Extracellular matrix proteome remodelling in human glioblastoma and medulloblastoma

Medulloblastomas (MBs) and Glioblastomas (GBMs) are high-incidence central nervous system tumors. Different origin sites and changes in the tissue microenvironment have been associated with onset and progression. Here, we describe differences between the ECM signature of these tumors. We compared the proteomic profiles of MB and GBM decellularized tumor samples among each other and their normal decellularized brain site counterparts. Our analysis reveals that 19 proteins were differentially expressed in MBs, 28 proteins in GBMs, and 11 proteins in both MBs and GBMs. Next, we validated key findings by protein tissue array with 53 MB and 55 GBM cases and evaluated the clinical relevance of the identified differentially expressed proteins through their analysis on publicly available datasets, 763 MB samples from microarray-GSE50161, and 115 GBM samples from RNAseq-TCGA. We report a shift towards a denser fibrillary ECM as well as a clear alteration in the glycoprotein signature, which influences the tumor pathophysiology.