title: Reduced expression of brain-enriched microRNAs in glioblastomas permits targeted regulation of a cell death gene.
abstract: Glioblastoma is a highly aggressive malignant tumor involving glial cells in the human brain. We used high-throughput sequencing to comprehensively profile the small RNAs expressed in glioblastoma and non-tumor brain tissues. MicroRNAs (miRNAs) made up the large majority of small RNAs, and we identified over 400 different cellular pre-miRNAs. No known viral miRNAs were detected in any of the samples analyzed. Cluster analysis revealed several miRNAs that were significantly down-regulated in glioblastomas, including miR-128, miR-124, miR-7, miR-139, miR-95, and miR-873. Post-transcriptional editing was observed for several miRNAs, including the miR-376 family, miR-411, miR-381, and miR-379. Using the deep sequencing information, we designed a lentiviral vector expressing a cell suicide gene, the herpes simplex virus thymidine kinase (HSV-TK) gene, under the regulation of a miRNA, miR-128, that was found to be enriched in non-tumor brain tissue yet down-regulated in glioblastomas, Glioblastoma cells transduced with this vector were selectively killed when cultured in the presence of ganciclovir. Using an in vitro model to recapitulate expression of brain-enriched miRNAs, we demonstrated that neuronally differentiated SH-SY5Y cells transduced with the miRNA-regulated HSV-TK vector are protected from killing by expression of endogenous miR-128. Together, these results provide an in-depth analysis of miRNA dysregulation in glioblastoma and demonstrate the potential utility of these data in the design of miRNA-regulated therapies for the treatment of brain cancers.
authors.affiliation: Department of Molecular Genetics and Microbiology and Center for Virology, Duke University Medical Center, Durham, North Carolina, United States of America.
authors.forename: Rebecca L
authors.initials: RL
authors.lastname: Skalsky
authors.forename: Bryan R
authors.initials: BR
authors.lastname: Cullen
mesh_terms: D001483:Base Sequence; D001921:Brain / Q000378:metabolism* / Q000473:pathology*; D016923:Cell Death / Q000235:genetics*; D045744:Cell Line, Tumor; D017931:DNA Primers / Q000235:genetics; D015536:Down-Regulation / Q000235:genetics*; D041722:Genes, Transgenic, Suicide / Q000235:genetics; D015316:Genetic Therapy; D014644:Genetic Variation / Q000235:genetics; D005822:Genetic Vectors / Q000235:genetics; D005909:Glioblastoma / Q000235:genetics / Q000473:pathology* / Q000628:therapy; D018259:Herpesvirus 1, Human / Q000201:enzymology; D059014:High-Throughput Nucleotide Sequencing; D006801:Humans; D035683:MicroRNAs / Q000235:genetics* / Q000378:metabolism; D009474:Neurons / Q000378:metabolism / Q000473:pathology; D009928:Organ Specificity; D017393:RNA Editing; D015203:Reproducibility of Results; D013937:Thymidine Kinase / Q000235:genetics; D059467:Transcriptome / Q000235:genetics
chemical_list: D017931:DNA Primers; C545189:MIRN128 microRNA, human; C582326:MIRN411 microRNA, human; D035683:MicroRNAs; D013937:Thymidine Kinase