Quantum dot-based immunofluorescent imaging and quantitative detection of DNER and prognostic value in prostate cancer

DNER, Delta/Notch-like epidermal growth factor (EGF)-related receptor, is a neuron-specific transmembrane protein carrying extracellular EGF-like repeats. The prognostic value of DNER in prostate cancer has not been evaluated. Here we showed that the up-regulation of DNER protein was observed in prostate cancer detected by immunohistochemistry (IHC) and quantum dot-based immunofluorescent imaging and quantitative analytical system (QD-IIQAS). However, a higher accuracy of measurements of DNER expression in prostate cancer was found by QD-IIQAS than by IHC (AUC = 0.817 and 0.617, respectively). DNER was significantly higher in patients undergoing bone metastasis (P = 0.045, RR = 3.624). In addition, DNER overexpression was associated with poor overall survival (OS) (P = 0.028, adjusted HR = 8.564) and recurrence-free survival (RFS) (P = 0.042, adjusted HR = 3.474) in patients suffering prostate cancer. Thus, QD-IIQAS is an easy and accurate method for assessing DNER and the DNER expression was an independent prognostic factor in prostate cancer.