Project description:Glioblastoma multiforme (GBM), a highly malignant and heterogeneous brain tumor, contains various types of tumor and non-tumor cells. Whether GBM cells can trans-differentiate into non-neural cell types, including mural cells or endothelial cells, to support tumor growth and invasion remains controversial. Here we generated two genetic GBM models de novo in immunocompetent mouse brains, mimicking essential pathological and molecular features of human GBMs. Single-cell RNA sequencing showed that patterns of copy-number variations (CNVs) of mural cells and endothelial cells were distinct from those of GBM cells, indicating discrete origins of GBM cells and vascular components. Furthermore, lineage tracing and transplantation studies demonstrated that, although blood vessels in GBM brains underwent drastic remodeling, GBM cells did not give rise to non-neural cell types in the brain. Intriguingly, GBM cells could randomly express mesenchymal markers, including those for mural cells, during gliomagenesis. Most importantly, single-cell CNV analysis of human GBM specimens also strongly suggested that GBM cells and vascular cells are separate lineages. Instead, non-neural cell types expanded by proliferation during tumorigenesis. Therefore, cross-lineage trans-differentiation of GBM cells is very unlikely to occur during gliomagenesis. Our findings advance understanding of cell lineage dynamics during gliomagenesis, and have implications for targeted treatment of GBMs.
Project description:Purpose: Investigate cellular heterogeneity in a fresh human ovarian cancer tissue sample Methods: Enzymatic digestion of fresh tissue sample collected from the operating room to produce single cell suspension. Cells were labelled with fluorescent antibodies to CD3, CD14, CD19, CD20, CD56 and FACS sorted to remove immune cells. The negative population was used for sequencing. Single cells were processed using the Fluidigm C1 Chip to generate barcoded cDNA for each cell. Amplifed cDNA was sequenced using an Illumina HiSeq 2500 machine. Results: Single cell RNA sequence data was obtained for 92 cells and a "bulk" sample of 1000 cells. 26 cells were removed from analysis due to quality control standards. The remaining 66 cells and the bulk sample were analyzed. Conclusion: Single cell RNA sequence analysis reveals heterogeneity in gene expression in cells harvested from a high grade ovarian serous cancer
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: comparative genomic hybridization DNA copy number abberation of human glioblastoma tumors were obtained by comparative genomic hybridization of GBM tumor vs. normal human DNA. 11 human GBM samples were analyzed on Agilent human 244A human cgh array (G4411B). Normal Human DNA was used as reference. Some samples were hybridized with dye-swap replica.
Project description:Glioblastoma (GBM) is the most common and malignant primary brain tumor. Although immunotherapy has shown promise in certain cancer types, it has not been effective against GBM, largely due to its highly immunosuppressive tumor microenvironment (TMEs), which is rich in tumor-associated macrophages/microglia (TAMs). TAMs in late-stage GBM contribute to T-cell exhaustion and worsen prognosis, but the role of TAMs in earlier stages of tumor development is unclear. By employing genetically engineered mouse models and human samples, we used spatiotemporal single-cell transcriptomics to investigate TAM evolution during GBM progression.
Project description:Glioblastoma multiforme (GBM), a highly malignant and heterogeneous brain tumor, contains various types of tumor and non-tumor cells. Whether GBM cells can trans-differentiate into non-neural cell types, including mural cells or endothelial cells, to support tumor growth and invasion remains controversial. Here we generated two genetic GBM models de novo in immunocompetent mouse brains, mimicking essential pathological and molecular features of human GBMs. Single-cell RNA sequencing showed that patterns of copy-number variations (CNVs) of mural cells and endothelial cells were distinct from those of GBM cells, indicating discrete origins of GBM cells and vascular components. Furthermore, lineage tracing and transplantation studies demonstrated that, although blood vessels in GBM brains underwent drastic remodeling, GBM cells did not give rise to non-neural cell types in the brain. Intriguingly, GBM cells could randomly express mesenchymal markers, including those for mural cells, during gliomagenesis. Most importantly, single-cell CNV analysis of human GBM specimens also strongly suggested that GBM cells and vascular cells are separate lineages. Instead, non-neural cell types expanded by proliferation during tumorigenesis. Therefore, cross-lineage trans-differentiation of GBM cells is very unlikely to occur during gliomagenesis. Our findings advance understanding of cell lineage dynamics during gliomagenesis, and have implications for targeted treatment of GBMs.
Project description:Recent advances in glioblastoma (GBM) studies provide a comprehensive catalog of its genetic aberrations and cellular heterogeneity. However, a solid understanding of genotype-based analysis of cancer pathway dependency and actionable target identification is required to transform GBM treatment into a personalized era. Here, we generated a spectrum of mutant iPSCs harboring frequent GBM mutations with CRISPR/Cas9 and profiled the organoids (LEGO: Laboratory Engineered Glioblastoma Organoid) derived from these iPSCs temporally on transcriptome, methylome, metabolome, lipidome, proteome, and phospho-proteome levels. We found that LEGOs form brain tumors in vivo and recapitulate critical features of human GBM. The multi-omics analysis discovered essential milestones driven by genetic heterogeneity during GBM progressions, such as lineage alteration, methylome rewriting, and metabolome/lipidome reprogramming, in concordance with altered pathway activity and drug response. This study provides a tool and research path to realizing genome-based personalized GBM therapy using novel advanced models.