Disrupting the TGF-β-regulated epithelial-mesenchymal transition, apoptotic and autophagic phenotypes of 3D glioblastoma spheroids via glycolytic inhibition.

Aim: Glioblastoma (GBM), a rare, highly aggressive and chemoresistant brain cancer, exhibits profound metabolic plasticity that relies, in part, on aberrant transforming growth factor-β (TGF-β) signaling. Such plasticity was recently associated with TGF-β-regulated apoptosis and autophagy. Here, we questioned whether TGF-β-regulated apoptotic/autophagic phenotypes are recapitulated in a preclinical in vitro 3D spheroid culture model of human U87 GBM-derived cells, and how metabolic alterations affect such phenotypes. Methods: 3D U87 spheroids were cultured using the hanging drop method. Western blotting was used to assess protein expression, while RT-qPCR was used to assess gene expression levels. Results: 3D spheroids exhibited decreased AKT phosphorylation, and increased TGF-β, fibronectin, and Smad2 phosphorylation, indicative of both cell death signaling and epithelial-mesenchymal transition molecular signatures. 2-Deoxy- Conclusions: 3D spheroids require ATP and a TGF-β/TGF-βR1 autocrine signaling axis to recapitulate the apoptosis/autophagy phenotypes. Combining glycolysis inhibition with TGF-β signaling inhibition could offer a promising therapeutic strategy for this rare and lethal brain cancer.