemia cells

Background. Recent data indicate a role for angiogenesis in hematologic malignancies. In addition to promoting new vessel growth in the bone marrow microenvironment, angiogenic factors are regulators of both hematopoietic and leukemic cells. Activation of vascular endothelial growth factor receptor 3 (VEGFR-3) and Tiel tyrosine kinase receptor are known to promote leukemia cell survival. The details of this complex angiogenesis-related interaction are still uncertain. Procedure. We studied bone marrow samples from 73 patients with acute lymphoblastic (ALL) or myelogenous (AML) leukemia by using immunological methods. Results. Vascular endothelial growth factor receptor 3 expression was found in 15% of the samples, particularly in samples with pediatric lymphoblastic leukemias and monocytic AMLs. Tiel protein expression was found in 11% of the samples, all of which were from adult AML patients. Conclusions. Our findings suggest that there are angiogenesis-related differences between pediatric and adult lymphoblastic leukemias as well as between lymphoid and myeloid leukemias. Pediatr Blood Cancer 2007;48:387-392. (c) 2006 Wiley-Liss, Inc.