1,720,964 research outputs found
Ruolo deI microRNA nella patogenesi del mesotelioma maligno: un approccio basato sulle “evidenze scientifiche” e sull’analisi computazionale
Full text linkI MicroRNA (miRNAs) sono dei piccoli RNA non codificanti in grado di regolare l’espressione genica a livello post-trascrizionale. Essi hanno un ruolo fondamentale nei più svariati processi cellulari. L’espressione aberrante dei miRNA è stata correlata alla patogenesi di numerose neoplasie compreso il Mesotelioma Maligno (MM), un tumore letale correlato all’esposizione ad amianto, resistente alle terapie ad oggi disponibili. In questo studio sono state condotte una rassegna sistematica della letteratura ed una meta-analisi qualitativa per cercare di identificare i miRNA rilevanti nella diagnosi precoce del MM. E’stato identificato un gruppo di miRNA MM-associati caratterizzati da una potenziale rilevanza clinica. Essi sono stati definiti “mesomiRs” e comprendono i miR-126-3p, miR-103a-3p, miR-625-3p, circolanti ed i miR-16-5p, miR-126-3p, miR-143-3p, miR-145-5p, miR-192-5p, miR-193a-3p, miR-200b-3p, miR-203a-3p, miR-652-3p, tissutali. I mesomiRs sono stati sottoposti ad analisi bioinformatica e funzionale per individuare sia il loro ruolo giocato nella deregolazione delle vie di trasduzione del segnale alla base della patogenesi del MM, sia il loro potenziale diagnostico. In una seconda fase del lavoro, lo studio si è focalizzato sull’allestimento di un metodo sperimentale per analizzare i miRNA differenzialmente espressi tra campioni di MM tissutali e cellulari, e controlli sani. Il miR-214 si è rivelato come il più down-regolato nei campioni patologici rispetto ai controlli. L’analisi in silico di predizione dei target, corroborata dal confronto dei dati sperimentali in letteratura, ha portato all’identificazione della proteina EZH2 come target verosimile del miR-214. Questi sono la base per ulteriori studi sulle specifiche interazioni miRNA-target e i dati fornisco nuove evidenze per lo sviluppo di futuri agenti terapeutici. Questo lavoro dimostra inoltre che un approccio di data-mining ben progettato, affiancato dall’analisi bioinformatica, può svelare informazioni interessanti sui meccanismi alla base della patogenesi del MM e delle patologie dovute all’esposizione all’amianto.MicroRNAs (miRNAs) are endogenous, non-coding, small RNAs able to modulate gene expression at post-transcriptional level with a fundamental role in multiple cellular processes and regulatory pathways. Aberrantly expressed miRNAs have been correlated to the pathogenesis of numerous cancers including Malignant mesothelioma (MM). MM is an asbestos-related lethal cancer, poorly responsive to current treatments. In this study, a systematic review and a qualitative meta-analysis has been performed to identify miRNA with potential clinical relevance as early biomarkers. Notably, a gorup of high-confidence MM-associated miRNAs has been identified and called mesomiRs, namely circulating miR-126-3p, miR-103a-3p, and miR-625-3p, and tissue miR-16-5p, miR-126-3p, miR-143-3p, miR-145-5p, miR-192-5p, miR-193a-3p, miR-200b-3p, miR-203a-3p, and miR-652-3p. Subsequently, they were then subjected to bioinformatic analysis to predict their role in the disruption of key pathways involved in the pathogenesis of MM, and functional investigation confirmed their early diagnostic value. In a second step of analysis, this study focused on the establishment of an experimental method for determining differentially expressed miRNAs between MM samples and controls. MiR-214 has been highlighted as the most dowregulated miRNA in MM specimens in comparison to the control group. Finally, the combination of in silico target prediction analysis and empirical target data, has allowed the identification of EZH2, among others, as a key target gene involved in malignant transformation. These findings provide new evidence-based knowledge for cancer drug discovery. Further studies are necessary to investigate the role of miRNA-target interactions in the disruption of key signaling pathways identified. Here we demonstrated that a well settled data mining approach and bioinformatic analysis might disclose the most reliable microRNA-gene target interactions having key role in the pathogenesis of MM
Progress of research on microRNAs with diagnostic value in asbestos exposure: A call for method standardization
No full textMalignant mesothelioma (MM) is an insidious, lethal asbestos-related cancer that is poorly responsive to current treatments. Specific and sensitive biomarkers providing early MM diagnosis in exposed subjects, who are at high-risk of developing it, are sorely needed. MicroRNAs (miRNAs) are endogenous, non-coding, small RNAs with a well-established diagnostic role in cancer and pollution exposure. In a recent systematic review and qualitative meta-analysis followed by a functional investigation, we examined all the available data on the miRNA biomarkers involved in asbestos exposure and MM pathways. This invited commentary aims to provide an insightful critique into the state of the art of the research into clinically relevant miRNA biomarkers, highlighting the strengths and weaknesses of current research efforts in this field. It also reviews the suggestions advanced to improve biomarker development productivity and the translation of research results into clinical practice, stressing that multicenter multidisciplinary studies adopting standardized methods and protocol sharing are the key to move from the workbench to the clinic
Bioinformatic tools for microRNA dissection
No full textRecently, microRNAs (miRNAs) have emerged as important elements of gene regulatory networks. MiRNAs are endogenous single-stranded non-coding RNAs (∼22-nt long) that regulate gene expression at the post-transcriptional level. Through pairing with mRNA, miRNAs can down-regulate gene expression by inhibiting translation or stimulating mRNA degradation. In some cases they can also up-regulate the expression of a target gene. MiRNAs influence a variety of cellular pathways that range from development to carcinogenesis. The involvement of miRNAs in several human diseases, particularly cancer, makes them potential diagnostic and prognostic biomarkers. Recent technological advances, especially high-throughput sequencing, have led to an exponential growth in the generation of miRNA-related data. A number of bioinformatic tools and databases have been devised to manage this growing body of data. We analyze 129 miRNA tools that are being used in diverse areas of miRNA research, to assist investigators in choosing the most appropriate tools for their needs
A Practical Guide to miRNA Target Prediction
No full textMicroRNAs (miRNAs) are small endogenous noncoding RNA molecules that posttranscriptionally regulate gene expression. Since their discovery, a huge number of miRNAs have been identified in a wide range of species. Through binding to the 3' UTR of mRNA, miRNA can block translation or stimulate degradation of the targeted mRNA, thus affecting nearly all biological processes. Prediction and identification of miRNA target genes is crucial toward understanding the biology of miRNAs. Currently, a number of sophisticated bioinformatics approaches are available to perform effective prediction of miRNA target sites. In this chapter, we present the major features that most algorithms take into account to efficiently predict miRNA target: seed match, free energy, conservation, target site accessibility, and contribution of multiple binding sites. We also give an overview of the frequently used bioinformatics tools for miRNA target prediction. Understanding the basis of these prediction methodologies may help users to better select the appropriate tools and analyze their output
Diagnostic value of microRNAs in asbestos exposure and malignant mesothelioma: systematic review and qualitative meta-analysis
No full textAsbestos is a harmful and exceptionally persistent natural material. Malignant mesothelioma (MM), an asbestos-related disease, is an insidious, lethal cancer that is poorly responsive to current treatments. Minimally invasive, specific, and sensitive biomarkers providing early and effective diagnosis in high-risk patients are urgently needed. MicroRNAs (miRNAs, miRs) are endogenous, non-coding, small RNAs with established diagnostic value in cancer and pollution exposure. A systematic review and a qualitative meta-analysis were conducted to identify high-confidence miRNAs that can serve as biomarkers of asbestos exposure and MM
Mitochondrial (Dys) Function in Inflammaging: Do MitomiRs Influence the Energetic, Oxidative, and Inflammatory Status of Senescent Cells?
Full text linkA relevant feature of aging is chronic low-grade inflammation, termed inflammaging, a key process promoting the development of all major age-related diseases. Senescent cells can acquire the senescence-associated (SA) secretory phenotype (SASP), characterized by the secretion of proinflammatory factors fuelling inflammaging. Cellular senescence is also accompanied by a deep reshaping of microRNA expression and by the modulation of mitochondria activity, both master regulators of the SASP. Here, we synthesize novel findings regarding the role of mitochondria in the SASP and in the inflammaging process and propose a network linking nuclear-encoded SA-miRNAs to mitochondrial gene regulation and function in aging cells. In this conceptual structure, SA-miRNAs can translocate to mitochondria (SA-mitomiRs) and may affect the energetic, oxidative, and inflammatory status of senescent cells. We discuss the potential role of several of SA-mitomiRs (i.e., let-7b, miR-1, miR-130a-3p, miR-133a, miR-146a-5p, miR-181c-5p, and miR-378-5p), using miR-146a as a proof-of-principle model. Finally, we propose a comprehensive, metabolic, and epigenetic view of the senescence process, in order to amplify the range of possible approaches to target inflammaging, with the ultimate goal of decelerating the aging rate, postponing or blunting the development of age-related diseases
RUOLO DEI microRNA NELLA PATOGENESI DEL MESOTELIOMA MALIGNO: UN APPROCCIO BASATO SULLE “EVIDENZE SCENTIFICHE” E SULL’ANALISI COMPUTAZIONALE
No full textI MicroRNA (miRNAs) sono dei piccoli RNA non codificanti in grado di regolare l’espressione genica a livello post-trascrizionale. Essi hanno un ruolo fondamentale nei più svariati processi cellulari. L’espressione aberrante dei miRNA è stata correlata alla patogenesi di numerose neoplasie compreso il Mesotelioma Maligno (MM), un tumore letale correlato all’esposizione ad amianto, resistente alle terapie ad oggi disponibili. In questo studio sono state condotte una rassegna sistematica della letteratura ed una meta-analisi qualitativa per cercare di identificare i miRNA rilevanti nella diagnosi precoce del MM. E’stato identificato un gruppo di miRNA MM-associati caratterizzati da una potenziale rilevanza clinica. Essi sono stati definiti “mesomiRs” e comprendono i miR-126-3p, miR-103a-3p, miR-625-3p, circolanti ed i miR-16-5p, miR-126-3p, miR-143-3p, miR-145-5p, miR-192-5p, miR-193a-3p, miR-200b-3p, miR-203a-3p, miR-652-3p, tissutali. I mesomiRs sono stati sottoposti ad analisi bioinformatica e funzionale per individuare sia il loro ruolo giocato nella deregolazione delle vie di trasduzione del segnale alla base della patogenesi del MM, sia il loro potenziale diagnostico.
In una seconda fase del lavoro, lo studio si è focalizzato sull’allestimento di un metodo sperimentale per analizzare i miRNA differenzialmente espressi tra campioni di MM tissutali e cellulari, e controlli sani. Il miR-214 si è rivelato come il più down-regolato nei campioni patologici rispetto ai controlli.
L’analisi in silico di predizione dei target, corroborata dal confronto dei dati sperimentali in letteratura, ha portato all’identificazione della proteina EZH2 come target verosimile del miR-214.
Questi sono la base per ulteriori studi sulle specifiche interazioni miRNA-target e i dati fornisco nuove evidenze per lo sviluppo di futuri agenti terapeutici.
Questo lavoro dimostra inoltre che un approccio di data-mining ben progettato, affiancato dall’analisi bioinformatica, può svelare informazioni interessanti sui meccanismi alla base della patogenesi del MM e delle patologie dovute all’esposizione all’amianto
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
- …
