PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Base editing”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

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

At least 19 recordsLinked to original sources
PubMed2026

Base editing rescues a hereditary motor neuron disease in mouse and patient-derived iPSC organoid models.

In hereditary motor neuron diseases (MNDs), including forms of amyotrophic lateral sclerosis (ALS) caused by single-nucleotide variants, effective therapeutic strategies need to address both gain- and loss-of-function mechanisms. Genome editing-based gene therapy represents a promising approach for simultaneously targeting these mechanisms. To establish proof-of-concept for base editing in a hereditary MND, we targeted the P285L variant in the TRK-fused gene (TFG), which causes hereditary motor and sensory neuropathy with proximal dominant involvement (HMSN-P), a disorder that shares clinical and histopathological features with ALS. We identified the optimal adenine base editor by comparing candidate editors in HMSN-P patient-derived induced pluripotent stem cells (iPSCs). We then generated a transgenic mouse model expressing human TFG P285L and evaluated the selected editor by subpial delivery of adeno-associated virus (AAV) vectors to the spinal cord. AAV-mediated base editing prolonged survival, preserved motor neurons, and attenuated axon loss in ventral nerve roots. Treatment with the selected base editing vector reduced TFG aggregation and suppressed neuronal death in HMSN-P iPSC-derived neuromuscular organoids. Collectively, these findings support the therapeutic potential of base editing for hereditary MNDs.

AAV↗
PubMed2026

Base editing reversal of radiation sensitivity in NHEJ1 immunodeficiency.

Inherited defects of DNA double-stranded break (DSB) repair can result in radiosensitive/radiation-sensitive (RS) SCID (RS-SCID). We applied base editing to reverse NHEJ1 mutations in patient fibroblasts, exemplifying how this technology can help interrogate RS sequence variants.

Journal Article↗
PubMed2026

Advances in CRISPR Base Editing: From Molecular Evolution to Therapeutic Applications in Genomic Medicine.

CRISPR-Cas9 systems revolutionized gene editing, but inherent drawbacks, namely DNA double-strand breaks (DSBs) and the difficulty of achieving precise repairs (due to low HDR efficiency), led researchers to invent new, more accurate gene editing tools. Base editing represents a significant leap forward, enabling targeted single-nucleotide conversions directly on the DNA without DSBs or donor templates. The core technology involves fusing catalytically dead or nickase Cas proteins to DNA deaminase enzymes. Cytosine base editors (CBEs) convert C•G to T•A pairs, while adenine base editors (ABEs) change A•T to G•C. These editors exploit the deaminase function within the R-loop structure formed by Cas binding and co-opt endogenous DNA repair mechanisms for precision. While offering improved efficiency and editing precision, base editing faces persistent challenges, such as off-target effects, bystander edits, delivery and ethical concerns. Continuous engineering efforts have refined these tools, enhancing accuracy, expanding targetability and reducing unwanted edits. The base editing arsenal has also broadened to include C-to-G base editors (CGBEs), dual A&C editors and versions targeting organelles. Successful preclinical studies demonstrating the correction of mutations responsible for the disease have paved the way for clinical trials, which are now testing therapies for conditions like sickle cell disease, β-thalassaemia and hypercholesterolemia using various delivery systems. This review explores CRISPR base editing's origins, mechanisms of action, potential therapies and current restrictions, pointing to its broadening impact on medical genetics.

Humans↗
PubMed2026

Base editing for precision therapeutics.

Base editing (BE), the precise installation of single-nucleotide changes in DNA or RNA without inducing double-strand breaks, holds substantial therapeutic promise for correcting single-nucleotide variants, which constitute more than half of the known pathogenic genetic variants. Recent advances have improved base editor specificity, efficiency, and delivery, enabling clinically oriented procedures. Clinically, BE has shown early success or strong translational promise in sickle cell disease, β-thalassemia, leukemia (via CAR T and epitope engineering), hypercholesterolemia (PCSK9 and ANGPTL3), alpha-1-antitrypsin deficiency, and glycogen storage disease type Ia. Key remaining challenges include bystander editing within the activity window, residual off-target DNA and RNA editing, delivery constraints (payload size, tissue targeting, and redosing limits), immunogenicity, and the need for durable long-term safety evidence across relevant cell types and disease contexts. Continued technological refinements, careful preclinical validation, and rigorous clinical assessment will be essential to fully realize BE's transformative potential in precision medicine.

Humans↗
PubMed2026

Combinatorial base editing couples disease correction with lineage amplification in hematopoietic stem and progenitor cells.

First-generation genome editing therapies have largely focused on correcting or compensating for pathogenic variants. However, as these approaches enter the clinic, emerging biological constraints limit maximal therapeutic impact. Because globin genes are activated late during erythroid differentiation, genome-corrected hematopoietic stem and progenitor cells (HSPCs) gain little selective advantage in the bone marrow. Here, we establish a strategy that links therapeutic genome edits to an erythroid fitness-enhancing allele to amplify the output of clinically relevant cells. We develop a multiplex base editing strategy that couples fetal hemoglobin (HbF) reactivation with erythroid lineage expansion. Introduction of a naturally occurring erythropoietin receptor truncation (tEPOR) associated with benign erythrocytosis increased erythroid cell production without impairing viability or differentiation. Combinatorial editing of tEPOR together with the BCL11A erythroid enhancer and HBG1/2 promoters in healthy donor, sickle cell disease, and β-thalassemia HSPCs synergistically increased erythroid proliferation and HbF expression beyond single base-edited or Casgevy-treated controls. Multiplex base-edited HSPCs retained long-term lineage repopulation and engraftment capacity in vivo, establishing a modular strategy that pairs disease correction with lineage amplification to improve therapeutic potency.

Journal Article↗
PubMed2024

Introducing a hemoglobin G-Makassar variant in HSCs by in vivo base editing treats sickle cell disease in mice.

Precise repair of the pathogenic mutation in hematopoietic stem cells (HSCs) represents an ideal cure for patients with sickle cell disease (SCD). Here, we demonstrate correction of the SCD phenotype by converting the sickle mutation codon (GTG) into a benign G-Makassar variant (GCG) using in vivo base editing in HSCs. We show successful production of helper-dependent adenoviral vectors expressing an all-in-one base editor mapping to the sickle mutation site. In HSC-enriched cells from SCD patients, transduction with the base editing vector in vitro resulted in 35% GTG > GCG conversion and phenotypic improvements in the derived red blood cells. After ex vivo transduction of HSCs from an SCD mouse model and subsequent transplantation, we achieved an average of 88% editing at the target site in transplanted mice. Importantly, in vivo HSC base editing followed by selection generated 24.5% Makassar variant in long-term repopulating HSCs of SCD mice. The treated animals demonstrated correction of disease hallmarks without any noticeable side effects. Off-target analyses at top-scored genomic sites revealed no off-target editing. This in vivo approach requires a single non-integrating vector, only intravenous/subcutaneous injections, and minimal in vivo selection. This technically simple approach holds potential for scalable applications in resource-limiting regions where SCD is prevalent.

Animals↗
PubMed2026

Enhancing CRISPR-Cas12a base editing in plants with LbCas12a variants and introns.

Cytosine base editors (CBEs) and adenine base editors (ABEs) are powerful tools for precise genome editing in plants. Conventionally, such base editors are built upon the CRISPR-Cas9 systems where Cas9 nickases are used. To expand the base editing scope and minimize off-target effects, base editors derived from the CRISPR-Cas12a systems are desired. However, the use of deactivated Cas12a (dCas12a) in such base editors constrains the editing activity, preventing the wide use of Cas12a base editors for plant research and trait development. In this study, we demonstrate the use of an ABE based on the efficient LbCas12a-RRV variant to introduce herbicide-resistant mutations in OsACCase in rice. To improve Cas12a CBEs and ABEs, we inserted introns into the coding sequence of dLbCas12a-RRV. This intron-containing Cas12a-CBE shows substantial improvement in editing efficiency in rice, compared to the intron-less counterparts. By contrast, the improvement of ABE with the intron-containing dLbCas12a-RRV is very limited, partly due to the already high baseline editing efficiency of the intron-less dLbCas12a-RRV ABE. Testing of these base editors in poplar shows elevated C-to-T base editing by dLbCas12a-RRV-intron-CBE. For A-to-G editing, ABEs built upon dLbCas12a-RV and dLbCas12a-RRV variants showed significant improvement over ABEs derived from wild-type LbCas12a and the ttLbCas12a variant. The addition of introns to dLbCas12a-RRV does not further improve the base editing efficiency. With whole genome sequencing in rice, we evaluated genome editing specificities with these improved Cas12a base editors. Our analyses show that both intron-containing Cas12a CBE and ABE barely introduce guide RNA-dependent off-target mutations. However, they can generate guide RNA-independent off-target mutations, which are likely attributed to the high enzymatic activities of the deaminases. Collectively, our study demonstrates the successful use of a Cas12a base editor for trait development and reports improved Cas12a CBEs and ABEs for precise base editing in plants.

Oryza↗
PubMed2025

Installation of Dominant-Negative Mutations in FAS and TGFβR2 via Base Editing in Primary T Cells.

Adoptive cell transfer (ACT) of engineered T cells is effective against B-cell malignancies but has faltered against solid tumors due to the immunosuppressive tumor microenvironment (TME). FASL and TGFβ are key mediators of T cell dysfunction in the TME and overexpressing dominant negative (dn) forms of their receptors in T cells increases anti-tumor efficacy in solid tumor models. However, an approach which directly targets the endogenous genes would be more amenable to multiplex editing and reduce competition with WT alleles. Here, we employ base editing (BE) in primary human T cells to install naturally occurring dominant negative FAS and TGFβR2 mutations. In vitro survival and proliferation assays demonstrate that BE T cells are resistant to pro-apoptotic and anti-proliferative effects of FAS and TGFβ signaling. CAR-T cells with BE-installed dn TGFβR2 or dn FAS exhibit improvements in cytotoxicity, while dn TGFβR2 CAR T demonstrate increased persistence and reduced expression of phenotypic markers of exhaustion compared to controls. Moreover, BE-engineered dn CAR T outperform lentiviral-engineered cDNA over expression counterparts in several functional assays. Considering the efficiency of BE and its amenability for multiplex editing, our novel approach lends itself to engineering strategies necessary to overcome T cell dysfunction in solid tumors.

CAR T↗
PubMed2026

Synergistic HMGN1 and VP64 Fusions Potentiate High-Precision and PAM-Flexible Base Editing.

RNA-guided CRISPR-derived base editors (BEs) have revolutionized genome editing by enabling targeted base substitutions. However, their application is frequently constrained by the stringent requirement for PAM sequences and low editing precision (bystander editing). Here, we present a robust strategy to overcome these limitations by coupling SpRY, a near-PAM-less Cas9 variant, with truncated CDA1 cytidine deaminases. While this combination enables precise editing of virtually any cytosine in the genome, it initially exhibited suboptimal efficiency. To address this, we systematically screened a diverse panel of candidate DNA-binding proteins and identified that the synergistic fusion of HMGN1 and VP64 substantially enhances editing activity without compromising precision. Importantly, this enhanced editing efficiency was achieved without markedly increasing off-target effects. Our new BEs demonstrated robust performance not only in yeast but also in rice, suggesting broad applicability in gene therapy, precision breeding, and fundamental research.

Gene Editing↗
PubMed2025

Engraftment and persistence of HBB base-edited hematopoietic stem cells in nonhuman primates.

Sickle cell disease (SCD) is caused by a single nucleotide change in the β-globin gene that adenine base editors can convert to the nonpathogenic Makassar β-globin variant. Here, we evaluated the long-term efficiency and off-target editing potential of autologous Makassar base editing in three rhesus macaques as a step toward human translation. Base editing of CD34+CD90+ hematopoietic stem cells (HSCs) at the Makassar locus reached greater than 60% efficiency using a bystander nucleotide as a proxy for the sickle cell target in cells from healthy macaques. No impact on myeloid and erythroid colony formation was seen, and clonal analysis revealed that >90% of HSCs were edited, >20% with biallelic editing. After transplantation of autologous gene-edited HSCs, all three macaques rapidly recovered neutrophils, red blood cells, and platelets with stable editing of 25.6%, on average, observed across nucleated blood cells. Similarly, the bone marrow stem cell compartment maintained over 20% of cells harboring mono- or biallelic edits. Off-target editing was assessed at over 900 candidate sites, with editing observed at eight sites, but no selection for or impact of these edits was observed throughout engraftment. These data support further translation of base editing of autologous HSCs for the treatment of patients with SCD.

Animals↗
PubMed2026

Base editing reveals an essential role for NANOG in human embryogenesis.

Understanding how the first cell lineages in human development are specified and maintained has fundamental importance and clinical implications for regenerative medicine, infertility and pregnancy loss. Although mouse models have provided valuable insights into transcription factors regulating early development, translating these findings to human embryos has been limited by ethical, technical and biological constraints. Functional studies of transcription factors in human embryos have been hindered by nuclease-based genome editing approaches that induce genotoxicity1-3. Here, to overcome this, we applied ABE8e adenine base editing4,5 to precisely target an exon splice donor site, resulting in a splicing defect and functional knockout of the developmental regulator NANOG in human embryos. This approach did not trigger genotoxicity and showed limited off-target editing. Loss of NANOG disrupts pluripotent epiblast specification and instead cells differentiate towards a primitive endoderm (yolk sac) or trophectoderm (placental) transcriptional programme. Retention of primitive endoderm differentiation in NANOG-edited human embryos reveals a functional compensation that is distinct from mouse, underscoring the importance of directly investigating human development. Our findings demonstrate an essential role for NANOG in human pluripotency and epiblast specification and highlight the utility of base editing for functional interrogation of human development.

Journal Article↗
PubMed2026

Highly efficient base editing at PCSK9 and normal human embryo development.

Cas9-based tools enable programmable DNA lesions for studying repair outcomes, gene function, and genome correction. In human embryos, Cas9-induced DNA double-strand breaks are genotoxic, causing frequent aneuploidy and large deletions1,2. Here, we evaluate DNA repair outcomes at nicks and mismatches introduced by base editors at the PCSK9 and HBG loci in human embryos. Delivering ABE8e-V106W as a protein at fertilization achieved editing at all PCSK9 alleles, supporting development to the blastocyst stage and the derivation of homozygous edited stem cell lines. No insertions or deletions were detected, although rare on-target chromosome breakage and chromosomal abnormalities occurred. Nevertheless, editing at bystander and off-target sites was mosaic, and the introduction of the editor as mRNA caused frequent embryo arrest due to guide-independent deaminase activity. Thus, unlike Cas9-induced DNA breaks, base editor-induced lesions are efficiently repaired. However, undesirable consequences for the genome and development can occur, currently precluding clinical use in reproduction.

Journal Article↗
PubMed2025

Genetic Engineering and Screening Using Base Editing and Inducible Gene Knockout.

Genetic engineering and screening in human cells are powerful techniques for the precise and comprehensive identification and analysis of gene and protein domain functions. Genome-wide knockout screens have been extensively utilized to discover essential genes, tumor suppressors, and genes that regulate responses to various chemicals, including antimitotic and therapeutic drugs. The advent of base editors, which facilitate the targeted mutation of single amino acids, has advanced the identification of critical and functional domains or motifs. In this context, we outline methods for creating efficient base editor and inducible knockout cell lines for targeted gene manipulation and conducting genetic screens to elucidate the roles of genes and their domains within a specific cell biological context.

Humans↗
PubMed2026

Lipid-nanoparticle-mediated base editing of the trabecular meshwork rescues glaucoma in vivo.

Mutations in MYOC, the most common genetic cause of glaucoma, cause misfolded myocilin to accumulate in the endoplasmic reticulum (ER), leading to trabecular meshwork (TM) dysfunction, elevated intraocular pressure, and progressive vision loss. While gene editing offers curative potential, current delivery methods rely on viral vectors, which are limited by inflammation, off-target effects, and poor translatability. Here, we report a nonviral lipid nanoparticle (LNP) platform that enables selective in vivo delivery of mRNA encoding an adenine base editor and single guide RNA (LNP-ABE) to TM cells. A direct comparison of LNP-mCherry with lentiviral GFP revealed that LNPs outperform viral vectors, achieving markedly higher efficiency and greater selectivity for the TM without inducing ocular inflammation. In a Cre-inducible Tg.CreMYOCY437H glaucoma mouse model, LNP-Cre mRNA selectively induced mutant MYOC expression in the TM, faithfully recapitulating key disease features. A single administration of LNP-ABE achieved efficient on-target editing of mutant MYOC, reducing mutant myocilin protein by approximately 46%, decreasing aggregates, alleviating ER stress, and fully rescuing the glaucomatous phenotype in Tg.CreMYOCY437H mice. Importantly, no off-target editing or ocular toxicity was detected. These findings establish LNP-based mRNA delivery as a safe, efficient, and clinically translatable approach for TM-targeted genome editing with broad therapeutic potential in glaucoma.

Animals↗
PubMed2026

In Vivo Base Editing Partially Rescues Bone Dysplasia in a Mouse Model of Hutchinson-Gilford Progeria Syndrome.

Hutchinson-Gilford progeria syndrome (HGPS) is a premature aging disorder affecting tissues of mesenchymal origin. Most patients harbor a c.1824C>T/p.G608= variant, commonly described as G608G, in exon 11 of LMNA that leads to aberrant splicing and production of the toxic progerin protein. In addition to cardiovascular, dermal, and adipose tissue deterioration, HGPS mouse models also develop progressive bone dysplasia that occurs in patients. Here we characterize the efficacy of in&#xa0;vivo mutation correction with an adenine base editor (ABE) to rescue structural and functional defects in HGPS transgenic murine bone tissue. Treatment of double-copy transgenic osteoblast cultures with a lentiviral-delivered CRISPR-Cas9 ABE achieved nearly 40% gene correction in&#xa0;vitro, resulting in significant reduction of progerin transcripts and protein, in the absence of selective agents. Furthermore, gene correction improved progeroid osteoblasts' capacity to deposit and mineralize extracellular matrix compared to untreated cultures. In&#xa0;vivo, a single intravenous dose of AAV9-delivered ABE corrected the mutation, achieving ~14%, ~22%, ~10% and <&#x2009;1% correction in bone by six months of age when administered at P3, P14, 1 and 4&#x2009;months of age, respectively. Partially rescued bone structural and physical parameters were observed in P14-treated mice with concomitant normalization of gene transcriptional programs and intracellular signaling pathways involved in bone remodeling. This work demonstrates in&#xa0;vivo delivery of a locus-specific DNA base editor to bone tissue, delineates the timing of treatment required for maximum efficacy, and suggests that this system might be tailored for application to other monogenic bone disorders.

Animals↗
PubMed2025

A streamlined base editor engineering strategy to reduce bystander editing.

Base editing (BE) can permanently correct over half of known human pathogenic genetic variants without requiring a repair template, thus serving as a promising therapeutic tool to treat a broad spectrum of genetic diseases. However, the broad activity windows of current base editors pose a major challenge to their therapeutic application. Here, we show that integrating a naturally occurring oligonucleotide binding module into the deaminase active center of TadA-8e, a highly active deoxyadenosine deaminase, enhances its editing specificity. When conjugated with a Cas9 nickase or alternative PAM Cas9 variants, the engineered TadA variant-TadA-NW1-consistently achieves robust A-to-G editing efficiencies within an editing window consisting of four nucleotides, substantially narrower than the 10-bp editing window of the TadA-8e-derived ABEs. Moreover, compared to ABE8e, ABE-NW1 shows significantly decreased Cas9-dependent and -independent off-target activity while maintaining similar on-target editing efficiency. Further, TadA-NW1 can be reprogrammed to perform desired cytidine deamination and adenine transversion within a restricted editing window. Finally, in a cystic fibrosis (CF) cell model, ABE-NW1 outperforms existing ABEs in accurately and efficiently correcting the CFTR W1282X variant, one of the most common CF-causing mutations. In all, we engineered a suite of base editors with refined activity windows, enabling more precise base editing. Importantly, this study presents a streamlined genome editor re-engineering strategy to accelerate the development of therapeutic base editing.

Gene Editing↗
PubMed2025

Engineering and comparison of cas12a-based genome editing systems in plants.

While Cas9 and Cas12a are both RNA-guided endonucleases used for genome editing, only Cas12a is able to process pre-crRNA via its additional ribonuclease activity. This feature reduces the complexity of Cas12a versus Cas9-based genome editing systems thus providing an attractive alternative for generating site-specific mutations in plants. Here we aimed to improve the efficiency of the cas12a-based generation of two double-strand breaks flanking the open reading frame of a target gene, leading to its full deletion. To this end, we compared the relative impact of different components on cas12a-based gene deletion efficiency in three different eudicotyledons, Arabidopsis thaliana, Lotus japonicus, and Nicotiana benthamiana. We detected the highest cas12a-based editing efficiency with a combination of suitable promoters for crRNA and cas12a expression, a tandem terminator to control cas12a expression, a re-coded cas12a, adapted to the codon usage of Arabidopsis and engineered to carry introns, and encoding a Cas12a flanked by a nuclear localization signal at both ends. Our work revealed the high potential for improving cas12a-based genome editing systems for plant genetic research.

Gene Editing↗