Abstract
Angiogenesis is a crucial process in the progression of multiple myeloma (MM). Vascular endothelial growth factor (VEGF) and hepatocyte growth factor (HGF) are multifunctional cytokines that potently stimulate angiogenesis during tumor neovascularization. VEGF is secreted by MM cells. It induces proliferation of MM cells and stimulates IL-6 expression by microvascular endothelial cells and bone marrow stroma cells, suggesting both autocrine and paracrine functions for VEGF in MM. HGF and the HGF receptor, c-Met, are expressed simultaneously in MM cell lines and in freshly isolated MM cells, suggesting a possible role for HGF in MM cell proliferation. This review focuses on the clinical significance of serum levels of VEGF and HGF in MM.