Polyamides alleviate transcription inhibition associated with long GAA•TTC repeats in Friedreich’s ataxia
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ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE5040 | GEO | 2006/06/14
SECONDARY ACCESSION(S): PRJNA96673
REPOSITORIES: GEO
Similar Datasets
Project description:Lymphoblast cells from a patient with Freidriech's Ataxia were incubated with pyrrole-imidazole polyamides targeted to the GAA triplet repeat in the intron 1. The polyamides were shown in cell culture to increase levels of endogenous frataxin mRNA. A normal sibling derived lymphoblast cell line was used as a control. Experiment Overall Design: Normal (GM15851) and patient (GM15850) cell lines were incubated in the presence of match polyamide FA1 at 1uM, 2uM or mismatch polyamide FA2 at 2uM for 7days prior to RNA purification and microarray analysis.
2008-06-13 | E-GEOD-5040 | biostudies-arrayexpress
Project description:The inherited neurodegenerative disease Friedreich’s ataxia (FRDA) is caused by hyperexpansion of GAA•TTC trinucleotide repeats within the first intron of the FXN gene, encoding the mitochondrial protein frataxin. Long GAA•TTC repeats causes heterochromatin-mediated silencing and loss of frataxin in affected individuals. We report the derivation of induced pluripotent stem cells (iPSCs) from FRDA patient fibroblasts through retroviral transduction of transcription factors. FXN gene repression is maintained in the iPSCs, as are the mRNA and miRNA global expression signatures reflecting the human disease. GAA•TTC repeats uniquely in FXN in the iPSCs exhibit repeat instability similar to patient families, where they expand and/or contract with discrete changes in length between generations. The mismatch repair enzyme Msh2, implicated in repeat instability in other triplet repeat diseases, is highly expressed in the iPSCs, occupies FXN intron 1, and shRNA silencing of Msh2 impedes repeat expansion, providing a possible molecular explanation for repeat expansion in FRDA.
2010-07-02 | GSE22651 | GEO
Project description:Pyrrole-imidazole polyamides (PIPs) have been shown to inhibit gene expression by interrupting the DNA-protein interface. Human Ectopic viral integration site 1 (EVI1) is an oncogenic transcription factor which plays a key role in many aggressive forms of cancer. We have developed a novel pyrrole–imidazole polyamide, PIP1 targeting the REL/ELK1 binding site in the EVI1 minimal promoter that can significantly repress the expression of EVI1 in MDA-MB-231 cells. Whole-transcriptome analysis revealed that a fraction of EVI1-driven genes were modulated by PIP1.
2014-07-28 | GSE59502 | GEO
Project description:Pyrrole-imidazole polyamides are versatile DNA minor groove binders and attractive therapeutic options against oncological targets, especially upon functionalization with an alkylating agent such as endo-seco-CBI. These molecules also provide an alternative for oncogenes deemed “undruggable” at the protein level, where the absence of solvent-accessible pockets or structural crevices prevent the formation of protein-inhibitor ligands; nevertheless, the genome-wide effect of pyrrole-imidazole polyamide binding remain largely unclear to-date. Here we propose a next-generation sequencing-based workflow combined with whole genome expression arrays to address such issue using a candidate anti-cancer alkylating agent, KR12, against codon 12 mutant KRAS. Biotinylating KR12 enables the means to identify its genome-wide effects in living cells and possible biological implications via a coupled workflow of enrichment-based sequencing and expression microarrays. The subsequent computational pathway and expression analyses allow the identification of its genomic binding sites, as well as a route to explore a polyamide’s possible genome-wide effects. Among the 3,343 KR12 binding sites identified in the human LS180 colorectal cancer genome, the reduction of KR12-bound gene expressions was also observed. Additionally, the coupled microarray-sequencing analysis also revealed some insights about the effect of local chromatin structure on pyrrole-imidazole polyamide, which had not been fully understood to-date. A comparative analysis with KR12 in a different human colorectal cancer genome SW480 also showed agreeable agreements of KR12 binding affecting gene expressions. Combination of these analyses thus suggested the possibility of applying this approach to other pyrrole-imidazole polyamides to reveal further biological details about the effect of polyamide binding in a genome.
2016-11-01 | GSE86598 | GEO
Project description:Pyrrole-imidazole polyamides are versatile DNA minor groove binders and attractive therapeutic options against oncological targets, especially upon functionalization with an alkylating agent such as endo-seco-CBI. These molecules also provide an alternative for oncogenes deemed “undruggable” at the protein level, where the absence of solvent-accessible pockets or structural crevices prevent the formation of protein-inhibitor ligands; nevertheless, the genome-wide effect of pyrrole-imidazole polyamide binding remain largely unclear to-date. Here we propose a next-generation sequencing-based workflow combined with whole genome expression arrays to address such issue using a candidate anti-cancer alkylating agent, KR12, against codon 12 mutant KRAS. Biotinylating KR12 enables the means to identify its genome-wide effects in living cells and possible biological implications via a coupled workflow of enrichment-based sequencing and expression microarrays. The subsequent computational pathway and expression analyses allow the identification of its genomic binding sites, as well as a route to explore a polyamide’s possible genome-wide effects. Among the 3,343 KR12 binding sites identified in the human LS180 colorectal cancer genome, the reduction of KR12-bound gene expressions was also observed. Additionally, the coupled microarray-sequencing analysis also revealed some insights about the effect of local chromatin structure on pyrrole-imidazole polyamide, which had not been fully understood to-date. A comparative analysis with KR12 in a different human colorectal cancer genome SW480 also showed agreeable agreements of KR12 binding affecting gene expressions. Combination of these analyses thus suggested the possibility of applying this approach to other pyrrole-imidazole polyamides to reveal further biological details about the effect of polyamide binding in a genome.
2016-11-01 | GSE86597 | GEO
Project description:Glioblastoma is the most common adult brain tumour, representing a high degree of malignancy. It is reported that transcription factors are involved in the malignancy of glioblastoma , and RUNX1 is one of them. A novel gene switch-off agent, Chb-M', which is alkylating agent-conjugated pyrrole-imidazole polyamides, designed to fit the RUNX1 DNA groove, inhibits transcription of RUNX1. We We examined changes in the expression of downstream genes due to transcriptional inhibition of this agent.
2021-05-19 | GSE174634 | GEO
Project description:Transcription profiling by array of human lymphoblast cells from a patient with Freidriech's ataxia after treatment with pyrrole-imidazole polyamides
2014-08-15 | E-GEOD-5040 | ExpressionAtlas
Project description:Pyrrole-imidazole polyamides (PIPs) have been shown to inhibit gene expression by interrupting the DNA-protein interface. Human Ectopic viral integration site 1 (EVI1) is an oncogenic transcription factor which plays a key role in many aggressive forms of cancer. We have developed a novel pyrroleM-bM-^@M-^Simidazole polyamide, PIP1 targeting the REL/ELK1 binding site in the EVI1 minimal promoter that can significantly repress the expression of EVI1 in MDA-MB-231 cells. Whole-transcriptome analysis revealed that a fraction of EVI1-driven genes were modulated by PIP1. Global expression changes in MDA-MB-231 cells were evaluated after treating the cells with PIP1 and DMSO for 48 hours. The vehicle DMSO is used as a negative control. Each condition is performed in technical replicates.
2014-07-28 | E-GEOD-59502 | biostudies-arrayexpress
Project description:Background: Friedreich ataxia, an autosomal recessive neurodegenerative and cardiac disease, is caused by abnormally low levels of frataxin, an essential mitochondrial protein. All Friedreich ataxia patients carry a GAA/TTC repeat expansion in the first intron of the frataxin gene, either in the homozygous state or in compound heterozygosity with other loss-of-function mutations. The GAA expansion inhibits frataxin expression through a heterochromatin-mediated repression mechanism. Histone modifications that are characteristic of silenced genes in heterochromatic regions occur at expanded alleles in cells from Friedreich ataxia patients, including increased trimethylation of histone H3 at lysine 9 and hypoacetylation of histones H3 and H4. Methodology/Principal Findings: By chromatin immunoprecipitation, we detected the same heterochromatin marks in homozygous mice carrying a (GAA)230 repeat in the first intron of the mouse frataxin gene (KIKI mice). These animals have decreased frataxin levels and, by microarray analysis, show significant gene expression changes in several tissues. We treated KIKI mice with a novel histone deacetylase inhibitor, compound 106, which substantially increases frataxin mRNA levels in cells from Friedreich ataxia individuals. Treatment increased histone H3 and H4 acetylation in chromatin near the GAA repeat and restored wild-type frataxin levels in the nervous system and heart, as determined by quantitative RT-PCR and semiquantitative western blot analysis. No toxicity was observed. Furthermore, most of the differentially expressed genes in KIKI mice reverted towards wild-type levels. Conclusions/Significance: Lack of acute toxicity, normalization of frataxin levels and of the transcription profile changes resulting from frataxin deficiency provide strong support to a possible efficacy of this or related compounds in reverting the pathological process in Friedreich ataxia, a so far incurable neurodegenerative disease. Keywords: drug response
2008-03-08 | GSE10745 | GEO
Project description:Regulating desired loci in the genome with sequence-specific DNA-binding molecules is a major goal for the development of precision medicine. Pyrrole–imidazole (Py–Im) polyamides are synthetic molecules that can be rationally de-signed to target specific DNA sequences to both disrupt and recruit transcriptional machinery. While in vitro binding has been extensively studied, in vivo effects are often difficult to predict using current models of binding energetics. Determining the impact of genomic architecture and the local chromatin landscape on polyamide-DNA sequence specificity remains an unresolved question that impedes their utility in vivo. In this report we directly identified polyamide–DNA interaction sites across the entire genome, by covalent crosslinking and capturing these events in the nuclei of human LNCaP cells. This method, termed COSMIC-seq, confirms the ability of hairpin-polyamides, with similar architectures but differing at a single ring position, to retain in vitro specificities and display distinct genome-wide binding profiles. These results underpin the development of Py-Im polyamides as DNA-targeting molecules and the potential for utility as synthetic transcription factors (Syn-TFs) capable of functioning in concert with the cellular regulatory circuitry.
2020-12-02 | GSE149367 | GEO