Neuropilin1, a novel independent prognostic factor and therapeutic target in triple-negative breast cancer.

Triple-negative breast cancer (TNBC) is the most aggressive breast cancer, and thus, has limited treatment options. Neuropilin1 (NRP1) is a multi-functional transmembrane protein that interacts with a number of signaling receptors and plays an important role in cancer progression. Previous studies demonstrated that the expression of NRP1 is activated and promotes the progression of breast cancer particularly in TNBC compared to other molecular subtypes; however, whether or not the level of NRP1 expression is related to the progression of TNBC warrants further study. In the current study, we determined the expression and function of NRP1 and evaluated the clinical significance of NRP1 in patients with TNBC. In addition, we determined whether or not an NRP1 antagonist potentiates the inhibitory effects of paclitaxel (PTX) in patients with TNBC. In our clinical study, NRP1 had higher expression in TNBC tissues than non-TNBC tissues at the same stage, and NRP1 was an independent prognostic factor. Specifically, the high expression of NRP1 was associated with shorter survival in TNBC patients. In addition, TNBC cells treated with NRP1 antagonist significantly potentiated the effect of PTX on cell proliferation, cell migration, and apoptosis. Our findings suggest that NRP1 expression can act as an independent prognostic factor for TNBC patients, and the combination of PTX and an NRP1 antagonist may be an effective treatment regimen for TNBC.