Project description:Irinotecan, an analogue of camptothecin, is frequently used in combination with various anticancer drugs or as a single agent in treatment of colorectal cancer. But drug resistance of tumor is still a major obstacle to overcome for the success of cancer treatment. In this study, We established chronic irinotecan resistant cell line for new marker to increase the sensitivity to irinotecan and investigated gene expression profiles of the irinotecan-resistant colorectal cancer cell line. To create stable CRC cell line chronically resistant to Irinotecan, LoVo cell was exposed to an initial Irinotecan concentration of 0.1 M-NM-<mol/L in RPMI 1640 supplemented with 10% FBS. When the growth of the cultured cells reaches at 80% confluency, cells were passaged twice at same drug concentration to ensure adaptation and then concentration of Irinotecan was sequentially increased in the same manner to 8 M-NM-<mol/L and then we investigated the gene expressions between parental colorectal cancer cell line, LoVo and Irinotecan resistant LoVo cell lines
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:Oxaliplatin resistance was induced in 2 colorectal cancer cell lines (LoVo-92, wt-p53 and LoVo-Li, functionally inactive p53) and one ovarian cancer cell line (A2780, wt-p53). Resistance was induced by weekly exposure to oxaliplatin for 4 hrs or 72 hrs with increasing concentrations for a period of 7 months Genomic DNA of oxaliplatin and cisplatin resistant colorectal cancer and ovarian cancer cell lines as well as the parental cell lines were labeled and subsequently hybridized against pooled reference DNA of healthy volunteers of the opposite gender using across array hybridization. Extracted raw-data were normalised and smoothend using the R-script NOWAVE resulting in normalised log2 ratio profiles of resistant cell line versus parental cell line and parental cell line versus reference DNA.
Project description:Six non- and drug-resistant colorectal cancer cell lines were selected in this study, which were non-resistant cell lines: HCT116 and LoVo, four drug-resistant cell lines: HCT116-OxPt, HCT116-SN38, LoVo-OxPt, LoVo-SN38.Proteins extraced from three HCT116 related cell lines were labled and pooled together, and proteins from other three LoVo related cell lines were labled and pooled together.
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: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:A Cartes d'Identite des Tumeurs (CIT) project from the French National League Against Cancer (http://cit.ligue-cancer.net ) 25 glioblastoma multiforme tumors hybridized on Illumina SNP and Affymetrix gene expression arrays. Project leader : François DUCRAY (francois.ducray@chu-lyon.fr). CIT Analysis : Julien LAFFAIRE (laffairej@ligue-cancer.net). Note: PFS : progression-free survival, OS: Overall Survival,BCNU : Carmustine (chemotherapy agent). RESPONDER: if the patient has shown or not shown a response to the treatment (Bevacizumab (Avastin) plus Irinotecan). Progression during : If the disease has progressed (cancer relapse or patient's death); otherwise (patient is alive without relapse).