Chemotherapeutic Stress Induces Transdifferentiation of Glioblastoma Cells to Endothelial Cells and Promotes Vascular Mimicry

Figure 1

TMZ treatment induces expression of endothelial makers in patient-derived GBMs. A panel of human glioma cell lines (A172 and U251) and patient-derived xenograft cells (GBM43, GBM12, and GBM6) was treated with TMZ (50 μM) or equimolar DMSO (CTRL). After 8 days, cells were analyzed by flow cytometry for the percentage of cells positive for (a) CD133, a maker of glioma stem cells (GSC); (c) CD105 and (e) CD144, markers of intermediate endothelial cells; and (d) CD34 and (e) CD31, markers of mature endothelial cells. To confirm the induction of a GSC population, cells were analyzed for CD133 and CD15. In addition, the population of cells positive for both CD133 and each endothelial marker was analyzed (d, f, h, j). Bars represent the means of three independent experiments, and error bars show the standard error measure. The effect of TMZ was compared in each cell line by the Student -test with Tukey’s post hoc test.

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