Fig. 5: Alendronate reduces the embryonic stem cell signature and activates necrosis in glioblastoma spheres.

a DEGs between TS13-20 cells treated with or without alendronate (10 μM) for 7 days were analyzed by RNA sequencing. Genes with expression changes greater than two-fold are shown. DEGs are listed in Supplementary Table S3. b GSEA showed that embryonic stem cell gene signatures were downregulated in alendronate-treated cells. c, d DEGs were analyzed by core analysis using Ingenuity® Pathway Analysis (IPA). c Canonical pathway analysis showed that the most functionally influenced mechanistic network was the complement system. d Downstream effect analysis showed that necrosis- and development-related genes were activated by treatment with alendronate in the disease and functions category. A: cell viability of neurons, B: cell viability, C: neuronal cell death, D–F: apoptosis, G: necrosis, H-J: cellular development, K-M: tissue development, N–O: nervous system development and function, P: embryonic development, Q: organismal development, R: connective tissue development and function. e The network of necrosis-related DEGs induced by treatment with alendronate is shown. f Alendronate caused necrosis-related cell death. TS13-20 cells were treated with staurosporine (0.5 μM, 18 h), hydrogen peroxide (1 mM. 18 h), or alendronate (10 μM, 3 days) and then stained with Hoechst and propidium iodide. Z-stack orthogonal projection images were obtained with an LSM780 confocal microscope and processed using ZEN 2012 analysis software (Carl Zeiss, Germany). g A model linking FDPS with glioblastoma stemness. Glioblastoma TS cells rely on FDPS for maintenance of stemness, and alendronate is a potential candidate drug for glioblastoma treatment