Nanowire Analysis of Cancer-Testis Antigens as Biomarkers of Aggressive Prostate Cancer

Abstract

To demonstrate the ability of the nCounter Analysis System, a nanowire technology, to sensitively and accurately detect cancer-testis antigens (CTAs) in men with prostate cancer and correlate them with disease parameters. The clinical implementation of novel biomarkers is necessary to provide for individual disease treatment planning for men with prostate cancer. The CTAs, as cancer-associated biomarkers that may correlate with aggressive disease, have the potential to play an important role. Formalin-fixed, paraffin embedded samples were used from men undergoing radical prostatectomy for prostate cancer. The expression of CTAs along with control genes was measured from formalin-fixed, paraffin-embedded prostate cancer tissues using real-time polymerase chain reaction and the nCounter assay. Using a nanowire-based assay, ribonucleic acid (RNA) expression levels of the CTAs CSAG2 and NOL4 were found to be significantly higher in men with Gleason score (GS) 8-10 disease than those with GS≤4+3 disease. On the contrary, the RNA expression level of PAGE4 was lower in men with GS 8-10 disease than those with GS≤6 group. This study demonstrates that CTAs can be detected with a nanostring assay that is translatable and that a set of CTAs correlates with the clinical characteristics of the disease. CTAs represent unique, cancer-associated biomarkers with potential utility in the clinic. The nCounter nanowire technology provides an opportunity to evaluate this panel of CTAs associated with aggressive prostate cancer in a multi-institutional fashion.