Aberrant changes in N-linked glycans on the cell membrane are associated with cancer progression. These alterations drive structural and functional impairments in cell-cell and cell-matrix interactions, thereby increasing the metastatic potential of tumours. In this study, we employ MALDI-TOF mass spectrometry imaging (MALDI-MSI) to spatially profile N-glycans in tumour sections from a xenograft mouse model of metastatic cancer. Our model for this study was immunodeficient non-obese diabetic mice with severe combined immune-deficiency (NOD-SCID). These mice developed primary tumours following subcutaneous xenografting with the human prostate cancer cell line PC-3. Primary tumours subsequently progressed to lung and bone metastases, with formalin-fixed, paraffin-embedded (FFPE) tissue prepared from tumours representing each disease stage. FFPE sections were mounted on indium tin oxide slides for MALDI-MSI sample processing, while consecutive sections were prepared for hematoxylin and eosin (H&E) staining.
N-glycan and matched H&E data were obtained from 12 FFPE samples, categorised as primary tumours, bone metastases, or lung metastases. Histopathological annotation of H&E-stained sections enabled identification of morphologically distinct tissue components, including dense and loose tumour regions, necrotic and para-necrotic areas, subcapsular tissue, and skeletal muscle. High-resolution spatial MSI data were overlaid with matched H&E images to reveal intra- and inter-tumoral N-glycan features. We detect approximately 118 unique compositions, comprising oligomannose, hybrid, and sialylated N-glycans. Both NeuGc and NeuAc residues exhibited unique spatial localisation across distinct tissue regions. We aim to characterise differences in N-glycan profiles within these regions between primary and metastatic samples to further investigate the association between the glycome and cancer progression.