Glioblastoma (GBM) is a lethal brain cancer composed of heterogeneous cellular populations including glioma stem cells (GSCs) and their progeny differentiated non-stem glioma cells (NSGCs). Although accumulating evidence points out the significance of GSCs for tumour initiation and propagation, the roles of NSGCs remain elusive. Here we demonstrate that, when patient-derived GSCs in GBM tumours undergo differentiation with diminished telomerase activity and shortened telomeres, they subsequently become senescent phenotype, thereby secreting angiogenesis-related proteins, including vascular endothelial growth factors. Interestingly, these secreted factors from senescent NSGCs promote proliferation of human umbilical vein endothelial cells and tumorigenic potentials of GSCs in immunocompromised mice. These experimental data are likely clinically-relevant, since immunohistochemistry of both patient tumours of GBM and the patient GSC-derived mouse xenografted tumours detected tumour cells that express a set of markers for the senescence phenotype. Collectively, our data suggest that the inter-cellular signals from senescent NSGCs promote GBM tumour angiogenesis thereby increasing malignant progression of GBM.
Senescence from glioma stem cell differentiation promotes tumor growth.
Specimen part, Time
View SamplesLimitless reproductive potential is one of the hallmarks of cancer cells1. This ability is accomplished by maintaining telomeres, which erosion otherwise causes cellular senescence or death. Human cancer cells often maintain shorter telomeres than do cells in surrounding normal tissues2-5. While most cancer cells activate telomerase, which can elongate telomeres6, it remains elusive why cancer cells keep telomeres short. Here we show that forced elongation of telomeres in cancer cells promotes their differentiation in a tumor microenvironment in vivo. We elongated telomeres of human prostate cancer PC-3 cells, which possess short telomeres7, by enhancing their telomerase activity. The resulting cells with long telomeres retain an ability to form tumors in a mouse xenograft model. Strikingly, these tumors exhibit many duct-like structures and reduced N-cadherin expression, reminiscent of well-differentiated adenocarcinoma. These phenotypic changes are caused by telomere elongation per se but not enhanced telomerase activity. Gene expression profiling revealed that telomere elongation correlates with inhibition of cell-cycle processes. Together, our results suggest a functional contribution of short telomeres to tumor malignancy by regulating cancer cell differentiation.
Telomere length influences cancer cell differentiation in vivo.
Cell line
View SamplesLimitless reproductive potential is one of the hallmarks of cancer cells1. This ability is accomplished by maintaining telomeres, which erosion otherwise causes cellular senescence or death. Human cancer cells often maintain shorter telomeres than do cells in surrounding normal tissues2-5. While most cancer cells activate telomerase, which can elongate telomeres6, it remains elusive why cancer cells keep telomeres short. Here we show that forced elongation of telomeres in cancer cells promotes their differentiation in a tumor microenvironment in vivo. We elongated telomeres of human prostate cancer PC-3 cells, which possess short telomeres7, by enhancing their telomerase activity. The resulting cells with long telomeres retain an ability to form tumors in a mouse xenograft model. Strikingly, these tumors exhibit many duct-like structures and reduced N-cadherin expression, reminiscent of well-differentiated adenocarcinoma. These phenotypic changes are caused by telomere elongation per se but not enhanced telomerase activity. Gene expression profiling revealed that telomere elongation correlates with inhibition of cell-cycle processes. Together, our results suggest a functional contribution of short telomeres to tumor malignancy by regulating cancer cell differentiation.
Telomere length influences cancer cell differentiation in vivo.
Cell line
View SamplesTumors consist of heterogeneous cell population, containing cancer cell subpopulations with anticancer drug-resistant property, called “persister” cells. To reveal the character of the persister cells, we analyzed gene expression profile of patient-derived gastric cells and residual cancer cells after treatment with 5-FU or SN38, an active metabolite of irinotecan. In our study, we identified ALDH1A3 as a marker and a cell proliferation factor of persister cells. To examine molecular pathways regulated by ALDH1A3, we analyzed gene expression profile of patient-derived gastric JSC15-3 in which ALDH1A3 was knocked down by using shRNAs.
ALDH1A3-mTOR axis as a therapeutic target for anticancer drug-tolerant persister cells in gastric cancer.
Specimen part, Cell line, Treatment
View SamplesInduction of germline-competent pluripotent stem cells from mouse fibroblasts has been achieved by the ectopic expression of four genes (Oct3/4, Sox2, c-Myc and Klf4). If this method can be applied to humans for the generation of personalized human pluripotent stem cells, it would greatly facilitate the therapeutic application of stem cells by avoiding the problem of immune rejection by the recipient associated with allograft transplants. Here we show that the ectopic expression of the same four genes in human neonatal skin derived cells is sufficient to induce pluripotent stem cells indistinguishable from human embryonic stem cells in morphology, gene expression, DNA methylation, teratoma formation and long term self-renewal ability. Extensive analysis of colonies generated by ectopic expression of these four genes indicates the presence of considerable heterogeneity in the induced colonies. These results provide a new finding to generate human induced pluripotent stem cells from postnatal somatic tissues.
Heterogeneity of pluripotent marker gene expression in colonies generated in human iPS cell induction culture.
No sample metadata fields
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Oxidative stress activates a specific p53 transcriptional response that regulates cellular senescence and aging.
Age, Specimen part
View SamplesGene expression profiling of the medial (MGE), lateral (LGE) and caudal (CGE) ganglionic eminence, and cerebral cortex (CTX) at various embryonic stages (E12.5, E14 and E16).
Comprehensive spatiotemporal transcriptomic analyses of the ganglionic eminences demonstrate the uniqueness of its caudal subdivision.
Sex, Specimen part
View SamplesExpression in GFP vs. GFP/hTERT transduced CD8 T Lymphocytes from Healty Donors (HD) 1 and 2 at early and late passages. Using CD8+ T lymphocyte clones over-expressing telomerase we investigated the molecular mechanisms that regulate T cell proliferation. Transduction and subcloning procedures were performed on CD8 + naive T-cell clones isolated from two different healthy individuals aged between 30 to 35 years (HD1 and HD2). T-cell cloneswere transduced to express hTERT/GFP or GFP alone.
Mechanisms regulating the proliferative potential of human CD8+ T lymphocytes overexpressing telomerase.
No sample metadata fields
View SamplesUsing CD8+ T lymphocyte clones over-expressing telomerase weinvestigated the molecular mechanisms that regulate T cell proliferation. Transduction and subcloning procedures were performed on CD8 + naive T-cell clones isolated from two different healthy individuals aged between 30 to 35 years (HD1 and HD2). T-cell cloneswere transduced to express hTERT/GFP or GFP alone. HD2 was profiled on U133Plus 2.0 and submitted as a separate GEO series.
Mechanisms regulating the proliferative potential of human CD8+ T lymphocytes overexpressing telomerase.
No sample metadata fields
View SamplesUsing CD8+ T lymphocyte clones over-expressing telomerase weinvestigated the molecular mechanisms that regulate T cell proliferation. Transduction and subcloning procedures were performed on CD8 + naive T-cell clones isolated from two different healthy individuals aged between 30 to 35 years (HD1 and HD2). T-cell cloneswere transduced to express hTERT/GFP or GFP alone. HD1 was profiled on U133A and submitted as a separate GEO series.
Mechanisms regulating the proliferative potential of human CD8+ T lymphocytes overexpressing telomerase.
No sample metadata fields
View Samples