Correlation of neuropilin-1 overexpression to survival in acute myeloid leukemia.

Neuropilin-1 (NRP-1), a vascular endothelial growth factors and semaphorin receptor functioning as mediator of angiogenesis and neuronal guidance, is expressed by various solid tumors. The importance of NRP-1 in hematological malignancies such as acute myeloid leukemia (AML) remains to be elucidated. Therefore, we determined NRP-1 expression by immunohistochemical analysis of bone marrow biopsies of patients with newly diagnosed, untreated AML. The expression of NRP-1 was significantly increased in AML patients (n = 76; median 12.9 arbitrary units (a.u.)) as compared with controls (n = 38; median 2.75 a.u.). Survival was significantly poorer in patients with high (> median) versus low (< or = median) NRP-1 expression levels with 5-year overall survival rates of 16.9 versus 49.6% (P = 0.050). In conclusion, our data provide evidence of increased NRP-1 expression in AML with significant correlation to survival. Thus, NRP-1 might constitute a promising target for antileukemic and antiangiogenic treatment strategies in AML.