Project description:FASTQ Sequencing files of 5 healthy pancreas tissues and 6 pancreatic ductal adenocarcinoma (PDAC) tissues. Analysis of data is presented in the manuscript: Next generation sequencing reveals novel differentially regulated mRNAs, lncRNAs, miRNAs, sdRNAs and a piRNA in pancreatic cancer in BMC Molecular Cancer.
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.
Project description:We reported glutathione peroxidase-1 (GPx1) was negatively associated with overall survival in pancreatic ductal adenocarcinoma patients. Silencing GPx1 in pancreatic cancer cells showed epithelial–mesenchymal transition phenotype and increased chemoresistance to gemcitabine in vitro and in vivo. Next, to search for a putative molecular mechanism, we used a high-throughput gene expression profiling array in scramble-shRNA and GPx1-shRNA pancreatic cancer cells (MiaPaCa-2). This study provides the differentially expressed genes and altered signaling pathways towards characterization of gemcitabine resistance cell populations.