Similar Datasets
Project description:The goal of this study is to identify the senescent cells expressing high level of p16Ink4a (p16Ink4a Hi) in GBMs and characterize their action on the tumor microenvironment at an early timepoint. We introduced the p16-3MR transgene in the GBM mouse model to selectively delete p16Ink4a Hi senescent cells upon ganciclovir (GCV) injection. We compared p16-3MR+GCV to WT+GCV control GBMs that were harvested 7 days after the last GCV injection.
2022-12-15 | GSE198439 | GEO
Project description:The goal of this transcriptomic analysis is to decipher whether NRF2 pathway plays a role in the induction of pro-tumoral senescence in glioblastoma (GBM).
2022-12-15 | GSE198438 | GEO
Project description:We performed a scRNAseq analysis conducted at the endpoint of our GBM mouse model. We compared differentially expressed up-regulated genes in p16Ink4a positive vs p16Ink4a negative malignant cells. The goal was to compare this dataset with two other transcriptomic datasets, to explore the upstream regulator(s) of senescence in malignant cells. We found that Nuclear Factor Erythroid 2 Like 2 (Nfe2l2) signaling pathway was enriched in the 3 data sets.
2022-12-15 | GSE168039 | GEO
Project description:GBM mouse model: The goal of this study is to compare the transcriptomic landscape at the endpoint of GBMs upon senescent cells deletion. We introduced the p16-3MR transgene in the GBM mouse model to selectively delete senescent cells expressing high level of p16Ink4a (p16Ink4a Hi) upon ganciclovir (GCV) injection. We compared p16-3MR+GCV GBMs to two control conditions, either WT+GCV or p16-3MR+GCV. We showed a slight decreased of p16Ink4a transcripts in p16-3MR+GCV compared to WT+GCV GBMs and GSEA demonstrated significant down-regulation of senescence pathways in p16-3MR+GCV GBMs compared to control GBMs. GBM-derived organoids: We used a mouse GBM-derived organoids model to further explore the function of Nrf2, that we identified as one potential trigger of the pro-tumoral action of p16Ink4a Hi malignant cells. We compared GBM-derived organoids treated with the senolytic ABT263 (Navitoclax; inhibitor of the anti-apoptotic proteins Blcl2 and BCL-xL) or vehicle (vhc) after 14 days in culture. We validated ABT263 efficacy via the significant downregulation of the expression of p16Ink4a, p15Ink4b and p21Cip1 senescent markers. We further identified upon senolytic treatment, downregulated genes encoding for SASP. Importantly, GSEA revealed a significant downregulation of Nrf2 pathway upon senolytic treatment.
2022-12-15 | GSE168037 | GEO
Project description:The goal of this study is to identify the senescent cells expressing high level of p16Ink4a (p16Ink4a Hi) in GBMs, at an early timepoint. We introduced the p16-3MR transgene in the GBM mouse model to selectively delete p16Ink4a Hi senescent cells upon ganciclovir (GCV) injection. We compared two p16-3MR+GCV to two WT+GCV control GBMs that were harvested 7 days after the last GCV injection. p16Ink4a Hi senescent cells were a subset of malignant cells, mostly grouped in the astrocyte cluster and to a lesser extend in the NP-like cluster. We also found that p16Ink4a Hi senescent cells deletion modifies the cell state of malignant cells and modulates the tumor microenvironment. This study allowed us to define a GBM senescence signature.
2022-12-15 | GSE168038 | GEO
Project description:Six1 is a developmental transcriptional regulator frequently overexpressed in human tumors. Recent results show that SIX1 also acts as a repressor of cell senescence, an antiproliferative response with a key role in tumor suppression, among other physiological and pathological settings. Here, we set to study the impact of SIX1 gain of function in transformation and tumorigenesis of fibroblasts, in connection with senescence. Using transcriptomic, histological, and functional analyses in murine tumors and cells of fibroblast origin, we show that SIX1 has a strong pro-tumorigenic action in this model, linked to the repression of a senescence-related gene signature and the induction of an undifferentiated phenotype mediated, at least in part, by the regulation of the stemness factor Sox2. Moreover, functional analyses with human glioma cell lines also show that SIX1 controls SOX2 expression, senescence and self-renewal in this model. Collectively, our results support a general link of SIX1 with senescence and SOX2-mediated cell plasticity in tumors.
| S-EPMC6363751 | biostudies-literature
Project description:This SuperSeries is composed of the SubSeries listed below.
2021-06-04 | GSE160444 | GEO
Project description:Tumor suppressor p53-dependent apoptosis is critical in suppressing tumorigenesis. Previously, we reported that DNA double-strand breaks (DSBs) at the V(D)J recombination loci induced genomic instability in the developing lymphocytes of nonhomologous end-joining (NHEJ)-deficient, p53-deficient mice, which led to rapid lymphomagenesis. To test the ability of p53-dependent cell cycle arrest to suppress tumorigenesis in the absence of apoptosis in vivo, we crossbred NHEJ-deficient mice into a mutant p53R172P background; these mice have defects in apoptosis induction, but not cell cycle arrest. These double-mutant mice survived longer than NHEJ/p53 double-null mice and, remarkably, were completely tumor free. We detected accumulation of aberrant V(D)J recombination-related DSBs at the T cell receptor (TCR) locus, and high expression levels of both mutant p53 and cell cycle checkpoint protein p21, but not the apoptotic protein p53-upregulated modulator of apoptosis. In addition, a substantial number of senescent cells were observed among both thymocytes and bone marrow cells. Cytogenetic studies revealed euploidy and limited chromosomal breaks in these lymphoid cells. The results indicate that precursor lymphocytes, which normally possess a high proliferation potential, are able to withdraw from the cell cycle and undergo senescence in response to the persistence of DSBs in a p53-p21-dependent pathway; this is sufficient to inhibit oncogenic chromosomal abnormality and suppress tumorigenesis.
| S-EPMC2118600 | biostudies-literature
Project description:BackgroundMER receptor tyrosine kinase (MERTK) is expressed in a variety of malignancies, including glioblastoma multiforme (GBM). Our previous work demonstrated that inhibition of MERTK using RNA interference induced cell death and chemosensitivity in GBM cells, implicating MERTK as a potential therapeutic target. Here we investigate whether a novel MERTK-selective small molecule tyrosine kinase inhibitor, UNC2025, has similar anti-tumor effects in GBM cell lines.MethodsCorrelations between expression of GAS6, a MERTK ligand, and prognosis were determined using data from the TCGA database. GBM cell lines (A172, SF188, U251) were treated in vitro with increasing doses of UNC2025 (50-400nM). Cell count and viability were determined by trypan blue exclusion. Cell cycle profiles and induction of apoptosis were assessed by flow cytometric analysis after BrdU or Po-Pro-1/propidium iodide staining, respectively. Polyploidy was detected by propidium iodide staining and metaphase spread. Cellular senescence was determined by ?-galactosidase staining and senescence-associated secretory cytokine analysis.ResultsDecreased overall survival significantly correlated with high levels of GAS6 expression in GBM, highlighting the importance of TAM kinase signaling in GBM tumorigenesis and/or therapy resistance and providing strong rationale for targeting these pathways in the clinic. All three GBM cell lines exhibited dose dependent reductions in cell number and colony formation (>90% at 200nM) after treatment with UNC2025. Cell cycle analysis demonstrated accumulation of cells in the G2/M phase and development of polyploidy. After extended exposure, 60-80% of cells underwent apoptosis. The majority of surviving cells (65-95%) were senescent and did not recover after drug removal. Thus, UNC2025 mediates anti-tumor activity in GBM by multiple mechanisms.ConclusionsThe findings described here provide further evidence of oncogenic roles for MERTK in GBM, demonstrate the importance of kinase activity for MERTK tumorigenicity and validate UNC2025, a novel MERTK inhibitor, as a potential therapeutic agent for treatment of GBM.
| S-EPMC5081168 | biostudies-literature
Project description:This SuperSeries is composed of the SubSeries listed below. Refer to individual Series
2015-05-06 | E-GEOD-61651 | biostudies-arrayexpress