Project description:Analysis of Hoechst 33342 dye-effluxing side population cells (SP cells defined as glioma stem cells, GSCs) and dye-retaining main population cells (MP cells defined as non-GSCs) that were FACS-sorted from the C6 glioma cell line stably expressing EGFP (C6-eGFP). ECM-related genes, such as Col4a1 and Col4a2, and the iron carrier gene Tf are upregulated in MP cells. Results provide the insight into molecular basis underlying the maintenance of GSCs by non-GSCs. Gene expression profiles were compared between SP and MP cells just after FACS-sorting from the whole C6-eGFP cells based on their Hoechst-effluxing abilities.
Project description:Analysis of Hoechst 33342 dye-effluxing side population cells (SP cells defined as glioma stem cells, GSCs) and dye-retaining main population cells (MP cells defined as non-GSCs) that were FACS-sorted from the C6 glioma cell line stably expressing EGFP (C6-eGFP). ECM-related genes, such as Col4a1 and Col4a2, and the iron carrier gene Tf are upregulated in MP cells. Results provide the insight into molecular basis underlying the maintenance of GSCs by non-GSCs.
Project description:Glioblastomas show heterogeneous histological features. These distinct phenotypic states are thought to be associated with the presence of glioma stem cells (GSCs), which are highly tumorigenic and self-renewing sub-population of tumor cells that have different functional characteristics. To investigate Glioblastomas (GBMs) show heterogeneous histological features. These distinct phenotypic states are thought to be originated by the glioma stem cells (GSCs), which are highly tumorigenic and self-renewing sub-population of tumor cells. Notch signaling has been shown to be important for maintenance of GSC population both in vitro and in vivo. A recent study showed that NOTCH -triggered oncogenic activity can be due to not only its ability to regulate coding genes but also long non-coding RNAs (lncRNAs). Here, we investigated the molecular effects of lncRNA in GSC, whose expression is induced by Notch signaling. We searched for downregulated lncRNAs in GSCs by treatment of small interfering RNA (siRNA) targeting Notch1 and JAG1 (si-Notch1 and si-JAG1).
Project description:Abnormal activation of stemness factors is a crucial signature of cancer stem cells (CSCs), a highly tumorigenic subpopulation in malignant tumors. However, it is unclear whether multi-signaling pathways are activated in CSCs, as like normal stem cells. I would like to report that an inhibitor of differentiation 1 (ID1) activates intracellular multi-signaling involved in proliferation, genesis, and maintenance of glioma stem cells (GSCs) by suppression of Cullin3, an E3 ubiquitin ligase that degrades Cyclin E and components of SHH and WNT signaling. ID1 inhibits BMP-dependent differentiation of GSCs by activation of BMPR2-targeting miR17/20a. ID1HIGH-Cullin3LOW signature correlates with a poor prognosis of GBM patients with a significant association to gene signatures enriched in EGF, WNT, SHH, and BMP signaling. Combinational inhibition of GSC intracellular multi-signaling network increases tumor-bearing mice survival. These results provide insights on molecular and cellular basis of GSC biology, and also suggest necessity of multi-signaling inhibition for GSCs therapy. Two human primary glioma stem cells (GSCs) such as GSC2 and GSC8 were isolated from two individual primary human glioma specimens. The GSCs were directly transfected with pSuper-GFP-ID1-shRNA and pSuper-GFP-Scrambled-shRNA using FuGENE 6 reagent (Roche). The RNA extraction in these cells was used to analyze gene expression.
Project description:The pluripotency transcription factor SOX2 is essential for the maintenance of glioblastoma stem cells (GSC), which drive tumor growth and treatment resistance.To understand how SOX2 is regulated in GSCs, we utilized a proteomic approach and identified the E3 ubiquitin ligase TRIM26 as a direct SOX2-interacting protein. Unexpectedly, we found TRIM26 depletion decreased SOX2 protein levels and increased SOX2 polyubiquitination in patient-derived GSCs, suggesting TRIM26 promotes SOX2 protein stability. Accordingly, TRIM26 knockdown reduced SOX2 transcriptional activity, self-renewal capacity, and in vivo tumorigenicity in multiple GSC lines. Mechanistically, we found TRIM26, via its C-terminal PRYSPRY domain, but independent of its RING domain, stabilizes SOX2 protein by directly inhibiting the interaction of SOX2 with WWP2, which we identify as a bona fide SOX2 E3 ligase in GSCs. Our work identifies E3 ligase competition as a critical mechanism of SOX2 regulation, with functional consequences for GSC identity and maintenance.
Project description:Glioblastomas show heterogeneous histological features. These distinct phenotypic states are thought to be associated with the presence of glioma stem cells (GSCs), which are highly tumorigenic and self-renewing sub-population of tumor cells that have different functional characteristics. To investigate Glioblastomas (GBMs) show heterogeneous histological features. These distinct phenotypic states are thought to be originated by the glioma stem cells (GSCs), which are highly tumorigenic and self-renewing sub-population of tumor cells. Notch signaling has been shown to be important for maintenance of GSC population both in vitro and in vivo. A recent study showed that NOTCH -triggered oncogenic activity can be due to not only its ability to regulate coding genes but also long non-coding RNAs (lncRNAs). Here, we investigated the molecular effects of lncRNA in GSC, whose expression is induced by Notch signaling. We searched for downregulated lncRNAs in GSCs by treatment of small interfering RNA (siRNA) targeting Notch1 and JAG1 (si-Notch1 and si-JAG1) and γ-secretase inhibitors (N-S-phenyl-glycine-t-butyl ester (DAPT) and RO4929097) using SurePrint G3 Human GE 8×60K array slides (G4851B, Agilent Technologies).gene expression profiling in GSC, we have performed microarray experiment using Agilent Whole Human Genome Oligo Microarrays (G4112F).
Project description: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. We monitored gene expression profiling in GSC, differentiated NSGC (GSC at day7 after serum exposure), and senescent NSGC (GSC at day30 after serum exposure) of GBM146 and GBM157.