Project description:Glioblastoma is the most common malignant brain tumor in adults. Cellular plasticity and the poorly differentiated features result in a fast relapse of the tumors following treatment. Moreover, the immunosuppressive microenvironment proved to be a major obstacle to immunotherapeutic approaches. Branched-chain amino acid transaminase 1 (BCAT1) is a metabolic enzyme that converts branched-chain amino acids into branched-chain keto acids, depleting cellular α-ketoglutarate and producing glutamate. BCAT1 was shown to drive the growth of glioblastoma and other cancers; however, its oncogenic mechanism remains poorly understood. Here, we show that BCAT1 is crucial for maintaining the poorly differentiated state of glioblastoma cells and that its low expression correlates with a more differentiated glioblastoma phenotype. Furthermore, orthotopic tumor injection into immunocompetent mice demonstrated that the brain microenvironment is sufficient to induce differentiation of Bcat1-KO tumors in vivo. We link the transition to a differentiated cell state to the increased activity of TET demethylases and the hypomethylation and activation of neuronal differentiation genes. In addition, the knockout of Bcat1 attenuated immunosuppression, allowing for an extensive infiltration of CD8 + cytotoxic T-cells and complete abrogation of tumor growth. Further analysis in immunodeficient mice revealed that both tumor cell differentiation and immunomodulation following BCAT1-KO contribute to the long-term suppression of tumor growth. In summary, our study unveils BCAT1's pivotal role in promoting glioblastoma growth by inhibiting tumor cell differentiation and sustaining an immunosuppressive milieu. These findings offer a novel therapeutic avenue for targeting glioblastoma through the inhibition of BCAT1.
Project description:Genome wide DNA methylation profiling of glioblastoma stem-like-cells was performed to detect changes during long time culturing. The Illumina Infinium MethylationEPIC Kit array was used to obtain DNA methylation profiles across approximately 850,000 CpGs. The samples are seven cell lines containing an early passage (x+0) and an later passage (x+30).
Project description:Genome wide DNA methylation profiling of control and mTORC2-suppressed glioblastoma cells (U87-EGFRvIII cells). The Illumina Infinium HumanMethylation EPIC BeadChip Array was used to obtain DNA methylation profiles with 865,918 probes in glioblastoma cell line samples. Samples included 2 control U87-MG cells without mTORC2 suppresion, and mTORC2-knockdown U87-MG cells with lentivirus-mediated suppression of mTORC2.