Neuropilin-1 expression is associated with lymph node metastasis in breast cancer tissues

Purpose: Neuropilin-1 (NRP1) as an isoform-specific receptor for vascular endothelial growth factor and placenta growth factor in endothelial cells has been demonstrated to be expressed in breast cancer cells where it plays functional roles in cell survival, invasion, and migration. We hypothesized that an expression of NRP1 in breast cancer tissues is associated with clinicopathological data of patients and expression of the tumor suppressor miR-206. Patients and methods: We evaluated the expression of NRP1 in 48 invasive ductal carcinomas of the breast and their corresponding adjacent noncancerous tissues (ANCTs) by means of real-time polymerase chain reaction. We also extracted data on miR-206 gene expression from the same cohort of patients to evaluate the correlation between expression levels of miR-206 and NRP1. In addition, we quantified NRP1 protein levels using the enzyme-linked immuno-sorbent assay technique. Results: No significant difference was found in NRP1 expression between tumoral tissues and ANCTs. We also assessed the associations between expression levels of NRP1 and clinicopathological data of patients and found no significant associations between NRP1 transcript levels and any characteristic. However, NRP1 protein concentrations were significantly higher in patients with lymph node involvement compared with those without lymph node involvement. No correlation was found between NRP1 and miR-206 expression levels. Conclusion: NRP1 protein levels might be an indicator of metastasis potential in breast cancer. Future studies are needed to confirm these results in larger cohorts of patients.