Mass Spectrometry Imaging of N-Glycans Reveals Racial Discrepancies in Low Grade Prostate Tumors

Prostate cancer is the most common cancer in men worldwide. Despite its prevalence, there is a critical knowledge gap regarding the underlining molecular events that result in higher incidence and mortality rate in Black men. Identifying molecular features that separate racial disparities is a critical step in prostate cancer research that could lead to predictive biomarkers and personalized therapy. N-linked glycosylation is a co-translational event during protein folding that modulates a myriad of cellular processes. Recently, aberrant N-linked glycosylation has been reported in prostate cancers. However, the full clinical implications of dysregulated glycosylation in prostate cancer has yet to be explored. Herein, we performed high-throughput matrix-assisted laser desorption ionization mass spectrometry analysis to characterize the N-glycan profile from tissue microarrays of over 100 patient tumors with over 10 years of follow up data. We identified several species of N-glycans that were profoundly different between low grade prostate tumors resected from White and Black patients. Further, these glycans predict opposing overall survival between White and Black patients with prostate cancer. These data suggest differential N-linked glycosylation underline the racial disparity of prostate cancer prognosis. Our study highlights the potential applications of MALDI-MSI for digital pathology and biomarker to study racial disparity of prostate cancer patients. Graphical Abstract