RNA editing is one of the most prevalent and abundant forms of post-transcriptional RNA modification observed in normal physiological processes and often aberrant in diseases including cancer. RNA editing changes the sequences of mRNAs, making them different from the source DNA sequence. Edited mRNAs can produce editing-recoded protein isoforms that are functionally different from the corresponding genome-encoded protein isoforms. The major type of RNA editing in mammals occurs by enzymatic deamination of adenosine to inosine (A-to-I) within double-stranded RNAs (dsRNAs) or hairpins in pre-mRNA transcripts. Enzymes that catalyse these processes belong to the adenosine deaminase acting on RNA (ADAR) family. The vast majority of knowledge on the RNA editing landscape relevant to human disease has been acquired using in vitro cancer cell culture models. The limitation of such in vitro models, however, is that the physiological or disease relevance of results obtained is not necessarily obvious. In this review we focus on discussing in vivo occurring RNA editing events that have been identified in human cancer tissue using samples surgically resected or clinically retrieved from patients. We discuss how RNA editing events occurring in tumours in vivo can identify pathological signalling mechanisms relevant to human cancer physiology which is linked to the different stages of cancer progression including initiation, promotion, survival, proliferation, immune escape and metastasis.

• Klíčová slova
• ADARs, RNA editing, RNA editing in cancer, cancer development,
• MeSH
• adenosin genetika   MeSH
• dvouvláknová RNA genetika   MeSH
• editace RNA * MeSH
• inosin genetika   MeSH
• karcinogeneze genetika   patologie   MeSH
• lidé MeSH
• nádory genetika   metabolismus   patologie   MeSH
• proteiny vázající RNA genetika   metabolismus   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Názvy látek
• adenosin MeSH
• dvouvláknová RNA MeSH
• inosin MeSH
• proteiny vázající RNA MeSH

We review the structures and functions of ADARs and their involvements in human diseases. ADAR1 is widely expressed, particularly in the myeloid component of the blood system, and plays a prominent role in promiscuous editing of long dsRNA. Missense mutations that change ADAR1 residues and reduce RNA editing activity cause Aicardi-Goutières Syndrome, a childhood encephalitis and interferonopathy that mimics viral infection and resembles an extreme form of Systemic Lupus Erythmatosus (SLE). In Adar1 mouse mutant models aberrant interferon expression is prevented by eliminating interferon activation signaling from cytoplasmic dsRNA sensors, indicating that unedited cytoplasmic dsRNA drives the immune induction. On the other hand, upregulation of ADAR1 with widespread promiscuous RNA editing is a prominent feature of many cancers and particular site-specific RNA editing events are also affected. ADAR2 is most highly expressed in brain and is primarily required for site-specific editing of CNS transcripts; recent findings indicate that ADAR2 editing is regulated by neuronal excitation for synaptic scaling of glutamate receptors. ADAR2 is also linked to the circadian clock and to sleep. Mutations in ADAR2 could contribute to excitability syndromes such as epilepsy, to seizures, to diseases involving neuronal plasticity defects, such as autism and Fragile-X Syndrome, to neurodegenerations such as ALS, or to astrocytomas or glioblastomas in which reduced ADAR2 activity is required for oncogenic cell behavior. The range of human disease associated with ADAR1 mutations may extend further to include other inflammatory conditions while ADAR2 mutations may affect psychiatric conditions.

• MeSH
• adenosindeaminasa * genetika   metabolismus   MeSH
• duševní poruchy * genetika   metabolismus   MeSH
• dvouvláknová RNA * genetika   metabolismus   MeSH
• editace RNA genetika   MeSH
• lidé MeSH
• mutace * MeSH
• mutantní kmeny myší MeSH
• myši MeSH
• nemoci nervového systému * genetika   metabolismus   MeSH
• proteiny vázající RNA * genetika   metabolismus   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH
• Názvy látek
• ADAR protein, human MeSH Prohlížeč
• ADAR1 protein, mouse MeSH Prohlížeč
• ADAR2 protein, mouse MeSH Prohlížeč
• ADARB1 protein, human MeSH Prohlížeč
• adenosindeaminasa * MeSH
• dvouvláknová RNA * MeSH
• proteiny vázající RNA * MeSH