Lidský genom obsahuje asi 22 000 protein kódujících genů, které dávají vznik ještě většímu množství messengerové RNA (mRNA). Výsledky projektu ENCODE z roku 2012 však ukazují, že byť je až 90 % našeho genomu aktivně přepisováno, tak mRNA dávající vznik proteinům tvoří pouze 2–3 % z celkového množství přepsané RNA. Zbývající RNA transkripty nedávají vznik proteinům a nesou proto označení „nekódující RNA“. Dříve se nekódující RNA považovala za „temnou hmotu genomu“, nebo za „odpad“, který se v naší DNA nahromadil v průběhu evoluce. Dnes již víme, že nekódující RNA plní v našem těle celou řadu regulačních funkcí – zasahují do epigenetických procesů od remodelace chromatinu k metylaci histonů, nebo do vlastního procesu transkripce, či do posttranskripčních procesů. Dlouhé nekódující RNA (lncRNA) jsou jednou ze tříd nekódujících RNA s délkou nad 200 nukleotidů (nekódující RNA s délkou pod 200 nukleotidů označujeme jako krátké nekódující RNA). lncRNA představují velice pestrou a rozsáhlou skupinu molekul s rozličnými regulačními funkcemi. Můžeme je identifkovat ve všech myslitelných buněčných typech, či tkáních, nebo dokonce v extracelulárním prostoru, a to včetně krve, potažmo plazmy. Jejich hladiny se mění v průběhu organogeneze, jsou specifické pro jednotlivé tkáně a k jejich změnám dochází i při vzniku různých onemocnění, včetně aterosklerózy. Cílem tohoto souhrnného článku je jednak představit problematiku lncRNA a některé jejich konkrétní zástupce ve vztahu k procesu aterosklerózy (popsat zapojení lncRNA do biologie endotelových buněk, hladkosvalových buněk cévní stěny, či buněk imunitních), a dále poukázat na možný klinický potenciál lncRNA, ať již v diagnostice či terapii aterosklerózy a jejích klinických manifestací.
The human genome contains about 22 000 protein-coding genes that are transcribed to an even larger amount of messenger RNAs (mRNA). Interestingly, the results of the project ENCODE from 2012 show, that despite up to 90 % of our genome being actively transcribed, protein-coding mRNAs make up only 2–3 % of the total amount of the transcribed RNA. The rest of RNA transcripts is not translated to proteins and that is why they are referred to as “non-coding RNAs”. Earlier the non-coding RNA was considered “the dark matter of genome”, or “the junk”, whose genes has accumulated in our DNA during the course of evolution. Today we already know that non-coding RNAs fulfil a variety of regulatory functions in our body – they intervene into epigenetic processes from chromatin remodelling to histone methylation, or into the transcription process itself, or even post-transcription processes. Long non-coding RNAs (lncRNA) are one of the classes of non-coding RNAs that have more than 200 nucleotides in length (non-coding RNAs with less than 200 nucleotides in length are called small non-coding RNAs). lncRNAs represent a widely varied and large group of molecules with diverse regulatory functions. We can identify them in all thinkable cell types or tissues, or even in an extracellular space, which includes blood, specifically plasma. Their levels change during the course of organogenesis, they are specific to different tissues and their changes also occur along with the development of different illnesses, including atherosclerosis. This review article aims to present lncRNAs problematics in general and then focuses on some of their specific representatives in relation to the process of atherosclerosis (i.e. we describe lncRNA involvement in the biology of endothelial cells, vascular smooth muscle cells or immune cells), and we further describe possible clinical potential of lncRNA, whether in diagnostics or therapy of atherosclerosis and its clinical manifestations.
- MeSH
- Atherosclerosis * physiopathology MeSH
- Endothelium physiology MeSH
- Gene Expression MeSH
- Humans MeSH
- RNA, Long Noncoding * physiology classification MeSH
- Check Tag
- Humans MeSH
- Publication type
- Research Support, Non-U.S. Gov't MeSH
- Review MeSH
For the many years, the central dogma of molecular biology has been that RNA functions mainly as an informational intermediate between a DNA sequence and its encoded protein. But one of the great surprises of modern biology was the discovery that protein-coding genes represent less than 2% of the total genome sequence, and subsequently the fact that at least 90% of the human genome is actively transcribed. Thus, the human transcriptome was found to be more complex than a collection of protein-coding genes and their splice variants. Although initially argued to be spurious transcriptional noise or accumulated evolutionary debris arising from the early assembly of genes and/or the insertion of mobile genetic elements, recent evidence suggests that the non-coding RNAs (ncRNAs) may play major biological roles in cellular development, physiology and pathologies. NcRNAs could be grouped into two major classes based on the transcript size; small ncRNAs and long ncRNAs. Each of these classes can be further divided, whereas novel subclasses are still being discovered and characterized. Although, in the last years, small ncRNAs called microRNAs were studied most frequently with more than ten thousand hits at PubMed database, recently, evidence has begun to accumulate describing the molecular mechanisms by which a wide range of novel RNA species function, providing insight into their functional roles in cellular biology and in human disease. In this review, we summarize newly discovered classes of ncRNAs, and highlight their functioning in cancer biology and potential usage as biomarkers or therapeutic targets.
BACKGROUND: The first systematic study of small non-coding RNAs (sRNA, ncRNA) in Streptomyces is presented. Except for a few exceptions, the Streptomyces sRNAs, as well as the sRNAs in other genera of the Actinomyces group, have remained unstudied. This study was based on sequence conservation in intergenic regions of Streptomyces, localization of transcription termination factors, and genomic arrangement of genes flanking the predicted sRNAs. RESULTS: Thirty-two potential sRNAs in Streptomyces were predicted. Of these, expression of 20 was detected by microarrays and RT-PCR. The prediction was validated by a structure based computational approach. Two predicted sRNAs were found to be terminated by transcription termination factors different from the Rho-independent terminators. One predicted sRNA was identified computationally with high probability as a Streptomyces 6S RNA. Out of the 32 predicted sRNAs, 24 were found to be structurally dissimilar from known sRNAs. CONCLUSION: Streptomyces is the largest genus of Actinomyces, whose sRNAs have not been studied. The Actinomyces is a group of bacterial species with unique genomes and phenotypes. Therefore, in Actinomyces, new unique bacterial sRNAs may be identified. The sequence and structural dissimilarity of the predicted Streptomyces sRNAs demonstrated by this study serve as the first evidence of the uniqueness of Actinomyces sRNAs.
- MeSH
- Algorithms MeSH
- RNA, Bacterial genetics chemistry MeSH
- Species Specificity MeSH
- Financing, Organized MeSH
- Genome, Bacterial MeSH
- DNA, Intergenic MeSH
- Nucleic Acid Conformation MeSH
- Models, Molecular MeSH
- RNA, Untranslated genetics chemistry MeSH
- Reverse Transcriptase Polymerase Chain Reaction MeSH
- Base Sequence MeSH
- Oligonucleotide Array Sequence Analysis MeSH
- Streptomyces coelicolor genetics MeSH
- Streptomyces genetics MeSH
- Terminator Regions, Genetic MeSH
- Computational Biology MeSH
The majority of the human genome encodes RNAs that do not code for proteins. These non-coding RNAs (ncRNAs) affect normal expression of the genes, including oncogenes and tumour suppressive genes, which make them a new class of targets for drug development in cancer. Although microRNAs (miRNAs) are the most studied regulatory ncRNAs to date, and miRNA-targeted therapeutics have already reached clinical development, including the mimics of the tumour suppressive miRNAs miR-34 and miR-16, which reached phase I clinical trials for the treatment of liver cancer and mesothelioma, the importance of long non-coding RNAs (lncRNAs) is increasingly being recognised. Here, we describe obstacles and advances in the development of ncRNA therapeutics and provide the comprehensive overview of the ncRNA chemistry and delivery technologies. Furthermore, we summarise recent knowledge on the biological functions of miRNAs and their involvement in carcinogenesis, and discuss the strategies of their therapeutic manipulation in cancer. We review also the emerging insights into the role of lncRNAs and their potential as targets for novel treatment paradigms. Finally, we provide the up-to-date summary of clinical trials involving miRNAs and future directions in the development of ncRNA therapeutics.
- MeSH
- Molecular Targeted Therapy methods trends MeSH
- Humans MeSH
- MicroRNAs genetics MeSH
- Models, Genetic MeSH
- Neoplasms drug therapy genetics MeSH
- RNA, Untranslated genetics MeSH
- Antineoplastic Agents therapeutic use MeSH
- Gene Expression Regulation, Neoplastic drug effects MeSH
- RNA, Long Noncoding genetics MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Review MeSH
Over a half of mammalian genomes is occupied by repetitive elements whose ability to provide functional sequences, move into new locations, and recombine underlies the so-called genome plasticity. At the same time, mobile elements exemplify selfish DNA, which is expanding in the genome at the expense of the host. The selfish generosity of mobile genetic elements is in the center of research interest as it offers insights into mechanisms underlying evolution and emergence of new genes. In terms of numbers, with over 20,000 in count, protein-coding genes make an outstanding >2 % minority. This number is exceeded by an ever-growing list of genes producing long non-coding RNAs (lncRNAs), which do not encode for proteins. LncRNAs are a dynamically evolving population of genes. While it is not yet clear what fraction of lncRNAs represents functionally important ones, their features imply that many lncRNAs emerge at random as new non-functional elements whose functionality is acquired through natural selection. Here, we explore the intersection of worlds of mobile genetic elements (particularly retrotransposons) and lncRNAs. In addition to summarizing essential features of mobile elements and lncRNAs, we focus on how retrotransposons contribute to lncRNA evolution, structure, and function in mammals.
- MeSH
- Humans MeSH
- Evolution, Molecular MeSH
- Mice MeSH
- Retroelements genetics MeSH
- RNA, Long Noncoding genetics metabolism MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Mice MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Review MeSH
Non-coding RNAs (ncRNAs) are nucleotide sequences that are known to assume regulatory roles previously thought to be reserved for proteins. Their functions include the regulation of protein activity and localization and the organization of subcellular structures. Sequencing studies have now identified thousands of ncRNAs encoded within the prokaryotic and eukaryotic genomes, leading to advances in several fields including parasitology. ncRNAs play major roles in several aspects of vector-host-pathogen interactions. Arthropod vector ncRNAs are secreted through extracellular vesicles into vertebrate hosts to counteract host defense systems and ensure arthropod survival. Conversely, hosts can use specific ncRNAs as one of several strategies to overcome arthropod vector invasion. In addition, pathogens transmitted through vector saliva into vertebrate hosts also possess ncRNAs thought to contribute to their pathogenicity. Recent studies have addressed ncRNAs in vectors or vertebrate hosts, with relatively few studies investigating the role of ncRNAs derived from pathogens and their involvement in establishing infections, especially in the context of vector-borne diseases. This Review summarizes recent data focusing on pathogen-derived ncRNAs and their role in modulating the cellular responses that favor pathogen survival in the vertebrate host and the arthropod vector, as well as host ncRNAs that interact with vector-borne pathogens.
Východiska: Glioblastom (GBM) je nejčastější primární nádor mozku, který je charakterizován nepříznivou prognózou i navzdory veškeré dostupné léčbě. Z tohoto důvodu je vynaloženo mnoho finančních prostředků a úsilí do výzkumu nových prognostických a prediktivních biomarkerů či terapeutických cílů. Dlouhé nekódující RNA (long non-coding – lncRNA) jsou regulátory genové exprese, které hrají významnou roli v patologii GBM, a zdají se proto být vhodnými kandidáty ke studiu. Materiál a metody: Naše studie zahrnovala 14 pacientů s GBM a 8 pacientů s intraktabilní epilepsií, kterým byla odebrána mozková tkáň v rámci epileptochirurgických výkonů. Ribozomální RNA depletovaná RNA byla použita na sekvenování pomocí přístroje NextSeq 500 (Illumina). Statistickou analýzou bylo vyhodnoceno 24 087 mRNA a 8 414 lncRNA a jejich sekvenčních variant s nenulovým RPKM (počet readů na kilobázi na milión mapovaných readů) alespoň v jednom vzorku. Pro mapování sekvencí na referenční genom a součet čtení připadajících na cílovou sekvenci byl použit CLC Genomic Workbench. Cílené utlumení zvýšené exprese ZFAS1 bylo provedeno pomocí tranzientní transfekce specifické skupiny dvouvláknových RNA (small interfering – siRNA) do stabilních GBM linií (A172, U87MG, T98G). Úspěšnost transfekce byla ověřena prostřednictvím kvantitativní real-time polymerázové řetězové reakce a vliv na viabilitu pomocí MTT assay. Výsledky: Statistickou analýzou bylo objeveno 274 (p < 0,01) lncRNA dysregulovaných ve tkáňových vzorcích GBM v porovnání s nenádorovými mozkovými tkáněmi. Sekvenování taktéž odhalilo 489 dysregulovaných mRNA (p < 0,001) a 26 mRNA (p < 0,000001). Transfekce inhibitoru ZFAS1, jedné z identifikovaných lncRNA, vedla k úspěšnému utlumení hladiny ZFAS1, které ovšem nemělo vliv na snížení míry proliferace buněčných linií. Závěr: Popsali jsme významnou dysregulaci lncRNA a mRNA ve tkáních GBM v porovnání s nenádorovou tkání. Dále jsme úspěšně utlumili hladinu ZFAS1, což ovšem nemělo vliv na proliferaci glioblastomových buněk.
Background: Glioblastoma (GBM) is the most frequent primary brain tumor characterized by an unfavourable prognosis despite multimodal therapy. Therefore, a lot of efforts and financial resources are dedicated to the research of new therapeutic targets and prognostic or predictive biomarkers. Long non-coding RNAs (lncRNAs) are regulators of gene expression which play a significant role in GBM pathology and, thus, present promising candidates. Material and Methods: Our study included 14 patients with GBM and 8 patients with intractable epilepsy from whom we acquired brain tissues during surgical intervention. Ribosomal RNA depleted RNA was used for sequencing by NextSeq 500 instrument (Illumina). Statistical analysis evaluated 24,087 protein-coding and 8,414 non-coding RNAs and their sequential variants with non-zero reads per kilobase per million mapped reads (RPKM) at least in one sample. CLC Genomic Workbench was used for the alignment and target counts. Targeted downregulation of up-regulated ZFAS1, one of the identified lncRNA, level has been carried out by the transient transfection of specific small interfering RNA (siRNA) in GBM stable cell lines (A172, U87MG, T98G). The success of transfection and viability were analyzed in vitro using quantitative real time polymerase chain reaction and MTT assay, resp. Results: Statistical analysis has revealed 274 (p < 0.01) dysregulated lncRNAs in GBMs in comparison with non-tumor brain tissues. Moreover, the results have showed 489 dysregulated mRNAs (p < 0.0001) and 26 mRNAs (p < 0.000001). Transfection of ZFAS1 inhibitor led to successful downregulation of ZFAS1 expression level, although it did not have a significant effect on proliferation of GBM cells. Conclusion: We described a significant dysregulation of lncRNAs and mRNAs in GBM tissue in comparison with non-tumor tissue. We also succesfully decreased expression level of ZFAS1, which in turn, however, had no impact on the viability of GBM cell lines.
- MeSH
- Glioblastoma * genetics MeSH
- Real-Time Polymerase Chain Reaction MeSH
- Humans MeSH
- Biomarkers, Tumor genetics MeSH
- Brain Neoplasms genetics MeSH
- RNA, Long Noncoding * genetics MeSH
- High-Throughput Nucleotide Sequencing MeSH
- Check Tag
- Humans MeSH
- Publication type
- Research Support, Non-U.S. Gov't MeSH
The oocyte-to-embryo transition (OET) transforms a differentiated gamete into pluripotent blastomeres. The accompanying maternal-zygotic RNA exchange involves remodeling of the long non-coding RNA (lncRNA) pool. Here, we used next generation sequencing and de novo transcript assembly to define the core population of 1,600 lncRNAs expressed during the OET (lncRNAs). Relative to mRNAs, OET lncRNAs were less expressed and had shorter transcripts, mainly due to fewer exons and shorter 5' terminal exons. Approximately half of OET lncRNA promoters originated in retrotransposons suggesting their recent emergence. Except for a small group of ubiquitous lncRNAs, maternal and zygotic lncRNAs formed two distinct populations. The bulk of maternal lncRNAs was degraded before the zygotic genome activation. Interestingly, maternal lncRNAs seemed to undergo cytoplasmic polyadenylation observed for dormant mRNAs. We also identified lncRNAs giving rise to trans-acting short interfering RNAs, which represent a novel lncRNA category. Altogether, we defined the core OET lncRNA transcriptome and characterized its remodeling during early development. Our results are consistent with the notion that rapidly evolving lncRNAs constitute signatures of cells-of-origin while a minority plays an active role in control of gene expression across OET. Our data presented here provide an excellent source for further OET lncRNA studies.
- MeSH
- Blastomeres metabolism MeSH
- Embryo, Mammalian metabolism MeSH
- Mice MeSH
- Oocytes metabolism MeSH
- RNA, Long Noncoding genetics metabolism MeSH
- Sequence Analysis, RNA MeSH
- Gene Expression Profiling MeSH
- High-Throughput Nucleotide Sequencing MeSH
- Gene Expression Regulation, Developmental * MeSH
- Animals MeSH
- Check Tag
- Mice MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
Non-coding RNAs (ncRNAs) are regulatory molecules encoded in the intergenic or intragenic regions of the genome. In prokaryotes, biocomputational identification of homologs of known ncRNAs in other species often fails due to weakly evolutionarily conserved sequences, structures, synteny and genome localization, except in the case of evolutionarily closely related species. To eliminate results from weak conservation, we focused on RNA structure, which is the most conserved ncRNA property. Analysis of the structure of one of the few well-studied bacterial ncRNAs, 6S RNA, demonstrated that unlike optimal and consensus structures, suboptimal structures are capable of capturing RNA homology even in divergent bacterial species. A computational procedure for the identification of homologous ncRNAs using suboptimal structures was created. The suggested procedure was applied to strongly divergent bacterial species and was capable of identifying homologous ncRNAs.
- MeSH
- RNA, Bacterial chemistry MeSH
- Nucleic Acid Conformation MeSH
- Molecular Sequence Data MeSH
- Mycobacterium genetics MeSH
- RNA, Untranslated chemistry MeSH
- Base Sequence MeSH
- Sequence Homology, Nucleic Acid MeSH
- Streptomyces genetics MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
A colorectal adenoma, an aberrantly growing tissue, arises from the intestinal epithelium and is considered as precursor of colorectal cancer (CRC). In this study, we investigated structural and numerical chromosomal aberrations in adenomas, hypothesizing that chromosomal instability (CIN) occurs early in adenomas. We applied array comparative genomic hybridization (aCGH) to fresh frozen colorectal adenomas and their adjacent mucosa from 16 patients who underwent colonoscopy examination. In our study, histologically similar colorectal adenomas showed wide variability in chromosomal instability. Based on the obtained results, we further stratified patients into four distinct groups. The first group showed the gain of MALAT1 and TALAM1, long non-coding RNAs (lncRNAs). The second group involved patients with numerous microdeletions. The third group consisted of patients with a disrupted karyotype. The fourth group of patients did not show any CIN in adenomas. Overall, we identified frequent losses in genes, such as TSC2, COL1A1, NOTCH1, MIR4673, and GNAS, and gene gain containing MALAT1 and TALAM1. Since long non-coding RNA MALAT1 is associated with cancer cell metastasis and migration, its gene amplification represents an important event for adenoma development.
- MeSH
- Adenoma * genetics pathology MeSH
- Chromosomal Instability MeSH
- Colorectal Neoplasms * genetics pathology MeSH
- Humans MeSH
- Precancerous Conditions * genetics pathology MeSH
- RNA, Long Noncoding * genetics MeSH
- Comparative Genomic Hybridization MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
