Search Results (420)

MicroRNAs (miRNAs) are small non-coding RNAs that play pivotal roles in post-transcriptional gene regulation, influencing development, differentiation, and disease pathogenesis. Since their discovery in 1993, miRNAs have been recognized for their evolutionary conservation and pleiotropic effects, with the 2024 Nobel Prize underscoring their significance in post-transcriptional regulation via the RNA interference (RNAi) pathway. This review synthesizes the complete life cycle of miRNAs—from transcription and processing to function and decay—emphasizing regulatory mechanisms and their implications in human diseases, particularly cancer. We discuss how epitranscriptomic modifications influence miRNA biogenesis and activity, explore their nuclear and mitochondrial functions, and address emerging challenges in miRNA-based therapeutics, including the expanding small RNA landscape such as tRNA-derived small RNAs (tsRNAs), and Argonaute (AGO)-independent activities. Despite hurdles such as modest multi-target effects, off-target interactions, and delivery challenges, miRNAs remain promising as both biomarkers and therapeutic agents, underscoring the need for sustained research to bridge preclinical insights with clinical applications. Full article

Grafting is the process of joining parts of two plants, allowing the exchange of molecules such as small RNAs (including microRNAs and small interfering RNAs), messenger RNAs, and proteins between the rootstock and the scion. Genome editing by grafting exploits RNAs, such as tRNA-like sequences (TLS motifs), to deliver the components (RNA) of the clustered regularly interspaced short palindromic repeats (CRISPR)-associated protein 9 (Cas9) system from transgenic rootstock to wild-type scion. The complex Cas9 protein and sgRNA-TLS produced in the scion perform the desired modification without the integration of foreign DNA in the plant genome, resulting in heritable transgene-free genome editing. In this review, we examine the current state of the art of this innovation and how it helps address regulatory problems, improves crop recovery and selection, exceeds the usage of viral vectors, and may reduce potential off-target effects. We also discuss the promise of genome editing by grafting for plants recalcitrant to in vitro culture and for agamic-propagated species that must maintain heterozygosity for plant productivity, fruit quality, and adaptation. Furthermore, we explore the limitations of this technique, including variable efficiency, graft incompatibility among genotypes, and challenges in large-scale application, while highlighting its considerable potential for further improvement and future broader applications for crop breeding. Full article

An emerging area of microbial biology focuses on oligonucleotides excised from functional RNAs and subsequently fulfilling an independent cellular role. Some of these products are subjected to modifications that may expand their functional inventory. Here, we applied a differential analysis of intra- and extracellular RNA fragments produced by wild-type Escherichia coli and its dps-null mutant and discovered leucine tRNA fragments with random 3′-terminal extensions among oligonucleotides with Dps-dependent secretion. We observed an exclusive intracellular enrichment of modified LeuT(VPQ) tRNA fragments compared to secretomes, with abundance level dependent on growth medium and the presence of competing bacteria. To assess the pervasiveness of this phenomenon, we developed a custom computational pipeline for detecting variable RNA termini in RNA-seq data. Beyond LeuT(VPQ) tRNA fragments, several other genomic loci yielded oligos with highly heterogeneous ends, indicating that terminal elongation, most prevalent in LeuT(VPQ), is not exclusive to these fragments. Ex vivo testing using synthetic LeuT(VPQ) analogs revealed their stimulatory effect on the persistence of multiple taxa in an artificial microbiome, which was attenuated by 3′-end elongation. We propose that non-template extensions may serve to broaden the spectrum of target molecules for elimination of unused mRNAs by an interference-like mechanism or to generate sequences absent from the E. coli genome as part of a primitive defense system. Full article

Aminoacyl-tRNA synthetases (AARSs), traditionally recognized for their essential role in protein synthesis, are now emerging as critical players in cancer pathogenesis through translation-independent functions. Lactate-derived lactylation, a post-translational modification, plays an increasingly important role in tumorigenesis in the context of high levels of lactate in tumor cells due to the Warburg effect. Current research has highlighted AARS1/2 as lactate sensors and lactyltransferases that catalyze global lysine lactylation in cancer cells and promote cancer proliferation, providing a new perspective for cancer therapy. This review synthesizes the canonical and non-canonical functions of AARS1/2, with a particular focus on their lactylation-related mechanisms; details how lactylation acts as a mechanistic bridge linking AARS1/2 to diverse oncogenic signaling pathways, thereby promoting cancer hallmarks such as metabolic reprogramming, uncontrolled proliferation, immune escape, and therapy resistance; and proposes strategies to target AARS1/2 or modulate relative lactylation, offering a potential avenue to translate these insights into effective cancer therapies. Full article

Our previous studies identified the Gcp/TsaD protein as essential for Staphylococcus aureus survival and implicated it in tRNA modification. Here, we demonstrate its broader role in bacterial physiology. Through a morphological analysis, RNA sequencing, network-based bioinformatics, and antibiotic susceptibility testing, we show that Gcp/TsaD influences cell morphology, cell wall integrity, transcriptional regulation, virulence, and antibiotic response. Gcp/TsaD depletion caused reduced cell size and increased cell wall thickness, suggesting its roles in cell division and peptidoglycan biosynthesis. The kinetic transcriptomic analysis revealed widespread changes in gene expression, particularly in the translation and amino acid biosynthesis pathways, supporting its function in maintaining translational fidelity via tRNA modification. Its depletion also upregulated the genes involved in cell envelope biosynthesis, including capsule formation, enhancing resistance to antimicrobial peptides, while downregulating the key virulence genes, indicating a role in pathogenicity. Functionally, the Gcp/TsaD-deficient cells were more susceptible to fosfomycin, reinforcing its importance in cell wall integrity. Together, these findings highlight the multifaceted contribution of Gcp/TsaD to S. aureus physiology and underscore its potential as a therapeutic target, particularly against antibiotic-resistant strains. Full article

Thefilamentous fungus Trichoderma reesei is renowned for its exceptional ability to secrete cellulolytic enzymes, which play a crucial role in the hydrolysis of lignocellulose biomass. The expression of fungal cellulases is meticulously regulated at the transcriptional level, depending on the carbon source available in the medium. To obtain new insights into the transcriptional network controlling cellulase expression in T. reesei, we analyzed RNA-Seq data and identified and characterized a new transcription factor, Rme1, that regulates the expression of cellulolytic genes. Combining functional genomics and protein-DNA interaction assay, we showed that Rme1 acts as a repressor of cellulase production in T. reesei by directly regulating two critical genes involved in cellulose degradation: the cellobiohydrolase cel7a and the carbon catabolite repressor cre1. This is the first report of a transcription factor regulating Cre1. This study contributes to a better understanding of the complex regulation of the cellulolytic system of T. reesei and may be useful for the genetic modification of strains for the biorefinery industry. Full article

Pseudouridylation, the most abundant RNA modification, plays a critical role in modulating RNA structure, stability, and function. Among the family of pseudouridine synthases, Pseudouridine Synthase 7 (PUS7) has recently gained attention for its emerging roles in human health and disease. Originally characterized for its function in modifying tRNA and small non-coding RNAs, PUS7 is now recognized as a dynamic regulator of mRNA pseudouridylation, influencing gene expression at the post-transcriptional level. Aberrant expressions or activity of PUS7 have been linked to a variety of pathological conditions, including cancers such as colon cancer, glioblastoma, pancreatic cancer, and neuroblastoma, as well as potential roles in neurodevelopmental disorders and immune regulation. Through mechanisms involving translational reprogramming, stress adaptation, and epitranscriptomic remodeling, PUS7 contributes to disease progression and cellular plasticity. This review summarizes the current understanding of PUS7 biology, its functional relevance in the contexts of cancer progression, and the growing interest in targeting RNA-modifying enzymes for therapeutic intervention. Uncovering the full spectrum of PUS7-mediated pseudouridylation and its downstream effects holds promise for advancing our understanding of RNA-based regulation in human diseases, including gynecological disorders. Full article

RNA modifications regulate diverse aspects of transcripts’ function and stability. Among these, N1-methyladenine (m¹A) is a reversible mark primarily installed by the TRMT6/TRMT61A methyltransferase on tRNA, though it is also found on other RNA types. m¹A has been implicated in protecting mRNAs during acute protein misfolding stress. However, the role of m¹A under chronic proteotoxic conditions, such as intracellular amyloid aggregation, remains poorly understood. To address this gap, we examined the effects of reduced N1-adenine methylation in human cells undergoing amyloidogenesis. Suppression of the methyltransferase TRMT61A or overexpression of the m¹A-specific demethylase ALKBH3 enhanced amyloid aggregation. A deficiency of N1-adenine methylation also impaired the expression of a reporter mRNA-encoded protein, highlighting the protective role of m¹A in safeguarding transcript functionality. Proteomic analysis of amyloid aggregates from TRMT61A-deficient cells revealed increased co-aggregation of bystander proteins, particularly those with known RNA-binding activity. At the same time, the aggregates from methylation-deficient cells contained elevated levels of mRNAs. Collectively, our findings support a role for m¹A in preventing RNA entanglement within aggregates and limiting RNA-mediated propagation of protein co-aggregation. Full article

Thrombospondin-1 potently inhibits T cell activation by engaging its cell surface receptor CD47. This inhibitory signal requires glycosaminoglycan modification of CD47. CD47 also regulates the composition of RNAs in extracellular vesicles released by T cells and their functional activities. Because CD47 is also present in extracellular vesicles, we examined the effect of T cell activation on CD47 glycoforms in T cells and extracellular vesicles released by these cells. Activation increased both heparan and chondroitin sulfate biosynthesis by globally inducing mRNA levels of the respective glycosaminoglycan synthases and sulfotransferases. T cell activation in the presence of thrombospondin-1 inhibited induction of these biosynthetic enzymes, but not in cells lacking CD47. Therefore, CD47 signaling controls its own post-translational modification by glycosaminoglycans that are required for thrombospondin-1 signaling. Activation of Jurkat T lymphoblasts and primary CD4 and CD8 T cells increased the release of proteoglycan isoforms of CD47 and amyloid precursor-like protein-2 associated with extracellular vesicles and smaller macromolecular complexes. However, cell surface levels of CD47 were minimally changed during activation. BJAB and RAJI B cell lines also produced CD47⁺ extracellular vesicles and showed increased release of highly glycosylated CD47 following B cell receptor engagement. Therefore, T and B lymphocyte activation results in a selective increase in the synthesis and release of extracellular vesicles containing proteoglycan isoforms of CD47. Full article

Genitourinary (GU) cancers, including prostate, bladder, and renal cancers, represent a significant burden on global health. Conventional treatments, while effective in certain contexts, face limitations due to tumor heterogeneity, therapeutic resistance, and relapse. Recent advances in cancer immunotherapy, particularly in the development of personalized mRNA and DNA-based vaccines, have opened new avenues for precise and durable antitumor responses. These vaccines are being developed to leverage neoantigen identification and next-generation sequencing technologies, with the goal of tailoring immunotherapeutic interventions to individual tumor profiles. mRNA vaccines offer rapid, non-integrative, and scalable, with encouraging results reported in infectious diseases and early-phase cancer trials. DNA vaccines, known for their stability and ease of modification, show promise in generating robust cytotoxic T-cell responses. This review discusses the current landscape, preclinical findings, and ongoing clinical trials of mRNA and DNA-based vaccines in GU cancers, highlighting delivery technologies, combination strategies with immune checkpoint inhibitors, and future challenges, including tumor immune evasion and regulatory hurdles. Integrating immunogenomics and artificial intelligence into vaccine design is poised to further enhance precision in cancer vaccine development. As GU malignancies remain a leading cause of cancer-related morbidity and mortality, mRNA and DNA vaccine strategies represent a promising and rapidly evolving area of investigation in oncology. Full article

MicroRNAs (miRNAs) are key post-transcriptional regulators controlling gene expression across several cellular processes, including development, proliferation, and apoptosis. Their biogenesis involves a multi-step pathway, including the processing of primary transcripts and the assembly of the RNA-Induced Silencing Complex (RISC) with Argonaute (AGO) proteins at its core. This review provides a comprehensive overview of the molecular dynamics of miRNA-loaded RISC (miRISC), focusing on the post-translational modifications, the interactors of AGOs and the mechanisms that fine-tune and coordinate miRISC activity. The composition of miRISC influences AGO stability, localization, and silencing efficiency, thereby maintaining cellular homeostasis and development and mediating the response to various types of cellular stress. Uncommon regulatory mechanisms, including AGO modifications during, e.g., hypoxia or Type 2 T cell responses and miRISC functionality, with myriad RNA-binding proteins (RBPs), will be discussed. This review aims at highlighting the recent advances in the understanding of the intricate regulation of miRISC-driven gene silencing. Full article

Bariatric surgery is considered the most effective treatment for obesity and its associated metabolic disorders, yet the underlying mechanisms are only partially understood. Evidence suggests that the gut microbiota plays an important role in metabolic regulation and can be significantly altered by bariatric and metabolic procedures. This prospective, single-center study aimed to evaluate the dynamic changes in the gut microbiota composition and diversity in obese patients undergoing two types of bariatric surgery: laparoscopic sleeve gastrectomy (LSG) and Roux-en-Y gastric bypass (RYGB). Fecal samples were collected at three time points—before surgery (T0), and at 3 (T3) and 6 months (T6) postoperatively—and analyzed using 16S rRNA gene sequencing targeting the V3–V4 regions with Illumina technology. Significant shifts in microbial diversity and structure were observed over time, indicating a trend toward microbiota normalization post-surgery. Notable changes included a reduction in the Firmicutes/Bacteroidetes ratio and increased relative abundance of Actinobacteria, Proteobacteria, and Verrucomicrobia. These alterations occurred in parallel with improvements in body mass index (BMI) and metabolic parameters. Our findings suggest that bariatric surgery induces favorable and sustained modifications in the gut microbiota, which may contribute to its therapeutic effects in obesity management. Full article

Benzene, a well-established human carcinogen and major industrial pollutant, poses significant health risks through occupational exposure due to its no-threshold effect, leading to multi-system damage involving the hematopoietic, nervous, and immune systems. This makes the investigation of its toxic mechanisms crucial for precise prevention and control of its health impacts. Programmed cell death (PCD), an orderly and regulated form of cellular demise controlled by specific intracellular genes in response to various stimuli, has emerged as a key pathway where dysfunction may underlie benzene-induced toxicity. This review systematically integrates evidence linking benzene toxicity to PCD dysregulation, revealing that benzene and its metabolites induce abnormal subtypes of PCD (apoptosis, autophagy, ferroptosis) in hematopoietic cells. This occurs through mechanisms including activation of Caspase pathways, regulation of long non-coding RNAs, and epigenetic modifications, with recent research highlighting the IRP1-DHODH-ALOX12 ferroptosis axis and oxidative stress–epigenetic interactions as pivotal. Additionally, this review describes a comprehensive monitoring system for early toxic effects comprising benzene exposure biomarkers (urinary t,t-muconic acid (t,t-MA), S-phenylmercapturic acid (S-PMA)), PCD-related molecules (Caspase-3, let-7e-5p, ACSL1), oxidative stress indicators (8-OHdG), and genetic damage markers (micronuclei, p14ARF methylation), with correlative analyses between PCD mechanisms and benzene toxicity elaborated to underscore their integrative roles in risk assessment. Furthermore, the review details analytical techniques for these biomarkers, including direct benzene detection methods—direct headspace gas chromatography with flame ionization detection (DHGC-FID), liquid chromatography-tandem mass spectrometry (LC-MS/MS), and portable headspace sampling (Portable HS)—alongside molecular imprinting and fluorescence probe technologies, as well as methodologies for toxic effect markers such as live-cell imaging, electrochemical techniques, methylation-specific PCR (MSP), and Western blotting, providing technical frameworks for mechanistic studies and translational applications. By synthesizing current evidence and mechanistic insights, this work offers novel perspectives on benzene toxicity through the PCD lens, identifies potential therapeutic targets associated with PCD dysregulation, and ultimately establishes a theoretical foundation for developing interventional strategies against benzene-induced toxicity while emphasizing the translational value of mechanistic research in occupational and environmental health. Full article

Background/Objectives: Messenger RNA (mRNA) modifications regulate key steps in gene expression, including splicing, translation, and stability. Despite over 300 known RNA modifications, the relatively small subset occurring in mRNA remains understudied compared with tRNA and rRNA. This review aims to systematically evaluate 15 known naturally occurring mRNA-specific modifications, rank them by publication frequency, and highlight emerging frontiers in epitranscriptomics, including discovering new naturally occurring mRNA modifications and environmental RNA (eRNA) epitranscriptomics. Methods: We conducted a structured literature review of PubMed-indexed publications to rank mRNA modifications by citation prevalence. Key modifications such as m⁶A, m⁵C, Ψ, and m¹A were analyzed in terms of enzymatic machinery (“writers,” “erasers,” and “readers”), molecular functions, and physiological relevance. We also reviewed technological advances, with a focus on nanopore sequencing for detection of RNA modifications in native and environmental contexts. Results: The modification m⁶A was identified as the most studied mRNA modification, followed by Ψ, m⁵C, and A-to-I editing (inosine). These modifications influence diverse mRNA processes, including translation efficiency, localization, and immune evasion. Cap-specific modifications such as Cap0, Cap1, and Cap2 were also described, highlighting their role in transcript stability and innate immune regulation. Advances in nanopore sequencing have enabled direct detection of RNA modifications and offer promise for eRNA (environmental RNA) surveys. The potential for nanopore sequencing of many other of the 335 known RNA modifications in the MODOMICS database using existing nanopore technologies is also discussed. Conclusions: mRNA modifications represent a critical, yet incompletely mapped, layer of gene regulation. Continued research—especially using nanopore and machine learning technologies—will help uncover their full biological significance. Exploration of eRNA and identifying new mRNA modifications will redefine our understanding of RNA biology. Full article

Introduction: Hypoxic cancers are radioresistant, but biomarkers based on expression of multiple genes can identify patients who will benefit from hypoxia modification. Most studies identifying relevant genes exposed cells in culture to 1% oxygen, which activates hypoxia-inducible factor (HIF). However, oxygen concentrations in hypoxic tumours are heterogeneous ranging from <0.1%. As lower oxygen levels would likely affect transcriptional responses, we aimed to investigate how gene selection at different oxygen levels affects the genes identified and their prognostic capability. Methods: Four MIBC (J82, T24, UMUC3, HT1376) and two non-MIBC (RT4, RT112) bladder cancer cell lines were exposed to varying oxygen levels (20%, 1%, 0.2% and 0.1% O₂) for 24 h and were then harvested and frozen. RNA was extracted and transcriptomes analysed using Clariom S microarrays. Differences in gene expression were investigated. Prognostic and predictive significance of a published 24-gene signature was compared with one generated from genes identified at lower oxygen levels. Results: The number of upregulated genes increased with decreasing O₂ level. The number of biological pathways involved also increased. Differences between cell lines dominated those due to hypoxia. Some genes were commonly upregulated in MIBC and NMIBC cells and others increased exclusively in either MIBC or NMIBC cells. The median expression of a published 24-gene bladder cancer hypoxia-associated signature increased with decreasing oxygen levels. Seventy-seven genes were upregulated in at least three cell lines by exposure to 0.1% O₂. The median expression of the 77 genes was of borderline prognostic significance in the bladder cancer cohort in the TCGA (The Cancer Genome Atlas). Five of the seventy-seven genes upregulated by hypoxia were present in the twenty-four-gene bladder hypoxia signature. The median expression of the 5 genes demonstrated identical prognostication to the 24-gene signature but failed to predict benefit from hypoxia modification. Conclusions: The number of genes upregulated by exposure of bladder cancer cells to hypoxia increases as O₂ level is decreased from 1% to 0.2% to 0.1%. Differential upregulation of gene expression by MIBC and NMIBC cells and the associated biological pathways may be useful in understanding the genetics of bladder cancer invasiveness. Based on a search of the literature, this is the first study that assessed the expression of genes in bladder cancer using three hypoxic concentration levels to identify biomarkers for disease progression and prognosis among differentially expressed bladder cancer genes. Full article