Unknown,Transcriptomics,Genomics,Proteomics

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Genome-wide analysis of the RNA polyemerase I trascription factor UBF1/2 binding in mouse and human cell lines.

ABSTRACT: We report ChIP-Seq analysis of the RNA polyemerase I trascription factor UBF1/2 in NIH3T3, HMEC and HMLER cell lines. NIH3T3* samples: We correlated UBF1/2 binding across the genome with that of RNA polemerase I (Pol I), RNA polemerase II (Pol II) and chromatin states in NIH3T3 cells We perfromed ChIP-seq of UBF1/2 (2 biological replicates), Pol I (POLR1A/RPA194), Pol II, H3K9me3, H3K4Me3, H3K9ac, H4 hyperacetylation and genomic DNA input as reference. HMEC* samples: We report ChIP-Seq analysis of UBF1/2 and Pol I (POLR1A/RPA194) in human mammary epithelial cells (HMEC). In addition we include UBF1/2 ChIP-seq in the tumourigenic epithelial cell line HMLER. In this study, we compared UBF1/2 binding in HMEC to UBF1/2 binding in in the tumorigenic HMLER cells, an isogenic HMEC-derived cell line expressing the SV40 large-T, TERT, and an oncogenic allele of the HRAS gene (expressing HRASV12G) that forms tumors in nude mice (Elenbaas et al., Gene & Development 2001) We sequenced UBF1/2 ChIP and Pol I(POLR1A/RPA194) ChIP and gDNA input from HMEC. We sequenced UBF1/2 ChIP and gDNA input from HMLER

ORGANISM(S): Mus musculus

SUBMITTER: Elaine Sanij

PROVIDER: E-GEOD-63255 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress

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Project description:Dysregulation of the epigenome is a common event in malignancy. However, deciphering the earliest cancer associated epigenetic events remains a challenge. Cancer epigenome studies to date have primarily utilised cancer cell lines or clinical samples, where it is difficult to identify the initial epigenetic lesions from those that occur over time. Here, we analysed the epigenome of normal Human Mammary Epithelial Cells (HMEC) and a matched variant cell population (vHMEC) that has escaped senescence and undergone partial carcinogenic transformation. Using this model system we sought to identify the earliest epigenetic changes that potentially occur during carcinogenesis. First we show that the transcriptome of vHMEC resembles that of basal-like breast cancer. Moreover, in vHMEC there is significant deregulation of MYC, p53, EZH2/polycomb, the Aryl Hydrocarbon Receptor (AHR) and miRNAs-143, 145, 199a and 519a at the transcriptional level. Second, we find that vHMEC exhibit genome-wide changes in DNA methylation affecting key cancer-associated pathways. Hypermethylation predominately impacted gene promoters (particularly those targeted by AHR and TP53) and polycomb associated loci, whereas hypomethylation frequently affected enhancers. Next we show that long range epigenetic deregulation occurred in vHMEC involving concordant change in chromatin modification and gene expression across ~0.5-1Mb regions. Finally, we demonstrate that the DNA methylation changes we observe in vHMECs, occur in basal-like breast cancer (notably FOXA1 hypermethylation).. Overall our results suggest that the first steps of carcinogenesis are associated with a co-ordinated deregulation of DNA methylation and chromatin modification spanning a range of genomic loci potentially targeted by key transcription factors and a corresponding deregulation of transcriptional networks. H3K27me3 ChIP-chip was performed on HMEC and vHMEC from 4 donors, H3K9ac was performed on cells from 2 donors. Both H3K27me3 and H3K9ac ChIP was performed on two time points for vHMEC and used the same input materia.

Project description:Dysregulation of the epigenome is a common event in malignancy. However, deciphering the earliest cancer associated epigenetic events remains a challenge. Cancer epigenome studies to date have primarily utilised cancer cell lines or clinical samples, where it is difficult to identify the initial epigenetic lesions from those that occur over time. Here, we analysed the epigenome of normal Human Mammary Epithelial Cells (HMEC) and a matched variant cell population (vHMEC) that has escaped senescence and undergone partial carcinogenic transformation. Using this model system we sought to identify the earliest epigenetic changes that potentially occur during carcinogenesis. First we show that the transcriptome of vHMEC resembles that of basal-like breast cancer. Moreover, in vHMEC there is significant deregulation of MYC, p53, EZH2/polycomb, the Aryl Hydrocarbon Receptor (AHR) and miRNAs-143, 145, 199a and 519a at the transcriptional level. Second, we find that vHMEC exhibit genome-wide changes in DNA methylation affecting key cancer-associated pathways. Hypermethylation predominately impacted gene promoters (particularly those targeted by AHR and TP53) and polycomb associated loci, whereas hypomethylation frequently affected enhancers. Next we show that long range epigenetic deregulation occurred in vHMEC involving concordant change in chromatin modification and gene expression across ~0.5-1Mb regions. Finally, we demonstrate that the DNA methylation changes we observe in vHMECs, occur in basal-like breast cancer (notably FOXA1 hypermethylation).. Overall our results suggest that the first steps of carcinogenesis are associated with a co-ordinated deregulation of DNA methylation and chromatin modification spanning a range of genomic loci potentially targeted by key transcription factors and a corresponding deregulation of transcriptional networks. We sought to study the chromatin modification profile of human mammary epithelial cells (HMEC) and a matched isogenic variant population (vHMEC) utilising ChIP-seq. ChIP was performed against H3K27ac, H3K36me3 and H3K27me3 for a HMEC and vHMEC timpoint in one donor. H3K4me3 CHIP was performed in two donors, which were treated as biological replicates.

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Genome-wide analysis of the RNA polyemerase I trascription factor UBF1/2 binding in mouse and human cell lines.

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