Project description:We cultured tumor cells from 22 GBM under medium conditions favoring the growth of neural stem cells. 11 out of 15 primary GBM contained a significant CD133+ subpopulation that comprised cells showing all hallmarks of neural stem cells. Cell lines derived from these CD133+ GBM showed a neurosphere-like, non-adherent growth pattern. In contrast, 4 out of 15 cell lines derived from primary GBM grew adherent in vitro and were driven by CD133- tumor cells that fulfilled stem cell criteria. In vivo, these GBM were characterized by a significantly lower proliferation index but similar GFAP staining as compared to CD133+ GBM. Gene arrays from 2x3 representative cells lines are given. Experiment Overall Design: Human glioblastoma cells cultured in DMEM supplemented with EGF, FGF, LIF, B27.
Project description:We cultured tumor cells from 22 GBM under medium conditions favoring the growth of neural stem cells. 11 out of 15 primary GBM contained a significant CD133+ subpopulation that comprised cells showing all hallmarks of neural stem cells. Cell lines derived from these CD133+ GBM showed a neurosphere-like, non-adherent growth pattern. In contrast, 4 out of 15 cell lines derived from primary GBM grew adherent in vitro and were driven by CD133- tumor cells that fulfilled stem cell criteria. In vivo, these GBM were characterized by a significantly lower proliferation index but similar GFAP staining as compared to CD133+ GBM. Gene arrays from 2x3 representative cells lines are given. Keywords: Cancer stem cell, CD133, glioblastoma
Project description:We use gene expression data to provide a three-faceted analysis on the links between molecular subclasses of glioblastima, epithelial-to mesenchymal transition (EMT) and CD133 cell surface protein. The contribution of this paper is three-folded: First, we used a newly identified signature for epithelial-to-mesenchymal transition in human mammary epithelial cells, and demonstrated that genes in this signature have significant overlap with genes differentially expressed in all known GBM subtypes. However, the overlap between the genes up-regulated in the mesenchymal subtype of GBM and in the EMT signature was more significant than other GBM subtypes. Second, we provided evidence that there is a negative correlation between the genetic signature of EMT and that of CD133 cell surface protein, a putative marker for neural stem cells. Third, we studied the correlation between GBM molecular subtypes and the genetic signature of CD133 cell surface protein. We demonstrated that the mesenchymal and neural subtypes of GBM have the strongest correlations with the CD133 genetic signature. While the mesenchymal subtype of GBM demonstrates similarity with the signatures of both EMT and CD133, it also demonstrates some differences with each of these signatures that is partly due to the fact that the signatures of EMT and CD133 are inversely related to each other. Taken together this data sheds light on role of the mesenchymal transition and neural stem cells, and their mutual interaction, in molecular subtypes of glioblastoma multiforme.
Project description:The neural stem cell marker CD133 is reported to identify cells within glioblastoma (GBM) that can initiate neurosphere growth and tumor formation, however, instances of CD133- cells exhibiting similar properties have also been reported. Here, we show that some PTEN-deficient GBM tumors produce a series of CD133+ and CD133- self-renewing tumor-initiating cell types and provide evidence that these cell types constitute a lineage hierarchy. Our results show that the capacities for self-renewal and tumor initiation in GBM need not be restricted to a uniform population of stem-like cells, but can be shared by a lineage of self-renewing cell types expressing a range of markers of forebrain lineage. Keywords: Expression and copy number analysis of glioblastomas and neurosphere forming derivative cell lines of same.
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
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.