Factors controlling somatic reprogramming of transformed tumorigeneic cells to induced pluripotent-like stem cells [ATAC-seq]
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ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE213167 | GEO | 2023/06/22
REPOSITORIES: GEO
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Project description:Cancer cells can only rarely be reprogrammed to induced pluripotent stem cells (iPSCs) using the overexpression of the transgenes Oct4, Sox2, Klf4, and Myc. Those cancer cells that have been reprogrammed seem to only partially complete the process and are locked in an intermediate state. There are barriers that block cancer cells from reprogramming, but the nature of those barriers is unclear. In this work, we immortalized mouse embryonic fibroblasts (MEFs) using a variety of transgenes and discovered several immortalized cell lines that remain compatible with reprogramming. We utilise the different lines to explore the factors that are compatible with reprogrmming and those that block reprogramming to pluripotent stem cells
2023-06-22 | GSE213224 | GEO
Project description:Pluripotent stem cells are derived from culture of early embryos or the germline, and can be induced by reprogramming of somatic cells. Barriers to reprogramming are expected to exist that stabilize the differentiated state and have tumor suppression functions. However, we have a limited understanding of what such barriers might be. To find novel barriers to reprogramming to pluripotency, we compared the transcriptional profiles of the mouse germline to pluripotent and somatic cells, in vivo and in vitro. There is a remarkable global expression of the transcriptional program for pluripotency in Primordial Germ Cells (PGCs). We identify parallels between PGCs reprogramming to pluripotency and human germ cell tumorigenesis, including the loss of LATS2, a tumor suppressor kinase of the Hippo pathway. We show that knockdown of LATS2 increases the efficiency of induction of pluripotency in human cells. LATS2 RNAi, unlike p53 RNAi, specifically enhances the generation of fully reprogrammed iPS cells without accelerating cell proliferation. We further show that LATS2 represses reprogramming in human cells by post-transcriptionally antagonizing TAZ but not YAP, two downstream effectors of the Hippo pathway. These results reveal transcriptional parallels between germ cell transformation and the generation of iPS cells, and indicate that the Hippo pathway constitutes a barrier to cellular reprogramming. Mouse pluripotent cells isolated directly from embryos or cultured in vitro as stem cells were analyzed using Affymetrix expression microarrays, together with several non-pluripotent cell controls, in 2-6 replicates per sample.
2012-01-31 | E-GEOD-35416 | biostudies-arrayexpress
Project description:Since the discovery of induced pluripotent stem cells there has been intense interest in understanding the mechanisms that allow a somatic cell to be reprogrammed back to a pluripotent state. Several groups have studied the alterations in gene expression that occur as somatic cells modify their genome to that of an embryonic stem cell. Underpinning many of the gene expression changes are modifications to the epigenetic profile of the associated chromatin. We have used a large-scale shRNA screen to identify epigenetic modifiers that act as barriers to reprogramming. We have uncovered an important role for TRIM28 in cells resisting transition between somatic and pluripotent states. TRIM28 achieves this by maintaining the H3K9me3 repressed state and keeping endogenous retroviruses silenced. We propose that knockdown of TRIM28 during reprogramming results in more plastic H3K9me3 domains, dysregulation of genes nearby H3K9me3 marks, and up regulation of endogenous retroviruses, thus facilitating the transition through reprogramming. Gene expression profiling using high through put sequencing at day 7 of Oct4, Sox2, Klf4 and cMyc (OSKM) expression in mouse embryonic fibroblasts with or without Trim28 / Setdb1 knockdown
2016-06-28 | E-GEOD-80550 | biostudies-arrayexpress
Project description:Pluripotent stem cells are derived from culture of early embryos or the germline, and can be induced by reprogramming of somatic cells. Barriers to reprogramming are expected to exist that stabilize the differentiated state and have tumor suppression functions. However, we have a limited understanding of what such barriers might be. To find novel barriers to reprogramming to pluripotency, we compared the transcriptional profiles of the mouse germline to pluripotent and somatic cells, in vivo and in vitro. There is a remarkable global expression of the transcriptional program for pluripotency in Primordial Germ Cells (PGCs). We identify parallels between PGCs reprogramming to pluripotency and human germ cell tumorigenesis, including the loss of LATS2, a tumor suppressor kinase of the Hippo pathway. We show that knockdown of LATS2 increases the efficiency of induction of pluripotency in human cells. LATS2 RNAi, unlike p53 RNAi, specifically enhances the generation of fully reprogrammed iPS cells without accelerating cell proliferation. We further show that LATS2 represses reprogramming in human cells by post-transcriptionally antagonizing TAZ but not YAP, two downstream effectors of the Hippo pathway. These results reveal transcriptional parallels between germ cell transformation and the generation of iPS cells, and indicate that the Hippo pathway constitutes a barrier to cellular reprogramming.
2012-01-31 | GSE35416 | GEO
Project description:Human artificial chromosomes (HACs) have unique characteristics as gene-delivery vector, e.g., episomal transmission and transfer of multiple, large transgenes. Here, we demonstrate the advantages of HAC vectors for reprogramming mouse embryonic fibroblasts (MEFs) to induced pluripotent stem (iPS) cells. Two HAC vectors (iHAC1 and iHAC2) were constructed. Both carried four reprogramming factors, and iHAC2 also encoded a p53-knockdown construct (see Kazuki et al 2011). The iHAC1 partially reprogrammed MEFs, and the iHAC2 efficiently reprogrammed MEFs. Global gene expression showed that the iHACs, unlike other vectors, generated relatively uniform iPS cells. We established iHAC-free iPS cells by isolating cells that spontaneously lost the iHAC2. Analyses of pluripotent markers, teratomas, and chimeras confirmed that these iHAC-free iPS cells were pluripotent. Moreover, iHAC-free iPS cells with a re-introduced HAC encoding Herpes Simplex Virus Thymidine Kinase were eliminated by Ganciclovir treatment; therefore, the HAC safeguard system functioned in iPS cells. Thus, the HAC vector could generate uniform, integration-free iPS cells with a safeguard system. Total RNA from mouse embryonic fibroblasts, two control ES cells (TT2 and B6ES), retrovirus vector-derived iPS cells (20D17), and twelve HAC-derived iPS clones were hybridized to the Agilent Whole Mouse Genome microarrays.
2011-10-15 | E-GEOD-29441 | biostudies-arrayexpress
Project description:Human artificial chromosomes (HACs) have unique characteristics as gene-delivery vector, e.g., episomal transmission and transfer of multiple, large transgenes. Here, we demonstrate the advantages of HAC vectors for reprogramming mouse embryonic fibroblasts (MEFs) to induced pluripotent stem (iPS) cells. Two HAC vectors (iHAC1 and iHAC2) were constructed. Both carried four reprogramming factors, and iHAC2 also encoded a p53-knockdown construct (see Kazuki et al 2011). The iHAC1 partially reprogrammed MEFs, and the iHAC2 efficiently reprogrammed MEFs. Global gene expression showed that the iHACs, unlike other vectors, generated relatively uniform iPS cells. We established iHAC-free iPS cells by isolating cells that spontaneously lost the iHAC2. Analyses of pluripotent markers, teratomas, and chimeras confirmed that these iHAC-free iPS cells were pluripotent. Moreover, iHAC-free iPS cells with a re-introduced HAC encoding Herpes Simplex Virus Thymidine Kinase were eliminated by Ganciclovir treatment; therefore, the HAC safeguard system functioned in iPS cells. Thus, the HAC vector could generate uniform, integration-free iPS cells with a safeguard system.
2011-10-16 | GSE29441 | GEO
Project description:Reprogrammed cells are reverted to non reprogrammed cell fate in a maturation step of reprogramming. Cell fate changes during reprogramming from fibroblasts to iPSC , N=60 fibrobalst lines, N=13 Undifferentiated pluripotent stem cells, N=16 Nascent reprogrammed cells, N=31
2013-07-01 | E-GEOD-47489 | biostudies-arrayexpress
Project description:Somatic cells can be reprogrammed to induced pluripotent stem cells (iPSCs) by overexpressing OCT4, SOX2, KLF4 and MYC. Although this cell fate transition is a slow and inefficient process, inhibiting several epigenetic barriers has shown to facilitate it. A previously employed epigenetic focused CRISPR-Cas9-mediated knockout screen during reprogramming uncovered novel human somatic cell reprogramming barriers. Here, I showed that USP22, target for gRNAs that were enriched in iPSCs from the screen, is a barrier for reprogramming and its loss is compatible with iPSC generation. Overexpressing wild-type or deubiquitinase mutant (C185A) USP22 in knockout background could rescue the phenotype. Additionally, knocking out other SAGA deubiquitinase subunits, ENY2 and ATXN7L3 did not increase the reprogramming efficiency. Mechanistically, we showed that USP22 loss upregulates an important pluripotency-related transcription factor, SOX2, expression even as early as 3 days after OSKM expression. We hypothesized that USP22 downregulates pluripotency-related gene expression during reprogramming independent from its SAGA integration and deubiquitinase activity. To address this, I will repeat rescuing USP22 knockout phenotype in reprogramming by overexpressing mutant versions of USP22 including K129R (acetyl inhibited) and HHAA (deubiqutinase). Additionally, I will check the expression of pluripotency-related genes at early time points of reprogramming upon USP22 knockout by transcriptome profiling. Lastly, I will generate USP22 knockout iPSC lines to force them to differentiation to observe if they have any problem with pluripotency exit. This work will establish a mechanistic understanding for the role USP22 play on both human somatic cell reprogramming, pluripotency and differentiation.
2023-07-31 | GSE225151 | GEO
Project description:Transcriptional profiling of human control and Néstor-Guillermo Progeria Syndrome (NGPS) fibroblasts and induced pluripotent stem cells (iPSCs). Somatic cell reprogramming involves rejuvenation of adult cells and relies on the ability to erase age-associated molecular marks. Accordingly, reprogramming efficiency declines with ageing, and age-associated features such as genetic instability, cell senescence or telomere shortening negatively affect this process. However, the regulatory mechanisms that constitute age-associated barriers for cell reprogramming remain largely unknown. Here, by using cells from patients with premature ageing, we demonstrate that NF-κB activation is a critical barrier for the generation of induced pluripotent stem cells (iPSCs) in ageing. We show that NF-κB repression occurs during cell reprogramming towards a pluripotent state. Conversely, ageing-associated NF-κB hyperactivation impairs generation of iPSCs by eliciting reprogramming repressors DOT1L and YY1, reinforcing cell senescence signals and down-regulating pluripotency genes. We also show that genetic and pharmacological NF-κB inhibitory strategies significantly increase the reprogramming efficiency of fibroblasts from Néstor-Guillermo Progeria Syndrome (NGPS) and Hutchinson-Gilford Progeria Syndrome (HGPS) patients, as well as from normal aged donors. Finally, we demonstrate that DOT1L inhibition in vivo ameliorates the accelerated ageing phenotype and extends lifespan in a progeroid animal model. Collectively, our results provide evidence for a novel role of NF-κB in the control of cell fate transitions and reinforce the interest of studying age-associated molecular impairments to implement cell reprogramming methodologies, and to identify new targets of rejuvenation strategies. Control and NGPS fibroblasts were reprogrammed. RNA was extracted and transcriptional profiling was obtained with GeneChip Human Exon 1.0 ST Arrays.
2015-07-01 | E-GEOD-65170 | biostudies-arrayexpress
Project description:To investigate the molecular features underlying senescence and rejuvenation during aged cell reprogramming and identify novel factors that can overcome age-associated barriers, we compared gene expression for reprogramming intermediates on D8 of tail-tip fibroblasts (TTFs) from young Wild Type (WT), old WT, and old p16 knockout (KO) mice. We collected TTFs from young WT, old WT, and old p16 KO mice and reprogrammed the cells by introducing four reprogramming factors, including Oct4, Sox2, Klf4, and c-Myc. Gene expression of reprogramming intermediates on D8 were compared. Two independent experiments were performed using different mice donors for each experiment.
2016-03-31 | E-GEOD-79747 | biostudies-arrayexpress