Glioblastoma‐derived extracellular vesicles modify the phenotype of monocytic cells

J de Vrij, SLN Maas, KMC Kwappenberg… - … journal of cancer, 2015 - Wiley Online Library
J de Vrij, SLN Maas, KMC Kwappenberg, R Schnoor, A Kleijn, L Dekker, TM Luider…
International journal of cancer, 2015Wiley Online Library
Glioblastoma multiforme (GBM) is the most common primary brain tumor and is without
exception lethal. GBMs modify the immune system, which contributes to the aggressive
nature of the disease. Particularly, cells of the monocytic lineage, including monocytes,
macrophages and microglia, are affected. We investigated the influence of GBM‐derived
extracellular vesicles (EVs) on the phenotype of monocytic cells. Proteomic profiling showed
GBM EVs to be enriched with proteins functioning in extracellular matrix interaction and …
Glioblastoma multiforme (GBM) is the most common primary brain tumor and is without exception lethal. GBMs modify the immune system, which contributes to the aggressive nature of the disease. Particularly, cells of the monocytic lineage, including monocytes, macrophages and microglia, are affected. We investigated the influence of GBM‐derived extracellular vesicles (EVs) on the phenotype of monocytic cells. Proteomic profiling showed GBM EVs to be enriched with proteins functioning in extracellular matrix interaction and leukocyte migration. GBM EVs appeared to skew the differentiation of peripheral blood‐derived monocytes to alternatively activated/M2‐type macrophages. This was observed for EVs from an established cell line, as well as for EVs from primary cultures of GBM stem‐like cells (GSCs). Unlike EVs of non‐GBM origin, GBM EVs induced modified expression of cell surface proteins, modified cytokine secretion (e.g., an increase in vascular endothelial growth factor and IL‐6) and increased phagocytic capacity of the macrophages. Most pronounced effects were observed upon incubation with EVs from mesenchymal GSCs. GSC EVs also affected primary human microglia, resulting in increased expression of Membrane type 1‐matrix metalloproteinase, a marker for GBM microglia and functioning as tumor‐supportive factor. In conclusion, GBM‐derived EVs can modify cells of the monocytic lineage, which acquire characteristics that resemble the tumor‐supportive phenotypes observed in patients.
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