Project description:HIF-2alpha is essential for (VHL-/-) ccRCC subcutaneous tumor growth in mice, and in tumor cell lines, its inhibition results in increased ROS accumulation, tumor cell death and responsiveness to radiation treatment. We have utilized transcriptional profiling to screen for putative HIF-2alpha targets genes that serve an anti-oxidant and, thus, cell survival function. A498 ccRCC cell line was treated with control siRNA or mixture of two HIF-2alpha specific siRNA for 48 hours, and RNA was harvested. 4 independent experiments were performed, and expression was compared between control and HIF-2alpha knockdown groups.
Project description:Human renal cell carcinomas (RCC) have differential expression of HIF-1alpha and HIF-2alpha, depending on VHL genotype and other events. Here, we have divided a series of RCC samples based on HIF-alpha expression, in order to examine levels of genomic DNA aberration. Keywords: Patient Sample Study A total of 57 frozen RCC samples were stained for HIF-1alpha and HIF-2alpha, and genotyped for VHL. 10 VHL-deficient/HIF-1alpha+/HIF-2alpha+ and 11 VHL-deficient/HIF-2alpha+ tumors were selected for array CGH.
Project description:Human renal cell carcinomas (RCC) have differential expression of HIF-1alpha and HIF-2alpha, depending on VHL genotype and other events. Here, we have divided a series of RCC samples for HIF-alpha expression and VHL genotype, in order to define differentially expressed genes Keywords: Patient Sample Study A total of 57 frozen RCC samples were stained for HIF-1alpha and HIF-2alpha, and genotyped for VHL. 5 VHL WT/HIF-negative, 8 VHL-deficient/HIF-1alpha+/HIF-2alpha+ and 8 VHL-deficient/HIF-2alpha+ tumors were selected for microarray
Project description:HIF-2alpha is essential for (VHL-/-) ccRCC subcutaneous tumor growth in mice, and in tumor cell lines, its inhibition results in increased ROS accumulation, tumor cell death and responsiveness to radiation treatment. We have utilized transcriptional profiling to screen for putative HIF-2alpha targets genes that serve an anti-oxidant and, thus, cell survival function. A498 ccRCC cell line was treated with control siRNA or mixture of two HIF-2alpha specific siRNA for 48 hours, and RNA was harvested. 4 independent experiments were performed, and expression was compared between control and HIF-2alpha knockdown groups. 8 total samples were applied to Affymetrix Human Gene 1.0 ST Arrays. We performed two-class paired analysis using Significance Analysis of Microarrays (SAM) software to compare expression in the CT (control siRNA) and H2 (Hif2-alpha siRNA) groups.
Project description:Journal : Blood. 2009 Jul 9;114(2):469-77. Epub 2009 May 13. Title : Endothelial deletion of hypoxia-inducible factor-2alpha (HIF-2alpha) alters vascular function and tumor angiogenesis. Authors : Skuli N, Liu L, Runge A, Wang T, Yuan L, Patel S, Iruela-Arispe L, Simon MC, Keith B. Abstract : Hypoxia-inducible factor-2alpha (HIF-2alpha) is highly expressed in embryonic vascular endothelial cells (ECs) and activates the expression of target genes whose products modulate vascular function and angiogenesis. In this report, we describe a genetic model designed to test the physiologic consequences of deleting HIF-2alpha in murine endothelial cells. Surprisingly, mice with HIF-2alpha-deficient ECs developed normally but displayed a variety of phenotypes, including increased vessel permeability, aberrant endothelial cell ultrastructure, and pulmonary hypertension. Moreover, these animals exhibited defective tumor angiogenesis associated with increased hypoxic stress and tumor cell apoptosis. Immortalized HIF-2alpha-deficient ECs displayed decreased adhesion to extracellular matrix proteins and expressed reduced levels of transcripts encoding fibronectin, integrins, endothelin B receptor, angiopoietin 2, and delta-like ligand 4 (Dll4). Together, these data identify unique cell-autonomous functions for HIF-2alpha in vascular endothelial cells. Keywords: Murine lung endothelial cell study
Project description:Journal : Blood. 2009 Jul 9;114(2):469-77. Epub 2009 May 13. Title : Endothelial deletion of hypoxia-inducible factor-2alpha (HIF-2alpha) alters vascular function and tumor angiogenesis. Authors : Skuli N, Liu L, Runge A, Wang T, Yuan L, Patel S, Iruela-Arispe L, Simon MC, Keith B. Abstract : Hypoxia-inducible factor-2alpha (HIF-2alpha) is highly expressed in embryonic vascular endothelial cells (ECs) and activates the expression of target genes whose products modulate vascular function and angiogenesis. In this report, we describe a genetic model designed to test the physiologic consequences of deleting HIF-2alpha in murine endothelial cells. Surprisingly, mice with HIF-2alpha-deficient ECs developed normally but displayed a variety of phenotypes, including increased vessel permeability, aberrant endothelial cell ultrastructure, and pulmonary hypertension. Moreover, these animals exhibited defective tumor angiogenesis associated with increased hypoxic stress and tumor cell apoptosis. Immortalized HIF-2alpha-deficient ECs displayed decreased adhesion to extracellular matrix proteins and expressed reduced levels of transcripts encoding fibronectin, integrins, endothelin B receptor, angiopoietin 2, and delta-like ligand 4 (Dll4). Together, these data identify unique cell-autonomous functions for HIF-2alpha in vascular endothelial cells. Keywords: Murine lung endothelial cell study Cnt1,2 and 3 (Hif-2a floxed/floxed) cells were subjected to 0.5% oxygen treatment for 16hrs and KO1,2 and 3 (Hif-2a knockout) cells were subjected to 0.5% oxygen treatment for 16hrs.
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.
Project description:Human renal cell carcinomas (RCC) have differential expression of HIF-1alpha and HIF-2alpha, depending on VHL genotype and other events. Here, we have divided a series of RCC samples based on HIF-alpha expression, in order to examine levels of genomic DNA aberration. Keywords: Patient Sample Study
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.
Project description:Primary human macrophages with a HIF-1alpha or HIF-2alpha knockdown were pretreated with IL-10 for 16h and afterwards for 4h additionaly under hypoxi (1% O2), RNA was isolated usind the Qiagen RNAeasy Kit and cDNA synthesis wos done using Ambion WT Expression Kit. Expression was compared to si control under control conditions.