FIGURE 6.

Upregulation of ribosomal proteins and a hypothetical scheme of incorporation of ribosomal proteins into glioblastoma multiforme (GBM) cells. A, Heatmap showing RNA expression of 96 ribosomal proteins including ribosomal protein S6 (RPS6) in cellular tumor and GBM stem cell (GSC)‐dominant areas (perinecrotic zone, pseudopalisading cells around necrosis, hyperplastic blood vessels in cellular tumor, microvascular proliferation, leading edge, and infiltrating tumor) from the IVY GAP database. The value in the heat map is the Z‐score. Red indicates RNA upregulation, and green indicates RNA downregulation. B, Scheme showing the concepts of GSC niches and ribosomal proteins. GBM cells were affected by inflammation and stress in perivascular, perinecrotic, and border niches, where GBM cells expressed RPS6 and other ribosomal proteins. GBM cells generate microvesicles containing RNAs and proteins including ribosomal proteins, which function as mediators for intercellular communication. We hypothesized that upregulated intrinsic ribosomal proteins and their incorporation from other GBM cells may promote the induction of stem cell properties in GBM cells and from GSC niches