Project description:VHL is a tumor suppressor gene involved in the oxygen-sensing pathway whose germline mutations predispose to distinct phenotypes. Heterozygous mutations predispose to von Hippel-Lindau disease characterized by the development of multiple tumors (including hemangioblastomas, renal cell carcinomas and pheochromocytomas)1-3. More recently, a specific VHL-R200W mutation was shown to be responsible for Chuvash Polycythemia in homozygous carriers whereas heterozygous individuals have no clinical manifestation4. We report here a family carrying, on the same allele, VHL mutations characteristics of the two types of disease (a Chuvash polycythemia-R200W mutation and a von Hippel-Lindau disease-R161Q mutation). Genotyping, modeling analysis and functional studies, including transcriptomic profile of the distinct mutants validated for the first time on direct HIF target genes, show a gradual capacity of the VHL mutants to regulate the hypoxia responsive pathway that correlate with the severity of the developed phenotype. Our study provide original results that illuminate genotype/phenotype correlations in von Hippel-Lindau disease.
Project description:The von Hippel-Lindau (VHL) tumor suppressor functions as a ubiquitin ligase that mediates proteolytic inactivation of hydroxylated a subunits of hypoxia-inducible factor (HIF). Although studies of VHL defective renal carcinoma cells suggest the existence of other VHL tumor suppressor pathways, dysregulation of the HIF transcriptional cascade has extensive effects that make it difficult to distinguish whether, and to what extent, observed abnormalities in these cells represent effects on pathways that are distinct from HIF. Here, we report on a genetic analysis of HIF dependent and independent effects of VHL inactivation by studying gene expression patterns in C. elegans. We show tight conservation of the HIF-1/VHL-1/EGL-9 hydroxylase pathway. However, persisting differential gene expression in hif-1 versus hif-1; vhl-1 double mutant worms clearly distinguished HIF-1 independent effects of VHL-1 inactivation. Genomic clustering, predicted functional similarities, and a common pattern of dysregulation in both vhl-1 worms and a set of mutants (dpy-18, let-268, gon-1, mig-17 and unc-6), with different defects in extracellular matrix formation, suggest that dysregulation of these genes reflects a discrete HIF-1 independent function of VHL-1 that is connected with extracellular matrix function. Set of arrays organized by shared biological context, such as organism, tumors types, processes, etc. Bishop T, Lau KW, Epstein AC, Kim SK, Jiang M, O'rourke D, Pugh CW, Gleadle JM, Taylor MS, Hodgkin J, Ratcliffe PJ, Genetic Analysis of Pathways Regulated by the von Hippel-Lindau Tumor Suppressor in Caenorhabditis elegans., Bishop T, et al. (2004) PLoS Biol 2(10):e289, 2004-10-01, http://biology.plosjournals.org/plosonline/?request=get-document&doi=10.1371/journal.pbio.0020289 Computed
Project description:GNE987 is a newly developed von Hippel-Lindau tumor suppressor (VHL)-based pan-BET-targeting PROTAC, which can bind to the target proteins (BET proteins, including BRD2, BRD3, and BRD4) and recruit them to the ubiquitin/proteasome system for selective degradation. In the our study, ChIP-Seq analysis was performed to explore the effect of GNE987 on osteosarcoma cells.
Project description:Clear cell renal cell carcinoma (ccRCC), the most common type of renal cancer is often associated with inactivation of the tumor suppressor gene von-Hippel Lindau (VHL), leading to stable expression of hypoxia inducible factors, HIF1α and HIF2α. Although HIF1α functions as a tumor suppressor gene, majority of ccRCCs constitutively express HIF1α, stratifying VHL-deficient ccRCCs into groups which express either both HIF1α and HIF2α (H1H2) or HIF2α exclusively (H2). MicroRNA (miRNA) profiling performed in these two ccRCC subtypes to identify novel molecular mechanisms.
Project description:Clear cell renal cell carcinoma (ccRCC), the most common type of renal cancer is often associated with inactivation of the tumor suppressor gene von-Hippel Lindau (VHL), leading to stable expression of hypoxia inducible factors, HIF1α and HIF2α. Although HIF1α functions as a tumor suppressor gene, majority of ccRCCs constitutively express HIF1α, stratifying VHL-deficient ccRCCs into groups which express either both HIF1α and HIF2α (H1H2) or HIF2α exclusively (H2). MicroRNA (miRNA) profiling performed in these two ccRCC subtypes to identify novel molecular mechanisms. ccRCCs were classified into H1H2 and H2 subtypes by immunohostochemical staining of H1F1α and H1F2α expression. Five H1H2 tumor samples and eight H2 tumor samples were used for the study. Matched adjacent normal renal tissues were used as respective controls.
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:Analysis of gene expression changes in the von Hippel Lindau when mutant compared to wild-type at 4dpf using a whole genome microarray expression profiling. The von Hippel Lindau mutant displays a systemic hypoxic response under normoxic conditions. We performed single-colour microarrays to identify the gene expression changes which underpin the hypoxic phenotype. We used 3 biological replicates from both mutant and control, followed by analysis using Limma to identify significant gene expression changes. This work, together with ChIP-seq data for the Hif-1α in von Hippel Lindau mutants, should allow for the Hif-1α dependency of these gene expression changes to be assessed. The changes in gene expression between von Hippel Lindau mutants and wild-type controls was measured at 4 days post fertilisation. For both wild-type and mutant, 3 biological replicates, each of 30 embryos were used.
Project description:The von Hippel-Lindau (VHL) tumor suppressor functions as a ubiquitin ligase that mediates proteolytic inactivation of hydroxylated a subunits of hypoxia-inducible factor (HIF). Although studies of VHL defective renal carcinoma cells suggest the existence of other VHL tumor suppressor pathways, dysregulation of the HIF transcriptional cascade has extensive effects that make it difficult to distinguish whether, and to what extent, observed abnormalities in these cells represent effects on pathways that are distinct from HIF. Here, we report on a genetic analysis of HIF dependent and independent effects of VHL inactivation by studying gene expression patterns in C. elegans. We show tight conservation of the HIF-1/VHL-1/EGL-9 hydroxylase pathway. However, persisting differential gene expression in hif-1 versus hif-1; vhl-1 double mutant worms clearly distinguished HIF-1 independent effects of VHL-1 inactivation. Genomic clustering, predicted functional similarities, and a common pattern of dysregulation in both vhl-1 worms and a set of mutants (dpy-18, let-268, gon-1, mig-17 and unc-6), with different defects in extracellular matrix formation, suggest that dysregulation of these genes reflects a discrete HIF-1 independent function of VHL-1 that is connected with extracellular matrix function. Set of arrays organized by shared biological context, such as organism, tumors types, processes, etc. Bishop T, Lau KW, Epstein AC, Kim SK, Jiang M, O'rourke D, Pugh CW, Gleadle JM, Taylor MS, Hodgkin J, Ratcliffe PJ, Genetic Analysis of Pathways Regulated by the von Hippel-Lindau Tumor Suppressor in Caenorhabditis elegans., Bishop T, et al. (2004) PLoS Biol 2(10):e289, 2004-10-01, http://biology.plosjournals.org/plosonline/?request=get-document&doi=10.1371/journal.pbio.0020289 Keywords: Logical Set
Project description:Analysis of gene expression changes in the von Hippel Lindau when mutant compared to wild-type at 4dpf using a whole genome microarray expression profiling. The von Hippel Lindau mutant displays a systemic hypoxic response under normoxic conditions. We performed single-colour microarrays to identify the gene expression changes which underpin the hypoxic phenotype. We used 3 biological replicates from both mutant and control, followed by analysis using Limma to identify significant gene expression changes. This work, together with ChIP-seq data for the Hif-1α in von Hippel Lindau mutants, should allow for the Hif-1α dependency of these gene expression changes to be assessed.
Project description:786-0 is a cell line derived from a clear cell renal carcinoma. Previous studies have shown that the 786-O cell line harbors an inactivating mutation in the von-Hippel Lindau (VHL) gene. Mutations in the VHL gene occur in the majority of sporadic clear cell renal cell. To determine how inactivation of the VHL affects cellular functions, we created a derivative of 786-0, which we call 786-VHL in which a functional allele of VHL has been introduced back into the 786-O cell line. The renal cell carcinoma cell line 786-0, which harbors a mutated allele of VHL, was compared to a cell line derived from 786-0, termed 786-VHL, that contains a functional allele of VHL. Genes whose expression characteristics were dependent on functional VHL were identified.