Untranslated Region Of mRNA Research Articles

An Optimized Single Nucleotide Polymorphism-Based Detection Method Suggests That Allelic Variants in the 3' Untranslated Region of RRAS2 Correlate with Treatment Response in Chronic Lymphocytic Leukemia Patients.

Unlike classical RAS genes, oncogenic mutations on RRAS2 are seldomly found in human cancer. By contrast, RRAS2 is frequently found overexpressed in a number of human tumors, including B and T cell lymphomas, breast, gastric, head and neck cancers. In this regard, we have recently shown that overexpression of wild-type RRAS2 drives the formation of both chronic lymphocytic leukemia (CLL) and breast cancer in mice. In support for the relevance of overexpression of wild type RRAS2 in human cancer, we have found that RRAS2 expression is influenced by the presence of a specific single nucleotide polymorphism (SNP) located in the 3'-untranslated region (UTR) of the RRAS2 mRNA. Perhaps more importantly, the presence of the alternate C, rather than the G allele, at the RRAS2 SNP designated as rs8570 is also associated with worse patient prognosis in CLL. This indicates that the detection of this SNP allelic variants can be informative to predict RRAS2 expression levels and disease long-term evolution in patients. Here, we describe a polymerase chain reaction (PCR)-based method that facilitates the rapid and easy determination of G and C allelic variants of the SNP. Using this approach, we confirm that the C allelic variant is associated with higher expression levels of RRAS2 transcripts and poor patient prognosis. However, we have also found that expression of the C allelic variants correlates with better response to ibrutinib, a Bruton kinase inhibitor commonly used in CLL treatments. This suggests that this method for detecting the RRAS2 rs8570 SNP might be a useful as a tool to predict both patient prognosis and response to targeted therapy in CLL.

Exploring structural determinants and the role of nucleolin in formation of the long-range interactions between untranslated regions of p53 mRNA.

p53 protein is a key regulator of cellular homeostasis by coordinating the framework of antiproliferative pathways as a response to various stress factors. Although the main mechanism of stress-dependent induction of p53 protein relies on post-translational modifications influencing its stability and activity, a growing amount of evidence suggests that complex regulation of p53 expression occurs also at the mRNA level. This study explores structural determinants of long-range RNA-RNA interactions in p53 mRNA, crucial for stress-dependent regulation of p53 protein translation. We demonstrate that the 8-nt bulge motif plays a key structural role in base-pairing of complementary sequences from the 5' and 3' untranslated regions of p53 mRNA. We also show that one of the p53 translation regulators, nucleolin, displays an RNA chaperone activity and facilitates the association of sequences involved in the formation of long-range interactions in p53 mRNA. Nucleolin promotes base-pairing of complementary sequences through the bulge motif, because mutations of this region reduce or inhibit pairing while compensatory mutations restore this interaction. Mutational analysis of nucleolin reveals that all four RNA recognition motifs are indispensable for optimal RNA chaperone activity of nucleolin. These observations help to decipher the unique mechanism of p53 protein translation regulation pointing to bulge motif and nucleolin as the critical factors during intramolecular RNA-RNA recognition in p53 mRNA.

DBP7 and YRF1-6 Are Involved in Cell Sensitivity to LiCl by Regulating the Translation of PGM2 mRNA.

Lithium chloride (LiCl) has been widely researched and utilized as a therapeutic option for bipolar disorder (BD). Several pathways, including cell signaling and signal transduction pathways in mammalian cells, are shown to be regulated by LiCl. LiCl can negatively control the expression and activity of PGM2, a phosphoglucomutase that influences sugar metabolism in yeast. In the presence of galactose, when yeast cells are challenged by LiCl, the phosphoglucomutase activity of PGM2p is decreased, causing an increase in the concentration of toxic galactose metabolism intermediates that result in cell sensitivity. Here, we report that the null yeast mutant strains DBP7∆ and YRF1-6∆ exhibit increased LiCl sensitivity on galactose-containing media. Additionally, we demonstrate that DBP7 and YRF1-6 modulate the translational level of PGM2 mRNA, and the observed alteration in translation seems to be associated with the 5'-untranslated region (UTR) of PGM2 mRNA. Furthermore, we observe that DBP7 and YRF1-6 influence, to varying degrees, the translation of other mRNAs that carry different 5'-UTR secondary structures.

Untranslated regions of brain-derived neurotrophic factor mRNA control its translatability and subcellular localization

Brain-derived neurotrophic factor (BDNF) promotes neuronal survival and growth during development. In the adult nervous system, BDNF is important for synaptic function in several biological processes such as memory formation and food intake. In addition, BDNF has been implicated in development and maintenance of the cardiovascular system. The Bdnf gene comprises several alternative untranslated 5' exons and two variants of 3' UTRs. The effects of these entire alternative UTRs on translatability have not been established. Using reporter and translating ribosome affinity purification analyses, we show that prevalent Bdnf 5' UTRs, but not 3' UTRs, exert a repressive effect on translation. However, contrary to previous reports, we do not detect a significant effect of neuronal activity on BDNF translation. Invivo analysis via knock-in conditional replacement of Bdnf 3' UTR by bovine growth hormone 3' UTR reveals that Bdnf 3' UTR is required for efficient Bdnf mRNA and BDNF protein production in the brain, but acts in an inhibitory manner in lung and heart. Finally, we show that Bdnf mRNA is enriched in rat brain synaptoneurosomes, with higher enrichment detected for exon I-containing transcripts. In conclusion, these results uncover two novel aspects in understanding the function of Bdnf UTRs. First, the long Bdnf 3' UTR does not repress BDNF expression in the brain. Second, exon I-derived 5' UTR has a distinct role in subcellular targeting of Bdnf mRNA.

Role of let-7 family in the invasion and metastasis of osteosarcoma.

Role of let-7 family in the invasion and metastasis of osteosarcoma.

MiR-20a-5p alleviates kidney ischemia/reperfusion injury by targeting ACSL4-dependent ferroptosis

Ischemia/reperfusion injury (IRI) is prone to occur after kidney transplantation, leading to delayed graft function (DGF). MicroRNAs play a crucial role in the pathogenesis of ischemia/reperfusion–induced acute kidney injury, and miR-20a-5p was found to be the most significantly upregulated gene in a DGF patient cohort. However, the roles of microRNAs in transplanted kidneys remain largely unknown. In this study, we found that miR-20a-5p was upregulated in the kidneys of acute kidney injury mice and in patients with DGF. We identified early growth response-1 as a critical upstream target and verified the binding of early growth response-1 to a predicted sequence in the promoter region of the miR-20a-5p gene. Functionally, the miR-20a-5p mimic attenuated IRI and postischemic renal fibrosis, whereas the miR-20a-5p inhibitor delivery aggravated IRI and fibrosis. Importantly, delivery of the miR-20a-5p mimic or inhibitor in the donor kidneys attenuated or aggravated renal loss and structural damage in cold storage transplantation injury. Furthermore, our study identified miR-20a-5p as a negative regulator of acyl-CoA synthetase long-chain family member 4 (ACSL4) by targeting the 3′ untranslated region of ACSL4 mRNA, thereby inhibiting ACSL4-dependent ferroptosis. Our results suggest a potential therapeutic application of miR-20a-5p in kidney transplantation through the inhibition of ACSL4-dependent ferroptosis.

Erianin Induces Ferroptosis of Renal Cancer Stem Cells via Promoting ALOX12/P53 mRNA N6-methyladenosine Modification.

Renal cell carcinoma (RCC) is the most common type of primary renal parenchymal malignancy in adults, with a high degree of malignancy and poor prognosis. Human renal cancer stem cells (HuRCSCs) are reported to be the main cause of drug resistance, metastasis, recurrence, and poor prognosis. Erianin is a low molecular-weight bibenzyl natural product extracted from Dendrobium chrysotoxum, which inhibits the in vitro and in vivo activity of a variety of cancer cells. However, the molecular mechanisms of Erianin's therapeutic effect on HuRCSCs are unknown. Here, we isolated CD44+/CD105+ HuRCSCs from patients with renal cell carcinoma. The experiments confirmed that Erianin significantly inhibited the proliferation, invasion, angiogenesis, and tumorigenesis of HuRCSCs, and induced oxidative stress injury and Fe2+ accumulation. qRT-PCR and western blotting showed that Erianin significantly reduced the expression levels of cellular Ferroptosis protective factors, and upregulated the expression of METTL3 and downregulated that of FTO. Dot blotting results indicated that Erianin significantly upregulated the mRNA N6-methyladenosine (m6A) modification of HuRCSCs. The results of RNA immunoprecipitation-PCR also indicated that Erianin significantly enhanced the m6A modification level of the 3' untranslated region of ALOX12 and P53 mRNA in HuRCSCs, resulting in increased stability, prolonged half-life, and improved translation activity. In addition, clinical data analysis showed that the expression of FTO correlated negatively with adverse events in patient with renal cell carcinoma. Thus, this study suggested that Erianin can induce Ferroptosis in renal cancer stem cells by promoting N6-methyladenosine modification of ALOX12/P53 mRNA, ultimately achieving a therapeutic effect on renal cancer.

Analysis of MicroRNAs in Ferroptosis.

MicroRNAs (miRNAs) are a class of small non-coding RNA molecules that are involved in a wide range of biological processes, including development, differentiation, and disease. They function by binding to the 3' untranslated region (UTR) of target mRNAs, leading to mRNA degradation or translational repression. miRNAs are involved in the regulation of many cellular processes, including cell proliferation, apoptosis, and metabolism. MiRNAs have been shown to modulate ferroptosis in several ways. Some miRNAs have been shown to promote ferroptosis by increasing the expression of genes involved in lipid peroxidation. Other miRNAs have been shown to inhibit ferroptosis by decreasing the expression of genes involved in iron uptake. The role of miRNAs in ferroptosis is still being studied, but they play a significant role in this cell death pathway. miRNAs may be potential targets for therapeutic intervention in diseases associated with ferroptosis, such as cancer and neurodegenerative diseases. This chapter outlines several methods used to study the connection between miRNAs and ferroptosis through target discovery and validation.

MicroRNA-322 inhibition of calcification of arterial smooth muscle cells by regulation of galactosyltransferase 1-associating protein UBE2Q1 and Runx2

Background and purpose: Vascular smooth muscle cell (SMC) calcification represents a prominent phenotypic alteration in atherosclerosis. MicroRNA-322 (miR-322) is crucially involved in myogenic stem cell growth and differentiation. The galactosyltransferase 1-associated protein (GTAP) is a ubiquitin-conjugating enzyme E2Q1 (UBE2Q1) that serves as a critical mediator of post-translational regulation of certain cellular enzymes and transcription factors. Runt-related transcription factor 2 (Runx2) plays a critical role in arterial calcification. However, the interplay between miR-322, UBE2Q1, and Runx2 during cardiovascular calcification remain largely unknown. Therefore, the purpose of this study is to delineate the molecular mechanisms by which miR-322 regulates vascular calcification. Methods: Here we examined miR-322 expression in murine SMC, and determined whether miR-322 regulates SMC calcification via modulating expression of UBE2Q1 and calcifying proteins. Murine SMC cultures or aortic segments were exposed to inorganic phosphate (Pi) for induction of calcification. Expressions of calcification-related genes in SMC with lentivirus-mediated knockdown of UBE2Q1 were determined with Western blot analysis and quantitative real-time polymerase chain reaction (qRT-PCR). Luciferase reporter assay was performed to validate miR-322 target binding and SMC were transfected with anti-miR-322 oligonucleotides to inhibit miR-322 function. Results: Aortic rings derived from UBE2Q1−/− mice exhibited much higher calcium content compared to aortic rings from wildtype (WT) animals, following calcification induction. Knockdown of UBE2Q1 by lentiviral short hairpin RNA (shRNA) significantly enhanced the calcium deposition and expression of osteogenic gene Runx2 in SMC. Enhanced UBE2Q1 expression dramatically reduced calcification while promoting expression of contractile proteins SM22α and α-SMA. Treatment with anti-miR-322 diminished the luciferase activity in SMC transfected with the reporter gene driven by the 3′-untranslated region of UBE2Q1 mRNA. Anti-miR-322 treatment also inhibited calcification significantly. Conclusions: Our study identified miR-322 regulates vascular calcification by targeting UBE2Q1. The miR-322–dependent regulation of UBE2Q1 and calcification represents a novel regulatory mechanism that controls vascular SMC function during the pathogenesis of vascular calcification.

The Influence of the Nucleotide Composition of Genes and Gene Regulatory Elements on the Efficiency of Protein Expression in Escherichia coli

Recombinant proteins expressed in Escherichia coli are widely used in biochemical research and industrial processes. At the same time, achieving higher protein expression levels and correct protein folding still remains the key problem, since optimization of nutrient media, growth conditions, and methods for induction of protein synthesis do not always lead to the desired result. Often, low protein expression is determined by the sequences of the expressed genes and their regulatory regions. The genetic code is degenerated; 18 out of 20 amino acids are encoded by more than one codon. Choosing between synonymous codons in the coding sequence can significantly affect the level of protein expression and protein folding due to the influence of the gene nucleotide composition on the probability of formation of secondary mRNA structures that affect the ribosome binding at the translation initiation phase, as well as the ribosome movement along the mRNA during elongation, which, in turn, influences the mRNA degradation and the folding of the nascent protein. The nucleotide composition of the mRNA untranslated regions, in particular the promoter and Shine-Dalgarno sequences, also affects the efficiency of mRNA transcription, translation, and degradation. In this review, we describe the genetic principles that determine the efficiency of protein production in Escherichia coli.

Grad-seq analysis of Enterococcus faecalis and Enterococcus faecium provides a global view of RNA and protein complexes in these two opportunistic pathogens.

Enterococcus faecalis and Enterococcus faecium are major nosocomial pathogens. Despite their relevance to public health and their role in the development of bacterial antibiotic resistance, relatively little is known about gene regulation in these species. RNA-protein complexes serve crucial functions in all cellular processes associated with gene expression, including post-transcriptional control mediated by small regulatory RNAs (sRNAs). Here, we present a new resource for the study of enterococcal RNA biology, employing the Grad-seq technique to comprehensively predict complexes formed by RNA and proteins in E. faecalis V583 and E. faecium AUS0004. Analysis of the generated global RNA and protein sedimentation profiles led to the identification of RNA-protein complexes and putative novel sRNAs. Validating our data sets, we observe well-established cellular RNA-protein complexes such as the 6S RNA-RNA polymerase complex, suggesting that 6S RNA-mediated global control of transcription is conserved in enterococci. Focusing on the largely uncharacterized RNA-binding protein KhpB, we use the RIP-seq technique to predict that KhpB interacts with sRNAs, tRNAs, and untranslated regions of mRNAs, and might be involved in the processing of specific tRNAs. Collectively, these datasets provide departure points for in-depth studies of the cellular interactome of enterococci that should facilitate functional discovery in these and related Gram-positive species. Our data are available to the community through a user-friendly Grad-seq browser that allows interactive searches of the sedimentation profiles (https://resources.helmholtz-hiri.de/gradseqef/).

Long Non-Coding RNA GAS5 Promotes BAX Expression by Competing with microRNA-128-3p in Response to 5-Fluorouracil.

The acquisition of drug resistance is a major hurdle for effective cancer treatment. Although several efforts have been made to overcome drug resistance, the underlying mechanisms have not been fully elucidated. This study investigated the role of long non-coding RNA (lncRNA) growth arrest-specific 5 (GAS5) in drug resistance. GAS5 was found to be downregulated in colon cancer cell lines that are resistant to 5-fluorouracil (5-FU). Downregulation of GAS5 decreased the viability of HCT116 cells and the level of the pro-apoptotic BAX protein, while GAS5 overexpression promoted cell death in response to 5-FU. The interaction between GAS5 and BAX mRNA was investigated using MS2-tagged RNA affinity purification (MS2-trap) followed by RT-qPCR, and the results showed that GAS5 bound to the 3'-untranslated region of BAX mRNA and enhanced its expression by interfering with the inhibitory effect of microRNA-128-3p, a negative regulator of BAX. In addition, ectopic expression of GAS5 increased the sensitivity of resistant cells in response to anti-cancer drugs. These results suggest that GAS5 promoted cell death by interfering with miR-128-3p-mediated BAX downregulation. Therefore, GAS5 overexpression in chemo-resistant cancer cells may be a potential strategy to improve the anti-cancer efficacy of drugs.

MicroRNAs: Critical Players during Helminth Infections

microRNAs (miRNAs) are a group of small non-coding RNAs that regulate gene expression post-transcriptionally through their interaction with the 3' untranslated regions (3' UTR) of target mRNAs, affecting their stability and/or translation. Therefore, miRNAs regulate biological processes such as signal transduction, cell death, autophagy, metabolism, development, cellular proliferation, and differentiation. Dysregulated expression of microRNAs is associated with infectious diseases, where miRNAs modulate important aspects of the parasite-host interaction. Helminths are parasitic worms that cause various neglected tropical diseases affecting millions worldwide. These parasites have sophisticated mechanisms that give them a surprising immunomodulatory capacity favoring parasite persistence and establishment of infection. In this review, we analyze miRNAs in infections caused by helminths, emphasizing their role in immune regulation and its implication in diagnosis, prognosis, and the development of therapeutic strategies.

Emerging Role of MicroRNA-30c in Neurological Disorders.

MicroRNAs (miRNAs or miRs) are a class of small non-coding RNAs that negatively regulate the expression of target genes by interacting with 3' untranslated regions of target mRNAs to induce mRNA degradation and translational repression. The miR-30 family members are involved in the development of many tissues and organs and participate in the pathogenesis of human diseases. As a key member of the miR-30 family, miR-30c has been implicated in neurological disorders such as Alzheimer's disease, Parkinson's disease, multiple sclerosis, and stroke. Mechanistically, miR-30c may act as a multi-functional regulator of different pathogenic processes such as autophagy, apoptosis, endoplasmic reticulum stress, inflammation, oxidative stress, thrombosis, and neurovascular function, thereby contributing to different disease states. Here, we review and discuss the biogenesis, gene regulation, and the role and mechanisms of action of miR-30c in several neurological disorders and therapeutic potential in clinics.

Dysregulated thrombospondin 1 and miRNA-29a-3p in severe COVID-19.

Although nearly a fifth of symptomatic COVID-19 patients suffers from severe pulmonary inflammation, the mechanism of developing severe illness is not yet fully understood. To identify significantly altered genes in severe COVID-19, we generated messenger RNA and micro-RNA profiling data of peripheral blood mononuclear cells (PBMCs) from five COVID-19 patients (2 severe and 3 mild patients) and three healthy controls (HC). For further evaluation, two publicly available RNA-Seq datasets (GSE157103 and GSE152418) and one single-cell RNA-Seq dataset (GSE174072) were employed. Based on RNA-Seq datasets, thrombospondin 1 (THBS1) and interleukin-17 receptor A (IL17RA) were significantly upregulated in severe COVID-19 patients' blood. From single-cell RNA-sequencing data, IL17RA level is increased in monocytes and neutrophils, whereas THBS1 level is mainly increased in the platelets. Moreover, we identified three differentially expressed microRNAs in severe COVID-19 using micro-RNA sequencings. Intriguingly, hsa-miR-29a-3p significantly downregulated in severe COVID-19 was predicted to bind the 3'-untranslated regions of both IL17RA and THBS1 mRNAs. Further validation analysis of our cohort (8 HC, 7 severe and 8 mild patients) showed that THBS1, but not IL17RA, was significantly upregulated, whereas hsa-miR-29a-3p was downregulated, in PBMCs from severe patients. These findings strongly suggest that dysregulated expression of THBS1, IL17RA, and hsa-miR-29a-3p involves severe COVID-19.

Elusive Trans-Acting Factors Which Operate with Type I (Poliovirus-like) IRES Elements.

The phenomenon of internal initiation of translation was discovered in 1988 on poliovirus mRNA. The prototypic cis-acting element in the 5' untranslated region (5'UTR) of poliovirus mRNA, which is able to direct initiation at an internal start codon without the involvement of a cap structure, has been called an IRES (Internal Ribosome Entry Site or Segment). Despite its early discovery, poliovirus and other related IRES elements of type I are poorly characterized, and it is not yet clear which host proteins (a.k.a. IRES trans-acting factors, ITAFs) are required for their full activity in vivo. Here we discuss recent and old results devoted to type I IRESes and provide evidence that Poly(rC) binding protein 2 (PCBP2), Glycyl-tRNA synthetase (GARS), and Cold Shock Domain Containing E1 (CSDE1, also known as UNR) are major regulators of type I IRES activity.

Small RNAs Activate Salmonella Pathogenicity Island 1 by Modulating mRNA Stability through the hilD mRNA 3' Untranslated Region.

Salmonella enterica serovar Typhimurium is an enteric pathogen associated with foodborne disease. Salmonella invades the intestinal epithelium using a type three secretion system encoded on Salmonella pathogenicity island 1 (SPI-1). SPI-1 genes are tightly regulated by a complex feed-forward loop to ensure proper spatial and temporal expression. Most regulatory input is integrated at HilD, through control of hilD mRNA translation or HilD protein activity. The hilD mRNA possesses a 310-nucleotide 3' untranslated region (UTR) that influences HilD and SPI-1 expression, and this regulation is dependent on Hfq and RNase E, cofactors known to mediate small RNA (sRNA) activities. Thus, we hypothesized that the hilD mRNA 3' UTR is a target for sRNAs. Here, we show that two sRNAs, SdsR and Spot 42, regulate SPI-1 by targeting different regions of the hilD mRNA 3' UTR. Regulatory activities of these sRNAs depended on Hfq and RNase E, in agreement with previous roles found for both at the hilD 3' UTR. Salmonella mutants lacking SdsR and Spot 42 had decreased virulence in a mouse model of infection. Collectively, this work suggests that these sRNAs targeting the hilD mRNA 3' UTR increase hilD mRNA levels by interfering with RNase E-dependent mRNA degradation and that this regulatory effect is required for Salmonella invasiveness. Our work provides novel insights into mechanisms of sRNA regulation at bacterial mRNA 3' UTRs and adds to our knowledge of post-transcriptional regulation of the SPI-1 complex feed-forward loop. IMPORTANCE Salmonella enterica serovar Typhimurium is a prominent foodborne pathogen, infecting millions of people a year. To express virulence genes at the correct time and place in the host, Salmonella uses a complex regulatory network that senses environmental conditions. Known for their role in allowing quick responses to stress and virulence conditions, we investigated the role of small RNAs in facilitating precise expression of virulence genes. We found that the 3' untranslated region of the hilD mRNA, encoding a key virulence regulator, is a target for small RNAs and RNase E. The small RNAs stabilize hilD mRNA to allow proper expression of Salmonella virulence genes in the host.

RNA binding protein HuD mediates the crosstalk between β cells and islet endothelial cells by the regulation of Endostatin and Serpin E1 expression

RNA binding protein HuD plays essential roles in gene expression by regulating RNA metabolism, and its dysregulation is involved in the pathogenesis of several diseases, including tumors, neurodegenerative diseases, and diabetes. Here, we explored HuD-mediated differential expression of secretory proteins in mouse insulinoma βTC6 cells using a cytokine array. Endostatin and Serpin E1 that play anti-angiogenic roles were identified as differentially expressed proteins by HuD. HuD knockdown increased the expression of α chain of collagen XVIII (Col18a1), a precursor form of endostatin, and Serpin E1 by associating with the 3′-untranslated regions (UTRs) of Col18a1 and Serpin E1 mRNAs. Reporter analysis revealed that HuD knockdown increased the translation of EGFP reporters containing 3′UTRs of Col18a1 and Serpin E1 mRNAs, which suggests the role of HuD as a translational repressor. Co-cultures of βTC6 cells and pancreatic islet endothelial MS1 cells were used to assess the crosstalk between β cells and islet endothelial cells, and the results showed that HuD downregulation in βTC6 cells inhibited the growth and migration of MS1 cells. Ectopic expression of HuD decreased Col18a1 and Serpin E1 expression, while increasing the markers of islet vascular cells in the pancreas of db/db mice. Taken together, these results suggest that HuD has the potential to regulate the crosstalk between β cells and islet endothelial cells by regulating Endostatin and Serpin E1 expression, thereby contributing to the maintenance of homeostasis in the islet microenvironment.

MiR-193-5p negatively regulates PIK3CD to promote crop fibrocyte proliferation in pigeon (Columba livia)

The crop of pigeon has specific characteristics as producing crop milk in the lactating period. However, the exact mechanisms underlying the regulation of crop lactation remain unclear. miRNAs, the essential regulators of gene expression, are implicated in various physiological and biological activities. In this study, we discovered a new miRNA that regulated phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit delta (PIK3CD) and crop fibrocyte proliferation. Results of the luciferase reporter assay suggested that miR-193-5p suppressed PIK3CD expression by targeting a conserved binding site in the 3'-untranslated region (UTR) of PIK3CD mRNA. MiR-193-5p promoted crop fibrocyte proliferation and migration, whereas PIK3CD inhibited these effects. These findings suggested an important regulatory role of miR-193-5p in crop fibrocyte proliferation, suggesting that miR-193-5p and PIK3CD might be important regulators of crop milk production.

PiRNAs may regulate expression of candidate genes of esophageal adenocarcinoma.

Elucidation of ways to regulate the expression of candidate cancer genes will contribute to the development of methods for cancer diagnosis and therapy. The aim of the present study was to show the role of piRNAs as efficient regulators of mRNA translation of esophageal adenocarcinoma (EAC) candidate genes. We used bioinformatic methods to study the interaction characteristics of up to 200 thousand piRNAs with mRNAs of 38 candidate EAC genes. The piRNAs capable of binding to mRNA of AR, BTG3, CD55, ERBB3, FKBP5, FOXP1, LEP, SEPP1, SMAD4, and TP53 genes with high free energy by the formation of hydrogen bonds between canonical (G-C, A-U) and noncanonical (G-U, A-C) piRNA and mRNA nucleotide pairs were revealed. The organization of piRNA binding sites (BSs) in the mRNA of candidate genes was found to overlap nucleotide sequences to form clusters. Clusters of piRNA BSs were detected in the 5'-untranslated region, coding domain sequence, and 3'-untranslated region of mRNA. Due to the formation of piRNA binding site clusters, compaction of BSs occurs and competition between piRNAs for binding to mRNA of candidate EAC genes occurs. Associations of piRNA and candidate genes were selected for use as markers for the diagnosis of EAC.