Project description:Genomewide miRNA profiling of colorectal cancer cell lines and colorectal cancer-derived induced pluripotent cancer cell lines

| PRJNA343975 | ENA

Crystal structure of Homo sapiens kynureninase.

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.

| S-EPMC2531291 | biostudies-literature

Homo sapiens whole blood.

Project description:RNA extracted at 240min. Samples are rRNA depleted. Expression measurement of Homo sapiens genes.

2019-07-31 | GSE114179 | GEO

miR-200 overexpression in colorectal cancer lines

Project description:Unsupervised classification of gene expression profiles has resulted in the identification of biologically and clinically distinct colon cancer subtypes (CCSs). The subtype that associates with poor clinical outcome displays a mesenchymal gene expression profile. No driver mutation has been identified for this category and patients are heterogeneous with regard to commonly used clinical markers. Here we report a regulatory network consisting of the miR-200 family members that tunes the majority of genes differentially expressed in the poor prognosis CCS, including genes involved in the epithelial-mesenchymal transition (EMT) process. Our data indicate that the epigenetic silencing of the miR-200 family by promoter methylation is identifying the mesenchymal CCS and is predictive of disease-free survival in this malignancy. We demonstrate that the molecular features of poor prognosis colon cancer - expression of EMT-associated genes and miR-200 promoter methylation - can already be installed at the premalignant stage, suggesting a highly malignant potential of specific colon cancer precursor lesions. Four colorectal cancer cell lines that display methylated miR-200 loci have been used to overexpress miR-200 family members from both loci separatedly or simultaneously.

2015-09-01 | E-GEOD-65551 | biostudies-arrayexpress

Homo sapiens

Project description:Expression profiles of colorectal cancer cell lines

| PRJNA214975 | ENA