Bone marrow angiogenesis in patients with hematological malignancies : role of VEGF

The formation of new capillaries from pre-existing blood vessels is known as angiogenesis. This process is enhanced by several cytokines including basic fibroblastic growth factor (bFGF), IL-8, vascular endothelial growth factor (VEGF) and others. VEGF appears to be the most relevant cytokine in this respect, since its expression is closely correlated with vessel density in several human tumors and inhibition of VEGF by specific antibodies suppresses tumor growth. The aim of our work was to study BM angiogenesis in a variety of hematopoietic neoplasms and to investigate any possible role for VEGF in the growth of such neoplasms. A total of 80 patients with various hematological neoplasms were evaluated for BM angiogenesis. They were divided into 4 groups including 20 patients with non-Hodgkin's lymphoma and 20 patients with Hodgkin's disease, both with bone marrow infiltration, 20 patients with multiple myeloma and 20 patients with acute leukemia. Sera from patients and controls were collected for estimation of VEGF. Our results showed that both microvessel density in BM biopsies and serum VEGF levels in patients with hematological malignancies significantly exceeded those of the controls. Also, there was a significant positive correlation between the vessel count and VEGF levels in patients with both MM and NHL.