Project description:to investigate the sensitization mechanism of temozolomide-resistant U-87 cells by evernic acid, we established gene expression of U-87 cells treated with evernic acid, temozolomide and their combinations compared to the gene expression of untreated cells. The NGS-core facility of the University Hospital Bonn of Bonn University performed the RNA-sequencing.
Project description:The transcription factor, NF-кB, plays a central role in the response to DNA damage. This ubiquitous family of proteins is made up of five subunits: p50 (NF-κB1, p105), p52 (NF-κB2, p100), p65 (relA), relB, and crel that appear in their mature form as dimers. Following stimulation, NF-κB dimers translocate to the nucleus where they bind specific consensus elements (κB-sites) in the promoter region of genes involved in cell survival, inflammation and the immune system. While there is a general propensity of NF-кB to mediate survival, this is not always the case and several reports note the pro-apoptotic nature of the NF-кB pathway. In examining the NF-кB response to DNA damage, we have found that the p50 subunit plays a central role in modulating cytotoxicity following TMZ treatment in malignant glioma. In the current study, given the importance of p50 to the cytotoxic response to TMZ, we set out to identify NF-кB-dependent factors that modulate the response to TMZ. U-87 glioma cells stably transfected with either control-shRNA or p105-shRNA and subsequently treated with temozolomide (TMZ) were selected for RNA extraction and hybridization on Affymetrix microarrays. Each category contains 3 biologic replicates.
Project description:BLM deficient cells responded differently to the temozolomide and olaparib treatment in comparison to the wild type cells. The double treatment evoked cell cycle arrest, cellular senescence or polyploidy in BLM KO LN229 and LN18 cells, respectively.
Project description:Transcriptomic gene expression analysis of LN-229 cells stimulated for 48 h or 144 h with temozolomide is compared to unexposed cells for the characterisation of the glioblastoma senescence phenotype
Project description:A novel application of a non-invasive, electromagnetic field technology has a significant inhibitory effect on the proliferation of glioblastoma multiforme U-87 MG cells in culture. This study reports the cellular and molecular responses of U-87 MG cells to the effects of a tunable, non-ionizing radiation technology that does not induce the serious side effects commonly observed with chemotherapy. The broadband (RF/Low Microwave) electromagnetic field is tuned by means of oscillating wave forms, selected reference materials and a positive feedback loop (RGFIELDS™). By simultaneously targeting specific molecules (oligonucleotides and proteins) that contribute to pathogenesis of glioblastoma with this technology, the continuous exposure of cells for 54 h results in the inhibition of cell growth and a concurrent increase in cell death. We used microarrays to elucidate the cellular processes involved in the response of U-87 MG cells to exposure to RGFIELDS™ and identified mRNA and non-coding RNA sequences that are differentially modulated 1.5 fold or more.
Project description:A critical issue is that recurrent glioblastoma multiforme (GBM) after temozolomide (TMZ) exposure becomes more malignant, exhibiting higher invasion and stemness than the primary tumor. However, the detailed mechanism remains to be elucidated. While the majority of GBM cells succumb to TMZ treatment, some enter cell cycle arrest, adopt a senescence-associated secretory phenotype (SASP), and activate senescence-related signaling pathways. These cells later exit senescence, re-enter the cell cycle, and proliferate, forming aggregates with stemness characteristics, including high expression of stemness markers, colony formation, high invasion, migration, and chemotherapy resistance. Critically, these new aggregates promote the invasion, migration, and chemotherapy resistance of surrounding cells. Gene Set Enrichment Analysis (GSEA) and KEGG analysis of miRNA and mRNA sequences indicated that hallmark-hypoxia and HIF1-signaling pathways were activated. We verified that HIF1α and HIF2α levels changed before, during, and after TMZ treatment. Knocking out HIF1α and HIF2α in GBM cells and exposing them to TMZ resulted in fewer senescent cells and aggregates. This study clarifies how recurrent GBM becomes more malignant during and after TMZ treatment and highlights the regulatory roles of HIF1α and HIF2α, emphasizing that preventing senescence cell formation and inhibiting HIF1α and HIF2α expression are crucial for improving therapeutic outcomes.
Project description:The gene expression profiles were identified in glioblastoma cells treated with FAK inhibitor Y15, temozolomide alone or with combination of Y15 and Temozolomide DBTRG and U87 were treated with FAK inhibitor Y15 at 10 microM for 24 h; U87 cells were treated with Temozolomide 100 microM for 24 h and Y15+temozolomide at the same dose as each agent alone
Project description:A critical issue is that recurrent glioblastoma multiforme (GBM) after temozolomide (TMZ) exposure becomes more malignant, exhibiting higher invasion and stemness than the primary tumor. However, the detailed mechanism remains to be elucidated. While the majority of GBM cells succumb to TMZ treatment, some enter cell cycle arrest, adopt a senescence-associated secretory phenotype (SASP), and activate senescence-related signaling pathways. These cells later exit senescence, re-enter the cell cycle, and proliferate, forming aggregates with stemness characteristics, including high expression of stemness markers, colony formation, high invasion, migration, and chemotherapy resistance. Critically, these new aggregates promote the invasion, migration, and chemotherapy resistance of surrounding cells. Gene Set Enrichment Analysis (GSEA) and KEGG analysis of miRNA and mRNA sequences indicated that hallmark-hypoxia and HIF1-signaling pathways were activated. We verified that HIF1α and HIF2α levels changed before, during, and after TMZ treatment. Knocking out HIF1α and HIF2α in GBM cells and exposing them to TMZ resulted in fewer senescent cells and aggregates. This study clarifies how recurrent GBM becomes more malignant during and after TMZ treatment and highlights the regulatory roles of HIF1α and HIF2α, emphasizing that preventing senescence cell formation and inhibiting HIF1α and HIF2α expression are crucial for improving therapeutic outcomes.
Project description:A critical issue is that recurrent glioblastoma multiforme (GBM) after temozolomide (TMZ) exposure becomes more malignant, exhibiting higher invasion and stemness than the primary tumor. However, the detailed mechanism remains to be elucidated. While the majority of GBM cells succumb to TMZ treatment, some enter cell cycle arrest, adopt a senescence-associated secretory phenotype (SASP), and activate senescence-related signaling pathways. These cells later exit senescence, re-enter the cell cycle, and proliferate, forming aggregates with stemness characteristics, including high expression of stemness markers, colony formation, high invasion, migration, and chemotherapy resistance. Critically, these new aggregates promote the invasion, migration, and chemotherapy resistance of surrounding cells. Gene Set Enrichment Analysis (GSEA) and KEGG analysis of miRNA and mRNA sequences indicated that hallmark-hypoxia and HIF1-signaling pathways were activated. We verified that HIF1α and HIF2α levels changed before, during, and after TMZ treatment. Knocking out HIF1α and HIF2α in GBM cells and exposing them to TMZ resulted in fewer senescent cells and aggregates. This study clarifies how recurrent GBM becomes more malignant during and after TMZ treatment and highlights the regulatory roles of HIF1α and HIF2α, emphasizing that preventing senescence cell formation and inhibiting HIF1α and HIF2α expression are crucial for improving therapeutic outcomes.