Significance of neuropilin-1 mRNA expression in chronic myeloid leukemia

Background Neuropilins (NRPs) are transmembrane glycoproteins that act as receptors for vascular endothelial growth factors and are involved in the process of tumor angiogenesis. Patients and methods We analyzed the significance of NRP-1 RNA expression level in 63 newly diagnosed chronic myeloid leukemia (CML) patients and 40 healthy controls using real-time PCR. Results NRP-1 was significantly highly expressed in CML patients than in controls and in patients in the accelerated phase than in those in the chronic phase. Its levels were significantly positively correlated with total leucocytic count (TLC), platelets count, and percentage of blast, whereas it was negatively correlated with progression-free survival. NRP-1 expression level revealed a statistically significant difference as regards response to imatinib therapy: it was significantly higher in those who did not achieve complete molecular response. During the follow-up period, the NRP-1 levels in patients still in remission were significantly lower than those who showed progression to accelerated or blastic phase; the median time of progression-free survival in patients with high NRP-1 was significantly shorter than those who had normal level. Conclusion We conclude that NRP-1 expression is significantly associated with CML and that its level might serve as an indicator for disease severity and progression.