Východiska: Za poslední desetiletí přibyly stovky studií, jež souhlasně prokázaly, že krátké nekódující RNA jsou slibnými diagnostickými, prognostickými a prediktivními biomarkery nádorových onemocnění. Významnou podskupinu těchto molekul představují RNA interagující s PIWI proteiny, označované jako piRNA. Tyto krátké RNA se podílejí na regulaci genové exprese na transkripční nebo post-transkripční úrovni, jejich hlavní úlohou je však epigenetické umlčování transpozibilních elementů LINE a SINE, čímž významně přispívají k udržení genomové stability. Dále se účastní důležitých buněčných procesů, jakými jsou gametogeneze, segregace chromozomů či sebeobnova kmenových buněk. Přestože byly piRNA poprvé detekovány v zárodečných buňkách, bylo zjištěno, že se vyskytují ve vysokých hladinách také v jiných lidských tkáních, přičemž jejich exprese vykazuje tkáňovou specificitu. První studie rovněž prokázaly změněný expresní profil piRNA u pacientů s nádorovými onemocněními. Funkce těchto molekul v procesu kancerogeneze však zatím zůstávají neobjasněné. Do popředí zájmu se v poslední době též dostávají volné cirkulující piRNA v tělních tekutinách, které nabízejí široké využití pro včasný záchyt nádorových onemocnění, predikci léčebné odpovědi či stanovení prognózy pacientů. Cíl: Tento přehledový článek jako první v českém jazyce shrnuje dosavadní poznatky o biogenezi piRNA, o jejich strategii při umlčování transpozibilních elementů a dalších genů. Poskytuje rovněž ucelený přehled o piRNA s deregulovanou expresí u lidských nádorových onemocnění a klade důraz na jejich potenciální diagnostické a terapeutické využití.

Background: In the past few years, a number of studies have suggested that small non-coding RNAs could be promising diagnostic, prognostic and predictive biomarkers in oncology. Recently, small RNAs interacting with PIWI proteins (piRNAs) have been described. These small RNAs regulate gene expression at transcriptional and post-transcriptional levels; however, they appear to be specifically involved in silencing the transposable elements LINE and SINE and are thus considered to contribute to genomic stability. Furthermore, piRNAs participate also in other important biological processes, such as gametogenesis, chromosome segregation, and stem cell self-renewal. Although their expression was first noted in germ line cells, they are now known to be present in all tissue types and their expression is highly tissue-specific. In addition, piRNA expression is dysregulated in tumor tissues. Nevertheless, the exact function of these molecules in cancerogenesis is not known. Recently, free circulating piRNAs were reported to be stably present in body fluids, suggesting that they could serve as promising noninvasive biomarkers to enable early diagnosis, therapy response prediction, and accurate prognosis prediction of cancer patients. Aim: The aim of this review is to summarize current knowledge about piRNA biogenesis and their functions in the regulation of gene expression and transposons silencing. In addition, the review focuses on piRNAs that show dysregulated expression in different types of cancers and that could serve as potential diagnostic biomarkers and/or therapeutic targets.

• Klíčová slova
• umlčování transpozonů,
• MeSH
• biogeneze organel MeSH
• karcinogeneze MeSH
• lidé MeSH
• malá interferující RNA * MeSH
• nádorové biomarkery genetika   MeSH
• nádory * diagnóza   genetika   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• práce podpořená grantem MeSH
• přehledy MeSH

PIWI-interacting RNAs (piRNAs) play a crucial role in safeguarding genome integrity by silencing mobile genetic elements. From flies to humans, piRNAs originate from long single-stranded precursors encoded by genomic piRNA clusters. How piRNA clusters form to adapt to genomic invaders and evolve to maintain protection remain key outstanding questions. Here, we generate a roadmap of piRNA clusters across seven species that highlights both similarities and variations. In mammals, we identify transcriptional readthrough as a mechanism to generate piRNAs from transposon insertions (piCs) downstream of genes (DoG). Together with the well-known stress-dependent DoG transcripts, our findings suggest a molecular mechanism for the formation of piRNA clusters in response to retroviral invasion. Finally, we identify a class of dynamic piRNA clusters in humans, underscoring unique features of human germ cell biology. Our results advance the understanding of conserved principles and species-specific variations in piRNA biology and provide tools for future studies.

• MeSH
• druhová specificita MeSH
• lidé MeSH
• malá interferující RNA * metabolismus   genetika   MeSH
• myši MeSH
• Piwi-interagující RNA MeSH
• psi MeSH
• savci * genetika   MeSH
• transpozibilní elementy DNA genetika   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• psi MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• srovnávací studie MeSH

OBJECTIVE: The PIWIL (P-element induced wimpy testis like protein) subfamily of argonaute proteins is essential for Piwi-interacting RNA (piRNA) biogenesis and their function to silence transposons during germ-line development. Here we explored their presence and regulation in rheumatoid arthritis (RA). METHODS: The expression of PIWIL genes in RA and osteoarthritis (OA) synovial tissues and synovial fibroblasts (SF) was analysed by Real-time PCR, immunofluorescence and Western blot. The expression of piRNAs was quantified by next generation small RNA sequencing (NGS). The regulation of PIWI/piRNAs, proliferation and methylation of LINE-1 after silencing of PIWIL genes were studied. RESULTS: PIWIL2 and 4 mRNA were similarly expressed in synovial tissues and SF from RA and OA patients. However, on the protein level only PIWIL4 was strongly expressed in SF. Using NGS up to 300 piRNAs were identified in all SF without significant differences in expression levels between RA and OASF. Of interest, the analysis of the co-expression of the detected piRNAs revealed a less tightly regulated pattern of piRNA-823, -4153 and -16659 expression in RASF. In RASF and OASF, stimulation with TNFα+IL1β/TLR-ligands further significantly increased the expression levels of PIWIL2 and 4 mRNA and piRNA-16659 was significantly (4-fold) induced upon Poly(I:C) stimulation. Silencing of PIWIL2/4 neither affect LINE-1 methylation/expression nor proliferation of RASF. CONCLUSION: We detected a new class of small regulatory RNAs (piRNAs) and their specific binding partners (PIWIL2/4) in synovial fibroblasts. The differential regulation of co-expression of piRNAs in RASF and the induction of piRNA/Piwi-proteins by innate immune stimulators suggest a role in inflammatory processes.

• MeSH
• Argonaut proteiny genetika   metabolismus   MeSH
• cytokiny metabolismus   MeSH
• dlouhé rozptýlené jaderné elementy MeSH
• fibroblasty patologie   MeSH
• lidé středního věku MeSH
• lidé MeSH
• malá interferující RNA metabolismus   MeSH
• osteoartróza genetika   metabolismus   patologie   MeSH
• proteiny genetika   metabolismus   MeSH
• regulace genové exprese MeSH
• revmatoidní artritida genetika   metabolismus   patologie   MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• synoviální membrána patologie   MeSH
• Check Tag
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

BACKGROUND: Myelodysplastic neoplasms (MDS) are heterogeneous hematopoietic disorders characterized by ineffective hematopoiesis and genome instability. Mobilization of transposable elements (TEs) is an important source of genome instability leading to oncogenesis, whereas small PIWI-interacting RNAs (piRNAs) act as cellular suppressors of TEs. However, the roles of TEs and piRNAs in MDS remain unclear. METHODS: In this study, we examined TE and piRNA expression through parallel RNA and small RNA sequencing of CD34+ hematopoietic stem cells from MDS patients. RESULTS: Comparative analysis of TE and piRNA expression between MDS and control samples revealed several significantly dysregulated molecules. However, significant differences were observed between lower-risk MDS (LR-MDS) and higher-risk MDS (HR-MDS) samples. In HR-MDS, we found an inverse correlation between decreased TE levels and increased piRNA expression and these TE and piRNA levels were significantly associated with patient outcomes. Importantly, the upregulation of PIWIL2, which encodes a key factor in the piRNA pathway, independently predicted poor prognosis in MDS patients, underscoring its potential as a valuable disease marker. Furthermore, pathway analysis of RNA sequencing data revealed that dysregulation of the TE‒piRNA axis is linked to the suppression of processes related to energy metabolism, the cell cycle, and the immune response, suggesting that these disruptions significantly affect cellular activity. CONCLUSIONS: Our findings demonstrate the parallel dysregulation of TEs and piRNAs in HR-MDS patients, highlighting their potential role in MDS progression and indicating that the PIWIL2 level is a promising molecular marker for prognosis.

• Publikační typ
• časopisecké články MeSH

Osteoarthritis (OA) is a frequent musculoskeletal disorder affecting millions of people worldwide. Despite advances in understanding the pathogenesis of OA, prognostic biomarkers or effective targeted treatment are not currently available. Research on epigenetic factors has yielded some new insights as new technologies for their detection continue to emerge. In this context, non-coding RNAs, including microRNAs, long non-coding RNAs, circular RNAs, piwi-interacting RNAs, and small nucleolar RNAs, regulate intracellular signaling pathways and biological processes that have a crucial role in the development of several diseases. In this review, we present current knowledge on the role of epigenetic factors with a focus on non-coding RNAs in the development, prediction and treatment of OA. This article is categorized under: RNA in Disease and Development > RNA in Disease.

• MeSH
• kruhová RNA MeSH
• lidé MeSH
• mikro RNA * genetika   MeSH
• osteoartróza * genetika   MeSH
• Piwi-interagující RNA MeSH
• RNA dlouhá nekódující * genetika   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH

Background: The early detection of colon cancer is one of the main prerequisites for successful treatment and mortality reduction. Circulating PIWI-interacting RNAs (piRNA) were recently identified as novel promising biomarkers. The purpose of the study was to assess the profiles of piRNAs in blood serum of colon cancer patients with the aim to identify those with high diagnostic potential.Methods: Blood serum samples from 403 colon cancer patients and 276 healthy donors were included in this 3-phase biomarker study. Large-scale piRNA expression profiling was performed using Illumina small RNA sequencing. The diagnostic potential of selected piRNAs was further validated on independent training and validation sets of samples using RT-qPCR.Results: In total, 31 piRNAs were found to be significantly deregulated in serum of cancer patients compared with healthy donors. Based on the levels of piR-5937 and piR-28876, it was possible to differentiate between cancer patients and healthy donors with high sensitivity and specificity. Moreover, both piRNAs exhibited satisfactory diagnostic performance also in patients with stage I disease and enabled detection of colon cancer with higher sensitivity than currently used biomarkers CEA and CA19-9. Finally, the expression of analyzed piRNAs in blood restored significantly 1 month after the surgical resection.Conclusions: Based on our findings, piRNAs are abundant in human blood serum. Furthermore, their levels in colon cancer have been observed to be significantly deregulated. However, their involvement in carcinogenesis must be further established.Impact: piRNAs could serve as promising noninvasive biomarkers for early detection of colon cancer. Cancer Epidemiol Biomarkers Prev; 27(9); 1019-28. ©2018 AACR.

• MeSH
• lidé středního věku MeSH
• lidé MeSH
• malá interferující RNA genetika   MeSH
• nádorové biomarkery genetika   MeSH
• nádory tračníku diagnóza   genetika   MeSH
• následné studie MeSH
• prognóza MeSH
• regulace genové exprese u nádorů * MeSH
• senioři MeSH
• studie případů a kontrol MeSH
• Check Tag
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Our current understanding of hematopoietic stem cell differentiation and the abnormalities that lead to leukemogenesis originates from the accumulation of knowledge regarding protein-coding genes. However, the possible impact of transposable element (TE) mobilization and the expression of P-element-induced WImpy testis-interacting RNAs (piRNAs) on leukemogenesis has been beyond the scope of scientific interest to date. The expression profiles of these molecules and their importance for human health have only been characterized recently due to the rapid progress of high-throughput sequencing technology development. In the present review, current knowledge on the expression profile and function of TEs and piRNAs was summarized, with specific focus on their reported involvement in leukemogenesis and pathogenesis of myelodysplastic syndrome.

• MeSH
• lidé MeSH
• malá interferující RNA genetika   MeSH
• myelodysplastické syndromy genetika   patologie   MeSH
• transpozibilní elementy DNA * MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

Glioblastoma (GBM) is the most frequently occurring primary malignant brain tumor of astrocytic origin. To change poor prognosis, it is necessary to deeply understand the molecular mechanisms of gliomagenesis and identify new potential biomarkers and therapeutic targets. PIWI-interacting RNAs (piRNAs) help in maintaining genome stability, and their deregulation has already been observed in many tumors. Recent studies suggest that these molecules could also play an important role in the glioma biology. To determine GBM-associated piRNAs, we performed small RNA sequencing analysis in the discovery set of 19 GBM and 11 non-tumor brain samples followed by TaqMan qRT-PCR analyses in the independent set of 77 GBM and 23 non-tumor patients. Obtained data were subsequently bioinformatically analyzed. Small RNA sequencing revealed 58 significantly deregulated piRNA molecules in GBM samples in comparison with non-tumor brain tissues. Deregulation of piR-1849, piR-9491, piR-12487, and piR-12488 was successfully confirmed in the independent groups of patients and controls (all p < 0.0001), and piR-9491 and piR-12488 reduced GBM cells' ability to form colonies in vitro. In addition, piR-23231 was significantly associated with the overall survival of the GBM patients treated with Stupp regimen (p = 0.007). Our results suggest that piRNAs could be a novel promising diagnostic and prognostic biomarker in GBM potentially playing important roles in gliomagenesis.

• Publikační typ
• časopisecké články MeSH

Glioblastoma (GBM) is the most frequent primary brain tumor of astrocytic origin. Despite great advances in molecular pathology and oncology, there is still no clinically applicable ways to classify patients according their prognosis and to overcome GBM resistance to the conventional therapy, respectively. This results in an early tumor recurrence and dismal survival of GBM patients. Biological behavior of GBM is largely linked to the presence of glioblastoma stem cells (GSCs), a cell subpopulation displaying features of pluripotent stem cells among which belongs also the ability to maintain genomic stability constantly disturbed by transposable elements (TEs). Regulation of TEs in stem cells is managed mainly by PIWI-interacting RNAs (piRNAs). Deregulated levels of these small RNAs have been also observed in many cancers including cancer stem cells suggesting their important role in cancerogenesis. Deeper understanding of piRNA roles in GSCs could led to the first step to both development of new therapeutic targets and discovery new prognostic biomarkers in GBM patients.

Glioblastom (GBM) je nejčastěji se vyskytující primární nádor mozku astrocytárního původu. Navzdory pokrokům v oblasti molekulární patologie a onkologie stále neexistují klinicky využitelné přístupy umožňující jednak klasifikovat pacienty dle jejich prognózy, ani překonat rezistenci GBM vůči konvenční terapii. To vede k časným relapsům a krátkému přežívání pacientů s GBM. Biologické chování GBM je dáváno do souvislosti s přítomností glioblastomových kmenových buněk (GSC), subpopulace vyznačující se vlastnostmi pluripotentních kmenových buněk, mezi které patří i schopnost udržovat genomovou stabilitu neustále narušovanou transponovatelnými elementy (TE). U kmenových buněk je regulace TE zprostředkovávána především PIWI-interagujícími RNA (piRNA). Deregulované hladiny těchto krátkých RNA byly pozorovány u mnoha nádorových onemocnění, včetně nádorových kmenových buněk, což naznačuje jejich významnou úlohu v kancerogenezi. Hlubší pochopení role piRNA u GSC by tak mohlo vést jak k vývoji nových terapeutických cílů, tak k objevení nových prognostických biomarkerů u pacientů s GBM.

• Klíčová slova
• prognóza, prognosis, léčba, therapy, glioblastoma, glioblastom, PIWI-interagující RNA, glioblastomové kmenové buňky, PIWI-interacting RNA, glioblastoma stem cells,

• NLK Publikační typ
• závěrečné zprávy o řešení grantu AZV MZ ČR

BACKGROUND: Renal cell carcinoma (RCC) is the most common neoplasm of adult kidney accounting for about 3% of adult malignancies. P-Element induced wimpy testis (PIWI)-interacting RNAs (piRNAs) are a new class of naturally occurring, short non-coding RNAs involved in silencing of transposable elements and in sequence-specific chromatin modifications. There were preliminary data published indicating that piR-823 expression is deregulated in circulating tumor cells and tumor tissue in gastric and kidney cancer, respectively. PATIENTS AND METHODS: In our study, we analyzed piR-823 levels in 588 biological specimens: tumor tissue (N=153), adjacent renal parenchyma (N=121), blood serum (N=178) and urine (N=20) of patients undergoing nephrectomy for RCC; and in blood serum (N=101) and urine (N=15) of matched healthy controls. Expression levels of piR-823 were determined in all biological specimens by quantitative real-time polymerase chain reaction, compared in patients and controls, and correlated with clinicopathological features of RCC. RESULTS: We identified a significant down-regulation of piR-823 in tumor tissue [p<0.0001, area under the curve (AUC)=0.7945]. On the contrary in blood serum and urine, the expression of piR-823 was significantly higher in patients with RCC compared to healthy individuals (p=0.0005, AUC=0.6264 and p=0.0157, AUC=0.7433, respectively). We further observed higher levels of piR-823 in tumor tissue to be associated with shorter disease-free survival of patients (p=0.0186) and a trend for higher piR-823 levels in serum to be associated with advanced clinical stages of RCC (p=0.0691). There were no other significant associations of piR-823 levels in any type of biological specimen with clinicopathological features of RCC. CONCLUSION: piR-823 is down-regulated in tumor tissue, but positively correlated with worse outcome, indicating its complex role in RCC pathogenesis. In blood serum, piR-823 is up-regulated, but with unsatisfactory analytical performance. Preliminary data indicate the promising diagnostic utility of urinary piR-823 in patients with RCC.

• MeSH
• dospělí MeSH
• karcinom z renálních buněk krev   genetika   moč   MeSH
• lidé středního věku MeSH
• lidé MeSH
• malá interferující RNA krev   metabolismus   moč   MeSH
• mladý dospělý MeSH
• nádorové biomarkery krev   genetika   moč   MeSH
• nádory ledvin krev   genetika   moč   MeSH
• plocha pod křivkou MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladý dospělý MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• Publikační typ
• časopisecké články MeSH