Genome-wide transcriptional profiling of primary human AML samples with distinct susceptibilities to telomerase inhibition
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE63146 | GEO | 2014/11/11
SECONDARY ACCESSION(S): PRJNA266812
REPOSITORIES: GEO
Similar Datasets
Project description:A gene expression signature classifying telomerase and ALT immortalisation reveals an hTERT regulatory network and suggests a mesenchymal stem cell origin for ALT Telomere length is maintained by 2 known mechanisms, activation of telomerase or alternative lengthening of telomeres (ALT). The molecular mechanisms regulating the ALT phenotype are poorly understood and it is unknown how the decision of which pathway to activate is made at the cellular level. We have shown previously that active repression of telomerase gene expression by chromatin remodelling of the promoters is one mechanism of regulation, however other genes and signalling networks are likely to be required to regulate telomerase and maintain the ALT phenotype. Using gene expression profiling we have uncovered a signature of 1305 genes to distinguish telomerase positive and ALT cell lines. By combining this with gene expression profiles of liposarcoma tissue samples we refined this signature to 297 genes significantly associated with telomere maintenance mechanism. Network analysis of known direct interactions between genes within this signature revealed a regulatory signalling network consistent with a model of hTERT repression in ALT cell lines and liposarcomas. This network expands on our existing knowledge of hTERT regulation and provides a platform to understand differential regulation of hTERT in different tumour types and normal tissues. In addition we show evidence to suggest a novel mesenchymal stem cell origin for ALT immortalisation in cell lines and mesenchymal tissues. Keywords: cell type comparison, gene expression
2009-11-02 | GSE14529 | GEO
Project description:A gene expression signature classifying telomerase and ALT immortalisation reveals an hTERT regulatory network and suggests a mesenchymal stem cell origin for ALT Telomere length is maintained by 2 known mechanisms, activation of telomerase or alternative lengthening of telomeres (ALT). The molecular mechanisms regulating the ALT phenotype are poorly understood and it is unknown how the decision of which pathway to activate is made at the cellular level. We have shown previously that active repression of telomerase gene expression by chromatin remodelling of the promoters is one mechanism of regulation, however other genes and signalling networks are likely to be required to regulate telomerase and maintain the ALT phenotype. Using gene expression profiling we have uncovered a signature of 1305 genes to distinguish telomerase positive and ALT cell lines. By combining this with gene expression profiles of liposarcoma tissue samples we refined this signature to 297 genes significantly associated with telomere maintenance mechanism. Network analysis of known direct interactions between genes within this signature revealed a regulatory signalling network consistent with a model of hTERT repression in ALT cell lines and liposarcomas. This network expands on our existing knowledge of hTERT regulation and provides a platform to understand differential regulation of hTERT in different tumour types and normal tissues. In addition we show evidence to suggest a novel mesenchymal stem cell origin for ALT immortalisation in cell lines and mesenchymal tissues. Keywords: cell type comparison, gene expression
2009-11-02 | GSE14487 | GEO
Project description:Relapse in acute myeloid leukemia (AML) may result from variable genetic origins or convergence on common biological processes. Exploiting the specificity and sensitivity of regulatory DNA, we analyze patient samples of multiple clinical outcomes covering various AML molecular subtypes. We uncover regulatory variation between patients translating into a transcriptional signature that predicts relapse risk. In addition, we find clusters of co-expressed genes within this signature selectively link to relapse risk in distinct patient subgroups defined by molecular subtype or AML maturation. Analyzing these gene clusters and the AML subtypes separately enhances their prognostic value substantially and provides insight in the mechanisms underlying relapse risk across the distinct patient subgroups. We propose that prognostic gene expression signatures in AML are valid only within patient subgroups and do not transcend these subgroups.
2019-09-10 | GSE117994 | GEO
Project description:Telomere shortening due to telomerase deficiency leads to accelerated senescence of human skeletal (mesenchymal) stem cells (MSC) in vitro. In order to study the role of telomere shortening in vivo, we studied the phenotype of telomerase deficient mice caused by absence of telomerase RNA component (TERC-/-). TERC-/- exhibited accelerated age-related bone loss starting at 3 months of age and during 12 months follow up. Bone histomorphometry revealed decreased mineralized surface and bone formation rate as well as increased osteoclast number and size in TERC-/-. Also, serum total deoxy-pyridinoline (tDPD) was increased in TERC-/-. MSC isolated from TERC-/- exhibited intrinsic defects with reduced total number, lower proliferation rate, decreased expression of osteoblastic (OB) differentiation markers and formed less in vivo ectopic bone compared to WT cells. The TERC-/--MSC cultures accumulated a larger proportion of senescent Ã-galactosidase+ cells and cells exhibiting DNA damage positive for γ-H2AX. Micro-array analysis of bones of TERC-/- and WT revealed significant over-expression of a large number of pro-inflammatory genes and signaling pathways in TERC-/- known to control osteoclast (OC) differentiation. In accordance with that, serum from TERC-/- enhanced OC formation in control bone marrow cultures. Our data demonstrate two mechanisms for age-related bone loss caused by telomerase deficiency: intrinsic osteoblastic defects and creation of pro-inflammatory osteoclast-activating microenvironment. Approaches for re-telomerization of MSC may provide a novel approach for abolishing age-related bone loss. control (WT) and the test (G3 - mTERC-/-) samples
2010-05-27 | E-GEOD-21523 | biostudies-arrayexpress
Project description:Standard and targeted therapies almost universally fail due to tumor heterogeneity/plasticity leading to intrinsic or acquired drug resistance. We used the telomerase substrate precursor 6-thio-2’-deoxyguanosine (6-thio-dG) to target telomerase-expressing targeted therapy and platin-doublet chemotherapy resistant cells. We observed that erlotinib, paclitaxel/carboplatin and gemcitabine/cisplatin resistant cells are sensitive to 6-thio-dG in xenograft, syngeneic immunocompetent and genetically engineered mouse models. We also show sensitivity to 6-thio-dG on a large panel of non-small cell lung cancer cell lines (73 of 77). The 4 resistant NSCLC lines clustered together, providing a molecular signature for patients that may not respond to 6-thio-dG. We find SLC43A3 as a top candidate in this molecular signature. Thus, 6-thio-dG may prolong disease control of therapy-resistant lung cancer patients.
2018-01-30 | GSE109821 | GEO
Project description:Genome-wide transcriptional profiling of purified telomerase deficient (Terc-/-) and WT LSCs was performed in order to gain insights into the mechanisms underlying the susceptibilities of Terc-/- LSCs in vivo. Results provide important information on the response of LSCs to telomerase deficiency, such as telomerase-dependent genes, and dysregulated cellular functions including cell cycle, DNA replication, recombination and repair, altered cellular morphology, cellular function and maintenance, and activated programmed cell death. Total RNA obtained from G3 Terc-/- LSCs compared to WT LSCs (MLLAF9gfp+, lin-, kit+, Fcgr+) purified from primary recipients at individual disease onset.
2014-11-14 | E-GEOD-63241 | biostudies-arrayexpress
Project description:Genome-wide transcriptional profiling of purified telomerase deficient (Terc-/-) and WT LSCs was performed in order to gain insights into the mechanisms underlying the susceptibilities of Terc-/- LSCs in vivo. Results provide important information on the response of LSCs to telomerase deficiency, such as telomerase-dependent genes, and dysregulated cellular functions including cell cycle, DNA replication, recombination and repair, altered cellular morphology, cellular function and maintenance, and activated programmed cell death.
2014-11-14 | GSE63241 | GEO
Project description:Telomeres shorten with each round of cell division, and the expression of telomerase serves to lengthen telomeres. In the absence of telomerase, telomeres shorten to the point of uncapping and causes defects in tissues with high turnover, including the intestinal epithelium. In mice lacking telomerase (e.g. mTR-/-), telomeres critically shorten after several generations of telomerase deficiency, with pronounced defects in their intestine. Crypt epithelium and underlying stroma were each isolated from wild type (WT) and late generation (4th generation or G4) mice and used for mRNA expression profiling.
2017-01-01 | GSE90820 | GEO
Project description:Single-strand selective uracil DNA-glycosylase (SMUG1) associates with the DKC1-H/ACA ribonucleoprotein complex, which is essential for telomerase biogenesis. We show herein, that SMUG1 interacts with the telomerase RNA component, hTERC, and is required for co-transcriptional processing of the nascent transcript towards mature hTERC. We demonstrate that SMUG1 regulates the presence of base modifications between the CR4/CR5 region and the H-box situated towards the 3´-end of hTERC. Increased levels of hTERC base modifications are accompanied by reduced DKC1 binding. Loss of SMUG1 leads to an imbalance between mature hTERC and its processing intermediates, leading to the accumulation of 3´-polyadenylated and 3´-extended intermediates that are degraded in an EXOSC10-independent RNA degradation pathway. Consequently, SMUG1-deprived cells, present telomerase deficiency leading to impaired bone marrow proliferation in SMUG1-knockout mice.
2019-08-11 | GSE116580 | GEO
Project description:Critically short telomeres activate p53-mediated apoptosis, resulting in organ failure and causing malignant transformation. Mutations in genes responsible for telomere maintenance are linked to a number of specific human diseases. We derived induced pluripotent stem cells (iPSCs) from patients with mutations in the TERT and TERC telomerase genes. Telomerase-mutant iPSCs elongated telomeres, but at a lower rate than healthy iPSCs, and the magnitude of the elongation deficit correlated with the specific mutation’s impact on telomerase activity. However, elongation significantly varied among iPSC clones harboring the same mutation, and was affected by genetic and environmental factors. iPSCs cultured in hypoxia showed increased telomere length. Potential influence of residual expression of reprogramming factors on telomerase regulation and telomere length was ruled out by excising the transgenes after successful reprogramming. Evidence for telomerase-independent telomere elongation was not observed in these cells. We demonstrate that telomerase is required for telomere elongation in iPSCs and uncover heterogeneity in telomere maintenance even between clones derived from individual patients or siblings with the same mutation, indicating that telomere phenotype may be influenced by acquired and environmental agents. Our data underscore the necessity of studying multiple clones when using iPSCs to model disease. The exon array were done to validate the pluripotent phenotype of the derived normal and telomerase mutant iPSC and to potentially identify differentially expressed genes in mutant iPSC. Objective: confirming pluripotency by comparing telomerase mutated-, control-iPSC to human ESC and to their parental somatic cells (fibroblast used for iPSC derivation) 20 samples total, 5 different fibroblast cells, 13 iPSC lines, 1 ES line (H1) from different passages
2013-02-11 | E-GEOD-42869 | biostudies-arrayexpress