Project description:The human renal cancer cell line 786-0 was transfected with 3 vectors allowing the doxycycline-inducible expression of 1) the full length wild type sequence of VHL: 786-0 VHL WT, VHL+/+, 2) the R167Q mutant : 786-0 R167Q, VHL mutated, 3) the empty vector : 786-0 EV, VHL-/-. The aim of the study was to examine whether the VHL-R167Q mutation, which is associated with a high risk of developping clear cell renal carcinomas, could impact the plasticity of renal carcinoma cells.
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.
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.
Project description:RCC cells (786-O) were transfected with VHL. The parental cell line should be compared to the transfectant (+ VHL) under nomoxia as well as under hypoxia conditions. We want to distinct the VHL-mediated gene expression from the hypoxia-mediated and study the influence of both on the cellular metabolism. RNA of VHL-negative 786-O RCC cell line and VHL-transfectants incubated during normoxia and hypoxia conditions were analysed by cDNA microarray.
Project description:RCC cells (786-O) were transfected with VHL. The parental cell line should be compared to the transfectant (+ VHL) under nomoxia as well as under hypoxia conditions. We want to distinct the VHL-mediated gene expression from the hypoxia-mediated and study the influence of both on the cellular metabolism.
Project description:Inactivation of the E3 ubiquitin ligase protein von Hippel-Lindau (VHL) is critical to clear cell renal cell carcinomas (ccRCC) and VHL syndrome. VHL loss leads to stabilization of hypoxia-inducible factor α (HIFα) and other substrate proteins, which may drive various tumor-promoting pathways. This process is likely reversible, because even in the highly aggressive human VHL-deficient ccRCC cell line 786-O, restoring VHL expression almost completely abolishes orthotopic tumor formation in immuno-deficient mice. This result highlights the potential of treating ccRCC by re-expressing VHL with gene therapy. However, there is inadequate understanding of the consequence of VHL restoration at the molecular level. Here, we reinstalled VHL expression in 786-O and performed transcriptome, proteome and ubiquitome profiling to assess the molecular impact.
Project description:VHL loss is the most common genetic alteration event in ccRCC. By profiling histone modifications from VHL-deficient ccRCC primary tumors and cell lines, we identifed tumor-associated promoters and enhancers. We next investigate whether VHL restoration alters tumor associated promoters and enhancers. We compared H3K27ac ChIP-seq with and without VHL restoration in 786-O cells. Restoration of wild-type VHL significantly altered a subset of tumor enhancers but affected promoters to a less extent.
Project description:VHL loss is the most common genetic alteration event in ccRCC. VHL loss stabilizes hypoxia-inducible factor-2 alpha (HIF2a). We compared the changes in transcriptomics profiles after VHL restoration or HIF2a siRNA knockdown in 786-O cells.
Project description:Kynureninase is a member of a large family of catalytically diverse but structurally homologous pyridoxal 5'-phosphate (PLP) dependent enzymes known as the aspartate aminotransferase superfamily or alpha-family. The Homo sapiens and other eukaryotic constitutive kynureninases preferentially catalyze the hydrolytic cleavage of 3-hydroxy-l-kynurenine to produce 3-hydroxyanthranilate and l-alanine, while l-kynurenine is the substrate of many prokaryotic inducible kynureninases. The human enzyme was cloned with an N-terminal hexahistidine tag, expressed, and purified from a bacterial expression system using Ni metal ion affinity chromatography. Kinetic characterization of the recombinant enzyme reveals classic Michaelis-Menten behavior, with a Km of 28.3 +/- 1.9 microM and a specific activity of 1.75 micromol min-1 mg-1 for 3-hydroxy-dl-kynurenine. Crystals of recombinant kynureninase that diffracted to 2.0 A were obtained, and the atomic structure of the PLP-bound holoenzyme was determined by molecular replacement using the Pseudomonas fluorescens kynureninase structure (PDB entry 1qz9) as the phasing model. A structural superposition with the P. fluorescens kynureninase revealed that these two structures resemble the "open" and "closed" conformations of aspartate aminotransferase. The comparison illustrates the dynamic nature of these proteins' small domains and reveals a role for Arg-434 similar to its role in other AAT alpha-family members. Docking of 3-hydroxy-l-kynurenine into the human kynureninase active site suggests that Asn-333 and His-102 are involved in substrate binding and molecular discrimination between inducible and constitutive kynureninase substrates.