Effect of demeclocycline on brain tumor initiating cells
Ontology highlight
ABSTRACT: We have determined that demeclocycline reduces the growth of brain tumor initiating cells (BTICs). Specifically, we sought to obtain insights into the mechanisms by which demeclocycline directly regulates BTIC growth. Analysis of the array data identified several genes that were altered with demeclocycline treatment that could regulate BTIC growth. The study provides the mechanistic basis for the regulation of BTIC growth with demeclocycline treatment.
Project description:We have determined that demeclocycline reduces the growth of brain tumor initiating cells (BTICs). Specifically, we sought to obtain insights into the mechanisms by which demeclocycline directly regulates BTIC growth. Analysis of the array data identified several genes that were altered with demeclocycline treatment that could regulate BTIC growth. The study provides the mechanistic basis for the regulation of BTIC growth with demeclocycline treatment. We subjected 3 BTIC lines to microarray analyses to identify genes involved in the regulation of BTIC growth by demeclocycline. Three BTIC lines (BT012, BT025 and BT048) were treated with 10 µM demeclocycline for 6h. One (1) control and 1 treatment (demeclocycline treated) sample was generated from each BTIC line. Thus, a total of 6 RNA samples from 3 BTIC lines were obtained for microarray analysis.
Project description:We have determined that tenascin C (TNC) regulates the growth of human brain tumor initiating cells (BTICs). We have identified novel mechanisms by which TNC regulates BTIC growth. Analysis of the array data identified a number of genes that were altered with TNC treatment that could potentially regulate BTIC growth. The study provides the mechanistic basis for the regulation of BTIC growth with TNC.
Project description:We have found that innate immune cells (monocytes/macrophages) are compromised in malignant glioma, and we have determined that vitamin B3 (niacin) reactivates and/or reprograms monocytes/macrophages to inhibit glioma growth, particularly by suppressing the growth of brain tumor initiating cells (BTICs). To this end, we sought to obtain insights into the mechanisms by which niacin regulates monocyte/macrophage activity to alter glioma growth. Analysis of the microarray data identified several genes that were differentially altered in niacin-treated monocytes that could regulate BTIC growth. The study has identified a mechanistic basis for the regulation of glioma growth with niacin treatment.
Project description:Glioblastomas coopt stem cell regulatory pathways to maintain brain tumor initiating cells (BTICs), also known as cancer stem cells. Notch signaling has been a molecular target in BTICs, but Notch antagonists have demonstrated limited efficacy in clinical trials. RBPJ is considered a central transcriptional mediator of Notch activity. Here, we report that pharmacologic Notch inhibitors were less effective than targeting RBPJ in suppressing tumor growth. While Notch inhibitors decreased canonical Notch gene expression, RBPJ regulated a distinct profile of genes critical to BTIC stemness and cell cycle progression. RBPJ was preferentially expressed by BTICs and required for BTIC self-renewal and tumor growth. MYC, a key BTIC regulator, bound the RBPJ promoter and treatment with a BET family bromodomain inhibitor decreased MYC and RBPJ expression. Proteomic studies demonstrated that RBPJ binds CDK9, a component of P-TEFb (positive transcription elongation factor), to target gene promoters, enhancing transcriptional elongation. Collectively, RBPJ links MYC and transcriptional control through CDK9, providing potential nodes of fragility for therapeutic intervention, potentially distinct from Notch.
Project description:Determination of the mechanism by which microglia regulate growth of brain tumor initiating cells (BTICs) and differentiation. Results identify the factors involved in the regulation and provide mechanistic basis. We subjected brain tumor initiating cells to microarray to determine the genes involved in BTICs growth and differentiation when exposed to microglia conditioned medium (MCM) for 6h. BTICs were grown in MCM or control medium for 6h, and media was removed and then the cells were subjected for RNA extraction and hybridization on Affymatrix microarrays. Three (3) control and four (4) MCM samples were generated. The overall objective was to collect the RNA from the MCM exposed differentiated BTICs.
Project description:Determination of the mechanism by which microglia regulate growth of brain tumor initiating cells (BTICs) and differentiation. Results identify the factors involved in the regulation and provide mechanistic basis. We subjected brain tumor initiating cells to microarray to determine the genes involved in BTICs growth and differentiation when exposed to microglia conditioned medium (MCM) for 6h.
Project description:Transcriptome analysis on ING5-knockdown brain tumor stem cell lines Stem cell-like brain tumor initiating cells (BTICs) cause recurrence of glioblastomas, with BTIC "stemness" affected by epigenetic mechanisms. The ING family of epigenetic regulators (ING1-5) function by targeting histone acetyltransferase (HAT) or histone deacetylase (HDAC) complexes to the H3K4me3 mark to alter histone acetylation and subsequently, gene expression. Here we find that ectopic expression of ING5, the targeting subunit of HBO1, MOZ and MORF HAT complexes increases expression of the Oct4, Olig2 and Nestin stem cell markers, promotes self-renewal, prevents lineage differentiation and increases stem cell pools in BTIC populations. This activity requires the plant homeodomain region of ING5 that interacts specifically with the H3K4me3 mark. ING5 also enhances PI3K/AKT and MEK/ERK activity to sustain self-renewal of BTICs over serial passage of stem cell-like spheres. ING5 exerts these effects by activating transcription of calcium channel and follicle stimulating hormone (FSH) pathway genes. In silico analyses of The Cancer Genome Atlas (TCGA) data suggest that ING5 is a positive regulator of BTIC stemness, whose expression negatively correlates with patient prognosis, especially in the Proneural and Classical subtypes, and in tumors with low SOX2 expression. These data suggest that altering histone acetylation status and signaling pathways induced by ING5 may provide useful clinical strategies to target tumor resistance and recurrence in glioblastoma.
Project description:we found that a proportion of human and murine brain tumor-initiating cells (BTICs) expressed programmed cell death protein (PD-1) in situ and in culture. PD-1 signaling through NF B promotes BTIC proliferation.
Project description:Brain tumor initiating cells (BTICs), also known as cancer stem cells, hijack high-affinity glucose uptake normally active in brain to maintain energy demands in dynamic tumor microenvironments. Using unbiased metabolomics and genomic analyses, we discovered that de novo purine synthesis is functionally upregulated in BTICs, mediating glucose-sustained anabolic metabolism. Inhibiting purine synthesis abrogated BTIC growth, self-renewal, and in vivo tumor formation by depleting intracellular pools of purine nucleotides, supporting purine synthesis as potential therapeutic point of fragility. In contrast, differentiated brain tumor cells retained proliferative potential with targeting of purine biosynthetic enzymes, suggesting a selective dependence in BTICs. Upstream transcriptional activation of purine synthesis is mediated by MYC. Elevated expression of purine synthetic enzymes correlates with poor prognosis in glioblastoma patients. Collectively, our results suggest that a stem-like state in brain cancer is associated with metabolic reprogramming to fuel tumor hierarchy, revealing potential BTIC cancer dependencies amenable to targeted therapy.
Project description:High-grade gliomas are amongst the most deadly human tumors. Treatment results are overall disappointing. Nevertheless, in several trials around 20% of patients respond to therapy. Diagnostic strategies to identify those patients that will ultimately profit from a specific targeted therapy are urgently needed. Gene expression profiling of untreated tumors is a well established approach for identifying biomarkers or diagnostic signatures. However, reliable signatures predicting treatment response in gliomas do not exist. Here we suggest a novel strategy for developing diagnostic signatures. We postulate that predictive gene expression patterns emerge only after tumor cells have been treated with the agent in vitro. Moreover, we postulate that enriching specimens for tumor initiating cells sharpens predictive expression patterns. Here, we report on the prediction of treatment response of cancer cells in vitro. As a proof of principle we analyzed gene expression in 18 short-term serum-free cultures of high-grade gliomas enhanced for brain tumor initiating cells (BTIC) before and after in vitro treatment with the tyrosine kinase inhibitor Sunitinib. Profiles from treated but not from untreated glioma cells allowed to predict therapy-induced impairment of proliferation of glioma cells in vitro. Prediction can be achieved with as little as 6 genes allowing for a straightforward translation into the clinic once the predictive power of the signature is shown also in vivo. Our strategy of using expression profiles from in vitro treated BTIC-enriched cultures opens new ways for trial design for patients with malignant gliomas. 72 samples; 18 brain tumor initiating cells (BTICs); 4 treatment conditions: 1 µM Sunitinib or 0.00025% DMSO with and without the combination of recombinant growth factors VEGF and PDGF-AB for 6 hours