Search PubMedSearch

SEARCH · Search PubMed

Results for “tumor suppression”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

264 records · Page 2Linked to original sources

Alternative End Joining Dependency Imposed by miR-21-5p Defines Radiation Resistance and a Targetable Vulnerability in Oral Squamous Cell Carcinoma.

PURPOSE: Clinical control of oral squamous cell carcinoma (OSCC) is constrained by heterogeneous radiosensitivity driven by divergent DNA damage response programs. The architecture and functional contribution of alternative end joining (Alt-EJ), an error-prone DNA double-strand break (DSB) repair pathway frequently upregulated in cancer, to radiation resistance remains poorly defined. METHODS AND MATERIALS: We profiled microRNAs in radioresistant OSCC clones and performed multiomic integration across an institutional OSCC cohort, an external OSCC cohort from the Gene Expression Omnibus, The Cancer Genome Atlas pan-cancer tumors, and cell lines characterized by Sanger Genomics of Drug Sensitivity in Cancer to infer DNA damage response characteristics, genomic scar features, drug sensitivity, and radiation therapy outcomes. DSB repair capacity and pathway usage were validated using functional assays, including Alt-EJ reporters and droplet digital PCR quantification of microhomology-mediated repair events. Core Alt-EJ effectors such as PARP1 and POLQ were perturbed genetically and pharmacologically. Therapeutic efficacy of PARP or POLQ inhibition with or without irradiation was tested in a syngeneic OSCC model, followed by bulk tumor transcriptomics to assess pathway engagement. RESULTS: Upregulation of miR-21-5p was not only selectively detected in radioresistant OSCC, but also modulated radiosensitivity in vitro and in vivo, and was associated with inferior postradiation therapy survival. A calibrated miR-21-5p target-gene signature tracked Alt-EJ activity across patient and mouse tumors and cancer cell lines, correlated with microhomology-mediated indels and broader genomic scarring, and predicted sensitivity to clinically available PARP inhibitors. Functionally, enforced miR-21-5p expression increased Alt-EJ usage and accelerated DSB repair, whereas inhibition or depletion of key Alt-EJ effectors reduced repair efficiency and restored radiosensitivity. In vivo, Alt-EJ targeting with PARP or POLQ inhibitor abrogated miR-21-5p-driven radiation resistance; transcriptomic profiling supported suppression of Alt-EJ programs as the operative mechanism. CONCLUSIONS: These findings establish a mechanistic link between miR-21-5p activity and Alt-EJ dependence, provide a clinically deployable signature to identify Alt-EJ-dependent OSCC, and support rational combinations of Alt-EJ targeting agents with radiation therapy to overcome treatment failure and advance precision radiation oncology.

MicroRNAs

Biomarker Analysis from Patients with Metastatic PDAC Treated with TGFβ Antibody NIS793 plus Abraxane + Gemcitabine versus Abraxane + Gemcitabine Alone in a Phase II, Open-Label, Randomized Study.

PURPOSE: Transforming growth factor β (TGFβ) plays a dual role in cancer, acting as a tumor suppressor early in the disease but promoting progression and immune evasion when dysregulated. In pancreatic ductal adenocarcinoma (PDAC), TGFβ-driven desmoplasia fosters chemoresistance and immunosuppression, limiting therapeutic efficacy. NIS793, a fully human mAb targeting TGFβ, demonstrated antifibrotic and immunomodulatory activity in preclinical models and early-phase trials. PATIENTS AND METHODS: We conducted a randomized, open-label, phase II study in treatment-naïve patients with metastatic PDAC (mPDAC) to evaluate NIS793 ± spartalizumab (anti-PD-1) combined with nab-paclitaxel (or Abraxane)/gemcitabine (ABRA/GEM) versus ABRA/GEM alone. The primary endpoint was progression-free survival (PFS); secondary endpoints included overall survival (OS), safety, pharmacokinetics, and biomarker analyses. Exploratory assessments included paired tumor RNA sequencing, cell-free DNA profiling, and plasma proteomics. RESULTS: NIS793 demonstrated target engagement and suppression of TGFβ signaling, confirmed by transcriptomic and proteomic analyses. Stromal remodeling was evident, with significant downregulation of cancer-associated fibroblast markers (Acta2, Fap) and collagen-related signatures. Despite proof of mechanism, clinical efficacy was not observed: Median PFS and OS were comparable or numerically worse in the NIS793 arm versus control (HR for OS in NIS793 + ABRA/GEM vs. ABRA/GEM: 1.32; 95% confidence interval, 0.84-2.07). The safety profile was manageable, with no unexpected toxicities. Biomarker data revealed increased expression of neutrophil-related genes after treatment, suggesting potential induction of tumor-promoting inflammation. CONCLUSIONS: NIS793 effectively inhibited TGFβ signaling and led to stromal remodeling but failed to improve outcomes in mPDAC. These findings highlight the complexity of TGFβ biology and caution against its blockade in combination with chemotherapy for PDAC. Future strategies should consider context-dependent effects of TGFβ inhibition.

Humans

Lactylation-related immune-metabolic dysregulation defines prognostic and therapeutic stratification in lung adenocarcinoma.

BACKGROUND: Lactylation links lactate metabolism with inflammatory signaling and immune regulation in tumors. However, its cellular distribution and translational value in lung adenocarcinoma (LUAD) remain unclear. METHODS: Single-cell RNA-sequencing datasets GSE189357 and GSE171145 were integrated to characterize lactylation-related activity, intercellular communication, and malignant epithelial cell states in LUAD. Single-cell-derived lactylation-related differentially expressed genes were mapped to TCGA-LUAD and multiple GEO cohorts. Univariate Cox regression and machine learning algorithms were used to construct a lactylation-related prognostic signature (LRPS). The associations of LRPS with prognosis, immunotherapy response, drug sensitivity, genomic alterations, immune infiltration, and inflammation- and metabolism-related pathways were evaluated. KRT7 was further validated using virtual knockout analysis, spatial transcriptomics, and in vitro and in vivo experiments. RESULTS: lactylation-related transcriptional activity showed heterogeneous distribution across LUAD cell populations and was associated with altered cell-cell communication. In malignant epithelial cells, LRTS-high and LRTS-low states exhibited distinct metabolic, inflammatory, and tumor-related pathway activities. LRPS showed stable prognostic performance in TCGA-LUAD and multiple GEO cohorts and remained an independent prognostic factor. Low LRPS was associated with greater potential benefit from immunotherapy, whereas different LRPS groups displayed distinct drug sensitivity, genomic alteration, and immune microenvironment patterns. KRT7 was highly expressed in LUAD and associated with poor prognosis. KRT7 knockdown suppressed LUAD cell proliferation, migration, invasion, colony formation, and tumor growth in vivo. CONCLUSIONS: This study identifies lactylation-related immune-metabolic dysregulation as a clinically relevant feature of LUAD and develops a single-cell-guided LRPS for prognosis and therapeutic stratification. KRT7 emerged as an LRPS-related functional candidate with experimentally supported roles in malignant LUAD phenotypes.

Immunotherapy

A Multi-omics Regulated Cell Death Framework Defines Immune Phenotypes and Guides Precision Therapy in Colorectal Cancer.

Colorectal cancer (CRC) is molecularly and immunologically heterogeneous, contributing to variable treatment response. Because regulated cell death (RCD) intersects with tumor metabolism, immune regulation, and therapeutic susceptibility, we built an RCD-centered framework for CRC stratification. Multi-cohort transcriptomic data were used to infer RCD subtypes with non-negative matrix factorization (NMF) and non-negative least squares (NNLS). Genomic, bulk RNA-seq, single-cell RNA-seq, and spatial transcriptomic datasets were integrated to characterize subtype-associated biology. Machine-learning models were developed for immunotherapy response and survival-risk estimation. Candidate compounds were screened by GDSC2-based drug-sensitivity modeling and molecular docking, and FSTL3 was functionally assessed in vitro. The framework separated CRC samples into two RCD-related phenotypes resembling immune-hot and immune-cold states. RCD1 showed immune activation and higher mutational burden, whereas RCD2 showed immune-suppressed features, intratumoral heterogeneity, and aggressive biology. RCD-associated signatures showed potential for predicting immunotherapy response and survival risk. Dasatinib was prioritized for immune-cold, high-risk tumors, with preliminary evidence supporting its activity in CRC cells, while functional assays suggested a role for FSTL3 in growth, invasion, epithelial-mesenchymal transition, and apoptosis regulation. These findings suggest that RCD-based multi-omics analysis may refine CRC stratification and help generate therapeutic hypotheses.

Colorectal cancer

The role of adjunctive aqueous suppressants for anti-vascular endothelial growth factor therapy: A systematic review.

Our goal is to determine whether adjunctive aqueous suppressants (topical β-blockers, carbonic anhydrase inhibitors, or oral acetazolamide) enhance outcomes of anti-vascular endothelial growth factor (anti-VEGF) therapy for diabetic macular edema (DME), retinal vein occlusion (RVO), and neovascular age-related macular degeneration (nAMD), focusing on retinal thickness, visual acuity, injection burden, intraocular pressure (IOP), and safety. DME, RVO, and nAMD are leading causes of vision loss treated with repeated intravitreal injections, yet many eyes show persistent fluid. Aqueous suppressants are inexpensive and widely available, with potential to prolong intravitreal drug residence and improve outcomes, but their clinical value remains uncertain. Following a registered protocol, we searched 4 databases (January, 2000 toMay, 2025) for randomized and comparative studies evaluating adjunct aqueous suppressants with anti-VEGF therapy. Primary outcome was change in retinal thickness; secondary outcomes included visual acuity, injection burden, IOP, and adverse events. Risk of bias was assessed and findings synthesized narratively. Twelve studies (7 randomized trials; 495 eyes) met inclusion criteria. In DME, 3 of 4 trials showed greater thickness reduction with adjunctive dorzolamide (±timolol), although visual gains were inconsistent. In RVO, 1 trial suggested transient anatomical benefit, whereas oral acetazolamide showed no added effect. In nAMD, adjunctive dorzolamide-timolol reduced residual fluid in refractory cases without visual or treatment-sparing benefit. Topical therapy produced modest IOP reductions without serious adverse events. Adjunct aqueous suppressants may provide limited short-term anatomical benefit, particularly in DME and refractory nAMD, but consistent functional or durability effects are not found in this study. Larger, longer-term randomized studies are needed.

Humans

The effect of antiretroviral therapy adherence on viral load suppression rate among people living with HIV in Ethiopia: A systematic review and meta-analysis.

BACKGROUND: Antiretroviral therapy (ART) adherence is a key determinant of viral load suppression among people living with HIV (PLHIV). In Ethiopia, evidence on the magnitude of ART adherence and its effect on virological outcomes remains fragmented. This systematic review and meta-analysis aimed to estimate the pooled prevalence of ART adherence and viral load suppression, and to measure the association between adherence and viral suppression among PLHIV in Ethiopia. METHODS: This systematic review and meta-analysis used the PRISMA checklist for systematic reviews and meta-analyses. The review protocol has been registered onPROSPERO:(CRD420251125899). PubMed, ScienceDirect, Scopus, Epistemonikos, and Google Scholar were searched. The quality of included articles has been evaluated with a Newcastle-Ottawa Scale (NOS), adapted for observational studies. A random-effects model using restricted maximum likelihood (REML) with Knapp-Hartung adjustment was used to estimate pooled prevalence and odds ratio. Heterogeneity was assessed using I2, τ2, and Cochran's Q test. RESULTS: A total of 39 studies were included in the final analysis. The pooled prevalence of good ART adherence was 79.4% (95% CI: 74.8%-83.4%), while the pooled viral load suppression rate was 77.5% (95% CI: 72.5%-81.8%). The pooled odds ratio showed that good ART adherence was strongly associated with viral load suppression (OR = 6.30, 95% CI: 4.84-8.19). Substantial heterogeneity was observed across studies for both adherence and viral suppression outcomes (I2 > 90%). CONCLUSIONS: ART adherence and viral load suppression among PLHIV in Ethiopia are relatively high but remain below global targets. Good adherence was significantly associated with virologic suppression, highlighting adherence as a critical modifiable factor for achieving optimal treatment outcomes. Strengthening adherence support interventions is essential to improve virological success and advance progress toward HIV epidemic control.

Humans

Direct Initiation of Long-Acting Cabotegravir Plus Rilpivirine in People with HIV and Suboptimal Virologic Suppression: A Randomized Trial.

BACKGROUND: Long-acting injectable cabotegravir plus rilpivirine (LA CAB+RPV) is approved for virally suppressed people with human immunodeficiency virus (HIV), but evidence for its use in those with persistent viremia and adherence challenges remains limited. METHODS: We conducted a multicenter, open-label, randomized study involving oral antiretroviral therapy (ART)-experienced people with HIV who had been diagnosed with HIV for at least 12 months and a most recent HIV-1 RNA level of at least 200 copies per milliliter. Participants with resistance-associated mutations to CAB or RPV were excluded. Eligible participants were randomly assigned in a 1:1 ratio to receive immediate LA CAB+RPV or to continue standard oral therapy until Week 24 (delayed switch group). The primary endpoint was the proportion of participants with an HIV-1 RNA level of less than 200 copies per milliliter at Week 24. RESULTS: Of 61 randomized participants, 45 met eligibility criteria and were included in the analysis; 91% were male, and the median baseline HIV-1 RNA was 35,000 copies/mL. At Week 24, viral suppression was achieved in 88.0% (22/25) in the immediate LA group versus 55.0% (11/20) in the delayed switch group (relative risk for failure to achieve viral suppression, 0.27; 95% CI, 0.08-0.86; p = 0.026). The effect of LA CAB+RPV was sustained through Week 52. CONCLUSIONS: Among people with HIV and viremia associated with adherence challenges, immediate initiation of LA CAB+RPV resulted in higher rates of viral suppression than continued oral ART, supporting its use beyond populations with stable suppression.

HIV

Suppression of HIV-1 replication in CEM-A cell cultures by trans-splicing group I introns targeting PAS/PBS sequences and conditionally expressing ΔN-Bax.

Anti-HIV group I introns containing antisense guide sequences directed against the HIV-1 primer activation signal and primer-binding site (PAS/PBS) were designed and evaluated. Because PAS/PBS sequences are present in the viral RNA species examined, these RNAs can serve as trans-splicing substrates. The introns were active against both artificial target RNAs and viral RNA generated during infection. Cleavage and degradation of targeted viral RNA may have contributed to suppression, whereas inclusion of a 3' exon encoding the proapoptotic protein ΔN-Bax was associated with increased programmed cell death and may have augmented suppression of viral replication. In cultured CEM-A cells, transgene expression of these introns markedly suppressed HIV-1 replication, with p24 levels falling below the assay detection limit in selected clones. RESULTS: RT-PCR and sequence analysis detected splice products containing the expected PAS/PBS junctions. In the dual-luciferase assay, intron expression reduced normalized Gaussia luciferase signal by approximately 70% relative to the negative control. Qualitative Annexin V imaging and caspase-3 assays were consistent with infection-dependent apoptosis after ΔN-Bax splice-product formation. Transient expression of each intron in HEK293T cells followed by infection with VSV-G-pseudotyped HIV-1NL4-3 at an MOI of 2 reduced p24 levels by approximately 50% at 4 days post-infection. Construct 128L produced the strongest RT-PCR band under the tested conditions and was selected for subsequent experiments. A canonical splice product and a low-abundance noncanonical splice product were detected; both involved the intended HIV-derived target RNA, although transcriptome-wide off-target splicing was not assessed. Heterogeneous transformed HEK293T populations showed an approximately 2-log10 reduction in p24. In selected clonal HEK293T and CEM-A lines, p24 was below the assay detection limit at the measured endpoints, including up to 90 days after infection in some CEM-A clones. CONCLUSIONS: PAS/PBS-targeting group I introns suppressed HIV-1-associated p24 production in the tested cell-culture models. Linking the introns to a ΔN-Bax 3' exon was associated with infection-dependent apoptosis and may further limit viral replication and spread. The use of highly conserved, functionally constrained target sequences may reduce the likelihood of escape, but viral evolution and transcriptome-wide off-target effects were not assessed. This conditional death-upon-infection strategy warrants further evaluation in primary-cell and in vivo models.

Humans

Mitochondrial translocation of DNMT3L suppresses oxidative phosphorylation and restrains megakaryopoiesis.

DNMT3L, a catalytically inactive member of the DNA methyltransferase family, is identified here as a negative regulator of megakaryopoiesis. In K562 cells undergoing PMA-induced megakaryocytic differentiation, DNMT3L protein levels declined progressively, and shRNA-mediated depletion enhanced differentiation, whereas overexpression attenuated it. Consistent with these findings, Dnmt3l-knockout mice exhibited elevated peripheral blood platelet counts and expanded bone marrow megakaryocytes. Mechanistically, megakaryocytic differentiation triggered rapid mitochondrial translocation of DNMT3L within 6 h; mitochondrial DNMT3L suppressed oxidative phosphorylation (OXPHOS) capacity and ATP production and downregulated mitochondrial-encoded genes spanning Complex I, III, IV, and ATP synthase, without altering mitochondrial DNA copy number. This metabolic suppression was mediated through compartment-specific remodeling of DNMT3L-containing protein complexes: upon differentiation, DNMT3L selectively dissociated from DNMT1 and DNMT3B in mitochondria, relieving the repressive constraint on OXPHOS, whereas in the nucleus DNMT3L remained associated with DNMT3A, which concomitantly accumulated during differentiation. These findings reveal a previously unrecognized mechanism by which a catalytically inactive epigenetic co-regulator spatially redistributes to coordinate mitochondrial metabolic output with nuclear epigenetic control, thereby facilitating terminal megakaryocytic maturation.

Animals

Siglec-7 orchestrates mitochondrial dynamics and metabolic reprogramming to restrain human NK cell cytotoxic function.

Natural killer (NK) cells are innate lymphocytes that directly eliminate tumor and virus-infected cells by integrating signals from activating and inhibitory receptors, and their effector functions are tightly coupled to cellular metabolism. Given that the inhibitory receptor PD-1 reprograms T cell metabolism to shape functional fate, the bioenergetic consequences of inhibitory receptor engagement on human NK cells remain largely unexplored, particularly for sialic acid-binding immunoglobulin-like lectin (Siglec-7), a glyco-immune checkpoint receptor. Here, we investigated metabolic programs and effector functions associated with Siglec-7 expression and antibody-mediated Siglec-7 ligation in primary NK cells and NK-92MI cells. Siglec-7POS NK cells exhibited selectively impaired CD107a degranulation under glycolytic and oxidative phosphorylation inhibition, whereas Siglec-7NEG cells remained relatively resistant, indicating distinct energetic wiring between these subsets. Engagement of Siglec-7 by an agonistic antibody induced mitochondrial fission with altered Drp1 phosphorylation, transient mitochondrial depolarization, and broadly suppressed mitochondrial respiration, while concurrently enhancing glycolytic capacity, consistent with a dual metabolic shift upon Siglec-7 ligation. In contrast, sustained Siglec-7 expression in NK-92MI-S cells was associated with globally enhanced mitochondrial respiratory capacity, indicating that sustained Siglec-7 expression and short-term treatment with an agonistic anti-Siglec-7 antibody were associated with distinct metabolic profiles in NK cells. Furthermore, Siglec-7POS NK cells showed increased accumulation of autophagic vacuole, reduced proliferation, and heightened apoptotic susceptibility compared with Siglec-7NEG counterparts. Collectively, these findings support an association between Siglec-7 status, mitochondrial homeostasis, and metabolic fitness in NK cells, with Siglec-7NEG cells retaining a metabolically robust, cytotoxic phenotype.

Journal Article

Colchicine attenuates cardiac hypertrophy by targeting the macrophage-driven Interleukin-6 suppression.

Hypertrophic cardiomyopathy (HCM), the most prevalent inherited cardiovascular disease, is strongly linked to progressive heart failure and sudden cardiac death (SCD). However, its underlying pathogenic mechanisms remain incompletely understood, and effective therapeutic strategies are still lacking. Here, we established two murine HCM models harboring high SCD risk-associated mutations. Single-cell RNA sequencing revealed immune activation and enhanced fibrotic remodeling in the myocardium of these models. Therefore, we hypothesized that colchicine, a widely used anti-inflammatory drug known to reduce cardiovascular events in multiple cardiac disorders, may also represent a promising therapeutic candidate for HCM. As we expected, colchicine treatment attenuated pathological remodeling in our study, as evidenced by reduced cardiomyocyte hypertrophy, decreased fibrosis, and downregulation of cardiac stress markers (Anp, Bnp) and fibrotic mediators (Ctgf, Col1a1, Col3a1). In addition, colchicine attenuated pro-inflammatory macrophage populations and suppressed IL-6 expression, thereby contributing to the preservation of cardiac function. These findings provide the first preclinical evidence that colchicine alleviates myocardial inflammation and fibrosis in HCM, underscoring its potential as a novel therapeutic strategy to reduce fibrosis, lower SCD risk, and improve patient outcomes.

Animals

ALID score for treatment-effect heterogeneity of adjunctive low-voltage area ablation in persistent atrial fibrillation: A post hoc analysis of SUPPRESS-AF.

BACKGROUND: In persistent atrial fibrillation (AF), the incremental benefit of adjunctive low-voltage area (LVA) ablation beyond pulmonary vein isolation (PVI) remains inconsistent. OBJECTIVE: To examine whether a simple clinical score characterizes treatment-effect heterogeneity of adjunctive LVA ablation among patients with mapped LVA&#xa0;>&#xa0;5&#xa0;cm2 and to perform an exploratory supportive analysis in an independent randomized cohort. METHODS: In this post-hoc analysis of SUPPRESS-AF, which included patients with persistent AF and mapped LVA&#xa0;>&#xa0;5&#xa0;cm2 after PVI, four variables-age&#xa0;&#x2265;&#xa0;75&#xa0;years, left atrial diameter&#xa0;>&#xa0;44&#xa0;mm, estimated glomerular filtration rate&#xa0;<&#xa0;60&#xa0;mL/min/1.73&#xa0;m2, and absence of diabetes-were combined into the ALID score (0-4). Patients were stratified into low (0-1), intermediate (2), and high (3-4) score groups. Because EARNEST-PVI did not use LVA-guided ablation or select patients based on mapped LVA, it was analyzed as an exploratory supportive cohort rather than as an external validation cohort. RESULTS: In SUPPRESS-AF (n&#xa0;=&#xa0;336), a significant treatment-by-score interaction was observed (P&#xa0;<&#xa0;0.001). Adjunctive LVA ablation was associated with increased recurrence in the low-score stratum (HR 3.92; 95% CI 1.50-10.20) and reduced recurrence in the high-score stratum (HR 0.48; 95% CI 0.26-0.86). In EARNEST-PVI (n&#xa0;=&#xa0;494), a qualitatively similar interaction pattern was observed for additional ablation beyond PVI (interaction P&#xa0;=&#xa0;0.029), although the ablation strategy differed from LVA-guided ablation. CONCLUSIONS: Among patients with persistent AF and mapped LVA >5&#xa0;cm2, the ALID score identified heterogeneity in response to adjunctive LVA ablation. These hypothesis-generating findings require prospective validation before clinical implementation.

Humans

Tripled-Stranded Antisense Oligonucleotide for Biomarker-Activated Suppression of Essential Genes.

Conditional activation of antisense oligonucleotides (ASOs) is a promising strategy for selective suppression of cancer cells without affecting normal cells. In this study, we developed a tripled-stranded ASO (tsASO) that is rendered inactive through complexation with two additional oligonucleotides. The key innovation is the use of partial overlap between the parent ASO and the biomarker sequence, combined with toehold-mediated strand displacement, enabling precise conditional activation. The tsASO effectively triggered RNase H-mediated degradation of DYNC1I2 and DARS1 RNAs exclusively in the presence of the ERBB2 sequence. In cell-free systems, the tsASO demonstrated high cleavage efficiency (up to 81%), comparable to the parent ASO efficiency, with minimal background activity in the absence of the biomarker sequence, validating the concept at the molecular level. However, in cells using lipid-based transfection, the tsASO exhibited nonspecific cytotoxicity that did not correlate with biomarker presence or target gene expression. Detailed analysis showed no clear support for known sequence-driven toxicity mechanisms (CpG/TLR9, G-quadruplexes) in the nonimmune cell lines, suggesting that the primary limitation is intracellular delivery rather than the tsASO design. Future work should focus on optimizing delivery platforms to achieve controlled cellular uptake and biomarker-dependent release, unlocking the therapeutic potential of this conditional gene silencing approach.

Oligonucleotides, Antisense

MARK1 suppresses infectious bursal disease virus replication via phosphorylating VP3.

Infectious bursal disease virus (IBDV) of the Birnaviridae family is a non-envelope, double-stranded RNA virus that encodes a VP3 protein with multiple functions, which controls viral genome replication, IFN-&#x3b2; production, and virus traffic in infected cells. Posttranslational modifications (PTMs), such as ubiquitination, of VP3 have been demonstrated for affecting its function and stability. To clarify the mechanism by which VP3 is regulated in IBDV infected cells, we focused on the phosphorylation of VP3. Mass spectrometry analysis identified that microtubule-affinity regulating kinases 1 (MARK1) was a kinase interacting protein of VP3. Inhibitory function of MARK1 in affecting viral replication was validated. We describe the phosphorylation event at the serine 130 (S130) and serine 163 (S163) residues of VP3 mediated by MARK1 via mass spectrometry analysis. Alanine replacement of the phosphorylation sites in VP3 significantly enhanced its RNA-binding activity. Additionally, the mutation of two serine residues led to remarkably improved in its polymerase-enhancing function. We then incorporated the two mutations to rescue recombinant IBDV. Viral growth curve analysis revealed that replication of mutant IBDV was significantly enhanced relative to wild type (WT) virus. In conclusion, we found that VP3 functions are specifically regulated by MARK1 mediated phosphorylation at S130 and S163 and that this regulation suppresses IBDV replication ultimately.

Infectious bursal disease virus

Suppression of AAV-Delivered Transgene Expression Using Artificial MicroRNAs Delivered by an Alternative AAV Serotype.

Adeno-associated virus (AAV) gene transfer vectors mediate long-term expression in nondividing cells, an advantage for treating chronic disorders. However, current platforms lack a way to selectively shut down transgene expression if adverse effects arise. To create an "off switch," we hypothesized that incorporating unique artificial microRNA (amiRNA) target sequences into an AAV expression cassette would allow subsequent suppression of transgene expression using a second AAV vector encoding the cognate amiRNA. We introduced 22-nt sequences absent from human and mouse transcriptomes into the 3' untranslated region (UTR) of a therapeutic AAV cassette. To identify optimal amiRNAs, two tandem copies of each amiRNA were cloned into the 3'UTR of an mCherry reporter gene. In vitro assessment of six amiRNA/target pairs using a dual luciferase assay identified four amiRNAs that efficiently suppressed reporter expression. Cells cotransfected with target site 3 (TS3) and amiRNA-T3B showed the greatest reduction in luciferase activity (80%, p < 0.0001) and were selected for further study. The "off-switch" system was then evaluated using an AAV5 therapeutic vector expressing a recombinant humanized anti-IgE monoclonal antibody (AAV5-TBG-anti-IgE-TS3), designed for long-term suppression of allergen-induced reactions. Co-transfection of HEK293T cells with anti-IgE-TS3 and amiRNA-T3B significantly reduced anti-IgE mRNA and protein levels relative to a control amiRNA (p < 0.0001). In vivo testing in Balb/c mice (n = 5) involved intravenous administration of AAV5-anti-IgE-TS3 (3.2 &#xd7; 1010 gc), followed 4 weeks later by an AAVrh.10 amiRNA vector (AAVrh.10-TBG-amiRNA-T3B; 1 &#xd7; 1011 gc). Control mice receiving only the therapeutic vector expressed 18.4 &#xb1; 13.8 &#xb5;g/mL serum anti-IgE at 10 weeks. In contrast, mice receiving the amiRNA "off" vector showed marked suppression of anti-IgE (0.3 &#xb1; 0.15 &#xb5;g/mL, p < 0.0001). These findings provide proof-of-concept that AAV-delivered amiRNAs can selectively switch off transgene expression, offering a strategy to improve the safety of AAV-mediated gene therapies.

Dependovirus

Autodissemination stations suppress Aedes notoscriptus mosquitoes and reduce Buruli ulcer risk in urban Australia: a randomized controlled field trial.

Aedes notoscriptus are mosquito vectors implicated in transmission of Mycobacterium ulcerans. This bacterium causes a destructive infection of skin and soft tissue called Buruli ulcer. Here we ran a randomized controlled trial in an urban Buruli ulcer endemic area in Melbourne, Australia to test whether autodissemination mosquito control stations, containing pyriproxyfen (larvicide) and Beauveria bassiana (entomopathogenic fungus), suppress Ae. notoscriptus populations. Six geographic areas each received 100 autodissemination stations for 8&#x2009;weeks, and six control areas received no stations between 25 January 2024 and 21 March 2024. The primary outcome measure was mosquito population numbers. After the trial, there was a 70% average reduction in mosquito egg counts among the six intervention areas compared to control areas (P&#x2009;=&#x2009;0.0076). In an ad hoc analysis, we then explored human Buruli ulcer notifications in treatment and control areas. After accounting for the 4.8-month mean incubation period, there was an 83% reduction in infection likelihood coinciding with peak intervention effect (intervention zones 1 case, control zones 6 cases, incidence ratio rate 0.167, 95% CI 0.0026-1.054, P&#x2009;=&#x2009;0.047). The effect was not observed during the same time period in the year previous or following 2024, when no interventions were undertaken. A strong correlation (R2&#x2009;=&#x2009;0.85) was observed between decreased disease risk and mosquito suppression. These data show that autodissemination traps can effectively lower urban mosquito populations and reduce the threat of Buruli ulcer in humans.

Animals

Human iPSC-EV-loaded nanofiber stent coatings accelerate vascular repair by enhancing EGFR/HIF-1&#x3b1; signaling and suppressing ROCK1-mediated remodeling.

Arterial disease management is shifting from antiproliferative drug-eluting stents toward approaches that restore endothelial function and modulate smooth muscle cell (SMC) behavior. Stem cell-derived extracellular vesicles (EVs) carry miRNAs that promote endothelial proliferation and migration while restraining aberrant SMC growth and inflammation. Here, human induced pluripotent stem cell (iPSC)-derived EVs were collected by ultracentrifugation and incorporated into 50:50 poly (lactic-co-glycolic acid) (PLGA 503) core-shell nanofibrous membranes, which were fabricated as stent coatings for sustained release to overcome rapid clearance and poor tissue retention. EVs derived from three independent iPSC lines all enhanced tube formation in human umbilical vein endothelial cells (HUVECs) under hypoxic and serum-starved conditions and revealed a trend toward reduced platelet-derived growth factor-BB (PDGF-BB)-induced smooth muscle cell (SMC) migration. The fabricated core-shell nanofibers enabled sustained EV release, maintaining therapeutic efficacy for 28 days. Small RNA sequencing (NGS) analysis demonstrated that EVs from these independent iPSC lines shared miR-148a-3p and members of the miR-92 family, which collectively accounted for more than 75% of the reads within the 25 top-expressed miRNA set. In vitro, iPSC-EVs enhanced HUVEC proliferation and survival signaling by downregulating the negative regulators ERRFI1 and VHL, which are specific targets of miR-148a-3p and the miR-92 family, thereby activating the EGFR and HIF-1&#x3b1; axes and driving downstream ERK1/2 and VEGF expression under hypoxic and serum starvation stress conditions. Concurrently, iPSC-EVs prevented PDGF-BB-induced SMC phenotypic switching by downregulating ROCK1, a target of miR-148a-3p, thereby inhibiting downstream AKT and ERK signaling and preserving contractile markers while suppressing the synthetic phenotype. In vivo, the iPSC-EV-functionalized scaffolds significantly accelerated re-endothelialization and inhibited neointimal hyperplasia, evidenced by the upregulation of angiogenic factors (VEGF, CD31) and the concurrent suppression of pathological remodeling markers (&#x3b1;-SMA, MMPs) and inflammatory cytokines (IL-6, TGF-&#x3b2;1). Therefore, iPSC-EVs enriched with specific miRNAs and delivered via PLGA 503 core-shell nanofibers promote endothelial repair while suppressing SMC overgrowth, providing a promising strategy for vascular healing.

Core-shell nanofibers

Weight Loss without Food Intake Suppression through Size-Dependent Retention of Anti-Inflammatory Nanomedicines.

Obesity is a risk factor for high-mortality health conditions, including cardiovascular diseases and type 2 diabetes, which makes the advancement of efficacious and safe weight loss therapies a high priority in pharmacology. The causal link between obesity and its comorbid conditions is believed to be a chronic state of inflammation originating within adipose tissue, with macrophages playing central roles, an axis that is not targeted directly by current therapies. Here, we use nanocarriers to deliver an anti-inflammatory glucocorticoid receptor agonist to adipose tissue macrophages and report the impact of size on therapeutic effect. Three dextran nanocarriers between 4-30 nm in hydrodynamic diameter released molecular drug cargo at equivalent rates and exhibited similar biological potency in vitro. In vivo in a mouse model of obesity, body weight and body fat were reduced in a size-dependent manner after 2-4 weeks of treatment. Unlike current clinical pharmacotherapies for weight loss, these body composition changes were not associated with changes in food intake. Greater retention of larger dextran nanocarriers in visceral adipose tissue appears to elicit a local change to promote browning by increasing mitochondrial abundance and lipid droplet fragmentation. Further development of this platform may result in a safe and potent modulator of adipose tissue in the state of obesity without direct action on nutrient intake to address malnutrition and lean body mass deficiencies observed with current weight loss pharmacotherapies.

Animals