Project description:The goal of the microarray experiment was to do a head-to-head comparison of the U1 Adaptor technology with siRNA in terms of specificity at the genome-wide level. U1 Adaptors represent a novel gene silencing method that employs a mechanism of action distinct from antisense and RNA interference (RNAi). The U1 Adaptor is a bifunctional oligonucleotide having a âTarget Domainâ that is complementary to a site in the target gene's terminal exon and a âU1 Domainâ that binds to the U1 small nuclear RNA (snRNA) component of the U1 small nuclear ribonucleoprotein (U1 snRNP) splicing factor. Tethering of U1 snRNP to the target pre-mRNA inhibits 3' end processing (i.e., polyA tail addition) leading to degradation of that RNA species within the nucleus thereby reducing mRNA levels. We demonstrate that U1 Adaptors can specifically inhibit both reporter and endogenous genes. Further, targeting the same gene either with multiple U1 Adaptors or with U1 Adaptors and small interfering RNAs (siRNAs), strongly enhances gene silencing, the latter as predicted from their distinct mechanisms of action. Such combinatorial targeting requires lower amounts of oligonucleotides to achieve potent silencing. Experiment Overall Design: For each sample total RNA was prepared from 3 independent transfections and then were pooled and analyzed by QPCR and also by microarray.
Project description:The goal of the microarray experiment was to do a head-to-head comparison of the U1 Adaptor technology with siRNA in terms of specificity at the genome-wide level. U1 Adaptors represent a novel gene silencing method that employs a mechanism of action distinct from antisense and RNA interference (RNAi). The U1 Adaptor is a bifunctional oligonucleotide having a “Target Domain” that is complementary to a site in the target gene's terminal exon and a “U1 Domain” that binds to the U1 small nuclear RNA (snRNA) component of the U1 small nuclear ribonucleoprotein (U1 snRNP) splicing factor. Tethering of U1 snRNP to the target pre-mRNA inhibits 3' end processing (i.e., polyA tail addition) leading to degradation of that RNA species within the nucleus thereby reducing mRNA levels. We demonstrate that U1 Adaptors can specifically inhibit both reporter and endogenous genes. Further, targeting the same gene either with multiple U1 Adaptors or with U1 Adaptors and small interfering RNAs (siRNAs), strongly enhances gene silencing, the latter as predicted from their distinct mechanisms of action. Such combinatorial targeting requires lower amounts of oligonucleotides to achieve potent silencing.
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: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:Gene methylation profiling of immortalized human mesenchymal stem cells comparing HPV E6/E7-transfected MSCs cells with human telomerase reverse transcriptase (hTERT)- and HPV E6/E7-transfected MSCs. hTERT may increase gene methylation in MSCs. Goal was to determine the effects of different transfected genes on global gene methylation in MSCs.
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