scholarly journals Non-randomness distribution of micro-RNAs on human chromosomes

Author(s):  
Fariba Boroumand ◽  
Iraj Saadat ◽  
Mostafa Saadat

Abstract Background Micro-RNA (miRNA) is one of the non-coding RNAs that exist in human genome. miRNAs play an important role in the expression of target genes. Several studies have indicated that organization of human genome is not random. In order to investigate the distribution of miRNAs on human chromosomes, the present study was carried out. Results Using the data from miRBase database, we found 1913 loci coding for miRNAs (MIRs). Human chromosome bands 1p36, 1q22, 1q24, 2q13, 2q35, 3p21, 6p21, 7q22, 8p23, 8q24, 9q22, 9q34, 11q12-q13, 12q13, 14q32, 16p13, 16q24, 17p13, 17q11, 17q21, 17q25, 19p13, 19q13, 20q13, 21p11, 22q13, and Xq26-q28 were significantly bearing higher number of MIRs. The 14q32 and 19q13 with 4.11 and 3.59 MIRs per mega-base pair, respectively, were the most MIR-richest human chromosomal bands. The number of MIRs on chromosomal bands significantly decreased as a function of distance from telomere (r = − 0.949, df = 5, P = 0.001). Conclusions Our current data suggest that MIRs are not randomly distributed on human genomes.

2017 ◽  
Vol 63 (6) ◽  
pp. 481-498
Author(s):  
O.I. Kit ◽  
D.I. Vodolazhsky ◽  
E.E. Rostorguev ◽  
D.H. Porksheyan ◽  
S.B. Panina

Gliomas are invasive brain tumors with high rates of recurrence and mortality. Glioblastoma multiforme (GBM) is the most deadly form of glioma with nearly 100% rate of recurrence and unfavorable prognosis in patients. Micro-RNAs (miR) are the class of wide-spread short non-coding RNAs that inhibit translation via binding to the mRNA of target genes. The aim of the present review is to analyze recent studies and experimental results concerning aberrant expression profiles of miR, which target components of the signaling pathways Hedgehog, Notch, Wnt, EGFR, TGFb, HIF1a in glioma/glioblastoma. Particularly, the interactions of miR with targets of 2-hydroxyglutarate (the product of mutant isocytrate dehydrogenase, R132H IDH1, which is specific for the glioma pathogenesis) have been considered in the present review. Detecting specific miRNAs in tissue and serum may serve as a diagnostic and prognostic tool for glioma, as well as for predicting treatment response of an individual patient, and potentially serving as a mechanism for creating personalized treatment strategies


Stroke ◽  
2017 ◽  
Vol 48 (suppl_1) ◽  
Author(s):  
Kumar Vaibhav ◽  
Shannon Williams ◽  
Sumbul Fatima ◽  
Babak Baban ◽  
Krishnan M Dhandapani ◽  
...  

Background: Micro RNAs (miRNAs) could target multiple mRNAs, repressing the protein translation. We report acute changes in humoral miRNAome in a murine thromboembolic stroke model (eMCAo), and demonstrate the benefits of miRNA therapy in improving cerebral blood flow (CBF). Methods: Non-biased micro RNA (miRNA) array and bioinformatics analysis was performed in plasma collected at 4h post-eMCAo from male mice (C57/B6, 16-weeks). Individual PCR for miRNAs was also performed in brain tissues at 24h post-eMCAo. Moreover, frozen human plasma samples collected at ~4.5h post-stroke were also used for miRNA analysis. Finally, the miRNA mimic that was predicted to target genes of our interest was also tested in vivo and in vitro . Results: Principal component analysis (PCA) of the miRNA-array showed ~68% variance in the humoral miRNAome 4h after eMCAo in mice, and a significant change in Stroke vs. Sham groups (Cut off value >2 fold; p<0.05). Of interest, the hairpin precursor of miR-449b was downregulated (~2.35 fold, p<0.05) at 4h post-eMCAo, while the mature miR-449b was also significantly reduced at 24h post-eMCAo. Mature miR-449b was significantly reduced in human stroke plasma, too. In human brain endothelial cells, miR-449b mimic downregulated gene expressions of both plasminogen activator inhibitor (PAI-1) and alpha 2- antiplasmin (α-AP) only in hypoxia but not during normoxia. Therefore, we finally tested the cholesterol-conjugated miR-449b mimic in the murine eMCAo model. Pre-treatment with miR-449b mimic (8 mg/kg bwt) increased the absolute CBF and reduced edema (as determined by MRI), and also improved the neurological outcomes and reduced % infarct volume (p<0.05). Results: The miR-449b mimic could be a possible therapy to suppress aberrant gene expressions of PAI-1 and α-AP, which will allow more spontaneous reperfusion and benefits from low dose tPA.


2021 ◽  
Author(s):  
Peigen Chen ◽  
Yingchun Guo ◽  
Tingting Li ◽  
Lei Jia ◽  
Yanfang Wang ◽  
...  

Abstract BackgroundRecurrent implantation failure (RIF) is an obstacle in the process of assisted reproductive technology (ART). At present, there was limited research on its pathogenesis, diagnosis and treatment methods.ResultsIn this study, a series of analytical tools were used to analyze differences in miRNAs, mRNAs and lncRNAs in the endometrium of patients in the RIF group and the control group. At the same time, multiple databases are used to predict the target genes of non-coding RNAs. Then the competing endogenous RNA (ceRNA) network was built to describe the relationship between gene regulation in the endometrium of the RIF.ConcludesBased on the results of the logistic regression of co-expression miRNAs between serum and endometrial samples, we built a predictive model based on circulating miRNAs.


2020 ◽  
Vol 38 (15_suppl) ◽  
pp. e13516-e13516
Author(s):  
Inna A. Novikova ◽  
Natalya N. Timoshkina ◽  
Oleg Ivanovich Kit ◽  
Sergey I. Poluektov ◽  
Andrey V. Dashkov ◽  
...  

e13516 Background: The colorectal cancer (CRC) incidence is steadily increasing. Moreover, the problem of its early diagnosis remains unresolved due to the low specificity of known tumor markers, and the problem of creating new therapeutic approaches is due to the lack of a complete understanding of the mechanisms of regulation of gene expression in this oncopathology. The study of micro-RNAs (short non-coding RNAs that regulate gene expression) can be the solution to both problems. The aim of the study was to analyze micro-RNA differential expression in the tumor and non-tumor tissues of CRC patients. Methods: 5 patients with CRC (colon adenocarcinoma, G2) were selected for the multiple parallel micro-RNA sequencing. The mirVana miRNA Isolation Kit protocol was used to isolate small RNA fractions. The miRNA library was prepared using the TruSeq Small RNASample Preparation Kit. Sequencing of the nucleotide sequences of cDNA libraries was performed using a MiSeq (Illumina, USA). The copy numbers of micro-RNA were determined by comparing the nucleotide sequence of the sequenced molecules in each sample with the known nucleotide sequences of micro-RNA presented in the databases. When analyzing the differential expression of micro-RNA, the DESeq2 method implemented in R medium was used. Results: Six differentially expressed micro-RNAs were detected (p < 0.05): 2 that decrease expression (hsa-miR-143-3p,hsa-miR-26a-5p) and 4 increase expression in the tumor relative to non-tumor (hsa-miR-25-3p, hsa-miR-92a-3p, hsa-miR-21-5p, hsa-let-7i-5p). The highest level of expression in both tumor and non-tumor tissue was observed for hsa-miR-143-3p, the lowest one for hsa-let-7i-5p. Moreover, the largest difference in micro-RNA expression in tumor tissue relative to non-tumor was shown for hsa-miR-92a-3p (4.5 times, p = 0.02), the smallest for hsa-miR-143-3p (2.4 times, p = 0.04). For miRNAs that differentially changed their expression, a search was made for target genes using the miRWalk 3.0 database. 14573 target genes were found, of which 3346 were for hypo-expressed micro-RNAs and 11228 for hyper-expressed micro-RNAs. Conclusions: Sequencing revealed 6 differentially expressed micro-RNAs (hsa-miR-143-3p, hsa-miR-26a-5p, hsa-miR-25-3p, hsa-miR-92a-3p, hsa-miR-21-5p, hsa-let-7i-5p) in the tumor tissue is relatively non-tumor tissues of the colon. The data obtained expand the understanding of the mechanisms of gene regulation in the context of this oncopathology and may possibly become the basis for highly specific tumor markers panel.


Author(s):  
Benoit Forget ◽  
Elena Martin Garcia ◽  
Arthur Godino ◽  
Laura Domingo Rodriguez ◽  
Vincent Kappes ◽  
...  

AbstractThe persistent and experience-dependent nature of drug addiction may result in part from epigenetic alterations, including non-coding micro-RNAs (miRNAs), which are both critical for neuronal function and modulated by cocaine in the striatum. Two major striatal cell populations, the striato-nigral and striato-pallidal projection neurons, express, respectively, the D1 (D1-SPNs) and D2 (D2-SPNs) dopamine receptor, and display distinct but complementary functions in drug-evoked responses. However, a cell-type-specific role for miRNAs action has yet to be clarified. Here, we evaluated the expression of a subset of miRNAs proposed to modulate cocaine effects in the nucleus accumbens (NAc) and dorsal striatum (DS) upon sustained cocaine exposure in mice and showed that these selected miRNAs were preferentially upregulated in the NAc. We focused on miR-1 considering the important role of some of its predicted mRNA targets, Fosb and Npas4, in the effects of cocaine. We validated these targets in vitro and in vivo. We explored the potential of miR-1 to regulate cocaine-induced behavior by overexpressing it in specific striatal cell populations. In DS D1-SPNs miR-1 overexpression downregulated Fosb and Npas4 and reduced cocaine-induced CPP reinstatement, but increased cue-induced cocaine seeking. In DS D2-SPNs miR-1 overexpression reduced the motivation to self-administer cocaine. Our results indicate a role of miR1 and its target genes, Fosb and Npas4, in these behaviors and highlight a precise cell-type- and region-specific modulatory role of miR-1, illustrating the importance of cell-specific investigations.


Author(s):  
John C. Lucchesi

Most of the genome is transcribed into non-coding transcripts that far exceed in number the transcripts of protein-coding genes. These RNAs are subdivided into different classes. Long non-coding RNAs (lncRNAs) are at least 200 nucleotides in length and are transcribed from promoter, coding, intergenic or enhancer regions (eRNAs). These RNAs repress or enhance the transcription of target genes by facilitating the interaction between promoters and enhancers or by interacting with transcription factors and targeting histone-modifying enzymes. Short non-coding RNAs include a diverse group of functional types: miRNAs (micro RNAs) and siRNAs (small interfering RNAs) are negative regulators of gene expression; piRNAs (Piwi-interacting RNAs) suppress the action of transposable elements in the germline; snRNAs (small nuclear RNAs) are involved in mRNA splicing and rRNA maturation; tRNA-derived non-coding RNAs are involved in the cellular reaction to stress and in the repression of gene function. Additional short RNAs are rasiRNAs (repeat-associated small interfering RNAs) that appear to be involved in centromeric heterochromatin formation.


2012 ◽  
Vol 153 (52) ◽  
pp. 2051-2059 ◽  
Author(s):  
Zsuzsanna Gaál ◽  
Éva Oláh

MicroRNAs are a class of small non-coding RNAs regulating gene expression at posttranscriptional level. Their target genes include numerous regulators of cell cycle, cell proliferation as well as apoptosis. Therefore, they are implicated in the initiation and progression of cancer, tissue invasion and metastasis formation as well. MicroRNA profiles supply much information about both the origin and the differentiation state of tumours. MicroRNAs also have a key role during haemopoiesis. An altered expression level of those have often been observed in different types of leukemia. There are successful attempts to apply microRNAs in the diagnosis and prognosis of acute lymphoblastic leukemia and acute myeloid leukemia. Measurement of the expression levels may help to predict the success of treatment with different kinds of chemotherapeutic drugs. MicroRNAs are also regarded as promising therapeutic targets, and can contribute to a more personalized therapeutic approach in haemato-oncologic patients. Orv. Hetil., 2012, 153, 2051–2059.


2016 ◽  
Vol 3 (1) ◽  
Author(s):  
YASIN JESHIMA KHAN ◽  
HUSNARA Tyagi ◽  
Anil kumar Singh ◽  
Santosh kumar. Magadum

Plants respond through a cascade of reactions resulting in varied cellular environment leading to alterations in the patterns of protein expression resulting in phonotypic changes. Single cell genomics and global proteomics came out to be powerful tools and efficient techniques in studying stress tolerant plants. Non-coding RNAs are a distinct class of regulatory RNAs in plants and animals that control a variety of biological processes. Small ncRNAs play a vital role in post transcriptional gene regulation by either translational repression or by inducing mRNA cleavage. The major classes of small RNAs include microRNAs (miRNAs) and small interfering RNAs (siRNAs), which differ in their biogenesis. miRNAs control the expression of cognate target genes by binding to complementary sequences, resulting in cleavage or translational inhibition of the target RNAs. siRNAs too have a similar structure, function, and biogenesis like miRNAs but are derived from long double-stranded RNAs and can often direct DNA methylation at target sequences.In this review, we focus on the involvement of ncRNAs in comabting abiotic stresses of soybean. This review emphasis on previously known miRNAs as they play important role in several abiotic stresses like drought, salinity, chilling and heat stress by their diverse roles in mediating biological processes like gene expression, chromatin formation, defense of genome against invading viruses. This review attempts to elucidate the various kinds of non-coding RNAs explored, their discovery, biogenesis, functions, and response for different type of abiotic stresses and future aspects for crop improvement in the context of soybean, a representative grain legume.


Genes ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 1483
Author(s):  
Ivan Antonov ◽  
Yulia Medvedeva

Although thousands of mammalian long non-coding RNAs (lncRNAs) have been reported in the last decade, their functional annotation remains limited. A wet-lab approach to detect functions of a novel lncRNA usually includes its knockdown followed by RNA sequencing and identification of the deferentially expressed genes. However, identification of the molecular mechanism(s) used by the lncRNA to regulate its targets frequently becomes a challenge. Previously, we developed the ASSA algorithm that detects statistically significant inter-molecular RNA-RNA interactions. Here we designed a workflow that uses ASSA predictions to estimate the ability of an lncRNA to function via direct base pairing with the target transcripts (co- or post-transcriptionally). The workflow was applied to 300+ lncRNA knockdown experiments from the FANTOM6 pilot project producing statistically significant predictions for 71 unique lncRNAs (104 knockdowns). Surprisingly, the majority of these lncRNAs were likely to function co-transcriptionally, i.e., hybridize with the nascent transcripts of the target genes. Moreover, a number of the obtained predictions were supported by independent iMARGI experimental data on co-localization of lncRNA and chromatin. We detected an evolutionarily conserved lncRNA CHASERR (AC013394.2 or LINC01578) that could regulate target genes co-transcriptionally via interaction with a nascent transcript by directing CHD2 helicase. The obtained results suggested that this nuclear lncRNA may be able to activate expression of the target genes in trans by base-pairing with the nascent transcripts and directing the CHD2 helicase to the regulated promoters leading to open the chromatin and active transcription. Our study highlights the possible importance of base-pairing between nuclear lncRNAs and nascent transcripts for the regulation of gene expression.


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