Project description:HIF-1A and HIF-2A regulate both overlapping and unique target genes in response to hypoxia. In this dataset, we identify specific HIF-1A and HIF-2A target genes in glioblastoma cells.
Project description:HIF-1A and HIF-2A regulate both overlapping and unique target genes in response to hypoxia. In this dataset, we identify specific HIF-1A and HIF-2A target genes in glioblastoma cells. 12 samples were analysed comprising 4 experimental conditions (normoxia scr, hypoxia scr, hypoxia siHIF1, hypoxia siHIF2) in triplicate. We made pairwise comparisons between the averages of each triplicate set to normoxia scr using the Partek suite.
Project description:General activation of hypoxia-inducible factor (HIF) pathways is classically associated with adverse prognosis in cancer and has been proposed to contribute to oncogenic drive. In clear cell renal carcinoma (CCRC) HIF pathways are upregulated by inactivation of the von-Hippel-Lindau tumour suppressor. However HIF-1a and HIF-2a have contrasting effects on experimental tumour progression. To better understand this paradox we examined pan-genomic patterns of HIF DNA binding and associated gene expression in response to manipulation of HIF-1a and HIF-2a and related the findings to CCRC prognosis. Our findings reveal distinct pan-genomic organization of HIF isoform-specific DNA binding at thousands of sites. Overall associations were observed between HIF-1a-specific binding, and genes associated with favourable prognosis and between HIF-2a-specific binding and adverse prognosis. However within each isoform-specific set, individual gene associations were heterogeneous in sign and magnitude, suggesting that activation of each HIF-a isoform contributes a highly complex mix of pro- and anti-tumorigenic effects ChIP and RNASeq of HIF-1a and HIF-2a transfection in 786-O cell lines
Project description:General activation of hypoxia-inducible factor (HIF) pathways is classically associated with adverse prognosis in cancer and has been proposed to contribute to oncogenic drive. In clear cell renal carcinoma (CCRC) HIF pathways are upregulated by inactivation of the von-Hippel-Lindau tumour suppressor. However HIF-1a and HIF-2a have contrasting effects on experimental tumour progression. To better understand this paradox we examined pan-genomic patterns of HIF DNA binding and associated gene expression in response to manipulation of HIF-1a and HIF-2a and related the findings to CCRC prognosis. Our findings reveal distinct pan-genomic organization of HIF isoform-specific DNA binding at thousands of sites. Overall associations were observed between HIF-1a-specific binding, and genes associated with favourable prognosis and between HIF-2a-specific binding and adverse prognosis. However within each isoform-specific set, individual gene associations were heterogeneous in sign and magnitude, suggesting that activation of each HIF-a isoform contributes a highly complex mix of pro- and anti-tumorigenic effects
Project description:To investigate the detailed molecular mechanisms for the regulatory role of HIF-1α in colon, microarray gene expression analysis was performed on colon RNA isolated from 6- to 8-week-old Hif-1α+/+, Hif-1αLSL/LSL mice. Background & Aims: The progression and growth of solid tumors leads to a state where tumors outgrow their capacity for efficient oxygenation and nutrient uptake and an increase in tumor hypoxia. Tumor hypoxic response is mediated by hypoxia-inducible factor (HIF)-1a and HIF-2a. These transcription factors regulate a battery of genes that are critical for tumor oxygenation, tumor metabolism, and cell proliferation and survival. Therefore, inhibitors of HIF have been sought for as anti-neoplastic agents in several different kinds of cancers. Interestingly, in ischemic and inflammatory diseases of the intestine, activation of HIF-1a is beneficial, and can reduce intestinal inflammation. The efficacy of pharmacological agents that chronically activate HIF-1a are decreased due to the tumorigenic potential of HIF. However, recent advance in understanding HIF signaling have identified mechanisms, which could allow for isoform specific activators. Activation of HIF-2a increases colon carcinogenesis and progression in mouse models. However, the role of chronic HIF-1a activation is unclear in the progression in colon cancer. The present data demonstrates that activation of HIF-1a in epithelial cells does not increase colon carcinogens or progression in two mouse models of colon cancer, and provides the proof of principle that HIF-1a activation maybe safe as therapies for inflammatory bowel disease. Global gene expression profiling in colon RNAs isolated from 6- to 8-week-old Hif-1α+/+ (n=5, Shah 019) and Hif-1αLSL/LSL (n=5, Shah 020).
Project description:The effects of constitutively active Hypoxia Inducible Factor (HIF) and inactivated von Hippel-Lindau tumor suppressor gene product (pVHL) were examined in a mouse model. Conditionally expressed, constitutively active HIF-1a and HIF-2a were compared with inactivated pVHL.
Project description:To investigate the detailed molecular mechanisms for the regulatory role of HIF-1α in colon, microarray gene expression analysis was performed on colon RNA isolated from 6- to 8-week-old Hif-1α+/+, Hif-1αLSL/LSL mice. Background & Aims: The progression and growth of solid tumors leads to a state where tumors outgrow their capacity for efficient oxygenation and nutrient uptake and an increase in tumor hypoxia. Tumor hypoxic response is mediated by hypoxia-inducible factor (HIF)-1a and HIF-2a. These transcription factors regulate a battery of genes that are critical for tumor oxygenation, tumor metabolism, and cell proliferation and survival. Therefore, inhibitors of HIF have been sought for as anti-neoplastic agents in several different kinds of cancers. Interestingly, in ischemic and inflammatory diseases of the intestine, activation of HIF-1a is beneficial, and can reduce intestinal inflammation. The efficacy of pharmacological agents that chronically activate HIF-1a are decreased due to the tumorigenic potential of HIF. However, recent advance in understanding HIF signaling have identified mechanisms, which could allow for isoform specific activators. Activation of HIF-2a increases colon carcinogenesis and progression in mouse models. However, the role of chronic HIF-1a activation is unclear in the progression in colon cancer. The present data demonstrates that activation of HIF-1a in epithelial cells does not increase colon carcinogens or progression in two mouse models of colon cancer, and provides the proof of principle that HIF-1a activation maybe safe as therapies for inflammatory bowel disease.
Project description:Hypoxia inducible factor (HIF) is the major transcriptional regulator of cellular responses to hypoxia. The two principal HIF-a isoforms, HIF-1a and HIF-2a, are progressively stabilized in response to hypoxia and form heterodimers with HIF-1b to activate a broad range of transcriptional responses. Here we report on the pan-genomic distribution of isoform-specific HIF binding in response to hypoxia of varying severity and duration, and in response to genetic ablation of each HIF-a isoform. Our findings reveal that, despite an identical consensus recognition sequence in DNA, each HIF heterodimer loads progressively at a distinct repertoire of cell-type specific sites across the genome, with little evidence of redistribution under any of the conditions examined. Marked biases towards promoter proximal binding of HIF-1 and promoter distant binding of HIF-2 were observed under all conditions and were consistent in multiple cell type. The findings imply that each HIF isoform has an inherent property that determines its binding distribution across the genome, which might be exploited to therapeutically target the specific transcriptional output of each isoform independently.
Project description:Hypoxia inducible factor (HIF) is the major transcriptional regulator of cellular responses to hypoxia. The two principal HIF-a isoforms, HIF-1a and HIF-2a, are progressively stabilized in response to hypoxia and form heterodimers with HIF-1b to activate a broad range of transcriptional responses. Here we report on the pan-genomic distribution of isoform-specific HIF binding in response to hypoxia of varying severity and duration, and in response to genetic ablation of each HIF-a isoform. Our findings reveal that, despite an identical consensus recognition sequence in DNA, each HIF heterodimer loads progressively at a distinct repertoire of cell-type specific sites across the genome, with little evidence of redistribution under any of the conditions examined. Marked biases towards promoter proximal binding of HIF-1 and promoter distant binding of HIF-2 were observed under all conditions and were consistent in multiple cell type. The findings imply that each HIF isoform has an inherent property that determines its binding distribution across the genome, which might be exploited to therapeutically target the specific transcriptional output of each isoform independently.
Project description:HIF-1a and HIF-2a are expressed at high levels in mesenchymal progenitors compared to more committed mesenchymal cells and hematopoietic cells. HIF-factors could therefore have a role in the regulation the biology of mesenchymal progenitors and their functions, like the non cell-autonomous maintenance of hematopoietic progenitors. We used microarrays to detail the global program of gene expression regulated by HIF-1a or HIF-2a in mesenchymal progenitors Mesenchymal progenitors were FACS-sorted and cultured in low oxygen concentration for few days. Once cells started to form CFU-F colonies, we transduced them with shRNAs targeting specifically HIF-1a or HIF-2a. Four days after transduction, cells were collected and RNA extracted for microarray analysis.