Nogo-B receptor (NgBR) has been shown to be involved in endothelial cell chemotaxis and morphogenesis. However, few studies analyzing its expression in cancer cells have been performed.

We examined NgBR expression in 233 patients with invasive ductal breast carcinoma (IDC) and corresponding non-malignant breast tissues (NMBT) on mRNA (real-time polymerase chain reaction) and protein levels (immunohistochemistry; IHC and western-blot analysis). NgBR expression was found also analyzed in breast cancer cell lines of varying invasiveness.

NgBR expression was increased in IDC compared to NMBT on the mRNA (p=0.0007) and protein level (p=0.018). NgBR expression decreased significantly with IDC malignancy grade and correlated negatively with the Ki-67 antigen expression (r=-0.18; p=0.0005). High NgBR mRNA expression was associated with estrogen receptor negativity (p=0.0023) and the triple-negative phenotype of the tumors (p=0.0129).

NgBR may be involved in IDC development, however, its role in its progression requires further research.