Project description:CDK7 has been identified as a potential drug target for glioblastoma (GBM), a highly lethal primary brain tumor. However, resistance to therapy develops quickly, which may be facilitated by drug-induced reprogramming of metabolism. By combination of a transcriptome and metabolite screening analyses followed by carbon tracing (U-13C-Glucose, U-13C-Glutamine and U-13C-Palmitic acid) and extracellular flux analysis, we demonstrated that both genetic and pharmacological (YKL-5-124 and THZ1) CDK7 inhibition elicited substantial metabolic reprogramming. Specifically, CDK7 inhibition elicited an increase of oxygen consumption rate fueled by enhanced fatty acid oxidation (FAO) manifested by enhanced labeling of citric acid cycle intermediates from palmitic acid. Consistently, the combination treatment of CDK7 inhibitors with blockers of FAO (etomoxir) exerted substantial synergistic growth inhibition in patient derived xenograft as well as neurosphere GBM cultures, which was mainly driven by a collapse of oxidative energy metabolism. In turn, exogenous administration of adenosine triphosphate partially rescued from the cell death induced by the combination treatment. Finally, the combined administration of YKL-5-124 and etomoxir extended overall in an orthotopic patient-derived xenograft model of GBM. In summary, these data support that simultaneous targeting of CDK7 and FAO might be a potential novel therapy against GBM.
Project description:GBM neurosphere line GBM1B were depleted of growth factors for 16 hours followed by EGF stimulation for 4 and 24 hours. RNA-seq was used to identify differentially-expressed (DE) genes after EGF treatment.
Project description:Glioblastomas (GBM) may contain a variable proportion of active cancer stem cells (CSCs) capable of self-renewal, of aggregating into CD133+ neurospheres, and to develop intracranial tumors that phenocopy the original ones. We hypothesized that nucleostemin may contribute to cancer stem cell biology as these cells share characteristics with normal stem cells. Here we report that nucleostemin is expressed in GBM-CSCs isolated from patient samples. The significance of its expression was addressed by targeting the corresponding mRNA using lentivirally transduced short hairpin RNA (shRNA). We found that an off-target nucleostemin RNAi (shRNA22) abolishes proliferation and induces apoptosis in GBM-CSCs. Furthermore, in the presence of shRNA22, GBM-CSCs failed to form neurospheres in vitro or grow on soft agar. When these cells are xenotransplanted into the brains of nude rats, tumor development is severely compromised. Attempts were made to identify the primary target of shRNA22, suggesting a transcription factor involved in one of the MAP-kinases signaling-pathways. The use of this shRNA may offer a new therapeutic approach for this incurable type of brain tumors. The transcriptional profile of neurosphere cultures infected with lentiviral particles containing shRNA22 was compared with the profile of neurosphere cultures infected with lentiviral particles containing control shRNA. Experiments were done in triplicate.
Project description:Analysis of genome wide gene expression changes over a time course of 24 hours induced by the Rho kinase inhibitor Fasudil in primary mouse astrocyte cultures.
Project description:Glioblastoma (GBM) remains an incurable disease, requiring more effective therapies. Through CRISPR and RNAi library screening interrogation we identified several TCA-cycle enzymes as essential for GBM growth. By combining a transcriptome and metabolite screening analyses we discovered that loss of function of OGDH by the clinically validated drug compound, CPI-613, is synthetically lethal with Bcl-xL inhibition (genetically and through the clinically validated BH3-mimetic, ABT263) in patient-derived xenograft as well neurosphere GBM cultures. CPI-613 mediated energy deprivation drives an integrated stress response with an up-regulation of the BH3-only domain protein, Noxa in an ATF4 dependent manner as demonstrated by genetic loss of function experiments. Consistently, silencing of Noxa rescued from cell death induced by CPI-613 in model systems of GBM. In patient-derived xenograft models of GBM in mice, the combination treatment of ABT263 and CPI613 suppressed tumor growth more potently than each compound on its own. Therefore, combined inhibition of Bcl-xL along with interference of the TCA-cycle might be a novel treatment strategy for GBM.
Project description:Primary glioblastoma (GBM) cultures vary with respect to differentiation competency. We sought to identify putative transcription factors necessary for the differentiation of GBM cultures. In this dataset, we include expression data obtained from 2 human-fetal neural stem cell (HF-NS) cultures and 2 GBM stem cell (GSC) cultures. We assessed changes in gene expression from 3 timepoints during an in vitro differentiation protocol.
Project description:<h4><strong>BACKGROUND:</strong> Elevated choline kinase alpha (ChoK) is observed in most solid tumours including glioblastomas (GBM), yet until recently, inhibitors of ChoK have demonstrated limited efficacy in GBM models. Given that hypoxia is associated with GBM therapy resistance, we hypothesised that tumour hypoxia could be responsible for such limitations. We therefore evaluated in GBM cells, the effect of hypoxia on the function of JAS239, a potent ChoK inhibitor.</h4><h4><strong>METHODS:</strong> Rodent (F98 and 9L) and human (U-87 MG and U-251 MG) GBM cell lines were subjected to 72 hours of hypoxia conditioning and treated with JAS239 for 24 hours. NMR metabolomic measurements and analyses were performed to evaluate the signalling pathways involved. In addition, cell proliferation, cell cycle progression and cell invasion were measured in cell monolayers and 3D spheroids, with or without JAS239 treatment in normoxic or hypoxic cells to assess how hypoxia affects JAS239 function.</h4><h4><strong>RESULTS:</strong> Hypoxia and JAS239 treatment led to significant changes in the cellular metabolic pathways, specifically the phospholipid and glycolytic pathways associated with a reduction in cell proliferation via induced cell cycle arrest. Interestingly, JAS239 also impaired GBM invasion. However, JAS239 effects were variable depending on the cell line, reflecting the inherent heterogeneity observed in GBMs.</h4><h4><strong>CONCLUSION:</strong> Our findings indicate that JAS239 and hypoxia can deregulate cellular metabolism, inhibit proliferation and alter cell invasion. These results may be useful for the design of new therapeutic strategies based on ChoK inhibition that can act on multiple pro-tumorigenic features.</h4>
Project description:ASCL1 mediates neuronal differentiation of GBM stem cell (GSC) cultures. We sought to identify genomic targets of ASCL1 in primary human GSC cultures. In this dataset, we include ChIP-seq data obtained from GSC cultures harbouring a CRISPR-deletion of ASCL1. We assessed differential ASCL1 binding between control and GSC cultures induced to overexpress ASCL1 after 18 hours of doxycycline treatment.