Homo sapiens
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PROVIDER: PRJNA108619 | ENA |
REPOSITORIES: ENA
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Project description:Abstract The interplay between histone modifications and promoter hypermethylation provides a causative explanation for epigenetic gene silencing in cancer. Less is known about the upstream initiators that direct this process. Here, we report that the Cystatin M (CST6) tumor suppressor gene is concurrently down-regulated with other loci in breast epithelial cells co-cultured with cancer-associated fibroblasts (CAFs). Promoter hypermethylation of CST6 is associated with aberrant AKT1 activation in epithelial cells, as well as the disabled INNP4B regulator resulted from the suppression by CAFs. Repressive chromatin, marked by trimethyl-H3K27 and dimethyl-H3K9, and de novo DNA methylation is established at the promoter. The findings suggest that microenvironmental stimuli are triggers in this epigenetic cascade, leading to the long-term silencing of CST6 in breast tumors. Our present findings implicate a causal mechanism defining how tumor stromal fibroblasts support neoplastic progression by manipulating the epigenome of mammary epithelial cells. The result also highlights the importance of direct cell-cell contract between epithelial cells and the surrounding fibroblasts that confer this epigenetic perturbation. Since this two-way interaction is anticipated, the described co-culture system can be used to determine the effect of epithelial factors on fibroblasts in future studies.
2008-12-01 | GSE10046 | GEO
Project description:Epithelial-mesenchymal transition (EMT) is a reversible transcriptional program subverted by cancer cells to drive cancer progression. Transcription factor ZEB1 is a master regulator of EMT, driving disease recurrence in poor outcome triple negative breast cancer (TNBC). Here, we silence ZEB1 in TNBC models by CRISPR-mediated epigenetic editing, resulting in nearly complete repression of ZEB1 in vivo, accompanied by long-lasting tumor inhibition. Integrated transcriptomic and epigenetic profiling identified a ZEB1-dependent gene-signature associated with transcriptional up-regulation, promoter DNA demethylation and enhanced chromatin accessibility in core cell adhesion loci, demonstrating epigenetic reprogramming towards a more epithelial state. Epigenetic shifts induced by ZEB1-silencing are enriched in a subset of human breast tumors, illuminating a clinically-relevant hybrid-like state. Thus, the synthetic epi-silencing of ZEB1 induces stable “lock-in” epigenetic reprogramming of mesenchymal tumors associated with a distinct epigenetic landscape. We outline approaches to stably reprogram EMT for targeting poor outcome breast cancers driven by oncogenic transcription factors.
2023-04-17 | GSE210276 | GEO
Project description:Epithelial-mesenchymal transition (EMT) is a reversible transcriptional program subverted by cancer cells to drive cancer progression. Transcription factor ZEB1 is a master regulator of EMT, driving disease recurrence in poor outcome triple negative breast cancer (TNBC). Here, we silence ZEB1 in TNBC models by CRISPR-mediated epigenetic editing, resulting in nearly complete repression of ZEB1 in vivo, accompanied by long-lasting tumor inhibition. Integrated transcriptomic and epigenetic profiling identified a ZEB1-dependent gene-signature associated with transcriptional up-regulation, promoter DNA demethylation and enhanced chromatin accessibility in core cell adhesion loci, demonstrating epigenetic reprogramming towards a more epithelial state. Epigenetic shifts induced by ZEB1-silencing are enriched in a subset of human breast tumors, illuminating a clinically-relevant hybrid-like state. Thus, the synthetic epi-silencing of ZEB1 induces stable “lock-in” epigenetic reprogramming of mesenchymal tumors associated with a distinct epigenetic landscape. We outline approaches to stably reprogram EMT for targeting poor outcome breast cancers driven by oncogenic transcription factors.
2023-04-17 | GSE210275 | GEO
Project description:Epithelial-mesenchymal transition (EMT) is a reversible transcriptional program subverted by cancer cells to drive cancer progression. Transcription factor ZEB1 is a master regulator of EMT, driving disease recurrence in poor outcome triple negative breast cancer (TNBC). Here, we silence ZEB1 in TNBC models by CRISPR-mediated epigenetic editing, resulting in nearly complete repression of ZEB1 in vivo, accompanied by long-lasting tumor inhibition. Integrated transcriptomic and epigenetic profiling identified a ZEB1-dependent gene-signature associated with transcriptional up-regulation, promoter DNA demethylation and enhanced chromatin accessibility in core cell adhesion loci, demonstrating epigenetic reprogramming towards a more epithelial state. Epigenetic shifts induced by ZEB1-silencing are enriched in a subset of human breast tumors, illuminating a clinically-relevant hybrid-like state. Thus, the synthetic epi-silencing of ZEB1 induces stable “lock-in” epigenetic reprogramming of mesenchymal tumors associated with a distinct epigenetic landscape. We outline approaches to stably reprogram EMT for targeting poor outcome breast cancers driven by oncogenic transcription factors.
2023-04-17 | GSE210274 | GEO
Project description:BRMS1L (breast cancer metastasis suppressor 1 likeM-oM-<M-^LBRMS1-like) is a component of the SIN3A-HDAC corepressor complex that suppresses target gene transcription. Here, we show that reduced BRMS1L in breast cancer tissues is associated with tumor metastasis and poor patient survival. Functionally, BRMS1L inhibits migration and invasion of breast cancer cells by inhibiting epithelial-mesenchymal transition (EMT). These effects are mediated by epigenetic silencing of FZD10, a receptor for Wnt signaling, by facilitating the recruitment of HDAC1 to its promoter and enhancing histone H3K9 deacetylation. Consequently, BRMS1L-induced FZD10 silencing inhibits aberrant activation of WNT3-FZD10-M-oM-^AM-"-catenin signaling. Furthermore, BRMS1L is a target of miR-106b and miR-106b upregulation leads to BRMS1L reduction in breast cancer cells. RNAi-mediated silencing of BRMS1L expression promotes metastasis of breast cancer xenografts in immunocompromised mice, while ectopic BRMS1L expression inhibits metastasis. Therefore, BRMS1L provides an epigenetic regulation of Wnt signaling in breast cancer cells and acts as a breast cancer metastasis suppressor. Ther transfection analysis used here were further desxribed in Chang Gong, eta al.2013. miR-106b expression determines the proliferation paradox of TGF-M-NM-2 in breast cancer cells. Oncogene. 2013 A two chip study using total RNA recovered from MDA-MB-231 breast cancer cells transfected with negative control vector or vector overexpressing BRMS1L for 24 hours. Each chip measures the expression 45033 genes were collected from the authoritative data source including NCBI.
2014-09-12 | E-GEOD-61354 | biostudies-arrayexpress
Project description:BRMS1L (breast cancer metastasis suppressor 1 like，BRMS1-like) is a component of the SIN3A-HDAC corepressor complex that suppresses target gene transcription. Here, we show that reduced BRMS1L in breast cancer tissues is associated with tumor metastasis and poor patient survival. Functionally, BRMS1L inhibits migration and invasion of breast cancer cells by inhibiting epithelial-mesenchymal transition (EMT). These effects are mediated by epigenetic silencing of FZD10, a receptor for Wnt signaling, by facilitating the recruitment of HDAC1 to its promoter and enhancing histone H3K9 deacetylation. Consequently, BRMS1L-induced FZD10 silencing inhibits aberrant activation of WNT3-FZD10--catenin signaling. Furthermore, BRMS1L is a target of miR-106b and miR-106b upregulation leads to BRMS1L reduction in breast cancer cells. RNAi-mediated silencing of BRMS1L expression promotes metastasis of breast cancer xenografts in immunocompromised mice, while ectopic BRMS1L expression inhibits metastasis. Therefore, BRMS1L provides an epigenetic regulation of Wnt signaling in breast cancer cells and acts as a breast cancer metastasis suppressor. Ther transfection analysis used here were further desxribed in Chang Gong, eta al.2013. miR-106b expression determines the proliferation paradox of TGF-β in breast cancer cells. Oncogene. 2013
2014-09-12 | GSE61354 | GEO
Project description:AKT1 E17K, occurring at low frequency in a broad range of cancer types, is a gain-of-function mutation that constitutively activates the PI3K-AKT pathway. However, how AKT1E17K is regulated in cancer pathogenesis remains elusive. Here, we interrogate the AKT1E17K-interacting lncRNAs and identify that SVIL-AS1 preferentially binds to AKT1E17K rather than AKT1WT proteins. We find that SVIL-AS1 enhances AKT1 phosphorylation and downstream signaling. SVIL-AS1 knockdown dramatically inhibits the growth of AKT1E17K cells in intro and in vivo. Notably, AKT1 and SVIL-AS1 interaction is AKT1 phosphorylation-dependent. SVIL-AS1 also interacts with PPP2R2A, a subunit of phosphatase PP2A holoenzyme, and blocks the binding of PPP2R2A to AKT1E17K to prevent AKT1 dephosphorylation. Moreover, AKT1E17K cells are not effectively inhibited by the allosteric AKT inhibitor, whereas silencing SVIL-AS1 sensitizes AKT1E17K cells to AKT1 allosteric inhibitor, as well as the PI3K inhibitor. In breast cancer tissues, SVIL-AS1 is highly expressed and associated with p-AKT1 level and poor prognosis of patients. Together, our findings highlight a previously unappreciated role of lncRNA SVIL-AS1 in regulating AKT1 dephosphorylation, which serves as a promising therapeutic target for AKT1E17K tumors.
2025-05-30 | GSE268685 | GEO
Project description:Epithelial to Mesenchymal Transition (EMT) renders epithelial cells to acquire migratory characteristics during development and cancer metastasis. While epigenetic and splicing changes have been implicated in EMT, the mechanisms governing their crosstalk remain poorly understood. Here, we identify C2H2 zinc finger protein, ZNF827, a novel factor, is strongly induced during important EMT mediated processes including in brain development and breast cancer metastasis and is required for the molecular and phenotypic changes underlying EMT in these processes. Mechanistically, ZNF827 mediated these responses by orchestrating a large-scale remodeling of the splicing landscape by recruiting HDAC1 for epigenetic modulation of distinct genomic loci, thereby slowing RNA Pol II progression and altering the splicing of transcripts encoding key EMT regulators in cis. These findings reveal an unprecedented complexity between epigenetic landscape and splicing and identifies ZNF827 as a master regulator coupling these processes during EMT in brain development and breast cancer metastasis.
2022-06-21 | PXD034511 | Pride
Project description:Background: PIK3CA mutations are observed in >30% of breast cancers, which are more common in estrogen receptor (ERα)-positive breast cancer compared with ERα-negative breast cancer. AKT1, 2, and 3 isoforms, major isoforms downstream of PI3K, modulate ERα activity. It is unknown whether PIK3CA mutation leads to preferential activation of specific AKT isoforms with an ability to modulate ERα function. Methods: Gene expression arrays were performed on parental, AKT1 knockdown or AKT2 knockdown MCF-7 breast cancer cells with or without estradiol treatment for three hours. Results: AKT1 had a dominant role in ERα:estradiol-dependent gene expression and proliferation. We have identified a unique gene expression signature that is dependent on ERα, estradiol, AKT1 and the pioneer factor FOXA1. Overexpression of this signature was associated with better outcome in patients with ERα-positive breast cancer. In contrast, AKT2 controlled global gene expression.
2016-08-10 | GSE60759 | GEO
Project description:Loss of H3K27me3 repressive chromatin histone marks, maintained by the histone methyltransferase (HKMT) EZH2, may lead to reversal of epigenetic silencing in tumor cells and have therapeutic potential. Using a cell-based assay, we have identified three compounds from a HKMT inhibitor chemical library which re-express H3K27me3 mediated, silenced genes. Chromatin immunoprecipitation verified a decrease in silencing marks (H3K27me3, H3K9me3) and importantly an increase in active marks (H3K4me2/3, H3K27ac) at the promoter of re-expressed genes. Compound treated breast tumor cells induced enrichment for genome-wide changes in expression of known target genes for EZH2 and induced cell growth inhibition: with most sensitive breast tumor cell lines having low EZH2 protein expression, while a normal epithelial breast line was least sensitive.
2013-08-27 | GSE36131 | GEO