Transforming growth factor β (TGFβ) and BMP7 regulate glioblastoma stem cells differentiation status

Glioblastoma stem cells (GSCs) fate is controlled by environmental cues, among which cytokines play a crucial role. The transforming growth factor β (TGFβ) family signaling pathways controls GSCs. On one hand, TGFβ promotes cell proliferation in GBM, it induces the expression of platelet-derived growth factor-B (PDGFB). Moreover, TGFβ, via its signaling mediators Smad2/3, induces the expression of the cytokine leukemia inhibitory factor (LIF) and Sox4, which in turn enhances the expression of the stem cell transcription factor Sox2; this increases the self-renewal capacity of the GSCs and their stemness characteristics, and enhances the GSC tumor-initiating potential. On the other hand, Bone morphogenic proteins (BMPs) are known to promote GSC differentiation towards the astrocytic phenotype. To further understand which genes are regulated by TGFβ and BMP7 in GSCs we performed a microarray in the Affymetrix HTA2 platform in three different glioblastoma cell line, U2987, and two patient-derived glioblastoma stem cells, U3031MG and U3034MG, in the presence or absence of 5 ng/ml of TGFβ or 30 ng/ml BMP7 for 24 h, three biological replicates per condition.