title: Analysis of target genes induced by IL-13 cytotoxin in human glioblastoma cells.
abstract: IL-13 cytotoxin comprised of IL-13 and a mutated form of Pseudomonas exotoxin (fusion protein termed IL-13-PE38QQR) has been shown to inhibit protein synthesis leading to necrotic and apoptotic cell death in glioblastoma cells that express high levels of interleukin-13 receptors (IL-13R). To identify target genes of cell death and other cellular genes with IL-13 receptors in glioblastoma cells, we utilized the cDNA microarrays to analyze global gene expression profiles after IL-13 cytotoxin and IL-13 treatment. IL-13 cytotoxin mediated cytotoxicity to U251 cells in a dose-dependent manner. Hierarchical cluster analysis of differentially expressed genes in U251 glioma cells at different time points after IL-13 cytotoxin treatment showed three major groups, each representing a specific expression pattern. Randomly selected differentially expressed genes from each group were confirmed by RT-PCR analysis. Most down-regulated genes belong to cell adhesion, motility, angiogenesis, DNA repair, and metabolic pathways. While up-regulated genes belong to cell cycle arrest, apoptosis, signaling and various metabolic pathways. Unexpectedly, at early time points, both IL-13 and IL-13 cytotoxin induced several genes belonging to different pathways most notably IL-8, DIO2, END1, and ALDH1A3 indicating that these genes are early response genes and their products may be associated with IL-13R. In addition, IL-13 cytotoxin induced IL-13Ralpha2 mRNA expression during the treatment in glioma cells. Our results indicate that novel cellular genes are involved with IL-13 receptors and that IL-13 cytotoxin induced cell death involves various target genes in human glioblastoma cells. On going studies will determine the role of associated genes and their products in the IL-13R functions in glioma cells.
authors.affiliation: Laboratory of Molecular Tumor Biology, CBER/NCI Genomics Program, Division of Cellular and Gene Therapies, Center for Biologics Evaluation and Research, Food and Drug Administration, CBER/FDA, NIH, Bethesda, MD 20892, USA.
authors.forename: Jing
authors.initials: J
authors.lastname: Han
authors.forename: Liming
authors.initials: L
authors.lastname: Yang
authors.forename: Raj K
authors.initials: RK
authors.lastname: Puri
mesh_terms: D036002:ADP Ribose Transferases / Q000494:pharmacology; D000970:Antineoplastic Agents / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects / Q000502:physiology; D001427:Bacterial Toxins / Q000494:pharmacology; D001932:Brain Neoplasms / Q000188:drug therapy / Q000235:genetics*; D016923:Cell Death / Q000187:drug effects; D045744:Cell Line, Tumor; D016000:Cluster Analysis; D003603:Cytotoxins / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D005098:Exotoxins / Q000494:pharmacology*; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D020868:Gene Silencing; D005909:Glioblastoma / Q000188:drug therapy / Q000235:genetics*; D006801:Humans; D000922:Immunotoxins / Q000494:pharmacology*; D018793:Interleukin-13 / Q000494:pharmacology*; D053661:Interleukin-13 Receptor alpha1 Subunit; D009363:Neoplasm Proteins / Q000187:drug effects / Q000378:metabolism*; D018123:Receptors, Interleukin / Q000187:drug effects / Q000378:metabolism; D053660:Receptors, Interleukin-13; D011993:Recombinant Fusion Proteins; D037521:Virulence Factors / Q000494:pharmacology; D000097668:Pseudomonas aeruginosa Exotoxin A
chemical_list: D036002:ADP Ribose Transferases; D000970:Antineoplastic Agents; D001427:Bacterial Toxins; D003603:Cytotoxins; D005098:Exotoxins; D000922:Immunotoxins; D018793:Interleukin-13; D053661:Interleukin-13 Receptor alpha1 Subunit; D009363:Neoplasm Proteins; D018123:Receptors, Interleukin; D053660:Receptors, Interleukin-13; D011993:Recombinant Fusion Proteins; D037521:Virulence Factors; D000097668:Pseudomonas aeruginosa Exotoxin A; C521502:IL13-PE38; C508181:IL13RA1 protein, human