Effect of HIF-1alpha and HIF-2alpha on hypoxic response in Panc1 cells
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ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE319526 | GEO | 2026/02/18
REPOSITORIES: GEO
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Project description:Effect of HIF-1alpha and HIF-2alpha on hypoxic response in Panc1 cells
| PRJNA1423676 | ENA
Project description:Intestinal epithelia exist in a uniquely dynamic oxygen tension microenvironment. Adaptive responses to hypoxia in mammalian cells are regulated largely by hypoxia inducible factor (HIF) transcriptional complexes. Functional HIF exists as an obligate alpha/beta heterodimer, comprising both a constitutive subunit (HIF-1beta), and an oxygen-labile regulatory (alpha) component. To date, three regulatory subunits have been identified, namely HIF-1alpha, HIF-2alpha, and HIF-3alpha, with the highest level of sequence homology conserved between HIF-1alpha and HIF-2alpha. Despite their concurrent expression in intestinal epithelial cells, HIF-1 and HIF-2 play non-redundant roles in the regulation of an overlapping but distinct set of gene targets. In this study, we performed ChIP-on-chip analysis of chromatin isolated from hypoxic intestinal epithelia to delineate HIF-1 and HIF-2 specific loci. Comparison of HIF-1alpha ChIP-chip and HIF-2alpha ChIP-chip to map HIF-1- and HIF-2-specific gene targets across the genome.
2013-11-05 | E-GEOD-43108 | biostudies-arrayexpress
Project description:Intestinal epithelia exist in a uniquely dynamic oxygen tension microenvironment. Adaptive responses to hypoxia in mammalian cells are regulated largely by hypoxia inducible factor (HIF) transcriptional complexes. Functional HIF exists as an obligate alpha/beta heterodimer, comprising both a constitutive subunit (HIF-1beta), and an oxygen-labile regulatory (alpha) component. To date, three regulatory subunits have been identified, namely HIF-1alpha, HIF-2alpha, and HIF-3alpha, with the highest level of sequence homology conserved between HIF-1alpha and HIF-2alpha. Despite their concurrent expression in intestinal epithelial cells, HIF-1 and HIF-2 play non-redundant roles in the regulation of an overlapping but distinct set of gene targets. In this study, we performed ChIP-on-chip analysis of chromatin isolated from hypoxic intestinal epithelia to delineate HIF-1 and HIF-2 specific loci.
2013-11-05 | GSE43108 | GEO
Project description:Proliferation of neoplastic plasma cells within the bone marrow leads to reduced oxygen availability. In response to hypoxia, the transcription factor hypoxia-inducible factor-2alpha (HIF-2α) is activated and stabilised. We hypothesise that activation of HIF-2α is a central driver of multiple myeloma disease progression, leading to the induction of transcription of genes associated with angiogenesis, osteoclast activation and cell migration. In this study we assessed the affects of HIF-2α overexpression on gene expression in the human myeloma cell line LP-1.
2017-08-04 | GSE102235 | GEO
Project description:Non-small cell lung cancer (NSCLC) is the leading cause of cancer deaths worldwide. The oxygen-sensitive Hypoxia Inducible Factor (HIF) transcriptional regulators HIF-1α and HIF-2α are overexpressed in many human NSCLCs, and constitutive HIF-2α activity can promote murine lung tumor progression, suggesting that HIF proteins may be effective NSCLC therapeutic targets. To investigate the consequences of inhibiting HIF activity in lung cancers, we deleted Hif-1α or Hif-2α in an established KrasG12D-driven murine NSCLC model. Deletion of Hif-1α had no obvious effect on tumor growth, whereas Hif-2α deletion resulted in an unexpected increase in tumor burden that correlated with reduced expression of the candidate tumor suppressor gene Scgb3a1 (HIN-1). Here, we identify Scgb3a1 as a direct HIF-2α target gene, and demonstrate that HIF-2α regulates Scgb3a1 expression and tumor formation in human KrasG12D-driven NSCLC cells. AKT pathway activity, reported to be repressed by Scgb3a1, was enhanced in HIF-2α deficient human NSCLC cells and xenografts. Finally, a direct correlation between HIF-2α and SCGB3a1 expression was observed in approximately 70% of human NSCLC samples analyzed. These data suggest that whereas HIF-2α overexpression can contribute to NSCLC progression, therapeutic inhibition of HIF-2α below a critical threshold may paradoxically promote tumor growth by reducing expression of tumor suppressor genes, including Scgb3a1. RNA was isolated from tumors of experimental (Hif2alpha deficient) mice and control mice (seven for each group).
2010-07-29 | E-GEOD-22575 | biostudies-arrayexpress
Project description:Non-small cell lung cancer (NSCLC) is the leading cause of cancer deaths worldwide. The oxygen-sensitive Hypoxia Inducible Factor (HIF) transcriptional regulators HIF-1α and HIF-2α are overexpressed in many human NSCLCs, and constitutive HIF-2α activity can promote murine lung tumor progression, suggesting that HIF proteins may be effective NSCLC therapeutic targets. To investigate the consequences of inhibiting HIF activity in lung cancers, we deleted Hif-1α or Hif-2α in an established KrasG12D-driven murine NSCLC model. Deletion of Hif-1α had no obvious effect on tumor growth, whereas Hif-2α deletion resulted in an unexpected increase in tumor burden that correlated with reduced expression of the candidate tumor suppressor gene Scgb3a1 (HIN-1). Here, we identify Scgb3a1 as a direct HIF-2α target gene, and demonstrate that HIF-2α regulates Scgb3a1 expression and tumor formation in human KrasG12D-driven NSCLC cells. AKT pathway activity, reported to be repressed by Scgb3a1, was enhanced in HIF-2α deficient human NSCLC cells and xenografts. Finally, a direct correlation between HIF-2α and SCGB3a1 expression was observed in approximately 70% of human NSCLC samples analyzed. These data suggest that whereas HIF-2α overexpression can contribute to NSCLC progression, therapeutic inhibition of HIF-2α below a critical threshold may paradoxically promote tumor growth by reducing expression of tumor suppressor genes, including Scgb3a1.
2010-06-28 | GSE22575 | GEO
Project description:HIF transcription factors (HIF-1 and HIF-2) are central mediators of cellular adaptation to hypoxia. Because the resting partial pressure of oxygen is low in the intestinal lumen, epithelial cells are believed to be mildly hypoxic. Having recently established a link between HIF and the iron-regulatory hormone hepcidin, we hypothesized that HIFs, stabilized in the hypoxic intestinal epithelium, may also play critical roles in regulating intestinal iron absorption. To explore this idea, we first established that the mouse duodenum, the site of iron absorption in the intestine, is hypoxic and generated conditional knockout mice that lacked either Hif1a or Hif2a specifically in the intestinal epithelium. Using these mice, we found that HIF-1alpha was not necessary for iron absorption, whereas HIF-2alpha played a crucial role in maintaining iron balance in the organism by directly regulating the transcription of the gene encoding divalent metal transporter 1 (DMT1), the principal intestinal iron transporter. Specific deletion of Hif2a led to a decrease in serum and liver iron levels and a marked decrease in liver hepcidin expression, indicating the involvement of an induced systemic response to counteract the iron deficiency. This finding may provide a basis for the development of new strategies, specifically in targeting HIF-2alpha, to improve iron homeostasis in patients with iron disorders.
| S-EPMC2673882 | biostudies-literature
Project description:Transcriptional responses to hypoxia are primarily mediated by hypoxia-inducible factor (HIF), a heterodimer of HIF-alpha and the aryl hydrocarbon receptor nuclear translocator subunits. The HIF-1alpha and HIF-2alpha subunits are structurally similar in their DNA binding and dimerization domains but differ in their transactivation domains, implying they may have unique target genes. Previous studies using Hif-1alpha(-/-) embryonic stem and mouse embryonic fibroblast cells show that loss of HIF-1alpha eliminates all oxygen-regulated transcriptional responses analyzed, suggesting that HIF-2alpha is dispensable for hypoxic gene regulation. In contrast, HIF-2alpha has been shown to regulate some hypoxia-inducible genes in transient transfection assays and during embryonic development in the lung and other tissues. To address this discrepancy, and to identify specific HIF-2alpha target genes, we used DNA microarray analysis to evaluate hypoxic gene induction in cells expressing HIF-2alpha but not HIF-1alpha. In addition, we engineered HEK293 cells to express stabilized forms of HIF-1alpha or HIF-2alpha via a tetracycline-regulated promoter. In this first comparative study of HIF-1alpha and HIF-2alpha target genes, we demonstrate that HIF-2alpha does regulate a variety of broadly expressed hypoxia-inducible genes, suggesting that its function is not restricted, as initially thought, to endothelial cell-specific gene expression. Importantly, HIF-1alpha (and not HIF-2alpha) stimulates glycolytic gene expression in both types of cells, clearly showing for the first time that HIF-1alpha and HIF-2alpha have unique targets.
| S-EPMC309606 | biostudies-literature
Project description:The C-terminal activation domain (C-TAD) of the hypoxia-inducible transcription factors HIF-1? and HIF-2? binds the CH1 domains of the related transcriptional coactivators CREB-binding protein (CBP) and p300, an oxygen-regulated interaction thought to be highly essential for hypoxia-responsive transcription. The role of the CH1 domain in vivo is unknown, however. We created mutant mice bearing deletions in the CH1 domains (?CH1) of CBP and p300 that abrogate their interactions with the C-TAD, revealing that the CH1 domains of CBP and p300 are genetically non-redundant and indispensable for C-TAD transactivation function. Surprisingly, the CH1 domain was only required for an average of ~35-50% of global HIF-1?-responsive gene expression, whereas another HIF-transactivation mechanism that is sensitive to the histone deacetylase inhibitor trichostatin A (TSAS) accounts for ~70%. Both pathways are required for greater than 90% of the response for some target genes. Our findings suggest that a novel functional interaction between the protein acetylases CBP and p300, and deacetylases, is essential for nearly all HIF-responsive transcription. Keywords: genetic modification, dose response
2005-10-24 | GSE3318 | GEO
Project description:HIF-1a activates genes under hypoxia and was hypothesized to regulate bone regeneration. Surprisingly, HET HIF-1a fracture calluses are larger, stronger and stiffer than WT HIF-1a calluses due to decreased apoptosis. These data identify apoptosis inhibition as a means to enhance bone regeneration. Introduction: Bone regeneration subsequent to fracture involves the synergistic activation of multiple signaling pathways. Localized hypoxia following fracture activates hypoxia-inducible factor 1 alpha (HIF-1a) leading to increased expression of HIF-1 target genes. We therefore hypothesized that HIF-1a is a key regulator of bone regeneration Materials and Methods: Fixed femoral fractures were generated in mice with partial HIF-1a deficiency (HET HIF-1a) and wild type littermates (WT HIF-1a). Fracture calluses and intact contralateral femurs from post fracture day (PFD) 21 and 28 (N=5-10) were subjected to MicroCT evaluation and 4-point bending in order to assess morphometric and mechanical properties. Molecular analyses were carried out on PFD 7, 10 and 14 samples (N=3) to determine differential gene expression at both mRNA and protein levels. Finally, TUNEL staining was performed on PFD 14 samples (N=2) to elucidate differential apoptosis. Results: Surprisingly, fracture calluses from HET HIF-1a mice exhibit greater mineralization and are larger, stronger and stiffer. Microarray analyses focused on hypoxia-induced genes revealed differential expression (between genotypes) of several genes associated with the apoptotic pathway. Real-time PCR confirmed these results, demonstrating higher expression of pro-apoptotic PP2A and lower expression of anti-apoptotic BCL2 in WT HIF-1a calluses. Subsequent TUNEL staining demonstrates that WT HIF-1a calluses contain larger numbers of TUNEL positive chondrocytes and osteoblasts than HET HIF-1a calluses. Conclusions: We conclude that partial HIF-1a deficiency results in decreased chondrocytic and osteoblastic apoptosis; thereby allowing the development of larger, stiffer calluses and enhancing bone regeneration. Furthermore, apoptosis inhibition may be a promising target for developing new treatments to accelerate bone regeneration. Keywords: Bone, Fracture, Apoptosis, Hypoxia, Microarray
2007-01-12 | GSE6091 | GEO