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Comparative transcriptome analysis reveals ncRNA-mediated regulatory networks associated with muscle crispiness in grass carp.

Non-coding RNAs (ncRNAs) have been demonstrated to be involved in muscle development and to function as key regulators. However, the molecular mechanism underlying muscle crispiness in grass carp (GC) remains poorly understood, and whether these ncRNAs are involved in its regulation is still unknown. In the current investigation, differentially expressed (DE) RNAs (including lncRNAs, circRNAs, miRNAs, and mRNAs) were identified; concomitantly, target genes prediction was conducted, and functional and signaling pathway enrichment analyses were performed. Pathways related to muscle crispiness were identified, and the competitive endogenous RNA (ceRNA) (lncRNA/circRNA-miRNA-mRNA) regulatory network was further constructed. The results showed that a total of 126 DE-lncRNAs, 17 DE-circRNAs, 329 DE-miRNAs, and 442 DE-mRNAs were identified in muscle tissues of both the GC and crisp grass carp (CGC). GO and KEGG enrichment analyses revealed that target genes of DE-ncRNAs were significantly enriched in signaling pathways, including structural constituents of muscle, apoptosis, oxidative phosphorylation, and regulation of actin cytoskeleton, suggesting that these pathways may be involved in muscle texture remodeling. Subsequently, DE-RNAs enriched in related pathways were identified, and a core ceRNA regulation network comprising 3 lncRNAs, 4 circRNAs, 3 miRNAs, and 17 mRNAs was constructed. Additionally, 10 DE-RNAs from randomly selected groups were validated by qRT-PCR. Our findings not only provide scientific evidence elucidating the molecular mechanisms underlying muscle crispiness in GC but also establish a foundation for studying changes in muscle textural qualities across other fish species.

Animals

ceRNA network of lncRNAs and mRNAs in OSF-to-OSCC progression: Diagnostic biomarkers and functional pathways.

BACKGROUND: Oral submucous fibrosis (OSF) is a chronic potentially malignant disorder that can progress to oral squamous cell carcinoma (OSCC). Although dysregulated non-coding RNAs have been implicated in oral carcinogenesis, the competing endogenous RNA (ceRNA)-mediated regulatory mechanisms underlying OSF-to-OSCC progression remain poorly understood. This study aimed to identify candidate regulatory molecules and construct a putative lncRNA-miRNA-mRNA network associated with malignant transformation. METHODS: Publicly available microarray datasets (GSE117973 and GSE125866) were analyzed to identify differentially expressed genes between OSF and OSCC. Differentially expressed transcripts were classified into mRNAs and lncRNAs based on public transcript annotations. Highly correlated lncRNA-mRNA pairs were identified using Pearson correlation analysis and integrated with multiMiR-supported miRNA-mRNA interactions obtained from public databases to construct a putative ceRNA regulatory network. Functional characterization focused on apoptosis, epithelial-mesenchymal transition (EMT), and immune checkpoint-related pathways. Receiver operating characteristic (ROC) analysis was performed to evaluate diagnostic performance, and selected biomarkers were externally validated using The Cancer Genome Atlas (TCGA) OSCC cohort. RESULTS: Integrated transcriptomic analysis identified several dysregulated mRNAs and lncRNAs associated with OSF-to-OSCC progression. Network analysis highlighted TBC1D3B, RREB1, TEAD3, SREBF1, TMEM41B, FOXK2, and KIAA1958 as prominent hub genes within the putative regulatory network. Functional analyses demonstrated significant associations with apoptosis-, EMT-, and immune checkpoint-related genes, suggesting potential involvement in multiple biological processes contributing to malignant transformation. Several hub genes exhibited strong diagnostic performance, with ROC analysis yielding AUC values ranging from 0.891 to 1.000, indicating excellent discrimination between OSF and OSCC samples. External validation using TCGA further supported the relevance of the identified biomarkers in OSCC. CONCLUSIONS: This study provides a comprehensive transcriptomic framework describing putative lncRNA-miRNA-mRNA regulatory interactions associated with OSF progression to OSCC. The identified hub genes and regulatory networks represent candidate biomarkers for early detection and provide a foundation for future mechanistic and experimental validation. As the proposed ceRNA interactions are computationally inferred, further biological validation is required before clinical application.

RNA, Long Noncoding

Construction of circRNA-miRNA-mRNA regulatory networks in the intestine of turbot (Scophthalmus maximus) following Vibrio anguillarum infection.

Circular RNAs (circRNAs) play pivotal roles in post-transcriptional regulation by acting as molecular sponges for microRNAs (miRNAs) within the competitive endogenous RNA (ceRNA) network. However, the regulatory mechanisms in teleost immune responses remain poorly understood. In this study, circRNA-miRNA-mRNA networks were investigated in turbot (Scophthalmus maximus) following Vibrio anguillarum infection to elucidate host-pathogen interactions. Through high-throughput sequencing of intestinal tissues, a total of 50 differentially expressed circRNAs (DE-circRNAs) (18 at 2 hpi, 16 at 12 hpi, 16 at 48 hpi), 212 DE-miRNAs (11 at 2 hpi, 70 at 12 hpi, 15 at 48 hpi), and 1774 DE-mRNAs were identified. Functional enrichment analyses (GO/KEGG) revealed significant associations with immune pathways, including the MAPK signaling pathway and gap junction. An integrated circRNA-miRNA-mRNA regulatory network was constructed, highlighting key interactions including novel_circ_0002573/DE-miR-27a-3p/FGB and novel_circ_0002423/novel_347/GNE, which may regulate inflammatory and antibacterial responses. The expression patterns of selected circRNAs, miRNAs and mRNAs were validated using qRT-PCR, confirming the reliability of the sequencing results. Importantly, fibrinogen beta chain (FGB) and CXCR4/CXCL12 signaling were identified as critical immune modulators. These findings provide insights of the ceRNA regulatory networks involved in teleost intestinal immunity and provide potential molecular targets for selective breeding of disease resistance in this species.

Animals

CRISPR/Cas- and Argonaute-Based In Vivo Nucleic-Acid Imaging Technologies: Strategies, Challenges, and Perspectives.

Live-cell monitoring of sequence-specific nucleic acids is essential to understanding genome organization, RNA regulation, and disease progression. Clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR-associated protein (Cas) and Argonaute (Ago) systems provide programmable, guide-directed recognition of DNA or RNA and are increasingly used as platforms for in vivo bioimaging. This review summarizes the structural and mechanistic features of representative CRISPR and Ago effectors and discusses design strategies for sensitive, specific, and multiplexed imaging of genomic loci, extrachromosomal DNA, and endogenous RNA in living cells. We compare the analytical performance and limitations of CRISPR- and Ago-based imaging, with particular emphasis on the major technical and biological challenges affecting their accuracy, applicability, and reliability. Finally, this review offers insights into developing high-resolution and user-friendly bioimaging platforms for fundamental biology and future translational applications.

CRISPR

A Novel Long Noncoding RNA-LNC000133 Associated With Steroid-Induced Osteonecrosis of the Femoral Head Promotes Osteoblast Differentiation Through Bone Marrow Mesenchymal Stem Cells-Derived Exosomes Pathway: A Bioinformatics Validation and Detailed Mechanistic Study.

Steroid-induced osteonecrosis of the femoral head (SONFH) is a debilitating disease caused by glucocorticoid abuse, characterized by complex pathogenesis and unclear molecular mechanisms. Dysfunction of bone marrow mesenchymal stem cells (BMSCs) and their exosome-mediated signalling is a key contributor to SONFH, although the precise mechanisms remain to be elucidated. In this study, the differential expression profiles of long noncoding RNAs (lncRNAs), microRNAs (miRNAs) and messenger RNAs (mRNAs) in exosomes derived from human BMSCs (hBMSCs) obtained from patients with SONFH compared to controls with femoral neck fractures were identified. Through next-generation sequencing, a novel lncRNA, LNC000133, associated with SONFH was discovered. Using Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis and competing endogenous RNA (ceRNA) network construction, the LNC000133/miR-362-5p/TGF-β3/SMAD3/BMP2 signalling axis was established. The definitive expression, localization and full-length sequence of LNC000133 in BMSCs were subsequently validated by Northern blot, quantitative real-time polymerase chain reaction (qRT-PCR), fluorescence in situ hybridization (FISH) and rapid amplification of cDNA ends (RACE). Most notably, mechanistic studies demonstrated that LNC000133-modified BMSCs-derived exosomes were efficiently taken up by osteoblasts, which promoted proliferation and osteogenic differentiation by targeting the miR-362-5p/TGF-β3/SMAD3/BMP2 signalling pathway.

Humans

Transcriptome-wide N6-methyladenosine modification profiling of long non-coding RNAs in patients with recurrent implantation failure.

N6-methyladenosine (m6A) is involved in most biological processes and actively participates in the regulation of reproduction. According to recent research, long non-coding RNAs (lncRNAs) and their m6A modifications are involved in reproductive diseases. In the present study, using m6A-modified RNA immunoprecipitation sequencing (m6A-seq), we established the m6A methylation transcription profiles in patients with recurrent implantation failure (RIF) for the first time. There were 1443 significantly upregulated m6A peaks and 425 significantly downregulated m6A peaks in RIF. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analyses revealed that genes associated with differentially methylated lncRNAs are involved in the p53 signalling pathway and amino acid metabolism. The competing endogenous RNA network revealed a regulatory relationship between lncRNAs, microRNAs and messenger RNAs. We verified the m6A methylation abundances of lncRNAs by using m6A-RNA immunoprecipitation (MeRIP)-real-time polymerase chain reaction. This study lays a foundation for further exploration of the potential role of m6A modification in the pathogenesis of RIF.

Humans

LncRNA Profiling and ceRNA Network Construction of Intrauterine Exosomes in Goats During Embryo Implantation.

Exosomes have been shown to play an important role in embryo implantation, but the mechanism is still unclear. This study aimed to investigate the functional roles of lncRNAs in intrauterine exosomes in goat pregnancy. We used RNA-seq to identify the lncRNA profiles of exosomes obtained from goat uterine rinsing fluid at 5, 15, and 18 days of gestation. In addition, we performed weighted gene co-expression network analysis based on differentially expressed mRNAs (DEMs) and lncRNAs (DELs). Functional enrichment analyses of gene modules were conducted using Gene Ontology classification (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway. A lncRNA-miRNA-mRNA competing endogenous RNA (ceRNA) regulatory network was constructed based on predictive interaction derived from miRTarBase, miRDB and RNAhybrid databases. Altogether, 831 DELs were identified. GO and KEGG analysis showed that the target genes were enriched in processes associated with embryo implantation, such as signaling receptor activity, binding and immune response. Nine functional co-expression modules were enriched in various biological processes, such as metabolic pathways, protein transport, cell cycle and VEGF signaling pathway. Additionally, 12 lncRNA-mediated ceRNA networks were constructed. Our results demonstrate that exosomal lncRNAs in uterine flushing fluid exhibit dynamic changes across gestational stages and play an important role in regulating the uterine microenvironment during embryo implantation. These findings provide a foundational basis for screening exosome-derived lncRNAs that influence embryo implantation and contribute to elucidating the mechanistic roles of lncRNAs in exosome-mediated processes during early pregnancy.

embryo implantation

lncRNA JPX promotes radioresistance in nasopharyngeal carcinoma via the miR-1301-3p/PIK3R2-mediated autophagy pathway.

BACKGROUND: Nasopharyngeal carcinoma (NPC) represents an aggressive head and neck malignancy with high metastatic potential. Radioresistance remains a major therapeutic obstacle associated with poor prognosis. Although the long non-coding RNA (lncRNA) JPX has been implicated in various cancers, its specific role in NPC radioresistance requires further elucidation. This study aimed to investigate whether JPX modulates radiosensitivity through autophagy regulation and to delineate the underlying molecular mechanisms. METHODS: JPX expression was analyzed in NPC cell lines and The Cancer Genome Atlas (TCGA) datasets, with subcellular localization determined through cellular fractionation. Functional characterization was performed using short hairpin RNA (shRNA)-mediated knockdown in CNE-2 and HONE-1 cell lines. Radiosensitivity was evaluated by clonogenic survival assays at a clinically relevant radiation dose, with cell viability assessed by MTT as a screening measure. while autophagy activity was assessed through Western blot analysis of LC3-II and p62. Molecular interactions were validated using dual-luciferase reporter and RNA immunoprecipitation (RIP) assays. RESULTS: JPX was significantly upregulated in head and neck squamous cell carcinoma (HNSCC) tissues and NPC cell lines, showing predominant cytoplasmic localization. Clinical association analysis in the TCGA-HNSCC cohort revealed that elevated JPX expression correlated with advanced tumor stage and poor overall survival, although NPC-specific clinical validation remains to be established. Genetic silencing of JPX attenuated autophagic flux and enhanced radiosensitivity. Mechanistic investigations revealed that JPX functions as a competitive endogenous RNA (ceRNA) functionally associating with miR-1301-3p, thereby alleviating miR-1301-3p-mediated repression of PIK3R2 and subsequently activating pro-survival autophagy pathways. CONCLUSIONS: The findings demonstrate that JPX promotes radioresistance in NPC through a ceRNA mechanism involving the miR-1301-3p/PIK3R2/autophagy regulatory axis. The JPX/miR-1301-3p/PIK3R2 axis thus emerges as a potential mechanistic candidate for radiosensitization; however, this notion remains strictly provisional and requires rigorous validation in authenticated NPC models, in vivo systems, and patient-derived samples before any translational consideration can be justified. Despite the cell line limitations acknowledged herein, our findings provide a mechanistic framework for understanding JPX-mediated radioresistance that warrants further investigation in more physiologically relevant models.

JPX

Sodium Overload-Related Molecular Subtypes and a Four-Gene Prognostic Signature Predict Survival, Immune Landscape, and Therapeutic Response in Acute Myeloid Leukemia.

Sodium overload has recently emerged as a critical metabolic stressor involved in cancer progression; however, its molecular characteristics and clinical relevance in acute myeloid leukemia (AML) remain unexplored. RNA-seq data sets, clinical annotations, and mutational profiles of AML patients were annotations from The Cancer Genome Atlas and integrated with Genotype-Tissue Expression normal samples. Sodium overload-related genes (SORGs) were obtained from GeneCards. Differentially expressed SORGs (DESORGs) screened by applying the limma statistical model, followed by univariate Cox proportional hazards regression, consensus clustering, functional enrichment, immune infiltration analysis, and pathway evaluation. A prognostic signature was developed through least absolute shrinkage and selection operator regression followed by multivariate Cox modeling. The model's performance was further verified in two external GEO data sets (GSE71014 and GSE37642). Nomogram construction, subgroup analysis, tumor mutational burden (TMB) assessment, drug sensitivity prediction, transcription factor (TF) analysis, and competing endogenous RNA (ceRNA) network analyses were also performed. A total of 57 DESORGs were identified, and 2 sodium overload-related molecular subtypes exhibited distinct survival, immune infiltration, and inflammatory pathway activation. A robust four-gene signature (DOCK1, GABRE, HTR7, ACSM1) stratified patients into high- and low-risk categories with significantly different survival across training and validation cohorts. High-risk patients displayed increased immune infiltration, higher TMB, reduced sensitivity to multiple chemotherapeutic drugs, and inferior predicted response to PD-L1 blockade. TF and ceRNA networks revealed multilayered transcriptional and post-transcriptional regulation of the signature genes. This study identifies sodium overload-related molecular heterogeneity in AML and establishes a validated four-gene prognostic signature that integrates genomic, immunologic, and therapeutic features, offering potential utility for personalized risk assessment and treatment optimization.

Humans

Circular RNA profiling reveals an abundant circLMO7 that regulates myoblasts differentiation and survival by sponging miR-378a-3p.

Circular RNAs (circRNAs) have been identified from various tissues and species, but their regulatory functions during developmental processes are not well understood. We examined circRNA expression profiles of two developmental stages of bovine skeletal muscle (embryonic and adult musculus longissimus) to provide first insights into their potential involvement in bovine myogenesis. We identified 12 981 circRNAs and annotated them to the Bos taurus reference genome, including 530 circular intronic RNAs (ciRNAs). One parental gene could generate multiple circRNA isoforms, with only one or two isoforms being expressed at higher expression levels. Also, several host genes produced different isoforms when comparing development stages. Most circRNA candidates contained two to seven exons, and genomic distances to back-splicing sites were usually less than 50 kb. The length of upstream or downstream flanking introns was usually less than 105 nt (mean≈11 000 nt). Several circRNAs differed in abundance between developmental stages, and real-time quantitative PCR (qPCR) analysis largely confirmed differential expression of the 17 circRNAs included in this analysis. The second part of our study characterized the role of circLMO7-one of the most down-regulated circRNAs when comparing adult to embryonic muscle tissue-in bovine muscle development. Overexpression of circLMO7 inhibited the differentiation of primary bovine myoblasts, and it appears to function as a competing endogenous RNA for miR-378a-3p, whose involvement in bovine muscle development has been characterized beforehand. Congruent with our interpretation, circLMO7 increased the number of myoblasts in the S-phase of the cell cycle and decreased the proportion of cells in the G0/G1 phase. Moreover, it promoted the proliferation of myoblasts and protected them from apoptosis. Our study provides novel insights into the regulatory mechanisms underlying skeletal muscle development and identifies a number of circRNAs whose regulatory potential will need to be explored in the future.

Animals

Deciphering differential mRNA and lncRNA expression profiles in response to PEG simulated drought stress in cucumber (Cucumis sativus L.).

Cucumber (Cucumis sativus L.), a vital fruit vegetable of the Cucurbitaceae family, originated in India ∼ 3000 years ago. It is widely used in the culinary, therapeutic, and cosmetic sectors. Cucumber cultivation is significantly impacted by drought stress, especially in arid and semi-arid regions. This study investigates the molecular response to drought using two contrasting cucumber lines: WBC-23-2 (drought-tolerant) and DGPC-59 (drought-sensitive). Drought was simulated using polyethylene glycol (PEG), and effects on physiological and biochemical traits were evaluated. The tolerant line exhibited reduced leaf wilting and higher relative water content (RWC). Based on these physiological markers, transcriptomic profiling was employed to identify the underlying regulatory networks. Analysis identified 4,736 DEGs, suggesting that the tolerant line's superior resilience is driven by preferential activation of genes involved in photosynthesis and glutathione metabolism. Conversely, the sensitive genotype showed enrichment in organonitrogen compound catabolism and water deprivation response. This divergence is further reflected in the regulation of 155 transcription factors (TFs) across various families, indicating distinct regulatory architectures between the two lines. Additionally, 774 drought-responsive long non-coding RNAs (lncRNAs) were identified, acting via cis, trans, and competing endogenous RNA (ceRNA) mechanisms to modulate gene expression. Key candidate genes associated with drought tolerance included WAT1-related protein At5g64700, thaumatin-like protein, berberine bridge enzyme-like 18, probable WRKY transcription factor, and pathogenesis-related protein 1. This study reveals a complex regulatory network of mRNAs, lncRNAs, and TFs underlying drought response and provides a valuable foundation for breeding drought-resilient cucumber cultivars. A web-based genomic resource, CsDTDb, has been developed and made publicly available to facilitate future functional genomics studies related to drought tolerance in cucumber.

DEGs

Screening and identification of the ncRNA-mRNA regulatory network associated with DNA methylation in goose embryonic myoblasts.

BACKGROUND: Local goose breeds Shitou and Wuzong exhibit distinct growth rates, implying divergent embryonic muscle development. This study used embryonic myoblasts from the Magang goose, an established model with superior growth traits, to explore the underlying common regulatory mechanisms. Extending our previous findings that 5-AZA (DNA methylation inhibitor) and BC339 (DNA hydroxylation inhibitor) oppositely affect myoblast proliferation and differentiation, we performed whole-transcriptome sequencing on inhibitor-treated goose embryonic myoblasts. This aimed to identify DNA methylation-mediated ncRNA-mRNA networks governing myoblast fate, with key interactions being functionally validated. RESULT: 5-AZA significantly promotes cell proliferation and differentiation by inhibiting DNA methyltransferase activity and reducing DNA methylation levels, whereas BC339 significantly suppresses cell proliferation and differentiation by inhibiting demethylation and increasing DNA methylation levels. Specifically, we identified 6,309 mRNAs, 579 lncRNAs, 194 miRNAs, and 825 circRNAs that were differentially expressed in response to 5-AZA and BC339 treatment. Based on GO and KEGG enrichment analyses, differentially expressed genes related to muscle development were selected to construct a ceRNA network. This network comprises 5 differentially expressed lncRNAs (DELs: MSTRG.17572.1, XR_001211738.1, MSTRG.1886.1, XR_001212555.1, MSTRG.8995.2), 2 differentially expressed circRNAs (DECs: novel_circ_029953, novel_circ_017636), 11 differentially expressed miRNAs (DEMs: miR-383-x, miR-10174-y, miR-191-x, miR-24-x, miR-9619-y, novel-m0303-5p, novel-m0105-3p, miR-204-x, miR-211-z, novel-m0075, miR-26-y), 5 differentially expressed genes (DEGs: KIF3A, CCND1, PPM1A, Table 2, TGFBR1), forming a total of 24 interactions. This study identified miR-9619-y as a critical negative regulator of goose embryonic myoblast development through targeted inhibition of CCND1. Dual-luciferase reporter assays confirmed the direct binding of miR-9619-y to the 3'-untranslated region of CCND1. Functional experiments demonstrated that overexpression of miR-9619-y significantly reduced the EdU-positive cell ratio and myotube area percentage, accompanied by cell cycle arrest at the G0/G1 phase. Conversely, inhibition of miR-9619-y promoted myoblast proliferation and differentiation while decreasing the proportion of cells in G0/G1 phase. During the proliferation stage, miR-9619-y overexpression significantly suppressed CCND1 expression at both mRNA and protein levels, down-regulated MyoD expression, and reduced Myf5 mRNA abundance; whereas miR-9619-y inhibition up-regulated these genes and their corresponding proteins. During the differentiation stage, overexpression of miR-9619-y similarly decreased the mRNA levels of CCND1, Myh1, and MyoG, as well as the protein levels of MyHC and CCND1, with inhibition producing the opposite effects. CONCLUSION: In this study, we predicted a ceRNA network based on bioinformatics analysis governing goose embryonic myoblast development, identifying key molecular components including mRNAs, miRNAs, lncRNAs, and circRNAs, along with 24 regulatory axes. Functional experiments further demonstrated that miR-9619-y arrests cell cycle progression and negatively regulates the proliferation and differentiation of goose embryonic myoblasts, as evidenced by its impact on both the mRNA and protein expression of key myogenic factors through targeted inhibition of CCND1. These findings, together with the bioinformatically predicted ceRNA network, suggest potential complex post-transcriptional regulatory mechanisms underlying myogenesis in geese and offer candidate molecular targets for genetic improvement of meat production performance in waterfowl breeding programs.

Animals

Determining small RNA-interacting proteomes using endogenously modified tRNA-derived RNAs.

tRNA-derived RNAs (tDRs), resulting from enzyme-mediated hydrolysis of tRNAs, have been implicated as active small RNAs in various molecular processes. While the molecular modes of action for these small RNAs remain unclear, attempts to decipher the mechanistic details of tDR functionality have mostly used synthetic tDR sequences. Since parental tRNAs are extensively post-transcriptionally modified, tDR functionality is likely affected by chemical modifications. To help approach the biological function of endogenously modified tDRs, this contribution details a protocol that allows purifying specific tDRs carrying post-transcriptional modifications from both in vivo and in vitro sources. Purified tDRs can be used for various downstream applications including differential affinity capture of tDR-binding proteins, the details of which are also described in this contribution.

RNA, Transfer

DNA-guided CRISPR-Cas12 for cellular RNA targeting.

Here, we present ΨDNA, a DNA-based guide that enables RNA targeting by Cas12 nucleases, overcoming the traditional reliance on RNA-guided systems. We engineer ΨDNA to mimic a CRISPR RNA (crRNA) scaffold in reverse orientation, allowing AsCas12a and Cas12i1 to recognize RNA and trigger strong single-stranded DNA trans-cleavage for sensitive detection of diverse RNA species, including 100% accurate hepatitis C virus RNA detection in clinical samples. ΨDNA also achieves 70-95% multiplex knockdown of endogenous intracellular RNA transcripts through ribosome stalling across multiple human cell lines. Mechanistic studies reveal that activity depends on a stem loop that stabilizes a catalytically competent Cas12-ΨDNA-RNA complex. Lastly, codelivery of crRNA and ΨDNA enables simultaneous DNA editing and RNA knockdown with a single effector and modular fusions of different enzymes to AsCas12a extend ΨDNA to RNase H-mediated RNA degradation and METTL3-based epitranscriptomic editing. Together, ΨDNA guides constitute an adaptable toolkit that extends Cas12 systems beyond genome editing and diagnostics to enable precise, programmable control of cellular transcriptomes and their epitranscriptomic marks.

Journal Article

Screening of biomarkers related to lung adenocarcinoma based on construction of ceRNA regulation network.

BACKGROUND: Lung adenocarcinoma (LUAD) is a common malignant tumor with a poor prognosis and limited effective therapeutic targets. The underlying molecular regulatory mechanisms driving its progression remain largely unclear. The study objectives were to build a circRNA-miRNA-mRNA ceRNA regulation network of LUAD and to identify miRNAs and mRNAs significantly related to the prognosis . METHODS: The gene expression data and GSE101684 were downloaded from the UCSC Xene and NCBI-GEO databases, respectively. The differentially expressed RNAs (DEcircRNAs, DEmiRNAs, and DEmRNAs; DERs) were obtained by the Limma package in R. Then, the differential LUAD-related genes were identified, and the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways of the differential LUAD-related genes were analyzed. Moreover, the circRNA-miRNA-mRNA ceRNA network of LUAD was built. The Kaplan-Meier (K-M) survival curve analysis of ceRNA network nodes was performed. In addition, the proliferation-related ceRNA network was built. RESULTS: A total of 382 DEcircRNAs, 1907 DEmRNAs and 156 DEmiRNAs were acquired. A total of 245 differential LUAD-related genes were acquired, which were significantly associated with 189 GO biological processes (BP) and 17 KEGG pathways. Moreover, the ceRNA network of LUAD was built. The K-M survival curve analysis of ceRNA network nodes revealed that a total of 2 miRNAs (hsa-miR-96-5p and hsa-miR-125b-2-3p) and 22 mRNAs (CGNL1, CTHRC1, TK1, etc) were significantly related to the prognosis. mRNAs were significantly enriched in 92 GO BPs (such as cell division, cell adhesion) and 9 KEGG pathways (such as cell cycle, HTLV-1 infection). In addition, the proliferation-related ceRNA network was built. CONCLUSION: This research built a ceRNA regulation network of LUAD and is of great significance for identifying biomarkers related to the prognosis in LUAD.

Humans

Donor transcription suppresses D-loops in cis and promotes genome stability.

DNA is a substrate for competing protein-mediated activities. Whether and how transcription and the synaptic steps of recombination collide or are coordinated has not been investigated. Here, using a controlled break induction system and physical detection of D-loop DNA joint molecules in S. cerevisiae, we show that donor transcription by RNA polymerase II strongly and acutely suppresses D-loops in cis. The extent of this suppression depends on the orientation of transcription, suggesting the preferential usage of one end for the repair of DNA break in transcribed regions. Transcription-mediated D-loop suppression does not rely on endogenous transcription factors, the RNA product, or RNA:DNA hybrids. It is independent of, and can be more potent than the conserved trans D-loop-disruption factors Sgs1-Top3-Rmi1BLM-TOPO3α-RMI1/2, Mph1FANCM, and Srs2. This transcription-mediated control promotes genome maintenance by inhibiting ectopic recombination and multi-invasion-induced rearrangements, while authorizing allelic inter-homolog repair. These findings reveal the prioritization between two universal DNA-dependent processes and its role in promoting genome stability.

Genomic Instability

Identification of highly immunogenic endogenous dsRNAs from cellular MDA5 filaments.

ADAR1 converts adenosine to inosine in endogenous double-stranded RNAs (dsRNAs) to prevent excessive MDA5-driven interferon-stimulated gene expression. The source of endogenous immunogenic dsRNAs remains enigmatic because only a small fraction of ADAR1 substrates activate MDA5, and cellular MDA5 filaments have not been isolated. Here, we couple affinity purification of cellular MDA5 filaments with RNA sequencing to define immunogenic endogenous dsRNAs. Greater than 84% of dsRNAs suppressed by combined DDX3X RNA helicase and ADAR1 base-editing activities were present in MDA5 filaments, compared to less than 1% of dsRNA substrates acted on by ADAR1 alone. Dual substrate dsRNAs consisted of inverted repeats embedded in 3'-UTRs with high base-pair complementarity and longer intervening sequences between repeats, with a minor contribution coming from intermolecular dsRNAs formed by sense and antisense transcripts. Moreover, the majority of dual substrate immunogenic dsRNAs were hyperedited in DDX3X mutant cancers. This reveals the identity of endogenous immunogenic dsRNAs and quality control mechanisms underlying their suppression.

Journal Article

Comprehensive analysis of differentially expressed mRNAs, lncRNAs, and miRNAs involved in ovarian differentiation and development in Qihe gibel carp (Carassius gibelio var. Qihe).

Qihe gibel carp (Carassius gibelio var. Qihe) exhibits diverse reproductive modes including gynogenesis and sexual reproduction, yet the molecular mechanisms of ovarian differentiation remain poorly understood. Ovarian tissues at 20, 30, and 60 days after hatching (dah), representing key stages covering early ovarian differentiation and primary oocyte growth, were subjected to whole-transcriptome sequencing. A total of 27,259 mRNAs, 2622 lncRNAs, and 2467 miRNAs were differentially expressed. Cell cycle, transcription, translation, and DNA replication pathways were significantly upregulated from 20 to 60 dah. Oocyte meiosis was enriched from 20 and 30 dah, whereas metabolic pathways (lipid, carbohydrate, and nucleotide metabolism) were enriched from 30 to 60 dah, indicating sequential progression from meiosis initiation to primary oocyte growth with nutrient synthesis. Hub lncRNAs and key ceRNA networks (e.g., MSTRG.28669.5-miR-221-ccnb2) were identified. This study provides the first comprehensive characterization of ncRNA-mediated regulation and ceRNA networks during ovarian development in Qihe gibel carp, establishing a foundation for understanding ovarian differentiation in this species.

Animals