Project description:Using Affymetrix GeneChip® Human Genome U133 Plus 2.0 Array, we compared the gene expression profiles between the glioma cell lines U87 and Glio6, cultured at 3% of oxygene.
Project description:How cancer cells adapt to hypoxia during tumor development remains an important question. The hypothesis tested in the present study was that tumor cell-derived exosome vesicles (also known as microvesicles or extracellular vesicles) are mediators of hypoxia-dependent intercellular signaling in glioblastoma (GBM), i.e. highly aggressive brain tumors characterized by hypoxia and a vascular density that is among the highest of all human malignancies. In vitro hypoxia experiments and studies with patient materials reveal the enrichment in exosomes of hypoxia-regulated mRNAs and proteins, several of which were associated with poor patient prognosis. We show that cancer cell exosomes mediate hypoxia-dependent, phenotypic modulation of stromal cells in vitro and ex vivo, resulting in accelerated GBM tumor angiogenesis and growth in mice. These data suggest that exosomes constitute potent mediators of hypoxia-driven tumor development, and circulating multiparameter biomarkers of tumor hypoxia. U87 MG glioblastoma cells were grown at normoxic (21% oxygen) or hypoxic (1% oxygen) conditions for 48 hours. Conditioned media from normoxic and hypoxic cells were then used to isolate exosomes by differential centrifugation. Both cells and exosomes were lysed in Trizol reagent, and RNA was isolated.Total RNA from all samples (four types of samples in three biological repilicates) was subjected to genome-wide transcriptional analysis with Illumina HumanHT-12 V3.0 expression beadchip. Gene expression profile obtained from hypoxic U87 MG glioblastoma cells was compared to the profile of normoxic control cells. Analogically, gene expression profile obtained from hypoxic U87 MG cells was compared to the profile of exosomes secreted by normoxic U87 MG cells.
Project description:An experimental lung metastasis assay was used to derive an invasive subline of U87 that is metastatic in mice. We used microarray analyses to find out over-represented gene ontologies that can explain the observed enhanced invasiveness of U87-2M1 cells. Early passage U87-2M1 cells and parental U87 glioma cells from ATCC were selected for RNA extraction and hybridization on microarray
Project description:To identify a novel miRNA that is aberrantly expressed in GICs, we analyzed differences in miRNA expression between the human GICs and glioma cell lines and neural stem cells by miRNA microarrays. We examined the miRNA expression profiles of five human GICs that were obtained from human glioma samples and two human glioma cell lines, U87 and U251, and NSC (neural stem cells) as a control.
Project description:GPR17 over-expression inhibits glioma cell proliferation and induces apoptosis by raising ROS levels, and mechanistically inhibits the transcription of RNF2, leading to reduced histone H2A monoubiquitination. Here, To identify the genes mediating the effects of GPR17 and RNF2 on ROS level, we performed RNA-Seq of WT and U87-GPR17 cells and RNF2 ChIP-Seq of WT and U87-shGPR17 cells.
Project description:We have employed whole RNA microarray expression profiling as a discovery platform to identify genes regulated by overexpression of miR-145 in U87 glioma cell. Lentivirus containing miR-145 coding sequence was infected to U87 cell to make U87 overexpressing miR-145. We did genome microarray between U87 and U87 overexpressing miR-145.
Project description:FOXM1 plays a key role in M phase in normal cells and is overexpressed in human glioma. We found that FOXM1 deprivation could sensitize the glioma cells to TMZ chemotherapy. To find out the mechanistic regulation of FOXM1 in chemo-resistant genes, we used microarrays to select the potential genes regulated by FOXM1 which dominates in glioma chemo-resistance. U87 glioma cells were transiently transfected with none-target siRNA or FOXM1 siRNA. Total RNA were extracted after 48 hours and subjected to the microarray.
Project description:We have sequenced miRNA libraries from human embryonic, neural and foetal mesenchymal stem cells. We report that the majority of miRNA genes encode mature isomers that vary in size by one or more bases at the 3’ and/or 5’ end of the miRNA. Northern blotting for individual miRNAs showed that the proportions of isomiRs expressed by a single miRNA gene often differ between cell and tissue types. IsomiRs were readily co-immunoprecipitated with Argonaute proteins in vivo and were active in luciferase assays, indicating that they are functional. Bioinformatics analysis predicts substantial differences in targeting between miRNAs with minor 5’ differences and in support of this we report that a 5’ isomiR-9-1 gained the ability to inhibit the expression of DNMT3B and NCAM2 but lost the ability to inhibit CDH1 in vitro. This result was confirmed by the use of isomiR-specific sponges. Our analysis of the miRGator database indicates that a small percentage of human miRNA genes express isomiRs as the dominant transcript in certain cell types and analysis of miRBase shows that 5’ isomiRs have replaced canonical miRNAs many times during evolution. This strongly indicates that isomiRs are of functional importance and have contributed to the evolution of miRNA genes