Project description:The host antitumor immunity changes drastically during carcinogenesis. Intraductal papillary-mucinous neoplasm (IPMN) of the pancreas is a precursor lesion of pancreatic cancer and progresses according to adenoma-carcinoma sequence. We found that the host antitumor immune reaction changes from an immune response to immune tolerance between intraductal papillary-mucinous adenoma (IPMA) and intraductal papillary-mucinous carcinoma (IPMC). In order to determine molecules affecting intraepithelial DC infiltration in IPMNs during multistep carcinogenesis, we examined the gene-expression profiles of entire transcripts of neoplastic cells at different stages. We collected normal and neoplastic epithelial cells from frozen tissue sections (normal main pancreatic duct, IPMA, IPMC, and invasive carcinoma originating in IPMN) by laser microdissection, extracted total RNA from them, and analyzed their gene expression profiles using Affymetrix microarrays.
Project description:Transcriptional profiling of human mesenchymal stem cells comparing normoxic MSCs cells with hypoxic MSCs cells. Hypoxia may inhibit senescence of MSCs during expansion. Goal was to determine the effects of hypoxia on global MSCs gene expression.
Project description:The host antitumor immunity changes drastically during carcinogenesis. Intraductal papillary-mucinous neoplasm (IPMN) of the pancreas is a precursor lesion of pancreatic cancer and progresses according to adenoma-carcinoma sequence. We found that the host antitumor immune reaction changes from an immune response to immune tolerance between intraductal papillary-mucinous adenoma (IPMA) and intraductal papillary-mucinous carcinoma (IPMC). In order to determine molecules affecting intraepithelial DC infiltration in IPMNs during multistep carcinogenesis, we examined the gene-expression profiles of entire transcripts of neoplastic cells at different stages.
Project description:Transcriptional profiling of human mesenchymal stem cells comparing normoxic MSCs cells with hypoxic MSCs cells. Hypoxia may inhibit senescence of MSCs during expansion. Goal was to determine the effects of hypoxia on global MSCs gene expression. Two-condition experiment, Normoxic MSCs vs. Hypoxic MSCs.
Project description:Gene expression profiling of immortalized human mesenchymal stem cells with hTERT/E6/E7 transfected MSCs. hTERT may change gene expression in MSCs. Goal was to determine the gene expressions of immortalized MSCs.
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.