• Journal of Life Science
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• v.27 no.12
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• pp.1494-1499
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• 2017

Oral infection due to Candida albicans is a widely recognized and frequent cause of superficial infections of the oral mucosa (oral candidiasis). Although oral candidiasis is not a life-threatening fungemia, it can cause severe problems in individuals under certain conditions. MicroRNAs (miRNAs) are noncoding, small RNA molecules, which regulate the expression of other genes by inhibiting the translation of target mRNAs. The present study was designed to identify miRNAs in C. albicans and determine their possible roles in this organism. miRNA-sized small RNAs (msRNAs) were cloned in C. albicans by deep sequencing, and their secondary structures were analyzed. All the cloned msRNAs satisfied conditions required to qualify them as miRNAs. Bioinformatics analysis revealed that two of the most highly expressed C. albicans msRNAs, Ca-363 and Ca-2019, were located in the 3' untranslated region of the corticosteroid-binding protein 1 (CBP1) gene in a reverse orientation. miRNA mimics were transformed into C. albicans to investigate their RNA-inhibitory functions. RNA oligonucleotide-transformed C. albicans was then observed by fluorescent microscopy. Quantitative PCR analysis showed that these msRNAs did not inhibit CBP1 gene expression 4 hr and 8 hr after ectopic miRNA transformation. These results suggest that msRNAs in C. albicans possess an miRNA-triggered RNA interference gene-silencing function, which is distinct from that exhibited by other eukaryotic systems.

• Journal of Life Science
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• v.26 no.9
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• pp.1097-1104
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• 2016

With the development of next generation sequencing (NGS), large numbers of transcriptional molecules have been discovered. Most transcripts are non -coding RNAs (ncRNAs). Among them, long non-coding RNAs (lncRNAs) with more than 200 nucleotides represent functional RNA molecule that will not be translated into protein. In plants, lncRNAs are transcribed by RNA polymerase II (Pol II) or Pol III, Pol VI and Pol V. After transcription of these lncRNAs, more RNA processing mechanisms such as splicing and polyadenylation occurs. The expression of plant lncRNAs is very low and is tissue specific. However, these lncRNAs are strongly induced by specific external stimuli. Because different external stimuli including environmental stresses induce a large number of plant lncRNAs, these lncRNAs have been gradually considered as new regulatory factors of various biological and development processes such as epigenetic repression, chromatin modification, target mimicry, photomorphogenesis, protein relocalization, environmental stress response, pathogen infection in plants. Moreover, some lncRNAs act as precursor of short RNAs. Although a large number of lncRNAs have been predicted and identified in plants, our current understanding of the biological function of these lncRNAs is still limited and their detailed regulatory mechanisms should be elucidated continuously. Here, we reviewed the biogenesis and regulation mechanisms of lncRNAs and summarized the molecular functions unraveled in plants.

• Applied Biological Chemistry
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• v.38 no.1
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• pp.55-62
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• 1995

To understand the molecular structure of Korean garlic viruses, cDNA cloning of virus genomic RNA was attempted. Virus particles were isolated from virus-infected garlic leaves and a cDNA library was constructed from garlic virus RNA. One of these clones, S81, selected by random sequencing has been identified as a member of potexvirus group other than potyvirus and carlavirus. The clone is 873 bp long contains most of the coat protein (CP) coding region and 3'-noncoding region including poly(A) tail. A putative polyadenylation signal sequence (AAUAAA) and the hexanucleotide motif (ACUUAA), a replicational cis-acting element conserved in the 3'-noncoding region of potexvirus RNAs are noticed. The clone S81 shows about 30-40% identity in both nucleotide and amino acid sequences with CPs of potexviruses. The genome size of the virus was analysed to be 7.46 knt by Northern blot analysis, which was longer than those of other potexviruses. The open reading frame encoding CP was expressed as a fusion protein (S81CP) in Escherichia coli and the recombinant protein was purified by immobilized metal binding affinity chromatography. Polyclonal antibody was raised against S81CP in rabbit to examine the occurrence of garlic potexvirus in Korean garlic plants by immunoblot analysis. Two virus protein bands of Mr 27,000 and 29,000 from garlic leaf extract of various cultivars reacted with the antibody. It was shown that Mr 27,000 band might not be a degradation product of Mr 29,000 band, suggesting that two types of potexvirus different in size of coat protein could exist in Korean garlic plants.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.2
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• pp.591-598
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• 2012

Aim and background: MicroRNAs (miRNAs) are a class of naturally occurring small noncoding RNAs that regulate gene expression, cell growth, differentiation and apoptosis by targeting mRNAs for translational repression or cleavage. The present study was conducted to study miRNAs in Egyptian breast cancer (BC) and their relation to metastasis, tumor invasion and apoptosis in addition to their association with the ER and PR statuses. Methods: Real Time RT-PCR was performed to identify the miRNA expression level of eight miRNAs and eight metastatic-related genes in 40 breast cancer samples and their adjacent non-neoplastic tissues. The expression levels of each miRNA relative to U6 RNA were determined using the $^{2-{\Delta}}CT$ method. Also, miRNA expression profiles of the BC and their corresponding ANT were evaluated. Results: The BC patients showed an up-regulation in miRNAs (mir-155, mir-10, mir-21 and mir-373) with an upregulation in MMP2, MMp9 and VEGF genes. We found down regulation in mir-17p, mir-126, mir-335, mir-30b and also TIMP3, TMP1 and PDCD4 genes in the cancer tissue compared to the adjacent non-neoplastic tissues. Mir -10b, mir -21, mir-155 and mir373 and the metastatic genes MMP2, MMP9 and VEGF were significantly associated with an increase in tumor size (P < 0.05). No significant difference was observed between any of the studied miRNAs regarding lymph node metastasis. Mir-21 was significantly over-expressed in ER-/PR-cases. Conclusion: Specific miRNAs (mir-10, mir-21, mir-155, mir-373, mir-30b, mir-126, mir-17p, mir-335) are associated with tumor metastasis and other clinical characteristics for BC, facilitating identification of individuals who are at risk.

• Animal cells and systems
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• v.3 no.4
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• pp.393-397
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• 1999

Length variations in human mitochondrial DNA (mtDNA) offer useful markers in the study of female aspects of human population history. One such length variation is a 9-bp deletion in the small noncoding segment located between the COII and Iysine tRNA genes (COII/tRNA/$^{Lys}$ intergenic region) which usually contain two tandemly arranged copies of a 9-bp sequence (ccccctcta) in human mtDNA. The mtDNA 9-bp deletion and polymorphic variants of expanded 9-bp repeat motif in the intergenic COII/tRNA$^{Lys}$ region have been found at varying frequencies among different human ethnic groups. We have examined the length variation of the mtDNA COII/tRNA$^{Lys}$ intergenic region from a total of 813 individuals in east Asian populations. The occurrence of the 9-bp deletion was found to be relatively homogeneous in northeast Asian populations (Chinese, 14.2%; Japanese, 14.3%: Koreans, 15.5%), with the exception of Mongolians (5.1%). In contrast, Indonesians (25.0%) and Vietnamese (23.2%) of the southeast Asian populations appeared to have relatively high frequencies of the 9-bp deletion. We identified the existence of a new expanded 9-bp repeat motif which likely resulted from a slipped mispairing insertion of six more cytosines in the intergenic COII$^{Lys}$ region. It was present at low frequencies in the Korean (2/349) and Japanese populations (2/147). Based on the results of this study, the Korean population may reflect a close genetic affinity with the Japanese and Chinese populations than the others surveyed east Asian populations.

• BMB Reports
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• v.49 no.6
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• pp.311-318
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• 2016

Innate immune responses are primary, relatively limited, and specific responses to numerous pathogens and toxic molecules. Protein expression involved in these innate responses must be tightly regulated at both transcriptional level and post-transcriptional level to avoid the development of excessive inflammation that can be potentially harmful to the host. MicroRNAs are small noncoding RNAs (∼22 nucleotides [nts]) that participate in the regulation of numerous physiological responses by targeting specific messenger RNAs to suppress their translation. Recent work has shown that several negative regulators of transcription including microRNAs play important roles in inhibiting the exacerbation of inflammatory responses and in the maintenance of immunological homeostasis. This emerging research area will provide new insights on how microRNAs regulate innate immune signaling. It might show that dysregulation of microRNA synthesis is associated with the pathogenesis of inflammatory and infectious diseases. In this review, we focused on miR-146 and miR-125 and described the roles these miRNAs in modulating innate immune signaling. These microRNAs can control inflammatory responses and the outcomes of pathogenic infections.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.23
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• pp.10181-10185
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• 2015

Background: MicroRNAs, small noncoding RNA molecules, can regulate mammalian cell growth, apoptosis and differentiation by controlling the expression of target genes. The aim of this study was to investigate the function of miR-323-5p in the glioma cell line, U251. Materials and Methods: After over-expression of miR-323-5p using miR-323-5p mimics, cell growth, apoptosis and migration were tested by MTT, flow cytometry and cell wound healing assay, respectively. We also assessed the influence of miR-323-5p on the mRNA expression of IGF-1R by quantitative real-time reverse transcriptase PCR (qRT-PCR), and on the protein levels by Western blot analysi. In addition, dual-luciferase reporter assays were performed to determine the target site of miR-323-5p to IGF-1R 3'UTR. Results: Our findings showed that over-expression of miR-323-5p could promote apoptosis of U251 and inhibit the proliferation and migration of the glioma cells. Conclusions: This study demonstrated that increased expression of miR-323-5p might be related to glioma progression, which indicates a potential role of miR-323-5p for clinical therapy.

• The Plant Pathology Journal
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• v.30 no.1
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• pp.68-74
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• 2014

Chrysanthemum stunt viroid (CSVd), a noncoding infectious RNA molecule, causes seriously economic losses of chrysanthemum for 3 or 4 years after its first infection. Monomeric cDNA clones of CSVd isolate SK1 (CSVd-SK1) were constructed in the plasmids pGEM-T easy vector and pUC19 vector. Linear positive-sense transcripts synthesized in vitro from the full-length monomeric cDNA clones of CSVd-SK1 could infect systemically tomato seedlings and chrysanthemum plants, suggesting that the linear CSVd RNA transcribed from the cDNA clones could be replicated as efficiently as circular CSVd in host species. However, direct inoculation of plasmid cDNA clones containing full-length monomeric cDNA of CSVd-SK1 failed to infect tomato and chrysanthemum and linear negative-sense transcripts from the plasmid DNAs were not infectious in the two plant species. The cDNA sequences of progeny viroid in systemically infected tomato and chrysanthemum showed a few substitutions at a specific nucleotide position, but there were no deletions and insertions in the sequences of the CSVd progeny from tomato and chrysanthemum plants.

• BMB Reports
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• v.42 no.8
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• pp.493-499
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• 2009

MicroRNAs (miRs) are a family of small noncoding RNAs that regulate gene expression by targeting mRNAs in a sequence specific manner, inducing translational repression or mRNA degradation. In this paper we have first analyzed by microarray the miR-profile in erythroid precursor cells from one normal and two thalassemic patients expressing different levels of fetal hemoglobin (one of them displaying HPFH phenotype). The microarray data were confirmed by RT-PCR analysis, and allowed us to identify miR-210 as an highly expressed miR in the erythroid precursor cells from the HPFH patient. When RT-PCR was performed on mithramycin-induced K562 cells and erythroid precursor cells, miR-210 was found to be induced in time-dependent and dose-dependent fashion, together with increased expression of the fetal $\gamma$-globin genes. Altogether, the data suggest that miR-210 might be involved in increased expression of $\gamma$-globin genes in differentiating erythroid cells.

• Experimental and Molecular Medicine
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• v.50 no.12
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• pp.7.1-7.14
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• 2018

Dysregulation of long noncoding RNA (lncRNA) expression is linked to the development of various diseases. Recently, an emerging body of evidence has indicated that lncRNAs play important roles in the pathogenesis of inflammatory bowel diseases (IBDs), including Crohn's disease (CD) and ulcerative Colitis (UC). In IBD, lncRNAs have been shown to be involved in diverse processes, including the regulation of intestinal epithelial cell apoptosis, association with lipid metabolism, and cell-cell interactions, thereby enhancing inflammation and the functional regulation of regulatory T cells. In this review, we aim to summarize the current knowledge regarding the role of lncRNAs in IBD and highlight potential avenues for future investigation. We also collate potentially immune-relevant, IBD-associated lncRNAs identified through a built-by association analysis with respect to their neighboring protein-coding genes within IBD-susceptible loci. We further underscore their importance by highlighting their enrichment for various aspects of immune system regulation, including antigen processing/presentation, immune cell proliferation and differentiation, and chronic inflammatory responses. Finally, we summarize the potential of lncRNAs as diagnostic biomarkers in IBD.