Browsing by Subject "ADAR"

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    Disruption in A-to-I Editing Levels Affects C. elegans Development More Than a Complete Lack of Editing
    (Elsevier, 2019-04) Ganem, Nabeel S.; Ben-Asher, Noa; Manning, Aidan C.; Deffit, Sarah N.; Washburn, Michael C.; Wheeler, Emily C.; Yeo, Gene W.; Ben-Naim Zgayer, Orna; Mantsur, Einav; Hundley, Heather A.; Lamm, Ayelet T.
    A-to-I RNA editing, catalyzed by ADAR proteins, is widespread in eukaryotic transcriptomes. Studies showed that, in C. elegans, ADR-2 can actively deaminate dsRNA, whereas ADR-1 cannot. Therefore, we set out to study the effect of each of the ADAR genes on the RNA editing process. We performed comprehensive phenotypic, transcriptomics, proteomics, and RNA binding screens on worms mutated in a single ADAR gene. We found that ADR-1 mutants exhibit more-severe phenotypes than ADR-2, and some of them are a result of non-editing functions of ADR-1. We also show that ADR-1 significantly binds edited genes and regulates mRNA expression, whereas the effect on protein levels is minor. In addition, ADR-1 primarily promotes editing by ADR-2 at the L4 stage of development. Our results suggest that ADR-1 has a significant role in the RNA editing process and in altering editing levels that affect RNA expression; loss of ADR-1 results in severe phenotypes.
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    Global Transcriptome Analysis of RNA Abundance Regulation by ADAR in Lung Adenocarcinoma
    (Elsevier, 2018-01) Sharpnack, Michael F.; Chen, Bin; Aran, Dvir; Kosti, Idit; Sharpnack, Douglas D.; Carbone, David P.; Mallick, Parag; Huang, Kun; Medicine, School of Medicine
    Despite tremendous advances in targeted therapies against lung adenocarcinoma, the majority of patients do not benefit from personalized treatments. A deeper understanding of potential therapeutic targets is crucial to increase the survival of patients. One promising target, ADAR, is amplified in 13% of lung adenocarcinomas and in-vitro studies have demonstrated the potential of its therapeutic inhibition to inhibit tumor growth. ADAR edits millions of adenosines to inosines within the transcriptome, and while previous studies of ADAR in cancer have solely focused on protein-coding edits, >99% of edits occur in non-protein coding regions. Here, we develop a pipeline to discover the regulatory potential of RNA editing sites across the entire transcriptome and apply it to lung adenocarcinoma tumors from The Cancer Genome Atlas. This method predicts that 1413 genes contain regulatory edits, predominantly in non-coding regions. Genes with the largest numbers of regulatory edits are enriched in both apoptotic and innate immune pathways, providing a link between these known functions of ADAR and its role in cancer. We further show that despite a positive association between ADAR RNA expression and apoptotic and immune pathways, ADAR copy number is negatively associated with apoptosis and several immune cell types' signatures.