Autonomous rhythmic activity in glioma networks drives brain tumor growth
Ontology highlight
ABSTRACT: Glioblastoma cell networks harbor a plastic population of highly active glioblastoma cells that display rhythmic Ca2+ oscillations and are particularly connected to others. Targeting the autonomous rhythmic activity of periodic tumor cells by pharmacological interference with the potassium channel KCa3.1 strongly compromised global network communication. This led to a marked reduction of tumor cell viability within the entire network, reduced tumor growth in mice, and prolonged animal survival. The dependency of glioblastoma networks on periodic Ca2+ activity generates a vulnerability that can be exploited for the development of novel therapies, with KCa3.1 inhibiting drugs as one example. To investigate the molecular mechanism of KCa3.1 blockade, we exposed glioblastoma cells to Senicapoc, a selective inhinitor of the KCa3.1 channel, and performed gene expression profiling analysis using data obtained from RNA-Seq.
Project description:Purpose: Many mammalian genes exhibit circadian expression patterns concordant with periodic binding of transcription factors, chromatin modifications and chromosomal interactions. We determined whether lamina-associated domains (LADs) display oscillatory circadian patterns of interaction with nuclear lamin B1 during hte circadian cycle, and identified any relationship to changes in gene expression patterns in oscillatory LADs or in their vinicity. Methods: To this end, we mapped LADs by chromatin immunoprecipitation-sequencing (ChIP-seq) of lamin B1 (LMNB1) (antibody ab16048, Abcam) from mouse livers colected every 6 h, for 30 h, after entrainment of the circadian clock by 24-h fasting and refeeding. Gene expression profiles were also analyzed by RNA-sequencing (RNA-seq) at the same time points. Results and Conclusions: We report periodic interactions of chromatin domains with nuclear lamin B1, suggesting rhythmic associations of fractions of the genome with the nuclear lamina. Entrainment of the circadian clock by fasting and refeeding is accompanied in mouse liver by a gain of lamin-chromatin interactions followed by oscillations in these interactions at hundreds of lamina-associated domains (LADs). A subset of these oscillations exhibit periodicity and affect one or both LAD borders or entire stand-alone LADs. Periodic LADs are however not a dominant feature of these variable LADs, as most LADs are conserved during the circadian cycle. LAD oscillations are for the most part asynchronous between the 5’ and 3’ ends of LADs. Periodic LADs also uncoupled from gene expression patterns, periodic or not, within or in vicinity of these LADs. Accordingly, periodic genes, including central clock-control genes, are located megabases away from LADs, suggesting their residence in a transcriptionally permissive environment throughout the circadian cycle. Our data suggest autonomous oscillatory associations of fractions of the genome with the nuclear lamina, providing new evidence for rhythmic spatial configurations of chromatin. However, our data also argue that periodic LADs constitute a minor fraction of variable LADs, and reflect stochasticity in variable lamin-chromatin interactions during the circadian cycle.
Project description:Genome-wide rhythmic modulation of RNAPII occupancy and histone acetylation modifications are highly coordinated with rhythmic gene expression, and dynamically modulates diurnal 3D genome architecture remodeling. The rhythmic genes at AM circadian phase and target genes of transcription factors (TFs) are enriched within limited spatial clusters, which forming subnuclear organization hubs to coordinate looping gene expression. Core circadian clock genes related chromatin connectivity networks suggested they co-localized within the same ?transcriptional factory? and define a distinct nuclear landscape and circadian outputs in the AM and PM. Our findings uncover novel diurnal fundamental genome folding principles in plants, and reveal a distinct higher-order chromosome organization that is crucial for coordinating diurnal dynamics of transcriptional regulation.
Project description:Genome-wide rhythmic modulation of RNAPII occupancy and histone acetylation modifications are highly coordinated with rhythmic gene expression, and dynamically modulates diurnal 3D genome architecture remodeling. The rhythmic genes at AM circadian phase and target genes of transcription factors (TFs) are enriched within limited spatial clusters, which forming subnuclear organization hubs to coordinate looping gene expression. Core circadian clock genes related chromatin connectivity networks suggested they co-localized within the same “transcriptional factory” and define a distinct nuclear landscape and circadian outputs in the AM and PM. Our findings uncover novel diurnal fundamental genome folding principles in plants, and reveal a distinct higher-order chromosome organization that is crucial for coordinating diurnal dynamics of transcriptional regulation.
Project description:Genome-wide rhythmic modulation of RNAPII occupancy and histone acetylation modifications are highly coordinated with rhythmic gene expression, and dynamically modulates diurnal 3D genome architecture remodeling. The rhythmic genes at AM circadian phase and target genes of transcription factors (TFs) are enriched within limited spatial clusters, which forming subnuclear organization hubs to coordinate looping gene expression. Core circadian clock genes related chromatin connectivity networks suggested they co-localized within the same ?transcriptional factory? and define a distinct nuclear landscape and circadian outputs in the AM and PM. Our findings uncover novel diurnal fundamental genome folding principles in plants, and reveal a distinct higher-order chromosome organization that is crucial for coordinating diurnal dynamics of transcriptional regulation.
Project description:Genome-wide rhythmic occupancy of RNA polymerase II (RNAPII) is highly coordinated with rhythmic genes expression. Rhythmic RNAPII binding dynamically modulates diurnal 3D genome architecture remodeling with 91% of the chromatin interactions were altered. The rhythmic genes cluster at the 8:00 (AM) circadian phase form spatial interacting clusters in turn assist coordinated rhythmic gene expression, while non-rhythmic genes tend to tether together and contribute to expression at 20:00 (PM) circadian window. Target genes and associated cis-binding motifs of transcription factors enrichment points to the existence of subnuclear organization hub enriched around the TFs. RNAPII-associated chromatin interaction domains (CIDs) are under circadian control, and static CIDs with common node genes but changed connecting genes along the circadian cycle, reveal they may function as distinct clock components in the interconnected circuits between morning and evening. Core circadian clock genes related chromatin connectivity networks reveal a compact and highly connected chromatin architecture serving to coordinate gene expression in the morning, whereas a scattered, loose chromatin architecture coordinates PM gene expression. Our findings uncover novel diurnal fundamental genome folding principles in plants, and reveal the distinct higher-order chromosome organization that is crucial for coordinating diurnal dynamics of transcriptional regulation.
Project description:Genome-wide rhythmic occupancy of RNA polymerase II (RNAPII) is highly coordinated with rhythmic genes expression. Rhythmic RNAPII binding dynamically modulates diurnal 3D genome architecture remodeling with 91% of the chromatin interactions were altered. The rhythmic genes cluster at the 8:00 (AM) circadian phase form spatial interacting clusters in turn assist coordinated rhythmic gene expression, while non-rhythmic genes tend to tether together and contribute to expression at 20:00 (PM) circadian window. Target genes and associated cis-binding motifs of transcription factors enrichment points to the existence of subnuclear organization hub enriched around the TFs. RNAPII-associated chromatin interaction domains (CIDs) are under circadian control, and static CIDs with common node genes but changed connecting genes along the circadian cycle, reveal they may function as distinct clock components in the interconnected circuits between morning and evening. Core circadian clock genes related chromatin connectivity networks reveal a compact and highly connected chromatin architecture serving to coordinate gene expression in the morning, whereas a scattered, loose chromatin architecture coordinates PM gene expression. Our findings uncover novel diurnal fundamental genome folding principles in plants, and reveal the distinct higher-order chromosome organization that is crucial for coordinating diurnal dynamics of transcriptional regulation.
Project description:Genome-wide rhythmic occupancy of RNA polymerase II (RNAPII) is highly coordinated with rhythmic genes expression. Rhythmic RNAPII binding dynamically modulates diurnal 3D genome architecture remodeling with 91% of the chromatin interactions were altered. The rhythmic genes cluster at the 8:00 (AM) circadian phase form spatial interacting clusters in turn assist coordinated rhythmic gene expression, while non-rhythmic genes tend to tether together and contribute to expression at 20:00 (PM) circadian window. Target genes and associated cis-binding motifs of transcription factors enrichment points to the existence of subnuclear organization hub enriched around the TFs. RNAPII-associated chromatin interaction domains (CIDs) are under circadian control, and static CIDs with common node genes but changed connecting genes along the circadian cycle, reveal they may function as distinct clock components in the interconnected circuits between morning and evening. Core circadian clock genes related chromatin connectivity networks reveal a compact and highly connected chromatin architecture serving to coordinate gene expression in the morning, whereas a scattered, loose chromatin architecture coordinates PM gene expression. Our findings uncover novel diurnal fundamental genome folding principles in plants, and reveal the distinct higher-order chromosome organization that is crucial for coordinating diurnal dynamics of transcriptional regulation.
Project description:Genome-wide rhythmic occupancy of RNA polymerase II (RNAPII) is highly coordinated with rhythmic genes expression. Rhythmic RNAPII binding dynamically modulates diurnal 3D genome architecture remodeling with 91% of the chromatin interactions were altered. The rhythmic genes cluster at the 8:00 (AM) circadian phase form spatial interacting clusters in turn assist coordinated rhythmic gene expression, while non-rhythmic genes tend to tether together and contribute to expression at 20:00 (PM) circadian window. Target genes and associated cis-binding motifs of transcription factors enrichment points to the existence of subnuclear organization hub enriched around the TFs. RNAPII-associated chromatin interaction domains (CIDs) are under circadian control, and static CIDs with common node genes but changed connecting genes along the circadian cycle, reveal they may function as distinct clock components in the interconnected circuits between morning and evening. Core circadian clock genes related chromatin connectivity networks reveal a compact and highly connected chromatin architecture serving to coordinate gene expression in the morning, whereas a scattered, loose chromatin architecture coordinates PM gene expression. Our findings uncover novel diurnal fundamental genome folding principles in plants, and reveal the distinct higher-order chromosome organization that is crucial for coordinating diurnal dynamics of transcriptional regulation.
Project description:Virtually every mammalian tissue exhibits rhythmic expression in thousands of genes, which activate tissue-specific processes at appropriate times of the day. Much of this rhythmic expression is thought to be driven cell-autonomously by molecular circadian clocks present throughout the body. However, increasing evidence suggests that systemic signals, and more specifically rhythmic food intake (RFI), can regulate rhythmic gene expression independently of the circadian clock. To determine the relative contribution of cell autonomous clocks versus RFI in the regulation of rhythmic gene expression, we developed a system that allows long-term manipulation of the daily rhythm of food intake in the mouse, and analyzed liver gene expression by RNA-Seq in mice fed ad libitum, only at night, or arrhythmically (mouse eating 1/8th of their daily food intake every 3 hours). We show that 70% of the cycling mouse liver transcriptome loses rhythmicity under arrhythmic feeding. Remarkably, this loss of rhythmic gene expression under arrhythmic feeding is independent of the liver circadian clock, which continues to exhibit normal oscillations in core clock gene expression. Many genes that lose rhythmicity participate in the regulation of metabolic processes such as lipogenesis and glycogenesis, likely contributing to an increased sensitivity to insulin that was observed in arrhythmically-fed mice. We also show that night-restricted feeding significantly increases the number of rhythmically expressed genes as well as the amplitude of the rhythms. Together, these results indicate that metabolic transcription factors control a large fraction of the rhythmic mouse liver transcriptome, and demonstrate that systemic signals driven by rhythmic food intake play a more important role than the cell-autonomous circadian clock in driving rhythms in liver gene expression and metabolic functions.