Genome-wide Oct4 binding profile in lung cancer A549 cells
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ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE58462 | GEO | 2015/02/04
SECONDARY ACCESSION(S): PRJNA253167
REPOSITORIES: GEO
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Project description:Oct4 stemness gene encoding a transcription factor has been shown to overexpress in cancers. However, precise mechanisms of Oct4 relevant to transcriptional reprogramming leading to somatic cancer progression remain unclear. To address the Oct4-mediated transcriptional program in lung cancer, we integrated genome-wide Oct4 binding profiles from chromatin-immunoprecipitation sequencing and ENCODE datasets. We identified that Oct4 occupied at functional promoter and enhancer regions of genes which play key roles in several signaling pathways involving tumorigenesis. Genome-wide Oct4 binding sites were identified via chromatin immunoprecipitation-sequencing analysis of vecoter control and stably Oct4-overexpressing A549 lung cancer cells. ChIP-seq analyses were performed in duplicated samples using Applied Biosystems SOLiD system.
2015-02-04 | E-GEOD-58462 | biostudies-arrayexpress
Project description:E7 modulates Oct4 re-expression in cervical cancer
2023-04-06 | MSV000091651 | MassIVE
Project description:The Octamer-binding transcription factor-4 (Oct4) is upregulated in different malignancies, yet a paradigm for mechanisms of Oct4 post-embryonic re-expression is inadequately understood. In cervical cancer, Oct4 expression is higher in HPV-related than HPV-unrelated cervical cancers and this upregulation correlates with the expression of the E7 oncogene. We have reported that E7 affects the Oct4-transcriptional output and Oct4-related phenotypes in cervical cancer, however, the underlying mechanism remains elusive. Here, we characterize the Oct4-protein interactions in cervical cancer cells and reveal that Methyl-binding proteins (MBD2 and MBD3), are determinants of Oct4 driven transcription. E7 triggers MBD2 downregulation and TET1 upregulation, thereby disrupting the methylation status of the Oct4 gene. This coincides with an increase in the total DNA hydroxymethylation leading to the re-expression of Oct4 in cervical cancer and likely affecting broader transcriptional patterns. Our findings reveal a previously unreported mechanism by which the E7 oncogene can regulate transcription by increasing DNA hydroxymethylation and lowering the barrier to cellular plasticity during carcinogenesis.
2023-12-11 | GSE248367 | GEO
Project description:Oct4 is considered a master transcription factor for pluripotent cell self-renewal and embryo development. It primarily collaborates with other transcriptional factors or coregulators to maintain pluripotency. However, it is still unclear how Oct4 interacts with its partners. Here, we show that the Oct4 linker interface mediates competing and balanced Oct4 protein interactions which are crucial for maintaining pluripotency. Linker mutant ESCs maintain the key pluripotency genes expression, but show decreased expression of self-renewal genes and increased expression of differentiation genes which result in impaired ESCs self-renewal and early embryonic lethality. Linker mutation dose not affect Oct4 genomic binding and transactivation potential, but breaks the balanced Oct4 interactome. In mutant ESCs, the interaction between Oct4 and Klf5 was decreased, but interactions between Oct4 and Cbx1, Ctr9, Cdc73 were increased which disrupt the epigenetic state of ESCs. Overexpression of Klf5 or knockdown Cbx1, Cdc73 rescue the cellular phenotype of linker mutant ESCs by rebalancing Oct4 interactome indicating that different partners interact with Oct4 competitively. Thus, by showing how Oct4 interacts with different partners, we provide novel molecular insights to explain how Oct4 contributes to the maintenance of pluripotency.
2021-12-10 | PXD017456 | Pride
Project description:Oct4 is a master regulator of pluripotency. Potential Oct4 interactors have been cataloged extensively but the manner and significance of these interactions are incompletely defined. Like other POU domain proteins, Oct4 is capable of binding to DNA in multiple configurations, however the relationship between these configurations and cofactor recruitment (and hence transcription output) are unknown. Here, we show that Oct4 interacts with common and unique proteins when bound to DNA in different configurations. One of these proteins is Jade1, a component of the HBO histone acetyltransferase complex. Jade1 preferentially associates with Oct4 when bound to More palindromic Octamer-Related Element (MORE) DNA sequences that bind Oct4 dimers and are associated with strong gene expression. We show that the Oct4 N-terminus is critical for this interaction. ChIP-seq using HBO1, the enzymatic component of the complex, identifies a preference for binding adjacent to Oct4 at MORE sites. Using purified recombinant proteins and nucleosome complexes, we show that the HBO1 complex acetylates histone H3K9 within nucleosomes more efficiently when Oct4 is co-bound to a MORE site. Histone acetylation is further increased when Oct4 is mutated to favor dimeric MORE binding. Cryo-electron microscopy reveals that Oct4 bound to a MORE near the nucleosome entry/exit site partially unwinds DNA from nucleosome core particles, and identifies additional mass associated with the HBO1 complex. These results identify a novel mechanism of transcriptional regulation by Oct4.
2024-10-18 | MSV000096131 | MassIVE
Project description:HUES24 cell line was nucleofected with POU5f1 cDNA to overexpress OCT4; This leads to the formation of mesendodermal cells Short- and Long-scales intra- and inter-chromosomal interactions are linked to gene transcription, but the molecular event underlying these structures and how it affects cell fate decision during embryonic development are poorly understood. One of the first embryonic cell fate decisions (i.e mesendoderm determination) is driven by the POU factor OCT4, acting in concert with the high mobility group genes SOX-2 and SOX-17. Here, we identify novel chromatin remodelling mechanism and enhancer function driven by both OCT4 and SALL4 that mediate cell fate switching. We found that OCT4 alters the higher-order chromatin structure at both Sox-2 and Sox-17 loci. OCT4 titrates out cohesin and switches the Sox-17 enhancer from a locked (within an inter-chromosomal Sox-2 enhancer/CTCF/cohesin loop) to an active (within an intra-chromosomal Sox-17 promoter/enhancer/cohesin loop) state. SALL4 concomitantly mobilizes the polycomb complexes at the Soxs loci. Thus, OCT4/SALL4-driven cohesin-and polycombs-mediated changes in higher order chromatin structure mediate instruction of early cell fate in embryonic cells. ChIP anti-OCT4 on chip. results_v2.xls file description: Enriched binding sites. Mutant means oct4 overexpressing cells , wt GFP nucleofected cells.
2015-04-02 | E-GEOD-58125 | biostudies-arrayexpress
Project description:Misplaced IgG expression in cancer cells has been implicated in exacerbated malignancy and poor clinical prognosis. Accumulating evidence indicate that a non-conventional sialylation modification is critical for the function of cancer-derived IgG, rendering the name sialylated cancer IgG (SIA-cIgG). However, our knowledge remains rudimentary about the regulatory mechanism that controls the expression and function of SIA-cIgG. To investigate the regulatory mechanisms of SIA-cIgG expression in lung cancer stem cells, we performed a genome-wide CRISPR activation screen in NCI-H520 cells by expressing a lentiviral library of 70,290 CRISPR-activating gRNAs targeting 23,430 genes. We investigated that the stemness-related transcriptional factors OCT4 (Gene name: POU5F1) and SOX2 were both among the top genes enriched in SIA-cIgG high cells, suggesting that OCT4 and SOX2 may serve as key factors promoting SIA-cIgG expression.
2023-03-13 | GSE222024 | GEO
Project description:HUES24 cell line was nucleofected with POU5f1 cDNA to overexpress OCT4; This leads to the formation of mesendodermal cells Short- and Long-scales intra- and inter-chromosomal interactions are linked to gene transcription, but the molecular event underlying these structures and how it affects cell fate decision during embryonic development are poorly understood. One of the first embryonic cell fate decisions (i.e mesendoderm determination) is driven by the POU factor OCT4, acting in concert with the high mobility group genes SOX-2 and SOX-17. Here, we identify novel chromatin remodelling mechanism and enhancer function driven by both OCT4 and SALL4 that mediate cell fate switching. We found that OCT4 alters the higher-order chromatin structure at both Sox-2 and Sox-17 loci. OCT4 titrates out cohesin and switches the Sox-17 enhancer from a locked (within an inter-chromosomal Sox-2 enhancer/CTCF/cohesin loop) to an active (within an intra-chromosomal Sox-17 promoter/enhancer/cohesin loop) state. SALL4 concomitantly mobilizes the polycomb complexes at the Soxs loci. Thus, OCT4/SALL4-driven cohesin-and polycombs-mediated changes in higher order chromatin structure mediate instruction of early cell fate in embryonic cells.
2015-04-02 | GSE58125 | GEO
Project description:ChIP Seq of Oct4, Nanog, H3K27me3 in Oct4+/+ and Oct4 +/- mES cells
| PRJEB1833 | ENA
Project description:Enhancer reactivation and pluripotency gene (PpG) expression could induce stemness and enhance tumorigenicity in cancer stem cells. Silencing of PpG enhancers (PpGe) during embryonic stem cell differentiation involves Lsd1–mediated H3K4me1 demethylation followed by DNA methylation. Here, we observed a widespread retention of H3K4me1 and DNA hypomethylation at PpGe associated with a partial repression of PpGs in F9 embryonal carcinoma cells (ECCs) post-differentiation. The absence of H3K4me1 demethylation could not be rescued by Lsd1 overexpression. Based on the observation that H3K4me1 demethylation is accompanied by strong Oct4 repression in P19 ECCs, we tested if Lsd1-Oct4 interaction affects Lsd1 catalytic activity. Our data show a dose-dependent inhibition of Lsd1 by Oct4 in vitro and retention of H3K4me1 at PpGe post-differentiation in Oct4 overexpressing P19 ECCs. These data suggest that Lsd1-Oct4 interaction in cancer stem cells may establish a primed enhancer state that is susceptible to reactivation leading to aberrant PpG expression.
2020-06-29 | GSE135225 | GEO