Project description:This study explores the circuit integration of human glioblastoma organoids (GBOs) in vivo in the adult mouse brain. Here, we performed RNA sequencing analysis of GBOs at baseline conditions and various treatment timepoints of 1 mM acetylcholine (ACh). RNA sequencing analysis was also performed on GBOs with CHRM3 knockdown.
Project description:This study explores the circuit integration of human glioblastoma organoids (GBOs) in vivo in the adult mouse brain. We performed single cell RNA sequencing (scRNA-seq) to understand the cell state diversity of malignant tumor cells in GBOs at baseline and after stimulation by 1 mM acetylcholine (ACh) for 1 hour. Sliced neocortical organoids (SNOs) were also sequenced to study gene expression properties of neural stem cells (NSCs).
Project description:Gene expression profiling of distinct members of a neuronal circuit has the potential to identify candidate molecules and mechanisms that underlie the formation, organization and function of the circuit. To this end, we report here the application of a novel method to characterize RNAs from small numbers of specific Drosophila brain neurons, which belong to the circadian circuit. We identified three different sets of mRNAs enriched in different subclasses of clock neurons: one is enriched in all clock neurons, a second is enriched in PDF-positive clock neurons and a third is enriched in PDF-negative clock neurons. Moreover, we characterized 2 novel genes, Fer2 and dnocturnin, one from each subgroup, which highlight subgroup-specific features and play important roles in circadian rhythms. The methodology is a powerful tool not only to dissect the cellular and molecular basis of circadian rhythms but also to molecularly characterize other Drosophila neuronal circuits. Experiment Overall Design: Circadican related neuronal celltypes (Tim, Pdf) or general neurons (Elav) were labeled by GFP or YFP using specific Gal4 drivers. Expression of those celltypes were profiled after manual sorting of those GFP or YFP positive cells. 3 biological replicates were collected (except adult small pdf cells).
Project description:We have developed a nonheuristic genome topography scan (GTS) algorithm to characterize the patterns of genomic alterations in human glioblastoma (GBM), identifying frequent p18INK4C and p16INK4A codeletion. Functional reconstitution of p18INK4C in GBM cells null for both p16INK4A and p18INK4C resulted in impaired cell-cycle progression and tumorigenic potential. Conversely, RNAi-mediated depletion of p18INK4C in p16INK4A-deficient primary astrocytes or established GBM cells enhanced tumorigenicity in vitro and in vivo. Furthermore, acute suppression of p16INK4A in primary astrocytes induced a concomitant increase in p18INK4C. Together, these findings uncover a feedback regulatory circuit in the astrocytic lineage and demonstrate a bona fide tumor suppressor role for p18INK4C in human GBM wherein it functions cooperatively with other INK4 family members to constrain inappropriate proliferation. Keywords: SuperSeries DNA copy number and mRNA transcriptome of human glioblastoma tumors were profiled using Agilent and Affymetrix microarrays. This SuperSeries is composed of the following subset Series: GSE7602: Human GBM tumor vs Normal Human DNA GSE9171: Expression data from human GBM tumors and cell lines GSE9177: Human GBM tumor vs Normal Human DNA
Project description:Gene expression profiling of distinct members of a neuronal circuit has the potential to identify candidate molecules and mechanisms that underlie the formation, organization and function of the circuit. To this end, we report here the application of a novel method to characterize RNAs from small numbers of specific Drosophila brain neurons, which belong to the circadian circuit. We identified three different sets of mRNAs enriched in different subclasses of clock neurons: one is enriched in all clock neurons, a second is enriched in PDF-positive clock neurons and a third is enriched in PDF-negative clock neurons. Moreover, we characterized 2 novel genes, Fer2 and dnocturnin, one from each subgroup, which highlight subgroup-specific features and play important roles in circadian rhythms. The methodology is a powerful tool not only to dissect the cellular and molecular basis of circadian rhythms but also to molecularly characterize other Drosophila neuronal circuits.
Project description:Animals use spatial differences in environmental light levels for visual navigation; however, how light inputs are translated into coordinated motor outputs remains poorly understood. Here we reconstruct the neuronal connectome of a four-eye visual circuit in the larva of the annelid Platynereis using serial-section transmission electron microscopy. In this 71-neuron circuit, photoreceptors connect via three layers of interneurons to motorneurons, which innervate trunk muscles. By combining eye ablations with behavioral experiments, we show that the circuit compares light on either side of the body and stimulates body bending upon left-right light imbalance during visual phototaxis. We also identified an interneuron motif that enhances sensitivity to different light intensity contrasts. The Platynereis eye circuit has the hallmarks of a visual system, including spatial light detection and contrast modulation, illustrating how image-forming eyes may have evolved via intermediate stages contrasting only a light and a dark field during a simple visual task.
Project description:Purpose: To test the neuronal conversion and other effects induced by neural transcription factor Neurog2 or Ascl1 in human glioblastoma cells Methods: Retroviral expression of Ascl1, Neurog2 or control GFP in cultured human U251 cells at 6 DPI
Project description:Glioblastoma recurrence originates from invasive cells that escape surgical resection, but their biology remains poorly understood. Here we generated three somatic mouse models recapitulating the main driver mutations of the human disease to characterise the infiltrative tumour margin. We find that, regardless of genetics, tumours are fuelled by highly proliferative glioma stem-like cells (GSCs) resembling active neural stem cells (NSCs), which recapitulate normal and injury-induced neurogenesis in both bulk and margin. Surprisingly, GSCs are evenly distributed across both regions, suggesting that invasive potential is uncoupled from stemness. However, tumour region influences fate choice, with margin cells progressing towards astrocyte-like, and bulk cells towards injured NSC-like (iNSCs) fates. iNSCs account for a significant proportion of dormant glioblastoma cells and are induced by interferon signalling within T-cell-rich niches that form selectively in the bulk. These findings identify key differences between bulk and margin and indicate that glioblastoma cell fate is under cell-extrinsic control.
Project description:We have developed a nonheuristic genome topography scan (GTS) algorithm to characterize the patterns of genomic alterations in human glioblastoma (GBM), identifying frequent p18INK4C and p16INK4A codeletion. Functional reconstitution of p18INK4C in GBM cells null for both p16INK4A and p18INK4C resulted in impaired cell-cycle progression and tumorigenic potential. Conversely, RNAi-mediated depletion of p18INK4C in p16INK4A-deficient primary astrocytes or established GBM cells enhanced tumorigenicity in vitro and in vivo. Furthermore, acute suppression of p16INK4A in primary astrocytes induced a concomitant increase in p18INK4C. Together, these findings uncover a feedback regulatory circuit in the astrocytic lineage and demonstrate a bona fide tumor suppressor role for p18INK4C in human GBM wherein it functions cooperatively with other INK4 family members to constrain inappropriate proliferation. This SuperSeries is composed of the SubSeries listed below.