Project description:Purpose: We aimed to investigate in depth the regulation of microRNA expression by hypoxia in the breast cancer cell line MCF-7, establish the relationship between microRNA expression and HIF binding sites, pri-miRNA transcription and microRNA processing gene expression. Methods: microRNA sequencing data and gene expression microarray data were generated from MCF-7 cells submitted to an hypoxia timecourse (16h, 32h and 48h at 1% Oxygen). Data was integrated to 500 published high-stringency HIF binding sites identified in MCF-7 cells. Results: We identified 41 microRNAs significantly up- and 28 down- regulated, of which 38 mature and 20 star forms are reported in conjunction with hypoxia for the first time. HIF-1M-NM-1 and HIF-2M-NM-1 binding sites within 50kb distance of microRNA loci were found by integration of HIF ChIP-seq data, showing overall association between binding sites and up-regulation. Gene expression profiling analysis showed no full coordination between pri-miRNA and microRNA expression, pointing towards additional levels of regulation. Several transcripts playing a role in microRNA processing were found regulated by hypoxia, of which two were HIF dependent. Conclusions: The data support the hypothesis that microRNA expression under hypoxia is regulated at transcriptional and post-transcriptional level. HIF is involved at both levels, regulating the transcription of certain microRNAs and also the expression of key elements of the microRNA processing pathway. microRNA-seq profiles of MCF-7 exposed to hypoxia (1% Oxygen) for 16h (2 replicates), 32h (2 replicates) and 48h (2 replicates) and to normoxia (2 replicates) were generated using Illumina sequencing platform.
Project description:Purpose: We aimed to investigate in depth the regulation of microRNA expression by hypoxia in the breast cancer cell line MCF-7, establish the relationship between microRNA expression and HIF binding sites, pri-miRNA transcription and microRNA processing gene expression. Methods: microRNA sequencing data and gene expression microarray data were generated from MCF-7 cells submitted to an hypoxia timecourse (16h, 32h and 48h at 1% Oxygen). Data was integrated to 500 published high-stringency HIF binding sites identified in MCF-7 cells. Results: We identified 41 microRNAs significantly up- and 28 down- regulated, of which 38 mature and 20 star forms are reported in conjunction with hypoxia for the first time. HIF-1M-NM-1 and HIF-2M-NM-1 binding sites within 50kb distance of microRNA loci were found by integration of HIF ChIP-seq data, showing overall association between binding sites and up-regulation. Gene expression profiling analysis showed no full coordination between pri-miRNA and microRNA expression, pointing towards additional levels of regulation. Several transcripts playing a role in microRNA processing were found regulated by hypoxia, of which two were HIF dependent. Conclusions: The data support the hypothesis that microRNA expression under hypoxia is regulated at transcriptional and post-transcriptional level. HIF is involved at both levels, regulating the transcription of certain microRNAs and also the expression of key elements of the microRNA processing pathway. MicroRNA expression profiles of MCF-7 exposed to hypoxia (1% Oxygen) for 16h (2 replicates), 32h (3 replicates) and 48h (3 replicates) and to normoxia (3 replicates) were generated using Agilent miRNA microarrays. This data was used to validate the microRNA-seq data included in this study.
Project description:Purpose: We aimed to investigate in depth the regulation of microRNA expression by hypoxia in the breast cancer cell line MCF-7, establish the relationship between microRNA expression and HIF binding sites, pri-miRNA transcription and microRNA processing gene expression. Methods: microRNA sequencing data and gene expression microarray data were generated from MCF-7 cells submitted to an hypoxia timecourse (16h, 32h and 48h at 1% Oxygen). Data was integrated to 500 published high-stringency HIF binding sites identified in MCF-7 cells. Results: We identified 41 microRNAs significantly up- and 28 down- regulated, of which 38 mature and 20 star forms are reported in conjunction with hypoxia for the first time. HIF-1? and HIF-2? binding sites within 50kb distance of microRNA loci were found by integration of HIF ChIP-seq data, showing overall association between binding sites and up-regulation. Gene expression profiling analysis showed no full coordination between pri-miRNA and microRNA expression, pointing towards additional levels of regulation. Several transcripts playing a role in microRNA processing were found regulated by hypoxia, of which two were HIF dependent. Conclusions: The data support the hypothesis that microRNA expression under hypoxia is regulated at transcriptional and post-transcriptional level. HIF is involved at both levels, regulating the transcription of certain microRNAs and also the expression of key elements of the microRNA processing pathway. Gene expression profiles of MCF-7 exposed to hypoxia (1% Oxygen) for 16h (3 replicates), 32h (3 replicates) and 48h (3 replicates) and to normoxia (3 replicates) were generated using Illumina microarrays.
Project description:We performed HIF-1alpha ChIP-seq in K562 cells cultured in normoxia vs. hypoxia for 3 days. We identified two new HIF binding sites in TET3 intron 2 that control TET3 expression in hypoxia
Project description:We performed HIF-1alpha ChIP-seq in SK-N-BE(2) cells cultured in normoxia vs. hypoxia for 48 hrs. We identified two new HIF-1alpha binding sites in TET1 that control TET1expression in hypoxia
Project description:Adaptation to hypoxia is mediated through a coordinated transcriptional response driven largely by Hypoxia-Inducible Factor 1 (HIF-1). The direct transcriptional targets of HIF-1 play important roles in facilitating both short-term and long-term adaptation to hypoxia. Alignment of the sequences encompassing all well-characterized HIF-1 binding sites has revealed a consensus core HRE motif of 5'-RCGTG-3' (R = A or G). Since the consensus HIF-1 binding motif is too promiscuous to accurately predict binding a priori, we used ChIP-chip to define HIF-1 chromatin binding on a genome-wide level. We integrated these results with gene expression profiling to interrogate mechanisms regulating hypoxia-induced gene expression, and to more comprehensively identify direct targets of HIF-1 transactivation.
Project description:Total 23 samples were derived from [1] HUVEC treated in the absence (0h) or presence of hypoxia (1, 2, 4, 8, 12, and 24 hrs) to determine hypoxia-regulated gene in endothelial cells, [2] control siRNA or HIF1? siRNA transfected HUVEC cells treated in the absence or presence of hypoxia, [3] control siRNA or KDM3A siRNA transfected HUVEC cells treated in the absence or presence of hypoxia, [4] ChIP-seq data for HIF1 binding sites and histone modifications under normoxia and hypoxia in endothelial cells. This study represents 15 Samples from the gene expression part of the study described in 1,2, and 3 above. The submitter has not provided the ChIP-seq data to GEO.