Ovarian cancer (OV) has the highest mortality rate among gynecological malignancies, with limited improvement in survival despite emerging treatments, underscoring an urgent need for novel diagnostic and therapeutic targets. Alternative splicing (AS) plays critical roles in OV progression, and long non-coding RNAs (lncRNAs) have recently been implicated as splicing regulators in tumor development. However, the landscape of lncRNA-mediated splicing dysregulation in OV remains unexplored. Here, we performed a genome-wide analysis integrating 207 differentially expressed lncRNAs and 1201 abnormal AS events from OV transcriptomes, identifying 2545 co-expression pairs. By constructing multi-layer regulatory networks incorporating splicing factors, transcription factors, and microRNAs, and applying a restart random walk algorithm seeded with oncogenes, we prioritized 29 hub splicing-regulatory lncRNAs, of which 15 are significantly associated with OV survival. This study provides novel lncRNA biomarkers and mechanistic insights into splicing dysregulation in OV.
Hepatocellular carcinoma (HCC) is a malignant neoplasm characterized by high incidence and mortality rates globally. Its pathogenesis and progression are intricate and multifaceted, necessitating comprehensive analysis and elucidation. Recent studies have demonstrated that non-coding RNAs (such as long non-coding RNAs, circular RNAs, and microRNAs) and alternative splicing, which are central to post-transcriptional regulation, engage in extensive regulatory interactions. These interactions form a complex regulatory network that significantly influences the malignant properties such as stemness, proliferation, invasion, metastasis, metabolic reprogramming, tumor microenvironment, and drug sensitivity in liver cancer cells. This review systematically explores the molecular mechanisms underlying the interactions between non-coding RNAs and alternative splicing events, highlighting the role of this regulatory network in modulating the expression of oncogenes and tumor suppressor genes in HCC. Additionally, this review investigates the prospective application of pivotal molecules within this regulatory network as novel diagnostic biomarkers and therapeutic targets. It also analyzes the challenges and obstacles encountered in the clinical translation process, thereby providing new insights for research on the precision diagnosis and treatment of HCC.
Cystic Fibrosis (CF) is a genetic disease characterized by chronic pulmonary inflammation and infection, principally with Pseudomonas aeruginosa. P. aeruginosa can exhibit resistance to innate immune effectors and antibiotics by expressing virulence factors and forming antibiotic-resistant biofilms, which facilitate chronic infection in immunocompromised hosts. Therefore, new antimicrobials are required. MicroRNAs are mammalian short non-coding RNAs that negatively regulate protein expression. MiR-17-5p, an inhibitor of CXCL8/IL-8, can decrease neutrophil abundance in the CF lung. Here we investigate whether miR-17-5p has anti-P. aeruginosa properties. The sequences of the full-length miRNA and the miR-17-5p isoform miR.17.P4d_5p were tested for their ability to bind to RNA transcripts encoded by P. aeruginosa PAO1 (NC_002516) using the bioinformatics tools RocketmiR and IntaRNA. A miR-17-5p DNA tetrahedron (Td-miR.17.P4d_5p, Size = 118-180 nm) was tested for its delivery into CF bronchial epithelial cells and ability to inhibit IL-8 gene and protein expression, and its effects on P. aeruginosa growth, antimicrobial resistance, and biofilm formation. Successful delivery into CFBE41o- and 16HBE14o- cells inhibited IL-8 expression induced by Pseudomonas-conditioned medium (PAO1, Mucoid strains 1 and 2 p < 0.00001; PA14 p < 0.0001). Delivery into PAO1 and PA14 inhibited growth and biofilm formation while significantly enhancing their sensitivity to the antibiotic cefotaxime. Td-miR.17.P4d_5p also significantly inhibited biofilm formation in two clinical mucoid P. aeruginosa strains. qPCR and EMSA were used to investigate the mechanism of action of miR.17.P4d_5p. The data showed that miR.17.P4d_5p could inhibit expression of kynU (p < 0.00001), a tryptophan metabolism pathway molecule related to PAO1 growth, and the biofilm formation-related molecules pilL, fimX, ppkA and pslA (all p < 0.00001) in P. aeruginosa PAO1. The combined anti-IL-8 and anti-P. aeruginosa properties of miR.17.P4d_5p suggest its potential usefulness as a dual anti-infective and anti-inflammatory therapeutic strategy for CF.
Pulmonary arterial hypertension (PAH) is a progressive vasculopathy characterized by pathological vascular remodeling, in which pulmonary artery smooth muscle cells (PASMCs) undergo phenotypic switching from a contractile to a synthetic state, driving excessive proliferation and migration. Here, we report that miR-199a-3p is significantly downregulated in both hypoxia/SU5416-induced PAH rat models and PDGF-BB-stimulated human PASMCs. Mechanistically, PDGF-BB stimulation induces the phosphorylation of STAT3, which directly binds to the TTCCCGGAA motif within the promoter of miR-199a-3p. This binding transcriptionally represses miR-199a-3p. Functional analyses demonstrated that miR-199a-3p overexpression maintains the PASMC contractile phenotype (upregulating MYH11 and SM22α) and suppresses proliferation and migration. Conversely, miR-199a-3p inhibition promotes synthetic phenotypic switching and activates the ERK/AKT signaling pathway. Furthermore, we identified YAP1 as a novel direct target of miR-199a-3p, linking miRNA downregulation to downstream proliferative signaling. Collectively, these findings establish a PDGF-BB/STAT3/miR-199a-3p/YAP1 regulatory axis that drives pathological PASMC phenotypic switching. This axis represents a promising therapeutic target for mitigating pulmonary vascular remodeling in PAH.
Acute myeloid leukemia (AML) is a malignant hematologic disease with poor prognosis, and improved understanding of its biology is critical for patient outcomes. While protein-coding genes in AML are well characterized, the role of long non-coding RNAs (lncRNAs) remains largely unexplored. Here, we investigated how lncRNAs contribute to AML biology and treatment resistance. Three high-throughput lncRNA-CRISPR-interference (CRISPRi) screens were performed in the AML cell line MOLM-13, targeting 7996 lncRNAs expressed in hematopoietic cells, with knockdowns directed to transcription start sites defined through cap analysis of gene expression (CAGE) sequencing. Effects on proliferation, differentiation, and response to the Bcl-2 inhibitor venetoclax were assessed. In total, 58, 4, and 23 lncRNAs were found to affect proliferation, differentiation, and venetoclax sensitivity, respectively. Three proliferation-associated lncRNAs (MIR17HG, CATG00000106133.1, and CATG00000056792.1) and one venetoclax-associated lncRNA (AC009299.3) were further investigated. CATG00000106133.1 was enriched in de novo and cytogenetically normal AML and correlated with NPM1 and IDH2 mutations. Gene Ontology and Reactome analyses of RNA-seq from CATG00000106133.1 knockout cells revealed roles in cytokine signaling and immune pathways. AC009299.3, linked to venetoclax response, was associated with poor outcome, adverse risk, and increased age in AML patients. Collectively, this study identifies four lncRNAs implicated in key leukemogenic processes, highlighting their potential for understanding AML biology, prognosis, and therapeutic response.
Background:Pancreatic cancer (PC) endures as one of the most lethal malignancies, characterized by a dismal prognosis due to late-stage detection and limited therapeutic options. Circulating noncoding RNAs (ncRNAs) play significant roles in malignancy detection and prognosis. Thus, we evaluated the clinical value of serum long ncRNA MIR22HG and miR-10a-5p in PC cases, clarifying their relationship with downstream targets: β-catenin, C-myc, and E-cadherin. Methods:A case-control study was conducted involving 65 PC cases and 25 healthy controls, utilizing RT-qPCR to measure serum levels of MIR22HG, miR-10a-5p, β-catenin, C-myc, and ELISA to investigate E-cadherin. Besides, CA19.9 and CEA were assessed employing the chemiluminescence approach. Results:Our findings revealed significant downregulation of MIR22HG, β-catenin, and C-myc, alongside upregulation of miR-10a-5p and E-cadherin in the serum of PC cases compared to controls. MIR22HG and miR-10a-5p demonstrated high diagnostic accuracy for PC with AUCs of 0.95 and 0.97, respectively. The diagnostic efficiency of PC traditional markers, CA19.9 or CEA, was enhanced by integrating with MIR22HG and miR-10a-5p. Moreover, low MIR22HG and β-catenin serum levels were notably associated with advanced lymphatic and distant metastases, distinguishing between metastatic and curative PC cases with AUCs of 0.73 and 0.82, respectively. MIR22HG was notably positively correlated with β-catenin and C-myc, whereas it was negatively correlated with miR-10a-5p. Conclusion:This study highlights the clinical potential of serum MIR22HG and miR-10a-5p as novel diagnostic biomarkers and identifies MIR22HG and β-catenin as prognostic indicators, thereby paving the way for improved PC management.
Prostate cancer (PCa) remains one of the most prevalent and lethal malignancies in men worldwide. The pronounced heterogeneity and therapeutic resistance of PCa underscore the critical need to decipher its RNA regulatory network for advancing precision medicine. This review systematically outlines the cutting-edge applications of CRISPR technology in studying the RNA regulatory network of PCa. We highlight the CRISPR systems as a powerful tool for functional decoding, target screening, ultrasensitive diagnostics, and precision intervention, emphasizing their pivotal role in elucidating the functional mechanisms of mRNA, miRNA, circRNA, lncRNA, eRNA, and m6A modification. Furthermore, this review synthesizes how these insights not only reveal the core functions of diverse RNA molecules in PCa initiation, progression, drug resistance, and metastasis but also propel the innovation of novel therapeutic strategies, including mRNA vaccines, Cas13-mediated RNA editing, and targeted delivery systems. Finally, we discuss future directions and challenges in developing personalized CRISPR-RNA therapeutics integrated with multi-omics technologies, aiming to provide a theoretical foundation and technical framework for precision medicine in PCa.
Ocular neovascular diseases (ONDs) are a leading cause of global blindness. While current anti-vascular endothelial growth factor (VEGF) treatments have revolutionized management, their efficacy is constrained by issues such as non-response, resistance development, and the burden of repeated intravitreal injections. Recent studies have highlighted the growing importance of transfer RNA-derived small RNAs (tsRNAs) in regulating pathological angiogenesis. This review provides a systematic analysis of tsRNAs, encompassing their origins, classification, and mechanisms of action, followed by an exploration of their implications in OND. Targeting tsRNAs may offer a novel multi-level regulatory strategy to overcome the limitations of current anti-VEGF therapies.
Thermostable RNA motifs have been shown to be a unique material for building nanoparticles for many applications (Guo lab, Nature Nanotechnology, 2020 PMID: 21102465; 2021 PMID: 21909084). Here, we report the discovery of a G-rich ultra-stable human ncRNA G-quadruplex that binds ATP with a strong potential to become a drug-carrying nanoparticle. Motion is a key feature of living systems, which can be achieved with ATPase biomotors. Humans produce, metabolize, and consume ATP per day in an amount equivalent to their body weight. Due to the abundance of noncoding RNA (ncRNA) discovered in the human body, it is expected that many short or long noncoding RNAs will be involved in ATP binding and hydrolysis. This is based on the fact that, although all currently reported ATPases are proteins, only 1.5% of the human DNA genome codes for proteins, while the remaining 98.5% codes for ncRNAs that play crucial roles in regulating life functions. We discovered an endogenous human ncRNA G-quadruplex that binds ATP. This ATP-binding RNA was discovered via in vitro screening of endogenous ncRNAs extracted from human cells. This ATP-binding ncRNA, which was found to be G-quadruplex-forming, was characterized by ATP column binding and circular dichroism. The tightly folded, compact RNA nanoparticles will provide a new class of functional nanomaterials as both targets and carriers for drug conjugation and therapeutic delivery.
Spermatogenesis is a complex differentiation process requiring precise spatiotemporal gene regulation, yet the functions of most testis-enriched long noncoding RNAs (lncRNAs) remain elusive. Here, we identify 1700008K24Rik as a pachytene-specific lncRNA that is essential for mouse spermatogenesis. Reanalysis of single-cell RNA-seq reveals that 1700008K24Rik expression is minimal in spermatogonia and preleptotene cells, sharply increases during the pachytene stage, and declines after meiosis, precisely coincides with the wave of pachytene piRNA production. In vivo knockdown of 1700008K24Rik in mouse testes via AAV9-shRNA severely disrupts spermatogenesis, causing a reduction in testis size, seminiferous epithelium thickness, and epididymal sperm count, suggesting its physiological necessity. Mechanistically, we demonstrate that 1700008K24Rik functions as a bona fide piRNA precursor: it harbors numerous piRNA sequences, and its overexpression in GC-2 spd(ts) cells specifically upregulates corresponding overlapping piRNAs. This processing relies on the core piRNA machinery, and co-overexpression of A-MYB, together with MOV10L1 or MIWI, promotes piRNA production. Notably, this piRNA precursor function is evolutionarily conserved, as the human homolog TDRG1, which is linked to asthenozoospermia, also generates piRNAs when expressed in GC-2 spd(ts) cells. Transcriptomic analysis following 1700008K24Rik overexpression in GC-2 spd(ts) cells reveals dysregulation of genes involved in metabolism and signaling, with several spermatogenesis-related genes (e.g., Msh5, Stard6) predicted as direct targets of 1700008K24Rik-derived piRNAs. Our study identifies 1700008K24Rik as a pachytene-specific lncRNA essential for male fertility and demonstrates that it functions as a conserved piRNA precursor. These findings provide mechanistic insight into how an individual lncRNA contributes to the piRNA pathway and suggest that it may operate through dual mechanisms in mammalian spermatogenesis.
tRNA-derived small RNAs (tsRNAs) are a class of noncoding RNAs (ncRNAs) generated via the site-specific enzymatic cleavage of mature or precursor tRNAs. They are ubiquitously expressed across diverse species and are detectable in numerous cell lineages and extracellular fluids like blood and serum. They regulate gene expression at multiple levels and are functionally implicated in pivotal biological processes, including cell cycle regulation and immune response modulation. Accumulating evidence has implicated tsRNAs in both the initiation and development of cardiovascular diseases (CVDs). This article provides an overview of the classification and biological functions of tsRNAs before delving into their specific roles and mechanisms in cardiovascular pathophysiology. It aims to offer perspectives on novel therapeutic strategies, as well as the early diagnosis and prognosis assessment of CVDs.
Lung adenocarcinoma (LUAD) progression is strongly shaped by tumor-associated macrophages (TAMs), yet the post-transcriptional mechanisms that sustain matrix-remodeling TAM states remain incompletely understood. Here, circRNA profiling of LUAD TAMs versus normal tissue-resident macrophages identified circSMAD4 (hsa_circ_0047713) as a consistently TAM-enriched circRNA associated with advanced clinicopathological features and unfavorable survival. circSMAD4 exhibited canonical circular properties, including a validated back-splice junction, RNase R resistance, and enhanced transcript stability. Functionally, circSMAD4 knockdown in human and murine macrophages attenuated tumor education, shifted macrophages away from an M2-like phenotype, and weakened their ability to promote LUAD-cell proliferation, invasion, and EMT-like changes in co-culture. In syngeneic orthotopic lung and experimental metastasis models, circSMAD4-depleted macrophages restrained tumor growth and reduced metastatic burden. Mechanistically, cytoplasmic circSMAD4 acted as a ceRNA to sequester miR-562 and relieve repression of COL4A1. In parallel, circSMAD4 formed a specific ribonucleoprotein complex with the m6A reader IGF2BP2, facilitating IGF2BP2 association with COL4A1, ACTA2, and SPI1 transcripts and enhancing their m6A-dependent stability. Together, these dual branches converge on a matrix-remodeling output, positioning circSMAD4 as a post-transcriptional hub that reinforces protumor TAM programs in LUAD and a potential target for microenvironment-directed therapy.
Circular RNAs (circRNAs) are covalently closed, single-stranded RNA molecules generated from both nuclear and mitochondrial genomes. Several nuclear-encoded circRNAs have been reported to be conserved in sequence and function across animals. However, the evolutionary conservation and physiological significance of mitochondria-encoded circRNAs (mecciRNAs) remain largely unexplored. Here, by analyzing mitochondrial RNA sequencing data from human and mouse cells, we identify a conserved mecciRNA derived from the MT-ATP6 locus, termed mecciATP6. We show that mecciATP6 modulates mitochondrial homeostasis by binding and regulating the protein abundance of an evolutionarily conserved RNA-binding protein (RBP) HNRNPA3. Our data provide a conceptual framework for defining mecciRNA conservation across mammals and uncover a conserved mecciRNA-protein regulatory mechanism linked to mitochondrial homeostasis.
Long non-coding RNAs (lncRNAs) have emerged as critical regulators of gene expression and play essential roles in a wide range of biological processes and human diseases, particularly cancer. DSCAM antisense RNA 1 (DSCAM-AS1) is a recently identified lncRNA transcribed from the antisense strand of the human DSCAM (Down Syndrome Cell Adhesion Molecule) locus. Accumulating evidence demonstrates that DSCAM-AS1 is aberrantly overexpressed in multiple cancer types and is closely associated with tumor proliferation, invasion, and metastasis, etc. Mechanistically, DSCAM-AS1 exerts oncogenic functions through diverse regulatory modes, including transcriptional positive feedback loops, competing endogenous RNA (ceRNA) activity that sequesters tumor-suppressive microRNAs, modulation of alternative splicing and 3′ end usage via interaction with hnRNPL, and epigenetic regulation of cancer-related gene expression. Moreover, the cancer- and isoform-specific expression pattern of DSCAM-AS1 highlights its potential utility as a diagnostic biomarker and a therapeutic target. In this review, we summarize the discovery, molecular characteristics, disease associations, and regulatory mechanisms of DSCAM-AS1, and discuss its emerging clinical relevance in cancer diagnosis, prognosis, and targeted therapy.
Background:Diabetes mellitus is a major modifiable risk factor for atherosclerotic cardiovascular disease and pathological vascular remodeling. During chronic hyperglycemia, exosomes serve as essential nanocarriers that coordinate intercellular communication and induce structural and functional alterations in the vascular wall. Perivascular pre-adipocytes (PVPACs) exhibit high exosome secretory activity, while adventitial fibroblasts (AFs) are key effector cells in vascular remodeling. Despite their anatomical proximity, the potential bidirectional crosstalk between PVPAC-derived exosomes and AFs, and its roles for vascular remodeling, remains largely unexplored. Methods:A co-culture system of PVPACs and AFs, along with a mouse model of perivascular proliferation, was established under sustained hyperglycemic conditions. Exosomes were isolated via sequential ultracentrifugation and characterized based on morphology, size distribution, and exosomal markers. High-throughput RNA microarray was employed to profile PVPAC-derived exosomal RNAs, with qRT-PCR and in situ hybridization used to validate the expression of circEif3c, miR-96-5p, PHF20L1, and MEOX2. Mechanistic studies integrated bioinformatic predictions, CRISPR-Cas9 editing, with bio-functional assays, including RNA pull-down, RIP, dual-luciferase reporter, CO-IP, and protein interaction analyses, to elucidate the circEif3c/miR-96-5p/PHF20L1/MEOX2 axis. In vitro and in vivo rescue experiments evaluated the role of exosomal circEif3c in AF proliferation, migration, apoptosis, and vascular remodeling. Results:PVPAC-derived exosomes were enriched with circEif3c, which acted as a competitive endogenous RNA by sequestering miR-96-5p, thus alleviating its suppression of PHF20L1 and inhibiting MEOX2 signaling. This axis enhanced AF proliferation and migration, reduced apoptosis, and exacerbated vascular remodeling. Conversely, inhibition of exosomal circEif3c or overexpression of MEOX2 attenuated AF activation, promoted apoptosis, and markedly improved vascular remodeling in diabetic mice. Conclusion:Our findings establish the PVPAC-derived exosomal circEif3c/miR-96-5p/PHF20L1/MEOX2 axis as a critical driver of hyperglycemia-induced vascular remodeling. Targeting this pathway presents a promising therapeutic strategy to combat diabetes-associated vascular pathology and its complications.
Background:Cerebral cavernous malformations (CCMs) are vascular anomalies prone to hemorrhage, leading to neurological deficits and reduced quality of life. Current therapies are limited, and molecular mechanisms underlying vascular instability remain incompletely understood. MicroRNAs have emerged as key regulators of vascular integrity. This study investigates the role of microRNA-21-3p (miR-21-3p) in modulating oxidative stress and angiogenesis in CCM. Methods:Expression of miR-21-3p, NADPH oxidase 4 (NOX4), and vascular endothelial growth factor A (VEGFA) was assessed in endothelial cells and pericytes from CCM lesions of 20 sporadic patients using fluorescence in situ hybridization. Functional assays of proliferation, permeability, reactive oxygen species (ROS), migration, and tubule formation were performed in human brain microvascular endothelial cells (BMECs) and pericytes with CCM2 gene depletion, following miR-21-3p mimic or inhibitor intervention. In vivo effects on cerebral hemorrhage, vascular permeability, dilation, and angiogenesis were evaluated in ccm2-knockdown zebrafish. Results:CCM lesions exhibited decreased miR-21-3p and increased NOX4 and VEGFA compared to controls, correlating with hemorrhage. In vitro, miR-21-3p mimics suppressed proliferation, permeability, ROS generation, and angiogenic activity by directly targeting NOX4 and VEGFA. In vivo, miR-21-3p supplementation reduced cerebral hemorrhage, vascular leakage, dilation, and sprouting angiogenesis in zebrafish with ccm2 knockdown. Conclusion:MiR-21-3p regulates vascular integrity in CCM by modulating NOX4-mediated oxidative stress and VEGFA-driven angiogenesis. Loss of miR-21-3p contributes to hemorrhage, while its restoration stabilizes vascular function. This study identifies miR-21-3p as a potential therapeutic target for CCM, bridging endothelial and pericyte biology with translational potential to reduce cerebral hemorrhage.
Background: Vulnerable carotid atherosclerotic plaques are prone to cap rupture and thrombosis, yet definitive assessment still relies on postoperative histology. We investigated whether circulating circular RNAs (circRNAs) in peripheral blood mononuclear cells (PBMCs) can identify plaque vulnerability preoperatively. Method: In patients undergoing carotid endarterectomy, plaques were classified as vulnerable or stable, and PBMC expression of candidate circRNAs (circVIRMA, circGRN, circANRIL and CDR1as) and paired linear transcripts was quantified by RT-qPCR. A composite in-plaque_SCORE (IL-1β, IL-6, IL-10, PPARγ mRNAs) characterized intraplaque inflammation. We derived two PBMC metrics: circRNA_SCORE (mean expression of deregulated circRNAs) and circ/linear mRNA_SCORE (mean of circ/linear mRNA expression ratios) and evaluated diagnostic performance by Receiver Operating Characteristic curve (ROC) analysis and logistic regression. Results: circVIRMA and circGRN were modestly increased in PBMCs from patients with vulnerable plaques, whereas linear host genes were unchanged. CDR1as was markedly upregulated and showed the strongest discrimination among the other circRNAs, similarly to the circRNA_and circRNA/linear mRNA ratio_SCOREs. Indeed, circRNA_SCORE correlated positively with the intraplaque inflammatory in-plaque_SCORE, linking systemic signatures to local plaque biology. In plaque tissue, CDR1 mRNA was reduced while CDR1as was relatively preserved, yielding a higher CDR1as/CDR1 mRNA ratio in vulnerable lesions. Conclusions: PBMC circRNAs—particularly CDR1as—show promise as noninvasive biomarkers of carotid plaque vulnerability and reflect plaque inflammatory status. Validation in independent cohorts and integration with imaging could enable improved preoperative risk stratification.
Nuclear microRNAs represent a novel class of non-canonical miRNAs localized within the nucleus, distinguished from classical cytoplasmic miRNAs by their unique ability to activate gene transcription. Classical miRNAs, approximately 22 nucleotides in length, regulate target mRNA stability or translational efficiency, primarily leading to translation inhibition or mRNA degradation. In contrast, nuclear microRNAs, measuring 18–22 nucleotides, do not rely on Dicer processing and are directly cleaved from precursor miRNAs by Drosha. Their nuclear localization and regulation of gene transcription contrast sharply with the suppressive role of classical miRNAs. Nuclear microRNAs are transcribed and modified within the nucleus via RNA polymerase II, undergoing processing similar to conventional miRNAs but diverging in their final nuclear localization and functional mechanisms. They interact with key regulatory elements such as promoters, enhancers, or gene bodies, modulating gene expression at the transcriptional level. This interaction can occur through RNA-RNA scaffolding, RNA-DNA hybrid formation, or RNA-DNA triplex formation, influencing chromatin structure and transcription factor accessibility. Nuclear microRNAs demonstrate diverse regulatory functions, acting as enhancer triggers, promoter regulators, and transcriptional amplifiers. They recruit transcription factors or alter chromatin's epigenetic state to promote transcription, impacting cellular processes such as hematopoiesis, differentiation, and apoptosis. In particular, nuclear microRNAs have been implicated in cancer progression and therapeutic responses, with the potential to orchestrate oncogene networks and tumor-suppressive pathways. Despite their promising therapeutic potential, clinical translation of nuclear microRNAs faces challenges such as delivery precision, immunogenicity, regulatory complexity, and ethical governance. Advancing nuclear delivery systems and mechanistic studies are essential to overcome these limitations and harness the full potential of nuclear microRNAs in gene regulation therapeutics. As research progresses, nuclear microRNAs may revolutionize RNA therapeutics by enabling transcriptional-level disease intervention.
DICER1 is a key processing enzyme required for the generation of mature and active miRNAs. Mutations that diminish DICER1 function result in widespread changes in miRNA levels, resulting in changes in the transcriptome and cellular phenotypes. Previously, we have found that mutations within the 3'UTR of the Dicer1 mRNA diminish DICER1 protein levels and miRNA production. Triple negative breast cancer cells that contain these mutations have slower growth and migration and diminished tumorigenic potential. By comparing the transcriptome and miRNA profile of these cells, we find that miR30d-5p are significantly reduced in DICER1 mutant cells. This reduction in miR30d-5p results in increased mRNA stability and protein levels of the miR30d-5p target, SNAIL, a transcription factor that promotes the transcription of genes required for mesenchymal cell fates. We show that elevated SNAIL protein levels induce the upregulation of SNAIL target genes that can be partially rescued by the addition of miR30d-5p. Our results highlight the key role for DICER1 and miRNA levels in modulating cell fate in breast cancer.
